Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/25/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
956 PM MST TUE DEC 22 2015
.SYNOPSIS...
PACIFIC MOISTURE WILL SPREAD ACROSS THE REGION THROUGH THE WEEK
RESULTING IN PERIODS OF CLOUDINESS AND CHANCES FOR
PRECIPITATION...MAINLY NORTH AND EAST OF PHOENIX. THE BEST CHANCES
FOR RAIN APPEAR TO BE TONIGHT INTO WEDNESDAY AND AGAIN THURSDAY INTO
CHRISTMAS. WHILE THESE SYSTEMS DO NOT LOOK VERY WET...THEY COULD MAKE
FOR DIFFICULT TRAVEL CONDITIONS ACROSS NORTHERN ARIZONA. TEMPERATURES
WILL REMAIN NEAR NORMAL BUT ARE EXPECTED TO DROP LATE IN THE WEEK AND
INTO THE WEEKEND AS A STRONG AND COLD LOW PRESSURE SYSTEM AFFECTS THE
DESERT SOUTHWEST. SOME GUSTY DAYTIME WINDS AND SUB FREEZING NIGHTTIME
TEMPERATURES WILL BE POSSIBLE OVER THE WEEKEND FOR THE LOWER DESERTS.
&&
.DISCUSSION...
LOW STRATUS HAS BEEN QUITE PERSISTENT OVER SOUTH-CENTRAL ARIZONA
TODAY THROUGH THIS EVENING. PRECIP THIS AFTERNOON AND EVENING HAS
BEEN VERY MODEST...LIMITED TO SOME DRIZZLE AND SPOTTY LIGHT
SHOWERS...MOSTLY EAST OF THE METRO. SATELLITE IMAGERY INDICATES LOWER
CLOUDINESS HAS DECREASED OVER SOUTHWEST ARIZONA...NAMELY LA PAZ
COUNTY. THIS FITS THE MODEL PROJECTIONS. FOR SOUTH-CENTRAL ARIZONA
HOWEVER...MODELS ALSO SHOW LOW CLOUDS LINGERING THROUGH AT LEAST
WEDNESDAY MORNING IF NOT INTO THURSDAY. IN FACT...THEY INDICATE
CEILINGS WILL GET EVEN LOWER TONIGHT AND WEDNESDAY MORNING. OF
NOTE...THE RAP HAS BEEN INDICATING A BREAKUP OF THE OVERCAST STARTING
AS EARLY AS 08-09Z BUT STILL KEEPING AT LEAST SCATTERED LOW CLOUDS.
THE NAM AND GFS CONTINUE TO BE MORE PESSIMISTIC. WE WILL PROBABLY
SEE SOME SPOTS WITH HAZE/MIST BUT WITHOUT MORE RAPID CLEARING AND
WITHOUT PRECIP ON THE GROUND...IT WILL BE HARD TO GET DENSE FOG ON
THE LOWER DESERTS. FORECAST SOUNDINGS ALSO SUPPORT THIS. NOT SO FOR
HIGHER TERRAIN THOUGH. MAY NEED TO INSERT MENTION OF FOG FOR OUR
HIGHER TERRAIN FORECAST ZONE TONIGHT. AS THE MOISTURE LAYER GETS EVEN
MORE SHALLOW OVERNIGHT...SHOWERS/DRIZZLE WILL LIKELY TAPER OFF AFTER
09Z OR SO. THERE ARE SOME INDICATIONS OF AN INCREASE IN MOISTURE
DEPTH DURING THE DAY WEDNESDAY ALONG WITH SOME LIFT SO WILL HOLD ON
TO POPS.
&&
.PREVIOUS DISCUSSION...ISSUED 253 PM MST/153 PM PST...
LATEST VISIBLE SATELLITE SHOWS WIDESPREAD THICK STRATOCU AND
NUMEROUS AREAS OF MOUNTAIN WAVE CLOUDINESS ACROSS AZ. LATEST RADAR
CONTINUES TO SHOW BACKBUILDING LIGHT RAIN AND SPRINKLES ACROSS
NORTHERN MARICOPA COUNTY...INCLUDING PORTIONS OF THE PHOENIX AREA.
DESPITE THE PRESENCE OF A 100+ KT 250 MB JET...VORTICITY AND JET-
FORCED ASCENT REMAIN RELATIVELY WEAK. LIGHT PRECIPITATION APPEARS TO
BE MORE A RESULT OF THE SUFFICIENT MOISTURE TRANSPORT FROM THE
REMNANT ATMOSPHERIC RIVER COUPLED WITH ANOMALOUSLY STRONG MID-LEVEL
FLOW AND SUBSEQUENT OROGRAPHIC INFLUENCES. 500 MB WIND SPEEDS ARE NOT
EXACTLY OFF THE CHART...BUT CLOSE TO THE 90TH PERCENTILE PER THE SPC
SOUNDING CLIMATOLOGY AND NAEFS PERCENTILES.
THE THICK CLOUDINESS HAS INHIBITED INSOLATION AND TEMPERATURES HAVE
STRUGGLED TO GET THROUGH THE LOWER-MID 50S...STILL WELL ABOVE THE
RECORD LOW MAXIMUM OF 46 DEGREES IN PHOENIX. HI-RES WRFS ALONG WITH
THE NCAR ENSEMBLE AND LATEST RUNS OF THE HRRR INDICATE THAT THE
LIGHT PRECIP WILL GRADUALLY WORK EASTWARD INTO GILA COUNTY TONIGHT AND
EVENTUALLY SOUTHWARD TOWARDS PINAL COUNTY. ANY RAIN THAT DEVELOPS
WILL LIKELY ONLY AMOUNT TO A FEW HUNDREDTHS OF AN INCH AT MOST IN THE
LOWER DESERTS.
LATEST GFS AND ECMWF REMAIN IN GOOD AGREEMENT THE NEXT FEW
DAYS...INDICATING THAT THE MOIST NORTHWESTERLY FLOW WILL PERSIST.
TREND HAS BEEN A LITTLE BIT FURTHER TO THE EAST ACROSS THE HIGHER
TERRAIN OF MARICOPA AND GILA COUNTIES WITH REGARD TO THE BEST CHANCE
OF PRECIP. CONSEQUENTLY...FORECAST POPS HAVE BEEN REFINED TO DECREASE
VALUES FURTHER WEST AND INCREASE THEM ACROSS GILA COUNTY...IN LINE
WITH THE VALUES FROM THE LATEST GEFS REFORECAST CALIBRATED TO CLIMO.
LATEST MULTI-MODEL ENSEMBLE MEDIAN ALSO SUGGESTS THAT STORM TOTALS
ACROSS THE HIGHER TERRAIN OF GILA COUNTY COULD REACH A HALF OF AN
INCH THROUGH CHRISTMAS EVE. NO SIGNIFICANT CHANGES WERE MADE TO THE
TEMPERATURES...WHICH REMAIN AT OR BELOW NORMAL.
&&
.PREVIOUS DISCUSSION...
THE NEXT BETTER ORGANIZED SYSTEM WILL DEVELOP OUT OF THE GULF OF
ALASKA AND ARRIVE INTO OUR AREA LATE THURSDAY AND INTO FRIDAY. THIS
PARTICULAR SYSTEM WILL QUICKLY MOVE INTO THE AREA AND CUT-OFF FROM
THE MAIN STORM TRACK WHILE BRINGING A SIGNIFICANT COLD POOL AND
FORCING INTO THE REGION. TIGHT INTERSECTION OF FRONTOGENETICAL
FORCING AND MOISTURE BEFORE DRIER AIR BEGINS TO WRAP INTO THE AREA
FROM THE NORTH LIMITS PRECIPITATION AGAIN MAINLY ACROSS
NORTHERN/EASTERN AZ...EVEN LIMITING PRECIP CHANCES FOR THE PHX AREA
COME FRIDAY AND INTO SATURDAY. WITH THE SYSTEM LOOKING TO BE VERY
COLD...500 MB TEMPS AT -31C/700 MB TEMPS AT -14C AND 850 TEMPS AT -
2.5C ALL POSSIBLE UNDER THE STRONGER SCENARIOS...SNOW LEVELS WILL
DROP TO 3000 FEET OR POSSIBLY LOWER. THUS THE BIGGEST IMPACT WILL
LIKELY BE FOR TRAVELERS INTO OR ACROSS THE HIGHER ELEVATIONS AREAS OF
AZ. STRONG FUNNELING WINDS ALONG THE EASTERN FRINGE OF THE
SUBTROPICAL PACIFIC RIDGE AND THE DEPARTING CUT-OFF LOW WILL LEAD TO
WINDY CONDITIONS ALONG THE CO RIVER VALLEY FOR SATURDAY. LINGERING
INTO SUNDAY STRONG GUSTY WINDS FROM THE NORTH MAY CAUSE DIFFICULT
TRAVEL PERIODS FOR MOTORISTS ALONG EAST-WEST ORIENTED
ROADWAYS...INCLUDING INTERSTATE 8/10.
CLEARING SKIES...STRONG SURFACE HIGHS AND REINTRODUCTION OF THE
SIGNIFICANTLY COLDER AIRMASS WILL LEAD VERY COOL WEEKEND DAYTIME
TEMPERATURES AS WELL AS ANOTHER ROUND OF FREEZING OR SUB-FREEZING
TEMPERATURES FOR SOME OUTLYING LOWER ELEVATION DESERTS SATURDAY AND
SUNDAY MORNINGS. FOR THE EARLY NEXT WEEK...SOME DISCREPANCY REMAINS
BETWEEN THE DETERMINISTIC AND ENSEMBLE SUITES WITH THE TIMING OF
SHORTWAVE RIDGING AND ADDITIONAL LOW PRESSURE FEATURES PASSING
THROUGH THE REGION. AT THE MOMENT THOUGH WITH THE RE-ESTABLISHED DRY
AIRMASS AND LOSS OF ENHANCED MOISTURE FLOW FROM OFF THE NORTHEASTERN
PACIFIC THESE LOW PRESSURE WAVES APPEAR TO LACK MUCH BY WAY OF
PRECIP FOR THE FORECAST AREA AHEAD OF THE NEW YEAR`S HOLIDAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
RATHER MOIST LOWER TROPOSPHERE FOR CIGS THIS EVENING AT
5-7 KFT MSL WITH ISOLATED-SCT SHOWERS/DRIZZLE. HIGHER MOUNTAINS
OBSCURED. THOUGH SHOWERS EXPECTED TO DISSIPATE AFT 06Z CIGS WILL
LOWER FURTHER TO 3-5 KFT MSL BY 10-12Z WITH AREAS OF HAZE/MIST
REDUCING VSBYS BELOW 6SM...LOCALLY 4SM. LOWER MOUNTAIN TOPS OBSCURED.
CONDITIONS EXPECTED TO IMPROVE SIGNIFICANTLY AFTER 17-19Z. OF
NOTE...SOME MODEL GUIDANCE DEPICTS CEILINGS GOING SCATTERED AFT 09Z
BUT MAJORITY DOES NOT. SURFACE WINDS REMAIN LIGHT FAVORING EAST BUT
ABOVE THE SURFACE...WESTERLY WINDS PREVAIL.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SURFACE WINDS WILL FAVOR WESTERLY DIRECTIONS WEST OF THE LOWER
COLORADO RIVER VALLEY AND SOUTHERLY DIRECTIONS NEAR AND EAST OF THE
VALLEY. SPEEDS WILL BE STRONGER WEST OF THE LOWER COLORADO RIVER
VALLEY BUT WILL GENERALLY DECREASE TO NEAR 10 KTS. STRONG WESTERLY
FLOW WILL CONTINUE ABOVE THE SURFACE...FLIRTING WITH LLWS CRITERIA
UNTIL ABOUT 17-18Z. AS FOR CLOUDS...CIRRUS WILL CONTINUE TO DECLINE
AS WILL LOWER CLOUDS EAST OF THE RIVER VALLEY. WIND SPEEDS PICK UP
AGAIN WEDNESDAY AFTERNOON BUT NOT AS STRONG AS TUESDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A LOW PRESSURE SYSTEM WILL AFFECT THE DISTRICTS INTO THE WEEKEND...
BRINGING WIDELY SCATTERED DESERT RAIN AND MOUNTAIN SNOW SHOWERS FROM
MARICOPA COUNTY EASTWARD...WITH SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA DESERTS REMAINING DRY. AS THE LOW MOVES THROUGH THE
REGION...WINDS WILL INCREASE OUT OF THE NORTH-NORTHWEST WITH GUSTS
UP TO 40 MPH POSSIBLE ACROSS SOUTHEAST CALIFORNIA AND ALONG THE
LOWER COLORADO RIVER VALLEY SATURDAY. MUCH LESS WIND ALONG WITH
DRIER CONDITIONS ARE EXPECTED AREA-WIDE SUNDAY AS THE UPPER LOW
SHIFTS OFF TOWARDS THE EAST. MUCH DRIER AIR WILL SPREAD INTO THE
AREA BEHIND THE DEPARTING LOW...WITH MINIMUM HUMIDITY VALUES
DROPPING BACK INTO THE TEENS OVER MUCH OF SOUTHEAST CALIFORNIA AND
THE SOUTHWEST ARIZONA DESERTS INTO EARLY NEXT WEEK.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...AJ
PREVIOUS DISCUSSION...HIRSCH/NOLTE
AVIATION...AJ
FIRE WEATHER...CB/MEYERS
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1259 AM MST WED DEC 23 2015
.UPDATE...
ISSUED AT 1249 AM MST WED DEC 23 2015
WITH CLEARING SKIES BEHIND TONIGHTS SNOW BAND THAT CONTINEUS TO
MARCH EAST ACROSS THE PLAINS...AREAS OF THICK FOG ARE FORMING.
HAVE ADDED THESE AREAS OF THICKER FOG TO THE FORECAST...THOUGH
HIRES MODELS WANT TO KEEP IT MAINLY NORTH OF THE DENVER METRO
AREA. HIRES MODELS ALSO PERSISTENT IN BRINGING ANOTHER BATCH OF
SNOW SHOWERS TO THE METRO AREAS AFTER 4AM...ORIGINATING FROM THE
CURRENTBATCH OF SHOWERS ACROSS NORTHWESTERN COLORADO. ADDED A
SLIGHT CHANCE FOR THE METRO AREAS THEN PUSHING EAST FROM 4AM UNTIL
7AM. NOT EXPECTING MUCH ACCUMULATION AS THE BEST DYNAMICS HAVE
PUSHED EAST.
HAVE ALSO REMOVED CHANCES FOR SHOWERS FOR MOST OF WEDNESDAY AFTERNOON
FOR THE PLAINS. EVEN THOUGH THE AIRMASS SHOULD BE
UNSTABLE...DOWNSLOPING LOOKS TO OVERRIDE THIS. COULD STILL SEE A
CHANCE TO SEE SHOWERS MAINLY IN THE EVENING HOWEVER.
UPDATE ISSUED AT 1010 PM MST TUE DEC 22 2015
RAPID ZONAL FLOW ALOFT EQUATES TO RAPID CHANGES IN OUR WEATHER
CONDITIONS THIS EVENING. BANDED SNOWFALL HANGING OVER NORTHERN
PORTIONS OF THE CWA ALL EVENING HAS MADE LITTLE SOUTHWARD PROGRESS
AS MESOSCALE MODELS INDICATED. ALTHOUGH IN THE PAST HOUR THE TAIL
END OF THIS SNOW BAND OVERT THE FRONT RANGE HAS SHOWN SIGNS OF
ADVANCING SOUTHWARD IN RESPONSE TO THE NEXT INFLUX OF PACIFIC
MOISTURE SPREADING INTO THE NORTH CENTRAL MTNS AT THIS HOUR.
SNOWFALL RATES UNDER THE SNOW BAND NORTH OF DENVER IN THE 0.5 TO 1
INCH PER HOUR RATE. SHOULD SEE SIMILAR SNOWFALL RATES DEVELOPING
THE HIGH COUNTRY OVER THE NEXT HOUR OR TWO...WITH POSSIBLY GREATER
RATES OVER THE HIGH TERRAIN IN SUMMIT AND WESTERN PARK COUNTIES.
HRRR AND RAP INDICATE THE HIGHEST 6-HR SNOW TOTALS ON THE PLAINS
ACROSS MORGAN...WASHINGTON AND LOGAN COUNTIES WHERE 1-3 INCH
AMOUNTS ARE POSSIBLE. CLOSER TO THE FRONT RANGE COULD ANOTHER
INCH OR TWO FROM DENVER NORTHWARD AND PERHAPS AND INCH OR SO IN
THE DENVER AREA BEFORE 10Z TONIGHT...THAT`S ASSUMING A SNOW BAND
FORMS FARTHER SOUTH AS THE HRRR AND RAP INDICATE. SHOULD SEE LIGHT
TO MODERATE SNOWFALL REST OF TONIGHT IN THE HIGH COUNTRY WHERE WE
COULD SEE ANOTHER 3-5 INCHES ON WEST FACING SLOPES BY MORNING.
UPDATED FORECAST WITH THESE CHANGES ALREADY OUT.
UPDATE ISSUED AT 748 PM MST TUE DEC 22 2015
SNOW OVER LARIMER AND WELD COUNTIES WILL TO SPREAD SOUTH AND EAST
THROUGH THE EVENING AND OVERNIGHT HOURS. THE 00Z SOUNDING SHOWED A
NEARLY DRY ADIABATIC LAPSE RATE FROM 750MB UP TO 300 MB...SO
HEAVY CONVECTIVE SNOW WILL REMAIN POSSIBLE WITH BRIEF SNOWFALL
RATES OF 1 TO 2 INCHES PER HOUR POSSIBLE. AN ESTIMATED HALF INCH
HAS FALLEN IN FORT COLLINS SO FAR BASED ON WEB CAMERAS. INCREASED
POPS AND SNOWFALL AMOUNTS EARLIER AND THEY STILL APPEAR ON TRACK.
UPDATE ISSUED AT 518 PM MST TUE DEC 22 2015
LATEST SHORT RANGE MODELS AND 18Z MODELS SHOWING MORE SNOW FOR
NORTHEAST COLORADO TONIGHT. FAVORABLE SIDE OF THE JET WILL BE OVER
THE AREA. IN ADDITION...AIRMASS WILL BE UNSTABLE WITH LAPSE RATES
OF 6 TO 8.5 C/KM. LATEST RADAR SHOWING INCREASING RETURNS...MOST
OF WHICH IS VIRGA OVER LARIMER AND WELD COUNTIES. AIRMASS WILL
CONTINUE TO MOISTEN AND EXPECT SNOW TO INCREASE THROUGH THE
EVENING HOURS. UPDATED TO INCREASE POPS INTO THE LIKELY RANGE.
MOST AREAS WILL SEE LIGHT SNOWFALL...AN INCH OR LESS. HOWEVER A
FEW SNOW BANDS WILL BE POSSIBLE WHERE UP TO 3 INCHES MAY FALL.
TEMPERATURES WILL BE IN THE UPPER 20S TO LOWER 30S. SO ROADS WILL
BE SLOW TO ICE UP EXCEPT UNDER THE HEAVIER SNOW BANDS. THIS
SYSTEM WILL BE QUICK MOVING AND BE OUT OF THE AREA BY SUNRISE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 142 PM MST TUE DEC 22 2015
A BROAD UPPER LEVEL TROUGH CONTINUES TO BRING INCREASED MOISTURE
AND STRONG WNW WINDS INTO THE MOUNTAINS. SNOW SHOWERS AND GUSTY
WINDS WILL CONTINUE OVER THE MOUNTAINS THROUGH THE EVENING HOURS
BEFORE DIMINISHING OVERNIGHT. TOTAL ACCUMULATIONS WILL BE 8 TO 18
INCHES WITH THE HIGHER AMOUNTS OVER THE NORTHERN MOUNTAINS ON WEST
FACING SLOPES. AREAS NEAR THE PARK AND GORE RANGES IN THE NE
PORTIONS OF THE CWA COULD SEE UP TO 2 FEET ON WEST FACING SLOPES
THROUGH TOMORROW AFTERNOON. ON THE PLAINS THE SURFACE LOW THAT HAS
BEEN KEEPING SNOW OUT OF THE PICTURE WILL MOVE OFF TO THE SOUTH
AND EAST TONIGHT BRINGING SOME LIGHT FLURRIES TO THE NORTHERN
PLAINS. AREAS CLOSEST TO THE WYOMING BORDER WILL SEE A LITTLE
HIGHER AMOUNTS DUE TO SOME ENHANCED LIFT...HOWEVER AMOUNTS WILL BE
LIGHT WITH ACCUMULATIONS STAYING UNDER HALF AN INCH. TEMPERATURES
OVERNIGHT WILL BE COOL DUE TO THE COLD FRONT MOVING DOWN THIS
EVENING. LOWS FOR THE PLAINS WILL BE IN THE 20S AND SINGLE DIGITS
FOR THE MOUNTAINS.
FOR WEDNESDAY...THERE WILL BE A SLIGHT LULL IN THE SNOW INTENSITY
EARLY WEDNESDAY MORNING PRIOR TO THE NEXT UPPER LEVEL DISTURBANCE.
MODELS STILL SHOWING NEXT SHORTWAVE MOVING DOWN INTO COLORADO BY
THE AFTERNOON. THE JET WILL BE JUST TO THE SOUTH OF THE CWA BUT
LAPSE RATES ARE IMPRESSIVE AT 8-9 C/KM SO PERIODS OF CONVECTIVE
SNOW IS POSSIBLE WITH 1 INCH PER HOUR RATES DURING THE AFTERNOON
AT HIGHER ELEVATIONS. WITH THE NEXT WAVE UPPER LEVEL FLOW WILL
MOVE NW WHICH IS FAVORABLE FOR WEST FACING SLOPES. HIGHER SNOWFALL
AMOUNTS WILL BE POSSIBLE IN THESE AREAS. WILL KEEP THE WINTER
STORM WARNING FOR THE MOUNTAINS GOING UNTIL 6 PM DUE TO THE
CONVECTIVE NATURE AND THREAT OF BLOWING SNOW WITH THIS STORM.
FOR THE PLAINS THE FRONT WILL BRING A SLIGHT CHANCE OF SNOW BY THE
AFTERNOON AND EVENING WITH LIGHT ACCUMULATION EXPECTED. GFS IS
HINTING AT SOME QG MOVING OVER THE PLAINS IN THE AFTERNOON THAT
COULD BRING A SHORT PERIOD OF MORE INTENSE SNOWFALL THAT COULD
DROP A QUICK HALF INCH. SNOW WILL DECREASE IN THE EVENING WITH
SUBSIDENCE BEHIND THE FRONT. TEMPERATURES FOR WEDNESDAY WILL BE
SLIGHTLY COOLER IN THE UPPER 30S AND TEENS IN THE MOUNTAINS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 142 PM MST TUE DEC 22 2015
ON WEDNESDAY NIGHT...A BROAD TROUGH OF LOW PRESSURE COVERS MUCH OF
THE WESTERN AND CENTRAL UNITED STATES...WITH A MOIST WESTERLY FLOW
ALOFT OVER COLORADO. IN ADDITION...A STRONG UPPER LEVEL JET STREAM
WILL BE ALONG THE NEW MEXICO BORDER...WITH AN UPPER LEVEL
DISTURBANCE MOVING ACROSS EASTERN COLORADO. THIS PATTERN SHOULD
PRODUCE SNOW AND BREEZY CONDITIONS ACROSS THE HIGH COUNTRY...WITH
THE POSSIBILITY FOR A FEW SNOW SHOWERS ACROSS THE PLAINS. THE SNOW
SHOULD DECREASE AFTER MIDNIGHT AS THE UPPER LEVEL DISTURBANCE MOVES
EAST OF COLORADO.
ON THURSDAY...THE UPPER TROUGH DEEPENS OVER THE WESTERN U.S. WITH
THE FLOW ALOFT OVER COLORADO BECOMING MORE SOUTHWESTERLY. THIS FLOW
IS NOT AS FAVORABLE FOR SNOW IN THE MOUNTAINS...HOWEVER THERE WILL
BE ENOUGH MOISTURE AVAILABLE TO PRODUCE SCATTERED SNOW SHOWERS
ACROSS THE HIGH COUNTRY.
ON CHRISTMAS DAY...THE UPPER TROUGH MOVES INTO COLORADO FROM THE
WEST...WITH QUITE A BIT OF QG LIFT MOVING ACROSS NORTH CENTRAL
AND NORTHEASTERN COLORADO. THIS QG-LIFT COMBINED WITH PLENTY OF
MOISTURE AND OROGRAPHIC LIFT SHOULD PRODUCE SNOW ACROSS THE
MOUNTAINS...HOWEVER THE SOUTHWEST FLOW ALOFT SHOULD LIMIT SNOWFALL
AMOUNTS. ONE THING TO NOTE IS THAT MODELS ARE SHOWING A 120KT JET
OVER CENTRAL COLORADO WHICH COULD ENHANCE SNOWFALL AMOUNTS SOUTH
OF INTERSTATE 70. FOR THE PLAINS...THE SOUTHWEST FLOW ALOFT IS NOT
FAVORABLE FOR SNOWFALL...HOWEVER...THERE SHOULD BE QUITE A BIT OF
QG- LIFT AROUND WHICH MAY BE ENOUGH TO PRODUCE SCATTERED LIGHT
SNOW SHOWERS.
MODELS ARE SHOWING A COLD FRONT MOVING INTO NORTHEASTERN COLORADO
FRIDAY NIGHT. NORTHERLY WINDS BEHIND THE FRONT...COMBINED WITH WEAK
QG LIFT MAY PRODUCE SOME LIGHT SNOW EAST OF THE MOUNTAINS ON
SATURDAY...MAINLY ALONG THE FRONT RANGE FOOTHILLS AND PALMER DIVIDE.
LOOKS LIKE THIS SYSTEM WONT BE MUCH OF AN IMPACT ACROSS OUR CWA DUE
TO THE FACT THAT THE MAIN UPPER LOW TRACKS ACROSS FAR SOUTHERN NEW
MEXICO AND INTO OKLAHOMA. THE MODELS ARE HINTING THE POSSIBILITY OF
SOME LIGHT SNOWFALL ACROSS OUR FAR EASTERN ZONES EARLY NEXT ON THE
BACK SIDE OF THIS STORM SYSTEM...THEREFORE WILL KEEP SOME LOW POPS
IN THESE AREAS.
TEMPERATURES ARE EXPECTED TO REMAIN MUCH BELOW NORMAL THROUGH THE
PERIOD. SATURDAY LOOKS TO BE THE COLDEST DAY...WITH DAYTIME HIGHS
POSSIBLY NOT MAKING IT OUT OF THE TEENS ON THE PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1249 AM MST WED DEC 23 2015
WITH CLEARING SKIES BEHIND THE EARLIER SNOWBAND...AREAS OF FOG ARE
BEGINNING TO FORM. HIRES MODELS ARE KEEPING STRONG ENOUGH
DOWNSLOPE WINDS IN FOR THE FOG TO STAY NORTH OR KDEN AND
KAPA...SHOULD MAINLY IMPACT KBJC AND NORTH. THOUGH CAN`T RULE OUT
FOG INTO THE OTHER AIRPORTS. HIRES MODELS ALSO BEING PERSISTENT
ABOUT ANOTHER BATCH OF SNOW SHOWERS PUSHING THROUGH BETWEEN
11-14Z...MAINLY METRO AREAS AND SOUTH. HAVE ADJUSTED TAFS FOR
THIS. NOT EXPECTING MUCH ACCUMULATION AS BEST DYNAMICS HAVE PUSHED
EAST. SKIES WILL THEN CLEAR AGAIN THROUGH WEDNESDAY MORNING AS
DOWNSLOPING WILL DEVELOP. DRAINAGE WINDS WILL VEER TO THE
NORTHWEST IN THE AFTERNOON. SLIGHT CHANCE TO SEE SOME SNOW SHOWERS
AGAIN...BUT NOT UNTIL LATE AFTERNOON OR EVENING. QUICK MVFR
CONDITIONS POSSIBLE WITH THESE SHOWERS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ031-033-
034.
&&
$$
UPDATE...KRIEDERMAN
SHORT TERM...BOWEN
LONG TERM...KALINA
AVIATION...KRIEDERMAN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1024 PM MST TUE DEC 22 2015
.UPDATE...
ISSUED AT 1010 PM MST TUE DEC 22 2015
RAPID ZONAL FLOW ALOFT EQUATES TO RAPID CHANGES IN OUR WEATHER
CONDITIONS THIS EVENING. BANDED SNOWFALL HANGING OVER NORTHERN
PORTIONS OF THE CWA ALL EVENING HAS MADE LITTLE SOUTHWARD PROGRESS
AS MESOSCALE MODELS INDICATED. ALTHOUGH IN THE PAST HOUR THE TAIL
END OF THIS SNOW BAND OVERT THE FRONT RANGE HAS SHOWN SIGNS OF
ADVANCING SOUTHWARD IN RESPONSE TO THE NEXT INFLUX OF PACIFIC
MOISTURE SPREADING INTO THE NORTH CENTRAL MTNS AT THIS HOUR.
SNOWFALL RATES UNDER THE SNOW BAND NORTH OF DENVER IN THE 0.5 TO 1
INCH PER HOUR RATE. SHOULD SEE SIMILAR SNOWFALL RATES DEVELOPING
THE HIGH COUNTRY OVER THE NEXT HOUR OR TWO...WITH POSSIBLY GREATER
RATES OVER THE HIGH TERRAIN IN SUMMIT AND WESTERN PARK COUNTIES.
HRRR AND RAP INDICATE THE HIGHEST 6-HR SNOW TOTALS ON THE PLAINS
ACROSS MORGAN...WASHINGTON AND LOGAN COUNTIES WHERE 1-3 INCH
AMOUNTS ARE POSSIBLE. CLOSER TO THE FRONT RANGE COULD ANOTHER
INCH OR TWO FROM DENVER NORTHWARD AND PERHAPS AND INCH OR SO IN
THE DENVER AREA BEFORE 10Z TONIGHT...THAT`S ASSUMING A SNOW BAND
FORMS FARTHER SOUTH AS THE HRRR AND RAP INDICATE. SHOULD SEE LIGHT
TO MODERATE SNOWFALL REST OF TONIGHT IN THE HIGH COUNTRY WHERE WE
COULD SEE ANOTHER 3-5 INCHES ON WEST FACING SLOPES BY MORNING.
UPDATED FORECAST WITH THESE CHANGES ALREADY OUT.
UPDATE ISSUED AT 748 PM MST TUE DEC 22 2015
SNOW OVER LARIMER AND WELD COUNTIES WILL TO SPREAD SOUTH AND EAST
THROUGH THE EVENING AND OVERNIGHT HOURS. THE 00Z SOUNDING SHOWED A
NEARLY DRY ADIABATIC LAPSE RATE FROM 750MB UP TO 300 MB...SO
HEAVY CONVECTIVE SNOW WILL REMAIN POSSIBLE WITH BRIEF SNOWFALL
RATES OF 1 TO 2 INCHES PER HOUR POSSIBLE. AN ESTIMATED HALF INCH
HAS FALLEN IN FORT COLLINS SO FAR BASED ON WEB CAMERAS. INCREASED
POPS AND SNOWFALL AMOUNTS EARLIER AND THEY STILL APPEAR ON TRACK.
UPDATE ISSUED AT 518 PM MST TUE DEC 22 2015
LATEST SHORT RANGE MODELS AND 18Z MODELS SHOWING MORE SNOW FOR
NORTHEAST COLORADO TONIGHT. FAVORABLE SIDE OF THE JET WILL BE OVER
THE AREA. IN ADDITION...AIRMASS WILL BE UNSTABLE WITH LAPSE RATES
OF 6 TO 8.5 C/KM. LATEST RADAR SHOWING INCREASING RETURNS...MOST
OF WHICH IS VIRGA OVER LARIMER AND WELD COUNTIES. AIRMASS WILL
CONTINUE TO MOISTEN AND EXPECT SNOW TO INCREASE THROUGH THE
EVENING HOURS. UPDATED TO INCREASE POPS INTO THE LIKELY RANGE.
MOST AREAS WILL SEE LIGHT SNOWFALL...AN INCH OR LESS. HOWEVER A
FEW SNOW BANDS WILL BE POSSIBLE WHERE UP TO 3 INCHES MAY FALL.
TEMPERATURES WILL BE IN THE UPPER 20S TO LOWER 30S. SO ROADS WILL
BE SLOW TO ICE UP EXCEPT UNDER THE HEAVIER SNOW BANDS. THIS
SYSTEM WILL BE QUICK MOVING AND BE OUT OF THE AREA BY SUNRISE.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 142 PM MST TUE DEC 22 2015
A BROAD UPPER LEVEL TROUGH CONTINUES TO BRING INCREASED MOISTURE
AND STRONG WNW WINDS INTO THE MOUNTAINS. SNOW SHOWERS AND GUSTY
WINDS WILL CONTINUE OVER THE MOUNTAINS THROUGH THE EVENING HOURS
BEFORE DIMINISHING OVERNIGHT. TOTAL ACCUMULATIONS WILL BE 8 TO 18
INCHES WITH THE HIGHER AMOUNTS OVER THE NORTHERN MOUNTAINS ON WEST
FACING SLOPES. AREAS NEAR THE PARK AND GORE RANGES IN THE NE
PORTIONS OF THE CWA COULD SEE UP TO 2 FEET ON WEST FACING SLOPES
THROUGH TOMORROW AFTERNOON. ON THE PLAINS THE SURFACE LOW THAT HAS
BEEN KEEPING SNOW OUT OF THE PICTURE WILL MOVE OFF TO THE SOUTH
AND EAST TONIGHT BRINGING SOME LIGHT FLURRIES TO THE NORTHERN
PLAINS. AREAS CLOSEST TO THE WYOMING BORDER WILL SEE A LITTLE
HIGHER AMOUNTS DUE TO SOME ENHANCED LIFT...HOWEVER AMOUNTS WILL BE
LIGHT WITH ACCUMULATIONS STAYING UNDER HALF AN INCH. TEMPERATURES
OVERNIGHT WILL BE COOL DUE TO THE COLD FRONT MOVING DOWN THIS
EVENING. LOWS FOR THE PLAINS WILL BE IN THE 20S AND SINGLE DIGITS
FOR THE MOUNTAINS.
FOR WEDNESDAY...THERE WILL BE A SLIGHT LULL IN THE SNOW INTENSITY
EARLY WEDNESDAY MORNING PRIOR TO THE NEXT UPPER LEVEL DISTURBANCE.
MODELS STILL SHOWING NEXT SHORTWAVE MOVING DOWN INTO COLORADO BY
THE AFTERNOON. THE JET WILL BE JUST TO THE SOUTH OF THE CWA BUT
LAPSE RATES ARE IMPRESSIVE AT 8-9 C/KM SO PERIODS OF CONVECTIVE
SNOW IS POSSIBLE WITH 1 INCH PER HOUR RATES DURING THE AFTERNOON
AT HIGHER ELEVATIONS. WITH THE NEXT WAVE UPPER LEVEL FLOW WILL
MOVE NW WHICH IS FAVORABLE FOR WEST FACING SLOPES. HIGHER SNOWFALL
AMOUNTS WILL BE POSSIBLE IN THESE AREAS. WILL KEEP THE WINTER
STORM WARNING FOR THE MOUNTAINS GOING UNTIL 6 PM DUE TO THE
CONVECTIVE NATURE AND THREAT OF BLOWING SNOW WITH THIS STORM.
FOR THE PLAINS THE FRONT WILL BRING A SLIGHT CHANCE OF SNOW BY THE
AFTERNOON AND EVENING WITH LIGHT ACCUMULATION EXPECTED. GFS IS
HINTING AT SOME QG MOVING OVER THE PLAINS IN THE AFTERNOON THAT
COULD BRING A SHORT PERIOD OF MORE INTENSE SNOWFALL THAT COULD
DROP A QUICK HALF INCH. SNOW WILL DECREASE IN THE EVENING WITH
SUBSIDENCE BEHIND THE FRONT. TEMPERATURES FOR WEDNESDAY WILL BE
SLIGHTLY COOLER IN THE UPPER 30S AND TEENS IN THE MOUNTAINS.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 142 PM MST TUE DEC 22 2015
ON WEDNESDAY NIGHT...A BROAD TROUGH OF LOW PRESSURE COVERS MUCH OF
THE WESTERN AND CENTRAL UNITED STATES...WITH A MOIST WESTERLY FLOW
ALOFT OVER COLORADO. IN ADDITION...A STRONG UPPER LEVEL JET STREAM
WILL BE ALONG THE NEW MEXICO BORDER...WITH AN UPPER LEVEL
DISTURBANCE MOVING ACROSS EASTERN COLORADO. THIS PATTERN SHOULD
PRODUCE SNOW AND BREEZY CONDITIONS ACROSS THE HIGH COUNTRY...WITH
THE POSSIBILITY FOR A FEW SNOW SHOWERS ACROSS THE PLAINS. THE SNOW
SHOULD DECREASE AFTER MIDNIGHT AS THE UPPER LEVEL DISTURBANCE MOVES
EAST OF COLORADO.
ON THURSDAY...THE UPPER TROUGH DEEPENS OVER THE WESTERN U.S. WITH
THE FLOW ALOFT OVER COLORADO BECOMING MORE SOUTHWESTERLY. THIS FLOW
IS NOT AS FAVORABLE FOR SNOW IN THE MOUNTAINS...HOWEVER THERE WILL
BE ENOUGH MOISTURE AVAILABLE TO PRODUCE SCATTERED SNOW SHOWERS
ACROSS THE HIGH COUNTRY.
ON CHRISTMAS DAY...THE UPPER TROUGH MOVES INTO COLORADO FROM THE
WEST...WITH QUITE A BIT OF QG LIFT MOVING ACROSS NORTH CENTRAL
AND NORTHEASTERN COLORADO. THIS QG-LIFT COMBINED WITH PLENTY OF
MOISTURE AND OROGRAPHIC LIFT SHOULD PRODUCE SNOW ACROSS THE
MOUNTAINS...HOWEVER THE SOUTHWEST FLOW ALOFT SHOULD LIMIT SNOWFALL
AMOUNTS. ONE THING TO NOTE IS THAT MODELS ARE SHOWING A 120KT JET
OVER CENTRAL COLORADO WHICH COULD ENHANCE SNOWFALL AMOUNTS SOUTH
OF INTERSTATE 70. FOR THE PLAINS...THE SOUTHWEST FLOW ALOFT IS NOT
FAVORABLE FOR SNOWFALL...HOWEVER...THERE SHOULD BE QUITE A BIT OF
QG- LIFT AROUND WHICH MAY BE ENOUGH TO PRODUCE SCATTERED LIGHT
SNOW SHOWERS.
MODELS ARE SHOWING A COLD FRONT MOVING INTO NORTHEASTERN COLORADO
FRIDAY NIGHT. NORTHERLY WINDS BEHIND THE FRONT...COMBINED WITH WEAK
QG LIFT MAY PRODUCE SOME LIGHT SNOW EAST OF THE MOUNTAINS ON
SATURDAY...MAINLY ALONG THE FRONT RANGE FOOTHILLS AND PALMER DIVIDE.
LOOKS LIKE THIS SYSTEM WONT BE MUCH OF AN IMPACT ACROSS OUR CWA DUE
TO THE FACT THAT THE MAIN UPPER LOW TRACKS ACROSS FAR SOUTHERN NEW
MEXICO AND INTO OKLAHOMA. THE MODELS ARE HINTING THE POSSIBILITY OF
SOME LIGHT SNOWFALL ACROSS OUR FAR EASTERN ZONES EARLY NEXT ON THE
BACK SIDE OF THIS STORM SYSTEM...THEREFORE WILL KEEP SOME LOW POPS
IN THESE AREAS.
TEMPERATURES ARE EXPECTED TO REMAIN MUCH BELOW NORMAL THROUGH THE
PERIOD. SATURDAY LOOKS TO BE THE COLDEST DAY...WITH DAYTIME HIGHS
POSSIBLY NOT MAKING IT OUT OF THE TEENS ON THE PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1010 PM MST TUE DEC 22 2015
SNOW CHANCES WILL INCREASE AT KBJC AND KDEN WITHIN THE HOUR WITH A
BAND OF LIGHT TO MODERATE SNOWFALL SWINGING OFF THE FRONT RANGE
AND ACROSS NORTHERN PORTIONS OF THE METRO AREA. CEILINGS HAVE
QUICKLY LOWERED IN THE PAST 30 MINS IN RESPONSE TO THE APPROACHING
SNOW BAND. COULD SEE A HALF INCH OF SNOW AT BOTH AIRPORTS BY THE
TIME THE BAND PASSES BY. COULD THEN SEE ANOTHER BAND OR TWO OF
SNOW PASS OVER THE METRO AREA LATER TONIGHT POSSIBLY DEPOSITING
ANOTHER 0.5 TO 1 INCH OF SNOW IN THE METRO AREA AND AT KDEN. ILS
CIGS AND VSBYS LIKELY WITH THESE PASSING SNOW BANDS. WINDS WILL
ALSO BE VARIABLE IN DIRECTION AT UNDER 12KTS WITH THESE SHOWERS.
AFTER 10Z WITH PARTIAL CLEARING SKIES COULD SEE PATCHY DENSE FOG
FORMING ACROSS NORTHERN PORTIONS OF THE METRO AREA. THAT INCLUDES
KDEN AND KBJC. COULD SEE VSBYS LOWERING TO 1.5-3 MILES IN THE FOG.
OTHERWISE S-SELY WINDS OF 5-8KTS WILL PREVAIL IN THE DENVER AREA
FOR THE REMAINDER OF THE NIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 PM MST WEDNESDAY FOR COZ031-033-034.
&&
$$
UPDATE...BAKER
SHORT TERM...BOWEN
LONG TERM...KALINA
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1028 AM EST WED DEC 23 2015
.SYNOPSIS...
UNUSUALLY WARM DECEMBER WEATHER WILL CONTINUE FOR THE NEXT SEVERAL
DAYS...PROBABLY BREAKING MANY RECORDS. PERIODS OF WET WEATHER WILL
ACCOMPANY THE WARMTH...MAINLY WEDNESDAY AFTERNOON AND EVENING...
AND AGAIN THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1030 AM UPDATE...
DENSE FOG HAS LIFTED EXCEPT ACROSS MUCH OF THE REGION WITH JUST
SOME LOWER VSBYS LINGERING IN PORTIONS OF THE CT VALLEY WHICH
SHOULD IMPROVE BY NOON. HOWEVER...FOG WILL LIKELY REDEVELOP LATER
TODAY INTO TONIGHT FROM SOUTH TO NORTH AS WARM FRONT
APPROACHES...AND AREAS OF DENSE FOG EXPECTED. USING THE HRRR FOR
TIMING OF RAINFALL HAS ONSET 19-20Z IN THE CT VALLEY THEN
OVERSPREADING REST OF SNE 21-23Z. TEMPS WILL BE TRICKY TODAY AND
MAY REMAIN IN THE UPPER 40S NEAR THE NH BORDER WHILE REACHING THE
MID/UPPER 50S BY LATE IN THE DAY NEAR THE S COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/...
TONIGHT...THE WARM FRONT MOVES NORTHWARD THROUGH SOUTHERN NEW
ENGLAND. WITH THAT...RAIN...FOG...AND WARM TEMPERATURES ARE
EXPECTED TO CONTINUE. WIDESPREAD RAIN WILL TRANSITION MORE TO
SHOWERS WITH THE POTENTIAL FOR THUNDER CONTINUING THROUGH THE NIGHT.
AN ADDITIONAL HALF AN INCH OF RAIN IS EXPECTED OVERNIGHT. EXPECT
WIDESPREAD AREAS OF FOG DURING THE OVERNIGHT...POTENTIALLY WITH
VISIBILITIES DOWN TO A QUARTER OF A MILE. TEMPERATURES WILL BE MILD
ONCE AGAIN...WITH A HIGH LIKELIHOOD OF BREAKING THE RECORD WARM LOW
TEMPERATURES. THE CURRENT RECORDS CAN BE FOUND BELOW IN THE CLIMATE
SECTION.
THURSDAY...AS WE REMAIN IN THE WARM SECTOR...EXPECT THIS TO BE THE
WARMEST DAY OF THE WEEK. SOUTHWESTERLY WINDS AND 925MB TEMPERATURES
BETWEEN 15 AND 16 DEG C WILL LEAD TO HIGH TEMPERATURES IN THE MID TO
UPPER 60S TO EVEN 70 DEGREES FOR MUCH OF SOUTHERN NEW ENGLAND. THIS
WOULD BE DESPITE OVERCAST SKIES AND RAIN. SHOULD THIS FORECAST COME
TO FRUITION /AND ALL INDICATIONS ARE IT WILL/...THIS WILL SHATTER
THE PREVIOUS RECORD HIGHS FOR THIS DATE. IN ADDITION...IT WILL BE
VERY HUMID...PARTICULARLY FOR DECEMBER...WITH DEWPOINTS IN THE 60S.
MUCH OF THE DAY SHOULD BE DRY...THOUGH THERE IS POTENTIAL FOR A FEW
LINGERING SHOWERS...PARTICULARLY EARLY IN THE DAY. FINALLY...A
STRONG LOW LEVEL JET WILL BE IN PLACE ALONG THE COAST.
HOWEVER...AN INVERSION WILL LIKELY LIMIT WIND GUSTS TO LESS THAN
30 MPH ACROSS THE CAPE AND ISLANDS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
HIGHLIGHTS...
* CONTINUED UNSEASONABLY MILD CHRISTMAS DAY
* FAST-MOVING AND ACTIVE PATTERN WILL BRING MULTIPLE PRECIPITATION
CHANCES THIS WEEKEND INTO EARLY NEXT WEEK
* UNSEASONABLY MILD AGAIN SUNDAY...THEN TURNING COLDER MONDAY
OVERVIEW...
RATHER GOOD AGREEMENT AMONG THE 23/00Z GUIDANCE SUITE FOR MOST OF
THIS PERIOD. HAVE ABOVE AVERAGE CONFIDENCE IN THE FORECAST INTO
SUNDAY. WILL FOLLOW A CONSENSUS SOLUTION FOR THIS PORTION OF THE
FORECAST.
BIG DIFFERENCES IN THE EVOLUTION OF THE MID LEVEL FLOW EARLY NEXT
WEEK. OPERATIONAL GFS IS MUCH MORE PROGRESSIVE THAN THE
INTERNATIONAL MODELS...AND EVEN THE GEFS MEAN. FLOW ALOFT SHOULD
BE FAST...SO CAN SEE REASONS WHY THE GFS WOULD BE SO PROGRESSIVE.
WITH LOWER CONFIDENCE IN THE DETAILS THOUGH...WILL ONLY TREND THE
FORECAST IN THAT DIRECTION.
PERSISTENT LARGE SUBTROPICAL RIDGE OFF SE US COAST WILL REMAIN
THROUGH THE EXTENDED PERIOD...WITH SOUTHERN NEW ENGLAND REMAINING
WITHIN THE UPPER LEVEL JET AXIS. THIS WILL RESULT IN MULTIPLE
PERIODS OF UNSETTLED WEATHER AND TEMPERATURES AVERAGING WELL ABOVE
NORMAL. GUIDANCE IS SIGNALING A SPLIT FLOW PATTERN DEVELOPING THIS
WEEKEND...WITH MORE OF A NORTHERN STREAM INFLUENCE EARLY NEXT
WEEK. THIS SHOULD LEAD TO A TEMPORARY RETURN TO MORE SEASONABLE
TEMPERATURES. ANY COOLING WILL BE SHORT-LIVED AS RIDGING BECOMES
RE-ESTABLISHED. DEPENDING ON TIMING OF NEXT SYSTEM LIFTING THROUGH
THE GREAT LAKES...THERE IS A CHANCE OF SOME WINTRY PRECIPITATION
EARLY NEXT WEEK. AGAIN...LOW CONFIDENCE IN THE DETAILS AT THIS
TIME RANGE.
DETAILS...
CHRISTMAS DAY...A WEAK FRONT WILL BE MOVING OFFSHORE...BUT
LIKELY STALLS JUST OFF THE COAST AS THERE IS NOT MUCH PUSH WITH SW
FLOW ALOFT. THINKING THERE WILL BE AT LEAST A BRIEF PERIOD OF
CLEARER SKIES. OVERRUNNING MOISTURE LIKELY RETURNS FRIDAY NIGHT.
CONSENSUS SOLUTIONS SUGGEST SOME SHOWERS MOVE IN FRIDAY NIGHT AS
WELL. IT WILL REMAIN UNSEASONABLY MILD. RECORD TEMPERATURES COULD
BE CHALLENGED AGAIN AT KPVD. SEE CLIMATE SECTION BELOW.
SATURDAY AND SUNDAY...
HIGH PRESSURE TO THE NORTH WILL MOVE OFFSHORE...ALLOWING THE FRONT
TO OUR SOUTH TO RETURN NORTH AS A WARM FRONT. MORE SHOWERS
EXPECTED SATURDAY INTO SATURDAY NIGHT...BUT EXACT TIMING IS
UNCERTAIN. A STRONG COLD FRONTAL PASSAGE SUNDAY WILL LEAD TO
ANOTHER PERIOD OF SHOWERS. STILL UNSEASONABLY WARM. THERE REMAINS
A CHANCE FOR NEAR RECORD WARMTH AGAIN AT ALL 4 CLIMATE SITES
SUNDAY.
MONDAY AND TUESDAY...
VERY STRONG HIGH PRESSURE BUILDS INTO OUR REGION FROM THE NORTH
MONDAY. THIS WILL LIKELY MEAN LOWER...BUT STILL SEASONABLE...
TEMPERATURES. THIS HIGH PRESSURE EVENTUALLY MOVES OFFSHORE.
DEPENDING ON HOW FAST A LOW PRESSURE MOVES THROUGH THE GREAT
LAKES...WE COULD SEE OUR FIRST LEGITIMATE SHOT A WINTRY WEATHER
SOMETIME DURING THIS PERIOD. IT IS MORE LIKELY ANY PRECIPITATION
WOULD BE ALL RAIN BY TUESDAY AFTERNOON. THIS POTENTIAL WILL NEED
TO BE MONITORED THIS WEEK. LOWEST CONFIDENCE PORTION OF THIS
FORECAST.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
TODAY...HIGH CONFIDENCE. PATCHY IFR FOG CT VALLEY WILL IMPROVE
AROUND MIDDAY...OTHERWISE A BRIEF PERIOD OF VFR EXPECTED INTO
THIS AFTERNOON BEFORE CONDITIONS DETERIORATE MID TO LATE AFTERNOON
WITH IFR STRATUS AND FOG AND RAIN DEVELOPING.
TONIGHT...HIGH CONFIDENCE. IFR CIGS/VSBYS EXPECTED IN RAIN/FOG WITH
SOME MARGINAL IMPROVEMENT TO MVFR BY 12Z THURSDAY ACROSS WESTERN
MA/CT. LOW PROBABILITY OF ISOLATED THUNDERSTORMS.
THURSDAY...MODERATE CONFIDENCE. OVERCAST SKIES WILL CONTINUE
THROUGH THE DAY BUT CONDITIONS SHOULD GRADUALLY IMPROVE FROM
MVFR/IFR TO VFR.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN EXACT
TIMING. FOG MAY DEVELOP AT THE TERMINAL THIS MORNING IF WINDS CALM.
ALSO COULD SEE FOG DEVELOP EARLIER THAN CURRENTLY FORECAST IN THE
TAF.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS. LOWER CONFIDENCE IN
EXACT TIMING. DENSE FOG MAY BE SLOW TO LIFT THIS MORNING.
OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/...
FRIDAY...MODERATE CONFIDENCE. MAINLY VFR.
SATURDAY AND SUNDAY...LOW CONFIDENCE ON TIMING AND DETAILS.
EXPECT PERIODS OF MVFR/IFR IN SHOWERS AND PATCHY FOG. GUSTY SW
WINDS POSSIBLE SUNDAY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
EASTERLY WINDS REMAIN LIGHT TODAY AND THEN GRADUALLY INCREASE AS
THEY SHIFT TO THE SOUTHWEST TONIGHT.. HOWEVER...THEY SHOULD
REMAIN BELOW 25 KTS UNTIL THURSDAY...WHEN THEY MAY GUST TO NEAR
25 KTS ON THE OUTER WATERS. PERSISTENT SOUTHERLY FLOW WILL LEAD TO
BUILDING SEAS THROUGHOUT THE PERIOD. SMALL CRAFT ADVISORIES ARE IN
PLACE FOR THE OUTER WATERS FOR SEAS AS WELL AS THE WIND GUSTS ON
THURSDAY.
OUTLOOK /THURSDAY NIGHT THROUGH SUNDAY/...
MODERATE OVERALL CONFIDENCE.
FRIDAY...WESTERLY WINDS BELOW 25 KT. ROUGH SEAS ACROSS THE OUTER
COASTAL WATERS SUBSIDING.
SATURDAY...MAINLY EASTERLY WINDS BELOW 25 KT. CHANCE OF LIGHT
RAIN WITH REDUCED VSBYS.
SUNDAY...GUSTY SW WINDS LIKELY REACHING 25-30 KT. LOW RISK WINDS
MAY REACH GALE FORCE.
&&
.CLIMATE...
RECORD HIGH MINIMUM TEMPERATURES FOR THURSDAY 12/24...
BOSTON 44/2003
PROVIDENCE 45/1941
HARTFORD 43/1931
WORCESTER 43/2003
RECORD HIGH TEMPERATURES FOR THURSDAY 12/24...
BOSTON 61/1996
PROVIDENCE64/2014
HARTFORD59/1996 AND 1990
WORCESTER57/1996 AND 1990
RECORD HIGH MINIMUM TEMPERATURES FOR FRIDAY 12/25...
BOSTON 44/2014
PROVIDENCE 46/1979
HARTFORD 43/2014
WORCESTER 47/1964
RECORD HIGH TEMPERATURES FOR FRIDAY 12/25...
BOSTON 65/1889
PROVIDENCE63/2014
HARTFORD64/1964
WORCESTER60/1964
RECORD HIGH TEMPERATURES FOR SUNDAY 12/27...
BOSTON 61/1949
PROVIDENCE59/1973
HARTFORD60/1949
WORCESTER 58/1895
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR ANZ235-237-
254>256.
SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 7 PM EST
THURSDAY FOR ANZ250.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 9 AM EST
THURSDAY FOR ANZ251.
&&
$$
SYNOPSIS...BELK/RLG
NEAR TERM...KJC/RLG
SHORT TERM...RLG
LONG TERM...BELK
AVIATION...KJC/BELK/RLG
MARINE...BELK/RLG
CLIMATE...
AREA FORECAST DISCUSSION
NWS MIAMI FL
143 PM EST WED DEC 23 2015
.AVIATION...
HIGH PRESSURE TO THE EAST WILL KEEP THE WIND OUT OF THE SOUTHEAST
THROUGH THE TAF PERIOD. EXPECT MOSTLY DRY CONDITIONS, BUT AN
ISOLATED SHOWER IS POSSIBLE. CURRENT FORECAST IS FOR VFR THROUGH
THE TAF PERIOD, BUT SOME LOCALIZED IFR DUE TO CIGS MAY BE POSSIBLE
ACROSS SOUTH FLORIDA, ESPECIALLY IN THE EARLY MORNING HOURS. THERE
IS ALSO A POSSIBILITY OF SOME FOG IN THE MORNING, MAINLY AT KAPF.
&&
.PREV DISCUSSION... /ISSUED 1108 AM EST WED DEC 23 2015/
UPDATE...
HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER PATTERN FOR SOUTH
FLORIDA TODAY. THIS WILL KEEP THE SOUTHEASTERLY WIND OVER THE
REGION. THIS WILL ALSO KEEP TEMPERATURES ON THE WARM SIDE FOR THE
NEXT FEW DAYS. WHILE NOT EXPECTING ANY SIGNIFICANT COVERAGE OF
SHOWERS, THERE IS A SLIGHT CHANCE OF SOME POP UP SHOWERS ACROSS
THE EASTERN HALF OF THE AREA. THE HRRR SHOWS INITIATION MAY BEGIN
EARLY THIS AFTERNOON. SO, HAVE KEPT THE 20 POPS ACROSS MOST OF THE
CWA. ALSO, THE RIP CURRENT RISK REMAINS HIGH TODAY, AND WILL
REMAIN ELEVATED THROUGH THE WEEKEND.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 77 86 77 86 / 10 10 20 20
FORT LAUDERDALE 77 84 76 83 / 10 10 20 20
MIAMI 77 86 77 84 / 10 10 20 20
NAPLES 70 88 70 86 / 0 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THURSDAY EVENING FOR FLZ168-172-
173.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...13/SI
LONG TERM....60/BD
AVIATION...13/SI
AREA FORECAST DISCUSSION
NWS MIAMI FL
1108 AM EST WED DEC 23 2015
.UPDATE...
HIGH PRESSURE REMAINS IN CONTROL OF THE WEATHER PATTERN FOR SOUTH
FLORIDA TODAY. THIS WILL KEEP THE SOUTHEASTERLY WIND OVER THE
REGION. THIS WILL ALSO KEEP TEMPERATURES ON THE WARM SIDE FOR THE
NEXT FEW DAYS. WHILE NOT EXPECTING ANY SIGNIFICANT COVERAGE OF
SHOWERS, THERE IS A SLIGHT CHANCE OF SOME POP UP SHOWERS ACROSS
THE EASTERN HALF OF THE AREA. THE HRRR SHOWS INITIATION MAY BEGIN
EARLY THIS AFTERNOON. SO, HAVE KEPT THE 20 POPS ACROSS MOST OF THE
CWA. ALSO, THE RIP CURRENT RISK REMAINS HIGH TODAY, AND WILL
REMAIN ELEVATED THROUGH THE WEEKEND.
&&
.PREV DISCUSSION... /ISSUED 600 AM EST WED DEC 23 2015/
AVIATION...
LESS SHOWER COVERAGE EXPECTED TODAY WITH LOWER POPS, AS A
RELATIVELY DRIER AIRMASS ARRIVES. STILL SOME MVFR CIGS ARE
POSSIBLE EARLY, ESPECIALLY AT APF. SUSTAINED WINDS MAY BE NEAR 20
KTS AT TIMES WITH GUSTS NEAR 30 KTS ALONG THE IMMEDIATE EAST COAST
TERMINALS PBI/FLL/FXE. WINDS WEAKEN SOMEWHAT TONIGHT. THERE COULD
ANOTHER ROUND OF MVFR CIGS AT APF LATE TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 87 77 86 77 / 20 10 10 20
FORT LAUDERDALE 83 77 84 76 / 20 10 10 20
MIAMI 85 77 86 77 / 20 10 10 20
NAPLES 87 70 88 70 / 10 0 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...HIGH RIP CURRENT RISK THROUGH THURSDAY EVENING FOR FLZ168-172-
173.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...13/SI
LONG TERM....60/BD
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
619 AM EST WED DEC 23 2015
.SYNOPSIS...
A WARM AND MOIST SOUTH FLOW WILL DOMINATE THROUGH MUCH OF THE WEEK
ASSOCIATED WITH OFFSHORE HIGH PRESSURE. NUMEROUS SHOWERS WILL
OCCUR TODAY AND TONIGHT WITH SOME DECREASE IN COVERAGE THURSDAY AS
UPPER RIDGING BECOMES A BIT MORE ESTABLISHED. VERY HEAVY RAIN MAY
OCCUR WITH SOME OF THE SHOWERS TODAY AND TONIGHT. MUCH ABOVE
NORMAL TEMPERATURES WILL CONTINUE.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH LOW-LEVEL MOISTURE HAS RESULTED IN DENSE FOG OVER MUCH OF THE
FORECAST AREA. THE GFS LAMP MAINTAINS SIGNIFICANT FOG THROUGH
MUCH OF THE MORNING. WE HAVE POSTED A DENSE FOG ADVISORY.
MOISTURE WILL REMAIN VERY HIGH THROUGH TONIGHT ASSOCIATED
WITH THE SOUTHERLY FLOW FROM OFF THE ATLANTIC AND GULF PLUS
SOUTHWEST MID- LEVEL FLOW ORIGINATING FROM THE TROPICAL PACIFIC.
THE MODELS AND OBSERVATION TRENDS INDICATE PRECIPITABLE WATER NEAR
1.9 OF AN INCH. THE NAM AND GFS INDICATE THE H85 FLOW INCREASING
TODAY WITH SPEEDS THIS AFTERNOON AND TONIGHT OF 40 TO 50 KNOTS.
THE STRONG JET AND HIGH MOISTURE INDICATE POSSIBLE EXCESSIVE RAIN
AND A FLASH FLOOD WATCH HAS BEEN POSTED. THE HIGH-RESOLUTION
MODELS HAVE NOT BEEN CONSISTENT WITH THE TIMING OF GREATEST SHOWER
COVERAGE. THE 07Z HRRR DISPLAYED SCATTERED COVERAGE WITH SOME
INCREASE DURING THE AFTERNOON. RADAR TRENDS SUPPORT NUMEROUS
SHOWERS IN THE NEAR TERM. USED THE WPC GUIDANCE FOR THE GENERAL
RAINFALL FORECAST. THE STRONG SHEAR INDICATES A POSSIBILITY OF
SEVERE THUNDERSTORMS BUT THE THREAT APPEARS LIMITED BY A LACK OF
SIGNIFICANT SURFACE- BASED INSTABILITY BECAUSE OF CLOUD COVER AND
NUMEROUS SHOWERS. THE GFS LAMP AND NAM BUFKIT MOMENTUM TRANSFER
TOOL INDICATE WIND GUSTS OF 18 TO 25 KNOTS THIS AFTERNOON. LEANED
TOWARD THE LOWER VALUES BECAUSE OF EXPECTED CLOUDINESS AND LIMITED
MIXING. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE OFF THE COAST WILL CONTINUE TO CIRCULATE A
MOIST SOUTH FLOW INTO THE FORECAST AREA THROUGH THURSDAY NIGHT
SUPPORTING SHOWERS. HOWEVER...THE MODELS HAVE BEEN CONSISTENT
INDICATING UPPER HEIGHTS BUILDING OVER THE FORECAST AREA FROM THE
SOUTHEAST. THE DIMINISHING UPPER SUPPORT SHOULD HELP DECREASE
SHOWER COVERAGE. THE NAM...GFS...AND ECMWF MOS INDICATE CHANCE
POPS. THE BUILDING UPPER RIDGE AND SOUTH FLOW WILL BRING MUCH
ABOVE NORMAL TEMPERATURES AND RECORDS FOR THE DATE MAY OCCUR. USED
THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE FORECAST WITH
EXPECTED LINGERING CLOUDINESS LIMITING HIGH TEMPERATURES. HIGH
LOW-LEVEL MOISTURE SHOULD RESULT IN WIDESPREAD STRATUS AND FOG
DURING THE EARLY MORNING HOURS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE GFS AND ECMWF INDICATE UPPER RIDGING ESTABLISHED OVER THE
FORECAST AREA FRIDAY THROUGH SUNDAY. HOWEVER...THE WARM AND MOIST
SOUTH FLOW ASSOCIATED WITH OFFSHORE SURFACE HIGH PRESSURE SUPPORTS
POSSIBLE SHOWERS. THE GFS AND ECMWF MOS HAVE POPS OF 20 TO 30
PERCENT. THE MOS MAINTAINS MUCH ABOVE NORMAL TEMPERATURES.
THE MODELS INDICATE A WEAKENED UPPER RIDGE MONDAY AND TUESDAY. THE
MODELS HAVE NOT BEEN CONSISTENT WITH THE POSITION OF A FRONTAL
SYSTEM BUT DO GENERALLY INDICATE INCREASED MOISTURE. THE GFS AND
ECMWF MOS HAVE POPS OF 20 TO 50 PERCENT WITH CONTINUED ABOVE
NORMAL TEMPERATURES.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
WIDESPREAD PROLONGED IFR/LIFR CONDITIONS EXPECTED EARLY THIS
MORNING...WITH SOME IMPROVEMENT LATER TODAY.
IFR/LIFR CONDITIONS ACROSS THE AREA EARLY THIS MORNING. LATEST RADAR
MOSAIC INDICATING MAINLY LIGHT RAIN ACROSS THE AREA. OVERALL DO NOT
EXPECT MUCH IN THE WAY OF IMPROVEMENT BEFORE SUNRISE. SFC WRF MODEL
INDICATING ONE BAND OF PRECIPITATION MOVING THROUGH THE AREA LATER
THIS MORNING AND ANOTHER BAND MOVING THROUGH EARLY THIS
EVENING...BUT OTHER SHORT-TERM MODELS ARE SHOWING SOME DIFFERENCES.
AS A RESULT...CONSIDERABLE UNCERTAINTIES REMAIN WITH REGARDS TO
PLACEMENT...TIMING...AND INTENSITY OF PRECIPITATION. AT THIS
TIME...WILL HANDLE PRECIPITATION WITH VCSH. UNCERTAINTIES ALSO
REMAIN HOW MUCH CIGS/VSBYS WILL IMPROVE LATER TODAY. MODEL GUIDANCE
HINTING THAT CONDITIONS MAY IMPROVE TO MVFR LATER THIS AFTERNOON.
FOR NOW WILL LEAN TOWARDS HIGH-END IFR/MVFR THIS AFTERNOON.
CONDITIONS MAY DETERIORATE AGAIN TONIGHT BUT UNCERTAINTIES LINGER
DUE TO MODELS KEEPING SFC WINDS UP A BIT THIS EVENING INTO TONIGHT.
EXTENDED AVIATION OUTLOOK...CHANCE OF RAIN...AND MAINLY LATE NIGHT
AND MORNING RESTRICTIONS...LATE TONIGHT THROUGH MONDAY.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS HAVE BEEN POSTED FOR SOME OF THE RIVER
FORECAST POINTS. FLASH FLOOD WARNINGS MAY BE REQUIRED AT TIMES
THROUGH TONIGHT...MAINLY FOR SMALL STREAMS AND URBAN LOCATIONS.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR CHRISTMAS EVE AND CHRISTMAS DAY.
COLUMBIA METRO AIRPORT (CAE)
DEC 24...76 SET IN 1964. FORECASTING 80.
DEC 25...79 SET IN 1955. FORECASTING 81.
AUGUSTA BUSH FIELD (AGS)
DEC 24...80 SET IN 1964. FORECASTING 80.
DEC 25...79 SET IN 1984. FORECASTING 81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040-
063>065-077.
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR GAZ040-
063>065.
SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016-
018-020>022-025>031-035>038-041.
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR SCZ015-016-
018-020>022-025>028-030.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
614 AM EST WED DEC 23 2015
.SYNOPSIS...
A WARM AND MOIST SOUTH FLOW WILL DOMINATE THROUGH MUCH OF THE WEEK
ASSOCIATED WITH OFFSHORE HIGH PRESSURE. NUMEROUS SHOWERS WILL
OCCUR TODAY AND TONIGHT WITH SOME DECREASE IN COVERAGE THURSDAY AS
UPPER RIDGING BECOMES A BIT MORE ESTABLISHED. VERY HEAVY RAIN MAY
OCCUR WITH SOME OF THE SHOWERS TODAY AND TONIGHT. MUCH ABOVE
NORMAL TEMPERATURES WILL CONTINUE.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH LOW-LEVEL MOISTURE HAS RESULTED IN DENSE FOG OVER MUCH OF THE
FORECAST AREA. THE GFS LAMP MAINTAINS SIGNIFICANT FOG THROUGH
MUCH OF THE MORNING. WE HAVE POSTED A DENSE FOG ADVISORY.
MOISTURE WILL REMAIN VERY HIGH THROUGH TONIGHT ASSOCIATED
WITH THE SOUTHERLY FLOW FROM OFF THE ATLANTIC AND GULF PLUS
SOUTHWEST MID- LEVEL FLOW ORIGINATING FROM THE TROPICAL PACIFIC.
THE MODELS AND OBSERVATION TRENDS INDICATE PRECIPITABLE WATER NEAR
1.9 OF AN INCH. THE NAM AND GFS INDICATE THE H85 FLOW INCREASING
TODAY WITH SPEEDS THIS AFTERNOON AND TONIGHT OF 40 TO 50 KNOTS.
THE STRONG JET AND HIGH MOISTURE INDICATE POSSIBLE EXCESSIVE RAIN
AND A FLASH FLOOD WATCH HAS BEEN POSTED. THE HIGH-RESOLUTION
MODELS HAVE NOT BEEN CONSISTENT WITH THE TIMING OF GREATEST SHOWER
COVERAGE. THE 07Z HRRR DISPLAYED SCATTERED COVERAGE WITH SOME
INCREASE DURING THE AFTERNOON. RADAR TRENDS SUPPORT NUMEROUS
SHOWERS IN THE NEAR TERM. USED THE WPC GUIDANCE FOR THE GENERAL
RAINFALL FORECAST. THE STRONG SHEAR INDICATES A POSSIBILITY OF
SEVERE THUNDERSTORMS BUT THE THREAT APPEARS LIMITED BY A LACK OF
SIGNIFICANT SURFACE- BASED INSTABILITY BECAUSE OF CLOUD COVER AND
NUMEROUS SHOWERS. THE GFS LAMP AND NAM BUFKIT MOMENTUM TRANSFER
TOOL INDICATE WIND GUSTS OF 18 TO 25 KNOTS THIS AFTERNOON. LEANED
TOWARD THE LOWER VALUES BECAUSE OF EXPECTED CLOUDINESS AND LIMITED
MIXING. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE OFF THE COAST WILL CONTINUE TO CIRCULATE A
MOIST SOUTH FLOW INTO THE FORECAST AREA THROUGH THURSDAY NIGHT
SUPPORTING SHOWERS. HOWEVER...THE MODELS HAVE BEEN CONSISTENT
INDICATING UPPER HEIGHTS BUILDING OVER THE FORECAST AREA FROM THE
SOUTHEAST. THE DIMINISHING UPPER SUPPORT SHOULD HELP DECREASE
SHOWER COVERAGE. THE NAM...GFS...AND ECMWF MOS INDICATE CHANCE
POPS. THE BUILDING UPPER RIDGE AND SOUTH FLOW WILL BRING MUCH
ABOVE NORMAL TEMPERATURES AND RECORDS FOR THE DATE MAY OCCUR. USED
THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE FORECAST WITH
EXPECTED LINGERING CLOUDINESS LIMITING HIGH TEMPERATURES. HIGH
LOW-LEVEL MOISTURE SHOULD RESULT IN WIDESPREAD STRATUS AND FOG
DURING THE EARLY MORNING HOURS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE GFS AND ECMWF INDICATE UPPER RIDGING ESTABLISHED OVER THE
FORECAST AREA FRIDAY THROUGH SUNDAY. HOWEVER...THE WARM AND MOIST
SOUTH FLOW ASSOCIATED WITH OFFSHORE SURFACE HIGH PRESSURE SUPPORTS
POSSIBLE SHOWERS. THE GFS AND ECMWF MOS HAVE POPS OF 20 TO 30
PERCENT. THE MOS MAINTAINS MUCH ABOVE NORMAL TEMPERATURES.
THE MODELS INDICATE A WEAKENED UPPER RIDGE MONDAY AND TUESDAY. THE
MODELS HAVE NOT BEEN CONSISTENT WITH THE POSITION OF A FRONTAL
SYSTEM BUT DO GENERALLY INDICATE INCREASED MOISTURE. THE GFS AND
ECMWF MOS HAVE POPS OF 20 TO 50 PERCENT WITH CONTINUED ABOVE
NORMAL TEMPERATURES.
&&
.AVIATION /11Z WEDNESDAY THROUGH SUNDAY/...
WIDESPREAD PROLONGED LIFR CONDITIONS EXPECTED EARLY THIS
MORNING...WITH CONDITIONS AT OR BELOW AIRPORT MINIMUMS POSSIBLE...
SOME IMPROVEMENT LATER TODAY.
IFR/LIFR CONDITIONS ACROSS THE AREA EARLY THIS MORNING. LATEST RADAR
MOSAIC INDICATING MAINLY LIGHT RAIN ACROSS THE AREA. OVERALL DO NOT
EXPECT MUCH IN THE WAY OF IMPROVEMENT BEFORE SUNRISE. SFC WRF MODEL
INDICATING ONE BAND OF PRECIPITATION MOVING THROUGH THE AREA LATER
THIS MORNING AND ANOTHER BAND MOVING THROUGH EARLY THIS
EVENING...BUT OTHER SHORT-TERM MODELS ARE SHOWING SOME DIFFERENCES.
AS A RESULT...CONSIDERABLE UNCERTAINTIES REMAIN WITH REGARDS TO
PLACEMENT...TIMING...AND INTENSITY OF PRECIPITATION. AT THIS
TIME...WILL HANDLE PRECIPITATION WITH VCSH. UNCERTAINTIES ALSO
REMAIN HOW MUCH CIGS/VSBYS WILL IMPROVE LATER TODAY. MODEL GUIDANCE
HINTING THAT CONDITIONS MAY IMPROVE TO MVFR LATER THIS AFTERNOON.
FOR NOW WILL LEAN TOWARDS HIGH-END IFR/MVFR THIS AFTERNOON.
CONDITIONS MAY DETERIORATE AGAIN TONIGHT BUT UNCERTAINTIES LINGER
DUE TO MODELS KEEPING SFC WINDS UP A BIT THIS EVENING INTO TONIGHT.
EXTENDED AVIATION OUTLOOK...CHANCE OF RAIN...AND MAINLY LATE NIGHT
AND MORNING RESTRICTIONS...LATE TONIGHT THROUGH MONDAY.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS HAVE BEEN POSTED FOR SOME OF THE RIVER
FORECAST POINTS. FLASH FLOOD WARNINGS MAY BE REQUIRED AT TIMES
THROUGH TONIGHT...MAINLY FOR SMALL STREAMS AND URBAN LOCATIONS.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR CHRISTMAS EVE AND CHRISTMAS DAY.
COLUMBIA METRO AIRPORT (CAE)
DEC 24...76 SET IN 1964. FORECASTING 80.
DEC 25...79 SET IN 1955. FORECASTING 81.
AUGUSTA BUSH FIELD (AGS)
DEC 24...80 SET IN 1964. FORECASTING 80.
DEC 25...79 SET IN 1984. FORECASTING 81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040-
063>065-077.
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR GAZ040-
063>065.
SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016-
018-020>022-025>031-035>038-041.
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR SCZ015-016-
018-020>022-025>028-030.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
412 AM EST WED DEC 23 2015
.SYNOPSIS...
A WARM AND MOIST SOUTH FLOW WILL DOMINATE THROUGH MUCH OF THE WEEK
ASSOCIATED WITH OFFSHORE HIGH PRESSURE. NUMEROUS SHOWERS WILL
OCCUR TODAY AND TONIGHT WITH SOME DECREASE IN COVERAGE THURSDAY AS
UPPER RIDGING BECOMES A BIT MORE ESTABLISHED. VERY HEAVY RAIN MAY
OCCUR WITH SOME OF THE SHOWERS TODAY AND TONIGHT. MUCH ABOVE
NORMAL TEMPERATURES WILL CONTINUE.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH LOW-LEVEL MOISTURE HAS RESULTED IN DENSE FOG OVER MUCH OF THE
FORECAST AREA. THE GFS LAMP MAINTAINS SIGNIFICANT FOG THROUGH
MUCH OF THE MORNING. WE HAVE POSTED A DENSE FOG ADVISORY.
MOISTURE WILL REMAIN VERY HIGH THROUGH TONIGHT ASSOCIATED
WITH THE SOUTHERLY FLOW FROM OFF THE ATLANTIC AND GULF PLUS
SOUTHWEST MID- LEVEL FLOW ORIGINATING FROM THE TROPICAL PACIFIC.
THE MODELS AND OBSERVATION TRENDS INDICATE PRECIPITABLE WATER NEAR
1.9 OF AN INCH. THE NAM AND GFS INDICATE THE H85 FLOW INCREASING
TODAY WITH SPEEDS THIS AFTERNOON AND TONIGHT OF 40 TO 50 KNOTS.
THE STRONG JET AND HIGH MOISTURE INDICATE POSSIBLE EXCESSIVE RAIN
AND A FLASH FLOOD WATCH HAS BEEN POSTED. THE HIGH-RESOLUTION
MODELS HAVE NOT BEEN CONSISTENT WITH THE TIMING OF GREATEST SHOWER
COVERAGE. THE 07Z HRRR DISPLAYED SCATTERED COVERAGE WITH SOME
INCREASE DURING THE AFTERNOON. RADAR TRENDS SUPPORT NUMEROUS
SHOWERS IN THE NEAR TERM. USED THE WPC GUIDANCE FOR THE GENERAL
RAINFALL FORECAST. THE STRONG SHEAR INDICATES A POSSIBILITY OF
SEVERE THUNDERSTORMS BUT THE THREAT APPEARS LIMITED BY A LACK OF
SIGNIFICANT SURFACE- BASED INSTABILITY BECAUSE OF CLOUD COVER AND
NUMEROUS SHOWERS. THE GFS LAMP AND NAM BUFKIT MOMENTUM TRANSFER
TOOL INDICATE WIND GUSTS OF 18 TO 25 KNOTS THIS AFTERNOON. LEANED
TOWARD THE LOWER VALUES BECAUSE OF EXPECTED CLOUDINESS AND LIMITED
MIXING. USED THE GUIDANCE CONSENSUS FOR THE TEMPERATURE FORECAST.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
SURFACE HIGH PRESSURE OFF THE COAST WILL CONTINUE TO CIRCULATE A
MOIST SOUTH FLOW INTO THE FORECAST AREA THROUGH THURSDAY NIGHT
SUPPORTING SHOWERS. HOWEVER...THE MODELS HAVE BEEN CONSISTENT
INDICATING UPPER HEIGHTS BUILDING OVER THE FORECAST AREA FROM THE
SOUTHEAST. THE DIMINISHING UPPER SUPPORT SHOULD HELP DECREASE
SHOWER COVERAGE. THE NAM...GFS...AND ECMWF MOS INDICATE CHANCE
POPS. THE BUILDING UPPER RIDGE AND SOUTH FLOW WILL BRING MUCH
ABOVE NORMAL TEMPERATURES AND RECORDS FOR THE DATE MAY OCCUR. USED
THE GUIDANCE CONSENSUS FOR THE HIGH TEMPERATURE FORECAST WITH
EXPECTED LINGERING CLOUDINESS LIMITING HIGH TEMPERATURES. HIGH
LOW-LEVEL MOISTURE SHOULD RESULT IN WIDESPREAD STRATUS AND FOG
DURING THE EARLY MORNING HOURS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
THE GFS AND ECMWF INDICATE UPPER RIDGING ESTABLISHED OVER THE
FORECAST AREA FRIDAY THROUGH SUNDAY. HOWEVER...THE WARM AND MOIST
SOUTH FLOW ASSOCIATED WITH OFFSHORE SURFACE HIGH PRESSURE SUPPORTS
POSSIBLE SHOWERS. THE GFS AND ECMWF MOS HAVE POPS OF 20 TO 30
PERCENT. THE MOS MAINTAINS MUCH ABOVE NORMAL TEMPERATURES.
THE MODELS INDICATE A WEAKENED UPPER RIDGE MONDAY AND TUESDAY. THE
MODELS HAVE NOT BEEN CONSISTENT WITH THE POSITION OF A FRONTAL
SYSTEM BUT DO GENERALLY INDICATE INCREASED MOISTURE. THE GFS AND
ECMWF MOS HAVE POPS OF 20 TO 50 PERCENT WITH CONTINUED ABOVE
NORMAL TEMPERATURES.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
WIDESPREAD PROLONGED LIFR CONDITIONS EXPECTED EARLY THIS
MORNING...WITH CONDITIONS AT OR BELOW AIRPORT MINIMUMS POSSIBLE.
IFR/LIFR CONDITIONS ACROSS THE AREA EARLY THIS MORNING...WITH THE
EXCEPTION OF OGB WITH MVFR. LATEST RADAR MOSAIC INDICATING MAINLY
LIGHT RAIN ACROSS THE AREA. OVERALL DO NOT EXPECT MUCH IN THE WAY OF
IMPROVEMENT BEFORE SUNRISE. LATEST HRRR INDICATING THE BEST CHANCE
FOR THE HEAVIEST PRECIPITATION MOVING BACK INTO THE AREA WILL BE
LATE MORNING INTO THE AFTERNOON. HOWEVER...CONSIDERABLE
UNCERTAINTIES REMAIN WITH REGARDS TO PLACEMENT...TIMING...AND
INTENSITY. UNCERTAINTIES ALSO REMAIN HOW MUCH CIGS/VSBYS WILL
IMPROVE LATER TODAY. MODEL GUIDANCE HINTING THAT CONDITIONS MAY
IMPROVE TO MVFR LATER THIS AFTERNOON. FOR NOW WILL LEAN TOWARDS HIGH-
END IFR/MVFR THIS AFTERNOON.
EXTENDED AVIATION OUTLOOK...CHANCE OF RAIN...AND MAINLY LATE NIGHT
AND MORNING RESTRICTIONS...WEDNESDAY NIGHT THROUGH MONDAY.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS HAVE BEEN POSTED FOR SOME OF THE RIVER
FORECAST POINTS. FLASH FLOOD WARNINGS MAY BE REQUIRED AT TIMES
THROUGH TONIGHT...MAINLY FOR SMALL STREAMS AND URBAN LOCATIONS.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR CHRISTMAS EVE AND CHRISTMAS DAY.
COLUMBIA METRO AIRPORT (CAE)
DEC 24...76 SET IN 1964. FORECASTING 80.
DEC 25...79 SET IN 1955. FORECASTING 81.
AUGUSTA BUSH FIELD (AGS)
DEC 24...80 SET IN 1964. FORECASTING 80.
DEC 25...79 SET IN 1984. FORECASTING 81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ040-
063>065-077.
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR GAZ040-
063>065.
SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ015-016-
018-020>022-025>031-035>038-041.
FLASH FLOOD WATCH THROUGH THURSDAY AFTERNOON FOR SCZ015-016-
018-020>022-025>028-030.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
501 PM CST WED DEC 23 2015
.SHORT TERM...(Tonight)
ISSUED AT 312 PM CST WED DEC 23 2015
First round of severe weather has exited the eastern forecast area
early this afternoon, but storms have quickly started to fire in
northeast Missouri. This particular area has seen some sunshine
during the afternoon, helping to destabilize the atmosphere, where
CAPE`s are above 500 J/kg and 0-6km bulk shear is an impressive 60-
70 knots. HRRR latched onto this area of development earlier, and
races it across the northern part of the forecast area between 4 pm
and 8 pm. Have concentrated the highest PoP`s for the rest of the
afternoon in this area. The storms should be weakening after sunset
as the surface low pulls northeast, and there is some question about
how much the atmosphere across the eastern CWA can recover after
being thoroughly worked over the last several hours.
Secondary concern is with the winds this evening. Have issued a Wind
Advisory for the period from 6 pm to 2 am across about the northwest
half of the forecast area. Main surface low is currently located
across northeast Iowa, and will be zipping northeast. Impressive 3-
hour pressure rises of 10-11 mb are progged to track northeastward
to around Rockford by midnight. Wind gusts of 45 mph or so are
likely across the northwest half of the forecast area as this
bullseye passes. Have gone as far south as Jacksonville with the
advisory, but this area may be of a shorter duration. Most of the
winds should be diminishing around midnight, but will linger a bit
longer north of I-74.
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 312 PM CST WED DEC 23 2015
Short and medium range models are in fairly good agreement with the
overall active weather pattern through the weekend and into early
next week. Unseasonably warm temperatures and very wet weather will
be the main factors for the weekend through late Monday.
In the shorter term, mild temperatures and periods of cloudiness can
be expected for Christmas Eve into much of Christmas Day. The return
of a surface boundary north of the Ohio Valley and associated weak
isentropic lift initially will result in a chance for light rain in
southeast IL late on Christmas Day. The GFS is the odd model out on
this one by keeping the boundary much farther south.
Backing upper level flow in response to a digging trough in the
western U.S. will allow very warm and moist air to return into much
of central and SE IL during the day Saturday. This feed of moisture
and the associated rainfall will linger in the forecast area through
most of Sunday, resulting in 2.50 to 3.50 inches of rain. The
precipitation area will gradually sag south as the upper low in the
west closes off in SW Texas and an upper level confluent area sets
up across central IL by later in the day Sunday.
The upper low in the southwestern U.S. is expected to kick out
toward the Midwest Monday as another strong upper level trough digs
from the Pacific NW to the southern Plains. This will bring the
likelihood of precipitation back to central IL for Monday. The
forecast type becomes a bit tricky north of a Rushville-Bloomington
line Monday into Monday night as upper level soundings indicate a
mix of rain/snow/sleet possible. Could be some minor accumulations
of snow NW of Peoria late Monday, but there is a lot of uncertainty
with this scenario 6 days out.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
ISSUED AT 500 PM CST WED DEC 23 2015
Cold front pushing into extreme west central Illinois will sweep
across the forecast area over the next several hours accompanied
by widely scattered showers and storms and strong gradient winds.
Look for south winds to veer more south-southwest and increase
to between 25 to 35 kts with gusts near 45 kts at times before
diminishing after 07z. Latest satellite data and surface obs to
our west indicate another band of MVFR cigs approaching the river
and based on timing, should begin to affect PIA and SPI by 01z,
BMI to CMI by 02z. Bases should run from 1000-2000 feet with about
a 3-5 hour stay in our TAF area before VFR conditions return after
07z.
&&
.ILX Watches/Warnings/Advisories...
Wind Advisory until 2 AM CST Thursday for ILZ027>031-036>038-
040>043-047>050.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Miller
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
413 PM CST WED DEC 23 2015
.MESOSCALE DISCUSSION...
242 PM CST
FIRST ROUND OF THUNDERSTORMS HAS PUSHED OFF TO THE EAST WITH
STRATIFORM RAIN IN PLACE ACROSS PORTIONS OF EAST CENTRAL ILLINOIS
AND NORTHWEST INDIANA. LOW PRESSURE IS ANALYZED JUST SOUTH OF
KDSM THIS AFTERNOON WITH A FRONTAL BOUNDARY STRETCHING SOUTH
ACROSS MISSOURI. VISIBLE SATELLITE IMAGERY SHOWS TOWERING CU AND A
FEW CB/S IMMEDIATELY AHEAD OF THE FRONT WHERE SURFACE TEMPS ARE IN
THE MID 60S AND DEWPOINTS IN THE LOW TO MID 50S. 18Z SPECIAL
SOUNDING OUT OF KDVN SHOWED AROUND 250 J/KG SBCAPE WITH FAIRLY
INTENSE DEEP LAYER SHEAR IN EXCESS OF 70KT. WATER VAPOR IMAGERY
SHOWS A DRY SLOT WRAPPING INTO NORTHEASTERN MISSOURI AND
SOUTHEASTERN COINCIDENT WITH THE CORRIDOR OF MODEST INSTABILITY OF
200-600 J/KG MLCAPE WHICH RAP GUIDANCE SHOWS LIFTING ACROSS
PORTIONS OF NORTH CENTRAL ILLINOIS WITHIN THE NEXT FEW HOURS.
STRONG PRESSURE FALLS AHEAD OF THE LOW MAY HELP TO KEEP WINDS
BACKED ACROSS NORTH CENTRAL ILLINOIS WHICH WILL LOCALLY ENHANCE
THE THREAT FOR SUPERCELLS ALONG WITH THE POSSIBILITY OF AN
ISOLATED TORNADO. A BIT HARD TO TELL HOW FAR EAST THE SEVERE
THREAT WILL EXTEND THIS AFTERNOON AND EVENING...THOUGH HI- RES
MODELS HAVE CONSISTENTLY SHOWED A WEAKENING TREND AS THUNDERSTORMS
APPROACH THE CHICAGO METRO AREA THIS EVENING. FOR NOW AM MOST
CONCERNED ABOUT SEVERE WEATHER WEST OF A PONTIAC TO WOODSTOCK
LINE...BUT CERTAINLY NOT OUT OF THE WOODS FARTHER EAST.
DEUBELBEISS
&&
.SHORT TERM...
236 PM CST
THROUGH THURSDAY...
A DEEP UPPER TROUGH IS OVER THE CENTRAL CONUS WITH A STRONG MID
LEVEL SHORTWAVE TRACKING NEWD THROUGH THE UPPER MISSOURI VALLEY. A
SERIES OF WEAKER SHORTWAVES HAVE BEEN TRACKING NEWD THROUGH THE
MIDDLE MISSISSIPPI VALLEY...GENERATING SCT STRONG THUNDERSTORMS AS
FAR NORTH AS NERN IL AND NWRN IN EARLIER TODAY. THE SRN STREAM
SHORTWAVE ENERGY IS BEGINNING TO FOCUS TSRA OVER THE LOWER OHIO
VALLEY AND INTO INDIANA THIS AFTERNOON AND THE MAIN AREA OF CONCERN
WITH RESPECT TO TSRA ACTIVITY FOR THE LOCAL AREA WILL BE UNDER THE
MID LEVEL CIRCULATION CENTER. UNDER THE COLD CORE UPPER LOW AND
WITH UNSEASONABLY WARM...MOIST AIR IN PLACE OVER THE REGION...STRONG
LAPSE RATES AND MODEST LOW LEVEL INSTABILITY WILL KEEP A CHANCE FOR
THUNDERSTORMS INTO THE EVENING HOURS. THE LATEST SATELLITE IMAGERY
SHOWS SOME BREAKS IN THE OVERCAST UNDER THE UPPER LOW WITH SOME
CONVECTIVE CLOUD DEVELOPMENT APPARENT. SOME OF THIS ACTIVITY IS
ALREADY GENERATING LIGHTNING OVER IOWA AND NERN MO. LATEST SPC
MESOSCALE ANALYSIS INDICATES AN AREA OF LOW LEVEL INSTABILITY
CONSISTENT WITH THE CURRENT CONVECTIVE DEVELOPMENT AND THE SHORT
RANGE HIGH RES MODEL GUIDANCE INDICATES THAT THERE IS A CHANCE FOR
THUNDERSTORM ACTIVITY TO MAINTAIN INTO THE EVENING HOURS...MOSTLY
ACROSS NRN IL. ALSO...MORNING SOUNDINGS INDICATE STRONG VERTICAL
SHEAR FROM THE SFC THROUGH MID LEVELS...SO LOW-TOPPED SUPERCELL
DEVELOPMENT REMAIN A POSSIBILITY STRONG...DAMAGING WIND...ISOLATED
LARGE HAIL AND A FEW TORNADOES WILL REMAIN A POSSIBILITY INTO THE
EVENING.
ANOTHER CONCERN FOR THE EVENING AND INTO THE OVERNIGHT HOURS WILL BE
STRONG SYNOPTIC SCALE WINDS. AS THE MAIN SFC LOW QUICKLY LIFTS NEWD
FROM ERN IOWA THIS AFTERNOON TO LAKE SUPERIOR WHILE DEEPENING AT
LEAST 10MB BY ARND 06Z...STRONG PRESSURE RISES IN THE WAKE OF THE
LOW WILL HELP GENERATE STRONG SLWY-WLY WINDS WITH SUSTAINED SPEEDS
ARND 30 MPH AND GUSTS OF 40-50 MPH. THE PERIOD OF THE STRONGEST
WINDS WILL BE FROM ARND 03-09Z WHICH WILL BE THE PERIOD OF THE
STRONGEST PRESSURE RISES.
FOR THURSDAY...CONDITIONS WILL BE MUCH QUIETER AS HIGH PRESSURE
BUILDS ACROSS THE REGION. EVEN WITH A STRONG COLD FRONT EXPECTED TO
MOVE ACROSS THE REGION AS THE SFC LOW LIFTS TO THE
NORTHEAST...TEMPERATURES WILL REMAIN ABOVE SEASONABLE NORMAL LEVELS
WITH HIGHS RANGING FROM AROUND 40F OVER THE ROCKFORD AREA TO THE
UPPER 40S SOUTH OF A VALPARAISO TO PONTIAC LINE.
KREIN
&&
.LONG TERM...
THURSDAY NIGHT THROUGH WEDNESDAY...
259 PM...TWO STORM SYSTEMS TO AFFECT THE REGION...FIRST SATURDAY
INTO SATURDAY NIGHT WITH HEAVY RAIN POSSIBLE ESPECIALLY ACROSS THE
SOUTHERN CWA. SECOND STORM SYSTEM MONDAY INTO TUESDAY...WITH
UNCERTAINTY REGARDING TIMING AND PRECIP TYPE.
HIGH PRESSURE WILL BE MOVING ACROSS THE AREA THURSDAY NIGHT INTO
FRIDAY WITH DRY CONDITIONS EXPECTED THROUGH FRIDAY EVENING. LIGHT
WINDS AND AT LEAST SOME PARTIAL CLEARING THURSDAY NIGHT SHOULD
ALLOW TEMPS TO DROP INTO THE UPPER 20S/LOWER 30S. HIGHS BACK IN
THE 40S ON CHRISTMAS DAY WITH INCREASING CLOUDS BY AFTERNOON/
EVENING AHEAD OF THE NEXT SYSTEM.
NEXT STORM SYSTEM BEGINS TO AFFECT THE AREA LATE FRIDAY NIGHT BUT
MORESO INTO SATURDAY WITH A COLD FRONT SLOWLY SAGGING THROUGH THE
AREA AND EVENTUALLY SOUTH OF THE AREA SATURDAY NIGHT. HOW FAST THIS
BOUNDARY SAGS SOUTH...OR ANY OTHER CHANGES TO ITS SPEED/LOCATION MAY
HAVE LARGE IMPACTS ON WHERE A BAND/CORRIDOR OF VERY HEAVY RAIN SETS
UP. CURRENTLY APPEARS TO BE ACROSS CENTRAL ILLINOIS INTO CENTRAL
INDIANA...INCLUDING THE FAR SOUTHEAST CWA. ITS POSSIBLE 1 TO 2
INCHES OF RAIN MAY FALL ACROSS THIS AREA THROUGH SATURDAY NIGHT
WITH AMOUNTS DECREASING ACROSS NORTHERN IL. THIS ADDITIONAL
RAINFALL MAY BOTH EXTEND CURRENT ELEVATED RIVER LEVELS AND CAUSE
POSSIBLE NEW RISES. THERMALLY...WHILE SURFACE WINDS SHIFT
NORTHERLY AND COOLER AIR SPREADS ACROSS THE REGION...IT APPEARS
THE BULK OF THIS PRECIP WILL FALL AS RAIN. HOWEVER...BY SUNDAY
MORNING...DEPENDING ON HOW MUCH PRECIP IS STILL OCCURRING...THERE
COULD BE A MIX WITH LIGHT SNOW. THOUGH PRECIP MAY END BEFORE IT
BECOMES COLD ENOUGH FOR A MIX WITH SNOW.
MAINTAINED LOW CHANCE POPS SUNDAY NIGHT BUT THIS TIME PERIOD IS ALSO
NOW LOOKING TO BE MAINLY DRY...WITH PERHAPS THE BEST CHANCE OF ANY
PRECIP ACROSS THE FAR SOUTHERN CWA AND TOWARD MONDAY MORNING. IF ANY
PRECIP DOES OCCUR SUNDAY NIGHT...THERE COULD BE SOME MIX OF SNOW OR
SLEET. WHILE THERE IS FAIR CONSISTENCY WITH PRECIP SPREADING BACK
ACROSS THE AREA MONDAY AND THEN PRECIP LIKELY MONDAY NIGHT...THE
TRACK OF THE LOW AND THUS THE EXTENT OF WARM AIR AND THEREFORE
PRECIP TYPE BECOMES QUITE UNCERTAIN. THE GEM/GFS ARE SIMILAR AND
COLDER WHILE THE ECMWF IS WARMER. A BLEND OF THESE SOLUTIONS IS IN
FAIR AGREEMENT WITH THE PREVIOUS FORECAST WHICH MAINTAINS A MIX OF
RAIN AND SNOW MONDAY AND MONDAY NIGHT. THERE IS SOME POTENTIAL FOR
SLEET AND PERHAPS FREEZING RAIN BUT GIVEN THE THERMAL
UNCERTAINTY... ITS TOO EARLY FOR DETAILS. HOWEVER...IF STRONG
PERSISTENT NORTHEAST WINDS DO DEVELOP...THIS WILL MAINTAIN A
DRIER...COOLER INFLOW AND ONCE PRECIP STARTS...EVAPORATIVE COOLING
MAY BE SUFFICIENT FOR AT LEAST A WINTERY MIX AND PERHAPS A PERIOD
OF SNOW. SMALL CHANGES IN THE TRACK WILL RESULT IN LARGE CHANGES
TO THE FORECAST.
COLDER AIR THEN APPEARS TO SPREAD BACK ACROSS THE AREA BY MID WEEK
NEXT WEEK WITH A WEAK DISTURBANCE THAT WILL LIKELY RESULT IN AT
LEAST A CHANCE OF LIGHT SNOW OR SNOW SHOWERS. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* POTENTIAL FOR A FEW ADDITIONAL STRONG STORMS EARLY THIS EVENING
(01-03 UTC).
* STRONG GUSTY SOUTH WINDS 25-30 KT THIS AFTERNOON.
* POTENTIAL FOR VERY STRONG SOUTHWESTERLY WINDS FOR A SHORT PERIOD
THIS EVENING BETWEEN 03-06 UTC. GUSTS OF 45 TO 50 KT POSSIBLE
DURING THIS PERIOD.
KJB/RATZER
//DISCUSSION...UPDATED 18Z...
A SIGNIFICANT STORM SYSTEM WILL CONTINUE TO IMPACT THE REGION INTO
TONIGHT. THE MAIN AVIATION WEATHER CONCERNS WILL BE THE POTENTIAL
FOR ADDITIONAL SCT STRONG THUNDERSTORMS EARLY THIS EVENING...GUSTY
SOUTH WINDS THIS AFTERNOON...FOLLOWED BY A PERIOD OF VERY STRONG
GUSTY SYNOPTIC SOUTHWESTERLY WINDS LATER THIS EVENING.
CURRENTLY AN AREA OF MAINLY SHOWERS...WITH A FEW EMBEDDED
THUNDERSTORMS...CONTINUES TO MOVE ACROSS THE EASTERN AIRFIELDS AS A
WARM FRONT GRADUALLY SHIFTS NORTHWARD OVER THE AREA. THIS SHOWERS
ACTIVITY WILL BEGIN TO MOVE OUT OF THE AREA AROUND...OR SLIGHTLY
AFTER THE 19 UTC HOUR...WITH ONLY SOME WIDELY SCT SHOWERS POSSIBLE
THEREAFTER. CIGS AND VSBYS WILL ALSO BE IMPROVING THIS
AFTERNOON...THOUGH THE SURFACE WINDS WILL CONTINUE TO BECOME DUE
SOUTHERLY AND GUSTY...UP AROUND 30 KT THROUGH THE REST OF THE
AFTERNOON.
ANOTHER BATCH OF SCATTERED THUNDERSTORMS MAY DEVELOP VERY LATE THIS
AFTERNOON OVER WESTERN ILLINOIS AHEAD OF AN APPROACHING COLD FRONT.
THESE STORMS COULD THEN PROGRESS EAST-NORTHEASTWARD OVER THE EASTERN
TERMINALS EARLY THIS EVENING...ROUGHLY BETWEEN 00 AND 03 UTC THIS
EVENING. THE POTENTIAL FOR STORMS AT A GIVEN TERMINAL WILL LIKELY BE
FAIRLY SHORT (UNDER AN HOUR)...THOUGH EXACT TIMING REQUIRES A 2 HOUR
TEMPO AT THIS RANGE. THESE POTENTIAL STORMS ALSO HAVE A CONDITIONAL
RISK OF BEING SEVERE WITH STRONG SURFACE WINDS.
FOLLOWING THE COLD FRONTAL PASSAGE...AROUND 02-03 UTC THIS
EVENING...IT APPEARS THAT THE SURFACE WINDS OUTSIDE OF THUNDERSTORMS
COULD BECOME VERY STRONG FOR A SHORT PERIOD. VERY STRONG PRESSURE
RISES LOOK TO OVERSPREAD THE AREA BEHIND THIS FRONT...AND THIS COULD
LEAD TO VERY EFFICIENT TRANSPORT OF STRONGER WINDS ALOFT TO THE
SURFACE MID TO LATE THIS EVENING. WIND GUSTS COULD BRIEFLY GUST IN
THE 45 TO 50 KT RANGE DURING THIS PERIOD...BEFORE ABATING
OVERNIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH WITH TSRA/TIMING THIS EVENING.
* MEDIUM HIGH WITH WIND FORECAST.
KJB/RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR.
SATURDAY...SHOWERS. CHANCE OF MVFR/IFR.
SUNDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
413 PM...DEEP LOW PRESSURE OVER EASTERN IOWA WILL MOVE NORTH
ACROSS LAKE SUPERIOR TONIGHT REACHING JAMES BAY THURSDAY. THIS LOW
WILL CONTINUE TO DEEPEN AND COMBINED WITH STRONG PRESSURE RISES
AND COLD AIR...VERY STRONG WINDS WILL DEVELOP THIS EVENING WITH
STORM FORCE WINDS LIKELY. THESE ARE EXPECTED TO DROP BACK TO GALES
BY MORNING WITH GALE FORCE WINDS STEADILY DIMINISHING THURSDAY
MORNING FROM SOUTH TO NORTH ACROSS THE LAKE. HIGH PRESSURE WILL
MOVE ACROSS THE LAKES REGION FRIDAY AND FRIDAY NIGHT. STRONG HIGH
PRESSURE WILL THEN MOVE ACROSS SOUTHERN CANADA AND THE NORTHERN
PLAINS THIS WEEKEND AS WEAK LOW PRESSURE MOVES ACROSS THE OHIO
VALLEY. THIS WILL STRENGTHEN A NORTHEAST GRADIENT ACROSS THE
REGION WITH SPEEDS INCREASING TO 30 KTS SUNDAY NIGHT INTO MONDAY
WITH GALES POSSIBLE MONDAY NIGHT ON THE SOUTH END OF THE LAKE. CMS
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 3 AM THURSDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 3 AM
THURSDAY.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779 UNTIL 9 PM WEDNESDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...3 AM
THURSDAY TO 6 AM THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...9 PM WEDNESDAY TO 3 AM THURSDAY.
DENSE FOG ADVISORY...LMZ777-LMZ779 UNTIL 6 PM WEDNESDAY.
GALE WARNING...LMZ777-LMZ779...3 AM THURSDAY TO 9 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
405 PM CST WED DEC 23 2015
.MESOSCALE DISCUSSION...
242 PM CST
FIRST ROUND OF THUNDERSTORMS HAS PUSHED OFF TO THE EAST WITH
STRATIFORM RAIN IN PLACE ACROSS PORTIONS OF EAST CENTRAL ILLINOIS
AND NORTHWEST INDIANA. LOW PRESSURE IS ANALYZED JUST SOUTH OF
KDSM THIS AFTERNOON WITH A FRONTAL BOUNDARY STRETCHING SOUTH
ACROSS MISSOURI. VISIBLE SATELLITE IMAGERY SHOWS TOWERING CU AND A
FEW CB/S IMMEDIATELY AHEAD OF THE FRONT WHERE SURFACE TEMPS ARE IN
THE MID 60S AND DEWPOINTS IN THE LOW TO MID 50S. 18Z SPECIAL
SOUNDING OUT OF KDVN SHOWED AROUND 250 J/KG SBCAPE WITH FAIRLY
INTENSE DEEP LAYER SHEAR IN EXCESS OF 70KT. WATER VAPOR IMAGERY
SHOWS A DRY SLOT WRAPPING INTO NORTHEASTERN MISSOURI AND
SOUTHEASTERN COINCIDENT WITH THE CORRIDOR OF MODEST INSTABILITY OF
200-600 J/KG MLCAPE WHICH RAP GUIDANCE SHOWS LIFTING ACROSS
PORTIONS OF NORTH CENTRAL ILLINOIS WITHIN THE NEXT FEW HOURS.
STRONG PRESSURE FALLS AHEAD OF THE LOW MAY HELP TO KEEP WINDS
BACKED ACROSS NORTH CENTRAL ILLINOIS WHICH WILL LOCALLY ENHANCE
THE THREAT FOR SUPERCELLS ALONG WITH THE POSSIBILITY OF AN
ISOLATED TORNADO. A BIT HARD TO TELL HOW FAR EAST THE SEVERE
THREAT WILL EXTEND THIS AFTERNOON AND EVENING...THOUGH HI- RES
MODELS HAVE CONSISTENTLY SHOWED A WEAKENING TREND AS THUNDERSTORMS
APPROACH THE CHICAGO METRO AREA THIS EVENING. FOR NOW AM MOST
CONCERNED ABOUT SEVERE WEATHER WEST OF A PONTIAC TO WOODSTOCK
LINE...BUT CERTAINLY NOT OUT OF THE WOODS FARTHER EAST.
DEUBELBEISS
&&
.SHORT TERM...
236 PM CST
THROUGH THURSDAY...
A DEEP UPPER TROUGH IS OVER THE CENTRAL CONUS WITH A STRONG MID
LEVEL SHORTWAVE TRACKING NEWD THROUGH THE UPPER MISSOURI VALLEY. A
SERIES OF WEAKER SHORTWAVES HAVE BEEN TRACKING NEWD THROUGH THE
MIDDLE MISSISSIPPI VALLEY...GENERATING SCT STRONG THUNDERSTORMS AS
FAR NORTH AS NERN IL AND NWRN IN EARLIER TODAY. THE SRN STREAM
SHORTWAVE ENERGY IS BEGINNING TO FOCUS TSRA OVER THE LOWER OHIO
VALLEY AND INTO INDIANA THIS AFTERNOON AND THE MAIN AREA OF CONCERN
WITH RESPECT TO TSRA ACTIVITY FOR THE LOCAL AREA WILL BE UNDER THE
MID LEVEL CIRCULATION CENTER. UNDER THE COLD CORE UPPER LOW AND
WITH UNSEASONABLY WARM...MOIST AIR IN PLACE OVER THE REGION...STRONG
LAPSE RATES AND MODEST LOW LEVEL INSTABILITY WILL KEEP A CHANCE FOR
THUNDERSTORMS INTO THE EVENING HOURS. THE LATEST SATELLITE IMAGERY
SHOWS SOME BREAKS IN THE OVERCAST UNDER THE UPPER LOW WITH SOME
CONVECTIVE CLOUD DEVELOPMENT APPARENT. SOME OF THIS ACTIVITY IS
ALREADY GENERATING LIGHTNING OVER IOWA AND NERN MO. LATEST SPC
MESOSCALE ANALYSIS INDICATES AN AREA OF LOW LEVEL INSTABILITY
CONSISTENT WITH THE CURRENT CONVECTIVE DEVELOPMENT AND THE SHORT
RANGE HIGH RES MODEL GUIDANCE INDICATES THAT THERE IS A CHANCE FOR
THUNDERSTORM ACTIVITY TO MAINTAIN INTO THE EVENING HOURS...MOSTLY
ACROSS NRN IL. ALSO...MORNING SOUNDINGS INDICATE STRONG VERTICAL
SHEAR FROM THE SFC THROUGH MID LEVELS...SO LOW-TOPPED SUPERCELL
DEVELOPMENT REMAIN A POSSIBILITY STRONG...DAMAGING WIND...ISOLATED
LARGE HAIL AND A FEW TORNADOES WILL REMAIN A POSSIBILITY INTO THE
EVENING.
ANOTHER CONCERN FOR THE EVENING AND INTO THE OVERNIGHT HOURS WILL BE
STRONG SYNOPTIC SCALE WINDS. AS THE MAIN SFC LOW QUICKLY LIFTS NEWD
FROM ERN IOWA THIS AFTERNOON TO LAKE SUPERIOR WHILE DEEPENING AT
LEAST 10MB BY ARND 06Z...STRONG PRESSURE RISES IN THE WAKE OF THE
LOW WILL HELP GENERATE STRONG SLWY-WLY WINDS WITH SUSTAINED SPEEDS
ARND 30 MPH AND GUSTS OF 40-50 MPH. THE PERIOD OF THE STRONGEST
WINDS WILL BE FROM ARND 03-09Z WHICH WILL BE THE PERIOD OF THE
STRONGEST PRESSURE RISES.
FOR THURSDAY...CONDITIONS WILL BE MUCH QUIETER AS HIGH PRESSURE
BUILDS ACROSS THE REGION. EVEN WITH A STRONG COLD FRONT EXPECTED TO
MOVE ACROSS THE REGION AS THE SFC LOW LIFTS TO THE
NORTHEAST...TEMPERATURES WILL REMAIN ABOVE SEASONABLE NORMAL LEVELS
WITH HIGHS RANGING FROM AROUND 40F OVER THE ROCKFORD AREA TO THE
UPPER 40S SOUTH OF A VALPARAISO TO PONTIAC LINE.
KREIN
&&
.LONG TERM...
THURSDAY NIGHT THROUGH WEDNESDAY...
259 PM...TWO STORM SYSTEMS TO AFFECT THE REGION...FIRST SATURDAY
INTO SATURDAY NIGHT WITH HEAVY RAIN POSSIBLE ESPECIALLY ACROSS THE
SOUTHERN CWA. SECOND STORM SYSTEM MONDAY INTO TUESDAY...WITH
UNCERTAINTY REGARDING TIMING AND PRECIP TYPE.
HIGH PRESSURE WILL BE MOVING ACROSS THE AREA THURSDAY NIGHT INTO
FRIDAY WITH DRY CONDITIONS EXPECTED THROUGH FRIDAY EVENING. LIGHT
WINDS AND AT LEAST SOME PARTIAL CLEARING THURSDAY NIGHT SHOULD
ALLOW TEMPS TO DROP INTO THE UPPER 20S/LOWER 30S. HIGHS BACK IN
THE 40S ON CHRISTMAS DAY WITH INCREASING CLOUDS BY AFTERNOON/
EVENING AHEAD OF THE NEXT SYSTEM.
NEXT STORM SYSTEM BEGINS TO AFFECT THE AREA LATE FRIDAY NIGHT BUT
MORESO INTO SATURDAY WITH A COLD FRONT SLOWLY SAGGING THROUGH THE
AREA AND EVENTUALLY SOUTH OF THE AREA SATURDAY NIGHT. HOW FAST THIS
BOUNDARY SAGS SOUTH...OR ANY OTHER CHANGES TO ITS SPEED/LOCATION MAY
HAVE LARGE IMPACTS ON WHERE A BAND/CORRIDOR OF VERY HEAVY RAIN SETS
UP. CURRENTLY APPEARS TO BE ACROSS CENTRAL ILLINOIS INTO CENTRAL
INDIANA...INCLUDING THE FAR SOUTHEAST CWA. ITS POSSIBLE 1 TO 2
INCHES OF RAIN MAY FALL ACROSS THIS AREA THROUGH SATURDAY NIGHT
WITH AMOUNTS DECREASING ACROSS NORTHERN IL. THIS ADDITIONAL
RAINFALL MAY BOTH EXTEND CURRENT ELEVATED RIVER LEVELS AND CAUSE
POSSIBLE NEW RISES. THERMALLY...WHILE SURFACE WINDS SHIFT
NORTHERLY AND COOLER AIR SPREADS ACROSS THE REGION...IT APPEARS
THE BULK OF THIS PRECIP WILL FALL AS RAIN. HOWEVER...BY SUNDAY
MORNING...DEPENDING ON HOW MUCH PRECIP IS STILL OCCURRING...THERE
COULD BE A MIX WITH LIGHT SNOW. THOUGH PRECIP MAY END BEFORE IT
BECOMES COLD ENOUGH FOR A MIX WITH SNOW.
MAINTAINED LOW CHANCE POPS SUNDAY NIGHT BUT THIS TIME PERIOD IS ALSO
NOW LOOKING TO BE MAINLY DRY...WITH PERHAPS THE BEST CHANCE OF ANY
PRECIP ACROSS THE FAR SOUTHERN CWA AND TOWARD MONDAY MORNING. IF ANY
PRECIP DOES OCCUR SUNDAY NIGHT...THERE COULD BE SOME MIX OF SNOW OR
SLEET. WHILE THERE IS FAIR CONSISTENCY WITH PRECIP SPREADING BACK
ACROSS THE AREA MONDAY AND THEN PRECIP LIKELY MONDAY NIGHT...THE
TRACK OF THE LOW AND THUS THE EXTENT OF WARM AIR AND THEREFORE
PRECIP TYPE BECOMES QUITE UNCERTAIN. THE GEM/GFS ARE SIMILAR AND
COLDER WHILE THE ECMWF IS WARMER. A BLEND OF THESE SOLUTIONS IS IN
FAIR AGREEMENT WITH THE PREVIOUS FORECAST WHICH MAINTAINS A MIX OF
RAIN AND SNOW MONDAY AND MONDAY NIGHT. THERE IS SOME POTENTIAL FOR
SLEET AND PERHAPS FREEZING RAIN BUT GIVEN THE THERMAL
UNCERTAINTY... ITS TOO EARLY FOR DETAILS. HOWEVER...IF STRONG
PERSISTENT NORTHEAST WINDS DO DEVELOP...THIS WILL MAINTAIN A
DRIER...COOLER INFLOW AND ONCE PRECIP STARTS...EVAPORATIVE COOLING
MAY BE SUFFICIENT FOR AT LEAST A WINTERY MIX AND PERHAPS A PERIOD
OF SNOW. SMALL CHANGES IN THE TRACK WILL RESULT IN LARGE CHANGES
TO THE FORECAST.
COLDER AIR THEN APPEARS TO SPREAD BACK ACROSS THE AREA BY MID WEEK
NEXT WEEK WITH A WEAK DISTURBANCE THAT WILL LIKELY RESULT IN AT
LEAST A CHANCE OF LIGHT SNOW OR SNOW SHOWERS. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* POTENTIAL FOR A FEW ADDITIONAL STRONG STORMS EARLY THIS EVENING
(01-03 UTC).
* STRONG GUSTY SOUTH WINDS 25-30 KT THIS AFTERNOON.
* POTENTIAL FOR VERY STRONG SOUTHWESTERLY WINDS FOR A SHORT PERIOD
THIS EVENING BETWEEN 03-06 UTC. GUSTS OF 45 TO 50 KT POSSIBLE
DURING THIS PERIOD.
KJB/RATZER
//DISCUSSION...UPDATED 18Z...
A SIGNIFICANT STORM SYSTEM WILL CONTINUE TO IMPACT THE REGION INTO
TONIGHT. THE MAIN AVIATION WEATHER CONCERNS WILL BE THE POTENTIAL
FOR ADDITIONAL SCT STRONG THUNDERSTORMS EARLY THIS EVENING...GUSTY
SOUTH WINDS THIS AFTERNOON...FOLLOWED BY A PERIOD OF VERY STRONG
GUSTY SYNOPTIC SOUTHWESTERLY WINDS LATER THIS EVENING.
CURRENTLY AN AREA OF MAINLY SHOWERS...WITH A FEW EMBEDDED
THUNDERSTORMS...CONTINUES TO MOVE ACROSS THE EASTERN AIRFIELDS AS A
WARM FRONT GRADUALLY SHIFTS NORTHWARD OVER THE AREA. THIS SHOWERS
ACTIVITY WILL BEGIN TO MOVE OUT OF THE AREA AROUND...OR SLIGHTLY
AFTER THE 19 UTC HOUR...WITH ONLY SOME WIDELY SCT SHOWERS POSSIBLE
THEREAFTER. CIGS AND VSBYS WILL ALSO BE IMPROVING THIS
AFTERNOON...THOUGH THE SURFACE WINDS WILL CONTINUE TO BECOME DUE
SOUTHERLY AND GUSTY...UP AROUND 30 KT THROUGH THE REST OF THE
AFTERNOON.
ANOTHER BATCH OF SCATTERED THUNDERSTORMS MAY DEVELOP VERY LATE THIS
AFTERNOON OVER WESTERN ILLINOIS AHEAD OF AN APPROACHING COLD FRONT.
THESE STORMS COULD THEN PROGRESS EAST-NORTHEASTWARD OVER THE EASTERN
TERMINALS EARLY THIS EVENING...ROUGHLY BETWEEN 00 AND 03 UTC THIS
EVENING. THE POTENTIAL FOR STORMS AT A GIVEN TERMINAL WILL LIKELY BE
FAIRLY SHORT (UNDER AN HOUR)...THOUGH EXACT TIMING REQUIRES A 2 HOUR
TEMPO AT THIS RANGE. THESE POTENTIAL STORMS ALSO HAVE A CONDITIONAL
RISK OF BEING SEVERE WITH STRONG SURFACE WINDS.
FOLLOWING THE COLD FRONTAL PASSAGE...AROUND 02-03 UTC THIS
EVENING...IT APPEARS THAT THE SURFACE WINDS OUTSIDE OF THUNDERSTORMS
COULD BECOME VERY STRONG FOR A SHORT PERIOD. VERY STRONG PRESSURE
RISES LOOK TO OVERSPREAD THE AREA BEHIND THIS FRONT...AND THIS COULD
LEAD TO VERY EFFICIENT TRANSPORT OF STRONGER WINDS ALOFT TO THE
SURFACE MID TO LATE THIS EVENING. WIND GUSTS COULD BRIEFLY GUST IN
THE 45 TO 50 KT RANGE DURING THIS PERIOD...BEFORE ABATING
OVERNIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM-HIGH WITH TSRA/TIMING THIS EVENING.
* MEDIUM HIGH WITH WIND FORECAST.
KJB/RATZER
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR.
SATURDAY...SHOWERS. CHANCE OF MVFR/IFR.
SUNDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
446 AM CST
SIGNIFICANT CHANGES MADE TO WINDS/WAVES FOR THIS FORECAST
PERIOD...WITH STORM FORCE WINDS AND GALES LIKELY ACROSS THE ENTIRE
LAKE LATER TODAY...TONIGHT...AND THURSDAY.
SOUTHEAST WINDS WILL CONTINUE TO INCREASE TODAY AS LOW PRESSURE OVER
THE CENTRAL PLAINS LIFTS NORTHEAST ACROSS THE REGION. EXPECT WINDS
TO REALLY RAMP UP THIS AFTERNOON...WITH TO 30KT WINDS BEING OBSERVED
ACROSS ALL OF THE LAKE. ALTHOUGH NOT OVERLY CONFIDENT...DO THINK
THERE WILL BE AT LEAST GALE FORCE GUSTS ACROSS THE NEARSHORE WATERS
AND SOUTH HALF OF THE LAKE THIS AFTERNOON...AND HAVE THAT INCLUDED
IN THE FORECAST. WINDS WILL FURTHER INCREASE TONIGHT WITH HIGH END
GALES TO 45 KT EXPECTED ACROSS THE SOUTH HALF AND NEARSHORE...AND
THEN STORM FORCE WINDS TO 50KT ACROSS THE NORTH HALF. THERE WILL
BE A POSSIBILITY FOR STORM FORCE WINDS ACROSS THE SOUTH HALF AND
NEARSHORE...BUT AT THIS TIME...THIS LOOKS TO BE ONLY FOR A SMALL
WINDOW. HOWEVER...WILL NEED TO MONITOR THE POTENTIAL FOR A LONGER
PERIOD OF POSSIBLE STORM FORCE WINDS IN THOSE LOCATIONS. WINDS
WILL BEGIN TO COME DOWN ON THURSDAY...BUT WITH STORM AND GALES
HOLDING ONTO A LITTLE LONGER ON THE NORTH HALF. HAVE GALES GOING
ACROSS THE NORTH INTO THE AFTERNOON...BUT THERE IS A POSSIBILITY
THAT THEY MAY CONTINUE EVEN INTO IN THE EVENING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039 UNTIL 3 AM THURSDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL 3 AM
THURSDAY.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779 UNTIL 9 PM WEDNESDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...3 AM
THURSDAY TO 6 AM THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...9 PM WEDNESDAY TO 3 AM THURSDAY.
DENSE FOG ADVISORY...LMZ777-LMZ779 UNTIL 6 PM WEDNESDAY.
GALE WARNING...LMZ777-LMZ779...3 AM THURSDAY TO 9 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
312 PM CST WED DEC 23 2015
.SHORT TERM...(Tonight)
ISSUED AT 312 PM CST WED DEC 23 2015
First round of severe weather has exited the eastern forecast area
early this afternoon, but storms have quickly started to fire in
northeast Missouri. This particular area has seen some sunshine
during the afternoon, helping to destabilize the atmosphere, where
CAPE`s are above 500 J/kg and 0-6km bulk shear is an impressive 60-
70 knots. HRRR latched onto this area of development earlier, and
races it across the northern part of the forecast area between 4 pm
and 8 pm. Have concentrated the highest PoP`s for the rest of the
afternoon in this area. The storms should be weakening after sunset
as the surface low pulls northeast, and there is some question about
how much the atmosphere across the eastern CWA can recover after
being thoroughly worked over the last several hours.
Secondary concern is with the winds this evening. Have issued a Wind
Advisory for the period from 6 pm to 2 am across about the northwest
half of the forecast area. Main surface low is currently located
across northeast Iowa, and will be zipping northeast. Impressive 3-
hour pressure rises of 10-11 mb are progged to track northeastward
to around Rockford by midnight. Wind gusts of 45 mph or so are
likely across the northwest half of the forecast area as this
bullseye passes. Have gone as far south as Jacksonville with the
advisory, but this area may be of a shorter duration. Most of the
winds should be diminishing around midnight, but will linger a bit
longer north of I-74.
&&
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 312 PM CST WED DEC 23 2015
Short and medium range models are in fairly good agreement with the
overall active weather pattern through the weekend and into early
next week. Unseasonably warm temperatures and very wet weather will
be the main factors for the weekend through late Monday.
In the shorter term, mild temperatures and periods of cloudiness can
be expected for Christmas Eve into much of Christmas Day. The return
of a surface boundary north of the Ohio Valley and associated weak
isentropic lift initially will result in a chance for light rain in
southeast IL late on Christmas Day. The GFS is the odd model out on
this one by keeping the boundary much farther south.
Backing upper level flow in response to a digging trough in the
western U.S. will allow very warm and moist air to return into much
of central and SE IL during the day Saturday. This feed of moisture
and the associated rainfall will linger in the forecast area through
most of Sunday, resulting in 2.50 to 3.50 inches of rain. The
precipitation area will gradually sag south as the upper low in the
west closes off in SW Texas and an upper level confluent area sets
up across central IL by later in the day Sunday.
The upper low in the southwestern U.S. is expected to kick out
toward the Midwest Monday as another strong upper level trough digs
from the Pacific NW to the southern Plains. This will bring the
likelihood of precipitation back to central IL for Monday. The
forecast type becomes a bit tricky north of a Rushville-Bloomington
line Monday into Monday night as upper level soundings indicate a
mix of rain/snow/sleet possible. Could be some minor accumulations
of snow NW of Peoria late Monday, but there is a lot of uncertainty
with this scenario 6 days out.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 1149 AM CST WED DEC 23 2015
Active convective weather with a complex weather system can be
expected in central and eastern IL this afternoon through this
evening. The majority of the area is in the warm sector of the
storm system, so ceilings have come up considerably due to this
and the high winds from the mixing of the lower atmosphere.
Several rounds of showers/t-storms will impact central and eastern
IL TAF sites through at least 20-21 UTC before the next round
approaches/develops in the 21-03 UTC timeframe. Added a TEMPO
group to not only highlight the MVFR visibility/ceilings from the
moderate to heavy rain, but also wind gusts exceeding 40 kts from
the strongest thunderstorms.
Outside of the thunderstorms, VFR conditions are anticipated.
However, an increasing pressure gradient this afternoon through
the evening will result in south to southwest winds of 25-30 kts
with gusts around 35 kts.
The sky is expected to partially clear and wind settle down a bit
after midnight local time. Increasing mid level clouds are
anticipated by mid-morning Thursday, but conditions will be VFR.
&&
.ILX Watches/Warnings/Advisories...
Wind Advisory until 2 AM CST Thursday for ILZ027>031-036>038-
040>043-047>050.
&&
$$
SHORT TERM...Geelhart
LONG TERM...Miller
AVIATION...Miller
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
259 PM CST WED DEC 23 2015
.MESOSCALE DISCUSSION...
242 PM CST
FIRST ROUND OF THUNDERSTORMS HAS PUSHED OFF TO THE EAST WITH
STRATIFORM RAIN IN PLACE ACROSS PORTIONS OF EAST CENTRAL ILLINOIS
AND NORTHWEST INDIANA. LOW PRESSURE IS ANALYZED JUST SOUTH OF
KDSM THIS AFTERNOON WITH A FRONTAL BOUNDARY STRETCHING SOUTH
ACROSS MISSOURI. VISIBLE SATELLITE IMAGERY SHOWS TOWERING CU AND A
FEW CB/S IMMEDIATELY AHEAD OF THE FRONT WHERE SURFACE TEMPS ARE IN
THE MID 60S AND DEWPOINTS IN THE LOW TO MID 50S. 18Z SPECIAL
SOUNDING OUT OF KDVN SHOWED AROUND 250 J/KG SBCAPE WITH FAIRLY
INTENSE DEEP LAYER SHEAR IN EXCESS OF 70KT. WATER VAPOR IMAGERY
SHOWS A DRY SLOT WRAPPING INTO NORTHEASTERN MISSOURI AND
SOUTHEASTERN COINCIDENT WITH THE CORRIDOR OF MODEST INSTABILITY OF
200-600 J/KG MLCAPE WHICH RAP GUIDANCE SHOWS LIFTING ACROSS
PORTIONS OF NORTH CENTRAL ILLINOIS WITHIN THE NEXT FEW HOURS.
STRONG PRESSURE FALLS AHEAD OF THE LOW MAY HELP TO KEEP WINDS
BACKED ACROSS NORTH CENTRAL ILLINOIS WHICH WILL LOCALLY ENHANCE
THE THREAT FOR SUPERCELLS ALONG WITH THE POSSIBILITY OF AN
ISOLATED TORNADO. A BIT HARD TO TELL HOW FAR EAST THE SEVERE
THREAT WILL EXTEND THIS AFTERNOON AND EVENING...THOUGH HI- RES
MODELS HAVE CONSISTENTLY SHOWED A WEAKENING TREND AS THUNDERSTORMS
APPROACH THE CHICAGO METRO AREA THIS EVENING. FOR NOW AM MOST
CONCERNED ABOUT SEVERE WEATHER WEST OF A PONTIAC TO WOODSTOCK
LINE...BUT CERTAINLY NOT OUT OF THE WOODS FARTHER EAST.
DEUBELBEISS
&&
.SHORT TERM...
236 PM CST
THROUGH THURSDAY...
A DEEP UPPER TROUGH IS OVER THE CENTRAL CONUS WITH A STRONG MID
LEVEL SHORTWAVE TRACKING NEWD THROUGH THE UPPER MISSOURI VALLEY. A
SERIES OF WEAKER SHORTWAVES HAVE BEEN TRACKING NEWD THROUGH THE
MIDDLE MISSISSIPPI VALLEY...GENERATING SCT STRONG THUNDERSTORMS AS
FAR NORTH AS NERN IL AND NWRN IN EARLIER TODAY. THE SRN STREAM
SHORTWAVE ENERGY IS BEGINNING TO FOCUS TSRA OVER THE LOWER OHIO
VALLEY AND INTO INDIANA THIS AFTERNOON AND THE MAIN AREA OF CONCERN
WITH RESPECT TO TSRA ACTIVITY FOR THE LOCAL AREA WILL BE UNDER THE
MID LEVEL CIRCULATION CENTER. UNDER THE COLD CORE UPPER LOW AND
WITH UNSEASONABLY WARM...MOIST AIR IN PLACE OVER THE REGION...STRONG
LAPSE RATES AND MODEST LOW LEVEL INSTABILITY WILL KEEP A CHANCE FOR
THUNDERSTORMS INTO THE EVENING HOURS. THE LATEST SATELLITE IMAGERY
SHOWS SOME BREAKS IN THE OVERCAST UNDER THE UPPER LOW WITH SOME
CONVECTIVE CLOUD DEVELOPMENT APPARENT. SOME OF THIS ACTIVITY IS
ALREADY GENERATING LIGHTNING OVER IOWA AND NERN MO. LATEST SPC
MESOSCALE ANALYSIS INDICATES AN AREA OF LOW LEVEL INSTABILITY
CONSISTENT WITH THE CURRENT CONVECTIVE DEVELOPMENT AND THE SHORT
RANGE HIGH RES MODEL GUIDANCE INDICATES THAT THERE IS A CHANCE FOR
THUNDERSTORM ACTIVITY TO MAINTAIN INTO THE EVENING HOURS...MOSTLY
ACROSS NRN IL. ALSO...MORNING SOUNDINGS INDICATE STRONG VERTICAL
SHEAR FROM THE SFC THROUGH MID LEVELS...SO LOW-TOPPED SUPERCELL
DEVELOPMENT REMAIN A POSSIBILITY STRONG...DAMAGING WIND...ISOLATED
LARGE HAIL AND A FEW TORNADOES WILL REMAIN A POSSIBILITY INTO THE
EVENING.
ANOTHER CONCERN FOR THE EVENING AND INTO THE OVERNIGHT HOURS WILL BE
STRONG SYNOPTIC SCALE WINDS. AS THE MAIN SFC LOW QUICKLY LIFTS NEWD
FROM ERN IOWA THIS AFTERNOON TO LAKE SUPERIOR WHILE DEEPENING AT
LEAST 10MB BY ARND 06Z...STRONG PRESSURE RISES IN THE WAKE OF THE
LOW WILL HELP GENERATE STRONG SLWY-WLY WINDS WITH SUSTAINED SPEEDS
ARND 30 MPH AND GUSTS OF 40-50 MPH. THE PERIOD OF THE STRONGEST
WINDS WILL BE FROM ARND 03-09Z WHICH WILL BE THE PERIOD OF THE
STRONGEST PRESSURE RISES.
FOR THURSDAY...CONDITIONS WILL BE MUCH QUIETER AS HIGH PRESSURE
BUILDS ACROSS THE REGION. EVEN WITH A STRONG COLD FRONT EXPECTED TO
MOVE ACROSS THE REGION AS THE SFC LOW LIFTS TO THE
NORTHEAST...TEMPERATURES WILL REMAIN ABOVE SEASONABLE NORMAL LEVELS
WITH HIGHS RANGING FROM AROUND 40F OVER THE ROCKFORD AREA TO THE
UPPER 40S SOUTH OF A VALPARAISO TO PONTIAC LINE.
KREIN
&&
.LONG TERM...
THURSDAY NIGHT THROUGH WEDNESDAY...
259 PM...TWO STORM SYSTEMS TO AFFECT THE REGION...FIRST SATURDAY
INTO SATURDAY NIGHT WITH HEAVY RAIN POSSIBLE ESPECIALLY ACROSS THE
SOUTHERN CWA. SECOND STORM SYSTEM MONDAY INTO TUESDAY...WITH
UNCERTAINTY REGARDING TIMING AND PRECIP TYPE.
HIGH PRESSURE WILL BE MOVING ACROSS THE AREA THURSDAY NIGHT INTO
FRIDAY WITH DRY CONDITIONS EXPECTED THROUGH FRIDAY EVENING. LIGHT
WINDS AND AT LEAST SOME PARTIAL CLEARING THURSDAY NIGHT SHOULD
ALLOW TEMPS TO DROP INTO THE UPPER 20S/LOWER 30S. HIGHS BACK IN
THE 40S ON CHRISTMAS DAY WITH INCREASING CLOUDS BY AFTERNOON/
EVENING AHEAD OF THE NEXT SYSTEM.
NEXT STORM SYSTEM BEGINS TO AFFECT THE AREA LATE FRIDAY NIGHT BUT
MORESO INTO SATURDAY WITH A COLD FRONT SLOWLY SAGGING THROUGH THE
AREA AND EVENTUALLY SOUTH OF THE AREA SATURDAY NIGHT. HOW FAST THIS
BOUNDARY SAGS SOUTH...OR ANY OTHER CHANGES TO ITS SPEED/LOCATION MAY
HAVE LARGE IMPACTS ON WHERE A BAND/CORRIDOR OF VERY HEAVY RAIN SETS
UP. CURRENTLY APPEARS TO BE ACROSS CENTRAL ILLINOIS INTO CENTRAL
INDIANA...INCLUDING THE FAR SOUTHEAST CWA. ITS POSSIBLE 1 TO 2
INCHES OF RAIN MAY FALL ACROSS THIS AREA THROUGH SATURDAY NIGHT
WITH AMOUNTS DECREASING ACROSS NORTHERN IL. THIS ADDITIONAL
RAINFALL MAY BOTH EXTEND CURRENT ELEVATED RIVER LEVELS AND CAUSE
POSSIBLE NEW RISES. THERMALLY...WHILE SURFACE WINDS SHIFT
NORTHERLY AND COOLER AIR SPREADS ACROSS THE REGION...IT APPEARS
THE BULK OF THIS PRECIP WILL FALL AS RAIN. HOWEVER...BY SUNDAY
MORNING...DEPENDING ON HOW MUCH PRECIP IS STILL OCCURRING...THERE
COULD BE A MIX WITH LIGHT SNOW. THOUGH PRECIP MAY END BEFORE IT
BECOMES COLD ENOUGH FOR A MIX WITH SNOW.
MAINTAINED LOW CHANCE POPS SUNDAY NIGHT BUT THIS TIME PERIOD IS ALSO
NOW LOOKING TO BE MAINLY DRY...WITH PERHAPS THE BEST CHANCE OF ANY
PRECIP ACROSS THE FAR SOUTHERN CWA AND TOWARD MONDAY MORNING. IF ANY
PRECIP DOES OCCUR SUNDAY NIGHT...THERE COULD BE SOME MIX OF SNOW OR
SLEET. WHILE THERE IS FAIR CONSISTENCY WITH PRECIP SPREADING BACK
ACROSS THE AREA MONDAY AND THEN PRECIP LIKELY MONDAY NIGHT...THE
TRACK OF THE LOW AND THUS THE EXTENT OF WARM AIR AND THEREFORE
PRECIP TYPE BECOMES QUITE UNCERTAIN. THE GEM/GFS ARE SIMILAR AND
COLDER WHILE THE ECMWF IS WARMER. A BLEND OF THESE SOLUTIONS IS IN
FAIR AGREEMENT WITH THE PREVIOUS FORECAST WHICH MAINTAINS A MIX OF
RAIN AND SNOW MONDAY AND MONDAY NIGHT. THERE IS SOME POTENTIAL FOR
SLEET AND PERHAPS FREEZING RAIN BUT GIVEN THE THERMAL
UNCERTAINTY... ITS TOO EARLY FOR DETAILS. HOWEVER...IF STRONG
PERSISTENT NORTHEAST WINDS DO DEVELOP...THIS WILL MAINTAIN A
DRIER...COOLER INFLOW AND ONCE PRECIP STARTS...EVAPORATIVE COOLING
MAY BE SUFFICIENT FOR AT LEAST A WINTERY MIX AND PERHAPS A PERIOD
OF SNOW. SMALL CHANGES IN THE TRACK WILL RESULT IN LARGE CHANGES
TO THE FORECAST.
COLDER AIR THEN APPEARS TO SPREAD BACK ACROSS THE AREA BY MID WEEK
NEXT WEEK WITH A WEAK DISTURBANCE THAT WILL LIKELY RESULT IN AT
LEAST A CHANCE OF LIGHT SNOW OR SNOW SHOWERS. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* POTENTIAL FOR A FEW ADDITIONAL STRONG STORMS EARLY THIS EVENING
(01-03 UTC).
* INCREASING SOUTHERLY WINDS THIS AFTERNOON.
* POTENTIAL FOR VERY STRONG SOUTHWESTERLY WINDS FOR A SHORT PERIOD
THIS EVENING BETWEEN 03-06 UTC. GUSTS OF 45 TO 50 KT POSSIBLE
DURING THIS PERIOD.
KJB
//DISCUSSION...UPDATED 18Z...
A SIGNIFICANT STORM SYSTEM WILL CONTINUE TO IMPACT THE REGION INTO
TONIGHT. THE MAIN AVIATION WEATHER CONCERNS WILL BE THE POTENTIAL
FOR ADDITIONAL SCT STRONG THUNDERSTORMS EARLY THIS EVENING...GUSTY
SOUTH WINDS THIS AFTERNOON...FOLLOWED BY A PERIOD OF VERY STRONG
GUSTY SYNOPTIC SOUTHWESTERLY WINDS LATER THIS EVENING.
CURRENTLY AN AREA OF MAINLY SHOWERS...WITH A FEW EMBEDDED
THUNDERSTORMS...CONTINUES TO MOVE ACROSS THE EASTERN AIRFIELDS AS A
WARM FRONT GRADUALLY SHIFTS NORTHWARD OVER THE AREA. THIS SHOWERS
ACTIVITY WILL BEGIN TO MOVE OUT OF THE AREA AROUND...OR SLIGHTLY
AFTER THE 19 UTC HOUR...WITH ONLY SOME WIDELY SCT SHOWERS POSSIBLE
THEREAFTER. CIGS AND VSBYS WILL ALSO BE IMPROVING THIS
AFTERNOON...THOUGH THE SURFACE WINDS WILL CONTINUE TO BECOME DUE
SOUTHERLY AND GUSTY...UP AROUND 30 KT THROUGH THE REST OF THE
AFTERNOON.
ANOTHER BATCH OF SCATTERED THUNDERSTORMS MAY DEVELOP VERY LATE THIS
AFTERNOON OVER WESTERN ILLINOIS AHEAD OF AN APPROACHING COLD FRONT.
THESE STORMS COULD THEN PROGRESS EAST-NORTHEASTWARD OVER THE EASTERN
TERMINALS EARLY THIS EVENING...ROUGHLY BETWEEN 00 AND 03 UTC THIS
EVENING. THE POTENTIAL FOR STORMS AT A GIVEN TERMINAL WILL LIKELY BE
FAIRLY SHORT (UNDER AN HOUR)...THOUGH EXACT TIMING REQUIRES A 2 HOUR
TEMPO AT THIS RANGE. THESE POTENTIAL STORMS ALSO HAVE A CONDITIONAL
RISK OF BEING SEVERE WITH STRONG SURFACE WINDS.
FOLLOWING THE COLD FRONTAL PASSAGE...AROUND 02-03 UTC THIS
EVENING...IT APPEARS THAT THE SURFACE WINDS OUTSIDE OF THUNDERSTORMS
COULD BECOME VERY STRONG FOR A SHORT PERIOD. VERY STRONG PRESSURE
RISES LOOK TO OVERSPREAD THE AREA BEHIND THIS FRONT...AND THIS COULD
LEAD TO VERY EFFICIENT TRANSPORT OF STRONGER WINDS ALOFT TO THE
SURFACE MID TO LATE THIS EVENING. WIND GUSTS COULD BRIEFLY GUST IN
THE 45 TO 50 KT RANGE DURING THIS PERIOD...BEFORE ABATING
OVERNIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM WITH TSRA/TIMING THIS EVENING.
* MEDIUM HIGH WITH WIND FORECAST.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR.
SATURDAY...SHOWERS. CHANCE OF MVFR/IFR.
SUNDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
446 AM CST
SIGNIFICANT CHANGES MADE TO WINDS/WAVES FOR THIS FORECAST
PERIOD...WITH STORM FORCE WINDS AND GALES LIKELY ACROSS THE ENTIRE
LAKE LATER TODAY...TONIGHT...AND THURSDAY.
SOUTHEAST WINDS WILL CONTINUE TO INCREASE TODAY AS LOW PRESSURE OVER
THE CENTRAL PLAINS LIFTS NORTHEAST ACROSS THE REGION. EXPECT WINDS
TO REALLY RAMP UP THIS AFTERNOON...WITH TO 30KT WINDS BEING OBSERVED
ACROSS ALL OF THE LAKE. ALTHOUGH NOT OVERLY CONFIDENT...DO THINK
THERE WILL BE AT LEAST GALE FORCE GUSTS ACROSS THE NEARSHORE WATERS
AND SOUTH HALF OF THE LAKE THIS AFTERNOON...AND HAVE THAT INCLUDED
IN THE FORECAST. WINDS WILL FURTHER INCREASE TONIGHT WITH HIGH END
GALES TO 45 KT EXPECTED ACROSS THE SOUTH HALF AND NEARSHORE...AND
THEN STORM FORCE WINDS TO 50KT ACROSS THE NORTH HALF. THERE WILL
BE A POSSIBILITY FOR STORM FORCE WINDS ACROSS THE SOUTH HALF AND
NEARSHORE...BUT AT THIS TIME...THIS LOOKS TO BE ONLY FOR A SMALL
WINDOW. HOWEVER...WILL NEED TO MONITOR THE POTENTIAL FOR A LONGER
PERIOD OF POSSIBLE STORM FORCE WINDS IN THOSE LOCATIONS. WINDS
WILL BEGIN TO COME DOWN ON THURSDAY...BUT WITH STORM AND GALES
HOLDING ONTO A LITTLE LONGER ON THE NORTH HALF. HAVE GALES GOING
ACROSS THE NORTH INTO THE AFTERNOON...BUT THERE IS A POSSIBILITY
THAT THEY MAY CONTINUE EVEN INTO IN THE EVENING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039...6 PM WEDNESDAY TO 3 AM THURSDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...6 PM
WEDNESDAY TO 3 AM THURSDAY.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...6 PM WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...3 AM
THURSDAY TO 6 AM THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...9 PM WEDNESDAY TO 3 AM THURSDAY.
DENSE FOG ADVISORY...LMZ777-LMZ779 UNTIL 6 PM WEDNESDAY.
GALE WARNING...LMZ777-LMZ779...3 AM THURSDAY TO 9 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
242 PM CST WED DEC 23 2015
.MESOSCALE DISCUSSION...
242 PM CST
FIRST ROUND OF THUNDERSTORMS HAS PUSHED OFF TO THE EAST WITH
STRATIFORM RAIN IN PLACE ACROSS PORTIONS OF EAST CENTRAL ILLINOIS
AND NORTHWEST INDIANA. LOW PRESSURE IS ANALYZED JUST SOUTH OF
KDSM THIS AFTERNOON WITH A FRONTAL BOUNDARY STRETCHING SOUTH
ACROSS MISSOURI. VISIBLE SATELLITE IMAGERY SHOWS TOWERING CU AND A
FEW CB/S IMMEDIATELY AHEAD OF THE FRONT WHERE SURFACE TEMPS ARE IN
THE MID 60S AND DEWPOINTS IN THE LOW TO MID 50S. 18Z SPECIAL
SOUNDING OUT OF KDVN SHOWED AROUND 250 J/KG SBCAPE WITH FAIRLY
INTENSE DEEP LAYER SHEAR IN EXCESS OF 70KT. WATER VAPOR IMAGERY
SHOWS A DRY SLOT WRAPPING INTO NORTHEASTERN MISSOURI AND
SOUTHEASTERN COINCIDENT WITH THE CORRIDOR OF MODEST INSTABILITY OF
200-600 J/KG MLCAPE WHICH RAP GUIDANCE SHOWS LIFTING ACROSS
PORTIONS OF NORTH CENTRAL ILLINOIS WITHIN THE NEXT FEW HOURS.
STRONG PRESSURE FALLS AHEAD OF THE LOW MAY HELP TO KEEP WINDS
BACKED ACROSS NORTH CENTRAL ILLINOIS WHICH WILL LOCALLY ENHANCE
THE THREAT FOR SUPERCELLS ALONG WITH THE POSSIBILITY OF AN
ISOLATED TORNADO. A BIT HARD TO TELL HOW FAR EAST THE SEVERE
THREAT WILL EXTEND THIS AFTERNOON AND EVENING...THOUGH HI- RES
MODELS HAVE CONSISTENTLY SHOWED A WEAKENING TREND AS THUNDERSTORMS
APPROACH THE CHICAGO METRO AREA THIS EVENING. FOR NOW AM MOST
CONCERNED ABOUT SEVERE WEATHER WEST OF A PONTIAC TO WOODSTOCK
LINE...BUT CERTAINLY NOT OUT OF THE WOODS FARTHER EAST.
DEUBELBEISS
&&
.SHORT TERM...
236 PM CST
THROUGH THURSDAY...
A DEEP UPPER TROUGH IS OVER THE CENTRAL CONUS WITH A STRONG MID
LEVEL SHORTWAVE TRACKING NEWD THROUGH THE UPPER MISSOURI VALLEY. A
SERIES OF WEAKER SHORTWAVES HAVE BEEN TRACKING NEWD THROUGH THE
MIDDLE MISSISSIPPI VALLEY...GENERATING SCT STRONG THUNDERSTORMS AS
FAR NORTH AS NERN IL AND NWRN IN EARLIER TODAY. THE SRN STREAM
SHORTWAVE ENERGY IS BEGINNING TO FOCUS TSRA OVER THE LOWER OHIO
VALLEY AND INTO INDIANA THIS AFTERNOON AND THE MAIN AREA OF CONCERN
WITH RESPECT TO TSRA ACTIVITY FOR THE LOCAL AREA WILL BE UNDER THE
MID LEVEL CIRCULATION CENTER. UNDER THE COLD CORE UPPER LOW AND
WITH UNSEASONABLY WARM...MOIST AIR IN PLACE OVER THE REGION...STRONG
LAPSE RATES AND MODEST LOW LEVEL INSTABILITY WILL KEEP A CHANCE FOR
THUNDERSTORMS INTO THE EVENING HOURS. THE LATEST SATELLITE IMAGERY
SHOWS SOME BREAKS IN THE OVERCAST UNDER THE UPPER LOW WITH SOME
CONVECTIVE CLOUD DEVELOPMENT APPARENT. SOME OF THIS ACTIVITY IS
ALREADY GENERATING LIGHTNING OVER IOWA AND NERN MO. LATEST SPC
MESOSCALE ANALYSIS INDICATES AN AREA OF LOW LEVEL INSTABILITY
CONSISTENT WITH THE CURRENT CONVECTIVE DEVELOPMENT AND THE SHORT
RANGE HIGH RES MODEL GUIDANCE INDICATES THAT THERE IS A CHANCE FOR
THUNDERSTORM ACTIVITY TO MAINTAIN INTO THE EVENING HOURS...MOSTLY
ACROSS NRN IL. ALSO...MORNING SOUNDINGS INDICATE STRONG VERTICAL
SHEAR FROM THE SFC THROUGH MID LEVELS...SO LOW-TOPPED SUPERCELL
DEVELOPMENT REMAIN A POSSIBILITY STRONG...DAMAGING WIND...ISOLATED
LARGE HAIL AND A FEW TORNADOES WILL REMAIN A POSSIBILITY INTO THE
EVENING.
ANOTHER CONCERN FOR THE EVENING AND INTO THE OVERNIGHT HOURS WILL BE
STRONG SYNOPTIC SCALE WINDS. AS THE MAIN SFC LOW QUICKLY LIFTS NEWD
FROM ERN IOWA THIS AFTERNOON TO LAKE SUPERIOR WHILE DEEPENING AT
LEAST 10MB BY ARND 06Z...STRONG PRESSURE RISES IN THE WAKE OF THE
LOW WILL HELP GENERATE STRONG SLWY-WLY WINDS WITH SUSTAINED SPEEDS
ARND 30 MPH AND GUSTS OF 40-50 MPH. THE PERIOD OF THE STRONGEST
WINDS WILL BE FROM ARND 03-09Z WHICH WILL BE THE PERIOD OF THE
STRONGEST PRESSURE RISES.
FOR THURSDAY...CONDITIONS WILL BE MUCH QUIETER AS HIGH PRESSURE
BUILDS ACROSS THE REGION. EVEN WITH A STRONG COLD FRONT EXPECTED TO
MOVE ACROSS THE REGION AS THE SFC LOW LIFTS TO THE
NORTHEAST...TEMPERATURES WILL REMAIN ABOVE SEASONABLE NORMAL LEVELS
WITH HIGHS RANGING FROM AROUND 40F OVER THE ROCKFORD AREA TO THE
UPPER 40S SOUTH OF A VALPARAISO TO PONTIAC LINE.
KREIN
&&
.LONG TERM...
316 AM CST
THURSDAY THROUGH TUESDAY...
THURSDAY THROUGH FRIDAY...
ANTI-CYCLONIC FLOW QUICKLY ARRIVES EARLY THUR IN THE WAKE OF THE
DEPARTING TROUGH. THE 500MB PATTERN DOES BECOME QUASI-ZONAL FOR
THUR/FRI...WHICH WILL HELP TO KEEP TEMPS STILL SEVERAL DEGREES
ABOVE CLIMO IN THE LOW/MID 40S CHRISTMAS DAYAND POSSIBLY UPR 40S
FRI. DESPITE THE SFC RIDGE SLIDING OVERHEAD CHRISTMAS DAY...SKIES
WILL AT BEST BECOME P-CLOUDY IN THE AFTERNOON. THE DRY WEATHER
WILL ONLY BE SHORT-LIVED THROUGH FRI...AS THE ACTIVE PATTERN
BEGINS TO RAMP BACK-UP AS A TROUGH DIGS INTO THE FOUR- CORNERS
REGION OF THE CONUS. A QUASI-STATIONARY BOUNDARY WILL DEVELOP
ALONG THE TENN VALLEY FRI AFTN...AND WILL BECOME THE FOCUS FOR OUR
WEEKEND.
SATURDAY THROUGH TUESDAY... ENSEMBLES CONTINUE TO HOLD THE HIGH
AMPLITUDE RIDGE ALONG THE EASTERN CONUS WITH THE AFOREMENTIONED
TROUGH REMAINING ACROSS THE SOUTHERN ROCKIES/SOUTHWEST CONUS SAT.
OPERATIONAL GUIDANCE HAS BEEN IN GOOD AGREEMENT WITH A VORT MAX
EJECTING FROM THE TROUGH SAT WITH A SHORTWAVE DEVELOPING ALONG THE
SOUTHERN PLAINS. THIS FEATURE IS PROGGED TO ENERGIZE THE QUASI-
STATIONARY BOUNDARY AND LIFT NORTH. SIMULTANEOUSLY A SFC RIDGE IS
PROGGED TO DROP SOUTH FROM CENTRAL CANADA AND COVER MUCH OF THE
UPPER MIDWEST. THE INITIAL WAVE WILL BRING PRECIP BACK TO THE AREA
SAT/SAT NGT...THEN STRONG SFC RIDGE ACROSS THE HIGH PLAINS WILL
STEER THE BOUNDARY BACK SOUTH SUN.
THE MAIN CONCERN WILL BE ON THE DIRECTION AND STRENGTH OF THE
CANADIAN SFC RIDGE OVER THE NORTHERN PLAINS. GUIDANCE INDICATES THIS
FEATURE WILL SLIDE EAST AND COULD DEVELOP A SHARP BAROCLINIC ZONE
ACROSS THE GREAT LAKES REGION. WITH WINDS TURNING NORTHEAST AND A
BOUNDARY LIFTING BACK NORTH SUN NGT/MON...P-TYPE CONCERNS COULD BE
INTRODUCED BEFORE TEMPS WARM ENOUGH.
TEMPS SAT WILL WARM BACK INTO THE UPR 40S TO LOW 50S...THEN WITH THE
BOUNDARY SLIDING SOUTH SUN HIGHS WILL REMAIN IN THE UPR 30S TO LOW
40S. THEN FOR THE REMAINDER OF THE EXTENDED TEMPS COULD TREND BACK
TOWARDS THE MID/UPR 30S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* POTENTIAL FOR A FEW ADDITIONAL STRONG STORMS EARLY THIS EVENING
(01-03 UTC).
* INCREASING SOUTHERLY WINDS THIS AFTERNOON.
* POTENTIAL FOR VERY STRONG SOUTHWESTERLY WINDS FOR A SHORT PERIOD
THIS EVENING BETWEEN 03-06 UTC. GUSTS OF 45 TO 50 KT POSSIBLE
DURING THIS PERIOD.
KJB
//DISCUSSION...UPDATED 18Z...
A SIGNIFICANT STORM SYSTEM WILL CONTINUE TO IMPACT THE REGION INTO
TONIGHT. THE MAIN AVIATION WEATHER CONCERNS WILL BE THE POTENTIAL
FOR ADDITIONAL SCT STRONG THUNDERSTORMS EARLY THIS EVENING...GUSTY
SOUTH WINDS THIS AFTERNOON...FOLLOWED BY A PERIOD OF VERY STRONG
GUSTY SYNOPTIC SOUTHWESTERLY WINDS LATER THIS EVENING.
CURRENTLY AN AREA OF MAINLY SHOWERS...WITH A FEW EMBEDDED
THUNDERSTORMS...CONTINUES TO MOVE ACROSS THE EASTERN AIRFIELDS AS A
WARM FRONT GRADUALLY SHIFTS NORTHWARD OVER THE AREA. THIS SHOWERS
ACTIVITY WILL BEGIN TO MOVE OUT OF THE AREA AROUND...OR SLIGHTLY
AFTER THE 19 UTC HOUR...WITH ONLY SOME WIDELY SCT SHOWERS POSSIBLE
THEREAFTER. CIGS AND VSBYS WILL ALSO BE IMPROVING THIS
AFTERNOON...THOUGH THE SURFACE WINDS WILL CONTINUE TO BECOME DUE
SOUTHERLY AND GUSTY...UP AROUND 30 KT THROUGH THE REST OF THE
AFTERNOON.
ANOTHER BATCH OF SCATTERED THUNDERSTORMS MAY DEVELOP VERY LATE THIS
AFTERNOON OVER WESTERN ILLINOIS AHEAD OF AN APPROACHING COLD FRONT.
THESE STORMS COULD THEN PROGRESS EAST-NORTHEASTWARD OVER THE EASTERN
TERMINALS EARLY THIS EVENING...ROUGHLY BETWEEN 00 AND 03 UTC THIS
EVENING. THE POTENTIAL FOR STORMS AT A GIVEN TERMINAL WILL LIKELY BE
FAIRLY SHORT (UNDER AN HOUR)...THOUGH EXACT TIMING REQUIRES A 2 HOUR
TEMPO AT THIS RANGE. THESE POTENTIAL STORMS ALSO HAVE A CONDITIONAL
RISK OF BEING SEVERE WITH STRONG SURFACE WINDS.
FOLLOWING THE COLD FRONTAL PASSAGE...AROUND 02-03 UTC THIS
EVENING...IT APPEARS THAT THE SURFACE WINDS OUTSIDE OF THUNDERSTORMS
COULD BECOME VERY STRONG FOR A SHORT PERIOD. VERY STRONG PRESSURE
RISES LOOK TO OVERSPREAD THE AREA BEHIND THIS FRONT...AND THIS COULD
LEAD TO VERY EFFICIENT TRANSPORT OF STRONGER WINDS ALOFT TO THE
SURFACE MID TO LATE THIS EVENING. WIND GUSTS COULD BRIEFLY GUST IN
THE 45 TO 50 KT RANGE DURING THIS PERIOD...BEFORE ABATING
OVERNIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM WITH TSRA/TIMING THIS EVENING.
* MEDIUM HIGH WITH WIND FORECAST.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR.
SATURDAY...SHOWERS. CHANCE OF MVFR/IFR.
SUNDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
446 AM CST
SIGNIFICANT CHANGES MADE TO WINDS/WAVES FOR THIS FORECAST
PERIOD...WITH STORM FORCE WINDS AND GALES LIKELY ACROSS THE ENTIRE
LAKE LATER TODAY...TONIGHT...AND THURSDAY.
SOUTHEAST WINDS WILL CONTINUE TO INCREASE TODAY AS LOW PRESSURE OVER
THE CENTRAL PLAINS LIFTS NORTHEAST ACROSS THE REGION. EXPECT WINDS
TO REALLY RAMP UP THIS AFTERNOON...WITH TO 30KT WINDS BEING OBSERVED
ACROSS ALL OF THE LAKE. ALTHOUGH NOT OVERLY CONFIDENT...DO THINK
THERE WILL BE AT LEAST GALE FORCE GUSTS ACROSS THE NEARSHORE WATERS
AND SOUTH HALF OF THE LAKE THIS AFTERNOON...AND HAVE THAT INCLUDED
IN THE FORECAST. WINDS WILL FURTHER INCREASE TONIGHT WITH HIGH END
GALES TO 45 KT EXPECTED ACROSS THE SOUTH HALF AND NEARSHORE...AND
THEN STORM FORCE WINDS TO 50KT ACROSS THE NORTH HALF. THERE WILL
BE A POSSIBILITY FOR STORM FORCE WINDS ACROSS THE SOUTH HALF AND
NEARSHORE...BUT AT THIS TIME...THIS LOOKS TO BE ONLY FOR A SMALL
WINDOW. HOWEVER...WILL NEED TO MONITOR THE POTENTIAL FOR A LONGER
PERIOD OF POSSIBLE STORM FORCE WINDS IN THOSE LOCATIONS. WINDS
WILL BEGIN TO COME DOWN ON THURSDAY...BUT WITH STORM AND GALES
HOLDING ONTO A LITTLE LONGER ON THE NORTH HALF. HAVE GALES GOING
ACROSS THE NORTH INTO THE AFTERNOON...BUT THERE IS A POSSIBILITY
THAT THEY MAY CONTINUE EVEN INTO IN THE EVENING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039...6 PM WEDNESDAY TO 3 AM THURSDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...6 PM
WEDNESDAY TO 3 AM THURSDAY.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...6 PM WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...3 AM
THURSDAY TO 6 AM THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...9 PM WEDNESDAY TO 3 AM THURSDAY.
DENSE FOG ADVISORY...LMZ777-LMZ779 UNTIL 6 PM WEDNESDAY.
GALE WARNING...LMZ777-LMZ779...3 AM THURSDAY TO 9 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
236 PM CST WED DEC 23 2015
.MESOSCALE DISCUSSION...
1230 PM CST
THE FIRST BATCH OF SHOWERS AND THUNDERSTORMS IS EXITING THE AREA
TOWARD THE EAST EARLY THIS AFTERNOON WHILE THE NEXT ROUND IS
APPROACHING OUT OF SOUTHWEST ILLINOIS. BOTH AREAS OF SHOWERS
APPEAR TO BE CORRELATED WITH PRONOUNCED MOISTURE CONVERGENCE AS
DEPICTED IN THE LATEST RUNS OF THE RAP MODEL. THE SECOND AXIS
WOULD BE EXPANDING ACROSS THE AREA IN THE 20-22 UTC TIMEFRAME
ACCORDING TO THE RAP...OR MAYBE A BIT EARLIER ACCORDING TO AN
EXTRAPOLATION OF EXISTING UPSTREAM ACTIVITY. THE GREATEST CONCERNS
WITH THIS SECOND CLUSTER OF ACTIVITY...MUCH OF IT AS STRATIFORM
WITH SOME EMBEDDED CELLS...WOULD APPEAR TO BE STRONG WINDS AND
HEAVY RAIN.
THERE ALSO ARE SIGNALS THAT A THIRD AREA OF SCATTERED CONVECTION
MAY DEVELOP ACROSS NORTHWEST ILLINOIS IN THE 20-00 UTC TIMEFRAME
THIS AFTERNOON CLOSER TO THE LOW AND THE APPROACHING WARM FRONT.
THIS WOULD BE ASSOCIATED WITH THE AREA OF CLEARING SEEN IN VIS
SATELLITE IMAGERY LIFTING OUT OF MISSOURI. THE POTENTIAL FOR THIS
CONVECTION TO REMAIN SURFACE BASED AND DISCRETE...AND ITS
PROXIMITY TO THE SURFACE LOW...WOULD RAISE CONCERNS FOR A
POTENTIALLY WIDER VARIETY OF SEVERE WEATHER.
LENNING
&&
.SHORT TERM...
236 PM CST
THROUGH THURSDAY...
A DEEP UPPER TROUGH IS OVER THE CENTRAL CONUS WITH A STRONG MID
LEVEL SHORTWAVE TRACKING NEWD THROUGH THE UPPER MISSOURI VALLEY. A
SERIES OF WEAKER SHORTWAVES HAVE BEEN TRACKING NEWD THROUGH THE
MIDDLE MISSISSIPPI VALLEY...GENERATING SCT STRONG THUNDERSTORMS AS
FAR NORTH AS NERN IL AND NWRN IN EARLIER TODAY. THE SRN STREAM
SHORTWAVE ENERGY IS BEGINNING TO FOCUS TSRA OVER THE LOWER OHIO
VALLEY AND INTO INDIANA THIS AFTERNOON AND THE MAIN AREA OF CONCERN
WITH RESPECT TO TSRA ACTIVITY FOR THE LOCAL AREA WILL BE UNDER THE
MID LEVEL CIRCULATION CENTER. UNDER THE COLD CORE UPPER LOW AND
WITH UNSEASONABLY WARM...MOIST AIR IN PLACE OVER THE REGION...STRONG
LAPSE RATES AND MODEST LOW LEVEL INSTABILITY WILL KEEP A CHANCE FOR
THUNDERSTORMS INTO THE EVENING HOURS. THE LATEST SATELLITE IMAGERY
SHOWS SOME BREAKS IN THE OVERCAST UNDER THE UPPER LOW WITH SOME
CONVECTIVE CLOUD DEVELOPMENT APPARENT. SOME OF THIS ACTIVITY IS
ALREADY GENERATING LIGHTNING OVER IOWA AND NERN MO. LATEST SPC
MESOSCALE ANALYSIS INDICATES AN AREA OF LOW LEVEL INSTABILITY
CONSISTENT WITH THE CURRENT CONVECTIVE DEVELOPMENT AND THE SHORT
RANGE HIGH RES MODEL GUIDANCE INDICATES THAT THERE IS A CHANCE FOR
THUNDERSTORM ACTIVITY TO MAINTAIN INTO THE EVENING HOURS...MOSTLY
ACROSS NRN IL. ALSO...MORNING SOUNDINGS INDICATE STRONG VERTICAL
SHEAR FROM THE SFC THROUGH MID LEVELS...SO LOW-TOPPED SUPERCELL
DEVELOPMENT REMAIN A POSSIBILITY STRONG...DAMAGING WIND...ISOLATED
LARGE HAIL AND A FEW TORNADOES WILL REMAIN A POSSIBILITY INTO THE
EVENING.
ANOTHER CONCERN FOR THE EVENING AND INTO THE OVERNIGHT HOURS WILL BE
STRONG SYNOPTIC SCALE WINDS. AS THE MAIN SFC LOW QUICKLY LIFTS NEWD
FROM ERN IOWA THIS AFTERNOON TO LAKE SUPERIOR WHILE DEEPENING AT
LEAST 10MB BY ARND 06Z...STRONG PRESSURE RISES IN THE WAKE OF THE
LOW WILL HELP GENERATE STRONG SLWY-WLY WINDS WITH SUSTAINED SPEEDS
ARND 30 MPH AND GUSTS OF 40-50 MPH. THE PERIOD OF THE STRONGEST
WINDS WILL BE FROM ARND 03-09Z WHICH WILL BE THE PERIOD OF THE
STRONGEST PRESSURE RISES.
FOR THURSDAY...CONDITIONS WILL BE MUCH QUIETER AS HIGH PRESSURE
BUILDS ACROSS THE REGION. EVEN WITH A STRONG COLD FRONT EXPECTED TO
MOVE ACROSS THE REGION AS THE SFC LOW LIFTS TO THE
NORTHEAST...TEMPERATURES WILL REMAIN ABOVE SEASONABLE NORMAL LEVELS
WITH HIGHS RANGING FROM AROUND 40F OVER THE ROCKFORD AREA TO THE
UPPER 40S SOUTH OF A VALPARAISO TO PONTIAC LINE.
KREIN
&&
.LONG TERM...
316 AM CST
THURSDAY THROUGH TUESDAY...
THURSDAY THROUGH FRIDAY...
ANTI-CYCLONIC FLOW QUICKLY ARRIVES EARLY THUR IN THE WAKE OF THE
DEPARTING TROUGH. THE 500MB PATTERN DOES BECOME QUASI-ZONAL FOR
THUR/FRI...WHICH WILL HELP TO KEEP TEMPS STILL SEVERAL DEGREES
ABOVE CLIMO IN THE LOW/MID 40S CHRISTMAS DAYAND POSSIBLY UPR 40S
FRI. DESPITE THE SFC RIDGE SLIDING OVERHEAD CHRISTMAS DAY...SKIES
WILL AT BEST BECOME P-CLOUDY IN THE AFTERNOON. THE DRY WEATHER
WILL ONLY BE SHORT-LIVED THROUGH FRI...AS THE ACTIVE PATTERN
BEGINS TO RAMP BACK-UP AS A TROUGH DIGS INTO THE FOUR- CORNERS
REGION OF THE CONUS. A QUASI-STATIONARY BOUNDARY WILL DEVELOP
ALONG THE TENN VALLEY FRI AFTN...AND WILL BECOME THE FOCUS FOR OUR
WEEKEND.
SATURDAY THROUGH TUESDAY... ENSEMBLES CONTINUE TO HOLD THE HIGH
AMPLITUDE RIDGE ALONG THE EASTERN CONUS WITH THE AFOREMENTIONED
TROUGH REMAINING ACROSS THE SOUTHERN ROCKIES/SOUTHWEST CONUS SAT.
OPERATIONAL GUIDANCE HAS BEEN IN GOOD AGREEMENT WITH A VORT MAX
EJECTING FROM THE TROUGH SAT WITH A SHORTWAVE DEVELOPING ALONG THE
SOUTHERN PLAINS. THIS FEATURE IS PROGGED TO ENERGIZE THE QUASI-
STATIONARY BOUNDARY AND LIFT NORTH. SIMULTANEOUSLY A SFC RIDGE IS
PROGGED TO DROP SOUTH FROM CENTRAL CANADA AND COVER MUCH OF THE
UPPER MIDWEST. THE INITIAL WAVE WILL BRING PRECIP BACK TO THE AREA
SAT/SAT NGT...THEN STRONG SFC RIDGE ACROSS THE HIGH PLAINS WILL
STEER THE BOUNDARY BACK SOUTH SUN.
THE MAIN CONCERN WILL BE ON THE DIRECTION AND STRENGTH OF THE
CANADIAN SFC RIDGE OVER THE NORTHERN PLAINS. GUIDANCE INDICATES THIS
FEATURE WILL SLIDE EAST AND COULD DEVELOP A SHARP BAROCLINIC ZONE
ACROSS THE GREAT LAKES REGION. WITH WINDS TURNING NORTHEAST AND A
BOUNDARY LIFTING BACK NORTH SUN NGT/MON...P-TYPE CONCERNS COULD BE
INTRODUCED BEFORE TEMPS WARM ENOUGH.
TEMPS SAT WILL WARM BACK INTO THE UPR 40S TO LOW 50S...THEN WITH THE
BOUNDARY SLIDING SOUTH SUN HIGHS WILL REMAIN IN THE UPR 30S TO LOW
40S. THEN FOR THE REMAINDER OF THE EXTENDED TEMPS COULD TREND BACK
TOWARDS THE MID/UPR 30S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* POTENTIAL FOR A FEW ADDITIONAL STRONG STORMS EARLY THIS EVENING
(01-03 UTC).
* INCREASING SOUTHERLY WINDS THIS AFTERNOON.
* POTENTIAL FOR VERY STRONG SOUTHWESTERLY WINDS FOR A SHORT PERIOD
THIS EVENING BETWEEN 03-06 UTC. GUSTS OF 45 TO 50 KT POSSIBLE
DURING THIS PERIOD.
KJB
//DISCUSSION...UPDATED 18Z...
A SIGNIFICANT STORM SYSTEM WILL CONTINUE TO IMPACT THE REGION INTO
TONIGHT. THE MAIN AVIATION WEATHER CONCERNS WILL BE THE POTENTIAL
FOR ADDITIONAL SCT STRONG THUNDERSTORMS EARLY THIS EVENING...GUSTY
SOUTH WINDS THIS AFTERNOON...FOLLOWED BY A PERIOD OF VERY STRONG
GUSTY SYNOPTIC SOUTHWESTERLY WINDS LATER THIS EVENING.
CURRENTLY AN AREA OF MAINLY SHOWERS...WITH A FEW EMBEDDED
THUNDERSTORMS...CONTINUES TO MOVE ACROSS THE EASTERN AIRFIELDS AS A
WARM FRONT GRADUALLY SHIFTS NORTHWARD OVER THE AREA. THIS SHOWERS
ACTIVITY WILL BEGIN TO MOVE OUT OF THE AREA AROUND...OR SLIGHTLY
AFTER THE 19 UTC HOUR...WITH ONLY SOME WIDELY SCT SHOWERS POSSIBLE
THEREAFTER. CIGS AND VSBYS WILL ALSO BE IMPROVING THIS
AFTERNOON...THOUGH THE SURFACE WINDS WILL CONTINUE TO BECOME DUE
SOUTHERLY AND GUSTY...UP AROUND 30 KT THROUGH THE REST OF THE
AFTERNOON.
ANOTHER BATCH OF SCATTERED THUNDERSTORMS MAY DEVELOP VERY LATE THIS
AFTERNOON OVER WESTERN ILLINOIS AHEAD OF AN APPROACHING COLD FRONT.
THESE STORMS COULD THEN PROGRESS EAST-NORTHEASTWARD OVER THE EASTERN
TERMINALS EARLY THIS EVENING...ROUGHLY BETWEEN 00 AND 03 UTC THIS
EVENING. THE POTENTIAL FOR STORMS AT A GIVEN TERMINAL WILL LIKELY BE
FAIRLY SHORT (UNDER AN HOUR)...THOUGH EXACT TIMING REQUIRES A 2 HOUR
TEMPO AT THIS RANGE. THESE POTENTIAL STORMS ALSO HAVE A CONDITIONAL
RISK OF BEING SEVERE WITH STRONG SURFACE WINDS.
FOLLOWING THE COLD FRONTAL PASSAGE...AROUND 02-03 UTC THIS
EVENING...IT APPEARS THAT THE SURFACE WINDS OUTSIDE OF THUNDERSTORMS
COULD BECOME VERY STRONG FOR A SHORT PERIOD. VERY STRONG PRESSURE
RISES LOOK TO OVERSPREAD THE AREA BEHIND THIS FRONT...AND THIS COULD
LEAD TO VERY EFFICIENT TRANSPORT OF STRONGER WINDS ALOFT TO THE
SURFACE MID TO LATE THIS EVENING. WIND GUSTS COULD BRIEFLY GUST IN
THE 45 TO 50 KT RANGE DURING THIS PERIOD...BEFORE ABATING
OVERNIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM WITH TSRA/TIMING THIS EVENING.
* MEDIUM HIGH WITH WIND FORECAST.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR.
SATURDAY...SHOWERS. CHANCE OF MVFR/IFR.
SUNDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
446 AM CST
SIGNIFICANT CHANGES MADE TO WINDS/WAVES FOR THIS FORECAST
PERIOD...WITH STORM FORCE WINDS AND GALES LIKELY ACROSS THE ENTIRE
LAKE LATER TODAY...TONIGHT...AND THURSDAY.
SOUTHEAST WINDS WILL CONTINUE TO INCREASE TODAY AS LOW PRESSURE OVER
THE CENTRAL PLAINS LIFTS NORTHEAST ACROSS THE REGION. EXPECT WINDS
TO REALLY RAMP UP THIS AFTERNOON...WITH TO 30KT WINDS BEING OBSERVED
ACROSS ALL OF THE LAKE. ALTHOUGH NOT OVERLY CONFIDENT...DO THINK
THERE WILL BE AT LEAST GALE FORCE GUSTS ACROSS THE NEARSHORE WATERS
AND SOUTH HALF OF THE LAKE THIS AFTERNOON...AND HAVE THAT INCLUDED
IN THE FORECAST. WINDS WILL FURTHER INCREASE TONIGHT WITH HIGH END
GALES TO 45 KT EXPECTED ACROSS THE SOUTH HALF AND NEARSHORE...AND
THEN STORM FORCE WINDS TO 50KT ACROSS THE NORTH HALF. THERE WILL
BE A POSSIBILITY FOR STORM FORCE WINDS ACROSS THE SOUTH HALF AND
NEARSHORE...BUT AT THIS TIME...THIS LOOKS TO BE ONLY FOR A SMALL
WINDOW. HOWEVER...WILL NEED TO MONITOR THE POTENTIAL FOR A LONGER
PERIOD OF POSSIBLE STORM FORCE WINDS IN THOSE LOCATIONS. WINDS
WILL BEGIN TO COME DOWN ON THURSDAY...BUT WITH STORM AND GALES
HOLDING ONTO A LITTLE LONGER ON THE NORTH HALF. HAVE GALES GOING
ACROSS THE NORTH INTO THE AFTERNOON...BUT THERE IS A POSSIBILITY
THAT THEY MAY CONTINUE EVEN INTO IN THE EVENING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039...6 PM WEDNESDAY TO 3 AM THURSDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...6 PM
WEDNESDAY TO 3 AM THURSDAY.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...6 PM WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...3 AM
THURSDAY TO 6 AM THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...9 PM WEDNESDAY TO 3 AM THURSDAY.
DENSE FOG ADVISORY...LMZ777-LMZ779 UNTIL 6 PM WEDNESDAY.
GALE WARNING...LMZ777-LMZ779...3 AM THURSDAY TO 9 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
158 PM CST WED DEC 23 2015
.MESOSCALE DISCUSSION...
1230 PM CST
THE FIRST BATCH OF SHOWERS AND THUNDERSTORMS IS EXITING THE AREA
TOWARD THE EAST EARLY THIS AFTERNOON WHILE THE NEXT ROUND IS
APPROACHING OUT OF SOUTHWEST ILLINOIS. BOTH AREAS OF SHOWERS
APPEAR TO BE CORRELATED WITH PRONOUNCED MOISTURE CONVERGENCE AS
DEPICTED IN THE LATEST RUNS OF THE RAP MODEL. THE SECOND AXIS
WOULD BE EXPANDING ACROSS THE AREA IN THE 20-22 UTC TIMEFRAME
ACCORDING TO THE RAP...OR MAYBE A BIT EARLIER ACCORDING TO AN
EXTRAPOLATION OF EXISTING UPSTREAM ACTIVITY. THE GREATEST CONCERNS
WITH THIS SECOND CLUSTER OF ACTIVITY...MUCH OF IT AS STRATIFORM
WITH SOME EMBEDDED CELLS...WOULD APPEAR TO BE STRONG WINDS AND
HEAVY RAIN.
THERE ALSO ARE SIGNALS THAT A THIRD AREA OF SCATTERED CONVECTION
MAY DEVELOP ACROSS NORTHWEST ILLINOIS IN THE 20-00 UTC TIMEFRAME
THIS AFTERNOON CLOSER TO THE LOW AND THE APPROACHING WARM FRONT.
THIS WOULD BE ASSOCIATED WITH THE AREA OF CLEARING SEEN IN VIS
SATELLITE IMAGERY LIFTING OUT OF MISSOURI. THE POTENTIAL FOR THIS
CONVECTION TO REMAIN SURFACE BASED AND DISCRETE...AND ITS
PROXIMITY TO THE SURFACE LOW...WOULD RAISE CONCERNS FOR A
POTENTIALLY WIDER VARIETY OF SEVERE WEATHER.
LENNING
&&
.SHORT TERM...
316 AM CST
THROUGH TONIGHT...
EARLY THIS MORNING AREAS OF FOG HAVE DEVELOPED WITH A FEW POCKETS
OF DENSE FOG. TEMPS HAVE CONTINUED TO SLOWLY RISE INTO THE MID/UPR
40S...WITH DEW POINTS EQUALLY RISING INTO THE LOW 40S. SFC WINDS
HAVE BACKED TO THE SOUTHEAST WITH SHALLOW STRATUS CLOUDS BLANKETED
ACROSS MUCH OF THE REGION. THE WARM FRONTAL BOUNDARY REMAINS
ORIENTED ACROSS CENTRAL ILLINOIS...AND STEADILY LIFTING NORTH.
ALONG AND SOUTH OF THIS BOUNDARY TEMPS/DEW POINTS HAVE RISEN INTO
THE LOW 50S WITH STRONGER SOUTHERLY WINDS HELPING TO PUMP
ADDITIONAL WARM AIR NORTH.
THE MAIN CONCERN REMAINS ON THE POTENTIAL FOR SEVERE STORMS LATER
TODAY INTO EARLY THIS EVENING. OPERATIONAL GUIDANCE CONTINUES TO
LIFT THE WARM/MOIST BOUNDARY NORTH ACROSS THE FORECAST AREA THIS
MORNING. RAIN IS EXPECTED TO OVERSPREAD THE AREA BY LATE MORNING. IR
IMAGERY EARLY THIS MORNING SHOWS A DRY WEDGE ACROSS CENTRAL
OKLAHOMA...AND HI-RES OPERATIONAL GUIDANCE HAS INITIALIZED THIS
FEATURE WELL. BY MIDDAY THIS FEATURE WILL BE LIFTING INTO CENTRAL
MISSOURI...WHICH COULD BRING A BRIEF LULL IN RAIN ACROSS THE
FORECAST AREA BY MID AFTN. BY EARLY AFTN THE 500MB TROUGH WILL
BECOME NEGATIVELY TILTED WITH THE SPEED MAX POSITIONED OVER EASTERN
KANSAS AND LIFTING NORTHEAST TOWARDS EASTERN IOWA. THE DRY WEDGE MAY
HELP FURTHER DESTABILIZE THE AIRMASS ACROSS THE CWFA...HOWEVER THIS
REMAINS THE LARGEST CHALLENGE FOR SEVERE STORMS. LOW LEVEL SHEAR
REMAINS VERY STRONG JUST EAST OF THE SFC LOW TRACK...WHICH IS
PRESENTLY POISED TO CLIP FAR NORTHWEST IL LATE THIS AFTN. THIS COULD
SUPPORT AN ISOLATED TORNADO THREAT IN THIS MOST SHEARED AREA.
NONETHELESS...THE 40-55KT LOW LEVEL JET WILL EQUALLY SUPPORT FAST
MOVING STORMS IF THEY ARE CAPABLE OF DEVELOPING...WHICH MAINTAINS
THE DAMAGING WIND THREAT. HIGHS TODAY COULD BREAK RECORDS IN MANY
AREAS OF NORTHERN IL. CURRENT EXPECTATION IS THAT TEMPS WILL RISE TO
AROUND 60 AND PERHAPS THE MIDDLE 60S ACROSS PORTIONS OF THE SOUTHERN
CWFA.
THE SEVERE THREAT WILL CONTINUE TO JUST BEYOND 00Z...BUT SHOULD BE
QUICKLY PIVOTING EAST BY 2-3Z OF THE CWFA. SO HAVE ONLY HELD ONTO
THE SEVERE WORDING IN THE FORECAST UNTIL THIS TIMEFRAME...WITH MOST
OPERATIONAL GUIDANCE RAPIDLY ERODING THE MOISTURE TO THE NORTHEAST
IN THE WAKE OF THE STRONG SFC LOW. IN ADDITION TO THE AFTN/EARLY EVE
SEVERE THREAT...AND AS ELUDED TO WITH THE STRONG LOW LEVEL
WINDS...THE ISALLOBARIC PRESSURE RISES ON THE BACKSIDE OF THE
SHORTWAVE WILL BE SUPPORTIVE OF AT LEAST GUSTS TO 45 MPH OR WIND
ADVISORY CRITERIA...BUT A FEW GUSTS COULD APPROACH WIND WARNING
CRITERIA.
BEACHLER
&&
.LONG TERM...
316 AM CST
THURSDAY THROUGH TUESDAY...
THURSDAY THROUGH FRIDAY...
ANTI-CYCLONIC FLOW QUICKLY ARRIVES EARLY THUR IN THE WAKE OF THE
DEPARTING TROUGH. THE 500MB PATTERN DOES BECOME QUASI-ZONAL FOR
THUR/FRI...WHICH WILL HELP TO KEEP TEMPS STILL SEVERAL DEGREES
ABOVE CLIMO IN THE LOW/MID 40S CHRISTMAS DAYAND POSSIBLY UPR 40S
FRI. DESPITE THE SFC RIDGE SLIDING OVERHEAD CHRISTMAS DAY...SKIES
WILL AT BEST BECOME P-CLOUDY IN THE AFTERNOON. THE DRY WEATHER
WILL ONLY BE SHORT-LIVED THROUGH FRI...AS THE ACTIVE PATTERN
BEGINS TO RAMP BACK-UP AS A TROUGH DIGS INTO THE FOUR- CORNERS
REGION OF THE CONUS. A QUASI-STATIONARY BOUNDARY WILL DEVELOP
ALONG THE TENN VALLEY FRI AFTN...AND WILL BECOME THE FOCUS FOR OUR
WEEKEND.
SATURDAY THROUGH TUESDAY... ENSEMBLES CONTINUE TO HOLD THE HIGH
AMPLITUDE RIDGE ALONG THE EASTERN CONUS WITH THE AFOREMENTIONED
TROUGH REMAINING ACROSS THE SOUTHERN ROCKIES/SOUTHWEST CONUS SAT.
OPERATIONAL GUIDANCE HAS BEEN IN GOOD AGREEMENT WITH A VORT MAX
EJECTING FROM THE TROUGH SAT WITH A SHORTWAVE DEVELOPING ALONG THE
SOUTHERN PLAINS. THIS FEATURE IS PROGGED TO ENERGIZE THE QUASI-
STATIONARY BOUNDARY AND LIFT NORTH. SIMULTANEOUSLY A SFC RIDGE IS
PROGGED TO DROP SOUTH FROM CENTRAL CANADA AND COVER MUCH OF THE
UPPER MIDWEST. THE INITIAL WAVE WILL BRING PRECIP BACK TO THE AREA
SAT/SAT NGT...THEN STRONG SFC RIDGE ACROSS THE HIGH PLAINS WILL
STEER THE BOUNDARY BACK SOUTH SUN.
THE MAIN CONCERN WILL BE ON THE DIRECTION AND STRENGTH OF THE
CANADIAN SFC RIDGE OVER THE NORTHERN PLAINS. GUIDANCE INDICATES THIS
FEATURE WILL SLIDE EAST AND COULD DEVELOP A SHARP BAROCLINIC ZONE
ACROSS THE GREAT LAKES REGION. WITH WINDS TURNING NORTHEAST AND A
BOUNDARY LIFTING BACK NORTH SUN NGT/MON...P-TYPE CONCERNS COULD BE
INTRODUCED BEFORE TEMPS WARM ENOUGH.
TEMPS SAT WILL WARM BACK INTO THE UPR 40S TO LOW 50S...THEN WITH THE
BOUNDARY SLIDING SOUTH SUN HIGHS WILL REMAIN IN THE UPR 30S TO LOW
40S. THEN FOR THE REMAINDER OF THE EXTENDED TEMPS COULD TREND BACK
TOWARDS THE MID/UPR 30S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* POTENTIAL FOR A FEW ADDITIONAL STRONG STORMS EARLY THIS EVENING
(01-03 UTC).
* INCREASING SOUTHERLY WINDS THIS AFTERNOON.
* POTENTIAL FOR VERY STRONG SOUTHWESTERLY WINDS FOR A SHORT PERIOD
THIS EVENING BETWEEN 03-06 UTC. GUSTS OF 45 TO 50 KT POSSIBLE
DURING THIS PERIOD.
KJB
//DISCUSSION...UPDATED 18Z...
A SIGNIFICANT STORM SYSTEM WILL CONTINUE TO IMPACT THE REGION INTO
TONIGHT. THE MAIN AVIATION WEATHER CONCERNS WILL BE THE POTENTIAL
FOR ADDITIONAL SCT STRONG THUNDERSTORMS EARLY THIS EVENING...GUSTY
SOUTH WINDS THIS AFTERNOON...FOLLOWED BY A PERIOD OF VERY STRONG
GUSTY SYNOPTIC SOUTHWESTERLY WINDS LATER THIS EVENING.
