Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/14/15
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
243 PM CST SAT DEC 12 2015
.SHORT TERM...TONIGHT THROUGH TUESDAY NIGHT
HAVE CONTINUED TO SEE A MOSTLY CLOUDY DAY AROUND THE STATE
TODAY...WITH ONLY A FEW BREAKS IN THE CLOUDS NOTED ACROSS EXTREME SE
ARKANSAS. BREEZY SE WINDS ARE BEING SEEN AROUND THE STATE...AND
TEMPERATURES WARMED INTO THE LOWER TO MID 70S.
HAVE BEGUN TO SEE A FEW ISOLATED SHOWERS POP UP AROUND THE STATE
THIS AFTERNOON. MODEL SOUNDINGS ARE ACTUALLY SHOWING SURFACE BASED
CAPE VALUES A BIT HIGHER THAN PREVIOUSLY ADVERTISED...HOWEVER SB
CAPE VALUES ARE STILL 500 J/KG OR LESS. LIMITED SB CAPE COMBINED
WITH POOR MID LEVEL LAPSE RATES WILL LIKELY LIMIT THE DEVELOPMENT OF
ANY SEVERE WEATHER TONIGHT.
HIRES MODELS CONTINUE TO SHOW TWO ROUNDS OF HEAVY
PRECIPITATION...WITH THE FIRST ROUND FORECAST FOR TONIGHT.
HOWEVER...BOTH THE HIRES AND MORE COARSE MODELS CONTINUE TO TREND
THE AXIS OF HEAVIEST PRECPITATION FURTHER TO THE WEST. IN FACT THE
PAST FEW RUNS OF THE HRRR HAS MUCH OF ARKANSAS MISSING OUT
COMPLETELY ON THE FIRST ROUND OF HEAVY PRECIPITATION. ALSO OF
CONCERN TONIGHT WILL BE BREEZY CONDITIONS. AT THIS POINT WILL NOT
ISSUE A LAKE WIND ADVISORY...AS WINDS SHOULD BE JUST BELOW LAKE WIND
CRITERIA.
TEMPERATURES WILL BE WARM OVERNIGHT...WITH READINGS DROPPING VERY
LITTLE. MUCH OF THE WESTERN HALF OF THE STATE WILL SEE SUNDAY HIGH
TEMPERATURES OCCUR EARLY SUNDAY MORNING WITH TEMPERATURES FALLING
FOR MUCH OF THE DAY. ACROSS THE EASTERN HALF OF THE
STATE...TEMPERATURE TRENDS WILL BE NEAR DIURNAL AS THIS SYSTEM HAS
SLOWED QUITE A BIT. BEST PRECIPITATION CHANCES FOR CENTRAL AND
EASTERN ARKANSAS WILL LIKELY HOLD OFF UNTIL THE SUNDAY AFTERNOON
HOURS WITH PRECIPITATION COMING TO AN END DURING THE OVERNIGHT
HOURS. PRECIPITATION CHANCES WILL LINGER ACROSS NORTHERN ARKANSAS
EARLY MONDAY AS THE UPPER LOW SWINGS THROUGH THE AREA.
BEHIND THIS SYSTEM...TEMPERATURES WILL FALL BUT STILL REMAIN ABOVE
NORMAL. PRECIPITATION CHANCES WILL RETURN TO THE FORECAST TO ROUND
OUT THE SHORT TERM AS THE NEXT COLD FRONT APPROACHES ARKANSAS.
&&
.LONG TERM...WEDNESDAY THROUGH SATURDAY
A NEW STORM SYS WL BE PASSING WELL N OF AR ON WED...WITH A SWD
TRAILING CDFNT PUSHING E OF THE FA. A FEW SHOWERS WL LINGER OVR SERN
AR EARLY WED...OTHERWISE COOLER AND DRIER CONDS WL PREVAIL.
A WEAK UPR LVL SYSTEM WL TRACK EWD ACRS THE AREA THU NGT AND EARLY
FRI...WITH JUST SOME MID AND HIGH CLOUDS ACCOMPANYING IT. TEMPS WL
BEGIN TO SLOLY MODERATE HEADING INTO NEXT WEEKEND AS HIGH PRES
SHIFTS EWD...WITH LGT S/SWLY WINDS RETURNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 65 70 46 60 / 50 100 60 0
CAMDEN AR 67 69 44 66 / 60 100 20 0
HARRISON AR 63 65 42 57 / 90 100 40 10
HOT SPRINGS AR 67 68 44 62 / 80 100 20 0
LITTLE ROCK AR 66 69 45 63 / 50 90 40 0
MONTICELLO AR 68 72 48 64 / 30 100 40 0
MOUNT IDA AR 66 68 42 63 / 90 100 20 0
MOUNTAIN HOME AR 63 69 44 60 / 80 100 50 10
NEWPORT AR 64 71 47 60 / 30 100 60 10
PINE BLUFF AR 66 71 46 63 / 40 100 40 0
RUSSELLVILLE AR 66 67 43 61 / 90 100 30 0
SEARCY AR 65 70 44 60 / 40 100 50 0
STUTTGART AR 66 71 47 62 / 30 100 50 0
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...65 / LONG TERM...44
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
856 AM MST SAT DEC 12 2015
.SYNOPSIS...
LOW PRESSURE WILL CONTINUE TO SLOWLY MOVE THROUGH THE REGION
TODAY...RESULTING IN MOUNTAIN RAIN AND SNOW SHOWERS AND SUBSTANTIALLY
COOLER TEMPERATURES. ANOTHER FAST MOVING STORM SYSTEM WILL MOVE
THROUGH THE AREA ON MONDAY...USHERING IN ANOTHER ROUND OF COLD TEMPS
WHICH WILL LAST MUCH OF THE UPCOMING WEEK. SOME OF THE COLDEST LOW
TEMPERATURES OF THE SEASON ARE ANTICIPATED BY THE MIDDLE OF NEXT
WEEK.
&&
.DISCUSSION...
MID MORNING WATER VAPOR IMAGERY REVEALS LOW PRESSURE OVER SOUTHERN
ARIZONA WITH QUITE A BIT OF MOISTURE OVER THE ARIZONA/NEW MEXICO
BORDER AND POINTS EAST. WRAP-AROUND/DEFORMATION RAIN AND SNOW SHOWERS
ARE NOTED ON RADAR EAST OF PHOENIX THIS MORNING AND AT LEAST A FEW
SPOTS ABOVE 4500 FT HAVE SEEN MINOR ACCUMULATIONS EAST/SOUTH OF
GLOBE. RAIN HAS CEASED FOR THE MOST PART ACROSS THE LOWER DESERTS
/SANS A FEW SHOWERS AROUND SUPERIOR/ AND VIS IMAGERY ALONG WITH
WEBCAMS SUGGEST RAPID CLEARING IS MAKING ITS WAY INTO THE WEST VALLEY
AS OF 1545Z.
OPERATIONAL GLOBAL MODELS...LOCAL WRFS...AND SEVERAL RECENT RUNS OF
THE HRRR CONTINUE TO SHOW PRECIPITATION OVER THE MOUNTAINS NORTH/EAST
OF PHOENIX THROUGH AT LEAST MID AFTERNOON AS THE UPPER LEVEL
CIRCULATION SLIDES THROUGH THE AREA. DRY ADVECTION ACROSS THE WESTERN
2/3RDS OF THE FORECAST AREA WILL RESULT IN NEAR-ZERO CHANCES OF
PRECIPITATION FOR THE REST OF THE DAY /INCLUDING FROM PHOENIX
WESTWARD/...BUT THE MOUNTAINS EAST OF TOWN WILL SEE AT LEAST 60-70
PERCENT CHANCES THROUGH MID AFTERNOON. WITH SNOW LEVELS ALREADY
AROUND 5000FT AND OBSERVED SNOWFALL AROUND THIS ELEVATION...WILL NOT
BE MAKING ANY ADJUSTMENTS TO THE INHERITED WINTER WEATHER ADVISORY.
WHILE THERE COULD BE A STRAY RAIN OR SNOW SHOWER AT THE CONCLUSION
OF THE ADVISORY PERIOD...DRY ADVECTION WILL RAPIDLY PUT THE BRAKES ON
ANY LINGERING PRECIPITATION AFTER 00Z.
TEMPS LOOK IN GOOD SHAPE. BLENDED BIAS CORRECTED AND RAW GUIDANCE ALL
POINTING AT HIGHS BETWEEN 58-61 IN THE PHOENIX AREA AND IN THE UPPER
60S ACROSS SOUTHWEST ARIZONA AND SOUTHEAST CALIFORNIA. ASIDE FROM
MINOR ADJUSTMENTS BASED ON OBSERVATIONAL TRENDS...NO CHANGES
NECESSARY TO TEMPERATURES.
&&
.PREVIOUS DISCUSSION...
SUNDAY...
A FAST MOVING HIGH PRESSURE SYSTEM WILL TRANSITION THROUGH
THE REGION AHEAD OF ANOTHER STRONG AND COLD PACIFIC WEATHER SYSTEM
FOR MONDAY. CLEAR SKIES AND COOL TEMPERATURES ARE FORECAST SUNDAY.
MONDAY...
ANOTHER STRONG PACIFIC WEATHER SYSTEM WILL MOVE INTO THE REGION
MONDAY MORNING. ALTHOUGH MOST DYNAMICS/UPPER LEVEL FORCING
WILL OCCUR OVER CENTRAL AND NORTHERN AZ MONDAY MORNING...A MOISTURE
RICH FRONTAL BAND WITH PRECIP WILL TRANSITION FIRST THROUGH
SOUTHEAST CA/COLORADO RIVER VALLEY LATE SUNDAY NIGHT...THEN
ACROSS SOUTH CENTRAL AZ INCLUDING PHOENIX MONDAY MORNING AND
AFTERNOON. THE SNOW LEVEL ON MONDAY WILL FALL TO BETWEEN 4000-4500
FEET...WITH LIGHT ACCUMULATION...HOWEVER THE REAL STORY IS MUCH
COLDER AND DRIER AIR FOLLOWING ON TUESDAY AND WEDNESDAY FOR
POSSIBLE NIGHT-TIME FREEZE WARNINGS.
TUESDAY AND WEDNESDAY...
A MUCH COLDER AND DRIER AIRMASS WILL SETTLE OVER THE REGION BEHIND
MONDAYS FRONTAL SYSTEM. MORNING TEMPERATURES ON THE LOWER DESERTS
TUESDAY AND WEDNESDAY COULD DROP INTO THE LOWER 20S TO MIDDLE 30S.
FREEZE WARNINGS MAY BE POSTED.
THURSDAY THROUGH SATURDAY...
EXCEPT FOR PERIOD OF HIGH CLOUDS...DRY NORTHWEST FLOW AND WARMER
TEMPERATURES ALOFT WILL START A WARMING TREND. CONSIDERABLE HIGH
CLOUDS AT TIMES SHOULD SERVE TO KEEP NIGHT TIME TEMPERATURES A BIT
WARMER.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
LINGERING SCT TO BKN CIGS AT AROUND 6K FEET EXPECTED INTO THIS
AFTERNOON WITH VERY LITTLE CHANCE OF ANY SHOWERS AFFECTING PHOENIX
TERMINALS. SKIES WILL CLEAR OUT AFTER SUNSET THIS EVENING. WINDS WILL
BE MOSTLY LIGHT AND SOMEWHAT VARIABLE THIS MORNING...TURNING
SOUTHWESTERLY AND BECOMING BREEZY AT TIMES THIS AFTERNOON. WINDS WILL
DIMINISH THIS EVENING AND EVENTUALLY SHIFT OUT OF THE EAST BY AROUND
MIDNIGHT.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
SOME LINGERING CIGS AT KBLH THIS MORNING BEFORE SKIES CLEAR OUT BY
AROUND NOON TODAY. WINDS WILL BE GUSTY AT TIMES DURING THE DAYTIME
HOURS AND MAINLY OUT OF THE NORTHWEST. GUSTS WILL APPROACH 25-30 KTS
AT KBLH AND CLOSER TO 20 KTS AT KIPL BEFORE WINDS GRADUALLY DIMINISH
LATER THIS EVENING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
MONDAY THROUGH FRIDAY...
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THURSDAY WITH A
GRADUAL WARM UP COMMENCING FRIDAY. A DEEP LOW PRESSURE TROUGH WILL
AFFECT THE DESERT SOUTHWEST THROUGH MUCH OF NEXT WEEK BEFORE EXITING
LATE IN THE WEEK. THIS WILL BRING A CHANCE OF SHOWERS TO THE DESERTS ON
MONDAY WITH RAIN OR SNOW SHOWERS OVER HIGHER TERRAIN LOCATIONS.
FAIRLY MOIST CONDITIONS ON MONDAY WILL GIVE WAY TO DRYING STARTING
TUESDAY AS MINIMUM HUMIDITIES DROP INTO A 15 TO 30 PERCENT RANGE FOR
THE REST OF THE WEEK. GUSTY NORTHWESTERLY WINDS ARE LIKELY ON MONDAY
AND TUESDAY...ESPECIALLY AFFECTING THE LOWER COLORADO RIVER VALLEY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR AZZ024.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/VASQUEZ
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1042 PM MST FRI DEC 11 2015
.UPDATE...UPDATED AVIATION DISCUSSION.
&&
.SYNOPSIS...
A STRONG PACIFIC LOW PRESSURE SYSTEM AND COLD FRONT WILL MOVE
THROUGH THE REGION TONIGHT AND SATURDAY...GENERATING COOLER AND
WINDY CONDITIONS. A CHANCE OF SHOWERS ARE ALSO FORECAST MAINLY OVER
PORTIONS OF SOUTH CENTRAL ARIZONA FROM THIS EVENING THROUGH AT LEAST
MIDDAY ON SATURDAY...WITH ACCUMULATING SNOW POSSIBLE ABOVE 5000 FEET
OVER THE HIGHER TERRAIN EAST OF PHOENIX. CLEAR AND COLDER WEATHER IS
THEN EXPECTED SUNDAY...WITH ANOTHER COLD FRONT FORECAST TO MOVE INTO
THE REGION ON MONDAY. A MUCH COLDER AIRMASS IS FORECAST TO SETTLE
OVER THE REGION FROM TUESDAY INTO THURSDAY...POSSIBLY GENERATING
SOME OF THE COLDEST LOW TEMPERATURES SO FAR THIS SEASON.
&&
.DISCUSSION...
LATEST MESOANALYSIS SHOWS THE MID-TROPOSPHERIC TROUGH AXIS ACROSS THE
IMPERIAL VALLEY BUT PROGRESSING STEADILY EASTWARD. TWELVE-HOUR HEIGHT
FALLS OF NEARLY 180 M HAVE BEEN OBSERVED ACROSS THE NORTHERN BAJA
PENINSULA. THE BREEZY CONDITIONS WERE SLOW TO MATERIALIZE BEHIND THE
COLD FRONT THAT MOVED THROUGH CENTRAL AZ THIS AFTERNOON...THOUGH
WINDS HAVE PICKED UP OVER THE PAST FEW HOURS. MEANWHILE...AREAS OF
LIGHT PRECIPITATION ARE FILLING IN ACROSS CENTRAL AZ IN RESPONSE TO
STRONG FORCING FOR ASCENT ASSOCIATED WITH WELL-DEFINED PVA ACROSS THE
LOWER CO RIVER VALLEY.
HI-RES GUIDANCE INCLUDING LATEST RUNS OF THE HRRR CONTINUE TO
INDICATE THAT THE BEST CHANCE OF PRECIPITATION WILL BE ACROSS
NORTHERN MARICOPA COUNTY AND EAST OF PHOENIX IN THE HIGHER TERRAIN OF
GILA COUNTY THROUGH SATURDAY MORNING. QPF WAS INCREASED THIS EVENING
FOR THE 06-12Z PERIOD ACROSS THE HIGHER ELEVATIONS BASED ON THE
LATEST MODEL CONSENSUS. A FEW INCHES OF SNOW ARE LIKELY ABOVE 5K FT
AND A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THESE AREAS.
LATEST SPC GUIDANCE ALSO SUGGESTS THAT AN ISOLATED LIGHTNING STRIKE
IS POSSIBLE IN THE STRONGEST CELLS.
.PREVIOUS DISCUSSION...
TONIGHT THROUGH SUNDAY...
A STRONG...AND COLD PACIFIC TROF CONTINUES TO APPROACH ARIZONA AT
THIS HOUR...WITH RAINFALL NOW BEING REPORTED ACROSS THE SOUTHERN CA
COASTAL REGIONS...AND ACROSS SOUTHERN NV AND EXTREME NW AZ. AHEAD OF
THE MAIN TROF AXIS...THE SFC COLD FRONT IS NOW MOVING INTO WESTERN
AZ...WITH LOCALLY GUSTY WINDS OCCURRING AT SOME LOCATIONS DURING THE
FRONTAL PASSAGE. ALTHOUGH THIS SYSTEM DOES NOT CONTAIN TOO MUCH
MOISTURE (PWATS MAINLY AOB 0.60 INCH)...THE COMBINATION OF STRONG
DYNAMICS/MAJOR HEIGHT FALLS (24HR 500MB HEIGHT FALLS IN THE 200-250M
RANGE ACROSS SOUTH-CENTRAL AZ) AND STRONG COOLING THROUGH THE COLUMN
IS EXPECTED TO ALLOW THE SYSTEM TO MAXIMIZE THE USE OF ITS AVAILABLE
MOISTURE. IT APPEARS THE BEST CHANCE FOR MEASURABLE PRECIP WILL BE
FROM THIS EVENING THROUGH ABOUT MIDDAY ON SATURDAY...WITH THE NCEP
SREF PLUME MEAN SHOWING TOTAL QPF AMOUNTS RANGING FROM AROUND 0.10
OF AN INCH OVER THE LOWER DESERTS OF SOUTH-CENTRAL AZ UP TO AS MUCH
AS 0.50 OF AN INCH OVER THE HIGHER TERRAIN EAST OF PHOENIX.
ALONG WITH THE RAINFALL...MUCH COLDER AIR MOVING INTO THE REGION IS
EXPECTED TO DROP SNOW LEVELS AOB 5000 FEET BY EARLY SAT
MORNING...WHICH WILL BE EARLY ENOUGH TO ALLOW THE RAIN TO CHANGE TO
SNOW BEFORE IT ENDS...WITH 2-4 INCHES POSSIBLE ABOVE 5000 FEET OVER
SOUTHERN GILA COUNTY. 850MB TEMPS...THAT ARE EXPECTED TO FALL AS LOW
AS 0C...WILL MAKE IT VERY DIFFICULT FOR FOR HIGHS TO GET MUCH ABOVE
60F ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ. SKIES ARE EXPECTED
TO CLEAR SAT NIGHT AS THE MAIN UPPER TROF MOVES OFF TO THE
EAST...WITH LOWS SUNDAY MORNING FALLING INTO THE 30S AT MANY LOWER
DESERT LOCATIONS...WITH TEMPERATURES NEAR...OR JUST BELOW FREEZING
LIKELY AT THE COLDEST LOCATIONS.
MONDAY THROUGH THURSDAY...
ANOTHER...EVEN COLDER AIRMASS IS EXPECTED TO MOVE INTO THE REGION
DURING THIS PERIOD...AS A 2ND UPPER TROF MOVES INTO THE REGION FROM
THE EASTERN GULF OF ALASKA. THIS SYSTEM WILL BE TAKING A MORE
EASTERLY TRACK THAN THE ONE THAT WILL BE AFFECTING US OVER THE
WEEKEND...WHICH WILL ALLOW IT TO TAP VERY COLD AIR THAT IS NOW
PARKED OVER ALASKA/NW CANADA. CURRENT EURO AND GFS FORECASTS...AND
MOST OF THEIR MEMBERS ARE IN VERY GOOD AGREEMENT ON THE TIMING AND
INTENSITY OF THIS UPCOMING COLD SNAP. BOTH THE EURO AND GFS
OPERATIONAL RUNS DROP 700MB TEMPS INTO THE -10C TO -13C RANGE ACROSS
OUR CWA BY MONDAY EVENING...THEN HOLD IT IN THIS RANGE THROUGH EARLY
WED MORNING BEFORE TEMPERATURES GRADUALLY MODERATE INTO THURSDAY.
THE COMBINATION OF THE VERY COLD AIR ALOFT AND A DRY AIRMASS (SFC
DEWPOINTS IN THE TEENS AND LOW 20S) WILL ALLOW MANY LOWER DESERT
LOCATIONS TO SEE LOWS AOB FREEZING ON WED AND THU MORNING...WITH THE
COLDEST LOCATIONS SEEING LOWS WELL DOWN IN THE 20S...WITH FREEZE
WARNINGS LIKELY NEEDED DURING THIS PERIOD. HIGHS DURING THIS PERIOD
WILL ME MOSTLY IN THE MID TO UPPER 50S ACROSS THE LOWER DESERTS.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
A COLD FRONT MOVED THROUGH EARLIER TODAY RESULTING IN SOUTHWESTERLY
BREEZES...LOWERING MID LEVEL CEILINGS AND THE ONSET OF SCATTERED
AREAS OF LIGHT TO MODERATE RAIN AND RAIN SHOWERS. CURRENT RADAR
INDICATES MOSTLY LIGHT RAIN AND RAIN SHOWERS FILLING IN AND MOVING
NORTHEAST. ALONG WITH THE RAIN EXPECT SOME OVERNIGHT BREEZINESS AND
CEILINGS NEAR 050. BY MID MORNING EXPECT CEILINGS TO IMPROVE TO MID
LEVELS WITH WEST AND SOUTHWESTERLY BREEZES INCREASING WITH GUSTS TO
ABOUT 20 KNOTS DURING THE AFTERNOON. SKIES WILL BECOME MOSTLY CLEAR
BY EVENING WITH LIGHT WEST AND SOUTHWESTERLY WINDS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
AS HIGH PRESSURE BUILDS IN FROM THE NORTHWEST DURING THE PERIOD
EXPECT LINGERING OVERNIGHT SOUTHWESTERLY BREEZES IN IMPERIAL AND
MOSTLY NORTHWESTERLY BREEZES AT BLYTHE. BY MIDDAY IT WILL BECOME
VERY WINDY WITH NORTHWESTERLY WIND GUSTS TO THE MID 20S WITH SKIES
REMAINING CLEAR.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE PERIOD AS A
COUPLE OF LOW PRESSURE TROUGHS AFFECT THE REGION. A CHANCE OF
SHOWERS TO MAINLY HIGHER TERRAIN LOCATIONS NORTH AND EAST OF PHOENIX
IS POSSIBLE ON MONDAY WITH EVERY OTHER DAY STAYING PRECIP FREE. THE
COOL TEMPERATURES WILL ALLOW FOR HIGHER HUMIDITIES WITH MINIMUM
AFTERNOON VALUES ONLY FALLING INTO A 20 TO 40 PERCENT RANGE. GUSTY
NORTHWESTERLY WINDS ARE LIKELY ON MONDAY AND TUESDAY...ESPECIALLY
AFFECTING THE LOWER COLORADO RIVER VALLEY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...WINTER WEATHER ADVISORY UNTIL NOON MST SATURDAY FOR AZZ024.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...SAWTELLE
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS TUCSON AZ
945 PM MST FRI DEC 11 2015
.SYNOPSIS...SHOWERS AND MOUNTAIN SNOW SHOWERS WILL CONTINUE ACROSS
SOUTHEAST ARIZONA INTO SATURDAY. MUCH COLDER TEMPERATURES WILL ALSO
OCCUR THIS WEEKEND. ANOTHER SYSTEM WILL BRING A FEW VALLEY RAIN AND
MOUNTAIN SNOW SHOWERS MONDAY AND MONDAY NIGHT WITH DRY CONDITIONS
RETURNING BY MIDWEEK. TEMPERATURES WILL REMAIN WELL BELOW AVERAGE
MUCH OF THE UPCOMING WEEK.
&&
.DISCUSSION...VALLEY SHOWERS AND MOUNTAINS SNOW SHOWERS HAVE BEEN ON
THE INCREASE THIS EVENING. RAINFALL AMOUNTS WEST OF TUCSON HAVE
GENERALLY BEEN LESS THAN 0.10" ALTHOUGH THERE ARE LOCALIZED SPOTS UP
TO 0.20". BASED ON RAWS DATA THE SNOW LEVEL IS SOMEWHERE BETWEEN
8500 AND 9000 FEET. CAMERA NEAR MT LEMMON HAS SHOWED SOME MINOR SNOW
ACCUMULATION. A LIGHTING STRIKE OCCURRED NEAR KITT PEAK EARLIER IN
THE EVENING. THE HRRR RUNS SINCE LATE THIS AFTERNOON HAVE BEEN
HANDLING THE OVERALL EVOLUTION OF SHOWER DEVELOPMENT RATHER NICELY
THIS EVENING. SHOWER ACTIVITY WILL CONTINUE TO EXPAND IN AREAL
COVERAGE OVERNIGHT AS TROF AXIS AND ASSOCIATED HEIGHT FALLS/COLD MID-
LEVEL TEMPS MOVES OVER THE AREA. THE LIQUID QPF FORECAST FOR THE
NEXT 12-18 HOURS MAY BE A TOUCH TOO LOW IN SPOTS. THE EVENING RUNS
OF THE HRRR HAVE AREAS OF 0.25" TO 0.60" WITH LOCALLY HIGHER
AMOUNTS. 00Z NAM 12 HR QPF KINDA SIMILAR WHILE THE NAMDNG25 IS
HITTING THE CHIRICAHUA MOUNTAINS A LITTLE HARDER THAN CURRENTLY
FORECAST. THE WILL RUN OUT AN UPDATE TO ADD SLIGHT CHANCE OF
THUNDERSTORMS...INCREASE SOME LIQUID QPF AND SNOWFALL
AMOUNTS...ESPECIALLY ACROSS THE SOUTHERN MTNS. WINTER WEATHER
ADVISORY ABOVE 5000 FEET WILL REMAIN IN EFFECT FOR THE MOUNTAINS
FROM TUCSON NORTHEAST INTO SATURDAY. WITH ABOVE THINKING ON THE
CHIRICAHUA MOUNTAINS WILL ADD THEM TO THE WINTER WEATHER ADVISORY
BUT HAVE A LATER STARTING TIME.
FOR SATURDAY...WE MAY BE ENDING SHOWER ACTIVITY A LITTLE TOO QUICK.
SOMETHING FOR THE MID-SHIFT CREW TO PONDER. WHAT WILL BE NOTICEABLE
ON SATURDAY WILL BE THE DRAMATICALLY COOLER TEMPERATURES WITH HIGHS
10-20 DEGREES COLDER THAN TODAY. IN FACT MOST LOCATIONS FROM TUCSON
EAST WILL LIKELY SEE THEIR DAILY HIGHS OCCURRING BETWEEN MIDNIGHT
AND 3 AM.
SEE PREVIOUS DISCUSSION BELOW FOR FURTHER FORECAST DETAILS
FOR SATURDAY NIGHT INTO NEXT WEEK.
&&
.AVIATION...VALID THRU 13/00Z.
EXPECT SCATTERED TO NUMEROUS -SHRA AND HIGHER TERRAIN -SHSN INTO
SATURDAY MORNING. PRECIP WILL END AT KTUS BY ABOUT 18Z SATURDAY BUT
CONTINUE EAST OF KTUS INTO SATURDAY AFTERNOON. MVFR CONDITIONS AND
OCCASIONAL IFR CONDITIONS WILL EXIST THIS EVENING INTO SATURDAY
MORNING...ESPECIALLY NEAR HIGHER TERRAIN. OTHERWISE...CLOUD DECKS
WILL LOWER TO BETWEEN 8-12K FT AGL THIS EVENING INTO SATURDAY
MORNING. SURFACE WIND FROM KTUS WWD WILL DIMINISH TO LESS THAN 10
KTS BY 12/06Z. SURFACE WIND EAST OF KTUS WILL REMAIN SLY/SWLY AT 12-
18 KTS WITH GUSTS OF 25 KTS. AVIATION DISCUSSION NOT UPDATED FOR TAF
AMENDMENTS.
&&
.FIRE WEATHER...VALLEY RAIN AND MOUNTAIN SNOW SHOWERS WILL EXPAND
ACROSS SOUTHEAST ARIZONA OVERNIGHT INTO SATURDAY ALONG WITH MUCH
COOLER TEMPERATURES. EXPECT PRECIPITATION TO END FROM WEST-TO-EAST
BY SATURDAY EVENING. GUSTY NORTHWEST WINDS WILL OCCUR SATURDAY
MAINLY EAST OF TUCSON AND ESPECIALLY IN THE UPPER GILA RIVER VALLEY
INCLUDING SAFFORD. DRY CONDITIONS WILL OCCUR SUNDAY. THERE IS A
SLIGHT CHANCE OF VALLEY RAIN AND MOUNTAIN SHOWERS MONDAY AND MONDAY
NIGHT FOR AREAS MAINLY NORTH AND EAST OF TUCSON...ALONG WITH ANOTHER
ROUND OF GUSTY AFTERNOON SOUTHWEST WINDS. DRY CONDITIONS WITH LIGHT
TERRAIN DRIVEN 20-FOOT WINDS WILL THEN PREVAIL THROUGH THE END OF
NEXT WEEK.
&&
.PREV DISCUSSION... A SLIGHT CHANCE OF SNOW SHOWERS CONTINUES MAINLY
ACROSS THE WHITE MOUNTAINS SAT EVENING...THEN DRY CONDITIONS WILL
OCCUR AREA-WIDE LATE SAT NIGHT THRU SUN NIGHT. THE NEXT UPPER TROUGH
IS THEN PROGGED TO MOVE EWD ACROSS THE GREAT BASIN SUN NIGHT...THEN
ACROSS ARIZONA MON. THERE WERE SOME DIFFERENCES AMONGST THE MODELS
REGARDING PRECIP POTENTIAL ASSOCIATED WITH THIS SYSTEM MON INTO MON
NIGHT. GIVEN THESE DIFFERENCES...OPTED FOR ONLY VERY MINOR
MODIFICATIONS TO POPS.
THUS...THERE IS A SLIGHT CHANCE OF VALLEY RAIN/MOUNTAIN SNOW SHOWERS
ACROSS MUCH OF THE AREA MON...THEN A SLIGHT CHANCE OF VALLEY RAIN/
MOUNTAIN SNOW SHOWERS CONTINUES ACROSS ERN SECTIONS MON NIGHT. HAVE
MAINTAINED A SLIGHT CHANCE OF SNOW SHOWERS ACROSS THE WHITE
MOUNTAINS TUE. DRY CONDITIONS WILL THEN PREVAIL AREA-WIDE TUE NIGHT-
FRI.
MUCH COOLER TEMPS WILL OCCUR SAT...THEN DAYTIME TEMPS WILL AVERAGE
ABOUT 10-15 DEGS BELOW NORMAL SUN-WED. MARKEDLY WARMER TEMPS ARE ON
TAP LATE NEXT WEEK. MEANWHILE...FREEZING TEMPS OR PERHAPS A HARD
FREEZE MAY OCCUR FOR THE TUCSON METRO AREA LATE TUE NIGHT/EARLY WED
MORNING AND AGAIN LATE WED NIGHT/EARLY THUR MORNING.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL TO 5 PM MST SATURDAY FOR
AZZ510-511-514 ABOVE 5000 FEET.
WINTER WEATHER ADVISORY 1 AM TO 5 PM SATURDAY FOR AZZ512 ABOVE
5000 FEET.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
937 PM MST FRI DEC 11 2015
.SYNOPSIS...
A STRONG PACIFIC LOW PRESSURE SYSTEM AND COLD FRONT WILL MOVE
THROUGH THE REGION TONIGHT AND SATURDAY...GENERATING COOLER AND
WINDY CONDITIONS. A CHANCE OF SHOWERS ARE ALSO FORECAST MAINLY OVER
PORTIONS OF SOUTH CENTRAL ARIZONA FROM THIS EVENING THROUGH AT LEAST
MIDDAY ON SATURDAY...WITH ACCUMULATING SNOW POSSIBLE ABOVE 5000 FEET
OVER THE HIGHER TERRAIN EAST OF PHOENIX. CLEAR AND COLDER WEATHER IS
THEN EXPECTED SUNDAY...WITH ANOTHER COLD FRONT FORECAST TO MOVE INTO
THE REGION ON MONDAY. A MUCH COLDER AIRMASS IS FORECAST TO SETTLE
OVER THE REGION FROM TUESDAY INTO THURSDAY...POSSIBLY GENERATING
SOME OF THE COLDEST LOW TEMPERATURES SO FAR THIS SEASON.
&&
.DISCUSSION...
LATEST MESOANALYSIS SHOWS THE MID-TROPOSPHERIC TROUGH AXIS ACROSS THE
IMPERIAL VALLEY BUT PROGRESSING STEADILY EASTWARD. TWELVE-HOUR HEIGHT
FALLS OF NEARLY 180 M HAVE BEEN OBSERVED ACROSS THE NORTHERN BAJA
PENINSULA. THE BREEZY CONDITIONS WERE SLOW TO MATERIALIZE BEHIND THE
COLD FRONT THAT MOVED THROUGH CENTRAL AZ THIS AFTERNOON...THOUGH
WINDS HAVE PICKED UP OVER THE PAST FEW HOURS. MEANWHILE...AREAS OF
LIGHT PRECIPITATION ARE FILLING IN ACROSS CENTRAL AZ IN RESPONSE TO
STRONG FORCING FOR ASCENT ASSOCIATED WITH WELL-DEFINED PVA ACROSS THE
LOWER CO RIVER VALLEY.
HI-RES GUIDANCE INCLUDING LATEST RUNS OF THE HRRR CONTINUE TO
INDICATE THAT THE BEST CHANCE OF PRECIPITATION WILL BE ACROSS
NORTHERN MARICOPA COUNTY AND EAST OF PHOENIX IN THE HIGHER TERRAIN OF
GILA COUNTY THROUGH SATURDAY MORNING. QPF WAS INCREASED THIS EVENING
FOR THE 06-12Z PERIOD ACROSS THE HIGHER ELEVATIONS BASED ON THE
LATEST MODEL CONSENSUS. A FEW INCHES OF SNOW ARE LIKELY ABOVE 5K FT
AND A WINTER WEATHER ADVISORY REMAINS IN EFFECT FOR THESE AREAS.
LATEST SPC GUIDANCE ALSO SUGGESTS THAT AN ISOLATED LIGHTNING STRIKE
IS POSSIBLE IN THE STRONGEST CELLS.
.PREVIOUS DISCUSSION...
TONIGHT THROUGH SUNDAY...
A STRONG...AND COLD PACIFIC TROF CONTINUES TO APPROACH ARIZONA AT
THIS HOUR...WITH RAINFALL NOW BEING REPORTED ACROSS THE SOUTHERN CA
COASTAL REGIONS...AND ACROSS SOUTHERN NV AND EXTREME NW AZ. AHEAD OF
THE MAIN TROF AXIS...THE SFC COLD FRONT IS NOW MOVING INTO WESTERN
AZ...WITH LOCALLY GUSTY WINDS OCCURRING AT SOME LOCATIONS DURING THE
FRONTAL PASSAGE. ALTHOUGH THIS SYSTEM DOES NOT CONTAIN TOO MUCH
MOISTURE (PWATS MAINLY AOB 0.60 INCH)...THE COMBINATION OF STRONG
DYNAMICS/MAJOR HEIGHT FALLS (24HR 500MB HEIGHT FALLS IN THE 200-250M
RANGE ACROSS SOUTH-CENTRAL AZ) AND STRONG COOLING THROUGH THE COLUMN
IS EXPECTED TO ALLOW THE SYSTEM TO MAXIMIZE THE USE OF ITS AVAILABLE
MOISTURE. IT APPEARS THE BEST CHANCE FOR MEASURABLE PRECIP WILL BE
FROM THIS EVENING THROUGH ABOUT MIDDAY ON SATURDAY...WITH THE NCEP
SREF PLUME MEAN SHOWING TOTAL QPF AMOUNTS RANGING FROM AROUND 0.10
OF AN INCH OVER THE LOWER DESERTS OF SOUTH-CENTRAL AZ UP TO AS MUCH
AS 0.50 OF AN INCH OVER THE HIGHER TERRAIN EAST OF PHOENIX.
ALONG WITH THE RAINFALL...MUCH COLDER AIR MOVING INTO THE REGION IS
EXPECTED TO DROP SNOW LEVELS AOB 5000 FEET BY EARLY SAT
MORNING...WHICH WILL BE EARLY ENOUGH TO ALLOW THE RAIN TO CHANGE TO
SNOW BEFORE IT ENDS...WITH 2-4 INCHES POSSIBLE ABOVE 5000 FEET OVER
SOUTHERN GILA COUNTY. 850MB TEMPS...THAT ARE EXPECTED TO FALL AS LOW
AS 0C...WILL MAKE IT VERY DIFFICULT FOR FOR HIGHS TO GET MUCH ABOVE
60F ACROSS THE LOWER DESERTS OF SOUTH-CENTRAL AZ. SKIES ARE EXPECTED
TO CLEAR SAT NIGHT AS THE MAIN UPPER TROF MOVES OFF TO THE
EAST...WITH LOWS SUNDAY MORNING FALLING INTO THE 30S AT MANY LOWER
DESERT LOCATIONS...WITH TEMPERATURES NEAR...OR JUST BELOW FREEZING
LIKELY AT THE COLDEST LOCATIONS.
MONDAY THROUGH THURSDAY...
ANOTHER...EVEN COLDER AIRMASS IS EXPECTED TO MOVE INTO THE REGION
DURING THIS PERIOD...AS A 2ND UPPER TROF MOVES INTO THE REGION FROM
THE EASTERN GULF OF ALASKA. THIS SYSTEM WILL BE TAKING A MORE
EASTERLY TRACK THAN THE ONE THAT WILL BE AFFECTING US OVER THE
WEEKEND...WHICH WILL ALLOW IT TO TAP VERY COLD AIR THAT IS NOW
PARKED OVER ALASKA/NW CANADA. CURRENT EURO AND GFS FORECASTS...AND
MOST OF THEIR MEMBERS ARE IN VERY GOOD AGREEMENT ON THE TIMING AND
INTENSITY OF THIS UPCOMING COLD SNAP. BOTH THE EURO AND GFS
OPERATIONAL RUNS DROP 700MB TEMPS INTO THE -10C TO -13C RANGE ACROSS
OUR CWA BY MONDAY EVENING...THEN HOLD IT IN THIS RANGE THROUGH EARLY
WED MORNING BEFORE TEMPERATURES GRADUALLY MODERATE INTO THURSDAY.
THE COMBINATION OF THE VERY COLD AIR ALOFT AND A DRY AIRMASS (SFC
DEWPOINTS IN THE TEENS AND LOW 20S) WILL ALLOW MANY LOWER DESERT
LOCATIONS TO SEE LOWS AOB FREEZING ON WED AND THU MORNING...WITH THE
COLDEST LOCATIONS SEEING LOWS WELL DOWN IN THE 20S...WITH FREEZE
WARNINGS LIKELY NEEDED DURING THIS PERIOD. HIGHS DURING THIS PERIOD
WILL ME MOSTLY IN THE MID TO UPPER 50S ACROSS THE LOWER DESERTS.
&&
.AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND
KSDL... SURFACE COLD FRONT WILL MOVE THROUGH THE CENTRAL DESERTS
LATER THIS AFTERNOON AND THROUGH THE EARLY EVENING HOURS...LEADING
TO AN INCREASE IN BREEZY WEST WINDS WITH OCCASIONAL GUSTS TO 25KT OR
MORE EXPECTED. BEHIND THE FRONT...CIGS WILL STEADILY LOWER AS THE
MAIN UPPER TROF SETTLES INTO EASTERN ARIZONA...BY MIDNIGHT WE SHOULD
SEE SCT CIGS DOWN TO AROUND 6K FEET WITH SCATTERED LIGHT SHOWERS
DEVELOPING. AFTER MIDNIGHT CIGS MAY LOWER ADDITIONALLY...POSSIBLY
DOWN TO AROUND 3K FEET ALTHOUGH CIGS THAT LOW WILL PROBABLY STAY
NORTH AND EAST OF KPHX. EXPECT PARTIAL CLEARING FROM THE WEST BY MID
MORNING ON SATURDAY EVENTUALLY BECOMING PARTLY TO MOSTLY SUNNY WITH
LINGERING CU/SC AROUND 6-8K FEET BY MID AFTERNOON.
LOCALLY BREEZY WEST WIND LIKELY THROUGH MIDNIGHT WITH WIND BECOMING
LIGHTER AND SOUTH/SOUTHEAST AFTER 2AM OR SO. WINDS RETURNING TO THE
WEST/NORTHWEST BY SAT AFTERNOON BUT LIGHTER THAN THIS EVENING.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
PASSING LOW PRESSURE SYSTEM WILL BRING BREEZY/LOCALLY WINDY
CONDITIONS THIS AFTERNOON...ESPECIALLY AT KIPL...BUT NOT MUCH IN
TERMS OF PRECIP. MOST CLOUD DECKS WILL BE AOA 8K FEET WITH BKN DECKS
MOSTLY AOA 10-12K FEET. MAY SEE A STRAY SHOWER NEAR KBLH THIS
AFTERNOON AND EVENING...BUT NOTHING AFTER MIDNIGHT. WINDS HAVE NOT
BEEN AS STRONG AS EXPECTED AT KIPL TODAY BUT THERE MAY BE A FEW
GUSTS TO NEAR 30KT AT KIPL INTO THE EARLY EVENING BEFORE THEY
GRADUALLY TAPER OFF. LOCALLY BREEZY NORTH TO NORTHWEST WINDS SHOULD
SET IN OVER THE WESTERN DESERTS...ESPECIALLY KBLH...BY LATE MORNING
ON SUNDAY.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE PERIOD AS A
COUPLE OF LOW PRESSURE TROUGHS AFFECT THE REGION. A CHANCE OF
SHOWERS TO MAINLY HIGHER TERRAIN LOCATIONS NORTH AND EAST OF PHOENIX
IS POSSIBLE ON MONDAY WITH EVERY OTHER DAY STAYING PRECIP FREE. THE
COOL TEMPERATURES WILL ALLOW FOR HIGHER HUMIDITIES WITH MINIMUM
AFTERNOON VALUES ONLY FALLING INTO A 20 TO 40 PERCENT RANGE. GUSTY
NORTHWESTERLY WINDS ARE LIKELY ON MONDAY AND TUESDAY...ESPECIALLY
AFFECTING THE LOWER COLORADO RIVER VALLEY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...WINTER WEATHER ADVISORY UNTIL NOON MST SATURDAY FOR AZZ024.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...PERCHA
AVIATION...CB
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS RENO NV
710 PM PST SUN DEC 13 2015
.UPDATE...
JUST A QUICK UPDATE TO ALLOW THE WINTER STORM WARNING AND WINTER
WEATHER ADVISORY TO EXPIRE FOR PORTIONS OF NORTHEAST CALIFORNIA
INCLUDING LASSEN COUNTY AND THE SURPRISE VALLEY. SNOWFALL HAS
DIMINISHED ACROSS THESE AREAS BUT A FEW SNOW SHOWERS ARE POSSIBLE
OVER THE NEXT FEW HOURS THROUGH THE SIERRA VALLEY WITH AN
ADDITIONAL INCH OF ACCUMULATION POSSIBLE.
ELSEWHERE, A NW-SE ORIENTED BAND OF SNOWFALL CONTINUES FROM ABOUT
PORTOLA THROUGH SOUTH RENO AND TO JUST NORTH OF WALKER LAKE. THIS
BAND WILL CONTINUE TO TRACK SOUTH TONIGHT WITH AN ADDITIONAL 1-2
INCHES OF ACCUMULATION POSSIBLE IN HEAVIER PORTIONS OF THE BAND.
MOTORISTS SHOULD STAY CAUTIOUS OF ICE FORMING ON UNTREATED ROAD
SURFACE TONIGHT ESPECIALLY IN THE RENO AREA. NDOT ROAD CAMS
INDICATE THAT THE LIGHT SNOWFALL WE RECEIVED EARLIER HAS MELTED.
THIS PRESENTS A THREAT TO FORM ICE ON ROADS TONIGHT AS
TEMPERATURES DIP BELOW FREEZING. FUENTES
&&
.PREVIOUS DISCUSSION... /ISSUED 110 PM PST SUN DEC 13 2015/
SYNOPSIS...
A FAST MOVING STORM WILL BRING MODERATE TO HEAVY SNOW SOUTH OF
HIGHWAY 50 TONIGHT THEN EXIT TO THE EAST BY MONDAY MORNING.
SIGNIFICANT TRAVEL IMPACTS AND DELAYS ARE EXPECTED FOR THE SIERRA
THROUGH TONIGHT, WITH SLICK ROADS ALSO POSSIBLE TONIGHT IN WESTERN
NEVADA. A DRYING TREND WILL FOLLOW WITH COLD TEMPERATURES THROUGH
MIDWEEK. A POTENTIAL FOR A WINTER STORM NEXT WEEKEND EXISTS BUT
THERE IS LOW FORECAST CERTAINTY.
SHORT TERM...
SO THIS STORM HAS TAKEN ON A DIFFERENT CHARACTERISTIC THIS
AFTERNOON AS THE SFC FRONT HAS SPED UP FAR MORE THAN THE MOST
RECENT NUMERICAL MODEL GUIDANCE WOULD SUGGEST. THIS HAS RESULTED
IN HEAVY PRECIPITATION MAKING ITS WAY INTO WESTERN NEVADA WELL
AHEAD OF THE COLDEST AIR AND CAUSING PCPN INTENSITY TO SLOW IN THE
NORTHERN SIERRA EARLIER THAN FORECAST. ALL OF THIS CAN SEVERELY
IMPACT THE AMOUNT OF QPF AND SNOW THAT WE RECEIVE IN THIS STORM.
THERE IS A GLIMMER OF HOPE THAT MANY AREAS...ESPECIALLY EAST OF
THE SIERRA...COULD STILL PICK UP APPRECIABLE SNOW THIS EVENING AND
OVERNIGHT. MOST OF THE MODELS PERSIST IN DEVELOPING A BAND OF SNOW
OVER WESTERN NEVADA AND THE NORTHERN SIERRA LATER THIS EVENING AS
A SECONDARY WAVE MOVES THROUGH THE WEST NORTHWEST FLOW IN THE COLD
SECTOR OF THE UPPER TROUGH. THIS WAS THE REASON FOR EXTENDING THE
ADVISORIES FOR MONO COUNTY AND THE SIERRA FRONT AND ADDING AND
ADVISORY TO SOUTHERN LYON AND MINERAL COUNTIES. WE HAVE TO
CAUTION...HOWEVER...THAT CONFIDENCE IN THIS SOLUTION AND SNOW
AMOUNTS REMAINS QUITE LOW. WE DO THIS TO GIVE TRAVELERS A HEADS
UP THAT ROAD CONDITIONS EAST OF THE SIERRA COULD DETERIORATE
THROUGH THE EVENING.
GUSTY WINDS WERE AN ISSUE EARLIER IN THE DAY...BUT THESE HAVE
DECREASED AND ALL OF THE WIND ADVISORIES AND THE WARNING WILL BE
DROPPED.
AS THE UPPER LOW MOVES EAST MONDAY AND MONDAY NIGHT WRAP AROUND
SHOWERS ARE POSSIBLE...BUT SHOULD PRODUCE LIMITED SNOW AMOUNTS.
THE BIGGER STORY EARLY IN THE WEEK WILL BE MUCH COLDER
TEMPERATURES WITH HIGHS GENERALLY IN THE 30S IN THE VALLEYS AND
THE UPPER 20S TO NEAR 30 IN THE SIERRA. BY WEDNESDAY THESE
TEMPERATURES BEGIN TO WARM BUT WE ALSO SEE THE SIGNS OF WEAK OVER
RUNNING PCPN TRYING TO DEVELOP NEAR THE OREGON BORDER WEDNESDAY
NIGHT. 20
LONG TERM...(THURSDAY-SUNDAY)...
SO EVEN THOUGH ON THE BIG PICTURE THE LONG RANGE GUIDANCE HAS A
SIMILAR FLOW PATTERN OVER THE WESTERN US, THERE ARE SIGNIFICANT
DIFFERENCES IN STORM POTENTIAL LEADING TO FAIRLY LOW FORECAST
CONFIDENCE.
THURSDAY INTO THURSDAY NIGHT - STRONG WARM ADVECTION SCENARIO OVER
THE REGION LEADING TO INCREASED CHANCES OF PRECIP NORTH OF I-80. GFS
IS MUCH MORE ROBUST WITH QPF COMPARED TO ECMWF, SO HAVE MAINTAINED
MODERATE CHANCE POPS. IF GFS SCENARIO PANS OUT, FORECAST SOUNDINGS
AND INTENSITY OF WARM ADVECTION SUPPORT HEAVY SNOWS ACROSS MODOC
COUNTY INTO NW NEVADA. DEFINITELY WORTH WATCHING NOT ONLY FOR THIS
OUTCOME BUT ALSO POTENTIAL FOR PRECIP TO DROP FURTHER SOUTH THAN
CURRENTLY PROJECTED.
SATURDAY-MONDAY - WILL MAINTAIN LOW CHANCES FOR RAIN/SNOW MAINLY IN
THE SIERRA FOR THIS PERIOD AS THERE ARE MAJOR DIFFERENCES IN THE
GUIDANCE. GFS WOULD YIELD 2-3 BACK TO BACK MODERATE WINTER STORMS
WITHIN A PROGRESSIVE NW FLOW ALOFT, WHILE ECMWF DIGS THE STORM TRACK
FURTHER SOUTH INTO SOCAL SAT/SUN BUT STILL HAS A STORM INTO OUR
REGION MONDAY. EITHER WAY, THIS PATTERN BEARS WATCHING SINCE NEXT
WEEKEND WE`LL BE GETTING INTO THE PEAK PRE-CHRISTMAS TRAVEL PERIOD
WITH ENHANCED IMPACT POTENTIAL. CS
AVIATION...
TRICKY FORECAST WITH ONGOING WINTER STORM AND RAIN/SNOW TRANSITION
IN THE WESTERN NV VALLEYS (RNO/CXP). OVERALL FORECAST CONFIDENCE IN
THE TAFS IS ONLY LOW TO MEDIUM.
LATEST HRRR GUIDANCE AND UPSTREAM RADAR IMAGERY SUGGESTS CONTINUED
+SN IN THE SIERRA (TVL/TRK) THROUGH ~23Z BEFORE TRANSITIONING TO
SNOW SHOWERS. STRONG WIND AND SNOW AT MMH RIGHT NOW, EXPECTED TO
CONTINUE THROUGH ~3Z BEFORE FADING TO SNOW SHOWERS. NO DOUBT THERE
WILL BE SNOW ACCUMULATION IMPACTS TO RUNWAYS IN THE SIERRA, WITH
IFR/LIFR CONDITIONS.
IN WESTERN NV (RNO/CXP) STRONG S/SW WINDS WITH WIND SHEAR ON
APPROACH AND TURBULENCE ALOFT CONTINUE ~0Z BEFORE SWITCHING TO THE
W/NW AS COLD FRONT MOVES INTO THE REGION. RAIN WILL SWITCH TO
RAIN/SNOW MIX OR PERHAPS ALL WET SNOW BY 22Z BUT RUNWAY
ACCUMULATIONS HIGHLY UNLIKELY DUE TO WARM/WET GROUND AND A QUICK
TRANSITION TO SHOWERS. THIS EVENING, NAM/GFS GUIDANCE SHOW A
SECONDARY BAND OF SNOW DEVELOPING MAINLY SOUTH OF RNO THAT COULD PUT
DOWN 1-2" ACCUMULATIONS AT CXP AND NEARBY AIRFIELDS SUCH AS
NFL/HTH/YERINGTON. CONFIDENCE IN THIS FEATURE FORMING IS ONLY
LOW-MEDIUM, SO THERE`S A CHANCE IT MAY NOT HAPPEN AT ALL BUT
ENOUGH OF A RISK TO WARRANT MENTION. THE BAND OF SNOW COULD FORM
FAR ENOUGH NORTH TO AFFECT RNO BUT UNCERTAIN.
FOR MONDAY, COLD AIR OVERSPREADS THE REGION WITH NORTHERLY FLOW
ALOFT. STRONG GUSTY WINDS LIKELY IN FAVORED AREAS FOR NORTH FLOW
SUCH AS HTH/BIH/TPH. SCT-BKN VFR TO MVFR CEILINGS POSSIBLE
THROUGHOUT THE DAY WITH A FEW LIGHT SNOW SHOWERS IN THE SIERRA. CS
REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING NVZ005.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 8 AM PST
MONDAY NVZ001.
WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY NVZ003.
CA...WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING CAZ071.
WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING CAZ070.
WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY CAZ073.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ072.
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 8 AM PST MONDAY NVZ001.
WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY NVZ003.
CA...WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY CAZ073.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
344 PM PST SUN DEC 13 2015
.SYNOPSIS....SCATTERED SHOWERS WITH POSSIBLE THUNDERSTORMS CAN BE
EXPECTED COOL AND DRY WEATHER CONDITIONS ARE EXPECTED TO RETURN
TO MOST AREAS ON MONDAY AND PERSIST THROUGH MUCH OF THE WORK WEEK.
RAIN CHANCES MAY RETURN TO THE NORTH BAY BY THURSDAY...BUT NOT TO
THE REST OF THE REGION UNTIL NEXT WEEKEND.
&&
.DISCUSSION...AS OF 3:00 PM PST SUNDAY...BUSY DAY AT THE OFFICE AS
A STRONG COLD FRONT QUICKLY MOVED THROUGH OUR AREA. HRRR ENDED UP
VERIFYING NICELY BOTH WITH AMOUNTS AND TIMING AS MANY SPOTS PICKED
UP 1/3-2/3" WITH LOCAL SPOTS OVER 1". COASTAL RANGES ENDED UP WITH
EVEN HIGHER NUMBERS ESPECIALLY FOR THE NORTH BAY WHERE 1-2" HAS
FALLEN IN THE PAST 24 HOURS. WINDS ALSO VERIFIED NICELY WITH MANY
SPOTS GUSTING OVER 30 MPH WITH QUITE A FEW REPORTS OF SPEEDS OVER
40 MPH.
CONDITIONS HAVE CALMED CONSIDERABLY ALTHOUGH UNSTABLE AIR BEHIND
THE FRONT WILL LEAD TO MORE SHOWERS AND POSSIBLE THUNDERSTORMS
THROUGH TONIGHT. SMALL HAIL HAS BEEN REPOSTED WITH A FEW OF THE
STORMS AND THAT POSSIBILITY WILL CONTINUE THROUGH THE EVENING.
ADDITIONAL RAINFALL WILL GENERALLY BE UNDER 1/10" ALTHOUGH A FEW
SPOTS COULD SEE BRIEF MODERATE TO HEAVY RAIN WOULD WOULD GENERATE
UP TO AN ADDITIONAL 1/4". WIND SPEEDS HAVE ALREADY STARTED TO
LOWER (LAST HOUR ONLY ONE SPOT WAS OVER 40 MPH) SO THE WIND
ADVISORY WAS CANCELLED FOR OUR ENTIRE CWA. WOULD STILL EXPECT
BREEZY CONDITIONS, HOWEVER CRITERIA WILL NOT GENERALLY BE MET.
QUIET WEATHER IS FORECAST FOR MOST OF THE WORK WEEK AS RIDGING
TAKES PLACE ALONG THE COAST. THIS WILL HELP TO PUSH THE MAIN STORM
TRACK WELL TO OUR NORTH. AT THE SAME TIME COOL AIR WILL SETTLE
ACROSS THE REGION WITH OVERNIGHT TEMPS FOR MONDAY THROUGH
WEDNESDAY NIGHT FORECAST TO BE ON THE COLD SIDE. WIDESPREAD MID
30S TO MID 40S ARE EXPECTED EACH NIGHT WITH SOME NORTH BAY AND
SOUTHERN INTERIOR LOCATIONS LIKELY TO DROP INTO THE 28 TO 32
DEGREE RANGE. FOR NOW WILL NOT ISSUE A FROST ADVISORY. WILL
REEXAMINE THAT ON THE MIDNIGHT SHIFT WHEN NEW DATA IS AVAILABLE.
WARM AIR ADVECTION RAIN MAY RETURN AS EARLY ON THURSDAY FOR THE
NORTH BAY AS THE OVERALL FLOW STARTS TO FLATTEN OUT WHILE A SYSTEM
MOVES TO THE BC COASTLINE. RAIN CHANCES WILL THEN SPREAD DOWN THE
COAST AS THE SYSTEM PROGRESSES TO THE SOUTHEAST.
MODEL SOLUTIONS ARE IN POORER AGREEMENT BY THE END OF THE WEEK AS
A LONGWAVE TROF MOVES TOWARD THE COAST. A LOW WILL FORM IN THE
SOUTHERN PORTION OF THE TROF AND MOVE TO THE EAST NEAR OUR COAST.
WHERE THIS LOW ENDS UP GOING WILL DICTATE IF WE HAVE WIDESPREAD
RAIN OR IF MOST IF THE BULK OF THE RAIN MOVES TO OUR SOUTH. LATEST
ECMWF/GFS IS GOING WITH THE DRIER ROUTE FOR OUR CWA WHILE 12Z
INDICATED THAT IT WOULD MOVE STARTING INTO OUR REGION BY SUNDAY.
GFS ENSEMBLE MEAN APPROACH WOULD BRING RAIN TO OUR ENTIRE AREA BY
LATE SATURDAY. FOR NOW WILL KEEP THE CHANCE OF RAIN GOING FOR MOST
SPOTS.
RIGHT NOW 6 TO 10 AND 8 TO 14 DAY OUTLOOKS THAT WOULD TAKE US TO
DECEMBER 29TH FAVOR ABOVE NORMAL RAINFALL.
&&
.AVIATION...AS OF 4:00 PM PST SUNDAY...POST-FRONTAL SHOWERS
MOVING THROUGH THE AREA WILL TAPER OFF TONIGHT. STRONG WEST TO
NORTHWEST WINDS WILL CONTINUE TO BLOW THROUGH TONIGHT.
VICINITY OF KSFO...VFR WITH CIGS REMAINING ABOVE 4000 FEET IN
SHOWERS. WEST TO NORTHWEST WINDS GUSTING TO 35 KT SLOWLY
DECREASING TO 30 KT AFTER 03Z AND 20-25 KT AFTER 10Z.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR WITH CIGS REMAINING ABOVE 4000
FEET IN SHOWERS. WEST WINDS GUSTING TO 25 KT THROUGH 04Z.
&&
.MARINE...AS OF 3:00 PM PST SUNDAY...GUSTY WINDS WILL PERSIST
BEHIND A COLD FRONT THAT MOVED THROUGH THE COASTAL WATERS TODAY.
GALE FORCE GUSTS WILL CONTINUE THROUGH TONIGHT. SHOWERS AND
THUNDERSTORMS WILL ALSO BE POSSIBLE THIS EVENING. MODERATE
NORTHWEST WINDS WILL CONTINUE THROUGH MONDAY. WINDS WILL BECOME
LIGHTER WEDNESDAY AND THURSDAY AS HIGH PRESSURE BUILDS OVER THE
GREAT BASIN.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...SCA...PIGEON PT TO PT PINOS 0-10 NM
GLW...PT ARENA TO PT REYES 0-10 NM
GLW...PT ARENA TO PIGEON PT 10-60 NM
GLW...PIGEON PT TO PT PIEDRAS BLANCAS 10-60 NM
SCA...PT PINOS TO PT PIEDRAS BLANCAS 0-10 NM
SCA...ROUGH BAR ADVISORY FOR SF BAR
GLW...PT REYES TO PIGEON PT 0-10 NM UNTIL 2 AM
SCA...MRY BAY
SCA...SF BAY
&&
$$
PUBLIC FORECAST: BELL
AVIATION: W PI
MARINE: SIMS
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
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AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
127 PM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 127 PM MST SAT DEC 12 2015
LOW PRESSURE HAS CLOSED OFF OVER NORTHWESTERN NM...PUMPING
MOISTURE FROM SOUTH TO NORTH ACROSS CENTRAL COLORADO. WE ARE
BEGINNING TO SEE SOME WRAP-AROUND ENHANCEMENT ON RADAR ALONG THE
PARACHUTE TO NUCLA AREA...THOUGH NOT MUCH TO SPEAK OF AT THIS
POINT. WITH MOST OF THE DYNAMICS GONE WITH THIS SYSTEM ACROSS
EXTREME WESTERN COLORADO...ADDITIONAL SNOWFALL WILL TURN INTO AN
OROGRAPHIC EVENT THIS EVENING. DECIDED TO EXTEND NORTHERN SAN
JUANS ADVISORY UNTIL MIDNIGHT TONIGHT...WITH A SLIGHT GORGE
SIGNATURE ON THE SOUNDINGS. THAT BEING SAID...NOT EXPECTING A
GIANT GORGE EVENT...BUT RATHER SOME ENHANCEMENT FROM JUST SOUTH OF
OURAY UP TO THE MONUMENT ON HIGHWAY 550 FOR A FEW HOURS THIS
EVENING.
ALL OTHER WARNINGS AND ADVISORIES WILL END AT 6PM UNLESS OTHERWISE
CANCELLED EARLIER. THE SNOW IS EXPECTED TO END FROM NORTH TO SOUTH
AS THE CLOSED LOW PROGRESSES EASTWARD THROUGH THE NIGHT. AREAS OF
FOG ARE EXPECTED TONIGHT IN THE USUAL LOCATIONS...THE UINTA
BASIN...ALONG THE I-70 CORRIDOR BETWEEN GREEN RIVER AND
PALISADE...GRAND JUNCTION TO RIDGWAY CORRIDOR...AND THE SOUTHWEST
CO VALLEYS.
UPDATE ISSUED AT 953 AM MST SAT DEC 12 2015
VISIBILITY HAS BEEN INCREASING ACROSS THE GRAND VALLEY AND PARADOX
VALLEY. HAVE DROPPED DENSE FOG ADVISORIES JUST A BIT EARLY TO
ACCOMODATE FOR CURRENT CONDITIONS AND IMPROVEMENT EXPECTED DURING
THE AFTERNOON HOURS. ALSO DROPPED ZONE 7 WINTER WX ADVISORY EARLY
DUE TO THE END OF THE STEADY SNOW. LIGHT SNOW SHOWERS ARE STILL
POSSIBLE IN THIS AREA THROUGH THIS AFTERNOON. KEPT ZONE 22 IN
ADVISORY THROUGH THIS EVENING DESPITE CURRENT BREAK IN SHOWERS AT
DURANGO. HRRR AND RAP INDICATE ADDITIONAL SHOWERS IN THE ANIMAS
VALLEY THIS EVENING AS PRECIP BEGINS TO WRAP AROUND
COUNTERCLOCKWISE. WILL KEEP AN EYE ON TO SEE IF THESE EXPECTATIONS
CHANGE WITH FUTURE CONDITIONS AND MODEL RUNS.
UPDATE ISSUED AT 822 AM MST SAT DEC 12 2015
QUARTER MILE VISIBILITY REPORTED AT GJT AND NUCLA...THEREFORE
ISSUED A DENSE FOG ADVISORY FOR THE NEXT COUPLE OF HOURS FOR THESE
AREAS. ALSO ADDED ZONE 11 ANTICIPATING VISIBILITY TO DECREASE ONCE
THE SNOW COMPLETELY ENDS SHORTLY ALONG THE HIGHWAY 50 CORRIDOR
FROM WHITEWATER THROUGH MONTROSE.
UPDATE ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1048 AM MST SAT DEC 12 2015
CHALLENGING SET OF TAFS TODAY WITH THE CLOSED LOW MOVING INTO NEW
MEXICO TODAY...STREAMING PLENTY OF MOISTURE INTO WESTERN COLORADO
FROM THE SOUTH. FREQUENT MTN OBSCURATIONS WILL CONTINUE THROUGH
THE EVENING HOURS...WITH SNOW SHUTTING OFF OVER NORTH CENTRAL
COLORADO AFTER ABOUT 20Z. KCNY...KGJT...AND KMTJ WILL CLEAR OUT
LATER TODAY BUT WILL KEEP THE THREAT OF FOG IN THROUGH 12 TO 15Z
SUNDAY. FOG MAY ALSO DEVELOP AT KVEL TOWARD MORNING...SO ADDED
THIS AS WELL. GENERAL CLEARING WILL OCCUR AFTER 06Z TONIGHT
ALLOWING FOR IMPROVEMENT...ESPECIALLY AFTER 15Z SUNDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ018.
WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-019-022-023.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1048 AM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 953 AM MST SAT DEC 12 2015
VISIBILITY HAS BEEN INCREASING ACROSS THE GRAND VALLEY AND PARADOX
VALLEY. HAVE DROPPED DENSE FOG ADVISORIES JUST A BIT EARLY TO
ACCOMODATE FOR CURRENT CONDITIONS AND IMPROVEMENT EXPECTED DURING
THE AFTERNOON HOURS. ALSO DROPPED ZONE 7 WINTER WX ADVISORY EARLY
DUE TO THE END OF THE STEADY SNOW. LIGHT SNOW SHOWERS ARE STILL
POSSIBLE IN THIS AREA THROUGH THIS AFTERNOON. KEPT ZONE 22 IN
ADVISORY THROUGH THIS EVENING DESPITE CURRENT BREAK IN SHOWERS AT
DURANGO. HRRR AND RAP INDICATE ADDITIONAL SHOWERS IN THE ANIMAS
VALLEY THIS EVENING AS PRECIP BEGINS TO WRAP AROUND
COUNTERCLOCKWISE. WILL KEEP AN EYE ON TO SEE IF THESE EXPECTATIONS
CHANGE WITH FUTURE CONDITIONS AND MODEL RUNS.
UPDATE ISSUED AT 822 AM MST SAT DEC 12 2015
QUARTER MILE VISIBILITY REPORTED AT GJT AND NUCLA...THEREFORE
ISSUED A DENSE FOG ADVISORY FOR THE NEXT COUPLE OF HOURS FOR THESE
AREAS. ALSO ADDED ZONE 11 ANTICIPATING VISIBILITY TO DECREASE ONCE
THE SNOW COMPLETELY ENDS SHORTLY ALONG THE HIGHWAY 50 CORRIDOR
FROM WHITEWATER THROUGH MONTROSE.
UPDATE ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1048 AM MST SAT DEC 12 2015
CHALLENGING SET OF TAFS TODAY WITH THE CLOSED LOW MOVING INTO NEW
MEXICO TODAY...STREAMING PLENTY OF MOISTURE INTO WESTERN COLORADO
FROM THE SOUTH. FREQUENT MTN OBSCURATIONS WILL CONTINUE THROUGH
THE EVENING HOURS...WITH SNOW SHUTTING OFF OVER NORTH CENTRAL
COLORADO AFTER ABOUT 20Z. KCNY...KGJT...AND KMTJ WILL CLEAR OUT
LATER TODAY BUT WILL KEEP THE THREAT OF FOG IN THROUGH 12 TO 15Z
SUNDAY. FOG MAY ALSO DEVELOP AT KVEL TOWARD MORNING...SO ADDED
THIS AS WELL. GENERAL CLEARING WILL OCCUR AFTER 06Z TONIGHT
ALLOWING FOR IMPROVEMENT...ESPECIALLY AFTER 15Z SUNDAY.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-018-019-022-023.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
958 AM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 953 AM MST SAT DEC 12 2015
VISIBILITY HAS BEEN INCREASING ACROSS THE GRAND VALLEY AND PARADOX
VALLEY. HAVE DROPPED DENSE FOG ADVISORIES JUST A BIT EARLY TO
ACCOMODATE FOR CURRENT CONDITIONS AND IMPROVEMENT EXPECTED DURING
THE AFTERNOON HOURS. ALSO DROPPED ZONE 7 WINTER WX ADVISORY EARLY
DUE TO THE END OF THE STEADY SNOW. LIGHT SNOW SHOWERS ARE STILL
POSSIBLE IN THIS AREA THROUGH THIS AFTERNOON. KEPT ZONE 22 IN
ADVISORY THROUGH THIS EVENING DESPITE CURRENT BREAK IN SHOWERS AT
DURANGO. HRRR AND RAP INDICATE ADDITIONAL SHOWERS IN THE ANIMAS
VALLEY THIS EVENING AS PRECIP BEGINS TO WRAP AROUND
COUNTERCLOCKWISE. WILL KEEP AN EYE ON TO SEE IF THESE EXPECTATIONS
CHANGE WITH FUTURE CONDITIONS AND MODEL RUNS.
UPDATE ISSUED AT 822 AM MST SAT DEC 12 2015
QUARTER MILE VISIBILITY REPORTED AT GJT AND NUCLA...THEREFORE
ISSUED A DENSE FOG ADVISORY FOR THE NEXT COUPLE OF HOURS FOR THESE
AREAS. ALSO ADDED ZONE 11 ANTICIPATING VISIBILITY TO DECREASE ONCE
THE SNOW COMPLETELY ENDS SHORTLY ALONG THE HIGHWAY 50 CORRIDOR
FROM WHITEWATER THROUGH MONTROSE.
UPDATE ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 256 AM MST SAT DEC 12 2015
WIDESPREAD IFR CONDITIONS AND BELOW ARE BEING EXPERIENCED AT MOST
ASOS SITES THIS MORNING. ODD MAN OUT IS KVEL WHICH WILL LIKELY
STAY VFR SINCE THE FRONT HAS PASSED TO THE EAST. LOW CIGS/VIS
STILL POSSIBLE FOR THAT AERODROME SATURDAY NIGHT INTO SUNDAY
MORNING HOWEVER DUE TO FOG. SPEAKING OF...FOG POSSIBLE FOR MANY
TAF LOCATIONS THIS MORNING AND AGAIN TONIGHT. A HEAVIER BAND OF
PRECIP WILL CONTINUE TO SHIFT EASTWARD TODAY ALLOWING IMPROVING
CONDITIONS FOR KCNY...KGJT...KMTJ AND KRIL WHILE REMAINING TAF
SITES WILL LIKELY SEE CONTINUED PRECIP AND LOW FLIGHT CONDITIONS.
BY 21Z...MVFR/IFR CONDITIONS WILL HAVE LARGELY SHIFTED TO THE
CONTINENTAL DIVIDE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-018-019-022-023.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
825 AM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 822 AM MST SAT DEC 12 2015
QUARTER MILE VISIBILITY REPORTED AT GJT AND NUCLA...THEREFORE
ISSUED A DENSE FOG ADVISORY FOR THE NEXT COUPLE OF HOURS FOR THESE
AREAS. ALSO ADDED ZONE 11 ANTICIPATING VISIBILITY TO DECREASE ONCE
THE SNOW COMPLETELY ENDS SHORTLY ALONG THE HIGHWAY 50 CORRIDOR
FROM WHITEWATER THROUGH MONTROSE.
UPDATE ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 256 AM MST SAT DEC 12 2015
WIDESPREAD IFR CONDITIONS AND BELOW ARE BEING EXPERIENCED AT MOST
ASOS SITES THIS MORNING. ODD MAN OUT IS KVEL WHICH WILL LIKELY
STAY VFR SINCE THE FRONT HAS PASSED TO THE EAST. LOW CIGS/VIS
STILL POSSIBLE FOR THAT AERODROME SATURDAY NIGHT INTO SUNDAY
MORNING HOWEVER DUE TO FOG. SPEAKING OF...FOG POSSIBLE FOR MANY
TAF LOCATIONS THIS MORNING AND AGAIN TONIGHT. A HEAVIER BAND OF
PRECIP WILL CONTINUE TO SHIFT EASTWARD TODAY ALLOWING IMPROVING
CONDITIONS FOR KCNY...KGJT...KMTJ AND KRIL WHILE REMAINING TAF
SITES WILL LIKELY SEE CONTINUED PRECIP AND LOW FLIGHT CONDITIONS.
BY 21Z...MVFR/IFR CONDITIONS WILL HAVE LARGELY SHIFTED TO THE
CONTINENTAL DIVIDE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-018-019-022-023.
DENSE FOG ADVISORY UNTIL 10 AM MST THIS MORNING FOR COZ006-011-
020.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ007.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
654 AM MST SAT DEC 12 2015
.UPDATE...
ISSUED AT 654 AM MST SAT DEC 12 2015
STEADY SNOW HAS ENDED ACROSS EASTERN UTAH AND NORTHWEST
COLORADO...SO CANCELLED ADVISORIES AND WARNINGS IN UT ZONES 25 AND
28...AND CO ZONES 1...2 AND 3. THE POSSIBILITY OF A FEW FLURRIES
STILL EXISTS BUT THESE AREAS WILL NOT SEE ANY ADDITIONAL SNOW
ACCUMULATION. RAP AND HRRR INDICATING CONTINUATION OF SNOW ALONG
I-70 EAST OF GLENWOOD SPRINGS...IN THE SAN JUANS AND ALONG THE
CONTINENTAL DIVIDE.
UPDATE ISSUED AT 329 AM MST SAT DEC 12 2015
LATEST REPORT FROM DURANGO DISPATCH INDICATED 1 INCH OF SNOW
STICKING TO ROAD SURFACES WHILE WEBCAMS SHOWED SIMILAR CONDITIONS
AROUND TOWN. LATEST 06Z NAM CONTINUES TO SHOW BAND OF PRECIP OVER
MUCH OF SOUTHERN VALLEYS PERSISTING THROUGH MUCH OF THE DAY. IR
IMAGERY SHOWING PLENTY OF MOISTURE OVER THAT AREA AND MORE TO
COME FROM NEW MEXICO. SOME ENHANCEMENT CAN ALSO BE SEEN INDICATING
A GOOD POSSIBILITY FOR HEAVIER SNOWFALL. WATER VAPOR FURTHER
CORROBORATES THIS IDEA. WENT AHEAD AND ISSUED ADVISORIES FOR ALL
SOUTHERN VALLEYS FOR 2 TO 4 INCHES WITH HIGHER AMOUNTS POSSIBLE
FOR HIGHER ELEVATIONS. TEMPS CONTINUE TO HOVER AROUND FREEZING SO
WITH DAYBREAK...WOULD EXPECT SNOW ON ROADS TO MELT FAIRLY QUICKLY
WITH LITTLE IMPACT. IF THIS OCCURS...HIGHLIGHTS CAN BE TAKEN DOWN
EARLY.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
ANOTHER STORM IS EXCEEDING EXPECTATIONS IN SEVERAL AREAS. WE WERE
DEALING WITH A HEAVY SNOW BAND RELATED TO A WELL FORMED MID LEVEL
FRONTOGENESIS BAND ACROSS NORTHWEST COLORADO WHICH DUMPED UP TO A
FOOT OF NEW SNOW IN LOWER ELEVATIONS. NOW WE LOOK UPSTREAM AT THE
APPROACHING MAIN LOW PRESSURE SYSTEM ANALYZED AT 00Z OVER SOUTHERN
NEVADA...AND AT 06Z SATELLITE IMAGERY SUGGESTS THIS CIRCULATION
HAS MOVED TO CENTRAL ARIZONA. WOULD HAVE TO SAY THE TRENDS ARE
SLOWER AND FARTHER SOUTH WITH THIS SYSTEM THAN MODELS SUGGESTED
YESTERDAY. WITH THE CYCLONE STILL TO THE WEST THETA SURFACES
SUGGEST A NEW WARM CONVEYOR BELT DELIVERING A GOOD SHOT OF
MOISTURE INTO WESTERN COLORADO THIS MORNING. THIS IS MORE THAN
APPARENT WITH THE RECENT ENHANCEMENTS ON THE REGIONAL RADAR MOSAIC
AND IR SATELLITE IMAGERY OVER EASTERN ARIZONA. THE BIG FORECAST
CHALLENGE IS WHAT DOES THAT MEAN FOR OUR AREA. THE MOISTURE
ADVECTION AND CONSTANT STREAM OF VIRGA OR LIGHT SHOWERS THIS
EVENING HAS CLOSED THE DEW POINT GAP ACROSS THE SOUTHERN VALLEYS
WHERE TEMPERATURES ARE STILL IN THE UPPER 30S. THE REAL COLD AIR
IS STILL BEING HELD BACK BY THE FLOW ALOFT SO PRECIPITATION TYPE
IS STILL QUITE TRICKY FOR THE SOUTHERN VALLEYS AS RAIN MAY HOLD
OUT LONGER THAN ANTICIPATED OR JUST TURN INTO MELTING SNOW. FOR
NOW WILL SIDE WITH THE TRENDS OF NEAR AN INCH OF THE DURANGO
AIRPORT WITH HIGHER AMOUNTS NEAR THE FOOTHILLS. PAGOSA SPRINGS
WILL SEE ANYWHERE FROM TO 1 INCH TO 3 INCHES NEAR THE HILLS. THE
PROBLEM AREAS DOWN SOUTH WILL MOST LIKELY BE THE HIGH SPOTS ALONG
HWY 160 LIKE THE MANCOS HILL AREA. THIS WCB WILL ALSO CONTAIN
BETTER INSTABILITY AS SEEN IN EPV FIELDS AND THIS SHOULD BE
RELEASED BY THE INCREASING LARGE SCALE ASCENT OVER THE SOUTHERN
CWA AS THE MID LEVEL CIRCULATION PASSES THROUGH FROM MID MORNING
ONWARD. COMPLICATED SITUATION AND EXPECT CHANGES TO GOING FORECAST
THROUGH THE DAY AS SOME OF THE VARIABLES BECOME MORE CLEAR. THE
SOUTHERN MOUNTAINS MAY BE IN FOR MORE SNOW THAN PREVIOUSLY
FORECAST AND WILL BE MONITORING FOR UPGRADES IF IMPACTS TO PASSES
BECOME MORE APPARENT. WE DID INCLUDE THE GUNNISON BASIN IN THE
LATEST WSW AS THIS MOISTURE PLUME WILL BE DIRECTED AT CERRO SUMMIT
AND THE BLACK CANYON AREA. THE SYSTEM SLOWLY PULLS EAST OF THE
DIVIDE THIS EVENING BEFORE STRENGTHENING IN THE LEE SIDE. DID KEEP
SOME HIGHER POPS INTO THIS EVENING TO ACCOUNT FOR THE SLOWER
MOVEMENT. OVERALL THE PCPN SHOULD BE DONE BY MIDNIGHT WITH A DRY
SUNDAY ON TAP. TEMPERATURES AND NEW SNOWFALL WILL BE THE MAIN
CHALLENGE ALONG WITH AREAS OF FOG DEVELOPING IN THE VALLEYS AND
BASINS.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 256 AM MST SAT DEC 12 2015
RIDGING THAT BUILT IN SUNDAY WILL BE OVERHEAD SUNDAY NIGHT AND
QUICKLY SHIFT EASTWARD AS THE NEXT TROUGH APPROACHES FROM THE
WEST. MODELS IN FAIRLY GOOD AGREEMENT WITH EVOLUTION OF THIS
SYSTEM AND LOOKS SOMEWHAT SIMILAR TO THE STORM AFFECTING THE
REGION RIGHT NOW. SUBTLE DIFFERENCES EXIST OF COURSE BUT THE MAIN
GIST OF A COLD FRONT BRINGING WIDESPREAD SNOWFALL REMAINS. MAIN
DIFFERENCES WITH THIS SYSTEM WILL BE THAT COLD AIR WILL ALREADY BE
IN PLACE FROM THE PREVIOUS FRONT AND WILL ONLY BE REINFORCED FROM
THIS SECOND SYSTEM.
AS FAR AS DETAILS ARE CONCERNED...PRECIP WILL BEGIN MONDAY
MORNING FOR ERN UTAH AND SHIFT EASTWARD AS THE DAY PROGRESSES. BY
EVENING MOST...IF NOT ALL...AREAS WILL SEE SOME PRECIPITATION AS
THE CLOSED LOW AND ASSOD LIFT ARE POISED TO MOVE INTO WRN CO.
PLENTY OF THINGS CAN CHANGE BETWEEN NOW AND THEN THOUGH INCLUDING
THE LOW OPENING UP...UPPER LEVEL SUPPORT WANING...BEST LIFT SHIFTS
NORTH OR SOUTH...SO WILL HAVE TO SEE IF MODELS REMAIN CONSTANT IN
THIS OUTCOME. FOR NOW...6 TO 10 INCHES FOR THE MTNS AND 1 TO 3
INCHES FOR SOME VALLEYS LOOKS GOOD.
SNOWFALL WILL CONTINUE INTO TUESDAY BUT WITH BEST LIFT HAVING
SHIFTED TO THE PLAINS...ANTICIPATE A MORE SHOWERY NATURE TO
PRECIP. NORTHERLY FLOW WILL ALSO USHER IN COLDER AIR TO THE
REGION. SOME MTN SHOWERS...ESPECIALLY UP NORTH...MAY CONTINUE
THROUGH WEDNESDAY MORNING BUT ANTICIPATE MORE FLURRIES THAN
ANYTHING ELSE. MOST AREAS WILL SEE PARTLY CLOUDY SKIES AND MUCH
COLDER TEMPERATURES THAT WILL BE WELL BELOW NORMAL. AFTER
THAT...LITTLE PIECES OF WEAK ENERGY WILL DROP DOWN FROM THE NW
CAUSING SOME LIGHT SNOWFALL OVER THE PARK/GORE RANGES THROUGH
FRIDAY BUT AGAIN...NOT MUCH ACCUMULATION EXPECTED. EXPECT MORE
CLOUDS N OF I-70 THAN S DUE TO THESE DISTURBANCES. TEMPERATURES
WILL REMAIN BELOW NORMAL THROUGH LONG TERM PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 256 AM MST SAT DEC 12 2015
WIDESPREAD IFR CONDITIONS AND BELOW ARE BEING EXPERIENCED AT MOST
ASOS SITES THIS MORNING. ODD MAN OUT IS KVEL WHICH WILL LIKELY
STAY VFR SINCE THE FRONT HAS PASSED TO THE EAST. LOW CIGS/VIS
STILL POSSIBLE FOR THAT AERODROME SATURDAY NIGHT INTO SUNDAY
MORNING HOWEVER DUE TO FOG. SPEAKING OF...FOG POSSIBLE FOR MANY
TAF LOCATIONS THIS MORNING AND AGAIN TONIGHT. A HEAVIER BAND OF
PRECIP WILL CONTINUE TO SHIFT EASTWARD TODAY ALLOWING IMPROVING
CONDITIONS FOR KCNY...KGJT...KMTJ AND KRIL WHILE REMAINING TAF
SITES WILL LIKELY SEE CONTINUED PRECIP AND LOW FLIGHT CONDITIONS.
BY 21Z...MVFR/IFR CONDITIONS WILL HAVE LARGELY SHIFTED TO THE
CONTINENTAL DIVIDE.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ005-
008>010-012-014-018-019-022-023.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004-013.
WINTER WEATHER ADVISORY UNTIL NOON MST TODAY FOR COZ007.
UT...NONE.
&&
$$
UPDATE...JAM
SHORT TERM...15
LONG TERM...TGR
AVIATION...TGR
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
324 PM EST SAT DEC 12 2015
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFIED UPPER
LEVEL PATTERN OVER THE CONUS. PATTERN IS HIGHLIGHTED BY
DEEP/SHARP TROUGHING OVER THE INTER-MOUNTAIN WEST FOLLOWED BY
DOWNSTREAM RIDGING OVER THE EASTERN HALF OF THE NATION. THE
FLORIDA PENINSULA RESIDES UNDER THE BASE OF THIS RIDGE AND UNDER
SOME FAIRLY IMPRESSIVE HEIGHTS FOR THE MIDDLE OF DECEMBER. H5
HEIGHTS OVER THE CENTRAL PART OF THE STATE ARE AROUND 590DM OFF
THE MORNING KTBW SOUNDING...AND THIS REPRESENTS A VALUE ABOVE THE
90TH PERCENTILE FOR DECEMBER. THE 12Z KTBW SOUNDING SHOWED A
DEFINED SUBSIDENCE INVERSION AROUND 700MB...SEPARATING A SHALLOW
LAYER OF ATLANTIC MOISTURE FROM A VERY DRY COLUMN ALOFT. NEEDLESS
TO SAY...WITH SUCH A STRONG AND STACKED AREA OF RIDGING
ALOFT...OUR FORECAST AREA IS WELL PROTECTED FROM ANY INCLEMENT
SENSIBLE WEATHER THROUGH THE REMAINDER OF THE WEEKEND.
ALSO...WITH THE STRONG RIDGE ALOFT AND DECENT LOW LEVEL CONDITIONS
FOR DIURNAL MIXING...TEMPERATURES HAVE TOPPED OUT WELL ABOVE
NORMAL FOR THIS TIME OF YEAR. MANY LOCATIONS FIND THEMSELVES AS
MUCH AS 10+ DEGREES ABOVE NORMAL THIS AFTERNOON...AND THESE
UNSEASONABLE VALUES WILL CONTINUE FOR THE OVERNIGHT AND AGAIN ON
SUNDAY.
&&
.SHORT TERM (TONIGHT THROUGH SUNDAY)...
TEMPERATURES TONIGHT REMAINING IN THE 60S FOR JUST ABOUT ALL
LOCATIONS (PERHAPS A FEW COOLER SPOTS IN THE UPPER 50S FOR LEVY
COUNTY).
ALTHOUGH THE UPPER RIDGE WILL NOT BE QUITE AS STRONG BY
SUNDAY...WE WILL STILL BE LOOKING AT HEIGHTS WELL ABOVE
NORMAL...AND IT WILL STILL BE PLENTY IN CONTROL TO PROTECT OUR
REGION FROM ANY MID/UPPER LEVEL SYNOPTIC FORCING FOR LIFT. THE
CHANGE IN PATTERN THAT WE WILL SEE FOR SUNDAY WILL OCCUR IN THE
VERY LOWEST LEVELS OF THE COLUMN. A WEAK INVERTED TROUGH SEEN
CURRENTLY OUT TOWARD THE BAHAMAS IS SHOWN BY MOST ENSEMBLE MEMBERS
TO MIGRATE WESTWARD THROUGH THE NEXT 24 HOURS TO A POSITION OVER
THE SOUTHERN HALF OF THE FL PENINSULA SUNDAY AFTERNOON. A SLIGHT
INCREASE IN COLUMN MOISTURE BELOW 700MB IS FORECAST TO ARRIVE WITH
THIS FEATURE...ALONG A SWATH OF MODEST ISENTROPIC UPGLIDE ALONG
THE 300-310K SURFACES. EXTENT OF LIFT (ALTHOUGH IT IS SHALLOW)
COMBINED WITH THE ADDED SURFACE FOCUS UNDER THE TROUGH APPEARS
SUFFICIENT TO SUPPORT SOME WIDELY SCATTERED LIGHT SHOWERS TO THE
SOUTH OF THE I-4 CORRIDOR SUNDAY AFTERNOON/EARLY EVENING. AS
MENTIONED ALL THE MOISTURE IS SHALLOW...AND HENCE THE SHOWERS WILL
ALSO BE SHALLOW AND LIGHT...WITH PROB ONLY A COUPLE HUNDREDTHS OF
AN INCH FOR ANY LOCATION THAT DOES SEE A BRIEF SHOWER.
THEREFORE...THE IMPACT TO ANY OUTDOOR ACTIVITIES LOOKS NEGLIGIBLE.
THE SOUTHERN HALF OF THE AREA SHOULD CERTAINLY EXPECT TO SEE LESS
SUN FOR SUNDAY AS A COMBINATION OF CUMULUS AND STRATOCU ARE LIKELY
TO FILL IN QUITE QUICKLY. CURRENT GRIDS HAVE 20-30% SHOWER
COVERAGE...AND BASED ON AVAILABLE 12Z GUIDANCE DO NOT SEE MUCH
REASON TO MAKE MANY SIGNIFICANT CHANGES WITH THIS FORECAST
PACKAGE.
&&
.LONG TERM...
AN UPPER-LEVEL RIDGE OVER FLORIDA TO END THE WEEKEND WILL SHIFT
EASTWARD THROUGH MONDAY AS AN UPPER-LEVEL LOW TRACKS NORTHEASTWARD
THROUGH THE CENTRAL PLAINS TOWARD THE GREAT LAKES REGION. AT THE
SURFACE...HIGH PRESSURE WILL BEGIN TO PUSH OFF THE EASTERN SEABOARD
AS A COLD FRONT ENTERS THE FLORIDA PANHANDLE REGION. GLOBAL MODELS
CONTINUE TO SHOW A RATHER ILL-DEFINED PASSAGE OF THIS FRONT MONDAY
NIGHT INTO TUESDAY AS THE SUPPORT LIFTS WELL AWAY FROM THE AREA. AS
OF THIS FORECAST PACKAGE...IT DOES NOT LOOK LIKE THE FRONT WILL
ACTUALLY CLEAR THE ENTIRE FORECAST AREA...INSTEAD HANGING UP
SOMEWHERE ACROSS THE CENTRAL PENINSULA. SOME SHOWERS ARE CERTAINLY
POSSIBLE THROUGH WEDNESDAY...BUT HAVE KEPT CHANCE POPS OR LESS WITH
QPF AMOUNTS NOT EXPECTED TO BE ALL THAT HIGH FOR THE MOST PART.
OUR NEXT REAL WEATHER-MAKER LOOKS TO TAKE SHAPE WEDNESDAY NIGHT INTO
THURSDAY AS A DEEPER UPPER-LEVEL TROUGH SWINGS THROUGH THE CENTRAL
PART OF THE COUNTRY WITH SURFACE LOW PRESSURE DEVELOPING ALONG THE
NORTHERN GULF COAST. FOR NOW...MODELS ARE SHOWING THE BEST CHANCES
FOR RAIN THURSDAY INTO FRIDAY...WITH RAIN COMING TO AN END SATURDAY
AS A MUCH COOLER AND DRIER AIR MASS FILTERING INTO THE REGION.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AND EVENING
HOURS TODAY ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA. EASTERLY
TERMINALS WILL SEE EASTERLY WINDS AND A FEW-SCT CUMULUS FIELD
DEVELOPING DURING THE AFTERNOON. POTENTIAL FOR PATCHY AREAS OF FOG
TO IMPACT SITES SUCH AS KLAL/KPGD AFTER 08Z TONIGHT...HOWEVER...
BETTER CHANCES FOR FOG AND ASSOCIATED RESTRICTIONS LOOK TO REMAIN
NORTH OF THE FORECAST TERMINALS. EARLY FOG LIFTS BY 14Z...FOLLOWED
BY VFR CONDITIONS THROUGH SUNDAY AFTERNOON.
&&
.MARINE...
HIGH PRESSURE TO THE NORTH OF THE COASTAL WATERS WILL
KEEP MODERATE EAST WINDS IN PLACE THROUGH THE WEEKEND. A COLD
FRONT WILL APPROACH THE AREA AND STALL OVER THE NORTHEAST GULF
OF MEXICO DURING THE EARLY PART OF NEXT WEEK. CHANCES FOR SHOWERS
WILL INCREASE MONDAY INTO TUESDAY ASSOCIATED WITH THIS FRONT.
WINDS AND SEAS ARE GENERALLY EXPECTED TO REMAIN BELOW HEADLINE
CRITERIA.
&&
.FIRE WEATHER...
HIGH PRESSURE WILL SHIFT OFF THE SOUTHEAST COAST INTO THE ATLANTIC
THROUGH MONDAY ALLOWING WINDS TO SHIFT MORE TO THE SOUTH AHEAD OF
AN APPROACHING FRONT. THIS FRONT WILL STALL ACROSS THE REGION BY
TUESDAY WITH INCREASING CHANCES FOR SCATTERED SHOWERS. RELATIVE
HUMIDITY VALUES WILL REMAIN WELL ABOVE CRITICAL LEVELS THROUGH
THE FORECAST PERIOD...ALTHOUGH DISPERSION INDICES ON SUNDAY ARE
FORECAST TO BE HIGH.
FOG POTENTIAL...
PATCHY FOG IS EXPECTED LATE TONIGHT/EARLY SUNDAY MORNING. THE BEST
CHANCES FOR FOG ON SUNDAY WILL BE TO THE NORTH OF THE I-4
CORRIDOR.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 66 81 69 81 / 0 10 10 10
FMY 67 82 70 84 / 0 30 20 10
GIF 65 81 68 84 / 0 20 20 20
SRQ 66 79 69 80 / 0 20 10 10
BKV 63 81 67 83 / 0 10 10 10
SPG 67 80 70 81 / 0 10 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH MONDAY EVENING FOR COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM...CARLISLE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
1101 AM EST SAT DEC 12 2015
.UPDATE...
16Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AN AMPLIFIED UPPER LEVEL
PATTERN OVER THE CONUS TO START OUT THE WEEKEND. PATTERN IS
HIGHLIGHTED BY DEEP/SHARP TROUGHING OVER THE INTER-MOUNTAIN WEST
FOLLOWED BY DOWNSTREAM RIDGING OVER THE EASTERN HALF OF THE
NATION. THE FLORIDA PENINSULA RESIDES UNDER THE BASE OF THIS RIDGE
AND UNDER SOME FAIRLY IMPRESSIVE HEIGHTS FOR THE MIDDLE OF
DECEMBER. H5 HEIGHTS OVER THE CENTRAL PART OF THE STATE ARE AROUND
590DM OFF THE MORNING KTBW SOUNDING...AND THIS REPRESENTS A VALUE
ABOVE THE 90TH PERCENTILE FOR DECEMBER. THE 12Z KTBW SOUNDING
SHOWED A DEFINED SUBSIDENCE INVERSION AROUND 700MB...SEPARATING A
SHALLOW LAYER OF ATLANTIC MOISTURE FROM A VERY DRY COLUMN ALOFT.
NEEDLESS TO SAY...WITH SUCH A STRONG AND STACKED AREA OF RIDGING
ALOFT...OUR FORECAST AREA IS WELL PROTECTED FROM ANY INCLEMENT
SENSIBLE WEATHER FOR TODAY.
ALSO...WITH THE STRONG RIDGE ALOFT AND DECENT LOW LEVEL CONDITIONS
FOR DIURNAL MIXING...TEMPERATURES WILL TOP OUT WELL ABOVE NORMAL
FOR THIS TIME OF YEAR. MANY LOCATIONS WILL FIND THEMSELVES AS MUCH
AS 10 DEGREES ABOVE NORMAL THIS AFTERNOON...AND THESE
UNSEASONABLE VALUES WILL CONTINUE FOR THE OVERNIGHT AND AGAIN ON
SUNDAY.
THE REST OF TODAY WILL FEATURE MOSTLY SUNNY SKIES BECOME PARTY
SUNNY FOR A TIME DURING THE AFTERNOON. TEMPERATURES CLIMB INTO THE
LOW 80S FOR MANY SPOTS AWAY FROM THE IMMEDIATE COAST...WITH EVEN A
FEW MIDDLE 80S DOWN TOWARD FORT MYERS. TEMPERATURES TONIGHT
REMAINING IN THE 60S FOR JUST ABOUT ALL LOCATIONS (PERHAPS A FEW
COOLER SPOTS IN THE UPPER 50S FOR LEVY COUNTY).
ALTHOUGH THE UPPER RIDGE WILL NOT BE QUITE AS STRONG BY
SUNDAY...WE WILL STILL BE LOOKING AT HEIGHTS WELL ABOVE
NORMAL...AND IT WILL STILL BE PLENTY IN CONTROL TO PROTECT OUR
REGION FROM ANY MID/UPPER LEVEL SYNOPTIC FORCING FOR LIFT. THE
CHANGE IN PATTERN THAT WE WILL SEE FOR SUNDAY WILL OCCUR IN THE
VERY LOWEST LEVELS OF THE COLUMN. A WEAK INVERTED TROUGH SEEN
CURRENTLY OUT TOWARD THE BAHAMAS IS SHOWN BY MOST ENSEMBLE MEMBERS
TO MIGRATE WESTWARD THROUGH THE NEXT 24 HOURS TO A POSITION OVER
THE SOUTHERN HALF OF THE FL PENINSULA SUNDAY AFTERNOON. A SLIGHT
INCREASE IN COLUMN MOISTURE BELOW 700MB IS FORECAST TO ARRIVE WITH
THIS FEATURE...ALONG A SWATH OF MODEST ISENTROPIC UPGLIDE ALONG
THE 300-310K SURFACES. EXTENT OF LIFT (ALTHOUGH IT IS SHALLOW)
COMBINED WITH THE ADDED SURFACE FOCUS UNDER THE TROUGH APPEARS
SUFFICIENT TO SUPPORT SOME WIDELY SCATTERED LIGHT SHOWERS TO THE
SOUTH OF THE I-4 CORRIDOR SUNDAY AFTERNOON/EARLY EVENING. AS
MENTIONED ALL THE MOISTURE IS SHALLOW...AND HENCE THE SHOWERS WILL
ALSO BE SHALLOW AND LIGHT...WITH PROB ONLY A COUPLE HUNDREDTHS OF
AN INCH FOR ANY LOCATION THAT DOES SEE A BRIEF SHOWER.
THEREFORE...THE IMPACT TO ANY OUTDOOR ACTIVITIES LOOKS NEGLIGIBLE.
THE SOUTHERN HALF OF THE AREA SHOULD CERTAINLY EXPECT TO SEE LESS
SUN FOR SUNDAY AS A COMBINATION OF CUMULUS AND STRATOCU ARE LIKELY
TO FILL IN QUITE QUICKLY. CURRENT GRIDS HAVE 20-30% SHOWER
COVERAGE...AND BASED ON AVAILABLE 12Z GUIDANCE DO NOT SEE MUCH
REASON TO MAKE MANY SIGNIFICANT CHANGES WITH THIS FORECAST
PACKAGE.
&&
.AVIATION...
VFR CONDITIONS WILL PREVAIL THROUGH THE AFTERNOON AND EVENING
HOURS TODAY ACROSS WEST-CENTRAL AND SOUTHWEST FLORIDA. EASTERLY
TERMINALS WILL SEE EASTERLY WINDS AND A FEW-SCT CUMULUS FIELD
DEVELOPING DURING THE AFTERNOON. POTENTIAL FOR PATCHY AREAS OF FOG
TO IMPACT SITES SUCH AS KLAL/KPGD AFTER 08Z TONIGHT...HOWEVER...
BETTER CHANCES FOR FOG AND ASSOCIATED RESTRICTIONS LOOK TO REMAIN
NORTH OF THE FORECAST TERMINALS. EARLY FOG LIFTS BY 14Z...FOLLOWED
BY VFR CONDITIONS THROUGH SUNDAY AFTERNOON.
&&
.MARINE...
HIGH PRESSURE TO THE NORTH OF THE COASTAL WATERS WILL
KEEP MODERATE EAST WINDS IN PLACE THROUGH THE WEEKEND. A COLD
FRONT WILL APPROACH THE AREA AND STALL OVER THE NORTHEAST GULF
OF MEXICO DURING THE EARLY PART OF NEXT WEEK. CHANCES FOR SHOWERS
WILL INCREASE MONDAY INTO TUESDAY ASSOCIATED WITH THIS FRONT.
WINDS AND SEAS ARE GENERALLY EXPECTED TO REMAIN BELOW HEADLINE
CRITERIA.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 82 67 81 68 / 0 0 10 10
FMY 84 67 82 70 / 0 0 30 20
GIF 81 66 82 68 / 0 10 20 20
SRQ 81 66 81 69 / 0 0 20 10
BKV 83 64 83 67 / 0 0 10 10
SPG 81 67 80 70 / 0 0 10 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH MONDAY EVENING FOR COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE...MROCZKA
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
501 PM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL BRING A CHANCE OF SHOWERS LATE SUNDAY NIGHT AND
MONDAY. ANOTHER STRONGER COLD FRONT MAY BRING SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
FOG MAY OCCUR AGAIN LATE TONIGHT. THERE WAS AGREEMENT BETWEEN
THE MODELS THAT AT LEAST PATCHY FOG WILL OCCUR. THE HRRR SUGGESTED
THE THICKEST AREAS OF FOG WILL OCCUR FROM LANCASTER COUNTY INTO
THE CENTRAL MIDLANDS. DEEPER LOW-LEVEL MOISTURE PROFILES COMPARED
TO LAST NIGHT SUPPORTED THE HRRR. CALM WINDS WITH DRY AIR ALOFT
SHOULD AID STRONG NET RADIATIONAL COOLING. THE GUIDANCE CONSENSUS
SUPPORTED LOWS IN THE UPPER 40S AND LOWER 50S.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
THE NAM AND RAP SHOWED WEAK ISENTROPIC LIFT ALONG THE SOUTHERN SC
COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN AS THEY MOVE
INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL MIDLANDS. FOG AND
LOW STRATUS SHOULD DISSIPATE BY LATE SUNDAY MORNING. HIGHLY
AMPLIFIED UPPER PATTERN TO PERSIST. THE UPPER-LEVEL RIDGE AND
SURFACE HIGH PRESSURE WILL MOVE OFF THE COAST SUNDAY AS AN UPPER
LOW LIFTS NORTHEAST FROM THE GREAT PLAINS INTO THE CENTRAL MS
RIVER VALLEY. INCREASING DEEP SOUTHERLY FLOW/ISENTROPIC LIFT TO
DEVELOP OVER OUR REGION AHEAD OF AN APPROACHING WEAK FRONT. MODELS
INDICATE MORE CLOUDINESS SUNDAY. MOISTURE WILL CONTINUE TO
INCREASE SUNDAY NIGHT WITH PWAT AROUND ONE INCH WITH H85 WINDS
REACHING BETWEEN 30 AND 40 KTS BY LATE SUNDAY NIGHT. KEPT THE
CHANCE FOR SHOWERS LATE SUNDAY NIGHT. NEAR RECORD HIGH TEMPS
POSSIBLE SUNDAY. WILL CONTINUE TO USE WARMER GUIDANCE TEMPERATURES
WITH AFTERNOON HIGHS IN THE MID/UPPER 70S AND LOWS SUNDAY NIGHT
AROUND 60.
WEAK FRONT WILL MOVE THROUGH MONDAY AFTERNOON INTO THE EARLY
EVENING. UPPER ENERGY WILL BE WELL TO OUR NORTH WITH SOUTHWEST
FLOW ALOFT. ASSOCIATED CONVECTION TO OUR WEST ALONG THE FRONT
EXPECTED TO WEAKEN AS IT APPROACHES OUR REGION AS BEST UPPER
DYNAMICS SHIFT TO THE NORTH. SURFACE AND ELEVATED INSTABILITIES
STILL PROGGED TO BE WEAK...PRECLUDING THE MENTION OF THUNDER.
WE KEPT HIGH CHANCE TO LIKELY POPS WITH PRECIP AMOUNTS ONE QUARTER
INCH OR LESS. SHOWERS WILL MOVE EAST OF THE AREA MONDAY EVENING.
SHOULD SEE HIGHS IN THE 70S WITH LOWS MONDAY NIGHT IN THE MID 40S
WEST TO LOWER 50S EAST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS TRENDING TOWARDS STALLING THE FRONT JUST TO OUR SOUTH TUESDAY
WITH SURFACE HIGH PRESSURE RETURNING TO THE AREA. TEMPERATURES TO
REMAIN ABOVE NORMAL WITH A SOUTHWEST UPPER FLOW AND UPPER-LEVEL
RIDGE OVER THE EASTERN CONUS.
SURFACE HIGH PRESSURE AND UPPER RIDGING MOVES OFF THE COAST WEDNESDAY
WITH MOISTURE RETURNING FROM THE SOUTH. THE CHANCE FOR SHOWERS RETURN
WEDNESDAY AS MOISTURE OVERRUNS THE STALLED FRONT TO OUR SOUTH.
A STRONGER COLD FRONT CROSSES THE AREA THURSDAY...CONTINUING THE
CHANCE FOR SHOWERS. THE GFS PUSHES THE COLD FRONT OFF THE COAST BY
FRIDAY...ENDING THE CHANCE FOR SHOWERS. THE ECMWF DOES NOT MOVE
THE FRONT OFF THE COAST UNTIL FRIDAY EVENING...THEREFORE HOLDING
THE CHANCE FOR SHOWERS ACROSS THE AREA FRIDAY. THIS PATTERN LOOKS
MORE PROGRESSIVE...SO WE INDICATED A DRY FORECAST FRIDAY.
THE MODELS INDICATE THE BREAK DOWN OF THE PERSISTENT SOUTHEASTERN U.S.
RIDGE BY THE END OF NEXT WEEK. THIS WILL BRING LOWER
HEIGHTS/THICKNESSES TO THE EASTERN SEABOARD AND AN END TO THE
MILD WEATHER. DRY WEATHER AND MORE SEASONABLE TEMPERATURES ARE FORECAST
FRIDAY AND SATURDAY.
&&
.AVIATION /22Z SATURDAY THROUGH THURSDAY/...
RESTRICTIONS DUE TO FOG AND LOW STRATUS APPEAR LIKELY OVERNIGHT
AND EARLY SUNDAY MORNING.
MODELS ARE COMING TO BETTER AGREEMENT ON FOG DEVELOPMENT
OVERNIGHT. GFS AND NAM GUIDANCE SUGGESTS AT LEAST MVFR FOG TONIGHT
INTO SUNDAY MORNING. HI-RES MODELS INDICATE THAT DENSE FOG MAY BE
MOST LIKELY IN THE NORTHERN HALF OF THE FORECAST AREA. FORECAST
PROFILES SUPPORT THIS SHOWING DEEPER LOW LEVEL MOISTURE THAN LAST
NIGHT FROM LANCASTER INTO THE CENTRAL MIDLANDS. CALM WINDS...DRY
MID LEVELS AND CLEAR SKIES SHOULD AID RADIATIONAL COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. MVFR CEILING RESTRICTIONS APPEAR PROBABLE AT OGB AND
POSSIBLE AT OTHER TAF SITES.
EXTENDED AVIATION OUTLOOK...A COLD FRONT MOVING INTO THE AREA
MAY BRING RESTRICTIONS WEDNESDAY THROUGH THURSDAY.
&&
.CLIMATE...
NORMAL MAX TEMPS SUNDAY...
CAE...59. AGS...60.
RECORD MAX TEMPS SUNDAY...
CAE...80.
AGS...81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
244 PM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER STRONGER COLD FRONT TO BRING A CHANCE OF
SHOWERS WEDNESDAY AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONTINUED SOUTHERLY FLOW AND WARM ADVECTION WILL SUPPORT WELL
ABOVE NORMAL TEMPERATURES THIS AFTERNOON. HIGHS FROM THE MID TO
UPPER 70S ARE NEARLY 20 DEGREES ABOVE NORMAL. SOME LOCATIONS MAY
NEAR RECORD VALUES...HOWEVER RECORD HIGHS ARE NOT EXPECTED TO BE
BROKEN TODAY. NO CHANCE FOR RAIN UNDER THE UPPER RIDGE WITH HIGH
PRESSURE IN CONTROL.
TONIGHT...FOG WILL BE POSSIBLE AGAIN TONIGHT INTO EARLY SUNDAY
MORNING. THERE IS GOOD AGREEMENT BETWEEN MODELS THAT AT LEAST
PATCHY FOG WILL OCCUR. THE HRRR SUGGESTS THAT THE THICKEST AREAS
OF FOG WILL OCCUR FROM LANCASTER COUNTY INTO THE CENTRAL MIDLANDS.
DEEPER LO-LEVEL MOISTURE PROFILES THAN LAST NIGHT SUPPORT THE
HRRR. CALM WINDS...DRY MID-LEVELS AND CLEAR SKIES SHOULD AID
RADIATIONAL COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. FOG AND LOW STRATUS MAY DISSIPATE BY LATE SUNDAY
MORNING.
TEMPS...LOW TEMPERATURES WILL BE IN THE 50S TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
HIGHLY AMPLIFIED UPPER PATTERN TO PERSIST. THE UPPER LEVEL RIDGE AND
SURFACE HIGH PRESSURE WILL MOVE OFF THE COAST SUNDAY AS AN UPPER LOW
LIFTS NORTHEAST FROM THE GREAT PLAINS INTO THE CENTRAL MS RIVER VALLEY.
INCREASING DEEP SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR
REGION AHEAD OF AN APPROACHING WEAK FRONT. MODELS INDICATE MORE
CLOUDINESS SUNDAY. MOISTURE WILL CONTINUE TO INCREASE SUNDAY NIGHT
WITH PWAT AROUND ONE INCH AND H85 WINDS REACHING BETWEEN 30-40 KTS
BY LATE SUNDAY NIGHT. KEPT THE CHANCE FOR SHOWERS LATE SUNDAY
NIGHT. NEAR RECORD HIGH TEMPS POSSIBLE SUNDAY. WILL CONTINUE TO
USE WARMER GUIDANCE TEMPERATURES WITH AFTERNOON HIGHS IN THE
MID/UPPER 70S AND LOWS SUNDAY NIGHT AROUND 60.
WEAK FRONT WILL MOVE THROUGH MONDAY AFTERNOON INTO THE EARLY
EVENING. UPPER ENERGY WILL BE WELL TO OUR NORTH WITH SOUTHWEST
FLOW ALOFT. ASSOCIATED CONVECTION TO OUR WEST ALONG THE FRONT
EXPECTED TO WEAKEN AS IT APPROACHES OUR REGION AS BEST UPPER
DYNAMICS SHIFT TO THE NORTH. SURFACE AND ELEVATED INSTABILITIES
STILL PROGGED TO BE WEAK...PRECLUDING THE MENTION OF THUNDER.
WE KEPT HIGH CHANCE TO LIKELY POPS WITH PRECIP AMOUNTS ONE QUARTER
INCH OR LESS. SHOWERS WILL MOVE EAST OF THE AREA MONDAY EVENING.
SHOULD SEE HIGHS IN THE 70S WITH LOWS MONDAY NIGHT IN THE MID 40S
WEST TO LOWER 50S EAST.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
MODELS TRENDING TOWARDS STALLING THE FRONT JUST TO OUR SOUTH TUESDAY
WITH SURFACE HIGH PRESSURE RETURNING TO THE AREA. TEMPERATURES TO
REMAIN ABOVE NORMAL WITH A SOUTHWEST UPPER FLOW AND UPPER LEVEL
RIDGE OVER THE EASTERN CONUS.
SURFACE HIGH PRESSURE AND UPPER RIDGING MOVES OFF THE COAST WEDNESDAY
WITH MOISTURE RETURNING FROM THE SOUTH. THE CHANCE FOR SHOWERS RETURN
WEDNESDAY AS MOISTURE OVERRUNS THE STALLED FRONT TO OUR SOUTH.
A STRONGER COLD FRONT CROSSES THE AREA THURSDAY...CONTINUING THE
CHANCE FOR SHOWERS. THE GFS PUSHES THE COLD FRONT OFF THE COAST BY
FRIDAY...ENDING THE CHANCE FOR SHOWERS. THE ECMWF DOES NOT MOVE
THE FRONT OFF THE COAST UNTIL FRIDAY EVENING...THEREFORE HOLDING
THE CHANCE FOR SHOWERS ACROSS THE AREA FRIDAY. THIS PATTERN LOOKS
MORE PROGRESSIVE...SO WE INDICATED A DRY FORECAST FRIDAY.
THE MODELS INDICATE THE BREAK DOWN OF THE PERSISTENT SOUTHEASTERN U.S.
RIDGE BY THE END OF NEXT WEEK. THIS WILL BRING LOWER
HEIGHTS/THICKNESSES TO THE EASTERN SEABOARD AND AN END TO THE
MILD WEATHER. DRY WEATHER AND MORE SEASONABLE TEMPERATURES ARE FORECAST
FRIDAY AND SATURDAY.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
RESTRICTIONS DUE TO FOG AND LOW STRATUS APPEAR LIKELY OVERNIGHT
AND EARLY SUNDAY MORNING.
MOSTLY CLEAR SKIES TODAY WITH DRY HIGH PRESSURE OVERHEAD. WINDS
WILL BE LIGHT AND VARIABLE MOST OF THE DAY...PARTICULARLY IN THE
CSRA.
TONIGHT...MODELS ARE COMING TO BETTER AGREEMENT ON FOG
DEVELOPMENT OVERNIGHT. GFS AND NAM GUIDANCE SUGGESTS AT LEAST MVFR
FOG TONIGHT INTO SUNDAY MORNING. HI-RES MODELS INDICATE THAT
DENSE FOG MAY BE MOST LIKELY IN THE NORTHERN HALF OF THE FORECAST
AREA. FORECAST PROFILES SUPPORT THIS SHOWING DEEPER LOW LEVEL
MOISTURE THAN LAST NIGHT FROM LANCASTER INTO THE CENTRAL MIDLANDS.
CALM WINDS...DRY MID-LEVELS AND CLEAR SKIES SHOULD AID RADIATIONAL
COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. MVFR CEILING RESTRICTIONS APPEAR PROBABLE AT OGB AND
POSSIBLE AT OTHER TAF SITES.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
NORMAL MAX TEMPS SUNDAY...
CAE...59. AGS...60.
RECORD MAX TEMPS SUNDAY...
CAE...80.
AGS...81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1249 PM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER FRONT TO PROVIDE A CHANCE OF SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
CONTINUED SOUTHERLY FLOW AND WARM ADVECTION WILL SUPPORT WELL
ABOVE NORMAL TEMPERATURES THIS AFTERNOON. HIGHS FROM THE MID TO
UPPER 70S ARE NEARLY 20 DEGREES ABOVE NORMAL. SOME LOCATIONS MAY
NEAR RECORD VALUES...HOWEVER RECORD HIGHS ARE NOT EXPECTED TO BE
BROKEN TODAY. NO CHANCE FOR RAIN UNDER THE UPPER RIDGE WITH HIGH
PRESSURE IN CONTROL.
TONIGHT...FOG WILL BE POSSIBLE AGAIN TONIGHT INTO EARLY SUNDAY
MORNING. THERE IS GOOD AGREEMENT BETWEEN MODELS THAT AT LEAST
PATCHY FOG WILL OCCUR. THE HRRR SUGGESTS THAT THE THICKEST AREAS
OF FOG WILL OCCUR FROM LANCASTER COUNTY INTO THE CENTRAL MIDLANDS.
DEEPER LO-LEVEL MOISTURE PROFILES THAN LAST NIGHT SUPPORT THE
HRRR. CALM WINDS...DRY MID-LEVELS AND CLEAR SKIES SHOULD AID
RADIATIONAL COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. FOG AND LOW STRATUS MAY DISSIPATE BY LATE SUNDAY
MORNING.
TEMPS...LOW TEMPERATURES WILL BE IN THE 50S TONIGHT.
&&
.SHORT TERM /SUNDAY THROUGH SUNDAY NIGHT/...
CONTINUED FAIR WEATHER WITH WELL ABOVE NORMAL TEMPS. FOG POSSIBLE
AGAIN LATE TONIGHT/EARLY SUNDAY...BUT AN INCREASE IN LOW LEVEL
SOUTHERLY FLOW LATE TONIGHT COULD PROVIDE MORE OF A STRATUS
THREAT. UPPER/SURFACE HIGHS TO SHIFT TO OUR EAST SUN/SUN NT...AS
UPPER TROUGH TO OUR WEST LIFTS NE TOWARDS THE MID/UPPER MISS
VALLEY. NEAR RECORD HIGH TEMPS POSSIBLE SUNDAY. INCREASING LOW
LEVEL SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR REGION
LATE SUNDAY NIGHT AHEAD OF AN APPROACHING WEAK FRONT...WITH SOME
LIGHT PRECIP POSSIBLE.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
WEAK FRONT WILL MOVE THROUGH MONDAY. LATEST MODELS TRENDING
TOWARDS SLOWING DOWN THE TIMING OF THE FRONT AS UPPER ENERGY IS
WELL TO THE NORTH BY THAT TIME...WITH A SW FLOW ALOFT. ASSOCIATED
PRECIP ACTIVITY/CONVECTION TO OUR WEST ALONG THE FRONT EXPECTED TO
WEAKEN AS IT APPROACHES OUR REGION AS BEST UPPER DYNAMICS SHIFT TO
THE NORTH. SURFACE AND ELEVATED INSTABILITIES STILL PROGGED TO BE
WEAK FOR OUR FA...PRECLUDING NEED FOR THUNDER MENTION AT THIS
TIME FOR OUR FA. HIGH CHANCE TO LOW LIKELY POPS CONTINUE TO LOOK
OK WITH THE FROPA. WITH FROPA TRENDING LATER IN THE DAY...BUMPED
UP MAX TEMPS MON. MODELS TRENDING TOWARDS STALLING THE FRONT JUST
TO OUR SOUTH TUE. WILL MAINTAIN FAIR WEATHER FORECAST FOR TUE.
STILL ABOVE NORMAL TEMPS EXPECTED TUE AS A SW UPPER FLOW REMAINS
WITH FLAT UPPER RIDGE OVER THE E COAST. LATEST GFS/ECWMF APPEAR TO
BE IN GOOD AGREEMENT WITH UPPER TROUGH MOVING EAST INTO THE
CENTRAL CONUS...WITH UPPER RIDGE SHIFTING TO OUR EAST...BY
WED/THU...BRINGING MAIN UPPER FLOW CLOSER TO OUR REGION WITH
EMBEDDED ENERGY LEADING TO MOISTURE RETURN ANTICIPATED FOR LATE
WED INTO EARLY FRI. FOR NOW...CHANCE POPS APPEAR OK.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
RESTRICTIONS DUE TO FOG AND LOW STRATUS APPEAR LIKELY OVERNIGHT
AND EARLY SUNDAY MORNING.
MOSTLY CLEAR SKIES TODAY WITH DRY HIGH PRESSURE OVERHEAD. WINDS
WILL BE LIGHT AND VARIABLE MOST OF THE DAY...PARTICULARLY IN THE
CSRA.
TONIGHT...MODELS ARE COMING TO BETTER AGREEMENT ON FOG
DEVELOPMENT OVERNIGHT. GFS AND NAM GUIDANCE SUGGESTS AT LEAST MVFR
FOG TONIGHT INTO SUNDAY MORNING. HI-RES MODELS INDICATE THAT
DENSE FOG MAY BE MOST LIKELY IN THE NORTHERN HALF OF THE FORECAST
AREA. FORECAST PROFILES SUPPORT THIS SHOWING DEEPER LOW LEVEL
MOISTURE THAN LAST NIGHT FROM LANCASTER INTO THE CENTRAL MIDLANDS.
CALM WINDS...DRY MID-LEVELS AND CLEAR SKIES SHOULD AID RADIATIONAL
COOLING.
THE NAM AND RAP MODELS SHOW WEAK ISENTROPIC LIFT ALONG THE
SOUTHERN SC COAST SUNDAY MORNING. LOW STRATUS MAY BE A CONCERN
AS THEY MOVE INTO THE EASTERN MIDLANDS AND EVENTUALLY CENTRAL
MIDLANDS. MVFR CEILING RESTRICTIONS APPEAR PROBABLE AT OGB AND
POSSIBLE AT OTHER TAF SITES.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
CURRENT INDICATIONS ARE THAT MAX TEMPS TODAY WILL NOT BREAK DAILY
RECORD HIGHS...BUT RECORD HIGH TEMPS MAY POSSIBLY BE REACHED
SUNDAY.
NORMAL MAX TEMPS TODAY/SUNDAY...
CAE...59/59. AGS...61/60.
FORECAST MAX TEMPS TODAY/SUNDAY...
CAE...77/78. AGS...78/80.
RECORD MAX TEMPS TODAY/SUNDAY...
CAE...81/80. AGS...82/81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
134 AM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER FRONT TO PROVIDE A CHANCE OF SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
THE SURFACE PRESSURE RIDGE AXIS WILL REMAIN JUST SOUTH OF THE
FORECAST AREA THROUGH TONIGHT. FLAT UPPER RIDGING WILL CONTINUE
AND SATELLITE TRENDS INDICATE THIN CIRRUS WILL CONTINUE SPILLING
OVER THE RIDGE AND INTO THE FORECAST AREA. SHALLOW LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING WILL HELP CAUSE AREAS OF FOG DURING
THE EARLY MORNING HOURS. THE LAMP GUIDANCE SUGGESTED WIDESPREAD
FOG BUT OTHER MODELS WERE LESS AGGRESSIVE. THE HRRR INDICATED FOG
MAINLY TO THE WEST OF THE FORECAST AREA BUT THE TREND IN THE HRRR
HAS BEEN MORE FOG COVERAGE. WE HAVE INCLUDED FOG IN THE FORECAST
THROUGH THE EARLY MORNING. A DENSE FOG ADVISORY MAY BE NEEDED.
LOWS NEAR OR JUST ABOVE 50 DEGREES ARE EXPECTED.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
UPPER AND SURFACE HIGHS OVER THE REGION TONIGHT INTO EARLY
SUNDAY. CONTINUED FAIR WEATHER WITH WELL ABOVE NORMAL TEMPS. FOG
POSSIBLE AGAIN LATE TONIGHT/EARLY SUNDAY...BUT AN INCREASE IN LOW
LEVEL SOUTHERLY FLOW LATE TONIGHT COULD PROVIDE MORE OF A STRATUS
THREAT. UPPER/SURFACE HIGHS TO SHIFT TO OUR EAST SUN/SUN NT...AS
UPPER TROUGH TO OUR WEST LIFTS NE TOWARDS THE MID/UPPER MISS
VALLEY. NEAR RECORD HIGH TEMPS POSSIBLE SUNDAY. INCREASING LOW
LEVEL SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR REGION
LATE SUNDAY NIGHT AHEAD OF AN APPROACHING WEAK FRONT...WITH SOME
LIGHT PRECIP POSSIBLE.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
WEAK FRONT WILL MOVE THROUGH MONDAY. LATEST MODELS TRENDING
TOWARDS SLOWING DOWN THE TIMING OF THE FRONT AS UPPER ENERGY IS
WELL TO THE NORTH BY THAT TIME...WITH A SW FLOW ALOFT. ASSOCIATED
PRECIP ACTIVITY/CONVECTION TO OUR WEST ALONG THE FRONT EXPECTED TO
WEAKEN AS IT APPROACHES OUR REGION AS BEST UPPER DYNAMICS SHIFT TO
THE NORTH. SURFACE AND ELEVATED INSTABILITIES STILL PROGGED TO BE
WEAK FOR OUR FA...PRECLUDING NEED FOR THUNDER MENTION AT THIS
TIME FOR OUR FA. HIGH CHANCE TO LOW LIKELY POPS CONTINUE TO LOOK
OK WITH THE FROPA. WITH FROPA TRENDING LATER IN THE DAY...BUMPED
UP MAX TEMPS MON. MODELS TRENDING TOWARDS STALLING THE FRONT JUST
TO OUR SOUTH TUE. WILL MAINTAIN FAIR WEATHER FORECAST FOR TUE.
STILL ABOVE NORMAL TEMPS EXPECTED TUE AS A SW UPPER FLOW REMAINS
WITH FLAT UPPER RIDGE OVER THE E COAST. LATEST GFS/ECWMF APPEAR TO
BE IN GOOD AGREEMENT WITH UPPER TROUGH MOVING EAST INTO THE
CENTRAL CONUS...WITH UPPER RIDGE SHIFTING TO OUR EAST...BY
WED/THU...BRINGING MAIN UPPER FLOW CLOSER TO OUR REGION WITH
EMBEDDED ENERGY LEADING TO MOISTURE RETURN ANTICIPATED FOR LATE
WED INTO EARLY FRI. FOR NOW...CHANCE POPS APPEAR OK.
&&
.AVIATION /07Z SATURDAY THROUGH WEDNESDAY/...
