Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/24/15
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
253 PM MST TUE DEC 22 2015
.SYNOPSIS...
PACIFIC MOISTURE WILL SPREAD ACROSS THE REGION THROUGH THE WEEK
RESULTING IN PERIODS OF CLOUDINESS AND CHANCES FOR
PRECIPITATION...MAINLY NORTH AND EAST OF PHOENIX. THE BEST CHANCES
FOR RAIN APPEAR TO BE TONIGHT INTO WEDNESDAY AND AGAIN THURSDAY INTO
CHRISTMAS. WHILE THESE SYSTEMS DO NOT LOOK VERY WET...THEY COULD MAKE
FOR DIFFICULT TRAVEL CONDITIONS ACROSS NORTHERN ARIZONA. TEMPERATURES
WILL REMAIN NEAR NORMAL BUT ARE EXPECTED TO DROP LATE IN THE WEEK AND
INTO THE WEEKEND AS A STRONG AND COLD LOW PRESSURE SYSTEM AFFECTS THE
DESERT SOUTHWEST. SOME GUSTY DAYTIME WINDS AND SUB FREEZING NIGHTTIME
TEMPERATURES WILL BE POSSIBLE OVER THE WEEKEND FOR THE LOWER DESERTS.
&&
.DISCUSSION...
LATEST VISIBLE SATELLITE SHOWS WIDESPREAD THICK STRATOCU AND
NUMEROUS AREAS OF MOUNTAIN WAVE CLOUDINESS ACROSS AZ. LATEST RADAR
CONTINUES TO SHOW BACKBUILDING LIGHT RAIN AND SPRINKLES ACROSS
NORTHERN MARICOPA COUNTY...INCLUDING PORTIONS OF THE PHOENIX AREA.
DESPITE THE PRESENCE OF A 100+ KT 250 MB JET...VORTICITY AND JET-
FORCED ASCENT REMAIN RELATIVELY WEAK. LIGHT PRECIPITATION APPEARS TO
BE MORE A RESULT OF THE SUFFICIENT MOISTURE TRANSPORT FROM THE
REMNANT ATMOSPHERIC RIVER COUPLED WITH ANOMALOUSLY STRONG MID-LEVEL
FLOW AND SUBSEQUENT OROGRAPHIC INFLUENCES. 500 MB WIND SPEEDS ARE NOT
EXACTLY OFF THE CHART...BUT CLOSE TO THE 90TH PERCENTILE PER THE SPC
SOUNDING CLIMATOLOGY AND NAEFS PERCENTILES.
THE THICK CLOUDINESS HAS INHIBITED INSOLATION AND TEMPERATURES HAVE
STRUGGLED TO GET THROUGH THE LOWER-MID 50S...STILL WELL ABOVE THE
RECORD LOW MAXIMUM OF 46 DEGREES IN PHOENIX. HI-RES WRFS ALONG WITH
THE NCAR ENSEMBLE AND LATEST RUNS OF THE HRRR INDICATE THAT THE
LIGHT PRECIP WILL GRADUALLY WORK EASTWARD INTO GILA COUNTY TONIGHT AND
EVENTUALLY SOUTHWARD TOWARDS PINAL COUNTY. ANY RAIN THAT DEVELOPS
WILL LIKELY ONLY AMOUNT TO A FEW HUNDREDTHS OF AN INCH AT MOST IN THE
LOWER DESERTS.
LATEST GFS AND ECMWF REMAIN IN GOOD AGREEMENT THE NEXT FEW
DAYS...INDICATING THAT THE MOIST NORTHWESTERLY FLOW WILL PERSIST.
TREND HAS BEEN A LITTLE BIT FURTHER TO THE EAST ACROSS THE HIGHER
TERRAIN OF MARICOPA AND GILA COUNTIES WITH REGARD TO THE BEST CHANCE
OF PRECIP. CONSEQUENTLY...FORECAST POPS HAVE BEEN REFINED TO DECREASE
VALUES FURTHER WEST AND INCREASE THEM ACROSS GILA COUNTY...IN LINE
WITH THE VALUES FROM THE LATEST GEFS REFORECAST CALIBRATED TO CLIMO.
LATEST MULTI-MODEL ENSEMBLE MEDIAN ALSO SUGGESTS THAT STORM TOTALS
ACROSS THE HIGHER TERRAIN OF GILA COUNTY COULD REACH A HALF OF AN
INCH THROUGH CHRISTMAS EVE. NO SIGNIFICANT CHANGES WERE MADE TO THE
TEMPERATURES...WHICH REMAIN AT OR BELOW NORMAL.
&&
.PREVIOUS DISCUSSION...