CURRENTLY AN AREA OF MAINLY SHOWERS...WITH A FEW EMBEDDED
THUNDERSTORMS...CONTINUES TO MOVE ACROSS THE EASTERN AIRFIELDS AS A
WARM FRONT GRADUALLY SHIFTS NORTHWARD OVER THE AREA. THIS SHOWERS
ACTIVITY WILL BEGIN TO MOVE OUT OF THE AREA AROUND...OR SLIGHTLY
AFTER THE 19 UTC HOUR...WITH ONLY SOME WIDELY SCT SHOWERS POSSIBLE
THEREAFTER. CIGS AND VSBYS WILL ALSO BE IMPROVING THIS
AFTERNOON...THOUGH THE SURFACE WINDS WILL CONTINUE TO BECOME DUE
SOUTHERLY AND GUSTY...UP AROUND 30 KT THROUGH THE REST OF THE
AFTERNOON.
ANOTHER BATCH OF SCATTERED THUNDERSTORMS MAY DEVELOP VERY LATE THIS
AFTERNOON OVER WESTERN ILLINOIS AHEAD OF AN APPROACHING COLD FRONT.
THESE STORMS COULD THEN PROGRESS EAST-NORTHEASTWARD OVER THE EASTERN
TERMINALS EARLY THIS EVENING...ROUGHLY BETWEEN 00 AND 03 UTC THIS
EVENING. THE POTENTIAL FOR STORMS AT A GIVEN TERMINAL WILL LIKELY BE
FAIRLY SHORT (UNDER AN HOUR)...THOUGH EXACT TIMING REQUIRES A 2 HOUR
TEMPO AT THIS RANGE. THESE POTENTIAL STORMS ALSO HAVE A CONDITIONAL
RISK OF BEING SEVERE WITH STRONG SURFACE WINDS.
FOLLOWING THE COLD FRONTAL PASSAGE...AROUND 02-03 UTC THIS
EVENING...IT APPEARS THAT THE SURFACE WINDS OUTSIDE OF THUNDERSTORMS
COULD BECOME VERY STRONG FOR A SHORT PERIOD. VERY STRONG PRESSURE
RISES LOOK TO OVERSPREAD THE AREA BEHIND THIS FRONT...AND THIS COULD
LEAD TO VERY EFFICIENT TRANSPORT OF STRONGER WINDS ALOFT TO THE
SURFACE MID TO LATE THIS EVENING. WIND GUSTS COULD BRIEFLY GUST IN
THE 45 TO 50 KT RANGE DURING THIS PERIOD...BEFORE ABATING
OVERNIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM WITH TSRA/TIMING THIS EVENING.
* MEDIUM HIGH WITH WIND FORECAST.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR.
SATURDAY...SHOWERS. CHANCE OF MVFR/IFR.
SUNDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
446 AM CST
SIGNIFICANT CHANGES MADE TO WINDS/WAVES FOR THIS FORECAST
PERIOD...WITH STORM FORCE WINDS AND GALES LIKELY ACROSS THE ENTIRE
LAKE LATER TODAY...TONIGHT...AND THURSDAY.
SOUTHEAST WINDS WILL CONTINUE TO INCREASE TODAY AS LOW PRESSURE OVER
THE CENTRAL PLAINS LIFTS NORTHEAST ACROSS THE REGION. EXPECT WINDS
TO REALLY RAMP UP THIS AFTERNOON...WITH TO 30KT WINDS BEING OBSERVED
ACROSS ALL OF THE LAKE. ALTHOUGH NOT OVERLY CONFIDENT...DO THINK
THERE WILL BE AT LEAST GALE FORCE GUSTS ACROSS THE NEARSHORE WATERS
AND SOUTH HALF OF THE LAKE THIS AFTERNOON...AND HAVE THAT INCLUDED
IN THE FORECAST. WINDS WILL FURTHER INCREASE TONIGHT WITH HIGH END
GALES TO 45 KT EXPECTED ACROSS THE SOUTH HALF AND NEARSHORE...AND
THEN STORM FORCE WINDS TO 50KT ACROSS THE NORTH HALF. THERE WILL
BE A POSSIBILITY FOR STORM FORCE WINDS ACROSS THE SOUTH HALF AND
NEARSHORE...BUT AT THIS TIME...THIS LOOKS TO BE ONLY FOR A SMALL
WINDOW. HOWEVER...WILL NEED TO MONITOR THE POTENTIAL FOR A LONGER
PERIOD OF POSSIBLE STORM FORCE WINDS IN THOSE LOCATIONS. WINDS
WILL BEGIN TO COME DOWN ON THURSDAY...BUT WITH STORM AND GALES
HOLDING ONTO A LITTLE LONGER ON THE NORTH HALF. HAVE GALES GOING
ACROSS THE NORTH INTO THE AFTERNOON...BUT THERE IS A POSSIBILITY
THAT THEY MAY CONTINUE EVEN INTO IN THE EVENING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039...6 PM WEDNESDAY TO 3 AM THURSDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...6 PM
WEDNESDAY TO 3 AM THURSDAY.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...6 PM WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...3 AM
THURSDAY TO 6 AM THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...9 PM WEDNESDAY TO 3 AM THURSDAY.
DENSE FOG ADVISORY...LMZ777-LMZ779 UNTIL 6 PM WEDNESDAY.
GALE WARNING...LMZ777-LMZ779...3 AM THURSDAY TO 9 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1236 PM CST WED DEC 23 2015
.MESOSCALE DISCUSSION...
1230 PM CST
THE FIRST BATCH OF SHOWERS AND THUNDERSTORMS IS EXITING THE AREA
TOWARD THE EAST EARLY THIS AFTERNOON WHILE THE NEXT ROUND IS
APPROACHING OUT OF SOUTHWEST ILLINOIS. BOTH AREAS OF SHOWERS
APPEAR TO BE CORRELATED WITH PRONOUNCED MOISTURE CONVERGENCE AS
DEPICTED IN THE LATEST RUNS OF THE RAP MODEL. THE SECOND AXIS
WOULD BE EXPANDING ACROSS THE AREA IN THE 20-22 UTC TIMEFRAME
ACCORDING TO THE RAP...OR MAYBE A BIT EARLIER ACCORDING TO AN
EXTRAPOLATION OF EXISTING UPSTREAM ACTIVITY. THE GREATEST CONCERNS
WITH THIS SECOND CLUSTER OF ACTIVITY...MUCH OF IT AS STRATIFORM
WITH SOME EMBEDDED CELLS...WOULD APPEAR TO BE STRONG WINDS AND
HEAVY RAIN.
THERE ALSO ARE SIGNALS THAT A THIRD AREA OF SCATTERED CONVECTION
MAY DEVELOP ACROSS NORTHWEST ILLINOIS IN THE 20-00 UTC TIMEFRAME
THIS AFTERNOON CLOSER TO THE LOW AND THE APPROACHING WARM FRONT.
THIS WOULD BE ASSOCIATED WITH THE AREA OF CLEARING SEEN IN VIS
SATELLITE IMAGERY LIFTING OUT OF MISSOURI. THE POTENTIAL FOR THIS
CONVECTION TO REMAIN SURFACE BASED AND DISCRETE...AND ITS
PROXIMITY TO THE SURFACE LOW...WOULD RAISE CONCERNS FOR A
POTENTIALLY WIDER VARIETY OF SEVERE WEATHER.
LENNING
&&
.SHORT TERM...
316 AM CST
THROUGH TONIGHT...
EARLY THIS MORNING AREAS OF FOG HAVE DEVELOPED WITH A FEW POCKETS
OF DENSE FOG. TEMPS HAVE CONTINUED TO SLOWLY RISE INTO THE MID/UPR
40S...WITH DEW POINTS EQUALLY RISING INTO THE LOW 40S. SFC WINDS
HAVE BACKED TO THE SOUTHEAST WITH SHALLOW STRATUS CLOUDS BLANKETED
ACROSS MUCH OF THE REGION. THE WARM FRONTAL BOUNDARY REMAINS
ORIENTED ACROSS CENTRAL ILLINOIS...AND STEADILY LIFTING NORTH.
ALONG AND SOUTH OF THIS BOUNDARY TEMPS/DEW POINTS HAVE RISEN INTO
THE LOW 50S WITH STRONGER SOUTHERLY WINDS HELPING TO PUMP
ADDITIONAL WARM AIR NORTH.
THE MAIN CONCERN REMAINS ON THE POTENTIAL FOR SEVERE STORMS LATER
TODAY INTO EARLY THIS EVENING. OPERATIONAL GUIDANCE CONTINUES TO
LIFT THE WARM/MOIST BOUNDARY NORTH ACROSS THE FORECAST AREA THIS
MORNING. RAIN IS EXPECTED TO OVERSPREAD THE AREA BY LATE MORNING. IR
IMAGERY EARLY THIS MORNING SHOWS A DRY WEDGE ACROSS CENTRAL
OKLAHOMA...AND HI-RES OPERATIONAL GUIDANCE HAS INITIALIZED THIS
FEATURE WELL. BY MIDDAY THIS FEATURE WILL BE LIFTING INTO CENTRAL
MISSOURI...WHICH COULD BRING A BRIEF LULL IN RAIN ACROSS THE
FORECAST AREA BY MID AFTN. BY EARLY AFTN THE 500MB TROUGH WILL
BECOME NEGATIVELY TILTED WITH THE SPEED MAX POSITIONED OVER EASTERN
KANSAS AND LIFTING NORTHEAST TOWARDS EASTERN IOWA. THE DRY WEDGE MAY
HELP FURTHER DESTABILIZE THE AIRMASS ACROSS THE CWFA...HOWEVER THIS
REMAINS THE LARGEST CHALLENGE FOR SEVERE STORMS. LOW LEVEL SHEAR
REMAINS VERY STRONG JUST EAST OF THE SFC LOW TRACK...WHICH IS
PRESENTLY POISED TO CLIP FAR NORTHWEST IL LATE THIS AFTN. THIS COULD
SUPPORT AN ISOLATED TORNADO THREAT IN THIS MOST SHEARED AREA.
NONETHELESS...THE 40-55KT LOW LEVEL JET WILL EQUALLY SUPPORT FAST
MOVING STORMS IF THEY ARE CAPABLE OF DEVELOPING...WHICH MAINTAINS
THE DAMAGING WIND THREAT. HIGHS TODAY COULD BREAK RECORDS IN MANY
AREAS OF NORTHERN IL. CURRENT EXPECTATION IS THAT TEMPS WILL RISE TO
AROUND 60 AND PERHAPS THE MIDDLE 60S ACROSS PORTIONS OF THE SOUTHERN
CWFA.
THE SEVERE THREAT WILL CONTINUE TO JUST BEYOND 00Z...BUT SHOULD BE
QUICKLY PIVOTING EAST BY 2-3Z OF THE CWFA. SO HAVE ONLY HELD ONTO
THE SEVERE WORDING IN THE FORECAST UNTIL THIS TIMEFRAME...WITH MOST
OPERATIONAL GUIDANCE RAPIDLY ERODING THE MOISTURE TO THE NORTHEAST
IN THE WAKE OF THE STRONG SFC LOW. IN ADDITION TO THE AFTN/EARLY EVE
SEVERE THREAT...AND AS ELUDED TO WITH THE STRONG LOW LEVEL
WINDS...THE ISALLOBARIC PRESSURE RISES ON THE BACKSIDE OF THE
SHORTWAVE WILL BE SUPPORTIVE OF AT LEAST GUSTS TO 45 MPH OR WIND
ADVISORY CRITERIA...BUT A FEW GUSTS COULD APPROACH WIND WARNING
CRITERIA.
BEACHLER
&&
.LONG TERM...
316 AM CST
THURSDAY THROUGH TUESDAY...
THURSDAY THROUGH FRIDAY...
ANTI-CYCLONIC FLOW QUICKLY ARRIVES EARLY THUR IN THE WAKE OF THE
DEPARTING TROUGH. THE 500MB PATTERN DOES BECOME QUASI-ZONAL FOR
THUR/FRI...WHICH WILL HELP TO KEEP TEMPS STILL SEVERAL DEGREES
ABOVE CLIMO IN THE LOW/MID 40S CHRISTMAS DAYAND POSSIBLY UPR 40S
FRI. DESPITE THE SFC RIDGE SLIDING OVERHEAD CHRISTMAS DAY...SKIES
WILL AT BEST BECOME P-CLOUDY IN THE AFTERNOON. THE DRY WEATHER
WILL ONLY BE SHORT-LIVED THROUGH FRI...AS THE ACTIVE PATTERN
BEGINS TO RAMP BACK-UP AS A TROUGH DIGS INTO THE FOUR- CORNERS
REGION OF THE CONUS. A QUASI-STATIONARY BOUNDARY WILL DEVELOP
ALONG THE TENN VALLEY FRI AFTN...AND WILL BECOME THE FOCUS FOR OUR
WEEKEND.
SATURDAY THROUGH TUESDAY... ENSEMBLES CONTINUE TO HOLD THE HIGH
AMPLITUDE RIDGE ALONG THE EASTERN CONUS WITH THE AFOREMENTIONED
TROUGH REMAINING ACROSS THE SOUTHERN ROCKIES/SOUTHWEST CONUS SAT.
OPERATIONAL GUIDANCE HAS BEEN IN GOOD AGREEMENT WITH A VORT MAX
EJECTING FROM THE TROUGH SAT WITH A SHORTWAVE DEVELOPING ALONG THE
SOUTHERN PLAINS. THIS FEATURE IS PROGGED TO ENERGIZE THE QUASI-
STATIONARY BOUNDARY AND LIFT NORTH. SIMULTANEOUSLY A SFC RIDGE IS
PROGGED TO DROP SOUTH FROM CENTRAL CANADA AND COVER MUCH OF THE
UPPER MIDWEST. THE INITIAL WAVE WILL BRING PRECIP BACK TO THE AREA
SAT/SAT NGT...THEN STRONG SFC RIDGE ACROSS THE HIGH PLAINS WILL
STEER THE BOUNDARY BACK SOUTH SUN.
THE MAIN CONCERN WILL BE ON THE DIRECTION AND STRENGTH OF THE
CANADIAN SFC RIDGE OVER THE NORTHERN PLAINS. GUIDANCE INDICATES THIS
FEATURE WILL SLIDE EAST AND COULD DEVELOP A SHARP BAROCLINIC ZONE
ACROSS THE GREAT LAKES REGION. WITH WINDS TURNING NORTHEAST AND A
BOUNDARY LIFTING BACK NORTH SUN NGT/MON...P-TYPE CONCERNS COULD BE
INTRODUCED BEFORE TEMPS WARM ENOUGH.
TEMPS SAT WILL WARM BACK INTO THE UPR 40S TO LOW 50S...THEN WITH THE
BOUNDARY SLIDING SOUTH SUN HIGHS WILL REMAIN IN THE UPR 30S TO LOW
40S. THEN FOR THE REMAINDER OF THE EXTENDED TEMPS COULD TREND BACK
TOWARDS THE MID/UPR 30S.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SHOWERS WITH EMBEDDED THUNDERSTORMS ENDING EARLY THIS AFTERNOON.
* POTENTIAL FOR A FEW ADDITIONAL STRONG STORMS EARLY THIS
EVENING.
* INCREASING SOUTHERLY WINDS THIS AFTERNOON.
* POTENTIAL FOR VERY STRONG SOUTHWESTERLY WINDS FOR A SHORT PERIOD
THIS EVENING BETWEEN 03-06 UTC. GUSTS OF 45 TO 50 KT POSSIBLE
DURING THIS PERIOD.
KJB
//DISCUSSION...UPDATED 18Z...
A SIGNIFICANT STORM SYSTEM WILL CONTINUE TO IMPACT THE REGION INTO
TONIGHT. THE MAIN AVIATION WEATHER CONCERNS WILL BE THE POTENTIAL
FOR ADDITIONAL SCT STRONG THUNDERSTORMS EARLY THIS EVENING...GUSTY
SOUTH WINDS THIS AFTERNOON...FOLLOWED BY A PERIOD OF VERY STRONG
GUSTY SYNOPTIC SOUTHWESTERLY WINDS LATER THIS EVENING.
CURRENTLY AN AREA OF MAINLY SHOWERS...WITH A FEW EMBEDDED
THUNDERSTORMS...CONTINUES TO MOVE ACROSS THE EASTERN AIRFIELDS AS A
WARM FRONT GRADUALLY SHIFTS NORTHWARD OVER THE AREA. THIS SHOWERS
ACTIVITY WILL BEGIN TO MOVE OUT OF THE AREA AROUND...OR SLIGHTLY
AFTER THE 19 UTC HOUR...WITH ONLY SOME WIDELY SCT SHOWERS POSSIBLE
THEREAFTER. CIGS AND VSBYS WILL ALSO BE IMPROVING THIS
AFTERNOON...THOUGH THE SURFACE WINDS WILL CONTINUE TO BECOME DUE
SOUTHERLY AND GUSTY...UP AROUND 30 KT THROUGH THE REST OF THE
AFTERNOON.
ANOTHER BATCH OF SCATTERED THUNDERSTORMS MAY DEVELOP VERY LATE THIS
AFTERNOON OVER WESTERN ILLINOIS AHEAD OF AN APPROACHING COLD FRONT.
THESE STORMS COULD THEN PROGRESS EAST-NORTHEASTWARD OVER THE EASTERN
TERMINALS EARLY THIS EVENING...ROUGHLY BETWEEN 00 AND 03 UTC THIS
EVENING. THE POTENTIAL FOR STORMS AT A GIVEN TERMINAL WILL LIKELY BE
FAIRLY SHORT (UNDER AN HOUR)...THOUGH EXACT TIMING REQUIRES A 2 HOUR
TEMPO AT THIS RANGE. THESE POTENTIAL STORMS ALSO HAVE A CONDITIONAL
RISK OF BEING SEVERE WITH STRONG SURFACE WINDS.
FOLLOWING THE COLD FRONTAL PASSAGE...AROUND 02-03 UTC THIS
EVENING...IT APPEARS THAT THE SURFACE WINDS OUTSIDE OF THUNDERSTORMS
COULD BECOME VERY STRONG FOR A SHORT PERIOD. VERY STRONG PRESSURE
RISES LOOK TO OVERSPREAD THE AREA BEHIND THIS FRONT...AND THIS COULD
LEAD TO VERY EFFICIENT TRANSPORT OF STRONGER WINDS ALOFT TO THE
SURFACE MID TO LATE THIS EVENING. WIND GUSTS COULD BRIEFLY GUST IN
THE 45 TO 50 KT RANGE DURING THIS PERIOD...BEFORE ABATING
OVERNIGHT.
KJB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM WITH TSRA/TIMING THIS EVENING.
* MEDIUM HIGH WITH WIND FORECAST.
KJB
//OUTLOOK FOR ORD/MDW FOR 00Z FRIDAY-12Z WEDNESDAY...UPDATED 12Z...
THURSDAY NIGHT...VFR.
FRIDAY...VFR.
SATURDAY...SHOWERS. CHANCE OF MVFR/IFR.
SUNDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
446 AM CST
SIGNIFICANT CHANGES MADE TO WINDS/WAVES FOR THIS FORECAST
PERIOD...WITH STORM FORCE WINDS AND GALES LIKELY ACROSS THE ENTIRE
LAKE LATER TODAY...TONIGHT...AND THURSDAY.
SOUTHEAST WINDS WILL CONTINUE TO INCREASE TODAY AS LOW PRESSURE OVER
THE CENTRAL PLAINS LIFTS NORTHEAST ACROSS THE REGION. EXPECT WINDS
TO REALLY RAMP UP THIS AFTERNOON...WITH TO 30KT WINDS BEING OBSERVED
ACROSS ALL OF THE LAKE. ALTHOUGH NOT OVERLY CONFIDENT...DO THINK
THERE WILL BE AT LEAST GALE FORCE GUSTS ACROSS THE NEARSHORE WATERS
AND SOUTH HALF OF THE LAKE THIS AFTERNOON...AND HAVE THAT INCLUDED
IN THE FORECAST. WINDS WILL FURTHER INCREASE TONIGHT WITH HIGH END
GALES TO 45 KT EXPECTED ACROSS THE SOUTH HALF AND NEARSHORE...AND
THEN STORM FORCE WINDS TO 50KT ACROSS THE NORTH HALF. THERE WILL
BE A POSSIBILITY FOR STORM FORCE WINDS ACROSS THE SOUTH HALF AND
NEARSHORE...BUT AT THIS TIME...THIS LOOKS TO BE ONLY FOR A SMALL
WINDOW. HOWEVER...WILL NEED TO MONITOR THE POTENTIAL FOR A LONGER
PERIOD OF POSSIBLE STORM FORCE WINDS IN THOSE LOCATIONS. WINDS
WILL BEGIN TO COME DOWN ON THURSDAY...BUT WITH STORM AND GALES
HOLDING ONTO A LITTLE LONGER ON THE NORTH HALF. HAVE GALES GOING
ACROSS THE NORTH INTO THE AFTERNOON...BUT THERE IS A POSSIBILITY
THAT THEY MAY CONTINUE EVEN INTO IN THE EVENING.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-ILZ023-
ILZ032-ILZ033-ILZ039...6 PM WEDNESDAY TO 3 AM THURSDAY.
IN...WIND ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019...6 PM
WEDNESDAY TO 3 AM THURSDAY.
LM...GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...6 PM WEDNESDAY TO 9 PM WEDNESDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745...3 AM
THURSDAY TO 6 AM THURSDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 6 PM WEDNESDAY.
STORM WARNING...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-LMZ777-
LMZ779...9 PM WEDNESDAY TO 3 AM THURSDAY.
DENSE FOG ADVISORY...LMZ777-LMZ779 UNTIL 6 PM WEDNESDAY.
GALE WARNING...LMZ777-LMZ779...3 AM THURSDAY TO 9 AM THURSDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1158 AM CST WED DEC 23 2015
.SHORT TERM...(Today)
ISSUED AT 330 AM CST WED DEC 23 2015
09z/3am surface analysis shows a 986mb low over south-central Kansas
with a warm front extending eastward across Missouri into southern
Illinois. Southerly flow to the south of the front has resulted in
temperatures steadily rising into the lower 60s across Kentucky and
far southern Illinois...and well into the 50s further north across
the KILX CWA. Due to low-level warm/moist advection, widespread fog
has developed along/east of a Bloomington to Taylorville line. Do
not think dense fog will be an issue however, as surface winds have
been strong enough to provide enough mixing of the atmosphere to
keep vsbys around 1 mile at the lowest. HRRR shows the fog
persisting through early morning before gradually dissipating and
pushing further north.
Current water vapor imagery shows vigorous short-wave trough
tracking across the Oklahoma/Texas panhandles, and this feature is
already triggering widespread convection across eastern Oklahoma
into Arkansas. 4km WRF-NMM has a very good handle on the convection
and shows it tracking northeastward into central Illinois after
13/14z. Based on this forecast and current radar trends, have gone
with categorical PoPs for showers/thunder this morning. This
initial surge of convection will lift into northern Illinois toward
midday, resulting in a lull in the precip across the KILX CWA by
early afternoon. May even see a few breaks in the overcast as per
the HRRR cloud height forecast. Big question then becomes how much
convection will develop along an advancing cold front late this
afternoon into the evening. Several models suggest much of central
Illinois may only see scattered thunderstorms, with the more
concentrated area of convection further south from the I-70 corridor
southward into the Tennessee River Valley. Given robust instability
characterized by SBCAPEs of 500-1000J/kg and strong 0-6km bulk shear
of 70-80kt, have continued with categorical PoPs along/ahead of the
front this afternoon. Have also mentioned severe, as latest Day 1
outlook from SPC now places the entire area under a Slight Risk.
Aside from the storm chances, this will be a windy and extremely
warm day. Southerly winds will gust to between 35 and 40 mph,
helping push temperatures to near record levels in the middle to
upper 60s. In fact, if a few breaks do indeed develop in the
overcast, would not be surprised to see temps rise into the lower
70s in a few spots.
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 330 AM CST WED DEC 23 2015
As deep low pressure tracks from eastern Iowa this evening to Lake
Superior by midnight, impressive pressure rises will create very
strong southwesterly winds across the area this evening behind the
departing cold front. A Wind Advisory may need to be issued for
areas north of the I-70 corridor, as gusts could exceed 40 mph. Will
hold off on the advisory for now, waiting until the strong to
potentially severe convection clears the area later today.
Showers/storms will quickly exit into Indiana by midnight, with dry
weather expected overnight.
A lull in the action is still anticipated for Thursday into Friday,
with slightly cooler high temperatures in the 40s and 50s. After
that, a wet/unsettled weekend is on tap. 00z Dec 23 models are in
relatively good agreement concerning the heavy rain set-up
initially, with both the GFS and ECMWF showing widespread showers
and even a few thunderstorms for Saturday/Saturday night. Latest
GFS is beginning to look more like previous runs of the ECMWF, which
shows a northern stream short-wave pushing the main baroclinic zone
southward into the Ohio River Valley on Sunday. In fact, the latest
ECMWF now shows the front south of the Ohio River and features dry
weather across central Illinois Sunday afternoon and night. Am not
ready to go quite that far yet, although the southward trend is
definitely there. Have therefore lowered PoPs substantially across
the northern half of the CWA Sunday/Sunday night and have pushed
thunder mention further south out of the area. Closed upper low
over the Desert Southwest will eventually eject northeastward,
bringing higher PoPs back by Monday/Monday night. Rain chances will
then finally decrease by Tuesday as the low lifts into the Great
Lakes.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
ISSUED AT 1149 AM CST WED DEC 23 2015
Active convective weather with a complex weather system can be
expected in central and eastern IL this afternoon through this
evening. The majority of the area is in the warm sector of the
storm system, so ceilings have come up considerably due to this
and the high winds from the mixing of the lower atmosphere.
Several rounds of showers/t-storms will impact central and eastern
IL TAF sites through at least 20-21 UTC before the next round
approaches/develops in the 21-03 UTC timeframe. Added a TEMPO
group to not only highlight the MVFR visibility/ceilings from the
moderate to heavy rain, but also wind gusts exceeding 40 kts from
the strongest thunderstorms.
Outside of the thunderstorms, VFR conditions are anticipated.
However, an increasing pressure gradient this afternoon through
the evening will result in south to southwest winds of 25-30 kts
with gusts around 35 kts.
The sky is expected to partially clear and wind settle down a bit
after midnight local time. Increasing mid level clouds are
anticipated by mid-morning Thursday, but conditions will be VFR.
&&
.CLIMATE...
ISSUED AT 458 AM CST WED DEC 23 2015
Record highs for today:
Bloomington/Normal......... 63 in 1933
Champaign/Urbana........... 64 in 1933
Charleston/Mattoon......... 69 in 1933
Danville................... 65 in 1933
Decatur.................... 66 in 1933
Effingham.................. 68 in 1933
Jacksonville............... 70 in 1933
Lincoln.................... 65 in 1933
Olney...................... 67 in 1931
Peoria..................... 65 in 1933
Springfield................ 66 in 1933
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Miller
CLIMATE...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
551 AM CST WED DEC 23 2015
.SHORT TERM...(Today)
ISSUED AT 330 AM CST WED DEC 23 2015
09z/3am surface analysis shows a 986mb low over south-central Kansas
with a warm front extending eastward across Missouri into southern
Illinois. Southerly flow to the south of the front has resulted in
temperatures steadily rising into the lower 60s across Kentucky and
far southern Illinois...and well into the 50s further north across
the KILX CWA. Due to low-level warm/moist advection, widespread fog
has developed along/east of a Bloomington to Taylorville line. Do
not think dense fog will be an issue however, as surface winds have
been strong enough to provide enough mixing of the atmosphere to
keep vsbys around 1 mile at the lowest. HRRR shows the fog
persisting through early morning before gradually dissipating and
pushing further north.
Current water vapor imagery shows vigorous short-wave trough
tracking across the Oklahoma/Texas panhandles, and this feature is
already triggering widespread convection across eastern Oklahoma
into Arkansas. 4km WRF-NMM has a very good handle on the convection
and shows it tracking northeastward into central Illinois after
13/14z. Based on this forecast and current radar trends, have gone
with categorical PoPs for showers/thunder this morning. This
initial surge of convection will lift into northern Illinois toward
midday, resulting in a lull in the precip across the KILX CWA by
early afternoon. May even see a few breaks in the overcast as per
the HRRR cloud height forecast. Big question then becomes how much
convection will develop along an advancing cold front late this
afternoon into the evening. Several models suggest much of central
Illinois may only see scattered thunderstorms, with the more
concentrated area of convection further south from the I-70 corridor
southward into the Tennessee River Valley. Given robust instability
characterized by SBCAPEs of 500-1000J/kg and strong 0-6km bulk shear
of 70-80kt, have continued with categorical PoPs along/ahead of the
front this afternoon. Have also mentioned severe, as latest Day 1
outlook from SPC now places the entire area under a Slight Risk.
Aside from the storm chances, this will be a windy and extremely
warm day. Southerly winds will gust to between 35 and 40 mph,
helping push temperatures to near record levels in the middle to
upper 60s. In fact, if a few breaks do indeed develop in the
overcast, would not be surprised to see temps rise into the lower
70s in a few spots.
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 330 AM CST WED DEC 23 2015
As deep low pressure tracks from eastern Iowa this evening to Lake
Superior by midnight, impressive pressure rises will create very
strong southwesterly winds across the area this evening behind the
departing cold front. A Wind Advisory may need to be issued for
areas north of the I-70 corridor, as gusts could exceed 40 mph. Will
hold off on the advisory for now, waiting until the strong to
potentially severe convection clears the area later today.
Showers/storms will quickly exit into Indiana by midnight, with dry
weather expected overnight.
A lull in the action is still anticipated for Thursday into Friday,
with slightly cooler high temperatures in the 40s and 50s. After
that, a wet/unsettled weekend is on tap. 00z Dec 23 models are in
relatively good agreement concerning the heavy rain set-up
initially, with both the GFS and ECMWF showing widespread showers
and even a few thunderstorms for Saturday/Saturday night. Latest
GFS is beginning to look more like previous runs of the ECMWF, which
shows a northern stream short-wave pushing the main baroclinic zone
southward into the Ohio River Valley on Sunday. In fact, the latest
ECMWF now shows the front south of the Ohio River and features dry
weather across central Illinois Sunday afternoon and night. Am not
ready to go quite that far yet, although the southward trend is
definitely there. Have therefore lowered PoPs substantially across
the northern half of the CWA Sunday/Sunday night and have pushed
thunder mention further south out of the area. Closed upper low
over the Desert Southwest will eventually eject northeastward,
bringing higher PoPs back by Monday/Monday night. Rain chances will
then finally decrease by Tuesday as the low lifts into the Great
Lakes.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
ISSUED AT 545 AM CST WED DEC 23 2015
IFR or lower conditions will start at all TAF sites as low stratus
blankets the area at start of TAF period. Cigs are forecast to
remain IFR through the morning and into the afternoon at all
sites. Except for BMI all TAF sites have MVFR vis or better. BMI
still has 1/4sm FG, but thinking is this will gradually improve
this morning. The first batch of showers and isolated
thunderstorms will begin to move through, effecting the TAF sites
starting at 14z at PIA and SPI, and then 15z at DEC/BMI/CMI. These
conditions will continue through the late morning. Then by
afternoon, the second wave of pcpn will begin to move toward the
area and effect the TAFs. Unsure on timing, but going with 19z at
SPI and PIA, and then 20z at DEC/CMI/BMI. Will also have VCTS
since also unsure if pcpn will actually effect on station. Once
this moves through late afternoon to early evening, conditions
will improve at all sites, and then become clear after midnight.
Southeast winds will become southerly and begin to gust to near
30kts. Southerly winds will increase during the morning and into
the afternoon hours with gusts to around 35kts or little higher at
BMI and CMI. When the winds become more southwesterly after the
second wave of pcpn, wind speeds will become higher with all sites
gusting to between 37 and 38kts. Winds will decrease overnight
and become more westerly.
&&
.CLIMATE...
ISSUED AT 458 AM CST WED DEC 23 2015
Record highs for today:
Bloomington/Normal......... 63 in 1933
Champaign/Urbana........... 64 in 1933
Charleston/Mattoon......... 69 in 1933
Danville................... 65 in 1933
Decatur.................... 66 in 1933
Effingham.................. 68 in 1933
Jacksonville............... 70 in 1933
Lincoln.................... 65 in 1933
Olney...................... 67 in 1931
Peoria..................... 65 in 1933
Springfield................ 66 in 1933
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten
CLIMATE...Barnes
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
330 AM CST WED DEC 23 2015
.SHORT TERM...(Today)
ISSUED AT 330 AM CST WED DEC 23 2015
09z/3am surface analysis shows a 986mb low over south-central Kansas
with a warm front extending eastward across Missouri into southern
Illinois. Southerly flow to the south of the front has resulted in
temperatures steadily rising into the lower 60s across Kentucky and
far southern Illinois...and well into the 50s further north across
the KILX CWA. Due to low-level warm/moist advection, widespread fog
has developed along/east of a Bloomington to Taylorville line. Do
not think dense fog will be an issue however, as surface winds have
been strong enough to provide enough mixing of the atmosphere to
keep visbys around 1 mile at the lowest. HRRR shows the fog
persisting through early morning before gradually dissipating and
pushing further north.
Current water vapor imagery shows vigorous short-wave trough
tracking across the Oklahoma/Texas panhandles, and this feature is
already triggering widespread convection across eastern Oklahoma
into Arkansas. 4km WRF-NMM has a very good handle on the convection
and shows it tracking northeastward into central Illinois after
13/14z. Based on this forecast and current radar trends, have gone
with categorical PoPs for showers/thunder this morning. This
initial surge of convection will lift into northern Illinois toward
midday, resulting in a lull in the precip across the KILX CWA by
early afternoon. May even see a few breaks in the overcast as per
the HRRR cloud height forecast. Big question then becomes how much
convection will develop along an advancing cold front late this
afternoon into the evening. Several models suggest much of central
Illinois may only see scattered thunderstorms, with the more
concentrated area of convection further south from the I-70 corridor
southward into the Tennessee River Valley. Given robust instability
characterized by SBCAPEs of 500-1000J/kg and strong 0-6km bulk shear
of 70-80kt, have continued with categorical PoPs along/ahead of the
front this afternoon. Have also mentioned severe, as latest Day 1
outlook from SPC now places the entire area under a Slight Risk.
Aside from the storm chances, this will be a windy and extremely
warm day. Southerly winds will gust to between 35 and 40 mph,
helping push temperatures to near record levels in the middle to
upper 60s. In fact, if a few breaks do indeed develop in the
overcast, would not be surprised to see temps rise into the lower
70s in a few spots.
&&
.LONG TERM...(Tonight through Tuesday)
ISSUED AT 330 AM CST WED DEC 23 2015
As deep low pressure tracks from eastern Iowa this evening to Lake
Superior by midnight, impressive pressure rises will create very
strong southwesterly winds across the area this evening behind the
departing cold front. A Wind Advisory may need to be issued for
areas north of the I-70 corridor, as gusts could exceed 40 mph. Will
hold off on the advisory for now, waiting until the strong to
potentially severe convection clears the area later today.
Showers/storms will quickly exit into Indiana by midnight, with dry
weather expected overnight.
A lull in the action is still anticipated for Thursday into Friday,
with slightly cooler high temperatures in the 40s and 50s. After
that, a wet/unsettled weekend is on tap. 00z Dec 23 models are in
relatively good agreement concerning the heavy rain set-up
initially, with both the GFS and ECMWF showing widespread showers
and even a few thunderstorms for Saturday/Saturday night. Latest
GFS is beginning to look more like previous runs of the ECMWF, which
shows a northern stream short-wave pushing the main baroclinic zone
southward into the Ohio River Valley on Sunday. In fact, the latest
ECMWF now shows the front south of the Ohio River and features dry
weather across central Illinois Sunday afternoon and night. Am not
ready to go quite that far yet, although the southward trend is
definitely there. Have therefore lowered PoPs substantially across
the northern half of the CWA Sunday/Sunday night and have pushed
thunder mention further south out of the area. Closed upper low
over the Desert Southwest will eventually eject northeastward,
bringing higher PoPs back by Monday/Monday night. Rain chances will
then finally decrease by Tuesday as the low lifts into the Great
Lakes.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
ISSUED AT 1055 PM CST TUE DEC 22 2015
IFR to LIFR conditions are expected to continue into the early
afternoon hours of Wednesday as a strong storm system passes
across the area Wednesday evening. Widespread stratus clouds
and areas of fog have expanded north into the forecast area
this evening and expect that to hold tonight as southerly
winds draw an increasing amount of low level moisture northward
into our area ahead of the storm. Rain will spread northeast into
central Illinois after midnight and encompass most of our area
during the morning and early afternoon hours before a warm front
shifts north out of our area by late afternoon. Once that occurs,
we may see a temporary improvement in cigs and vsbys with the
rain coming to a temporary end. A cold front will then surge
east across the area Wed evening in the 23z-03z time frame with
scattered TSRA possible along the front. Strong gradient winds
are expected to develop over the area later Wednesday morning
and continue into the evening hours before shifting into the
southwest and west after 22z at SPI and PIA, and by 03z in
CMI.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
327 PM EST TUE DEC 22 2015
.UPDATE...
THE LONG TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 256 PM EST TUE DEC 22 2015
PATTERN TO REMAIN MILD THROUGH AND BEYOND THE SEVEN DAY FORECAST.
A COUPLE OF SIGNIFICANT STORMS SYSTEMS...WEDNESDAY WITH POTENTIAL
DAMAGING WIND...AND THIS WEEKEND...WITH HEAVY RAIN THAT MAY LEAD
TO FLOODING...WILL FINISH OUT THE ACTIVE WEATHER PATTERN LATE THIS
YEAR.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1002 PM EST TUE DEC 22 2015
AFTER SOME SUNSHINE FOR MOST LATE THIS AFTERNOON...LOWER STRATUS
HAS ADVECTED BACK ACROSS MOST OF THE FORECAST AREA AS OF 03Z WITH
MOISTURE STREAMING NORTH AND INTERACTING WITH THE SHALLOW
INVERSION STILL PRESENT. FAR NORTHERN COUNTIES HAVE MANAGED TO
DROP QUICKLY INTO THE MID AND UPPER 30S THIS EVENING WHERE SKIES
HAVE REMAINED CLEAR THE LONGEST...WITH TEMPS RANGING FROM THE MID
40S TO LOWER 50S OVER MOST OF THE REST OF THE FORECAST AREA.
PIECES ALREADY STARTING TO ALIGN THAT WILL BRING THE WARM
TEMPERATURES WEDNESDAY ALONG WITH THE UNUSUAL SEVERE WEATHER RISK
FOR THE AFTERNOON AND EVENING WEDNESDAY. POLEWARD MOISTURE RETURN
OVER THE LAST 6 HOURS FROM THE GULF COAST HAS BEEN IMPRESSIVE TO
OUR SOUTH TO PUT IT MILDLY. 60+ DEGREE DEWPOINTS NOW WELL INTO THE
TENNESSEE VALLEY AND WILL LIKELY ADVANCE INTO KENTUCKY AFTER
MIDNIGHT. ALREADY SEEING PATCHY FOG IN THE LOWER WABASH VALLEY AS
THE DEEPER MOISTURE ARRIVES AND EXPECT THAT TO CONTINUE OVERNIGHT
IN SOME AREAS.
LOWS HAVE ALREADY BEEN MET...WITH TEMPERATURES STEADILY
CLIMBING FOR THE REST OF THE NIGHT AS WARM MOIST AIR SPREADS
NORTH. RAP AND NAM BOTH HINTING AT SURFACE TEMPS NEAR 60 OVER
SOUTHERN FORECAST AREA BY DAYBREAK AND CONSIDERING CURRENT TEMPS
OVER THE TENNESSEE AND LOWER MISSISSIPPI VALLEYS...THAT DOES NOT
SEEM FAR OFF.
CONVECTION ACROSS THE LOWER MISSISSIPPI VALLEY WILL RACE NORTHEAST
OVERNIGHT AND WHILE BULK OF THE ACTIVITY SHOULD REMAIN TO THE
SOUTHEAST OF THE FORECAST AREA...HI-RES GUIDANCE CONTINUING TO
CAPTURE SCATTERED SHOWERS INCREASING IN COVERAGE AFTER 06Z FROM
THE SOUTH AS WARM ADVECTION INTENSIFIES OVER THE OHIO VALLEY.
HAVE ADJUSTED POPS SLIGHTLY...BUT INTRODUCING LOW CHANCES FOR
ENTIRE FORECAST AREA FOR THE PREDAWN HOURS. MEANWHILE BACK TO THE
SOUTHWEST...EXPECT RAPID CONVECTIVE DEVELOPMENT OVER THE OZARKS AS
THE INTENSE LOW PRESSURE SWINGS OUT THROUGH THE CENTRAL PLAINS AND
BEGINS TO INTERACT WITH THE GULF MOISTURE FETCH. THIS WILL
CONTINUE TO INCREASE IN COVERAGE AND EXPAND INTO THE REGION BY MID
TO LATE MORNING WEDNESDAY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 256 PM EST TUE DEC 22 2015
FORECAST ISSUE IS SEVERE WEATHER THREAT WEDNESDAY. THOUGH MODEL
DYNAMICS IN FAIRLY GOOD AGREEMENT...AMOUNT OF DESTABILIZATION
PRIOR TO MAIN SHOWER/SQUALL BAND ARRIVAL IN THE AFTERNOON MAY
DETERMINE HOW GUSTY CONVECTION MAY GET. MODEL SOUNDINGS SUGGEST
MIXING OF 40MPH GUSTS TO THE GROUND PRIOR TO ANY STORM LINE MAY
OCCUR AS WELL SO HAVE INCLUDED GUSTY WORDING IN THE FORECAST.
NAM SOMEWHAT DIFFERENT THAN OTHER MODELS IN HAVING QUITE DISTINCT
AND SIMILARLY POTENT ROUNDS OF STORMS...AFTERNOON AND THEN EVENING
WITH COLD FRONT TIED WITH TWO INSTABILITY AXES. WILL LEAN TOWARD
A BLEND OF MODELS AND FORECAST WORDING MAY NOT REFLECT THE
SEPARATION BUT TWO HEAVIER ROUNDS OF RAIN APPEAR POSSIBLE.
STRENGTH OF WARM ADVECTION SHOULD LEAD TO ADVERTISED RECORD OR
NEAR RECORD HIGHS IN THE UPPER 60S WEDNESDAY.
WEDNESDAY NIGHT...NAM IS SLOWEST WITH COLD FRONT WHILE GFS IS
QUITE FAST SO WILL AVERAGE BETWEEN THESE. END RESULT IS AT LEAST
ONE MORE DECENT SHOT OF RAIN WITH COLD FRONT PASSAGE DURING THE
EVENING WITH LINGERING SHOWERS ENDING BEFORE DAYBREAK.
THURSDAY AND PART OF FRIDAY...A DRY TRANQUIL PERIOD IS IN STORE
AS HIGH PRESSURE BUILDS IN BEHIND THE INTENSIFYING LOW THAT LIFTS
NE INTO THE HUDSON BAY AREA. HAVE KEPT TEMPERATURES NEAR GUIDANCE
AND STILL WELL ABOVE NORMAL WITH HIGHS MAINLY IN THE 50S AND LOWS
ABOVE FREEZING.
AS THE NEXT STRONG SHORTWAVE DUMPS INTO THE WESTERN TROUGH...THE
SURFACE BOUNDARY THAT SLIPPED INTO KENTUCKY THURSDAY WILL LIFT
BACK NORTH TO BEGIN THE NEXT RAINY PERIOD.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
ISSUED AT 342 AM EST WED DEC 23 2015
MODELS CONTINUE TO ADVERTISE AN EXTREMELY STRONG BAROCLINIC ZONE IN
PLACE ACROSS THE REGION OVER THE WEEKEND AND INTO EARLY NEXT
WEEK...WITH POTENTIAL FOR SIGNIFICANT MOISTURE ADVECTION INTO THE
FRONTAL ZONE ON A PERSISTENT 40 TO 50 KT LOW LEVEL JET THROUGHOUT
THE WEEKEND. THIS WOULD SET THE STAGE FOR MULTIPLE ROUNDS OF
POTENTIALLY HEAVY RAINFALL. EVEN WITH MODEL TENDENCIES TO BE OVERLY
AGGRESSIVE WITH MOISTURE TRANSPORT...MODEL PRECIPITABLE WATER VALUES
WOULD BE EXTREMELY ANOMALOUSLY HIGH CLIMATOLOGICALLY SPEAKING...99TH
PERCENTILE OR GREATER...NEARING THE MAXIMUM EXPECTED VALUE FOR THE
TIME OF YEAR.
INSTABILITY INDICES SUGGEST AT LEAST A CHANCE OF THUNDER IS MERITED
ACROSS AT LEAST SOME PORTION OF CENTRAL INDIANA SATURDAY THROUGH
MONDAY.
MODEL BLENDED FORECASTS SHOW POTENTIAL FOR 3 TO 5 INCHES OF RAINFALL
DURING THE HOLIDAY WEEKEND...WITH AREAS OF 5 PLUS POSSIBLE. THIS
COULD BE HEAVILY IMPACTED BY THE POSITION OF THE FRONTAL ZONE...AND
SIGNIFICANT UNCERTAINTY REMAINS WITH REGARD TO THAT.
NONETHELESS...EVEN WITH THE AREA HAVING BEEN BELOW NORMAL ON
PRECIPITATION FOR THE LAST 5 MONTHS OR SO...THE DECREASED ACTIVITY
OF VEGETATION DURING THE COOL SEASON...ALONG WITH THE POTENTIAL
DURATION AND INTENSITY OF RAINFALL WILL PRESENT A POTENTIALLY
SIGNIFICANT FLOOD THREAT ACROSS THE REGION.
&&
.AVIATION /DISCUSSION FOR THE 23/09Z TAF UPDATE/...
ISSUED AT 342 AM EST WED DEC 23 2015
IFR CONDITIONS WORSENING ACROSS THE AREA. AMENDED TO BRING TAFS IN
LINE WITH OBS. PREVIOUS DISCUSSION FOLLOWS.
ISSUED AT 1132 PM EST TUE DEC 22 2015
SOME DRIER AIR WORKING ITS WAY IN FROM THE SOUTHEAST HAS SCATTERED OUT
SOME OF THE LOW CEILINGS THAT HAVE BEEN AFFECTING THE TERMINALS DURING
PARTS OF THE EVENING HOURS. THIS SHOULD BE TEMPORARY...AS WARM/MOIST
ADVECTION OVERRUNNING AN APPROACHING WARM FRONT SHOULD ALLOW FOR IFR
CONDITIONS TO DEVELOP AGAIN OVER THE NEXT SEVERAL HOURS. WILL KEEP IFR
CEILINGS IN THE FORECAST UNTIL THE MID TO LATE MORNING HOURS OF WEDNESDAY
WHEN THE BOUNDARY LAYER SHOULD MIX OUT ENOUGH TO ALLOW THE CEILINGS TO LIFT
INTO THE MVFR CATEGORY.
MODEL DATA SUGGEST INITIAL BAND OF ORGANIZED LIFT WILL BE MOVING INTO THE
WESTERN PARTS OF THE STATE TOWARDS 231700Z...SO EXPECTING RAIN/EMBEDDED
THUNDERSTORMS TO BEGIN AFFECTING THE TERMINALS FROM THE WEST TOWARDS MIDDAY
AND ON INTO THE AFTERNOON HOURS. RAINFALL MAY BE HEAVY ENOUGH FOR PERIODS OF
IFR VISIBILITY RESTRICTIONS.
SURFACE WINDS OVERNIGHT 130-160 DEGREES AT 6-9 KTS. PRESSURE GRADIENT REALLY
TIGHTENS UP BY MIDDAY WEDNESDAY IN THE WARM SECTOR...WITH SURFACE GUSTS AROUND
30 KTS PROBABLE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TUCEK
NEAR TERM...RYAN
SHORT TERM...TUCEK
LONG TERM...NIELD
AVIATION...JAS/NIELD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1132 PM EST TUE DEC 22 2015
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 256 PM EST TUE DEC 22 2015
PATTERN TO REMAIN MILD THROUGH AND BEYOND THE SEVEN DAY FORECAST.
A COUPLE OF SIGNIFICANT STORMS SYSTEMS...WEDNESDAY WITH POTENTIAL
DAMAGING WIND...AND THIS WEEKEND...WITH HEAVY RAIN THAT MAY LEAD
TO FLOODING...WILL FINISH OUT THE ACTIVE WEATHER PATTERN LATE THIS
YEAR.
&&
.NEAR TERM /REST OF TONIGHT/...
ISSUED AT 1002 PM EST TUE DEC 22 2015
AFTER SOME SUNSHINE FOR MOST LATE THIS AFTERNOON...LOWER STRATUS
HAS ADVECTED BACK ACROSS MOST OF THE FORECAST AREA AS OF 03Z WITH
MOISTURE STREAMING NORTH AND INTERACTING WITH THE SHALLOW
INVERSION STILL PRESENT. FAR NORTHERN COUNTIES HAVE MANAGED TO
DROP QUICKLY INTO THE MID AND UPPER 30S THIS EVENING WHERE SKIES
HAVE REMAINED CLEAR THE LONGEST...WITH TEMPS RANGING FROM THE MID
40S TO LOWER 50S OVER MOST OF THE REST OF THE FORECAST AREA.
PIECES ALREADY STARTING TO ALIGN THAT WILL BRING THE WARM
TEMPERATURES WEDNESDAY ALONG WITH THE UNUSUAL SEVERE WEATHER RISK
FOR THE AFTERNOON AND EVENING WEDNESDAY. POLEWARD MOISTURE RETURN
OVER THE LAST 6 HOURS FROM THE GULF COAST HAS BEEN IMPRESSIVE TO
OUR SOUTH TO PUT IT MILDLY. 60+ DEGREE DEWPOINTS NOW WELL INTO THE
TENNESSEE VALLEY AND WILL LIKELY ADVANCE INTO KENTUCKY AFTER
MIDNIGHT. ALREADY SEEING PATCHY FOG IN THE LOWER WABASH VALLEY AS
THE DEEPER MOISTURE ARRIVES AND EXPECT THAT TO CONTINUE OVERNIGHT
IN SOME AREAS.
LOWS HAVE ALREADY BEEN MET...WITH TEMPERATURES STEADILY
CLIMBING FOR THE REST OF THE NIGHT AS WARM MOIST AIR SPREADS
NORTH. RAP AND NAM BOTH HINTING AT SURFACE TEMPS NEAR 60 OVER
SOUTHERN FORECAST AREA BY DAYBREAK AND CONSIDERING CURRENT TEMPS
OVER THE TENNESSEE AND LOWER MISSISSIPPI VALLEYS...THAT DOES NOT
SEEM FAR OFF.
CONVECTION ACROSS THE LOWER MISSISSIPPI VALLEY WILL RACE NORTHEAST
OVERNIGHT AND WHILE BULK OF THE ACTIVITY SHOULD REMAIN TO THE
SOUTHEAST OF THE FORECAST AREA...HI-RES GUIDANCE CONTINUING TO
CAPTURE SCATTERED SHOWERS INCREASING IN COVERAGE AFTER 06Z FROM
THE SOUTH AS WARM ADVECTION INTENSIFIES OVER THE OHIO VALLEY.
HAVE ADJUSTED POPS SLIGHTLY...BUT INTRODUCING LOW CHANCES FOR
ENTIRE FORECAST AREA FOR THE PREDAWN HOURS. MEANWHILE BACK TO THE
SOUTHWEST...EXPECT RAPID CONVECTIVE DEVELOPMENT OVER THE OZARKS AS
THE INTENSE LOW PRESSURE SWINGS OUT THROUGH THE CENTRAL PLAINS AND
BEGINS TO INTERACT WITH THE GULF MOISTURE FETCH. THIS WILL
CONTINUE TO INCREASE IN COVERAGE AND EXPAND INTO THE REGION BY MID
TO LATE MORNING WEDNESDAY.
ZONE AND GRID UPDATES OUT.
&&
.SHORT TERM /WEDNESDAY THROUGH FRIDAY/...
ISSUED AT 256 PM EST TUE DEC 22 2015
FORECAST ISSUE IS SEVERE WEATHER THREAT WEDNESDAY. THOUGH MODEL
DYNAMICS IN FAIRLY GOOD AGREEMENT...AMOUNT OF DESTABILIZATION
PRIOR TO MAIN SHOWER/SQUALL BAND ARRIVAL IN THE AFTERNOON MAY
DETERMINE HOW GUSTY CONVECTION MAY GET. MODEL SOUNDINGS SUGGEST
MIXING OF 40MPH GUSTS TO THE GROUND PRIOR TO ANY STORM LINE MAY
OCCUR AS WELL SO HAVE INCLUDED GUSTY WORDING IN THE FORECAST.
NAM SOMEWHAT DIFFERENT THAN OTHER MODELS IN HAVING QUITE DISTINCT
AND SIMILARLY POTENT ROUNDS OF STORMS...AFTERNOON AND THEN EVENING
WITH COLD FRONT TIED WITH TWO INSTABILITY AXES. WILL LEAN TOWARD
A BLEND OF MODELS AND FORECAST WORDING MAY NOT REFLECT THE
SEPARATION BUT TWO HEAVIER ROUNDS OF RAIN APPEAR POSSIBLE.
STRENGTH OF WARM ADVECTION SHOULD LEAD TO ADVERTISED RECORD OR
NEAR RECORD HIGHS IN THE UPPER 60S WEDNESDAY.
WEDNESDAY NIGHT...NAM IS SLOWEST WITH COLD FRONT WHILE GFS IS
QUITE FAST SO WILL AVERAGE BETWEEN THESE. END RESULT IS AT LEAST
ONE MORE DECENT SHOT OF RAIN WITH COLD FRONT PASSAGE DURING THE
EVENING WITH LINGERING SHOWERS ENDING BEFORE DAYBREAK.
THURSDAY AND PART OF FRIDAY...A DRY TRANQUIL PERIOD IS IN STORE
AS HIGH PRESSURE BUILDS IN BEHIND THE INTENSIFYING LOW THAT LIFTS
NE INTO THE HUDSON BAY AREA. HAVE KEPT TEMPERATURES NEAR GUIDANCE
AND STILL WELL ABOVE NORMAL WITH HIGHS MAINLY IN THE 50S AND LOWS
ABOVE FREEZING.
AS THE NEXT STRONG SHORTWAVE DUMPS INTO THE WESTERN TROUGH...THE
SURFACE BOUNDARY THAT SLIPPED INTO KENTUCKY THURSDAY WILL LIFT
BACK NORTH TO BEGIN THE NEXT RAINY PERIOD.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
ISSUED AT 232 PM EST TUE DEC 22 2015
ECMWF CONTINUES TO SUGGEST STRONG SOUTHWEST FLOW ALOFT OVER THE
EASTERN HALF OF THE UNITED STATES DURING THIS PERIOD...WITH MILD AND
MOIST GULF AIR FLOWING NORTH INTO THE OHIO VALLEY. A DEEP LOW
DEVELOPING OVER THE AMERICAN SOUTHWEST WILL GRADUALLY PUSH EAST
INTO TEXAS DURING THIS PERIOD...OCCASIONAL EJECTING WEAK SHORT
WAVES INTO THE SW FLOW ALOFT TOWARD THE OHIO VALLEY THROUGH
TUESDAY. MEANWHILE IN THE LOWER LEVELS A FRONTAL BOUNDARY IS
EXPECTED TO LINGER ACROSS CENTRAL INDIANA AND THE OHIO VALLEY
THROUGH MUCH OF THE PERIOD...PROVIDING A FOCUS FOR LOWER LEVEL
CONVERGENCE AND PRECIPITATION. THUS WILL AGAIN CONTINUE THE
ONGOING FORECAST THROUGH THE PERIOD WITH PLENTY OF POPS AND ABOVE
NORMAL TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 230600Z TAFS/...
ISSUED AT 1132 PM EST TUE DEC 22 2015
SOME DRIER AIR WORKING ITS WAY IN FROM THE SOUTHEAST HAS SCATTERED OUT
SOME OF THE LOW CEILINGS THAT HAVE BEEN AFFECTING THE TERMINALS DURING
PARTS OF THE EVENING HOURS. THIS SHOULD BE TEMPORARY...AS WARM/MOIST
ADVECTION OVERRUNNING AN APPROACHING WARM FRONT SHOULD ALLOW FOR IFR
CONDITIONS TO DEVELOP AGAIN OVER THE NEXT SEVERAL HOURS. WILL KEEP IFR
CEILINGS IN THE FORECAST UNTIL THE MID TO LATE MORNING HOURS OF WEDNESDAY
WHEN THE BOUNDARY LAYER SHOULD MIX OUT ENOUGH TO ALLOW THE CEILINGS TO LIFT
INTO THE MVFR CATEGORY.
MODEL DATA SUGGEST INITIAL BAND OF ORGANIZED LIFT WILL BE MOVING INTO THE
WESTERN PARTS OF THE STATE TOWARDS 231700Z...SO EXPECTING RAIN/EMBEDDED
THUNDERSTORMS TO BEGIN AFFECTING THE TERMINALS FROM THE WEST TOWARDS MIDDAY
AND ON INTO THE AFTERNOON HOURS. RAINFALL MAY BE HEAVY ENOUGH FOR PERIODS OF
IFR VISIBILITY RESTRICTIONS.
SURFACE WINDS OVERNIGHT 130-160 DEGREES AT 6-9 KTS. PRESSURE GRADIENT REALLY
TIGHTENS UP BY MIDDAY WEDNESDAY IN THE WARM SECTOR...WITH SURFACE GUSTS AROUND
30 KTS PROBABLE.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TUCEK
NEAR TERM...RYAN
SHORT TERM...TUCEK
LONG TERM....PUMA
AVIATION...JAS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1147 AM CST WED DEC 23 2015
.SHORT TERM /TODAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
MORNING WATER VAPOR IMAGERY DEPICTS A SEASONABLY STRONG NEGATIVELY
TILTED LONGWAVE TROUGH AXIS SITUATED DOWN THE EASTERN FLANK OF THE
ROCKIES WITH A 150 KT JET IMPINGING ALONG ITS SOUTHWEST FLANK. AN
EMBEDDED SHORTWAVE/PV ANOMALY WILL EJECT NORTHEASTWARD FROM THE BASE
OF THE TROUGH TO THE SOUTHERN MISSOURI RIVER VALLEY BY 00Z THIS
EVENING. A DEEPENING 986 MB SURFACE CYCLONE OVER THE OKLAHOMA
PANHANDLE WILL LIKEWISE LIFT NORTHEASTWARD OVER THE COURSE OF THE
DAY AND BE SITUATED NEAR PRAIRIE DU CHIEN BY 00Z TONIGHT USING THE
GFS SOLUTION...WHICH IS HANDLING THE DEEPENING EVOLUTION OF THE LOW
THE BEST THIS MORNING. THIS WILL BRING A WIDE VARIETY OF WEATHER
ACROSS CENTRAL IOWA TODAY.
STARTING OUT THIS MORNING...A BROAD WARM FRONT CURRENTLY STRETCHES
FROM NEAR OMAHA TO DUBUQUE...WITH TEMPERATURES IN THE MID 30S NORTH
OF THE BOUNDARY TO MID 40S SOUTH. THIS BOUNDARY WILL TIGHTEN DURING
THE COURSE OF THE DAY AS THE LOW APPROACHES...WITH HIGHS RANGING
FROM THE MID 30S NORTHWEST TO NEAR 60 IN THE SOUTHEAST. AS THE LOW
BEGINS TO PULL EASTWARD AFTER 18Z...THIS WILL LIKEWISE PULL THE
BOUNDARY EASTWARD AS A COLD FRONT THIS AFTERNOON AND EVENING.
WIDESPREAD RAIN IS EXPANDING ACROSS THE AREA NOW AS STRONG MIDLEVEL
KINEMATIC/290-300 K ISENTROPIC FORCING INTENSIFIES. INITIAL BOUT OF
PRECIP EARLIER IN THE NIGHT TIED IN WITH A REGION OF THETA-E
ADVECTION HAD TO FIGHT A SUB 800 MB DRY LAYER...BUT THE COLUMN IS
RAPIDLY SATURATING AND PRECIP IS BEING REPORTED AT MULTIPLE SITES.
BEST MIDLEVEL FORCING AND DEEPEST MOISTURE WILL BE COINCIDENT IN THE
15-21Z TIMEFRAME AND HAVE KEPT THE MAX QPF AMOUNTS DURING THIS
WINDOW. PWATS OF 0.50 TO 0.75 INCHES ARE 2 TO 3 STANDARD DEVIATIONS
ABOVE NORMAL AND DAILY TOTAL RAINFALL AMOUNTS OF 0.50 TO 0.75 INCHES
ARE POSSIBLE. THIS WIDESPREAD RAIN WILL LEAD TO RISES IN AREA RIVERS
WHICH HAVE STILL NOT FULLY RECOVERED FROM THE RECORD SETTING DELUGE
A WEEK AND A HALF AGO.
AS THE UPPER LEVEL WAVE MATURES A DRY SLOT WILL WRAP NORTHWARD
ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE STATE BETWEEN 18 AND
00Z. CURRENT POP AND QPF GRIDS MAY BE A LITTLE CONSERVATIVE ON THE
TIMING OF THIS DRY SLOT OVER SOUTHERN IOWA...BUT GIVEN THE SLOWER
TRENDS OF RECENT MODEL RUNS...HAVE KEPT CATEGORICAL POPS OVER THE
SOUTH UNTIL 16-17Z. THIS DRY SLOT WILL ALSO RESULT IN STEEPENING MID
LEVEL LAPSE RATES AND INCREASING INSTABILITY OVER THE SOUTHEASTERN
PORTION OF THE CWA. RAP BUFR SOUNDINGS FROM OTTUMWA SHOW 300-500
J/KG OF MUCAPE DEVELOPING BETWEEN 18-20Z. 0-6 KM SHEAR VALUES OF 40
TO 50 KTS WILL BE MORE THAN CAPABLE OF MAINTAINING ANY THUNDERSTORMS
THAT DO DEVELOP IN THE WARM SECTOR EARLY THIS AFTERNOON. THE THREAT
FOR ORGANIZED AND SEVERE CONVECTION WILL BE CONFINED TO A VERY
NARROW AND CONDITIONAL WINDOW ACROSS THE FAR SOUTHEAST...AND WITH
STORM MOTIONS OF 40 TO 50 KTS TO THE NORTHEAST...THESE STORMS WILL
RAPIDLY EXIT THE CWA. THE MAIN THREAT WOULD BE LARGE HAIL GIVEN THE
LOW FREEZING LEVELS...BUT IF SOMEHOW ANY SOLAR INSOLATION WERE TO
TAKE PLACE AND THE STORMS DID GO SURFACE BASED...THE 35 KTS OF 0-1
KM SHEAR AND PROXIMITY TO THE SURFACE LOW WOULD SUPPORT TORNADOES.
AGAIN...THE THREAT FOR ANY SEVERE WEATHER...LET ALONE TORNADOES...IS
VERY CONDITIONAL AND LIMITED TO A SHORT WINDOW FROM AROUND 19-22Z.
NEXT ON THE DOCKET ARE WINDS ON THE BACKSIDE OF THE LOW. A
TIGHTENING PRESSURE GRADIENT AND STRONG PRESSURE RISE COUPLET
IMMEDIATELY FOLLOWING THE LOW WILL RESULT IN WINDS OF 20 TO 25 KTS
SUSTAINED WITH GUSTS OF 30 TO 35 KTS ACROSS SOUTHERN IOWA THROUGH
THE LATE AFTERNOON AND EVENING HOURS. DEFORMATION ZONE AND ELEVATED
FG ZONE WILL LINGER ACROSS THE WESTERN PORTIONS OF THE CWA AS THE
FRONTAL BOUNDARY SLIDES EASTWARD. PRECIP IN THIS ZONE WILL CHANGE
OVER TO SNOW DURING THE COURSE OF THE AFTERNOON AS COOLER AIR MOVES
IN...BUT KEPT SNOW AMOUNTS AROUND A HALF INCH OR LESS GIVEN THE LACK
OF ANY STRONG CAA AND NEAR SURFACE TEMPS STILL IN THE LOW TO MID
30S. ROADS WILL LIKELY JUST STAY WET WITH ACCUMULATIONS ON GRASSY
AREAS.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
THE PATTERN WILL BE QUITE ACTIVE THROUGH THE ENTIRE PERIOD...WITH
SOME TRAVEL IMPACTS EXPECTED DURING THE EXTENDED...BUT CONFIDENCE
IN DETAILS REMAINS LOW FOR A MULTITUDE OF REASONS. AT ONSET EXPECT
A FRONTOGENETICALLY FORCED DEFORMATION ZONE WITH DEEP VERTICAL
MOTION TO BE QUICKLY RETREATING TO THE NORTH AND EAST EARLY IN THE
EVENING. CONFIDENCE IN SNOW ACCUMS HAS INCREASED...AND DENDRITIC
GROWTH ZONE LIFT WILL BE QUITE STRONG FOR A PERIOD...BUT IT WILL
BE VERY BRIEF AND TRANSIENT. TOTAL ACCUMS WILL GENERALLY BE AN
INCH OR LESS NORTH AND WEST...BUT TOTALS MAY VARY A BIT IN EITHER
DIRECTION DUE TO MELTING ON PAVEMENT VS VEGETATION AND LOCALIZED
HIGHER RATES. ANYTHING TOWARD THE INCH RANGE WOULD BE FAR NORTH.
STRONG SUBSIDENCE WILL THEN SET IN BY NIGHT. MIXING WILL BE FAIRLY
SHALLOW BUT MSLP GRADIENT MAY STILL ALLOW FOR GUSTS TO REACH 35
MPH OR SO THROUGH AT LEAST MIDNIGHT NE.
SHORT WAVE RIDING STRONG NRN CA/OR JET WILL THEN REACH THE MO VALLEY
THU. FORCING AND MOISTURE EXTENT WILL BE QUITE VARIABLE...NEVER
REALLY APPROACHING SATURATION. THIS WILL RESULT IN ANY AMOUNTS
BEING QUITE LIGHT...AND PTYPE IN QUESTION DUE TO ONLY A SMALL
WINDOW OF ICE INTRODUCTION. THUS HAVE LOW CHANCES WITH BOTH LIGHT
SNOW OR FLURRIES...AND LIGHT FREEZING RAIN/SPRINKLES POSSIBLE.
SHOULD SEE A BRIEF BREAK IN PRECIP THU NIGHT BEFORE SHORT WAVES
REACH CA AND CONTINUE TO CARVE OUT WRN CONUS LONG WAVE TROUGH...AND
EVENTUAL CUTOFF. THIS SETS UP A PROLONGED PERIOD OF SWLY FLOW
ALOFT...AND INVERTED TROUGHINESS INTO THE MID MS VALLEY. AS THE
CLOSED LOW FORMS IN THE SW...A SHORT WAVE WILL SPLIT AND RIDE THE SW
FLOW INTO THE MO VALLEY EARLY IN THE WEEKEND. PRECIP CHANCES WILL
INCREASE SHARPLY FRI INTO FRI NIGHT. ALTHOUGH THE DEEPEST QG FORCING
WILL REMAIN JUST TO OUR NORTH AND WEST...THE H85/H7 FORCING IS
EXTREME WITH HIGH CONTRIBUTIONS FROM THETA-E ADVECTION AND
FRONTOGENESIS. SNOWFALL RATES OVER NRN IA MAY BRIEFLY BE QUITE HIGH
WITH LOW STABILITY. GFS TICKS OFF SOME MUCAPES AND...ALTHOUGH
FAIRLY ELEVATED...ALSO SHOWS NEGATIVE SAT EPV WHICH WOULD BE
EXPECTED WITH THE LOW STATIC STABILITY AND MUCAPE REFLECTION. THUS
HAVE AN INCH OR TWO OF SNOW ACCUMS POSSIBLE NORTH THROUGH 12Z SAT
WITH ADDITIONAL AMOUNTS POSSIBLE AFTER THAT TIME. THE WAVE THEN
MOVES AWAY LATER SAT WITH THE ATTENTION TURNING TOWARD THE
APPROACHING CUTOFF LOW. SOME POPS LINGER THROUGH THE
WEEKEND...ESPECIALLY SOUTH...BUT NEITHER THE FORCING OR MOISTURE
IS TOO IMPRESSIVE.
THE PROGRESSION OF THE CUTOFF LOW WILL LIKELY RESULT IN THE BIGGEST
TRAVEL IMPACT OF THE HOLIDAY TRAVEL SEASON...BUT DETAILS ARE FAR
FROM CLEAR CUT. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH ITS
FARTHER WEST AND LESS SNOWY TRACK...BUT VARIABLE IN TIME OVER
RECENT RUNS. THE GFS TRACK AND TIMING HAVE BEEN MORE
CONSISTENT...AND POINT TOWARD A WIND BLOW HEAVY SNOW EVENT...BUT
IS A FASTER OUTLIER VS THE SLOWER CANADIAN AND ECMWF. RATHER THAN
FOCUSING ON THE DETAILS THE MAIN TAKE HOME POINT FOR NOW WOULD
APPEAR TO BE A SIGNIFICANT SYSTEM WILL AFFECT HOLIDAY TRAVEL IN OR
NEAR IA SOMETIME AROUND MON OR MON NIGHT. FOR THE TIME BEING HAVE
EITHER RAIN OR SNOW IN THE FORECAST WITH LOW CONFIDENCE...BUT THE
ECMWF ALSO HINTS AT THE POSSIBILITY OF A FREEZING RAIN/ICING EVENT
NRN HALF WITH A NICE ELEVATED WARM LAYER ABOVE SUB FREEZING
SURFACE TEMPS AND A BRISK ELY WIND. WILL NEED TO CONTINUE TO
MONITOR FOR THE POTENTIAL FOR EITHER ICING OR SNOW. WHATEVER
OCCURS LOOKS TO BE GONE BY TUE NIGHT EVEN WITH THE SLOWER ECMWF
SOLUTION.
&&
.AVIATION...23/18Z
ISSUED AT 1147 AM CST WED DEC 23 2015
LOW PRESSURE WILL LIFT NE ACROSS TAF LOCATIONS. TAF LOCATIONS WILL
REMAIN IFR DUE TO CIGS AND VSBYS IN FOG. INSTABILITY WILL LIFT
ACROSS THE SE AND FAR E BRINGING A BRIEF WINDOW FOR TSRA ACROSS
THOSE LOCATIONS. SNOW POSSIBLE BRIEFLY ON THE BACK SIDE OF THE LOW
AFFECTING KFOD AND KMCW. AS THE LOW PULLS OUT AFT 22Z...WINDS WILL
INCREASE TO 20G28KTS AND BECOME WRLY.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...SMALL
AVIATION...FAB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
543 AM CST WED DEC 23 2015
.SHORT TERM /TODAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
MORNING WATER VAPOR IMAGERY DEPICTS A SEASONABLY STRONG NEGATIVELY
TILTED LONGWAVE TROUGH AXIS SITUATED DOWN THE EASTERN FLANK OF THE
ROCKIES WITH A 150 KT JET IMPINGING ALONG ITS SOUTHWEST FLANK. AN
EMBEDDED SHORTWAVE/PV ANOMALY WILL EJECT NORTHEASTWARD FROM THE BASE
OF THE TROUGH TO THE SOUTHERN MISSOURI RIVER VALLEY BY 00Z THIS
EVENING. A DEEPENING 986 MB SURFACE CYCLONE OVER THE OKLAHOMA
PANHANDLE WILL LIKEWISE LIFT NORTHEASTWARD OVER THE COURSE OF THE
DAY AND BE SITUATED NEAR PRAIRIE DU CHIEN BY 00Z TONIGHT USING THE
GFS SOLUTION...WHICH IS HANDLING THE DEEPENING EVOLUTION OF THE LOW
THE BEST THIS MORNING. THIS WILL BRING A WIDE VARIETY OF WEATHER
ACROSS CENTRAL IOWA TODAY.
STARTING OUT THIS MORNING...A BROAD WARM FRONT CURRENTLY STRETCHES
FROM NEAR OMAHA TO DUBUQUE...WITH TEMPERATURES IN THE MID 30S NORTH
OF THE BOUNDARY TO MID 40S SOUTH. THIS BOUNDARY WILL TIGHTEN DURING
THE COURSE OF THE DAY AS THE LOW APPROACHES...WITH HIGHS RANGING
FROM THE MID 30S NORTHWEST TO NEAR 60 IN THE SOUTHEAST. AS THE LOW
BEGINS TO PULL EASTWARD AFTER 18Z...THIS WILL LIKEWISE PULL THE
BOUNDARY EASTWARD AS A COLD FRONT THIS AFTERNOON AND EVENING.
WIDESPREAD RAIN IS EXPANDING ACROSS THE AREA NOW AS STRONG MIDLEVEL
KINEMATIC/290-300 K ISENTROPIC FORCING INTENSIFIES. INITIAL BOUT OF
PRECIP EARLIER IN THE NIGHT TIED IN WITH A REGION OF THETA-E
ADVECTION HAD TO FIGHT A SUB 800 MB DRY LAYER...BUT THE COLUMN IS
RAPIDLY SATURATING AND PRECIP IS BEING REPORTED AT MULTIPLE SITES.
BEST MIDLEVEL FORCING AND DEEPEST MOISTURE WILL BE COINCIDENT IN THE
15-21Z TIMEFRAME AND HAVE KEPT THE MAX QPF AMOUNTS DURING THIS
WINDOW. PWATS OF 0.50 TO 0.75 INCHES ARE 2 TO 3 STANDARD DEVIATIONS
ABOVE NORMAL AND DAILY TOTAL RAINFALL AMOUNTS OF 0.50 TO 0.75 INCHES
ARE POSSIBLE. THIS WIDESPREAD RAIN WILL LEAD TO RISES IN AREA RIVERS
WHICH HAVE STILL NOT FULLY RECOVERED FROM THE RECORD SETTING DELUGE
A WEEK AND A HALF AGO.
AS THE UPPER LEVEL WAVE MATURES A DRY SLOT WILL WRAP NORTHWARD
ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE STATE BETWEEN 18 AND
00Z. CURRENT POP AND QPF GRIDS MAY BE A LITTLE CONSERVATIVE ON THE
TIMING OF THIS DRY SLOT OVER SOUTHERN IOWA...BUT GIVEN THE SLOWER
TRENDS OF RECENT MODEL RUNS...HAVE KEPT CATEGORICAL POPS OVER THE
SOUTH UNTIL 16-17Z. THIS DRY SLOT WILL ALSO RESULT IN STEEPENING MID
LEVEL LAPSE RATES AND INCREASING INSTABILITY OVER THE SOUTHEASTERN
PORTION OF THE CWA. RAP BUFR SOUNDINGS FROM OTTUMWA SHOW 300-500
J/KG OF MUCAPE DEVELOPING BETWEEN 18-20Z. 0-6 KM SHEAR VALUES OF 40
TO 50 KTS WILL BE MORE THAN CAPABLE OF MAINTAINING ANY THUNDERSTORMS
THAT DO DEVELOP IN THE WARM SECTOR EARLY THIS AFTERNOON. THE THREAT
FOR ORGANIZED AND SEVERE CONVECTION WILL BE CONFINED TO A VERY
NARROW AND CONDITIONAL WINDOW ACROSS THE FAR SOUTHEAST...AND WITH
STORM MOTIONS OF 40 TO 50 KTS TO THE NORTHEAST...THESE STORMS WILL
RAPIDLY EXIT THE CWA. THE MAIN THREAT WOULD BE LARGE HAIL GIVEN THE
LOW FREEZING LEVELS...BUT IF SOMEHOW ANY SOLAR INSOLATION WERE TO
TAKE PLACE AND THE STORMS DID GO SURFACE BASED...THE 35 KTS OF 0-1
KM SHEAR AND PROXIMITY TO THE SURFACE LOW WOULD SUPPORT TORNADOES.
AGAIN...THE THREAT FOR ANY SEVERE WEATHER...LET ALONE TORNADOES...IS
VERY CONDITIONAL AND LIMITED TO A SHORT WINDOW FROM AROUND 19-22Z.
NEXT ON THE DOCKET ARE WINDS ON THE BACKSIDE OF THE LOW. A
TIGHTENING PRESSURE GRADIENT AND STRONG PRESSURE RISE COUPLET
IMMEDIATELY FOLLOWING THE LOW WILL RESULT IN WINDS OF 20 TO 25 KTS
SUSTAINED WITH GUSTS OF 30 TO 35 KTS ACROSS SOUTHERN IOWA THROUGH
THE LATE AFTERNOON AND EVENING HOURS. DEFORMATION ZONE AND ELEVATED
FG ZONE WILL LINGER ACROSS THE WESTERN PORTIONS OF THE CWA AS THE
FRONTAL BOUNDARY SLIDES EASTWARD. PRECIP IN THIS ZONE WILL CHANGE
OVER TO SNOW DURING THE COURSE OF THE AFTERNOON AS COOLER AIR MOVES
IN...BUT KEPT SNOW AMOUNTS AROUND A HALF INCH OR LESS GIVEN THE LACK
OF ANY STRONG CAA AND NEAR SURFACE TEMPS STILL IN THE LOW TO MID
30S. ROADS WILL LIKELY JUST STAY WET WITH ACCUMULATIONS ON GRASSY
AREAS.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
THE PATTERN WILL BE QUITE ACTIVE THROUGH THE ENTIRE PERIOD...WITH
SOME TRAVEL IMPACTS EXPECTED DURING THE EXTENDED...BUT CONFIDENCE
IN DETAILS REMAINS LOW FOR A MULTITUDE OF REASONS. AT ONSET EXPECT
A FRONTOGENETICALLY FORCED DEFORMATION ZONE WITH DEEP VERTICAL
MOTION TO BE QUICKLY RETREATING TO THE NORTH AND EAST EARLY IN THE
EVENING. CONFIDENCE IN SNOW ACCUMS HAS INCREASED...AND DENDRITIC
GROWTH ZONE LIFT WILL BE QUITE STRONG FOR A PERIOD...BUT IT WILL
BE VERY BRIEF AND TRANSIENT. TOTAL ACCUMS WILL GENERALLY BE AN
INCH OR LESS NORTH AND WEST...BUT TOTALS MAY VARY A BIT IN EITHER
DIRECTION DUE TO MELTING ON PAVEMENT VS VEGETATION AND LOCALIZED
HIGHER RATES. ANYTHING TOWARD THE INCH RANGE WOULD BE FAR NORTH.
STRONG SUBSIDENCE WILL THEN SET IN BY NIGHT. MIXING WILL BE FAIRLY
SHALLOW BUT MSLP GRADIENT MAY STILL ALLOW FOR GUSTS TO REACH 35
MPH OR SO THROUGH AT LEAST MIDNIGHT NE.
SHORT WAVE RIDING STRONG NRN CA/OR JET WILL THEN REACH THE MO VALLEY
THU. FORCING AND MOISTURE EXTENT WILL BE QUITE VARIABLE...NEVER
REALLY APPROACHING SATURATION. THIS WILL RESULT IN ANY AMOUNTS
BEING QUITE LIGHT...AND PTYPE IN QUESTION DUE TO ONLY A SMALL
WINDOW OF ICE INTRODUCTION. THUS HAVE LOW CHANCES WITH BOTH LIGHT
SNOW OR FLURRIES...AND LIGHT FREEZING RAIN/SPRINKLES POSSIBLE.
SHOULD SEE A BRIEF BREAK IN PRECIP THU NIGHT BEFORE SHORT WAVES
REACH CA AND CONTINUE TO CARVE OUT WRN CONUS LONG WAVE TROUGH...AND
EVENTUAL CUTOFF. THIS SETS UP A PROLONGED PERIOD OF SWLY FLOW
ALOFT...AND INVERTED TROUGHINESS INTO THE MID MS VALLEY. AS THE
CLOSED LOW FORMS IN THE SW...A SHORT WAVE WILL SPLIT AND RIDE THE SW
FLOW INTO THE MO VALLEY EARLY IN THE WEEKEND. PRECIP CHANCES WILL
INCREASE SHARPLY FRI INTO FRI NIGHT. ALTHOUGH THE DEEPEST QG FORCING
WILL REMAIN JUST TO OUR NORTH AND WEST...THE H85/H7 FORCING IS
EXTREME WITH HIGH CONTRIBUTIONS FROM THETA-E ADVECTION AND
FRONTOGENESIS. SNOWFALL RATES OVER NRN IA MAY BRIEFLY BE QUITE HIGH
WITH LOW STABILITY. GFS TICKS OFF SOME MUCAPES AND...ALTHOUGH
FAIRLY ELEVATED...ALSO SHOWS NEGATIVE SAT EPV WHICH WOULD BE
EXPECTED WITH THE LOW STATIC STABILITY AND MUCAPE REFLECTION. THUS
HAVE AN INCH OR TWO OF SNOW ACCUMS POSSIBLE NORTH THROUGH 12Z SAT
WITH ADDITIONAL AMOUNTS POSSIBLE AFTER THAT TIME. THE WAVE THEN
MOVES AWAY LATER SAT WITH THE ATTENTION TURNING TOWARD THE
APPROACHING CUTOFF LOW. SOME POPS LINGER THROUGH THE
WEEKEND...ESPECIALLY SOUTH...BUT NEITHER THE FORCING OR MOISTURE
IS TOO IMPRESSIVE.
THE PROGRESSION OF THE CUTOFF LOW WILL LIKELY RESULT IN THE BIGGEST
TRAVEL IMPACT OF THE HOLIDAY TRAVEL SEASON...BUT DETAILS ARE FAR
FROM CLEAR CUT. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH ITS
FARTHER WEST AND LESS SNOWY TRACK...BUT VARIABLE IN TIME OVER
RECENT RUNS. THE GFS TRACK AND TIMING HAVE BEEN MORE
CONSISTENT...AND POINT TOWARD A WIND BLOW HEAVY SNOW EVENT...BUT
IS A FASTER OUTLIER VS THE SLOWER CANADIAN AND ECMWF. RATHER THAN
FOCUSING ON THE DETAILS THE MAIN TAKE HOME POINT FOR NOW WOULD
APPEAR TO BE A SIGNIFICANT SYSTEM WILL AFFECT HOLIDAY TRAVEL IN OR
NEAR IA SOMETIME AROUND MON OR MON NIGHT. FOR THE TIME BEING HAVE
EITHER RAIN OR SNOW IN THE FORECAST WITH LOW CONFIDENCE...BUT THE
ECMWF ALSO HINTS AT THE POSSIBILITY OF A FREEZING RAIN/ICING EVENT
NRN HALF WITH A NICE ELEVATED WARM LAYER ABOVE SUB FREEZING
SURFACE TEMPS AND A BRISK ELY WIND. WILL NEED TO CONTINUE TO
MONITOR FOR THE POTENTIAL FOR EITHER ICING OR SNOW. WHATEVER
OCCURS LOOKS TO BE GONE BY TUE NIGHT EVEN WITH THE SLOWER ECMWF
SOLUTION.
&&
.AVIATION...23/12Z
ISSUED AT 540 AM CST WED DEC 23 2015
RAIN WILL CONTINUE ACROSS THE AREA THIS MORNING WITH CIGS AND
VSBYS FALLING TO IFR/LIFR LEVELS BY MID MORNING IN MOST
LOCATIONS. THUNDERSTORMS WILL ALSO BE POSSIBLE IN SOUTHEAST IOWA
DURING THE EARLY TO MID AFTERNOON HOURS. THE RAIN WILL TRANSITION
TO SNOW FOR A SHORT TIME ON THE BACKSIDE OF THE SYSTEM BEFORE
ENDING WITH CIGS GRADUALLY IMPROVING. HOWEVER...NORTHWESTERLY
WINDS WILL INCREASE TO 20 TO 25 KTS WITH GUSTS OVER 30 KTS THIS
EVENING AND INTO THE OVERNIGHT HOURS.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...SMALL
AVIATION...SKOW
AREA FORECAST DISCUSSION
NWS DES MOINES IA
445 AM CST WED DEC 23 2015
.SHORT TERM /TODAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
MORNING WATER VAPOR IMAGERY DEPICTS A SEASONABLY STRONG NEGATIVELY
TILTED LONGWAVE TROUGH AXIS SITUATED DOWN THE EASTERN FLANK OF THE
ROCKIES WITH A 150 KT JET IMPINGING ALONG ITS SOUTHWEST FLANK. AN
EMBEDDED SHORTWAVE/PV ANOMALY WILL EJECT NORTHEASTWARD FROM THE BASE
OF THE TROUGH TO THE SOUTHERN MISSOURI RIVER VALLEY BY 00Z THIS
EVENING. A DEEPENING 986 MB SURFACE CYCLONE OVER THE OKLAHOMA
PANHANDLE WILL LIKEWISE LIFT NORTHEASTWARD OVER THE COURSE OF THE
DAY AND BE SITUATED NEAR PRAIRIE DU CHIEN BY 00Z TONIGHT USING THE
GFS SOLUTION...WHICH IS HANDLING THE DEEPENING EVOLUTION OF THE LOW
THE BEST THIS MORNING. THIS WILL BRING A WIDE VARIETY OF WEATHER
ACROSS CENTRAL IOWA TODAY.
STARTING OUT THIS MORNING...A BROAD WARM FRONT CURRENTLY STRETCHES
FROM NEAR OMAHA TO DUBUQUE...WITH TEMPERATURES IN THE MID 30S NORTH
OF THE BOUNDARY TO MID 40S SOUTH. THIS BOUNDARY WILL TIGHTEN DURING
THE COURSE OF THE DAY AS THE LOW APPROACHES...WITH HIGHS RANGING
FROM THE MID 30S NORTHWEST TO NEAR 60 IN THE SOUTHEAST. AS THE LOW
BEGINS TO PULL EASTWARD AFTER 18Z...THIS WILL LIKEWISE PULL THE
BOUNDARY EASTWARD AS A COLD FRONT THIS AFTERNOON AND EVENING.
WIDESPREAD RAIN IS EXPANDING ACROSS THE AREA NOW AS STRONG MIDLEVEL
KINEMATIC/290-300 K ISENTROPIC FORCING INTENSIFIES. INITIAL BOUT OF
PRECIP EARLIER IN THE NIGHT TIED IN WITH A REGION OF THETA-E
ADVECTION HAD TO FIGHT A SUB 800 MB DRY LAYER...BUT THE COLUMN IS
RAPIDLY SATURATING AND PRECIP IS BEING REPORTED AT MULTIPLE SITES.
BEST MIDLEVEL FORCING AND DEEPEST MOISTURE WILL BE COINCIDENT IN THE
15-21Z TIMEFRAME AND HAVE KEPT THE MAX QPF AMOUNTS DURING THIS
WINDOW. PWATS OF 0.50 TO 0.75 INCHES ARE 2 TO 3 STANDARD DEVIATIONS
ABOVE NORMAL AND DAILY TOTAL RAINFALL AMOUNTS OF 0.50 TO 0.75 INCHES
ARE POSSIBLE. THIS WIDESPREAD RAIN WILL LEAD TO RISES IN AREA RIVERS
WHICH HAVE STILL NOT FULLY RECOVERED FROM THE RECORD SETTING DELUGE
A WEEK AND A HALF AGO.
AS THE UPPER LEVEL WAVE MATURES A DRY SLOT WILL WRAP NORTHWARD
ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE STATE BETWEEN 18 AND
00Z. CURRENT POP AND QPF GRIDS MAY BE A LITTLE CONSERVATIVE ON THE
TIMING OF THIS DRY SLOT OVER SOUTHERN IOWA...BUT GIVEN THE SLOWER
TRENDS OF RECENT MODEL RUNS...HAVE KEPT CATEGORICAL POPS OVER THE
SOUTH UNTIL 16-17Z. THIS DRY SLOT WILL ALSO RESULT IN STEEPENING MID
LEVEL LAPSE RATES AND INCREASING INSTABILITY OVER THE SOUTHEASTERN
PORTION OF THE CWA. RAP BUFR SOUNDINGS FROM OTTUMWA SHOW 300-500
J/KG OF MUCAPE DEVELOPING BETWEEN 18-20Z. 0-6 KM SHEAR VALUES OF 40
TO 50 KTS WILL BE MORE THAN CAPABLE OF MAINTAINING ANY THUNDERSTORMS
THAT DO DEVELOP IN THE WARM SECTOR EARLY THIS AFTERNOON. THE THREAT
FOR ORGANIZED AND SEVERE CONVECTION WILL BE CONFINED TO A VERY
NARROW AND CONDITIONAL WINDOW ACROSS THE FAR SOUTHEAST...AND WITH
STORM MOTIONS OF 40 TO 50 KTS TO THE NORTHEAST...THESE STORMS WILL
RAPIDLY EXIT THE CWA. THE MAIN THREAT WOULD BE LARGE HAIL GIVEN THE
LOW FREEZING LEVELS...BUT IF SOMEHOW ANY SOLAR INSOLATION WERE TO
TAKE PLACE AND THE STORMS DID GO SURFACE BASED...THE 35 KTS OF 0-1
KM SHEAR AND PROXIMITY TO THE SURFACE LOW WOULD SUPPORT TORNADOES.
AGAIN...THE THREAT FOR ANY SEVERE WEATHER...LET ALONE TORNADOES...IS
VERY CONDITIONAL AND LIMITED TO A SHORT WINDOW FROM AROUND 19-22Z.
NEXT ON THE DOCKET ARE WINDS ON THE BACKSIDE OF THE LOW. A
TIGHTENING PRESSURE GRADIENT AND STRONG PRESSURE RISE COUPLET
IMMEDIATELY FOLLOWING THE LOW WILL RESULT IN WINDS OF 20 TO 25 KTS
SUSTAINED WITH GUSTS OF 30 TO 35 KTS ACROSS SOUTHERN IOWA THROUGH
THE LATE AFTERNOON AND EVENING HOURS. DEFORMATION ZONE AND ELEVATED
FG ZONE WILL LINGER ACROSS THE WESTERN PORTIONS OF THE CWA AS THE
FRONTAL BOUNDARY SLIDES EASTWARD. PRECIP IN THIS ZONE WILL CHANGE
OVER TO SNOW DURING THE COURSE OF THE AFTERNOON AS COOLER AIR MOVES
IN...BUT KEPT SNOW AMOUNTS AROUND A HALF INCH OR LESS GIVEN THE LACK
OF ANY STRONG CAA AND NEAR SURFACE TEMPS STILL IN THE LOW TO MID
30S. ROADS WILL LIKELY JUST STAY WET WITH ACCUMULATIONS ON GRASSY
AREAS.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
THE PATTERN WILL BE QUITE ACTIVE THROUGH THE ENTIRE PERIOD...WITH
SOME TRAVEL IMPACTS EXPECTED DURING THE EXTENDED...BUT CONFIDENCE
IN DETAILS REMAINS LOW FOR A MULTITUDE OF REASONS. AT ONSET EXPECT
A FRONTOGENETICALLY FORCED DEFORMATION ZONE WITH DEEP VERTICAL
MOTION TO BE QUICKLY RETREATING TO THE NORTH AND EAST EARLY IN THE
EVENING. CONFIDENCE IN SNOW ACCUMS HAS INCREASED...AND DENDRITIC
GROWTH ZONE LIFT WILL BE QUITE STRONG FOR A PERIOD...BUT IT WILL
BE VERY BRIEF AND TRANSIENT. TOTAL ACCUMS WILL GENERALLY BE AN
INCH OR LESS NORTH AND WEST...BUT TOTALS MAY VARY A BIT IN EITHER
DIRECTION DUE TO MELTING ON PAVEMENT VS VEGETATION AND LOCALIZED
HIGHER RATES. ANYTHING TOWARD THE INCH RANGE WOULD BE FAR NORTH.
STRONG SUBSIDENCE WILL THEN SET IN BY NIGHT. MIXING WILL BE FAIRLY
SHALLOW BUT MSLP GRADIENT MAY STILL ALLOW FOR GUSTS TO REACH 35
MPH OR SO THROUGH AT LEAST MIDNIGHT NE.
SHORT WAVE RIDING STRONG NRN CA/OR JET WILL THEN REACH THE MO VALLEY
THU. FORCING AND MOISTURE EXTENT WILL BE QUITE VARIABLE...NEVER
REALLY APPROACHING SATURATION. THIS WILL RESULT IN ANY AMOUNTS
BEING QUITE LIGHT...AND PTYPE IN QUESTION DUE TO ONLY A SMALL
WINDOW OF ICE INTRODUCTION. THUS HAVE LOW CHANCES WITH BOTH LIGHT
SNOW OR FLURRIES...AND LIGHT FREEZING RAIN/SPRINKLES POSSIBLE.
SHOULD SEE A BRIEF BREAK IN PRECIP THU NIGHT BEFORE SHORT WAVES
REACH CA AND CONTINUE TO CARVE OUT WRN CONUS LONG WAVE TROUGH...AND
EVENTUAL CUTOFF. THIS SETS UP A PROLONGED PERIOD OF SWLY FLOW
ALOFT...AND INVERTED TROUGHINESS INTO THE MID MS VALLEY. AS THE
CLOSED LOW FORMS IN THE SW...A SHORT WAVE WILL SPLIT AND RIDE THE SW
FLOW INTO THE MO VALLEY EARLY IN THE WEEKEND. PRECIP CHANCES WILL
INCREASE SHARPLY FRI INTO FRI NIGHT. ALTHOUGH THE DEEPEST QG FORCING
WILL REMAIN JUST TO OUR NORTH AND WEST...THE H85/H7 FORCING IS
EXTREME WITH HIGH CONTRIBUTIONS FROM THETA-E ADVECTION AND
FRONTOGENESIS. SNOWFALL RATES OVER NRN IA MAY BRIEFLY BE QUITE HIGH
WITH LOW STABILITY. GFS TICKS OFF SOME MUCAPES AND...ALTHOUGH
FAIRLY ELEVATED...ALSO SHOWS NEGATIVE SAT EPV WHICH WOULD BE
EXPECTED WITH THE LOW STATIC STABILITY AND MUCAPE REFLECTION. THUS
HAVE AN INCH OR TWO OF SNOW ACCUMS POSSIBLE NORTH THROUGH 12Z SAT
WITH ADDITIONAL AMOUNTS POSSIBLE AFTER THAT TIME. THE WAVE THEN
MOVES AWAY LATER SAT WITH THE ATTENTION TURNING TOWARD THE
APPROACHING CUTOFF LOW. SOME POPS LINGER THROUGH THE
WEEKEND...ESPECIALLY SOUTH...BUT NEITHER THE FIC/290-300 K
ISENTROPIC FORCING OR MOISTURE IS TOO IMPRESSIVE.
THE PROGRESSION OF THE CUTOFF LOW WILL LIKELY RESULT IN THE BIGGEST
TRAVEL IMPACT OF THE HOLIDAY TRAVEL SEASON...BUT DETAILS ARE FAR
FROM CLEAR CUT. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH ITS
FARTHER WEST AND LESS SNOWY TRACK...BUT VARIABLE IN TIME OVER
RECENT RUNS. THE GFS TRACK AND TIMING HAVE BEEN MORE
CONSISTENT...AND POINT TOWARD A WIND BLOW HEAVY SNOW EVENT...BUT
IS A FASTER OUTLIER VS THE SLOWER CANADIAN AND ECMWF. RATHER THAN
FOCUSING ON THE DETAILS THE MAIN TAKE HOME POINT FOR NOW WOULD
APPEAR TO BE A SIGNIFICANT SYSTEM WILL AFFECT HOLIDAY TRAVEL IN OR
NEAR IA SOMETIME AROUND MON OR MON NIGHT. FOR THE TIME BEING HAVE
EITHER RAIN OR SNOW IN THE FORECAST WITH LOW CONFIDENCE...BUT THE
ECMWF ALSO HINTS AT THE POSSIBILITY OF A FREEZING RAIN/ICING EVENT
NRN HALF WITH A NICE ELEVATED WARM LAYER ABOVE SUB FREEZING
SURFACE TEMPS AND A BRISK ELY WIND. WILL NEED TO CONTINUE TO
MONITOR FOR THE POTENTIAL FOR EITHER ICING OR SNOW. WHATEVER
OCCURS LOOKS TO BE GONE BY TUE NIGHT EVEN WITH THE SLOWER ECMWF
SOLUTION.
&&
.AVIATION...23/06Z
ISSUED AT 1126 PM CST TUE DEC 22 2015
LOW PRESSURE SYSTEM WILL BRING RA TO SITES WITH CEILINGS AND
VISIBILITIES REMAINING MVFR AND LIKELY DROPPING TO IFR OR LIFR
WITH RA...GENERALLY BEYOND 12Z. EXPECT CONDITIONS TO IMPROVE
NEAR/AFTER 00Z AT SITES...THOUGH MVFR CEILINGS MAY LINGER. COULD
SEE SN AT NORTHERN SITES KMCW/KALO NEAR 00Z...BUT HAVE LEFT
MENTION OUT ATTM. WINDS WILL BE STRONG...SHIFTING TO THE NORTHWEST
AND BECOMING STRONG AND GUSTY NEAR/AFTER 00Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...SMALL
AVIATION...AWB
AREA FORECAST DISCUSSION...CORRECTED
NWS DES MOINES IA
436 AM CST WED DEC 23 2015
.SHORT TERM /TODAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
MORNING WATER VAPOR IMAGERY DEPICTS A SEASONABLY STRONG NEGATIVELY
TILTED LONGWAVE TROUGH AXIS SITUATED DOWN THE EASTERN FLANK OF THE
ROCKIES WITH A 150 KT JET IMPINGING ALONG ITS SOUTHWEST FLANK. AN
EMBEDDED SHORTWAVE/PV ANOMALY WILL EJECT NORTHEASTWARD FROM THE BASE
OF THE TROUGH TO THE SOUTHERN MISSOURI RIVER VALLEY BY 00Z THIS
EVENING. A DEEPENING 986 MB SURFACE CYCLONE OVER THE OKLAHOMA
PANHANDLE WILL LIKEWISE LIFT NORTHEASTWARD OVER THE COURSE OF THE
DAY AND BE SITUATED NEAR PRAIRIE DU CHIEN BY 00Z TONIGHT USING THE
GFS SOLUTION...WHICH IS HANDLING THE DEEPENING EVOLUTION OF THE LOW
THE BEST THIS MORNING. THIS WILL BRING A WIDE VARIETY OF WEATHER
ACROSS CENTRAL IOWA TODAY.
STARTING OUT THIS MORNING...A BROAD WARM FRONT CURRENTLY STRETCHES
FROM NEAR OMAHA TO DUBUQUE...WITH TEMPERATURES IN THE MID 30S NORTH
OF THE BOUNDARY TO MID 40S SOUTH. THIS BOUNDARY WILL TIGHTEN DURING
THE COURSE OF THE DAY AS THE LOW APPROACHES...WITH HIGHS RANGING
FROM THE MID 30S NORTHWEST TO NEAR 60 IN THE SOUTHEAST. AS THE LOW
BEGINS TO PULL EASTWARD AFTER 18Z...THIS WILL LIKEWISE PULL THE
BOUNDARY EASTWARD AS A COLD FRONT THIS AFTERNOON AND EVENING.
WIDESPREAD RAIN IS EXPANDING ACROSS THE AREA NOW AS STRONG MIDLEVEL
KINEMATIC/290-300 K ISENTROPIC FORCING INTENSIFIES. INITIAL BOUT OF
PRECIP EARLIER IN THE NIGHT TIED IN WITH A REGION OF THETA-E
ADVECTION HAD TO FIGHT A SUB 800 MB DRY LAYER...BUT THE COLUMN IS
RAPIDLY SATURATING AND PRECIP IS BEING REPORTED AT MULTIPLE SITES.
BEST MIDLEVEL FORCING AND DEEPEST MOISTURE WILL BE COINCIDENT IN THE
15-21Z TIMEFRAME AND HAVE KEPT THE MAX QPF AMOUNTS DURING THIS
WINDOW. PWATS OF 0.50 TO 0.75 INCHES ARE 2 TO 3 STANDARD DEVIATIONS
ABOVE NORMAL AND DAILY TOTAL RAINFALL AMOUNTS OF 0.50 TO 0.75 INCHES
ARE POSSIBLE. THIS WIDESPREAD RAIN WILL LEAD TO RISES IN AREA RIVERS
WHICH HAVE STILL NOT FULLY RECOVERED FROM THE RECORD SETTING DELUGE
A WEEK AND A HALF AGO.
AS THE UPPER LEVEL WAVE MATURES A DRY SLOT WILL WRAP NORTHWARD
ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE STATE BETWEEN 18 AND
00Z. CURRENT POP AND QPF GRIDS MAY BE A LITTLE CONSERVATIVE ON THE
TIMING OF THIS DRY SLOT OVER SOUTHERN IOWA...BUT GIVEN THE SLOWER
TRENDS OF RECENT MODEL RUNS...HAVE KEPT CATEGORICAL POPS OVER THE
SOUTH UNTIL 16-17Z. THIS DRY SLOT WILL ALSO RESULT IN STEEPENING MID
LEVEL LAPSE RATES AND INCREASING INSTABILITY OVER THE SOUTHEASTERN
PORTION OF THE CWA. RAP BUFR SOUNDINGS FROM OTTUMWA SHOW 300-500
J/KG OF MUCAPE DEVELOPING BETWEEN 18-20Z. 0-6 KM SHEAR VALUES OF 40
TO 50 KTS WILL BE MORE THAN CAPABLE OF MAINTAINING ANY THUNDERSTORMS
THAT DO DEVELOP IN THE WARM SECTOR EARLY THIS AFTERNOON. THE THREAT
FOR ORGANIZED AND SEVERE CONVECTION WILL BE CONFINED TO A VERY
NARROW AND CONDITIONAL WINDOW ACROSS THE FAR SOUTHEAST...AND WITH
STORM MOTIONS OF 40 TO 50 KTS TO THE NORTHEAST...THESE STORMS WILL
RAPIDLY EXIT THE CWA. THE MAIN THREAT WOULD BE LARGE HAIL GIVEN THE
LOW FREEZING LEVELS...BUT IF SOMEHOW ANY SOLAR INSOLATION WERE TO
TAKE PLACE AND THE STORMS DID GO SURFACE BASED...THE 35 KTS OF 0-1
KM SHEAR AND PROXIMITY TO THE SURFACE LOW WOULD SUPPORT TORNADOES.
AGAIN...THE THREAT FOR ANY SEVERE WEATHER...LET ALONE TORNADOES...IS
VERY CONDITIONAL AND LIMITED TO A SHORT WINDOW FROM AROUND 19-22Z.
NEXT ON THE DOCKET ARE WINDS ON THE BACKSIDE OF THE LOW. A
TIGHTENING PRESSURE GRADIENT AND STRONG PRESSURE RISE COUPLET
IMMEDIATELY FOLLOWING THE LOW WILL RESULT IN WINDS OF 20 TO 25 KTS
SUSTAINED WITH GUSTS OF 30 TO 35 KTS ACROSS SOUTHERN IOWA THROUGH
THE LATE AFTERNOON AND EVENING HOURS. DEFORMATION ZONE AND ELEVATED
FG ZONE WILL LINGER ACROSS THE WESTERN PORTIONS OF THE CWA AS THE
FRONTAL BOUNDARY SLIDES EASTWARD. PRECIP IN THIS ZONE WILL CHANGE
OVER TO SNOW DURING THE COURSE OF THE AFTERNOON AS COOLER AIR MOVES
IN...BUT KEPT SNOW AMOUNTS AROUND A HALF INCH OR LESS GIVEN THE LACK
OF ANY STRONG CAA AND NEAR SURFACE TEMPS STILL IN THE LOW TO MID
30S. ROADS WILL LIKELY JUST STAY WET WITH ACCUMULATIONS ON GRASSY
AREAS.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
THE PATTERN WILL BE QUITE ACTIVE THROUGH THE ENTIRE PERIOD...WITH
SOME TRAVEL IMPACTS EXPECTED DURING THE EXTENDED...BUT CONFIDENCE
IN DETAILS REMAINS LOW FOR A MULTITUDE OF REASONS. AT ONSET EXPECT
A FRONTOGENETICALLY FORCED DEFORMATION ZONE WITH DEEP VERTICAL
MOTION TO BE QUICKLY RETREATING TO THE NORTH AND EAST EARLY IN THE
EVENING. CONFIDENCE IN SNOW ACCUMS HAS INCREASED...AND DENDRITIC
GROWTH ZONE LIFT WILL BE QUITE STRONG FOR A PERIOD...BUT IT WILL
BE VERY BRIEF AND TRANSIENT. TOTAL ACCUMS WILL GENERALLY BE AN
INCH OR LESS NORTH AND WEST...BUT TOTALS MAY VARY A BIT IN EITHER
DIRECTION DUE TO MELTING ON PAVEMENT VS VEGETATION AND LOCALIZED
HIGHER RATES. ANYTHING TOWARD THE INCH RANGE WOULD BE FAR NORTH.
STRONG SUBSIDENCE WILL THEN SET IN BY NIGHT. MIXING WILL BE FAIRLY
SHALLOW BUT MSLP GRADIENT MAY STILL ALLOW FOR GUSTS TO REACH 35
MPH OR SO THROUGH AT LEAST MIDNIGHT NE.
SHORT WAVE RIDING STRONG NRN CA/OR JET WILL THEN REACH THE MO VALLEY
THU. FORCING AND MOISTURE EXTENT WILL BE QUITE VARIABLE...NEVER
REALLY APPROACHING SATURATION. THIS WILL RESULT IN ANY AMOUNTS
BEING QUITE LIGHT...AND PTYPE IN QUESTION DUE TO ONLY A SMALL
WINDOW OF ICE INTRODUCTION. THUS HAVE LOW CHANCES WITH BOTH LIGHT
SNOW OR FLURRIES...AND LIGHT FREEZING RAIN/SPRINKLES POSSIBLE.
SHOULD SEE A BRIEF BREAK IN PRECIP THU NIGHT BEFORE SHORT WAVES
REACH CA AND CONTINUE TO CARVE OUT WRN CONUS LONG WAVE TROUGH...AND
EVENTUAL CUTOFF. THIS SETS UP A PROLONGED PERIOD OF SWLY FLOW
ALOFT...AND INVERTED TROUGHINESS INTO THE MID MS VALLEY. AS THE
CLOSED LOW FORMS IN THE SW...A SHORT WAVE WILL SPLIT AND RIDE THE SW
FLOW INTO THE MO VALLEY EARLY IN THE WEEKEND. PRECIP CHANCES WILL
INCREASE SHARPLY FRI INTO FRI NIGHT. ALTHOUGH THE DEEPEST QG FORCING
WILL REMAIN JUST TO OUR NORTH AND WEST...THE H85/H7 FORCING IS
EXTREME WITH HIGH CONTRIBUTIONS FROM THETA-E ADVECTION AND
FRONTOGENESIS. SNOWFALL RATES OVER NRN IA MAY BRIEFLY BE QUITE HIGH
WITH LOW STABILITY. GFS TICKS OFF SOME MUCAPES AND...ALTHOUGH
FAIRLY ELEVATED...ALSO SHOWS NEGATIVE SAT EPV WHICH WOULD BE
EXPECTED WITH THE LOW STATIC STABILITY AND MUCAPE REFLECTION. THUS
HAVE AN INCH OR TWO OF SNOW ACCUMS POSSIBLE NORTH THROUGH 12Z SAT
WITH ADDITIONAL AMOUNTS POSSIBLE AFTER THAT TIME. THE WAVE THEN
MOVES AWAY LATER SAT WITH THE ATTENTION TURNING TOWARD THE
APPROACHING CUTOFF LOW. SOME POPS LINGER THROUGH THE
WEEKEND...ESPECIALLY SOUTH...BUT NEITHER THE FIC/290-300 K
ISENTROPIC FORCING OR MOISTURE IS TOO IMPRESSIVE.
THE PROGRESSION OF THE CUTOFF LOW WILL LIKELY RESULT IN THE BIGGEST
TRAVEL IMPACT OF THE HOLIDAY TRAVEL SEASON...BUT DETAILS ARE FAR
FROM CLEAR CUT. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH ITS
FARTHER WEST AND LESS SNOWY TRACK...BUT VARIABLE IN TIME OVER
RECENT RUNS. THE GFS TRACK AND TIMING HAVE BEEN MORE
CONSISTENT...AND POINT TOWARD A WIND BLOW HEAVY SNOW EVENT...BUT
IS A FASTER OUTLIER VS THE SLOWER CANADIAN AND ECMWF. RATHER THAN
FOCUSING ON THE DETAILS THE MAIN TAKE HOME POINT FOR NOW WOULD
APPEAR TO BE A SIGNIFICANT SYSTEM WILL AFFECT HOLIDAY TRAVEL IN OR
NEAR IA SOMETIME AROUND MON OR MON NIGHT. FOR THE TIME BEING HAVE
EITHER RAIN OR SNOW IN THE FORECAST WITH LOW CONFIDENCE...BUT THE
ECMWF ALSO HINTS AT THE POSSIBILITY OF A FREEZING RAIN/ICING EVENT
NRN HALF WITH A NICE ELEVATED WARM LAYER ABOVE SUB FREEZING
SURFACE TEMPS AND A BRISK ELY WIND. WILL NEED TO CONTINUE TO
MONITOR FOR THE POTENTIAL FOR EITHER ICING OR SNOW. WHATEVER
OCCURS LOOKS TO BE GONE BY TUE NIGHT EVEN WITH THE SLOWER ECMWF
SOLUTION.
&&
.AVIATION...23/06Z
ISSUED AT 1126 PM CST TUE DEC 22 2015
LOW PRESSURE SYSTEM WILL BRING RA TO SITES WITH CEILINGS AND
VISIBILITIES REMAINING MVFR AND LIKELY DROPPING TO IFR OR LIFR
WITH RA...GENERALLY BEYOND 12Z. EXPECT CONDITIONS TO IMPROVE
NEAR/AFTER 00Z AT SITES...THOUGH MVFR CEILINGS MAY LINGER. COULD
SEE SN AT NORTHERN SITES KMCW/KALO NEAR 00Z...BUT HAVE LEFT
MENTION OUT ATTM. WINDS WILL BE STRONG...SHIFTING TO THE NORTHWEST
AND BECOMING STRONG AND GUSTY NEAR/AFTER 00Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...SMALL
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
416 AM CST WED DEC 23 2015
.SHORT TERM /TODAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
MORNING WATER VAPOR IMAGERY DEPICTS A SEASONABLY STRONG NEGATIVELY
TILTED LONGWAVE TROUGH AXIS SITUATED DOWN THE EASTERN FLANK OF THE
ROCKIES WITH A 150 KT JET IMPINGING ALONG ITS SOUTHWEST FLANK. AN
EMBEDDED SHORTWAVE/PV ANOMALY WILL EJECT NORTHEASTWARD FROM THE BASE
OF THE TROUGH TO THE SOUTHERN MISSOURI RIVER VALLEY BY 00Z THIS
EVENING. A DEEPENING 986 MB SURFACE CYCLONE OVER THE OKLAHOMA
PANHANDLE WILL LIKEWISE LIFT NORTHEASTWARD OVER THE COURSE OF THE
DAY AND BE SITUATED NEAR PRAIRIE DU CHIEN BY 00Z TONIGHT USING THE
GFS SOLUTION...WHICH IS HANDLING THE DEEPENING EVOLUTION OF THE LOW
THE BEST THIS MORNING. THIS WILL BRING A WIDE VARIETY OF WEATHER
ACROSS CENTRAL IOWA TODAY.
STARTING OUT THIS MORNING...A BROAD WARM FRONT CURRENTLY STRETCHES
FROM NEAR OMAHA TO DUBUQUE...WITH TEMPERATURES IN THE MID 30S NORTH
OF THE BOUNDARY TO MID 40S SOUTH. THIS BOUNDARY WILL TIGHTEN DURING
THE COURSE OF THE DAY AS THE LOW APPROACHES...WITH HIGHS RANGING
FROM THE MID 30S NORTHWEST TO NEAR 60 IN THE SOUTHEAST. AS THE LOW
BEGINS TO PULL EASTWARD AFTER 18Z...THIS WILL LIKEWISE PULL THE
BOUNDARY EASTWARD AS A COLD FRONT THIS AFTERNOON AND EVENING.
WIDESPREAD RAIN IS EXPANDING ACROSS THE AREA NOW AS STRONG MIDLEVEL
KINEMATIC/290-300 K ISENTROPIC FORCING INTENSIFIES. INITIAL BOUT OF
PRECIP EARLIER IN THE NIGHT TIED IN WITH A REGION OF THETA-E
ADVECTION HAD TO FIGHT A SUB 800 MB DRY LAYER...BUT THE COLUMN IS
RAPIDLY SATURATING AND PREMORNING WATER VAPOR IMAGERY DEPICTS A
SEASONABLY STRONG NEGATIVELY TILTED LONGWAVE TROUGH AXIS SITUATED
DOWN THE EASTERN FLANK OF THE ROCKIES WITH A 150 KT JET IMPINGING
ALONG ITS SOUTHWEST FLANK. AN EMBEDDED SHORTWAVE/PV ANOMALY WILL
EJECT NORTHEASTWARD FROM THE BASE OF THE TROUGH TO THE SOUTHERN
MISSOURI RIVER VALLEY BY 00Z THIS EVENING. A DEEPENING 986 MB
SURFACE CYCLONE OVER THE OKLAHOMA PANHANDLE WILL LIKEWISE LIFT
NORTHEASTWARD OVER THE COURSE OF THE DAY AND BE SITUATED NEAR
PRAIRIE DU CHIEN BY 00Z TONIGHT USING THE GFS SOLUTION...WHICH IS
HANDLING THE DEEPENING EVOLUTION OF THE LOW THE BEST THIS MORNING.
THIS WILL BRING A WIDE VARIETY OF WEATHER ACROSS CENTRAL IOWA
TODAY.
STARTING OUT THIS MORNING...A BROAD WARM FRONT CURRENTLY STRETCHES
FROM NEAR OMAHA TO DUBUQUE...WITH TEMPERATURES IN THE MID 30S NORTH
OF THE BOUNDARY TO MID 40S SOUTH. THIS BOUNDARY WILL TIGHTEN DURING
THE COURSE OF THE DAY AS THE LOW APPROACHES...WITH HIGHS RANGING
FROM THE MID 30S NORTHWEST TO NEAR 60 IN THE SOUTHEAST. AS THE LOW
BEGINS TO PULL EASTWARD AFTER 18Z...THIS WILL LIKEWISE PULL THE
BOUNDARY EASTWARD AS A COLD FRONT THIS AFTERNOON AND EVENING.
WIDESPREAD RAIN IS EXPANDING ACROSS THE AREA NOW AS STRONG MIDLEVEL
KINEMATIC/290-300 K ISENTROPIC FORCING INTENSIFIES. INITIAL BOUT OF
PRECIP EARLIER IN THE NIGHT TIED IN WITH A REGION OF THETA-E
ADVECTION HAD TO FIGHT A SUB 800 MB DRY LAYER...BUT THE COLUMN IS
RAPIDLY SATURATING AND PRECIP IS BEING REPORTED AT MULTIPLE SITES.
BEST MIDLEVEL FORCING AND DEEPEST MOISTURE WILL BE COINCIDENT IN THE
15-21Z TIMEFRAME AND HAVE KEPT THE MAX QPF AMOUNTS DURING THIS
WINDOW. PWATS OF 0.50 TO 0.75 INCHES ARE 2 TO 3 STANDARD DEVIATIONS
ABOVE NORMAL AND DAILY TOTAL RAINFALL AMOUNTS OF 0.50 TO 0.75 INCHES
ARE POSSIBLE. THIS WIDESPREAD RAIN WILL LEAD TO RISES IN AREA RIVERS
WHICH HAVE STILL NOT FULLY RECOVERED FROM THE RECORD SETTING DELUGE
A WEEK AND A HALF AGO.
AS THE UPPER LEVEL WAVE MATURES A DRY SLOT WILL WRAP NORTHWARD
ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE STATE BETWEEN 18 AND
00Z. CURRENT POP AND QPF GRIDS MAY BE A LITTLE CONSERVATIVE ON THE
TIMING OF THIS DRY SLOT OVER SOUTHERN IOWA...BUT GIVEN THE SLOWER
TRENDS OF RECENT MODEL RUNS...HAVE KEPT CATEGORICAL POPS OVER THE
SOUTH UNTIL 16-17Z. THIS DRY SLOT WILL ALSO RESULT IN STEEPENING MID
LEVEL LAPSE RATES AND INCREASING INSTABILITY OVER THE SOUTHEASTERN
PORTION OF THE CWA. RAP BUFR SOUNDINGS FROM OTTUMWA SHOW 300-500
J/KG OF MUCAPE DEVELOPING BETWEEN 18-20Z. 0-6 KM SHEAR VALUES OF 40
TO 50 KTS WILL BE MORE THAN CAPABLE OF MAINTAINING ANY THUNDERSTORMS
THAT DO DEVELOP IN THE WARM SECTOR EARLY THIS AFTERNOON. THE THREAT
FOR ORGANIZED AND SEVERE CONVECTION WILL BE CONFINED TO A VERY
NARROW AND CONDITIONAL WINDOW ACROSS THE FAR SOUTHEAST...AND WITH
STORM MOTIONS OF 40 TO 50 KTS TO THE NORTHEAST...THESE STORMS WILL
RAPIDLY EXIT THE CWA. THE MAIN THREAT WOULD BE LARGE HAIL GIVEN THE
LOW FREEZING LEVELS...BUT IF SOMEHOW ANY SOLAR INSOLATION WERE TO
TAKE PLACE AND THE STORMS DID GO SURFACE BASED...THE 35 KTS OF 0-1
KM SHEAR AND PROXIMITY TO THE SURFACE LOW WOULD SUPPORT TORNADOES.
AGAIN...THE THREAT FOR ANY SEVERE WEATHER...LET ALONE TORNADOES...IS
VERY CONDITIONAL AND LIMITED TO A SHORT WINDOW FROM AROUND 19-22Z.
NEXT ON THE DOCKET ARE WINDS ON THE BACKSIDE OF THE LOW. A
TIGHTENING PRESSURE GRADIENT AND STRONG PRESSURE RISE COUPLET
IMMEDIATELY FOLLOWING THE LOW WILL RESULT IN WINDS OF 20 TO 25 KTS
SUSTAINED WITH GUSTS OF 30 TO 35 KTS ACROSS SOUTHERN IOWA THROUGH
THE LATE AFTERNOON AND EVENING HOURS. DEFORMATION ZONE AND ELEVATED
FG ZONE WILL LINGER ACROSS THE WESTERN PORTIONS OF THE CWA AS THE
FRONTAL BOUNDARY SLIDES EASTWARD. PRECIP IN THIS ZONE WILL CHANGE
OVER TO SNOW DURING THE COURSE OF THE AFTERNOON AS COOLER AIR MOVES
IN...BUT KEPT SNOW AMOUNTS AROUND A HALF INCH OR LESS GIVEN THE LACK
OF ANY STRONG CAA AND NEAR SURFACE TEMPS STILL IN THE LOW TO MID
30S. ROADS WILL LIKELY JUST STAY WET WITH ACCUMULATIONS ON GRASSY
AREAS.CIP IS BEING REPORTED AT MULTIPLE SITES. BEST MIDLEVEL
FORCING AND DEEPEST MOISTURE WILL BE COINCIDENT IN THE 15-21Z
TIMEFRAME AND HAVE KEPT THE MAX QPF AMOUNTS DURING THIS WINDOW.
PWATS OF 0.50 TO 0.75 INCHES ARE 2 TO 3 STANDARD DEVIATIONS ABOVE
NORMAL AND DAILY TOTAL RAINFALL AMOUNTS OF 0.50 TO 0.75 INCHES ARE
POSSIBLE. THIS WIDESPREAD RAIN WILL LEAD TO RISES IN AREA RIVERS
WHICH HAVE STILL NOT FULLY RECOVERED FROM THE RECORD SETTING
DELUGE A WEEK AND A HALF AGO.
AS THE UPPER LEVEL WAVE MATURES A DRY SLOT WILL WRAP NORTHWARD
ACROSS THE SOUTHERN AND EASTERN PORTIONS OF THE STATE BETWEEN 18 AND
00Z. CURRENT POP AND QPF GRIDS MAY BE A LITTLE CONSERVATIVE ON THE
TIMING OF THIS DRY SLOT OVER SOUTHERN IOWA...BUT GIVEN THE SLOWER
TRENDS OF RECENT MODEL RUNS...HAVE KEPT CATEGORICAL POPS OVER THE
SOUTH UNTIL 16-17Z. THIS DRY SLOT WILL ALSO RESULT IN STEEPENING MID
LEVEL LAPSE RATES AND INCREASING INSTABILITY OVER THE SOUTHEASTERN
PORTION OF THE CWA. RAP BUFR SOUNDINGS FROM OTTUMWA SHOW 300-500
J/KG OF MUCAPE DEVELOPING BETWEEN 18-20Z. 0-6 KM SHEAR VALUES OF 40
TO 50 KTS WILL BE MORE THAN CAPABLE OF MAINTAINING ANY THUNDERSTORMS
THAT DO DEVELOP IN THE WARM SECTOR EARLY THIS AFTERNOON. THE THREAT
FOR ORGANIZED AND SEVERE CONVECTION WILL BE CONFINED TO A VERY
NARROW AND CONDITIONAL WINDOW ACROSS THE FAR SOUTHEAST...AND WITH
STORM MOTIONS OF 40 TO 50 KTS TO THE NORTHEAST...THESE STORMS WILL
RAPIDLY EXIT THE CWA. THE MAIN THREAT WOULD BE LARGE HAIL GIVEN THE
LOW FREEZING LEVELS...BUT IF SOMEHOW ANY SOLAR INSOLATION WERE TO
TAKE PLACE AND THE STORMS DID GO SURFACE BASED...THE 35 KTS OF 0-1
KM SHEAR AND PROXIMITY TO THE SURFACE LOW WOULD SUPPORT TORNADOES.
AGAIN...THE THREAT FOR ANY SEVERE WEATHER...LET ALONE TORNADOES...IS
VERY CONDITIONAL AND LIMITED TO A SHORT WINDOW FROM AROUND 19-22Z.
NEXT ON THE DOCKET ARE WINDS ON THE BACKSIDE OF THE LOW. A
TIGHTENING PRESSURE GRADIENT AND STRONG PRESSURE RISE COUPLET
IMMEDIATELY FOLLOWING THE LOW WILL RESULT IN WINDS OF 20 TO 25 KTS
SUSTAINED WITH GUSTS OF 30 TO 35 KTS ACROSS SOUTHERN IOWA THROUGH
THE LATE AFTERNOON AND EVENING HOURS. DEFORMATION ZONE AND ELEVATED
FG ZONE WILL LINGER ACROSS THE WESTERN PORTIONS OF THE CWA AS THE
FRONTAL BOUNDARY SLIDES EASTWARD. PRECIP IN THIS ZONE WILL CHANGE
OVER TO SNOW DURING THE COURSE OF THE AFTERNOON AS COOLER AIR MOVES
IN...BUT KEPT SNOW AMOUNTS AROUND A HALF INCH OR LESS GIVEN THE LACK
OF ANY STRONG CAA AND NEAR SURFACE TEMPS STILL IN THE LOW TO MID
30S. ROADS WILL LIKELY JUST STAY WET WITH ACCUMULATIONS ON GRASSY
AREAS.
.LONG TERM /TONIGHT THROUGH TUESDAY/...
ISSUED AT 410 AM CST WED DEC 23 2015
THE PATTERN WILL BE QUITE ACTIVE THROUGH THE ENTIRE PERIOD...WITH
SOME TRAVEL IMPACTS EXPECTED DURING THE EXTENDED...BUT CONFIDENCE
IN DETAILS REMAINS LOW FOR A MULTITUDE OF REASONS. AT ONSET EXPECT
A FRONTOGENETICALLY FORCED DEFORMATION ZONE WITH DEEP VERTICAL
MOTION TO BE QUICKLY RETREATING TO THE NORTH AND EAST EARLY IN THE
EVENING. CONFIDENCE IN SNOW ACCUMS HAS INCREASED...AND DENDRITIC
GROWTH ZONE LIFT WILL BE QUITE STRONG FOR A PERIOD...BUT IT WILL
BE VERY BRIEF AND TRANSIENT. TOTAL ACCUMS WILL GENERALLY BE AN
INCH OR LESS NORTH AND WEST...BUT TOTALS MAY VARY A BIT IN EITHER
DIRECTION DUE TO MELTING ON PAVEMENT VS VEGETATION AND LOCALIZED
HIGHER RATES. ANYTHING TOWARD THE INCH RANGE WOULD BE FAR NORTH.
STRONG SUBSIDENCE WILL THEN SET IN BY NIGHT. MIXING WILL BE FAIRLY
SHALLOW BUT MSLP GRADIENT MAY STILL ALLOW FOR GUSTS TO REACH 35
MPH OR SO THROUGH AT LEAST MIDNIGHT NE.
SHORT WAVE RIDING STRONG NRN CA/OR JET WILL THEN REACH THE MO VALLEY
THU. FORCING AND MOISTURE EXTENT WILL BE QUITE VARIABLE...NEVER
REALLY APPROACHING SATURATION. THIS WILL RESULT IN ANY AMOUNTS
BEING QUITE LIGHT...AND PTYPE IN QUESTION DUE TO ONLY A SMALL
WINDOW OF ICE INTRODUCTION. THUS HAVE LOW CHANCES WITH BOTH LIGHT
SNOW OR FLURRIES...AND LIGHT FREEZING RAIN/SPRINKLES POSSIBLE.
SHOULD SEE A BRIEF BREAK IN PRECIP THU NIGHT BEFORE SHORT WAVES
REACH CA AND CONTINUE TO CARVE OUT WRN CONUS LONG WAVE TROUGH...AND
EVENTUAL CUTOFF. THIS SETS UP A PROLONGED PERIOD OF SWLY FLOW
ALOFT...AND INVERTED TROUGHINESS INTO THE MID MS VALLEY. AS THE
CLOSED LOW FORMS IN THE SW...A SHORT WAVE WILL SPLIT AND RIDE THE SW
FLOW INTO THE MO VALLEY EARLY IN THE WEEKEND. PRECIP CHANCES WILL
INCREASE SHARPLY FRI INTO FRI NIGHT. ALTHOUGH THE DEEPEST QG FORCING
WILL REMAIN JUST TO OUR NORTH AND WEST...THE H85/H7 FORCING IS
EXTREME WITH HIGH CONTRIBUTIONS FROM THETA-E ADVECTION AND
FRONTOGENESIS. SNOWFALL RATES OVER NRN IA MAY BRIEFLY BE QUITE HIGH
WITH LOW STABILITY. GFS TICKS OFF SOME MUCAPES AND...ALTHOUGH
FAIRLY ELEVATED...ALSO SHOWS NEGATIVE SAT EPV WHICH WOULD BE
EXPECTED WITH THE LOW STATIC STABILITY AND MUCAPE REFLECTION. THUS
HAVE AN INCH OR TWO OF SNOW ACCUMS POSSIBLE NORTH THROUGH 12Z SAT
WITH ADDITIONAL AMOUNTS POSSIBLE AFTER THAT TIME. THE WAVE THEN
MOVES AWAY LATER SAT WITH THE ATTENTION TURNING TOWARD THE
APPROACHING CUTOFF LOW. SOME POPS LINGER THROUGH THE
WEEKEND...ESPECIALLY SOUTH...BUT NEITHER THE FORCING OR MOISTURE
IS TOO IMPRESSIVE.
THE PROGRESSION OF THE CUTOFF LOW WILL LIKELY RESULT IN THE BIGGEST
TRAVEL IMPACT OF THE HOLIDAY TRAVEL SEASON...BUT DETAILS ARE FAR
FROM CLEAR CUT. THE ECMWF HAS BEEN FAIRLY CONSISTENT WITH ITS
FARTHER WEST AND LESS SNOWY TRACK...BUT VARIABLE IN TIME OVER
RECENT RUNS. THE GFS TRACK AND TIMING HAVE BEEN MORE
CONSISTENT...AND POINT TOWARD A WIND BLOW HEAVY SNOW EVENT...BUT
IS A FASTER OUTLIER VS THE SLOWER CANADIAN AND ECMWF. RATHER THAN
FOCUSING ON THE DETAILS THE MAIN TAKE HOME POINT FOR NOW WOULD
APPEAR TO BE A SIGNIFICANT SYSTEM WILL AFFECT HOLIDAY TRAVEL IN OR
NEAR IA SOMETIME AROUND MON OR MON NIGHT. FOR THE TIME BEING HAVE
EITHER RAIN OR SNOW IN THE FORECAST WITH LOW CONFIDENCE...BUT THE
ECMWF ALSO HINTS AT THE POSSIBILITY OF A FREEZING RAIN/ICING EVENT
NRN HALF WITH A NICE ELEVATED WARM LAYER ABOVE SUB FREEZING
SURFACE TEMPS AND A BRISK ELY WIND. WILL NEED TO CONTINUE TO
MONITOR FOR THE POTENTIAL FOR EITHER ICING OR SNOW. WHATEVER
OCCURS LOOKS TO BE GONE BY TUE NIGHT EVEN WITH THE SLOWER ECMWF
SOLUTION.
&&
.AVIATION...23/06Z
ISSUED AT 1126 PM CST TUE DEC 22 2015
LOW PRESSURE SYSTEM WILL BRING RA TO SITES WITH CEILINGS AND
VISIBILITIES REMAINING MVFR AND LIKELY DROPPING TO IFR OR LIFR
WITH RA...GENERALLY BEYOND 12Z. EXPECT CONDITIONS TO IMPROVE
NEAR/AFTER 00Z AT SITES...THOUGH MVFR CEILINGS MAY LINGER. COULD
SEE SN AT NORTHERN SITES KMCW/KALO NEAR 00Z...BUT HAVE LEFT
MENTION OUT ATTM. WINDS WILL BE STRONG...SHIFTING TO THE NORTHWEST
AND BECOMING STRONG AND GUSTY NEAR/AFTER 00Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SKOW
LONG TERM...SMALL
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1131 PM CST TUE DEC 22 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 345 PM CST TUE DEC 22 2015
REMNANTS OF THE MORNING STRATUS SHIELD REMAIN OVER THE NORTHEASTERN
THIRD TO HALF OF THE STATE AND WILL GENERALLY REMAIN SO THIS EVENING
AS THE STRONG INVERSION REMAINS IN PLACE AND WE LOSE WHATS LEFT OF
ANY DAYTIME HEATING AND MIXING. AS A RESULT...CEILINGS AND
VISIBILITIES WILL CONTINUE TO BE LOW IN THOSE AREAS...AROUND 500
FEET AND A COUPLE MILES OR LESS RESPECTIVELY THROUGH THE SHORT TERM.
HAVE NOT CURRENTLY INTRODUCED FOG INTO THE GRIDS...BUT MAY WARRANT
SO DURING THE EVENING...ESPECIALLY FOR AREAS THAT HOLD OFF ON SEEING
PRECIP LONGER AND MOISTURE ADVECTION CONTINUES. AREAS THAT SAW
CLEARING WILL PROGRESSIVELY SEE HIGH BASED CLOUDS MOVE IN BEFORE
CEILINGS FALL AGAIN AS SURFACE LOW AND FORCING PROGRESSES TOWARDS
THE REGION FROM CENTRAL/EASTERN KANSAS.
THE AFOREMENTIONED SURFACE LOW WILL BE THE MAIN CONCERN IN THE SHORT
TERM...BEGINNING TO REALLY INFLUENCE THE AREA AFTER 03Z. THROUGH THE
DAY...NAM AND HRRR HAVE TENDED TO HANDLE THE CLEARING BEST...SO HAVE
TRENDED THAT WAY IN THE GRIDS FOR THIS EVENING. WITHIN THE SHORT
TERM WINDOW...BEST INITIAL FORCING IS THERMODYNAMIC WITH A GOOD PUSH
OF THETA-E ADVECTION ALONG WITH ISENTROPIC LIFT IN THE 290K REGION.
THE DEFORMATION ZONE WILL ALSO BEGIN TO SET UP IN NORTHWEST IOWA
AFTER 06Z...FURTHER BOOSTING LIFT. CURRENTLY...THE COLUMN IS QUITE
DRY FROM ABOUT 850MB TO 500MB...WHICH CALLS INTO SOME QUESTION WHEN
THE COLUMN WILL SATURATE AND PRECIP WILL BEGIN...BUT BEGAN TO UP
POPS IN NORTHWEST IOWA AROUND 5Z AND THROUGH THE SHORT TERM WINDOW
IN CONJUNCTION WITH HRRR/NAM SOLUTIONS.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 345 PM CST TUE DEC 22 2015
THE LONG TERM REMAINS ACTIVE WITH SEVERAL SHORTWAVES EJECTING OUT
OF THE BAST OF A LONG WAVE TROUGH OUT WEST. WE BEGIN THE PERIOD
WITH THE SYSTEM AFFECTING THE SHORT TERM LIFTING NORTHEAST. THERE
WILL BE A BRIEF PERIOD OF OF SNOW ON THE BACKSIDE OF THIS SYSTEM
AS IT LIFTS OFF TO THE NORTHEAST. MOST OF THE FORCING EXITS BEFORE
THE CHANGEOVER SO I AM NOT LOOKING AT MUCH ACCUMULATION PLUS WE
WILL BE TOO WARM ALOFT...MAY EVEN SEE A BIT OF FREEZING RAIN WITH
THIS. ALSO...SOME INSTABILITY WORKS INTO EASTERN IOWA AS THIS
SYSTEM LIFTS OUT WHICH MEANS WE COULD SEE SOME ISOLATED THUNDER
WEDNESDAY AFTERNOON. AFTER THIS SYSTEM DEPARTS THERE WILL BE A
BRIEF RESPITE WEDNESDAY NIGHT BEFORE ANOTHER WEAK SHORTWAVE
TRANSLATES ACROSS THE SOUTH AND EAST. TEMPS WILL BE WARM ENOUGH
FOR RAIN WITH THIS SO NOT FORESEEING MUCH IN THE WAY OF TRAVEL
PROBLEMS BUT WITH RIVERS STILL VERY HIGH...ANY HEAVIER RAINFALL
WILL LIKELY RESULT IN FLOODING AGAIN.
THE NEXT MAIN SYSTEM WILL BE A DEEPENING LOW ACROSS THE SOUTHERN
PLAINS LIFTING NORTHEAST. I THINK THE MODELS ARE LIKELY TOO FAST
WITH THIS SYSTEM GIVEN HOW THE LOW IS DEEPENING BUT INITIALLY THIS
WILL BE A RAIN PRODUCER WITH COLD AIR WRAPPING INTO THE LOW
CHANGING PRECIP OVER TO SNOW. THIS ONE MAY BE A POTENTIAL SNOW
PRODUCER FOR US AND NEEDS TO BE WATCHED BUT WILL ALSO BRING
ADDITIONAL FLOODING THREATS.
&&
.AVIATION...23/06Z
ISSUED AT 1126 PM CST TUE DEC 22 2015
LOW PRESSURE SYSTEM WILL BRING RA TO SITES WITH CEILINGS AND
VISIBILITIES REMAINING MVFR AND LIKELY DROPPING TO IFR OR LIFR
WITH RA...GENERALLY BEYOND 12Z. EXPECT CONDITIONS TO IMPROVE
NEAR/AFTER 00Z AT SITES...THOUGH MVFR CEILINGS MAY LINGER. COULD
SEE SN AT NORTHERN SITES KMCW/KALO NEAR 00Z...BUT HAVE LEFT
MENTION OUT ATTM. WINDS WILL BE STRONG...SHIFTING TO THE NORTHWEST
AND BECOMING STRONG AND GUSTY NEAR/AFTER 00Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CURTIS
LONG TERM...FAB
AVIATION...AWB
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
511 PM CST THU DEC 24 2015
...AVIATION UPDATE...
.SHORT TERM...(This Evening through Friday)
Issued at 258 PM CST THU DEC 24 2015
A large upper trough remains over the western and
central US this afternoon. Near Kansas, there was an exiting
shortwave across Iowa and a strong upper jet oriented SW to NE
across Kansas. Low clouds over northeast Kansas dissipated this
afternoon in area subsidence behind the shortwave. A weak area of
surface high pressure should be centered over northwest Missouri
by 12Z Friday morning. There will likely be some mid/high clouds
over the area tonight due to the upper jet. Patchy fog is
possible, especially in our eastern counties closer to the center
of the high.
Surface low deepens over the western plain on Friday and southeast
surface flow and warm advection should occur over eastern Kansas.
Relatively mild and dry conditions for Christmas day. Increasing
moisture overall should result in increased cloudiness during the
day. Precipitation will likely hold off through the afternoon.
.LONG TERM...(Friday Night through Thursday)
Issued at 258 PM CST THU DEC 24 2015
By Saturday morning a piece of energy will break off the main
shortwave trough over the southwest US. This will drag a cold front
through the area during the day Saturday. A 1040 mb high will
advance southward through the high plains, which will reinforce a
sub freezing air mass just north of the area. The freezing line may
reach north central KS by the evening hours, and push through
portions of eastern KS through the overnight. The models then show a
wave of post frontal precip developing and spreading northward
across eastern KS during the overnight. During this period the
freezing air could undercut precip so there may be a transition
to from rain to a wintry mix. There seems to be a warm nose
present initially, but how warm it will be is uncertain. This will
depend on the slope of the cold air, and where the low to mid
level fronts will be located. During this period there may be
light accumulations that could disrupt travel. By noon Sunday most
of the precip gets shunted to the south as the surface high tracks
across the northern US. At this time the main shortwave trough
will begin to eject out over the plains. The exact strength and
track is still unknown, but the models seem to depict cooler
solutions. As of now the best chance for accumulating winter
precip would be Sunday night into Monday night. Stay tuned for
updates.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 511 PM CST THU DEC 24 2015
With no real forcing to speak of, main concern is whether a
radiational fog will develop. At this time, think probabilities
for ground fog are to low to include in the forecast and think VFR
conditions should prevail. RAP and NAM forecast soundings show
the potential for some dry air entraining at the top of the
boundary layer and there may be some scattered high clouds
inhibiting radiational cooling just enough. Nevertheless will
monitor trends this evening for possible ground fog development.
&&
.TOP Watches/Warnings/Advisories...NONE. &&
$$
SHORT TERM...Johnson
LONG TERM...Sanders
AVIATION...Wolters
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
342 AM CST WED DEC 23 2015
.SHORT TERM...(Today and Tonight)
Issued at 301 AM CST WED DEC 23 2015
A few areas of weak vorticity maxima were rotating through the base
of the upper trough this morning. The first lobe has developed a
swath of showers lifting northward. Decent lapse rates in the low and
mid levels has generated enough weak instability for a few
thunderstorms over east central Kansas. This activity is expected
to exit into Nebraska before sunrise. Meanwhile, moisture advection
continues to increase ahead of a sfc low currently over southwest
Kansas. This could allow additional showers through mid afternoon as
the second lobe of vorticity deepens as it phases with the sfc low.
Mostly cloudy skies are anticipated with the sfc low encompassing
the area. Temperatures over north central Kansas today are expected
to cool to near 40 degrees as cloud cover increases and lingers
behind the sfc low. Further south, temps are steady in the lower
50s. The tightening pressure gradient with the sfc low will cause
southwesterly winds to increase between 15 and 20 mph sustained with
gusts near 30 mph.
This evening, skies clear temporarily before clouds return with
another small yet strong vorticity lobe shifts east over northern
Kansas and southern Nebraska. With the exception of
the NAM, the track of the axis would suggest areas of light rain
transitioning to snow are possible after midnight for areas along
and north of Interstate 70. Trace amounts are expected by Thursday
morning with perhaps up to an inch of snow near the Nebraska border.
Winds become light overnight as temps fall back to the upper 20s and
low 30s.
.LONG TERM...(Thursday through Tuesday)
Issued at 301 AM CST WED DEC 23 2015
Weak shortwave still forecast to graze the northern counties
through the morning on Thursday. Temperatures for that area in the
morning are still below freezing, and will carry light snow as
the precip type but not expecting much in the way of accumulation
as temperatures rise into the 40s for north central Kansas and
lower 50s for east central. Passage of that wave to our north does
aid in pushing weak frontal boundary temporarily into the area
with little sensible weather impacts. As this front lifts back
north on Friday and raises high temperatures a few degrees from
Thursdays numbers, could see some light rain showers in the
northern counties.
The reprieve is temporary however as next upper trof continues to
advance eastward, with one round of energy moving into the
northern plains and another piece dropping southward into the four
corners region. Leading northern wave advances a strong cold front
southward into the Central Plains. By 12z Saturday this front is
forecast by both EC and GFS to be just entering our western
counties, sweeping across eastern Kansas through the day Saturday.
Precipitation amounts with this feature are light, but without ice
in the column would likely come in the form of rain transitioning
to a light freezing rain/drizzle. This colder air continues to
feed southward through the night Saturday night into Sunday, with
enough lift continuing up and over the front over our area that
this light freezing precip may continue overnight into Sunday
morning. Model differences start to become significantly important
in this timeframe, as GFS has a saturated column and would bring
light accumulating snow toward Sunday morning, while EC has a warm
nose aloft and would continue a freezing rain profile. Both models
suggest a lull in precip for a short period of time Sunday before
noon as a mid level ridge moves over the area.
Differences in the forecast beyond 18z Sunday make forecasting
precipitation types a challenge this far out in the forecast. GFS
is taking a faster track with the upper low, lifting it from the
big bend of Texas through southeastern OK and into northern
Illinois by 0z Tuesday, and keeping our area now below freezing
and suggesting all snow for precipitation type Sunday night
through Monday evening, not to mention spitting out a respectable
snow band across the eastern counties through the day on Monday.
In the same time window of Sunday night through 0z Tuesday, the
EC takes the system from the big bend out only out to central
Oklahoma, wrapping more warm air into the system and changing
precip back over to rain across the southeast half of the forecast
area late Monday afternoon, while snow continues in the north
central counties. The GFS solution looks fast in how quickly it
ejects the system to the northeast, but the ensembles offer no
better idea either way on if a faster or slower solution is more
credible.
The takeaway at this point would be to be ready for the
potential of some type of a wintery mix on Saturday afternoon
through Sunday morning, with light accumulations possible. This in
and of itself could make for tricky traveling at those times.
Sunday day through Monday holds potential for all precipitation
types, including significant accumulating snow, or freezing rain,
or even some locally heavy rainfall for our east. Since the energy
associated with this system is still out off the Canadian Pacific
coast, it may be several more runs before guidance starts to
capture better concensus on this system.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday) Issued at
1110 PM CST TUE DEC 22 2015
Main change to the forecast is to delay the onset of MVFR CIGS at
the terminals based on the RAP13. The preference is still for a
blend of the RAP and GFS for CIGS as the NAM continues to insist
on LIFR conditions. However there are no IFR CIGS upstream where
the NAM shows they should be now. The low clouds may scatter out
at TOP and FOE by the late morning only to move back in during the
afternoon as the upper low passes overhead. Timing this is low
confidence. Have a mention of VCSH thinking -RA will be more
scattered in nature at the terminals.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Bowen
LONG TERM...67
AVIATION...Wolters
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1110 PM CST TUE DEC 22 2015
...AVIATION UPDATE...
.SHORT TERM...(This Evening through Wednesday)
Issued at 305 PM CST TUE DEC 22 2015
Next system to affect eastern Kansas tonight and Wednesday was
located over the southern Rockies this afternoon at 20Z. The upper
trough moves into western Kansas tonight, then moves into eastern
Kansas by Wednesday morning before moving northeast Wednesday
afternoon. A surface front will move southeast into north central
Kansas by Wednesday morning. The front will then spread southeast
across the rest of the eastern Kansas as the surface low ejects
northeast in the afternoon. Models continue to show some light
precipitation developing late this evening with better forcing and
moisture transport after midnight into early Wednesday across
northeast and east central Kansas. Forecast soundings show some
elevated instability and lapse rates steepen beneath the upper trough
moving through. Parts of northeast and east central Kansas will
possibly see some isolated thunderstorms mainly late tonight through
the morning hours on Wednesday. Temperatures should be on the mild
side tonight with southerly winds keeping the lower boundary layer
mixed. There may be some clearing in the afternoon hours as the
system departs. Highs on Wednesday with clouds and cold advection
behind the cold front have kept high temperatures on the cool side
in the mid 40s to lower 50s.
.LONG TERM...(Wednesday Night through Tuesday)
Issued at 305 PM CST TUE DEC 22 2015
Bottom line up front: The storm this weekend has the potential to
bring heavy rains which could cause flooding, freezing rain which
could accumulate along with snow especially across central and
north central Kansas. The storm bears monitoring given the amount
of precip it could bring along with winds/temps as it passes by
come Monday.
In the Weds night time frame a shortwave will move across the area
bringing a chance for rain or snow. Soundings suggest mainly snow
north of I-70 however the lift is more focused into Nebraska and
given speed of system have opted to keep precip chcs near guidance
which suggests low precip chcs along the I-70 corridor with 30-40
pops north. QPF forecasts and snow ratios suggest any accums
should be less than one inch across our northern counties if any
accums did occur.
The focus then turns to the large storm that is now across the
Gulf of Alaska and is forecast to dive into the West through late
week. GFS and ECMWF have both struggled with consistency of the
system`s track and timing and based on the 12z runs they may
finally be converging on a solution that brings the upper low into
AZ/NM by Sat afternoon. Strong southerly flow between the upper
low and the unusually strong subtropical high east of FL should
draw up very high PWATS ahead of the storm. The focus for heaviest
rains Sat should set up just southeast of the CWA closer to the
Sfc-925mb boundary and hopefully it will remain there through
Sunday. The temp profile suggests rain would be precip type
through Saturday sundown before colder air begins to move into the
area behind the initial frontal wave. Forecast sfc temps and warm
nose profiles suggest a mix of snow, sleet or freezing rain
developing Sat night which could persist into Sunday depending on
sfc air temps which at this point are highly uncertain. What is
most likely is that we`d see little if any diurnal come Sunday
with the freezing line bisecting somewhere across the CWA. The
strongest forcing and heaviest precip will fall as the upper
system lifts out and tracks across the area Sunday night into
early Monday based on current model tracks. The precip types
remain uncertain but we are more confident that precip amounts as
the upper system lifts out could be 1 to 2 inches of liquid. That
may fall as rain, freezing rain or even snow depending on temp
profiles but takeaway is that all are possible within our CWA so
this storm bears close monitoring. All told the potential exists
for 1 to 3 inches of rain perhaps more across our southeast half
depending on the track of this system. At least some of that could
fall as freezing rain or snow which also suggests a heavy wet snow
event for central or north central KS. As mentioned...bottom line
is this could be a high impact storm for our CWA Sat night through
Monday.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday) Issued at
1110 PM CST TUE DEC 22 2015
Main change to the forecast is to delay the onset of MVFR CIGS at
the terminals based on the RAP13. The preference is still for a
blend of the RAP and GFS for CIGS as the NAM continues to insist
on LIFR conditions. However there are no IFR CIGS upstream where
the NAM shows they should be now. The low clouds may scatter out
at TOP and FOE by the late morning only to move back in during the
afternoon as the upper low passes overhead. Timing this is low
confidence. Have a mention of VCSH thinking -RA will be more
scattered in nature at the terminals.
&&
.TOP Watches/Warnings/Advisories...NONE.
&&
$$
SHORT TERM...53
LONG TERM...Omitt
AVIATION...Wolters
AREA FORECAST DISCUSSION
NWS JACKSON KY
1001 PM EST THU DEC 24 2015
.UPDATE...
ISSUED AT 1001 PM EST THU DEC 24 2015
WE HAVE SEEN MOSTLY CLEAR SKIES IN MANY LOCATIONS THIS EVENING AND
GIVEN THE RECENT RAINFALL AT LEAST SOME PATCHY VALLEY FOG WILL BE
POSSIBLE. THIS HAS ALSO LEAD TO DIFFICULT TEMP CURVE THIS
EVENING...GIVEN THE QUICK DROPS INTO THE LOWER 50S IN THOSE DEEPER
VALLEY SPOTS DUE TO THE DECOUPLING. SEEMS LIKE THE MOSGUIDE WAS
HANDLING VALLEYS BETTER OVERALL...WHILE THE MODEL BLEND SEEMED TO
TO BETTER ELSEWHERE. UPDATED GRIDS TO REFLECT THIS OVERALL
THINKING OF INTRODUCING VALLEY FOG AND ADJUSTING TEMPS/DEWS/WINDS
WITH LATEST OBS/TRENDS.
UPDATE ISSUED AT 710 PM EST THU DEC 24 2015
THIS EVENING QUSI STATIONARY BOUNDARY IS ANALYZED AROUND EASTERN
KY THEN BACK TO OUR SW ACROSS THE SOUTHERN MISSISSIPPI RIVER
VALLEY. WE ARE SEEING SOME MAINLY HIGH CLOUDS ACROSS A GOOD
PORTION OF THE REGION BASED ON OBS AND SAT TONIGHT WITH BEST
COVERAGE TO SOUTH AND EAST. THESE CLOUDS WILL BEGIN TO THICKEN
OVERNIGHT. WHILE WE REMAIN WELL ABOVE NORMAL WITH DEEP SOUTH TO SW
FLOW ACROSS THE REGION THIS CHRISTMAS EVE...THE DEEPER VALLEYS
WILL OR ALREADY HAVE MANAGED TO DECOUPLE TONIGHT...WITH QUICKSAND
AND PAINTSVILLE MESONETS ALREADY DROPPING BELOW THE 60 DEGREE MARK
THIS HOUR. DID UPDATE GRIDS TO CAPTURE THIS A BIT EARLIER...BUT
OTHERWISE GRIDS REMAIN IN GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM EST THU DEC 24 2015
19Z SFC ANALYSIS SHOWS A RELATIVE AREA OF HIGH PRESSURE OVER THE
OHIO VALLEY WHILE LOW PRESSURE IS BUILDING TO THE SOUTHWEST. ON
SATELLITE...A BRIEF PERIOD OF LOW CLOUDS AROUND MIDDAY HAVE
BROKEN UP AND SCATTERED OUT DURING THE EARLY AFTERNOON LEAVING
MOSTLY SUNNY CONDITIONS. THAT SUNSHINE...AND SOME LIMITED
DRYING...RESULTED IN TEMPERATURES SPIKING INTO THE UPPER 60S AND
LOWER 70S THROUGH EAST KENTUCKY THIS AFTERNOON. DEWPOINTS HAVE
FALLEN INTO THE LOW AND MID 50S..BUT ARE STILL VERY HIGH FOR THIS
TIME OF YEAR. MEANWHILE...WINDS ARE LIGHT AND VARIABLE THROUGH THE
AREA...GENERALLY FROM THE SOUTH FOR LOCATIONS SOUTH OF THE
MOUNTAIN PARKWAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE LONGWAVE PATTERN
AS THEY ALL SHOW THE SOUTHEAST RIDGE STRENGTHENING AND WOBBLING
WEST INTO FRIDAY WHILE LARGE AND FAIRLY STRONG TROUGHING DIVES
INTO THE DESERT SOUTHWEST. THIS WILL ALL SERVE TO STRENGTHEN THE
BROAD AND DEEP SOUTHWEST FLOW THROUGH THE REGION INTO SATURDAY
MORNING. WHILE THE MAJORITY OF THE ENERGY IN THIS PATTERN WILL
STAY WITH THE WESTERN TROUGH...THERE WILL BE A FEW WEAK WAVES THAT
RIDE OVER THE AREA DURING THE SHORT TERM PORTION OF THE FORECAST.
OF MOST SIGNIFICANCE WILL BE THE RECORD OR NEAR RECORD HIGH PW
AIR IN PLACE OVER THE REGION DURING THE DAY FRIDAY INTO
SATURDAY...THAT THE MODELS ARE PRETTY MUCH IN CONCURRENCE WITH.
AS SUCH...WILL FOLLOW A BLENDED MODEL SOLUTION FAVORING THE HIGHER
RESOLUTION HRRR AND NAM12 ALONG WITH INPUT FROM THE NATIONAL
CENTERS.
SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF OUR VERY WARM
HOLIDAY PERIOD WITH TEMPERATURES NOT FALLING TOO FAR INTO THE 50S
FOR MOST SPOTS TONIGHT. ALTHOUGH...AM EXPECTING A BIT OF A RIDGE
TO VALLEY TEMPERATURE SPLIT THIS EVENING AND INTO THE FIRST PART
OF THE OVERNIGHT. THIS SHOULD BE MOST NOTICEABLE IN THE FAR
EASTERN SHELTERED VALLEYS AND IS EXPECTED TO MIX OUT TOWARDS DAWN.
THE NEXT SURGE IN PCPN WILL LIKELY MOVE IN FROM THE SOUTHWEST
AROUND DAWN AS WELL AND OVERSPREAD THE ENTIRE CWA BY MID MORNING.
EXPECT LIGHT TO MODERATE SHOWERS ALONG WITH A POTENTIAL FOR
THUNDERSTORMS INTO THE DAY FRIDAY AS AN INVERTED TROUGH/SFC WAVE
MOVES THROUGH KENTUCKY. THIS WILL ACTIVATE THE HIGH MOISTURE
CONTENT IN PLACE AND COULD LEAD TO TRAINING ISSUES IN A FEW
SPOTS...PARTICULARLY THOSE THAT MAY HAVE SEEN SATURATING TO HEAVY
RAINS OVER THE PAST DAY OR SO. DO EXPECT THE HIGHEST RAINFALL
TOTALS THROUGH SATURDAY MORNING TO FALL OVER THE CUMBERLAND
VALLEY BEFORE THE RESPONSIBLE WAVE PULLS OUT OF THE AREA EARLY
SATURDAY. GIVEN THE POTENTIAL HAVE DECIDED TO ISSUE A FLOOD WATCH
STARTING AT 6 AM FRIDAY AND RUNNING THROUGH 8 AM SATURDAY...WITH
BETWEEN 1.5 AND 2.5 INCHES OF RAIN POSSIBLE DURING THIS TIME
FRAME. THIS WATCH WILL COVER POINTS GENERALLY SOUTH OF INTERSTATE
64. CONFIDENCE IS FAIRLY HIGH THAT A GOOD SWATH OF RAIN WILL FALL
OVER A GOOD PORTION OF THE CWA DURING THIS TIME...BUT LOW FOR ANY
PARTICULAR PLACEMENT GIVEN SOME DISCREPANCIES WITH THE HIGHEST
AXIS OF QPF FROM EACH MODEL. IN ADDITION...THE CONCERN FOR HEAVY
RAIN WILL RUN INTO THE NEW WEEK AND FOR THAT OVERARCHING RAINFALL
THREAT WILL ISSUE AN ESF.
FOR TEMPERATURES AND DEWPOINTS...HAVE MAINLY GONE WITH THE
SHORTBLEND GUIDANCE THROUGH FRIDAY MORNING AND THEN THE SUPERBLEND
INTO SATURDAY MORNING. DID MAKE SOME NEAR TERM ADJUSTMENTS INTO
THE FIRST PART OF THE NIGHT FOR A PARTIAL AND BRIEF RIDGE TO
VALLEY TEMPERATURE SPLIT. NOT EXPECTING MUCH OF A DIFFERENCE IN
TEMPS FRIDAY NIGHT GIVEN THE PCPN. AS FOR POPS...ENDED UP ON THE
HIGH SIDE OF GUIDANCE THROUGH THE PERIOD...ESPECIALLY TONIGHT AT
LOZ WHERE THE WETTER MET NUMBERS WERE PREFERRED.
WHILE RECORD HIGH MINIMUM TEMPERATURES ARE EXPECTED BOTH TONIGHT
AND FRIDAY NIGHT...HIGH TEMPERATURE RECORDS FOR TOMORROW WILL
LIKELY NOT FALL DUE TO A VERY WARM CHRISTMAS BACK IN 1982.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EST THU DEC 24 2015
THE MAIN CONCERN FOR THIS PERIOD WILL BE THE POTENTIAL FOR
REPEATING ROUNDS OF RAINFALL THROUGH EARLY NEXT WEEK WITH A DEEP
AND MOISTURE LADEN SOUTHWEST FLOW IN PLACE ALOFT. A WAVY FRONTAL
BOUNDARY WILL LIFT NORTHWARD ACROSS OUR AREA ON SATURDAY ALLOWING
FOR A BREAK IN THE RAINFALL FOR MOST OF EASTERN KENTUCKY FROM
SATURDAY AFTERNOON THROUGH SUNDAY MORNING. FOR THIS REASON...THE
FLOOD WATCH ISSUED WILL ONLY RUN THROUGH AROUND DAWN ON SATURDAY.
HOWEVER...DEEPENING LOW PRESSURE WILL DRIVE NORTHEASTWARD OUT OF
TEXAS LATE IN THE WEEKEND INTO THE DAY ON MONDAY AND THIS WILL
SEND THE FRONT AND A LOAD OF MOISTURE BACK ACROSS THE REGION
BEGINNING SUNDAY AFTERNOON AND LASTING THROUGH MONDAY NIGHT. A
COUPLE OF INCHES OF ADDITIONAL RAINFALL IS LIKELY DURING THIS SECOND
WAVE OF RAIN...WHICH WILL LIKELY CAUSE ADDITIONAL FLOOD CONCERNS.
THIS SYSTEM WILL EXIT TO OUR EAST WITH DIMINISHING RAIN CHANCES ON
TUESDAY.
THE OTHER STORY TO TOUCH ON IS THE UNSEASONABLE WARMTH. PROGGED
850 MB TEMPS ON SATURDAY OF AROUND 15C ARE CLOSE TO RECORD HIGHS
ACCORDING TO SPC SOUNDING CLIMATOLOGY. HIGH TEMPS ARE FORECAST TO
EASILY ECLIPSE RECORDS SATURDAY BY CLIMBING INTO THE LOW TO MID
70S. THIS MAY BE CONSERVATIVE IF CLOUDS SCATTER OUT FOR ANY LENGTH
OF TIME. TEMPS ON SUNDAY WILL AGAIN THREATEN RECORDS AS THEY CLIMB
TO AROUND 70 SOUTH OF I-64...BEFORE A COOLER BUT STILL ABOVE NORMAL
AIRMASS FILTERS IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK. IF
OUR FORECAST PANS OUT THROUGH DECEMBER 31ST...THIS WILL EASILY BE
THE WARMEST DECEMBER ON RECORD AT BOTH JKL AND LOZ. IN FACT...OUR
AVERAGE TEMPERATURE THIS DECEMBER AT JKL AND LOZ WILL LIKELY BE A
COUPLE DEGREES WARMER THAN THE AVERAGE NOVEMBER TEMPERATURE AT
THOSE SITES WHEN ALL IS SAID AND DONE!
BEYOND TUESDAY...FORECAST MODELS KEEP US IN SOUTHWEST FLOW ALOFT
WITH ANOTHER SHORTWAVE PROGGED TO BRING ANOTHER ROUND OF SHOWERS
WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY A RETURN TO MORE
SEASONAL TEMPERATURES BY NEW YEARS EVE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 642 PM EST THU DEC 24 2015
VFR IS THE STORY TO BEGIN THE TAF PERIOD...BUT A FEW PASSING 2 TO
5 KFT CLOUDS WILL BE POSSIBLE PARTICULARLY IN THE SE. THEN EYES
WILL TURN TO A DEVELOPING STORM SYSTEM TO OUR SW. RAIN SHOWERS
AND THUNDERSTORMS WILL DEVELOP AND PROGRESS ACROSS EASTERN KY BY
TOMORROW MORNING AND CONTINUE THROUGH THE DAY. THE BEST CHANCES OF
RAIN AND STORMS WILL BE GENERALLY SOUTH OF SITE SYM...SO DID KEEP
THEM -SHRA VCTS BUT BRING -RA VCTS TO OTHER SITES. FORECAST
SOUNDINGS AND LAMP PROBS ALL SUGGEST LOWERING TO AT LEAST IFR CIGS
BY TOMORROW AFTERNOON SO ADDED THIS ACCORDINGLY. WINDS WILL REMAIN
LIGHT THROUGH THE TAF PERIOD GENERALLY 5 TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM 6 AM EST FRIDAY THROUGH SATURDAY MORNING FOR
KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
710 PM EST THU DEC 24 2015
.UPDATE...
ISSUED AT 710 PM EST THU DEC 24 2015
THIS EVENING QUSI STATIONARY BOUNDARY IS ANALYZED AROUND EASTERN
KY THEN BACK TO OUR SW ACROSS THE SOUTHERN MISSISSIPPI RIVER
VALLEY. WE ARE SEEING SOME MAINLY HIGH CLOUDS ACROSS A GOOD
PORTION OF THE REGION BASED ON OBS AND SAT TONIGHT WITH BEST
COVERAGE TO SOUTH AND EAST. THESE CLOUDS WILL BEGIN TO THICKEN
OVERNIGHT. WHILE WE REMAIN WELL ABOVE NORMAL WITH DEEP SOUTH TO SW
FLOW ACROSS THE REGION THIS CHRISTMAS EVE...THE DEEPER VALLEYS
WILL OR ALREADY HAVE MANAGED TO DECOUPLE TONIGHT...WITH QUICKSAND
AND PAINTSVILLE MESONETS ALREADY DROPPING BELOW THE 60 DEGREE MARK
THIS HOUR. DID UPDATE GRIDS TO CAPTURE THIS A BIT EARLIER...BUT
OTHERWISE GRIDS REMAIN IN GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM EST THU DEC 24 2015
19Z SFC ANALYSIS SHOWS A RELATIVE AREA OF HIGH PRESSURE OVER THE
OHIO VALLEY WHILE LOW PRESSURE IS BUILDING TO THE SOUTHWEST. ON
SATELLITE...A BRIEF PERIOD OF LOW CLOUDS AROUND MIDDAY HAVE
BROKEN UP AND SCATTERED OUT DURING THE EARLY AFTERNOON LEAVING
MOSTLY SUNNY CONDITIONS. THAT SUNSHINE...AND SOME LIMITED
DRYING...RESULTED IN TEMPERATURES SPIKING INTO THE UPPER 60S AND
LOWER 70S THROUGH EAST KENTUCKY THIS AFTERNOON. DEWPOINTS HAVE
FALLEN INTO THE LOW AND MID 50S..BUT ARE STILL VERY HIGH FOR THIS
TIME OF YEAR. MEANWHILE...WINDS ARE LIGHT AND VARIABLE THROUGH THE
AREA...GENERALLY FROM THE SOUTH FOR LOCATIONS SOUTH OF THE
MOUNTAIN PARKWAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE LONGWAVE PATTERN
AS THEY ALL SHOW THE SOUTHEAST RIDGE STRENGTHENING AND WOBBLING
WEST INTO FRIDAY WHILE LARGE AND FAIRLY STRONG TROUGHING DIVES
INTO THE DESERT SOUTHWEST. THIS WILL ALL SERVE TO STRENGTHEN THE
BROAD AND DEEP SOUTHWEST FLOW THROUGH THE REGION INTO SATURDAY
MORNING. WHILE THE MAJORITY OF THE ENERGY IN THIS PATTERN WILL
STAY WITH THE WESTERN TROUGH...THERE WILL BE A FEW WEAK WAVES THAT
RIDE OVER THE AREA DURING THE SHORT TERM PORTION OF THE FORECAST.
OF MOST SIGNIFICANCE WILL BE THE RECORD OR NEAR RECORD HIGH PW
AIR IN PLACE OVER THE REGION DURING THE DAY FRIDAY INTO
SATURDAY...THAT THE MODELS ARE PRETTY MUCH IN CONCURRENCE WITH.
AS SUCH...WILL FOLLOW A BLENDED MODEL SOLUTION FAVORING THE HIGHER
RESOLUTION HRRR AND NAM12 ALONG WITH INPUT FROM THE NATIONAL
CENTERS.
SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF OUR VERY WARM
HOLIDAY PERIOD WITH TEMPERATURES NOT FALLING TOO FAR INTO THE 50S
FOR MOST SPOTS TONIGHT. ALTHOUGH...AM EXPECTING A BIT OF A RIDGE
TO VALLEY TEMPERATURE SPLIT THIS EVENING AND INTO THE FIRST PART
OF THE OVERNIGHT. THIS SHOULD BE MOST NOTICEABLE IN THE FAR
EASTERN SHELTERED VALLEYS AND IS EXPECTED TO MIX OUT TOWARDS DAWN.
THE NEXT SURGE IN PCPN WILL LIKELY MOVE IN FROM THE SOUTHWEST
AROUND DAWN AS WELL AND OVERSPREAD THE ENTIRE CWA BY MID MORNING.
EXPECT LIGHT TO MODERATE SHOWERS ALONG WITH A POTENTIAL FOR
THUNDERSTORMS INTO THE DAY FRIDAY AS AN INVERTED TROUGH/SFC WAVE
MOVES THROUGH KENTUCKY. THIS WILL ACTIVATE THE HIGH MOISTURE
CONTENT IN PLACE AND COULD LEAD TO TRAINING ISSUES IN A FEW
SPOTS...PARTICULARLY THOSE THAT MAY HAVE SEEN SATURATING TO HEAVY
RAINS OVER THE PAST DAY OR SO. DO EXPECT THE HIGHEST RAINFALL
TOTALS THROUGH SATURDAY MORNING TO FALL OVER THE CUMBERLAND
VALLEY BEFORE THE RESPONSIBLE WAVE PULLS OUT OF THE AREA EARLY
SATURDAY. GIVEN THE POTENTIAL HAVE DECIDED TO ISSUE A FLOOD WATCH
STARTING AT 6 AM FRIDAY AND RUNNING THROUGH 8 AM SATURDAY...WITH
BETWEEN 1.5 AND 2.5 INCHES OF RAIN POSSIBLE DURING THIS TIME
FRAME. THIS WATCH WILL COVER POINTS GENERALLY SOUTH OF INTERSTATE
64. CONFIDENCE IS FAIRLY HIGH THAT A GOOD SWATH OF RAIN WILL FALL
OVER A GOOD PORTION OF THE CWA DURING THIS TIME...BUT LOW FOR ANY
PARTICULAR PLACEMENT GIVEN SOME DISCREPANCIES WITH THE HIGHEST
AXIS OF QPF FROM EACH MODEL. IN ADDITION...THE CONCERN FOR HEAVY
RAIN WILL RUN INTO THE NEW WEEK AND FOR THAT OVERARCHING RAINFALL
THREAT WILL ISSUE AN ESF.
FOR TEMPERATURES AND DEWPOINTS...HAVE MAINLY GONE WITH THE
SHORTBLEND GUIDANCE THROUGH FRIDAY MORNING AND THEN THE SUPERBLEND
INTO SATURDAY MORNING. DID MAKE SOME NEAR TERM ADJUSTMENTS INTO
THE FIRST PART OF THE NIGHT FOR A PARTIAL AND BRIEF RIDGE TO
VALLEY TEMPERATURE SPLIT. NOT EXPECTING MUCH OF A DIFFERENCE IN
TEMPS FRIDAY NIGHT GIVEN THE PCPN. AS FOR POPS...ENDED UP ON THE
HIGH SIDE OF GUIDANCE THROUGH THE PERIOD...ESPECIALLY TONIGHT AT
LOZ WHERE THE WETTER MET NUMBERS WERE PREFERRED.
WHILE RECORD HIGH MINIMUM TEMPERATURES ARE EXPECTED BOTH TONIGHT
AND FRIDAY NIGHT...HIGH TEMPERATURE RECORDS FOR TOMORROW WILL
LIKELY NOT FALL DUE TO A VERY WARM CHRISTMAS BACK IN 1982.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EST THU DEC 24 2015
THE MAIN CONCERN FOR THIS PERIOD WILL BE THE POTENTIAL FOR
REPEATING ROUNDS OF RAINFALL THROUGH EARLY NEXT WEEK WITH A DEEP
AND MOISTURE LADEN SOUTHWEST FLOW IN PLACE ALOFT. A WAVY FRONTAL
BOUNDARY WILL LIFT NORTHWARD ACROSS OUR AREA ON SATURDAY ALLOWING
FOR A BREAK IN THE RAINFALL FOR MOST OF EASTERN KENTUCKY FROM
SATURDAY AFTERNOON THROUGH SUNDAY MORNING. FOR THIS REASON...THE
FLOOD WATCH ISSUED WILL ONLY RUN THROUGH AROUND DAWN ON SATURDAY.
HOWEVER...DEEPENING LOW PRESSURE WILL DRIVE NORTHEASTWARD OUT OF
TEXAS LATE IN THE WEEKEND INTO THE DAY ON MONDAY AND THIS WILL
SEND THE FRONT AND A LOAD OF MOISTURE BACK ACROSS THE REGION
BEGINNING SUNDAY AFTERNOON AND LASTING THROUGH MONDAY NIGHT. A
COUPLE OF INCHES OF ADDITIONAL RAINFALL IS LIKELY DURING THIS SECOND
WAVE OF RAIN...WHICH WILL LIKELY CAUSE ADDITIONAL FLOOD CONCERNS.
THIS SYSTEM WILL EXIT TO OUR EAST WITH DIMINISHING RAIN CHANCES ON
TUESDAY.
THE OTHER STORY TO TOUCH ON IS THE UNSEASONABLE WARMTH. PROGGED
850 MB TEMPS ON SATURDAY OF AROUND 15C ARE CLOSE TO RECORD HIGHS
ACCORDING TO SPC SOUNDING CLIMATOLOGY. HIGH TEMPS ARE FORECAST TO
EASILY ECLIPSE RECORDS SATURDAY BY CLIMBING INTO THE LOW TO MID
70S. THIS MAY BE CONSERVATIVE IF CLOUDS SCATTER OUT FOR ANY LENGTH
OF TIME. TEMPS ON SUNDAY WILL AGAIN THREATEN RECORDS AS THEY CLIMB
TO AROUND 70 SOUTH OF I-64...BEFORE A COOLER BUT STILL ABOVE NORMAL
AIRMASS FILTERS IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK. IF
OUR FORECAST PANS OUT THROUGH DECEMBER 31ST...THIS WILL EASILY BE
THE WARMEST DECEMBER ON RECORD AT BOTH JKL AND LOZ. IN FACT...OUR
AVERAGE TEMPERATURE THIS DECEMBER AT JKL AND LOZ WILL LIKELY BE A
COUPLE DEGREES WARMER THAN THE AVERAGE NOVEMBER TEMPERATURE AT
THOSE SITES WHEN ALL IS SAID AND DONE!
BEYOND TUESDAY...FORECAST MODELS KEEP US IN SOUTHWEST FLOW ALOFT
WITH ANOTHER SHORTWAVE PROGGED TO BRING ANOTHER ROUND OF SHOWERS
WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY A RETURN TO MORE
SEASONAL TEMPERATURES BY NEW YEARS EVE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 642 PM EST THU DEC 24 2015
VFR IS THE STORY TO BEGIN THE TAF PERIOD...BUT A FEW PASSING 2 TO
5 KFT CLOUDS WILL BE POSSIBLE PARTICULARLY IN THE SE. THEN EYES
WILL TURN TO A DEVELOPING STORM SYSTEM TO OUR SW. RAIN SHOWERS
AND THUNDERSTORMS WILL DEVELOP AND PROGRESS ACROSS EASTERN KY BY
TOMORROW MORNING AND CONTINUE THROUGH THE DAY. THE BEST CHANCES OF
RAIN AND STORMS WILL BE GENERALLY SOUTH OF SITE SYM...SO DID KEEP
THEM -SHRA VCTS BUT BRING -RA VCTS TO OTHER SITES. FORECAST
SOUNDINGS AND LAMP PROBS ALL SUGGEST LOWERING TO AT LEAST IFR CIGS
BY TOMORROW AFTERNOON SO ADDED THIS ACCORDINGLY. WINDS WILL REMAIN
LIGHT THROUGH THE TAF PERIOD GENERALLY 5 TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM 6 AM EST FRIDAY THROUGH SATURDAY MORNING FOR
KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
642 PM EST THU DEC 24 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM EST THU DEC 24 2015
19Z SFC ANALYSIS SHOWS A RELATIVE AREA OF HIGH PRESSURE OVER THE
OHIO VALLEY WHILE LOW PRESSURE IS BUILDING TO THE SOUTHWEST. ON
SATELLITE...A BRIEF PERIOD OF LOW CLOUDS AROUND MIDDAY HAVE
BROKEN UP AND SCATTERED OUT DURING THE EARLY AFTERNOON LEAVING
MOSTLY SUNNY CONDITIONS. THAT SUNSHINE...AND SOME LIMITED
DRYING...RESULTED IN TEMPERATURES SPIKING INTO THE UPPER 60S AND
LOWER 70S THROUGH EAST KENTUCKY THIS AFTERNOON. DEWPOINTS HAVE
FALLEN INTO THE LOW AND MID 50S..BUT ARE STILL VERY HIGH FOR THIS
TIME OF YEAR. MEANWHILE...WINDS ARE LIGHT AND VARIABLE THROUGH THE
AREA...GENERALLY FROM THE SOUTH FOR LOCATIONS SOUTH OF THE
MOUNTAIN PARKWAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE LONGWAVE PATTERN
AS THEY ALL SHOW THE SOUTHEAST RIDGE STRENGTHENING AND WOBBLING
WEST INTO FRIDAY WHILE LARGE AND FAIRLY STRONG TROUGHING DIVES
INTO THE DESERT SOUTHWEST. THIS WILL ALL SERVE TO STRENGTHEN THE
BROAD AND DEEP SOUTHWEST FLOW THROUGH THE REGION INTO SATURDAY
MORNING. WHILE THE MAJORITY OF THE ENERGY IN THIS PATTERN WILL
STAY WITH THE WESTERN TROUGH...THERE WILL BE A FEW WEAK WAVES THAT
RIDE OVER THE AREA DURING THE SHORT TERM PORTION OF THE FORECAST.
OF MOST SIGNIFICANCE WILL BE THE RECORD OR NEAR RECORD HIGH PW
AIR IN PLACE OVER THE REGION DURING THE DAY FRIDAY INTO
SATURDAY...THAT THE MODELS ARE PRETTY MUCH IN CONCURRENCE WITH.
AS SUCH...WILL FOLLOW A BLENDED MODEL SOLUTION FAVORING THE HIGHER
RESOLUTION HRRR AND NAM12 ALONG WITH INPUT FROM THE NATIONAL
CENTERS.
SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF OUR VERY WARM
HOLIDAY PERIOD WITH TEMPERATURES NOT FALLING TOO FAR INTO THE 50S
FOR MOST SPOTS TONIGHT. ALTHOUGH...AM EXPECTING A BIT OF A RIDGE
TO VALLEY TEMPERATURE SPLIT THIS EVENING AND INTO THE FIRST PART
OF THE OVERNIGHT. THIS SHOULD BE MOST NOTICEABLE IN THE FAR
EASTERN SHELTERED VALLEYS AND IS EXPECTED TO MIX OUT TOWARDS DAWN.
THE NEXT SURGE IN PCPN WILL LIKELY MOVE IN FROM THE SOUTHWEST
AROUND DAWN AS WELL AND OVERSPREAD THE ENTIRE CWA BY MID MORNING.
EXPECT LIGHT TO MODERATE SHOWERS ALONG WITH A POTENTIAL FOR
THUNDERSTORMS INTO THE DAY FRIDAY AS AN INVERTED TROUGH/SFC WAVE
MOVES THROUGH KENTUCKY. THIS WILL ACTIVATE THE HIGH MOISTURE
CONTENT IN PLACE AND COULD LEAD TO TRAINING ISSUES IN A FEW
SPOTS...PARTICULARLY THOSE THAT MAY HAVE SEEN SATURATING TO HEAVY
RAINS OVER THE PAST DAY OR SO. DO EXPECT THE HIGHEST RAINFALL
TOTALS THROUGH SATURDAY MORNING TO FALL OVER THE CUMBERLAND
VALLEY BEFORE THE RESPONSIBLE WAVE PULLS OUT OF THE AREA EARLY
SATURDAY. GIVEN THE POTENTIAL HAVE DECIDED TO ISSUE A FLOOD WATCH
STARTING AT 6 AM FRIDAY AND RUNNING THROUGH 8 AM SATURDAY...WITH
BETWEEN 1.5 AND 2.5 INCHES OF RAIN POSSIBLE DURING THIS TIME
FRAME. THIS WATCH WILL COVER POINTS GENERALLY SOUTH OF INTERSTATE
64. CONFIDENCE IS FAIRLY HIGH THAT A GOOD SWATH OF RAIN WILL FALL
OVER A GOOD PORTION OF THE CWA DURING THIS TIME...BUT LOW FOR ANY
PARTICULAR PLACEMENT GIVEN SOME DISCREPANCIES WITH THE HIGHEST
AXIS OF QPF FROM EACH MODEL. IN ADDITION...THE CONCERN FOR HEAVY
RAIN WILL RUN INTO THE NEW WEEK AND FOR THAT OVERARCHING RAINFALL
THREAT WILL ISSUE AN ESF.
FOR TEMPERATURES AND DEWPOINTS...HAVE MAINLY GONE WITH THE
SHORTBLEND GUIDANCE THROUGH FRIDAY MORNING AND THEN THE SUPERBLEND
INTO SATURDAY MORNING. DID MAKE SOME NEAR TERM ADJUSTMENTS INTO
THE FIRST PART OF THE NIGHT FOR A PARTIAL AND BRIEF RIDGE TO
VALLEY TEMPERATURE SPLIT. NOT EXPECTING MUCH OF A DIFFERENCE IN
TEMPS FRIDAY NIGHT GIVEN THE PCPN. AS FOR POPS...ENDED UP ON THE
HIGH SIDE OF GUIDANCE THROUGH THE PERIOD...ESPECIALLY TONIGHT AT
LOZ WHERE THE WETTER MET NUMBERS WERE PREFERRED.
WHILE RECORD HIGH MINIMUM TEMPERATURES ARE EXPECTED BOTH TONIGHT
AND FRIDAY NIGHT...HIGH TEMPERATURE RECORDS FOR TOMORROW WILL
LIKELY NOT FALL DUE TO A VERY WARM CHRISTMAS BACK IN 1982.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EST THU DEC 24 2015
THE MAIN CONCERN FOR THIS PERIOD WILL BE THE POTENTIAL FOR
REPEATING ROUNDS OF RAINFALL THROUGH EARLY NEXT WEEK WITH A DEEP
AND MOISTURE LADEN SOUTHWEST FLOW IN PLACE ALOFT. A WAVY FRONTAL
BOUNDARY WILL LIFT NORTHWARD ACROSS OUR AREA ON SATURDAY ALLOWING
FOR A BREAK IN THE RAINFALL FOR MOST OF EASTERN KENTUCKY FROM
SATURDAY AFTERNOON THROUGH SUNDAY MORNING. FOR THIS REASON...THE
FLOOD WATCH ISSUED WILL ONLY RUN THROUGH AROUND DAWN ON SATURDAY.
HOWEVER...DEEPENING LOW PRESSURE WILL DRIVE NORTHEASTWARD OUT OF
TEXAS LATE IN THE WEEKEND INTO THE DAY ON MONDAY AND THIS WILL
SEND THE FRONT AND A LOAD OF MOISTURE BACK ACROSS THE REGION
BEGINNING SUNDAY AFTERNOON AND LASTING THROUGH MONDAY NIGHT. A
COUPLE OF INCHES OF ADDITIONAL RAINFALL IS LIKELY DURING THIS SECOND
WAVE OF RAIN...WHICH WILL LIKELY CAUSE ADDITIONAL FLOOD CONCERNS.
THIS SYSTEM WILL EXIT TO OUR EAST WITH DIMINISHING RAIN CHANCES ON
TUESDAY.
THE OTHER STORY TO TOUCH ON IS THE UNSEASONABLE WARMTH. PROGGED
850 MB TEMPS ON SATURDAY OF AROUND 15C ARE CLOSE TO RECORD HIGHS
ACCORDING TO SPC SOUNDING CLIMATOLOGY. HIGH TEMPS ARE FORECAST TO
EASILY ECLIPSE RECORDS SATURDAY BY CLIMBING INTO THE LOW TO MID
70S. THIS MAY BE CONSERVATIVE IF CLOUDS SCATTER OUT FOR ANY LENGTH
OF TIME. TEMPS ON SUNDAY WILL AGAIN THREATEN RECORDS AS THEY CLIMB
TO AROUND 70 SOUTH OF I-64...BEFORE A COOLER BUT STILL ABOVE NORMAL
AIRMASS FILTERS IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK. IF
OUR FORECAST PANS OUT THROUGH DECEMBER 31ST...THIS WILL EASILY BE
THE WARMEST DECEMBER ON RECORD AT BOTH JKL AND LOZ. IN FACT...OUR
AVERAGE TEMPERATURE THIS DECEMBER AT JKL AND LOZ WILL LIKELY BE A
COUPLE DEGREES WARMER THAN THE AVERAGE NOVEMBER TEMPERATURE AT
THOSE SITES WHEN ALL IS SAID AND DONE!
BEYOND TUESDAY...FORECAST MODELS KEEP US IN SOUTHWEST FLOW ALOFT
WITH ANOTHER SHORTWAVE PROGGED TO BRING ANOTHER ROUND OF SHOWERS
WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY A RETURN TO MORE
SEASONAL TEMPERATURES BY NEW YEARS EVE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 642 PM EST THU DEC 24 2015
VFR IS THE STORY TO BEGIN THE TAF PERIOD...BUT A FEW PASSING 2 TO
5 KFT CLOUDS WILL BE POSSIBLE PARTICULARLY IN THE SE. THEN EYES
WILL TURN TO A DEVELOPING STORM SYSTEM TO OUR SW. RAIN SHOWERS
AND THUNDERSTORMS WILL DEVELOP AND PROGRESS ACROSS EASTERN KY BY
TOMORROW MORNING AND CONTINUE THROUGH THE DAY. THE BEST CHANCES OF
RAIN AND STORMS WILL BE GENERALLY SOUTH OF SITE SYM...SO DID KEEP
THEM -SHRA VCTS BUT BRING -RA VCTS TO OTHER SITES. FORECAST
SOUNDINGS AND LAMP PROBS ALL SUGGEST LOWERING TO AT LEAST IFR CIGS
BY TOMORROW AFTERNOON SO ADDED THIS ACCORDINGLY. WINDS WILL REMAIN
LIGHT THROUGH THE TAF PERIOD GENERALLY 5 TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM 6 AM EST FRIDAY THROUGH SATURDAY MORNING FOR
KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
356 PM EST WED DEC 23 2015
.UPDATE...
ISSUED AT 217 PM EST WED DEC 23 2015
RAPIDLY MOVING SHOWERS HAVE PUSHED INTO THE SW PART OF THE JKL
FORECAST AREA OUT OF TN...WITH EVEN A FEW SPARSE LIGHTNING
STRIKES. HAVE UPDATED THE FORECAST TO ACCOUNT FOR THIS ACTIVITY
TO MAKE ITS WAY NE ACROSS THE REGION.