WEAK HIGH PRESSURE REMAINS ANCHORED OVER THE REGION. SOME
SCATTERED CIRRUS EXPECTED TO CONTINUE TO MOVE OVER THE AREA
THROUGH THE PERIOD...SPILLING OVER THE TOP OF A BUILDING UPPER
RIDGE AXIS TO THE WEST.
STRONG RADIATIONAL COOLING CONDITIONS IN PLACE UNDER MOSTLY CLEAR
SKIES AND CALM WINDS WITH PLENTY OF MID LEVEL DRY AIR IN PLACE HAS
LED TO SEVERAL AIRPORTS ALREADY REPORTING RESTRICTIONS DUE TO FOG.
SATELLITE IMAGERY SHOWS SOME 4-6 KFT CLOUDS MOVING THROUGH THE
UPSTATE AND INTO THE NORTHWESTERN MIDLANDS AS OF 06Z. THESE
CLOUDS COULD IMPACT THE FOG POTENTIAL BUT ARE EXPECTED TO BE
TEMPORARY. WILL CARRY LIFR CONDITIONS AGS/OGB DUE TO FOG TO START
THE FORECAST PERIOD WHILE CAE/CUB/DNL START VFR/MVFR AND GRADUALLY
LOWER DURING THE 08Z-10Z TIME FRAME WHERE DENSE FOG IS EXPECTED TO
DEVELOP ACROSS MOST TERMINALS EXCEPT MAYBE DNL.
FOG WILL LIKELY LINGER THROUGH 13-14Z BEFORE CONDITIONS RETURN TO
VFR AS HEATING AND MIXING SHOULD RESULT IN A RETURN TO VFR
CONDITIONS BEGINNING AROUND 14Z. LIGHT WEST TO SOUTHWESTERLY WINDS
DEVELOPING BY 15Z. NO CHANCES OF RAIN WITH BUILDING UPPER RIDGE
AND SURFACE HIGH PRESSURE IN PLACE.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
CURRENT INDICATIONS ARE THAT MAX TEMPS TODAY WILL NOT BREAK DAILY
RECORD HIGHS...BUT RECORD HIGH TEMPS MAY POSSIBLY BE REACHED
SUNDAY.
NORMAL MAX TEMPS TODAY/SUNDAY...
CAE...59/59. AGS...61/60.
FORECAST MAX TEMPS TODAY/SUNDAY...
CAE...77/78. AGS...78/80.
RECORD MAX TEMPS TODAY/SUNDAY...
CAE...81/80. AGS...82/81.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
106 AM EST SAT DEC 12 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER THROUGH SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER FRONT TO PROVIDE A CHANCE OF SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
THE SURFACE PRESSURE RIDGE AXIS WILL REMAIN JUST SOUTH OF THE
FORECAST AREA THROUGH TONIGHT. FLAT UPPER RIDGING WILL CONTINUE
AND SATELLITE TRENDS INDICATE THIN CIRRUS WILL CONTINUE SPILLING
OVER THE RIDGE AND INTO THE FORECAST AREA. SHALLOW LOW-LEVEL
MOISTURE AND NOCTURNAL COOLING WILL HELP CAUSE AREAS OF FOG DURING
THE EARLY MORNING HOURS. THE LAMP GUIDANCE SUGGESTED WIDESPREAD
FOG BUT OTHER MODELS WERE LESS AGGRESSIVE. THE HRRR INDICATED FOG
MAINLY TO THE WEST OF THE FORECAST AREA BUT THE TREND IN THE HRRR
HAS BEEN MORE FOG COVERAGE. WE HAVE INCLUDED FOG IN THE FORECAST
THROUGH THE EARLY MORNING. A DENSE FOG ADVISORY MAY BE NEEDED.
LOWS NEAR OR JUST ABOVE 50 DEGREES ARE EXPECTED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
DRY WEATHER AND ABOVE NORMAL TEMPERATURES WILL PERSIST SATURDAY
THROUGH SATURDAY NIGHT. UPPER RIDGE WILL REMAIN OVER THE
SOUTHEASTERN STATES...AS UPPER TROUGH/CLOSED LOW CROSSES THE
WESTERN CONUS. THIS WILL LEAD TO A CONTINUED WARMING TREND FOR
OUR REGION. SURFACE HIGH PRESSURE CENTERED OVER NORTHERN FLORIDA
WILL LIFT NORTH TOWARDS THE CAROLINAS SATURDAY. FAVORED WARMER
TEMPERATURES INDICATED BY THE MAV MOS WITH HIGHS IN THE MID TO
UPPER 70S AND LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
THE UPPER-LEVEL RIDGE AND SURFACE HIGH PRESSURE WILL MOVE OFF THE
COAST SUNDAY AS AN UPPER LOW LIFTS NORTHEAST FROM THE GREAT PLAINS
INTO THE GREAT LAKES REGION SUNDAY INTO MONDAY. THIS WILL DRAG A
FRONTAL BOUNDARY THROUGH THE FORECAST AREA MONDAY. PRECIPITATION
TO OUR WEST ALONG THE FRONT EXPECTED TO WEAKEN AS IT APPROACHES
OUR REGION AS BEST UPPER DYNAMICS SHIFT TO THE NORTH. INCREASING
LOW-LEVEL SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR
REGION LATE SUNDAY NIGHT AHEAD OF THE APPROACHING WEAK FRONT.
SURFACE AND ELEVATED INSTABILITIES PROGGED TO BE QUITE WEAK ACROSS
THE MIDLANDS AND CSRA...THUS NO MENTION OF THUNDER.
HIGH CHANCE TO LOW LIKELY POPS CONTINUE WITH THE FRONTAL PASSAGE
MONDAY. DRY HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY NIGHT
INTO TUESDAY. ABOVE NORMAL TEMPS WILL CONTINUE TUESDAY GIVEN
SOUTHWEST FLOW ALOFT WITH WEAK UPPER RIDGING OVER THE SOUTHEASTERN
STATES.
GFS/ECMWF IN AGREEMENT WITH UPPER TROUGH MOVING EAST INTO THE
CENTRAL CONUS...WITH UPPER RIDGE SHIFTING TO OUR EAST WEDNESDAY.
SURFACE FRONT PROGGED TO CROSS THE AREA THURSDAY. STILL SOME
TIMING DIFFERENCES WITH THE GFS INDICATING THE FROPA THURSDAY AND
THE ECMWF SLOWER...INDICATING THE FRONT MOVING EAST OF THE AREA
FRIDAY. INCREASING MOISTURE/ISENTROPIC LIFT AHEAD OF THE FRONT MAY
LEAD TO SOME LIGHT PRECIP WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT.
GIVEN MODEL DIFFERENCES WILL KEEP CHANCE OF SHOWERS THURSDAY INTO
FRIDAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH
THURSDAY...COOLING TO THE 50S FOR FRIDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
WEAK HIGH PRESSURE REMAINS ANCHORED OVER THE REGION. SOME
SCATTERED CIRRUS EXPECTED TO CONTINUE TO MOVE OVER THE AREA
THROUGH THE PERIOD...SPILLING OVER THE TOP OF A BUILDING UPPER
RIDGE AXIS TO THE WEST.
STRONG RADIATIONAL COOLING CONDITIONS IN PLACE UNDER MOSTLY CLEAR
SKIES AND CALM WINDS WITH PLENTY OF MID LEVEL DRY AIR IN PLACE HAS
LED TO SEVERAL AIRPORTS ALREADY REPORTING RESTRICTIONS DUE TO FOG.
SATELLITE IMAGERY SHOWS SOME 4-6 KFT CLOUDS MOVING THROUGH THE
UPSTATE AND INTO THE NORTHWESTERN MIDLANDS AS OF 06Z. THESE
CLOUDS COULD IMPACT THE FOG POTENTIAL BUT ARE EXPECTED TO BE
TEMPORARY. WILL CARRY LIFR CONDITIONS AGS/OGB DUE TO FOG TO START
THE FORECAST PERIOD WHILE CAE/CUB/DNL START VFR/MVFR AND GRADUALLY
LOWER DURING THE 08Z-10Z TIME FRAME WHERE DENSE FOG IS EXPECTED TO
DEVELOP ACROSS MOST TERMINALS EXCEPT MAYBE DNL.
FOG WILL LIKELY LINGER THROUGH 13-14Z BEFORE CONDITIONS RETURN TO
VFR AS HEATING AND MIXING SHOULD RESULT IN A RETURN TO VFR
CONDITIONS BEGINNING AROUND 14Z. LIGHT WEST TO SOUTHWESTERLY WINDS
DEVELOPING BY 15Z. NO CHANCES OF RAIN WITH BUILDING UPPER RIDGE
AND SURFACE HIGH PRESSURE IN PLACE.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
FORECAST MAX TEMPS SAT/SUN
CAE...77/79
AGS...78/79
NORMAL MAX TEMPS SAT/SUN
CAE...59/59
AGS...61/60
RECORD MAX TEMPS SAT/SUN
CAE...81/80
AGS...82/81
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
412 PM CST SAT DEC 12 2015
.SHORT TERM...
325 PM CST
THROUGH SUNDAY...
A VERY SEASONALLY ANOMALOUS WEATHER PATTERN WITH MANY FORECAST
CHALLENGES...RANGING FROM RECORD OR NEAR RECORD HIGH
TEMPERATURES...DENSE FOG...ISOLATED THUNDERSTORMS...AND THE
BEGINNINGS OF HEAVY RAIN.
FOR THE REMAINDER OF THE AFTERNOON...THE PROGRESSION OF A STRONG
WARM FRONT THROUGH THE NORTHERN PORTIONS OF THE FORECAST AREA INTO
SOUTHERN WISCONSIN WILL BE THE MAIN DRIVER OF TEMPERATURE TRENDS AND
DENSE FOG. AS OF 3PM CST...STILL OBSERVING DENSE FOG WHERE WINDS
ARE STILL EASTERLY. A LAKE BREEZE HAS ALLOWED FOR SOME OF THE DENSE
FOG OVER LAKE MICHIGAN TO MOVE INLAND INTO LAKE AND COOK COUNTIES
NEAR THE LAKEFRONT AND EXPECT THAT THE DENSE FOG MAY STILL PUSH
INLAND TO ARND THE I-94 CORRIDOR. THE LAKE WILL IMPEDE THE NWD
PROGRESSION OF THE FRONT...ESPECIALLY OVER FAR NERN IL...WHILE LOW
PRESSURE TROUGHING OVER THE MISSOURI VALLEY WILL HELP WINDS OVER
NCNTRL/NWRN IL TURN MORE SOUTHERLY...PUSHING THE WARM FRONT NWD INTO
WISCONSIN OVER THAT AREA.. SO...EXPECT NCNTRL NWRN IL TO SEE
IMPROVING VISIBILITY THROUGH THE EVENING. ALSO...WARMER AIR WILL
CONTINUE TO STREAM NWD ACROSS THE AREA AND TEMPERATURES WILL LIKELY
CONTINUE TO SLOWLY RISE THROUGH THE EVENING BEFORE LEVELING OFF
OVERNIGHT. THERE SHOULD BE LITTLE OR NO DIURNAL COOLING OVERNIGHT
TONIGHT. TEMPERATURES AND DEWPOINTS SHOULD SLOWLY...BUT STEADILY
RISE THROUGH THE EVENING...ESPECIALLY SOUTH OF THE I-88 CORRIDOR.
LOCATIONS SOUTH OF I-80 SHOULD SEE OVERNIGHT TEMPERATURES RISE INTO
THE LOWER 60S BEFORE LEVELING OFF AND LOCATIONS BTWN I-88 AND I-80
SHOULD SEE TEMPS OVERNIGHT IN THE UPPER 50S. FAR NERN IL...CLOSER
TO THE LAKE...WILL REMAIN COOLER AS WINDS SHOULD BE ONSHORE UNTIL
TOMORROW AFTERNOON...WHEN DEEPENING LOW PRESSURE MOVES INTO THE
MISSOURI VALLEY AND THE WARM FRONT SURGES INTO CENTRAL WISCONSIN.
AS THE SFC LOW GETS CLOSER TO THE AREA...FORECAST CONCERNS WILL
SHIFT TO WIND SPEEDS AND THE ONSET OF HEAVIER STEADY RAIN WITH THE
POTENTIAL FOR SOME ISOLATED THUNDERSTORMS. THE LATEST GUIDANCE
SUGGESTS THAT THE AXIS OF HEAVIER RAIN SHOULD SET UP A LITTLE
FARTHER TO THE NORTHWEST THAN PREVIOUSLY ANTICIPATED...BUT STILL
EXPECT STEADY RAIN WITH CATEGORICAL POPS TO APPROACH THE I-39
CORRIDOR DURG THE PRE-DAWN HOURS. EXPECT THE RAIN TO SLOWLY SPREAD
TO THE EAST AND NOT REACH NWRN INDIANA UNTIL THE LATE AFTERNOON OR
EARLY EVENING HOURS. A STRONG SLY LOW LEVEL JET SETTING UP ALONG
THE BAROCLINIC ZONE OF THE COLD FRONT WILL MOVE ACROSS THE AREA
TOMORROW. SUSTAINED WINDS SHOULD STEADILY INCREASE THROUGH THE DAY
TOMORROW AS THE SLY PRESSURE GRADIENT STRENGTHENS AND LOW LEVEL
MIXING ARND RAIN AND ANY THUNDERSTORMS THAT DO MANAGE TO DEVELOP
WILL HELP MIX DOWN STRONGER WINDS FROM THE LOW LEVEL JET...WITH
FREQUENT GUSTS OF 30-35 MPH THROUGH THE DAY TOMORROW. THE LATEST
GUIDANCE IS INDICATING 50KT WINDS ASSOCIATED WITH THE LOW LEVEL
JET...SO OCNL HIGHER GUSTS WILL BE POSSIBLE AS WELL. WITH
PERSISTENT WARM...MOIST ADVECTION EXPECTED TO CONTINUE THROUGH THE
DAY TOMORROW...EXPECT THAT TEMPERATURES SHOULD APPROACH OR EXCEED
RECORD LEVELS...TOPPING OUT IN THE LOWER 60S NORTH OF THE ILLINOIS
OVER MUCH OF THE AREA...WITH TEMPS POSSIBLY PEGGING 65-66F OVER THE
FAR SRN PORTIONS OF THE CWA. THE ANOMALOUS WARMTH SHOULD PERSIST
WELL INTO SUNDAY EVENING...UNTIL THE STRONG COLD FRONT FINALLY
PUSHES THROUGH THE AREA.
KREIN
&&
.LONG TERM...
310 PM CST
SUNDAY NIGHT THROUGH SATURDAY...
THE PRIMARY SURFACE LOW WILL LIFT NORTHEAST ON SUNDAY NIGHT AND
DEEPEN AS IT DOES...FROM NEAR KANSAS CITY IN THE EVENING TO WESTERN
WISCONSIN BY MIDDAY MONDAY. MODEL GUIDANCE IS IN STRONG AGREEMENT
WITH THIS PATH. THE KEY RESULTS WILL BE A WINDY AND MILD SUNDAY
NIGHT...AN AXIS OR TWO OF EFFICIENT WARM SEASON-LIKE RAIN MOVING
OVER SUNDAY NIGHT...AND A WINDY...COOLER...AND SHOWERY MONDAY.
THIS DEEPENING TREND AND THE LOW PATH ON SUNDAY NIGHT WILL RESULT IN
PRESSURE FALLS ENVELOPING THE AREA AND A STOUT SOUTH WIND.
TEMPERATURES LOOK TO HOLD STEADY OR POSSIBLY EVEN RISE THROUGH THE
NIGHT ONCE AGAIN AS THE WARM SECTOR IS REINFORCED. DEW POINTS SHOULD
BE AROUND 60 DEGREES AS WELL...A REMARKABLE 25 DEGREES HIGHER THAN
OUR AVERAGE HIGH TEMPERATURE THIS TIME OF YEAR.
THE DIFFLUENCE ALOFT AND ASSOCIATED LARGE SCALE ASCENT LOOKS TO
SPREAD OVER NORTH CENTRAL ILLINOIS DURING SUNDAY EVENING AND ACROSS
THE ENTIRE AREA OVERNIGHT SUNDAY. PRECIPITABLE WATERS SHOULD BE IN
THE 1.40 INCH PLUS CATEGORY WHICH IS AT RECORD HIGHS FOR THE TIME OF
YEAR. THAT COMBINED WITH WARM CLOUD PROCESSES SHOULD ALLOW FOR
EFFICIENT RAIN PRODUCTION...ALTHOUGH THE STRONGEST FOCUS AT THE NOSE
OF THE 65 KT LOW-LEVEL JET LOOKS TO REMAIN JUST NORTHWEST OF THE
AREA. EVEN WITH THAT BEING THE CASE HAVE STILL GONE A LITTLE HIGHER
THAN A WPC/MODEL RAINFALL AMOUNT BLEND FOR NORTH CENTRAL ILLINOIS
SUNDAY EVENING. IT STILL LOOKS POSSIBLE THAT RAINFALL TOWARD THE
ROCKFORD AREA COULD REACH OR EVEN EXCEED ONE AND A HALF INCHES.
THUNDER POTENTIAL LOOKS SMALLER ACROSS THE REGION THAN
TONIGHT/SUNDAY MORNING DUE TO A HIGHLY SATURATED COLUMN AND MUSHY
LAPSE RATES.
HAVE TRENDED A BIT HIGHER WITH POPS FOR MONDAY AS THE THEME OF
SLOWER-IS-BETTER WITH THIS SYSTEM LOOKS TO BE VERIFYING INTO
MONDAY...ESPECIALLY THROUGH EARLY MONDAY AFTERNOON OR SO WITH THE
UPPER LOW AND WRAPAROUND MOISTURE STILL ACROSS THE AREA. ANY RAIN
SHOWERS SHOULD BECOME MORE SCATTERED INTO LATE IN THE DAY.
TEMPERATURES WILL TAKE A SHARP DROP MONDAY MORNING BUT SHOULD LEVEL
OUT IN THE MID 40S...STILL A WAYS ABOVE NORMAL. WINDS LOOK TO GUST
TO 30 TO 35 MPH AT TIMES DURING THE DAY ADDING A BITE TO THE AIR
ESPECIALLY COMPARED TO RECENT MILD WEATHER.
BEYOND THIS PERIOD IT STILL LOOKS LIKE A MIDWEEK SYSTEM WILL TAKE A
SIMILAR PATH TO ITS PREDECESSOR AND USHER IN MUCH COLDER AIR FOR THE
END OF THE WEEK INTO THE WEEKEND. CONTINUE WITH A LOW CHANCE OF
SHOWERS AHEAD OF ITS COLD FRONT...WHICH NOW WILL INCLUDE THE TUESDAY
NIGHT PERIOD AS WELL. THE BROAD CYCLONIC FLOW AROUND THIS LOOKS TO
SUPPORT COLD ADVECTION AND CLOUDS INTO WEDNESDAY NIGHT AND COULD SEE
A LITTLE BIT OF PATCHY LIGHT SNOW IN NORTHERN AREAS...BUT WITH
FORCING DWINDLING THIS CERTAINLY LOOKS TO BE LIGHT IF IT
MATERIALIZES. FOR TEMPERATURES LATE IN THE WEEK...850MB TEMPERATURES
OF -14C TO -16C LOOK TO SUPPORT AN AIR MASS OF HIGHS STAYING AROUND
OR JUST SHY OF 30 ESPECIALLY BY FRIDAY AND SATURDAY. NIGHTTIME
TEMPERATURES DONT LOOK TO FALL TOO FAR GIVEN THE CONTINUED WIND
FLOW...HOWEVER THAT WIND WILL AGAIN MAKE IT FEEL MUCH COLDER FROM
DECEMBER THUS FAR.
MTF
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 22Z...
* LOW MVFR/IFR CIGS/VIS DROPPING TO LIFR...POSSIBLY VLIFR...BY
EARLY THIS EVENING...THEN IMPROVING OVERNIGHT.
* CHANCE OF SHRA LATE EVENING/OVERNIGHT.
* RAIN DEVELOPING SUNDAY MORNING...CONTINUING THRU SUNDAY NIGHT.
* EASTERLY WINDS UNDER 10KT SHIFTING SOUTHERLY TONIGHT.
* STRONG/GUSTY SOUTH/SOUTHEASTERLY WINDS SUNDAY AFTERNOON INTO
SUNDAY EVENING. CMS
//DISCUSSION...UPDATED 22Z...
WINDS HAVE SHIFTING EASTERLY ACROSS MUCH OF NORTHEAST IL AND FAR
NORTHWEST INDIANA WITH A SLOW DOWNWARD TREND FOR BOTH CIGS AND
VIS. SHORT TERM HRRR INDICATES FOG WITH VIS UNDER 1SM WILL SPREAD
BACK ACROSS ORD/MDW OVER THE NEXT FEW HOURS AND MAINTAINED CURRENT
FORECAST OF TEMPO INTO PREVAILING. HOW LONG THESE LOWER CONDITIONS
PERSIST IS SOMEWHAT UNCERTAIN AS SOUTHERLY WINDS PUSH THE WARM
FRONT BACK NORTH OF MDW LATER THIS EVENING AND OVERNIGHT AT ORD.
THUS THE DURATION COULD BE SHORTER THAN CURRENTLY INDICATED. CMS
PREV DISCUSSION...UPDATED 18Z...
VSBY/CIGS CONTINUE TO SLOWLY IMPROVE LATE THIS MORNING AS WARM
FRONTAL BOUNDARY GRADUALLY SHIFTS NORTHWARD. EXPECT MAINLY IFR
CIGS THROUGH MID AFTERNOON WITH VSBY LOOKING TO PEAK AT MVFR
LEVELS WITH SOME IFR LIKELY LINGERING. A LAKE BOUNDARY WILL PUSH
INLAND LATE THIS AFTERNOON TURNING WINDS NORTHEAST AT ORD/MDW/GYY
WITH DPA/RFD ALSO SEEING A SHIFT TO EAST OR NORTHEAST AS THE WARM
FRONT RE-POSITIONS SOUTHWARD THIS EVENING. THE MAIN CONCERN IS
DENSE FOG MOVING INLAND AS COLD LAKE AIR ENCOUNTERS DEWPOINTS IN
THE MID AND UPPER 50S. EXPECT VSBY TO FAIRLY QUICKLY DROP BELOW
1SM BEHIND THE WIND SHIFT AND ULTIMATELY END UP IN THE 1/4 TO 1/2
SM RANGE BY EARLY EVENING WITH LOWER VSBY POSSIBLE AT TIMES.
TIMING ADJUSTMENTS MAY STILL BE NEEDED WITH LATER TAF UPDATES.
THE FRONT WILL LIFT NORTHWARD AGAIN LATE TONIGHT TURNING WIND
SOUTHERLY AND BRINGING IMPROVEMENT TO VSBY. CIGS MAY REMAIN IFR AS
WELL. SHOWER CHANCES INCREASE WEST AND CANNOT RULE OUT SOME
THUNDER TOO. IFR CIGS MAY CONTINUE THROUGH SUNDAY MORNING WITH
HIGHER SHOWER/THUNDER COVERAGE EXPANDING EASTWARD WITH TIME. SOUTH
WINDS WILL INCREASE MARKEDLY BY AFTERNOON WITH SUSTAINED SPEEDS OF
15-20 KT AND GUSTS OF 25-30 KT POSSIBLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 22Z...
* MEDIUM CONFIDENCE FOR CIGS/VIS THIS EVENING...LOW FOR END
TIMING/IMPROVEMENT LATE THIS EVENING/OVERNIGHT.
* MEDIUM FOR SHRA LATER THIS EVENING/OVERNIGHT...LOW FOR TIMING/
DURATION.
* HIGH FOR RAIN DEVELOPING SUNDAY MORNING AND CONTINUING INTO
SUNDAY NIGHT.
* MEDIUM FOR WINDS THRU THE PERIOD. CMS
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
316 PM CST
A FRONTAL BOUNDARY REMAINS DRAPED ACROSS THE FAR SOUTHERN PART OF
THE LAKE LATE SATURDAY AFTERNOON. ALONG AND TO THE SOUTH OF THIS
BOUNDARY IS A HIGHLY ANOMALOUS MOIST AIRMASS FOR THIS TIME OF YEAR.
THAT HAS ALREADY MATERIALIZED IN DENSE FOG ACROSS THE FAR SOUTHERN
PART OF THE LAKE AND ENVISION THAT ONLY THICKENING TONIGHT. ITS
UNCERTAIN IF THAT WILL CREEP NORTHWARD MUCH TONIGHT WITH THE
BOUNDARY NOT EXPECTED TO MOVE MUCH UNTIL LATE IN THE NIGHT. DURING
THE DAY SUNDAY MUCH OF THE LAKE SHOULD SEE FOG...PROBABLY DENSE IN
AREAS. RAIN SHOWER ACTIVITY SHOULD MAINLY HOLD UNTIL AFTER DARK
SUNDAY NIGHT WHICH COMBINED WITH EVEN STRONGER SOUTHERLY WINDS
SHOULD EASE THE THREAT OF DENSE FOG.
INCREASING SOUTHEAST WINDS ON SUNDAY WILL REACH SMALL CRAFT ADVISORY
CRITERIA ALONG THE ILLINOIS AND INDIANA NEARSHORE AREAS. THESE
SHOULD INCREASE EVEN MORE SUNDAY NIGHT AND SPREAD NORTHWARD AS DEEP
LOW PRESSURE MOVES NORTH ACROSS IOWA. A SHARP INVERSION OVER THE
LAKE WILL LIMIT THE MAXIMUM GUST POTENTIAL...BUT A HIGH ENOUGH
SUSTAINED SPEED COULD STILL RESULT IN SOME GUSTS NEARING GALE FORCE.
BEHIND THE COLD FRONT ON MONDAY MORNING INTO THE
AFTERNOON...SOUTHWEST WINDS WILL BE AROUND 30 KT WITH POSSIBLY SOME
SPOTTY GUSTS OF GALE FORCE...AGAIN MAINLY ACROSS THE SOUTH.
MTF
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ014 UNTIL 3
AM SUNDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 9 AM SUNDAY.
&&
$$
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AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
304 PM CST SAT DEC 12 2015
.SHORT TERM...(Tonight)
ISSUED AT 304 PM CST SAT DEC 12 2015
Record highs were set in Springfield, Peoria and Lincoln this
afternoon, with Springfield at least reaching 69F and Peoria and
Lincoln reaching at least 67F so far today. A few breaks in the low
clouds along with south winds 8-16 mph and gusts 20-25 mph and a
mild start to the day in the low to mid 50s help set these records.
Temps reached 70F as far north as a Jacksonville to Effingham to
Terre Haute line today while areas north of Peoria reached low to
mid 60s. Record warm lows will likely be set today (Dec 12) as well
and likely again tomorrow (Dec 13). Lows tonight projected to be
close to dewpoints in the upper 50s and lower 60s. These readings
are well above normal lows in the lower 20s central IL and mid
to upper 20s southeast IL.
999 mb surface low pressure over northeast NM and north Texas has a
warm front extending ne into se KS, nw MO and northern IL just south
of I-80 where fog lingers near this boundary. Fog lifted over
northern CWA by midday though broken to overcast low clouds lingered
over central and southeast IL though ceilings lifting to MVFR 1-3k
ft and even VFR above 3k ft. HRRR keeps brunt of fog, including
dense fog, north of central IL tonight as warm front lifts slowly
north toward the WI/IL border by early Sunday morning, while surface
low deepens to 994 mb over the eastern KS/OK border by 15Z/9 am
Sunday. Will have 20-40% chance of showers arriving over western
half of CWA during this evening, then pops increase to likely to
categorical during overnight over IL river valley with isolated
thunderstorms possible west of the IL river by overnight per SPC
day1 outlook. Eastern IL east of I-57 will likely stay dry much of
tonight aside of isolate light rain showers later near I-57.
Rainfall amounts tonight will range from a tenth to quarter inch
over IL river valley and less than a tenth inch along and east of I-
55, with little or no rain tonight from I-57 east. SSE winds 5-15
mph this evening to increase to 10-20 mph during overnight as low
pressure deepens and approaches the Ozarks.
&&
.LONG TERM...(Sunday through Saturday)
ISSUED AT 304 PM CST SAT DEC 12 2015
Models in somewhat better agreement with timing of the pcpn coming
weather system, but still seeing differences where operational ECMWF
is more aggressive and operational NAM is slowest. That puts the GFS
and the Canadian in the middle. Models do look very similar with the
timing of the sfc and upper level fields and features, so have some
confidence in this forecast. Pcpn should be ongoing in the west at
the beginning of tomorrow morning and then continue to move eastward
across the CWA through the day. Southeast parts of the CWA will be
the last to see pcpn and probably will not until sometime in the
late afternoon. Rain should also be moderate to heavy at times and
this will continue into Sun night. Overall QPF amounts with this
system have decreased over the last several days, but looks like now
that over an inch to just over 1.5 inches will be possible west of I-
55, with highest amounts northwest of the Illinois river. Amounts
less than an inch will be likely east of I-55 toward the Indiana
border. Once the low pressure area and upper level system pulls
north into the Great Lakes region, pcpn should come to an end across
the area. Wrap around moisture will keep clouds and lighter pcpn
over the CWA on Monday. But after this, dry weather and decreasing
clouds are expected for Mon night and Tue.
Temps will remain warm Sunday and possible that record highs could
be set again, like today. Temps will decrease for Mon and Tue, but
will still remain above normal for middle Dec. Overnight lows will
also be above normal but be on the decrease from Sun night into Mon
night.
After a brief break in the pcpn with flow remaining out of the
southwest, another weather system will track across the state Tue
night and Wed. This system should be lacking in good moisture with
the best dynamics being northwest of the CWA. This system is
forecast to move quickly through the region, so am sticking with
just slight chance of pcpn over most of the area and chance pcpn in
the central parts for Tue night, and then chance pcpn in the east
and southeast for Wed. Once this weather system moves northeast of
the area, the flow will be changing. Models forecast a mid level
trough to push into the area with cooler high pressure on the sfc.
This will lead to dry weather and cooler temps than what we have
experienced the last week.
Temps will actually drop to below normal for middle Dec for Thur
through Sat. MEX guidance supports cooler, below normal temps, but
believe guidance is too low.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday afternoon)
ISSUED AT 1159 AM CST SAT DEC 12 2015
Dense fog has lifted along I-74 late this morning and most vsbys
are in the 4-8 mile range at midday, except 2 miles still at BMI.
Vsbys should lift to vfr in next hour or two and some patchy fog
could return again tonight though not as widespread as this
morning due to strong sse winds expected next 24 hours. Ceilings
are 300-500 ft at BMI and PIA while up to 1k ft at DEC and CMI
while after 3k ft (VFR) at SPI. Expect ceilings to gradually lift
over central IL airports to MVFR and even VFR range by mid
afternoon. But IFR to low end MVFR ceilings and MVFR vsbys 3-5
miles to return during tonight into Sunday morning. Most areas
will stay dry tonight with chances of rain showers increasing over
western airports later tonight into Sunday morning while eastern
IL at DEC and CMI likely remains dry through 18Z/Sunday with just
isolated showers possible Sunday morning. SSW winds 10-15 kts with
gusts up to 20 kts this afternoon to veer back to the SSE and
increase to 14-18 kts with gusts 20-24 kts later tonight into
Sunday morning.
&&
.CLIMATE...
ISSUED AT 300 AM CST FRI DEC 10 2015
Record highs for the weekend:
Location Today Sunday
DEC 12 DEC 13
---------- --------- ---------
Bloomington 65 (1896) 63 (1975)
Champaign 62 (1991) 64 (1975)
Charleston 67 (1949) 64 (1991)
Decatur 65 (1929) 66 (1975)
Effingham 67 (1929) 65 (1991)
Lincoln 64 (1929) 64 (1975)
Peoria 62 (1991) 63 (1975)
Springfield 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Auten
AVIATION...07
CLIMATE...Auten
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
221 PM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* MVFR CONDITIONS DROPPING BACK TO IFR LATE TODAY AND LIFR
TONIGHT...RIGHT NOW SLIGHTLY MORE FAVORED DROPPING TO LIFR EARLY
THIS EVENING.
* WINDS SHIFT NORTHEAST AT BOTH AIRPORTS LATE THIS AFTERNOON BUT
GENERALLY REMAIN LIGHT. VISIBILITY OF 3/4SM OR LESS EXPECTED
WITH TIMING OF SHIFT STILL THE MAIN QUESTION.
* VISIBILITY IMPROVES AS WINDS TURN SOUTHERLY OVERNIGHT OR EARLY
MONDAY MORNING.
* GUSTY SOUTHWEST WINDS AND SHOWERS EXPECTED SUNDAY WITH IFR CIGS
POTENTIALLY CONTINUING.
MDB/MTF
//DISCUSSION...UPDATED 20Z...
THE FRONTAL BOUNDARY AS OF 20Z REMAINS DRAPED FROM WEST-TO-EAST
JUST NORTH OF I-88...VERY CLOSE TO ORD...AND THROUGH DOWNTOWN
CHICAGO. ALONG AND NORTH OF THIS WILL BE MOST FAVORED FOR DENSE
FOG BY EARLY EVENING...HOWEVER THE MARINE INDUCED FOG REMAINS A
WILDCARD. IF THAT CAN SPREAD INLAND THAT WILL IMPACT MDW AND ORD
FAIRLY QUICKLY TOWARD SUNSET. WEBCAMS CONTINUE TO INDICATE LIFR
CIGS AND IFR /AT TIMES LIFR/ VISIBILITY NEAR THE LAKE FRONT. WILL
CONTINUE TO MONITOR BUT AT THIS TIME HAVE INCHED BACK THE START OF
THE LOWEST CIGS/VISBYS AT ORD/MDW.
MTF
PREV DISCUSSION...UPDATED 18Z...
VSBY/CIGS CONTINUE TO SLOWLY IMPROVE LATE THIS MORNING AS WARM
FRONTAL BOUNDARY GRADUALLY SHIFTS NORTHWARD. EXPECT MAINLY IFR
CIGS THROUGH MID AFTERNOON WITH VSBY LOOKING TO PEAK AT MVFR
LEVELS WITH SOME IFR LIKELY LINGERING. A LAKE BOUNDARY WILL PUSH
INLAND LATE THIS AFTERNOON TURNING WINDS NORTHEAST AT ORD/MDW/GYY
WITH DPA/RFD ALSO SEEING A SHIFT TO EAST OR NORTHEAST AS THE WARM
FRONT RE-POSITIONS SOUTHWARD THIS EVENING. THE MAIN CONCERN IS
DENSE FOG MOVING INLAND AS COLD LAKE AIR ENCOUNTERS DEWPOINTS IN
THE MID AND UPPER 50S. EXPECT VSBY TO FAIRLY QUICKLY DROP BELOW
1SM BEHIND THE WIND SHIFT AND ULTIMATELY END UP IN THE 1/4 TO 1/2
SM RANGE BY EARLY EVENING WITH LOWER VSBY POSSIBLE AT TIMES.
TIMING ADJUSTMENTS MAY STILL BE NEEDED WITH LATER TAF UPDATES.
THE FRONT WILL LIFT NORTHWARD AGAIN LATE TONIGHT TURNING WIND
SOUTHERLY AND BRINGING IMPROVEMENT TO VSBY. CIGS MAY REMAIN IFR AS
WELL. SHOWER CHANCES INCREASE WEST AND CANNOT RULE OUT SOME
THUNDER TOO. IFR CIGS MAY CONTINUE THROUGH SUNDAY MORNING WITH
HIGHER SHOWER/THUNDER COVERAGE EXPANDING EASTWARD WITH TIME. SOUTH
WINDS WILL INCREASE MARKEDLY BY AFTERNOON WITH SUSTAINED SPEEDS OF
15-20 KT AND GUSTS OF 25-30 KT POSSIBLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN CIG/VSBY TRENDS TIL 23Z. LOW CONFIDENCE FROM
23Z THROUGH 02Z. MEDIUM CONFIDENCE AFTER THAT POINT.
* MEDIUM CONFIDENCE IN VISIBILITY FALLING TO 3/4SM OR LESS LATE
EARLY-MIDDLE THIS EVENING. LOW IN SPECIFIC TIMING.
* MEDIUM-HIGH CONFIDENCE IN VISIBILITY IMPROVING LATE TONIGHT BUT
LOW-MEDIUM CONFIDENCE IN TIMING AND MAGNITUDE. MEDIUM
CONFIDENCE IN WIND GUSTS SUNDAY. LOW-MEDIUM CONFIDENCE IN CIG
HEIGHTS SUNDAY.
MDB/MTF
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005 UNTIL 6 PM SATURDAY.
DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL MIDNIGHT SUNDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 9 AM SUNDAY.
&&
$$
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1145 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* IFR CIGS LIKELY PREVAILING THROUGH MID AFTERNOON WITH SOME MVFR
BREAKS POSSIBLE. IFR/MVFR VSBY THROUGH MID AFTERNOON.
* WINDS SHIFT NORTHEAST LATE THIS AFTERNOON BRINGING DENSE FOG
INLAND. VSBY OF 1/2SM OR LESS EXPECTED WITH TIMING STILL THE
MAIN QUESTION.
* VSBY IMPROVES AS WINDS TURN SOUTHERLY OVERNIGHT. GUSTY SOUTHWEST
WINDS AND SHOWERS EXPECTED SUNDAY WITH IFR CIGS POTENTIALLY
CONTINUING.
MDB
//DISCUSSION...UPDATED 18Z...
VSBY/CIGS CONTINUE TO SLOWLY IMPROVE LATE THIS MORNING AS WARM
FRONTAL BOUNDARY GRADUALLY SHIFTS NORTHWARD. EXPECT MAINLY IFR
CIGS THROUGH MID AFTERNOON WITH VSBY LOOKING TO PEAK AT MVFR
LEVELS WITH SOME IFR LIKELY LINGERING. A LAKE BOUNDARY WILL PUSH
INLAND LATE THIS AFTERNOON TURNING WINDS NORTHEAST AT ORD/MDW/GYY
WITH DPA/RFD ALSO SEEING A SHIFT TO EAST OR NORTHEAST AS THE WARM
FRONT RE-POSITIONS SOUTHWARD THIS EVENING. THE MAIN CONCERN IS
DENSE FOG MOVING INLAND AS COLD LAKE AIR ENCOUNTERS DEWPOINTS IN
THE MID AND UPPER 50S. EXPECT VSBY TO FAIRLY QUICKLY DROP BELOW
1SM BEHIND THE WIND SHIFT AND ULTIMATELY END UP IN THE 1/4 TO 1/2
SM RANGE BY EARLY EVENING WITH LOWER VSBY POSSIBLE AT TIMES.
TIMING ADJUSTMENTS MAY STILL BE NEEDED WITH LATER TAF UPDATES.
THE FRONT WILL LIFT NORTHWARD AGAIN LATE TONIGHT TURNING WIND
SOUTHERLY AND BRINGING IMPROVEMENT TO VSBY. CIGS MAY REMAIN IFR AS
WELL. SHOWER CHANCES INCREASE WEST AND CANNOT RULE OUT SOME
THUNDER TOO. IFR CIGS MAY CONTINUE THROUGH SUNDAY MORNING WITH
HIGHER SHOWER/THUNDER COVERAGE EXPANDING EASTWARD WITH TIME. SOUTH
WINDS WILL INCREASE MARKEDLY BY AFTERNOON WITH SUSTAINED SPEEDS OF
15-20 KT AND GUSTS OF 25-30 KT POSSIBLE.
MDB
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN CIG/VSBY TRENDS TIL 22Z. LOW CONFIDENCE IN
ANY MVFR CIG BREAKS OCCURRING. MEDIUM-HIGH CONFIDENCE IN VSBY
BEING MVFR OR LESS TIL 22Z.
* HIGH CONFIDENCE IN TIMING OF WINDS SHIFTING NORTHEAST LATE THIS
AFTERNOON.
* HIGH CONFIDENCE IN VSBY FALLING TO 1/2SM OR LESS LATE THIS
AFTERNOON/EARLY THIS EVENING. MEDIUM-HIGH CONFIDENCE VSBY
REDUCTIONS BEGINNING IN THE 22-00Z TIME FRAME BUT MEDIUM
CONFIDENCE IN HOW MUCH SUB 1SM VSBY OCCURS DURING THIS TIME.
HIGHER CONFIDENCE IN LOWEST VSBY 00Z AND AFTER.
* MEDIUM-HIGH CONFIDENCE IN VSBY IMPROVING LATE TONIGHT BUT LOW-
MEDIUM CONFIDENCE IN TIMING AND MAGNITUDE. MEDIUM CONFIDENCE IN
WIND GUSTS SUNDAY. LOW-MEDIUM CONFIDENCE IN CIG HEIGHTS SUNDAY.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON
SATURDAY.
DENSE FOG ADVISORY...ILZ006-ILZ014 UNTIL MIDNIGHT SUNDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 9 AM SUNDAY.
&&
$$
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
958 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SMALL FLUCTUATIONS IN LIFR/IFR VSBY THROUGH LATE MORNING WITH
GRADUAL IMPROVEMENT MIDDAY.
* IFR CIGS LIKELY THROUGH THE AFTERNOON THOUGH SHORT PERIOD OF
MVFR CIGS POSSIBLE AT MDW.
* VERY LOW CIGS AND DENSE FOG LIKELY TO ROLL IN OFF LAKE LATE THIS
AFTERNOON OR EARLY THIS EVENING. CONCERNED THAT 1/4-1/2SM VSBY
MAY ARRIVE IN THE 22-00Z TIME FRAME VS. AFTER 00Z CURRENTLY
FORECAST.
MDB
//DISCUSSION...UPDATED 16Z...
LITTLE CHANGE IN CONDITIONS OVER THE LAST FEW HOURS SUPPORTING THE
IDEA THAT IMPROVEMENT IN CIG/VSBY WILL BE SLOW INTO THE AFTERNOON.
NEAR TERM GUIDANCE STILL PUSHES THE WARM FRONTAL BOUNDARY
NORTHWARD INTO THE EARLY AFTERNOON. OBS ACROSS NORTH-CENTRAL IL DO
SHOW THIS OCCURRING MARKED BY AN INCREASE IN TEMPS/DEWPOINTS. THE
PROBLEM IS THAT AREAS TO THE SOUTH BEHIND THE FRONT ARE STILL
STILL SEEING VERY LOW CIGS/VSBY. HAVE SLOWED THE RATE OF
IMPROVEMENT OF CIGS/VSBY IN THE TAFS AND ALSO LOWERED CONDITIONS
THROUGH THE AFTERNOON WHEN THE FRONT SHOULD BE TO THE NORTH.
THE INLAND MOVEMENT OF LAKE INFLUENCED AIR IS STILL A CONCERN AS
WELL. TIMING OF THE SHIFT TO NORTHEAST WINDS AT EACH TERMINAL
STILL LOOKS REASONABLE BUT AM CONCERNED THAT VSBY MAY FALL
DRASTICALLY SOONER THAN IN THE CURRENT TAFS. WOULD NOT BE
SURPRISED TO SEE VSBY IN THE 1/4-1/2SM VSBY WITHIN AN HOUR OR SO
OF THE WIND SHIFT AND POTENTIALLY FALLING INTO THE 1/8-1/4SM RANGE
THIS EVENING. WILL CONTINUE TO MONITOR THIS AND REFINE WITH THE
UPCOMING TAFS.
MDB
FROM 12Z...
WARM FRONT CURRENTLY SITTING BETWEEN ORD AND MDW WILL DRIFT SLOWLY
NORTH HEADING INTO THE EARLY AFTERNOON. PRIOR TO THE FRONT MOVING
THROUGH ORD EXPECT LIFR CIGS AND AT LEAST IFR VSBY WITH A CHANCE
FOR A PERIOD OF LIFR VSBY THIS MORNING BEFORE SOME IMPROVEMENT
TAKES PLACE MIDDAY INTO MID AFTERNOON AS WARM FRONT ATTEMPTS TO
MOVE THROUGH ORD. MDW SHOULD REMAIN SOUTH OF THE FRONT AND SHOULD
SEE IMPROVEMENT TO MVFR CONDITIONS BY MID-LATE MORNING WHICH
SHOULD PERSIST THROUGH MUCH OF THE AFTERNOON.
WEAK FRONT SHOULD ALLOW A LAKE BREEZE FRONT TO DEVELOP AND SURGE
INLAND LATE THIS AFTERNOON AND EFFECTIVELY PUSH THE WARM FRONT
BACK SOUTH OF THE TERMINALS BETWEEN 22Z-00Z. AS THE LAKE CHILLED
AIR ENCOUNTERS THE INCREDIBLY MOIST AIR MASS LOOK FOR DENSE FOG TO
FORM INITIALLY ALONG THE LAKE FRONT AND LIKELY SPREADING TO
ORD/MDW EARLY THIS EVENING. TIMING OF WHEN DENSE FOG ARRIVES IS
HARD TO PIN DOWN...BUT SYNOPTICALLY THE SET UP STRONGLY FAVORS
DENSE FOG. FOR NOW JUST TOOK ORD AND MDW DOWN TO 1/2SM PREVAILING
DUE TO INHERENT UNCERTAINTIES WHEN FORECASTING FOG...HOWEVER
WOULDNT BE AT ALL SURPRISED TO SEE MANY HOURS OF 1/8SM TO 1/4SM
TONIGHT PRIOR TO WARM FRONT MOVING BACK NORTH THROUGH THE
TERMINALS AFTER MIDNIGHT. CIGS/VSBY SHOULD IMPROVE RAPIDLY WHEN
THE WARM FRONT LIFTS BACK NORTH ACROSS THE TERMINALS LATE TONIGHT.
LIGHT WINDS IN VICINITY OF FRONT THIS MORNING SHOULD TEND TO
BECOME LIGHT SOUTHERLY SOUTH OF THE WARM FRONT LATE THIS MORNING
INTO THIS AFTERNOON...FOLLOWED BY SHIFT TO NORTHEAST 5-10KT BEHIND
THE LAKE ENHANCED FRONT LATE THIS AFTERNOON WITH LIGHT NE WINDS
MUCH OF THE NIGHT BEFORE VEERING EAST PRIOR TO A SHIFT TO SOUTH
AS WARM FRONT LIFTS BACK NORTH LATE TONIGHT.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH CONFIDENCE IN OVERALL CIGS/VSBY TRENDS WITH MEDIUM
CONFIDENCE THAT IFR CIGS AND MVFR VSBY PREVAILS FOR A TIME THIS
AFTERNOON.
* MEDIUM-HIGH CONFIDENCE IN DENSE FOG BY THIS EVENING...LOW-MEDIUM
CONFIDENCE ON TIMING OF ARRIVAL AND DEPARTURE OF DENSE FOG. LOW
BUT INCREASING CONFIDENCE THAT ARRIVAL OF 1/2SM OR LOWER VSBY
WILL BE FASTER THAN INDICATED IN 16Z TAF.
* HIGH CONFIDENCE IN WINDS STAYING PRIMARILY BELOW 10KT...LOWER
CONFIDENCE IN PRECISE DIRECTIONS AS FRONT WAVERS AROUND REGION.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON
SATURDAY.
IN...NONE.
LM...DENSE FOG ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743-LMZ744-LMZ745-
LMZ777-LMZ779 UNTIL 9 AM SUNDAY.
&&
$$
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
824 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 14Z...
* SMALL FLUCTUATIONS IN LIFR/IFR VSBY THROUGH LATE MORNING WITH
GRADUAL IMPROVEMENT MIDDAY.
* PERIOD OF MVFR CONDITIONS POSSIBLE...ESPECIALLY AT MDW MIDDAY INTO
THE AFTERNOON.
* VERY LOW CIGS AND DENSE FOG LIKELY TO ROLL IN OFF LAKE LATE
THIS AFTERNOON OR EARLY THIS EVENING.
MDB
//DISCUSSION...UPDATED 14Z...
VSBY HAS CREPT DOWNWARD OVER THE LAST HOUR OR SO WITH SOME SMALL
FLUCTUATIONS NOTED IN SOME OBS. EXPECT THAT OCCASIONAL 1/4SM VSBY
WILL BE LIKELY RFD/DPA WITH MDW POTENTIALLY SEEING 1/2SM BRIEFLY
BEFORE 16Z BUT PROBABLY HOLDING IN THE 3/4-1SM RANGE. ORD MAY ALSO
SEE BRIEF 1/2-3/4SM BUT PROBABLY HOLD STEADIER IN THE 3/4-1SM
RANGE. GYY SHOULD BE IFR BUT LOOKS TO HAVE A LOWER CHANCE OF
SEEING SUB 1SM VSBY. TIMING OF IMPROVEMENT REMAINS TRICKY AND
HAVE SLOWED THE IMPROVEMENT GIVEN THE VERY MOIST AIRMASS AND VERY
LOW CONDITIONS UPSTREAM TO THE SOUTH. MVFR CIGS MAY BE TOUGH TO
COME BY FOR ANY LENGTH OF TIME THIS AFTERNOON. STILL EXPECT THE
FLOW TO TURN OFF THE LAKE LATER THIS AFTERNOON SUPPORTING A RETURN
TO VERY LOW VSBY AT ORD/MDW/GYY WITH A SLOWER DECREASE FURTHER
INLAND THIS EVENING AS THE WARM FRONT SETS UP TO THE SOUTH AGAIN.
CURRENT TIMING IN TAF MAY NEED TWEAKING.
MDB
FROM 12Z...
WARM FRONT CURRENTLY SITTING BETWEEN ORD AND MDW WILL DRIFT SLOWLY
NORTH HEADING INTO THE EARLY AFTERNOON. PRIOR TO THE FRONT MOVING
THROUGH ORD EXPECT LIFR CIGS AND AT LEAST IFR VSBY WITH A CHANCE
FOR A PERIOD OF LIFR VSBY THIS MORNING BEFORE SOME IMPROVEMENT
TAKES PLACE MIDDAY INTO MID AFTERNOON AS WARM FRONT ATTEMPTS TO
MOVE THROUGH ORD. MDW SHOULD REMAIN SOUTH OF THE FRONT AND SHOULD
SEE IMPROVEMENT TO MVFR CONDITIONS BY MID-LATE MORNING WHICH
SHOULD PERSIST THROUGH MUCH OF THE AFTERNOON.
WEAK FRONT SHOULD ALLOW A LAKE BREEZE FRONT TO DEVELOP AND SURGE
INLAND LATE THIS AFTERNOON AND EFFECTIVELY PUSH THE WARM FRONT
BACK SOUTH OF THE TERMINALS BETWEEN 22Z-00Z. AS THE LAKE CHILLED
AIR ENCOUNTERS THE INCREDIBLY MOIST AIR MASS LOOK FOR DENSE FOG TO
FORM INITIALLY ALONG THE LAKE FRONT AND LIKELY SPREADING TO
ORD/MDW EARLY THIS EVENING. TIMING OF WHEN DENSE FOG ARRIVES IS
HARD TO PIN DOWN...BUT SYNOPTICALLY THE SET UP STRONGLY FAVORS
DENSE FOG. FOR NOW JUST TOOK ORD AND MDW DOWN TO 1/2SM PREVAILING
DUE TO INHERENT UNCERTAINTIES WHEN FORECASTING FOG...HOWEVER
WOULDNT BE AT ALL SURPRISED TO SEE MANY HOURS OF 1/8SM TO 1/4SM
TONIGHT PRIOR TO WARM FRONT MOVING BACK NORTH THROUGH THE
TERMINALS AFTER MIDNIGHT. CIGS/VSBY SHOULD IMPROVE RAPIDLY WHEN
THE WARM FRONT LIFTS BACK NORTH ACROSS THE TERMINALS LATE TONIGHT.
LIGHT WINDS IN VICINITY OF FRONT THIS MORNING SHOULD TEND TO
BECOME LIGHT SOUTHERLY SOUTH OF THE WARM FRONT LATE THIS MORNING
INTO THIS AFTERNOON...FOLLOWED BY SHIFT TO NORTHEAST 5-10KT BEHIND
THE LAKE ENHANCED FRONT LATE THIS AFTERNOON WITH LIGHT NE WINDS
MUCH OF THE NIGHT BEFORE VEERING EAST PRIOR TO A SHIFT TO SOUTH
AS WARM FRONT LIFTS BACK NORTH LATE TONIGHT.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 14Z...
* MEDIUM-HIGH CONFIDENCE IN OVERALL CIGS/VSBY TRENDS.
* MEDIUM-HIGH CONFIDENCE IN DENSE FOG BY THIS EVENING...LOW-MEDIUM
CONFIDENCE ON TIMING OF ARRIVAL AND DEPARTURE OF DENSE FOG.
* HIGH CONFIDENCE IN WINDS STAYING PRIMARILY BELOW 10KT...LOWER
CONFIDENCE IN PRECISE DIRECTIONS AS FRONT WAVERS AROUND REGION.
MDB
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012-ILZ019-ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON
SATURDAY.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
548 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* IFR/LIFR CIGS AND SOME FOG LIKELY THIS MORNING
* PERIOD OF MVFR CONDITIONS LIKELY...ESPECIALLY AT MDW LATE
MORNING INTO THE AFTERNOON
* VERY LOW CIGS AND DENSE FOG LIKELY TO ROLL IN OFF LAKE LATE
THIS AFTERNOON OR EARLY THIS EVENING
IZZI
//DISCUSSION...UPDATED 12Z...
WARM FRONT CURRENTLY SITTING BETWEEN ORD AND MDW WILL DRIFT SLOWLY
NORTH HEADING INTO THE EARLY AFTERNOON. PRIOR TO THE FRONT MOVING
THROUGH ORD EXPECT LIFR CIGS AND AT LEAST IFR VSBY WITH A CHANCE
FOR A PERIOD OF LIFR VSBY THIS MORNING BEFORE SOME IMPROVEMENT
TAKES PLACE MIDDAY INTO MID AFTERNOON AS WARM FRONT ATTEMPTS TO
MOVE THROUGH ORD. MDW SHOULD REMAIN SOUTH OF THE FRONT AND SHOULD
SEE IMPROVEMENT TO MVFR CONDITIONS BY MID-LATE MORNING WHICH
SHOULD PERSIST THROUGH MUCH OF THE AFTERNOON.
WEAK FRONT SHOULD ALLOW A LAKE BREEZE FRONT TO DEVELOP AND SURGE
INLAND LATE THIS AFTERNOON AND EFFECTIVELY PUSH THE WARM FRONT
BACK SOUTH OF THE TERMINALS BETWEEN 22Z-00Z. AS THE LAKE CHILLED
AIR ENCOUNTERS THE INCREDIBLY MOIST AIR MASS LOOK FOR DENSE FOG TO
FORM INITIALLY ALONG THE LAKE FRONT AND LIKELY SPREADING TO
ORD/MDW EARLY THIS EVENING. TIMING OF WHEN DENSE FOG ARRIVES IS
HARD TO PIN DOWN...BUT SYNOPTICALLY THE SET UP STRONGLY FAVORS
DENSE FOG. FOR NOW JUST TOOK ORD AND MDW DOWN TO 1/2SM PREVAILING
DUE TO INHERENT UNCERTAINTIES WHEN FORECASTING FOG...HOWEVER
WOULDNT BE AT ALL SURPRISED TO SEE MANY HOURS OF 1/8SM TO 1/4SM
TONIGHT PRIOR TO WARM FRONT MOVING BACK NORTH THROUGH THE
TERMINALS AFTER MIDNIGHT. CIGS/VSBY SHOULD IMPROVE RAPIDLY WHEN
THE WARM FRONT LIFTS BACK NORTH ACROSS THE TERMINALS LATE TONIGHT.
LIGHT WINDS IN VICINITY OF FRONT THIS MORNING SHOULD TEND TO
BECOME LIGHT SOUTHERLY SOUTH OF THE WARM FRONT LATE THIS MORNING
INTO THIS AFTERNOON...FOLLOWED BY SHIFT TO NORTHEAST 5-10KT BEHIND
THE LAKE ENHANCED FRONT LATE THIS AFTERNOON WITH LIGHT NE WINDS
MUCH OF THE NIGHT BEFORE VEERING EAST PRIOR TO A SHIFT TO SOUTH
AS WARM FRONT LIFTS BACK NORTH LATE TONIGHT.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* MEDIUM-HIGH CONFIDENCE IN OVERALL CIGS/VSBY TRENDS
* MEDIUM-HIGH CONFIDENCE IN DENSE FOG BY THIS EVENING...LOW-MEDIUM
CONFIDENCE ON TIMING OF ARRIVAL AND DEPARTURE OF DENSE FOG
* HIGH CONFIDENCE IN WINDS STAYING PRIMARILY BELOW 10KT...LOWER
CONFIDENCE IN PRECISE DIRECTIONS AS FRONT WAVERS AROUND REGION
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z MONDAY-12Z SATURDAY...UPDATED 12Z...
SUNDAY NIGHT...PERIODIC SHRA. IFR LIKELY.
MONDAY...PERIODIC SHRA IN THE MORNING. MVFR CIGS.
TUESDAY...VFR.
WEDNESDAY...SMALL CHANCE OF SHRA/MVFR CIGS.
THURSDAY AND FRIDAY...MVFR CIGS A GOOD BET.
IZZI
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...DENSE FOG ADVISORY...ILZ003-ILZ004-ILZ005-ILZ008-ILZ010-ILZ011-
ILZ012 UNTIL NOON SATURDAY.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
331 AM CST SAT DEC 12 2015
.SHORT TERM...
331 AM CST
THROUGH SUNDAY NIGHT...
EXCEEDINGLY TRICKY FORECAST IN THE SHORT TERM...PARTICULARLY WITH
RESPECT TO FOG AND TEMPS.
A SET-UP FAR MORE TYPICAL OF LATE MARCH OR EARLY APRIL WILL PLAY
HAVOC ON TEMP FORECAST AND LIKELY RESULT IN DENSE LAKE FOG
DEVELOPING. WARM FRONT HAS LIFTED NORTH AND LIES JUST NORTH OF I-80
EARLY THIS MORNING. DENSE FOG HAS BEEN PATCHY SO FAR AND CONFINED TO
AREAS MAINLY WEST AND SOUTHWEST OF OUR CWA THUS FAR...HOWEVER SHORT
RANGE GUIDANCE STILL SUGGESTS THAT THE DENSE FOG COULD EXPAND IN
COVERAGE AND IMPACT MAINLY OUR WESTERN AND SOUTHWESTERN COUNTIES
THIS MORNING. WILL TAKE A WAIT AND SEE APPROACH ON THIS GIVEN HOW
LACKLUSTER THIS MORNING`S FOG EVENT HAS BEEN THUS FAR.
WEAK SURFACE LOW OVER IOWA IS PROGGED TO DISSIPATE TODAY WITH
SURFACE CYCLOGENESIS TAKES PLACE OVER THE SOUTHERN HIGH PLAINS.
AS THE LOW WEAKENS...LOOK FOR SURFACE FRONTOLYSIS TO BEGIN WITH
WARMFRONT OVER OUR CWA. AS THE SYNOPTIC FRONT WEAKENS IT WILL OPEN
THE DOOR FOR LAKE MICHIGAN`S CHILLING EFFECTS TO TAKE OVER LATER
THIS AFTERNOON AND EVENING. WEAK AND WEAKENING PRESSURE GRADIENT IN
THE VICINITY OF THE WEAKENING FRONT WILL LIKELY ALLOW A LAKE BREEZE
FRONT TO DEVELOP THIS AFTERNOON DUE IN PART TO THE INCREASINGLY
LARGE THERMAL DIFFERENTIAL BETWEEN CHILLY MARINE AIR MASS OVER THE
LAKE AND UNSEASONABLY WARM AND ALMOST HUMID AIR OVER LAND. AS THE
COOL MARINE AIR ENCOUNTERS 50F+ DEWPOINTS IT APPEARS TO BE A CLASSIC
SET-UP FOR VERY DENSE MARINE FOG TO DEVELOP AND SEEP INLAND THIS
EVENING AS THE CHILLY MARINE AIR ENCOUNTERS NOT MUCH RESISTANCE AND
IT ABLE TO SPREAD PRETTY FAR INLAND. IF IT WEREN`T FOR
UNCERTAINTIES REGARDING TIMING OF FOG STARTING AND ENDING...WOULD
PROBABLY BE ISSUING A DENSE FOG ADVISORY NOW FOR THIS EVENING FOR
PORTIONS OF NE IL. DENSE FOG COULD DEVELOP FARTHER INLAND THIS
EVENING AWAY FROM THE MARINE LAYER...MAINLY NEAR AND TO THE NORTH
OF THE WEAKEN WARM FRONT. CONFIDENCE IN DENSE FOG DEVELOPING HERE
IS LOWER.
MODEL THAT HAS BEEN BEST FITTING THE CONCEPTUAL MODEL OF HOW I
EXPECT THINGS TO EVOLVE TODAY HAS BEEN THE EXPERIMENTAL HRRR AND
HAVE USED A TIME LAGGED ENSEMBLE APPROACH WITH THIS MODEL TO
POPULATE SHORT TERM HOURLY TEMP/DEWPOINT/WIND GRIDS INTO THIS
EVENING. DESPITE CLOUD COVER STILL EXPECT TEMPS TO WARM UP NICELY
TODAY...ESPECIALLY SOUTHERN CWA WHERE THEY ARE SOLIDLY IN THE WARM
SECTOR. WARMING TREND IN TEMPS WILL LIKELY BE ABRUPTLY HALTED NEAR
THE LAKE BY EARLY-MID AFTERNOON WHEN LAKE BREEZE FRONT BEGINS MOVING
INLAND AND KNOCKING TEMPS BACK INTO THE 40S NEAR THE LAKE AND
RESULTING IN FALLING TEMPS EVEN WELL INLAND BY EARLY EVENING. TOUGH
CALL ON HOW QUICKLY TEMPS WILL WARM IN CHICAGO BEFORE LAKE AIR
SPREADS INLAND...BUT EXPERIMENTAL HRRR SUGGESTS ORD WILL PROBABLY
NOT GET MUCH ABOVE MID TO MAYBE UPPER 50S BEFORE TEMPS FALL LATE IN
THE EVENING WITH FOG...PROBABLY DENSE LIKELY TO FOLLOW.
TONIGHT...SOUTHERN PLAINS CYCLONE WILL BEGIN MOVING NORTH AND THE
NOW LAKE RE-ENFORCED WARM FRONT WILL BEGIN TO STRENGTHEN AGAIN AND
STRENGTHENING PRESSURE FALLS SHOULD CAUSE THE FRONT TO BEGIN MOVING
NORTH AGAIN. SHOULD BEHAVE LIKE A TYPICAL MARCH WARM FRONT BECOMING
SOMEWHAT CONTORTED AROUND LAKE MICHIGAN WITH NORTH SHORE AREAS
LIKELY BEING THE LAST AREA IN OUR CWA TO MAKE IT INTO THE WARM
SECTOR. EXPECT FOG TO PRIMARILY BE A PROBLEM AHEAD OF THE WARM FRONT
WITH DRAMATICALLY IMPROVING VISIBILITIES AS THE WARM FRONT LIFTS
NORTHWARD. TEMPS IN THE WARM SECTOR TONIGHT WILL LIKELY HOLD IN THE
UPPER 50S TO LOWER 60S...WITH A RAPID RISE IN TEMPERATURES FROM THE
40S TO NEAR 60 EXPECTED IN THE CHICAGO AREA OVERNIGHT AS THE WARM
FRONT LIFTS NORTH.
PRECIP-WISE...NOT EXPECTED MUCH MEASURABLE PRECIP UNTIL TONIGHT.
COULD BE SOME DRIZZLE WITH THE DENSE MARINE FOG AND HRRR SUGGESTS A
FEW LIGHT SHOWERS LATE THIS AFTERNOON IN VICINITY OF THE WARM FRONT.
TONIGHT...THE MAIN FOCUS FOR SHOWERS AND SOME THUNDERSTORMS LOOKS TO
REMAIN MOSTLY TO THE WEST OF OUR CWA CLOSER TO THE STRONG ISENTROPIC
ASCENT AND NEAR THE NOSE OF THE LOW LEVEL JET. STILL EXPECT SOME OF
THIS SHOWER ACTIVITY TO MAKE IT INTO MAINLY NORTH CENTRAL ILLINOIS
WITH A LESSER THREAT OF SHOWERS OVER THE REMAINDER OF THE CWA.
SUNDAY SHOULD BE WINDY AND UNSEASONABLY WARM WITH A PERIOD OR TWO OF
SHOWERS LIKELY...ESPECIALLY WESTERN AND NORTHERN PORTIONS OF THE
AREA. DEPENDING ON THE COVERAGE OF SHOWERS...WE COULD MAKE A RUN AT
THE RECORD HIGHS FOR THE DAY...THOUGH DECIDED TO KEEP TEMPS SOMEWHAT
CONSERVATIVE IN THE GRIDS FOR NOW WITH MAINLY LOW 60S NORTH AND MID
60S SOUTH. ADDITIONAL SHOWERS ARE EXPECTED SUNDAY NIGHT AS FAIRLY
STRONG COLD FRONT EVENTUALLY MOVES ACROSS THE AREA. MAJORITY OF
SUNDAY NIGHT WILL BE WINDY AND UNSEASONABLY WARM WITH TEMPS CLOSE TO
IF NOT IN THE 60S BEFORE COLD FRONT MOVES THROUGH CLOSER TO DAWN
RESULTING IN LOW TEMPS NOT OCCURRING UNTIL AFTER SUNRISE.
IZZI
&&
.LONG TERM...
331 AM CST
MONDAY THROUGH FRIDAY...
WINDY AND MUCH COOLER WEATHER IS ON TAP FOR MONDAY WITH SHOWERS IN
THE MORNING LIKELY TAPERING OFF AND ENDING BY OR PERHAPS DURING THE
EARLY AFTERNOON. WE SHOULD GET A BRIEF BREAK BETWEEN SYSTEM TUESDAY
WITH DRY CONDITIONS AND CONTINUED ABOVE NORMAL TEMPS...BUT MUCH LESS
SO THAN THIS WEEKEND.
NEXT SYSTEM MOVES THROUGH MIDWEEK...BUT AT THIS POINT LOOKS PRETTY
MOISTURE STARVED AS IT WILL BE FAST ON THE HEELS OF THE WEEKEND
SYSTEM WHICH SHOULD BE PRETTY EFFECTIVE AT SCOURING OUT THE
MOISTURE. IN THE WAKE OF THIS STORM IT LOOKS LIKE WE WILL GET A
TASTE OF MORE TYPICAL DECEMBER TEMPERATURES FOR A FEW DAYS LATER
THIS WEEK INTO THE WEEKEND WITH HIGHS NOT GETTING OUT OF THE 30S. IN
FACT...IF THE ECMWF VERIFIES FRIDAY/SATURDAY MAY NOT EVEN REACH 30F
FOR HIGHS WHICH WILL FEEL VERY COLD AFTER THIS WEEKEND`S NEAR RECORD
WARMTH BUT IN REALITY WILL ONLY BE A FEW DEGREES COLDER THAN NORMAL.
MEDIUM RANGE MODELS SUGGEST THAT THE LONGWAVE TROUGH RESPONSIBLE FOR
THE TASTE OF WINTER WILL BE PROGRESSIVE WITH A MODELS AND CPC BOTH
SUGGESTING A RETURN TO ABOVE AVERAGE TEMPERATURES CHRISTMAS WEEK.
IZZI
&&
.CLIMATE...
NEAR RECORD TEMPERATURES ARE FORECAST FOR THE AREA THROUGH
SUNDAY. HERE ARE THE CURRENT RECORD HIGH TEMPERATURES AND WARMEST
LOW TEMPERATURES ON RECORD FOR CHICAGO AND ROCKFORD.
CHICAGO:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 61 (1877) 48 (1968)
DEC 13 67 (1975) 46 (1920)
---------------------------------
ROCKFORD:
RECORD RECORD
HIGH WARMEST LOW
DEC 12 60 (1991) 43 (1968)
DEC 13 57 (1975) 40 (1920)
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* IFR STRATUS THIS MORNING. SHOULD BE A BRIEF PERIOD OF VFR OR
HIGH END MVFR CIGS EARLY THIS AFTN BEFORE ANOTHER ROUND OF IFR-
LIFR STRATUS.
* MVFR VSBY ALSO MOVES IN EARLY THIS MORNING. AFTER A BRIEF PERIOD
OF VFR CONDITIONS EARLY THIS AFTN...VSBY DROPS BACK TO IFR TO
PERHAPS VLIFR THIS EVENING.
* EAST TO MAYBE NE WINDS THIS AFTN LESS THAN 10 KT.
JEE
//DISCUSSION...UPDATED 06Z...
A LOW IS WEAKENING OVER NORTHERN MISSOURI AND A WARM FRONT LIES
JUST SOUTH OF MDW THROUGH NORTHERN IL. THE WARM FRONT WILL VERY
SLOWLY LIFT NORTH THROUGH THIS MORNING AND EVENTUALLY STALL OUT
SOMEWHERE NEAR THE IL/WI STATE LINE. DO NOT HAVE A LOT OF
CONFIDENCE IN HOW FAR NORTH THE FRONT GETS AS GUIDANCE VARIES
GREATLY.
HAVE MUCH HIGHER CONFIDENCE IN STRATUS HANGING AROUND THROUGH THE
MORNING AND SITES HAVING MVFR VSBY OR BETTER TONIGHT. THE STRATUS
SEEMS TO BE INHIBITING DENSE FOG FROM FORMING WITH THE DENSER FOG
FORMING UNDER CLEAR OR SCT SKIES ACROSS WEST CENTRAL IL AND IOWA.
WINDS SHOULD BACK TO SOUTH THIS MORNING BEHIND THE WARM FRONT.
GUIDANCE SUGGESTS THERE SHOULD BE A VERY BRIEF PERIOD OF VFR
CONDITIONS EARLY THIS AFTERNOON BEFORE WINDS BECOME EAST AGAIN.
EXPECTING COOLER AIR OFF OF THE LAKE TO HIT THE MOIST AIR BEHIND
THE FRONT AND FORM ANOTHER IFR TO LIFR STRATUS LAYER AND DENSE
FOG. WINDS MAY EVEN VEER FARTHER NE THAN CURRENTLY FORECAST...BUT
HAVE HIGH CONFIDENCE IN FOG TONIGHT. SINCE FOG DID NOT PAN OUT
TONIGHT...ONLY WENT DOWN TO 3/4-1/2 SM FOR NOW...BUT THINKING
1/4SM FOG WILL FORM ACROSS THE REGION AND PERSIST INTO EARLY
SUNDAY MORNING IF NOT LATER.
JEE
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* MEDIUM CONFIDENCE IN VSBY TRENDS AND VALUES THROUGH THIS
MORNING.
* HIGH CONFIDENCE IN DENSE FOG TONIGHT...MEDIUM CONFIDENCE IN
TIMING.
* HIGH CONFIDENCE IN STRATUS TRENDS AND VALUES...MEDIUM CONFIDENCE
IN TIMING OF POTENTIAL VFR WINDOW AND HOW LONG IT WILL LAST.
* HIGH CONFIDENCE IN WIND SPEEDS...MEDIUM CONFIDENCE IN HOW FAR
NORTH WINDS WILL GO THIS AFTN.
JEE
//OUTLOOK FOR ORD/MDW FOR 12Z SUNDAY-12Z FRIDAY...UPDATED 00Z...
* SUNDAY...RA. IFR CIGS/VIS. STRONG/GUSTY SOUTH/SOUTHEAST WINDS.
* MONDAY...SHRA/MVFR LIKELY. STRONG/GUSTY WEST/SOUTHWEST WINDS.
* TUESDAY...DRY/VFR. SOUTHERLY WINDS.
* WEDNESDAY...DRY/VFR. GUSTY SOUTHWEST WINDS.
* THURSDAY...DRY/VFR. WESTERLY WINDS.
&&
.MARINE...
301 AM CST
A DENSE FOG ADVISORY WILL LIKELY BE NEEDED FOR THE SOUTHERN HALF OF
THE LAKE TODAY. HOWEVER...I HAVE LOW CONFIDENCE IN WHEN THE DENSE
FOG WILL DEVELOP AND HOW LONG IT WILL PERSIST INTO THIS AFTERNOON OR
EVENING SO I WILL NOT BE ISSUING A DENSE FOG ADVISORY NOW. BOATERS
SHOULD BE PREPARED FOR DENSE FOG AND SEVERELY REDUCED VISIBILITIES.
A WEAKENING LOW IS OVER IOWA AND THE LOW WILL WEAKEN BEFORE ENTERING
ILLINOIS TODAY. A WARM FRONT LIES JUST SOUTH OF THE THIS MORNING AND
WILL SHIFT NORTH BUT REMAIN OVER THE SOUTHERN END OF THE LAKE
THROUGH SUNDAY. DENSE FOG IS EXPECTED TO FORM BEHIND THE FRONT. A
LAKE BREEZE WILL LIKELY FORM THIS AFTERNOON ALONG THE IL SHORE. THE
NEXT LOW FORMS OVER THE SOUTHERN PLAINS EARLY SUNDAY MORNING WITH
WINDS BECOMING SOUTHEAST ACROSS THE SOUTHERN HALF OF THE LAKE. EAST
WINDS TO 30 KT ARE EXPECTED ACROSS THE NORTHERN HALF OF THE LAKE.
SOUTHEAST WINDS INCREASE TO 30 KT SUNDAY. A SMALL CRAFT ADVISORY
WILL BE NEEDED FOR SUNDAY POTENTIALLY THROUGH MONDAY
EVENING...HOWEVER THERE MAY BE A PERIOD OF GALES MONDAY SO WILL HOLD
OFF ON ISSUING A SMALL CRAFT ADVISORY NOW.
SOUTHEAST WINDS INCREASE TO LOW END GALES SUNDAY NIGHT. THE LOW
SHIFTS NORTH OVER WISCONSIN MONDAY WITH SOUTH TO SOUTHWEST GALES
MAINLY OVER THE SOUTHERN END OF THE LAKE. MAY SEE A FEW GALE FORCE
GUSTS ACROSS THE NORTHERN END. THE LOW PASSES OVER THE NORTHERN END
OF THE LAKE MONDAY EVENING AND NIGHT WITH WINDS BECOMING WEST BEHIND
IT. THE NEXT LOW FORMS OVER THE PLAINS TUESDAY. GUIDANCE SUGGESTS
THIS LOW WILL HAVE A SIMILAR PATH TO THE LOW THIS WEEKEND OR SHIFT
NORTH ACROSS MINNESOTA. EITHER WAY SOUTH TO SOUTHWEST WINDS
INCREASE TO AT LEAST 30 KT WEDNESDAY WITH GALES POSSIBLE ACROSS THE
SOUTHERN HALF OF THE LAKE. ANOTHER SMALL CRAFT ADVISORY MAY BE
NEEDED AS WELL. WEST WINDS 15-25 KT ARE THEN EXPECTED THROUGH LATE
NEXT WEEK.
JEE
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1156 PM CST FRI DEC 11 2015
.UPDATE...
ISSUED AT 859 PM CST FRI DEC 11 2015
A warm frontal feature is poised just north of I-64 approaching
central IL this evening with widespread low cloud cover and a few
reports of drizzle ahead of it through central IL. Behind the
front...some clearing at low levels is noted in the
observations...especially southwest of Springfield, and may need
to adjust forecasts to account for this. However...any clearing of
skies may lead to increased fog density. Otherwise...very warm
temperatures mainly in the 50s expected overnight...potentially
leading to a few record warm minimum temperatures.
&&
.SHORT TERM...(Tonight)
ISSUED AT 239 PM CST FRI DEC 11 2015
Overcast low clouds below 2k ft and patchy fog and drizzle lifting
northward from southern into central IL and reaching north of
Lincoln by mid afternoon. These low clouds and will overspread rest
of northern CWA next few hours. HRRR model has been handling this
quicker timing of arrival of IFR clouds well and even have a few
sites with vsbys below 1 mile with Paris the lowest at 1/2 mile in
fog. South to southeast winds advecting low level moisture northward
into central IL this afternoon and this to continue tonight with
patchy drizzle as well. Continue slight chances of light rain
showers over central and eastern IL tonight though mostly a trace
event tonight.
A 1000 mb surface low pressure over southeast Nebraska will weaken
to 1010 mb as it moves into south central IA by dawn Sat. One warm
front near I-74 to lift into northern IL tonight while another warm
front near I-70 will slowly lift northward across central IL
tonight. Weak lift along with boundary to develop very light
precipitation along with areas of fog and patchy drizzle especially
east of the IL river with very moist low levels from surface up to
850 mb. SSE winds 5-10 mph and low clouds will not allow temps to
drop too much tonight. Unseasonably mild lows range from around 50F
nw of the IL river to the upper 50s in southeast IL from I-70
southeast.
.LONG TERM...(Saturday through Friday)
ISSUED AT 239 PM CST FRI DEC 11 2015
Models finally in better agreement with timing of the approaching
system for this weekend. However, all models still have trended a
little slower with the system as it moves into and through the CWA.
Before the main system gets here, light, warm advection type pcpn
will move across the state during the day on Sat. This will include
cloudy skies and much warmer temps...with some sites reaching or
exceeding record temps. Then the main punch of the pcpn will begin
late Sat night and continue through Sunday and Sun night. Models
have also trended with less pcpn through the period, but still
showing around an inch in the east and over 1.5 inches west of I-55.
The heaviest pcpn looks to be Sun afternoon and Sun evening. The
pcpn will diminish on Monday, with just chance pops for mainly Mon
morning. By afternoon, things should push to the east and northeast.
Besides the record warmth on Sat, Sunday highs will also be quite
warm...well above normal for middle of Dec. Once the system moves
through, temps will decrease but still be above normal.
The main focus for next week, Mon night through Friday, will be the
slightly cooler temps and then the decreasing temps back to normal
for later in the week. With the upper level flow remaining
southwesterly in the extended, another wave or two will move
northeast through the flow. However, with the gulf being blocked,
there should be limited moisture in the area for any weak system to
work with. So, only slight chc pops expected for when the weak wave
moves through, which will be Tue night through Wed night. Besides
this, dry weather is expected most of the area through most of the
week.
Temps will stay above normal through about Wed and then fall to
around normal for the end of the week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Saturday night)
ISSUED AT 1156 PM CST FRI DEC 11 2015
Overcast ceilings mainly IFR-MVFR range from around KMQB-KPRG
northward with low level clearing to the south behind a warm
frontal boundary. Patchy dense fog to the north...and widespread
MVFR visibilities to the south. Overnight...KPIA-KBMI-KCMI will be
most likely to see dense fog with the boundary in the
vicinity...however patchy dense fog to the south will also be
possible. Some improvement in ceilings/visibility possible for
afternoon...but ceilings unlikely to rise much over lower-end
MVFR. Gradually trending toward better chances for light rain
showers after 15Z saturday as increasing moist southerly flow
develops. Winds primarily ESE 6-10 kts turning southerly
overnight after warm frontal passage.
&&
.CLIMATE...
ISSUED AT 300 AM CST FRI DEC 10 2015
Record highs for the weekend:
Location Today Saturday Sunday
DEC 11 DEC 12 DEC 13
---------- --------- --------- ---------
Bloomington 65 (1949) 65 (1896) 63 (1975)
Champaign 64 (1949) 62 (1991) 64 (1975)
Charleston 66 (1931) 67 (1949) 64 (1991)
Decatur 65 (1949) 65 (1929) 66 (1975)
Effingham 60 (1979) 67 (1929) 65 (1991)
Lincoln 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Onton
SHORT TERM...07
LONG TERM...Auten
AVIATION...Onton
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
714 PM EST SUN DEC 13 2015
.SYNOPSIS...
ISSUED AT 404 PM EST SUN DEC 13 2015
RAIN WILL OVERSPREAD THE AREA OVERNIGHT INTO AT LEAST MONDAY
MORNING AS A STRONG SYSTEM APPROACHES AND MOVES INTO THE UPPER
GREAT LAKES. WARM TEMPERATURES WILL CONTINUE INTO MONDAY MORNING.
THEN THE START OF A TRANSITION TO COOLER...BUT STILL ABOVE NORMAL
TEMPERATURES WILL BEGIN. BY FRIDAY MORE SEASONABLE TEMPERATURES
WILL SETTLE IN WITH TEMPERATURES FINALLY DROPPING TO AT OR BELOW
THE FREEZING MARK TOWARD THE END OF THE WORK WEEK.
&&
.UPDATE...
ISSUED AT 714 PM EST SUN DEC 13 2015
MODEST UPDATE TO CUT BACK/SLOW DOWN POPS FOR THE OVERNIGHT
PERIOD...MAINLY IN OUR SOUTHEAST HALF. INITIAL WING OF 295K
ISENTROPIC ASCENT CURRENTLY LIFTING NORTH AND EXPECT A RELATIVE
LULL IN STEADIER PRECIP FOR MOST OF OUR AREA THROUGH MUCH OF
TONIGHT AS THIS ACTIVITY LIFTS NORTH. A FEW LINGERING SHOWERS
POSSIBLE IN OUR NW HALF AS SUGGESTED BY LATEST HRRR BUT SE HALF
WILL LIKELY REMAIN DRY THROUGH 06-09Z. COLD FRONT WILL THEN SWEEP
FROM WEST TO EAST EARLY MONDAY MORNING WITH WIDESPREAD SHOWERS.
REST OF THE FORECAST REMAINS IN GOOD SHAPE. UPDATED ZFP WILL BE
OUT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 405 PM EST SUN DEC 13 2015
SOLID/DEEP NATURE OF CLOUD COVER HELD LINE ON TEMPS...DESPITE
RECORD/NEAR RECORD AT THIS TIME WITH TEMPS INTO MID 60S SERN
CWA/LWR 60S ELSEWHERE. STILL POTENTIAL FOR DEGREE/TWO RISE NEXT
HOUR AND CERTAINLY POTENTIAL FOR HIGHER EXISTED FOR A TIME.
PRIMARY FOCUS ONTO UPSTREAM STRONGLY DYNAMIC MID TROPOSPHERIC
SYSTEM OVER CENTRAL OKLAHOMA AS IT BEGINS ASSERTIVE NORTHEASTWARD
LIFTOUT. PRESENT ELEVATED COLD CONVEYOR BELT/OCCLUSION ASSOCIATED
RAIN SHIELD WITH EMBEDDED/SHALLOW CONVECTIVE ELEMENTS WILL
PRIMARILY LIFT NORTHWARD WITH FAR EASTERN PERIPHERY TO LIFT
THROUGH WESTERN THIRD OF CWA THIS EVENING. LATER TONIGHT
PSUEDO/SECONDARY COLD FRONT ASSOCIATED WITH FRONTAL WAVE
/PRESENTLY DEVELOPING OVER SOUTHERN MISSOURI/ TO PRESS NEWD INTO
CWA. CORE OF RICH THETA-E/MIXING RATIOS WITH PLUS 9 G/KG IN
1000-850MB LAYER TO SUPPORT SECOND ROUND OF SHRA PRESSING FARTHER
EAST INTO CWA AS EXTREME 70-75 KT 8H JET AXIS ROTATES CCW INTO
INDIANA. BEST FORCED LIFT APPEARS IN 060-09 UTC WINDOW.
THEREAFTER...SUSPECT OVERALL DIMINISHMENT IN COVERAGE/INTENSITY
BEYOND 12 UTC...THOUGH INFLUENCE OF EXTREME/250-300M/12 HR HEIGHT
FALL CENTROID OVER NERN IL MIDDAY ALONG WITH CWA POISED WITHIN
FAVORABLE EXIT REGION OF 120-130 KT JET CORE OVER WEST CENTRAL
OHIO SHOULD AID IN CONVECTIVE MAINTENANCE MONDAY MORNING. MOISTURE
DEPTH/PWAT LOWER REMARKABLY AS DEPTH OF MOISTURE/MID LEVEL DRY
SLOTTING OVERSPREADS W-E THROUGH AFTERNOON LIMITING AMOUNTS
THEREAFTER. PROGRESSIVE NATURE OF SYSTEM ASSURED WITH PRESS OF YET
ANOTHER STRONG UPSTREAM SYSTEM INTO GREAT BASIN BY 00 UTC TUE.
THIS AND DISJOINTED NATURE OF RAFL EPISODES TO LIMIT TOTAL QPF TO
AMOUNTS EASILY HANDLED BY BASIN DRAINAGE SYSTEM. TEMPERATURES NON
DIURNAL WITH EXTREMELY WARM OVERNIGHT LOWS IN WELL MIXED
HOMOGENEOUS BOUNDARY LAYER AND FALLING THROUGH DAY/EARLY HIGHS
MON.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 405 PM EST SUN DEC 13 2015
QUICK RECOVERY IN MID/UPPER LEVEL HEIGHTS IN WAKE OF EXITING
UPPER LOW WILL ALLOW TEMPS TO REMAIN ABOVE NORMAL INTO TUESDAY AND
WEDNESDAY AS WARM ADVECTION RESUMES IN ADVANCE OF THE NEXT UPPER
LOW/SFC REFLECTION TO EJECT NORTHEAST THROUGH THE UPPER MIDWEST.
THIS PROCESS WILL BRING AN END TO ANY PCPN MONDAY NIGHT THROUGH
TUESDAY NIGHT...ALTHOUGH SUBSIDENCE/DRYING NOT ALL THAT IMPRESSIVE
WITH WARMING OVER INVERSION LIKELY LOCKING IN LOW CLOUDS LONGER
THAN CURRENTLY MODELED. LIGHT RAIN SHOWER CHANCES THEN RETURN
WEDNESDAY INTO WEDNESDAY EVENING ALONG A COLD FRONT. KEPT POPS IN
LOW-MID CHANCE RANGE...HIGHEST ACROSS NW IN/SW MI...GIVEN LACKING
MOISTURE QUALITY/RETURN.
SOLID MODEL AGREEMENT REMAINS FOR A SHOT OF COLDER/SEASONABLE AIR
THURSDAY THROUGH SATURDAY AS LONGWAVE TROUGH PROGRESSES EAST
THROUGH EASTERN NOAM. THIS COLD FLOW OVER WARMER LAKE MI WATER
SUPPORTS LOW- MID CHANCE POPS FOR LAKE EFFECT SNOW SHOWERS IN
FAVORED WEST FLOW LE ZONES. WARMER AIR WILL THEN FILTER BACK INTO
THE REGION SUNDAY INTO EARLY NEXT WEEK AS HEIGHT FIELD RELAXES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 638 PM EST SUN DEC 13 2015
LEADING ROUND OF ISENTROPIC ASCENT BRINGING RAIN AND SOME LOWER
CEILINGS TO KSBN AT THIS TIME BUT EXPECT THIS ACTIVITY TO LIFT
NORTH IN THE NEXT FEW HOURS WITH VFR CONDITIONS FOR MOST OF THE
NIGHT. COLD FRONT WILL THEN CROSS THE AREA EARLY TOMORROW MORNING
WITH ANOTHER ROUND OF RAIN. LEFT IN MENTION OF BRIEF FUEL
ALTERNATE CRITERIA BUT COULD REMAIN HIGH-END MVFR. HIGH MVFR/LOW
VFR THEN EXPECTED FOR MUCH OF TOMORROW WITH SCT SHOWERS AS STACKED
LOW PRESSURE CROSSES THE GREAT LAKES.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LMZ043-046.
&&
$$
UPDATE...AGD
SYNOPSIS...MURPHY
SHORT TERM...MURPHY
LONG TERM...STEINWEDEL
AVIATION...AGD
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
356 PM CST SAT DEC 12 2015
.SYNOPSIS...
ISSUED AT 354 PM CST SAT DEC 12 2015
SFC WARM FRONT BISECTING CWA FROM SW TO NE ROUGHLY NEAR WASHINGTON
IA...TO QUAD CITIES...TO STERLING IL AXIS AT MID AFTN. TO SOUTH
OF THE FRONT NEAR RECORD WARMTH WITH HIGHS IN THE 60S WHILE TO THE
NORTH OF THE FRONT NOT AS WARM BUT STILL WELL ABOVE AVERAGE WITH
TEMPS RANGING FROM THE MID/UPPER 40S PORTIONS OF HWY 20 WHERE
AREAS OF FOG STILL BEING FOUND...TO THE MID/UPPER 50S NEAR HWY 30.
WATER VAPOR IMAGERY SHOWS AN UPPER LEVEL LOW SHIFTING EAST FROM
AZ INTO NM... WITH PLENTY OF MOISTURE WITH BOTH GULF AND PACIFIC
FEEDS STREAMING NORTHWARD.
&&
.SHORT TERM...(TONIGHT)
ISSUED AT 354 PM CST SAT DEC 12 2015
FRONTAL BOUNDARY TO STALL THIS EVE THEN BEGIN TO LIFT NWD OVRNGT
IN RESPONSE TO SFC LOW EMERGING AND STRENGTHENING IN THE SOUTHERN
PLAINS. MAY SEE SOME DENSE FOG REDEVELOP OR EXPAND NEAR/NORTH
OF THE FRONT THIS EVE AHEAD OF THE RAIN... AND SOMETHING TO WATCH
FOR POSSIBLE ADVISORY. DEEPER MOISTURE HAS BEEN SLOWER TO ARRIVE
THUS TIMING OF POPS DELAYED SOME BUT DO ANTICIPATE ATLEAST
SCATTERED SHOWERS DEVELOPING THIS EVENING INTO THE OVRNGT
NEAR/NORTH OF WARM FRONT WITH WARM ADVECTION... WITH BEST COVERAGE
FAVORED OVER NORTHWEST 1/3RD. WITH SLOWER ARRIVAL OF DEEPER MOISTURE
MEANS A BIT MORE MID LEVEL DRY AIR WHICH ALONG WITH STEEP LAPSE
RATES AND ELEVATED CAPE SUPPORTIVE OF AT LEAST ISOLD STORMS. CANT
RULE OUT SOME HAIL IN STRONGER CELLS WITH WBZ 9-10KFT AGL AND IF
SUFFICIENT MID LEVEL DRY AIR. LATE TONIGHT EXPECT SIGNIFICANT
RAMPING UP OF BOTH COVERAGE AND INTENSITY WITH STRONG CONVERGENCE ON
NOSE OF 60+ KT LOW LEVEL JET. POSSIBLY MORE COVERAGE OF STORMS TO
SCATTERED BASIS WITH CONTINUED POSSIBILITY FOR SOME HAIL IN
STRONGER CELLS AND BANKING ON ENOUGH BL STABILIZATION FOR LIMITED SFC
BASED POTENTIAL.
TEMPS SHOULD DROP A LITTLE INTO EARLY THIS EVE BEFORE STEADYING OUT
THEN EVEN RISING A BIT WITH WARM FRONT.
.LONG TERM...(SUNDAY THROUGH SATURDAY)
ISSUED AT 354 PM CST SAT DEC 12 2015
MAIN FORECAST CONCERN FOR THE LONG TERM WILL BE THE ONGOING RAIN AND
ISOLATED THUNDER ACROSS THE AREA AT 12Z TOMORROW. THE BEST CHANCES
FOR HEAVY RAIN APPEAR TO BE IN THE MORNING THEN AGAIN TOMORROW
EVENING AND OVERNIGHT. RAINFALL TOTALS OF 1 TO 3 INCHES APPEARS
POSSIBLE. SOME AREAS MAY SEE LOCALLY HIGHER AMOUNTS.
OVERALL TREND IN THE GUIDANCE IS FOR A SLOWING DOWN SYSTEM. THE NAM
SEEMS TO BE HANDLING THE CURRENT LOCATION OF THE MOISTURE WELL. THE
SPECTRAL MODELS APPEARS TO BE CREATING LARGER AREAS OF PRECIP ALONG
WITH A FASTER MOVEMENT. OVERALL CONSENSUS EXISTS BETWEEN THE
GUIDANCE THAT A STRONG H85 JET TERMINUS WILL BE OVER THE AREA AT 12Z
AND MOVE TO THE EAST THROUGH THE DAY. THIS JET...PAIRED WITH A
SLOWER SYSTEM SUGGESTS THAT A BETTER CHANCE FOR THUNDERSTORMS AND
RAIN EXISTS IN THE MORNING AS THE JET MOVES THROUGH THE AREA. STRONG
LOW LEVEL SHEAR ALONG WITH DEEP LAYER SHEAR WILL LEAD TO STRONGER
UPDRAFTS IN ANY CONVECTIVE ELEMENTS. THE ADDITIONAL FORCING ALONG
THE NOSE OF THE JET SHOULD BE ENOUGH FOR ISOLATED THUNDER AS STRONG
ENOUGH UPDRAFTS SHOULD BRING SUPER COOLED WATER INTO THE MIXED PHASE
REGION OF THE STORMS...LEADING TO CHARGE SEPARATION FOR IC
LIGHTNING. THE THUNDER THREAT SHOULD MIGRATE NORTH AND EAST THROUGH
THE MORNING ALONG THE NOSE OF THE H85 JET.
THE NAM...HIRES MODELS AND GFS 20 KM MODELS SUGGEST A LULL IN THE
ACTIVITY TOMORROW LATE MORNING THROUGH THE AFTERNOON. THEN ANOTHER
SHOT OF RAIN STARTS UP. BETWEEN 21Z SUNDAY AND 06Z MONDAY IT
APPEARS THAT THE HEAVIEST RAIN WILL FALL. THIS GRADUALLY MOVE TO
THE NORTH AS THE CLEAR SLOT WORKS ITS WAY IN. GUIDANCE HAS BEEN
CONSISTENT WITH THE LACK OF COLD AIR ROTATING IN BEHIND THIS SYSTEM.
THIS MEANS THAT RAIN WILL BE THE MAIN PRECIP TYPE. WHEN EVERYTHING
IS SAID AND DONE WE COULD SEE 1 TO 3 INCHES WITH ISOLATED HIGHER
AMOUNTS POSSIBLE. WITH ALL OF THE RAINFALL WE HAVE HAD AND FORECAST
WE MAY START TO SEE HYDRO CONCERNS ON AREA RIVERS.
ONCE THIS SYSTEM MOVES THROUGH...ANOTHER VORT MAX ROTATES THROUGH
THE PLAINS. TEMPERATURES ARE COOLER AND IT LOOKS LIKE WE MAY SEE A
RAIN/SNOW MIX ACROSS THE NORTH TUESDAY NIGHT INTO WEDNESDAY. ON
WEDNESDAY...TEMPS WARM ENOUGH TO CAUSE ANY PRECIP TO BE ALL RAIN.
ONCE THIS SYSTEM MOVES THROUGH. COOLER AIR...MORE SEASONABLE
AIR...MAKES ITS WAY INTO THE AREA FOR LATER THIS WEEK AND NEXT
WEEKEND.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 354 PM CST SAT DEC 12 2015
FRONT TO STALL THIS EVENING THEN LIFT NORTH OVERNIGHT AS WARM
FRONT WITH LOW PRESSURE MOVING INTO THE PLAINS. LIKELY WILL
SEE CONDITIONS IN FOG AND LOW CLOUDS DETERIORATE BACK TO IFR WITH
LIFR/VLIFR ALONG/N OF BOUNDARY IMPACTING MAINLY DBQ AND CID.
ISENTROPIC LIFT OVER BOUNDARY WILL ALSO PROVIDE SOME SCATTERED
SHOWER ACTIVITY THIS EVENING INTO THE OVERNIGHT AND HAVE HANDLED
WITH VCSH. LATE TONIGHT THROUGH MID MORNING SUNDAY... EXPECT
WIDESPREAD SHOWERS AND FEW-SCTD STORMS WITH STRONG CONVERGENCE ON
NOSE OF 60+ KT LOW LEVEL JET... WITH CONDITIONS GENERALLY MVFR TO
IFR. THIS PRECIPITATION SHOULD HELP TO SCOUR OUT ANY DENSE FOG AND
VLIFR CONDITIONS. LATER SHIFTS WILL NEED TO LOOK AT ADDING MENTION
OF LLWS LATE TONIGHT AND EARLY SUNDAY MORNING AS NAM SHOWS 40-45+
KTS FROM THE SOUTHEAST IN 1500-2000FT AGL LAYER. RAP MODEL THOUGH
NOT AS STRONG ONLY AROUND 30 KTS AND MORE MARGINAL CRITERIA WITH
SFC WINDS LIKELY SUSTAINED AROUND 10-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 354 PM CST SAT DEC 12 2015
RAINFALL TONIGHT INTO LATE SUNDAY NIGHT SHOULD TOTAL 1 TO 2 INCHES WITH
LOCAL AMOUNTS NEAR 2.5 INCHES POSSIBLE IN NW SECTIONS OF THE REGION.
THE LONG DURATION SHOULD LIMIT WATER ISSUES INITIALLY TO PONDING IN
LOW LYING AND POORLY DRAINED AREAS. OUR ALREADY WET SOILS WILL RESULT IN
SIGNIFICANT RUNOFF INTO THE LOCAL RIVERS.
AT THIS TIME...AREAS THAT RECEIVE OVER 1.5 INCHES OR MORE OF RAIN MAY
SEE SOME RIVERS REACH BANKFULL. AREA RIVER BASINS THAT RECEIVE AROUND
2 INCHES OR MORE MAY HAVE SOME RIVERS REACH MINOR TO POSSIBLY BRIEFLY
MODERATE RIVER FLOODING EARLY NEXT WEEK. SPECIFIC RIVER LOCATIONS WILL
BE BETTER KNOWN IN THE NEXT 12-24 HOURS AS THE LOCATIONS OF HEAVIEST
RAINFALL ARE CLARIFIED.
&&
.CLIMATE...
ISSUED AT 354 PM CST SAT DEC 12 2015
RECORD WARM LOWS FOR DECEMBER 13...
DUBUQUE........38 IN 1918
MOLINE.........40 IN 1928
RECORD HIGHS FOR DECEMBER 13...
MOLINE.........63 IN 1975
CEDAR RAPIDS...57 IN 1975
DUBUQUE........55 IN 1920
BURLINGTON.....64 IN 1975
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...MCCLURE
SHORT TERM...MCCLURE
LONG TERM...GIBBS
AVIATION...MCCLURE
HYDROLOGY...08/MCCLURE
CLIMATE...MCCLURE
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1218 PM CST SAT DEC 12 2015
.UPDATE...
ISSUED AT 1203 PM CST SAT DEC 12 2015
SOME DENSE FOG LINGERS NORTHWEST OF IOWA CITY TO FREEPORT AXIS
BUT MOSTLY PATCHY AND WITH IMPROVING TRENDS NOTED LIFTING FROM
THE SOUTH HAVE ALLOWED THE DENSE FOG ADVISORY TO EXPIRE. WITH
LITTLE CHANGE IN CONDITIONS WE MAY SEE SOME REDEVELOPMENT OF
DENSE FOG THIS EVENING IN THESE SAME AREAS NEAR/NORTH OF STALLED
FRONTAL ZONE.
&&
.SYNOPSIS...
ISSUED AT 250 AM CST SAT DEC 12 2015
06Z SFC DATA HAS A WEAK LOW SOUTH OF KDSM WITH A FRONTAL BOUNDARY
RUNNING EAST INTO ILLINOIS JUST SOUTH OF I-80. A COLD FRONT RAN FROM
THE LOW INTO NORTHERN OKLAHOMA. DEW POINTS WERE IN THE 50S AND 60S
FROM THE SOUTHERN GREAT LAKES TO THE GULF COAST WITH 30S AND 40S
FROM THE UPPER MIDWEST INTO THE PLAINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CST SAT DEC 12 2015
RECORD WARM LOWS ARE VERY POSSIBLE TODAY AND SUNDAY. REFER TO THE
CLIMATE SECTION FOR SPECIFIC INFORMATION.
THE DENSE FOG ADVISORY WAS EXPANDED TO ENCOMPASS ROUGHLY THE WESTERN
HALF OF THE AREA THROUGH THE MORNING HOURS. THE POSSIBILITY DOES
EXIST THAT IT MAY NEED TO BE EXPANDED FURTHER EAST WITH THE FRONTAL
BOUNDARY AND WEAK WINDS ACROSS THE AREA. WILL CONTINUE TO MONITOR
FOR THIS POSSIBILITY.
MAINLY DRY CONDITIONS WILL BE SEEN ACROSS THE AREA THIS MORNING.
DURING THE AFTERNOON...ADDITIONAL MOISTURE MOVES INTO THE AREA AND
THE FORCING...ALBEIT WEAK...GETS SLIGHTLY STRONGER. WITH THE
ATMOSPHERE MORE SATURATED...SPRINKLES OR VERY LIGHT RAIN SHOULD
SLOWLY BREAK OUT DURING THE AFTERNOON. TEMPERATURES WILL BE
UNSEASONABLY MILD WITH HIGHS 20 TO 25 DEGREES ABOVE NORMAL.
TONIGHT...MOISTURE/FORCING INCREASES CONSIDERABLY ACROSS THE AREA.
RAIN WILL QUICKLY DEVELOP AND EXPAND IN AREAL COVERAGE DURING THE
EVENING HOURS. STARTING AROUND MIDNIGHT AND CONTINUING THROUGH
SUNRISE FORCING BECOMES VERY STRONG AS ANOTHER SURGE OF MOISTURE
MOVES INTO THE AREA. THIS FORCING/MOISTURE SHOULD BE ENOUGH TO ALLOW
SOME ISOLATED THUNDERSTORMS TO DEVELOP OVER MOST OF THE AREA PRIOR
TO SUNRISE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 250 AM CST SAT DEC 12 2015
SIGNIFICANT RAINS SUNDAY AND SUNDAY NIGHT THE MAIN FORECAST ISSUE.
LONG TERM FORECAST CONFIDENCE ASSESSMENT...GOOD OR ABOVE AVERAGE WITH
LOCATIONS OF HEAVIEST RAIN TOTALS THE BIGGEST ISSUE. NEAR RECORD PRECIPITABLE
WATER VALUES...DEEP SATURATION SUGGEST VERY EFFICIENT RAINFALL PROCESSES
EXPECTED SO AREAS OF 2 INCHES OF RAIN SHOULD OCCUR WITH PROLONGED FORCING
AND PRECIPITABLE WATER VALUES OF 1.2 UP TO NEARLY 1.5 INCHES.
OVERVIEW...INITIALIZATION AND VERIFICATION ARE GOOD WITH NORMAL SLIGHTLY
TOO MOIST BL BIAS IN AMERICAN SOLUTIONS. HI-RES ECMWF ONCE AGAIN MORE
CONSISTENT BOTH IN RUN TO RUN AND IN HANDLING OF LOW LEVEL MOISTURE
FIELDS. PREFER A 60/40 MIX OF HI-RES ECMWF TO GFS. LITTLE SENSIBLE WEATHER
ISSUES ONCE PAST MONDAY AFTERNOON.
SUNDAY AND SUNDAY NIGHT...AREAS OF RAIN...MODERATE AT TIMES TO FALL
INTO THE OVERNIGHT HOURS. RAINFALL RATES SHOULD TEND TO BE IN THE TENTH
TO THREE TENTHS OF AN HOUR WILL RESULT IN PONDING OF WATER INITIALLY.
DESPITE RAINS...HIGHS SHOULD BE NEAR RECORD TO RECORD FOR WARMTH. LOCAL
"LIFT" TOOL DOES SUGGEST A RUMBLE OF THUNDER MAY BE POSSIBLE SUNDAY
AM BUT WILL LEAVE OUT AT THIS TIME. SUNDAY NIGHT...AREAS OF RAIN TO
DIMINISH TOWARD DAYBREAK WITH PASSAGE OF UPPER AND SURFACE LOW. MINS
SHOULD BE AROUND 8 AM...MOSTLY IN THE LOWER TO MIDDLE 40S.
MONDAY...LIGHT RAIN TO SLOWLY DIMINISH WITH BREEZY WESTERLY WINDS AND
TEMPERATURES NEARLY STEADY ALL DAY. ADDITIONAL RAIN TOTALS SHOULD
BE LIGHT AND SPOTTY IN THE ONE TENTH OF AN INCH RANGE OR LESS.
TUESDAY THROUGH FRIDAY...STILL ABOVE NORMAL TEMPERATURES INTO WEDNESDAY
AND THEN NEAR NORMAL. DRY TO MOSTLY DRY CONDITIONS WITH HIGHS MOSTLY
4OS THROUGH WEDNESDAY AND 30S FOR THURSDAY AND FRIDAY. LOWS 30S INTO
WEDNESDAY MORNING AND FALLING INTO THE TEENS AND 20S FOR THURSDAY AND
FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1203 PM CST SAT DEC 12 2015
WARM FRONT LIFTING NORTH WILL BRING SOME IMPROVEMENT IN
CONDITIONS THIS AFTERNOON WITH VFR MAINLY AT BRL AND MLI... AND
IFR TO MVFR AT CID AND DBQ. FRONT LIKELY TO STALL BY THIS EVENING
AS NEXT LOW PRESSURE SYSTEM DEVELOPS AND RIDES ALONG IT. LIKELY
SEE CONDITIONS IN FOG AND LOW CLOUDS DETERIORATE BACK TO IFR WITH
LIFR/VLIFR ALONG/N OF BOUNDARY IMPACTING MAINLY DBQ AND CID.
ISENTROPIC LIFT OVER BOUNDARY WILL ALSO PROVIDE SOME SCATTERED
SHOWER ACTIVITY THIS EVENING INTO THE OVERNIGHT AND HAVE HANDLED
WITH VCSH. LATE TONIGHT THROUGH MID MORNING SUNDAY... EXPECT
WIDESPREAD SHOWERS AND FEW-SCTD STORMS WITH STRONG CONVERGENCE ON
NOSE OF 60+ KT LOW LEVEL JET... WITH CONDITIONS GENERALLY MVFR TO
IFR. THIS PRECIPITATION SHOULD HELP TO SCOUR OUT ANY DENSE FOG AND
VLIFR CONDITIONS. LATER SHIFTS WILL NEED TO LOOK AT ADDING MENTION
OF LLWS LATE TONIGHT AND EARLY SUNDAY MORNING AS NAM SHOWS 40-45+
KTS FROM THE SOUTHEAST IN 1500-2000FT AGL LAYER. RAP MODEL THOUGH
NOT AS STRONG ONLY AROUND 30 KTS AND MORE MARGINAL CRITERIA WITH
SFC WINDS LIKELY SUSTAINED AROUND 10-15 KTS.
&&
.HYDROLOGY...
ISSUED AT 250 AM CST SAT DEC 12 2015
RAIN FALLING OVER A 30 PLUS HOUR TIME SATURDAY NIGHT INTO LATE SUNDAY
NIGHT SHOULD TOTAL 1 TO 2 INCHES WITH LOCAL AMOUNTS NEAR 2.5 INCHES
POSSIBLE IN NW SECTIONS OF THE REGION. THE LONG DURATION SHOULD LIMIT
WATER ISSUES INITIALLY TO PONDING IN LOW LYING AND POORLY DRAINED AREAS.
OUR ALREADY WET SOILS WILL RESULT IN SIGNIFICANT RUNOFF INTO THE LOCAL
RIVERS.
AT THIS TIME...AREAS THAT RECEIVE OVER 1.5 INCHES OR MORE OF RAIN MAY
SEE SOME RIVERS REACH BANKFULL. AREA RIVER BASINS THAT RECEIVE AROUND
2 INCHES OR MORE MAY HAVE SOME RIVERS REACH MINOR TO POSSIBLY BRIEFLY
MODERATE RIVER FLOODING EARLY NEXT WEEK. SPECIFIC RIVER LOCATIONS WILL
BE BETTER KNOWN IN THE NEXT 12-24 HOURS AS THE LOCATIONS OF HEAVIEST
RAINFALL ARE CLARIFIED.
&&
.CLIMATE...
ISSUED AT 250 AM CST SAT DEC 12 2015
RECORD HIGHS FOR DECEMBER 12...
MOLINE.........65 IN 1991
CEDAR RAPIDS...57 IN 1991
DUBUQUE........58 IN 1913
BURLINGTON.....66 IN 1991
RECORD WARM LOWS FOR DECEMBER 13...
DUBUQUE........38 IN 1918
MOLINE.........40 IN 1928
RECORD HIGHS FOR DECEMBER 13...
MOLINE.........63 IN 1975
CEDAR RAPIDS...57 IN 1975
DUBUQUE........55 IN 1920
BURLINGTON.....64 IN 1975
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...05
SYNOPSIS...08
SHORT TERM...08
LONG TERM...NICHOLS
AVIATION...05
HYDROLOGY...NICHOLS
CLIMATE...NICHOLS
AREA FORECAST DISCUSSION
NWS WICHITA KS
1213 PM CST SAT DEC 12 2015
...UPDATED FOR 18Z AVIATION DISCUSSION...
.UPDATE...
ISSUED AT 1027 AM CST SAT DEC 12 2015
FRONTAL BOUNDARY IS A LITTLE FURTHER SOUTH THAN PREVIOUSLY
ANTICIPATED AT THIS TIME. WITH THE BOUNDARY GENERALLY LOCATED FROM
ANTHONY TO KIAB TO EL DORADO NEAR KEMP. THE RICHER GULF MOISTURE
LURKS JUST TO THE SOUTH OF THIS BOUNDARY...WITH LOW 60 DWPTS IN SE
AND SOUTH CENTRAL KS. EVEN SEEING LOW 60 DWPTS NEAR KWLD AND EL
DORADO.
THE QUESTION TODAY IS WHAT WILL HAPPEN TO THIS FRONT AS THE
AFTERNOON PROGRESSES...AS THIS WILL IMPACT LOCATION OF ANY SEVERE
STORM CHANCES FOR THIS EVENING...WITH THE BEST CHANCE FOR ANY SEVERE
STORMS THIS FAR NORTH...BEING IN THE WARM SECTOR. LATEST HI-RES
SHORT TERM HRRR AND RAP SEEM TO HAVE THE BEST HANDLE ON THE CURRENT
FRONTAL POSITION...GRADUALLY SLOSHING THE FRONT BACK TO THE NW AS
THE AFTERNOON PROGRESSES...BACK THROUGH KICT AND JUST NW OF THE KS
TURNPIKE BY LATE THIS AFTERNOON INTO THIS EVENING. THIS WILL PUT
SOME OF OUR SOUTHERN COUNTIES BACK IN THE WARM SECTOR. EVEN WITH THE
HIGHER DEWPOINT AIR IN PLACE...INSTABILITY WILL BE LIMITED...GIVEN
THE WIDESPREAD CLOUD COVER LIMITING THE HEATING/DESTABILIZING OF THE
ATMOSPHERE. BUT SHEAR OF 60-70 KTS WILL HELP OVERCOME THE LOWER
INSTABILITY VALUES FOR A HIGH SHEAR/LOW CAPE SEVERE WEATHER
THREAT...ESPECIALLY FOR COUNTIES JUST TO THE SOUTH OF KICT. THINK
STORMS WILL HOLD OFF UNTIL 22-00Z...TO THE SOUTH OF THE KS/OK
LINE...BUT EXPECT THE STORMS TO RACE RAPIDLY TO NORTH-NORTHEAST INTO
SOUTHERN KS AFTER SUNSET. POTENTIAL STILL EXISTS FOR SOME ELONGATED
FAST MOVING SUPERCELLS...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN
CONCERNS IN THE WARM SECTOR (MAINLY ALONG OR SE OF THE KS TURNPIKE)
AS THE LOW LEVEL JET INCREASES THIS EVENING...COULD EVEN SEE SURFACE
WINDS BACK TO THE SE ALONG THE KS/OK BORDER...WHICH COULD CREATE
ENOUGH DIRECTIONAL SHEAR IN THE LOWEST 1KM FOR AN OUTSIDE SHOT AT
TORNADO OR TWO TO DEVELOP NEAR THE KS/OK BORDER. THINK THE TORNADO
CHANCE IS VERY LOW...BUT STILL WORTH A MENTION. IF A TORNADO CAN GET
GOING IT WILL BE SHORT LIVED.
AS THE THUNDERSTORMS MOVE FURTHER NORTH...INTO KS...HAIL UP TO
QUARTER SIZE IS THE MAIN CONCERN IN THE WARM SECTOR. COULD ALSO SEE
SOME ELEVATED STORMS OVER THE TOP OF THE BOUNDARY INTO CENTRAL
KS...WHICH MAY LEAD TO SOME SMALL HAIL AND GUSTY WINDS.
PLAN ON KEEPING THE WINTER STORM WATCH FOR CENTRAL KS FOR NOW...WITH
THE HEAVIEST SNOW CHANCES STILL MAINLY TO THE WEST OF CENTRAL KS.
BUT GIVEN THE UNCERTAINTY IN THE AXIS OF HEAVY SNOW...WILL KEEP THE
CURRENT WATCH GOING.
KETCHAM
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 220 AM CST SAT DEC 12 2015
A VIGOROUS MID/UPPER TROUGH OVER THE SOUTHWEST IS PROGGED TO MOVE
OVER THE SOUTHERN ROCKIES TODAY AND EMERGE OVER THE SOUTHERN AND
CENTRAL PLAINS ON SUNDAY. AHEAD OF THIS SYSTEM...RICH GULF MOISTURE
WILL ARRIVE SETTING THE STAGE FOR A PERIOD OF STRONG TO PERHAPS
SEVERE STORMS THIS EVENING AND TONIGHT ACROSS SOUTH CENTRAL AND
SOUTHEAST KS. THE BEST CHANCE FOR STORMS SHOULD ARRIVE OVERNIGHT
WHEN THE LLJ NOSES INTO THE CENTRAL PLAINS STATES AND LARGE-SCALE
FORCING FOR ASCENT INCREASES AS THE MID/UPPER TROUGH MOVES OVER THE
SOUTHERN HIGHS PLAINS REGION. PWATS ARE ALSO PROGGED TO CLIMB TO
NEAR RECORD VALUES IN THE 1.25-1.5 INCH RANGE SUPPORTING LOCALLY
HEAVY RAIN AND LOCALIZED FLOODING CONCERNS.
AS THE COLD AIR DEEPENS TOWARD MID DAY OR EARLY AFTERNOON ON
SUNDAY...RAIN WILL RAPIDLY TRANSITION TO SNOW ACROSS CENTRAL KS. THE
NAM IS IN BETTER AGREEMENT WITH THE ECMWF AND GFS WITH THE TRACK OF
THE MID/UPPER TROUGH ACROSS THE REGION ON SUNDAY. THE ECMWF HAS HAD
MUCH BETTER RUN-TO-RUN CONSISTENCY AND REMAINS A BIT SLOWER AND
FURTHER SOUTH COMPARED TO THE NAM/GFS. CONFIDENCE IN A PERIOD OF
HEAVY SNOW IS BEGINNING TO INCREASE ACROSS PORTIONS OF CENTRAL KS ON
SUNDAY AFTERNOON AND SUNDAY EVENING AS THE SOUTHERN PERIPHERY OF THE
TROWAL AIRSTREAM MAY IMPACT THE NORTHWEST CORNER OF OUR FORECAST
AREA LEADING TO HIGHER SNOWFALL ACCUMULATIONS. GOOD LIFT THROUGH THE
DENDRITIC SNOW GROWTH REGION SHOULD RESULT IN HIGH SLRS AND
EFFICIENT SNOWFALL ACCUMULATIONS POSSIBLY EXCEEDING 5-7 INCHES
THROUGH SUNDAY NIGHT AND A WINTER STORM WATCH WILL BE ISSUED FOR
SUNDAY AFTERNOON AND SUNDAY NIGHT ACROSS PORTIONS OF CENTRAL KS.
THE SYSTEM IS EXPECTED TO LIFT FAIRLY RAPIDLY NORTH AND EAST AWAY
FROM THE AREA ON MONDAY WITH CLEARING SKIES AND RISING TEMPERATURES
ANTICIPATED BY AFTERNOON.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 220 AM CST SAT DEC 12 2015
ANOTHER FAST MOVING STORM SYSTEM WILL IMPACT THE CENTRAL ROCKIES
AND NORTHERN PLAINS STATES ON TUESDAY. BREEZY WESTERLY WINDS AND
PERHAPS AN ISOLATED SHOWER OR SNOW FLURRY MAY IMPACT PORTIONS OF
CENTRAL KS...ALTHOUGH LARGE-SCALE FORCING FOR SUBSIDENCE ON THE
SOUTHERN PERIPHERY OF THE MID/UPPER TROUGH SHOULD KEEP MUCH OF THE
AREA DRY. A MEAN MID/UPPER TROUGH IS PROGGED TO REMAIN SITUATED
ACROSS THE CENTRAL CONUS THROUGH THE REMAINDER OF THE PERIOD
RESULTING IN MOSTLY DRY WEATHER CONDITIONS AND SEASONABLY COOL
TEMPERATURES..
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1213 PM CST SAT DEC 12 2015
VERY CHALLENGING AVIATION FORECAST...AS A FRONTAL BOUNDARY IS
SITUATED RIGHT ACROSS THE CENTER OF THE FORECAST AREA....ROUGHLY
FROM KIAB TO NEAR KEMP. RICH BOUNDARY LAYER MOISTURE JUST TO THE
SOUTH OR ALONG THE BOUNDARY HAS LED TO A TRANSIENT AREA OF 1-4SM BR
SLOSHING ACROSS THE KICT AND KHUT TAF SITES. EVEN SEEING SOME OBS
SHOW SOME 1/2SM FG NEARBY...AS THIS RICH MOISTURE COLLIDES WITH THE
COOLER AIR TO THE NORTH OF THE BOUNDARY. THICK STRATUS CLOUDS HAVE
LED TO PREVAILING IFR CIGS AS WELL...WITH EVEN SOME LIFR CIGS NEAR
KICT. NORTH OF THE FRONT IN THE COOLER AIR...THE DEEP MOISTURE IS
ALSO LEADING TO IFR CIGS AS WELL.
EXPECT THE IFR AND POTENTIALLY LIFR CIGS TO CONTINUE ALONG THE
BOUNDARY FOR MOST OF THE DAY AS THE COLD FRONT DRIFTS BACK TO THE
NORTH SOME. AS THE AFTERNOON PROGRESSES INTO THE EVENING...A
VIGOROUS STORM SYSTEM WILL MOVE INTO THE SRN PLAINS...WHICH WILL
LEAD TO SHRA/TSRA DEVELOPING ACROSS THE AREA...ESPECIALLY IN THE
WARM SECTOR EAST OF THE KS TURNPIKE. SO WILL GO WITH A SHRA AND VCTS
MENTION FOR MOST LOCATIONS THIS EVENING.
AS THIS SYSTEM LIFT NORTHEAST ACROSS THE FORECAST AREA...EXPECT THE
SHRA/TSRA TO TRANSITION TO MORE OF A STEADY RAIN. WITH THE STEADY
RAIN...EXPECT WIDESPREAD MVFR/IFR CIGS WITH THE RAIN.
KETCHAM
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 48 47 32 55 / 100 80 40 0
HUTCHINSON 43 44 31 50 / 100 80 60 0
NEWTON 47 47 31 52 / 100 80 40 0
ELDORADO 52 51 32 55 / 100 80 30 0
WINFIELD-KWLD 51 52 33 56 / 100 90 30 0
RUSSELL 36 37 28 46 / 80 80 70 0
GREAT BEND 37 37 29 46 / 80 80 70 0
SALINA 44 43 30 46 / 90 80 70 0
MCPHERSON 44 44 30 48 / 100 80 60 0
COFFEYVILLE 61 60 37 56 / 100 90 30 0
CHANUTE 60 59 36 55 / 100 90 30 10
IOLA 60 59 36 53 / 100 90 30 10
PARSONS-KPPF 60 60 37 56 / 100 90 30 0
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
NIGHT FOR KSZ032-033-047.
&&
$$
AREA FORECAST DISCUSSION
NWS WICHITA KS
1028 AM CST SAT DEC 12 2015
.UPDATE...
ISSUED AT 1027 AM CST SAT DEC 12 2015
FRONTAL BOUNDARY IS A LITTLE FURTHER SOUTH THAN PREVIOUSLY
ANTICIPATED AT THIS TIME. WITH THE BOUNDARY GENERALLY LOCATED FROM
ANTHONY TO KIAB TO EL DORADO NEAR KEMP. THE RICHER GULF MOISTURE
LURKS JUST TO THE SOUTH OF THIS BOUNDARY...WITH LOW 60 DWPTS IN SE
AND SOUTH CENTRAL KS. EVEN SEEING LOW 60 DWPTS NEAR KWLD AND EL
DORADO.
THE QUESTION TODAY IS WHAT WILL HAPPEN TO THIS FRONT AS THE
AFTERNOON PROGRESSES...AS THIS WILL IMPACT LOCATION OF ANY SEVERE
STORM CHANCES FOR THIS EVENING...WITH THE BEST CHANCE FOR ANY SEVERE
STORMS THIS FAR NORTH...BEING IN THE WARM SECTOR. LATEST HI-RES
SHORT TERM HRRR AND RAP SEEM TO HAVE THE BEST HANDLE ON THE CURRENT
FRONTAL POSITION...GRADUALLY SLOSHING THE FRONT BACK TO THE NW AS
THE AFTERNOON PROGRESSES...BACK THROUGH KICT AND JUST NW OF THE KS
TURNPIKE BY LATE THIS AFTERNOON INTO THIS EVENING. THIS WILL PUT
SOME OF OUR SOUTHERN COUNTIES BACK IN THE WARM SECTOR. EVEN WITH THE
HIGHER DEWPOINT AIR IN PLACE...INSTABILITY WILL BE LIMITED...GIVEN
THE WIDESPREAD CLOUD COVER LIMITING THE HEATING/DESTABILIZING OF THE
ATMOSPHERE. BUT SHEAR OF 60-70 KTS WILL HELP OVERCOME THE LOWER
INSTABILITY VALUES FOR A HIGH SHEAR/LOW CAPE SEVERE WEATHER
THREAT...ESPECIALLY FOR COUNTIES JUST TO THE SOUTH OF KICT. THINK
STORMS WILL HOLD OFF UNTIL 22-00Z...TO THE SOUTH OF THE KS/OK
LINE...BUT EXPECT THE STORMS TO RACE RAPIDLY TO NORTH-NORTHEAST INTO
SOUTHERN KS AFTER SUNSET. POTENTIAL STILL EXISTS FOR SOME ELONGATED
FAST MOVING SUPERCELLS...WITH LARGE HAIL AND DAMAGING WINDS THE MAIN
CONCERNS IN THE WARM SECTOR (MAINLY ALONG OR SE OF THE KS TURNPIKE)
AS THE LOW LEVEL JET INCREASES THIS EVENING...COULD EVEN SEE SURFACE
WINDS BACK TO THE SE ALONG THE KS/OK BORDER...WHICH COULD CREATE
ENOUGH DIRECTIONAL SHEAR IN THE LOWEST 1KM FOR AN OUTSIDE SHOT AT
TORNADO OR TWO TO DEVELOP NEAR THE KS/OK BORDER. THINK THE TORNADO
CHANCE IS VERY LOW...BUT STILL WORTH A MENTION. IF A TORNADO CAN GET
GOING IT WILL BE SHORT LIVED.
AS THE THUNDERSTORMS MOVE FURTHER NORTH...INTO KS...HAIL UP TO
QUARTER SIZE IS THE MAIN CONCERN IN THE WARM SECTOR. COULD ALSO SEE
SOME ELEVATED STORMS OVER THE TOP OF THE BOUNDARY INTO CENTRAL
KS...WHICH MAY LEAD TO SOME SMALL HAIL AND GUSTY WINDS.
PLAN ON KEEPING THE WINTER STORM WATCH FOR CENTRAL KS FOR NOW...WITH
THE HEAVIEST SNOW CHANCES STILL MAINLY TO THE WEST OF CENTRAL KS.
BUT GIVEN THE UNCERTAINTY IN THE AXIS OF HEAVY SNOW...WILL KEEP THE
CURRENT WATCH GOING.