THE NEXT BETTER ORGANIZED SYSTEM WILL DEVELOP OUT OF THE GULF OF
ALASKA AND ARRIVE INTO OUR AREA LATE THURSDAY AND INTO FRIDAY. THIS
PARTICULAR SYSTEM WILL QUICKLY MOVE INTO THE AREA AND CUT-OFF FROM
THE MAIN STORM TRACK WHILE BRINGING A SIGNIFICANT COLD POOL AND
FORCING INTO THE REGION. TIGHT INTERSECTION OF FRONTOGENETICAL
FORCING AND MOISTURE BEFORE DRIER AIR BEGINS TO WRAP INTO THE AREA
FROM THE NORTH LIMITS PRECIPITATION AGAIN MAINLY ACROSS
NORTHERN/EASTERN AZ...EVEN LIMITING PRECIP CHANCES FOR THE PHX AREA
COME FRIDAY AND INTO SATURDAY. WITH THE SYSTEM LOOKING TO BE VERY
COLD...500 MB TEMPS AT -31C/700 MB TEMPS AT -14C AND 850 TEMPS AT -
2.5C ALL POSSIBLE UNDER THE STRONGER SCENARIOS...SNOW LEVELS WILL
DROP TO 3000 FEET OR POSSIBLY LOWER. THUS THE BIGGEST IMPACT WILL
LIKELY BE FOR TRAVELERS INTO OR ACROSS THE HIGHER ELEVATIONS AREAS OF
AZ. STRONG FUNNELING WINDS ALONG THE EASTERN FRINGE OF THE
SUBTROPICAL PACIFIC RIDGE AND THE DEPARTING CUT-OFF LOW WILL LEAD TO
WINDY CONDITIONS ALONG THE CO RIVER VALLEY FOR SATURDAY. LINGERING
INTO SUNDAY STRONG GUSTY WINDS FROM THE NORTH MAY CAUSE DIFFICULT
TRAVEL PERIODS FOR MOTORISTS ALONG EAST-WEST ORIENTED
ROADWAYS...INCLUDING INTERSTATE 8/10.
CLEARING SKIES...STRONG SURFACE HIGHS AND REINTRODUCTION OF THE
SIGNIFICANTLY COLDER AIRMASS WILL LEAD VERY COOL WEEKEND DAYTIME
TEMPERATURES AS WELL AS ANOTHER ROUND OF FREEZING OR SUB-FREEZING
TEMPERATURES FOR SOME OUTLYING LOWER ELEVATION DESERTS SATURDAY AND
SUNDAY MORNINGS. FOR THE EARLY NEXT WEEK...SOME DISCREPANCY REMAINS
BETWEEN THE DETERMINISTIC AND ENSEMBLE SUITES WITH THE TIMING OF
SHORTWAVE RIDGING AND ADDITIONAL LOW PRESSURE FEATURES PASSING
THROUGH THE REGION. AT THE MOMENT THOUGH WITH THE RE-ESTABLISHED DRY
AIRMASS AND LOSS OF ENHANCED MOISTURE FLOW FROM OFF THE NORTHEASTERN
PACIFIC THESE LOW PRESSURE WAVES APPEAR TO LACK MUCH BY WAY OF
PRECIP FOR THE FORECAST AREA AHEAD OF THE NEW YEAR`S HOLIDAY.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
MOIST NORTHWEST FLOW ALOFT CONTINUES...WITH CIGS SETTLING AOB 5000FT
FOR THE NEXT 24 HOURS OR SO. ISOLD TO SCT -SHRA POSSIBLE THROUGH THE
AFTERNOON/EVENING...WITH CIGS LOWERING TO NEAR 3000FT AFTER 07Z
WEDNESDAY MORNING. VISIBILITY LIKELY TO DETERIORATE AS THE EVENING
PROGRESSES...DROPPING TO NEAR 3SM IN HZ/BR BY 10Z...WITH POTENTIAL
FOR DZ TO TAKE VISIBILITY DOWN TO LESS THAN 1SM FOR PERIODS OF TIME
AT ANY TERMINAL...ESPECIALLY AT KSDL. WINDS EXPECTED TO BE LIGHT AND
FAVOR THE EAST-SOUTHEAST FOR THE NEXT 24 HOURS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CIGS AROUND 8000FT EXPECTED TO PERSIST THROUGH MID-DAY...WITH CIGS
IMPROVING AND CLOUD DECKS SCATTERING OUT THIS AFTERNOON/EVENING.
EXPECT GUSTY WEST-SOUTHWEST WINDS TO NEAR 30KT AT KIPL/KBLH UNTIL
AROUND 03Z THIS EVENING...WINDS DIMINISHING LATER BUT GENERALLY 15KT
OR LESS OVERNIGHT INTO WEDNESDAY MORNING.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
THURSDAY THROUGH MONDAY...