UPDATE ISSUED AT 1019 AM EST WED DEC 23 2015
SHOWERS ARE DIMINISHING LATE THIS MORNING AS THE AREA OF PRECIP
EXITS TO THE EAST. THERE IS A SIZABLE HOLE IN THE ACTIVITY
UPSTREAM TO OUR WEST AND SOUTHWEST. MODEL FORECAST SOUNDINGS
SUGGEST THIS WILL PERSIST OVER THE JKL FORECAST AREA AS IT
PROPAGATES THROUGH...WITH MID/UPPER LEVEL DRYING TAKING PLACE AS A
LOW LEVEL CAP PERSISTS. DEEP CONVECTION COULD BEGIN TO SHOW UP
FROM THE WEST BY THE END OF THE DAY.
UPDATE ISSUED AT 654 AM EST WED DEC 23 2015
SHOWERS NOW EXPANDING ACROSS THE AREA AS THE WARM FRONT LIFTS
NORTH. LOOKS LIKE MOST OF THE RAIN WILL OCCUR IN THE NEXT FEW
HOURS...BUT A FEW SHOWERS WILL REMAIN POSSIBLE INTO THE EARLY
AFTERNOON HOURS AS A MOIST ENVIRONMENT REMAINS OVER THE AREA.
LOOKS LIKE THE SEVERE STORMS SHOULD BE KNOCKING ON OUR DOOR
SHORTLY AFTER 9 PM THIS EVENING. OUR FORECAST GRAPHICAL TIMING
LOOKS EXCELLENT RIGHT NOW.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 343 AM EST WED DEC 23 2015
...SEVERE STORMS WITH DAMAGING WINDS POSSIBLE TONIGHT...
A RATHER ACTIVE...SPRING-LIKE PATTERN EXPECTED OVER THE NEXT 36
HOURS. PRESENTLY...A WARM FRONT IS LIFTING NORTH ACROSS TENNESSEE.
SOUTHEAST WINDS TO THE NORTH OF THE FRONT HAS KEPT MUCH OF EASTERN
KENTUCKY DRY OVERNIGHT. HOWEVER...THIS IS ABOUT TO CHANGE AS THE
FRONT CONTINUES TO PUSH NORTH THIS MORNING AND WINDS TURN MORE
SOUTHERLY. THE INITIAL SURGE OF MID LEVEL ISENTROPIC ASCENT HAS
GENERATED A LARGER POCKET OF RAINFALL OVER THE CUMBERLAND
PLATEAU...AND THIS RAIN WILL MOVE NORTH ACROSS OUR WESTERN
COUNTIES THROUGH 7 AM. INCREASED POPS TO CATEGORICAL WITH THIS
RAIN SPREADING NORTH. TO THE EAST...WE SHOULD REMAIN WITH VERY
LITTLE AS THE DOWNSLOPING CONTINUES TO EAT AWAY AT SHOWERS TRYING
TO PUSH NORTH. EVENTUALLY THE DRY AIR WILL BE OVERCOME...LIKELY
AROUND OR SHORTLY AFTER 7 AM...WITH SCATTERED SHOWERS PUSHING
NORTH ACROSS THE REGION THROUGH THE MORNING. HRRR HAS BEEN
CONSISTENT ON LINGERING SHOWERS INTO THE AFTERNOON...SO HAVE
KEPT POPS IN THE FORECAST THROUGH EARLY AFTERNOON. IT DOES APPEAR
WE SHOULD SEE A BETTER BREAK IN PRECIPITATION BY LATE AFTERNOON
THROUGH THE EARLY EVENING HOURS..AS SUBSIDENCE SPREADS IN AHEAD OF
THE APPROACHING COLD FRONT.
WITH THE FRONT APPROACHING THIS AFTERNOON...THE GRADIENT SHOULD
INCREASE AND WE WILL SEE GUSTY WINDS DEVELOP AREA WIDE. THE NAM
BUFKIT MOMENTUM TRANSFER EQUATION SUPPORTS 3O TO 35 MPH WIND
GUSTS...ESPECIALLY OUT ACROSS CENTRAL KENTUCKY...EXTENDING ACROSS
THE BLUEGRASS. WIND GUSTS UP TO 25 WILL REMAIN POSSIBLE TO THE
EAST. PUT IN A MENTION IN THE HWO OF THE GUSTY WINDS THIS
AFTERNOON.
FINALLY...MOVING ONTO THE SEVERE POTENTIAL TONIGHT. MODELS ARE
STILL NOT IN GREAT AGREEMENT ON OVERALL TIMING...AS A FEW OF THE
HI-RES MODELS SUPPORT AN EARLIER ROUND OF CONVECTION IN THE
EVENING...WHILE OTHERS HOLD OFF UNTIL OVERNIGHT. THUS...CONFIDENCE
IS HIGH ON THE THREAT FOR SEVERE STORMS OCCURRING TONIGHT...THERE
REMAINS CONSIDERABLE SPREAD ON WHETHER IT OCCURS MID TO LATE
EVENING OR AFTER MIDNIGHT. REGARDLESS OF TIMING...SHEAR GENERATED
WITH THE STRENGTH OF THE LOW LEVEL JET IS TREMENDOUS AND WILL
SUPPORT THE SEVERE STORM POTENTIAL. THE EXACT QUESTION IS HOW MUCH
INSTABILITY WILL BE PRESENT AS THE STORMS CROSS INTO EASTERN
KENTUCKY TONIGHT. NAM BUFKIT SOUNDINGS SHOW SOME POTENTIAL FOR
600-1000J/KG OF SBCAPE...WHICH IS MARGINAL...BUT COULD BE ENOUGH
TO ALLOW WINDS TO REACH THE SURFACE...ESPECIALLY IF WE END UP
DEALING WITH MORE LINE SEGMENTS. THUS...THE STORM PREDICTION
CENTER HAS EXPANDED THE ENHANCED RISK OF SEVERE STORMS INTO
CENTRAL KENTUCKY. IF WE DO END UP WITH A QLCS/LINE OF STORMS...
A SPIN UP TORNADO WOULD ALSO BE POSSIBLE ALONG THE LINE WITH SUCH
STRONG SHEAR NEARLY NORMAL TO THE ADVANCING STORMS. WILL CONTINUE
TO HIGHLIGHT DAMAGING WINDS/TORNADO THREAT IN THE HWO AND PLAN TO
DO A MORNING WEB BRIEFING TO HIGHLIGHT THE THREAT.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 356 PM EST WED DEC 23 2015
AT UPPER LEVELS...MODELS ARE IN GOOD AGREEMENT WITH THE AMPLIFIED
AND ACTIVE LONG WAVE PATTERN ACROSS THE CONUS THROUGH EARLY NEXT
WEEK. THIS IS DUE TO A BERMUDA HIGH SITTING OVER THE WESTERN
ATLANTIC GRADUALLY SHIFTING TOWARDS THE BAHAMAS BY EARLY NEXT
WEEK. AS THE HIGH PUSHES EAST...THE LONG WAVE PATTERN WILL
TRANSITION TO A SPLIT FLOW SETTING UP DEEP AND BROAD TROUGHING IN
THE WEST HALF OF THE NATION OVER THE HOLIDAY WEEKEND. A CUTOFF LOW
WILL DROP SOUTHEAST INTO TEXAS AND THEN SWING NORTHEAST INTO THE
MISSISSIPPI VALLEY BY EARLY NEXT WEEK...AND THEN EVENTUALLY LIFT
TOWARDS THE GREAT LAKES REGION BY MID WEEK. MODEL SOLUTIONS DIFFER
WITH THE CUTOFF LOW SO THERE IS LOW CONFIDENCE WITH THIS PORTION
OF THE FORECAST.
AT THE SFC...A STALLED FRONTAL BOUNDARY WILL BE LIFTING NORTHWARD
THROUGH OUR AREA FRIDAY MORNING BRINGING A RETURNED SURGE OF LOW
LEVEL MOISTURE. CONFIDENCE REGARDING HOW MUCH RAINFALL WE WILL SEE
FRIDAY INTO FRIDAY NIGHT CONTINUES TO BE ON THE LOW SIDE DUE TO
MODEL DIFFERENCES BETWEEN THE 12Z GFS AND ECMWF. THOUGH THERE WILL
BE PLENTY OF MOISTURE WITH PWATS NEAR 1.5 INCHES...WHICH IS WELL
ABOVE THE 90TH PERCENTILE ACCORDING TO CLIMATOLOGY. SO WILL
CONTINUE TO STICK CLOSE TO CR SUPERBLEND WITH POP CHANCES ON
FRIDAY.
BY SATURDAY MORNING...THE FRONT SHOULD BE SITUATED NORTH OF THE
AREA...OR JUST ON THE FRINGE OF OUR NORTHWEST COUNTIES. THIS
SHOULD ALLOW THINGS TO DRY OUT MAINLY IN OUR SOUTHEAST COUNTIES
FOR A PORTION OF THE WEEKEND...WITH LESSER POP CHANCES IN THE
OTHER PORTIONS OF THE FORECAST AREA. AS THE NEXT SFC WAVE
APPROACHES THE REGION ON MONDAY...RAIN WILL SWEEP ACROSS EASTERN
KENTUCKY AND PERSIST THROUGH TUESDAY MORNING. THE TIMING AND
PRECIP AMOUNTS DIFFER BETWEEN MODELS WITH THE GFS BEING THE FASTER
SOLUTION. THAT BEING SAID...DECIDED TO STAY CLOSE TO THE CR
SUPERBLEND...AND KEPT RAIN CHANCES IN THE FORECAST THROUGH LATE
TUESDAY TO ACCOUNT FOR THE SLOWER SOLUTIONS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 134 PM EST WED DEC 23 2015
VFR PREVAILED AT THE START OF THE PERIOD AND WILL PROBABLY LAST
INTO EARLY THIS EVENING. SOUTH WINDS MAY BE GUSTY AT TIMES THIS
AFTERNOON AND EVENING...WITH GUSTS OF 15 TO 25 MPH. THE STRONGEST
GUSTS ARE EXPECTED WEST OF THE FOOTHILLS. A FEW SHOWERS AND
THUNDERSTORMS COULD SHOW UP LATE IN THE DAY...BUT THEY ARE MORE
LIKELY TO HOLD OFF UNTIL TONIGHT. THE MOST LIKELY ARRIVAL TIME IN
WESTERN AREAS SUCH AS KSME AND KIOB IS BETWEEN ABOUT 03Z-
05Z...WITH PRECIPITATION THEN PROGRESSING EASTWARD ACROSS THE
REMAINDER OF THE STATE BY ABOUT 08Z. MVFR SHOULD ARRIVE SHORTLY
AFTER PRECIPITATION MOVES IN TONIGHT. ALSO...THUNDERSTORMS AND
THE HEAVIEST SHOWERS MAY CONTAIN WIND GUSTS IN EXCESS OF 40 MPH.
PRECIPITATION MAY LAST PAST DAYBREAK ON THURSDAY...ESPECIALLY IN
SOUTHEAST KY. MANY LOCATIONS MAY DETERIORATE TO IFR ON THURSDAY
MORNING...ESPECIALLY IN SOUTHEAST KY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...KAS
LONG TERM...JVM
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
217 PM EST WED DEC 23 2015
.UPDATE...
ISSUED AT 217 PM EST WED DEC 23 2015
RAPIDLY MOVING SHOWERS HAVE PUSHED INTO THE SW PART OF THE JKL
FORECAST AREA OUT OF TN...WITH EVEN A FEW SPARSE LIGHTNING
STRIKES. HAVE UPDATED THE FORECAST TO ACCOUNT FOR THIS ACTIVITY
TO MAKE ITS WAY NE ACROSS THE REGION.
UPDATE ISSUED AT 1019 AM EST WED DEC 23 2015
SHOWERS ARE DIMINISHING LATE THIS MORNING AS THE AREA OF PRECIP
EXITS TO THE EAST. THERE IS A SIZABLE HOLE IN THE ACTIVITY
UPSTREAM TO OUR WEST AND SOUTHWEST. MODEL FORECAST SOUNDINGS
SUGGEST THIS WILL PERSIST OVER THE JKL FORECAST AREA AS IT
PROPAGATES THROUGH...WITH MID/UPPER LEVEL DRYING TAKING PLACE AS A
LOW LEVEL CAP PERSISTS. DEEP CONVECTION COULD BEGIN TO SHOW UP
FROM THE WEST BY THE END OF THE DAY.
UPDATE ISSUED AT 654 AM EST WED DEC 23 2015
SHOWERS NOW EXPANDING ACROSS THE AREA AS THE WARM FRONT LIFTS
NORTH. LOOKS LIKE MOST OF THE RAIN WILL OCCUR IN THE NEXT FEW
HOURS...BUT A FEW SHOWERS WILL REMAIN POSSIBLE INTO THE EARLY
AFTERNOON HOURS AS A MOIST ENVIRONMENT REMAINS OVER THE AREA.
LOOKS LIKE THE SEVERE STORMS SHOULD BE KNOCKING ON OUR DOOR
SHORTLY AFTER 9 PM THIS EVENING. OUR FORECAST GRAPHICAL TIMING
LOOKS EXCELLENT RIGHT NOW.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 343 AM EST WED DEC 23 2015
...SEVERE STORMS WITH DAMAGING WINDS POSSIBLE TONIGHT...
A RATHER ACTIVE...SPRING-LIKE PATTERN EXPECTED OVER THE NEXT 36
HOURS. PRESENTLY...A WARM FRONT IS LIFTING NORTH ACROSS TENNESSEE.
SOUTHEAST WINDS TO THE NORTH OF THE FRONT HAS KEPT MUCH OF EASTERN
KENTUCKY DRY OVERNIGHT. HOWEVER...THIS IS ABOUT TO CHANGE AS THE
FRONT CONTINUES TO PUSH NORTH THIS MORNING AND WINDS TURN MORE
SOUTHERLY. THE INITIAL SURGE OF MID LEVEL ISENTROPIC ASCENT HAS
GENERATED A LARGER POCKET OF RAINFALL OVER THE CUMBERLAND
PLATEAU...AND THIS RAIN WILL MOVE NORTH ACROSS OUR WESTERN
COUNTIES THROUGH 7 AM. INCREASED POPS TO CATEGORICAL WITH THIS
RAIN SPREADING NORTH. TO THE EAST...WE SHOULD REMAIN WITH VERY
LITTLE AS THE DOWNSLOPING CONTINUES TO EAT AWAY AT SHOWERS TRYING
TO PUSH NORTH. EVENTUALLY THE DRY AIR WILL BE OVERCOME...LIKELY
AROUND OR SHORTLY AFTER 7 AM...WITH SCATTERED SHOWERS PUSHING
NORTH ACROSS THE REGION THROUGH THE MORNING. HRRR HAS BEEN
CONSISTENT ON LINGERING SHOWERS INTO THE AFTERNOON...SO HAVE
KEPT POPS IN THE FORECAST THROUGH EARLY AFTERNOON. IT DOES APPEAR
WE SHOULD SEE A BETTER BREAK IN PRECIPITATION BY LATE AFTERNOON
THROUGH THE EARLY EVENING HOURS..AS SUBSIDENCE SPREADS IN AHEAD OF
THE APPROACHING COLD FRONT.
WITH THE FRONT APPROACHING THIS AFTERNOON...THE GRADIENT SHOULD
INCREASE AND WE WILL SEE GUSTY WINDS DEVELOP AREA WIDE. THE NAM
BUFKIT MOMENTUM TRANSFER EQUATION SUPPORTS 3O TO 35 MPH WIND
GUSTS...ESPECIALLY OUT ACROSS CENTRAL KENTUCKY...EXTENDING ACROSS
THE BLUEGRASS. WIND GUSTS UP TO 25 WILL REMAIN POSSIBLE TO THE
EAST. PUT IN A MENTION IN THE HWO OF THE GUSTY WINDS THIS
AFTERNOON.
FINALLY...MOVING ONTO THE SEVERE POTENTIAL TONIGHT. MODELS ARE
STILL NOT IN GREAT AGREEMENT ON OVERALL TIMING...AS A FEW OF THE
HI-RES MODELS SUPPORT AN EARLIER ROUND OF CONVECTION IN THE
EVENING...WHILE OTHERS HOLD OFF UNTIL OVERNIGHT. THUS...CONFIDENCE
IS HIGH ON THE THREAT FOR SEVERE STORMS OCCURRING TONIGHT...THERE
REMAINS CONSIDERABLE SPREAD ON WHETHER IT OCCURS MID TO LATE
EVENING OR AFTER MIDNIGHT. REGARDLESS OF TIMING...SHEAR GENERATED
WITH THE STRENGTH OF THE LOW LEVEL JET IS TREMENDOUS AND WILL
SUPPORT THE SEVERE STORM POTENTIAL. THE EXACT QUESTION IS HOW MUCH
INSTABILITY WILL BE PRESENT AS THE STORMS CROSS INTO EASTERN
KENTUCKY TONIGHT. NAM BUFKIT SOUNDINGS SHOW SOME POTENTIAL FOR
600-1000J/KG OF SBCAPE...WHICH IS MARGINAL...BUT COULD BE ENOUGH
TO ALLOW WINDS TO REACH THE SURFACE...ESPECIALLY IF WE END UP
DEALING WITH MORE LINE SEGMENTS. THUS...THE STORM PREDICTION
CENTER HAS EXPANDED THE ENHANCED RISK OF SEVERE STORMS INTO
CENTRAL KENTUCKY. IF WE DO END UP WITH A QLCS/LINE OF STORMS...
A SPIN UP TORNADO WOULD ALSO BE POSSIBLE ALONG THE LINE WITH SUCH
STRONG SHEAR NEARLY NORMAL TO THE ADVANCING STORMS. WILL CONTINUE
TO HIGHLIGHT DAMAGING WINDS/TORNADO THREAT IN THE HWO AND PLAN TO
DO A MORNING WEB BRIEFING TO HIGHLIGHT THE THREAT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 AM EST WED DEC 23 2015
THE MODELS REMAIN IN GOOD GENERAL AGREEMENT WITH THE AMPLIFIED AND
ACTIVE LONG WAVE PATTERN THROUGH EARLY NEXT WEEK...AS THE SUMMER-
LIKE BERMUDA HIGH VERY GRADUALLY SHIFTS TOWARDS THE BAHAMAS BY
EARLY NEXT WEEK. MEANWHILE...DEEP AND BROAD TROUGHING IN THE
WESTERN HALF OF THE NATION TRANSITIONS TO SPLIT FLOW BY THE
HOLIDAY WEEKEND. A CUTOFF LOW WILL DROP SOUTHEAST INTO
TEXAS/MEXICO...AND THEN SWING NORTHEAST INTO THE PLAINS AND
EVENTUALLY GREAT LAKES/OHIO VALLEY REGIONS BY EARLY NEXT WEEK.
NEAR RECORD TO RECORD TEMPERATURES AT TIMES...ALONG WITH SEVERAL
ROUNDS OF WET WEATHER STILL LOOK IN THE OFFING FOR THE OHIO AND
TENNESSEE VALLEYS THROUGH THE PERIOD.
A FRONTAL BOUNDARY WILL BE STALLING ACROSS OUR AREA THURSDAY
NIGHT...WITH A SURGE OF LOW LEVEL MOISTURE COMING IN BY FRIDAY
MORNING. CONFIDENCE REGARDING HOW MUCH RAINFALL WE WILL SEE
FRIDAY INTO FRIDAY NIGHT AS THE FRONTAL BOUNDARY GRADUALLY LIFTS
NORTH AS A WARM FRONT CONTINUES TO BE ON THE LOW SIDE. PWATS ARE
VERY HIGH...HOWEVER MID AND UPPER LEVEL SUPPORT IS NOT THAT
IMPRESSIVE...SO AM NOT CONVINCED THAT THE MAJORITY OF THE MOISTURE
WILL BE TAPPED DESPITE THE AMPLE LOW LEVEL JET IN PLACE. AS
SUCH...HAVE CONTINUED TO KEEP THINGS GENERALIZED CONCERNING THE
FLOOD POTENTIAL UNTIL THERE IS BETTER MODEL AGREEMENT.
THE BAROCLINIC ZONE WILL SHIFT NORTH OF OUR AREA BY LATE SATURDAY
INTO SATURDAY NIGHT...LEADING TO LESSER CHANCES OF POPS ACROSS OUR
AREA. THE MODELS HAVE BEEN WAFFLING SUNDAY INTO MONDAY...WITH THE
ECMWF SUGGESTING A NORTHERN STREAM TROUGH HAVING ENOUGH PUSH TO
SEND THE BOUNDARY BACK ACROSS OUR AREA ON SUNDAY...AND THEN
HOLDING BACK THE NEXT FRONT UNTIL MAINLY TUESDAY. THE GFS HAS A
LITTLE BETTER CONTINUITY...KEEPING THE BOUNDARY JUST TO OUR
NORTH...UNTIL THE NEXT SURGE OF MOISTURE ARRIVES MONDAY NIGHT.
GIVEN THE UNCERTAINTY...STUCK FAIRLY CLOSE TO THE BLENDED
GUIDANCE...ALTHOUGH DID LINGER POPS A BIT LONGER INTO TUESDAY TO
ALLOW FOR A POTENTIAL SLOWER EXIT.
THE BEST CHANCE TO TEST RECORD HIGHS STILL LOOK TO BE SATURDAY AND
SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 134 PM EST WED DEC 23 2015
VFR PREVAILED AT THE START OF THE PERIOD AND WILL PROBABLY LAST
INTO EARLY THIS EVENING. SOUTH WINDS MAY BE GUSTY AT TIMES THIS
AFTERNOON AND EVENING...WITH GUSTS OF 15 TO 25 MPH. THE STRONGEST
GUSTS ARE EXPECTED WEST OF THE FOOTHILLS. A FEW SHOWERS AND
THUNDERSTORMS COULD SHOW UP LATE IN THE DAY...BUT THEY ARE MORE
LIKELY TO HOLD OFF UNTIL TONIGHT. THE MOST LIKELY ARRIVAL TIME IN
WESTERN AREAS SUCH AS KSME AND KIOB IS BETWEEN ABOUT 03Z-
05Z...WITH PRECIPITATION THEN PROGRESSING EASTWARD ACROSS THE
REMAINDER OF THE STATE BY ABOUT 08Z. MVFR SHOULD ARRIVE SHORTLY
AFTER PRECIPITATION MOVES IN TONIGHT. ALSO...THUNDERSTORMS AND
THE HEAVIEST SHOWERS MAY CONTAIN WIND GUSTS IN EXCESS OF 40 MPH.
PRECIPITATION MAY LAST PAST DAYBREAK ON THURSDAY...ESPECIALLY IN
SOUTHEAST KY. MANY LOCATIONS MAY DETERIORATE TO IFR ON THURSDAY
MORNING...ESPECIALLY IN SOUTHEAST KY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL
SHORT TERM...KAS
LONG TERM...GEOGERIAN
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
134 PM EST WED DEC 23 2015
.UPDATE...
ISSUED AT 1019 AM EST WED DEC 23 2015
SHOWERS ARE DIMINISHING LATE THIS MORNING AS THE AREA OF PRECIP
EXITS TO THE EAST. THERE IS A SIZABLE HOLE IN THE ACTIVITY
UPSTREAM TO OUR WEST AND SOUTHWEST. MODEL FORECAST SOUNDINGS
SUGGEST THIS WILL PERSIST OVER THE JKL FORECAST AREA AS IT
PROPAGATES THROUGH...WITH MID/UPPER LEVEL DRYING TAKING PLACE AS A
LOW LEVEL CAP PERSISTS. DEEP CONVECTION COULD BEGIN TO SHOW UP
FROM THE WEST BY THE END OF THE DAY.
UPDATE ISSUED AT 654 AM EST WED DEC 23 2015
SHOWERS NOW EXPANDING ACROSS THE AREA AS THE WARM FRONT LIFTS
NORTH. LOOKS LIKE MOST OF THE RAIN WILL OCCUR IN THE NEXT FEW
HOURS...BUT A FEW SHOWERS WILL REMAIN POSSIBLE INTO THE EARLY
AFTERNOON HOURS AS A MOIST ENVIRONMENT REMAINS OVER THE AREA.
LOOKS LIKE THE SEVERE STORMS SHOULD BE KNOCKING ON OUR DOOR
SHORTLY AFTER 9 PM THIS EVENING. OUR FORECAST GRAPHICAL TIMING
LOOKS EXCELLENT RIGHT NOW.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 343 AM EST WED DEC 23 2015
...SEVERE STORMS WITH DAMAGING WINDS POSSIBLE TONIGHT...
A RATHER ACTIVE...SPRING-LIKE PATTERN EXPECTED OVER THE NEXT 36
HOURS. PRESENTLY...A WARM FRONT IS LIFTING NORTH ACROSS TENNESSEE.
SOUTHEAST WINDS TO THE NORTH OF THE FRONT HAS KEPT MUCH OF EASTERN
KENTUCKY DRY OVERNIGHT. HOWEVER...THIS IS ABOUT TO CHANGE AS THE
FRONT CONTINUES TO PUSH NORTH THIS MORNING AND WINDS TURN MORE
SOUTHERLY. THE INITIAL SURGE OF MID LEVEL ISENTROPIC ASCENT HAS
GENERATED A LARGER POCKET OF RAINFALL OVER THE CUMBERLAND
PLATEAU...AND THIS RAIN WILL MOVE NORTH ACROSS OUR WESTERN
COUNTIES THROUGH 7 AM. INCREASED POPS TO CATEGORICAL WITH THIS
RAIN SPREADING NORTH. TO THE EAST...WE SHOULD REMAIN WITH VERY
LITTLE AS THE DOWNSLOPING CONTINUES TO EAT AWAY AT SHOWERS TRYING
TO PUSH NORTH. EVENTUALLY THE DRY AIR WILL BE OVERCOME...LIKELY
AROUND OR SHORTLY AFTER 7 AM...WITH SCATTERED SHOWERS PUSHING
NORTH ACROSS THE REGION THROUGH THE MORNING. HRRR HAS BEEN
CONSISTENT ON LINGERING SHOWERS INTO THE AFTERNOON...SO HAVE
KEPT POPS IN THE FORECAST THROUGH EARLY AFTERNOON. IT DOES APPEAR
WE SHOULD SEE A BETTER BREAK IN PRECIPITATION BY LATE AFTERNOON
THROUGH THE EARLY EVENING HOURS..AS SUBSIDENCE SPREADS IN AHEAD OF
THE APPROACHING COLD FRONT.
WITH THE FRONT APPROACHING THIS AFTERNOON...THE GRADIENT SHOULD
INCREASE AND WE WILL SEE GUSTY WINDS DEVELOP AREA WIDE. THE NAM
BUFKIT MOMENTUM TRANSFER EQUATION SUPPORTS 3O TO 35 MPH WIND
GUSTS...ESPECIALLY OUT ACROSS CENTRAL KENTUCKY...EXTENDING ACROSS
THE BLUEGRASS. WIND GUSTS UP TO 25 WILL REMAIN POSSIBLE TO THE
EAST. PUT IN A MENTION IN THE HWO OF THE GUSTY WINDS THIS
AFTERNOON.
FINALLY...MOVING ONTO THE SEVERE POTENTIAL TONIGHT. MODELS ARE
STILL NOT IN GREAT AGREEMENT ON OVERALL TIMING...AS A FEW OF THE
HI-RES MODELS SUPPORT AN EARLIER ROUND OF CONVECTION IN THE
EVENING...WHILE OTHERS HOLD OFF UNTIL OVERNIGHT. THUS...CONFIDENCE
IS HIGH ON THE THREAT FOR SEVERE STORMS OCCURRING TONIGHT...THERE
REMAINS CONSIDERABLE SPREAD ON WHETHER IT OCCURS MID TO LATE
EVENING OR AFTER MIDNIGHT. REGARDLESS OF TIMING...SHEAR GENERATED
WITH THE STRENGTH OF THE LOW LEVEL JET IS TREMENDOUS AND WILL
SUPPORT THE SEVERE STORM POTENTIAL. THE EXACT QUESTION IS HOW MUCH
INSTABILITY WILL BE PRESENT AS THE STORMS CROSS INTO EASTERN
KENTUCKY TONIGHT. NAM BUFKIT SOUNDINGS SHOW SOME POTENTIAL FOR
600-1000J/KG OF SBCAPE...WHICH IS MARGINAL...BUT COULD BE ENOUGH
TO ALLOW WINDS TO REACH THE SURFACE...ESPECIALLY IF WE END UP
DEALING WITH MORE LINE SEGMENTS. THUS...THE STORM PREDICTION
CENTER HAS EXPANDED THE ENHANCED RISK OF SEVERE STORMS INTO
CENTRAL KENTUCKY. IF WE DO END UP WITH A QLCS/LINE OF STORMS...
A SPIN UP TORNADO WOULD ALSO BE POSSIBLE ALONG THE LINE WITH SUCH
STRONG SHEAR NEARLY NORMAL TO THE ADVANCING STORMS. WILL CONTINUE
TO HIGHLIGHT DAMAGING WINDS/TORNADO THREAT IN THE HWO AND PLAN TO
DO A MORNING WEB BRIEFING TO HIGHLIGHT THE THREAT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 AM EST WED DEC 23 2015
THE MODELS REMAIN IN GOOD GENERAL AGREEMENT WITH THE AMPLIFIED AND
ACTIVE LONG WAVE PATTERN THROUGH EARLY NEXT WEEK...AS THE SUMMER-
LIKE BERMUDA HIGH VERY GRADUALLY SHIFTS TOWARDS THE BAHAMAS BY
EARLY NEXT WEEK. MEANWHILE...DEEP AND BROAD TROUGHING IN THE
WESTERN HALF OF THE NATION TRANSITIONS TO SPLIT FLOW BY THE
HOLIDAY WEEKEND. A CUTOFF LOW WILL DROP SOUTHEAST INTO
TEXAS/MEXICO...AND THEN SWING NORTHEAST INTO THE PLAINS AND
EVENTUALLY GREAT LAKES/OHIO VALLEY REGIONS BY EARLY NEXT WEEK.
NEAR RECORD TO RECORD TEMPERATURES AT TIMES...ALONG WITH SEVERAL
ROUNDS OF WET WEATHER STILL LOOK IN THE OFFING FOR THE OHIO AND
TENNESSEE VALLEYS THROUGH THE PERIOD.
A FRONTAL BOUNDARY WILL BE STALLING ACROSS OUR AREA THURSDAY
NIGHT...WITH A SURGE OF LOW LEVEL MOISTURE COMING IN BY FRIDAY
MORNING. CONFIDENCE REGARDING HOW MUCH RAINFALL WE WILL SEE
FRIDAY INTO FRIDAY NIGHT AS THE FRONTAL BOUNDARY GRADUALLY LIFTS
NORTH AS A WARM FRONT CONTINUES TO BE ON THE LOW SIDE. PWATS ARE
VERY HIGH...HOWEVER MID AND UPPER LEVEL SUPPORT IS NOT THAT
IMPRESSIVE...SO AM NOT CONVINCED THAT THE MAJORITY OF THE MOISTURE
WILL BE TAPPED DESPITE THE AMPLE LOW LEVEL JET IN PLACE. AS
SUCH...HAVE CONTINUED TO KEEP THINGS GENERALIZED CONCERNING THE
FLOOD POTENTIAL UNTIL THERE IS BETTER MODEL AGREEMENT.
THE BAROCLINIC ZONE WILL SHIFT NORTH OF OUR AREA BY LATE SATURDAY
INTO SATURDAY NIGHT...LEADING TO LESSER CHANCES OF POPS ACROSS OUR
AREA. THE MODELS HAVE BEEN WAFFLING SUNDAY INTO MONDAY...WITH THE
ECMWF SUGGESTING A NORTHERN STREAM TROUGH HAVING ENOUGH PUSH TO
SEND THE BOUNDARY BACK ACROSS OUR AREA ON SUNDAY...AND THEN
HOLDING BACK THE NEXT FRONT UNTIL MAINLY TUESDAY. THE GFS HAS A
LITTLE BETTER CONTINUITY...KEEPING THE BOUNDARY JUST TO OUR
NORTH...UNTIL THE NEXT SURGE OF MOISTURE ARRIVES MONDAY NIGHT.
GIVEN THE UNCERTAINTY...STUCK FAIRLY CLOSE TO THE BLENDED
GUIDANCE...ALTHOUGH DID LINGER POPS A BIT LONGER INTO TUESDAY TO
ALLOW FOR A POTENTIAL SLOWER EXIT.
THE BEST CHANCE TO TEST RECORD HIGHS STILL LOOK TO BE SATURDAY AND
SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 134 PM EST WED DEC 23 2015
VFR PREVAILED AT THE START OF THE PERIOD AND WILL PROBABLY LAST
INTO EARLY THIS EVENING. SOUTH WINDS MAY BE GUSTY AT TIMES THIS
AFTERNOON AND EVENING...WITH GUSTS OF 15 TO 25 MPH. THE STRONGEST
GUSTS ARE EXPECTED WEST OF THE FOOTHILLS. A FEW SHOWERS AND
THUNDERSTORMS COULD SHOW UP LATE IN THE DAY...BUT THEY ARE MORE
LIKELY TO HOLD OFF UNTIL TONIGHT. THE MOST LIKELY ARRIVAL TIME IN
WESTERN AREAS SUCH AS KSME AND KIOB IS BETWEEN ABOUT 03Z-
05Z...WITH PRECIPITATION THEN PROGRESSING EASTWARD ACROSS THE
REMAINDER OF THE STATE BY ABOUT 08Z. MVFR SHOULD ARRIVE SHORTLY
AFTER PRECIPITATION MOVES IN TONIGHT. ALSO...THUNDERSTORMS AND
THE HEAVIEST SHOWERS MAY CONTAIN WIND GUSTS IN EXCESS OF 40 MPH.
PRECIPITATION MAY LAST PAST DAYBREAK ON THURSDAY...ESPECIALLY IN
SOUTHEAST KY. MANY LOCATIONS MAY DETERIORATE TO IFR ON THURSDAY
MORNING...ESPECIALLY IN SOUTHEAST KY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL/KAS
SHORT TERM...KAS
LONG TERM...GEOGERIAN
AVIATION...HAL
AREA FORECAST DISCUSSION
NWS JACKSON KY
1019 AM EST WED DEC 23 2015
.UPDATE...
ISSUED AT 1019 AM EST WED DEC 23 2015
SHOWERS ARE DIMINISHING LATE THIS MORNING AS THE AREA OF PRECIP
EXITS TO THE EAST. THERE IS A SIZABLE HOLE IN THE ACTIVITY
UPSTREAM TO OUR WEST AND SOUTHWEST. MODEL FORECAST SOUNDINGS
SUGGEST THIS WILL PERSIST OVER THE JKL FORECAST AREA AS IT
PROPAGATES THROUGH...WITH MID/UPPER LEVEL DRYING TAKING PLACE AS A
LOW LEVEL CAP PERSISTS. DEEP CONVECTION COULD BEGIN TO SHOW UP
FROM THE WEST BY THE END OF THE DAY.
UPDATE ISSUED AT 654 AM EST WED DEC 23 2015
SHOWERS NOW EXPANDING ACROSS THE AREA AS THE WARM FRONT LIFTS
NORTH. LOOKS LIKE MOST OF THE RAIN WILL OCCUR IN THE NEXT FEW
HOURS...BUT A FEW SHOWERS WILL REMAIN POSSIBLE INTO THE EARLY
AFTERNOON HOURS AS A MOIST ENVIRONMENT REMAINS OVER THE AREA.
LOOKS LIKE THE SEVERE STORMS SHOULD BE KNOCKING ON OUR DOOR
SHORTLY AFTER 9 PM THIS EVENING. OUR FORECAST GRAPHICAL TIMING
LOOKS EXCELLENT RIGHT NOW.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 343 AM EST WED DEC 23 2015
...SEVERE STORMS WITH DAMAGING WINDS POSSIBLE TONIGHT...
A RATHER ACTIVE...SPRING-LIKE PATTERN EXPECTED OVER THE NEXT 36
HOURS. PRESENTLY...A WARM FRONT IS LIFTING NORTH ACROSS TENNESSEE.
SOUTHEAST WINDS TO THE NORTH OF THE FRONT HAS KEPT MUCH OF EASTERN
KENTUCKY DRY OVERNIGHT. HOWEVER...THIS IS ABOUT TO CHANGE AS THE
FRONT CONTINUES TO PUSH NORTH THIS MORNING AND WINDS TURN MORE
SOUTHERLY. THE INITIAL SURGE OF MID LEVEL ISENTROPIC ASCENT HAS
GENERATED A LARGER POCKET OF RAINFALL OVER THE CUMBERLAND
PLATEAU...AND THIS RAIN WILL MOVE NORTH ACROSS OUR WESTERN
COUNTIES THROUGH 7 AM. INCREASED POPS TO CATEGORICAL WITH THIS
RAIN SPREADING NORTH. TO THE EAST...WE SHOULD REMAIN WITH VERY
LITTLE AS THE DOWNSLOPING CONTINUES TO EAT AWAY AT SHOWERS TRYING
TO PUSH NORTH. EVENTUALLY THE DRY AIR WILL BE OVERCOME...LIKELY
AROUND OR SHORTLY AFTER 7 AM...WITH SCATTERED SHOWERS PUSHING
NORTH ACROSS THE REGION THROUGH THE MORNING. HRRR HAS BEEN
CONSISTENT ON LINGERING SHOWERS INTO THE AFTERNOON...SO HAVE
KEPT POPS IN THE FORECAST THROUGH EARLY AFTERNOON. IT DOES APPEAR
WE SHOULD SEE A BETTER BREAK IN PRECIPITATION BY LATE AFTERNOON
THROUGH THE EARLY EVENING HOURS..AS SUBSIDENCE SPREADS IN AHEAD OF
THE APPROACHING COLD FRONT.
WITH THE FRONT APPROACHING THIS AFTERNOON...THE GRADIENT SHOULD
INCREASE AND WE WILL SEE GUSTY WINDS DEVELOP AREA WIDE. THE NAM
BUFKIT MOMENTUM TRANSFER EQUATION SUPPORTS 3O TO 35 MPH WIND
GUSTS...ESPECIALLY OUT ACROSS CENTRAL KENTUCKY...EXTENDING ACROSS
THE BLUEGRASS. WIND GUSTS UP TO 25 WILL REMAIN POSSIBLE TO THE
EAST. PUT IN A MENTION IN THE HWO OF THE GUSTY WINDS THIS
AFTERNOON.
FINALLY...MOVING ONTO THE SEVERE POTENTIAL TONIGHT. MODELS ARE
STILL NOT IN GREAT AGREEMENT ON OVERALL TIMING...AS A FEW OF THE
HI-RES MODELS SUPPORT AN EARLIER ROUND OF CONVECTION IN THE
EVENING...WHILE OTHERS HOLD OFF UNTIL OVERNIGHT. THUS...CONFIDENCE
IS HIGH ON THE THREAT FOR SEVERE STORMS OCCURRING TONIGHT...THERE
REMAINS CONSIDERABLE SPREAD ON WHETHER IT OCCURS MID TO LATE
EVENING OR AFTER MIDNIGHT. REGARDLESS OF TIMING...SHEAR GENERATED
WITH THE STRENGTH OF THE LOW LEVEL JET IS TREMENDOUS AND WILL
SUPPORT THE SEVERE STORM POTENTIAL. THE EXACT QUESTION IS HOW MUCH
INSTABILITY WILL BE PRESENT AS THE STORMS CROSS INTO EASTERN
KENTUCKY TONIGHT. NAM BUFKIT SOUNDINGS SHOW SOME POTENTIAL FOR
600-1000J/KG OF SBCAPE...WHICH IS MARGINAL...BUT COULD BE ENOUGH
TO ALLOW WINDS TO REACH THE SURFACE...ESPECIALLY IF WE END UP
DEALING WITH MORE LINE SEGMENTS. THUS...THE STORM PREDICTION
CENTER HAS EXPANDED THE ENHANCED RISK OF SEVERE STORMS INTO
CENTRAL KENTUCKY. IF WE DO END UP WITH A QLCS/LINE OF STORMS...
A SPIN UP TORNADO WOULD ALSO BE POSSIBLE ALONG THE LINE WITH SUCH
STRONG SHEAR NEARLY NORMAL TO THE ADVANCING STORMS. WILL CONTINUE
TO HIGHLIGHT DAMAGING WINDS/TORNADO THREAT IN THE HWO AND PLAN TO
DO A MORNING WEB BRIEFING TO HIGHLIGHT THE THREAT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 AM EST WED DEC 23 2015
THE MODELS REMAIN IN GOOD GENERAL AGREEMENT WITH THE AMPLIFIED AND
ACTIVE LONG WAVE PATTERN THROUGH EARLY NEXT WEEK...AS THE SUMMER-
LIKE BERMUDA HIGH VERY GRADUALLY SHIFTS TOWARDS THE BAHAMAS BY
EARLY NEXT WEEK. MEANWHILE...DEEP AND BROAD TROUGHING IN THE
WESTERN HALF OF THE NATION TRANSITIONS TO SPLIT FLOW BY THE
HOLIDAY WEEKEND. A CUTOFF LOW WILL DROP SOUTHEAST INTO
TEXAS/MEXICO...AND THEN SWING NORTHEAST INTO THE PLAINS AND
EVENTUALLY GREAT LAKES/OHIO VALLEY REGIONS BY EARLY NEXT WEEK.
NEAR RECORD TO RECORD TEMPERATURES AT TIMES...ALONG WITH SEVERAL
ROUNDS OF WET WEATHER STILL LOOK IN THE OFFING FOR THE OHIO AND
TENNESSEE VALLEYS THROUGH THE PERIOD.
A FRONTAL BOUNDARY WILL BE STALLING ACROSS OUR AREA THURSDAY
NIGHT...WITH A SURGE OF LOW LEVEL MOISTURE COMING IN BY FRIDAY
MORNING. CONFIDENCE REGARDING HOW MUCH RAINFALL WE WILL SEE
FRIDAY INTO FRIDAY NIGHT AS THE FRONTAL BOUNDARY GRADUALLY LIFTS
NORTH AS A WARM FRONT CONTINUES TO BE ON THE LOW SIDE. PWATS ARE
VERY HIGH...HOWEVER MID AND UPPER LEVEL SUPPORT IS NOT THAT
IMPRESSIVE...SO AM NOT CONVINCED THAT THE MAJORITY OF THE MOISTURE
WILL BE TAPPED DESPITE THE AMPLE LOW LEVEL JET IN PLACE. AS
SUCH...HAVE CONTINUED TO KEEP THINGS GENERALIZED CONCERNING THE
FLOOD POTENTIAL UNTIL THERE IS BETTER MODEL AGREEMENT.
THE BAROCLINIC ZONE WILL SHIFT NORTH OF OUR AREA BY LATE SATURDAY
INTO SATURDAY NIGHT...LEADING TO LESSER CHANCES OF POPS ACROSS OUR
AREA. THE MODELS HAVE BEEN WAFFLING SUNDAY INTO MONDAY...WITH THE
ECMWF SUGGESTING A NORTHERN STREAM TROUGH HAVING ENOUGH PUSH TO
SEND THE BOUNDARY BACK ACROSS OUR AREA ON SUNDAY...AND THEN
HOLDING BACK THE NEXT FRONT UNTIL MAINLY TUESDAY. THE GFS HAS A
LITTLE BETTER CONTINUITY...KEEPING THE BOUNDARY JUST TO OUR
NORTH...UNTIL THE NEXT SURGE OF MOISTURE ARRIVES MONDAY NIGHT.
GIVEN THE UNCERTAINTY...STUCK FAIRLY CLOSE TO THE BLENDED
GUIDANCE...ALTHOUGH DID LINGER POPS A BIT LONGER INTO TUESDAY TO
ALLOW FOR A POTENTIAL SLOWER EXIT.
THE BEST CHANCE TO TEST RECORD HIGHS STILL LOOK TO BE SATURDAY AND
SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 654 AM EST WED DEC 23 2015
WHILE A FEW PERIODS OF MVFR CIGS WILL BE POSSIBLE THIS
MORNING...MAINLY VFR CONDITIONS SHOULD DOMINATE THE WEATHER ACROSS
EASTERN KENTUCKY TODAY. A FEW ISOLATED/SCATTERED SHOWERS WILL
REMAIN POSSIBLE THROUGH AT LEAST EARLY AFTERNOON. A LINE OF
SHOWERS AND STORMS WILL MOVE THROUGH TONIGHT...MAINLY AFTER 9
PM...PRODUCING A PERIOD OF THUNDERSTORMS AT THE TAF SITES. IN
ADDITION SOME GUSTY WINDS ARE EXPECTED THIS AFTERNOON AND EVENING
HEAD OF THIS LINE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...HAL/KAS
SHORT TERM...KAS
LONG TERM...GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
654 AM EST WED DEC 23 2015
.UPDATE...
ISSUED AT 654 AM EST WED DEC 23 2015
SHOWERS NOW EXPANDING ACROSS THE AREA AS THE WARM FRONT LIFTS
NORTH. LOOKS LIKE MOST OF THE RAIN WILL OCCUR IN THE NEXT FEW
HOURS...BUT A FEW SHOWERS WILL REMAIN POSSIBLE INTO THE EARLY
AFTERNOON HOURS AS A MOIST ENVIRONMENT REMAINS OVER THE AREA.
LOOKS LIKE THE SEVERE STORMS SHOULD BE KNOCKING ON OUR DOOR
SHORTLY AFTER 9 PM THIS EVENING. OUR FORECAST GRAPHICAL TIMING
LOOKS EXCELLENT RIGHT NOW.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 343 AM EST WED DEC 23 2015
...SEVERE STORMS WITH DAMAGING WINDS POSSIBLE TONIGHT...
A RATHER ACTIVE...SPRING-LIKE PATTERN EXPECTED OVER THE NEXT 36
HOURS. PRESENTLY...A WARM FRONT IS LIFTING NORTH ACROSS TENNESSEE.
SOUTHEAST WINDS TO THE NORTH OF THE FRONT HAS KEPT MUCH OF EASTERN
KENTUCKY DRY OVERNIGHT. HOWEVER...THIS IS ABOUT TO CHANGE AS THE
FRONT CONTINUES TO PUSH NORTH THIS MORNING AND WINDS TURN MORE
SOUTHERLY. THE INITIAL SURGE OF MID LEVEL ISENTROPIC ASCENT HAS
GENERATED A LARGER POCKET OF RAINFALL OVER THE CUMBERLAND
PLATEAU...AND THIS RAIN WILL MOVE NORTH ACROSS OUR WESTERN
COUNTIES THROUGH 7 AM. INCREASED POPS TO CATEGORICAL WITH THIS
RAIN SPREADING NORTH. TO THE EAST...WE SHOULD REMAIN WITH VERY
LITTLE AS THE DOWNSLOPING CONTINUES TO EAT AWAY AT SHOWERS TRYING
TO PUSH NORTH. EVENTUALLY THE DRY AIR WILL BE OVERCOME...LIKELY
AROUND OR SHORTLY AFTER 7 AM...WITH SCATTERED SHOWERS PUSHING
NORTH ACROSS THE REGION THROUGH THE MORNING. HRRR HAS BEEN
CONSISTENT ON LINGERING SHOWERS INTO THE AFTERNOON...SO HAVE
KEPT POPS IN THE FORECAST THROUGH EARLY AFTERNOON. IT DOES APPEAR
WE SHOULD SEE A BETTER BREAK IN PRECIPITATION BY LATE AFTERNOON
THROUGH THE EARLY EVENING HOURS..AS SUBSIDENCE SPREADS IN AHEAD OF
THE APPROACHING COLD FRONT.
WITH THE FRONT APPROACHING THIS AFTERNOON...THE GRADIENT SHOULD
INCREASE AND WE WILL SEE GUSTY WINDS DEVELOP AREAWIDE. THE NAM
BUFKIT MOMENTUM TRANSFER EQUATION SUPPORTS 3O TO 35 MPH WIND
GUSTS...ESPECIALLY OUT ACROSS CENTRAL KENTUCKY...EXTENDING ACROSS
THE BLUEGRASS. WIND GUSTS UP TO 25 WILL REMAIN POSSIBLE TO THE
EAST. PUT IN A MENTION IN THE HWO OF THE GUSTY WINDS THIS
AFTERNOON.
FINALLY...MOVING ONTO THE SEVERE POTENTIAL TONIGHT. MODELS ARE
STILL NOT IN GREAT AGREEMENT ON OVERALL TIMING...AS A FEW OF THE
HI-RES MODELS SUPPORT AN EARLIER ROUND OF CONVECTION IN THE
EVENING...WHILE OTHERS HOLD OFF UNTIL OVERNIGHT. THUS...CONFIDENCE
IS HIGH ON THE THREAT FOR SEVERE STORMS OCCURRING TONIGHT...THERE
REMAINS CONSIDERABLE SPREAD ON WHETHER IT OCCURS MID TO LATE
EVENING OR AFTER MIDNIGHT. REGARDLESS OF TIMING...SHEAR GENERATED
WITH THE STRENGTH OF THE LOW LEVEL JET IS TREMENDOUS AND WILL
SUPPORT THE SEVERE STORM POTENTIAL. THE EXACT QUESTION IS HOW MUCH
INSTABILITY WILL BE PRESENT AS THE STORMS CROSS INTO EASTERN
KENTUCKY TONIGHT. NAM BUFKIT SOUNDINGS SHOW SOME POTENTIAL FOR
600-1000J/KG OF SBCAPE...WHICH IS MARGINAL...BUT COULD BE ENOUGH
TO ALLOW WINDS TO REACH THE SURFACE...ESPECIALLY IF WE END UP
DEALING WITH MORE LINE SEGMENTS. THUS...THE STORM PREDICTION
CENTER HAS EXPANDED THE ENHANCED RISK OF SEVERE STORMS INTO
CENTRAL KENTUCKY. IF WE DO END UP WITH A LINE OF STORMS
(QLCS)...A SPIN UP TORNADO WOULD ALSO BE POSSIBLE ALONG THE LINE
WITH SUCH STRONG SHEAR NEARLY NORMAL TO THE ADVANCING STORMS. WILL
CONTINUE TO HIGHLIGHT DAMAGING WINDS/TORNADO THREAT IN THE HWO AND
PLAN TO DO A MORNING WEB BRIEFING TO HIGHLIGHT THE THREAT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 AM EST WED DEC 23 2015
THE MODELS REMAIN IN GOOD GENERAL AGREEMENT WITH THE AMPLIFIED AND
ACTIVE LONG WAVE PATTERN THROUGH EARLY NEXT WEEK...AS THE SUMMER-
LIKE BERMUDA HIGH VERY GRADUALLY SHIFTS TOWARDS THE BAHAMAS BY
EARLY NEXT WEEK. MEANWHILE...DEEP AND BROAD TROUGHING IN THE
WESTERN HALF OF THE NATION TRANSITIONS TO SPLIT FLOW BY THE
HOLIDAY WEEKEND. A CUTOFF LOW WILL DROP SOUTHEAST INTO
TEXAS/MEXICO...AND THEN SWING NORTHEAST INTO THE PLAINS AND
EVENTUALLY GREAT LAKES/OHIO VALLEY REGIONS BY EARLY NEXT WEEK.
NEAR RECORD TO RECORD TEMPERATURES AT TIMES...ALONG WITH SEVERAL
ROUNDS OF WET WEATHER STILL LOOK IN THE OFFING FOR THE OHIO AND
TENNESSEE VALLEYS THROUGH THE PERIOD.
A FRONTAL BOUNDARY WILL BE STALLING ACROSS OUR AREA THURSDAY
NIGHT...WITH A SURGE OF LOW LEVEL MOISTURE COMING IN BY FRIDAY
MORNING. CONFIDENCE REGARDING HOW MUCH RAINFALL WE WILL SEE
FRIDAY INTO FRIDAY NIGHT AS THE FRONTAL BOUNDARY GRADUALLY LIFTS
NORTH AS A WARM FRONT CONTINUES TO BE ON THE LOW SIDE. PWATS ARE
VERY HIGH...HOWEVER MID AND UPPER LEVEL SUPPORT IS NOT THAT
IMPRESSIVE...SO AM NOT CONVINCED THAT THE MAJORITY OF THE MOISTURE
WILL BE TAPPED DESPITE THE AMPLE LOW LEVEL JET IN PLACE. AS
SUCH...HAVE CONTINUED TO KEEP THINGS GENERALIZED CONCERNING THE
FLOOD POTENTIAL UNTIL THERE IS BETTER MODEL AGREEMENT.
THE BAROCLINIC ZONE WILL SHIFT NORTH OF OUR AREA BY LATE SATURDAY
INTO SATURDAY NIGHT...LEADING TO LESSER CHANCES OF POPS ACROSS OUR
AREA. THE MODELS HAVE BEEN WAFFLING SUNDAY INTO MONDAY...WITH THE
ECMWF SUGGESTING A NORTHERN STREAM TROUGH HAVING ENOUGH PUSH TO
SEND THE BOUNDARY BACK ACROSS OUR AREA ON SUNDAY...AND THEN
HOLDING BACK THE NEXT FRONT UNTIL MAINLY TUESDAY. THE GFS HAS A
LITTLE BETTER CONTINUITY...KEEPING THE BOUNDARY JUST TO OUR
NORTH...UNTIL THE NEXT SURGE OF MOISTURE ARRIVES MONDAY NIGHT.
GIVEN THE UNCERTAINTY...STUCK FAIRLY CLOSE TO THE BLENDED
GUIDANCE...ALTHOUGH DID LINGER POPS A BIT LONGER INTO TUESDAY TO
ALLOW FOR A POTENTIAL SLOWER EXIT.
THE BEST CHANCE TO TEST RECORD HIGHS STILL LOOK TO BE SATURDAY AND
SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 654 AM EST WED DEC 23 2015
WHILE A FEW PERIODS OF MVFR CIGS WILL BE POSSIBLE THIS
MORNING...MAINLY VFR CONDITIONS SHOULD DOMINATE THE WEATHER ACROSS
EASTERN KENTUCKY TODAY. A FEW ISOLATED/SCATTERED SHOWERS WILL
REMAIN POSSIBLE THROUGH AT LEAST EARLY AFTERNOON. A LINE OF
SHOWERS AND STORMS WILL MOVE THROUGH TONIGHT...MAINLY AFTER 9
PM...PRODUCING A PERIOD OF THUNDERSTORMS AT THE TAF SITES. IN
ADDITION SOME GUSTY WINDS ARE EXPECTED THIS AFTERNOON AND EVENING
HEAD OF THIS LINE.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...KAS
LONG TERM...GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
359 AM EST WED DEC 23 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 343 AM EST WED DEC 23 2015
...SEVERE STORMS WITH DAMAGING WINDS POSSIBLE TONIGHT...
A RATHER ACTIVE...SPRING-LIKE PATTERN EXPECTED OVER THE NEXT 36
HOURS. PRESENTLY...A WARM FRONT IS LIFTING NORTH ACROSS TENNESSEE.
SOUTHEAST WINDS TO THE NORTH OF THE FRONT HAS KEPT MUCH OF EASTERN
KENTUCKY DRY OVERNIGHT. HOWEVER...THIS IS ABOUT TO CHANGE AS THE
FRONT CONTINUES TO PUSH NORTH THIS MORNING AND WINDS TURN MORE
SOUTHERLY. THE INITIAL SURGE OF MID LEVEL ISENTROPIC ASCENT HAS
GENERATED A LARGER POCKET OF RAINFALL OVER THE CUMBERLAND
PLATEAU...AND THIS RAIN WILL MOVE NORTH ACROSS OUR WESTERN
COUNTIES THROUGH 7 AM. INCREASED POPS TO CATEGORICAL WITH THIS
RAIN SPREADING NORTH. TO THE EAST...WE SHOULD REMAIN WITH VERY
LITTLE AS THE DOWNSLOPING CONTINUES TO EAT AWAY AT SHOWERS TRYING
TO PUSH NORTH. EVENTUALLY THE DRY AIR WILL BE OVERCOME...LIKELY
AROUND OR SHORTLY AFTER 7 AM...WITH SCATTERED SHOWERS PUSHING
NORTH ACROSS THE REGION THROUGH THE MORNING. HRRR HAS BEEN
CONSISTENT ON LINGERING SHOWERS INTO THE AFTERNOON...SO HAVE
KEPT POPS IN THE FORECAST THROUGH EARLY AFTERNOON. IT DOES APPEAR
WE SHOULD SEE A BETTER BREAK IN PRECIPITATION BY LATE AFTERNOON
THROUGH THE EARLY EVENING HOURS..AS SUBSIDENCE SPREADS IN AHEAD OF
THE APPROACHING COLD FRONT.
WITH THE FRONT APPROACHING THIS AFTERNOON...THE GRADIENT SHOULD
INCREASE AND WE WILL SEE GUSTY WINDS DEVELOP AREAWIDE. THE NAM
BUFKIT MOMENTUM TRANSFER EQUATION SUPPORTS 3O TO 35 MPH WIND
GUSTS...ESPECIALLY OUT ACROSS CENTRAL KENTUCKY...EXTENDING ACROSS
THE BLUEGRASS. WIND GUSTS UP TO 25 WILL REMAIN POSSIBLE TO THE
EAST. PUT IN A MENTION IN THE HWO OF THE GUSTY WINDS THIS
AFTERNOON.
FINALLY...MOVING ONTO THE SEVERE POTENTIAL TONIGHT. MODELS ARE
STILL NOT IN GREAT AGREEMENT ON OVERALL TIMING...AS A FEW OF THE
HI-RES MODELS SUPPORT AN EARLIER ROUND OF CONVECTION IN THE
EVENING...WHILE OTHERS HOLD OFF UNTIL OVERNIGHT. THUS...CONFIDENCE
IS HIGH ON THE THREAT FOR SEVERE STORMS OCCURRING TONIGHT...THERE
REMAINS CONSIDERABLE SPREAD ON WHETHER IT OCCURS MID TO LATE
EVENING OR AFTER MIDNIGHT. REGARDLESS OF TIMING...SHEAR GENERATED
WITH THE STRENGTH OF THE LOW LEVEL JET IS TREMENDOUS AND WILL
SUPPORT THE SEVERE STORM POTENTIAL. THE EXACT QUESTION IS HOW MUCH
INSTABILITY WILL BE PRESENT AS THE STORMS CROSS INTO EASTERN
KENTUCKY TONIGHT. NAM BUFKIT SOUNDINGS SHOW SOME POTENTIAL FOR
600-1000J/KG OF SBCAPE...WHICH IS MARGINAL...BUT COULD BE ENOUGH
TO ALLOW WINDS TO REACH THE SURFACE...ESPECIALLY IF WE END UP
DEALING WITH MORE LINE SEGMENTS. THUS...THE STORM PREDICTION
CENTER HAS EXPANDED THE ENHANCED RISK OF SEVERE STORMS INTO
CENTRAL KENTUCKY. IF WE DO END UP WITH A LINE OF STORMS
(QLCS)...A SPIN UP TORNADO WOULD ALSO BE POSSIBLE ALONG THE LINE
WITH SUCH STRONG SHEAR NEARLY NORMAL TO THE ADVANCING STORMS. WILL
CONTINUE TO HIGHLIGHT DAMAGING WINDS/TORNADO THREAT IN THE HWO AND
PLAN TO DO A MORNING WEB BRIEFING TO HIGHLIGHT THE THREAT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 359 AM EST WED DEC 23 2015
THE MODELS REMAIN IN GOOD GENERAL AGREEMENT WITH THE AMPLIFIED AND
ACTIVE LONG WAVE PATTERN THROUGH EARLY NEXT WEEK...AS THE SUMMER-
LIKE BERMUDA HIGH VERY GRADUALLY SHIFTS TOWARDS THE BAHAMAS BY
EARLY NEXT WEEK. MEANWHILE...DEEP AND BROAD TROUGHING IN THE
WESTERN HALF OF THE NATION TRANSITIONS TO SPLIT FLOW BY THE
HOLIDAY WEEKEND. A CUTOFF LOW WILL DROP SOUTHEAST INTO
TEXAS/MEXICO...AND THEN SWING NORTHEAST INTO THE PLAINS AND
EVENTUALLY GREAT LAKES/OHIO VALLEY REGIONS BY EARLY NEXT WEEK.
NEAR RECORD TO RECORD TEMPERATURES AT TIMES...ALONG WITH SEVERAL
ROUNDS OF WET WEATHER STILL LOOK IN THE OFFING FOR THE OHIO AND
TENNESSEE VALLEYS THROUGH THE PERIOD.
A FRONTAL BOUNDARY WILL BE STALLING ACROSS OUR AREA THURSDAY
NIGHT...WITH A SURGE OF LOW LEVEL MOISTURE COMING IN BY FRIDAY
MORNING. CONFIDENCE REGARDING HOW MUCH RAINFALL WE WILL SEE
FRIDAY INTO FRIDAY NIGHT AS THE FRONTAL BOUNDARY GRADUALLY LIFTS
NORTH AS A WARM FRONT CONTINUES TO BE ON THE LOW SIDE. PWATS ARE
VERY HIGH...HOWEVER MID AND UPPER LEVEL SUPPORT IS NOT THAT
IMPRESSIVE...SO AM NOT CONVINCED THAT THE MAJORITY OF THE MOISTURE
WILL BE TAPPED DESPITE THE AMPLE LOW LEVEL JET IN PLACE. AS
SUCH...HAVE CONTINUED TO KEEP THINGS GENERALIZED CONCERNING THE
FLOOD POTENTIAL UNTIL THERE IS BETTER MODEL AGREEMENT.
THE BAROCLINIC ZONE WILL SHIFT NORTH OF OUR AREA BY LATE SATURDAY
INTO SATURDAY NIGHT...LEADING TO LESSER CHANCES OF POPS ACROSS OUR
AREA. THE MODELS HAVE BEEN WAFFLING SUNDAY INTO MONDAY...WITH THE
ECMWF SUGGESTING A NORTHERN STREAM TROUGH HAVING ENOUGH PUSH TO
SEND THE BOUNDARY BACK ACROSS OUR AREA ON SUNDAY...AND THEN
HOLDING BACK THE NEXT FRONT UNTIL MAINLY TUESDAY. THE GFS HAS A
LITTLE BETTER CONTINUITY...KEEPING THE BOUNDARY JUST TO OUR
NORTH...UNTIL THE NEXT SURGE OF MOISTURE ARRIVES MONDAY NIGHT.
GIVEN THE UNCERTAINTY...STUCK FAIRLY CLOSE TO THE BLENDED
GUIDANCE...ALTHOUGH DID LINGER POPS A BIT LONGER INTO TUESDAY TO
ALLOW FOR A POTENTIAL SLOWER EXIT.
THE BEST CHANCE TO TEST RECORD HIGHS STILL LOOK TO BE SATURDAY AND
SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 122 AM EST WED DEC 23 2015
DOWNSLOPING FLOW WILL LIKELY KEEP VFR CONDITIONS AT THE TAF SITES
THROUGH MOST OF THE NIGHT. SOME MVFR COULD SNEAK IN AT
TIMES...ESPECIALLY NEAR KSME...BUT SHOULD PREDOMINANTLY BE VFR.
SOME SHOWERS MAY WORK ACROSS THE AREA AFTER DAYBREAK...WITH
PERHAPS A BRIEF PERIOD OR TWO OF MVFR CIGS. OTHERWISE...VFR
CONDITIONS WILL RETURN BY THE AFTERNOON. LOW LEVEL WINDS WILL RAMP
UP OVERNIGHT...SO INCLUDED SOME LOW LEVEL WIND SHEAR. WINDS WILL
TURN GUSTY AGAIN THIS AFTERNOON THROUGH THE EVENING AS THE
GRADIENT INCREASED AHEAD OF AN APPROACHING COLD FRONT. THIS FRONT
WILL SEND A LINE OF STRONG...POSSIBLY SOME SEVERE...STORMS ACROSS
THE AREA OVERNIGHT TONIGHT...WITH THE MAIN THREAT BEING DAMAGING
WINDS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...GEOGERIAN
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
343 AM EST WED DEC 23 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 343 AM EST WED DEC 23 2015
...SEVERE STORMS WITH DAMAGING WINDS POSSIBLE TONIGHT...
A RATHER ACTIVE...SPRING-LIKE PATTERN EXPECTED OVER THE NEXT 36
HOURS. PRESENTLY...A WARM FRONT IS LIFTING NORTH ACROSS TENNESSEE.
SOUTHEAST WINDS TO THE NORTH OF THE FRONT HAS KEPT MUCH OF EASTERN
KENTUCKY DRY OVERNIGHT. HOWEVER...THIS IS ABOUT TO CHANGE AS THE
FRONT CONTINUES TO PUSH NORTH THIS MORNING AND WINDS TURN MORE
SOUTHERLY. THE INITIAL SURGE OF MID LEVEL ISENTROPIC ASCENT HAS
GENERATED A LARGER POCKET OF RAINFALL OVER THE CUMBERLAND
PLATEAU...AND THIS RAIN WILL MOVE NORTH ACROSS OUR WESTERN
COUNTIES THROUGH 7 AM. INCREASED POPS TO CATEGORICAL WITH THIS
RAIN SPREADING NORTH. TO THE EAST...WE SHOULD REMAIN WITH VERY
LITTLE AS THE DOWNSLOPING CONTINUES TO EAT AWAY AT SHOWERS TRYING
TO PUSH NORTH. EVENTUALLY THE DRY AIR WILL BE OVERCOME...LIKELY
AROUND OR SHORTLY AFTER 7 AM...WITH SCATTERED SHOWERS PUSHING
NORTH ACROSS THE REGION THROUGH THE MORNING. HRRR HAS BEEN
CONSISTENT ON LINGERING SHOWERS INTO THE AFTERNOON...SO HAVE
KEPT POPS IN THE FORECAST THROUGH EARLY AFTERNOON. IT DOES APPEAR
WE SHOULD SEE A BETTER BREAK IN PRECIPITATION BY LATE AFTERNOON
THROUGH THE EARLY EVENING HOURS..AS SUBSIDENCE SPREADS IN AHEAD OF
THE APPROACHING COLD FRONT.
WITH THE FRONT APPROACHING THIS AFTERNOON...THE GRADIENT SHOULD
INCREASE AND WE WILL SEE GUSTY WINDS DEVELOP AREAWIDE. THE NAM
BUFKIT MOMENTUM TRANSFER EQUATION SUPPORTS 3O TO 35 MPH WIND
GUSTS...ESPECIALLY OUT ACROSS CENTRAL KENTUCKY...EXTENDING ACROSS
THE BLUEGRASS. WIND GUSTS UP TO 25 WILL REMAIN POSSIBLE TO THE
EAST. PUT IN A MENTION IN THE HWO OF THE GUSTY WINDS THIS
AFTERNOON.
FINALLY...MOVING ONTO THE SEVERE POTENTIAL TONIGHT. MODELS ARE
STILL NOT IN GREAT AGREEMENT ON OVERALL TIMING...AS A FEW OF THE
HI-RES MODELS SUPPORT AN EARLIER ROUND OF CONVECTION IN THE
EVENING...WHILE OTHERS HOLD OFF UNTIL OVERNIGHT. THUS...CONFIDENCE
IS HIGH ON THE THREAT FOR SEVERE STORMS OCCURRING TONIGHT...THERE
REMAINS CONSIDERABLE SPREAD ON WHETHER IT OCCURS MID TO LATE
EVENING OR AFTER MIDNIGHT. REGARDLESS OF TIMING...SHEAR GENERATED
WITH THE STRENGTH OF THE LOW LEVEL JET IS TREMENDOUS AND WILL
SUPPORT THE SEVERE STORM POTENTIAL. THE EXACT QUESTION IS HOW MUCH
INSTABILITY WILL BE PRESENT AS THE STORMS CROSS INTO EASTERN
KENTUCKY TONIGHT. NAM BUFKIT SOUNDINGS SHOW SOME POTENTIAL FOR
600-1000J/KG OF SBCAPE...WHICH IS MARGINAL...BUT COULD BE ENOUGH
TO ALLOW WINDS TO REACH THE SURFACE...ESPECIALLY IF WE END UP
DEALING WITH MORE LINE SEGMENTS. THUS...THE STORM PREDICTION
CENTER HAS EXPANDED THE ENHANCED RISK OF SEVERE STORMS INTO
CENTRAL KENTUCKY. IF WE DO END UP WITH A LINE OF STORMS
(QLCS)...A SPIN UP TORNADO WOULD ALSO BE POSSIBLE ALONG THE LINE
WITH SUCH STRONG SHEAR NEARLY NORMAL TO THE ADVANCING STORMS. WILL
CONTINUE TO HIGHLIGHT DAMAGING WINDS/TORNADO THREAT IN THE HWO AND
PLAN TO DO A MORNING WEB BRIEFING TO HIGHLIGHT THE THREAT.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 343 AM EST WED DEC 23 2015
LONG TERM DISCUSSION WILL FOLLOW SHORTLY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 122 AM EST WED DEC 23 2015
DOWNSLOPING FLOW WILL LIKELY KEEP VFR CONDITIONS AT THE TAF SITES
THROUGH MOST OF THE NIGHT. SOME MVFR COULD SNEAK IN AT
TIMES...ESPECIALLY NEAR KSME...BUT SHOULD PREDOMINANTLY BE VFR.
SOME SHOWERS MAY WORK ACROSS THE AREA AFTER DAYBREAK...WITH
PERHAPS A BRIEF PERIOD OR TWO OF MVFR CIGS. OTHERWISE...VFR
CONDITIONS WILL RETURN BY THE AFTERNOON. LOW LEVEL WINDS WILL RAMP
UP OVERNIGHT...SO INCLUDED SOME LOW LEVEL WIND SHEAR. WINDS WILL
TURN GUSTY AGAIN THIS AFTERNOON THROUGH THE EVENING AS THE
GRADIENT INCREASED AHEAD OF AN APPROACHING COLD FRONT. THIS FRONT
WILL SEND A LINE OF STRONG...POSSIBLY SOME SEVERE...STORMS ACROSS
THE AREA OVERNIGHT TONIGHT...WITH THE MAIN THREAT BEING DAMAGING
WINDS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KAS
LONG TERM...GEOGERIAN/KAS
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1243 PM CST WED DEC 23 2015
...18Z SOUNDING DISCUSSION...
INHIBITION IN THE LOW LEVELS HAS MOSTLY BEEN ERODED DESPITE LOW
CLOUDS/MARINE LAYER HANGING OVER MUCH OF THE AREA. VERY MOIST AND
UNSTABLE ATMOSPHERE IS IN PLACE WITH SBCAPE OF 2300 J/KG AND
PRECIPITABLE WATER VALUE OF 1.64 INCHES NOW. THERE HAVE BEEN SOME
BREAKS IN THE CLOUDS MAINLY SOUTH OF THE TIDAL LAKES THIS MORNING
THAT HAVE BOOSTED TEMPERATURES INTO THE UPPER 70S TO NEAR 80 AS OF
NOON. WHILE WE HAVE LOST SOME DIRECTIONAL SHEAR AS WINDS AT/NEAR
THE SURFACE ARE NOW SOUTHERLY INSTEAD OF SOUTHEASTERLY...SPEED
SHEAR IS IMPRESSIVE. WINDS OF 50 KNOTS WERE OBSERVED AT 2000
FEET...A STRONG LOW LEVEL WIND. 0-1KM AND 0-3KM SRH VALUES ARE
OVER 500 M2/S2...WHICH IS QUITE SUPPORTIVE OF SEVERE POTENTIAL.
SOME NEGATIVE FACTORS TO THE SET UP ARE THE LOW CLOUDS/MARINE
LAYER ALREADY MENTIONED EARLIER LIMITING SURFACE HEATING.
DOWNDRAFT CAPE HAS DECREASED FURTHER WHICH WOULD SUGGEST EVEN LESS
LIKELIHOOD OF SEVERE DOWNBURST WINDS. IF WE ARE ABLE TO MIX IN
SOME DRIER AIR...WHICH ISN`T OUT OF THE QUESTION WITH STRONG LOW
LEVEL WINDS...WE MAY BE ABLE TO MIX DOWN STRONGER GUSTS TO THE
SURFACE. FREEZING LEVEL HAS INCREASED BY ABOUT 400 FEET
SUGGESTING LESSER POTENTIAL OF SEVERE HAIL. LOCAL CHAP /CONVECTIVE
HAZARD ASSESSMENT PROGRAM/ METHOD RUNNING OFF AN UNMODIFIED
SOUNDING PROVIDES LITTLE IN THE WAY OF SEVERE WEATHER. IF WE
MODIFY FOR ANTICIPATED UPPER LEVEL DYNAMICS...RICKS INDEX DOES NOT
CHANGE MUCH AND REMAINS UNDER SEVERE LEVELS WITH SUBSEVERE WIND
GUST POTENTIAL OF 30 KNOTS. THE ONE THING CHAP DOES PING ON IS
POTENTIAL FOR HIGH RAINFALL RATES.
WE CONTINUE TO WATCH CONVECTIVE TRENDS OVER WESTERN
LOUISIANA...WHICH MAY HOLD THE BEST POTENTIAL FOR ANY SEVERE
WEATHER. THIS HINGES ON DAYTIME HEATING...WHICH HAS BEEN LIMITED
SO FAR.
18Z BALLOON INFO: THE BALLOON`S ASCENT LASTED 94 MINUTES AND
TRAVELED 88 MILES DOWNRANGE FROM THE OFFICE BURSTING OVER VERNAL
AT A HEIGHT OF 20.2 MILES ABOVE THE GROUND.
ANSORGE
&&
.PREV DISCUSSION... /ISSUED 900 AM CST WED DEC 23 2015/
UPDATE...
OVERALL CONVECTIVE COVERAGE HAS DECREASED THIS MORNING AS THE
REGION HAS STABALIZED A BIT IN THE WAKE OF THE RAINFALL THAT
OCCURRED EARLIER TODAY. GIVEN THIS TREND...HAVE LOWERED POPS FOR
THE FORECAST AREA THROUGH THE EARLY AFTERNOON HOURS INTO THE
CHANCE RANGE FROM CATEGORICAL. HOWEVER...ANOTHER ROUND OF
CONVECTIVE DEVELOPMENT STILL LOOKS LIKELY FROM MID-AFTERNOON
THROUGH THE EVENING HOURS AS THE ATMOSPHERE WARMS AND TURNS MORE
UNSTABLE. ADDITIONALLY...ANOTHER UPPER LEVEL IMPULSE OF INCREASED
VORTICITY AND OMEGA WILL SLIDE THROUGH THE LOWER MISSISSIPPI
VALLEY DURING THE AFTERNOON HOURS. THIS INCREASE IN LIFT ALOFT
SHOULD PROVIDE ENOUGH OF A CATALYST TO FIRE OFF ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. HAVE LIKELY POPS IN PLACE FOR THE LATE
AFTERNOON AND EVENING HOURS TO REFLECT THIS RISK. OUTSIDE OF THE
POP ADJUSTMENTS...NO OTHER FORECAST CHANGES WERE MADE AT THIS
TIME. 32
PREV DISCUSSION... /ISSUED 758 AM CST WED DEC 23 2015/
.SOUNDING DISCUSSION...
BOTTOM LINE UP FRONT...ALL MODES OF SEVERE WEATHER REMAIN POSSIBLE
TODAY. A VERY MOIST ATMOSPHERE WAS SAMPLED THIS MORNING WITH A
PRECIPITABLE WATER VALUE OF 1.74 INCHES. THIS IS 2 STANDARD
DEVIATIONS ABOVE NORMAL AND A RECORD VALUE FOR THIS DATE/TIME.
MOST UNSTABLE CAPE OF ABOUT 1200 J/KG EXISTS WITH INHIBITION IN
THE FORM OF A CAPPING INVERSION. ASSUMING LOW CLOUDS AND FOG
DISSIPATE AND WE HAVE SOME SURFACE HEATING...THIS CAPPING
INVERSION SHOULD ERODE. WITH QUITE A BIT OF MOISTURE IN THE LOW-
LEVELS...THE DOWNDRAFT CAPE IS NOT IN THE OPTIMUM RANGE FOR
DAMAGING STRAIGHT LINE WINDS. THIS MAY CHANGE IF DRIER AIR MIXES
DOWN AND WINDS BECOME MORE UNIDIRECTIONAL. THE FREEZING LEVEL IS
NEAR 13000 FEET WHICH IS HIGH...BUT THERE WAS A REPORT EARLIER IN
THE NIGHT OF 1.25 INCH DIAMETER HAIL IN ASCENSION PARISH. 0-1KM
SRH AND 0-3KM SRH IS IMPRESSIVE AT 200 AND 340 M2/S2 RESPECTIVELY.
WINDS ARE FROM THE SOUTHEAST AT THE SURFACE AND THEN ARE
PREDOMINATELY FROM THE SOUTHWEST. SO THERE IS LOW LEVEL
DIRECTIONAL SHEAR CURRENTLY. THERE IS ALSO SOME SPEED SHEAR WITH
950MB AT 15 KNOTS...850MB AT 33 KNOTS...700MB AT 51 KNOTS...500MB
IS AT 58 KNOTS. A PEAK WIND SPEED OF 103 KNOTS WAS AT 39000 FEET
WITH A STORM TOP WIND SPEED NEAR 48000 FEET OF 72 KNOTS.
SPC HAS REQUESTED AN 18Z SOUNDING IN SUPPORT OF SEVERE WEATHER
OPERATIONS.
12Z BALLOON INFO: A SUCCESSFUL FLIGHT LASTING 85 MINUTES AND
REACHING A HEIGHT OF 14.8 MILES ABOVE THE GROUND. THE BALLOON
BURST OVER NEELY 84 MILES DOWNRANGE FROM THE OFFICE.
ANSORGE
PREV DISCUSSION... /ISSUED 406 AM CST WED DEC 23 2015/
SHORT TERM... ACTIVE CONDITIONS ONGOING ACROSS THE FORECAST AREA
THIS MORNING. LOCAL VAD WIND PROFILE SHOWS THAT LOW LEVEL WINDS HAVE
INCREASES SUBSTANTIALLY OVER THE LAST FEW HOURS WITH SE FLOW OF 30
KNOTS AT THE LOWEST OBS OF 1KFT AND VEERING TO SW WHILE INCREASING
TO 50KTS IN THE MID LEVELS. THIS IS THE PRIMARY REASON FOR THE
RECENT RAMP UP OF STRONG/SEVERE THUNDERSTORMS EARLY THIS MORNING.
HAVE RECEIVED 1 REPORT OF HAIL AND SEVERAL CELLS HAVE BROAD
ROTATION...INDICATIVE OF INCREASING SRH. THIS IS ALL HAPPENING
DESPITE BEING WITHIN A MARINE LAYER. THE TREND OF ACTIVE WEATHER
WITH THE POTENTIAL FOR A FEW CELLS PRODUCING HAIL OR A TORNADO WILL
CONTINUE THROUGH THE REST OF THE EARLY MORNING HOURS. THE BULK OF
STRONGER STORMS WILL SHIFT NORTHEAST AFTER SUNRISE AS SHORT WAVE
VORTMAX DOES SO AS WELL.
MOISTURE LEVELS REMAIN VERY HIGH ACROSS THE CENTRAL GULF COAST THIS
MORNING WITH THE 00Z SOUNDING FROM YESTERDAY AFTERNOON HAVING A
PRECIP WATER VALUE OF AROUND 1.7 INCHES WHICH IS RIGHT AT THE
CLIMATOLOGY MAX PER SPC SOUNDING INFO. BROAD LONG WAVE TROUGH IS
ALREADY IN PLACE OVER THE WESTERN HALF OF THE COUNTRY. AN EMBEDDED
WAVE WILL DIG AND SWING NEGATIVE OVER THE CENTRAL PLAINS TODAY. DOWN
AT THE SURFACE A LOW ON THE LEESIDE OF THE ROCKIES WILL BE RACING
NORTHEAST ACROSS THE CENTRAL MISSISSIPPI VALLEY. SURFACE PRESSURES
IN THE CWA WILL BE SLOWLY FALLING DURING THE DAY WITH A MINIMUM OF
APPROACHING 1000MB BY NOON BASED ON RUC OUTPUT. TIGHTENING OF THE
PRESSURE GRADIENT WILL INCREASE SURFACE WINDS INTO THE 15 TO 25
MPH RANGE. THIS SHOULD DO 2 THINGS...TRANSPORT OFFSHORE 70+DEGREE
DEWPOINTS FURTHER INLAND AS WELL AS INCREASE LOW LEVEL WIND SHEAR
SUBSTANTIALLY. HELICITY LIKELY TO FALL SOME AS WIND DIRECTION
BECOMES MORE CLOSELY ORIENTED TO THE MEAN FLOW OR MORE SOUTH TO
SOUTH WEST RATHER THAN CURRENT SOUTHEAST DIRECTION. PRESUMING THAT
SFC TEMPS DO REACH MID/UPPER 70S WHILE THESE DEWPOINTS
RISE...BUOYANCY AND INSTABILITY WILL SHOOT UP DURING THE DAY. BOTH
GFS AND NAM BUFR SOUNDINGS STILL SHOW SB AND PARCEL CAPE VALUES
WELL OVER 2000 J/KG AND MU CAPE UP TO 1500 J/KG ALL OVER THE CWA.
SPEED SHEAR LOOKING TO BE 40 TO 50 KNOTS IN THE BOUNDARY LAYER
WHICH IS PLENTY STRONG TO SUSTAIN SUPERCELLS. THUS THE POTENTIAL
FOR SEVERE WEATHER WILL DEFINITELY BE THERE TODAY. ALL MODES OF
SEVERE WEATHER ARE POSSIBLE. STILL OF CONCERN IS IF SFC TEMPS DONT
WARM ENOUGH... WILL JUST HAVE THE DYNAMICS. TOO STRONG OF A WARM
NOSE IN THE LOWER LEVELS COULD CAP THINGS AS WELL REGARDLESS...THE
POTENTIAL IS DEFINITELY THERE AND WARRANTS THE SLIGHT RISK AT THE
LEAST FOR THE ENTIRE CWA.
LONG TERM... RESIDUAL SURFACE BOUNDARY WILL BE THE FOCUS FOR
CONVECTION ON THURSDAY. AMPLE MOISTURE STILL LEFT IN THE AREA SHOULD
HAVE NO PROBLEM DEVELOPING INTO SHOWERS WITH POSSIBLY A FEW
THUNDERSTORMS. MUCH WEAKER WINDS IN THE COLUMN WILL LIMIT
ORGANIZATION OF STORMS BUT WONT BE SHORT OF INSTABILITY.
COVERAGE SHOULD STILL BE 50 TO 70 PERCENT FOR THE MOST PART.
CHRISTMAS DAY SHOULD BEGIN THE DOWNWARD TREND OF POPS AS UPPER LEVEL
RIDGE CENTERED OVER THE WESTERN ATLANTIC BUILDS BACK WESTWARD ACROSS
THE CWA. DESPITE THIS DECREASE IN COVERAGE...STILL PROBABLY LOOKING
AT 20 TO 30 PERCENT RAIN CHANCE. NO CHANCE IN THE TEMP FORECAST AND
EXPECTING NEAR RECORD MAX TEMPS AND RECORD HIGH LOWS. SADLY...THERE
IS A ZERO PERCENT CHANCE FOR A WHITE CHRISTMAS.
POPS TO FALL EVEN MORE DOWN INTO THE SLIGHT CHANCE CATEGORY THIS
WEEKEND AS THE RIDGE SHIFTS THE SHEAR ZONE FURTHER NORTH AND WEST.
GFS AND ECMWF BOTH CLOSE OFF A LOW IN THE DESERT SOUTHWEST AND
TRACKS EAST BEFORE SWINGING NE OVER THE CENTRAL PLAINS ENDING THE
WEEKEND. THIS WOULD BRING A LINE OF SHOWERS AND STORMS MOVING THRU
SOME TIME BETWEEN SUNDAY NIGHT AND MONDAY NIGHT DEPENDING ON MODEL
TIMING. NUDGED THE POPS TO THE SLOWER SOLUTION AS THE FASTER GFS IS
CLOSER TO AN OUTLIER SIDE OF THINGS.
MEFFER
AVIATION... SEVERE WEATHER CAME IN A LITTLE EARLIER TODAY THAN
EXPECTED. WILL KEEP THAT THREAT GOING THROUGH THE DAY BUT EXPECT A
REPRIEVE FOR SEVERAL HOURS AFTER DAYLIGHT TODAY. ANOTHER ROUND WILL
BE POSSIBLE THIS AFTERNOON BUT WILL HAVE TO SEE HOW THIS SHAPES UP.
CEILINGS WILL REMAIN FROM OVC020 TO OVC030 TODAY AND TONIGHT. RAIN
WILL ALSO CEASE FOR A WHILE TODAY AND WILL SHOW THIS IN THE 12Z TAF
PACKAGE.
WILL TAKE ANOTHER LOOK AT WX IN TAF SET LATER THIS MORNING.
MARINE... AS UPPER SYSTEM SWINGS THROUGH THE MIDDLE MISSISSIPPI
RIVER VALLEY TODAY...PRESSURE GRADIENT WILL TIGHTEN AND SMALL CRAFT
ADVISORIES AND EXERCISE CAUTION HEADLINES HAVE BEEN ISSUED AHEAD OF
THE SYSTEM. THIS SHOULD BE SOMEWHAT SHORT LIVED AS WINDS SUBSIDE
TONIGHT. NEXT PERIOD OF HEADLINES WILL BE EXERCISE CAUTION HEADLINES
OVER THE WEEKEND AS ONSHORE FLOW AGAIN STRENGTHENS.
DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING CONVECTIVE TRENDS.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 78 64 77 68 / 90 70 60 40
BTR 79 65 79 70 / 80 70 50 30
ASD 75 67 76 68 / 90 70 70 30
MSY 78 69 76 69 / 80 70 70 30
GPT 73 68 74 68 / 90 70 70 30
PQL 74 69 74 68 / 80 70 70 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ536-538-
550-552-555-557-570-572-575-577.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ538-550-
552-555-557-570-572-575-577.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
1210 PM CST WED DEC 23 2015
.MARINE...
GRADIENT FLOW HAS INCREASED MORE THAN ORIGINALLY ANTICIPATED
ACROSS THE SOUNDS AND LAKES THIS MORNING. AS A RESULT...SOUTHERLY
WINDS ARE IN SMALL CRAFT ADVISORY RANGE OF 20 TO 25 KNOTS AND THE
SMALL CRAFT EXERCISE CAUTION FLAGS HAVE BEEN UPGRADED TO ADVISORY
FLAGS. THESE STRONGER WINDS SHOULD PERSIST THROUGH THE AFTERNOON
HOURS IN ADVANCE OF A DEEPENING LOW PRESSURE SYSTEM OVER THE
MIDWESTERN STATES. THE GRADIENT FLOW SHOULD RELAX SOMEWHAT TONIGHT
AS THE LOW PULLS TO THE NORTHEAST AND A FRONTAL BOUNDARY STALLS
OVER THE REGION. 32
&&
.PREV DISCUSSION... /ISSUED 900 AM CST WED DEC 23 2015/
UPDATE...
OVERALL CONVECTIVE COVERAGE HAS DECREASED THIS MORNING AS THE
REGION HAS STABALIZED A BIT IN THE WAKE OF THE RAINFALL THAT
OCCURRED EARLIER TODAY. GIVEN THIS TREND...HAVE LOWERED POPS FOR
THE FORECAST AREA THROUGH THE EARLY AFTERNOON HOURS INTO THE
CHANCE RANGE FROM CATEGORICAL. HOWEVER...ANOTHER ROUND OF
CONVECTIVE DEVELOPMENT STILL LOOKS LIKELY FROM MID-AFTERNOON
THROUGH THE EVENING HOURS AS THE ATMOSPHERE WARMS AND TURNS MORE
UNSTABLE. ADDITIONALLY...ANOTHER UPPER LEVEL IMPULSE OF INCREASED
VORTICITY AND OMEGA WILL SLIDE THROUGH THE LOWER MISSISSIPPI
VALLEY DURING THE AFTERNOON HOURS. THIS INCREASE IN LIFT ALOFT
SHOULD PROVIDE ENOUGH OF A CATALYST TO FIRE OFF ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. HAVE LIKELY POPS IN PLACE FOR THE LATE
AFTERNOON AND EVENING HOURS TO REFLECT THIS RISK. OUTSIDE OF THE
POP ADJUSTMENTS...NO OTHER FORECAST CHANGES WERE MADE AT THIS
TIME. 32
PREV DISCUSSION... /ISSUED 758 AM CST WED DEC 23 2015/
.SOUNDING DISCUSSION...
BOTTOM LINE UP FRONT...ALL MODES OF SEVERE WEATHER REMAIN POSSIBLE
TODAY. A VERY MOIST ATMOSPHERE WAS SAMPLED THIS MORNING WITH A
PRECIPITABLE WATER VALUE OF 1.74 INCHES. THIS IS 2 STANDARD
DEVIATIONS ABOVE NORMAL AND A RECORD VALUE FOR THIS DATE/TIME.
MOST UNSTABLE CAPE OF ABOUT 1200 J/KG EXISTS WITH INHIBITION IN
THE FORM OF A CAPPING INVERSION. ASSUMING LOW CLOUDS AND FOG
DISSIPATE AND WE HAVE SOME SURFACE HEATING...THIS CAPPING
INVERSION SHOULD ERODE. WITH QUITE A BIT OF MOISTURE IN THE LOW-
LEVELS...THE DOWNDRAFT CAPE IS NOT IN THE OPTIMUM RANGE FOR
DAMAGING STRAIGHT LINE WINDS. THIS MAY CHANGE IF DRIER AIR MIXES
DOWN AND WINDS BECOME MORE UNIDIRECTIONAL. THE FREEZING LEVEL IS
NEAR 13000 FEET WHICH IS HIGH...BUT THERE WAS A REPORT EARLIER IN
THE NIGHT OF 1.25 INCH DIAMETER HAIL IN ASCENSION PARISH. 0-1KM
SRH AND 0-3KM SRH IS IMPRESSIVE AT 200 AND 340 M2/S2 RESPECTIVELY.
WINDS ARE FROM THE SOUTHEAST AT THE SURFACE AND THEN ARE
PREDOMINATELY FROM THE SOUTHWEST. SO THERE IS LOW LEVEL
DIRECTIONAL SHEAR CURRENTLY. THERE IS ALSO SOME SPEED SHEAR WITH
950MB AT 15 KNOTS...850MB AT 33 KNOTS...700MB AT 51 KNOTS...500MB
IS AT 58 KNOTS. A PEAK WIND SPEED OF 103 KNOTS WAS AT 39000 FEET
WITH A STORM TOP WIND SPEED NEAR 48000 FEET OF 72 KNOTS.
SPC HAS REQUESTED AN 18Z SOUNDING IN SUPPORT OF SEVERE WEATHER
OPERATIONS.
12Z BALLOON INFO: A SUCCESSFUL FLIGHT LASTING 85 MINUTES AND
REACHING A HEIGHT OF 14.8 MILES ABOVE THE GROUND. THE BALLOON
BURST OVER NEELY 84 MILES DOWNRANGE FROM THE OFFICE.
ANSORGE
PREV DISCUSSION... /ISSUED 406 AM CST WED DEC 23 2015/
SHORT TERM... ACTIVE CONDITIONS ONGOING ACROSS THE FORECAST AREA
THIS MORNING. LOCAL VAD WIND PROFILE SHOWS THAT LOW LEVEL WINDS HAVE
INCREASES SUBSTANTIALLY OVER THE LAST FEW HOURS WITH SE FLOW OF 30
KNOTS AT THE LOWEST OBS OF 1KFT AND VEERING TO SW WHILE INCREASING
TO 50KTS IN THE MID LEVELS. THIS IS THE PRIMARY REASON FOR THE
RECENT RAMP UP OF STRONG/SEVERE THUNDERSTORMS EARLY THIS MORNING.
HAVE RECEIVED 1 REPORT OF HAIL AND SEVERAL CELLS HAVE BROAD
ROTATION...INDICATIVE OF INCREASING SRH. THIS IS ALL HAPPENING
DESPITE BEING WITHIN A MARINE LAYER. THE TREND OF ACTIVE WEATHER
WITH THE POTENTIAL FOR A FEW CELLS PRODUCING HAIL OR A TORNADO WILL
CONTINUE THROUGH THE REST OF THE EARLY MORNING HOURS. THE BULK OF
STRONGER STORMS WILL SHIFT NORTHEAST AFTER SUNRISE AS SHORT WAVE
VORTMAX DOES SO AS WELL.
MOISTURE LEVELS REMAIN VERY HIGH ACROSS THE CENTRAL GULF COAST THIS
MORNING WITH THE 00Z SOUNDING FROM YESTERDAY AFTERNOON HAVING A
PRECIP WATER VALUE OF AROUND 1.7 INCHES WHICH IS RIGHT AT THE
CLIMATOLOGY MAX PER SPC SOUNDING INFO. BROAD LONG WAVE TROUGH IS
ALREADY IN PLACE OVER THE WESTERN HALF OF THE COUNTRY. AN EMBEDDED
WAVE WILL DIG AND SWING NEGATIVE OVER THE CENTRAL PLAINS TODAY. DOWN
AT THE SURFACE A LOW ON THE LEESIDE OF THE ROCKIES WILL BE RACING
NORTHEAST ACROSS THE CENTRAL MISSISSIPPI VALLEY. SURFACE PRESSURES
IN THE CWA WILL BE SLOWLY FALLING DURING THE DAY WITH A MINIMUM OF
APPROACHING 1000MB BY NOON BASED ON RUC OUTPUT. TIGHTENING OF THE
PRESSURE GRADIENT WILL INCREASE SURFACE WINDS INTO THE 15 TO 25
MPH RANGE. THIS SHOULD DO 2 THINGS...TRANSPORT OFFSHORE 70+DEGREE
DEWPOINTS FURTHER INLAND AS WELL AS INCREASE LOW LEVEL WIND SHEAR
SUBSTANTIALLY. HELICITY LIKELY TO FALL SOME AS WIND DIRECTION
BECOMES MORE CLOSELY ORIENTED TO THE MEAN FLOW OR MORE SOUTH TO
SOUTH WEST RATHER THAN CURRENT SOUTHEAST DIRECTION. PRESUMING THAT
SFC TEMPS DO REACH MID/UPPER 70S WHILE THESE DEWPOINTS
RISE...BUOYANCY AND INSTABILITY WILL SHOOT UP DURING THE DAY. BOTH
GFS AND NAM BUFR SOUNDINGS STILL SHOW SB AND PARCEL CAPE VALUES
WELL OVER 2000 J/KG AND MU CAPE UP TO 1500 J/KG ALL OVER THE CWA.
SPEED SHEAR LOOKING TO BE 40 TO 50 KNOTS IN THE BOUNDARY LAYER
WHICH IS PLENTY STRONG TO SUSTAIN SUPERCELLS. THUS THE POTENTIAL
FOR SEVERE WEATHER WILL DEFINITELY BE THERE TODAY. ALL MODES OF
SEVERE WEATHER ARE POSSIBLE. STILL OF CONCERN IS IF SFC TEMPS DONT
WARM ENOUGH... WILL JUST HAVE THE DYNAMICS. TOO STRONG OF A WARM
NOSE IN THE LOWER LEVELS COULD CAP THINGS AS WELL REGARDLESS...THE
POTENTIAL IS DEFINITELY THERE AND WARRANTS THE SLIGHT RISK AT THE
LEAST FOR THE ENTIRE CWA.
LONG TERM... RESIDUAL SURFACE BOUNDARY WILL BE THE FOCUS FOR
CONVECTION ON THURSDAY. AMPLE MOISTURE STILL LEFT IN THE AREA SHOULD
HAVE NO PROBLEM DEVELOPING INTO SHOWERS WITH POSSIBLY A FEW
THUNDERSTORMS. MUCH WEAKER WINDS IN THE COLUMN WILL LIMIT
ORGANIZATION OF STORMS BUT WONT BE SHORT OF INSTABILITY.
COVERAGE SHOULD STILL BE 50 TO 70 PERCENT FOR THE MOST PART.
CHRISTMAS DAY SHOULD BEGIN THE DOWNWARD TREND OF POPS AS UPPER LEVEL
RIDGE CENTERED OVER THE WESTERN ATLANTIC BUILDS BACK WESTWARD ACROSS
THE CWA. DESPITE THIS DECREASE IN COVERAGE...STILL PROBABLY LOOKING
AT 20 TO 30 PERCENT RAIN CHANCE. NO CHANCE IN THE TEMP FORECAST AND
EXPECTING NEAR RECORD MAX TEMPS AND RECORD HIGH LOWS. SADLY...THERE
IS A ZERO PERCENT CHANCE FOR A WHITE CHRISTMAS.
POPS TO FALL EVEN MORE DOWN INTO THE SLIGHT CHANCE CATEGORY THIS
WEEKEND AS THE RIDGE SHIFTS THE SHEAR ZONE FURTHER NORTH AND WEST.
GFS AND ECMWF BOTH CLOSE OFF A LOW IN THE DESERT SOUTHWEST AND
TRACKS EAST BEFORE SWINGING NE OVER THE CENTRAL PLAINS ENDING THE
WEEKEND. THIS WOULD BRING A LINE OF SHOWERS AND STORMS MOVING THRU
SOME TIME BETWEEN SUNDAY NIGHT AND MONDAY NIGHT DEPENDING ON MODEL
TIMING. NUDGED THE POPS TO THE SLOWER SOLUTION AS THE FASTER GFS IS
CLOSER TO AN OUTLIER SIDE OF THINGS.
MEFFER
AVIATION... SEVERE WEATHER CAME IN A LITTLE EARLIER TODAY THAN
EXPECTED. WILL KEEP THAT THREAT GOING THROUGH THE DAY BUT EXPECT A
REPRIEVE FOR SEVERAL HOURS AFTER DAYLIGHT TODAY. ANOTHER ROUND WILL
BE POSSIBLE THIS AFTERNOON BUT WILL HAVE TO SEE HOW THIS SHAPES UP.
CEILINGS WILL REMAIN FROM OVC020 TO OVC030 TODAY AND TONIGHT. RAIN
WILL ALSO CEASE FOR A WHILE TODAY AND WILL SHOW THIS IN THE 12Z TAF
PACKAGE.
WILL TAKE ANOTHER LOOK AT WX IN TAF SET LATER THIS MORNING.
MARINE... AS UPPER SYSTEM SWINGS THROUGH THE MIDDLE MISSISSIPPI
RIVER VALLEY TODAY...PRESSURE GRADIENT WILL TIGHTEN AND SMALL CRAFT
ADVISORIES AND EXERCISE CAUTION HEADLINES HAVE BEEN ISSUED AHEAD OF
THE SYSTEM. THIS SHOULD BE SOMEWHAT SHORT LIVED AS WINDS SUBSIDE
TONIGHT. NEXT PERIOD OF HEADLINES WILL BE EXERCISE CAUTION HEADLINES
OVER THE WEEKEND AS ONSHORE FLOW AGAIN STRENGTHENS.
DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING CONVECTIVE TRENDS.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 64 77 68 77 / 70 60 40 30
BTR 65 79 70 79 / 70 50 30 40
ASD 67 76 68 77 / 70 70 30 30
MSY 69 76 69 77 / 70 70 30 30
GPT 68 74 68 74 / 70 70 30 20
PQL 69 74 68 75 / 70 70 30 20
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ530-532-
534-536-538-550-552-555-557-570-572-575-577.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ532-534-
536-538-550-552-555-557-570-572-575-577.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
900 AM CST WED DEC 23 2015
.UPDATE...
OVERALL CONVECTIVE COVERAGE HAS DECREASED THIS MORNING AS THE
REGION HAS STABALIZED A BIT IN THE WAKE OF THE RAINFALL THAT
OCCURRED EARLIER TODAY. GIVEN THIS TREND...HAVE LOWERED POPS FOR
THE FORECAST AREA THROUGH THE EARLY AFTERNOON HOURS INTO THE
CHANCE RANGE FROM CATEGORICAL. HOWEVER...ANOTHER ROUND OF
CONVECTIVE DEVELOPMENT STILL LOOKS LIKELY FROM MID-AFTERNOON
THROUGH THE EVENING HOURS AS THE ATMOSPHERE WARMS AND TURNS MORE
UNSTABLE. ADDITIONALLY...ANOTHER UPPER LEVEL IMPULSE OF INCREASED
VORTICITY AND OMEGA WILL SLIDE THROUGH THE LOWER MISSISSIPPI
VALLEY DURING THE AFTERNOON HOURS. THIS INCREASE IN LIFT ALOFT
SHOULD PROVIDE ENOUGH OF A CATALYST TO FIRE OFF ANOTHER ROUND OF
SHOWERS AND THUNDERSTORMS. HAVE LIKELY POPS IN PLACE FOR THE LATE
AFTERNOON AND EVENING HOURS TO REFLECT THIS RISK. OUTSIDE OF THE
POP ADJUSTMENTS...NO OTHER FORECAST CHANGES WERE MADE AT THIS
TIME. 32
&&
.PREV DISCUSSION... /ISSUED 758 AM CST WED DEC 23 2015/
..SOUNDING DISCUSSION...
BOTTOM LINE UP FRONT...ALL MODES OF SEVERE WEATHER REMAIN POSSIBLE
TODAY. A VERY MOIST ATMOSPHERE WAS SAMPLED THIS MORNING WITH A
PRECIPITABLE WATER VALUE OF 1.74 INCHES. THIS IS 2 STANDARD
DEVIATIONS ABOVE NORMAL AND A RECORD VALUE FOR THIS DATE/TIME.
MOST UNSTABLE CAPE OF ABOUT 1200 J/KG EXISTS WITH INHIBITION IN
THE FORM OF A CAPPING INVERSION. ASSUMING LOW CLOUDS AND FOG
DISSIPATE AND WE HAVE SOME SURFACE HEATING...THIS CAPPING
INVERSION SHOULD ERODE. WITH QUITE A BIT OF MOISTURE IN THE LOW-
LEVELS...THE DOWNDRAFT CAPE IS NOT IN THE OPTIMUM RANGE FOR
DAMAGING STRAIGHT LINE WINDS. THIS MAY CHANGE IF DRIER AIR MIXES
DOWN AND WINDS BECOME MORE UNIDIRECTIONAL. THE FREEZING LEVEL IS
NEAR 13000 FEET WHICH IS HIGH...BUT THERE WAS A REPORT EARLIER IN
THE NIGHT OF 1.25 INCH DIAMETER HAIL IN ASCENSION PARISH. 0-1KM
SRH AND 0-3KM SRH IS IMPRESSIVE AT 200 AND 340 M2/S2 RESPECTIVELY.
WINDS ARE FROM THE SOUTHEAST AT THE SURFACE AND THEN ARE
PREDOMINATELY FROM THE SOUTHWEST. SO THERE IS LOW LEVEL
DIRECTIONAL SHEAR CURRENTLY. THERE IS ALSO SOME SPEED SHEAR WITH
950MB AT 15 KNOTS...850MB AT 33 KNOTS...700MB AT 51 KNOTS...500MB
IS AT 58 KNOTS. A PEAK WIND SPEED OF 103 KNOTS WAS AT 39000 FEET
WITH A STORM TOP WIND SPEED NEAR 48000 FEET OF 72 KNOTS.
SPC HAS REQUESTED AN 18Z SOUNDING IN SUPPORT OF SEVERE WEATHER
OPERATIONS.
12Z BALLOON INFO: A SUCCESSFUL FLIGHT LASTING 85 MINUTES AND
REACHING A HEIGHT OF 14.8 MILES ABOVE THE GROUND. THE BALLOON
BURST OVER NEELY 84 MILES DOWNRANGE FROM THE OFFICE.
ANSORGE
PREV DISCUSSION... /ISSUED 406 AM CST WED DEC 23 2015/
SHORT TERM... ACTIVE CONDITIONS ONGOING ACROSS THE FORECAST AREA
THIS MORNING. LOCAL VAD WIND PROFILE SHOWS THAT LOW LEVEL WINDS HAVE
INCREASES SUBSTANTIALLY OVER THE LAST FEW HOURS WITH SE FLOW OF 30
KNOTS AT THE LOWEST OBS OF 1KFT AND VEERING TO SW WHILE INCREASING
TO 50KTS IN THE MID LEVELS. THIS IS THE PRIMARY REASON FOR THE
RECENT RAMP UP OF STRONG/SEVERE THUNDERSTORMS EARLY THIS MORNING.
HAVE RECEIVED 1 REPORT OF HAIL AND SEVERAL CELLS HAVE BROAD
ROTATION...INDICATIVE OF INCREASING SRH. THIS IS ALL HAPPENING
DESPITE BEING WITHIN A MARINE LAYER. THE TREND OF ACTIVE WEATHER
WITH THE POTENTIAL FOR A FEW CELLS PRODUCING HAIL OR A TORNADO WILL
CONTINUE THROUGH THE REST OF THE EARLY MORNING HOURS. THE BULK OF
STRONGER STORMS WILL SHIFT NORTHEAST AFTER SUNRISE AS SHORT WAVE
VORTMAX DOES SO AS WELL.
MOISTURE LEVELS REMAIN VERY HIGH ACROSS THE CENTRAL GULF COAST THIS
MORNING WITH THE 00Z SOUNDING FROM YESTERDAY AFTERNOON HAVING A
PRECIP WATER VALUE OF AROUND 1.7 INCHES WHICH IS RIGHT AT THE
CLIMATOLOGY MAX PER SPC SOUNDING INFO. BROAD LONG WAVE TROUGH IS
ALREADY IN PLACE OVER THE WESTERN HALF OF THE COUNTRY. AN EMBEDDED
WAVE WILL DIG AND SWING NEGATIVE OVER THE CENTRAL PLAINS TODAY. DOWN
AT THE SURFACE A LOW ON THE LEESIDE OF THE ROCKIES WILL BE RACING
NORTHEAST ACROSS THE CENTRAL MISSISSIPPI VALLEY. SURFACE PRESSURES
IN THE CWA WILL BE SLOWLY FALLING DURING THE DAY WITH A MINIMUM OF
APPROACHING 1000MB BY NOON BASED ON RUC OUTPUT. TIGHTENING OF THE
PRESSURE GRADIENT WILL INCREASE SURFACE WINDS INTO THE 15 TO 25
MPH RANGE. THIS SHOULD DO 2 THINGS...TRANSPORT OFFSHORE 70+DEGREE
DEWPOINTS FURTHER INLAND AS WELL AS INCREASE LOW LEVEL WIND SHEAR
SUBSTANTIALLY. HELICITY LIKELY TO FALL SOME AS WIND DIRECTION
BECOMES MORE CLOSELY ORIENTED TO THE MEAN FLOW OR MORE SOUTH TO
SOUTH WEST RATHER THAN CURRENT SOUTHEAST DIRECTION. PRESUMING THAT
SFC TEMPS DO REACH MID/UPPER 70S WHILE THESE DEWPOINTS
RISE...BUOYANCY AND INSTABILITY WILL SHOOT UP DURING THE DAY. BOTH
GFS AND NAM BUFR SOUNDINGS STILL SHOW SB AND PARCEL CAPE VALUES
WELL OVER 2000 J/KG AND MU CAPE UP TO 1500 J/KG ALL OVER THE CWA.
SPEED SHEAR LOOKING TO BE 40 TO 50 KNOTS IN THE BOUNDARY LAYER
WHICH IS PLENTY STRONG TO SUSTAIN SUPERCELLS. THUS THE POTENTIAL
FOR SEVERE WEATHER WILL DEFINITELY BE THERE TODAY. ALL MODES OF
SEVERE WEATHER ARE POSSIBLE. STILL OF CONCERN IS IF SFC TEMPS DONT
WARM ENOUGH... WILL JUST HAVE THE DYNAMICS. TOO STRONG OF A WARM
NOSE IN THE LOWER LEVELS COULD CAP THINGS AS WELL REGARDLESS...THE
POTENTIAL IS DEFINITELY THERE AND WARRANTS THE SLIGHT RISK AT THE
LEAST FOR THE ENTIRE CWA.
LONG TERM... RESIDUAL SURFACE BOUNDARY WILL BE THE FOCUS FOR
CONVECTION ON THURSDAY. AMPLE MOISTURE STILL LEFT IN THE AREA SHOULD
HAVE NO PROBLEM DEVELOPING INTO SHOWERS WITH POSSIBLY A FEW
THUNDERSTORMS. MUCH WEAKER WINDS IN THE COLUMN WILL LIMIT
ORGANIZATION OF STORMS BUT WONT BE SHORT OF INSTABILITY.
COVERAGE SHOULD STILL BE 50 TO 70 PERCENT FOR THE MOST PART.
CHRISTMAS DAY SHOULD BEGIN THE DOWNWARD TREND OF POPS AS UPPER LEVEL
RIDGE CENTERED OVER THE WESTERN ATLANTIC BUILDS BACK WESTWARD ACROSS
THE CWA. DESPITE THIS DECREASE IN COVERAGE...STILL PROBABLY LOOKING
AT 20 TO 30 PERCENT RAIN CHANCE. NO CHANCE IN THE TEMP FORECAST AND
EXPECTING NEAR RECORD MAX TEMPS AND RECORD HIGH LOWS. SADLY...THERE
IS A ZERO PERCENT CHANCE FOR A WHITE CHRISTMAS.
POPS TO FALL EVEN MORE DOWN INTO THE SLIGHT CHANCE CATEGORY THIS
WEEKEND AS THE RIDGE SHIFTS THE SHEAR ZONE FURTHER NORTH AND WEST.
GFS AND ECMWF BOTH CLOSE OFF A LOW IN THE DESERT SOUTHWEST AND
TRACKS EAST BEFORE SWINGING NE OVER THE CENTRAL PLAINS ENDING THE
WEEKEND. THIS WOULD BRING A LINE OF SHOWERS AND STORMS MOVING THRU
SOME TIME BETWEEN SUNDAY NIGHT AND MONDAY NIGHT DEPENDING ON MODEL
TIMING. NUDGED THE POPS TO THE SLOWER SOLUTION AS THE FASTER GFS IS
CLOSER TO AN OUTLIER SIDE OF THINGS.
MEFFER
AVIATION... SEVERE WEATHER CAME IN A LITTLE EARLIER TODAY THAN
EXPECTED. WILL KEEP THAT THREAT GOING THROUGH THE DAY BUT EXPECT A
REPRIEVE FOR SEVERAL HOURS AFTER DAYLIGHT TODAY. ANOTHER ROUND WILL
BE POSSIBLE THIS AFTERNOON BUT WILL HAVE TO SEE HOW THIS SHAPES UP.
CEILINGS WILL REMAIN FROM OVC020 TO OVC030 TODAY AND TONIGHT. RAIN
WILL ALSO CEASE FOR A WHILE TODAY AND WILL SHOW THIS IN THE 12Z TAF
PACKAGE.
WILL TAKE ANOTHER LOOK AT WX IN TAF SET LATER THIS MORNING.
MARINE... AS UPPER SYSTEM SWINGS THROUGH THE MIDDLE MISSISSIPPI
RIVER VALLEY TODAY...PRESSURE GRADIENT WILL TIGHTEN AND SMALL CRAFT
ADVISORIES AND EXERCISE CAUTION HEADLINES HAVE BEEN ISSUED AHEAD OF
THE SYSTEM. THIS SHOULD BE SOMEWHAT SHORT LIVED AS WINDS SUBSIDE
TONIGHT. NEXT PERIOD OF HEADLINES WILL BE EXERCISE CAUTION HEADLINES
OVER THE WEEKEND AS ONSHORE FLOW AGAIN STRENGTHENS.
DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING CONVECTIVE TRENDS.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 78 64 77 68 / 90 70 60 40
BTR 79 65 79 70 / 80 70 50 30
ASD 75 67 76 68 / 90 70 70 30
MSY 78 69 76 69 / 80 70 70 30
GPT 73 68 74 68 / 90 70 70 30
PQL 74 69 74 68 / 80 70 70 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ536-538-
550-552-555-557-570-572-575-577.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ538-550-
552-555-557-570-572-575-577.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
758 AM CST WED DEC 23 2015
...SOUNDING DISCUSSION...
BOTTOM LINE UP FRONT...ALL MODES OF SEVERE WEATHER REMAIN POSSIBLE
TODAY. A VERY MOIST ATMOSPHERE WAS SAMPLED THIS MORNING WITH A
PRECIPITABLE WATER VALUE OF 1.74 INCHES. THIS IS 2 STANDARD
DEVIATIONS ABOVE NORMAL AND A RECORD VALUE FOR THIS DATE/TIME.
MOST UNSTABLE CAPE OF ABOUT 1200 J/KG EXISTS WITH INHIBITION IN
THE FORM OF A CAPPING INVERSION. ASSUMING LOW CLOUDS AND FOG
DISSIPATE AND WE HAVE SOME SURFACE HEATING...THIS CAPPING
INVERSION SHOULD ERODE. WITH QUITE A BIT OF MOISTURE IN THE LOW-
LEVELS...THE DOWNDRAFT CAPE IS NOT IN THE OPTIMUM RANGE FOR
DAMAGING STRAIGHT LINE WINDS. THIS MAY CHANGE IF DRIER AIR MIXES
DOWN AND WINDS BECOME MORE UNIDIRECTIONAL. THE FREEZING LEVEL IS
NEAR 13000 FEET WHICH IS HIGH...BUT THERE WAS A REPORT EARLIER IN
THE NIGHT OF 1.25 INCH DIAMETER HAIL IN ASCENSION PARISH. 0-1KM
SRH AND 0-3KM SRH IS IMPRESSIVE AT 200 AND 340 M2/S2 RESPECTIVELY.
WINDS ARE FROM THE SOUTHEAST AT THE SURFACE AND THEN ARE
PREDOMINATELY FROM THE SOUTHWEST. SO THERE IS LOW LEVEL
DIRECTIONAL SHEAR CURRENTLY. THERE IS ALSO SOME SPEED SHEAR WITH
950MB AT 15 KNOTS...850MB AT 33 KNOTS...700MB AT 51 KNOTS...500MB
IS AT 58 KNOTS. A PEAK WIND SPEED OF 103 KNOTS WAS AT 39000 FEET
WITH A STORM TOP WIND SPEED NEAR 48000 FEET OF 72 KNOTS.
SPC HAS REQUESTED AN 18Z SOUNDING IN SUPPORT OF SEVERE WEATHER
OPERATIONS.
12Z BALLOON INFO: A SUCCESSFUL FLIGHT LASTING 85 MINUTES AND
REACHING A HEIGHT OF 14.8 MILES ABOVE THE GROUND. THE BALLOON
BURST OVER NEELY 84 MILES DOWNRANGE FROM THE OFFICE.
ANSORGE
&&
.PREV DISCUSSION... /ISSUED 406 AM CST WED DEC 23 2015/
SHORT TERM... ACTIVE CONDITIONS ONGOING ACROSS THE FORECAST AREA
THIS MORNING. LOCAL VAD WIND PROFILE SHOWS THAT LOW LEVEL WINDS HAVE
INCREASES SUBSTANTIALLY OVER THE LAST FEW HOURS WITH SE FLOW OF 30
KNOTS AT THE LOWEST OBS OF 1KFT AND VEERING TO SW WHILE INCREASING
TO 50KTS IN THE MID LEVELS. THIS IS THE PRIMARY REASON FOR THE
RECENT RAMP UP OF STRONG/SEVERE THUNDERSTORMS EARLY THIS MORNING.
HAVE RECEIVED 1 REPORT OF HAIL AND SEVERAL CELLS HAVE BROAD
ROTATION...INDICATIVE OF INCREASING SRH. THIS IS ALL HAPPENING
DESPITE BEING WITHIN A MARINE LAYER. THE TREND OF ACTIVE WEATHER
WITH THE POTENTIAL FOR A FEW CELLS PRODUCING HAIL OR A TORNADO WILL
CONTINUE THROUGH THE REST OF THE EARLY MORNING HOURS. THE BULK OF
STRONGER STORMS WILL SHIFT NORTHEAST AFTER SUNRISE AS SHORT WAVE
VORTMAX DOES SO AS WELL.
MOISTURE LEVELS REMAIN VERY HIGH ACROSS THE CENTRAL GULF COAST THIS
MORNING WITH THE 00Z SOUNDING FROM YESTERDAY AFTERNOON HAVING A
PRECIP WATER VALUE OF AROUND 1.7 INCHES WHICH IS RIGHT AT THE
CLIMATOLOGY MAX PER SPC SOUNDING INFO. BROAD LONG WAVE TROUGH IS
ALREADY IN PLACE OVER THE WESTERN HALF OF THE COUNTRY. AN EMBEDDED
WAVE WILL DIG AND SWING NEGATIVE OVER THE CENTRAL PLAINS TODAY. DOWN
AT THE SURFACE A LOW ON THE LEESIDE OF THE ROCKIES WILL BE RACING
NORTHEAST ACROSS THE CENTRAL MISSISSIPPI VALLEY. SURFACE PRESSURES
IN THE CWA WILL BE SLOWLY FALLING DURING THE DAY WITH A MINIMUM OF
APPROACHING 1000MB BY NOON BASED ON RUC OUTPUT. TIGHTENING OF THE
PRESSURE GRADIENT WILL INCREASE SURFACE WINDS INTO THE 15 TO 25
MPH RANGE. THIS SHOULD DO 2 THINGS...TRANSPORT OFFSHORE 70+DEGREE
DEWPOINTS FURTHER INLAND AS WELL AS INCREASE LOW LEVEL WIND SHEAR
SUBSTANTIALLY. HELICITY LIKELY TO FALL SOME AS WIND DIRECTION
BECOMES MORE CLOSELY ORIENTED TO THE MEAN FLOW OR MORE SOUTH TO
SOUTH WEST RATHER THAN CURRENT SOUTHEAST DIRECTION. PRESUMING THAT
SFC TEMPS DO REACH MID/UPPER 70S WHILE THESE DEWPOINTS
RISE...BUOYANCY AND INSTABILITY WILL SHOOT UP DURING THE DAY. BOTH
GFS AND NAM BUFR SOUNDINGS STILL SHOW SB AND PARCEL CAPE VALUES
WELL OVER 2000 J/KG AND MU CAPE UP TO 1500 J/KG ALL OVER THE CWA.
SPEED SHEAR LOOKING TO BE 40 TO 50 KNOTS IN THE BOUNDARY LAYER
WHICH IS PLENTY STRONG TO SUSTAIN SUPERCELLS. THUS THE POTENTIAL
FOR SEVERE WEATHER WILL DEFINITELY BE THERE TODAY. ALL MODES OF
SEVERE WEATHER ARE POSSIBLE. STILL OF CONCERN IS IF SFC TEMPS DONT
WARM ENOUGH... WILL JUST HAVE THE DYNAMICS. TOO STRONG OF A WARM
NOSE IN THE LOWER LEVELS COULD CAP THINGS AS WELL REGARDLESS...THE
POTENTIAL IS DEFINITELY THERE AND WARRANTS THE SLIGHT RISK AT THE
LEAST FOR THE ENTIRE CWA.
LONG TERM... RESIDUAL SURFACE BOUNDARY WILL BE THE FOCUS FOR
CONVECTION ON THURSDAY. AMPLE MOISTURE STILL LEFT IN THE AREA SHOULD
HAVE NO PROBLEM DEVELOPING INTO SHOWERS WITH POSSIBLY A FEW
THUNDERSTORMS. MUCH WEAKER WINDS IN THE COLUMN WILL LIMIT
ORGANIZATION OF STORMS BUT WONT BE SHORT OF INSTABILITY.
COVERAGE SHOULD STILL BE 50 TO 70 PERCENT FOR THE MOST PART.
CHRISTMAS DAY SHOULD BEGIN THE DOWNWARD TREND OF POPS AS UPPER LEVEL
RIDGE CENTERED OVER THE WESTERN ATLANTIC BUILDS BACK WESTWARD ACROSS
THE CWA. DESPITE THIS DECREASE IN COVERAGE...STILL PROBABLY LOOKING
AT 20 TO 30 PERCENT RAIN CHANCE. NO CHANCE IN THE TEMP FORECAST AND
EXPECTING NEAR RECORD MAX TEMPS AND RECORD HIGH LOWS. SADLY...THERE
IS A ZERO PERCENT CHANCE FOR A WHITE CHRISTMAS.
POPS TO FALL EVEN MORE DOWN INTO THE SLIGHT CHANCE CATEGORY THIS
WEEKEND AS THE RIDGE SHIFTS THE SHEAR ZONE FURTHER NORTH AND WEST.
GFS AND ECMWF BOTH CLOSE OFF A LOW IN THE DESERT SOUTHWEST AND
TRACKS EAST BEFORE SWINGING NE OVER THE CENTRAL PLAINS ENDING THE
WEEKEND. THIS WOULD BRING A LINE OF SHOWERS AND STORMS MOVING THRU
SOME TIME BETWEEN SUNDAY NIGHT AND MONDAY NIGHT DEPENDING ON MODEL
TIMING. NUDGED THE POPS TO THE SLOWER SOLUTION AS THE FASTER GFS IS
CLOSER TO AN OUTLIER SIDE OF THINGS.
MEFFER
AVIATION... SEVERE WEATHER CAME IN A LITTLE EARLIER TODAY THAN
EXPECTED. WILL KEEP THAT THREAT GOING THROUGH THE DAY BUT EXPECT A
REPRIEVE FOR SEVERAL HOURS AFTER DAYLIGHT TODAY. ANOTHER ROUND WILL
BE POSSIBLE THIS AFTERNOON BUT WILL HAVE TO SEE HOW THIS SHAPES UP.
CEILINGS WILL REMAIN FROM OVC020 TO OVC030 TODAY AND TONIGHT. RAIN
WILL ALSO CEASE FOR A WHILE TODAY AND WILL SHOW THIS IN THE 12Z TAF
PACKAGE.
WILL TAKE ANOTHER LOOK AT WX IN TAF SET LATER THIS MORNING.
MARINE... AS UPPER SYSTEM SWINGS THROUGH THE MIDDLE MISSISSIPPI
RIVER VALLEY TODAY...PRESSURE GRADIENT WILL TIGHTEN AND SMALL CRAFT
ADVISORIES AND EXERCISE CAUTION HEADLINES HAVE BEEN ISSUED AHEAD OF
THE SYSTEM. THIS SHOULD BE SOMEWHAT SHORT LIVED AS WINDS SUBSIDE
TONIGHT. NEXT PERIOD OF HEADLINES WILL BE EXERCISE CAUTION HEADLINES
OVER THE WEEKEND AS ONSHORE FLOW AGAIN STRENGTHENS.
DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING CONVECTIVE TRENDS.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 78 64 77 68 / 90 30 60 40
BTR 79 65 79 70 / 80 30 50 30
ASD 75 67 76 68 / 90 40 70 30
MSY 78 69 76 69 / 80 40 70 30
GPT 73 68 74 68 / 90 50 70 30
PQL 74 69 74 68 / 80 60 70 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ536-538-
550-552-555-557-570-572-575-577.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ538-550-
552-555-557-570-572-575-577.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
406 AM CST WED DEC 23 2015
.SHORT TERM... ACTIVE CONDITIONS ONGOING ACROSS THE FORECAST AREA
THIS MORNING. LOCAL VAD WIND PROFILE SHOWS THAT LOW LEVEL WINDS HAVE
INCREASES SUBSTANTIALLY OVER THE LAST FEW HOURS WITH SE FLOW OF 30
KNOTS AT THE LOWEST OBS OF 1KFT AND VEERING TO SW WHILE INCREASING
TO 50KTS IN THE MID LEVELS. THIS IS THE PRIMARY REASON FOR THE
RECENT RAMP UP OF STRONG/SEVERE THUNDERSTORMS EARLY THIS MORNING.
HAVE RECEIVED 1 REPORT OF HAIL AND SEVERAL CELLS HAVE BROAD
ROTATION...INDICATIVE OF INCREASING SRH. THIS IS ALL HAPPENING
DESPITE BEING WITHIN A MARINE LAYER. THE TREND OF ACTIVE WEATHER
WITH THE POTENTIAL FOR A FEW CELLS PRODUCING HAIL OR A TORNADO WILL
CONTINUE THROUGH THE REST OF THE EARLY MORNING HOURS. THE BULK OF
STRONGER STORMS WILL SHIFT NORTHEAST AFTER SUNRISE AS SHORT WAVE
VORTMAX DOES SO AS WELL.
MOISTURE LEVELS REMAIN VERY HIGH ACROSS THE CENTRAL GULF COAST THIS
MORNING WITH THE 00Z SOUNDING FROM YESTERDAY AFTERNOON HAVING A
PRECIP WATER VALUE OF AROUND 1.7 INCHES WHICH IS RIGHT AT THE
CLIMATOLOGY MAX PER SPC SOUNDING INFO. BROAD LONG WAVE TROUGH IS
ALREADY IN PLACE OVER THE WESTERN HALF OF THE COUNTRY. AN EMBEDDED
WAVE WILL DIG AND SWING NEGATIVE OVER THE CENTRAL PLAINS TODAY. DOWN
AT THE SURFACE A LOW ON THE LEESIDE OF THE ROCKIES WILL BE RACING
NORTHEAST ACROSS THE CENTRAL MISSISSIPPI VALLEY. SURFACE PRESSURES
IN THE CWA WILL BE SLOWLY FALLING DURING THE DAY WITH A MINIMUM OF
APPROACHING 1000MB BY NOON BASED ON RUC OUTPUT . TIGHTENING OF THE
PRESSURE GRADIENT WILL INCREASE SURFACE WINDS INTO THE 15 TO 25 MPH
RANGE. THIS SHOULD DO 2 THINGS...TRANSPORT OFFSHORE 70+DEGREE
DEWPOINTS FURTHER INLAND AS WELL AS INCREASE LOW LEVEL WIND SHEAR
SUBSTANTIALLY. HELICITY LIKELY TO FALL SOME AS WIND DIRECTION
BECOMES MORE CLOSELY ORIENTED TO THE MEAN FLOW OR MORE SOUTH TO
SOUTH WEST RATHER THAN CURRENT SOUTHEAST DIRECTION. PRESUMING THAT
SFC TEMPS DO REACH MID/UPPER 70S WHILE THESE DEWPOINTS
RISE...BUOYANCY AND INSTABILITY WILL SHOOT UP DURING THE DAY. BOTH
GFS AND NAM BUFR SOUNDINGS STILL SHOW SB AND PARCEL CAPE VALUES WELL
OVER 2000 J/KG AND MU CAPE UP TO 1500 J/KG ALL OVER THE CWA. SPEED
SHEAR LOOKING TO BE 40 TO 50 KNOTS IN THE BOUNDARY LAYER WHICH IS
PLENTY STRONG TO SUSTAIN SUPERCELLS. THUS THE POTENTIAL FOR SEVERE
WEATHER WILL DEFINITELY BE THERE TODAY. ALL MODES OF SEVERE WEATHER
ARE POSSIBLE. STILL OF CONCERN IS IF SFC TEMPS DONT WARM ENOUGH...
WILL JUST HAVE THE DYNAMICS. TOO STRONG OF A WARM NOSE IN THE LOWER
LEVELS COULD CAP THINGS AS WELL REGARDLESS...THE POTENTIAL IS
DEFINITELY THERE AND WARRANTS THE SLIGHT RISK AT THE LEAST FOR THE
ENTIRE CWA.
.LONG TERM... RESIDUAL SURFACE BOUNDARY WILL BE THE FOCUS FOR
CONVECTION ON THURSDAY. AMPLE MOISTURE STILL LEFT IN THE AREA SHOULD
HAVE NO PROBLEM DEVELOPING INTO SHOWERS WITH POSSIBLY A FEW
THUNDERSTORMS. MUCH WEAKER WINDS IN THE COLUMN WILL LIMIT
ORGANIZATION OF STORMS BUT WONT BE SHORT OF INSTABILITY.
COVERAGE SHOULD STILL BE 50 TO 70 PERCENT FOR THE MOST PART.
CHRISTMAS DAY SHOULD BEGIN THE DOWNWARD TREND OF POPS AS UPPER LEVEL
RIDGE CENTERED OVER THE WESTERN ATLANTIC BUILDS BACK WESTWARD ACROSS
THE CWA. DESPITE THIS DECREASE IN COVERAGE...STILL PROBABLY LOOKING
AT 20 TO 30 PERCENT RAIN CHANCE. NO CHANCE IN THE TEMP FORECAST AND
EXPECTING NEAR RECORD MAX TEMPS AND RECORD HIGH LOWS. SADLY...THERE
IS A ZERO PERCENT CHANCE FOR A WHITE CHRISTMAS.
POPS TO FALL EVEN MORE DOWN INTO THE SLIGHT CHANCE CATEGORY THIS
WEEKEND AS THE RIDGE SHIFTS THE SHEAR ZONE FURTHER NORTH AND WEST.
GFS AND ECMWF BOTH CLOSE OFF A LOW IN THE DESERT SOUTHWEST AND
TRACKS EAST BEFORE SWINGING NE OVER THE CENTRAL PLAINS ENDING THE
WEEKEND. THIS WOULD BRING A LINE OF SHOWERS AND STORMS MOVING THRU
SOME TIME BETWEEN SUNDAY NIGHT AND MONDAY NIGHT DEPENDING ON MODEL
TIMING. NUDGED THE POPS TO THE SLOWER SOLUTION AS THE FASTER GFS IS
CLOSER TO AN OUTLIER SIDE OF THINGS.
MEFFER
&&
.AVIATION... SEVERE WEATHER CAME IN A LITTLE EARLIER TODAY THAN
EXPECTED. WILL KEEP THAT THREAT GOING THROUGH THE DAY BUT EXPECT A
REPRIEVE FOR SEVERAL HOURS AFTER DAYLIGHT TODAY. ANOTHER ROUND WILL
BE POSSIBLE THIS AFTERNOON BUT WILL HAVE TO SEE HOW THIS SHAPES UP.
CEILINGS WILL REMAIN FROM OVC020 TO OVC030 TODAY AND TONIGHT. RAIN
WILL ALSO CEASE FOR A WHILE TODAY AND WILL SHOW THIS IN THE 12Z TAF
PACKAGE.
WILL TAKE ANOTHER LOOK AT WX IN TAF SET LATER THIS MORNING.
&&
.MARINE... AS UPPER SYSTEM SWINGS THROUGH THE MIDDLE MISSISSIPPI
RIVER VALLEY TODAY...PRESSURE GRADIENT WILL TIGHTEN AND SMALL CRAFT
ADVISORIES AND EXERCISE CAUTION HEADLINES HAVE BEEN ISSUED AHEAD OF
THE SYSTEM. THIS SHOULD BE SOMEWHAT SHORT LIVED AS WINDS SUBSIDE
TONIGHT. NEXT PERIOD OF HEADLINES WILL BE EXERCISE CAUTION HEADLINES
OVER THE WEEKEND AS ONSHORE FLOW AGAIN STRENGTHENS.
&&
DECISION SUPPORT...
DSS CODE....BLUE.
DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING CONVECTIVE TRENDS. MARGINAL TONIGHT...SLIGHT WED.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND
GREEN = NO WEATHER IMPACTS THAT REQUIRE ACTION
BLUE = LONG FUSED WATCH/WARNING/ADVISORY IN EFFECT OR HIGH
VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT
ORANGE = HIGH IMPACTS - SLIGHT TO MODERATE RISK SEVERE; NEARBY
TROPICAL EVENTS; HAZMAT OR OTHER LARGE EPISODES
RED = FULL ENGAGEMENT FOR MODERATE RISK SVR AND/OR DIRECT
TROPICAL THREATS; EVENTS OF NATIONAL SIGNIFICANCE
&&
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 78 64 77 68 / 90 30 60 40
BTR 79 65 79 70 / 80 30 50 30
ASD 75 67 76 68 / 90 40 70 30
MSY 78 69 76 69 / 80 40 70 30
GPT 73 68 74 68 / 90 50 70 30
PQL 74 69 74 68 / 80 60 70 30
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ536-538-
550-552-555-557-570-572-575-577.
MS...NONE.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR GMZ538-550-
552-555-557-570-572-575-577.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
330 PM EST WED DEC 23 2015
.SYNOPSIS...
LOW PRESSURE PASSES TO OUR WEST/NORTHWEST TONIGHT AND BRINGS
MODERATE TO HEAVY RAIN OUT AHEAD OF A WARM FRONT TONIGHT. THE
RAIN ENDS EARLY THURSDAY AND STRONG WARM AIR ADVECTION WILL SET
THE STAGE FOR SEVERAL RECORD HIGH TEMPERATURES TO BE
BROKEN...ESPECIALLY ACROSS SOUTHERN NEW HAMPSHIRE. A COLD FRONT
MOVES ACROSS THE AREA THURSDAY NIGHT AND ALTHOUGH TEMPERATURES
WILL RUN ABOUT 10 DEGREES COOLER ON CHRISTMAS DAY IT WILL STILL BE
QUITE PLEASANT WITH TEMPERATURES REMAINING WELL ABOVE NORMAL. OUR
NEXT STORM SYSTEM LOOKS TO ARRIVE LATE SATURDAY INTO SUNDAY AND
SHOULD BE MOSTLY IN THE FORM OF RAIN ONCE AGAIN. HOWEVER...COLDER
AIR WILL PUSH INTO THE REGION THE BEGINNING OF NEXT WEEK AND COULD
REMAIN IN PLACE LONG ENOUGH FOR SEVERAL LOCATIONS TO SEE THEIR
FIRST MEASURABLE SNOWFALL OF THE SEASON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
LOW LEVEL MOISTURE REMAINS TRAPPED BELOW A VERY SHARP AND SHALLOW
INVERSION EVIDENT ON THIS MORNINGS KGYX SOUNDING. SOME AREAS IN
NH HAVE MIXED OUT ON THE NORTHERN EDGE OF A STRATIFORM RAIN SHIELD
ALONG A NORTHWARD MOVING WARM FRONT. AS THE DEW POINT DEPRESSIONS
BECOME SMALLER HOWEVER FOG MAY AGAIN FORM IN AREAS IT HAS ALREADY
LIFTED.
THE DENSE FOG ADVISORY IN PLACE CONTINUES THROUGH 1 AM BUT
WILL LIKELY BE TRIMMED BACK AS THE RAIN ENTERS THE AREA AND
MECHANICALLY MIXES SOME OF THE MOISTURE OUT. HRRR AND OTHER
MESOSCALE MODELS INDICATE IN FACT THAT THE AREA OF DENSE FOG WILL
CONTINUE THROUGH AT LEAST MIDNIGHT BEFORE MOST OF IT DISSIPATES.
RAIN WILL BE HEAVY AT TIMES TONIGHT AND END MID MORNING
CHRISTMAS EVE. EXPECT DRIZZLE TONIGHT AND TOMORROW PRECEDING AND
BEHIND THE MAIN AREA OF PRECIPITATION. NOT EXPECTING THUNDERSTORMS
IN OUR AREA AS MID LEVEL INSTABILITY LOOKS TO STAY SOUTH. QPF
AMOUNTS WILL RANGE FROM A HALF INCH ACROSS THE NORTH TO ALMOST AN
INCH FROM THE FOOTHILLS SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MODELS ARE INDICATING A SIMILAR VERY SHARP INVERSION
TOMORROW AS TODAY...IE THE SAME LOW LEVEL LAYER OF MOISTURE WILL
ONLY MIX SO FAR EAST...DEPENDING ON WHERE THE WARM FRONT REACHES.
THERE IS LITTLE TO FORCE THE BOUNDARY UNTIL THE COLD FRONT
ARRIVES LATER CHRISTMAS EVE. THE NAM AND GEM ARE INDICATING A
VERY ABRUPT TEMPERATURE GRADIENT FROM WEST TO EAST ACROSS MAINE.
FOR THE MOST PART...NH WILL WARM INTO THE UPPER 50S TO EVEN UPPER
60S IN THE KEENE/MANCHESTER AREA AS THE WARM FRONT AT LEAST MAKES
IT THAT FAR. AS FOR MAINE...PORTIONS OF YORK COUNTY AND EVEN
CUMBERLAND COUNTY MIGHT REACH THE 60S...BUT FARTHER EAST WILL
LIKELY BE IN THE 50S AND EVEN UPPER 40S...AS SOME AREAS STRUGGLE
TO BREAK OUT OF FOG/STRATUS SIMILAR TO TODAY. ALL IN ALL IT WILL
BE A UNIQUE CHRISTMAS EVE FOR NEW ENGLAND...WITH RECORD-BREAKING
WARMTH LIKELY FROM NH SOUTHWEST.
RAIN...FOG...AND LOW LEVEL CLOUDS WILL BE SWEPT SOUTH AND EAST AS A
COLD FRONT MOVES THROUGH LATE CHRISTMAS EVE. SKIES SHOULD CLEAR OUT
FROM NORTH TO SOUTH EXCEPT FOR PERHAPS SOME CIRRUS.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
HIGHLIGHTS...
- ALTHOUGH COLD FRONT COMES THROUGH THURSDAY NIGHT...NEAR RECORD
TEMPERATURES WILL STILL BE POSSIBLE ON FRIDAY.
- FAST MOVING SYSTEM TO SPREAD MORE RAIN ACROSS MOST OF THE
REGION WITH POSSIBLE WINTRY MIX IN FAR NORTH.
- COOL HIGH PRESSURE WITH SEASONABLE TEMPS FOR THE BEGINNING OF
NEXT WEEK.
- POSSIBLE FIRST MEASURABLE SNOWFALL FOR MUCH OF THE AREA TUESDAY
INTO WEDNESDAY.
PATTERN SUMMARY: AS MENTIONED YESTERDAY...TELECONNECTION INDICES
WILL CONTINUE TO KEEP POLAR AIR CONFINED MOSTLY TO THE NORTH OF
THE REGION...WITH ONLY QUICK SHOTS OF SEASONABLE-LIKE WEATHER
FOLLOWED BY TEMPERATURES QUICKLY REBOUNDING TO ABOVE NORMAL
VALUES. THE HIGHLY AMPLIFIED RIDGE THAT IS OVER THE REGION TO
START THE PERIOD AND IS RESPONSIBLE FOR THE RECORD WARMTH FOR THE
NEXT TWO DAYS WILL FLATTEN OUT THIS WEEKEND. THIS WILL BRING US
BACK DOWN TO EARTH A BIT...WITH TEMPERATURES SATURDAY AND SUNDAY
LIKELY BEING ONLY SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR. AS
WE HEAD INTO EARLY NEXT WEEK...THE NORTHERN STREAM WILL SINK
SOUTHWARD SLIGHTLY...ENOUGH TO BRING SOME SEASONABLE TEMPERATURES
AS COLD CANADIAN HIGH PRESSURE SINKS OVER THE REGION. HOW STRONG
THIS HIGH PRESSURE IS WILL DETERMINE IF THE COLD AIR WILL HOLD ON
LONG ENOUGH TO ALLOW FOR DECENT OVERRUNNING AND PROVIDE MOST OF US
WITH OUR FIRST MEASURABLE SNOWFALL OF THE SEASON. STILL QUITE A
LOT OF UNCERTAINTY THOUGH AT THIS POINT IN THE FORECAST...SO SNOW
LOVERS WILL JUST HAVE TO KEEP THEIR FINGERS CROSSED AND HOPE THE
FORECAST UNFOLDS TO THEIR LIKING.
DAY BY DAY...
CHRISTMAS DAY: HIGH FORECAST CONFIDENCE
WEATHER IMPACTS: LOW
MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT FOR CHRISTMAS. COLD
FRONT PUSHES THROUGH THE AREA THURSDAY NIGHT INTO FRIDAY MORNING.
ALTHOUGH IT IS A COLD FRONT...THIS MAY ACTUALLY HELP SOME AREAS
WARM UP AS WARM AIR ALOFT MIXES DOWN TO THE SURFACE. TEMPERATURES
ARE LIKELY TO CLIMB TO NEAR RECORD VALUES ON FRIDAY AND DEPENDING
ON HOW FAR NORTH THE SURFACE WARM FRONT MAKES IT ON THURSDAY...MANY
PLACES MAY ACTUALLY TURN OUT WARMER ON CHRISTMAS DAY AS WE TAP
INTO THAT WARMER AIR ALOFT.
SATURDAY AND SUNDAY: MODERATE TO HIGH FORECAST CONFIDENCE
WEATHER IMPACTS: LOW
SHORT WAVE ARRIVES FROM THE SOUTHWEST SATURDAY NIGHT AND HIGH
PRESSURE OVERHEAD SHIFTS OFFSHORE. 12Z MODEL GUIDANCE HAS TRENDED
A BIT WARMER WITH TEMPERATURES ALOFT AND AT THE SURFACE WITH THIS
SYSTEM. FOR NOW IT APPEARS THAT THE BULK OF THE AREA WILL JUST SEE
LIQUID PRECIPITATION...BUT NORTHERN ZONES LOOK TO POTENTIALLY BE
BELOW FREEZING IN THE FOOTHILLS AND MOUNTAIN VALLEYS. THIS COULD
CAUSE A PERIOD OF POSSIBLE MIXED PRECIP OR FREEZING RAIN IN SOME
LOCATIONS. UPPER LEVEL FLOW WILL BE NEARLY ZONAL OVER THE
NORTHEAST CONUS BY THAT TIME...SO THIS SYSTEM SHOULD MOVE THROUGH
RATHER QUICKLY MAKING QPF LIMITED.
MONDAY - WEDNESDAY: LOW TO MODERATE FORECAST CONFIDENCE
WEATHER IMPACTS: POSSIBLY MODERATE WITH WINTRY PRECIPITATION
COLD CANADIAN HIGH PRESSURE DROPS DOWN OVER THE REGION AND
SHOULD MAKE FOR SEASONABLE HIGH TEMPERATURES. STRENGTH AND TIMING
OF THIS HIGH WILL DETERMINE HOW THE FORECAST UNFOLDS THEREAFTER.
EURO HAS STRONG HIGH PRESSURE MOVING RIGHT OVER NEW ENGLAND WHILE
THE GFS HAS A WEAKER SURFACE HIGH AND KEEPS THE HIGH IN CANADA
WITH SURFACE RIDGE EXTENDING OUT OVER NEW ENGLAND. THE EURO
SOLUTION WOULD KEEP COLD AIR IN PLACE MUCH LONGER AND DELAY THE
ONSET OF PRECIPITATION AS LOW PRESSURE APPROACHES FROM THE
SOUTHWEST. WARM AIR ADVECTION/OVERRUNNING ALOFT WILL BRING THE
POTENTIAL FOR PRECIPITATION TO START OFF AT LEAST AS ALL SNOW FOR
THE ENTIRE AREA. HOWEVER...WITH THE CURRENT TRACK OF THIS SYSTEM
FORECAST TO BE WEST OF THE REGION...AN EVENTUAL TRANSITION TO RAIN
WOULD LIKELY OCCUR ...BUT WILL CERTAINLY HAVE TO WATCH THE MODEL
TRENDS IN THE COMING DAYS AS THE 12Z EURO HAS NOW TRENDED EVEN
COLDER THAN THE 00Z RUN.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM...AREAS OF DENSE FOG WILL MAKE FOR LIFR CONDITIONS
FOR MUCH OF THE NIGHT. RAIN WILL SPREAD FROM THE SW AND IMPROVE
VISIBILITIES FOR A TIME. RAIN MAY BE HEAVY AT TIMES HOWEVER...AND
DRIZZLE IS LIKELY ALONG THE COAST AHEAD OF AND BEHIND THE MAIN
PRECIPITATION SHIELD. FOG WILL AGAIN BE AN ISSUE THURSDAY MORNING.
LONG TERM...VFR CONDITIONS EXPECTED UNTIL SATURDAY NIGHT INTO
SUNDAY...AS OUR NEXT SYSTEM COMES THROUGH THE AREA AND IFR OR
LOWER CONDITIONS ARE POSSIBLE THRU THE DAY ON SUNDAY. CANNOT RULE
OUT SOME MIXED PRECIP EITHER...ESPECIALLY FOR NORTHERN TERMINALS.
AT THIS TIME FORECAST CONFIDENCE IS LOW REGARDING SPECIFIC PRECIP
TYPES. HIGH PRESSURE AND VFR CONDITIONS WILL BUILD BACK INTO THE
REGION FOR MONDAY.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORY IS IN EFFECT BEGINNING TONIGHT
THROUGH TOMORROW FOR THE BAYS AND OUTER WATERS.
LONG TERM...HIGH PRESSURE AND OUR NEXT ARRIVAL OF COLD AIR WILL
BE MONDAY AND THIS MAY BRING A PERIOD OF SCA CONDITIONS WITH IT.
THIS WILL BE FOLLOWED BY A LOW PRESSURE LIKELY PASSING WEST OF
THE WATERS...WITH SOUTHWESTERLY WINDS WITH SCA CONDITIONS AHEAD
OF IT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...DENSE FOG ADVISORY UNTIL 1 AM EST THURSDAY FOR MEZ007>009-
012>014-018>028.
NH...DENSE FOG ADVISORY UNTIL 1 AM EST THURSDAY FOR NHZ010-014.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
THURSDAY FOR ANZ151-153.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 PM EST
THURSDAY FOR ANZ150-152-154.
&&
$$
SYNOPSIS...KISTNER
NEAR TERM...HANES
SHORT TERM...HANES
LONG TERM...KISTNER
AVIATION...HANES/KISTNER
MARINE...HANES/KISTNER
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
135 AM EST WED DEC 23 2015
.SYNOPSIS...
A STEADY FEED OF MOISTURE ON THE BACK SIDE OF HIGH PRESSURE OVER
THE WESTERN ATLANTIC WILL KEEP THE UNSEASONABLY WARM AND UNSETTLED
CONDITIONS ACROSS THE AREA THROUGH THURSDAY. A WEAK COLD FRONT
APPROACHES LATE THURSDAY...THEN STALLS ACROSS THE AREA THROUGH
THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
VRB LYRD CLDNS OVR THE FA THIS EVE. (SCT) -RA CONTG TO MOVE NE
ACRS MOSTLY NE NC ATTM. WIDESPREAD ST (CIGS 500-1500FT) MNLY ACRS
FM I 95 ON W...ALG W/ PATCHY FG. 00Z/23 RUC HAS AREA OF RA
BLOSSOMING FM SCNTRL VA S THROUGH WRN PORTION OF NC AFT
MDNGT...WHICH CONTS TO SPREAD TO THE N AND NE THROUGH THE REST OF
THE NGT. MEANWHILE...RA WILL RMN LIKELY INVOF THE CST. WILL NEED
TO MONITOR FG...ESP INLAND...THOUGH RIGHT NOW XPCG MOSTLY LO ST
OVR WIDESPREAD FG. LO TEMPS IN THE U50S TO ARND 60F.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/...
SAID S/W PROGGED TO TRACK NE ALONG THE SPINE OF THE MTS WED. THIS
SYSTM TAPS COPIOUS AMTS OF GOM MSTR AND DRIVES IT NE. MSTR OFF THE
ATLNTC GETS ENTRAINED INTO THE SYSTM AS WELL. APPEARS THE BULLSEYE
FOR THE HEAVIEST RAINFALL WILL BE ACROSS THE MTS. FOR AKQ FA...THIS
WUD MOST AFFECT THE VA PIEDMONT MAINLY WEST OF I95 WHERE BTWN 1 TO
1.5 INCHES WILL BE PSBL (HIGHEST OUT NR LKU-FVX). RAINFALL TDY WAS
ARND AN INCH. AFTR THE COORD CALL AND GIVEN THE QUICK MOVMNT OF THE
HEAVIEST AXIS OF RAINFALL WED...NO FLOOD PRODUCTS WILL BE ISSUED
WITH THIS PACKAGE. THE RUNOFF WILL LIKELY END UP IN THE RIVERS
RAISING LEVELS OVER THE NEXT FEW DAYS.
AS THE BEST OMEGA LIFTS NORTH WED AFTRN...PCPN BECOMES SOMEWHAT MORE
CONVECTIVE THAN STRATIFORM GIVEN THE UNUSUAL WARM AIRMASS. NOT
MUCH INSTABILITY PROGGED...BUT CAN NOT RULE OUT ELVATED THUNDER
DRNG THE AFTR AS WAVES OF PCPN TRAVERSE EAST DUE TO LINGERING
TROFINESS. DESPITE THE CLOUDS/PCPN...TMPS APPRCH RECORD LEVELS IN
SOME AREAS. HIGHS 70-75.
MAIN LOW LIFTS NORTH INTO SRN NEW ENGLAND WED NITE. COPIOUS AMTS OF
MSTR REMAIN ACROSS THE FA DUE TO WEAK DISTURBANCES MOVG NE. TSCTNS
LOADED WITH ENUF MSTR TO KEEP CHC/LIKELY POPS GOING. FOG WILL BECOME
AN ISSUE ONCE AGAIN. WARM AND RTHR HUMID WITH LOWS IN THE M-U60S.
MODELS SHOWING AKQ FA IN A WARM SECTOR SCENARIO FOR X-MAS EVE AHEAD
OF THE APPRCHG BNDRY TO THE NW. NOT MUCH SPRT FOR PCPN UNTIL THE
AFTRN WHERE SCT CONVECTION IS PSBL GIVEN THE AVAILABLE MSTR AND
ADVANCING BNDRY. HIGHS WILL ALL DEPEND ON HOW MUCH SUN DVLPS...BUT
ALL DATA SHOWING SUMMER LIKE READINGS WITH HIGHS 75-80. IT IS NOT A
QUESTION ON WHETHER WE SET NEW RECORD HIGH TMPS...BUT BY HOW MUCH???
WILL FEEL MORE LIKE LABOR DAY THAN X-MAS EVE.
CHC POPS THU NITE ALONG WITH MORE FOG PTNTL AS THE BNDRY WEAKENS BUT
LINGERS ACROSS THE AREA. WARM AND HUMID ONCE AGAIN WITH LOWS U50S
NORTH TO M60S SOUTH.
MODELS DIFFER FRI ON JUST WHERE THE BNDRY ENDS UP. CONSENSUS IS FOR
IT TO SAG SOUTH AS A BKDR COLD FRNT TO NE THE VA/NC BORDER. ENUF
MSTR TO KEEP CHC POPS IN FCST. NOT AS WARM...BUT STILL WELL ABV
NRML. WINDS TURN NORTH FOR A SHORT TIME ALLOWING SOMEWHAT COOLER
AIR TO FILTER SOUTH. HIGHS RANGE FROM THE M-U60S OVER THE ERN
SHORE...L- M70S ELSEWHERE. THESE VALUES FALLING JUST SHY OF THE
RECORD HIGHS FOR X-MAS DAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE LONG TERM PERIOD WILL FEATURE A CONTINUATION OF WARM TEMPS AND
CHANCES FOR SHOWERS. RIDGING OVER THE SOUTHEASTERN STATES WILL
PREVENT SIGNIFICANT AIR MASS CHANGES. A WEAK FRONTAL BOUNDARY WILL
BE OVER THE MID ATLANTIC STATES DURING THE LONG TERM PERIOD. THERE
IS GENERALLY A 30 PERCENT CHANCE FOR PCPN ALTHOUGH THESE SHOWERS
CHANCES DROP OFF SATURDAY NIGHT AND SUNDAY AND THEN INCREASE ONCE
AGAIN SUNDAY NIGHT THROUGH TUESDAY. PCPN IS NOT EXPECTED TO BE
WIDESPREAD.
HIGH TEMPERATURES WILL GENERALLY RUN IN THE 60S TO LWR 70S EXCEPT
EXCEPT UPR 50S TO 60S ON MONDAY. LOWS ARE FORECAST TO RANGE IN THE
UPR 40S TO 50S NORTH PORTIONS AND 50S TO NEAR 60 PORTIONS.
&&
.AVIATION /07Z WEDNESDAY THROUGH SUNDAY/...
CONDITIONS ARE NOW MAINLY IFR/LIFR ALL SITES IN A COMBINATION OF
REDUCED VSBYS THAT AVG 1-3SM AND LOW CLOUDS WITH CIGS THAT AVG
200-1000 FT. CHANCES FOR RAIN INCREASE THROUGH THE NEXT FEW HRS AS
WELL.
PERIODS OF SHOWERS WITH PSBL IFR WILL CONTINUE LATER
TODAY...THOUGH CONDITIONS SHOULD GRADUALLY IMPROVE BETWEEN 15-18Z. EXPECT
WIND GUST UP TO 20-25 KT ACRS SE VA/NE NC THIS AFTN...AND ALL
AREAS TONIGHT/THU MORNING. THIS STRENGTHENING PRESSURE GRADIENT
SHOULD ACT TO INHIBIT FOG DEVELOPMENT AND KEEP VSBYS UP TONIGHT/THU
MORNING BUT SOME LOWER CIGS WILL STILL BE POSSIBLE.
OUTLOOK...A WEAK FRONTAL BOUNDARY WILL BE IN THE VICINITY OF THE
MID ATLANTIC STATES BEGINNING FRIDAY. ASIDE FROM PCPN...PATCHY IFR
CONDITIONS WILL BE PSBL IN THE OUTLOOK PERIOD DURING THE PREDAWN
THROUGH MID MORNING HOURS FRI/SAT DUE TO LOW STRATUS AND FOG (BUT
SHOULD NOT BE AS WIDESPREAD AS WED MORNING).
&&
.MARINE...
SOUTH TO SOUTHWEST WINDS WILL PREVAIL OVER THE MARINE AREA
THROUGH EARLY FRIDAY. SEAS IN THE NORTHERN COASTAL WATERS HAVE
FALLEN BELOW 5 FT.
THE PRESSURE GRADIENT TIGHTENS LATE WEDNESDAY AS MESO SCALE LOW
PRESSURE DEVELOPS OVER WEST VIRGINIA AS DEPICTED BY THE NAM.
SOUTHERLY WINDS ARE FORECAST TO INCREASE AND PRODUCE SCA OVER THE
BAY...LOWER JAMES AND CURRITUCK SOUND STARTING AT 18Z. SCA ALSO
STARTS IN THE COASTAL WATERS AT 21Z AS SEAS ARE EXPECTED TO BUILD TO
5 TO 6 FT. CURRENT ADVISORY S OF PARRAMORE ISLAND WILL NEED TO BE
EXTENDED NORTH WHEN THE CURRENT ADVISORY EXPIRES.
WHILE THE WINDS OVER INLAND WATERS DIMINISH ALLOWING THE SCA TO END
AROUND 06Z THURSDAY...THE SCA IN THE COASTAL WATERS WILL CONTINUE AS
SEAS STAY 5 FT OR HIGHER THROUGH MUCH OF THURSDAY.
WINDS DIMINISH FRIDAY AS A WEAK FRONTAL BOUNDARY DROPS INTO THE
REGION. PRESSURE GRADIENT WILL BE WEAK ALONG THE BOUNDARY. CURRENT
INDICATIONS HAVE SEAS BUILDING EARLY NEXT WEEK DUE TO A PROLONGED
PERIOD OF ONSHORE WINDS.
&&
.CLIMATE...
CORRECTED
RECORD HIGH TEMPS FOR DEC 23RD:
RIC...73 IN 1990
ORF...77 IN 1990
SBY...71 IN 1990
ECG...76 IN 2013
RECORD HIGH TEMPS FOR DEC 24TH: RECORD HIGH MIN TEMPS FOR DEC 24TH:
RIC...71 IN 1988 RIC...49 IN 1979
ORF...75 IN 1891 ORF...59 IN 1891
SBY...70 IN 2014 SBY...50 IN 2014
ECG...75 IN 1990 ECG...58 IN 1956
RECORD HIGH TEMPS FOR DEC 25TH: RECORD HIGH MIN TEMPS FOR DEC 25TH:
RIC...74 IN 1955 RIC...58 IN 1964
ORF...75 IN 1964 ORF...59 IN 1964
SBY...73 IN 1932 SBY...60 IN 1964
ECG...75 IN 1955 ECG...56 IN 1964
ALL TIME HIGH TEMPS FOR DEC:
RIC...81 IN 1998
ORF...81 IN 2013
SBY...77 IN 2013
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 1 AM EST
THURSDAY FOR ANZ630>634-638.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 4 PM EST
THURSDAY FOR ANZ650-652-654-656-658.
&&
$$
SYNOPSIS...ALB/MPR
NEAR TERM...ALB
SHORT TERM...MPR
LONG TERM...LSA
AVIATION...LKB/DAP
MARINE...LSA
CLIMATE...AKQ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
619 PM EST THU DEC 24 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 405 PM EST THU DEC 24 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WEST INTO THE CNTRL CONUS RESULTING IN SW FLOW FROM THE
PLAINS INTO THE CNTRL PLAINS TO THE NRN LAKES. A SHRTWV FROM SE SD
INTO WRN IA SUPPORTED AN AREA OF SNOW OVER IA. OTHERWISE...DRY
CONDITIONS PREVAILED FROM NRN MN THROUGH UPPER MI. WINDS HAVE
DIMINISHED THIS AFTERNOON AS THE PRES GRADIENT WEAKENS IN ADVANCE OF
HIGH PRES BUILDING TOWARD THE AREA FROM THE NRN PLAINS. EVEN WITH 850
MB TEMPS NEAR -10C...ONLY A FEW FLURRIES OBSERVED FOR WEST FLOW LES
AREAS AS INVERSION HEIGHTS HAVE DROPPED TO AROUND 3K-4K FT.
TONIGHT...WRLY FLOW WITH LOW LEVEL CONV WILL FAVOR CONTINUED CHANCE
OF LIGHT SNOW SHOWERS FOR THE KEWEENAW. HOWEVER...WITH THE TOP OF
THE CLOUD LAYER NEAR -10C...ICE NUCLEI MAY BE LACKING RESULTING
POTENTIAL FOR SOME FZDZ. OTHERWISE...WINDS WILL CONTINUE TO DIMINISH
WITH GRADUAL CLEARING OVER THE WEST HALF LATE TONIGHT. TEMPS SHOULD
DROP INTO THE UPPER TEENS TO LOWER 20S.
FRIDAY...THE RIDGE WILL BUILD INTO THE WRN LAKES WITH PARTLY TO
MOSTLY SUNNY SKIES. THE SUNSHINE WILL HELP PUSH TEMPS INTO THE 30 TO
35 RANGE...COLDEST OVER THE WEST WITH THE MOST SNOW COVER.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM EST THU DEC 24 2015
THE PHASING OF A COUPLE PIECES OF UPPER LEVEL ENERGY WILL RESULT IN
SOME LIGHT TO POTENTIALLY MODERATE SNOW AT TIMES OVER MUCH OR ALL OF
THE CWA LATE FRI NIGHT UNTO EARLY SAT NIGHT BEFORE TRANSITIONING TO
LES. MODELS CONTINUE TO TREND NW WITH THE HEAVIEST QPF/SNOW...SO
WILL CONTINUE SHOWING THAT TREND IN THE FORECAST. ALSO...MODELS ARE
NOT IN COMPLETE AGREEMENT ON PRECIP AMOUNTS...SO THERE REMAINS SOME
UNCERTAINTY THERE AS WELL. AT THIS POINT...EXPECT GREATEST SNOWFALL
FROM NCENTRAL UPPER MI...WHERE WINDS WILL TURN OUT OF THE NE ON SAT
PROVIDING UPSLOPE FORCING...TO THE KEWEENAW AND WRN UPPER MI. HAVE 3-
5 INCHES IN THESE AREAS...WITH LOWER AMOUNTS TO THE S AND E. BLOWING
SNOW WILL BE ON THE INCREASE NEAR LAKE SUPERIOR ON SAT AS WIND GUSTS
INCREASE TO 25-30MPH AND BECOME NORTHERLY.
THE WINDS WILL CARRY MUCH COLDER AIR AS AN UPPER TROUGH DROPS
THROUGH SAT NIGHT INTO SUN MORNING. 850MB TEMPS WILL DROP FROM
AROUND -8C AT 00Z SUN TO BETWEEN -15C AND -20C LATE SUN INTO SUN
NIGHT. WINDS WILL BE OUT OF THE NW UNTIL AFTER 00Z MON WHEN WINDS
WILL TURN N-NNE...THEN OUT OF THE E MON MORNING AS A HIGH PASSES N
OF THE AREA. MOST OF THIS TIME WILL SEE INVERSION HEIGHT AROUND
4KFT...WITH GOOD SNOW RATIOS...BUT A SHORTWAVE MAY MOVE THROUGH SUN
EVENING THAT WOULD BRING A HEAVIER BURST OF SNOW AS THE WINDS TURN
MORE N-NNE. OVERALL GOOD CONFIDENCE OF LIGHT TO OCCASIONALLY
MODERATE LES AND PATCHY BLOW SNOW IN NW WIND SNOWBELTS...BECOMING N-
NNE SNOW BELTS LATE SUN INTO MON MORNING. THIS SHOULD RESULT IN
SEVERAL INCHES OF SNOW DURING THIS PERIOD. WILL INCREASE
QPF/SNOWFALL AMOUNTS AND POPS.
FOR NEXT WEEK...LOTS OF UNCERTAINTY AS THE UPPER LOW THAT WILL FORM
OVER THE U.S./MEXICO BORDER LOOKS TO BREAK DOWN AND SHIFT THROUGH
THE REGION TUE INTO TUE NIGHT. THERE ARE A LOT OF VARIABLES WITH
SNOWFALL FORECAST FOR THAT TIME...BUT THE OVERALL APPEARANCE IS THAT
A MAJOR PATTERN CHANGE MAY OCCUR. MODELS SHOW THE LONGWAVE UPPER
TROUGH THAT HAS BEEN OVER THE WRN CONUS SHIFTING TO THE ERN
CONUS...WITH COLDER AIR AND MORE ACTIVE WEATHER THE GENERAL THEME.
STAY TUNED TO LATER FORECASTS FOR DETAILS NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 619 PM EST THU DEC 24 2015
WINDS HAVE ALREADY DIMINISHED AT SAW AND IWD AND WILL CONTINUE TO DO
SO OVER THE NEXT COUPLE OF HOURS AT CMX AS SURFACE RIDGING BUILDS
INTO THE GREAT LAKES AND PRESSURE GRADIENT RELAXES. ENOUGH LOW
LEVEL MOISTURE WILL LINGER TO SUPPORT MARGINAL VFR CIGS AT IWD AND
MVFR CIGS AT CMX AND SAW THROUGH MUCH OF TONIGHT. CONDITIONS AT IWD
AND SAW WILL IMPROVE TO VFR TOWARD FRI MORNING WHILE CMX REMAINS
MVFR TIL MIDDAY FRI WITH UPSLOPE WESTERLY FLOW CONTINUING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EST THU DEC 24 2015
AS HIGH PRESSURE BUILDS TOWARD THE REGION THIS
EVENING...WINDS WILL DROP BELOW GALE FORCE. HIGH PRESSURE BUILDS
ACROSS THE LAKE FOR CHRISTMAS DAY BEFORE ANOTHER LOW MOVES ACROSS
THE SOUTHERN GREAT LAKES SATURDAY NIGHT. STRONGER HIGH PRESSURE IS
EXPECTED TO BUILD ACROSS THE UPPER GREAT LAKES SUNDAY INTO MONDAY.
AFTER TONIGHT...WINDS SHOULD STAY BELOW 30KT ACROSS LAKE SUPERIOR
THROUGH MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EST THIS EVENING FOR LSZ265>267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ243>251-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...MZ
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
442 PM EST WED DEC 23 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 440 PM EST WED DEC 23 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD TROUGH OVER THE WRN
CONUS AND A RIDGE FROM THE WRN ATLANTIC INTO NEW ENGLAND RESULTING
IN SSW FLOW FROM THE SRN PLAINS INTO THE WRN GREAT LAKES. A VIGOROUS
SHORTWAVE TROUGH OVER CNTRL IA WAS LIFTING QUICKLY TO THE NORTHEAST.
AT THE SFC...A 983 MB LOW WAS LOCATED OVER ERN IA WITH A WARM FRONT
TO THE EAST THROUGH SRN LAKE MI. AN AREA OF RAIN OVER UPPER MI AND
NE WI SUPPORTED BY 295K-300K ISENTROPIC LIFT AHEAD OF THE SHRTWV AND
WARM FRONT WAS LIFTING TO THE NNE. TO THE WEST...SNOW OVER NE MN
INTO NW WI WAS ASSOCIATED WITH A BAND OF 850-700 MB
FGEN/DEFORMATION.
TONIGHT...AFTER THE FIRST BATCH OF PCPN MOVES OUT OF THE CNTRL AND
EAST...THE AREA OF FGEN AND 700-300 MB QVECTOR CONV AHEAD OF THE
SHRTWV WILL BRING MORE PCPN THROUGH UPPER MICHIGAN. AS THE TROUGH
AND COLD FRONT NEAR IWD AND 00Z MOVES TO THE NEAR MQT-IMT BY 06Z AND
ERY AROUND 09Z THE RAIN WILL CHANGE TO SNOW. HOWEVER...THE HEAVIEST
PCPN...AS RAIN...IS EXPECTED BEFORE THE COLD AIR MOVES IN. THE
EXCEPTION WILL BE OVER THE FAR WEST (NEAR IWD) WHERE 1 TO 4 INCHES
WILL BE POSSIBLE AND A WINTER WX WAS ISSUED. OTHERWISE...ANY
ACUMULATIONS WILL AMOUNT TO AN INCH OR LESS.
THE OTHER MAIN CONCERN IS THE POTENTIAL FOR STRONG WINDS OVERNIGHT.
AS THE FRONT LIFTS THROUGH A VERY STRNOG ISALLOBARIC COMPONENT WITH
12 MB/3HR PRES RISE WILL BRING VERY GUSTY WINDS TO ESPECIALLY THE
ERN CWA BTWN 06Z-12 WHERE A WIND ADVY IS IN EFFECT. WRLY WINDS WILL
ALSO BE VERY GUSTY OVER THE KEWEENAW WHERE 925 MB WINDS TO 50 KT ARE
FCST.
THURSDAY...A THE STORNG PRES GRADIENT WILL CONTINUE TO BRING GUSTY
WINDS TO UPPER MICHIGAN DURING THE MORNING. THE ADVY WAS MAINTAINED
TIL 21Z OVER THE KEWEENAW GIVEN THE FAVORABLE EXPOSURE TO THE STRONG
WEST WINDS THROUGH MID AFTERNOON. 850 MB TEMPS TO AROUND -8C WILL
ALSO SUPPORT ADDITIONAL LAKE ENHANCED SNOW INTO THE KEWEENAW AS THE
DEEPER WRAP-AROUND MOISTURE LINGERS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 PM EST WED DEC 23 2015
SURFACE LOW WILL CONTINUE TO LIFT PRETTY QUICKLY NORTHEASTWARD INTO
QUEBEC THURSDAY EVENING WITH SURFACE RIDGING BUILDING ACROSS THE
GREAT LAKES FOR CHRISTMAS EVE NIGHT AND THROUGH THE DAY ON
CHRISTMAS. WINDS WILL DIMINISH THURSDAY EVENING WITH A PRETTY
TRANQUIL CHRISTMAS DAY EXPECTED ACROSS THE UP. WITH SOME SUNSHINE
TEMPERATURES WILL CLIMB INTO THE LOWER AND MIDDLE 30S...ABOUT 5 TO
10 DEGREES ABOVE AVERAGE.
ATTENTION WILL THEN TURN TO NORTHERN STREAM UPPER TROUGHING MOVING
EASTWARD ALONG THE CANADIAN BORDER TOWARDS THE UPPER GREAT LAKES
ALONG WITH SHORT WAVE ENERGY LIFTING NORTHEASTWARD FROM THE
DEVELOPING CLOSED LOW OVER THE FOUR CORNERS REGION. MODELS CONTINUE
SHOW A SIGNIFICANT AMOUNT OF UNCERTAINTY STILL WITH THE
PRECIPITATION. GFS AND ECMWF SEEM TO BE MOST CONSISTENT WITH SHOWING
BEST WARM ADVECTION AND FRONTOGENESIS ACROSS THE AREA ON SATURDAY
YIELDING A MARGINAL ADVISORY SNOWFALL FOR THE CENTRAL AND WESTERN UP
WITH SNOW AMOUNTS IN THE 2-4 INCH RANGE WITH LOCALLY HIGHER AMOUNTS
IN THE UPSLOPE AREAS FAVORED BY NORTHEAST WINDS. NAM AND GEM TO A
LESSER EXTENT STILL MORE SHEARED OUT AND KEEP STRONGEST FORCING
SOUTH AND EAST OF THE AREA.
HIGH PRESSURE WITH SEASONABLE TEMPERATURES WILL BUILD BACK ACROSS
THE AREA FOR THE SUNDAY INTO MONDAY TIME PERIOD. 85H TEMPERATURES
WILL BE MARGINAL FOR LIGHT NORTH TO NORTHWEST WIND LAKE EFFECT
SATURDAY NIGHT INTO SUNDAY BUT ANY ACCUMULATIONS WILL BE LIGHT.
MAIN UPPER LOW WILL BEGIN TO EJECT OUT OF THE SOUTHWEST EARLY NEXT
WEEK WITH VARYING SOLUTIONS ON THE TRACK OF THE SURFACE LOW. ECMWF
MOST WOUND UP WITH A TRACK MORE FAVORABLE FOR ACCUMULATING SNOW FOR
MUCH OF THE AREA. GFS IS FARTHER SOUTH AND EAST SUGGESTING ANY
SIGNIFICANT PRECIPITATION STAYS SOUTH AND EAST OF THE AREA. DETAILS
WILL BE RESOLVED OVER THE COMING DAYS WITH A MODEL BLEND THE BEST
COURSE OF ACTION AT THIS TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 100 PM EST WED DEC 23 2015
VLIFR CIGS ARE EXPECTED TODAY INTO THIS EVENING AS VERY
MOIST LOW LEVEL AIR REMAINS OVER THE REGION WITH SRLY FLOW AND LIGHT
PCPN. VSBY AT OR BELOW MINS ARE EXPECTED TO CLIMB WHEN HEAVIER RAIN
DEVELOPS ESPECIALLY LATE THIS AFTERNOON AND EVENING. LLWS IS
EXPECTED AT SAW TONIGHT WITH A STRONG SW LOW LEVEL JET ABOVE THE
MAINLY DECOUPLED SFC WINDS. RAIN WILL CHANGE OVER TO SNOW FROM WEST
TO EAST LATE THIS EVENING AND OVERNIGHT. GUSTY WEST WINDS WILL
DEVELOP LATE TONIGHT AT IWD/CMX AND THU MORNING AT SAW AS THE
STRONG LOW LIFTS TO THE NORTH OF THE REGION.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 PM EST WED DEC 23 2015
SIGNIFICANT WIND EVENT WILL OCCUR TONIGHT INTO THURSDAY ACROSS THE
WATERS AND THE WIND WILL INCREASE RAPIDLY LATE TONIGHT. A TIGHT
PRESSURE GRADIENT LATE TONIGHT COMBINED WITH A STRONG PRESSURE RISE
OF 12 MB IN THREE HOURS OVER LAKE MICHIGAN WILL CAUSE STORM FORCE
WINDS ACROSS EASTERN LAKE SUPERIOR AND NORTHERN LAKE MICHIGAN LATE
TONIGHT INTO THURSDAY AND A HIGH END GALE ACROSS THE WEST HALF OF
LAKE SUPERIOR. ONCE THIS EVENT ENDS THURSDAY AFTERNOON...WINDS LOOK
TO STAY BELOW 30 KNOTS THROUGH THE REST OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY FROM 3 AM EST /2 AM CST/ TO 1 PM EST /NOON CST/
THURSDAY FOR MIZ007-012>014-085.
WIND ADVISORY FROM 5 AM TO 4 PM EST THURSDAY FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 4 AM CST THURSDAY FOR MIZ009.
LAKE SUPERIOR...
STORM WARNING FROM 5 AM TO 7 PM EST THURSDAY FOR LSZ265>267.
GALE WARNING FROM 3 AM EST /2 AM CST/ TO 7 PM EST /6 PM CST/
THURSDAY FOR LSZ162-240>245-263-264.
GALE WARNING FROM 5 AM TO 7 PM EST THURSDAY FOR LSZ246>251.
LAKE MICHIGAN...
STORM WARNING FROM 1 AM TO NOON EST THURSDAY FOR LMZ221-248-250.
GALE WARNING FROM NOON TO 5 PM EST THURSDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...MZ
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1254 PM EST WED DEC 23 2015
.AVIATION...
WARM FRONT CURRENTLY LIFTING NORTH THROUGH LOWER MICHIGAN RESULTING
IN CONTINUED LIFR/IFR CONDITIONS INTO THE AFTERNOON HOURS. ELEVATED
FRONT SEEN ON RADAR PRODUCING SHOWERS BUT ACTUAL SURFACE FRONT
REMAINS QUITE DIFFUSE. SHOULD SEE SOME IMPROVEMENTS LATER THIS
AFTERNOON AS WE GET DEEPER INTO THE WARM SECTOR WITH CIGS LIFTING TO
MVFR. THIS WILL LAST A FEW HOURS BEFORE PRE FRONTAL SHOWERS AND
THUNDERSTORMS TRACK EAST THROUGH THE AREA. THE COLD FRONT WILL
FOLLOW AROUND 09Z SWITCHING WINDS FROM SOUTHERLY TO SOUTHWEST. WIND
SPEEDS WILL INCREASE DRAMATICALLY WITH GUSTS POSSIBLY EXCEEDING 35
KNOTS FOR ALL TAF SITES...AND POSSIBLY OVER 45 KNOTS FOR MBS AND
FNT. ON THURSDAY WINDS WILL GRADUALLY DECREASE WHILE DRIER AIR ALOFT
PRODUCES CLEARING SKIES.
FOR DTW...IFR/LIFR WILL LINGER A FEW MORE HOURS BEFORE FINALLY
LIFTING TO MVFR AS WE GET DEEPER INTO THE WARM SECTOR. MAY BE A
COUPLE BRIEF PERIODS OF DRIZZLE BUT SHOULD NOT PERSIST LONG AT ALL.
SHOWERS AND POSSIBLY THUNDERSTORMS WILL APPROACH THE TERMINAL AROUND
00-03Z THIS EVENING AHEAD OF A COLD FRONT. MAIN THREAT WILL BE
STRONG WINDS ALOFT MIXING DOWN TO THE SURFACE. LONGER DURATION WIND
EVENT WILL OCCUR AFTER THE COLD FRONTAL PASSAGE AROUND 09Z WHERE
GUSTS WILL REACH 30 TO 35 KNOTS.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING BELOW 5000 FEET THROUGH TONIGHT.
* LOW FOR CIGS/VSBY BELOW 200FT AND/OR 1/2SM THIS AFTERNOON.
* MEDIUM THAT THUNDERSTORMS WILL IMPACT THE TERMINAL BETWEEN 00-03Z.
* MODERATE TO HIGH FOR GUSTS EXCEEDING CROSSWIND THRESHOLD AFTER 09Z.
&&
.PREV DISCUSSION...ISSUED 1147 AM EST WED DEC 23 2015
UPDATE...
FORECAST RATIONAL REMAINS LARGELY UNCHANGED AFTER WATCHING RADAR
AND SATELLITE TRENDS THIS MORNING AND PERUSING INITIAL 12Z MODEL
GUIDANCE. LEAD BATCH OF SHOWERS WITH A FEW RUMBLES OF THUNDER WILL
CONTINUE TO LIFT NORTH THROUGH THE FORECAST AREA ON NOSE OF WARM
FRONTAL BOUNDARY. THIS FRONT WILL GRADUALLY BECOME BETTER DEFINED
AS IT CROSSES NORTH THROUGH THE AREA THIS AFTERNOON. TEMPERATURES
WILL CLIMB THROUGH THE 50S DURING THAT TIME FRAME...AND REACH 60
DEGREE IN SOME LOCATIONS BY LATE AFTERNOON.
WHILE SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL BECOME
INCREASINGLY WIDESPREAD DURING THE COURSE OF THE AFTERNOON...THE
MAIN FOCUS WILL BE A LARGE AREA OF VIGOROUS CONVECTION CURRENTLY
EXTENDING FROM PARTS OF ILLINOIS SOUTH INTO SOUTHEAST MISSOURI
AND ARKANSAS WHERE THE THUNDERSTORM ACTIVITY IS PARTICULARLY
STRONG IN ADVANCE OF PRE-FRONTAL TROUGH PIVOTING EAST NORTHEAST
AROUND DEEPENING LOW PRESSURE OVER EASTERN KANSAS. 12Z MODEL
RUNS...SUPPORTED BY HI RES HRRR AND RAP RUNS THIS MORNING SUGGEST
SOME SEMBLANCE OF THESE LINE OF STORMS WILL ARC INTO SOUTHEAST
LOWER MICHIGAN BETWEEN 5 AND 8 PM...BRINGING THE POTENTIAL OF
DAMAGING WINDS...AND PERHAPS AN ISOLATED TORNADO GIVEN THE STRONG
BULK WIND SHEAR PRESENT IN THE LOWEST PART OF THE ATMOSPHERE.
INSTABILITY...OR LACK THEREOF...REMAIN THE MAIN NEGATING FACTOR
AS CAPE VALUE ARE FORECAST TO REMAIN BELOW 500 J/KG AS THIS LEAD
ACTIVITY MOVES INTO THE AREA WITH HIGHER VALUES THEN CREEPING
NORTH DURING THE REST OF THE EVENING IN ADVANCE OF COLD FRONT TO
AT LEAST MAINTAIN THE CHANCE OF STORMS. VERY STRONG WINDS ARE
STILL EXPECTED ALONG/BEHIND THE COLD FRONT OVERNIGHT AND A WIND
ADVISORY WILL MOST LIKELY BE REQUIRED FOR THE AREA...AT LEAST FOR
A SHORT TIME OVERNIGHT INTO PARTS OF THURSDAY MORNING. FINAL
DECISIONS ON THIS WILL BE IRONED OUT THIS AFTERNOON.
PREV DISCUSSION...ISSUED 337 AM EST WED DEC 23 2015
DISCUSSION...
LATEST WATER VAPOR IMAGERY SHOWS DEEPENING LONGWAVE TROUGH OVER
CENTRAL NORTH AMERICA...WITH THE FLOW OVER THE GULF COAST STATES
BACKING TO THE SOUTH. HOWEVER...THE LEAD MOISTURE ORIGINATING FROM
TENNESSEE/KENTUCKY IS EXPECTED TO SLIDE NORTHEAST INTO THE EASTERN
GREAT LAKES...PER 850 MB THETA-E FIELDS...WITH THE CORRESPONDING
NEGATIVE LI`S MOSTLY EAST...AND HAVE BACKED OFF ON THUNDERSTORM AND
POP MENTION THIS MORNING. STILL ENOUGH LOW LEVEL MOISTURE
ADVECTION/ISENTROPIC ASCENT AND EVENTUAL SATURATION TO TRIGGER
LIGHT RAIN/DRIZZLE AS THE DAY WEARS ON.
OUR FOCUS THIS EVENING/TONIGHT IS ON THE MOISTURE OVER EASTERN TEXAS
WHICH WILL BE ACCELERATING OFF TO THE NORTHEAST...AS EXPLOSIVE
CYCLOGENESIS (20 MB IN 24 HRS) EXPECTED TO TAKE PLACE.
DEEPENING SURFACE LOW TRACKS THROUGH THE WESTERN GREAT LAKES THIS
EVENING...AND NORTHEAST INTO JAMES BAY THURSDAY MORNING...AS
PHASING/CONSOLIDATION OF UPPER LEVEL PV (DAKOTAS/SOUTHERN PLAINS)
TAKES PLACE...DIRECTED AND SPED UP BY THE VERY STRONG UPPER LEVEL
WAVE/PV SLICING THROUGH THE PACIFIC NORTHWEST...HELPING TO FUEL
THE AGGRESSIVE DEVELOPMENT.
THE MOISTURE/CONVECTIVE AXIS LOOKS TO BE MOVING THROUGH SOUTHEAST
MICHIGAN AROUND MIDNIGHT...AND THE 00Z NAM IS INDICATING
CONSIDERABLE MORE INSTABILITY AS SURFACE BASED CAPES REACH TO AROUND
750 J/KG...WHILE THE GFS REMAINS MORE SUBDUED...STRUGGLING TO REACH
300 J/KG. INTERESTING...THE SURFACE DEW PT FORECAST FOR BOTH MODELS
ARE VERY CLOSE...SNEAKING INTO THE UPPER 50S. EVEN TAKING A BLEND OF
THE TWO SOLUTIONS..THE EXCEPTIONAL WIND FIELDS (50-55 KNOTS AT 925
MB/60+ KNOTS AT 850 MB) SUPPORT A DAMAGING WIND THREAT WITH ANY
VIGOROUS CONVECTION...WITH SEEMS LIKE A DECENT
POSSIBILITY/SCATTERED THUNDERSTORM COVERAGE...AS MID LEVEL LAPSE
(700-500 MB) LOOK TO BE AROUND 7 C/KM TO POSSIBLY AS HIGH AS 8
C/KM (SEE 00Z EURO). PLANNING ON INCLUDING DAMAGING WIND POTENTIAL
IN THE ZONES...AS LATEST SPC DAY 1 HAS TRENDED SOUTHEAST MICHIGAN
INTO THE MARGINAL TO SLIGHT CHANCE CATEGORIES NOW. STILL CAN`T
RULE OUT ISOLATED TORNADOES WITH EXTREME 0-1 KM BULK SHEAR (UP
NEAR 50 KNOTS) AND MUCH OF THE CAPE DENSITY DOWN LOW. VARIOUS
HIRES MODELS ARE GIVING MIXED SIGNALS...AND ARE INDICATING FASTER
ARRIVAL TIME OF CONVECTION DURING THE EARLY EVENING HOURS...WITH
OTHERS INDICATING MORE OF A MUTED RESPONSE THROUGH THE ENTIRE
NIGHT.
925 MB TEMPS INCREASING BETWEEN 13 TO 14 C TOWARD MIDNIGHT STILL
SUGGESTING LOWER 60S WILL BE NO PROBLEM...AND LOOKS LIKE WE WILL
DOUBLE DIP AND SET TWO DAYS OF RECORD HIGHS.
HIGH TEMPERATURE RECORDS FOR DECEMBER 23RD:
DTW 56 (1893)
FNT 55 (1982)
MBS 53 (1982)
DECEMBER 24TH
DTW 61 (1889)
FNT 56 (1982)
MBS 55 (1932)
PW VALUES AROUND 1.25 INCHES...850 MB DEW PTS 10+ C...CONTINUE TO
SUGGEST POTENTIAL RAINFALL AROUND HALF INCH...WITH
LOCALIZED/ISOLATED 1+ INCH TOTALS NOT OUT OF THE QUESTION.
THE ACTUAL COLD FRONTAL PASSAGE LOOKS TO BE TOWARD 12Z
THURSDAY...AND GOOD CHANCE LOCATIONS NORTH OF I-69 WILL SEE GUSTS OF
45+ MPH WITH SUBSIDENCE/COLD ADVECTION POP...AS 850 MB TEMPS CRASH
TO NEAR ZERO. ELECTED TO NOT ISSUE WIND ADVISORY AT THIS TIME...AS
FOCUS IS MORE ON SEVERE/DAMAGING WIND POTENTIAL...AND WE ARE TALKING
VERY LATE SECOND PERIOD.
UPPER LEVEL WEST-SOUTHWEST CONFLUENT FLOW THURSDAY-FRIDAY LOOKS TO
KEEP SOUTHEAST MICHIGAN MAINLY DRY...WITH TEMPERATURES STILL SOLIDLY
ABOVE NORMAL AND ABOVE FREEZING THE MAJORITY OF THE TIME.