KETCHAM
&&
.SHORT TERM...(TODAY THROUGH MONDAY)
ISSUED AT 220 AM CST SAT DEC 12 2015
A VIGOROUS MID/UPPER TROUGH OVER THE SOUTHWEST IS PROGGED TO MOVE
OVER THE SOUTHERN ROCKIES TODAY AND EMERGE OVER THE SOUTHERN AND
CENTRAL PLAINS ON SUNDAY. AHEAD OF THIS SYSTEM...RICH GULF MOISTURE
WILL ARRIVE SETTING THE STAGE FOR A PERIOD OF STRONG TO PERHAPS
SEVERE STORMS THIS EVENING AND TONIGHT ACROSS SOUTH CENTRAL AND
SOUTHEAST KS. THE BEST CHANCE FOR STORMS SHOULD ARRIVE OVERNIGHT
WHEN THE LLJ NOSES INTO THE CENTRAL PLAINS STATES AND LARGE-SCALE
FORCING FOR ASCENT INCREASES AS THE MID/UPPER TROUGH MOVES OVER THE
SOUTHERN HIGHS PLAINS REGION. PWATS ARE ALSO PROGGED TO CLIMB TO
NEAR RECORD VALUES IN THE 1.25-1.5 INCH RANGE SUPPORTING LOCALLY
HEAVY RAIN AND LOCALIZED FLOODING CONCERNS.
AS THE COLD AIR DEEPENS TOWARD MID DAY OR EARLY AFTERNOON ON
SUNDAY...RAIN WILL RAPIDLY TRANSITION TO SNOW ACROSS CENTRAL KS. THE
NAM IS IN BETTER AGREEMENT WITH THE ECMWF AND GFS WITH THE TRACK OF
THE MID/UPPER TROUGH ACROSS THE REGION ON SUNDAY. THE ECMWF HAS HAD
MUCH BETTER RUN-TO-RUN CONSISTENCY AND REMAINS A BIT SLOWER AND
FURTHER SOUTH COMPARED TO THE NAM/GFS. CONFIDENCE IN A PERIOD OF
HEAVY SNOW IS BEGINNING TO INCREASE ACROSS PORTIONS OF CENTRAL KS ON
SUNDAY AFTERNOON AND SUNDAY EVENING AS THE SOUTHERN PERIPHERY OF THE
TROWAL AIRSTREAM MAY IMPACT THE NORTHWEST CORNER OF OUR FORECAST
AREA LEADING TO HIGHER SNOWFALL ACCUMULATIONS. GOOD LIFT THROUGH THE
DENDRITIC SNOW GROWTH REGION SHOULD RESULT IN HIGH SLRS AND
EFFICIENT SNOWFALL ACCUMULATIONS POSSIBLY EXCEEDING 5-7 INCHES
THROUGH SUNDAY NIGHT AND A WINTER STORM WATCH WILL BE ISSUED FOR
SUNDAY AFTERNOON AND SUNDAY NIGHT ACROSS PORTIONS OF CENTRAL KS.
THE SYSTEM IS EXPECTED TO LIFT FAIRLY RAPIDLY NORTH AND EAST AWAY
FROM THE AREA ON MONDAY WITH CLEARING SKIES AND RISING TEMPERATURES
ANTICIPATED BY AFTERNOON.
.LONG TERM...(TUESDAY THROUGH FRIDAY)
ISSUED AT 220 AM CST SAT DEC 12 2015
ANOTHER FAST MOVING STORM SYSTEM WILL IMPACT THE CENTRAL ROCKIES
AND NORTHERN PLAINS STATES ON TUESDAY. BREEZY WESTERLY WINDS AND
PERHAPS AN ISOLATED SHOWER OR SNOW FLURRY MAY IMPACT PORTIONS OF
CENTRAL KS...ALTHOUGH LARGE-SCALE FORCING FOR SUBSIDENCE ON THE
SOUTHERN PERIPHERY OF THE MID/UPPER TROUGH SHOULD KEEP MUCH OF THE
AREA DRY. A MEAN MID/UPPER TROUGH IS PROGGED TO REMAIN SITUATED
ACROSS THE CENTRAL CONUS THROUGH THE REMAINDER OF THE PERIOD
RESULTING IN MOSTLY DRY WEATHER CONDITIONS AND SEASONABLY COOL
TEMPERATURES..
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 600 AM CST SAT DEC 12 2015
INCREASINGLY MOIST LOW LEVEL FLOW MOVING INTO SURFACE FRONT ALONG
I-35 WILL RESULT IN PERSISTENT MVFR/IFR CONDITIONS FOR MUCH OF THE
PERIOD FOR MOST SITES. FRONT WILL WAFFLE IN THE VICINITY OF KICT
THROUGHOUT MUCH OF THE DAY BEFORE MAKING A SLIGHT DRIFT TO THE
NORTHWEST. PRECIPITATION CHANCES WILL INCREASE TONIGHT DUE TO
COMBO OF INCREASING DIFFLUENCE...APPROACHING UPPER ENERGY ANY
DEEPER MOISTURE. MARGINAL INSTABILITY WILL RESULT IN A FEW
EMBEDDED THUNDERSTORMS. -HOWERTON
&&
.PRELIMINARY POINT TEMPS/POPS...
WICHITA-KICT 63 47 47 32 / 60 90 80 40
HUTCHINSON 57 43 44 31 / 60 80 80 60
NEWTON 59 46 47 31 / 60 90 80 40
ELDORADO 67 51 51 32 / 50 90 80 30
WINFIELD-KWLD 68 52 52 33 / 50 90 90 30
RUSSELL 49 37 37 28 / 50 70 80 70
GREAT BEND 51 37 37 29 / 50 70 80 70
SALINA 53 43 43 30 / 60 80 80 70
MCPHERSON 55 43 44 30 / 60 80 80 60
COFFEYVILLE 71 60 60 37 / 50 90 90 30
CHANUTE 69 59 59 36 / 50 90 90 30
IOLA 69 59 59 36 / 50 90 90 30
PARSONS-KPPF 70 59 60 37 / 50 90 90 30
&&
.ICT WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY
NIGHT FOR KSZ032-033-047.
&&
$$
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1007 PM CST SUN DEC 13 2015
.UPDATE...
Issued at 1002 PM CST SUN DEC 13 2015
The Wind Advisory for southeast Missouri has been allowed to
expire. The rest of the area remains in the Wind Advisory until 2
AM.
UPDATE Issued at 850 PM CST SUN DEC 13 2015
Have been updating the grids every couple of hours mainly to catch
up to slower than expected advancement of the leading edge of the
rain, and warmer than expected temperatures. Strong
south/southeast winds are actually advecting warmer air northward
across the northern portions of the forecast area. KEVV tied
their record high of 70 at 01Z. Figure that we will get to the
forecast lows behind the front, so most of the changes are just to
the hourly detail mainly through midnight.
The south southeast winds are finally kicking in over the Purchase
Area and up the MS River. Multiple sites including KPAH have
gusted in the 45-50 mph range in the last hour. We are expecting
the strongest winds just ahead of the fine line on radar, with a
lesser, but still gusty south southwest winds behind it.
We did notice a 48kt gust at KHKA in northeast Arkansas as the
fine line move through there. Not much to see on radar, but maybe
a slight decrease in reflectivity as it moved through that area.
Anyway, KNQA radar data indicates that the intensity of the fine
line has weakened, so we are not expecting to see much
enhancement, if any at all, with the line.
We are planning on letting the Missouri segment of the Wind
Advisory expire as scheduled at 04Z, but may have to make a last
minute adjustment to the MS River counties if the fine line has
not quite cleared the state by then.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 126 PM CST SUN DEC 13 2015
First, went ahead with a Wind Advisory for mainly this evening.
The RAP and GFS both show a notable and precise increase in 950mb
winds 50-60 kts, with lapse rates in this layer (even looking up
to 925 mb) on the order of 6-7.5., and interestingly enough right
across the PAH CWFA. This is concern enough to go ahead with an
Advisory. The strongest winds should happen right along and out
ahead of the main band of showers and cold front that will move
across the area. We will see if it comes to fruition. If nothing
else it should come close.
Otherwise categorical Pops for showers tonight. No change with
respect to thunder. Will be leaving it out given the all but zero
chance. PoPs will be on the decrease after midnight west 1/2 of
the area. Monday, wrap around chance of light showers will be
maintained mainly for the north 2/3 of the area. Chances should
shift off to the northeast by early afternoon, with dry and cooler
weather forecast right on through Tuesday. We maintained the
chance of showers developing across the area Tuesday night, mainly
after midnight. Temps geared more toward raw model output given
the active pattern. Some incorporation of MOS was used.
.LONG TERM...(Wednesday through Sunday)
Issued at 230 PM CST SUN DEC 13 2015
A cold front will be moving across the PAH forecast area through the
day Wednesday. Models continue to generate some light QPF with its
passage, with ECMWF be a bit more generous than the GFS and
Canadian. Will continue with slight to low chance pops for showers
across the entire area on Wednesday, with chances confined to just
our far eastern counties Wednesday night.
Wednesday will be our last mild day for the week, with high
temperatures reaching the upper 50s west and northwest to the lower
60s southeast. Winds will shift to the west to northwest behind the
cold front Wednesday night into Thursday, which will bring in more
seasonal air to our region, especially for Friday and into the early
part of the weekend. Our chilliest day will be Saturday when
temperatures will be a couple of degrees below seasonal normals.
Surface high pressure will move over our area Saturday night, and
with clear skies and near calm winds, this should our coldest night
of the forecast period with lows mostly in the middle 20s. The high
will move east of our region by Sunday, which will shift winds back
to the south. This will help temperatures rebound to near seasonal
readings.
&&
.AVIATION...
Issued at 1111 AM CST SUN DEC 13 2015
Light rain showers continued west of a line from KMVN to KSIK.
Little eastward progression is expected this afternoon with some
dissipation expected as well. Otherwise generally VFR lower cigs
with some MVFR at times in and near the precip region. Gusty SSE
winds up to 20 kts as well. We will see the winds pick up later
this afternoon and continue through the evening. Some gusts 30-35
kts likely from the SSE, at least until the main band of showers
arrives tonight. The main push of showers will be starting 03z
KCGI...04-06z east toward KPAH/KEVV/KOWB, with ending times from
09-11z. Mostly MVFR vsbys with the showers. Gusty SSW winds
expected in the wake of the precip with mainly MVFR cigs
persisting, and isolated light showers possible.
&&
.PAH Watches/Warnings/Advisories...
IL...Wind Advisory until 2 AM CST Monday for ILZ075>078-080>094.
MO...NONE.
IN...Wind Advisory until 2 AM CST Monday for INZ081-082-085>088.
KY...Wind Advisory until 2 AM CST Monday for KYZ001>022.
&&
$$
UPDATE...DRS
SHORT TERM...CN
LONG TERM...RST
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
850 PM CST SUN DEC 13 2015
.UPDATE...
Issued at 850 PM CST SUN DEC 13 2015
Have been updating the grids every couple of hours mainly to catch
up to slower than expected advancement of the leading edge of the
rain, and warmer than expected temperatures. Strong
south/southeast winds are actually advecting warmer air northward
across the northern portions of the forecast area. KEVV tied
their record high of 70 at 01Z. Figure that we will get to the
forecast lows behind the front, so most of the changes are just to
the hourly detail mainly through midnight.
The south southeast winds are finally kicking in over the Purchase
Area and up the MS River. Multiple sites including KPAH have
gusted in the 45-50 mph range in the last hour. We are expecting
the strongest winds just ahead of the fine line on radar, with a
lesser, but still gusty south southwest winds behind it.
We did notice a 48kt gust at KHKA in northeast Arkansas as the
fine line move through there. Not much to see on radar, but maybe
a slight decrease in reflectivity as it moved through that area.
Anyway, KNQA radar data indicates that the intensity of the fine
line has weakened, so we are not expecting to see much
enhancement, if any at all, with the line.
We are planning on letting the Missouri segment of the Wind
Advisory expire as scheduled at 04Z, but may have to make a last
minute adjustment to the MS River counties if the fine line has
not quite cleared the state by then.
&&
.SHORT TERM...(This evening through Tuesday night)
Issued at 126 PM CST SUN DEC 13 2015
First, went ahead with a Wind Advisory for mainly this evening.
The RAP and GFS both show a notable and precise increase in 950mb
winds 50-60 kts, with lapse rates in this layer (even looking up
to 925 mb) on the order of 6-7.5., and interestingly enough right
across the PAH CWFA. This is concern enough to go ahead with an
Advisory. The strongest winds should happen right along and out
ahead of the main band of showers and cold front that will move
across the area. We will see if it comes to fruition. If nothing
else it should come close.
Otherwise categorical Pops for showers tonight. No change with
respect to thunder. Will be leaving it out given the all but zero
chance. PoPs will be on the decrease after midnight west 1/2 of
the area. Monday, wrap around chance of light showers will be
maintained mainly for the north 2/3 of the area. Chances should
shift off to the northeast by early afternoon, with dry and cooler
weather forecast right on through Tuesday. We maintained the
chance of showers developing across the area Tuesday night, mainly
after midnight. Temps geared more toward raw model output given
the active pattern. Some incorporation of MOS was used.
.LONG TERM...(Wednesday through Sunday)
Issued at 230 PM CST SUN DEC 13 2015
A cold front will be moving across the PAH forecast area through the
day Wednesday. Models continue to generate some light QPF with its
passage, with ECMWF be a bit more generous than the GFS and
Canadian. Will continue with slight to low chance pops for showers
across the entire area on Wednesday, with chances confined to just
our far eastern counties Wednesday night.
Wednesday will be our last mild day for the week, with high
temperatures reaching the upper 50s west and northwest to the lower
60s southeast. Winds will shift to the west to northwest behind the
cold front Wednesday night into Thursday, which will bring in more
seasonal air to our region, especially for Friday and into the early
part of the weekend. Our chilliest day will be Saturday when
temperatures will be a couple of degrees below seasonal normals.
Surface high pressure will move over our area Saturday night, and
with clear skies and near calm winds, this should our coldest night
of the forecast period with lows mostly in the middle 20s. The high
will move east of our region by Sunday, which will shift winds back
to the south. This will help temperatures rebound to near seasonal
readings.
&&
.AVIATION...
Issued at 1111 AM CST SUN DEC 13 2015
Light rain showers continued west of a line from KMVN to KSIK.
Little eastward progression is expected this afternoon with some
dissipation expected as well. Otherwise generally VFR lower cigs
with some MVFR at times in and near the precip region. Gusty SSE
winds up to 20 kts as well. We will see the winds pick up later
this afternoon and continue through the evening. Some gusts 30-35
kts likely from the SSE, at least until the main band of showers
arrives tonight. The main push of showers will be starting 03z
KCGI...04-06z east toward KPAH/KEVV/KOWB, with ending times from
09-11z. Mostly MVFR vsbys with the showers. Gusty SSW winds
expected in the wake of the precip with mainly MVFR cigs
persisting, and isolated light showers possible.
&&
.PAH Watches/Warnings/Advisories...
IL...Wind Advisory until 2 AM CST Monday for ILZ075>078-080>094.
MO...Wind Advisory until 10 PM CST this evening for MOZ076-086-087-
100-107>112-114.
IN...Wind Advisory until 2 AM CST Monday for INZ081-082-085>088.
KY...Wind Advisory until 2 AM CST Monday for KYZ001>022.
&&
$$
UPDATE...DRS
SHORT TERM...CN
LONG TERM...RST
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1255 PM CST SAT DEC 12 2015
.AVIATION...
FOR 12/18Z TAFS...AMPLE MIXING HAS ALLOWED FOR VFR CIGS ACROSS
MOST OF THE REGION. HOWEVER...THIS WILL ONLY LAST UNTIL THE
AFTERNOON HOURS...AS SHOWERS AND THUNDERSTORMS WILL MOVE INTO TO OUR E TX
TERMINALS BY LATE THIS AFTERNOON AND SLOWLY SPREAD EWD DURING THE
LATE EVENING AND OVERNIGHT PERIODS AS AN APPROACHING STORM SYSTEM
MOVES THROUGH THE REGION. SLY WINDS TODAY WILL INCREASE IN SPEED
TO 10-15 KTS WITH HIGHER GUSTS AND REMAIN SO THROUGHOUT MUCH OF
THE PD. /20/
&&
.PREV DISCUSSION... /ISSUED 1148 AM CST SAT DEC 12 2015/
DISCUSSION...
THE STRATUS SHIELD LINGERS ACROSS THE REGION AS OF LATE
MORNING...ALTHOUGH SOME BREAKS HAVE BEEN NOTED ON THE VISIBLE
SATELLITE IMAGERY OVER PORTIONS OF CNTRL AND ERN LA/WRN MS. THIS
STRATUS SHIELD MAY PERSIST THROUGH MUCH OF THE DAY /WITH SOME
SCATTERING POSSIBLE OVER THE ERN ZONES/ AS LOW LEVEL MOISTURE
CONTINUES TO DEEPEN BENEATH THE LOW LEVEL CAPPING INVERSION NOTED
ON THE 12Z KSHV RAOB. THE CIRRUS SHIELD WILL ONLY DEEPEN WITH TIME
AS WELL...AS THE SUBTROPICAL JET SHIFTS FARTHER E ACROSS THE LOWER
MS VALLEY AHEAD OF THE LONGWAVE TROUGH OVER THE DESERT SW. DESPITE
THE CLOUD COVER...SHOULD STILL SEE NEAR RECORD MAX TEMPS THIS
AFTERNOON AS TEMPS APPROACH 80 DEGREES ESPECIALLY OVER N
LA/ADJACENT SECTIONS OF EXTREME ERN TX. HAVE HAD TO RAISE MAX
TEMPS THIS AFTERNOON 1-2 DEGREES GIVEN THE 16-17Z OBS...BUT THE
LACK OF SUN SHOULD TAPER THE DIURNAL SWING IN TEMPS FROM THE WARM
START TO THE MORNING.
MOSAIC RADAR IMAGERY INDICATES AN INCREASING AREAS OF CONVECTION
RAPIDLY DEVELOPING THIS MORNING OVER THE TX HILL COUNTRY...WITH
MORE SCATTERED DEVELOPMENT ONGOING ACROSS SE TX...WHICH WILL
SPREAD NNE INTO PORTIONS OF E TX THIS AFTERNOON IN ASSOCIATION WITH
A WEAK SHORTWAVE/INCREASED PVA EJECTING NE AHEAD OF THE LONGWAVE
TROUGH OVER THE DESERT SW. THE 12Z PROGS AND THE LATEST HRRR RUNS
HAVE INITIALIZED ON THIS WELL...AFFECTING E TX/EXTREME SE OK BY
MID TO LATE AFTERNOON. HAVE INCREASED POPS BACK TO LIKELY ACROSS
THE WRN SECTIONS OF E TX THIS AFTERNOON IN THE LATE MORNING
UPDATE...TAPERING TO HIGH CHANCE ACROSS THE REMAINDER OF E TX/SE
OK. SLIGHT CHANCE POPS SHOULD WORK FOR MUCH OF SW AR/N LA THIS
AFTERNOON AS THE MOISTURE WILL BE LATER TO DEEPEN OVER THESE
AREAS. THE CURRENT LAKE WIND ADVISORY THIS AFTERNOON LOOKS GOOD
OVER THE WRN SECTIONS OF E TX AS THE PRESSURE GRADIENT HAS
TIGHTENED OVER THE SRN PLAINS AHEAD OF DEEPENING SFC LOW PRESSURE
OVER ERN NM. WILL LIKELY HAVE TO EXPAND THE LAKE WIND ADV. FOR
TONIGHT WITH THE AFTERNOON FORECAST PACKAGE AS THE TIGHT PRESSURE
GRADIENT EXPANDS FARTHER E OVER THE REGION.
WILL ALSO RE-ASSESS THE SVR POTENTIAL IN THE AFTERNOON DISCUSSION
AS WELL...ALTHOUGH HAVE HIGHER CONFIDENCE THAT THIS SYSTEM WILL
BE PRIMARILY A HEAVY RAINFALL/FLASH FLOOD THREAT.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 80 65 66 45 / 20 90 100 20
MLU 81 68 72 47 / 10 40 100 30
DEQ 76 60 61 40 / 30 100 80 20
TXK 78 62 64 43 / 30 100 100 10
ELD 79 67 70 43 / 20 70 100 30
TYR 78 56 58 43 / 60 100 80 10
GGG 78 60 62 43 / 50 100 80 10
LFK 79 63 64 43 / 50 100 80 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR ARZ050-051-059-060-070-071.
LA...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR LAZ001-002-010.
OK...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR OKZ077.
TX...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR TXZ096-097-108>112-124>126-136>138-149>153-165-
166.
LAKE WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR TXZ096-
108>110-124-125-136-137-149-150.
&&
$$
20
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
1148 AM CST SAT DEC 12 2015
.DISCUSSION...
THE STRATUS SHIELD LINGERS ACROSS THE REGION AS OF LATE
MORNING...ALTHOUGH SOME BREAKS HAVE BEEN NOTED ON THE VISIBLE
SATELLITE IMAGERY OVER PORTIONS OF CNTRL AND ERN LA/WRN MS. THIS
STRATUS SHIELD MAY PERSIST THROUGH MUCH OF THE DAY /WITH SOME
SCATTERING POSSIBLE OVER THE ERN ZONES/ AS LOW LEVEL MOISTURE
CONTINUES TO DEEPEN BENEATH THE LOW LEVEL CAPPING INVERSION NOTED
ON THE 12Z KSHV RAOB. THE CIRRUS SHIELD WILL ONLY DEEPEN WITH TIME
AS WELL...AS THE SUBTROPICAL JET SHIFTS FARTHER E ACROSS THE LOWER
MS VALLEY AHEAD OF THE LONGWAVE TROUGH OVER THE DESERT SW. DESPITE
THE CLOUD COVER...SHOULD STILL SEE NEAR RECORD MAX TEMPS THIS
AFTERNOON AS TEMPS APPROACH 80 DEGREES ESPECIALLY OVER N
LA/ADJACENT SECTIONS OF EXTREME ERN TX. HAVE HAD TO RAISE MAX
TEMPS THIS AFTERNOON 1-2 DEGREES GIVEN THE 16-17Z OBS...BUT THE
LACK OF SUN SHOULD TAPER THE DIURNAL SWING IN TEMPS FROM THE WARM
START TO THE MORNING.
MOSAIC RADAR IMAGERY INDICATES AN INCREASING AREAS OF CONVECTION
RAPIDLY DEVELOPING THIS MORNING OVER THE TX HILL COUNTRY...WITH
MORE SCATTERED DEVELOPMENT ONGOING ACROSS SE TX...WHICH WILL
SPREAD NNE INTO PORTIONS OF E TX THIS AFTERNOON IN ASSOCIATION WITH
A WEAK SHORTWAVE/INCREASED PVA EJECTING NE AHEAD OF THE LONGWAVE
TROUGH OVER THE DESERT SW. THE 12Z PROGS AND THE LATEST HRRR RUNS
HAVE INITIALIZED ON THIS WELL...AFFECTING E TX/EXTREME SE OK BY
MID TO LATE AFTERNOON. HAVE INCREASED POPS BACK TO LIKELY ACROSS
THE WRN SECTIONS OF E TX THIS AFTERNOON IN THE LATE MORNING
UPDATE...TAPERING TO HIGH CHANCE ACROSS THE REMAINDER OF E TX/SE
OK. SLIGHT CHANCE POPS SHOULD WORK FOR MUCH OF SW AR/N LA THIS
AFTERNOON AS THE MOISTURE WILL BE LATER TO DEEPEN OVER THESE
AREAS. THE CURRENT LAKE WIND ADVISORY THIS AFTERNOON LOOKS GOOD
OVER THE WRN SECTIONS OF E TX AS THE PRESSURE GRADIENT HAS
TIGHTENED OVER THE SRN PLAINS AHEAD OF DEEPENING SFC LOW PRESSURE
OVER ERN NM. WILL LIKELY HAVE TO EXPAND THE LAKE WIND ADV. FOR
TONIGHT WITH THE AFTERNOON FORECAST PACKAGE AS THE TIGHT PRESSURE
GRADIENT EXPANDS FARTHER E OVER THE REGION.
WILL ALSO RE-ASSESS THE SVR POTENTIAL IN THE AFTERNOON DISCUSSION
AS WELL...ALTHOUGH HAVE HIGHER CONFIDENCE THAT THIS SYSTEM WILL
BE PRIMARILY A HEAVY RAINFALL/FLASH FLOOD THREAT.
ZONE UPDATE ALREADY OUT...GRIDS WILL BE AVAILABLE SHORTLY.
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 80 65 66 45 / 20 90 100 20
MLU 81 68 72 47 / 10 40 100 30
DEQ 76 60 61 40 / 30 100 80 20
TXK 78 62 64 43 / 30 100 100 10
ELD 79 67 70 43 / 20 70 100 30
TYR 78 56 58 43 / 60 100 80 10
GGG 78 60 62 43 / 50 100 80 10
LFK 79 63 64 43 / 50 100 80 10
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR ARZ050-051-059-060-070-071.
LA...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR LAZ001-002-010.
OK...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR OKZ077.
TX...FLASH FLOOD WATCH FROM 6 PM CST THIS EVENING THROUGH SUNDAY
MORNING FOR TXZ096-097-108>112-124>126-136>138-149>153-165-
166.
LAKE WIND ADVISORY UNTIL 6 PM CST THIS EVENING FOR TXZ096-
108>110-124-125-136-137-149-150.
&&
$$
15
AREA FORECAST DISCUSSION
NWS CARIBOU ME
919 PM EST SUN DEC 13 2015
.SYNOPSIS...
A WINTRY MIX OF PRECIPITATION CAN BE EXPECTED LATE TONIGHT
THROUGH TUESDAY AS LOW PRESSURE APPROACHES FROM THE WEST.
&&
.NEAR TERM /THROUGH MONDAY/...
919 PM UPDATE...HIGH PRES CONTINUES TO NOSE DOWN INTO THE PINE
TREE STATE FROM THE NORTH THIS EVENING. HIGH CLOUDS MOVING ACROSS
THE CWA ATTM WITH MID CLOUDS TO FOLLOW SHORTLY. OVERRUNNING
PRECIPITATION WILL DEVELOP FROM THE WEST AFTER MIDNIGHT. CLOSEST
REPORT OF PRECIPITATION AT 02Z IS -RA AT BERLIN, NH. LATEST RUNS
AND TRENDS OF THE RAP AND HRRR WOULD KEEP THE MAJORITY OF THE
PRECIPITATION NORTH OF THE COAST OVERNIGHT. THE HRRR HAS A BETTER
HANDLE ON THE AREAL EXTENT OF THE PRECIPITATION COMPARED TO THE
RAP13 AS OF 02Z. THE 00Z KCAR SOUNDING HAD A DEEP DRY LAYER FROM
AROUND 900-550H THAT WILL TAKE SOME TIME TO MOISTEN UP. STILL
LOOKS LIKE THE PRECIPITATION WILL START AS PREDOMINATELY -SN FROM
BAXTER STATE PARK NORTH WITH A MIX OF SNOW, SLEET, AND FREEZING
RAIN TO THE SOUTH. NO MAJOR CHANGE TO THE ONGOING FORECAST ATTM,
BUT A FEW MINOR TWEAKS BASED ON THE 9 PM OBSERVATIONS AND THE
LATEST RADAR AND NEAR TERM MODEL TRENDS.
PREVIOUS DISCUSSION... MAINLY CLEAR SKIES THIS EVENING WILL GIVE
WAY TO INCREASING CLOUDS OVERNIGHT IN ADVANCE OF AN APPROACHING
WARM FRONT TO THE SOUTH. THE COMBINATION OF CLEAR SKIES AND LIGHT
WINDS WILL ALLOW TEMPERATURES TO FALL QUICKLY EARLY THIS EVENING
BEFORE CLOUDS INCREASE LATER TONIGHT. PRECIPITATION IS EXPECTED TO
DEVELOP FROM WEST TO EAST AFTER MIDNIGHT IN THE FORM OF A WINTRY
MIX ACROSS THE CENTRAL HIGHLANDS AND SOUTHERN AROOSTOOK AND MAINLY
IN THE FORM OF SNOW ACROSS FAR NORTHERN MAINE AND THE ST JOHN
VALLEY. ACROSS DOWN EAST MAINE THERE MAY BE A PERIOD OF LIGHT
FREEZING RAIN AFTER MIDNIGHT AND CONTINUING INTO MONDAY MORNING.
ACROSS COASTAL DOWN EAST,THE PRECIPITATION MAY START AS A BRIEF
MIX OF LIGHT FREEZING RAIN BUT QUICKLY CHANGE TO PLAIN RAIN FIRST
THING MONDAYS MORNING. LOWS TONIGHT WILL RANGE FROM THE LOW TO MID
20S ACROSS THE NORTH AND UPPER 20S TO NEAR 30 DOWNEAST.
MONDAY IS SHAPING UP AS A CLOUDY DAY WITH A LIGHT WINTRY
MIX EXPECTED ACROSS NORTHERN AND CENTRAL AREAS AND MAINLY PLAIN
RAIN DOWNEAST. THE WINTRY MIX WILL CONTINUE ACROSS NORTHERN AREAS
THROUGH MONDAY, WITH RAIN TAPERING TO A LIGHT DRIZZLE DURING
MONDAY AFTERNOON. HIGHS ON MONDAY WILL ONLY RANGE FROM THE UPPER
20S TO NEAR 30 NORTH AND MID TO UPPER 30S DOWNEAST.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
H5 LOW WL BE IN THE CNTRL GREAT LKS BY THE START OF THE SHORT TERM.
SFC LOW LOCATED IN THE SAME GENERAL AREA WL ALLOW A WMFNT TO BE
PULLED INTO NEW ENGLAND BY 00Z TUE. OVERRUNNING WL CONTINUE BUT
MOISTURE WL ONLY RMN ACRS THE FAR NORTH DRG THE EARLY EVNG HRS ON
TUE. EXPECT A DRY MID-LVL WEDGE TO MV INTO MOST OF CWA THRU ABOUT
MIDNIGHT BFR SLOWLY STARTING TO SATURATE AS LOPRES CREEPS CLOSER TO
THE STATE. THUS HV ALLOWED FOR A PD OF DRIZZLE BTWN 00Z AND 03Z OVR
THE BANGOR REGION AND DOWNEAST WITH AREAS OF FRZG DRIZZLE FURTHER TO
THE NORTH WITH THE EXCEPTION OF NRN AROOSTOOK.
FOR THE NIGHTTIME HRS EXPECT MAINLY RAIN SOUTH OF A GREENVILLE TO
DANFORTH LINE AS WARM AIR SURGES NORTHWARD. TEMPS ALOFT BEGIN TO
WARM NORTH OF THIS LINE BY THE START OF THE PD ALLOWING SLEET AND
EVENTUALLY FREEZING RAIN TO MV IN DRG THE OVRNGT. TEMPS ARND 800MB
DO NOT APPEAR TO GET ANY WARMER THAN ABOUT 4C WITH SFC TEMPS STUCK
BLO FRZG THRU 12Z TUE.
ALL 12Z MODELS SHOW LOW TRANSFERRING ITS ENERGY INTO THE GULF OF
MAINE BY 12Z TUE. AS THE SFC LOW DVLPS EXPECT MOISTURE TO INCRS FM
THE WEST AS FRONT OCCLUDES BTWN LOWS AFT 06Z. CLDR AIR WORKS IN ACRS
THE NORTH BY 18Z TUE AS LOPRES INTENSIFIES OVR THE BAY OF FUNDY. NRN
AROOSTOOK WL LKLY SEE SNOW TUE AFTN AS BLYR COOLS BLO FRZG. SNOW WL
LKLY FALL HVY AT TIMES LATE TUE AFTN AND WED EVNG.
IT APPEARS THAT THE BEST CHC FOR ACCUMULATING SNOW THROUGHOUT THE
ENTIRE PD WL BE TUE AFTN ACRS NW AND NE AROOSTOOK. DRG THIS PD OF
TIME 4-6 INCHES OF SNOW MAY FALL WITH AMNTS TAPERING DRASTICALLY
FURTHER TO THE SOUTH. THIS SNOW WL LKLY FALL ON FREEZING RAIN THAT
IS ABLE TO ACCRETE EARLIER THUS HV OPTED TO ISSUE A WINTER STORM
WRNG FOR THESE AREAS EVEN THO CRITERIA WL NOT TECHNICALLY BE MET.
FURTHER TO THE SOUTH WL GO WITH A WINTER WX ADVISORY FOR MINOR
ACCUMS OF SNOW, SLEET AND FZRA.
TEMPS WL LKLY RISE DURING THE NIGHTTIME HRS WITH MIN TEMPS BEING
REACHED ARND MIDNIGHT BFR COMING UP. MAX TEMPS ON TUE WL BE FAIRLY
SIMILAR TO THE LOWS FOR TUE MRNG AS PRECIP AND EXTENSIVE CLD CVR
WL KEEP TEMPS FAIRLY STEADY BFR CLDR AIR IS ABLE TO BE WRAPPED
INTO THE SYSTEM FM THE NORTH.
LOW PULLS OFF TO THE EAST TUE NIGHT WITH STRONG WINDS CONTINUING
THRU THE END OF THE SHORT TERM AS PRESSURE GRADIENT RMNS TIGHT.
HIPRES WL BEGIN TO BUILD IN LATE WED AFTN.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
THE EXTENDED MODELS ARE IN GOOD AGREEMENT AT THE START OF THE
PERIOD. A HIGH PRESSURE RIDGE WILL BE EXTENDED ACROSS ERN CANADA
THROUGH MAINE INTO THE NORTH ATLANTIC. A MATURE LOW PRESSURE
SYSTEM OVER WRN LAKE SUPERIOR/ MN...OCCLUDED FRONT WRAPPED AROUND
THE LOW EXTENDING EAST INTO THE CENTRAL GREAT LAKES REGION. COLD
FRONT EXTENDING SOUTH TO THE GULF OF MEXICO. THE GFS AND ECMWF
SHOW A DIFFERENCE IN TIMING OF THE MOVEMENT OF THE COLD FRONT. BY
THURS MRNG THE GFS MOVES IT EAST TO ERN QUEBEC ALONG THE WRN MAINE
BORDER. THE ECMWF MOVES EAST TO THE ERN GREAT LAKES. BOTH MODELS
SHOW A SECONDARY LOW MOVING NORTH ALONG THE COLD FRONT. GFS OVR
ERN VA...ECMWF OVER ERN SC. THE DIFFERENCES CONTINUE...BY THURS
EVNG THE GFS HAS THE COLD FRONT EXTENDING FROM ERN QUEBEC...SW
THROUGH MAINE...INTO SRN NEW ENGLAND. THE SECONDARY LOW ALONG THE
COAST OF NJ. THE ECMWF MOVES THE COLD FRONT TO ME/NH...THE
SECONDARY LOW TO NJ. BY FRI MRNG THE GFS MOVES THE FRONT EAST OF
MAINE...THE 2ND LOW TO SE GULF OF MAINE. THE ECMWF HOLDS THE COLD
FRONT OVER ME...WITH THE 2ND LOW MOVING INTO THE WRN GULF OF MAINE
SOUTH OF PORTLAND. FRI EVNG THE GFS HAS WRAP AROUND ASSOCIATED
WITH THE UPPER LOW TRACKING THROUGH ME. THIS WILL CONTINUE THROUGH
SUN MRNG. THE ECMWF MAINTAINS A WEAK RIDGE ACROSS THE AREA TIL SAT
EVNG...THEN MOVES THE WRAP AROUND INTO NRN ME THROUGH SUN EVNG.
THE GFS SHOWS A NEW WARM FRONTAL SYSTEM MOVING INTO WRN MAINE FOR
THE END OF THE PERIOD. THE ECMWF CONTINUES TO TRAIL BY ABOUT 12
HRS.
LOADED A BLEND TO SMOOTH OUT DIFFERENCES IN THE MODELS THROUGH
THE PERIOD. LOADED NAWAVE4 FOR SEAS...USED WIND GUSTS FROM FACTOR
TOOL FOR GUSTS.
&&
.AVIATION /02Z MONDAY THROUGH FRIDAY/...
NEAR TERM: VFR CONDITIONS CAN BE EXPECTED THROUGH MIDNIGHT.
CONDITIONS WILL THEN BEGIN TO DETERIORATE TO MVFR AT ALL SITES
TOWARD MORNING WITH THE ONSET OF PRECIPITATION. MVFR/IFR
CONDITIONS ARE EXPECTED DUE TO CIGS AND REDUCED VISIBILITY IN
PRECIPITATION ON MONDAY.
SHORT TERM: MVFR/IFR EXPECTED THROUGH TUE NIGHT AS LOW PRESSURE
SYSTEM SPREADS WINTRY PRECIP INTO TERMINALS. VFR EXPECTED WED/WED
NIGHT BEFORE BEING REDUCED TO MVFR AHEAD OF NEXT SYSTEM.
&&
.MARINE...
NEAR TERM: WINDS/SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT
ADVISORY LEVELS THROUGH MONDAY.
SHORT TERM: SEAS WL INCREASE TO ABOVE SCA LEVELS MONDAY NIGHT IN
SERLY SWELLS THROUGH TUE AFTERNOON. TIGHT PRESSURE GRADIENT
FOLLOWING DEPARTING LOW WL KEEP WAVES UP ABOVE 5FT THRU WED
MORNING. GALE FORCE WINDS MAY BE POSSIBLE BEGINNING LATE MON NIGHT
THROUGH WED MORNING.
&&
.CLIMATE...
MONTH TO DATE IT HAS BEEN THE 7TH WARMEST DECEMBER AT CARIBOU AND
THE 10TH WARMEST AT BANGOR.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WINTER STORM WARNING FROM 4 AM MONDAY TO 7 PM EST TUESDAY FOR
MEZ001-002.
WINTER WEATHER ADVISORY FROM 4 AM MONDAY TO 7 PM EST TUESDAY
FOR MEZ003>006-010.
WINTER WEATHER ADVISORY FROM 4 AM TO 1 PM EST MONDAY FOR
MEZ011-015>017-031-032.
MARINE...NONE.
&&
$$
NEAR TERM...CB/DUDA
SHORT TERM...FARRAR
LONG TERM...NORTON
AVIATION...CB/DUDA/FARRAR
MARINE...CB/DUDA/FARRAR
CLIMATE...CB
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
421 AM EST SAT DEC 12 2015
.SYNOPSIS...
WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
WEEKEND...WITH THE CHANCE FOR A PASSING SHOWER TODAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A WARM FRONT WILL GLIDE THROUGH THE REGION THIS MORNING...OPENING
THE DOOR FOR STRONG WARM AIR ADVECTION. LIMITED UPPER LEVEL
SUPPORT WILL KEEP SHOWER CHANCES LOW AND HAVE CONTINUED WITH THE
PREVIOUS IDEA OF SLIGHT CHANCE/LOW CHANCE POPS TODAY. FRONT MOVES
INTO NEW YORK STATE THIS AFTERNOON...AND AN UPPER LEVEL RIDGE WILL
SLOWLY BUILD OVER THE OHIO VALLEY. THIS WILL DECREASE RAIN
CHANCES...SO ANY LINGERING POPS WILL BE HIGHLIGHTED OVER THE
NORTHERN THIRD OF THE AREA. CLOUD COVER WILL BE TRICKY AS MODEL
SOUNDINGS KEEP THE LAYER BELOW 5000FT SATURATED THROUGHOUT THE
DAY. HOWEVER...WITH STRONG WARM AIR ADVECTION...TEMPERATURES WILL
BE WELL ABOVE NORMAL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
WITH THE UPPER LEVEL RIDGE IN CONTROL TONIGHT...AND THE WARM
FRONT WELL NORTH OF THE AREA...HAVE GONE WITH A DRY FORECAST
INCLUDING VERY MILD TEMPERATURES FOR MID DECEMBER. REGION WILL
REMAIN IN THE WARM SECTOR THROUGH SUNDAY NIGHT. THIS WILL KEEP THE
AREA DRY AND EVENTUALLY DECREASE CLOUD COVER FROM SOUTH TO NORTH
ON SUNDAY AFTERNOON. TEMPERATURES SHOULD REACH CLOSE TO 20 TO 25
DEGREES ABOVE NORMAL ON SUNDAY.
MODELS CONTINUE TO SLOW EASTWARD MOVEMENT OF MONDAY`S COLD
FRONT...HOLDING PASSAGE OFF UNTIL LATE MONDAY MORNING/AFTERNOON.
EVEN AT THIS TIME...THERE ARE STILL SOME MINOR DIFFERENCES
BETWEEN MODEL SOLUTIONS ON TIMING...SO FELT A BLEND WAS PRUDENT
WITH THIS FEATURE. GUSTY WINDS ARE POSSIBLE ALONG AND BEHIND THE
FRONT AS A STRONG LOW-LEVEL JET WILL ACCOMPANY THE BOUNDARY.
WOULD THINK THE BEST CHANCE FOR STRONGER GUSTS WOULD ARRIVE LATER
ON MONDAY/MONDAY NIGHT WHEN THE COLD AIR ADVECTION TAKES OVER.
EVEN WITH WIDESPREAD CLOUD COVER AND SHOWERS MONDAY...HIGHS WILL
STILL BE ABOUT 20 DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLD POOL STRATOCU WILL SETTLE IN OVER THE REGION MONDAY NIGHT AND
TUESDAY. TEMPERATURES WILL BEGIN TO WORK THEIR WAY BACK TO NORMAL
LEVELS. THE NEXT SYSTEM WILL SWING THROUGH THE AREA THURSDAY.
MODELS HAVE NOT YET COME TO AN AGREEMENT ON TIMING AND HOW MUCH
PRECIPITATION WILL ACCOMPANY THE BOUNDARY. WILL USE A BLEND OF
MODEL SOLUTIONS FOR MOST OF THE LONG TERM. DOES APPEAR THAT THE
WEEK WILL END ON A NOTICEABLY COLDER NOTE.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
DETERIORATION TO MVFR CIGS IS ANTICIPATED THIS MRNG WITH PASSAGE
OF A WARM FRONT...BUT VFR IS ANTICIPATED BY AFTERNOON AS AREA
TERMINALS SHOULD BE WELL WITHIN THE WARM SECTOR. LATEST NAM AND
GFS SOLNS ARE NOT AS PESSIMISSTIC AS PREVIOUS AND WILL FOLLOW
THAT TREND WITH HRRR LOW CLD COVER AS LGT SFC WIND VEERS TO THE S
AND SSW TWD MIDDAY.
.OUTLOOK...SUNDAY THROUGH WEDNESDAY/...
THE NXT CHC FOR GENL RESTRICTIONS IS EXPECTED WITH THE APCH AND
PASSAGE OF A MONDAY CDFNT.
&&
.CLIMATE...
RECORD HIGHS FOR PITTSBURGH
DECEMBER 12TH 65 IN 2007
DECEMBER 13TH 71 IN 1901
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS PITTSBURGH PA
1233 AM EST SAT DEC 12 2015
.SYNOPSIS...
WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
WEEKEND...WITH THE CHANCE FOR A PASSING SHOWER TODAY.
&&
.NEAR TERM /THROUGH TODAY/...
MINOR ADJUSTMENTS TO OVERNIGHT POPS AND TEMPERATURES. REST OF THE
FORECAST IN GOOD SHAPE.
A WARM FRONT WILL GLIDE THROUGH THE REGION THIS MORNING...OPENING
THE DOOR FOR STRONG WARM AIR ADVECTION. LIMITED UPPER LEVEL
SUPPORT WILL KEEP SHOWER CHANCES LOW AND HAVE CONTINUED WITH THE
PREVIOUS IDEA OF SLIGHT CHANCE/LOW CHANCE POPS TODAY. FRONT MOVES
INTO NEW YORK STATE THIS AFTERNOON...AND AN UPPER LEVEL RIDGE WILL
SLOWLY BUILD OVER THE OHIO VALLEY. THIS WILL DECREASE RAIN
CHANCES...SO ANY LINGERING POPS WILL BE HIGHLIGHTED OVER THE
NORTHERN THIRD OF THE AREA. CLOUD COVER WILL BE TRICKY AS MODEL
SOUNDINGS KEEP THE LAYER BELOW 5000FT SATURATED THROUGHOUT THE
DAY. HOWEVER...WITH STRONG WARM AIR ADVECTION...TEMPERATURES WILL
BE WELL ABOVE NORMAL.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
WITH THE UPPER LEVEL RIDGE IN CONTROL TONIGHT...AND WARM FRONT
WELL NORTH OF THE AREA...HAVE GONE WITH A DRY FORECAST WITH VERY
MILD TEMPERATURES FOR MID DECEMBER. REGION WILL REMAIN IN THE WARM
SECTOR THROUGH SUNDAY NIGHT. THIS WILL KEEP THE AREA DRY AND
EVENTUALLY DECREASE CLOUD COVER FROM SOUTH TO NORTH ON SUNDAY
AFTERNOON. TEMPERATURES SHOULD REACH CLOSE TO 20 TO 25 DEGREES
ABOVE NORMAL ON SUNDAY.
MODELS CONTINUE TO SLOW EASTWARD MOVEMENT OF MONDAY`S COLD
FRONT...HOLDING PASSAGE OFF UNTIL LATE MONDAY MORNING/AFTERNOON.
EVEN AT THIS TIME...THERE ARE STILL SOME MINOR DIFFERENCES
BETWEEN MODEL SOLUTIONS ON TIMING...SO FELT A BLEND WAS PRUDENT
WITH THIS FEATURE. GUSTY WINDS ARE POSSIBLE ALONG AND BEHIND THE
FRONT AS A STRONG LOW-LEVEL JET WILL ACCOMPANY THE BOUNDARY.
WOULD THINK THE BEST CHANCE FOR STRONGER GUSTS WOULD ARRIVE LATER
ON MONDAY WHEN THE COLD AIR ADVECTION TAKES OVER. EVEN WITH
WIDESPREAD CLOUD COVER AND SHOWERS MONDAY...HIGHS WILL STILL BE
ABOUT 20 DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLD POOL STRATOCU WILL SETTLE IN OVER THE REGION MONDAY NIGHT AND
TUESDAY. TEMPERATURES WILL BEGIN TO WORK THEIR WAY BACK TO NORMAL
LEVELS. THE NEXT SYSTEM WILL SWING THROUGH THE AREA THURSDAY.
MODELS HAVE NOT YET COME TO AN AGREEMENT ON TIMING AND HOW MUCH
PRECIPITATION WILL ACCOMPANY THE BOUNDARY. WILL USE A BLEND OF
MODEL SOLUTIONS FOR MOST OF THE LONG TERM. DOES APPEAR THAT THE
WEEK WILL END ON A NOTICEABLY COLDER NOTE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
DETERIORATION TO MVFR CIGS IS ANTICIPATED THIS MRNG WITH PASSAGE
OF A WARM FRONT...BUT VFR IS ANTICIPATED BY AFTERNOON AS AREA
TERMINALS SHOULD BE WELL WITHIN THE WARM SECTOR. LATEST NAM AND
GFS SOLNS ARE NOT AS PESSIMISSTIC AS PREVIOUS AND WILL FOLLOW
THAT TREND WITH HRRR LOW CLD COVER AS LGT SFC WIND VEERS TO THE S
AND SSW TWD MIDDAY.
.OUTLOOK...SUNDAY THROUGH WEDNESDAY/...
THE NXT CHC FOR GENL RESTRICTIONS IS EXPECTED WITH THE APCH AND
PASSAGE OF A MONDAY CDFNT.
&&
.CLIMATE...
RECORD HIGHS FOR PITTSBURGH
DECEMBER 12TH 65 IN 2007
DECEMBER 13TH 71 IN 1901
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1141 PM EST FRI DEC 11 2015
.SYNOPSIS...
WELL ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH THE
WEEKEND...WITH THE CHANCE FOR A PASSING SHOWER TODAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
MINOR ADJUSTMENTS TO OVERNIGHT POPS AND TEMPERATURES. REST OF THE
FORECAST IN GOOD SHAPE.
A WARM FRONT WILL GLIDE THROUGH THE REGION THIS MORNING...OPENING
THE DOOR FOR STRONG WARM AIR ADVECTION. LIMITED UPPER LEVEL
SUPPORT WILL KEEP SHOWER CHANCES LOW AND HAVE CONTINUED WITH THE
PREVIOUS IDEA OF SLIGHT CHANCE/LOW CHANCE POPS TODAY. FRONT MOVES
INTO NEW YORK STATE THIS AFTERNOON...AND AN UPPER LEVEL RIDGE WILL
SLOWLY BUILD OVER THE OHIO VALLEY. THIS WILL DECREASE RAIN
CHANCES...SO ANY LINGERING POPS WILL BE HIGHLIGHTED OVER THE
NORTHERN THIRD OF THE AREA. CLOUD COVER WILL BE TRICKY AS MODEL
SOUNDINGS KEEP THE LAYER BELOW 5000FT SATURATED THROUGHOUT THE
DAY. HOWEVER...WITH STRONG WARM AIR ADVECTION...TEMPERATURES WILL
BE WELL ABOVE NORMAL.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
WITH THE UPPER LEVEL RIDGE IN CONTROL TONIGHT...AND WARM FRONT
WELL NORTH OF THE AREA...HAVE GONE WITH A DRY FORECAST WITH VERY
MILD TEMPERATURES FOR MID DECEMBER. REGION WILL REMAIN IN THE WARM
SECTOR THROUGH SUNDAY NIGHT. THIS WILL KEEP THE AREA DRY AND
EVENTUALLY DECREASE CLOUD COVER FROM SOUTH TO NORTH ON SUNDAY
AFTERNOON. TEMPERATURES SHOULD REACH CLOSE TO 20 TO 25 DEGREES
ABOVE NORMAL ON SUNDAY.
MODELS CONTINUE TO SLOW EASTWARD MOVEMENT OF MONDAY`S COLD
FRONT...HOLDING PASSAGE OFF UNTIL LATE MONDAY MORNING/AFTERNOON.
EVEN AT THIS TIME...THERE ARE STILL SOME MINOR DIFFERENCES
BETWEEN MODEL SOLUTIONS ON TIMING...SO FELT A BLEND WAS PRUDENT
WITH THIS FEATURE. GUSTY WINDS ARE POSSIBLE ALONG AND BEHIND THE
FRONT AS A STRONG LOW-LEVEL JET WILL ACCOMPANY THE BOUNDARY.
WOULD THINK THE BEST CHANCE FOR STRONGER GUSTS WOULD ARRIVE LATER
ON MONDAY WHEN THE COLD AIR ADVECTION TAKES OVER. EVEN WITH
WIDESPREAD CLOUD COVER AND SHOWERS MONDAY...HIGHS WILL STILL BE
ABOUT 20 DEGREES ABOVE NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COLD POOL STRATOCU WILL SETTLE IN OVER THE REGION MONDAY NIGHT AND
TUESDAY. TEMPERATURES WILL BEGIN TO WORK THEIR WAY BACK TO NORMAL
LEVELS. THE NEXT SYSTEM WILL SWING THROUGH THE AREA THURSDAY.
MODELS HAVE NOT YET COME TO AN AGREEMENT ON TIMING AND HOW MUCH
PRECIPITATION WILL ACCOMPANY THE BOUNDARY. WILL USE A BLEND OF
MODEL SOLUTIONS FOR MOST OF THE LONG TERM. DOES APPEAR THAT THE
WEEK WILL END ON A NOTICEABLY COLDER NOTE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
DETERIORATION TO MVFR CIGS IS ANTICIPATED THIS MRNG WITH PASSAGE
OF A WARM FRONT...BUT VFR IS ANTICIPATED BY AFTERNOON AS AREA
TERMINALS SHOULD BE WELL WITHIN THE WARM SECTOR. LATEST NAM AND
GFS SOLNS ARE NOT AS PESSIMISSTIC AS PREVIOUS AND WILL FOLLOW
THAT TREND WITH HRRR LOW CLD COVER AS LGT SFC WIND VEERS TO THE S
AND SSW TWD MIDDAY.
.OUTLOOK...SUNDAY THROUGH WEDNESDAY/...
THE NXT CHC FOR GENL RESTRICTIONS IS EXPECTED WITH THE APCH AND
PASSAGE OF A MONDAY CDFNT.
&&
.CLIMATE...
RECORD HIGHS FOR PITTSBURGH
DECEMBER 12TH 65 IN 2007
DECEMBER 13TH 71 IN 1901
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
15/22
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1224 PM EST SAT DEC 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM EST SAT DEC 12 2015
...QUIET WEATHER TODAY BEFORE SIGNIFICANT RAINFALL SUNDAY INTO
MONDAY...
WEAK E-NE UPSLOPE FLOW CONTINUES...ALLOWING FOR SNOW SHOWERS ALONG
NORTH CENTRAL UPPER MICHIGAN AS WELL AS IN THE KEWEENAW. IT IS
ACTUALLY INTERESTING THAT THE PRECIPITATION IS SNOW RATHER THAN
DRIZZLE/FREEZING DRIZZLE AS IT WOULD SEEM HARD TO IMAGINE MUCH ICE
NUCLEI IN THE SHALLOW /2000 FT/ AND RELATIVELY WARM /-4C/ CLOUD.
SHORT TERM NWP DOES NOT SUGGEST ANY SEEDING FROM HIGHER CLOUD IS
POSSIBLE. GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE THIS
MORNING...WILL MAINTAIN SLIGHT CHANCE OF SN/DZ/FZDZ THROUGH NOON.
THEN...THE HRRR SUGGESTS THAT ANY REMAINING DRIZZLE WILL END WITH
SOME SLIGHT LOW LEVEL MIXING.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TONIGHT.
STRONG WARM ADVECTION AND ISENTROPIC LIFT WILL MOVE NORTHWARD INTO
THE UPPER GREAT LAKES BY SUNDAY MORNING. THE 00Z NWP SEEM BE BE IN
EXCELLENT AGREEMENT IN BRINGING RAIN ACROSS MUCH OF THE SOUTHERN
HALF OF THE U.P. AFT 09Z AND TO THE MAJORITY OF UPPER MI EXCEPT THE
KEWEENAW AND THE EASTERN 1/3 BY 12Z. AS SUCH...WILL KEEP POPS
MINIMAL THIS EVENING...THE RAPIDLY RAISE TO LIKELY ACROSS THE WEST
AND CENTRAL BTWN 09-12Z. IN FACT...WILL GO WITH CATEGORICAL POPS
FOR FAR SOUTHERN MENOMINEE COUNTY BY 12Z.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 533 AM EST SAT DEC 12 2015
MODELS ADVERTISE AN ACTIVE PROGRESSIVE PATTERN FOR THE LONG TERM
STARTING OUT WITH A STRONG LOW PRESSURE SYSTEM FROM THE PLAINS
LIFTING NE INTO THE UPPER GREAT LAKES FOR SUNDAY AND MONDAY FOLLOWED
BY ANOTHER PLAINS SYSTEM MOVING IN FOR TUE NIGHT AND WED. THIS
SECOND SYSTEM IS FOLLOWED BY A SERIES OF CLIPPER SHORTWAVES WHICH
WILL BRING IN COLDER AIR FM NW CANADA BY LATE NEXT WEEK. AS A
RESULT...TEMPS WILL START OUT WELL ABOVE NORMAL WITH NEAR RECORD
VALUES INTO MONDAY BUT WILL THEN DROP OFF CLOSER TO NORMAL VALUES BY
THU-FRI.
SUNDAY THROUGH MONDAY...A STRONG SRN STREAM SYSTEM IS EXPECTED TO
LIFT FROM THE SRN PLAINS TO THE WRN LAKES. THE 00Z/12 ECMWF IS
PERHAPS SLIGHTLY SLOWER INITIALLY THAN 00Z GFS AND CANADIAN WITH
ARRIVAL OF OCCLUDING SFC LOW LATE MONDAY BUT OTHERWISE MODELS
GENERALLY IN GOOD AGREEMENT. ALL MODELS SHOW A SIMILAR TRACK ACROSS
THE CENTRAL U.P. ON MONDAY BRINGING PLENTY OF WARM AIR INTO THE CWA
TO SUPPORT MOSTLY RAIN THROUGH MONDAY. VERY STRONG MOISTURE
ADVECTION WILL PUSH PWAT VALUES TO CLIMATOLOGICALLY EXTREME VALUES
NEAR 1.20 INCH OR TO ABOUT A 6.0 SIGMA STANDARDIZED ANOMALY. THIS
STRONG MOISTURE ADVECTION COMBINED WITH STRONG DEEP LAYER Q-VECTOR
CONVERGENCE AND ENHANCED 700 MB FGEN IN RESPONSE TO INCREASED UPPER
DIVERGENCE FROM COUPLED UPPER JET STRUCTURE WILL LIKELY LEAD TO
STORM TOTAL RAINFALL AMOUNTS THROUGH PERIOD IN THE 2 TO 3 INCH RANGE
ACROSS THE CWA WITH THE HEAVIEST AMOUNTS LIKELY OVER THE WEST HALF
SUN NIGHT INTO MONDAY. THE INITIAL BATCH OF RAIN ON SUNDAY WILL
PRIMARILY BE SUPPORTED BY AN AREA OF 290K-300K ISENTROPIC LIFT WITH
RAIN SPREADING TO THE NORTH THROUGH THE CWA.
MON NIGHT-FRI...MODEL THICKNESS/SOUNDINGS AND WET BULB ZERO
CALCULATIONS SUGGEST RAIN WILL FINALLY BEGIN TO CHANGE TO SNOW FROM
WEST TO EAST MON NIGHT INTO TUE...BUT BY THIS TIME MODELS INDICATE
THAT THE HEAVIER PCPN ASSOC WITH THE COMMA HEAD/DEFORMATION AREA OF
SYSTEM WILL HAVE EXITED TO THE EAST. SO ANY SNOW WE GET FROM THIS
SYSTEM LOOKS LIKE IT WILL BE LIGHT (LESS THAN AN INCH) AND CONFINED
TO THE WEST. AFTER LIGHT LES ON TUESDAY IN N-NE FLOW ALONG LAKE
SUPERIOR COUNTIES...MODELS SHOW ANOTHER SHORTWAVE AND ASSOC SFC LOW
APPROACHING FROM THE CENTRAL PLAINS AND UPPER MS VALLEY ON WED. WITH
MODELS TRENDING EVEN FARTHER WEST WITH THIS SYSTEM RAIN IS MORE
LIKELY CENTRAL AND EAST WITH A RAIN/SNOW MIX WEST. A SERIES OF
CLIPPER SHORTWAVES IN THE WAKE OF THE MIDWEEK SYSTEM...WILL BRING IN
COLDER AIR AS 850 MB TEMPS LOWER TO -15C OR COLDER BY FRIDAY. THIS
WILL SUPPORT INCREASING LES CHANCES FOR WESTERLY FLOW FAVORED
LOCATIONS...PARTICULARLY OVER THE KEWEENAW WHERE ADVISORY LES SNOWS
MAY BE POSSIBLE FROM LATE THU INTO FRI.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1224 PM EST SAT DEC 12 2015
EXPECT CONDITIONS TO REMAIN OF THE BORDER BETWEEN IFR AND LOW MVFR
TODAY. DEEPER MOISTURE RETURNS TO THE AREA TONIGHT AHEAD OF THE LOW
PRESSURE SYSTEM. EXPECT IFR TI LIFR CIGS TO SPREAD ACROSS THE ENTIRE
AREA OVERNIGHT WITH RAIN DEVELOPING LATE. THOSE CONDITIONS WILL
PERSIST THROUGH SUNDAY.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 330 AM EST SAT DEC 12 2015
AS LOW PRESSURE OVER THE CENTRAL PLAINS DEVELOPS AND MOVES NORTHEAST
TODAY...EXPECT EAST-NORTHEAST WINDS TO SLOWLY INCREASE TODAY...WITH
WINDS OF 25KT ACROSS THE WEST HALF BY THIS EVENING. AS THE LOW
CONTINUES TO MOVE NORTHEAST TOWARD THE GREAT LAKES LATER TONIGHT
INTO SUNDAY NIGHT...WINDS WILL CONTINUE TO INCREASE WITH WINDS OF
GALE FORCE ACROSS THE WEST HALF BY SUNDAY AFTERNOON. NE GALES WILL
CONTINUE INTO MONDAY NIGHT ACROSS THE WEST HALF AND MAY ALSO SPREAD
TO THE EAST HALF ON MONDAY AFTERNOON AS THE LOW FINALLY MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE ON
NORTHERLY WINDS. WINDS WILL SUBSIDE TO 20 KT BY TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES INTO THE UPPER GREAT
LAKES FOR WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...VOSS
AVIATION...MZ
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
633 AM EST SAT DEC 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM EST SAT DEC 12 2015
...QUIET WEATHER TODAY BEFORE SIGNIFICANT RAINFALL SUNDAY INTO
MONDAY...
WEAK E-NE UPSLOPE FLOW CONTINUES...ALLOWING FOR SNOW SHOWERS ALONG
NORTH CENTRAL UPPER MICHIGAN AS WELL AS IN THE KEWEENAW. IT IS
ACTUALLY INTERESTING THAT THE PRECIPITATION IS SNOW RATHER THAN
DRIZZLE/FREEZING DRIZZLE AS IT WOULD SEEM HARD TO IMAGINE MUCH ICE
NUCLEI IN THE SHALLOW /2000 FT/ AND RELATIVELY WARM /-4C/ CLOUD.
SHORT TERM NWP DOES NOT SUGGEST ANY SEEDING FROM HIGHER CLOUD IS
POSSIBLE. GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE THIS
MORNING...WILL MAINTAIN SLIGHT CHANCE OF SN/DZ/FZDZ THROUGH NOON.
THEN...THE HRRR SUGGESTS THAT ANY REMAINING DRIZZLE WILL END WITH
SOME SLIGHT LOW LEVEL MIXING.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TONIGHT.
STRONG WARM ADVECTION AND ISENTROPIC LIFT WILL MOVE NORTHWARD INTO
THE UPPER GREAT LAKES BY SUNDAY MORNING. THE 00Z NWP SEEM BE BE IN
EXCELLENT AGREEMENT IN BRINGING RAIN ACROSS MUCH OF THE SOUTHERN
HALF OF THE U.P. AFT 09Z AND TO THE MAJORITY OF UPPER MI EXCEPT THE
KEWEENAW AND THE EASTERN 1/3 BY 12Z. AS SUCH...WILL KEEP POPS
MINIMAL THIS EVENING...THE RAPIDLY RAISE TO LIKELY ACROSS THE WEST
AND CENTRAL BTWN 09-12Z. IN FACT...WILL GO WITH CATEGORICAL POPS
FOR FAR SOUTHERN MENOMINEE COUNTY BY 12Z.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 533 AM EST SAT DEC 12 2015
MODELS ADVERTISE AN ACTIVE PROGRESSIVE PATTERN FOR THE LONG TERM
STARTING OUT WITH A STRONG LOW PRESSURE SYSTEM FROM THE PLAINS
LIFTING NE INTO THE UPPER GREAT LAKES FOR SUNDAY AND MONDAY FOLLOWED
BY ANOTHER PLAINS SYSTEM MOVING IN FOR TUE NIGHT AND WED. THIS
SECOND SYSTEM IS FOLLOWED BY A SERIES OF CLIPPER SHORTWAVES WHICH
WILL BRING IN COLDER AIR FM NW CANADA BY LATE NEXT WEEK. AS A
RESULT...TEMPS WILL START OUT WELL ABOVE NORMAL WITH NEAR RECORD
VALUES INTO MONDAY BUT WILL THEN DROP OFF CLOSER TO NORMAL VALUES BY
THU-FRI.
SUNDAY THROUGH MONDAY...A STRONG SRN STREAM SYSTEM IS EXPECTED TO
LIFT FROM THE SRN PLAINS TO THE WRN LAKES. THE 00Z/12 ECMWF IS
PERHAPS SLIGHTLY SLOWER INITIALLY THAN 00Z GFS AND CANADIAN WITH
ARRIVAL OF OCCLUDING SFC LOW LATE MONDAY BUT OTHERWISE MODELS
GENERALLY IN GOOD AGREEMENT. ALL MODELS SHOW A SIMILAR TRACK ACROSS
THE CENTRAL U.P. ON MONDAY BRINGING PLENTY OF WARM AIR INTO THE CWA
TO SUPPORT MOSTLY RAIN THROUGH MONDAY. VERY STRONG MOISTURE
ADVECTION WILL PUSH PWAT VALUES TO CLIMATOLOGICALLY EXTREME VALUES
NEAR 1.20 INCH OR TO ABOUT A 6.0 SIGMA STANDARDIZED ANOMALY. THIS
STRONG MOISTURE ADVECTION COMBINED WITH STRONG DEEP LAYER Q-VECTOR
CONVERGENCE AND ENHANCED 700 MB FGEN IN RESPONSE TO INCREASED UPPER
DIVERGENCE FROM COUPLED UPPER JET STRUCTURE WILL LIKELY LEAD TO
STORM TOTAL RAINFALL AMOUNTS THROUGH PERIOD IN THE 2 TO 3 INCH RANGE
ACROSS THE CWA WITH THE HEAVIEST AMOUNTS LIKELY OVER THE WEST HALF
SUN NIGHT INTO MONDAY. THE INITIAL BATCH OF RAIN ON SUNDAY WILL
PRIMARILY BE SUPPORTED BY AN AREA OF 290K-300K ISENTROPIC LIFT WITH
RAIN SPREADING TO THE NORTH THROUGH THE CWA.
MON NIGHT-FRI...MODEL THICKNESS/SOUNDINGS AND WET BULB ZERO
CALCULATIONS SUGGEST RAIN WILL FINALLY BEGIN TO CHANGE TO SNOW FROM
WEST TO EAST MON NIGHT INTO TUE...BUT BY THIS TIME MODELS INDICATE
THAT THE HEAVIER PCPN ASSOC WITH THE COMMA HEAD/DEFORMATION AREA OF
SYSTEM WILL HAVE EXITED TO THE EAST. SO ANY SNOW WE GET FROM THIS
SYSTEM LOOKS LIKE IT WILL BE LIGHT (LESS THAN AN INCH) AND CONFINED
TO THE WEST. AFTER LIGHT LES ON TUESDAY IN N-NE FLOW ALONG LAKE
SUPERIOR COUNTIES...MODELS SHOW ANOTHER SHORTWAVE AND ASSOC SFC LOW
APPROACHING FROM THE CENTRAL PLAINS AND UPPER MS VALLEY ON WED. WITH
MODELS TRENDING EVEN FARTHER WEST WITH THIS SYSTEM RAIN IS MORE
LIKELY CENTRAL AND EAST WITH A RAIN/SNOW MIX WEST. A SERIES OF
CLIPPER SHORTWAVES IN THE WAKE OF THE MIDWEEK SYSTEM...WILL BRING IN
COLDER AIR AS 850 MB TEMPS LOWER TO -15C OR COLDER BY FRIDAY. THIS
WILL SUPPORT INCREASING LES CHANCES FOR WESTERLY FLOW FAVORED
LOCATIONS...PARTICULARLY OVER THE KEWEENAW WHERE ADVISORY LES SNOWS
MAY BE POSSIBLE FROM LATE THU INTO FRI.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 632 AM EST SAT DEC 12 2015
LOWER END MVFR AND LOCALIZED IFR CONDITIONS ARE ONGOING AT TIME. AM
ACTUALLY SURPRISED THAT SAW IS NOT LOWER THAN MVFR WITH THE UPSLOPE
E-NE FLOW. HOWEVER...EXPECT CONDITIONS TO BE IN THE IFR/LOW MVFR
RANGE THROUGHOUT THE DAY TODAY. DEEPER MOISTURE RETURNS TO THE AREA
TONIGHT AHEAD OF THE LOW PRESSURE SYSTEM. EXPECT IFR CIGS TO SPREAD
ACROSS THE ENTIRE AREA OVERNIGHT WITH RAIN DEVELOPING LATE. COULD
SEE LIFR CONDITIONS ON SUNDAY WITH MODERATE RAIN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 330 AM EST SAT DEC 12 2015
AS LOW PRESSURE OVER THE CENTRAL PLAINS DEVELOPS AND MOVES NORTHEAST
TODAY...EXPECT EAST-NORTHEAST WINDS TO SLOWLY INCREASE TODAY...WITH
WINDS OF 25KT ACROSS THE WEST HALF BY THIS EVENING. AS THE LOW
CONTINUES TO MOVE NORTHEAST TOWARD THE GREAT LAKES LATER TONIGHT
INTO SUNDAY NIGHT...WINDS WILL CONTINUE TO INCREASE WITH WINDS OF
GALE FORCE ACROSS THE WEST HALF BY SUNDAY AFTERNOON. NE GALES WILL
CONTINUE INTO MONDAY NIGHT ACROSS THE WEST HALF AND MAY ALSO SPREAD
TO THE EAST HALF ON MONDAY AFTERNOON AS THE LOW FINALLY MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE ON
NORTHERLY WINDS. WINDS WILL SUBSIDE TO 20 KT BY TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES INTO THE UPPER GREAT
LAKES FOR WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...VOSS
AVIATION...MRD
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
535 AM EST SAT DEC 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM EST SAT DEC 12 2015
...QUIET WEATHER TODAY BEFORE SIGNIFICANT RAINFALL SUNDAY INTO
MONDAY...
WEAK E-NE UPSLOPE FLOW CONTINUES...ALLOWING FOR SNOW SHOWERS ALONG
NORTH CENTRAL UPPER MICHIGAN AS WELL AS IN THE KEWEENAW. IT IS
ACTUALLY INTERESTING THAT THE PRECIPITATION IS SNOW RATHER THAN
DRIZZLE/FREEZING DRIZZLE AS IT WOULD SEEM HARD TO IMAGINE MUCH ICE
NUCLEI IN THE SHALLOW /2000 FT/ AND RELATIVELY WARM /-4C/ CLOUD.
SHORT TERM NWP DOES NOT SUGGEST ANY SEEDING FROM HIGHER CLOUD IS
POSSIBLE. GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE THIS
MORNING...WILL MAINTAIN SLIGHT CHANCE OF SN/DZ/FZDZ THROUGH NOON.
THEN...THE HRRR SUGGESTS THAT ANY REMAINING DRIZZLE WILL END WITH
SOME SLIGHT LOW LEVEL MIXING.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TONIGHT.
STRONG WARM ADVECTION AND ISENTROPIC LIFT WILL MOVE NORTHWARD INTO
THE UPPER GREAT LAKES BY SUNDAY MORNING. THE 00Z NWP SEEM BE BE IN
EXCELLENT AGREEMENT IN BRINGING RAIN ACROSS MUCH OF THE SOUTHERN
HALF OF THE U.P. AFT 09Z AND TO THE MAJORITY OF UPPER MI EXCEPT THE
KEWEENAW AND THE EASTERN 1/3 BY 12Z. AS SUCH...WILL KEEP POPS
MINIMAL THIS EVENING...THE RAPIDLY RAISE TO LIKELY ACROSS THE WEST
AND CENTRAL BTWN 09-12Z. IN FACT...WILL GO WITH CATEGORICAL POPS
FOR FAR SOUTHERN MENOMINEE COUNTY BY 12Z.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 533 AM EST SAT DEC 12 2015
MODELS ADVERTISE AN ACTIVE PROGRESSIVE PATTERN FOR THE LONG TERM
STARTING OUT WITH A STRONG LOW PRESSURE SYSTEM FROM THE PLAINS
LIFTING NE INTO THE UPPER GREAT LAKES FOR SUNDAY AND MONDAY FOLLOWED
BY ANOTHER PLAINS SYSTEM MOVING IN FOR TUE NIGHT AND WED. THIS
SECOND SYSTEM IS FOLLOWED BY A SERIES OF CLIPPER SHORTWAVES WHICH
WILL BRING IN COLDER AIR FM NW CANADA BY LATE NEXT WEEK. AS A
RESULT...TEMPS WILL START OUT WELL ABOVE NORMAL WITH NEAR RECORD
VALUES INTO MONDAY BUT WILL THEN DROP OFF CLOSER TO NORMAL VALUES BY
THU-FRI.
SUNDAY THROUGH MONDAY...A STRONG SRN STREAM SYSTEM IS EXPECTED TO
LIFT FROM THE SRN PLAINS TO THE WRN LAKES. THE 00Z/12 ECMWF IS
PERHAPS SLIGHTLY SLOWER INITIALLY THAN 00Z GFS AND CANADIAN WITH
ARRIVAL OF OCCLUDING SFC LOW LATE MONDAY BUT OTHERWISE MODELS
GENERALLY IN GOOD AGREEMENT. ALL MODELS SHOW A SIMILAR TRACK ACROSS
THE CENTRAL U.P. ON MONDAY BRINGING PLENTY OF WARM AIR INTO THE CWA
TO SUPPORT MOSTLY RAIN THROUGH MONDAY. VERY STRONG MOISTURE
ADVECTION WILL PUSH PWAT VALUES TO CLIMATOLOGICALLY EXTREME VALUES
NEAR 1.20 INCH OR TO ABOUT A 6.0 SIGMA STANDARDIZED ANOMALY. THIS
STRONG MOISTURE ADVECTION COMBINED WITH STRONG DEEP LAYER Q-VECTOR
CONVERGENCE AND ENHANCED 700 MB FGEN IN RESPONSE TO INCREASED UPPER
DIVERGENCE FROM COUPLED UPPER JET STRUCTURE WILL LIKELY LEAD TO
STORM TOTAL RAINFALL AMOUNTS THROUGH PERIOD IN THE 2 TO 3 INCH RANGE
ACROSS THE CWA WITH THE HEAVIEST AMOUNTS LIKELY OVER THE WEST HALF
SUN NIGHT INTO MONDAY. THE INITIAL BATCH OF RAIN ON SUNDAY WILL
PRIMARILY BE SUPPORTED BY AN AREA OF 290K-300K ISENTROPIC LIFT WITH
RAIN SPREADING TO THE NORTH THROUGH THE CWA.
MON NIGHT-FRI...MODEL THICKNESS/SOUNDINGS AND WET BULB ZERO
CALCULATIONS SUGGEST RAIN WILL FINALLY BEGIN TO CHANGE TO SNOW FROM
WEST TO EAST MON NIGHT INTO TUE...BUT BY THIS TIME MODELS INDICATE
THAT THE HEAVIER PCPN ASSOC WITH THE COMMA HEAD/DEFORMATION AREA OF
SYSTEM WILL HAVE EXITED TO THE EAST. SO ANY SNOW WE GET FROM THIS
SYSTEM LOOKS LIKE IT WILL BE LIGHT (LESS THAN AN INCH) AND CONFINED
TO THE WEST. AFTER LIGHT LES ON TUESDAY IN N-NE FLOW ALONG LAKE
SUPERIOR COUNTIES...MODELS SHOW ANOTHER SHORTWAVE AND ASSOC SFC LOW
APPROACHING FROM THE CENTRAL PLAINS AND UPPER MS VALLEY ON WED. WITH
MODELS TRENDING EVEN FARTHER WEST WITH THIS SYSTEM RAIN IS MORE
LIKELY CENTRAL AND EAST WITH A RAIN/SNOW MIX WEST. A SERIES OF
CLIPPER SHORTWAVES IN THE WAKE OF THE MIDWEEK SYSTEM...WILL BRING IN
COLDER AIR AS 850 MB TEMPS LOWER TO -15C OR COLDER BY FRIDAY. THIS
WILL SUPPORT INCREASING LES CHANCES FOR WESTERLY FLOW FAVORED
LOCATIONS...PARTICULARLY OVER THE KEWEENAW WHERE ADVISORY LES SNOWS
MAY BE POSSIBLE FROM LATE THU INTO FRI.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1233 AM EST SAT DEC 12 2015
AT THE LEAST...LOW TO MID RANGE MVFR CIGS ARE EXPECTED AT ALL SITES
THROUGH THE PERIOD AS MOISTURE REMAINS TRAPPED BELOW AN INVERSION.
DUE TO UPSLOPE EASTERLY FLOW...LOWER CIGS ALONG WITH FOG AND
POSSIBLY SOME DZ/FZDZ COULD FORM LATER TONIGHT AT KSAW AND
KCMX...BUT CONFIDENCE ON THE EXTENT REMAINS LOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 330 AM EST SAT DEC 12 2015
AS LOW PRESSURE OVER THE CENTRAL PLAINS DEVELOPS AND MOVES NORTHEAST
TODAY...EXPECT EAST-NORTHEAST WINDS TO SLOWLY INCREASE TODAY...WITH
WINDS OF 25KT ACROSS THE WEST HALF BY THIS EVENING. AS THE LOW
CONTINUES TO MOVE NORTHEAST TOWARD THE GREAT LAKES LATER TONIGHT
INTO SUNDAY NIGHT...WINDS WILL CONTINUE TO INCREASE WITH WINDS OF
GALE FORCE ACROSS THE WEST HALF BY SUNDAY AFTERNOON. NE GALES WILL
CONTINUE INTO MONDAY NIGHT ACROSS THE WEST HALF AND MAY ALSO SPREAD
TO THE EAST HALF ON MONDAY AFTERNOON AS THE LOW FINALLY MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE ON
NORTHERLY WINDS. WINDS WILL SUBSIDE TO 20 KT BY TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES INTO THE UPPER GREAT
LAKES FOR WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...VOSS
AVIATION...JLA
MARINE...MRD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
331 AM EST SAT DEC 12 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM EST SAT DEC 12 2015
...QUIET WEATHER TODAY BEFORE SIGNIFICANT RAINFALL SUNDAY INTO
MONDAY...
WEAK E-NE UPSLOPE FLOW CONTINUES...ALLOWING FOR SNOW SHOWERS ALONG
NORTH CENTRAL UPPER MICHIGAN AS WELL AS IN THE KEWEENAW. IT IS
ACTUALLY INTERESTING THAT THE PRECIPITATION IS SNOW RATHER THAN
DRIZZLE/FREEZING DRIZZLE AS IT WOULD SEEM HARD TO IMAGINE MUCH ICE
NUCLEI IN THE SHALLOW /2000 FT/ AND RELATIVELY WARM /-4C/ CLOUD.
SHORT TERM NWP DOES NOT SUGGEST ANY SEEDING FROM HIGHER CLOUD IS
POSSIBLE. GIVEN A SIMILAR THERMAL AND MOISTURE PROFILE THIS
MORNING...WILL MAINTAIN SLIGHT CHANCE OF SN/DZ/FZDZ THROUGH NOON.
THEN...THE HRRR SUGGESTS THAT ANY REMAINING DRIZZLE WILL END WITH
SOME SLIGHT LOW LEVEL MIXING.
LOW PRESSURE OVER THE CENTRAL PLAINS WILL MOVE NORTHEAST TONIGHT.
STRONG WARM ADVECTION AND ISENTROPIC LIFT WILL MOVE NORTHWARD INTO
THE UPPER GREAT LAKES BY SUNDAY MORNING. THE 00Z NWP SEEM BE BE IN
EXCELLENT AGREEMENT IN BRINGING RAIN ACROSS MUCH OF THE SOUTHERN
HALF OF THE U.P. AFT 09Z AND TO THE MAJORITY OF UPPER MI EXCEPT THE
KEWEENAW AND THE EASTERN 1/3 BY 12Z. AS SUCH...WILL KEEP POPS
MINIMAL THIS EVENING...THE RAPIDLY RAISE TO LIKELY ACROSS THE WEST
AND CENTRAL BTWN 09-12Z. IN FACT...WILL GO WITH CATEGORICAL POPS
FOR FAR SOUTHERN MENOMINEE COUNTY BY 12Z.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 443 PM EST FRI DEC 11 2015
MODELS SUGGEST THAT AN ACTIVE PROGRESSIVE PATTERN WILL ALLOW COLDER
AIR OVER THE WEST TO SLIDE INTO THE THE CNTRL CONUS BY LATER NEXT
WEEK. AS A RESULT...TEMPS STARTING OUT WELL ABOVE NORMAL...NEAR
RECORD VALUES INTO MONDAY WILL DROP OFF TO CLOSER TO NORMAL VALUES BY
THU-FRI.
SATURDAY NIGHT THROUGH MONDAY...A STRONG SRN STREAM SYSTEM IS
EXPECTED TO LIFT FROM THE SRN PLAINS TO THE WRN LAKES. THE 12Z/11
ECMWF REMAINS SLOWER WITH THE SYSTEM COMPARED TO THE 12Z GFS/GEM
WITH THE OCCLUDED SFC LOW SLIDING OFF TO THE EAST THROUGH UPPER MI
LATE MON INSTEAD OF LIFTING THE SFC LOW INTO LAKE SUPERIOR MONDAY.
HOWEVER...EITHER SCENARIO WILL BRING PLENTY OF WARM AIR INTO THE CWA
TO SUPPORT ONLY RAIN THROUGH SUN NIGHT. VERY STRONG MOISTURE
ADVECTION WILL PUSH PWAT VALUES TO CLIMATOLOGICALLY EXTREME VALUES
NEAR 1.30 INCH OR TO ABOUT A 6.0 SIGMA STANDARDIZED ANOMALY. TOTAL
RAINFALL AMOUNTS THROUGH IN THE 2 TO 3 INCH RANGE WILL BE POSSIBLE
ACROSS THE CWA WITH THE HEAVIEST AMOUNTS LIKELY OVER THE WEST HALF.
THE INITIAL BATCH OF RAIN WILL BE SUPPORTED BY AN AREA OF 290K-300K
ISENTROPIC LIFT WITH RAIN SPREADING TO THE NORTH THROUGH THE CWA AFT
06Z SUN. ADDITIONAL PERIODS OF RAIN SUN WILL BE SUPPORTED AS WEAKER
SHORTWAVES AHEAD OF THE MAIN SYSTEM LIFT TO THE NORTH. THE HEAVIEST
RAIN IS EXPECTED FROM SUN NIGHT INTO EARLY MONDAY WITH STRONG DEEP
LAYER QVECTOR CONV AND UPPER LEVEL DIV AS THE MID LEVEL LOW LIFTS TO
NE IA AND SRN WI. A BLEND OF THE GFS/ECMWF MAX TEMP ALOFT USED IN
DEFINING PCPN TYPE THROUGH MONDAY. A GRADUAL MIX TO WET SNOW FROM
WEST TO EAST WILL BE POSSIBLE OVER THE WEST MON MORNING AND CNTRL
UPPER MI BY LATE AFTERNOON AND EVENING. SNOW AMOUNTS OF A FEW INCHES
MAY BE POSSIBLE. HOWEVER...GIVEN THE SIGNIFICANT MODEL DIFFERENCES
CONFIDENCE IS LOW.
TUE-FRI...THE GFS/GEFS AND ECMWF SUGGEST ANOTHER SHORTWAVE AND SFC
LOW WILL LIFT FROM THE CNTRL PLAINS TO THE UPPER MS VALLEY AND LAKE
SUPERIOR BY WED. WARMER AIR TO THE EAST OF THE CONSENSUS LOW TRACK
WILL FAVOR MAINLY RAIN OVER THE EAST HALF OF UPPER MI WITH SNOW OVER
WEST. THE ECMWF WAS AGAIN SLIGHTLY WARMER THAN THE GFS/GEM. IN THE
WAKE OF THE SYSTEM...COLDER AIR MOVES IN THE 850 MB TEMPS TO AROUND
-15C. THIS WILL SUPPORT INCREASING LES CHANCES FOR W TO NW FLOW
FAVORED LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1233 AM EST SAT DEC 12 2015
AT THE LEAST...LOW TO MID RANGE MVFR CIGS ARE EXPECTED AT ALL SITES
THROUGH THE PERIOD AS MOISTURE REMAINS TRAPPED BELOW AN INVERSION.
DUE TO UPSLOPE EASTERLY FLOW...LOWER CIGS ALONG WITH FOG AND
POSSIBLY SOME DZ/FZDZ COULD FORM LATER TONIGHT AT KSAW AND
KCMX...BUT CONFIDENCE ON THE EXTENT REMAINS LOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 330 AM EST SAT DEC 12 2015
AS LOW PRESSURE OVER THE CENTRAL PLAINS DEVELOPS AND MOVES NORTHEAST
TODAY...EXPECT EAST-NORTHEAST WINDS TO SLOWLY INCREASE TODAY...WITH
WINDS OF 25KT ACROSS THE WEST HALF BY THIS EVENING. AS THE LOW
CONTINUES TO MOVE NORTHEAST TOWARD THE GREAT LAKES LATER TONIGHT
INTO SUNDAY NIGHT...WINDS WILL CONTINUE TO INCREASE WITH WINDS OF
GALE FORCE ACROSS THE WEST HALF BY SUNDAY AFTERNOON. NE GALES WILL
CONTINUE INTO MONDAY NIGHT ACROSS THE WEST HALF AND MAY ALSO SPREAD
TO THE EAST HALF ON MONDAY AFTERNOON AS THE LOW FINALLY MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE ON
NORTHERLY WINDS. WINDS WILL SUBSIDE TO 20 KT BY TUESDAY BEFORE
ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES INTO THE UPPER GREAT
LAKES FOR WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ162-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...MRD
LONG TERM...JLB
AVIATION...JLA
MARINE...MRD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1056 PM CST FRI DEC 11 2015
.UPDATE...
ISSUED AT 1047 PM CST FRI DEC 11 2015
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 340 PM CST FRI DEC 11 2015
THE SHORT TERM IS DEFINITELY THE CALM BEFORE THE STORM WITH THE
BIG CHANGE MADE THROUGH THE DAY SATURDAY BEING TO REDUCE POPS
THROUGHOUT THE PERIOD.
THIS AFTERNOON...THE SFC RIDGE THAT WORKED ACROSS MN THIS MORNING
IS NOW WORKING ACROSS WI...WITH EASTERLY LOW LEVEL WINDS SETTING
UP AS LEE CYCLOGENESIS SLOWLY EVOLVES ACROSS COLORADO. LEAD
SHORTWAVE EMANATING FROM THE MAIN WRN THROUGH IS WORKING ACROSS
CENTRAL NODAK THIS AFTERNOON AND IS ON ITS WAY FOR SOUTHERN
MANITOBA. PRECIP ASSOCIATED WITH THIS WAVE HAS BEEN TIED TO
MOISTURE AND ISENTROPIC LIFT ON THE 295K SFC...AND THE RAP SHOWS
THIS AREA OF FORCING/MOISTURE HEADING FOR NW MN...SO REMOVED WHAT
LITTLE POPS WE HAD FOR TODAY AND THIS EVENING ACROSS WESTERN AND
CENTRAL MN.
LATER TONIGHT...WE WILL SEE ANOTHER AREA OF PRECIP PUSH NORTH ON
THE LEADING EDGE OF THE FIRST MOISTURE SURGE. THERE WILL LIKELY
BE AN AREA OF DRIZZLE/LIGHT RAIN ASSOCIATED WITH IT...BUT PRIMARY
MOISTURE TRANSPORT AT 925MB WILL BE GOING FROM EASTERN IOWA TOWARD
THE MICH/WI BORDER. AS A RESULT...KEPT THE FORECAST DRY FOR
TONIGHT ACROSS THE ENTIRE MPX CWA...AS ANY DZ/RA PRODUCTION LOOKS
TO OCCUR SOUTHEAST OF OUR FORECAST AREA.
FOR SATURDAY...CONTINUED THE TREND OF DRYING THE FORECAST AS
WELL...AS GUIDANCE IS IN GOOD AGREEMENT ON THE BULK OF THE PRECIP
WITH THIS WEEKENDS SYSTEM COMING AFTER 00Z SUNDAY /SATURDAY
EVENING/. THE ONE EXCEPTION IS THE DEVELOPMENT OF A BAND OF
ELEVATED FGEN IN THE H7-H6 LAYER SATURDAY AFTERNOON. MOST
GUIDANCE...CAM AND NON-CAM ALIKE...SHOW A BAND OF PRECIP
DEVELOPING IN WRN MN AND WORKING UP TO CENTRAL MN DURING THE
AFTERNOON...SO THIS WAS WHERE PRECIP MENTION WAS MAINTAINED...
EVERYWHERE ELSE WE KEPT DRY UNTIL WE GET INTO SATURDAY EVENING...
WHEN THINGS LOOK TO GO DOWNHILL PRETTY QUICK. LOOKS PLENTY WARM
ENOUGH SATURDAY AFTERNOON TO KEEP THE VAST MAJORITY OF THE PRECIP
WE SEE AS RAIN...THOUGH WE MAY SEE A SNOWFLAKE OR TWO MIX IN OUT
TOWARD ALEXANDRIA. WITH RAIN EXPECTED TO DOMINATE...REMOVED ANY
SNOW ACCUMULATIONS FROM SATURDAY AS WELL.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 PM CST FRI DEC 11 2015
WIDESPREAD RAIN IS STILL ON TRACK FOR THE WEEKEND INTO MONDAY WITH
1-3 INCHES OF RAIN IN THE EASTERN FORECAST AREA...TAPERING TO
ABOUT A HALF INCH OF LIQUID IN WESTERN MN. AT THIS POINT...WESTERN
MN IS THE MOST SUSCEPTIBLE TO A FEW INCHES OF SNOW GIVEN THE
COOLER TEMPERATURE PROFILE IN THIS AREA.
THE NAM AND ECMWF HAVE BEEN DIALED IN WITH ONLY SMALL WOBBLES IN
THE SURFACE LOW TRACK OVER THE PAST 3 RUNS GOING BACK TO LAST
NIGHT. THE GFS HAS SHOWN A LITTLE MORE RUN-TO-RUN VARIABILITY OVER
THE PAST 3-4 RUNS. AS PREVIOUS DISCUSSIONS HAVE MENTIONED...THE
FORECAST LOW TRACK HAS THE LOOK OF A MAJOR WINTER STORM...ITS
SIMPLY TOO WARM. BOTH THE 60HR CIPS ANALOG FROM THE NAM AND THE
72HR ANALOG FROM THE GFS SUGGEST WE SHOULD BE GETTING READY TO
ISSUE WINTER STORM WATCH HEADLINES ACROSS MOST OF OUR MINNESOTA
COUNTIES...AGAIN NOT EVEN CLOSE WITH THESE TEMPERATURES. WHAT WE
ARE CONFIDENT IN...IS WIDESPREAD 1"+ RAIN TOTALS ACROSS EASTERN
MN AND WESTERN WI. WE NOW HAVE 100% RAIN IN THE FORECAST FOR
SEVERAL PERIODS SAT-MON. SOUTHEAST MN AND WESTERN WI COULD GET A
FEW RUMBLES OF THUNDER AS WELL.
THE MODEL CONSENSUS IS FOR A LOW TRACK OUT OF THE SOUTHERN PLAINS
ACROSS NORTHEAST IA AND INTO NORTHERN WI FROM SATURDAY NIGHT INTO
MONDAY MORNING. THERE WILL BE TWO MAIN BURSTS OF PRECIP...THE
FIRST IS WITH THE MOISTURE SURGE AND ISENTROPIC LIFT SATURDAY
NIGHT...FOLLOWED BY A RELATIVE LULL...AND THE SECOND SURGE SUNDAY
MORNING/AFTERNOON WITH THE CLASSIC FLUID DEFORMATION - THIS LINGERS
INTO MONDAY. THE ONE AREA OF CONCERN IS IN WESTERN MN...WHERE SOME
OF THE MODEL GUIDANCE HAS TRENDED A BIT COOLER. AS IT STANDS
NOW...WE ARE FORECASTING 1-3" OF SNOW NEAR AND WEST OF A LINE FROM
GRANITE FALLS...TO SAUK CENTRE...TO STAPLES - WITH A WINTRY MIX OF
PRECIP. THE COLD SIDE OF THIS SYSTEM ISN/T AS COLD AS WE MIGHT
EXPECT...WHICH IS WHY WE AREN`T GOING WITH HIGHER SNOW TOTALS AT
THIS POINT. HOWEVER...STRONG SYSTEMS LIKE THIS THAT DEEPEN AS
THEY LIFT OUT OF THE PLAINS CAN DYNAMICALLY LOWER THE FREEZING
LEVEL AND GIVE YOU A QUICKER CHANGEOVER TO SNOW. IF THAT WERE TO
HAPPEN...LOCATIONS SUCH AS ALEXANDRIA...GRANITE FALLS AND BENSON
COULD END UP WITH SEVERAL INCHES OF SNOW - MAYBE AS MUCH AS 6".
WE`LL CONTINUE TO WATCH OUR WESTERN MN AREA CLOSELY. THE
FORECAST SOUNDINGS DEFINITELY SHOW MORE SLEET IN THESE AREAS AS
WELL BECAUSE THEY HAVE COOLED BUT CONTINUE TO SHOW A WARM LAYER
ALOFT.
THE TRAILING SYSTEM TUESDAY NIGHT AND WEDNESDAY STILL LOOKS
COOLER WITH A BETTER CHANCE FOR SNOW. IT HAS A VERY SIMILAR TRACK
TO THE WEEKEND STORM...HOWEVER...IT IS ALSO DRIER AND FASTER. WE
WILL LEAVE IT THERE AND TAKE THIS ONE SYSTEM AT A TIME.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1047 PM CST FRI DEC 11 2015
LOW SWATH OF CLOUDS HAS RETREATED JUST FAR ENOUGH...ALONG WITH
HIGH CLOUDS MOVING IN FROM THE S...SUCH THAT THE ERN 3 TAFS
/KMSP-KRNH-KEAU/ HAVE JUMPED UP TO VFR CONDS WITH CLOUDS ARND
SCT015 WHILE THE WRN 3 TAFS REMAIN UNDER LOWER MVFR TO IFR
CEILINGS. WITH A STRONG SLY SURGE OF MOISTURE MOVING INTO THE AREA
OVERNIGHT THRU TMRW...AM EXPECTING THE LOWER CLOUDS TO FILL BACK
IN SO WILL LOOK FOR ALL SITES TO HAVE IFR-OR-WORSE CEILINGS BY
DAYBREAK SAT MRNG. THE IFR CEILINGS WILL THEN REMAIN IN PLACE ALL
DAY SAT THRU SAT EVE AHEAD OF THE FIRST BATCH OF RAIN EXPECTED TO
REACH THE AREA TMRW EVE. HAVE STAGGERED THE START TIME OF THE -RA
FOR NOW BUT THIS MAY WELL NEED TO BE ADJUSTED SLIGHTLY IN LATER
TAF ISSUANCES. WINDS TO REMAIN OUT OF THE ENE IN THE 5-10 KT
RANGE.
KMSP...KMSP MANAGED TO FIND ITSELF IN THE CLEAR EARLIER THIS
EVENING BUT AM NOT EXPECTING THAT TO LAST BEYOND 09Z-10Z. AM
EXPECTING IFR CEILINGS TO RETURN BY DAYBREAK SAT MRNG AND REMAIN
THERE THROUGH AT LEAST TMRW EVE.
/OUTLOOK FOR KMSP/
SUN...IFR WITH PERIODS OF RA. WINDS NE TO N 10-15 KTS.
MON...MVFR/IFR. -RA/-SN POSSIBLE EARLY. WINDS NW 15-20 KTS.
TUE...VFR EARLY. MVFR/IFR WITH CHC -SN LATE. WINDS E 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
UPDATE...JPC
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...JPC
AREA FORECAST DISCUSSION
National Weather Service Kansas City/Pleasant Hill MO
257 PM CST SAT DEC 12 2015
.DISCUSSION...
Issued at 257 PM CST SAT DEC 12 2015
Very well defined temperature boundary draped across the forecast
area this afternoon. This boundary is running roughly from SW to NE
from KPNC to KDBQ. South of this boundary temperatures are in the
upper 60s to lower 70s, with dew points in the upper 50s to lower
60s. North of the boundary, temperatures are in the middle 40s to
lower 50s, with dew points in the 40s. The warm temperatures across
the area exist despite widespread cloud cover, which is in response
to good moisture transport north within the southerly low level
flow. Shameful the warm front likely won`t reach far enough north
for KCI to record the warm air, since today`s record high is 70
degrees, set on December 12, 1889. As it were, expect temperatures
to remain well above seasonal normals across the area, with the warm
sector along and south of I-70 generally remaining about 30 degrees
above normal mid-December values.
Biggest change in this forecast package deals with the timing of the
precipitation into the area. HRRR trends have indicated little in
the way of precipitation moving into the area prior to sunset, and
latest NAM (12z) forecast soundings show pretty poor quality
moisture moving into the area this afternoon. Forecast soundings,
while nicely saturated in the lower levels (stratus) have very dry
air entrapped in the mid levels. This dry air will take some time to
completely saturate. Have bumped back the timing of scattered
precipitation to after 00z, with more widespread rain perhaps
holding off until around 03z to 06z. Once the atmosphere properly
saturates tonight expect widespread rain to overtake the area.
Soundings showing deep saturation all the way to 400 mb as well as
very high PWAT`s (~1.5 to 1.75 inches) indicate very efficient rain
process akin to a tropical type air mass. Forecast anomalies
indicate the moisture quality of the atmosphere are good enough to
represent maximum values observed for mid-December, nearly 5
standard deviations above normal values. Given the impressive
moisture quality rain rates will be high. The progressive nature of
the mid level system will likely make the bulk of the precipitation
fall during a ~12 hour stretch Saturday night through Sunday
morning. By Sunday afternoon/evening the track of the mid level
system will push the mid level dry slot right through the heart of
the forecast area, which will limit rain amounts from KC up through
KIRK. Despite the "limited" amounts, still anticipating over an inch
of rain for the entire area, up to 2 inches, with some areas
reaching 2 to 3 inches. As the mid level trough moves through,
dragging the dry slot through western Missouri a cold front will
dive south/southeast bringing a cooling trend to the first part of
next week. NAM continues to indicate colder air in the lowest levels
in the post frontal deformation band associated with the trowal, and
even hints at accumulating snow for portions of NW Missouri. However
it remains the outlier for temperatures cold enough for snow
production and accumulation. Final forecast lows for Monday morning
in the middle to upper 30s in far NW Missouri put the final nail in
the coffin of any notion of accumulating snow anywhere in Missouri.
That being said, one could certainly infer from the cool air aloft
that some ice crystals could form with perhaps a few making it to
the surface.
As for the mode of rain showers on Saturday night. Forecast models
continue to indicate some very marginal instability, on the order of
a few hundred J/kg of MUCAPE through 09z. Given the marginal
instability it remains conceivable that there could be some embedded
thunderstorms within the stratiform rain. Deep layer shear on the
order of 40 to 50 kts will be enough to help any thunderstorm to
become strong. While widespread severe weather is not anticipated,
there is a chance that one or several of these thunderstorms could
produce some gusty winds and perhaps some small hail. Due to the
prolonged nature of the light to moderate rain it also remains
possible that several area rivers could see some minor/nuisance
flooding.
Expect the rain to linger through the first part of the day on
Monday and be out of the area by Monday afternoon/evening.
Thereafter the pattern goes dry for the foreseeable future, with the
exception of some very low end chances for precipitation (in the form
of very light rain and/or snow for Tuesday night. A much cooler
pattern then develops, much like this area is accustomed to seeing
in mid-December with highs in the 30s and 40s and lows in the 20s
and 30s.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1126 AM CST SAT DEC 12 2015
Still anticipating widespread light to moderate rain to move into the
area later this afternoon. Bumped back the timing a bit for the onset
of said precipitation as the atmosphere will take a bit longer to
saturate. In the meantime expect prevailing stratus, with a few
periods of light freezing rain and drizzle, with borderline MVFR/IFR
conditions. Once the rain sets in, likely between 00z and 03z, it
will be moderate to heavy at times, with perhaps a few embedded
thunderstorms. The lightning threat should wane around 06z, leaving
only prevailing moderate rain through the remainder of the forecast
period.
&&
.EAX Watches/Warnings/Advisories...
KS...NONE.
MO...NONE.
&&
$$
DISCUSSION...Leighton
AVIATION...Leighton
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1123 PM CST FRI DEC 11 2015
.UPDATE:
Issued at 937 PM CST Fri Dec 11 2015
Updated forecast to include areas of fog across the northern CWA
where visibility ranges from 1/4SM at IRK to 4SM at UIN. Have also
updated for latest temperature and dewpoint trends. Walked outside
a few minutes ago and everything is soaked as low level moisture
continues to increase and condense on the cooler ground.
CVKING
&&
.SHORT TERM: (Through Late Tonight)
Issued at 336 PM CST Fri Dec 11 2015
Forecast problem for tonight is sky cover and possibility of fog.
Low clouds have mostly cleared out of central Missouri, but are
hanging tough across eastern Missouri and much of southern and
central Illinois. Model guidance has been less than helpful so far
in forecasting these low clouds...though the HRRR has been the best
so far. HRRR has the low clouds continuing to push northeast this
evening, but high clouds will likely persist over the area. The net
effect for the public forecast will still be a mostly cloudy to
cloudy sky regardless of what the low clouds ultimately decide to
do. While there could be some fog tonight, boundary layer winds
look too strong to support truly dense fog...except possibly over
the eastern Ozarks. However, it`s more likely that low visibility
will be caused by low clouds which are forecast to redevelop over
the higher terrain. South-southwest flow combined with clouds will
keep lows well above normal tonight. MOS guidance in the low to mid
50s looks very reasonable.
Carney
.LONG TERM: (Saturday through Next Friday)
Issued at 336 PM CST Fri Dec 11 2015
(Saturday through Monday)
Operational models are showing a slightly slower motion of the upper
low toward the area over the weekend which will result in a slower
onset of the steadier showers on Saturday night and Sunday. Before
then, still expect chances of light rain to increase during the day
on Saturday as transport of moisture from the Gulf increases via
40kt low level jet. Then showers and scattered thunderstorms will
spread across the area on Saturday night and Sunday as strong
moisture convergence moves from west to east across the area
under enhanced ascent caused by negatively tilting mid level
trough. The rain will continue into Sunday night before ending
during the day Monday as the trough lifts out of the area.
While temperatures will cool off slightly over the weekend because
of the rain, they will remain above normal because of the warm
sector. There will not be much of diurnal swing because of the
clouds and rain.
(Tuesday through Friday)
The GFS and ECMWF are depicting similar solutions to yesterday with
an upper low moving from the southern Rockies into the Great Lakes
at midweek. Most of the dynamics look to be staying to the
northwest of our area with this system, and the most of the moisture
will be staying to the south, so precipitation will be limited. The
system will still pull a cold front through the area on Wednesday
with 850mb temperatures falling to around -10C on the ECMWF by
Friday behind it. This still confirms that temperatures will go
from well above normal on Tuesday to near mid December normals by
Friday.
Britt
&&
.AVIATION: (For the 06z TAFs through 06z Saturday Night)
Issued at 1113 PM CST Fri Dec 11 2015
Latest obs from UIN suggest that wrmfnt has lifted N of terminal.
If the fnt remains N of the terminal, expect VFR conditions to
persist thru sunrise. However, can not rule out the fnt dropping
back S. If this occurs, FG at terminal will be possible and
probably LIFR visbys or lower.
COU is expected to have MVFR cigs, with some FG possible, late
tonight into Sat morning. These cigs shud lift during the morning
and become VFR with a swly wind.
SUS/CPS...have added mention of LLWS. LLJ may diminish slightly
overnight, but is expected to be around 40 kts. If sites remain
decoupled, anticipate at least some FG to develop late tonight and
lift to ST after sunrise as a secondary sfc trof moves thru the
area.
Specifics for KSTL: Expect VFR conditions overnight with MVFR
clouds developing Sat morning and lifting thru the day. Winds will
remain sly to sswly until Sat eve when they back to ssely.
Tilly
&&
.CLIMATE:
Record max temps through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 70/1979 70/1991 73/1948
COU 73/1949 74/1889 75/1948
UIN 69/1949 67/1991 67/1948
Record hi lows through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 53/1965 55/1929 56/1889
COU 55/1965 46/1929 55/1889
UIN 55/1965 42/1991 50/1927
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...Dense Fog Advisory until 10 AM CST Saturday FOR Knox MO-Lewis MO-
Shelby MO.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
636 PM MST SUN DEC 13 2015
.UPDATE...
SNOW AND THE STRONGER WINDS HAVE ABATED IN UNION COUNTY THIS
EVENING...SO THE WINTER STORM WARNING WILL BE CANCELLED FOR THIS
LAST REMAINING ZONE. THE WATCH WILL CONTINUE FOR THE NORTHERN
MOUNTAINS FOR LATE MONDAY INTO TUESDAY WHEN THE NEXT STORM SYSTEM
WILL QUICKLY ARRIVE.
FOR TONIGHT...THERE IS STILL SOME CONCERN THAT PATCHES OF
FREEZING FOG COULD DEVELOP. THE HRRR AND RAP MODELS INDICATE THE
MIDDLE RIO GRANDE VALLEY AND SOME OF THE SHELTERED AND RELATIVELY
LOWER ELEVATIONS IN THE NORTH CENTRAL TO NORTHWEST PARTS OF NM
MIGHT BE FAVORED FOR NEAR-SURFACE SATURATION. DEWPOINTS DID NOT
SURGE UP AS HIGH AS MIGHT BE EXPECTED IN THIS REGION CONSIDERING
THIS AFTERNOON`S INSOLATION AND MELTING SNOW...SO CONFIDENCE IN
FOG DEVELOPMENT IS NOT ALL THAT HIGH. THUS...ONLY A MINIMAL
EXPANSION OF FOG WAS DRAWN IN FOR THESE AREAS. THESE ALTERATIONS
WILL NOT BE REFLECTED IN THE ZONE FORECAST PACKAGE...BUT ONLY IN
THE POINT AND CLICK WEB BASED FORECAST. THUS NO NEW UPDATED ZONE
FORECAST PACKAGE WILL BE SENT AT THIS TIME.
52
&&
.PREV DISCUSSION...506 PM MST SUN DEC 13 2015...
.AVIATION...
00Z TAF CYCLE
UPPER LOW CONTINUES TO PULL AWAY FROM NM WITH CLEARING OVR ERN NM
ALTHOUGH GUSTY NW WINDS TO AROUND 35KT WILL CONTINUE OVR FAR NE NM UNTIL
AROUND 04Z. HIGH CLOUDS WILL INCREASE FROM THE WEST THROUGH 12Z
AS ANOTHER UPPER LOW APPROACHES FROM THE GREAT BASIN. DESPITE
RECENT SNOWFALL...LOW LEVEL HUMIDITIES HAVE DRIED SOME SO NOT
ANTICIPATING WIDESPREAD LOW CLOUDS OR FOG BEFORE 12Z ALTHOUGH SOME
LOCALIZED MVFR TO IFR CIGS/VSBYS IN BR COULD DEVELOP ALONG THE
CENTRAL MT CHAIN.
&&
.PREV DISCUSSION...311 PM MST SUN DEC 13 2015...
.SYNOPSIS...
ANOTHER STORM WILL MOVE OVER NEW MEXICO MONDAY THROUGH TUESDAY. VERY
COLD AIR AND BREEZY CONDITIONS WILL FORCE WIND CHILL VALUES INTO THE
SINGLE DIGITS AND TEENS THROUGH WEDNESDAY. OVERNIGHT LOWS WILL BE
THE COLDEST OF THE SEASON WITH READINGS NEAR ZERO IN NORTHERN AND
WESTERN VALLEYS BY TUESDAY AND WEDNESDAY NIGHT. A HEAVY DOSE OF
DRY FLUFFY SNOWFALL IS POSSIBLE ON WEST FACING SLOPES OF THE
SANGRE DE CRISTO MOUNTAINS AND THE SAN JUANS MONDAY NIGHT AND
TUESDAY. HIGH TEMPERATURES WILL REMAIN VERY COLD THROUGH THURSDAY
BEFORE A SLOW WARMING TREND BEGINS LATE IN THE WEEK.
&&
.DISCUSSION...
BLIZZARD CONDITIONS ARE SLOWLY WINDING DOWN OVER UNION COUNTY WHERE
SEVERAL ROAD CLOSURES HAVE OCCURRED. VSBYS NEAR ONE QUARTER MILE FOR
MOST OF THE DAY WITH STRONG WINDS HAS LED TO EXTREMELY DANGEROUS
TRAVEL. THE ONE SAVING GRACE IS TEMPS ARE HOVERING NEAR FREEZING...
MAKING THE SNOWFALL AT LEAST A LITTLE STICKIER. NONETHELESS...WILL
STILL HIGHLIGHT BLOWING SNOW THROUGH TONIGHT AND POSSIBLY EXTEND
WARNING THROUGH THE EVENING...OR REPLACE WITH BLOWING SNOW ADVISORY.
THE BIG STORY OVER THE COMING DAYS WILL BE VERY COLD AIR SETTLING
INTO THE STATE BEHIND THE NEXT SYSTEM ARRIVING FROM THE NORTHWEST...
AS WELL AS A POTENTIALLY IMPRESSIVE WEST SLOPE SNOW EVENT FOR THE
SANGRE DE CRISTOS AND SAN JUANS. THE PACIFIC FRONT WILL ARRIVE FROM
WEST TO EAST MONDAY AND ALLOW ANY RAIN TO CHANGE TO SNOW WHILE TEMPS
TUMBLE. WINDS WILL ALSO BE GUSTY ALONG AND BEHIND THE FRONT. STRONG
COLD ADVECTION ON MOIST UNSTABLE WESTERLY FLOW WILL FORCE AN IDEAL
DENDRITIC GROWTH ZONE SMACK DAB OVER THE HIGH TERRAIN MONDAY NIGHT
TO TUESDAY. THE SPC HI RES WRF...THE LOCAL 5KM WRF...AND NAM218 ARE
SQUEEZING OUT GENEROUS QPF FOR SUCH A COLD LAYER...LEADING TO VERY
HIGH SNOW RATIOS AROUND 20:1. WILL HOIST A WATCH FOR THESE AREAS.
MAY ALSO SEE A FEW ADVISORIES IN ADJACENT LOWER TERRAIN AREAS.
OVERNIGHT LOWS BEHIND THIS SYSTEM WILL BE THE COLDEST OF THE SEASON
WITH LOTS OF NEAR ZERO TO LOW TEENS FOR CENTRAL AND WESTERN NM.
WINDS WILL ALSO MAKE IT FEEL BRUTAL. ONE MORE FAST MOVING WAVE IN NW
FLOW IS SHOWN TO MOVE OVER THE STATE THURSDAY BEFORE A SLOW WARMING
TREND DEVELOPS OVER THE WEEKEND.
GUYER
&&
.FIRE WEATHER...
AS THE FIRST IN A ONE TWO PUNCH OF UPPER LEVEL LOW PRESSURE SYSTEMS
EXITS THE AREA TO THE NE...STRONG WINDS WILL GRADUALLY WEAKEN ACROSS
NE NM THIS EVENING. HOWEVER...BREEZY TO WINDY CONDITIONS ARE
EXPECTED THROUGH TONIGHT ACROSS THE HIGH TERRAIN OF NORTHERN AND
CENTRAL NM...AS WELL AS THE REGION FROM CLINES CORNERS TO VAUGHN.
THERE WILL A BRIEF WEAKENING OF WINDS ALOFT THIS EVENING...BUT
SPEEDS WILL STRENGTHEN AGAIN TONIGHT THROUGH MONDAY AS ANOTHER JET
STREAK MOVES OVER THE AREA AROUND THE BASE OF OUR NEXT UPPER LEVEL
TROUGH. WITH ALL THE SNOW ON THE GROUND VERTICAL MIXING WILL BE
LIMITED MONDAY...RELEGATING STRONGER SOUTHWEST WINDS TO THE HIGH
TERRAIN. IT WILL BE LESS WINDY BUT STILL GUSTY AT LOWER
ELEVATIONS...ESPECIALLY FROM CLINES CORNERS TO GRAN QUIVIRA AND
BOSQUE DEL APACHE.
THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM IS FORECAST TO TRACK
EASTWARD ACROSS S CO MONDAY NIGHT AND TUESDAY. MODELS DEPICT A
DECENT TAP OF MOISTURE OFF THE PACIFIC WITH THIS STORM. AND...IT
WILL BE A COLD SYSTEM WHICH WILL SPREAD SNOW ACROSS MUCH OF
WESTERN...NORTHERN AND CENTRAL NM MONDAY AND MONDAY NIGHT.
THEN...DRIER VARIETY SNOW WILL PERSIST THROUGH AT LEAST TUESDAY IN
THE NORTHERN MOUNTAINS WITH SIGNIFICANT ACCUMULATION POSSIBLE THERE.
A PACIFIC COLD FRONT WILL CROSS FROM THE WEST MONDAY NIGHT SHIFTING
WINDS OUT OF THE W BY TUESDAY. A DECENT SURFACE PRESSURE GRADIENT
AROUND THE BASE OF A SURFACE LOW EXITING COLORADO...AND THE TAIL END
OF THE AFOREMENTIONED JET STREAK...SHOULD SET UP EASTERN AREAS FOR A
WINDY DAY ON TUESDAY WITH GUSTS IN THE 40 TO PERHAPS 50 MPH RANGE
AROUND AND S OF I-40.
NW FLOW ALOFT WILL TRACK AN ADDITIONAL UPPER LEVEL TROUGH ACROSS NE
NM THURSDAY...WITH LIGHT ADDITIONAL PRECIP POSSIBLE ACROSS THE
NORTHERN MOUNTAINS AND NE.
TEMPERATURE-WISE...AFTER A BRIEF REBOUND OF HIGHS ON
MONDAY...READINGS WILL PLUMMET AROUND 10 TO 19 DEGREES BELOW NORMAL
TUESDAY THROUGH THURSDAY. WIDESPREAD POOR VENTILATION IS EXPECTED
FROM THE RIO GRANDE VALLEY EASTWARD MONDAY...BUT WESTERN AREAS
SHOULD HAVE STRONG VENTILATION AS WINDS ALOFT STRENGTHEN FROM THE
WEST. THE PASSING UPPER LOW AND UPPER TROUGH WILL LEAD TO
VENTILATION IMPROVEMENT AREAWIDE TUESDAY AND THURSDAY...BUT
WIDESPREAD POOR VENTILATION IS EXPECTED IN THE WAKE OF COLD FRONTS
WEDNESDAY AND FRIDAY.
TEMPERATURES SHOULD REBOUND NICELY AS A RIDGE OF HIGH PRESSURE
CROSSES AT THE END OF THE WEEK...BUT TEMPERATURE INVERSIONS SHOULD
KEEP VENTILATION POOR FOR MANY AREAS INTO NEXT WEEKEND.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY AFTERNOON
FOR THE FOLLOWING ZONES... NMZ510-512>514.
&&
$$
52
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
923 PM CST SUN DEC 13 2015
.UPDATE...
ISSUED AT 917 PM CST SUN DEC 13 2015
TRIMMED DENSE FOG ADVISORY...LEAVING THE AREA OF GWINNER TO
LANGDON AND WEST BASICALLY. NOT SEEING MUCH EVIDENCE OF EASTWARD
EXPANSION...SO BELIEVE THAT TREND WILL CONTINUE AS PRESSURES FALL.
MOST FAVORABLE AREA FOR FOG WILL BE IN THE DEVILS LAKE BASIN WHERE
HIGH EXISTS AND WILL BE RETREATING NORTHWARD. DRIZZLE HAS BEEN
REPORTED ALSO IN PARTS OF THE RED RIVER VALLEY...WILL BE
MONITORING FOR FREEZING POTENTIAL.
UPDATE ISSUED AT 712 PM CST SUN DEC 13 2015
FORECAST LARGELY UNCHANGED WITH THIS UPDATE. ADDED PATCHY FREEZING
DRIZZLE TO FAR SE ND BASED ON REPORT. OTHERWISE...MAIN CONCERN
WILL BE EXTENT OF FOG OVER THE NEXT SEVERAL HOURS. OBSERVATIONS
HAVE INDICATED VISIBILITIES HAVE IMPROVED ACROSS THE I-29
CORRIDOR OVER THE PAST FEW HOURS. LATEST HRRR HAS AREA OF FOG
EXPANDING EASTWARD AGAIN. HOWEVER...WITH HIGH PRESSURE RIDGE AXIS
OVER DEVILS LAKE TO JAMESTOWN AND LOW PRESSURE MOVING INTO THE
AREA...THE GENERAL TREND OVER THE NEXT 12-18 HRS SHOULD BE FOR
IMPROVING CONDITIONS. SO WILL MONITOR TRENDS AND LATEST MODEL RUNS
AND CONSIDER TRIMMING ADVISORY IN THE NEXT COUPLE OF HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 235 PM CST SUN DEC 13 2015
MAIN FORECAST CHALLENGE IN THE VERY NEAR TERM WILL BE THE THICKER
FOG THAT CONTINUES OVER PORTIONS OF THE FA. HAVE A DENSE FOG
ADVISORY OUT FOR PORTIONS OF THE FA AND WILL LIKELY HAVE TO
CONTINUE IT INTO TONIGHT AS WELL. TEMP/DEW POINT SPREADS REMAIN
VERY TIGHT AND WINDS LOOK TO REMAIN LOW. HIGH TEMPS GET UP RIGHT
AROUND 32F AGAIN ON MONDAY. THIS TIME WIND SPEEDS MAY BE HIGH
ENOUGH TO MIX OUT THE FOG. HOWEVER AT THIS POINT DID LEAVE PATCHY
FOG MENTIONED. THESE WINDS DO LIGHTEN UP AGAIN MON NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 PM CST SUN DEC 13 2015
NEXT SYSTEM BEGINS TO MOVE TOWARD THE FA ON TUE...BUT WILL ONLY
MAINTAIN PCPN CHANCES INTO THE SW. SFC LOW TRACKS FROM SW MN ON
12Z WED TO WESTERN LAKE SUPERIOR BY 00Z THU. MODELS SEEM FAIRLY
CONSISTENT ON PUSHING A DECENT SWATH OF SNOW THROUGH MOST OF THE
FA DURING THIS TIME FRAME...WITH THE LEAST WEST OF THE KDVL
REGION. WIND SPEEDS ALSO LOOK PRETTY GUSTY AS WELL. THE STEADIER
SNOW LIFTS NORTH AND EAST OF THE FA WED NIGHT INTO THU NIGHT BUT
SOME GUSTY WINDS WILL REMAIN. THIS SHOULD LEAD TO SOME BLOWING AND
DRIFTING SNOW. WILL ISSUE A SPECIAL WEATHER STATEMENT TO
HIGHLIGHT THIS SYSTEM AND WILL WATCH AND SEE WHAT LATER RUNS HAVE
IN STORE.
FOR WED NIGHT THROUGH SUNDAY...THE POTENTIAL WINTER STORM WILL BE
WINDING DOWN WED NIGHT/THU. THE GFS MOVES THE STORM THROUGH A BIT
FASTER AND MOST OF THE ACCUMULATION WOULD BE DONE BY WED
NIGHT...WITH THE ECMWF A BIT SLOWER. WILL CONTINUE WITH THE ALLBLEND
SOLUTION. TEMPS WILL BE MUCH COOLER FOR FRI/SAT AND SHOULD BE BELOW
ZERO AT NIGHT GIVEN COLD AIRMASS AND FRESH SNOW. TEMPS SHOULD START
TO WARM BACK UP ABOVE NORMAL SUNDAY WITH UPPER RIDGING AND 850MB
TEMPS ABOVE 0C.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 554 PM CST SUN DEC 13 2015
CONCERNS REGARDING LATEST TAFS ISSUED FOCUS ON LOW CIGS AND VIS
OVER THE NEXT 24 HRS. VIS HAS IMPROVED AT MANY OF THE
SITES...HOWEVER CIGS REMAIN LOW. BELIEVE THERE WILL BE A
DETERIORATION OF CONDITIONS THIS EVENING BEFORE IMPROVEMENT LATE
TONIGHT OR TOMORROW. FOLLOWED THE LAV/GFS LAMP GUIDANCE FOR
GENERAL TRENDS. THE HRRR DOES HAVE VIS IMPROVING AT ALL SITES BUT
KDVL TONIGHT...BUT CIGS REMAIN LOW. WILL MONITOR CONDITIONS
CLOSELY THIS EVENING FOR TRENDS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 11 AM CST MONDAY FOR NDZ006-007-014-015-
024-026-028-029-038-049-052-054.
MN...NONE.
&&
$$
UPDATE...KNUTSVIG
SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
712 PM CST SUN DEC 13 2015
.UPDATE...
ISSUED AT 712 PM CST SUN DEC 13 2015
FORECAST LARGELY UNCHANGED WITH THIS UPDATE. ADDED PATCHY FREEZING
DRIZZLE TO FAR SE ND BASED ON REPORT. OTHERWISE...MAIN CONCERN
WILL BE EXTENT OF FOG OVER THE NEXT SEVERAL HOURS. OBSERVATIONS
HAVE INDICATED VISIBILITIES HAVE IMPROVED ACROSS THE I-29
CORRIDOR OVER THE PAST FEW HOURS. LATEST HRRR HAS AREA OF FOG
EXPANDING EASTWARD AGAIN. HOWEVER...WITH HIGH PRESSURE RIDGE AXIS
OVER DEVILS LAKE TO JAMESTOWN AND LOW PRESSURE MOVING INTO THE
AREA...THE GENERAL TREND OVER THE NEXT 12-18 HRS SHOULD BE FOR
IMPROVING CONDITIONS. SO WILL MONITOR TRENDS AND LATEST MODEL RUNS
AND CONSIDER TRIMMING ADVISORY IN THE NEXT COUPLE OF HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 235 PM CST SUN DEC 13 2015
MAIN FORECAST CHALLENGE IN THE VERY NEAR TERM WILL BE THE THICKER
FOG THAT CONTINUES OVER PORTIONS OF THE FA. HAVE A DENSE FOG
ADVISORY OUT FOR PORTIONS OF THE FA AND WILL LIKELY HAVE TO
CONTINUE IT INTO TONIGHT AS WELL. TEMP/DEW POINT SPREADS REMAIN
VERY TIGHT AND WINDS LOOK TO REMAIN LOW. HIGH TEMPS GET UP RIGHT
AROUND 32F AGAIN ON MONDAY. THIS TIME WIND SPEEDS MAY BE HIGH
ENOUGH TO MIX OUT THE FOG. HOWEVER AT THIS POINT DID LEAVE PATCHY
FOG MENTIONED. THESE WINDS DO LIGHTEN UP AGAIN MON NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 PM CST SUN DEC 13 2015
NEXT SYSTEM BEGINS TO MOVE TOWARD THE FA ON TUE...BUT WILL ONLY
MAINTAIN PCPN CHANCES INTO THE SW. SFC LOW TRACKS FROM SW MN ON
12Z WED TO WESTERN LAKE SUPERIOR BY 00Z THU. MODELS SEEM FAIRLY
CONSISTENT ON PUSHING A DECENT SWATH OF SNOW THROUGH MOST OF THE
FA DURING THIS TIME FRAME...WITH THE LEAST WEST OF THE KDVL
REGION. WIND SPEEDS ALSO LOOK PRETTY GUSTY AS WELL. THE STEADIER
SNOW LIFTS NORTH AND EAST OF THE FA WED NIGHT INTO THU NIGHT BUT
SOME GUSTY WINDS WILL REMAIN. THIS SHOULD LEAD TO SOME BLOWING AND
DRIFTING SNOW. WILL ISSUE A SPECIAL WEATHER STATEMENT TO
HIGHLIGHT THIS SYSTEM AND WILL WATCH AND SEE WHAT LATER RUNS HAVE
IN STORE.