A LOW PRESSURE SYSTEM WILL AFFECT THE DISTRICTS INTO THE WEEKEND...
BRINGING WIDELY SCATTERED DESERT RAIN AND MOUNTAIN SNOW SHOWERS FROM
MARICOPA COUNTY EASTWARD...WITH SOUTHWEST ARIZONA AND SOUTHEAST
CALIFORNIA DESERTS REMAINING DRY. AS THE LOW MOVES THROUGH THE
REGION...WINDS WILL INCREASE OUT OF THE NORTH-NORTHWEST WITH GUSTS
UP TO 40 MPH POSSIBLE ACROSS SOUTHEAST CALIFORNIA AND ALONG THE
LOWER COLORADO RIVER VALLEY SATURDAY. MUCH LESS WIND ALONG WITH
DRIER CONDITIONS ARE EXPECTED AREA-WIDE SUNDAY AS THE UPPER LOW
SHIFTS OFF TOWARDS THE EAST. MUCH DRIER AIR WILL SPREAD INTO THE
AREA BEHIND THE DEPARTING LOW...WITH MINIMUM HUMIDITY VALUES
DROPPING BACK INTO THE TEENS OVER MUCH OF SOUTHEAST CALIFORNIA AND
THE SOUTHWEST ARIZONA DESERTS INTO EARLY NEXT WEEK.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
PREVIOUS DISCUSSION...NOLTE
AVIATION...MEYERS
FIRE WEATHER...CB/MEYERS
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
922 AM EST TUE DEC 22 2015
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE WEST BUT DISSIPATE BEFORE
REACHING THE MID ATLANTIC TODAY. A WARM FRONT WILL DEVELOP TO THE
SOUTH OF THE REGION TODAY, LIFTING NORTHWARD THROUGH THE AREA LATE
WEDNESDAY. A COLD FRONT WILL CROSS THE REGION THURSDAY NIGHT. HIGH
PRESSURE BRIEFLY RETURNS FOR CHRISTMAS DAY. A WARM FRONT WILL LIFT
NORTHWARD THROUGH THE REGION OVER THE WEEKEND, FOLLOWED BY A COLD
FRONT EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
A SWLY LOW-LEVEL JET AHEAD OF THE SHORTWAVE TROUGH IS RESPONSIBLE
FOR A BAND OF OVERRUNNING PRECIP THAT STRETCHES FROM THE GULF COAST
TO CENTRAL PA. EXPECT SHOWERS TO BE LIGHT AND SCATTERED FROM I-95
WEST BEFORE 5 AM. THE STEADY RAIN WILL THEN OVERSPREAD THE AREA FROM
WEST TO EAST BETWEEN ABOUT 5 AM AND 9 AM. GUIDANCE, INCLUDING THE
HRRR, CONTINUE TO SHOW THE STEADIEST RAIN MOVING THRU NE PA AND ALSO
THE COASTAL PLAIN.
THE STEADY RAIN IS EXPECTED TO TAPER OFF FROM SW TO NE BETWEEN ABOUT
NOON AND 3 PM. ANY LINGERING SHOWERS OVER NJ/NE PA ARE EXPECTED TO
EXIT BEFORE SUNSET. BREAKS IN THE CLOUDS ARE ALSO EXPECTED TO
DEVELOP LATE IN THE DAY.
UNDERCUT MAV/MET GUIDANCE BY A DEGREE OR TWO FOR THIS AFTERNOON DUE
TO THE RAIN AND CLOUD COVER. ANY CLEARING LOOKS TO OCCUR AFTER PEAK
HEATING HOURS. IT`LL STILL BE VERY WARM FOR LATE DECEMBER STANDARDS
WITH HIGHS IN THE MU50S IN NE PA/NW NJ AND LM60S ELSEWHERE.
LATEST RADAR IMAGERY SHOWED MOST OF THE PRECIP IN NJ AND DE ATTM.
W OF THE DE RIVER IT HAS ALL BUT ENDED. THERE CUD BE SOME
ADDITIONAL DEVELOPMENT ACCORDING TO THE HRRR IN ALG AND SE OF THE
I-95 CORRIDOR LATER THIS MRNG/ELY THIS AFTN, BUT PRECIP SHUD END
LATER THIS AFTN. HOWEVER, FOR THE NEXT FEW HOURS, AT LEAST, MOST
OF NRN AND WRN AREAS SHOULD BE RELATIVELY RAIN FREE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM WEDNESDAY/...
THE PRESSURE GRADIENT IS FORECAST TO WEAKEN OVER THE AREA THIS
EVENING. THIS WILL ALLOW THE WINDS TO BECOME LIGHT AFTER SUNSET.