PER 00Z EURO... IT LOOKS LIKE THE WEEKEND WILL FEATURE SPLIT UPPER
LEVEL FLOW..WITH CUTOFF UPPER LEVEL LOW OVER THE FOUR CORNERS
REGION...AND PROGRESSIVE NORTHERN STREAM SHORTWAVE TROUGH SLIDING
THROUGH THE GREAT LAKES ON SUNDAY. A WAVE OF LOW PRESSURE LOOKS TO
BE SCOOTING OFF TO THE NORTHEAST OUT OF THE SOUTHERN PLAINS/MIDWEST
ON SATURDAY...WITH THERMAL PROFILES SUGGESTING ALL RAIN FOR
SOUTHEAST MICHIGAN.
MARINE...
SURFACE LOW PRESSURE WILL RAPIDLY DEEPEN THIS EVENING TO 980 MB
WHILE TRACKING NORTHWARD ACROSS WISCONSIN AND LAKE SUPERIOR. A TIGHT
PRESSURE GRADIENT IS FORECASTED TO DEVELOP ALONG THE SOUTHEASTERN
FLANK OF THE LOW PRESSURE CENTER OVER LAKE MICHIGAN AND PORTIONS OF
NORTHERN LOWER MICHIGAN SIGNALING A HIGH POTENTIAL FOR STRONG WINDS.
TIMING OF THE STRONG COLD FRONT THROUGH THE STATE IS AFTER 09Z.
SOUTHEASTERLY WINDS WILL APPROACH GALE FORCE TODAY OVER THE OPEN
WATERS OF LAKE HURON. THE MOST IMPACTFUL PART OF THE LOW PRESSURE
SYSTEM WILL BE THE WESTERLY WINDS FORECASTED TO DEVELOP IN THE WAKE
OF THE COLD FRONT LATE TONIGHT AND THURSDAY. WHILE WESTERLY WINDS
ARE EXPECTED TO BE STRONG OVER ALL OF LAKE HURON...THE NORTH HALF OF
LAKE HURON WILL BE IN THE BETTER POSITION TO WITNESS WIND GUSTS TO
45 KNOT GALES. GALE WARNINGS HAVE BEEN ISSUED FOR ALL OF LAKE HURON.
RAPID MOVEMENT OF THE SURFACE LOW TO JAMES BAY...WITH A FAST
EVOLVING UPPER LEVEL PATTERN...SUPPORTS A RELATIVELY QUICK
DIMINISHING WIND TREND ALREADY THURSDAY AFTERNOON AND EVENING. WIND
GUSTS ARE EXPECTED TO DROP BELOW 20 KNOTS BY 06Z FRIDAY.
HYDROLOGY...
A LOW PRESSURE SYSTEM WILL STRENGTHEN TODAY WHILE TRACKING NORTHEAST
TO LAKE SUPERIOR. THE LOW PRESSURE SYSTEM WILL LIFT A STRONG WARM
FRONT THROUGH SOUTHERN MICHIGAN...BRINGING VERY WARM AND MOIST AIR
TO THE REGION. THERE WILL BE MULTIPLE OPPORTUNITIES FOR RAINFALL
TODAY...WITH THE POTENTIAL FOR BRIEF HEAVY RAINFALL IN POTENTIAL
THUNDERSTORM DEVELOPMENT WAITING UNTIL THE LATE AFTERNOON OR DURING
THE LATE EVENING HOURS. MOST LOCATIONS WILL SEE AROUND 0.5 INCHES OF
RAIN BY THURSDAY MORNING WITH ISOLATED TOTALS OF AROUND 1.0 INCH.
LITTLE CONCERN FOR FLOODING EXISTS.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING FROM 3 AM TO NOON EST THURSDAY FOR LHZ421-422-441-462.
GALE WARNING FROM 4 AM TO 10 AM EST THURSDAY FOR LHZ442-443-463-464.
GALE WARNING FROM 7 PM THIS EVENING TO 3 PM EST THURSDAY FOR
LHZ361>363.
LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST THURSDAY
FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST THURSDAY
FOR LEZ444.
&&
$$
AVIATION.....DRK
UPDATE.......DG
DISCUSSION...SF
MARINE.......CB
HYDROLOGY....CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1147 AM EST WED DEC 23 2015
.UPDATE...
FORECAST RATIONAL REMAINS LARGELY UNCHANGED AFTER WATCHING RADAR
AND SATELLITE TRENDS THIS MORNING AND PERUSING INITIAL 12Z MODEL
GUIDANCE. LEAD BATCH OF SHOWERS WITH A FEW RUMBLES OF THUNDER WILL
CONTINUE TO LIFT NORTH THROUGH THE FORECAST AREA ON NOSE OF WARM
FRONTAL BOUNDARY. THIS FRONT WILL GRADUALLY BECOME BETTER DEFINED
AS IT CROSSES NORTH THROUGH THE AREA THIS AFTERNOON. TEMPERATURES
WILL CLIMB THROUGH THE 50S DURING THAT TIME FRAME...AND REACH 60
DEGREE IN SOME LOCATIONS BY LATE AFTERNOON.
WHILE SCATTERED SHOWERS AND A FEW THUNDERSTORMS WILL BECOME
INCREASINGLY WIDESPREAD DURING THE COURSE OF THE AFTERNOON...THE
MAIN FOCUS WILL BE A LARGE AREA OF VIGOROUS CONVECTION CURRENTLY
EXTENDING FROM PARTS OF ILLINOIS SOUTH INTO SOUTHEAST MISSOURI
AND ARKANSAS WHERE THE THUNDERSTORM ACTIVITY IS PARTICULARLY
STRONG IN ADVANCE OF PRE-FRONTAL TROUGH PIVOTING EAST NORTHEAST
AROUND DEEPENING LOW PRESSURE OVER EASTERN KANSAS. 12Z MODEL
RUNS...SUPPORTED BY HI RES HRRR AND RAP RUNS THIS MORNING SUGGEST
SOME SEMBLANCE OF THESE LINE OF STORMS WILL ARC INTO SOUTHEAST
LOWER MICHIGAN BETWEEN 5 AND 8 PM...BRINGING THE POTENTIAL OF
DAMAGING WINDS...AND PERHAPS AN ISOLATED TORNADO GIVEN THE STRONG
BULK WIND SHEAR PRESENT IN THE LOWEST PART OF THE ATMOSPHERE.
INSTABILITY...OR LACK THEREOF...REMAIN THE MAIN NEGATING FACTOR
AS CAPE VALUE ARE FORECAST TO REMAIN BELOW 500 J/KG AS THIS LEAD
ACTIVITY MOVES INTO THE AREA WITH HIGHER VALUES THEN CREEPING
NORTH DURING THE REST OF THE EVENING IN ADVANCE OF COLD FRONT TO
AT LEAST MAINTAIN THE CHANCE OF STORMS. VERY STRONG WINDS ARE
STILL EXPECTED ALONG/BEHIND THE COLD FRONT OVERNIGHT AND A WIND
ADVISORY WILL MOST LIKELY BE REQUIRED FOR THE AREA...AT LEAST FOR
A SHORT TIME OVERNIGHT INTO PARTS OF THURSDAY MORNING. FINAL
DECISIONS ON THIS WILL BE IRONED OUT THIS AFTERNOON.
&&
.AVIATION...ISSUED 652 AM EST WED DEC 23 2015
AGGRESSIVE IFR/LIFR CIG/VSBY TREND DEVELOPING OVER LOWER MICHIGAN
THIS MORNING AS IMPRESSIVE LOW LEVEL THETA E SURGE IS NOW UNDERWAY.
THE FIRST POTENTIAL FOR SHOWER ACTIVITY...LIKELY A BRIEF ONE...WILL
BE AT/AROUND 14Z AS SURFACE WARM FRONT LIFTS NORTHWARD. SOME
IMPROVEMENT IN CIGS IS STILL EXPECTED DURING THE AFTERNOON WITH A
BETTER FOOTHOLD INTO THE WARM SECTOR. THE POTENTIAL FOR
THUNDERSTORMS...WITH SOME POSSIBLY REACHING SEVERE
LIMITS...APPEARS TO BE PRIMARILY CENTERED AT/AROUND THE 01-03Z
TIME WINDOW. THE OTHER ITEM OF CONCERN THIS TAF PERIOD IS THE
STRONG POST COLD FRONTAL WEST WINDS THAT WILL INCREASE AFTER 09Z
TONIGHT. THE STRONGEST WIND POTENTIAL WILL OCCUR NORTH OF
INTERSTATE 69 WHERE WINDGUSTS OF 45 KNOTS WILL BE LIKELY.
FOR DTW...IFR/LIFR CIGS ARE SET TO DEVELOP OVER THE TERMINAL
SHORTLY AFTER THE START OF THE TAF PERIOD. POTENTIAL EXISTS FOR
FAIRLY INNOCUOUS SHOWER ACTIVITY BETWEEN 14-16Z. THERE IS LOW
CONFIDENCE IN VSBYS DROPPING TO 1/4SM WITH THE WARM FRONT THIS
MORNING. FAVORABLE TIME WINDOW FOR SHOWERS AND SCATTERED TSTORMS
IS BETWEEN 01-03Z THIS EVENING. STRONG POST FRONTAL WEST WINDS ARE
EXPECTED TO GUST TO 30 KNOTS AT DTW AFTER 09Z TONIGHT.
//DTW THRESHOLD PROBABILITIES...
* HIGH FOR CEILING BELOW 5000 FEET THROUGH TONIGHT.
* LOW FOR CIGS/VSBY BELOW 200FT AND/OR 1/2SM THIS MORNING.
* MODERATE TO HIGH FOR GUSTS EXCEEDING CROSSWIND THRESHOLD AFTER 09Z.
&&
.PREV DISCUSSION...ISSUED 337 AM EST WED DEC 23 2015
DISCUSSION...
LATEST WATER VAPOR IMAGERY SHOWS DEEPENING LONGWAVE TROUGH OVER
CENTRAL NORTH AMERICA...WITH THE FLOW OVER THE GULF COAST STATES
BACKING TO THE SOUTH. HOWEVER...THE LEAD MOISTURE ORIGINATING FROM
TENNESSEE/KENTUCKY IS EXPECTED TO SLIDE NORTHEAST INTO THE EASTERN
GREAT LAKES...PER 850 MB THETA-E FIELDS...WITH THE CORRESPONDING
NEGATIVE LI`S MOSTLY EAST...AND HAVE BACKED OFF ON THUNDERSTORM AND
POP MENTION THIS MORNING. STILL ENOUGH LOW LEVEL MOISTURE
ADVECTION/ISENTROPIC ASCENT AND EVENTUAL SATURATION TO TRIGGER
LIGHT RAIN/DRIZZLE AS THE DAY WEARS ON.
OUR FOCUS THIS EVENING/TONIGHT IS ON THE MOISTURE OVER EASTERN TEXAS
WHICH WILL BE ACCELERATING OFF TO THE NORTHEAST...AS EXPLOSIVE
CYCLOGENESIS (20 MB IN 24 HRS) EXPECTED TO TAKE PLACE.
DEEPENING SURFACE LOW TRACKS THROUGH THE WESTERN GREAT LAKES THIS
EVENING...AND NORTHEAST INTO JAMES BAY THURSDAY MORNING...AS
PHASING/CONSOLIDATION OF UPPER LEVEL PV (DAKOTAS/SOUTHERN PLAINS)
TAKES PLACE...DIRECTED AND SPED UP BY THE VERY STRONG UPPER LEVEL
WAVE/PV SLICING THROUGH THE PACIFIC NORTHWEST...HELPING TO FUEL
THE AGGRESSIVE DEVELOPMENT.
THE MOISTURE/CONVECTIVE AXIS LOOKS TO BE MOVING THROUGH SOUTHEAST
MICHIGAN AROUND MIDNIGHT...AND THE 00Z NAM IS INDICATING
CONSIDERABLE MORE INSTABILITY AS SURFACE BASED CAPES REACH TO AROUND
750 J/KG...WHILE THE GFS REMAINS MORE SUBDUED...STRUGGLING TO REACH
300 J/KG. INTERESTING...THE SURFACE DEW PT FORECAST FOR BOTH MODELS
ARE VERY CLOSE...SNEAKING INTO THE UPPER 50S. EVEN TAKING A BLEND OF
THE TWO SOLUTIONS..THE EXCEPTIONAL WIND FIELDS (50-55 KNOTS AT 925
MB/60+ KNOTS AT 850 MB) SUPPORT A DAMAGING WIND THREAT WITH ANY
VIGOROUS CONVECTION...WITH SEEMS LIKE A DECENT
POSSIBILITY/SCATTERED THUNDERSTORM COVERAGE...AS MID LEVEL LAPSE
(700-500 MB) LOOK TO BE AROUND 7 C/KM TO POSSIBLY AS HIGH AS 8
C/KM (SEE 00Z EURO). PLANNING ON INCLUDING DAMAGING WIND POTENTIAL
IN THE ZONES...AS LATEST SPC DAY 1 HAS TRENDED SOUTHEAST MICHIGAN
INTO THE MARGINAL TO SLIGHT CHANCE CATEGORIES NOW. STILL CAN`T
RULE OUT ISOLATED TORNADOES WITH EXTREME 0-1 KM BULK SHEAR (UP
NEAR 50 KNOTS) AND MUCH OF THE CAPE DENSITY DOWN LOW. VARIOUS
HIRES MODELS ARE GIVING MIXED SIGNALS...AND ARE INDICATING FASTER
ARRIVAL TIME OF CONVECTION DURING THE EARLY EVENING HOURS...WITH
OTHERS INDICATING MORE OF A MUTED RESPONSE THROUGH THE ENTIRE
NIGHT.
925 MB TEMPS INCREASING BETWEEN 13 TO 14 C TOWARD MIDNIGHT STILL
SUGGESTING LOWER 60S WILL BE NO PROBLEM...AND LOOKS LIKE WE WILL
DOUBLE DIP AND SET TWO DAYS OF RECORD HIGHS.
HIGH TEMPERATURE RECORDS FOR DECEMBER 23RD:
DTW 56 (1893)
FNT 55 (1982)
MBS 53 (1982)
DECEMBER 24TH
DTW 61 (1889)
FNT 56 (1982)
MBS 55 (1932)
PW VALUES AROUND 1.25 INCHES...850 MB DEW PTS 10+ C...CONTINUE TO
SUGGEST POTENTIAL RAINFALL AROUND HALF INCH...WITH
LOCALIZED/ISOLATED 1+ INCH TOTALS NOT OUT OF THE QUESTION.
THE ACTUAL COLD FRONTAL PASSAGE LOOKS TO BE TOWARD 12Z
THURSDAY...AND GOOD CHANCE LOCATIONS NORTH OF I-69 WILL SEE GUSTS OF
45+ MPH WITH SUBSIDENCE/COLD ADVECTION POP...AS 850 MB TEMPS CRASH
TO NEAR ZERO. ELECTED TO NOT ISSUE WIND ADVISORY AT THIS TIME...AS
FOCUS IS MORE ON SEVERE/DAMAGING WIND POTENTIAL...AND WE ARE TALKING
VERY LATE SECOND PERIOD.
UPPER LEVEL WEST-SOUTHWEST CONFLUENT FLOW THURSDAY-FRIDAY LOOKS TO
KEEP SOUTHEAST MICHIGAN MAINLY DRY...WITH TEMPERATURES STILL SOLIDLY
ABOVE NORMAL AND ABOVE FREEZING THE MAJORITY OF THE TIME.
PER 00Z EURO... IT LOOKS LIKE THE WEEKEND WILL FEATURE SPLIT UPPER
LEVEL FLOW..WITH CUTOFF UPPER LEVEL LOW OVER THE FOUR CORNERS
REGION...AND PROGRESSIVE NORTHERN STREAM SHORTWAVE TROUGH SLIDING
THROUGH THE GREAT LAKES ON SUNDAY. A WAVE OF LOW PRESSURE LOOKS TO
BE SCOOTING OFF TO THE NORTHEAST OUT OF THE SOUTHERN PLAINS/MIDWEST
ON SATURDAY...WITH THERMAL PROFILES SUGGESTING ALL RAIN FOR
SOUTHEAST MICHIGAN.
MARINE...
SURFACE LOW PRESSURE WILL RAPIDLY DEEPEN THIS EVENING TO 980 MB
WHILE TRACKING NORTHWARD ACROSS WISCONSIN AND LAKE SUPERIOR. A TIGHT
PRESSURE GRADIENT IS FORECASTED TO DEVELOP ALONG THE SOUTHEASTERN
FLANK OF THE LOW PRESSURE CENTER OVER LAKE MICHIGAN AND PORTIONS OF
NORTHERN LOWER MICHIGAN SIGNALING A HIGH POTENTIAL FOR STRONG WINDS.
TIMING OF THE STRONG COLD FRONT THROUGH THE STATE IS AFTER 09Z.
SOUTHEASTERLY WINDS WILL APPROACH GALE FORCE TODAY OVER THE OPEN
WATERS OF LAKE HURON. THE MOST IMPACTFUL PART OF THE LOW PRESSURE
SYSTEM WILL BE THE WESTERLY WINDS FORECASTED TO DEVELOP IN THE WAKE
OF THE COLD FRONT LATE TONIGHT AND THURSDAY. WHILE WESTERLY WINDS
ARE EXPECTED TO BE STRONG OVER ALL OF LAKE HURON...THE NORTH HALF OF
LAKE HURON WILL BE IN THE BETTER POSITION TO WITNESS WIND GUSTS TO
45 KNOT GALES. GALE WARNINGS HAVE BEEN ISSUED FOR ALL OF LAKE HURON.
RAPID MOVEMENT OF THE SURFACE LOW TO JAMES BAY...WITH A FAST
EVOLVING UPPER LEVEL PATTERN...SUPPORTS A RELATIVELY QUICK
DIMINISHING WIND TREND ALREADY THURSDAY AFTERNOON AND EVENING. WIND
GUSTS ARE EXPECTED TO DROP BELOW 20 KNOTS BY 06Z FRIDAY.
HYDROLOGY...
A LOW PRESSURE SYSTEM WILL STRENGTHEN TODAY WHILE TRACKING NORTHEAST
TO LAKE SUPERIOR. THE LOW PRESSURE SYSTEM WILL LIFT A STRONG WARM
FRONT THROUGH SOUTHERN MICHIGAN...BRINGING VERY WARM AND MOIST AIR
TO THE REGION. THERE WILL BE MULTIPLE OPPORTUNITIES FOR RAINFALL
TODAY...WITH THE POTENTIAL FOR BRIEF HEAVY RAINFALL IN POTENTIAL
THUNDERSTORM DEVELOPMENT WAITING UNTIL THE LATE AFTERNOON OR DURING
THE LATE EVENING HOURS. MOST LOCATIONS WILL SEE AROUND 0.5 INCHES OF
RAIN BY THURSDAY MORNING WITH ISOLATED TOTALS OF AROUND 1.0 INCH.
LITTLE CONCERN FOR FLOODING EXISTS.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING FROM 3 AM TO NOON EST THURSDAY FOR LHZ421-422-441-462.
GALE WARNING FROM 4 AM TO 10 AM EST THURSDAY FOR LHZ442-443-463-464.
GALE WARNING FROM 7 PM THIS EVENING TO 3 PM EST THURSDAY FOR
LHZ361>363.
LAKE ST CLAIR...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST THURSDAY
FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST THURSDAY
FOR LEZ444.
&&
$$
UPDATE.......DG
AVIATION.....CB
DISCUSSION...SF
MARINE.......CB
HYDROLOGY....CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1145 AM CST WED DEC 23 2015
.UPDATE...
ISSUED AT 915 AM CST WED DEC 23 2015
UPDATED WEATHER TYPES FOR TODAY THROUGH 00Z. HAVE HAD REPORTS THIS
MORNING OF SLEET/RAIN MIX IN SOUTHERN WASHBURN COUNTY AND A
SNOW/RAIN MIX IN HAYWARD IN THE PAST FEW HOURS. STILL THINKING THE
COLUMN WILL COOL AND TREND TOWARD BETTER ICE CRYSTAL SEEDING
THROUGH THIS MORNING AS PRECIP RATES INCREASE...RESULTING IN
BETTER SNOW COVERAGE. HAVE INCLUDED A BIT MORE SLEET AND A
BROADER AREA OF RA/SN THROUGH THIS MORNING AND INTO THE AFTERNOON.
ALSO INCREASED COVERAGE OF DZ/FZDZ THROUGHOUT THE DAY IN AREAS NOT
EXPERIENCING THE HEAVIER PRECIPITATION. ALSO THREW IN A MENTION OF
FOG WHICH HAS BEEN OBSERVED AT SEVERAL SITES THIS MORNING.
UPDATE ISSUED AT 630 AM CST WED DEC 23 2015
MINOR UPDATE TO POPS AND WEATHER...IN GENERAL FORECAST REMAINS ON
TRACK WITH A LIGHT WINTRY MIX QUICKLY CHANGING TO MAINLY SNOW
WEST OF HIGHWAY 63 IN NW WISCONSIN AND MORE RAIN THAN SNOW EAST OF
HIGHWAY 63.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
RAIN/SNOW WILL QUICKLY SPREAD ACROSS NORTHWEST WISCONSIN AND PARTS
OF NORTHEAST MINNESOTA TODAY RESULTING IN A QUICK FEW INCHES OF SNOW
FOR PARTS OF THE REGION. WHERE THE RAIN/SNOW LINE WILL BE IS STILL
DIFFICULT TO DETERMINE EVEN AT THIS SHORT TIME RANGE...BUT
CONFIDENCE HAS INCREASED IN COVERAGE OF PRECIPITATION /TRENDING
FARTHER WEST/ INTENSITY /HIGHER AMOUNTS/ AND RANGE OF PRECIP TYPES
EXPECTED /MAINLY JUST RAIN OR SNOW WITH LITTLE MIX/. RAIN/SNOW ENDS
QUICKLY FROM WEST TO EAST LATE TONIGHT WITH LINGERING FLURRIES
POSSIBLE INTO EARLY THURSDAY. WHEN IT IS ALL DONE THERE WILL LIKELY
BE A SWATH OF 2 TO 4 INCHES OF SNOW ACROSS A PORTION OF NORTHWEST
WISCONSIN...WITH OTHER LOCATIONS EXPERIENCE MAINLY RAIN ENDING AS
LIGHT SNOW.
ON THE SYNOPTIC SCALE A MID-LEVEL TROUGH AXIS WILL SWING NORTHEAST
FROM THE LOWER MISSOURI RIVER VALLEY INTO THE UPPER GREAT LAKES
TODAY. WHILE A POTENT LOW PRESSURE SYSTEM OVER THE RED RIVER VALLEY
MOVES NORTH INTO NORTHWEST ONTARIO IT WILL WEAKEN WHILE A STRONG AND
BROADER LOW PRESSURE DEVELOPS IN NORTHERN MISSOURI LATE THIS MORNING
MOVING NORTH-NORTHEAST INTO THE U.P. THIS EVENING. IN ADDITION TO
THE MID-LEVEL TROUGH A 120-130 KT JET STREAK DEVELOPS OVER THE
NORTHLAND LATE THIS MORNING RESULTING IN UPPER LEVEL DIVERGENCE
ACROSS NORTHERN WISCONSIN THIS AFTERNOON. FINALLY...WARM AIR
ADVECTION ONGOING AT LOW LEVELS HAS RAISED TEMPS TO THE MID 30S
ACROSS NORTHERN WISCONSIN WITH MODEL SOUNDINGS INDICATING A FAIRLY
WARM LAYER ALOFT...AS VERIFIED BY THE MPX 00Z SOUNDING. IN GENERAL
THE TREND IN GUIDANCE HAS BEEN A WESTWARD SHIFT AND STRONGER LARGE-
SCALE LIFT AS THE MID-LEVEL TROUGH RAPIDLY APPROACHES AND HEIGHTS
FALL THIS AFTERNOON. THE HRRR ACCENTUATES THIS TREND WITH RUNS THIS
MORNING COMING IN EVEN FURTHER WEST THAN MOST OF THE 00Z MODEL SUITE.
WHILE TEMPS ARE IN THE MID 30S ACROSS NORTHWEST WISCONSIN DEW POINTS
ARE STILL NEAR TO BELOW FREEZING...AND ONCE LOW LEVELS SATURATE
THINK THERE WILL BE A QUICK TRANSITION FROM LIGHT RAIN/DRIZZLE TO
SNOW ACROSS PARTS OF NORTHWEST WISCONSIN. THE RAIN/SNOW TRANSITION
LINE IS VERY CHALLENGING FOR TODAYS FORECAST WHICH RESULTS IN A
FAIRLY HIGH BUST POTENTIAL...BUT WITH THE LIKELIHOOD OF INTENSE
PRECIP AND TEMPS AT THE SFC AND THROUGH THE COLUMN COLD ENOUGH TO
SUPPORT SNOW BELIEVE THERE WILL BE A SWATH OF 2 TO 5 INCHES LATE
THIS MORNING INTO THE EARLY AFTERNOON. THUS...DECIDED TO GO WITH A
WINTER WX ADVISORY. THE RAIN/SNOW LINE LOOKS TO BE IN WESTERN
ASHLAND/SAWYER COUNTIES...AND DESPITE MOST OF THOSE COUNTIES
PROBABLY RECEIVING MAINLY RAIN TODAY THE FACT THAT /1/ THERE IS
STILL SOME UNCERTAINTY IN THIS FORECAST AND /2/ THE MOST POPULATED
CITIES IN EACH COUNTY ARE EXPECTED TO RECEIVE SNOW IS WHY WE DECIDED
TO ISSUE THE WINTER WX ADVISORY FOR THOSE COUNTIES. ON THE WEST
THERE WILL BE A SHARP CUT-OFF FOR WHERE THE ACCUMULATING SNOW
FALLS...WITH THIS LINE PROBABLY CLOSE TO THE TWIN PORTS. FOR NOW
HAVE 1 TO 3 INCHES OF SNOW FOR THE TWIN PORTS...THERE IS THE
POTENTIAL LITTLE IF ANY PRECIP OCCURS BUT DO NOT THINK THERE IS
POTENTIAL FOR MORE THAN THREE INCHES...SO DID NOT INCLUDE DULUTH IN
THE WINTER WX ADVISORY.
ELSEWHERE ACROSS NORTHEAST MINNESOTA...LIGHT SNOW WITH 1 TO 3 INCHES
IN THE ARROWHEAD..ELSEWHERE NOT MUCH DURING THE DAY BEFORE COLDER
AIR MOVES IN AND THE LOW MOVES NORTH INTO ONTARIO THIS EVENING
RESULTING IN LIGHT SNOW/FLURRIES LINGERING THROUGH EARLY THURSDAY.
EAST OF THE WINTER WX ADVISORY MAINLY RAIN TODAY WITH OVER A HALF
INCH LIKELY. RAIN CHANGES TO SNOW THIS EVENING FROM WEST TO
EAST...WITH A FEW INCHES OF SNOW POSSIBLE UNTIL THE SNOW ENDS
TOWARDS THURSDAY MORNING.
FINALLY...FOR THURSDAY AFTERNOON HIGH PRESSURE BUILDING IN ACROSS
THE MID MISSISSIPPI VALLEY COULD RESULT IN SOME PARTIAL CLEARING IN
CENTRAL MINNESOTA...BUT UNLIKELY GIVEN POTENT STRATUS DECK IN PLACE.
TEMPS FALL TO THE MID TEENS TO MID 20S TONIGHT AS PRECIP CHANGES
OVER TO SNOW...THEN ONLY CLIMBING AROUND 5 DEGREES TO THE 20S ON
THURSDAY AFTERNOON. WEST WINDS LATE TONIGHT INTO THURSDAY COULD BE
BREEZY FOR A TIME...THEN DIMINISH TOWARDS THURSDAY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
THURSDAY NIGHT AND FRIDAY LOOK TO BE A QUIET LULL IN BETWEEN
SYSTEMS. THE MAIN QUESTION DURING THIS PERIOD WILL BE WHAT THE
CLOUD COVER DOES...AND ITS EFFECT ON TEMPERATURES. THE TREND THIS
TIME OF YEAR IS THAT UNLESS WE HAVE STRONG COLD DRY ADVECTION THAT
THOROUGHLY MIX OUT THE STRATUS...WE ARE LIKELY TO REMAIN STUCK IN
THE STRATUS IN BETWEEN THE SYSTEMS. SO...HAVE STAYED WITH A
CLOUDIER SOLUTION FOR NOW WITH NO GOOD STRONG PUSH TO GET RID OF THE
STRATUS AND HAVE STAYED WITH MODERATED TEMPERATURES THROUGHOUT.
HOWEVER...IF IT LOOKS LIKE WE MIGHT ACTUALLY CLEAR OUT AFTER
ALL...MY TEMPS ARE NOT COLD ENOUGH ALL AROUND. AS A FOOT
NOTE...HAVE NOTICED THE NAM RUNNING A WEAK FAST MOVING SHORTWAVE
ACROSS PARTS OF THE FORECAST AREA THURSDAY NIGHT...BUT IT IS THE
ONLY MODEL DOING THAT FOR NOW AND WHILE THE PREVIOUS RUNS HAVE
IT...THE TRACK HAS BEEN DRIFTING ABOUT AND REMAINS QUITE WEAK AND
MOSTLY SOUTH OF THE FORECAST AREA. SO...HAVE LEFT IT OUT FOR NOW.
THE NEXT SIGNIFICANT STORM MOVES THROUGH THE FORECAST AREA BEGINNING
FRIDAY NIGHT...AND CONTINUING SATURDAY BEFORE ENDING SATURDAY NIGHT
OR EARLY SUNDAY DEPENDING HOW MUCH LAKE EFFECT SNOW DEVELOPS. THE
MODELS ARE FAIRLY CONSISTENT IN BRINGING AN INVERTED SURFACE TROUGH
ACROSS THE FORECAST AREA DURING THE DAY ON SATURDAY...ASSOCIATED
WITH AN 850MB LOW THAT TRACKS FROM SE SD...EAST-NORTHEAST TO EASTERN
UPPER MICHIGAN DURING THE DAY ON SATURDAY. FOR NOW THIS KEEPS THE
FORECAST AREA IN BELOW ZERO TEMPERATURES ALOFT AND OUR PRECIPITATION
TYPE ALL SNOW...WITH NEAR TO A LITTLE HIGHER THAN NORMAL SNOW WATER
RATIOS FOR DECEMBER. MY INITIAL THOUGHTS BRING A SOLID 2 TO 4
INCHES ACROSS THE FORECAST AREA DURING THE EVENT...BUT WILL HAVE TO
WAIT AND SEE HOW THIS ONE DEVELOPS.
IT LOOKS LIKE ANOTHER STORM SYSTEM IS GOING TO MOVE ACROSS THE
MIDWEST ON MONDAY THROUGH TUESDAY...BRINGING ANOTHER CHANCE FOR
PRECIPITATION TO THE REGION. HOWEVER...THE LATEST MODELS ARE
KEEPING THIS SYSTEM MAINLY SOUTH OF THE FORECAST AREA AND HAVE PUT
IN LOWER POPS THAN WHAT WE PREVIOUSLY HAD TO TREND TOWARDS A DRIER
FORECAST. WILL HAVE TO SEE IF THIS TREND CONTINUES BEFORE REMOVING
THEM COMPLETELY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1140 AM CST WED DEC 23 2015
EXPECT IFR TO LIFR WITH CIGS BLO OVC010 AND VSBYS LESS THAN 1/2SM
IN MAINLY LIGHT SNOW AND FOG FOR MOST OF THE AREA. THESE
CONDITIONS WILL CONTINUE FOR MUCH OF THE PERIOD...UNTIL AFT 12Z
WHEN CONDITIONS WILL IMPROVE TO MVFR. THE EXCEPTION WILL BE IN THE
KBRD AREA WHERE CURRENT VFR CONDITIONS WILL LOWER TO MVFR AND
MAYBE IFR CONDITIONS LATER THIS AFTERNOON WITH SOME OCNL -SN.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 20 24 15 / 90 70 10 10
INL 34 21 23 11 / 20 50 30 10
BRD 33 18 24 15 / 20 10 10 0
HYR 34 23 28 15 / 100 100 20 10
ASX 36 26 29 20 / 100 100 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
WIZ001>003-006>008.
MN...NONE.
LS...SMALL CRAFT ADVISORY FROM 2 AM TO 6 PM CST THURSDAY FOR LSZ121-
140>148.
&&
$$
UPDATE...HUYCK
SHORT TERM...JJM
LONG TERM...LE
AVIATION...CLC
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
915 AM CST WED DEC 23 2015
.UPDATE...
ISSUED AT 915 AM CST WED DEC 23 2015
UPDATED WEATHER TYPES FOR TODAY THROUGH 00Z. HAVE HAD REPORTS THIS
MORNING OF SLEET/RAIN MIX IN SOUTHERN WASHBURN COUNTY AND A
SNOW/RAIN MIX IN HAYWARD IN THE PAST FEW HOURS. STILL THINKING THE
COLUMN WILL COOL AND TREND TOWARD BETTER ICE CRYSTAL SEEDING
THROUGH THIS MORNING AS PRECIP RATES INCREASE...RESULTING IN
BETTER SNOW COVERAGE. HAVE INCLUDED A BIT MORE SLEET AND A
BROADER AREA OF RA/SN THROUGH THIS MORNING AND INTO THE AFTERNOON.
ALSO INCREASED COVERAGE OF DZ/FZDZ THROUGHOUT THE DAY IN AREAS NOT
EXPERIENCING THE HEAVIER PRECIPITATION. ALSO THREW IN A MENTION OF
FOG WHICH HAS BEEN OBSERVED AT SEVERAL SITES THIS MORNING.
UPDATE ISSUED AT 630 AM CST WED DEC 23 2015
MINOR UPDATE TO POPS AND WEATHER...IN GENERAL FORECAST REMAINS ON
TRACK WITH A LIGHT WINTRY MIX QUICKLY CHANGING TO MAINLY SNOW
WEST OF HIGHWAY 63 IN NW WISCONSIN AND MORE RAIN THAN SNOW EAST OF
HIGHWAY 63.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
RAIN/SNOW WILL QUICKLY SPREAD ACROSS NORTHWEST WISCONSIN AND PARTS
OF NORTHEAST MINNESOTA TODAY RESULTING IN A QUICK FEW INCHES OF SNOW
FOR PARTS OF THE REGION. WHERE THE RAIN/SNOW LINE WILL BE IS STILL
DIFFICULT TO DETERMINE EVEN AT THIS SHORT TIME RANGE...BUT
CONFIDENCE HAS INCREASED IN COVERAGE OF PRECIPITATION /TRENDING
FARTHER WEST/ INTENSITY /HIGHER AMOUNTS/ AND RANGE OF PRECIP TYPES
EXPECTED /MAINLY JUST RAIN OR SNOW WITH LITTLE MIX/. RAIN/SNOW ENDS
QUICKLY FROM WEST TO EAST LATE TONIGHT WITH LINGERING FLURRIES
POSSIBLE INTO EARLY THURSDAY. WHEN IT IS ALL DONE THERE WILL LIKELY
BE A SWATH OF 2 TO 4 INCHES OF SNOW ACROSS A PORTION OF NORTHWEST
WISCONSIN...WITH OTHER LOCATIONS EXPERIENCE MAINLY RAIN ENDING AS
LIGHT SNOW.
ON THE SYNOPTIC SCALE A MID-LEVEL TROUGH AXIS WILL SWING NORTHEAST
FROM THE LOWER MISSOURI RIVER VALLEY INTO THE UPPER GREAT LAKES
TODAY. WHILE A POTENT LOW PRESSURE SYSTEM OVER THE RED RIVER VALLEY
MOVES NORTH INTO NORTHWEST ONTARIO IT WILL WEAKEN WHILE A STRONG AND
BROADER LOW PRESSURE DEVELOPS IN NORTHERN MISSOURI LATE THIS MORNING
MOVING NORTH-NORTHEAST INTO THE U.P. THIS EVENING. IN ADDITION TO
THE MID-LEVEL TROUGH A 120-130 KT JET STREAK DEVELOPS OVER THE
NORTHLAND LATE THIS MORNING RESULTING IN UPPER LEVEL DIVERGENCE
ACROSS NORTHERN WISCONSIN THIS AFTERNOON. FINALLY...WARM AIR
ADVECTION ONGOING AT LOW LEVELS HAS RAISED TEMPS TO THE MID 30S
ACROSS NORTHERN WISCONSIN WITH MODEL SOUNDINGS INDICATING A FAIRLY
WARM LAYER ALOFT...AS VERIFIED BY THE MPX 00Z SOUNDING. IN GENERAL
THE TREND IN GUIDANCE HAS BEEN A WESTWARD SHIFT AND STRONGER LARGE-
SCALE LIFT AS THE MID-LEVEL TROUGH RAPIDLY APPROACHES AND HEIGHTS
FALL THIS AFTERNOON. THE HRRR ACCENTUATES THIS TREND WITH RUNS THIS
MORNING COMING IN EVEN FURTHER WEST THAN MOST OF THE 00Z MODEL SUITE.
WHILE TEMPS ARE IN THE MID 30S ACROSS NORTHWEST WISCONSIN DEW POINTS
ARE STILL NEAR TO BELOW FREEZING...AND ONCE LOW LEVELS SATURATE
THINK THERE WILL BE A QUICK TRANSITION FROM LIGHT RAIN/DRIZZLE TO
SNOW ACROSS PARTS OF NORTHWEST WISCONSIN. THE RAIN/SNOW TRANSITION
LINE IS VERY CHALLENGING FOR TODAYS FORECAST WHICH RESULTS IN A
FAIRLY HIGH BUST POTENTIAL...BUT WITH THE LIKELIHOOD OF INTENSE
PRECIP AND TEMPS AT THE SFC AND THROUGH THE COLUMN COLD ENOUGH TO
SUPPORT SNOW BELIEVE THERE WILL BE A SWATH OF 2 TO 5 INCHES LATE
THIS MORNING INTO THE EARLY AFTERNOON. THUS...DECIDED TO GO WITH A
WINTER WX ADVISORY. THE RAIN/SNOW LINE LOOKS TO BE IN WESTERN
ASHLAND/SAWYER COUNTIES...AND DESPITE MOST OF THOSE COUNTIES
PROBABLY RECEIVING MAINLY RAIN TODAY THE FACT THAT /1/ THERE IS
STILL SOME UNCERTAINTY IN THIS FORECAST AND /2/ THE MOST POPULATED
CITIES IN EACH COUNTY ARE EXPECTED TO RECEIVE SNOW IS WHY WE DECIDED
TO ISSUE THE WINTER WX ADVISORY FOR THOSE COUNTIES. ON THE WEST
THERE WILL BE A SHARP CUT-OFF FOR WHERE THE ACCUMULATING SNOW
FALLS...WITH THIS LINE PROBABLY CLOSE TO THE TWIN PORTS. FOR NOW
HAVE 1 TO 3 INCHES OF SNOW FOR THE TWIN PORTS...THERE IS THE
POTENTIAL LITTLE IF ANY PRECIP OCCURS BUT DO NOT THINK THERE IS
POTENTIAL FOR MORE THAN THREE INCHES...SO DID NOT INCLUDE DULUTH IN
THE WINTER WX ADVISORY.
ELSEWHERE ACROSS NORTHEAST MINNESOTA...LIGHT SNOW WITH 1 TO 3 INCHES
IN THE ARROWHEAD..ELSEWHERE NOT MUCH DURING THE DAY BEFORE COLDER
AIR MOVES IN AND THE LOW MOVES NORTH INTO ONTARIO THIS EVENING
RESULTING IN LIGHT SNOW/FLURRIES LINGERING THROUGH EARLY THURSDAY.
EAST OF THE WINTER WX ADVISORY MAINLY RAIN TODAY WITH OVER A HALF
INCH LIKELY. RAIN CHANGES TO SNOW THIS EVENING FROM WEST TO
EAST...WITH A FEW INCHES OF SNOW POSSIBLE UNTIL THE SNOW ENDS
TOWARDS THURSDAY MORNING.
FINALLY...FOR THURSDAY AFTERNOON HIGH PRESSURE BUILDING IN ACROSS
THE MID MISSISSIPPI VALLEY COULD RESULT IN SOME PARTIAL CLEARING IN
CENTRAL MINNESOTA...BUT UNLIKELY GIVEN POTENT STRATUS DECK IN PLACE.
TEMPS FALL TO THE MID TEENS TO MID 20S TONIGHT AS PRECIP CHANGES
OVER TO SNOW...THEN ONLY CLIMBING AROUND 5 DEGREES TO THE 20S ON
THURSDAY AFTERNOON. WEST WINDS LATE TONIGHT INTO THURSDAY COULD BE
BREEZY FOR A TIME...THEN DIMINISH TOWARDS THURSDAY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
THURSDAY NIGHT AND FRIDAY LOOK TO BE A QUIET LULL IN BETWEEN
SYSTEMS. THE MAIN QUESTION DURING THIS PERIOD WILL BE WHAT THE
CLOUD COVER DOES...AND ITS EFFECT ON TEMPERATURES. THE TREND THIS
TIME OF YEAR IS THAT UNLESS WE HAVE STRONG COLD DRY ADVECTION THAT
THOROUGHLY MIX OUT THE STRATUS...WE ARE LIKELY TO REMAIN STUCK IN
THE STRATUS IN BETWEEN THE SYSTEMS. SO...HAVE STAYED WITH A
CLOUDIER SOLUTION FOR NOW WITH NO GOOD STRONG PUSH TO GET RID OF THE
STRATUS AND HAVE STAYED WITH MODERATED TEMPERATURES THROUGHOUT.
HOWEVER...IF IT LOOKS LIKE WE MIGHT ACTUALLY CLEAR OUT AFTER
ALL...MY TEMPS ARE NOT COLD ENOUGH ALL AROUND. AS A FOOT
NOTE...HAVE NOTICED THE NAM RUNNING A WEAK FAST MOVING SHORTWAVE
ACROSS PARTS OF THE FORECAST AREA THURSDAY NIGHT...BUT IT IS THE
ONLY MODEL DOING THAT FOR NOW AND WHILE THE PREVIOUS RUNS HAVE
IT...THE TRACK HAS BEEN DRIFTING ABOUT AND REMAINS QUITE WEAK AND
MOSTLY SOUTH OF THE FORECAST AREA. SO...HAVE LEFT IT OUT FOR NOW.
THE NEXT SIGNIFICANT STORM MOVES THROUGH THE FORECAST AREA BEGINNING
FRIDAY NIGHT...AND CONTINUING SATURDAY BEFORE ENDING SATURDAY NIGHT
OR EARLY SUNDAY DEPENDING HOW MUCH LAKE EFFECT SNOW DEVELOPS. THE
MODELS ARE FAIRLY CONSISTENT IN BRINGING AN INVERTED SURFACE TROUGH
ACROSS THE FORECAST AREA DURING THE DAY ON SATURDAY...ASSOCIATED
WITH AN 850MB LOW THAT TRACKS FROM SE SD...EAST-NORTHEAST TO EASTERN
UPPER MICHIGAN DURING THE DAY ON SATURDAY. FOR NOW THIS KEEPS THE
FORECAST AREA IN BELOW ZERO TEMPERATURES ALOFT AND OUR PRECIPITATION
TYPE ALL SNOW...WITH NEAR TO A LITTLE HIGHER THAN NORMAL SNOW WATER
RATIOS FOR DECEMBER. MY INITIAL THOUGHTS BRING A SOLID 2 TO 4
INCHES ACROSS THE FORECAST AREA DURING THE EVENT...BUT WILL HAVE TO
WAIT AND SEE HOW THIS ONE DEVELOPS.
IT LOOKS LIKE ANOTHER STORM SYSTEM IS GOING TO MOVE ACROSS THE
MIDWEST ON MONDAY THROUGH TUESDAY...BRINGING ANOTHER CHANCE FOR
PRECIPITATION TO THE REGION. HOWEVER...THE LATEST MODELS ARE
KEEPING THIS SYSTEM MAINLY SOUTH OF THE FORECAST AREA AND HAVE PUT
IN LOWER POPS THAN WHAT WE PREVIOUSLY HAD TO TREND TOWARDS A DRIER
FORECAST. WILL HAVE TO SEE IF THIS TREND CONTINUES BEFORE REMOVING
THEM COMPLETELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 535 AM CST WED DEC 23 2015
WIDESPREAD IFR CONDITIONS THIS MORNING TO CONTINUE THROUGH MUCH OF
THE NEXT 24 HOURS. A RAIN/SNOW MIXTURE TO SPREAD ACROSS THE
EASTERN TERMINALS...MAINLY KHYR...KDLH AND KHIB THROUGH
APPROXIMATELY 06Z TONIGHT BEFORE SLOWLY ENDING FROM WEST TO EAST.
SOME LOCATIONS TO EVEN DROP TO LIFR FOR A FEW HOURS THIS
AFTERNOON. IMPROVEMENT TO MVFR POSSIBLE FOR MN TERMINALS AFTER 09Z
TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 20 24 15 / 90 70 10 10
INL 34 21 23 11 / 20 50 30 10
BRD 33 18 24 15 / 20 20 10 0
HYR 36 23 28 15 / 100 80 20 10
ASX 36 27 29 20 / 100 90 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
WIZ001>003-006>008.
MN...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LSZ140-141.
&&
$$
UPDATE...HUYCK
SHORT TERM...JJM
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
632 AM CST WED DEC 23 2015
.UPDATE...
ISSUED AT 630 AM CST WED DEC 23 2015
MINOR UPDATE TO POPS AND WEATHER...IN GENERAL FORECAST REMAINS ON
TRACK WITH A LIGHT WINTRY MIX QUICKING CHANGING TO MAINLY SNOW
WEST OF HIGHWAY 63 IN NW WISCONSIN AND MORE RAIN THAN SNOW EAST
OF HIGHWAY 63.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
RAIN/SNOW WILL QUICKLY SPREAD ACROSS NORTHWEST WISCONSIN AND PARTS
OF NORTHEAST MINNESOTA TODAY RESULTING IN A QUICK FEW INCHES OF SNOW
FOR PARTS OF THE REGION. WHERE THE RAIN/SNOW LINE WILL BE IS STILL
DIFFICULT TO DETERMINE EVEN AT THIS SHORT TIME RANGE...BUT
CONFIDENCE HAS INCREASED IN COVERAGE OF PRECIPITATION /TRENDING
FARTHER WEST/ INTENSITY /HIGHER AMOUNTS/ AND RANGE OF PRECIP TYPES
EXPECTED /MAINLY JUST RAIN OR SNOW WITH LITTLE MIX/. RAIN/SNOW ENDS
QUICKLY FROM WEST TO EAST LATE TONIGHT WITH LINGERING FLURRIES
POSSIBLE INTO EARLY THURSDAY. WHEN IT IS ALL DONE THERE WILL LIKELY
BE A SWATH OF 2 TO 4 INCHES OF SNOW ACROSS A PORTION OF NORTHWEST
WISCONSIN...WITH OTHER LOCATIONS EXPERIENCE MAINLY RAIN ENDING AS
LIGHT SNOW.
ON THE SYNOPTIC SCALE A MID-LEVEL TROUGH AXIS WILL SWING NORTHEAST
FROM THE LOWER MISSOURI RIVER VALLEY INTO THE UPPER GREAT LAKES
TODAY. WHILE A POTENT LOW PRESSURE SYSTEM OVER THE RED RIVER VALLEY
MOVES NORTH INTO NORTHWEST ONTARIO IT WILL WEAKEN WHILE A STRONG AND
BROADER LOW PRESSURE DEVELOPS IN NORTHERN MISSOURI LATE THIS MORNING
MOVING NORTH-NORTHEAST INTO THE U.P. THIS EVENING. IN ADDITION TO
THE MID-LEVEL TROUGH A 120-130 KT JET STREAK DEVELOPS OVER THE
NORTHLAND LATE THIS MORNING RESULTING IN UPPER LEVEL DIVERGENCE
ACROSS NORTHERN WISCONSIN THIS AFTERNOON. FINALLY...WARM AIR
ADVECTION ONGOING AT LOW LEVELS HAS RAISED TEMPS TO THE MID 30S
ACROSS NORTHERN WISCONSIN WITH MODEL SOUNDINGS INDICATING A FAIRLY
WARM LAYER ALOFT...AS VERIFIED BY THE MPX 00Z SOUNDING. IN GENERAL
THE TREND IN GUIDANCE HAS BEEN A WESTWARD SHIFT AND STRONGER LARGE-
SCALE LIFT AS THE MID-LEVEL TROUGH RAPIDLY APPROACHES AND HEIGHTS
FALL THIS AFTERNOON. THE HRRR ACCENTUATES THIS TREND WITH RUNS THIS
MORNING COMING IN EVEN FURTHER WEST THAN MOST OF THE 00Z MODEL SUITE.
WHILE TEMPS ARE IN THE MID 30S ACROSS NORTHWEST WISCONSIN DEW POINTS
ARE STILL NEAR TO BELOW FREEZING...AND ONCE LOW LEVELS SATURATE
THINK THERE WILL BE A QUICK TRANSITION FROM LIGHT RAIN/DRIZZLE TO
SNOW ACROSS PARTS OF NORTHWEST WISCONSIN. THE RAIN/SNOW TRANSITION
LINE IS VERY CHALLENGING FOR TODAYS FORECAST WHICH RESULTS IN A
FAIRLY HIGH BUST POTENTIAL...BUT WITH THE LIKELIHOOD OF INTENSE
PRECIP AND TEMPS AT THE SFC AND THROUGH THE COLUMN COLD ENOUGH TO
SUPPORT SNOW BELIEVE THERE WILL BE A SWATH OF 2 TO 5 INCHES LATE
THIS MORNING INTO THE EARLY AFTERNOON. THUS...DECIDED TO GO WITH A
WINTER WX ADVISORY. THE RAIN/SNOW LINE LOOKS TO BE IN WESTERN
ASHLAND/SAWYER COUNTIES...AND DESPITE MOST OF THOSE COUNTIES
PROBABLY RECEIVING MAINLY RAIN TODAY THE FACT THAT /1/ THERE IS
STILL SOME UNCERTAINTY IN THIS FORECAST AND /2/ THE MOST POPULATED
CITIES IN EACH COUNTY ARE EXPECTED TO RECEIVE SNOW IS WHY WE DECIDED
TO ISSUE THE WINTER WX ADVISORY FOR THOSE COUNTIES. ON THE WEST
THERE WILL BE A SHARP CUT-OFF FOR WHERE THE ACCUMULATING SNOW
FALLS...WITH THIS LINE PROBABLY CLOSE TO THE TWIN PORTS. FOR NOW
HAVE 1 TO 3 INCHES OF SNOW FOR THE TWIN PORTS...THERE IS THE
POTENTIAL LITTLE IF ANY PRECIP OCCURS BUT DO NOT THINK THERE IS
POTENTIAL FOR MORE THAN THREE INCHES...SO DID NOT INCLUDE DULUTH IN
THE WINTER WX ADVISORY.
ELSEWHERE ACROSS NORTHEAST MINNESOTA...LIGHT SNOW WITH 1 TO 3 INCHES
IN THE ARROWHEAD..ELSEWHERE NOT MUCH DURING THE DAY BEFORE COLDER
AIR MOVES IN AND THE LOW MOVES NORTH INTO ONTARIO THIS EVENING
RESULTING IN LIGHT SNOW/FLURRIES LINGERING THROUGH EARLY THURSDAY.
EAST OF THE WINTER WX ADVISORY MAINLY RAIN TODAY WITH OVER A HALF
INCH LIKELY. RAIN CHANGES TO SNOW THIS EVENING FROM WEST TO
EAST...WITH A FEW INCHES OF SNOW POSSIBLE UNTIL THE SNOW ENDS
TOWARDS THURSDAY MORNING.
FINALLY...FOR THURSDAY AFTERNOON HIGH PRESSURE BUILDING IN ACROSS
THE MID MISSISSIPPI VALLEY COULD RESULT IN SOME PARTIAL CLEARING IN
CENTRAL MINNESOTA...BUT UNLIKELY GIVEN POTENT STRATUS DECK IN PLACE.
TEMPS FALL TO THE MID TEENS TO MID 20S TONIGHT AS PRECIP CHANGES
OVER TO SNOW...THEN ONLY CLIMBING AROUND 5 DEGREES TO THE 20S ON
THURSDAY AFTERNOON. WEST WINDS LATE TONIGHT INTO THURSDAY COULD BE
BREEZY FOR A TIME...THEN DIMINISH TOWARDS THURSDAY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
THURSDAY NIGHT AND FRIDAY LOOK TO BE A QUIET LULL IN BETWEEN
SYSTEMS. THE MAIN QUESTION DURING THIS PERIOD WILL BE WHAT THE
CLOUD COVER DOES...AND ITS EFFECT ON TEMPERATURES. THE TREND THIS
TIME OF YEAR IS THAT UNLESS WE HAVE STRONG COLD DRY ADVECTION THAT
THOROUGHLY MIX OUT THE STRATUS...WE ARE LIKELY TO REMAIN STUCK IN
THE STRATUS IN BETWEEN THE SYSTEMS. SO...HAVE STAYED WITH A
CLOUDIER SOLUTION FOR NOW WITH NO GOOD STRONG PUSH TO GET RID OF THE
STRATUS AND HAVE STAYED WITH MODERATED TEMPERATURES THROUGHOUT.
HOWEVER...IF IT LOOKS LIKE WE MIGHT ACTUALLY CLEAR OUT AFTER
ALL...MY TEMPS ARE NOT COLD ENOUGH ALL AROUND. AS A FOOT
NOTE...HAVE NOTICED THE NAM RUNNING A WEAK FAST MOVING SHORTWAVE
ACROSS PARTS OF THE FORECAST AREA THURSDAY NIGHT...BUT IT IS THE
ONLY MODEL DOING THAT FOR NOW AND WHILE THE PREVIOUS RUNS HAVE
IT...THE TRACK HAS BEEN DRIFTING ABOUT AND REMAINS QUITE WEAK AND
MOSTLY SOUTH OF THE FORECAST AREA. SO...HAVE LEFT IT OUT FOR NOW.
THE NEXT SIGNIFICANT STORM MOVES THROUGH THE FORECAST AREA BEGINNING
FRIDAY NIGHT...AND CONTINUING SATURDAY BEFORE ENDING SATURDAY NIGHT
OR EARLY SUNDAY DEPENDING HOW MUCH LAKE EFFECT SNOW DEVELOPS. THE
MODELS ARE FAIRLY CONSISTENT IN BRINGING AN INVERTED SURFACE TROUGH
ACROSS THE FORECAST AREA DURING THE DAY ON SATURDAY...ASSOCIATED
WITH AN 850MB LOW THAT TRACKS FROM SE SD...EAST-NORTHEAST TO EASTERN
UPPER MICHIGAN DURING THE DAY ON SATURDAY. FOR NOW THIS KEEPS THE
FORECAST AREA IN BELOW ZERO TEMPERATURES ALOFT AND OUR PRECIPITATION
TYPE ALL SNOW...WITH NEAR TO A LITTLE HIGHER THAN NORMAL SNOW WATER
RATIOS FOR DECEMBER. MY INITIAL THOUGHTS BRING A SOLID 2 TO 4
INCHES ACROSS THE FORECAST AREA DURING THE EVENT...BUT WILL HAVE TO
WAIT AND SEE HOW THIS ONE DEVELOPS.
IT LOOKS LIKE ANOTHER STORM SYSTEM IS GOING TO MOVE ACROSS THE
MIDWEST ON MONDAY THROUGH TUESDAY...BRINGING ANOTHER CHANCE FOR
PRECIPITATION TO THE REGION. HOWEVER...THE LATEST MODELS ARE
KEEPING THIS SYSTEM MAINLY SOUTH OF THE FORECAST AREA AND HAVE PUT
IN LOWER POPS THAN WHAT WE PREVIOUSLY HAD TO TREND TOWARDS A DRIER
FORECAST. WILL HAVE TO SEE IF THIS TREND CONTINUES BEFORE REMOVING
THEM COMPLETELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 535 AM CST WED DEC 23 2015
WIDESPREAD IFR CONDITIONS THIS MORNING TO CONTINUE THROUGH MUCH OF
THE NEXT 24 HOURS. A RAIN/SNOW MIXTURE TO SPREAD ACROSS THE
EASTERN TERMINALS...MAINLY KHYR...KDLH AND KHIB THROUGH
APPROXIMATELY 06Z TONIGHT BEFORE SLOWLY ENDING FROM WEST TO EAST.
SOME LOCATIONS TO EVEN DROP TO LIFR FOR A FEW HOURS THIS
AFTERNOON. IMPROVEMENT TO MVFR POSSIBLE FOR MN TERMINALS AFTER 09Z
TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 20 24 15 / 80 60 10 10
INL 33 21 23 11 / 20 50 30 10
BRD 33 18 24 15 / 20 20 10 0
HYR 36 23 28 15 / 100 80 20 10
ASX 36 27 29 20 / 100 70 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
WIZ001>003-006>008.
MN...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LSZ140-141.
&&
$$
UPDATE...JJM
SHORT TERM...JJM
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
540 AM CST WED DEC 23 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
RAIN/SNOW WILL QUICKLY SPREAD ACROSS NORTHWEST WISCONSIN AND PARTS
OF NORTHEAST MINNESOTA TODAY RESULTING IN A QUICK FEW INCHES OF SNOW
FOR PARTS OF THE REGION. WHERE THE RAIN/SNOW LINE WILL BE IS STILL
DIFFICULT TO DETERMINE EVEN AT THIS SHORT TIME RANGE...BUT
CONFIDENCE HAS INCREASED IN COVERAGE OF PRECIPITATION /TRENDING
FARTHER WEST/ INTENSITY /HIGHER AMOUNTS/ AND RANGE OF PRECIP TYPES
EXPECTED /MAINLY JUST RAIN OR SNOW WITH LITTLE MIX/. RAIN/SNOW ENDS
QUICKLY FROM WEST TO EAST LATE TONIGHT WITH LINGERING FLURRIES
POSSIBLE INTO EARLY THURSDAY. WHEN IT IS ALL DONE THERE WILL LIKELY
BE A SWATH OF 2 TO 4 INCHES OF SNOW ACROSS A PORTION OF NORTHWEST
WISCONSIN...WITH OTHER LOCATIONS EXPERIENCE MAINLY RAIN ENDING AS
LIGHT SNOW.
ON THE SYNOPTIC SCALE A MID-LEVEL TROUGH AXIS WILL SWING NORTHEAST
FROM THE LOWER MISSOURI RIVER VALLEY INTO THE UPPER GREAT LAKES
TODAY. WHILE A POTENT LOW PRESSURE SYSTEM OVER THE RED RIVER VALLEY
MOVES NORTH INTO NORTHWEST ONTARIO IT WILL WEAKEN WHILE A STRONG AND
BROADER LOW PRESSURE DEVELOPS IN NORTHERN MISSOURI LATE THIS MORNING
MOVING NORTH-NORTHEAST INTO THE U.P. THIS EVENING. IN ADDITION TO
THE MID-LEVEL TROUGH A 120-130 KT JET STREAK DEVELOPS OVER THE
NORTHLAND LATE THIS MORNING RESULTING IN UPPER LEVEL DIVERGENCE
ACROSS NORTHERN WISCONSIN THIS AFTERNOON. FINALLY...WARM AIR
ADVECTION ONGOING AT LOW LEVELS HAS RAISED TEMPS TO THE MID 30S
ACROSS NORTHERN WISCONSIN WITH MODEL SOUNDINGS INDICATING A FAIRLY
WARM LAYER ALOFT...AS VERIFIED BY THE MPX 00Z SOUNDING. IN GENERAL
THE TREND IN GUIDANCE HAS BEEN A WESTWARD SHIFT AND STRONGER LARGE-
SCALE LIFT AS THE MID-LEVEL TROUGH RAPIDLY APPROACHES AND HEIGHTS
FALL THIS AFTERNOON. THE HRRR ACCENTUATES THIS TREND WITH RUNS THIS
MORNING COMING IN EVEN FURTHER WEST THAN MOST OF THE 00Z MODEL SUITE.
WHILE TEMPS ARE IN THE MID 30S ACROSS NORTHWEST WISCONSIN DEW POINTS
ARE STILL NEAR TO BELOW FREEZING...AND ONCE LOW LEVELS SATURATE
THINK THERE WILL BE A QUICK TRANSITION FROM LIGHT RAIN/DRIZZLE TO
SNOW ACROSS PARTS OF NORTHWEST WISCONSIN. THE RAIN/SNOW TRANSITION
LINE IS VERY CHALLENGING FOR TODAYS FORECAST WHICH RESULTS IN A
FAIRLY HIGH BUST POTENTIAL...BUT WITH THE LIKELIHOOD OF INTENSE
PRECIP AND TEMPS AT THE SFC AND THROUGH THE COLUMN COLD ENOUGH TO
SUPPORT SNOW BELIEVE THERE WILL BE A SWATH OF 2 TO 5 INCHES LATE
THIS MORNING INTO THE EARLY AFTERNOON. THUS...DECIDED TO GO WITH A
WINTER WX ADVISORY. THE RAIN/SNOW LINE LOOKS TO BE IN WESTERN
ASHLAND/SAWYER COUNTIES...AND DESPITE MOST OF THOSE COUNTIES
PROBABLY RECEIVING MAINLY RAIN TODAY THE FACT THAT /1/ THERE IS
STILL SOME UNCERTAINTY IN THIS FORECAST AND /2/ THE MOST POPULATED
CITIES IN EACH COUNTY ARE EXPECTED TO RECEIVE SNOW IS WHY WE DECIDED
TO ISSUE THE WINTER WX ADVISORY FOR THOSE COUNTIES. ON THE WEST
THERE WILL BE A SHARP CUT-OFF FOR WHERE THE ACCUMULATING SNOW
FALLS...WITH THIS LINE PROBABLY CLOSE TO THE TWIN PORTS. FOR NOW
HAVE 1 TO 3 INCHES OF SNOW FOR THE TWIN PORTS...THERE IS THE
POTENTIAL LITTLE IF ANY PRECIP OCCURS BUT DO NOT THINK THERE IS
POTENTIAL FOR MORE THAN THREE INCHES...SO DID NOT INCLUDE DULUTH IN
THE WINTER WX ADVISORY.
ELSEWHERE ACROSS NORTHEAST MINNESOTA...LIGHT SNOW WITH 1 TO 3 INCHES
IN THE ARROWHEAD..ELSEWHERE NOT MUCH DURING THE DAY BEFORE COLDER
AIR MOVES IN AND THE LOW MOVES NORTH INTO ONTARIO THIS EVENING
RESULTING IN LIGHT SNOW/FLURRIES LINGERING THROUGH EARLY THURSDAY.
EAST OF THE WINTER WX ADVISORY MAINLY RAIN TODAY WITH OVER A HALF
INCH LIKELY. RAIN CHANGES TO SNOW THIS EVENING FROM WEST TO
EAST...WITH A FEW INCHES OF SNOW POSSIBLE UNTIL THE SNOW ENDS
TOWARDS THURSDAY MORNING.
FINALLY...FOR THURSDAY AFTERNOON HIGH PRESSURE BUILDING IN ACROSS
THE MID MISSISSIPPI VALLEY COULD RESULT IN SOME PARTIAL CLEARING IN
CENTRAL MINNESOTA...BUT UNLIKELY GIVEN POTENT STRATUS DECK IN PLACE.
TEMPS FALL TO THE MID TEENS TO MID 20S TONIGHT AS PRECIP CHANGES
OVER TO SNOW...THEN ONLY CLIMBING AROUND 5 DEGREES TO THE 20S ON
THURSDAY AFTERNOON. WEST WINDS LATE TONIGHT INTO THURSDAY COULD BE
BREEZY FOR A TIME...THEN DIMINISH TOWARDS THURSDAY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
THURSDAY NIGHT AND FRIDAY LOOK TO BE A QUIET LULL IN BETWEEN
SYSTEMS. THE MAIN QUESTION DURING THIS PERIOD WILL BE WHAT THE
CLOUD COVER DOES...AND ITS EFFECT ON TEMPERATURES. THE TREND THIS
TIME OF YEAR IS THAT UNLESS WE HAVE STRONG COLD DRY ADVECTION THAT
THOROUGHLY MIX OUT THE STRATUS...WE ARE LIKELY TO REMAIN STUCK IN
THE STRATUS IN BETWEEN THE SYSTEMS. SO...HAVE STAYED WITH A
CLOUDIER SOLUTION FOR NOW WITH NO GOOD STRONG PUSH TO GET RID OF THE
STRATUS AND HAVE STAYED WITH MODERATED TEMPERATURES THROUGHOUT.
HOWEVER...IF IT LOOKS LIKE WE MIGHT ACTUALLY CLEAR OUT AFTER
ALL...MY TEMPS ARE NOT COLD ENOUGH ALL AROUND. AS A FOOT
NOTE...HAVE NOTICED THE NAM RUNNING A WEAK FAST MOVING SHORTWAVE
ACROSS PARTS OF THE FORECAST AREA THURSDAY NIGHT...BUT IT IS THE
ONLY MODEL DOING THAT FOR NOW AND WHILE THE PREVIOUS RUNS HAVE
IT...THE TRACK HAS BEEN DRIFTING ABOUT AND REMAINS QUITE WEAK AND
MOSTLY SOUTH OF THE FORECAST AREA. SO...HAVE LEFT IT OUT FOR NOW.
THE NEXT SIGNIFICANT STORM MOVES THROUGH THE FORECAST AREA BEGINNING
FRIDAY NIGHT...AND CONTINUING SATURDAY BEFORE ENDING SATURDAY NIGHT
OR EARLY SUNDAY DEPENDING HOW MUCH LAKE EFFECT SNOW DEVELOPS. THE
MODELS ARE FAIRLY CONSISTENT IN BRINGING AN INVERTED SURFACE TROUGH
ACROSS THE FORECAST AREA DURING THE DAY ON SATURDAY...ASSOCIATED
WITH AN 850MB LOW THAT TRACKS FROM SE SD...EAST-NORTHEAST TO EASTERN
UPPER MICHIGAN DURING THE DAY ON SATURDAY. FOR NOW THIS KEEPS THE
FORECAST AREA IN BELOW ZERO TEMPERATURES ALOFT AND OUR PRECIPITATION
TYPE ALL SNOW...WITH NEAR TO A LITTLE HIGHER THAN NORMAL SNOW WATER
RATIOS FOR DECEMBER. MY INITIAL THOUGHTS BRING A SOLID 2 TO 4
INCHES ACROSS THE FORECAST AREA DURING THE EVENT...BUT WILL HAVE TO
WAIT AND SEE HOW THIS ONE DEVELOPS.
IT LOOKS LIKE ANOTHER STORM SYSTEM IS GOING TO MOVE ACROSS THE
MIDWEST ON MONDAY THROUGH TUESDAY...BRINGING ANOTHER CHANCE FOR
PRECIPITATION TO THE REGION. HOWEVER...THE LATEST MODELS ARE
KEEPING THIS SYSTEM MAINLY SOUTH OF THE FORECAST AREA AND HAVE PUT
IN LOWER POPS THAN WHAT WE PREVIOUSLY HAD TO TREND TOWARDS A DRIER
FORECAST. WILL HAVE TO SEE IF THIS TREND CONTINUES BEFORE REMOVING
THEM COMPLETELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 535 AM CST WED DEC 23 2015
WIDESPREAD IFR CONDITIONS THIS MORNING TO CONTINUE THROUGH MUCH OF
THE NEXT 24 HOURS. A RAIN/SNOW MIXTURE TO SPREAD ACROSS THE
EASTERN TERMINALS...MAINLY KHYR...KDLH AND KHIB THROUGH
APPROXIMATELY 06Z TONIGHT BEFORE SLOWLY ENDING FROM WEST TO EAST.
SOME LOCATIONS TO EVEN DROP TO LIFR FOR A FEW HOURS THIS
AFTERNOON. IMPROVEMENT TO MVFR POSSIBLE FOR MN TERMINALS AFTER 09Z
TONIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 20 24 15 / 80 60 10 10
INL 33 21 23 11 / 20 50 30 10
BRD 33 18 24 15 / 20 20 10 0
HYR 36 23 28 15 / 100 80 20 10
ASX 36 27 29 20 / 100 70 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR WIZ001>003-006>008.
MN...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LSZ140-141.
&&
$$
SHORT TERM...JJM
LONG TERM...LE
AVIATION...LE
AREA FORECAST DISCUSSION
NWS DULUTH MN
428 AM CST WED DEC 23 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
RAIN/SNOW WILL QUICKLY SPREAD ACROSS NORTHWEST WISCONSIN AND PARTS
OF NORTHEAST MINNESOTA TODAY RESULTING IN A QUICK FEW INCHES OF SNOW
FOR PARTS OF THE REGION. WHERE THE RAIN/SNOW LINE WILL BE IS STILL
DIFFICULT TO DETERMINE EVEN AT THIS SHORT TIME RANGE...BUT
CONFIDENCE HAS INCREASED IN COVERAGE OF PRECIPITATION /TRENDING
FARTHER WEST/ INTENSITY /HIGHER AMOUNTS/ AND RANGE OF PRECIP TYPES
EXPECTED /MAINLY JUST RAIN OR SNOW WITH LITTLE MIX/. RAIN/SNOW ENDS
QUICKLY FROM WEST TO EAST LATE TONIGHT WITH LINGERING FLURRIES
POSSIBLE INTO EARLY THURSDAY. WHEN IT IS ALL DONE THERE WILL LIKELY
BE A SWATH OF 2 TO 4 INCHES OF SNOW ACROSS A PORTION OF NORTHWEST
WISCONSIN...WITH OTHER LOCATIONS EXPERIENCE MAINLY RAIN ENDING AS
LIGHT SNOW.
ON THE SYNOPTIC SCALE A MID-LEVEL TROUGH AXIS WILL SWING NORTHEAST
FROM THE LOWER MISSOURI RIVER VALLEY INTO THE UPPER GREAT LAKES
TODAY. WHILE A POTENT LOW PRESSURE SYSTEM OVER THE RED RIVER VALLEY
MOVES NORTH INTO NORTHWEST ONTARIO IT WILL WEAKEN WHILE A STRONG AND
BROADER LOW PRESSURE DEVELOPS IN NORTHERN MISSOURI LATE THIS MORNING
MOVING NORTH-NORTHEAST INTO THE U.P. THIS EVENING. IN ADDITION TO
THE MID-LEVEL TROUGH A 120-130 KT JET STREAK DEVELOPS OVER THE
NORTHLAND LATE THIS MORNING RESULTING IN UPPER LEVEL DIVERGENCE
ACROSS NORTHERN WISCONSIN THIS AFTERNOON. FINALLY...WARM AIR
ADVECTION ONGOING AT LOW LEVELS HAS RAISED TEMPS TO THE MID 30S
ACROSS NORTHERN WISCONSIN WITH MODEL SOUNDINGS INDICATING A FAIRLY
WARM LAYER ALOFT...AS VERIFIED BY THE MPX 00Z SOUNDING. IN GENERAL
THE TREND IN GUIDANCE HAS BEEN A WESTWARD SHIFT AND STRONGER LARGE-
SCALE LIFT AS THE MID-LEVEL TROUGH RAPIDLY APPROACHES AND HEIGHTS
FALL THIS AFTERNOON. THE HRRR ACCENTUATES THIS TREND WITH RUNS THIS
MORNING COMING IN EVEN FURTHER WEST THAN MOST OF THE 00Z MODEL SUITE.
WHILE TEMPS ARE IN THE MID 30S ACROSS NORTHWEST WISCONSIN DEW POINTS
ARE STILL NEAR TO BELOW FREEZING...AND ONCE LOW LEVELS SATURATE
THINK THERE WILL BE A QUICK TRANSITION FROM LIGHT RAIN/DRIZZLE TO
SNOW ACROSS PARTS OF NORTHWEST WISCONSIN. THE RAIN/SNOW TRANSITION
LINE IS VERY CHALLENGING FOR TODAYS FORECAST WHICH RESULTS IN A
FAIRLY HIGH BUST POTENTIAL...BUT WITH THE LIKELIHOOD OF INTENSE
PRECIP AND TEMPS AT THE SFC AND THROUGH THE COLUMN COLD ENOUGH TO
SUPPORT SNOW BELIEVE THERE WILL BE A SWATH OF 2 TO 5 INCHES LATE
THIS MORNING INTO THE EARLY AFTERNOON. THUS...DECIDED TO GO WITH A
WINTER WX ADVISORY. THE RAIN/SNOW LINE LOOKS TO BE IN WESTERN
ASHLAND/SAWYER COUNTIES...AND DESPITE MOST OF THOSE COUNTIES
PROBABLY RECEIVING MAINLY RAIN TODAY THE FACT THAT /1/ THERE IS
STILL SOME UNCERTAINTY IN THIS FORECAST AND /2/ THE MOST POPULATED
CITIES IN EACH COUNTY ARE EXPECTED TO RECEIVE SNOW IS WHY WE DECIDED
TO ISSUE THE WINTER WX ADVISORY FOR THOSE COUNTIES. ON THE WEST
THERE WILL BE A SHARP CUT-OFF FOR WHERE THE ACCUMULATING SNOW
FALLS...WITH THIS LINE PROBABLY CLOSE TO THE TWIN PORTS. FOR NOW
HAVE 1 TO 3 INCHES OF SNOW FOR THE TWIN PORTS...THERE IS THE
POTENTIAL LITTLE IF ANY PRECIP OCCURS BUT DO NOT THINK THERE IS
POTENTIAL FOR MORE THAN THREE INCHES...SO DID NOT INCLUDE DULUTH IN
THE WINTER WX ADVISORY.
ELSEWHERE ACROSS NORTHEAST MINNESOTA...LIGHT SNOW WITH 1 TO 3 INCHES
IN THE ARROWHEAD..ELSEWHERE NOT MUCH DURING THE DAY BEFORE COLDER
AIR MOVES IN AND THE LOW MOVES NORTH INTO ONTARIO THIS EVENING
RESULTING IN LIGHT SNOW/FLURRIES LINGERING THROUGH EARLY THURSDAY.
EAST OF THE WINTER WX ADVISORY MAINLY RAIN TODAY WITH OVER A HALF
INCH LIKELY. RAIN CHANGES TO SNOW THIS EVENING FROM WEST TO
EAST...WITH A FEW INCHES OF SNOW POSSIBLE UNTIL THE SNOW ENDS
TOWARDS THURSDAY MORNING.
FINALLY...FOR THURSDAY AFTERNOON HIGH PRESSURE BUILDING IN ACROSS
THE MID MISSISSIPPI VALLEY COULD RESULT IN SOME PARTIAL CLEARING IN
CENTRAL MINNESOTA...BUT UNLIKELY GIVEN POTENT STRATUS DECK IN PLACE.
TEMPS FALL TO THE MID TEENS TO MID 20S TONIGHT AS PRECIP CHANGES
OVER TO SNOW...THEN ONLY CLIMBING AROUND 5 DEGREES TO THE 20S ON
THURSDAY AFTERNOON. WEST WINDS LATE TONIGHT INTO THURSDAY COULD BE
BREEZY FOR A TIME...THEN DIMINISH TOWARDS THURSDAY AFTERNOON.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 427 AM CST WED DEC 23 2015
THURSDAY NIGHT AND FRIDAY LOOK TO BE A QUIET LULL IN BETWEEN
SYSTEMS. THE MAIN QUESTION DURING THIS PERIOD WILL BE WHAT THE
CLOUD COVER DOES...AND ITS EFFECT ON TEMPERATURES. THE TREND THIS
TIME OF YEAR IS THAT UNLESS WE HAVE STRONG COLD DRY ADVECTION THAT
THOROUGHLY MIX OUT THE STRATUS...WE ARE LIKELY TO REMAIN STUCK IN
THE STRATUS IN BETWEEN THE SYSTEMS. SO...HAVE STAYED WITH A
CLOUDIER SOLUTION FOR NOW WITH NO GOOD STRONG PUSH TO GET RID OF THE
STRATUS AND HAVE STAYED WITH MODERATED TEMPERATURES THROUGHOUT.
HOWEVER...IF IT LOOKS LIKE WE MIGHT ACTUALLY CLEAR OUT AFTER
ALL...MY TEMPS ARE NOT COLD ENOUGH ALL AROUND. AS A FOOT
NOTE...HAVE NOTICED THE NAM RUNNING A WEAK FAST MOVING SHORTWAVE
ACROSS PARTS OF THE FORECAST AREA THURSDAY NIGHT...BUT IT IS THE
ONLY MODEL DOING THAT FOR NOW AND WHILE THE PREVIOUS RUNS HAVE
IT...THE TRACK HAS BEEN DRIFTING ABOUT AND REMAINS QUITE WEAK AND
MOSTLY SOUTH OF THE FORECAST AREA. SO...HAVE LEFT IT OUT FOR NOW.
THE NEXT SIGNIFICANT STORM MOVES THROUGH THE FORECAST AREA BEGINNING
FRIDAY NIGHT...AND CONTINUING SATURDAY BEFORE ENDING SATURDAY NIGHT
OR EARLY SUNDAY DEPENDING HOW MUCH LAKE EFFECT SNOW DEVELOPS. THE
MODELS ARE FAIRLY CONSISTENT IN BRINGING AN INVERTED SURFACE TROUGH
ACROSS THE FORECAST AREA DURING THE DAY ON SATURDAY...ASSOCIATED
WITH AN 850MB LOW THAT TRACKS FROM SE SD...EAST-NORTHEAST TO EASTERN
UPPER MICHIGAN DURING THE DAY ON SATURDAY. FOR NOW THIS KEEPS THE
FORECAST AREA IN BELOW ZERO TEMPERATURES ALOFT AND OUR PRECIPITATION
TYPE ALL SNOW...WITH NEAR TO A LITTLE HIGHER THAN NORMAL SNOW WATER
RATIOS FOR DECEMBER. MY INITIAL THOUGHTS BRING A SOLID 2 TO 4
INCHES ACROSS THE FORECAST AREA DURING THE EVENT...BUT WILL HAVE TO
WAIT AND SEE HOW THIS ONE DEVELOPS.
IT LOOKS LIKE ANOTHER STORM SYSTEM IS GOING TO MOVE ACROSS THE
MIDWEST ON MONDAY THROUGH TUESDAY...BRINGING ANOTHER CHANCE FOR
PRECIPITATION TO THE REGION. HOWEVER...THE LATEST MODELS ARE
KEEPING THIS SYSTEM MAINLY SOUTH OF THE FORECAST AREA AND HAVE PUT
IN LOWER POPS THAN WHAT WE PREVIOUSLY HAD TO TREND TOWARDS A DRIER
FORECAST. WILL HAVE TO SEE IF THIS TREND CONTINUES BEFORE REMOVING
THEM COMPLETELY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1144 PM CST TUE DEC 22 2015
A MIX OF MVFR/VFR AT THE BEGINNING OF THE FORECAST AS DRIER AIR
HAS ERODED SOME OF THE LOWER CIGS. NEXT ROUND OF PCPN WILL AFFECT
PRIMARILY DLH AND HYR ABOUT 15Z. WITH THE WARM TEMPS IN
PLACE...EXPECT LIGHT RAIN. THIS WILL CONTINUE UNTIL 00Z WHEN
COLDER AIR BEGINS TO CHANGE THE RAIN OVER TO SNOW. CIGS WILL DROP
BACK INTO THE IFR/LOW END MVFR RANGE WITH THE PCPN.
ELSEWHERE...THE MVFR CIGS PREVAIL WITH SOME FLURRIES AFTER 21Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 34 20 24 15 / 80 60 10 10
INL 33 21 23 11 / 20 50 30 10
BRD 33 18 24 15 / 20 20 10 0
HYR 36 23 28 15 / 100 80 20 10
ASX 36 27 29 20 / 100 70 20 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR WIZ001>003-006>008.
MN...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LSZ140-141.
&&
$$
SHORT TERM...JJM
LONG TERM...LE
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1144 PM CST TUE DEC 22 2015
.UPDATE...
ISSUED AT 902 PM CST TUE DEC 22 2015
MINIMUM TEMPERATURE FORECAST HAS BEEN MET AND TEMPS CONTINUE TO
WARM. HAVE ADJUSTED THE FORECAST TO ACCOUNT FOR SLOWLY RISING
TEMPS TONIGHT. WITH THE WARM TEMPS TO START WEDNESDAY...WITH
SEVERAL SPOTS ABOVE FREEZING...REMOVED THE MENTION OF FREEZING
DRIZZLE AND SLEET.
UPDATE ISSUED AT 746 PM CST TUE DEC 22 2015
SFC LOW CENTER HAS MOVED INTO SE ND AND THE LIGHT SNOW HAS ENDED.
SFC TEMPS HAVE WARMED TO 32F OR WARMER IN SEVERAL SPOTS. AS A
RESULT...HAVE REMOVED THE MENTION OF FREEZING
DRIZZLE...SLEET...DRIZZLE. STILL EXPECTING THE NEXT ROUND OF SNOW
TO DEVELOP IN NW WI AFTER MIDNIGHT. HOWEVER...SHORT TERM HIRES
MODELS INCLUDING THE DLH WRF AND HRRR ARE POINTING TO THE
POSSIBILITY OF ALL RAIN IN NW WI OR A RAIN SNOW MIX. WILL KEEP THE
PREDOMINATE PTYPE AS SNOW. MADE SOME OTHER MINOR ADJUSTMENTS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 413 PM CST TUE DEC 22 2015
THIS AFTERNOON A COMPACT SHORTWAVE TROF STRETCHED FROM NORTHEAST
MONTANA INTO EASTERN SOUTH DAKOTA. THE TROF WAS ACCOMPANIED BY A
POTENT CYCLONIC VORTICITY ANOMALY AND STRONG WARM AIR ADVECTION.
AT THE SURFACE A CLOSE LOW WAS CENTERED OVER NORTHERN SOUTH DAKOTA
WITH A TROF OF LOW PRESSURE STRETCHING NORTHEASTWARD INTO
NORTHWEST ONTARIO. LIGHT...TO OCCASIONALLY MODERATE...SNOW WAS
FALLING OVER EASTERN NORTH DAKOTA AND NORTHWEST MINNESOTA. SNOW
SHOWERS AND AREAS OF FREEZING DRIZZLE STRETCHED FARTHER EASTWARD
INTO NORTHEAST MINNESOTA.
THE SHORTWAVE TROF AND ASSOCIATED SURFACE LOW WILL LIFT THROUGH
NORTHWEST MINNESOTA AND INTO ONTARIO TONIGHT. PATCHY AREAS OF
FREEZING DRIZZLE ARE EXPECTED TO CONTINUE OVER MUCH OF NORTHEAST
MINNESOTA THANKS IN LARGE PART TO A WEDGE OF DRY AIR BETWEEN THE
GLACIATED CLOUDS ALOFT AND THE SATURATED NEAR-SURFACE LAYER. THE
FREEZING DRIZZLE WILL CHANGE TO OR MIX WITH LIGHT SNOW OVER MY
WESTERN ZONES AS THE SYSTEM PASSES BY. SNOW ACCUMULATION SHOULD
BE LIGHT...AS THE BEST FORCING FOR ASCENT WILL QUICKLY MOVE
THROUGH ANY SPECIFIC LOCATION. LOOK FOR SNOW TOTALS IN THE DUSTING
TO 2 INCH RANGE...WITH THE HIGHEST ACCUMULATION OVER WESTERN
PORTIONS OF KOOCHICHING COUNTY.
ATTENTION THEN SHIFTS TO WEDNESDAY...AS A SECONDARY AREA OF LOW
PRESSURE LIFTS FROM THE CENTRAL PLAINS INTO NORTHERN WISCONSIN BY
LATE WEDNESDAY AFTERNOON. DETERMINISTIC AND ENSEMBLE GUIDANCE IS
ALL POINTING TOWARD STRONG WARM AIR ADVECTION AHEAD OF AND EAST OF
THE LOW...AND SURFACE TEMPERATURES OVER WISCONSIN CLIMBING INTO
THE UPPER 30S TO LOW 40S. WITH THE WARM ADVECTION AND ISENTROPIC
ASCENT...AND ASSOCIATED PRECIPITATION... AM CONCERNED GUIDANCE MAY
BE TRENDING TOO WARM WITH SFC TEMPS. HAVE TRENDED CLOSER TO THE
DETERMINISTIC NAM GUIDANCE FOR TEMPS ON WEDNESDAY...WHICH YIELDS
30-35F FOR MAX TEMPS.
PRECIP TYPES ARE A CHALLENGE FOR WEDNESDAY. THE AIRMASS WILL BE
COLD ENOUGH FOR SNOW...WITH PATCHY FREEZING DRIZZLE...OVER MY
MINNESOTA ZONES. HOWEVER...ASCENT IS MUCH WEAKER AND DO NOT EXPECT
MORE THAN FLURRIES AND FREEZING DRIZZLE THROUGH THE AFTERNOON.
WHERE PRECIPITATION IS LIKELY TO BE HEAVIEST...MAINLY FROM THE
TWIN PORTS SOUTH ALONG I-35 AND EASTWARD...A WINTRY MIX OF SNOW...
SLEET...AND RAIN SEEMS FAVORED. SHOULD TEMPERATURES REMAIN
COOLER...AND IF THE ADVECTION ALOFT TRENDS CLOSER TO THE GFS
SOLUTION...FREEZING RAIN WOULD BE MORE OF A CONCERN. BETWEEN THE
SLEET AND SNOW POTENTIAL...THERE IS A THREAT FOR SOME ICY ROADS.
DUE TO THE LINGERING UNCERTAINTY IN PTYPE AND TEMPERATURES...HELD
OFF ON AN ADVISORY FOR NOW BUT ONE MAY BE NEEDED BY MORNING.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 413 PM CST TUE DEC 22 2015
BY WEDNESDAY EVENING THE SFC LOW WILL BE RACING OFF TO THE
NORTHEAST...AND ITS WHEREABOUTS DEPEND UPON THE MODEL AND HAVE
USED THE GFS/ECMWF COMPROMISE OF THE SLOWER MOVEMENT. THE
CYCLONIC FLOW AROUND THE LOW WILL KEEP SNOW SHOWERS GOING INTO
THURSDAY MORNING. THEY WILL END IN THE AFTERNOON. HOWEVER...THERE
COULD BE SOME ISOLATED LAKE EFFECT SNOW SHOWERS ALONG THE SOUTH
SHORE AS 8H TEMPS OF -8C TO -10C BLOW ACROSS A +5C LAKE SUPERIOR.
HOWEVER...A WEST COMPONENT DOES NOT GIVE A VERY LONG FETCH AND IF
ANY SNOW SHOWERS DO OCCUR...THEY WILL BE ISOLATED AND LIGHT.
BROAD UPPER LEVEL TROFINESS WILL DOMINATE THE FLOW THROUGH THE
EXTENDED PERIOD. THIS WILL KEEP THE NORTHLAND IN A MILD SOUTHWEST OR
WEST AIRFLOW. ONCE THE CURRENT LOW PRESSURE PASSES THERE WILL BE
LITTLE PRECIPITATION UNTIL ABOUT SATURDAY WHEN ANOTHER LOW WILL MOVE
NORTH INTO IOWA AND ILLINOIS. AND ANOTHER ONE MAY BRING SNOW NEXT
TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1144 PM CST TUE DEC 22 2015
A MIX OF MVFR/VFR AT THE BEGINNING OF THE FORECAST AS DRIER AIR
HAS ERODED SOME OF THE LOWER CIGS. NEXT ROUND OF PCPN WILL AFFECT
PRIMARILY DLH AND HYR ABOUT 15Z. WITH THE WARM TEMPS IN
PLACE...EXPECT LIGHT RAIN. THIS WILL CONTINUE UNTIL 00Z WHEN
COLDER AIR BEGINS TO CHANGE THE RAIN OVER TO SNOW. CIGS WILL DROP
BACK INTO THE IFR/LOW END MVFR RANGE WITH THE PCPN.
ELSEWHERE...THE MVFR CIGS PREVAIL WITH SOME FLURRIES AFTER 21Z.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 30 34 22 25 / 30 70 30 10
INL 30 33 18 22 / 10 20 30 20
BRD 30 33 19 24 / 10 20 20 10
HYR 32 36 24 28 / 70 100 50 10
ASX 32 37 27 30 / 50 90 60 20
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 6 AM CST WEDNESDAY FOR LSZ140-141.
&&
$$
UPDATE...GSF
SHORT TERM...HUYCK
LONG TERM...CLC
AVIATION...GSF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
829 PM CST THU DEC 24 2015
.UPDATE...CONVECTION CURRENTLY OVER SE ABOUT TO COMPLETELY SHIFT EAST
INTO AL. FOCUS WILL THEN SHIFT TO THE NW WHERE HRRR IS INDICATING
CONSIDERABLE DEVELOPMENT AFTER MIDNIGHT. FORECAST LOOKS ON TRACK FOR
THE REMAINDER OF THE NIGHT./26/
&&
.AVIATION...MVFR/IFR CIGS AND VSBYS ARE EXPECTED TONIGHT WITH
CONDITIONS WORSENING INTO THE OVERNIGHT HOURS. LIFR CONDITIONS WILL
BE MOST LIKELY AT MEI AND HBG AFTER 10Z...SLOWLY IMPROVING AFTER 15Z.
SCATTERED TO NUMEROUS SHRA AND TSRA WILL CONTINUE TO MOVE IN AND OUT
OF THE TAF SITES THROUGH THE PERIOD...SERVING TO BRIEFLY LOWER VSBYS
AND CIGS./26/
&&
.PREV DISCUSSION... /ISSUED 455 PM CST THU DEC 24 2015/
DISCUSSION... DEALING WITH A POTENT LEFT-MOVING SUPERCELL COMING UP
THROUGH THE JACKSON METRO RIGHT AT THE MOMENT...AND THE PRESENCE OF
THIS STORM BRINGS TO LIGHT THE VOLATILE COMBINATION OF INSTABILITY
AND WIND SHEAR CURRENTLY IN PLACE ACROSS THE REGION. THINKING IS
THAT A STORM OF THIS STRENGTH SHOULD NOT BE THE RULE THROUGH THE
NEXT 24 HOURS...BUT SOME ADDITIONAL SEVERE STORMS WILL STILL BE
POSSIBLE (MAINLY THROUGH THIS EVENING IN CENTRAL AND SOUTHERN ZONES
AND THEN LATER TONIGHT THROUGH TOMORROW IN NORTHERN ZONES). ACTIVITY
THROUGH MOST OF TODAY HAS BEEN TRAINING ACROSS SOUTHEASTERN MS NEAR
A STALLED MOISTURE ADVECTION BOUNDARY...BUT NOW THE BACKING OF LOW
LEVEL FLOW IS STARTING THE TRANSITION WHICH SHOULD CULMINATE LATER
TONIGHT IN TRAINING SHOWERS AND STORMS ACROSS NORTHERN ZONES (AND
ESPECIALLY THE ARKLAMISS DELTA). OF COURSE WHERE STORMS START TO
TRAIN THE ANOMALOUSLY-HIGH MOISTURE CONTENT OF THE AIR MASS WILL
LEND TO INCREASED FLOODING POTENTIAL...AND THIS WAS MENTIONED IN THE
HWO.
REGARDING THE SEVERE WEATHER ENVIRONMENT...THE ATMOSPHERE IS NOT SET
UP WELL TO PRODUCE TORNADOES BECAUSE NEEDED LOW LEVEL HELICITY IS
MARGINAL AT BEST. THAT SAID...THERE IS ENOUGH DEEP LAYER SHEAR AND
INSTABILITY TO SPAWN SUPERCELLS AND IT IS HARD TO COMPLETELY RULE
OUT TORNADO PRODUCTION WITH ANY SUPERCELLS TAPPING INTO SURFACE-
BASED INSTABILITY. GIVEN THAT ASSESSMENT WE WILL FOCUS ON WIND AND
HAIL RISKS IN THE HWO THROUGH TOMORROW WHILE ALSO MENTIONING
LOCALIZED FLASH FLOOD POTENTIAL.
AFTER TOMORROW THE BAROCLINIC ZONE FOCUSING CONVECTION IN THE SHORT
TERM SHOULD SET UP FURTHER TO THE NORTHEAST FOR SATURDAY INTO MIDDAY
SUNDAY....WHICH SHOULD ALLOW OUR REGION TO CONTINUE TO BE VERY WARM
WITH MUCH SMALLER POPS AND RISKS OF STORMS THROUGH THAT TIME PERIOD.
BUT BY LATER SUNDAY MODEL CONSENSUS IS COMING AROUND TO THE IDEA OF
A FRONT PRODUCING SHOWERS AND SOME STORMS OOZING INTO THE ARKLAMISS
DELTA. THIS WILL JUST PROCEED A POTENT LOOKING SOUTHERN STREAM
DISTURBANCE SET TO PLOW THROUGH THE REGION LATE SUNDAY NIGHT THROUGH
MIDDAY TO EARLY AFTERNOON MONDAY. OF COURSE WITH ALL THE WARMTH AND
INSTABILITY EXPECTED TO BE IN PLACE AND NEARBY BAROCLINITY IN
ADVANCE OF THE DISTURBANCE...ANTICIPATE IMPRESSIVE LIFT AND
THUNDERSTORM PRODUCTION WITH THE SYSTEM PASSAGE. CONFIDENCE IN
SEVERE STORMS IS CURRENTLY BEST IN WESTERN ZONES BECAUSE THERE IS
SOME POTENTIAL THE DYNAMICS OF SYSTEMS COULD WEAKEN AS IT
TRANSITIONS THROUGH THE AREA. FOR THAT REASON WE INTRODUCED SEVERE
RISK IN THE HWO FOR WESTERN AREAS WITH THIS PACKAGE ALTHOUGH MAY
WELL HAVE TO EXPAND COVERAGE WITH LATER OUTLOOKS. FORTUNATELY...THE
SYSTEM AND ITS STORMS LOOK TO PASS THROUGH QUICKLY SO THE ADDITIONAL
HEAVY RAINFALL THREAT WILL NOT BE AS HIGH AS IT COULD OTHERWISE BE.
/BB/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 69 80 68 80 / 42 45 37 20
MERIDIAN 69 79 68 78 / 66 37 27 24
VICKSBURG 70 79 66 81 / 41 54 47 20
HATTIESBURG 69 81 68 79 / 52 31 22 25
NATCHEZ 71 79 69 80 / 35 42 35 18
GREENVILLE 66 75 66 79 / 70 76 60 31
GREENWOOD 68 77 68 80 / 60 78 54 27
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
632 PM CST THU DEC 24 2015
.SHORT TERM: (Through Late Tonight)
Issued at 342 PM CST Thu Dec 24 2015
Low-mid level WAA and MCON along with frontogenetic forcing resulted
in an elongated region of light rain earlier today across central
and northeast MO. This regime is occurring in advance of a low-
amplitude disturbance which is dampening and now located in western
MO. Overall forcing has diminished and shifted to the northeast of
the CWA and only a narrow elongated ribbon of light rain still
persists in west central IL. Present indications is this will also
diminish and shift to the northeast the remainder of the afternoon
and early evening as the disturbance aloft and associated surface
cold front push east. There are some indications in the HRRR and GFS
that a new narrow band of precipitation may try to develop this
evening somewhere in the SE/EC MO into SW IL region in response to a
new region of low level MCON. I have add a slight chance of light
rain in SW IL this evening to account for this and some sprinkles
further west. Otherwise expecting several waves of clouds tonight
with current mid clouds and maybe a period of low clouds up north.
SREF probs and HRRR also suggesting some potential for fog from
across northern/central MO into western IL overnight. I added a
mention of patchy fog in this region, but the overall pattern in
post-frontal air mass with building surface high pressure is at
first glance not one typically associated with a lot of fog.
Glass
.LONG TERM: (Friday through Next Thursday)
Issued at 342 PM CST Thu Dec 24 2015
(Friday)
Overall, it looks like a fairly tranquil Christmas Day across the
area. Models continue to hint at WAA along the stalled frontal
boundary to our south generating an axis of convection from AR into
the lower Ohio Valley, with our far southern counties on the very
northern fringes of this activity. The 12z solutions have the axis
of this activity just south of our area, but since the last few
model cycles have wobbled a bit with the north/south placement of
this precip, I`ve maintained some very low PoPs over our far
southern counties.
Otherwise, it still appears tranquil conditions are on tap for the
region, with temperatures maintaining the very mild levels that have
been commonplace this December. Highs are expected to range from
the middle and upper 40s northwest, to the middle 50s southeast.
Concern then turns to the long-advertised heavy rain threat for the
upcoming weekend and into early next week. Due to some uncertainty
to the placement of the heaviest rain have opted not to go with any
hydro headlines...yet. However, will be reissuing the EFP to
maintain awareness of the threat, which should come in two waves as
described below.
(Saturday Through Monday Night)
The long-advertised spell of wet weather should commence in earnest
either late Friday night or Saturday. Deep southerly flow is
expected to develop across the region in response to the upper level
system digging into the southwest US, and resultant isentropic
ascent over the area should be quite strong with the stalled frontal
boundary and low level baroclinic zone just to our south. In
addition, UVV across the area will be enhance by several weak
shortwaves ejecting ahead of the main system. Moisture should be no
problem as airmass will essentially be the same one that fueled
yesterdays storms in our area, with the increasing southerly flow
adding even more moisture to the unseasonably moist December
airmass. Again, models are wobbling a bit with the exact location of
the axis of the heaviest precip, but they are in excellent agreement
with the general idea that several rounds of convection will track
along and north of the frontal boundary as it attempts to push
north...from eastern OK into s MO and s IL...in the Saturday and
Saturday night time.
It appears that this first round of significant rain will wind down
on Sunday as shortwave in the northern branch of the westerlies
allows Canadian high to drop south, temporarily shutting down the
warm advection and nudging the frontal boundary back south.
Final wave of potentially heavy rain should impact the region on
Monday and Monday night as upper level low lifts out of Texas and
pushes northeast into the mid-Mississippi Valley. Again, moisture-
laden AMS ans strong UVV should produce another band of moderate to
occasionally heavy rain...with embedded thunderstorms...that will
sweep across the area.
It`s not totally out of the question that we could see a bit of
wintry precip Sunday night-Monday night. First concern will be late
Sunday night and into early Monday as surface temps drop below
freezing with the southward surge of the Canadian high...while AMS
aloft remains well above freezing. This threat should be brief and
on the northern fringes of the heavier rainfall...and with the very
warm ground temperatures am not expecting much of an impact from
this. The second concern will be Monday night as the upper low
pushes across the area. It`s possible that the dropping freezing
levels beneath the low could cause the rain to change over to snow,
but not certain if the lower levels will cool enough for any
prolonged period of significant snowfall.
(Tuesday-Thursday)
Medium range progs suggest long wave trof will be parked over the
central CONUS during this time frame. This will finally allow
Canadian air to dominate the region, which should yield more normal
typical wintertime temperatures.
Best holiday wishes to all...from the day shift of the National
Weather Service in St. Louis.
Truett
&&
.AVIATION: (For the 00z TAFs through 00z Friday Evening)
Issued at 612 PM CST Thu Dec 24 2015
Weak SFC low near NE MO as of 00Z should weaken as it tracks NE
this evng. This feature will allow a weak cold front to move thru
the area tonight but should be much more than a wind shift. An
area of MVFR CIGS may graze UIN for a few hours this evng
otherwise expect VFR clouds with CIGS aoa 8 kft thru the remainder
of the prd. SFC ridge will pass to the north tomorrow allowing
winds to quickly become erly by Fri aftn. Guidance continues to
hint at fog dvlpmnt across the wrn and nthrn CWA but didn`t hit it
too hard as the synoptic set up for fog is not good. FROPA this
evng...NW breeze with drying Dps and sporadic mid/high clouds
overnight should all act to inhibit or at least limit the fog.
Specifics for KSTL:
VFR fcst thru the prd. Weak cold front will pass thru the terminal
this evng with winds bcmng NWrly tonight. High pressure is fcst to
pass well to the north thru the prd allowing winds to veer to the
east by Fri aftn. Any CIGs should be aoa 8 kft.
2%
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 39 54 47 63 / 10 10 50 100
Quincy 32 48 42 54 / 10 5 20 70
Columbia 33 52 45 59 / 5 10 60 80
Jefferson City 33 53 46 60 / 5 10 70 80
Salem 40 56 49 64 / 20 20 50 90
Farmington 39 54 49 64 / 20 20 60 100
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
125 PM CST WED DEC 23 2015
.UPDATE:
Issued at 122 PM CST Wed Dec 23 2015
In the process of issuing a wind advisory for our mid MO counties.
Passage of cold front/dry line has been accompanied by deep
mixing over southwest and west central MO with sustained winds of
25-30kts, and expecting similar conditions to spread over western
portions of our CWA as fropa occurs during the afternoon.
Otherwise, no changes to earlier thinking, and still anticipating
strong convection to fire along the cold front/dry line over the
next 1-2 hours.
Truett
&&
.SHORT TERM: (Through Tonight)
Issued at 344 AM CST Wed Dec 23 2015
Showers and thunderstorms will be on the increase this morning as
surface low and associated upper level trof continue to lift north
northeast from TX panhandle towards the western Great Lakes region
by early this evening. Forecast area to remain on warm side of
system through midday before strong cold front slides through
region. Main question is will this initial round of activity muddy
the waters for any severe convection with frontal boundary this
afternoon. Think there will be enough of break in precipitation and
clouds to see atmosphere become unstable with CAPES between 500 and
1200 J/kg as strong low level jet advects dewpts in the upper 50s to
low 60s into the region by this afternoon. Forecast soundings
continue to indicate deep layer shear, curved hodographs and this
combined with decent instability, supercell development is expected
with the main threats being tornadoes and damaging winds, though
some large hail is possible as well. The best area to see this would
be southeast MO and southwestern IL. However, latest HRRR run is
indicating some supercell development further north closer to
deepening surface low over northeast MO and west central IL. Will
have to keep an eye out on these changing conditions.
Otherwise, will see temperatures rising through midday on gusty
south winds, into the 60s, then remain steady or slowly fall as
frontal boundary slides through. Could see gusts between 35 and 40
mph at times outside of storms. Storms to taper off by early this
evening with winds veering to the west on back side of system and
diminishing.
Byrd
.LONG TERM: (Thursday through Tuesday)
Issued at 344 AM CST Wed Dec 23 2015
(Thursday through Christmas Day)
Dry weather expected for most of the area through Christmas Day with
temperatures remaining above normal, in the upper 40s to low 60s.
With stalled frontal boundary just south of forecast area, could see
some light rain for far southern portions of forecast area Christmas
Day.
(Christmas Night through Tuesday)
Frontal boundary that is stalled south of the forecast area will
move back northward Christmas night and Saturday. Will see numerous
rounds of showers and embedded thunderstorms across the region
through Monday before tapering off Monday night as associated
surface low lifts northeastward through region and into the Great
Lakes region by Monday night. At this time, models are indicating
between 3 and 6 inches of rain with locally higher amounts possible.
The axis of heaviest rain will extend from southwestern MO
through the St. Louis metro area and into central Illinois. This
will affect area rivers and streams, leading to additional
flooding. For more details, please see the hydrologic outlook
(ESF).
Byrd
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1128 AM CST Wed Dec 23 2015
Morning thunderstorms have moved rapidly east of all TAF sites.
However...another line of thunderstorms is forecast to form around
19Z near a KCOU to KUIN line and move rapidly eastward into the
KSTL metro TAF sites between 21Z and 23Z. Coverage is uncertain at
this time...so covered in 18Z TAFS with VCTS. Will update as
needed once convection forms. Some storms could produce strong
wind gusts. Behind that line...VFR conditions expected and
southwest winds will likely increase for a few hours with gusts to
near 30 kts. Winds will diminish during the evening...and veer
strongly to southeast by 12Z.
Specifics for KSTL: Morning thunderstorms have moved rapidly east
with VFR conditions remaining. However...another line of
thunderstorms is forecast to move rapidly eastward into the KSTL
metro TAF sites between 21Z and 23Z. Coverage is uncertain at this
time...so covered in 18Z TAFS with VCTS. Will update as needed
once convection forms. Some storms could produce strong wind
gusts. Behind that line...VFR conditions expected and southwest
winds will likely increase for a few hours with gusts to near 30
kts. Winds will diminish during the evening...and veer strongly to
southeast by 12Z...then back to 180 degrees by around 18Z.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Wind Advisory until 6 PM CST this evening FOR Audrain MO-Boone
MO-Callaway MO-Cole MO-Gasconade MO-Moniteau MO-Montgomery
MO-Osage MO.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
1205 PM CST WED DEC 23 2015
.UPDATE:
Issued at 1159 AM CST Wed Dec 23 2015
Current line of convection over the southeast sections of the CWA will
continue to roll east and exit the area early this afternoon, just
in time for another round of strong to potentially severe storms
to develop along the eastward pushing cold front/dry line. Clearing
ahead of the front/dry line is rapidly destabilzing the AMS, and
RAP forecasts throughout the morning have consistently been
forecasting SBCAPES of 1000-1500 J/Kg into the afternoon hours.
Truett
&&
.SHORT TERM: (Through Tonight)
Issued at 344 AM CST Wed Dec 23 2015
Showers and thunderstorms will be on the increase this morning as
surface low and associated upper level trof continue to lift north
northeast from TX panhandle towards the western Great Lakes region
by early this evening. Forecast area to remain on warm side of
system through midday before strong cold front slides through
region. Main question is will this initial round of activity muddy
the waters for any severe convection with frontal boundary this
afternoon. Think there will be enough of break in precipitation and
clouds to see atmosphere become unstable with CAPES between 500 and
1200 J/kg as strong low level jet advects dewpts in the upper 50s to
low 60s into the region by this afternoon. Forecast soundings
continue to indicate deep layer shear, curved hodographs and this
combined with decent instability, supercell development is expected
with the main threats being tornadoes and damaging winds, though
some large hail is possible as well. The best area to see this would
be southeast MO and southwestern IL. However, latest HRRR run is
indicating some supercell development further north closer to
deepening surface low over northeast MO and west central IL. Will
have to keep an eye out on these changing conditions.
Otherwise, will see temperatures rising through midday on gusty
south winds, into the 60s, then remain steady or slowly fall as
frontal boundary slides through. Could see gusts between 35 and 40
mph at times outside of storms. Storms to taper off by early this
evening with winds veering to the west on back side of system and
diminishing.
Byrd
.LONG TERM: (Thursday through Tuesday)
Issued at 344 AM CST Wed Dec 23 2015
(Thursday through Christmas Day)
Dry weather expected for most of the area through Christmas Day with
temperatures remaining above normal, in the upper 40s to low 60s.
With stalled frontal boundary just south of forecast area, could see
some light rain for far southern portions of forecast area Christmas
Day.
(Christmas Night through Tuesday)
Frontal boundary that is stalled south of the forecast area will
move back northward Christmas night and Saturday. Will see numerous
rounds of showers and embedded thunderstorms across the region
through Monday before tapering off Monday night as associated
surface low lifts northeastward through region and into the Great
Lakes region by Monday night. At this time, models are indicating
between 3 and 6 inches of rain with locally higher amounts possible.
The axis of heaviest rain will extend from southwestern MO
through the St. Louis metro area and into central Illinois. This
will affect area rivers and streams, leading to additional
flooding. For more details, please see the hydrologic outlook
(ESF).
Byrd
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1128 AM CST Wed Dec 23 2015
Morning thunderstorms have moved rapidly east of all TAF sites.
However...another line of thunderstorms is forecast to form around
19Z near a KCOU to KUIN line and move rapidly eastward into the
KSTL metro TAF sites between 21Z and 23Z. Coverage is uncertain at
this time...so covered in 18Z TAFS with VCTS. Will update as
needed once convection forms. Some storms could produce strong
wind gusts. Behind that line...VFR conditions expected and
southwest winds will likely increase for a few hours with gusts to
near 30 kts. Winds will diminish during the evening...and veer
strongly to southeast by 12Z.
Specifics for KSTL: Morning thunderstorms have moved rapidly east
with VFR conditions remaining. However...another line of
thunderstorms is forecast to move rapidly eastward into the KSTL
metro TAF sites between 21Z and 23Z. Coverage is uncertain at this
time...so covered in 18Z TAFS with VCTS. Will update as needed
once convection forms. Some storms could produce strong wind
gusts. Behind that line...VFR conditions expected and southwest
winds will likely increase for a few hours with gusts to near 30
kts. Winds will diminish during the evening...and veer strongly to
southeast by 12Z...then back to 180 degrees by around 18Z.
Browning
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 68 43 56 38 / 80 30 5 10
Quincy 65 37 47 33 / 70 30 10 5
Columbia 67 38 53 35 / 50 10 5 5
Jefferson City 69 38 55 36 / 50 10 5 10
Salem 67 45 57 40 / 100 60 5 10
Farmington 67 42 59 39 / 80 20 5 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1143 AM CST WED DEC 23 2015
.SHORT TERM: (Through Tonight)
Issued at 344 AM CST Wed Dec 23 2015
Showers and thunderstorms will be on the increase this morning as
surface low and associated upper level trof continue to lift north
northeast from TX panhandle towards the western Great Lakes region
by early this evening. Forecast area to remain on warm side of
system through midday before strong cold front slides through
region. Main question is will this initial round of activity muddy
the waters for any severe convection with frontal boundary this
afternoon. Think there will be enough of break in precipitation and
clouds to see atmosphere become unstable with CAPES between 500 and
1200 J/kg as strong low level jet advects dewpts in the upper 50s to
low 60s into the region by this afternoon. Forecast soundings
continue to indicate deep layer shear, curved hodographs and this
combined with decent instability, supercell development is expected
with the main threats being tornadoes and damaging winds, though
some large hail is possible as well. The best area to see this would
be southeast MO and southwestern IL. However, latest HRRR run is
indicating some supercell development further north closer to
deepening surface low over northeast MO and west central IL. Will
have to keep an eye out on these changing conditions.
Otherwise, will see temperatures rising through midday on gusty
south winds, into the 60s, then remain steady or slowly fall as
frontal boundary slides through. Could see gusts between 35 and 40
mph at times outside of storms. Storms to taper off by early this
evening with winds veering to the west on back side of system and
diminishing.
Byrd
.LONG TERM: (Thursday through Tuesday)
Issued at 344 AM CST Wed Dec 23 2015
(Thursday through Christmas Day)
Dry weather expected for most of the area through Christmas Day with
temperatures remaining above normal, in the upper 40s to low 60s.
With stalled frontal boundary just south of forecast area, could see
some light rain for far southern portions of forecast area Christmas
Day.
(Christmas Night through Tuesday)
Frontal boundary that is stalled south of the forecast area will
move back northward Christmas night and Saturday. Will see numerous
rounds of showers and embedded thunderstorms across the region
through Monday before tapering off Monday night as associated
surface low lifts northeastward through region and into the Great
Lakes region by Monday night. At this time, models are indicating
between 3 and 6 inches of rain with locally higher amounts possible.
The axis of heaviest rain will extend from southwestern MO
through the St. Louis metro area and into central Illinois. This
will affect area rivers and streams, leading to additional
flooding. For more details, please see the hydrologic outlook
(ESF).
Byrd
&&
.AVIATION: (For the 18z TAFs through 18z Thursday Afternoon)
Issued at 1128 AM CST Wed Dec 23 2015
Morning thunderstorms have moved rapidly east of all TAF sites.
However...another line of thunderstorms is forecast to form around
19Z near a KCOU to KUIN line and move rapidly eastward into the
KSTL metro TAF sites between 21Z and 23Z. Coverage is uncertain at
this time...so covered in 18Z TAFS with VCTS. Will update as
needed once convection forms. Some storms could produce strong
wind gusts. Behind that line...VFR conditions expected and
southwest winds will likely increase for a few hours with gusts to
near 30 kts. Winds will diminish during the evening...and veer
strongly to southeast by 12Z.
Specifics for KSTL: Morning thunderstorms have moved rapidly east
with VFR conditions remaining. However...another line of
thunderstorms is forecast to move rapidly eastward into the KSTL
metro TAF sites between 21Z and 23Z. Coverage is uncertain at this
time...so covered in 18Z TAFS with VCTS. Will update as needed
once convection forms. Some storms could produce strong wind
gusts. Behind that line...VFR conditions expected and southwest
winds will likely increase for a few hours with gusts to near 30
kts. Winds will diminish during the evening...and veer strongly to
southeast by 12Z...then back to 180 degrees by around 18Z.
Browning
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 68 43 56 38 / 80 30 5 10
Quincy 64 37 47 33 / 80 30 10 5
Columbia 67 38 53 35 / 50 10 5 5
Jefferson City 69 38 55 36 / 50 10 5 10
Salem 67 45 57 40 / 100 60 5 10
Farmington 67 42 59 39 / 80 20 5 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
350 AM CST WED DEC 23 2015
.SHORT TERM: (Through Tonight)
Issued at 344 AM CST Wed Dec 23 2015
Showers and thunderstorms will be on the increase this morning as
surface low and associated upper level trof continue to lift north
northeast from TX panhandle towards the western Great Lakes region
by early this evening. Forecast area to remain on warm side of
system through midday before strong cold front slides through
region. Main question is will this initial round of activity muddy
the waters for any severe convection with frontal boundary this
afternoon. Think there will be enough of break in precipitation and
clouds to see atmosphere become unstable with CAPES between 500 and
1200 J/kg as strong low level jet advects dewpts in the upper 50s to
low 60s into the region by this afternoon. Forecast soundings
continue to indicate deep layer shear, curved hodographs and this
combined with decent instability, supercell development is expected
with the main threats being tornadoes and damaging winds, though
some large hail is possible as well. The best area to see this would
be southeast MO and southwestern IL. However, latest HRRR run is
indicating some supercell development further north closer to
deepening surface low over northeast MO and west central IL. Will
have to keep an eye out on these changing conditions.
Otherwise, will see temperatures rising through midday on gusty
south winds, into the 60s, then remain steady or slowly fall as
frontal boundary slides through. Could see gusts between 35 and 40
mph at times outside of storms. Storms to taper off by early this
evening with winds veering to the west on back side of system and
diminishing.
Byrd
.LONG TERM: (Thursday through Tuesday)
Issued at 344 AM CST Wed Dec 23 2015
(Thursday through Christmas Day)
Dry weather expected for most of the area through Christmas Day with
temperatures remaining above normal, in the upper 40s to low 60s.
With stalled frontal boundary just south of forecast area, could see
some light rain for far southern portions of forecast area Christmas
Day.
(Christmas Night through Tuesday)
Frontal boundary that is stalled south of the forecast area will
move back northward Christmas night and Saturday. Will see numerous
rounds of showers and embedded thunderstorms across the region
through Monday before tapering off Monday night as associated
surface low lifts northeastward through region and into the Great
Lakes region by Monday night. At this time, models are indicating
between 3 and 6 inches of rain with locally higher amounts possible.
The axis of heaviest rain will extend from southwestern MO
through the St. Louis metro area and into central Illinois. This
will affect area rivers and streams, leading to additional
flooding. For more details, please see the hydrologic outlook
(ESF).
Byrd
&&
.AVIATION: (For the 06z TAFs through 06z Wednesday Night)
Issued at 1142 PM CST Tue Dec 22 2015
Predominantly IFR CIGs should continue to push NW overnight and
expand to affect the remainder of the TAF sites. IFR VSBYs have
advanced to the edge of STL metro and CPS, but seem to have slowed
down as of late and still debatable whether they will expand into
STL, SUS, and UIN. With this issuance have added to STL TAF but
left out of the others. These clouds will prevail until low level
steering winds develop a westerly component to them Wednesday
morning and should see improvement to them into MVFR.
A low level jet of 45-50kts is currently over the area and will
continue into Wednesday morning. With the strong inversion in
place, maintained the LLWS mention.
Showers and a few TSRA will rapidly expand into the area towards
daybreak. Added VCTS to all sites with increasing signals and
probs for thunder. This should last for 3-4 hours.
A new round of SHRA/TSRA will try to develop later in the
afternoon Wednesday but relatively high uncertainty remains on
coverage which looks sparse on the latest models. Have added VCTS
for now with a small temporal window of 2 hours.
TES
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 68 43 56 38 / 90 30 5 10
Quincy 64 37 47 33 / 90 30 10 5
Columbia 67 38 53 35 / 90 10 5 5
Jefferson City 69 38 55 36 / 90 10 5 10
Salem 67 45 57 40 / 100 60 5 10
Farmington 67 42 59 39 / 90 20 5 10
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1142 PM CST TUE DEC 22 2015
.UPDATE:
Issued at 927 PM CST Tue Dec 22 2015
A few adjustments to the forecast tonight...mainly to try and time
clouds a little better and to reflect precip trends shown by the
latest short range guidance. Both the RAP and HRRR are delaying
the onset of precipitation until after 10-11Z across much of the
area, so have cut back the PoPs a bit...keeping likelies out of
the forecast until 11-12Z, and then only in far southern zones and
northwest zones where guidance is showing accumulating precip.
Quickly ramp up to likely and categorical after 12Z.
Of second concern, watching fog inch toward our southeast CWFA
border. Will continue to monitor, but I may have to issue a dense
fog advisory before midnight if the fog continues to spread
northeast.
Carney
&&
.SHORT TERM: (Through Late Tonight)
Issued at 332 PM CST Tue Dec 22 2015
Over the last few hour the low stratus has eroded rapidly in most of
the MO counties in our CWA. However, some lower clouds are
lingering over our s IL counties, with another, more persistent and
thicker cloud deck remaining anchored in the post frontal AMS from
se MO into the Ohio Valley. With a s/se component to the low level
flow continuing overnight believe that lower clouds will expand
across the eastern half of the CWA during the evening through a
combination of redevelopment with noctural cooling of the boundary
layer and/or nwd advection of Ohio Valley cloud deck. Over central
MO, the higher level cloudiness of this evening should also give way
to lower clouds after midnight as increasing southerly flow/low
level jet causes low level moisture to surge into the area.
The resultant moisture transport and isentropic ascent, combined
with larger scale UVV associated with lead shortwave ejecting ahead
of central Plains trof, should allow showers to develop after 06z in
a N/S band west of the Mississippi River that will gradually
increase in coverage and expand east with time. Although forecast
instability looks fairly meager the low level advection profile does
lead to decent lower/mid level lapse rates that would support the
idea of some elevated convection. For now I`ve maintained slight
chance of thunderstorms because of this, but evening shift will
certainly have to monitor this.
Temperatures may dip briefly this evening, before the combo of
increasing winds and clouds cause steady or slowly rising temps
during the overnight hours.
Truett
.LONG TERM: (Wednesday through Next Tuesday)
Issued at 332 PM CST Tue Dec 22 2015
(Wednesday)
Very active and unsettled weather on Wednesday as sfc low deepends
across eastern Kansas early Wednesday morning and tracks toward
southern Iowa by midday. Expect north/south oriented band of rain
showers w/ embedded thunderstorms to sweep through the area. Should
be a break during the late morning hours/early afternoon before at
least scattered thunderstorms develop along the trailing cold front.
Threat of severe thunderstorms has increased over the past 24-48
hours due to higher forecast instability. NWP guidance suggests
SBCAPE values of 500-1000+ J/kg as a break in the rainfall and
possible breaks in the clouds would help to increase the
instability...potentially even further than what is currently being
advertised. Deep-layer shear of 50-70 knots combined with the
forecast instability would be more than enough to support all forms
of severe weather. Supercells are also quite possible along/ahead of
front as deep-layer shear vector is oriented roughly 30 degrees to
cold front. Tornado threat is increased due to very high 0-1km shear
and helicity...but south/southwest sfc winds and relatively high
LCL values could be inhibiting factors to tornadic development.
(Thursday through Christmas Day)
A relatively quiet quiet period will come between Thursday and
Christmas Day. Mostly dry weaher is expected with the exception
being Christmas Day acrosss the southeastern portion of the CWA with
a chance of showers as warm advection increases at lower levels.
Temperatures both day/night will be cooler than Wednesday...but
still well above normal levels for the end of December.
(Christmas Night through Monday)
Frontal boundary that had stalled south of the CWA will move back
northward Christmas night and Saturday and bring a round of showers
and embedded thunderstorms to the region. The retreating warm front
is then forecast to stall out somewhere across the CWA and provide
the focus for widespread showers/thunderstorms through Saturday
night with moderate to potentially heavy rainfall rates. Frontal
boundary will sag back southward by Sunday morning. Temperatures
will cool and instability...even aloft...becomes negligible. Have
removed thunder wording for the Sunday period but still have
likely/categorical PoPs north of the boundary for light/moderate
rain. Sunday looks like a real chilly/raw day with high temperatures
foercast to be only in the 40s with northeast winds and rain. Sfc
system will occlude near the Arklatex region late on Sunday and
track toward north-central Missouri by Monday afternoon. Another
round of moderate to potentially heavy rainfall is likely to occur
late Sunday night/early Monday along with embedded thunderstorms
also possible. An early look at total rainfall for this event looks
to be on the order of 3 to 6 inches across the southeastern half of
the CWA...with locally higher amounts possible due to convection.
This rainfall will likely lead to additional flooding along area
rivers/streams. For more details...please see the hydrologic outlook
(ESF).
(Tuesday)
The atmosphere looks to finally quiet down next Tuesday as the
previous system moves out into southeastern Canada. Temepratures
will remain above normal on Tuesday with highs in the 40s. Some
signs of a pattern shift heading toward the New Year as longwave
ridging builds near the west coast. If this indeed occurs...at
turn toward near or below normal temperatures and drier conditions
would be more likely.
Gosselin
&&
.AVIATION: (For the 06z TAFs through 06z Wednesday Night)
Issued at 1142 PM CST Tue Dec 22 2015
Predominantly IFR CIGs should continue to push NW overnight and
expand to affect the remainder of the TAF sites. IFR VSBYs have
advanced to the edge of STL metro and CPS, but seem to have slowed
down as of late and still debatable whether they will expand into
STL, SUS, and UIN. With this issuance have added to STL TAF but
left out of the others. These clouds will prevail until low level
steering winds develop a westerly component to them Wednesday
morning and should see improvement to them into MVFR.
A low level jet of 45-50kts is currently over the area and will
continue into Wednesday morning. With the strong inversion in
place, maintained the LLWS mention.
Showers and a few TSRA will rapidly expand into the area towards
daybreak. Added VCTS to all sites with increasing signals and
probs for thunder. This should last for 3-4 hours.
A new round of SHRA/TSRA will try to develop later in the
afternoon Wednesday but relatively high uncertainty remains on
coverage which looks sparse on the latest models. Have added VCTS
for now with a small temporal window of 2 hours.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
1137 PM CST TUE DEC 22 2015
.UPDATE...
Issued at 935 PM CST TUE DEC 22 2015
Have made some adjustments to the overnight as well as Wednesday`s
PoPs. This will be most noticeable over the west central and northern
CWA. Satellite imagery shows a shortwave trough lifting northeast
from the eastern TX Panhandle/northwest TX area with a vorticity max
near CDS. Expect scattered elevated showers to form ahead of this
feature after 06z once a narrow tongue of h8 moisture is lifted into
the region via isentropic ascent on the 295K surface. Have followed
the HRRR trend of the past 3-4 runs which is supported quite well by
the 00z NAM as well as the 18z runs of the NAM and GFS. Think we`ll
see showers break out across northwest MO first with a southward
development into the KC area. Will probably see some scattered
elevated showers also pop up well downstream across northeast MO.
Using the above models as a guide believe the deeper moisture
represented by the h7 condensation pressure deficits will be swept
northeast rather quickly and by 15zish Wednesday the more widespread
showers will have lifted out of west central and north central MO.
The deformation band of more stratiform rain now looks like it will
linger over northwest MO well into the afternoon hours.
Have also adjusted overnight temperatures to reflect a steady as she
goes to a slight upward drift.....at least until the rain forms.
&&
.DISCUSSION...
Issued at 345 PM CST TUE DEC 22 2015
Big picture today shows the Nation dominated by a large trough who`s
axis resides across the Western Plains. The local result is a
southwest flow across the Lower Missouri River Valley which has
helped keep the cooler winter air out of our section of the Central
Plains. So, despite that fact that it was cloudy and cold this
morning, along with it being late December, we have warmed into the
40s and 50s again across the region with the help of the southeast
surface wind. Tonight, a shortwave trough, swinging through the base
of the mean longwave trough, will lift across the Central and
Northern Plains late tonight and Wednesday. Resulting warm air
advection ahead of the shortwave will kick in late tonight and
persist through much of Wednesday morning. Currently, models
advertise the rain to move to our northeast by noon Wednesday, but
showers and isolated thunderstorms may linger into the afternoon,
especially as you look farther east across Missouri. None of tonight
or Wednesday weather is expected to be severe, and rainfall totals
Wednesday are only expected to be around a few tenths at most.
For Thursday into Christmas Day...locally, across far eastern Kansas
and the northern half of Missouri, we expect it to be dry, but there
is a none-zero chance that a little precipitation might occur.
Thursday a secondary shortwave trough will follow the larger
Wednesday shortwave trough northeast across the Plains. Most models
have been keen to focus on this quick secondary shortwaves potential
to squeeze some light precipitation out. Have kept slight chance
POPs in across far northern reaches of the forecast area through
Wednesday night into Thursday; and depending on temperatures at that
time, some snow might develop. And, for Christmas Day, while it
could be overcast day, currently it looks like the daylight hours
will be dry locally, but we will be watching for rain to spread
north from southern Missouri that night, with rain persisting
through the weekend.
The weather Christmas Night, and through the weekend, is going to be
a bit of mess. Thursday and Friday we don`t have much chance of
getting wet as we are between storm inducing shortwave troughs, but
by Friday a large amplification in the flow is expected as a strong
shortwave trough digs deep into the mean CONUS trough across the
western CONUS, eventually developing a closed low over the Desert
Southwest which will slowly amble northeast across the Plains late
this weekend into next work week. ECMWF and GFS solutions have all
been pointing at this, though specifics on where the low goes and
how quickly it gets there have been all over the place, with the
ECMWF slowing and then speeding the low up significantly over the
past two model runs. For early in the event, Christmas Night into
Saturday, we will be well ahead of the closed low which will help
keep our temperatures benign for late December with high in the 40s
and 50s still possible Saturday. This means any precipitation early
on will be all liquid for our area. And, the amount of QPF the
models are spitting out indicates that a lot of rain will fall.
Currently, storm totals from Friday night through Monday night in
central Missouri are in the 4 to 6 inch range, tapering to between 1
and 2 inches in the far northwest corner of Missouri. As a result,
anticipate river and stream flooding will be an issue over the
weekend and into next week.
Otherwise, there will be an issue with precipitation type late in
the weekend and early next work week as the low ejects northeast
across the Plains. However, this far out in time, models are having
the typically hard time settling on a solution with the medium
range operational and ensemble models showing a fair amount of
spread in the solutions. So, with out any cold air in place across
our section of the country confidence in precipitation types late in
the weekend and next work week are very low, but have included some
snow and rain snow mix in parts of the Sunday through Monday night
periods.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1130 PM CST TUE DEC 22 2015
Radar imagery is currently depicting light echoes over eastern
Kansas, though initially, precipitation surrounding the terminal
sites will need to overcome dry air below 15 kft. Once conditions
become saturated, some light rain showers and maybe a clap or two of
thunder will affect the area in the early overnight hours. Ceiling
heights will reduce to MVFR at this time as low level moisture makes
its way into the area from the south. This activity should taper off
early Wednesday morning as mid-level winds shift to the southwest,
however, IFR ceilings will then form as temperatures cool and low-
level moisture remains over the area. Conditions will improve in the
afternoon as winds increase out of the northwest, gusting to 25-30
mph at times. VFR conditions should finish out the remainder of the
period as the surface low pushes off to the northeast.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
UPDATE...MJ
DISCUSSION...Cutter
AVIATION...Welsh
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1128 AM CST WED DEC 23 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST WED DEC 23 2015
RADAR HAS AREAS OF LIGHT RAIN MOVING THROUGH THE EASTERN PART OF THE
FORECAST AREA EARLY THIS MORNING. TEMPERATURES IN THE AREA OF RAIN
ARE WARM ENOUGH AT THIS TIME TO CONTINUE TO BE RAIN. TO THE WEST OF
THE RAIN THE TEMPERATURES HAVE STARTED TO COOL OFF.
THROUGH DAYBREAK AND INTO THE MORNING HOURS AN UPPER LEVEL LOW IS
MOVING THROUGH THE AREA. EVEN THOUGH IT IS IN THE FIRST FEW HOURS OF
THE FORECAST...THERE ARE A FEW DIFFERENCES. THE HRRR AND RAP KEEP
PRECIPITATION ONLY IN THE FAR EAST WHILE THE 4KM WRF...NAM AND GFS
PUSH THE PRECIPITATION FURTHER TO THE EAST. THE BEST CHANCE WILL
DEFINITELY BE IN THE EAST...BUT HAVE KEPT SOME LOWER POPS FURTHER TO
THE WEST. THIS BRINGS IN A PROBLEM FOR PRECIPITATION TYPE. WHILE THE
TEMPERATURES ALOFT ARE WARM ENOUGH FOR RAIN...SO IS THE SURFACE.
ONCE THE TEMPERATURES ALOFT COOL OFF THE SURFACE DOES AS
WELL...MAKING A CHANGE TO SNOW. HAVE KEPT A RAIN AND SNOW MIX IN THE
WEST/NORTHWEST THROUGH DAY BREAK AND INTO THE MORNING HOURS AS THE
PRECIPITATION IS MOVING OUT OF THE AREA. BY MID DAY THE UPPER LOW
HAS MOVED EAST AND EXPECT THAT PRECIPITATION SHOULD COME TO AN END.
THERE WILL ALSO BE SOME CLEARING AND A LITTLE SUNSHINE FOR A TIME
THIS AFTERNOON.
THE NEXT UPPER LEVEL WAVE WILL BE MOVING INTO THE AREA TONIGHT.
EXPECT PRECIPITATION TO MOVE INTO THE AREA FROM THE SOUTHWEST
TONIGHT. TEMPERATURES ARE EXPECTED TO BE COLD ENOUGH THAT EXPECT
SNOW ACROSS THE ENTIRE AREA. THE BEST CHANCE FOR ACCUMULATING SNOW
WILL BE MAINLY LATE TONIGHT. THROUGH MORNING...EXPECT THERE TO BE
LESS THAN AN INCH OR LESS OF SNOW.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 347 AM CST WED DEC 23 2015
THE MID AND LONG TERM FORECASTS CONTINUE TO BE INTERESTING AND
CHALLENGING.
CHRISTMAS EVE - CHRISTMAS NIGHT:
THERE MAY BE SOME LINGERING SNOW ACROSS THE AREA EARLY THURSDAY
MORNING...BUT EXPECT IT TO MOVE OFF OVER EASTERN NEBRASKA BY MID
MORNING. SKIES ARE EXPECTED TO CLEAR AND HIGHS...IF NOT IMPACTED
MUCH BY ANY SNOW ACCUMULATION OVERNIGHT WILL REACH INTO THE 30S TO
LOW 40S.
ON CHRISTMAS DAY A PIECE OF THE MAIN DISTURBANCE THAT WILL IMPACT
THE REGION FOR THE WEEKEND INTO EARLY NEXT WEEK WILL BREAK OFF AND
MOVE NORTHEAST ACROSS THE AREA. THIS WILL BRING THE POSSIBILITY
FOR PRECIPITATION MAINLY ACROSS NORTHERN NEBRASKA...BUT SOME COULD
CREEP INTO CENTRAL NEBRASKA DURING THE LATE AFTERNOON AND
OVERNIGHT. HIGHS WILL BE SIMILAR TO THURSDAY.
SATURDAY - TUESDAY:
THIS PERIOD IS THE MOST CHALLENGING. THE GUIDANCE HAS EVOLVED FROM
LAST NIGHT`S...GIVING A SLOWER SOLUTION...TRENDING TOWARDS LAST
NIGHTS ECMWF. THE SLOWER/FURTHER SOUTH ROUTE IS IMPACTING THE
AREA OF PRECIPITATION POTENTIAL. CONFIDENCE ON THIS PART OF THE
FORECAST IS RELATIVELY LOW. CONFIDENCE IS HIGH THAT A SYSTEM WILL
IMPACT THE CENTRAL AND SOUTHERN PLAINS...BUT THE DETAILS OF WHEN
AND WHERE ARE STILL VERY UNCLEAR.
WHILE LAST NIGHT`S FORECAST HAD SATURDAY NIGHT THROUGH SUNDAY IN
THE PERIOD WITH THE BEST CHANCES FOR ACCUMULATING SNOW...THIS HAS
CHANGED...WITH SUNDAY NIGHT INTO TUESDAY WITH THE LARGER CONCERN.
THIS IS NOT OVERLY UNEXPECTED WITH THE SLOWER SOLUTION. SO AS TO
NOT FLIP FLOP ON THE FORECAST HAVE KEPT PRECIPITATION CHANCES FOR
SATURDAY AND SUNDAY...BUT WITH THE CURRENT GUIDANCE...CHANCES ARE
MUCH LESS. A COLD FRONT WILL MOVE THROUGH VERY EARLY SATURDAY
MORNING WHICH WILL DROP TEMPERATURES WITH BREEZY NORTH WINDS. THIS
WILL CAUSE HIGHS FOR THE REMAINDER OF THE FORECAST TO BE IN THE
20S.
THE GFS DID SLOW TO CONVERGE ON A SOLUTION SIMILAR TO THE
ECMWF...BUT IT STILL EJECTS THE DISTURBANCE NORTHEASTWARD QUICKER
ON MONDAY MORNING. WHEREAS THE ECMWF PULLS THE UPPER LOW AND
ASSOCIATED SURFACE LOW ACROSS THE AREA MONDAY NIGHT INTO TUESDAY.
THE SLOWER SOLUTION ALLOWS THE TEMPERATURES TO REMAIN COLD ENOUGH
THROUGHOUT THE COLUMN FOR SNOW TO BE THE MAIN PRECIPITATION TYPE
AFTER THE TRANSITION WITH THE COLD FRONT ON SATURDAY THROUGH THE
REMAINDER OF THE WEEKEND INTO EARLY NEXT WEEK.
DUE TO THE LOW CONFIDENCE WITH MODEL DISCREPANCIES...STILL THINK
SOME TRAVEL THROUGH THE CENTRAL AND SOUTHERN PLAINS WILL BE
HAZARDOUS FOR PORTIONS OF THE HOLIDAY WEEKEND. IT IS STILL TOO
EARLY TO SPECULATE ON SNOW ACCUMULATIONS...ESPECIALLY WITH THE
MODEL CHANGES...BUT SNOW ACCUMULATION IS POSSIBLE THIS WEEKEND
INTO THE BEGINNING OF THE WEEK. STAY TUNED TO THE FORECASTS AS IT
CONTINUES TO EVOLVE AND THE DETAILS ARE REFINED.
&&
.AVIATION...(FOR THE 18Z KGRI/KEAR TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1124 AM CST WED DEC 23 2015
CLEARING SKIES AND VFR CONDITIONS HAVE BASICALLY SETTLED INTO
KGRI/KEAR AND WILL CONTINUE THROUGH THE AFTERNOON. WINDS WILL
BE IN THE 15KT RANGE BUT DROP OFF QUICKLY NEAR SUNSET. NEXT
WEATHER SYSTEM WILL SPREAD LIGHT SNOW ACROSS SOUTHERN NEBRASKA
AND NORTHERN KANSAS OVERNIGHT...MAINLY AFTERNOON MIDNIGHT...
WHICH WILL LIKELY RESULT IN MVFR VISIBILITIES AND CEILINGS FOR
TIME AT BOTH SITES.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BILLINGS WRIGHT
AVIATION...NOAA/NWS/MORITZ
AREA FORECAST DISCUSSION
NWS HASTINGS NE
516 AM CST WED DEC 23 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST WED DEC 23 2015
RADAR HAS AREAS OF LIGHT RAIN MOVING THROUGH THE EASTERN PART OF THE
FORECAST AREA EARLY THIS MORNING. TEMPERATURES IN THE AREA OF RAIN
ARE WARM ENOUGH AT THIS TIME TO CONTINUE TO BE RAIN. TO THE WEST OF
THE RAIN THE TEMPERATURES HAVE STARTED TO COOL OFF.
THROUGH DAYBREAK AND INTO THE MORNING HOURS AN UPPER LEVEL LOW IS
MOVING THROUGH THE AREA. EVEN THOUGH IT IS IN THE FIRST FEW HOURS OF
THE FORECAST...THERE ARE A FEW DIFFERENCES. THE HRRR AND RAP KEEP
PRECIPITATION ONLY IN THE FAR EAST WHILE THE 4KM WRF...NAM AND GFS
PUSH THE PRECIPITATION FURTHER TO THE EAST. THE BEST CHANCE WILL
DEFINITELY BE IN THE EAST...BUT HAVE KEPT SOME LOWER POPS FURTHER TO
THE WEST. THIS BRINGS IN A PROBLEM FOR PRECIPITATION TYPE. WHILE THE
TEMPERATURES ALOFT ARE WARM ENOUGH FOR RAIN...SO IS THE SURFACE.
ONCE THE TEMPERATURES ALOFT COOL OFF THE SURFACE DOES AS
WELL...MAKING A CHANGE TO SNOW. HAVE KEPT A RAIN AND SNOW MIX IN THE
WEST/NORTHWEST THROUGH DAY BREAK AND INTO THE MORNING HOURS AS THE
PRECIPITATION IS MOVING OUT OF THE AREA. BY MID DAY THE UPPER LOW
HAS MOVED EAST AND EXPECT THAT PRECIPITATION SHOULD COME TO AN END.
THERE WILL ALSO BE SOME CLEARING AND A LITTLE SUNSHINE FOR A TIME
THIS AFTERNOON.
THE NEXT UPPER LEVEL WAVE WILL BE MOVING INTO THE AREA TONIGHT.
EXPECT PRECIPITATION TO MOVE INTO THE AREA FROM THE SOUTHWEST
TONIGHT. TEMPERATURES ARE EXPECTED TO BE COLD ENOUGH THAT EXPECT
SNOW ACROSS THE ENTIRE AREA. THE BEST CHANCE FOR ACCUMULATING SNOW
WILL BE MAINLY LATE TONIGHT. THROUGH MORNING...EXPECT THERE TO BE
LESS THAN AN INCH OR LESS OF SNOW.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 347 AM CST WED DEC 23 2015
THE MID AND LONG TERM FORECASTS CONTINUE TO BE INTERESTING AND
CHALLENGING.
CHRISTMAS EVE - CHRISTMAS NIGHT:
THERE MAY BE SOME LINGERING SNOW ACROSS THE AREA EARLY THURSDAY
MORNING...BUT EXPECT IT TO MOVE OFF OVER EASTERN NEBRASKA BY MID
MORNING. SKIES ARE EXPECTED TO CLEAR AND HIGHS...IF NOT IMPACTED
MUCH BY ANY SNOW ACCUMULATION OVERNIGHT WILL REACH INTO THE 30S TO
LOW 40S.
ON CHRISTMAS DAY A PIECE OF THE MAIN DISTURBANCE THAT WILL IMPACT
THE REGION FOR THE WEEKEND INTO EARLY NEXT WEEK WILL BREAK OFF AND
MOVE NORTHEAST ACROSS THE AREA. THIS WILL BRING THE POSSIBILITY
FOR PRECIPITATION MAINLY ACROSS NORTHERN NEBRASKA...BUT SOME COULD
CREEP INTO CENTRAL NEBRASKA DURING THE LATE AFTERNOON AND
OVERNIGHT. HIGHS WILL BE SIMILAR TO THURSDAY.
SATURDAY - TUESDAY:
THIS PERIOD IS THE MOST CHALLENGING. THE GUIDANCE HAS EVOLVED FROM
LAST NIGHT`S...GIVING A SLOWER SOLUTION...TRENDING TOWARDS LAST
NIGHTS ECMWF. THE SLOWER/FURTHER SOUTH ROUTE IS IMPACTING THE
AREA OF PRECIPITATION POTENTIAL. CONFIDENCE ON THIS PART OF THE
FORECAST IS RELATIVELY LOW. CONFIDENCE IS HIGH THAT A SYSTEM WILL
IMPACT THE CENTRAL AND SOUTHERN PLAINS...BUT THE DETAILS OF WHEN
AND WHERE ARE STILL VERY UNCLEAR.
WHILE LAST NIGHT`S FORECAST HAD SATURDAY NIGHT THROUGH SUNDAY IN
THE PERIOD WITH THE BEST CHANCES FOR ACCUMULATING SNOW...THIS HAS
CHANGED...WITH SUNDAY NIGHT INTO TUESDAY WITH THE LARGER CONCERN.
THIS IS NOT OVERLY UNEXPECTED WITH THE SLOWER SOLUTION. SO AS TO
NOT FLIP FLOP ON THE FORECAST HAVE KEPT PRECIPITATION CHANCES FOR
SATURDAY AND SUNDAY...BUT WITH THE CURRENT GUIDANCE...CHANCES ARE
MUCH LESS. A COLD FRONT WILL MOVE THROUGH VERY EARLY SATURDAY
MORNING WHICH WILL DROP TEMPERATURES WITH BREEZY NORTH WINDS. THIS
WILL CAUSE HIGHS FOR THE REMAINDER OF THE FORECAST TO BE IN THE
20S.
THE GFS DID SLOW TO CONVERGE ON A SOLUTION SIMILAR TO THE
ECMWF...BUT IT STILL EJECTS THE DISTURBANCE NORTHEASTWARD QUICKER
ON MONDAY MORNING. WHEREAS THE ECMWF PULLS THE UPPER LOW AND
ASSOCIATED SURFACE LOW ACROSS THE AREA MONDAY NIGHT INTO TUESDAY.
THE SLOWER SOLUTION ALLOWS THE TEMPERATURES TO REMAIN COLD ENOUGH
THROUGHOUT THE COLUMN FOR SNOW TO BE THE MAIN PRECIPITATION TYPE
AFTER THE TRANSITION WITH THE COLD FRONT ON SATURDAY THROUGH THE
REMAINDER OF THE WEEKEND INTO EARLY NEXT WEEK.
DUE TO THE LOW CONFIDENCE WITH MODEL DISCREPANCIES...STILL THINK
SOME TRAVEL THROUGH THE CENTRAL AND SOUTHERN PLAINS WILL BE
HAZARDOUS FOR PORTIONS OF THE HOLIDAY WEEKEND. IT IS STILL TOO
EARLY TO SPECULATE ON SNOW ACCUMULATIONS...ESPECIALLY WITH THE
MODEL CHANGES...BUT SNOW ACCUMULATION IS POSSIBLE THIS WEEKEND
INTO THE BEGINNING OF THE WEEK. STAY TUNED TO THE FORECASTS AS IT
CONTINUES TO EVOLVE AND THE DETAILS ARE REFINED.
&&
.AVIATION...(FOR THE 12Z KGRI/KEAR TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 513 AM CST WED DEC 23 2015
THERE WILL BE A FEW LOWER CLOUDS AND MAYBE A SPRINKLE THIS MORNING
BUT THAT WILL MOVE TO THE EAST AND HAVE SOME SUN FOR THE
AFTERNOON. CLOUDS WILL RETURN TO THE AREA LATE THIS AFTERNOON AND
EVENING AND LATE TONIGHT EXPECT SOME MVFR CEILINGS AND VISIBILITY
WITH A CHANCE FOR SOME SNOW.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BILLINGS WRIGHT
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS HASTINGS NE
400 AM CST WED DEC 23 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST WED DEC 23 2015
RADAR HAS AREAS OF LIGHT RAIN MOVING THROUGH THE EASTERN PART OF THE
FORECAST AREA EARLY THIS MORNING. TEMPERATURES IN THE AREA OF RAIN
ARE WARM ENOUGH AT THIS TIME TO CONTINUE TO BE RAIN. TO THE WEST OF
THE RAIN THE TEMPERATURES HAVE STARTED TO COOL OFF.
THROUGH DAYBREAK AND INTO THE MORNING HOURS AN UPPER LEVEL LOW IS
MOVING THROUGH THE AREA. EVEN THOUGH IT IS IN THE FIRST FEW HOURS OF
THE FORECAST...THERE ARE A FEW DIFFERENCES. THE HRRR AND RAP KEEP
PRECIPITATION ONLY IN THE FAR EAST WHILE THE 4KM WRF...NAM AND GFS
PUSH THE PRECIPITATION FURTHER TO THE EAST. THE BEST CHANCE WILL
DEFINITELY BE IN THE EAST...BUT HAVE KEPT SOME LOWER POPS FURTHER TO
THE WEST. THIS BRINGS IN A PROBLEM FOR PRECIPITATION TYPE. WHILE THE
TEMPERATURES ALOFT ARE WARM ENOUGH FOR RAIN...SO IS THE SURFACE.
ONCE THE TEMPERATURES ALOFT COOL OFF THE SURFACE DOES AS
WELL...MAKING A CHANGE TO SNOW. HAVE KEPT A RAIN AND SNOW MIX IN THE
WEST/NORTHWEST THROUGH DAY BREAK AND INTO THE MORNING HOURS AS THE
PRECIPITATION IS MOVING OUT OF THE AREA. BY MID DAY THE UPPER LOW
HAS MOVED EAST AND EXPECT THAT PRECIPITATION SHOULD COME TO AN END.
THERE WILL ALSO BE SOME CLEARING AND A LITTLE SUNSHINE FOR A TIME
THIS AFTERNOON.
THE NEXT UPPER LEVEL WAVE WILL BE MOVING INTO THE AREA TONIGHT.
EXPECT PRECIPITATION TO MOVE INTO THE AREA FROM THE SOUTHWEST
TONIGHT. TEMPERATURES ARE EXPECTED TO BE COLD ENOUGH THAT EXPECT
SNOW ACROSS THE ENTIRE AREA. THE BEST CHANCE FOR ACCUMULATING SNOW
WILL BE MAINLY LATE TONIGHT. THROUGH MORNING...EXPECT THERE TO BE
LESS THAN AN INCH OR LESS OF SNOW.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 347 AM CST WED DEC 23 2015
THE MID AND LONG TERM FORECASTS CONTINUE TO BE INTERESTING AND
CHALLENGING.
CHRISTMAS EVE - CHRISTMAS NIGHT:
THERE MAY BE SOME LINGERING SNOW ACROSS THE AREA EARLY THURSDAY
MORNING...BUT EXPECT IT TO MOVE OFF OVER EASTERN NEBRASKA BY MID
MORNING. SKIES ARE EXPECTED TO CLEAR AND HIGHS...IF NOT IMPACTED
MUCH BY ANY SNOW ACCUMULATION OVERNIGHT WILL REACH INTO THE 30S TO
LOW 40S.
ON CHRISTMAS DAY A PIECE OF THE MAIN DISTURBANCE THAT WILL IMPACT
THE REGION FOR THE WEEKEND INTO EARLY NEXT WEEK WILL BREAK OFF AND
MOVE NORTHEAST ACROSS THE AREA. THIS WILL BRING THE POSSIBILITY
FOR PRECIPITATION MAINLY ACROSS NORTHERN NEBRASKA...BUT SOME COULD
CREEP INTO CENTRAL NEBRASKA DURING THE LATE AFTERNOON AND
OVERNIGHT. HIGHS WILL BE SIMILAR TO THURSDAY.
SATURDAY - TUESDAY:
THIS PERIOD IS THE MOST CHALLENGING. THE GUIDANCE HAS EVOLVED FROM
LAST NIGHT`S...GIVING A SLOWER SOLUTION...TRENDING TOWARDS LAST
NIGHTS ECMWF. THE SLOWER/FURTHER SOUTH ROUTE IS IMPACTING THE
AREA OF PRECIPITATION POTENTIAL. CONFIDENCE ON THIS PART OF THE
FORECAST IS RELATIVELY LOW. CONFIDENCE IS HIGH THAT A SYSTEM WILL
IMPACT THE CENTRAL AND SOUTHERN PLAINS...BUT THE DETAILS OF WHEN
AND WHERE ARE STILL VERY UNCLEAR.
WHILE LAST NIGHT`S FORECAST HAD SATURDAY NIGHT THROUGH SUNDAY IN
THE PERIOD WITH THE BEST CHANCES FOR ACCUMULATING SNOW...THIS HAS
CHANGED...WITH SUNDAY NIGHT INTO TUESDAY WITH THE LARGER CONCERN.
THIS IS NOT OVERLY UNEXPECTED WITH THE SLOWER SOLUTION. SO AS TO
NOT FLIP FLOP ON THE FORECAST HAVE KEPT PRECIPITATION CHANCES FOR
SATURDAY AND SUNDAY...BUT WITH THE CURRENT GUIDANCE...CHANCES ARE
MUCH LESS. A COLD FRONT WILL MOVE THROUGH VERY EARLY SATURDAY
MORNING WHICH WILL DROP TEMPERATURES WITH BREEZY NORTH WINDS. THIS
WILL CAUSE HIGHS FOR THE REMAINDER OF THE FORECAST TO BE IN THE
20S.
THE GFS DID SLOW TO CONVERGE ON A SOLUTION SIMILAR TO THE
ECMWF...BUT IT STILL EJECTS THE DISTURBANCE NORTHEASTWARD QUICKER
ON MONDAY MORNING. WHEREAS THE ECMWF PULLS THE UPPER LOW AND
ASSOCIATED SURFACE LOW ACROSS THE AREA MONDAY NIGHT INTO TUESDAY.
THE SLOWER SOLUTION ALLOWS THE TEMPERATURES TO REMAIN COLD ENOUGH
THROUGHOUT THE COLUMN FOR SNOW TO BE THE MAIN PRECIPITATION TYPE
AFTER THE TRANSITION WITH THE COLD FRONT ON SATURDAY THROUGH THE
REMAINDER OF THE WEEKEND INTO EARLY NEXT WEEK.
DUE TO THE LOW CONFIDENCE WITH MODEL DISCREPANCIES...STILL THINK
SOME TRAVEL THROUGH THE CENTRAL AND SOUTHERN PLAINS WILL BE
HAZARDOUS FOR PORTIONS OF THE HOLIDAY WEEKEND. IT IS STILL TOO
EARLY TO SPECULATE ON SNOW ACCUMULATIONS...ESPECIALLY WITH THE
MODEL CHANGES...BUT SNOW ACCUMULATION IS POSSIBLE THIS WEEKEND
INTO THE BEGINNING OF THE WEEK. STAY TUNED TO THE FORECASTS AS IT
CONTINUES TO EVOLVE AND THE DETAILS ARE REFINED.
&&
.AVIATION...(FOR THE 06Z KGRI/KEAR TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1119 PM CST TUE DEC 22 2015
A SURFACE TROUGH HAS MOVED THROUGH THE TERMINALS. THERE IS AN
UPPER LEVEL WAVE THAT MOVES THROUGH AROUND DAY BREAK. EXPECT THERE
TO BE SOME PRECIPITATION AROUND THE AREA AS THE UPPER LEVEL WAVE
MOVES THROUGH. THE PRECIPITATION WILL MOVE OUT WITH A BREAK
THROUGH MUCH OF THE REMAINDER OF THE PERIOD. TOWARD THE VERY END
THERE IS ANOTHER CHANCE FOR SOME PRECIPITATION.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...JCB
LONG TERM...BILLINGS WRIGHT
AVIATION...JCB
AREA FORECAST DISCUSSION
NWS LAS VEGAS NV
1002 PM PST TUE DEC 22 2015
.SYNOPSIS...A MOIST NORTHWEST FLOW WILL BRING OCCASIONAL CLOUDS AND
GUSTY WINDS TO THE REGION THROUGH WEDNESDAY. ANOTHER SYSTEM WILL
APPROACH THE AREA ON CHRISTMAS EVE DAY THEN PASS THROUGH AT NIGHT
WITH ANOTHER ROUND OF GUSTY WINDS AND SHOWERS POSSIBLE. CHILLY BUT
DRY WEATHER IS EXPECTED FROM CHRISTMAS DAY THROUGH THE WEEKEND.
&&
.UPDATE...ANOTHER ROUND OF FUN AND GAMES WITH THE WIND THIS EVENING
AS NORTH TO NORTHWEST WINDS HOWLED DOWN THE OWENS VALLEY AND
ADJACENT EASTERN SIERRA SLOPES THIS AFTERNOON AND THEN ACROSS
NORTHWEST SAN BERNARDINO COUNTY THIS EVENING. THE HRRR AND SOME HIGH-
RESOLUTION MODELS HAVE NOT HANDLED THIS WELL AT ALL AND THUS THE GFS
LAMP SEEMS TO BE MORE ON TARGET WITH WITH SPEEDS WHICH LOOK TO STAY
UP ENOUGH OVERNIGHT IN NORTHWEST SAN BERNARDINO COUNTY TO JUSTIFY AN
ADVISORY. AS A RESULT, I ISSUED ONE AND RAN IT THROUGH 10 AM
WEDNESDAY SINCE WINDS HAVE NOT BEEN COOPERATING THE BEST AND MAY BE
RELUCTANT TO DIMINISH.
THE NEXT ISSUE TONIGHT IS WAY IN THE EASTERN PART OF OUR AREA AS
SURFACE DEWPOINTS HAVE HELD UP AGAINST GUIDANCE AND HIGHER LEVEL
CLOUDS HAVE CLEARED ON OUT BY SURFACE OBSERVATIONS SHOW BKN-OVC
REPORTS STILL. I ADJUSTED UP SKY COVER AFTER LOOKING AT FORECAST
SOUNDINGS WHICH KEEP THE LOW-LEVELS IN THE PLATEAU COUNTRY OF MOHAVE
COUNTY NEARLY SATURATED OVERNIGHT AND INTO EARLY WEDNESDAY MORNING.
I ALSO ADDED PATCHY FOG TO THE GRIDS AS WHATEVER STRATUS DECK IS
THERE MAY DROP DOWN TO THE SURFACE LATER TONIGHT. IN AREAS WHERE
TEMPS FALL TO OR BELOW FREEZING BLACK ICE IS POSSIBLE ON ROADS. THE
MOST AT RISK AREAS WILL BE ON INTERSTATE 40 AND ROUTE 66 EAST OF
KINGMAN AS WELL AS IN AND AROUND COLORADO CITY. THERE IS ALSO SOME
POTENTIAL FOR FOG IN AND AROUND LAS VEGAS OVERNIGHT, BUT CONFIDENCE
IS LOWER IN THIS.
LASTLY, LIGHT SNOW HAS BEEN REPORTED AT ELY IN THE LAST HOUR AND
ALTHOUGH POPS WERE ADJUSTED IN SOME SPOTS TO BAG PRECIP, THIS SHOWER
ACTIVITY COULD STILL ROLL INTO NORTHERN LINCOLN COUNTY LATER ON.
&&
.AVIATION...FOR MCCARRAN...WESTERLY WINDS TO SOUTHWEST AT TIMES AT 4-
8 KTS OVERNIGHT. WINDS ARE FORECAST TO BE NORTH TO NORTHEAST
WEDNESDAY WITH SPEEDS BETWEEN 6-8 KTS BEFORE TURNING TO THE
SOUTHWEST TO WEST AROUND 03Z THURSDAY. THERE IS ENOUGH LOW-LEVEL
MOISTURE THAT AREAS OF FOG OR LOWER CLOUDS MAY DEVELOP IN AND AROUND
THE LAS VEGAS VALLEY LATE TONIGHT INTO WEDNESDAY MORNING. HOWEVER,
CONFIDENCE IS LOW IN THIS. THE BEST WINDOW WOULD BE BETWEEN 10Z AND
17Z WEDNESDAY. OTHERWISE, LOOK FOR MAINLY SCT CLOUDS AOA 7K FEET.
FOR THE REST OF SOUTHERN NEVADA...NORTHWEST ARIZONA...AND SOUTHEAST
CALIFORNIA...WESTERLY WINDS GUSTING TO 30-40 KTS OVERNIGHT THROUGH
18Z WEDNESDAY IN NW SAN BERNARDINO COUNTY WITH POSSIBLE PATCHY BLDU.
OTHERWISE MAINLY DIURNAL WINDS UNDER 10 KTS OVERNIGHT AND AGAIN ON
WEDNESDAY EXCEPT IN THE SOUTHERN GREAT BASIN WHERE NORTHWEST TO
NORTH WINDS OF 6-12 KTS WITH GUSTS TO 20 KTS ARE POSSIBLE. AREAS OF
FOG AND LOW CLOUDS WITH BASES DOWN TO AT LEAST 500 FEET ARE POSSIBLE
LATE TONIGHT MAINLY NORTH AND EAST OF KIGM INCLUDING IN AND AROUND
KAZC. THERE IS ALSO SOME POTENTIAL AS WELL IN PARTS OF SOUTHERN
NEVADA. THE MAIN WINDOW WOULD BE BETWEEN 10Z AND 17Z WEDNESDAY.
OTHERWISE, MAINLY SCT-BKN CLOUDS AT TIMES AOA 7K FEET. ISOLATED
SHOWERS ARE POSSIBLE OVERNIGHT AND EARLY WEDNESDAY IN FAR NORTHERN
LINCOLN COUNTY AND IN AND AROUND KAZC.
&&
.SHORT TERM...THROUGH WEDNESDAY NIGHT.
NORTHWEST FLOW WILL CONTINUE OVER THE REGION THROUGH WEDNESDAY WITH
OCCASIONAL CLOUDS AND A FEW SHOWERS POSSIBLE OVER THE FAR NORTHERN
AND EASTERN PORTIONS OF THE FORECAST AREA. WINDS ARE EXPECTED TO BE
LIGHTER WEDNESDAY ALONG WITH SOME LIGHT ISOLATED SHOWERS MAINLY OVER
THE HIGHER ELEVATIONS. TEMPERATURES WILL REMAIN CLOSE TO NORMAL.
.LONG TERM...THURSDAY THROUGH MONDAY.
NEXT STORM SYSTEM TO AFFECT THE REGION WILL MOVE IN THURSDAY IN THE
FORM OF YET ANOTHER FAST MOVING STORM SYSTEM FROM THE NORTHWEST.
MUCH LIKE THE LAST SEVERAL STORMS...THIS SYSTEM ONLY CLIPS US AND
MOVES FROM WEST TO EAST FAIRLY RAPIDLY LIMITING ANY POTENTIAL
IMPACTS. NONETHELESS...WIND AND SOME WINTER WEATHER IMPACTS CAN
STILL BE EXPECTED ESPECIALLY GIVEN THE SENSITIVE NATURE OF THE
HOLIDAY TRAVEL PERIOD.
WINDS WILL BEGIN PICKING UP ALONG A BELT STRETCHING FROM THE WESTERN
MOJAVE DESERT EAST INTO NORTHWEST ARIZONA ON THURSDAY AND ITS LIKELY
SOME WIND PRODUCTS WILL BE NEEDED DOWN THE LINE TO ACCOUNT FOR THIS.
AS THE TROUGH QUICKLY PROGRESSES FROM NORTHERN CALIFORNIA ACROSS THE
GREAT BASIN IT WILL DRAG A FAIRLY STRONG COLD FRONT SOUTHWARD WITH
IT. WHILE RAIN AND SNOWFALL WILL BE FAIRLY LIGHT WITH THIS QUICK
MOVING FRONT...PARTS OF LINCOLN COUNTY AND NORTHERN MOHAVE COUNTY
STAND THE CHANCE TO PICK UP A QUICK FEW INCHES OF SNOW...AND THESE
AREAS VERY WELL MAY WAKE UP TO A WHITE CHRISTMAS. WE WILL NEED TO
CONSIDER THE NEED FOR A WINTER WEATHER ADVISORY AS THE EVENT DRAWS
CLOSER DUE TO THE SENSITIVE NATURE OF HOLIDAY TRAVEL ON CHRISTMAS
EVE AND CHRISTMAS DAY. ELSEWHERE...ONLY LIGHT AMOUNTS OF RAIN OR
SNOW ARE EXPECTED WITH VERY LITTLE OR NO SNOW ACCUMULATION.
THINGS WILL QUICKLY DRY OUT ON CHRISTMAS DAY WITH STRONG NORTH WINDS
BECOMING THE GREATER CONCERN. NORTH WINDS WILL CONTINUE TO
STRENGTHEN INTO SATURDAY AS THE LOW CUTS OFF AND DIGS SOUTH INTO
ARIZONA...INDUCING A STRONG NORTH FLOW INTO OUR REGION. WINDS MAY
END UP BECOMING QUITE STRONG ESPECIALLY IN FAVORABLE LOCATIONS FOR
NORTH WINDS...SUCH AS DOWN THE LOWER COLORADO RIVER NEAR NEEDLES AND
LAUGHLIN. HIGH WIND PRODUCTS ARE A DEFINITE POSSIBILITY FRIDAY
NIGHT-SATURDAY AND IT WOULD BE ADVISABLE AT THIS POINT TO RECONSIDER
OUTDOOR RECREATION PLANNED SATURDAY ON THE AREA LAKES.
OUTSIDE OF WIND AND WEATHER...TEMPERATURES WILL BE SHARPLY COOLER
FRIDAY ONWARD AS THE COLD FRONT PUSHES EAST AND STRONG NORTH FLOW
LINGERS OVER THE AREA. TEMPERATURES IN LAS VEGAS ARE LIKELY TO
REMAIN BELOW 50 FOR A PERIOD OF SEVERAL DAYS WITH SUBFREEZING
TEMPERATURES POSSIBLE AT NIGHT DEPENDING ON THE WINDS. THE ENTIRE
REGION WILL BE AVERAGING 8 TO 12 DEGREES BELOW SEASONAL NORMALS FOR
HIGH TEMPERATURES. THE HOLIDAY SEASON IS HERE...AND IT WILL SURE
FEEL LIKE IT!
&&
.SPOTTER INFORMATION STATEMENT...SPOTTERS ARE ENCOURAGED TO REPORT
ANY SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING
PROCEDURES.
&&
$$
UPDATE/AVIATION...STACHELSKI
SHORT TERM...GORELOW
LONG TERM...OUTLER
FOR MORE FORECAST INFORMATION...SEE US ON OUR WEBPAGE:
HTTP://WEATHER.GOV/LASVEGAS OR FOLLOW US ON FACEBOOK AND TWITTER
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
300 PM EST WED DEC 23 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH THE WEEKEND. A WEAK
COLD FRONT WILL APPROACH FROM THE NORTH THURSDAY NIGHT THEN STALL
NEAR THE VIRGINIA BORDER FRIDAY. THE FRONT WILL LIFT BACK NORTH
OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1020 AM WEDNESDAY...LATE MORNING UPDATE FOR ONLY MINOR
TWEAKS IN THE NEAR TERM. CONVECTION HAS SHOWN POTENTIAL TO BECOME
SEVERE FOR WESTERN ZONES (DUPLIN/ONSLOW/GREENE/LENOIR COUNTIES)
WHERE SPC MESOANALYSES INDICATE BETTER INSTABILITY. IR SATELLITE
IMAGERY INDICATED WARMING CLOUD TOPS AS THE EARLIER CONVECTION
SHIFTS NORTH ACROSS THE HWY 64 CORRIDOR. A PERIOD OF HEAVY RAIN
AND POSSIBLY GUSTY WINDS WILL STILL BE POSSIBLE INTO EARLY
AFTERNOON WITH SHOWER COVERAGE INCREASING FROM THE SOUTH AND WEST.
THE SYNOPTIC PATTERN PRESENTS AN UPPER TROUGH MOVING INTO THE
PLAINS WITH RIDGING OVER THE ATLANTIC, BRINGING DEEP SW FLOW
ACROSS THE EASTERN CONUS THAT IS TAPPING INTO TROPICAL PACIFIC
MOISTURE BRINGING PWATS AROUND 1.75 INCHES WHICH IS AT OR ABOVE
CLIMATOLOGICAL MAXIMUM FOR LATE DECEMBER. SFC HIGH PRES REMAINS
CENTERED OFFSHORE WITH A COASTAL TROUGH JUST SOUTH OF THE REGION
PROGGED TO LIFT ACROSS THE REGION TODAY. THIS PATTERN WILL
CONTINUE TO BRING PERIODS OF SHOWERS ACROSS THE REGION TODAY WHICH
ARE BEING ENHANCED BY WEAK EMBEDDED SHORTWAVES MOVING THROUGH THE
FLOW ALOFT. COULD SEE A FEW STRONGER STORMS DEVELOP THROUGH THE
AFTERNOON HOURS AS THE AIRMASS DESTABILIZES IN THE PRESENCE OF
STRONG LOW LEVEL SHEAR. HRRR IS FORECASTING MLCAPE AROUND
1000-1500J/KG AND LI`S AROUND -4C WITH 40-50 KT 0-6KM SHEAR AND
0-1KM HELICITY AROUND 200-300 M2/S2 THIS AFTERNOON WITH HIGHEST
VALUES WEST OF HIGHWAY 17. SPC HAS MOST OF THE REGION OUTLOOKED
FOR A MARGINAL RISK OF SEVERE THUNDERSTORMS WITH DAMAGING WIND
GUSTS AND AN ISOLATED TORNADO THE PRIMARY THREAT. PERIODS OF HEAVY
RAINFALL WITH LOCALIZED FLOODING OF POOR DRAINAGE AND LOW LYING
AREA WILL ALSO BE POSSIBLE. EXPECT GUSTY SLY WINDS TO DEVELOP LATE
MORNING THROUGH THE AFTERNOON IN THE WAKE OF THE TROUGH LIFTING
ACROSS THE REGION WHICH COULD BRING GUSTS AROUND 20-30 MPH. TEMPS
WILL BE ALMOST 20 DEGREES ABOVE NORMAL WITH HIGHS EXPECTED IN THE
MID 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS OF 3 AM WEDNESDAY....LITTLE CHANGE IN THE PATTERN TONIGHT WITH
MOIST SW FLOW CONTINUING. A FEW STRONGER STORMS WILL BE POSSIBLE
EARLY IN THE EVENING BUT GENERALLY EXPECT A DECREASE IN COVERAGE
THROUGH THE OVERNIGHT AS SHORTWAVE ENERGY LIFTS NORTH OF THE
REGION AND THE UPPER RIDGE OVER THE WESTERN ATLANTIC BEGINS TO
BUILDS WEST SOME. WILL CONTINUE A DECREASING TREND IN POPS THROUGH
THE OVERNIGHT. MODERATE SLY WINDS WILL BRING VERY MILD OVERNIGHT
TEMPS IN THE UPPER 60S TO 70...WHICH IS ABOUT 30-35 DEGREES ABOVE
NORMAL AND WILL LIKELY BREAK RECORD HIGH MINIMUM TEMPERATURES FOR
THE DAY...SEE CLIMATE SECTION BELOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 300 PM WED...EXPECT RECORD BREAKING WARMTH THROUGH MUCH OF
THE PERIOD AS STRONG UPPER RIDGE OVER THE ATLANTIC BUILDS WEST
TOWARD THE COAST INTO THE WEEKEND.
THURSDAY NIGHT THROUGH CHRISTMAS DAY...COVERAGE OF PRECIPITATION
WILL DROP A BIT THURSDAY NIGHT AND FRIDAY AS UPR RDG GRAD BUILDS
W. UPR RDG BUILDS CLOSER WHICH WILL ACT TO SUPPRESS CONVECTION
AND WITH MORE SUN TEMPS WILL AGAIN BE VERY WARM REACHING AROUND 80
WARMER SPOTS ON CHRISTMAS DAY.
SATURDAY THROUGH SUNDAY...STRONG UPPER LEVEL RIDGE HOLDS ACROSS
THE SOUTHEASTERN UNITED STATES THROUGH THE WEEKEND AS LOW
PRESSURE MOVES FROM THE MISSISSIPPI VALLEY INTO THE GREAT LAKES
REGION. THIS WILL KEEP UNSEASONABLY WARM TEMPERATURES IN PLACE
WITH DAYTIME HIGHS WELL INTO THE 70S SATURDAY AND SUNDAY WITH LOWS
IN THE 60S. THERE WILL BE ONLY A SMALL CHANCE OF SHOWERS EACH DAY
GIVEN THE CONTINUED RATHER MOIST AIRMASS WITH FORECAST
PRECIPITABLE WATER VALUES AOA 1.50 INCHES.
MONDAY THROUGH WEDNESDAY...UPR RDG WILL BEGIN TO SHIFT BACK E
WITH MDLS SHOWING BACKDOOR FRONT DROPPING INTO THE REGION LATE
SUNDAY NIGHT OR EARLY MON THEN LIFTING BACK N TUE AHEAD OF
STRONGER APPROACHING FRONT. CONT PREV FCST OF CHC POPS EARLY NEXT
WEEK WITH STILL VERY MILD TEMPS IN THE 60S TO LOWER 70S...POSS
SOME MID 70S TUE/WED. A COLD FRONT APPROACHES FROM THE WEST ON
WEDNESDAY BUT TIMING OF THE FRONTAL PASSAGE VERY MUCH IN QUESTION
GIVEN THE POTENTIAL ERROR IN THE DAY 7 FORECAST. WILL CONTINUE
WITH ABOVE NORMAL TEMPS AND CHC POPS THRU MIDWEEK FOR NOW.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM WEDNESDAY...HIGH CONFIDENCE OF MVFR CONDITIONS WILL
PERSIST MOST OF THE TAF PERIOD. WITH A MOIST SW FLOW...PERIODS OF
SHOWERS WILL CONTINUE ACROSS THE AREA. SOME STORMS COULD BE
STRONG TO MARGINALLY SEVERE THIS AFTERNOON IF INSTABILITY CAN BE
REALIZED WITH STRONG SHEAR IN PLACE AND SHORTWAVE ENERGY MOVING
ACROSS THE REGION. THESE SHOWERS/THUNDERSTORMS ARE EXPECT TO BRIEFLY
REDUCE VSBYS/CEILINGS. SOUTHERLY WINDS 10-15 KTS WITH GUSTS 20 TO
25 KNOTS REDUCING DOWN TO AROUND 10 KTS OVERNIGHT. FORECASTING
SOUNDING AND GUIDANCE CONTINUES TO SHOW MVFR CEILINGS FOR TONIGHT
AND REDUCING DOWN TO IFR CEILINGS AROUND 7/8Z. CEILINGS ARE
EXPECTED TO INCREASE BACK TO MVFR THURS MORNING WITH WIND GUST
INCREASING BACK AGAIN.
LONG TERM /THU NIGHT THROUGH MONDAY/...
AS OF 300 PM WED...WITH STRONG UPPER RIDGE BUILDING OVER THE AREA,
THE COVERAGE OF SHRA/TSRA WILL BE LIMITED THRU MUCH OF THE
UPCOMING WEEKEND. HOWEVER WITH LOW LEVELS REMAINING VERY MOIST
BOUTS OF SUB VFR STRATUS AND FOG WILL BE LIKELY LATE NIGHT/EARLY
MORN THRU SUNDAY. MAINLY VFR LATE MORN THRU EVENING HOURS WITH
ONLY SMALL CHC OF SHRA/TSRA THRU THE WEEKEND. A BACK DOOR COLD
FRONT DROPS THRU THE AREA LATE SUNDAY NIGHT OR EARLY MONDAY
BRINGING A POTENTIAL FOR LOW CLOUDS AND FOG BEHIND THE FRONT EARLY
NEXT WEEK.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 1025 AM WEDNESDAY...LATEST SURFACE AND BUOY DATA INDICATE SE
TO SSW WINDS ACROSS THE EASTERN NC WATERS 5-15 KT WITH GUSTS NEAR
20 KT FOR THE OUTER BUOYS 41025/41064. THE SURFACE RIDGE REMAINS
CENTERED OFF THE SOUTHEAST COAST THROUGH THE SHORT TERM. A COASTAL
TROUGH JUST SOUTH OF THE WATERS IS PROGGED TO LIFT ACROSS THE
REGION THIS MORNING. SE WINDS AROUND 5-15 KT WILL BECOME SLY AND
INCREASE TO 15-25 KT WITH HIGHER GUSTS AFTER THE TROUGH LIFTS
ACROSS THE REGION AND CONTINUE THROUGH MUCH OF THE OVERNIGHT. SEAS
CURRENTLY AROUND 3-6 FT WILL BUILD IN RESPONSE TO THE STRONGER SLY
FLOW THROUGH THE DAY...PEAKING AROUND 6-10 FT TONIGHT. STRONGEST
WINDS/SEAS WILL OCCUR OVER THE COASTAL WATERS AND WILL CONTINUE
THE SCA. THE SOUNDS AND RIVERS EXPECTED TO REMAIN JUST BELOW
ADVISORY CRITERIA BUT MAY BE CLOSE ACROSS THE PAMLICO SOUND,
ESPECIALLY IN GUSTS.
LONG TERM /THU NIGHT THROUGH MONDAY/...
AS OF 300 PM WED...SW WINDS AND ELEVATED SEAS WILL GRAD SUBSIDE
THU NIGHT AND FRI AS WEAK FRONT STALLS TO THE NORTH AND SFC HIGH
PRESSURE BUILDS OFF THE SE COAST. THE PRESSURE GRADIENT WITH THE
OFFSHORE HIGH WILL SUPPORT A LIGHT TO MODERATE (10-15 KT) S/SW
FLOW THRU MUCH OF THE UPCOMING WEEKEND WITH SEAS MAINLY 3 TO 5 FT.
A BACKDOOR FRONT DROPS THRU THE MARINE AREA LATE SUNDAY NIGHT OR
EARLY MONDAY WITH WINDS SHIFTING N/NE WHILE MAINTAINING MODERATE
SPEEDS AOB 15 KTS.
&&
.CLIMATE...
EXTREMELY WARM AND HUMID WEATHER FOR DECEMBER WILL DOMINATE THE
REMAINDER OF CHRISTMAS WEEK. THE FOLLOWING ARE RECORD HIGH MAX
TEMPS, AS WELL AS RECORD HIGH MIN TEMPS, FOR 12/23 THROUGH 12/25,
WHEN THE WARMEST TEMPS ARE EXPECTED. ALSO INCLUDED ARE THE ALL-
TIME HIGHS FOR DECEMBER.
RECORD HIGH MAX TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 79/2013 (KEWN ASOS)
CAPE HATTERAS 75/1990 (KHSE ASOS)
GREENVILLE 79/1967 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1990 (COOP NOT KMRH ASOS)
KINSTON 82/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 82/1981 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 63/1990 (KEWN ASOS)
CAPE HATTERAS 66/1990 (KHSE ASOS)
GREENVILLE 61/1990 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 64/2013 (COOP - NOT KMRH ASOS)
KINSTON 65/2013 (COOP- NOT KISO AWOS)
JACKSONVILLE 63/1956 (KNCA AWOS)
RECORD HIGH MAX TEMPS F0R 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 76/1964 (KEWN ASOS)
CAPE HATTERAS 72/1990 (KHSE ASOS)
GREENVILLE 73/1988 (COOP NOT KPGV AWOS)
MOREHEAD CITY 72/1990 (COOP NOT KMRH ASOS)
KINSTON 78/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 74/1990 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 55/2014 (KEWN ASOS)
CAPE HATTERAS 62/1986 (KHSE ASOS)
GREENVILLE 56/1956 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/1956 (COOP - NOT KMRH ASOS)
KINSTON 63/1990 (COOP- NOT KISO AWOS)
JACKSONVILLE 54/2014 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 78/1955 (KEWN ASOS)
CAPE HATTERAS 73/1964 (KHSE ASOS)
GREENVILLE 77/1964 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1974 (COOP NOT KMRH ASOS)
KINSTON 78/1932 (COOP NOT KISO AWOS)
JACKSONVILLE 76/1974 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 63/1964 (KEWN ASOS)
CAPE HATTERAS 61/1964 (KHSE ASOS)
GREENVILLE 59/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/2008 (COOP - NOT KMRH ASOS)
KINSTON 61/1932 (COOP- NOT KISO AWOS)
JACKSONVILLE 61/1987 (KNCA AWOS)
**ALL-TIME RECORD HIGH TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 83/1971 (KEWN ASOS)
CAPE HATTERAS 78/1991 (KHSE ASOS)
GREENVILLE 82/1998 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 79/1998 (COOP - NOT KMRH ASOS)
KINSTON 87/1918 (COOP - NOT KISO AWOS)
JACKSONVILLE 82/1998 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 3 AM EST FRIDAY FOR AMZ150.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK/DAG
SHORT TERM...SK
LONG TERM...RF/BTC
AVIATION...RF/BTC/BM
MARINE...RF/BTC/SK/DAG
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
206 PM EST WED DEC 23 2015
.SYNOPSIS...
NEAR RECORD WARMTH FOR MOST OF THE UPCOMING WEEK DESPITE SOME
FAIRLY CLOUDY CONDITIONS. HIGH CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS TODAY...WITH COVERAGE BECOMING MORE ISOLATED DURING
THURSDAY. DRY MID LEVEL AIR SHOULD SHUT DOWN SHOWER ACTIVITY
FRIDAY AND OVER THE WEEKEND AS HIGH PRESSURE OFF THE SOUTHEAST
COAST CONTINUES TO RIDGE ACROSS THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...PATTERN WILL REMAIN UNCHANGED THROUGH THE
END OF THE PERIOD. BERMUDA HIGH REMAINS OFF THE COAST WITH SOUTH
TO SOUTHEAST LOW LEVEL FLOW CONTINUING TO ADVECT WARM MOIST AIR
INTO THE REGION. ALOFT THE BROAD 5H TROUGH OVER MUCH OF THE CONUS
WILL CONTINUE PUMPING GULF AND PACIFIC MOISTURE OVER THE SOUTHEAST
STATES. AS SUCH PWATS WILL APPROACH 2 INCHES THIS EVENING AND
OVERNIGHT...LEVELS THAT HAVE NOT BEEN PREVIOUSLY OBSERVED IN LATE
DEC. ALL OF THIS MOISTURE WILL INTERACT WITH A SERIES OF WEAK
SHORTWAVES MOVING NORTHEAST FROM THE GULF OF MEXICO THIS EVENING
AND OVERNIGHT. A FEW OF THESE WAVES ARE STRONG ENOUGH TO BE SEEN
ON WATER VAPOR BUT MOST ARE TOO WEAK. IN ADDITION TO THE
SHORTWAVES THERE WILL BE SOME DYNAMICS PROVIDED BY A WEAK 200-300
MB JET. ALTHOUGH IT IS WEAK THIS WILL AT LEAST CONTRIBUTE SOME
ADDITIONAL UPWARD MOTION. THE LACK OF WIDESPREAD/LARGE SCALE
FORCING AND THE MORE CONVECTIVE NATURE OF THE ENVIRONMENT POINTS
TO A PRECIP EVENT WHERE MOST AREAS RECEIVE MEASURABLE RAINFALL
BUT NOT AT THE SAME TIME. WHAT LITTLE SURFACE AND MID LEVEL
INSTABILITY WAS PRESENT TODAY WILL BE LESSENED OVERNIGHT AND THINK
THUNDER CHANCES WILL DIMINISH AS THE AFTERNOON COMES TO AN END.
TEMPERATURES WILL CONTINUE TO BE THE BIGGEST STORY OF THE PERIOD
WITH OVERNIGHT LOWS RUNNING AROUND 10 DEGREES ABOVE NORMAL HIGHS
FOR LATE DEC AND AROUND 30 DEGREES ABOVE LOW TEMPERATURES TYPICAL
FOR THIS TIME OF YEAR...ROUGHLY MID TO UPPER 30S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY...PATTERN CONSISTENCY MORE TYPICAL OF THE WARM
SEASON IN PLACE THROUGH THE PERIOD WITH UPPER RIDGE AND BERMUDA HIGH-
LIKE SURFACE LOCKING INTO PLACE. NO SURPRISE THEN THAT THE
ATMOSPHERE WILL BE PRIMED WITH BOTH COPIOUS WARMTH AND MOISTURE. THE
WARMTH WILL MANIFEST ITSELF AS, WELL, WARMTH. NEAR RECORD VALUES, IN
FACT. THE MOISTURE WILL MOSTLY TAKE FORM OF FAIRLY WIDESPREAD CLOUD
COVER BUT ALSO SOME VERY LOW RAIN CHANCES. THESE LOW RAIN CHANCES
WILL BE FOCUSED ALONG WESTERN ZONES ON THURSDAY AS A WEAK VORT
STREAKS BY COINCIDING WITH A RIBBON OF THE DEEPEST MOISTURE. (THE
OFFSHORE QPF POSSIBLY AFFECTING THE COAST DEPICTED ON THE WRF SEEMS
IMPLAUSIBLE GIVEN THE WARM AIR BEING STABILIZED BY THE CHILLY SSTS).
IT MAY THEN SHIFT TO NORTHERN AND WESTERN ZONES AS A COLD FRONT
BACKDOORS ITS WAY TO THE NC/VA BORDER. OVERALL THOUGH FEEL THAT
FRIDAY MOSTLY RAIN-FREE AS THE RIDGE ALOFT BUILDS WESTWARD PUMPING
HEIGHT RISES INTO THE REGION SUPPRESSING WHAT MAY ALSO BE AN ATTEMPT
AT SEA BREEZE AND WEST WALL CONVECTION SHOWN IN SOME MODELS.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY... MODERATELY HIGHLY AMPLIFIED PATTERN IN PLACE
FOR THE ENTIRE PERIOD. STALWART RIDGE ALOFT HOLDS JUST EAST OF THE
BAHAMAS WHILE CUTOFF UPPER LOW EJECTS FROM THE SOUTHWESTERN U.S.
INTO THE OHIO VALLEY SATURDAY THROUGH MONDAY. TEMPERATURES WILL
CONTINUE THEIR IMPRESSIVE DEVIATIONS FROM CLIMATOLOGY WITH DAYTIME
HIGHS NEARLY 20 DEGREES ABOVE NORMAL AND NIGHTTIME DEVIATIONS OFTEN
EVEN LARGER AS CLOUD COVER LINGERS BENEATH THE SUBSIDENCE INVERSION
BORNE OF THE UPPER RIDGE. RAIN CHANCES ARE BOTH TOUGH TO RULE OUT
WITH SO MUCH LOW LEVEL MOISTURE BUT ALSO HARD TO GET EXCITED ABOUT
DUE TO THE UPPER RIDGE. THE EXCEPTION MAY BE MONDAY WHEN THE RIDGE
GETS BEAT DOWN SUFFICIENTLY FOR SOME HEIGHT FALLS LOCALLY. THEN
AGAIN, THIS USUALLY OCCURS MORE SLOWLY THAN PORTRAYED IN GUIDANCE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...MOST OF THE PRECIP HAS DIED DOWN WITH A FEW EXCEPTIONS.
CEILINGS ARE LIKELY TO BE ALL OVER THE PLACE THIS AFTERNOON...EVENTUALLY
BECOMING ALL IFR SOMETIME TONIGHT. THE HRRR MODEL BRINGS CONVECTION
BACK INTO THE WESTERN TERMINALS THIS EVENING...HOWEVER THINK IT WILL
BE MORE OF A STABLE RAIN OR EVEN DRIZZLE AS WE HEAD THROUGH THE
OVERNIGHT HOURS. MODELS ARE HINTING AT SOME LIFR FOG AND THIS SEEMS
REASONABLE. CLOUD COVER AND THE STRONG SOUTHERLY GRADIENT MAY BE
A HINDERANCE. SOME RAIN ON THURSDAY HOWEVER COVERAGE WILL BE LESS
THAN TODAY.