FOR WED NIGHT THROUGH SUNDAY...THE POTENTIAL WINTER STORM WILL BE
WINDING DOWN WED NIGHT/THU. THE GFS MOVES THE STORM THROUGH A BIT
FASTER AND MOST OF THE ACCUMULATION WOULD BE DONE BY WED
NIGHT...WITH THE ECMWF A BIT SLOWER. WILL CONTINUE WITH THE ALLBLEND
SOLUTION. TEMPS WILL BE MUCH COOLER FOR FRI/SAT AND SHOULD BE BELOW
ZERO AT NIGHT GIVEN COLD AIRMASS AND FRESH SNOW. TEMPS SHOULD START
TO WARM BACK UP ABOVE NORMAL SUNDAY WITH UPPER RIDGING AND 850MB
TEMPS ABOVE 0C.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 554 PM CST SUN DEC 13 2015
CONCERNS REGARDING LATEST TAFS ISSUED FOCUS ON LOW CIGS AND VIS
OVER THE NEXT 24 HRS. VIS HAS IMPROVED AT MANY OF THE
SITES...HOWEVER CIGS REMAIN LOW. BELIEVE THERE WILL BE A
DETERIORATION OF CONDITIONS THIS EVENING BEFORE IMPROVEMENT LATE
TONIGHT OR TOMORROW. FOLLOWED THE LAV/GFS LAMP GUIDANCE FOR
GENERAL TRENDS. THE HRRR DOES HAVE VIS IMPROVING AT ALL SITES BUT
KDVL TONIGHT...BUT CIGS REMAIN LOW. WILL MONITOR CONDITIONS
CLOSELY THIS EVENING FOR TRENDS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 11 AM CST MONDAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052-054.
MN...DENSE FOG ADVISORY UNTIL 11 AM CST MONDAY FOR MNZ001>004-007.
&&
$$
UPDATE...KNUTSVIG
SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
554 PM CST SUN DEC 13 2015
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 235 PM CST SUN DEC 13 2015
MAIN FORECAST CHALLENGE IN THE VERY NEAR TERM WILL BE THE THICKER
FOG THAT CONTINUES OVER PORTIONS OF THE FA. HAVE A DENSE FOG
ADVISORY OUT FOR PORTIONS OF THE FA AND WILL LIKELY HAVE TO
CONTINUE IT INTO TONIGHT AS WELL. TEMP/DEW POINT SPREADS REMAIN
VERY TIGHT AND WINDS LOOK TO REMAIN LOW. HIGH TEMPS GET UP RIGHT
AROUND 32F AGAIN ON MONDAY. THIS TIME WIND SPEEDS MAY BE HIGH
ENOUGH TO MIX OUT THE FOG. HOWEVER AT THIS POINT DID LEAVE PATCHY
FOG MENTIONED. THESE WINDS DO LIGHTEN UP AGAIN MON NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 PM CST SUN DEC 13 2015
NEXT SYSTEM BEGINS TO MOVE TOWARD THE FA ON TUE...BUT WILL ONLY
MAINTAIN PCPN CHANCES INTO THE SW. SFC LOW TRACKS FROM SW MN ON
12Z WED TO WESTERN LAKE SUPERIOR BY 00Z THU. MODELS SEEM FAIRLY
CONSISTENT ON PUSHING A DECENT SWATH OF SNOW THROUGH MOST OF THE
FA DURING THIS TIME FRAME...WITH THE LEAST WEST OF THE KDVL
REGION. WIND SPEEDS ALSO LOOK PRETTY GUSTY AS WELL. THE STEADIER
SNOW LIFTS NORTH AND EAST OF THE FA WED NIGHT INTO THU NIGHT BUT
SOME GUSTY WINDS WILL REMAIN. THIS SHOULD LEAD TO SOME BLOWING AND
DRIFTING SNOW. WILL ISSUE A SPECIAL WEATHER STATEMENT TO
HIGHLIGHT THIS SYSTEM AND WILL WATCH AND SEE WHAT LATER RUNS HAVE
IN STORE.
FOR WED NIGHT THROUGH SUNDAY...THE POTENTIAL WINTER STORM WILL BE
WINDING DOWN WED NIGHT/THU. THE GFS MOVES THE STORM THROUGH A BIT
FASTER AND MOST OF THE ACCUMULATION WOULD BE DONE BY WED
NIGHT...WITH THE ECMWF A BIT SLOWER. WILL CONTINUE WITH THE ALLBLEND
SOLUTION. TEMPS WILL BE MUCH COOLER FOR FRI/SAT AND SHOULD BE BELOW
ZERO AT NIGHT GIVEN COLD AIRMASS AND FRESH SNOW. TEMPS SHOULD START
TO WARM BACK UP ABOVE NORMAL SUNDAY WITH UPPER RIDGING AND 850MB
TEMPS ABOVE 0C.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 554 PM CST SUN DEC 13 2015
CONCERNS REGARDING LATEST TAFS ISSUED FOCUS ON LOW CIGS AND VIS
OVER THE NEXT 24 HRS. VIS HAS IMPROVED AT MANY OF THE
SITES...HOWEVER CIGS REMAIN LOW. BELIEVE THERE WILL BE A
DETERIORATION OF CONDITIONS THIS EVENING BEFORE IMPROVEMENT LATE
TONIGHT OR TOMORROW. FOLLOWED THE LAV/GFS LAMP GUIDANCE FOR
GENERAL TRENDS. THE HRRR DOES HAVE VIS IMPROVING AT ALL SITES BUT
KDVL TONIGHT...BUT CIGS REMAIN LOW. WILL MONITOR CONDITIONS
CLOSELY THIS EVENING FOR TRENDS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 11 AM CST MONDAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052-054.
MN...DENSE FOG ADVISORY UNTIL 11 AM CST MONDAY FOR MNZ001>004-007.
&&
$$
SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS BISMARCK ND
345 PM CST SAT DEC 12 2015
.UPDATE...
ISSUED AT 341 PM CST SAT DEC 12 2015
GIVEN WEBCAM AND SURFACE OBSERVATION TRENDS ACROSS NORTHWEST AND
PORTIONS OF CENTRAL NORTH DAKOTA THROUGH 2130 UTC...AND THE 18
UTC NAM NEST AND 20 UTC HRRR VISIBILITY FORECASTS SUGGESTING DENSE
FOG WILL CONTINUE THROUGH THE NIGHT FOR THESE LOCATIONS...ISSUED A
DENSE FOG ADVISORY THROUGH 12 UTC SUNDAY FOR THE AFOREMENTIONED
PORTIONS OF THE CWA. FREEZING TEMPERATURES MAY RESULT IN A THIN
LAYER OF ICE FORMING ON ROADS AND SIDEWALKS FROM THE FOG. WILL
MONITOR FOR A POSSIBLE EXPANSION OF THE ADVISORY INTO THE EVENING
WITH STRATUS BUILD DOWN OVER THE PARTIALLY MELTED FRESH SNOW PACK.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 254 PM CST SAT DEC 12 2015
CONCERNS THIS FORECAST INVOLVE FOG. ALSO LOW CLOUDS IMPACTING
TEMPERATURES. FREEZING DRIZZLE CHANCES WERE EXAMINED BUT ENOUGH
UNCERTAINTY SO DID NOT INCLUDE AT THIS TIME.
AT 2 PM CST...A SHALLOW COOL AIRMASS ASSOCIATED WITH HIGH
PRESSURE CENTERED IN CENTRAL MANT/SASK SOUTH THROUGH NORTH DAKOTA.
THE BOUNDARY LAYER IS BEING KEPT COOL AND MOIST FROM THE RECENT
SNOW AND THIS HAS RESULTED IN A PERSISTENT STRATUS AREA EXTENDING
OVER MOST OF CENTRAL AND NORTHERN NORTH DAKOTA SATURDAY AFTERNOON.
TONIGHT THE RAP/HRRR MODEL INDICATES A LOW LEVEL SOUTHEAST WIND
FLOW. SOUTHEAST FLOW IS LESS PREFERABLE THAN EAST OR NORTHEAST
FLOW FOR TERRAIN INDUCED LOW LEVEL VERTICAL MOTION WITHIN THE
NEARLY SATURATED STRATUS ENVIRONMENT OVER WEST AND CENTRAL NORTH
DAKOTA. WHILE THERE SHOULD BE SUFFICIENT MOISTURE FOR FOG
FORMATION...SUFFICIENT UPSLOPE FLOW MAY NOT EXIST TO GENERATE
FREEZING DRIZZLE SO DECIDED TO WAIT.
WILL CONTINUE LITTLE CHANGE IN TEMPERATURES WHERE STRATUS
PERSISTS ACROSS THE NORTH AND CENTRAL WITH THE SOUTHWEST SEEING
SOME DIURNAL RANGE AS THEY ARE LARGELY OUT OF THE LOW LEVEL
STRATUS.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 254 PM CST SAT DEC 12 2015
A WEAK SURFACE AND UPPER LEVEL PATTERN HIGHLIGHTS THE BEGINNING OF
THE EXTENDED PERIOD. THEN A BRUSH WITH A MID LATITUDE CYCLONE MID
WEEK FOLLOWED BY MOSTLY DRY AND SEASONABLY COOL WEATHER.
SUNDAY NIGHT A SOUTHERN PLAINS STORM SYSTEM IS FORECAST TO BE
CENTERED OVER KANSAS/OKLAHOMA...WHICH IS FORECAST TO MOVE NORTHEAST
INTO THE GREAT LAKES REGION BY MONDAY EVENING. THE TRACK OF THIS
SYSTEM WOULD LEAVE CENTRAL NORTH DAKOTA IN THE WEAK UPPER LEVEL FLOW
WITH SURFACE STRATUS-TYPE CLOUDS. WITH UPPER LEVEL CLOUDS HAVING
EXITED TO THE EAST...SOME LINGERING STRATUS WITH ISOLATED DRIZZLE
ARE POSSIBLE MONDAY EVENING. SURFACE TEMPERATURES IN THE 20S WOULD
RESULT IN SOME ISOLATED AREAS OF FREEZING DRIZZLE. BUFKIT SOUNDINGS
ALSO SUPPORT THIS...SO KEPT A SLIGHT CHANCE MENTION.
ATTENTION THEN TURNS TO THE NEXT UPPER LEVEL TROUGH SYSTEM WHICH IS
FORECAST TO BE OVER THE WEST COAST SUNDAY EVENING. THE SYSTEM
DEEPENS AND TRACKS EAST OVER THE ROCKIES...WITH THE LEADING EDGE OF
THE ASSOCIATED UPPER LEVEL ENERGY MOVING OVER THE FRONT RANGE ON
MONDAY. THE MODELS DEPICT THE STORM CENTERED OVER COLORADO/KANSAS BY
DAYBREAK TUESDAY...AND MOVING NORTHEAST TO THE SD/MN/NE/IA BORDER BY
DAYBREAK WEDNESDAY...AND NORTH OF LAKE SUPERIOR BY DAYBREAK
THURSDAY. THIS TRACK WOULD KEEP THE BULK OF SNOW FOR THIS SYSTEM TO
THE SOUTH AND EAST OF NORTH DAKOTA.
THIS TRACK SUGGESTS THE BETTER CHANCES OF MODERATE SNOW
ACCUMULATIONS ACROSS THE SOUTHERN HALF OF THE STATE OVER A PERIOD
FROM MONDAY NIGHT THROUGH WEDNESDAY...WITH ONLY LIGHT AMOUNTS
POSSIBLE NORTH. LIGHT SNOW WOULD BEGIN MONDAY NIGHT IN THE WESTERN
COUNTIES...THEN OVER MUCH OF THE STATE ON TUESDAY AND TUESDAY
NIGHT...AND LINGERING MAINLY OVER THE EAST HALF OF THE STATE ON
WEDNESDAY.
COLD AIR GETS PULLED INTO THE REGION BEHIND THE EXITING MID WEEK
SYSTEM...BRINGING TEMPERATURES DOWN TO SEASONABLY COOL READINGS
WITH HIGHS IN THE 20S AND LOWS IN THE SINGLE DIGITS AS WE MOVE TO
THE END OF THE WORK WEEK. LITTLE SIGNIFICANT PRECIPITATION IS
EXPECTED BEYOND THE MONDAY NIGHT - WEDNESDAY SYSTEM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY)
ISSUED AT 341 PM CST SAT DEC 12 2015
SHALLOW COOL AIRMASS OVER A FRESH SNOW PACK WILL RESULT IN
WIDESPREAD IFR TO LOW IFR CONDITIONS DUE TO LOW CEILINGS AND AREAS
OF FOG.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 6 AM CST SUNDAY FOR NDZ001-002-009-010-
017>019-021.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...JV
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1205 AM CST SAT DEC 12 2015
.UPDATE...
ISSUED AT 1205 AM CST SAT DEC 12 2015
THE LATEST WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH NOW LIFTING
TO THE NORTHERN BORDER AND SLOWLY SHIFTING INTO SOUTHERN CANADA.
LOCAL RADAR AND SURFACE OBSERVATIONS CONTINUE TO ADVERTISE LIGHT
SNOW MAINLY NORTH OF HIGHWAY 2...WITH LIGHT FREEZING DRIZZLE FROM
TIOGA INTO WATFORD CITY. THE 00Z NAM 4KM BUFKIT SOUNDINGS AT
WILLISTON AND WATFORD CITY SHOW ENOUGH VERTICAL MOTION WITHIN THE
SUPERCOOLED WATER DROPLET SPECTRUM PORTION OF THE SOUNDING FOR
POSSIBLE LIGHT FREEZING DRIZZLE...AND WILL MAINTAIN THAT IN THE
FORECAST AND SPS/SPECIAL WEATHER STATEMENT THAT WAS ISSUED EARLIER.
THIS HAS SUPPORT FROM CURRENT/PREVIOUS OBSERVATIONS AND LATEST
WEBCAMS AS WELL AS THE BUFKIT SOUNDINGS THROUGH 15Z SATURDAY. THE
FORECAST REMAINS ON TRACK WITH LOW CLOUDS DOMINATING ALL BUT THE FAR
SOUTHWEST OVERNIGHT INTO SATURDAY...WHICH WILL REMAIN MOSTLY CLEAR
TO PARTLY CLOUDY.
UPDATE ISSUED AT 933 PM CST FRI DEC 11 2015
MAIN CHANGE FOR LATE EVENING UPDATE WAS TO ADJUST BACK EDGE OF
SNOW A BIT OVER THE NORTH. OTHERWISE...REMAINDER OF FORECAST
REMAINS GOOD WITH THE POSSIBILITY OF FOG AND FREEZING
DRIZZLE...WITH SOME VERY LIGHT FREEZING DRIZZLE CURRENTLY BEING
OBSERVED AT NWS BISMARCK.
UPDATE ISSUED AT 757 PM CST FRI DEC 11 2015
HAVE SENT OUT A QUICK UPDATE TO ADD PATCHY FREEZING DRIZZLE TO THE
FORECAST OVER MUCH OF THE AREA. SOME LIGHT DRIZZLE STARTED AT THE
OFFICE WITHIN THE PAST HOUR. THIS IS SUPPORTED IN LATEST MODEL
RUN FORECAST SOUNDINGS SHOWING LACK OF ICE CRYSTALS IN SHALLOWER
CLOUD LAYER AS AREA OF SNOW EXITS TO THE NORTHEAST. UPDATES HAVE
BEEN SENT.
UPDATE ISSUED AT 618 PM CST FRI DEC 11 2015
SNOW CONTINUES TO GRADUALLY DIMINISH OVER THE AREA WITH THE BACK
EDGE RUNNING ALONG AND NEAR HIGHWAY 52. THIS TREND WILL CONTINUE
THROUGH THIS EVENING AS UPPER LOW/TROUGH CONTINUES TO LIFT TO THE
NORTH-NORTHEAST. WITH THE FRESH SNOW AND PLENTY OF LOW LEVEL
MOISTURE IN PLACE HAVE BROADENED OUT THE POSSIBILITY OF FOG THIS
EVENING AND OVERNIGHT. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
LATEST RADAR LOOPS HAVE THE BACK EDGE OF THE PRECIPITATION
APPROACHING A NEW SALEM TO BEULAH LINE. EXPECT THE SNOW TO END
WEST OF THE MISSOURI RIVER BY 4 PM. RADAR LOOPS ALSO SHOW THE
SYSTEM MAY BE LIFTING NORTH A BIT FASTER NOW SO THE SNOW WILL
PROGRESSIVELY END THIS EVENING NORTH. EXPECT STORM TOTALS 2 TO 3
INCHES ACROSS CENTRAL NORTH DAKOTA AND 1 TO 2 INCHES NORTH.
ISOLATED 4 INCH AMOUNTS ARE POSSIBLE SOUTH CENTRAL SUCH AS
BISMARCK.
TONIGHT WITH LOW LEVEL MOISTURE IN PLACE WILL SEE CLOUDS ALL BUT
THE FAR SOUTHWEST WHERE A SOUTHWEST WIND COMPONENT AT H925-850 MAY
ERODE CLOUD DECK A BIT. OTHERWISE CLOUDY. BASED ON THE HRRR KEPT
SOME FOG IN AFTER MIDNIGHT THROUGH SATURDAY MORNING WEST CENTRAL
AND SOUTH.
ON SATURDAY WILL DONT SEE ANYTHING THAT WILL CLEAR CLOUDS SO
CLOUDY EXCEPT FOR THE FAR SOUTHWEST. HIGHS WILL BE LIMITED TO THE
LOWER 30S EXCEPT MID TO UPPER 30S SOUTHWEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
SATURDAY NIGHT A LONGWAVE TROUGH IS WELL ESTABLISHED OVER THE
ROCKIES TO 4-CORNERS AREA. SHORTWAVE ENERGY MOVING NORTHEASTWARD
UPSTREAM OF THE TROUGH GLANCES THE JAMES RIVER VALLEY SATURDAY NIGHT
INTO SUNDAY MORNING. AREAS SOUTH OF JAMESTOWN COULD RECEIVE 1/2 INCH
TO AN INCH OF SNOW.
ATTENTION THEN TURNS TO THE NEXT STORM SYSTEM MOVING EAST ACROSS THE
ROCKIES. ON SUNDAY ANOTHER LONGWAVE TROUGH MOVES INTO THE WEST COAST
AND DIGS SOUTH TOWARDS CALIFORNIA. THE SYSTEM CONTINUES TO DEEPEN AS
IT MOVES ACROSS THE ROCKIES SUNDAY NIGHT AND MONDAY. UNCERTAINTIES
CONTINUE REGARDING PLACEMENT/TIMING OF THIS SYSTEM...BUT MODEL
CONSENSUS WOULD SUGGEST THE LEADING EDGE OF SHORTWAVE ENERGY AND
MOISTURE REACHING THE WESTERN DAKOTAS MONDAY AFTERNOON/EVENING. THE
MODELS DEVELOP THE STORM SYSTEM SUCH THAT THE TRACK OF THE MID-LEVEL
LOW MOVES FROM COLORADO ACROSS THE CENTRAL PLAINS TO EASTERN SOUTH
DAKOTA BY TUESDAY AFTERNOON AND INTO MINNESOTA TUESDAY NIGHT. THIS
LATEST RUN OF THE MODELS SUGGESTS SOUTHERN NORTH DAKOTA COULD
RECEIVE MODERATE SNOW AMOUNTS WITH LIGHT AMOUNTS IN THE NORTHWEST
AND NORTH CENTRAL...AND THIS OCCURRING OVER A PERIOD FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT/WEDNESDAY MORNING. THIS TRACK WOULD
SUGGEST THAT AREAS SOUTH AND EAST OF OUR AREA WOULD RECEIVE THE BULK
OF PRECIPITATION WITH THIS SYSTEM.
ANOTHER SHORTWAVE DIVES SOUTHEAST OUT OF ALBERTA/SASKATCHEWAN
WEDNESDAY/THURSDAY...BUT WITH MUCH LESS MOISTURE AND ONLY SLIGHT
CHANCES OF LIGHT SNOW/FLURRIES.
A COOLING TREND THROUGH THE LONG TERM...WITH SEASONABLE TEMPERATURES
EXPECTED BY THE MIDDLE AND END OF NEXT WEEK...WITH HIGHS IN THE 20S
AND LOWS IN THE SINGLE DIGITS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1205 AM CST SAT DEC 12 2015
ALL TERMINALS EXCEPT KDIK WILL REMAIN IN A MVFR/IFR CIG STATUS THROUGH
THE TAF PERIOD. EXPECT POCKETS OF LIGHT FREEZING DRIZZLE AT KISN
THROUGH 15Z SATURDAY. OTHERWISE VCFG WILL ACCOMPANY THE LOW
CLOUDS...WITH PERIODIC MVFR TO IFR VSBYS FAVORING KMOT/KJMS
THROUGH SATURDAY MORNING. KDIK WILL REMAIN ON THE FRINGE OF MVFR
CIGS/VSBYS...AND WILL BE MONITORED CLOSELY FOR ANY CHANGES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KS
SHORT TERM...WAA
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
910 PM EST SUN DEC 13 2015
.SYNOPSIS...
A COLD FRONT NEAR THE MISSISSIPPI RIVER WILL CROSS THE
REGION ON MONDAY AS STRONG LOW PRESSURE MOVES ACROSS THE CENTRAL
GREAT LAKES. HIGH PRESSURE WILL BUILD OVER THE AREA FROM THE SOUTH
TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE
REGION ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/... THE CLOUDS ARE HELPING TO
KEEP THE TEMPS FROM DROPPING TOO MUCH. STILL SOME PLACES HAVE
ALREADY GOTTEN WITHING A DEGREE OR TWO OF THE FORECAST LOW. WILL
INCH THESE SPOTS DOWN ANOTHER DEGREE OR SO TO ADD MORE OF A BUFFER.
A SPRINKLE COULD CLIP THE NW COUNTIES BUT THE HRRR AND RAP ARE
KEEPING MEASURABLE PRECIP OUT OF THE CWA THRU 12Z. BORDERING POPS
ARE SO HIGH...DON`T HAVE MUCH TO WORK WITH SO WILL RELUCTANTLY LEAVE
POP AS IS. AS THE LOW LEVEL JET INCREASES...WINDS WILL START TO PICK
UP TOWARD THE END OF THE NIGHT AND MAY BE GUSTING 20 TO 25 MPH IN
PARTS OF THE WEST AND ALONG THE LAKESHORE BY DAYBREAK.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE MODELS REMAIN IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AS
FAR AS THE MAIN SYNOPTIC FEATURES ARE CONCERNED. RAIN IS EXPECTED
TO RAPIDLY SPREAD ACROSS THE FORECAST AREA TOMORROW MORNING AHEAD
OF THE FRONT. THE FRONT WILL BE EAST OF THE AREA BY MID AFTERNOON.
A DRY SLOT BEHIND WILL SWING INTO THE AREA FROM THE SOUTHWEST
DURING THE AFTERNOON SO THERE MAY BE A DRY PERIOD FOR A FEW HOURS.
WRAP AROUND MOISTURE WILL INCREASE LATER IN THE DAY AND SOME MORE
LIGHT PRECIP IS POSSIBLE DURING THE EVENING BEFORE THE RAIN ENDS
ALTOGETHER OVERNIGHT. HIGH PRESSURE WILL RETURN FOR TUESDAY AND
TUESDAY NIGHT. IT WILL BE TOUGH TO SCOUR OUT THE LOW LEVEL
MOISTURE BUT AT LEAST SOME PARTIAL SUNSHINE IS LIKELY ALL AREAS.
HAVE CONTINUED THE TREND OF SLOWING DOWN THE NEXT SYSTEM AS WELL.
PRECIP CHANCES SHOULD HOLD OFF TILL LATE WEDNESDAY IN THE WEST AND
WEDNESDAY NIGHT ELSEWHERE. MOISTURE LOOKS SOMEWHAT LIMITED SO NO
MORE THAN CHANCE POPS NEEDED. THE SURFACE COLD FRONT RESPONSIBLE
FOR THE PRECIP WILL OVER THE AREA AT 12Z THURSDAY. UNBELIEVABLY
THERE WILL BE NO PRECIP TYPE CONCERNS WITH ALL RAIN EXPECTED.
HAVE USED A BLEND OF GUIDANCE TEMPS DURING THE PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
LITTLE CHANGE IN THE EXTENDED FORECAST. NEXT STRONG COLD FRONT
MOVES ACROSS THE FORECAST AREA THURSDAY MORNING...USHERING MORE
SEASONAL CONDITIONS. MODELS ARE SIMILAR BUT GFS CONTINUES TO BE A
LITTLE FASTER THAN THE ECMWF. PROBABLY A BREAK IN THE PRECIP
THURSDAY AFTERNOON AND EVENING. COULD SEE A LITTLE LAKE EFFECT IN
THE EAST FRIDAY AS THE 850MB TEMPS DIP TO -10C. BEST CHANCE FOR
LAKE ENHANCED SNOW SHOWERS FRIDAY EVENING INTO THE OVERNIGHT WITH
SECONDARY SHOT OF COLD AIR. BY 12Z SATURDAY THE 850MB TEMPS
PLUNGE TO -12C TO -14C. SO FAR OUT WILL JUST GO WITH CHANCE POPS
HOWEVER.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
VFR CONDITIONS EXPECTED THROUGH AT LEAST 12Z THEN LOWER
CEILINGS/VSBYS ARRIVING WITH A BAND OF RAIN ALONG A COLD FRONT
SWEEPING WEST TO EAST. RAIN WILL SPREAD INTO TOL/FDY BETWEEN 12-
14Z...CLE TOWARDS 16Z AND ERI BY 20Z. CONDITIONS WILL PRIMARILY BE
MVFR IN THE RAIN BUT CAN NOT RULE OUT BRIEF IFR WINDOW. A 50 KNOT
JET NEAR 2500 FEET WILL SPREAD ACROSS NORTHWEST AND NORTH CENTRAL
OHIO BETWEEN 08-15Z. STARTED TO INCREASE SURFACE WINDS WITH GUSTS
TO AROUND 20 KNOTS AS THE GRADIENT TIGHTENS UP AT THE SAME TIME SO
DID NOT INCLUDE LLWS IN MOST OF THE TERMINALS. THE EXCEPTION IS
CAK WHERE SURFACE WINDS MAY NOT BE GUSTING AT THAT TIME. AMENDMENTS
MAY BE NEEDED BASED ON CONDITIONS. WINDS WILL SHIFT TO SOUTHWEST
AND INCREASE BEHIND THE FRONT DURING THE AFTERNOON.
OUTLOOK...NON VFR MONDAY IN -SHRA...LINGERING INTO TUESDAY ACROSS
NORTHEAST OH AND NORTHWEST PA. NON-VFR PROBABLE WEDNESDAY NIGHT
INTO THURSDAY IN -SHRA.
&&
.MARINE...
SOUTH FLOW OVER THE LAKE WILL INCREASE OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT...BUT SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. A SMALL CRAFT ADVISORY WILL BE NEEDED MONDAY AS A
STRONG COLD PUSHES ACROSS THE LAKE. THERE STILL IS A SMALL CHANCE
OF A PERIOD OF SUSTAINED GALE FORCE WINDS BUT NOT ENOUGH TO RAISE A
GALE WATCH. WINDS DIMINISH FROM THE WEST TUESDAY AFTERNOON AS HIGH
PRESSURE MOVES ACROSS THE LOWER LAKES. WINDS BACK TO THE SOUTH
WEDNESDAY AHEAD OF NEXT SYSTEM THAT WILL MOVE ACROSS THE LAKE ON
THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...ADAMS/KUBINA
SHORT TERM...KUBINA
LONG TERM...DJB
AVIATION...KEC
MARINE...DJB
AREA FORECAST DISCUSSION
NWS NORMAN OK
313 PM CST SAT DEC 12 2015
.DISCUSSION...
STRONG TO SEVERE THUNDERSTORMS AS WELL AS HEAVY RAINFALL AND
FLOODING TONIGHT THROUGH SUNDAY MORNING ARE THE MAIN CONCERNS.
ISSUED A FLASH FLOOD WATCH FOR BRYAN AND ATOKA COUNTIES THROUGH
NOON SUNDAY WHERE CONFIDENCE OF WIDESPREAD 2 TO 4 INCHES OF
RAINFALL IN THESE AREAS ARE RATHER HIGH DUE TO ROUNDS OF SHOWERS
AND STORMS.
THROUGH 9 PM TONIGHT...THINK SOME SHOWERS AND THUNDERSTORMS WILL
FORM OVER THE AREA...PARTICULARLY IN BRYAN AND ATOKA COUNTIES.
CAPPING MAY LIMIT STORM FORMATION. SEVERE POTENTIAL REMAINS LOW
DURING THIS TIME FRAME. SOME MODELS INCLUDING THE HRRR SUGGESTED
THAT A FEW STORMS MAY FORM IN WESTERN OKLAHOMA AND WESTERN NORTH
TEXAS DURING THIS TIME FRAME...BUT DOUBT THIS WILL OCCUR DUE TO
SUFFICIENT CAPPING. IF SURFACE BASED STORMS COULD FORM IN WESTERN
OKLAHOMA AND WESTERN NORTH TEXAS...THEY WOULD BE SUPERCELLULAR
WITH SEVERE HAIL UP TO HALF DOLLARS AS THE MAIN HAZARD AND A VERY
LOW CHANCE FOR TORNADOES BASED ON STRONG LOW LEVEL SHEAR. THE
GREATER CHANCES FOR STORMS WILL BE IN WEST TEXAS INCLUDING THE
TEXAS PANHANDLE BEFORE 9 PM WHERE STRONGEST FORCING AND MID LEVEL
TEMPERATURE FALLS WILL ALLOW FOR THE CAP TO BREAK.
THROUGH THIS EVENING...FOG MAY BE RATHER DENSE NEAR AND JUST
NORTH OF THE DEVELOPING FRONT FROM NEAR ARNETT TO CHEROKEE. WITH
RAIN POSSIBLY FORMING IN THE NEXT FEW HOURS WHICH WOULD ALLOW FOR
IMPROVING VISIBILITIES...CHOSE TO HOLD OFF ON A DENSE FOG ADVISORY
FOR THESE AREAS FOR NOW.
AFTER 9 PM TONIGHT...BELIEVE A SQUALL LINE THAT WILL LIKELY FORM
IN WEST TEXAS WILL MOVE EASTWARD THROUGH THE NIGHT. THE TIMING OF
THIS SQUALL LINE REMAINS A BIT UNCERTAIN AND LATEST HRRR RUNS HAVE
BEEN SLOWING THE LINE DOWN. THE LINE PROBABLY WOULD NOT ENTER FAR
WESTERN OKLAHOMA AND FAR WESTERN NORTH TEXAS UNTIL 9 PM...POSSIBLY
APPROACHING THE I-35 CORRIDOR AROUND 2 OR 3 AM...THEN EXITING
SOUTHEASTERN OKLAHOMA BY 9 AM.
THE GREATER POTENTIAL FOR SEVERE STORMS WITH THIS LINE SEEM TO BE
OVER WESTERN NORTH TEXAS AND WESTERN OKLAHOMA SOUTH OF THE SURFACE
FRONT MENTIONED ABOVE. SOME POCKETS OF DAMAGING WINDS UP TO 70
MPH WITH MESOVORTICES WOULD BE THE MAIN HAZARD. MARGINALLY SEVERE
HAIL WOULD BE POSSIBLE AS WELL. TORNADO POTENTIAL REMAINS VERY
LOW DUE TO LIMITED INSTABILITY NEAR THE GROUND...BUT IS NOT ZERO.
CHANCES FOR SEVERE STORMS WILL LIKELY DECREASE AS THE LINE MOVES
EASTWARD THROUGH THE NIGHT INCLUDING THE I-35 CORRIDOR AND POINTS
EAST WHERE MORE STABLE/RAIN COOLED AIR WILL EXIST.
OVERALL...DO NOT THINK THIS WILL BE A WIDESPREAD SEVERE EVENT
WITH GENERALLY A COUPLE OF WIND AND PERHAPS HAIL REPORTS.
ADDITIONAL STORMS WILL LIKELY BE OCCURRING AHEAD OF THE SQUALL
LINE...ESPECIALLY IN SOUTHEASTERN OKLAHOMA...BUT MAINLY SHOULD BE
SUBSEVERE.
SUNDAY AND SUNDAY EVENING...SHOWERS AND STORMS MAY LINGER DURING
THE MORNING HOURS NEAR AND EAST OF I-35. ADDITIONAL SHOWERS WILL
LIKELY FORM NEAR THE MID/UPPER LOW IN NORTHWESTERN OKLAHOMA. KEPT
A RAIN/SNOW MIX NORTH OF AN ARNETT TO MEDFORD LINE DURING THE DAY
WHERE WETBULB ZERO HEIGHTS FALL BELOW 1500 FT AGL. A WET DUSTING
TO AN INCH OF SNOWFALL MAINLY ON GRASSY SURFACES COULD OCCUR IN
HARPER COUNTY...BUT APPEARS THE HEAVIER SNOW ACCUMULATIONS AND
GREATER SNOW IMPACTS WILL BE NORTHWEST OF HARPER COUNTY.
THUS...DID NOT ISSUE A WINTER WEATHER ADVISORY. COOLER
TEMPERATURES WILL OCCUR. SOME SUN AND CLOUDS AS WELL AS BREEZY
CONDITIONS BY AFTERNOON WILL OCCUR IN WESTERN NORTH TEXAS AND
SOUTHERN OKLAHOMA.
LATE SUNDAY NIGHT THROUGH NEXT SATURDAY...A DRY AND QUIETER
WEATHER PATTERN IS FORECAST. TEMPERATURES WILL BE MORE SEASONABLE
DURING THIS TIME FRAME...ESPECIALLY BEYOND TUESDAY ONCE A COLD
FRONT MOVES THROUGH THE AREA.
MBS
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 50 56 34 61 / 100 60 10 0
HOBART OK 44 53 32 60 / 100 20 10 0
WICHITA FALLS TX 47 59 35 66 / 100 20 10 0
GAGE OK 37 42 27 60 / 100 70 40 0
PONCA CITY OK 52 55 35 58 / 100 90 40 0
DURANT OK 54 62 40 63 / 100 100 10 0
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...FLASH FLOOD WATCH THROUGH SUNDAY MORNING FOR OKZ048-052.
TX...NONE.
&&
$$
25/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1055 PM EST SUN DEC 13 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION ON MONDAY.
TEMPERATURES WILL BE WARM AGAIN FOR MONDAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. THIS WILL MARK THE BEGINNING OF A RETURN TO MORE
SEASONAL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
PLENTY OF HIGH CLOUDS COVERED THE STATE LATE THIS EVENING WITH
JUST A SCATTERING OF MID CLOUDS. A SHIELD OF THICKER MID LEVEL
CLOUDS OVER SWRN PENN WILL ADVANCE TO THE ENE ACROSS MUCH OF THE
FCST AREA OVER THE NEXT SEVERAL HOURS. THIS WILL KEEP TEMPS
UNSEASONABLY MILD.
LOWER STRATUS MAY ADVECT WWD/DEVELOP OVER THE WESTERN POCONOS AND
PORTIONS OF THE SUSQ VALLEY VERY LATE TONIGHT...THANKS TO A
GENERALLY WEAK LLVL EAST TO SERLY FLOW OFF THE ATLANTIC. WILL HOLD
ONTO THE MENTION OF PATCHY LIGHT DRIZZLE AND SOME AREAS OF 1SM
FOG AFTER 06Z. HOWEVER...ALTHOUGH THE LARGER GRID SPATIAL AND
TEMPORAL MODELS GENERATE SOME VERY LIGHT QPF TWD DAYBREAK...THE
LATEST 02Z HRRR IS VOID OF ANY QPF THROUGH ALL OF MONDAY MORNING.
TEMPS AND HUMIDITY OVERNIGHT WILL BE VERY HIGH FOR THIS TIME OF
YEAR /ESPECIALLY CONSIDERING THAT WE HAVE (OR RECENTLY HAD) NO
RAIN FALLING.
LOTS OF MIN TEMPS WILL COME IN ABOVE RECORDS EARLY MONDAY...
AS TEMPS STAY MAINLY IN THE 50S. SOME COOLER VALLEYS IN CENTRAL
PA COULD SEE TEMPS DIP INTO THE UPPER 40S.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
LOW CLOUDS OVER THE NE WILL PROBABLY KEEP THE TEMPS FROM CLIMBING
TOO QUICKLY THERE ON MON...BUT THE GOOD SOUTH FLOW AND TIGHTENING
PRES GRADIENT WILL LIKELY MIX THEM OUT BY AFTN. CFRONT WILL BE
ENCROACHING BY MID AFTN...AND A FEW SHRA ARE POSS OVER THE WRN
MTNS BEFORE NOON. WILL KEEP THE HIGHEST POPS BETWEEN 18Z-
00Z...STEADILY MOVING THEM W-E. TEMPS AND DEWPOINTS WILL BE CRAZY
HIGH AGAIN MON - ESP IF IT CAN CLEAR UP A LITTLE BEFORE
FROPA/PRE-FRONTAL-TROUGH SHOWERS. A STRAY RUMBLE OF THUNDER IS
POSS IN THE SE...BUT THE COOLER START TO THE DAY IN THE NE SHOULD
PRECLUDE THEM FROM HEARING THUNDER. WINDS GET GUSTY BEHIND THE
FRONT AND SOME SHOWERS ARE EXPECTED IN THE W MON NIGHT...AS TEMPS
FALL...BUT NOT NEARLY TO NORMAL MINS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
AS LOW PRESSURE AREA SLIDES EAST THROUGH NEW ENGLAND ON TUESDAY...
FLOW AROUND PERIPHERY OF LOW WILL BRING BREEZY WINDS ON TUE...WITH
COOLER YET STILL QUITE MILD TEMPS IN THE 40S AND 50S.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE ALONG THE EAST COAST SHOULD ENSURE DRY WEATHER
ACROSS CENTRAL PA OVERNIGHT. MAIN AVIATION CONCERN WILL BE THE
POTENTIAL OF LOW CIGS/FOG DEVELOPING LATE TONIGHT ACROSS THE
EASTERN HALF OF THE STATE. A SOUTHERLY BREEZE SHOULD PRECLUDE FOG
PROBLEMS AT KJST. ELSEWHERE...NEARLY CALM WINDS SHOULD PROMOTE AT
LEAST MVFR VSBYS...WITH IFR/LIFR CONDS QUITE POSSIBLE FROM KIPT
SOUTHWARD THRU KMDT/KLNS LATE TONIGHT.
MDL SOUNDINGS INDICATE LOW CIGS/FOG COULD POTENTIALLY LINGER MUCH
OF MONDAY ARND KMDT/KLNS. ELSEWHERE...AN INCREASINGLY MOIST
SOUTHERLY FLOW IN ADVANCE OF AN APPROACHING COLD FRONT WILL LIKELY
CAUSE FALLING CIGS ACROSS THE CENTRAL MTNS MON AFTN/EVENING WITH
IFR CIGS LIKELY FROM KBFD SOUTH THRU KUNV/KAOO. THE FRONT WILL
SWEEP EASTWARD ACROSS THE REGION MON EVENING...ACCOMPANIED BY A
PERIOD OF SHOWERS AND PERHAPS EVEN A TSRA IN SPOTS. A DRIER WSW
FLOW BEHIND THE FRONT SHOULD BRING IMPROVING FLYING CONDS LATE MON
NIGHT...ESP EAST /DOWNWIND/ OF THE APPALACHIAN MTNS.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
UNUSUALLY WARM DECEMBER TEMPERATURES CONTINUE FOR THE NEXT
SEVERAL DAYS...WITH THE POTENTIAL FOR SOME RECORDS TO BE BROKEN
THROUGH MONDAY. SUNDAY SHOULD BE THE WARMEST DAY OF THE BUNCH.
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 67/1979 *64/2015* 64/1927 42/27
KIPT 59/1911 *62/2015* 65/1901 39/25
KAOO *68/2015* *66/2015* 59/2006 38/24
KBFD *59/2015* *61/2015* 54/2001 33/19
*STATE COLLEGE 63/1979 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
MAX-MINIMUM TEMPERATURES OF RECORD (AKA WARMEST LOWS)...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH
---------------------------------------------------------------------
KMDT 51/1911 45/1991 53/1901
KIPT 54/1911 47/1991 48/1927
KAOO *45/2015* 45/1991 44/2001
KBFD *45/2015* 39/1964 45/1991 36/2006
*STATE COLLEGE 44/1927 47/2001 41/2006
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT/RXR
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD
CLIMATE...EVANEGO
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1149 AM CST SAT DEC 12 2015
.AVIATION...
SITES SHOULD HOLD ONTO MVFR MOST OF THE AFTERNOON WITH PASSING
AREAS OF LIGHT RAIN/SHOWERS. ANY THUNDER SHOULD BE EAST OF THE TAF
SITES THIS AFTERNOON. AS THE SUN SETS THIS EVENING LOOK FOR
CEILINGS TO COME DOWN TO IFR WHILE SOUTHERLY WINDS REMAIN GUSTY
OVER 20 KTS. THE MAIN FORECAST PROBLEM WILL BE THE TIMING OF
POSSIBLE SQUALL LINE. LATEST HRRR MODELS SHOWS THE LINE OF STORMS
TO APPROACH AND MOVE INTO DRT BY AROUND 4Z WITH THE I-35 GETTING
IMPACTED 08-10Z TIME FRAME. THIS TIMING WILL LIKELY GET ADJUSTED
AS LATER MODEL RUNS AND RADAR CAN PINPOINT THE TIMING. LOOKS TO BE
A QUICK MOVING LINE OF STORMS SO WINDS IN EXCESS OF 40KT IS
LIKELY. SEVERE STORMS ARE NOT OUT OF THE QUESTION BUT NOT
CONFIDENT ENOUGH AT THIS POINT TO INPUT ANY SEVERE PARAMETERS.
CLEARING SHOULD TAKE PLACE RAPIDLY BEHIND THE FRONT/SQUALL LINE
WITH VFR CONDITIONS AND WESTERLY GUSTY WINDS AT ALL SITES LIKELY
BY 12Z SUNDAY.
&&
.PREV DISCUSSION... /ISSUED 544 AM CST SAT DEC 12 2015/
UPDATE...12Z AVIATION UPDATE BELOW.
AVIATION...GENERALLY MVFR CEILINGS AROUND 1200-1800 FEET
PREVAIL EARLY THIS MORNING ACROSS SOUTH-CENTRAL TEXAS. COULD SEE
SOME LOCATIONS DROP INTO IFR THROUGH THE MORNING HOURS WITH
PATCHY -DZ AND ISOLATED -SHRA DEVELOPING. MVFR CEILINGS LIKELY
TO CONTINUE AT AUS AND SAT THROUGH THE AFTERNOON HOURS. S TO SE
WINDS GRADUALLY INCREASING AFTER 15Z...BECOMING GUSTY 20-25 KTS
THROUGH THE AFTERNOON. IFR CEILINGS MAY DEVELOP AFTER SUNSET AT
SAT/AUS. A SQUALL LINE IS FORECAST TO MOVE THROUGH DRT 02Z-04Z AND
SAT/AUS 07Z-09Z. STRONG TO SEVERE STRAIGHT-LINE WIND GUSTS MAY
ACCOMPANY THE LINE OF STORMS. A COLD FRONT WILL SWEEP THROUGH THE
AREA BEHIND THE SQUALL LINE...WITH NW WINDS DEVELOPING...PRECIP
ENDING AND CEILINGS BECOMING VFR.
PREV DISCUSSION... /ISSUED 419 AM CST SAT DEC 12 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
SEVERE WEATHER AND LOCALLY HEAVY RAINFALL IS EXPECTED MAINLY
TONIGHT. RADAR LOOP CONFIRMS THE APPROACH OF A LEAD SHORT-WAVE
DISTURBANCE FROM MEXICO AND AHEAD OF A DEEP UPPER TROUGH
APPROACHING TX FROM THE PACIFIC. MODEL INDICATIONS OF INCREASING
MID LEVEL MOISTURE LEADS TO PWAT VALUES JUMPING UP TO 2 INCHES
OVER THE COASTAL PRAIRIES BY MIDDAY...WITH HIGH RAIN CHANCES
COVERING MUCH OF THE EASTERN HALF OF TX. AS NOTED BY SPC THE HIGH
AMOUNT OF MOISTURE SHOULD LIMIT THE POTENTIAL FOR DAYTIME
SEVERITY...WITH NEAR CONTINUOUS CLOUDINESS LIMITING STORM
STRENGTH. SHOULD BREAKS IN THE CLOUDS OCCUR THERE IS A SMALL
POTENTIAL FOR LOW TOPPED SUPERCELLS GIVEN THE FORECAST
HELICITIES.
INCREASING LOW TO MID LEVEL WINDS IN ADVANCE OF THE APPROACHING
UPPER TROUGH WILL SET UP BEST LOW LEVEL CONVERGENCE OVER THE I-45
CORRIDOR FOR HIGHEST QPF AMOUNTS...BUT SOME OF THE HIGHER RES DATA
DEPICTS AN AREA OF POTENTIAL TRAINING EXTENDING SW INTO OUR FAR
EASTERN COUNTIES. THE FINAL FORECAST HOUR OF THE HRRR SUGGESTS
INCREASED TRAINING POTENTIAL BY 23Z WITH OTHER HIGH-RES SOLUTIONS
CONTINUING A LOCALLY HEAVY RAIN THREAT OVER EASTERN COUNTIES IN
THE EVENING. FAST STORM MOTIONS ARE EXPECTED TO OFFSET THE
TRAINING PROBLEM...BUT THE HIGH PWAT ENVIRONMENT IS STILL LIKELY
TO DUMP ISOLATED DOWNPOURS OF AROUND 2 INCHES BEFORE MIDNIGHT.
BASED ON WHAT DEVELOPS LATE THIS AFTERNOON...LATER SHIFTS MAY NEED
TO MONITOR FOR A POSSIBLE FLASH FLOOD WATCH OVER EASTERN
COUNTIES...AS A MORE WIDESPREAD ROUND OF RAIN ARRIVES LATE
TONIGHT.
MODELS AND THE WPC SHOW A PRETTY CONSISTENT QPF PATTERN WITH
GENERALLY TWO ENHANCED CLUSTERS OF CONVECTION...AND THE LATTER
ROUND OF RAIN IS LIKELY TO PRODUCE A NEAR SOLID LINE OF STRONG TO
SEVERE STORMS WITH VERY HEAVY RAINFALL RATES. AGAIN THE MOTIONS
WILL BE FAST SO WE/RE EXPECTING A QUICK 1 TO 2 INCHES OF RAIN
FALLING IN A SHORT TIME FOLLOWED BY A BRIEF PERIOD OF MODERATE
RAIN. BY THE END OF THE RAIN EVENT SUNDAY MORNING...A FEW SPOTS
WELL TO THE EAST OF AUSTIN COULD RECEIVE 4 INCHES. BOWING SEGMENTS
WITH THE OVERNIGHT ROUND OF RAIN WILL BE DRIVEN BY THE UPPER
TROUGH AND COULD LEAD TO DAMAGING WINDS AND AN ISOLATED TORNADO
THREAT. THE SPC HAS EXPANDED THE SLIGHT RISK AREA FOR ALL BUT THE
COUNTIES ALONG THE RIO GRANDE...AND OUR FORECAST MENTIONS SEVERE
STORMS AS POSSIBLE OVER ALL AREAS.
LIGHTEST RAINFALL AMOUNTS AND STORM POTENTIAL BEING NEAR THE RIO
GRANDE COULD LEAD TO OUR NEXT THREAT CONCERN FOR DAYTIME SUNDAY.
SHOULD AREAS NEAR THE RIO GRANDE FAIL TO RECEIVE SIGNIFICANT
RAINFALL...WINDY AND DRY CONDITIONS BEHIND THE FRONT WOULD PRODUCE
FAVORABLE CONDITIONS FOR THE SPREAD OF FIRES. MODEL RUNS ARE
TRENDING WETTER AND FARTHER WEST WITH HIGHER RAIN CHANCES...SO
THIS CONCERN COULD POSSIBLY DECREASE GOING FORWARD. THE
DOWNSLOPING WESTERLY WINDS WILL LIKELY KEEP HIGH TEMPERATURES
ABOVE SEASONAL NORMS SUNDAY.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
DECREASING WESTERLY WINDS AND THE ADVANCE OF MUCH DRIER AIR INTO
THE AREA WILL TAKE OVERNIGHT TEMPERATURES BACK TO NEAR NORMALS FOR
MONDAY MORNING. WARMING SW WINDS RETURN FOR MONDAY INTO
TUESDAY...AND SOME MOISTURE POOLING OVER THE COASTAL PRAIRIES
COULD LEAD TO A FEW SHOWERS FORMING TUESDAY INTO EARLY WEDNESDAY.
BROAD TROUGHING DEVELOPING OVER THE U.S. BY THIS TIME WILL BRING A
COLD FRONT THROUGH TX AND TAKE TEMPERATURES BELOW SEASONAL NORMALS
FOR THE REST OF THE WORK WEEK. CURRENT MIN FORECAST TEMPERATURES
SHOW FREEZES POSSIBLE MAINLY OVER AREAS THAT ALREADY HAD THEM IN
NOVEMBER.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 54 68 47 71 / 70 90 40 - 0
AUSTIN BERGSTROM INTL AIRPORT 77 54 68 41 71 / 70 90 40 - 0
NEW BRAUNFELS MUNI AIRPORT 78 53 70 41 72 / 60 90 30 0 0
BURNET MUNI AIRPORT 74 50 66 42 70 / 50 80 20 0 0
DEL RIO INTL AIRPORT 76 51 70 39 72 / 10 60 0 0 0
GEORGETOWN MUNI AIRPORT 75 52 65 41 70 / 60 90 40 - 0
HONDO MUNI AIRPORT 77 54 72 37 72 / 40 80 20 0 0
SAN MARCOS MUNI AIRPORT 77 53 69 42 71 / 70 90 40 - 0
LA GRANGE - FAYETTE REGIONAL 78 58 66 45 72 / 80 90 60 - 0
SAN ANTONIO INTL AIRPORT 78 55 71 43 73 / 60 80 20 0 0
STINSON MUNI AIRPORT 78 56 72 41 72 / 60 80 20 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...05
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1141 AM CST SAT DEC 12 2015
.AVIATION...
LOW CIGS AND VISBYS WILL CONTINUE TO STICK AROUND THE KCDS
TERMINAL THROUGH EARLY AFTERNOON UNDER CONTINUED SOUTHEASTERLY
WINDS. STRONG WINDS WILL DEVELOP AT KPVW/KLBB THIS AFTERNOON WITH
THE APPROACH OF A STRONG UPPER LEVEL STORM SYSTEM. WINDS WILL TURN
TO THE WEST THIS EVENING FOLLOWING THE PASSAGE OF A COLD FRONT AND
WILL BE CAPABLE OF GENERATING WIDESPREAD THUNDERSTORMS. BEST
CHANCES FOR STORMS WILL BE EAST OF KLBB/KPVW AND MAY AFFECT KCDS
THIS EVENING. STORMS WILL RAPIDLY MOVE OUT OF THE KCDS TERMINAL
AFTER MIDNIGHT OR SO. STRONGER WINDS FROM THE NORTHWEST WILL
SPREAD OVER THE REGION BEGINNING LATE SUNDAY MORNING.
&&
PREV DISCUSSION... /ISSUED 232 AM CST SAT DEC 12 2015/
SHORT TERM...
MAIN CONCERN FOR THE SHORT TERM PERIOD WILL BE INCREASING CHANCES
FOR RAIN SHOWERS AND THUNDERSTORMS...WITH A BRIEF WINDOW FOR A FEW
STORMS TO POSSIBLY NEAR STRONG LEVELS.
SFC TEMPS PER 08Z METARS WERE MILD FOR THIS TIME OF YEAR /40S AND
50S/ COURTESY OF S-SW SFC WINDS...WHICH IS A WIND COMPONENT
CONDUCIVE FOR DRY AND WARM CONDITIONS. HOWEVER...DEWPOINTS IN THE
40S EXISTED ACROSS THE LOW ROLLING PLAINS AS THE WIND WAS MORE FROM
THE S-SE THUS AIDING TO FILTER IN GULF MOISTURE. IN FACT...LOW
CLOUDS AND/OR FOG WERE NOTED ACROSS THE BIG COUNTRY REGION...WHICH
MAY HAVE A CHANCE AT SPREADING TOWARDS THE ROLLING PLAINS AOA
SUNRISE. THE HRRR IS MOST AGGRESSIVE IN THE STRATUS DECK/FOG MAKING
IT AS FAR NW TO KLBB...WITH OTHER SOLUTIONS MAINTAINING THE IT TO
THE LOW ROLLING PLAINS AND PERHAPS THE SRN SOUTH PLAINS. HENCE WILL
BE KEEPING AN EYE ON TRENDS FOR THE NEXT SEVERAL HOURS.
THE STORM SYSTEM OF INTEREST IS AN UA TROUGH DRAPED FROM THE GREAT
BASIN TO ACROSS WRN AZ EARLY THIS MORNING. MOST MODEL SOLUTIONS
AGREE THAT THIS SYSTEM WILL BE RATHER PROGRESSIVE...AS IT IS PROGGED
TO BE ACROSS ERN AZ/WRN NM THIS AFTN TO ACROSS CNTRL NM THIS
EVENING...AND FINALLY ACROSS THE PANHANDLE REGION LATE TONIGHT/EARLY
SUN MORNING...ALL THE WHILE EVOLVING TO MORE OF A CLOSED OFF STATE.
THE ECMWF STILL REMAINS THE OUTLIER WITH IT BEING SLIGHTLY SLOWER
AND FARTHER SOUTH VERSUS THE NAM AND GFS SOLUTIONS. THIS AFTN-
EVENING AS THE SYSTEM DRAWS NEAR...ITS SFC COUNTERPART WILL RESPOND
BY DEEPENING AND THEREFORE PROMOTE A TIGHTENED PRESSURE GRADIENT
WHILST TRANSLATING EAST ACROSS THE CWA. MOS GUIDANCE HINTS AT SFC
WIND SPEEDS OF 15-25 MPH OUT OF THE W-SW...WITH THE BREEZIEST
CONDITIONS NOTED ON THE CAPROCK. OFF THE CAPROCK...SFC WINDS WILL BE
OUT OF THE S-SE. PERSISTENT SWRLY FLOW ALOFT AIDING IN TRANSPORTING
HIGH LEVEL CIRRUS CLOUD COVER WILL BE SLOW TO CLEAR OUT FROM WEST TO
EAST...WHERE IF THERE WERE CLEAR SKIES...WIND CONDITIONS COULD BE A
LOT WORSE. CLOUD COVER WILL BE LAST TO CLEAR OUT ACROSS THE ERN
ZONES GIVEN THE FAVORABLE UPSLOPE WIND COMPONENT.
CONCURRENTLY...A 160 KT 250 MB JET MAX WILL MOVE ACROSS THE
CWA...PROVIDING UL SUPPORT AND ENCOURAGE THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS MOVING IN FROM WEST TO EAST. MID-LEVEL INSTABILITY
IS NOT VERY IMPRESSIVE /400-600 J/KG/ BUT THE 0-6 KM BULK SHEAR OF
40-70 KTS AND A SLIGHT COOLING IN THE MID-LEVELS /STEEPENING LAPSE
RATES/ DO SUGGEST SOME THUNDERSTORMS APPROACHING STRONG LEVELS
/HAIL AND WIND THE PRIMARY THREATS/ PARTICULARLY ACROSS THE ROLLING
PLAINS...COINCIDING WITH THE BEST MOISTURE AND MID-LEVEL INSTABILITY.
KEEP IN MIND...IF THE CLOUD COVER HANGS AROUND A LITTLE LONGER THAN
ANTICIPATED ACROSS THE ROLLING PLAINS...THE LITTLE BIT OF MID-LEVEL
INSTABILITY MAY NOT BE ENOUGH TO OVERCOME THE CAPPED ATMOSPHERE AND
THUS STRONG THUNDERSTORMS MAY NOT BECOME REALIZED. THE LLJ KICKING
UP INTO THE 40-50 KT RANGE WILL MAINTAIN STORMS ACROSS THE ROLLING
PLAINS THIS EVENING-TONIGHT WHILST THE REMAINDER OF THE CWA BECOMES
ENVELOPED BY DRY-SLOTTING /W-SW WINDS/. SOUNDING PROFILES INDICATE
THIS SCENARIO RATHER WELL WITH TOP-DOWN MOISTENING OCCURRING THIS
AFTN-EVENING...AND DRYING ENSUING IN THE MID AND UPPER LEVELS BY
TONIGHT. LCL/S ARE A BIT LOW ACROSS THE FAR ROLLING PLAINS WHICH
RAISES CONCERNS FOR A TORNADO RISK. HOWEVER...THE AMOUNT OF 0-6 KM
BULK SHEAR MIGHT BE TOO MUCH OF A GOOD THING...AS IT COULD PREVENT
STORMS FROM MAINTAINING GOOD STRUCTURE.
500 MB HEIGHT FALLS WILL LEAD TO A COOLER ALBEIT STILL UNSEASONABLY
WARM SATURDAY...WITH HIGHS IN THE 60S AND 70S...FOLLOWED BY LOWS IN
THE 30S AND 40S.
LONG TERM...
COULD SEE A FEW LIGHT RAIN OR SNOW SHOWERS SUNDAY MORNING ACROSS THE
FAR SRN PANHANDLE AS THE CLOSED LOW SLOWLY EJECTS TO THE ENE ACROSS
THE PANHANDLE TO NWRN OKLAHOMA. HOWEVER...MAIN STORY TURNING OUT TO
BE WIND AS TIGHT LOW TO MID LEVEL HEIGHT GRADIENT ON THE S/SW FLANKS
OF THE UPPER LOW WILL LIKELY TRANSLATE INTO AT LEAST 20-30 MPH RANGE
ACROSS MUCH OF THE FCST AREA IN LINE WITH MOS VALUES AS COLD
ADVECTION WILL LIMIT THE POTENTIAL FOR 50 KT MID LEVEL WINDS TO MIX
TO THE SFC.
AFTER SHORT WAVE RIDGING BRINGS A WARMER AND LESS WINDY DAY
MONDAY...ANOTHER UPPER LOW PROGGED TO MOVE ACROSS THE COLORADO
ROCKIES MONDAY NIGHT AND ONTO THE CNTL HIGH PLAINS DURING THE DAY
TUESDAY. MODELS CURRENTLY PROGGING RAPID CYCLOGENESIS SERN COLO/SWRN
KANSAS EARLY TUESDAY WITH A MID LEVEL JET STREAK ON THE ORDER OF 50
TO 70 KTS ROTATING OVER THE SRN HIGH PLAINS DURING THE DAY TUESDAY.
DEEP COLD ADVECTION WILL AGAIN LIMIT POTENTIAL FOR MIXING TO THE
SFC...BUT AGAIN POTENTIAL EXISTS FOR AT LEAST 20-30 MPH TO BE
REALIZED.
BEYOND TUESDAY...A BROAD LONG WAVE UPPER TROUGH OVER THE WRN CONUS
WILL SHIFT EWD TO THE PLAINS WEDNESDAY LEAVING DRY AND UNEVENTFUL
NWLY FLOW OVER THE FCST AREA THROUGH THE END OF THE WEEK. COLD FRONT
OF CANADIAN ORIGIN BEHIND TUESDAYS UPPER LOW WILL BRING COLDER AIR
INTO THE REGION WITH TEMPS FINALLY REVERTING TO BELOW NORMAL
WEDNESDAY AND THURSDAY BEFORE MODERATING TO END THE WEEK.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
01
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
544 AM CST SAT DEC 12 2015
.UPDATE...12Z AVIATION UPDATE BELOW.
&&
.AVIATION...GENERALLY MVFR CEILINGS AROUND 1200-1800 FEET
PREVAIL EARLY THIS MORNING ACROSS SOUTH-CENTRAL TEXAS. COULD SEE
SOME LOCATIONS DROP INTO IFR THROUGH THE MORNING HOURS WITH
PATCHY -DZ AND ISOLATED -SHRA DEVELOPING. MVFR CEILINGS LIKELY
TO CONTINUE AT AUS AND SAT THROUGH THE AFTERNOON HOURS. S TO SE
WINDS GRADUALLY INCREASING AFTER 15Z...BECOMING GUSTY 20-25 KTS
THROUGH THE AFTERNOON. IFR CEILINGS MAY DEVELOP AFTER SUNSET AT
SAT/AUS. A SQUALL LINE IS FORECAST TO MOVE THROUGH DRT 02Z-04Z AND
SAT/AUS 07Z-09Z. STRONG TO SEVERE STRAIGHT-LINE WIND GUSTS MAY
ACCOMPANY THE LINE OF STORMS. A COLD FRONT WILL SWEEP THROUGH THE
AREA BEHIND THE SQUALL LINE...WITH NW WINDS DEVELOPING...PRECIP
ENDING AND CEILINGS BECOMING VFR.
&&
.PREV DISCUSSION... /ISSUED 419 AM CST SAT DEC 12 2015/
SHORT TERM (TODAY THROUGH SUNDAY)...
SEVERE WEATHER AND LOCALLY HEAVY RAINFALL IS EXPECTED MAINLY
TONIGHT. RADAR LOOP CONFIRMS THE APPROACH OF A LEAD SHORT-WAVE
DISTURBANCE FROM MEXICO AND AHEAD OF A DEEP UPPER TROUGH
APPROACHING TX FROM THE PACIFIC. MODEL INDICATIONS OF INCREASING
MID LEVEL MOISTURE LEADS TO PWAT VALUES JUMPING UP TO 2 INCHES
OVER THE COASTAL PRAIRIES BY MIDDAY...WITH HIGH RAIN CHANCES
COVERING MUCH OF THE EASTERN HALF OF TX. AS NOTED BY SPC THE HIGH
AMOUNT OF MOISTURE SHOULD LIMIT THE POTENTIAL FOR DAYTIME
SEVERITY...WITH NEAR CONTINUOUS CLOUDINESS LIMITING STORM
STRENGTH. SHOULD BREAKS IN THE CLOUDS OCCUR THERE IS A SMALL
POTENTIAL FOR LOW TOPPED SUPERCELLS GIVEN THE FORECAST
HELICITIES.
INCREASING LOW TO MID LEVEL WINDS IN ADVANCE OF THE APPROACHING
UPPER TROUGH WILL SET UP BEST LOW LEVEL CONVERGENCE OVER THE I-45
CORRIDOR FOR HIGHEST QPF AMOUNTS...BUT SOME OF THE HIGHER RES DATA
DEPICTS AN AREA OF POTENTIAL TRAINING EXTENDING SW INTO OUR FAR
EASTERN COUNTIES. THE FINAL FORECAST HOUR OF THE HRRR SUGGESTS
INCREASED TRAINING POTENTIAL BY 23Z WITH OTHER HIGH-RES SOLUTIONS
CONTINUING A LOCALLY HEAVY RAIN THREAT OVER EASTERN COUNTIES IN
THE EVENING. FAST STORM MOTIONS ARE EXPECTED TO OFFSET THE
TRAINING PROBLEM...BUT THE HIGH PWAT ENVIRONMENT IS STILL LIKELY
TO DUMP ISOLATED DOWNPOURS OF AROUND 2 INCHES BEFORE MIDNIGHT.
BASED ON WHAT DEVELOPS LATE THIS AFTERNOON...LATER SHIFTS MAY NEED
TO MONITOR FOR A POSSIBLE FLASH FLOOD WATCH OVER EASTERN
COUNTIES...AS A MORE WIDESPREAD ROUND OF RAIN ARRIVES LATE
TONIGHT.
MODELS AND THE WPC SHOW A PRETTY CONSISTENT QPF PATTERN WITH
GENERALLY TWO ENHANCED CLUSTERS OF CONVECTION...AND THE LATTER
ROUND OF RAIN IS LIKELY TO PRODUCE A NEAR SOLID LINE OF STRONG TO
SEVERE STORMS WITH VERY HEAVY RAINFALL RATES. AGAIN THE MOTIONS
WILL BE FAST SO WE/RE EXPECTING A QUICK 1 TO 2 INCHES OF RAIN
FALLING IN A SHORT TIME FOLLOWED BY A BRIEF PERIOD OF MODERATE
RAIN. BY THE END OF THE RAIN EVENT SUNDAY MORNING...A FEW SPOTS
WELL TO THE EAST OF AUSTIN COULD RECEIVE 4 INCHES. BOWING SEGMENTS
WITH THE OVERNIGHT ROUND OF RAIN WILL BE DRIVEN BY THE UPPER
TROUGH AND COULD LEAD TO DAMAGING WINDS AND AN ISOLATED TORNADO
THREAT. THE SPC HAS EXPANDED THE SLIGHT RISK AREA FOR ALL BUT THE
COUNTIES ALONG THE RIO GRANDE...AND OUR FORECAST MENTIONS SEVERE
STORMS AS POSSIBLE OVER ALL AREAS.
LIGHTEST RAINFALL AMOUNTS AND STORM POTENTIAL BEING NEAR THE RIO
GRANDE COULD LEAD TO OUR NEXT THREAT CONCERN FOR DAYTIME SUNDAY.
SHOULD AREAS NEAR THE RIO GRANDE FAIL TO RECEIVE SIGNIFICANT
RAINFALL...WINDY AND DRY CONDITIONS BEHIND THE FRONT WOULD PRODUCE
FAVORABLE CONDITIONS FOR THE SPREAD OF FIRES. MODEL RUNS ARE
TRENDING WETTER AND FARTHER WEST WITH HIGHER RAIN CHANCES...SO
THIS CONCERN COULD POSSIBLY DECREASE GOING FORWARD. THE
DOWNSLOPING WESTERLY WINDS WILL LIKELY KEEP HIGH TEMPERATURES
ABOVE SEASONAL NORMS SUNDAY.
LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
DECREASING WESTERLY WINDS AND THE ADVANCE OF MUCH DRIER AIR INTO
THE AREA WILL TAKE OVERNIGHT TEMPERATURES BACK TO NEAR NORMALS FOR
MONDAY MORNING. WARMING SW WINDS RETURN FOR MONDAY INTO
TUESDAY...AND SOME MOISTURE POOLING OVER THE COASTAL PRAIRIES
COULD LEAD TO A FEW SHOWERS FORMING TUESDAY INTO EARLY WEDNESDAY.
BROAD TROUGHING DEVELOPING OVER THE U.S. BY THIS TIME WILL BRING A
COLD FRONT THROUGH TX AND TAKE TEMPERATURES BELOW SEASONAL NORMALS
FOR THE REST OF THE WORK WEEK. CURRENT MIN FORECAST TEMPERATURES
SHOW FREEZES POSSIBLE MAINLY OVER AREAS THAT ALREADY HAD THEM IN
NOVEMBER.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 54 68 47 71 / 70 90 40 - 0
AUSTIN BERGSTROM INTL AIRPORT 77 54 68 41 71 / 70 90 40 - 0
NEW BRAUNFELS MUNI AIRPORT 78 53 70 41 72 / 60 90 30 0 0
BURNET MUNI AIRPORT 74 50 66 42 70 / 50 80 20 0 0
DEL RIO INTL AIRPORT 76 51 70 39 72 / 10 60 0 0 0
GEORGETOWN MUNI AIRPORT 75 52 65 41 70 / 60 90 40 - 0
HONDO MUNI AIRPORT 77 54 72 37 72 / 40 80 20 0 0
SAN MARCOS MUNI AIRPORT 77 53 69 42 71 / 70 90 40 - 0
LA GRANGE - FAYETTE REGIONAL 78 58 66 45 72 / 80 90 60 - 0
SAN ANTONIO INTL AIRPORT 78 55 71 43 73 / 60 80 20 0 0
STINSON MUNI AIRPORT 78 56 72 41 72 / 60 80 20 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...RUNYEN
SYNOPTIC/GRIDS...OAKS
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
522 AM CST SAT DEC 12 2015
.AVIATION...
SCT-BKN MVFR DECKS WELL SOUTH OF ALL TERMINALS COULD SPREAD AND
IMPACT KCDS LATER THIS MORNING THROUGH MID-AFTERNOON. WILL
MAINTAIN A MVFR CIG MENTION AT KCDS AT THIS TIME. OTHERWISE...VFR
CONDITIONS ARE EXPECTED WITH WEST TO SOUTHWEST WIND SPEEDS
INCREASING TO BETWEEN 15-20 KTS SUSTAINED DURING THE AFTERNOON.
WIND SPEEDS WILL DECLINE SHORTLY AFTER SUNSET THOUGH WILL STAY UP
A BIT IN THE 10-15 KT RANGE. STORM SYSTEM APPROACHING THE AREA
FROM THE WEST WILL PROMOTE INCREASING CHANCES FOR -SHRA/-TSRA.
CONFIDENCE IS HIGH ENOUGH TO INSERT A PROB30 AT KCDS WITH THIS TAF
CYCLE. WILL OF COURSE AMEND AS NECESSARY.
&&
.PREV DISCUSSION... /ISSUED 232 AM CST SAT DEC 12 2015/
SHORT TERM...
MAIN CONCERN FOR THE SHORT TERM PERIOD WILL BE INCREASING CHANCES
FOR RAIN SHOWERS AND THUNDERSTORMS...WITH A BRIEF WINDOW FOR A FEW
STORMS TO POSSIBLY NEAR STRONG LEVELS.
SFC TEMPS PER 08Z METARS WERE MILD FOR THIS TIME OF YEAR /40S AND
50S/ COURTESY OF S-SW SFC WINDS...WHICH IS A WIND COMPONENT
CONDUCIVE FOR DRY AND WARM CONDITIONS. HOWEVER...DEWPOINTS IN THE
40S EXISTED ACROSS THE LOW ROLLING PLAINS AS THE WIND WAS MORE FROM
THE S-SE THUS AIDING TO FILTER IN GULF MOISTURE. IN FACT...LOW
CLOUDS AND/OR FOG WERE NOTED ACROSS THE BIG COUNTRY REGION...WHICH
MAY HAVE A CHANCE AT SPREADING TOWARDS THE ROLLING PLAINS AOA
SUNRISE. THE HRRR IS MOST AGGRESSIVE IN THE STRATUS DECK/FOG MAKING
IT AS FAR NW TO KLBB...WITH OTHER SOLUTIONS MAINTAINING THE IT TO
THE LOW ROLLING PLAINS AND PERHAPS THE SRN SOUTH PLAINS. HENCE WILL
BE KEEPING AN EYE ON TRENDS FOR THE NEXT SEVERAL HOURS.
THE STORM SYSTEM OF INTEREST IS AN UA TROUGH DRAPED FROM THE GREAT
BASIN TO ACROSS WRN AZ EARLY THIS MORNING. MOST MODEL SOLUTIONS
AGREE THAT THIS SYSTEM WILL BE RATHER PROGRESSIVE...AS IT IS PROGGED
TO BE ACROSS ERN AZ/WRN NM THIS AFTN TO ACROSS CNTRL NM THIS
EVENING...AND FINALLY ACROSS THE PANHANDLE REGION LATE TONIGHT/EARLY
SUN MORNING...ALL THE WHILE EVOLVING TO MORE OF A CLOSED OFF STATE.
THE ECMWF STILL REMAINS THE OUTLIER WITH IT BEING SLIGHTLY SLOWER
AND FARTHER SOUTH VERSUS THE NAM AND GFS SOLUTIONS. THIS AFTN-
EVENING AS THE SYSTEM DRAWS NEAR...ITS SFC COUNTERPART WILL RESPOND
BY DEEPENING AND THEREFORE PROMOTE A TIGHTENED PRESSURE GRADIENT
WHILST TRANSLATING EAST ACROSS THE CWA. MOS GUIDANCE HINTS AT SFC
WIND SPEEDS OF 15-25 MPH OUT OF THE W-SW...WITH THE BREEZIEST
CONDITIONS NOTED ON THE CAPROCK. OFF THE CAPROCK...SFC WINDS WILL BE
OUT OF THE S-SE. PERSISTENT SWRLY FLOW ALOFT AIDING IN TRANSPORTING
HIGH LEVEL CIRRUS CLOUD COVER WILL BE SLOW TO CLEAR OUT FROM WEST TO
EAST...WHERE IF THERE WERE CLEAR SKIES...WIND CONDITIONS COULD BE A
LOT WORSE. CLOUD COVER WILL BE LAST TO CLEAR OUT ACROSS THE ERN
ZONES GIVEN THE FAVORABLE UPSLOPE WIND COMPONENT.
CONCURRENTLY...A 160 KT 250 MB JET MAX WILL MOVE ACROSS THE
CWA...PROVIDING UL SUPPORT AND ENCOURAGE THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS MOVING IN FROM WEST TO EAST. MID-LEVEL INSTABILITY
IS NOT VERY IMPRESSIVE /400-600 J/KG/ BUT THE 0-6 KM BULK SHEAR OF
40-70 KTS AND A SLIGHT COOLING IN THE MID-LEVELS /STEEPENING LAPSE
RATES/ DO SUGGEST SOME THUNDERSTORMS APPROACHING STRONG LEVELS
/HAIL AND WIND THE PRIMARY THREATS/ PARTICULARLY ACROSS THE ROLLING
PLAINS...COINCIDING WITH THE BEST MOISTURE AND MID-LEVEL INSTABILITY.
KEEP IN MIND...IF THE CLOUD COVER HANGS AROUND A LITTLE LONGER THAN
ANTICIPATED ACROSS THE ROLLING PLAINS...THE LITTLE BIT OF MID-LEVEL
INSTABILITY MAY NOT BE ENOUGH TO OVERCOME THE CAPPED ATMOSPHERE AND
THUS STRONG THUNDERSTORMS MAY NOT BECOME REALIZED. THE LLJ KICKING
UP INTO THE 40-50 KT RANGE WILL MAINTAIN STORMS ACROSS THE ROLLING
PLAINS THIS EVENING-TONIGHT WHILST THE REMAINDER OF THE CWA BECOMES
ENVELOPED BY DRY-SLOTTING /W-SW WINDS/. SOUNDING PROFILES INDICATE
THIS SCENARIO RATHER WELL WITH TOP-DOWN MOISTENING OCCURRING THIS
AFTN-EVENING...AND DRYING ENSUING IN THE MID AND UPPER LEVELS BY
TONIGHT. LCL/S ARE A BIT LOW ACROSS THE FAR ROLLING PLAINS WHICH
RAISES CONCERNS FOR A TORNADO RISK. HOWEVER...THE AMOUNT OF 0-6 KM
BULK SHEAR MIGHT BE TOO MUCH OF A GOOD THING...AS IT COULD PREVENT
STORMS FROM MAINTAINING GOOD STRUCTURE.
500 MB HEIGHT FALLS WILL LEAD TO A COOLER ALBEIT STILL UNSEASONABLY
WARM SATURDAY...WITH HIGHS IN THE 60S AND 70S...FOLLOWED BY LOWS IN
THE 30S AND 40S.
LONG TERM...
COULD SEE A FEW LIGHT RAIN OR SNOW SHOWERS SUNDAY MORNING ACROSS THE
FAR SRN PANHANDLE AS THE CLOSED LOW SLOWLY EJECTS TO THE ENE ACROSS
THE PANHANDLE TO NWRN OKLAHOMA. HOWEVER...MAIN STORY TURNING OUT TO
BE WIND AS TIGHT LOW TO MID LEVEL HEIGHT GRADIENT ON THE S/SW FLANKS
OF THE UPPER LOW WILL LIKELY TRANSLATE INTO AT LEAST 20-30 MPH RANGE
ACROSS MUCH OF THE FCST AREA IN LINE WITH MOS VALUES AS COLD
ADVECTION WILL LIMIT THE POTENTIAL FOR 50 KT MID LEVEL WINDS TO MIX
TO THE SFC.
AFTER SHORT WAVE RIDGING BRINGS A WARMER AND LESS WINDY DAY
MONDAY...ANOTHER UPPER LOW PROGGED TO MOVE ACROSS THE COLORADO
ROCKIES MONDAY NIGHT AND ONTO THE CNTL HIGH PLAINS DURING THE DAY
TUESDAY. MODELS CURRENTLY PROGGING RAPID CYCLOGENESIS SERN COLO/SWRN
KANSAS EARLY TUESDAY WITH A MID LEVEL JET STREAK ON THE ORDER OF 50
TO 70 KTS ROTATING OVER THE SRN HIGH PLAINS DURING THE DAY TUESDAY.
DEEP COLD ADVECTION WILL AGAIN LIMIT POTENTIAL FOR MIXING TO THE
SFC...BUT AGAIN POTENTIAL EXISTS FOR AT LEAST 20-30 MPH TO BE
REALIZED.
BEYOND TUESDAY...A BROAD LONG WAVE UPPER TROUGH OVER THE WRN CONUS
WILL SHIFT EWD TO THE PLAINS WEDNESDAY LEAVING DRY AND UNEVENTFUL
NWLY FLOW OVER THE FCST AREA THROUGH THE END OF THE WEEK. COLD FRONT
OF CANADIAN ORIGIN BEHIND TUESDAYS UPPER LOW WILL BRING COLDER AIR
INTO THE REGION WITH TEMPS FINALLY REVERTING TO BELOW NORMAL
WEDNESDAY AND THURSDAY BEFORE MODERATING TO END THE WEEK.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
419 AM CST SAT DEC 12 2015
.SHORT TERM (TODAY THROUGH SUNDAY)...
SEVERE WEATHER AND LOCALLY HEAVY RAINFALL IS EXPECTED MAINLY
TONIGHT. RADAR LOOP CONFIRMS THE APPROACH OF A LEAD SHORT-WAVE
DISTURBANCE FROM MEXICO AND AHEAD OF A DEEP UPPER TROUGH
APPROACHING TX FROM THE PACIFIC. MODEL INDICATIONS OF INCREASING
MID LEVEL MOISTURE LEADS TO PWAT VALUES JUMPING UP TO 2 INCHES
OVER THE COASTAL PRAIRIES BY MIDDAY...WITH HIGH RAIN CHANCES
COVERING MUCH OF THE EASTERN HALF OF TX. AS NOTED BY SPC THE HIGH
AMOUNT OF MOISTURE SHOULD LIMIT THE POTENTIAL FOR DAYTIME
SEVERITY...WITH NEAR CONTINUOUS CLOUDINESS LIMITING STORM
STRENGTH. SHOULD BREAKS IN THE CLOUDS OCCUR THERE IS A SMALL
POTENTIAL FOR LOW TOPPED SUPERCELLS GIVEN THE FORECAST
HELICITIES.
INCREASING LOW TO MID LEVEL WINDS IN ADVANCE OF THE APPROACHING
UPPER TROUGH WILL SET UP BEST LOW LEVEL CONVERGENCE OVER THE I-45
CORRIDOR FOR HIGHEST QPF AMOUNTS...BUT SOME OF THE HIGHER RES DATA
DEPICTS AN AREA OF POTENTIAL TRAINING EXTENDING SW INTO OUR FAR
EASTERN COUNTIES. THE FINAL FORECAST HOUR OF THE HRRR SUGGESTS
INCREASED TRAINING POTENTIAL BY 23Z WITH OTHER HIGH-RES SOLUTIONS
CONTINUING A LOCALLY HEAVY RAIN THREAT OVER EASTERN COUNTIES IN
THE EVENING. FAST STORM MOTIONS ARE EXPECTED TO OFFSET THE
TRAINING PROBLEM...BUT THE HIGH PWAT ENVIRONMENT IS STILL LIKELY
TO DUMP ISOLATED DOWNPOURS OF AROUND 2 INCHES BEFORE MIDNIGHT.
BASED ON WHAT DEVELOPS LATE THIS AFTERNOON...LATER SHIFTS MAY NEED
TO MONITOR FOR A POSSIBLE FLASH FLOOD WATCH OVER EASTERN
COUNTIES...AS A MORE WIDESPREAD ROUND OF RAIN ARRIVES LATE
TONIGHT.
MODELS AND THE WPC SHOW A PRETTY CONSISTENT QPF PATTERN WITH
GENERALLY TWO ENHANCED CLUSTERS OF CONVECTION...AND THE LATTER
ROUND OF RAIN IS LIKELY TO PRODUCE A NEAR SOLID LINE OF STRONG TO
SEVERE STORMS WITH VERY HEAVY RAINFALL RATES. AGAIN THE MOTIONS
WILL BE FAST SO WE/RE EXPECTING A QUICK 1 TO 2 INCHES OF RAIN
FALLING IN A SHORT TIME FOLLOWED BY A BRIEF PERIOD OF MODERATE
RAIN. BY THE END OF THE RAIN EVENT SUNDAY MORNING...A FEW SPOTS
WELL TO THE EAST OF AUSTIN COULD RECEIVE 4 INCHES. BOWING SEGMENTS
WITH THE OVERNIGHT ROUND OF RAIN WILL BE DRIVEN BY THE UPPER
TROUGH AND COULD LEAD TO DAMAGING WINDS AND AN ISOLATED TORNADO
THREAT. THE SPC HAS EXPANDED THE SLIGHT RISK AREA FOR ALL BUT THE
COUNTIES ALONG THE RIO GRANDE...AND OUR FORECAST MENTIONS SEVERE
STORMS AS POSSIBLE OVER ALL AREAS.
LIGHTEST RAINFALL AMOUNTS AND STORM POTENTIAL BEING NEAR THE RIO
GRANDE COULD LEAD TO OUR NEXT THREAT CONCERN FOR DAYTIME SUNDAY.
SHOULD AREAS NEAR THE RIO GRANDE FAIL TO RECEIVE SIGNIFICANT
RAINFALL...WINDY AND DRY CONDITIONS BEHIND THE FRONT WOULD PRODUCE
FAVORABLE CONDITIONS FOR THE SPREAD OF FIRES. MODEL RUNS ARE
TRENDING WETTER AND FARTHER WEST WITH HIGHER RAIN CHANCES...SO
THIS CONCERN COULD POSSIBLY DECREASE GOING FORWARD. THE
DOWNSLOPING WESTERLY WINDS WILL LIKELY KEEP HIGH TEMPERATURES
ABOVE SEASONAL NORMS SUNDAY.
&&
.LONG TERM (SUNDAY NIGHT THROUGH FRIDAY)...
DECREASING WESTERLY WINDS AND THE ADVANCE OF MUCH DRIER AIR INTO
THE AREA WILL TAKE OVERNIGHT TEMPERATURES BACK TO NEAR NORMALS FOR
MONDAY MORNING. WARMING SW WINDS RETURN FOR MONDAY INTO
TUESDAY...AND SOME MOISTURE POOLING OVER THE COASTAL PRAIRIES
COULD LEAD TO A FEW SHOWERS FORMING TUESDAY INTO EARLY WEDNESDAY.
BROAD TROUGHING DEVELOPING OVER THE U.S. BY THIS TIME WILL BRING A
COLD FRONT THROUGH TX AND TAKE TEMPERATURES BELOW SEASONAL NORMALS
FOR THE REST OF THE WORK WEEK. CURRENT MIN FORECAST TEMPERATURES
SHOW FREEZES POSSIBLE MAINLY OVER AREAS THAT ALREADY HAD THEM IN
NOVEMBER.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 54 68 47 71 / 70 90 40 - 0
AUSTIN BERGSTROM INTL AIRPORT 77 54 68 41 71 / 70 90 40 - 0
NEW BRAUNFELS MUNI AIRPORT 78 53 70 41 72 / 60 90 30 0 0
BURNET MUNI AIRPORT 74 50 66 42 70 / 50 80 20 0 0
DEL RIO INTL AIRPORT 76 51 70 39 72 / 10 60 0 0 0
GEORGETOWN MUNI AIRPORT 75 52 65 41 70 / 60 90 40 - 0
HONDO MUNI AIRPORT 77 54 72 37 72 / 40 80 20 0 0
SAN MARCOS MUNI AIRPORT 77 53 69 42 71 / 70 90 40 - 0
LA GRANGE - FAYETTE REGIONAL 78 58 66 45 72 / 80 90 60 - 0
SAN ANTONIO INTL AIRPORT 78 55 71 43 73 / 60 80 20 0 0
STINSON MUNI AIRPORT 78 56 72 41 72 / 60 80 20 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...RUNYEN
SYNOPTIC/GRIDS...OAKS
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
232 AM CST SAT DEC 12 2015
.SHORT TERM...
MAIN CONCERN FOR THE SHORT TERM PERIOD WILL BE INCREASING CHANCES
FOR RAIN SHOWERS AND THUNDERSTORMS...WITH A BRIEF WINDOW FOR A FEW
STORMS TO POSSIBLY NEAR STRONG LEVELS.
SFC TEMPS PER 08Z METARS WERE MILD FOR THIS TIME OF YEAR /40S AND
50S/ COURTESY OF S-SW SFC WINDS...WHICH IS A WIND COMPONENT
CONDUCIVE FOR DRY AND WARM CONDITIONS. HOWEVER...DEWPOINTS IN THE
40S EXISTED ACROSS THE LOW ROLLING PLAINS AS THE WIND WAS MORE FROM
THE S-SE THUS AIDING TO FILTER IN GULF MOISTURE. IN FACT...LOW
CLOUDS AND/OR FOG WERE NOTED ACROSS THE BIG COUNTRY REGION...WHICH
MAY HAVE A CHANCE AT SPREADING TOWARDS THE ROLLING PLAINS AOA
SUNRISE. THE HRRR IS MOST AGGRESSIVE IN THE STRATUS DECK/FOG MAKING
IT AS FAR NW TO KLBB...WITH OTHER SOLUTIONS MAINTAINING THE IT TO
THE LOW ROLLING PLAINS AND PERHAPS THE SRN SOUTH PLAINS. HENCE WILL
BE KEEPING AN EYE ON TRENDS FOR THE NEXT SEVERAL HOURS.
THE STORM SYSTEM OF INTEREST IS AN UA TROUGH DRAPED FROM THE GREAT
BASIN TO ACROSS WRN AZ EARLY THIS MORNING. MOST MODEL SOLUTIONS
AGREE THAT THIS SYSTEM WILL BE RATHER PROGRESSIVE...AS IT IS PROGGED
TO BE ACROSS ERN AZ/WRN NM THIS AFTN TO ACROSS CNTRL NM THIS
EVENING...AND FINALLY ACROSS THE PANHANDLE REGION LATE TONIGHT/EARLY
SUN MORNING...ALL THE WHILE EVOLVING TO MORE OF A CLOSED OFF STATE.
THE ECMWF STILL REMAINS THE OUTLIER WITH IT BEING SLIGHTLY SLOWER
AND FARTHER SOUTH VERSUS THE NAM AND GFS SOLUTIONS. THIS AFTN-
EVENING AS THE SYSTEM DRAWS NEAR...ITS SFC COUNTERPART WILL RESPOND
BY DEEPENING AND THEREFORE PROMOTE A TIGHTENED PRESSURE GRADIENT
WHILST TRANSLATING EAST ACROSS THE CWA. MOS GUIDANCE HINTS AT SFC
WIND SPEEDS OF 15-25 MPH OUT OF THE W-SW...WITH THE BREEZIEST
CONDITIONS NOTED ON THE CAPROCK. OFF THE CAPROCK...SFC WINDS WILL BE
OUT OF THE S-SE. PERSISTENT SWRLY FLOW ALOFT AIDING IN TRANSPORTING
HIGH LEVEL CIRRUS CLOUD COVER WILL BE SLOW TO CLEAR OUT FROM WEST TO
EAST...WHERE IF THERE WERE CLEAR SKIES...WIND CONDITIONS COULD BE A
LOT WORSE. CLOUD COVER WILL BE LAST TO CLEAR OUT ACROSS THE ERN
ZONES GIVEN THE FAVORABLE UPSLOPE WIND COMPONENT.
CONCURRENTLY...A 160 KT 250 MB JET MAX WILL MOVE ACROSS THE
CWA...PROVIDING UL SUPPORT AND ENCOURAGE THE DEVELOPMENT OF SHOWERS
AND THUNDERSTORMS MOVING IN FROM WEST TO EAST. MID-LEVEL INSTABILITY
IS NOT VERY IMPRESSIVE /400-600 J/KG/ BUT THE 0-6 KM BULK SHEAR OF
40-70 KTS AND A SLIGHT COOLING IN THE MID-LEVELS /STEEPENING LAPSE
RATES/ DO SUGGEST SOME THUNDERSTORMS APPROACHING STRONG LEVELS
/HAIL AND WIND THE PRIMARY THREATS/ PARTICULARLY ACROSS THE ROLLING
PLAINS...COINCIDING WITH THE BEST MOISTURE AND MID-LEVEL INSTABILITY.
KEEP IN MIND...IF THE CLOUD COVER HANGS AROUND A LITTLE LONGER THAN
ANTICIPATED ACROSS THE ROLLING PLAINS...THE LITTLE BIT OF MID-LEVEL
INSTABILITY MAY NOT BE ENOUGH TO OVERCOME THE CAPPED ATMOSPHERE AND
THUS STRONG THUNDERSTORMS MAY NOT BECOME REALIZED. THE LLJ KICKING
UP INTO THE 40-50 KT RANGE WILL MAINTAIN STORMS ACROSS THE ROLLING
PLAINS THIS EVENING-TONIGHT WHILST THE REMAINDER OF THE CWA BECOMES
ENVELOPED BY DRY-SLOTTING /W-SW WINDS/. SOUNDING PROFILES INDICATE
THIS SCENARIO RATHER WELL WITH TOP-DOWN MOISTENING OCCURRING THIS
AFTN-EVENING...AND DRYING ENSUING IN THE MID AND UPPER LEVELS BY
TONIGHT. LCL/S ARE A BIT LOW ACROSS THE FAR ROLLING PLAINS WHICH
RAISES CONCERNS FOR A TORNADO RISK. HOWEVER...THE AMOUNT OF 0-6 KM
BULK SHEAR MIGHT BE TOO MUCH OF A GOOD THING...AS IT COULD PREVENT
STORMS FROM MAINTAINING GOOD STRUCTURE.
500 MB HEIGHT FALLS WILL LEAD TO A COOLER ALBEIT STILL UNSEASONABLY
WARM SATURDAY...WITH HIGHS IN THE 60S AND 70S...FOLLOWED BY LOWS IN
THE 30S AND 40S.
.LONG TERM...
COULD SEE A FEW LIGHT RAIN OR SNOW SHOWERS SUNDAY MORNING ACROSS THE
FAR SRN PANHANDLE AS THE CLOSED LOW SLOWLY EJECTS TO THE ENE ACROSS
THE PANHANDLE TO NWRN OKLAHOMA. HOWEVER...MAIN STORY TURNING OUT TO
BE WIND AS TIGHT LOW TO MID LEVEL HEIGHT GRADIENT ON THE S/SW FLANKS
OF THE UPPER LOW WILL LIKELY TRANSLATE INTO AT LEAST 20-30 MPH RANGE
ACROSS MUCH OF THE FCST AREA IN LINE WITH MOS VALUES AS COLD
ADVECTION WILL LIMIT THE POTENTIAL FOR 50 KT MID LEVEL WINDS TO MIX
TO THE SFC.
AFTER SHORT WAVE RIDGING BRINGS A WARMER AND LESS WINDY DAY
MONDAY...ANOTHER UPPER LOW PROGGED TO MOVE ACROSS THE COLORADO
ROCKIES MONDAY NIGHT AND ONTO THE CNTL HIGH PLAINS DURING THE DAY
TUESDAY. MODELS CURRENTLY PROGGING RAPID CYCLOGENESIS SERN COLO/SWRN
KANSAS EARLY TUESDAY WITH A MID LEVEL JET STREAK ON THE ORDER OF 50
TO 70 KTS ROTATING OVER THE SRN HIGH PLAINS DURING THE DAY TUESDAY.
DEEP COLD ADVECTION WILL AGAIN LIMIT POTENTIAL FOR MIXING TO THE
SFC...BUT AGAIN POTENTIAL EXISTS FOR AT LEAST 20-30 MPH TO BE
REALIZED.
BEYOND TUESDAY...A BROAD LONG WAVE UPPER TROUGH OVER THE WRN CONUS
WILL SHIFT EWD TO THE PLAINS WEDNESDAY LEAVING DRY AND UNEVENTFUL
NWLY FLOW OVER THE FCST AREA THROUGH THE END OF THE WEEK. COLD FRONT
OF CANADIAN ORIGIN BEHIND TUESDAYS UPPER LOW WILL BRING COLDER AIR
INTO THE REGION WITH TEMPS FINALLY REVERTING TO BELOW NORMAL
WEDNESDAY AND THURSDAY BEFORE MODERATING TO END THE WEEK.
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
29/07
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION
VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
844 PM EST SUN DEC 13 2015
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL SLOWLY WEAKEN AND PUSH
OFFSHORE OVERNIGHT ALLOWING A RETURN SOUTHERLY FLOW OF LOW LEVEL
MOISTURE TO TAKE PLACE BY EARLY MONDAY. A COLD FRONT WILL APPROACH
FROM THE WEST MONDAY BEFORE SLIDING THROUGH THE AREA MONDAY NIGHT.
WEAK HIGH PRESSURE FOLLOWS THE FRONT BRINGING DRIER WEATHER AND
CONTINUED WARM TEMPERATURES INTO MID WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 815 PM EST SUNDAY...
WARMTH CONTINUES TO ROLL ON IN MID DECEMBER WITH ADDED RECORDS
ESTABLISHED THIS AFTERNOON PER THE CLIMATE SECTION BELOW WITH
ANOTHER MILD OVERNIGHT TO FOLLOW. LATEST EVENING SOUNDINGS SHOW
CONTINUED VERY DRY AIR ALOFT THIS EVENING AHEAD OF THE STRONG
UPPER TROUGH AND ASSOCIATED SURFACE COLD FRONT JUST WEST OF THE
MISSISSIPPI RIVER. HOWEVER SEEING PLENTY OF MID/HIGH CLOUDS SPILL
EAST FROM THE CONVECTION TO THE WEST AND THIS TREND LOOKS TO
PREVAIL OVERNIGHT GIVEN THE STRONG WESTERLY FLOW ALOFT. APPEARS
THIS CANOPY LIKELY TO KEEP THE LID ON WIDESPREAD FOG GIVEN LIMITED
RADIATIVE COOLING AND SUPPORTED BY UNFAVORABLE FORECAST FOG
STABILITY VALUES OFF SOUNDINGS TOWARD DAYBREAK MONDAY. LOOKS LIKE
BEST CHANCE AT FOG WILL BE OVER THE SOUTH AND EAST WHERE CLOUDS
MAY THIN MORE SO KEEPING BETTER COVERAGE THERE.
OTRW EXPECT LOW LEVEL MOISTURE TO GRADUALLY INCREASE OVER THE SW
ONCE THE FLOW TURNS A LITTLE MORE SE LATER ALLOWING SOME PATCHY
LIGHT SHOWERS TO DEVELOP WITHIN A WEAK ISENTROPIC/UPSLOPE REGIME.
LATEST HRRR HOLDS MOST COVERAGE OFF UNTIL AFTER MIDNIGHT AND ONLY
HAS SPOTTY SHOWERS DEVELOPING AT BEST. THUS DELAYING ONSET A BIT
PER DRYNESS AND TRIMMING BACK ON HIGH POPS UNTIL EARLY MONDAY.
LITTLE CHANGE AS WELL TO THE GOING WIND ADVISORY AS APPEARS THE
BEST LOW LEVEL JET ALSO WONT ARRIVE OUT WEST UNTIL AROUND DAYBREAK
WITH STRONGER WINDS POSSIBLE ON THE RIDGES INTO MIDDAY MONDAY.
TEMPS TO STAY MILD UNDER MAINLY CLOUDY SKIES OVERNIGHT WITH MOST
LINGERING IN THE 50S. HOWEVER DO EXPECT THE VALLEYS AND OUTLYING
EASTERN LOCATIONS TO DIP INTO THE 40S BEFORE LIKELY RISING LATE AS
CLOUDS THICKEN MORE AND MIXING PICKS UP.
PREVIOUS DISCUSSION AS OF 345 PM EST SUNDAY...
MAINTAINING THE PATTERN OF BROAD UPPER LEVEL RIDGING ACROSS THE
EASTERN HALF OF THE NATION THIS AFTERNOON...WHILE A DEEP UPPER
LEVEL LOW TRACKS NORTHEAST NEAR THE TEXAS PANHANDLE. IN THE LOW
LEVELS... HIGH PRESSURE IS CENTERED OFF THE CAROLINA COAST...WITH
SOUTH- WESTERLY WINDS ON THE BACKSIDE OF THE HIGH DRAWING WARM
GULF MOISTURE NORTHWARD ACROSS THE OUR AREA. DESPITE THICKENING
HIGH CLOUDS MOVING IN FROM THE WEST AS THE UPPER LOW APPROACHES...
TEMPERATURES ACROSS THE AREA WERE ABLE TO REBOUND AFTER
WIDESPREAD FOG LINGERED INTO LATE MORNING...REACHING INTO THE MID
60S TO THE LOW 70S.
WIND SPEEDS WILL INCREASE FROM WEST TO EAST HEADING INTO LATE
EVENING AS THE COLD FRONT ASSOCIATED WITH THE UPPER LEVEL LOW
APPROACHES FROM THE WEST...CAUSING THE PRESSURE GRADIENT ACROSS
THE REGION TO TIGHTEN. WEATHER FORECAST MODELS ARE IN DECENT
AGREEMENT THAT THE LOW LEVEL JET WILL RAMP UP TO AROUND 60 MPH
TOWARD DAWN MONDAY ACROSS THE MOUNTAINS. WITH SOUTHERLY WINDFLOW
IN PLACE...DOWNSLOPING ON THE WEST SIDE OF THE RIDGES FROM THE
HIGHLANDS OF NORTH CAROLINA INTO EXTREME SOUTHEAST WEST VIRGINIA
WILL BRING SOME OF THE STRONGER JET WINDS TO THE SURFACE. AS
SUCH...WILL CONTINUE WITH THE WIND ADVISORY IN EFFECT FROM MIDNIGHT
TONIGHT THROUGH 7 PM MONDAY.
BELIEVE THIS WILL BE ONE OF THOSE NIGHTS WHERE OVERNIGHT LOWS
OCCUR EARLIER IN THE NIGHT...AND THEN COOLING WILL SLOW/STOP AS THE
WINDSPEEDS INCREASE TOWARD DAWN. WHERE FOG WAS WIDESPREAD
THIS MORNING...BELIEVE IT WILL BE MORE SPOTTY IN NATURE LATE
TONIGHT DUE TO INCREASED CLOUDS...FOUND MORE SO ACROSS THE
SOUTHSIDE WHERE WINDSPEEDS WILL REMAIN LOWER. INSTEAD...EXPECT LOW
CLOUDS TO INCREASE ACROSS THE MOUNTAINS/FOOTHILLS AFTER
MIDNIGHT...WITH ONLY POCKETS OF LIGHT RAIN OR DRIZZLE POSSIBLE
ALONG THE RIDGES. OVERNIGHT LOWS WILL FALL INTO THE UPPER 40S TO
THE MID 50S.
SHOWER ACTIVITY WILL INCREASE AFTER SUNRISE AS THE COLD FRONT PASSES
EAST OF THE MISSISSIPPI RIVER TOWARD THE APPALACHIANS. EXPECT MAINLY
SHOWER ACTIVITY THROUGH LATE MORNING...WHEN THE MAIN UPPER LEVEL
SUPPORT WILL ARRIVE ALONG OUR WESTERN BORDER...TRIGGERING A SOLID
LINE OF RAIN SHOWERS. DO NOT SEE MUCH INSTABILITY TO SUPPORT THE
POTENTIAL FOR THUNDER WITH THIS LINE...ALTHOUGH IT CANNOT BE
ENTIRELY RULED OUT. HOWEVER...LOW LEVEL SHEAR/HELICITY WILL BE
STRONG ENOUGH THAT SOME OF THE STRONGER SHOWERS WILL STILL BE
CAPABLE OF PRODUCING LOCALLY STRONG WIND GUSTS. THE COLD FRONT WILL
FINALLY ENTER OUR SOUTHEAST WEST VIRGINIA/MOUNTAIN EMPIRE COUNTIES
DURING EARLY AFTERNOON...AND WILL EXIT OUR AREA TO THE EAST SHORTLY
BEFORE MIDNIGHT. FRONTAL PASSAGE WILL BRING WITH IT A WESTERLY WIND
SHIFT THAT WILL BRING ONLY SLIGHTLY COOLER AIR.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 236 PM EST SUNDAY...
NOT TOO MUCH CHANGE FROM PREVIOUS FORECAST THIS PERIOD. HAVE
INCREASED WIND GUSTS FOR LATE MONDAY NIGHT/EARLY TUESDAY MORNING AS
ANOTHER PIECE OF HIGHER WINDS AT 8H MOVING ACROSS THE AREA...WITH
6HR PRESSURE RISES OF 4-7MB. THINK AT THIS POINT THAT WIND ADVISORY
LEVELS WILL BE LIMITED TO A FEW HIGHER RIDGES LIKE MT ROGERS...SO
NOT GOING TO EXTEND THE WIND ADVISORY CURRENTLY IN EFFECT...WHICH IS
MAINLY FOR THE STRONG WINDS AHEAD OF THE FRONT.
WE SHOULD SEE THE FRONT CLEAR THE PIEDMONT BY MIDNIGHT....WITH
DRYING TAKING PLACE PRIOR TO THIS. THERE IS NO SUBSTANTIAL AIRMASS
CHANGE BEHIND IT...CONTINENTAL...SO LOWS TUESDAY MORNING WILL STILL
BE ABOVE NORMAL...FROM THE LOWER TO MID 40S MOUNTAINS...TO NEAR 50
EAST.
TUESDAY...SHORTWAVE RIDGE PUSHES ACROSS THE SOUTHEAST TO THE
MIDWEST. FAST FLOW ALOFT MAY BRING SOME CIRRUS TO OUR AREA...WITH
LINGERING STRATOCU IN THE WV MTNS. WINDS WILL BE GUSTY EARLY...THEN
WEAKENING BY DUSK. A MILD DAY WITH HIGHS FROM THE MID TO UPPER 50S
WEST...TO THE MID 60S EAST.
HIGH PRESSURE BUILDS OVERHEAD TUESDAY NIGH ALLOWING FOR FALLING
TEMPERATURES IN THE VALLEYS...WITH RETURN FLOW KICKING IN LATE OVER
THE WRN RIDGES. WITH MAINLY CLEAR SKIES TEMPS SHOULD FALL TO THE
LOWER TO MID 30S IN THE VALLEYS...WITH UPPER 30S/NEAR 40 ELSEWHERE.
WEDNESDAY...HIGH PRESSURE SHIFTS OFFSHORE WITH SW FLOW INCREASING
ALOFT. SHOULD SEE INCREASING CLOUDS LATE IN THE DAY...BUT ANY
SHOWERS WILL HOLD OFF UNTIL WEDNESDAY NIGHT...WITH BEST CONVERGENCE
OF MOISTURE SHIFTING FROM THE SOUTHERN APPALACHIANS AT MIDNIGHT TO
THE VIRGINIA PIEDMONT BY 12Z THU. BEFORE THE CLOUDS MOVE IN
WEDNESDAY WE SHOULD SEE TEMPS WARM INTO UPPER 50S TO MID 60S. WITH
THE HIGH OVER THE NORTHEAST TO MID ATLANTIC...THE SF FLOW WILL BE
MORE OUT OF THE SE WHICH MAY KEEP THINGS COOLER. POTENTIAL DOES
EXIST THAT IF THE FLOW CAN TURN AROUND MORE TO THE SOUTH OR
SOUTHWEST BEFORE THE CLOUDS ENTER THE PICTURE...TEMPS MAY RISE MORE
INTO THE MID 60S OUT EAST.
WEDNESDAY NIGHT LOOKS SOMEWHAT MILD WITH CLOUDS BUT RAIN SHOWERS
SHOULD LOWER READINGS TO THE DEWPOINTS...WITH MOST LOCATIONS HAVING
LOWS IN THE MID 40S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EST SUNDAY...
THE LONG RANGE FEATURES THE FIRST BIG ARCTIC PUSH INTO THE REGION
FOR QUITE SOME TIME...ALTHOUGH THE COLD AIR WONT STICK AROUND LONG.
THE PERIOD STARTS WARM WITH +11C 850MB TEMPS AHEAD OF AN APPROACHING
COLD FRONT AND DIGGING TROUGH. EXPECT SHOWERS AHEAD OF THE FRONT
THURSDAY INTO FRIDAY. EXACTLY HOW MUCH RAIN WILL FALL ACROSS OUR
REGION WILL DEPEND ON HOW DEEP THE TROUGH TO OUR WEST DIGS...FOR
RIGHT NOW IT LOOKS LIKE AREAS ALONG AND EAST OF THE BLUE RIDGE WILL
SEE THE MOST RAIN. THE COLD FRONT WILL PUSH THROUGH THE AREA
SOMETIME FRIDAY MORNING PUSHING THE RAIN OUT WITH IT.
BEHIND THE COLD FRONT TEMPS WILL FALL QUICKLY. AS THE TROUGH SWINGS
THROUGH THE REGION 850MB TEMPS WILL DROP DOWN TO -10 TO -12C BY
SATURDAY MORNING. WITH SUFFICIENT LOW LEVEL MOISTURE...THERE IS A
GOOD CHANCE WE WILL SEE NORTHWEST FLOW SNOW SHOWERS ALONG THE
FAVORED WESTERN RIDGES FRIDAY NIGHT AND THROUGH THE DAY SATURDAY.
HIGH TEMPS SATURDAY WILL RUN 5-10 DEGREES BELOW NORMAL WITH MANY
MOUNTAIN LOCATIONS STRUGGLING TO REACH THE FREEZING MARK.
BY SUNDAY THE TROUGH MOVES OFF TO OUR EAST AND ALONG WITH IT THE
COLD AIR. STRONG HIGH PRESSURE BUILDS IN AND WILL MOVE JUST TO OUR
EAST SUNDAY NIGHT/MONDAY MORNING. THE W/SW FLOW WILL ONCE AGAIN PULL
WARM AIR INTO THE REGION AND WE RETURN TO ABOVE NORMAL TEMPS.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
AS OF 630 PM EST SUNDAY...
A COLD FRONT WILL APPROACH FROM THE WEST TONIGHT INTO
MONDAY...CAUSING THE PRESSURE GRADIENT TO TIGHTEN AND SOUTHERLY
WINDS TO INCREASE...ESPECIALLY ACROSS THE MOUNTAINS. THE LOW LEVEL
JET WILL RAMP UP TO AROUND 50KTS NEAR KBLF...AND DOWNSLOPING IN THE
NEARBY TERRAIN MAY RESULT IN OCCASIONAL 25 TO 30KT GUSTS AT THE
AIRPORT TOWARD DAWN. PILOTS SHOULD WATCH FOR LOW LEVEL WINDS
SHEAR LATE TONIGHT IN TO MONDAY MORNING.
EXPECT A RETURN OF LOW MVFR/IFR CONDITIONS AS STRATUS DEVELOPS
ACROSS THE MOUNTAINS AND FOOTHILLS BEGINNING 14/09Z. THE TAF SITE
WITH THE BEST CHANCE FOR IFR CONDITIONS IS KDAN WITH LOW CLOUDS AND
FOG BECAUSE THE LIGHTEST WINDS. MOISTURE WILL LIFT NORTHWARD FROM
SOUTHWEST TO NORTHEAST TONIGHT INTO MONDAY MORNING. ALONG THE
SOUTHERN BLUE RIDGE WILL HAVE THE GREATEST OPPORTUNITY FOR SHOWERS
AND LIGHT RAIN OVERNIGHT.
AS THE COLD FRONT ENTERS EASTERN KENTUCKY AND TENNESSEE MONDAY
MORNING...LOW MVFR/IFR CONDITIONS WILL DEVELOP ACROSS ALL OF THE
REGION. LOW MVFR/IFR CONDITIONS WILL REMAIN ACROSS THE FORECAST AREA
THROUGH THE AFTERNOON AS RAIN SHOWERS PASS ACROSS AHEAD OF THE
APPROACHING COLD FRONT. THE COLD FRONT WILL MOVE EAST MONDAY INTO
MONDAY NIGHT AND REACHING THE ATLANTIC COAST TUESDAY MORNING. RAIN
MAY BE HEAVY AT TIMES...CAUSING VISIBILITIES TO TEMPORARILY LOWER TO
1SM OR LESS. IN ADDITION... CAN NOT RULE OUT GUSTY WINDS WITH THE
STRONGER SHOWERS. STRONG WEST TO NORTHWEST WINDS ARE POSSIBLE BEHIND
THE COLD FRONT MONDAY AND MONDAY NIGHT.
MEDIUM CONFIDENCE ON CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
.EXTENDED AVIATION DISCUSSION...
WIDESPREAD VFR UNDER DIMINISHING WINDS WILL OCCUR UNDER WEAK HIGH
PRESSURE TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT WITH AN
ASSOCIATED AREA OF LOW PRESSURE LOOKS TO BRING MORE IN THE WAY OF
WIDESPREAD SUB- VFR IN RAIN AND LOWER CIGS LATE WEDNESDAY NIGHT
INTO THURSDAY.
&&
.CLIMATE...
AS OF 745 PM EST SUNDAY...
RECORD HIGH TEMPERATURES WERE SET TODAY (12/13) AT BOTH DANVILLE
VA AND BLUEFIELD WV. SEE THE LATEST WBCRERRNK FOR ADDED DETAILS.
RECORD HIGH TEMPERATURES FOR....
DEC 14
BLACKSBURG | 70 IN 1984
BLUEFIELD | 68 IN 1984
DANVILLE | 74 IN 1948
LYNCHBURG | 70 IN 1948
ROANOKE | 73 IN 1927
RECORD WARM MINIMUM TEMPERATURES FOR...
DEC 14
BLACKSBURG | 49 IN 1991
BLUEFIELD | 53 IN 1984
DANVILLE | 53 IN 1991
LYNCHBURG | 55 IN 1901
ROANOKE | 60 IN 1927
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM EST MONDAY FOR
VAZ007-009-010-015.
NC...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM EST MONDAY FOR
NCZ001-018.
WV...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 7 PM EST MONDAY FOR
WVZ042.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH/NF
SHORT TERM...WP
LONG TERM...CF
AVIATION...KK/NF
CLIMATE...CF/DS/JH/RAB/WP
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
220 PM MST SAT DEC 12 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 220 PM MST SAT DEC 12 2015
LATEST INFRARED SATELLITE IMAGERY SHOWING WARMING CLOUD TOPS OUT
WEST ACROSS CARBON AND ALBANY COUNTIES THIS AFTERNOON. THE EASTERN
BAND OF LIFT CONTINUES TO SHOW COOLING CLOUD TOPS THAT CORRESPOND
PRETTY WELL WITH THE BANDED SNOW BEING OBSERVED ON RADAR IMAGERY.
LATEST HRRR GUIDANCE SHOWING BAND SHIFTING EAST AND NORTHEAST AS
THE EVENING PROGRESSES.
WENT AHEAD AND CANCELLED WINTER HEADLINES FROM THE LARAMIE RANGE
WEST. ROADS LOOK PRETTY GOOD OUT THAT WAY...THOUGH WITH LATE DAY
EARLY EVENING COOL DOWN...COULD SEE THESE ROADS BECOMING SLICK
WITH BLACK ICE. AS FOR THE ADVISORIES FROM CHEYENNE EAST...KEPT
THEM GOING AS SCHEDULED...WITH NO CHANGES EXPECTED.
700MB WINDS BEGIN PICKING UP SUNDAY AFTERNOON AS THE UPPER RIDGE
AXIS MOVES INTO EASTERN WYOMING. GFS WINDS NOT AS STRONG AS THEY
WERE PREVIOUS FOR SUNDAY...BUT STILL REACHING 45KTS SUNDAY NIGHT
INTO MONDAY MORNING. CONTINUED SOME BLOWING SNOW OUT WEST FOR THE
WIND PRONE AREAS. DEPENDING ON HOW STRONG THESE WINDS GET...MAY
NEED A BLOWING SNOW ADVISORY FOR THE ARLINGTON AREA SUNDAY NIGHT
INTO MONDAY.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 220 PM MST SAT DEC 12 2015
THE UPPER RIDGE IN THE WAKE OF THE WEEKEND STORM SYSTEM MOVES
QUICKLY EAST ACROSS OUR AREA MONDAY AS A VIGOROUS AMPLIFYING UPPER
TROUGH MOVES EAST ACROSS NEVADA. BOTH THE GFS AND THE ECMWF CLOSE
OFF AND DEEPEN THE UPPER LOW AS IT MOVES ACROSS COLORADO TUESDAY
INTO WEDNESDAY. AS HAS BEEN TYPICAL OF THIS WINTER SEASON SO
FAR...THE GFS IS THE STRONGEST DYNAMICALLY WITH THE NEXT STORM
SYSTEM...BUT THE CONCENSUS AMONGST THE MODELS IS THAT THE NEXT
SYSTEM WILL COME OUT FARTHER NORTH THAN THE SYSTEM WE ARE WORKING
TODAY. ALSO GIVEN THAT LOW IS PROJECTED TO BE DEEPENING JUST TO
OUR SOUTH...IT IS ALSO ADVERTISED TO SLOW DOWN AS IT MOVES ACROSS
EASTERN INTO WESTERN KANSAS. THE MAIN SNOW EVENT LOOKS TO BE FROM
MONDAY NIGHT THROUGH WEDNESDAY MORNING WITH ENOUGH DURATION TO
EXPECT HIGHER TOTALS IN THE SOUTH LARAMIE RANGE AND JUST TO THE
EAST. IT IS TOO EARLY RIGHT NOW TO GET SPECIFIC WITH SNOWFALL
AMOUNTS WITH ANY PRECISION...HOWEVER IF THE MODEL TRENDS HOLD WE
COULD EXPECT HIGHER IMPACTS TO TRAVEL ACROSS SOUTHEASTERN WYOMING
AND THE WESTERN NEBRASKA PANHANDLE. LATER FORECASTS WILL REFINE
POTENTIAL IMPACTS AND TIMING ON THIS NEXT SNOW EVENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1053 AM MST SAT DEC 12 2015
IFR FLIGHT CATEGORY BECOMING MORE WIDESPREAD IN LIGHT TO MODERATE
SNOW FROM CHEYENNE EAST ACROSS THE WESTERN NEBRASKA PANHANDLE AT
THIS HOUR. WILL KEEP CHEYENNE...SCOTTSBLUFF...ALLIANCE AND CHADRON
IN IFR FORECAST CATEGORY THROUGH MID EVENING AND THEN TREND
VISIBILITY UP TOWARDS LATE EVENING INTO THE EARLY MORNING HOURS.
DIDNT CARRY SNOW AT LARAMIE EVEN THOUGH A BRIEF SHOW SHOWER IS
POSSIBLE THIS AFTERNOON...BUT VFR SHOULD PREVAIL THERE AND RAWLINS
THROUGH MUCH OF THE FORECAST PERIOD WITH THE EXCEPTION OF A BRIEF
PERIOD OF MVFR CEILINGS AT LARAMIE THIS AFTERNOON.
&&
.FIRE WEATHER...
ISSUED AT 220 PM MST SAT DEC 12 2015
MINIMAL FIRE WEATHER CONCERNS AS AREAS ACROSS EXTREME SOUTHERN
WYOMING HAVE SEEN ACCUMULATING SNOW FROM THIS PAST LOW PRESSURE
SYSTEM. STRONG WINDS STILL POSSIBLE SUNDAY LATE AFTERNOON THROUGH
THE EVENING HOURS...BUT TEMPERATURES WILL BE COLD AND WILL KEEP
HUMIDITIES IN CHECK. ANOTHER WINTER STORM SYSTEM POSSIBLE MONDAY
NIGHT INTO TUESDAY THAT COULD BRING WIDESPREAD MODERATE SNOW
ACCUMULATIONS ACROSS MUCH OF SOUTHEAST WYOMING AND NEBRASKA
PANHANDLE.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR WYZ107-
108-118-119.
NE...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR NEZ002-
003-019>021-054-055-095-096.
&&
$$
SHORT TERM...GCC
LONG TERM...JG
AVIATION...JG
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS RENO NV
1005 PM PST SUN DEC 13 2015
.UPDATE...
MOST BANDED PRECIPITATION HAS DIMINISHED ACROSS THE TAHOE BASIN
THROUGH PORTIONS OF WESTERN NEVADA. AS SUCH HAVE ALLOWED THE
WINTER STORM WARNING TO EXPIRE ACROSS THE TAHOE BASIN AND HAVE
CANCELLED THE WINTER WEATHER ADVISORY FOR THE GREATER RENO-CARSON
CITY-MINDEN REGION. A FEW LINGERING LIGHT SNOW SHOWERS WILL BE
POSSIBLE OVER THE NEXT FEW HOURS SOUTH OF HWY 50 THROUGH THE TAHOE
BASIN AND ALSO SOUTH OF MINDEN. FUENTES
&&
.PREVIOUS DISCUSSION... /ISSUED 710 PM PST SUN DEC 13 2015/
UPDATE...
JUST A QUICK UPDATE TO ALLOW THE WINTER STORM WARNING AND WINTER
WEATHER ADVISORY TO EXPIRE FOR PORTIONS OF NORTHEAST CALIFORNIA
INCLUDING LASSEN COUNTY AND THE SURPRISE VALLEY. SNOWFALL HAS
DIMINISHED ACROSS THESE AREAS BUT A FEW SNOW SHOWERS ARE POSSIBLE
OVER THE NEXT FEW HOURS THROUGH THE SIERRA VALLEY WITH AN
ADDITIONAL INCH OF ACCUMULATION POSSIBLE.
ELSEWHERE, A NW-SE ORIENTED BAND OF SNOWFALL CONTINUES FROM ABOUT
PORTOLA THROUGH SOUTH RENO AND TO JUST NORTH OF WALKER LAKE. THIS
BAND WILL CONTINUE TO TRACK SOUTH TONIGHT WITH AN ADDITIONAL 1-2
INCHES OF ACCUMULATION POSSIBLE IN HEAVIER PORTIONS OF THE BAND.
MOTORISTS SHOULD STAY CAUTIOUS OF ICE FORMING ON UNTREATED ROAD
SURFACE TONIGHT ESPECIALLY IN THE RENO AREA. NDOT ROAD CAMS
INDICATE THAT THE LIGHT SNOWFALL WE RECEIVED EARLIER HAS MELTED.
THIS PRESENTS A THREAT TO FORM ICE ON ROADS TONIGHT AS
TEMPERATURES DIP BELOW FREEZING. FUENTES
PREVIOUS DISCUSSION... /ISSUED 110 PM PST SUN DEC 13 2015/
SYNOPSIS...
A FAST MOVING STORM WILL BRING MODERATE TO HEAVY SNOW SOUTH OF
HIGHWAY 50 TONIGHT THEN EXIT TO THE EAST BY MONDAY MORNING.
SIGNIFICANT TRAVEL IMPACTS AND DELAYS ARE EXPECTED FOR THE SIERRA
THROUGH TONIGHT, WITH SLICK ROADS ALSO POSSIBLE TONIGHT IN WESTERN
NEVADA. A DRYING TREND WILL FOLLOW WITH COLD TEMPERATURES THROUGH
MIDWEEK. A POTENTIAL FOR A WINTER STORM NEXT WEEKEND EXISTS BUT
THERE IS LOW FORECAST CERTAINTY.
SHORT TERM...
SO THIS STORM HAS TAKEN ON A DIFFERENT CHARACTERISTIC THIS
AFTERNOON AS THE SFC FRONT HAS SPED UP FAR MORE THAN THE MOST
RECENT NUMERICAL MODEL GUIDANCE WOULD SUGGEST. THIS HAS RESULTED
IN HEAVY PRECIPITATION MAKING ITS WAY INTO WESTERN NEVADA WELL
AHEAD OF THE COLDEST AIR AND CAUSING PCPN INTENSITY TO SLOW IN THE
NORTHERN SIERRA EARLIER THAN FORECAST. ALL OF THIS CAN SEVERELY
IMPACT THE AMOUNT OF QPF AND SNOW THAT WE RECEIVE IN THIS STORM.
THERE IS A GLIMMER OF HOPE THAT MANY AREAS...ESPECIALLY EAST OF
THE SIERRA...COULD STILL PICK UP APPRECIABLE SNOW THIS EVENING AND
OVERNIGHT. MOST OF THE MODELS PERSIST IN DEVELOPING A BAND OF SNOW
OVER WESTERN NEVADA AND THE NORTHERN SIERRA LATER THIS EVENING AS
A SECONDARY WAVE MOVES THROUGH THE WEST NORTHWEST FLOW IN THE COLD
SECTOR OF THE UPPER TROUGH. THIS WAS THE REASON FOR EXTENDING THE
ADVISORIES FOR MONO COUNTY AND THE SIERRA FRONT AND ADDING AND
ADVISORY TO SOUTHERN LYON AND MINERAL COUNTIES. WE HAVE TO
CAUTION...HOWEVER...THAT CONFIDENCE IN THIS SOLUTION AND SNOW
AMOUNTS REMAINS QUITE LOW. WE DO THIS TO GIVE TRAVELERS A HEADS
UP THAT ROAD CONDITIONS EAST OF THE SIERRA COULD DETERIORATE
THROUGH THE EVENING.
GUSTY WINDS WERE AN ISSUE EARLIER IN THE DAY...BUT THESE HAVE
DECREASED AND ALL OF THE WIND ADVISORIES AND THE WARNING WILL BE
DROPPED.
AS THE UPPER LOW MOVES EAST MONDAY AND MONDAY NIGHT WRAP AROUND
SHOWERS ARE POSSIBLE...BUT SHOULD PRODUCE LIMITED SNOW AMOUNTS.
THE BIGGER STORY EARLY IN THE WEEK WILL BE MUCH COLDER
TEMPERATURES WITH HIGHS GENERALLY IN THE 30S IN THE VALLEYS AND
THE UPPER 20S TO NEAR 30 IN THE SIERRA. BY WEDNESDAY THESE
TEMPERATURES BEGIN TO WARM BUT WE ALSO SEE THE SIGNS OF WEAK OVER
RUNNING PCPN TRYING TO DEVELOP NEAR THE OREGON BORDER WEDNESDAY
NIGHT. 20
LONG TERM...(THURSDAY-SUNDAY)...
SO EVEN THOUGH ON THE BIG PICTURE THE LONG RANGE GUIDANCE HAS A
SIMILAR FLOW PATTERN OVER THE WESTERN US, THERE ARE SIGNIFICANT
DIFFERENCES IN STORM POTENTIAL LEADING TO FAIRLY LOW FORECAST
CONFIDENCE.
THURSDAY INTO THURSDAY NIGHT - STRONG WARM ADVECTION SCENARIO OVER
THE REGION LEADING TO INCREASED CHANCES OF PRECIP NORTH OF I-80. GFS
IS MUCH MORE ROBUST WITH QPF COMPARED TO ECMWF, SO HAVE MAINTAINED
MODERATE CHANCE POPS. IF GFS SCENARIO PANS OUT, FORECAST SOUNDINGS
AND INTENSITY OF WARM ADVECTION SUPPORT HEAVY SNOWS ACROSS MODOC
COUNTY INTO NW NEVADA. DEFINITELY WORTH WATCHING NOT ONLY FOR THIS
OUTCOME BUT ALSO POTENTIAL FOR PRECIP TO DROP FURTHER SOUTH THAN
CURRENTLY PROJECTED.
SATURDAY-MONDAY - WILL MAINTAIN LOW CHANCES FOR RAIN/SNOW MAINLY IN
THE SIERRA FOR THIS PERIOD AS THERE ARE MAJOR DIFFERENCES IN THE
GUIDANCE. GFS WOULD YIELD 2-3 BACK TO BACK MODERATE WINTER STORMS
WITHIN A PROGRESSIVE NW FLOW ALOFT, WHILE ECMWF DIGS THE STORM TRACK
FURTHER SOUTH INTO SOCAL SAT/SUN BUT STILL HAS A STORM INTO OUR
REGION MONDAY. EITHER WAY, THIS PATTERN BEARS WATCHING SINCE NEXT
WEEKEND WE`LL BE GETTING INTO THE PEAK PRE-CHRISTMAS TRAVEL PERIOD
WITH ENHANCED IMPACT POTENTIAL. CS
AVIATION...
TRICKY FORECAST WITH ONGOING WINTER STORM AND RAIN/SNOW TRANSITION
IN THE WESTERN NV VALLEYS (RNO/CXP). OVERALL FORECAST CONFIDENCE IN
THE TAFS IS ONLY LOW TO MEDIUM.
LATEST HRRR GUIDANCE AND UPSTREAM RADAR IMAGERY SUGGESTS CONTINUED
+SN IN THE SIERRA (TVL/TRK) THROUGH ~23Z BEFORE TRANSITIONING TO
SNOW SHOWERS. STRONG WIND AND SNOW AT MMH RIGHT NOW, EXPECTED TO
CONTINUE THROUGH ~3Z BEFORE FADING TO SNOW SHOWERS. NO DOUBT THERE
WILL BE SNOW ACCUMULATION IMPACTS TO RUNWAYS IN THE SIERRA, WITH
IFR/LIFR CONDITIONS.
IN WESTERN NV (RNO/CXP) STRONG S/SW WINDS WITH WIND SHEAR ON
APPROACH AND TURBULENCE ALOFT CONTINUE ~0Z BEFORE SWITCHING TO THE
W/NW AS COLD FRONT MOVES INTO THE REGION. RAIN WILL SWITCH TO
RAIN/SNOW MIX OR PERHAPS ALL WET SNOW BY 22Z BUT RUNWAY
ACCUMULATIONS HIGHLY UNLIKELY DUE TO WARM/WET GROUND AND A QUICK
TRANSITION TO SHOWERS. THIS EVENING, NAM/GFS GUIDANCE SHOW A
SECONDARY BAND OF SNOW DEVELOPING MAINLY SOUTH OF RNO THAT COULD PUT
DOWN 1-2" ACCUMULATIONS AT CXP AND NEARBY AIRFIELDS SUCH AS
NFL/HTH/YERINGTON. CONFIDENCE IN THIS FEATURE FORMING IS ONLY
LOW-MEDIUM, SO THERE`S A CHANCE IT MAY NOT HAPPEN AT ALL BUT
ENOUGH OF A RISK TO WARRANT MENTION. THE BAND OF SNOW COULD FORM
FAR ENOUGH NORTH TO AFFECT RNO BUT UNCERTAIN.
FOR MONDAY, COLD AIR OVERSPREADS THE REGION WITH NORTHERLY FLOW
ALOFT. STRONG GUSTY WINDS LIKELY IN FAVORED AREAS FOR NORTH FLOW
SUCH AS HTH/BIH/TPH. SCT-BKN VFR TO MVFR CEILINGS POSSIBLE
THROUGHOUT THE DAY WITH A FEW LIGHT SNOW SHOWERS IN THE SIERRA. CS
REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING NVZ005.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 8 AM PST
MONDAY NVZ001.
WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY NVZ003.
CA...WINTER STORM WARNING UNTIL 7 PM PST THIS EVENING CAZ071.
WINTER WEATHER ADVISORY UNTIL 7 PM PST THIS EVENING CAZ070.
WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY CAZ073.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ072.
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 8 AM PST MONDAY NVZ001.
WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY NVZ003.
CA...WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY CAZ073.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ072.
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 8 AM PST MONDAY NVZ001.
CA...WINTER WEATHER ADVISORY UNTIL 4 AM PST MONDAY CAZ073.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
343 AM EST MON DEC 14 2015
.SHORT TERM /TODAY THROUGH TUESDAY/...
NARROW LINE OF CONVECTION WITH NO OBSERVABLE CG OR TOTAL LIGHTNING
CONTINUING TO TRAVEL EAST AT 20KTS AND SHOULD ARRIVE IN NW CORNER OF
STATE AROUND 6AM. HAVE TIGHTENED UP POP GRADIENTS AND TIMING BASED
ON 2-RUN TIME-LAGGED ENSEMBLE HRRR AND LOCAL HIRES MODEL GUIDANCE.
COULD SEE SOME SCT -SHRA AHEAD OF LINE BUT COVERAGE APPEARS TO BE 10-
20PCT BASED ON RADAR TRENDS. WITH 850-500MB MEAN RH DIPPING BELOW
10PCT BEHIND FRONT/CONVECTIVE LINE...EXPECT RAPID CLEARING OF CLOUDS
THIS AFTERNOON. GUIDANCE BLEND WITH MAX TEMPS IN THE UPPER 60S TO
UPPER 70S LOOKS GOOD. REST OF SHORT TERM PERIOD LOOKS CLEAR WITH
SW FLOW ALOFT CONTINUING AND ABOVE NORMAL TEMPS. NO WEATHER IMPACTS.
SNELSON
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD STARTS OFF AS DRY BUT ALREADY SOME MODEL
DIFFERENCES EMERGE. BOTH THE GFS AND ECMWF HAVE FRONTAL BOUNDARY
ACROSS THE NORTHERN GULF AND INTO THE PANHANDLE OF FLORIDA BY 12Z
WED BUT THE GFS IS MORE AGGRESSIVE WITH ITS DEEP LAYER MOISTURE
TRANSPORT NORTHWARD. GFS SEEMS A LITTLE FAST AT THIS POINT AND
HAVE FAVORED THE ECMWF AND KEPT POPS SOUTH OF THE AREA INITIALLY.
REGARDLESS OF THE MODEL OF CHOICE...BY THE END OF THE DAY
WED...LOW PRESSURE FORMING OFF THE COAST OF LOUISIANA ALONG WITH
MODERATE ISENTROPIC ASCENT SHOULD ALLOW FOR THE DEVELOPMENT OF
WIDESPREAD LIGHT TO MODERATE RAIN. ALTHOUGH WITH THIS SETUP
SURFACE INSTABILITY WILL BE LITTLE TO NONE...40 KTS OF ISENTROPIC
FLOW ALONG WITH MARGINAL MID LEVEL LAPSE RATES SHOULD RESULT IN ELEVATED
CONVECTION FOR ALL OF CENTRAL AND MOST OF NORTH GEORGIA.
HAVE CONTINUED THE HIGH POPS IN THE GRIDS AS WELL GIVEN THE
CONSISTENCY OF THE MODEL DEPICTIONS WITH CATEGORICAL FOR MOST
AREAS. LOW LIFTS NORTH OF THE AREA BY 12Z THU WITH SOUTHERLY FLOW
DEVELOPING FOR THE SOUTHEAST CORNER. SHOULD SEE SOME SURFACE
INSTABILITY AS A RESULT AND WITH DECENT SHEAR VALUES...WILL NEED
TO MONITOR EVOLUTION OF THIS SYSTEM CLOSELY.
FRONT MOVES THROUGH BY THU NIGHT WITH A SECONDARY DRY FRONT MOVING
THROUGH ON FRIDAY. THIS SHOULD FINALLY BRING SOME COOLER TEMPS TO
THE AREA BUT MAY BE ONLY GOOD ENOUGH TO GET US BACK TO CLIMO OR
JUST BELOW FOR A DAY OR TWO BEFORE MODERATION TAKES PLACE.
DEESE
&&
.AVIATION... 06Z UPDATE... PRIMARY CONCERNS ARE TIMING OF IFR
CIGS NEXT FEW HOURS AND SHRA LATER THIS MORNING. WITH THICK
CIRRUS...AGAIN LOW STRATUS SLOW TO FORM. AS LINE OF SHRA
APPROACHES...SHOULD SEE STRATUS FILL IN QUICKLY. SHRA EXPECTED
14-17Z AT ATL METRO AIRPORTS. COVERAGE OF SHRA EXPECTED TO
DECREASE STEADILY DURING THE DAY...SO TEMPO USED AT KMCN. SFC
WINDS WILL SWITCH TO SW AS LINE PASSES. GUSTS TO 20-22KTS POSSIBLE
ALONG AND AHEAD OF SHRA.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON IFR CIGS DEVELOPING.
HIGH CONFIDENCE ON ALL OTHER ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 69 48 70 44 / 90 0 0 5
ATLANTA 69 48 69 47 / 80 0 0 5
BLAIRSVILLE 64 43 66 38 / 80 0 0 5
CARTERSVILLE 68 44 67 41 / 90 0 0 5
COLUMBUS 70 46 72 50 / 80 0 0 5
GAINESVILLE 67 48 67 45 / 80 0 0 5
MACON 73 46 72 47 / 80 10 0 5
ROME 66 42 67 40 / 90 0 0 5
PEACHTREE CITY 69 44 70 43 / 80 0 0 5
VIDALIA 76 54 74 54 / 50 10 0 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 7 AM EST THIS MORNING FOR THE FOLLOWING
ZONES: CATOOSA...CHATTOOGA...DADE...FANNIN...FLOYD...GILMER...
GORDON...LUMPKIN...MURRAY...TOWNS...UNION...WALKER...WHITE...
WHITFIELD.
&&
$$
SHORT TERM...SNELSON
LONG TERM....DEESE
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
217 AM EST MON DEC 14 2015
.SYNOPSIS...
ISSUED AT 153 AM EST MON DEC 14 2015
RAIN WILL OVERSPREAD THE AREA EARLY TODAY AS A STRONG SYSTEM
APPROACHES AND MOVES INTO THE UPPER GREAT LAKES REGION.
TEMPERATURES WILL BE FALLING TODAY AS COOLER AIR SPREADS OVER THE
AREA BEHIND A COLD FRONT. HOWEVER...TEMPERATURES WILL STILL BE
MILD UNTIL THURSDAY WHEN A STRONGER COLD FRONT PASSES. LOWS WILL
DROP WELL BELOW FREEZING BY FRIDAY MORNING.
&&
.UPDATE...
ISSUED AT 714 PM EST SUN DEC 13 2015
MODEST UPDATE TO CUT BACK/SLOW DOWN POPS FOR THE OVERNIGHT
PERIOD...MAINLY IN OUR SOUTHEAST HALF. INITIAL WING OF 295K
ISENTROPIC ASCENT CURRENTLY LIFTING NORTH AND EXPECT A RELATIVE
LULL IN STEADIER PRECIP FOR MOST OF OUR AREA THROUGH MUCH OF
TONIGHT AS THIS ACTIVITY LIFTS NORTH. A FEW LINGERING SHOWERS
POSSIBLE IN OUR NW HALF AS SUGGESTED BY LATEST HRRR BUT SE HALF
WILL LIKELY REMAIN DRY THROUGH 06-09Z. COLD FRONT WILL THEN SWEEP
FROM WEST TO EAST EARLY MONDAY MORNING WITH WIDESPREAD SHOWERS.
REST OF THE FORECAST REMAINS IN GOOD SHAPE. UPDATED ZFP WILL BE
OUT SHORTLY.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 405 PM EST SUN DEC 13 2015
SOLID/DEEP NATURE OF CLOUD COVER HELD LINE ON TEMPS...DESPITE
RECORD/NEAR RECORD AT THIS TIME WITH TEMPS INTO MID 60S SERN
CWA/LWR 60S ELSEWHERE. STILL POTENTIAL FOR DEGREE/TWO RISE NEXT
HOUR AND CERTAINLY POTENTIAL FOR HIGHER EXISTED FOR A TIME.
PRIMARY FOCUS ONTO UPSTREAM STRONGLY DYNAMIC MID TROPOSPHERIC
SYSTEM OVER CENTRAL OKLAHOMA AS IT BEGINS ASSERTIVE NORTHEASTWARD
LIFTOUT. PRESENT ELEVATED COLD CONVEYOR BELT/OCCLUSION ASSOCIATED
RAIN SHIELD WITH EMBEDDED/SHALLOW CONVECTIVE ELEMENTS WILL
PRIMARILY LIFT NORTHWARD WITH FAR EASTERN PERIPHERY TO LIFT
THROUGH WESTERN THIRD OF CWA THIS EVENING. LATER TONIGHT
PSUEDO/SECONDARY COLD FRONT ASSOCIATED WITH FRONTAL WAVE
/PRESENTLY DEVELOPING OVER SOUTHERN MISSOURI/ TO PRESS NEWD INTO
CWA. CORE OF RICH THETA-E/MIXING RATIOS WITH PLUS 9 G/KG IN
1000-850MB LAYER TO SUPPORT SECOND ROUND OF SHRA PRESSING FARTHER
EAST INTO CWA AS EXTREME 70-75 KT 8H JET AXIS ROTATES CCW INTO
INDIANA. BEST FORCED LIFT APPEARS IN 060-09 UTC WINDOW.
THEREAFTER...SUSPECT OVERALL DIMINISHMENT IN COVERAGE/INTENSITY
BEYOND 12 UTC...THOUGH INFLUENCE OF EXTREME/250-300M/12 HR HEIGHT
FALL CENTROID OVER NERN IL MIDDAY ALONG WITH CWA POISED WITHIN
FAVORABLE EXIT REGION OF 120-130 KT JET CORE OVER WEST CENTRAL
OHIO SHOULD AID IN CONVECTIVE MAINTENANCE MONDAY MORNING. MOISTURE
DEPTH/PWAT LOWER REMARKABLY AS DEPTH OF MOISTURE/MID LEVEL DRY
SLOTTING OVERSPREADS W-E THROUGH AFTERNOON LIMITING AMOUNTS
THEREAFTER. PROGRESSIVE NATURE OF SYSTEM ASSURED WITH PRESS OF YET
ANOTHER STRONG UPSTREAM SYSTEM INTO GREAT BASIN BY 00 UTC TUE.
THIS AND DISJOINTED NATURE OF RAFL EPISODES TO LIMIT TOTAL QPF TO
AMOUNTS EASILY HANDLED BY BASIN DRAINAGE SYSTEM. TEMPERATURES NON
DIURNAL WITH EXTREMELY WARM OVERNIGHT LOWS IN WELL MIXED
HOMOGENEOUS BOUNDARY LAYER AND FALLING THROUGH DAY/EARLY HIGHS
MON.
&&
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 405 PM EST SUN DEC 13 2015
QUICK RECOVERY IN MID/UPPER LEVEL HEIGHTS IN WAKE OF EXITING
UPPER LOW WILL ALLOW TEMPS TO REMAIN ABOVE NORMAL INTO TUESDAY AND
WEDNESDAY AS WARM ADVECTION RESUMES IN ADVANCE OF THE NEXT UPPER
LOW/SFC REFLECTION TO EJECT NORTHEAST THROUGH THE UPPER MIDWEST.
THIS PROCESS WILL BRING AN END TO ANY PCPN MONDAY NIGHT THROUGH
TUESDAY NIGHT...ALTHOUGH SUBSIDENCE/DRYING NOT ALL THAT IMPRESSIVE
WITH WARMING OVER INVERSION LIKELY LOCKING IN LOW CLOUDS LONGER
THAN CURRENTLY MODELED. LIGHT RAIN SHOWER CHANCES THEN RETURN
WEDNESDAY INTO WEDNESDAY EVENING ALONG A COLD FRONT. KEPT POPS IN
LOW-MID CHANCE RANGE...HIGHEST ACROSS NW IN/SW MI...GIVEN LACKING
MOISTURE QUALITY/RETURN.
SOLID MODEL AGREEMENT REMAINS FOR A SHOT OF COLDER/SEASONABLE AIR
THURSDAY THROUGH SATURDAY AS LONGWAVE TROUGH PROGRESSES EAST
THROUGH EASTERN NOAM. THIS COLD FLOW OVER WARMER LAKE MI WATER
SUPPORTS LOW- MID CHANCE POPS FOR LAKE EFFECT SNOW SHOWERS IN
FAVORED WEST FLOW LE ZONES. WARMER AIR WILL THEN FILTER BACK INTO
THE REGION SUNDAY INTO EARLY NEXT WEEK AS HEIGHT FIELD RELAXES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 146 AM EST MON DEC 14 2015
A LARGE DEEP LOW WAS OVER EASTERN KANSAS EARLY TODAY WITH THE
COLD AIR WRAPPING AROUND THE LOW ACROSS MISSOURI. THE COLD FRONT
WILL RACE EAST TODAY AND MOVE ACROSS NORTHERN INDIANA. THERE
SHOULD BE A FEW TO SEVERAL HOURS OF RAIN GIVEN A VERY MOIST FETCH
WITH THE LOW LEVEL CONVEYOR BELT. THE DRY SLOT WILL SPREAD OVER
THE AREA THIS AFTERNOON...BUT SOME SHOWERS ARE STILL POSSIBLE
GIVEN THE VERY COLD TEMPERATURES ALOFT. KEPT SLEET OUT OF THE TAFS
FOR NOW GIVEN EXPECTED RELATIVELY WARM BOUNDARY LEVEL TEMPS.
INCREASED WINDS FROM THE ONGOING TAFS TO COME MORE IN LINE WITH
THE LATEST NCEP/WPC HIGH RES GUIDANCE.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR LMZ043-046.
&&
$$
UPDATE...AGD
SYNOPSIS...MURPHY/SKIPPER
SHORT TERM...MURPHY
LONG TERM...STEINWEDEL
AVIATION...SKIPPER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS JACKSON KY
400 AM EST MON DEC 14 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 322 AM EST MON DEC 14 2015
THIS MORNING WE ARE TRACKING A LINE OF SHOWERS AND GUSTY WINDS
ACROSS WESTERN KY AND THIS WILL BE THE PRIMARY WEATHER MAKER FOR
THE SHORT TERM PERIOD. THIS IS ASSOCIATED WITH A COLD FRONT THAT
IS STRETCHED FROM SE IA...WESTERN KY...TO THE GULF OF MEXICO AT
06Z. THAT SAID WINDS LOOK TO BE THE MAIN CONCERN OVERALL WITH THIS
SYSTEM AND THESE SHOWERS HAVE THE ABILITY TO MIX DOWN STRONGER JET
ALOFT. VAD WIND PROFILE THIS MORNING INDICATING 40 KNOTS AT 4000
FT ABOVE THE RADAR THIS MORNING. ALL THIS SAID NOT CONFIDENT WE
WILL MIX DOWN WIND ADVISORY CRITERIA AREA WIDE...BUT MORE
CONFIDENT WE COULD 35 GUSTS PARTICULARLY ALONG THE MAIN LINE OF
SHOWERS. THEREFORE WILL ISSUE A LAKE WIND ADVISORY 12Z TO 00Z
TODAY. WHILE THE MORE WIND SPREAD GUSTS OF 35 MPH WILL OCCUR RIGHT
ALONG THE FRONT...THINK WE COULD STILL SEE GUSTY WINDS LATER IN
THE DAY. MATTER OF FACT BUFKIT SOUNDINGS AT EKQ ARE MIXING THE
DEEPEST AND THEREFORE HAVE GUSTS CERTAINLY POTENTIALLY MEETING OR
EXCEEDING LAKE WIND CRITERIA THIS AFTERNOON MAINLY ACROSS THE
BLUEGRASS AND LAKE CUMBERLAND REGIONS. OVERALL MESO MODELS TREND
THIS LINE OF SHOWERS DOWN AS IS MOVES INTO THE REGION THIS
MORNING...BUT KEPT CLOSE TO THE PREVIOUS WITH MINOR ADJUSTMENTS TO
TIMING SINCE THINKING ALL PORTIONS WILL MEASURE. AMOUNTS ARE STILL
EXPECTED TO REMAIN GENERALLY LESS THAN A HALF OF A INCH.
NOW TONIGHT THE BIGGEST CONCERN THAT REMAINS IS HOW MUCH CLOUD
COVER WE WILL SEE. SOME OF THE MODEL SOUNDINGS WOULD SUGGEST WE
BUILD DOWN SOME STRATUS LATER TONIGHT. KEPT THE BETTER COVERAGE
ACROSS THE NORTH CLOSER TO THE SURFACE LOW. THIS WILL HAVE
IMPLICATIONS ON LOWS...BUT EITHER WAY A SHIFT TO MORE WESTERLY
WIND DIRECTION SHOULD INTRODUCE MUCH COOLER AIR THAN WE HAVE SEEN
THE PAST FEW NIGHTS. THAT SAID LOWS LOOK TO DROP INTO THE MID TO
UPPER 40S. NOW LOOKS LIKE WE WILL SEE CLEARING SKIES ON TUESDAY
AS BROAD SURFACE HIGH BUILDS EAST. WHILE WE SEE COOLER AIR BEHIND
THIS SYSTEM THE MORE WINTER SEASON AIR REMAINS LOCKED UP WELL
NORTH OF THE REGION. HIGHS ON TUESDAY ARE EXPECTED TO CLIMB INTO
THE UPPER 50S TO LOWER 60S WITH AROUND 10 PLUS DEGREES HIGHER THAN
NORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 AM EST MON DEC 14 2015
MODELS ARE IN GOOD AGREEMENT FOR THE OVERALL PICTURE DURING THE
PERIOD. HIGH PRESSURE WILL MOVE AWAY TO OUR EAST TUESDAY NIGHT AND
WEDNESDAY...WITH A BRIEF WARM-UP OCCURRING. A COLD FRONT WILL MOVE
THROUGH FROM WEST TO EAST LATE WEDNESDAY NIGHT AND EARLY THURSDAY.
IT WILL BE ASSOCIATED WITH A SIGNIFICANT PROGRESSIVE LONGWAVE
TROUGH. A WAVE SHOULD DEVELOP ON THE FRONT NEAR THE GULF COAST AND
MOVE NORTHEAST ON THE EAST SIDE OF THE APPALACHIANS. RAIN FROM THIS
WAVE IS EXPECTED TO MAKE IT AS FAR NORTHWEST AS KY LATE WEDNESDAY
NIGHT INTO THURSDAY...BUT EXACTLY HOW FAR NORTHWEST AND HOW HEAVY
ARE BOTH STILL IN QUESTION. COLD AIR WILL CONTINUE TO POUR INTO THE
REGION AS THE WAVE AND FRONT DEPART. THE UPPER LEVEL TROUGH AXIS IS
FORECAST TO PASS OVER ON FRIDAY. SNOW OR RAIN SHOWERS MAY DEVELOP
UNDER THE TROUGH...AIDED BY UPSLOPE COLD AIR ADVECTION. HAVE CARRIED
A 20 PERCENT POP IN OUR EASTERN AND SOUTHEASTERN COUNTIES. DRYING
THEN ARRIVES FOR THE WEEKEND. COMPARED TO RECENT CONDITIONS...VERY
COLD AIR WILL BE IN PLACE BY THE WEEKEND...WITH TEMPERATURES
FORECAST IN THE TEENS IN VALLEYS BY SUNDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1244 AM EST MON DEC 14 2015
PERIOD BEGINS WITH VFR CONDITIONS PREVAILING ACROSS ALL THE TAF
SITES THIS OVERNIGHT HOUR. THE MAIN CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR WIND SHEAR WITH RUC MODELS SUGGESTING AROUND 45
KNOTS AT THE 1500 TO 2000 LEVEL AND LIGHT WINDS PREVAILING AT THE
SURFACE. THEN THE NEXT ISSUE WILL BE SHOWERS AND GUSTY WINDS WITH
A COLD FRONT THAT IS EXPECTED TO SWEEP ACROSS THE REGION IN THE
MORNING. THE MESO MODELS CONTINUE TO SLOW THIS SYSTEM DOWN A
BIT...SO DID OPT TO ADJUST THAT FROM PREVIOUS FORECAST. RIGHT NOW
LOOKS LIKE MVFR WOULD THE PREDOMINATE FOR CLOUDS...BUT FEW SITES
COULD SEE A QUICK SWING DOWN TO IFR NEARER THE SHOWERS. THE GUSTY
WINDS WILL PERSIST BEHIND THE FRONT AS THEY SHIFT TO A MORE
WESTERLY DIRECTION. THESE WINDS ARE FORECAST TO DECREASE AS WE
MOVE TOWARD THE EVENING HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
LAKE WIND ADVISORY FROM 7 AM THIS MORNING TO 7 PM EST THIS
EVENING FOR KYZ044-050>052-058>060-068-069-079-080-083>088-104-
106>120.
&&
$$
SHORT TERM...DJ
LONG TERM...HAL
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
322 AM EST MON DEC 14 2015
.SHORT TERM...(TODAY THROUGH TUESDAY)
ISSUED AT 322 AM EST MON DEC 14 2015
THIS MORNING WE ARE TRACKING A LINE OF SHOWERS AND GUSTY WINDS
ACROSS WESTERN KY AND THIS WILL BE THE PRIMARY WEATHER MAKER FOR
THE SHORT TERM PERIOD. THIS IS ASSOCIATED WITH A COLD FRONT THAT
IS STRETCHED FROM SE IA...WESTERN KY...TO THE GULF OF MEXICO AT
06Z. THAT SAID WINDS LOOK TO BE THE MAIN CONCERN OVERALL WITH THIS
SYSTEM AND THESE SHOWERS HAVE THE ABILITY TO MIX DOWN STRONGER JET
ALOFT. VAD WIND PROFILE THIS MORNING INDICATING 40 KNOTS AT 4000
FT ABOVE THE RADAR THIS MORNING. ALL THIS SAID NOT CONFIDENT WE
WILL MIX DOWN WIND ADVISORY CRITERIA AREA WIDE...BUT MORE
CONFIDENT WE COULD 35 GUSTS PARTICULARLY ALONG THE MAIN LINE OF
SHOWERS. THEREFORE WILL ISSUE A LAKE WIND ADVISORY 12Z TO 00Z
TODAY. WHILE THE MORE WIND SPREAD GUSTS OF 35 MPH WILL OCCUR RIGHT
ALONG THE FRONT...THINK WE COULD STILL SEE GUSTY WINDS LATER IN
THE DAY. MATTER OF FACT BUFKIT SOUNDINGS AT EKQ ARE MIXING THE
DEEPEST AND THEREFORE HAVE GUSTS CERTAINLY POTENTIALLY MEETING OR
EXCEEDING LAKE WIND CRITERIA THIS AFTERNOON MAINLY ACROSS THE
BLUEGRASS AND LAKE CUMBERLAND REGIONS. OVERALL MESO MODELS TREND
THIS LINE OF SHOWERS DOWN AS IS MOVES INTO THE REGION THIS
MORNING...BUT KEPT CLOSE TO THE PREVIOUS WITH MINOR ADJUSTMENTS TO
TIMING SINCE THINKING ALL PORTIONS WILL MEASURE. AMOUNTS ARE STILL
EXPECTED TO REMAIN GENERALLY LESS THAN A HALF OF A INCH.
NOW TONIGHT THE BIGGEST CONCERN THAT REMAINS IS HOW MUCH CLOUD
COVER WE WILL SEE. SOME OF THE MODEL SOUNDINGS WOULD SUGGEST WE
BUILD DOWN SOME STRATUS LATER TONIGHT. KEPT THE BETTER COVERAGE
ACROSS THE NORTH CLOSER TO THE SURFACE LOW. THIS WILL HAVE
IMPLICATIONS ON LOWS...BUT EITHER WAY A SHIFT TO MORE WESTERLY
WIND DIRECTION SHOULD INTRODUCE MUCH COOLER AIR THAN WE HAVE SEEN
THE PAST FEW NIGHTS. THAT SAID LOWS LOOK TO DROP INTO THE MID TO
UPPER 40S. NOW LOOKS LIKE WE WILL SEE CLEARING SKIES ON TUESDAY
AS BROAD SURFACE HIGH BUILDS EAST. WHILE WE SEE COOLER AIR BEHIND
THIS SYSTEM THE MORE WINTER SEASON AIR REMAINS LOCKED UP WELL
NORTH OF THE REGION. HIGHS ON TUESDAY ARE EXPECTED TO CLIMB INTO
THE UPPER 50S TO LOWER 60S WITH AROUND 10 PLUS DEGREES HIGHER THAN
NORMS.
.LONG TERM...(TUESDAY NIGHT THROUGH SUNDAY)
ISSUED AT 322 AM EST MON DEC 14 2015
AVAILABLE SHORTLY...
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1244 AM EST MON DEC 14 2015
PERIOD BEGINS WITH VFR CONDITIONS PREVAILING ACROSS ALL THE TAF
SITES THIS OVERNIGHT HOUR. THE MAIN CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR WIND SHEAR WITH RUC MODELS SUGGESTING AROUND 45
KNOTS AT THE 1500 TO 2000 LEVEL AND LIGHT WINDS PREVAILING AT THE
SURFACE. THEN THE NEXT ISSUE WILL BE SHOWERS AND GUSTY WINDS WITH
A COLD FRONT THAT IS EXPECTED TO SWEEP ACROSS THE REGION IN THE
MORNING. THE MESO MODELS CONTINUE TO SLOW THIS SYSTEM DOWN A
BIT...SO DID OPT TO ADJUST THAT FROM PREVIOUS FORECAST. RIGHT NOW
LOOKS LIKE MVFR WOULD THE PREDOMINATE FOR CLOUDS...BUT FEW SITES
COULD SEE A QUICK SWING DOWN TO IFR NEARER THE SHOWERS. THE GUSTY
WINDS WILL PERSIST BEHIND THE FRONT AS THEY SHIFT TO A MORE
WESTERLY DIRECTION. THESE WINDS ARE FORECAST TO DECREASE AS WE
MOVE TOWARD THE EVENING HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...DJ
LONG TERM...HAL
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1256 AM EST MON DEC 14 2015
.UPDATE...
ISSUED AT 1256 AM EST MON DEC 14 2015
SEEING QUITE THE TEMP SLITS ACROSS THE REGION THIS EVENING WITH
MANY OF THE VALLEY LOCATIONS ABLE TO DECOUPLE. RIGHT NOW JKL IS
SITTING AT 63 DEGREES...MEAN WHILE DOWN THE VALLEY AT QUICKSAND
MESONET WE ARE SEEING 47 DEGREES. WHILE WINDS HAVE BEGUN TO COME
UP THE ONLY AREAS REALLY RESPONDING THIS HOUR ARE DORT AND BLK MTN
WHICH ARE OUR HIGHER LOCATIONS AND TYPICAL WINDY SPOTS. RIGHT NOW
WILL KEEP WITH SPS HIGHLIGHTING THE WINDS AND LOOK AT THIS DEEPER
WITH PACKAGE UPDATE.
UPDATE ISSUED AT 946 PM EST SUN DEC 13 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE INCREASING WINDS ALOFT
AND EXTENSIVE CLOUD COVER AS THE FRONT APPROACHES THE AREA. THE
OVERALL FORECAST LOOKS TO BE ON TRACK AND THE ONLY TWEAK NEEDED IS
TO UPDATE HOURLY TEMPS AND DEW POINTS.
UPDATE ISSUED AT 730 PM EST SUN DEC 13 2015
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE CLOUD COVER ON
THE INCREASE AS A COLD FRONT DEVELOPS AND MOVES EAST. THIS HAS
RESULTED IN AN INCREASE IN SOUTHERLY FLOW AS THE GRADIENT
INCREASES. IN FACT...40 KNOT WINDS ARE ALREADY OVERHEAD AS THE
SYSTEM APPROACHES. HAVE INCREASED CLOUD COVER OVER THE AREA AS
MID AND UPPER LEVEL CLOUD COVER IS ON THE INCREASE. IN
ADDITION...WITH A BIT MORE INDICATION OF 30 KNOT WINDS MAKING IT
TO THE SURFACE...HAVE ISSUED AN SPS TO HIGHLIGHT THE WIND THREAT.
STILL AS IS USUALLY THE CASE...THIS FRONT WILL WEAKEN AS IT MOVES
INTO THE AREA AND THE 40 KNOT WINDS MAKING IT TO THE SURFACE OUT
WEST WILL NOT BE THE CASE HERE IN EAST KENTUCKY. HI RES
MODELS...INDICATE A WEAKENING TREND TO THE LINE OF SHOWERS SO THE
STRONGER WIND GUSTS ARE NOT EXPECTED. THE REST OF THE FORECAST
REMAINS ON TRACK BUT WILL ISSUE A NEW ZFP FOR THESE CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 223 PM EST SUN DEC 13 2015
HIGH CLOUDS HAVE REALLY KEPT TEMPERATURES FROM WARMING AS MUCH AS
THEY COULD HAVE...BUT TEMPERATURES HAVE STILL MANAGED TO REACH
RECORD LEVELS WITH MOST AREAS TOPPING OUT RIGHT AROUND 70.
FORECAST CONCERNS FOR THE SHORT TERM WILL FOCUS ON WIND AND RAIN
POTENTIAL AS A COLD FRONT PUSHES ON THROUGH FROM AROUND DAYBREAK
MONDAY INTO MIDDAY MONDAY.
A SHORTWAVE TROUGH WILL PUSH INTO THE GREAT LAKES BY MONDAY
MORNING...SENDING THE COLD FRONT ACROSS KENTUCKY. THE BETTER
FORCING AND DYNAMICS ARE EXPECTED TO SLIDE TO THE NORTH...BUT
STILL EXPECTING A BAND OF SHOWERS TO PUSH ON THROUGH EASTERN
KENTUCKY WITH THE FRONT. SHOWERS MAY BE WEAKENING AS THEY CROSS
THE AREA AND ENCOUNTER A MORE HOSTILE ENVIRONMENT WITH DOWNSLOPING
WINDS OFF THE HIGHER TERRAIN. REGARDLESS...IT APPEARS MOST AREAS
SHOULD SEE SOME RAINFALL FROM THIS FRONT...SO WILL MAINTAIN THE
CATEGORICAL POPS. HAVE CONTINUED TO SLOW DOWN THE BEST POPS AS
MOST OF THE RAIN SHOULD COME IN OUR AREA AFTER 12Z. ANOTHER
DIFFICULT TEMPERATURE FORECAST TONIGHT...AS SOME OF THE DEEPER
EASTERN VALLEYS COULD BRIEFLY DECOUPLE AND SEND THEIR TEMPERATURES
DOWN WELL INTO THE 50S...WHILE RIDGES AND AREAS THAT STAY MIXED
COULD STAY IN THE 60S. REGARDLESS...EXPECT QUITE A SPREAD IN
TEMPERATURES OVERNIGHT...BUT STILL VERY MILD FOR THIS TIME OF
YEAR. CLOUD COVER AND RAIN SHOULD KEEP TEMPERATURES FROM RISING
MUCH ON MONDAY...BUT WE COULD SEE A BRIEF UPTICK IN TEMPERATURES
LATE IN THE DAY AS CLOUDS TRY TO BREAK UP. THERE IS A SECONDARY
WAVE THAT WILL CROSS THE OHIO RIVER VALLEY THROUGH THE EVENING
HOURS AND COULD SPIT OUT A FEW SPRINKLES...BUT SHOULD NOT BE A BIG
DEAL.
MAIN CONCERN ON MONDAY WILL BE AROUND THE WIND POTENTIAL. 12 MODELS
HAVE TRENDED UP SLIGHTLY WITH THE WIND POTENTIAL FROM THE 00Z
RUN...BUT ONLY SLIGHTLY. 12Z NAM/GFS BUFKIT SOUNDINGS SUPPORT WIND
GUSTS REACHING 30 TO 35 MPH...WHICH IS BORDERLINE LAKE WIND
ADVISORY CRITERIA FOR EASTERN KENTUCKY. THE STRONGEST WINDS SHOULD
ARRIVE POST FRONTAL...BUT CONFIDENCE STILL REMAINS LOW ON EXACTLY
HOW MUCH WIND CAN MIX DOWN BEHIND THE FRONT. GIVEN ITS STILL THE
SECOND PERIOD...OPTING TO HOLD OFF ON ANY HEADLINES AND LET
EVENING OR MIDNIGHT SHIFT REEVALUATE THE NEED FOR ANY HEADLINES.
WILL CARRY SOME GUSTY WIND POTENTIAL IN THE HWO FOR MONDAY.
STILL LOTS OF UNCERTAINTY REGARDING CLOUD COVER FOR MONDAY
NIGHT. 12Z NAM IS FAIRLY AGGRESSIVE IN KEEPING CLOUDS AROUND
OVERNIGHT...WHILE GFS AND ECMWF HAVE MUCH LESS CLOUD COVER. OPTING
TO CONTINUE TO GO PARTLY TO MOSTLY CLOUDY FOR NOW...BUT ITS VERY
POSSIBLE IT EITHER ENDS UP OVERCAST OR MOSTLY CLEAR. LOWS MONDAY
NIGHT WILL BE MUCH COOLER WITH READINGS SETTLING BACK INTO THE
40S...BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN DEC 13 2015
THE EXTENDED PERIOD WILL START OUT DRY WITH AN UPPER LEVEL RIDGE
SITUATED OVER KENTUCKY TUESDAY AND WEDNESDAY. BY WEDNESDAY
EVENING...A DEEP UPPER LEVEL TROUGH WILL REACH THE WESTERN GREAT
LAKES. THIS SYSTEM WILL DRIVE A COLD FRONT THROUGH THE OHIO VALLEY
EARLY THURSDAY BUT WILL HAVE A TOUGH TIME TAPPING INTO MOISTURE.
THERE ARE STILL SOME DIFFERENCES BETWEEN THE GFS AND ECMWF WITH
TIMING AND AMOUNT OF PRECIP WHICH STEM FROM THE UPPER LEVEL TROUGH
AMPLIFICATION DIFFERENCES. HOWEVER...IT IS LIKELY THAT WE WILL
SEE SOME SHOWERS THURSDAY MORNING BUT MAY NOT AMOUNT TO MUCH OR BE
WIDESPREAD. THAT BEING SAID...WILL STICK CLOSE TO THE CR
SUPERBLEND AND KEEP CHANCE POPS IN THE FORECAST.
BROAD UPPER LEVEL TROUGHINESS WILL LINGER OVER THE EASTERN CONUS
THROUGH SUNDAY MORNING KEEPING THINGS MAINLY DRY WITH SOME CLOUDS.
THE ONLY EXCEPTION IS FOR SOME LIGHT QPF IN THE FORM OF RAIN/SNOW
SHOWERS ALONG THE KY/VA BORDER EARLY SATURDAY. THIS IS DUE TO A
STRONG UPPER LEVEL DISTURBANCE SWINGING THROUGH THE TROUGH. UNLIKE
THE MODEL RUNS YESTERDAY...BOTH THE GFS AND 00Z ECMWF NOW SUPPORT
THIS QPF SO HAVE DECIDED TO INCLUDE BRIEF SLIGHT CHANCE POPS.
HIGH PRESSURE BUILDS BACK INTO THE REGION ON SUNDAY.
ABOVE NORMAL TEMPERATURES ARE EXPECTED AT THE START OF THE PERIOD
BUT WILL DROP INTO THE 40S BY FRIDAY. THE WEEKEND LOOKS EVEN COLDER
AS HIGHS MAY STRUGGLE TO GET OUT OF THE 30S ON SATURDAY AND THEN
WILL BEGIN TO REBOUND LEADING INTO THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1244 AM EST MON DEC 14 2015
PERIOD BEGINS WITH VFR CONDITIONS PREVAILING ACROSS ALL THE TAF
SITES THIS OVERNIGHT HOUR. THE MAIN CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR WIND SHEAR WITH RUC MODELS SUGGESTING AROUND 45
KNOTS AT THE 1500 TO 2000 LEVEL AND LIGHT WINDS PREVAILING AT THE
SURFACE. THEN THE NEXT ISSUE WILL BE SHOWERS AND GUSTY WINDS WITH
A COLD FRONT THAT IS EXPECTED TO SWEEP ACROSS THE REGION IN THE
MORNING. THE MESO MODELS CONTINUE TO SLOW THIS SYSTEM DOWN A
BIT...SO DID OPT TO ADJUST THAT FROM PREVIOUS FORECAST. RIGHT NOW
LOOKS LIKE MVFR WOULD THE PREDOMINATE FOR CLOUDS...BUT FEW SITES
COULD SEE A QUICK SWING DOWN TO IFR NEARER THE SHOWERS. THE GUSTY
WINDS WILL PERSIST BEHIND THE FRONT AS THEY SHIFT TO A MORE
WESTERLY DIRECTION. THESE WINDS ARE FORECAST TO DECREASE AS WE
MOVE TOWARD THE EVENING HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...DJ
SHORT TERM...KAS
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS JACKSON KY
1244 AM EST MON DEC 14 2015
.UPDATE...
ISSUED AT 946 PM EST SUN DEC 13 2015
CURRENT CONDITIONS ACROSS THE AREA FEATURE INCREASING WINDS ALOFT
AND EXTENSIVE CLOUD COVER AS THE FRONT APPROACHES THE AREA. THE
OVERALL FORECAST LOOKS TO BE ON TRACK AND THE ONLY TWEAK NEEDED IS
TO UPDATE HOURLY TEMPS AND DEW POINTS.
UPDATE ISSUED AT 730 PM EST SUN DEC 13 2015
CURRENT CONDITIONS ACROSS EASTERN KENTUCKY FEATURE CLOUD COVER ON
THE INCREASE AS A COLD FRONT DEVELOPS AND MOVES EAST. THIS HAS
RESULTED IN AN INCREASE IN SOUTHERLY FLOW AS THE GRADIENT
INCREASES. IN FACT...40 KNOT WINDS ARE ALREADY OVERHEAD AS THE
SYSTEM APPROACHES. HAVE INCREASED CLOUD COVER OVER THE AREA AS
MID AND UPPER LEVEL CLOUD COVER IS ON THE INCREASE. IN
ADDITION...WITH A BIT MORE INDICATION OF 30 KNOT WINDS MAKING IT
TO THE SURFACE...HAVE ISSUED AN SPS TO HIGHLIGHT THE WIND THREAT.
STILL AS IS USUALLY THE CASE...THIS FRONT WILL WEAKEN AS IT MOVES
INTO THE AREA AND THE 40 KNOT WINDS MAKING IT TO THE SURFACE OUT
WEST WILL NOT BE THE CASE HERE IN EAST KENTUCKY. HI RES
MODELS...INDICATE A WEAKENING TREND TO THE LINE OF SHOWERS SO THE
STRONGER WIND GUSTS ARE NOT EXPECTED. THE REST OF THE FORECAST
REMAINS ON TRACK BUT WILL ISSUE A NEW ZFP FOR THESE CHANGES.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 223 PM EST SUN DEC 13 2015
HIGH CLOUDS HAVE REALLY KEPT TEMPERATURES FROM WARMING AS MUCH AS
THEY COULD HAVE...BUT TEMPERATURES HAVE STILL MANAGED TO REACH
RECORD LEVELS WITH MOST AREAS TOPPING OUT RIGHT AROUND 70.
FORECAST CONCERNS FOR THE SHORT TERM WILL FOCUS ON WIND AND RAIN
POTENTIAL AS A COLD FRONT PUSHES ON THROUGH FROM AROUND DAYBREAK
MONDAY INTO MIDDAY MONDAY.
A SHORTWAVE TROUGH WILL PUSH INTO THE GREAT LAKES BY MONDAY
MORNING...SENDING THE COLD FRONT ACROSS KENTUCKY. THE BETTER
FORCING AND DYNAMICS ARE EXPECTED TO SLIDE TO THE NORTH...BUT
STILL EXPECTING A BAND OF SHOWERS TO PUSH ON THROUGH EASTERN
KENTUCKY WITH THE FRONT. SHOWERS MAY BE WEAKENING AS THEY CROSS
THE AREA AND ENCOUNTER A MORE HOSTILE ENVIRONMENT WITH DOWNSLOPING
WINDS OFF THE HIGHER TERRAIN. REGARDLESS...IT APPEARS MOST AREAS
SHOULD SEE SOME RAINFALL FROM THIS FRONT...SO WILL MAINTAIN THE
CATEGORICAL POPS. HAVE CONTINUED TO SLOW DOWN THE BEST POPS AS
MOST OF THE RAIN SHOULD COME IN OUR AREA AFTER 12Z. ANOTHER
DIFFICULT TEMPERATURE FORECAST TONIGHT...AS SOME OF THE DEEPER
EASTERN VALLEYS COULD BRIEFLY DECOUPLE AND SEND THEIR TEMPERATURES
DOWN WELL INTO THE 50S...WHILE RIDGES AND AREAS THAT STAY MIXED
COULD STAY IN THE 60S. REGARDLESS...EXPECT QUITE A SPREAD IN
TEMPERATURES OVERNIGHT...BUT STILL VERY MILD FOR THIS TIME OF
YEAR. CLOUD COVER AND RAIN SHOULD KEEP TEMPERATURES FROM RISING
MUCH ON MONDAY...BUT WE COULD SEE A BRIEF UPTICK IN TEMPERATURES
LATE IN THE DAY AS CLOUDS TRY TO BREAK UP. THERE IS A SECONDARY
WAVE THAT WILL CROSS THE OHIO RIVER VALLEY THROUGH THE EVENING
HOURS AND COULD SPIT OUT A FEW SPRINKLES...BUT SHOULD NOT BE A BIG
DEAL.
MAIN CONCERN ON MONDAY WILL BE AROUND THE WIND POTENTIAL. 12 MODELS
HAVE TRENDED UP SLIGHTLY WITH THE WIND POTENTIAL FROM THE 00Z
RUN...BUT ONLY SLIGHTLY. 12Z NAM/GFS BUFKIT SOUNDINGS SUPPORT WIND
GUSTS REACHING 30 TO 35 MPH...WHICH IS BORDERLINE LAKE WIND
ADVISORY CRITERIA FOR EASTERN KENTUCKY. THE STRONGEST WINDS SHOULD
ARRIVE POST FRONTAL...BUT CONFIDENCE STILL REMAINS LOW ON EXACTLY
HOW MUCH WIND CAN MIX DOWN BEHIND THE FRONT. GIVEN ITS STILL THE
SECOND PERIOD...OPTING TO HOLD OFF ON ANY HEADLINES AND LET
EVENING OR MIDNIGHT SHIFT REEVALUATE THE NEED FOR ANY HEADLINES.
WILL CARRY SOME GUSTY WIND POTENTIAL IN THE HWO FOR MONDAY.
STILL LOTS OF UNCERTAINTY REGARDING CLOUD COVER FOR MONDAY
NIGHT. 12Z NAM IS FAIRLY AGGRESSIVE IN KEEPING CLOUDS AROUND
OVERNIGHT...WHILE GFS AND ECMWF HAVE MUCH LESS CLOUD COVER. OPTING
TO CONTINUE TO GO PARTLY TO MOSTLY CLOUDY FOR NOW...BUT ITS VERY
POSSIBLE IT EITHER ENDS UP OVERCAST OR MOSTLY CLEAR. LOWS MONDAY
NIGHT WILL BE MUCH COOLER WITH READINGS SETTLING BACK INTO THE
40S...BUT STILL ABOVE NORMAL FOR THIS TIME OF YEAR.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 310 PM EST SUN DEC 13 2015
THE EXTENDED PERIOD WILL START OUT DRY WITH AN UPPER LEVEL RIDGE
SITUATED OVER KENTUCKY TUESDAY AND WEDNESDAY. BY WEDNESDAY
EVENING...A DEEP UPPER LEVEL TROUGH WILL REACH THE WESTERN GREAT
LAKES. THIS SYSTEM WILL DRIVE A COLD FRONT THROUGH THE OHIO VALLEY
EARLY THURSDAY BUT WILL HAVE A TOUGH TIME TAPPING INTO MOISTURE.
THERE ARE STILL SOME DIFFERENCES BETWEEN THE GFS AND ECMWF WITH
TIMING AND AMOUNT OF PRECIP WHICH STEM FROM THE UPPER LEVEL TROUGH
AMPLIFICATION DIFFERENCES. HOWEVER...IT IS LIKELY THAT WE WILL
SEE SOME SHOWERS THURSDAY MORNING BUT MAY NOT AMOUNT TO MUCH OR BE
WIDESPREAD. THAT BEING SAID...WILL STICK CLOSE TO THE CR
SUPERBLEND AND KEEP CHANCE POPS IN THE FORECAST.
BROAD UPPER LEVEL TROUGHINESS WILL LINGER OVER THE EASTERN CONUS
THROUGH SUNDAY MORNING KEEPING THINGS MAINLY DRY WITH SOME CLOUDS.
THE ONLY EXCEPTION IS FOR SOME LIGHT QPF IN THE FORM OF RAIN/SNOW
SHOWERS ALONG THE KY/VA BORDER EARLY SATURDAY. THIS IS DUE TO A
STRONG UPPER LEVEL DISTURBANCE SWINGING THROUGH THE TROUGH. UNLIKE
THE MODEL RUNS YESTERDAY...BOTH THE GFS AND 00Z ECMWF NOW SUPPORT
THIS QPF SO HAVE DECIDED TO INCLUDE BRIEF SLIGHT CHANCE POPS.
HIGH PRESSURE BUILDS BACK INTO THE REGION ON SUNDAY.
ABOVE NORMAL TEMPERATURES ARE EXPECTED AT THE START OF THE PERIOD
BUT WILL DROP INTO THE 40S BY FRIDAY. THE WEEKEND LOOKS EVEN COLDER
AS HIGHS MAY STRUGGLE TO GET OUT OF THE 30S ON SATURDAY AND THEN
WILL BEGIN TO REBOUND LEADING INTO THE WORK WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1244 AM EST MON DEC 14 2015
PERIOD BEGINS WITH VFR CONDITIONS PREVAILING ACROSS ALL THE TAF
SITES THIS OVERNIGHT HOUR. THE MAIN CONCERN OVERNIGHT WILL BE THE
POTENTIAL FOR WIND SHEAR WITH RUC MODELS SUGGESTING AROUND 45
KNOTS AT THE 1500 TO 2000 LEVEL AND LIGHT WINDS PREVAILING AT THE
SURFACE. THEN THE NEXT ISSUE WILL BE SHOWERS AND GUSTY WINDS WITH
A COLD FRONT THAT IS EXPECTED TO SWEEP ACROSS THE REGION IN THE
MORNING. THE MESO MODELS CONTINUE TO SLOW THIS SYSTEM DOWN A
BIT...SO DID OPT TO ADJUST THAT FROM PREVIOUS FORECAST. RIGHT NOW
LOOKS LIKE MVFR WOULD THE PREDOMINATE FOR CLOUDS...BUT FEW SITES
COULD SEE A QUICK SWING DOWN TO IFR NEARER THE SHOWERS. THE GUSTY
WINDS WILL PERSIST BEHIND THE FRONT AS THEY SHIFT TO A MORE
WESTERLY DIRECTION. THESE WINDS ARE FORECAST TO DECREASE AS WE
MOVE TOWARD THE EVENING HOURS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...SHALLENBERGER
SHORT TERM...KAS
LONG TERM...JVM
AVIATION...DJ
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
339 AM CST MON DEC 14 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 335 AM CST Mon Dec 14 2015
Although the period of steady rain has ended now that the axis
of strongest moisture convergence has progressed eastward, scattered
to numerous showers were still occurring early this morning farther
back over MO/KS/AR/OK. These showers are associated with the upper
low center, which was located near the MO/KS border at 09z per
satellite imagery and RAP analyses. These showers will accompany the
upper low today as it tracks northeastward from MO into IL/WI,
leading to periods of rain across MO/IL. Simultaneously, a vort lobe
rotating around the back side of the departing upper low may bring
an increased chance of showers to parts of northeast MO/west central
IL this aftn. The PoP grids attempt to reflect this complexity.
Stronger winds aloft will be transported down to the surface today,
leading to windy conditions at times. Both sustained winds and gusts
appear to remain below advisory criteria attm.
Non-diurnal temperatures are expected again today due to the
competing influences of CAA behind a cold front, diurnal warming,
and lingering precip/cloud cover.
Kanofsky
.LONG TERM: (Tonight through Sunday)
Issued at 335 AM CST Mon Dec 14 2015
(Tonight)
Dry weather is in the offing for the area as relatively narrow NW-SE
oriented surface ridge in the wake of today`s system passes through
the region. Primary question is cloud trends, and although the
tendency should be a clearing of the post system low cloudiness from
SW to NE guidance varies a great deal on how quickly this will
occur. MOS output based on the NAM...with its typically moist low
levels...holds onto a good deal of low cloudiness into Tuesday
morning, while GFS MOS certainly suggests a decrease in the cloud
cover. Given that the low level wind forecasts have a pronounced
westerly component that should aid in clearing of the low
cloudiness, will lean towards trends suggested by GFS MOS. Some
fog is certainly possible as well given the water-logged ground
across the region and decreasing winds as the surface ridge works
into the area, but will let day shift take another look at
this before including in forecast.
(Tuesday-Wednesday)
Heading into the middle of the week attention turns to potent and
fast moving upper level system that migrates from the central Plains
into the upper Mississippi Valley Tuesday afternoon-Wednesday
afternoon. With forcing well to the north and with limited moisture
return, it still appears rain threat with this system will be rather
low. Overall forecast trends remain the same, although did attempt
to fine-tune the timing of the rain threat just a bit due to the
good agreement in the 00z solutions WRT movement of upper level
features as well as surface cold front.
(Thursday-Sunday)
No major changes in forecast specifics during this time frame, with
all NWP solutions still indicating deep upper trof developing over
the central CONUS Thursday-Friday. The drop in heights over the
region should finally allow a much more typical early winter AMS to
settle into the mid Mississippi Valley, with 850mb temps of at
leaast -10C progged into the area by Friday morning. This cool down
should bring the CWA its first real taste of winter temperatures
with highs in the 30s to low 40s by Friday...first time temps have
been near or below their daily averages since early this month.
However, it appears that these winter temperatures will be short-
lived, as progressive UA pattern allows strong ridging to build back
across the central CONUS during the upcoming weekend as deep trof
works its way into the eastern U.S. AMS over the region should
modify quicky during this transition, and the main question is how
fast this modification will occur. If tonight`s medium range
solutions are correct warmup could begin already on Saturday, but
given the fact that models are often too fast in a high amplitude
regime will keep Saturday`s temps on the cool side, and begin the
warmup in earnest on Sunday, with highs returning to the 40s and 50s.
It still appears that dry conditions will dominate the CWA during
the Thursday-Sunday temperature roller coaster.
Truett
&&
.AVIATION: (For the 00z TAFs through 00z Monday Evening)
Issued at 554 PM CST Sun Dec 13 2015
Expect RA to continue thru the night. After the RA shield passes
NE of the terminal, expect an area of SHRA to move thru the region
late tonight and into Mon morning. Expect mainly low MVFR
conditions within the main RA shield, but some pockets of IFR are
possible. With sunset, these pockets may expand, but will need to
monitor trends. Also expect winds to pick up late tonight and thru
Mon morning. Going wind forecast may not be high enuf, but will
wait for more guidance tonight. Expect MVFR cigs to persist thru
Mon, perhaps becoming VFR Mon evening.
Tilly
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 54 41 56 48 / 70 5 5 40
Quincy 50 37 50 43 / 60 5 5 20
Columbia 48 38 57 42 / 50 5 5 20
Jefferson City 50 38 59 43 / 50 5 5 20
Salem 54 42 55 47 / 40 5 5 20
Farmington 52 39 57 48 / 30 5 5 40
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1045 PM MST SUN DEC 13 2015
.AVIATION...
06Z TAF CYCLE
BAND OF MID TO HIGH CLOUDS WILL CROSS NM FROM WEST TO EAST IN
ADVANCE OF INCOMING STORM SYSTEM CURRENTLY DIGGING INTO THE GREAT
BASIN. LOCALLY GUSTY WESTERLY WINDS POSSIBLE THRU 15Z ALONG THE
CENTRAL MT CHAIN DUE TO SFC LEE TROF. STILL NOT ANTICIPATING
WIDESPREAD LOW CLOUDS OR FOG BEFORE 13Z ALTHOUGH SOME LOCALIZED
MVFR TO IFR CIGS/VSBYS IN BR COULD DEVELOP ALONG THE CENTRAL MT
CHAIN AND NW NM. DETERIORATING CONDITIONS EXPECTED AFT 17Z WEST OF
THE CONTDVD AS THE STORM SYSTEM BEGINS TO AFFECT NM.
&&
.PREV DISCUSSION...636 PM MST SUN DEC 13 2015...
.UPDATE...
SNOW AND THE STRONGER WINDS HAVE ABATED IN UNION COUNTY THIS
EVENING...SO THE WINTER STORM WARNING WILL BE CANCELLED FOR THIS
LAST REMAINING ZONE. THE WATCH WILL CONTINUE FOR THE NORTHERN
MOUNTAINS FOR LATE MONDAY INTO TUESDAY WHEN THE NEXT STORM SYSTEM
WILL QUICKLY ARRIVE.
FOR TONIGHT...THERE IS STILL SOME CONCERN THAT PATCHES OF
FREEZING FOG COULD DEVELOP. THE HRRR AND RAP MODELS INDICATE THE
MIDDLE RIO GRANDE VALLEY AND SOME OF THE SHELTERED AND RELATIVELY
LOWER ELEVATIONS IN THE NORTH CENTRAL TO NORTHWEST PARTS OF NM
MIGHT BE FAVORED FOR NEAR-SURFACE SATURATION. DEWPOINTS DID NOT
SURGE UP AS HIGH AS MIGHT BE EXPECTED IN THIS REGION CONSIDERING
THIS AFTERNOON`S INSOLATION AND MELTING SNOW...SO CONFIDENCE IN
FOG DEVELOPMENT IS NOT ALL THAT HIGH. THUS...ONLY A MINIMAL
EXPANSION OF FOG WAS DRAWN IN FOR THESE AREAS. THESE ALTERATIONS
WILL NOT BE REFLECTED IN THE ZONE FORECAST PACKAGE...BUT ONLY IN
THE POINT AND CLICK WEB BASED FORECAST. THUS NO NEW UPDATED ZONE
FORECAST PACKAGE WILL BE SENT AT THIS TIME.
52
&&
.PREV DISCUSSION...311 PM MST SUN DEC 13 2015...
.SYNOPSIS...
ANOTHER STORM WILL MOVE OVER NEW MEXICO MONDAY THROUGH TUESDAY. VERY
COLD AIR AND BREEZY CONDITIONS WILL FORCE WIND CHILL VALUES INTO THE
SINGLE DIGITS AND TEENS THROUGH WEDNESDAY. OVERNIGHT LOWS WILL BE
THE COLDEST OF THE SEASON WITH READINGS NEAR ZERO IN NORTHERN AND
WESTERN VALLEYS BY TUESDAY AND WEDNESDAY NIGHT. A HEAVY DOSE OF
DRY FLUFFY SNOWFALL IS POSSIBLE ON WEST FACING SLOPES OF THE
SANGRE DE CRISTO MOUNTAINS AND THE SAN JUANS MONDAY NIGHT AND
TUESDAY. HIGH TEMPERATURES WILL REMAIN VERY COLD THROUGH THURSDAY
BEFORE A SLOW WARMING TREND BEGINS LATE IN THE WEEK.
&&
.DISCUSSION...
BLIZZARD CONDITIONS ARE SLOWLY WINDING DOWN OVER UNION COUNTY WHERE
SEVERAL ROAD CLOSURES HAVE OCCURRED. VSBYS NEAR ONE QUARTER MILE FOR
MOST OF THE DAY WITH STRONG WINDS HAS LED TO EXTREMELY DANGEROUS
TRAVEL. THE ONE SAVING GRACE IS TEMPS ARE HOVERING NEAR FREEZING...
MAKING THE SNOWFALL AT LEAST A LITTLE STICKIER. NONETHELESS...WILL
STILL HIGHLIGHT BLOWING SNOW THROUGH TONIGHT AND POSSIBLY EXTEND
WARNING THROUGH THE EVENING...OR REPLACE WITH BLOWING SNOW ADVISORY.
THE BIG STORY OVER THE COMING DAYS WILL BE VERY COLD AIR SETTLING
INTO THE STATE BEHIND THE NEXT SYSTEM ARRIVING FROM THE NORTHWEST...
AS WELL AS A POTENTIALLY IMPRESSIVE WEST SLOPE SNOW EVENT FOR THE
SANGRE DE CRISTOS AND SAN JUANS. THE PACIFIC FRONT WILL ARRIVE FROM
WEST TO EAST MONDAY AND ALLOW ANY RAIN TO CHANGE TO SNOW WHILE TEMPS
TUMBLE. WINDS WILL ALSO BE GUSTY ALONG AND BEHIND THE FRONT. STRONG
COLD ADVECTION ON MOIST UNSTABLE WESTERLY FLOW WILL FORCE AN IDEAL
DENDRITIC GROWTH ZONE SMACK DAB OVER THE HIGH TERRAIN MONDAY NIGHT
TO TUESDAY. THE SPC HI RES WRF...THE LOCAL 5KM WRF...AND NAM218 ARE
SQUEEZING OUT GENEROUS QPF FOR SUCH A COLD LAYER...LEADING TO VERY
HIGH SNOW RATIOS AROUND 20:1. WILL HOIST A WATCH FOR THESE AREAS.
MAY ALSO SEE A FEW ADVISORIES IN ADJACENT LOWER TERRAIN AREAS.
OVERNIGHT LOWS BEHIND THIS SYSTEM WILL BE THE COLDEST OF THE SEASON
WITH LOTS OF NEAR ZERO TO LOW TEENS FOR CENTRAL AND WESTERN NM.
WINDS WILL ALSO MAKE IT FEEL BRUTAL. ONE MORE FAST MOVING WAVE IN NW
FLOW IS SHOWN TO MOVE OVER THE STATE THURSDAY BEFORE A SLOW WARMING
TREND DEVELOPS OVER THE WEEKEND.
GUYER
&&
.FIRE WEATHER...
AS THE FIRST IN A ONE TWO PUNCH OF UPPER LEVEL LOW PRESSURE SYSTEMS
EXITS THE AREA TO THE NE...STRONG WINDS WILL GRADUALLY WEAKEN ACROSS
NE NM THIS EVENING. HOWEVER...BREEZY TO WINDY CONDITIONS ARE
EXPECTED THROUGH TONIGHT ACROSS THE HIGH TERRAIN OF NORTHERN AND
CENTRAL NM...AS WELL AS THE REGION FROM CLINES CORNERS TO VAUGHN.
THERE WILL A BRIEF WEAKENING OF WINDS ALOFT THIS EVENING...BUT
SPEEDS WILL STRENGTHEN AGAIN TONIGHT THROUGH MONDAY AS ANOTHER JET
STREAK MOVES OVER THE AREA AROUND THE BASE OF OUR NEXT UPPER LEVEL
TROUGH. WITH ALL THE SNOW ON THE GROUND VERTICAL MIXING WILL BE
LIMITED MONDAY...RELEGATING STRONGER SOUTHWEST WINDS TO THE HIGH
TERRAIN. IT WILL BE LESS WINDY BUT STILL GUSTY AT LOWER
ELEVATIONS...ESPECIALLY FROM CLINES CORNERS TO GRAN QUIVIRA AND
BOSQUE DEL APACHE.
THE NEXT UPPER LEVEL LOW PRESSURE SYSTEM IS FORECAST TO TRACK
EASTWARD ACROSS S CO MONDAY NIGHT AND TUESDAY. MODELS DEPICT A
DECENT TAP OF MOISTURE OFF THE PACIFIC WITH THIS STORM. AND...IT
WILL BE A COLD SYSTEM WHICH WILL SPREAD SNOW ACROSS MUCH OF
WESTERN...NORTHERN AND CENTRAL NM MONDAY AND MONDAY NIGHT.
THEN...DRIER VARIETY SNOW WILL PERSIST THROUGH AT LEAST TUESDAY IN
THE NORTHERN MOUNTAINS WITH SIGNIFICANT ACCUMULATION POSSIBLE THERE.
A PACIFIC COLD FRONT WILL CROSS FROM THE WEST MONDAY NIGHT SHIFTING
WINDS OUT OF THE W BY TUESDAY. A DECENT SURFACE PRESSURE GRADIENT
AROUND THE BASE OF A SURFACE LOW EXITING COLORADO...AND THE TAIL END
OF THE AFOREMENTIONED JET STREAK...SHOULD SET UP EASTERN AREAS FOR A
WINDY DAY ON TUESDAY WITH GUSTS IN THE 40 TO PERHAPS 50 MPH RANGE
AROUND AND S OF I-40.
NW FLOW ALOFT WILL TRACK AN ADDITIONAL UPPER LEVEL TROUGH ACROSS NE
NM THURSDAY...WITH LIGHT ADDITIONAL PRECIP POSSIBLE ACROSS THE
NORTHERN MOUNTAINS AND NE.
TEMPERATURE-WISE...AFTER A BRIEF REBOUND OF HIGHS ON
MONDAY...READINGS WILL PLUMMET AROUND 10 TO 19 DEGREES BELOW NORMAL
TUESDAY THROUGH THURSDAY. WIDESPREAD POOR VENTILATION IS EXPECTED
FROM THE RIO GRANDE VALLEY EASTWARD MONDAY...BUT WESTERN AREAS
SHOULD HAVE STRONG VENTILATION AS WINDS ALOFT STRENGTHEN FROM THE
WEST. THE PASSING UPPER LOW AND UPPER TROUGH WILL LEAD TO
VENTILATION IMPROVEMENT AREAWIDE TUESDAY AND THURSDAY...BUT
WIDESPREAD POOR VENTILATION IS EXPECTED IN THE WAKE OF COLD FRONTS
WEDNESDAY AND FRIDAY.
TEMPERATURES SHOULD REBOUND NICELY AS A RIDGE OF HIGH PRESSURE
CROSSES AT THE END OF THE WEEK...BUT TEMPERATURE INVERSIONS SHOULD
KEEP VENTILATION POOR FOR MANY AREAS INTO NEXT WEEKEND.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM MONDAY AFTERNOON THROUGH TUESDAY AFTERNOON
FOR THE FOLLOWING ZONES... NMZ510-512>514.
&&
$$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
324 AM EST MON DEC 14 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A WEAK COLD FRONT WILL
APPROACH FROM THE WEST MONDAY AND MOVE THROUGH THE REGION MONDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST BEHIND THE FRONT
TUESDAY AND SLIDE OFFSHORE WEDNESDAY. A STRONG COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY AND CROSSES THE AREA FRIDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST THIS WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 315 AM MONDAY...LOW-LEVEL MOISTURE WILL CONTINUE TO STEADILY
INCREASE THROUGH THE DAY AHEAD OF COLD FRONT AS PRECIPITABLE WATER
VALUES FROM THE HRRR MODEL SURGES TO NEAR 2 INCHES BY LATE
AFTERNOON. RADAR REFLECTIVITY PROGS FROM HRRR/RAP AND 4KM NAM DO
NOT SHOW MUCH IN THE WAY OF PRECIPITATION BEFORE ABOUT 18Z WITH
SHOWERS MOVING IN AFTER THAT AND CONTINUING INTO THE EVENING. PER
FORECAST SOUNDINGS...INSTABILITY IS LIMITED BUT WITH WARM HIGH
TEMPERATURES WELL INTO THE 70S...CONTINUED THE MENTION OF A SMALL
THREAT OF THUNDER TODAY. WOULD EXPECT THE HEAVIEST OF ANY RAIN
THAT FALLS TODAY TO BE NEAR THE COAST.
&&
.SHORT TERM /TONIGHT/...
AS OF 320 AM MONDAY...RAIN WILL LINGER NEAR THE COAST THROUGH
ABOUT MIDNIGHT BEFORE RAPID CLEARING OCCURS BETWEEN 06Z AND 12Z
WITH DOWNSLOPING FLOW AND LOWERING DEWPOINTS. LOWS TONIGHT WILL BE
IN THE 50S AREA-WIDE...EXCEPT LOWER 60S ALONG THE OUTER BANKS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 3 AM MON...UNSEASONABLY WARM WEATHER TO CONTINUE THROUGH
THURSDAY THEN MUCH COLDER THIS WEEKEND.
TUESDAY THROUGH WEDNESDAY...WEAK HIGH PRESSURE BUILDS ACROSS FROM
THE WEST AS UPR RDG RE-BUILDS OVER REGION. MILD AND DRY WEATHER
WITH HIGHS IN THE UPR 60S TO LOW 70S TUE AND LOWS MID 40S INLAND
TO LOWER 50S CST. A FEW DEGREES COOLER FOR WED WITH LOW LEVEL NE/E
FLOW...HIGHS 60-70 DEG.
WEDNESDAY NIGHT THROUGH FRIDAY...MOISTURE SURGES NE INTO REGION
WED NIGHT...AS WARM FRONT LIFTS THROUGH THE AREA...AHEAD OF DEEP
BROAD UPPER TROF AND COLD FRONT TO THE W. COULD SEE NON-DIURNAL
TEMP CURVE AS SLY FLOW DEVELOPS. CHC POPS PROGGED TO DEVELOP
LATER WED NIGHT DEEP INLAND AND ALONG THE SOUTHERN COAST. PRECIP
CONTINUES OVER REGION THU INTO THU NIGHT WITH MOST MDLS SHOWING
PLENTY OF MOISTURE AND QPF. WILL CONTINUE LIKELY POPS THU AND THU
NIGHT. PERIODS OF HEAVY RAIN WILL BE POSSIBLE...WITH FORECAST
SOUNDINGS SHOWING PWAT VALUES INCREASING TO AROUND 1.75". DID ADD
ISO TSTM MENTION THU...WITH GFS SHOWING SOME MODEST INSTABILITY
DEVELOPING. MODEL DIFFERENCES CONTINUE WITH JUST HOW QUICKLY THE
FRONT PUSHES THROUGH THE AREA AND DEEPER MOISTURE MOVES OFFSHORE
LATE THU NIGHT AND FRI WITH SW FLOW CONTINUING ALOFT AND THE UPPER
TROF AXIS REMAINING W OF THE REGION. ULTIMATELY IT WILL DEPEND ON
THE TIMING OF AN EMBEDDED SHORTWAVE MOVING THROUGH THE SW FLOW
ALOFT. 00Z MODELS CONTINUE TO TREND SLOWER PUSHING THE FRONT
THROUGH AND DEEPER MOISTURE OFFSHORE AND WILL CONTINUE CHC POPS
FRI MORNING WITH GRADUAL CLEARING FROM THE WEST THROUGH THE
AFTERNOON/EVENING. IT WILL REMAIN MILD AHEAD OF FRONT WITH HIGHS
THU IN THE UPPER 60S TO LOW 70S...AND LOWS THU NIGHT IN THE 50S. A
FEW DEGREES COOLER FOR FRI...THOUGH WILL DEPEND ON HOW QUICKLY THE
FRONT PUSHES THROUGH THE AREA.
FRIDAY NIGHT THROUGH SUNDAY...STRONG CAA DEVELOPS BEHIND THE
FRONT THROUGH MUCH OF THE WEEKEND WITH COLD HIGH PRES BUILDING
INTO THE REGION. STRONGEST NW WINDS EXPECTED TO OCCUR SAT
AFTERNOON THROUGH SAT NIGHT COINCIDENT TO THE UPPER TROUGH AXIS
MOVING ACROSS THE REGION. MUCH COLDER AIRMASS WILL BUILD INTO THE
AREA THIS WEEKEND WITH LOWS FRI NIGHT DROPPING INTO THE 30S
INLAND TO 40S COAST AND SAT NIGHT IN THE 30S WITH BELOW FREEZING
TEMPS EXPECTED INLAND. HIGHS SAT AND SUN IN THE UPPER 40S/50
DEGREES.
&&
.AVIATION /08Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 06Z MONDAY/...
AS OF 1 AM MONDAY...DECK OF CLOUDS AROUND 5K FEET CONTINUES BUT
WITH A FEW BREAKS IN THAT DECK...MAY STILL SEE SOME PATCHES OF
MVFR AND PERHAPS IFR FOG THROUGH THE EARLY MORNING HOURS...BUT
OVERALL CLOUD COVER WILL INHIBIT THE FOG A BIT. EXPECT MOSTLY VFR
CONDITIONS THROUGH THE DAY MONDAY UNTIL 06Z MONDAY NIGHT WITH JUST
A FEW SHOWERS IN THE VICINITY OF THE TAF SITES...BUT PROBABLY NOT
HEAVY ENOUGH TO PRODUCE MANY REDUCTIONS IN CEILINGS OR VSBY. S/SW
WINDS WILL INCREASE AND ARE LIKELY TO GUST TO AROUND 20 KNOTS BY
THIS AFTERNOON.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM MON...PRED VFR TUE THRU WED AS HIGH PRES BUILDS INTO
THE AREA...THOUGH LATE NIGHT FOG/STRATUS POSSIBLE WITH LIGHT WINDS
AND GOOD BL MOISTURE. BETTER CHCS OF SUB-VFR WED NIGHT INTO FRI
WITH GOOD CVRG OF SHOWERS EXPECTED AHEAD OF APPROACHING UPR
TRF/SFC COLD FRONT. GRADUALLY IMPROVING CONDITIONS EXPECTED
THROUGH THE DAY FRIDAY AS DEEPER MOISTURE MOVES OFFSHORE.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 320 AM MONDAY...S/SW WINDS ARE RUNNING 10 KNOTS OR LESS THIS
MORNING EXCEPT GUSTING INTO THE UPPER TEENS AT DIAMOND BUOY. THIS
IS DRIVING SEAS OF 2 TO 4 FEET WITH 12-14 SECOND WAVE PERIODS. AS
THE COLD FRONT APPROACHES...WINDS WILL INCREASE TO 20-25 KNOTS
OVER THE COASTAL WATERS BY EARLY AFTERNOON WITH FREQUENT GUSTS TO
25 KNOTS LIKELY ON PAMLICO SOUND THROUGH TONIGHT. SEAS BUILD TO
5-8 FEET CENTRAL AND NORTHERN WATERS WITH 4-6 FEET SOUTHERN WATERS
THIS AFTERNOON THROUGH TONIGHT.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM MON...GUSTY WESTERLY WINDS AND ELEVATED SEAS WILL START
OFF THE PERIOD TUE MORNING. SCA CONDITIONS WILL CONTINUE ACROSS
THE WATERS SOUTH OF OREGON INLET INTO TUESDAY AFTERNOON...GRADUALLY
IMPROVING THROUGH THE DAY AS HIGH PRESSURE BUILDS IN FROM THE
WEST INTO WED. WINDS GRADUALLY DIMINISHING TO BELOW 15 KT TUE
AFTERNOON. SEAS WILL SUBSIDE TO 2 TO 4 FEET LATE TUE AND BY WED
SHLD BE MAINLY AROUND 2 FT. THE NEXT COLD FRONT WILL BE
APPROACHING FROM THE W THU WITH S WINDS INCREASING TO 15 TO 25
KNOTS AND VEERING TO SW THROUGH THE DAY WITH SEAS BUILDING TO 4-8
FT. STRONGEST WINDS AND SEAS EXPECTED ACROSS THE CENTRAL AND
SOUTHERN WATERS WHERE SCA WILL BE LIKELY. A SLIGHT DECREASE IN
WINDS/SEAS EXPECTED THU NIGHT AND FRI AND MAY SEE CONDITIONS
BRIEFLY DROP BELOW SCA CRITERIA. SOME MODEL DIFFERENCES CONTINUE
WITH THE TIMING OF THE FRONTAL PASSAGE FRIDAY BUT EXPECT STRONG
CAA TO DEVELOP BEHIND THE FRONT FRIDAY NIGHT WITH SCA PROBABLE FOR
MOST WATERS FRI NIGHT AND CONTINUING INTO THE WEEKEND.
&&
.CLIMATE...
RECORD MAX TEMPS FOR 12/14 TODAY
LOCATION TEMP/YEAR
NEW BERN 80/1991 (KEWN ASOS)
CAPE HATTERAS 74/1991 (KHSE ASOS)
GREENVILLE 81/1927 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 78/1949 (COOP - NOT KMRH ASOS)
KINSTON 83/1927 (COOP- NOT KISO AWOS)
JACKSONVILLE 80/1991 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 1 PM EST
TUESDAY FOR AMZ152-154-156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...SK/CQD
AVIATION...CTC/CQD
MARINE...CTC/CQD
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
105 AM EST MON DEC 14 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A WEAK COLD FRONT WILL
APPROACH FROM THE WEST MONDAY AND MOVE THROUGH THE REGION MONDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST BEHIND THE FRONT
TUESDAY AND SLIDE OFFSHORE WEDNESDAY. A STRONG COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY AND CROSSES THE AREA LATE THURSDAY
NIGHT OR FRIDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST NEXT
WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1 AM MONDAY...CLOUDINESS CONTINUES TO INCREASE FROM THE SW/W
EARLY THIS MORNING. SOME PATCHES OF FOG ARE POSSIBLE BUT SHOULD BE
INHIBITED A BIT BY THE CLOUD COVER. LATEST RUNS OF THE 3KM HRRR
AND RAP MODELS SHOW NO PRECIPITATION INTO OUR CWA UNTIL AFTER 18Z
TODAY...SO HAVE TWEAKED POPS TO REFLECT THIS. OTHERWISE NO MAJOR
CHANGES NEEDED TO CURRENT FORECAST. LIGHT S/SW WINDS WILL KEEP LOW
TEMPERATURES IN THE UPPER 50S TO LOWER 60S AREA-WIDE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 AM TUESDAY/...
AS OF 230 PM SUNDAY...WEAK COLD FRONT WILL APPROACH FROM THE W
WITH MOISTURE GRAD INCREASING OVER THE AREA. MDLS CONT TO SLOW
ARRIVAL OF SCT SHRA SO DROPPED ALL PRECIP THRU MORN. GIVEN WARM
START AND POSS SOME SUN THRU MORN EXPECT ANOTHER VERY WARM DAY
WITH HIGHS WELL INTO THE 70S. STILL DOESNT LOOK LIKE MUCH PRECIP
WITH THIS SYSTEM SO CONT CHC POPS. WEAK INSTAB STILL DVLPS SO CONT
ISOLD TSRA MENTION. SSW WINDS WILL BECOME GUSTY ESPCLY CST.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
AS OF 315 PM SUN...UNSEASONABLY WARM WEATHER TO CONTINUE THROUGH
THURSDAY THEN MUCH COLDER NEXT WEEKEND.
MONDAY NIGHT...PRECIP WILL TAPER OFF FROM WEST TO EAST MONDAY
EVENING WITH A WEAK COLD FRONT MOVING THROUGH AFTER MIDNIGHT AND
CLEARING SKIES LATE. LIMITED CAA BEHIND FRONT WILL KEEP LOWS
MILD WITH MID 50S INLAND TO UPR 50S CST.
TUESDAY THROUGH WEDNESDAY...WEAK HIGH PRESSURE BUILDS ACROSS FROM
THE WEST AS UPR RDG RE-BUILDS OVER REGION. MILD AND DRY WEATHER
WITH HIGHS UPR 60S TO LOW 70S AND LOWS MID 40S INLAND TO LOWER
50S CST.
WEDNESDAY NIGHT THROUGH FRIDAY...MOISTURE SURGES NE INTO REGION
WED NIGHT AHEAD OF DEEP BROAD UPPER TROF AND COLD FRONT TO THE W.
CHC POPS PROGGED TO DEVELOP LATER WED NIGHT ESPCLY INLAND. PRECIP
CONT OVER REGION THU INTO THU NIGHT WITH MOST MDLS SHOWING PLENTY
OF MOISTURE AND QPF. MODEL DIFFERENCES CONTINUE WITH JUST HOW
QUICKLY THE FRONT PUSHES THROUGH THE AREA AND DEEPER MOISTURE
MOVES OFFSHORE LATE THU NIGHT AND FRI WITH SW FLOW CONTINUING
ALOFT AND THE UPPER TROF AXIS REMAINING W OF THE REGION.
ULTIMATELY IT WILL DEPEND ON THE TIMING OF AN EMBEDDED SHORTWAVE
MOVING THROUGH THE SW FLOW ALOFT. 12Z MODELS ARE A BIT SLOWER
PUSHING THE FRONT THROUGH AND DEEPER MOISTURE OFFSHORE AND HAVE
CONTINUED CHC POPS FRI MORNING WITH GRADUAL CLEARING FROM THE WEST
THROUGH THE AFTERNOON. IT WILL REMAIN MILD AHEAD OF FRONT WITH
HIGHS THU AGAIN MAINLY 65 TO 70 AND LOWS WED NIGHT AND THU NIGHT
IN THE 50S.
FRIDAY NIGHT THRU SUNDAY...STRONG CAA DEVELOPS BEHIND THE FRONT
THROUGH MUCH OF THE WEEKEND WITH COLD HIGH PRES BUILDING INTO THE
REGION. STRONGEST NW WINDS EXPECTED TO OCCUR SAT AFTERNOON
THROUGH SAT NIGHT COINCIDENT TO THE UPPER TROUGH AXIS MOVING
ACROSS THE REGION. MUCH COLDER AIRMASS WILL BUILD INTO THE AREA
FOR THE WEEKEND WITH LOWS FRI NIGHT DROPPING INTO THE 30S INLAND
TO 40S COAST AND SAT NIGHT IN THE 30S WITH BELOW FREEZING TEMPS
EXPECTED INLAND. HIGHS SAT EXPECTED TO BE AROUND 50 WITH MID TO
UPPER 40S ON SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 06Z MONDAY/...
AS OF 1 AM MONDAY...DECK OF CLOUDS AROUND 5K FEET CONTINUES BUT
WITH A FEW BREAKS IN THAT DECK...MAY STILL SEE SOME PATCHES OF
MVFR AND PERHAPS IFR FOG THROUGH THE EARLY MORNING HOURS...BUT
OVERALL CLOUD COVER WILL INHIBIT THE FOG A BIT. EXPECT MOSTLY VFR
CONDITIONS THROUGH THE DAY MONDAY UNTIL 06Z MONDAY NIGHT WITH JUST
A FEW SHOWERS IN THE VICINITY OF THE TAF SITES...BUT PROBABLY NOT
HEAVY ENOUGH TO PRODUCE MANY REDUCTIONS IN CEILINGS OR VSBY. S/SW
WINDS WILL INCREASE AND ARE LIKELY TO GUST TO AROUND 20 KNOTS BY
THIS AFTERNOON.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 3 PM SUN...PERIODS OF SUB-VFR CIGS WITH A FEW SHOWERS MAY
LINGER INTO MONDAY EVENING BUT GENERALLY EXPECT CLEARING
CONDITIONS OVERNIGHT. PRED VFR TUE THRU WED AS HIGH PRES BUILDS
INTO THE AREA...THOUGH LATE NIGHT FOG/STRATUS POSSIBLE WITH LIGHT
WINDS AND GOOD BL MOISTURE. BETTER CHCS OF SUB-VFR WED NIGHT INTO
EARLY FRI WITH GOOD CVRG OF SHOWERS EXPECTED AHEAD OF APPROACHING
UPR TRF/SFC COLD FRONT. GRADUALLY IMPROVING CONDITIONS EXPECTED
THROUGH THE DAY FRIDAY AS DEEPER MOISTURE OFFSHORE.
&&
.MARINE...
SHORT TERM /THROUGH MON/...
AS OF 105 AM MONDAY...LIGHT S/SW WINDS CONTINUE AT 10 KNOTS OR
LESS EXCEPT WITH GUSTS TO AROUND 15 KNOTS AT DIAMOND BUOY. SEAS
ARE IN THE 2 TO 4 FOOT RANGE WITH STILL SOME 11-13 SECOND
SWELLS...ESPECIALLY CENTRAL AND NORTHERN WATERS. NO BIG CHANGES TO
THE FORECAST AS WINDS GRADUALLY INCREASE ON MONDAY AS A COLD FRONT
APPROACHES...WITH 20 TO 25 KTS MOST WTRS BY MONDAY AFTERNOON. SEAS
SHOULD BUILD THRU THE DAY REACHING 6 TO 8 FEET OUTER WTRS.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 3 PM SUN...SCA CONDITIONS EXPECTED TO CONTINUE ACROSS
PORTIONS OF THE WATERS MON NIGHT THROUGH TUE MORNING. SSW WINDS
AROUND 15-25 KT VEER TO SW MON EVENING...THEN TO W AFTER FROPA
LATE MON NIGHT...THEN GRADUALLY DIMINISH THROUGH THE DAY TUE. SEAS
EXPECTED TO PEAK AROUND 5-8 FT MON NIGHT...THE SUBSIDE TO BLO 6 FT
TUE AFTERNOON.
HIGH PRES WILL BUILD ACROSS THE WATERS LATE TUE THROUGH WED WITH
WINDS DIMINISHING TO BELOW 15 KT. SEAS WILL SUBSIDE TO 2 TO 4
FEET LATE TUE AND BY WED SHLD BE MAINLY AROUND 2 FT. THE NEXT COLD
FRONT WILL BE APPROACHING FROM THE W THU WITH S WINDS INCREASING
TO 15 TO 25 KNOTS AND VEERING TO SW THROUGH THE DAY WITH SEAS
BUILDING TO 4-7 FT. STRONGEST WINDS AND SEAS EXPECTED ACROSS THE
CENTRAL AND SOUTHERN WATERS WHERE SCA WILL BE LIKELY. A SLIGHT
DECREASE IN WINDS/SEAS EXPECTED THU NIGHT AND FRI AND MAY SEE
CONDITIONS BRIEFLY DROP BELOW SCA CRITERIA. SOME MODEL DIFFERENCES
CONTINUE WITH THE TIMING OF THE FRONTAL PASSAGE FRIDAY BUT EXPECT
STRONG CAA TO DEVELOP BEHIND THE FRONT FRIDAY NIGHT WITH SCA
PROBABLE MOST WATERS FRI NIGHT AND CONTINUING INTO THE WEEKEND.
&&
RECORD MAX TEMPS FOR 12/14 MONDAY
LOCATION TEMP/YEAR
NEW BERN 80/1991 (KEWN ASOS)
CAPE HATTERAS 74/1991 (KHSE ASOS)
GREENVILLE 81/1927 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 78/1949 (COOP - NOT KMRH ASOS)
KINSTON 83/1927 (COOP- NOT KISO AWOS)
JACKSONVILLE 80/1991 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO NOON EST
TUESDAY FOR AMZ152-154-156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF/JBM
LONG TERM...SK/CQD
AVIATION...CTC/JBM
MARINE...CTC/JBM/SK
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
404 AM CST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 14 2015
HIGHLIGHTS IN THE SHORT TERM INCLUDE: THE CURRENT DENSE FOG ADVISORY
VALID THROUGH THIS MORNING...THE ISSUANCE OF A WINTER STORM WATCH
FAR SOUTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA INCLUDING THE JAMES
RIVER VALLEY TUESDAY THROUGH WEDNESDAY.
THE LATEST SUITE OF SATELLITE IMAGERY ALONG WITH SURFACE
OBSERVATIONS/WEBCAMS STILL SIGNAL THE NEED FOR A DENSE FOG ADVISORY.
THERE AS BEEN SOME IMPROVEMENT IN THE JAMES RIVER VALLEY WITH
VISIBILITIES BETWEEN 1 AND 3 MILES DUE TO A SHIELD OF THICK MID/HIGH
CLOUDS SHIFTING FROM EAST TO WEST INTO THIS AREA. HOWEVER
EXPECTATIONS PER LATEST HRRR IS THAT THIS AREA WILL FILL IN AGAIN
TOWARD 12Z. WITH THAT IN MIND...WILL LET THE DENSE FOG ADVISORY IN
THE JAMES RIVER VALLEY RIDE FOR NOW AND GIVE IT ANOTHER LOOK DURING
THE 6AM-7AM FORECAST UPDATE. OTHERWISE...EXPECT CLOUDS TO LIFT A
COUPLE HUNDRED FEET THIS AFTERNOON FROM CURRENT LEVELS AS VISIBILITIES
SLOWLY IMPROVE...BUT REMAINING CLOUDY THROUGH THE SHORT TERM WITH
AREAS OF FOG AGAIN TONIGHT.
WATER VAPOR IMAGERY SHOWS OUR NEXT UPPER LOW SHIFTING INTO NORTHERN
NEVADA EARLY THIS MORNING...AND WILL TRANSLATE EAST INTO COLORADO
TONIGHT BEFORE EJECTING NORTHEAST INTO SOUTHERN MINNESOTA BY 12Z
WEDNESDAY. AHEAD OF THIS UPPER LOW...PERSISTENT LOW CLOUDS/FOG AND
AN INCREASE IN VERTICAL MOTION WITHIN THE SATURATED LAYER/-10C AND
WARMER...WILL LEAD TO A SLIGHT CHANCE OF VERY LIGHT FREEZING DRIZZLE
AND/OR VERY LIGHT SNOW ACROSS CENTRAL NORTH DAKOTA. THIS WAS
MENTIONED IN THE PREVIOUS FORECASTS AND BUFKIT SOUNDINGS CONTINUE
WITH THIS IDEA.
AFTER A SNOW COLLABORATION CALL WITH WPC WWD AND SURROUNDING
OFFICES...WE DECIDED ON A WINTER STORM WATCH FAR SOUTHWEST INTO
SOUTH CENTRAL NORTH DAKOTA. UNLESS THERE IS A CHANGE WITH THE
OVERALL TRACK RESULTING IN AN INCREASE OF SNOWFALL TOTALS BY ONE OR
TWO INCHES...THEN THE LIKELY SCENARIO WILL BE FOR THE EXISTING
WINTER STORM WATCH TO BE CONVERTED INTO A WINTER WEATHER ADVISORY
ADVERTISING 3 TO 6 INCH SNOWFALL TOTALS. GIVEN WE ARE STILL ABOUT
36HRS OUT AND THERE REMAINS ENOUGH UNCERTAINTY WITHIN THE WATCH AREA
FOR AT LEAST A 50 PERCENT CHANCE OR GREATER OF MEETING WARNING
CRITERIA/6 INCHES OR MORE...IT MADE MORE SENSE AT THIS STAGE TO
ISSUE A WINTER STORM WATCH AND THEN BEGIN CHISELING AWAY DURING THE
DAY TODAY INTO TONIGHT FOR THE EXACT DETAILS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 14 2015
THE MAIN FORECAST HIGHLIGHT IN THE EXTENDED PERIOD CONTINUES TO BE
THE DEVELOPING UPPER LEVEL TROUGH CURRENTLY OVER THE WESTERN U.S.
AND RESULTING SURFACE CYCLONE THAT DEVELOPS OVER THE CENTRAL ROCKIES
AND TRACKS NORTHEAST INTO THE UPPER GREAT LAKES TUESDAY THROUGH
WEDNESDAY.
DETERMINISTIC MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH THE
EVOLUTION OF THE MASS FIELDS WITH THIS SYSTEM. AFTER COORDINATION
WITH WPC...A ECMWF/GFS BLEND WAS UTILIZED FOR TIMING/PLACEMENT OF
FEATURES AND QPF FORECAST.
SEE THE SHORT TERM DISCUSSION FOR A DETAILED REASONING FOR
HIGHLIGHTS WITH THIS SYSTEM.
WE BEGIN THE EXTENDED PERIOD ON TUESDAY AS THE SURFACE LOW IS JUST
EJECTING INTO THE CENTRAL PLAINS. ALTHOUGH THE MAIN ENERGY IS
CONFINED TO THE SOUTHERN PORTION OF THE UPPER LEVEL TROUGH...THERE
REMAINS SOME ENERGY IN THE NORTHERN STREAM AND FORCING ASSOCIATED
WITH THIS ENERGY IS ABLE TO OVERCOME THE INITIAL DRY UPPER LEVELS IN
THE FAR WEST WITH SNOW BEGINNING TUESDAY MORNING. DURING THE DAY
TUESDAY THE ENERGY TRANSITIONS SOUTHEAST TOWARD THE SOUTHERN SYSTEM.
THUS IT LOOKS LIKE THE FAR SOUTHWEST COULD SEE A PERIOD OF SNOW
BEGINNING TUESDAY AND CONTINUING THROUGH TUESDAY NIGHT. THINK
ACCUMULATIONS ARE GENERALLY GOING TO BE LESS THAN 3 INCHES...BUT THE
FAR SOUTHWEST...WITH SOME ENHANCED UPSLOPE FLOW COULD SEE SOME
ADDITIONAL ACCUMULATION...PUSHING TOTALS MORE INTO THE 4-6 INCH
RANGE. THUS THE REASON FOR THE WATCH IN THE FAR SOUTHWEST. FARTHER
EAST...SNOW IS NOT EXPECTED TO GET UNDER WAY UNTIL THE AFTERNOON OR
EVENING. HOWEVER...WITH OUR SATURATED NEAR SURFACE LAYER...AND SOME
OMEGA LOCATED IN THIS LAYER...WILL CONTINUE TO ADVERTISE A MENTION
OF FREEZING DRIZZLE DURING THE DAY TUESDAY.
THE MAIN FORCING WITH THE CYCLONE WILL OCCUR TUESDAY NIGHT. STARTING
IN THE FAR SOUTH CENTRAL POSSIBLY LATE AFTERNOON TUESDAY...BUT FOR
THE MOST PART TUESDAY EVENING. AND LIFTING NORTH NORTHEAST ACROSS
MAINLY THE EASTERN PORTION OF CENTRAL NORTH DAKOTA THROUGH THE
NIGHT. ON WEDNESDAY...THE MAIN SURFACE LOW LIFTS FROM SOUTHERN
MINNESOTA TO NEAR LAKE SUPERIOR...BUT TRAILING DEFORMATION ZONE
TRACKS SLOWLY EAST ACROSS CENTRAL NORTH DAKOTA...KEEPING THE THREAT
OF ACCUMULATING SNOW OVER CENTRAL NORTH DAKOTA THROUGH THE DAY
WEDNESDAY. ALTHOUGH WE DO EXPECT ACCUMULATING SNOW TO TAPER OFF
FROM WEST TO EAST DURING THE DAY. WINDS WITH THIS SYSTEM ARE NOT
EXPECTED TO BE TERRIBLY STRONG...MAINLY 10 TO 20 MPH DURING THE
PEAK ACCUMULATION PERIOD OF TUESDAY NIGHT...BUT INCREASING TO THE
15 TO 25 MPH RANGE ON WEDNESDAY. THUS...WE COULD SEE SOME BLOWING
AND DRIFTING ON WEDNESDAY...BUT NOT EXPECTING A SIGNIFICANT
PROBLEM WITH BLOWING AND DRIFTING SNOW.
BEYOND THE TUESDAY-WEDNESDAY SYSTEM...COLD AIR GETS PULLED INTO THE
REGION...BRINGING A COOLING TREND WITH HIGHS IN THE 10 TO 20 ABOVE
RANGE AND LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO AS WE MOVE
TO THE END OF THE WORK WEEK. THEN A BUILDING WESTERN RIDGE SHOULD
BRING MODERATING TEMPERATURES BY THE END OF THE WEEKEND.
LITTLE SIGNIFICANT PRECIPITATION IS EXPECTED BEYOND WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 352 AM CST MON DEC 14 2015
ALL TERMINALS WILL CONTINUE TO EXPERIENCE A COMBINATION OF
LIFR/VLIFR CIGS...AND VSBYS RANGING BETWEEN MVFR TO VLIFR THROUGH
18Z MONDAY. A DENSE FOG ADVISORY REMAINS IN EFFECT WHICH COVERS
ALL TERMINALS EXCEPT KISN THROUGH 17Z. PATCHY LIGHT FREEZING
DRIZZLE POSSIBLE AT ANYTIME WITH THE STRATUS AND FOG DECK IN
PLACE. CIGS/VSBYS WILL IMPROVE SOMEWHAT AT MOST TERMINALS AFTER
18Z MONDAY...HOWEVER IFR CIGS EXPECTED THROUGH THE TAF PERIOD WITH
AREAS OF FOG RETURNING AFTER 00Z TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST /10 AM MST/ THIS MORNING FOR
NDZ003>005-010>013-018>023-025-031>037-040>048-050-051.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR NDZ013-020-022-023-025-034>037-042-045>048-050-051.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR NDZ043-044.
&&
$$
SHORT TERM...KS
LONG TERM...TWH
AVIATION...KS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1158 PM CST SUN DEC 13 2015
.UPDATE...
ISSUED AT 1158 PM CST SUN DEC 13 2015
LATEST SUITE OF SATELLITE IMAGERY AND SURFACE OBSERVATIONS IN
CONJUNCTION WITH THE HRRR CEILING AND VISIBILITY FORECAST IS ON
TRACK FOR THE OVERNIGHT PERIOD INTO MONDAY MORNING. EXPECTING THE
FAR NORTHWEST...WHICH INCLUDES WILLISTON...TO SUCCUMB TO THE
STRATUS AND FOG BY 10-11Z. NO CHANGES TO THE ONGOING DENSE FOG
ADVISORY.
UPDATE ISSUED AT 920 PM CST SUN DEC 13 2015
THE FORECAST FOR THE OVERNIGHT REMAINS ON TRACK AND BLENDED TO
OBSERVED TRENDS THROUGH 02-03 UTC. TEMPERATURES ACROSS THE TURTLE
MOUNTAINS INTO THE FAR UPPER JAMES RIVER BASIN HAVE LOCALLY
DROPPED INTO THE 10 TO 20 DEGREE RANGE. HOWEVER...THEY ARE
EXPECTED TO SLOWLY RISE THROUGH THE REMAINDER OF THE NIGHT.
UPDATE ISSUED AT 603 PM CST SUN DEC 13 2015
DID ADD A PATCHY FREEZING DRIZZLE MENTION FOR MOST AREAS WITH
SATURATION WARMER THAN -10C...AND FAVORABLE WEAK EASTERLY UPSLOPE
FLOW. OTHERWISE...NO CHANGES NEEDED AS THE 20-22 UTC HRRR
ITERATIONS SUPPORT THE DENSE FOG CONTINUING THROUGH MONDAY
MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 325 PM CST SUN DEC 13 2015
MAIN CONCERNS CONTINUE TO BE DENSE FOG. PERSISTENCE SOUTHEAST LOW
LEVEL FLOW CONTINUES TO BE PORTRAYED BY NAM/GFS. EXPECT FOG WILL
REMAIN OR RETURN TO NEARLY ALL OF WEST AND CENTRAL NORTH DAKOTA
BY THIS EVENING AND OVERNIGHT.
HAVE ISSUED A DENSE FOG ADVISORY FOR ALL BUT THE FAR NORTHWEST
WHERE THE COOL MOIST BOUNDARY LAYER MAY NOT QUITE GET PUSHED INTO
THE AREA.
GOT A REPORT LIGHT DRIZZLE IN THE BISMARCK AREA AND WITH UPPER 70S
DEFINED AN AREA ACROSS CENTRAL NORTH DAKOTA WHERE VSBYS WILL BE
LOWEST THIS EVENING AND ADDED PATCHY FREEZING DRIZZLE. EVEN
WITHOUT THE FREEZING DRIZZLE FEEL THERE WOULD BE SUFFICIENT RIME
FOR SLIPPERY ROAD AS WELL.
MESO MODELS...HRRR/NAMNEST...SHOWING SOME VERY LIGHT QPF WEST
CENTRAL THIS EVENING. ADDED A SLIGHT CHANCE FOR FREEZING RAIN FAR
WEST CENTRAL TONIGHT THAT MATCHES UP WITH GLASGOW.
THE FOG WILL PERSIST INTO MONDAY WITH LITTLE CHANGE IN
TEMPERATURES.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 325 PM CST SUN DEC 13 2015
THE HIGHLIGHT IN THE LONG TERM IS A STRONG STORM SYSTEM OVER THE
WEST COAST TODAY THAT IS EXPECTED TO CONTINUE TO DEVELOP...AND BRING
A STRONG STORM SYSTEM TO MUCH OF THE US THROUGH THE UPCOMING WEEK.
THIS SYSTEM WILL AFFECT WESTERN AND CENTRAL NORTH DAKOTA FROM MONDAY
NIGHT THROUGH WEDNESDAY NIGHT.
MONDAY NIGHT THE STRATUS AND LOW CLOUDS THAT HAVE PLAGUED THE AREA
THIS WEEKEND WILL STILL LINGER OVER CENTRAL NORTH DAKOTA. THE MODELS
ARE INDICATING SOME VERY LIGHT PRECIPITATION POSSIBLE AHEAD OF THE
ANTICIPATED STORM SYSTEM. THERE IS WEAK UPWARD MOTION IN THE
MODELS...AND WITH THE LACK OF MID LEVEL CLOUDS ALOFT AND BELOW
FREEZING TEMPERATURE PROFILES...EXPECT A LOWER LEVEL SUPERCOOLED
LAYER WITHIN THE STRATUS. BUFKIT SOUNDINGS SUPPORT THIS AND THUS
HAVE A MENTION OF AREAS OF FOG AND PATCHY FREEZING DRIZZLE MONDAY
NIGHT INTO TUESDAY MORNING FOR CENTRAL NORTH DAKOTA.
MONDAY NIGHT THE UPPER LEVEL TROUGH MOVES THROUGH THE SOUTHERN
ROCKIES WITH A SURFACE LOW DEVELOPING IN THE LEE OF THE COLORADO
ROCKIES. DETERMINISTIC MODELS ARE IN PRETTY GOOD AGREEMENT AT 12 UTC
TUESDAY WITH THE SURFACE AND 50H LOWS OVER THE PLAINS OF EASTERN
COLORADO. THE LOW TRACK MOVES NORTHEAST TO THE BORDER OF SD/MN/IA BY
DAYBREAK WEDNESDAY...AND ACROSS LAKE SUPERIOR INTO ONTARIO BY
DAYBREAK THURSDAY.
THE BEST FRONTOGENETICAL FORCING MOVES THROUGH THE FAR SOUTH CENTRAL
AND INTO THE JAMES RIVER VALLEY AND DEVILS LAKE BASIN TUESDAY NIGHT
THROUGH WEDNESDAY MORNING...WITH THE DEFORMATION ZONE THEN SLOWLY
FADING FROM WEST TO EAST DURING THE DAY WEDNESDAY. WINDS WILL ALSO
PICK-UP ON THE BACK SIDE OF THE SURFACE SYSTEM ON WEDNESDAY BRINGING
A POSSIBILITY OF SOME BLOWING AND DRIFTING SNOW.
THE LATEST PRECIPITATION CONSENSUS WOULD BRING SNOW AMOUNTS IN THE
SOUTHWEST OF 3 TO 5 INCHES...OVER A PERIOD FROM MONDAY NIGHT THROUGH
WEDNESDAY - A 36-HOUR PERIOD OR SO. IN SOUTH CENTRAL NORTH
DAKOTA...HEAVIER SNOW TOTAL AMOUNTS OF 4 TO 7 INCHES ARE POSSIBLE IN
FROM A 36-HOUR PERIOD FROM TUESDAY THROUGH WEDNESDAY AFTERNOON. WILL
ISSUE A SPECIAL WEATHER STATEMENT REGARDING THE POTENTIAL WINTER-
TYPE PRECIPITATION/HAZARDS THAT MAY AFFECT MAINLY THE SOUTHERN HALF
OF OUR WESTERN/CENTRAL NORTH DAKOTA FORECAST AREA.
BEYOND THE MONDAY NIGHT-WEDNESDAY SYSTEM...COLD AIR GETS PULLED INTO
THE REGION...BRINGING A COOLING TREND WITH HIGHS IN THE 10 TO 20
ABOVE RANGE AND LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO AS WE
MOVE TO THE END OF THE WORK WEEK. THEN A BUILDING WESTERN RIDGE
SHOULD BRING MODERATING TEMPERATURES BY THE END OF THE WEEKEND.
LITTLE SIGNIFICANT PRECIPITATION IS EXPECTED BEYOND WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1158 PM CST SUN DEC 13 2015
ALL TERMINALS EXCEPT KISN WILL CONTINUE TO HAVE LIFR/VLIFR CIGS
AND VSBYS RANGING BETWEEN IFR TO VLIFR THROUGH 18Z MONDAY. A
DENSE FOG ADVISORY IS IN EFFECT WHICH COVERS ALL TERMINALS EXCEPT
KISN AT THIS TIME. PATCHY LIGHT FREEZING DRIZZLE POSSIBLE AT
ANYTIME WITH THE STRATUS AND FOG DECK. CONDITIONS AT KISN WILL
DETERIORATE BY 10-11Z MONDAY...WITH LIFR CIGS AND MVFR VSBYS.
CIGS/VSBYS WILL IMPROVE SOMEWHAT AT MOST TERMINALS AFTER 18Z
MONDAY WITH IFR CIGS EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST /10 AM MST/ MONDAY FOR
NDZ003>005-010>013-018>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...KS
SHORT TERM...WAA
LONG TERM...JV
AVIATION...KS
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1145 PM CST SUN DEC 13 2015
.UPDATE...
ISSUED AT 1145 PM CST SUN DEC 13 2015
ADDED FREEZING DRIZZLE POTENTIAL TO AREAS IN DENSE FOG ADVISORY
AFTER RECEIVING REPORT. INCLUDED IN BOTH THE GRIDS AND MENTIONED
IN THE DENSE FOG ADVISORY PRODUCT.
UPDATE ISSUED AT 917 PM CST SUN DEC 13 2015
TRIMMED DENSE FOG ADVISORY...LEAVING THE AREA OF GWINNER TO
LANGDON AND WEST BASICALLY. NOT SEEING MUCH EVIDENCE OF EASTWARD
EXPANSION...SO BELIEVE THAT TREND WILL CONTINUE AS PRESSURES FALL.
MOST FAVORABLE AREA FOR FOG WILL BE IN THE DEVILS LAKE BASIN WHERE
HIGH EXISTS AND WILL BE RETREATING NORTHWARD. DRIZZLE HAS BEEN
REPORTED ALSO IN PARTS OF THE RED RIVER VALLEY...WILL BE
MONITORING FOR FREEZING POTENTIAL.
UPDATE ISSUED AT 712 PM CST SUN DEC 13 2015
FORECAST LARGELY UNCHANGED WITH THIS UPDATE. ADDED PATCHY FREEZING
DRIZZLE TO FAR SE ND BASED ON REPORT. OTHERWISE...MAIN CONCERN
WILL BE EXTENT OF FOG OVER THE NEXT SEVERAL HOURS. OBSERVATIONS
HAVE INDICATED VISIBILITIES HAVE IMPROVED ACROSS THE I-29
CORRIDOR OVER THE PAST FEW HOURS. LATEST HRRR HAS AREA OF FOG
EXPANDING EASTWARD AGAIN. HOWEVER...WITH HIGH PRESSURE RIDGE AXIS
OVER DEVILS LAKE TO JAMESTOWN AND LOW PRESSURE MOVING INTO THE
AREA...THE GENERAL TREND OVER THE NEXT 12-18 HRS SHOULD BE FOR
IMPROVING CONDITIONS. SO WILL MONITOR TRENDS AND LATEST MODEL RUNS
AND CONSIDER TRIMMING ADVISORY IN THE NEXT COUPLE OF HOURS.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY NIGHT)
ISSUED AT 235 PM CST SUN DEC 13 2015
MAIN FORECAST CHALLENGE IN THE VERY NEAR TERM WILL BE THE THICKER
FOG THAT CONTINUES OVER PORTIONS OF THE FA. HAVE A DENSE FOG
ADVISORY OUT FOR PORTIONS OF THE FA AND WILL LIKELY HAVE TO
CONTINUE IT INTO TONIGHT AS WELL. TEMP/DEW POINT SPREADS REMAIN
VERY TIGHT AND WINDS LOOK TO REMAIN LOW. HIGH TEMPS GET UP RIGHT
AROUND 32F AGAIN ON MONDAY. THIS TIME WIND SPEEDS MAY BE HIGH
ENOUGH TO MIX OUT THE FOG. HOWEVER AT THIS POINT DID LEAVE PATCHY
FOG MENTIONED. THESE WINDS DO LIGHTEN UP AGAIN MON NIGHT.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 235 PM CST SUN DEC 13 2015
NEXT SYSTEM BEGINS TO MOVE TOWARD THE FA ON TUE...BUT WILL ONLY
MAINTAIN PCPN CHANCES INTO THE SW. SFC LOW TRACKS FROM SW MN ON
12Z WED TO WESTERN LAKE SUPERIOR BY 00Z THU. MODELS SEEM FAIRLY
CONSISTENT ON PUSHING A DECENT SWATH OF SNOW THROUGH MOST OF THE
FA DURING THIS TIME FRAME...WITH THE LEAST WEST OF THE KDVL
REGION. WIND SPEEDS ALSO LOOK PRETTY GUSTY AS WELL. THE STEADIER
SNOW LIFTS NORTH AND EAST OF THE FA WED NIGHT INTO THU NIGHT BUT
SOME GUSTY WINDS WILL REMAIN. THIS SHOULD LEAD TO SOME BLOWING AND
DRIFTING SNOW. WILL ISSUE A SPECIAL WEATHER STATEMENT TO
HIGHLIGHT THIS SYSTEM AND WILL WATCH AND SEE WHAT LATER RUNS HAVE
IN STORE.
FOR WED NIGHT THROUGH SUNDAY...THE POTENTIAL WINTER STORM WILL BE
WINDING DOWN WED NIGHT/THU. THE GFS MOVES THE STORM THROUGH A BIT
FASTER AND MOST OF THE ACCUMULATION WOULD BE DONE BY WED
NIGHT...WITH THE ECMWF A BIT SLOWER. WILL CONTINUE WITH THE ALLBLEND
SOLUTION. TEMPS WILL BE MUCH COOLER FOR FRI/SAT AND SHOULD BE BELOW
ZERO AT NIGHT GIVEN COLD AIRMASS AND FRESH SNOW. TEMPS SHOULD START
TO WARM BACK UP ABOVE NORMAL SUNDAY WITH UPPER RIDGING AND 850MB
TEMPS ABOVE 0C.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1145 PM CST SUN DEC 13 2015
CIGS WILL FLUCTUATE BETWEEN MVFR AND VLIFR AT MOST TAF SITES
TONIGHT. BELIEVE KDVL WILL STAY DOWN THOUGH...AND MAY SEE SOME
BRIEF -FZDZ YET TONIGHT. VIS WILL LIKELY STAY UP AT ALL BUT KDVL
AS PER LATEST GUIDANCE. MODELS POINT TOWARD CIGS IMPROVING TO
MVFR TODAY..MAINLY THIS AFTERNOON. HOWEVER...POTENTIAL WILL EXIST
FOR IFR CONDITIONS ONCE AGAIN MONDAY NIGHT.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...DENSE FOG ADVISORY UNTIL 11 AM CST MONDAY FOR NDZ006-007-014-015-
024-026-028-029-038-049-052-054.
MN...NONE.
&&
$$
UPDATE...KNUTSVIG
SHORT TERM...GODON
LONG TERM...GODON/DK
AVIATION...KNUTSVIG
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
307 AM EST MON DEC 14 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY AS DEEP LOW
PRESSURE MOVES ACROSS THE CENTRAL GREAT LAKES. HIGH PRESSURE WILL
BUILD OVER THE AREA FROM THE SOUTH TUESDAY INTO WEDNESDAY. ANOTHER
COLD FRONT IS EXPECTED TO CROSS THE REGION ON THURSDAY.
&&
.NEAR TERM /THROUGH TODAY/...
DEEP LOW PRESSURE OVER IOWA AT 12Z TODAY WILL CONTINUE ENE ACROSS
THE CENTRAL GREAT LAKES. A COLD FRONT ASSOCIATED WITH THE LOW WILL
MOVE EAST ACROSS THE AREA TODAY REACHING KCLE BY ABOUT 18Z AND
EAST OF THE AREA BY 22Z. NAM12 AND HRRR SHOW RAIN MOVING INTO THE
WESTERN COUNTIES AROUND 12Z...SPREADING EAST ACROSS THE AREA
THROUGH THE MORNING AND REACHING INTO NWRN PA AROUND NOON. WILL
CONTINUE WITH CAT POPS FOR THE REGION TODAY. 850MB JET INCREASES
TO ABOUT 60 KNOTS AROUND 12Z FALLING SLOWLY THROUGH THE DAY. WINDS
SHOULD GET GUSTY LATE MORNING AND AFTERNOON IN THE COLD ADVECTION.
EXPECTING GUSTS INTO THE 30 TO 40 KNOT RANGE BUT SHOULD REMAIN
BELOW ADVISORY CRITERIA. HIGHS IN THE 60S WITH FALLING TEMPS
WEST HALF MID/LATE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
THE COLD FRONT WILL BE EAST OF THE AREA BY 00Z WHILE THE LOW WILL
BE CENTERED ACROSS THE CENTRAL GREAT LAKES. MAIN CONCERN FOR THE
EVENING HOURS WILL BE WRAP AROUND MOISTURE SUPPORTING LIGHT RAIN
ACROSS THE AREA BEFORE THE SYSTEM PULLS NORTHEAST. WILL BEGIN THE
EVENING WITH CHANCE POPS FOR LIGHT RAIN MOST AREAS AND LIKELY POPS
NORTHEAST. BY 12Z TUESDAY BEST MOISTURE WILL BE WELL NORTHEAST
HOWEVER THE CORE OF THE COOL AIR WILL BE ACROSS THE AREA WITH
850MB TEMPS AROUND 0C WHICH WILL NOT BE LOW ENOUGH FOR LAKE EFFECT
SO WILL BEGIN WITH ONLY A SLIGHT CHANCE IN THE GRAPHICS AND TAPER
TO NO POPS BY 18Z. HIGH PRESSURE WILL CROSS THE AREA TUESDAY NIGHT
INTO WEDNESDAY. WILL CONTINUE WITH A DRY FORECAST THROUGH
WEDNESDAY EXCEPT FOR A SMALL CHANCE FAR NORTHWEST WEDNESDAY
AFTERNOON. WEDNESDAY AFTERNOON MODELS SHOW ANOTHER COLD FRONT ON
OUR DOORSTEP...ASSOCIATED WITH LOW PRESSURE MOVING NORTHEAST
THROUGH MINNESOTA. WHILE THERE IS NOT A LOT OF MOISTURE WITH THE
FRONT...MODELS SHOW A SIGNIFICANT TEMP DROP...BACK TO NEAR
NORMAL...WITH 850MB TEMPS DROPPING TO -6 TO -8C BY FRIDAY 00Z.
WILL HAVE CHANCE POPS FOR RAIN WEDNESDAY NIGHT DRYING OUT WEST FOR
THURSDAY. WILL CONTINUE CHANCE POPS EAST THROUGH THURSDAY AS MORE
MOISTURE GETS PULLED NORTH INTO THE SYSTEM. WILL TRANSITION TO
LAKE EFFECT RAIN/SNOW THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN TRENDING TOWARD A WINTER TREND FOR A SHORT
PERIOD AS A DEEP DIGGING UPPER LEVEL TROUGH DIGS INTO THE EASTERN
UNITED STATES BY WEEKS END. THE TROUGH WILL SHIFT OFF THE EAST COAST
BY THE END OF THE WEEKEND AS MASSIVE UPPER LEVEL RIDGE BEGINS TO
BUILD BACK INTO THE AREA FROM THE WEST. THIS WILL KEEP THE TREND OF
MILD TEMPERATURES ONCE WE HEAD INTO THE WEEKEND. TEMPERATURES ARE
EXPECTED TO QUICKLY RECOVER INTO EARLY NEXT WEEK.
IN THE MEAN TIME...COLD FRONT IS PROGGED TO MOVE EAST ACROSS THE
AREA THURSDAY. THIS WILL BEGIN THE INFLUX OF COOLER AIR. BUT THE
TRUE COLD AIR REALLY DOES NOT ARRIVE UNTIL FRIDAY MORNING. AT THIS
TIME...I ANTICIPATE THE HIGH TEMPERATURE WILL PROBABLY OCCUR DURING
THE MORNING HOURS AND TEMPERATURES WILL BEGIN TO FALL SLOWLY THROUGH
THE DAY INTO FRIDAY NIGHT. LOOKING AT TEMPERATURES IN THE LOWER 30S
FOR HIGHS FRIDAY. FLOW BEGINS TO BECOME WELL ALIGNED FRIDAY INTO
SATURDAY AND DEEP MOISTURE IS EXPECTED TO REMAIN PRESENT DURING THIS
TIME PERIOD ALONG WITH UPPER LEVEL POSITIVE VORTICITY ADVECTION AND
COLD AIR ADVECTION. THIS SHOULD GET THE LAKE SNOW MACHINE GOING OVER
NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY THROUGH SATURDAY.
DUE TO THE SYNOPTIC MOISTURE BEING PRESENT...SNOW SHOWERS ARE
EXPECTED FRIDAY NIGHT BUT THE BEST CHANCE WILL BE IN THE EAST.
COLD AIR ADVECTION WILL BE IN EARNEST FRIDAY NIGHT AND WILL LIKELY
BRING TEMPERATURES DOWN INTO THE 20S FOR LOWS. SOME RECOVERY WILL
TRY TO TAKE PLACE SATURDAY AS MID LEVEL TEMPERATURES BEGIN TO WARM
DURING THE DAY. EVENTUALLY BY SATURDAY NIGHT FLOW SHIFTS AWAY FROM
THE LAKE AND SHOULD BRING AN END TO THE LAKE EFFECT SNOW SHOWERS.
OTHERWISE...IT WILL BE FAIR OVER THE REST OF THE FORECAST AREA. FAIR
WEATHER AND TEMPERATURES BACK INTO THE UPPER 30S EXPECTED FOR SUNDAY.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A STRONG LOW PRESSURE SYSTEM WILL MOVE OUT OF THE PLAINS ACROSS
THE UPPER GREAT LAKES BRINGING SHOWERS AND INCREASING WINDS ON
MONDAY. VFR CONDITIONS EXPECTED THROUGH AT LEAST 12Z THEN LOWER
CEILINGS/VSBYS ARRIVING WITH A BAND OF RAIN ALONG A COLD FRONT
SWEEPING WEST TO EAST. RAIN WILL SPREAD INTO TOL/FDY BETWEEN 12-
14Z...CLE TOWARDS 16Z AND ERI BY 18Z. RAIN WILL GENERALLY LAST 2
HOURS OR LESS AT MOST SITES AND CONDITIONS WILL PRIMARILY BE MVFR
BUT BRIEF IFR IS POSSIBLE. A 50 KNOT LOW LEVEL JET NEAR 2500 FEET
WILL SPREAD INTO NORTHERN OHIO BETWEEN 08-15Z. INCLUDED THE WIND
SHEER WHERE SURFACE WINDS WERE LOW ENOUGH TO WARRANT IT...THEN
REMOVED THE MENTION AS SURFACE WINDS BECOME GUSTY AHEAD OF THE
FRONT. WINDS WILL SHIFT TO SOUTHWEST AND INCREASE BEHIND THE FRONT
DURING THE AFTERNOON. GUSTS OF 25 TO 30 KNOTS WILL BE COMMON WITH
LOCALLY STRONGER GUSTS IN NW OHIO.
OUTLOOK...NON VFR LINGERING INTO TUESDAY ACROSS NORTHEAST OH AND
NORTHWEST PA. NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA.
&&
.MARINE...
WINDS WILL INCREASE DURING THE DAY TODAY ON THE LAKE BUT
NOT EXPECTING THEM TO GO ABOVE GALES. WINDS WILL REMAIN MOSTLY
SOUTHERLY TODAY AND KEEP THE STRONGEST WINDS AND HIGHEST WAVES
OUTSIDE THE 5 NM NEARSHORE WATERS. ONCE WINDS BECOME MORE
WESTERLY...EXPECTING SMALL CRAFT CONDITIONS TO DEVELOP AROUND 5 PM
THIS AFTERNOON AND LAST UNTIL AROUND 4 PM TOMORROW AFTERNOON. SO
WILL GO AHEAD AND HOIST THE SMALL CRAFT FOR THIS TIME PERIOD.
OTHERWISE...WINDS DIMINISH FAIRLY QUICKLY TOMORROW EVENING AND
REMAIN FAIRLY LIGHT THROUGH THURSDAY MORNING. THEN...AS A COLD
FRONT MOVES EAST...WINDS WILL INCREASE AGAIN THURSDAY THROUGH
FRIDAY AND POSSIBLY CAUSE SMALL CRAFT ADVISORIES TO BE ISSUED ONCE
AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...KEC
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
1159 PM EST SUN DEC 13 2015
.SYNOPSIS...
A COLD FRONT NEAR THE MISSISSIPPI RIVER WILL CROSS THE
REGION ON MONDAY AS STRONG LOW PRESSURE MOVES ACROSS THE CENTRAL
GREAT LAKES. HIGH PRESSURE WILL BUILD OVER THE AREA FROM THE SOUTH
TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT IS EXPECTED TO CROSS THE
REGION ON THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
THE CLOUDS ARE HELPING TO KEEP THE TEMPS FROM DROPPING TOO MUCH.
STILL SOME PLACES HAVE ALREADY GOTTEN WITHING A DEGREE OR TWO OF
THE FORECAST LOW. WILL INCH THESE SPOTS DOWN ANOTHER DEGREE OR SO
TO ADD MORE OF A BUFFER.
A SPRINKLE COULD CLIP THE NW COUNTIES BUT THE HRRR AND RAP ARE
KEEPING MEASURABLE PRECIP OUT OF THE CWA THRU 12Z. BORDERING POPS
ARE SO HIGH...DON`T HAVE MUCH TO WORK WITH SO WILL RELUCTANTLY LEAVE
POP AS IS. AS THE LOW LEVEL JET INCREASES...WINDS WILL START TO PICK
UP TOWARD THE END OF THE NIGHT AND MAY BE GUSTING 20 TO 25 MPH IN
PARTS OF THE WEST AND ALONG THE LAKESHORE BY DAYBREAK.
&&
.SHORT TERM /6 AM MONDAY MORNING THROUGH WEDNESDAY NIGHT/...
THE MODELS REMAIN IN PRETTY GOOD AGREEMENT THROUGH THE PERIOD AS
FAR AS THE MAIN SYNOPTIC FEATURES ARE CONCERNED. RAIN IS EXPECTED
TO RAPIDLY SPREAD ACROSS THE FORECAST AREA TOMORROW MORNING AHEAD
OF THE FRONT. THE FRONT WILL BE EAST OF THE AREA BY MID AFTERNOON.
A DRY SLOT BEHIND WILL SWING INTO THE AREA FROM THE SOUTHWEST
DURING THE AFTERNOON SO THERE MAY BE A DRY PERIOD FOR A FEW HOURS.
WRAP AROUND MOISTURE WILL INCREASE LATER IN THE DAY AND SOME MORE
LIGHT PRECIP IS POSSIBLE DURING THE EVENING BEFORE THE RAIN ENDS
ALTOGETHER OVERNIGHT. HIGH PRESSURE WILL RETURN FOR TUESDAY AND
TUESDAY NIGHT. IT WILL BE TOUGH TO SCOUR OUT THE LOW LEVEL
MOISTURE BUT AT LEAST SOME PARTIAL SUNSHINE IS LIKELY ALL AREAS.
HAVE CONTINUED THE TREND OF SLOWING DOWN THE NEXT SYSTEM AS WELL.
PRECIP CHANCES SHOULD HOLD OFF TILL LATE WEDNESDAY IN THE WEST AND
WEDNESDAY NIGHT ELSEWHERE. MOISTURE LOOKS SOMEWHAT LIMITED SO NO
MORE THAN CHANCE POPS NEEDED. THE SURFACE COLD FRONT RESPONSIBLE
FOR THE PRECIP WILL OVER THE AREA AT 12Z THURSDAY. UNBELIEVABLY
THERE WILL BE NO PRECIP TYPE CONCERNS WITH ALL RAIN EXPECTED.