EXTENDED OUTLOOK...POSSIBLE MVFR TO IFR CONDITIONS IN PCPN AND LOW
CEILINGS FROM THROUGH THURSDAY...OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 2 PM WEDNESDAY...SOUTHERLY FLOW WILL CONTINUE AROUND WEST
SIDE OF THE BERMUDA HIGH THIS AFTERNOON AND OVERNIGHT. COMBINATION
OF SURFACE PRESSURE GRADIENT AND LOW LEVEL JET WILL KEEP SPEEDS
IN THE 15 TO 20 KT RANGE THROUGH THE END OF THE PERIOD. THE
PROLONGED DURATION OF SOUTHERLY FLOW IN CONJUNCTION WITH THE
ELEVATED WIND SPEEDS WILL MAINTAIN SEAS OF 4 TO 7 FT THROUGH THE
END OF THE PERIOD. AS SUCH WILL MAINTAIN THE SCA FOR ALL WATERS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY... PERIOD INITIALIZES WITH A SMALL CRAFT
ADVISORY IN A MODERATELY PINCHED SOUTHWESTERLY GRADIENT FLOW WITH
SOME EMBEDDED ENERGY. A SLIGHT WESTWARD EXTENSION OF A RIDGE AXIS
INTO GA/FL ON THE PART OF THE OFFSHORE HIGH LEADS TO A SLIGHT
WEAKENING OF THE GRADIENT LATER THURSDAY INTO THURSDAY NIGHT AND
FRIDAY. WIND REMAINS MOSTLY SOUTHWESTERLY ON FRIDAY BUT IN A
LIGHTENED STATE. THE RIDGE AXIS SHOULD ALSO DISRUPT THE SWELL
ENERGY A BIT TO HELP FURTHER REDUCE DOMINANT WAVE HEIGHT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY... MUCH MORE OF A WARM SEASON PATTERN IN
PLACE WITH A WEST ATLANTIC HIGH DOMINATING AND A COMPLETE LACK OF
ANY FRONTS. THE MAIN DIFFERENCE PATTERN-WISE WILL BE THAT THE HIGH
WILL BE WEAKER AND FURTHER WEST THAN WHAT IS NORMALLY OBSERVED IN
THE WARM SEASON. AS SUCH WIND SPEEDS MAY WELL BE CAPPED AT 10KT AS
THE DIRECTION REMAINS SOUTH TO SOUTHWESTERLY. SEAS WILL AVERAGE 2
TO 3 AND OCCASIONALLY (WELL OFFSHORE) 4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR AMZ250-252-
254-256-270-274.
&&
$$
NEAR TERM...III
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
127 PM EST WED DEC 23 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH THE WEEKEND. A WEAK
COLD FRONT WILL APPROACH FROM THE NORTH THURSDAY NIGHT THEN STALL
NEAR THE VIRGINIA BORDER FRIDAY. THE FRONT WILL LIFT BACK NORTH
OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1020 AM WEDNESDAY...LATE MORNING UPDATE FOR ONLY MINOR
TWEAKS IN THE NEAR TERM. CONVECTION HAS SHOWN POTENTIAL TO BECOME
SEVERE FOR WESTERN ZONES (DUPLIN/ONSLOW/GREENE/LENOIR COUNTIES)
WHERE SPC MESOANALYSES INDICATE BETTER INSTABILITY. IR SATELLITE
IMAGERY INDICATED WARMING CLOUD TOPS AS THE EARLIER CONVECTION
SHIFTS NORTH ACROSS THE HWY 64 CORRIDOR. A PERIOD OF HEAVY RAIN
AND POSSIBLY GUSTY WINDS WILL STILL BE POSSIBLE INTO EARLY
AFTERNOON WITH SHOWER COVERAGE INCREASING FROM THE SOUTH AND WEST.
THE SYNOPTIC PATTERN PRESENTS AN UPPER TROUGH MOVING INTO THE
PLAINS WITH RIDGING OVER THE ATLANTIC, BRINGING DEEP SW FLOW
ACROSS THE EASTERN CONUS THAT IS TAPPING INTO TROPICAL PACIFIC
MOISTURE BRINGING PWATS AROUND 1.75 INCHES WHICH IS AT OR ABOVE
CLIMATOLOGICAL MAXIMUM FOR LATE DECEMBER. SFC HIGH PRES REMAINS
CENTERED OFFSHORE WITH A COASTAL TROUGH JUST SOUTH OF THE REGION
PROGGED TO LIFT ACROSS THE REGION TODAY. THIS PATTERN WILL
CONTINUE TO BRING PERIODS OF SHOWERS ACROSS THE REGION TODAY WHICH
ARE BEING ENHANCED BY WEAK EMBEDDED SHORTWAVES MOVING THROUGH THE
FLOW ALOFT. COULD SEE A FEW STRONGER STORMS DEVELOP THROUGH THE
AFTERNOON HOURS AS THE AIRMASS DESTABILIZES IN THE PRESENCE OF
STRONG LOW LEVEL SHEAR. HRRR IS FORECASTING MLCAPE AROUND
1000-1500J/KG AND LI`S AROUND -4C WITH 40-50 KT 0-6KM SHEAR AND
0-1KM HELICITY AROUND 200-300 M2/S2 THIS AFTERNOON WITH HIGHEST
VALUES WEST OF HIGHWAY 17. SPC HAS MOST OF THE REGION OUTLOOKED
FOR A MARGINAL RISK OF SEVERE THUNDERSTORMS WITH DAMAGING WIND
GUSTS AND AN ISOLATED TORNADO THE PRIMARY THREAT. PERIODS OF HEAVY
RAINFALL WITH LOCALIZED FLOODING OF POOR DRAINAGE AND LOW LYING
AREA WILL ALSO BE POSSIBLE. EXPECT GUSTY SLY WINDS TO DEVELOP LATE
MORNING THROUGH THE AFTERNOON IN THE WAKE OF THE TROUGH LIFTING
ACROSS THE REGION WHICH COULD BRING GUSTS AROUND 20-30 MPH. TEMPS
WILL BE ALMOST 20 DEGREES ABOVE NORMAL WITH HIGHS EXPECTED IN THE
MID 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS OF 3 AM WEDNESDAY....LITTLE CHANGE IN THE PATTERN TONIGHT WITH
MOIST SW FLOW CONTINUING. A FEW STRONGER STORMS WILL BE POSSIBLE
EARLY IN THE EVENING BUT GENERALLY EXPECT A DECREASE IN COVERAGE
THROUGH THE OVERNIGHT AS SHORTWAVE ENERGY LIFTS NORTH OF THE
REGION AND THE UPPER RIDGE OVER THE WESTERN ATLANTIC BEGINS TO
BUILDS WEST SOME. WILL CONTINUE A DECREASING TREND IN POPS THROUGH
THE OVERNIGHT. MODERATE SLY WINDS WILL BRING VERY MILD OVERNIGHT
TEMPS IN THE UPPER 60S TO 70...WHICH IS ABOUT 30-35 DEGREES ABOVE
NORMAL AND WILL LIKELY BREAK RECORD HIGH MINIMUM TEMPERATURES FOR
THE DAY...SEE CLIMATE SECTION BELOW.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 220 AM WED...BIG STORY WILL BE RECORD BREAKING WARM TEMPS
THROUGH MUCH OF THE PERIOD AS STRONG UPPER RIDGE OVER THE ATLANTIC
BUILDS WEST TOWARD THE COAST INTO THE WEEKEND.
THURSDAY THROUGH CHRISTMAS DAY...COVERAGE OF PRECIPITATION WILL
DROP A BIT FOR THURSDAY AND FRIDAY AS UPR RDG GRAD BUILDS W. FCST
SOUNDINGS FOR THU SHOW SBCAPE VALUES POSSIBLY GREATER THAN 1500
J/KG AND LI`S IN THE -3 TO -5 RANGE DURING THE AFTERNOON ALONG
WITH DECENT SHEAR...HOWEVER LACK OF FORCING MAY LIMIT TSRA
POTENTIAL. A FEW STRONG TO POSS SEVERE STORMS CAN NOT BE RULED
OUT GIVEN THE VERY HIGH INSTAB FOR LATE DEC. LOW LVL
THICKNESS/850 TEMPS PEAK THU AFTN WITH SOME HIGHS TEMPS IN THE
LOWER 80S POSS WHICH WILL LIKELY BREAK NUMEROUS RECORDS AND POSS
SET ALL TIME DEC RECORDS. ON FRI UPR RDG BUILDS CLOSER WHICH WILL
ACT TO SUPPRESS CONVECTION AND WITH MORE SUN TEMPS WILL AGAIN BE
VERY WARM REACHING AROUND 80 AGAIN WARMER SPOTS.
SATURDAY THROUGH SUNDAY...STRONG UPPER LEVEL RIDGE HOLDS ACROSS
THE SOUTHEASTERN UNITED STATES THROUGH THE WEEKEND AS LOW
PRESSURE MOVES FROM THE MISSISSIPPI VALLEY INTO THE GREAT LAKES
REGION. THIS WILL KEEP UNSEASONABLY WARM TEMPERATURES IN PLACE
WITH DAYTIME HIGHS WELL INTO THE 70S SATURDAY AND SUNDAY WITH LOWS
IN THE 60S. THERE WILL BE ONLY A SMALL CHANCE OF SHOWERS EACH DAY
GIVEN THE CONTINUED RATHER MOIST AIRMASS WITH FORECAST
PRECIPITABLE WATER VALUES AOA 1.50 INCHES.
MONDAY THROUGH TUESDAY...UPR RDG WILL BEGIN TO SHIFT BACK E WITH
MDLS SHOWING BACKDOOR FRONT DROPPING INTO THE REGION MON THEN
LIFTING BACK N TUE AHEAD OF STRONGER APPROACHING FRONT. CONT PREV
FCST OF CHC POPS EARLY NEXT WEEK WITH STILL VERY MILD TEMPS IN THE
60S TO LOWER 70S...POSS SOME MID 70S TUE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1 PM WEDNESDAY...HIGH CONFIDENCE OF MVFR CONDITIONS WILL
PERSIST MOST OF THE TAF PERIOD. WITH A MOIST SW FLOW...PERIODS OF
SHOWERS WILL CONTINUE ACROSS THE AREA. SOME STORMS COULD BE
STRONG TO MARGINALLY SEVERE THIS AFTERNOON IF INSTABILITY CAN BE
REALIZED WITH STRONG SHEAR IN PLACE AND SHORTWAVE ENERGY MOVING
ACROSS THE REGION. THESE SHOWERS/THUNDERSTORMS ARE EXPECT TO BRIEFLY
REDUCE VSBYS/CEILINGS. SOUTHERLY WINDS 10-15 KTS WITH GUSTS 20 TO
25 KNOTS REDUCING DOWN TO AROUND 10 KTS OVERNIGHT. FORECASTING
SOUNDING AND GUIDANCE CONTINUES TO SHOW MVFR CEILINGS FOR TONIGHT
AND REDUCING DOWN TO IFR CEILINGS AROUND 7/8Z. CEILINGS ARE
EXPECTED TO INCREASE BACK TO MVFR THURS MORNING WITH WIND GUST
INCREASING BACK AGAIN.
LONG TERM /THU THROUGH SATURDAY/...
AS OF 220 AM WED...COVERAGE OF SHRA/TSRA WILL BE LESS THURSDAY
THROUGH SAT BUT WITH LOW LEVELS REMAINING VERY MOIST BOUTS OF SUB
VFR STRATUS AND FOG WILL BE LIKELY LATE NIGHT/EARLY MORN. MAINLY
VFR LATE MORN THRU EVENING HOURS WITH ONLY SMALL CHC OF SHRA/TSRA
CROSSING. ISOLATED STRONG THUNDERSTORMS WILL BE POSS THU.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 1025 AM WEDNESDAY...LATEST SURFACE AND BUOY DATA INDICATE SE
TO SSW WINDS ACROSS THE EASTERN NC WATERS 5-15 KT WITH GUSTS NEAR
20 KT FOR THE OUTER BUOYS 41025/41064. THE SURFACE RIDGE REMAINS
CENTERED OFF THE SOUTHEAST COAST THROUGH THE SHORT TERM. A COASTAL
TROUGH JUST SOUTH OF THE WATERS IS PROGGED TO LIFT ACROSS THE
REGION THIS MORNING. SE WINDS AROUND 5-15 KT WILL BECOME SLY AND
INCREASE TO 15-25 KT WITH HIGHER GUSTS AFTER THE TROUGH LIFTS
ACROSS THE REGION AND CONTINUE THROUGH MUCH OF THE OVERNIGHT. SEAS
CURRENTLY AROUND 3-6 FT WILL BUILD IN RESPONSE TO THE STRONGER SLY
FLOW THROUGH THE DAY...PEAKING AROUND 6-10 FT TONIGHT. STRONGEST
WINDS/SEAS WILL OCCUR OVER THE COASTAL WATERS AND WILL CONTINUE
THE SCA. THE SOUNDS AND RIVERS EXPECTED TO REMAIN JUST BELOW
ADVISORY CRITERIA BUT MAY BE CLOSE ACROSS THE PAMLICO SOUND,
ESPECIALLY IN GUSTS.
LONG TERM /THU THROUGH SATURDAY/...
AS OF 220 AM WED...SSW WINDS 15 TO 25 KTS WILL CONT THU BETWEEN
HIGH PRESSURE NEAR BERMUDA AND LOW PRESSURE LIFTING NORTHEAST OF
THE GREAT LAKES. SW WINDS WILL GRAD SUBSIDE THU NIGHT AND FRI AS
WEAK FRONT STALLS TO THE NORTH. THE FRONT WILL LIFT BACK N SAT
WITH CONT LIGHT S TO SW FLOW. SEAS WILL REMAIN ELEVATED THU AND
THU NIGH WITH SCA CONT COASTAL WATERS. SEAS WILL PEAK AT AROUND 8
FT OUTER SRN/CNTRL WATERS THU. SEAS WILL SUBSIDE THU NIGHT AND
FRI WITH SCA ENDING NRN WATERS LATE THU NIGHT AND REST OF WATERS
BY MID DAY FRI. SEAS WILL CONT IN THE 3 TO 5 FT RANGE THRU SAT.
&&
.CLIMATE...
EXTREMELY WARM AND HUMID WEATHER FOR DECEMBER WILL DOMINATE THE
REMAINDER OF CHRISTMAS WEEK. THE FOLLOWING ARE RECORD HIGH MAX
TEMPS, AS WELL AS RECORD HIGH MIN TEMPS, FOR 12/23 THROUGH 12/25,
WHEN THE WARMEST TEMPS ARE EXPECTED. ALSO INCLUDED ARE THE ALL-
TIME HIGHS FOR DECEMBER.
RECORD HIGH MAX TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 79/2013 (KEWN ASOS)
CAPE HATTERAS 75/1990 (KHSE ASOS)
GREENVILLE 79/1967 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1990 (COOP NOT KMRH ASOS)
KINSTON 82/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 82/1981 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 63/1990 (KEWN ASOS)
CAPE HATTERAS 66/1990 (KHSE ASOS)
GREENVILLE 61/1990 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 64/2013 (COOP - NOT KMRH ASOS)
KINSTON 65/2013 (COOP- NOT KISO AWOS)
JACKSONVILLE 63/1956 (KNCA AWOS)
RECORD HIGH MAX TEMPS F0R 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 76/1964 (KEWN ASOS)
CAPE HATTERAS 72/1990 (KHSE ASOS)
GREENVILLE 73/1988 (COOP NOT KPGV AWOS)
MOREHEAD CITY 72/1990 (COOP NOT KMRH ASOS)
KINSTON 78/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 74/1990 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 55/2014 (KEWN ASOS)
CAPE HATTERAS 62/1986 (KHSE ASOS)
GREENVILLE 56/1956 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/1956 (COOP - NOT KMRH ASOS)
KINSTON 63/1990 (COOP- NOT KISO AWOS)
JACKSONVILLE 54/2014 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 78/1955 (KEWN ASOS)
CAPE HATTERAS 73/1964 (KHSE ASOS)
GREENVILLE 77/1964 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1974 (COOP NOT KMRH ASOS)
KINSTON 78/1932 (COOP NOT KISO AWOS)
JACKSONVILLE 76/1974 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 63/1964 (KEWN ASOS)
CAPE HATTERAS 61/1964 (KHSE ASOS)
GREENVILLE 59/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/2008 (COOP - NOT KMRH ASOS)
KINSTON 61/1932 (COOP- NOT KISO AWOS)
JACKSONVILLE 61/1987 (KNCA AWOS)
**ALL-TIME RECORD HIGH TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 83/1971 (KEWN ASOS)
CAPE HATTERAS 78/1991 (KHSE ASOS)
GREENVILLE 82/1998 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 79/1998 (COOP - NOT KMRH ASOS)
KINSTON 87/1918 (COOP - NOT KISO AWOS)
JACKSONVILLE 82/1998 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 3 AM EST FRIDAY FOR AMZ150.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK/DAG
SHORT TERM...SK
LONG TERM...RF/DAG
AVIATION...RF/BM
MARINE...RF/SK/DAG
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
115 PM EST WED DEC 23 2015
.SYNOPSIS...A WEDGE FRONT WILL REMAIN QUASI-STATIONARY OVER THE
PIEDMONT EARLY TODAY...THEN BE OVERTAKEN BY A MARITIME WARM FRONT
THAT WILL SURGE ACROSS THE CAROLINAS AND SOUTHEASTERN VIRGINIA THIS
AFTERNOON. ANOMALOUSLY STRONG SUB-TROPICAL HIGH PRESSURE OVER THE
WEST-CENTRAL ATLANTIC OCEAN WILL THEN DIRECT UNSEASONABLY WARM AND
MOIST SOUTHERLY FLOW THROUGHOUT THE SOUTHEASTERN UNITED STATES
THROUGH CHRISTMAS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM WEDNESDAY...
...FLASH FLOOD WATCH CONTINUES ACROSS THE WESTERN PIEDMONT...
DEEP MOIST SOUTHERLY FLOW...CHARACTERIZED BY NEARLY CLIMATOLOGICAL MAX
PW OF 1.8 INCHES AND 850MB DEWPOINTS OF 14-15C...CONTINUES AROUND THE
ANOMALOUSLY STRONG RIDGE OVER THE WESTERN ATLANTIC. A WEDGE FRONT
IS HOLDING FROM CENTRAL VA THROUGH THE NC WESTERN PIEDMONT AND INTO
UPSTATE SC...WHILE A COASTAL WARM FRONT IS BEGINNING TO SURGE INLAND
AS UPPER 60S DEWPOINTS HAVE REACHED THE I-95 CORRIDOR. IN THE WEDGE
AIRMASS...DENSE FOG WILL CONTINUE...PERIODICALLY DISPERSED BY
SHOWERS SPREADING NORTH THROUGH THE PIEDMONT. NEARLY ALL GUIDANCE
SHOWS THE WEDGE FRONT ERODING AND 60S DEWPOINTS ALL THE WAY THROUGH
FORSYTH CO THIS AFTERNOON. MEANWHILE...THE WARM FRONT AND LEADING
EDGE OF WEAKLY UNSTABLE AIR...WITH MLCAPE POTENTIALLY EXCEEDING 500
J/KG...WILL ALSO CONTINUE INLAND...ALTHOUGH WITH RAIN ALMOST
CONTINUOUS IN THE PIEDMONT IT`S STILL A LITTLE UNCLEAR HOW FAR
INLAND THE WARM SECTOR WILL MIX. DEEP LAYER SHEAR WILL BE 45-
50KT...WHICH WILL SUPPORT A SEVERE THREAT OVER THE COASTAL PLAIN
WHERE THE SHEAR/INSTABILITY PARAMETER SPACE IS BEST. LOW-LEVEL IS
ENHANCED BY A 40KT SOUTHWESTERLY LLJ AND SOUTHEASTERLY SURFACE
WIND...ESPECIALLY IN THE VICINITY OF THE WARM FRONT...AND SHERBE
VALUES ARE PROGGED AROUND 1 THROUGH THE PIEDMONT THIS AFTERNOON.
GOING AGAINST THE SEVERE THREAT IS A GENERAL LACK OF A FOCUS...AS A
NOTABLE MCV OVER NORTHERN GA SHOULD MOVE MORE ALONG THE
MOUNTAINS...AND RAP SOUNDINGS MAINTAIN A SMALL CAPPING INVERSION
THROUGH THE AFTERNOON THAT WOULD LIMIT THE ALREADY WEAK MUCAPE.
HOWEVER...THE SPC MARGINAL RISK STILL LOOKS WARRANTED GIVEN THE
ANOMALOUSLY HIGH PW AND UNUSUAL AIRMASS FOR LATE DECEMBER.
THE FLOODING THREAT...WHILE IT HASN`T MATERIALIZED IN THE
WEST...STILL EXISTS GIVEN THE AFOREMENTIONED MCV MOVING UP FROM GA.
THE HRRR SHOWS A LARGE AREA OF PRECIP...INCREASINGLY CONVECTIVE
LOOKING...OVER THE WESTERN PIEDMONT THIS AFTERNOON. IN ADDITION...A
FEW RIVERS...INCLUDING THE ROCKY RIVER AND HAW RIVER...ARE EITHER
EXPERIENCING MINOR FLOODING OR FORECAST TO FLOOD. SO WE WILL
CONTINUE THE FLASH FLOOD WATCH FOR NOW.
TEMPS WILL SLOWLY RISE THROUGH THE 60S IN THE PIEDMONT AND INTO THE
70S IN THE COASTAL PLAIN...WITH MAX VALUES IN THE 65-75 RANGE THIS
AFTERNOON. -22
SHOWERS WILL CONTINUE TO BE A POSSIBILITY TONIGHT...AND LOW
TEMPERATURES WILL STRUGGLE TO DROP OUT OF THE 70S AT MOST
LOCATIONS...AGAIN HAVING A GOOD CHANCE OF MATCHING THE ALL-TIME
WARMEST DECEMBER MINIMUM TEMPERATURE ON RECORD(RDU-69...FAY-69...GSO-
65).
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 355 AM WEDNESDAY...
ON THE WESTERN PERIPHERY OF ANOMALOUSLY STRONG SUB-TROPICAL RIDGING
CENTERED OVER THE WEST-CENTRAL ATLANTIC...SHORTWAVE RIDGING AND
ASSOCIATED HEIGHT RISES ALOFT WILL BUILD BEHIND THE MAIN SHORTWAVE
TROUGH LIFTING INTO EASTERN CANADA. WITH RIDGING ALOFT AND AN
ASSOCIATED PROBABLE CAPPING INVERSION DEPICTED ON NAM BUFR
SOUNDINGS...THE DAY WILL LIKELY BE A DRY ONE...THOUGH DIURNAL
HEATING OF THE UNSEASONABLY WARM (70S TO AROUND 80 IN IN THE I-95
CORRIDOR) AND HUMID BOUNDARY LAYER MAY ALLOW FOR SOME CU TO BYPASS
THE CAP AND GROW INTO ISOLATED SHOWERS/STORMS. IN ADDITION...AN
UPSTREAM QLCS...IN A REGION OF RESIDUALLY STRONG H85 MOISTURE
TRANSPORT DIRECTED INTO THE TN VALLEY...MAY SUPPORT THE EASTWARD
PROGRESSION OF A WEAKENING LONE OF SHOWERS AND STORMS TO CROSS THE
APPALACHIANS AND DRIFT INTO WESTERN NC...INCLUDING THE WESTERN
PIEDMONT EARLY THU NIGHT. INCREASING CINH WITH NOCTURNAL "COOLING"
INTO THE 60S FAVORS A DRY NIGHT OTHERWISE AND ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 410 AM WEDNESDAY...
THE STRONG SUB-TROPICAL RIDGE...WITH ANOMALOUSLY HIGH HEIGHTS AND
PRECIPITABLE WATER VALUES BETWEEN 200-300 PERCENT OF NORMAL FROM THE
SOUTHEASTERN UNITED STATES TO EAST-CENTRAL CANADA...WILL MAINTAIN A
VERY MILD-WARM REGIME ACROSS THE SOUTHEASTERN STATES THROUGHOUT THE
PERIOD...AND A WET ONE PRIMARILY NORTHWEST OF CENTRAL NC...AT LEAST
UNTIL LATE IN THE PERIOD. THE MAIN FORECAST UNCERTAINTY REMAINS THE
POSITIONING OF A WAVY FRONTAL ZONE FORECAST TO MEANDER ACROSS THE
MIDDLE ATLANTIC STATES...AND CONSEQUENTLY HOW MUCH SUPPRESSION OF
THE WARMTH OCCURS EAST OF THE APPALACHIANS...DICTATED BY A BATTLE
BETWEEN THE SUB-TROPICAL RIDGE AND CONFLUENT SPLIT FLOW
ALOFT/UNDERLYING POLAR HIGHS FORECAST TO DEVELOP ACROSS THE GREAT
LAKES AND NEW ENGLAND BY THIS WEEKEND.
THE TIMING OF POTENTIAL COLD FRONTAL SURGES INTO NC...IF THEY
OCCUR...ARE FAVORED LATE FRI NIGHT-SAT...AND AGAIN SUN NIGHT-
MON...WITH THE FORMER APPEARING INCREASINGLY UNLIKELY TO AFFECT
CENTRAL NC. OTHERWISE UNSEASONABLY MILD-WARM AND HUMID CONDITIONS IN
DEEP SOUTHERLY FLOW AROUND THE SUB-TROPICAL RIDGE WILL PREVAIL. THE
PRIMARY BRANCH OF THE NORTHERN STREAM WILL BE BLOCKED TO THE NW BY
THE SUB-TROPICAL RIDGING...SO FORCING FOR ASCENT AND ASSOCIATED
PRECIPITATION CHANCES WILL REMAIN LOW (GENERALLY AOB 20 PERCENT) AND
INSTEAD DRIVEN BY LOWER AMPLITUDE SOUTHERN STREAM PERTURBATIONS AND
ASSOCIATED SURGES OF LOW LEVEL THETA-E ADVECTION AND BRIEF EROSION
OF A CAPPING INVERSION FRI-SAT...WITH SAID CAPPING MORE LIKELY TO BE
OVERCOME BY DIURNAL HEATING IN AN AIRMASS MORE CHARACTERISTIC OF
APRIL-MAY THAN LATE DECEMBER.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 115 PM WEDNESDAY...
POOR AVIATION CONDITIONS WILL CONTINUE THROUGH THE TAF PERIOD WITH
MOIST SOUTHERLY FLOW AND NUMEROUS TO WIDESPREAD SHOWERS THROUGH THIS
EVENING. A WARM FRONT PROGRESSING NORTHWEST THROUGH THE AREA WILL
LIFT CEILINGS TO MVFR LEVELS IN THE EAST...MOST LIKELY AT
KFAY/KRWI...WITH LOWER CEILINGS IN THE LIFR/IFR CEILINGS TO HANG ON
AT KGSO/KINT. WINDS WILL GUST TO 20-25KT...MAINLY AT
KRDU/KRWI/KFAY...A FEW STRONG STORMS COULD PRODUCE LOCALLY HIGHER
GUSTS WITH HEAVY RAIN. SHOWERS WILL GENERALLY LESSEN IN COVERAGE
OVERNIGHT...WITH CEILINGS LIKELY TO LOWER TO IFR OR LIFR AGAIN.
SOME GUIDANCE INDICATES FOG...BUT WINDS WILL STAY UP IN THE 8-12KT
RANGE...WHICH SHOULD KEEP VSBYS AT LEAST 3SM. SOME SMALL
IMPROVEMENTS WIN CONDITIONS WILL BE POSSIBLE ON THURSDAY
WITH LESS PRECIP COVERAGE...THOUGH IFR AND MVFR CONDITIONS WILL
CONTINUE TO PREVAIL.
OUTLOOK...WITH DEEP AND MOIST SOUTHWESTERLY FLOW CONTINUING THIS
WEEKEND...PERIODS OF POOR AVIATION CONDITIONS WILL
PERSIST...ESPECIALLY OVERNIGHT.
&&
.CLIMATE...
HERE ARE THE AREA RECORD MAXIMUMS AND HIGH MINIMUMS FOR DECEMBER 24TH
AND 25TH. RECORDS HAVE BEEN KEPT IN THE GREENSBORO AREA SINCE
1903... IN THE RALEIGH AREA SINCE 1887... AND IN THE FAYETTEVILLE
AREA SINCE 1910.
DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)
DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...2
NEAR TERM...CBL/22
SHORT TERM...2
LONG TERM...2
AVIATION...22
CLIMATE...HARTFIELD/BLAES
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1151 AM EST WED DEC 23 2015
.SYNOPSIS...
NEAR RECORD WARMTH FOR MOST OF THE UPCOMING WEEK DESPITE SOME
FAIRLY CLOUDY CONDITIONS. HIGH CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS TODAY...WITH COVERAGE BECOMING MORE ISOLATED DURING
THURSDAY. DRY MID LEVEL AIR SHOULD SHUT DOWN SHOWER ACTIVITY
FRIDAY AND OVER THE WEEKEND AS HIGH PRESSURE OFF THE SOUTHEAST
COAST CONTINUES TO RIDGE ACROSS THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...ACTIVE PATTERN CONTINUES TODAY WITH
BERMUDA HIGH CONTINUING LOW LEVEL SOUTHERLY FLOW AND BROAD 5H
TROUGH AXIS TO THE WEST ENSURING FLOW ALOFT REMAINS SOUTHWEST.
THE RESULT IS DEEP MOISTURE OVER THE SOUTHEAST. PWATS IN FORECAST
SOUNDINGS APPROACH 2 INCHES THIS EVENING AND THE 12Z FLIGHT FROM
CHS REPORTED A PWAT OF 1.86...CLOSE TO 0.30 INCH ABOVE THE
PREVIOUS HIGH FOR THIS DATE. IN ADDITION TO THE ABUNDANT MOISTURE
THERE WILL BE A SERIES OF WEAK SHORTWAVES MOVING THROUGH THE FLOW
ALOFT. GUIDANCE ALSO SHOWS A WEAK JET STREAK IN THE 200-300 MB
LAYER WHICH MAY ENHANCE LIFT LATER THIS AFTERNOON AND EVENING.
IN ADDITION TO THE DYNAMICS THERE IS SOME SURFACE BASED
INSTABILITY. CAPE WILL PEAK AROUND 1500 J/KG BUT INSTABILITY
WITHIN REGIONS FAVORED FOR DEEPER CONVECTION AND LIGHTNING IS
LIMITED. HELD ONTO ISOLATED THUNDER BUT MOST AREAS ARE NOT LIKELY
TO EXPERIENCE ANY. ALTHOUGH A HIGH POP IS WARRANTED TODAY AND
TONIGHT COVERAGE WILL BE LIMITED AT ANY ONE TIME GIVEN THE
CONVECTIVE NATURE OF THE PRECIP. STRONG LOW LEVEL JET IN PLACE
TODAY WITH WINDS OF 30 TO 35 KT AROUND 1K FT. THUS FAR THE STABLE
SURFACE LAYER HAS PREVENTED STRONGER WINDS FROM BEING MIXED DOWN
BUT CANNOT RULE OUT AN ISOLATED STRONG/SEVERE STORM OR TWO IN THE
AFTERNOON. TEMPERATURES CONTINUE TO RUN WELL ABOVE CLIMO WITH
HIGHS IN THE MID 70S EXPECT ACROSS MUCH OF THE AREA.
DISCUSSION FROM 630 THIS MORNING FOLLOWS:
LATEST LOCAL AND MOSAIC RADAR DATA INDICATES PCPN CONTINUES TO
STREAM UP TO THE NNE ACROSS THE CAROLINAS. THIS IS IN RESPONSE TO
A MIDLEVEL S/W TROF LIFTING N TO NE WITHIN STRONG MID- LEVEL SSW
FLOW. THE BEST OR MAIN DYNAMICS FROM THIS S/W TROF STAY WEST OF
THE ILM CWA TODAY...BUT MODELS INDICATE THE TRAILING MID- LEVEL
SHEARED AXIS WILL MAKE ITS WAY TO THE CAROLINA COASTS BY LATE THIS
EVENING. DEEP GULF OF MEXICO AND ATLANTIC MOISTURE WILL CONTINUE
TO PUMP ACROSS THE ILM CWA WITH PROGGED PWS IN THE 1.5 TO 2.00
INCH RANGE. TO PUT IT ALL TOGETHER...THE FA WILL BE UNDER THE
LIKELY TO CATEGORICAL POP THREAT FROM SHOWERS AND EMBEDDED
ISOLATED THUNDERSTORMS TODAY THRU THIS EVENING. AVBL CAPE OF 1K TO
POSSIBLY 1.25K WILL BE LOW ALTHOUGH BETTER THAN YESTERDAY...AND
WITH PROGGED LAPSE RATES REMAINING SUSPECT...HAVE KEPT THE TSTORM
THREAT TO ISOLATED AT BEST FOR NOW.
NO FLOOD WATCHES ARE FORECAST FOR THE ILM CWA. HOWEVER...ANY
TRAINING OF HEAVY SHOWERS OVER AREAS RECEIVING A GOOD DOSE OF
RAINFALL FROM TUESDAY...COULD RESULT IN PONDING OF WATER
ESPECIALLY ACROSS LOW LYING AREAS AND PRONE ROADWAYS. WILL
HIGHLIGHT THIS IN THE HAZARDOUS WEATHER OUTLOOK.
TEMPS WILL CONTINUE TO RUN 15 TO 25+ DEGREES ABOVE NORMAL.
TODAYS HIGHS IN THE MID TO UPPER 70S AND TONIGHTS LOWS IN THE MID
TO UPPER 60S. THIS SOUNDS MORE LIKE A MID FALL OR MID SPRING TEMP
FORECAST. OF NOTE...NORMAL HIGHS ARE IN THE MID TO UPPER 50S AND
NORMAL LOWS ARE IN LOW TO MID 30S.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM WEDNESDAY...PATTERN CONSISTENCY MORE TYPICAL OF THE WARM
SEASON IN PLACE THROUGH THE PERIOD WITH UPPER RIDGE AND BERMUDA HIGH-
LIKE SURFACE LOCKING INTO PLACE. NO SURPRISE THEN THAT THE
ATMOSPHERE WILL BE PRIMED WITH BOTH COPIOUS WARMTH AND MOISTURE. THE
WARMTH WILL MANIFEST ITSELF AS, WELL, WARMTH. NEAR RECORD VALUES, IN
FACT. THE MOISTURE WILL MOSTLY TAKE FORM OF FAIRLY WIDESPREAD CLOUD
COVER BUT ALSO SOME VERY LOW RAIN CHANCES. THESE LOW RAIN CHANCES
WILL BE FOCUSED ALONG WESTERN ZONES ON THURSDAY AS A WEAK VORT
STREAKS BY COINCIDING WITH A RIBBON OF THE DEEPEST MOISTURE. (THE
OFFSHORE QPF POSSIBLY AFFECTING THE COAST DEPICTED ON THE WRF SEEMS
IMPLAUSIBLE GIVEN THE WARM AIR BEING STABILIZED BY THE CHILLY SSTS).
IT MAY THEN SHIFT TO NORTHERN AND WESTERN ZONES AS A COLD FRONT
BACKDOORS ITS WAY TO THE NC/VA BORDER. OVERALL THOUGH FEEL THAT
FRIDAY MOSTLY RAIN-FREE AS THE RIDGE ALOFT BUILDS WESTWARD PUMPING
HEIGHT RISES INTO THE REGION SUPPRESSING WHAT MAY ALSO BE AN ATTEMPT
AT SEA BREEZE AND WEST WALL CONVECTION SHOWN IN SOME MODELS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY... MODERATELY HIGHLY AMPLIFIED PATTERN IN PLACE
FOR THE ENTIRE PERIOD. STALWART RIDGE ALOFT HOLDS JUST EAST OF THE
BAHAMAS WHILE CUTOFF UPPER LOW EJECTS FROM THE SOUTHWESTERN U.S.
INTO THE OHIO VALLEY SATURDAY THROUGH MONDAY. TEMPERATURES WILL
CONTINUE THEIR IMPRESSIVE DEVIATIONS FROM CLIMATOLOGY WITH DAYTIME
HIGHS NEARLY 20 DEGREES ABOVE NORMAL AND NIGHTTIME DEVIATIONS OFTEN
EVEN LARGER AS CLOUD COVER LINGERS BENEATH THE SUBSIDENCE INVERSION
BORNE OF THE UPPER RIDGE. RAIN CHANCES ARE BOTH TOUGH TO RULE OUT
WITH SO MUCH LOW LEVEL MOISTURE BUT ALSO HARD TO GET EXCITED ABOUT
DUE TO THE UPPER RIDGE. THE EXCEPTION MAY BE MONDAY WHEN THE RIDGE
GETS BEAT DOWN SUFFICIENTLY FOR SOME HEIGHT FALLS LOCALLY. THEN
AGAIN, THIS USUALLY OCCURS MORE SLOWLY THAN PORTRAYED IN GUIDANCE.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 18Z...MOST OF THE PRECIP HAS DIED DOWN WITH A FEW EXCEPTIONS.
CEILINGS ARE LIKELY TO BE ALL OVER THE PLACE THIS AFTERNOON...EVENTUALLY
BECOMING ALL IFR SOMETIME TONIGHT. THE HRRR MODEL BRINGS CONVECTION
BACK INTO THE WESTERN TERMINALS THIS EVENING...HOWEVER THINK IT WILL
BE MORE OF A STABLE RAIN OR EVEN DRIZZLE AS WE HEAD THROUGH THE
OVERNIGHT HOURS. MODELS ARE HINTING AT SOME LIFR FOG AND THIS SEEMS
REASONABLE. CLOUD COVER AND THE STRONG SOUTHERLY GRADIENT MAY BE
A HINDERANCE. SOME RAIN ON THURSDAY HOWEVER COVERAGE WILL BE LESS
THAN TODAY.
EXTENDED OUTLOOK...POSSIBLE MVFR TO IFR CONDITIONS IN PCPN AND LOW
CEILINGS FROM THROUGH THURSDAY...OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...SCA CONTINUES FOR ALL ZONES WITH
CONTINUED AND INCREASING SOUTHERLY FLOW BUILDING SEAS OVER 6 FT
ACROSS PORTIONS OF ALL MARINE ZONES. BERMUDA HIGH REMAINS THE MAIN
SURFACE FEATURE...KEEPING WINDS FROM THE SOUTH. COMBINATION OF
GRADIENT AND LOW LEVEL JET IS KEEPING SPEEDS IN THE 15 TO 20 KT
RANGE THROUGH THE PERIOD. ONLY MINIMAL CHANGES REQUIRED FOR
MORNING UPDATE.
DISCUSSION FROM 630 THIS MORNING FOLLOWS:
SMALL CRAFT ADVISORY CONDITIONS EXPECTED THRU THIS PERIOD. SFC
PRESSURE PATTERN THRU TONIGHT TO YIELD SSE-S WIND DIRECTIONS THIS
MORNING...BECOMING S-SSW BY MIDDAY AND CONTINUING THRU TONIGHT. A
TIGHTENING SFC PG WILL DEVELOP ACROSS THE LOCAL WATERS EARLY
TODAY...AND WILL REMAIN TIGHTENED THRU TONIGHT. THIS WILL YIELD 10
TO 20 KT SUSTAINED WIND SPEEDS THIS MORNING THAT COULD
OCCASIONALLY REACH 15 TO 25 KT FROM MIDDAY THROUGH THIS EVENING.
IN ADDITION...GUSTS COULD APPROACH 30 KT ESPECIALLY OVER SSTS THAT
ARE WELL INTO THE 60S. LOCAL SSTS HAVE ALREADY SHOWN AN INCREASE
FROM 24 HRS AGO DUE TO THE ONSHORE FLOW WITH LOW 60S COMMON NOW.
EXPECT THIS SLOW INCREASING TREND TO CONTINUE WITH LOW TO MID 60S
BECOMING MORE COMMON BY EARLY THU. AS A RESULT...SEA FOG
DEVELOPMENT SHOULD NOT BE AN ISSUE DURING THIS TIME PERIOD.
SIGNIFICANT SEAS WILL BUILD TO 4 TO 7 FT TODAY...AND PEAK 5 TO
8 FT LATE THIS AFTN THRU TONIGHT. THE 8 FOOTERS WILL PRIMARILY
OCCUR OVER THE WATERS OFF CAPE FEAR. WIND DRIVEN WAVES AT 6 TO 7
SECOND PERIODS WILL DOMINATE THE SEAS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY... PERIOD INITIALIZES WITH A SMALL CRAFT
ADVISORY IN A MODERATELY PINCHED SOUTHWESTERLY GRADIENT FLOW WITH
SOME EMBEDDED ENERGY. A SLIGHT WESTWARD EXTENSION OF A RIDGE AXIS
INTO GA/FL ON THE PART OF THE OFFSHORE HIGH LEADS TO A SLIGHT
WEAKENING OF THE GRADIENT LATER THURSDAY INTO THURSDAY NIGHT AND
FRIDAY. WIND REMAINS MOSTLY SOUTHWESTERLY ON FRIDAY BUT IN A
LIGHTENED STATE. THE RIDGE AXIS SHOULD ALSO DISRUPT THE SWELL
ENERGY A BIT TO HELP FURTHER REDUCE DOMINANT WAVE HEIGHT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY... MUCH MORE OF A WARM SEASON PATTERN IN
PLACE WITH A WEST ATLANTIC HIGH DOMINATING AND A COMPLETE LACK OF
ANY FRONTS. THE MAIN DIFFERENCE PATTERN-WISE WILL BE THAT THE HIGH
WILL BE WEAKER AND FURTHER WEST THAN WHAT IS NORMALLY OBSERVED IN
THE WARM SEASON. AS SUCH WIND SPEEDS MAY WELL BE CAPPED AT 10KT AS
THE DIRECTION REMAINS SOUTH TO SOUTHWESTERLY. SEAS WILL AVERAGE 2
TO 3 AND OCCASIONALLY (WELL OFFSHORE) 4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR AMZ250-252-
254-256-270-274.
&&
$$
NEAR TERM...III
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1045 AM EST WED DEC 23 2015
.SYNOPSIS...
NEAR RECORD WARMTH FOR MOST OF THE UPCOMING WEEK DESPITE SOME
FAIRLY CLOUDY CONDITIONS. HIGH CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS TODAY...WITH COVERAGE BECOMING MORE ISOLATED DURING
THURSDAY. DRY MID LEVEL AIR SHOULD SHUT DOWN SHOWER ACTIVITY
FRIDAY AND OVER THE WEEKEND AS HIGH PRESSURE OFF THE SOUTHEAST
COAST CONTINUES TO RIDGE ACROSS THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...ACTIVE PATTERN CONTINUES TODAY WITH
BERMUDA HIGH CONTINUING LOW LEVEL SOUTHERLY FLOW AND BROAD 5H
TROUGH AXIS TO THE WEST ENSURING FLOW ALOFT REMAINS SOUTHWEST.
THE RESULT IS DEEP MOISTURE OVER THE SOUTHEAST. PWATS IN FORECAST
SOUNDINGS APPROACH 2 INCHES THIS EVENING AND THE 12Z FLIGHT FROM
CHS REPORTED A PWAT OF 1.86...CLOSE TO 0.30 INCH ABOVE THE
PREVIOUS HIGH FOR THIS DATE. IN ADDITION TO THE ABUNDANT MOISTURE
THERE WILL BE A SERIES OF WEAK SHORTWAVES MOVING THROUGH THE FLOW
ALOFT. GUIDANCE ALSO SHOWS A WEAK JET STREAK IN THE 200-300 MB
LAYER WHICH MAY ENHANCE LIFT LATER THIS AFTERNOON AND EVENING.
IN ADDITION TO THE DYNAMICS THERE IS SOME SURFACE BASED
INSTABILITY. CAPE WILL PEAK AROUND 1500 J/KG BUT INSTABILITY
WITHIN REGIONS FAVORED FOR DEEPER CONVECTION AND LIGHTNING IS
LIMITED. HELD ONTO ISOLATED THUNDER BUT MOST AREAS ARE NOT LIKELY
TO EXPERIENCE ANY. ALTHOUGH A HIGH POP IS WARRANTED TODAY AND
TONIGHT COVERAGE WILL BE LIMITED AT ANY ONE TIME GIVEN THE
CONVECTIVE NATURE OF THE PRECIP. STRONG LOW LEVEL JET IN PLACE
TODAY WITH WINDS OF 30 TO 35 KT AROUND 1K FT. THUS FAR THE STABLE
SURFACE LAYER HAS PREVENTED STRONGER WINDS FROM BEING MIXED DOWN
BUT CANNOT RULE OUT AN ISOLATED STRONG/SEVERE STORM OR TWO IN THE
AFTERNOON. TEMPERATURES CONTINUE TO RUN WELL ABOVE CLIMO WITH
HIGHS IN THE MID 70S EXPECT ACROSS MUCH OF THE AREA.
DISCUSSION FROM 630 THIS MORNING FOLLOWS:
LATEST LOCAL AND MOSAIC RADAR DATA INDICATES PCPN CONTINUES TO
STREAM UP TO THE NNE ACROSS THE CAROLINAS. THIS IS IN RESPONSE TO
A MIDLEVEL S/W TROF LIFTING N TO NE WITHIN STRONG MID- LEVEL SSW
FLOW. THE BEST OR MAIN DYNAMICS FROM THIS S/W TROF STAY WEST OF
THE ILM CWA TODAY...BUT MODELS INDICATE THE TRAILING MID- LEVEL
SHEARED AXIS WILL MAKE ITS WAY TO THE CAROLINA COASTS BY LATE THIS
EVENING. DEEP GULF OF MEXICO AND ATLANTIC MOISTURE WILL CONTINUE
TO PUMP ACROSS THE ILM CWA WITH PROGGED PWS IN THE 1.5 TO 2.00
INCH RANGE. TO PUT IT ALL TOGETHER...THE FA WILL BE UNDER THE
LIKELY TO CATEGORICAL POP THREAT FROM SHOWERS AND EMBEDDED
ISOLATED THUNDERSTORMS TODAY THRU THIS EVENING. AVBL CAPE OF 1K TO
POSSIBLY 1.25K WILL BE LOW ALTHOUGH BETTER THAN YESTERDAY...AND
WITH PROGGED LAPSE RATES REMAINING SUSPECT...HAVE KEPT THE TSTORM
THREAT TO ISOLATED AT BEST FOR NOW.
NO FLOOD WATCHES ARE FORECAST FOR THE ILM CWA. HOWEVER...ANY
TRAINING OF HEAVY SHOWERS OVER AREAS RECEIVING A GOOD DOSE OF
RAINFALL FROM TUESDAY...COULD RESULT IN PONDING OF WATER
ESPECIALLY ACROSS LOW LYING AREAS AND PRONE ROADWAYS. WILL
HIGHLIGHT THIS IN THE HAZARDOUS WEATHER OUTLOOK.
TEMPS WILL CONTINUE TO RUN 15 TO 25+ DEGREES ABOVE NORMAL.
TODAYS HIGHS IN THE MID TO UPPER 70S AND TONIGHTS LOWS IN THE MID
TO UPPER 60S. THIS SOUNDS MORE LIKE A MID FALL OR MID SPRING TEMP
FORECAST. OF NOTE...NORMAL HIGHS ARE IN THE MID TO UPPER 50S AND
NORMAL LOWS ARE IN LOW TO MID 30S.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM WEDNESDAY...PATTERN CONSISTENCY MORE TYPICAL OF THE WARM
SEASON IN PLACE THROUGH THE PERIOD WITH UPPER RIDGE AND BERMUDA HIGH-
LIKE SURFACE LOCKING INTO PLACE. NO SURPRISE THEN THAT THE
ATMOSPHERE WILL BE PRIMED WITH BOTH COPIOUS WARMTH AND MOISTURE. THE
WARMTH WILL MANIFEST ITSELF AS, WELL, WARMTH. NEAR RECORD VALUES, IN
FACT. THE MOISTURE WILL MOSTLY TAKE FORM OF FAIRLY WIDESPREAD CLOUD
COVER BUT ALSO SOME VERY LOW RAIN CHANCES. THESE LOW RAIN CHANCES
WILL BE FOCUSED ALONG WESTERN ZONES ON THURSDAY AS A WEAK VORT
STREAKS BY COINCIDING WITH A RIBBON OF THE DEEPEST MOISTURE. (THE
OFFSHORE QPF POSSIBLY AFFECTING THE COAST DEPICTED ON THE WRF SEEMS
IMPLAUSIBLE GIVEN THE WARM AIR BEING STABILIZED BY THE CHILLY SSTS).
IT MAY THEN SHIFT TO NORTHERN AND WESTERN ZONES AS A COLD FRONT
BACKDOORS ITS WAY TO THE NC/VA BORDER. OVERALL THOUGH FEEL THAT
FRIDAY MOSTLY RAIN-FREE AS THE RIDGE ALOFT BUILDS WESTWARD PUMPING
HEIGHT RISES INTO THE REGION SUPPRESSING WHAT MAY ALSO BE AN ATTEMPT
AT SEA BREEZE AND WEST WALL CONVECTION SHOWN IN SOME MODELS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY... MODERATELY HIGHLY AMPLIFIED PATTERN IN PLACE
FOR THE ENTIRE PERIOD. STALWART RIDGE ALOFT HOLDS JUST EAST OF THE
BAHAMAS WHILE CUTOFF UPPER LOW EJECTS FROM THE SOUTHWESTERN U.S.
INTO THE OHIO VALLEY SATURDAY THROUGH MONDAY. TEMPERATURES WILL
CONTINUE THEIR IMPRESSIVE DEVIATIONS FROM CLIMATOLOGY WITH DAYTIME
HIGHS NEARLY 20 DEGREES ABOVE NORMAL AND NIGHTTIME DEVIATIONS OFTEN
EVEN LARGER AS CLOUD COVER LINGERS BENEATH THE SUBSIDENCE INVERSION
BORNE OF THE UPPER RIDGE. RAIN CHANCES ARE BOTH TOUGH TO RULE OUT
WITH SO MUCH LOW LEVEL MOISTURE BUT ALSO HARD TO GET EXCITED ABOUT
DUE TO THE UPPER RIDGE. THE EXCEPTION MAY BE MONDAY WHEN THE RIDGE
GETS BEAT DOWN SUFFICIENTLY FOR SOME HEIGHT FALLS LOCALLY. THEN
AGAIN, THIS USUALLY OCCURS MORE SLOWLY THAN PORTRAYED IN GUIDANCE.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...THE HRRR MODEL INITIALIZED REASONABLY WELL AND BRINGS
THE FOCUS OF THE PRECIP TO THE COAST BY LATE MORNING. CEILINGS ARE
A BIT ALL OVER THE PLACE...AS WELL AS THE VISIBILITIES IN THE HEAVIER
PRECIP. CEILINGS TODAY WILL BOUNCE FROM IFR TO VFR WITH VISIBILITIES
BRIEFLY IFR IN THE HEAVIER EMBEDDED CONVECTION. MID AND HIGH LEVEL
MOISTURE WILL CONTINUE THROUGH THE END OF THE FORECAST PERIOD. THE
SOUTHERLY GRADIENT WILL REMAIN TIGHT...WITH GUST TO 20 KTS EXPECTED
AT ANY TIME DURING THE NEXT 24 HOURS. A RUMBLE OF THUNDER CAN NOT
BE RULED OUT.
EXTENDED OUTLOOK...POSSIBLE MVFR TO IFR CONDITIONS IN PCPN AND LOW
CEILINGS FROM THROUGH THURSDAY...OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...SCA CONTINUES FOR ALL ZONES WITH
CONTINUED AND INCREASING SOUTHERLY FLOW BUILDING SEAS OVER 6 FT
ACROSS PORTIONS OF ALL MARINE ZONES. BERMUDA HIGH REMAINS THE MAIN
SURFACE FEATURE...KEEPING WINDS FROM THE SOUTH. COMBINATION OF
GRADIENT AND LOW LEVEL JET IS KEEPING SPEEDS IN THE 15 TO 20 KT
RANGE THROUGH THE PERIOD. ONLY MINIMAL CHANGES REQUIRED FOR
MORNING UPDATE.
DISCUSSION FROM 630 THIS MORNING FOLLOWS:
SMALL CRAFT ADVISORY CONDITIONS EXPECTED THRU THIS PERIOD. SFC
PRESSURE PATTERN THRU TONIGHT TO YIELD SSE-S WIND DIRECTIONS THIS
MORNING...BECOMING S-SSW BY MIDDAY AND CONTINUING THRU TONIGHT. A
TIGHTENING SFC PG WILL DEVELOP ACROSS THE LOCAL WATERS EARLY
TODAY...AND WILL REMAIN TIGHTENED THRU TONIGHT. THIS WILL YIELD 10
TO 20 KT SUSTAINED WIND SPEEDS THIS MORNING THAT COULD
OCCASIONALLY REACH 15 TO 25 KT FROM MIDDAY THROUGH THIS EVENING.
IN ADDITION...GUSTS COULD APPROACH 30 KT ESPECIALLY OVER SSTS THAT
ARE WELL INTO THE 60S. LOCAL SSTS HAVE ALREADY SHOWN AN INCREASE
FROM 24 HRS AGO DUE TO THE ONSHORE FLOW WITH LOW 60S COMMON NOW.
EXPECT THIS SLOW INCREASING TREND TO CONTINUE WITH LOW TO MID 60S
BECOMING MORE COMMON BY EARLY THU. AS A RESULT...SEA FOG
DEVELOPMENT SHOULD NOT BE AN ISSUE DURING THIS TIME PERIOD.
SIGNIFICANT SEAS WILL BUILD TO 4 TO 7 FT TODAY...AND PEAK 5 TO
8 FT LATE THIS AFTN THRU TONIGHT. THE 8 FOOTERS WILL PRIMARILY
OCCUR OVER THE WATERS OFF CAPE FEAR. WIND DRIVEN WAVES AT 6 TO 7
SECOND PERIODS WILL DOMINATE THE SEAS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY... PERIOD INITIALIZES WITH A SMALL CRAFT
ADVISORY IN A MODERATELY PINCHED SOUTHWESTERLY GRADIENT FLOW WITH
SOME EMBEDDED ENERGY. A SLIGHT WESTWARD EXTENSION OF A RIDGE AXIS
INTO GA/FL ON THE PART OF THE OFFSHORE HIGH LEADS TO A SLIGHT
WEAKENING OF THE GRADIENT LATER THURSDAY INTO THURSDAY NIGHT AND
FRIDAY. WIND REMAINS MOSTLY SOUTHWESTERLY ON FRIDAY BUT IN A
LIGHTENED STATE. THE RIDGE AXIS SHOULD ALSO DISRUPT THE SWELL
ENERGY A BIT TO HELP FURTHER REDUCE DOMINANT WAVE HEIGHT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY... MUCH MORE OF A WARM SEASON PATTERN IN
PLACE WITH A WEST ATLANTIC HIGH DOMINATING AND A COMPLETE LACK OF
ANY FRONTS. THE MAIN DIFFERENCE PATTERN-WISE WILL BE THAT THE HIGH
WILL BE WEAKER AND FURTHER WEST THAN WHAT IS NORMALLY OBSERVED IN
THE WARM SEASON. AS SUCH WIND SPEEDS MAY WELL BE CAPPED AT 10KT AS
THE DIRECTION REMAINS SOUTH TO SOUTHWESTERLY. SEAS WILL AVERAGE 2
TO 3 AND OCCASIONALLY (WELL OFFSHORE) 4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR AMZ250-252-
254-256-270-274.
&&
$$
NEAR TERM...III
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...DL
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1040 AM EST WED DEC 23 2015
.SYNOPSIS...A WEDGE FRONT WILL REMAIN QUASI-STATIONARY OVER THE
PIEDMONT EARLY TODAY...THEN BE OVERTAKEN BY A MARITIME WARM FRONT
THAT WILL SURGE ACROSS THE CAROLINAS AND SOUTHEASTERN VIRGINIA THIS
AFTERNOON. ANOMALOUSLY STRONG SUB-TROPICAL HIGH PRESSURE OVER THE
WEST-CENTRAL ATLANTIC OCEAN WILL THEN DIRECT UNSEASONABLY WARM AND
MOIST SOUTHERLY FLOW THROUGHOUT THE SOUTHEASTERN UNITED STATES
THROUGH CHRISTMAS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1040 AM WEDNESDAY...
...FLASH FLOOD WATCH CONTINUES ACROSS THE WESTERN PIEDMONT...
DEEP MOIST SOUTHERLY FLOW...CHARACTERIZED BY NEARLY CLIMATOLOGICAL MAX
PW OF 1.8 INCHES AND 850MB DEWPOINTS OF 14-15C...CONTINUES AROUND THE
ANOMALOUSLY STRONG RIDGE OVER THE WESTERN ATLANTIC. A WEDGE FRONT
IS HOLDING FROM CENTRAL VA THROUGH THE NC WESTERN PIEDMONT AND INTO
UPSTATE SC...WHILE A COASTAL WARM FRONT IS BEGINNING TO SURGE INLAND
AS UPPER 60S DEWPOINTS HAVE REACHED THE I-95 CORRIDOR. IN THE WEDGE
AIRMASS...DENSE FOG WILL CONTINUE...PERIODICALLY DISPERSED BY
SHOWERS SPREADING NORTH THROUGH THE PIEDMONT. NEARLY ALL GUIDANCE
SHOWS THE WEDGE FRONT ERODING AND 60S DEWPOINTS ALL THE WAY THROUGH
FORSYTH CO THIS AFTERNOON. MEANWHILE...THE WARM FRONT AND LEADING
EDGE OF WEAKLY UNSTABLE AIR...WITH MLCAPE POTENTIALLY EXCEEDING 500
J/KG...WILL ALSO CONTINUE INLAND...ALTHOUGH WITH RAIN ALMOST
CONTINUOUS IN THE PIEDMONT IT`S STILL A LITTLE UNCLEAR HOW FAR
INLAND THE WARM SECTOR WILL MIX. DEEP LAYER SHEAR WILL BE 45-
50KT...WHICH WILL SUPPORT A SEVERE THREAT OVER THE COASTAL PLAIN
WHERE THE SHEAR/INSTABILITY PARAMETER SPACE IS BEST. LOW-LEVEL IS
ENHANCED BY A 40KT SOUTHWESTERLY LLJ AND SOUTHEASTERLY SURFACE
WIND...ESPECIALLY IN THE VICINITY OF THE WARM FRONT...AND SHERBE
VALUES ARE PROGGED AROUND 1 THROUGH THE PIEDMONT THIS AFTERNOON.
GOING AGAINST THE SEVERE THREAT IS A GENERAL LACK OF A FOCUS...AS A
NOTABLE MCV OVER NORTHERN GA SHOULD MOVE MORE ALONG THE
MOUNTAINS...AND RAP SOUNDINGS MAINTAIN A SMALL CAPPING INVERSION
THROUGH THE AFTERNOON THAT WOULD LIMIT THE ALREADY WEAK MUCAPE.
HOWEVER...THE SPC MARGINAL RISK STILL LOOKS WARRANTED GIVEN THE
ANOMALOUSLY HIGH PW AND UNUSUAL AIRMASS FOR LATE DECEMBER.
THE FLOODING THREAT...WHILE IT HASN`T MATERIALIZED IN THE
WEST...STILL EXISTS GIVEN THE AFOREMENTIONED MCV MOVING UP FROM GA.
THE HRRR SHOWS A LARGE AREA OF PRECIP...INCREASINGLY CONVECTIVE
LOOKING...OVER THE WESTERN PIEDMONT THIS AFTERNOON. IN ADDITION...A
FEW RIVERS...INCLUDING THE ROCKY RIVER AND HAW RIVER...ARE EITHER
EXPERIENCING MINOR FLOODING OR FORECAST TO FLOOD. SO WE WILL
CONTINUE THE FLASH FLOOD WATCH FOR NOW.
TEMPS WILL SLOWLY RISE THROUGH THE 60S IN THE PIEDMONT AND INTO THE
70S IN THE COASTAL PLAIN...WITH MAX VALUES IN THE 65-75 RANGE THIS
AFTERNOON. -22
SHOWERS WILL CONTINUE TO BE A POSSIBILITY TONIGHT...AND LOW
TEMPERATURES WILL STRUGGLE TO DROP OUT OF THE 70S AT MOST
LOCATIONS...AGAIN HAVING A GOOD CHANCE OF MATCHING THE ALL-TIME
WARMEST DECEMBER MINIMUM TEMPERATURE ON RECORD(RDU-69...FAY-69...GSO-
65).
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 355 AM WEDNESDAY...
ON THE WESTERN PERIPHERY OF ANOMALOUSLY STRONG SUB-TROPICAL RIDGING
CENTERED OVER THE WEST-CENTRAL ATLANTIC...SHORTWAVE RIDGING AND
ASSOCIATED HEIGHT RISES ALOFT WILL BUILD BEHIND THE MAIN SHORTWAVE
TROUGH LIFTING INTO EASTERN CANADA. WITH RIDGING ALOFT AND AN
ASSOCIATED PROBABLE CAPPING INVERSION DEPICTED ON NAM BUFR
SOUNDINGS...THE DAY WILL LIKELY BE A DRY ONE...THOUGH DIURNAL
HEATING OF THE UNSEASONABLY WARM (70S TO AROUND 80 IN IN THE I-95
CORRIDOR) AND HUMID BOUNDARY LAYER MAY ALLOW FOR SOME CU TO BYPASS
THE CAP AND GROW INTO ISOLATED SHOWERS/STORMS. IN ADDITION...AN
UPSTREAM QLCS...IN A REGION OF RESIDUALLY STRONG H85 MOISTURE
TRANSPORT DIRECTED INTO THE TN VALLEY...MAY SUPPORT THE EASTWARD
PROGRESSION OF A WEAKENING LONE OF SHOWERS AND STORMS TO CROSS THE
APPALACHIANS AND DRIFT INTO WESTERN NC...INCLUDING THE WESTERN
PIEDMONT EARLY THU NIGHT. INCREASING CINH WITH NOCTURNAL "COOLING"
INTO THE 60S FAVORS A DRY NIGHT OTHERWISE AND ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 410 AM WEDNESDAY...
THE STRONG SUB-TROPICAL RIDGE...WITH ANOMALOUSLY HIGH HEIGHTS AND
PRECIPITABLE WATER VALUES BETWEEN 200-300 PERCENT OF NORMAL FROM THE
SOUTHEASTERN UNITED STATES TO EAST-CENTRAL CANADA...WILL MAINTAIN A
VERY MILD-WARM REGIME ACROSS THE SOUTHEASTERN STATES THROUGHOUT THE
PERIOD...AND A WET ONE PRIMARILY NORTHWEST OF CENTRAL NC...AT LEAST
UNTIL LATE IN THE PERIOD. THE MAIN FORECAST UNCERTAINTY REMAINS THE
POSITIONING OF A WAVY FRONTAL ZONE FORECAST TO MEANDER ACROSS THE
MIDDLE ATLANTIC STATES...AND CONSEQUENTLY HOW MUCH SUPPRESSION OF
THE WARMTH OCCURS EAST OF THE APPALACHIANS...DICTATED BY A BATTLE
BETWEEN THE SUB-TROPICAL RIDGE AND CONFLUENT SPLIT FLOW
ALOFT/UNDERLYING POLAR HIGHS FORECAST TO DEVELOP ACROSS THE GREAT
LAKES AND NEW ENGLAND BY THIS WEEKEND.
THE TIMING OF POTENTIAL COLD FRONTAL SURGES INTO NC...IF THEY
OCCUR...ARE FAVORED LATE FRI NIGHT-SAT...AND AGAIN SUN NIGHT-
MON...WITH THE FORMER APPEARING INCREASINGLY UNLIKELY TO AFFECT
CENTRAL NC. OTHERWISE UNSEASONABLY MILD-WARM AND HUMID CONDITIONS IN
DEEP SOUTHERLY FLOW AROUND THE SUB-TROPICAL RIDGE WILL PREVAIL. THE
PRIMARY BRANCH OF THE NORTHERN STREAM WILL BE BLOCKED TO THE NW BY
THE SUB-TROPICAL RIDGING...SO FORCING FOR ASCENT AND ASSOCIATED
PRECIPITATION CHANCES WILL REMAIN LOW (GENERALLY AOB 20 PERCENT) AND
INSTEAD DRIVEN BY LOWER AMPLITUDE SOUTHERN STREAM PERTURBATIONS AND
ASSOCIATED SURGES OF LOW LEVEL THETA-E ADVECTION AND BRIEF EROSION
OF A CAPPING INVERSION FRI-SAT...WITH SAID CAPPING MORE LIKELY TO BE
OVERCOME BY DIURNAL HEATING IN AN AIRMASS MORE CHARACTERISTIC OF
APRIL-MAY THAN LATE DECEMBER.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 720 AM WEDNESDAY...
24 HOUR TAF PERIOD: WIDESPREAD ADVERSE AVIATION CONDITIONS WILL
PERSIST THROUGH THE 24 HOUR TAF PERIOD AS AN ANOMALOUSLY MOIST AND
WARM AIRMASS ADVECTS INTO THE AREA.
CEILINGS HAVE IMPROVED TO MVFR AND EVEN VFR ACROSS CENTRAL AND EASTERN
PORTIONS OF THE FORECAST AS WARM SECTOR OVERTAKES THE AREA FROM THE
SOUTH. HOWEVER WE ARE STILL SEEING SOME IFR AND LIFR VISIBILITY
RESTRICTIONS WITH THE HEAVIER SHOWERS. CONDITIONS WILL BE UP AND
DOWN TODAY...BOUNCING FROM VFR TO IFR WITH SCATTERED TO NUMEROUS
SHOWERS AND STORMS EXPECTED THIS AFTERNOON AND EVENING AS WE
DESTABILIZE.
CONDITIONS WILL BE SLOWER TO IMPROVE AT KINT AND KGSO...PERHAPS
IMPROVING TO MVFR BY THE EARLY AFTERNOON AS THE WARM AIR AND
INCREASING INSTABILITY FINALLY HELP TO SCOUR OUT THE LINGERING
WEDGE AIRMASS.
ADDITIONALLY...SOUTHERLY WINDS WILL INCREASE...GUSTING UP TO 20 TO
25 KTS...STRONGEST IN THE EAST.
CEILINGS SHOULD QUICKLY DETERIORATE TO IFR TO LIFR ACROSS THE AREA THIS
EVENING...THOUGH A STEADY 10 TO 15KT SOUTHERLY BREEZE SHOULD
PRECLUDE WIDESPREAD FOG DEVELOPMENT.
OUTLOOK: A MOIST DEEP SOUTHWESTERLY FLOW DOWNSTREAM OF THE LONG WAVE
TROUGH IN PLACE ACROSS THE CENTRAL CONUS WILL SUPPORT A PROLONGED
PERIOD OF ADVERSE AVIATION CONDITIONS THROUGH MUCH OF THE PERIOD.
SUB-VFR CONDITIONS IN LOW CLOUDS/STRATUS WILL ALSO BE LIKELY EACH
MORNING... ALONG WITH THE TREAT OF SOME SHOWERS EACH DAY.
&&
.CLIMATE...
HERE ARE THE AREA RECORD MAXIMUMS AND HIGH MINIMUMS FOR DECEMBER 24TH
AND 25TH. RECORDS HAVE BEEN KEPT IN THE GREENSBORO AREA SINCE
1903... IN THE RALEIGH AREA SINCE 1887... AND IN THE FAYETTEVILLE
AREA SINCE 1910.
DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)
DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...2
NEAR TERM...CBL/22
SHORT TERM...2
LONG TERM...2
AVIATION...CBL
CLIMATE...HARTFIELD/BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1030 AM EST WED DEC 23 2015
.SYNOPSIS...A WEDGE FRONT WILL REMAIN QUASI-STATIONARY OVER THE
PIEDMONT EARLY TODAY...THEN BE OVERTAKEN BY A MARITIME WARM FRONT
THAT WILL SURGE ACROSS THE CAROLINAS AND SOUTHEASTERN VIRGINIA THIS
AFTERNOON. ANOMALOUSLY STRONG SUB-TROPICAL HIGH PRESSURE OVER THE
WEST-CENTRAL ATLANTIC OCEAN WILL THEN DIRECT UNSEASONABLY WARM AND
MOIST SOUTHERLY FLOW THROUGHOUT THE SOUTHEASTERN UNITED STATES
THROUGH CHRISTMAS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM WEDNESDAY...
...FLASH FLOOD WATCH CONTINUES ACROSS THE WESTERN PIEDMONT...
DEEP MOIST SOUTHERLY FLOW...CHARACTERIZED BY NEARLY CLIMATOLOGICAL MAX
PW OF 1.8 INCHES AND 850MB DEWPOINTS OF 14-15C...CONTINUES AROUND THE
ANOMALOUSLY STRONG RIDGE OVER THE WESTERN ATLANTIC. A WEDGE FRONT
IS HOLDING FROM CENTRAL VA THROUGH THE NC WESTERN PIEDMONT AND INTO
UPSTATE SC...WHILE A COASTAL WARM FRONT IS BEGINNING TO SURGE INLAND
AS UPPER 60S DEWPOINTS HAVE REACHED THE I-95 CORRIDOR. IN THE WEDGE
AIRMASS...DENSE FOG WILL CONTINUE...PERIODICALLY DISPERSED BY
SHOWERS SPREADING NORTH THROUGH THE PIEDMONT. NEARLY ALL GUIDANCE
SHOWS THE WEDGE FRONT ERODING AND 60S DEWPOINTS ALL THE WAY THROUGH
FORSYTH CO THIS AFTERNOON. MEANWHILE...THE WARM FRONT AND LEADING
EDGE OF WEAKLY UNSTABLE AIR...WITH MLCAPE POTENTIALLY EXCEEDING 500
J/KG...WILL ALSO CONTINUE INLAND...ALTHOUGH WITH RAIN ALMOST
CONTINUOUS IN THE PIEDMONT IT`S STILL A LITTLE UNCLEAR HOW FAR
INLAND THE WARM SECTOR WILL MIX. DEEP LAYER SHEAR WILL BE 45-
50KT...WHICH WILL SUPPORT A SEVERE THREAT OVER THE COASTAL PLAIN
WHERE THE SHEAR/INSTABILITY PARAMETER SPACE IS BEST. LOW-LEVEL IS
ENHANCED BY A 40KT SOUTHWESTERLY LLJ AND SOUTHEASTERLY SURFACE
WIND...ESPECIALLY IN THE VICINITY OF THE WARM FRONT...AND SHERBE
VALUES ARE PROGGED AROUND 1 THROUGH THE PIEDMONT THIS AFTERNOON.
GOING AGAINST THE SEVERE THREAT IS A GENERAL LACK OF A FOCUS...AS A
NOTABLE MCV OVER NORTHERN GA SHOULD MOVE MORE ALONG THE
MOUNTAINS...AND RAP SOUNDINGS MAINTAIN A SMALL CAPPING INVERSION
THROUGH THE AFTERNOON THAT WOULD LIMIT THE ALREADY WEAK MUCAPE.
HOWEVER...THE SPC MARGINAL RISK STILL LOOKS WARRANTED GIVEN THE
ANOMALOUSLY HIGH PW AND UNUSUAL AIRMASS FOR LATE DECEMBER.
TEMPS WILL SLOWLY RISE THROUGH THE 60S IN THE PIEDMONT AND INTO THE
70S IN THE COASTAL PLAIN...WITH MAX VALUES IN THE 65-75 RANGE THIS
AFTERNOON. -22
SHOWERS WILL CONTINUE TO BE A POSSIBILITY TONIGHT...AND LOW
TEMPERATURES WILL STRUGGLE TO DROP OUT OF THE 70S AT MOST
LOCATIONS...AGAIN HAVING A GOOD CHANCE OF MATCHING THE ALL-TIME
WARMEST DECEMBER MINIMUM TEMPERATURE ON RECORD(RDU-69...FAY-69...GSO-
65).
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 355 AM WEDNESDAY...
ON THE WESTERN PERIPHERY OF ANOMALOUSLY STRONG SUB-TROPICAL RIDGING
CENTERED OVER THE WEST-CENTRAL ATLANTIC...SHORTWAVE RIDGING AND
ASSOCIATED HEIGHT RISES ALOFT WILL BUILD BEHIND THE MAIN SHORTWAVE
TROUGH LIFTING INTO EASTERN CANADA. WITH RIDGING ALOFT AND AN
ASSOCIATED PROBABLE CAPPING INVERSION DEPICTED ON NAM BUFR
SOUNDINGS...THE DAY WILL LIKELY BE A DRY ONE...THOUGH DIURNAL
HEATING OF THE UNSEASONABLY WARM (70S TO AROUND 80 IN IN THE I-95
CORRIDOR) AND HUMID BOUNDARY LAYER MAY ALLOW FOR SOME CU TO BYPASS
THE CAP AND GROW INTO ISOLATED SHOWERS/STORMS. IN ADDITION...AN
UPSTREAM QLCS...IN A REGION OF RESIDUALLY STRONG H85 MOISTURE
TRANSPORT DIRECTED INTO THE TN VALLEY...MAY SUPPORT THE EASTWARD
PROGRESSION OF A WEAKENING LONE OF SHOWERS AND STORMS TO CROSS THE
APPALACHIANS AND DRIFT INTO WESTERN NC...INCLUDING THE WESTERN
PIEDMONT EARLY THU NIGHT. INCREASING CINH WITH NOCTURNAL "COOLING"
INTO THE 60S FAVORS A DRY NIGHT OTHERWISE AND ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 410 AM WEDNESDAY...
THE STRONG SUB-TROPICAL RIDGE...WITH ANOMALOUSLY HIGH HEIGHTS AND
PRECIPITABLE WATER VALUES BETWEEN 200-300 PERCENT OF NORMAL FROM THE
SOUTHEASTERN UNITED STATES TO EAST-CENTRAL CANADA...WILL MAINTAIN A
VERY MILD-WARM REGIME ACROSS THE SOUTHEASTERN STATES THROUGHOUT THE
PERIOD...AND A WET ONE PRIMARILY NORTHWEST OF CENTRAL NC...AT LEAST
UNTIL LATE IN THE PERIOD. THE MAIN FORECAST UNCERTAINTY REMAINS THE
POSITIONING OF A WAVY FRONTAL ZONE FORECAST TO MEANDER ACROSS THE
MIDDLE ATLANTIC STATES...AND CONSEQUENTLY HOW MUCH SUPPRESSION OF
THE WARMTH OCCURS EAST OF THE APPALACHIANS...DICTATED BY A BATTLE
BETWEEN THE SUB-TROPICAL RIDGE AND CONFLUENT SPLIT FLOW
ALOFT/UNDERLYING POLAR HIGHS FORECAST TO DEVELOP ACROSS THE GREAT
LAKES AND NEW ENGLAND BY THIS WEEKEND.
THE TIMING OF POTENTIAL COLD FRONTAL SURGES INTO NC...IF THEY
OCCUR...ARE FAVORED LATE FRI NIGHT-SAT...AND AGAIN SUN NIGHT-
MON...WITH THE FORMER APPEARING INCREASINGLY UNLIKELY TO AFFECT
CENTRAL NC. OTHERWISE UNSEASONABLY MILD-WARM AND HUMID CONDITIONS IN
DEEP SOUTHERLY FLOW AROUND THE SUB-TROPICAL RIDGE WILL PREVAIL. THE
PRIMARY BRANCH OF THE NORTHERN STREAM WILL BE BLOCKED TO THE NW BY
THE SUB-TROPICAL RIDGING...SO FORCING FOR ASCENT AND ASSOCIATED
PRECIPITATION CHANCES WILL REMAIN LOW (GENERALLY AOB 20 PERCENT) AND
INSTEAD DRIVEN BY LOWER AMPLITUDE SOUTHERN STREAM PERTURBATIONS AND
ASSOCIATED SURGES OF LOW LEVEL THETA-E ADVECTION AND BRIEF EROSION
OF A CAPPING INVERSION FRI-SAT...WITH SAID CAPPING MORE LIKELY TO BE
OVERCOME BY DIURNAL HEATING IN AN AIRMASS MORE CHARACTERISTIC OF
APRIL-MAY THAN LATE DECEMBER.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 720 AM WEDNESDAY...
24 HOUR TAF PERIOD: WIDESPREAD ADVERSE AVIATION CONDITIONS WILL
PERSIST THROUGH THE 24 HOUR TAF PERIOD AS AN ANOMALOUSLY MOIST AND
WARM AIRMASS ADVECTS INTO THE AREA.
CEILINGS HAVE IMPROVED TO MVFR AND EVEN VFR ACROSS CENTRAL AND EASTERN
PORTIONS OF THE FORECAST AS WARM SECTOR OVERTAKES THE AREA FROM THE
SOUTH. HOWEVER WE ARE STILL SEEING SOME IFR AND LIFR VISIBILITY
RESTRICTIONS WITH THE HEAVIER SHOWERS. CONDITIONS WILL BE UP AND
DOWN TODAY...BOUNCING FROM VFR TO IFR WITH SCATTERED TO NUMEROUS
SHOWERS AND STORMS EXPECTED THIS AFTERNOON AND EVENING AS WE
DESTABILIZE.
CONDITIONS WILL BE SLOWER TO IMPROVE AT KINT AND KGSO...PERHAPS
IMPROVING TO MVFR BY THE EARLY AFTERNOON AS THE WARM AIR AND
INCREASING INSTABILITY FINALLY HELP TO SCOUR OUT THE LINGERING
WEDGE AIRMASS.
ADDITIONALLY...SOUTHERLY WINDS WILL INCREASE...GUSTING UP TO 20 TO
25 KTS...STRONGEST IN THE EAST.
CEILINGS SHOULD QUICKLY DETERIORATE TO IFR TO LIFR ACROSS THE AREA THIS
EVENING...THOUGH A STEADY 10 TO 15KT SOUTHERLY BREEZE SHOULD
PRECLUDE WIDESPREAD FOG DEVELOPMENT.
OUTLOOK: A MOIST DEEP SOUTHWESTERLY FLOW DOWNSTREAM OF THE LONG WAVE
TROUGH IN PLACE ACROSS THE CENTRAL CONUS WILL SUPPORT A PROLONGED
PERIOD OF ADVERSE AVIATION CONDITIONS THROUGH MUCH OF THE PERIOD.
SUB-VFR CONDITIONS IN LOW CLOUDS/STRATUS WILL ALSO BE LIKELY EACH
MORNING... ALONG WITH THE TREAT OF SOME SHOWERS EACH DAY.
&&
.CLIMATE...
HERE ARE THE AREA RECORD MAXIMUMS AND HIGH MINIMUMS FOR DECEMBER 24TH
AND 25TH. RECORDS HAVE BEEN KEPT IN THE GREENSBORO AREA SINCE
1903... IN THE RALEIGH AREA SINCE 1887... AND IN THE FAYETTEVILLE
AREA SINCE 1910.
DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)
DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...2
NEAR TERM...CBL/22
SHORT TERM...2
LONG TERM...2
AVIATION...CBL
CLIMATE...HARTFIELD/BLAES
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1029 AM EST WED DEC 23 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH THE WEEKEND. A WEAK
COLD FRONT WILL APPROACH FROM THE NORTH THURSDAY NIGHT THEN STALL
NEAR THE VIRGINIA BORDER FRIDAY. THE FRONT WILL LIFT BACK NORTH
OVER THE WEEKEND.
&&
.NEAR TERM /REST OF TODAY/...
AS OF 1020 AM WEDNESDAY...LATE MORNING UPDATE FOR ONLY MINOR
TWEAKS IN THE NEAR TERM. CONVECTION HAS SHOWN POTENTIAL TO BECOME
SEVERE FOR WESTERN ZONES (DUPLIN/ONSLOW/GREENE/LENOIR COUNTIES)
WHERE SPC MESOANALYSES INDICATE BETTER INSTABILITY. IR SATELLITE
IMAGERY INDICATED WARMING CLOUD TOPS AS THE EARLIER CONVECTION
SHIFTS NORTH ACROSS THE HWY 64 CORRIDOR. A PERIOD OF HEAVY RAIN
AND POSSIBLY GUSTY WINDS WILL STILL BE POSSIBLE INTO EARLY
AFTERNOON WITH SHOWER COVERAGE INCREASING FROM THE SOUTH AND WEST.
THE SYNOPTIC PATTERN PRESENTS AN UPPER TROUGH MOVING INTO THE
PLAINS WITH RIDGING OVER THE ATLANTIC, BRINGING DEEP SW FLOW
ACROSS THE EASTERN CONUS THAT IS TAPPING INTO TROPICAL PACIFIC
MOISTURE BRINGING PWATS AROUND 1.75 INCHES WHICH IS AT OR ABOVE
CLIMATOLOGICAL MAXIMUM FOR LATE DECEMBER. SFC HIGH PRES REMAINS
CENTERED OFFSHORE WITH A COASTAL TROUGH JUST SOUTH OF THE REGION
PROGGED TO LIFT ACROSS THE REGION TODAY. THIS PATTERN WILL
CONTINUE TO BRING PERIODS OF SHOWERS ACROSS THE REGION TODAY WHICH
ARE BEING ENHANCED BY WEAK EMBEDDED SHORTWAVES MOVING THROUGH THE
FLOW ALOFT. COULD SEE A FEW STRONGER STORMS DEVELOP THROUGH THE
AFTERNOON HOURS AS THE AIRMASS DESTABILIZES IN THE PRESENCE OF
STRONG LOW LEVEL SHEAR. HRRR IS FORECASTING MLCAPE AROUND
1000-1500J/KG AND LI`S AROUND -4C WITH 40-50 KT 0-6KM SHEAR AND
0-1KM HELICITY AROUND 200-300 M2/S2 THIS AFTERNOON WITH HIGHEST
VALUES WEST OF HIGHWAY 17. SPC HAS MOST OF THE REGION OUTLOOKED
FOR A MARGINAL RISK OF SEVERE THUNDERSTORMS WITH DAMAGING WIND
GUSTS AND AN ISOLATED TORNADO THE PRIMARY THREAT. PERIODS OF HEAVY
RAINFALL WITH LOCALIZED FLOODING OF POOR DRAINAGE AND LOW LYING
AREA WILL ALSO BE POSSIBLE. EXPECT GUSTY SLY WINDS TO DEVELOP LATE
MORNING THROUGH THE AFTERNOON IN THE WAKE OF THE TROUGH LIFTING
ACROSS THE REGION WHICH COULD BRING GUSTS AROUND 20-30 MPH. TEMPS
WILL BE ALMOST 20 DEGREES ABOVE NORMAL WITH HIGHS EXPECTED IN THE
MID 70S.
&&
.SHORT TERM /TONIGHT/...
AS OF 3 AM WEDNESDAY....LITTLE CHANGE IN THE PATTERN TONIGHT WITH
MOIST SW FLOW CONTINUING. A FEW STRONGER STORMS WILL BE POSSIBLE
EARLY IN THE EVENING BUT GENERALLY EXPECT A DECREASE IN COVERAGE
THROUGH THE OVERNIGHT AS SHORTWAVE ENERGY LIFTS NORTH OF THE
REGION AND THE UPPER RIDGE OVER THE WESTERN ATLANTIC BEGINS TO
BUILDS WEST SOME. WILL CONTINUE A DECREASING TREND IN POPS THROUGH
THE OVERNIGHT. MODERATE SLY WINDS WILL BRING VERY MILD OVERNIGHT
TEMPS IN THE UPPER 60S TO 70...WHICH IS ABOUT 30-35 DEGREES ABOVE
NORMAL AND WILL LIKELY BREAK RECORD HIGH MINIMUM TEMPERATURES FOR
THE DAY...SEE CLIMATE SECTION BELOW.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 220 AM WED...BIG STORY WILL BE RECORD BREAKING WARM TEMPS
THROUGH MUCH OF THE PERIOD AS STRONG UPPER RIDGE OVER THE ATLANTIC
BUILDS WEST TOWARD THE COAST INTO THE WEEKEND.
THURSDAY THROUGH CHRISTMAS DAY...COVERAGE OF PRECIPITATION WILL
DROP A BIT FOR THURSDAY AND FRIDAY AS UPR RDG GRAD BUILDS W. FCST
SOUNDINGS FOR THU SHOW SBCAPE VALUES POSSIBLY GREATER THAN 1500
J/KG AND LI`S IN THE -3 TO -5 RANGE DURING THE AFTERNOON ALONG
WITH DECENT SHEAR...HOWEVER LACK OF FORCING MAY LIMIT TSRA
POTENTIAL. A FEW STRONG TO POSS SEVERE STORMS CAN NOT BE RULED
OUT GIVEN THE VERY HIGH INSTAB FOR LATE DEC. LOW LVL
THICKNESS/850 TEMPS PEAK THU AFTN WITH SOME HIGHS TEMPS IN THE
LOWER 80S POSS WHICH WILL LIKELY BREAK NUMEROUS RECORDS AND POSS
SET ALL TIME DEC RECORDS. ON FRI UPR RDG BUILDS CLOSER WHICH WILL
ACT TO SUPPRESS CONVECTION AND WITH MORE SUN TEMPS WILL AGAIN BE
VERY WARM REACHING AROUND 80 AGAIN WARMER SPOTS.
SATURDAY THROUGH SUNDAY...STRONG UPPER LEVEL RIDGE HOLDS ACROSS
THE SOUTHEASTERN UNITED STATES THROUGH THE WEEKEND AS LOW
PRESSURE MOVES FROM THE MISSISSIPPI VALLEY INTO THE GREAT LAKES
REGION. THIS WILL KEEP UNSEASONABLY WARM TEMPERATURES IN PLACE
WITH DAYTIME HIGHS WELL INTO THE 70S SATURDAY AND SUNDAY WITH LOWS
IN THE 60S. THERE WILL BE ONLY A SMALL CHANCE OF SHOWERS EACH DAY
GIVEN THE CONTINUED RATHER MOIST AIRMASS WITH FORECAST
PRECIPITABLE WATER VALUES AOA 1.50 INCHES.
MONDAY THROUGH TUESDAY...UPR RDG WILL BEGIN TO SHIFT BACK E WITH
MDLS SHOWING BACKDOOR FRONT DROPPING INTO THE REGION MON THEN
LIFTING BACK N TUE AHEAD OF STRONGER APPROACHING FRONT. CONT PREV
FCST OF CHC POPS EARLY NEXT WEEK WITH STILL VERY MILD TEMPS IN THE
60S TO LOWER 70S...POSS SOME MID 70S TUE.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1020 AM WEDNESDAY...NUMEROUS TO WIDESPREAD SHOWERS ACROSS
THE TERMINALS WHICH MAY BRIEFLY REDUCE VSBYS/CEILINGS INTO THE
AFTERNOON. VFR EXPECTED TO BECOME DOMINANT BY 16/17Z, OUTSIDE OF
HEAVIER SHOWERS. MOIST SW FLOW WILL CONTINUE TO BRING PERIODS OF
SHOWERS ACROSS THE REGION THROUGH THE TAF PERIOD. SOME STORMS
COULD BE STRONG TO MARGINALLY SEVERE TODAY IF INSTABILITY CAN BE
REALIZED WITH STRONG SHEAR IN PLACE AND SHORTWAVE ENERGY MOVING
ACROSS THE REGION. ISOLATED STORMS COULD BRING DAMAGING WIND GUSTS
OR AND WEAK TORNADO. STRONG S WINDS ALSO EXPECTED TO DEVELOP LATE
THIS MORNING THROUGH THE AFTERNOON WITH GUSTS AROUND 20-25 KT
LIKELY. SUB-VFR CONDITIONS POSSIBLE IN STRATUS TONIGHT, ESPECIALLY
INLAND, AS THE BOUNDARY LAYER REMAINS NEAR SATURATION BUT MODERATE
SLY FLOW AROUND 10 KT CONTINUES OVERNIGHT AND THINK VSBYS BELOW
2SM AS SUGGESTED IN SOME OF THE MOS GUIDANCE IS OVERLY
PESSIMISTIC.
LONG TERM /THU THROUGH SATURDAY/...
AS OF 220 AM WED...COVERAGE OF SHRA/TSRA WILL BE LESS THURSDAY
THROUGH SAT BUT WITH LOW LEVELS REMAINING VERY MOIST BOUTS OF SUB
VFR STRATUS AND FOG WILL BE LIKELY LATE NIGHT/EARLY MORN. MAINLY
VFR LATE MORN THRU EVENING HOURS WITH ONLY SMALL CHC OF SHRA/TSRA
CROSSING. ISOLATED STRONG THUNDERSTORMS WILL BE POSS THU.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 1025 AM WEDNESDAY...LATEST SURFACE AND BUOY DATA INDICATE SE
TO SSW WINDS ACROSS THE EASTERN NC WATERS 5-15 KT WITH GUSTS NEAR
20 KT FOR THE OUTER BUOYS 41025/41064. THE SURFACE RIDGE REMAINS
CENTERED OFF THE SOUTHEAST COAST THROUGH THE SHORT TERM. A COASTAL
TROUGH JUST SOUTH OF THE WATERS IS PROGGED TO LIFT ACROSS THE
REGION THIS MORNING. SE WINDS AROUND 5-15 KT WILL BECOME SLY AND
INCREASE TO 15-25 KT WITH HIGHER GUSTS AFTER THE TROUGH LIFTS
ACROSS THE REGION AND CONTINUE THROUGH MUCH OF THE OVERNIGHT. SEAS
CURRENTLY AROUND 3-6 FT WILL BUILD IN RESPONSE TO THE STRONGER SLY
FLOW THROUGH THE DAY...PEAKING AROUND 6-10 FT TONIGHT. STRONGEST
WINDS/SEAS WILL OCCUR OVER THE COASTAL WATERS AND WILL CONTINUE
THE SCA. THE SOUNDS AND RIVERS EXPECTED TO REMAIN JUST BELOW
ADVISORY CRITERIA BUT MAY BE CLOSE ACROSS THE PAMLICO SOUND,
ESPECIALLY IN GUSTS.
LONG TERM /THU THROUGH SATURDAY/...
AS OF 220 AM WED...SSW WINDS 15 TO 25 KTS WILL CONT THU BETWEEN
HIGH PRESSURE NEAR BERMUDA AND LOW PRESSURE LIFTING NORTHEAST OF
THE GREAT LAKES. SW WINDS WILL GRAD SUBSIDE THU NIGHT AND FRI AS
WEAK FRONT STALLS TO THE NORTH. THE FRONT WILL LIFT BACK N SAT
WITH CONT LIGHT S TO SW FLOW. SEAS WILL REMAIN ELEVATED THU AND
THU NIGH WITH SCA CONT COASTAL WATERS. SEAS WILL PEAK AT AROUND 8
FT OUTER SRN/CNTRL WATERS THU. SEAS WILL SUBSIDE THU NIGHT AND
FRI WITH SCA ENDING NRN WATERS LATE THU NIGHT AND REST OF WATERS
BY MID DAY FRI. SEAS WILL CONT IN THE 3 TO 5 FT RANGE THRU SAT.
&&
.CLIMATE...
EXTREMELY WARM AND HUMID WEATHER FOR DECEMBER WILL DOMINATE THE
REMAINDER OF CHRISTMAS WEEK. THE FOLLOWING ARE RECORD HIGH MAX
TEMPS, AS WELL AS RECORD HIGH MIN TEMPS, FOR 12/23 THROUGH 12/25,
WHEN THE WARMEST TEMPS ARE EXPECTED. ALSO INCLUDED ARE THE ALL-
TIME HIGHS FOR DECEMBER.
RECORD HIGH MAX TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 79/2013 (KEWN ASOS)
CAPE HATTERAS 75/1990 (KHSE ASOS)
GREENVILLE 79/1967 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1990 (COOP NOT KMRH ASOS)
KINSTON 82/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 82/1981 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 63/1990 (KEWN ASOS)
CAPE HATTERAS 66/1990 (KHSE ASOS)
GREENVILLE 61/1990 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 64/2013 (COOP - NOT KMRH ASOS)
KINSTON 65/2013 (COOP- NOT KISO AWOS)
JACKSONVILLE 63/1956 (KNCA AWOS)
RECORD HIGH MAX TEMPS F0R 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 76/1964 (KEWN ASOS)
CAPE HATTERAS 72/1990 (KHSE ASOS)
GREENVILLE 73/1988 (COOP NOT KPGV AWOS)
MOREHEAD CITY 72/1990 (COOP NOT KMRH ASOS)
KINSTON 78/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 74/1990 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 55/2014 (KEWN ASOS)
CAPE HATTERAS 62/1986 (KHSE ASOS)
GREENVILLE 56/1956 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/1956 (COOP - NOT KMRH ASOS)
KINSTON 63/1990 (COOP- NOT KISO AWOS)
JACKSONVILLE 54/2014 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 78/1955 (KEWN ASOS)
CAPE HATTERAS 73/1964 (KHSE ASOS)
GREENVILLE 77/1964 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1974 (COOP NOT KMRH ASOS)
KINSTON 78/1932 (COOP NOT KISO AWOS)
JACKSONVILLE 76/1974 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 63/1964 (KEWN ASOS)
CAPE HATTERAS 61/1964 (KHSE ASOS)
GREENVILLE 59/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/2008 (COOP - NOT KMRH ASOS)
KINSTON 61/1932 (COOP- NOT KISO AWOS)
JACKSONVILLE 61/1987 (KNCA AWOS)
**ALL-TIME RECORD HIGH TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 83/1971 (KEWN ASOS)
CAPE HATTERAS 78/1991 (KHSE ASOS)
GREENVILLE 82/1998 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 79/1998 (COOP - NOT KMRH ASOS)
KINSTON 87/1918 (COOP - NOT KISO AWOS)
JACKSONVILLE 82/1998 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 3 AM EST FRIDAY FOR AMZ150.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK/DAG
SHORT TERM...SK
LONG TERM...RF/DAG
AVIATION...RF/SK
MARINE...RF/SK/DAG
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
732 AM EST WED DEC 23 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH THE WEEKEND. A WEAK
COLD FRONT WILL APPROACH FROM THE NORTH THURSDAY NIGHT THEN STALL
NEAR THE VIRGINIA BORDER FRIDAY. THE FRONT WILL LIFT BACK NORTH
OVER THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 7 AM WEDNESDAY...UPDATE INCREASES POPS FOLLOWING RADAR
TRENDS. AREA OF STRONGER SHOWERS AND THUNDERSTORMS ACROSS SE NC
WITH IR SATELLITE SHOWING COOLING CLOUD TOPS WILL BE WATCHED
CLOSELY AS IT IS PROGGED TO MOVE ACROSS THE COASTAL PLAIN THROUGH
MORNING...WHICH WILL BRING A PERIOD OF HEAVY RAIN AND POSSIBLY
GUSTY WINDS. ALSO UPDATED T/TD TRENDS WHICH HAVE BEEN INCREASING
A FEW DEGREES OVER THE PAST SEVERAL HOURS MOST LOCATIONS.
PREVIOUS DISCUSSION...AN UPPER TROUGH MOVING INTO THE PLAINS WITH
RIDGING OVER THE ATLANTIC IS BRINGING DEEP SW FLOW ACROSS THE
EASTERN CONUS THAT IS TAPPING INTO TROPICAL PACIFIC MOISTURE
BRINGING PWATS AROUND 1.75 INCHES WHICH IS AT OR ABOVE
CLIMATOLOGICAL MAXIMUM FOR LATE DECEMBER. SFC HIGH PRES REMAINS
CENTERED OFFSHORE WITH A COASTAL TROUGH JUST SOUTH OF THE REGION
PROGGED TO LIFT ACROSS THE REGION TODAY. THIS PATTERN WILL
CONTINUE TO BRING PERIODS OF SHOWERS ACROSS THE REGION TODAY WHICH
ARE BEING ENHANCED BY WEAK EMBEDDED SHORTWAVES MOVING THROUGH THE
FLOW ALOFT. COULD SEE A FEW STRONGER STORMS DEVELOP THROUGH THE
AFTERNOON HOURS AS THE AIRMASS DESTABILIZES IN THE PRESENCE OF
STRONG LOW LEVEL SHEAR. HRRR IS FORECASTING MLCAPE AROUND
1000-1500J/KG AND LI`S AROUND -4C WITH 40-50 KT 0-6KM SHEAR AND
0-1KM HELICITY AROUND 200-300 M2/S2 THIS AFTERNOON WITH HIGHEST
VALUES WEST OF HIGHWAY 17. SPC HAS MOST OF THE REGION OUTLOOKED
FOR A MARGINAL RISK OF SEVERE THUNDERSTORMS WITH DAMAGING WIND
GUSTS AND AN ISOLATED TORNADO THE PRIMARY THREAT. PERIODS OF HEAVY
RAINFALL WITH LOCALIZED FLOODING OF POOR DRAINAGE AND LOW LYING
AREA WILL ALSO BE POSSIBLE. EXPECT GUSTY SLY WINDS TO DEVELOP LATE
MORNING THROUGH THE AFTERNOON IN THE WAKE OF THE TROUGH LIFTING
ACROSS THE REGION WHICH COULD BRING GUSTS AROUND 20-30 MPH. TEMPS
WILL BE ALMOST 20 DEGREES ABOVE NORMAL WITH HIGHS EXPECTED IN THE
MID 70S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM THURSDAY/...
AS OF 3 AM WEDNESDAY....LITTLE CHANGE IN THE PATTERN TONIGHT WITH
MOIST SW FLOW CONTINUING. A FEW STRONGER STORMS WILL BE POSSIBLE
EARLY IN THE EVENING BUT GENERALLY EXPECT A DECREASE IN COVERAGE
THROUGH THE OVERNIGHT AS SHORTWAVE ENERGY LIFTS NORTH OF THE
REGION AND THE UPPER RIDGE OVER THE WESTERN ATLANTIC BEGINS TO
BUILDS WEST SOME. WILL CONTINUE A DECREASING TREND IN POPS THROUGH
THE OVERNIGHT. MODERATE SLY WINDS WILL BRING VERY MILD OVERNIGHT
TEMPS IN THE UPPER 60S TO 70...WHICH IS ABOUT 30-35 DEGREES ABOVE
NORMAL AND WILL LIKELY BREAK RECORD HIGH MINIMUM TEMPERATURES FOR
THE DAY...SEE CLIMATE SECTION BELOW.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
AS OF 220 AM WED...BIG STORY WILL BE RECORD BREAKING WARM TEMPS
THROUGH MUCH OF THE PERIOD AS STRONG UPPER RIDGE OVER THE ATLANTIC
BUILDS WEST TOWARD THE COAST INTO THE WEEKEND.
THURSDAY THROUGH CHRISTMAS DAY...COVERAGE OF PRECIPITATION WILL
DROP A BIT FOR THURSDAY AND FRIDAY AS UPR RDG GRAD BUILDS W. FCST
SOUNDINGS FOR THU SHOW SBCAPE VALUES POSSIBLY GREATER THAN 1500
J/KG AND LI`S IN THE -3 TO -5 RANGE DURING THE AFTERNOON ALONG
WITH DECENT SHEAR...HOWEVER LACK OF FORCING MAY LIMIT TSRA
POTENTIAL. A FEW STRONG TO POSS SEVERE STORMS CAN NOT BE RULED
OUT GIVEN THE VERY HIGH INSTAB FOR LATE DEC. LOW LVL
THICKNESS/850 TEMPS PEAK THU AFTN WITH SOME HIGHS TEMPS IN THE
LOWER 80S POSS WHICH WILL LIKELY BREAK NUMEROUS RECORDS AND POSS
SET ALL TIME DEC RECORDS. ON FRI UPR RDG BUILDS CLOSER WHICH WILL
ACT TO SUPPRESS CONVECTION AND WITH MORE SUN TEMPS WILL AGAIN BE
VERY WARM REACHING AROUND 80 AGAIN WARMER SPOTS.
SATURDAY THROUGH SUNDAY...STRONG UPPER LEVEL RIDGE HOLDS ACROSS
THE SOUTHEASTERN UNITED STATES THROUGH THE WEEKEND AS LOW
PRESSURE MOVES FROM THE MISSISSIPPI VALLEY INTO THE GREAT LAKES
REGION. THIS WILL KEEP UNSEASONABLY WARM TEMPERATURES IN PLACE
WITH DAYTIME HIGHS WELL INTO THE 70S SATURDAY AND SUNDAY WITH LOWS
IN THE 60S. THERE WILL BE ONLY A SMALL CHANCE OF SHOWERS EACH DAY
GIVEN THE CONTINUED RATHER MOIST AIRMASS WITH FORECAST
PRECIPITABLE WATER VALUES AOA 1.50 INCHES.
MONDAY THROUGH TUESDAY...UPR RDG WILL BEGIN TO SHIFT BACK E WITH
MDLS SHOWING BACKDOOR FRONT DROPPING INTO THE REGION MON THEN
LIFTING BACK N TUE AHEAD OF STRONGER APPROACHING FRONT. CONT PREV
FCST OF CHC POPS EARLY NEXT WEEK WITH STILL VERY MILD TEMPS IN THE
60S TO LOWER 70S...POSS SOME MID 70S TUE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 7 AM WEDNESDAY...AREAS OF FOG/ST CONTINUES ACROSS THE
COASTAL PLAIN THIS MORNING BRINGING IFR/LIFR CONDITIONS ALONG WITH
NUMEROUS TO WIDESPREADS SHOWERS ACROSS RTES. CONDITIONS EXPECTED
TO ONLY GRADUALLY IMPROVE THIS MORNING WITH VFR EXPECTED TO BECOME
DOMINANT AROUND 15Z...OUTSIDE OF HEAVIER SHOWERS. MOIST SW FLOW
WILL CONTINUE TO BRING PERIODS OF SHOWERS ACROSS THE REGION
THROUGH THE TAF PERIOD. SOME STORMS COULD BE STRONG TO MARGINALLY
SEVERE TODAY IF INSTABILITY CAN BE REALIZED WITH STRONG SHEAR IN
PLACE AND SHORTWAVE ENERGY MOVING ACROSS THE REGION. ISOLATED
STORMS COULD BRING DAMAGING WIND GUSTS OR AND WEAK TORNADO. STRONG
S WINDS ALSO EXPECTED TO DEVELOP LATE THIS MORNING THROUGH THE
AFTERNOON WITH GUSTS AROUND 20-25 KT LIKELY. SUB-VFR CONDITIONS
POSSIBLE IN STRATUS TONIGHT...ESPECIALLY INLAND...AS THE BOUNDARY
LAYER REMAINS NEAR SATURATION BUT MODERATE SLY FLOW AROUND 10 KT
CONTINUES OVERNIGHT AND THINK VSBYS BELOW 2SM AS SUGGESTED IN
SOME OF THE MOS GUIDANCE IS OVERLY PESSIMISTIC.
LONG TERM /THU THROUGH SATURDAY/...
AS OF 220 AM WED...COVERAGE OF SHRA/TSRA WILL BE LESS THURSDAY
THROUGH SAT BUT WITH LOW LEVELS REMAINING VERY MOIST BOUTS OF SUB
VFR STRATUS AND FOG WILL BE LIKELY LATE NIGHT/EARLY MORN. MAINLY
VFR LATE MORN THRU EVENING HOURS WITH ONLY SMALL CHC OF SHRA/TSRA
CROSSING. ISOLATED STRONG THUNDERSTORMS WILL BE POSS THU.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/
AS OF 3 AM WEDNESDAY...SFC HIGH PRES REMAINS CENTERED OFF THE
SOUTHEAST COAST THROUGH THE SHORT TERM. A COASTAL TROUGH JUST
SOUTH OF THE WATERS IS PROGGED TO LIFT ACROSS THE REGION THIS
MORNING. SE WINDS AROUND 5-15 KT WILL BECOME SLY AND INCREASE TO
15-25 KT WITH HIGHER GUSTS AFTER THE TROUGH LIFTS ACROSS THE
REGION AND CONTINUE THROUGH MUCH OF THE OVERNIGHT. SEAS CURRENTLY
AROUND 3-6 FT WILL BUILD IN RESPONSE TO THE STRONGER SLY FLOW
THROUGH THE DAY...PEAKING AROUND 6-10 FT TONIGHT. STRONGEST
WINDS/SEAS WILL OCCUR OVER THE COASTAL WATERS AND WILL CONTINUE
THE SCA. THE SOUNDS AND RIVERS EXPECTED TO REMAIN JUST BELOW
ADVISORY CRITERIA...BUT MAY BE CLOSE ACROSS THE PAMLICO
SOUND...ESPECIALLY IN GUSTS.
LONG TERM /THU THROUGH SATURDAY/...
AS OF 220 AM WED...SSW WINDS 15 TO 25 KTS WILL CONT THU BETWEEN
HIGH PRESSURE NEAR BERMUDA AND LOW PRESSURE LIFTING NORTHEAST OF
THE GREAT LAKES. SW WINDS WILL GRAD SUBSIDE THU NIGHT AND FRI AS
WEAK FRONT STALLS TO THE NORTH. THE FRONT WILL LIFT BACK N SAT
WITH CONT LIGHT S TO SW FLOW. SEAS WILL REMAIN ELEVATED THU AND
THU NIGH WITH SCA CONT CSTL WTRS. SEAS WILL PEAK AT AROUND 8 FT
OUTER SRN/CNTRL WTRS THU. SEAS WILL SUBSIDE THU NIGHT AND FRI WITH
SCA ENDING NRN WTRS LATE THU NIGHT AND REST OF WTRS BY MID DAY
FRI. SEAS WILL CONT IN THE 3 TO 5 FT RANGE THRU SAT.
&&
.CLIMATE...
EXTREMELY WARM AND HUMID WEATHER FOR DECEMBER WILL DOMINATE THE
REMAINDER OF CHRISTMAS WEEK. THE FOLLOWING ARE RECORD HIGH MAX
TEMPS, AS WELL AS RECORD HIGH MIN TEMPS, FOR 12/23 THROUGH 12/25,
WHEN THE WARMEST TEMPS ARE EXPECTED. ALSO INCLUDED ARE THE ALL-
TIME HIGHS FOR DECEMBER.
RECORD HIGH MAX TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 79/2013 (KEWN ASOS)
CAPE HATTERAS 75/1990 (KHSE ASOS)
GREENVILLE 79/1967 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1990 (COOP NOT KMRH ASOS)
KINSTON 82/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 82/1981 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 63/1990 (KEWN ASOS)
CAPE HATTERAS 66/1990 (KHSE ASOS)
GREENVILLE 61/1990 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 64/2013 (COOP - NOT KMRH ASOS)
KINSTON 65/2013 (COOP- NOT KISO AWOS)
JACKSONVILLE 63/1956 (KNCA AWOS)
RECORD HIGH MAX TEMPS F0R 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 76/1964 (KEWN ASOS)
CAPE HATTERAS 72/1990 (KHSE ASOS)
GREENVILLE 73/1988 (COOP NOT KPGV AWOS)
MOREHEAD CITY 72/1990 (COOP NOT KMRH ASOS)
KINSTON 78/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 74/1990 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 55/2014 (KEWN ASOS)
CAPE HATTERAS 62/1986 (KHSE ASOS)
GREENVILLE 56/1956 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/1956 (COOP - NOT KMRH ASOS)
KINSTON 63/1990 (COOP- NOT KISO AWOS)
JACKSONVILLE 54/2014 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 78/1955 (KEWN ASOS)
CAPE HATTERAS 73/1964 (KHSE ASOS)
GREENVILLE 77/1964 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1974 (COOP NOT KMRH ASOS)
KINSTON 78/1932 (COOP NOT KISO AWOS)
JACKSONVILLE 76/1974 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 63/1964 (KEWN ASOS)
CAPE HATTERAS 61/1964 (KHSE ASOS)
GREENVILLE 59/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/2008 (COOP - NOT KMRH ASOS)
KINSTON 61/1932 (COOP- NOT KISO AWOS)
JACKSONVILLE 61/1987 (KNCA AWOS)
**ALL-TIME RECORD HIGH TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 83/1971 (KEWN ASOS)
CAPE HATTERAS 78/1991 (KHSE ASOS)
GREENVILLE 82/1998 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 79/1998 (COOP - NOT KMRH ASOS)
KINSTON 87/1918 (COOP - NOT KISO AWOS)
JACKSONVILLE 82/1998 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 3 AM EST FRIDAY FOR AMZ150.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK
SHORT TERM...SK
LONG TERM...RF/DAG
AVIATION...RF/SK
MARINE...RF/SK
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
720 AM EST WED DEC 23 2015
.SYNOPSIS...A WEDGE FRONT WILL REMAIN QUASI-STATIONARY OVER THE
PIEDMONT EARLY TODAY...THEN BE OVERTAKEN BY A MARITIME WARM FRONT
THAT WILL SURGE ACROSS THE CAROLINAS AND SOUTHEASTERN VIRGINIA THIS
AFTERNOON. ANOMALOUSLY STRONG SUB-TROPICAL HIGH PRESSURE OVER THE
WEST-CENTRAL ATLANTIC OCEAN WILL THEN DIRECT UNSEASONABLY WARM AND
MOIST SOUTHERLY FLOW THROUGHOUT THE SOUTHEASTERN UNITED STATES
THROUGH CHRISTMAS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 355 AM WEDNESDAY...
...FLASH FLOOD WATCH CONTINUES ACROSS THE WESTERN PIEDMONT...
A SHORTWAVE TROUGH EMBEDDED WITHIN LARGER-SCALE TROUGH SITUATED
ACROSS MUCH OF THE CONUS WILL ADVANCE NEWD FROM THE SRN PLAINS
TOWARDS THE UPPER GREAT LAKES. ACCOMPANYING DEEPENING SFC LOW WILL
FOLLOW SUITE...TRACKING NEWD FROM THE MID-MO VALLEY TO THE UPPER MS
VALLEY BY LATE AFTERNOON. WHILE THESE FEATURES ARE A LITTLE WAYS
FROM HOME...DEEP SOUTHERLY FLOW ON THE EAST SIDE OF THE TROUGH WILL
ADVECT MODIFIED GULF AIR NORTHWARD INTO THE AREA...BRINGING
ANOMALOUS MOIST AND WARM AIR INTO THE AREA. PWATS ARE FORECAST TO
INCREASE TO 1.6-1.9"(4-5 STANDARD DEVIATIONS ABOVE NORMAL)...WHICH
WILL RIVAL MAX DECEMBER VALUES AT KGSO(1.65"-DATING BACK TO
1948)...WHILE TONIGHTS LOW TEMPERATURES WILL STRUGGLE TO DROP OUT OF
THE 70S AT MOST LOCATIONS...AGAIN HAVING A GOOD CHANCE OF MATCHING
THE ALL-TIME WARMEST DECEMBER MINIMUM TEMPERATURE ON RECORD(RDU-
69...FAY-69...GSO-65).
TWO MAIN CONCERNS ARE: 1)PERIODS OF MODERATE TO HEAVY RAINFALL THAT
MAY RESULT IN BOTH FLASHING FLOODING AS WELL AS MINOR FLOODING
ON AREAS RIVERS AND CREEKS AND 2)ISOLATED THREAT OF SEVERE STORMS
LATER TODAY.
FLOOD THREAT: LATEST RADAR TRENDS SHOW AN UPTICK IN CONVECTION
BREAKING OUT ACROSS THE AREA...FUELED BY A STRENGTHENING 50-60KTS
S-SWLY LOW-LEVEL FLOW EAST OF THE AMPLIFYING SYSTEM TO OUR WEST.
MOST RECENT HRRR SIMULATIONS ARE HANDLING THE CONVECTION
BEST...DEPICTING THE HEAVIEST RAINFALL THIS MORNING ALONG AND EAST
OF HIGHWAY 1. THE AFOREMENTIONED HIGH MOISTURE ANOMALIES WILL
SUPPORT THE POTENTIAL FOR 1.5-2.0"/HOUR RAINFALL RATES OVER THESE
AREAS THIS MORNING THAT WOULD LIKELY CAUSE SOME LOCALIZED FLOODING
GIVEN SATURATED SOILS. HAVE ENTERTAINED THE IDEA OF EXPANDING THE
FLOOD WATCH TO INCLUDE COUNTIES ACROSS THE SANDHILLS AND CENTRAL
PIEDMONT...BUT AS PRECIP HAS BECOME MORE CONVECTIVE IN NATURE...ANY
SUCH HEAVY PRECIP WOULD BE FAIRLY LOCALIZED. WITH A SECOND ROUND OF
SHOWERS AND POSSIBLY A FEW STRONG TO SEVERE STORMS EXPECTED LATER
THIS AFTERNOON AS WARM SECTOR BECOMES ESTABLISHED OVER THE
AREA...AREAS IN THE WATCH COULD STILL SEE LOCALIZED HEAVY AMOUNTS OF
ONE TO TWO INCHES. AS SUCH... WILL KEEP THE FLASH FLOOD WATCH
CONFINED TO THE WESTERN PIEDMONT.
SEVERE THREAT: AS TEMPS CLIMB INTO THE LOWER TO MID 70S AND SFC
DEWPOINTS APPROACH UPPER 60S TO NEAR 70...MODELS SHOW 500-1000 J/KG
OF MUCAPE(HIGHEST IN THE EAST)DEVELOPING OVER THE AREA. 40-50KT DEEP
SHEAR AND SHERBE VALUES APPROACHING 1.0 COULD SUPPORT A FEW STRONG
TO SVR WIND GUSTS AND POSSIBLY AN ISOLATED TORNADO. WILL CONTINUE TO
ADVERTISE SEVERE POTENTIAL ACROSS THE EASTERN HALF OF THE FORECAST
AREA IN THE HWO.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 355 AM WEDNESDAY...
ON THE WESTERN PERIPHERY OF ANOMALOUSLY STRONG SUB-TROPICAL RIDGING
CENTERED OVER THE WEST-CENTRAL ATLANTIC...SHORTWAVE RIDGING AND
ASSOCIATED HEIGHT RISES ALOFT WILL BUILD BEHIND THE MAIN SHORTWAVE
TROUGH LIFTING INTO EASTERN CANADA. WITH RIDGING ALOFT AND AN
ASSOCIATED PROBABLE CAPPING INVERSION DEPICTED ON NAM BUFR
SOUNDINGS...THE DAY WILL LIKELY BE A DRY ONE...THOUGH DIURNAL
HEATING OF THE UNSEASONABLY WARM (70S TO AROUND 80 IN IN THE I-95
CORRIDOR) AND HUMID BOUNDARY LAYER MAY ALLOW FOR SOME CU TO BYPASS
THE CAP AND GROW INTO ISOLATED SHOWERS/STORMS. IN ADDITION...AN
UPSTREAM QLCS...IN A REGION OF RESIDUALLY STRONG H85 MOISTURE
TRANSPORT DIRECTED INTO THE TN VALLEY...MAY SUPPORT THE EASTWARD
PROGRESSION OF A WEAKENING LONE OF SHOWERS AND STORMS TO CROSS THE
APPALACHIANS AND DRIFT INTO WESTERN NC...INCLUDING THE WESTERN
PIEDMONT EARLY THU NIGHT. INCREASING CINH WITH NOCTURNAL "COOLING"
INTO THE 60S FAVORS A DRY NIGHT OTHERWISE AND ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 410 AM WEDNESDAY...
THE STRONG SUB-TROPICAL RIDGE...WITH ANOMALOUSLY HIGH HEIGHTS AND
PRECIPITABLE WATER VALUES BETWEEN 200-300 PERCENT OF NORMAL FROM THE
SOUTHEASTERN UNITED STATES TO EAST-CENTRAL CANADA...WILL MAINTAIN A
VERY MILD-WARM REGIME ACROSS THE SOUTHEASTERN STATES THROUGHOUT THE
PERIOD...AND A WET ONE PRIMARILY NORTHWEST OF CENTRAL NC...AT LEAST
UNTIL LATE IN THE PERIOD. THE MAIN FORECAST UNCERTAINTY REMAINS THE
POSITIONING OF A WAVY FRONTAL ZONE FORECAST TO MEANDER ACROSS THE
MIDDLE ATLANTIC STATES...AND CONSEQUENTLY HOW MUCH SUPPRESSION OF
THE WARMTH OCCURS EAST OF THE APPALACHIANS...DICTATED BY A BATTLE
BETWEEN THE SUB-TROPICAL RIDGE AND CONFLUENT SPLIT FLOW
ALOFT/UNDERLYING POLAR HIGHS FORECAST TO DEVELOP ACROSS THE GREAT
LAKES AND NEW ENGLAND BY THIS WEEKEND.
THE TIMING OF POTENTIAL COLD FRONTAL SURGES INTO NC...IF THEY
OCCUR...ARE FAVORED LATE FRI NIGHT-SAT...AND AGAIN SUN NIGHT-
MON...WITH THE FORMER APPEARING INCREASINGLY UNLIKELY TO AFFECT
CENTRAL NC. OTHERWISE UNSEASONABLY MILD-WARM AND HUMID CONDITIONS IN
DEEP SOUTHERLY FLOW AROUND THE SUB-TROPICAL RIDGE WILL PREVAIL. THE
PRIMARY BRANCH OF THE NORTHERN STREAM WILL BE BLOCKED TO THE NW BY
THE SUB-TROPICAL RIDGING...SO FORCING FOR ASCENT AND ASSOCIATED
PRECIPITATION CHANCES WILL REMAIN LOW (GENERALLY AOB 20 PERCENT) AND
INSTEAD DRIVEN BY LOWER AMPLITUDE SOUTHERN STREAM PERTURBATIONS AND
ASSOCIATED SURGES OF LOW LEVEL THETA-E ADVECTION AND BRIEF EROSION
OF A CAPPING INVERSION FRI-SAT...WITH SAID CAPPING MORE LIKELY TO BE
OVERCOME BY DIURNAL HEATING IN AN AIRMASS MORE CHARACTERISTIC OF
APRIL-MAY THAN LATE DECEMBER.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 720 AM WEDNESDAY...
24 HOUR TAF PERIOD: WIDESPREAD ADVERSE AVIATION CONDITIONS WILL
PERSIST THROUGH THE 24 HOUR TAF PERIOD AS AN ANOMALOUSLY MOIST AND
WARM AIRMASS ADVECTS INTO THE AREA.
CEILINGS HAVE IMPROVED TO MVFR AND EVEN VFR ACROSS CENTRAL AND EASTERN
PORTIONS OF THE FORECAST AS WARM SECTOR OVERTAKES THE AREA FROM THE
SOUTH. HOWEVER WE ARE STILL SEEING SOME IFR AND LIFR VISIBILITY
RESTRICTIONS WITH THE HEAVIER SHOWERS. CONDITIONS WILL BE UP AND
DOWN TODAY...BOUNCING FROM VFR TO IFR WITH SCATTERED TO NUMEROUS
SHOWERS AND STORMS EXPECTED THIS AFTERNOON AND EVENING AS WE
DESTABILIZE.
CONDITIONS WILL BE SLOWER TO IMPROVE AT KINT AND KGSO...PERHAPS
IMPROVING TO MVFR BY THE EARLY AFTERNOON AS THE WARM AIR AND
INCREASING INSTABILITY FINALLY HELP TO SCOUR OUT THE LINGERING
WEDGE AIRMASS.
ADDITIONALLY...SOUTHERLY WINDS WILL INCREASE...GUSTING UP TO 20 TO
25 KTS...STRONGEST IN THE EAST.
CEILINGS SHOULD QUICKLY DETERIORATE TO IFR TO LIFR ACROSS THE AREA THIS
EVENING...THOUGH A STEADY 10 TO 15KT SOUTHERLY BREEZE SHOULD
PRECLUDE WIDESPREAD FOG DEVELOPMENT.
OUTLOOK: A MOIST DEEP SOUTHWESTERLY FLOW DOWNSTREAM OF THE LONG WAVE
TROUGH IN PLACE ACROSS THE CENTRAL CONUS WILL SUPPORT A PROLONGED
PERIOD OF ADVERSE AVIATION CONDITIONS THROUGH MUCH OF THE PERIOD.
SUB-VFR CONDITIONS IN LOW CLOUDS/STRATUS WILL ALSO BE LIKELY EACH
MORNING... ALONG WITH THE TREAT OF SOME SHOWERS EACH DAY.
&&
.CLIMATE...
HERE ARE THE AREA RECORD MAXIMUMS AND HIGH MINIMUMS FOR DECEMBER 24TH
AND 25TH. RECORDS HAVE BEEN KEPT IN THE GREENSBORO AREA SINCE
1903... IN THE RALEIGH AREA SINCE 1887... AND IN THE FAYETTEVILLE
AREA SINCE 1910.
DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)
DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...2
NEAR TERM...CBL
SHORT TERM...2
LONG TERM...2
AVIATION...CBL
CLIMATE...HARTFIELD/BLAES
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
641 AM EST WED DEC 23 2015
.SYNOPSIS...
NEAR RECORD WARMTH FOR MOST OF THE UPCOMING WEEK DESPITE SOME
FAIRLY CLOUDY CONDITIONS. HIGH CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS TODAY...WITH COVERAGE BECOMING MORE ISOLATED DURING
THURSDAY. DRY MID LEVEL AIR SHOULD SHUT DOWN SHOWER ACTIVITY
FRIDAY AND OVER THE WEEKEND AS HIGH PRESSURE OFF THE SOUTHEAST
COAST CONTINUES TO RIDGE ACROSS THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM WEDNESDAY...LATEST LOCAL AND MOSAIC RADAR DATA
INDICATES PCPN CONTINUES TO STREAM UP TO THE NNE ACROSS THE
CAROLINAS. THIS IS IN RESPONSE TO A MIDLEVEL S/W TROF LIFTING N TO
NE WITHIN STRONG MID-LEVEL SSW FLOW. THE BEST OR MAIN DYNAMICS
FROM THIS S/W TROF STAY WEST OF THE ILM CWA TODAY...BUT MODELS
INDICATE THE TRAILING MID- LEVEL SHEARED AXIS WILL MAKE ITS WAY TO
THE CAROLINA COASTS BY LATE THIS EVENING. DEEP GULF OF MEXICO AND
ATLANTIC MOISTURE WILL CONTINUE TO PUMP ACROSS THE ILM CWA WITH
PROGGED PWS IN THE 1.5 TO 2.00 INCH RANGE. TO PUT IT ALL
TOGETHER...THE FA WILL BE UNDER THE LIKELY TO CATEGORICAL POP
THREAT FROM SHOWERS AND EMBEDDED ISOLATED THUNDERSTORMS TODAY THRU
THIS EVENING. AVBL CAPE OF 1K TO POSSIBLY 1.25K WILL BE LOW
ALTHOUGH BETTER THAN YESTERDAY...AND WITH PROGGED LAPSE RATES
REMAINING SUSPECT...HAVE KEPT THE TSTORM THREAT TO ISOLATED AT
BEST FOR NOW.
NO FLOOD WATCHES ARE FORECAST FOR THE ILM CWA. HOWEVER...ANY
TRAINING OF HEAVY SHOWERS OVER AREAS RECEIVING A GOOD DOSE OF
RAINFALL FROM TUESDAY...COULD RESULT IN PONDING OF WATER
ESPECIALLY ACROSS LOW LYING AREAS AND PRONE ROADWAYS. WILL
HIGHLIGHT THIS IN THE HAZARDOUS WEATHER OUTLOOK.
TEMPS WILL CONTINUE TO RUN 15 TO 25+ DEGREES ABOVE NORMAL.
TODAYS HIGHS IN THE MID TO UPPER 70S AND TONIGHTS LOWS IN THE MID
TO UPPER 60S. THIS SOUNDS MORE LIKE A MID FALL OR MID SPRING TEMP
FORECAST. OF NOTE...NORMAL HIGHS ARE IN THE MID TO UPPER 50S AND
NORMAL LOWS ARE IN LOW TO MID 30S.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
AS OF 3 AM WEDNESDAY...PATTERN CONSISTENCY MORE TYPICAL OF THE WARM
SEASON IN PLACE THROUGH THE PERIOD WITH UPPER RIDGE AND BERMUDA HIGH-
LIKE SURFACE LOCKING INTO PLACE. NO SURPRISE THEN THAT THE
ATMOSPHERE WILL BE PRIMED WITH BOTH COPIOUS WARMTH AND MOISTURE. THE
WARMTH WILL MANIFEST ITSELF AS, WELL, WARMTH. NEAR RECORD VALUES, IN
FACT. THE MOISTURE WILL MOSTLY TAKE FORM OF FAIRLY WIDESPREAD CLOUD
COVER BUT ALSO SOME VERY LOW RAIN CHANCES. THESE LOW RAIN CHANCES
WILL BE FOCUSED ALONG WESTERN ZONES ON THURSDAY AS A WEAK VORT
STREAKS BY COINCIDING WITH A RIBBON OF THE DEEPEST MOISTURE. (THE
OFFSHORE QPF POSSIBLY AFFECTING THE COAST DEPICTED ON THE WRF SEEMS
IMPLAUSIBLE GIVEN THE WARM AIR BEING STABILIZED BY THE CHILLY SSTS).
IT MAY THEN SHIFT TO NORTHERN AND WESTERN ZONES AS A COLD FRONT
BACKDOORS ITS WAY TO THE NC/VA BORDER. OVERALL THOUGH FEEL THAT
FRIDAY MOSTLY RAIN-FREE AS THE RIDGE ALOFT BUILDS WESTWARD PUMPING
HEIGHT RISES INTO THE REGION SUPPRESSING WHAT MAY ALSO BE AN ATTEMPT
AT SEA BREEZE AND WEST WALL CONVECTION SHOWN IN SOME MODELS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY... MODERATELY HIGHLY AMPLIFIED PATTERN IN PLACE
FOR THE ENTIRE PERIOD. STALWART RIDGE ALOFT HOLDS JUST EAST OF THE
BAHAMAS WHILE CUTOFF UPPER LOW EJECTS FROM THE SOUTHWESTERN U.S.
INTO THE OHIO VALLEY SATURDAY THROUGH MONDAY. TEMPERATURES WILL
CONTINUE THEIR IMPRESSIVE DEVIATIONS FROM CLIMATOLOGY WITH DAYTIME
HIGHS NEARLY 20 DEGREES ABOVE NORMAL AND NIGHTTIME DEVIATIONS OFTEN
EVEN LARGER AS CLOUD COVER LINGERS BENEATH THE SUBSIDENCE INVERSION
BORNE OF THE UPPER RIDGE. RAIN CHANCES ARE BOTH TOUGH TO RULE OUT
WITH SO MUCH LOW LEVEL MOISTURE BUT ALSO HARD TO GET EXCITED ABOUT
DUE TO THE UPPER RIDGE. THE EXCEPTION MAY BE MONDAY WHEN THE RIDGE
GETS BEAT DOWN SUFFICIENTLY FOR SOME HEIGHT FALLS LOCALLY. THEN
AGAIN, THIS USUALLY OCCURS MORE SLOWLY THAN PORTRAYED IN GUIDANCE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...THE HRRR MODEL INITIALIZED REASONABLY WELL AND BRINGS
THE FOCUS OF THE PRECIP TO THE COAST BY LATE MORNING. CEILINGS ARE
A BIT ALL OVER THE PLACE...AS WELL AS THE VISIBILITIES IN THE HEAVIER
PRECIP. CEILINGS TODAY WILL BOUNCE FROM IFR TO VFR WITH VISIBILITIES
BRIEFLY IFR IN THE HEAVIER EMBEDDED CONVECTION. MID AND HIGH LEVEL
MOISTURE WILL CONTINUE THROUGH THE END OF THE FORECAST PERIOD. THE
SOUTHERLY GRADIENT WILL REMAIN TIGHT...WITH GUST TO 20 KTS EXPECTED
AT ANY TIME DURING THE NEXT 24 HOURS. A RUMBLE OF THUNDER CAN NOT
BE RULED OUT.
EXTENDED OUTLOOK...POSSIBLE MVFR TO IFR CONDITIONS IN PCPN AND LOW
CEILINGS FROM THROUGH THURSDAY...OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM WEDNESDAY...SMALL CRAFT ADVISORY CONDITIONS EXPECTED
THRU THIS PERIOD. SFC PRESSURE PATTERN THRU TONIGHT TO YIELD SSE-S
WIND DIRECTIONS THIS MORNING...BECOMING S-SSW BY MIDDAY AND
CONTINUING THRU TONIGHT. A TIGHTENING SFC PG WILL DEVELOP ACROSS
THE LOCAL WATERS EARLY TODAY...AND WILL REMAIN TIGHTENED THRU
TONIGHT. THIS WILL YIELD 10 TO 20 KT SUSTAINED WIND SPEEDS THIS
MORNING THAT COULD OCCASIONALLY REACH 15 TO 25 KT FROM MIDDAY
THROUGH THIS EVENING. IN ADDITION...GUSTS COULD APPROACH 30 KT
ESPECIALLY OVER SSTS THAT ARE WELL INTO THE 60S. LOCAL SSTS HAVE
ALREADY SHOWN AN INCREASE FROM 24 HRS AGO DUE TO THE ONSHORE FLOW
WITH LOW 60S COMMON NOW. EXPECT THIS SLOW INCREASING TREND TO
CONTINUE WITH LOW TO MID 60S BECOMING MORE COMMON BY EARLY THU.
AS A RESULT...SEA FOG DEVELOPMENT SHOULD NOT BE AN ISSUE DURING
THIS TIME PERIOD.
SIGNIFICANT SEAS WILL BUILD TO 4 TO 7 FT TODAY...AND PEAK 5 TO
8 FT LATE THIS AFTN THRU TONIGHT. THE 8 FOOTERS WILL PRIMARILY
OCCUR OVER THE WATERS OFF CAPE FEAR. WIND DRIVEN WAVES AT 6 TO 7
SECOND PERIODS WILL DOMINATE THE SEAS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY... PERIOD INITIALIZES WITH A SMALL CRAFT
ADVISORY IN A MODERATELY PINCHED SOUTHWESTERLY GRADIENT FLOW WITH
SOME EMBEDDED ENERGY. A SLIGHT WESTWARD EXTENSION OF A RIDGE AXIS
INTO GA/FL ON THE PART OF THE OFFSHORE HIGH LEADS TO A SLIGHT
WEAKENING OF THE GRADIENT LATER THURSDAY INTO THURSDAY NIGHT AND
FRIDAY. WIND REMAINS MOSTLY SOUTHWESTERLY ON FRIDAY BUT IN A
LIGHTENED STATE. THE RIDGE AXIS SHOULD ALSO DISRUPT THE SWELL
ENERGY A BIT TO HELP FURTHER REDUCE DOMINANT WAVE HEIGHT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY... MUCH MORE OF A WARM SEASON PATTERN IN PLACE
WITH A WEST ATLANTIC HIGH DOMINATING AND A COMPLETE LACK OF ANY
FRONTS. THE MAIN DIFFERENCE PATTERN-WISE WILL BE THAT THE HIGH WILL
BE WEAKER AND FURTHER WEST THAN WHAT IS NORMALLY OBSERVED IN THE
WARM SEASON. AS SUCH WIND SPEEDS MAY WELL BE CAPPED AT 10KT AS THE
DIRECTION REMAINS SOUTH TO SOUTHWESTERLY. SEAS WILL AVERAGE 2 TO 3
AND OCCASIONALLY (WELL OFFSHORE) 4 FT.
&&
.TIDES/COASTAL FLOODING...
AS OF 630 AM WEDNESDAY...LATEST MODELS INDICATE THE GAGE READING
ALONG THE CAPE FEAR RIVER OF DOWNTOWN WILMINGTON WILL REACH 5.70
FT MLLW AT HIGH TIDE THIS MORNING...WHICH OCCURS AROUND 730 AM.
THIS SURPASSES THE MINOR COASTAL FLOODING THRESHOLD OF 5.50 FT
MLLW. AS A RESULT...A COASTAL FLOOD ADVISORY HAS BEEN ISSUED FOR
LOCATIONS BORDERING ALONG THE LOWER CAPE FEAR RIVER FROM
WILMINGTON SOUTHWARD. LOOK FOR SHALLOW FLOODING TO OCCUR IN A 2
HOUR WINDOW CENTERED AT HIGH TIDE...ROUGHLY BETWEEN 630 AM AND 830
AM.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...COASTAL FLOOD ADVISORY UNTIL 9 AM EST THIS MORNING FOR NCZ107.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR AMZ250-252-
254-256-270-274.
&&
$$
SYNOPSIS...DCH
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...HDL
TIDES/COASTAL FLOODING...DCH
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
610 AM EST WED DEC 23 2015
.SYNOPSIS...
NEAR RECORD WARMTH FOR MOST OF THE UPCOMING WEEK DESPITE SOME
FAIRLY CLOUDY CONDITIONS. HIGH CHANCE FOR SHOWERS AND ISOLATED
THUNDERSTORMS TODAY...WITH COVERAGE BECOMING MORE ISOLATED DURING
THURSDAY. DRY MID LEVEL AIR SHOULD SHUT DOWN SHOWER ACTIVITY
FRIDAY AND OVER THE WEEKEND AS HIGH PRESSURE OFF THE SOUTHEAST
COAST CONTINUES TO RIDGE ACROSS THE AREA.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 330 AM WEDNESDAY...LATEST RADAR MOSAIC DATA INDICATES PCPN
CONTINUES TO DEVELOPMENT AND MOVE ACROSS THE CAROLINAS. THIS IS
IN RESPONSE TO A MIDLEVEL S/W TROF LIFTING N TO NE WITHIN STRONG
MID-LEVEL SSW FLOW. THE BEST OR MAIN DYNAMICS FROM THIS S/W TROF
STAY WEST OF THE ILM CWA TODAY...BUT MODELS INDICATE THE TRAILING
MID-LEVEL SHEARED AXIS WILL MAKE ITS WAY TO THE CAROLINA COASTS BY
LATE THIS EVENING. DEEP GULF OF MEXICO AND ATLANTIC MOISTURE WILL
CONTINUE TO PUMP ACROSS THE ILM CWA WITH PROGGED PWS IN THE 1.5 TO
2.00 INCH RANGE. TO PUT IT ALL TOGETHER...THE FA WILL BE UNDER THE
LIKELY TO CATEGORICAL POP THREAT FROM SHOWERS AND EMBEDDED
ISOLATED THUNDERSTORMS TODAY THRU THIS EVENING. AVBL CAPE OF 1K TO
POSSIBLY 1.25K WILL BE LOW ALTHOUGH BETTER THAN YESTERDAY...AND
WITH PROGGED LAPSE RATES REMAINING SUSPECT... HAVE KEPT THE TSTORM
THREAT TO ISOLATED AT BEST FOR NOW.
NO FLOOD WATCHES ARE FORECAST FOR THE ILM CWA. HOWEVER...ANY
TRAINING OF HEAVY SHOWERS OVER AREAS RECEIVING A GOOD DOSE OF
RAINFALL FROM TUESDAY...COULD RESULT IN PONDING OF WATER
ESPECIALLY ACROSS LOW LYING AREAS AND PRONE ROADWAYS. WILL
HIGHLIGHT THIS IN THE HAZARDOUS WEATHER OUTLOOK.
TEMPS WILL CONTINUE TO RUN 15 TO 25+ DEGREES ABOVE NORMAL.
TODAYS HIGHS IN THE MID TO UPPER 70S AND TONIGHTS LOWS IN THE MID
TO UPPER 60S. THIS SOUNDS MORE LIKE A MID FALL OR MID SPRING TEMP
FORECAST. OF NOTE...NORMAL HIGHS ARE IN THE MID TO UPPER 50S AND
NORMAL LOWS ARE IN LOW TO MID 30S.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH THURSDAY NIGHT/...
AS OF 3 AM WEDNESDAY...PATTERN CONSISTENCY MORE TYPICAL OF THE WARM
SEASON IN PLACE THROUGH THE PERIOD WITH UPPER RIDGE AND BERMUDA HIGH-
LIKE SURFACE LOCKING INTO PLACE. NO SURPRISE THEN THAT THE
ATMOSPHERE WILL BE PRIMED WITH BOTH COPIOUS WARMTH AND MOISTURE. THE
WARMTH WILL MANIFEST ITSELF AS, WELL, WARMTH. NEAR RECORD VALUES, IN
FACT. THE MOISTURE WILL MOSTLY TAKE FORM OF FAIRLY WIDESPREAD CLOUD
COVER BUT ALSO SOME VERY LOW RAIN CHANCES. THESE LOW RAIN CHANCES
WILL BE FOCUSED ALONG WESTERN ZONES ON THURSDAY AS A WEAK VORT
STREAKS BY COINCIDING WITH A RIBBON OF THE DEEPEST MOISTURE. (THE
OFFSHORE QPF POSSIBLY AFFECTING THE COAST DEPICTED ON THE WRF SEEMS
IMPLAUSIBLE GIVEN THE WARM AIR BEING STABILIZED BY THE CHILLY SSTS).
IT MAY THEN SHIFT TO NORTHERN AND WESTERN ZONES AS A COLD FRONT
BACKDOORS ITS WAY TO THE NC/VA BORDER. OVERALL THOUGH FEEL THAT
FRIDAY MOSTLY RAIN-FREE AS THE RIDGE ALOFT BUILDS WESTWARD PUMPING
HEIGHT RISES INTO THE REGION SUPPRESSING WHAT MAY ALSO BE AN ATTEMPT
AT SEA BREEZE AND WEST WALL CONVECTION SHOWN IN SOME MODELS.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 3 AM WEDNESDAY... MODERATELY HIGHLY AMPLIFIED PATTERN IN PLACE
FOR THE ENTIRE PERIOD. STALWART RIDGE ALOFT HOLDS JUST EAST OF THE
BAHAMAS WHILE CUTOFF UPPER LOW EJECTS FROM THE SOUTHWESTERN U.S.
INTO THE OHIO VALLEY SATURDAY THROUGH MONDAY. TEMPERATURES WILL
CONTINUE THEIR IMPRESSIVE DEVIATIONS FROM CLIMATOLOGY WITH DAYTIME
HIGHS NEARLY 20 DEGREES ABOVE NORMAL AND NIGHTTIME DEVIATIONS OFTEN
EVEN LARGER AS CLOUD COVER LINGERS BENEATH THE SUBSIDENCE INVERSION
BORNE OF THE UPPER RIDGE. RAIN CHANCES ARE BOTH TOUGH TO RULE OUT
WITH SO MUCH LOW LEVEL MOISTURE BUT ALSO HARD TO GET EXCITED ABOUT
DUE TO THE UPPER RIDGE. THE EXCEPTION MAY BE MONDAY WHEN THE RIDGE
GETS BEAT DOWN SUFFICIENTLY FOR SOME HEIGHT FALLS LOCALLY. THEN
AGAIN, THIS USUALLY OCCURS MORE SLOWLY THAN PORTRAYED IN GUIDANCE.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
AS OF 12Z...THE HRRR MODEL INITIALIZED REASONABLY WELL AND BRINGS
THE FOCUS OF THE PRECIP TO THE COAST BY LATE MORNING. CEILINGS ARE
A BIT ALL OVER THE PLACE...AS WELL AS THE VISIBILITIES IN THE HEAVIER
PRECIP. CEILINGS TODAY WILL BOUNCE FROM IFR TO VFR WITH VISIBILITIES
BRIEFLY IFR IN THE HEAVIER EMBEDDED CONVECTION. MID AND HIGH LEVEL
MOISTURE WILL CONTINUE THROUGH THE END OF THE FORECAST PERIOD. THE
SOUTHERLY GRADIENT WILL REMAIN TIGHT...WITH GUST TO 20 KTS EXPECTED
AT ANY TIME DURING THE NEXT 24 HOURS. A RUMBLE OF THUNDER CAN NOT
BE RULED OUT.
EXTENDED OUTLOOK...POSSIBLE MVFR TO IFR CONDITIONS IN PCPN AND LOW
CEILINGS FROM THROUGH THURSDAY...OTHERWISE EXPECT VFR.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 330 AM WEDNESDAY...SMALL CRAFT ADVISORY CONDITIONS EXPECTED
THRU THIS PERIOD. SFC PRESSURE PATTERN THRU TONIGHT TO YIELD
SSE-S DIRECTIONS THIS MORNING...BECOMING S-SSW BY MIDDAY AND
CONTINUING THRU TONIGHT. A TIGHTENING SFC PG WILL DEVELOP ACROSS
THE LOCAL WATERS TODAY...AND WILL REMAIN TIGHTENED THRU TONIGHT.
THIS WILL YIELD 10 TO 20 KT SUSTAINED WIND SPEEDS THIS MORNING
THAT COULD OCCASIONALLY REACH 15 TO 25 KT FROM MIDDAY THROUGH THIS
EVENING. IN ADDITION...GUSTS COULD APPROACH 30 KT ESPECIALLY OVER
SSTS THAT ARE WELL INTO THE 60S. LOCAL SSTS HAVE ALREADY SHOWN AN
INCREASE FROM 24 HRS AGO DUE TO THE ONSHORE FLOW WITH LOW 60S
COMMON NOW. EXPECT THIS SLOW INCREASING TREND TO CONTINUE WITH LOW
TO MID 60S BECOMING MORE COMMON BY THU. AS A RESULT...SEA FOG
DEVELOPMENT SHOULD NOT BE AN ISSUE DURING THIS TIME PERIOD.
SIGNIFICANT SEAS WILL BUILD TO 4 TO 7 FT TODAY...AND PEAK 5 TO
8 FT LATE THIS AFTN THRU TONIGHT. THE 8 FOOTERS WILL PRIMARILY
OCCUR OVER THE WATERS OFF CAPE FEAR. WIND DRIVEN WAVES AT 6 TO 7
SECOND PERIODS WILL DOMINATE THE SEAS.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 3 AM WEDNESDAY... PERIOD INITIALIZES WITH A SMALL CRAFT
ADVISORY IN A MODERATELY PINCHED SOUTHWESTERLY GRADIENT FLOW WITH
SOME EMBEDDED ENERGY. A SLIGHT WESTWARD EXTENSION OF A RIDGE AXIS
INTO GA/FL ON THE PART OF THE OFFSHORE HIGH LEADS TO A SLIGHT
WEAKENING OF THE GRADIENT LATER THURSDAY INTO THURSDAY NIGHT AND
FRIDAY. WIND REMAINS MOSTLY SOUTHWESTERLY ON FRIDAY BUT IN A
LIGHTENED STATE. THE RIDGE AXIS SHOULD ALSO DISRUPT THE SWELL
ENERGY A BIT TO HELP FURTHER REDUCE DOMINANT WAVE HEIGHT.
LONG TERM /SATURDAY THROUGH SUNDAY/...
AS OF 3 AM WEDNESDAY... MUCH MORE OF A WARM SEASON PATTERN IN PLACE
WITH A WEST ATLANTIC HIGH DOMINATING AND A COMPLETE LACK OF ANY
FRONTS. THE MAIN DIFFERENCE PATTERN-WISE WILL BE THAT THE HIGH WILL
BE WEAKER AND FURTHER WEST THAN WHAT IS NORMALLY OBSERVED IN THE
WARM SEASON. AS SUCH WIND SPEEDS MAY WELL BE CAPPED AT 10KT AS THE
DIRECTION REMAINS SOUTH TO SOUTHWESTERLY. SEAS WILL AVERAGE 2 TO 3
AND OCCASIONALLY (WELL OFFSHORE) 4 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST THURSDAY FOR AMZ250-252-
254-256-270-274.
&&
$$
SYNOPSIS...DCH
NEAR TERM...DCH
SHORT TERM...MBB
LONG TERM...MBB
AVIATION...43
MARINE...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
415 AM EST WED DEC 23 2015
.SYNOPSIS...A WEDGE FRONT WILL REMAIN QUASI-STATIONARY OVER THE
PIEDMONT EARLY TODAY...THEN BE OVERTAKEN BY A MARITIME WARM FRONT
THAT WILL SURGE ACROSS THE CAROLINAS AND SOUTHEASTERN VIRGINIA THIS
AFTERNOON. ANOMALOUSLY STRONG SUB-TROPICAL HIGH PRESSURE OVER THE
WEST-CENTRAL ATLANTIC OCEAN WILL THEN DIRECT UNSEASONABLY WARM AND
MOIST SOUTHERLY FLOW THROUGHOUT THE SOUTHEASTERN UNITED STATES
THROUGH CHRISTMAS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 355 AM WEDNESDAY...
...FLASH FLOOD WATCH CONTINUES ACROSS THE WESTERN PIEDMONT...
A SHORTWAVE TROUGH EMBEDDED WITHIN LARGER-SCALE TROUGH SITUATED
ACROSS MUCH OF THE CONUS WILL ADVANCE NEWD FROM THE SRN PLAINS
TOWARDS THE UPPER GREAT LAKES. ACCOMPANYING DEEPENING SFC LOW WILL
FOLLOW SUITE...TRACKING NEWD FROM THE MID-MO VALLEY TO THE UPPER MS
VALLEY BY LATE AFTERNOON. WHILE THESE FEATURES ARE A LITTLE WAYS
FROM HOME...DEEP SOUTHERLY FLOW ON THE EAST SIDE OF THE TROUGH WILL
ADVECT MODIFIED GULF AIR NORTHWARD INTO THE AREA...BRINGING
ANOMALOUS MOIST AND WARM AIR INTO THE AREA. PWATS ARE FORECAST TO
INCREASE TO 1.6-1.9"(4-5 STANDARD DEVIATIONS ABOVE NORMAL)...WHICH
WILL RIVAL MAX DECEMBER VALUES AT KGSO(1.65"-DATING BACK TO
1948)...WHILE TONIGHTS LOW TEMPERATURES WILL STRUGGLE TO DROP OUT OF
THE 70S AT MOST LOCATIONS...AGAIN HAVING A GOOD CHANCE OF MATCHING
THE ALL-TIME WARMEST DECEMBER MINIMUM TEMPERATURE ON RECORD(RDU-
69...FAY-69...GSO-65).
TWO MAIN CONCERNS ARE: 1)PERIODS OF MODERATE TO HEAVY RAINFALL THAT
MAY RESULT IN BOTH FLASHING FLOODING AS WELL AS MINOR FLOODING
ON AREAS RIVERS AND CREEKS AND 2)ISOLATED THREAT OF SEVERE STORMS
LATER TODAY.
FLOOD THREAT: LATEST RADAR TRENDS SHOW AN UPTICK IN CONVECTION
BREAKING OUT ACROSS THE AREA...FUELED BY A STRENGTHENING 50-60KT S-
SW LOW-LEVEL FLOW TO THE EAST OF THE AMPLIFYING SYSTEM TO OUR WEST.
MOST RECENT HRRR SIMULATIONS ARE HANDLING THE CONVECTION
BEST...DEPICTING THE HEAVIEST RAINFALL THIS MORNING ALONG AND EAST
OF HIGHWAY 1. THE AFOREMENTIONED HIGH MOISTURE ANOMALIES WILL
SUPPORT THE POTENTIAL FOR 1.5-2.0"/HOUR RAINFALL RATES OVER THESE
AREAS THIS MORNING THAT WOULD LIKELY CAUSE SOME LOCALIZED FLOODING
GIVEN SATURATED SOILS. HAVE ENTERTAINED THE IDEA OF EXPANDING THE
FLOOD WATCH TO INCLUDE COUNTIES ACROSS THE SANDHILLS AND CENTRAL
PIEDMONT...BUT AS PRECIP HAS BECOME MORE CONVECTIVE IN NATURE...ANY
SUCH HEAVY PRECIP WOULD BE FAIRLY LOCALIZED. WITH A SECOND ROUND OF
SHOWERS AND POSSIBLY A FEW STRONG TO SEVERE STORMS EXPECTED LATER
THIS AFTERNOON AS WARM SECTOR BECOMES ESTABLISHED OVER THE
AREA...AREAS IN THE WATCH COULD STILL SEE LOCALIZED HEAVY AMOUNTS OF
ONE TO TWO INCHES. AS SUCH... WILL KEEP THE FLASH FLOOD WATCH
CONFINED TO THE WESTERN PIEDMONT.
SEVERE THREAT: AS TEMPS CLIMB INTO THE LOWER TO MID 70S AND SFC
DEWPOINTS APPROACH UPPER 60S TO NEAR 70...MODELS SHOW 500-1000 J/KG
OF MUCAPE(HIGHEST IN THE EAST)DEVELOPING OVER THE AREA. 40-50KT DEEP
SHEAR AND SHERBE VALUES APPROACHING 1.0 COULD SUPPORT A FEW STRONG
TO SVR WIND GUSTS AND POSSIBLY AN ISOLATED TORNADO. WILL CONTINUE TO
ADVERTISE SEVERE POTENTIAL ACROSS THE EASTERN HALF OF THE FORECAST
AREA IN THE HWO.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 355 AM WEDNESDAY...
ON THE WESTERN PERIPHERY OF ANOMALOUSLY STRONG SUB-TROPICAL RIDGING
CENTERED OVER THE WEST-CENTRAL ATLANTIC...SHORTWAVE RIDGING AND
ASSOCIATED HEIGHT RISES ALOFT WILL BUILD BEHIND THE MAIN SHORTWAVE
TROUGH LIFTING INTO EASTERN CANADA. WITH RIDGING ALOFT AND AN
ASSOCIATED PROBABLE CAPPING INVERSION DEPICTED ON NAM BUFR
SOUNDINGS...THE DAY WILL LIKELY BE A DRY ONE...THOUGH DIURNAL
HEATING OF THE UNSEASONABLY WARM (70S TO AROUND 80 IN IN THE I-95
CORRIDOR) AND HUMID BOUNDARY LAYER MAY ALLOW FOR SOME CU TO BYPASS
THE CAP AND GROW INTO ISOLATED SHOWERS/STORMS. IN ADDITION...AN
UPSTREAM QLCS...IN A REGION OF RESIDUALLY STRONG H85 MOISTURE
TRANSPORT DIRECTED INTO THE TN VALLEY...MAY SUPPORT THE EASTWARD
PROGRESSION OF A WEAKENING LONE OF SHOWERS AND STORMS TO CROSS THE
APPALACHIANS AND DRIFT INTO WESTERN NC...INCLUDING THE WESTERN
PIEDMONT EARLY THU NIGHT. INCREASING CINH WITH NOCTURNAL "COOLING"
INTO THE 60S FAVORS A DRY NIGHT OTHERWISE AND ELSEWHERE.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 410 AM WEDNESDAY...
THE STRONG SUB-TROPICAL RIDGE...WITH ANOMALOUSLY HIGH HEIGHTS AND
PRECIPITABLE WATER VALUES BETWEEN 200-300 PERCENT OF NORMAL FROM THE
SOUTHEASTERN UNITED STATES TO EAST-CENTRAL CANADA...WILL MAINTAIN A
VERY MILD-WARM REGIME ACROSS THE SOUTHEASTERN STATES THROUGHOUT THE
PERIOD...AND A WET ONE PRIMARILY NORTHWEST OF CENTRAL NC...AT LEAST
UNTIL LATE IN THE PERIOD. THE MAIN FORECAST UNCERTAINTY REMAINS THE
POSITIONING OF A WAVY FRONTAL ZONE FORECAST TO MEANDER ACROSS THE
MIDDLE ATLANTIC STATES...AND CONSEQUENTLY HOW MUCH SUPPRESSION OF
THE WARMTH OCCURS EAST OF THE APPALACHIANS...DICTATED BY A BATTLE
BETWEEN THE SUB-TROPICAL RIDGE AND CONFLUENT SPLIT FLOW
ALOFT/UNDERLYING POLAR HIGHS FORECAST TO DEVELOP ACROSS THE GREAT
LAKES AND NEW ENGLAND BY THIS WEEKEND.
THE TIMING OF POTENTIAL COLD FRONTAL SURGES INTO NC...IF THEY
OCCUR...ARE FAVORED LATE FRI NIGHT-SAT...AND AGAIN SUN NIGHT-
MON...WITH THE FORMER APPEARING INCREASINGLY UNLIKELY TO AFFECT
CENTRAL NC. OTHERWISE UNSEASONABLY MILD-WARM AND HUMID CONDITIONS IN
DEEP SOUTHERLY FLOW AROUND THE SUB-TROPICAL RIDGE WILL PREVAIL. THE
PRIMARY BRANCH OF THE NORTHERN STREAM WILL BE BLOCKED TO THE NW BY
THE SUB-TROPICAL RIDGING...SO FORCING FOR ASCENT AND ASSOCIATED
PRECIPITATION CHANCES WILL REMAIN LOW (GENERALLY AOB 20 PERCENT) AND
INSTEAD DRIVEN BY LOWER AMPLITUDE SOUTHERN STREAM PERTURBATIONS AND
ASSOCIATED SURGES OF LOW LEVEL THETA-E ADVECTION AND BRIEF EROSION
OF A CAPPING INVERSION FRI-SAT...WITH SAID CAPPING MORE LIKELY TO BE
OVERCOME BY DIURNAL HEATING IN AN AIRMASS MORE CHARACTERISTIC OF
APRIL-MAY THAN LATE DECEMBER.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 100 WEDNESDAY...
24 HOUR TAF PERIOD: WIDESPREAD ADVERSE AVIATION CONDITIONS WILL
PERSIST THROUGH THE 24 HOUR TAF PERIOD AS AN ANOMALOUSLY MOIST AND
WARM AIRMASS ADVECTS INTO THE AREA.
WIDESPREAD LIFR CIGS AND VSBYS IN DRIZZLE AND FOG HAVE OVERTAKEN THE
AREA. HOWEVER...WITH NEXT ROUND OF SHOWERS SPREADING NORTH INTO THE
AREA BETWEEN 06 TO 12Z...VSBYS SHOULD IMPROVE TO MVFR AND QUITE
POSSIBLY VFR. CEILINGS WILL BE MUCH SLOWER TO IMPROVE...REMAINING
LIFR ACROSS THE AREA THROUGH MID TO LATE MORNING...WITH SOME
TEMPORARY IMPROVEMENT TO MVFR OR VFR...PARTICULARLY AT KRDU/KFAY AND
KRWI THIS AFTERNOON AS WARM SECTOR OVERSPREADS THE AREA. SCATTERED
TO NUMEROUS SHOWERS AND POSSIBLY A FEW THUNDERSTORMS ARE EXPECTED
THROUGH THE AFTERNOON AND EVENING AS WE DESTABILIZE. SOUTHERLY WINDS
WILL INCREASE...GUSTING UP TO 20 TO 25 KTS.
CEILINGS COULD QUICKLY TO IFR TO LIFR ACROSS THE AREA THIS
EVENING...THOUGH A STEADY 10 TO 15KT SOUTHERLY BREEZE SHOULD
PRECLUDE WIDESPREAD FOG DEVELOPMENT.
OUTLOOK: A MOIST DEEP SOUTHWESTERLY FLOW DOWNSTREAM OF THE LONG WAVE
TROUGH IN PLACE ACROSS THE CENTRAL CONUS WILL SUPPORT A PROLONGED
PERIOD OF ADVERSE AVIATION CONDITIONS THROUGH MUCH OF THE PERIOD.
SUB-VFR CONDITIONS IN LOW CLOUDS/STRATUS WILL ALSO BE LIKELY EACH
MORNING... ALONG WITH THE TREAT OF SOME SHOWERS EACH DAY.
&&
.CLIMATE...
HERE ARE THE AREA RECORD MAXIMUMS AND HIGH MINIMUMS FOR DECEMBER 24TH
AND 25TH. RECORDS HAVE BEEN KEPT IN THE GREENSBORO AREA SINCE
1903... IN THE RALEIGH AREA SINCE 1887... AND IN THE FAYETTEVILLE
AREA SINCE 1910.
DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)
DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...2
NEAR TERM...CBL
SHORT TERM...2
LONG TERM...2
AVIATION...CBL
CLIMATE...HARTFIELD/BLAES
AREA FORECAST DISCUSSION
NWS RALEIGH NC
355 AM EST WED DEC 23 2015
.SYNOPSIS...AN UNSEASONABLY WARM AND MOIST AIR MASS OVER
CENTRAL NC WILL YIELD ABUNDANT RAINFALL ACROSS THE REGION THROUGH
THURSDAY. RECORD WARMTH IS EXPECTED THROUGH THE CHRISTMAS HOLIDAY
WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 355 AM WEDNESDAY...
...FLASH FLOOD WATCH CONTINUES ACROSS THE WESTERN PIEDMONT...
A SHORTWAVE TROUGH EMBEDDED WITHIN LARGER-SCALE TROUGH SITUATED
ACROSS MUCH OF THE CONUS WILL ADVANCE NEWD FROM THE SRN PLAINS
TOWARDS THE UPPER GREAT LAKES. ACCOMPANYING DEEPENING SFC LOW WILL
FOLLOW SUITE...TRACKING NEWD FROM THE MID-MO VALLEY TO THE UPPER MS
VALLEY BY LATE AFTERNOON. WHILE THESE FEATURES ARE A LITTLE WAYS
FROM HOME...DEEP SOUTHERLY FLOW ON THE EAST SIDE OF THE TROUGH WILL
ADVECT MODIFIED GULF AIR NORTHWARD INTO THE AREA...BRINGING
ANOMALOUS MOIST AND WARM AIR INTO THE AREA. PWATS ARE FORECAST TO
INCREASE TO 1.6-1.9"(4-5 STANDARD DEVIATIONS ABOVE NORMAL)...WHICH
WILL RIVAL MAX DECEMBER VALUES AT KGSO(1.65"-DATING BACK TO
1948)...WHILE TONIGHTS LOW TEMPERATURES WILL STRUGGLE TO DROP OUT OF
THE 70S AT MOST LOCATIONS...AGAIN HAVING A GOOD CHANCE OF MATCHING
THE ALL-TIME WARMEST DECEMBER MINIMUM TEMPERATURE ON RECORD(RDU-
69...FAY-69...GSO-65).
TWO MAIN CONCERNS ARE: 1)PERIODS OF MODERATE TO HEAVY RAINFALL THAT
MAY RESULT IN BOTH FLASHING FLOODING AS WELL AS MINOR FLOODING
ON AREAS RIVERS AND CREEKS AND 2)ISOLATED THREAT OF SEVERE STORMS
LATER TODAY.
FLOOD THREAT: LATEST RADAR TRENDS SHOW AN UPTICK IN CONVECTION
BREAKING OUT ACROSS THE AREA...FUELED BY A STRENGTHENING 50-60KT S-
SW LOW-LEVEL FLOW TO THE EAST OF THE AMPLIFYING SYSTEM TO OUR WEST.
MOST RECENT HRRR SIMULATIONS ARE HANDLING THE CONVECTION
BEST...DEPICTING THE HEAVIEST RAINFALL THIS MORNING ALONG AND EAST
OF HIGHWAY 1. THE AFOREMENTIONED HIGH MOISTURE ANOMALIES WILL
SUPPORT THE POTENTIAL FOR 1.5-2.0"/HOUR RAINFALL RATES OVER THESE
AREAS THIS MORNING THAT WOULD LIKELY CAUSE SOME LOCALIZED FLOODING
GIVEN SATURATED SOILS. HAVE ENTERTAINED THE IDEA OF EXPANDING THE
FLOOD WATCH TO INCLUDE COUNTIES ACROSS THE SANDHILLS AND CENTRAL
PIEDMONT...BUT AS PRECIP HAS BECOME MORE CONVECTIVE IN NATURE...ANY
SUCH HEAVY PRECIP WOULD BE FAIRLY LOCALIZED. WITH A SECOND ROUND OF
SHOWERS AND POSSIBLY A FEW STRONG TO SEVERE STORMS EXPECTED LATER
THIS AFTERNOON AS WARM SECTOR BECOMES ESTABLISHED OVER THE
AREA...AREAS IN THE WATCH COULD STILL SEE LOCALIZED HEAVY AMOUNTS OF
ONE TO TWO INCHES. AS SUCH... WILL KEEP THE FLASH FLOOD WATCH
CONFINED TO THE WESTERN PIEDMONT.
SEVERE THREAT: AS TEMPS CLIMB INTO THE LOWER TO MID 70S AND SFC
DEWPOINTS APPROACH UPPER 60S TO NEAR 70...MODELS SHOW 500-1000 J/KG
OF MUCAPE(HIGHEST IN THE EAST)DEVELOPING OVER THE AREA. 40-50KT DEEP
SHEAR AND SHERBE VALUES APPROACHING 1.0 COULD SUPPORT A FEW STRONG
TO SVR WIND GUSTS AND POSSIBLY AN ISOLATED TORNADO. WILL CONTINUE TO
ADVERTISE SEVERE POTENTIAL ACROSS THE EASTERN HALF OF THE FORECAST
AREA IN THE HWO.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 200 AM THURSDAY...
THU AND THU NIGHT: STILL SOME DIFFERENCES IN THE MODELS WITH RESPECT
TO RAIN...THUS THERE IS STILL SOME UNCERTAINTY. HOWEVER...IT IS
LOOKING LIKE THURSDAY COULD BE RELATIVELY DRY...BUT WILL KEEP A
CHANCE OF SOME RAIN IN THE FORECAST. RAIN SHOULD NOT BE NEARLY AS
WIDESPREAD AS IN PRECEDING DAYS. BEST CHANCES FOR CONVECTION WILL
BE IN THE NORTHWEST...ESPECIALLY IN THE AFT/EVE AND INTO THE
OVERNIGHT. HIGHEST TEMPERATURES OF THE LONG TERM ARE STILL EXPECTED
ON THURSDAY AS THE SOUTHERLY WARM ADVECTION PEAKS. HIGHS IN THE LOW
TO MID 70S NW TO AROUND 80 DEGREES IN THE SE. LOWS GENERALLY IN THE
MID 60S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 200 PM TUESDAY...
FRI THROUGH SUN: AS OF THE LATEST MEDIUM RANGE MODEL RUNS...THIS
PERIOD WILL LIKELY BE DOMINATED BY SUB-TROPICAL RIDGING ALOFT OVER
THE SOUTHEAST U.S.. SOUTHERLY TO SOUTHWESTERLY RETURN FLOW AROUND
THE SURFACE HIGH WILL CONTINUE TO USHER WARM MOIST AIR INTO THE
REGION...RESULTING IN A VERY WARM AND MOIST PERIOD FOR THIS TIME OF
YEAR. THE OCCASIONAL UPPER LEVEL DISTURBANCE RIDING THE RIDGE MAY
GENERATING ENOUGH LIFT IN THE ANOMALOUSLY WARM MOIST AIRMASS TO KICK
OFF SOME SHOWERS...MAINLY IN THE AFT/EVE HOURS. THE GENERAL PRECIP
TREND FOR THIS PERIOD WILL BE CHARACTERIZED BY A LULL DURING THE
OVERNIGHT AND MORNING HOURS AND HIGHEST CHANCES DURING THE AFT/EVE.
THE INITIAL FRONTAL SURGE THAT WAS ORIGINALLY EXPECTED TO PUSH SOUTH
INTO THE AREA ON FRIDAY WILL LIKELY STAY WELL TO THE NORTH THROUGH
AT LEAST SUNDAY EVENING. LOWS THROUGH THE PERIOD WILL BE FAIRLY
CONSISTENT...AND WELL ABOVE NORMAL...IN THE MID 50S TO LOW 60S.
HIGHS WILL LIKELY FLUCTUATE A BIT MORE...BUT GENERALLY STAY BETWEEN
THE MID 60S AND UPPER 70S...WHICH IS 10-15 DEGREES ABOVE NORMAL FOR
LATE DECEMBER.
MONDAY AND MONDAY NIGHT...THE GFS AND ECMWF VARY ON WHETHER THEY
THINK A SECONDARY SURGE WILL PUSH FAR ENOUGH SOUTH TO MOVE INTO
CENTRAL NC FOR THE BEGINNING OF THE WEEK. WILL HOLD OFF ON MAKING
ANY DRASTIC CHANGES TO THE PREVIOUS FORECAST FOR EARLY NEXT WEEK
UNTIL THERE IS BETTER AGREEMENT ONE WAY OR THE OTHER.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
AS OF 100 WEDNESDAY...
24 HOUR TAF PERIOD: WIDESPREAD ADVERSE AVIATION CONDITIONS WILL
PERSIST THROUGH THE 24 HOUR TAF PERIOD AS AN ANOMALOUSLY MOIST AND
WARM AIRMASS ADVECTS INTO THE AREA.
WIDESPREAD LIFR CIGS AND VSBYS IN DRIZZLE AND FOG HAVE OVERTAKEN THE
AREA. HOWEVER...WITH NEXT ROUND OF SHOWERS SPREADING NORTH INTO THE
AREA BETWEEN 06 TO 12Z...VSBYS SHOULD IMPROVE TO MVFR AND QUITE
POSSIBLY VFR. CEILINGS WILL BE MUCH SLOWER TO IMPROVE...REMAINING
LIFR ACROSS THE AREA THROUGH MID TO LATE MORNING...WITH SOME
TEMPORARY IMPROVEMENT TO MVFR OR VFR...PARTICULARLY AT KRDU/KFAY AND
KRWI THIS AFTERNOON AS WARM SECTOR OVERSPREADS THE AREA. SCATTERED
TO NUMEROUS SHOWERS AND POSSIBLY A FEW THUNDERSTORMS ARE EXPECTED
THROUGH THE AFTERNOON AND EVENING AS WE DESTABILIZE. SOUTHERLY WINDS
WILL INCREASE...GUSTING UP TO 20 TO 25 KTS.
CEILINGS COULD QUICKLY TO IFR TO LIFR ACROSS THE AREA THIS
EVENING...THOUGH A STEADY 10 TO 15KT SOUTHERLY BREEZE SHOULD
PRECLUDE WIDESPREAD FOG DEVELOPMENT.
OUTLOOK: A MOIST DEEP SOUTHWESTERLY FLOW DOWNSTREAM OF THE LONG WAVE
TROUGH IN PLACE ACROSS THE CENTRAL CONUS WILL SUPPORT A PROLONGED
PERIOD OF ADVERSE AVIATION CONDITIONS THROUGH MUCH OF THE PERIOD.
SUB-VFR CONDITIONS IN LOW CLOUDS/STRATUS WILL ALSO BE LIKELY EACH
MORNING... ALONG WITH THE TREAT OF SOME SHOWERS EACH DAY.
&&
.CLIMATE...
HERE ARE THE AREA RECORD MAXIMUMS AND HIGH MINIMUMS FOR DECEMBER 24TH
AND 25TH. RECORDS HAVE BEEN KEPT IN THE GREENSBORO AREA SINCE
1903... IN THE RALEIGH AREA SINCE 1887... AND IN THE FAYETTEVILLE
AREA SINCE 1910.
DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)
DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...CBL
SHORT TERM...22
LONG TERM...10
AVIATION...CBL
CLIMATE...HARTFIELD/BLAES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
932 PM CST THU DEC 24 2015
.UPDATE...
ISSUED AT 930 PM CST THU DEC 24 2015
MADE SOME SMALL CHANGES AND ADDED FLURRIES TO THE SOUTH CENTRAL
AND NORTH. ALSO THE SOUTHWEST HAS CLEARED AND THIS HAS ALLOWED
TEMPS TO FALL TO NEAR ZERO. LOWERED MINS SOUTHWEST TO AROUND 5
BELOW TONIGHT.
UPDATE ISSUED AT 735 PM CST THU DEC 24 2015
BAND OF SNOW ASSOCIATED WITH THE COLD FRONT REDUCING VISIBILITIES
AS LOW AS 1 3/4 MILES AT MINOT. WILL UPDATE FRO THIS SMALL AREA OF
SNOW ACROSS THE NORTH CENTRAL THIS EVENING. SHOULD TRACK INTO THE
DEVILS LAKE AREA AND DIMINISH TOWARDS MIDNIGHT.
UPDATE ISSUED AT 556 PM CST THU DEC 24 2015
AT 6 PM CST...A WEAK COLD FRONT WAS MOVING SOUTHEAST INTO
NORTHWEST NORTH DAKOTA A BIT FASTER THAN THE LATEST HRRR RUNS
SHOW. THE FRONT IS FORECAST TO REACH THE SOUTH CENTRAL BY
SUNRISE. FOR THE MOST PART SKIES WERE CLOUDY. CLEARING SKIES OVER
SOUTHWEST NORTH DAKOTA ARE FORECAST TO SPREAD EAST OVERNIGHT
LEAVING CLEAR SKIES OVER THE RELATIVELY FRESH SNOW COVER ACROSS THE
SOUTHERN HALF OF NORTH DAKOTA. SHORT RANGE MODELS CONTINUE TO
FAVOR FOG FORMATION OVER THE CLEARING SKIES OVERNIGHT. WILL
MAINTAIN THIS FORECAST TREND.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 254 PM CST THU DEC 24 2015
QUIET CHRISTMAS TRAVEL WEATHER ACROSS WESTERN AND CENTRAL NORTH
DAKOTA HIGHLIGHTS THE SHORT TERM FORECAST.
GIVEN GOOD AGREEMENT...UTILIZED A BLEND OF THE 12 UTC
DETERMINISTIC AND ENSEMBLE SUITES FOR NEARLY ALL FIELDS. THE VERY
PERSISTENT STRATUS DECK OVER THE PAST SEVERAL DAYS WILL CONTINUE
TO REMAIN ACROSS WESTERN AND CENTRAL NORTH DAKOTA TONIGHT INTO
CHRISTMAS DAY WITH NO EXCHANGE IN AIRMASS EXPECTED. THE 15-18 UTC
HRRR ITERATIONS AND 12 UTC NAM NEST WITHIN THEIR VISIBILITY
FORECASTS SUGGEST BUILD DOWN OF STRATUS INTO FOG ACROSS SOUTHWEST
AND SOUTH CENTRAL NORTH DAKOTA TONIGHT. WITH RATHER GOOD
RELIABILITY OF THIS SIGNAL IN THEIR SOLUTIONS OVER THE PAST
WEEK...HAVE ADDED FOG TO MUCH OF THE AREA TONIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 254 PM CST THU DEC 24 2015
COLD AND QUIET FOR MOST LOCATIONS FRIDAY NIGHT INTO SATURDAY. A
STRONG STORM SYSTEM WILL BRING SIGNIFICANT SNOWFALL AMOUNTS SOUTH
AND EAST OF THE REGION LATER ON FRIDAY THROUGH SATURDAY DAYTIME.
12Z MODELS HAVE COME BACK FARTHER NORTH WITH THE NORTHERN EXTENT
OF A SNOW SHIELD FRIDAY NIGHT AND SATURDAY...BUT STILL KEEPS
ADVISORY CRITERIA SNOWFALL SOUTH AND EAST OF THE SOUTHERN JAMES
RIVER VALLEY. THUS...WE ARE STILL NOT EXPECTING MUCH IMPACT FROM
THIS SYSTEM...BUT WILL HIGHLIGHT IMPACTS ELSEWHERE IN OUR SOCIAL
MEDIA WITH TRAVELERS IN NORTH DAKOTA POTENTIALLY TRAVELING TOWARDS
THE HIGHER SNOWFALL AMOUNTS. STRONG SURFACE HIGH PRESSURE BUILDS
INTO THE NORTHERN PLAINS IN THE WAKE OF THIS STORM
SYSTEM...BRINGING A COLD AIR SURGE WITH IT AND YIELDING
WIDESPREAD BELOW ZERO LOWS FOR SATURDAY NIGHT/SUNDAY MORNING AFTER
HIGHS ONLY IN THE SINGLE DIGITS ABOVE SATURDAY MOST AREAS.
UNCERTAINTY RAMPS UP AFTER THIS WEEKEND WITH A WIDE VARIETY OF
MODEL SOLUTIONS. OVERALL IT APPEARS WE SHOULD MODERATE SOME AS FAR
AS TEMPERATURES...AND MAY SEE ANOTHER CHANCE FOR SNOW MID-WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 556 PM CST THU DEC 24 2015
A WEAK COLD FRONT WILL MOVE SOUTHEAST ACROSS NORTH DAKOTA TONIGHT.
WIDESPREAD MVFR FROM KISN-KMOT-KBIS-KJMS WILL BECOME LOW MVFR TO
IFR OVERNIGHT. KDIK WILL BE VFR BECOMING IFR. WIDESPREAD FOG WILL
FORM OVER ALL OF NORTH DAKOTA WITH LOWEST VSBYS KDIK-KBIS-KJMS
AFTER 06Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...NH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
737 PM CST THU DEC 24 2015
.UPDATE...
ISSUED AT 735 PM CST THU DEC 24 2015
BAND OF SNOW ASSOCIATED WITH THE COLD FRONT REDUCING VISIBILITIES
AS LOW AS 1 3/4 MILES AT MINOT. WILL UPDATE FRO THIS SMALL AREA OF
SNOW ACROSS THE NORTH CENTRAL THIS EVENING. SHOULD TRACK INTO THE
DEVILS LAKE AREA AND DIMINISH TOWARDS MIDNIGHT.
UPDATE ISSUED AT 556 PM CST THU DEC 24 2015
AT 6 PM CST...A WEAK COLD FRONT WAS MOVING SOUTHEAST INTO
NORTHWEST NORTH DAKOTA A BIT FASTER THAN THE LATEST HRRR RUNS
SHOW. THE FRONT IS FORECAST TO REACH THE SOUTH CENTRAL BY
SUNRISE. FOR THE MOST PART SKIES WERE CLOUDY. CLEARING SKIES OVER
SOUTHWEST NORTH DAKOTA ARE FORECAST TO SPREAD EAST OVERNIGHT
LEAVING CLEAR SKIES OVER THE RELATIVELY FRESH SNOW COVER ACROSS THE
SOUTHERN HALF OF NORTH DAKOTA. SHORT RANGE MODELS CONTINUE TO
FAVOR FOG FORMATION OVER THE CLEARING SKIES OVERNIGHT. WILL
MAINTAIN THIS FORECAST TREND.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 254 PM CST THU DEC 24 2015
QUIET CHRISTMAS TRAVEL WEATHER ACROSS WESTERN AND CENTRAL NORTH
DAKOTA HIGHLIGHTS THE SHORT TERM FORECAST.
GIVEN GOOD AGREEMENT...UTILIZED A BLEND OF THE 12 UTC
DETERMINISTIC AND ENSEMBLE SUITES FOR NEARLY ALL FIELDS. THE VERY
PERSISTENT STRATUS DECK OVER THE PAST SEVERAL DAYS WILL CONTINUE
TO REMAIN ACROSS WESTERN AND CENTRAL NORTH DAKOTA TONIGHT INTO
CHRISTMAS DAY WITH NO EXCHANGE IN AIRMASS EXPECTED. THE 15-18 UTC
HRRR ITERATIONS AND 12 UTC NAM NEST WITHIN THEIR VISIBILITY
FORECASTS SUGGEST BUILD DOWN OF STRATUS INTO FOG ACROSS SOUTHWEST
AND SOUTH CENTRAL NORTH DAKOTA TONIGHT. WITH RATHER GOOD
RELIABILITY OF THIS SIGNAL IN THEIR SOLUTIONS OVER THE PAST
WEEK...HAVE ADDED FOG TO MUCH OF THE AREA TONIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 254 PM CST THU DEC 24 2015
COLD AND QUIET FOR MOST LOCATIONS FRIDAY NIGHT INTO SATURDAY. A
STRONG STORM SYSTEM WILL BRING SIGNIFICANT SNOWFALL AMOUNTS SOUTH
AND EAST OF THE REGION LATER ON FRIDAY THROUGH SATURDAY DAYTIME.
12Z MODELS HAVE COME BACK FARTHER NORTH WITH THE NORTHERN EXTENT
OF A SNOW SHIELD FRIDAY NIGHT AND SATURDAY...BUT STILL KEEPS
ADVISORY CRITERIA SNOWFALL SOUTH AND EAST OF THE SOUTHERN JAMES
RIVER VALLEY. THUS...WE ARE STILL NOT EXPECTING MUCH IMPACT FROM
THIS SYSTEM...BUT WILL HIGHLIGHT IMPACTS ELSEWHERE IN OUR SOCIAL
MEDIA WITH TRAVELERS IN NORTH DAKOTA POTENTIALLY TRAVELING TOWARDS
THE HIGHER SNOWFALL AMOUNTS. STRONG SURFACE HIGH PRESSURE BUILDS
INTO THE NORTHERN PLAINS IN THE WAKE OF THIS STORM
SYSTEM...BRINGING A COLD AIR SURGE WITH IT AND YIELDING
WIDESPREAD BELOW ZERO LOWS FOR SATURDAY NIGHT/SUNDAY MORNING AFTER
HIGHS ONLY IN THE SINGLE DIGITS ABOVE SATURDAY MOST AREAS.
UNCERTAINTY RAMPS UP AFTER THIS WEEKEND WITH A WIDE VARIETY OF
MODEL SOLUTIONS. OVERALL IT APPEARS WE SHOULD MODERATE SOME AS FAR
AS TEMPERATURES...AND MAY SEE ANOTHER CHANCE FOR SNOW MID-WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 556 PM CST THU DEC 24 2015
A WEAK COLD FRONT WILL MOVE SOUTHEAST ACROSS NORTH DAKOTA TONIGHT.
WIDESPREAD MVFR FROM KISN-KMOT-KBIS-KJMS WILL BECOME LOW MVFR TO
IFR OVERNIGHT. KDIK WILL BE VFR BECOMING IFR. WIDESPREAD FOG WILL
FORM OVER ALL OF NORTH DAKOTA WITH LOWEST VSBYS KDIK-KBIS-KJMS
AFTER 06Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...NH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
609 PM CST THU DEC 24 2015
.UPDATE...
ISSUED AT 556 PM CST THU DEC 24 2015
AT 6 PM CST...A WEAK COLD FRONT WAS MOVING SOUTHEAST INTO
NORTHWEST NORTH DAKOTA A BIT FASTER THAN THE LATEST HRRR RUNS
SHOW. THE FRONT IS FORECAST TO REACH THE SOUTH CENTRAL BY
SUNRISE. FOR THE MOST PART SKIES WERE CLOUDY. CLEARING SKIES OVER
SOUTHWEST NORTH DAKOTA ARE FORECAST TO SPREAD EAST OVERNIGHT
LEAVING CLEAR SKIES OVER THE RELATIVELY FRESH SNOW COVER ACROSS THE
SOUTHERN HALF OF NORTH DAKOTA. SHORT RANGE MODELS CONTINUE TO
FAVOR FOG FORMATION OVER THE CLEARING SKIES OVERNIGHT. WILL
MAINTAIN THIS FORECAST TREND.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 254 PM CST THU DEC 24 2015
QUIET CHRISTMAS TRAVEL WEATHER ACROSS WESTERN AND CENTRAL NORTH
DAKOTA HIGHLIGHTS THE SHORT TERM FORECAST.
GIVEN GOOD AGREEMENT...UTILIZED A BLEND OF THE 12 UTC
DETERMINISTIC AND ENSEMBLE SUITES FOR NEARLY ALL FIELDS. THE VERY
PERSISTENT STRATUS DECK OVER THE PAST SEVERAL DAYS WILL CONTINUE
TO REMAIN ACROSS WESTERN AND CENTRAL NORTH DAKOTA TONIGHT INTO
CHRISTMAS DAY WITH NO EXCHANGE IN AIRMASS EXPECTED. THE 15-18 UTC
HRRR ITERATIONS AND 12 UTC NAM NEST WITHIN THEIR VISIBILITY
FORECASTS SUGGEST BUILD DOWN OF STRATUS INTO FOG ACROSS SOUTHWEST
AND SOUTH CENTRAL NORTH DAKOTA TONIGHT. WITH RATHER GOOD
RELIABILITY OF THIS SIGNAL IN THEIR SOLUTIONS OVER THE PAST
WEEK...HAVE ADDED FOG TO MUCH OF THE AREA TONIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 254 PM CST THU DEC 24 2015
COLD AND QUIET FOR MOST LOCATIONS FRIDAY NIGHT INTO SATURDAY. A
STRONG STORM SYSTEM WILL BRING SIGNIFICANT SNOWFALL AMOUNTS SOUTH
AND EAST OF THE REGION LATER ON FRIDAY THROUGH SATURDAY DAYTIME.
12Z MODELS HAVE COME BACK FARTHER NORTH WITH THE NORTHERN EXTENT
OF A SNOW SHIELD FRIDAY NIGHT AND SATURDAY...BUT STILL KEEPS
ADVISORY CRITERIA SNOWFALL SOUTH AND EAST OF THE SOUTHERN JAMES
RIVER VALLEY. THUS...WE ARE STILL NOT EXPECTING MUCH IMPACT FROM
THIS SYSTEM...BUT WILL HIGHLIGHT IMPACTS ELSEWHERE IN OUR SOCIAL
MEDIA WITH TRAVELERS IN NORTH DAKOTA POTENTIALLY TRAVELING TOWARDS
THE HIGHER SNOWFALL AMOUNTS. STRONG SURFACE HIGH PRESSURE BUILDS
INTO THE NORTHERN PLAINS IN THE WAKE OF THIS STORM
SYSTEM...BRINGING A COLD AIR SURGE WITH IT AND YIELDING
WIDESPREAD BELOW ZERO LOWS FOR SATURDAY NIGHT/SUNDAY MORNING AFTER
HIGHS ONLY IN THE SINGLE DIGITS ABOVE SATURDAY MOST AREAS.
UNCERTAINTY RAMPS UP AFTER THIS WEEKEND WITH A WIDE VARIETY OF
MODEL SOLUTIONS. OVERALL IT APPEARS WE SHOULD MODERATE SOME AS FAR
AS TEMPERATURES...AND MAY SEE ANOTHER CHANCE FOR SNOW MID-WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 556 PM CST THU DEC 24 2015
A WEAK COLD FRONT WILL MOVE SOUTHEAST ACROSS NORTH DAKOTA TONIGHT.
WIDESPREAD MVFR FROM KISN-KMOT-KBIS-KJMS WILL BECOME LOW MVFR TO
IFR OVERNIGHT. KDIK WILL BE VFR BECOMING IFR. WIDESPREAD FOG WILL
FORM OVER ALL OF NORTH DAKOTA WITH LOWEST VSBYS KDIK-KBIS-KJMS
AFTER 06Z.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...NH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1227 AM CST WED DEC 23 2015
.UPDATE...
ISSUED AT 1227 AM CST WED DEC 23 2015
THE SURFACE LOW WAS NEAR GRAND FORKS...WITH MOSTLY LOW STRATUS
CLOUDS SURROUNDING THE LOW AND ACROSS MOST OF WESTERN AND CENTRAL
NORTH DAKOTA. LIGHT SNOW CONTINUED ACROSS MUCH OF THE NORTHERN TIER OF
COUNTIES...AND WESTWARD OVER EASTERN MONTANA. THIS IS ASSOCIATED
WITH THE DEFORMATION ZONE THAT EXTENDED SOUTHWESTWARD FROM NEAR
PEMBINA TO NEAR BEACH. SHORT TERM HIGH RES MODELS INDICATE LIGHT
SNOW CONTINUING ACROSS NORTHWEST AND NORTH CENTRAL NORTH DAKOTA FOR
THE REST OF THE EARLY MORNING HOURS...THEN TAPERING OFF LATER
WEDNESDAY MORNING. AS PER THE PREVIOUS UPDATE DISCUSSION...WILL
CONTINUE THE WINTER STORM WARNING FOR THE FAR NORTH CENTRAL. WILL
CONTINUE TO MONITOR THE TRENDS IN RADAR ECHO INTENSITY.
UPDATE ISSUED AT 934 PM CST TUE DEC 22 2015
...WILL CONTINUE THE WINTER STORM WARNING FAR NORTH CENTRAL...
SURFACE LOW PRESSURE OVER EAST CENTRAL NORTH DAKOTA WITH UPPER LOW
OVER SOUTHWEST MANITOBA. WARM SECTOR PRECIPITATION HAS PRETTY MUCH
LIFTED NORTH THROUGH NORTHERN MINNESOTA WITH MAINLY WRAP AROUND
MOISTURE CAUGHT IN THE DEFORMATION ZONE THAT STRETCHES BACK WEST
ACROSS NORTHERN NORTH DAKOTA AND INTO NORTHEAST MONTANA. LIGHT
SNOW STILL CONTINUING OVER NORTHERN PORTIONS OF PIERCE AND MCHENRY
COUNTY AND PRETTY MUCH MOST OF ROLETTE AND BOTTINEAU COUNTIES.