HAVE USED A BLEND OF GUIDANCE TEMPS DURING THE PERIOD.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
LITTLE CHANGE IN THE EXTENDED FORECAST. NEXT STRONG COLD FRONT
MOVES ACROSS THE FORECAST AREA THURSDAY MORNING...USHERING MORE
SEASONAL CONDITIONS. MODELS ARE SIMILAR BUT GFS CONTINUES TO BE A
LITTLE FASTER THAN THE ECMWF. PROBABLY A BREAK IN THE PRECIP
THURSDAY AFTERNOON AND EVENING. COULD SEE A LITTLE LAKE EFFECT IN
THE EAST FRIDAY AS THE 850MB TEMPS DIP TO -10C. BEST CHANCE FOR
LAKE ENHANCED SNOW SHOWERS FRIDAY EVENING INTO THE OVERNIGHT WITH
SECONDARY SHOT OF COLD AIR. BY 12Z SATURDAY THE 850MB TEMPS
PLUNGE TO -12C TO -14C. SO FAR OUT WILL JUST GO WITH CHANCE POPS
HOWEVER.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A STRONG LOW PRESSURE SYSTEM WILL MOVE OUT OF THE PLAINS ACROSS
THE UPPER GREAT LAKES BRINGING SHOWERS AND INCREASING WINDS ON
MONDAY. VFR CONDITIONS EXPECTED THROUGH AT LEAST 12Z THEN LOWER
CEILINGS/VISBYS ARRIVING WITH A BAND OF RAIN ALONG A COLD FRONT
SWEEPING WEST TO EAST. RAIN WILL SPREAD INTO TOL/FDY BETWEEN 12-
14Z...CLE TOWARDS 16Z AND ERI BY 18Z. RAIN WILL GENERALLY LAST 2
HOURS OR LESS AT MOST SITES AND CONDITIONS WILL PRIMARILY BE MVFR
BUT BRIEF IFR IS POSSIBLE. A 50 KNOT LOW LEVEL JET NEAR 2500 FEET
WILL SPREAD INTO NORTHERN OHIO BETWEEN 08-15Z. INCLUDED THE WIND
SHEER WHERE SURFACE WINDS WERE LOW ENOUGH TO WARRANT IT...THEN
REMOVED THE MENTION AS SURFACE WINDS BECOME GUSTY AHEAD OF THE
FRONT. WINDS WILL SHIFT TO SOUTHWEST AND INCREASE BEHIND THE FRONT
DURING THE AFTERNOON. GUSTS OF 25 TO 30 KNOTS WILL BE COMMON WITH
LOCALLY STRONGER GUSTS IN NW OHIO.
OUTLOOK...NON VFR LINGERING INTO TUESDAY ACROSS NORTHEAST OH AND
NORTHWEST PA. NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA.
&&
.MARINE...
SOUTH FLOW OVER THE LAKE WILL INCREASE OVERNIGHT AHEAD OF AN
APPROACHING COLD FRONT...BUT SHOULD REMAIN BELOW SMALL CRAFT
ADVISORY CRITERIA. A SMALL CRAFT ADVISORY WILL BE NEEDED MONDAY AS A
STRONG COLD PUSHES ACROSS THE LAKE. THERE STILL IS A SMALL CHANCE
OF A PERIOD OF SUSTAINED GALE FORCE WINDS BUT NOT ENOUGH TO RAISE A
GALE WATCH. WINDS DIMINISH FROM THE WEST TUESDAY AFTERNOON AS HIGH
PRESSURE MOVES ACROSS THE LOWER LAKES. WINDS BACK TO THE SOUTH
WEDNESDAY AHEAD OF NEXT SYSTEM THAT WILL MOVE ACROSS THE LAKE ON
THURSDAY.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...KUBINA
NEAR TERM...ADAMS/KUBINA
SHORT TERM...KUBINA
LONG TERM...DJB
AVIATION...KEC
MARINE...DJB
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
250 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION ON MONDAY.
TEMPERATURES WILL BE WARM AGAIN FOR MONDAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. THIS WILL MARK THE BEGINNING OF A RETURN TO MORE
SEASONAL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
LOWER STRATUS AND PATCHY FOG BEGINNING TO MOVE INTO MY FAR EASTERN
CWA ON A LIGHT EAST FLOW AND DEWPOINTS IN THE LOWER TO MID 50S. A
MID DECK CONTINUES TO OVERSPREAD THE REGION AHEAD OF APPROACHING
FRONT. THIS MAY LIMIT ANY WIDESPREAD LOWERING OF THE FOG BUT WILL
MONITOR FOR POTENTIAL ADVSYS.
WILL HOLD ONTO THE MENTION OF PATCHY LIGHT DRIZZLE AND SOME AREAS
OF 1SM FOG AFTER 06Z. HOWEVER...ALTHOUGH THE LARGER GRID SPATIAL
AND TEMPORAL MODELS GENERATE SOME VERY LIGHT QPF TWD
DAYBREAK...THE LATEST 02Z HRRR IS VOID OF ANY QPF THROUGH ALL OF
MONDAY MORNING.
TEMPS AND HUMIDITY OVERNIGHT WILL BE VERY HIGH FOR THIS TIME OF
YEAR /ESPECIALLY CONSIDERING THAT WE HAVE (OR RECENTLY HAD) NO
RAIN FALLING.
LOTS OF MIN TEMPS WILL COME IN ABOVE RECORDS EARLY MONDAY...
AS TEMPS STAY MAINLY IN THE 50S. SOME COOLER VALLEYS IN CENTRAL
PA COULD SEE TEMPS DIP INTO THE UPPER 40S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
LOW CLOUDS OVER THE NE WILL PROBABLY KEEP THE TEMPS FROM CLIMBING
TOO QUICKLY THERE ON MON...BUT THE GOOD SOUTH FLOW AND TIGHTENING
PRES GRADIENT WILL LIKELY MIX THEM OUT BY AFTN. CFRONT WILL BE
ENCROACHING BY MID AFTN...AND A FEW SHRA ARE POSS OVER THE WRN
MTNS BEFORE NOON. WILL KEEP THE HIGHEST POPS BETWEEN 18Z-
00Z...STEADILY MOVING THEM W-E. TEMPS AND DEWPOINTS WILL BE CRAZY
HIGH AGAIN MON - ESP IF IT CAN CLEAR UP A LITTLE BEFORE
FROPA/PRE-FRONTAL-TROUGH SHOWERS. A STRAY RUMBLE OF THUNDER IS
POSS IN THE SE...BUT THE COOLER START TO THE DAY IN THE NE SHOULD
PRECLUDE THEM FROM HEARING THUNDER. WINDS GET GUSTY BEHIND THE
FRONT AND SOME SHOWERS ARE EXPECTED IN THE W MON NIGHT...AS TEMPS
FALL...BUT NOT NEARLY TO NORMAL MINS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
AS LOW PRESSURE AREA SLIDES EAST THROUGH NEW ENGLAND ON TUESDAY...
FLOW AROUND PERIPHERY OF LOW WILL BRING BREEZY WINDS ON TUE...WITH
COOLER YET STILL QUITE MILD TEMPS IN THE 40S AND 50S.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /07Z MONDAY THROUGH FRIDAY/...
A SOUTHERLY BREEZE HAS KEPT ANY FOG PROBLEMS FROM KBFD SOUTH THRU
THE WESTERN AND CENTRAL TAF SITES AT BAY. ELSEWHERE...NEARLY CALM
WINDS SHOULD PROMOTE AT LEAST MVFR VSBYS...WITH PERIODS OF IFR/LIFR
CONDS FROM KIPT SOUTHWARD THRU KMDT/KLNS OVERNIGHT.
MDL SOUNDINGS INDICATE LOW CIGS/FOG COULD POTENTIALLY LINGER MUCH
OF MONDAY ARND KMDT/KLNS. ELSEWHERE...AN INCREASINGLY MOIST
SOUTHERLY FLOW IN ADVANCE OF AN APPROACHING COLD FRONT WILL LIKELY
CAUSE FALLING CIGS ACROSS THE CENTRAL MTNS MON AFTN/EVENING WITH
IFR CIGS LIKELY FROM KBFD SOUTH THRU KUNV/KAOO. THE FRONT WILL
SWEEP EASTWARD ACROSS THE REGION MON EVENING...ACCOMPANIED BY A
PERIOD OF SHOWERS AND PERHAPS EVEN A TSRA IN SPOTS. A DRIER WSW
FLOW BEHIND THE FRONT SHOULD BRING IMPROVING FLYING CONDS LATE MON
NIGHT...ESP EAST /DOWNWIND/ OF THE APPALACHIAN MTNS.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
UNUSUALLY WARM DECEMBER TEMPERATURES CONTINUE FOR THE NEXT
SEVERAL DAYS...WITH THE POTENTIAL FOR SOME RECORDS TO BE BROKEN
THROUGH MONDAY. SUNDAY SHOULD BE THE WARMEST DAY OF THE BUNCH.
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 67/1979 *64/2015* 64/1927 42/27
KIPT 59/1911 *62/2015* 65/1901 39/25
KAOO *68/2015* *66/2015* 59/2006 38/24
KBFD *59/2015* *61/2015* 54/2001 33/19
*STATE COLLEGE 63/1979 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
MAX-MINIMUM TEMPERATURES OF RECORD (AKA WARMEST LOWS)...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH
---------------------------------------------------------------------
KMDT 51/1911 45/1991 53/1901
KIPT 54/1911 47/1991 48/1927
KAOO *45/2015* 45/1991 44/2001
KBFD *45/2015* 39/1964 45/1991 36/2006
*STATE COLLEGE 44/1927 47/2001 41/2006
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT/RXR
NEAR TERM...TYBURSKI
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1243 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION ON MONDAY.
TEMPERATURES WILL BE WARM AGAIN FOR MONDAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. THIS WILL MARK THE BEGINNING OF A RETURN TO MORE
SEASONAL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
LOWER STRATUS AND PATCHY FOG BEGINNING TO MOVE INTO MY FAR EASTERN
CWA ON A LIGHT EAST FLOW AND DEWPOINTS IN THE LOWER TO MID 50S. A
MID DECK CONTINUES TO OVERSPREAD THE REGION AHEAD OF APPROACHING
FRONT. THIS MAY LIMIT ANY WIDESPREAD LOWERING OF THE FOG BUT WILL
MONITOR FOR POTENTIAL ADVSYS.
WILL HOLD ONTO THE MENTION OF PATCHY LIGHT DRIZZLE AND SOME AREAS
OF 1SM FOG AFTER 06Z. HOWEVER...ALTHOUGH THE LARGER GRID SPATIAL
AND TEMPORAL MODELS GENERATE SOME VERY LIGHT QPF TWD
DAYBREAK...THE LATEST 02Z HRRR IS VOID OF ANY QPF THROUGH ALL OF
MONDAY MORNING.
TEMPS AND HUMIDITY OVERNIGHT WILL BE VERY HIGH FOR THIS TIME OF
YEAR /ESPECIALLY CONSIDERING THAT WE HAVE (OR RECENTLY HAD) NO
RAIN FALLING.
LOTS OF MIN TEMPS WILL COME IN ABOVE RECORDS EARLY MONDAY...
AS TEMPS STAY MAINLY IN THE 50S. SOME COOLER VALLEYS IN CENTRAL
PA COULD SEE TEMPS DIP INTO THE UPPER 40S.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
LOW CLOUDS OVER THE NE WILL PROBABLY KEEP THE TEMPS FROM CLIMBING
TOO QUICKLY THERE ON MON...BUT THE GOOD SOUTH FLOW AND TIGHTENING
PRES GRADIENT WILL LIKELY MIX THEM OUT BY AFTN. CFRONT WILL BE
ENCROACHING BY MID AFTN...AND A FEW SHRA ARE POSS OVER THE WRN
MTNS BEFORE NOON. WILL KEEP THE HIGHEST POPS BETWEEN 18Z-
00Z...STEADILY MOVING THEM W-E. TEMPS AND DEWPOINTS WILL BE CRAZY
HIGH AGAIN MON - ESP IF IT CAN CLEAR UP A LITTLE BEFORE
FROPA/PRE-FRONTAL-TROUGH SHOWERS. A STRAY RUMBLE OF THUNDER IS
POSS IN THE SE...BUT THE COOLER START TO THE DAY IN THE NE SHOULD
PRECLUDE THEM FROM HEARING THUNDER. WINDS GET GUSTY BEHIND THE
FRONT AND SOME SHOWERS ARE EXPECTED IN THE W MON NIGHT...AS TEMPS
FALL...BUT NOT NEARLY TO NORMAL MINS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
AS LOW PRESSURE AREA SLIDES EAST THROUGH NEW ENGLAND ON TUESDAY...
FLOW AROUND PERIPHERY OF LOW WILL BRING BREEZY WINDS ON TUE...WITH
COOLER YET STILL QUITE MILD TEMPS IN THE 40S AND 50S.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE ALONG THE EAST COAST SHOULD ENSURE DRY WEATHER
ACROSS CENTRAL PA OVERNIGHT. MAIN AVIATION CONCERN WILL BE THE
POTENTIAL OF LOW CIGS/FOG DEVELOPING LATE TONIGHT ACROSS THE
EASTERN HALF OF THE STATE. A SOUTHERLY BREEZE SHOULD PRECLUDE FOG
PROBLEMS FROM KBFD SOUTH THRU KJST/KAOO. ELSEWHERE...NEARLY CALM
WINDS SHOULD PROMOTE AT LEAST MVFR VSBYS...WITH IFR/LIFR CONDS
QUITE POSSIBLE FROM KIPT SOUTHWARD THRU KMDT/KLNS LATE TONIGHT.
MDL SOUNDINGS INDICATE LOW CIGS/FOG COULD POTENTIALLY LINGER MUCH
OF MONDAY ARND KMDT/KLNS. ELSEWHERE...AN INCREASINGLY MOIST
SOUTHERLY FLOW IN ADVANCE OF AN APPROACHING COLD FRONT WILL LIKELY
CAUSE FALLING CIGS ACROSS THE CENTRAL MTNS MON AFTN/EVENING WITH
IFR CIGS LIKELY FROM KBFD SOUTH THRU KUNV/KAOO. THE FRONT WILL
SWEEP EASTWARD ACROSS THE REGION MON EVENING...ACCOMPANIED BY A
PERIOD OF SHOWERS AND PERHAPS EVEN A TSRA IN SPOTS. A DRIER WSW
FLOW BEHIND THE FRONT SHOULD BRING IMPROVING FLYING CONDS LATE MON
NIGHT...ESP EAST /DOWNWIND/ OF THE APPALACHIAN MTNS.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
UNUSUALLY WARM DECEMBER TEMPERATURES CONTINUE FOR THE NEXT
SEVERAL DAYS...WITH THE POTENTIAL FOR SOME RECORDS TO BE BROKEN
THROUGH MONDAY. SUNDAY SHOULD BE THE WARMEST DAY OF THE BUNCH.
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 67/1979 *64/2015* 64/1927 42/27
KIPT 59/1911 *62/2015* 65/1901 39/25
KAOO *68/2015* *66/2015* 59/2006 38/24
KBFD *59/2015* *61/2015* 54/2001 33/19
*STATE COLLEGE 63/1979 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
MAX-MINIMUM TEMPERATURES OF RECORD (AKA WARMEST LOWS)...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH
---------------------------------------------------------------------
KMDT 51/1911 45/1991 53/1901
KIPT 54/1911 47/1991 48/1927
KAOO *45/2015* 45/1991 44/2001
KBFD *45/2015* 39/1964 45/1991 36/2006
*STATE COLLEGE 44/1927 47/2001 41/2006
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT/RXR
NEAR TERM...TYBURSKI
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1127 PM EST SUN DEC 13 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION ON MONDAY.
TEMPERATURES WILL BE WARM AGAIN FOR MONDAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. THIS WILL MARK THE BEGINNING OF A RETURN TO MORE
SEASONAL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM MONDAY MORNING/...
PLENTY OF HIGH CLOUDS COVERED THE STATE LATE THIS EVENING WITH
JUST A SCATTERING OF MID CLOUDS. A SHIELD OF THICKER MID LEVEL
CLOUDS OVER SWRN PENN WILL ADVANCE TO THE ENE ACROSS MUCH OF THE
FCST AREA OVER THE NEXT SEVERAL HOURS. THIS WILL KEEP TEMPS
UNSEASONABLY MILD.
LOWER STRATUS MAY ADVECT WWD/DEVELOP OVER THE WESTERN POCONOS AND
PORTIONS OF THE SUSQ VALLEY VERY LATE TONIGHT...THANKS TO A
GENERALLY WEAK LLVL EAST TO SERLY FLOW OFF THE ATLANTIC. WILL HOLD
ONTO THE MENTION OF PATCHY LIGHT DRIZZLE AND SOME AREAS OF 1SM
FOG AFTER 06Z. HOWEVER...ALTHOUGH THE LARGER GRID SPATIAL AND
TEMPORAL MODELS GENERATE SOME VERY LIGHT QPF TWD DAYBREAK...THE
LATEST 02Z HRRR IS VOID OF ANY QPF THROUGH ALL OF MONDAY MORNING.
TEMPS AND HUMIDITY OVERNIGHT WILL BE VERY HIGH FOR THIS TIME OF
YEAR /ESPECIALLY CONSIDERING THAT WE HAVE (OR RECENTLY HAD) NO
RAIN FALLING.
LOTS OF MIN TEMPS WILL COME IN ABOVE RECORDS EARLY MONDAY...
AS TEMPS STAY MAINLY IN THE 50S. SOME COOLER VALLEYS IN CENTRAL
PA COULD SEE TEMPS DIP INTO THE UPPER 40S.
&&
.SHORT TERM /8 AM MONDAY MORNING THROUGH MONDAY NIGHT/...
LOW CLOUDS OVER THE NE WILL PROBABLY KEEP THE TEMPS FROM CLIMBING
TOO QUICKLY THERE ON MON...BUT THE GOOD SOUTH FLOW AND TIGHTENING
PRES GRADIENT WILL LIKELY MIX THEM OUT BY AFTN. CFRONT WILL BE
ENCROACHING BY MID AFTN...AND A FEW SHRA ARE POSS OVER THE WRN
MTNS BEFORE NOON. WILL KEEP THE HIGHEST POPS BETWEEN 18Z-
00Z...STEADILY MOVING THEM W-E. TEMPS AND DEWPOINTS WILL BE CRAZY
HIGH AGAIN MON - ESP IF IT CAN CLEAR UP A LITTLE BEFORE
FROPA/PRE-FRONTAL-TROUGH SHOWERS. A STRAY RUMBLE OF THUNDER IS
POSS IN THE SE...BUT THE COOLER START TO THE DAY IN THE NE SHOULD
PRECLUDE THEM FROM HEARING THUNDER. WINDS GET GUSTY BEHIND THE
FRONT AND SOME SHOWERS ARE EXPECTED IN THE W MON NIGHT...AS TEMPS
FALL...BUT NOT NEARLY TO NORMAL MINS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
AS LOW PRESSURE AREA SLIDES EAST THROUGH NEW ENGLAND ON TUESDAY...
FLOW AROUND PERIPHERY OF LOW WILL BRING BREEZY WINDS ON TUE...WITH
COOLER YET STILL QUITE MILD TEMPS IN THE 40S AND 50S.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
HIGH PRESSURE ALONG THE EAST COAST SHOULD ENSURE DRY WEATHER
ACROSS CENTRAL PA OVERNIGHT. MAIN AVIATION CONCERN WILL BE THE
POTENTIAL OF LOW CIGS/FOG DEVELOPING LATE TONIGHT ACROSS THE
EASTERN HALF OF THE STATE. A SOUTHERLY BREEZE SHOULD PRECLUDE FOG
PROBLEMS FROM KBFD SOUTH THRU KJST/KAOO. ELSEWHERE...NEARLY CALM
WINDS SHOULD PROMOTE AT LEAST MVFR VSBYS...WITH IFR/LIFR CONDS
QUITE POSSIBLE FROM KIPT SOUTHWARD THRU KMDT/KLNS LATE TONIGHT.
MDL SOUNDINGS INDICATE LOW CIGS/FOG COULD POTENTIALLY LINGER MUCH
OF MONDAY ARND KMDT/KLNS. ELSEWHERE...AN INCREASINGLY MOIST
SOUTHERLY FLOW IN ADVANCE OF AN APPROACHING COLD FRONT WILL LIKELY
CAUSE FALLING CIGS ACROSS THE CENTRAL MTNS MON AFTN/EVENING WITH
IFR CIGS LIKELY FROM KBFD SOUTH THRU KUNV/KAOO. THE FRONT WILL
SWEEP EASTWARD ACROSS THE REGION MON EVENING...ACCOMPANIED BY A
PERIOD OF SHOWERS AND PERHAPS EVEN A TSRA IN SPOTS. A DRIER WSW
FLOW BEHIND THE FRONT SHOULD BRING IMPROVING FLYING CONDS LATE MON
NIGHT...ESP EAST /DOWNWIND/ OF THE APPALACHIAN MTNS.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
UNUSUALLY WARM DECEMBER TEMPERATURES CONTINUE FOR THE NEXT
SEVERAL DAYS...WITH THE POTENTIAL FOR SOME RECORDS TO BE BROKEN
THROUGH MONDAY. SUNDAY SHOULD BE THE WARMEST DAY OF THE BUNCH.
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 67/1979 *64/2015* 64/1927 42/27
KIPT 59/1911 *62/2015* 65/1901 39/25
KAOO *68/2015* *66/2015* 59/2006 38/24
KBFD *59/2015* *61/2015* 54/2001 33/19
*STATE COLLEGE 63/1979 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
MAX-MINIMUM TEMPERATURES OF RECORD (AKA WARMEST LOWS)...
---------------------------------------------------------------------
LOCATION FRI/11TH SAT/12TH SUN/13TH MON/14TH TUE/15TH
---------------------------------------------------------------------
KMDT 51/1911 45/1991 53/1901
KIPT 54/1911 47/1991 48/1927
KAOO *45/2015* 45/1991 44/2001
KBFD *45/2015* 39/1964 45/1991 36/2006
*STATE COLLEGE 44/1927 47/2001 41/2006
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT/RXR
NEAR TERM...DANGELO/LAMBERT
SHORT TERM...DANGELO
LONG TERM...RXR
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1130 PM EST SUN DEC 13 2015
.SYNOPSIS...
HIGH PRESSURE OFF THE SOUTHEAST COAST WILL SLOWLY WEAKEN AND PUSH
OFFSHORE OVERNIGHT ALLOWING A RETURN SOUTHERLY FLOW OF LOW LEVEL
MOISTURE TO TAKE PLACE BY EARLY MONDAY. A COLD FRONT WILL APPROACH
FROM THE WEST MONDAY BEFORE SLIDING THROUGH THE AREA MONDAY NIGHT.
WEAK HIGH PRESSURE FOLLOWS THE FRONT BRINGING DRIER WEATHER AND
CONTINUED WARM TEMPERATURES INTO MID WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 815 PM EST SUNDAY...
WARMTH CONTINUES TO ROLL ON IN MID DECEMBER WITH ADDED RECORDS
ESTABLISHED THIS AFTERNOON PER THE CLIMATE SECTION BELOW WITH
ANOTHER MILD OVERNIGHT TO FOLLOW. LATEST EVENING SOUNDINGS SHOW
CONTINUED VERY DRY AIR ALOFT THIS EVENING AHEAD OF THE STRONG
UPPER TROUGH AND ASSOCIATED SURFACE COLD FRONT JUST WEST OF THE
MISSISSIPPI RIVER. HOWEVER SEEING PLENTY OF MID/HIGH CLOUDS SPILL
EAST FROM THE CONVECTION TO THE WEST AND THIS TREND LOOKS TO
PREVAIL OVERNIGHT GIVEN THE STRONG WESTERLY FLOW ALOFT. APPEARS
THIS CANOPY LIKELY TO KEEP THE LID ON WIDESPREAD FOG GIVEN LIMITED
RADIATIVE COOLING AND SUPPORTED BY UNFAVORABLE FORECAST FOG
STABILITY VALUES OFF SOUNDINGS TOWARD DAYBREAK MONDAY. LOOKS LIKE
BEST CHANCE AT FOG WILL BE OVER THE SOUTH AND EAST WHERE CLOUDS
MAY THIN MORE SO KEEPING BETTER COVERAGE THERE.
OTRW EXPECT LOW LEVEL MOISTURE TO GRADUALLY INCREASE OVER THE SW
ONCE THE FLOW TURNS A LITTLE MORE SE LATER ALLOWING SOME PATCHY
LIGHT SHOWERS TO DEVELOP WITHIN A WEAK ISENTROPIC/UPSLOPE REGIME.
LATEST HRRR HOLDS MOST COVERAGE OFF UNTIL AFTER MIDNIGHT AND ONLY
HAS SPOTTY SHOWERS DEVELOPING AT BEST. THUS DELAYING ONSET A BIT
PER DRYNESS AND TRIMMING BACK ON HIGH POPS UNTIL EARLY MONDAY.
LITTLE CHANGE AS WELL TO THE GOING WIND ADVISORY AS APPEARS THE
BEST LOW LEVEL JET ALSO WONT ARRIVE OUT WEST UNTIL AROUND DAYBREAK
WITH STRONGER WINDS POSSIBLE ON THE RIDGES INTO MIDDAY MONDAY.
TEMPS TO STAY MILD UNDER MAINLY CLOUDY SKIES OVERNIGHT WITH MOST
LINGERING IN THE 50S. HOWEVER DO EXPECT THE VALLEYS AND OUTLYING
EASTERN LOCATIONS TO DIP INTO THE 40S BEFORE LIKELY RISING LATE AS
CLOUDS THICKEN MORE AND MIXING PICKS UP.
PREVIOUS DISCUSSION AS OF 345 PM EST SUNDAY...
MAINTAINING THE PATTERN OF BROAD UPPER LEVEL RIDGING ACROSS THE
EASTERN HALF OF THE NATION THIS AFTERNOON...WHILE A DEEP UPPER
LEVEL LOW TRACKS NORTHEAST NEAR THE TEXAS PANHANDLE. IN THE LOW
LEVELS... HIGH PRESSURE IS CENTERED OFF THE CAROLINA COAST...WITH
SOUTH- WESTERLY WINDS ON THE BACKSIDE OF THE HIGH DRAWING WARM
GULF MOISTURE NORTHWARD ACROSS THE OUR AREA. DESPITE THICKENING
HIGH CLOUDS MOVING IN FROM THE WEST AS THE UPPER LOW APPROACHES...
TEMPERATURES ACROSS THE AREA WERE ABLE TO REBOUND AFTER
WIDESPREAD FOG LINGERED INTO LATE MORNING...REACHING INTO THE MID
60S TO THE LOW 70S.
WIND SPEEDS WILL INCREASE FROM WEST TO EAST HEADING INTO LATE
EVENING AS THE COLD FRONT ASSOCIATED WITH THE UPPER LEVEL LOW
APPROACHES FROM THE WEST...CAUSING THE PRESSURE GRADIENT ACROSS
THE REGION TO TIGHTEN. WEATHER FORECAST MODELS ARE IN DECENT
AGREEMENT THAT THE LOW LEVEL JET WILL RAMP UP TO AROUND 60 MPH
TOWARD DAWN MONDAY ACROSS THE MOUNTAINS. WITH SOUTHERLY WINDFLOW
IN PLACE...DOWNSLOPING ON THE WEST SIDE OF THE RIDGES FROM THE
HIGHLANDS OF NORTH CAROLINA INTO EXTREME SOUTHEAST WEST VIRGINIA
WILL BRING SOME OF THE STRONGER JET WINDS TO THE SURFACE. AS
SUCH...WILL CONTINUE WITH THE WIND ADVISORY IN EFFECT FROM MIDNIGHT
TONIGHT THROUGH 7 PM MONDAY.
BELIEVE THIS WILL BE ONE OF THOSE NIGHTS WHERE OVERNIGHT LOWS
OCCUR EARLIER IN THE NIGHT...AND THEN COOLING WILL SLOW/STOP AS THE
WINDSPEEDS INCREASE TOWARD DAWN. WHERE FOG WAS WIDESPREAD
THIS MORNING...BELIEVE IT WILL BE MORE SPOTTY IN NATURE LATE
TONIGHT DUE TO INCREASED CLOUDS...FOUND MORE SO ACROSS THE
SOUTHSIDE WHERE WINDSPEEDS WILL REMAIN LOWER. INSTEAD...EXPECT LOW
CLOUDS TO INCREASE ACROSS THE MOUNTAINS/FOOTHILLS AFTER
MIDNIGHT...WITH ONLY POCKETS OF LIGHT RAIN OR DRIZZLE POSSIBLE
ALONG THE RIDGES. OVERNIGHT LOWS WILL FALL INTO THE UPPER 40S TO
THE MID 50S.
SHOWER ACTIVITY WILL INCREASE AFTER SUNRISE AS THE COLD FRONT PASSES
EAST OF THE MISSISSIPPI RIVER TOWARD THE APPALACHIANS. EXPECT MAINLY
SHOWER ACTIVITY THROUGH LATE MORNING...WHEN THE MAIN UPPER LEVEL
SUPPORT WILL ARRIVE ALONG OUR WESTERN BORDER...TRIGGERING A SOLID
LINE OF RAIN SHOWERS. DO NOT SEE MUCH INSTABILITY TO SUPPORT THE
POTENTIAL FOR THUNDER WITH THIS LINE...ALTHOUGH IT CANNOT BE
ENTIRELY RULED OUT. HOWEVER...LOW LEVEL SHEAR/HELICITY WILL BE
STRONG ENOUGH THAT SOME OF THE STRONGER SHOWERS WILL STILL BE
CAPABLE OF PRODUCING LOCALLY STRONG WIND GUSTS. THE COLD FRONT WILL
FINALLY ENTER OUR SOUTHEAST WEST VIRGINIA/MOUNTAIN EMPIRE COUNTIES
DURING EARLY AFTERNOON...AND WILL EXIT OUR AREA TO THE EAST SHORTLY
BEFORE MIDNIGHT. FRONTAL PASSAGE WILL BRING WITH IT A WESTERLY WIND
SHIFT THAT WILL BRING ONLY SLIGHTLY COOLER AIR.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 236 PM EST SUNDAY...
NOT TOO MUCH CHANGE FROM PREVIOUS FORECAST THIS PERIOD. HAVE
INCREASED WIND GUSTS FOR LATE MONDAY NIGHT/EARLY TUESDAY MORNING AS
ANOTHER PIECE OF HIGHER WINDS AT 8H MOVING ACROSS THE AREA...WITH
6HR PRESSURE RISES OF 4-7MB. THINK AT THIS POINT THAT WIND ADVISORY
LEVELS WILL BE LIMITED TO A FEW HIGHER RIDGES LIKE MT ROGERS...SO
NOT GOING TO EXTEND THE WIND ADVISORY CURRENTLY IN EFFECT...WHICH IS
MAINLY FOR THE STRONG WINDS AHEAD OF THE FRONT.
WE SHOULD SEE THE FRONT CLEAR THE PIEDMONT BY MIDNIGHT....WITH
DRYING TAKING PLACE PRIOR TO THIS. THERE IS NO SUBSTANTIAL AIRMASS
CHANGE BEHIND IT...CONTINENTAL...SO LOWS TUESDAY MORNING WILL STILL
BE ABOVE NORMAL...FROM THE LOWER TO MID 40S MOUNTAINS...TO NEAR 50
EAST.
TUESDAY...SHORTWAVE RIDGE PUSHES ACROSS THE SOUTHEAST TO THE
MIDWEST. FAST FLOW ALOFT MAY BRING SOME CIRRUS TO OUR AREA...WITH
LINGERING STRATOCU IN THE WV MTNS. WINDS WILL BE GUSTY EARLY...THEN
WEAKENING BY DUSK. A MILD DAY WITH HIGHS FROM THE MID TO UPPER 50S
WEST...TO THE MID 60S EAST.
HIGH PRESSURE BUILDS OVERHEAD TUESDAY NIGH ALLOWING FOR FALLING
TEMPERATURES IN THE VALLEYS...WITH RETURN FLOW KICKING IN LATE OVER
THE WRN RIDGES. WITH MAINLY CLEAR SKIES TEMPS SHOULD FALL TO THE
LOWER TO MID 30S IN THE VALLEYS...WITH UPPER 30S/NEAR 40 ELSEWHERE.
WEDNESDAY...HIGH PRESSURE SHIFTS OFFSHORE WITH SW FLOW INCREASING
ALOFT. SHOULD SEE INCREASING CLOUDS LATE IN THE DAY...BUT ANY
SHOWERS WILL HOLD OFF UNTIL WEDNESDAY NIGHT...WITH BEST CONVERGENCE
OF MOISTURE SHIFTING FROM THE SOUTHERN APPALACHIANS AT MIDNIGHT TO
THE VIRGINIA PIEDMONT BY 12Z THU. BEFORE THE CLOUDS MOVE IN
WEDNESDAY WE SHOULD SEE TEMPS WARM INTO UPPER 50S TO MID 60S. WITH
THE HIGH OVER THE NORTHEAST TO MID ATLANTIC...THE SF FLOW WILL BE
MORE OUT OF THE SE WHICH MAY KEEP THINGS COOLER. POTENTIAL DOES
EXIST THAT IF THE FLOW CAN TURN AROUND MORE TO THE SOUTH OR
SOUTHWEST BEFORE THE CLOUDS ENTER THE PICTURE...TEMPS MAY RISE MORE
INTO THE MID 60S OUT EAST.
WEDNESDAY NIGHT LOOKS SOMEWHAT MILD WITH CLOUDS BUT RAIN SHOWERS
SHOULD LOWER READINGS TO THE DEWPOINTS...WITH MOST LOCATIONS HAVING
LOWS IN THE MID 40S.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 1230 PM EST SUNDAY...
THE LONG RANGE FEATURES THE FIRST BIG ARCTIC PUSH INTO THE REGION
FOR QUITE SOME TIME...ALTHOUGH THE COLD AIR WONT STICK AROUND LONG.
THE PERIOD STARTS WARM WITH +11C 850MB TEMPS AHEAD OF AN APPROACHING
COLD FRONT AND DIGGING TROUGH. EXPECT SHOWERS AHEAD OF THE FRONT
THURSDAY INTO FRIDAY. EXACTLY HOW MUCH RAIN WILL FALL ACROSS OUR
REGION WILL DEPEND ON HOW DEEP THE TROUGH TO OUR WEST DIGS...FOR
RIGHT NOW IT LOOKS LIKE AREAS ALONG AND EAST OF THE BLUE RIDGE WILL
SEE THE MOST RAIN. THE COLD FRONT WILL PUSH THROUGH THE AREA
SOMETIME FRIDAY MORNING PUSHING THE RAIN OUT WITH IT.
BEHIND THE COLD FRONT TEMPS WILL FALL QUICKLY. AS THE TROUGH SWINGS
THROUGH THE REGION 850MB TEMPS WILL DROP DOWN TO -10 TO -12C BY
SATURDAY MORNING. WITH SUFFICIENT LOW LEVEL MOISTURE...THERE IS A
GOOD CHANCE WE WILL SEE NORTHWEST FLOW SNOW SHOWERS ALONG THE
FAVORED WESTERN RIDGES FRIDAY NIGHT AND THROUGH THE DAY SATURDAY.
HIGH TEMPS SATURDAY WILL RUN 5-10 DEGREES BELOW NORMAL WITH MANY
MOUNTAIN LOCATIONS STRUGGLING TO REACH THE FREEZING MARK.
BY SUNDAY THE TROUGH MOVES OFF TO OUR EAST AND ALONG WITH IT THE
COLD AIR. STRONG HIGH PRESSURE BUILDS IN AND WILL MOVE JUST TO OUR
EAST SUNDAY NIGHT/MONDAY MORNING. THE W/SW FLOW WILL ONCE AGAIN PULL
WARM AIR INTO THE REGION AND WE RETURN TO ABOVE NORMAL TEMPS.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
AS OF 1115 PM EST SUNDAY...
VFR CONDITIONS WILL CONTINUE TO LINGER A FEW MORE HOURS INTO THE
OVERNIGHT UNDER HIGH/MID CLOUDS BEFORE PATCHY FOG STARTS TO
DEVELOP AND LOW LEVEL MOISTURE INCREASES. THIS AHEAD OF A COLD
FRONT THAT WILL APPROACH FROM THE WEST OVERNIGHT INTO
MONDAY...CAUSING THE PRESSURE GRADIENT TO TIGHTEN AND SOUTHERLY
WINDS TO INCREASE...ESPECIALLY ACROSS THE HIGHER WESTERN RIDGES.
THE LOW LEVEL JET WILL RAMP UP TO AROUND 50 KTS NEAR KBLF...AND
DOWNSLOPING IN THE NEARBY TERRAIN MAY RESULT IN OCCASIONAL 25 TO
35 KT GUSTS AT THE AIRPORT TOWARD DAWN. PILOTS SHOULD WATCH FOR
LOW LEVEL WINDS SHEAR LATE TONIGHT INTO MONDAY MORNING ESPECIALLY
OVER THE MOUNTAIN LOCATIONS WHERE SURFACE WINDS WILL BE LIGHTER
SUCH AS AT KLWB/KBCB.
EXPECT A RETURN OF MVFR/IFR CONDITIONS LATE TONIGHT AS STRATUS
DEVELOPS ACROSS MUCH OF THE AREA...STARTING PRIOR TO DAWN ON
MONDAY. THE TAF SITE WITH THE BEST CHANCE FOR IFR CONDITIONS IS
KDAN WITH LOW CLOUDS/FOG GIVEN LIGHT WINDS AND LOW LEVEL MOISTURE
MOVING UP FROM THE SOUTH. EXPANDING LOW LEVEL MOISTURE WILL LIFT
NORTHWARD FROM SOUTHWEST TO NORTHEAST LATER TONIGHT INTO MONDAY
MORNING. ALONG THE SOUTHERN BLUE RIDGE WILL HAVE THE GREATEST
OPPORTUNITY FOR SHOWERS AND LIGHT RAIN OVERNIGHT INTO EARLY
MONDAY.
AS THE COLD FRONT ENTERS EASTERN KENTUCKY AND TENNESSEE MONDAY
MORNING...LOW MVFR/IFR CONDITIONS WILL DEVELOP ACROSS ALL OF THE
REGION. LOW MVFR/IFR CONDITIONS WILL REMAIN ACROSS THE FORECAST AREA
THROUGH THE AFTERNOON AS RAIN SHOWERS PASS ACROSS AHEAD OF THE
APPROACHING COLD FRONT. THE COLD FRONT WILL MOVE EAST MONDAY INTO
MONDAY NIGHT...REACHING THE ATLANTIC COAST TUESDAY MORNING. BRIEF
BURSTS OF HEAVIER SHOWERS MAY RESULT IN MVFR TO OCNL IFR VSBYS
ESPECIALLY WHERE FOG MIXES IN THROUGH MONDAY. IN ADDITION... CAN
NOT RULE OUT GUSTY WINDS WITH THE STRONGER SHOWERS. STRONG WEST TO
NORTHWEST WINDS ARE POSSIBLE BEHIND THE COLD FRONT MONDAY AND
MONDAY NIGHT AS DRIER AIR SWINGS IN FROM THE WEST. THIS SHOULD
SHUT OFF MOST SHOWERS BY MIDNIGHT MONDAY NIGHT BUT STILL EXPECT
OVERALL MVFR CIGS DURING THE EVENING WITH IMPROVING CONDITIONS
OVERNIGHT.
MEDIUM CONFIDENCE ON CEILINGS...VISIBILITIES AND WINDS DURING THE
TAF PERIOD.
.EXTENDED AVIATION DISCUSSION...
WIDESPREAD VFR UNDER DIMINISHING WINDS WILL OCCUR UNDER WEAK HIGH
PRESSURE TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT WITH AN
ASSOCIATED AREA OF LOW PRESSURE LOOKS TO BRING MORE IN THE WAY OF
WIDESPREAD SUB- VFR IN RAIN AND LOWER CIGS LATE WEDNESDAY NIGHT
INTO THURSDAY EVENING. SHOULD EVOLVE INTO VFR DURING FRIDAY AS
DEEP MOISTURE EXITS AND AN UPSTREAM UPPER DISTURBANCE APPROACHES.
HOWEVER LINGERING UPSLOPE FLOW LIKELY TO KEEP MVFR CEILINGS IN
PLACE ACROSS THE SOUTHEAST WEST VA SITES FOR MUCH OF THE DAY.
&&
.CLIMATE...
AS OF 745 PM EST SUNDAY...
RECORD HIGH TEMPERATURES WERE SET TODAY (12/13) AT BOTH DANVILLE
VA AND BLUEFIELD WV. SEE THE LATEST WBCRERRNK FOR ADDED DETAILS.
RECORD HIGH TEMPERATURES FOR....
DEC 14
BLACKSBURG | 70 IN 1984
BLUEFIELD | 68 IN 1984
DANVILLE | 74 IN 1948
LYNCHBURG | 70 IN 1948
ROANOKE | 73 IN 1927
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 7 PM EST MONDAY FOR VAZ007-009-010-015.
NC...WIND ADVISORY UNTIL 7 PM EST MONDAY FOR NCZ001-018.
WV...WIND ADVISORY UNTIL 7 PM EST MONDAY FOR WVZ042.
&&
$$
SYNOPSIS...JH/NF
NEAR TERM...JH/NF
SHORT TERM...WP
LONG TERM...CF
AVIATION...JH/KK/NF
CLIMATE...CF/DS/JH/RAB/WP
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
945 AM EST MON DEC 14 2015
.DISCUSSION...
...NEAR RECORD WARMTH FOR TODAY...
MORNING RAOBS/USAF PROFILER DATA SHOWING A BRISK SRLY FLOW THRU THE
H100-H70 LYR AHEAD OF A COLD FRONT NOSING ITS WAY THRU THE DEEP
SOUTH. WINDS WILL GRADUALLY VEER TO THE SW THRU THE DAY AS THE FRONT
CONTINUES ITS SLOW ADVANCE...THOUGH A DEEP HI PRES RIDGE CENTERED SW
OF BERMUDA WILL FORCE THE FRONT TO STALL AS IT WORKS ITS WAY INTO
THE BIG BEND REGION. RAP ANALYSIS SHOWS MINIMAL MID LVL VORTICITY
AND UPR LVL DIVERGENCE AHEAD OF THE FRONT...H50 TEMPS BTWN -3/-4C
WITH MID LVL LAPSE RATES RUNNING BLO 5.0C/KM. MOISTURE IS SOMEWHAT
LIMITED WITH PWAT VALUES ARND 1.5" AT KTBW/KXMR...DECREASING TO
ARND 1.3" AT KMFL. RAP ANALYSIS CONFIRMS THIS WITH MEAN RH VALUES
AOB 70PCT THRU THE H100-H70 LYR ACRS CENTRAL/S FL.
THE DVLPG SW FLOW REGIME IS ONE OF THE WARMEST FOR EAST CENTRAL FL.
MAX TEMPS SUN AFTN WERE IN THE L80S AREAWIDE...AND WHILE INCREASING
UPR LVL CLOUDS AHEAD OF THE FRONT MAY IMPEDE SFC HEATING...NEAR
RECORD TEMPS ARE EXPECTED THIS AFTN WITH READINGS ARND 15F ABV AVG.
GIVEN THE DECREASING MOISTURE TO THE SOUTH...THE TEPID MID LVL
TEMPS...AND LIMITED DYNAMIC SUPPORT...WILL KEEP POPS AOB 20PCT.
&&
.AVIATION...THRU 15/12Z
SFC WNDS: THRU 14/22Z...S/SW 9-13KTS WITH OCNL G20KTS. BTWN 14/22Z-
15/02Z...BCMG S/SW 2-4KTS.
VSBY/WX/CIGS: THRU 15/06Z...PREVAILING VFR WITH CIGS BTWN FL040-
060...BRIEF ISOLD MVFR SHRAS S OF KISM-KDAB. AFT 15/06Z...N OF KISM-
KTIX MVFR CIGS BTWN FL010-020 LCL LIFR CIGS BLO FL006 WITH VSBYS BLO
1SM IN BR/FG. S OF KISM-KTIX CIGS AOA FL120 AREAS MVFR VSBYS IN
BR.
&&
.MARINE...
LATEST SFC/OCEAN OBS SHOW A SIGNIFICANT DECREASE IN WINDS ACRS THE
REGION OVER THE PAST 12HRS...EVEN AS RAOB/PROFILER DATA DISPLAY A
SOLID 20-25KTS OF SRLY FLOW THRU 10KFT. SEAS AT BUOY009 HAVE
SUBSIDED TO ARND 6FT...MAINLY IN AN ERLY SWELL. BUOY010 IS HOLDING
15-20KTS...BUT ALSO SHOWING A DIMINISHING SEA TREND OVER THE PAST
SVRL HRS.
GENTLE TO MODERATE WINDS EXPECTED TO VEER TO SW THRU THE AFTN AS THE
FRONTAL TROF BEGINS TO STALL OVER THE PANHANDLE. WHILE CONDITIONS
ARE EXPECTED TO IMPROVE...THE OPPOSING WRLY WIND/ERLY SWELL
COMPONENTS MAY GENERATE POCKETS OF ROUGH SEAS. WILL ALLOW THE SCA TO
EXPIRE AT 15Z BUT WILL MAINTAIN CAUTIONARY STATEMENTS FOR THE
GULFSTREAM WATERS.
&&
.CLIMATE...
NEAR RECORD/RECORD HIGHS POSSIBLE TODAY...
LOC DATE HI-MAX
DAB 14-DEC 85 1991...FORECAST 84
MCO 14-DEC 86 1972...FORECAST 85
MLB 14-DEC 85 1961...FORECAST 84
VRB 14-DEC 85 1991...FORECAST 84
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...CRISTALDI
AREA FORECAST DISCUSSION...CORRECTED
NWS TAMPA BAY RUSKIN FL
931 AM EST MON DEC 14 2015
.UPDATE (REST OF TODAY THROUGH TUESDAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AND ACTIVE UPPER LEVEL
PATTERN OVER THE CONUS. LOOKING OUT WEST WE FIND DEEP AND SHARP
TROUGHING PIVOTING EASTWARD FROM THE PACIFIC COAST INTO THE INTER-
MOUNTAIN WEST. NORTHERN STREAM FLOW THEN EXITS THIS TROUGH AND LIFTS
UP INTO SOUTHERN CANADA BEFORE TURNING EASTWARD INTO A MORE ZONAL
PATTERN ALL THE WAY TO NOVA SCOTIA. REMOVED FROM THE NORTHERN STREAM
FLOW WE FIND A POTENT UPPER LEVEL LOW QUICKLY PIVOTING TO THE
NORTHEAST FROM THE CENTRAL PLAINS TO THE GREAT LAKES REGION/UPPER
MIDWEST. A SURFACE REFLECTION LOW UNDERNEATH THIS SYSTEM IS LIFTING
THROUGH THE UPPER MIDWEST WITH A TRAILING COLD FRONT ALL THE WAY
SOUTH TO THE NORTHEAST GULF OF MEXICO. WV IMAGERY SHOWS A DEEP
SOUTHERLY MOISTURE PLUME SPREADING NORTHWARD AHEAD OF THIS FRONT AND
INTO THE PARENT SYSTEM. PLENTY OF INCLEMENT WEATHER ONGOING FROM THE
GREAT LAKES SOUTHWARD ALONG THE FRONT TO THE FLORIDA PANHANDLE.
A LITTLE CLOSER TO HOME...WE ARE STILL OUT AHEAD OF THIS COLD FRONT
WITHIN AN UNSEASONABLE WARM AND HUMID AIRMASS. THE STRONG UPPER
RIDGE THAT DOMINATED OUR WEATHER THIS PAST WEEKEND STILL HAS SOME
INFLUENCE ON THE REGION...ESPECIALLY THE CENTRAL AND SOUTHERN PARTS
OF THE PENINSULA FOR TODAY...HOWEVER A GLANCE AT THE 12Z KTBW
SOUNDING PROFILE SHOWS THAT THE DEPTH AND STRENGTH OF THE RIDGE AND
RESULTING OVERALL SUPPRESSION HAS DECREASED IN THE PAST 24 HOURS.
THE SUBSIDENCE INVERSION IS NOW MUCH HIGHER LOCATED AROUND 600MB
COMPARED TO BETWEEN 850-700MB SUNDAY MORNING. AS A RESULT...THE
COLUMN PW HAS ALSO COME UP SUBSTANTIALLY...FROM WELL UNDER 1"
SUNDAY MORNING TO AROUND 1.5" THIS MORNING.
AT THE SURFACE...MAIN RIDGE OF HIGH PRESSURE HAS SHIFTED OFF THE
CAROLINA COAST INTO THE WESTERN ATLANTIC...WITH AN EXTENSION OF THE
RIDGE OFF TO THE SOUTHWEST ACROSS THE CENTRAL/SOUTHERN FLORIDA
PENINSULA/SW GULF OF MEXICO. OUR LOW LEVEL FLOW HAS VEERED TO A MORE
SOUTHERLY DIRECTION BETWEEN THIS RIDGE AND THE SLOWLY APPROACHING
COLD FRONT...CURRENTLY LOCATED OVER THE FL PANHANDLE/NORTH-CENTRAL
GULF. THE SOUTHERLY FLOW AND ABUNDANT LOW LEVEL MOISTURE KEPT
TEMPERATURES EARLY THIS MORNING WELL ABOVE NORMAL...STARTING THE DAY
OUT WITH MOST LOCATIONS IN THE 70S! QUITE A BIT OF LOW STRATUS
DEVELOPMENT EARLY THIS MORNING WITH ALL THE AVAILABLE MOISTURE UNDER
THE UPPER RIDGE. WILL SEE MOSTLY CLOUDY SKIES WITH BREAKS OF SUN
GIVE WAY TO A MIX OF SUN AND CLOUDS THROUGH MIDDAY. REGIONAL RADARS
ARE QUIET AROUND THE PENINSULA...WITH THE NEAREST ORGANIZED
RAINFALL LOCATED ALONG THE FRONT OVER THE FL PANHANDLE.
REST OF TODAY...FORECAST AREA WILL REMAIN WITHIN THE WARM SECTOR
AHEAD OF THE FRONT THROUGHOUT THE DAY. EVEN WITH PLENTY OF CLOUDS
TODAY...LOOKING FOR ENOUGH SUNNY BREAKS TO RESULT IN ANOTHER WELL
ABOVE AVERAGE DAY IN TERMS OF TEMPERATURE AND HUMIDITY. NOT HARD
TO ACCOMPLISH THAT WHEN YOUR 8AM TEMPERATURES ARE ALREADY
SURPASSING YOUR NORMAL HIGHS FOR THE DATE. THE LOW LEVEL POTENTIAL
OF THE ATMOSPHERE IN TERMS OF TEMPERATURES IS VERY HIGH...WITH
850MB TEMPERATURES AROUND 16C (WELL OVER THE 90TH PERCENTILE FOR
MID- DECEMBER). IN FACT THE 12Z KTBW SOUNDING SHOWED A 16C
TEMPERATURE AS HIGH AS 825MB. ALONG THE SAME SUBJECT...TO SHOW
JUST HOW ABNORMAL THE WARMTH OF THE COLUMN IS OVER OUR HEADS...THE
12Z KTBW SOUNDING ALSO MEASURED A 700MB TEMPERATURE OF 9C (WELL
OVER THE 90TH PERCENTILE FOR MID-DECEMBER)...AND THE 500MB
TEMPERATURE WAS MEASURED AT -3.1C. THIS VALUE TIES THE SECOND
WARMEST EVER 500MB TEMP OBSERVED FOR KTBW IN DECEMBER. ONE OTHER
TIME...-2.1C WAS OBSERVED ON DECEMBER 7TH. VERY IMPRESSIVE VALUES
INDEED. GIVEN HOW WARM THE COLUMN IS...EVEN BRIEF PEAKS OF THE SUN
WILL QUICKLY BOOST OUR TEMPERATURES INTO THE LOW/MID 80S AWAY FROM
THE IMMEDIATE COAST. WIND HAVE ALREADY COME AROUND TO THE
SOUTH...AND SHOULD DEVELOP AN ONSHORE COMPONENT DURING THE
AFTERNOON. THIS ONSHORE COMPONENT OFF THE "RELATIVELY" COOLER SHELF
WATERS SHOULD HELP KEEP TEMPS AT THE BEACHES DOWN IN THE 70S.
DUE TO THE DEEPER MOISTURE IN PLACE...AN ISOLATED SHOWER OR TWO IS
POSSIBLE ACROSS MAINLY THE INTERIOR ZONES THIS AFTERNOON/EARLY
EVENING...BUT COVERAGE WILL BE SPARSE AT BEST AND BARELY WORTH
MENTION IN THE FORECAST. WE DO HAVE A BAND OF SHOWERS APPROACHING
THE NATURE COAST FROM THE WEST...BUT PROGRESS IS VERY SLOW AS THE
FRONTAL MOVEMENT SLOWS. ALSO...ALL THE SYNOPTIC FORCING FOR LIFT
ASSOCIATED WITH THE PARENT SYSTEM IS QUICKLY EXITING WELL NORTH OF
THE REGION AND WILL BE COMPLETELY GONE BY LATER TODAY. THIS LOSS OF
LARGE SCALE ASCENT...AND GRADUAL STRETCHING/SLOWING OF THE FRONT
AND LOSS OF LOW LEVEL FOCUS SHOULD RESULT IN LESS ORGANIZED AND
LESS COVERAGE OF SHOWERS AS THE FRONT MOVES EAST LATER TODAY. ONLY
HAVE A 20% POP OVER LEVY COUNTY LATE THIS AFTERNOON INTO THE
EVENING FOR THESE REASONS.
TONIGHT/TUESDAY...WEAK FRONTAL STRUCTURE LAYS OUT ACROSS THE FLORIDA
BIG BEND AND BECOMES QUASI-STATIONARY BY TUESDAY MORNING. THIS IS A
FAR SOUTH AS THE BOUNDARY WILL MAKE IT BEFORE RETREATING NORTHWARD
AS A WARM FRONT INTO AL/GA ON WEDNESDAY. NO RELIEF FROM THE WARMTH
AND HUMIDITY WITH THIS FRONT IS IN THE FORECAST. LOW TEMPERATURES
TONIGHT WILL AGAIN BOTTOM OUT ONLY IN THE MID/UPPER 60S FOR THE
COOLER SPOTS...WITH MANY LOCATIONS NEAR THE COAST HOLDING IN THE
LOWER 70S. AS WE HEAD DEEPER INTO THE OVERNIGHT AND THE FRONT
SETTLES INTO POSITION NEAR LEVY/CITRUS/HERNANDO/SUMTER
COUNTIES...SOME UPTICK IN SHOWER ACTIVITY IS SHOWN BY MANY OF THE
GUIDANCE MEMBERS. WOULD EXPECT TO KEEP AT LEAST CHANCE POPS FOR
SHOWERS AFTER MIDNIGHT ACROSS THESE NORTHERN ZONES...WITH ISOLATED
SHOWER CHANCES AS FAR SOUTH AS AROUND THE I-4 CORRIDOR BY DAWN.
LAST FEW RUNS OF THE SREF MEMBERS HAVE POINTED TO A HIGH POTENTIAL
FOR WIDESPREAD LOW STRATUS/AREAS OF FOG LATER TONIGHT INTO TUESDAY
MORNING. SIMILAR TO LAST NIGHT...LEANING TOWARD BETTER CHANCES FOR A
LOW IFR STRATUS EVENT...BUT LIKELY TO SEE SOME DENSE FOG IN A FEW
SPOTS...ESPECIALLY SOUTH OF ANY SHOWER ACTIVITY.
TUESDAY...WEAK STATIONARY FRONT REMAINS IN PLACE OVER THE NORTHERN
PENINSULA. MOISTURE PROFILES AND WEAK LOW LEVEL FOCUS ALONG THE
BOUNDARY SHOULD BE ENOUGH TO KEEP AT LEAST A CHANCE OF SHOWERS IN
THE FORECAST ALONG AND NORTH OF THE I-4 CORRIDOR. THE DRIER WEATHER
AND BETTER CHANCES FOR SUNNY BREAKS WILL CERTAINLY EXIST TO THE
SOUTH OF THE TAMPA BAY AREA TOMORROW...WHERE TEMPERATURES AGAIN
BOOST INTO THE 80S AWAY FROM THE BEACHES FOR THE AFTERNOON. WITH
MORE CLOUDS AND OCCASIONAL SHOWER POTENTIAL...WILL LIMIT TEMPS IN
THE MID/UPPER 70S NORTH OF I-4. WHILE MAINLY ANTICIPATING SCT
SHOWERS TOMORROW. GFS/NAM BOTH INDICATE SHOWALTER INDICES AROUND
ZERO OVER THE NATURE COAST TOMORROW...SO A FEW TICKS OF LIGHTNING
CAN NOT BE RULED OUT...AND WILL ADD ISOLATED STORMS TO THE GRIDS.
&&
.AVIATION...
QUITE A BIT OF LOWER STRATUS AND RESULTING IFR/MVFR CONDITIONS
ACROSS THE REGION THIS MORNING. THE STRATUS IS FAIRLY THIN...SO
SHOULD BEGIN TO SEE IMPROVEMENT AFTER 15-16Z...WITH GENERAL VFR
CONDITIONS OR HIGH END MVFR THROUGH THE AFTERNOON/EVENING.
POTENTIAL FOR ANOTHER WIDESPREAD LOWER STRATUS/FOG EVENT IS
INCREASING FOR THE SECOND HALF OF TONIGHT AND TUESDAY MORNING.
WILL CONTINUE TO MONITOR GUIDANCE TRENDS...BUT LIKELY AT LEAST
MVFR RESTRICTIONS WILL BE ADDED TO THE 18Z TAFS AFTER 06Z TUESDAY
MORNING.
&&
.MARINE...
A WEAK COLD FRONT WILL SLOWLY APPROACH THE REGION TODAY AND STALL
ACROSS THE NORTHEAST GULF OF MEXICO TONIGHT AND TUESDAY. WINDS
WILL GENERALLY REMAIN OUT OF THE SOUTH AHEAD OF THIS FRONT...BUT
MAY BRIEFLY SHIFT TO THE NORTHEAST OFF THE LEVY/CITRUS COUNTY
COASTS ON TUESDAY. THIS FRONT WILL THEN LIFT BACK NORTH ON
WEDNESDAY WITH A CONTINUATION OF SOUTHERLY FLOW ACROSS THE EASTERN
GULF. WINDS AND SEAS ARE FORECAST TO GENERALLY REMAIN BELOW
HEADLINE CRITERIA THROUGH MID-WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 80 69 80 67 / 10 20 30 10
FMY 83 69 84 69 / 10 10 20 10
GIF 83 67 82 68 / 10 10 20 10
SRQ 79 68 80 68 / 10 10 20 10
BKV 82 67 80 66 / 10 20 50 20
SPG 79 69 79 69 / 10 20 30 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE...MROCZKA
DECISION SUPPORT...CARLISLE
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
917 AM EST MON DEC 14 2015
.UPDATE (REST OF TODAY THROUGH TUESDAY)...
14Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AND ACTIVE UPPER LEVEL
PATTERN OVER THE CONUS. LOOKING OUT WEST WE FIND DEEP AND SHARP
TROUGHING PIVOTING EASTWARD FROM THE PACIFIC COAST INTO THE INTER-
MOUNTAIN WEST. NORTHERN STREAM FLOW THEN EXITS THIS TROUGH AND LIFTS
UP INTO SOUTHERN CANADA BEFORE TURNING EASTWARD INTO A MORE ZONAL
PATTERN ALL THE WAY TO NOVA SCOTIA. REMOVED FROM THE NORTHERN STREAM
FLOW WE FIND A POTENT UPPER LEVEL LOW QUICKLY PIVOTING TO THE
NORTHEAST FROM THE CENTRAL PLAINS TO THE GREAT LAKES REGION/UPPER
MIDWEST. A SURFACE REFLECTION LOW UNDERNEATH THIS SYSTEM IS LIFTING
THROUGH THE UPPER MIDWEST WITH A TRAILING COLD FRONT ALL THE WAY
SOUTH TO THE NORTHEAST GULF OF MEXICO. WV IMAGERY SHOWS A DEEP
SOUTHERLY MOISTURE PLUME SPREADING NORTHWARD AHEAD OF THIS FRONT AND
INTO THE PARENT SYSTEM. PLENTY OF INCLEMENT WEATHER ONGOING FROM THE
GREAT LAKES SOUTHWARD ALONG THE FRONT TO THE FLORIDA PANHANDLE.
A LITTLE CLOSER TO HOME...WE ARE STILL OUT AHEAD OF THIS COLD FRONT
WITHIN AN UNSEASONABLE WARM AND HUMID AIRMASS. THE STRONG UPPER
RIDGE THAT DOMINATED OUR WEATHER THIS PAST WEEKEND STILL HAS SOME
INFLUENCE ON THE REGION...ESPECIALLY THE CENTRAL AND SOUTHERN PARTS
OF THE PENINSULA FOR TODAY...HOWEVER A GLANCE AT THE 12Z KTBW
SOUNDING PROFILE SHOWS THAT THE DEPTH AND STRENGTH OF THE RIDGE AND
RESULTING OVERALL SUPPRESSION HAS DECREASED IN THE PAST 24 HOURS.
THE SUBSIDENCE INVERSION IS NOW MUCH HIGHER LOCATED AROUND 600MB
COMPARED TO BETWEEN 850-700MB SUNDAY MORNING. AS A RESULT...THE
COLUMN PW HAS ALSO COME UP SUBSTANTIALLY...FROM WELL UNDER 1"
SUNDAY MORNING TO AROUND 1.5" THIS MORNING.
AT THE SURFACE...MAIN RIDGE OF HIGH PRESSURE HAS SHIFTED OFF THE
CAROLINA COAST INTO THE WESTERN ATLANTIC...WITH AN EXTENSION OF THE
RIDGE OFF TO THE SOUTHWEST ACROSS THE CENTRAL/SOUTHERN FLORIDA
PENINSULA/SW GULF OF MEXICO. OUR LOW LEVEL FLOW HAS VEERED TO A MORE
SOUTHERLY DIRECTION BETWEEN THIS RIDGE AND THE SLOWLY APPROACHING
COLD FRONT...CURRENTLY LOCATED OVER THE FL PANHANDLE/NORTH-CENTRAL
GULF. THE SOUTHERLY FLOW AND ABUNDANT LOW LEVEL MOISTURE KEPT
TEMPERATURES EARLY THIS MORNING WELL ABOVE NORMAL...STARTING THE DAY
OUT WITH MOST LOCATIONS IN THE 70S! QUITE A BIT OF LOW STRATUS
DEVELOPMENT EARLY THIS MORNING WITH ALL THE AVAILABLE MOISTURE UNDER
THE UPPER RIDGE. WILL SEE MOSTLY CLOUDY SKIES WITH BREAKS OF SUN
GIVE WAY TO A MIX OF SUN AND CLOUDS THROUGH MIDDAY. REGIONAL RADARS
ARE QUIET AROUND THE PENINSULA...WITH THE NEAREST ORGANIZED
RAINFALL LOCATED ALONG THE FRONT OVER THE FL PANHANDLE.
REST OF TODAY...FORECAST AREA WILL REMAIN WITHIN THE WARM SECTOR
AHEAD OF THE FRONT THROUGHOUT THE DAY. EVEN WITH PLENTY OF CLOUDS
TODAY...LOOKING FOR ENOUGH SUNNY BREAKS TO RESULT IN ANOTHER WELL
ABOVE AVERAGE DAY IN TERMS OF TEMPERATURE AND HUMIDITY. NOT HARD
TO ACCOMPLISH THAT WHEN YOUR 8AM TEMPERATURES ARE ALREADY
SURPASSING YOUR NORMAL HIGHS FOR THE DATE. THE LOW LEVEL POTENTIAL
OF THE ATMOSPHERE IN TERMS OF TEMPERATURES IS VERY HIGH...WITH
850MB TEMPERATURES AROUND 16C (WELL OVER THE 90TH PERCENTILE FOR
MID- DECEMBER). IN FACT THE 12Z KTBW SOUNDING SHOWED A 16C
TEMPERATURE AS HIGH AS 825MB. ALONG THE SAME SUBJECT...TO SHOW
JUST HOW ABNORMAL THE WARMTH OF THE COLUMN IS OVER OUR HEADS...THE
12Z KTBW SOUNDING ALSO MEASURED A 700MB TEMPERATURE OF 9C (WELL
OVER THE 90TH PERCENTILE FOR MID-DECEMBER)...AND THE 500MB
TEMPERATURE WAS MEASURED AT -3.1C. THIS VALUE TIES THE WARMEST
EVER 500MB TEMP OBSERVED FOR KTBW IN DECEMBER. ONE OTHER
TIME...-3.1C WAS OBSERVED ON DECEMBER 7TH...MAKING THIS THE LATEST
SUCH A VALUE HAS EVEN OCCURRED. VERY IMPRESSIVE INDEED. GIVEN HOW
WARM THE COLUMN IS...EVEN BRIEF PEAKS OF THE SUN WILL QUICKLY
BOOST OUR TEMPERATURES INTO THE LOW/MID 80S AWAY FROM THE
IMMEDIATE COAST. WIND HAVE ALREADY COME AROUND TO THE SOUTH...AND
SHOULD DEVELOP AN ONSHORE COMPONENT DURING THE AFTERNOON. THIS
ONSHORE COMPONENT OFF THE "RELATIVELY" COOLER SHELF WATERS SHOULD
HELP KEEP TEMPS AT THE BEACHES DOWN IN THE 70S.
DUE TO THE DEEPER MOISTURE IN PLACE...AN ISOLATED SHOWER OR TWO IS
POSSIBLE ACROSS MAINLY THE INTERIOR ZONES THIS AFTERNOON/EARLY
EVENING...BUT COVERAGE WILL BE SPARSE AT BEST AND BARELY WORTH
MENTION IN THE FORECAST. WE DO HAVE A BAND OF SHOWERS APPROACHING
THE NATURE COAST FROM THE WEST...BUT PROGRESS IS VERY SLOW AS THE
FRONTAL MOVEMENT SLOWS. ALSO...ALL THE SYNOPTIC FORCING FOR LIFT
ASSOCIATED WITH THE PARENT SYSTEM IS QUICKLY EXITING WELL NORTH OF
THE REGION AND WILL BE COMPLETELY GONE BY LATER TODAY. THIS LOSS OF
LARGE SCALE ASCENT...AND GRADUAL STRETCHING/SLOWING OF THE FRONT
AND LOSS OF LOW LEVEL FOCUS SHOULD RESULT IN LESS ORGANIZED AND
LESS COVERAGE OF SHOWERS AS THE FRONT MOVES EAST LATER TODAY. ONLY
HAVE A 20% POP OVER LEVY COUNTY LATE THIS AFTERNOON INTO THE
EVENING FOR THESE REASONS.
TONIGHT/TUESDAY...WEAK FRONTAL STRUCTURE LAYS OUT ACROSS THE FLORIDA
BIG BEND AND BECOMES QUASI-STATIONARY BY TUESDAY MORNING. THIS IS A
FAR SOUTH AS THE BOUNDARY WILL MAKE IT BEFORE RETREATING NORTHWARD
AS A WARM FRONT INTO AL/GA ON WEDNESDAY. NO RELIEF FROM THE WARMTH
AND HUMIDITY WITH THIS FRONT IS IN THE FORECAST. LOW TEMPERATURES
TONIGHT WILL AGAIN BOTTOM OUT ONLY IN THE MID/UPPER 60S FOR THE
COOLER SPOTS...WITH MANY LOCATIONS NEAR THE COAST HOLDING IN THE
LOWER 70S. AS WE HEAD DEEPER INTO THE OVERNIGHT AND THE FRONT
SETTLES INTO POSITION NEAR LEVY/CITRUS/HERNANDO/SUMTER
COUNTIES...SOME UPTICK IN SHOWER ACTIVITY IS SHOWN BY MANY OF THE
GUIDANCE MEMBERS. WOULD EXPECT TO KEEP AT LEAST CHANCE POPS FOR
SHOWERS AFTER MIDNIGHT ACROSS THESE NORTHERN ZONES...WITH ISOLATED
SHOWER CHANCES AS FAR SOUTH AS AROUND THE I-4 CORRIDOR BY DAWN.
LAST FEW RUNS OF THE SREF MEMBERS HAVE POINTED TO A HIGH POTENTIAL
FOR WIDESPREAD LOW STRATUS/AREAS OF FOG LATER TONIGHT INTO TUESDAY
MORNING. SIMILAR TO LAST NIGHT...LEANING TOWARD BETTER CHANCES FOR A
LOW IFR STRATUS EVENT...BUT LIKELY TO SEE SOME DENSE FOG IN A FEW
SPOTS...ESPECIALLY SOUTH OF ANY SHOWER ACTIVITY.
TUESDAY...WEAK STATIONARY FRONT REMAINS IN PLACE OVER THE NORTHERN
PENINSULA. MOISTURE PROFILES AND WEAK LOW LEVEL FOCUS ALONG THE
BOUNDARY SHOULD BE ENOUGH TO KEEP AT LEAST A CHANCE OF SHOWERS IN
THE FORECAST ALONG AND NORTH OF THE I-4 CORRIDOR. THE DRIER WEATHER
AND BETTER CHANCES FOR SUNNY BREAKS WILL CERTAINLY EXIST TO THE
SOUTH OF THE TAMPA BAY AREA TOMORROW...WHERE TEMPERATURES AGAIN
BOOST INTO THE 80S AWAY FROM THE BEACHES FOR THE AFTERNOON. WITH
MORE CLOUDS AND OCCASIONAL SHOWER POTENTIAL...WILL LIMIT TEMPS IN
THE MID/UPPER 70S NORTH OF I-4. WHILE MAINLY ANTICIPATING SCT
SHOWERS TOMORROW. GFS/NAM BOTH INDICATE SHOWALTER INDICES AROUND
ZERO OVER THE NATURE COAST TOMORROW...SO A FEW TICKS OF LIGHTNING
CAN NOT BE RULED OUT...AND WILL ADD ISOLATED STORMS TO THE GRIDS.
&&
.AVIATION...
QUITE A BIT OF LOWER STRATUS AND RESULTING IFR/MVFR CONDITIONS
ACROSS THE REGION THIS MORNING. THE STRATUS IS FAIRLY THIN...SO
SHOULD BEGIN TO SEE IMPROVEMENT AFTER 15-16Z...WITH GENERAL VFR
CONDITIONS OR HIGH END MVFR THROUGH THE AFTERNOON/EVENING.
POTENTIAL FOR ANOTHER WIDESPREAD LOWER STRATUS/FOG EVENT IS
INCREASING FOR THE SECOND HALF OF TONIGHT AND TUESDAY MORNING.
WILL CONTINUE TO MONITOR GUIDANCE TRENDS...BUT LIKELY AT LEAST
MVFR RESTRICTIONS WILL BE ADDED TO THE 18Z TAFS AFTER 06Z TUESDAY
MORNING.
&&
.MARINE...
A WEAK COLD FRONT WILL SLOWLY APPROACH THE REGION TODAY AND STALL
ACROSS THE NORTHEAST GULF OF MEXICO TONIGHT AND TUESDAY. WINDS
WILL GENERALLY REMAIN OUT OF THE SOUTH AHEAD OF THIS FRONT...BUT
MAY BRIEFLY SHIFT TO THE NORTHEAST OFF THE LEVY/CITRUS COUNTY
COASTS ON TUESDAY. THIS FRONT WILL THEN LIFT BACK NORTH ON
WEDNESDAY WITH A CONTINUATION OF SOUTHERLY FLOW ACROSS THE EASTERN
GULF. WINDS AND SEAS ARE FORECAST TO GENERALLY REMAIN BELOW
HEADLINE CRITERIA THROUGH MID-WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 80 69 80 67 / 10 20 30 10
FMY 83 69 84 69 / 10 10 20 10
GIF 83 67 82 68 / 10 10 20 10
SRQ 79 68 80 68 / 10 10 20 10
BKV 82 67 80 66 / 10 20 50 20
SPG 79 69 79 69 / 10 20 30 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THIS EVENING FOR COASTAL
MANATEE-COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
UPDATE/AVIATION/MARINE...MROCZKA
DECISION SUPPORT...CARLISLE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
648 AM EST MON DEC 14 2015
.UPDATE...
A LITTLE FINE TUNING OF POP AND WX...NOT MUCH ELSE. VERY LOW
TOPPED AND NARROW LINE OF CONVECTION. STILL NO CG OR TOTAL
LIGHTNING DETECTED THAT WE KNOW OF. CLEARING WILL TAKE PLACE
QUICKLY THIS AFTERNOON.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 343 AM EST MON DEC 14 2015/
SHORT TERM /TODAY THROUGH TUESDAY/...
NARROW LINE OF CONVECTION WITH NO OBSERVABLE CG OR TOTAL LIGHTNING
CONTINUING TO TRAVEL EAST AT 20KTS AND SHOULD ARRIVE IN NW CORNER OF
STATE AROUND 6AM. HAVE TIGHTENED UP POP GRADIENTS AND TIMING BASED
ON 2-RUN TIME-LAGGED ENSEMBLE HRRR AND LOCAL HIRES MODEL GUIDANCE.
COULD SEE SOME SCT -SHRA AHEAD OF LINE BUT COVERAGE APPEARS TO BE 10-
20PCT BASED ON RADAR TRENDS. WITH 850-500MB MEAN RH DIPPING BELOW
10PCT BEHIND FRONT/CONVECTIVE LINE...EXPECT RAPID CLEARING OF CLOUDS
THIS AFTERNOON. GUIDANCE BLEND WITH MAX TEMPS IN THE UPPER 60S TO
UPPER 70S LOOKS GOOD. REST OF SHORT TERM PERIOD LOOKS CLEAR WITH
SW FLOW ALOFT CONTINUING AND ABOVE NORMAL TEMPS. NO WEATHER IMPACTS.
SNELSON
LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD STARTS OFF AS DRY BUT ALREADY SOME MODEL
DIFFERENCES EMERGE. BOTH THE GFS AND ECMWF HAVE FRONTAL BOUNDARY
ACROSS THE NORTHERN GULF AND INTO THE PANHANDLE OF FLORIDA BY 12Z
WED BUT THE GFS IS MORE AGGRESSIVE WITH ITS DEEP LAYER MOISTURE
TRANSPORT NORTHWARD. GFS SEEMS A LITTLE FAST AT THIS POINT AND
HAVE FAVORED THE ECMWF AND KEPT POPS SOUTH OF THE AREA INITIALLY.
REGARDLESS OF THE MODEL OF CHOICE...BY THE END OF THE DAY
WED...LOW PRESSURE FORMING OFF THE COAST OF LOUISIANA ALONG WITH
MODERATE ISENTROPIC ASCENT SHOULD ALLOW FOR THE DEVELOPMENT OF
WIDESPREAD LIGHT TO MODERATE RAIN. ALTHOUGH WITH THIS SETUP
SURFACE INSTABILITY WILL BE LITTLE TO NONE...40 KTS OF ISENTROPIC
FLOW ALONG WITH MARGINAL MID LEVEL LAPSE RATES SHOULD RESULT IN ELEVATED
CONVECTION FOR ALL OF CENTRAL AND MOST OF NORTH GEORGIA.
HAVE CONTINUED THE HIGH POPS IN THE GRIDS AS WELL GIVEN THE
CONSISTENCY OF THE MODEL DEPICTIONS WITH CATEGORICAL FOR MOST
AREAS. LOW LIFTS NORTH OF THE AREA BY 12Z THU WITH SOUTHERLY FLOW
DEVELOPING FOR THE SOUTHEAST CORNER. SHOULD SEE SOME SURFACE
INSTABILITY AS A RESULT AND WITH DECENT SHEAR VALUES...WILL NEED
TO MONITOR EVOLUTION OF THIS SYSTEM CLOSELY.
FRONT MOVES THROUGH BY THU NIGHT WITH A SECONDARY DRY FRONT MOVING
THROUGH ON FRIDAY. THIS SHOULD FINALLY BRING SOME COOLER TEMPS TO
THE AREA BUT MAY BE ONLY GOOD ENOUGH TO GET US BACK TO CLIMO OR
JUST BELOW FOR A DAY OR TWO BEFORE MODERATION TAKES PLACE.
DEESE
&&
.AVIATION...
12Z UPDATE...
PERIODS OF VERY LIGHT SHRA OR DZ LIKELY BEFORE LINE MOVES IN.
SHOULD REACH KATL AROUND 15Z. WINDS SHOULD REMAIN JUST EAST OF DUE
SOUTH WITH GUSTS TO 25KTS UNTIL LINE/FRONT MOVES THROUGH THEN
WEST THEN SW WITH DECREASING SPEEDS THROUGH THE DAY.
//ATL CONFIDENCE...12Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 70 47 69 42 / 70 5 0 0
ATLANTA 69 47 68 45 / 100 0 0 0
BLAIRSVILLE 65 42 66 39 / 100 0 0 0
CARTERSVILLE 68 44 66 40 / 100 0 0 0
COLUMBUS 70 46 71 46 / 100 0 0 0
GAINESVILLE 67 47 67 44 / 100 0 0 0
MACON 74 45 72 43 / 50 5 0 0
ROME 67 42 66 39 / 100 0 0 0
PEACHTREE CITY 69 43 69 39 / 100 0 0 0
VIDALIA 78 53 73 51 / 30 20 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR THE FOLLOWING
ZONES: CATOOSA...CHATTOOGA...DADE...FANNIN...FLOYD...GILMER...
GORDON...LUMPKIN...MURRAY...TOWNS...UNION...WALKER...WHITE...
WHITFIELD.
&&
$$
SHORT TERM...SNELSON
LONG TERM....DEESE
AVIATION...SNELSON
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
634 AM CST MON DEC 14 2015
.UPDATE...
Issued at 634 AM CST MON DEC 14 2015
Updated aviation discussion only.
&&
.SHORT TERM...(Today through Wednesday night)
Issued at 410 AM CST MON DEC 14 2015
The primary rain shield should be out of ern parts of the PAH
forecast area by around sunrise, with scattered light showers
possible almost everywhere through mid afternoon, then back to dry
conditions.
A vigorous low pressure system just to the west of the PAH
forecast area will continue to move rapidly northeastward toward
the Great Lakes today. As this occurs through the late morning and
early afternoon, there will still be a decent pressure gradient
across our region. A blend of RAP and NAM data suggested that
mixing down of just below wind advisory winds will occur today.
Gusts into the middle 30s kts appear possible. Without a sfc
focusing mechanism for enhanced lift, there is no plan to hoist a
wind advisory today, though there will be some substantial wind
for a few hours at any one spot. The swrly winds should steadily
decrease after sunset, and skies will gradually clear from the sw.
Our region will be under a brief period of ridging between
systems, then another vigorous low pressure system, further away
this time, is progged to move across the nrn Plains and into the
Great Lakes region by Wednesday. Moisture return is expected to be
limited, and therefore PoPs/QPF are limited with this system.
.LONG TERM...(Thursday through Sunday)
Issued at 410 AM CST MON DEC 14 2015
Above average confidence in the long term period as latest model
runs in good agreement and very little to discuss.
For the most part, high pressure at the surface and broad cyclonic
flow aloft will dominate the region`s weather Thursday and Friday.
Models bring a short wave across the area Thursday night but with no
surface reflection and very limited moisture, only an increase in
cloud cover is expected.
Beyond that, high pressure will remain over the area at the
surface but heights aloft will be on the increase which will
continue to keep the region dry, with temperatures warming back
to above normal through the end of the period.
The next chance of precipitation appears to be next Monday as a
system moves out of the plains, but for now that is just beyond the
scope of this forecast package and is for planning purposes only.
&&
.AVIATION...
Issued at 634 AM CST MON DEC 14 2015
Southwesterly winds are expected to kick up above 30 kts in gusts
for a few hours during the daylight hours today, first in the west
by mid morning, then in the east by early afternoon. Winds will
diminish to below 10 kts after midnight. Expect MVFR cigs through
mid afternoon, with some intervals of VFR cigs possible, after which
cigs will rise to VFR or just under. Though there are still some
scattered light showers possible through mid afternoon, they are not
expected to reduce vsbys significantly.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DB
LONG TERM...JP
AVIATION...DB
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
411 AM CST MON DEC 14 2015
.SHORT TERM...(Today through Wednesday night)
Issued at 410 AM CST MON DEC 14 2015
The primary rain shield should be out of ern parts of the PAH
forecast area by around sunrise, with scattered light showers
possible almost everywhere through mid afternoon, then back to dry
conditions.
A vigorous low pressure system just to the west of the PAH
forecast area will continue to move rapidly northeastward toward
the Great Lakes today. As this occurs through the late morning and
early afternoon, there will still be a decent pressure gradient
across our region. A blend of RAP and NAM data suggested that
mixing down of just below wind advisory winds will occur today.
Gusts into the middle 30s kts appear possible. Without a sfc
focusing mechanism for enhanced lift, there is no plan to hoist a
wind advisory today, though there will be some substantial wind
for a few hours at any one spot. The swrly winds should steadily
decrease after sunset, and skies will gradually clear from the sw.
Our region will be under a brief period of ridging between
systems, then another vigorous low pressure system, further away
this time, is progged to move across the nrn Plains and into the
Great Lakes region by Wednesday. Moisture return is expected to be
limited, and therefore PoPs/QPF are limited with this system.
.LONG TERM...(Thursday through Sunday)
Issued at 410 AM CST MON DEC 14 2015
Above average confidence in the long term period as latest model
runs in good agreement and very little to discuss.
For the most part, high pressure at the surface and broad cyclonic
flow aloft will dominate the region`s weather Thursday and Friday.
Models bring a short wave across the area Thursday night but with no
surface reflection and very limited moisture, only an increase in
cloud cover is expected.
Beyond that, high pressure will remain over the area at the
surface but heights aloft will be on the increase which will
continue to keep the region dry, with temperatures warming back
to above normal through the end of the period.
The next chance of precipitation appears to be next Monday as a
system moves out of the plains, but for now that is just beyond the
scope of this forecast package and is for planning purposes only.
&&
.AVIATION...
Issued at 410 AM CST MON DEC 14 2015
Aside from strong southwesterly winds during the daylight hours
today, expect MVFR cigs through mid afternoon, after which cigs
will rise to VFR. MVFR vsbys in rain are still possible through
sunrise in the east. Though there are still some scattered showers
possible through mid afternoon, they are not expected to reduce
vsbys significantly.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
SHORT TERM...DB
LONG TERM...JP
AVIATION...DB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
646 AM EST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 14 2015
WV IMAGERY SHOWS MID-UPPER LOW SPINNING ALONG KS/MO BORDER AS IT
LIFTS SLOWLY NE EARLY THIS MORNING. IMPRESSIVE MOISTURE PLUME NOTED
AHEAD OF LOW WITH CLASSIC BAROCLINIC LEAF STRUCTURE AS MOISTURE
WRAPS BACK INTO COMMA HEAD NORTH OF LOW. INCREASING UPPER DIFFLUENCE
AND DEEP LAYER Q-VECT CONVERGENCE AHEAD OF THE APPROACHING LOW ALONG
WITH INCREASING 850-700 MB FGEN ENHANCED BY COUPLED UPPER JET
STRUCTURE HAS ALLOWED HEAVIER RAIN BAND TO SPREAD INTO SOUTH CENTRAL
AND EASTERN UPPER MI EARLY THIS MORNING. MEANWHILE A NE FLOW OF
DRIER FEEDING FROM NORTH OF LAKE SUPERIOR HAS KEPT THE NW HALF OF
UPPER MI GENERALLY DRY OVERNIGHT WITH LITTLE MORE THAN DRIZZLE
REPORTED.
TODAY...AS NEG-TILT MID-UPPER LEVEL TROUGH AND EMBEDDED CLOSED LOW
CONTINUE TO LIFT NE INTO THE UPPER GREAT LAKES REGION DEEP LAYER Q-
VECT CONVERGENCE AND MID-LVL FGEN FORCING WILL CONTINUE TO SPREAD
NORTHWARD ACROSS FORECAST AREA ALLOWING BAND OF HEAVY RAIN ASSOC
WITH DEFORMATION AREA/COMMA HEAD OF SYSTEM TO SPREAD NORTHWARD AND
WESTWARD THROUGH THE DAY. WITH COMBINATION OF STRONG FORCING AND
INCREDIBLE PRECIPITABLE WATER VALUES OF 1-1.3 INCHES MUCH OF THE
FORECAST COULD SEE RAIN AMOUNTS FROM 1-1.7 INCHES TODAY HEAVIEST
SOUTH CENTRAL AND EAST. TRICKY PORTION OF FORECAST THIS AFTERNOON
WILL BE TIMING OF CHANGEOVER FROM RAIN TO SNOW IN FAR WEST. MODELS
VARY GREATLY IN THIS REGARD...WITH THE GFS AND PARTICULARLY THE NAM
MORE AGGRESSIVE WITH CHANGEOVER TO SNOW THAN THE RAP PERHAPS
INDICATING POTENTIAL FOR DYNAMIC COOLING FROM STRONG FORCING WITHIN
COMMA HEAD OF SYSTEM. GIVEN MODEL UNCERTAINTY...I ONLY HAVE AN INCH
OR TWO OF SLUSHY ACCUMULATION LATE THIS AFTERNOON INTO THIS EVENING
FOR FAR WEST...BUT CERTAINLY NOT OUT OF QUESTION THAN THERE COULD BE
MORE SNOW FOR GOGEBIC-ONTONAGON COUNTIES IF CHANGEOVER OCCURS WHILE
DEFORMATION PRECIP BAND IS OVER AREA. THIS WILL BE SOMETHING FOR
DAYSHIFT TO CLOSELY MONITOR THIS AFTERNOON AS A QUICKER CHANGEOVER
TO SNOW COULD WARRANT A HEADLINE FOR POTENTIAL ADVISORY SNOWFALL
AMOUNTS.
TONIGHT...AS THE LOW DEPARTS EAST OF THE AREA THIS EVENING...COLDER
AIR PUSHING IN BEHIND THE SYSTEM WILL ALLOW FOR CONTINUED TRANSITION
OF PRECIPITATION FROM RAIN TO SNOW SPREADING WEST TO EAST. AS
WRAPAROUND MOISTURE DEAPRTS EAST WITH COMMA HEAD OF SYSTEM...FCST
SOUNDINGS SUGGEST MID LEVEL DRYING WITHIN DGZ WHICH COULD ALSO
RESULT IN FORMATION OF DRIZZLE OR FREEZING DRIZZLE SO HAVE INCLUDED
THIS IN FORECAST AS WELL.
HIGH TEMPERATURES TODAY WILL RANGE FROM MID TO UPPER 30S WEST TO
AROUND 50F EAST AND SOUTHEAST. LOWS TONIGHT WILL DROP INTO THE UPPER
20S WEST TO LOWER TO MID 30S SOUTH CENTRAL AND EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON DEC 14 2015
AS THE LOW DEPARTS TO THE EAST ON TUESDAY...THE MODELS INDICATE
PLENTY OF LOW LEVEL MOISTURE TRAPPED UNDER THE STRONG INVERSION
ACROSS THE AREA. MODEL SOUNDINGS SUGGEST THAT THE CLOUD LAYER WILL
BE ABOUT 2000 FT WITH ALL TEMPERATURES GENERALLY ABOVE -10C. THIS
WOULD IMPLY LIMITED ICE NUCELI AVALABILITY LEADING TO PERHAPS A
DRIZZLE/FREEZING DRIZZLE EVENT IN THE FAVORED UPSLOPE AREAS DURING
THE DAY ON TUESDAY. HOWEVER...AS SEEN ON FRIDAY NIGHT...THE CLOUD
LAYER MAY JUST BE COLD ENOUGH TO ALLOW FOR SNOW AS WELL. AS
SUCH...WILL GO WITH A SLIGHT CHANCE OF SNOW WITH PATCHY FZDZ/DZ IN
THE FAVORED UPSLOPE AREAS OF N-CENTRAL AND WEST UPPER MICHIGAN.
OTHERWISE...TUESDAY SHOULD BE A FAIRLY QUIET DAY ACROSS THE AREA
WITH WEAK FLOW BEFORE THE NEXT SYSTEM APPROACHES WED.
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE LOW TRACK FOR
WED WILL STAY WEST AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED. AS
SUCH...WILL LIKELY SEE A PERIOD OF PRECIPITATION MOVING FROM SOUTH
TO NORTH LATE TUE NIGHT INTO WED AS THE OCCLUDED FRONT MOVES ACROSS
THE AREA. THEN THE DRY SLOT WILL MOVE IN WED AFTN LIKELY CUTTING OFF
PRECIPITATION OR REDUCING IT TO DRIZZLE/FZDZ. PRECIPITATION TYPE
WILL BE A LITTLE TRICKIER WITH THIS SYSTEM AS THERE WILL BE A LITTLE
MORE COLD AIR AVAILABLE. AM EXPECTING ANY PRECIPITAITON LATE TUE
NIGHT WILL BE FROZEN...BUT QUICKLY TURN TO LIQUID WED MORNING. COULD
POTENTIALLY SEE A LITTLE FREEZING RAIN ACROSS THE SOUTH CENTRAL BUT
IT SHOULD BE BRIEF AS ANY SURFACE TEMPERATURES BELOW FREEZING SHOULD
RISE TO ABOVE FREEZING DUE TO LATENT HEATING EFFECTS. WILL MAINTAIN
LIKELY POPS ACROSS THE AREA ON WEDNESDAY TAPERING TO CHANCE IN THE
AFTN AND EVENING.
THE BIG STORY WITH THIS SYSTEM WILL BE THE COLDER AIRMASS ASSOCIATED
WITH IT FOR THE END OF THE WEEK INTO SATURDAY. BY 12Z THURSDAY THE
LOW WILL BE NORTH OF LAKE SUPERIOR WITH 850MB TEMPS DROPPING TO -11C
ACROSS THE WESTERN PART OF LAKE SUPERIOR. STRONGLY CYCLONIC FLOW AND
DEEP MOISTURE SHOULD ALLOW FOR LAKE EFFECT SNOW TO DEVELOP LATE WED
NIGHT AND CONTINUE THROUGH FRIDAY AT LEAST. W-NW FLOW INITIALLY ON
THURSDAY SHOULD ALLOW FOR THE WEST TO SEE ACCUMULATING LES. THEN ON
THU NIGHT INTO FRI A SECONDARY TROUGH MOVES THROUGH ALLOWING THE LES
TO BECOME BETTER ORGANIZED EAST OF MARQUETTE INTO ALGER/LUCE/NRN
SCHOOLCRAFT COUNTIES. WIND DIRECTION STILL NOT FAVORABLE FOR LES IN
MARQUETTE COUNTY THOUGH. WARM ADVECTION COMMENCES SAT AFTN INTO
SUNDAY AS THE RIDGE BUILDS TO THE WEST OF THE AREA...HELPING TO END
ANY LES BY SATURDAY EVENING. STILL FAIRLY FAR OUT TO BE TALKING
ACCUMULATIONS AT THE END OF THE WEEK...BUT THE LES PARAMETER IS VERY
HIGH /AROUND 2/ OWING TO THE DEEP MOISTURE AND COLD 850MB TEMPS. WITH
THE LONGEVITY OF THE LES...IT CERTAINLY DOES NOT SEEM OUT OF THE
QUESTION THAT SOME PLACES FROM ONTONAGON TO THE KEWEENAW PENINSULA
AND IN ALGER/LUCE COUNTIES COULD SEE PLOWABLE SNOWFALL AT THE END OF
THE WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 625 AM EST MON DEC 14 2015
IFR/LIFR CIGS AND VSBYS CONTINUE THROUGH THE FORECAST. NORTHEAST WINDS
WILL BE GUSTY AT ALL THREE TAF SITES AS THE PRESSURE GRADIENT
TIGHTENS UP WITH THE APPROACH OF THE SFC LOW OUT OF THE CENTRAL
MISSISSIPPI VALLEY. THE STRONGEST GUSTS ARE EXPECTED TODAY INTO THE
EVENING HOURS WITH OCCASIONAL GUSTS UP TO AROUND 25 KNOTS
POSSIBLE. THE NEXT CONCERN IS THE PHASE CHANGE FROM RAIN TO SNOW AS
COLDER AIR GET PULLED INTO THE AREA WITH THE SYSTEM EXITING TO THE
EAST. EXPECT RAIN TO CHANGE TO SNOW AT KIWD AROUND 21Z...AT KCMX AFT
00Z AND KSAW AROUND 06Z. SOME DRIZZLE IS ALSO POSSIBLE TONIGHT WITH
FREEZING DRIZZLE POSSIBLE OVER THE WESTERN TAF SITES AS MID-LEVELS
DRY OUT BUT LOW-LEVEL MOISTURE REMAINS. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EST MON DEC 14 2015
THE SURFACE LOW OVER IOWA WILL MOVE NORTHEASTWARD ACROSS THE EASTERN
UP BY THIS AFTERNOON. NORTHEAST GALES WILL CONTINUE ACROSS THE NORTH
CENTRAL AND WESTERN LAKES TODAY AND EXPAND INTO THE SOUTH CENTRAL
AND EASTERN LAKES THIS AFTERNOON AND EVENING AS THE LOW MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE. THERE
IS A POTENTIAL FOR A FEW STORM FORCE GUSTS THIS AFTERNOON BETWEEN
ISLE ROYALE AND THE KEWEENAW. WINDS WILL ONLY SUBSIDE TEMPORARILY ON
TUESDAY MORNING BEFORE ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES
INTO THE UPPER GREAT LAKES FOR WEDNESDAY INTO THURSDAY. NORTHEAST
WINDS WILL INCREASE TO GALES OVER THE WEST HALF LATE TUE INTO WED
MORNING AND SOUTHEAST WINDS SHOULD REACH GALE FORCE OVER THE CENTRAL
AND EASTERN LAKE AHEAD OF THE LOW ON WEDNESDAY FOLLOWED BY WESTERLY
WINDS APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON
THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM NOON TODAY TO 7 AM EST TUESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST TUESDAY FOR LSZ265-266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ TUESDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...VOSS
LONG TERM...- NONE -
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
523 AM EST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 14 2015
WV IMAGERY SHOWS MID-UPPER LOW SPINNING ALONG KS/MO BORDER AS IT
LIFTS SLOWLY NE EARLY THIS MORNING. IMPRESSIVE MOISTURE PLUME NOTED
AHEAD OF LOW WITH CLASSIC BAROCLINIC LEAF STRUCTURE AS MOISTURE
WRAPS BACK INTO COMMA HEAD NORTH OF LOW. INCREASING UPPER DIFFLUENCE
AND DEEP LAYER Q-VECT CONVERGENCE AHEAD OF THE APPROACHING LOW ALONG
WITH INCREASING 850-700 MB FGEN ENHANCED BY COUPLED UPPER JET
STRUCTURE HAS ALLOWED HEAVIER RAIN BAND TO SPREAD INTO SOUTH CENTRAL
AND EASTERN UPPER MI EARLY THIS MORNING. MEANWHILE A NE FLOW OF
DRIER FEEDING FROM NORTH OF LAKE SUPERIOR HAS KEPT THE NW HALF OF
UPPER MI GENERALLY DRY OVERNIGHT WITH LITTLE MORE THAN DRIZZLE
REPORTED.
TODAY...AS NEG-TILT MID-UPPER LEVEL TROUGH AND EMBEDDED CLOSED LOW
CONTINUE TO LIFT NE INTO THE UPPER GREAT LAKES REGION DEEP LAYER Q-
VECT CONVERGENCE AND MID-LVL FGEN FORCING WILL CONTINUE TO SPREAD
NORTHWARD ACROSS FORECAST AREA ALLOWING BAND OF HEAVY RAIN ASSOC
WITH DEFORMATION AREA/COMMA HEAD OF SYSTEM TO SPREAD NORTHWARD AND
WESTWARD THROUGH THE DAY. WITH COMBINATION OF STRONG FORCING AND
INCREDIBLE PRECIPITABLE WATER VALUES OF 1-1.3 INCHES MUCH OF THE
FORECAST COULD SEE RAIN AMOUNTS FROM 1-1.7 INCHES TODAY HEAVIEST
SOUTH CENTRAL AND EAST. TRICKY PORTION OF FORECAST THIS AFTERNOON
WILL BE TIMING OF CHANGEOVER FROM RAIN TO SNOW IN FAR WEST. MODELS
VARY GREATLY IN THIS REGARD...WITH THE GFS AND PARTICULARLY THE NAM
MORE AGGRESSIVE WITH CHANGEOVER TO SNOW THAN THE RAP PERHAPS
INDICATING POTENTIAL FOR DYNAMIC COOLING FROM STRONG FORCING WITHIN
COMMA HEAD OF SYSTEM. GIVEN MODEL UNCERTAINTY...I ONLY HAVE AN INCH
OR TWO OF SLUSHY ACCUMULATION LATE THIS AFTERNOON INTO THIS EVENING
FOR FAR WEST...BUT CERTAINLY NOT OUT OF QUESTION THAN THERE COULD BE
MORE SNOW FOR GOGEBIC-ONTONAGON COUNTIES IF CHANGEOVER OCCURS WHILE
DEFORMATION PRECIP BAND IS OVER AREA. THIS WILL BE SOMETHING FOR
DAYSHIFT TO CLOSELY MONITOR THIS AFTERNOON AS A QUICKER CHANGEOVER
TO SNOW COULD WARRANT A HEADLINE FOR POTENTIAL ADVISORY SNOWFALL
AMOUNTS.
TONIGHT...AS THE LOW DEPARTS EAST OF THE AREA THIS EVENING...COLDER
AIR PUSHING IN BEHIND THE SYSTEM WILL ALLOW FOR CONTINUED TRANSITION
OF PRECIPITATION FROM RAIN TO SNOW SPREADING WEST TO EAST. AS
WRAPAROUND MOISTURE DEAPRTS EAST WITH COMMA HEAD OF SYSTEM...FCST
SOUNDINGS SUGGEST MID LEVEL DRYING WITHIN DGZ WHICH COULD ALSO
RESULT IN FORMATION OF DRIZZLE OR FREEZING DRIZZLE SO HAVE INCLUDED
THIS IN FORECAST AS WELL.
HIGH TEMPERATURES TODAY WILL RANGE FROM MID TO UPPER 30S WEST TO
AROUND 50F EAST AND SOUTHEAST. LOWS TONIGHT WILL DROP INTO THE UPPER
20S WEST TO LOWER TO MID 30S SOUTH CENTRAL AND EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON DEC 14 2015
AS THE LOW DEPARTS TO THE EAST ON TUESDAY...THE MODELS INDICATE
PLENTY OF LOW LEVEL MOISTURE TRAPPED UNDER THE STRONG INVERSION
ACROSS THE AREA. MODEL SOUNDINGS SUGGEST THAT THE CLOUD LAYER WILL
BE ABOUT 2000 FT WITH ALL TEMPERATURES GENERALLY ABOVE -10C. THIS
WOULD IMPLY LIMITED ICE NUCELI AVALABILITY LEADING TO PERHAPS A
DRIZZLE/FREEZING DRIZZLE EVENT IN THE FAVORED UPSLOPE AREAS DURING
THE DAY ON TUESDAY. HOWEVER...AS SEEN ON FRIDAY NIGHT...THE CLOUD
LAYER MAY JUST BE COLD ENOUGH TO ALLOW FOR SNOW AS WELL. AS
SUCH...WILL GO WITH A SLIGHT CHANCE OF SNOW WITH PATCHY FZDZ/DZ IN
THE FAVORED UPSLOPE AREAS OF N-CENTRAL AND WEST UPPER MICHIGAN.
OTHERWISE...TUESDAY SHOULD BE A FAIRLY QUIET DAY ACROSS THE AREA
WITH WEAK FLOW BEFORE THE NEXT SYSTEM APPROACHES WED.
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE LOW TRACK FOR
WED WILL STAY WEST AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED. AS
SUCH...WILL LIKELY SEE A PERIOD OF PRECIPITATION MOVING FROM SOUTH
TO NORTH LATE TUE NIGHT INTO WED AS THE OCCLUDED FRONT MOVES ACROSS
THE AREA. THEN THE DRY SLOT WILL MOVE IN WED AFTN LIKELY CUTTING OFF
PRECIPITATION OR REDUCING IT TO DRIZZLE/FZDZ. PRECIPITATION TYPE
WILL BE A LITTLE TRICKIER WITH THIS SYSTEM AS THERE WILL BE A LITTLE
MORE COLD AIR AVAILABLE. AM EXPECTING ANY PRECIPITAITON LATE TUE
NIGHT WILL BE FROZEN...BUT QUICKLY TURN TO LIQUID WED MORNING. COULD
POTENTIALLY SEE A LITTLE FREEZING RAIN ACROSS THE SOUTH CENTRAL BUT
IT SHOULD BE BRIEF AS ANY SURFACE TEMPERATURES BELOW FREEZING SHOULD
RISE TO ABOVE FREEZING DUE TO LATENT HEATING EFFECTS. WILL MAINTAIN
LIKELY POPS ACROSS THE AREA ON WEDNESDAY TAPERING TO CHANCE IN THE
AFTN AND EVENING.
THE BIG STORY WITH THIS SYSTEM WILL BE THE COLDER AIRMASS ASSOCIATED
WITH IT FOR THE END OF THE WEEK INTO SATURDAY. BY 12Z THURSDAY THE
LOW WILL BE NORTH OF LAKE SUPERIOR WITH 850MB TEMPS DROPPING TO -11C
ACROSS THE WESTERN PART OF LAKE SUPERIOR. STRONGLY CYCLONIC FLOW AND
DEEP MOISTURE SHOULD ALLOW FOR LAKE EFFECT SNOW TO DEVELOP LATE WED
NIGHT AND CONTINUE THROUGH FRIDAY AT LEAST. W-NW FLOW INITIALLY ON
THURSDAY SHOULD ALLOW FOR THE WEST TO SEE ACCUMULATING LES. THEN ON
THU NIGHT INTO FRI A SECONDARY TROUGH MOVES THROUGH ALLOWING THE LES
TO BECOME BETTER ORGANIZED EAST OF MARQUETTE INTO ALGER/LUCE/NRN
SCHOOLCRAFT COUNTIES. WIND DIRECTION STILL NOT FAVORABLE FOR LES IN
MARQUETTE COUNTY THOUGH. WARM ADVECTION COMMENCES SAT AFTN INTO
SUNDAY AS THE RIDGE BUILDS TO THE WEST OF THE AREA...HELPING TO END
ANY LES BY SATURDAY EVENING. STILL FAIRLY FAR OUT TO BE TALKING
ACCUMULATIONS AT THE END OF THE WEEK...BUT THE LES PARAMETER IS VERY
HIGH /AROUND 2/ OWING TO THE DEEP MOISTURE AND COLD 850MB TEMPS. WITH
THE LONGEVITY OF THE LES...IT CERTAINLY DOES NOT SEEM OUT OF THE
QUESTION THAT SOME PLACES FROM ONTONAGON TO THE KEWEENAW PENINSULA
AND IN ALGER/LUCE COUNTIES COULD SEE PLOWABLE SNOWFALL AT THE END OF
THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 106 AM EST MON DEC 14 2015
IFR/LIFR CIGS AND VSBYS CONTINUE THROUGH THE FORECAST. EXPECT WINDS
TO BECOME GUSTY AT ALL THREE TAF SITES AS THE PRESSURE GRADIENT
TIGHTENS UP WITH THE APPROACH OF THE SFC LOW OUT OF THE CENTRAL
MISSISSIPPI VALLEY. THE STRONGEST GUSTS ARE EXPECTED DURING THE
AFTERNOON AND EARLY EVENING HOURS WITH OCCASIONAL GUSTS UP TO AROUND
30 KNOTS POSSIBLE..ESPECIALLY AT KCMX AND KSAW. THE NEXT CONCERN IS
THE PHASE CHANCE FROM RAIN TO SNOW. LATEST NAM MODEL RUN ATTEMPTING
TO MIX PRECIPITATION EARLIER IN THE DAY...BUT WITH THE ABUNDANCE OF
WARM AIR STILL ADVECTING INTO THE REGION THROUGH MUCH OF THE DAY
HAVE PUSHED BACK THE CHANGEOVER TO ALL SNOW CLOSER TO 0Z AT KCMX AND
KIWD...ALTHOUGH THERE WILL BE A MIX OF RAIN AND SNOW IN THE
AFTERNOON. KSAW WILL START TO SEE SNOW MIX IN WITH THE RAIN IN THE
LATE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EST MON DEC 14 2015
THE SURFACE LOW OVER IOWA WILL MOVE NORTHEASTWARD ACROSS THE EASTERN
UP BY THIS AFTERNOON. NORTHEAST GALES WILL CONTINUE ACROSS THE NORTH
CENTRAL AND WESTERN LAKES TODAY AND EXPAND INTO THE SOUTH CENTRAL
AND EASTERN LAKES THIS AFTERNOON AND EVENING AS THE LOW MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE. THERE
IS A POTENTIAL FOR A FEW STORM FORCE GUSTS THIS AFTERNOON BETWEEN
ISLE ROYALE AND THE KEWEENAW. WINDS WILL ONLY SUBSIDE TEMPORARILY ON
TUESDAY MORNING BEFORE ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES
INTO THE UPPER GREAT LAKES FOR WEDNESDAY INTO THURSDAY. NORTHEAST
WINDS WILL INCREASE TO GALES OVER THE WEST HALF LATE TUE INTO WED
MORNING AND SOUTHEAST WINDS SHOULD REACH GALE FORCE OVER THE CENTRAL
AND EASTERN LAKE AHEAD OF THE LOW ON WEDNESDAY FOLLOWED BY WESTERLY
WINDS APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON
THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING FROM NOON TODAY TO 7 AM EST TUESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST TUESDAY FOR LSZ265-266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ TUESDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-
250.
&&
$$
SHORT TERM...VOSS
LONG TERM...- NONE -
AVIATION...RJT
MARINE...VOSS
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
553 AM CST MON DEC 14 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 335 AM CST Mon Dec 14 2015
Although the period of steady rain has ended now that the axis
of strongest moisture convergence has progressed eastward, scattered
to numerous showers were still occurring early this morning farther
back over MO/KS/AR/OK. These showers are associated with the upper
low center, which was located near the MO/KS border at 09z per
satellite imagery and RAP analyses. These showers will accompany the
upper low today as it tracks northeastward from MO into IL/WI,
leading to periods of rain across MO/IL. Simultaneously, a vort lobe
rotating around the back side of the departing upper low may bring
an increased chance of showers to parts of northeast MO/west central
IL this aftn. The PoP grids attempt to reflect this complexity.
Stronger winds aloft will be transported down to the surface today,
leading to windy conditions at times. Both sustained winds and gusts
appear to remain below advisory criteria attm.
Non-diurnal temperatures are expected again today due to the
competing influences of CAA behind a cold front, diurnal warming,
and lingering precip/cloud cover.
Kanofsky
.LONG TERM: (Tonight through Sunday)
Issued at 335 AM CST Mon Dec 14 2015
(Tonight)
Dry weather is in the offing for the area as relatively narrow NW-SE
oriented surface ridge in the wake of today`s system passes through
the region. Primary question is cloud trends, and although the
tendency should be a clearing of the post system low cloudiness from
SW to NE guidance varies a great deal on how quickly this will
occur. MOS output based on the NAM...with its typically moist low
levels...holds onto a good deal of low cloudiness into Tuesday
morning, while GFS MOS certainly suggests a decrease in the cloud
cover. Given that the low level wind forecasts have a pronounced
westerly component that should aid in clearing of the low
cloudiness, will lean towards trends suggested by GFS MOS. Some
fog is certainly possible as well given the water-logged ground
across the region and decreasing winds as the surface ridge works
into the area, but will let day shift take another look at
this before including in forecast.
(Tuesday-Wednesday)
Heading into the middle of the week attention turns to potent and
fast moving upper level system that migrates from the central Plains
into the upper Mississippi Valley Tuesday afternoon-Wednesday
afternoon. With forcing well to the north and with limited moisture
return, it still appears rain threat with this system will be rather
low. Overall forecast trends remain the same, although did attempt
to fine-tune the timing of the rain threat just a bit due to the
good agreement in the 00z solutions WRT movement of upper level
features as well as surface cold front.
(Thursday-Sunday)
No major changes in forecast specifics during this time frame, with
all NWP solutions still indicating deep upper trof developing over
the central CONUS Thursday-Friday. The drop in heights over the
region should finally allow a much more typical early winter AMS to
settle into the mid Mississippi Valley, with 850mb temps of at
least -10C progged into the area by Friday morning. This cool
down should bring the CWA its first real taste of winter
temperatures with highs in the 30s to low 40s by Friday...first
time temps have been near or below their daily averages since
early this month.
However, it appears that these winter temperatures will be short-
lived, as progressive UA pattern allows strong ridging to build back
across the central CONUS during the upcoming weekend as deep trof
works its way into the eastern U.S. AMS over the region should
modify quickly during this transition, and the main question is
how fast this modification will occur. If tonight`s medium range
solutions are correct warmup could begin already on Saturday, but
given the fact that models are often too fast in a high amplitude
regime will keep Saturday`s temps on the cool side, and begin the
warmup in earnest on Sunday, with highs returning to the 40s and
50s.
It still appears that dry conditions will dominate the CWA during
the Thursday-Sunday temperature roller coaster.
Truett
&&
.AVIATION: (For the 12z TAFs through 12z Tuesday Morning)
Issued at 530 AM CST Mon Dec 14 2015
Scattered showers will continue this morning until an upper level
low pressure center has lifted northeast of the area. Brief
downpours have been observed with some of the showers, temporarily
reducing vsbys below 2 miles. Gusty southwest winds are expected
for most of the day with gusts reaching 20-30 kts. Winds should
decrease after 15/00z. Ceilings were highly variable overnight,
but a general improvement is expected for the first part of the
day until wrap-around clouds with MVFR bases arrive later this
morning and into the afternoon. There is some uncertainty on how
quickly these clouds will clear out tonight. Any areas which
experience partial clearing tonight should see patchy fog
development after due to light winds and moist ground conditions.
Kanofsky
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
714 AM EST MON DEC 14 2015
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TONIGHT. A WEAK COLD FRONT WILL
APPROACH FROM THE WEST MONDAY AND MOVE THROUGH THE REGION MONDAY
NIGHT. HIGH PRESSURE WILL BUILD IN FROM THE WEST BEHIND THE FRONT
TUESDAY AND SLIDE OFFSHORE WEDNESDAY. A STRONG COLD FRONT WILL
APPROACH FROM THE WEST THURSDAY AND CROSSES THE AREA FRIDAY. HIGH
PRESSURE WILL BUILD IN FROM THE WEST THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 7 AM MONDAY...MID AND HIGH CLOUDS CONTINUE TO INCREASE AND
COUPLED WITH 4-6 KNOT SOUTHERLY WINDS...THE PATCHY FOG HAS
DISSIPATED ACROSS THE REGION. LOW-LEVEL MOISTURE WILL CONTINUE TO
STEADILY INCREASE THROUGH THE DAY AHEAD OF COLD FRONT AS
PRECIPITABLE WATER VALUES FROM THE HRRR MODEL SURGES TO NEAR 2
INCHES BY LATE AFTERNOON. RADAR REFLECTIVITY PROGS FROM HRRR/RAP
AND 4KM NAM DO NOT SHOW MUCH IN THE WAY OF PRECIPITATION BEFORE
ABOUT 18Z WITH SHOWERS MOVING IN AFTER THAT AND CONTINUING INTO
THE EVENING. PER FORECAST SOUNDINGS...INSTABILITY IS LIMITED BUT
WITH WARM HIGH TEMPERATURES WELL INTO THE 70S...CONTINUED THE
MENTION OF A SMALL THREAT OF THUNDER TODAY. WOULD EXPECT THE
HEAVIEST OF ANY RAIN THAT FALLS TODAY TO BE NEAR THE COAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 320 AM MONDAY...RAIN WILL LINGER NEAR THE COAST THROUGH
ABOUT MIDNIGHT BEFORE RAPID CLEARING OCCURS BETWEEN 06Z AND 12Z
WITH DOWNSLOPING FLOW AND LOWERING DEWPOINTS. LOWS TONIGHT WILL BE
IN THE 50S AREA-WIDE...EXCEPT LOWER 60S ALONG THE OUTER BANKS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 3 AM MON...UNSEASONABLY WARM WEATHER TO CONTINUE THROUGH
THURSDAY THEN MUCH COLDER THIS WEEKEND.
TUESDAY THROUGH WEDNESDAY...WEAK HIGH PRESSURE BUILDS ACROSS FROM
THE WEST AS UPR RDG RE-BUILDS OVER REGION. MILD AND DRY WEATHER
WITH HIGHS IN THE UPR 60S TO LOW 70S TUE AND LOWS MID 40S INLAND
TO LOWER 50S CST. A FEW DEGREES COOLER FOR WED WITH LOW LEVEL NE/E
FLOW...HIGHS 60-70 DEG.
WEDNESDAY NIGHT THROUGH FRIDAY...MOISTURE SURGES NE INTO REGION
WED NIGHT...AS WARM FRONT LIFTS THROUGH THE AREA...AHEAD OF DEEP
BROAD UPPER TROF AND COLD FRONT TO THE W. COULD SEE NON-DIURNAL
TEMP CURVE AS SLY FLOW DEVELOPS. CHC POPS PROGGED TO DEVELOP
LATER WED NIGHT DEEP INLAND AND ALONG THE SOUTHERN COAST. PRECIP
CONTINUES OVER REGION THU INTO THU NIGHT WITH MOST MDLS SHOWING
PLENTY OF MOISTURE AND QPF. WILL CONTINUE LIKELY POPS THU AND THU
NIGHT. PERIODS OF HEAVY RAIN WILL BE POSSIBLE...WITH FORECAST
SOUNDINGS SHOWING PWAT VALUES INCREASING TO AROUND 1.75". DID ADD
ISO TSTM MENTION THU...WITH GFS SHOWING SOME MODEST INSTABILITY
DEVELOPING. MODEL DIFFERENCES CONTINUE WITH JUST HOW QUICKLY THE
FRONT PUSHES THROUGH THE AREA AND DEEPER MOISTURE MOVES OFFSHORE
LATE THU NIGHT AND FRI WITH SW FLOW CONTINUING ALOFT AND THE UPPER
TROF AXIS REMAINING W OF THE REGION. ULTIMATELY IT WILL DEPEND ON
THE TIMING OF AN EMBEDDED SHORTWAVE MOVING THROUGH THE SW FLOW
ALOFT. 00Z MODELS CONTINUE TO TREND SLOWER PUSHING THE FRONT
THROUGH AND DEEPER MOISTURE OFFSHORE AND WILL CONTINUE CHC POPS
FRI MORNING WITH GRADUAL CLEARING FROM THE WEST THROUGH THE
AFTERNOON/EVENING. IT WILL REMAIN MILD AHEAD OF FRONT WITH HIGHS
THU IN THE UPPER 60S TO LOW 70S...AND LOWS THU NIGHT IN THE 50S. A
FEW DEGREES COOLER FOR FRI...THOUGH WILL DEPEND ON HOW QUICKLY THE
FRONT PUSHES THROUGH THE AREA.
FRIDAY NIGHT THROUGH SUNDAY...STRONG CAA DEVELOPS BEHIND THE
FRONT THROUGH MUCH OF THE WEEKEND WITH COLD HIGH PRES BUILDING
INTO THE REGION. STRONGEST NW WINDS EXPECTED TO OCCUR SAT
AFTERNOON THROUGH SAT NIGHT COINCIDENT TO THE UPPER TROUGH AXIS
MOVING ACROSS THE REGION. MUCH COLDER AIRMASS WILL BUILD INTO THE
AREA THIS WEEKEND WITH LOWS FRI NIGHT DROPPING INTO THE 30S
INLAND TO 40S COAST AND SAT NIGHT IN THE 30S WITH BELOW FREEZING
TEMPS EXPECTED INLAND. HIGHS SAT AND SUN IN THE UPPER 40S/50
DEGREES.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH 06Z MONDAY/...
AS OF 715 AM MONDAY...LIGHT SOUTHERLY WINDS AND INCREASED MID/HIGH
CLOUDS HAS HELPED DISSIPATE THE PATCHY FOG AND VFR CONDITIONS
SHOULD PREVAIL FOR THE BALANCE OF THE MORNING. HAVE INCLUDED
VICINITY SHOWERS DURING THE AFTERNOON FOLLOWED BY A PERIOD OF MVFR
CEILINGS BEFORE DOWNSLOPING FLOW AND ADVECTION OF DRIER AIR LEADS
TO RAPID CLEARING TOWARD MORNING ON TUESDAY. S/SW WINDS WILL
INCREASE AND ARE LIKELY TO GUST TO AROUND 20 KNOTS BY THIS
AFTERNOON.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM MON...PRED VFR TUE THRU WED AS HIGH PRES BUILDS INTO
THE AREA...THOUGH LATE NIGHT FOG/STRATUS POSSIBLE WITH LIGHT WINDS
AND GOOD BL MOISTURE. BETTER CHCS OF SUB-VFR WED NIGHT INTO FRI
WITH GOOD CVRG OF SHOWERS EXPECTED AHEAD OF APPROACHING UPR
TRF/SFC COLD FRONT. GRADUALLY IMPROVING CONDITIONS EXPECTED
THROUGH THE DAY FRIDAY AS DEEPER MOISTURE MOVES OFFSHORE.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 715 AM MONDAY...NO REAL CHANGES TO MARINE FORECAST. S/SW
WINDS CONTINUE AT 10 KNOTS OR LESS WITH HIGHER GUSTS AROUND
DIAMOND BUOY. THIS IS DRIVING SEAS OF 2 TO 4 FEET WITH 12-14
SECOND WAVE PERIODS. AS THE COLD FRONT APPROACHES...WINDS WILL
INCREASE TO 20-25 KNOTS OVER THE COASTAL WATERS BY EARLY AFTERNOON
WITH FREQUENT GUSTS TO 25 KNOTS LIKELY ON PAMLICO SOUND THROUGH
TONIGHT. SEAS BUILD TO 5-8 FEET CENTRAL AND NORTHERN WATERS WITH
4-6 FEET SOUTHERN WATERS THIS AFTERNOON THROUGH TONIGHT.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM MON...GUSTY WESTERLY WINDS AND ELEVATED SEAS WILL START
OFF THE PERIOD TUE MORNING. SCA CONDITIONS WILL CONTINUE ACROSS
THE WATERS SOUTH OF OREGON INLET INTO TUESDAY AFTERNOON...GRADUALLY
IMPROVING THROUGH THE DAY AS HIGH PRESSURE BUILDS IN FROM THE
WEST INTO WED. WINDS GRADUALLY DIMINISHING TO BELOW 15 KT TUE
AFTERNOON. SEAS WILL SUBSIDE TO 2 TO 4 FEET LATE TUE AND BY WED
SHLD BE MAINLY AROUND 2 FT. THE NEXT COLD FRONT WILL BE
APPROACHING FROM THE W THU WITH S WINDS INCREASING TO 15 TO 25
KNOTS AND VEERING TO SW THROUGH THE DAY WITH SEAS BUILDING TO 4-8
FT. STRONGEST WINDS AND SEAS EXPECTED ACROSS THE CENTRAL AND
SOUTHERN WATERS WHERE SCA WILL BE LIKELY. A SLIGHT DECREASE IN
WINDS/SEAS EXPECTED THU NIGHT AND FRI AND MAY SEE CONDITIONS
BRIEFLY DROP BELOW SCA CRITERIA. SOME MODEL DIFFERENCES CONTINUE
WITH THE TIMING OF THE FRONTAL PASSAGE FRIDAY BUT EXPECT STRONG
CAA TO DEVELOP BEHIND THE FRONT FRIDAY NIGHT WITH SCA PROBABLE FOR
MOST WATERS FRI NIGHT AND CONTINUING INTO THE WEEKEND.
&&
.CLIMATE...
RECORD MAX TEMPS FOR 12/14 TODAY
LOCATION TEMP/YEAR
NEW BERN 80/1991 (KEWN ASOS)
CAPE HATTERAS 74/1991 (KHSE ASOS)
GREENVILLE 81/1927 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 78/1949 (COOP - NOT KMRH ASOS)
KINSTON 83/1927 (COOP- NOT KISO AWOS)
JACKSONVILLE 80/1991 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 11 AM THIS MORNING TO 1 PM EST
TUESDAY FOR AMZ152-154-156-158.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON TO 7 AM EST
TUESDAY FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...SK/CQD
AVIATION...CTC/CQD
MARINE...CTC/CQD
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS BISMARCK ND
922 AM CST MON DEC 14 2015
.UPDATE...
ISSUED AT 921 AM CST MON DEC 14 2015
THIS UPDATE TO TRIM THE DENSE FOG ADVISORY ACROSS THE JAMES RIVER
VALLEY WEST TO THE MISSOURI RIVER VALLEY. ALSO FAR SOUT5HWEST
NORTH DAKOTA HAVE SEEN VSBYS IMPROVE.
UPDATE ISSUED AT 655 AM CST MON DEC 14 2015
LATEST SENSIBLE WEATHER OBSERVATIONS FROM ACROSS THE REGION SHOW
IMPROVEMENT IN VISIBILITIES. HOWEVER...AREA WEBCAMS ARE STILL
SHOWING SOME FOG. WILL WAIT UNTIL AFTER SUNRISE TO SEE IF WE CAN
CANCEL AT LEAST A PORTION OF THE DENSE FOG ADVISORY.
SOME LIGHT REFLECTIVITIES LIFTING FROM NORTHEAST MONTANA INTO
NORTHWEST NORTH DAKOTA BUT AS OF YET NO GROUND TRUTH TO INDICATE
ANYTHING FALLING FROM THESE MID LEVEL REFLECTIVITIES. DO HAVE SOME
SLIGHT CHANCE POPS STARTING HERE THIS AFTERNOON...AND WILL LEAVE
THE MENTION OUT THIS MORNING FOR NOW.
OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 14 2015
HIGHLIGHTS IN THE SHORT TERM INCLUDE: THE CURRENT DENSE FOG ADVISORY
VALID THROUGH THIS MORNING...THE ISSUANCE OF A WINTER STORM WATCH
FAR SOUTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA INCLUDING THE JAMES
RIVER VALLEY TUESDAY THROUGH WEDNESDAY.
THE LATEST SUITE OF SATELLITE IMAGERY ALONG WITH SURFACE
OBSERVATIONS/WEBCAMS STILL SIGNAL THE NEED FOR A DENSE FOG ADVISORY.
THERE AS BEEN SOME IMPROVEMENT IN THE JAMES RIVER VALLEY WITH
VISIBILITIES BETWEEN 1 AND 3 MILES DUE TO A SHIELD OF THICK MID/HIGH
CLOUDS SHIFTING FROM EAST TO WEST INTO THIS AREA. HOWEVER
EXPECTATIONS PER LATEST HRRR IS THAT THIS AREA WILL FILL IN AGAIN
TOWARD 12Z. WITH THAT IN MIND...WILL LET THE DENSE FOG ADVISORY IN
THE JAMES RIVER VALLEY RIDE FOR NOW AND GIVE IT ANOTHER LOOK DURING
THE 6AM-7AM FORECAST UPDATE. OTHERWISE...EXPECT CLOUDS TO LIFT A
COUPLE HUNDRED FEET THIS AFTERNOON FROM CURRENT LEVELS AS VISIBILITIES
SLOWLY IMPROVE...BUT REMAINING CLOUDY THROUGH THE SHORT TERM WITH
AREAS OF FOG AGAIN TONIGHT.
WATER VAPOR IMAGERY SHOWS OUR NEXT UPPER LOW SHIFTING INTO NORTHERN
NEVADA EARLY THIS MORNING...AND WILL TRANSLATE EAST INTO COLORADO
TONIGHT BEFORE EJECTING NORTHEAST INTO SOUTHERN MINNESOTA BY 12Z
WEDNESDAY. AHEAD OF THIS UPPER LOW...PERSISTENT LOW CLOUDS/FOG AND
AN INCREASE IN VERTICAL MOTION WITHIN THE SATURATED LAYER/-10C AND
WARMER...WILL LEAD TO A SLIGHT CHANCE OF VERY LIGHT FREEZING DRIZZLE
AND/OR VERY LIGHT SNOW ACROSS CENTRAL NORTH DAKOTA. THIS WAS
MENTIONED IN THE PREVIOUS FORECASTS AND BUFKIT SOUNDINGS CONTINUE
WITH THIS IDEA.
AFTER A SNOW COLLABORATION CALL WITH WPC WWD AND SURROUNDING
OFFICES...WE DECIDED ON A WINTER STORM WATCH FAR SOUTHWEST INTO
SOUTH CENTRAL NORTH DAKOTA. UNLESS THERE IS A CHANGE WITH THE
OVERALL TRACK RESULTING IN AN INCREASE OF SNOWFALL TOTALS BY ONE OR
TWO INCHES...THEN THE LIKELY SCENARIO WILL BE FOR THE EXISTING
WINTER STORM WATCH TO BE CONVERTED INTO A WINTER WEATHER ADVISORY
ADVERTISING 3 TO 6 INCH SNOWFALL TOTALS. GIVEN WE ARE STILL ABOUT
36HRS OUT AND THERE REMAINS ENOUGH UNCERTAINTY WITHIN THE WATCH AREA
FOR AT LEAST A 50 PERCENT CHANCE OR GREATER OF MEETING WARNING
CRITERIA/6 INCHES OR MORE...IT MADE MORE SENSE AT THIS STAGE TO
ISSUE A WINTER STORM WATCH AND THEN BEGIN CHISELING AWAY DURING THE
DAY TODAY INTO TONIGHT FOR THE EXACT DETAILS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 14 2015
THE MAIN FORECAST HIGHLIGHT IN THE EXTENDED PERIOD CONTINUES TO BE
THE DEVELOPING UPPER LEVEL TROUGH CURRENTLY OVER THE WESTERN U.S.
AND RESULTING SURFACE CYCLONE THAT DEVELOPS OVER THE CENTRAL ROCKIES
AND TRACKS NORTHEAST INTO THE UPPER GREAT LAKES TUESDAY THROUGH
WEDNESDAY.
DETERMINISTIC MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH THE
EVOLUTION OF THE MASS FIELDS WITH THIS SYSTEM. AFTER COORDINATION
WITH WPC...A ECMWF/GFS BLEND WAS UTILIZED FOR TIMING/PLACEMENT OF
FEATURES AND QPF FORECAST.
SEE THE SHORT TERM DISCUSSION FOR A DETAILED REASONING FOR
HIGHLIGHTS WITH THIS SYSTEM.
WE BEGIN THE EXTENDED PERIOD ON TUESDAY AS THE SURFACE LOW IS JUST
EJECTING INTO THE CENTRAL PLAINS. ALTHOUGH THE MAIN ENERGY IS
CONFINED TO THE SOUTHERN PORTION OF THE UPPER LEVEL TROUGH...THERE
REMAINS SOME ENERGY IN THE NORTHERN STREAM AND FORCING ASSOCIATED
WITH THIS ENERGY IS ABLE TO OVERCOME THE INITIAL DRY UPPER LEVELS IN
THE FAR WEST WITH SNOW BEGINNING TUESDAY MORNING. DURING THE DAY
TUESDAY THE ENERGY TRANSITIONS SOUTHEAST TOWARD THE SOUTHERN SYSTEM.
THUS IT LOOKS LIKE THE FAR SOUTHWEST COULD SEE A PERIOD OF SNOW
BEGINNING TUESDAY AND CONTINUING THROUGH TUESDAY NIGHT. THINK
ACCUMULATIONS ARE GENERALLY GOING TO BE LESS THAN 3 INCHES...BUT THE
FAR SOUTHWEST...WITH SOME ENHANCED UPSLOPE FLOW COULD SEE SOME
ADDITIONAL ACCUMULATION...PUSHING TOTALS MORE INTO THE 4-6 INCH
RANGE. THUS THE REASON FOR THE WATCH IN THE FAR SOUTHWEST. FARTHER
EAST...SNOW IS NOT EXPECTED TO GET UNDER WAY UNTIL THE AFTERNOON OR
EVENING. HOWEVER...WITH OUR SATURATED NEAR SURFACE LAYER...AND SOME
OMEGA LOCATED IN THIS LAYER...WILL CONTINUE TO ADVERTISE A MENTION
OF FREEZING DRIZZLE DURING THE DAY TUESDAY.
THE MAIN FORCING WITH THE CYCLONE WILL OCCUR TUESDAY NIGHT. STARTING
IN THE FAR SOUTH CENTRAL POSSIBLY LATE AFTERNOON TUESDAY...BUT FOR
THE MOST PART TUESDAY EVENING. AND LIFTING NORTH NORTHEAST ACROSS
MAINLY THE EASTERN PORTION OF CENTRAL NORTH DAKOTA THROUGH THE
NIGHT. ON WEDNESDAY...THE MAIN SURFACE LOW LIFTS FROM SOUTHERN
MINNESOTA TO NEAR LAKE SUPERIOR...BUT TRAILING DEFORMATION ZONE
TRACKS SLOWLY EAST ACROSS CENTRAL NORTH DAKOTA...KEEPING THE THREAT
OF ACCUMULATING SNOW OVER CENTRAL NORTH DAKOTA THROUGH THE DAY
WEDNESDAY. ALTHOUGH WE DO EXPECT ACCUMULATING SNOW TO TAPER OFF
FROM WEST TO EAST DURING THE DAY. WINDS WITH THIS SYSTEM ARE NOT
EXPECTED TO BE TERRIBLY STRONG...MAINLY 10 TO 20 MPH DURING THE
PEAK ACCUMULATION PERIOD OF TUESDAY NIGHT...BUT INCREASING TO THE
15 TO 25 MPH RANGE ON WEDNESDAY. THUS...WE COULD SEE SOME BLOWING
AND DRIFTING ON WEDNESDAY...BUT NOT EXPECTING A SIGNIFICANT
PROBLEM WITH BLOWING AND DRIFTING SNOW.
BEYOND THE TUESDAY-WEDNESDAY SYSTEM...COLD AIR GETS PULLED INTO THE
REGION...BRINGING A COOLING TREND WITH HIGHS IN THE 10 TO 20 ABOVE
RANGE AND LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO AS WE MOVE
TO THE END OF THE WORK WEEK. THEN A BUILDING WESTERN RIDGE SHOULD
BRING MODERATING TEMPERATURES BY THE END OF THE WEEKEND.
LITTLE SIGNIFICANT PRECIPITATION IS EXPECTED BEYOND WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 655 AM CST MON DEC 14 2015
ALL TERMINALS WILL CONTINUE TO EXPERIENCE A COMBINATION OF
LIFR/VLIFR CIGS...AND VSBYS RANGING BETWEEN MVFR TO VLIFR THROUGH
18Z MONDAY.
A DENSE FOG ADVISORY REMAINS IN EFFECT WHICH COVERS ALL TERMINALS
EXCEPT KISN THROUGH 17Z. PATCHY LIGHT FREEZING DRIZZLE POSSIBLE AT
ANYTIME WITH THE STRATUS AND FOG DECK IN PLACE. CIGS/VSBYS WILL
IMPROVE SOMEWHAT AT MOST TERMINALS AFTER 18Z MONDAY...HOWEVER IFR
CIGS EXPECTED THROUGH THE TAF PERIOD WITH AREAS OF FOG RETURNING
AFTER 00Z TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST /10 AM MST/ THIS MORNING FOR
NDZ003>005-011>013-019>023-033-034-041-042-044-045.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR NDZ013-020-022-023-025-034>037-042-045>048-050-051.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR NDZ043-044.
&&
$$
UPDATE...WAA
SHORT TERM...KS
LONG TERM...TWH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
732 AM CST MON DEC 14 2015
.UPDATE...
ISSUED AT 655 AM CST MON DEC 14 2015
LATEST SENSIBLE WEATHER OBSERVATIONS FROM ACROSS THE REGION SHOW
IMPROVEMENT IN VISIBILITIES. HOWEVER...AREA WEBCAMS ARE STILL
SHOWING SOME FOG. WILL WAIT UNTIL AFTER SUNRISE TO SEE IF WE CAN
CANCEL AT LEAST A PORTION OF THE DENSE FOG ADVISORY.
SOME LIGHT REFLECTIVITIES LIFTING FROM NORTHEAST MONTANA INTO
NORTHWEST NORTH DAKOTA BUT AS OF YET NO GROUND TRUTH TO INDICATE
ANYTHING FALLING FROM THESE MID LEVEL REFLECTIVITIES. DO HAVE SOME
SLIGHT CHANCE POPS STARTING HERE THIS AFTERNOON...AND WILL LEAVE
THE MENTION OUT THIS MORNING FOR NOW.
OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 14 2015
HIGHLIGHTS IN THE SHORT TERM INCLUDE: THE CURRENT DENSE FOG ADVISORY
VALID THROUGH THIS MORNING...THE ISSUANCE OF A WINTER STORM WATCH
FAR SOUTHWEST THROUGH SOUTH CENTRAL NORTH DAKOTA INCLUDING THE JAMES
RIVER VALLEY TUESDAY THROUGH WEDNESDAY.
THE LATEST SUITE OF SATELLITE IMAGERY ALONG WITH SURFACE
OBSERVATIONS/WEBCAMS STILL SIGNAL THE NEED FOR A DENSE FOG ADVISORY.
THERE AS BEEN SOME IMPROVEMENT IN THE JAMES RIVER VALLEY WITH
VISIBILITIES BETWEEN 1 AND 3 MILES DUE TO A SHIELD OF THICK MID/HIGH
CLOUDS SHIFTING FROM EAST TO WEST INTO THIS AREA. HOWEVER
EXPECTATIONS PER LATEST HRRR IS THAT THIS AREA WILL FILL IN AGAIN
TOWARD 12Z. WITH THAT IN MIND...WILL LET THE DENSE FOG ADVISORY IN
THE JAMES RIVER VALLEY RIDE FOR NOW AND GIVE IT ANOTHER LOOK DURING
THE 6AM-7AM FORECAST UPDATE. OTHERWISE...EXPECT CLOUDS TO LIFT A
COUPLE HUNDRED FEET THIS AFTERNOON FROM CURRENT LEVELS AS VISIBILITIES
SLOWLY IMPROVE...BUT REMAINING CLOUDY THROUGH THE SHORT TERM WITH
AREAS OF FOG AGAIN TONIGHT.
WATER VAPOR IMAGERY SHOWS OUR NEXT UPPER LOW SHIFTING INTO NORTHERN
NEVADA EARLY THIS MORNING...AND WILL TRANSLATE EAST INTO COLORADO
TONIGHT BEFORE EJECTING NORTHEAST INTO SOUTHERN MINNESOTA BY 12Z
WEDNESDAY. AHEAD OF THIS UPPER LOW...PERSISTENT LOW CLOUDS/FOG AND
AN INCREASE IN VERTICAL MOTION WITHIN THE SATURATED LAYER/-10C AND
WARMER...WILL LEAD TO A SLIGHT CHANCE OF VERY LIGHT FREEZING DRIZZLE
AND/OR VERY LIGHT SNOW ACROSS CENTRAL NORTH DAKOTA. THIS WAS
MENTIONED IN THE PREVIOUS FORECASTS AND BUFKIT SOUNDINGS CONTINUE
WITH THIS IDEA.
AFTER A SNOW COLLABORATION CALL WITH WPC WWD AND SURROUNDING
OFFICES...WE DECIDED ON A WINTER STORM WATCH FAR SOUTHWEST INTO
SOUTH CENTRAL NORTH DAKOTA. UNLESS THERE IS A CHANGE WITH THE
OVERALL TRACK RESULTING IN AN INCREASE OF SNOWFALL TOTALS BY ONE OR
TWO INCHES...THEN THE LIKELY SCENARIO WILL BE FOR THE EXISTING
WINTER STORM WATCH TO BE CONVERTED INTO A WINTER WEATHER ADVISORY
ADVERTISING 3 TO 6 INCH SNOWFALL TOTALS. GIVEN WE ARE STILL ABOUT
36HRS OUT AND THERE REMAINS ENOUGH UNCERTAINTY WITHIN THE WATCH AREA
FOR AT LEAST A 50 PERCENT CHANCE OR GREATER OF MEETING WARNING
CRITERIA/6 INCHES OR MORE...IT MADE MORE SENSE AT THIS STAGE TO
ISSUE A WINTER STORM WATCH AND THEN BEGIN CHISELING AWAY DURING THE
DAY TODAY INTO TONIGHT FOR THE EXACT DETAILS.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 14 2015
THE MAIN FORECAST HIGHLIGHT IN THE EXTENDED PERIOD CONTINUES TO BE
THE DEVELOPING UPPER LEVEL TROUGH CURRENTLY OVER THE WESTERN U.S.
AND RESULTING SURFACE CYCLONE THAT DEVELOPS OVER THE CENTRAL ROCKIES
AND TRACKS NORTHEAST INTO THE UPPER GREAT LAKES TUESDAY THROUGH
WEDNESDAY.
DETERMINISTIC MODELS HAVE COME INTO PRETTY GOOD AGREEMENT WITH THE
EVOLUTION OF THE MASS FIELDS WITH THIS SYSTEM. AFTER COORDINATION
WITH WPC...A ECMWF/GFS BLEND WAS UTILIZED FOR TIMING/PLACEMENT OF
FEATURES AND QPF FORECAST.
SEE THE SHORT TERM DISCUSSION FOR A DETAILED REASONING FOR
HIGHLIGHTS WITH THIS SYSTEM.
WE BEGIN THE EXTENDED PERIOD ON TUESDAY AS THE SURFACE LOW IS JUST
EJECTING INTO THE CENTRAL PLAINS. ALTHOUGH THE MAIN ENERGY IS
CONFINED TO THE SOUTHERN PORTION OF THE UPPER LEVEL TROUGH...THERE
REMAINS SOME ENERGY IN THE NORTHERN STREAM AND FORCING ASSOCIATED
WITH THIS ENERGY IS ABLE TO OVERCOME THE INITIAL DRY UPPER LEVELS IN
THE FAR WEST WITH SNOW BEGINNING TUESDAY MORNING. DURING THE DAY
TUESDAY THE ENERGY TRANSITIONS SOUTHEAST TOWARD THE SOUTHERN SYSTEM.
THUS IT LOOKS LIKE THE FAR SOUTHWEST COULD SEE A PERIOD OF SNOW
BEGINNING TUESDAY AND CONTINUING THROUGH TUESDAY NIGHT. THINK
ACCUMULATIONS ARE GENERALLY GOING TO BE LESS THAN 3 INCHES...BUT THE
FAR SOUTHWEST...WITH SOME ENHANCED UPSLOPE FLOW COULD SEE SOME
ADDITIONAL ACCUMULATION...PUSHING TOTALS MORE INTO THE 4-6 INCH
RANGE. THUS THE REASON FOR THE WATCH IN THE FAR SOUTHWEST. FARTHER
EAST...SNOW IS NOT EXPECTED TO GET UNDER WAY UNTIL THE AFTERNOON OR
EVENING. HOWEVER...WITH OUR SATURATED NEAR SURFACE LAYER...AND SOME
OMEGA LOCATED IN THIS LAYER...WILL CONTINUE TO ADVERTISE A MENTION
OF FREEZING DRIZZLE DURING THE DAY TUESDAY.
THE MAIN FORCING WITH THE CYCLONE WILL OCCUR TUESDAY NIGHT. STARTING
IN THE FAR SOUTH CENTRAL POSSIBLY LATE AFTERNOON TUESDAY...BUT FOR
THE MOST PART TUESDAY EVENING. AND LIFTING NORTH NORTHEAST ACROSS
MAINLY THE EASTERN PORTION OF CENTRAL NORTH DAKOTA THROUGH THE
NIGHT. ON WEDNESDAY...THE MAIN SURFACE LOW LIFTS FROM SOUTHERN
MINNESOTA TO NEAR LAKE SUPERIOR...BUT TRAILING DEFORMATION ZONE
TRACKS SLOWLY EAST ACROSS CENTRAL NORTH DAKOTA...KEEPING THE THREAT
OF ACCUMULATING SNOW OVER CENTRAL NORTH DAKOTA THROUGH THE DAY
WEDNESDAY. ALTHOUGH WE DO EXPECT ACCUMULATING SNOW TO TAPER OFF
FROM WEST TO EAST DURING THE DAY. WINDS WITH THIS SYSTEM ARE NOT
EXPECTED TO BE TERRIBLY STRONG...MAINLY 10 TO 20 MPH DURING THE
PEAK ACCUMULATION PERIOD OF TUESDAY NIGHT...BUT INCREASING TO THE
15 TO 25 MPH RANGE ON WEDNESDAY. THUS...WE COULD SEE SOME BLOWING
AND DRIFTING ON WEDNESDAY...BUT NOT EXPECTING A SIGNIFICANT
PROBLEM WITH BLOWING AND DRIFTING SNOW.
BEYOND THE TUESDAY-WEDNESDAY SYSTEM...COLD AIR GETS PULLED INTO THE
REGION...BRINGING A COOLING TREND WITH HIGHS IN THE 10 TO 20 ABOVE
RANGE AND LOWS IN THE SINGLE DIGITS ABOVE AND BELOW ZERO AS WE MOVE
TO THE END OF THE WORK WEEK. THEN A BUILDING WESTERN RIDGE SHOULD
BRING MODERATING TEMPERATURES BY THE END OF THE WEEKEND.
LITTLE SIGNIFICANT PRECIPITATION IS EXPECTED BEYOND WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 655 AM CST MON DEC 14 2015
ALL TERMINALS WILL CONTINUE TO EXPERIENCE A COMBINATION OF
LIFR/VLIFR CIGS...AND VSBYS RANGING BETWEEN MVFR TO VLIFR THROUGH
18Z MONDAY.
A DENSE FOG ADVISORY REMAINS IN EFFECT WHICH COVERS ALL TERMINALS
EXCEPT KISN THROUGH 17Z. PATCHY LIGHT FREEZING DRIZZLE POSSIBLE AT
ANYTIME WITH THE STRATUS AND FOG DECK IN PLACE. CIGS/VSBYS WILL
IMPROVE SOMEWHAT AT MOST TERMINALS AFTER 18Z MONDAY...HOWEVER IFR
CIGS EXPECTED THROUGH THE TAF PERIOD WITH AREAS OF FOG RETURNING
AFTER 00Z TUESDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 11 AM CST /10 AM MST/ THIS MORNING FOR
NDZ003>005-010>013-018>023-025-031>037-040>048-050-051.
WINTER STORM WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
AFTERNOON FOR NDZ013-020-022-023-025-034>037-042-045>048-050-051.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH WEDNESDAY MORNING
FOR NDZ043-044.
&&
$$
UPDATE...TWH
SHORT TERM...KS
LONG TERM...TWH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
627 AM EST MON DEC 14 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY AS DEEP LOW
PRESSURE MOVES ACROSS THE CENTRAL GREAT LAKES. HIGH PRESSURE WILL
BUILD OVER THE AREA FROM THE SOUTH TUESDAY INTO WEDNESDAY. ANOTHER
COLD FRONT IS EXPECTED TO CROSS THE REGION ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SLOWED PRECIP MOVEMENT SLIGHTLY. ALSO NEAR TERM HOURLY
TEMPS.
ORIGINAL...DEEP LOW PRESSURE OVER IOWA AT 12Z TODAY WILL CONTINUE
ENE ACROSS THE CENTRAL GREAT LAKES. A COLD FRONT ASSOCIATED WITH
THE LOW WILL MOVE EAST ACROSS THE AREA TODAY REACHING KCLE BY
ABOUT 18Z AND EAST OF THE AREA BY 22Z. NAM12 AND HRRR SHOW RAIN
MOVING INTO THE WESTERN COUNTIES AROUND 12Z...SPREADING EAST
ACROSS THE AREA THROUGH THE MORNING AND REACHING INTO NWRN PA
AROUND NOON. WILL CONTINUE WITH CAT POPS FOR THE REGION TODAY.
850MB JET INCREASES TO ABOUT 60 KNOTS AROUND 12Z FALLING SLOWLY
THROUGH THE DAY. WINDS SHOULD GET GUSTY LATE MORNING AND AFTERNOON
IN THE COLD ADVECTION. EXPECTING GUSTS INTO THE 30 TO 40 KNOT
RANGE BUT SHOULD REMAIN BELOW ADVISORY CRITERIA. HIGHS IN THE 60S
WITH FALLING TEMPS WEST HALF MID/LATE AFTERNOON.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
THE COLD FRONT WILL BE EAST OF THE AREA BY 00Z WHILE THE LOW WILL
BE CENTERED ACROSS THE CENTRAL GREAT LAKES. MAIN CONCERN FOR THE
EVENING HOURS WILL BE WRAP AROUND MOISTURE SUPPORTING LIGHT RAIN
ACROSS THE AREA BEFORE THE SYSTEM PULLS NORTHEAST. WILL BEGIN THE
EVENING WITH CHANCE POPS FOR LIGHT RAIN MOST AREAS AND LIKELY POPS
NORTHEAST. BY 12Z TUESDAY BEST MOISTURE WILL BE WELL NORTHEAST
HOWEVER THE CORE OF THE COOL AIR WILL BE ACROSS THE AREA WITH
850MB TEMPS AROUND 0C WHICH WILL NOT BE LOW ENOUGH FOR LAKE EFFECT
SO WILL BEGIN WITH ONLY A SLIGHT CHANCE IN THE GRAPHICS AND TAPER
TO NO POPS BY 18Z. HIGH PRESSURE WILL CROSS THE AREA TUESDAY NIGHT
INTO WEDNESDAY. WILL CONTINUE WITH A DRY FORECAST THROUGH
WEDNESDAY EXCEPT FOR A SMALL CHANCE FAR NORTHWEST WEDNESDAY
AFTERNOON. WEDNESDAY AFTERNOON MODELS SHOW ANOTHER COLD FRONT ON
OUR DOORSTEP...ASSOCIATED WITH LOW PRESSURE MOVING NORTHEAST
THROUGH MINNESOTA. WHILE THERE IS NOT A LOT OF MOISTURE WITH THE
FRONT...MODELS SHOW A SIGNIFICANT TEMP DROP...BACK TO NEAR
NORMAL...WITH 850MB TEMPS DROPPING TO -6 TO -8C BY FRIDAY 00Z.
WILL HAVE CHANCE POPS FOR RAIN WEDNESDAY NIGHT DRYING OUT WEST FOR
THURSDAY. WILL CONTINUE CHANCE POPS EAST THROUGH THURSDAY AS MORE
MOISTURE GETS PULLED NORTH INTO THE SYSTEM. WILL TRANSITION TO
LAKE EFFECT RAIN/SNOW THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN TRENDING TOWARD A WINTER TREND FOR A SHORT
PERIOD AS A DEEP DIGGING UPPER LEVEL TROUGH DIGS INTO THE EASTERN
UNITED STATES BY WEEKS END. THE TROUGH WILL SHIFT OFF THE EAST COAST
BY THE END OF THE WEEKEND AS MASSIVE UPPER LEVEL RIDGE BEGINS TO
BUILD BACK INTO THE AREA FROM THE WEST. THIS WILL KEEP THE TREND OF
MILD TEMPERATURES ONCE WE HEAD INTO THE WEEKEND. TEMPERATURES ARE
EXPECTED TO QUICKLY RECOVER INTO EARLY NEXT WEEK.
IN THE MEAN TIME...COLD FRONT IS PROGGED TO MOVE EAST ACROSS THE
AREA THURSDAY. THIS WILL BEGIN THE INFLUX OF COOLER AIR. BUT THE
TRUE COLD AIR REALLY DOES NOT ARRIVE UNTIL FRIDAY MORNING. AT THIS
TIME...I ANTICIPATE THE HIGH TEMPERATURE WILL PROBABLY OCCUR DURING
THE MORNING HOURS AND TEMPERATURES WILL BEGIN TO FALL SLOWLY THROUGH
THE DAY INTO FRIDAY NIGHT. LOOKING AT TEMPERATURES IN THE LOWER 30S
FOR HIGHS FRIDAY. FLOW BEGINS TO BECOME WELL ALIGNED FRIDAY INTO
SATURDAY AND DEEP MOISTURE IS EXPECTED TO REMAIN PRESENT DURING THIS
TIME PERIOD ALONG WITH UPPER LEVEL POSITIVE VORTICITY ADVECTION AND
COLD AIR ADVECTION. THIS SHOULD GET THE LAKE SNOW MACHINE GOING OVER
NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY THROUGH SATURDAY.
DUE TO THE SYNOPTIC MOISTURE BEING PRESENT...SNOW SHOWERS ARE
EXPECTED FRIDAY NIGHT BUT THE BEST CHANCE WILL BE IN THE EAST.
COLD AIR ADVECTION WILL BE IN EARNEST FRIDAY NIGHT AND WILL LIKELY
BRING TEMPERATURES DOWN INTO THE 20S FOR LOWS. SOME RECOVERY WILL
TRY TO TAKE PLACE SATURDAY AS MID LEVEL TEMPERATURES BEGIN TO WARM
DURING THE DAY. EVENTUALLY BY SATURDAY NIGHT FLOW SHIFTS AWAY FROM
THE LAKE AND SHOULD BRING AN END TO THE LAKE EFFECT SNOW SHOWERS.
OTHERWISE...IT WILL BE FAIR OVER THE REST OF THE FORECAST AREA. FAIR
WEATHER AND TEMPERATURES BACK INTO THE UPPER 30S EXPECTED FOR SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A COLD FRONT WILL MOVE EAST ACROSS THE AREA TODAY. WINDS ARE
EXPECTED TO SHIFT TO A SOUTHWESTERLY DIRECTION AFTER THE PASSAGE
OF THE FRONT. SHOWERS ASSOCIATED WITH THE FRONT COULD CAUSE SOME
BRIEF WIND GUSTS TO 35 KNOTS AT TOLEDO AND FINDLAY.
OTHERWISE...SHOWERS CAN BE EXPECTED ALL AREAS AS THE DAY
PROGRESSES. CEILINGS WILL BE DROPPING WITH TIME THROUGH THE DAY TO
MVFR AND POSSIBLY IFR. EXPECTING VCSH SHOWERS TOWARD THE END OF
THE PERIOD.
OUTLOOK...NON VFR LINGERING INTO TUESDAY ACROSS NORTHEAST OH AND
NORTHWEST PA. NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA. NON VFR NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY IN
LAKE EFFECT SNOW.
&&
.MARINE...
WINDS WILL INCREASE DURING THE DAY TODAY ON THE LAKE BUT
NOT EXPECTING THEM TO GO ABOVE GALES. WINDS WILL REMAIN MOSTLY
SOUTHERLY TODAY AND KEEP THE STRONGEST WINDS AND HIGHEST WAVES
OUTSIDE THE 5 NM NEARSHORE WATERS. ONCE WINDS BECOME MORE
WESTERLY...EXPECTING SMALL CRAFT CONDITIONS TO DEVELOP AROUND 5 PM
THIS AFTERNOON AND LAST UNTIL AROUND 4 PM TOMORROW AFTERNOON. SO
WILL GO AHEAD AND HOIST THE SMALL CRAFT FOR THIS TIME PERIOD.
OTHERWISE...WINDS DIMINISH FAIRLY QUICKLY TOMORROW EVENING AND
REMAIN FAIRLY LIGHT THROUGH THURSDAY MORNING. THEN...AS A COLD
FRONT MOVES EAST...WINDS WILL INCREASE AGAIN THURSDAY THROUGH
FRIDAY AND POSSIBLY CAUSE SMALL CRAFT ADVISORIES TO BE ISSUED ONCE
AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...LOMBARDY
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
611 AM EST MON DEC 14 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION TODAY AS DEEP LOW
PRESSURE MOVES ACROSS THE CENTRAL GREAT LAKES. HIGH PRESSURE WILL
BUILD OVER THE AREA FROM THE SOUTH TUESDAY INTO WEDNESDAY. ANOTHER
COLD FRONT IS EXPECTED TO CROSS THE REGION ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...SLOWED PRECIP MOVEMENT SLIGHTLY. ALSO NEAR TERM HOURLY
TEMPS.
ORIGINAL...DEEP LOW PRESSURE OVER IOWA AT 12Z TODAY WILL CONTINUE
ENE ACROSS THE CENTRAL GREAT LAKES. A COLD FRONT ASSOCIATED WITH
THE LOW WILL MOVE EAST ACROSS THE AREA TODAY REACHING KCLE BY
ABOUT 18Z AND EAST OF THE AREA BY 22Z. NAM12 AND HRRR SHOW RAIN
MOVING INTO THE WESTERN COUNTIES AROUND 12Z...SPREADING EAST
ACROSS THE AREA THROUGH THE MORNING AND REACHING INTO NWRN PA
AROUND NOON. WILL CONTINUE WITH CAT POPS FOR THE REGION TODAY.
850MB JET INCREASES TO ABOUT 60 KNOTS AROUND 12Z FALLING SLOWLY
THROUGH THE DAY. WINDS SHOULD GET GUSTY LATE MORNING AND AFTERNOON
IN THE COLD ADVECTION. EXPECTING GUSTS INTO THE 30 TO 40 KNOT
RANGE BUT SHOULD REMAIN BELOW ADVISORY CRITERIA. HIGHS IN THE 60S
WITH FALLING TEMPS WEST HALF MID/LATE AFTERNOON.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY NIGHT/...
THE COLD FRONT WILL BE EAST OF THE AREA BY 00Z WHILE THE LOW WILL
BE CENTERED ACROSS THE CENTRAL GREAT LAKES. MAIN CONCERN FOR THE
EVENING HOURS WILL BE WRAP AROUND MOISTURE SUPPORTING LIGHT RAIN
ACROSS THE AREA BEFORE THE SYSTEM PULLS NORTHEAST. WILL BEGIN THE
EVENING WITH CHANCE POPS FOR LIGHT RAIN MOST AREAS AND LIKELY POPS
NORTHEAST. BY 12Z TUESDAY BEST MOISTURE WILL BE WELL NORTHEAST
HOWEVER THE CORE OF THE COOL AIR WILL BE ACROSS THE AREA WITH
850MB TEMPS AROUND 0C WHICH WILL NOT BE LOW ENOUGH FOR LAKE EFFECT
SO WILL BEGIN WITH ONLY A SLIGHT CHANCE IN THE GRAPHICS AND TAPER
TO NO POPS BY 18Z. HIGH PRESSURE WILL CROSS THE AREA TUESDAY NIGHT
INTO WEDNESDAY. WILL CONTINUE WITH A DRY FORECAST THROUGH
WEDNESDAY EXCEPT FOR A SMALL CHANCE FAR NORTHWEST WEDNESDAY
AFTERNOON. WEDNESDAY AFTERNOON MODELS SHOW ANOTHER COLD FRONT ON
OUR DOORSTEP...ASSOCIATED WITH LOW PRESSURE MOVING NORTHEAST
THROUGH MINNESOTA. WHILE THERE IS NOT A LOT OF MOISTURE WITH THE
FRONT...MODELS SHOW A SIGNIFICANT TEMP DROP...BACK TO NEAR
NORMAL...WITH 850MB TEMPS DROPPING TO -6 TO -8C BY FRIDAY 00Z.
WILL HAVE CHANCE POPS FOR RAIN WEDNESDAY NIGHT DRYING OUT WEST FOR
THURSDAY. WILL CONTINUE CHANCE POPS EAST THROUGH THURSDAY AS MORE
MOISTURE GETS PULLED NORTH INTO THE SYSTEM. WILL TRANSITION TO
LAKE EFFECT RAIN/SNOW THURSDAY NIGHT.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
UPPER LEVEL PATTERN TRENDING TOWARD A WINTER TREND FOR A SHORT
PERIOD AS A DEEP DIGGING UPPER LEVEL TROUGH DIGS INTO THE EASTERN
UNITED STATES BY WEEKS END. THE TROUGH WILL SHIFT OFF THE EAST COAST
BY THE END OF THE WEEKEND AS MASSIVE UPPER LEVEL RIDGE BEGINS TO
BUILD BACK INTO THE AREA FROM THE WEST. THIS WILL KEEP THE TREND OF
MILD TEMPERATURES ONCE WE HEAD INTO THE WEEKEND. TEMPERATURES ARE
EXPECTED TO QUICKLY RECOVER INTO EARLY NEXT WEEK.
IN THE MEAN TIME...COLD FRONT IS PROGGED TO MOVE EAST ACROSS THE
AREA THURSDAY. THIS WILL BEGIN THE INFLUX OF COOLER AIR. BUT THE
TRUE COLD AIR REALLY DOES NOT ARRIVE UNTIL FRIDAY MORNING. AT THIS
TIME...I ANTICIPATE THE HIGH TEMPERATURE WILL PROBABLY OCCUR DURING
THE MORNING HOURS AND TEMPERATURES WILL BEGIN TO FALL SLOWLY THROUGH
THE DAY INTO FRIDAY NIGHT. LOOKING AT TEMPERATURES IN THE LOWER 30S
FOR HIGHS FRIDAY. FLOW BEGINS TO BECOME WELL ALIGNED FRIDAY INTO
SATURDAY AND DEEP MOISTURE IS EXPECTED TO REMAIN PRESENT DURING THIS
TIME PERIOD ALONG WITH UPPER LEVEL POSITIVE VORTICITY ADVECTION AND
COLD AIR ADVECTION. THIS SHOULD GET THE LAKE SNOW MACHINE GOING OVER
NORTHEAST OHIO AND NORTHWEST PENNSYLVANIA FRIDAY THROUGH SATURDAY.
DUE TO THE SYNOPTIC MOISTURE BEING PRESENT...SNOW SHOWERS ARE
EXPECTED FRIDAY NIGHT BUT THE BEST CHANCE WILL BE IN THE EAST.
COLD AIR ADVECTION WILL BE IN EARNEST FRIDAY NIGHT AND WILL LIKELY
BRING TEMPERATURES DOWN INTO THE 20S FOR LOWS. SOME RECOVERY WILL
TRY TO TAKE PLACE SATURDAY AS MID LEVEL TEMPERATURES BEGIN TO WARM
DURING THE DAY. EVENTUALLY BY SATURDAY NIGHT FLOW SHIFTS AWAY FROM
THE LAKE AND SHOULD BRING AN END TO THE LAKE EFFECT SNOW SHOWERS.
OTHERWISE...IT WILL BE FAIR OVER THE REST OF THE FORECAST AREA. FAIR
WEATHER AND TEMPERATURES BACK INTO THE UPPER 30S EXPECTED FOR SUNDAY.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
A STRONG LOW PRESSURE SYSTEM WILL MOVE OUT OF THE PLAINS ACROSS
THE UPPER GREAT LAKES BRINGING SHOWERS AND INCREASING WINDS ON
MONDAY. VFR CONDITIONS EXPECTED THROUGH AT LEAST 12Z THEN LOWER
CEILINGS/VSBYS ARRIVING WITH A BAND OF RAIN ALONG A COLD FRONT
SWEEPING WEST TO EAST. RAIN WILL SPREAD INTO TOL/FDY BETWEEN 12-
14Z...CLE TOWARDS 16Z AND ERI BY 18Z. RAIN WILL GENERALLY LAST 2
HOURS OR LESS AT MOST SITES AND CONDITIONS WILL PRIMARILY BE MVFR
BUT BRIEF IFR IS POSSIBLE. A 50 KNOT LOW LEVEL JET NEAR 2500 FEET
WILL SPREAD INTO NORTHERN OHIO BETWEEN 08-15Z. INCLUDED THE WIND
SHEER WHERE SURFACE WINDS WERE LOW ENOUGH TO WARRANT IT...THEN
REMOVED THE MENTION AS SURFACE WINDS BECOME GUSTY AHEAD OF THE
FRONT. WINDS WILL SHIFT TO SOUTHWEST AND INCREASE BEHIND THE FRONT
DURING THE AFTERNOON. GUSTS OF 25 TO 30 KNOTS WILL BE COMMON WITH
LOCALLY STRONGER GUSTS IN NW OHIO.
OUTLOOK...NON VFR LINGERING INTO TUESDAY ACROSS NORTHEAST OH AND
NORTHWEST PA. NON-VFR PROBABLE WEDNESDAY NIGHT INTO THURSDAY IN
-SHRA.
&&
.MARINE...
WINDS WILL INCREASE DURING THE DAY TODAY ON THE LAKE BUT
NOT EXPECTING THEM TO GO ABOVE GALES. WINDS WILL REMAIN MOSTLY
SOUTHERLY TODAY AND KEEP THE STRONGEST WINDS AND HIGHEST WAVES
OUTSIDE THE 5 NM NEARSHORE WATERS. ONCE WINDS BECOME MORE
WESTERLY...EXPECTING SMALL CRAFT CONDITIONS TO DEVELOP AROUND 5 PM
THIS AFTERNOON AND LAST UNTIL AROUND 4 PM TOMORROW AFTERNOON. SO
WILL GO AHEAD AND HOIST THE SMALL CRAFT FOR THIS TIME PERIOD.
OTHERWISE...WINDS DIMINISH FAIRLY QUICKLY TOMORROW EVENING AND
REMAIN FAIRLY LIGHT THROUGH THURSDAY MORNING. THEN...AS A COLD
FRONT MOVES EAST...WINDS WILL INCREASE AGAIN THURSDAY THROUGH
FRIDAY AND POSSIBLY CAUSE SMALL CRAFT ADVISORIES TO BE ISSUED ONCE
AGAIN.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...NONE.
PA...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM THIS AFTERNOON TO 4 PM EST
TUESDAY FOR LEZ142>149.
&&
$$
SYNOPSIS...TK
NEAR TERM...TK
SHORT TERM...TK
LONG TERM...LOMBARDY
AVIATION...KEC
MARINE...LOMBARDY
AREA FORECAST DISCUSSION
NWS MEDFORD OR
402 AM PST MON DEC 14 2015
.DISCUSSION...IN THE WAKE OF YESTERDAY`S STORM...WE ARE NOW IN
A COLD NORTH TO NORTHWEST FLOW ALOFT. THERE ARE STILL A COUPLE OF
DISTURBANCES THAT WILL MOVE THROUGH ON THE BACK SIDE OF AN UPPER
LEVEL TROUGH, THE AXIS OF WHICH IS CENTERED OVER IDAHO AND NEVADA
EARLY THIS MORNING.
THE FIRST DISTURBANCE IS MOVING THROUGH NOW WITH NUMEROUS SHOWERS
OCCURRING FROM THE CASCADES AND SISKIYOUS NORTH AND WEST. SNOW
LEVELS ARE RUNNING ABOUT 1500 TO 2000 FEET...THOUGH THEY COULD BE
LOCALLY DOWN AS LOW AS 1000 FEET IN HEAVIER SHOWERS. SOME SHOWERS
MAY ALSO MAKE IT SOUTH AND EAST OF THE MOUNTAINS, BUT THESE WILL
BE SCATTERED AT BEST. A WINTER WEATHER ADVISORY AT WSWMFR REMAINS
IN EFFECT THIS MORNING OVER THE WEST SIDE. THE BEST CHANCE FOR AN
INCH OR TWO OF NEW SNOW WILL BE ON THE NORTH AND WEST FACING
SLOPES OF JACKSON AND JOSEPHINE COUNTIES AS WELL AS THE UMPQUA
DIVIDE, MAINLY ABOVE 1500 FEET. THE MAIN PASSES ON INTERSTATE 5 IN
OREGON COULD BE IMPACTED BY THESE HEAVIER SNOW SHOWERS.
THE LATEST HRRR IS SHOWING ANOTHER DISTURBANCE MOVING IN THIS
AFTERNOON, WHICH WILL KEEP SHOWERS GOING INTO THE EVENING HOURS,
BUT SNOW LEVELS SHOULD RISE TO NEAR 2000 FEET WEST OF THE CASCADES
AND ROAD SURFACE TEMPERATURES SHOULD WARM ENOUGH TO PRECLUDE
SIGNIFICANT SNOW IMPACTS AT THE LOWER ELEVATIONS. THERE WON`T BE
ENOUGH SNOW TO WARRANT A NEW ADVISORY AT HIGHER ELEVATION SPOTS
LIKE SISKIYOU SUMMIT, BUT TRAVEL STILL MAY BE HAZARDOUS OVER THE
PASS.
AN UPPER RIDGE OFFSHORE WILL BEGIN TO BUILD INTO THE AREA TONIGHT.
PARTIAL CLEARING IN THE EVENING WEST OF THE CASCADES WILL ALLOW
AREAS OF LOW CLOUDS AND FOG TO DEVELOP IN THE VALLEYS. TUESDAY
WILL BE A DRY DAY FOR MOST AREAS, THOUGH THERE MAY BE SOME LIGHT
RAIN OVER THE COASTAL WATERS AND NEAR REEDSPORT AND FLORENCE.
THE NEXT SIGNIFICANT WEATHER SYSTEM WILL APPROACH THE AREA
WEDNESDAY SENDING A WET WARM FRONT THROUGH THE AREA WEDNESDAY
NIGHT. THE 00Z GFS20 BRINGS PRECIPITATION ONSHORE WEDNESDAY
AFTERNOON AND IS ABOUT 6 HOURS FASTER THAN 00Z ECMWF. EITHER WAY,
SIGNIFICANT RAINFALL IS EXPECTED ACROSS MOST OF THE AREA WITH THE
FRONT WEDNESDAY NIGHT. SNOW LEVELS WILL BE A BIT HIGHER WITH THIS
SYSTEM STARTING NEAR 3500 FEET WEDNESDAY EVENING, THEN SURGING TO
AROUND 7000-7500 FEET BY THURSDAY EVENING. SNOW IMPACTS SHOULD BE
RESERVED FOR THE HIGHEST ELEVATIONS. SIMILAR TO THE MOST RECENT
STORM, THE WARM FRONT WILL BE FOLLOWED BY ANOTHER WET COLD FRONT
THAT WILL PUSH VERY SLOWLY THROUGH THE AREA THURSDAY THROUGH
FRIDAY NIGHT, BRINGING A RENEWED THREAT OF SIGNIFICANT RAINFALL ON
ALREADY SATURATED SOILS. SINCE RIVERS, CREEKS AND STREAMS WILL
STILL BE RUNNING RELATIVELY HIGH AND LOWER ELEVATION SNOW WILL
LIKELY MELT, WE EXPECT HYDROLOGY ISSUES ONCE AGAIN. THE UPPER
TROUGH WITH THIS SYSTEM WILL LIKELY SPLIT AS IT MOVES OVER THE
AREA SATURDAY AND PRECIPITATION WILL GRADUALLY TAPER OFF SOUTH AND
EAST OF THE CASCADES AND END SATURDAY NIGHT. THERE WON`T BE MUCH
OF A BREAK THOUGH...SINCE THE NEXT SYSTEM IS EXPECTED TO MOVE IN
SUNDAY. SPILDE
&&
.AVIATION...FOR THE 14/12Z TAF CYCLE...NUMEROUS TO WIDESPREAD RAIN
AND SNOW SHOWERS FROM THE CASCADES WESTWARD ARE EXPECTED THROUGH
THIS AFTERNOON...THEN SHOWERS WILL BECOME SCATTERED DURING THE
EVENING. FROM THE CASCADES WEST...THIS WILL CREATE A MIX OF IFR AND
MVFR CIGS WITH PERIODS OF MOUNTAIN OBSCURATIONS THROUGH THIS
EVENING. EAST OF THE CASCADES...CONDITIONS WILL BE MAINLY VFR WITH
ISOLATED SNOW SHOWERS AND MVFR CEILINGS. SHOWERS WILL TAPER OFF
OVERNIGHT WITH VFR CONDITIONS DEVELOPING EXCEPT FOR IFR/MVFR VALLEY
LOW CLOUDS AND FOG FORMING WEST OF THE CASCADES AND POSSIBLY IN THE
KLAMATH BASIN. /CC
&&
.MARINE...UPDATED 300 AM PST MONDAY 14 DEC 2015....GUSTY NORTHWEST
WINDS MAY BRIEFLY LOWER LATE THIS MORNING THEN INCREASE AGAIN THIS
AFTERNOON THROUGH THIS EVENING. VERY STEEP SEAS WILL CONTINUE TODAY
INTO THIS EVENING. SEAS WILL GRADUALLY LOWER BUT WILL REMAIN STEEP
THROUGH TUESDAY MORNING. HIGH AND VERY LONG PERIOD SWELL IS EXPECTED
TO MOVE INTO THE WATERS WEDNESDAY MORNING. A COUPLE FRONTS WILL MOVE
INTO THE AREA WEDNESDAY NIGHT THROUGH THURSDAY NIGHT. THIS IS
EXPECTED TO BRING PERIODS OF STRONG GUSTY SOUTH WINDS AS WELL AS
STEEP TO VERY STEEP SEAS. GALES ARE POSSIBLE WITH THE FRONT ON
THURSDAY NIGHT. /CC
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1000
FEET FOR FOR ORZ024.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1000
FEET FOR FOR ORZ023.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ025.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1500
FEET FOR FOR ORZ026.
WINTER WEATHER ADVISORY UNTIL 4 AM PST EARLY THIS MORNING FOR
ORZ027-028.
CA...WINTER WEATHER ADVISORY UNTIL 4 AM PST EARLY THIS MORNING ABOVE
2000 FEET FOR FOR CAZ080.
WINTER WEATHER ADVISORY UNTIL 4 AM PST EARLY THIS MORNING FOR
CAZ081.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM
10 PM THIS EVENING TO 10 AM PST TUESDAY FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 10 PM PST THIS EVENING FOR
PZZ350-356-370-376.
$$
MAS/CC/DW
AREA FORECAST DISCUSSION
NWS PORTLAND OR
306 AM PST MON DEC 14 2015
.SYNOPSIS...SCATTERED RAIN AND MOUNTAIN SNOW SHOWERS PERSIST AS A
COOL UPPER LEVEL TROUGH MOVES THROUGH THE PAC NW. WEAK LOW PRESSURE
OFF THE WA COAST WILL DROP SOUTHEAST TODAY...BRINGING A BATCH OF
STEADIER PRECIPITATION TO THE OREGON COAST AND COAST RANGE. SNOW
LEVELS WILL BE 1500-2000 FEET IN THE COAST RANGE AS THIS OCCURS...SO
SOME ACCUMULATING SNOW IS LIKELY THIS MORNING IN THE HIGHER
ELEVATIONS OF POLK/LINCOLN COUNTIES SOUTHWARD. HIGH PRESSURE WILL
TAKE OVER TONIGHT...AND CLEARING SKIES COULD LEAD TO SOME VALLEY FOG
AND A LITTLE BLACK ICE IN THE COLDER SPOTS TONIGHT AND TUE MORNING.
HIGH PRESSURE SHOULD KEEP TUESDAY MOSTLY DRY...THEN RAIN CHANCES
INCREASE AGAIN TUESDAY NIGHT AND WEDNESDAY AS WEAK FRONT CLIPS
THROUGH WASHINGTON AND NORTHERN OREGON. THE NEXT STRONG FRONTAL
SYSTEM WILL LIKELY BRING HEAVIER RAIN BACK TO THE REGION LATER
WEDNESDAY THROUGH THURSDAY...WITH SNOW IN THE CASCADES. ENOUGH COLD
AIR MAY LINGER FOR WINTRY PRECIPITATION IN THE HOOD RIVER VALLEY WITH
THIS SYSTEM. COOL AND UNSETTLED WEATHER IS EXPECTED TO FOLLOW INTO
THE WEEKEND...WITH ADDITIONAL SNOW POSSIBLE FOR THE CASCADES.
&&
.SHORT TERM...TODAY THROUGH WEDNESDAY...UNSETTLED WEATHER CONTINUES
THIS MORNING WITH SCATTERED SHOWERS ACROSS SW WASHINGTON AND NW
OREGON...MAINLY DUE TO AN UPPER TROUGH MOVING THROUGH THE PAC NW.
SOME STEADIER ECHOES ARE STARTING TO SHOW UP ON KLGX NWS DOPPLER
RADAR...ASSOCIATED WITH WEAK LOW PRESSURE OFF THE WA COAST. AS THE
LOW MOVES S-SE...EXPECT STEADIER PRECIP TO MOVE ONSHORE SOUTH OF
ABOUT TILLAMOOK THIS MORNING. PAST FEW HRRR RUNS HAVE SHOWN A SWATH
OF MODERATE PRECIP MOVING INTO THE CENTRAL COAST AND COAST RANGE OF
OREGON AROUND 7 AM...CONTINUING UNTIL ABOUT NOON AS A 1019 MB LOW
MOVES THROUGH THE AREA. OTHERWISE...SHALLOW INSTABILITY WILL PROBABLY
KEEP SCATTERED SHOWERS AROUND WELL INTO THE DAY. HIGHER PRESSURE BOTH
AT THE SURFACE AND ALOFT WILL LIKELY CAUSE SUBSIDENCE AND DRYING
LATER THIS AFTERNOON AND EVENING...WITH WARMER AIR ALOFT INCREASINGLY
CAPPING ANY SHALLOW CONVECTION AND BRINGING SHOWER ACTIVITY TO AN
END.
SKIES MAY CLEAR A BIT TONIGHT AS HIGH PRESSURE BUILDS IN AND
NORTHERLY FLOW DEVELOPS. THE NORTHERLY FLOW SHOULD KEEP THE BOUNDARY
LAYER BARELY MIXED ENOUGH TO PREVENT WIDESPREAD FOG...BUT SOME
PATCHES WILL PROBABLY DEVELOP IN THE MORE FOG-PRONE SHELTERED VALLEYS
DUE TO THE VERY WET GROUND. MOS TEMPS ARE BELOW FREEZING TONIGHT IN
THE COOLER VALLEY SPOTS...SO THERE MAY BE SOME BLACK ICE TONIGHT/
EARLY TUE MORNING WHERE ROADS REMAIN WET FROM ALL THE RECENT
RAIN WE HAVE HAD.
SUNDAY DECEMBER 13 WAS THE 13TH DAY IN A ROW WITH MORE THAN A QUARTER
INCH OF RAIN AT KPDX...BREAKING THE PREVIOUS RECORD OF 11 DAYS SET
JANUARY 16-26 1970. THERE IS A DECENT CHANCE THAT TODAY WILL BREAK
THAT STREAK. IF NOT TODAY...TUESDAY SHOULD BREAK THE STREAK AND MAY
ACTUALLY BE TOTALLY DRY FOR MUCH OF THE FORECAST AREA AS HIGH
PRESSURE BRIEFLY BUILDS INTO THE PAC NW. THIS IS BY NO MEANS A
CERTAINTY...AS A WEAK COLD FRONT IS FCST TO CLIP WA/N OR TUE NIGHT
INTO WED AND MAY BRING SOME SHOWERS BACK TO OUR NORTHERN ZONES.
THE TUE NIGHT/EARLY WED COLD FRONT IS FAIRLY IMPORTANT...AS IT MAY
RECHARGE THE COLD AIR EAST OF THE CASCADES AND SET UP A WEAK
BAROCLINIC ZONE OVER NORTHWEST OF WEST-CENTRAL OREGON. IF THIS COLD
AIR GETS INTO THE HOOD RIVER VALLEY AND EASTERN SKAMANIA COUNTY...IT
MAY END UP STUCK THERE AS A MUCH STRONGER AND WETTER SYSTEM ARRIVES
WED NIGHT/THU. THE BAROCLINIC ZONE WOULD ALSO PROVIDE AN OVERRUNNING
SURFACE FOR THE MOIST AND RELATIVELY WARM ATMOSPHERIC RIVER ARRIVES
LATE WED. THE RESULTING ISENTROPIC LIFT COULD YIELD ANOTHER ROUND OF
HEAVY RAIN FOR MUCH OF THE FORECAST AREA LATE WED INTO THU. PREFER
THE 00Z GFS SOLUTION...AS THE RELATIVELY DRIER/SLOWER 12Z/00Z ECMWF
HAS BEEN A BIT OF AN OUTLIER AMONGST ITS OWN ENSEMBLE MEMBERS. IF THE
GFS QPF VERIFIES...THERE MAY BE ANOTHER ROUND OF HYDROLOGIC PROBLEMS
ACROSS MUCH OF OUR FORECAST AREA WED NIGHT/THU...IN ADDITION TO HEAVY
SNOW AND/OR ICE IN THE HOOD RIVER VALLEY AND EASTERN SKAMANIA COUNTY.
WHILE CONFIDENCE IS INCREASING THAT THIS WEEK WILL BE ANOTHER ACTIVE
ONE WITH A VARIETY OF WEATHER CONCERNS...DETAILS MAY STILL CHANGE AS
FUTURE MODEL RUNS COME IN. STAY TUNED.WEAGLE
.LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...CONFIDENCE IS GROWING
THAT YET ANOTHER ATMOSPHERIC RIVER EVENT WILL HAMMER THE PAC NW WITH
HEAVY RAIN WED NIGHT AND THURSDAY...POSSIBLY LINGERING INTO FRIDAY.
THIS IS NOT AN OPPORTUNE TIME FOR THIS TO OCCUR AS RIVERS WILL STILL
BE HIGH AND THE GROUND SATURATED FROM LAST WEEK. THE 00Z 4 KM UW
WRF-GFS ALREADY HAS 2-5 INCHES OF QPF FROM THIS SYSTEM IN THE HIGHER
TERRAIN BY THE END OF THE RUN AT 12Z THU...WITH ABOUT AN INCH IN THE
LOWLANDS. THE 12Z/00Z ECMWF HAVE BEEN NOTABLY SLOWER/DRIER THAN THE
U.S. MODELS...BUT AT LEAST THE 00Z ECMWF IS SOMEWHAT OF AN OUTLIER
AMONGST ITS ENSEMBLE MEMBERS WITH MOST ENSEMBLES BRINGING RAIN IN
AROUND THE SAME TIME AS THE 00Z GFS. THE 06Z GFS DOES NOT TAKE ITS
FOOT OFF THE ACCELERATOR...REMAINING CONSISTENT WITH PREVIOUS RUNS.
AFTER COORDINATION WITH WPC AND OUR SURROUNDING OFFICES...DECIDED TO
DISREGARD THE DRIER ECMWF RUNS AND OUR FORECAST BRINGS IN SIGNIFICANT
QPF BY WED NIGHT. WILL HOLD OFF ON ISSUING A HYDROLOGIC STATEMENT FOR
NOW...BUT IF THE 12Z ECMWF COMES IN LINE WITH THE WETTER U.S. MODELS
FUTURE SHIFTS MAY WANT TO DO SO. IF THE 00Z GFS IS TO BE BELIEVED...
THE HIGHER TERRAIN MAY SEE ANOTHER 5-10 INCHES OF RAIN LATE WED-
FRI...WITH ANOTHER 2-4 INCHES IN THE INTERIOR LOWLANDS INCLUDING THE
HOOD RIVER VALLEY.
WITH COLD AIR POSSIBLY TRAPPED IN THE HOOD RIVER VALLEY AND EASTERN
SKAMANIA COUNTY...THERE IS THE POTENTIAL FOR HEAVY SNOW OR ICE AT
LEAST IN THE HIGHER PORTIONS OF THOSE VALLEYS. WHILE SNOW LEVELS
WILL BE RISING IN GENERAL...THEY MAY BE MORE STUBBORN NORTH OF
SANTIAM PASS. THIS COULD LEAD TO A DECENT AMOUNT OF SNOW FOR MOUNTS
HOOD AND ADAMS...WHILE MOUNT ST. HELENS AND THE LANE COUNTY CASCADES
SEE MAINLY RAIN OR MIXED RAIN/SNOW. STILL TOO EARLY TO SORT OUT THESE
DETAILS PRECISELY AND MUCH MAY CHANGE BETWEEN NOW AND THURSDAY.
THE BAROCLINIC ZONE WILL LIKELY SHIFT SOUTHWARD FRIDAY...PUSHING THE
HEAVIEST RAIN SOUTH TOWARD THE OR/CA BORDER. MODELS SHOW DECENT
AGREEMENT THAT ANOTHER COOL UPPER TROUGH WILL MOVE ACROSS THE PAC NW
BEHIND THIS...FOR MORE SHOWERS FRI/SAT. THE NEXT FRONT MAY ARRIVE AS
EARLY AS SAT NIGHT/SUN FOR MORE RAIN AND MOUNTAIN SNOW. BOTTOM LINE
IS...THERE IS NO END IN SIGHT TO OUR VERY ACTIVE DECEMBER WEATHER...
AT LEAST NOT FOR THE NEXT 7-10 DAYS. WEAGLE
&&
.AVIATION...VFR ACROSS REGION THIS AM...WITH POCKETS OF MVFR
CONDITIONS UNDER THE SCATTERED SHOWERS. WILL SEE MVFR CIGS
INCREASE FROM NW TO SE ACROSS REGION AFTER 12Z AS WEAK LOW PRES
ARRIVES FROM THE NW. THE WEAK LOW WILL ALSO INCREASE SHOWERS. MAY
HAVE PERIODS OF IFR ALONG THE COAST...BUT STILL THINK THIS WOULD
BE PATCHY IN NATURE TO S OF KAST. CONDITIONS WILL GRADUALLY
IMPROVE BACK TO LOW VFR AFTER 03Z AS SYSTEMS MOVES ON INTO SW
OREGON AND WEAK HIGH PRES BUILDS OVER NW OREGON.
KPDX AND APPROACHES...SHOWERS INCREASING AFTER 16Z. PREDOMINATELY
VFR CONDITIONS TODAY INTO THIS EVENING...BUT WILL SEE CIGS FLIRT
WITH HIGH END MVFR AT TIMES BETWEEN 17Z AND 23Z.
&&
.MARINE...GUSTY NW WINDS ARE PERSISTING THIS AM...MAINLY DUE TO
TIGHTER GRADIENT ON THE S AND SW SIDE OF THE LOW PRES THAT IS
APPROACHING FROM THE NW. AS THE LOW DROPS INTO THE REGION LATER
THIS AM...THE WINDS WILL EASE BACK TO 20 KT OR LESS. BUT THIS NOT
LIKELY UNTIL 5 OR 6 AM. SO WILL MAINTAIN GALE WARNING ON ALL
WATERS THROUGH 6 AM TODAY.
SEAS ALSO SLOW TO SUBSIDE. GENERALLY RUNNING AT 20 TO 23 FT...
THOUGH HAVE SEEN SEAS S OF CASCADE HEAD STARTING TO LOWER BACK A
TAD. THESE WAVES MORE DEPENDENT ON THE WINDS...SO AS THE WINDS
EASE THIS AM...SO WILL THE SEAS. STILL LOOKS AS THOUGH SEAS WILL
DROP BACK UNDER 20 FT BY 8 AM... WITH SEAS SUBSIDING BACK TO 14 TO
16 FT BY AFTERNOON.
BREAK IN THE WEATHER FOR LATER TONIGHT THROUGH TUE NIGHT...WITH
WINDS 15 KT OR LESS AND SEAS AROUND 10 FT. BUT...ANOTHER SYSTEM
WILL APPROACH FROM THE W WED. THIS WILL BRING WINDS BACK ABOVE 25
KT...WITH SEAS BUILDING BACK INTO THE 12 TO 15 FT RANGE. MORE
FRONT WILL ARRIVE LATER THIS WEEK...WITH CONTINUED GUSTY WINDS AND
HIGHER SEAS AT TIMES.ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...HIGH SURF ADVISORY UNTIL 8 AM TODAY FOR COAST OF NORTH AND
WEST CENTRAL OREGON.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 1 PM PST THIS
AFTERNOON FOR CENTRAL COAST RANGE OF WESTERN OREGON.
WA...HIGH SURF ADVISORY UNTIL 8 AM TODAY FOR S WASHINGTON COAST.
PZ...GALE WARNING UNTIL 6 AM TODAY ON ALL COASTAL WATERS.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA BAR CONDITIONS TODAY
AND THIS EVENING.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1036 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION LATE TODAY.
TEMPERATURES WILL BE WARM AGAIN TODAY...COOLING A BIT FOR MIDWEEK.
ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. SEASONAL TEMPERATURES ARE IN STORE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
SHOWERS ALMOST TO KCLE AND KZZV. COLD FRONT IS ON THE OH/IN
BORDER. ARRIVAL TIME PER LATEST HRRR/RAP/NAM/GFS ENSEMBLE IS
SPOT ON AROUND 19Z IN THE WESTERN ZONES...WITH CFROPA NOT UNTIL
ABOUT 4 HRS AFTER. THE SUN IS BREAKING THRU THE MULTI-LAYERED
CLOUDS...AND TEMPS SHOULD GET INTO THE 60S BEFORE THE CLOUDS ROLL
IN FROM THE WEST. MAXES EXPECTED TO AGAIN BE NEAR-RECORD LEVEL.
SHOWERS ARE PRETTY LIGHT.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH 6 PM TUESDAY/...
THE FRONT SHOULD BE THRU THE EASTERN ZONES BY MIDNIGHT. THE
GHUIDANCE DOES BREAK THE SHOWERS INTO A SERIES OF LINES...SO THE
100 POPS MAY BE FAR TOO HIGH FOR EXPECTED COVERAGE - BUT THE FAST
MOVEMENT OF THE SHOWERS AND EXTREMELY HIGH UNCERTAINTY FOR PRECIP
O/O OF 0.25 INCHES BEFORE 00Z IN THE W AND BY 04Z IN THE EAST
MEANS THE 100 POPS ARE THE WAY TO GO. A STRAY RUMBLE OF THUNDER
IS POSS IN THE SE IN CONJUNCTION WITH SPC TSTM AREA AND SEEM IN
LINE WITH HIGH DEWPOINTS AND A FRONT MOVING THRU. BUT LI/S ARE
NOT IMPRESSIVE AT ANY POINT. WINDS WILL BECOME GUSTY BEHIND THE
FRONT AND SOME SHOWERS ARE EXPECTED IN THE WEST TONIGHT WITH LOW
TEMPERATURES ABOUT 10F ABOVE NORMAL MAXES FOR THIS TIME OF YEAR.
TUESDAY SHOULD ALSO BE MILD FOR THIS TIME OF YEAR...WITH ONLY A
STRAY SHOWER OR TWO IN THE WRN HIGHLANDS. COLD ADVECTION WILL KEEP
TEMPS STEADY OR ONLY RISING A FEW DEGS FROM TUESDAY MORNING TEMPS.
GUSTY WINDS WILL BE THE STORY ON TUESDAY...BUT GUSTS SHOULD STAY
WELL BELOW 30 KTS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
PERSISTENT SOUTH TO SOUTHEASTERLY FLOW OVERNIGHT HAS KEPT ALL
WESTERN AND CENTRAL TAF SITES VFR. THE EASTERN TAF SITES ARE A
DIFFERENT STORY AS WINDS ARE MORE EASTERLY...BRINGING MOIST MORE
UPSLOPE FLOW INTO THE REGION...ALLOWING FOR IFR AND LOWER CIGS AND
VSBYS AT LNS AND MDT. THE VSBY CONDITIONS WILL CONTINUE THROUGH
MID MORNING BEFORE THEY BEGIN TO LIFT LATE THIS MORNING...EARLY
THIS AFTERNOON. THE CURRENT HRRR RUNS BRING PRECIPITATION INTO
THE WESTERN TAF SITES BY 19Z...AND THROUGH THE EASTERN TAF SITES
AFTER 21Z. SHOWERS WILL REDUCE CIGS AND VSBYS TO MVFR AND LOWER
ACROSS THE REGION...AND THE RESULTANT MOISTURE SHOULD KEEP MVFR
CIGS WITH IFR CIGS AND VSBYS POSSIBLE TONIGHT AND INTO TUESDAY
MORNING.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 64/1927 42/27
KIPT 65/1901 39/25
KAOO 59/2006 38/24
KBFD 54/2001 33/19
*STATE COLLEGE 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...DANGELO/TYBURSKI
LONG TERM...RXR
AVIATION...DANGELO/CERU
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
850 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION TODAY.
TEMPERATURES WILL BE WARM AGAIN TODAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. SEASONAL TEMPERATURES ARE IN STORE FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SHOWERS INTO KDAY AND MOVING QUICKLY EASTWARD. THE COLD FRONT IS
BACK CLOSER TO KIND. ARRIVAL TIME PER LATEST HRRR/RAP/NAM/GFS
ENSEMBLE IS SPOT ON AROUND 19Z IN THE WESTERN ZONES...WITH CFROPA
NOT UNTIL ANOTHER 4 HRS AFTER. WITH SOME SUN BREAKING THRU THE
MULTI-LAYERED CLOUDS...TEMPS SHOULD RISE VERY QUICKLY THIS
MORNING. SHALLOW COOLER AIR IN THE EASTERN VALLEYS - BUT
WIND/MIXING SHOULD HELP THEM GET MILD...TOO. REST OF THE AREA IS
ALREADY IN THE 50S AND KIPT THE WARMEST SPOT /GASP/ AT 60F. MAXES
EXPECTED TO AGAIN BE NEAR-RECORD LEVEL.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/...
HIGHEST POPS WILL BE THRU 02Z...BUT THE FRONT WILL TAKE ANOTHER
COUPLE HRS TO GO THRU...AND WILL LINGER ISOLD SHRA INTO THE EARLY
NIGHT. A STRAY RUMBLE OF THUNDER IS POSS IN THE SE IN CONJUNCTION
WITH SPC TSTM AREA. WINDS WILL BE GUSTY BEHIND THE FRONT AND SOME
SHOWERS ARE EXPECTED IN THE WEST MONDAY NIGHT WITH LOW
TEMPERATURES STILL SLIGHTLY ABOVE NORMAL. TUESDAY SHOULD ALSO BE
MILD FOR THIS TIME OF YEAR...WITH ONLY A STRAY SHOWER OR TWO IN
THE WRN HIGHLANDS. GUSTY WINDS WILL BE THE STORY ON TUESDAY...BUT
GUSTS SHOULD STAY WELL BELOW ADVY THRESHOLD OF 40KTS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
PERSISTENT SOUTH TO SOUTHEASTERLY FLOW OVERNIGHT HAS KEPT ALL
WESTERN AND CENTRAL TAF SITES VFR. THE EASTERN TAF SITES ARE A
DIFFERENT STORY AS WINDS ARE MORE EASTERLY...BRINGING MOIST MORE
UPSLOPE FLOW INTO THE REGION...ALLOWING FOR IFR AND LOWER CIGS AND
VSBYS AT LNS AND MDT. THE VSBY CONDITIONS WILL CONTINUE THROUGH
MID MORNING BEFORE THEY BEGIN TO LIFT LATE THIS MORNING...EARLY
THIS AFTERNOON. THE CURRENT HRRR RUNS BRING PRECIPITATION INTO
THE WESTERN TAF SITES BY 19Z...AND THROUGH THE EASTERN TAF SITES
AFTER 21Z. SHOWERS WILL REDUCE CIGS AND VSBYS TO MVFR AND LOWER
ACROSS THE REGION...AND THE RESULTANT MOISTURE SHOULD KEEP MVFR
CIGS WITH IFR CIGS AND VSBYS POSSIBLE TONIGHT AND INTO TUESDAY
MORNING.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 64/1927 42/27
KIPT 65/1901 39/25
KAOO 59/2006 38/24
KBFD 54/2001 33/19
*STATE COLLEGE 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO/TYBURSKI
SHORT TERM...DANGELO/TYBURSKI
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
641 AM EST MON DEC 14 2015
.SYNOPSIS...
A STORM WILL PUSH A COLD FRONT THROUGH THE REGION ON MONDAY.
TEMPERATURES WILL BE WARM AGAIN FOR MONDAY...COOLING A BIT FOR
MIDWEEK. ANOTHER STORM WILL MOVE ACROSS THE GREAT LAKES ON
THURSDAY...PUSHING A STRONGER COLD FRONT THROUGH CENTRAL
PENNSYLVANIA. THIS WILL MARK THE BEGINNING OF A RETURN TO MORE
SEASONAL TEMPERATURES FOR THE WEEKEND.
&&
.NEAR TERM /UNTIL 8 AM THIS MORNING/...
LEFT A MENTION OF PATCHY FOG THROUGH THE MORNING HOURS OVER THE
SOUTHEAST FORECAST AREA AS VISIBILITIES HAVE BEEN JUMPING ABOVE
AND BELOW 3/4SM THROUGH THE MORNING.
STEADY RAIN NOW MOVING INTO INDIANA WITH A FEW SHOWERS AHEAD IN
OHIO. THIS AREA WILL PROGRESS EASTWARD THROUGH THE EARLY MORNING
BUT WEST OF THE AREA THROUGH SUNRISE. SOME DRIZZLE IS POSSIBLE
OVER THE EASTERN AREAS WHERE EAST FLOW AND DEWPOINTS IN THE LOW TO
MID 50S PERSIST.
&&
.SHORT TERM /8 AM THIS MORNING THROUGH 6 PM TUESDAY/...
EVEN WITH CLOUDS AND SCATTERED SHOWERS AHEAD OF THE APPROACHING
FRONT...ROBUST SOUTHERLY FLOW WILL ALLOW TEMPERATURES TO CLIMB
INTO THE 60S IN ALL LOCATIONS THROUGH MID DAY.
LOW CLOUDS OVER THE NE WILL PROBABLY KEEP THE TEMPS FROM CLIMBING
TOO QUICKLY THERE...BUT THE TIGHTENING PRES GRADIENT WILL LIKELY
MIX THEM OUT BY AFTN.
COLD FRONT WILL BE APPROACHING THE FORECAST AREA BY MID
AFTN. KEPT THE HIGHEST POPS BETWEEN 18Z- 00Z...STEADILY MOVING
THEM W-E. A STRAY RUMBLE OF THUNDER IS POSS IN THE SE IN
CONJUNCTION WITH SPC TSTM AREA...HOWEVER...THE COOLER START TO
THE DAY IN THE NE SHOULD PRECLUDE THEM FROM HEARING THUNDER. WINDS
WILL BE GUSTY BEHIND THE FRONT AND SOME SHOWERS ARE EXPECTED IN
THE WEST MONDAY NIGHT WITH LOW TEMPERATURES STILL SLIGHTLY ABOVE
NORMAL.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
ANOTHER LOW PRESSURE SYSTEM SLIDES THROUGH ON THURSDAY...WITH A
SHOT OF SEASONABLY COLD AIR ARRIVING FOR NEXT WEEKEND.
AS LOW PRESSURE AREA SLIDES EAST THROUGH NEW ENGLAND ON TUESDAY...
FLOW AROUND PERIPHERY OF LOW WILL BRING BREEZY WINDS ON TUE...WITH
COOLER YET STILL QUITE MILD TEMPS IN THE 40S AND 50S.
RIDGE RE-ESTABLISHES OVER THE OHIO VALLEY AND BUILDS IN FROM THE
WEST MIDWEEK AS NEXT TROUGH DEEPENS OVER THE ROCKIES. THIS WILL
BLOCK ANY REAL COLD AIR FROM SLIDING IN FROM THE NW...WHILE FLOW
OF MILD AIR AGAIN BEGINS TO ADVECT NORTHWARD OVER THE TENNESSEE
VALLEY...KEEPING EVEN OVERNIGHT LOW TEMPERATURES ABOVE FREEZING
EVERYWHERE RIGHT UP THROUGH THURSDAY.
THE TROUGH OVER THE WEST-CENTRAL CONUS WILL SHIFT EAST INTO UPPER
MIDWEST LATE WEEK...WITH A SHORTWAVE SLIDING DOWN THE BACK SIDE TO
REINFORCE IT AND BEGIN THE PUSH OF COLDER AIR THAT WILL DROP US
BACK TO SEASONAL READINGS. FROPA LOOKS TO BE THU-THU NIGHT WITH
GENERALLY LIGHT QPF AMOUNTS AND PLENTY OF CLOUDS.
AS SECONDARY TROUGH ARRIVES 850MB TEMPS FINALLY DROP BACK BELOW
0C ON FRI. NW/W FLOW WILL BRING IMPROVING CONDITIONS TO THE SE
2/3RDS...BUT SCT SNOW SHOWERS WILL BE POSS IN THE NW MTNS THROUGH
THE WEEKEND. BEST CHANCES WILL BE FRI NIGHT INTO SAT AS FLOW BACKS
MORE TO THE NW. BRISK LOW LEVEL FLOW WILL ALSO BRING SOME BREEZY
WINDS FOR THE WEEKEND.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
PERSISTENT SOUTH TO SOUTHEASTERLY FLOW OVERNIGHT HAS KEPT ALL
WESTERN AND CENTRAL TAF SITES VFR. THE EASTERN TAF SITES ARE A
DIFFERENT STORY AS WINDS ARE MORE EASTERLY...BRINGING MOIST MORE
UPSLOPE FLOW INTO THE REGION...ALLOWING FOR IFR AND LOWER CIGS AND
VSBYS AT LNS AND MDT...AND MVFR AT IPT. THE VSBY CONDITIONS WILL
CONTINUE THROUGH MID MORNING BEFORE THEY BEGIN TO LIFT LATE THIS
MORNING...EARLY THIS AFTERNOON. THE LOW CIGS WILL CONTINUE OUT
AHEAD OF AN APPROACHING FRONT SO EXPECT THE MVFR CIGS TO
CONTINUE. THE CURRENT HRRR RUNS BRING PRECIPITATION INTO THE
WESTERN TAF SITES BY 19Z...AND THROUGH THE EASTERN TAF SITES AFTER
21Z. SHOWERS WILL REDUCE CIGS AND VSBYS TO MVFR AND LOWER ACROSS
THE REGION...AND THE RESULTANT MOISTURE SHOULD KEEP MVFR CIGS WITH
IFR CIGS AND VSBYS POSSIBLE TONIGHT AND INTO TUESDAY MORNING.
OUTLOOK...
TUE...LOW CIGS POSS KBFD/KJST...MAINLY EARLY.
WED...PATCHY AM FOG POSSIBLE...MAINLY CENTRAL MTNS.
THU...LOW CIGS/SHRA POSSIBLE.
FRI...NO SIG WX EXPECTED.
&&
.CLIMATE...
MAX TEMPERATURES OF RECORD...
---------------------------------------------------------------------
LOCATION MON/14TH TUE/15TH AVG HI/LO
---------------------------------------------------------------------
KMDT 64/1927 42/27
KIPT 65/1901 39/25
KAOO 59/2006 38/24
KBFD 54/2001 33/19
*STATE COLLEGE 63/1927 60/2006 39/25
*COOP SITE THAT REPORTS VALUES FROM 7AM-7AM, SO HIGH TEMP WILL BE
VALUE FROM THE PREVIOUS 24-HRS RECORDED AT 7 AM (GENERALLY OCCURS
THE AFTERNOON BEFORE).
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DANGELO/LAMBERT/RXR
NEAR TERM...TYBURSKI
SHORT TERM...DANGELO/TYBURSKI
LONG TERM...RXR
AVIATION...FITZGERALD/CERU
CLIMATE...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
919 AM EST MON DEC 14 2015
.SYNOPSIS...
A DEEP LOW PRESSURE AREA WILL MOVE RAPIDLY FROM THE SOUTHERN
PLAINS TOWARD THE GREAT LAKES TODAY...PUSHING A COLD FRONT THROUGH
THE MID-ATLANTIC. WEAK HIGH PRESSURE WILL BUILD ACROSS THE REGION
FOR TUESDAY AND WEDNESDAY. LOW PRESSURE WILL THEN DEVELOP ACROSS
THE SOUTHEAST U.S. THURSDAY...PULLING A STRONGER COLD FRONT
THROUGH OUR REGION FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 919 AM EST MONDAY...
MODIFIED TEMPERATURES WITH LATEST OBS AND RAISED HIGH TEMPERATURES
IN SEVERAL LOCATIONS...ESPECIALLY IN THE WEST. SHAPED POPS THIS
MORNING INTO THIS AFTERNOON TOWARDS A HRRR AND HIRESW-ARW BLEND.
WITH KFCX WSR-88D LOOP SHOWING LIGHT MOISTURE SPREADING NORTHEAST
ALONG THE BLUE RIDGE...EXPANDED LIGHT POPS FURTHER EAST THIS
MORNING INTO THIS AFTERNOON. THE 12Z RNK SOUNDING DID SHOWED A
SOUTHWEST 50 KNOT JET AROUND 800 MB WITH A PWAT AT 0.63 INCHES.
WILL HOLD WITH CURRENT WIND ADVISORY UNTIL 7 PM ACROSS HIGHER
TERRAIN WITH THE LOW LEVEL JET ROTATING NORTHEAST THIS MORNING
INTO THIS AFTERNOON. POSTED SPS FOR FOG AND LOW CLOUDS ALONG
INTERSTATE 77 FOR THIS MORNING. MORE CHANGES LATER THIS MORNING...
AS OF 415 AM EST MONDAY...
AWAITING THE LONG ADVERTISED COLD FRONT THIS PERIOD.
COMBINATION OF SYNOPTIC SCALE...GFS/ECMWF/NAM...AND SHORT RANGE
MESOSCALE MODELS...HRRR/RNK-WRF/NCEP-WRF...SHOW CONTINUED SLOWER
PROGRESSION AND WEAKENING OF THE CURRENTLY IMPRESSIVE SYSTEM
ACROSS THE WESTERN TENNESSEE VALLEY. JUST A FEW RUNS BACK OF THE
SYNOPTIC SCALE MODELS WOULD HAVE HAD THE ASSOCIATED LINE OF
CONVECTIVE SHOWERS IN OUR CWA AT 12Z THIS MORNING. INSTEAD...THIS
LINE IS SEVERAL HUNDRED MILES STILL WEST OF THE CWA. LATEST
PROJECTIONS DO NOT SHOW THIS LINE OF CONVECTION REACHING THE
WESTERN PARTS OF THE CWA UNTIL LATE MORNING...THEN SPREADING EAST
DURING THE AFTERNOON/EARLY EVENING. CONSIDERABLE WEAKENING IS ALSO
INDICATED AS THE ACTIVITY ATTEMPTS TO PUSH EAST OF THE BLUE RIDGE
AND THE PARENT UPPER LOW TRACKS NORTH-NORTHEAST TOWARD THE GREAT
LAKES. THIS HAS RESULTED IN SLOWER TIMING OF THE HIGHER POPS INTO
THE CWA AND REDUCED POPS ACROSS EASTERN AREAS.
MEANWHILE...A WARM ADVECTION WING HAS DEVELOPED ACROSS THE
SOUTHEAST PART OF THE CWA INTO CENTRAL NC/SC...AIDED BY
INCREASINGLY MOIST SOUTHERLY UPSLOPE FLOW ALONG THE BLUE RIDGE. AS
A RESULT...SCATTERED SPRINKLES/LIGHT RAIN SHOWERS/DRIZZLE EVIDENT
IN THESE AREAS. MESOSCALE MODELS SHOW THIS HOLDING STEADFAST AND
TRACKING NORTHEAST INTO THE SHENANDOAH VALLEY BY EARLY AFTERNOON
AS THE LINE OF SHOWERS APPROACHES FROM THE WEST. STILL WILL HAVE
CATEGORICAL TO LIKELY POPS ACROSS MOST OF THE CWA THROUGH THE DAY
FROM WEST-EAST AS FEEL MOST LOCATIONS WILL AT LEAST SEE 0.01 INCH.
WITH RESPECT TO THE WIND CONCERN...THE STRONGEST 850MB WINDS ARE
PROGGED TO REACH THE WESTERN BORDER AROUND 12Z...THEN TRANSLATE
NNE WITH THE PARENT UPPER LOW. WINDS DO NOT REALLY SHIFT
APPRECIABLY TO THE WEST/NORTHWEST UNTIL EVENING. CURRENT WIND
ADVISORY IN EFFECT FOR THE HIGHER TERRAIN UNTIL 00Z TUE. WILL
LEAVE AS IS...BUT MAIN CONCERN REMAINS THAT OF WINDS AHEAD OF THE
SHOWERS AND ASSOCIATED WITH THE MORNING LLJ...NOT WINDS BEHIND THE
SHOWERS/TROUGH. MOMENTUM TRANSFER INDICATED VIA BUFKIT IS
POOR...BUT AM OBSERVING WINDS GUSTS IN THE 35-45 MPH RANGE ACROSS
MERCER/TAZEWELL AND ALLEGHANY NC COUNTIES.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THROUGH THE
PERIOD...BUT NOT AS WARM AS PREVIOUS DAYS THANKS TO CLOUDS AND
PRECIPITATION. STARTING OUT UNSEASONABLY MILD THIS MORNING WITH
MANY AREAS IN THE LOWER TO MIDDLE 60S. TUESDAY MORNING SHOULD BE A
TAD COOLER WITH CLEARING...SLIGHTLY DRIER AIR...HIGH
PRESSURE...AND LESS WIND...BUT NONETHELESS STILL WELL ABOVE NORMAL
WITH NO FREEZING TEMPERATURES INDICATED UNTIL LATE IN THE WEEK.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 236 AM EST MONDAY...
AFTER A BREEZY MORNING TUESDAY...A WEAK AREA OF HIGH PRESSURE WILL
BUILD EAST UNDER SHORT WAVE RIDGING. DESPITE COOLER AIR WORKING INTO
THE REGION...TUESDAY`S AFTERNOON HIGHS WILL REMAIN WARMER THAN
NORMAL WITH UPPER 50S WEST AND MID TO UPPER 60S EAST. THIS AREA OF
HIGH PRESSURE WILL MOVE OVER THE MID ATLANTIC REGION...WEDGING SOUTH
INTO THE CAROLINAS TUESDAY NIGHT. LIGHT SOUTHEASTERLY LOW LEVEL FLOW
AND INCREASING CLOUDS COVER FROM THE SOUTH WILL PRODUCE UNIFORM
TEMPERATURES IN THE UPPER 50S TO LOWER 60S WEDNESDAY. A DISTURBANCE
WILL MOVE OUT OF THE GULF ON WEDNESDAY AND TRACK ALONG THE SOUTHERN
APPALACHIANS WEDNESDAY NIGHT INTO THURSDAY. THIS SYSTEM WILL BRING
ABOUT AN INCH OF RAIN TO AREAS ALONG AND EAST OF THE BLUE RIDGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 1230 PM EST SUNDAY...
THE LONG RANGE FEATURES THE FIRST BIG ARCTIC PUSH INTO THE REGION
FOR QUITE SOME TIME...ALTHOUGH THE COLD AIR WONT STICK AROUND LONG.
THE PERIOD STARTS WARM WITH +11C 850MB TEMPS AHEAD OF AN APPROACHING
COLD FRONT AND DIGGING TROUGH. EXPECT SHOWERS AHEAD OF THE FRONT
THURSDAY INTO FRIDAY. EXACTLY HOW MUCH RAIN WILL FALL ACROSS OUR
REGION WILL DEPEND ON HOW DEEP THE TROUGH TO OUR WEST DIGS...FOR
RIGHT NOW IT LOOKS LIKE AREAS ALONG AND EAST OF THE BLUE RIDGE WILL
SEE THE MOST RAIN. THE COLD FRONT WILL PUSH THROUGH THE AREA
SOMETIME FRIDAY MORNING PUSHING THE RAIN OUT WITH IT.
BEHIND THE COLD FRONT TEMPS WILL FALL QUICKLY. AS THE TROUGH SWINGS
THROUGH THE REGION 850MB TEMPS WILL DROP DOWN TO -10 TO -12C BY
SATURDAY MORNING. WITH SUFFICIENT LOW LEVEL MOISTURE...THERE IS A
GOOD CHANCE WE WILL SEE NORTHWEST FLOW SNOW SHOWERS ALONG THE
FAVORED WESTERN RIDGES FRIDAY NIGHT AND THROUGH THE DAY SATURDAY.
HIGH TEMPS SATURDAY WILL RUN 5-10 DEGREES BELOW NORMAL WITH MANY
MOUNTAIN LOCATIONS STRUGGLING TO REACH THE FREEZING MARK.
BY SUNDAY THE TROUGH MOVES OFF TO OUR EAST AND ALONG WITH IT THE
COLD AIR. STRONG HIGH PRESSURE BUILDS IN AND WILL MOVE JUST TO OUR
EAST SUNDAY NIGHT/MONDAY MORNING. THE W/SW FLOW WILL ONCE AGAIN PULL
WARM AIR INTO THE REGION AND WE RETURN TO ABOVE NORMAL TEMPS.
&&
.AVIATION /14Z MONDAY THROUGH FRIDAY/...
AS OF 645 AM EST MONDAY...
MOISTURE ADVECTION AHEAD OF THE STRONG WEATHER SYSTEM TO OUR WEST
HAS RESULTED IN LOWERING CIGS OVERNIGHT...ESPECIALLY ALONG AND
SOUTHEAST OF THE BLUE RIDGE. WIDESPREAD MVFR-IFR CIGS FROM NORTHWEST
NC NORTHEAST TOWARD KLYH. THESE CEILINGS HAVE STILL NOTE QUITE
SPREAD TO THE NORTHWEST YET...BUT KBLF IS ON THE EDGE OF BECOMING
MVFR/IFR...AS IS KLWB. DECOUPLING EARLIER ACROSS PARTS OF THE
PIEDMONT AND THE GREENBRIER VALLEY ALLOWED FOR BRIEF IFR-LIFR BR
AND ASSOCIATED CIGS. HOWEVER...THIS HAS DISPERSED NOW WITH
STRONGER SOUTHERLY FLOW AND CLOUDS IN ADVANCE OF THE SYNOPTIC
SCALE SYSTEM TO THE WEST.
WINDS HAVE BEGUN TO BACK TO THE SSE AS THE UPPER TROUGH/FRONT
APPROACH. AS EXPECTED...KBLF HAS BEEN GUSTING INTO THE 20-28KT
RANGE MUCH OF THE NIGHT. STRONGEST LLJ WILL APPROACH THE WESTERN
BORDER OF THE CWA DURING THE MID-MORNING...THEN LIFT NNE TOWARD
THE OH VALLEY/WESTERN PA. LOW END GUSTS ARE POSSIBLE FURTHER
EAST...BUT PROBABILITY FOR THIS APPEARS TO BE LOW. WILL CONTINUE
WITH THE LLWS FOR KLWB/KBCB WHERE WINDS HAVE DECOUPLED AND THERE
IS A RAPID INCREASE IN SPEED JUST OFF THE SURFACE. MORNING
SOUNDING FROM KRNK SHOWED AN ALMOST 50KT INCREASE IN WINDS BETWEEN
THE SURFACE AND 850MB.
MODELS HAVE CONTINUED TO SLOW DOWN THE ARRIVAL OF THE SYNOPTIC
SYSTEM AND ASSOCIATED NARROW LINE OF SHOWERS. WHILE SOME -SHRA OR
-DZ HAS BEEN NOTED ALONG THE SOUTHWEST PARTS OF THE BLUE RIDGE
INTO SOUTHWEST VA...BONAFIDE -SHRA WILL LIKELY NOT REACH THE
WESTERN PART OF THE CWA UNTIL MID OR LATE MORNING. MOST MODELS
ALSO SHOW A DISSIPATION OF ACTIVITY AS IT ATTEMPTS TO SPREAD
FURTHER EAST. WOULD EXPECT MVFR-IFR CIGS TO HOLD MUCH OF THE DAY
UNTIL THE SHOWERS ARRIVE...IMPROVING TO VFR AFT 00Z EAST OF THE
BLUE RIDGE WITH INCREASING DOWNSLOPE WINDS...BUT REMAINING MVFR TO
THE WEST. VISIBILITIES SHOULD GENERALLY REMAIN MVFR OR BETTER
THROUGH THE DAY AS RAIN SHOWERS ARE EXPECTED TO BE LIGHT. WINDS
BEHIND THE FRONT WILL BECOME WSW-W WITH SPEEDS MOSTLY BETWEEN
8-10KTS AND LOW END GUSTS UP UNTIL ABOUT 04Z.
MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID PERIOD.
.EXTENDED AVIATION DISCUSSION...
WIDESPREAD VFR UNDER DIMINISHING WINDS WILL OCCUR UNDER WEAK HIGH
PRESSURE TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT WITH AN
ASSOCIATED AREA OF LOW PRESSURE LOOKS TO BRING MORE IN THE WAY OF
WIDESPREAD SUB- VFR IN RAIN AND LOWER CIGS LATE WEDNESDAY NIGHT
INTO THURSDAY EVENING. SHOULD EVOLVE INTO VFR DURING FRIDAY AS
DEEP MOISTURE EXITS AND AN UPSTREAM UPPER DISTURBANCE APPROACHES.
HOWEVER LINGERING UPSLOPE FLOW LIKELY TO KEEP MVFR CEILINGS IN
PLACE ACROSS THE SOUTHEAST WEST VA SITES FOR MUCH OF THE DAY.
&&
.CLIMATE...
AS OF 745 PM EST SUNDAY...
RECORD HIGH TEMPERATURES WERE SET TODAY (12/13) AT BOTH DANVILLE
VA AND BLUEFIELD WV. SEE THE LATEST WBCRERRNK FOR ADDED DETAILS.
RECORD HIGH TEMPERATURES FOR....
DEC 14
BLACKSBURG | 70 IN 1984 |
BLUEFIELD | 68 IN 1984 |
DANVILLE | 74 IN 1948 |
LYNCHBURG | 70 IN 1948 |
ROANOKE | 73 IN 1927 |
RECORD HIGH MINIMUM TEMPERATURES FOR....
BLACKSBURG | 49 IN 1991 |
BLUEFIELD | 53 IN 1984 |
DANVILLE | 53 IN 1991 |
LYNCHBURG | 55 IN 1901 |
ROANOKE | 60 IN 1927 |
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ007-009-010-
015.
NC...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ001-018.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ042.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...RCS
LONG TERM...CF
AVIATION...JH/KK/RAB
CLIMATE...CF/JH/RAB/WP
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
1228 PM MST MON DEC 14 2015
.SYNOPSIS...
A FAST MOVING WEATHER SYSTEM THAT BROUGHT DESERT RAIN AND MOUNTAIN
SNOW TO ARIZONA TODAY WILL RAPIDLY MOVE OUT OF THE AREA TONIGHT.
BEHIND THIS SYSTEM VERY COLD AIR WILL SETTLE OVER THE REGION...WITH
WELL BELOW NORMAL HIGH TEMPERATURES AND SUB-FREEZING LOW
TEMPERATURES LIKELY FOR MUCH OF THIS WEEK. DRY AND COLD WEATHER WILL
PERSIST INTO THE WEEKEND.
&&
.DISCUSSION...
UPPER LOW CONTINUES TO SLOWLY CIRCULATE ACROSS NEVADA/UTAH THIS
AFTERNOON ALTHOUGH THE MAIN TROUGH AXIS HAS SHIFTED EAST. THE MAIN
BAND OF PRECIPITATION HAS MIGRATED EAST OF PHOENIX AND IS NOW A
RAIN/SNOW MIX ABOVE 4500 FEET /WITH SOME LOCALIZED LIGHT SNOW
POSSIBLE DOWN TO 3500 FEET/. ALSO STARTING TO SEE SOME VERY ISOLATED
INSTABILITY SHOWERS ACROSS THE WESTERN FORECAST AREA AS A SECONDARY
SHORTWAVE TROUGH IS MAKING ITS WAY SOUTHWARD. THIS TROUGH IS ALSO
ENTERING AN AIRMASS WHERE DEWPOINTS HAVE DROPPED CONSIDERABLY INTO
THE TEENS AND 20S. THUS FAR THERE HAVEN`T BEEN ANY ADDITIONAL
RAINFALL REPORTS ACROSS SOUTHEAST CALIFORNIA OR SOUTHWEST
ARIZONA...BUT IT CERTAINLY WARRANTS SOME SORT OF MENTION IN THE
FORECAST NONETHELESS. MEANWHILE...TEMPS CONTINUE TO STRUGGLE TODAY.
MID DAY READINGS IN THE UPPER 40S TO LOWER 50S ARE COMMON ACROSS THE
DESERTS AND THIS WILL BE PAR FOR THE COURSE THE NEXT FEW DAYS.
IN THE VERY SHORT TERM...PRECIP WILL GRADUALLY TAPER OFF THIS EVENING
AND OVERNIGHT. GIVEN THE RELATIVELY WIDESPREAD RAINFALL OF 0.1-0.3
INCHES ACROSS THE AREA...FOG IS A BIT OF A CONCERN. ALWAYS TOUGH TO
DETERMINE IF DRY ADVECTION FROM THE NORTHWEST AND ELEVATED MIXING
WILL WIN THE BATTLE VS. LINGERING LOW LEVEL MOISTURE. ALSO OF CONCERN
IS THE POSSIBILITY OF SOME HIGH CLOUDS MOVING INTO THE AREA LATE
TONIGHT WHICH COULD MITIGATE THE FOG THREAT. GIVEN QUITE A FEW MODELS
SUGGESTING ELEVATED DEWPOINTS THROUGH 12Z...I`M GOING TO INTRODUCE A
RELATIVELY LARGE AREA OF PATCHY FOG FOR MARICOPA AND NW PINAL
COUNTIES /GENERALLY THE ONLY AREAS THAT SAW APPRECIABLE RAINFALL/.
SOUTHERN GILA COUNTY WILL LIKELY STAY CLOUDY OVERNIGHT BUT COULD SEE
SOME VALLEY FOG IN SOME SPOTS.
TEMPERATURES...COLD TO SAY THE LEAST. TONIGHT WILL SEE THE BEGINNING
OF AT LEAST 2 OR 3 NIGHTS WHERE TEMPS APPROACH OR DROP BELOW FREEZING
IN THE OUTLYING DESERT AREAS. LATEST BLENDED RAW GUIDANCE MAINTAINS
TEMPS IN THE MID 30S ACROSS THE OVERWHELMING MAJORITY OF THE LOWER
DESERT LOCALES ALTHOUGH THE TYPICAL COLD SPOTS IN NORTHWEST PINAL
COUNTY COULD FALL INTO THE UPPER 20S. SHOULD NOT SEE WIDESPREAD
FREEZES LATE TONIGHT. CERTAINLY A DIFFERENT STORY WEDNESDAY AND
THURSDAY MORNINGS AS THE COLDEST TEMPS OF THE SEASON THUS FAR ARE
EXPECTED. WITH THE NORMALLY WARM AREAS OF DOWNTOWN PHOENIX FORECAST
TO DROP INTO THE MID 30S...LOW TO MID 20S SEEMS LIKE A LOCK FOR THE
OUTLYING DESERTS...THUS WE ISSUED A FREEZE WATCH WEDNESDAY MORNING
AND THURSDAY MORNING. ELECTED NOT TO INCLUDE YUMA OR SOUTHEAST
CALIFORNIA AS WINDS SHOULD STAY ELEVATED AND THE BULK OF THE VERY
COLD AIR LOOKS POISED TO REMAIN CONFINED TO ARIZONA. SOME WARMING IS
FORECAST LATE IN THE WEEK AS WEAK UPPER LEVEL SHORTWAVE RIDGING
BEGINS TO TAKE HOLD OVER THE AREA.
FRIDAY INTO THE FIRST PART OF THE WEEKEND...HIGH PRESSURE ALOFT WILL
BUILD ACROSS THE DESERT SOUTHWEST LEADING TO DRY CONDITIONS AND
WARMER HIGH TEMPERATURES. HIGHS FRIDAY WILL REACH INTO THE MID 60S
OVER MOST OF THE DESERTS...AND THEY WILL CLIMB FURTHER AND INTO THE
UPPER 60S TO AROUND 70 ON SATURDAY. INCREASING HIGH CLOUDS ARE
EXPECTED SATURDAY FOR PARTLY SUNNY SKIES.
ANOTHER CHANGE IN THE WEATHER PATTERN IS EXPECTED STARTING SUNDAY AS
ANOTHER PACIFIC LOW PRESSURE SYSTEM IS FORECAST TO MOVE INTO THE
DESERT SOUTHWEST BRINGING INCREASING CLOUDS...MOISTURE AND A SLIGHT
CHANCE FOR SHOWERS OVER SERN CA AND SOUTHWEST AZ BY SUNDAY
AFTERNOON. THIS IS SUPPORTED BY NAEFS ENSEMBLE GUIDANCE AS WELL AS
LATEST GFS AND ECMWF OPERATIONAL RUNS. COOLER...WET AND UNSETTLED
CONDITIONS WILL PERSIST INTO THE MIDDLE OF NEXT WEEK.
&&
.AVIATION... SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND
KSDL...
THROUGH 19Z MON...COLD FRONTAL PASSAGE ARND 16Z MON. BKN CLDS 4-6
THSD AGL WITH SCT RAIN SHWRS. SE WIND 6 TO 10 KNOTS...SHIFTING TO
THE WEST 15 TO 25 KNOTS WI FRONTAL PASSAGE. FROM 19Z MON TO 02Z
TUE...CLDS LIFTING TO BKN 6-7 THSD AGL WITH ISOLD R SHWR. WEST WIND
15 TO 25 KNOTS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
THROUGH 16Z MON...COLD FRONTAL PASSAGE. BKN CLDS 6-8 THSD AGL WITH
ISOLATED R SHWR. WEST WIND 15 TO 25 KNOTS. FROM 16Z MON TO 02Z
TUE...SCT CLDS 6 TO 8 THSD AGL. NW WND 15 TO 20 KNOTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
WEDNESDAY THROUGH SUNDAY...
DRY WEST TO NORTHWEST FLOW ALOFT. PARTLY CLOUDY AT TIMES. LIGHT
NORTHEAST WIND 5 TO 10 MPH. MINIMUM RELATIVE HUMIDITY GENERALLY FROM
20 TO 30 PERCENT. BELOW NORMAL TEMPERATURES WEDNESDAY AND THURSDAY...
WARMING TO NEAR NORMAL FRIDAY AND THE WEEKEND.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FREEZE WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING FOR
AZZ020>023-026>028.
FREEZE WATCH FROM WEDNESDAY EVENING THROUGH THURSDAY MORNING FOR
AZZ020>023-026>028.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...LEINS/CB
AVIATION...VASQUEZ
FIRE WEATHER...VASQUEZ
Area Forecast Discussion
National Weather Service Sacramento CA
1034 AM PST MON DEC 14 2015
.SYNOPSIS...
Pacific storm has exited the region. Mostly dry weather with
seasonal temperatures today through Wednesday. Wet pattern returns
Thursday into next week.
&&
.DISCUSSION...
Only made some minor changes to today`s forecast. The HRRR shows
lingering showers this morning, but mainly over the NorCal
coastline so have reduced the mention of showers in our CWA.
Expect dry & mild weather into midweek with a wet pattern
returning by the end of the week. JBB
.Previous Discussion...
Other than some early morning patchy frost in the valley, and a
few lingering snow showers in the mountains today, rather benign
weather is expected the next several days across the region. Cool
overnight temperatures are expected, but daytime temperatures will
be close to average for mid-December. Breezy northerly winds will
develop today across the Central Valley and continue into Tuesday
before diminishing on Wednesday.
Moisture moving over the eastern Pacific may begin to spill into
far northern California as early as Wednesday night bringing an
increase in clouds to the region along with a chance for light
precipitation across the northern mountains and northern
Sacramento Valley heading into Thursday.
&&
.EXTENDED DISCUSSION (Friday THROUGH Monday)
Overrunning precip may bring some rain across much of the area
Friday. Models agree that the trough tries to cutoff as the
access reaches 125W over the weekend; however, the GFS is about
12 hours quicker. Both depict a decent shot of precipitation and
lowering snow levels, but as good as if the system doesn`t cut
off. Slightly cyclonic northwest flow behind the main trough
brings a better chance for precipitation Monday. JClapp
&&
.AVIATION...
VFR conditions through the period for TAF sites. Breezy northerly
winds across the Sac and San Joaquin valleys through the evening
hours with gusts 25-30 kts possible.
&&
.STO Watches/Warnings/Advisories...
None.
&&
$$
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
315 PM EST MON DEC 14 2015
.DISCUSSION...
TONIGHT-TUESDAY...
A WELL DVLPD STORM SYSTEM OVER THE MIDWEST/GREAT LAKES REGION WILL RACE
INTO THE CANADIAN MARITIMES...PULLED BY A 150-170KT JET OVER NEW
ENGLAND/ERN CANADA...AND PUSHED BY AN 80-100KT JET STREAK THAT SPANS THE
OH RIVER VALLEY TO THE DESERT SW. WHILE THIS LOW WILL DRAG A COLD FRONT
INTO THE ERN CONUS...IT WILL STEADILY OUTRUN THE SRN PORTION OF THE
FRONTAL TROF AS THE LATTER PLOWS INTO THE WRN FLANK OF A DEEP LYR RIDGE
CENTERED BTWN BERMUDA AND THE BAHAMAS. THE FRONT WILL HAVE ENOUGH FORWARD
MOMENTUM TO PUSH INTO THE BIG BEND/CAROLINA COAST...BUT WILL STALL WELL
N OF THE I-4 CORRIDOR.
THE SE CONUS RADAR MOSAIC REFLECTS A RAPIDLY DETERIORATING FRONTAL
RAINBAND OVER THE FL PANHANDLE AND THE DEEP SOUTH. RAP ANALYSIS
SHOWS MID LVL VORTICITY/UPR LVL DIVERGENCE AHEAD OF THE FRONT IS
WEAK AT BEST...WITH H50 TEMPS BTWN -3/-4C AND LAPSE RATES BLO
5.0C/KM THRU THE H85-H50 LYR. H85-H70 LAPSE RATES DO STEEPEN TO
6.0-6.5C/KM IMMEDIATELY AHEAD OF THE FRONT...BUT THESE ARE STILL
BACK OVER THE CENTRAL GOMEX AND WILL MODIFY AS THEY MIX IN WITH THE
TEPID MID LVL OVERHEAD. DEEP MOISTURE POOLING WITHIN THE FRONTAL
TROF WILL WORK ITS WAY INTO CENTRAL FL AS THE FRONT STALLS TO THE
N...BUT WILL DO SO IN A "TOP DOWN" MANNER THAT RARELY RESULTS IN
ANYTHING MORE THAN A LOW COVERAGE SHRA REGIME WITH LIMITED POTENTIAL
FOR DEEP CONVECTION.
FOG/LOW STRATUS POTENTIAL WILL BE HIGH OVERNIGHT AS FL REMAINS IN
THE WARM SECTOR OF THE STALLING FRONTAL BOUNDARY...LCL DENSE FOG
PSBL ALONG AND N OF THE I-4 CORRIDOR IN THE PREDAWN HRS. TUE PRECIP
WILL BE LIMITED TO A CHC OF SHRAS ALONG AND N OF THE I-4 CORRIDOR...
SLGT CHC S OF I-4. S/SW FLOW REGIME AND INCREASING CLOUDS WILL KEEP
MIN TEMPS TONIGHT IN THE M/U60S...ARND 15F ABV AVG. HIGHER CLOUD AND
PRECIP POTENTIAL ALONG AND N OF I-4 WILL KEEP MAX TEMPS TUE IN THE
M/U70S...S OF I-4 MAX TEMPS IN THE L/M80S...STILL 5-10F ABV AVG
AREAWIDE.
WED...
AFTER MORNING FOG AND STRATUS BURNS OFF SHOULD SEE ANOTHER WARM
AFTERNOON WITH NEAR RECORD HIGH TEMPERATURES INTO THE MID 80S WITH
CONTINUED SOUTHERLY FLOW. SFC WARM FRONT WILL LIFT INTO S GA AS SFC
LOW BEGINS TO DEVELOP ACROSS SRN LA AHEAD OF PLAINS MID LVL TROUGH.
WILL KEEP DIURNAL SHOWER CHANCES IN THE 20-30 PCT RANGE...WITH
HIGHER CHANCES ACROSS NRN AREAS IN THE AFTERNOON.
THU...
DEEPENING L/W TROUGH ACROSS THE ERN CONUS AND STRENGTHENING 140 KT
JET FROM S TX INTO THE TN VALLEY WILL INDUCE CYCLOGENESIS N GA THU
MORNING WHICH WILL MOVE QUICKLY NE THROUGH THE DAY. LOW LVL
SOUTHERLY FLOW WILL VEER TO SW INTO LATE AFTERNOON WITH DEEPENING
PREFRONTAL MOISTURE AHEAD OF THE FRONT MOVING TWD THE FL BIG BEND.
WILL FCST HIGHS INTO THE MID 80S ALL AREAS WITH A LOW CHANCE FOR
PREFRONTAL SHOWERS IN THE 20-30 PCT RANGE.
THU NIGHT AND FRIDAY...
DEEPER CONVECTION IS EXPECTED JUST AHEAD OF THE SFC COLD FRONT WHICH
WILL MOVE TOWARD THE AREA LATE THU NIGHT AND ACROSS E CENTRAL FL ON
FRIDAY. ATMOSPHERE SHOULD SUPPORT THUNDER THREAT WITH STRONG JET
INDUCED LIFT AND FRONTAL FORCING THU NIGHT INTO FRI. WILL KEEP POPS
IN THE LIKELY RANGE FRIDAY AS THE FRONT MOVES THROUGH WITH NUMEROUS
SHOWERS AND A SLIGHT CHANCE FOR STORMS. ECM APPEARS TO HAVE SPED UP
THE FRONTAL PUSH INTO THE PENINSULA...AND IS NOW MORE IN LINE WITH
THE GFS.
FRIDAY NIGHT THROUGH MONDAY...
FRONT WILL CLEAR THE AREA BY FRIDAY EVENING WITH SOME OF THE COOLEST
AIR OF THE SEASON ARRIVING FOR THE FIRST HALF OF THE WEEKEND.
NORTHERLY WINDS WILL ALLOW TEMPERATURES TO DROP INTO THE UPPER 40S
TO LOWER 50S ACROSS NRN SECTIONS FRIDAY NIGHT TO THE UPPER 50S TO
LOWER 60S S CSTL FRIDAY NIGHT AND THEN REMAIN COOL IN THE MID TO
UPPER 60S FOR HIGHS OVER MUCH OF E CENTRAL FL ON SATURDAY. SKIES
WILL BE MOSTLY SUNNY FRIDAY WITH HIGH PRESSURE BUILDING IN ACROSS
THE SE STATES. THE SFC HIGH WILL MOVE TOWARD THE CAROLINA COAST
SUNDAY INTO MONDAY WITH WINDS GRADUALLY VEERING TO ONSHORE. AFTER
ONE MORE COOL NIGHT SATURDAY NIGHT IN THE 40S INLAND TO 50S NEAR THE
COAST...LOWS WILL MODERATE INTO EARLY NEXT WEEK WITH DEVELOPING
ONSHORE FLOW. HIGHS SUNDAY AROUND 70 WILL WARM INTO THE MID TO UPPER
70S BY MONDAY OF NEXT WEEK.
&&
.AVIATION...THRU 15/18Z
SFC WNDS: THRU 14/22Z...S/SW 9-13KTS WITH OCNL G20KTS. BTWN 14/22Z-
15/02Z...BCMG S/SW 2-4KTS. AFT 15/14Z...S OF KMLB-KGIF BCMG S/SE
8-12KTS...N OF KMLB-KGIF BCMG S/SW 6-10KTS.
VSBY/WX/CIGS: THRU 15/06Z...PREVAILING VFR WITH LCL MVFR CIGS BTWN
FL020-030...BRIEF MVFR VSBYS IN ISOLD SHRAS S OF KISM-KTIX THRU
15/00Z. BTWN 15/06Z-15/14Z...INTERIOR SITES PREVAILING IFR CIGS WITH
AREAS LIFR CIGS/VSBYS IN BR/FG...COASTAL SITES PREVAILING VFR CIGS
BTWN FL040-060 WITH PTCHY MVFR CIGS/VSBYS IN BR. AFT 15/14Z...CHC
MVFR SHRAS N OF KISM-KTIX...SLGT CHC S OF KISM-KTIX.
&&
.MARINE...
TONIGHT-TUESDAY...LCL PGRAD WILL CONT TO SLACKEN OVERNIGHT AS THE
FRONTAL BNDRY PUSHING ACRS THE DEEP SOUTH/NE GOMEX STALLS ACRS THE
BIG BEND/CAROLINA COAST. GENTLE TO MODERATE SRLY BREEZE BCMG A LIGHT
TO GENTLE S/SW BREEZE OVERNIGHT...CONTG THRU THE DAY TUE. SEAS 3-4FT
NEARSHORE AND 4-5FT OFFSHORE...SUBSIDING TO 2-3FT NEARSHORE AND
3-4FT OFFSHORE.
TUE NIGHT-SAT...S/SE WINDS TUE NIGHT-WED WILL GENERALLY BE AROUND 10
KNOTS OR LESS WITH SEAS 3-4 FT TUE DECREASING TO 2-3 FT WED.
SOUTHERLY WINDS WILL INCREASE THU TO SCEC LEVELS OFFSHORE...AND
BECOME SW THU NIGHT. A STRONG COLD FRONT WILL MOVE ACROSS THE LCL
WATERS FRIDAY WITH INCREASING NW-N WINDS LATE IN THE DAY. ADVISORY
CONDITIONS EXPECTED FRI NIGHT INTO SATURDAY WITH NORTHERLY WINDS
INCREASING TO 20-25 KNOTS AND GUSTY.
&&
.PRELIMINARY POINT TEMPS...
DAB 66 75 67 81 / 10 30 20 30
MCO 66 81 68 84 / 10 20 20 30
MLB 67 81 69 82 / 10 20 20 20
VRB 67 82 69 83 / 10 20 20 20
LEE 68 78 67 82 / 10 30 20 30
SFB 66 79 68 83 / 10 30 20 30
ORL 66 80 68 83 / 10 30 20 30
FPR 68 82 69 83 / 10 20 20 20
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...BRAGAW
LONG TERM/IMPACT WX...CRISTALDI
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
257 PM EST MON DEC 14 2015
.SYNOPSIS...
20Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS AND ACTIVE UPPER LEVEL
PATTERN OVER THE CONUS. LOOKING OUT WEST WE FIND DEEP AND SHARP
TROUGHING PIVOTING EASTWARD FROM THE PACIFIC COAST INTO THE INTER-
MOUNTAIN WEST. NORTHERN STREAM FLOW THEN EXITS THIS TROUGH AND
LIFTS UP INTO SOUTHERN CANADA BEFORE TURNING EASTWARD INTO A MORE
ZONAL PATTERN ALL THE WAY TO NOVA SCOTIA. REMOVED FROM THE
NORTHERN STREAM FLOW WE FIND A POTENT UPPER LEVEL LOW QUICKLY
PIVOTING TO THE NORTHEAST INTO THE GREAT LAKES REGION/UPPER
MIDWEST. A SURFACE REFLECTION LOW UNDERNEATH THIS SYSTEM IS
LIFTING THROUGH THE UPPER MIDWEST WITH A TRAILING COLD FRONT ALL
THE WAY SOUTH TO THE NORTHEAST GULF OF MEXICO. WV IMAGERY SHOWS A
DEEP SOUTHERLY MOISTURE PLUME SPREADING NORTHWARD AHEAD OF THIS
FRONT AND INTO THE PARENT SYSTEM. PLENTY OF INCLEMENT WEATHER
ONGOING FROM THE GREAT LAKES SOUTHWARD ALONG THE FRONT TO THE
FLORIDA BIG BEND REGION.
A LITTLE CLOSER TO HOME...WE ARE STILL OUT AHEAD OF THIS COLD FRONT
WITHIN AN UNSEASONABLE WARM AND HUMID AIRMASS. THE STRONG UPPER
RIDGE THAT DOMINATED OUR WEATHER THIS PAST WEEKEND STILL HAS SOME
INFLUENCE ON THE REGION...ESPECIALLY THE CENTRAL AND SOUTHERN PARTS
OF THE PENINSULA...HOWEVER A GLANCE AT THE 12Z KTBW SOUNDING
PROFILE SHOWS THAT THE DEPTH AND STRENGTH OF THE RIDGE AND
RESULTING OVERALL SUPPRESSION HAS DECREASED SINCE SUNDAY. THE
SUBSIDENCE INVERSION IS NOW MUCH HIGHER LOCATED AROUND 600MB
COMPARED TO BETWEEN 850-700MB SUNDAY MORNING. AS A RESULT...THE
COLUMN PW HAS ALSO COME UP SUBSTANTIALLY...FROM WELL UNDER 1"
SUNDAY MORNING TO AROUND 1.5" THIS MORNING.
AT THE SURFACE...MAIN RIDGE OF HIGH PRESSURE HAS SHIFTED OFF THE
CAROLINA COAST INTO THE WESTERN ATLANTIC...WITH AN EXTENSION OF THE
RIDGE OFF TO THE SOUTHWEST ACROSS THE CENTRAL/SOUTHERN FLORIDA
PENINSULA/SW GULF OF MEXICO. OUR LOW LEVEL FLOW HAS VEERED TO A MORE
SOUTHERLY DIRECTION BETWEEN THIS RIDGE AND THE SLOWLY APPROACHING
COLD FRONT...CURRENTLY LOCATED OVER THE FL BIG BEND REGION AND
NORTHEAST GULF.
REST OF TODAY...FORECAST AREA WILL REMAIN WITHIN THE WARM SECTOR
AHEAD OF THE FRONT. EVEN WITH PLENTY OF CLOUDS...THERE ARE ALSO
PLENTY OF SUNNY BREAKS RESULTING IN ANOTHER WELL ABOVE AVERAGE
DAY IN TERMS OF TEMPERATURE. THE LOW LEVEL POTENTIAL OF THE
ATMOSPHERE IN TERMS OF TEMPERATURES IS VERY HIGH...WITH 850MB
TEMPERATURES AROUND 16C (WELL OVER THE 90TH PERCENTILE FOR MID-
DECEMBER). IN FACT THE 12Z KTBW SOUNDING SHOWED A 16C TEMPERATURE
AS HIGH AS 825MB. ALONG THE SAME SUBJECT...TO SHOW JUST HOW
ABNORMAL THE WARMTH OF THE COLUMN IS OVER OUR HEADS...THE 12Z KTBW
SOUNDING ALSO MEASURED A 700MB TEMPERATURE OF 9C (WELL OVER THE
90TH PERCENTILE FOR MID- DECEMBER)...AND THE 500MB TEMPERATURE WAS
MEASURED AT -3.1C. THIS VALUE TIES THE SECOND WARMEST EVER 500MB
TEMP OBSERVED FOR KTBW IN DECEMBER. ONE OTHER TIME...-2.1C WAS
OBSERVED ON DECEMBER 7TH. VERY IMPRESSIVE VALUES INDEED.
TEMPERATURES ARE CURRENTLY PEAKING IN THE LOW/MID 80S AWAY FROM
THE IMMEDIATE COAST. WIND HAVE COME AROUND TO THE SOUTH...WITH A
SLIGHT ONSHORE COMPONENT AT THE COAST..AND THIS ONSHORE COMPONENT
OFF THE "RELATIVELY" COOLER SHELF WATERS SHOULD CONTINUE TO KEEP
TEMPS AT THE BEACHES DOWN IN THE MID/UPPER 70S.
DUE TO THE DEEPER MOISTURE IN PLACE...A FEW WDLY SCT SHOWERS WILL
BE POSSIBLE THROUGH EARLY EVENING ACROSS MAINLY THE INTERIOR
ZONES THIS LATE AFTERNOON/EARLY EVENING...BUT COVERAGE WILL BE
SPARSE AT BEST AND BARELY WORTH MENTION IN THE FORECAST. WE DO
HAVE A BAND OF SHOWERS APPROACHING THE NATURE COAST FROM THE
WEST...BUT PROGRESS IS VERY SLOW AS THE FRONTAL MOVEMENT SLOWS.
ALSO...ALL THE SYNOPTIC FORCING FOR LIFT ASSOCIATED WITH THE
PARENT SYSTEM HAS EXITED WELL NORTH OF THE REGION. THIS LOSS OF
LARGE SCALE ASCENT...AND GRADUAL STRETCHING/SLOWING OF THE FRONT
AND LOSS OF LOW LEVEL FOCUS SHOULD RESULT IN LESS ORGANIZED SHOWER
ACTIVITY AS THE FRONT MOVES EAST THIS EVENING.
&&
.SHORT TERM (TONIGHT THROUGH TUESDAY)...
TONIGHT/TUESDAY...WEAK FRONTAL STRUCTURE LAYS OUT ACROSS THE
FLORIDA BIG BEND AND BECOMES QUASI-STATIONARY BY TUESDAY MORNING.
THIS IS A FAR SOUTH AS THE BOUNDARY WILL MAKE IT BEFORE RETREATING
NORTHWARD AS A WARM FRONT INTO AL/GA ON WEDNESDAY. NO RELIEF FROM
THE WARMTH AND HUMIDITY WITH THIS FRONT IS IN THE FORECAST. LOW
TEMPERATURES TONIGHT WILL AGAIN BOTTOM OUT ONLY IN THE MID/UPPER
60S FOR THE COOLER SPOTS...WITH MANY LOCATIONS NEAR THE COAST
HOLDING IN THE LOWER 70S. AS WE HEAD DEEPER INTO THE OVERNIGHT AND
THE FRONT SETTLES INTO POSITION NEAR LEVY/CITRUS/HERNANDO/SUMTER
COUNTIES...SOME UPTICK IN SHOWER ACTIVITY IS SHOWN BY MANY OF THE
GUIDANCE MEMBERS. FORECAST WILL SHOW CHANCE/LIKELY POPS FOR
SHOWERS AFTER MIDNIGHT ACROSS THE NATURE COAST ZONES...WITH
ISOLATED SHOWER CHANCES AS FAR SOUTH AS AROUND THE I-4 CORRIDOR BY
DAWN.
LAST FEW RUNS OF THE SREF MEMBERS CONTINUE TO POINT TO A HIGHER
POTENTIAL FOR WIDESPREAD LOW STRATUS/AREAS OF FOG LATER TONIGHT
INTO TUESDAY MORNING. SIMILAR TO LAST NIGHT...LEANING TOWARD
BETTER CHANCES FOR A LOW IFR STRATUS EVENT...BUT LIKELY TO SEE
SOME DENSE FOG IN A FEW SPOTS...ESPECIALLY SOUTH OF ANY SHOWER
ACTIVITY.
TUESDAY...WEAK STATIONARY FRONT REMAINS IN PLACE OVER THE NORTHERN
PENINSULA. MOISTURE PROFILES AND WEAK LOW LEVEL FOCUS ALONG THE
BOUNDARY SHOULD BE ENOUGH TO KEEP AT LEAST A CHANCE OF SHOWERS IN
THE FORECAST ALONG AND NORTH OF THE I-4 CORRIDOR. THE DRIER WEATHER
AND BETTER CHANCES FOR SUNNY BREAKS WILL CERTAINLY EXIST TO THE
SOUTH OF THE TAMPA BAY AREA TOMORROW...WHERE TEMPERATURES AGAIN
BOOST INTO THE 80S AWAY FROM THE BEACHES FOR THE AFTERNOON. OVER
THE SOUTHERN INTERIOR ZONES...ENOUGH DIURNAL INSTABILITY WILL
LIKELY EXIST TO FORCE A FEW ISOLATED SHOWERS AFTER 18Z...BUT WILL
KEEP RAIN CHANCES AT 20% OR LESS.
DUE TO MORE CLOUDS AND OCCASIONAL SHOWERS...WILL LIMIT TEMPS IN
THE MID/UPPER 70S NORTH OF I-4. WHILE MAINLY ANTICIPATING SCT
SHOWERS TOMORROW. GFS/NAM BOTH INDICATE SHOWALTER INDICES AROUND
ZERO OVER THE NATURE COAST...SO A FEW TICKS OF LIGHTNING CAN NOT
BE RULED OUT...AND HAVE ADDED ISOLATED STORMS TO THE GRIDS.
&&
.LONG TERM (TUESDAY NIGHT-MONDAY)...
FOR THE MIDDLE PART OF NEXT WEEK...AN UPPER-LEVEL LOW WILL SHIFT
EASTWARD THROUGH THE CENTRAL PART OF THE COUNTRY WITH THE UPPER
RIDGE OVER THE ATLANTIC AND FLORIDA BEING SUPPRESSED FURTHER. AT THE
SURFACE...A FRONTAL BOUNDARY WILL BE NEARLY STATIONARY ACROSS THE
NORTHERN PART OF THE PENINSULA AND WILL SHIFT NORTHWARD AS A WARM
FRONT ON WEDNESDAY. THIS SETUP WILL KEEP THE BEST RAIN CHANCES
GENERALLY NORTH OF THE TAMPA BAY AREA.
A SURFACE LOW WILL DEVELOP ALONG THE NORTHERN GULF COAST REGION
WEDNESDAY NIGHT AND SHIFT NORTHEASTWARD THROUGH THURSDAY...WITH A
STRONGER COLD FRONT APPROACHING THE BIG BEND REGION BY THE END OF
THE DAY. RAIN CHANCES WILL REALLY BEGIN TO INCREASE FOR THE NORTHERN
HALF OF THE FORECAST AREA THURSDAY AFTERNOON. THIS FRONT WILL BE
ABLE TO CLEAR THE AREA BY THE END OF THE DAY ON FRIDAY AS THE UPPER
TROUGH AXIS SWINGS TOWARD THE EAST COAST. THE FORECAST CURRENTLY
CALLS FOR LIKELY POPS FOR THE AREA THURSDAY NIGHT AND THROUGH FRIDAY
AS THE FRONT SHIFTS SOUTHWARD WITH CONDITIONS CLEARING OUT RATHER
QUICKLY FRIDAY NIGHT. HIGH PRESSURE WILL BEGIN TO BUILD OVER THE
SOUTHEAST AND REMAIN IN PLACE THROUGH THE WEEKEND. A MUCH COOLER AND
DRIER AIR MASS WILL FILTER INTO THE REGION FOR THIS PERIOD...WITH
TEMPERATURES FALLING WELL BELOW NORMAL FOR SATURDAY ESPECIALLY. THE
SURFACE HIGH WILL SHIFT EASTWARD INTO THE BEGINNING OF NEXT
WEEK...WITH A FAIRLY QUICK AIR MASS MODIFICATION GIVING US HIGHS
BACK TO AROUND NORMAL.
&&
.AVIATION...
GENERAL VFR CONDITIONS OR HIGH END MVFR OBSERVED ACROSS WEST-
CENTRAL AND SOUTHWEST FLORIDA THIS AFTERNOON AND EARLY EVENING.
POTENTIAL CONTINUE TO LOOK HIGH FOR ANOTHER WIDESPREAD LOWER
STRATUS/PATCHY FOG EVENT FOR THE SECOND HALF OF TONIGHT THROUGH
MID TUESDAY MORNING. HAVE INCLUDED LOW END MVFR MENTION AFTER 06Z
FOR ALL TAF SITES...AND MAY NEED TO DECREASE TO IFR FOR SOME SITES
WITH FUTURE TAF UPDATES. SHOULD SEE A RETURN TO GENERAL VFR OR
HIGH END MVFR CONDITIONS BY MIDDAY ON TUESDAY.
&&
.MARINE...