LATEST MESOSCALE MODELS CONTINUE TO INDICATE THIS AREA OF
PRECIPITATION REMAINING OVER THE WARNING AREA THROUGH AT LEAST 06
UTC AND THEN DISSIPATING...LIFTING NORTH THEREAFTER...WHILE WEAK
SHORTWAVE ENERGY PUSHES FROM NORTHEAST MONTANA INTO WESTERN NORTH
DAKOTA. HAVE UPDATE POPS TO KEEP CATEGORICAL POPS ACROSS THE
NORTH THROUGH 06 UTC...AND THEN SLOWLY TAPERING TO CHANCE POPS
AROUND 12Z. A DEEP DENDRITIC GROWTH LAYER REMAINS ACROSS NORTHERN
NORTH DAKOTA...AND OCCASIONAL BANDS OF HIGHER REFLECTIVITIES
CONTINUE TO DEVELOP ACROSS THE WARNING AREA. THEREFORE WILL
CONTINUE THE WARNING FOR NOW AND WILL TONE DOWN THE ADDITIONAL
SNOWFALL AMOUNTS. MANY AREAS WITHIN THE WARNING AREA HAD RECEIVED
4 TO 7 INCHES THROUGH LATE AFTERNOON...SO COULD SEE SOME MORE
REPORTS OF 6-8 INCHES WHEN MORNING REPORTS COME IN THURSDAY.
WARNING DOES EXPIRE AT 12 UTC BUT THE OVERNIGHT SHIFT CAN CANCEL
EARLY IF SNOW ENDS.
BACK IN NORTHWEST NORTH DAKOTA...LITTLE IF ANY SNOW FELL DURING
THE DAY WEDNESDAY...BUT WITH SNOW THIS EVENING...CONTINUING INTO
THURSDAY MORNING...WOULD EXPECT A FEW REPORTS OF 1-2 INCHES.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 253 PM CST TUE DEC 22 2015
HEAVY SNOW NORTH CENTRAL THROUGH EARLY THIS EVENING HIGHLIGHTS THE
SHORT TERM FORECAST.
AS OF 2130 UTC...A SECONDARY SHORTWAVE EVIDENT ON WATER VAPOR HAS
PROPAGATED NORTHEAST OUT OF NORTH CENTRAL SOUTH DAKOTA INTO SOUTH
CENTRAL NORTH DAKOTA...AS REFLECTED IN THE INTENSIFICATION OF
SNOWFALL ACROSS SOUTH CENTRAL NORTH DAKOTA OVER THE PAST ONE TO
TWO HOURS. THIS WAVE WILL CONTINUE TO PROPAGATE NORTHEAST AND
INTERACT WITH THE TROWAL ACROSS NORTH CENTRAL AND NORTHEAST NORTH
DAKOTA TO CONTINUE TO SUPPORT HEAVY SNOWFALL THROUGH EARLY THIS
EVENING. THE 17-20 UTC HRRR AND RAP ITERATIONS HAVE HANDLED THE
MESOSCALE BANDING OF SNOWFALL WELL THROUGH THE AFTERNOON AND WILL
FOLLOW THEIR SOLUTIONS THROUGH THE EVENING...BLENDED TO THE 12 UTC
GLOBAL SUITE LATE TONIGHT INTO WEDNESDAY MORNING. OVERALL...STORM
TOTAL SNOWFALL ACCUMULATIONS OF 6 TO 8 INCHES REMAIN UNCHANGED FOR
THE TOWNER...RUGBY...BOTTINEAU AND ROLETTE AREAS...WITH LOCALLY
HIGHER AMOUNTS. ELSEWHERE FOR TONIGHT INTO WEDNESDAY
MORNING...LIGHT SNOW IS EXPECTED. THIS IS IN ASSOCIATION WITH THE
WEAKENING TROWAL AND A WAVE CURRENTLY ACROSS NORTH CENTRAL
MONTANA THAT WILL PROPAGATE SOUTHEAST. ADDITIONAL SNOWFALL
ACCUMULATIONS OF AROUND ONE...TO POSSIBLY TWO INCHES ACROSS THE
WEST INTO THE SOUTH CENTRAL ARE FORECAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 253 PM CST TUE DEC 22 2015
COOLING TEMPERATURES INTO THE WEEKEND HIGHLIGHT THE EXTENDED
FORECAST.
THE 12 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN AGREEMENT ON
A BROAD...UPPER LEVEL WESTERN AND CENTRAL CONUS TROUGH TO BEGIN
THE PERIOD TO POSSIBLY TRANSITION TO SPLIT FLOW BY THE
WEEKEND...POTENTIALLY PLACING THE NORTHERN PLAINS IN NORTHWEST
FLOW ALOFT WITH THE NORTHERN STREAM. THIS SUPPORTS A POSSIBLE COOL
DOWN INTO THE WEEKEND. OVERALL...THE CHRISTMAS TRAVEL OUTLOOK
LOOKS GOOD WITH RATHER QUIET WEATHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1227 AM CST WED DEC 23 2015
MVFR TO OCCASIONAL IFR CONDITIONS ARE EXPECTED ACROSS WESTERN AND
CENTRAL NORTH DAKOTA THIS MORNING AND THROUGH MUCH OF THE DAY ON
WEDNESDAY. LIGHT WEST FLOW TONIGHT WILL TURN NORTH TO NORTHWEST
AND INCREASE TO UP TO 15 MPH ON WEDNESDAY AFTERNOON.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 AM CST EARLY THIS MORNING FOR
NDZ004-005-012-013.
&&
$$
UPDATE...JV
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...JV
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1040 PM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO
PENNSYLVANIA THROUGH THIS WEEKEND. TEMPERATURES WILL FALL BACK
TOWARD NORMAL NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
930 PM UPDATE...
STILLE NACHT. WIR HABEN NICHT WETTER. ALL IS CALM...ALL IS
BRIGHT - WITH THE FULL MOON GIVING A LUSTER OF MID-DAY TO OBJECTS
BELOW. WILL ADD IN THE MENTION OF A LITTLE VALLEY FOG TO ADD TO
THE SERN COS WHERE A MENTION WAS PREVIOUSLY MADE. THE REST OF THE
AREA HAS VERY DRY AIR AT THE SFC...BUT THE GOOD RADIATIONAL
COOLING IS ALLOWING TEMPS TO CHASE THE DEWPOINTS DOWNWARD.
OTHERWISE...ONLY MID/HIGH CLOUDS EXPECTED. JUST SOME MINOR TWEAKS
MADE TO TIMING/POPS IN SHORT TERM PD.
7 PM UPDATE...
HRR AND RAP STILL HINT AT A SHOWER OVER THE SERN COS IN THE MIDDLE
OF THE NIGHT. BUT ANYTHING SHOULD BE VERY LIGHT. WILL HOLD POPS
BELOW MENTIONABLE. HAVE ADDED SOME FOG TO THE WX GRIDS FOR THE SE
TONIGHT. TEMPS FALLING QUICKLY - BUT SO ARE DEWPOINTS. SO LIMITED
THE MENTION TO THE SE. BUT CAN EASILY SEE THE VALLEYS OF THE N/C
GETTING A LITTLE FOGGY.
PREV...
COLD FRONT AT 20Z OVER SE CORNER OF CWA...WITH JUST A CHANCE FOR A
SHOWER THERE THROUGH LATE EVENING. BULK OF PRECIP HAS SHIFTED WELL
TO THE SE AS LOW LEVEL JET EXITS THE REGION. CLEARING SKIES HAVE
DEVELOPED OVER WESTERN HALF OF PA...WILL SLIDE EASTWARD THIS
EVENING. UNSEASONABLY WARM /RECORD/ TEMPS REMAIN IN PLACE WITH
HIGHS AROUND 70F IN THE SE. NORTHERN AND WESTERN SECTIONS HAVE
LIKELY PEAKED AROUND 60F WITH WEAK CAA WORKING IN.
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD
PROVIDE FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T TOTALLY RULE OUT AN EVENING SHOWER ASSOC WITH
WEAK WAVE OF LOW PRES RIDING ALONG THE FRONTAL BNDRY THAT WILL
STALL JUST AS IT CLEARS CWA. LIKEWISE...A WEAK SHORTWAVE RIDING
ACROSS THE GRT LKS COULD SUPPORT AN ISOLD SHOWER TOWARD DAWN OVR
THE WESTERN MTNS.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA LOOKS
TO SPREAD A BIT OF LGT RAIN ACROSS GENERALLY THE SOUTHERN PART OF
THE STATE MAINLY DURING THE LATE MORNING AND AFTERNOON HOURS OF
CHRISTMAS DAY. MODELS IN GOOD AGREEMENT ON TIMING AND AMOUNTS.
GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN VERY WARM FOR
DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE L50S ACROSS THE
NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A DEEP TROUGH MOVING THROUGH THE CENTRAL UNITED STATES AND LARGE
HIGH PRESSURE AT THE SFC OVER THE EAST COAST WILL DOMINATE THE
WEATHER THROUGH THE WEEKEND. THE STALLED FRONTAL BOUNDARY WILL
CONTINUE TO LIFT NORTH SATURDAY INTO SUNDAY AS A DEEPENING TROUGH
MOVES DOWN THROUGH THE SOUTHWESTERN UNITED STATES. THE INTERACTION
OF THE TROUGH...ALONG WITH THE LARGE HIGH LOCATED OVER THE
ATLANTICWILL COME IN THE FORM OF A QUASI- STATIONARY BOUNDARY
THAT WILL BRING THE NEXT BEST CHANCE FOR PRECIPITATION THIS
WEEKEND.
ALL MID TO LONG RANGE MODELS HAVE THE TROUGH FORM A CUT OFF LOW.
THE BIG QUESTION IS LOCATION HOWEVER THE GEFS/GFS/EC ARE COMING
MORE INTO AGREEMENT ON POSITION AND STRENGTH. ALL OPERATIONAL
RUNS DIG THE LOW THROUGH NORTHERN MEXICO BEFORE TRAVERSING TEXAS
AND LIFTING INTO THE SOUTHERN GREAT LAKES AND THEN MOVING EASTWARD
OVER THE RIDGE. THOUGH THE PREDOMINATE LOCATION IS OVER TEXAS. THE
MODELS ARE COMING INTO A COMMON SOLUTION FOR THE MOVEMENT OF THE
MOIST BOUNDARY THAT SHOULD EXTEND FROM THE TROUGH/LOW THROUGH NEW
ENGLAND. ALL PWATS ARE ANOMALOUS IN THE +3 TO +4 RANGE SO EXPECT
FOR MORE PRECIPITATION SATURDAY THROUGH SUNDAY.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E LAKES
SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY SUNDAY.
COLD AIR DAMMING SCENARIO SATURDAY SHOULD RESULT IN A RELATIVE
COOL DAY /COMPARED TO THOSE RECENTLY/ WITH READINGS STUCK IN THE
40S OVR THE CENTRAL MTNS. WARMER CONDS EXPECTED SUNDAY...AS LOW
LVL COOL AIR IS SCOURED AHEAD OF COLD FRONT. GEFS 925 TEMPS AND EC
MOS SUGGEST TEMPS COULD APPROACH 70F ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS PERSIST FOR A BRIEF
PERIOD OF DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE
INDICATES N STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC
HIGH BUILDING SE FROM ONTARIO. NEXT CHC OF PRECIP COMES MON
NIGHT/TUESDAY...WHEN ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA
THRU THE GRT LKS. HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND
ASSOC SUPPLY OF CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS
FAVOR A WINTRY MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN
TUESDAY. HAVE ADJUSTED THE POPS AND THE PRECIP TYPE ACCORDINGLY.
&&
.AVIATION /04Z FRIDAY THROUGH TUESDAY/...
RADAR SHOWING A LOT OF ACTIVITY OVER THE NORTH POLE...THINK
SANTA IS HARD AT WORK.
03Z TAFS SENT. MOST SITES VFR.
HAVE UPDATED IPT SEVERAL TIMES...VFR TO IFR AT TIMES IN
FOG.
ALSO ADJUSTED LNS AND MDT FOR BKN040 CIGS.
EARLIER DISCUSSION BELOW.
FOR THE 00Z PACKAGE.
SOME HIGH CLDS ACROSS THE SE. OVERALL A NICE MILD LATE DEC
EVENING IN STORE FOR THE AREA.
UNLIKE TUE...SOME DROP IN DEWPOINT AND A LITTLE BREEZE
EARLIER...THUS NOT EXPECTING DENSE FOG TO FORM REAL FAST.
HOWEVER...HAVE SOME FOG IN LATER. EXPECT LOW TEMPERATURES
TO FALL BELOW CURRENT AND FCST DEWPTS...I.E. CROSSOVER
TEMPERATURES.
ALSO SOME LOWER CIGS IN SPOTS LIKE THE SE AND ALSO AT BFD
AND JST.
HAVING A HARD TIME TO SEE MUCH IN THE WAY OF RAIN ON
CHRISTMAS...NOT REALLY ANY LARGE LOW ON THE FRONT TO THE SOUTH.
FOR NOW...EXPECT A FEW FAST MOVING SHOWERS ACROSS THE SOUTH LATER
IN THE AFT.
OUTLOOK...
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
MON NIGHT-TUE...RESTRICTIONS LIKELY IN A POTENTIAL WINTRY MIX
TURNING TO PLAIN RAIN.
&&
.CLIMATE...
RECORD WARM AIRMASS IN PLACE.
SOME RECORDS SO FAR.
SO FAR TODAY...65 DEGREES AT WILLIAMSPORT. THIS READING WAS
SET AT 256 AM. THIS READING WAS REACHED AGAIN AT 237 PM. THE OLD
RECORD WAS 56 DEGREES SET IN 1931.
FOR WED...HARRISBURG REACHED 66 DEGREES. THIS BROKE THE RECORD
OF 64 DEGREES SET IN 1927.
HARRISBURG...68 DEGREES WAS RECORDED AT 911 AM. THIS BROKE THE
OLD RECORD OF 62 DEGREES SET IN 1990. HARRISBURG WARMED BACK
UP TO 70 DEGREES AT 105 PM.
ALTOONA REACHED 64 DEGREES AT 125 PM TODAY...BREAKING THE RECORD
OF 62 DEGREES SET IN 1955.
BRADFORD REACHED 59 DEGREES AT 140 AM TODAY...BREAKING THE RECORD
OF 55 DEGREES SET IN 1965.
EARLIER INFORMATION BELOW.
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RXR
NEAR TERM...DANGELO
SHORT TERM...RXR
LONG TERM...FITZGERALD/CERU
AVIATION...MARTIN
CLIMATE...HAGNER/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
941 PM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO
PENNSYLVANIA THROUGH THIS WEEKEND. TEMPERATURES WILL FALL BACK
TOWARD NORMAL NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
930 PM UPDATE...
STILLE NACHT. WIR HABEN NICHT WETTER. ALL IS CALM...ALL IS
BRIGHT - WITH THE FULL MOON GIVING A LUSTER OF MID-DAY TO OBJECTS
BELOW. WILL ADD IN THE MENTION OF A LITTLE VALLEY FOG TO ADD TO
THE SERN COS WHERE A MENTION WAS PREVIOUSLY MADE. THE REST OF THE
AREA HAS VERY DRY AIR AT THE SFC...BUT THE GOOD RADIATIONAL
COOLING IS ALLOWING TEMPS TO CHASE THE DEWPOINTS DOWNWARD.
OTHERWISE...ONLY MID/HIGH CLOUDS EXPECTED. JUST SOME MINOR TWEAKS
MADE TO TIMING/POPS IN SHORT TERM PD.
7 PM UPDATE...
HRR AND RAP STILL HINT AT A SHOWER OVER THE SERN COS IN THE MIDDLE
OF THE NIGHT. BUT ANYTHING SHOULD BE VERY LIGHT. WILL HOLD POPS
BELOW MENTIONABLE. HAVE ADDED SOME FOG TO THE WX GRIDS FOR THE SE
TONIGHT. TEMPS FALLING QUICKLY - BUT SO ARE DEWPOINTS. SO LIMITED
THE MENTION TO THE SE. BUT CAN EASILY SEE THE VALLEYS OF THE N/C
GETTING A LITTLE FOGGY.
PREV...
COLD FRONT AT 20Z OVER SE CORNER OF CWA...WITH JUST A CHANCE FOR A
SHOWER THERE THROUGH LATE EVENING. BULK OF PRECIP HAS SHIFTED WELL
TO THE SE AS LOW LEVEL JET EXITS THE REGION. CLEARING SKIES HAVE
DEVELOPED OVER WESTERN HALF OF PA...WILL SLIDE EASTWARD THIS
EVENING. UNSEASONABLY WARM /RECORD/ TEMPS REMAIN IN PLACE WITH
HIGHS AROUND 70F IN THE SE. NORTHERN AND WESTERN SECTIONS HAVE
LIKELY PEAKED AROUND 60F WITH WEAK CAA WORKING IN.
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD
PROVIDE FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T TOTALLY RULE OUT AN EVENING SHOWER ASSOC WITH
WEAK WAVE OF LOW PRES RIDING ALONG THE FRONTAL BNDRY THAT WILL
STALL JUST AS IT CLEARS CWA. LIKEWISE...A WEAK SHORTWAVE RIDING
ACROSS THE GRT LKS COULD SUPPORT AN ISOLD SHOWER TOWARD DAWN OVR
THE WESTERN MTNS.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA LOOKS
TO SPREAD A BIT OF LGT RAIN ACROSS GENERALLY THE SOUTHERN PART OF
THE STATE MAINLY DURING THE LATE MORNING AND AFTERNOON HOURS OF
CHRISTMAS DAY. MODELS IN GOOD AGREEMENT ON TIMING AND AMOUNTS.
GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN VERY WARM FOR
DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE L50S ACROSS THE
NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A DEEP TROUGH MOVING THROUGH THE CENTRAL UNITED STATES AND LARGE
HIGH PRESSURE AT THE SFC OVER THE EAST COAST WILL DOMINATE THE
WEATHER THROUGH THE WEEKEND. THE STALLED FRONTAL BOUNDARY WILL
CONTINUE TO LIFT NORTH SATURDAY INTO SUNDAY AS A DEEPENING TROUGH
MOVES DOWN THROUGH THE SOUTHWESTERN UNITED STATES. THE INTERACTION
OF THE TROUGH...ALONG WITH THE LARGE HIGH LOCATED OVER THE
ATLANTICWILL COME IN THE FORM OF A QUASI- STATIONARY BOUNDARY
THAT WILL BRING THE NEXT BEST CHANCE FOR PRECIPITATION THIS
WEEKEND.
ALL MID TO LONG RANGE MODELS HAVE THE TROUGH FORM A CUT OFF LOW.
THE BIG QUESTION IS LOCATION HOWEVER THE GEFS/GFS/EC ARE COMING
MORE INTO AGREEMENT ON POSITION AND STRENGTH. ALL OPERATIONAL
RUNS DIG THE LOW THROUGH NORTHERN MEXICO BEFORE TRAVERSING TEXAS
AND LIFTING INTO THE SOUTHERN GREAT LAKES AND THEN MOVING EASTWARD
OVER THE RIDGE. THOUGH THE PREDOMINATE LOCATION IS OVER TEXAS. THE
MODELS ARE COMING INTO A COMMON SOLUTION FOR THE MOVEMENT OF THE
MOIST BOUNDARY THAT SHOULD EXTEND FROM THE TROUGH/LOW THROUGH NEW
ENGLAND. ALL PWATS ARE ANOMALOUS IN THE +3 TO +4 RANGE SO EXPECT
FOR MORE PRECIPITATION SATURDAY THROUGH SUNDAY.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E LAKES
SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY SUNDAY.
COLD AIR DAMMING SCENARIO SATURDAY SHOULD RESULT IN A RELATIVE
COOL DAY /COMPARED TO THOSE RECENTLY/ WITH READINGS STUCK IN THE
40S OVR THE CENTRAL MTNS. WARMER CONDS EXPECTED SUNDAY...AS LOW
LVL COOL AIR IS SCOURED AHEAD OF COLD FRONT. GEFS 925 TEMPS AND EC
MOS SUGGEST TEMPS COULD APPROACH 70F ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS PERSIST FOR A BRIEF
PERIOD OF DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE
INDICATES N STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC
HIGH BUILDING SE FROM ONTARIO. NEXT CHC OF PRECIP COMES MON
NIGHT/TUESDAY...WHEN ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA
THRU THE GRT LKS. HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND
ASSOC SUPPLY OF CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS
FAVOR A WINTRY MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN
TUESDAY. HAVE ADJUSTED THE POPS AND THE PRECIP TYPE ACCORDINGLY.
&&
.AVIATION /03Z FRIDAY THROUGH TUESDAY/...
RADAR SHOWING A LOT OF ACTIVITY OVER THE NORTH POLE...THINK
SANTA IS HARD AT WORK.
FOR THE 00Z PACKAGE.
SOME HIGH CLDS ACROSS THE SE. OVERALL A NICE MILD LATE DEC
EVENING IN STORE FOR THE AREA.
UNLIKE TUE...SOME DROP IN DEWPOINT AND A LITTLE BREEZE
EARLIER...THUS NOT EXPECTING DENSE FOG TO FORM REAL FAST.
HOWEVER...HAVE SOME FOG IN LATER. EXPECT LOW TEMPERATURES
TO FALL BELOW CURRENT AND FCST DEWPTS...I.E. CROSSOVER
TEMPERATURES.
ALSO SOME LOWER CIGS IN SPOTS LIKE THE SE AND ALSO AT BFD
AND JST.
HAVING A HARD TIME TO SEE MUCH IN THE WAY OF RAIN ON
CHRISTMAS...NOT REALLY ANY LARGE LOW ON THE FRONT TO THE SOUTH.
FOR NOW...EXPECT A FEW FAST MOVING SHOWERS ACROSS THE SOUTH LATER
IN THE AFT.
OUTLOOK...
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
MON NIGHT-TUE...RESTRICTIONS LIKELY IN A POTENTIAL WINTRY MIX
TURNING TO PLAIN RAIN.
&&
.CLIMATE...
RECORD WARM AIRMASS IN PLACE.
SOME RECORDS SO FAR.
SO FAR TODAY...65 DEGREES AT WILLIAMSPORT. THIS READING WAS
SET AT 256 AM. THIS READING WAS REACHED AGAIN AT 237 PM. THE OLD
RECORD WAS 56 DEGREES SET IN 1931.
FOR WED...HARRISBURG REACHED 66 DEGREES. THIS BROKE THE RECORD
OF 64 DEGREES SET IN 1927.
HARRISBURG...68 DEGREES WAS RECORDED AT 911 AM. THIS BROKE THE
OLD RECORD OF 62 DEGREES SET IN 1990. HARRISBURG WARMED BACK
UP TO 70 DEGREES AT 105 PM.
ALTOONA REACHED 64 DEGREES AT 125 PM TODAY...BREAKING THE RECORD
OF 62 DEGREES SET IN 1955.
BRADFORD REACHED 59 DEGREES AT 140 AM TODAY...BREAKING THE RECORD
OF 55 DEGREES SET IN 1965.
EARLIER INFORMATION BELOW.
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RXR
NEAR TERM...DANGELO
SHORT TERM...RXR
LONG TERM...FITZGERALD/CERU
AVIATION...MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
716 PM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO
PENNSYLVANIA THROUGH THIS WEEKEND. TEMPERATURES WILL FALL BACK
TOWARD NORMAL NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
7 PM UPDATE...
HRR AND RAP STILL HINT AT A SHOWER OVER THE SERN COS IN THE MIDDLE
OF THE NIGHT. BUT ANYTHING SHOULD BE VERY LIGHT. WILL HOLD POPS
BELOW MENTIONABLE. HAVE ADDED SOME FOG TO THE WX GRIDS FOR THE SE
TONIGHT. TEMPS FALLING QUICKLY - BUT SO ARE DEWPOINTS. SO LIMITED
THE MENTION TO THE SE. BUT CAN EASILY SEE THE VALLEYS OF THE N/C
GETTING A LITTLE FOGGY.
PREV...
COLD FRONT AT 20Z OVER SE CORNER OF CWA...WITH JUST A CHANCE FOR A
SHOWER THERE THROUGH LATE EVENING. BULK OF PRECIP HAS SHIFTED WELL
TO THE SE AS LOW LEVEL JET EXITS THE REGION. CLEARING SKIES HAVE
DEVELOPED OVER WESTERN HALF OF PA...WILL SLIDE EASTWARD THIS
EVENING. UNSEASONABLY WARM /RECORD/ TEMPS REMAIN IN PLACE WITH
HIGHS AROUND 70F IN THE SE. NORTHERN AND WESTERN SECTIONS HAVE
LIKELY PEAKED AROUND 60F WITH WEAK CAA WORKING IN.
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD
PROVIDE FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T TOTALLY RULE OUT AN EVENING SHOWER ASSOC WITH
WEAK WAVE OF LOW PRES RIDING ALONG THE FRONTAL BNDRY THAT WILL
STALL JUST AS IT CLEARS CWA. LIKEWISE...A WEAK SHORTWAVE RIDING
ACROSS THE GRT LKS COULD SUPPORT AN ISOLD SHOWER TOWARD DAWN OVR
THE WESTERN MTNS.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA LOOKS
TO SPREAD A BIT OF LGT RAIN ACROSS GENERALLY THE SOUTHERN PART OF
THE STATE MAINLY DURING THE LATE MORNING AND AFTERNOON HOURS OF
CHRISTMAS DAY. MODELS IN GOOD AGREEMENT ON TIMING AND AMOUNTS.
GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN VERY WARM FOR
DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE L50S ACROSS THE
NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A DEEP TROUGH MOVING THROUGH THE CENTRAL UNITED STATES AND LARGE
HIGH PRESSURE AT THE SFC OVER THE EAST COAST WILL DOMINATE THE
WEATHER THROUGH THE WEEKEND. THE STALLED FRONTAL BOUNDARY WILL
CONTINUE TO LIFT NORTH SATURDAY INTO SUNDAY AS A DEEPENING TROUGH
MOVES DOWN THROUGH THE SOUTHWESTERN UNITED STATES. THE INTERACTION
OF THE TROUGH...ALONG WITH THE LARGE HIGH LOCATED OVER THE
ATLANTICWILL COME IN THE FORM OF A QUASI- STATIONARY BOUNDARY
THAT WILL BRING THE NEXT BEST CHANCE FOR PRECIPITATION THIS
WEEKEND.
ALL MID TO LONG RANGE MODELS HAVE THE TROUGH FORM A CUT OFF LOW.
THE BIG QUESTION IS LOCATION HOWEVER THE GEFS/GFS/EC ARE COMING
MORE INTO AGREEMENT ON POSITION AND STRENGTH. ALL OPERATIONAL
RUNS DIG THE LOW THROUGH NORTHERN MEXICO BEFORE TRAVERSING TEXAS
AND LIFTING INTO THE SOUTHERN GREAT LAKES AND THEN MOVING EASTWARD
OVER THE RIDGE. THOUGH THE PREDOMINATE LOCATION IS OVER TEXAS. THE
MODELS ARE COMING INTO A COMMON SOLUTION FOR THE MOVEMENT OF THE
MOIST BOUNDARY THAT SHOULD EXTEND FROM THE TROUGH/LOW THROUGH NEW
ENGLAND. ALL PWATS ARE ANOMALOUS IN THE +3 TO +4 RANGE SO EXPECT
FOR MORE PRECIPITATION SATURDAY THROUGH SUNDAY.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E LAKES
SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY SUNDAY.
COLD AIR DAMMING SCENARIO SATURDAY SHOULD RESULT IN A RELATIVE
COOL DAY /COMPARED TO THOSE RECENTLY/ WITH READINGS STUCK IN THE
40S OVR THE CENTRAL MTNS. WARMER CONDS EXPECTED SUNDAY...AS LOW
LVL COOL AIR IS SCOURED AHEAD OF COLD FRONT. GEFS 925 TEMPS AND EC
MOS SUGGEST TEMPS COULD APPROACH 70F ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS PERSIST FOR A BRIEF
PERIOD OF DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE
INDICATES N STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC
HIGH BUILDING SE FROM ONTARIO. NEXT CHC OF PRECIP COMES MON
NIGHT/TUESDAY...WHEN ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA
THRU THE GRT LKS. HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND
ASSOC SUPPLY OF CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS
FAVOR A WINTRY MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN
TUESDAY. HAVE ADJUSTED THE POPS AND THE PRECIP TYPE ACCORDINGLY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
RADAR SHOWING A LOT OF ACTIVITY OVER THE NORTH POLE...THINK
SANTA IS HARD AT WORK.
FOR THE 00Z PACKAGE.
SOME HIGH CLDS ACROSS THE SE. OVERALL A NICE MILD LATE DEC
EVENING IN STORE FOR THE AREA.
UNLIKE TUE...SOME DROP IN DEWPOINT AND A LITTLE BREEZE
EARLIER...THUS NOT EXPECTING DENSE FOG TO FORM REAL FAST.
HOWEVER...HAVE SOME FOG IN LATER. EXPECT LOW TEMPERATURES
TO FALL BELOW CURRENT AND FCST DEWPTS...I.E. CROSSOVER
TEMPERATURES.
ALSO SOME LOWER CIGS IN SPOTS LIKE THE SE AND ALSO AT BFD
AND JST.
HAVING A HARD TIME TO SEE MUCH IN THE WAY OF RAIN ON
CHRISTMAS...NOT REALLY ANY LARGE LOW ON THE FRONT TO THE SOUTH.
FOR NOW...EXPECT A FEW FAST MOVING SHOWERS ACROSS THE SOUTH LATER
IN THE AFT.
OUTLOOK...
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
MON NIGHT-TUE...RESTRICTIONS LIKELY IN A POTENTIAL WINTRY MIX
TURNING TO PLAIN RAIN.
&&
.CLIMATE...
RECORD WARM AIRMASS IN PLACE.
SOME RECORDS SO FAR.
SO FAR TODAY...65 DEGREES AT WILLIAMSPORT. THIS READING WAS
SET AT 256 AM. THIS READING WAS REACHED AGAIN AT 237 PM. THE OLD
RECORD WAS 56 DEGREES SET IN 1931.
FOR WED...HARRISBURG REACHED 66 DEGREES. THIS BROKE THE RECORD
OF 64 DEGREES SET IN 1927.
HARRISBURG...68 DEGREES WAS RECORDED AT 911 AM. THIS BROKE THE
OLD RECORD OF 62 DEGREES SET IN 1990. HARRISBURG WARMED BACK
UP TO 70 DEGREES AT 105 PM.
ALTOONA REACHED 64 DEGREES AT 125 PM TODAY...BREAKING THE RECORD
OF 62 DEGREES SET IN 1955.
BRADFORD REACHED 59 DEGREES AT 140 AM TODAY...BREAKING THE RECORD
OF 55 DEGREES SET IN 1965.
EARLIER INFORMATION BELOW.
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RXR
NEAR TERM...DANGELO
SHORT TERM...RXR
LONG TERM...FITZGERALD/CERU
AVIATION...MARTIN
CLIMATE...HAGNER/MARTIN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
656 PM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO
PENNSYLVANIA THROUGH THIS WEEKEND. TEMPERATURES WILL FALL BACK
TOWARD NORMAL NEXT WEEK.
&&
.NEAR TERM /UNTIL 7 AM FRIDAY MORNING/...
7 PM UPDATE...
HRR AND RAP STILL HINT AT A SHOWER OVER THE SERN COS IN THE MIDDLE
OF THE NIGHT. BUT ANYTHING SHOULD BE VERY LIGHT. WILL HOLD POPS
BELOW MENTIONABLE. HAVE ADDED SOME FOG TO THE WX GRIDS FOR THE SE
TONIGHT. TEMPS FALLING QUICKLY - BUT SO ARE DEWPOINTS. SO LIMITED
THE MENTION TO THE SE. BUT CAN EASILY SEE THE VALLEYS OF THE N/C
GETTING A LITTLE FOGGY.
PREV...
COLD FRONT AT 20Z OVER SE CORNER OF CWA...WITH JUST A CHANCE FOR A
SHOWER THERE THROUGH LATE EVENING. BULK OF PRECIP HAS SHIFTED WELL
TO THE SE AS LOW LEVEL JET EXITS THE REGION. CLEARING SKIES HAVE
DEVELOPED OVER WESTERN HALF OF PA...WILL SLIDE EASTWARD THIS
EVENING. UNSEASONABLY WARM /RECORD/ TEMPS REMAIN IN PLACE WITH
HIGHS AROUND 70F IN THE SE. NORTHERN AND WESTERN SECTIONS HAVE
LIKELY PEAKED AROUND 60F WITH WEAK CAA WORKING IN.
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD
PROVIDE FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T TOTALLY RULE OUT AN EVENING SHOWER ASSOC WITH
WEAK WAVE OF LOW PRES RIDING ALONG THE FRONTAL BNDRY THAT WILL
STALL JUST AS IT CLEARS CWA. LIKEWISE...A WEAK SHORTWAVE RIDING
ACROSS THE GRT LKS COULD SUPPORT AN ISOLD SHOWER TOWARD DAWN OVR
THE WESTERN MTNS.
&&
.SHORT TERM /7 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA LOOKS
TO SPREAD A BIT OF LGT RAIN ACROSS GENERALLY THE SOUTHERN PART OF
THE STATE MAINLY DURING THE LATE MORNING AND AFTERNOON HOURS OF
CHRISTMAS DAY. MODELS IN GOOD AGREEMENT ON TIMING AND AMOUNTS.
GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN VERY WARM FOR
DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE L50S ACROSS THE
NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A DEEP TROUGH MOVING THROUGH THE CENTRAL UNITED STATES AND LARGE
HIGH PRESSURE AT THE SFC OVER THE EAST COAST WILL DOMINATE THE
WEATHER THROUGH THE WEEKEND. THE STALLED FRONTAL BOUNDARY WILL
CONTINUE TO LIFT NORTH SATURDAY INTO SUNDAY AS A DEEPENING TROUGH
MOVES DOWN THROUGH THE SOUTHWESTERN UNITED STATES. THE INTERACTION
OF THE TROUGH...ALONG WITH THE LARGE HIGH LOCATED OVER THE
ATLANTICWILL COME IN THE FORM OF A QUASI- STATIONARY BOUNDARY
THAT WILL BRING THE NEXT BEST CHANCE FOR PRECIPITATION THIS
WEEKEND.
ALL MID TO LONG RANGE MODELS HAVE THE TROUGH FORM A CUT OFF LOW.
THE BIG QUESTION IS LOCATION HOWEVER THE GEFS/GFS/EC ARE COMING
MORE INTO AGREEMENT ON POSITION AND STRENGTH. ALL OPERATIONAL
RUNS DIG THE LOW THROUGH NORTHERN MEXICO BEFORE TRAVERSING TEXAS
AND LIFTING INTO THE SOUTHERN GREAT LAKES AND THEN MOVING EASTWARD
OVER THE RIDGE. THOUGH THE PREDOMINATE LOCATION IS OVER TEXAS. THE
MODELS ARE COMING INTO A COMMON SOLUTION FOR THE MOVEMENT OF THE
MOIST BOUNDARY THAT SHOULD EXTEND FROM THE TROUGH/LOW THROUGH NEW
ENGLAND. ALL PWATS ARE ANOMALOUS IN THE +3 TO +4 RANGE SO EXPECT
FOR MORE PRECIPITATION SATURDAY THROUGH SUNDAY.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E LAKES
SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY SUNDAY.
COLD AIR DAMMING SCENARIO SATURDAY SHOULD RESULT IN A RELATIVE
COOL DAY /COMPARED TO THOSE RECENTLY/ WITH READINGS STUCK IN THE
40S OVR THE CENTRAL MTNS. WARMER CONDS EXPECTED SUNDAY...AS LOW
LVL COOL AIR IS SCOURED AHEAD OF COLD FRONT. GEFS 925 TEMPS AND EC
MOS SUGGEST TEMPS COULD APPROACH 70F ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS PERSIST FOR A BRIEF
PERIOD OF DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE
INDICATES N STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC
HIGH BUILDING SE FROM ONTARIO. NEXT CHC OF PRECIP COMES MON
NIGHT/TUESDAY...WHEN ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA
THRU THE GRT LKS. HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND
ASSOC SUPPLY OF CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS
FAVOR A WINTRY MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN
TUESDAY. HAVE ADJUSTED THE POPS AND THE PRECIP TYPE ACCORDINGLY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
RADAR SHOWING A LOT OF ACTIVITY OVER THE NORTH POLE...THINK
SANTA IS HARD AT WORK.
FOR THE 00Z PACKAGE.
SOME HIGH CLDS ACROSS THE SE. OVERALL A NICE MILD LATE DEC
EVENING IN STORE FOR THE AREA.
UNLIKE TUE...SOME DROP IN DEWPOINT AND A LITTLE BREEZE
EARLIER...THUS NOT EXPECTING DENSE FOG TO FORM REAL FAST.
HOWEVER...HAVE SOME FOG IN LATER. EXPECT LOW TEMPERATURES
TO FALL BELOW CURRENT AND FCST DEWPTS...I.E. CROSSOVER
TEMPERATURES.
ALSO SOME LOWER CIGS IN SPOTS LIKE THE SE AND ALSO AT BFD
AND JST.
HAVING A HARD TIME TO SEE MUCH IN THE WAY OF RAIN ON
CHRISTMAS...NOT REALLY ANY LARGE LOW ON THE FRONT TO THE SOUTH.
FOR NOW...EXPECT A FEW FAST MOVING SHOWERS ACROSS THE SOUTH LATER
IN THE AFT.
OUTLOOK...
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
MON NIGHT-TUE...RESTRICTIONS LIKELY IN A POTENTIAL WINTRY MIX
TURNING TO PLAIN RAIN.
&&
.CLIMATE...
RECORD WARM AIRMASS IN PLACE.
SOME RECORDS SO FAR.
SO FAR TODAY...65 DEGREES AT WILLIAMSPORT. THIS READING WAS
SET AT 256 AM. THE OLD RECORD WAS 56 DEGREES SET IN 1931.
FOR WED...HARRISBURG REACHED 66 DEGREES. THIS BROKE THE RECORD
OF 64 DEGREES SET IN 1927.
SO FAR TODAY AT HARRISBURG...68 DEGREES WAS RECORDED AT 911 AM.
THIS BROKE THE OLD RECORD OF 62 DEGREES SET IN 1990.
UPDATED INFORMATION WILL BE SENT IN THE CLIMATE PRODUCT JUST
AFTER 5 PM FOR HARRISBURG AND WILLIAMSPORT.
EARLIER INFORMATION BELOW.
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RXR
NEAR TERM...DANGELO
SHORT TERM...RXR
LONG TERM...FITZGERALD/CERU
AVIATION...MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
708 PM EST THU DEC 24 2015
.SYNOPSIS...
DEEP MOISTURE WILL FOCUS MAINLY ON THE SOUTHERN APPALACHIANS TONIGHT
BEFORE GRADUALLY RETREATING TO THE NORTH AND WEST FRIDAY THROUGH THE
WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHEAST OVER THE
WEEKEND...BUT WITH CONTINUED LOW LEVEL MOISTURE IN PLACE. A STRONG
LOW PRESSURE SYSTEM MAY APPROACH FROM THE WEST EARLY NEXT WEEK TO
BRING ANOTHER ROUND OF HEAVY RAINFALL TO THE AREA.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 645 PM...PRECIP STREAMING ALONG THE FALL LINE WAS GRADUALLY
WEAKENING...PERHAPS AS IT GETS ROBBED OF MOISTURE FROM THE DEEPER
CONVECTION ON THE MORE UNSTABLE FLANK TO THE SOUTHEAST. HOWEVER...
LOW LEVEL UPSLOPE FLOW WAS FORCING THE REDEVELOPMENT OF SOME LIGHT
PRECIP NEAR THE SC BLUE RIDGE. THE MOST RECENT HRRR AND WRF-NMM
SUGGEST THAT CONVECTION OVER N CENTRAL GA WILL HOLD TOGETHER AND
INCREASE IN COVERAGE AS IT MOVES NE INTO THE WESTERN CAROLINAS THRU
06Z. THE FCST REFLECTS THIS THINKING WITH THE BETTER PRECIP
PROBABILITY SHIFTING TO THE MTNS FROM MID-EVENING ONWARD. THAT BEING
SAID...HAVE DROPPED THE PRECIP PROB A BIT BASED ON THE 18Z MODELS
WHICH SHOW LESS COVERAGE OVERNIGHT. TEMPS WILL REMAIN MILD.
DEEP LAYER SW FLOW WILL PERSIST THROUGH THE PERIOD AS WEAK H5 VORT
LOBES MOVE THROUGH ALOFT. THE BEST MOISTURE WILL FOCUS BACK
PRIMARILY ON THE SRN APPALACHIANS TONIGHT THROUGH FRIDAY AS HEIGHTS
SLOWLY BUILD ACROSS THE SE. THE LOW LEVEL FLOW WILL VEER FARTHER SW
AND FOCUS THE UPSLOPE FORCING AROUND THE FAR SRN AND SW MTNS.
INSTABILITY FOR SCT CONVECTION WILL REMAIN BEST IN PIEDMONT SECTIONS
ON FRIDAY...BUT WITH COVERAGE PROBABLY TOO LOW TO WARRANT A LONGER
DURATION WATCH EXPANSITION THERE. MINS WILL BE 30 DEGREES ABOVE
CLIMO TONIGHT WITH MAXES 20 DEGREES ABOVE CLIMO FRIDAY AFTN.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 230 PM EST THURSDAY...A PROMINENT SE RIDGE WILL FORM OVER THE
WEEKEND AS THE SRN STREAM SYSTEM APPROACHING W TX CREATES TREMENDOUS
HEIGHT FALLS WELL TO THE WEST. THE DEEPER MOISTURE WILL GET PUSHED N
AND WEST OF THE FORECAST AREA OVER THE WEEKEND. HOWEVER...LOW LEVEL
UPGLIDE WILL PERSIST OVER WRN SECTIONS AND PERMIT CONTINUED LOW END
SHOWER CHANCES. EXPECT WARM TEMPS AND INSTABILITY THROUGH THE
WEEKEND UNDER THE RIDGE...WITH ISOLD TSTMS POSSIBLE. MAXES WILL BE
IN THE 70S...WITH HIGHER ELEVATION 60S. MINS WILL BE IN THE 50S MTNS
AND 60S PIEDMONT WITH CONTINUED WARM CONDITIONS THROUGH SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM THURSDAY...THE MEDIUM RANGE BEGINS 00Z MONDAY WITH AN
ATLANTIC SURFACE RIDGE BREAKING DOWN AND AN UPPER LEVEL TROUGH AND
ASSOCIATED CLOSED LOW DEEPENING OVER THE SOUTHERN PLAINS. THE LOW
WILL TRANSLATE ACROSS THE MIDWEST MONDAY AND TUESDAY...BRINGING A
SURFACE COLD FRONT JUST TO THE WEST OF THE AREA.
MOIST SOUTH/SOUTHEASTERLY LOW LEVEL FLOW WILL PROVIDE PLENTIFUL
MOISTURE AS A SURFACE WARM FRONT DRAGS NORTH OF THE CWA MONDAY...AND
A SURFACE HIGH POSITIONED OVER THE NORTHEAST CONUS WILL ALLOW A
WEDGE TO BRIEFLY BUILD IN LATE MONDAY THROUGH THE DAY ON TUESDAY.
THE PRESENCE OF THE WEDGE COMBINED WITH THE MOIST SOUTHEASTERLY FLOW
WILL PROVIDE A WINDOW MONDAY NIGHT AND TUESDAY FOR SOME POTENTIAL
ISENTROPIC UPGLIDE...SO HAVE RAISED POPS TO LIKELY FOR MOST OF THE
AREA DURING THAT TIME. THE SURFACE COLD FRONT WILL PASS BY LATE
TUESDAY EVENING...SO POPS ARE TAPERED TO CHANCE TUESDAY NIGHT.
THE LULL IN POPS WILL BE BRIEF TUESDAY NIGHT...AS A FRONTAL BOUNDARY
OVER THE GULF WILL LIFT NORTHWARD TO APPROACH OUR AREA ON WEDNESDAY.
A MOIST TAP OF GULF AIR NEVER REALLY CUTS OFF AFTER THE PREVIOUS
FRONTAL PASSAGE...BUT A LACK OF IMPRESSIVE UPPER LIFT OR OTHER
FORCING WILL KEEP POPS JUST BELOW THE LIKELY CATEGORY. A SECOND
UPPER TROUGH/WEAK LOW WILL PASS WEDNESDAY NIGHT...WITH SOMEWHAT
DRIER AIR ALLOWED TO MOVE IN BEHIND THE FRONT THURSDAY AND FRIDAY.
POPS WILL FINALLY BE LOWERED SUBSTANTIALLY OVERNIGHT THURSDAY AND
INTO FRIDAY MORNING. THERE IS STILL DISAGREEMENT ON THE DEPTH OF THE
FINAL UPPER TROUGH THAT WILL PASS THURSDAY AND FRIDAY...BUT OVERALL
HEIGHT FALLS WILL LEAD TO A GRADUAL DECLINE IN TEMPERATURES TO JUST
5 TO 10 DEGREES ABOVE NORMAL BY FRIDAY.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AT KCLT...THE INITIAL PERIOD THRU MID EVENING SHOULD BE MVFR FOR
THE MOST PART...WITH SOME VFR HOLES ACROSS THE PIEDMONT. THE SHOWER
ACTIVITY SHOULD REMAIN S OF THE AIRFIELD THRU AT LEAST 02Z. AFTER
THAT TIME...MODEL GUIDANCE SUGGESTS THAT GREATER COVERAGE OF ECHOES
UPSTREAM ACROSS N GA WILL BEGIN TO IMPACT THE PIEDMONT. THIS SHOULD
BRING A MORE STEADY IFR CEILING IN FROM THE SW. FROM 06Z ONWARD...
THE GUIDANCE IS FAIRLY CERTAIN THAT CONDITIONS WILL DETERIORATE TO
IFR WITH EITHER CEILING AND/OR VIS...THEN LIFR TOWARD DAYBREAK. THIS
STANDS TO REASON WITH ALL THE LOW LEVEL MOISTURE AROUND. ONCE
ESTABLISHED...THE IFR CEILING WILL PERSIST THRU THE MORNING. HAVE
DEPARTED FROM GUIDANCE IN THAT LOW CLOUD BASE SHOULD BREAK
APART/LIFT TOWARD THE UPPER END OF MVFR DURING MIDDAY AS WE HAVE
SOME BOUNDARY LAYER HEATING.
ELSEWHERE...EXPECT SHRA/TSRA TO REDEVELOP FROM THE SW THRU THE LATE
EVENING. THIS SHOULD BRING A RETURN TO MVFR/IFR CEILING. THE
GUIDANCE LOOKS GRIM FOR FLYING CONDITIONS THRU AT LEAST DAYBREAK
WITH WIDESPREAD IFR/LIFR CEILING. CONDITIONS SHOULD SLOWLY IMPROVE
DURING THE MIDDLE PART OF THE DAY.
OUTLOOK...DEEP LAYER MOISTURE AHEAD OF A STALLED FRONT WILL PERSIST
OVER AT LEAST THE MOUNTAINS THROUGH LATE FRIDAY...BEFORE SOME MINOR
DRYING OCCURS OVER THE WEEKEND. SRLY UPSLOPE FLOW WILL PERSIST OVER
THE WEEKEND...HOWEVER...WITH SOME RESTRICTIONS ONCE AGAIN LIKELY.
ANOTHER WET SYSTEM WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
00-06Z 06-12Z 12-18Z 18-00Z
KCLT HIGH 81% MED 72% HIGH 92% HIGH 86%
KGSP HIGH 87% MED 78% HIGH 83% HIGH 97%
KAVL MED 78% HIGH 80% HIGH 84% HIGH 84%
KHKY LOW 54% MED 60% HIGH 88% LOW 52%
KGMU HIGH 84% HIGH 85% HIGH 87% HIGH 91%
KAND HIGH 85% MED 77% HIGH 93% HIGH 84%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.HYDROLOGY...
ONGOING AND DEVELOPING HYDRO ISSUES WILL BE EXACERBATED BY
ADDITIONAL MODERATE TO HEAVY RAINFALL IN THE EXTREME SOUTHERN
APPALCHIANS TONIGHT INTO FRIDAY. ADDITIONAL QPF OF 1.5 TO 2.5 INCHES
ARE POSSIBLE IN THE SRN ESCARPMENT AREAS...WITH 1 TO 2 INCHES
POSSIBLE ACROSS THE FOOTHILLS...AND AMOUNTS FALLING OFF QUICKLY
FARTHER EAST INTO THE PIEDMONT. LOCALLY HEAVY RAINFALL COULD
REDEVELOP JUST ABOUT ANYWHERE WITH SCATTERED CONVECTION...BUT THE NC
MOUNTAINS...GA MTNS...AND IMMEDIATELY ADJACENT FOOTHILLS SHOULD HAVE
THE LONGEST DURATION HYDRO ISSUES THROUGH FRIDAY. THE FLASH FLOOD
WATCH WILL BE EXTENDED IN THESE AREAS.
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR GAZ010-017-018-
026-028.
NC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR NCZ033-035-
048>053-058-059-062>065-501>510.
SC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR SCZ001>007-010.
&&
$$
SYNOPSIS...HG
NEAR TERM...HG/PM
SHORT TERM...HG
LONG TERM...LEV
AVIATION...PM
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
233 PM CST WED DEC 23 2015
.DISCUSSION...
MAIN LINE OF POTENTIALLY SEVERE TSTMS EXTENDS FROM MO BOOTHEEL
SOUTHWARD THROUGH EASTERN AR. SO FAR...SOME HALF INCH TO INCH HAIL
AND SOME WIND DAMAGE HAS OCCURRED ACROSS AR. OUT AHEAD OF THIS
LINE...SOME CONVECTIVE SHOWER DEVELOPMENT IS ONGOING. A FEW LTG
STRIKES HAVE JUST OCCURRED IN NW TN AND WESTERN KY. THIS INCREASE
IN DESTABILIZATION IS EXPECTED TO CONTINUE AS THE AFTERNOON WEARS
ON.
EARLIER THIS MORNING...SPC UPGRADED PART OF OUR AREA TO A MDT RISK.
SO...OVER ROUGHLY THE NW 2/3 OF THE MID STATE...WE HAVE A MDT RISK
IN EFFECT. TO OUR WEST...A TOR WATCH IS CURRENTLY IN EFFECT OVER
WESTERN TN UNTIL 8 PM. ADDITIONALLY...IT SHOULD BE NOTED THAT THE
WATCH IS A PDS...OR PARTICULARLY DANGEROUS SITUATION. HELICITY
VALUES ARE QUITE HIGH WITH THIS EVENT AND THESE HIGHER VALUES
CORRESPOND WELL WITH THE BEST FORCING AND INSTABILITY. THUS...ITS
JUST A MATTER OF TIME BEFORE THE WATCH IS EXTENDED EASTWARD TO
COVER THE MID STATE.
GOING FORWARD...I WILL INCLUDE CATEGORICAL POPS FOR TONIGHT AND
INCLUDE SVR WORDING WITH TORNADOS...DAMAGING WINDS AND LARGE HAIL
ALL BEING A VIABLE THREAT. THE TIMEFRAME STILL LOOKS LIKE THE 4PM
TO MIDNIGHT PERIOD. SOME RESIDUAL SHOWER AND NON SEVERE TSTM
ACTIVITY WILL PERSIST BEHIND THE SEVERE THREAT SO LOW POPS WILL
CONTINUE INTO THU MORNING.
BEHIND THIS SYSTEM...WE ARE STILL LOOKING AT A VERY MILD PATTERN.
THE SFC LOW LIFTS OFF WELL TO THE NORTH AND PREVENTS THE INTRUSION
OF ANY SEASONAL AIR.
ON FRIDAY...POPS WILL INCREASE AGAIN AS A WARM FRONT LIFTS
NORTHWARD. THE WARM FRONT WILL BE RATHER STRONG. IN FACT...AFTER A
HIGH ON FRIDAY IN THE MID 60S...LOW TEMPS WILL ONLY FALL TO THE
LOWER TO MID 60S. STILL CAN`T RULE OUT THE POTENTIAL FOR ONE OR TWO
STRONG STORMS WITH THE WARM FRONT BY FRI NT AS 850 MB FLOW WILL
REACH 30 KTS.
IN THE EXT FCST...STILL LOOKING AT A POWERFUL SYSTEM WHICH WILL
DEVELOP OVER TX ON SATURDAY. THIS FEATURE WILL LIFT OFF TO THE
NORTHEAST. EVENTUALLY...IT WILL DRAG A COLD FRONT THROUGH THE AREA
BY TUESDAY. THE SFC LOW CONFIGURATION DOES FEATURE SOME W-E
ELONGATION AND THUS...THE SEVERE THREAT WILL BE REDUCED. STILL
THOUGH...NEG SHOWALTER VALUES WILL ATTEMPT TO MOVE INTO THE MID
STATE ALONG WITH 50 KTS OF WIND AT THE 850 MB LEVEL. SO...CANNOT
RULE OUT STRONG STORMS ON MON AND MON NT.
TEMPS THOUGH THE EXTENDED WILL CONTINUE TO BE RATHER MILD AND COULD
SET RECORDS. RECORDS FOR THE DATE MAY BE SET ON FRIDAY AND FRIDAY NT
FOR BOTH MAX TEMPS AND MIN TEMPS. BEHIND THE FROPA...THE PREVAILING
AIRMASS LOOKS TO BE OF PACIFIC ORIGIN. FURTHERMORE...UPPER LEVEL
PATTERN GANGS ON TO THE DOMINANCE OF ELEVATED HEIGHT FIELDS. WE ARE
CERTAINLY ON OUR WAY TO THE 2ND WARMEST DECEMBER ON RECORD FOR
NASHVILLE.
&&
.AVIATION...
12Z TAF DISCUSSION.
MVFR/IFR CONDITIONS WILL PREVAIL THIS TAF PERIOD WITH NUMEROUS
SHOWERS AND THUNDERSTORMS TO AFFECT ALL AIRPORTS. BASED TIMING
HEAVILY ON THE HRRR MODEL...WITH ONE ROUND OF SHRA/TSRA ARRIVING
LATE WED MORN/EARLY AFT THEN MAIN ROUND OF SHRA/TSRA REACHING
TERMINALS BETWEEN 23-03Z. SOUTH WINDS UP TO 20 KTS WITH GUSTS TO
30 KTS TODAY AT AIRPORTS...ALTHOUGH GUSTY WINDS OVER 40KT POSSIBLE
IN ANY TSRA.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 57 73 56 66 65 / 90 20 30 70 70
CLARKSVILLE 50 70 50 67 63 / 90 20 30 70 70
CROSSVILLE 61 71 58 68 63 / 80 30 30 70 60
COLUMBIA 58 74 58 68 65 / 90 20 40 70 70
LAWRENCEBURG 59 73 58 69 65 / 90 30 40 70 60
WAVERLY 52 72 52 68 64 / 80 20 30 70 70
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........05
LONG TERM..................21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1138 AM CST WED DEC 23 2015
.DISCUSSION...
IMPULSE WORKING NORTHWARD ACROSS EASTERN AREAS OF THE MID STATE.
MODEL MRH FIELDS DO LEAN TOWARD BEING MORE BULLISH ACROSS EASTERN
AREAS THROUGH 00Z. WILL GO AHEAD AND INCREASE POPS EAST FOR THE
PERIOD 18Z THRU 22Z. OTW...MAIN LINE OF POTENTIALLY SEVERE TSTMS
IS NOW WORKING THROUGH EASTERN AR AND THE MO BOOTHEEL. THAT LINE
WILL BE HOLDING TOGETHER AS IT MOVES EASTWARD. DEVELOPMENT OUT
AHEAD OF THAT MAIN LINE IS STILL POSSIBLE. SAT TRENDS DO INDICATE
A FEW BREAKS IN THE CLOUDINESS ACROSS WESTERN TN AND NRN MS. THIS
WILL ACT TO ONLY DESTABILIZE CONDITIONS EVEN FURTHER.
NO OTHER CHANGES TO THE FCST AT THIS TIME...BUT AGAIN...WILL UP
POPS EAST.
&&
.AVIATION...
12Z TAF DISCUSSION.
MVFR/IFR CONDITIONS WILL PREVAIL THIS TAF PERIOD WITH NUMEROUS
SHOWERS AND THUNDERSTORMS TO AFFECT ALL AIRPORTS. BASED TIMING
HEAVILY ON THE HRRR MODEL...WITH ONE ROUND OF SHRA/TSRA ARRIVING
LATE WED MORN/EARLY AFT THEN MAIN ROUND OF SHRA/TSRA REACHING
TERMINALS BETWEEN 23-03Z. SOUTH WINDS UP TO 20 KTS WITH GUSTS TO
30 KTS TODAY AT AIRPORTS...ALTHOUGH GUSTY WINDS OVER 40KT POSSIBLE
IN ANY TSRA.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 74 60 73 56 70 / 70 90 30 40 70
CLARKSVILLE 72 54 71 51 65 / 70 90 20 30 70
CROSSVILLE 69 62 71 59 69 / 60 80 70 40 70
COLUMBIA 73 61 74 57 71 / 70 90 40 40 70
LAWRENCEBURG 72 62 73 58 72 / 70 90 50 50 70
WAVERLY 72 55 70 52 68 / 80 80 20 40 70
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........27/UNGER
LONG TERM..................21
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1046 AM CST WED DEC 23 2015
.DISCUSSION...
CURRENTLY...A LINE OF STRONG TO SEVERE THUNDERSTORMS EXTEND ACROSS
NE AR INTO CNTRL AR WHILE SCATTERED SHOWERS AND A FEW
THUNDERSTORMS ARE OCCURRING AHEAD OF THIS LINE. WITH INCREASING
INSTABILITY ACROSS NW TN...CONDITIONS REMAIN FAVORABLE FOR MORE
SEVERE THUNDERSTORMS AND POSSIBLE TORNADOES IN WATCH #558 OVER NE
AR...MO BOOTHEEL AND NW TN.
THIS AFTERNOON...EXPECT A SHORTWAVE TO EJECT OUT OF SRN AR INTO
THE MIDSOUTH INCREASING THE RISK FOR SEVERE WEATHER OVER MEMPHIS
AND JACKSON AND AREAS SOUTH OF I-40. PLENTY OF DYNAMICS AND
INSTABILITY WILL SUPPORT THE BEST CHANCE OF TORNADOES THIS
AFTERNOON FROM SUPERCELLS. LARGE HAIL AND DAMAGING WINDS WILL ALSO
HAVE A HIGHER THREAT.
THIS EVENING...THE UPPER SHORTWAVE MOVES TO THE NORTH AND 500MB
HTS RISE. THE RISK FOR SEVERE WEATHER WILL DECREASE AHEAD OF A WEAK
COLD FRONT AS THE MAIN DYNAMICS SHIFT TO THE NORTH.
SWC
&&
.PREV DISCUSSION... /ISSUED 522 AM CST WED DEC 23 2015/
.OUTBREAK OF SEVERE THUNDERSTORMS EXPECTED ACROSS THE MID SOUTH
ESPECIALLY THIS AFTERNOON AND TONIGHT...
DISCUSSION...10Z SURFACE ANALYSIS PLACES A STRONG SURFACE LOW
ACROSS SOUTH CENTRAL KANSAS AND A DRYLINE EXTENDING SOUTH FROM
THE LOW ACROSS WESTERN OKLAHOMA AND WESTERN TEXAS. SOUTHERLY WINDS
IN ADVANCE OF THIS SURFACE LOW HAVE ALREADY ADVECTED LOWER TO
MIDDLE 60 DEWPOINT AIR UP INTO THE LOWER MISSISSIPPI VALLEY THIS
MORNING. WATER VAPOR SATELLITE TRENDS INDICATE A DEEP LONGWAVE
UPPER LEVEL TROUGH OVER THE CENTRAL AND SOUTHERN PLAINS AND A LEAD
SHORTWAVE TROUGH OVER THE LOWER MISSISSIPPI VALLEY. AT THE SURFACE A
WARM FRONT IS MOVING ACROSS THE MID SOUTH AS OF DISCUSSION.
CONSEQUENTLY...SHOWERS AND THUNDERSTORMS HAVE EXPANDED IN COVERAGE
ACROSS ARKANSAS OVERNIGHT. AS OF 4 AM CST...TEMPERATURES ACROSS
THE MID SOUTH ARE IN THE 60S AT MOST LOCATIONS. SEVERE
THUNDERSTORM POTENTIAL THIS AFTERNOON AND TONIGHT IS THE
PREDOMINANT FOCUS IN THIS MORNING/S FORECAST ISSUANCE.
SHOWERS AND THUNDERSTORMS OVER ARKANSAS AND SOUTHERN MISSISSIPPI
WILL SPREAD ACROSS THE MID SOUTH THIS MORNING. A STRONG TO SEVERE
THUNDERSTORM IS POSSIBLE THIS MORNING BUT THINK THE BULK OF THE
SEVERE THUNDERSTORM THREAT WILL OCCUR MAINLY THIS AFTERNOON AND
TONIGHT AS A NEGATIVELY TILTED UPPER LEVEL TROUGH AND A STRONG
COLD FRONT ROTATE THROUGH THE MIDDLE AND LOWER MISSISSIPPI
VALLEYS.
RECORD WARMTH WITH HIGHS TODAY IN THE LOWER TO MIDDLE 70S COMBINED
WITH FAVORABLE UPPER LEVEL DIVERGENCE PRODUCED BY THE RIGHT EXIT
REGION OF A 130 KT UPPER LEVEL JET...DECENT 50-80 DM 500 MB MID
LEVEL HEIGHT FALLS...SURFACE BASED CAPE VALUES BETWEEN 1500-2O00
J/KG...STEEP 700-500 MB LAYER MID LEVEL LAPSE RATES AROUND 7
C/KM...0-1 KM STORM RELATIVE HELICITIES AROUND 300
M2/S2...STRONGLY CURVED HODOGRAPHS...FAVORABLE LCL/S AND 0-6 KM
BULK SHEAR VALUES IN EXCESS OF 70 KTS SUGGESTS A VERY GOOD
POTENTIAL FOR THUNDERSTORMS TO BECOME SEVERE ACROSS THE MID SOUTH
ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS. LARGE
HAIL...DAMAGING WINDS...AND TORNADOES ARE ALL POSSIBLE WITH ANY
THUNDERSTORMS THAT REACH SEVERE LIMITS. A POTENTIAL ALSO EXISTS
FOR SIGNIFICANT TORNADOES ACROSS MUCH OF THE MID SOUTH WITH THE
I-40 CORRIDOR IN THE CENTER OF THE RISK AREA. SHORT TERM MESOSCALE
TRENDS WILL CLOSELY BE MONITORED THROUGHOUT THE DAY IN CASE ANY
ADJUSTMENTS ARE NEEDED TO THE CURRENT FORECAST AND HAZARDOUS
WEATHER OUTLOOK. RESIDENTS OF THE MID-SOUTH AND HOLIDAY TRAVELERS
SHOULD STAY TUNED TO THE FORECAST TODAY AND BE PREPARED TO TAKE
APPROPRIATE SAFETY PRECAUTIONS IF SEVERE WEATHER THREATENS THEIR
LOCATION.
THE SEVERE THUNDERSTORM THREAT SHOULD BEGIN TO PUSH EAST OF THE
MID SOUTH TONIGHT AS A STRONG COLD FRONT SWEEPS THROUGH THE
AREA...BRINGING AN GRADUAL END TO SHOWER AND THUNDERSTORM CHANCES
BY CHRISTMAS EVE. HOWEVER...THIS IS NOT EXPECTED TO LAST LONG AS
THIS FRONT WILL STALL OUT AND RETURN BACK NORTH AS A WARM FRONT
CHRISTMAS EVE NIGHT INTO CHRISTMAS DAY. ANOTHER CHANCE FOR STRONG
TO SEVERE THUNDERSTORMS WILL BE POSSIBLE DURING THIS AND WILL BE
CLOSELY WATCHED IN UPCOMING FORECASTS.
LONG TERM MODELS INDICATE THE MID SOUTH WILL REMAIN IN A WARM
SECTOR FOR THE UPCOMING WEEKEND RESULTING IN A CONTINUED CHANCE
FOR SHOWERS AND THUNDERSTORMS. AN UPPER LEVEL LOW IS EXPECTED TO
DEVELOP AND MOVE FROM THE SOUTHERN PLAINS INTO THE MIDDLE/LOWER
MISSISSIPPI VALLEYS BY EARLY NEXT WEEK. THIS MAY POSE YET ANOTHER
POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS BETWEEN SUNDAY NIGHT
TO MONDAY NIGHT. CONFIDENCE IS LOW AT THIS MOMENT DUE TO
PERSISTENT RUN TO RUN CONTINUITY ISSUES WITH THIS PARTICULAR
SYNOPTIC SYSTEM. STAY TUNED...
CJC
&&
.AVIATION...
AVIATION...
12Z TAFS
DEEP SUBTROPICAL MOISTURE WILL PREVAIL TODAY...WITH STRONG
VERTICAL WIND SHEER SUPPORTIVE OF A DEVELOPING LINE OF INTENSE
SURFACE-TSRA AFTER 18Z. HRRR AND NAM INDICATED A BROKEN LINE OF
TSRA. FOR THIS MORNING...SHRA/TSRA WILL BE ROOTED IN AN ELEVATED
LAYER ABOVE THE MOIST LOW LEVEL INVERSION.
PROSPECTS FOR A MVFR/VFR LATE EVENING MEM ARRIVAL PUSH APPEAR
PROMISING...ASSUMING POST FRONTAL STRATUS DEPICTED ON THE 06Z NAM
BUFR SOUNDINGS DOES NOT MATERIALIZE.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
945 AM CST WED DEC 23 2015
.DISCUSSION...
QUIET FOR NOW...BUT THAT WILL BE CHANGING LATER TODAY.
CURRENTLY...JUST A FEW SCATTERED SHOWERS ACROSS OUR WESTERN AREAS.
MODELS DO ELUDE TOWARD AN ENHANCEMENT IN LIFT AS SOME PVA STARTS
TO ENCROACH ON OUR FAR WESTERN COUNTIES BY 18Z. THUS...AS
INSTABILITIES INCREASE...WE COULD SEE A FEW STRONG STORMS BEGIN TO
DEVELOP WEST OF I-65 AS WE MOVE INTO THE EARLY AFTERNOON. FOR NOW
THOUGH...FOR THE PD PRIOR TO 18Z...WILL GO AHEAD AND LOWER POPS
ACROSS NORTHEASTERN AND EAST CENTRAL AREAS TO JUST A SLIGHT
CHANCE. REMAINDER OF FCST IS IN GOOD SHAPE. THE CONVECTIVE
ACTIVITY...THAT WILL BRING THE SEVERE WEATHER TO OUR AREA THIS
AFTERNOON AND EVENING...IS LOCATED ACROSS CENTRAL AR AT THIS TIME.
A FEW REPORTS OF TSTM WIND DAMAGE HAVE BEEN REPORTED IN ARKANSAS
THIS MORNING.
UPDATE OUT SHORTLY.
&&
.AVIATION...
12Z TAF DISCUSSION.
MVFR/IFR CONDITIONS WILL PREVAIL THIS TAF PERIOD WITH NUMEROUS
SHOWERS AND THUNDERSTORMS TO AFFECT ALL AIRPORTS. BASED TIMING
HEAVILY ON THE HRRR MODEL...WITH ONE ROUND OF SHRA/TSRA ARRIVING
LATE WED MORN/EARLY AFT THEN MAIN ROUND OF SHRA/TSRA REACHING
TERMINALS BETWEEN 23-03Z. SOUTH WINDS UP TO 20 KTS WITH GUSTS TO
30 KTS TODAY AT AIRPORTS...ALTHOUGH GUSTY WINDS OVER 40KT POSSIBLE
IN ANY TSRA.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 74 60 73 56 70 / 70 90 30 40 70
CLARKSVILLE 72 54 71 51 65 / 70 90 20 30 70
CROSSVILLE 69 62 71 59 69 / 50 80 70 40 70
COLUMBIA 73 61 74 57 71 / 70 90 40 40 70
LAWRENCEBURG 72 62 73 58 72 / 70 90 50 50 70
WAVERLY 72 55 70 52 68 / 80 80 20 40 70
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........27/UNGER
LONG TERM..................21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
618 AM CST WED DEC 23 2015
.UPDATE...
FOR 12Z AVIATION DISCUSSION.
&&
.DISCUSSION...
...SEVERE STORMS WITH TORNADOES POSSIBLE IN THE MID STATE THIS
AFTERNOON AND EVENING...
...SREF HAS SIGNIFICANT TORNADO PARAMETER AT 5 FOR MID STATE THIS
AFTERNOON AND EVENING...
...THE LAST TIME A TORNADO OCCURRED IN THE MONTH OF DECEMBER IN
TENNESSEE WAS BACK IN 2000 IN LINCOLN COUNTY...AND BEFORE THAT IN
1988 IN WILLIAMSON COUNTY...DECEMBER TORNADOES ARE SOMEWHAT
RARE...
FOR DISCUSSION PURPOSES WILL CONCENTRATE ON TODAY AND TONIGHT.
MADE ONLY MINOR TWEAKS TO THE EXTENDED. LONG WAVE TROUGH ACROSS
CENTRAL U.S. WILL AMPLIFY AS STRONG HEIGHT FALL CENTER IN EXCESS
OF 90 METERS PUSHES ACROSS NORTH TEXAS DURING THE DAY. UPPER
TROUGH WILL TAKE ON NEGATIVE TILT AS IT WORKS INTO OUR AREA THIS
AFTERNOON AND EVENING AS EMBEDDED SHORT WAVE SWINGS THIS WAY.
STRONG MOISTURE TRANSPORT WILL GET UNDERWAY DURING THE DAY FROM
GULF REGION DRIVING PRECIPITABLE WATER WELL ABOVE CLIIMATOLOGY FOR
THIS TIME OF THE YEAR. 60 DEGREE DEWPOINTS ALREADY IN PLACE WITH
CURRENT TEMPS IN THE LOW 60`S. 986 MBAR SURFACE LOW CENTER
CURRENTLY OVER WESTERN PANHANDLE OF OKLAHOMA...WARM FRONT DRAPED
FROM LOW CENTER ACROSS NORTHERN MISSOURI...SOUTHERN ILLINOIS THEN
UP INTO SOUTHERN INDIANA AND NORTHERN OHIO. MID STATE WILL BE IN
WARM SECTOR FOR THIS SEVERE WEATHER EVENT WITH MUCAPES ON THE
ORDER OF 500 TO 750 JOULES PER KILOGRAM AT 00Z TODAY. LIFTED
INDICES GO TO -4 THIS AFTERNOON/EVENING AS 850 MBAR JET CLIMBS TO
50-70 KNOTS AT 00Z. AS IF THIS IS NOT ENOUGH THE 700 MBAR TO 500
MBAR LAPSE RATES OFF 00Z OHX SOUNDING AT 7.7 DEGS CELSIUS PER
KILOMETER.
.CLIMATE...CHRISTMAS 1964...A TORNADO CUT A MILLION DOLLAR DAMAGE
PATH FROM WHISPERING HILLS SECTION OF NASHVILLE TO NEAR UNA...AT
11:50 PM CST CHRISTMAS NIGHT.
YEAR AND NUMBER OF TENNESSEE TORNADOES IN THE MONTH OF DECEMBER
SINCE 1950...
2000...1
1988...1 ONLY DECEMBER TORNADO FATALITY SINCE 1950
1987...1
1982...1
1978...2
1977...3
1973...2
1971...1
1967...3
1964...1
1957...3
&&
.AVIATION...
12Z TAF DISCUSSION.
MVFR/IFR CONDITIONS WILL PREVAIL THIS TAF PERIOD WITH NUMEROUS
SHOWERS AND THUNDERSTORMS TO AFFECT ALL AIRPORTS. BASED TIMING
HEAVILY ON THE HRRR MODEL...WITH ONE ROUND OF SHRA/TSRA ARRIVING
LATE WED MORN/EARLY AFT THEN MAIN ROUND OF SHRA/TSRA REACHING
TERMINALS BETWEEN 23-03Z. SOUTH WINDS UP TO 20 KTS WITH GUSTS TO
30 KTS TODAY AT AIRPORTS...ALTHOUGH GUSTY WINDS OVER 40KT POSSIBLE
IN ANY TSRA.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........55/SHAMBURGER
LONG TERM..................01/BOYD
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
550 AM CST WED DEC 23 2015
.UPDATE...
UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
&&
.PREV DISCUSSION... /ISSUED 522 AM CST WED DEC 23 2015/
..OUTBREAK OF SEVERE THUNDERSTORMS EXPECTED ACROSS THE MID SOUTH
ESPECIALLY THIS AFTERNOON AND TONIGHT...
DISCUSSION...10Z SURFACE ANALYSIS PLACES A STRONG SURFACE LOW
ACROSS SOUTH CENTRAL KANSAS AND A DRYLINE EXTENDING SOUTH FROM
THE LOW ACROSS WESTERN OKLAHOMA AND WESTERN TEXAS. SOUTHERLY WINDS
IN ADVANCE OF THIS SURFACE LOW HAVE ALREADY ADVECTED LOWER TO
MIDDLE 60 DEWPOINT AIR UP INTO THE LOWER MISSISSIPPI VALLEY THIS
MORNING. WATER VAPOR SATELLITE TRENDS INDICATE A DEEP LONGWAVE
UPPER LEVEL TROUGH OVER THE CENTRAL AND SOUTHERN PLAINS AND A LEAD
SHORTWAVE TROUGH OVER THE LOWER MISSISSIPPI VALLEY. AT THE SURFACE A
WARM FRONT IS MOVING ACROSS THE MID SOUTH AS OF DISCUSSION.
CONSEQUENTLY...SHOWERS AND THUNDERSTORMS HAVE EXPANDED IN COVERAGE
ACROSS ARKANSAS OVERNIGHT. AS OF 4 AM CST...TEMPERATURES ACROSS
THE MID SOUTH ARE IN THE 60S AT MOST LOCATIONS. SEVERE
THUNDERSTORM POTENTIAL THIS AFTERNOON AND TONIGHT IS THE
PREDOMINANT FOCUS IN THIS MORNING/S FORECAST ISSUANCE.
SHOWERS AND THUNDERSTORMS OVER ARKANSAS AND SOUTHERN MISSISSIPPI
WILL SPREAD ACROSS THE MID SOUTH THIS MORNING. A STRONG TO SEVERE
THUNDERSTORM IS POSSIBLE THIS MORNING BUT THINK THE BULK OF THE
SEVERE THUNDERSTORM THREAT WILL OCCUR MAINLY THIS AFTERNOON AND
TONIGHT AS A NEGATIVELY TILTED UPPER LEVEL TROUGH AND A STRONG
COLD FRONT ROTATE THROUGH THE MIDDLE AND LOWER MISSISSIPPI
VALLEYS.
RECORD WARMTH WITH HIGHS TODAY IN THE LOWER TO MIDDLE 70S COMBINED
WITH FAVORABLE UPPER LEVEL DIVERGENCE PRODUCED BY THE RIGHT EXIT
REGION OF A 130 KT UPPER LEVEL JET...DECENT 50-80 DM 500 MB MID
LEVEL HEIGHT FALLS...SURFACE BASED CAPE VALUES BETWEEN 1500-2O00
J/KG...STEEP 700-500 MB LAYER MID LEVEL LAPSE RATES AROUND 7
C/KM...0-1 KM STORM RELATIVE HELICITIES AROUND 300
M2/S2...STRONGLY CURVED HODOGRAPHS...FAVORABLE LCL/S AND 0-6 KM
BULK SHEAR VALUES IN EXCESS OF 70 KTS SUGGESTS A VERY GOOD
POTENTIAL FOR THUNDERSTORMS TO BECOME SEVERE ACROSS THE MID SOUTH
ESPECIALLY DURING THE AFTERNOON AND EVENING HOURS. LARGE
HAIL...DAMAGING WINDS...AND TORNADOES ARE ALL POSSIBLE WITH ANY
THUNDERSTORMS THAT REACH SEVERE LIMITS. A POTENTIAL ALSO EXISTS
FOR SIGNIFICANT TORNADOES ACROSS MUCH OF THE MID SOUTH WITH THE
I-40 CORRIDOR IN THE CENTER OF THE RISK AREA. SHORT TERM MESOSCALE
TRENDS WILL CLOSELY BE MONITORED THROUGHOUT THE DAY IN CASE ANY
ADJUSTMENTS ARE NEEDED TO THE CURRENT FORECAST AND HAZARDOUS
WEATHER OUTLOOK. RESIDENTS OF THE MID-SOUTH AND HOLIDAY TRAVELERS
SHOULD STAY TUNED TO THE FORECAST TODAY AND BE PREPARED TO TAKE
APPROPRIATE SAFETY PRECAUTIONS IF SEVERE WEATHER THREATENS THEIR
LOCATION.
THE SEVERE THUNDERSTORM THREAT SHOULD BEGIN TO PUSH EAST OF THE
MID SOUTH TONIGHT AS A STRONG COLD FRONT SWEEPS THROUGH THE
AREA...BRINGING AN GRADUAL END TO SHOWER AND THUNDERSTORM CHANCES
BY CHRISTMAS EVE. HOWEVER...THIS IS NOT EXPECTED TO LAST LONG AS
THIS FRONT WILL STALL OUT AND RETURN BACK NORTH AS A WARM FRONT
CHRISTMAS EVE NIGHT INTO CHRISTMAS DAY. ANOTHER CHANCE FOR STRONG
TO SEVERE THUNDERSTORMS WILL BE POSSIBLE DURING THIS AND WILL BE
CLOSELY WATCHED IN UPCOMING FORECASTS.
LONG TERM MODELS INDICATE THE MID SOUTH WILL REMAIN IN A WARM
SECTOR FOR THE UPCOMING WEEKEND RESULTING IN A CONTINUED CHANCE
FOR SHOWERS AND THUNDERSTORMS. AN UPPER LEVEL LOW IS EXPECTED TO
DEVELOP AND MOVE FROM THE SOUTHERN PLAINS INTO THE MIDDLE/LOWER
MISSISSIPPI VALLEYS BY EARLY NEXT WEEK. THIS MAY POSE YET ANOTHER
POTENTIAL FOR STRONG TO SEVERE THUNDERSTORMS BETWEEN SUNDAY NIGHT
TO MONDAY NIGHT. CONFIDENCE IS LOW AT THIS MOMENT DUE TO
PERSISTENT RUN TO RUN CONTINUITY ISSUES WITH THIS PARTICULAR
SYNOPTIC SYSTEM. STAY TUNED...
CJC
&&
.AVIATION...
12Z TAFS
DEEP SUBTROPICAL MOISTURE WILL PREVAIL TODAY...WITH STRONG
VERTICAL WIND SHEER SUPPORTIVE OF A DEVELOPING LINE OF INTENSE
SURFACE-TSRA AFTER 18Z. HRRR AND NAM INDICATED A BROKEN LINE OF
TSRA. FOR THIS MORNING...SHRA/TSRA WILL BE ROOTED IN AN ELEVATED
LAYER ABOVE THE MOIST LOW LEVEL INVERSION.
PROSPECTS FOR A MVFR/VFR LATE EVENING MEM ARRIVAL PUSH APPEAR
PROMISING...ASSUMING POST FRONTAL STRATUS DEPICTED ON THE 06Z NAM
BUFR SOUNDINGS DOES NOT MATERIALIZE.
PWB
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1133 PM CST TUE DEC 22 2015
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 907 PM CST TUE DEC 22 2015/
UPDATE...
A WARM FRONT CURRENTLY STRETCHES FROM NEAR SEARCY ARKANSAS TO
TIPTONVILLE TENNESSEE. DENSE FOG HAS DEVELOPED JUST AHEAD OF THE
FRONT ACROSS PORTIONS OF NORTHEAST ARKANSAS AND THE MISSOURI
BOOTHEEL. THE FOG WILL DISSIPATE AS THE FRONT PUSHES
NORTHWARD...MAY NEED TO EXTEND THE TIMING FOR THE DENSE FOG
ADVISORY FOR RANDOLPH AND LAWRENCE COUNTIES A LITTLE PAST MIDNIGHT
BUT WILL HOLD OFF ON A DECISION FOR ANOTHER ONE TO TWO HOURS.
TEMPERATURES HAVE DROPPED LOWER THAN THE FORECASTED LOWS ACROSS
NORTHEAST ARKANSAS DUE TO THE SLOWNESS OF THE FRONT. HOWEVER THEY
ARE LIKELY AT OR NEAR THE LOW AT THIS TIME AND SHOULD RISE
OVERNIGHT AS THE FRONT PUSHES THROUGH.
MEANWHILE...STILL WAITING FOR GENERATION OF THUNDERSTORMS TO OCCUR
IN ARKLATEX WHICH SHOULD HAPPEN IN THE NEXT 2 TO 3 HOURS. THESE
THUNDERSTORMS WILL PUSH INTO EASTERN ARKANSAS BETWEEN 4-6 AM CST. HOWEVER
A MORE IMMEDIATE CONCERN MAY BE THE LARGE AREA OF RAIN THAT IS
OCCURRING ACROSS SOUTHERN MISSISSIPPI TONIGHT. THE RAIN SEEMS TO
BE ASSOCIATED WITH A SECONDARY BOUNDARY. THE 18Z GFS SHOWS THIS
AREA WITH SOME ADDITIONAL DEVELOPMENT OVER NE LOUISIANA CREEPING
INTO NORTH MISSISSIPPI OVERNIGHT WHILE THE NAM KEEPS THE RAIN TO
THE SOUTH AND EAST OF THE CWA. THE HRRR HAS BEEN IN AGREEMENT WITH
THE NAM UP UNTIL THE LAST RUN AT 1Z WHICH SEEMS TO BE SOMEWHAT IN
BETWEEN. FOR NOW LIKELY POPS ACROSS THE WESTERN HALF OF THE CWA
AND ACROSS PORTIONS OF NORTHEAST MISSISSIPPI SEEMS REASONABLE.
KRM
DISCUSSION... /ISSUED 308 PM CST TUE DEC 22 2015/
THE POTENTIAL FOR A SIGNIFICANT SEVERE THUNDERSTORM OUTBREAK
ACROSS THE ENTIRE MIDSOUTH CONTINUES TO INCREASE STRONG TORNADOES
ARE POSSIBLE...
AN ABNORMAL WEATHER PATTERN IS IN PLACE ACROSS THE
MIDSOUTH...FEATURING VERY UNSTABLE CONDITIONS AND WHAT LOOKS TO BE
AN ADEQUATE AMOUNT OF SHEAR TO BALANCE THE THERMODYNAMICS.
TEMPERATURES ARE IN THE MIDDLE 60S TO LOW 70S ACROSS THE
REGION...AROUND 25 DEGREES ABOVE NORMAL. DEW POINTS ARE IN THE
UPPER 50S TO LOW 60S...BUT SOUTHERLY WIND WILL KEEP DEWPOINTS
RISING AS GULF MOISTURE FLOODS THE MIDSOUTH. OVER THE NEXT 24
HOURS OR SO A VERY BROAD TROUGH WILL SHIFT ACROSS THE PLAINS. LATE
TONIGHT INTO EARLY TOMORROW ITS AXIS SHOULD BE OVER CENTRAL
OKLAHOMA...WITH A NEGATIVELY TILTED SHORTWAVE APPROACHING THE
MISSISSIPPI RIVER VALLEY. ONE OF THE MORE SIGNIFICANT CHANGES IN
MODEL GUIDANCE OVER THE LAST 24 HOURS IS THE DEVELOPMENT OF
DIURNAL THUNDERSTORMS ALONG AND WEST OF THE MISSISSIPPI RIVER
TONIGHT. BOTH THE NAM AND GFS INDICATE IN EXCESS OF 1000 J/KG CAPE
IN PLACE AS THE SHORTWAVE APPROACHES. A STRONG LLJ NEAR 100KT IS
ALREADY IN PLACE...STREAMING FROM THE SOUTHWEST GULF OF MEXICO
ACROSS THE MIDSOUTH. IF THUNDERSTORMS DEVELOP...THEY WOULD ALMOST
CERTAINLY QUICKLY STRENGTHEN TO SEVERE LIMITS. SIGNIFICANT HEIGHT
FALLS...ON THE ORDER OF 4DM/12HR WILL BEGIN AROUND MIDNIGHT...WITH
AS MUCH AS 8DM/12HR MY MIDDAY TOMORROW. THE STORM PREDICTION
CENTER HAS INCLUDED MOST OF THE MIDSOUTH WEST OF THE MISSISSIPPI
RIVER IN AN ENHANCED OUTLOOK FOR SEVERE THUNDERSTORMS TONIGHT.
STILL FEEL LIKE THE MOST WIDESPREAD AND STRONGEST STORMS WILL BE
TOMORROW...WITH THE HIGHEST THREAT ALONG THE SOUTH OF THE INTERSTATE
40 CORRIDOR...BUT SEVERE WEATHER IS POSSIBLE ACROSS ALL OF THE
MIDSOUTH. THE STRONG LLJ WILL BRING A COASTAL AIRMASS ACROSS THE
MIDSOUTH TOMORROW AFTERNOON. DEW POINTS WILL CERTAINLY BE IN THE
MIDDLE 60S ACROSS MOST OF THE AREA...AND MAY CLIMB INTO THE UPPER
60S IN NORTH MISSISSIPPI. RESULTING SURFACE BASED INSTABILITY
COULD EXCEED 1200J/KG. LOW LEVEL LAPSE RATES ON THE ORDER OF 6C
AND 30-40 DEGREES OF DIFFLUENCE ALOFT SHOULD HELP MAINTAIN
SUSTAINED HEALTHY UPDRAFTS. 0-3KT SRH WILL BE IN EXCESS OF
300M^2/S^2 IN NORTH MISSISSIPPI TOMORROW AT MIDDAY...WEAKENING
ONLY SLIGHTLY TO AROUND 250M^2/S^2 BY SUNSET. AS A RESULT A FEW
STRONG TORNADOES ARE POSSIBLE...ESPECIALLY IN NORTH MISSISSIPPI.
IN ADDITION...DAMAGING WIND AND LARGE HAIL ARE THREATS AREA WIDE
TOMORROW. THE SEVERE THREAT SHOULD DIMINISH AFTER SUNSET.
THURSDAY SHOULD BE MOSTLY DRY...ALTHOUGH A FEW SHOWERS MAY LINGER
IN FAR EASTERN PORTIONS OF THE MIDSOUTH NEAR THE ALABAMA STATE
LINE AND TENNESSEE RIVER.
WE WILL REMAIN IN AN ACTIVE PATTERN
AFTER TOMORROW. FRIDAY THROUGH MONDAY...LONG RANGE MODELS INDICATE
THE FRONT WILL BEGIN TO RETURN BACK NORTH AS A WARM FRONT ACROSS
THE FORECAST AREA ON CHRISTMAS DAY. THIS WILL RESULT IN THE
DEVELOPMENT OF ADDITIONAL SHOWERS AND THUNDERSTORMS ACROSS THE MID
SOUTH THURSDAY NIGHT AND ESPECIALLY ON FRIDAY. ADDITIONAL STRONG
TO SEVERE THUNDERSTORMS MAY BE POSSIBLE ON CHRISTMAS DAY. LONG
TERM MODELS BEGIN TO DIVERGE GREATLY WITH RUN TO RUN CONTINUITY AS
AN UPPER LEVEL LOW MOVES FROM THE PLAINS INTO THE MISSISSIPPI
VALLEY TOWARDS EARLY NEXT WEEK. THUS OVERALL CONFIDENCE IN
PRECIPITATION CHANCES MAY NEED TO BE ADJUSTED IN SUBSEQUENT
FORECASTS FOR THIS WEEKEND AND ESPECIALLY EARLY NEXT WEEK.
30
&&
.AVIATION...
06Z TAFS
MVFR CIGS EXPECTED OVERNIGHT. STRENGTHENING SOUTH WINDS AND
RESULTANT MIXING SHOULD HELP PREVENT WIDESPREAD IFR CIGS. A
STRONG STORM SYSTEM WILL TRACK INTO THE REGION AND SHRAS/TSRAS NOW
DEVELOPING OVER EAST TX/LA WILL MOVE INTO THE MIDSOUTH LATE
TONIGHT INTO WED AM. A COUPLE OF ROUNDS OF SHRAS/TSRAS ARE
POSSIBLE ACROSS THE AREA THROUGH EARLY WED EVENING. SEVERE WEATHER
LIKELY. GENERALLY MVFR CIGS EXPECTED THROUGH THE DAY WITH OCNL
IFR CIGS IN THE MORNING IN SHRAS/TSRAS. CONDS WILL BEGIN TO
IMPROVE TO VFR AT KJBR AND KMEM WED EVENING. LOW CLOUDS WILL
LINGER AT KMKL AND KTUP THROUGH THE END OF THE PERIOD.
WINDS WILL QUICKLY INCREASE AND BECOME GUSTY OVERNIGHT. STRONG
GUSTY SOUTH WINDS EXPECTED WED ESPECIALLY AT KJBR/KMEM WHERE GUSTS
COULD HIT 30 KTS. WINDS WILL DIMINISH LATE IN THE AFTERNOON/EARLY
EVENING AND VEER TO THE SW.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1215 PM CST WED DEC 23 2015
.AVIATION...
CLEARING SKIES THIS AFTERNOON BEHIND A WEAK FRONT THAT MOVED
THROUGH THE FORECAST AREA THIS MORNING. MODERATE TO STRONG WINDS
WILL GRADUALLY DIMINISH BY MID-LATE AFTERNOON AS THE SURFACE
GRADIENT RELAXES BEHIND THE FRONT. CLEAR SKIES AND LIGHT WINDS
EXPECTED TONIGHT. PATCHY FOG POSSIBLE TOMORROW MORNING BETWEEN
HOUSTON METRO AREA AND THE COAST...HOWEVER HIGH CLOUDS SHOULD
LIMIT ANY DENSE STRATUS/FOG FORMATION. MVFR CIG CONDITIONS
POSSIBLE AT KGLS AND KLBX TOMORROW MORNING AS A WEAK STATIONARY
FRONT ALONG THE COAST BEGINS TO MOVE INLAND AS A WEAK WARM FRONT.
44
&&
.PREV DISCUSSION... /ISSUED 1130 AM CST WED DEC 23 2015/
DISCUSSION...
FRONTAL BOUNDARY CONTINUING TO MOVE ACROSS SE TX AT PRESENT AND WE
ARE SEEING MUCH LOWER DEWPTS IN ITS WAKE. THE PATCHY FOG ALONG THE
COAST/BAYS SHOULD NOT LAST MUCH LONGER THIS AFTN. OTHERWISE NO BIG
CHANGES WITH THE CURRENT FCST PLANNED ATTM. 41
PREV DISCUSSION... /ISSUED 533 AM CST WED DEC 23 2015/
AVIATION...
A S/WV TROUGH WILL MOVE EAST OF THE REGION TODAY. STILL SOME
POTENTIAL FOR A FEW SHOWERS OVER THE NORTHERN TAF SITES THIS
MORNING. MUCH DRIER AIR WILL WORK INTO THE REGION FROM THE WEST BY
AFTERNOON WITH SFC WINDS VEERING TO THE W-SW. VFR CONDS EXPECTED
TO DEVELOP BETWEEN 17-19Z AREAWIDE. FCST SOUNDINGS SHOW CLEAR
SKIES OVERNIGHT. COASTAL TAF SITES MAY SUFFER SOME VSBY
RESTRICTIONS LATE TONIGHT. THE HRRR SHOWS AN AREA OF SEA FOG
DEVELOPING OFF THE LOUISIANA COAST AND MOVING WEST TONIGHT. THE
FOG WILL PROBABLY IMPACT KGLS/KLBX AFTER 08Z AND KHOU AFTER 10Z.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 55 77 65 78 69 / 10 10 40 50 50
HOUSTON (IAH) 56 80 67 79 69 / 10 20 40 50 40
GALVESTON (GLS) 63 74 67 74 68 / 10 20 40 50 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CST THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY.
SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...41
AVIATION/MARINE...44
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1130 AM CST WED DEC 23 2015
.DISCUSSION...
FRONTAL BOUNDARY CONTINUING TO MOVE ACROSS SE TX AT PRESENT AND WE
ARE SEEING MUCH LOWER DEWPTS IN ITS WAKE. THE PATCHY FOG ALONG THE
COAST/BAYS SHOULD NOT LAST MUCH LONGER THIS AFTN. OTHERWISE NO BIG
CHANGES WITH THE CURRENT FCST PLANNED ATTM. 41
&&
.PREV DISCUSSION... /ISSUED 533 AM CST WED DEC 23 2015/
AVIATION...
A S/WV TROUGH WILL MOVE EAST OF THE REGION TODAY. STILL SOME
POTENTIAL FOR A FEW SHOWERS OVER THE NORTHERN TAF SITES THIS
MORNING. MUCH DRIER AIR WILL WORK INTO THE REGION FROM THE WEST BY
AFTERNOON WITH SFC WINDS VEERING TO THE W-SW. VFR CONDS EXPECTED
TO DEVELOP BETWEEN 17-19Z AREAWIDE. FCST SOUNDINGS SHOW CLEAR
SKIES OVERNIGHT. COASTAL TAF SITES MAY SUFFER SOME VSBY
RESTRICTIONS LATE TONIGHT. THE HRRR SHOWS AN AREA OF SEA FOG
DEVELOPING OFF THE LOUISIANA COAST AND MOVING WEST TONIGHT. THE
FOG WILL PROBABLY IMPACT KGLS/KLBX AFTER 08Z AND KHOU AFTER 10Z.
43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 55 77 65 78 / 20 10 10 40 50
HOUSTON (IAH) 82 56 80 67 79 / 30 10 20 40 50
GALVESTON (GLS) 77 63 74 67 74 / 20 10 20 40 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 4 PM CST THIS
AFTERNOON FOR THE FOLLOWING ZONES: GALVESTON BAY...
MATAGORDA BAY...WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND TO FREEPORT OUT
20 NM.
SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
533 AM CST WED DEC 23 2015
.AVIATION...
A S/WV TROUGH WILL MOVE EAST OF THE REGION TODAY. STILL SOME
POTENTIAL FOR A FEW SHOWERS OVER THE NORTHERN TAF SITES THIS
MORNING. MUCH DRIER AIR WILL WORK INTO THE REGION FROM THE WEST BY
AFTERNOON WITH SFC WINDS VEERING TO THE W-SW. VFR CONDS EXPECTED
TO DEVELOP BETWEEN 17-19Z AREAWIDE. FCST SOUNDINGS SHOW CLEAR
SKIES OVERNIGHT. COASTAL TAF SITES MAY SUFFER SOME VSBY
RESTRICTIONS LATE TONIGHT. THE HRRR SHOWS AN AREA OF SEA FOG
DEVELOPING OFF THE LOUISIANA COAST AND MOVING WEST TONIGHT. THE
FOG WILL PROBABLY IMPACT KGLS/KLBX AFTER 08Z AND KHOU AFTER 10Z.
43
&&
.PREV DISCUSSION... /ISSUED 509 AM CST WED DEC 23 2015/
SHORT TERM /TODAY THROUGH CHRISTMAS EVE DAY/...
REGARDING TORNADO WATCH 556... THERE HAS BEEN LIMITED CONVECTIVE
DEVELOPMENT OVER THE WATCH AREA OVER THE PAST FEW HOURS. DESPITE
SUFFICIENT FORCING FOR ASCENT AHEAD OF A SHORTWAVE TROUGH SWINGING
ACROSS THE SOUTHERN PLAINS... A RELATIVELY STABILIZED ATMOSPHERE
APPEARS TO BE LIMITING ADDITIONAL DEVELOPMENT. AFTER COORDINATION
WITH SPC... HAVE OPTED TO CANCEL THE WATCH WITH THE MORNING
PACKAGE. CANNOT RULE OUT AN ISOLATED SHOWER OR STORM DEVELOPING
THROUGH THE REMAINDER OF THE EARLY MORNING HOURS OVER THE
NORTHEASTERN COUNTIES HOWEVER.
FOR THE REMAINDER OF TODAY... A SURFACE LOW PRESSURE SYSTEM
LOCATED OVER NORTHWEST OKLAHOMA/ WESTERN KANSAS INDUCED BY THE
SHORTWAVE TROUGH WILL EJECT NORTHEAST TOWARDS MISSOURI. THIS WILL
DRAG AN ATTENDANT SURFACE TROUGH ACROSS TEXAS... WITH A TIGHT
PRESSURE GRADIENT IN RESPONSE TO THE SURFACE LOW RESULTING IN
ELEVATED SOUTHERLY WINDS ACROSS SOUTHEAST TEXAS FOR MOST OF THE
DAY. AS THE SURFACE TROUGH MOVES INTO THE REGION LATER THIS
MORNING... SOME HIGH RESOLUTION GUIDANCE BREAKS OUT SCATTERED
SHOWERS ALONG AND AHEAD OF THIS FEATURE. BEST CHANCES /30-40 POPS/
APPEAR TO BE NORTH OF THE INTERSTATE 10 AND WEST OF THE
INTERSTATE 45 CORRIDORS WITH AN ISOLATED LIGHTNING STRIKE OR TWO
ALSO POSSIBLE WITH MID-LEVEL LAPSE RATES AROUND 7 TO 7.5 J/KG.
UPPER FORCING ASSOCIATED WITH THE SOUTHERN PLAINS SHORTWAVE IS
EXPECTED TO LIFT NORTHEAST OF THE REGION BY MIDDAY AND LOSS OF
THIS FORCING COUPLED WITH DRIER AIR BEHIND THE SURFACE TROUGH IS
EXPECTED TO END RAIN CHANCES BY THIS AFTERNOON.
CLOUDS ARE ALSO EXPECTED TO CLEAR FROM WEST TO EAST DURING THE DAY AS
DRIER AIR MOVES INTO THE REGION... AND THIS WILL ALLOW THE REGION
TO TAKE ADVANTAGE OF ENOUGH INSOLATION FOR AFTERNOON TEMPERATURES
TO RISE INTO THE UPPER 70S TO EVEN LOW 80S. MOSTLY CLEAR TO PARTLY
CLOUDY SKIES AND DRIER CONDITIONS WILL ALLOW OVERNIGHT LOWS TO
FALL A FEW DEGREES BELOW WHAT WE/LL OBSERVE THIS MORNING /NEAR
RECORD MAXIMUM LOW TEMPERATURES POSSIBLE IN A FEW LOCATIONS/.
CHRISTMAS EVE DAY WILL BE A RELATIVELY DRY ONE FOR THE REGION...
WITH ONLY ISOLATED WARM AIR ADVECTION SHOWERS POSSIBLE DURING THE
DAY AS A SURGE OF MOISTURE MOVES IN OFF THE GULF. THIS MOISTURE WILL
ALSO RESULT IN INCREASING CLOUDS... WITH TEMPERATURES ON CHRISTMAS
EVE DAY STILL WARM BUT A DEGREE OR TWO COOLER THAN TODAY OWING TO
CLOUD COVER.
HUFFMAN
LONG TERM /CHRISTMAS EVE NIGHT THROUGH TUESDAY/...
BY CHRISTMAS EVE NIGHT... AN INCREASING LOW LEVEL JET ACROSS THE
REGION WILL PUSH MORE GULF MOISTURE INTO THE REGION AND RESULT IN
SHOWER AS WELL AS THUNDERSTORM DEVELOPMENT. INCREASING SHEAR AS
THE LOW LEVEL JET INTENSIFIES WILL POSSIBLY CREATE THE POTENTIAL
FOR ORGANIZED STORMS /SOME POSSIBLY STRONG/ GENERALLY EAST OF
INTERSTATE 45 EARLY CHRISTMAS MORNING... BUT WITH BEST JET
DYNAMICS NORTH OF THE REGION CONFIDENCE IS LOW IN OCCURRENCE AT
THIS TIME.
FOR CHRISTMAS... WAVES OF SHOWERS AND THUNDERSTORMS WILL CONTINUE
TO MOVE ACROSS THE REGION FROM SOUTH TO NORTH DURING THE DAY WITH
HIGH TEMPERATURES TOPPING OUT IN THE MID 70S TO NEAR 80. FOR WHAT
IT IS WORTH... THE AVERAGE HIGH FOR HOUSTON ON CHRISTMAS IS 61.2
DEGREES.
THIS WEEKEND... ATTENTION TURNS TO A MAJOR STORM SYSTEM
APPROACHING TEXAS BY SATURDAY. DIFFERENCES STILL EXIST IN THE
SPEED/TIMING OF THE SYSTEM... WITH THE CANADIAN/EUROPEAN SIDING
WITH A MORE SOUTHERLY AND SLOWER PATH OF THE UPPER TROUGH ACROSS
TEXAS AND THE GFS SOMEWHAT QUICKER AND FARTHER NORTH.
REGARDLESS... THE GENERAL TREND IN GUIDANCE IS FOR THE UPPER
TROUGH TO BECOME NEGATIVELY TILTED OVER THE REGION DURING THE LATE
WEEKEND /SUNDAY INTO EARLY MONDAY/. THIS OFFERS SOME INCREASING
CONFIDENCE FOR A SEVERE WEATHER THREAT FOR MUCH OF THE REGION ON
SUNDAY... POSSIBLY WITH DISCRETE THUNDERSTORMS AHEAD OF A SQUALL
LINE AND ATTENDANT COLD FRONT DURING THE LATE WEEKEND. WILL ALSO
NEED TO MONITOR FOR THE POTENTIAL OF AT LEAST A LOCALIZED HEAVY
RAIN THREAT WITH FORECAST PRECIPITABLE WATER VALUES NEARING THE
99TH PERCENTILE ACROSS MUCH OF THE REGION SATURDAY AND SUNDAY.
FOR THE BEGINNING OF NEXT WEEK... DRIER AND COOLER AIR BEHIND
THE LATE WEEKEND FRONT WILL KEEP THE BEGINNING OF NEXT WEEK DRY.
MEDIUM RANGE GUIDANCE CONTINUES TO TREND TEMPERATURES DOWN FOR
THIS PORTION OF THE FORECAST... WITH BELOW NORMAL TEMPERATURES
POSSIBLE FOR THE LAST FEW DAYS OF DECEMBER.
HUFFMAN
MARINE...
WILL MAINTAIN THE SCA FOR THE 20-60 NM WATERS AS WINDS INCREASE IN
RESPONSE TO A DEEPENING AREA OF LOW PRESSURE OVER THE SOUTHERN
PLAINS. THE STRONGEST WINDS ARE EXPECTED THIS MORNING WITH SOME
DECREASE IN SPEEDS BY LATE AFTN. A FLATTER PRESSURE GRADIENT IS
EXPECTED TONIGHT AND THURSDAY AND WINDS WILL RELAX. THE LULL IN
HIGHER IN WIND SPEEDS WILL BE SHORT LIVED AS THE GRADIENT TIGHTENS
IN RESPONSE TO YET ANOTHER AREA OF LOW PRESSURE DEVELOPING OVER THE
WESTERN PLAINS ON FRIDAY. SCEC CONDITIONS POSSIBLE BY FRIDAY AFTN
OVER THE 20-60 NM WATERS WITH SCA CONDS LIKELY OVER THE 20-60 NM
WATERS BOTH SAT/SUN. CONDITIONS REMAIN SOMEWHAT FAVORABLE FOR SEA
FOG THROUGH THE WEEKEND AS SFC DEW PTS REMAIN 6-10 DEGREES WARMER
THAN THE WATER TEMP BUT IDEAL CONDITIONS WOULD HAVE MORE OF AN EAST
WIND AND NOT S-SE.
A STRONG COLD FRONT WILL CROSS THE COASTAL WATERS SUNDAY NIGHT OR
EARLY MONDAY MORNING. A LINE OF STRONG STORMS IS EXPECTED ALONG THE
FRONT AND AN ABRUPT WIND SHIFT TO THE WEST-NORTHWEST IN THE WAKE OF
THE FRONT. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 79 55 77 65 78 / 20 10 10 40 50
HOUSTON (IAH) 82 56 80 67 79 / 30 10 20 40 50
GALVESTON (GLS) 77 63 74 67 74 / 20 10 20 40 50
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL
20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO FREEPORT 20 TO
60 NM.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
925 PM EST THU DEC 24 2015
.SYNOPSIS...
AN ABNORMALLY WARM AND MOIST AIRMASS WILL REMAIN OVER THE REGION
THROUGH THE END OF THE WEEK. A COLD FRONT HAS STALLED FROM THE
MID ATLANTIC STATES INTO THE TENNESSEE VALLEY AND WILL REMAIN IN
THE REGION THROUGH FRIDAY NIGHT. THIS WILL RESULT SEVERAL PERIODS
OF SHOWERS FOR OUR AREA FOR THE NEXT SEVERAL DAYS.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 910 PM EST THURSDAY...
FORCING FOR ADDITIONAL RAINFALL IS LIMITED ACROSS OUR AREA AT THE
MOMENT THIS EVENING. REGIONAL RADAR SHOWS CLUSTER OF DEEP
CONVECTION FROM UPSTATE SOUTH CAROLINA SOUTHWEST INTO SOUTHEAST
ALABAMA. THE LATEST HRRR AND RAP13 SHOW THIS AREA TRYING TO MAKE
INROADS TOWARD OUR SRN BORDER BY 12Z...WHILE WEAKENING IT OVERALL.
THE 00Z NAM HAS COME IN TOO HOT OVER US INDICATING SHOWERS ALREADY
ACROSS THE WV/VA BORDER WHICH IS NOT THE CASE. THE 18Z GFS SHOWED
SOME GOOD SYNOPTIC PATTERN TO WHAT IS GOING ON.
WITH THAT IN MIND WILL BE CUTTING BACK POPS EARLY ON OVERNIGHT
THEN SHIFTING THEM MORE INTO HIGHER CHANCE TO LOW LIKELYS BY
12-15Z IN THE SRN CWA...AS BETTER UPPER DIVERGENCE ARRIVES.
PRIOR TO ALL OF THIS WE ARE DEALING WITH SOME FOG AGAIN WHERE THE
LOWER CLOUDS HAD SCOURED OUT. THIS MAINLY IS PREVALENT IN THE NEW
RIVER VALLEY AND GREENBRIER VALLEYS. AN SPS HAS BEEN ISSUED TO
ACCOUNT FOR THIS...AND WILL NOT ISSUE A DENSE FOG ADVISORY ATTM
THINKING WE WILL SEE LOWER CLOUDS MOVING IN ALLOWING FOR SOME FOG
DISPERSION.
WITH SOME CLEARING TEMPS MANAGED TO DROP INTO THE MID 50S OVER
SOME OF THE VALLEYS...SO AN UPDATE TO LOWER THE LOWS SOME...THOUGH
THROUGH THE OVERNIGHT WILL SEE TEMPS STEADY OUT OR RISE.
NO CHANGES TO THE FLASH FLOOD WATCH...BUT THREAT WILL BE DELAYED
UNTIL AFTER DAWN CHRISTMAS.
PREVIOUS VALID DISCUSSION...
EXPECT MODERATE TO HEAVY RAIN WILL GREATLY INCREASE THE POTENTIAL
FOR FLASH FLOODING DURING THE DAY FRIDAY. HIGHS FRIDAY WILL BE
MILD ONCE AGAIN IN THE 60S...WITH LOWER 70S EAST.
SEE CLIMATE SECTION OR LATEST PUBLIC INFORMATION STATEMENT FOR
DETAILS.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 315 PM EST THURSDAY...
BLACKSBURG FORECAST AREA EXPECTED TO REMAIN IN A SQUEEZE PLAY
BETWEEN A STRONG TROPICAL RIDGE OF HIGH PRESSURE OFF THE SE COAST
OF THE NATION AND SURFACE HIGH PRESSURE WITH COOLER AND DRIER AIR
PUSHING EAST ACROSS NEW ENGLAND BEHIND A SHORT WAVE TROF IN THE
NORTHERN STREAM. BATTLE...AT LEAST DURING THE SHORT TERM
PERIOD...WILL EVENTUALLY BE WON BY THE HIGH PRESSURE RIDGE TO OUR
SOUTHEAST AS IT SLOWLY STRENGTHENS AND RETROGRADES WEST CLOSER TO
THE SE COAST.
AS A RESULT...AREA OF LOW LEVEL CONFLUENCE THAT HAS SERVED TO
FOCUS SHOWER AND THUNDERSTORM ACTIVITY THE PAST COUPLE OF
DAYS...SHOULD GRADUALLY TRANSITION FROM THE SOUTHERN PORTION OF
THE BLACKSBURG FORECAST AREA FRIDAY MORNING TO THE NORTHERN HALF
OF THE AREA FRIDAY AFTERNOON INTO FRIDAY NIGHT...WITH PRIMARY AXIS
OF CONVERGENCE CONTINUING TO PUSH SLOWLY NORTH TO NORTH OF THE
FORECAST AREA SATURDAY INTO SATURDAY NIGHT.
AIRMASS OVER THE AREA REMAINS EXCEPTIONALLY WARM AND MOIST...WITH
PRECIPITABLE WATER VALUES REMAINING IN THE 1.6-1.8 INCH
RANGE....SOME 350% ABOVE NORMAL. FORECAST SOUNDINGS THROUGH THE
PERIOD YIELD LIFTED INDEX VALUES IN ZERO TO -3C RANGE...WITH
CONVECTIVE AVAILABLE ENERGY IN THE 750-1250 J/KG RANGE. WEAK
VERTICAL MOTION THROUGH A NEARLY SATURATED CONDITIONALLY UNSTABLE
AIRMASS WILL CONTINUE TO RESULT IN SHOWER/THUNDERSTORM GENERATION
WITH HIGH PRECIPITATION EFFICIENCY.
WITH MANY AREAS ALREADY EXPERIENCING NEARLY SATURATED GROUND
CONDITIONS AND HIGH STREAM/RIVER LEVELS FROM EARLIER RAINS...
ADDITIONAL RAINFALL RUNOFF HAS A HIGH PROBABILITY OF INITIATING
FLASH FLOODING WHERE RAINFALL RATES ARE MAXIMIZED AND/OR WHERE
TRAINING OF STRONGER CELLS OCCUR. AT A MINIMUM...ADDITIONAL RUNOFF
WILL MAINTAIN HIGH FLOW CONDITIONS AND PROLONG ABOVE FLOOD LEVEL
READINGS OF RIVERS THAT ARE ALREADY IN FLOOD.
AS A RESULT...A FLASH FLOOD WATCH WILL CONTINUE THROUGHOUT
CHRISTMAS DAY FOR THE ENTIRE BLACKSBURG FORECAST AREA UNTIL THE
THREAT FOR THE AXIS OF WIDESPREAD HEAVY RAIN NEAR ZONE OF BEST LOW
LEVEL CONFLUENCE FINALLY SHIFTS NORTH OF THE AREA.
TEMPERATURES THROUGH THE ENTIRE SHORT TERM PERIOD WILL REMAIN
CLOSE TO OR EXCEEDING RECORD LEVELS...BOTH FOR VERY HIGH NIGHTTIME
LOWS...WHICH WILL REMAIN NEARLY 30F ABOVE SEASONAL NORMALS AND
AROUND 15F HIGHER THAN WHAT WOULD NORMALLY BE EXPECTED FOR A
DAYTIME HIGH TEMPERATURE...WITH DAYTIME HIGH TEMPERATURES AT LEAST
20F ABOVE SEASONAL NORMALS...AGAIN BREAKING RECORDS. REFER TO
CLIMATOLOGICAL SECTION FOR SPECIFICS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM EST WEDNESDAY...
NEXT WEEK WILL CONTINUED TO BE VERY WARM AND UNSETTLED. BY SUNDAY
MORNING A CLOSED 500MB LOW ACROSS TEXAS WILL BEGIN TO PIVOT
NORTHEAST TOWARDS THE CENTRAL GREAT LAKES BY TUESDAY. A SURFACE
FRONTAL BOUNDARY DRAPED FROM THE OHIO VALLEY TO THE SOUTHERN
PLAINS WILL MEANDER CLOSE TO THE REGION SUNDAY AND MONDAY KEEPING
A CHANCE OF SHOWERS. GREATEST THREAT FOR SHOWERS WILL BE TUESDAY
AS THE FRONT OCCLUDES AND SLOWLY PUSHES THROUGH OUR REGION AND
EVENTUALLY STALLING TO OUR SOUTHEAST ON WEDNESDAY.
SUNDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH 850MB TEMPS
APPROACHING +15C. TEMPS BACK OFF TO +5-10C MONDAY THROUGH THURSDAY
BEFORE THE COLDER AIR ARRIVES FRIDAY.
MODELS TEND TO AGREE THAT THE END OF THE WEEK WILL FEATURE A PUSH
OF MUCH COLDER AND DRIER AIR INTO THE REGION AS A SHORTWAVE DIGS
IN. DIFFERENCES EXIST AS TO HOW DEEP THAT PUSH OF COLDER AIR WILL
BE AND HOW MUCH IF ANY MOISTURE WILL BE AVAILABLE FOR ANY
POTENTIAL UPSLOPE PRECIP/CLOUDS LATE IN THE WEEK.
&&
.AVIATION /02Z FRIDAY THROUGH TUESDAY/...
AS OF 630 PM EST THURSDAY...
DUE TO AN OUTAGE AT KDAN EARLIER...AND JUST ONE OBSERVATION IN SINCE
21Z...WILL KEEP AMD NOT SKED IN THE TAF UNTIL PERSISTENT OBS
ARE COMING IN.
THERE WILL BE A BREAK IN SHOWERS THIS EVENING. LOW LVL MOISTURE IS
MORE PREVALENT EAST OF THE BLUE RIDGE WITH MORE MID/HIGH CLOUDS IN
THE WEST. THIS LACK OF LOWER CIGS IN THE WEST COULD ALLOW FOR MORE
FOG FORMATION THIS EVENING BEFORE DEEPER MOISTURE MOVES BACK IN
TOWARD MORNING. WILL VARY THE TAFS MORE TOWARD MVFR/VFR EARLY THEN
IFR/MVFR OVERNIGHT INTO FRIDAY MORNING. FRONTAL BOUNDARY STALLED
IN THE MTNS WILL START TO RETROGRADE WWD FRIDAY AFTERNOON AS HIGH
PRESSURE OVER THE WRN ATLANTIC BUILDS WEST. THIS WILL SET UP A
BETTER THREAT OF SHOWERS ALONG/WEST OF THE BLUE RIDGE.
MODELS VARY SO CONFIDENCE IS LOW TO MEDIUM THIS PERIOD.
.EXTENDED AVIATION DISCUSSION...
THE CHANCE OF SHOWERS AND SUB-VFR CONDITIONS WILL CONTINUE INTO
THE WEEKEND...BUT OVERALL LESS LIKELY TO PERSIST IN THE IFR OR
WORSE VALUES AS ATMOSPHERE WILL BE A LITTLE BETTER MIXED AND
FREQUENCY OF SHOWERS MUCH LESS WITH NO KEY FEATURES TO HELP LIFT
THE MOIST ATMOSPHERE.
BEYOND THIS WEEKEND...MODELS CONTINUE TO VARY BUT SHOWING BETTER
THREAT OF SHOWERS AGAIN BY LATE MONDAY INTO TUESDAY WITH VFR TO
IFR AT TIMES.
&&
.HYDROLOGY...
AS OF 920 PM EST THURSDAY...
LULL IN THE RAINFALL TONIGHT...BUT MORE ON THE WAY BY CHRISTMAS
MORNING. HAVE SEVERAL RIVERS IN FLOOD ALREADY...MAINLY THE
DAN...AND LOWER ROANOKE. WE ALSO STILL HAVE SOME FLOODED ROADS IN
SOUTHSIDE VA INTO THE NW NC PIEDMONT...SO AREAL FLOOD WARNINGS
WILL CONTINUE THIS EVENING.
FOR FRIDAY...VERY HIGH PRECIPITABLE WATER VALUES WILL CONTINUE TO
BE ADVECTED INTO THE FORECAST AREA. UPPER DIFFLUENCE AND
VORTICITY ADVECTION WITH A SHORT WAVE TRACKING INTO THE SOUTHERN
APPALACHIANS WILL PROVIDE STRONG SYNOPTIC SCALE LIFT WHICH WILL BE
ENHANCED BY MODEST UPSLOPE ALONG THE BLUE RIDGE.
PRECIPITATION EFFICIENCY IS VERY HIGH FRIDAY. BASED ON THESE
EXPECTED RATES AND CONSIDERING THE LOCATIONS THAT HAVE HAD
SIGNIFICANT RAINFALL SO FAR THIS WEEK...A FLASH FLOOD WATCH HAS
BEEN EXTENDED FOR PARTS OF NORTHERN NORTH CAROLINA AND SOUTHERN
VIRGINIA INTO THE DAY FRIDAY. A NEW FLASH FLOOD WATCH WILL BEGIN
AT MIDNIGHT INTO FRIDAY EVENING FOR SOUTHWESTERN VIRGINIA AND
SOUTHEASTERN WEST VIRGINIA.
&&
.CLIMATE...
AS OF 230 PM EST THURSDAY...
WE BROKE 3 RECORD HIGHS TODAY 12/24...DANVILLE...BLACKSBURG AND
BLUEFIELD. SEE RERRNK FOR DETAILS.
WITH THE CONTINUING VERY WARM AIRMASS IN PLACE FOR THE NEXT SEVERAL
DAYS... MANY DAILY MAX TEMPERATURE RECORDS AS WELL AS HIGH MIN
TEMPERATURE RECORDS ARE LIKELY TO BE SET. FOR REFERENCE...HERE ARE
RECORDS FOR OUR CLIMATE STATIONS FOR THE NEXT SEVERAL DAYS.
FRIDAY 12/25/2015
SITE MAXT YEAR HIMIN YEAR
KBLF 64 1982 55 1982
KDAN 76 1955 48 1988
KLYH 72 1982 57 1964
KROA 68 1982 54 1964
KRNK 68 1964 41 1972
SATURDAY 12/26/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 62 1987 -3 1983 16 1977 55 1982
KDAN 75 1982 2 1983 18 1983 57 1964
KLYH 72 1922 1 1983 22 1914 58 1964
KROA 70 1964 3 1980 23 1985 56 1982
KRNK 64 1982 -8 1985 9 1983 50 1982
SUNDAY 12/27/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 69 2008 9 1977 20 2010 52 1982
KDAN 77 1982 6 1983 27 1985 54 1964
KLYH 71 1971 0 1914 21 1925 50 1940
KROA 69 1984 -3 1914 25 1935 52 1940
KRNK 67 2008 -6 1985 20 1985 52 1964
MONDAY 12/28/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 67 1984 4 1977 20 1995 53 1984
KDAN 72 1971 13 1966 28 1950 54 2008
KLYH 76 1984 6 1977 26 1950 51 1959
KROA 75 1984 4 1925 25 1925 51 1984
KRNK 66 1984 6 1977 28 1995 42 1959
&&
.EQUIPMENT...
AS OF 920 PM EST THURSDAY...
THE DANVILLE OBSERVATION APPEARS TO BE WORKING CONSISTENTLY
AGAIN...BUT WILL NEED TO BE MONITORED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR VAZ007-010>014-
017>020-022>024-033>035-045>047.
FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR VAZ009-015-016-
032-043-044-058-059.
NC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR WVZ042>044-507-
508.
&&
$$
SYNOPSIS...RCS
NEAR TERM...RCS/WP
SHORT TERM...WERT
LONG TERM...CF
AVIATION...RCS/WP
HYDROLOGY...WERT
CLIMATE...RCS
EQUIPMENT...RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
644 PM EST THU DEC 24 2015
.SYNOPSIS...
AN ABNORMALLY WARM AND MOIST AIRMASS WILL REMAIN OVER THE REGION
THROUGH THE END OF THE WEEK. A COLD FRONT HAS STALLED FROM THE
MID ATLANTIC STATES INTO THE TENNESSEE VALLEY AND WILL REMAIN IN
THE REGION THROUGH FRIDAY NIGHT. THIS WILL RESULT SEVERAL PERIODS
OF SHOWERS FOR OUR AREA FOR THE NEXT SEVERAL DAYS.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 610 PM EST THURSDAY...
FORECAST UPDATED TO ACCOUNT FOR LESS COVERAGE IN SHOWERS EARLY
THIS EVENING. THE 21Z RAP SHOWED THAT ANY COVERAGE WILL BE
SCATTERED AT BEST MAINLY EAST OF THE BLUE RIDGE THROUGH MIDNIGHT.
WILL HAVE TO WAIT FOR MOISTURE TRANSPORT WITH NEXT AREA OF
CONVECTION SC/GA TO MOVE TOWARD THE TRIAD TO SOUTHSIDE BY MIDNIGHT
TO EARLY MORNING. WILL STILL MAINTAIN SLIGHT CHANCE IN THE WEST
GIVEN HIGHER PWATS AND SOME LINGERING LOW LVL CONVERGENCE.
PREVIOUS DISCUSSION FROM MID AFTERNOON...
AN UPPER LEVEL RIDGE IN THE WESTERN ATLANTIC WILL CONTINUE TO
MOVE WESTWARD TONIGHT. THIS WILL KEEP A SERIES OF SHORT WAVES AND
A PIPELINE OF MOISTURE STREAMING IN OVER THE REGION
TONIGHT. CONVECTION ACROSS THE SOUTHEASTERN UNITED STATES MAY ROB
SOME OF OUR MOISTURE...BUT WITH AN ALREADY SATURATED GROUND AND
LOW FLASH FLOOD GUIDANCE...ANY MODERATE TO HEAVY RAIN WILL
GREATLY INCREASE THE POTENTIAL FOR FLASH FLOODING TONIGHT AND
INTO THE DAY TOMORROW. WITH THIS IN MIND...WE HAVE EXTENDED THE
FLASH FLOOD WATCH ACROSS NORTHERN NORTH CAROLINA AND SOUTHERN
VIRGINIA INTO FRIDAY EVENING. WE HAVE ALSO ISSUED A NEW FLASH
FLOOD WATCH FOR THE REST OF THE AREA STARTING AT MIDNIGHT AND
CONTINUING INTO FRIDAY EVENING.
WE HAVE SEVERAL RECORDS SET TO BE BROKEN FOR WARM MINIMUMS
TODAY. SEE CLIMATE SECTION OR LATEST PUBLIC INFORMATION STATEMENT
FOR DETAILS. THESE NEW RECORDS SHOULD HOLD THROUGH THIS EVENING
AS THE AIR MASS DOES NOT LOOK TO CHANGE.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AS OF 315 PM EST THURSDAY...
BLACKSBURG FORECAST AREA EXPECTED TO REMAIN IN A SQUEEZE PLAY
BETWEEN A STRONG TROPICAL RIDGE OF HIGH PRESSURE OFF THE SE COAST
OF THE NATION AND SURFACE HIGH PRESSURE WITH COOLER AND DRIER AIR
PUSHING EAST ACROSS NEW ENGLAND BEHIND A SHORT WAVE TROF IN THE
NORTHERN STREAM. BATTLE...AT LEAST DURING THE SHORT TERM
PERIOD...WILL EVENTUALLY BE WON BY THE HIGH PRESSURE RIDGE TO OUR
SOUTHEAST AS IT SLOWLY STRENGTHENS AND RETROGRADES WEST CLOSER TO
THE SE COAST.
AS A RESULT...AREA OF LOW LEVEL CONFLUENCE THAT HAS SERVED TO
FOCUS SHOWER AND THUNDERSTORM ACTIVITY THE PAST COUPLE OF
DAYS...SHOULD GRADUALLY TRANSITION FROM THE SOUTHERN PORTION OF
THE BLACKSBURG FORECAST AREA FRIDAY MORNING TO THE NORTHERN HALF
OF THE AREA FRIDAY AFTERNOON INTO FRIDAY NIGHT...WITH PRIMARY AXIS
OF CONVERGENCE CONTINUING TO PUSH SLOWLY NORTH TO NORTH OF THE
FORECAST AREA SATURDAY INTO SATURDAY NIGHT.
AIRMASS OVER THE AREA REMAINS EXCEPTIONALLY WARM AND MOIST...WITH
PRECIPITABLE WATER VALUES REMAINING IN THE 1.6-1.8 INCH
RANGE....SOME 350% ABOVE NORMAL. FORECAST SOUNDINGS THROUGH THE
PERIOD YIELD LIFTED INDEX VALUES IN ZERO TO -3C RANGE...WITH
CONVECTIVE AVAILABLE ENERGY IN THE 750-1250 J/KG RANGE. WEAK
VERTICAL MOTION THROUGH A NEARLY SATURATED CONDITIONALLY UNSTABLE
AIRMASS WILL CONTINUE TO RESULT IN SHOWER/THUNDERSTORM GENERATION
WITH HIGH PRECIPITATION EFFICIENCY.
WITH MANY AREAS ALREADY EXPERIENCING NEARLY SATURATED GROUND
CONDITIONS AND HIGH STREAM/RIVER LEVELS FROM EARLIER RAINS...
ADDITIONAL RAINFALL RUNOFF HAS A HIGH PROBABILITY OF INITIATING
FLASH FLOODING WHERE RAINFALL RATES ARE MAXIMIZED AND/OR WHERE
TRAINING OF STRONGER CELLS OCCUR. AT A MINIMUM...ADDITIONAL RUNOFF
WILL MAINTAIN HIGH FLOW CONDITIONS AND PROLONG ABOVE FLOOD LEVEL
READINGS OF RIVERS THAT ARE ALREADY IN FLOOD.
AS A RESULT...A FLASH FLOOD WATCH WILL CONTINUE THROUGHOUT
CHRISTMAS DAY FOR THE ENTIRE BLACKSBURG FORECAST AREA UNTIL THE
THREAT FOR THE AXIS OF WIDESPREAD HEAVY RAIN NEAR ZONE OF BEST LOW
LEVEL CONFLUENCE FINALLY SHIFTS NORTH OF THE AREA.
TEMPERATURES THROUGH THE ENTIRE SHORT TERM PERIOD WILL REMAIN
CLOSE TO OR EXCEEDING RECORD LEVELS...BOTH FOR VERY HIGH NIGHTTIME
LOWS...WHICH WILL REMAIN NEARLY 30F ABOVE SEASONAL NORMALS AND
AROUND 15F HIGHER THAN WHAT WOULD NORMALLY BE EXPECTED FOR A
DAYTIME HIGH TEMPERATURE...WITH DAYTIME HIGH TEMPERATURES AT LEAST
20F ABOVE SEASONAL NORMALS...AGAIN BREAKING RECORDS. REFER TO
CLIMATOLOGICAL SECTION FOR SPECIFICS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 245 PM EST WEDNESDAY...
NEXT WEEK WILL CONTINUED TO BE VERY WARM AND UNSETTLED. BY SUNDAY
MORNING A CLOSED 500MB LOW ACROSS TEXAS WILL BEGIN TO PIVOT
NORTHEAST TOWARDS THE CENTRAL GREAT LAKES BY TUESDAY. A SURFACE
FRONTAL BOUNDARY DRAPED FROM THE OHIO VALLEY TO THE SOUTHERN
PLAINS WILL MEANDER CLOSE TO THE REGION SUNDAY AND MONDAY KEEPING
A CHANCE OF SHOWERS. GREATEST THREAT FOR SHOWERS WILL BE TUESDAY
AS THE FRONT OCCLUDES AND SLOWLY PUSHES THROUGH OUR REGION AND
EVENTUALLY STALLING TO OUR SOUTHEAST ON WEDNESDAY.
SUNDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH 850MB TEMPS
APPROACHING +15C. TEMPS BACK OFF TO +5-10C MONDAY THROUGH THURSDAY
BEFORE THE COLDER AIR ARRIVES FRIDAY.
MODELS TEND TO AGREE THAT THE END OF THE WEEK WILL FEATURE A PUSH
OF MUCH COLDER AND DRIER AIR INTO THE REGION AS A SHORTWAVE DIGS
IN. DIFFERENCES EXIST AS TO HOW DEEP THAT PUSH OF COLDER AIR WILL
BE AND HOW MUCH IF ANY MOISTURE WILL BE AVAILABLE FOR ANY
POTENTIAL UPSLOPE PRECIP/CLOUDS LATE IN THE WEEK.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
AS OF 630 PM EST THURSDAY...
DUE TO AN OUTAGE AT KDAN EARLIER...AND JUST ONE OBSERVATION IN SINCE
21Z...WILL KEEP AMD NOT SKED IN THE TAF UNTIL PERSISTENT OBS
ARE COMING IN.
THERE WILL BE A BREAK IN SHOWERS THIS EVENING. LOW LVL MOISTURE IS
MORE PREVALENT EAST OF THE BLUE RIDGE WITH MORE MID/HIGH CLOUDS IN
THE WEST. THIS LACK OF LOWER CIGS IN THE WEST COULD ALLOW FOR MORE
FOG FORMATION THIS EVENING BEFORE DEEPER MOISTURE MOVES BACK IN
TOWARD MORNING. WILL VARY THE TAFS MORE TOWARD MVFR/VFR EARLY THEN
IFR/MVFR OVERNIGHT INTO FRIDAY MORNING. FRONTAL BOUNDARY STALLED
IN THE MTNS WILL START TO RETROGRADE WWD FRIDAY AFTERNOON AS HIGH
PRESSURE OVER THE WRN ATLANTIC BUILDS WEST. THIS WILL SET UP A
BETTER THREAT OF SHOWERS ALONG/WEST OF THE BLUE RIDGE.
MODELS VARY SO CONFIDENCE IS LOW TO MEDIUM THIS PERIOD.
.EXTENDED AVIATION DISCUSSION...
THE CHANCE OF SHOWERS AND SUB-VFR CONDITIONS WILL CONTINUE INTO
THE WEEKEND...BUT OVERALL LESS LIKELY TO PERSIST IN THE IFR OR
WORSE VALUES AS ATMOSPHERE WILL BE A LITTLE BETTER MIXED AND
FREQUENCY OF SHOWERS MUCH LESS WITH NO KEY FEATURES TO HELP LIFT
THE MOIST ATMOSPHERE.
BEYOND THIS WEEKEND...MODELS CONTINUE TO VARY BUT SHOWING BETTER
THREAT OF SHOWERS AGAIN BY LATE MONDAY INTO TUESDAY WITH VFR TO
IFR AT TIMES.
&&
.HYDROLOGY...
AS OF 320 PM EST THURSDAY...
AS ADVERTISED...VERY HIGH PRECIPITABLE WATER VALUES WERE BEING
ADVECTED INTO THE FORECAST AREA. THIS MOIST AIR MASS WILL REMAIN
IN THE REGION WELL INTO FRIDAY. UPPER DIFFLUENCE AND VORTICITY
ADVECTION WITH A SHORT WAVE TRACKING INTO THE SOUTHERN
APPALACHIANS WILL PROVIDE STRONG SYNOPTIC SCALE LIFT WHICH WILL BE
ENHANCED BY MODEST UPSLOPE ALONG THE BLUE RIDGE.
PRECIPITATION EFFICIENCY IS VERY HIGH TONIGHT AND FRIDAY. BASED
ON THESE EXPECTED RATES AND CONSIDERING THE LOCATIONS THAT HAVE
HAD SIGNIFICANT RAINFALL SO FAR THIS WEEK...A FLASH FLOOD WATCH
HAS BEEN EXTENDED FOR PARTS OF NORTHERN NORTH CAROLINA AND
SOUTHERN VIRGINIA INTO THE DAY FRIDAY. A NEW FLASH FLOOD WATCH
WILL BEGIN AT MIDNIGHT INTO FRIDAY EVENING FOR SOUTHWESTERN
VIRGINIA AND SOUTHEASTERN WEST VIRGINIA.
AS FOR THE MAIN STEM RIVERS...A FLOOD WARNING IS IN EFFECT FOR
THE DAN RIVER AT SOUTH BOSTON AND THE ROANOKE RIVER AT RANDOLPH.
&&
.CLIMATE...
AS OF 230 PM EST THURSDAY...
WE BROKE 3 RECORD HIGHS TODAY 12/24...DANVILLE...BLACKSBURG AND
BLUEFIELD. SEE RERRNK FOR DETAILS.
WITH THE CONTINUING VERY WARM AIRMASS IN PLACE FOR THE NEXT SEVERAL
DAYS... MANY DAILY MAX TEMPERATURE RECORDS AS WELL AS HIGH MIN
TEMPERATURE RECORDS ARE LIKELY TO BE SET. FOR REFERENCE...HERE ARE
RECORDS FOR OUR CLIMATE STATIONS FOR THE NEXT SEVERAL DAYS.
FRIDAY 12/25/2015
SITE MAXT YEAR HIMIN YEAR
KBLF 64 1982 55 1982
KDAN 76 1955 48 1988
KLYH 72 1982 57 1964
KROA 68 1982 54 1964
KRNK 68 1964 41 1972
SATURDAY 12/26/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 62 1987 -3 1983 16 1977 55 1982
KDAN 75 1982 2 1983 18 1983 57 1964
KLYH 72 1922 1 1983 22 1914 58 1964
KROA 70 1964 3 1980 23 1985 56 1982
KRNK 64 1982 -8 1985 9 1983 50 1982
SUNDAY 12/27/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 69 2008 9 1977 20 2010 52 1982
KDAN 77 1982 6 1983 27 1985 54 1964
KLYH 71 1971 0 1914 21 1925 50 1940
KROA 69 1984 -3 1914 25 1935 52 1940
KRNK 67 2008 -6 1985 20 1985 52 1964
MONDAY 12/28/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 67 1984 4 1977 20 1995 53 1984
KDAN 72 1971 13 1966 28 1950 54 2008
KLYH 76 1984 6 1977 26 1950 51 1959
KROA 75 1984 4 1925 25 1925 51 1984
KRNK 66 1984 6 1977 28 1995 42 1959
&&
.EQUIPMENT...
AS OF 625 PM EST THURSDAY...
THE DANVILLE AUTOMATED SURFACE OBSERVATION SYSTEM HAS BEEN OFFLINE THIS
THIS AFTERNOON. AN OBSERVATION CAME IN AT 6 PM...SO IT MAY BE
AVAILABLE AGAIN.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH FROM MIDNIGHT EST TONIGHT THROUGH FRIDAY
EVENING FOR VAZ007-010>014-017>020-022>024-033>035-
045>047.
FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR VAZ009-015-016-
032-043-044-058-059.
NC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH FROM MIDNIGHT EST TONIGHT THROUGH FRIDAY
EVENING FOR WVZ042>044-507-508.
&&
$$
SYNOPSIS...RCS
NEAR TERM...RCS/WP
SHORT TERM...WERT
LONG TERM...CF
AVIATION...RCS/WP
HYDROLOGY...WERT
CLIMATE...RCS
EQUIPMENT...RCS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
926 PM CST THU DEC 24 2015
.UPDATE...
SOUTHEAST WISCONSIN IS IN THE RIGHT ENTRANCE REGION OF THE STRONG
165 KNOT 250 MB UPPER JET MAX ACROSS THE LAKE HURON AREA.
THE 00Z NAM INCREASES THE UPPER DIVERGENCE DURING THE EARLY
MORNING HOURS. HOWEVER THE 700 MB MOTION IS DOWNWARD AND THE 700
MB RH DRIES AFTER MIDNIGHT.
THEREFORE EXPECT THE LIGHT SNOW AREA TO CONTINUE TO LIFT
NORTHEAST AWAY FROM THE FOND DU LAC AND SHEBOYGAN AREA...WITH NO
OTHER PRECIPITATION EXPECTED.
&&
.AVIATION/06Z TAFS/...
THE LIGHT SNOW THIS EVENING WILL BE EXITING TO THE NORTHEAST BY
MIDNIGHT. AREAS OF MVFR CIGS MAY AFFECT SOUTH CENTRAL WISCONSIN.
ALSO PATCHY MVFR FOG POSSIBLE.
OTHERWISE VFR CONDITIONS EXPECTED FRIDAY UNDER HIGH PRESSURE.
&&
.PREV DISCUSSION... /ISSUED 315 PM CST THU DEC 23 2015/
TONIGHT AND FRIDAY - CONFIDENCE...MEDIUM.
MODELS GENERALLY IN GOOD AGREEMENT IN DIMINISHING AREA OF UPSTREAM
SNOW AS IT APPROACHES THE FROM THE SOUTHWEST BY LATE AFTERNOON. MOST
MODELS INDICATE BEST CHANCE FOR ANY VERY LIGHT ACCUMULATIONS THIS
EVENING WOULD BE ACROSS THE NORTHWEST FORECAST AREA AS A SHORTWAVE
PUSHES THROUGH. LATEST NAM AND HRRR ARE SHOWING SOME ADDITIONAL
DEVELOPMENT LATE EVENING...THOUGH DEEPER MOISTURE IS DEPARTING AT
THAT TIME. COULD BE SOME DRIZZLE MIXED IN THERE IF SATURATION IS NOT
DEEP ENOUGH FOR ICE CRYSTAL FORMATION. ANY LINGERING PRECIP SHOULD
EXIT THE EAST BY AROUND 3 AM...WITH DECREASING CLOUDS TOWARD
DAYBREAK AS HIGH PRESSURE BUILDS INTO THE AREA.
HIGH PRESSURE WILL THEN BRING DRY WEATHER AND A FAIR AMOUNT OF
SUNSHINE FRIDAY...WITH HIGH TEMPERATURES REMAINING ABOVE NORMAL IN
THE UPPER 30S TO LOW 40S.
FRIDAY NIGHT THROUGH SUNDAY - FORECAST CONFIDENCE...LOW TO MEDIUM.
DRIER EASTERLY FLOW AND LINGERING SHORT WAVE RIDGING WILL SLOW DOWN
THREAT OF LIGHT PRECIPITATION SPREADING BACK INTO SRN WI. HENCE WL
REMOVE POPS FOR MOST OF FRIDAY NIGHT...BUT KEEP SMALL CHANCE IN THE
WEST WELL AFTER 06Z.
OVER THE NEXT 24 HOURS...UPPER JET AXIS SHIFTS FROM OVER SRN WI TO
NORTHERN WI IN RESPONSE TO AMPLIFYING UPSTREAM LONG-WAVE TROFFING.
SRN WI WILL REMAIN BETWEEN TWO ACTION AREAS ON SATURDAY. ENHANCED
SYNOPTIC FORCING FROM LEFT ENTRANCE REGION OF UPPER JET WL FOCUS TO
THE NORTHWEST OF CWA ACROSS MORE OF SRN MN INTO CENTRAL/NRN WI. IN
ADDITION...THIS AREA WILL EXPERIENCE BETTER LOW LEVEL CONVERGENCE
ALONG TIGHTENING BAROCLINIC ZONE. MEANWHILE...WELL TO THE
SOUTH...STRONG FRONTAL BOUNDARY WILL REMAIN ACTIVE FROM THE OHIO
VALLEY INTO THE CENTRAL MS VALLEY REGION. WEAK LAYER Q-VECTOR
CONVERGENCE DOES PASS ACROSS SRN WI ON SAT AND EXITS THE AREA SAT
NGT. WL CONTINUE HIGHER CHANCE TO LIKELY POPS IN NORTHWEST CWA FOR
LATER FRIDAY NIGHT INTO SATURDAY AS BOTH GFS AND NAM SHOWING
MODERATE ISENTROPIC OMEGA ON 300 THETA SURFACE BRUSHING THIS AREA.
CONDENSATION PRESSURE DEFICITS DECREASE TO LESS THAN 10 MB DURING
THIS TIME. FORECAST SOUNDINGS AND TOP-DOWN APPROACH SHOW POTENTIAL
FOR A PERIOD OF -SN AND -IP INITIALLY...CHANGING OVER TO MOSTLY -RA
IN THE AFTN. 85H TEMPS DROP 10C BY SUN MRNG AS COLDER AIR SETTLES
OVER SRN WI. SOME -RA OR -SN IS POSSIBLE SAT NGT AS REMNANTS OF
UPSTREAM SHORT WAVE TROF MOVE THRU ERN AND SRN WI. BUILDING SHORT
WAVE RIDGING WL RESULT IN MOSTLY DRY AND COLDER CONDITIONS TO FINISH
OFF THE HOLIDAY WEEKEND. WL NEED TO KEEP ONE EYE ON LINGERING LOW
LEVEL MOISTURE AND POTENTIAL LAKE EFFECT LIGHT RAIN OR SNOW SHOWERS
AS DELTA-T INCREASES TO AROUND 11C BEFORE LOW LEVEL WINDS WEAKEN AND
BACK MORE TO THE NORTH. GFS AND NAM FOCUS LOW LEVEL WINDS MORE INTO
NE IL SUN MRNG HOWEVER SO KEPT SUN MRNG DRY ALONG THE LAKE FOR NOW.
EXTENDED PERIOD...
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE - INITIALLY HIGH
TRENDING TO LOW.
QUIET WEATHER IS EXPECTED TO START THE EXTENDED PERIOD AS THE SHORT
WAVE RIDGING THAT WILL HAVE BUILT INTO THE WESTERN GTLAKES LATER
SUNDAY LINGERS OVER THE WESTERN GTLAKES INTO MONDAY. THE COLDER
TEMPERATURES WILL PERSIST THROUGH THE EXTENDED PERIOD...BUT WILL
STILL BE ABOVE NORMAL FOR LATE DEC. THE QUIETER WEATHER LOOKS TO BE
SHORT-LIVED AS MEDIUM RANGE GUIDANCE IN GOOD AGREEMENT ON CARRYING
SOUTHERN PLAINS SHORT WAVE ON NORTHERLY PATH INTO THE VICINITY OF
THE NRN IL/IN REGION BY 12Z/TUE. HOWEVER ECMWF AND GFS DIVERGE ON
PATH OF WEATHER SYSTEM. ECMWF HAD BEEN TRENDING MORE WEST AND
WARMER OVER EARLIER MODEL RUNS...HOWEVER NEW 12Z DETERMINISTIC RUN
NOW TRENDING FARTHER EAST AND COLDER WITH THIS SYSTEM. CRITICAL
THICKNESSES SHOWING POTENTIAL FOR ICING MON NGT WITH THIS SOLUTION.
GFS AND GEM-NH SHOWING BETTER RUN TO RUN CONSISTENCY WITH COLDER
SOLUTION AND ARE TRENDING FARTHER SOUTH AND EAST...MORE TOWARD NRN
IN WITH LESS EFFECT ON SRN WI. MREF ENSEMBLE BASED ON GFS SHOWS
CONSIDERABLE VARIABILITY WITH SOME OF THE SOLUTIONS TRENDING FARTHER
WEST. WPC BLENDED FIELDS FAVOR 00Z DETERMINISTIC ECMWF AND ECMWF
BLEND WHILE NEW 12Z NH-GEM IS TRENDING TOWARD DRIER GFS. HENCE ALOT
OF UNCERTAINTY AT THIS POINT AND LOW CONFIDENCE IN SOLUTIONS FOR
THIS EARLY WEEK SYSTEM. FOR NOW WL CONTINUE LIKELY WORDING FOR SNOW
IN THE SOUTHEAST CWA WITH A CHANCE FOR SOME SLEET OR RAIN IN THE FAR
SOUTHEAST. NEED BETTER AGREEMENT BEFORE HITTING FREEZING RAIN
THREAT HARDER AT THIS POINT. WL CONTINUE POTENTIAL SNOWFALL
AND MIX MENTION IN HWO.
TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE - MEDIUM.
LOOKS LIKE UNSETTLED CONDITIONS WILL CONTINUE THROUGH MID-WEEK AND
THE END OF THE EXTENDED PERIOD. LINGERING UPSTREAM TROF OVER UPPER
MIDWEST LOOKS TO SEND SEVERAL WEAK SHORT WAVES ACROSS THE WESTERN
GTLAKES DURING THE PERIOD. COLDER...MORE SEASONAL CONDITIONS SHOULD
SETTLE INTO THE REGION EARLY NEXT WEEK SO MAY BE ABLE TO FINALLY
BUILD UP SOME SNOW COVER.
AVIATION/00Z TAFS/...
WILL LIKELY SEE A LITTLE SNOW THIS EVENING...MAINLY ACROSS THE
NORTHWEST HALF OF THE FORECAST AREA AS A SHORTWAVE MOVES THROUGH THE
AREA. SNOW TOTALS LOOK LIKE A DUSTING TO A COUPLE TENTHS OF AN INCH
AT BEST. LATEST HRRR AND NAM DO SHOW SOME ADDITIONAL DEVELOPMENT
FARTHER SOUTHEAST BY LATE EVENING...POSSIBLY MIXED WITH DRIZZLE AS
DEEPER MOISTURE IS LOST. ANY LINGERING PRECIP SHOULD EXIT THE EAST
BY AROUND 09Z. THE SHORTWAVE WILL LIKELY BRING SOME LOWER CIGS FOR A
TIME...WITH VFR CONDITIONS RETURNING FOR FRIDAY UNDER HIGH PRESSURE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
&&
$$
UPDATE...HENTZ
TONIGHT/FRIDAY AND AVIATION/MARINE...DDV
FRIDAY NIGHT THROUGH THURSDAY...MBK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
552 PM CST THU DEC 24 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 327 PM CST THU DEC 24 2015
LINGERING GUSTY WINDS WILL END DURING THE REST OF THE AFTERNOON
AS THE DEEP STORM SYSTEM WHICH PRODUCED STRONG WINDS OVERNIGHT
MOVES FURTHER NORTHEAST.
WITH THE EXCEPTION OF SOME HOLES IN THE CLOUD COVER FOR AREAS EAST
OF THE FOX RIVER EARLY THIS AFTERNOON...CLOUDS WERE PERSISTENT
ACROSS THE AREA. WHERE LOW LEVEL CLOUDS HAVE SCOURED OVER EAST
CENTRAL WISCONSIN...LOWERING MID LEVEL CLOUDS WILL BE ON THE
INCREASE THIS AFTERNOON AND EVENING AS A WEAK SHORT WAVE TRACKS
FROM IOWA TO SOUTHERN WISCONSIN. THE MODELS ARE IN SOME AGREEMENT
WITH THE NORTHERN FRINGE OF THE LIGHT SNOW BRUSHING OVER PARTS OF
CENTRAL AND EAST CENTRAL WISCONSIN THIS EVENING BEFORE DEPARTING
JUST AFTER MIDNIGHT. HRRR DIMINISHES THIS AREA OF LIGHT SNOW WHILE
WORKING NORTHWARD SO WILL MAINLY GO WITH HIGHER END CHC POPS SOUTH
OF HIGHWAY 10.
SURFACE HIGH PRESSURE REGION AND UPPER REGION BUILDS INTO THE AREA
FRIDAY FOR A QUIET XMAS DAY.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 327 PM CST THU DEC 24 2015
THE MAIN CONCERNS DURING THIS PART OF THE FORECAST ARE A COUPLE OF
SYSTEMS WITH THE POTENTIAL TO PRODUCE SEVERAL INCHES OF SNOWFALL
IN THE FORECAST AREA. THE FIRST ARRIVES LATE FRIDAY NIGHT AND THE
NEXT LOOKS TO BE EARLY IN THE UPCOMING WORK WEEK.
MODELS ONCE AGAIN SHOWED A STRONG UPPER JET STREAK NORTH OF
WISCONSIN. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE JET WILL
ASSIST AN APPROACHING MID LEVEL SHORT WAVE TROUGH IN DEVELOPING
SNOW ACROSS NORTHERN WISCONSIN FRIDAY NIGHT AND SATURDAY. HIGHEST
QPF VALUES WERE FORECAST IN THE NORTH AND THERE MAY BE SEVERAL
INCHES OF SNOW BEFORE THINGS WIND DOWN SATURDAY EVENING. MOST OF
THE 12Z MODELS SHOWED ONE LARGE AREA OF QPF DEVELOPING...THE NAM
KEPT TWO SEPARATE AREAS...AS A SURFACE LOW MOVING ALONG A COLD
FRONT ENTERS THE REGION. PRECIPITATION AMOUNTS SHOULD BE LIGHTER
BETWEEN THE TWO MAXIMA AND SOME WILL FALL AS RAIN IN PARTS OF
EASTERN WISCONSIN. SO...SNOWFALL NUMBERS ARE RATHER QUESTIONABLE
IN CENTRAL AND EASTERN WISCONSIN. SURFACE HIGH PRESSURE BUILDING
INTO THE AREA WILL KEEP A CHANCE FOR LAKE EFFECT SNOW SHOWERS IN
FAR NORTH CENTRAL WISCONSIN THROUGH AT LEAST SUNDAY.
SURFACE AND 500MB LOWS MOVING FROM THE PLAINS TO THE GREAT LAKES
REGION COULD BRING SIGNIFICANT SNOWFALL TO THE AREA...BUT THERE IS
TOO MUCH DISAGREEMENT AMONG THE MODELS TO GO WITH ANYTHING HIGHER
THAN A CHANCE FOR SNOW ON MONDAY NIGHT AND TUESDAY. THE 12Z
CANADIAN-NH BRINGS LITTLE OR NO PRECIPITATION TO THE AREA AT
ALL...WHILE THE ECMWF HAD MORE THAN 0.50 INCH OF QPF IN THE
SOUTHERN PART OF THE AREA. THE GFS LOOKED MORE SIMILAR TO THE
CANADIAN THAN TO THE EC. WILL HAVE TO KEEP A CLOSE WATCH ON THE
SYSTEM.
TEMPERATURES WILL BE ABOVE NORMAL FOR THIS TIME OF YEAR...BUT NOT
NEARLY AS WARM AS THEY HAVE BEEN IN THE RECENTLY.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 539 PM CST THU DEC 24 2015
MVFR CIGS COVERED MOST OF THE FORECAST AREA EARLY THIS EVG...WITH
THE EXCEPT OF PATCHY IFR CIGS IN NC WI...AND VFR CONDITIONS IN EC
WI. SOME LIGHT SNOW ASSOCIATED WITH AN UPPER LEVEL JET STREAK WAS
APPROACHING CENTRAL WI.
EXPECT LIGHT SNOW AND FLURRIES TO DEVELOP OVER MOST OF C/EC WI
MID-EVENING...AND LINGER INTO THE EARLY MORNING HOURS. HAVE ADDED
2-4 HOUR TEMPO GROUPS FOR LIGHT SNOW...EXCEPT AT RHI...WHICH WILL
BE TOO FAR REMOVED FROM MOISTURE/LIFT. EXPECT MAINLY MVFR
CONDITIONS...THOUGH VSBYS AT ISW...Y50...PCZ AND OSH COULD DROP
TO IFR FOR A FEW HOURS.
CONFIDENCE IN LOW CLOUDS TRENDS IS LOW FOR TOMORROW MORNING...
AS MAV GUIDANCE SHOWS CLEARING OCCURRING LATE TONIGHT...AND
MET GUIDANCE HANGS ONTO LOW CLOUDS INTO THE MID-LATE MORNING
ON CHRISTMAS DAY. CLEARING THIS TIME OF YEAR IS NOT A CERTAINTY...
BUT WITH HIGH PRESSURE BUILDING IN...AT LEAST PARTIAL CLEARING
SEEMS PLAUSIBLE. WILL USE A COMPROMISE TIMING BETWEEN THE MAV/MET
GUIDANCE WITH THIS SET OF TAFS...AND TAKE ANOTHER LOOK FOR THE 06Z
TAFS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TDH
LONG TERM......MG
AVIATION.......KIECKBUSCH
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 309 PM CST WED DEC 23 2015
PLENTY OF FORECAST CHALLENGES NEXT 24 HOURS CONCERNING WITH GUST
POTENTIAL AND AMOUNT OF RAINFALL AND RAINFALL RATES WHICH MAY
IMPACT ANY LINGERING RIVER FLOOD PROBLEMS AS WELL AS PRODUCE ANY
SMALL STREAM URBAN FLOODING ISSUES. SEE THE HYDROLOGY SECTION
BELOW FOR THE LATEST DETAIL ON FLOODING ISSUES. OTHER ISSUES
CONCERN CHANGE OVER TO SNOW TONIGHT.
A STRONG SHORT WAVE LIFTS NORTHEAST OVER THE GREAT LAKES REGION
THROUGH TONIGHT. AN ASSOCIATED SURFACE LOW WILL TRACK FROM IOWA
LATE THIS AFTERNOON TO CENTRAL UPPER MICHIGAN AROUND MIDNIGHT AND
DEEPEN. THE LOW WILL ALSO A DRAG WARM FRONT OVER NORTHEAST
WISCONSIN THIS AFTERNOON INTO THIS EVENING. MILDER AIR SPREADING
INTO EAST CENTRAL AND FAR NORTHEAST WISCONSIN WILL ALLOW A VERY
MILD AIR MASS WITH POSSIBLE RECORD HIGHS TO INVADE THE AREA.
HIGHEST TOTAL TOTALS NUMBERS IN THE LOWER 50S MID EVENING AS PER
GRB BUFKIT DATA. THIS WILL ALSO RESULT IN A MORE UNSTABLE AIR
MASS AND MAY PROMOTE BETTER MIXING OF STRONG WINDS TO THE
SURFACE...ESPECIALLY WITH ANY CONVECTION. HRRR PROGGED DEVELOPMENT
OF THIS CONVECTION OF CONCERN ALONG AND AHEAD OF THE FRONT OVER
NORTHERN MO AND SOUTHERN IOWA AND SO FAR IS VERIFYING. THIS NEXT
ROUND IS PROGGED TO SWEEP OVER THE AREA THIS EVENING.
PROBLEM 2 WITH THE WINDS OCCUR LATE TONIGHT AS THE DEEPENING LOW
PRESSURE DEPARTS NORTHEAST AND LEAVES A STRONG PRESSURE GRADIENT
OVER MUCH OF THE STATE. A STRONG PRESSURE CHANGE COUPLET SLIDES
OVER NORTHEAST WISCONSIN IN THE WAKE OF THE SURFACE LOW. WILL
CONTINUE WITH THE WIND ADVISORY AND WILL ISSUE FOR DOOR DUE TO THE
WESTERLY COMPONENT. ITS POSSIBLE THE HIGH WIND ADVISORIES AND
WARNINGS MAY NEED TO BE EXPANDED DEPENDING ON THE LOW PRESSURE
TRACK.
PCPN TYPE INITIALLY NOT AN ISSUE BUT COULD SEE SOME HAIL OR
GRAUPEL WITH ANY CONVECTION THIS EVENING. LATER EVENING INTO THE
MORNING...COLDER AIR POURING IN WILL CHANGE THE PCPN TYPE TO
SNOW. WHILE SNOW RANGES MOSTLY IN THE 2-4 RANGES FOR NC WI...THE
SNOW WIND COMBO WARRANTS AN ADVISORY LATER TONIGHT. RADAR SOUTHERN
LOOP SUGGESTS REACHING NC WI AND CHANGEOVER AND ISSUE. BUT DID
NOTICE SOME THUNDER WITH THE SURFACE LOW OVER IOWA.
SYSTEM GRADUALLY DEPARTS THURSDAY WITH DIMINISHING WINDS IN THE
MORNING. TEMPERATURES NEAR STEADY ON THURSDAY.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 309 PM CST WED DEC 23 2015
AMPLIFIED MEAN FLOW TO REMAIN INTACT THRU THE END OF THE WORK WEEK
WITH AN ERN PACIFIC UPR RDG...WRN CONUS UPR TROF AND BERMUDA UPR
RDG. THE UPR TROF IS FCST TO CLOSE OFF INTO AN UPR LOW OVER WEST
TX THIS WEEKEND BEFORE LIFTING NE INTO THE GREAT LAKES EARLY NEXT
WEEK. PCPN CHCS WL BE FOCUSED FRI NGT/SAT ASSOCIATED WITH A TIGHT
BAROCLINIC ZONE/JET ENERGY AND MON NGT/TUE WITH THE UPR LOW/
ASSOCIATED SFC LOW. PCPN TYPE ISSUES WL ALSO BE A PROBLEM WITH
BOTH OF THESE SYSTEMS AS TEMPS FLUCTUATE BELOW FREEZING AT NGT AND
RISE ABOVE FREEZING IN PLACES DURING THE DAY. THERE IS SNOW
ACCUMULATION POTENTIAL FOR CNTRL/NRN WI FRI NGT AND OVER THE
ENTIRE AREA MON NGT/TUE.
A WEAK AREA OF HI PRES IS FCST TO APPROACH SRN SECTIONS OF THE
GREAT LAKES THU NGT AND SHOULD KEEP THE FCST AREA DRY. IT MAY TAKE
MOST OF THE NGT TO TRY AND SCOUR OUT LINGERING LOW/MID-LEVEL
MOISTURE...THUS PARTLY TO MOSTLY CLOUDY SKIES SHOULD SUFFICE. MIN
TEMPS TO RANGE FROM THE MID TO UPR TEENS NORTH...LWR 20S CNTRL...
AND MID TO UPR 20S E-CNTRL WI. THESE DRY CONDITIONS ARE EXPECTED
TO PERSIST THRU CHRISTMAS DAY AS THE SFC HI SLIDES EAST TOWARD THE
ERN GREAT LAKES. UNDER PARTLY CLOUDY SKIES AND RELATIVELY LIGHT
WINDS...LOOK FOR MAX TEMPS TO REACH THE LWR TO MID 30S NORTH...
MID TO UPR 30S SOUTH.
FCST CONFIDENCE DROPS RATHER QUICKLY LATE FRI NGT INTO SAT AS AN
UPR TROF DEEPENS OVER THE ROCKIES...INDIVIDUAL SHORTWAVES EJECT
OUT OF THIS TROF NEWD THRU THE CNTRL CONUS...A STALLED FRONTAL
BOUNDARY TO OUR SOUTH BECOMES MORE ACTIVE AND GULF MOISTURE LIFTS
NORTH ALONG THIS FRONTAL BOUNDARY TOWARD THE GREAT LAKES. MODELS
BRING THE LEADING EDGE OF PCPN INTO NE WI LATE FRI NGT WHEN TEMPS
WL BE COLD ENUF TO ALLOW PCPN TO FALL AS ALL SNOW. THE ISSUES FOR
SAT ARE WHERE THE HIGHEST QPF WL FALL AND WHAT THE PCPN TYPE WL
BE. THIS IS WHERE THE MODELS DIFFER AS THE GFS/ECMWF FOCUS THE
HEAVIER PCPN TO THE NORTH AND ALLOW FOR WARMER AIR TO LIFT FARTHER
NORTH INTO WI...THUS A MIXED PCPN EVENT FOR CNTRL/E-CNTRL WI WITH
SNOW NORTH. THE GEM IS FARTHEST SOUTH WITH THE HEAVIER PCPN (SRN
WI) AND COOLER AIR...THUS KEEPING ALL OUR PCPN AS ALL SNOW. THE
BETTER FRONTOGENETICAL FORCING SIGNAL AND LOCATION OF THE BEST
LIFT FROM THE RIGHT ENTRANCE REGION OF THE UPR JET FAVOR NRN WI
WITH THE HIGHER QPF...THUS WL CONT THE MENTION OF SNOW NORTH AND
SNOW BECOMING MIXED WITH RAIN FOR CNTRL/E-CNTRL WI. POTENTIAL SNOW
ACCUMULATION OF 3-5" IS POSSIBLE OVER THE NORTH FRI NGT INTO
SAT...BUT ANY WAVERING ON THE STRONGER LIFT/FORCING COUDL ALTER
THESE VALUES.
AS THE STRONGER DYNAMICS SHIFT TO THE EAST SAT NGT...MODELS
INDICATE CAA TO TAKE OVER ACROSS WI...THUS ANY LINGERING RAIN OVER
CNTRL OR E-CNTRL WI WL TRANSITION TO ALL SNOW. DO NOT ANTICIPATE
MUCH (IF ANY) ADDITIONAL ACCUMULATION SAT NGT AS MOST OF THE
MOISTURE TO HAVE BEEN SHUNTED EAST. A STRONG AREA OF HI PRES IS
FCST TO BUILD ACROSS THE UPR MS VALLEY ON SUNDAY AND SEND ENUF DRY
AIR INTO WI TO ALLOW SKIES TO BECOME AT LEAST PARTLY CLOUDY.
DESPITE THE CAA AND NORTH WINDS AT 5 TO 15 MPH...MAX TEMPS ARE
FCST TO REMAIN ABOVE NORMAL ON SUNDAY BY AROUND 5 DEGS (MID 20S
N-CNTRL TO LWR 30S E-CNTRL WI).
THE CORE OF THIS STRONG HI PRES IS PROGGED TO MOVE ACROSS WRN
ONTARIO SUNDAY NGT AND VEER THE WINDS TO THE NE. WL HAVE TO WATCH
FOR POTENTIAL OF LK EFFECT SNOW SHWRS FROM LK MI AS TEMPS/DELTA-T
VALUES WOULD SUPPORT THE DEVELOPMENT OF LIGHT SNOW. ONE NEGATIVE
IS THAT THE WINDS CONT TO VEER THRU THE NGT (FROM NORTH TO
E-NE)...THUS IT MAY PROVE DIFFICULT FOR SNOW BANDS TO FOCUS ON ANY
ONE PARTICULAR AREA. OTHERWISE...THE OTHER BIG STORY WL BE THE
APPROACH OF ANOTHER STRONG AREA OF LOW PRES/CLOSED UPR LOW INTO
THE MID-MS VALLEY ON MON. LATEST THINKING IS THAT THERE WL BE ENUF
DRY AIR ON GUSTY EAST WINDS FROM ONTARIO HI PRES TO DELAY THE
ONSET OF ANY PCPN INTO NE WI ON MON. HAVE REDUCED POPS AND WOULD
EXPECT ALMOST A COMPLETELY DRY DAY FOR MON WITH MAX TEMPS IN THE
UPR 20S TO LWR 30S.
MODELS CONT TO DIFFER WITH THE TIMING/EVENTUAL TRACK OF THIS
STRONG SYSTEM MON NGT INTO TUE WITH THE GFS/GEM FAVORING A
QUICKER/FARTHER EAST TRACK VERSUS THE SLOWER/FARTHER WEST TRACK OF
THE ECMWF. THE GFS/GEM SOLUTION WOULD PROVIDE A QUICK-HITTING SNOW
EVENT FOR MAINLY THE SE HALF OF WI MON NGT BEFORE PULLING AWAY ON
TUE. THE ECMWF SOLUTION WOULD BRING A SWATH OF SNOW ACROSS ALL
OF NE WI MON NGT BEFORE MIXING IN RAIN OVER CNTRL/E-CNTRL WI ON
TUE WITH ADDITIONAL SNOWS FOR NRN WI. IF THE ECMWF SOLUTION
PREVAILS...WE WOULD BE LOOKING AT HEADLINES FOR SNOW...HOWEVER
THERE IS TOO MUCH UNCERTAINTY YET SO HAVE FOLLOWED A MODEL BLEND
FOR NOW WITH HIGHER CHC POPS IN THE FCST FOR BOTH MON NGT AND TUE.
EVEN GOING INTO WED...THERE IS MODEL DISAGREEMENT WITH RESPECT TO
THE TRACK OF THE SECONDARY/WEAKER UPR LOW THAT WOULD LIFT NE INTO
THE REGION. SINCE MODELS ARE INCONSISTENT WITH THIS
FEATURE...PREFER TO KEEP THE FCST DRY FOR NOW...BUT WOULD EXPECT
SOME SMALL POPS TO BE ADDED AS WE GET CLOSER TO WED.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1110 AM CST WED DEC 23 2015
WIDESPREAD IFR/LIFR CONDITIONS TODAY INTO TONIGHT AS RAIN
OVERSPREADS THE AREA. THERE IS A CHANCE FOR THUNDERSTORMS LATER
AFTERNOON INTO THIS EVENING. OF MORE OF A CONCERN...LLWS
CONDITIONS EXPECTED THIS AFTERNOON INTO TONIGHT. SOME OF THESE
STRONG WINDS ALOFT COULD MIX DOWN TO THE SURFACE TONIGHT TO
PRODUCE WIND GUSTS TO 45 KTS...MAINLY OVER THE EAST HALF OF THE
STATE.
&&
.MARINE...
ISSUED AT 309 PM CST WED DEC 23 2015
HIGH-END GALES ARE STILL LIKELY WITH THIS STORM....BUT WILL
MENTION STORM FORCE WIND GUSTS. IN ADDITION WILL ALSO MENTION A
PERIOD OF FOG THOUGH THE EVENING HOURS.
&&
.HYDROLOGY...
ISSUED AT 309 PM CST WED DEC 23 2015
MOST RIVERS HAVE RECOVERED FROM THE HEAVY RAINS OVER A WEEK
AGO...EXCEPT FOR THE LOW LYING AREAS ALONG THE WOLF RIVER SOUTH OF
SHAWANO TO LAKE POYGAN. WITH THIS RAINFALL EXPECTED TO BE IN A
SHORTER TIME FRAME...AN INCH OF RAIN COULD PRODUCE ENOUGH RUN OFF
FOR SOME MINOR URBAN SMALL STREAM FLOODING. THIS WOLF RIVER LEVELS
MAY HOLD STEADY FOR A FEW MORE DAYS WITH THIS ADDITIONAL RAINFALL.
BUT LATEST RADAR TRENDS SUGGEST SOME DRY SLOTTING AS AN AREA OF
ELEVATED CONVECTION IS SWEEPING NORTHEAST OF THE AREA...WITH THE
NEXT ROUND OF CONVECTION APPROACHING FROM IOWA. AS A RESULT RAIN
AMOUNTS TO BE LESS ROUGHLY FORM 0.30 TO 0.50. SEE
WEATHER.GOV/AHPS FOR AVAILABLE FORECASTS FOR NORTHEAST WISCONSIN
RIVERS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 PM THIS EVENING TO NOON CST THURSDAY FOR
WIZ020-021-031-037>040-045-048>050-073-074.
HIGH WIND WARNING FROM 10 PM THIS EVENING TO NOON CST THURSDAY
FOR WIZ022.
WINTER WEATHER ADVISORY FROM 8 PM THIS EVENING TO 4 AM CST
THURSDAY FOR WIZ005-010.
&&
$$
SHORT TERM.....TDH
LONG TERM......AK
AVIATION.......TDH
MARINE.........TDH
HYDROLOGY......TDH
AREA FORECAST DISCUSSION...UPDATED
NWS CHEYENNE WY
1058 PM MST TUE DEC 22 2015
.UPDATE...ISSUED FOR 06Z AVIATION FORECAST PACKAGE DISCUSSION
BELOW.
PREVIOUS UPDATE ISSUED AT 758 PM MST TUE DEC 22 2015...
ALLOWED WINTER WEATHER ADVISORIES FOR THE ELK MOUNTAIN...
ARLINGTON...AND SOUTHWESTERN CARBON COUNTY TO EXPIRE EARLIER THIS
EVENING GIVEN MOST OF ANY SIGNIFICANT SNOWFALL WILL BE TO THE EAST
AND WINDS HAVE RELAXED TO WHERE BLOWING SNOW ISSUES ARE NOT
EXPECTED TO BE SIGNIFICANT. WYDOT STILL REPORTS SOME ROADS AS
SLICK OR SLICK IN SPOTS SO MOTORISTS WILL NEED TO BE ADVISED TO
CHECK THE LATEST ROAD CONDITIONS BEFORE HEADING OUT. WINTER STORM
WARNINGS REMAIN POSTED FOR MORE HEAVY SNOW POTENTIAL THROUGH
TOMORROW IN THE SIERRA MADRE AND SNOWY MOUNTAIN RANGES WEST OF
LARAMIE.
BAND OF LIGHT SNOW EXTENDS FROM NORTHEASTERN COLORADO INTO THE
SOUTHERN NEBRASKA PANHANDLE. A LOT OF THE RADAR RETURNS MAY NOT BE
MAKING IT TO THE SURFACE...AND THE DEEPER MOISTURE AND HIGHER
CLOUDTOP SIGNATURES ARE MOVING OUT EAST OF CHEYENNE WITH MOST OF
ANY LIGHT TO MODERATE SNOW EXPECTED TO AFFECT THE SOUTHERN
NEBRASKA PANHANDLE...AND RIGHT NOW IT DOESN`T LOOK LIKE THEY WILL
GET MUCH IN THE WAY OF NEW SNOW THIS EVENING OR OVERNIGHT GIVEN
OBSERVATIONS AND RADAR AND SATELLITE RETURNS. THEREFORE WILL KEEP
A CHANCE OF SNOW GOING SOUTHERN NEBRASKA PANHANDLE TO
CHEYENNE...BUT IT ISN`T LOOKING LIKE A FEW INCHES WILL PAN OUT IN
CHEYENNE...MAYBE AN INCH OR SO SIDNEY (LIKELY AT MOST) IF WE GET
ANOTHER BAND DEVELOP TO THE SOUTHWEST AND MOVE ACROSS THEM LATE
TONIGHT.
BASED ON THE CHANCES OF SNOW WE CURRENTLY HAVE ADVERTISED OUT WEST
ACROSS PARTS OF CARBON COUNTY AND ALONG I-80 FROM RAWLINS TO
LARAMIE FOR TOMORROW...WE MAY HAVE TO POST WINTER WEATHER
ADVISORIES AGAIN ON THE EARLY MORNING SHIFT FOR TOMORROW IF NEW
SNOW AMOUNTS COME IN A BIT HIGHER ON OVERNIGHT MODEL RUNS
RESULTING IN A HIGHER POTENTIAL FOR SIGNIFICANT TRAVEL IMPACTS.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 214 PM MST TUE DEC 22 2015
PRIMARY FORECAST CONCERN FOR THE SHORT TERM IS THE POTENTIAL FOR
SNOWFALL ACROSS THE EXTREME SE WYOMING PLAINS EXTENDING INTO THE
SOUTHERN NEBRASKA PANHANDLE THIS EVENING AND TONIGHT. EVERYTHING
ELSE APPEARS ON TRACK...WITH CURRENT KCYS RADAR LOOP SHOWING
SNOWFALL CONTINUING OVER THE MOUNTAINS. SNOTEL OBSERVATIONS ACROSS
THE SIERRA MADRE RANGE SHOW SOME IMPRESSIVE 36 HOUR SNOW
TOTALS...WITH TWO LOCATIONS NEAR BATTLE MOUNTAIN PASS ESTIMATING
BETWEEN 34 TO 42 INCHES OF SNOW SINCE LATE SUNDAY NIGHT. MORE SNOW
IS EXPECTED TONIGHT AND WEDNESDAY...SO THESE TOTALS WILL LIKELY GO
OVER 4 FEET IN A FEW LOCATIONS. MUCH LESS SNOW WAS OBSERVED OVER
THE SNOWY RANGE WITH ONLY ONE LOCATION ABOVE ONE FOOT OF TOTAL
ACCUMULATION. WILL CONTINUE THE WINTER WEATHER ADVISORIES FOR A
FEW OF THE LOWER ELEVATIONS OF CARBON COUNTY INTO THIS EVENING
WITH SOME ADDITIONAL SNOW AND BLOWING SNOW ALONG AND SOUTH OF I80.
ATTENTION THEN SHIFTS EASTWARD TOWARDS LARAMIE...THE CHEYENNE
AREA...AND ACROSS THE SOUTHERN NE PANHANDLE ALONG I80. MODELS ARE
IN PRETTY GOOD AGREEMENT SHOWING AN AREA OF RAPID FRONTOGENESIS
THIS EVENING JUST SOUTH OF THE COLORADO BORDER. MODELS SHOW A
WEAK WAVE OF LOW PRESSURE DEVELOPING ALONG THE FRONT THIS
EVENING...WHICH IS CURRENTLY NEAR DENVER AND STRETCHES EASTWARD
OVER THE PLAINS NEAR I-70 OVER EASTERN COLORADO. THIS FEATURE
APPEARS TO BE FAST MOVING BUT POTENT...WITH EVEN THE HRRR AND NAM
SHOWING SOME MODERATE SNOW FROM THE I80 SUMMIT EASTWARD INTO
THE SOUTHERN NE PANHANDLE. TYPICALLY...GOOD MODEL AGREEMENT WOULD
INCREASE OVERALL CONFIDENCE 6 TO 12 HOURS OUT...BUT THE ISSUE IS
NO MODELS WAS SHOWING THIS FEATURE YESTERDAY. FOR NOW...INCREASED
POP TO 50 PERCENT ALONG THE I80 CORRIDOR INTO SIDNEY NEBRASKA.
WORDED FORECAST FOR OCCASIONAL SNOW AND 1 TO 2 INCHES OF SNOW
ACCUMULATION FOR NOW EVEN THOUGH THE NAM AND GEM ARE A BIT HIGHER.
WITH WESTERLY FLOW JUST OFF THE SURFACE AND RELATIVELY LOW
DEWPOINTS...CONCERNED THERE IS TOO MUCH DRY AIR TO PRODUCE MUCH
SNOWFALL. THE FRONT WILL QUICKLY PUSH SOUTH AND EAST LATE TONIGHT.
ANOTHER ROUND OF SNOW IS POSSIBLE FOR WEDNESDAY...ALTHOUGH MODELS
ARE NOT AS AGGRESSIVE AS THEY WERE YESTERDAY. ANOTHER QUICK MOVING
SHORTWAVE MOVES ACROSS WYOMING DURING THE AFTERNOON AND EVENING
HOURS...WITH SOME LIGHT SNOW ACROSS THE MOUNTAINS AND POTENTIALACROSS
THE EASTERN PLAINS. WINDS WILL ALSO BEGIN TO INCREASE AGAIN LATE
WEDNESDAY AND WEDNESDAY NIGHT AS HIGH PRESSURE NEAR THE SURFACE
BUILDS ON THE WINDWARD SIDE OF THE ROCKY MOUNTAINS. MAY NEED HIGH
WIND HEADLINES FOR THE WIND PRONE AREAS ONCE AGAIN BY EARLY
THURSDAY MORNING WITH GUSTS AROUND 55 TO 60 MPH.
OTHERWISE...BECOMING COLDER EACH DAY WITH HIGHS ON IN THE 20S TO
LOW 30S BY CHRISTMAS EVE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 245 PM MST TUE DEC 22 2015
NEXT UPPER SYSTEM TO AFFECT THE AREA WILL BE DIGGING OVER THE
WESTERN CONUS THURSDAY NIGHT WITH SW FLOW ALOFT OVER THE CWA. SOME
SNOW SHOWERS SHOULD OCCUR OVER THE HIGHER MTNS THURSDAY NIGHT AS
MOISTURE INCREASES IN THE FLOW OVER THAT AREA. ONE BATCH OF ENERGY
EJECTS NORTHEAST ACROSS THE CWA CHRISTMAS DAY WITH LEE
CYCLOGENESIS OVER SE COLORADO. THIS SHOULD BRING AN AREA OF LIGHT
SNOW TO MUCH OF THE CWA IN THE AFTERNOON AND EVENING BODING FOR A
WHITE CHRISTMAS FOR AT LEAST PARTS OF THE CWA FOR THE 4TH TIME IN
THE LAST 5 YEARS. MEANWHILE THE MAIN ENERGY WITH THE UPPER SYSTEM
STILL PROGGED TO CUT OFF OVER ARIZONA FRIDAY NIGHT WHILE THE SNOW
ENDS OVER OUR CWA. MODELS IN PRETTY GOOD AGREEMENT IN TRACKING THE
UPPER LOW ACROSS THE SOUTHERN ROCKYS INTO THE SOUTHERN PLAINS
SATURDAY THROUGH SUNDAY WITH THE GFS A BIT FASTER. THIS KEEPS THE
CWA DRY BUT COLD COMPLIMENTS OF A COLD SFC HIGH THAT WILL SETTLE
OVER THE NORTHERN PLAINS. THE UPPER LOW THEN LIFTS NORTHEAST ON
MONDAY AND MAY BRING A GLANCING SHOT OF WRAP-AROUND LIGHT SNOW TO
THE PANHANDLE. OTHERWISE WARMING SOME MONDAY AS SFC DOWNSLOPE FLOW
SETS UP BEFORE ANOTHER UPPER SHORTWAVE PASSES BY MONDAY NIGHT
BRINGING SOME COOLER AIR AGAIN AS WELL AS SOME MTN SNOW SHOWERS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 951 PM MST TUE DEC 22 2015
WILL CARRY VFR VIS IN LIGHT SNOW FOR SIDNEY THROUGH 07Z THEN
DRY SLOT SHOULD WORK IN FROM THE WEST WITH VFR EXPECTED THROUGH
THE REST OF THE PERIOD. REST OF AIRPORTS VFR THROUGH THE PERIOD
WITH THE EXCEPTION OF RAWLINS AND LARAMIE WHERE WE WILL INTRODUCE
SNOW AGAIN STARTING LATE MORNING RAWLINS WHERE WE HAVE CEILINGS
AND VISIBILITIES DROPPING IN LIGHT SNOW DOWN TO MVFR THEN IFR IN
THE AFTERNOON...THEN STARTING LIGHT SNOW AT LARAMIE IN THE
AFTERNOON DROPPING CEILINGS DOWN TO MVFR.
&&
.FIRE WEATHER...
ISSUED AT 214 PM MST TUE DEC 22 2015
NO FIRE WEATHER CONCERNS IN THE NEAR FUTURE WITH AFTERNOON
HUMIDITY VALUES WELL OUTSIDE OF CRITICAL THRESHOLDS IN ADDITION TO
SEVERAL CHANCES FOR PRECIPITATION OVER THE NEXT SEVERAL DAYS.
HEAVY MOUNTAIN SNOW IS ALREADY OCCURRING IN THE SNOWY/SIERRA
MADRES...AND IS LIKELY TO CONTINUE THROUGH THU.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST WEDNESDAY FOR WYZ112-114.
NE...NONE.
&&
$$
UPDATE...JG
SHORT TERM...TJT
LONG TERM...RE
AVIATION...ZF
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS EUREKA CA
1049 PM PST THU DEC 24 2015
.SYNOPSIS...RAIN AND SNOW SHOWERS WILL COME TO AN END ON FRIDAY
WITH DRY WEATHER EXPECTED FRIDAY NIGHT INTO THE WEEKEND. VERY COLD
OVERNIGHT TEMPERATURES ARE FORECAST FOR FRIDAY NIGHT.
&&
.UPDATE...THE WINTER STORM WARNING HAS BEEN EXTENDED WITH SNOW
CONTINUING TO FALL ACROSS THE NORTH COAST INTERIOR ZONE. GUIDANCE
GENERALLY SHOWS THE SNOW ENDING BY 12Z...BUT OPTED TO EXTEND IT A
FEW MORE HOURS UNTIL AROUND SUNRISE TO COVER ANY MODEL TIMING
ISSUES. OTHERWISE THE FORECAST REMAINS ON TRACK.
&&
.PREV DISCUSSION......ISSUED AT 847 PM PST...
UPDATE...THE HEAVIEST PRECIPITATION HAS NOW ENDED IN THE UPPER
TRINITY AND INTERIOR MENDOCINO ZONES...SO THE WINTER STORM WARNING
HAS BEEN ALLOWED TO EXPIRE AT 7 PM. OTHERWISE THE FORECAST REMAINS
ON TRACK WITH NUMEROUS SHOWERS CONTINUING TO IMPACT HUMBOLDT...
DEL NORTE...WESTERN TRINITY...AND COASTAL MENDOCINO COUNTIES
TONIGHT. SOME OF THE STRONGER CELLS HAVE PRODUCED SMALL HAIL AND
LIGHTNING THIS EVENING.
PREV DISCUSSION......ISSUED AT 406 PM PST...
DISCUSSION...WIDESPREAD SHOWERS ASSOCIATED WITH A COLD SHORTWAVE
TROUGH MOVING OVER THE AREA HAS BROUGHT A VARIETY OF WEATHER IMPACTS
TO NW CALIFORNIA TODAY. THUNDERSTORMS...HAIL...RAIN...AND SNOW HAVE
ALL BEEN REPORTED. HAIL AND LIGHTNING WILL CONTINUE TO BE POSSIBLE
WITH THE STRONGEST SHOWERS FOR COASTAL LOCATIONS THROUGH THE EVENING
AS THERMODYNAMICS CONDUCIVE TO SMALL HAIL AND THUNDERSTORMS REMAIN
IN PLACE. SNOW WAS REPORTED TO AS LOW AS 500 FEET ALONG THE HWY 96
CORRIDOR IN HUMBOLDT COUNTY THIS MORNING. IN GENERAL...SNOW LEVELS
ACROSS THE AREA HAVE RANGED FROM 1500 TO 2000 FEET OR HIGHER. SNOW
TOTALS OF 4 TO 6 INCHES HAVE BEEN REPORTED ACROSS MUCH OF THE
INTERIOR MOUNTAINS ABOVE 2500 FEET WITH ISOLATED TOTALS OF 8 INCHES
OR MORE IN SPOTS. SHOWERS WILL CONTINUE INTO THE EVENING...GRADUALLY
DECREASING OVERNIGHT. ANOTHER 1 TO 4 INCHES OF SNOW LOOK POSSIBLE
ACROSS THE AREA TONIGHT...HIGHEST ACROSS THE NORTH. THE WINTER STORM
WARNING IS ON TRACK TO EXPIRE LATER THIS EVENING FOR INTERIOR AREAS.
A FEW SHOWERS MAY PERSIST DURING THE MORNING ON FRIDAY BEFORE HIGH
PRESSURE BEGINS TO BUILD OVER THE AREA AND CLOUD COVER BEGINS TO
DECREASE...WITH DRY CONDITIONS PERSISTING INTO SATURDAY AND THE
FIRST HALF OF SUNDAY. TEMPERATURES FRIDAY NIGHT INTO SATURDAY
MORNING WILL BE QUITE COLD ACROSS THE AREA WITH TEMPERATURES
POTENTIALLY DOWN INTO THE TEENS ACROSS SOME INTERIOR VALLEYS WITH
20S POSSIBLE FOR COASTAL LOCATIONS. A HARD FREEZE WATCH HAS BEEN
ISSUED FOR THE COASTAL ZONES FRIDAY NIGHT INTO SATURDAY MORNING.
THE NEXT SYSTEM APPROACHES THE AREA ON SUNDAY. MODELS HAVE FINALLY
COME INTO BETTER AGREEMENT ON BRINGING A COLD FRONT INTO THE AREA
SUNDAY AFTERNOON AND EVENING. SNOW LEVELS LOOK TO BE AROUND 3000 TO
4000 FEET...BUT THERE MAY BE LINGERING COLD INTERIOR AIR IN TRINITY
COUNTY THAT COULD LOWER SNOW LEVELS TO 2000 FEET OR LESS. THIS WILL
NEED TO BE WATCHED AS IT GETS CLOSER. THIS SYSTEM LOOKS TO BE MOVING
FAIRLY QUICK SO RAIN/SNOW AMOUNTS WILL BE MODEST. MONDAY THERE MAY
BE A FEW LINGERING SHOWERS AROUND THE AREA.
MODELS NOW PROG HIGH PRESSURE RETURNING TO THE REGION ON TUESDAY AND
PERSISTING THROUGH MUCH OF THE WEEK...KEEPING THE AREA MAINLY DRY.
HAVE BACKED OFF ON POPS FOR THIS TIME FRAME. STP/MKK
AVIATION...VARIABLE CONDITIONS HAVE BEEN OBSERVED ACROSS THE
AREA TODAY AS SHOWERS AND THUNDERSTORMS ASSOCIATED WITH A
SHORTWAVE TROUGH MOVING OVERHEAD HAVE PRODUCED RAIN...SNOW...AND
HAIL. SHRAGS AND VCTS WILL BE POSSIBLE THROUGH THE EVENING HOURS
AS INSTABILITY REMAINS IN PLACE. VFR TO MVFR WILL BE POSSIBLE INTO
THE OVERNIGHT...WITH CIGS AND VSBYS DOWN TO AS LOW AS IFR WITH THE
HEAVIEST SHOWERS. SHOWERS WILL BE ON THE DECREASE LATE TONIGHT
WITH GRADUALLY IMPROVING CONDITIONS AS THE SHORTWAVE TROUGH BEGINS
TO SHIFT EAST. STP
MARINE...GALE FORCE WINDS AND ELEVATED SEAS WILL CONTINUE THROUGH
THE EVENING SO I EXTENDED THE HAZARDOUS SEAS WARNING FOR THE INNER
WATERS TO END AT THE SAME TIME AS THE GALES LATE TONIGHT. WINDS WILL
EASE FRIDAY AND SATURDAY AS RIDGING SHIFTS IN BEHIND THE EXITING
STORM SYSTEM ALLOWING THE PRESSURE GRADIENT TO WEAKEN ACROSS THE
COASTAL WATERS. THE SEA STATE WILL DIMINISH AS WELL AS THE POST
FRONTAL SWELL SUBSIDES INTO THE WEEKEND. ADVISORIES WILL BE NEEDED
FOLLOWING THE GALES EARLY FRIDAY MORNING THEN THERE LOOKS TO BE A
FAVORABLE WEATHER WINDOW ON SATURDAY AS SEAS FALL TO 5 TO 7 FT AND
WINDS BECOME RELATIVELY LIGHT AND VARIABLE. THIS WINDOW WILL BE
SHORT LIVED AS ANOTHER NW SWELL BUILDS ACROSS THE WATERS SUNDAY AND
SOUTH WINDS INCREASE AHEAD OF A FRONT SUNDAY AFTERNOON. KML
HIGH SURF AND COASTAL FLOODING...THE HIGH SURF ADVISORY EXPIRED AS
SURF HEIGHTS DIMINISHED THROUGH THE LATE AFTERNOON. THE NORTHWEST
SWELL WILL CONTINUE TO SUBSIDE FRIDAY AND SATURDAY SO ADDITIONAL
ADVISORIES WILL NOT BE NECESSARY AT LEAST THROUGH THE WEEKEND.
COASTAL FLOODING, ON THE OTHER HAND, WILL BE A POTENTIAL AROUND HIGH
TIDE CHRISTMAS DAY AND SATURDAY AS ASTRONOMICAL TIDES ARE PREDICTED
TO BE VERY HIGH. IMPACTS SHOULD BE SIMILAR TO WHAT WAS OBSERVED
TODAY. WILL ALLOW THE OVERNIGHT SHIFT TO KEEP AN EYE ON THE STORM
SURGE WHICH ESSENTIALLY PUSHES THE TIDE LEVELS INTO CRITICAL LEVELS.
AGAIN, ONLY NUISANCE FLOODING SHOULD OCCUR. KML
&&
.EKA WATCHES/WARNINGS/ADVISORIES...
CA...
HARD FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY
MORNING FOR CAZ001.
COASTAL FLOOD ADVISORY FROM 9 AM TO 1 PM PST FRIDAY FOR CAZ001.
HARD FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY
MORNING FOR CAZ002.
WINTER STORM WARNING UNTIL 6 AM PST FRIDAY ABOVE 2000 FEET FOR
CAZ003.
NORTHWEST CALIFORNIA COASTAL WATERS...
SMALL CRAFT ADVISORY UNTIL 3 AM PST FRIDAY FOR PZZ450-455.
HAZARDOUS SEAS WARNING UNTIL 3 AM PST FRIDAY FOR PZZ450-455.
GALE WARNING UNTIL 3 AM PST FRIDAY FOR PZZ470-475.
&&
$$
VISIT US AT HTTP://WWW.WEATHER.GOV/EUREKA
FOLLOW US ON FACEBOOK AND TWITTER AT:
HTTP://WWW.FACEBOOK.COM/NWSEUREKA
HTTP://WWW.TWITTER.COM/NWSEUREKA
[top]
Area Forecast Discussion
National Weather Service Sacramento CA
1030 PM PST THU DEC 24 2015
.SYNOPSIS...
Dry weather outside of a few lingering mountain showers
is expected for Christmas Day. Saturday looks dry with a slight
threat of precipitation early next week.
&&
.UPDATE DISCUSSION...
Showers winding down over the CWA this evening and have cancelled
all WSW products this evening. Skies are clearing over most of the
CWA due to NVA/sinking in the wake of the strong vort max that
impacted Norcal today...with rain/snow and at least one if not two...
tornadoes...one in the Folsom/El Dorado Hills/Cameron Park area...and
possibly a second in the Modesto/Ceres area. NWS seeks confirmation of
the cause of the wind damage that occurred there this afternoon and will
be investigated further.
Energy on the backside of the longer wave trof over the Wrn States
will spread some more showers over the CWA tonight and Christmas Day.
High resolution HRRR QPF prog suggests some light precip will redevelop
over the Nrn mtns and Siernev tonight and into Christmas morning.
Amounts expected to be light with only minor snow accumulations.
Clearing skies over the Valley may allow patchy F+ to develop by
morning from the central Sac Vly Swd into the Nrn SJV as winds
go light/variable. Clouds should increase over the Nrn half of the
Valley with a chance of showers which should preclude for there. JHM
.Previous Discussion...
Convection developed this afternoon associated with the post cold
front environment with some solar heating. A strong vort max pass
overhead, producing enough shear for at least one tornadic storm
in El Dorado County. Storm videos show a clear tornado touchdown
there. A preliminary look at damage photos and radar imagery
suggest a tornado may have touched down in the Modesto/Ceres area,
but do not have any verification visually of a tornado. Lingering
convection is fading as evening begins and do not expect
additional strong storms.
Generally dry weather is expected for Christmas. Cold, sub
freezing temperatures are expected Christmas morning across the
area, and again on Saturday and Sunday. Sunday could see
temperatures reaching the upper 20s across the Valley and
foothills. EK
&&
.EXTENDED DISCUSSION (Monday THROUGH Thursday)
The cold upper wave will continue moving through the region
through Monday. Given the splitting nature of this system, not
much in the way of precipitation is expected. Afterward, a drier
northerly flow develops across much of the West Coast. The ECMWF
and Canadian models hint at a few weak upper waves moving over
NorCal during next week, whereas the GFS keeps the area dry. Will
maintain "slight chance" wording in the forecast to convey
uncertainty.
Dang
&&
.AVIATION...
QUICK-MOVING WINTRY SYSTEM MOVing ACROSS THE REGION. ACROSS
VALLEY TAF SITES, MAINLY VFR/MVFR CONDITIONS ARE EXPECTED IN -SHRA
THROUGH THE AFTERNOON. ACROSS THE MOUNTAINS, LIFR WITH SNOW
LEVELS 1500-2500 FT. LOCAL SOUTH WIND GUSTS TO 25 KT POSSIBLE
TODAY ACROSS THE VALLEY.
&&
.STO Watches/Warnings/Advisories...
Winter Storm Warning until 4 AM PST Friday for Motherlode-West
Slope Northern Sierra Nevada.
&&
$$
AREA FORECAST DISCUSSION
NWS RENO NV
950 PM PST THU DEC 24 2015
.UPDATE...THE THREAT FOR STEADY HEAVY SNOW HAS ENDED AS THE CORE OF
THE UPPER LOW HAS MOVED EAST INTO THE GREAT BASIN. WINTER STORM
WARNINGS AND ADVISORIES HAVE BEEN CANCELED FOR MOST ZONES. THE
EXCEPTION IS MONO COUNTY WHERE STRONGER SHOWERS AND BLOWING SNOW
WILL CONTINUE TO CREATE DANGEROUS TRAVEL CONDITIONS, INCLUDING ALONG
HIGHWAY 395 OVER CONWAY SUMMIT AND NEAR MAMMOTH LAKES. THE WINTER
STORM WARNING FOR MONO COUNTY REMAINS IN EFFECT UNTIL 4 AM CHRISTMAS
MORNING.
CURRENT SATELLITE IMAGERY SHOWS A WEAK SHORTWAVE OVER NORTHERN
CALIFORNIA WHICH WILL SLOWLY TRACK NORTH TO SOUTH OVER THE SIERRA
AND WESTERN NV. THERE IS POTENTIAL FOR THIS WAVE TO CREATE SCATTERED
SNOW SHOWERS WHICH COULD LOCALLY CREATE A BURST OF AN INCH OR TWO OF
SNOW ACCUMULATION TONIGHT THROUGH CHRISTMAS MORNING.
CHAIN CONTROLS/TRAVEL RESTRICTIONS REMAIN IN EFFECT FOR MOST ROADS
ABOVE 5000 FEET ELEVATION AND EVEN AT LOWER ELEVATIONS ROADS TONIGHT
MAY HAVE ICY SPOTS (BLACK ICE) DUE TO REFREEZING OF MELTED SNOW. JCM
.PREVIOUS DISCUSSION... /ISSUED 135 PM PST THU DEC 24 2015/
SYNOPSIS...
AFTER HEAVY SNOW SHOWERS MOVE OUT TONIGHT, A FEW LIGHT SNOW
SHOWERS REMAIN POSSIBLE ON FRIDAY. FRESH SNOWCOVER WILL LEAD TO
WIDESPREAD COLD TEMPERATURES CHRISTMAS DAY THROUGH THE WEEKEND. A
WEAKENING STORM WILL BRING LIGHT SNOW SHOWERS TO THE REGION
MONDAY, WITH POTENTIAL FOR A SLIDER WEDNESDAY OR THURSDAY
PROVIDING A CHANCE FOR SNOW IN NORTHERN AND WESTERN NEVADA.
&&
SHORT TERM...
ONGOING WINTER STORM BEHAVING MORE OR LESS AS EXPECTED WITH
SIGNIFICANT TRAVEL IMPACTS CONTINUING INTO THE EVENING HOURS.
WE`VE SEEN BIG DELAYS AND TEMPORARY ROAD CLOSURES OVER THE SIERRA,
AND DELAYS/DIVERSION INTO RNO AIRPORT DUE TO HEAVY SNOW AND LOW
VISIBILITY. OVERALL THE BULK OF THE HEAVY SNOW SHOWERS WILL SETTLE
SOUTHWARD THROUGH THE AFTERNOON AND EVENING. SEE OUR SOCIAL MEDIA
AND LSR FOR SPECIFIC SNOW REPORTS. MAIN FORECAST ISSUES ARE --
* WITH NUMEROUS REPORTS OF 20:1 SNOW RATIOS (UNSURPRISING) AND
BURSTS OF HEAVY PRECIP SEEN IN THE HRRR, I`VE INCREASED SNOW
TOTAL FORECASTS FOR THE SIERRA FRONT, TAHOE, AND MONO CO
REGIONS. SNOW AMOUNTS WILL VARY A LOT DUE TO SHOWERY/BANDED
NATURE OF THE PRECIP GIVEN UNSTABLE AIRMASS. LAKE EFFECT OFF OF
TAHOE HAS OCCURRED PERIODICALLY TODAY AND THE RISK CONTINUES
INTO EARLY EVENING WITH WESTERLY FLOW ALOFT FOR CARSON
CITY/CARSON VALLEY. OVERALL MESSAGE IS THE SAME THOUGH - ROUGH
TRAVEL ON ROADS AREAWIDE THROUGH THIS EVENING, WITH AREAS OF
BLOWING SNOW AND ZERO VISIBILITY IN THE MOUNTAINS. REFREEZE OF
MELTED SNOW ON ROADS WILL BE AN ISSUE TOO TONIGHT.
* GUIDANCE IS SHOWING A SECONDARY WAVE ALOFT DROPPING IN LATE
TONIGHT AND FRIDAY, WHICH COULD SPARK ADDITIONAL SNOW SHOWER
DEVELOPMENT. LOCATION OF THIS ACTIVITY HIGHLY VARIABLE IN THE
SIMULATIONS BUT BEST BET IS THE SIERRA WITH A SLIGHT UPSLOPE
COMPONENT, BUT AIRMASS REMAINS COLD AND UNSTABLE AREA WIDE SO WE
CAN`T RULE OUT SHSN ANYWHERE FRIDAY. A QUICK 1-3" ACCUM POSSIBLE
DEPENDING ON HOW ROBUST THE SHOWERS BECOME.
CS
LONG TERM...SATURDAY TO WEDNESDAY...
COLD PROGRESSIVE FLOW WILL CONTINUE INTO THE WEST COAST WHICH MAY
ALLOW A COUPLE FAST MOVING SYSTEMS TO IMPACT THE AREA INTO THE
MIDDLE OF NEXT WEEK.
AS THE CURRENT TROUGH OVER THE REGION EXITS ON FRIDAY NIGHT,
NORTHEAST TO EAST WINDS WILL DEVELOP IN THE SIERRA AND TAHOE BASIN.
HAVE ISSUED A LAKE WIND ADVISORY FOR TAHOE FOR FRIDAY NIGHT AND
SATURDAY MORNING WITH WAVES UP TO 4 FEET AND GUSTS NEAR 35 MPH.
FOR THE WEEKEND, CONDITIONS WILL BE DRY AND COLD. OVERNIGHT LOWS
WILL BE BELOW ZERO IN MOST SIERRA VALLEYS AND IN THE -5 TO 15 RANGE
ACROSS WESTERN NEVADA AND NORTHEAST CALIFORNIA WITH THE FRESH SNOW
COVER. VALLEY INVERSIONS WILL LIKELY DEVELOP AND KEEP AFTERNOON
HIGHS IN THE 20S TO LOW 30S.
NEXT SYSTEM SHOULD ARRIVE IN TIME FOR THE MONDAY MORNING COMMUTE.
LIQUID AMOUNTS IN THE MODELS ARE LESS THAN 0.10 INCH, WITH SNOW
LEVELS NEAR AND BELOW 4000 FEET. SNOW AMOUNTS SHOULD BE LESS THAN AN
INCH FOR MOST LOCATIONS, THOUGH EVEN A HALF INCH OF SNOW COULD CAUSE
TRAVEL ISSUES FOR THE MONDAY MORNING COMMUTE.
MODELS SHOW A SECOND SLIDER SYSTEM FOR MID WEEK, BUT TRACK WILL
DEPEND ON WHERE THE EASTERN PACIFIC RIDGE SETS UP. FOR NOW THE TRACK
OF THIS SYSTEM VARIES BETWEEN WESTERN NEVADA AND UTAH. IF THE TRACK
IS OVER WESTERN NEVADA, ANOTHER ROUND OF SNOW ON VALLEY FLOORS IS
LIKELY. SOMETHING TO KEEP AN EYE ON OVER THE NEXT FEW DAYS. BRONG
&&
AVIATION...
SNOW SHOWERS WILL BRING QUICK VARIATIONS IN FLIGHT CONDITIONS FOR
AREA AIRPORTS, RANGING FROM VFR TO LIFR IN A MATTER OF MINUTES.
BASED ON THE LATEST HRRR GUIDANCE, THE MAIN RISK AREA FOR THIS
WILL SETTLE SOUTHWARD THROUGH THE AFTERNOON AND EVENING. FOR
RNO/CXP 22Z-01Z WILL MARK THIS TRANSITION FROM HEAVIER SHOWERS TO
LIGHTER ONES, TVL/TRK SOMETIME BETWEEN 01-03Z, AND MMH 04-06Z.
ADDITIONAL SNOW ACCUMULATIONS ARE LIKELY WITH RATES IN SHOWERS
1"/HOUR FOR RNO/CXP, AND POSSIBLY 2-3"/HR FOR TVL/TRK/MMH.
AFTER 6Z/FRIDAY MAIN ISSUES WILL BE RESIDUAL CLOUDS AND LIGHT
SNOW SHOWERS NEAR THE MOUNTAINS, LEADING TO TERRAIN OBSCURATION.
SECONDARY WAVE ALOFT MAY BRING SOME MVFR SNOW SHOWERS TO THE
REGION BETWEEN 9Z/FRI-21Z/FRI. PREDICTABILITY OF THESE IS LOW DUE
TO VARYING TRACKS IN THE SIMULATIONS, SO AM ADDRESSING WITH VCSH
IN THE TAFS. MOST LIKELY AIRPORTS TO SEE THESE ARE TVL/TRK. CS
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ005.
LAKE WIND ADVISORY FROM 10 PM FRIDAY TO 10 AM PST SATURDAY FOR
LAKE TAHOE IN NVZ002.
CA...WINTER STORM WARNING UNTIL 4 AM PST FRIDAY CAZ073.
LAKE WIND ADVISORY FROM 10 PM FRIDAY TO 10 AM PST SATURDAY FOR
LAKE TAHOE IN CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
329 AM CST FRI DEC 25 2015
.SHORT TERM...(Today)
ISSUED AT 329 AM CST FRI DEC 25 2015
09z/3am surface analysis shows weak frontal boundary extending from
southern Ohio to Arkansas, with a 1023mb high noted further upstream
across Iowa. A few sprinkles have been occurring from time to time
across the E/SE KILX CWA in association with the Ohio River Valley
front and this trend will continue for the next few hours as per the
HRRR forecast. As a result, will carry slight chance for light
showers south of I-70. Meanwhile, an area of low clouds/fog trapped
beneath the subsidence inversion beneath the Iowa high has been
slowly spreading eastward over the past few hours. Latest satellite
shows the leading edge of the clouds along a Galesburg to Macomb
line. Based on satellite trends and HRRR cloud height forecast,
will feature overcast conditions along/west of the Illinois River
this morning. The low clouds will gradually dissipate toward
midday, followed by partly sunny conditions across the board through
afternoon. High temperatures will mainly be in the middle to upper
40s, with lower 50s across the E/SE.
&&
.LONG TERM...(Tonight through Thursday)
ISSUED AT 329 AM CST FRI DEC 25 2015
Major rain event is still unfolding across parts of central and
southeast Illinois this weekend as deep-layer southwesterly flow
establishes itself across the region. As upper low cuts off over
the Desert Southwest and a corresponding ridge develops downstream
across the eastern CONUS, the Ohio River Valley frontal boundary
will lift northward into central Illinois late tonight into
Saturday. The front will then become parallel to the upper flow and
stall across the area. With baroclinic zone in place, plenty of
Gulf of Mexico moisture flowing northward, and weak upper waves
tracking through the southwest flow to provide enhanced lift...a
prolonged period of moderate to heavy rain will develop this
weekend. Models have continued to slow the process however, with
tonight now remaining mostly dry. Have lowered PoPs to just
slight chance across all but the far S/SE accordingly. As front
stalls, rain will begin in earnest on Saturday, then continue
through Saturday night. Thanks to increasing instability, may
even see a few thunderstorms as well. As seen for the past
several model runs, a northern stream short-wave tracking from the
Northern Plains into the Great Lakes will push the front further
south on Sunday. 00z Dec 25 models are in good agreement that
the boundary will drop well south of the Ohio River, resulting in
decreasing rain chances Sunday/Sunday night. In fact, have
dropped PoPs altogether along/north of a Rushville to Bloomington
line during the afternoon and as far south as the I-72 corridor by
evening. Further south, rain will continue to fall across the
remainder of the area through Sunday night.
A vigorous wave coming off the Pacific will eventually eject the
Desert Southwest closed upper low northeastward early next week,
with the latest models now in much better agreement concerning the
timing of this process. The exact track of the low still remains in
question however, which poses some big challenges to the PoP/precip
type forecast late Sunday night through Monday night. ECMWF remains
the further west with the track...taking the corresponding surface
low from near St. Louis midday Monday to Chicago by midnight.
Meanwhile both the GFS and GEM are further east...with the low
tracking from western Kentucky to northwest Ohio during that time
frame. Will follow the more consistent ECMWF here, which keeps the
KILX CWA warmer and results in mostly liquid precip. May see a
period of light freezing rain on the northern periphery of the
precip as it returns northward late Sunday night into Monday:
however, with warm nose aloft at 5-6C and surface temps only
slightly below freezing across the north, think any ice accumulation
will be minimal. Based on expected surface temps, will mention
freezing rain along/north of a Rushville...to Lincoln...to Danville
line. Temps will edge above freezing everywhere toward midday
Monday, resulting in a change over to all rain. As the low
approaches, may even see a few thunderstorms south of the I-72
corridor. Once the low tracks into the southern Great Lakes, enough
cold air will be pulled down behind it to support a change over to
snow or a rain/snow mix along/north of a Taylorville to Danville
line Monday night. Will need to keep an eye on this, as any
eastward deviation of the low track will lead to more snow and
possible accumulations across the area.
Precip will come to an end on Tuesday, with storm total rainfall
from tonight through Monday night ranging from around 1 inch
northwest of the Illinois River...to as much as 5-6 inches
along/south of I-70. With so much rain expected to fall on already
wet soil and the potential for thunderstorms to produce excessive
rainfall rates, will be issuing a Flash Flood Watch for areas
along/southeast of a Danville to Taylorville line starting midday
Saturday and ending Monday evening. Main concerns will be rapid
rises on area creeks/streams and urban flooding in poor drainage
areas.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1105 PM CST THU DEC 24 2015
Short term models suggest the potential for some MVFR/IFR cigs
affecting our western TAF sites (PIA/SPI) after 09z and holding
thru about 14z. Boundary layer winds are expected to turn more
into the west and northwest later tonight which will help push
some of the low clouds already in east central Iowa into at least
west central IL late tonight. Have already had a scattered lower
cloud group in the SPI and PIA TAFs and see no reason to stray
from that. Based on some of the latest soundings, may need to
consider going broken with the cigs at those two locations as
the moisture in the low levels increases towards sunrise Fri.
Confidence on coverage of bkn-ovc MVFR/IFR cigs rather low at
this time so rather than broad brush with tempo groups, will
leave the current TAFs as is, and possibly just add scattered
groups further to the east.
As the boundary layer flow goes into a northeast to east
direction on Sunday, any low level clouds should get a push back
to the west and southwest. So the higher probabilities for VFR
conditions will be at DEC and CMI, with areas roughly along and
west of I-55 having the better chance for seeing the lower clouds
late tonight. Light west to northwest winds tonight will become
northeast to east at 8 to 15 kts on Friday.
&&
.ILX Watches/Warnings/Advisories...
Flash Flood Watch from Saturday afternoon through Monday
afternoon for ILZ052-054>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
1112 PM CST THU DEC 24 2015
...AVIATION UPDATE...
.SHORT TERM...(This Evening through Friday)
Issued at 258 PM CST THU DEC 24 2015
A large upper trough remains over the western and
central US this afternoon. Near Kansas, there was an exiting
shortwave across Iowa and a strong upper jet oriented SW to NE
across Kansas. Low clouds over northeast Kansas dissipated this
afternoon in area subsidence behind the shortwave. A weak area of
surface high pressure should be centered over northwest Missouri
by 12Z Friday morning. There will likely be some mid/high clouds
over the area tonight due to the upper jet. Patchy fog is
possible, especially in our eastern counties closer to the center
of the high.
Surface low deepens over the western plain on Friday and southeast
surface flow and warm advection should occur over eastern Kansas.
Relatively mild and dry conditions for Christmas day. Increasing
moisture overall should result in increased cloudiness during the
day. Precipitation will likely hold off through the afternoon.
.LONG TERM...(Friday Night through Thursday)
Issued at 258 PM CST THU DEC 24 2015
By Saturday morning a piece of energy will break off the main
shortwave trough over the southwest US. This will drag a cold front
through the area during the day Saturday. A 1040 mb high will
advance southward through the high plains, which will reinforce a
sub freezing air mass just north of the area. The freezing line may
reach north central KS by the evening hours, and push through
portions of eastern KS through the overnight. The models then show a
wave of post frontal precip developing and spreading northward
across eastern KS during the overnight. During this period the
freezing air could undercut precip so there may be a transition
to from rain to a wintry mix. There seems to be a warm nose
present initially, but how warm it will be is uncertain. This will
depend on the slope of the cold air, and where the low to mid
level fronts will be located. During this period there may be
light accumulations that could disrupt travel. By noon Sunday most
of the precip gets shunted to the south as the surface high tracks
across the northern US. At this time the main shortwave trough
will begin to eject out over the plains. The exact strength and
track is still unknown, but the models seem to depict cooler
solutions. As of now the best chance for accumulating winter
precip would be Sunday night into Monday night. Stay tuned for
updates.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday)
Issued at 1112 PM CST THU DEC 24 2015
Dewpoint temps have been dropping lower as temps cool for the last
several hours. Additionally forecast soundings continue to show
boundary layer moisture to be very shallow with drier air possibly
entraining into the top of the boundary layer. Because of this,
think chances for ground fog remain relatively small and will keep
a VFR forecast going in spite of the RAP and HRRR progs of fog
development. VFR conditions should persist through the day Friday.
However think conditions could start to deteriorate towards 06Z
Saturday as a low level warm air advection pattern strengthens and
moisture advection increases. Since this is towards the end of the
forecast period, have not included any lower CIGS or VSBY at this
time, but I would expect restricted conditions by 12Z Saturday.
&&
.TOP Watches/Warnings/Advisories...NONE.
&&
$$
SHORT TERM...Johnson
LONG TERM...Sanders
AVIATION...Wolters
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
130 AM EST FRI DEC 25 2015
.UPDATE...
ISSUED AT 129 AM EST FRI DEC 25 2015
FRESHENED UP THE HOURLY TEMPERATURES AND DEW POINTS BASED ON THE
LATEST TRENDS IN OBSERVATIONS. SOME OF THE COOLER VALLEYS STILL
REMAIN IN THE 45 TO 50 DEGREE RANGE...WITH PATCHY DENSE FOG. STILL
EXPECTING THIS TO MIX OUT GRADUALLY FROM SOUTHWEST TO NORTHEAST AS
THICKER CLOUD COVER MOVES IN THROUGH DAWN.
UPDATE ISSUED AT 1150 PM EST THU DEC 24 2015
CONTINUING TO SEE QUITE A BIT OF CLEARING ACROSS THE REGION AND
MANY OF THE VALLEY LOCATIONS/AREAS NEAR TO BODIES OF WATER ARE
LIKELY SEEING PATCHY DENSE FOG. ANOTHER CLUE OF THE FOG FORMATION
IS THE FACT THAT QUICKSAND MESONET HAD A QUICK DROP TEMP WISE AND
HAS SINCE RECOVERED. THAT SAID UPGRADED TO PATCHY DENSE VALLEY FOG
IN THE GRIDS. THIS HAS ALSO MADE KEEPING A CONSISTENT TEMP CURVE
NEARLY IMPOSSIBLE...BUT HAVE UPDATED THAT ALONG WITH DEWS/WINDS
TO LATEST OBS AND TRENDS. ALSO SENT OUT A GNOW TO FOCUS OF THE
PATCHY DENSE VALLEY FOG.
UPDATE ISSUED AT 1001 PM EST THU DEC 24 2015
WE HAVE SEEN MOSTLY CLEAR SKIES IN MANY LOCATIONS THIS EVENING AND
GIVEN THE RECENT RAINFALL AT LEAST SOME PATCHY VALLEY FOG WILL BE
POSSIBLE. THIS HAS ALSO LEAD TO DIFFICULT TEMP CURVE THIS
EVENING...GIVEN THE QUICK DROPS INTO THE LOWER 50S IN THOSE DEEPER
VALLEY SPOTS DUE TO THE DECOUPLING. SEEMS LIKE THE MOSGUIDE WAS
HANDLING VALLEYS BETTER OVERALL...WHILE THE MODEL BLEND SEEMED TO
TO BETTER ELSEWHERE. UPDATED GRIDS TO REFLECT THIS OVERALL
THINKING OF INTRODUCING VALLEY FOG AND ADJUSTING TEMPS/DEWS/WINDS
WITH LATEST OBS/TRENDS.
UPDATE ISSUED AT 710 PM EST THU DEC 24 2015
THIS EVENING QUASI STATIONARY BOUNDARY IS ANALYZED AROUND EASTERN
KY THEN BACK TO OUR SW ACROSS THE SOUTHERN MISSISSIPPI RIVER
VALLEY. WE ARE SEEING SOME MAINLY HIGH CLOUDS ACROSS A GOOD
PORTION OF THE REGION BASED ON OBS AND SAT TONIGHT WITH BEST
COVERAGE TO SOUTH AND EAST. THESE CLOUDS WILL BEGIN TO THICKEN
OVERNIGHT. WHILE WE REMAIN WELL ABOVE NORMAL WITH DEEP SOUTH TO SW
FLOW ACROSS THE REGION THIS CHRISTMAS EVE...THE DEEPER VALLEYS
WILL OR ALREADY HAVE MANAGED TO DECOUPLE TONIGHT...WITH QUICKSAND
AND PAINTSVILLE MESONETS ALREADY DROPPING BELOW THE 60 DEGREE MARK
THIS HOUR. DID UPDATE GRIDS TO CAPTURE THIS A BIT EARLIER...BUT
OTHERWISE GRIDS REMAIN IN GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM EST THU DEC 24 2015
19Z SFC ANALYSIS SHOWS A RELATIVE AREA OF HIGH PRESSURE OVER THE
OHIO VALLEY WHILE LOW PRESSURE IS BUILDING TO THE SOUTHWEST. ON
SATELLITE...A BRIEF PERIOD OF LOW CLOUDS AROUND MIDDAY HAVE
BROKEN UP AND SCATTERED OUT DURING THE EARLY AFTERNOON LEAVING
MOSTLY SUNNY CONDITIONS. THAT SUNSHINE...AND SOME LIMITED
DRYING...RESULTED IN TEMPERATURES SPIKING INTO THE UPPER 60S AND
LOWER 70S THROUGH EAST KENTUCKY THIS AFTERNOON. DEWPOINTS HAVE
FALLEN INTO THE LOW AND MID 50S..BUT ARE STILL VERY HIGH FOR THIS
TIME OF YEAR. MEANWHILE...WINDS ARE LIGHT AND VARIABLE THROUGH THE
AREA...GENERALLY FROM THE SOUTH FOR LOCATIONS SOUTH OF THE
MOUNTAIN PARKWAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE LONGWAVE PATTERN
AS THEY ALL SHOW THE SOUTHEAST RIDGE STRENGTHENING AND WOBBLING
WEST INTO FRIDAY WHILE LARGE AND FAIRLY STRONG TROUGHING DIVES
INTO THE DESERT SOUTHWEST. THIS WILL ALL SERVE TO STRENGTHEN THE
BROAD AND DEEP SOUTHWEST FLOW THROUGH THE REGION INTO SATURDAY
MORNING. WHILE THE MAJORITY OF THE ENERGY IN THIS PATTERN WILL
STAY WITH THE WESTERN TROUGH...THERE WILL BE A FEW WEAK WAVES THAT
RIDE OVER THE AREA DURING THE SHORT TERM PORTION OF THE FORECAST.
OF MOST SIGNIFICANCE WILL BE THE RECORD OR NEAR RECORD HIGH PW
AIR IN PLACE OVER THE REGION DURING THE DAY FRIDAY INTO
SATURDAY...THAT THE MODELS ARE PRETTY MUCH IN CONCURRENCE WITH.
AS SUCH...WILL FOLLOW A BLENDED MODEL SOLUTION FAVORING THE HIGHER
RESOLUTION HRRR AND NAM12 ALONG WITH INPUT FROM THE NATIONAL
CENTERS.
SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF OUR VERY WARM
HOLIDAY PERIOD WITH TEMPERATURES NOT FALLING TOO FAR INTO THE 50S
FOR MOST SPOTS TONIGHT. ALTHOUGH...AM EXPECTING A BIT OF A RIDGE
TO VALLEY TEMPERATURE SPLIT THIS EVENING AND INTO THE FIRST PART
OF THE OVERNIGHT. THIS SHOULD BE MOST NOTICEABLE IN THE FAR
EASTERN SHELTERED VALLEYS AND IS EXPECTED TO MIX OUT TOWARDS DAWN.
THE NEXT SURGE IN PCPN WILL LIKELY MOVE IN FROM THE SOUTHWEST
AROUND DAWN AS WELL AND OVERSPREAD THE ENTIRE CWA BY MID MORNING.
EXPECT LIGHT TO MODERATE SHOWERS ALONG WITH A POTENTIAL FOR
THUNDERSTORMS INTO THE DAY FRIDAY AS AN INVERTED TROUGH/SFC WAVE
MOVES THROUGH KENTUCKY. THIS WILL ACTIVATE THE HIGH MOISTURE
CONTENT IN PLACE AND COULD LEAD TO TRAINING ISSUES IN A FEW
SPOTS...PARTICULARLY THOSE THAT MAY HAVE SEEN SATURATING TO HEAVY
RAINS OVER THE PAST DAY OR SO. DO EXPECT THE HIGHEST RAINFALL
TOTALS THROUGH SATURDAY MORNING TO FALL OVER THE CUMBERLAND
VALLEY BEFORE THE RESPONSIBLE WAVE PULLS OUT OF THE AREA EARLY
SATURDAY. GIVEN THE POTENTIAL HAVE DECIDED TO ISSUE A FLOOD WATCH
STARTING AT 6 AM FRIDAY AND RUNNING THROUGH 8 AM SATURDAY...WITH
BETWEEN 1.5 AND 2.5 INCHES OF RAIN POSSIBLE DURING THIS TIME
FRAME. THIS WATCH WILL COVER POINTS GENERALLY SOUTH OF INTERSTATE
64. CONFIDENCE IS FAIRLY HIGH THAT A GOOD SWATH OF RAIN WILL FALL
OVER A GOOD PORTION OF THE CWA DURING THIS TIME...BUT LOW FOR ANY
PARTICULAR PLACEMENT GIVEN SOME DISCREPANCIES WITH THE HIGHEST
AXIS OF QPF FROM EACH MODEL. IN ADDITION...THE CONCERN FOR HEAVY
RAIN WILL RUN INTO THE NEW WEEK AND FOR THAT OVERARCHING RAINFALL
THREAT WILL ISSUE AN ESF.
FOR TEMPERATURES AND DEWPOINTS...HAVE MAINLY GONE WITH THE
SHORTBLEND GUIDANCE THROUGH FRIDAY MORNING AND THEN THE SUPERBLEND
INTO SATURDAY MORNING. DID MAKE SOME NEAR TERM ADJUSTMENTS INTO
THE FIRST PART OF THE NIGHT FOR A PARTIAL AND BRIEF RIDGE TO
VALLEY TEMPERATURE SPLIT. NOT EXPECTING MUCH OF A DIFFERENCE IN
TEMPS FRIDAY NIGHT GIVEN THE PCPN. AS FOR POPS...ENDED UP ON THE
HIGH SIDE OF GUIDANCE THROUGH THE PERIOD...ESPECIALLY TONIGHT AT
LOZ WHERE THE WETTER MET NUMBERS WERE PREFERRED.
WHILE RECORD HIGH MINIMUM TEMPERATURES ARE EXPECTED BOTH TONIGHT
AND FRIDAY NIGHT...HIGH TEMPERATURE RECORDS FOR TOMORROW WILL
LIKELY NOT FALL DUE TO A VERY WARM CHRISTMAS BACK IN 1982.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EST THU DEC 24 2015
THE MAIN CONCERN FOR THIS PERIOD WILL BE THE POTENTIAL FOR
REPEATING ROUNDS OF RAINFALL THROUGH EARLY NEXT WEEK WITH A DEEP
AND MOISTURE LADEN SOUTHWEST FLOW IN PLACE ALOFT. A WAVY FRONTAL
BOUNDARY WILL LIFT NORTHWARD ACROSS OUR AREA ON SATURDAY ALLOWING
FOR A BREAK IN THE RAINFALL FOR MOST OF EASTERN KENTUCKY FROM
SATURDAY AFTERNOON THROUGH SUNDAY MORNING. FOR THIS REASON...THE
FLOOD WATCH ISSUED WILL ONLY RUN THROUGH AROUND DAWN ON SATURDAY.
HOWEVER...DEEPENING LOW PRESSURE WILL DRIVE NORTHEASTWARD OUT OF
TEXAS LATE IN THE WEEKEND INTO THE DAY ON MONDAY AND THIS WILL
SEND THE FRONT AND A LOAD OF MOISTURE BACK ACROSS THE REGION
BEGINNING SUNDAY AFTERNOON AND LASTING THROUGH MONDAY NIGHT. A
COUPLE OF INCHES OF ADDITIONAL RAINFALL IS LIKELY DURING THIS SECOND
WAVE OF RAIN...WHICH WILL LIKELY CAUSE ADDITIONAL FLOOD CONCERNS.
THIS SYSTEM WILL EXIT TO OUR EAST WITH DIMINISHING RAIN CHANCES ON
TUESDAY.
THE OTHER STORY TO TOUCH ON IS THE UNSEASONABLE WARMTH. PROGGED
850 MB TEMPS ON SATURDAY OF AROUND 15C ARE CLOSE TO RECORD HIGHS
ACCORDING TO SPC SOUNDING CLIMATOLOGY. HIGH TEMPS ARE FORECAST TO
EASILY ECLIPSE RECORDS SATURDAY BY CLIMBING INTO THE LOW TO MID
70S. THIS MAY BE CONSERVATIVE IF CLOUDS SCATTER OUT FOR ANY LENGTH
OF TIME. TEMPS ON SUNDAY WILL AGAIN THREATEN RECORDS AS THEY CLIMB
TO AROUND 70 SOUTH OF I-64...BEFORE A COOLER BUT STILL ABOVE NORMAL
AIRMASS FILTERS IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK. IF
OUR FORECAST PANS OUT THROUGH DECEMBER 31ST...THIS WILL EASILY BE
THE WARMEST DECEMBER ON RECORD AT BOTH JKL AND LOZ. IN FACT...OUR
AVERAGE TEMPERATURE THIS DECEMBER AT JKL AND LOZ WILL LIKELY BE A
COUPLE DEGREES WARMER THAN THE AVERAGE NOVEMBER TEMPERATURE AT
THOSE SITES WHEN ALL IS SAID AND DONE!
BEYOND TUESDAY...FORECAST MODELS KEEP US IN SOUTHWEST FLOW ALOFT
WITH ANOTHER SHORTWAVE PROGGED TO BRING ANOTHER ROUND OF SHOWERS
WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY A RETURN TO MORE
SEASONAL TEMPERATURES BY NEW YEARS EVE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 129 AM EST FRI DEC 25 2015
MVFR OR WORSE FOG WILL CONTINUE TO PLAGUE SOME OF THE VALLEYS FOR
THE NEXT SEVERAL HOURS...UNTIL LOW LEVEL CLOUD COVER INCREASES
FROM THE SOUTHWEST. RAIN SHOWERS AND SCATTERED THUNDERSTORMS WILL
BE MOVING IN FROM THE SOUTHWEST TOWARDS DAWN...WTH ACTIVITY
EXPANDING ACROSS ALL OF EASTERN KENTUCKY THROUGH THE DAY. CEILINGS
WILL EVENTUALLY DROP DOWN TO IFR OR WORSE AT TIMES...WITH IFR
VISIBILITIES POSSIBLE WITHIN ANY PASSING THUNDERSTORMS OR MORE
INTENSE SHOWERS. LIGHT SOUTH TO SOUTHEAST WINDS OVERNIGHT WILL
INCREASE TO 5 TO 10 KTS DURING THE DAY. THE DIRECTION WILL VARY
FROM THE NORTHEAST TOWARDS I-64...TO THE SOUTH SOUTHWEST NEAR THE
TENNESSEE BORDER...AS A SURFACE FRONT DEVELOPS ACROSS OUR AREA.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM 6 AM EST THIS MORNING THROUGH SATURDAY MORNING
FOR KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS JACKSON KY
1150 PM EST THU DEC 24 2015
.UPDATE...
ISSUED AT 1150 PM EST THU DEC 24 2015
CONTINUING TO SEE QUITE A BIT OF CLEARING ACROSS THE REGION AND
MANY OF THE VALLEY LOCATIONS/AREAS NEAR TO BODIES OF WATER ARE
LIKELY SEEING PATCHY DENSE FOG. ANOTHER CLUE OF THE FOG FORMATION
IS THE FACT THAT QUICKSAND MESONET HAD A QUICK DROP TEMP WISE AND
HAS SINCE RECOVERED. THAT SAID UPGRADED TO PATCHY DENSE VALLEY FOG
IN THE GRIDS. THIS HAS ALSO MADE KEEPING A CONSISTENT TEMP CURVE
NEARLY IMPOSSIBLE...BUT HAVE UPDATED THAT ALONG WITH DEWS/WINDS
TO LATEST OBS AND TRENDS. ALSO SENT OUT A GNOW TO FOCUS OF THE
PATCHY DENSE VALLEY FOG.
UPDATE ISSUED AT 1001 PM EST THU DEC 24 2015
WE HAVE SEEN MOSTLY CLEAR SKIES IN MANY LOCATIONS THIS EVENING AND
GIVEN THE RECENT RAINFALL AT LEAST SOME PATCHY VALLEY FOG WILL BE
POSSIBLE. THIS HAS ALSO LEAD TO DIFFICULT TEMP CURVE THIS
EVENING...GIVEN THE QUICK DROPS INTO THE LOWER 50S IN THOSE DEEPER
VALLEY SPOTS DUE TO THE DECOUPLING. SEEMS LIKE THE MOSGUIDE WAS
HANDLING VALLEYS BETTER OVERALL...WHILE THE MODEL BLEND SEEMED TO
TO BETTER ELSEWHERE. UPDATED GRIDS TO REFLECT THIS OVERALL
THINKING OF INTRODUCING VALLEY FOG AND ADJUSTING TEMPS/DEWS/WINDS
WITH LATEST OBS/TRENDS.
UPDATE ISSUED AT 710 PM EST THU DEC 24 2015
THIS EVENING QUSI STATIONARY BOUNDARY IS ANALYZED AROUND EASTERN
KY THEN BACK TO OUR SW ACROSS THE SOUTHERN MISSISSIPPI RIVER
VALLEY. WE ARE SEEING SOME MAINLY HIGH CLOUDS ACROSS A GOOD
PORTION OF THE REGION BASED ON OBS AND SAT TONIGHT WITH BEST
COVERAGE TO SOUTH AND EAST. THESE CLOUDS WILL BEGIN TO THICKEN
OVERNIGHT. WHILE WE REMAIN WELL ABOVE NORMAL WITH DEEP SOUTH TO SW
FLOW ACROSS THE REGION THIS CHRISTMAS EVE...THE DEEPER VALLEYS
WILL OR ALREADY HAVE MANAGED TO DECOUPLE TONIGHT...WITH QUICKSAND
AND PAINTSVILLE MESONETS ALREADY DROPPING BELOW THE 60 DEGREE MARK
THIS HOUR. DID UPDATE GRIDS TO CAPTURE THIS A BIT EARLIER...BUT
OTHERWISE GRIDS REMAIN IN GOOD SHAPE.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM EST THU DEC 24 2015
19Z SFC ANALYSIS SHOWS A RELATIVE AREA OF HIGH PRESSURE OVER THE
OHIO VALLEY WHILE LOW PRESSURE IS BUILDING TO THE SOUTHWEST. ON
SATELLITE...A BRIEF PERIOD OF LOW CLOUDS AROUND MIDDAY HAVE
BROKEN UP AND SCATTERED OUT DURING THE EARLY AFTERNOON LEAVING
MOSTLY SUNNY CONDITIONS. THAT SUNSHINE...AND SOME LIMITED
DRYING...RESULTED IN TEMPERATURES SPIKING INTO THE UPPER 60S AND
LOWER 70S THROUGH EAST KENTUCKY THIS AFTERNOON. DEWPOINTS HAVE
FALLEN INTO THE LOW AND MID 50S..BUT ARE STILL VERY HIGH FOR THIS
TIME OF YEAR. MEANWHILE...WINDS ARE LIGHT AND VARIABLE THROUGH THE
AREA...GENERALLY FROM THE SOUTH FOR LOCATIONS SOUTH OF THE
MOUNTAIN PARKWAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE LONGWAVE PATTERN
AS THEY ALL SHOW THE SOUTHEAST RIDGE STRENGTHENING AND WOBBLING
WEST INTO FRIDAY WHILE LARGE AND FAIRLY STRONG TROUGHING DIVES
INTO THE DESERT SOUTHWEST. THIS WILL ALL SERVE TO STRENGTHEN THE
BROAD AND DEEP SOUTHWEST FLOW THROUGH THE REGION INTO SATURDAY
MORNING. WHILE THE MAJORITY OF THE ENERGY IN THIS PATTERN WILL
STAY WITH THE WESTERN TROUGH...THERE WILL BE A FEW WEAK WAVES THAT
RIDE OVER THE AREA DURING THE SHORT TERM PORTION OF THE FORECAST.
OF MOST SIGNIFICANCE WILL BE THE RECORD OR NEAR RECORD HIGH PW
AIR IN PLACE OVER THE REGION DURING THE DAY FRIDAY INTO
SATURDAY...THAT THE MODELS ARE PRETTY MUCH IN CONCURRENCE WITH.
AS SUCH...WILL FOLLOW A BLENDED MODEL SOLUTION FAVORING THE HIGHER
RESOLUTION HRRR AND NAM12 ALONG WITH INPUT FROM THE NATIONAL
CENTERS.
SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF OUR VERY WARM
HOLIDAY PERIOD WITH TEMPERATURES NOT FALLING TOO FAR INTO THE 50S
FOR MOST SPOTS TONIGHT. ALTHOUGH...AM EXPECTING A BIT OF A RIDGE
TO VALLEY TEMPERATURE SPLIT THIS EVENING AND INTO THE FIRST PART
OF THE OVERNIGHT. THIS SHOULD BE MOST NOTICEABLE IN THE FAR
EASTERN SHELTERED VALLEYS AND IS EXPECTED TO MIX OUT TOWARDS DAWN.
THE NEXT SURGE IN PCPN WILL LIKELY MOVE IN FROM THE SOUTHWEST
AROUND DAWN AS WELL AND OVERSPREAD THE ENTIRE CWA BY MID MORNING.
EXPECT LIGHT TO MODERATE SHOWERS ALONG WITH A POTENTIAL FOR
THUNDERSTORMS INTO THE DAY FRIDAY AS AN INVERTED TROUGH/SFC WAVE
MOVES THROUGH KENTUCKY. THIS WILL ACTIVATE THE HIGH MOISTURE
CONTENT IN PLACE AND COULD LEAD TO TRAINING ISSUES IN A FEW
SPOTS...PARTICULARLY THOSE THAT MAY HAVE SEEN SATURATING TO HEAVY
RAINS OVER THE PAST DAY OR SO. DO EXPECT THE HIGHEST RAINFALL
TOTALS THROUGH SATURDAY MORNING TO FALL OVER THE CUMBERLAND
VALLEY BEFORE THE RESPONSIBLE WAVE PULLS OUT OF THE AREA EARLY
SATURDAY. GIVEN THE POTENTIAL HAVE DECIDED TO ISSUE A FLOOD WATCH
STARTING AT 6 AM FRIDAY AND RUNNING THROUGH 8 AM SATURDAY...WITH
BETWEEN 1.5 AND 2.5 INCHES OF RAIN POSSIBLE DURING THIS TIME
FRAME. THIS WATCH WILL COVER POINTS GENERALLY SOUTH OF INTERSTATE
64. CONFIDENCE IS FAIRLY HIGH THAT A GOOD SWATH OF RAIN WILL FALL
OVER A GOOD PORTION OF THE CWA DURING THIS TIME...BUT LOW FOR ANY
PARTICULAR PLACEMENT GIVEN SOME DISCREPANCIES WITH THE HIGHEST
AXIS OF QPF FROM EACH MODEL. IN ADDITION...THE CONCERN FOR HEAVY
RAIN WILL RUN INTO THE NEW WEEK AND FOR THAT OVERARCHING RAINFALL
THREAT WILL ISSUE AN ESF.
FOR TEMPERATURES AND DEWPOINTS...HAVE MAINLY GONE WITH THE
SHORTBLEND GUIDANCE THROUGH FRIDAY MORNING AND THEN THE SUPERBLEND
INTO SATURDAY MORNING. DID MAKE SOME NEAR TERM ADJUSTMENTS INTO
THE FIRST PART OF THE NIGHT FOR A PARTIAL AND BRIEF RIDGE TO
VALLEY TEMPERATURE SPLIT. NOT EXPECTING MUCH OF A DIFFERENCE IN
TEMPS FRIDAY NIGHT GIVEN THE PCPN. AS FOR POPS...ENDED UP ON THE
HIGH SIDE OF GUIDANCE THROUGH THE PERIOD...ESPECIALLY TONIGHT AT
LOZ WHERE THE WETTER MET NUMBERS WERE PREFERRED.
WHILE RECORD HIGH MINIMUM TEMPERATURES ARE EXPECTED BOTH TONIGHT
AND FRIDAY NIGHT...HIGH TEMPERATURE RECORDS FOR TOMORROW WILL
LIKELY NOT FALL DUE TO A VERY WARM CHRISTMAS BACK IN 1982.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EST THU DEC 24 2015
THE MAIN CONCERN FOR THIS PERIOD WILL BE THE POTENTIAL FOR
REPEATING ROUNDS OF RAINFALL THROUGH EARLY NEXT WEEK WITH A DEEP
AND MOISTURE LADEN SOUTHWEST FLOW IN PLACE ALOFT. A WAVY FRONTAL
BOUNDARY WILL LIFT NORTHWARD ACROSS OUR AREA ON SATURDAY ALLOWING
FOR A BREAK IN THE RAINFALL FOR MOST OF EASTERN KENTUCKY FROM
SATURDAY AFTERNOON THROUGH SUNDAY MORNING. FOR THIS REASON...THE
FLOOD WATCH ISSUED WILL ONLY RUN THROUGH AROUND DAWN ON SATURDAY.
HOWEVER...DEEPENING LOW PRESSURE WILL DRIVE NORTHEASTWARD OUT OF
TEXAS LATE IN THE WEEKEND INTO THE DAY ON MONDAY AND THIS WILL
SEND THE FRONT AND A LOAD OF MOISTURE BACK ACROSS THE REGION
BEGINNING SUNDAY AFTERNOON AND LASTING THROUGH MONDAY NIGHT. A
COUPLE OF INCHES OF ADDITIONAL RAINFALL IS LIKELY DURING THIS SECOND
WAVE OF RAIN...WHICH WILL LIKELY CAUSE ADDITIONAL FLOOD CONCERNS.
THIS SYSTEM WILL EXIT TO OUR EAST WITH DIMINISHING RAIN CHANCES ON
TUESDAY.
THE OTHER STORY TO TOUCH ON IS THE UNSEASONABLE WARMTH. PROGGED
850 MB TEMPS ON SATURDAY OF AROUND 15C ARE CLOSE TO RECORD HIGHS
ACCORDING TO SPC SOUNDING CLIMATOLOGY. HIGH TEMPS ARE FORECAST TO
EASILY ECLIPSE RECORDS SATURDAY BY CLIMBING INTO THE LOW TO MID
70S. THIS MAY BE CONSERVATIVE IF CLOUDS SCATTER OUT FOR ANY LENGTH
OF TIME. TEMPS ON SUNDAY WILL AGAIN THREATEN RECORDS AS THEY CLIMB
TO AROUND 70 SOUTH OF I-64...BEFORE A COOLER BUT STILL ABOVE NORMAL
AIRMASS FILTERS IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK. IF
OUR FORECAST PANS OUT THROUGH DECEMBER 31ST...THIS WILL EASILY BE
THE WARMEST DECEMBER ON RECORD AT BOTH JKL AND LOZ. IN FACT...OUR
AVERAGE TEMPERATURE THIS DECEMBER AT JKL AND LOZ WILL LIKELY BE A
COUPLE DEGREES WARMER THAN THE AVERAGE NOVEMBER TEMPERATURE AT
THOSE SITES WHEN ALL IS SAID AND DONE!
BEYOND TUESDAY...FORECAST MODELS KEEP US IN SOUTHWEST FLOW ALOFT
WITH ANOTHER SHORTWAVE PROGGED TO BRING ANOTHER ROUND OF SHOWERS
WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY A RETURN TO MORE
SEASONAL TEMPERATURES BY NEW YEARS EVE.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 642 PM EST THU DEC 24 2015
VFR IS THE STORY TO BEGIN THE TAF PERIOD...BUT A FEW PASSING 2 TO
5 KFT CLOUDS WILL BE POSSIBLE PARTICULARLY IN THE SE. THEN EYES
WILL TURN TO A DEVELOPING STORM SYSTEM TO OUR SW. RAIN SHOWERS
AND THUNDERSTORMS WILL DEVELOP AND PROGRESS ACROSS EASTERN KY BY
TOMORROW MORNING AND CONTINUE THROUGH THE DAY. THE BEST CHANCES OF
RAIN AND STORMS WILL BE GENERALLY SOUTH OF SITE SYM...SO DID KEEP
THEM -SHRA VCTS BUT BRING -RA VCTS TO OTHER SITES. FORECAST
SOUNDINGS AND LAMP PROBS ALL SUGGEST LOWERING TO AT LEAST IFR CIGS
BY TOMORROW AFTERNOON SO ADDED THIS ACCORDINGLY. WINDS WILL REMAIN
LIGHT THROUGH THE TAF PERIOD GENERALLY 5 TO 10 KNOTS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM 6 AM EST FRIDAY THROUGH SATURDAY MORNING FOR
KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
UPDATE...DJ
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
455 AM EST FRI DEC 25 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 405 PM EST THU DEC 24 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WEST INTO THE CNTRL CONUS RESULTING IN SW FLOW FROM THE
PLAINS INTO THE CNTRL PLAINS TO THE NRN LAKES. A SHRTWV FROM SE SD
INTO WRN IA SUPPORTED AN AREA OF SNOW OVER IA. OTHERWISE...DRY
CONDITIONS PREVAILED FROM NRN MN THROUGH UPPER MI. WINDS HAVE
DIMINISHED THIS AFTERNOON AS THE PRES GRADIENT WEAKENS IN ADVANCE OF
HIGH PRES BUILDING TOWARD THE AREA FROM THE NRN PLAINS. EVEN WITH 850
MB TEMPS NEAR -10C...ONLY A FEW FLURRIES OBSERVED FOR WEST FLOW LES
AREAS AS INVERSION HEIGHTS HAVE DROPPED TO AROUND 3K-4K FT.
TONIGHT...WRLY FLOW WITH LOW LEVEL CONV WILL FAVOR CONTINUED CHANCE
OF LIGHT SNOW SHOWERS FOR THE KEWEENAW. HOWEVER...WITH THE TOP OF
THE CLOUD LAYER NEAR -10C...ICE NUCLEI MAY BE LACKING RESULTING
POTENTIAL FOR SOME FZDZ. OTHERWISE...WINDS WILL CONTINUE TO DIMINISH
WITH GRADUAL CLEARING OVER THE WEST HALF LATE TONIGHT. TEMPS SHOULD
DROP INTO THE UPPER TEENS TO LOWER 20S.
FRIDAY...THE RIDGE WILL BUILD INTO THE WRN LAKES WITH PARTLY TO
MOSTLY SUNNY SKIES. THE SUNSHINE WILL HELP PUSH TEMPS INTO THE 30 TO
35 RANGE...COLDEST OVER THE WEST WITH THE MOST SNOW COVER.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 455 AM EST FRI DEC 25 2015
THE MAIN FOCUS IS ON THE POTENTIAL FOR MODERATE SNOWFALL ACROSS THE
NORTHWEST HALF OF UPPER MI ON SATURDAY AND SATURDAY EVENING.
SATURDAY AND SATURDAY EVENING...THE PHASING OF A SHORTWAVE TROUGH
EJECTING FROM A LARGER TROUGH OVER THE SW STATES...AND ANOTHER
SHORTWAVE TROUGH DIGGING SE FROM BRITISH COLUMBIA...WILL BE STARTING
ACROSS THE UPPER AND MID MS VALLEY SAT MORNING. AHEAD OF THESE
TROUGHS...MODEST ISENTROPIC LIFT ON THE 290 TO 300K THETA SURFACES
UNDER SLOPING MID-LEVEL FGEN AND THE RIGHT ENTRANCE OF A
STRENGTHENING UPPER JET STREAK WILL SUPPORT MODERATE SNOW ACROSS THE
NW HALF OF THE CWA FROM AROUND DAYBREAK SATURDAY INTO SATURDAY
EVENING. THE BEST LIFT FROM WAA/ISENTROPIC ASCENT AND THE ACTIVE MID-
LEVEL FGEN WILL BE SOMEWHAT DISCONNECTED...RESULTING IN THE
POTENTIAL FOR A LOCALLY HEAVY SNOW BAND EMBEDDED WITHIN MORE
WIDESPREAD LIGHT TO MODERATE SNOW FOR ALL BUT THE EASTERN CWA. MODEL
GUIDANCE HAS BEEN MOVING AROUND THE BAND OF HEAVIER PRECIP...SO
PEGGING THE LOCATION WITH HIGHEST SNOW AMOUNTS REMAINS A CHALLENGE.
WITH THAT SAID...HIGH RES GUIDANCE IS WIDELY SUPPORTING A NARROW
COUNTY-WIDE SWATH OF 0.5 TO 0.7 INCHES OF PRECIP FROM 12Z SAT TO 06Z
SUNDAY. WITH A DEEP DGZ LOCATED WITHIN THE ACTIVE FGEN LAYER...SNOW
RATIOS SHOULD BE RATHER HIGH AT AROUND 17 OR 18 TO 1. AWAY FROM THE
MAIN FGEN BAND...RATIOS WILL BE CLOSER TO 14 OR 15 TO 1. PUTTING
THIS ALL TOGETHER...CHANCES LOOK FAIRLY GOOD FOR A SOLID 3 TO 6
INCHES OF SNOW FOR THE NW HALF OF THE CWA...WITH THE POTENTIAL FOR A
NARROW BAND OF UP TO 9 INCHES. THIS IS ESPECIALLY TRUE IF THE BAND
ALIGNS WITH LOW-LEVEL NE UPSLOPE ACROSS THE NORTH CENTRAL.
GIVEN THE RATHER LOW CONFIDENCE ON BAND PLACEMENT...INCLUDING THE
POTENTIAL FOR THE BAND TO REMAIN OVER LAKE SUPERIOR...AND GIVEN THAT
THE MAIN SNOW IS STILL GREATER THAN 30 HOURS OUT...HAVE OPTED TO
ISSUE A SPS FOR THE NW HALF HIGHLIGHTING THE SNOW ALONG WITH MINOR
POST-HOLIDAY TRAVEL DISRUPTIONS.
REST OF THE PERIOD...LIGHT TO SOMETIMES MODERATE LES WILL LINGER
ALONG LAKE SUPERIOR THROUGH SUNDAY NIGHT FOR THE N AND NW WIND
SNOWBELTS AS -15 TO -20C H8 AIR FILTERS OVER LAKE SUPERIOR ON
SUNDAY. GENERALLY SHALLOW INVERSIONS AT OR LESS THAN 4KFT WILL
HINDER OVERALL LES INTENSITY. BUT WITH THE CLOUD LAYER COMPLETELY
WITHIN THE DGZ AT TIMES...VERY FLUFFY SNOW CAN BE EXPECTED. IF
CLOUDS CAN CLEAR ENOUGH SUNDAY NIGHT...TEMPS MAY FALL TO NEAR ZERO
ACROSS THE INTERIOR WEST WHERE FRESH SNOW HAS FALLEN.
LOTS OF UNCERTAINTY AS THE UPPER LOW THAT WILL FORM OVER THE
U.S./MEXICO BORDER LOOKS TO BREAK DOWN AND SHIFT THROUGH THE REGION
TUE INTO TUE NIGHT. OVERALL GUIDANCE CONTINUES TO KEEP THE MAIN
TROUGH TO THE SE OF THE CWA ON TUESDAY...WITH THE ECMWF REMAINING
THE OUTLIER BY BRINGING THE TROUGH NEAR UPPER MI. WILL CONTINUE TO
HEDGE TOWARD A DRIER SOLUTION...WITH LES POSSIBLE FOR THE EAST WIND
SNOW BELTS OF LAKE SUPERIOR AND LAKE MI.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1205 AM EST FRI DEC 25 2015
ENOUGH LOW LEVEL MOISTURE WILL LINGER TO SUPPORT MARGINAL VFR CIGS
AT IWD AND MVFR CIGS AT CMX AND SAW THROUGH MUCH OF THE NIGHT.
CONDITIONS AT IWD AND SAW WILL IMPROVE TO VFR DURING THE MORNING
WHILE CMX REMAINS MVFR TIL MIDDAY WITH UPSLOPE WESTERLY FLOW
CONTINUING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EST THU DEC 24 2015
AS HIGH PRESSURE BUILDS TOWARD THE REGION THIS
EVENING...WINDS WILL DROP BELOW GALE FORCE. HIGH PRESSURE BUILDS
ACROSS THE LAKE FOR CHRISTMAS DAY BEFORE ANOTHER LOW MOVES ACROSS
THE SOUTHERN GREAT LAKES SATURDAY NIGHT. STRONGER HIGH PRESSURE IS
EXPECTED TO BUILD ACROSS THE UPPER GREAT LAKES SUNDAY INTO MONDAY.
AFTER TONIGHT...WINDS SHOULD STAY BELOW 30KT ACROSS LAKE SUPERIOR
THROUGH MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...MZ
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1206 AM EST FRI DEC 25 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 405 PM EST THU DEC 24 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WEST INTO THE CNTRL CONUS RESULTING IN SW FLOW FROM THE
PLAINS INTO THE CNTRL PLAINS TO THE NRN LAKES. A SHRTWV FROM SE SD
INTO WRN IA SUPPORTED AN AREA OF SNOW OVER IA. OTHERWISE...DRY
CONDITIONS PREVAILED FROM NRN MN THROUGH UPPER MI. WINDS HAVE
DIMINISHED THIS AFTERNOON AS THE PRES GRADIENT WEAKENS IN ADVANCE OF
HIGH PRES BUILDING TOWARD THE AREA FROM THE NRN PLAINS. EVEN WITH 850
MB TEMPS NEAR -10C...ONLY A FEW FLURRIES OBSERVED FOR WEST FLOW LES
AREAS AS INVERSION HEIGHTS HAVE DROPPED TO AROUND 3K-4K FT.
TONIGHT...WRLY FLOW WITH LOW LEVEL CONV WILL FAVOR CONTINUED CHANCE
OF LIGHT SNOW SHOWERS FOR THE KEWEENAW. HOWEVER...WITH THE TOP OF
THE CLOUD LAYER NEAR -10C...ICE NUCLEI MAY BE LACKING RESULTING
POTENTIAL FOR SOME FZDZ. OTHERWISE...WINDS WILL CONTINUE TO DIMINISH
WITH GRADUAL CLEARING OVER THE WEST HALF LATE TONIGHT. TEMPS SHOULD
DROP INTO THE UPPER TEENS TO LOWER 20S.
FRIDAY...THE RIDGE WILL BUILD INTO THE WRN LAKES WITH PARTLY TO
MOSTLY SUNNY SKIES. THE SUNSHINE WILL HELP PUSH TEMPS INTO THE 30 TO
35 RANGE...COLDEST OVER THE WEST WITH THE MOST SNOW COVER.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM EST THU DEC 24 2015
THE PHASING OF A COUPLE PIECES OF UPPER LEVEL ENERGY WILL RESULT IN
SOME LIGHT TO POTENTIALLY MODERATE SNOW AT TIMES OVER MUCH OR ALL OF
THE CWA LATE FRI NIGHT UNTO EARLY SAT NIGHT BEFORE TRANSITIONING TO
LES. MODELS CONTINUE TO TREND NW WITH THE HEAVIEST QPF/SNOW...SO
WILL CONTINUE SHOWING THAT TREND IN THE FORECAST. ALSO...MODELS ARE
NOT IN COMPLETE AGREEMENT ON PRECIP AMOUNTS...SO THERE REMAINS SOME
UNCERTAINTY THERE AS WELL. AT THIS POINT...EXPECT GREATEST SNOWFALL
FROM NCENTRAL UPPER MI...WHERE WINDS WILL TURN OUT OF THE NE ON SAT
PROVIDING UPSLOPE FORCING...TO THE KEWEENAW AND WRN UPPER MI. HAVE 3-
5 INCHES IN THESE AREAS...WITH LOWER AMOUNTS TO THE S AND E. BLOWING
SNOW WILL BE ON THE INCREASE NEAR LAKE SUPERIOR ON SAT AS WIND GUSTS
INCREASE TO 25-30MPH AND BECOME NORTHERLY.
THE WINDS WILL CARRY MUCH COLDER AIR AS AN UPPER TROUGH DROPS
THROUGH SAT NIGHT INTO SUN MORNING. 850MB TEMPS WILL DROP FROM
AROUND -8C AT 00Z SUN TO BETWEEN -15C AND -20C LATE SUN INTO SUN
NIGHT. WINDS WILL BE OUT OF THE NW UNTIL AFTER 00Z MON WHEN WINDS
WILL TURN N-NNE...THEN OUT OF THE E MON MORNING AS A HIGH PASSES N
OF THE AREA. MOST OF THIS TIME WILL SEE INVERSION HEIGHT AROUND
4KFT...WITH GOOD SNOW RATIOS...BUT A SHORTWAVE MAY MOVE THROUGH SUN
EVENING THAT WOULD BRING A HEAVIER BURST OF SNOW AS THE WINDS TURN
MORE N-NNE. OVERALL GOOD CONFIDENCE OF LIGHT TO OCCASIONALLY
MODERATE LES AND PATCHY BLOW SNOW IN NW WIND SNOWBELTS...BECOMING N-
NNE SNOW BELTS LATE SUN INTO MON MORNING. THIS SHOULD RESULT IN
SEVERAL INCHES OF SNOW DURING THIS PERIOD. WILL INCREASE
QPF/SNOWFALL AMOUNTS AND POPS.
FOR NEXT WEEK...LOTS OF UNCERTAINTY AS THE UPPER LOW THAT WILL FORM
OVER THE U.S./MEXICO BORDER LOOKS TO BREAK DOWN AND SHIFT THROUGH
THE REGION TUE INTO TUE NIGHT. THERE ARE A LOT OF VARIABLES WITH
SNOWFALL FORECAST FOR THAT TIME...BUT THE OVERALL APPEARANCE IS THAT
A MAJOR PATTERN CHANGE MAY OCCUR. MODELS SHOW THE LONGWAVE UPPER
TROUGH THAT HAS BEEN OVER THE WRN CONUS SHIFTING TO THE ERN
CONUS...WITH COLDER AIR AND MORE ACTIVE WEATHER THE GENERAL THEME.
STAY TUNED TO LATER FORECASTS FOR DETAILS NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1205 AM EST FRI DEC 25 2015
ENOUGH LOW LEVEL MOISTURE WILL LINGER TO SUPPORT MARGINAL VFR CIGS
AT IWD AND MVFR CIGS AT CMX AND SAW THROUGH MUCH OF THE NIGHT.
CONDITIONS AT IWD AND SAW WILL IMPROVE TO VFR DURING THE MORNING
WHILE CMX REMAINS MVFR TIL MIDDAY WITH UPSLOPE WESTERLY FLOW
CONTINUING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EST THU DEC 24 2015
AS HIGH PRESSURE BUILDS TOWARD THE REGION THIS
EVENING...WINDS WILL DROP BELOW GALE FORCE. HIGH PRESSURE BUILDS
ACROSS THE LAKE FOR CHRISTMAS DAY BEFORE ANOTHER LOW MOVES ACROSS
THE SOUTHERN GREAT LAKES SATURDAY NIGHT. STRONGER HIGH PRESSURE IS
EXPECTED TO BUILD ACROSS THE UPPER GREAT LAKES SUNDAY INTO MONDAY.
AFTER TONIGHT...WINDS SHOULD STAY BELOW 30KT ACROSS LAKE SUPERIOR
THROUGH MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...MZ
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1150 PM CST THU DEC 24 2015
.SHORT TERM: (Through Late Tonight)
Issued at 342 PM CST Thu Dec 24 2015
Low-mid level WAA and MCON along with frontogenetic forcing resulted
in an elongated region of light rain earlier today across central
and northeast MO. This regime is occurring in advance of a low-
amplitude disturbance which is dampening and now located in western
MO. Overall forcing has diminished and shifted to the northeast of
the CWA and only a narrow elongated ribbon of light rain still
persists in west central IL. Present indications is this will also
diminish and shift to the northeast the remainder of the afternoon
and early evening as the disturbance aloft and associated surface
cold front push east. There are some indications in the HRRR and GFS
that a new narrow band of precipitation may try to develop this
evening somewhere in the SE/EC MO into SW IL region in response to a
new region of low level MCON. I have add a slight chance of light
rain in SW IL this evening to account for this and some sprinkles
further west. Otherwise expecting several waves of clouds tonight
with current mid clouds and maybe a period of low clouds up north.
SREF probs and HRRR also suggesting some potential for fog from
across northern/central MO into western IL overnight. I added a
mention of patchy fog in this region, but the overall pattern in
post-frontal air mass with building surface high pressure is at
first glance not one typically associated with a lot of fog.
Glass
.LONG TERM: (Friday through Next Thursday)
Issued at 342 PM CST Thu Dec 24 2015
(Friday)
Overall, it looks like a fairly tranquil Christmas Day across the
area. Models continue to hint at WAA along the stalled frontal
boundary to our south generating an axis of convection from AR into
the lower Ohio Valley, with our far southern counties on the very
northern fringes of this activity. The 12z solutions have the axis
of this activity just south of our area, but since the last few
model cycles have wobbled a bit with the north/south placement of
this precip, I`ve maintained some very low PoPs over our far
southern counties.
Otherwise, it still appears tranquil conditions are on tap for the
region, with temperatures maintaining the very mild levels that have
been commonplace this December. Highs are expected to range from
the middle and upper 40s northwest, to the middle 50s southeast.
Concern then turns to the long-advertised heavy rain threat for the
upcoming weekend and into early next week. Due to some uncertainty
to the placement of the heaviest rain have opted not to go with any
hydro headlines...yet. However, will be reissuing the EFP to
maintain awareness of the threat, which should come in two waves as
described below.
(Saturday Through Monday Night)
The long-advertised spell of wet weather should commence in earnest
either late Friday night or Saturday. Deep southerly flow is
expected to develop across the region in response to the upper level
system digging into the southwest US, and resultant isentropic
ascent over the area should be quite strong with the stalled frontal
boundary and low level baroclinic zone just to our south. In
addition, UVV across the area will be enhance by several weak
shortwaves ejecting ahead of the main system. Moisture should be no
problem as airmass will essentially be the same one that fueled
yesterdays storms in our area, with the increasing southerly flow
adding even more moisture to the unseasonably moist December
airmass. Again, models are wobbling a bit with the exact location of
the axis of the heaviest precip, but they are in excellent agreement
with the general idea that several rounds of convection will track
along and north of the frontal boundary as it attempts to push
north...from eastern OK into s MO and s IL...in the Saturday and
Saturday night time.
It appears that this first round of significant rain will wind down
on Sunday as shortwave in the northern branch of the westerlies
allows Canadian high to drop south, temporarily shutting down the
warm advection and nudging the frontal boundary back south.
Final wave of potentially heavy rain should impact the region on
Monday and Monday night as upper level low lifts out of Texas and
pushes northeast into the mid-Mississippi Valley. Again, moisture-
laden AMS ans strong UVV should produce another band of moderate to
occasionally heavy rain...with embedded thunderstorms...that will
sweep across the area.
It`s not totally out of the question that we could see a bit of
wintry precip Sunday night-Monday night. First concern will be late
Sunday night and into early Monday as surface temps drop below
freezing with the southward surge of the Canadian high...while AMS
aloft remains well above freezing. This threat should be brief and
on the northern fringes of the heavier rainfall...and with the very
warm ground temperatures am not expecting much of an impact from
this. The second concern will be Monday night as the upper low
pushes across the area. It`s possible that the dropping freezing
levels beneath the low could cause the rain to change over to snow,
but not certain if the lower levels will cool enough for any
prolonged period of significant snowfall.
(Tuesday-Thursday)
Medium range progs suggest long wave trof will be parked over the
central CONUS during this time frame. This will finally allow
Canadian air to dominate the region, which should yield more normal
typical wintertime temperatures.
Best holiday wishes to all...from the day shift of the National
Weather Service in St. Louis.
Truett
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1133 PM CST Thu Dec 24 2015
Weak cold front/wind shift pushed thru the terminals this evng
turning wind W/NW. SFC ridge drifts from IA tonight to the Grt
Lks by the end of the prd which allows winds to slowly back
overnight eventually bcmng erly by Fri. There have been some
scttrd sprinkles across e cntrl/SE MO into sthrn IL this evng and
these should continue for the next several hours until the forcing
moves east. For tonight...there is an area of IFR CIGs across s
cntrl IA that some guidance has making a SE push for several hours
after midnight which brings the edge of the CIGs very close to
UIN. Not confident enough in this solution to include attm but
this will have to be monitored overnight for possible updates.
Even though the set up is not ideal for fog formation...guidance
continues to indicate that at least some patchy fog may dvlp
towards mrng across cntrl/NE MO into w cntrl IL. Not confident in
this scenario either but not sure enough that it won`t happen to
pull it from the going fcst. Otherwise expect mid/high clouds.
Specifics for KSTL:
VFR fcst thru the prd. Scttrd sprinkles across the STL metro
should continue for the next couple of hours until the forcing
exits east. Winds will slowly back to the east by tomorrow as high
pressure drifts from IA to the Grt Lks. MVFR CIGs may try to
encroach upon the terminal from the south late Friday night. But
since guidance indicates that if it were to happen it would be
drng the last 3 hrs of the fcst prd and of sufficiently low
confidence to preclude inclusion attm.
2%
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 39 54 47 63 / 10 5 20 100
Quincy 32 48 42 54 / 5 5 10 70
Columbia 33 52 45 59 / 5 5 20 80
Jefferson City 33 53 46 60 / 5 5 20 90
Salem 40 56 49 64 / 20 5 40 90
Farmington 39 54 49 64 / 20 10 50 100
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Flash Flood Watch from Saturday morning through late Monday
night FOR Crawford MO-Franklin MO-Gasconade MO-Iron MO-
Jefferson MO-Madison MO-Osage MO-Reynolds MO-St. Charles MO-
St. Francois MO-St. Louis City MO-St. Louis MO-Ste.
Genevieve MO-Warren MO-Washington MO.
IL...Flash Flood Watch from Saturday morning through late Monday
night FOR Bond IL-Clinton IL-Fayette IL-Madison IL-Marion
IL-Monroe IL-Randolph IL-St. Clair IL-Washington IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
351 AM CST FRI DEC 25 2015
.SYNOPSIS...
ISSUED AT 349 AM CST FRI DEC 25 2015
AT H5 TROUGH DEEPENING OVER THE WESTERN CONUS, STRONG BERMUDA
HIGH TO THE EAST WITH SOUTHWEST TO NORTHEAST FLOW FROM DESERT
SOUTHWEST TO THE NORTHEAST CONUS. AT THE SURFACE COLD FRONTAL
BOUNDARY FROM MAINE TO NEW YORK TO KENTUCKY THEN SOUTHWEST TO THE
TEXAS COAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 349 AM CST FRI DEC 25 2015
MODELS IN FAIR AGREEMENT IN THE NEAR TERM AND WILL USE A BLEND
FOR THE FORECAST. STRONG 130KT+JET DIGGING TROUGH TO THE WEST
FAIRLY PROGRESSIVE PATTERN. MAIN ENERGY MOVING THROUGH THE 4
CORNERS BY 18Z WITH DIFFLUENCE ALOFT OVER WESTERN NEBRASKA AND
STRONG WAA AND MOISTURE ADVECTION INTO WESTERN NEBRASKA. BUFKIT
SOUNDINGS INDICATING SOME PATCHY FREEZING DRIZZLE INITIALLY WITH
MOIST LOWER LAYER AND DRY AIR ABOVE. STRONG SOUTH TO SOUTHEAST
FLOW INITIALLY BECOMING EAST THROUGH THE DAY. HAVE SKEWED THE
TEMPERATURE FORECAST AGAIN TO THE SNOWLESS GROUND BUT TAKING INTO
ACCOUNT SNOW TO THE SOUTHEAST HAVE KEPT HIGHS MAINLY AROUND
FREEZING WITH UPPER 20S OVER SHERIDAN AND WESTERN CHERRY COUNTIES
AND SOME MID 30S OVER THE SOUTHWEST. 1036MB SURFACE HIGH PUSHING
COLD FRONT INTO NORTHWEST NEBRASKA THIS AFTERNOON AND ACROSS THE
FORECAST AREA OVER NIGHT. SURFACE LOW OVER WESTERN KANSAS
SHIFTING EAST OVER NIGHT WITH STRONG UPGLIDE AND FORCING ALONG
THE COLD FRONT AS IT MOVES SOUTH. PERIODS OF BLOWING SNOW AS THE
WINDS SHIFT TO THE NORTH OVER MAINLY NORTHERN NEBRASKA. CONTINUE
WARNING AND ADVISORY. APPARENT TEMPERATURES FALLING TO BELOW ZERO
SATURDAY MORNING.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 349 AM CST FRI DEC 25 2015
DAYTIME SATURDAY THE WINTER STORM WILL BEGIN TO LIFT TO THE NORTH
OF THE AREA. DURING THE MORNING HOURS...MOST AREAS TO CONTINUE TO
SEE SNOW...ALBEIT LIGHT ACROSS SW NEB. FOR THE AFTERNOON SHOULD
SEE THE SNOW ENDING FROM SW TO NE. WILL NOT CHANGE THE ENDING
TIME FOR THE ADVISORY HOWEVER THE SYSTEM IS A LITTLE FASTER THIS
MORNING AND WOULD NOT BE SURPRISE IF MUCH OF THE ADVISORY DOES NOT
SEE ANY ACCUMULATION DURING THE AFTERNOON. TEMPS WARMEST IN THE
MORNING...THEN AS COLD AIR ADVECTION CONTINUES...FALLING TEMPS
LIKELY. MORNING TEMPS IN THE TEENS TO MID 20S...THEN FALLING INTO
THE SINGLE DIGITS AND TEENS BY THE AFTERNOON. CLEARING SATURDAY
NIGHT AS HIGH PRESSURE BUILDS ACROSS THE AREA. THIS WILL CONTINUE
TO CAUSE TEMPS TO FALL. COLDEST ACROSS THE HEAVIER SNOW PACK WITH
TEMPS WELL BELOW ZERO. IF WINDS GO CALM EARLIER ENOUGH IN THE
NIGHT...FAVORED COLD SPOTS ACROSS NW NEB COULD BOTTOM OUT AT 10
TO 20 BELOW. SUNDAY SHOULD BE MOSTLY SUNNY BUT CHILLY WITH HIGHS
STRUGGLING INTO THE 20S.
EYES THEN FOCUS ON THE UPPER LOW AS IT PUSHES ACROSS THE SOUTHERN
ROCKIES AND TRACKS TO THE NORTHEAST EARLY NEXT WEEK. THE GFS IS
THE FURTHEST TO THE SOUTH WHILE THE NAM IS THE FURTHEST TO THE
NORTH...AND STRONGEST WITH THE LOW. IN THE MIDDLE OF THE TWO IS
THE ECMWF SOLUTION. THE GFS IS STRONGER WITH THE HIGH PRESSURE
ACROSS THE NORTHERN PLAINS AND KEEPS THE STORM SYSTEM WELL EAST
OF THE CWA. THE EC HAS A STRONGER SYSTEM AND DRAWS IT FURTHER TO
THE NW...WHICH BRINGS SOME WRAP AROUND INTO WESTERN NEB. THIS IS
SIMILAR TO WHAT I SAW YESTERDAY MORNING SO WILL STAY THE COURSE
WITH THE FORECAST AND CHANGE LITTLE TO THE LOW POPS.
A CLIPPER SYSTEM WILL WORK ACROSS THE AREA MID WEEK. MOISTURE
WILL BE TOP DOWN AND SYSTEM IS FAIRLY PROGRESSIVE. COULD SEE SOME
LIGHT SNOW WITH THE SYSTEM...ALTHOUGH LOW CONFIDENCE ON TIMING
UNTIL BETTER AGREEMENT WITH THE SYSTEM EARLIER IN THE WEEK.
TEMPS FOR THE LAST WEEK OF 2015 WILL BE BELOW NORMAL...AND WELL
BELOW NORMAL ACROSS NW NEB WITH A DEEPER SNOW PACK EXPECTED.
HIGHS GENERALLY IN THE 20S WITH LOWS DOWN TO THE SINGLE DIGITS TO
TEENS ABOVE ZERO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM CST THU DEC 24 2015
THE RAP AND NAM ARE PRETTY CLOSE WITH VFR OVERNIGHT THROUGH AT
LEAST 18Z FRIDAY. THEREAFTER IFR/LIFR IN SNOW AND LOW CIGS SHOULD
INFILTRATE WRN NEB AND SPREAD NORTHEAST TOWARD KVTN BY 00Z FRIDAY
EVENING. AT 00Z...IFR/LIFR IN LIGHT SNOW...FREEZING DRIZZLE
BECOME WIDESPREAD ALONG I-80. SNOW SHOULD BE WIDESPREAD ALONG AND
NORTH OF NEBRASKA HIGHWAY 2 AT THIS SAME TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 6 PM CST /5 PM MST/ THIS EVENING TO 6
PM CST /5 PM MST/ SATURDAY FOR NEZ004>006-094.
WINTER WEATHER ADVISORY FROM 6 PM CST /5 PM MST/ THIS EVENING TO
6 PM CST /5 PM MST/ SATURDAY FOR NEZ007>010-022>028-035>038-056-
057-059.
&&
$$
SYNOPSIS...POWER
SHORT TERM...POWER
LONG TERM...MASEK
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1118 PM CST THU DEC 24 2015
.SYNOPSIS...
ISSUED AT 333 PM CST THU DEC 24 2015
H5 ANALYSIS FROM THIS MORNING HAD A LONGWAVE TROUGH OF
LOW PRESSURE ACROSS THE WESTERN 2/3RDS OF THE CONUS. A RIDGE EXTENDED
UP THE EAST COAST OF THE US WITH A VERY STRONG BERMUDA HIGH NOTED AT
5940 GPM. A DISTURBANCE WAS NOTED OVER CENTRAL NEBRASKA WITH A
SECOND EMBEDDED SHORTWAVE NOTED OFF THE COAST OF WASHINGTON STATE.
THE FIRST DISTURBANCE HAS MOVED QUICKLY EAST INTO IOWA THIS
MORNING...SPREADING SNOW ACROSS SOUTHERN AND EASTERN NEBRASKA. THE
SECOND DISTURBANCE CONTINUES TO INTENSIFY AS IT DIVES SOUTH
SOUTHEAST INTO WESTERN OREGON. AT THE SURFACE...WEAK HIGH PRESSURE
EXTENDED FROM NORTHWESTERN KS INTO SOUTH CENTRAL NEBRASKA WESTERLY
WINDS HAVE DEVELOPED ON THE NORTHERN PERIPHERY OF THIS SYSTEM. WITH
MANLY CLEAR SKIES AND FULL SUN...TEMPERATURES THIS AFTERNOON HAVE
REACHED THE MID TO UPPER 30S...WITH SOME LOWER 30S IN SNOW COVERED
AREAS OF NORTH CENTRAL AND NORTHWESTERN NEBRASKA.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 333 PM CST THU DEC 24 2015
PRECIPITATION CHANCES AND ASSOCIATED PTYPE ARE THE PRIMARY FORECAST
CONCERNS GOING IN THE SHORT TERM. THE SHORT TERM FORECAST MODELS
CONTINUE TO DISPLAY MODEST DISCREPANCY CONCERNING THE MESOSCALE
FEATURES WHICH WILL GREATLY INFLUENCE QPF AMOUNT...PRECIP
TYPE...TIMING AND LOCATION THROUGH 00Z SATURDAY. WITH THAT BEING
SAID...THE CONSENSUS INDICATES THAT MOST LOCATIONS WILL NOT SEE
ACCUMULATING QPF UNTIL AFTER 12Z CHRISTMAS DAY. THEN...THE MODELS
DIVERGE...BUT THE GENERAL IDEA IS THAT A SHORTWAVE WILL ENHANCE MID-
LEVEL FRONTOGENESIS AND FOCUS A BAND OF QPF WHICH SHOULD FALL AS ALL
SNOW. ALSO SUGGESTED BY THE SHORT TERM MODELS IS A CONVECTIVE
ELEMENT WHICH WOULD FOCUS HEAVIER SNOW AMOUNTS FURTHER. AT THIS
POINT A GENERAL BLEND OF THE AVAILABLE MODELS WOULD INDICATE A
PERIOD OF LIGHT QPF ACROSS MUCH OF THE CWA UP UNTIL 00Z
SATURDAY...WITH THE HEAVIEST QPF COMING BEYOND THE SHORT TERM. WILL
CAP SNOW ACCUMULATIONS AT AN INCH OR LESS THROUGH THE SHORT TERM
/THROUGH TOMORROW/ AND NOTE NOT ALL AREAS WILL SEE SNOW ON
CHRISTMAS. OTHERWISE THE TRACK OF THE SHORTWAVE AND THE PARENT UPPER
WAVE WILL DIRECT DRY MID-LEVEL AIR ACROSS OUR SOUTHERN AND
SOUTHEASTERN ZONES BEGINNING AROUND 18-00ZZ FRIDAY. THIS MAY
PROMOTE SOME FREEZING DRIZZLE. ONCE AGAIN HOWEVER...THE GREATER
THREAT OF ACCUMULATIONS WILL COME BEYOND THE SHORT TERM PERIOD.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 333 PM CST THU DEC 24 2015
FRIDAY NIGHT THROUGH SUNDAY...IN THE MID RANGE A LEAD
DISTURBANCE IS EXPECTED TO SPREAD SNOW AND A MIXTURE OF FREEZING
PRECIPITATION TO WESTERN AND NORTH CENTRAL NEBRASKA AND WILL BE THE
MAIN FORECAST CHALLENGE. FOR FRIDAY NIGHT...A POWERFUL TROUGH OF LOW
PRESSURE WILL DEEPEN ACROSS THE SWRN CONUS AS A 130 KT JET STREAK
DIVES SOUTH ALONG THE WEST COAST OF THE CONUS. A PIECE OF THIS
SYSTEM WILL APPROACH THE FORECAST AREA LATE FRIDAY AFTERNOON. MID
LEVEL FRONTOGENESIS WILL INCREASE QUICKLY OVER NORTHERN NEBRASKA
LEADING TO ACCUMULATING SNOWS OVER THE NORTHERN 2/3RDS OF THE
FORECAST AREA. THE MODELS HAVE TRENDED SLIGHTLY FARTHER NORTH WITH
THE BAND OF HEAVIEST PCPN IN ASSOCIATION WITH THIS SYSTEM...FAVORING
NORTHERN NEBRASKA AND SRN SD. GOOD MODEL AGREEMENT IS NOTED THIS
MORNING WITH THE EXCEPTION OF THE NAM SOLN WHICH HAS A MORE SRN
BIAS...AND MAY BE CONVECTIVE INFLUENCED. SUPPORT FOR THIS
CONVECTIVE INFLUENCE LIES WITH SOME ELEVATED NEGATIVE LI`S AND A
LITTLE BIT OF ELEVATED CAPE WHICH SHOWED UP IN THE 12Z NAM RUN. THAT
BEING SAID...FORECAST WAS TRENDED TOWARD THE GFS...SREF AND ECMWF
SOLNS WHICH FAVORED A MORE NORTHERN SOLUTION WITH THEIR MID LEVEL
FORCING. FURTHER SOUTH ALONG THE INTERSTATE 80 CORRIDOR INTO
PORTIONS OF CENTRAL NEBRASKA. FCST SOUNDING DATA IS INDICATIVE OF A
PROLONGED PERIOD OF FREEZING DRIZZLE. THIS IS DUE TO A WARM TONGUE
OF AIR AROUND H85 WHICH WORKS INTO SWRN AND SOUTH CENTRAL NEBRASKA
FRIDAY EVENING. BUFKIT SOUNDINGS...BOT THE GFS AND NAM SOLNS ARE
INDICATIVE OF A NICE LAYER OF LIFT CO LOCATED WITH SATURATION IN THE
LOWEST 100 MB OF THE SFC. BOTH SOLNS HAVE A BRIEF...MOIST DENDRITIC
LAYER EARLY FRIDAY EVENING...BUT SOON DRY THIS LAYER OUT BY LATE
EVENING. WITH THIS IN MIND...WE COULD SEE A MIX OF SNOW WITH A
CHANGEOVER TO FZ DRIZZLE AS THE DENDRITIC LAYER DRIES UP. FURTHER
NORTH...A NICE SATURATED DENDRITIC LAYER IS NOTED FROM THE SANDHILLS
NORTH INTO NORTH CENTRAL NEBRASKA. LIFT IS STRONGEST ACROSS FAR NRN
NEBRASKA AS WELL AS MOST PERSISTENT... SO HAVE PLACED THE HIGHEST
ACCUMULATIONS ALONG THE HIGHWAY 20 AND HIGHWAY 12 CORRIDORS FROM HAY
SPRINGS TO SPRINGVIEW. ACCUMULATIONS OF 4 TO 7 INCHES IS PROBABLE IN
THESE AREAS AND WILL HOIST A WINTER STORM WARNING FROM SHERIDAN
COUNTY EAST TO KEYA PAHA COUNTY. WINDS WILL BE ON THE ORDER OF 10 TO
20 MPH FRIDAY NIGHT...WHICH MAY FACILITATE SOME BLOWING AND DRIFTING
OF SNOW. FURTHER SOUTH...DECIDED TO HOIST A WINTER WEATHER
ADVISORY...FOR SNOW ACCUMULATIONS IN THE EAST CENTRAL PANHANDLE...AS
WELL AS THE SAND HILLS FOR SNOW OF 2 TO 4 INCHES AND ALONG THE
INTERSTATE 80 CORRIDOR INTO CUSTER COUNTY FOR THE POTENTIAL FOR
ACCUMULATING FREEZING DRIZZLE. REALIZE SNOW ACCUMS AND POTENTIAL ICE
ACCUMULATIONS ARE FAIRLY MARGINAL IN THE ADVISORY AREA...BUT WE ARE
HEADING INTO A HEAVY TRAVEL WEEKEND. ON SATURDAY...SNOW WILL
CONTINUE IN THE MORNING...TAPERING OFF DURING THE AFTERNOON HOURS.
DECIDED TO KEEP THE ADVISORY GOING THROUGH 00Z SUNDAY AS SOME
BLOWING SNOW ISSUES MAY CONTINUE THROUGH SUNSET SATURDAY
AFTERNOON...BEFORE WINDS DECOUPLE. SKIES WILL CLEAR OVERNIGHT
SATURDAY NIGHT AND WITH FRESH SNOW COVER AND LIGHT WINDS...TEMPS WILL
BE VERY CHILLY...ESPECIALLY OVER NORTHWESTERN PORTIONS OF THE
FORECAST AREA WHERE FCST LOWS ARE WELL BELOW ZERO. CONDITIONS WILL
BE QUIET FOR SUNDAY...ALBEIT COLD AS HIGH PRESSURE ANCHORS ITSELF
OVER WESTERN AND NORTH CENTRAL NEBRASKA. HIGHS WILL BE IN THE 20S
WITH SOME UPPER TEENS OVER NORTHERN NEBRASKA.
.LONG RANGE...SUNDAY NIGHT THROUGH THURSDAY...THE MAIN UPPER LEVEL
LOW WILL LIFT ACROSS TEXAS INTO THE OZARKS SUNDAY NIGHT THROUGH
MONDAY...BECOMING NEGATIVELY TILTED OVER MISSOURI MONDAY NIGHT.
LIGHT SNOW ON THE WESTERN PERIPHERY OF THIS SYSTEM MAY WORK INTO
CENTRAL AND EASTERN PORTIONS OF THE FORECAST AREA MONDAY INTO
TUESDAY. INHERITED FCST HAD A MENTION OF LIGHT SNOW FOR THESE
PERIODS AND HAVE KEPT THIS IN PLACE. SNOW MAY LINGER INTO TUESDAY
NIGHT AS A SECONDARY TROUGH OF LOW PRESSURE TRACKS ACROSS THE
CENTRAL CONUS. AFTER TUESDAY NIGHT...DRY CONDS ARE EXPECTED WITH
HIGHS MAINLY IN THE 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1118 PM CST THU DEC 24 2015
THE RAP AND NAM ARE PRETTY CLOSE WITH VFR OVERNIGHT THROUGH AT
LEAST 18Z FRIDAY. THEREAFTER IFR/LIFR IN SNOW AND LOW CIGS SHOULD
INFILTRATE WRN NEB AND SPREAD NORTHEAST TOWARD KVTN BY 00Z FRIDAY
EVENING. AT 00Z...IFR/LIFR IN LIGHT SNOW...FREEZING DRIZZLE
BECOME WIDESPREAD ALONG I-80. SNOW SHOULD BE WIDESPREAD ALONG AND
NORTH OF NEBRASKA HIGHWAY 2 AT THIS SAME TIME.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING FROM 6 PM CST /5 PM MST/ FRIDAY TO 6 PM CST
/5 PM MST/ SATURDAY FOR NEZ004>006-094.
WINTER WEATHER ADVISORY FROM 6 PM CST /5 PM MST/ FRIDAY TO 6 PM
CST /5 PM MST/ SATURDAY FOR NEZ007>010-022>028-035>038-056-057-
059.
&&
$$
SYNOPSIS...BUTTLER
SHORT TERM...JACOBS
LONG TERM...BUTTLER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1248 AM CST FRI DEC 25 2015
.UPDATE...
ISSUED AT 1248 AM CST FRI DEC 25 2015
SUBTLE AREA OF LOW PRESSURE TRACKING EAST ACROSS SOUTHERN NORTH
DAKOTA ALONG A MID LEVEL S/WV TROUGH. SOME LIGHT SNOW WILL BE
POSSIBLE ON THE NORTHERN PERIPHERY OF THE SFC LOW OVER THE NEXT
FEW HOURS. IN THE LOWS WAKE...THE SKY HAS CLEARED ACROSS THE
SOUTHWEST INTO MY SOUTH CENTRAL AND SHOULD CONTINUE TO DO SO EAST
INTO THE JAMES RIVER VALLEY EARLY THIS MORNING. THE CLEAR SKY HAS
ALLOWED FOR PATCHY FOG DEVELOPMENT AND HAVE ADDED THIS INTO THE
FORECAST ALONG TO SOUTH OF THE INTERSTATE 94 CORRIDOR. STRATUS
WILL EVENTUALLY REDEVELOP ACROSS SOUTHERN AREAS OF CWA AS WINDS
TURN NORTHERLY AND ADVECT THE CLOUDS NOW IN PLACE ACROSS THE NORTH
SOUTHWARD 09Z-14Z THIS MORNING. THE INCREASING SKY SHOULD
DISSIPATE ANY FOG THAT FORMS.
UPDATE ISSUED AT 930 PM CST THU DEC 24 2015
MADE SOME SMALL CHANGES AND ADDED FLURRIES TO THE SOUTH CENTRAL
AND NORTH. ALSO THE SOUTHWEST HAS CLEARED AND THIS HAS ALLOWED
TEMPS TO FALL TO NEAR ZERO. LOWERED MINS SOUTHWEST TO AROUND 5
BELOW TONIGHT.
UPDATE ISSUED AT 735 PM CST THU DEC 24 2015
BAND OF SNOW ASSOCIATED WITH THE COLD FRONT REDUCING VISIBILITIES
AS LOW AS 1 3/4 MILES AT MINOT. WILL UPDATE FRO THIS SMALL AREA OF
SNOW ACROSS THE NORTH CENTRAL THIS EVENING. SHOULD TRACK INTO THE
DEVILS LAKE AREA AND DIMINISH TOWARDS MIDNIGHT.
UPDATE ISSUED AT 556 PM CST THU DEC 24 2015
AT 6 PM CST...A WEAK COLD FRONT WAS MOVING SOUTHEAST INTO
NORTHWEST NORTH DAKOTA A BIT FASTER THAN THE LATEST HRRR RUNS
SHOW. THE FRONT IS FORECAST TO REACH THE SOUTH CENTRAL BY
SUNRISE. FOR THE MOST PART SKIES WERE CLOUDY. CLEARING SKIES OVER
SOUTHWEST NORTH DAKOTA ARE FORECAST TO SPREAD EAST OVERNIGHT
LEAVING CLEAR SKIES OVER THE RELATIVELY FRESH SNOW COVER ACROSS THE
SOUTHERN HALF OF NORTH DAKOTA. SHORT RANGE MODELS CONTINUE TO
FAVOR FOG FORMATION OVER THE CLEARING SKIES OVERNIGHT. WILL
MAINTAIN THIS FORECAST TREND.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 254 PM CST THU DEC 24 2015
QUIET CHRISTMAS TRAVEL WEATHER ACROSS WESTERN AND CENTRAL NORTH
DAKOTA HIGHLIGHTS THE SHORT TERM FORECAST.
GIVEN GOOD AGREEMENT...UTILIZED A BLEND OF THE 12 UTC
DETERMINISTIC AND ENSEMBLE SUITES FOR NEARLY ALL FIELDS. THE VERY
PERSISTENT STRATUS DECK OVER THE PAST SEVERAL DAYS WILL CONTINUE
TO REMAIN ACROSS WESTERN AND CENTRAL NORTH DAKOTA TONIGHT INTO
CHRISTMAS DAY WITH NO EXCHANGE IN AIRMASS EXPECTED. THE 15-18 UTC
HRRR ITERATIONS AND 12 UTC NAM NEST WITHIN THEIR VISIBILITY
FORECASTS SUGGEST BUILD DOWN OF STRATUS INTO FOG ACROSS SOUTHWEST
AND SOUTH CENTRAL NORTH DAKOTA TONIGHT. WITH RATHER GOOD
RELIABILITY OF THIS SIGNAL IN THEIR SOLUTIONS OVER THE PAST
WEEK...HAVE ADDED FOG TO MUCH OF THE AREA TONIGHT.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 254 PM CST THU DEC 24 2015
COLD AND QUIET FOR MOST LOCATIONS FRIDAY NIGHT INTO SATURDAY. A
STRONG STORM SYSTEM WILL BRING SIGNIFICANT SNOWFALL AMOUNTS SOUTH
AND EAST OF THE REGION LATER ON FRIDAY THROUGH SATURDAY DAYTIME.
12Z MODELS HAVE COME BACK FARTHER NORTH WITH THE NORTHERN EXTENT
OF A SNOW SHIELD FRIDAY NIGHT AND SATURDAY...BUT STILL KEEPS
ADVISORY CRITERIA SNOWFALL SOUTH AND EAST OF THE SOUTHERN JAMES
RIVER VALLEY. THUS...WE ARE STILL NOT EXPECTING MUCH IMPACT FROM
THIS SYSTEM...BUT WILL HIGHLIGHT IMPACTS ELSEWHERE IN OUR SOCIAL
MEDIA WITH TRAVELERS IN NORTH DAKOTA POTENTIALLY TRAVELING TOWARDS
THE HIGHER SNOWFALL AMOUNTS. STRONG SURFACE HIGH PRESSURE BUILDS
INTO THE NORTHERN PLAINS IN THE WAKE OF THIS STORM
SYSTEM...BRINGING A COLD AIR SURGE WITH IT AND YIELDING
WIDESPREAD BELOW ZERO LOWS FOR SATURDAY NIGHT/SUNDAY MORNING AFTER
HIGHS ONLY IN THE SINGLE DIGITS ABOVE SATURDAY MOST AREAS.
UNCERTAINTY RAMPS UP AFTER THIS WEEKEND WITH A WIDE VARIETY OF
MODEL SOLUTIONS. OVERALL IT APPEARS WE SHOULD MODERATE SOME AS FAR
AS TEMPERATURES...AND MAY SEE ANOTHER CHANCE FOR SNOW MID-WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1248 AM CST FRI DEC 25 2015
A SUBTLE AREA OF SURFACE LOW PRESSURE WILL MOVE EAST ACROSS
CENTRAL AND SOUTHERN NORTH DAKOTA TONIGHT. WIDESPREAD MVFR WILL
PERSIST FROM KISN-KMOT...WHILE KBIS-KDIK-KJMS WILL CLEAR BUT WILL
PERIODICALLY BECOME IFR OR LOWER IN CIGS AND VIS OVERNIGHT WITH
PATCHY FOG. STRATUS NORTH WILL SURGE SOUTH 09Z-14Z WITH A
NORTHERLY WIND AND WILL PERSIST INTO FRIDAY ACROSS THE
SOUTH...LIFTING TO MVFR-VFR NORTH.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...NH
SHORT TERM...AYD
LONG TERM...NH
AVIATION...NH
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1259 AM EST FRI DEC 25 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO
PENNSYLVANIA THROUGH THIS WEEKEND. TEMPERATURES WILL FALL BACK
TOWARD NORMAL NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
930 PM UPDATE...
STILLE NACHT. WIR HABEN NICHT WETTER. ALL IS CALM...ALL IS
BRIGHT - WITH THE FULL MOON GIVING A LUSTER OF MID-DAY TO OBJECTS
BELOW. WILL ADD IN THE MENTION OF A LITTLE VALLEY FOG TO ADD TO
THE SERN COS WHERE A MENTION WAS PREVIOUSLY MADE. THE REST OF THE
AREA HAS VERY DRY AIR AT THE SFC...BUT THE GOOD RADIATIONAL
COOLING IS ALLOWING TEMPS TO CHASE THE DEWPOINTS DOWNWARD.
OTHERWISE...ONLY MID/HIGH CLOUDS EXPECTED. JUST SOME MINOR TWEAKS
MADE TO TIMING/POPS IN SHORT TERM PD.
7 PM UPDATE...
HRR AND RAP STILL HINT AT A SHOWER OVER THE SERN COS IN THE MIDDLE
OF THE NIGHT. BUT ANYTHING SHOULD BE VERY LIGHT. WILL HOLD POPS
BELOW MENTIONABLE. HAVE ADDED SOME FOG TO THE WX GRIDS FOR THE SE
TONIGHT. TEMPS FALLING QUICKLY - BUT SO ARE DEWPOINTS. SO LIMITED
THE MENTION TO THE SE. BUT CAN EASILY SEE THE VALLEYS OF THE N/C
GETTING A LITTLE FOGGY.
PREV...
COLD FRONT AT 20Z OVER SE CORNER OF CWA...WITH JUST A CHANCE FOR A
SHOWER THERE THROUGH LATE EVENING. BULK OF PRECIP HAS SHIFTED WELL
TO THE SE AS LOW LEVEL JET EXITS THE REGION. CLEARING SKIES HAVE
DEVELOPED OVER WESTERN HALF OF PA...WILL SLIDE EASTWARD THIS
EVENING. UNSEASONABLY WARM /RECORD/ TEMPS REMAIN IN PLACE WITH
HIGHS AROUND 70F IN THE SE. NORTHERN AND WESTERN SECTIONS HAVE
LIKELY PEAKED AROUND 60F WITH WEAK CAA WORKING IN.
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD
PROVIDE FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T TOTALLY RULE OUT AN EVENING SHOWER ASSOC WITH
WEAK WAVE OF LOW PRES RIDING ALONG THE FRONTAL BNDRY THAT WILL
STALL JUST AS IT CLEARS CWA. LIKEWISE...A WEAK SHORTWAVE RIDING
ACROSS THE GRT LKS COULD SUPPORT AN ISOLD SHOWER TOWARD DAWN OVR
THE WESTERN MTNS.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM SATURDAY/...
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA LOOKS
TO SPREAD A BIT OF LGT RAIN ACROSS GENERALLY THE SOUTHERN PART OF
THE STATE MAINLY DURING THE LATE MORNING AND AFTERNOON HOURS OF
CHRISTMAS DAY. MODELS IN GOOD AGREEMENT ON TIMING AND AMOUNTS.
GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN VERY WARM FOR
DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE L50S ACROSS THE
NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
A DEEP TROUGH MOVING THROUGH THE CENTRAL UNITED STATES AND LARGE
HIGH PRESSURE AT THE SFC OVER THE EAST COAST WILL DOMINATE THE
WEATHER THROUGH THE WEEKEND. THE STALLED FRONTAL BOUNDARY WILL
CONTINUE TO LIFT NORTH SATURDAY INTO SUNDAY AS A DEEPENING TROUGH
MOVES DOWN THROUGH THE SOUTHWESTERN UNITED STATES. THE INTERACTION
OF THE TROUGH...ALONG WITH THE LARGE HIGH LOCATED OVER THE
ATLANTICWILL COME IN THE FORM OF A QUASI- STATIONARY BOUNDARY
THAT WILL BRING THE NEXT BEST CHANCE FOR PRECIPITATION THIS
WEEKEND.
ALL MID TO LONG RANGE MODELS HAVE THE TROUGH FORM A CUT OFF LOW.
THE BIG QUESTION IS LOCATION HOWEVER THE GEFS/GFS/EC ARE COMING
MORE INTO AGREEMENT ON POSITION AND STRENGTH. ALL OPERATIONAL
RUNS DIG THE LOW THROUGH NORTHERN MEXICO BEFORE TRAVERSING TEXAS
AND LIFTING INTO THE SOUTHERN GREAT LAKES AND THEN MOVING EASTWARD
OVER THE RIDGE. THOUGH THE PREDOMINATE LOCATION IS OVER TEXAS. THE
MODELS ARE COMING INTO A COMMON SOLUTION FOR THE MOVEMENT OF THE
MOIST BOUNDARY THAT SHOULD EXTEND FROM THE TROUGH/LOW THROUGH NEW
ENGLAND. ALL PWATS ARE ANOMALOUS IN THE +3 TO +4 RANGE SO EXPECT
FOR MORE PRECIPITATION SATURDAY THROUGH SUNDAY.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E LAKES
SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY SUNDAY.
COLD AIR DAMMING SCENARIO SATURDAY SHOULD RESULT IN A RELATIVE
COOL DAY /COMPARED TO THOSE RECENTLY/ WITH READINGS STUCK IN THE
40S OVR THE CENTRAL MTNS. WARMER CONDS EXPECTED SUNDAY...AS LOW
LVL COOL AIR IS SCOURED AHEAD OF COLD FRONT. GEFS 925 TEMPS AND EC
MOS SUGGEST TEMPS COULD APPROACH 70F ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS PERSIST FOR A BRIEF
PERIOD OF DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE
INDICATES N STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC
HIGH BUILDING SE FROM ONTARIO. NEXT CHC OF PRECIP COMES MON
NIGHT/TUESDAY...WHEN ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA
THRU THE GRT LKS. HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND
ASSOC SUPPLY OF CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS
FAVOR A WINTRY MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN
TUESDAY. HAVE ADJUSTED THE POPS AND THE PRECIP TYPE ACCORDINGLY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
MAINLY VFR CONDITIONS ACROSS CWA WITH PATCHY VALLEY FOG ESP KIPT
VCTY. SHOWERS WILL SPREAD ACROSS SOUTHERN TAF SITES ON CHRISTMAS
DAY WITH SOME CIG AND VSBY IMPACTS.
OUTLOOK...
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
MON NIGHT-TUE...RESTRICTIONS LIKELY IN A POTENTIAL WINTRY MIX
TURNING TO PLAIN RAIN.
&&
.CLIMATE...
RECORD WARM AIRMASS IN PLACE.
SOME RECORDS SO FAR.
SO FAR TODAY...65 DEGREES AT WILLIAMSPORT. THIS READING WAS
SET AT 256 AM. THIS READING WAS REACHED AGAIN AT 237 PM. THE OLD
RECORD WAS 56 DEGREES SET IN 1931.
FOR WED...HARRISBURG REACHED 66 DEGREES. THIS BROKE THE RECORD
OF 64 DEGREES SET IN 1927.
HARRISBURG...68 DEGREES WAS RECORDED AT 911 AM. THIS BROKE THE
OLD RECORD OF 62 DEGREES SET IN 1990. HARRISBURG WARMED BACK
UP TO 70 DEGREES AT 105 PM.
ALTOONA REACHED 64 DEGREES AT 125 PM TODAY...BREAKING THE RECORD
OF 62 DEGREES SET IN 1955.
BRADFORD REACHED 59 DEGREES AT 140 AM TODAY...BREAKING THE RECORD
OF 55 DEGREES SET IN 1965.
EARLIER INFORMATION BELOW.
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...RXR
NEAR TERM...DANGELO
SHORT TERM...RXR
LONG TERM...FITZGERALD/CERU
AVIATION...ROSS
CLIMATE...
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
311 AM EST FRI DEC 25 2015
.SHORT TERM (TODAY AND TONIGHT)...
FOR MANY LOCATIONS ACROSS THE EASTERN U.S. THIS WILL BE THE WARMEST
CHRISTMAS MORNING ON RECORD. BELOW ARE THE RECORD MAXIMUM LOW
TEMPERATURES FOR DECEMBER 25TH.
CHATTANOOGA60 (1982)
KNOXVILLE55 (1982)
TRI-CITIES54 (1982)
AS OF 3 AM...THE TEMPERATURE AT CHATTANOOGA IS STILL 68 DEGREES. IF
THIS HOLDS IT WILL ANNIHILATE THE OLD DAILY RECORD AND WILL SET AN
ALL TIME RECORD FOR THE MONTH OF DECEMBER. LOOKING BACK THROUGH THE
MONTH OF DECEMBER...66 DEGREES IS THE ALL TIME RECORED MAXIMUM LOW
TEMPERATURE FOR THE MONTH OF DECEMBER FOR CHATTANOOGA SET IN 1951.
RECORDS THERE GO BACK TO 1879 OR 136 YEARS. ALL OF THIS IS THANKS TO
AN ANOMALOUSLY WARM AND MOIST EARLY WINTER PATTERN. CURRENT WATER
VAPOR IMAGERY INDICATES AN UPPER LEVEL RIDGE OFF THE ATLANTIC
SEABOARD WITH A LONGWAVE TROUGH ACROSS THE WESTERN CONUS. WITH THIS
PATTERN...SOUTHWESTERLY WINDS IN THE MID AND UPPER LEVELS CONTINUE
TO KEEP THE ATMOSPHERE SATURATED. AT THE SURFACE...SOUTHERLY WINDS
CONTINUE TO ADVECT IN WARM AIR AND MOISTURE WITH A HIGH ACROSS THE
ATLANTIC AND A LOW ACROSS THE ARKLATEX. A COLD FRONT STRETCHES
NORTHEASTWARD FROM THIS LOW IN THE ARKLATEX TO NEAR MEMPHIS TO NEAR
LOUISVILLE. THIS FRONT WILL PROVIDE A FOCUS FOR SHOWERS AND
CONVECTION TO FORM ALONG LATER IN THE DAY TODAY. LOOKING AT
RADAR...THE BULK OF THE PRECIPITATION IS TO THE SOUTH ACROSS ALABAMA
AND GEORGIA ON WHAT APPEARS TO BE A SECONDARY WARM FRONT AND WEAK
UPPER LEVEL SHORTWAVE TROUGH. DEWPOINTS SOUTH OF THIS BOUNDARY ARE
IN THE UPPER 60S AND LOW 70S.
FOR TODAY...MODELS HAVE THE AREA OF PRECIPITATION CURRENTLY ACROSS
ALABAMA AND GEORGIA MOVING TO THE NORTHEAST THIS MORNING. LOOKING AT
HI-RES MODELS AND LATEST TRENDS...IT APPEARS THE PRECIPITATION EARLY
THIS MORNING SHOULD BE MAINLY ACROSS THE SOUTH AND EAST PORTIONS OF
THE FORECAST AREA AS THE FIRST WEAK SHORTWAVE LIFTS OFF TO THE
NORTHEAST. THE FOCUS LATE THIS MORNING AND THE AFTERNOON SHIFTS BACK
TO THE WEST AS SHOWERS AND STORMS DEVELOP ALONG THE COLD FRONT AND
TRACK TO THE EAST. THE RAP INDICATES ANOTHER WEAK SHORTWAVE TROUGH
THAT WILL INTERACT WITH THIS BOUNDARY. THE MAIN UPPER LEVEL JET MAX
WILL BE WELL TO THE NORTH ACROSS THE GREAT LAKES BUT THE UPPER LEVEL
FLOW ALOFT WILL BE STRONG ENOUGH TO PRODUCE 0-6 KM BULK SHEAR VALUES
OF AROUND 50KTS. SBCAPE VALUES IN THE MOISTURE RICH ENVIRONMENT WILL
BE IN THE 250-750 J/KG RANGE WITH LOW LEVEL 0-1 KM SRH AROUND 150-
250 M2/S2. DUE TO THIS...THERE COULD BE A FEW STRONG TO SEVERE
STORMS LATE THIS MORNING INTO THIS AFTERNOON. IT APPEARS THE BEST
LOCATION WOULD BE ACROSS THE WESTERN COUNTIES CLOSER TO THE FRONT
ALONG THE PLATEAU WITH DAMAGING WINDS BEING THE MAIN THREAT.
WE WILL ALSO CONTINUE TO WATCH THE THREAT FOR FLOODING OVER THE NEXT
24 HRS. MODELS INDICATE THAT MOISTURE CONVERGENCE ALONG THE FRONTAL
BOUNDARY WILL PRODUCE PW VALUES IN THE 1.6-1.8 INCH RANGE THIS
AFTERNOON. THESE VALUES WOULD BE INTO THE 75TH PERCENTILE FOR MID-
SUMMER AND WOULD BE RECORD VALUES FOR DECEMBER.
THEREFORE...EXPECT THE STORMS TODAY WILL BE HIGH PRECIPITATION
PRODUCES WITH QUICK DOWNPOURS PRODUCING AN INCH OR 2 OF RAIN IN A
SHORT PERIOD OF TIME. MANY OF THE AREA RIVERS ARE ALREADY NEARING
FLOOD STAGE DUE TO THE RAINFALL EARLIER THIS WEEK.
.LONG TERM (SATURDAY THROUGH THURSDAY)...
WILL REMAIN IN A SOMEWHAT UNSETTLED WEATHER PATTERN THROUGHOUT THE
EXTENDED. THE MAIN FOCUS OF SHOWER ACTIVITY AND POSSIBLY LIMITED
THUNDERSTORM ACTIVITY EARLY IN THE PERIOD WILL BE THE FRONTAL
BOUNDARY THAT HAS BEEN RESPONSIBLE FOR RECENT RAINFALL AND WILL
CONTINUE TO EFFECT THE REGION. ON SATURDAY...THE BOUNDARY WILL LIFT
NORTH ACROSS THE SOUTHERN APPALACHIAN REGION. THIS WILL KEEP AT
LEAST CHANCE POPS ACROSS THE AREA...WITH CHANCES DECREASING FROM
SOUTH TO NORTH THROUGH THE DAY. THE BOUNDARY WILL CONTINUE TO ACT
AS THE FOCUS OF THE SHOWERS AND BY SATURDAY NIGHT IT WILL HAVE
LIFTED TO OUR NORTH...ALLOWING ONLY LINGERING ISOLATED LIGHT
SHOWERS OVER THE MRX CWA. SUNDAY...THE BOUNDARY WILL AGAIN APPROACH
THE AREA...INCREASE SHOWERS. MONDAY SHOULD BE OUR MOST ACTIVE DAY
AS AN UPPER LOW MOVES IN AND IT ALONG WITH THE OLD FRONTAL BOUNDARY
MOVES ACROSS THE AREA. THIS WILL SPREAD A LARGE BAND OF SHOWERS
ACROSS THE AREA AND PROVIDE OUR BEST CHANCE OF THUNDERSTORMS AND
WILL ALSO INCREASE WINDS ACROSS THE REGION...ESPECIALLY OVER HIGHER
TERRAIN. WILL SEE SOME IMPROVING CONDITIONS BY TUESDAY AS THE
SYSTEM FINALLY EXITS THE REGION. CHANCE TO SLIGHT CHANCE POPS WILL
CONTINUE THROUGH THE REST OF THE PERIOD AS ANOTHER DISTURBANCE
MOVES ACROSS THE REGION WEDNESDAY INTO THURSDAY. AS FOR
TEMPERATURES...THE VERY SEASONALLY WARM CONDITIONS WILL VERY SLOWLY
COOL THROUGH THE PERIOD.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 71 64 75 64 / 100 60 30 20
KNOXVILLE MCGHEE TYSON AIRPORT, TN 71 61 73 60 / 90 60 30 20
OAK RIDGE, TN 70 62 73 60 / 100 80 40 20
TRI CITIES AIRPORT, TN 68 57 70 56 / 90 60 40 20
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...FLOOD WATCH THROUGH SATURDAY MORNING FOR CHEROKEE-CLAY.
TN...FLOOD WATCH THROUGH SATURDAY MORNING FOR ANDERSON-BLEDSOE-BLOUNT
SMOKY MOUNTAINS-BRADLEY-CAMPBELL-CLAIBORNE-COCKE SMOKY
MOUNTAINS-EAST POLK-GRAINGER-HAMBLEN-HAMILTON-HANCOCK-
HAWKINS-JEFFERSON-JOHNSON-KNOX-LOUDON-MARION-MCMINN-MEIGS-
MORGAN-NW BLOUNT-NORTH SEVIER-NORTHWEST CARTER-NORTHWEST
COCKE-NORTHWEST GREENE-NORTHWEST MONROE-RHEA-ROANE-SCOTT TN-
SEQUATCHIE-SEVIER SMOKY MOUNTAINS-SOUTHEAST CARTER-
SOUTHEAST GREENE-SOUTHEAST MONROE-SULLIVAN-UNICOI-UNION-
WASHINGTON TN-WEST POLK.
VA...FLOOD WATCH THROUGH SATURDAY MORNING FOR LEE-RUSSELL-SCOTT-
WASHINGTON-WISE.
&&
$$
MA/MJB
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1030 PM CST THU DEC 24 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 327 PM CST THU DEC 24 2015
LINGERING GUSTY WINDS WILL END DURING THE REST OF THE AFTERNOON
AS THE DEEP STORM SYSTEM WHICH PRODUCED STRONG WINDS OVERNIGHT
MOVES FURTHER NORTHEAST.
WITH THE EXCEPTION OF SOME HOLES IN THE CLOUD COVER FOR AREAS EAST
OF THE FOX RIVER EARLY THIS AFTERNOON...CLOUDS WERE PERSISTENT
ACROSS THE AREA. WHERE LOW LEVEL CLOUDS HAVE SCOURED OVER EAST
CENTRAL WISCONSIN...LOWERING MID LEVEL CLOUDS WILL BE ON THE
INCREASE THIS AFTERNOON AND EVENING AS A WEAK SHORT WAVE TRACKS
FROM IOWA TO SOUTHERN WISCONSIN. THE MODELS ARE IN SOME AGREEMENT
WITH THE NORTHERN FRINGE OF THE LIGHT SNOW BRUSHING OVER PARTS OF
CENTRAL AND EAST CENTRAL WISCONSIN THIS EVENING BEFORE DEPARTING
JUST AFTER MIDNIGHT. HRRR DIMINISHES THIS AREA OF LIGHT SNOW WHILE
WORKING NORTHWARD SO WILL MAINLY GO WITH HIGHER END CHC POPS SOUTH
OF HIGHWAY 10.
SURFACE HIGH PRESSURE REGION AND UPPER REGION BUILDS INTO THE AREA
FRIDAY FOR A QUIET XMAS DAY.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 327 PM CST THU DEC 24 2015
THE MAIN CONCERNS DURING THIS PART OF THE FORECAST ARE A COUPLE OF
SYSTEMS WITH THE POTENTIAL TO PRODUCE SEVERAL INCHES OF SNOWFALL
IN THE FORECAST AREA. THE FIRST ARRIVES LATE FRIDAY NIGHT AND THE
NEXT LOOKS TO BE EARLY IN THE UPCOMING WORK WEEK.
MODELS ONCE AGAIN SHOWED A STRONG UPPER JET STREAK NORTH OF
WISCONSIN. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE JET WILL
ASSIST AN APPROACHING MID LEVEL SHORT WAVE TROUGH IN DEVELOPING
SNOW ACROSS NORTHERN WISCONSIN FRIDAY NIGHT AND SATURDAY. HIGHEST
QPF VALUES WERE FORECAST IN THE NORTH AND THERE MAY BE SEVERAL
INCHES OF SNOW BEFORE THINGS WIND DOWN SATURDAY EVENING. MOST OF
THE 12Z MODELS SHOWED ONE LARGE AREA OF QPF DEVELOPING...THE NAM
KEPT TWO SEPARATE AREAS...AS A SURFACE LOW MOVING ALONG A COLD
FRONT ENTERS THE REGION. PRECIPITATION AMOUNTS SHOULD BE LIGHTER
BETWEEN THE TWO MAXIMA AND SOME WILL FALL AS RAIN IN PARTS OF
EASTERN WISCONSIN. SO...SNOWFALL NUMBERS ARE RATHER QUESTIONABLE
IN CENTRAL AND EASTERN WISCONSIN. SURFACE HIGH PRESSURE BUILDING
INTO THE AREA WILL KEEP A CHANCE FOR LAKE EFFECT SNOW SHOWERS IN
FAR NORTH CENTRAL WISCONSIN THROUGH AT LEAST SUNDAY.
SURFACE AND 500MB LOWS MOVING FROM THE PLAINS TO THE GREAT LAKES
REGION COULD BRING SIGNIFICANT SNOWFALL TO THE AREA...BUT THERE IS
TOO MUCH DISAGREEMENT AMONG THE MODELS TO GO WITH ANYTHING HIGHER
THAN A CHANCE FOR SNOW ON MONDAY NIGHT AND TUESDAY. THE 12Z
CANADIAN-NH BRINGS LITTLE OR NO PRECIPITATION TO THE AREA AT
ALL...WHILE THE ECMWF HAD MORE THAN 0.50 INCH OF QPF IN THE
SOUTHERN PART OF THE AREA. THE GFS LOOKED MORE SIMILAR TO THE
CANADIAN THAN TO THE EC. WILL HAVE TO KEEP A CLOSE WATCH ON THE
SYSTEM.
TEMPERATURES WILL BE ABOVE NORMAL FOR THIS TIME OF YEAR...BUT NOT
NEARLY AS WARM AS THEY HAVE BEEN IN THE RECENTLY.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1014 PM CST THU DEC 24 2015
LIGHT SNOW/FLURRIES WERE FALLING OVER CENTRAL WI AND PARTS OF THE
FOX VALLEY LATE THIS EVG. THE SNOW IS EXPECTED TO GRADUALLY TAPER
OFF FROM WEST TO EAST OVERNIGHT...AND SHOULD BE GONE BY 09Z-10Z/FRI.
CIGS VARIED CONSIDERABLY OVER THE REGION...RANGING FROM IFR OVER
NC WI...TO MVFR/VFR ELSEWHERE.
MAIN FCST CONCERN IS CLOUD TRENDS LATER TONIGHT INTO CHRISTMAS
MORNING. CURRENT THINKING IS THAT PARTIAL CLEARING WILL OCCUR
OVER NE WI LATE TONIGHT AS MID-LEVEL MOISTURE DECREASES. LOW
CLOUDS WILL LIKELY PERSIST IN NC WI WELL INTO CHRISTMAS MORNING...
AND PERHAPS PAST MIDDAY IN THE FAR NORTH. WILL WORK THESE TRENDS
INTO THE 06Z TAFS.
HIGH/MID CLOUDS WILL INCREASE DURING THE LATE AFTERNOON AND
EVENING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TDH
LONG TERM......MG
AVIATION.......KIECKBUSCH
AREA FORECAST DISCUSSION
NWS RENO NV
312 AM PST FRI DEC 25 2015
.SYNOPSIS...
ISOLATED TO SCATTERED LIGHT SNOW SHOWERS REMAIN POSSIBLE TODAY.
FRESH SNOW COVER WILL LEAD TO WIDESPREAD COLD TEMPERATURES
CHRISTMAS DAY THROUGH THE WEEKEND. A WEAKENING STORM WILL BRING
LIGHT SNOW SHOWERS TO THE REGION MONDAY, WITH THE POTENTIAL FOR AN
INSIDE SLIDER WEDNESDAY PROVIDING A CHANCE FOR SNOW FOR NORTHERN
AND WESTERN NEVADA.
&&
.SHORT TERM...
A WEAK UPPER DISTURBANCE WILL MOVE FROM NEAR ALTURAS INTO NORTHERN
AND CENTRAL NEVADA TODAY. THE DISTURBANCE WILL BE WORKING WITH A
MOIST ATMOSPHERE AND MODERATE LAPSE RATES ALOFT UNDER A COLD
TROUGH SO IT SHOULDN`T BE TOO HARD FOR ISOLATED TO SCATTERED SNOW
SHOWERS TO DEVELOP FROM NORTH TO SOUTH ACROSS THE REGION TODAY.
THE GFS, NAM, EC AND HRRR ALL SHOW THIS TO SOME DEGREE. SHOWERS
LOOK QUITE LIGHT WITH MINIMAL ACCUMULATIONS (AT BEST), ALTHOUGH
ANY LIGHT COATING COULD MAKE CLEARED ROADS SLICK AGAIN.
TONIGHT AND SATURDAY, AN UPPER RIDGE WILL BEGIN TO NUDGE IN FROM
THE EASTERN PACIFIC, WITH A 1040-ISH MB SURFACE HIGH BUILDING INTO
NORTHERN NEVADA. THIS WILL SET UP A STRONG NORTHEAST-EAST GRADIENT
ACROSS THE SIERRA CREST WITH SOME EASTERLY WINDS DEVELOPING ON
LAKE TAHOE LATE TONIGHT. HOWEVER, WITH INVERSIONS SMASHING DOWN
OVERNIGHT, VERY STRONG WINDS ALOFT MAY HAVE DIFFICULTY WORKING
DOWN TO THE LAKE SURFACE WITH STRONGER WINDS MAINLY AT THE
IMMEDIATE SIERRA CREST AND PERHAPS LOCALLY PUSHING THROUGH THE
CARSON RANGE (TO THE WEST OF SPOONER SUMMIT). STILL, I HAVE KEPT
THE LAKE WIND ADVISORY FOR TAHOE GOING AS WINDS SHOULD STILL BE
ELEVATED AND CAUSE A NOTABLE INCREASE IN WAVES FOR THE WEST SHORE.
TEMPERATURE-WISE TONIGHT AND SATURDAY NIGHT, THE BUILDING RIDGE
WILL BRING SLACKENING WIND, CLEARING SKIES AND A VERY CHILLY NIGHT
(CONSIDERABLY COLDER THAN THIS MORNING) ESPECIALLY IN AREAS OF
SNOW COVER. VALLEY LOWS SHOULD FALL INTO THE SINGLE DIGIT TO
10 DEGREE RANGE FOR THE "WARMER" BASIN SPOTS SUCH AS THE RENO
AIRPORT AND NON-SNOW COVERED VALLEYS, WITH BELOW ZERO FOR COLDER,
SNOW-COVERED VALLEYS AND FOR THE SIERRA VALLEYS. WITH THE BUILDING
UPPER RIDGE, HIGHER ELEVATIONS/RIDGES ARE EXPECTED TO WARM SOME
8-15 DEGREES BETWEEN FRIDAY AND SATURDAY NIGHTS. THIS WILL ALSO
SET UP STRONG VALLEY INVERSIONS AND VERY LIMITED MIXING FOR
SATURDAY.
SUNDAY, WINDS COME AROUND TO WEST FROM 700 MB (~RIDGETOP) UP AS
MODEST LOW PRESSURE APPROACHES THE PACIFIC COAST. HOWEVER, WINDS
DO NOT LOOK STRONG ENOUGH TO MIX OUT VALLEY INVERSIONS SO STAGNANT
CONDITIONS WITH CHILLY TEMPERATURES SHOULD CONTINUE. SNYDER
.LONG TERM...MONDAY THROUGH THURSDAY...
A FEW MINOR CHANGES WERE MADE TO THE EXTENDED FORECAST...PRIMARILY
TO MONDAY. THE MEDIUM RANGE FORECAST MODELS ARE IN SLIGHTLY BETTER
AGREEMENT THAT A FAST MOVING SLIDER-TYPE AREA OF LOW PRESSURE WILL
DROP DOWN THE SIERRA MONDAY MORNING. THE ECMWF IS A LITTLE WETTER
WITH THIS SYSTEM THAN THE GFS...BUT BOTH ARE TRYING TO DEVELOP
PRECIPITATION ACROSS THE REGION. THE PRIMARY CHANGE WAS TO SPREAD
LOW CHANCE POPS INTO WESTERN NEVADA AS OPPOSED TO HAVING THEM
CONFINED MAINLY TO THE SIERRA. THIS MAY NOT BE A BIG PRECIPITATION
MAKER BUT COULD DEVELOP EARLY MONDAY MORNING.
THE MODELS ALSO SHOW ANOTHER FAST MOVING WAVE DROPPING THROUGH THE
INTERMOUNTAIN WEST WEDNESDAY. THERE IS MUCH MORE DISAGREEMENT WITH
THIS SYSTEM AS THE GFS IS FAIRLY WEAK AND HAS VERY LIMITED
PRECIPITATION. MEANWHILE...THE ECMWF IS FAR MORE AGGRESSIVE WITH
PRECIPITATION ASSOCIATED WITH THIS SYSTEM FOR WEDNESDAY. FOR NOW WE
WILL GO WITH SLIGHT CHANCE POPS FOR MOST AREAS. THE MODELS REALLY
BEGIN TO DIVERGE AFTER WEDNESDAY AS THE GFS STARTS TO BUILD A RIDGE
WHILE THE ECMWF STALLS A LOW OVER THE REGION.
MODEL GUIDANCE HIGH TEMPERATURES FOR THE EXTENDED PERIOD LOOK TO BE
OVER DONE GIVEN THE PREVALENCE OF NORTH TO NORTHWEST FLOW IN THE LOW
TO MID LEVELS SO FORECAST HIGHS WERE LEFT A LITTLE BELOW GUIDANCE. 20
&&
.AVIATION...
FORECAST MODELS ARE TRYING TO DROP ANOTHER WEAK WAVE THROUGH THE
FORECAST AREA TODAY. THAT WOULD MEAN SCATTERED SNOW SHOWERS AT TIMES
WITH REDUCED CIGS/VSBYS...ESPECIALLY FOR THE SIERRA TERMINALS. MVFR
OR WORSE CIGS/VSBYS ARE POSSIBLE FOR KTRK AND KTVL LATER THIS
MORNING AND THIS AFTERNOON ALONG WITH OBSCURED MOUNTAINS. KTRK AND
KTVL COULD SEE UP TO AN INCH OF ACCUMULATION TODAY.
FOR TERMINALS EAST OF THE SIERRA CIGS/VSBYS SHOULD REMAIN VFR...BUT
THERE COULD BE SNOW SHOWERS AFFECTING THE APPROACHES TO THE TERMINALS...
IF NOT AT THE TERMINALS THEMSELVES.
SURFACE WINDS SHOULD NOT GUST TO MORE THAN 15-20 KTS TODAY BUT WINDS
ALOFT ARE LIKELY TO STRENGTHEN LATE THIS AFTERNOON AND THIS EVENING
FROM THE NORTHEAST. THIS WILL INCREASE THE POSSIBILITY OF TURBULENCE
WEST OF THE MOUNTAIN RANGES LATER TODAY AND TONIGHT. RIDGE BUILDS
FOR SATURDAY THEN SLIDES EAST SUNDAY. THIS SHOULD PRODUCE LESS WIND
ALOFT EACH DAY. 20
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...LAKE WIND ADVISORY FROM 10 PM THIS EVENING TO 10 AM PST SATURDAY
FOR LAKE TAHOE IN NVZ002.
CA...LAKE WIND ADVISORY FROM 10 PM THIS EVENING TO 10 AM PST SATURDAY
FOR LAKE TAHOE IN CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS TAUNTON MA
951 AM EST FRI DEC 25 2015
.SYNOPSIS...
QUIET AND MILD WEATHER THROUGH TONIGHT WITH LIGHT RAIN POSSIBLE
ALONG THE SOUTH COAST. HIGH PRESSURE MOVES OFFSHORE SATURDAY
MORNING. LOW PRESSURE RACES OUT OF THE MIDWEST...PASSING ACROSS
NORTHERN NEW ENGLAND SUNDAY...WHILE SWINGING A COLD FRONT ACROSS
SOUTHERN NEW ENGLAND. HIGH PRESSURE BRINGS COOLER AIR MONDAY. A
STORM LIFTING OUT OF TEXAS WILL SPREAD GULF MOISTURE OVER NEW
ENGLAND TUESDAY...AND BRING A ROUND OF WINTRY PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE ...
FOG HAS FOR THE MOST PART ERODED PER A CHECK ON LOCAL AREA WEBCAMS.
ONLY MIST LINGERS IN THE RIVER VALLEYS AND NEAR BODIES OF WATER ...
BUT SHOULD DISSIPATE IN THE NEXT HOUR AS THE WINTER-SUN CONTINUES
TO RISE. LIGHT WINDS BENEATH HIGH PRESSURE WITH SCATTERED TO BROKEN
MID-LEVEL CLOUD DECKS ... WE SHOULD WARM UP APPRECIABLY INTO THE
LOW-60S ... POTENTIALLY CLOSE IF NOT BREAKING HIGH TEMPERATURE RECORDS
ACROSS THE AREA.
CLOUDS WILL BE ON THE INCREASE LATE AHEAD OF SOME WEAK S-STREAM
ENERGY MEETING UP WITH A COLD FRONT ALONG THE LEADING EDGE OF
COOLER HIGH PRESSURE OUT OF CANADA. COULD SEE SOME SHOWERY WEATHER
ENTER THE N/W-PORTIONS OF S NEW ENGLAND. TAILORED SLIGHT CHANCE
POPS AS FRONTOGENESIS MEETS UP WITH LOW-LEVEL WARM-MOIST ISENTROPIC
ASCENT. HRRR HAS A TREND FOR A LINE OF LIGHT WET- WEATHER.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
TONIGHT ...
ADJUSTED FORECAST TO SUGGEST A SLIGHT CHANCE OF SHOWERS ACROSS THE
INTERIOR WITH A BETTER CHANCE ALONG THE S-COAST. THIS AS A COLD
FRONT SWEEP S AHEAD OF COOL HIGH PRESSURE OUT OF CANADA ... MEETING
UP WITH S-STREAM ENERGY AND WEAK WARM-MOIST ISENTROPIC ASCENT
WITHIN THE LOW-LEVELS. NOTHING SUBSTANTIAL. CLOUDS BLANKETING THE
AREA AS WINDS REVERT OUT OF THE N BEHIND THE COLD FRONT USHERING
DRY AIR S ALONG WITH COOLER AIR. COLD AIR ADVECTION PROCEEDING INTO
MORNING ... SHOULD SEE LOWS BOTTOM OUT AROUND THE UPPER-30S.
SATURDAY ...
HIGH PRESSURE MOVES OFFSHORE RESULTING IN A MOSTLY DRY MORNING. RAIN
CHANCES INCREASE THROUGH THE AFTERNOON AS LOW PRESSURE APPROACHES
FROM THE GREAT LAKES. BETWEEN THE COOLER AIR IN THE REGION AND
ONSHORE FLOW...EXPECT HIGHS STILL ABOVE NORMAL BUT BACK DOWN IN
THE MID 40S TO AROUND 50.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
BIG PICTURE...
NOT MANY CHANGES IN 25/00Z GUIDANCE. LONGWAVE PATTERN STILL FAVORS
A MID LEVEL RIDGE OVER THE EAST...WITH A DEEP TROUGH OVER THE
WESTERN USA. FOR THE MOST PART...THIS TREND WILL CONTINUE.
ALTHOUGH THERE WILL BE SOME VARIATIONS AS VARIOUS SHORTWAVES MOVE
THROUGH THE LARGER PATTERN. THIS SHOULD MEAN OUR RATHER ACTIVE
WEATHER PATTERN CONTINUES INTO NEXT WEEK.
WE STILL EXPECT ABOVE NORMAL TEMPERATURES OVER THIS WEEKEND...THEN
TURNING COLDER SUNDAY NIGHT/MONDAY. LOW LEVEL EAST FLOW AND
PRECIPITATION AROUND TUESDAY MAY MAINTAIN THE COLDER AIR...BUT
THE TREND SHOULD THEN BE FOR LESS COLD FOR THE LATTER HALF OF NEXT
WEEK.
MODELS ARE SIMILAR ON THE OVERALL PATTERN...WITH SOME DIFFERENCES
IN THE DETAILS. WITH TEMPERATURES NEAR FREEZING THOUGH...THESE
DIFFERENCES COULD HAVE A BIG IMPACT ON THE ULTIMATE FORECAST
OUTCOME.
THE DAILIES...
SATURDAY NIGHT-SUNDAY...STRONG JET DYNAMICS CONTINUE NEAR OUR
REGION. ABOVE NORMAL TEMPERATURES CONTINUE AS A LOW PRESSURE
PASSE US BY TO OUR WEST. THIS SHOULD MEAN ALL RAIN FOR
PRECIPITATION TYPE.
WITH A WARM FRONT TO OUR NORTH EARLY SUNDAY MORNING...WE MAY
ACTUALLY HAVE A SHORT BREAK IN RAINFALL. BUT CHANCE POPS CONTINUE
INTO THE AFTERNOON AS A MID LEVEL SHORTWAVE AND COLD FRONT MOVES
THROUGH THE REGION.
MONDAY...HIGH PRESSURE OVER CANADA BRINGS COLD ADVECTION. THE
INITIAL SURGE OF COLDER AIR SHOULD RESULT IN BETTER MIXING...AND
GUSTY WINDS.
MONDAY NIGHT-TUESDAY...SURFACE HIGH PRESSURE REMAINS IN PLACE
OVER THE MARITIMES. THIS SHOULD HOLD THE COLD AIR IN PLACE AS A
STORM TRACK FROM TEXAS INTO THE GREAT LAKES. LATEST TRENDS IN THE
GUIDANCE IS TOWARD A COLDER SOLUTION. STILL NOT A CERTAINTY
THOUGH. 25/00Z GEFS SHOWS A REASONABLE SPREAD AMONG THE INDIVIDUAL
MEMBERS. THIS SPREAD EXPANDS QUITE A BIT TUESDAY AFTERNOON INTO
TUESDAY NIGHT.
AS THIS IS JUST A DAY 5 FORECAST...THERE REMAINS PLENTY OF
UNCERTAINTY IN THE PRECIPITATION TYPE DETAILS. LATEST FORECAST
SOUNDINGS SHOW AT LEAST A FEW HOURS OF SNOW ACROSS MOST OF
SOUTHERN NEW ENGLAND. THE BIG QUESTION WILL BE HOW LONG THE COLD
AIR CAN BE HELD IN PLACE. STILL THE POSSIBILITY OF SOME RAIN...
SLEET...RAIN...OR EVEN SOME FREEZING RAIN IN SPOTS. THIS WILL NEED
TO BE MONITORED OVER THIS WEEKEND AS MORE INFORMATION COMES IN.
WEDNESDAY-THURSDAY...ANOTHER SHORTWAVE MOVES THROUGH OUR REGION
AND DRIVES A COLD FRONT THROUGH NEW ENGLAND WEDNESDAY NIGHT OR
THURSDAY. WE WILL MENTION CHANCE POPS WITH THIS FRONTAL PASSAGE.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY/ ...
TODAY ... HIGH CONFIDENCE.
VFR. LOW-END VFR CIGS DOWN TO MVFR POSSIBLY RETURNING TOWARDS
EVENING AHEAD OF AN APPROACHING SWEEPING COLD FRONT. MAY ALSO HAVE
TO CONTEND WITH SOME VSBY ISSUES ALONG THE S-COAST AS WELL.
TONIGHT ... HIGH CONFIDENCE.
LOW RISK MVFR CONTINUES ALONG THE S-COAST TILL THE COLD FRONT
SWEEPS THE TERMINALS. -SHRA POSSIBLE ALONG AND AHEAD. BEHIND THE
FRONT WINDS BACK N.
SATURDAY ... MODERATE CONFIDENCE.
VFR TO START...THEN DETERIORATING CONDITIONS EXPECTED DURING THE
AFTERNOON AS RAIN MOVES INTO THE REGION.
KBOS TERMINAL...
COULD BE A SLIGHT CHANCE OF -SHRA DURING THE EVENING. OTHERWISE
LOW- END VFR AT WORST.
KBDL TERMINAL...
VFR. SLIGHT CHANCE OF -SHRA INTO EVENING PRIOR TO A COLD FRONT
SWEEPING THE TERMINAL AROUND 3Z.
OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/...
SATURDAY NIGHT-SUNDAY ... MODERATE CONFIDENCE.
CIGS/VSBYS LOWERING TO AT LEAST MVFR SATURDAY NIGHT WITH AREAS OF
IFR IN RAIN AND FOG. A WARM FRONT LIFTS NORTH OF THE REGION SUNDAY
WHICH SHOULD BRING IMPROVING CONDITIONS. STILL EXPECT MVFR CIGS
AND SCATTERED MVFR/IFR VSBYS IN SHOWERS. LOW LEVEL WIND SHEAR A
CONCERN... ESPECIALLY SOUTH OF BOSTON AS A 45-50 KNOT LOW LEVEL
JET MOVES OVERHEAD.
MONDAY ... MODERATE CONFIDENCE.
VFR AS HIGH PRESSURE MOVES OVER NEW ENGLAND. NORTH TO NORTHWEST
WINDS WILL INCREASE WITH GUSTS TO 25 KT POSSIBLE ALONG THE COASTAL
PLAIN AND ISLANDS.
TUESDAY ... LOW CONFIDENCE.
CONDITIONS LOWERING TO IFR IN DEVELOPING SNOW. SNOW POSSIBLY
CHANGING TO SLEET/FREEZING RAIN INLAND...WITH RAIN TOWARD THE
COAST DURING THE AFTERNOON. CIGS/VSBYS MAY IMPROVE TO MVFR IN THE
RAIN.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH SATURDAY/ ... HIGH CONFIDENCE.
SMALL CRAFT ADVISORIES REMAIN IN PLACE FOR THE SOUTHERN OUTER
WATERS FOR SEAS GREATER THAN 5 FEET. SEAS DIMINISH THROUGH THE
PERIOD AS HIGH PRESSURE BUILDS OVER THE WATERS. WINDS REMAIN LESS
THAN 15 KTS THROUGH TONIGHT THEN INCREASE TO AROUND 20 KTS
SATURDAY. VISIBILITIES WILL LIKELY BE LIMITED FOR A PORTION OF THE
DAY TODAY IN DENSE FOG.
OUTLOOK /SATURDAY NIGHT THROUGH TUESDAY/ ...
SATURDAY NIGHT-SUNDAY ... MODERATE CONFIDENCE.
WARM FRONT MOVES NORTH ACROSS THE WATERS LATE SATURDAY NIGHT OR
SUNDAY MORNING...BRINGING POOR VSBYS IN RAIN AND FOG. BEHIND THIS
WARM FRONT...WINDS AND SEAS INCREASE OUT OF THE SOUTH AND
SOUTHWEST. SOUTHWEST WINDS WILL GUST TO 25-30 KNOTS. SEAS WILL
BUILD TO 5-8 FEET...MAINLY ON THE OUTER WATERS AND EXPOSED
SOUTHERN WATERS. SMALL CRAFT ADVISORIES ARE EXPECTED TO BE NEEDED.
MONDAY ... MODERATE CONFIDENCE.
A LULL IN THE PRECIPITATION. NORTHWEST WINDS WILL GUST 25-30
KNOTS. THIS WILL KEEP ROUGH SEAS OF 5-8 FEET ACROSS THE OUTER
COASTAL WATER. SMALL CRAFT ADVISORIES LIKELY TO CONTINUE.
TUESDAY ... LOW CONFIDENCE.
ANOTHER WEATHER SYSTEM MOVES PAST NEW ENGLAND...WITH SNOW
CHANGING TO RAIN OVER THE WATERS. INCREASING EAST TO NORTHEAST
WINDS WITH SPEEDS REACHING 25 TO 30 KNOTS. SEAS AGAIN BUILD 5-9
FEET...HIGHEST ON THE OUTER WATERS. SMALL CRAFT ADVISORY LIKELY TO
BE NEEDED.
&&
.CLIMATE...
RECORD HIGH MINIMUM TEMPERATURES FOR FRIDAY 12/25...
BOSTON 44/2014
PROVIDENCE 46/1979
HARTFORD 43/2014
WORCESTER 47/1964
RECORD HIGH TEMPERATURES FOR FRIDAY 12/25...
BOSTON 65/1889
PROVIDENCE63/2014
HARTFORD64/1964
WORCESTER60/1964
RECORD HIGH TEMPERATURES FOR SUNDAY 12/27...
BOSTON 61/1949
PROVIDENCE59/1973
HARTFORD60/1949
WORCESTER 58/1895
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 AM EST SATURDAY FOR ANZ254>256.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR ANZ235-
237.
&&
$$
SYNOPSIS...BELK/RLG
NEAR TERM...BELK/RLG/SIPPRELL
SHORT TERM...RLG
LONG TERM...BELK
AVIATION...BELK/RLG/SIPPRELL
MARINE...BELK/RLG
CLIMATE...WFO BOX STAFF
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
951 AM CST FRI DEC 25 2015
.UPDATE...
ISSUED AT 950 AM CST FRI DEC 25 2015
Large area of stratus extending from Wisconsin to the north half
of Missouri this morning. The eastern fringe has scraped the
western edge of our forecast area, with rather persistent coverage
from Galesburg to Winchester, but a little bit of erosion was
taking place at mid morning. The HRRR has handled this well and
shows a bit more erosion of it in our area, but high clouds
streaming over the top will keep skies there mostly cloudy today.
The southeast CWA has seen mainly cirrus moving through. In
between, there is a decent amount of sunshine, but the cirrus will
be filling in with time during the afternoon.
Have sent some updates to remove the slight chance PoP`s in the
far southeast for this morning, and also adjusted the timing of
the PoP`s for tonight, concentrating them mostly after midnight.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CST FRI DEC 25 2015
09z/3am surface analysis shows weak frontal boundary extending from
southern Ohio to Arkansas, with a 1023mb high noted further upstream
across Iowa. A few sprinkles have been occurring from time to time
across the E/SE KILX CWA in association with the Ohio River Valley
front and this trend will continue for the next few hours as per the
HRRR forecast. As a result, will carry slight chance for light
showers south of I-70. Meanwhile, an area of low clouds/fog trapped
beneath the subsidence inversion beneath the Iowa high has been
slowly spreading eastward over the past few hours. Latest satellite
shows the leading edge of the clouds along a Galesburg to Macomb
line. Based on satellite trends and HRRR cloud height forecast,
will feature overcast conditions along/west of the Illinois River
this morning. The low clouds will gradually dissipate toward
midday, followed by partly sunny conditions across the board through
afternoon. High temperatures will mainly be in the middle to upper
40s, with lower 50s across the E/SE.
.LONG TERM...(Tonight through Thursday)
ISSUED AT 329 AM CST FRI DEC 25 2015
Major rain event is still unfolding across parts of central and
southeast Illinois this weekend as deep-layer southwesterly flow
establishes itself across the region. As upper low cuts off over
the Desert Southwest and a corresponding ridge develops downstream
across the eastern CONUS, the Ohio River Valley frontal boundary
will lift northward into central Illinois late tonight into
Saturday. The front will then become parallel to the upper flow and
stall across the area. With baroclinic zone in place, plenty of
Gulf of Mexico moisture flowing northward, and weak upper waves
tracking through the southwest flow to provide enhanced lift...a
prolonged period of moderate to heavy rain will develop this
weekend. Models have continued to slow the process however, with
tonight now remaining mostly dry. Have lowered PoPs to just
slight chance across all but the far S/SE accordingly. As front
stalls, rain will begin in earnest on Saturday, then continue
through Saturday night. Thanks to increasing instability, may
even see a few thunderstorms as well. As seen for the past
several model runs, a northern stream short-wave tracking from the
Northern Plains into the Great Lakes will push the front further
south on Sunday. 00z Dec 25 models are in good agreement that
the boundary will drop well south of the Ohio River, resulting in
decreasing rain chances Sunday/Sunday night. In fact, have
dropped PoPs altogether along/north of a Rushville to Bloomington
line during the afternoon and as far south as the I-72 corridor by
evening. Further south, rain will continue to fall across the
remainder of the area through Sunday night.
A vigorous wave coming off the Pacific will eventually eject the
Desert Southwest closed upper low northeastward early next week,
with the latest models now in much better agreement concerning the
timing of this process. The exact track of the low still remains in
question however, which poses some big challenges to the PoP/precip
type forecast late Sunday night through Monday night. ECMWF remains
the further west with the track...taking the corresponding surface
low from near St. Louis midday Monday to Chicago by midnight.
Meanwhile both the GFS and GEM are further east...with the low
tracking from western Kentucky to northwest Ohio during that time
frame. Will follow the more consistent ECMWF here, which keeps the
KILX CWA warmer and results in mostly liquid precip. May see a
period of light freezing rain on the northern periphery of the
precip as it returns northward late Sunday night into Monday:
however, with warm nose aloft at 5-6C and surface temps only
slightly below freezing across the north, think any ice accumulation
will be minimal. Based on expected surface temps, will mention
freezing rain along/north of a Rushville...to Lincoln...to Danville
line. Temps will edge above freezing everywhere toward midday
Monday, resulting in a change over to all rain. As the low
approaches, may even see a few thunderstorms south of the I-72
corridor. Once the low tracks into the southern Great Lakes, enough
cold air will be pulled down behind it to support a change over to
snow or a rain/snow mix along/north of a Taylorville to Danville
line Monday night. Will need to keep an eye on this, as any
eastward deviation of the low track will lead to more snow and
possible accumulations across the area.
Precip will come to an end on Tuesday, with storm total rainfall
from tonight through Monday night ranging from around 1 inch
northwest of the Illinois River...to as much as 5-6 inches
along/south of I-70. With so much rain expected to fall on already
wet soil and the potential for thunderstorms to produce excessive
rainfall rates, will be issuing a Flash Flood Watch for areas
along/southeast of a Danville to Taylorville line starting midday
Saturday and ending Monday evening. Main concerns will be rapid
rises on area creeks/streams and urban flooding in poor drainage
areas.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 600 AM CST FRI DEC 25 2015
Satellite images show MVFR/IFR ceilings approaching PIA and SPI
on increasing NW winds. The eastward progress of the clouds has
been slowed by the wind becoming more northerly with time, so the
arrival of MVFR/IFR conditions has been delayed until 13z. HRRR
model output indicates the low clouds will only be near PIA and
SPI for a couple hours, then retreat back to the west as they
dissipate in turbulent mixing.
High pressure building into Illinois from the northwest should
provide clearing skies this afternoon, with winds shifting around
to the east-northeast by late afternoon. Wind speeds should remain
less than 10kt until they become northeast, then they will
increase to 10-13kt as the pressure gradient tightens.
A frontal boundary stalled to the southeast of IL will gradually
lift northward later tonight, in response to a sharpening of the
upper trough across the Rockies. MVFR clouds and light fog will
expand northward later tonight as a result. Rain chances will
increase as well, but we held off on any mention of rain before
12z Sat morning. Better rain chances should come just after 12z.
&&
.ILX Watches/Warnings/Advisories...
Flash Flood Watch from Saturday afternoon through Monday
afternoon for ILZ052-054>057-061>063-066>068-071>073.
&&
$$
UPDATE...Geelhart
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
600 AM CST FRI DEC 25 2015
.SHORT TERM...(Today)
ISSUED AT 329 AM CST FRI DEC 25 2015
09z/3am surface analysis shows weak frontal boundary extending from
southern Ohio to Arkansas, with a 1023mb high noted further upstream
across Iowa. A few sprinkles have been occurring from time to time
across the E/SE KILX CWA in association with the Ohio River Valley
front and this trend will continue for the next few hours as per the
HRRR forecast. As a result, will carry slight chance for light
showers south of I-70. Meanwhile, an area of low clouds/fog trapped
beneath the subsidence inversion beneath the Iowa high has been
slowly spreading eastward over the past few hours. Latest satellite
shows the leading edge of the clouds along a Galesburg to Macomb
line. Based on satellite trends and HRRR cloud height forecast,
will feature overcast conditions along/west of the Illinois River
this morning. The low clouds will gradually dissipate toward
midday, followed by partly sunny conditions across the board through
afternoon. High temperatures will mainly be in the middle to upper
40s, with lower 50s across the E/SE.
.LONG TERM...(Tonight through Thursday)
ISSUED AT 329 AM CST FRI DEC 25 2015
Major rain event is still unfolding across parts of central and
southeast Illinois this weekend as deep-layer southwesterly flow
establishes itself across the region. As upper low cuts off over
the Desert Southwest and a corresponding ridge develops downstream
across the eastern CONUS, the Ohio River Valley frontal boundary
will lift northward into central Illinois late tonight into
Saturday. The front will then become parallel to the upper flow and
stall across the area. With baroclinic zone in place, plenty of
Gulf of Mexico moisture flowing northward, and weak upper waves
tracking through the southwest flow to provide enhanced lift...a
prolonged period of moderate to heavy rain will develop this
weekend. Models have continued to slow the process however, with
tonight now remaining mostly dry. Have lowered PoPs to just
slight chance across all but the far S/SE accordingly. As front
stalls, rain will begin in earnest on Saturday, then continue
through Saturday night. Thanks to increasing instability, may
even see a few thunderstorms as well. As seen for the past
several model runs, a northern stream short-wave tracking from the
Northern Plains into the Great Lakes will push the front further
south on Sunday. 00z Dec 25 models are in good agreement that
the boundary will drop well south of the Ohio River, resulting in
decreasing rain chances Sunday/Sunday night. In fact, have
dropped PoPs altogether along/north of a Rushville to Bloomington
line during the afternoon and as far south as the I-72 corridor by
evening. Further south, rain will continue to fall across the
remainder of the area through Sunday night.
A vigorous wave coming off the Pacific will eventually eject the
Desert Southwest closed upper low northeastward early next week,
with the latest models now in much better agreement concerning the
timing of this process. The exact track of the low still remains in
question however, which poses some big challenges to the PoP/precip
type forecast late Sunday night through Monday night. ECMWF remains
the further west with the track...taking the corresponding surface
low from near St. Louis midday Monday to Chicago by midnight.
Meanwhile both the GFS and GEM are further east...with the low
tracking from western Kentucky to northwest Ohio during that time
frame. Will follow the more consistent ECMWF here, which keeps the
KILX CWA warmer and results in mostly liquid precip. May see a
period of light freezing rain on the northern periphery of the
precip as it returns northward late Sunday night into Monday:
however, with warm nose aloft at 5-6C and surface temps only
slightly below freezing across the north, think any ice accumulation
will be minimal. Based on expected surface temps, will mention
freezing rain along/north of a Rushville...to Lincoln...to Danville
line. Temps will edge above freezing everywhere toward midday
Monday, resulting in a change over to all rain. As the low
approaches, may even see a few thunderstorms south of the I-72
corridor. Once the low tracks into the southern Great Lakes, enough
cold air will be pulled down behind it to support a change over to
snow or a rain/snow mix along/north of a Taylorville to Danville
line Monday night. Will need to keep an eye on this, as any
eastward deviation of the low track will lead to more snow and
possible accumulations across the area.
Precip will come to an end on Tuesday, with storm total rainfall
from tonight through Monday night ranging from around 1 inch
northwest of the Illinois River...to as much as 5-6 inches
along/south of I-70. With so much rain expected to fall on already
wet soil and the potential for thunderstorms to produce excessive
rainfall rates, will be issuing a Flash Flood Watch for areas
along/southeast of a Danville to Taylorville line starting midday
Saturday and ending Monday evening. Main concerns will be rapid
rises on area creeks/streams and urban flooding in poor drainage
areas.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 600 AM CST FRI DEC 25 2015
Satellite images show MVFR/IFR ceilings approaching PIA and SPI
on increasing NW winds. The eastward progress of the clouds has
been slowed by the wind becoming more northerly with time, so the
arrival of MVFR/IFR conditions has been delayed until 13z. HRRR
model output indicates the low clouds will only be near PIA and
SPI for a couple hours, then retreat back to the west as they
dissipate in turbulent mixing.
High pressure building into Illinois from the northwest should
provide clearing skies this afternoon, with winds shifting around
to the east-northeast by late afternoon. Wind speeds should remain
less than 10kt until they become northeast, then they will
increase to 10-13kt as the pressure gradient tightens.
A frontal boundary stalled to the southeast of IL will gradually
lift northward later tonight, in response to a sharpening of the
upper trough across the Rockies. MVFR clouds and light fog will
expand northward later tonight as a result. Rain chances will
increase as well, but we held off on any mention of rain before
12z Sat morning. Better rain chances should come just after 12z.
&&
.ILX Watches/Warnings/Advisories...
Flash Flood Watch from Saturday afternoon through Monday
afternoon for ILZ052-054>057-061>063-066>068-071>073.
&&
$$
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS GOODLAND KS
823 AM MST FRI DEC 25 2015
.UPDATE...
ISSUED AT 819 AM MST FRI DEC 25 2015
LIGHT PRECIPITATION TAKING A BIT LONGER TO EXIT THE AREA...SO HAVE
EXTENDED CHANCES FOR SNOW AS A RESULT. ALSO INCREASED CHANCES FOR
SNOW LATE THIS AFTERNOON OVER YUMA COUNTY DUE TO A BAND OF LOW
LEVEL FRONTOGENESIS DEVELOPING THERE CO-LOCATED WITH THE FRONT.
STILL NOT SURE HOW QUICKLY AND HOW MUCH OF THE PRECIPITATION WILL
MOVE ACROSS THE AREA TONIGHT. WILL SEE WHAT THE LATEST HIGH
RESOLUTION DATA SAYS. WILL ALSO NEED TO DETERMINE WHEN/WHERE THE
SNOW CHANGES TO FREEZING DRIZZLE DUE TO THE SATURATED LAYER
BECOMING VERY SHALLOW AS IT MOVES EAST WITH THE FRONT.
UPDATE ISSUED AT 654 AM MST FRI DEC 25 2015
BASED ON SOUNDINGS HAVE INCREASED THE WINDS FOR THIS AFTERNOON
BEHIND THE WARM FRONT. GUSTS UP TO 30 MPH CAN BE EXPECTED BY EARLY
AFTERNOON.
UPDATE ISSUED AT 527 AM MST FRI DEC 25 2015
UPDATED THE GRIDS AND ZONES TO ADD SOME ISOLATED FLURRIES IN THE
EASTERN FA. THE HRRR MODEL INDICATES THAT THE FLURRIES SHOULD END
AROUND 15Z THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 209 AM MST FRI DEC 25 2015
SOUTHWEST FLOW WILL PERSIST OVER THE CENTRAL PLAINS FROM TODAY
THROUGH SATURDAY NIGHT WITH A RIDGE BUILDING INTO THE ROCKIES AND
THEN THE PLAINS SUNDAY AND SUNDAY NIGHT. A SURFACE LOW WILL BE
PRESENT OVER CENTRAL COLORADO TODAY. THIS AREA OF LOW PRESSURE WILL
SHIFT EAST INTO WESTERN KANSAS THIS EVENING AND THEN MOVE INTO
EASTERN KANSAS AS A COLD FRONT DIVES SOUTH ACROSS THE REGION. HIGH
PRESSURE WILL MOVE INTO THE CENTRAL PLAINS SATURDAY AND RESIDE OVER
HT AREA THROUGH SUNDAY NIGHT.
DYNAMICS START MOVING INTO THE FA LATE THIS AFTERNOON AND EVENING
BUT MOISTURE IS LIMITED TO THE FAR NORTHWEST FA WHERE THERE WILL BE
SLIGHT CHANCE POPS LATE THIS AFTERNOON INCREASING TO CHANCE POPS
THIS EVENING. FORECAST SOUNDINGS ACROSS THE FA INDICATE THE
POSSIBILITY OF SOME LIGHT FREEZING DRIZZLE AND PATCHY FOG FOR THE
EVENING. A DRY SLOT WILL MOVE NORTHWARD INTO THE FA BY 06Z SATURDAY.
CONSEQUENTLY WILL LOWER POPS OVER THE FAR NORTHWEST TO SLIGHT
CHANCE. DYNAMICS AND MOISTURE DECREASE ON SATURDAY AS THE UPPER LOW
SHIFTS FAR TO THE SOUTH REMOVING ANY POTENTIAL FOR PRECIPITATION.
CONSEQUENTLY POPS WILL BE NIL THROUGH SUNDAY. IF THE SYSTEM TAKES A
SLOWER AND MORE NORTHERLY TRACK SUNDAY NIGHT THERE COULD BE A SLIGHT
CHANCE OF LIGHT SNOW ACROSS THE SOUTHEAST FA. THE GFS MODEL IS
FASTER AND IF ITS SOLUTION BECOMES A REALITY THERE WILL BE NO
PRECIPITATION IN THE SOUTHEAST SUNDAY NIGHT.
MAX TEMPERATURES TODAY SHOULD WARM TO THE MID 40S WITH THE EXCEPTION
OF UPPER 30S ACROSS THE FAR NORTHERN FA. A COLD FRONT TONIGHT WILL
KEEP DAYTIME TEMPERATURES FROM RISING MUCH ABOVE THE MORNING LOWS.
DAYTIME TEMPERATURES SATURDAY SHOULD RANGE FROM THE MID TEENS IN THE
NORTHWEST TO THE MID 20S IN THE EAST. MAX TEMPERATURES SUNDAY
SHOULD BE IN THE MID 20S. MIN TEMPERATURES TONIGHT SHOULD RANGE
FROM THE TEENS IN THE NORTHWEST TO THE MID 20S IN THE EAST. MIN
TEMPERATURES SATURDAY AND SUNDAY NIGHTS SHOULD RANGE FROM THE UPPER
SINGLE DIGITS IN THE NORTHWEST TO THE MID AND UPPER TEENS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 209 AM MST FRI DEC 25 2015
THE EXTENDED PERIOD IS CONTINUING TO FOCUS/MONITOR THE IMPACT OF THE
CLOSED LOW ON THE CWA...IF ANY IMPACT AT ALL.
MONDAY...THE CLOSED LOW IN BOTH THE GFS AND EUROPEAN IS LOCATED OVER
THE NORTH EASTERN SIDE OF TEXAS INTO OKLAHOMA/ARKANSAS. BUT A FEW
DIFFERENCES ARE...ONE...THE STRENGTH OF THE LOW. THE GFS HAS IT
WEAKER WHEREAS THE EUROPEAN HAS IT MUCH STRONGER. SECOND...THE RIDGE
IN THE EAST/SOUTHEAST OF THE CONUS. THE GFS HAS IT BREAKING DOWN AND
PUSHING SOUTH QUICKER THAN THE EUROPEAN...WHICH IS PLAYING A STRONG
ROLE IN THE MOVEMENT OF THE LOW...WHICH IS WHY THE EUROPEAN STILL
HAS POPS IN THE FORECAST OVER THE CWA AND THE GFS DOES NOT. AGAIN
THE CR EXTENDED INITIALIZATION IS FAVORING THE EUROPEAN...BUT AS WE
GET CLOSER TO THE EVENT POPS MY NEED TO BE LOWERED EVEN MORE IF THE
GFS TRACT HOLDS MORE WATER.
TUESDAY...AFTER THE CLOSED LOW MOVES EAST OF THE CWA THERE IS A
UPPER LEVEL TROUGH THAT WILL MOVE INTO THE AREA TUESDAY NIGHT THAT
HAS POTENTIAL TO BRING SLIGHT CHANCES FOR LIGHT SNOW. BUT THE GFS IS
DRIER THAN THE EUROPEAN...SO POPS THAT WERE KEPT IN THE FORECAST ARE
DEPENDENT ON THE EUROPEAN...ONCE AGAIN.
WEDNESDAY/THURSDAY...CONDITIONS START TO DRY OUT. IT IS FAR OUT IN
THE EXTENDED BUT THE GFS HAS THE SAME TROUGH THAT MOVED INTO THE CWA
TUESDAY NIGHT CONTINUING TO IMPACT THE HIGH PLAINS...WHICH WILL
CONTINUE TO KEEP TEMPERATURES DOWN. THE EUROPEAN HAS MORE OF A ZONAL
FLOW OVER THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 430 AM MST FRI DEC 25 2015
VFR CONDITIONS SHOULD PERSIST AT KGLD AND KMCK UNTIL THIS EVENING
WHEN FORECAST SOUNDINGS INDICATE AT LEAST MVFR CONDITIONS. THE
SOUNDINGS INDICATE THAT THOSE CONDITIONS SHOULD CLEAR OUT AFTER 06Z
AS A COLD FRONT MOVES THROUGH WITH VFR RETURNING FOR THE
REMAINDER OF THE FORECAST PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...FS
LONG TERM...CLT
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
655 AM MST FRI DEC 25 2015
.UPDATE...
ISSUED AT 654 AM MST FRI DEC 25 2015
BASED ON SOUNDINGS HAVE INCREASED THE WINDS FOR THIS AFTERNOON
BEHIND THE WARM FRONT. GUSTS UP TO 30 MPH CAN BE EXPECTED BY EARLY
AFTERNOON.
UPDATE ISSUED AT 527 AM MST FRI DEC 25 2015
UPDATED THE GRIDS AND ZONES TO ADD SOME ISOLATED FLURRIES IN THE
EASTERN FA. THE HRRR MODEL INDICATES THAT THE FLURRIES SHOULD END
AROUND 15Z THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 209 AM MST FRI DEC 25 2015
SOUTHWEST FLOW WILL PERSIST OVER THE CENTRAL PLAINS FROM TODAY
THROUGH SATURDAY NIGHT WITH A RIDGE BUILDING INTO THE ROCKIES AND
THEN THE PLAINS SUNDAY AND SUNDAY NIGHT. A SURFACE LOW WILL BE
PRESENT OVER CENTRAL COLORADO TODAY. THIS AREA OF LOW PRESSURE WILL
SHIFT EAST INTO WESTERN KANSAS THIS EVENING AND THEN MOVE INTO
EASTERN KANSAS AS A COLD FRONT DIVES SOUTH ACROSS THE REGION. HIGH
PRESSURE WILL MOVE INTO THE CENTRAL PLAINS SATURDAY AND RESIDE OVER
HT AREA THROUGH SUNDAY NIGHT.
DYNAMICS START MOVING INTO THE FA LATE THIS AFTERNOON AND EVENING
BUT MOISTURE IS LIMITED TO THE FAR NORTHWEST FA WHERE THERE WILL BE
SLIGHT CHANCE POPS LATE THIS AFTERNOON INCREASING TO CHANCE POPS
THIS EVENING. FORECAST SOUNDINGS ACROSS THE FA INDICATE THE
POSSIBILITY OF SOME LIGHT FREEZING DRIZZLE AND PATCHY FOG FOR THE
EVENING. A DRY SLOT WILL MOVE NORTHWARD INTO THE FA BY 06Z SATURDAY.
CONSEQUENTLY WILL LOWER POPS OVER THE FAR NORTHWEST TO SLIGHT
CHANCE. DYNAMICS AND MOISTURE DECREASE ON SATURDAY AS THE UPPER LOW
SHIFTS FAR TO THE SOUTH REMOVING ANY POTENTIAL FOR PRECIPITATION.
CONSEQUENTLY POPS WILL BE NIL THROUGH SUNDAY. IF THE SYSTEM TAKES A
SLOWER AND MORE NORTHERLY TRACK SUNDAY NIGHT THERE COULD BE A SLIGHT
CHANCE OF LIGHT SNOW ACROSS THE SOUTHEAST FA. THE GFS MODEL IS
FASTER AND IF ITS SOLUTION BECOMES A REALITY THERE WILL BE NO
PRECIPITATION IN THE SOUTHEAST SUNDAY NIGHT.
MAX TEMPERATURES TODAY SHOULD WARM TO THE MID 40S WITH THE EXCEPTION
OF UPPER 30S ACROSS THE FAR NORTHERN FA. A COLD FRONT TONIGHT WILL
KEEP DAYTIME TEMPERATURES FROM RISING MUCH ABOVE THE MORNING LOWS.
DAYTIME TEMPERATURES SATURDAY SHOULD RANGE FROM THE MID TEENS IN THE
NORTHWEST TO THE MID 20S IN THE EAST. MAX TEMPERATURES SUNDAY
SHOULD BE IN THE MID 20S. MIN TEMPERATURES TONIGHT SHOULD RANGE
FROM THE TEENS IN THE NORTHWEST TO THE MID 20S IN THE EAST. MIN
TEMPERATURES SATURDAY AND SUNDAY NIGHTS SHOULD RANGE FROM THE UPPER
SINGLE DIGITS IN THE NORTHWEST TO THE MID AND UPPER TEENS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 209 AM MST FRI DEC 25 2015
THE EXTENDED PERIOD IS CONTINUING TO FOCUS/MONITOR THE IMPACT OF THE
CLOSED LOW ON THE CWA...IF ANY IMPACT AT ALL.
MONDAY...THE CLOSED LOW IN BOTH THE GFS AND EUROPEAN IS LOCATED OVER
THE NORTH EASTERN SIDE OF TEXAS INTO OKLAHOMA/ARKANSAS. BUT A FEW
DIFFERENCES ARE...ONE...THE STRENGTH OF THE LOW. THE GFS HAS IT
WEAKER WHEREAS THE EUROPEAN HAS IT MUCH STRONGER. SECOND...THE RIDGE
IN THE EAST/SOUTHEAST OF THE CONUS. THE GFS HAS IT BREAKING DOWN AND
PUSHING SOUTH QUICKER THAN THE EUROPEAN...WHICH IS PLAYING A STRONG
ROLE IN THE MOVEMENT OF THE LOW...WHICH IS WHY THE EUROPEAN STILL
HAS POPS IN THE FORECAST OVER THE CWA AND THE GFS DOES NOT. AGAIN
THE CR EXTENDED INITIALIZATION IS FAVORING THE EUROPEAN...BUT AS WE
GET CLOSER TO THE EVENT POPS MY NEED TO BE LOWERED EVEN MORE IF THE
GFS TRACT HOLDS MORE WATER.
TUESDAY...AFTER THE CLOSED LOW MOVES EAST OF THE CWA THERE IS A
UPPER LEVEL TROUGH THAT WILL MOVE INTO THE AREA TUESDAY NIGHT THAT
HAS POTENTIAL TO BRING SLIGHT CHANCES FOR LIGHT SNOW. BUT THE GFS IS
DRIER THAN THE EUROPEAN...SO POPS THAT WERE KEPT IN THE FORECAST ARE
DEPENDENT ON THE EUROPEAN...ONCE AGAIN.
WEDNESDAY/THURSDAY...CONDITIONS START TO DRY OUT. IT IS FAR OUT IN
THE EXTENDED BUT THE GFS HAS THE SAME TROUGH THAT MOVED INTO THE CWA
TUESDAY NIGHT CONTINUING TO IMPACT THE HIGH PLAINS...WHICH WILL
CONTINUE TO KEEP TEMPERATURES DOWN. THE EUROPEAN HAS MORE OF A ZONAL
FLOW OVER THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 430 AM MST FRI DEC 25 2015
VFR CONDITIONS SHOULD PERSIST AT KGLD AND KMCK UNTIL THIS EVENING
WHEN FORECAST SOUNDINGS INDICATE AT LEAST MVFR CONDITIONS. THE
SOUNDINGS INDICATE THAT THOSE CONDITIONS SHOULD CLEAR OUT AFTER 06Z
AS A COLD FRONT MOVES THROUGH WITH VFR RETURNING FOR THE
REMAINDER OF THE FORECAST PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...FS
LONG TERM...CLT
AVIATION...FS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
528 AM MST FRI DEC 25 2015
.UPDATE...
ISSUED AT 527 AM MST FRI DEC 25 2015
UPDATED THE GRIDS AND ZONES TO ADD SOME ISOLATED FLURRIES IN THE
EASTERN FA. THE HRRR MODEL INDICATES THAT THE FLURRIES SHOULD END
AROUND 15Z THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 209 AM MST FRI DEC 25 2015
SOUTHWEST FLOW WILL PERSIST OVER THE CENTRAL PLAINS FROM TODAY
THROUGH SATURDAY NIGHT WITH A RIDGE BUILDING INTO THE ROCKIES AND
THEN THE PLAINS SUNDAY AND SUNDAY NIGHT. A SURFACE LOW WILL BE
PRESENT OVER CENTRAL COLORADO TODAY. THIS AREA OF LOW PRESSURE WILL
SHIFT EAST INTO WESTERN KANSAS THIS EVENING AND THEN MOVE INTO
EASTERN KANSAS AS A COLD FRONT DIVES SOUTH ACROSS THE REGION. HIGH
PRESSURE WILL MOVE INTO THE CENTRAL PLAINS SATURDAY AND RESIDE OVER
HT AREA THROUGH SUNDAY NIGHT.
DYNAMICS START MOVING INTO THE FA LATE THIS AFTERNOON AND EVENING
BUT MOISTURE IS LIMITED TO THE FAR NORTHWEST FA WHERE THERE WILL BE
SLIGHT CHANCE POPS LATE THIS AFTERNOON INCREASING TO CHANCE POPS
THIS EVENING. FORECAST SOUNDINGS ACROSS THE FA INDICATE THE
POSSIBILITY OF SOME LIGHT FREEZING DRIZZLE AND PATCHY FOG FOR THE
EVENING. A DRY SLOT WILL MOVE NORTHWARD INTO THE FA BY 06Z SATURDAY.
CONSEQUENTLY WILL LOWER POPS OVER THE FAR NORTHWEST TO SLIGHT
CHANCE. DYNAMICS AND MOISTURE DECREASE ON SATURDAY AS THE UPPER LOW
SHIFTS FAR TO THE SOUTH REMOVING ANY POTENTIAL FOR PRECIPITATION.
CONSEQUENTLY POPS WILL BE NIL THROUGH SUNDAY. IF THE SYSTEM TAKES A
SLOWER AND MORE NORTHERLY TRACK SUNDAY NIGHT THERE COULD BE A SLIGHT
CHANCE OF LIGHT SNOW ACROSS THE SOUTHEAST FA. THE GFS MODEL IS
FASTER AND IF ITS SOLUTION BECOMES A REALITY THERE WILL BE NO
PRECIPITATION IN THE SOUTHEAST SUNDAY NIGHT.
MAX TEMPERATURES TODAY SHOULD WARM TO THE MID 40S WITH THE EXCEPTION
OF UPPER 30S ACROSS THE FAR NORTHERN FA. A COLD FRONT TONIGHT WILL
KEEP DAYTIME TEMPERATURES FROM RISING MUCH ABOVE THE MORNING LOWS.
DAYTIME TEMPERATURES SATURDAY SHOULD RANGE FROM THE MID TEENS IN THE
NORTHWEST TO THE MID 20S IN THE EAST. MAX TEMPERATURES SUNDAY
SHOULD BE IN THE MID 20S. MIN TEMPERATURES TONIGHT SHOULD RANGE
FROM THE TEENS IN THE NORTHWEST TO THE MID 20S IN THE EAST. MIN
TEMPERATURES SATURDAY AND SUNDAY NIGHTS SHOULD RANGE FROM THE UPPER
SINGLE DIGITS IN THE NORTHWEST TO THE MID AND UPPER TEENS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 209 AM MST FRI DEC 25 2015
THE EXTENDED PERIOD IS CONTINUING TO FOCUS/MONITOR THE IMPACT OF THE
CLOSED LOW ON THE CWA...IF ANY IMPACT AT ALL.
MONDAY...THE CLOSED LOW IN BOTH THE GFS AND EUROPEAN IS LOCATED OVER
THE NORTH EASTERN SIDE OF TEXAS INTO OKLAHOMA/ARKANSAS. BUT A FEW
DIFFERENCES ARE...ONE...THE STRENGTH OF THE LOW. THE GFS HAS IT
WEAKER WHEREAS THE EUROPEAN HAS IT MUCH STRONGER. SECOND...THE RIDGE
IN THE EAST/SOUTHEAST OF THE CONUS. THE GFS HAS IT BREAKING DOWN AND
PUSHING SOUTH QUICKER THAN THE EUROPEAN...WHICH IS PLAYING A STRONG
ROLE IN THE MOVEMENT OF THE LOW...WHICH IS WHY THE EUROPEAN STILL
HAS POPS IN THE FORECAST OVER THE CWA AND THE GFS DOES NOT. AGAIN
THE CR EXTENDED INITIALIZATION IS FAVORING THE EUROPEAN...BUT AS WE
GET CLOSER TO THE EVENT POPS MY NEED TO BE LOWERED EVEN MORE IF THE
GFS TRACT HOLDS MORE WATER.
TUESDAY...AFTER THE CLOSED LOW MOVES EAST OF THE CWA THERE IS A
UPPER LEVEL TROUGH THAT WILL MOVE INTO THE AREA TUESDAY NIGHT THAT
HAS POTENTIAL TO BRING SLIGHT CHANCES FOR LIGHT SNOW. BUT THE GFS IS
DRIER THAN THE EUROPEAN...SO POPS THAT WERE KEPT IN THE FORECAST ARE
DEPENDENT ON THE EUROPEAN...ONCE AGAIN.
WEDNESDAY/THURSDAY...CONDITIONS START TO DRY OUT. IT IS FAR OUT IN
THE EXTENDED BUT THE GFS HAS THE SAME TROUGH THAT MOVED INTO THE CWA
TUESDAY NIGHT CONTINUING TO IMPACT THE HIGH PLAINS...WHICH WILL
CONTINUE TO KEEP TEMPERATURES DOWN. THE EUROPEAN HAS MORE OF A ZONAL
FLOW OVER THE CWA.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 430 AM MST FRI DEC 25 2015
VFR CONDITIONS SHOULD PERSIST AT KGLD AND KMCK UNTIL THIS EVENING
WHEN FORECAST SOUNDINGS INDICATE AT LEAST MVFR CONDITIONS. THE
SOUNDINGS INDICATE THAT THOSE CONDITIONS SHOULD CLEAR OUT AFTER 06Z
AS A COLD FRONT MOVES THROUGH WITH VFR RETURNING FOR THE
REMAINDER OF THE FORECAST PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...FS
SHORT TERM...FS
LONG TERM...CLT
AVIATION...FS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
632 AM EST FRI DEC 25 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EST FRI DEC 25 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A BROAD TROF DOMINATING
MOST OF W AND CNTRL NAMERICA WHILE A STRONG RIDGE IS LOCATED JUST
OFF THE E COAST OF THE CONUS. RESULT IS SW FLOW OVER THE UPPER GREAT
LAKES EARLY THIS MORNING. LATEST RAP ANALYSIS SHOWS MOISTURE TRAPPED
BLO 4-5KFT WITH LOWEST TEMPS IN THE MOIST LAYER RIGHT AROUND
-10C. KMQT RADAR IS HINTING AT VERY LIGHT LES OVER ERN LAKE
SUPERIOR AT TIMES...AND MONTREAL RIVER ONTARIO RADAR DOES IN FACT
SHOW A FEW LIGHT LES BANDS. TO THE W...WEAK SHORTWAVE MOVING ACROSS
NRN MN IS GENERATING SOME -SN WHICH IS NOW MOVING OUT OVER WRN LAKE
SUPERIOR.
IN THE NEAR TERM...AS WEAK FORCING PROVIDED BY UPSTREAM SHORTWAVE
PASSES OVER LAKE SUPERIOR DURING THE NEXT SEVERAL HRS...AREA OF -SN
WILL BECOME ENHANCED OVER THE RELATIVELY WARM WATERS. WILL BE SHORT-
LIVED...BUT UNDER WSW WINDS...THE KEWEENAW MIGHT SEE UP TO AN INCH
OF SNOW THIS MORNING BEFORE -SHSN DIMINISH...THEN END EARLY THIS
AFTN. OTHERWISE...MODELS ARE FAIRLY AGGRESSIVE IN DECREASING CLOUDS
THIS AFTN AWAY FROM THE KEWEENAW WHERE WINDS REMAIN OFF LAKE
SUPERIOR THRU THE DAY. ALWAYS A TOUGH CALL THIS TIME OF YEAR WITH
LOW SUN ANGLE...BUT OPTED TO TREND SKY TO MOSTLY SUNNY GIVEN
OPTIMISTIC INDICATION FROM THE MAJORITY OF MODELS. BEST CHC FOR
CLEARING WILL BE IN THE AREAS THAT HAVE DOWNSLOPING UNDER A WSW
WIND.
TONIGHT...WITH THE POTENTIAL FOR LOW CLOUDS TO BE MOSTLY OUT OF THE
AREA AND WITH ONLY HIGH CLOUDS ARRIVING AND THICKENING FROM THE W
AND SW....TEMPS MAY HAVE AN OPPORTUNITY TO FALL DECENTLY UNDER
LIGHT/CALM WIND. BIAS CORRECTED REGIONAL AND GLOBAL CANADIAN MODEL
TEMPS TYPICALLY PICK UP ON RADIATIONAL COOLING BEST AND HAVE
INCORPORATED THEIR OUTPUT IN MIN TEMP FCST. BOTH SHOW MINS AS LOW AS
AROUND 10F OVER THE INTERIOR W. FOR NOW...LOWERED MINS TO THE MID
TEENS AT THE LOWEST. THE INCREASING/THICKENING HIGH CLOUDS WILL BE
THE HARBINGER OF A SNOW EVENT FOR SAT/SAT EVENING GENERATED BY A
DISTRUBANCE LIFTING OUT OF THE WRN TROF AND RIGHT ENTRANCE OF UPPER
JET EXTENDING ACROSS MN AND NRN ONTARIO. THE FORCING BEGINS TO
SPREAD INTO WRN UPPER MI LATE TONIGHT...BUT THERE IS PLENTY OF DRY
AIR TO SATURATE IN THE MID TO LOWER LEVELS. THAT SHOULD DELAY PCPN
FROM REACHING THE GROUND FOR A TIME. LEANED TOWARD THE MODELS
SHOWING SLOWER PCPN DEVELOPMENT...RESULTING IN CHC POPS INTO FAR WRN
UPPER MI LATE TONIGHT WITH SCHC AS FAR E AS ROUGHLY
HOUGHTON/BARAGA/CRYSTAL FALLS BY 12Z.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 455 AM EST FRI DEC 25 2015
THE MAIN FOCUS IS ON THE POTENTIAL FOR MODERATE SNOWFALL ACROSS THE
NORTHWEST HALF OF UPPER MI ON SATURDAY AND SATURDAY EVENING.
SATURDAY AND SATURDAY EVENING...THE PHASING OF A SHORTWAVE TROUGH
EJECTING FROM A LARGER TROUGH OVER THE SW STATES...AND ANOTHER
SHORTWAVE TROUGH DIGGING SE FROM BRITISH COLUMBIA...WILL BE STARTING
ACROSS THE UPPER AND MID MS VALLEY SAT MORNING. AHEAD OF THESE
TROUGHS...MODEST ISENTROPIC LIFT ON THE 290 TO 300K THETA SURFACES
UNDER SLOPING MID-LEVEL FGEN AND THE RIGHT ENTRANCE OF A
STRENGTHENING UPPER JET STREAK WILL SUPPORT MODERATE SNOW ACROSS THE
NW HALF OF THE CWA FROM AROUND DAYBREAK SATURDAY INTO SATURDAY
EVENING. THE BEST LIFT FROM WAA/ISENTROPIC ASCENT AND THE ACTIVE MID-
LEVEL FGEN WILL BE SOMEWHAT DISCONNECTED...RESULTING IN THE
POTENTIAL FOR A LOCALLY HEAVY SNOW BAND EMBEDDED WITHIN MORE
WIDESPREAD LIGHT TO MODERATE SNOW FOR ALL BUT THE EASTERN CWA. MODEL
GUIDANCE HAS BEEN MOVING AROUND THE BAND OF HEAVIER PRECIP...SO
PEGGING THE LOCATION WITH HIGHEST SNOW AMOUNTS REMAINS A CHALLENGE.