A WEAK COLD FRONT WILL SLOWLY APPROACH THE REGION THIS EVENING
AND STALL ACROSS THE NORTHEAST GULF OF MEXICO LATE TONIGHT AND
TUESDAY. WINDS WILL GENERALLY REMAIN OUT OF THE SOUTH AHEAD OF
THIS FRONT...BUT MAY BRIEFLY SHIFT TO THE NORTHEAST OFF THE
LEVY/CITRUS COUNTY COASTS ON TUESDAY. THIS FRONT WILL THEN LIFT
BACK NORTH ON WEDNESDAY WITH A CONTINUATION OF SOUTHERLY FLOW
ACROSS THE EASTERN GULF. WINDS AND SEAS ARE FORECAST TO GENERALLY
REMAIN BELOW HEADLINE CRITERIA THROUGH MID-WEEK.
&&
.FIRE WEATHER...
A WEAK FRONT WILL STALL ACROSS THE NORTHERN FLORIDA PENINSULA
TUESDAY AND THEN LIFT BACK NORTH INTO GEORGIA DURING WEDNESDAY.
SCATTERED SHOWERS ARE EXPECTED WITH THIS FRONT ON TUESDAY...MAINLY
ALONG AND NORTH OF THE I-4 CORRIDOR. ABUNDANT LOW LEVEL MOISTURE
WILL KEEP RELATIVE HUMIDITY WELL ABOVE CRITICAL LEVELS THE NEXT
SEVERAL DAYS...AND NO SIGNIFICANT FIRE WEATHER CONCERNS ARE
ANTICIPATED. A STRONGER COLD FRONT IS EXPECTED TO CROSS THE REGION
DURING FRIDAY WITH A MUCH COOLER AND DRIER AIRMASS ARRIVING FOR
THE UPCOMING WEEKEND.
FOG POTENTIAL...WIDESPREAD LOW CLOUDS AND AREAS OF FOG ARE
ANTICIPATED TO DEVELOP OVERNIGHT...LINGERING THROUGH THE MIDDLE OF
THE MORNING TUESDAY. PATCHY GROUND FOG IS POSSIBLE LATE TUESDAY
NIGHT INTO EARLY WEDNESDAY MORNING.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 70 77 68 81 / 10 30 20 20
FMY 69 83 69 85 / 10 10 10 10
GIF 67 80 67 83 / 10 30 10 30
SRQ 68 77 67 80 / 10 20 10 10
BKV 68 78 66 83 / 30 50 20 20
SPG 70 78 69 81 / 10 30 20 10
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH THURSDAY EVENING FOR
COASTAL SARASOTA-PINELLAS.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/AVIATION/MARINE/FIRE WX...MROCZKA
LONG TERM/DECISION SUPPORT...CARLISLE
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
121 PM EST MON DEC 14 2015
...UPDATED DUE TO AVIATION DISCUSSION...
.SHORT TERM /TODAY THROUGH TUESDAY/...
NARROW LINE OF CONVECTION WITH NO OBSERVABLE CG OR TOTAL LIGHTNING
CONTINUING TO TRAVEL EAST AT 20KTS AND SHOULD ARRIVE IN NW CORNER OF
STATE AROUND 6AM. HAVE TIGHTENED UP POP GRADIENTS AND TIMING BASED
ON 2-RUN TIME-LAGGED ENSEMBLE HRRR AND LOCAL HIRES MODEL GUIDANCE.
COULD SEE SOME SCT -SHRA AHEAD OF LINE BUT COVERAGE APPEARS TO BE 10-
20PCT BASED ON RADAR TRENDS. WITH 850-500MB MEAN RH DIPPING BELOW
10PCT BEHIND FRONT/CONVECTIVE LINE...EXPECT RAPID CLEARING OF CLOUDS
THIS AFTERNOON. GUIDANCE BLEND WITH MAX TEMPS IN THE UPPER 60S TO
UPPER 70S LOOKS GOOD. REST OF SHORT TERM PERIOD LOOKS CLEAR WITH
SW FLOW ALOFT CONTINUING AND ABOVE NORMAL TEMPS. NO WEATHER IMPACTS.
SNELSON
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
LONG TERM PERIOD STARTS OFF AS DRY BUT ALREADY SOME MODEL
DIFFERENCES EMERGE. BOTH THE GFS AND ECMWF HAVE FRONTAL BOUNDARY
ACROSS THE NORTHERN GULF AND INTO THE PANHANDLE OF FLORIDA BY 12Z
WED BUT THE GFS IS MORE AGGRESSIVE WITH ITS DEEP LAYER MOISTURE
TRANSPORT NORTHWARD. GFS SEEMS A LITTLE FAST AT THIS POINT AND
HAVE FAVORED THE ECMWF AND KEPT POPS SOUTH OF THE AREA INITIALLY.
REGARDLESS OF THE MODEL OF CHOICE...BY THE END OF THE DAY
WED...LOW PRESSURE FORMING OFF THE COAST OF LOUISIANA ALONG WITH
MODERATE ISENTROPIC ASCENT SHOULD ALLOW FOR THE DEVELOPMENT OF
WIDESPREAD LIGHT TO MODERATE RAIN. ALTHOUGH WITH THIS SETUP
SURFACE INSTABILITY WILL BE LITTLE TO NONE...40 KTS OF ISENTROPIC
FLOW ALONG WITH MARGINAL MID LEVEL LAPSE RATES SHOULD RESULT IN ELEVATED
CONVECTION FOR ALL OF CENTRAL AND MOST OF NORTH GEORGIA.
HAVE CONTINUED THE HIGH POPS IN THE GRIDS AS WELL GIVEN THE
CONSISTENCY OF THE MODEL DEPICTIONS WITH CATEGORICAL FOR MOST
AREAS. LOW LIFTS NORTH OF THE AREA BY 12Z THU WITH SOUTHERLY FLOW
DEVELOPING FOR THE SOUTHEAST CORNER. SHOULD SEE SOME SURFACE
INSTABILITY AS A RESULT AND WITH DECENT SHEAR VALUES...WILL NEED
TO MONITOR EVOLUTION OF THIS SYSTEM CLOSELY.
FRONT MOVES THROUGH BY THU NIGHT WITH A SECONDARY DRY FRONT MOVING
THROUGH ON FRIDAY. THIS SHOULD FINALLY BRING SOME COOLER TEMPS TO
THE AREA BUT MAY BE ONLY GOOD ENOUGH TO GET US BACK TO CLIMO OR
JUST BELOW FOR A DAY OR TWO BEFORE MODERATION TAKES PLACE.
DEESE
&&
.AVIATION...
18Z UPDATE...
FRONTAL SYSTEM MOVING THROUGH THE AREA WITH VFR AND MVFR CEILINGS
AND VSBYS. THE BACK EDGE OF THE PRECIP IS GOING TO MOVE THROUGH
THE ATL AREA OVER THE NEXT 2 HOURS WITH CEILINGS SCATTERING AND
THEN CLEARING OUT SHORTLY BEHIND IT. VSBYS HAVE BEEN UP AND DOWN
ALL MORNING BUT WILL FOLLOW THE LEAD OF THE CEILINGS AND STAY VFR
AS PRECIP MOVES OUT. WINDS ARE OUT OF THE SW AROUND 10KT WITH
SOME GUST TO 20KT ACROSS THE CWA. THESE WINDS WILL START TO LOOSE
THERE GUST AS THE FRONT MOVES EAST AND WILL TURN TO THE NW THROUGH
TUE MORNING.
//ATL CONFIDENCE...18Z UPDATE...
CONFIDENCE HIGH ON ALL ELEMENTS
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 70 47 69 42 / 70 5 0 0
ATLANTA 69 47 68 45 / 100 0 0 0
BLAIRSVILLE 65 42 66 39 / 100 0 0 0
CARTERSVILLE 68 44 66 40 / 100 0 0 0
COLUMBUS 70 46 71 46 / 100 0 0 0
GAINESVILLE 67 47 67 44 / 100 0 0 0
MACON 74 45 72 43 / 50 5 0 0
ROME 67 42 66 39 / 100 0 0 0
PEACHTREE CITY 69 43 69 39 / 100 0 0 0
VIDALIA 78 53 73 51 / 30 20 5 0
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...01
LONG TERM....17
AVIATION...01
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
252 PM CST MON DEC 14 2015
.SHORT TERM...(Tonight)
ISSUED AT 252 PM CST MON DEC 14 2015
Main forecast challenge in the short term will be the extent of
lingering scattered showers and the spread of drizzle this evening,
and the extent of cloud cover overnight.
The latest surface analysis at 20Z (2 pm cst) indicated an area of
low pressure in northeast IA with a trough extending southwest into
extreme northwest MO. A short wave trough axis extended from an
upper low in northeast IL into west central IL. This was producing
scattered showers in western and central IL this afternoon. These
showers are expected to shift into NE-east central IL early this
evening as the trough axis rotates through the area. Lingering low
level moisture and weak lift should produce some patchy drizzle
during the evening mainly north of a Macomb-Bloomington-Danville
line.
The short range models are in a bit of a disagreement regarding the
amount of any breaks/clearing in the cloud cover overnight. The NAM,
SREF and HRRR indicate that the clouds shouldn`t start breaking up
until later Tuesday morning, while the GFS and RAP are trying to
clear things up around or just before daybreak. Prefer the slower
solutions of keeping the cloud cover over the forecast area into the
morning. Even if the quicker clearing models verify, the saturated
ground and lighter surface winds should allow for stratus and fog to
develop quickly. With the clouds and gradually decreasing westerly
winds, temperatures overnight will only drop slowly into the 36-40
degree range.
&&
.LONG TERM...(Tuesday through Monday)
ISSUED AT 252 PM CST MON DEC 14 2015
After a dry period tomorrow, another weather system is forecast to
move out of the southern Rockies and northeast across the plains and
into the western Great Lakes region. A cold front associated with
this system will slide across the CWA on Wednesday. Ahead of the
front, tomorrow into tomorrow night, limited low level moisture will
be advected northward into the area. Based on this and limited
dynamics, showers will be possible late tomorrow night through
Wednesday, across the CWA. By Wed evening, the front will have
pushed east of the area and the pcpn will have ended, leaving Wed
night and Thur dry.
Temps will remain mild/above normal through Wed, but then fall to
around normal for Thursday, behind this brief system. Model guidance
looks good through the period.
The remainder of the week and into the weekend will be dry as a
large mid level trough tracks across the US. This trough and
associated sfc high pressure area will bring dry weather and colder
temps. Northwest flow will be temporary for Sat and then transition
back to southwest flow for Sunday and Monday. The southwest flow
will allow southerly winds to return on the sfc, bringing above
normal temps back to the area for Sun and Mon. Along with the warmer
temps, pcpn will return for Sunday night and Mon as another weather
system moves toward and through the area.
Temps will be around or just below normal for Fri and Sat, but then
with southerly winds returning, temps will return to above normal
levels for Sun and Mon.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1200 PM CST MON DEC 14 2015
A few breaks in the MVFR conditions are being noted just before
18z in parts of central and western IL behind a shortwave that is
rotating around an upper low in NE Iowa. This will be short lived
as generally MVFR ceilings upstream move into the region. In
addition, VFR ceilings and light rain in eastern IL along the
shortwave trough axis will eventually be dropping into the MVFR
category during the afternoon.
The upper low is expected to lift to western MI by early this
evening, and then rapidly across southern Ontario. At the lower
levels and the surface, central and eastern IL will remain in the
cyclonic flow up until daybreak. This should keep enough low level
moisture in place for MVFR ceilings through the night. As we
approach the pre-dawn hours, surface winds will decrease which
should allow visibilities to drop to 3-5 miles with IFR ceilings.
The NAM and RAP models are both showing this scenario, with the
GFS model seeming to clear us out too quickly. However, even if
the GFS verifies, the light wind and saturated ground would cause
stratus and fog to develop rather quickly. Am expecting the
ceilings to improve to at least MVFR by late morning.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Miller
LONG TERM...Auten
AVIATION...Miller
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1200 PM CST MON DEC 14 2015
.UPDATE...
ISSUED AT 1104 AM CST MON DEC 14 2015
Made minor adjustments to the forecast based on current radar and
satellite trends. The back end of the last band of showers
associated with a shortwave, rotating around the upper low near
Dubuque, is moving through east central IL late this morning. This
will be accompanied by light to moderate rain and wind gusts of
30-40 mph into the Noon hour before it moves out of the region.
Scattered showers will move back into/develop in the forecast
area this afternoon as the upper low lifts toward western MI. The
presence of clouds and periods of light showers will keep
temperatures nearly steady early this afternoon with a slow
downward trend toward late afternoon as winds veer from the west.
Gusty winds will continue through the afternoon as the surface
gradient stays strong and low level winds mix down with the
showers.
A few showers may linger in extreme eastern IL early this
evening, otherwise the rest of the forecast area will dry out with
mostly cloudy conditions hanging around for much of the night.
&&
.SHORT TERM...(Today)
ISSUED AT 325 AM CST MON DEC 14 2015
Strong low pressure, currently centered over eastern Iowa, will
continue to impact central and southeast Illinois today. The cold
front associated with the system currently extends southeast across
northern Illinois, and has already cleared entire forecast area.
Post frontal cold air advection is actually spreading across the
region from the southwest, a somewhat unusual occurrence. The strong
cold advection will prevent much of a temperature rise today, with
temperatures expected to be steady or slowly falling for the most
part. That being said, daytime highs will still be well above
normal, in the lower 50s, for the middle of December. The winds
bringing in this colder air are expected to remain quite gusty
today, with gusts to 35 mph likely for much of the day.
The more widespread/heavier rainfall associated with this storm
system will be north/east of the forecast area to start the day.
However, the upper low/cold pool driving the surface system is still
centered near the KS/MO border area. The upper circulation is
expected to lift into the Great Lakes by this evening, and scattered
showers are expected until the circulation clears the Midwest.
.LONG TERM...(Tonight through Sunday)
ISSUED AT 325 AM CST MON DEC 14 2015
Ending the precip this evening is the first issue for the forecast.
Previous runs have been pretty persistent in drying out much of
Central Illinois by late this afternoon. The 06Z NAM is the hold
out, lingering some precip in the north and east as the system pulls
away. Have kept the forecast dry after 00z for now, but will see if
the NAM remains the outlier. Next issue for the forecast through
the overnight is to watch the potential for fog development yet
again. At this point, forecast has too many clouds for efficient
radiational cooling, and the winds stay up a bit more as well.
Weaker wind field just to the SW however. Crossover temps this
afternoon will be key, but just not enough to go with a fog mention
in the forecast just yet. Tonight and tomorrow mainly dry. Models
bringing the second low through the region quickly for tomorrow
night and Wednesday. Models are more consistent with the precip
along the boundary now, so chance pops progress across the CWA
through that time frame. Some cooler air moves into the region
behind Wednesdays front, and Friday and Saturday are the coolest
days in the forecast with highs only reaching into the 30s. Saturday
night however, the winds pick back up out of the SW and another warm
up starts to wrap up the weekend.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday afternoon)
ISSUED AT 1200 PM CST MON DEC 14 2015
A few breaks in the MVFR conditions are being noted just before
18z in parts of central and western IL behind a shortwave that is
rotating around an upper low in NE Iowa. This will be short lived
as generally MVFR ceilings upstream move into the region. In
addition, VFR ceilings and light rain in eastern IL along the
shortwave trough axis will eventually be dropping into the MVFR
category during the afternoon.
The upper low is expected to lift to western MI by early this
evening, and then rapidly across southern Ontario. At the lower
levels and the surface, central and eastern IL will remain in the
cyclonic flow up until daybreak. This should keep enough low level
moisture in place for MVFR ceilings through the night. As we
approach the pre-dawn hours, surface winds will decrease which
should allow visibilities to drop to 3-5 miles with IFR ceilings.
The NAM and RAP models are both showing this scenario, with the
GFS model seeming to clear us out too quickly. However, even if
the GFS verifies, the light wind and saturated ground would cause
stratus and fog to develop rather quickly. Am expecting the
ceilings to improve to at least MVFR by late morning.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Miller
SHORT TERM...BAK
LONG TERM...HJS
AVIATION...Miller
AREA FORECAST DISCUSSION
National Weather Service Topeka KS
334 PM CST MON DEC 14 2015
.SHORT TERM...(This Evening through Tuesday)
Issued at 329 PM CST MON DEC 14 2015
Upper ridge building in between the old upper system nearing the
Great Lakes and the next deep system developing over the Central
Rockies. Surface pressure rises rather strong just to the northeast,
though considerable falls occurring in eastern Colorado. Northwest
winds decreasing in eastern Kansas, with east winds already
developing in western portions of the state. Stratus, rather thin in
spots, was making only slow progress east on latest satellite loop
with local dewpoint depressions in the 3-10F range.
Main concerns into Tuesday are at the very low levels, unfortunately
where model skill is at its lowest. The next system crosses the
Rockies tonight with surface low entering Kansas. Winds will be
quite light between these systems much of the evening though pick up
toward dawn. With a very wet ground and wet boundary layer, a
favorable setup for radiational fog is in place...if clearing can
occur. So far, guidance has shown very poor skill in handling the
very slow clearing and where it is and is not occurring. Even 19 and
20Z RAP and 15Z SREF data is quite poor in its initial few hours of
progs. Skies could easily remain rather cloudy for especially
northern areas through the night, but think at least enough patches
of clearing are possible for some fog formation. Have kept any
mention limited to the late evening through 12Z as winds/mixing
increase late in the night. Guidance that is more pessimistic with
the stratus suggests some light drizzle could also occur, but the
thin nature of the cloud and little if any lift in it should keep it
from being notable, and temps/ground temps largely warm enough to
keep slick road issues at bay if it were to form. Have kept Tuesday
rather warm given temps in south central Kansas in the low-mid 50s
today. Moisture in the mid and upper levels is rather hard to come
by with the system this far southeast, but will keep a small PoP in
the far northwest nearer the better moisture.
.LONG TERM...(Tuesday Night through Monday)
Issued at 329 PM CST MON DEC 14 2015
Dry cold front moves through the forecast area Tuesday night, as
the next upper low moves across Nebraska and to the north
northeast dragging the front behind. Additional waves moving
through this upper trof keep the Central Plains in the colder air
through Friday. Highs drop to the upper 30s to near 40, with lows
falling into the 20s. Still on track to warm up a bit for the
weekend as upper ridge moves across the state and highs rise back
into the 40s and 50s. Next chance for rain starts Monday but wave
is low amplitude and part of a larger upper system that approaches
the Central Plains later in the week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Tuesday Afternoon)
Issued at 1143 AM CST MON DEC 14 2015
Currently, MVFR ceilings are in place across much of northeast
Kansas. These ceilings are expected to scatter out to VFR later
this afternoon as the low continues to move north. Confidence is
lower toward the end of the period as there is a chance for reduced
visibilities and ceilings again tomorrow morning. Winds appear to
stay high enough to prevent any fog formation at this time and have
left any MVFR conditions out of this TAF issuance.
&&
.TOP Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Sanders
LONG TERM...67
AVIATION...Heller
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1147 AM CST MON DEC 14 2015
.UPDATE...
Issued at 1142 AM CST MON DEC 14 2015
For aviation section only.&&
.SHORT TERM...(Today through Wednesday night)
Issued at 410 AM CST MON DEC 14 2015
The primary rain shield should be out of ern parts of the PAH
forecast area by around sunrise, with scattered light showers
possible almost everywhere through mid afternoon, then back to dry
conditions.
A vigorous low pressure system just to the west of the PAH
forecast area will continue to move rapidly northeastward toward
the Great Lakes today. As this occurs through the late morning and
early afternoon, there will still be a decent pressure gradient
across our region. A blend of RAP and NAM data suggested that
mixing down of just below wind advisory winds will occur today.
Gusts into the middle 30s kts appear possible. Without a sfc
focusing mechanism for enhanced lift, there is no plan to hoist a
wind advisory today, though there will be some substantial wind
for a few hours at any one spot. The swrly winds should steadily
decrease after sunset, and skies will gradually clear from the sw.
Our region will be under a brief period of ridging between
systems, then another vigorous low pressure system, further away
this time, is progged to move across the nrn Plains and into the
Great Lakes region by Wednesday. Moisture return is expected to be
limited, and therefore PoPs/QPF are limited with this system.
.LONG TERM...(Thursday through Sunday)
Issued at 410 AM CST MON DEC 14 2015
Above average confidence in the long term period as latest model
runs in good agreement and very little to discuss.
For the most part, high pressure at the surface and broad cyclonic
flow aloft will dominate the region`s weather Thursday and Friday.
Models bring a short wave across the area Thursday night but with no
surface reflection and very limited moisture, only an increase in
cloud cover is expected.
Beyond that, high pressure will remain over the area at the
surface but heights aloft will be on the increase which will
continue to keep the region dry, with temperatures warming back
to above normal through the end of the period.
The next chance of precipitation appears to be next Monday as a
system moves out of the plains, but for now that is just beyond the
scope of this forecast package and is for planning purposes only.
&&
.AVIATION...
Issued at 1142 AM CST MON DEC 14 2015
MVFR cigs 2k-3kft will gradually raise to VFR during the
afternoon..then skies should clear this evening. Gusty ssw winds
20-30 KTS will gradually diminish late in the day.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
UPDATE...GM
SHORT TERM...DB
LONG TERM...JP
AVIATION...GM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
550 PM EST MON DEC 14 2015
.UPDATE...
ISSUED AT 547 PM EST MON DEC 14 2015
EXPANDED WINTER WEATHER ADVISORY ACROSS REST OF WESTERN UPR MICHIGAN
THIS EVENING AS REPORTS ARE INDICATING MAINLY SLEET IS OCCURRING IN
DEFORMATION BAND OF WINTRY PRECIP ON WEST SIDE OF SFC LOW VCNTY OF
KISQ AS OF 5 PM. 21Z RAP PEGGING LOCATION OF DEFORMATION BAND WELL
THOUGH SOUNDINGS ARE A BIT TOO COLD ALOFT COMPARED TO REALITY. RAP
SHOWS DEFORMATION BAND WITH QPF AMOUNTS TO 0.15 INCHES THROUGH 00Z
THEN BEGINS TO TAPER. GIVEN MOST OF THE PRECIP IS FALLING AS SLEET
WHICH IS REALLY LEADING TO ROUGH ROAD CONDITIONS PER REPORTS FM
SPOTTERS IN ONTONAGON COUNTY AND SHERIFF IN BARAGA COUNTY...EXPANDED
THE ADVY. A COLD RAIN FARTHER EAST...WITH NWS OFFICE SITTING AT 32-33
AS OF 530 PM. FOR NOW SPS IS OUT FOR IRON/DICKINSON/MARQUETTE AND
THAT PROBABLY WILL HOLD UNLESS HEAVIER DEFORMATION PRECIP SLIDES
FARTHER EAST. WILL KEEP MONITORING THIS. HIGHEST SNOW/SLEET TOTAL WAS
AROUND 2 INCHES FAR WEST...BUT ALREADY SEEING 1-2 INCHES HIGHER
TERRAIN BETWEEN ONTONAGON AND HOUGHTON AND MOST RECENTLY NEAR HERMAN
IN HIGHER TERRAIN OF BARAGA COUNTY. ALL AREAS CURRENTLY SEEING THE
SNOW/SLEET MAY SEE ADDITIONAL 1-2 INCHES BEFORE THE EVENING IS OUT SO
ROADS WILL CONTINUE TO BE IN ROUGH SHAPE.
CURRENT WINTER WEATHER ADVISORIES GO UNTIL 06Z. MAYBE A BIT
LONG...BUT CAN EVALUATE THAT LATER THIS EVENING. COULD SEE THIS
WHOLE WINTRY MIX CHANGE TO DRIZZLE/FREEZING DRIZZLE LATER TONIGHT.
OVERALL A MESSY NIGHT...ESPECIALLY FOR THE HIGHLANDS OF WESTERN UPR
MICHIGAN.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 402 PM EST MON DEC 14 2015
TRICKY FORECAST WITH PRECIPITATION TYPE LATE THIS AFTERNOON INTO
THIS EVENING. WINTER WEATHER ADVISORY IN EFFECT THROUGH 06Z/15FOR
GOGEBIC AND ONTONAGON COUNTIES.
RADAR IMAGERY CONTINUES TO SHOW A WIDE SWATH OF PRECIPITATION ACROSS
THE U.P. STRETCHING BACK INTO THROUGH PORTIONS OF NORTHERN AND
WESTERN WI. SATELLITE IMAGERY SHOWS EXTENSIVE CLOUD COVER ACROSS THE
UPPER GREAT LAKES. WV IMAGERY SHOWS THE UPPER LEVEL LOW CENTERED
OVER SOUTHERN WI THIS AFTERNOON WITH PLENTY OF MOISTURE TO THE NORTH
AND WEST OF THE LOW. THE DRY SLOT ASSOCIATED WITH THE LOW IS WORKING
IN ACROSS SOUTHERN LOWER MI AND THE OHIO VALLEY. SURFACE
OBSERVATIONS...OBSERVERS AND WEBCAMS HAVE BEEN SHOWING A MIX OF
FREEZING RAIN...SLEET AND SNOW ACROSS FAR WESTERN PORTIONS OF THE
U.P. SPECIFICALLY AROUND GOGEBIC AND ONTONAGON COUNTIES.
LATE THIS AFTERNOON THROUGH TONIGHT...THE FAIRLY STRONG SURFACE LOW
SLIDING THROUGH THE U.P. THIS AFTERNOON WILL CONTINUE TO PRODUCE
WIDESPREAD RAINFALL ACROSS THE NORTH HALF OF THE U.P. THESE AREAS
COULD SEE AN ADDITIONAL 0.5 INCH TO 0.75 INCH OF QPF DURING THE MID
TO LATE AFTERNOON HOURS. THE DEEP LAYER FORCING ASSOCIATED WITH THE
LOW WILL LINGER BETWEEN 18Z/14 AND 00Z/15 BEFORE EXITING TO THE
NORTH AND EAST OF THE AREA DURING THE EVENING AND OVERNIGHT HOURS.
THIS CAN BE SEEN BY ANALYZING THE DEEP LAYER QCONV ALONG WITH 1000-
500MB RH. THE BIG ISSUE...HOWEVER...IS PRECIPITATION TYPE. MODELS
HAVE A WARM NOSE ALOFT BETWEEN 800MB AND 850MB...AND A COLDER LAYER
BELOW WHICH HAS LED TO A MIXED BAG OF PRECIPITATION OVER THE FAR
WESTERN U.P. THIS HAS RESULTED IN MAINLY SLEET...HOWEVER...SOME
FREEZING RAIN HAS BEEN REPORTED ACROSS THE FAR WEST AREA AS SURFACE
TEMPERATURES HOVER AROUND 32F.
TIMING OF TRANSITION ACROSS THE U.P. WILL BE A BIT TRICKY...BUT
LATEST MODEL DATA SUGGESTS THAT RAIN WILL MIX WITH SLEET OVER
CENTRAL PORTIONS OF THE U.P. BY 21Z-22Z AND THEN OVER TO SNOW LATER
IN THE EVENING. OVER THE EAST HALF OF THE UPPER
PENINSULA...TEMPERATURES SHOULD REMAIN WARM ENOUGH TO KEEP THE
PRECIPITATION IN THE FORM OF RAIN UNTIL LATE EVENING...WHEN THE
DEEPER MOISTURE PULLS AWAY FROM THE REGION. THE HEAVIEST SLEET/SNOW
TOTALS WILL LIKELY REMAIN CONFINED TO THE GOGEBIC AND ONTONAGON
AREAS AND UP THROUGH THE KEEWEENAW PENINSULA...WHERE THE DEFORMATION
BAND HAS SET UP UNDER THE COMMA HEAD OF THE LOW PRESSURE SYSTEM THIS
AFTERNOON. THIS DEFORMATION BAND IS ON A PIVOT POINT AS THE SURFACE
LOW TAKES ON A MORE EAST TO EAST-NORTHEASTERLY TRACK...HELPING TO
CONCENTRATE THE SNOW/SLEET TOTALS IN THAT AREA. THE FORCING IN THAT
AREA IS ACTUALLY PROVIDING ENOUGH LIFT THIS AFTERNOON TO MIX SOME
SNOWFALL IN WITH THE SLEET. AS FAR AS TOTALS...BY THE TIME THE
DEEPER MOISTURE LEAVE THIS EVENING...WILL BE AROUND 2 TO 4 INCHES IN
ONTONAGON AND GOGEBIC COUNTIES. FARTHER NORTH IN THE KEWEENAW LOOKS
LIKE AROUND 1 TO 2 INCHES...WHILE CENTRAL AREAS WILL LIKELY SEE AN
INCH OR LESS AS THE DEFORMATION SLIDES THROUGH AT A FASTER PACE IN
THOSE AREAS. ONCE THE DEEPER MOISTURE DEPARTS TONIGHT...EXPECT MOST
OF THE PRECIPITATION TO TRANSITION TO DRIZZLE OR FREEZING
DRIZZLE...BUT SNOW WILL ALSO MIX IN OVER THE HIGHER TERRAIN OF THE
WEST...ESPECIALLY ALONG LAKE SUPERIOR WHERE UPSLOPE COULD PROVIDE
ENOUGH LIFT TO INTRODUCE ICE CRYSTALS INTO THE LAYER.
TUESDAY...A MUCH QUIETER WEATHER DAY CAN BE EXPECTED ACROSS THE U.P.
AS THE SURFACE LOW AND UPPER LEVEL LOW PRESSURE SLIDE INTO SOUTHERN
QUEBEC. HIGH PRESSURE AND UPPER LEVEL RIDGING WILL SLIDE IN BEHIND
THE LOW. THIS WILL ALLOW FOR DRIER CONDITIONS ACROSS UPPER
MICHIGAN...HOWEVER...CLOUD COVER WILL LINGER THROUGH THE DAY WITH
CONTINUED LOW LEVEL MOISTURE TRAPPED BELOW THE INVERSION IN PLACE
FROM THE UPPER LEVEL RIDGING SLIDING INTO THE AREA. TEMPERATURESWILL
BE MUCH COOLER...ESPECIALLY OVER THE EAST HALF WITH HIGHS ONLY
REACHING INTO THE LOW TO MID 30S.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 503 PM EST MON DEC 14 2015
MODELS SUGGEST THAT A PROGRESSIVE PATTERN WILL CONTINUE TO PREVAIL
WITH A TRANSITION TOWARD COLDER CONDITIONS TOWARD THE END OF THE
WEEK IN THE WAKE OF A MID LEVEL AND SFC LOW LIFTING FROM THE UPPER
MS VALLEY INTO NRN ONTARIO. AS A TROUGH MOVES INTO THE WEST
COAST...A RIDGE WILL BUILD INTO THE CNTRL CONUS BY SUN WITH
MODERATING TEMPS OVER THE WRN LAKES. ANOTHER BATCH OF PCPN MAY BE
POSSIBLE BY MON AS WAA INCREASES AHEAD OF A LOW MOVING IN FROM THE
PLAINS.
TUE NIGHT...ABUNDANT LOW LEVEL MOISTURE BELOW A 900 MB INVERSION
ALONG WITH ERLY FLOW MAY SUPPORT DZ/FZDZ OVER N CNTRL UPPER
MI...ESPECIALLY WHERE UPSLOPE FLOW PREVAILS. OTHERWISE...THE THICK
CLOUD COVER WILL KEEP TEMPS FROM FALLING BELOW THE UPPER 20S.
WED...THE MODELS WERE IN GOOD AGREEMENT WITH THE LOW TRACK FROM SRN
MN AT 12Z TO THE MN ARROWHEAD BY 00Z/THU. FAVORABLE DYNAMICS WITH
MODERATE TO STRONG 700-300 MB QVECTOR CONV AND AN AREA OF 290K-295K
ISENTROPIC LIFT SUPPORT MENTION OF LIKELY POPS OVER THE CNTRL AND
WEST IN THE MORNING INTO THE EAST DURING THE AFTERNOON. PCPN TYPE
WILL AGAIN BE A CONCERN GIVEN DIFFERENCES AND THE TEMP PROFILE
DETAILS. THE NAM SUGGESTS THE STRONGER LIFT WILL BRING ENOUGH LAYER
COOLING TO CHANCE THE PCPN TO MAINLY SNOW DURING THE PERIOD OF
HIGHER QPF...WHILE THE GFS BRINGS GREATER WARMING BY 18Z. FOR
NOW...THE FORECAST EMPHASIZES MAINLY SNOW OVER THE CENTRAL AND WEST
WITH A MIX AND CHANGE TO RAIN ONCE THE STRONGER DYNAMICS MOVE OFF TO
THE EAST. WITH A GREATER WARM AIR INFLUX INTO THE EAST...RAIN SHOULD
PREDOMINATE. ANY SNOWFALL AMOUNTS WOULD BE MINIMAL...MAINLY LESS
THAN AN INCH.
WED NIGHT...WRLY SFC-850 MB CAA ALONG WITH SOME WRAP-AROUND MOISTURE
WILL BRING A CHANGEOVER TO SHSN FROM WEST TO EAST. ANY LES OR LAKE
ENHANCED SNOW WILL BE LIGHT WITH 850 MB TO AROUND -9C LATE WITH A SW
TO WSW LOW LEVEL FLOW PREVAILING.
THU-SAT...COLDER AIR ARRIVES ALONG WITH A SECONDARY MID LEVEL TROUGH
AND LOW. WITH 850 MB TEMPS FALLING TO AROUND -15C AND DEEP MOISTURE
ACROSS THE AREA...LES WILL INCREASE FOR LOCATIONS FAVORED BY W TO
WNW FLOW. ACCUMULATING SNOW OVER THE KEWEENAW WILL BE LIKELY AND BY
FRIDAY NEAR LAKE SUPERIOR EAST OF MUNISING AS THE WINDS VEER
SLIGHTLY. THE LES SHOULD DIMINISH SAT INTO SAT NIGHT AS THE 850 MB
THERMAL TROUGH SLIDES OFF TO THE EAST.
SUN-MON...THERE IS MUCH GREATER UNCERTAINTY WITH THE DETAILS ON THE
STRENGTH/TIMING OF ANY SHORTWAVES LIFTING TOWARD THE UPPER MS VALLEY
AND WRN LAKES. THE OVERALL PATTERN WILL FAVOR A MODERATING TREND
WITH POTENTIAL FOR PCPN AGAIN BY MON. THE PROXIMITY OF THE WARM AIR
AND POTENTIAL FOR A LOW TRACK TO THE WEST OF UPPER MI WILL AGAIN
BRING THE POTENTIAL FOR MIXED PCPN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1232 PM EST MON DEC 14 2015
A STRONG LOW PRESSURE SYSTEM MOVING SOUTH OF THE AREA TODAY WILL
CONTINUE TO BRING LOW CIGS/VIS...WITH SOME IMPROVEMENT STARTING
TUESDAY MORNING. MOST UNCERTAINTY IN THE FIRST 12 HOURS IS WITH
PRECIP TYPE AT KIWD AND KCMX WHERE MODELS ARE NOT HANDLING THERMAL
PROFILES WELL AND A MUCH EARLIER THAN EXPECTED TRANSITION TO
SNOW/MIXED PRECIP HAS OCCURRED. LATER TONIGHT AND TOMORROW THE MOST
UNCERTAINTY IS WITH CIG/VIS MAGNITUDE AND HOW FAST ANY IMPROVEMENT
MAY OCCUR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 402 PM EST MON DEC 14 2015
AS LOW PRESSURE SLIDES ACROSS THE EASTERN UP THIS AFTERNOON INTO
TONIGHT...NORTHEAST GALES WILL TRANSITION TO NORTH GALES ACROSS LAKE
SUPERIOR AS COLDER AIR FILTERS ACROSS THE LAKE. THERE IS A POTENTIAL
FOR A FEW STORM FORCE GUSTS LATE THIS AFTERNOON INTO THE EARLY
EVENING HOURS...ESPECIALLY BETWEEN ISLE ROYALE AND THE KEWEENAW.
WINDS WILL SUBSIDE TEMPORARILY ON TUESDAY MORNING BEFORE ANOTHER LOW
PRESSURE SYSTEM DEVELOPS AND SLIDES THROUGH THE UPPER GREAT LAKES
WEDNESDAY INTO THURSDAY. NORTHEAST WINDS WILL INCREASE TO GALES OVER
THE WEST HALF LATE TUE INTO WED MORNING AND SOUTHEAST WINDS SHOULD
REACH GALE FORCE OVER THE CENTRAL AND EASTERN LAKE AHEAD OF THE LOW
ON WEDNESDAY FOLLOWED BY WESTERLY WINDS APPROACHING GALES IN THECOLD
ADVECTION BEHIND THE LOW ON THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ TUESDAY
FOR MIZ001>004-009-084.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST TUESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST TUESDAY FOR LSZ265-266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ TUESDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KEC
LONG TERM...JLB
AVIATION...TITUS
MARINE...KEC
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1234 PM EST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 520 AM EST MON DEC 14 2015
WV IMAGERY SHOWS MID-UPPER LOW SPINNING ALONG KS/MO BORDER AS IT
LIFTS SLOWLY NE EARLY THIS MORNING. IMPRESSIVE MOISTURE PLUME NOTED
AHEAD OF LOW WITH CLASSIC BAROCLINIC LEAF STRUCTURE AS MOISTURE
WRAPS BACK INTO COMMA HEAD NORTH OF LOW. INCREASING UPPER DIFFLUENCE
AND DEEP LAYER Q-VECT CONVERGENCE AHEAD OF THE APPROACHING LOW ALONG
WITH INCREASING 850-700 MB FGEN ENHANCED BY COUPLED UPPER JET
STRUCTURE HAS ALLOWED HEAVIER RAIN BAND TO SPREAD INTO SOUTH CENTRAL
AND EASTERN UPPER MI EARLY THIS MORNING. MEANWHILE A NE FLOW OF
DRIER FEEDING FROM NORTH OF LAKE SUPERIOR HAS KEPT THE NW HALF OF
UPPER MI GENERALLY DRY OVERNIGHT WITH LITTLE MORE THAN DRIZZLE
REPORTED.
TODAY...AS NEG-TILT MID-UPPER LEVEL TROUGH AND EMBEDDED CLOSED LOW
CONTINUE TO LIFT NE INTO THE UPPER GREAT LAKES REGION DEEP LAYER Q-
VECT CONVERGENCE AND MID-LVL FGEN FORCING WILL CONTINUE TO SPREAD
NORTHWARD ACROSS FORECAST AREA ALLOWING BAND OF HEAVY RAIN ASSOC
WITH DEFORMATION AREA/COMMA HEAD OF SYSTEM TO SPREAD NORTHWARD AND
WESTWARD THROUGH THE DAY. WITH COMBINATION OF STRONG FORCING AND
INCREDIBLE PRECIPITABLE WATER VALUES OF 1-1.3 INCHES MUCH OF THE
FORECAST COULD SEE RAIN AMOUNTS FROM 1-1.7 INCHES TODAY HEAVIEST
SOUTH CENTRAL AND EAST. TRICKY PORTION OF FORECAST THIS AFTERNOON
WILL BE TIMING OF CHANGEOVER FROM RAIN TO SNOW IN FAR WEST. MODELS
VARY GREATLY IN THIS REGARD...WITH THE GFS AND PARTICULARLY THE NAM
MORE AGGRESSIVE WITH CHANGEOVER TO SNOW THAN THE RAP PERHAPS
INDICATING POTENTIAL FOR DYNAMIC COOLING FROM STRONG FORCING WITHIN
COMMA HEAD OF SYSTEM. GIVEN MODEL UNCERTAINTY...I ONLY HAVE AN INCH
OR TWO OF SLUSHY ACCUMULATION LATE THIS AFTERNOON INTO THIS EVENING
FOR FAR WEST...BUT CERTAINLY NOT OUT OF QUESTION THAN THERE COULD BE
MORE SNOW FOR GOGEBIC-ONTONAGON COUNTIES IF CHANGEOVER OCCURS WHILE
DEFORMATION PRECIP BAND IS OVER AREA. THIS WILL BE SOMETHING FOR
DAYSHIFT TO CLOSELY MONITOR THIS AFTERNOON AS A QUICKER CHANGEOVER
TO SNOW COULD WARRANT A HEADLINE FOR POTENTIAL ADVISORY SNOWFALL
AMOUNTS.
TONIGHT...AS THE LOW DEPARTS EAST OF THE AREA THIS EVENING...COLDER
AIR PUSHING IN BEHIND THE SYSTEM WILL ALLOW FOR CONTINUED TRANSITION
OF PRECIPITATION FROM RAIN TO SNOW SPREADING WEST TO EAST. AS
WRAPAROUND MOISTURE DEAPRTS EAST WITH COMMA HEAD OF SYSTEM...FCST
SOUNDINGS SUGGEST MID LEVEL DRYING WITHIN DGZ WHICH COULD ALSO
RESULT IN FORMATION OF DRIZZLE OR FREEZING DRIZZLE SO HAVE INCLUDED
THIS IN FORECAST AS WELL.
HIGH TEMPERATURES TODAY WILL RANGE FROM MID TO UPPER 30S WEST TO
AROUND 50F EAST AND SOUTHEAST. LOWS TONIGHT WILL DROP INTO THE UPPER
20S WEST TO LOWER TO MID 30S SOUTH CENTRAL AND EAST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 413 AM EST MON DEC 14 2015
AS THE LOW DEPARTS TO THE EAST ON TUESDAY...THE MODELS INDICATE
PLENTY OF LOW LEVEL MOISTURE TRAPPED UNDER THE STRONG INVERSION
ACROSS THE AREA. MODEL SOUNDINGS SUGGEST THAT THE CLOUD LAYER WILL
BE ABOUT 2000 FT WITH ALL TEMPERATURES GENERALLY ABOVE -10C. THIS
WOULD IMPLY LIMITED ICE NUCELI AVALABILITY LEADING TO PERHAPS A
DRIZZLE/FREEZING DRIZZLE EVENT IN THE FAVORED UPSLOPE AREAS DURING
THE DAY ON TUESDAY. HOWEVER...AS SEEN ON FRIDAY NIGHT...THE CLOUD
LAYER MAY JUST BE COLD ENOUGH TO ALLOW FOR SNOW AS WELL. AS
SUCH...WILL GO WITH A SLIGHT CHANCE OF SNOW WITH PATCHY FZDZ/DZ IN
THE FAVORED UPSLOPE AREAS OF N-CENTRAL AND WEST UPPER MICHIGAN.
OTHERWISE...TUESDAY SHOULD BE A FAIRLY QUIET DAY ACROSS THE AREA
WITH WEAK FLOW BEFORE THE NEXT SYSTEM APPROACHES WED.
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST THAT THE LOW TRACK FOR
WED WILL STAY WEST AS THE UPPER TROUGH BECOMES NEGATIVELY TILTED. AS
SUCH...WILL LIKELY SEE A PERIOD OF PRECIPITATION MOVING FROM SOUTH
TO NORTH LATE TUE NIGHT INTO WED AS THE OCCLUDED FRONT MOVES ACROSS
THE AREA. THEN THE DRY SLOT WILL MOVE IN WED AFTN LIKELY CUTTING OFF
PRECIPITATION OR REDUCING IT TO DRIZZLE/FZDZ. PRECIPITATION TYPE
WILL BE A LITTLE TRICKIER WITH THIS SYSTEM AS THERE WILL BE A LITTLE
MORE COLD AIR AVAILABLE. AM EXPECTING ANY PRECIPITAITON LATE TUE
NIGHT WILL BE FROZEN...BUT QUICKLY TURN TO LIQUID WED MORNING. COULD
POTENTIALLY SEE A LITTLE FREEZING RAIN ACROSS THE SOUTH CENTRAL BUT
IT SHOULD BE BRIEF AS ANY SURFACE TEMPERATURES BELOW FREEZING SHOULD
RISE TO ABOVE FREEZING DUE TO LATENT HEATING EFFECTS. WILL MAINTAIN
LIKELY POPS ACROSS THE AREA ON WEDNESDAY TAPERING TO CHANCE IN THE
AFTN AND EVENING.
THE BIG STORY WITH THIS SYSTEM WILL BE THE COLDER AIRMASS ASSOCIATED
WITH IT FOR THE END OF THE WEEK INTO SATURDAY. BY 12Z THURSDAY THE
LOW WILL BE NORTH OF LAKE SUPERIOR WITH 850MB TEMPS DROPPING TO -11C
ACROSS THE WESTERN PART OF LAKE SUPERIOR. STRONGLY CYCLONIC FLOW AND
DEEP MOISTURE SHOULD ALLOW FOR LAKE EFFECT SNOW TO DEVELOP LATE WED
NIGHT AND CONTINUE THROUGH FRIDAY AT LEAST. W-NW FLOW INITIALLY ON
THURSDAY SHOULD ALLOW FOR THE WEST TO SEE ACCUMULATING LES. THEN ON
THU NIGHT INTO FRI A SECONDARY TROUGH MOVES THROUGH ALLOWING THE LES
TO BECOME BETTER ORGANIZED EAST OF MARQUETTE INTO ALGER/LUCE/NRN
SCHOOLCRAFT COUNTIES. WIND DIRECTION STILL NOT FAVORABLE FOR LES IN
MARQUETTE COUNTY THOUGH. WARM ADVECTION COMMENCES SAT AFTN INTO
SUNDAY AS THE RIDGE BUILDS TO THE WEST OF THE AREA...HELPING TO END
ANY LES BY SATURDAY EVENING. STILL FAIRLY FAR OUT TO BE TALKING
ACCUMULATIONS AT THE END OF THE WEEK...BUT THE LES PARAMETER IS VERY
HIGH /AROUND 2/ OWING TO THE DEEP MOISTURE AND COLD 850MB TEMPS. WITH
THE LONGEVITY OF THE LES...IT CERTAINLY DOES NOT SEEM OUT OF THE
QUESTION THAT SOME PLACES FROM ONTONAGON TO THE KEWEENAW PENINSULA
AND IN ALGER/LUCE COUNTIES COULD SEE PLOWABLE SNOWFALL AT THE END OF
THE WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1232 PM EST MON DEC 14 2015
A STRONG LOW PRESSURE SYSTEM MOVING SOUTH OF THE AREA TODAY WILL
CONTINUE TO BRING LOW CIGS/VIS...WITH SOME IMPROVEMENT STARTING
TUESDAY MORNING. MOST UNCERTAINTY IN THE FIRST 12 HOURS IS WITH
PRECIP TYPE AT KIWD AND KCMX WHERE MODELS ARE NOT HANDLING THERMAL
PROFILES WELL AND A MUCH EARLIER THAN EXPECTED TRANSITION TO
SNOW/MIXED PRECIP HAS OCCURRED. LATER TONIGHT AND TOMORROW THE MOST
UNCERTAINTY IS WITH CIG/VIS MAGNITUDE AND HOW FAST ANY IMPROVEMENT
MAY OCCUR.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 520 AM EST MON DEC 14 2015
THE SURFACE LOW OVER IOWA WILL MOVE NORTHEASTWARD ACROSS THE EASTERN
UP BY THIS AFTERNOON. NORTHEAST GALES WILL CONTINUE ACROSS THE NORTH
CENTRAL AND WESTERN LAKES TODAY AND EXPAND INTO THE SOUTH CENTRAL
AND EASTERN LAKES THIS AFTERNOON AND EVENING AS THE LOW MOVES
NORTHEAST OF THE AREA AND COLDER AIR FILTERS ACROSS THE LAKE. THERE
IS A POTENTIAL FOR A FEW STORM FORCE GUSTS THIS AFTERNOON BETWEEN
ISLE ROYALE AND THE KEWEENAW. WINDS WILL ONLY SUBSIDE TEMPORARILY ON
TUESDAY MORNING BEFORE ANOTHER LOW PRESSURE SYSTEM DEVELOPS AND MOVES
INTO THE UPPER GREAT LAKES FOR WEDNESDAY INTO THURSDAY. NORTHEAST
WINDS WILL INCREASE TO GALES OVER THE WEST HALF LATE TUE INTO WED
MORNING AND SOUTHEAST WINDS SHOULD REACH GALE FORCE OVER THE CENTRAL
AND EASTERN LAKE AHEAD OF THE LOW ON WEDNESDAY FOLLOWED BY WESTERLY
WINDS APPROACHING GALES IN THE COLD ADVECTION BEHIND THE LOW ON
THURSDAY INTO FRIDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 1 AM EST /MIDNIGHT CST/ TUESDAY
FOR MIZ002-009.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 AM EST TUESDAY FOR LSZ267.
GALE WARNING UNTIL 10 AM EST TUESDAY FOR LSZ265-266.
GALE WARNING UNTIL 9 AM EST /8 AM CST/ TUESDAY FOR LSZ162-263-
264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...MRD
AVIATION...TITUS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
406 PM CST MON DEC 14 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 406 PM CST MON DEC 14 2015
LOW THAT PASSED ACROSS THE SE TIP OF MN EARLIER TODAY IS NOW OVER
GREEN BAY. AS THE LOW HAS MOVED OFF TO THE EAST...WE HAVE SEEN A
DRASTIC DECREASE IN DEFORMATION FORCING...WITH A SIGNIFICANT AMOUNT
OF CLOUD TOP WARMING NOTED ON IR...WHICH HAS COINCIDED WITH A
RAPID DIMINISHING IN RADAR RETURNS. FORCING WITHIN THIS BAND WAS
ENOUGH TO COOL THE ATMOSPHERIC COLUMN DOWN WHERE THE HEAVIEST
RATES WERE SEEN TO CHANGE PRECIP OVER TO SNOW. HEAVIEST SNOW WAS
SEEN IN THE EAU CLAIRE AREA...WHICH PICKED UP AROUND AN INCH OF
SNOW. THE BIGGER STORY FOR EAU CLAIRE THOUGH IS THAT THE 1.85" OF
LIQUID PICKED UP THROUGH 3 PM TODAY NOT ONLY SET A NEW RECORD FOR
FOR THE DATE...BUT ALSO BROKE RECORDS FOR THE MOST PRECIP RECEIVED
IN A CALENDAR DAY FOR THE MONTH OF DECEMBER AND ANY CALENDAR DAY
DURING THE METEOROLOGICAL WINTER.
THE GOOD NEWS IS THIS PRECIP WILL BE DEPARTING THE ERN MPX CWA
AROUND 00Z AND WE WILL GET A SHORT BREAK FROM THE PRECIP. LOOKING
OUT WEST...YOU CAN SEE OUR NEXT STORM SYSTEM ACROSS UTAH AND THIS
WILL BE IMPACTING OUR AREA BEGINNING LATE TUESDAY
AFTERNOON...THOUGH THE BRUNT OF IT LOOKS TO COME TUESDAY NIGHT
INTO WEDNESDAY. THERE IS STILL A GOOD DEAL OF SPREAD IN THE
MODELS WITH WHEN PRECIP GETS HERE ON TUESDAY. GFS/NAM AND MOST OF
THE CAMS KEEP PRECIP OUT OF THE MPX CWA THROUGH 6 PM TUESDAY. THE
REASON FOR THIS CAN BE SEEN WHEN LOOKING AT 290-300K ISENTROPIC
SURFACES ON THE GFS/NAM...WHICH KEEP THE WAA BAND OF PRECIP SW OF
THE MPX AREA UNTIL AFTER 6 PM TUESDAY. DESPITE ALL OF THIS...THE
ECMWF AND SREF PROBS SHOW PRECIP SPREADING INTO WRN MN BETWEEN 21Z
AND 00Z. FOR POPS...REMOVED POPS BEFORE NOON...AND DELAYED THE
ARRIVAL OF CHANCE/LIKELY POPS UNTIL 3PM AND LATER.
LASTLY...RH TIME-HEIGHT PROFILES FROM THE GFS SUGGEST WE WILL NOT
GET A GLIMPSE OF CLOUD LESS SKIES UNTIL THIS WEEKEND...THIS WILL
ENSURE WE GET YET ANOTHER DAY WITH A VERY MINIMAL DIURNAL
TEMPERATURE RANGE...WITH LOWS IN THE LOW 30S AND HIGHS IN THE
MID/UPPER 30S ON TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 406 PM CST MON DEC 14 2015
THE MAIN WEATHER CONCERN IN THE LONGER TERM REMAINS THE SNOW
POTENTIAL DEVELOPING TUESDAY NIGHT INTO WEDNESDAY.
MODELS ARE IN GENERAL AGREEMENT OF LIFTING A DEEPENING AREA OF LOW
PRESSURE FROM COLORADO/WESTERN KANSAS REGION TUESDAY MORNING...TO
CENTRAL MN BY MIDDAY WEDNESDAY AND THEN NORTHEAST OVER LAKE
SUPERIOR BY WEDNESDAY NIGHT. TRACK OF THE SURFACE LOW AND VARIOUS
BOUNDARY LAYER TEMPERATURE/THICKNESS CONCERNS SHOW MOST OF THE
PRECIPITATION WILL REMAIN LIQUID OVER THE SOUTHEAST HALF OF THE
CWA FOR THIS EVENT. BEST ISENTROPIC LIFT ARRIVES TOWARD 12Z WED
INTO CENTRAL AREAS AND LIFTS NORTHEAST DURING THE MORNING. THIS IS
WHEN THE WARMER AIR LIFTS OUT WITH THE SURFACE LOW SO WE COULD
POSSIBLY SEE A BIT OF SLEET AND OR SNOW DURING THE MORNING COMMUTE
AS IT LIFTS OUT. THE HEAVIER SNOWS WILL FALL OVER THE NORTHWEST
CWA...WITH A 6 INCH SNOW TOTAL POSSIBLE OUT TOWARD KAXN-KMOX
REGION IN ABOUT 18 HOURS IN MORE FAVORABLE DEFORMATION AREA. THE
LATEST HOPWRF TIME SHIFTED 4KM INDICATES 4-5 INCHES CLIPPING THE
FAR NORTHWEST CWA...AND THE 12Z CIPS ANALOG HAZARD GUIDANCE WAS
SHOWING MAYBE 6 INCHES UP IN THE FAR NORTHWEST CORNER AS WELL. WE
WILL FORGO WINTER STORM WATCH FOR THE EVENT WITH THE HIGH
LIKELIHOOD OF AN ADVISORY BEING ISSUED FOR A PORTION OF THE
NORTHWEST CWA. NORTHWEST WINDS ARE EXPECTED TO INCREASE WEDNESDAY
MORNING/AFTERNOON BUT THE HEAVIER SNOW WILL LIKELY HAVE ENDED
BEFORE THE STRONGEST WINDS ARRIVE. THE HEAVIER/WET NATURE OF THE
SNOW SHOULD LIMIT SIGNIFICANT BLOWING/DRIFTING SNOW.
CLOUDS AND WIND WILL REMAIN INTO THURSDAY BEFORE DIMINISHING.
EXPECT SOME CLEARING INTO THURSDAY NIGHT OVER THE WEST AS THE
SURFACE RIDGE MOVES EAST. THIS SHOULD PROVIDE SINGLE DIGITS LOWS
OVER MOST OF THE WEST WITH THE FRESH SNOW COVER FORECAST. FLURRIES
OR SNOW SHOWERS WILL BE POSSIBLE OVER THE NORTHERN CWA THURSDAY AS
WELL AS THE UPPER TROUGH MOVES EAST AND STRONGER CAA DEVELOPS.
MODELS SHOW SLOW TEMPERATURE MODERATION INTO THE WEEKEND WITH THE
12Z ECMWF SHOWING ANOTHER POTENTIAL WAVE DEVELOPING NEXT MONDAY.
THE GFS IS NOT AS FAST IN DEVELOPING THE ENERGY TO THE EAST THAT
QUICKLY. LARGE MODEL SPREAD PRECLUDES MENTION OF ANYTHING FOR THIS
PERIOD AT THE MOMENT. WE`LL CONTINUE A DRY FORECAST FOR FRI-MON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1215 PM CST MON DEC 14 2015
CLOUD TOP TEMPERATURES BEGAN COOLING AT ABOUT 16Z OVER THE AREA
AND REFLECTIVITY IS NOW QUICKLY FOLLOWING THIS WEAKENING TREND WITH
THE BAND OF PRECIP ACROSS ERN MN AND WRN WI. HOWEVER...LIFT WAS
STRONG AND PERSISTENT ENOUGH TO COOL DOWN THE ATMOSPHERE ENOUGH TO
FORCE PRECIP OVER TO A RA/PL/SN MIX. THIS MIX WILL REMAIN UNTIL
PRECIP ENDS AT EACH LOCATION. THIS PRECIP IS DIMINISHING QUITE
QUICKLY THOUGH...SO FOLLOWED THE HRRR IDEA WITH THIS PRECIP BEING
LARGELY DOWN BY 22Z. FOR THE REST OF TONIGHT...STRATUS WILL REMAIN
IN PLACE...THOUGH EXPECT IT TO REMAIN MVFR. HOWEVER...WE WILL SEE
IFR CIGS OVER THE DAKOTAS WORK EAST WITH TIME...EVENTUALLY WORKING
INTO AXN/RWF AND POSSIBLY STC TONIGHT.
KMSP...PRECIP IS QUICKLY WINDING DOWN AND AS THE RATE
DECREASES...WE WILL SE P-TYPE GO BACK FROM SLEET TO RAIN. 21Z IS
LIKELY A LITTLE LONG TO RUN WITH PRECIP BASED ON CURRENT RADAR
TRENDS. FOR TONIGHT...FORECAST SOUNDING SUPPORT THE LAMP WITH
KEEPING CIGS MVFR...SO REMOVED IFR CIG MENTION 21Z TAFS HAD.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR. LIKELY -RA CHANGING TO -SN LATE. WINDS SE BCMG W
10-15 KTS.
THU...MVFR. SLIGHT CHC -SN. WINDS NW 15G25KTS.
FRI...MVFR CIGS. WINDS NW 15G26KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...DWE
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1215 PM CST MON DEC 14 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST MON DEC 14 2015
THE DEFORMATION AXIS OF PRECIPITATION ASSOCIATED WITH THE CLOSED LOW
CENTER LIFTING FROM THE MID MO/MS RIVER VALLEYS TO THE GREAT LAKES
HAS SOLIDIFIED OVER THE SOUTHEASTERN THIRD OF THE FORECAST AREA
EARLY THIS MORNING. QUITE AN ATYPICAL SCENARIO FOR MID DECEMBER...AS
THUS FAR THE PRECIP TYPE HAS BEEN ALL RAIN. THIS PRECIPITATION
SHIELD WILL CONTINUE TO GRADUALLY BACK WESTWARD THIS
MORNING...ULTIMATELY REACHING A REDWOOD FALLS TO MORA LINE. DO
EXPECT TO SEE SOME LIGHT SNOW MIX IN PRIOR TO THE PRECIPITATION
ENDING...WITH 14.06Z NAM AND SEVERAL HI-RES SOLUTIONS INDICATING 0-
6KM LAYER MAX WET BULB TEMPS TO DECREASE TO AROUND OR SLIGHTLY BELOW
ZERO FOR A SHORT TIME EARLY THIS AFTERNOON ALONG THE INTERSTATE 35
CORRIDOR NORTHEAST INTO WEST CENTRAL WI IN CONJUNCTION WITH THE
ARRIVAL OF THE STRONGER LIFT. NOT EXACTLY A FAVORABLE TIME FOR
LIQUID PRECIP TO TRANSITION TO SNOW AND ACCUMULATE...SO LIKELIHOOD
IS LOW ACCUMULATIONS WILL BE HIGHER THAN A COUPLE TENTHS OF AN INCH.
THE OTHER NOTABLE FACTOR TODAY IS THAT WINDS WILL CONTINUE TO PICK
UP AS THE RELATED SURFACE TROUGH INCHES INTO SOUTHEAST MN/CENTRAL
WI. SPEEDS WILL BE APPROACHING WIND ADVISORY CRITERIA
/30 MPH SUSTAINED/ WITH GUSTS TO AROUND OR JUST ABOVE 40 KTS. WILL
NOT ISSUE AN ADVISORY AT THIS POINT GIVEN ANTICIPATED SPEEDS ARE
BORDERLINE...AND THE ANTICIPATED DURATION OF THE HIGHEST WINDS IS
ONLY A FEW HOURS.
TEMPERATURES WILL REMAIN PRETTY STABLE OVER THE NEXT 24 HOURS GIVEN
THE EXTENSIVE CLOUD COVER. HIGHS WILL RANGE FROM THE LOWER 30S TO
LOWER 40S...AND LOWS TONIGHT IN THE UPPER 20S TO LOWER 30S.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 340 AM CST MON DEC 14 2015
MAIN FORECAST CONCERN DEALS WITH SNOWFALL POTENTIAL LATE TUESDAY
AFTERNOON...THRU WEDNESDAY MORNING BEFORE TAPERING OFF WEDNESDAY
AFTERNO0N AND EVENING.
MODELS CONTINUED TO ADVERTISE A POTENT WEATHER SYSTEM MOVING OUT
OF THE NORTHERN ROCKIES AND INTO THE PLAINS/UPPER MIDWEST TUESDAY
NIGHT/WEDNESDAY. BASED ON THE MOVEMENT/LOCATION OF THE SFC LOW AND
UPPER LEVEL FEATURES...PRECIPITATION WILL BEGIN IN WC/SW MN
TUESDAY EVENING AND SPREAD NE ACROSS SOUTHERN/CENTRAL MN.
THICKNESS VALUES/SFC WET BULB TEMPERATURES AND THE DEPTH OF THE
WARM LAYER MOVING BACK NORTHWARD ACROSS SOUTHERN/EASTERN MN AND
INTO WC WI TUESDAY NIGHT/WEDNESDAY...THE BULK OF ACCUMULATING
SNOWFALL WILL OCCUR FROM WC TO CENTRAL MN. HOWEVER...INITIALLY A
MIXTURE OF RAIN/SNOW OR ALL SNOW WILL OCCUR OVER SOUTHERN MN WHERE
CRITICAL TEMPERATURES IN THE FIRST 3K LAYER ARE COOL ENOUGH TO
SUPPORT SNOW. BUT AS WARMER AIR WRAPS NORTHWARD INTO THIS
SYSTEM LATE TUESDAY NIGHT/WEDNESDAY MORNING...THE SNOW WILL
CHANGE OVER TO RAIN/SNOW...THEN ALL RAIN BY WEDNESDAY MORNING AS
THE SFC LOW MOVES FROM NE IOWA...NORTHWARD INTO CENTRAL MN. ONCE
THE SFC LOW MOVES NE INTO NORTHERN WI/LAKE SUPERIOR...THE
PRECIPITATION WILL CHANGE BACK OVER TO SNOW. HOWEVER...BUT THE
TIME COLDER AIR ARRIVES...MOST OF THE PRECIPITATION WILL HAVE
ENDED. AGAIN...BASED ON TIMING/SFC TEMPS AND SNOWFALL RATIOS WHICH
WILL BE INITIALLY LOW...A BAND OF 4 TO 6 INCHES WILL FALL NE OF A
LINE FROM MADISON/APPLETON CITY...NE TO LITTLE FALLS. LOCALLY
HIGHER AMTS WILL BE POSSIBLE FURTHER NW INTO NW MN WHERE THE DEPTH
OF THE COLDER AIR IS GREATER. A WINTER STORM WATCH HAS BEEN ISSUED
FOR THIS AREA DUE TO THE POSSIBILITY OF 6-8 INCHES OF SNOW.
FURTHER TO THE SE...THE COMBINATION OF WARMER SFC TEMPS...MOSTLY
RAIN DURING THE BULK OF THE EVENT...AND LIMITED TIME FOR SNOWFALL
...LOCALLY ONE INCH WILL FALL. ANYWHERE FROM SOUTH CENTRAL TO
EAST CENTRAL MN...INCLUDING THE TWIN CITIES...SNOWFALL WILL BE
LESS THAN AN INCH.
ALTHOUGH THIS SYSTEM WILL NOT BRING LOTS OF SNOWFALL TO MPX
CWA...IT WILL BRING AN ABRUPT END TO THE MILD TEMPERATURES WE
HAVE BEEN EXPERIENCING. SOME LEFTOVER SNOW/SNOW SHOWERS WILL BE
POSSIBLE WEDNESDAY NIGHT/THURSDAY AS THIS SYSTEM SLOWLY WEAKENS
AND MOVES OFF INTO CANADA.
THE OVERALL PATTERN WILL AGAIN BUCKET BY THIS WEEKEND...WITH A
RETURN TO MODERATING TEMPERATURES. THERE IS ANOTHER STORM SYSTEM
THAT IS EXPECTED TO IMPACT THE UPPER MIDWEST AROUND THE 22/23TH OF
DECEMBER. LIKE WITH PREVIOUS SYSTEMS IN THE PAST MONTH...MILDER AIR
WORKING BACK NORTHWARD WILL AGAIN LEAD TO PRECIPITATION TYPE
CONCERNS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1215 PM CST MON DEC 14 2015
CLOUD TOP TEMPERATURES BEGAN COOLING AT ABOUT 16Z OVER THE AREA
AND REFLECTIVITY IS NOW QUICKLY FOLLOWING THIS WEAKENING TREND WITH
THE BAND OF PRECIP ACROSS ERN MN AND WRN WI. HOWEVER...LIFT WAS
STRONG AND PERSISTENT ENOUGH TO COOL DOWN THE ATMOSPHERE ENOUGH TO
FORCE PRECIP OVER TO A RA/PL/SN MIX. THIS MIX WILL REMAIN UNTIL
PRECIP ENDS AT EACH LOCATION. THIS PRECIP IS DIMINISHING QUITE
QUICKLY THOUGH...SO FOLLOWED THE HRRR IDEA WITH THIS PRECIP BEING
LARGELY DOWN BY 22Z. FOR THE REST OF TONIGHT...STRATUS WILL REMAIN
IN PLACE...THOUGH EXPECT IT TO REMAIN MVFR. HOWEVER...WE WILL SEE
IFR CIGS OVER THE DAKOTAS WORK EAST WITH TIME...EVENTUALLY WORKING
INTO AXN/RWF AND POSSIBLY STC TONIGHT.
KMSP...PRECIP IS QUICKLY WINDING DOWN AND AS THE RATE
DECREASES...WE WILL SE P-TYPE GO BACK FROM SLEET TO RAIN. 21Z IS
LIKELY A LITTLE LONG TO RUN WITH PRECIP BASED ON CURRENT RADAR
TRENDS. FOR TONIGHT...FORECAST SOUNDING SUPPORT THE LAMP WITH
KEEPING CIGS MVFR...SO REMOVED IFR CIG MENTION 21Z TAFS HAD.
/OUTLOOK FOR KMSP/
WED...MVFR/IFR. LIKELY -RA CHANGING TO -SN LATE. WINDS SE BCMG W
10-15 KTS.
THU...MVFR. SLIGHT CHC -SN. WINDS NW 15G25KTS.
FRI...MVFR CIGS. WINDS NW 15G26KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...LS
LONG TERM...JLT
AVIATION...MPG
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
156 PM CST MON DEC 14 2015
.SHORT TERM: (Through Late This Afternoon)
Issued at 335 AM CST Mon Dec 14 2015
Although the period of steady rain has ended now that the axis
of strongest moisture convergence has progressed eastward, scattered
to numerous showers were still occurring early this morning farther
back over MO/KS/AR/OK. These showers are associated with the upper
low center, which was located near the MO/KS border at 09z per
satellite imagery and RAP analyses. These showers will accompany the
upper low today as it tracks northeastward from MO into IL/WI,
leading to periods of rain across MO/IL. Simultaneously, a vort lobe
rotating around the back side of the departing upper low may bring
an increased chance of showers to parts of northeast MO/west central
IL this aftn. The PoP grids attempt to reflect this complexity.
Stronger winds aloft will be transported down to the surface today,
leading to windy conditions at times. Both sustained winds and gusts
appear to remain below advisory criteria attm.
Non-diurnal temperatures are expected again today due to the
competing influences of CAA behind a cold front, diurnal warming,
and lingering precip/cloud cover.
Kanofsky
.LONG TERM: (Tonight through Sunday)
Issued at 335 AM CST Mon Dec 14 2015
(Tonight)
Dry weather is in the offing for the area as relatively narrow NW-SE
oriented surface ridge in the wake of today`s system passes through
the region. Primary question is cloud trends, and although the
tendency should be a clearing of the post system low cloudiness from
SW to NE guidance varies a great deal on how quickly this will
occur. MOS output based on the NAM...with its typically moist low
levels...holds onto a good deal of low cloudiness into Tuesday
morning, while GFS MOS certainly suggests a decrease in the cloud
cover. Given that the low level wind forecasts have a pronounced
westerly component that should aid in clearing of the low
cloudiness, will lean towards trends suggested by GFS MOS. Some
fog is certainly possible as well given the water-logged ground
across the region and decreasing winds as the surface ridge works
into the area, but will let day shift take another look at
this before including in forecast.
(Tuesday-Wednesday)
Heading into the middle of the week attention turns to potent and
fast moving upper level system that migrates from the central Plains
into the upper Mississippi Valley Tuesday afternoon-Wednesday
afternoon. With forcing well to the north and with limited moisture
return, it still appears rain threat with this system will be rather
low. Overall forecast trends remain the same, although did attempt
to fine-tune the timing of the rain threat just a bit due to the
good agreement in the 00z solutions WRT movement of upper level
features as well as surface cold front.
(Thursday-Sunday)
No major changes in forecast specifics during this time frame, with
all NWP solutions still indicating deep upper trof developing over
the central CONUS Thursday-Friday. The drop in heights over the
region should finally allow a much more typical early winter AMS to
settle into the mid Mississippi Valley, with 850mb temps of at
least -10C progged into the area by Friday morning. This cool
down should bring the CWA its first real taste of winter
temperatures with highs in the 30s to low 40s by Friday...first
time temps have been near or below their daily averages since
early this month.
However, it appears that these winter temperatures will be short-
lived, as progressive UA pattern allows strong ridging to build back
across the central CONUS during the upcoming weekend as deep trof
works its way into the eastern U.S. AMS over the region should
modify quickly during this transition, and the main question is
how fast this modification will occur. If tonight`s medium range
solutions are correct warmup could begin already on Saturday, but
given the fact that models are often too fast in a high amplitude
regime will keep Saturday`s temps on the cool side, and begin the
warmup in earnest on Sunday, with highs returning to the 40s and
50s.
It still appears that dry conditions will dominate the CWA during
the Thursday-Sunday temperature roller coaster.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Tuesday Afternoon)
Issued at 148 PM CST Mon Dec 14 2015
Looking at short range models, mvfr cigs to persist through the
night at taf sites. So kept everyone overcast til mid morning on
Tuesday then begin scattering out. Some concern about fog chances
as there is plenty of low level moisture, light winds and a
decent inversion. If clouds remain over region, fog would be less
likely, but will need to keep an eye out. As for winds, gusty
southwest to west winds to persist til 01z-02z Tuesday, then
diminish and become light and variable towards daybreak. On
Tuesday, surface ridge moves off to the east allowing winds to
become southeasterly and pickup to near 10 kts.
Specifics for KSTL:
Looking at short range models, mvfr cigs to persist through the
night in metro area. So kept overcast til 15z Tuesday then begin
scattering out. Some concern about fog chances as there is plenty
of low level moisture, light winds and a decent inversion. If
clouds remain over region, fog would be less likely, but will
need to keep an eye out. As for winds, gusty southwest to west
winds to persist til 01z Tuesday, then diminish and become light
and variable around 09z Tuesday. On Tuesday, surface ridge moves
off to the east allowing winds to become southeasterly and pickup
to near 10 kts.
Byrd
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BILLINGS MT
337 PM MST MON DEC 14 2015
.SHORT TERM...VALID FOR TUE AND WED...
WSR88D RADAR REFLECTIVITY DEPICTING FAIRLY HEAVY SNOWBANDS
CENTERED DIRECTLY OVER BILLINGS AT 330PM. AROUND 3 INCHES HAS
FALLEN AT THE NWS OFFICE SINCE NOON AND IT CONTINUES TO COME DOWN
STEADILY.
THE HRRR DID A VERY GOOD JOB OF KEEPING THE SNOW CONFINED FROM
BILLINGS WEST UNTIL 1100AM DUE TO THE CONTINUAL PUSH OF DRYER AIR
FROM THE EAST. IT ALSO DID A GREAT JOB IN TIMING THE LOWERING
VISIBILITIES AT ALL THE TAF SITES.
ON THE LARGER SCALE...THE WESTERN US CONTINUES TO BE UNDER THE
INFLUENCE OF A LONG WAVE TROUGH. A MID LEVEL LOW CIRCULATION IS
PROGGED TO MOVE OVER WESTERN KANSAS AND CENTRAL NEBRASKA BY EARLY
WEDNESDAY. THE MOISTURE FETCH IS QUITE IMPRESSIVE FOR THIS TIME OF
YEAR...KEEPING QPF VALUES VERY HIGH OVER THE NORTHERN ROCKIES. THE
INTERESTING THING TO NOTE IS THERE IS A LACK OF STRONG UPPER LEVEL
DYNAMIC FORCING WITH THIS SYSTEM. SO PRODUCING THESE TYPES OF SNOW
AMOUNTS IS QUITE IMPRESSIVE.
WITH RESPECT TO THE ONGOING HIGHLIGHTS...THE TIMING ON THE WINTER
WEATHER WARNINGS ARE IN GOOD SHAPE. WITH THIS FORECAST
PACKAGE...DECIDED TO TREND THE SNOWFALL AMOUNTS FOR AREAS FROM
BILLINGS EAST DOWN EVER SO SLIGHTLY. AREAS WEST OF BILLINGS HAVE
BEEN REPORTING ONGOING SNOW TOTALS ON THE ORDER OF 5 TO 6 INCHES.
ALSO...WENT AHEAD AND UPGRADED THE WINTER STORM WATCH TO AN
ADVISORY FOR BOTH FALLON AND CARTER COUNTIES IN EASTERN MONTANA IN
COORDINATION WITH SURROUNDING WFOS. THE SNOW WILL START LATER
THERE AND LAST UNTIL EARLY WEDNESDAY MORNING. EXPECTING THE SNOW
TO END OVER SOUTH CENTRAL MONTANA TO END TUESDAY MORNING.
ROAD CONDITIONS WILL BE THE MAIN IMPACT AND THREAT THIS EVENING.
A FEW VEHICLE SLIDE OFFS HAVE BEEN REPORTED ON INTERSTATE 90 NEAR
BILLINGS AND HIGHWAY 212 NEAR JOLIET. EARLIER SNOWFALL MAY HAVE
MELTED AND REFROZE UNDER A LAYER OF NEW SNOWFALL. ROADS WILL
REMAIN SLICK AND SOMEWHAT SNOWPACKED THROUGH TOMORROW. SINGER
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
UPPER-LEVEL RIDGE APPROACHING FROM THE WEST AND ASSOCIATED
SUBSIDENCE BRING DRY WX TO MUCH OF THE REGION THU AND FRI. WESTERN
ZONES GET UNDER MORE OF A CYCLONIC FLOW LATE FRI AND
SAT...ALLOWING FOR CHANCE OF RAIN/SNOW SHOWERS THERE. SHORTWAVE
TROUGH THEN CROSSES THE REGION ALLOWING FOR LOW-CHANCE POPS LATE
SAT NIGHT AND SUN. THEN FOR MON...GFS BRINGS ANOTHER SHORTWAVE
ACROSS THE REGION WITH ADDITIONAL PRECIP BUT EURO KEEPS REGION
UNDER MORE OF A WEAK SHORTWAVE RIDGING SCENARIO WITH PRECIP
CONFINED TO SW MOUNTAINS. FOR NOW WILL LEAVE OUT PRECIP FOR MOST
OF CWA ON MON.
EXPECT THE COLDEST TEMPERATURES OF THE WEEK ON THURSDAY WITH
READINGS 10-20 DEGREES BELOW NORMAL. THEN AS THE FLOW BECOMES
WESTERLY/SOUTHWESTERLY ON FRIDAY TEMPERATURES MODERATE AND WINDS
WILL INCREASE ESPECIALLY FOR THE GAP FLOW AREAS. COULD BE SOME
AREAS OF BLOWING SNOW BUT IT SEEMS LIKE A SHORT WINDOW GIVEN HOW
QUICKLY TEMPERATURES WANT TO CLIMB ABOVE FREEZING. SATURDAY WILL
BE EVEN WARMER WITH NEAR FREEZING LOWS CONTRIBUTING STRONGLY TO
SNOW MELT. A SLOW COOLING TREND EXPECTED FOR SUNDAY AND MONDAY.
RMS/SINGER
&&
.AVIATION...
MODERATE TO HEAVY SNOW IS ONGOING ACROSS THE FORECAST AREA AND
MOST TERMINALS ARE IN LIFR AND IFR CIGS AND VIS. TWO EXCEPTIONS
ARE KSHR...WITH MVFR...AND KMLS WITH VFR CONDITIONS. MODERATE IFR
SNOW BANDS WILL HOLD OFF UNTIL LATER THIS EVENING AT THESE
TERMINALS WITH KSHR LIKELY SEEING HEAVIER SNOW AFTER 00Z AND KMLS
SEEING THESE CONDITIONS AFTER 03Z. FOR KBIL AND KLVM IFR AND LIFR
CONDITIONS WILL PERSIST THROUGH AT LEAST 06Z TONIGHT BEFORE THE
HEAVIEST SNOW BANDS PUSH EAST AND SOUTHEAST OF THESE TERMINALS.
DOBBS
&&
.PRELIMINARY POINT TEMP/POPS...
TUE WED THU FRI SAT SUN MON
-----------------------------------------------------------
BIL 021/026 014/026 005/016 006/038 030/043 030/040 024/040
+6/S 23/J 21/B 11/E 11/B 12/J 11/B
LVM 014/026 012/023 001/017 017/043 035/042 034/035 024/038
+4/S 33/J 31/B 12/J 11/N 32/J 13/J
HDN 020/030 010/028 000/022 905/038 017/044 026/045 014/044
+7/S 34/J 21/B 11/B 11/B 12/J 11/B
MLS 022/029 011/026 003/017 902/032 016/039 020/042 015/039
97/S 42/J 21/B 11/B 11/B 12/J 11/B
4BQ 022/029 013/025 009/018 004/036 021/043 025/044 017/042
99/S 62/J 21/B 11/B 11/B 12/J 11/B
BHK 019/028 013/023 006/017 903/028 015/040 018/040 014/037
77/S 53/J 21/B 11/B 11/B 12/J 01/B
SHR 018/027 013/027 006/022 006/041 022/047 023/041 016/045
++/S 62/J 22/J 11/B 11/B 12/J 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER STORM WARNING IN EFFECT UNTIL 6 PM MST TUESDAY FOR
ZONES 28-29-34-35-39>42-56-63>68.
WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MST TUESDAY
NIGHT FOR ZONES 30>32-36-38-57-58.
WINTER WEATHER ADVISORY IN EFFECT FROM 11 PM THIS EVENING TO
5 AM MST WEDNESDAY FOR ZONES 33-37.
WY...WINTER STORM WARNING IN EFFECT UNTIL MIDNIGHT MST TUESDAY
NIGHT FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS MEDFORD OR
910 AM PST MON DEC 14 2015
.DISCUSSION...THE UPPER TROUGH HAS PUSHED SOUTHEAST INTO CENTRAL
NEVADA. ON THE BACKSIDE IS A MOIST NORTH TO NORTHWEST FLOW AND ONE
MORE DISTURBANCE WILL MOVE THROUGH THIS AFTERNOON BRINGING A NET
INCREASE IN SHOWER ACTIVITY MAINLY WEST OF THE CASCADES THIS
AFTERNOON. SNOW LEVELS SHOULD COME UP TO AROUND 2000 FEET THIS
AFTERNOON AND ROAD SURFACE WILL WARM UP TO LIMIT ANY ROAD SNOW
IMPACTS. THERE WON`T BE ENOUGH SNOW TO WARRANT A NEW ADVISORY AT
HIGHER ELEVATION SPOTS LIKE SISKIYOU SUMMIT, BUT TRAVEL STILL MAY
BE HAZARDOUS OVER THE PASS. PREVIOUS FORECAST FOR THIS MORNING IS
ON TRACK AND NO CHANGES ARE NEEDED.
ONE ITEM OF CONCERN FROM ABOUT MID WEEK INTO NEXT WEEKEND WILL BE
THE POTENTIAL FOR FLOODING. THE MODELS YESTERDAY AND SO FAR THIS
MORNING ARE HINTING AT ANOTHER SIGNIFICANT RAIN EVENT WITH HIGHER
SNOW LEVELS. WITH THE GROUND ALREADY SATURATED, MELTING SNOWPACK
AND HEAVY RAIN COULD VERY WELL RESULT IN RENEWED FLOODING
CONCERNS. -PETRUCELLI
&&
.AVIATION...FOR THE 14/12Z TAF CYCLE...NUMEROUS TO WIDESPREAD RAIN
AND SNOW SHOWERS FROM THE CASCADES WESTWARD ARE EXPECTED THROUGH
THIS AFTERNOON...THEN SHOWERS WILL BECOME SCATTERED DURING THE
EVENING. FROM THE CASCADES WEST...THIS WILL CREATE A MIX OF IFR AND
MVFR CIGS WITH PERIODS OF MOUNTAIN OBSCURATIONS THROUGH THIS
EVENING. EAST OF THE CASCADES...CONDITIONS WILL BE MAINLY VFR WITH
ISOLATED SNOW SHOWERS AND MVFR CEILINGS. SHOWERS WILL TAPER OFF
OVERNIGHT WITH VFR CONDITIONS DEVELOPING EXCEPT FOR IFR/MVFR VALLEY
LOW CLOUDS AND FOG FORMING WEST OF THE CASCADES AND POSSIBLY IN THE
KLAMATH BASIN. /CC
&&
.MARINE...UPDATED 800 AM PST MONDAY 14 DEC 2015...GUSTY NORTHWEST
WINDS WILL BRIEFLY LOWER LATE THIS MORNING THEN INCREASE AGAIN THIS
AFTERNOON THROUGH THIS EVENING. VERY STEEP SEAS WILL CONTINUE TODAY
INTO THIS EVENING. SEAS WILL GRADUALLY LOWER BUT WILL REMAIN STEEP
THROUGH TUESDAY MORNING. HIGH AND VERY LONG PERIOD SWELL IS EXPECTED
TO BUILD INTO THE WATERS WEDNESDAY MORNING. A SERIES OF FRONTS WILL
MOVE INTO THE AREA LATER HIS WEEK...WITH PERIODS OF STRONG GUSTY
SOUTH WINDS AND STEEP TO VERY STEEP SEAS EXPECTED. -BPN/CC
&&
.PREV DISCUSSION... /ISSUED 402 AM PST MON DEC 14 2015/
DISCUSSION...IN THE WAKE OF YESTERDAY`S STORM...WE ARE NOW IN
A COLD NORTH TO NORTHWEST FLOW ALOFT. THERE ARE STILL A COUPLE OF
DISTURBANCES THAT WILL MOVE THROUGH ON THE BACK SIDE OF AN UPPER
LEVEL TROUGH, THE AXIS OF WHICH IS CENTERED OVER IDAHO AND NEVADA
EARLY THIS MORNING.
THE FIRST DISTURBANCE IS MOVING THROUGH NOW WITH NUMEROUS SHOWERS
OCCURRING FROM THE CASCADES AND SISKIYOUS NORTH AND WEST. SNOW
LEVELS ARE RUNNING ABOUT 1500 TO 2000 FEET...THOUGH THEY COULD BE
LOCALLY DOWN AS LOW AS 1000 FEET IN HEAVIER SHOWERS. SOME SHOWERS
MAY ALSO MAKE IT SOUTH AND EAST OF THE MOUNTAINS, BUT THESE WILL
BE SCATTERED AT BEST. A WINTER WEATHER ADVISORY AT WSWMFR REMAINS
IN EFFECT THIS MORNING OVER THE WEST SIDE. THE BEST CHANCE FOR AN
INCH OR TWO OF NEW SNOW WILL BE ON THE NORTH AND WEST FACING
SLOPES OF JACKSON AND JOSEPHINE COUNTIES AS WELL AS THE UMPQUA
DIVIDE, MAINLY ABOVE 1500 FEET. THE MAIN PASSES ON INTERSTATE 5 IN
OREGON COULD BE IMPACTED BY THESE HEAVIER SNOW SHOWERS.
THE LATEST HRRR IS SHOWING ANOTHER DISTURBANCE MOVING IN THIS
AFTERNOON, WHICH WILL KEEP SHOWERS GOING INTO THE EVENING HOURS,
BUT SNOW LEVELS SHOULD RISE TO NEAR 2000 FEET WEST OF THE CASCADES
AND ROAD SURFACE TEMPERATURES SHOULD WARM ENOUGH TO PRECLUDE
SIGNIFICANT SNOW IMPACTS AT THE LOWER ELEVATIONS. THERE WON`T BE
ENOUGH SNOW TO WARRANT A NEW ADVISORY AT HIGHER ELEVATION SPOTS
LIKE SISKIYOU SUMMIT, BUT TRAVEL STILL MAY BE HAZARDOUS OVER THE
PASS.
AN UPPER RIDGE OFFSHORE WILL BEGIN TO BUILD INTO THE AREA TONIGHT.
PARTIAL CLEARING IN THE EVENING WEST OF THE CASCADES WILL ALLOW
AREAS OF LOW CLOUDS AND FOG TO DEVELOP IN THE VALLEYS. TUESDAY
WILL BE A DRY DAY FOR MOST AREAS, THOUGH THERE MAY BE SOME LIGHT
RAIN OVER THE COASTAL WATERS AND NEAR REEDSPORT AND FLORENCE.
THE NEXT SIGNIFICANT WEATHER SYSTEM WILL APPROACH THE AREA
WEDNESDAY SENDING A WET WARM FRONT THROUGH THE AREA WEDNESDAY
NIGHT. THE 00Z GFS20 BRINGS PRECIPITATION ONSHORE WEDNESDAY
AFTERNOON AND IS ABOUT 6 HOURS FASTER THAN 00Z ECMWF. EITHER WAY,
SIGNIFICANT RAINFALL IS EXPECTED ACROSS MOST OF THE AREA WITH THE
FRONT WEDNESDAY NIGHT. SNOW LEVELS WILL BE A BIT HIGHER WITH THIS
SYSTEM STARTING NEAR 3500 FEET WEDNESDAY EVENING, THEN SURGING TO
AROUND 7000-7500 FEET BY THURSDAY EVENING. SNOW IMPACTS SHOULD BE
RESERVED FOR THE HIGHEST ELEVATIONS. SIMILAR TO THE MOST RECENT
STORM, THE WARM FRONT WILL BE FOLLOWED BY ANOTHER WET COLD FRONT
THAT WILL PUSH VERY SLOWLY THROUGH THE AREA THURSDAY THROUGH
FRIDAY NIGHT, BRINGING A RENEWED THREAT OF SIGNIFICANT RAINFALL ON
ALREADY SATURATED SOILS. SINCE RIVERS, CREEKS AND STREAMS WILL
STILL BE RUNNING RELATIVELY HIGH AND LOWER ELEVATION SNOW WILL
LIKELY MELT, WE EXPECT HYDROLOGY ISSUES ONCE AGAIN. THE UPPER
TROUGH WITH THIS SYSTEM WILL LIKELY SPLIT AS IT MOVES OVER THE
AREA SATURDAY AND PRECIPITATION WILL GRADUALLY TAPER OFF SOUTH AND
EAST OF THE CASCADES AND END SATURDAY NIGHT. THERE WON`T BE MUCH
OF A BREAK THOUGH...SINCE THE NEXT SYSTEM IS EXPECTED TO MOVE IN
SUNDAY. SPILDE
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1000
FEET FOR FOR ORZ023.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING FOR ORZ025.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1000
FEET FOR FOR ORZ024.
WINTER WEATHER ADVISORY UNTIL 10 AM PST THIS MORNING ABOVE 1500
FEET FOR FOR ORZ026.
CA...NONE.
PACIFIC COASTAL WATERS...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM 10 PM THIS EVENING
TO 10 AM PST TUESDAY FOR PZZ350-356-370-376.
HAZARDOUS SEAS WARNING UNTIL 10 PM PST THIS EVENING FOR
PZZ350-356-370-376.
$$
AREA FORECAST DISCUSSION
NWS PORTLAND OR
859 AM PST MON DEC 14 2015
.SYNOPSIS...SCATTERED RAIN AND MOUNTAIN SNOW SHOWERS PERSIST AS A
COOL UPPER LEVEL TROUGH MOVES THROUGH THE PAC NW TODAY. WEAK LOW
PRESSURE OFF THE WA COAST WILL DROP SOUTHEAST TODAY...BRINGING A
BATCH OF STEADIER PRECIPITATION TO THE OREGON COAST AND COAST RANGE.
SNOW LEVELS WILL BE 1500-2000 FEET IN THE COAST RANGE AS THIS OCCURS
FOR SOME ACCUMULATING SNOW THIS MORNING. HIGH PRESSURE WILL TAKE OVER
TONIGHT...AND CLEARING SKIES COULD LEAD TO SOME VALLEY FOG AND A
LITTLE BLACK ICE IN THE COLDER SPOTS TONIGHT AND TUE MORNING. HIGH
PRESSURE SHOULD KEEP TUESDAY MOSTLY DRY...THEN RAIN CHANCES INCREASE
AGAIN TUESDAY NIGHT AND WEDNESDAY AS WEAK FRONT CLIPS THROUGH
WASHINGTON AND NORTHERN OREGON. THE NEXT STRONG FRONTAL SYSTEM WILL
LIKELY BRING HEAVIER RAIN BACK TO THE REGION LATER WEDNESDAY THROUGH
THURSDAY...WITH SNOW IN THE CASCADES. ENOUGH COLD AIR MAY LINGER FOR
WINTRY PRECIPITATION IN THE HOOD RIVER VALLEY WITH THIS SYSTEM. COOL
AND UNSETTLED WEATHER IS EXPECTED TO FOLLOW INTO THE WEEKEND...WITH
ADDITIONAL SNOW POSSIBLE FOR THE CASCADES.
&&
.UPDATE...RADAR SHOWS A BATCH OF SHOWERS MOVING THROUGH THE COAST
RANGE AND ACROSS THE VALLEY. FROM OBSERVATIONS IN THE COAST RANGE
THE SNOW LEVEL MAY BE DOWN TO 1500 FEET BUT MAY BE MORE OF A MIX OF
RAIN AND SNOW. 2000 FEET AND ABOVE APPEARS WHERE SNOW ACCUMULATION
IS OCCURRING. SNOW ADVISORY FOR THE COAST RANGE LOOKS GOOD AND WILL
KEEP IT GOING...BUT IT MAY BE EXPIRED SOONER THAN THE CURRENT TIMING
DEPENDING ON THE SPEED OF THE SYSTEM. THIS BATCH OF SHOWERS WILL
MOVE SOUTH AND EAST AND WEAKEN TODAY. MAY EVEN SEE SOME SUNSHINE
FOR THE FAR NORTHERN ZONES LATER TODAY.
&&
.PREV DISCUSSION... /ISSUED 306 AM PST MON DEC 14 2015/
SHORT TERM...TODAY THROUGH WEDNESDAY...UNSETTLED WEATHER CONTINUES
THIS MORNING WITH SCATTERED SHOWERS ACROSS SW WASHINGTON AND NW
OREGON...MAINLY DUE TO AN UPPER TROUGH MOVING THROUGH THE PAC NW.
SOME STEADIER ECHOES ARE STARTING TO SHOW UP ON KLGX NWS DOPPLER
RADAR...ASSOCIATED WITH WEAK LOW PRESSURE OFF THE WA COAST. AS THE
LOW MOVES S-SE...EXPECT STEADIER PRECIP TO MOVE ONSHORE SOUTH OF
ABOUT TILLAMOOK THIS MORNING. PAST FEW HRRR RUNS HAVE SHOWN A SWATH
OF MODERATE PRECIP MOVING INTO THE CENTRAL COAST AND COAST RANGE OF
OREGON AROUND 7 AM...CONTINUING UNTIL ABOUT NOON AS A 1019 MB LOW
MOVES THROUGH THE AREA. OTHERWISE...SHALLOW INSTABILITY WILL PROBABLY
KEEP SCATTERED SHOWERS AROUND WELL INTO THE DAY. HIGHER PRESSURE BOTH
AT THE SURFACE AND ALOFT WILL LIKELY CAUSE SUBSIDENCE AND DRYING
LATER THIS AFTERNOON AND EVENING...WITH WARMER AIR ALOFT INCREASINGLY
CAPPING ANY SHALLOW CONVECTION AND BRINGING SHOWER ACTIVITY TO AN
END.
SKIES MAY CLEAR A BIT TONIGHT AS HIGH PRESSURE BUILDS IN AND
NORTHERLY FLOW DEVELOPS. THE NORTHERLY FLOW SHOULD KEEP THE BOUNDARY
LAYER BARELY MIXED ENOUGH TO PREVENT WIDESPREAD FOG...BUT SOME
PATCHES WILL PROBABLY DEVELOP IN THE MORE FOG-PRONE SHELTERED VALLEYS
DUE TO THE VERY WET GROUND. MOS TEMPS ARE BELOW FREEZING TONIGHT IN
THE COOLER VALLEY SPOTS...SO THERE MAY BE SOME BLACK ICE TONIGHT/
EARLY TUE MORNING WHERE ROADS REMAIN WET FROM ALL THE RECENT
RAIN WE HAVE HAD.
SUNDAY DECEMBER 13 WAS THE 13TH DAY IN A ROW WITH MORE THAN A QUARTER
INCH OF RAIN AT KPDX...BREAKING THE PREVIOUS RECORD OF 11 DAYS SET
JANUARY 16-26 1970. THERE IS A DECENT CHANCE THAT TODAY WILL BREAK
THAT STREAK. IF NOT TODAY...TUESDAY SHOULD BREAK THE STREAK AND MAY
ACTUALLY BE TOTALLY DRY FOR MUCH OF THE FORECAST AREA AS HIGH
PRESSURE BRIEFLY BUILDS INTO THE PAC NW. THIS IS BY NO MEANS A
CERTAINTY...AS A WEAK COLD FRONT IS FCST TO CLIP WA/N OR TUE NIGHT
INTO WED AND MAY BRING SOME SHOWERS BACK TO OUR NORTHERN ZONES.
THE TUE NIGHT/EARLY WED COLD FRONT IS FAIRLY IMPORTANT...AS IT MAY
RECHARGE THE COLD AIR EAST OF THE CASCADES AND SET UP A WEAK
BAROCLINIC ZONE OVER NORTHWEST OF WEST-CENTRAL OREGON. IF THIS COLD
AIR GETS INTO THE HOOD RIVER VALLEY AND EASTERN SKAMANIA COUNTY...IT
MAY END UP STUCK THERE AS A MUCH STRONGER AND WETTER SYSTEM ARRIVES
WED NIGHT/THU. THE BAROCLINIC ZONE WOULD ALSO PROVIDE AN OVERRUNNING
SURFACE FOR THE MOIST AND RELATIVELY WARM ATMOSPHERIC RIVER ARRIVES
LATE WED. THE RESULTING ISENTROPIC LIFT COULD YIELD ANOTHER ROUND OF
HEAVY RAIN FOR MUCH OF THE FORECAST AREA LATE WED INTO THU. PREFER
THE 00Z GFS SOLUTION...AS THE RELATIVELY DRIER/SLOWER 12Z/00Z ECMWF
HAS BEEN A BIT OF AN OUTLIER AMONGST ITS OWN ENSEMBLE MEMBERS. IF THE
GFS QPF VERIFIES...THERE MAY BE ANOTHER ROUND OF HYDROLOGIC PROBLEMS
ACROSS MUCH OF OUR FORECAST AREA WED NIGHT/THU...IN ADDITION TO HEAVY
SNOW AND/OR ICE IN THE HOOD RIVER VALLEY AND EASTERN SKAMANIA COUNTY.
WHILE CONFIDENCE IS INCREASING THAT THIS WEEK WILL BE ANOTHER ACTIVE
ONE WITH A VARIETY OF WEATHER CONCERNS...DETAILS MAY STILL CHANGE AS
FUTURE MODEL RUNS COME IN. STAY TUNED.WEAGLE
LONG TERM...WEDNESDAY NIGHT THROUGH SUNDAY...CONFIDENCE IS GROWING
THAT YET ANOTHER ATMOSPHERIC RIVER EVENT WILL HAMMER THE PAC NW WITH
HEAVY RAIN WED NIGHT AND THURSDAY...POSSIBLY LINGERING INTO FRIDAY.
THIS IS NOT AN OPPORTUNE TIME FOR THIS TO OCCUR AS RIVERS WILL STILL
BE HIGH AND THE GROUND SATURATED FROM LAST WEEK. THE 00Z 4 KM UW
WRF-GFS ALREADY HAS 2-5 INCHES OF QPF FROM THIS SYSTEM IN THE HIGHER
TERRAIN BY THE END OF THE RUN AT 12Z THU...WITH ABOUT AN INCH IN THE
LOWLANDS. THE 12Z/00Z ECMWF HAVE BEEN NOTABLY SLOWER/DRIER THAN THE
U.S. MODELS...BUT AT LEAST THE 00Z ECMWF IS SOMEWHAT OF AN OUTLIER
AMONGST ITS ENSEMBLE MEMBERS WITH MOST ENSEMBLES BRINGING RAIN IN
AROUND THE SAME TIME AS THE 00Z GFS. THE 06Z GFS DOES NOT TAKE ITS
FOOT OFF THE ACCELERATOR...REMAINING CONSISTENT WITH PREVIOUS RUNS.
AFTER COORDINATION WITH WPC AND OUR SURROUNDING OFFICES...DECIDED TO
DISREGARD THE DRIER ECMWF RUNS AND OUR FORECAST BRINGS IN SIGNIFICANT
QPF BY WED NIGHT. WILL HOLD OFF ON ISSUING A HYDROLOGIC STATEMENT FOR
NOW...BUT IF THE 12Z ECMWF COMES IN LINE WITH THE WETTER U.S. MODELS
FUTURE SHIFTS MAY WANT TO DO SO. IF THE 00Z GFS IS TO BE BELIEVED...
THE HIGHER TERRAIN MAY SEE ANOTHER 5-10 INCHES OF RAIN LATE WED-
FRI...WITH ANOTHER 2-4 INCHES IN THE INTERIOR LOWLANDS INCLUDING THE
HOOD RIVER VALLEY.
WITH COLD AIR POSSIBLY TRAPPED IN THE HOOD RIVER VALLEY AND EASTERN
SKAMANIA COUNTY...THERE IS THE POTENTIAL FOR HEAVY SNOW OR ICE AT
LEAST IN THE HIGHER PORTIONS OF THOSE VALLEYS. WHILE SNOW LEVELS
WILL BE RISING IN GENERAL...THEY MAY BE MORE STUBBORN NORTH OF
SANTIAM PASS. THIS COULD LEAD TO A DECENT AMOUNT OF SNOW FOR MOUNTS
HOOD AND ADAMS...WHILE MOUNT ST. HELENS AND THE LANE COUNTY CASCADES
SEE MAINLY RAIN OR MIXED RAIN/SNOW. STILL TOO EARLY TO SORT OUT THESE
DETAILS PRECISELY AND MUCH MAY CHANGE BETWEEN NOW AND THURSDAY.
THE BAROCLINIC ZONE WILL LIKELY SHIFT SOUTHWARD FRIDAY...PUSHING THE
HEAVIEST RAIN SOUTH TOWARD THE OR/CA BORDER. MODELS SHOW DECENT
AGREEMENT THAT ANOTHER COOL UPPER TROUGH WILL MOVE ACROSS THE PAC NW
BEHIND THIS...FOR MORE SHOWERS FRI/SAT. THE NEXT FRONT MAY ARRIVE AS
EARLY AS SAT NIGHT/SUN FOR MORE RAIN AND MOUNTAIN SNOW. BOTTOM LINE
IS...THERE IS NO END IN SIGHT TO OUR VERY ACTIVE DECEMBER WEATHER...
AT LEAST NOT FOR THE NEXT 7-10 DAYS. WEAGLE
&&
.AVIATION...A SHOWERY UNSTABLE AIRMASS WILL LEAD TO PRIMARILY VFR
CONDITIONS TODAY WITH OCCASIONAL MVFR CONDITIONS BETWEEN 17Z AND
21Z MONDAY. THE PRIMARY EXCEPTION TO THIS WILL LIKELY BE AT KONP
AND POSSIBLY KEUG WHERE WEAK WARM FRONTAL LIFT MAY PRODUCE A MORE
EXTENDED PERIOD OF MVFR AND HIGH END IFR CONDITIONS. THE EXTENT OF
CLEARING THIS EVENING REMAINS SOMEWHAT UNCERTAIN...BUT CURRENT
THINKING IS THAT THERE SHOULD BE ENOUGH THAT MOST LOCATIONS SHOULD
DETERIORATE SOLIDLY INTO A MIX OF AT LEAST MVFR AND IFR
CONDITIONS BETWEEN 06Z AND 18Z TUESDAY. THERE IS GOOD CHANCE LIFR
CONDITIONS WILL IMPACT MOST TERMINALS DURING THIS TIME.
KPDX AND APPROACHES...A SHOWERY UNSTABLE AIRMASS WILL LEAD TO
PRIMARILY VFR CONDITIONS WITH OCCASIONAL MVFR CONDITIONS BETWEEN
17Z AND 21Z MONDAY. A STABILIZING LOWER ATMOSPHERE SHOULD RESULT
IN MVFR/IFR FLIGHT RESTRICTIONS DEVELOPING TOWARDS 06Z TUESDAY AND
CONTINUING THROUGH 18Z TUESDAY. THERE APPEARS TO BE A GOOD CHANCE
LIFR CONDITIONS WILL DEVELOP DURING THIS PERIOD. /NEUMAN
&&
.MARINE...A WEAK LOW PRESSURE WILL MOVE SOUTHWARD NEAR THE COAST
TODAY...REINFORCING GUSTY NORTHWEST WINDS OF 20 TO 30 KT ACROSS
THE WATERS. THESE WINDS SHOULD GRADUALLY SUBSIDE THIS EVENING AS
PRESSURE GRADIENTS RELAX. WITH NO MAJOR STORM SYSTEMS IN THE
EASTERN PACIFIC...THE LARGE SEAS CURRENTLY FOUND IN THE WATERS
WILL ALSO SUBSIDE DURING THIS TIME...LIKELY FALLING INTO THE LOW
TEENS BY THIS EVENING AND BELOW 10 FT BY TUESDAY MORNING.
THE NEXT STORM SYSTEM...IN THE FORM OF A WARM FRONT...WILL SPREAD
INTO THE WATERS ON WEDNESDAY NIGHT...WHICH SHOULD RESULT IN HIGH
END SMALL CRAFT TO LOW END GALE FORCE WIND GUSTS OF 30 TO 35 KT
SPREADING INTO THE WATERS. A LOW PRESSURE MAY POSSIBLY DEVELOPING
ALONG THE TRAILING COLD FRONT...WHICH COULD RESULT IN HIGHER WINDS
AND SEAS TOWARDS THURSDAY...BUT CONFIDENCE IN DETAILS REMAINS LOW
GIVEN MODELS CONTINUE IN THEIR DEPICTION OF THIS STORM SYSTEM. A
WEAK FRONT OR TWO MAY MOVE INTO THE WATERS FRIDAY/SATURDAY TIME
FRAME...BEFORE ANOTHER STRONGER FRONTAL STORM SYSTEM POSSIBLY
MOVES INTO THE WATERS LATE SATURDAY/SUNDAY. /NEUMAN
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY UNTIL 11 AM PST THIS MORNING FOR COAST
RANGE OF NORTHWEST OREGON.
WINTER WEATHER ADVISORY UNTIL 1 PM PST THIS AFTERNOON FOR
CENTRAL COAST RANGE OF WESTERN OREGON.
WA...NONE.
PZ...SMALL CRAFT ADVISORY FOR WINDS UNTIL 10 PM PST THIS EVENING FOR
COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT 60 NM.
SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 5 AM PST TUESDAY
FOR COASTAL WATERS FROM CAPE SHOALWATER WA TO FLORENCE OR OUT
60 NM.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 9 AM
PST TUESDAY.
&&
$$
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/NWSPORTLAND
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON
FROM THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS
COMMONLY REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
253 PM CST MON DEC 14 2015
.SHORT TERM (TONIGHT THROUGH TUESDAY)...
FOCUS FOR THE SHORT TERM WILL CENTER AROUND A FRONTAL PASSAGE
TOMORROW INTO EARLY WEDNESDAY THAT WILL HELP GENERATE ISOLATED TO
SCATTERED (20-40% CHANCE) LIGHT RAIN SHOWERS FOR CENTRAL AND
MAINLY EASTERN LOCATIONS.
WATER VAPOR AND RAP ANALYSIS DEPICT AN EXITING SHORTWAVE TROUGH
OVER THE GREAT LAKES REGION AND AN INCOMING LONGWAVE TROUGH OVER
THE WESTERN BASIN. THIS WESTERN BASIN TROUGH IS NOT NEARLY AS
STRONG OR AS DEEP EQUATORWARD AS THE PREVIOUS SYSTEM BUT IT WILL
SEND A COLD FRONT THROUGH THE REGION LATE TUESDAY INTO WEDNESDAY
MORNING. FOR TODAY HOWEVER...DRIER AIR IS IN PLACE WITH A NICE
WARM UP OCCURRING. TEMPERATURES ARE IN THE LOW TO MID 70S AREAWIDE
WITH SOME LOCATIONS IN THE UPPER 70S ACROSS THE RIO GRANDE. EXPECT
ANOTHER 2-3F DEGREES FROM CURRENT READINGS WITH THE AMPLE SUN.
HAVE INCREASED MAX HIGHS FOR THIS AFTERNOON IN CONCERT WITH THESE
TRENDS.
OVERNIGHT AND INTO TUESDAY...MOISTURE IS SLATED TO RETURN BACK
INTO THE REGION FROM THE SOUTH BUT VALUES WILL BE SUBDUED.
CURRENT PWATS NEAR 0.3" WILL ONLY RECOVER TO 0.8" BY TUESDAY
AFTERNOON BEFORE THE FRONT ARRIVES. TUESDAY MORNING WILL BE WARMER
GIVEN A BLANKETING CLOUD COVER THAT WILL ALSO HELP GENERATE SOME
LIGHT PATCHY DRIZZLE. THIS LIGHT DRIZZLE AND LIGHT RAIN WILL
PERSIST INTO THE AFTERNOON ALONG AND AHEAD OF THE FRONT THAT MOVES
THROUGH LATE TUESDAY INTO WEDNESDAY MORNING. OVERALL RAINFALL
AMOUNTS ARE EXPECTED TO BE LIGHT WITH AT OR LESS THAN ONE QUARTER
OF AN INCH EXPECTED. CLOUDS LOOK TO HANG ON MOST OF THE DAY
TUESDAY SO LOWER HIGH TEMPERATURES ARE EXPECTED GIVEN NAM/GFS BUFR
SOUNDING OUTPUT.
&&
.LONG TERM (WEDNESDAY THROUGH MONDAY)...
A GENERALLY QUIET AND NEAR NORMAL TEMPERATURE REGIME WILL BE IN
STORE FOR THE REGION THROUGH THE END OF THE WEEK. CLOUDS WILL
RETURN OVER THE WEEKEND WITH A LOW-END RAIN CHANCE BY MONDAY WITH
THE PASSAGE OF ANOTHER DISTURBANCE IN THE CENTRAL PLAINS.
MID TO LATE WEEK WILL BE PLEASANT WITH SUNNY SKIES AND NEAR NORMAL
TEMPERATURES WITH LOWS IN THE LOWER TO MID 40S AND HIGHS IN THE
MID 60S. FRIDAY WILL BE SLIGHTLY COOLER AS RESIDUAL COOL AIR
ADVECTION CONTINUES JUST BEFORE WINDS TURN BACK OUT OF THE SOUTH.
PWATS WILL REMAIN QUITE LOW /0.15-0.3"/ THROUGH FRIDAY BEFORE
INCREASING TO 0.6-0.7" ON SATURDAY. SOUTH WINDS WILL AID THIS PWAT
INCREASE AS A H5 SHORTWAVE TROUGH AND ASSOCIATED SURFACE TROUGH
HELP GENERATE SOUTH FLOW OVER THE REGION. THE EC IS SLIGHTLY
DRIER AS IT DEPICTS ENERGY FARTHER NORTH VS. THE GFS. HAVE HELD
OFF ON INTRODUCING RAIN CHANCES FOR SATURDAY AND SUNDAY AT THIS
TIME BUT DID PLACE A LOW-END 20% FOR MONDAY WHERE BETTER MODEL
AGREEMENT OCCURS. AT THIS PARTICULAR STAGE...PWATS MAY REACH
UPWARDS OF 1.3-1.5" IN THE FAR EAST BEFORE THIS FRONT MOVES
THROUGH MONDAY AND THIS WOULD LIKELY SUPPORT SOME SHOWER ACTIVITY
DESPITE THE SIDESWIPE OF THE TROUGH ENERGY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 50 72 49 64 38 / 0 30 20 - -
AUSTIN BERGSTROM INTL AIRPORT 47 73 48 64 35 / 0 30 20 10 -
NEW BRAUNFELS MUNI AIRPORT 48 73 50 64 37 / 0 30 20 10 -
BURNET MUNI AIRPORT 49 68 43 60 35 / 0 20 10 - -
DEL RIO INTL AIRPORT 46 66 41 65 36 / 0 - 0 0 0
GEORGETOWN MUNI AIRPORT 50 71 45 61 35 / 0 30 10 - -
HONDO MUNI AIRPORT 48 71 48 66 35 / 0 20 10 - 0
SAN MARCOS MUNI AIRPORT 49 72 49 64 36 / 0 30 20 10 -
LA GRANGE - FAYETTE REGIONAL 51 77 54 64 39 / 0 30 40 10 -
SAN ANTONIO INTL AIRPORT 50 73 51 65 38 / 0 20 10 - -
STINSON MUNI AIRPORT 50 75 53 66 39 / 0 20 10 - -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...09
SYNOPTIC/GRIDS...ALLEN
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1248 PM EST MON DEC 14 2015
.SYNOPSIS...
A DEEP LOW PRESSURE AREA WILL MOVE RAPIDLY FROM THE SOUTHERN
PLAINS TOWARD THE GREAT LAKES TODAY...PUSHING A COLD FRONT THROUGH
THE MID-ATLANTIC. WEAK HIGH PRESSURE WILL BUILD ACROSS THE REGION
FOR TUESDAY AND WEDNESDAY. LOW PRESSURE WILL THEN DEVELOP ACROSS
THE SOUTHEAST U.S. THURSDAY...PULLING A STRONGER COLD FRONT
THROUGH OUR REGION FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 919 AM EST MONDAY...
MODIFIED TEMPERATURES WITH LATEST OBS AND RAISED HIGH TEMPERATURES
IN SEVERAL LOCATIONS...ESPECIALLY IN THE WEST. SHAPED POPS THIS
MORNING INTO THIS AFTERNOON TOWARDS A HRRR AND HIRESW-ARW BLEND.
WITH KFCX WSR-88D LOOP SHOWING LIGHT MOISTURE SPREADING NORTHEAST
ALONG THE BLUE RIDGE...EXPANDED LIGHT POPS FURTHER EAST THIS
MORNING INTO THIS AFTERNOON. THE 12Z RNK SOUNDING DID SHOWED A
SOUTHWEST 50 KNOT JET AROUND 800 MB WITH A PWAT AT 0.63 INCHES.
WILL HOLD WITH CURRENT WIND ADVISORY UNTIL 7 PM ACROSS HIGHER
TERRAIN WITH THE LOW LEVEL JET ROTATING NORTHEAST THIS MORNING
INTO THIS AFTERNOON. POSTED SPS FOR FOG AND LOW CLOUDS ALONG
INTERSTATE 77 FOR THIS MORNING. MORE CHANGES LATER THIS MORNING...
AS OF 415 AM EST MONDAY...
AWAITING THE LONG ADVERTISED COLD FRONT THIS PERIOD.
COMBINATION OF SYNOPTIC SCALE...GFS/ECMWF/NAM...AND SHORT RANGE
MESOSCALE MODELS...HRRR/RNK-WRF/NCEP-WRF...SHOW CONTINUED SLOWER
PROGRESSION AND WEAKENING OF THE CURRENTLY IMPRESSIVE SYSTEM
ACROSS THE WESTERN TENNESSEE VALLEY. JUST A FEW RUNS BACK OF THE
SYNOPTIC SCALE MODELS WOULD HAVE HAD THE ASSOCIATED LINE OF
CONVECTIVE SHOWERS IN OUR CWA AT 12Z THIS MORNING. INSTEAD...THIS
LINE IS SEVERAL HUNDRED MILES STILL WEST OF THE CWA. LATEST
PROJECTIONS DO NOT SHOW THIS LINE OF CONVECTION REACHING THE
WESTERN PARTS OF THE CWA UNTIL LATE MORNING...THEN SPREADING EAST
DURING THE AFTERNOON/EARLY EVENING. CONSIDERABLE WEAKENING IS ALSO
INDICATED AS THE ACTIVITY ATTEMPTS TO PUSH EAST OF THE BLUE RIDGE
AND THE PARENT UPPER LOW TRACKS NORTH-NORTHEAST TOWARD THE GREAT
LAKES. THIS HAS RESULTED IN SLOWER TIMING OF THE HIGHER POPS INTO
THE CWA AND REDUCED POPS ACROSS EASTERN AREAS.
MEANWHILE...A WARM ADVECTION WING HAS DEVELOPED ACROSS THE
SOUTHEAST PART OF THE CWA INTO CENTRAL NC/SC...AIDED BY
INCREASINGLY MOIST SOUTHERLY UPSLOPE FLOW ALONG THE BLUE RIDGE. AS
A RESULT...SCATTERED SPRINKLES/LIGHT RAIN SHOWERS/DRIZZLE EVIDENT
IN THESE AREAS. MESOSCALE MODELS SHOW THIS HOLDING STEADFAST AND
TRACKING NORTHEAST INTO THE SHENANDOAH VALLEY BY EARLY AFTERNOON
AS THE LINE OF SHOWERS APPROACHES FROM THE WEST. STILL WILL HAVE
CATEGORICAL TO LIKELY POPS ACROSS MOST OF THE CWA THROUGH THE DAY
FROM WEST-EAST AS FEEL MOST LOCATIONS WILL AT LEAST SEE 0.01 INCH.
WITH RESPECT TO THE WIND CONCERN...THE STRONGEST 850MB WINDS ARE
PROGGED TO REACH THE WESTERN BORDER AROUND 12Z...THEN TRANSLATE
NNE WITH THE PARENT UPPER LOW. WINDS DO NOT REALLY SHIFT
APPRECIABLY TO THE WEST/NORTHWEST UNTIL EVENING. CURRENT WIND
ADVISORY IN EFFECT FOR THE HIGHER TERRAIN UNTIL 00Z TUE. WILL
LEAVE AS IS...BUT MAIN CONCERN REMAINS THAT OF WINDS AHEAD OF THE
SHOWERS AND ASSOCIATED WITH THE MORNING LLJ...NOT WINDS BEHIND THE
SHOWERS/TROUGH. MOMENTUM TRANSFER INDICATED VIA BUFKIT IS
POOR...BUT AM OBSERVING WINDS GUSTS IN THE 35-45 MPH RANGE ACROSS
MERCER/TAZEWELL AND ALLEGHANY NC COUNTIES.
TEMPERATURES WILL REMAIN WELL ABOVE NORMAL THROUGH THE
PERIOD...BUT NOT AS WARM AS PREVIOUS DAYS THANKS TO CLOUDS AND
PRECIPITATION. STARTING OUT UNSEASONABLY MILD THIS MORNING WITH
MANY AREAS IN THE LOWER TO MIDDLE 60S. TUESDAY MORNING SHOULD BE A
TAD COOLER WITH CLEARING...SLIGHTLY DRIER AIR...HIGH
PRESSURE...AND LESS WIND...BUT NONETHELESS STILL WELL ABOVE NORMAL
WITH NO FREEZING TEMPERATURES INDICATED UNTIL LATE IN THE WEEK.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
AS OF 236 AM EST MONDAY...
AFTER A BREEZY MORNING TUESDAY...A WEAK AREA OF HIGH PRESSURE WILL
BUILD EAST UNDER SHORT WAVE RIDGING. DESPITE COOLER AIR WORKING INTO
THE REGION...TUESDAY`S AFTERNOON HIGHS WILL REMAIN WARMER THAN
NORMAL WITH UPPER 50S WEST AND MID TO UPPER 60S EAST. THIS AREA OF
HIGH PRESSURE WILL MOVE OVER THE MID ATLANTIC REGION...WEDGING SOUTH
INTO THE CAROLINAS TUESDAY NIGHT. LIGHT SOUTHEASTERLY LOW LEVEL FLOW
AND INCREASING CLOUDS COVER FROM THE SOUTH WILL PRODUCE UNIFORM
TEMPERATURES IN THE UPPER 50S TO LOWER 60S WEDNESDAY. A DISTURBANCE
WILL MOVE OUT OF THE GULF ON WEDNESDAY AND TRACK ALONG THE SOUTHERN
APPALACHIANS WEDNESDAY NIGHT INTO THURSDAY. THIS SYSTEM WILL BRING
ABOUT AN INCH OF RAIN TO AREAS ALONG AND EAST OF THE BLUE RIDGE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
AS OF 1230 PM EST SUNDAY...
THE LONG RANGE FEATURES THE FIRST BIG ARCTIC PUSH INTO THE REGION
FOR QUITE SOME TIME...ALTHOUGH THE COLD AIR WONT STICK AROUND LONG.
THE PERIOD STARTS WARM WITH +11C 850MB TEMPS AHEAD OF AN APPROACHING
COLD FRONT AND DIGGING TROUGH. EXPECT SHOWERS AHEAD OF THE FRONT
THURSDAY INTO FRIDAY. EXACTLY HOW MUCH RAIN WILL FALL ACROSS OUR
REGION WILL DEPEND ON HOW DEEP THE TROUGH TO OUR WEST DIGS...FOR
RIGHT NOW IT LOOKS LIKE AREAS ALONG AND EAST OF THE BLUE RIDGE WILL
SEE THE MOST RAIN. THE COLD FRONT WILL PUSH THROUGH THE AREA
SOMETIME FRIDAY MORNING PUSHING THE RAIN OUT WITH IT.
BEHIND THE COLD FRONT TEMPS WILL FALL QUICKLY. AS THE TROUGH SWINGS
THROUGH THE REGION 850MB TEMPS WILL DROP DOWN TO -10 TO -12C BY
SATURDAY MORNING. WITH SUFFICIENT LOW LEVEL MOISTURE...THERE IS A
GOOD CHANCE WE WILL SEE NORTHWEST FLOW SNOW SHOWERS ALONG THE
FAVORED WESTERN RIDGES FRIDAY NIGHT AND THROUGH THE DAY SATURDAY.
HIGH TEMPS SATURDAY WILL RUN 5-10 DEGREES BELOW NORMAL WITH MANY
MOUNTAIN LOCATIONS STRUGGLING TO REACH THE FREEZING MARK.
BY SUNDAY THE TROUGH MOVES OFF TO OUR EAST AND ALONG WITH IT THE
COLD AIR. STRONG HIGH PRESSURE BUILDS IN AND WILL MOVE JUST TO OUR
EAST SUNDAY NIGHT/MONDAY MORNING. THE W/SW FLOW WILL ONCE AGAIN PULL
WARM AIR INTO THE REGION AND WE RETURN TO ABOVE NORMAL TEMPS.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
AS OF 1249 PM EST MONDAY...
MVFR CONDITIONS WITH AREAS OF IFR AND LIFR IN LOW CLOUDS...RAIN
AND FOG WILL CONTINUE THIS AFTERNOON INTO TONIGHT. STRONG
GUSTY SOUTH TO SOUTHWEST WINDS WILL HINDER AVIATION OPERATIONS.
THE STRONGEST LLJ WILL MOVE ACROSS WESTERN PORTIONS OF THE CWA
THIS AFTERNOON...THEN LIFT NORTH TO NORTHEAST TONIGHT TOWARD
WESTERN PENNSYLVANIA. PATCHES OF LIGHT RAIN...DRIZZLE AND FOG
CONTINUE TO LIFT NORTH ACROSS FORECAST AREA THIS AFTERNOON
AHEAD OF THE MAIN BAND OF SHOWERS ASSOCIATED WITH THE FRONT.
WOULD EXPECT MVFR-IFR CIGS WITH SHOWERS...THEN IMPROVING TO VFR
AFT 00Z EAST OF THE BLUE RIDGE WITH INCREASING DOWNSLOPE
WINDS...BUT REMAINING MVFR TO THE WEST. VISIBILITIES SHOULD
GENERALLY REMAIN MVFR OR BETTER WITH MOST OF RAIN SHOWERS EXPECTED
TO BE LIGHT. WINDS BEHIND THE FRONT WILL BECOME WSW-W WITH SPEEDS
MOSTLY BETWEEN 8-10KTS AND LOW END GUSTS UP UNTIL ABOUT 04Z.
SOME MVFR CONDITIONS EXPECTED IN THE WESTERN UPSLOPE REGION OF
SOUTHEAST WEST VIRGINIA TUESDAY. VFR CONDITIONS EXPECTED
ACROSS REST OF TAF LOCATIONS.
MEDIUM CONFIDENCE IN CIGS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN VSBYS THROUGH THE TAF VALID PERIOD.
MEDIUM CONFIDENCE IN WIND SPD/DIR THROUGH THE TAF VALID PERIOD.
.EXTENDED AVIATION DISCUSSION...
WIDESPREAD VFR UNDER DIMINISHING WINDS WILL OCCUR UNDER WEAK HIGH
PRESSURE TUESDAY INTO WEDNESDAY. ANOTHER COLD FRONT WITH AN
ASSOCIATED AREA OF LOW PRESSURE LOOKS TO BRING MORE IN THE WAY OF
WIDESPREAD SUB- VFR IN RAIN AND LOWER CIGS LATE WEDNESDAY NIGHT
INTO THURSDAY EVENING. SHOULD EVOLVE INTO VFR DURING FRIDAY AS
DEEP MOISTURE EXITS AND AN UPSTREAM UPPER DISTURBANCE APPROACHES.
HOWEVER LINGERING UPSLOPE FLOW LIKELY TO KEEP MVFR CEILINGS IN
PLACE ACROSS THE SOUTHEAST WEST VA SITES FOR MUCH OF THE DAY.
&&
.CLIMATE...
AS OF 745 PM EST SUNDAY...
RECORD HIGH TEMPERATURES WERE SET TODAY (12/13) AT BOTH DANVILLE
VA AND BLUEFIELD WV. SEE THE LATEST WBCRERRNK FOR ADDED DETAILS.
RECORD HIGH TEMPERATURES FOR....
DEC 14
BLACKSBURG | 70 IN 1984 |
BLUEFIELD | 68 IN 1984 |
DANVILLE | 74 IN 1948 |
LYNCHBURG | 70 IN 1948 |
ROANOKE | 73 IN 1927 |
RECORD HIGH MINIMUM TEMPERATURES FOR....
BLACKSBURG | 49 IN 1991 |
BLUEFIELD | 53 IN 1984 |
DANVILLE | 53 IN 1991 |
LYNCHBURG | 55 IN 1901 |
ROANOKE | 60 IN 1927 |
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR VAZ007-009-010-
015.
NC...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR NCZ001-018.
WV...WIND ADVISORY UNTIL 7 PM EST THIS EVENING FOR WVZ042.
&&
$$
SYNOPSIS...RAB
NEAR TERM...KK/RAB
SHORT TERM...RCS
LONG TERM...CF
AVIATION...KK/RAB
CLIMATE...CF/JH/RAB/WP