WITH THAT SAID...HIGH RES GUIDANCE IS WIDELY SUPPORTING A NARROW
COUNTY-WIDE SWATH OF 0.5 TO 0.7 INCHES OF PRECIP FROM 12Z SAT TO 06Z
SUNDAY. WITH A DEEP DGZ LOCATED WITHIN THE ACTIVE FGEN LAYER...SNOW
RATIOS SHOULD BE RATHER HIGH AT AROUND 17 OR 18 TO 1. AWAY FROM THE
MAIN FGEN BAND...RATIOS WILL BE CLOSER TO 14 OR 15 TO 1. PUTTING
THIS ALL TOGETHER...CHANCES LOOK FAIRLY GOOD FOR A SOLID 3 TO 6
INCHES OF SNOW FOR THE NW HALF OF THE CWA...WITH THE POTENTIAL FOR A
NARROW BAND OF UP TO 9 INCHES. THIS IS ESPECIALLY TRUE IF THE BAND
ALIGNS WITH LOW-LEVEL NE UPSLOPE ACROSS THE NORTH CENTRAL.
GIVEN THE RATHER LOW CONFIDENCE ON BAND PLACEMENT...INCLUDING THE
POTENTIAL FOR THE BAND TO REMAIN OVER LAKE SUPERIOR...AND GIVEN THAT
THE MAIN SNOW IS STILL GREATER THAN 30 HOURS OUT...HAVE OPTED TO
ISSUE A SPS FOR THE NW HALF HIGHLIGHTING THE SNOW ALONG WITH MINOR
POST-HOLIDAY TRAVEL DISRUPTIONS.
REST OF THE PERIOD...LIGHT TO SOMETIMES MODERATE LES WILL LINGER
ALONG LAKE SUPERIOR THROUGH SUNDAY NIGHT FOR THE N AND NW WIND
SNOWBELTS AS -15 TO -20C H8 AIR FILTERS OVER LAKE SUPERIOR ON
SUNDAY. GENERALLY SHALLOW INVERSIONS AT OR LESS THAN 4KFT WILL
HINDER OVERALL LES INTENSITY. BUT WITH THE CLOUD LAYER COMPLETELY
WITHIN THE DGZ AT TIMES...VERY FLUFFY SNOW CAN BE EXPECTED. IF
CLOUDS CAN CLEAR ENOUGH SUNDAY NIGHT...TEMPS MAY FALL TO NEAR ZERO
ACROSS THE INTERIOR WEST WHERE FRESH SNOW HAS FALLEN.
LOTS OF UNCERTAINTY AS THE UPPER LOW THAT WILL FORM OVER THE
U.S./MEXICO BORDER LOOKS TO BREAK DOWN AND SHIFT THROUGH THE REGION
TUE INTO TUE NIGHT. OVERALL GUIDANCE CONTINUES TO KEEP THE MAIN
TROUGH TO THE SE OF THE CWA ON TUESDAY...WITH THE ECMWF REMAINING
THE OUTLIER BY BRINGING THE TROUGH NEAR UPPER MI. WILL CONTINUE TO
HEDGE TOWARD A DRIER SOLUTION...WITH LES POSSIBLE FOR THE EAST WIND
SNOW BELTS OF LAKE SUPERIOR AND LAKE MI.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 630 AM EST FRI DEC 25 2015
LOW-LEVEL MOISTURE TRAPPED UNDER INVERSION WILL CONTINUE TO YIELD
MVFR CIGS THIS MORNING AT KIWD/KSAW. AT KCMX...IFR CIGS SHOULD LIFT
TO LOW MVFR THIS MORNING...AND THERE MAY BE SOME -SHSN UNDER WSW
FLOW OFF LAKE SUPERIOR. THIS AFTN...IT APPEARS LOW CLOUDS WILL
SCATTER OUT TO VFR CONDITIONS AT KIWD/KSAW. MEANWHILE...CONTINUED
WINDS OFF LAKE SUPERIOR WILL MAINTAIN MVFR CONDITIONS AT KCMX...AND
THAT WILL PROBABLY PERSIST THRU TONIGHT. AT KIWD/KSAW...VFR
CONDITIONS WILL CONTINUE TONIGHT. HOWEVER...SNOW DEVELOPING TO THE
SW SHOULD REACH KIWD LATE TONIGHT. MVFR CONDITIONS WILL DEVELOP AT
KIWD AROUND THE END OF THE FCST PERIOD WITH FURTHER DETERIORATION TO
IFR SAT MORNING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EST FRI DEC 25 2015
WESTERLY WINDS WILL INCREASE TO 15-25KT TODAY AHEAD OF A HIGH PRES
RIDGE WHICH ARRIVES TONIGHT. WINDS MAY REACH 20-30KT AROUND THE TIP
OF THE KEWEENAW PENINSULA. UNDER THE HIGH PRES RIDGE...WINDS WILL
DIMINISH TO UNDER 15KT TONIGHT. AS THE RIDGE SHIFTS N AND A LOW PRES
TROF SETS UP FROM THE SRN PLAINS TO THE LOWER GREAT LAKES...NE WINDS
WILL INCREASE SAT...REACHING AS HIGH AS 20-30KT OVER WRN LAKE
SUPERIOR. WINDS OF 15-25KT TO 20-30KT WILL THEN MOSTLY BE THE RULE
SUN THRU TUE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KLUBER
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
512 AM EST FRI DEC 25 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EST FRI DEC 25 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A BROAD TROF DOMINATING
MOST OF W AND CNTRL NAMERICA WHILE A STRONG RIDGE IS LOCATED JUST
OFF THE E COAST OF THE CONUS. RESULT IS SW FLOW OVER THE UPPER GREAT
LAKES EARLY THIS MORNING. LATEST RAP ANALYSIS SHOWS MOISTURE TRAPPED
BLO 4-5KFT WITH LOWEST TEMPS IN THE MOIST LAYER RIGHT AROUND
-10C. KMQT RADAR IS HINTING AT VERY LIGHT LES OVER ERN LAKE
SUPERIOR AT TIMES...AND MONTREAL RIVER ONTARIO RADAR DOES IN FACT
SHOW A FEW LIGHT LES BANDS. TO THE W...WEAK SHORTWAVE MOVING ACROSS
NRN MN IS GENERATING SOME -SN WHICH IS NOW MOVING OUT OVER WRN LAKE
SUPERIOR.
IN THE NEAR TERM...AS WEAK FORCING PROVIDED BY UPSTREAM SHORTWAVE
PASSES OVER LAKE SUPERIOR DURING THE NEXT SEVERAL HRS...AREA OF -SN
WILL BECOME ENHANCED OVER THE RELATIVELY WARM WATERS. WILL BE SHORT-
LIVED...BUT UNDER WSW WINDS...THE KEWEENAW MIGHT SEE UP TO AN INCH
OF SNOW THIS MORNING BEFORE -SHSN DIMINISH...THEN END EARLY THIS
AFTN. OTHERWISE...MODELS ARE FAIRLY AGGRESSIVE IN DECREASING CLOUDS
THIS AFTN AWAY FROM THE KEWEENAW WHERE WINDS REMAIN OFF LAKE
SUPERIOR THRU THE DAY. ALWAYS A TOUGH CALL THIS TIME OF YEAR WITH
LOW SUN ANGLE...BUT OPTED TO TREND SKY TO MOSTLY SUNNY GIVEN
OPTIMISTIC INDICATION FROM THE MAJORITY OF MODELS. BEST CHC FOR
CLEARING WILL BE IN THE AREAS THAT HAVE DOWNSLOPING UNDER A WSW
WIND.
TONIGHT...WITH THE POTENTIAL FOR LOW CLOUDS TO BE MOSTLY OUT OF THE
AREA AND WITH ONLY HIGH CLOUDS ARRIVING AND THICKENING FROM THE W
AND SW....TEMPS MAY HAVE AN OPPORTUNITY TO FALL DECENTLY UNDER
LIGHT/CALM WIND. BIAS CORRECTED REGIONAL AND GLOBAL CANADIAN MODEL
TEMPS TYPICALLY PICK UP ON RADIATIONAL COOLING BEST AND HAVE
INCORPORATED THEIR OUTPUT IN MIN TEMP FCST. BOTH SHOW MINS AS LOW AS
AROUND 10F OVER THE INTERIOR W. FOR NOW...LOWERED MINS TO THE MID
TEENS AT THE LOWEST. THE INCREASING/THICKENING HIGH CLOUDS WILL BE
THE HARBINGER OF A SNOW EVENT FOR SAT/SAT EVENING GENERATED BY A
DISTRUBANCE LIFTING OUT OF THE WRN TROF AND RIGHT ENTRANCE OF UPPER
JET EXTENDING ACROSS MN AND NRN ONTARIO. THE FORCING BEGINS TO
SPREAD INTO WRN UPPER MI LATE TONIGHT...BUT THERE IS PLENTY OF DRY
AIR TO SATURATE IN THE MID TO LOWER LEVELS. THAT SHOULD DELAY PCPN
FROM REACHING THE GROUND FOR A TIME. LEANED TOWARD THE MODELS
SHOWING SLOWER PCPN DEVELOPMENT...RESULTING IN CHC POPS INTO FAR WRN
UPPER MI LATE TONIGHT WITH SCHC AS FAR E AS ROUGHLY
HOUGHTON/BARAGA/CRYSTAL FALLS BY 12Z.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 455 AM EST FRI DEC 25 2015
THE MAIN FOCUS IS ON THE POTENTIAL FOR MODERATE SNOWFALL ACROSS THE
NORTHWEST HALF OF UPPER MI ON SATURDAY AND SATURDAY EVENING.
SATURDAY AND SATURDAY EVENING...THE PHASING OF A SHORTWAVE TROUGH
EJECTING FROM A LARGER TROUGH OVER THE SW STATES...AND ANOTHER
SHORTWAVE TROUGH DIGGING SE FROM BRITISH COLUMBIA...WILL BE STARTING
ACROSS THE UPPER AND MID MS VALLEY SAT MORNING. AHEAD OF THESE
TROUGHS...MODEST ISENTROPIC LIFT ON THE 290 TO 300K THETA SURFACES
UNDER SLOPING MID-LEVEL FGEN AND THE RIGHT ENTRANCE OF A
STRENGTHENING UPPER JET STREAK WILL SUPPORT MODERATE SNOW ACROSS THE
NW HALF OF THE CWA FROM AROUND DAYBREAK SATURDAY INTO SATURDAY
EVENING. THE BEST LIFT FROM WAA/ISENTROPIC ASCENT AND THE ACTIVE MID-
LEVEL FGEN WILL BE SOMEWHAT DISCONNECTED...RESULTING IN THE
POTENTIAL FOR A LOCALLY HEAVY SNOW BAND EMBEDDED WITHIN MORE
WIDESPREAD LIGHT TO MODERATE SNOW FOR ALL BUT THE EASTERN CWA. MODEL
GUIDANCE HAS BEEN MOVING AROUND THE BAND OF HEAVIER PRECIP...SO
PEGGING THE LOCATION WITH HIGHEST SNOW AMOUNTS REMAINS A CHALLENGE.
WITH THAT SAID...HIGH RES GUIDANCE IS WIDELY SUPPORTING A NARROW
COUNTY-WIDE SWATH OF 0.5 TO 0.7 INCHES OF PRECIP FROM 12Z SAT TO 06Z
SUNDAY. WITH A DEEP DGZ LOCATED WITHIN THE ACTIVE FGEN LAYER...SNOW
RATIOS SHOULD BE RATHER HIGH AT AROUND 17 OR 18 TO 1. AWAY FROM THE
MAIN FGEN BAND...RATIOS WILL BE CLOSER TO 14 OR 15 TO 1. PUTTING
THIS ALL TOGETHER...CHANCES LOOK FAIRLY GOOD FOR A SOLID 3 TO 6
INCHES OF SNOW FOR THE NW HALF OF THE CWA...WITH THE POTENTIAL FOR A
NARROW BAND OF UP TO 9 INCHES. THIS IS ESPECIALLY TRUE IF THE BAND
ALIGNS WITH LOW-LEVEL NE UPSLOPE ACROSS THE NORTH CENTRAL.
GIVEN THE RATHER LOW CONFIDENCE ON BAND PLACEMENT...INCLUDING THE
POTENTIAL FOR THE BAND TO REMAIN OVER LAKE SUPERIOR...AND GIVEN THAT
THE MAIN SNOW IS STILL GREATER THAN 30 HOURS OUT...HAVE OPTED TO
ISSUE A SPS FOR THE NW HALF HIGHLIGHTING THE SNOW ALONG WITH MINOR
POST-HOLIDAY TRAVEL DISRUPTIONS.
REST OF THE PERIOD...LIGHT TO SOMETIMES MODERATE LES WILL LINGER
ALONG LAKE SUPERIOR THROUGH SUNDAY NIGHT FOR THE N AND NW WIND
SNOWBELTS AS -15 TO -20C H8 AIR FILTERS OVER LAKE SUPERIOR ON
SUNDAY. GENERALLY SHALLOW INVERSIONS AT OR LESS THAN 4KFT WILL
HINDER OVERALL LES INTENSITY. BUT WITH THE CLOUD LAYER COMPLETELY
WITHIN THE DGZ AT TIMES...VERY FLUFFY SNOW CAN BE EXPECTED. IF
CLOUDS CAN CLEAR ENOUGH SUNDAY NIGHT...TEMPS MAY FALL TO NEAR ZERO
ACROSS THE INTERIOR WEST WHERE FRESH SNOW HAS FALLEN.
LOTS OF UNCERTAINTY AS THE UPPER LOW THAT WILL FORM OVER THE
U.S./MEXICO BORDER LOOKS TO BREAK DOWN AND SHIFT THROUGH THE REGION
TUE INTO TUE NIGHT. OVERALL GUIDANCE CONTINUES TO KEEP THE MAIN
TROUGH TO THE SE OF THE CWA ON TUESDAY...WITH THE ECMWF REMAINING
THE OUTLIER BY BRINGING THE TROUGH NEAR UPPER MI. WILL CONTINUE TO
HEDGE TOWARD A DRIER SOLUTION...WITH LES POSSIBLE FOR THE EAST WIND
SNOW BELTS OF LAKE SUPERIOR AND LAKE MI.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1205 AM EST FRI DEC 25 2015
ENOUGH LOW LEVEL MOISTURE WILL LINGER TO SUPPORT MARGINAL VFR CIGS
AT IWD AND MVFR CIGS AT CMX AND SAW THROUGH MUCH OF THE NIGHT.
CONDITIONS AT IWD AND SAW WILL IMPROVE TO VFR DURING THE MORNING
WHILE CMX REMAINS MVFR TIL MIDDAY WITH UPSLOPE WESTERLY FLOW
CONTINUING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EST FRI DEC 25 2015
WESTERLY WINDS WILL INCREASE TO 15-25KT TODAY AHEAD OF A HIGH PRES
RIDGE WHICH ARRIVES TONIGHT. WINDS MAY REACH 20-30KT AROUND THE TIP
OF THE KEWEENAW PENINSULA. UNDER THE HIGH PRES RIDGE...WINDS WILL
DIMINISH TO UNDER 15KT TONIGHT. AS THE RIDGE SHIFTS N AND A LOW PRES
TROF SETS UP FROM THE SRN PLAINS TO THE LOWER GREAT LAKES...NE WINDS
WILL INCREASE SAT...REACHING AS HIGH AS 20-30KT OVER WRN LAKE
SUPERIOR. WINDS OF 15-25KT TO 20-30KT WILL THEN MOSTLY BE THE RULE
SUN THRU TUE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KLUBER
AVIATION...MZ
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
607 AM CST FRI DEC 25 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 405 AM CST FRI DEC 25 2015
MAIN FORECAST CHALLENGES COMING UP FOR TODAY/TONIGHT WILL BE
TRYING TO FORECAST ANY MOMENTS OF CLEAR SKIES TODAY...FOLLOWED BY
TIMING IN SNOWFALL TONIGHT.
SHORTWAVE RIDGING AND ASSOCIATED HEIGHT RISES ARE MOVING INTO MN
THIS MORNING OUT AHEAD OF THE NEXT TROUGH DIGGING ACROSS THE
ROCKIES. THE FIRST PIECE OF ENERGY FROM THIS WRN TROUGH WILL COME
OUT OF THE 4-CORNERS REGION TODAY AND END UP IN NORTH CENTRAL MN BY
SATURDAY MORNING AND WILL BE THE PRIMARY PRECIPITATION DRIVER.
OVERNIGHT WE SAW SOME CLEARING WORK INTO WRN MN ON THE BACK SIDE OF
A DEPARTING HIGH...GIVING US HOPE WE MAY GET A RARE GLIMPSE AT THE
SUN THIS DECEMBER. HOWEVER...AS THAT HIGH HAS MOVED EAST...SOUTHERLY
WINDS HAVE BEEN DEVELOPING...WHICH ARE BRINGING UP MORE LOW STRATUS
OUT OF IOWA. AS A RESULT...HAVE STARTED TRENDING OUR SKY COVER GRIDS
TOWARD THE HRRR...WHICH IS TO CALL FOR ANOTHER GRAY DAY WITH LOW
STRATUS LIKELY HANGING TOUGH FOR ALL BUT MAYBE FAR WRN MN. THOUGH WE
ARE EXPECTING MAINLY CLOUDY SKIES AGAIN...DID NOT CHANGE THE
FORECAST HIGHS MUCH...AS THOSE WINDS OF A SOUTHERN EXPOSURE WILL
ALSO BRING IN WARMER AIR...WITH 925MB TEMPS EXPECTED TO RISE 4C-8C
TODAY OVER WHAT WAS SEEN THURSDAY...ALLOWING HIGHS TODAY TO BE ABOUT
5 TO 10 DEGREES WARMER THAN WHAT WAS SEEN YESTERDAY.
FOR TONIGHT...EXPECTING PRECIP TO COME AT US IN TWO WAVES. THE FIRST
WILL SPREAD FROM SW TOWARD NE MN BETWEEN 3Z AND 9Z. THIS WAVE IS
ASSOCIATED WITH THE UPPER WAVE AND PV ADVECTION. THE SECOND PUSH
WILL MAINLY COME AFTER 9Z SATURDAY AND IS ASSOCIATED WITH THE MAIN
PUSH OF WAA AND LIFT AROUND THE 290K ISENTROPIC SURFACE. THE FIRST
WAVE LOOKS TO COME IN MAINLY WEST OF A ST. JAMES...WESTERN TWIN
CITIES METRO...OSCEOLA WI LINE...WITH WAVE TWO NOT REACHING TO THE
EAST OF THE I-35 CORRIDOR UNTIL AFTER 12Z SATURDAY. FOR
POPS...FOLLOWED A BLEND OF THE HIRES NAM AND ARW BASED CAMS...WHICH
RESULTED IN A SIGNIFICANT DELAY IN POPS FROM SOUTH CENTRAL INTO EAST
CENTRAL MN AND WRN WI. FOR P-TYPE...STILL SEEING SIGNS IN NAM/GFS
BUFR SOUNDINGS OF A GREATER THAN 0C WARM NOSE WORKING INTO SOUTH
CENTRAL MN...WHICH MAY RESULT IN A IP/SN MIX ALONG THE I-90
CORRIDOR...BUT OUTSIDE OF THAT...ITS FINALLY COLD ENOUGH TO PRODUCE
A MAINLY SNOW EVENT IN DECEMBER.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 405 AM CST FRI DEC 25 2015
THE FOCUS ON THE LONG TERM WAS SPENT ON SATURDAY WITH THE
POTENTIAL FOR HEAVY SNOW IN PORTIONS OF OUR WESTERN AND NORTHERN
FA. ALTHOUGH QUITE A BIT OF SPREAD IS SEEN WITH THE AXIS OF THE
HEAVIER QPF BETWEEN THE DETERMINISTIC SOLUTIONS...THE CAMS ARE
MORE FOCUSED FROM WEST CENTRAL MN TO KDLH. OUR FORECAST FOLLOWS
THE CAMS WITH A PUSH TO THE WEST AND NORTH WITH THE HEAVIEST
SNOWFALL.
THE CULPRIT IS A MID LEVEL LOW PRESSURE SYSTEM THAT IS PROGGED TO
BE OVER NEBRASKA SATURDAY MORNING. THE LOW IS FORECAST TO MOVE
NORTHEAST ACROSS WEST CENTRAL MN BY LATE MORNING AND REACH
NORTHWEST WI BY EVENING. THE LOW IS EXPECTED TO WEAKEN DURING THE
DAY AS IT MERGES IN WITH A NORTHERN STREAM SHORT WAVE. AS THIS
WAVE MOVES NORTHEAST...CROSS SECTION DATA SHOWS STRONG MID LEVEL
-EPV ALONG WITH NEGATIVE THETA-E LAPSE RATES LEADING TO THE
POTENTIAL FOR UPRIGHT CONVECTION. IN ADDITION...EVEN THOUGH THE
DETERMINISTIC RUNS ARE NOT IN VERY GOOD AGREEMENT ON THE
QPF...THEY DO AGREE ON A VERY STRONG PV ANOMALY MOVING NORTHEAST
ALONG A KABR-KINL LINE ON SATURDAY. THE SREF PLUMES ARE
INTERESTING IN THAT THE ARW MEMBERS ARE PRETTY SOLID ON THE
HEAVIER AMOUNTS OF QPF FROM WEST CENTRAL MN TO KDLH WHILE THE NMB
CORES ARE KIND OF DIVIDED INTO THREE CAMPS..ONE LIKE THE
ARW...ONE WITH VERY LIGHT TO NO QPF ACROSS THE FA AND A THIRD
FOCUSED NEAR THE MN/IA BORDER. THIS LAST SET IS SIMILAR TO THE
CANADIAN OUTPUT.
IN THE END...WE DECIDED TO ISSUE A WINTER STORM WATCH FOR MUCH OF
WEST CENTRAL MN WHERE CONFIDENCE IS HIGH ON 6 TO 8 INCHES OF SNOW
OCCURRING BETWEEN MIDNIGHT AND NOON ON SATURDAY. LOCAL
ACCUMULATIONS OF 10 INCHES ARE POSSIBLE...MAINLY IN FAR WESTERN
LAC QUI PARLE AND CANBY COUNTIES DUE TO SOME UPSLOPE. IN
ADDITION...NORTHERLY WINDS WILL BE INCREASING TO 15 TO 25 MPH
ACROSS WEST CENTRAL MN SATURDAY AFTERNOON LEADING TO CONSIDERABLE
BLOWING AND DRIFTING SNOW WITH SIGNIFICANTLY REDUCED VISIBILITIES.
WE THOUGHT ABOUT STRETCHING THE WATCH NORTHEAST TOWARD LAKE MILLE
LACS BUT CONFIDENCE WAS NOT HIGH ENOUGH MAINLY DUE TO THE
WEAKENING OF THE UPPER AIR FEATURES IN THE AFTERNOON.
STILL...THESE AREAS HAVE A SOLID 5 INCH SNOW ACCUMULATION
FORECAST.
ANOTHER CONCERN ON SATURDAY IS A MID LEVEL DRY PUNCH THAT WILL
WORK AT LEAST INTO SOUTHERN MN DURING THE MORNING AND INTO
WESTERN WI IN THE AFTERNOON. THIS SHOULD LIMIT THE SNOW
ACCUMULATION ALONG AND SOUTH OF A MANKATO TO EAU CLAIRE LINE TO A
FEW INCHES WITH MOST OF THIS COMING LATE FRIDAY NIGHT/SATURDAY
MORNING. THE PROBLEM IS THE PRECIP TYPE ACROSS SOUTHERN MN AND
PORTIONS OF WEST CENTRAL WI WITH SLEET AND SOME FREEZING RAIN
REMAINING POSSIBLE. FOR THE TWIN CITIES METRO...SNOW AMOUNTS RANGE
FROM 5 INCHES IN THE NORTHWEST METRO TO 3 INCHES IN THE SOUTHEAST
METRO. THIS IS DEFINITELY ON THE HIGH SIDE OF THE SREF PLUMES
WHERE AROUND 2 TO 3 INCHES IS FORECAST. AGAIN...THE DRY SLOT WILL
PLAY A BIG ROLE ON SNOW AMOUNTS LOCALLY.
IN THE WAKE OF THIS SYSTEM...COLD AND DRY CONDITIONS WILL COVER
THE AREA SUNDAY AND MONDAY. THERE REMAINS UNCERTAINTY ON THE NEXT
SYSTEM FOR TUESDAY AND WEDNESDAY. THE GFS REMAINS STEADFAST ON
KEEP A VIGOROUS LOW PRESSURE SYSTEM MOVING NORTHEAST FROM TEXAS TO
OUT SOUTH AND EAST. THE ECMWF IS FINALLY STARTING TO BACK DOWN AS
WELL IN KEEPING THE MAJORITY OF THE SYSTEM TO OUR SOUTH.
HOWEVER...THE ECMWF QUICKLY FINDS ANOTHER SHORT WAVE TO DRIVE
NORTHEAST ACROSS THE REGION LATE TUESDAY AND TUESDAY NIGHT WITH
SOME LIGHT SNOW OCCURRING. MORE SNOW IS POSSIBLE WEDNESDAY AND
THURSDAY AS A LARGE UPPER TROUGH DEVELOPED OVER THE CONUS BETWEEN
THE ROCKIES AND THE APPALACHIAN MOUNTAINS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 607 AM CST FRI DEC 25 2015
BIGGEST CHANGE TO THE GOING TAFS WAS TO REMOVE THE IMPROVEMENTS TO
VFR WE HAD WITH THE 6Z TAFS. CLEARING THAT HAD DEVELOPED IN WRN MN
EARLIER TONIGHT HAS SINCE FILLED IN WITH STRATUS/FOG COMING UP
OUT OF IOWA. TRENDED CIG FORECAST TOWARD THE PESSIMISTIC HRRR AND
AWAY FROM THE OVERLY OPTIMISTIC LAV GUIDANCE. FOR SNOW
TONIGHT...EXPECT A HEAVY BURST OF SNOW WILL BE COMING INTO SW MN
BETWEEN 2Z AND 4Z AND QUICKLY SPREAD NORTH ACROSS THE MN TERMINALS
THIS EVENING. WILL LIKELY SEE 1/4SM TO 1/2SM VSBY WITH THIS BAND
OF SNOW...BUT LEFT THAT OUT UNTIL WE GET A BETTER HANDEL ON
TIMING.
KMSP...LOOKING UNLIKELY THAT WE SEE MVFR CIGS CLEAR OUT TODAY.
SNOW LATE TONIGHT INTO TUESDAY LOOKS A BIT TRICKY AS THERE WILL
LIKELY BE TWO WAVES OF SNOW. THE FIRST LOOKS TO BE A QUICK
HITTING...THOUGH HEAVY BURST OF SNOW THAT COMES THROUGH BETWEEN 6
AND 10Z. THERE WILL LIKELY BE A 2 TO 4 HOUR LULL IN SNOWFALL OR AT
LEAST SNOWFALL INTENSITY BEFORE A SECOND BURST OF SNOW COMES
THROUGH DURING THE MORNING.
/OUTLOOK FOR KMSP/
SUN...MVFR POSSIBLE EARLY...THEN VFR. WINDS NW 5-10 KTS.
MON...VFR. WINDS E 5-10 KTS.
TUE...VFR. WINDS NE 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WINTER STORM WATCH FROM LATE TONIGHT THROUGH SATURDAY AFTERNOON
FOR MNZ054>057-064-065-073.
&&
$$
SHORT TERM...MPG
LONG TERM...RAH
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
649 AM EST FRI DEC 25 2015
.SYNOPSIS...
A WEAK COLD FRONT WILL PUSH SOUTHEAST ACROSS THE AREA
TODAY THEN STALL AND MOVE BACK NORTH TO LAKE ERIE SATURDAY AS LOW
PRESSURE MOVES ALONG THE FRONT ACROSS THE REGION SATURDAY NIGHT
PULLING THE FRONT BACK TO THE SOUTHEAST. THE FRONT WILL WAVER BACK
AND FORTH AGAIN AS ANOTHER LOW MOVES THROUGH LAKE ERIE TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
HRRR AND RAP MODELS NOW STARTING TO SHOW BAND OF LIGHT RAIN AND
SPRINKLES ACROSS THE CWA TRYING TO HANG AROUND LONGER THAN WHAT
WAS INDICATED EARLIER. LATEST RADAR IMAGES SEEMS TO VERIFY THAT
THIS WILL BE THE CASE SO WILL ADJUST MORNING FORECAST TO BETTER
REFLECT MORE OF A THREAT FOR RAIN.
THE COMBINATION OF CLOUDS BEING SLOW TO DECREASE AND WINDS
TURNING TO THE N AND NE WILL KEEP TEMPS FROM RISING MUCH TODAY WITH
HIGHS FROM THE LOWER 50S NEAR LAKE ERIE TO THE MID TO UPPER 50S IN
THE FAR SOUTH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
A SERIES OF UPPER S/W`S AND SURFACE LOWS WILL MOVE OUT OF THE
TEXAS AREA AND HEAD NE ACROSS THE LERI/LOWER MI REGION SAT THRU
TUE. THE SW UPPER FLOW WILL CAUSE OVERRUNNING TO START UP THIS
EVENING WITH DEEP MOISTURE PUSHING BACK NORTH ACROSS THE CWA WITH
RAIN DEVELOPING SOUTH TO NORTH LATE TONIGHT THRU SAT. THE MODELS
ARE A BIT SLOWER WITH THE NORTH PUSH OF RAIN SO WILL ADJUST RAMP
UP OF POPS ACCORDINGLY. THE AIRMASS BECOME MORE UNSTABLE BY SAT
NIGHT SO SOME THUNDER MAY OCCUR SAT NIGHT INTO EARLY SUN BUT
MAINLY IN THE SOUTH. MODERATE TO LOCALLY HEAVY RAIN IS EXPECTED
WITH AN INCH TO AN INCH AND THREE QUARTERS OF QPF OVER MUCH OF THE
CWA BY THE TIME THIS FIRST BATCH OF RAIN SETTLES BACK TO THE SOUTH
OF THE CWA FOR SUN NIGHT. THE AREA SHOULD BE ABLE TO HANDLE THIS
MUCH RAIN WITHOUT SIGNIFICANT FLOODING PROBLEMS ALTHOUGH A FEW
ISOLATED SPOTS COULD SEE SOME LOCAL ISSUES.
THE BREAK FROM RAIN WILL BE SHORT-LIVED AS THE SECOND LOW WILL LEAD
TO A SIMILAR PROCESS FOR THE AREA WITH RAIN SPREADING BACK NORTH
LATE SUN NIGHT AND MON THEN HANGING AROUND INTO TUE. COLDER AIR
TRAPPED IN THE LOWER LEVELS MAY TRY AND HANG ON LONG ENOUGH SUN
NIGHT SO THAT IF THE PRECIP ARRIVES QUICK ENOUGH THERE COULD BE SOME
SNOW OR FZRA IN THE FAR NW OR NE. FOR NOW WILL KEEP MOST OF THE
PRECIP SOUTH OF THE CWA THRU SUN NIGHT SO DON`T THINK PRECIP TYPE
WILL END UP BEING A PROBLEM. THE PRECIP TYPE ISSUE COULD BE MORE OF
A PROBLEM EARLY MON NIGHT IN THE NE AS MORE SIGNIFICANT PRECIP
STARTS TO OCCUR BUT WARMER AIR QUICKLY SURGES NORTH THAT WILL CHANGE
ALL PRECIP TO RAIN. WILL SHOW RISING TEMPS BY LATE MON NIGHT.
ITS THE HEAVIER RAIN WITH THIS SYSTEM THAT WILL BE MUCH MORE LIKELY
TO LEAD TO FLOODING PROBLEMS LATE MON NIGHT OR TUE AS THE AREA WILL
BE SATURATED FROM THE WEEKEND`S HEAVY RAINS.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
LOW PRESSURE WILL MOVE THROUGH THE CENTRAL LAKES ON TUESDAY WITH
A COLD FRONT EAST OF THE COUNTY WARNING AREA(CWA) BY AFTERNOON.
SHOWERS WILL MAINLY BE IN THE MORNING BUT COULD LINGER ACROSS NE
OH/NW PA INTO THE AFTERNOON. A BRIEF PERIOD OF UPPER LEVEL RIDGING
SHOULD BE ENOUGH TO ALLOW FOR A DRY PERIOD BEGINNING TUESDAY NIGHT
INTO THE FIRST HALF OF WEDNESDAY. THE NEXT OF THE ENDLESS WAVES IN
THE SOUTHERN JET STREAM WILL ARRIVE BY WEDNESDAY AFTERNOON OR
EVENING BRINGING ANOTHER ROUND OF SHOWERS TO THE REGION. A COLDER
TYPICAL WINTER SETUP WILL THEN TAKE CONTROL OF THE CWA THURSDAY
INTO FRIDAY. THE COLD AIR SPILLING ACROSS THE 5 TO 8 DEGREES ABOVE
AVERAGE WATER TEMPERATURES OF LAKE ERIE WILL CAUSE SNOW SHOWERS TO
DEVELOP. WESTERLY WINDS WILL DIRECT THE SNOW INTO THE PRIMARY
SNOWBELT BUT WITH A GENERAL UPPER LEVEL TROUGH ACROSS THE REGION
JUST ABOUT ANY LOCATIONS COULD SEE A FLURRY OR LIGHT SNOW. WILL
NOT MAKE AN ATTEMPT ON SNOW AMOUNTS AT THIS POINT SINCE MODELS ARE
DIFFERING ON THE TIMING OF JET ENERGY MOVING THROUGH THE UPPER
LEVEL TROUGH.
AFTER HIGHS IN THE 40S TO AROUND 50 ON TUESDAY IT WILL BECOME
COOLER. HIGHS BY THURSDAY WILL DIP TO THE UPPER 30S TO NEAR 40 WHICH
IS MUCH CLOSER TO SEASONAL AVERAGES. EVEN COOLER BY FRIDAY.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
PLENTY OF VIRGA/VERY LIGHT RAIN SEEN ON RADAR THIS MORNING. AREA
SOUNDINGS INDICATE A VERY DRY LAYER AT THE LOWER LEVELS OF THE
ATMOSPHERE MAKING IT DIFFICULT FOR CEILING TO LOWER. CURRENTLY ALL
LOCATIONS ARE VFR BUT THERE IS SOME MVFR CEILING 50 MILES OR SO
SOUTHEAST OF COLUMBUS. SOME OF THIS LOWER LEVEL CLOUD COVER MAY
CLIP LOCATIONS NEAR AND SOUTH OF A CANTON TO YOUNGSTOWN LINE. DID
NOT PLACE THIS IN ANY OF THE SOUTHERN TAF SITES WITH THE
EXPECTATION THAT A WEAK COLD FRONT/WIND SHIFT WILL BE ABLE TO KEEP
THESE CLOUDS TO THE SOUTH. WINDS WILL GRADUALLY SHIFT TO THE
NORTHEAST OVERNIGHT BUT SHOULD BE UNDER 12 KNOTS. AS LIFT OVER THE
WARM FRONT INCREASES TOWARD SUNRISE ON SATURDAY SOUTHERN AREAS
MAY BEGIN TO SEE SOME LOW END VFR CEILINGS.
OUTLOOK...NON VFR CEILINGS SPREADING NORTH OVER WHOLE AREA BY
SATURDAY AFTERNOON WITH INCREASING SHOWERS. NON VFR IN SHOWERS
WILL PERSIST INTO SUNDAY AFTERNOON. BRIEF LULL BETWEEN STORMS
SUNDAY NIGHT THEN NON VFR RETURNING MONDAY AFTERNOON INTO TUESDAY.
&&
.MARINE...
A STATIONARY BOUNDARY WAS LOCATED ACROSS SOUTH CENTRAL OHIO THIS
MORNING. THIS BOUNDARY WILL BE THE PATH THAT LOW PRESSURE TAKES AS
IT MOVES ACROSS OHIO SATURDAY NIGHT. AS THE LOW APPROACHES TONIGHT
THE NORTHEAST TO EAST WINDS WILL INCREASE AND PERSIST INTO
SATURDAY. THE LONGER FETCH AND STRONGER WINDS WILL CAUSE WAVES TO
BUILD TO SMALL CRAFT LEVELS AT SOME POINT TONIGHT INTO SATURDAY
AFTERNOON. AS THE LOW PASSES NEAR THE SOUTH SHORE OF LAKE ERIE
SATURDAY NIGHT WINDS SHOULD DECREASE. HOWEVER IN THE WAKE OF THE
LOW NORTHERLY WINDS WILL INCREASE AND CAUSE WAVES TO BUILD ONCE
AGAIN. QUESTION AT THIS POINT IN TIME IS DO WE ALLOW THE SMALL
CRAFT ADVISORY TO DROP FOR A FEW HOURS OR NOT. THESE DETAILS WILL
BE DETERMINED BY SATURDAY AFTERNOON. WINDS WILL DECREASE FOR A
SHORT PERIOD SUNDAY NIGHT. NORTHEAST WINDS TO RETURN TO THE 15 TO
25 KNOT RANGE AGAIN ON MONDAY AND REMAIN ELEVATED INTO MONDAY
NIGHT WITH THE NEXT AREA OF LOW PRESSURE MOVING INTO THE REGION
FROM THE WESTERN GULF OF MEXICO.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...MULLEN
MARINE...ADAMS/MULLEN
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
606 AM EST FRI DEC 25 2015
.SYNOPSIS... A WEAK COLD FRONT WILL PUSH SOUTHEAST ACROSS THE AREA
TODAY THEN STALL AND MOVE BACK NORTH TO LAKE ERIE SATURDAY AS LOW
PRESSURE MOVES ALONG THE FRONT ACROSS THE REGION SATURDAY NIGHT
PULLING THE FRONT BACK TO THE SOUTHEAST. THE FRONT WILL WAVER BACK
AND FORTH AGAIN AS ANOTHER LOW MOVES THROUGH LAKE ERIE TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM FRIDAY EVENING/... HRRR AND RAP MODELS NOW
STARTING TO SHOW BAND OF LIGHT RAIN AND SPRINKLES ACROSS THE CWA
TRYING TO HANG AROUND LONGER THAN WHAT WAS INDICATED EARLIER. LATEST
RADAR IMAGES SEEMS TO VERIFY THAT THIS WILL BE THE CASE SO WILL
ADJUST MORNING FORECAST TO BETTER REFLECT MORE OF A THREAT FOR
RAIN.
THE COMBINATION OF CLOUDS BEING SLOW TO DECREASE AND WINDS
TURNING TO THE N AND NE WILL KEEP TEMPS FROM RISING MUCH TODAY WITH
HIGHS FROM THE LOWER 50S NEAR LAKE ERIE TO THE MID TO UPPER 50S IN
THE FAR SOUTH.
&&
.SHORT TERM /6 PM FRIDAY EVENING THROUGH MONDAY NIGHT/... A SERIES
OF UPPER S/W`S AND SURFACE LOWS WILL MOVE OUT OF THE TEXAS AREA AND
HEAD NE ACROSS THE LERI/LOWER MI REGION SAT THRU TUE. THE SW UPPER
FLOW WILL CAUSE OVERRUNNING TO START UP THIS EVENING WITH DEEP
MOISTURE PUSHING BACK NORTH ACROSS THE CWA WITH RAIN DEVELOPING
SOUTH TO NORTH LATE TONIGHT THRU SAT. THE MODELS ARE A BIT SLOWER
WITH THE NORTH PUSH OF RAIN SO WILL ADJUST RAMP UP OF POPS
ACCORDINGLY. THE AIRMASS BECOME MORE UNSTABLE BY SAT NIGHT SO SOME
THUNDER MAY OCCUR SAT NIGHT INTO EARLY SUN BUT MAINLY IN THE SOUTH.
MODERATE TO LOCALLY HEAVY RAIN IS EXPECTED WITH AN INCH TO AN INCH
AND THREE QUARTERS OF QPF OVER MUCH OF THE CWA BY THE TIME THIS
FIRST BATCH OF RAIN SETTLES BACK TO THE SOUTH OF THE CWA FOR SUN
NIGHT. THE AREA SHOULD BE ABLE TO HANDLE THIS MUCH RAIN WITHOUT
SIGNIFICANT FLOODING PROBLEMS ALTHOUGH A FEW ISOLATED SPOTS COULD
SEE SOME LOCAL ISSUES.
THE BREAK FROM RAIN WILL BE SHORT-LIVED AS THE SECOND LOW WILL LEAD
TO A SIMILAR PROCESS FOR THE AREA WITH RAIN SPREADING BACK NORTH
LATE SUN NIGHT AND MON THEN HANGING AROUND INTO TUE. COLDER AIR
TRAPPED IN THE LOWER LEVELS MAY TRY AND HANG ON LONG ENOUGH SUN
NIGHT SO THAT IF THE PRECIP ARRIVES QUICK ENOUGH THERE COULD BE SOME
SNOW OR FZRA IN THE FAR NW OR NE. FOR NOW WILL KEEP MOST OF THE
PRECIP SOUTH OF THE CWA THRU SUN NIGHT SO DON`T THINK PRECIP TYPE
WILL END UP BEING A PROBLEM. THE PRECIP TYPE ISSUE COULD BE MORE OF
A PROBLEM EARLY MON NIGHT IN THE NE AS MORE SIGNIFICANT PRECIP
STARTS TO OCCUR BUT WARMER AIR QUICKLY SURGES NORTH THAT WILL CHANGE
ALL PRECIP TO RAIN. WILL SHOW RISING TEMPS BY LATE MON NIGHT.
ITS THE HEAVIER RAIN WITH THIS SYSTEM THAT WILL BE MUCH MORE LIKELY
TO LEAD TO FLOODING PROBLEMS LATE MON NIGHT OR TUE AS THE AREA WILL
BE SATURATED FROM THE WEEKEND`S HEAVY RAINS.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/... LOW PRESSURE WILL MOVE
THROUGH THE CENTRAL LAKES ON TUESDAY WITH A COLD FRONT EAST OF THE
COUNTY WARNING AREA(CWA) BY AFTERNOON. SHOWERS WILL MAINLY BE IN THE
MORNING BUT COULD LINGER ACROSS NE OH/NW PA INTO THE AFTERNOON. A
BRIEF PERIOD OF UPPER LEVEL RIDGING SHOULD BE ENOUGH TO ALLOW FOR A
DRY PERIOD BEGINNING TUESDAY NIGHT INTO THE FIRST HALF OF WEDNESDAY.
THE NEXT OF THE ENDLESS WAVES IN THE SOUTHERN JET STREAM WILL ARRIVE
BY WEDNESDAY AFTERNOON OR EVENING BRINGING ANOTHER ROUND OF SHOWERS
TO THE REGION. A COLDER TYPICAL WINTER SETUP WILL THEN TAKE CONTROL
OF THE CWA THURSDAY INTO FRIDAY. THE COLD AIR SPILLING ACROSS THE 5
TO 8 DEGREES ABOVE AVERAGE WATER TEMPERATURES OF LAKE ERIE WILL
CAUSE SNOW SHOWERS TO DEVELOP. WESTERLY WINDS WILL DIRECT THE SNOW
INTO THE PRIMARY SNOWBELT BUT WITH A GENERAL UPPER LEVEL TROUGH
ACROSS THE REGION JUST ABOUT ANY LOCATIONS COULD SEE A FLURRY OR
LIGHT SNOW. WILL NOT MAKE AN ATTEMPT ON SNOW AMOUNTS AT THIS POINT
SINCE MODELS ARE DIFFERING ON THE TIMING OF JET ENERGY MOVING
THROUGH THE UPPER LEVEL TROUGH.
AFTER HIGHS IN THE 40S TO AROUND 50 ON TUESDAY IT WILL BECOME
COOLER. HIGHS BY THURSDAY WILL DIP TO THE UPPER 30S TO NEAR 40 WHICH
IS MUCH CLOSER TO SEASONAL AVERAGES. EVEN COOLER BY FRIDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
CLOUDS HAVE BEEN SLOW TO LOWER THIS EVENING ACROSS THE REGION
WITH MAINLY JUST MID DECK AT OR ABOVE 8000 FT ACROSS THE REGION.
RADAR MOSAIC SHOWS LIGHT RETURNS OVER THE WESTERN PART OF THE
AREA WITH MOSTLY VIRGA AS ONLY A COUPLE OF LOCATIONS ARE
REPORTING VERY LIGHT RAIN. THIS PRECIPITATION SHOULD EXIT THE
REGION AND STRUGGLE TO MOISTEN THE BOUNDARY LAYER. WILL BACK OFF
THE MENTION OF FOG AND DELAY THE FORMATION OF LOWER CLOUDS AND
ALSO INCREASE THE HEIGHT OF THE LOWER CLOUD DECK. ONCE THE WEAK
DISTURBANCE MOVES TO THE EAST...WINDS WILL SHIFT TO THE NORTH.
LOWER CLOUDS SHOULD BEGIN TO SCATTER OUT THIS AFTERNOON.
OUTLOOK...NON VFR SE INTO FRI NIGHT SPREADING NORTH OVER WHOLE AREA
BY SAT THEN GETTING PUSHED BACK OFF TO THE SOUTH SUN INTO SUN NIGHT
BEFORE SPREADING BACK NORTH OVER THE AREA MON NIGHT AND TUE.
&&
.MARINE... A STATIONARY BOUNDARY WAS LOCATED ACROSS SOUTH CENTRAL
OHIO THIS MORNING. THIS BOUNDARY WILL BE THE PATH THAT LOW PRESSURE
TAKES AS IT MOVES ACROSS OHIO SATURDAY NIGHT. AS THE LOW APPROACHES
TONIGHT THE NORTHEAST TO EAST WINDS WILL INCREASE AND PERSIST INTO
SATURDAY. THE LONGER FETCH AND STRONGER WINDS WILL CAUSE WAVES TO
BUILD TO SMALL CRAFT LEVELS AT SOME POINT TONIGHT INTO SATURDAY
AFTERNOON. AS THE LOW PASSES NEAR THE SOUTH SHORE OF LAKE ERIE
SATURDAY NIGHT WINDS SHOULD DECREASE. HOWEVER IN THE WAKE OF THE LOW
NORTHERLY WINDS WILL INCREASE AND CAUSE WAVES TO BUILD ONCE AGAIN.
QUESTION AT THIS POINT IN TIME IS DO WE ALLOW THE SMALL CRAFT
ADVISORY TO DROP FOR A FEW HOURS OR NOT. THESE DETAILS WILL BE
DETERMINED BY SATURDAY AFTERNOON. WINDS WILL DECREASE FOR A SHORT
PERIOD SUNDAY NIGHT. NORTHEAST WINDS TO RETURN TO THE 15 TO 25 KNOT
RANGE AGAIN ON MONDAY AND REMAIN ELEVATED INTO MONDAY NIGHT WITH THE
NEXT AREA OF LOW PRESSURE MOVING INTO THE REGION FROM THE WESTERN
GULF OF MEXICO.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...ADAMS
NEAR TERM...ADAMS
SHORT TERM...ADAMS
LONG TERM...MULLEN
AVIATION...LAPLANTE/MULLEN
MARINE...ADAMS/MULLEN
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1037 AM EST FRI DEC 25 2015
.SYNOPSIS...
A STATIONARY FRONT WILL SLOWLY MOVE NORTH OF THE FORECAST AREA TODAY
AND THROUGH THE OVERNIGHT. THIS FRONT WILL STALL OUT OVER THE SOUTHERN
OHIO VALLEY...WHILE ATLANTIC HIGH PRESSURE BUILDS IN AND PERSISTS
THROUGH MONDAY. A MOIST LOW PRESSURE SYSTEM WILL APPROACH THE REGION
ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1015 AM...RAIN IS GRADUALLY BECOMING MORE PATCHY ACROSS
NORTHERN AND FAR WESTERN ZONES...AND HAS COMPLETELY ENDED ACROSS MUCH
OF THE REMAINDER OF THE AREA...AS THE POSITION OF THE UPPER JET IS
BECOMING LESS FAVORABLE FOR SUPPORTING UVV ACROSS THE FORECAST
AREA...WHILE THE FRONTAL ZONE HAS RETREATED INTO THE TENN AND OHIO
VALLEYS. PRECIP WILL THEREFORE GRADUALLY BECOME LESS OF AN ISSUE
THIS AFTERNOON INTO THIS EVENING. IN THE INTERIM...A QUASI-LINEAR
CONVECTIVE SYSTEM...ORIGINATING ALONG THE FRONT EARLIER THIS
MORNING...IS MOVING RATHER QUICKLY ACROSS SOUTHEAST TENN AND
NORTHERN ALABAMA ATTM. RADAR TRENDS INDICATE A RECENT SUBSTANTIVE
WEAKENING TREND...AS THE FEATURE IS DISPLACED FROM THE MORE ROBUST
BUOYANCY (ACROSS CENTRAL AL AND GA). THE WEAKENING TREND SHOULD
CONTINUE...BUT PERHAPS NOT BEFORE BRINGING A LOW-END SEVERE WEATHER
THREAT TO THE NC AND GA MTNS EARLY THIS AFTERNOON. PERHAPS THE
GREATER CONCERN WILL BE THE POTENTIAL FOR HEAVY RAIN AND LOCALIZED
FLASH FLOODING...AS ANTECEDENT CONDITIONS ARE QUITE DIRE ACROSS THE
AREA...AND IT WON/T TAKE MUCH IN THE WAY OF HEAVY RAINFALL FOR
SMALLER STREAMS TO BEGIN RESPONDING.
ATTM...IT/S DIFFICULT TO DETERMINE WHAT THE FATE OF ANY REMNANT QLCS
COOL POOL WILL BE ONCE IT EMERGES OFF THE HIGH TERRAIN DURING
MID/LATE AFTERNOON. THE WARM SECTOR AIR MASS SHOULD DESTABILIZE
SOMEWHERE IN THE 500 J/KG OF SBCAPE NEIGHBORHOOD...ALTHOUGH THE MORE
SHEARED ENVIRONMENT WILL BE WELL TO OUR WEST AND NW. SOME OF THE
MESOSCALE MODELS INDICATE VERY LITTLE ACTIVITY OUTSIDE THE MTNS THIS
PM...WHILE THE LATEST HRRR SEEMS TO WANT TO MAINTAIN DEEP CONVECTION
ALONG THE COLD POOL ACROSS MUCH OF THE CWA...WHICH IS A BIT OF A NEW
DEVELOPMENT. WILL KEEP POPS IN THE SLIGHT/LOW CHANCE RANGE ACROSS
THE PIEDMONT THIS AFTERNOON...BUT THIS WILL NEED TO BE REVISITED
LATER.
OTHERWISE...SYNOPTIC SETUP SHOULD BE NO SURPRISE...DEEP SOUTHWEST
FLOW ALOFT CONTINUES WITH UPPER RIDGE AND SURFACE HIGH OVER THE
ATLANTIC...CONTINUING TO PUMP AN ANOMALOUSLY WARM AIRMASS INTO
THE SOUTHEAST AND SOUTHERN APPALACHIANS. FROSTY WILL BE FEELING
THE PAIN TODAY ESPECIALLY AFTER SUCH A WARM MORNING...WITH RECORD
AFTERNOON HIGHS FORECAST FOR ASHEVILLE...AND ONLY A FEW DEGREES
LOWER THAN RECORDS FOR GSP AND CHARLOTTE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
AT 230 AM FRIDAY...ON SATURDAY MORNING AN UPPER RIDGE WILL BE
CENTERED NORTHEAST OF THE BAHAMAS...WHILE A TROUGH UPSTREAM WILL BE
OVER THE ROCKIES. BY SUNDAY AN UPPER LOW WILL CLOSE OFF IN THE BASE
OF THE UPPER LOW OVER OVER NORTHERN MX AND W TX...WHILE THE WESTERN
PERIPHERY OF THE RIDGE MAINTAINS ITS GRIP ON THE SOUTHEAST USA. THE
UPPER LOW APPROACHES THE LOWER MS RIVER VALLEY EARLY MONDAY.
AT THE SURFACE...ON SATURDAY MORNING A WARM FRONT WILL BE LIFTING N
TOWARD THE OH RIVER VALLEY...WHILE A COLD FRONT MOVES ACROSS THE
SOUTHERN PLAINS. A TIGHT PRESSURE GRADIENT BETWEEN THE FRONT AND AN
ATLANTIC SURFACE RIDGE WILL SUPPORT ROBUST GULF INFLOW FROM EAST TX
TO THE SOUTHERN APPALACHIAN. LOW LEVEL WINDS AHEAD OF THE FRONT
APPEAR TO SHIFT BACK AND FORTH BETWEEN THE S AND SW...FAVORING
UPSLOPE FLOW AND ISENTROPIC UPGLIDE WITH THE FORMER...AND NOT SO
WITH THE LATER.
TEMPERATURES WILL REMAIN ABOVE NORMAL...BUT WITH A DECREASING TREND
AS THE UPPER RIDGE BREAKS DOWN. WHILE INSTABILITY WILL BE SUFFICIENT
FOR THUNDERSTORMS ON SATURDAY...THE BEST SHEAR WILL BE TO THE NW OF
OUR AREA...LIMITING THE POTENTIAL FOR ORGANIZATION. ON SUNDAY THE
BEST INSTABILITY WILL BE TO OUR SE...AND THE BEST SHEAR TO OUR NW.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AT 230 AM FRIDAY...A WEAKENING UPPER LOW MOVES FROM THE LOWER MS
RIVER VALLEY ON MONDAY TO THE GREAT LAKES ON TUESDAY...WHILE THE
SOUTHEASTERN RIDGE DEAMPLIFIES SOMEWHAT. MEANWHILE...ANOTHER UPPER
LOW DROPS INTO THE WESTERN TROUGH. BY WEDNESDAY THE SOUTHEAST RIDGE
REAMPLIFIES AS THE FIRST UPPER LOW WEAKENS TO THE NORTH... WHILE THE
UPPER LOW UPSTREAM WEAKENS OVER THE PLAINS. BY THURSDAY THE UPPER
RIDGE PROGRESSES AND BROADENS...STRETCHING NEARLY FROM COAST TO
COAST ACROSS THE USA.
AT THE SURFACE...IT APPEARS THAT A WEDGE OF COOL AIR WILL SPREAD
DOWN THE EAST SLOPES OF THE APPALACHIANS BY TUESDAY MORNING... WHILE
A COLD FRONT REACHES EAST TN AND GA. WITH INCREASING S WINDS AHEAD
OF THE FRONT...SUBSTANTIAL ISENTROPIC UPGLIDE WILL BE PRESENT OVER
OUR AREA...SUPPORTING PRECIPITATION. THE FRONT SLOWLY CROSSES THE
MOUNTAINS ON TUESDAY...AND STALLS OVER THE PIEDMONT BY WEDNESDAY...
WITH GULF MOISTURE MOVING ALONG IT FROM THE SW. EARLY ON THURSDAY
ANOTHER COLD FRONT WITH ITS OWN MOISTURE APPROACHES THE MOUNTAINS
FROM THE NORTHWEST...RAPIDLY CROSSING OUR AREA AND REACHING THE GULF
STREAM BY FRIDAY. TEMPERATURES WILL TREND COOLER AS HEIGHTS FALL
ALOFT DUE TO THE BROADENING UPPER RIDGE...BUT REMAIN ABOVE NORMAL
AHEAD OF THE LAST COLD FRONT.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
AT KCLT AND ELSEWHERE EXCEPT KAVL...STILL VFR AT 12Z TAF TIME
WITH -SHRA OR AT LEAST VCSH. ALL GUIDANCE CONTINUES TO POINT
TO RAPIDLY LOWERING CONDITIONS IN THE NEXT COUPLE OF HOURS BUT
FRANKLY GUIDANCE HAS BEEN DOING THAT ALL NIGHT...AND CONFIDENCE
IS PRETTY LOW. REALLY DO EXPECT THAT AT SOME POINT RESTRICTIONS
WILL ROLL IN...WITH IFR LATE MORNING AND A BRIEF PERIOD OF MVFR
THIS AFTERNOON EVENING AS BOUNDARY LAYER HEATING MIXES OUT SOME
OF THE SURFACE MOISTURE...BEFORE ANOTHER ROUND OF IFR /TO POSSIBLY
LOWER/ RESTRICTIONS DEVELOPED OVERNIGHT TONIGHT. SOME INSTABILITY
INDICATED FOR THIS AFTERNOON SO HAVE INCLUDED VCSH AS MAIN AREA
OF PRECIPITATION WILL BE WELL OFF TO THE WEST. WINDS REMAIN OUT
OF THE SOUTH GENERALLY AROUND 5KT BUT CANNOT RULE OUT BRIEFLY
STRONGER WINDS.
AT KAVL...CIGS HAVE BEEN MVFR MOST OF THE NIGHT AND SHOULD BEGIN
TO LOWER IN THE NEXT COUPLE OF HOURS...HOVERING MAINLY LOW MVFR
THROUGH THE DAY. KAVL HAS THE BEST CHANCE OF SEEING TSRA TODAY AND
DEBATED ADDING VCTS OR AT LEAST PROB30 TSRA TO THE TAF. HOWEVER
GIVEN UNCERTAINTY IN MODEL TRENDS ENDED UP STAYING WITH VCSH BUT
WILL LIKELY HAVE TO MONITOR THROUGH THE DAY.
OUTLOOK...COULD SEE SOME MINOR IMPROVEMENT OVER THE WEEKEND AS THE
FRONT LIFTS NORTH...THOUGH SOUTHERLY UPSLOPE FLOW WILL PERSIST
WITH CONTINUED RESTRICTIONS EXPECTED. ANOTHER WET SYSTEM WILL
APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-12Z
KCLT HIGH 83% HIGH 81% MED 71% HIGH 84%
KGSP HIGH 87% HIGH 94% MED 67% HIGH 87%
KAVL MED 68% MED 74% MED 79% HIGH 82%
KHKY HIGH 81% MED 74% MED 79% HIGH 87%
KGMU MED 79% HIGH 87% LOW 56% MED 76%
KAND HIGH 81% HIGH 98% HIGH 84% MED 69%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR GAZ010-017-
018-026-028.
NC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ033-035-
048>053-058-059-062>065-501>510.
SC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ001>007-
010.
&&
$$
SYNOPSIS...SBK
NEAR TERM...JDL/TDP
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...TDP
CLIMATE...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1025 AM EST FRI DEC 25 2015
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS NEW ENGLAND...THE TENNESSEE VALLEY
AND INTO THE LOWER MISSISSIPPI VALLEY THIS MORNING. THIS FRONT
WILL STALL OVER THE MID ATLANTIC REGION TONIGHT. SUNDAY AND MONDAY
A SERIES OF STRONG LOW PRESSURE SYSTEMS WILL TRACK FROM THE
SOUTHERN PLAINS TO THE GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 942 AM EST FRIDAY...
ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 9 AM. WIDESPREAD
DENSE FOG HAS ENDED. VISIBILITIES ARE IMPROVING AND TREND WILL
CONTINUE THIS MORNING. AS WINDS INCREASE...THE FOG WILL ERODE OR
MIX OUT.
MODIFIED TEMPERATURES TOWARDS CURRENT OBS AND SHAPED TOWARDS THE
LAV FOR THIS MORNING INTO THIS AFTERNOON. HIGH TEMPERATURES THIS
AFTERNOON WILL UNSEASONABLY WARM WITH READINGS FROM THE LOWER 60S
IN THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. LEANED POPS
TOWARDS THE HRRR SOLUTION WHICH SEEMED TO CAPTURE THE LATEST WSR-
88D IMAGES AND TRENDS. PLAN TO HOLD WITH CURRENT FLOOD WATCH AND
WAIT TO EXAMINE 12Z MODEL RUN AND HOW CONVECTION DEVELOPS AND
UNFOLDS. INITIAL IMPRESSIONS THAT A EXPANSION OF THE FLOOD WATCH
MAY BE NEED LATER TODAY.
AS OF 630 AM EST FRIDAY...
HAVE ISSUED A DENSE FOG ADVISORY FROM THE ALLEGHANY HIGHLANDS
THROUGH THE ROANOKE AND NEW RIVER VALLEYS INTO NORTHWEST NORTH
CAROLINA.
TWO AREAS OF PRECIPITATION WILL CROSS THROUGH THE FORECAST AREA
TODAY AND TONIGHT. THE FIRST AREA WAS OVER THE SOUTHERN APPALACHIANS
AND WAS ADVANCING NORTHEAST AND WAS JUST ENTERING WATAUGA COUNTY
AT 4AM. THESE SHOWER WILL PASS THROUGH THE COUNTY WARNING AREA
MAINLY BEFORE NOON.
THE NEXT AREA OF PRECIPITATION WAS MOVING INTO WESTERN KENTUCKY AND
TENNESSEE. THIS PRECIPITATION WAS ASSOCIATED WITH A SHORT WAVE AND
LOW PRESSURE ALONG A COLD FRONT OVER THE LOWER MISSISSIPPI VALLEY.
AS THE LOW TRACKS NORTHEAST THE SHOWERS AND ISOLATED THUNDERSTORMS
WILL REACH THE CENTRAL APPALACHIANS THIS AFTERNOON AND EVENING.
MODELS SHOWED SOME DIFFERENCES IN THE LOCATION OF THE AXIS OF
HEAVIEST RAIN. STAYED CLOSE TO WPC FORECAST WITH THE HEAVIEST
RAINFALL EXPECTED NORTHWEST OF A LYNCHBURG TO MARION LINE. HAVE
INCREASED THE PROBABILITY OF PRECIPITATION IN THE NORTHWEST COUNTY
WARNING AREA FOR TODAY AND TONIGHT AND TRIMMED BACK THE PROBABILITY
IN THE SOUTHEAST.
THE SURFACE FRONT WILL BE CLOSE TO...IN NOT JUST INTO...THE NORTHERN
COUNTY WARNING AREA BY TONIGHT. ECMWF/GFS AND NAM ALL BRING THE
FRONT SOUTH OF LYNCHBURG BY EARLY SATURDAY MORNING. THIS WILL
KEEP A MAJORITY OF THE FORECAST AREA IN THE VERY WARM AND MOIST
AIRMASS TODAY AND TONIGHT. FOOTHILLS AND PIEDMONT OF SOUTHERN
VIRGINIA AND NORTHWEST NORTH CAROLINA WERE STILL IN THE UPPER 60S
AT 4AM SO INCREASED MAXIMUM TEMPERATURES INTO THE MID 70S IN THERE
LOCATIONS. OTHERWISE STAYED CLOSE TO GUIDANCE FOR MAXIMUM AND
MINIMUM TEMPERATURES.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 400 AM EST FRIDAY...
OUR VERY WARM AND UNSETTLED PATTERN WILL CONTINUE THROUGH THE WEEKEND
BEFORE WE START TO SEE ANY SIGNIFICANT CHANGES STARTING MONDAY. THE
UPPER PATTERN WILL CONTINUE TO FEATURE AN EASTERN RIDGE AS A CLOSED LOW
DEVELOPS OVER TEXAS AND THEN EJECTS INTO THE OHIO VALLEY. THIS WILL
PUSH THE OLD FRONTAL BOUNDARY...WHICH HAS BEEN WAVERING AROUND THE
REGION FOR THE LAST SEVERAL DAYS...BACK TO THE NORTH AND KEEP THE BEST
CHANCES FOR PRECIPITATION MAINLY NORTH OF ROUTE 460. SUNDAY WILL SEE
SOME LINGERING LIGHT PRECIPITATION MAINLY ALONG THE BLUE RIDGE BUT AS
THE AFOREMENTIONED CLOSED UPPER LOW STARTS TO EJECT...IT WILL DRIVE A
DEVELOPING SURFACE LOW UP THE MISSISSIPPI VALLEY AND START TO SPREAD
PRECIPITATION INTO THE REGION FROM THE WEST. MEANWHILE A STRONG SURFACE
HIGH WILL MOVE THROUGH SOUTHERN CANADA AND WEDGE DOWN THE EASTERN
SEABOARD. THIS WILL PUSH A BACKDOOR COLD FRONT INTO THE REGION SUNDAY
NIGHT WITH A COLD WEDGE SETTING UP FOR MONDAY WITH A SUBSTANTIAL COOL
DOWN EXPECTED. THE COMBINATION OF A COLD WEDGE OVER THE AREA AND THE
LOW PRESSURE SYSTEM MOVING UP THE MISSISSIPPI VALLEY WILL GET NEXT WEEK
OFF TO A WET START. THE LOW LEVEL WIND FIELD WILL ALSO BE STRENGTHENING
ON MONDAY AND SOME RIDGE TOPS OUTSIDE OF THE WEDGE ALONG THE FAR
WESTERN SLOPES OF THE APPALACHIANS MAY BE LOOKING AT WIND GUSTS OVER 40
MPH.
HIGH TEMPERATURES SATURDAY AND SUNDAY WILL REMAIN NEAR RECORD LEVELS
WITH LOW/MID 70S EAST OF THE BLUE RIDGE AND MID 60S/AROUND 70 TO THE
WEST. HOWEVER TEMPERATURES ON MONDAY IN THE COOL WEDGE WILL ONLY BE IN
THE MID/UPPER 50S TO THE EAST WITH UPPER 40S/LOWER 50S WEST...AND
MONDAY NIGHT LOW TEMPERATURES WILL START TO APPROACH THE FREEZING MARK
FOR THE ALLEGHANY HIGHLANDS. THESE LOWER TEMPERATURES WILL FEEL
SUBSTANTIALLY COOLER BUT ARE STILL WELL ABOVE NORMAL FOR LATE DECEMBER.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 245 PM EST WEDNESDAY...
A SURFACE FRONTAL BOUNDARY DRAPED FROM THE OHIO VALLEY TO THE
SOUTHERN PLAINS WILL MEANDER CLOSE TO THE REGION KEEPING...WITH
THE GREATEST THREAT FOR SHOWERS TUESDAY AS THE FRONT OCCLUDES AND
SLOWLY PUSHES THROUGH OUR REGION AND EVENTUALLY STALLS TO OUR
SOUTHEAST ON WEDNESDAY.
TEMPS BACK OFF TO +5-10C TUESDAY THROUGH THURSDAY BEFORE THE
COLDER AIR ARRIVES FRIDAY.
MODELS TEND TO AGREE THAT THE END OF THE WEEK WILL FEATURE A PUSH
OF MUCH COLDER AND DRIER AIR INTO THE REGION AS A SHORTWAVE DIGS
IN. DIFFERENCES EXIST AS TO HOW DEEP THAT PUSH OF COLDER AIR WILL
BE AND HOW MUCH IF ANY MOISTURE WILL BE AVAILABLE FOR ANY
POTENTIAL UPSLOPE PRECIP/CLOUDS LATE IN THE WEEK.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AS OF 630 AM EST THURSDAY...
STARTING WITH LIFR CONDITIONS AT KROA/KLYH AND KBCB THIS MORNING.
HAVE A BRIEF PERIOD OF VFR FOR THE AREA TAFS THIS AFTERNOON.
CONFIDENCE IS HIGHER AT KDAN THAN ANY OTHER THE OTHER SITES.
LEADING EDGE OF A LARGE AREA OF SHOWERS OVER THE SOUTHERN
APPALACHIANS WILL BE PASSING CLOSE TO KDAN AT THE BEGINNING OF THE
TAF FORECAST PERIOD. MODELS HAVE THE MAJORITY OF THESE SHOWERS
MOVING THROUGH THE AREA THIS MORNING. MEDIUM CONFIDENCE OF MVFR
CEILINGS AND VISIBILITIES WITH THIS PRECIPITATION.
SHOWERS AND A FEW THUNDERSTORMS WILL MOVE INTO THE AREA FROM THE
TENNESSEE VALLEY THIS AFTERNOON. CONFIDENCE WAS TOO LOW TO INCLUDE
THUNDER IN THE TAFS AT THIS TIME BUT KLWB AND KBLF WOULD BE THE
SITES WITH THE BEST CHANCE OF THUNDER.
AFTER SUNSET CONDITIONS WILL DETERIORATE BACK TO LIFR CEILINGS.
LOWER CONFIDENCE ABOUT HOW WIDESPREAD DENSE FOG WILL BE.
CONFIDENCE IS LOW IN THIS TERMINAL FORECAST...BUT HIGH ENOUGH TO
KEEP MOST MVFR OR WORSE.
.EXTENDED AVIATION DISCUSSION...
THE CHANCE OF SHOWERS AND SUB-VFR CONDITIONS WILL CONTINUE INTO
THE WEEKEND...BUT OVERALL LESS LIKELY TO PERSIST IN THE IFR OR
WORSE VALUES AS ATMOSPHERE WILL BE A LITTLE BETTER MIXED AND
FREQUENCY OF SHOWERS MUCH LESS WITH NO KEY FEATURES TO HELP LIFT
THE MOIST ATMOSPHERE.
BEYOND THIS WEEKEND...MODELS CONTINUE TO VARY BUT SHOWING BETTER
THREAT OF SHOWERS AGAIN BY LATE MONDAY INTO TUESDAY WITH VFR TO
IFR AT TIMES.
&&
.HYDROLOGY...
AS OF 1024 AM EST FRIDAY...
WILL MAINTAIN FLASH FLOOD WATCH FOR THE REST OF THE DAY. HIGHEST
THREAT WILL BE IN THE NORTHWEST HALF OF THE FORECAST AREA. THREE
HOUR FLASH FLOOD GUIDANCE IN THIS REGION WAS GENERALLY LESS THAN 1.5
INCHES. PRECIPITABLE WATER VALUES REMAIN UNSEASONABLY HIGH WITH A
DEEP LAYER OF THE ATMOSPHERE SUPPORTING EFFICIENT WARM RAIN
PROCESSES. SO SIMILAR TO THURSDAY...RAINFALL RATES MAY REACH ONE TO
TWO INCHES PER HOUR.
FOR MAINSTEM RIVERS... FLOOD WARNINGS REMAIN IN EFFECT ALONG THE
DAN RIVER THROUGH SOUTH BOSTON. AS OF 1016 AM...WENTWORTH
HAS FALLEN BELOW FLOOD STAGE AND WILL CONTINUE TO SLOWLY FALL.
ON THE ROANOKE RIVER A FLOOD WARNING CONTINUES FOR RANDOLPH. AT
RANDOLPH...THE RIVER WAS EXPERIENCING MODERATE FLOODING AS WAS
STILL RISING AND SHOULD CREST THIS EVENING.
CHARLOTTE AND HALIFAX COUNTY OFFICIALS REPORTED SEVERAL ROADS
REMAINED CLOSED DUE TO FLOODING.
&&
.CLIMATE...
AS OF 430 AM EST THURSDAY...
WITH THE CONTINUING VERY WARM AIRMASS IN PLACE FOR THE NEXT
SEVERAL DAYS... MANY DAILY MAX TEMPERATURE RECORDS AS WELL AS HIGH
MIN TEMPERATURE RECORDS ARE LIKELY TO BE SET. FOR REFERENCE...HERE
ARE RECORDS FOR OUR CLIMATE STATIONS FOR THE NEXT SEVERAL DAYS.
FRIDAY 12/25/2015
SITE MAXT YEAR HIMIN YEAR
KBLF 64 1982 55 1982
KDAN 76 1955 48 1988
KLYH 72 1982 57 1964
KROA 68 1982 54 1964
KRNK 68 1964 41 1972
SATURDAY 12/26/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 62 1987 -3 1983 16 1977 55 1982
KDAN 75 1982 2 1983 18 1983 57 1964
KLYH 72 1922 1 1983 22 1914 58 1964
KROA 70 1964 3 1980 23 1985 56 1982
KRNK 64 1982 -8 1985 9 1983 50 1982
SUNDAY 12/27/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 69 2008 9 1977 20 2010 52 1982
KDAN 77 1982 6 1983 27 1985 54 1964
KLYH 71 1971 0 1914 21 1925 50 1940
KROA 69 1984 -3 1914 25 1935 52 1940
KRNK 67 2008 -6 1985 20 1985 52 1964
MONDAY 12/28/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 67 1984 4 1977 20 1995 53 1984
KDAN 72 1971 13 1966 28 1950 54 2008
KLYH 76 1984 6 1977 26 1950 51 1959
KROA 75 1984 4 1925 25 1925 51 1984
KRNK 66 1984 6 1977 28 1995 42 1959
&&
.EQUIPMENT...
AS OF 920 PM EST THURSDAY...
THE DANVILLE OBSERVATION APPEARS TO BE WORKING CONSISTENTLY
AGAIN...BUT WILL NEED TO BE MONITORED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR VAZ007-
009>020-022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR WVZ042>044-
507-508.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...MBS
LONG TERM...CF/MBS
AVIATION...AMS/WP
HYDROLOGY...AMS/KK
CLIMATE...AMS/RCS
EQUIPMENT...RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
943 AM EST FRI DEC 25 2015
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS NEW ENGLAND...THE TENNESSEE VALLEY
AND INTO THE LOWER MISSISSIPPI VALLEY THIS MORNING. THIS FRONT
WILL STALL OVER THE MID ATLANTIC REGION TONIGHT. SUNDAY AND MONDAY
A SERIES OF STRONG LOW PRESSURE SYSTEMS WILL TRACK FROM THE
SOUTHERN PLAINS TO THE GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 942 AM EST FRIDAY...
ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 9 AM. WIDESPREAD
DENSE FOG HAS ENDED. VISIBILITIES ARE IMPROVING AND TREND WILL
CONTINUE THIS MORNING. AS WINDS INCREASE...THE FOG WILL ERODE OR
MIX OUT.
MODIFIED TEMPERATURES TOWARDS CURRENT OBS AND SHAPED TOWARDS THE
LAV FOR THIS MORNING INTO THIS AFTERNOON. HIGH TEMPERATURES THIS
AFTERNOON WILL UNSEASONABLY WARM WITH READINGS FROM THE LOWER 60S
IN THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. LEANED POPS
TOWARDS THE HRRR SOLUTION WHICH SEEMED TO CAPTURE THE LATEST WSR-
88D IMAGES AND TRENDS. PLAN TO HOLD WITH CURRENT FLOOD WATCH AND
WAIT TO EXAMINE 12Z MODEL RUN AND HOW CONVECTION DEVELOPS AND
UNFOLDS. INITIAL IMPRESSIONS THAT A EXPANSION OF THE FLOOD WATCH
MAY BE NEED LATER TODAY.
AS OF 630 AM EST FRIDAY...
HAVE ISSUED A DENSE FOG ADVISORY FROM THE ALLEGHANY HIGHLANDS
THROUGH THE ROANOKE AND NEW RIVER VALLEYS INTO NORTHWEST NORTH
CAROLINA.
TWO AREAS OF PRECIPITATION WILL CROSS THROUGH THE FORECAST AREA
TODAY AND TONIGHT. THE FIRST AREA WAS OVER THE SOUTHERN APPALACHIANS
AND WAS ADVANCING NORTHEAST AND WAS JUST ENTERING WATAUGA COUNTY
AT 4AM. THESE SHOWER WILL PASS THROUGH THE COUNTY WARNING AREA
MAINLY BEFORE NOON.
THE NEXT AREA OF PRECIPITATION WAS MOVING INTO WESTERN KENTUCKY AND
TENNESSEE. THIS PRECIPITATION WAS ASSOCIATED WITH A SHORT WAVE AND
LOW PRESSURE ALONG A COLD FRONT OVER THE LOWER MISSISSIPPI VALLEY.
AS THE LOW TRACKS NORTHEAST THE SHOWERS AND ISOLATED THUNDERSTORMS
WILL REACH THE CENTRAL APPALACHIANS THIS AFTERNOON AND EVENING.
MODELS SHOWED SOME DIFFERENCES IN THE LOCATION OF THE AXIS OF
HEAVIEST RAIN. STAYED CLOSE TO WPC FORECAST WITH THE HEAVIEST
RAINFALL EXPECTED NORTHWEST OF A LYNCHBURG TO MARION LINE. HAVE
INCREASED THE PROBABILITY OF PRECIPITATION IN THE NORTHWEST COUNTY
WARNING AREA FOR TODAY AND TONIGHT AND TRIMMED BACK THE PROBABILITY
IN THE SOUTHEAST.
THE SURFACE FRONT WILL BE CLOSE TO...IN NOT JUST INTO...THE NORTHERN
COUNTY WARNING AREA BY TONIGHT. ECMWF/GFS AND NAM ALL BRING THE
FRONT SOUTH OF LYNCHBURG BY EARLY SATURDAY MORNING. THIS WILL
KEEP A MAJORITY OF THE FORECAST AREA IN THE VERY WARM AND MOIST
AIRMASS TODAY AND TONIGHT. FOOTHILLS AND PIEDMONT OF SOUTHERN
VIRGINIA AND NORTHWEST NORTH CAROLINA WERE STILL IN THE UPPER 60S
AT 4AM SO INCREASED MAXIMUM TEMPERATURES INTO THE MID 70S IN THERE
LOCATIONS. OTHERWISE STAYED CLOSE TO GUIDANCE FOR MAXIMUM AND
MINIMUM TEMPERATURES.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 400 AM EST FRIDAY...
OUR VERY WARM AND UNSETTLED PATTERN WILL CONTINUE THROUGH THE WEEKEND
BEFORE WE START TO SEE ANY SIGNIFICANT CHANGES STARTING MONDAY. THE
UPPER PATTERN WILL CONTINUE TO FEATURE AN EASTERN RIDGE AS A CLOSED LOW
DEVELOPS OVER TEXAS AND THEN EJECTS INTO THE OHIO VALLEY. THIS WILL
PUSH THE OLD FRONTAL BOUNDARY...WHICH HAS BEEN WAVERING AROUND THE
REGION FOR THE LAST SEVERAL DAYS...BACK TO THE NORTH AND KEEP THE BEST
CHANCES FOR PRECIPITATION MAINLY NORTH OF ROUTE 460. SUNDAY WILL SEE
SOME LINGERING LIGHT PRECIPITATION MAINLY ALONG THE BLUE RIDGE BUT AS
THE AFOREMENTIONED CLOSED UPPER LOW STARTS TO EJECT...IT WILL DRIVE A
DEVELOPING SURFACE LOW UP THE MISSISSIPPI VALLEY AND START TO SPREAD
PRECIPITATION INTO THE REGION FROM THE WEST. MEANWHILE A STRONG SURFACE
HIGH WILL MOVE THROUGH SOUTHERN CANADA AND WEDGE DOWN THE EASTERN
SEABOARD. THIS WILL PUSH A BACKDOOR COLD FRONT INTO THE REGION SUNDAY
NIGHT WITH A COLD WEDGE SETTING UP FOR MONDAY WITH A SUBSTANTIAL COOL
DOWN EXPECTED. THE COMBINATION OF A COLD WEDGE OVER THE AREA AND THE
LOW PRESSURE SYSTEM MOVING UP THE MISSISSIPPI VALLEY WILL GET NEXT WEEK
OFF TO A WET START. THE LOW LEVEL WIND FIELD WILL ALSO BE STRENGTHENING
ON MONDAY AND SOME RIDGE TOPS OUTSIDE OF THE WEDGE ALONG THE FAR
WESTERN SLOPES OF THE APPALACHIANS MAY BE LOOKING AT WIND GUSTS OVER 40
MPH.
HIGH TEMPERATURES SATURDAY AND SUNDAY WILL REMAIN NEAR RECORD LEVELS
WITH LOW/MID 70S EAST OF THE BLUE RIDGE AND MID 60S/AROUND 70 TO THE
WEST. HOWEVER TEMPERATURES ON MONDAY IN THE COOL WEDGE WILL ONLY BE IN
THE MID/UPPER 50S TO THE EAST WITH UPPER 40S/LOWER 50S WEST...AND
MONDAY NIGHT LOW TEMPERATURES WILL START TO APPROACH THE FREEZING MARK
FOR THE ALLEGHANY HIGHLANDS. THESE LOWER TEMPERATURES WILL FEEL
SUBSTANTIALLY COOLER BUT ARE STILL WELL ABOVE NORMAL FOR LATE DECEMBER.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 245 PM EST WEDNESDAY...
A SURFACE FRONTAL BOUNDARY DRAPED FROM THE OHIO VALLEY TO THE
SOUTHERN PLAINS WILL MEANDER CLOSE TO THE REGION KEEPING...WITH
THE GREATEST THREAT FOR SHOWERS TUESDAY AS THE FRONT OCCLUDES AND
SLOWLY PUSHES THROUGH OUR REGION AND EVENTUALLY STALLS TO OUR
SOUTHEAST ON WEDNESDAY.
TEMPS BACK OFF TO +5-10C TUESDAY THROUGH THURSDAY BEFORE THE
COLDER AIR ARRIVES FRIDAY.
MODELS TEND TO AGREE THAT THE END OF THE WEEK WILL FEATURE A PUSH
OF MUCH COLDER AND DRIER AIR INTO THE REGION AS A SHORTWAVE DIGS
IN. DIFFERENCES EXIST AS TO HOW DEEP THAT PUSH OF COLDER AIR WILL
BE AND HOW MUCH IF ANY MOISTURE WILL BE AVAILABLE FOR ANY
POTENTIAL UPSLOPE PRECIP/CLOUDS LATE IN THE WEEK.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
AS OF 630 AM EST THURSDAY...
STARTING WITH LIFR CONDITIONS AT KROA/KLYH AND KBCB THIS MORNING.
HAVE A BRIEF PERIOD OF VFR FOR THE AREA TAFS THIS AFTERNOON.
CONFIDENCE IS HIGHER AT KDAN THAN ANY OTHER THE OTHER SITES.
LEADING EDGE OF A LARGE AREA OF SHOWERS OVER THE SOUTHERN
APPALACHIANS WILL BE PASSING CLOSE TO KDAN AT THE BEGINNING OF THE
TAF FORECAST PERIOD. MODELS HAVE THE MAJORITY OF THESE SHOWERS
MOVING THROUGH THE AREA THIS MORNING. MEDIUM CONFIDENCE OF MVFR
CEILINGS AND VISIBILITIES WITH THIS PRECIPITATION.
SHOWERS AND A FEW THUNDERSTORMS WILL MOVE INTO THE AREA FROM THE
TENNESSEE VALLEY THIS AFTERNOON. CONFIDENCE WAS TOO LOW TO INCLUDE
THUNDER IN THE TAFS AT THIS TIME BUT KLWB AND KBLF WOULD BE THE
SITES WITH THE BEST CHANCE OF THUNDER.
AFTER SUNSET CONDITIONS WILL DETERIORATE BACK TO LIFR CEILINGS.
LOWER CONFIDENCE ABOUT HOW WIDESPREAD DENSE FOG WILL BE.
CONFIDENCE IS LOW IN THIS TERMINAL FORECAST...BUT HIGH ENOUGH TO
KEEP MOST MVFR OR WORSE.
.EXTENDED AVIATION DISCUSSION...
THE CHANCE OF SHOWERS AND SUB-VFR CONDITIONS WILL CONTINUE INTO
THE WEEKEND...BUT OVERALL LESS LIKELY TO PERSIST IN THE IFR OR
WORSE VALUES AS ATMOSPHERE WILL BE A LITTLE BETTER MIXED AND
FREQUENCY OF SHOWERS MUCH LESS WITH NO KEY FEATURES TO HELP LIFT
THE MOIST ATMOSPHERE.
BEYOND THIS WEEKEND...MODELS CONTINUE TO VARY BUT SHOWING BETTER
THREAT OF SHOWERS AGAIN BY LATE MONDAY INTO TUESDAY WITH VFR TO
IFR AT TIMES.
&&
.HYDROLOGY...
AS OF 430 AM EST FRIDAY...
WILL MAINTAIN FLASH FLOOD WATCH FOR THE REST OF THE DAY. HIGHEST
THREAT WILL BE IN THE NORTHWEST HALF OF THE FORECAST AREA. THREE
HOUR FLASH FLOOD GUIDANCE IN THIS REGION WAS GENERALLY LESS THAN 1.5
INCHES. PRECIPITABLE WATER VALUES REMAIN UNSEASONABLY HIGH WITH A
DEEP LAYER OF THE ATMOSPHERE SUPPORTING EFFICIENT WARM RAIN
PROCESSES. SO SIMILAR TO THURSDAY...RAINFALL RATES MAY REACH ONE TO
TWO INCHES PER HOUR.
FOR MAINSTEM RIVERS... FLOOD WARNINGS REMAIN IN EFFECT FOR THE DAN
RIVER FROM PINE HALL THROUGH SOUTH BOSTON. AS OF 4AM...PINE HALL HAS
RECEDED AND THE CREST WAS NEAR WENTWORTH.
ON THE ROANOKE RIVER A FLOOD WARNING CONTINUES FOR RANDOLPH. AT
RANDOLPH THE RIVER WAS EXPERIENCING MODERATE FLOODING AS WAS STILL
RISING.
CHARLOTTE AND HALIFAX COUNTY OFFICIALS REPORTED SEVERAL ROADS
REMAINED CLOSED DUE TO FLOODING.
&&
.CLIMATE...
AS OF 430 AM EST THURSDAY...
WITH THE CONTINUING VERY WARM AIRMASS IN PLACE FOR THE NEXT
SEVERAL DAYS... MANY DAILY MAX TEMPERATURE RECORDS AS WELL AS HIGH
MIN TEMPERATURE RECORDS ARE LIKELY TO BE SET. FOR REFERENCE...HERE
ARE RECORDS FOR OUR CLIMATE STATIONS FOR THE NEXT SEVERAL DAYS.
FRIDAY 12/25/2015
SITE MAXT YEAR HIMIN YEAR
KBLF 64 1982 55 1982
KDAN 76 1955 48 1988
KLYH 72 1982 57 1964
KROA 68 1982 54 1964
KRNK 68 1964 41 1972
SATURDAY 12/26/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 62 1987 -3 1983 16 1977 55 1982
KDAN 75 1982 2 1983 18 1983 57 1964
KLYH 72 1922 1 1983 22 1914 58 1964
KROA 70 1964 3 1980 23 1985 56 1982
KRNK 64 1982 -8 1985 9 1983 50 1982
SUNDAY 12/27/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 69 2008 9 1977 20 2010 52 1982
KDAN 77 1982 6 1983 27 1985 54 1964
KLYH 71 1971 0 1914 21 1925 50 1940
KROA 69 1984 -3 1914 25 1935 52 1940
KRNK 67 2008 -6 1985 20 1985 52 1964
MONDAY 12/28/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 67 1984 4 1977 20 1995 53 1984
KDAN 72 1971 13 1966 28 1950 54 2008
KLYH 76 1984 6 1977 26 1950 51 1959
KROA 75 1984 4 1925 25 1925 51 1984
KRNK 66 1984 6 1977 28 1995 42 1959
&&
.EQUIPMENT...
AS OF 920 PM EST THURSDAY...
THE DANVILLE OBSERVATION APPEARS TO BE WORKING CONSISTENTLY
AGAIN...BUT WILL NEED TO BE MONITORED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR VAZ007-
009>020-022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR WVZ042>044-
507-508.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/KK
SHORT TERM...MBS
LONG TERM...CF/MBS
AVIATION...AMS/WP
HYDROLOGY...AMS
CLIMATE...AMS/RCS
EQUIPMENT...RCS
AREA FORECAST DISCUSSION
NWS PUEBLO CO
121 PM MST FRI DEC 25 2015
.UPDATE...
ISSUED AT 117 PM MST FRI DEC 25 2015
IN THE PROCESS OF ISSUING A SHORT HIGH WIND WARNING FOR THE
SOUTHERN I25 CORRIDOR...AS WINDS HAVE GUSTED OVER 50 KTS AT KTAD
AND HRRR SUGGESTS A FEW MORE HOURS OF HIGH WINDS LIKELY.
UPDATE ISSUED AT 1028 AM MST FRI DEC 25 2015
CURRENT BLIZZARD WARNING OVER THE SAN JUANS LOOKS GOOD...AS CDOT
WEB CAMS INDICATE NEAR ZERO VISIBILITY WITH EXTENSIVE BLOWING AND
DRIFTING SNOW AT BOTH WOLF CREEK AND CUMBRES PASSES. STILL APPEARS
WE`LL HAVE SEVERAL MORE HOURS OF HEAVIER SNOW ALONG THE DIVIDE
BEFORE PRECIP INTENSITY BEGINS TO WANE LATE THIS AFTERNOON.
UPDATE ISSUED AT 745 AM MST FRI DEC 25 2015
BASED ON LATEST OBSERVATIONS AND WEB CAMS ACROSS THE EASTERN SAN
JUANS...UPGRADED THE WINTER STORM WARNING TO A BLIZZARD WARNING
THROUGH THIS EVENING. HIGH RES MODELS SHOW HEAVIEST SNOW IMPACTING
THE REGION THIS MORNING THROUGH MID AFTERNOON...WITH A GRADUAL
DECREASE IN SNOW AND WIND THIS EVENING. SUSPECT THAT THE BLIZZARD
WARNING MAY BE ABLE TO BE DOWNGRADED EARLY THIS EVENING...BUT LET
LATER SHIFTS MONITOR AND REVISE AS NECESSARY. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 435 AM MST FRI DEC 25 2015
...WINDY WITH HEAVY SNOW ALONG THE CONTINENTAL DIVIDE TODAY...
SHORTWAVE ACROSS SOUTHERN NV/WRN UT WILL EJECT TO THE NORTHEAST
ACROSS CO TODAY AS JET ENERGY DIGS DOWN THE WESTERN SIDE OF THE MEAN
TROF...CARVING OUT A CLOSED LOW OVER AZ BY TONIGHT. MOISTURE
ALREADY ON THE INCREASE ACROSS WESTERN CO...WITH GJX RADAR SHOWING
INCREASING ECHOES EARLY THIS MORNING. ALL MODELS IN GOOD AGREEMENT
WITH HEAVY SNOW SPREADING INTO THE CONTDVD BY EARLY MORNING...AND
CONTINUING THROUGH THE AFTERNOON...SPREADING EASTWARD WITH TIME...AS
THE SYSTEM MOVES ACROSS. HEAVIEST ACCUMULATIONS WILL OCCUR ACROSS
THE EASTERN SAN JUAN MOUNTAINS WHERE SOUTHWEST FLOW PROVIDES THE
MOST FAVORABLE OROGRAPHIC LIFT. A FOOT OR BETTER WILL FALL OVER THE
REGION BY THE END OF TODAY AND CURRENT WARNING STILL LOOKS ON
TARGET. STRONG WINDS WILL ALSO BE A CONCERN TODAY WITH HIGH RES
MODELS SHOWING WIND GUSTS IN EXCESS OF 50 MPH AT TIMES THIS
AFTERNOON ACROSS THE HIGHER ELEVATIONS AND EASTERN SLOPES. THIS
RAISES THE POSSIBILITY OF NEEDING A BLIZZARD WARNING FOR ZONE
68...BUT NOT SURE HOW WIDESPREAD THESE CONDITIONS WILL BE. WILL LET
THE CURRENT WINTER STORM WARNING RIDE FOR NOW AND MONITOR WEB CAMS
FOR POTENTIAL UPGRADE. REMAINDER OF THE CONTDVD WILL SEE SNOW
AMOUNTS IN THE 4 TO 8 INCH RANGE...WITH LOCALLY UP TO A FOOT
POSSIBLE FOR THE HIGHER PEAKS OF THE SAWATCH RANGE. SNOW WILL
SPREAD EASTWARD INTO THE SOUTHEAST MOUNTAINS BY AFTERNOON...WITH
BANDS OF MODERATE TO HEAVY SNOW POSSIBLE. THESE SHOULD BE MOVING
FAIRLY QUICKLY THOUGH WHICH SHOULD LIMIT ACCUMULATIONS TO AN INCH OR
TWO FOR LOCATIONS IN AND NEAR THE MOUNTAINS. EXCEPTION WILL BE THE
CREST OF THE NORTHERN SANGRE WHERE 4-8 INCHES WILL BE POSSIBLE. SNOW
SHOWERS WILL BE FIGHTING A STRONG DOWNSLOPE COMPONENT AS THEY COME
OFF THE EASTERN MOUNTAINS TODAY...WHICH SHOULD LIMIT POPS TO
ISOLATED FOR THE MOST PART. OF GREATER CONCERN FOR THE SOUTHEAST
PLAINS AND SAN LUIS VALLEY WILL BE THE POTENTIAL FOR STRONG GUSTY
SOUTHWEST WINDS THIS AFTERNOON. GUSTS TO 40 TO AROUND 55 MPH WILL BE
POSSIBLE...PARTICULARLY TO THE SOUTH OF HIGHWAY 50. ANY SHOWERS
WHICH MOVE OFF THE MOUNTAINS COULD NUDGE WIND GUSTS A LITTLE HIGHER
THOUGH THINK THIS WILL BE SPOTTY AND CONFINED TO LOCATIONS CLOSER TO
THE MOUNTAINS.
SNOW WANES ACROSS THE MOUNTAINS TONIGHT...BUT HAVE OPTED TO EXTEND
ADVISORIES ALONG THE CONTDVD UNTIL 06Z AS WINDS MAY STILL BE CAUSING
SOME BLOWING CONCERNS DURING THE EARLY EVENING. MEANWHILE...COLD
FRONT WILL DROP THROUGH THE PLAINS...WHICH WILL BRING A BETTER
CHANCE OF SNOW TO THE PALMER DIVIDE...AND STRATUS AND LIGHT SNOW
SHOWERS TO THE NORTHERN SLOPES OF THE RATON BY EARLY MORNING. GIVEN
THE INITIAL SHALLOW PUSH OF THE FRONT INTO SOUTHERN SECTIONS OF THE
AREA...IT MAY TAKE SOME TIME FOR SNOW TO DEVELOP ALONG THE NORTHERN
SLOPES OF THE RATON MESA...AND HAVE DELAYED POPS A BIT. -KT
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 435 AM MST FRI DEC 25 2015
OVERALL...MAJORITY OF COMPUTER SIMULATIONS CONTINUE SOUTHERN
TRACK OF INCOMING STORM DURING THE LONGER TERM WITH PRIMARY
METEOROLOGICAL CONCERNS BEING POPS...TEMPERATURES AND WINDS.
RECENT LONGER TERM COMPUTER SIMULATIONS...FORECAST MODEL
SOUNDINGS AND PV ANALYSIS INDICATE THAT VIGOROUS CLOSED UPPER LOW
CENTERED NEAR FLAGSTAFF ARIZONA AT 12Z SATURDAY SHIFTS TO EAST OF
EL PASO TEXAS BY 12Z SUNDAY AND THEN MOVES INTO FAR NORTHEASTERN
TEXAS BY 12Z MONDAY BEFORE MAKING ITS WAY INTO THE UPPER MIDWEST
BY 12Z TUESDAY.
AT THIS TIME...IT APPEARS THAT SOUTHERN LOCATIONS WILL HAVE THE
HIGHEST PROBABILITY OF RECEIVING MEASURABLE PRECIPITATION IN
COMBINATION WITH GUSTY WINDS WITH THIS SYSTEM. CONTEMPLATED
ISSUING A WINTER STORM WATCH...ESPECIALLY OVER PORTIONS OF
COSTILLA...LAS ANIMAS AND BACA COUNTIES...HOWEVER REFRAINED AS
MAJORITY OF POTENTIAL PRECIPITATION OCCURS IN 5TH AND 6TH
PERIODS(SUNDAY INTO SUNDAY NIGHT)...AND SOME RECENT COMPUTER
SIMULATIONS ARE FAVORING A MORE SOUTHERN TREND IN RESPECT TO QPF
TOTALS. AS ALWAYS...WFO PUEBLO WILL MONITOR CLOSELY AND ISSUE
HIGHLIGHTS IF NEEDED(ESPECIALLY IF STORM TRACK SHIFTS SLIGHTLY
NORTH).
THEN NEXT GENERALLY WEAKER AND DRIER SYSTEMS ARE PROJECTED TO
IMPACT THE FORECAST DISTRICT FROM LATER TUESDAY INTO THURSDAY
NIGHT...ALTHOUGH AT THIS TIME...IT APPEARS THAT PRECIPITATION
AMOUNTS WILL REMAIN ON THE LIGHTER SIDE.
STRONGEST GRADIENT WINDS DURING THE LONGER TERM ARE EXPECTED
FROM LATER SATURDAY INTO SUNDAY NIGHT(PRIMARILY FAVORING EASTERN
SECTIONS). FINALLY...BELOW SEASONAL LATE DECEMBER TEMPERATURES
ARE ANTICIPATED DURING THE LONGER TERM WITH COOLEST TEMPERATURES
PROJECTED THIS WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1028 AM MST FRI DEC 25 2015
WIDESPREAD SN/BLSN WILL CONTINUE OVER THE CONTDVD AND HIGHER
PEAKS OF THE SANGRES AND PIKES PEAK TODAY...WITH IFR TO LIFR
CONDITIONS AND MTN OBSCURATIONS. SOME IMPROVEMENT IS THEN EXPECTED
OVERNIGHT AS SNOWFALL AND WIND DIMINISH. FOR THE TAF
SITES...GUSTY SOUTH TO SOUTHWEST WINDS WILL DEVELOP THIS
AFTERNOON...WITH GUSTS TO 45 KTS POSSIBLE AT KALS...AND 35 KTS AT KCOS
AND KPUB THROUGH 01Z. PASSING SHOWERS COULD BRING SOME BRIEF VFR
TO LOCALIZED MVFR CIGS TO KALS AND KCOS THIS AFTERNOON...BUT
STRONG DOWNSLOPE SHOULD KEEP PREVAILING CONDITIONS VFR. COLD FRONT
DROPS THROUGH THE PLAINS AFTER 06Z...WITH GUSTY NORTH WINDS TO 25
TO 30 KTS. CIGS WILL DROP INTO THE MVFR TO IFR CATEGORY OVER THE
PALMER DIVIDE AND RATON RIDGE TOWARDS MORNING...WHILE KPUB AND
KALS STAY VFR.
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR COZ073.
HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR COZ087-088.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR
COZ058>061-063-064-066-067.
BLIZZARD WARNING UNTIL 11 PM MST THIS EVENING FOR COZ068.
&&
$$
UPDATE...PETERSEN
AVIATION...PETERSEN
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
554 PM EST FRI DEC 25 2015
.SYNOPSIS...
HIGH PRESSURE RIDGING INTO THE FORECAST AREA FROM THE ATLANTIC
WILL MAINTAIN UNSEASONABLE WARM WEATHER IN THE FORECAST AREA
THROUGH THE WEEKEND. AN APPROACHING COLD FRONT WILL MOVE INTO THE
FORECAST AREA MONDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
A LINE OF SHOWERS HAS DEVELOPED IN THE SOUTH CAROLINA PIEDMONT AND
WAS PROPAGATING TO THE EAST/NORTHEAST THIS AFTERNOON. AIR MASS IN
THE NORTHERN MIDLANDS IS WEAKLY UNSTABLE. LATEST HRRR MODEL
SUGGESTS CONVECTION MAY MOVE INTO THE MIDLANDS. RAISED POPS NORTH
AND WEST OF CAE. ALTHOUGH NO LIGHTNING AT THE
MOMENT...THUNDERSTORMS POSSIBLE THROUGH MID EVENING.
THE PRESSURE RIDGE IN THE ATLANTIC WILL CIRCULATE WARM AIR INTO
THE FORECAST AREA THROUGH TONIGHT. DEEP MOISTURE ASSOCIATED WITH A
FRONT WILL REMAIN NORTH OF THE AREA. SHALLOW LOW-LEVEL MOISTURE
WILL REMAIN HERE. THE MOISTURE COMBINED WITH NOCTURNAL COOLING
SHOULD RESULT IN WIDESPREAD FOG DEVELOPMENT TONIGHT. A DENSE FOG
ADVISORY MAY BE NEEDED. THE GUIDANCE TEMPERATURES WERE CONSISTENT.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SUNDAY/...
THE PRESSURE RIDGE IN THE ATLANTIC WILL CONTINUE TO DIRECT WARM
AIR INTO THE FORECAST AREA. THE WARM ADVECTION PATTERN MAY HELP
SUPPORT SHOWERS BUT EXPECT LITTLE COVERAGE. THE MODELS KEEP DEEP
MOISTURE ASSOCIATED WITH A FRONT NORTH OF THE FORECAST AREA. THE
NAM AND GFS MOS INDICATE POPS LESS THAN 20 PERCENT THROUGH
SATURDAY NIGHT...AND 20 TO 30 PERCENT SUNDAY. HIGH LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING WILL LIKELY RESULT IN WIDESPREAD
FOG DURING THE EARLY MORNING HOURS. USED THE GUIDANCE CONSENSUS
FOR THE TEMPERATURE FORECAST.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE GFS AND ECMWF DISPLAY AN APPROACHING COLD FRONT MONDAY MOVING
INTO THE FORECAST AREA MONDAY NIGHT. THE MODELS SHOW THE FRONT
STALLING NEAR THE AREA WITH ANOTHER COLD FRONT MOVING INTO THE
AREA TOWARD THE END OF THE PERIOD. THE GFS AND ECMWF MOS HAVE
POPS OF 30 TO 60 PERCENT. THE MOS KEEPS TEMPERATURES ABOVE NORMAL
THROUGH THE PERIOD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
RESTRICTIONS EXPECTED TO CONTINUE THROUGH MUCH OF THE TAF PERIOD.
FRONTAL BOUNDARY HAS PUSHED NORTHWEST OF THE TAF SITES WITH
SHOWERS AND THUNDERSTORMS STRETCHED FROM THE WESTERN CAROLINAS
INTO NORTHERN GEORGIA. LOW CLOUDS AND FOG HAVE FINALLY DISSIPATED
AT THE TAF SITES...HOWEVER CUMULUS HAVE DEVELOPED IN AREAS WHERE
THE STRATUS HAS LIFTED. EXPECT VFR CONDITIONS TO CONTINUE THROUGH
TONIGHT UNTIL ANOTHER ROUND OF FOG AND STRATUS DEVELOPS OVER THE
AREA. HAVE INCLUDED LIFR CONDITIONS FOR ALL SITES FROM THE EARLY
MORNING HOURS THROUGH LATE MORNING AGAIN. WINDS THROUGH THE PERIOD
WILL BE SOUTHERLY AT 7 KNOTS OR LESS.
EXTENDED AVIATION OUTLOOK...RESTRICTIONS POSSIBLE MAINLY IN LATE
NIGHT AND MORNING FOG AND STRATUS THROUGH MONDAY. LOW CONFIDENCE
IN RESTRICTIONS MONDAY AFTERNOON THROUGH WEDNESDAY AS A SERIES OF
FRONTAL SYSTEMS MOVE THROUGH THE TAF SITES.
&&
.HYDROLOGY...
RIVER FLOOD WARNINGS HAVE BEEN POSTED FOR MOST OF OUR FORECAST
POINTS. STILL MONITORING THE N. FORK OF THE EDISTO AT ORANGEBURG.
THE SAVANNAH RIVER AT BUTLER CREEK IS ALSO QUITE HIGH BUT REMAINS
BELOW ADVISORY CRITERIA. THE HIGH WATER ALONG THE SAVANNAH RIVER
BELOW AUGUSTA WILL PRODUCE SOME FLOODING OF LOW LYING AREAS.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR THE DATES...
COLUMBIA METRO AIRPORT (CAE)
DEC 25...79 SET IN 1955
DEC 26...77 SET IN 1964
DEC 27...77 SET IN 1971
AUGUSTA BUSH FIELD (AGS)
DEC 25...79 SET IN 1984
DEC 26...80 SET IN 1964
DEC 27...76 SET IN 1971
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1136 AM CST FRI DEC 25 2015
.UPDATE...
ISSUED AT 950 AM CST FRI DEC 25 2015
Large area of stratus extending from Wisconsin to the north half
of Missouri this morning. The eastern fringe has scraped the
western edge of our forecast area, with rather persistent coverage
from Galesburg to Winchester, but a little bit of erosion was
taking place at mid morning. The HRRR has handled this well and
shows a bit more erosion of it in our area, but high clouds
streaming over the top will keep skies there mostly cloudy today.
The southeast CWA has seen mainly cirrus moving through. In
between, there is a decent amount of sunshine, but the cirrus will
be filling in with time during the afternoon.
Have sent some updates to remove the slight chance PoP`s in the
far southeast for this morning, and also adjusted the timing of
the PoP`s for tonight, concentrating them mostly after midnight.
&&
.SHORT TERM...(Today)
ISSUED AT 329 AM CST FRI DEC 25 2015
09z/3am surface analysis shows weak frontal boundary extending from
southern Ohio to Arkansas, with a 1023mb high noted further upstream
across Iowa. A few sprinkles have been occurring from time to time
across the E/SE KILX CWA in association with the Ohio River Valley
front and this trend will continue for the next few hours as per the
HRRR forecast. As a result, will carry slight chance for light
showers south of I-70. Meanwhile, an area of low clouds/fog trapped
beneath the subsidence inversion beneath the Iowa high has been
slowly spreading eastward over the past few hours. Latest satellite
shows the leading edge of the clouds along a Galesburg to Macomb
line. Based on satellite trends and HRRR cloud height forecast,
will feature overcast conditions along/west of the Illinois River
this morning. The low clouds will gradually dissipate toward
midday, followed by partly sunny conditions across the board through
afternoon. High temperatures will mainly be in the middle to upper
40s, with lower 50s across the E/SE.
.LONG TERM...(Tonight through Thursday)
ISSUED AT 329 AM CST FRI DEC 25 2015
Major rain event is still unfolding across parts of central and
southeast Illinois this weekend as deep-layer southwesterly flow
establishes itself across the region. As upper low cuts off over
the Desert Southwest and a corresponding ridge develops downstream
across the eastern CONUS, the Ohio River Valley frontal boundary
will lift northward into central Illinois late tonight into
Saturday. The front will then become parallel to the upper flow and
stall across the area. With baroclinic zone in place, plenty of
Gulf of Mexico moisture flowing northward, and weak upper waves
tracking through the southwest flow to provide enhanced lift...a
prolonged period of moderate to heavy rain will develop this
weekend. Models have continued to slow the process however, with
tonight now remaining mostly dry. Have lowered PoPs to just
slight chance across all but the far S/SE accordingly. As front
stalls, rain will begin in earnest on Saturday, then continue
through Saturday night. Thanks to increasing instability, may
even see a few thunderstorms as well. As seen for the past
several model runs, a northern stream short-wave tracking from the
Northern Plains into the Great Lakes will push the front further
south on Sunday. 00z Dec 25 models are in good agreement that
the boundary will drop well south of the Ohio River, resulting in
decreasing rain chances Sunday/Sunday night. In fact, have
dropped PoPs altogether along/north of a Rushville to Bloomington
line during the afternoon and as far south as the I-72 corridor by
evening. Further south, rain will continue to fall across the
remainder of the area through Sunday night.
A vigorous wave coming off the Pacific will eventually eject the
Desert Southwest closed upper low northeastward early next week,
with the latest models now in much better agreement concerning the
timing of this process. The exact track of the low still remains in
question however, which poses some big challenges to the PoP/precip
type forecast late Sunday night through Monday night. ECMWF remains
the further west with the track...taking the corresponding surface
low from near St. Louis midday Monday to Chicago by midnight.
Meanwhile both the GFS and GEM are further east...with the low
tracking from western Kentucky to northwest Ohio during that time
frame. Will follow the more consistent ECMWF here, which keeps the
KILX CWA warmer and results in mostly liquid precip. May see a
period of light freezing rain on the northern periphery of the
precip as it returns northward late Sunday night into Monday:
however, with warm nose aloft at 5-6C and surface temps only
slightly below freezing across the north, think any ice accumulation
will be minimal. Based on expected surface temps, will mention
freezing rain along/north of a Rushville...to Lincoln...to Danville
line. Temps will edge above freezing everywhere toward midday
Monday, resulting in a change over to all rain. As the low
approaches, may even see a few thunderstorms south of the I-72
corridor. Once the low tracks into the southern Great Lakes, enough
cold air will be pulled down behind it to support a change over to
snow or a rain/snow mix along/north of a Taylorville to Danville
line Monday night. Will need to keep an eye on this, as any
eastward deviation of the low track will lead to more snow and
possible accumulations across the area.
Precip will come to an end on Tuesday, with storm total rainfall
from tonight through Monday night ranging from around 1 inch
northwest of the Illinois River...to as much as 5-6 inches
along/south of I-70. With so much rain expected to fall on already
wet soil and the potential for thunderstorms to produce excessive
rainfall rates, will be issuing a Flash Flood Watch for areas
along/southeast of a Danville to Taylorville line starting midday
Saturday and ending Monday evening. Main concerns will be rapid
rises on area creeks/streams and urban flooding in poor drainage
areas.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1135 AM CST FRI DEC 25 2015
MVFR stratus deck has managed to avoid KPIA, hovering just to the
west. Starting to see some more in the way of diurnal development
around 1500 feet from near KSPI-KCMI, but any ceilings should be
brief.
Main concerns are later in the period, as a warm front lifts
northward toward central Illinois. Should see ceilings decrease to
MVFR levels toward 08-11Z from south to north. As areas of rain
become more widespread, IFR conditions should develop after
sunrise and continue the remainder of the forecast period. Winds
will generally be around 10 knots from the east overnight, but
will try to become more southeasterly toward midday as the front
gets closer.
&&
.ILX Watches/Warnings/Advisories...
Flash Flood Watch from Saturday afternoon through Monday
afternoon for ILZ052-054>057-061>063-066>068-071>073.
&&
$$
UPDATE...Geelhart
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Geelhart
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1138 AM CST FRI DEC 25 2015
.UPDATE...
ISSUED AT 1132 AM CST FRI DEC 25 2015
LOW LEVEL INVERSION HAS TRAPPED MOISTURE BELOW IT AND THUS CLOUDS.
BASED ON SATELLITE TRENDS SOME ERODING OF THE LOW CLOUDS IS
OCCURRING THE THE FAR SOUTHEAST. HOWEVER...SATELLITE AND RAP MODEL
TRENDS SUGGEST THE LOW CLOUDS PERSISTING THROUGH SUNSET.
AS SUCH THE FORECAST HAS BEEN UPDATED FOR THIS AND TO LOWER MAX
TEMPERATURES FOR THE DAY.
&&
.SYNOPSIS...
ISSUED AT 305 AM CST FRI DEC 25 2015
A DEEP TROUGH LIES ACROSS THE GREAT BASIN WITH SOUTHWEST FLOW
STRETCHING ACROSS MUCH OF THE CENTRAL AND EASTERN U.S. SURFACE
HIGH PRESSURE CENTERED OVER NORTHWEST MISSOURI IS SLOWLY SHIFTING
EASTWARD THIS MORNING AS INDICATED BY MSAS PRESSURE RISES. FOG IS
DEVELOPING IN CENTRAL IOWA JUST EAST OF THE RIDGE AXIS WHERE
VISIBILITIES AT A FEW LOCATIONS ARE CURRENTLY 1 MILE OR LESS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 305 AM CST FRI DEC 25 2015
MAIN CONCERN FOR THIS FORECAST PERIOD REVOLVES AROUND CLOUDS.
STRATUS DECK OVER MOST OF THE CWA APPEARS TO BE BREAKING UP IN
SPOTS. BUT SURFACE DEW POINT DEPRESSIONS ARE VERY LOW AND FOG IS
DEVELOPING IN CENTRAL IOWA. THUS EXPECT FOG TO DEVELOP OVER PARTS
OF EASTERN IOWA AT LEAST UNTIL MID MORNING WHEN IT SHOULD BEGIN
TO MIX OUT. A MIX OF SUN AND CLOUDS TODAY WILL ALLOW TEMPS TO
REACH NEAR OR SLIGHTLY HIGHER THAN THURSDAYS MAX TEMPS.
THE NEXT SYSTEM BEGINS TO TAKE SHAPE IN THE LEE OF THE ROCKIES AND
CLOUDS WILL BEGIN OVERSPREADING THE AREA DURING THE EVENING. IN
FACT RAIN COULD DEVELOP OVER THE WESTERN PART OF THE CWA AFTER
MIGHT AS 850 MB WARM FRONT LIFTS ACROSS THE CWA. TEMPS DURING THE
OVERNIGHT HOURS SHOULD BE STEADY OR SLOWLY RISING AFTER DROPPING
OFF DURING THE EVENING HOURS.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 305 AM CST FRI DEC 25 2015
MAIN FORECAST CONCERN IN THE LONG TERM IS SEVERAL POTENTIAL
OPPORTUNITIES FOR PRECIP THIS WEEKEND AND INTO NEXT WEEK.
SATURDAY... ENERGY WILL CONTINUE TO EJECT FROM THE LONG WAVE TROUGH
OVER THE SOUTHWESTERN US THROUGH THE MIDDLE OF NEXT WEEK. FIRST
WAVE NOW ROUNDING THE BASE OF THE TROUGH LIFTS OUT SATURDAY AND
RESULTS IN A RAIN CHANCE AREA WIDE. WITH TEMPERATURES MAINLY IN
THE 40S...DO NOT SEE A RISK FOR SNOW WITH THIS ROUND.
SUNDAY NIGHT THROUGH TUESDAY...THE RAIN MOVES OUT SUNDAY...TO BE
QUICKLY FOLLOWED BY THE NEXT ROUND SUNDAY NIGHT INTO MONDAY.
CONFIDENCE IN THE DETAILS FROM SUNDAY NIGHT THROUGH THE END OF THE
WEEK REMAINS VERY LOW DUE TO TREMENDOUS DISCREPANCIES BETWEEN THE
MODELS AND MODEL RUNS. GIST OF THE FORECAST IS THAT A CLOSED UPPER
LOW LIFTS OUT ACROSS THE SOUTHERN PLAINS MONDAY. GFS IS FARTHER
SOUTH THAN THE ECMWF. IF THE GFS IS RIGHT...STRONGEST DYNAMICS
WOULD TRACK SOUTHEAST OF OUR AREA. HOWEVER...IF THE ECMWF IS
CORRECT...THEN POTENTIAL FOR DECENT SNOWFALL AND MIXED PRECIP TYPES
IS A GREATER WORRY. GIVEN THE EXTREMELY LOW CONFIDENCE...HAVE
ADHERED TO A MODEL BLEND.
WEDNESDAY... YET ANOTHER OPEN WAVE COMES OUT WEDNESDAY. TEMPERATURES
SHOULD BE COLD ENOUGH BY THEN TO LIMIT THE CHANCE FOR MIXED PRECIP
ACROSS NEARLY ALL OF THE CWFA...AND FORECAST REFLECTS PRIMARILY A
CHANCE OF SNOW FOR THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1132 AM CST FRI DEC 25 2015
CONDITIONS RANGE FROM LIFR TO IFR IN A LAYER OF CLOUDS TRAPPED
BELOW THE INVERSION. MAINLY LIFR TO IFR CONDITIONS WILL PERSIST
THROUGH 06Z/26 BEFORE IMPROVING TO MVFR. AFT 12Z/26 THE NEXT ROUND
OF PRECIPITATION WILL MOVE INTO EASTERN IOWA/NORTHERN ILLINOIS
WITH MVFR/IFR CONDITIONS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...WOLF
SHORT TERM...WOLF
LONG TERM...DMD
AVIATION...08
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1043 AM MST FRI DEC 25 2015
.UPDATE...
ISSUED AT 819 AM MST FRI DEC 25 2015
LIGHT PRECIPITATION TAKING A BIT LONGER TO EXIT THE AREA...SO HAVE
EXTENDED CHANCES FOR SNOW AS A RESULT. ALSO INCREASED CHANCES FOR
SNOW LATE THIS AFTERNOON OVER YUMA COUNTY DUE TO A BAND OF LOW
LEVEL FRONTOGENESIS DEVELOPING THERE CO-LOCATED WITH THE FRONT.
STILL NOT SURE HOW QUICKLY AND HOW MUCH OF THE PRECIPITATION WILL
MOVE ACROSS THE AREA TONIGHT. WILL SEE WHAT THE LATEST HIGH
RESOLUTION DATA SAYS. WILL ALSO NEED TO DETERMINE WHEN/WHERE THE
SNOW CHANGES TO FREEZING DRIZZLE DUE TO THE SATURATED LAYER
BECOMING VERY SHALLOW AS IT MOVES EAST WITH THE FRONT.
UPDATE ISSUED AT 654 AM MST FRI DEC 25 2015
BASED ON SOUNDINGS HAVE INCREASED THE WINDS FOR THIS AFTERNOON
BEHIND THE WARM FRONT. GUSTS UP TO 30 MPH CAN BE EXPECTED BY EARLY
AFTERNOON.
UPDATE ISSUED AT 527 AM MST FRI DEC 25 2015
UPDATED THE GRIDS AND ZONES TO ADD SOME ISOLATED FLURRIES IN THE
EASTERN FA. THE HRRR MODEL INDICATES THAT THE FLURRIES SHOULD END
AROUND 15Z THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 209 AM MST FRI DEC 25 2015
SOUTHWEST FLOW WILL PERSIST OVER THE CENTRAL PLAINS FROM TODAY
THROUGH SATURDAY NIGHT WITH A RIDGE BUILDING INTO THE ROCKIES AND
THEN THE PLAINS SUNDAY AND SUNDAY NIGHT. A SURFACE LOW WILL BE
PRESENT OVER CENTRAL COLORADO TODAY. THIS AREA OF LOW PRESSURE WILL
SHIFT EAST INTO WESTERN KANSAS THIS EVENING AND THEN MOVE INTO
EASTERN KANSAS AS A COLD FRONT DIVES SOUTH ACROSS THE REGION. HIGH
PRESSURE WILL MOVE INTO THE CENTRAL PLAINS SATURDAY AND RESIDE OVER
HT AREA THROUGH SUNDAY NIGHT.
DYNAMICS START MOVING INTO THE FA LATE THIS AFTERNOON AND EVENING
BUT MOISTURE IS LIMITED TO THE FAR NORTHWEST FA WHERE THERE WILL BE
SLIGHT CHANCE POPS LATE THIS AFTERNOON INCREASING TO CHANCE POPS
THIS EVENING. FORECAST SOUNDINGS ACROSS THE FA INDICATE THE
POSSIBILITY OF SOME LIGHT FREEZING DRIZZLE AND PATCHY FOG FOR THE
EVENING. A DRY SLOT WILL MOVE NORTHWARD INTO THE FA BY 06Z SATURDAY.
CONSEQUENTLY WILL LOWER POPS OVER THE FAR NORTHWEST TO SLIGHT
CHANCE. DYNAMICS AND MOISTURE DECREASE ON SATURDAY AS THE UPPER LOW
SHIFTS FAR TO THE SOUTH REMOVING ANY POTENTIAL FOR PRECIPITATION.
CONSEQUENTLY POPS WILL BE NIL THROUGH SUNDAY. IF THE SYSTEM TAKES A
SLOWER AND MORE NORTHERLY TRACK SUNDAY NIGHT THERE COULD BE A SLIGHT
CHANCE OF LIGHT SNOW ACROSS THE SOUTHEAST FA. THE GFS MODEL IS
FASTER AND IF ITS SOLUTION BECOMES A REALITY THERE WILL BE NO
PRECIPITATION IN THE SOUTHEAST SUNDAY NIGHT.
MAX TEMPERATURES TODAY SHOULD WARM TO THE MID 40S WITH THE EXCEPTION
OF UPPER 30S ACROSS THE FAR NORTHERN FA. A COLD FRONT TONIGHT WILL
KEEP DAYTIME TEMPERATURES FROM RISING MUCH ABOVE THE MORNING LOWS.
DAYTIME TEMPERATURES SATURDAY SHOULD RANGE FROM THE MID TEENS IN THE
NORTHWEST TO THE MID 20S IN THE EAST. MAX TEMPERATURES SUNDAY
SHOULD BE IN THE MID 20S. MIN TEMPERATURES TONIGHT SHOULD RANGE
FROM THE TEENS IN THE NORTHWEST TO THE MID 20S IN THE EAST. MIN
TEMPERATURES SATURDAY AND SUNDAY NIGHTS SHOULD RANGE FROM THE UPPER
SINGLE DIGITS IN THE NORTHWEST TO THE MID AND UPPER TEENS.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 209 AM MST FRI DEC 25 2015
THE EXTENDED PERIOD IS CONTINUING TO FOCUS/MONITOR THE IMPACT OF THE
CLOSED LOW ON THE CWA...IF ANY IMPACT AT ALL.
MONDAY...THE CLOSED LOW IN BOTH THE GFS AND EUROPEAN IS LOCATED OVER
THE NORTH EASTERN SIDE OF TEXAS INTO OKLAHOMA/ARKANSAS. BUT A FEW
DIFFERENCES ARE...ONE...THE STRENGTH OF THE LOW. THE GFS HAS IT
WEAKER WHEREAS THE EUROPEAN HAS IT MUCH STRONGER. SECOND...THE RIDGE
IN THE EAST/SOUTHEAST OF THE CONUS. THE GFS HAS IT BREAKING DOWN AND
PUSHING SOUTH QUICKER THAN THE EUROPEAN...WHICH IS PLAYING A STRONG
ROLE IN THE MOVEMENT OF THE LOW...WHICH IS WHY THE EUROPEAN STILL
HAS POPS IN THE FORECAST OVER THE CWA AND THE GFS DOES NOT. AGAIN
THE CR EXTENDED INITIALIZATION IS FAVORING THE EUROPEAN...BUT AS WE
GET CLOSER TO THE EVENT POPS MY NEED TO BE LOWERED EVEN MORE IF THE
GFS TRACT HOLDS MORE WATER.
TUESDAY...AFTER THE CLOSED LOW MOVES EAST OF THE CWA THERE IS A
UPPER LEVEL TROUGH THAT WILL MOVE INTO THE AREA TUESDAY NIGHT THAT
HAS POTENTIAL TO BRING SLIGHT CHANCES FOR LIGHT SNOW. BUT THE GFS IS
DRIER THAN THE EUROPEAN...SO POPS THAT WERE KEPT IN THE FORECAST ARE
DEPENDENT ON THE EUROPEAN...ONCE AGAIN.
WEDNESDAY/THURSDAY...CONDITIONS START TO DRY OUT. IT IS FAR OUT IN
THE EXTENDED BUT THE GFS HAS THE SAME TROUGH THAT MOVED INTO THE CWA
TUESDAY NIGHT CONTINUING TO IMPACT THE HIGH PLAINS...WHICH WILL
CONTINUE TO KEEP TEMPERATURES DOWN. THE EUROPEAN HAS MORE OF A ZONAL
FLOW OVER THE CWA.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1040 AM MST FRI DEC 25 2015
VFR TO IFR CONDITIONS FORECAST FOR THE 18Z TAFS. ASIDE FROM THE
WIND THE MAIN ISSUE WILL BE TIMING OF THE LOW CEILINGS WHEN THE
COLD FRONT MOVES IN TONIGHT. LOOKS LIKE THE TREND IS EARLIER IN
THE NIGHT. BEHIND THE FRONT TOMORROW MORNING THE WINDS WILL
INCREASE...WITH STRONGER WINDS EXPECTED THAN EARLIER THIS
MORNING.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...JTL
SHORT TERM...FS
LONG TERM...CLT
AVIATION...JTL
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
200 PM CST FRI DEC 25 2015
.SHORT TERM...(This evening through Sunday night)
Issued at 112 PM CST FRI DEC 25 2015
HRRR keeps all pcpn out (south and east) of FA thru midnight
tonight. It`s even sparse on bringing it in after, although it
only runs thru 08z at this writing. The synoptic scale models are
not doing as good a job seeing the convection to the south (MS/AL)
and its negating effect on the northern extent of the pcpn
shield. Thus the nearly half inch qpf in our southern counties
thru midnight, will be discarded.
After midnight, we should see the boundary return as a warm front
slowly but surely. Pcpn will start, and get going pretty good,
certainly by midday tmrw, if not before. Where will the boundary
be? The synoptic models suggest it will set up somewhere along the
lower OH by early pm, but they could contain the same bias and
thus it be actually 50-75 miles south of there, or, just entering
the FA. Either case, rain should pick up to categorical tmrw, as
the warm front lifts thru the region. As it does so, low level
winds pick up, and elevated instability becomes sufficient for
embedded thunder. Some low layer mucape is present as well, so
we`ll include a chance, or slgt chance, thunder, with the lift
thru of the warm front. Expect 1/2 to 3/4 inches areal average qpf
with this round.
We have the warm front lifted across the area by 00Z Sunday, with
the aforementioned convective caveat perhaps hanging up its lift
in entirety. We`ve lingered higher pops along the northern and
western counties to account for that...and extend that trend thru
Saturday night. It`s possible showers become more widely
scattered/scarce further east with time...so we`ve lowered pops
there (southern Pennyrile) to account for that. We`ve slightly
adjusted forecast QPF similarly with these two trends (up n/w,
down s/e) just a little.
Sunday-Sunday night offers the best chance for heavier
rains/additional qpf, particularly for our northern and western
counties. The sagging front interaction with the incoming parent
Low pressure systems may set up a weak zone of baroclinicity that
allows for enhanced pcpn/qpf potential there. Hence the qpf
bullseye of 4-5" across SEMO into SWIL, where the FFA exists. Per
collab with LMK, we`ll lay off headline FFA for points east for
now, as these aforementioned heavier/cumulative qpf rains may be
more in the late Sunday-Sunday night-Monday time frame there.
.LONG TERM...(Monday through Friday)
Issued at 200 PM CST FRI DEC 25 2015
Forecast confidence is average to above average in the long term
portion of the forecast. Overall synoptic scale model forecasts are
in generally good agreement. However, smaller scale details remain
somewhat in flux--especially with respect to how quickly the system
and heavy rains depart the area early in the week.
The main concern to start the long term is the continued potential
for flooding from the rain event slated to get underway over the
weekend. In collaboration with the short term, a Flash Flood Watch
will continue through Monday for most of southeast Missouri and
northern/western portions of southern Illinois. During this time,
the primary closed upper low is forecast to move northeast from the
southern Plains into the Great Lakes Region. Forecast currently
relies largely on a consensus blend of recent model data. However,
latest 12Z runs of the GFS, ECMWF, NAM, and GEM seem to suggest much
of the area may be dry slotted by late Monday morning and afternoon.
If this does pan out, a lowering of rain chances and forecast
precipitation totals may become necessary in future forecasts for
Monday.
Once the storm system and heavy rain have cleared the area, a return
to mainly dry conditions is anticipated through the remainder of the
week. The southwesterly upper flow pattern will persist through mid
week. Thereafter, a substantial shift to the pattern is anticipated
as an upper level ridge builds in the west and a trough sets up in
the east. The resultant transition to a northwest flow pattern will
usher much colder air into the region by mid to late week. As this
transition occurs, the passage of our next system may yield some
light precipitation around Wednesday. However, with most of the Gulf
moisture remaining to our south, any precipitation would likely
remain on the light side.
&&
.AVIATION...
Issued at 112 PM CST FRI DEC 25 2015
Satellite/radar and HRRR model data all paint a relatively dry
first half of forecast. A warm front will return overnight, and
with it, MVFR restricted cigs/vsbys in light rain. While it is
introduced south (KCGI/KPAH) prior to midnight, in reality it may
be after midnight before the combined effects are ushered in. By
tmrw morning, however, pockets of heavier rain with the front`s
passage will be presenting IFR cigs/vsbys as flight hazards, and
restricted flight rules will continue thru the remainder of the
valid time.
&&
.PAH Watches/Warnings/Advisories...
IL...Flash Flood Watch from Saturday afternoon through Monday
afternoon for ILZ075>078-080>082-084.
MO...Flash Flood Watch from Saturday afternoon through Monday
afternoon for MOZ076-086-087-100-107>111-114.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
130 PM CST FRI DEC 25 2015
.SHORT TERM...(This evening through Sunday night)
Issued at 112 PM CST FRI DEC 25 2015
HRRR keeps all pcpn out (south and east) of FA thru midnight
tonight. It`s even sparse on bringing it in after, although it
only runs thru 08z at this writing. The synoptic scale models are
not doing as good a job seeing the convection to the south (MS/AL)
and its negating effect on the northern extent of the pcpn
shield. Thus the nearly half inch qpf in our southern counties
thru midnight, will be discarded.
After midnight, we should see the boundary return as a warm front
slowly but surely. Pcpn will start, and get going pretty good,
certainly by midday tmrw, if not before. Where will the boundary
be? The synoptic models suggest it will set up somewhere along the
lower OH by early pm, but they could contain the same bias and
thus it be actually 50-75 miles south of there, or, just entering
the FA. Either case, rain should pick up to categorical tmrw, as
the warm front lifts thru the region. As it does so, low level
winds pick up, and elevated instability becomes sufficient for
embedded thunder. Some low layer mucape is present as well, so
we`ll include a chance, or slgt chance, thunder, with the lift
thru of the warm front. Expect 1/2 to 3/4 inches areal average qpf
with this round.
We have the warm front lifted across the area by 00Z Sunday, with
the aforementioned convective caveat perhaps hanging up its lift
in entirety. We`ve lingered higher pops along the northern and
western counties to account for that...and extend that trend thru
Saturday night. It`s possible showers become more widely
scattered/scarce further east with time...so we`ve lowered pops
there (southern Pennyrile) to account for that. We`ve slightly
adjusted forecast QPF similarly with these two trends (up n/w,
down s/e) just a little.
Sunday-Sunday night offers the best chance for heavier
rains/additional qpf, particularly for our northern and western
counties. The sagging front interaction with the incoming parent
Low pressure systems may set up a weak zone of baroclinicity that
allows for enhanced pcpn/qpf potential there. Hence the qpf
bullseye of 4-5" across SEMO into SWIL, where the FFA exists. Per
collab with LMK, we`ll lay off headline FFA for points east for
now, as these aforementioned heavier/cumulative qpf rains may be
more in the late Sunday-Sunday night-Monday time frame there.
.LONG TERM...(Monday through Thursday)
Issued at 325 AM CST FRI DEC 25 2015
Models are in decent agreement for the period.
Well advertised storm system which will be centered over the
southern Plains/mid Mississippi Valley by 12z Monday will lift
northeast and out of the area by 12z Tuesday. ECMWF is a bit farther
north than the GFS or GEFS but otherwise very similar.
The eastern sections of the CWA are the most likely area to get dry
slotted during the day on Monday. So, although much of the area will
see moderate to heavy rain on Monday, the northwest sections are more
in line to see a prolonged period of heavy rain which is in line with
the flash flood watch being issued.
As this first system moves northeast out of the picture another piece
of energy will come out of the southwest US. This begins a major
pattern change from the current trough in the west/ridge in the east to
ridge in the west/trough in the east. This second system will reach us
late Wednesday into Thursday but will be moisture starved, so some
light rain is possible. As the trough sets up over the eastern US our
high temperatures will actually go to near normal (low-mid 40s). This
new pattern may stick around a while.
&&
.AVIATION...
Issued at 112 PM CST FRI DEC 25 2015
Satellite/radar and HRRR model data all paint a relatively dry
first half of forecast. A warm front will return overnight, and
with it, MVFR restricted cigs/vsbys in light rain. While it is
introduced south (KCGI/KPAH) prior to midnight, in reality it may
be after midnight before the combined effects are ushered in. By
tmrw morning, however, pockets of heavier rain with the front`s
passage will be presenting IFR cigs/vsbys as flight hazards, and
restricted flight rules will continue thru the remainder of the
valid time.
&&
.PAH Watches/Warnings/Advisories...
IL...Flash Flood Watch from Saturday afternoon through Monday
afternoon for ILZ075>078-080>082-084.
MO...Flash Flood Watch from Saturday afternoon through Monday
afternoon for MOZ076-086-087-100-107>111-114.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1249 PM EST FRI DEC 25 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 512 AM EST FRI DEC 25 2015
WATER VAPOR IMAGERY AND RAP ANALYSIS SHOW A BROAD TROF DOMINATING
MOST OF W AND CNTRL NAMERICA WHILE A STRONG RIDGE IS LOCATED JUST
OFF THE E COAST OF THE CONUS. RESULT IS SW FLOW OVER THE UPPER GREAT
LAKES EARLY THIS MORNING. LATEST RAP ANALYSIS SHOWS MOISTURE TRAPPED
BLO 4-5KFT WITH LOWEST TEMPS IN THE MOIST LAYER RIGHT AROUND
-10C. KMQT RADAR IS HINTING AT VERY LIGHT LES OVER ERN LAKE
SUPERIOR AT TIMES...AND MONTREAL RIVER ONTARIO RADAR DOES IN FACT
SHOW A FEW LIGHT LES BANDS. TO THE W...WEAK SHORTWAVE MOVING ACROSS
NRN MN IS GENERATING SOME -SN WHICH IS NOW MOVING OUT OVER WRN LAKE
SUPERIOR.
IN THE NEAR TERM...AS WEAK FORCING PROVIDED BY UPSTREAM SHORTWAVE
PASSES OVER LAKE SUPERIOR DURING THE NEXT SEVERAL HRS...AREA OF -SN
WILL BECOME ENHANCED OVER THE RELATIVELY WARM WATERS. WILL BE SHORT-
LIVED...BUT UNDER WSW WINDS...THE KEWEENAW MIGHT SEE UP TO AN INCH
OF SNOW THIS MORNING BEFORE -SHSN DIMINISH...THEN END EARLY THIS
AFTN. OTHERWISE...MODELS ARE FAIRLY AGGRESSIVE IN DECREASING CLOUDS
THIS AFTN AWAY FROM THE KEWEENAW WHERE WINDS REMAIN OFF LAKE
SUPERIOR THRU THE DAY. ALWAYS A TOUGH CALL THIS TIME OF YEAR WITH
LOW SUN ANGLE...BUT OPTED TO TREND SKY TO MOSTLY SUNNY GIVEN
OPTIMISTIC INDICATION FROM THE MAJORITY OF MODELS. BEST CHC FOR
CLEARING WILL BE IN THE AREAS THAT HAVE DOWNSLOPING UNDER A WSW
WIND.
TONIGHT...WITH THE POTENTIAL FOR LOW CLOUDS TO BE MOSTLY OUT OF THE
AREA AND WITH ONLY HIGH CLOUDS ARRIVING AND THICKENING FROM THE W
AND SW....TEMPS MAY HAVE AN OPPORTUNITY TO FALL DECENTLY UNDER
LIGHT/CALM WIND. BIAS CORRECTED REGIONAL AND GLOBAL CANADIAN MODEL
TEMPS TYPICALLY PICK UP ON RADIATIONAL COOLING BEST AND HAVE
INCORPORATED THEIR OUTPUT IN MIN TEMP FCST. BOTH SHOW MINS AS LOW AS
AROUND 10F OVER THE INTERIOR W. FOR NOW...LOWERED MINS TO THE MID
TEENS AT THE LOWEST. THE INCREASING/THICKENING HIGH CLOUDS WILL BE
THE HARBINGER OF A SNOW EVENT FOR SAT/SAT EVENING GENERATED BY A
DISTRUBANCE LIFTING OUT OF THE WRN TROF AND RIGHT ENTRANCE OF UPPER
JET EXTENDING ACROSS MN AND NRN ONTARIO. THE FORCING BEGINS TO
SPREAD INTO WRN UPPER MI LATE TONIGHT...BUT THERE IS PLENTY OF DRY
AIR TO SATURATE IN THE MID TO LOWER LEVELS. THAT SHOULD DELAY PCPN
FROM REACHING THE GROUND FOR A TIME. LEANED TOWARD THE MODELS
SHOWING SLOWER PCPN DEVELOPMENT...RESULTING IN CHC POPS INTO FAR WRN
UPPER MI LATE TONIGHT WITH SCHC AS FAR E AS ROUGHLY
HOUGHTON/BARAGA/CRYSTAL FALLS BY 12Z.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 455 AM EST FRI DEC 25 2015
THE MAIN FOCUS IS ON THE POTENTIAL FOR MODERATE SNOWFALL ACROSS THE
NORTHWEST HALF OF UPPER MI ON SATURDAY AND SATURDAY EVENING.
SATURDAY AND SATURDAY EVENING...THE PHASING OF A SHORTWAVE TROUGH
EJECTING FROM A LARGER TROUGH OVER THE SW STATES...AND ANOTHER
SHORTWAVE TROUGH DIGGING SE FROM BRITISH COLUMBIA...WILL BE STARTING
ACROSS THE UPPER AND MID MS VALLEY SAT MORNING. AHEAD OF THESE
TROUGHS...MODEST ISENTROPIC LIFT ON THE 290 TO 300K THETA SURFACES
UNDER SLOPING MID-LEVEL FGEN AND THE RIGHT ENTRANCE OF A
STRENGTHENING UPPER JET STREAK WILL SUPPORT MODERATE SNOW ACROSS THE
NW HALF OF THE CWA FROM AROUND DAYBREAK SATURDAY INTO SATURDAY
EVENING. THE BEST LIFT FROM WAA/ISENTROPIC ASCENT AND THE ACTIVE MID-
LEVEL FGEN WILL BE SOMEWHAT DISCONNECTED...RESULTING IN THE
POTENTIAL FOR A LOCALLY HEAVY SNOW BAND EMBEDDED WITHIN MORE
WIDESPREAD LIGHT TO MODERATE SNOW FOR ALL BUT THE EASTERN CWA. MODEL
GUIDANCE HAS BEEN MOVING AROUND THE BAND OF HEAVIER PRECIP...SO
PEGGING THE LOCATION WITH HIGHEST SNOW AMOUNTS REMAINS A CHALLENGE.
WITH THAT SAID...HIGH RES GUIDANCE IS WIDELY SUPPORTING A NARROW
COUNTY-WIDE SWATH OF 0.5 TO 0.7 INCHES OF PRECIP FROM 12Z SAT TO 06Z
SUNDAY. WITH A DEEP DGZ LOCATED WITHIN THE ACTIVE FGEN LAYER...SNOW
RATIOS SHOULD BE RATHER HIGH AT AROUND 17 OR 18 TO 1. AWAY FROM THE
MAIN FGEN BAND...RATIOS WILL BE CLOSER TO 14 OR 15 TO 1. PUTTING
THIS ALL TOGETHER...CHANCES LOOK FAIRLY GOOD FOR A SOLID 3 TO 6
INCHES OF SNOW FOR THE NW HALF OF THE CWA...WITH THE POTENTIAL FOR A
NARROW BAND OF UP TO 9 INCHES. THIS IS ESPECIALLY TRUE IF THE BAND
ALIGNS WITH LOW-LEVEL NE UPSLOPE ACROSS THE NORTH CENTRAL.
GIVEN THE RATHER LOW CONFIDENCE ON BAND PLACEMENT...INCLUDING THE
POTENTIAL FOR THE BAND TO REMAIN OVER LAKE SUPERIOR...AND GIVEN THAT
THE MAIN SNOW IS STILL GREATER THAN 30 HOURS OUT...HAVE OPTED TO
ISSUE A SPS FOR THE NW HALF HIGHLIGHTING THE SNOW ALONG WITH MINOR
POST-HOLIDAY TRAVEL DISRUPTIONS.
REST OF THE PERIOD...LIGHT TO SOMETIMES MODERATE LES WILL LINGER
ALONG LAKE SUPERIOR THROUGH SUNDAY NIGHT FOR THE N AND NW WIND
SNOWBELTS AS -15 TO -20C H8 AIR FILTERS OVER LAKE SUPERIOR ON
SUNDAY. GENERALLY SHALLOW INVERSIONS AT OR LESS THAN 4KFT WILL
HINDER OVERALL LES INTENSITY. BUT WITH THE CLOUD LAYER COMPLETELY
WITHIN THE DGZ AT TIMES...VERY FLUFFY SNOW CAN BE EXPECTED. IF
CLOUDS CAN CLEAR ENOUGH SUNDAY NIGHT...TEMPS MAY FALL TO NEAR ZERO
ACROSS THE INTERIOR WEST WHERE FRESH SNOW HAS FALLEN.
LOTS OF UNCERTAINTY AS THE UPPER LOW THAT WILL FORM OVER THE
U.S./MEXICO BORDER LOOKS TO BREAK DOWN AND SHIFT THROUGH THE REGION
TUE INTO TUE NIGHT. OVERALL GUIDANCE CONTINUES TO KEEP THE MAIN
TROUGH TO THE SE OF THE CWA ON TUESDAY...WITH THE ECMWF REMAINING
THE OUTLIER BY BRINGING THE TROUGH NEAR UPPER MI. WILL CONTINUE TO
HEDGE TOWARD A DRIER SOLUTION...WITH LES POSSIBLE FOR THE EAST WIND
SNOW BELTS OF LAKE SUPERIOR AND LAKE MI.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1248 PM EST FRI DEC 25 2015
CLOUDS AT KIWD AND KSAW STILL EXPECTED TO SCATTER OUT DUE TO
DOWNSLOPING WINDS...BUT THAT IS LESS LIKELY TO HAPPEN AT KCMX.
OTHERWISE...SIGNIFICANT WEATHER WILL RETURN SAT AS A BAND OF SNOW
MOVES INTO THE AREA AND LAKE ENHANCEMENT COMMENCES. NOT SURE WHERE
HEAVIEST SNOW/LOWER VIS WILL BE...BUT SHOULD SEE LOW CIGS/VIS AT ALL
SITES...WITH POTENTIAL FOR HEAVY SNOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 512 AM EST FRI DEC 25 2015
WESTERLY WINDS WILL INCREASE TO 15-25KT TODAY AHEAD OF A HIGH PRES
RIDGE WHICH ARRIVES TONIGHT. WINDS MAY REACH 20-30KT AROUND THE TIP
OF THE KEWEENAW PENINSULA. UNDER THE HIGH PRES RIDGE...WINDS WILL
DIMINISH TO UNDER 15KT TONIGHT. AS THE RIDGE SHIFTS N AND A LOW PRES
TROF SETS UP FROM THE SRN PLAINS TO THE LOWER GREAT LAKES...NE WINDS
WILL INCREASE SAT...REACHING AS HIGH AS 20-30KT OVER WRN LAKE
SUPERIOR. WINDS OF 15-25KT TO 20-30KT WILL THEN MOSTLY BE THE RULE
SUN THRU TUE.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KLUBER
AVIATION...TITUS
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
606 PM EST FRI DEC 25 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL OVER THE MID ATLANTIC REGION TONIGHT
AND LIFT NORTHWARD ON SATURDAY. SUNDAY AND MONDAY...A SERIES OF
STRONG LOW PRESSURE SYSTEMS WILL TRACK FROM THE SOUTHERN PLAINS TO
THE GREAT LAKES.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 550 PM EST FRIDAY...
GOING TO CUT POPS BACK SOME OVER THE NW AS NARROW BAND OF SHOWERS
IS MAINLY LINED UP ALONG A ZONE OF LOW LVL CONVERGENCE FROM TRI-
BCB...EAST TO LYH. THE LATEST GFS PLUS HIGH-RES MODELS SHOWING
MORE OF A SWD SHIFT THROUGH THIS EVENING. WILL HAVE TO WATCH THE
DEEPER CONVECTION OVER MID TN EARLY THIS EVENING...AND SEE HOW IT
SHIFTS EAST OR NORTHEAST ALONG THE FRONTAL BOUNDARY.
STILL THINK FOG WILL BECOME AN ISSUE OVER THE WEST THROUGH
TONIGHT. WILL HAVE TO MONITOR HOW WIDESPREAD AND DENSE FOG
GETS...TO DECIDE BETWEEN A DENSE FOG ADVISORY VS SPECIAL WX
STATEMENT.
PREVIOUS AFTERNOON DISCUSSION...
A FRONTAL BOUNDARY WITH SEVERAL WAVES OF LOW PRESSURE STALLS THIS
EVENING INTO TONIGHT ACROSS THE REGION AND THEN PUSHES NORTHWARD ON
SATURDAY. AN AREA OF LOW PRESSURE IN WEST VIRGINIA THIS AFTERNOON
WILL LIFT NORTHEAST AND REACH THE JERSEY SHORE TONIGHT. A SECOND
AREA OF LOW PRESSURE WILL ROTATE NORTHWARD ALONG THE BOUNDARY
TONIGHT WITH ADDITIONAL SHOWERS. THE DAY 1 EXCESSIVE RAINFALL PLACED
THE WESTERN HALF OF THE FORECAST AREA UNDER A SLIGHT RISK. CURRENT
WSR-88D SHOWED A BAND OF SHOWERS AND THUNDERSTORMS FROM WEST
VIRGINIA SOUTHWARD TO EASTERN AND MIDDLE TENNESSEE. ELECTED TO
EXTEND OUR FLASH FLOOD WATCH UNTIL MIDNIGHT...GIVEN THAT WITH RECENT
RAINFALL AND LOW FFG...IT WILL NOT TAKE MUCH TO PRODUCE FLASH
FLOODING IN THE REGION. DAY ONE CONVECTIVE OUTLOOK STILL SHOWS A
MRGL THREAT FOR SEVERE...WITH THE POTENTIAL FOR LOCALLY STRONG WIND
GUSTS INTO THIS EVENING. MCS OVER EASTERN KENTUCKY/TENNESSEE IS
PROGGED TO SPREAD EAST OF THE BLUE RIDGE LATER TODAY...WHERE IT WILL
INTERACT WITH A SEASONABLY WARM AND MOIST AIR MASS. SEVERE THREAT
WILL BE HINDER BY POOR WEAK INSTABILITY...AND POOR LAPSE RATES OVER
OUR AREA. THE HIRESW-ARW...RNK WRF AND HRRR TAKE THE AREA OF
CONVECTION TO OUR WEST AND MOVED IT EASTWARD ACROSS OUR FORECAST
AREA THIS AFTERNOON INTO TONIGHT. THE GFS...NAM AND ECMWF DROP THE
CONVECTION WITH THE FRONTAL BOUNDARY SOUTH THROUGH 00Z TO 03Z THIS
EVENING. IN ANY CASE...PLAYED THE HIGHEST POPS ACROSS THE
NORTHWEST...WITH THE LOWEST ALONG THE EASTERN SLOPES OF THE
SOUTHERN BLUE RIDGE MOUNTAINS. IT WILL BE ANOTHER MILD
NIGHT...WITH LOW TEMPERATURES FROM THE LOWER 50S IN THE NORTHERN
MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
OUR UNSEASONABLY WARM AND UNSETTLED PATTERN WILL CONTINUE SATURDAY.
THE UPPER PATTERN WILL FEATURE AN EASTERN RIDGE AS A CLOSED LOW
DEVELOPS OVER TEXAS AND THEN EJECTS INTO THE OHIO VALLEY. THIS WILL
PUSH THE FRONTAL BOUNDARY...WHICH HAS BEEN WAVERING AROUND THE
REGION FOR THE LAST SEVERAL DAYS...BACK TO THE NORTH AND KEEP THE
BEST CHANCES FOR PRECIPITATION...MAINLY NORTH OF ROUTE 460. HIGH
TEMPERATURES SATURDAY WILL RANGE FROM THE LOWER 60S IN THE NORTHERN
MOUNTAINS TO LOWER AND MID 70S IN THE PIEDMONT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 130 PM EST FRIDAY...
RELATIVE BREAK IN THE WET WEATHER EXPECTED OVER THE BLACKSBURG
FORECAST AREA FROM SATURDAY NIGHT THROUGH AT LEAST EARLY SUNDAY
NIGHT WITH ONLY SPOTTY WARM SECTOR SHOWERS POSSIBLE AS VERY STRONG
TROPICAL RIDGE OF HIGH PRESSURE OFF THE SE COAST OF THE NATION
DEFLECTS NORTHERN STREAM ENERGY AND MORE ROBUST PRECIPITATION FIELDS
CLOSER TO BAROCLINIC ZONE TO THE NORTH OF THE AREA. ANY RESIDUAL
COOL WEDGE ACROSS NORTHEASTERN PORTION OF THE FORECAST AREA SHOULD
RETREAT NORTH AND OUT OF THE AREA BY OR SHORTLY AFTER DAYBREAK ON
SUNDAY AS SE COASTAL RIDGE STRENGTHENS.
HOWEVER...SITUATION WILL BEGIN TO CHANGE LATER SUNDAY NIGHT INTO
MONDAY AS YET ANOTHER...AND THIS TIME STRONGER NORTHERN STREAM WAVE
MOVES EAST THROUGH THE GREAT LAKES AND NEW ENGLAND...SUPPORTING
SOUTHEASTWARD PUSH OF COOLER HIGH PRESSURE INTO SOUTHEASTERN
CANADA...WHICH THEN RIDGES SOUTHWEST INTO THE MID ATLANTIC REGION
MONDAY AFTERNOON INTO MONDAY NIGHT. MEANWHILE...YET ANOTHER
FORMIDABLE LOW LATITUDE CLOSED LOW WILL DRIFT NORTHEAST ON THE
WESTERN PERIPHERY OF THE UPPER RIDGE ALONG THE SE COAST...GRADUALLY
LIFTING AND FILLING AS IT MOVES UP THROUGH THE MS/TN/OH VALLEYS.
APPROACH OF THE WESTERN SYSTEM...AND MOVEMENT OF COOL SURFACE HIGH
PRESSURE TO AN OFFSHORE POSITION TO OUR NORTHEAST WILL RESULT IN
SLOWLY VEERING LOWER TROPOSPHERIC WINDS BACK INTO AN UPSLOPE
COMPONENT ON MONDAY...WHICH SHOULD BEGIN THE NEXT ROUND OF
WIDESPREAD PRECIPITATION FOR THE REGION. PRECIPITATION WILL
INITIALLY BE CONFINED TO LIGHT RAIN AND DRIZZLE ACROSS THE EASTERN
FLANKS OF THE APPALACHIANS LATE SUNDAY NIGHT INTO EARLY MONDAY AS
UPSLOPE COMPONENT INCREASES...BUT THEN EXPAND TO A WIDESPREAD
COVERAGE ACROSS THE ENTIRE FORECAST AREA MONDAY AFTERNOON INTO
MONDAY NIGHT AS UPWARD VERTICAL MOTION FIELDS INTENSIFY AS A RESULT
OF INCREASING WARM MOIST ADVECTION AND APPROACH OF RIGHT ENTRANCE
REGION OF UPPER JET MAXIMA.
WITH GROUND CONDITIONS ALREADY SATURATED...AND WATER LEVELS IN AREA
STREAMS/CREEKS AND RIVERS ALREADY RUNNING HIGH FROM RECENT RAINS...
THREAT FOR ADDITIONAL FLOODING/FLASH FLOODING WILL AGAIN EXIST FROM
MONDAY AFTERNOON INTO MONDAY NIGHT UNTIL CHANGE OF AIRMASS OCCURS
WITH COLD FRONTAL PASSAGE LATE MONDAY NIGHT OR AROUND DAYBREAK ON
TUESDAY.
UNTIL THEN...TEMPERATURES THROUGH THE ENTIRE SHORT TERM PERIOD WILL
CONTINUE TO REMAIN CLOSE TO OR EXCEED RECORD LEVELS...BOTH FOR VERY
HIGH NIGHTTIME LOWS...WHICH WILL REMAIN NEARLY 30F ABOVE SEASONAL
NORMALS AND AROUND 15F HIGHER THAN WHAT WOULD NORMALLY BE EXPECTED
FOR A DAYTIME HIGH TEMPERATURE...WITH DAYTIME HIGH TEMPERATURES AT
LEAST 20F ABOVE SEASONAL NORMALS...AGAIN BREAKING RECORDS. REFER TO
CLIMATOLOGICAL SECTION FOR SPECIFICS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 140 PM EST FRIDAY...
TUESDAY WILL FEATURE SOME LEFT OVER RAIN SHOWERS BEFORE THE FRONT
CAN MAKE ITS PUSH THROUGH THE REGION. WEDNESDAY LOOKS TO BE A DRIER
DAY EARLY BEFORE THE NEXT SYSTEM MOVES UP AND BRINGS ADDITIONAL RAIN
SHOWERS LATE WEDNESDAY NIGHT AND INTO THE DAY ON THURSDAY. TEMPS
TUESDAY THROUGH THURSDAY WILL REMAIN ABOVE NORMAL. TUESDAY LOOKS TO
BE THE WARMEST DAY OF THE PERIOD WITH HIGHS IN THE UPPER 50S TO
LOWER 60S...AND THEN ABOUT 5 DEGREES COOLER ON WEDNESDAY AND
THURSDAY.
A BIG PATTERN SHIFT SETS UP FOR LATE IN THE WEEK AS A
STRONG RIDGE SETS UP OUT WEST AND A TROUGH BEGINS TO DIG IN ACROSS
THE EASTERN HALF OF THE COUNTRY BRINGING MUCH COLDER AIR TO THE
REGION. SEVERAL WAVES OF ENERGY WILL RIPPLE ACROSS THROUGH NEXT
WEEKEND. MOISTURE LOOKS LIMITED BUT COULD BE ENOUGH TO SQUEAK OUT
SOME NORTHWEST FLOW PRECIP ACROSS THE WESTERN UPSLOPE
AREAS...OTHERWISE THE REST OF THE REGION LOOKS TO BE COOLER AND DRY
FOR NEXT WEEKEND.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1243 PM EST FRIDAY...
A BRIEF PERIOD OF VFR CONDITIONS THIS AFTERNOON WILL LOWER TO
MVFR/IFR CONDITIONS IN CONVECTION LATER THIS AFTERNOON. IFR/LIFR
CONDITIONS WILL BECOME WIDESPREAD THIS EVENING INTO TONIGHT WITH
LOW CLOUDS...FOG AND RAIN.
AN AREA OF LIGHT SHOWERS WILL LIFT NORTHEAST ACROSS EASTERN
PORTIONS OF FORECAST AREA DURING THE NEXT COUPLE OF HOURS.
THEN...HEAVIER SHOWERS AND EMBEDDED THUNDERSTORMS WILL
SPREAD EAST ACROSS THE REGION LATER THIS AFTERNOON INTO TONIGHT.
KLWB AND KBLF WOULD BE THE TAF SITES WITH THE BEST CHANCE OF
THUNDERSTORM.
AFTER SUNSET CONDITIONS WILL DETERIORATE BACK TO LIFR CEILINGS.
AREAS OF LOW CLOUDS AND FOG WILL LIFT BY MID MORNING SATURDAY.
MVFR/IFR CONDITIONS WITH SCATTERED SHOWERS WILL CONTINUE
SATURDAY.
MEDIUM CONFIDENCE IN VISIBILITIES...CEILINGS AND WINDS DURING THE
TAF PERIOD.
.EXTENDED AVIATION DISCUSSION...
THE CHANCE OF SHOWERS AND SUB-VFR CONDITIONS WILL CONTINUE INTO
THE WEEKEND...BUT OVERALL LESS LIKELY TO PERSIST IN THE IFR OR
WORSE VALUES AS ATMOSPHERE WILL BE A LITTLE BETTER MIXED AND
FREQUENCY OF SHOWERS MUCH LESS WITH NO KEY FEATURES TO HELP LIFT
THE MOIST ATMOSPHERE.
BEYOND THIS WEEKEND...MODELS CONTINUE TO VARY BUT SHOWING BETTER
THREAT OF SHOWERS AGAIN BY LATE MONDAY INTO TUESDAY WITH VFR TO
IFR AT TIMES.
&&
.HYDROLOGY...
AS OF 600 PM EST FRIDAY...
FLASH FLOOD WATCH UNTIL MIDNIGHT. HIGHEST THREAT LOOKS TO BE
SHIFTED MORE TOWARD THE MOUNTAIN EMPIRE SOUTHWARD INTO NW NC. PRECIPITABLE
WATER VALUES REMAIN UNSEASONABLY HIGH WITH A DEEP LAYER OF THE
ATMOSPHERE SUPPORTING EFFICIENT WARM RAIN PROCESSES. SO SIMILAR TO
THURSDAY...RAINFALL RATES MAY REACH ONE TO TWO INCHES PER HOUR.
FOR MAINSTEM RIVERS... FLOOD WARNINGS REMAIN IN EFFECT ALONG THE
DAN RIVER FROM DANVILLE THROUGH SOUTH BOSTON.
ON THE ROANOKE RIVER A FLOOD WARNING CONTINUES FOR RANDOLPH. AT
RANDOLPH...THE RIVER WAS EXPERIENCING MODERATE FLOODING BUT THE
RIVER IS FALLING.
&&
.CLIMATE...
AS OF 230 PM EST FRIDAY...
WITH THE CONTINUING VERY WARM AIRMASS IN PLACE FOR THE NEXT
SEVERAL DAYS... MANY DAILY MAX TEMPERATURE RECORDS AS WELL AS HIGH
MIN TEMPERATURE RECORDS ARE LIKELY TO BE SET. FOR REFERENCE...HERE
ARE RECORDS FOR OUR CLIMATE STATIONS FOR THE NEXT SEVERAL DAYS.
SATURDAY 12/26/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 62 1987 -3 1983 16 1977 55 1982
KDAN 75 1982 2 1983 18 1983 57 1964
KLYH 72 1922 1 1983 22 1914 58 1964
KROA 70 1964 3 1980 23 1985 56 1982
KRNK 64 1982 -8 1985 9 1983 50 1982
SUNDAY 12/27/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 69 2008 9 1977 20 2010 52 1982
KDAN 77 1982 6 1983 27 1985 54 1964
KLYH 71 1971 0 1914 21 1925 50 1940
KROA 69 1984 -3 1914 25 1935 52 1940
KRNK 67 2008 -6 1985 20 1985 52 1964
MONDAY 12/28/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 67 1984 4 1977 20 1995 53 1984
KDAN 72 1971 13 1966 28 1950 54 2008
KLYH 76 1984 6 1977 26 1950 51 1959
KROA 75 1984 4 1925 25 1925 51 1984
KRNK 66 1984 6 1977 28 1995 42 1959
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EST TONIGHT FOR VAZ007-
009>020-022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EST TONIGHT FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH UNTIL MIDNIGHT EST TONIGHT FOR WVZ042>044-
507-508.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK/WP
SHORT TERM...WERT
LONG TERM...CF
AVIATION...AMS/KK
HYDROLOGY...AMS/KK/WP
CLIMATE...AMS/RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
240 PM EST FRI DEC 25 2015
.SYNOPSIS...
A FRONTAL BOUNDARY WILL STALL OVER THE MID ATLANTIC REGION TONIGHT
AND LIFT NORTHWARD ON SATURDAY. SUNDAY AND MONDAY...A SERIES OF
STRONG LOW PRESSURE SYSTEMS WILL TRACK FROM THE SOUTHERN PLAINS TO
THE GREAT LAKES.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 240 PM EST FRIDAY...
A FRONTAL BOUNDARY WITH SEVERAL WAVES OF LOW PRESSURE STALLS THIS
EVENING INTO TONIGHT ACROSS THE REGION AND THEN PUSHES NORTHWARD ON
SATURDAY. AN AREA OF LOW PRESSURE IN WEST VIRGINIA THIS AFTERNOON
WILL LIFT NORTHEAST AND REACH THE JERSEY SHORE TONIGHT. A SECOND
AREA OF LOW PRESSURE WILL ROTATE NORTHWARD ALONG THE BOUNDARY
TONIGHT WITH ADDITIONAL SHOWERS. THE DAY 1 EXCESSIVE RAINFALL PLACED
THE WESTERN HALF OF THE FORECAST AREA UNDER A SLIGHT RISK. CURRENT
WSR-88D SHOWED A BAND OF SHOWERS AND THUNDERSTORMS FROM WEST
VIRGINIA SOUTHWARD TO EASTERN AND MIDDLE TENNESSEE. ELECTED TO
EXTEND OUR FLASH FLOOD WATCH UNTIL MIDNIGHT...GIVEN THAT WITH RECENT
RAINFALL AND LOW FFG...IT WILL NOT TAKE MUCH TO PRODUCE FLASH
FLOODING IN THE REGION. DAY ONE CONVECTIVE OUTLOOK STILL SHOWS A
MRGL THREAT FOR SEVERE...WITH THE POTENTIAL FOR LOCALLY STRONG WIND
GUSTS INTO THIS EVENING. MCS OVER EASTERN KENTUCKY/TENNESSEE IS
PROGGED TO SPREAD EAST OF THE BLUE RIDGE LATER TODAY...WHERE IT WILL
INTERACT WITH A SEASONABLY WARM AND MOIST AIR MASS. SEVERE THREAT
WILL BE HINDER BY POOR WEAK INSTABILITY...AND POOR LAPSE RATES OVER
OUR AREA. THE HIRESW-ARW...RNK WRF AND HRRR TAKE THE AREA OF
CONVECTION TO OUR WEST AND MOVED IT EASTWARD ACROSS OUR FORECAST
AREA THIS AFTERNOON INTO TONIGHT. THE GFS...NAM AND ECMWF DROP THE
CONVECTION WITH THE FRONTAL BOUNDARY SOUTH THROUGH 00Z TO 03Z THIS
EVENING. IN ANY CASE...PLAYED THE HIGHEST POPS ACROSS THE
NORTHWEST...WITH THE LOWEST ALONG THE EASTERN SLOPES OF THE
SOUTHERN BLUE RIDGE MOUNTAINS. IT WILL BE ANOTHER MILD
NIGHT...WITH LOW TEMPERATURES FROM THE LOWER 50S IN THE NORTHERN
MOUNTAINS TO THE LOWER 60S IN THE PIEDMONT.
OUR UNSEASONABLY WARM AND UNSETTLED PATTERN WILL CONTINUE SATURDAY.
THE UPPER PATTERN WILL FEATURE AN EASTERN RIDGE AS A CLOSED LOW
DEVELOPS OVER TEXAS AND THEN EJECTS INTO THE OHIO VALLEY. THIS WILL
PUSH THE FRONTAL BOUNDARY...WHICH HAS BEEN WAVERING AROUND THE
REGION FOR THE LAST SEVERAL DAYS...BACK TO THE NORTH AND KEEP THE
BEST CHANCES FOR PRECIPITATION...MAINLY NORTH OF ROUTE 460. HIGH
TEMPERATURES SATURDAY WILL RANGE FROM THE LOWER 60S IN THE NORTHERN
MOUNTAINS TO LOWER AND MID 70S IN THE PIEDMONT.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
AS OF 130 PM EST FRIDAY...
RELATIVE BREAK IN THE WET WEATHER EXPECTED OVER THE BLACKSBURG
FORECAST AREA FROM SATURDAY NIGHT THROUGH AT LEAST EARLY SUNDAY
NIGHT WITH ONLY SPOTTY WARM SECTOR SHOWERS POSSIBLE AS VERY STRONG
TROPICAL RIDGE OF HIGH PRESSURE OFF THE SE COAST OF THE NATION
DEFLECTS NORTHERN STREAM ENERGY AND MORE ROBUST PRECIPITATION FIELDS
CLOSER TO BAROCLINIC ZONE TO THE NORTH OF THE AREA. ANY RESIDUAL
COOL WEDGE ACROSS NORTHEASTERN PORTION OF THE FORECAST AREA SHOULD
RETREAT NORTH AND OUT OF THE AREA BY OR SHORTLY AFTER DAYBREAK ON
SUNDAY AS SE COASTAL RIDGE STRENGTHENS.
HOWEVER...SITUATION WILL BEGIN TO CHANGE LATER SUNDAY NIGHT INTO
MONDAY AS YET ANOTHER...AND THIS TIME STRONGER NORTHERN STREAM WAVE
MOVES EAST THROUGH THE GREAT LAKES AND NEW ENGLAND...SUPPORTING
SOUTHEASTWARD PUSH OF COOLER HIGH PRESSURE INTO SOUTHEASTERN
CANADA...WHICH THEN RIDGES SOUTHWEST INTO THE MID ATLANTIC REGION
MONDAY AFTERNOON INTO MONDAY NIGHT. MEANWHILE...YET ANOTHER
FORMIDABLE LOW LATITUDE CLOSED LOW WILL DRIFT NORTHEAST ON THE
WESTERN PERIPHERY OF THE UPPER RIDGE ALONG THE SE COAST...GRADUALLY
LIFTING AND FILLING AS IT MOVES UP THROUGH THE MS/TN/OH VALLEYS.
APPROACH OF THE WESTERN SYSTEM...AND MOVEMENT OF COOL SURFACE HIGH
PRESSURE TO AN OFFSHORE POSITION TO OUR NORTHEAST WILL RESULT IN
SLOWLY VEERING LOWER TROPOSPHERIC WINDS BACK INTO AN UPSLOPE
COMPONENT ON MONDAY...WHICH SHOULD BEGIN THE NEXT ROUND OF
WIDESPREAD PRECIPITATION FOR THE REGION. PRECIPITATION WILL
INITIALLY BE CONFINED TO LIGHT RAIN AND DRIZZLE ACROSS THE EASTERN
FLANKS OF THE APPALACHIANS LATE SUNDAY NIGHT INTO EARLY MONDAY AS
UPSLOPE COMPONENT INCREASES...BUT THEN EXPAND TO A WIDESPREAD
COVERAGE ACROSS THE ENTIRE FORECAST AREA MONDAY AFTERNOON INTO
MONDAY NIGHT AS UPWARD VERTICAL MOTION FIELDS INTENSIFY AS A RESULT
OF INCREASING WARM MOIST ADVECTION AND APPROACH OF RIGHT ENTRANCE
REGION OF UPPER JET MAXIMA.
WITH GROUND CONDITIONS ALREADY SATURATED...AND WATER LEVELS IN AREA
STREAMS/CREEKS AND RIVERS ALREADY RUNNING HIGH FROM RECENT RAINS...
THREAT FOR ADDITIONAL FLOODING/FLASH FLOODING WILL AGAIN EXIST FROM
MONDAY AFTERNOON INTO MONDAY NIGHT UNTIL CHANGE OF AIRMASS OCCURS
WITH COLD FRONTAL PASSAGE LATE MONDAY NIGHT OR AROUND DAYBREAK ON
TUESDAY.
UNTIL THEN...TEMPERATURES THROUGH THE ENTIRE SHORT TERM PERIOD WILL
CONTINUE TO REMAIN CLOSE TO OR EXCEED RECORD LEVELS...BOTH FOR VERY
HIGH NIGHTTIME LOWS...WHICH WILL REMAIN NEARLY 30F ABOVE SEASONAL
NORMALS AND AROUND 15F HIGHER THAN WHAT WOULD NORMALLY BE EXPECTED
FOR A DAYTIME HIGH TEMPERATURE...WITH DAYTIME HIGH TEMPERATURES AT
LEAST 20F ABOVE SEASONAL NORMALS...AGAIN BREAKING RECORDS. REFER TO
CLIMATOLOGICAL SECTION FOR SPECIFICS.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 140 PM EST FRIDAY...
TUESDAY WILL FEATURE SOME LEFT OVER RAIN SHOWERS BEFORE THE FRONT
CAN MAKE ITS PUSH THROUGH THE REGION. WEDNESDAY LOOKS TO BE A DRIER
DAY EARLY BEFORE THE NEXT SYSTEM MOVES UP AND BRINGS ADDITIONAL RAIN
SHOWERS LATE WEDNESDAY NIGHT AND INTO THE DAY ON THURSDAY. TEMPS
TUESDAY THROUGH THURSDAY WILL REMAIN ABOVE NORMAL. TUESDAY LOOKS TO
BE THE WARMEST DAY OF THE PERIOD WITH HIGHS IN THE UPPER 50S TO
LOWER 60S...AND THEN ABOUT 5 DEGREES COOLER ON WEDNESDAY AND
THURSDAY.
A BIG PATTERN SHIFT SETS UP FOR LATE IN THE WEEK AS A
STRONG RIDGE SETS UP OUT WEST AND A TROUGH BEGINS TO DIG IN ACROSS
THE EASTERN HALF OF THE COUNTRY BRINGING MUCH COLDER AIR TO THE
REGION. SEVERAL WAVES OF ENERGY WILL RIPPLE ACROSS THROUGH NEXT
WEEKEND. MOISTURE LOOKS LIMITED BUT COULD BE ENOUGH TO SQUEAK OUT
SOME NORTHWEST FLOW PRECIP ACROSS THE WESTERN UPSLOPE
AREAS...OTHERWISE THE REST OF THE REGION LOOKS TO BE COOLER AND DRY
FOR NEXT WEEKEND.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1243 PM EST FRIDAY...
A BREIF PERIOD OF VFR CONDITIONS THIS AFTERNOON WILL LOWER TO
MVFR/IFR CONDITIONS IN CONVECTION LATER THIS AFTERNOON. IFR/LIFR
CONDITIONS WILL BECOME WIDESPREAD THIS EVENING INTO TONIGHT WITH
LOW CLOUDS...FOG AND RAIN.
AN AREA OF LIGHT SHOWERS WILL LIFT NORTHEAST ACROSS EASTERN
PORTIONS OF FORECAST AREA DURING THE NEXT COUPLE OF HOURS.
THEN...HEAVIER SHOWERS AND EMBEDDED THUNDERSTORMS WILL
SPREAD EAST ACROSS THE REGION LATER THIS AFTERNOON INTO TONIGHT.
KLWB AND KBLF WOULD BE THE TAF SITES WITH THE BEST CHANCE OF
THUNDERSTORM.
AFTER SUNSET CONDITIONS WILL DETERIORATE BACK TO LIFR CEILINGS.
AREAS OF LOW CLOUDS AND FOG WILL LIFT BY MID MORNING SATURDAY.
MVFR/IFR CONDITIONS WITH SCATTERED SHOWERS WILL CONTINUE
SATURDAY.
MEDIUM CONFIDENCE IN VISIBILITIES...CEILINGS AND WINDS DURING THE
TAF PERIOD.
.EXTENDED AVIATION DISCUSSION...
THE CHANCE OF SHOWERS AND SUB-VFR CONDITIONS WILL CONTINUE INTO
THE WEEKEND...BUT OVERALL LESS LIKELY TO PERSIST IN THE IFR OR
WORSE VALUES AS ATMOSPHERE WILL BE A LITTLE BETTER MIXED AND
FREQUENCY OF SHOWERS MUCH LESS WITH NO KEY FEATURES TO HELP LIFT
THE MOIST ATMOSPHERE.
BEYOND THIS WEEKEND...MODELS CONTINUE TO VARY BUT SHOWING BETTER
THREAT OF SHOWERS AGAIN BY LATE MONDAY INTO TUESDAY WITH VFR TO
IFR AT TIMES.
&&
.HYDROLOGY...
AS OF 220 PM EST FRIDAY...
EXTENDED FLASH FLOOD WATCH UNTIL MIDNIGHT. HIGHEST THREAT WILL BE
IN THE NORTHWEST HALF OF THE FORECAST AREA. THREE HOUR FLASH FLOOD
GUIDANCE IN THIS REGION WAS GENERALLY LESS THAN 1.5 INCHES.
PRECIPITABLE WATER VALUES REMAIN UNSEASONABLY HIGH WITH A DEEP
LAYER OF THE ATMOSPHERE SUPPORTING EFFICIENT WARM RAIN PROCESSES.
SO SIMILAR TO THURSDAY...RAINFALL RATES MAY REACH ONE TO TWO
INCHES PER HOUR.
FOR MAINSTEM RIVERS... FLOOD WARNINGS REMAIN IN EFFECT ALONG THE
DAN RIVER THROUGH SOUTH BOSTON. AT 1016 AM FRIDAY...WENTWORTH HAS
FALLEN BELOW FLOOD STAGE AND WILL CONTINUE TO SLOWLY FALL.
ON THE ROANOKE RIVER A FLOOD WARNING CONTINUES FOR RANDOLPH. AT
RANDOLPH...THE RIVER WAS EXPERIENCING MODERATE FLOODING AS WAS
STILL RISING AND SHOULD CREST THIS EVENING.
CHARLOTTE AND HALIFAX COUNTY OFFICIALS REPORTED SEVERAL ROADS
REMAINED CLOSED DUE TO FLOODING.
&&
.CLIMATE...
AS OF 230 PM EST FRIDAY...
WITH THE CONTINUING VERY WARM AIRMASS IN PLACE FOR THE NEXT
SEVERAL DAYS... MANY DAILY MAX TEMPERATURE RECORDS AS WELL AS HIGH
MIN TEMPERATURE RECORDS ARE LIKELY TO BE SET. FOR REFERENCE...HERE
ARE RECORDS FOR OUR CLIMATE STATIONS FOR THE NEXT SEVERAL DAYS.
SATURDAY 12/26/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 62 1987 -3 1983 16 1977 55 1982
KDAN 75 1982 2 1983 18 1983 57 1964
KLYH 72 1922 1 1983 22 1914 58 1964
KROA 70 1964 3 1980 23 1985 56 1982
KRNK 64 1982 -8 1985 9 1983 50 1982
SUNDAY 12/27/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 69 2008 9 1977 20 2010 52 1982
KDAN 77 1982 6 1983 27 1985 54 1964
KLYH 71 1971 0 1914 21 1925 50 1940
KROA 69 1984 -3 1914 25 1935 52 1940
KRNK 67 2008 -6 1985 20 1985 52 1964
MONDAY 12/28/2015
SITE MAXT YEAR MINT YEAR LOMAX YEAR HIMIN YEAR
KBLF 67 1984 4 1977 20 1995 53 1984
KDAN 72 1971 13 1966 28 1950 54 2008
KLYH 76 1984 6 1977 26 1950 51 1959
KROA 75 1984 4 1925 25 1925 51 1984
KRNK 66 1984 6 1977 28 1995 42 1959
&&
.EQUIPMENT...
AS OF 220 PM EST FRIDAY...
THE DANVILLE OBSERVATION APPEARS TO BE WORKING CONSISTENTLY
AGAIN...BUT WILL NEED TO BE MONITORED.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...FLASH FLOOD WATCH UNTIL MIDNIGHT EST TONIGHT FOR VAZ007-
009>020-022>024-032>035-043>047-058-059.
NC...FLASH FLOOD WATCH UNTIL MIDNIGHT EST TONIGHT FOR NCZ001>006-
018>020.
WV...FLASH FLOOD WATCH UNTIL MIDNIGHT EST TONIGHT FOR WVZ042>044-
507-508.
&&
$$
SYNOPSIS...AMS/KK
NEAR TERM...KK
SHORT TERM...WERT
LONG TERM...CF
AVIATION...AMS/KK
HYDROLOGY...AMS/KK
CLIMATE...AMS/RCS
EQUIPMENT...RCS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1243 PM EST FRI DEC 25 2015
.SYNOPSIS...
A COLD FRONT EXTENDED ACROSS NEW ENGLAND...THE TENNESSEE VALLEY
AND INTO THE LOWER MISSISSIPPI VALLEY THIS MORNING. THIS FRONT
WILL STALL OVER THE MID ATLANTIC REGION TONIGHT. SUNDAY AND MONDAY
A SERIES OF STRONG LOW PRESSURE SYSTEMS WILL TRACK FROM THE
SOUTHERN PLAINS TO THE GREAT LAKES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1230 PM EST FRIDAY...
MADE SOME MINOR ADJUSTMENTS IN POPS AND TEMPERATURES FOR THIS
AFTERNOON.
AS OF 942 AM EST FRIDAY...
ALLOWED THE DENSE FOG ADVISORY TO EXPIRE AT 9 AM. WIDESPREAD
DENSE FOG HAS ENDED. VISIBILITIES ARE IMPROVING AND TREND WILL
CONTINUE THIS MORNING. AS WINDS INCREASE...THE FOG WILL ERODE OR
MIX OUT.
MODIFIED TEMPERATURES TOWARDS CURRENT OBS AND SHAPED TOWARDS THE
LAV FOR THIS MORNING INTO THIS AFTERNOON. HIGH TEMPERATURES THIS
AFTERNOON WILL UNSEASONABLY WARM WITH READINGS FROM THE LOWER 60S
IN THE MOUNTAINS TO THE MID 70S IN THE PIEDMONT. LEANED POPS
TOWARDS THE HRRR SOLUTION WHICH SEEMED TO CAPTURE THE LATEST WSR-
88D IMAGES AND TRENDS. PLAN TO HOLD WITH CURRENT FLOOD WATCH AND
WAIT TO EXAMINE 12Z MODEL RUN AND HOW CONVECTION DEVELOPS AND
UNFOLDS. INITIAL IMPRESSIONS THAT A EXPANSION OF THE FLOOD WATCH
MAY BE NEED LATER TODAY.
AS OF 630 AM EST FRIDAY...
HAVE ISSUED A DENSE FOG ADVISORY FROM THE ALLEGHANY HIGHLANDS
THROUGH THE ROANOKE AND NEW RIVER VALLEYS INTO NORTHWEST NORTH
CAROLINA.
TWO AREAS OF PRECIPITATION WILL CROSS THROUGH THE FORECAST AREA
TODAY AND TONIGHT. THE FIRST AREA WAS OVER THE SOUTHERN APPALACHIANS
AND WAS ADVANCING NORTHEAST AND WAS JUST ENTERING WATAUGA COUNTY
AT 4AM. THESE SHOWER WILL PASS THROUGH THE COUNTY WARNING AREA
MAINLY BEFORE NOON.
THE NEXT AREA OF PRECIPITATION WAS MOVING INTO WESTERN KENTUCKY AND
TENNESSEE. THIS PRECIPITATION WAS ASSOCIATED WITH A SHORT WAVE AND
LOW PRESSURE ALONG A COLD FRONT OVER THE LOWER MISSISSIPPI VALLEY.
AS THE LOW TRACKS NORTHEAST THE SHOWERS AND ISOLATED THUNDERSTORMS
WILL REACH THE CENTRAL APPALACHIANS THIS AFTERNOON AND EVENING.
MODELS SHOWED SOME DIFFERENCES IN THE LOCATION OF THE AXIS OF
HEAVIEST RAIN. STAYED CLOSE TO WPC FORECAST WITH THE HEAVIEST
RAINFALL EXPECTED NORTHWEST OF A LYNCHBURG TO MARION LINE. HAVE
INCREASED THE PROBABILITY OF PRECIPITATION IN THE NORTHWEST COUNTY
WARNING AREA FOR TODAY AND TONIGHT AND TRIMMED BACK THE PROBABILITY
IN THE SOUTHEAST.
THE SURFACE FRONT WILL BE CLOSE TO...IN NOT JUST INTO...THE NORTHERN
COUNTY WARNING AREA BY TONIGHT. ECMWF/GFS AND NAM ALL BRING THE
FRONT SOUTH OF LYNCHBURG BY EARLY SATURDAY MORNING. THIS WILL
KEEP A MAJORITY OF THE FORECAST AREA IN THE VERY WARM AND MOIST
AIRMASS TODAY AND TONIGHT. FOOTHILLS AND PIEDMONT OF SOUTHERN
VIRGINIA AND NORTHWEST NORTH CAROLINA WERE STILL IN THE UPPER 60S
AT 4AM SO INCREASED MAXIMUM TEMPERATURES INTO THE MID 70S IN THERE
LOCATIONS. OTHERWISE STAYED CLOSE TO GUIDANCE FOR MAXIMUM AND
MINIMUM TEMPERATURES.
&&
.SHORT TERM /SATURDAY THROUGH MONDAY NIGHT/...
AS OF 400 AM EST FRIDAY...
OUR VERY WARM AND UNSETTLED PATTERN WILL CONTINUE THROUGH THE WEEKEND
BEFORE WE START TO SEE ANY SIGNIFICANT CHANGES STARTING MONDAY. THE
UPPER PATTERN WILL CONTINUE TO FEATURE AN EASTERN RIDGE AS A CLOSED LOW
DEVELOPS OVER TEXAS AND THEN EJECTS INTO THE OHIO VALLEY. THIS WILL
PUSH THE OLD FRONTAL BOUNDARY...WHICH HAS BEEN WAVERING AROUND THE
REGION FOR THE LAST SEVERAL DAYS...BACK TO THE NORTH AND KEEP THE BEST
CHANCES FOR PRECIPITATION MAINLY NORTH OF ROUTE 460. SUNDAY WILL SEE
SOME LINGERING LIGHT PRECIPITATION MAINLY ALONG THE BLUE RIDGE BUT AS
THE AFOREMENTIONED CLOSED UPPER LOW STARTS TO EJECT...IT WILL DRIVE A
DEVELOPING SURFACE LOW UP THE MISSISSIPPI VALLEY AND START TO SPREAD
PRECIPITATION INTO THE REGION FROM THE WEST. MEANWHILE A STRONG SURFACE
HIGH WILL MOVE THROUGH SOUTHERN CANADA AND WEDGE DOWN THE EASTERN
SEABOARD. THIS WILL PUSH A BACKDOOR COLD FRONT INTO THE REGION SUNDAY
NIGHT WITH A COLD WEDGE SETTING UP FOR MONDAY WITH A SUBSTANTIAL COOL
DOWN EXPECTED. THE COMBINATION OF A COLD WEDGE OVER THE AREA AND THE
LOW PRESSURE SYSTEM MOVING UP THE MISSISSIPPI VALLEY WILL GET NEXT WEEK
OFF TO A WET START. THE LOW LEVEL WIND FIELD WILL ALSO BE STRENGTHENING
ON MONDAY AND SOME RIDGE TOPS OUTSIDE OF THE WEDGE ALONG THE FAR
WESTERN SLOPES OF THE APPALACHIANS MAY BE LOOKING AT WIND GUSTS OVER 40
MPH.
HIGH TEMPERATURES SATURDAY AND SUNDAY WILL REMAIN NEAR RECORD LEVELS
WITH LOW/MID 70S EAST OF THE BLUE RIDGE AND MID 60S/AROUND 70 TO THE
WEST. HOWEVER TEMPERATURES ON MONDAY IN THE COOL WEDGE WILL ONLY BE IN
THE MID/UPPER 50S TO THE EAST WITH UPPER 40S/LOWER 50S WEST...AND
MONDAY NIGHT LOW TEMPERATURES WILL START TO APPROACH THE FREEZING MARK
FOR THE ALLEGHANY HIGHLANDS. THESE LOWER TEMPERATURES WILL FEEL
SUBSTANTIALLY COOLER BUT ARE STILL WELL ABOVE NORMAL FOR LATE DECEMBER.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 245 PM EST WEDNESDAY...
A SURFACE FRONTAL BOUNDARY DRAPED FROM THE OHIO VALLEY TO THE
SOUTHERN PLAINS WILL MEANDER CLOSE TO THE REGION KEEPING...WITH
THE GREATEST THREAT FOR SHOWERS TUESDAY AS THE FRONT OCCLUDES AND
SLOWLY PUSHES THROUGH OUR REGION AND EVENTUALLY STALLS TO OUR
SOUTHEAST ON WEDNESDAY.
TEMPS BACK OFF TO +5-10C TUESDAY THROUGH THURSDAY BEFORE THE
COLDER AIR ARRIVES FRIDAY.
MODELS TEND TO AGREE THAT THE END OF THE WEEK WILL FEATURE A PUSH
OF MUCH COLDER AND DRIER AIR INTO THE REGION AS A SHORTWAVE DIGS
IN. DIFFERENCES EXIST AS TO HOW DEEP THAT PUSH OF COLDER AIR WILL
BE AND HOW MUCH IF ANY MOISTURE WILL BE AVAILABLE FOR ANY
POTENTIAL UPSLOPE PRECIP/CLOUDS LATE IN THE WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
AS OF 1243 PM EST FRIDAY...
A BREIF PERIOD OF VFR CONDITIONS THIS AFTERNOON WILL LOWER TO
MVFR/IFR CONDITION