WITH A WET GROUND, BREAKS IN THE CLOUDS LIKELY TO DEVELOP AND THE
LIGHT WINDS THIS EVENING, THE AREA WILL BE PRIMED FOR RADIATIONAL
FOG TO DEVELOP. THERE IS A POTENTIAL FOR DENSE FOG IF SKIES CAN
CLEAR OUT FOR MOST OF THE EVENING. WILL MENTION THE CONDITIONAL
THREAT IN THE HWO. HOWEVER, DID NOT ADD THE DENSE QUALIFIER IN THE
WX GRIDS ATTM DUE TO SOME UNCERTAINTY IN HOW THE SETUP EVOLVES.
MIN TEMPS ARE IN LOW/MID 50S IN THE URBAN AND COASTAL LOCALES; 40S
IN THE RURAL AREAS.
HIGHER CLOUDS ARE EXPECTED TO MOVE BACK INTO THE AREA LATE TONIGHT
AS THE NEXT MID-LEVEL SHORTWAVE TROUGH AND WARM FRONT APPROACH FROM
THE SOUTH. SHOWERS MAY START TO OVERSPREAD THE DELMARVA AND FAR SRN
NJ ZONES EARLY IN THE MORNING.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
WEDNESDAY...A WARM FRONT DEVELOPING TO OUR SOUTH WILL GRADUALLY PUSH
NORTHWARD THROUGH THE DAY, PUSHING THROUGH OUR ARE WEDNESDAY NIGHT.
WITH A STRONG SOUTH/SOUTHWEST FLOW ALOFT, WE WILL CONTINUE TO HAVE
AN INCREDIBLE AMOUNT OF WARM, MOIST AIR RUSHING INTO OUR AREA. RAIN
WILL PUSH INTO THE REGION DURING THE MORNING AND THEN CONTINUE
THROUGH THE DAY. TEMPERATURES WILL RESPOND IN KIND AND ARE EXPECTED
TO SOAR INTO THE 60S THROUGH MUCH OF THE AREA. AREAS ACROSS THE
SOUTH MAY SEE TEMPERATURES RISE INTO THE LOWER 70S. AREAS ACROSS THE
NORTH MAY TAKE LONGER TO WARM DUE TO THE INCREASED DISTANCE FROM THE
WARM FRONT BUT ARE EXPECTED TO REACH INTO THE UPPER 50S TO LOWER
60S.
THURSDAY...THE WARM FRONT PUSHES NORTH OF THE AREA EARLY. STRONG
WARM AIR ADVECTION WILL CONTINUE ON THURSDAY AND UNSEASONABLY WARM
TEMPERATURES WILL RISE TO RECORD BREAKING LEVELS. HIGHS INTO THE 70S
ARE EXPECTED. A COLD FRONT, MORE LIKE A COOL FRONT, WILL CROSS THE
AREA THURSDAY NIGHT. THERE ARE EXPECTED TO BE BREAKS IN THE
PRECIPITATION COVERAGE THROUGH THE DAY ON THURSDAY BUT OVERALL EXPECT
SHOWERS TO END FROM NORTHWEST TO SOUTHEAST LATE THURSDAY. MODEL
SOUNDINGS DO SHOW SOME ELEVATED INSTABILITY WHICH MEANS THERE COULD
BE SOME ISOLATED RUMBLES OF THUNDER AROUND THE AREA. HOWEVER,
CONFIDENCE IS TOO LOW TO INCLUDE THUNDER IN THE FORECAST AT THIS
TIME.
FRIDAY/CHRISTMAS DAY...THIS MAY BE THE NICEST DAY OF THE EXTENDED
PERIOD AS WE SEE HIGH PRESSURE BRIEFLY BUILD INTO THE AREA. COOLER
THAN FRIDAY BUT WITH NO STRONG COLD AIR ADVECTION TAKING PLACE
BEHIND THE DEPARTING COLD FRONT, WE DON`T EXPECT TEMPERATURES TO
COOL OFF THAT MUCH. IT WILL CERTAINLY FEEL COLDER THAN THURSDAY AS
HIGHS WILL BE AROUND 10 TO 15 DEGREES COOLER ACROSS THE REGION.
HOWEVER, IT WILL STILL BE UNSEASONABLY WARM WITH HIGHS INTO THE 60S
THROUGH MUCH OF THE FORECAST AREA.
SATURDAY THROUGH MONDAY...ANOTHER WARM FRONT DEVELOPS TO OUR SOUTH
AND ONCE AGAIN THIS FRONT WILL TRACK NORTHWARD AND INTO OUR AREA. A
COLD FRONT WILL THEN CROSS THE REGION FROM THE WEST EARLY IN THE
WEEK. THERE ARE CONSIDERABLE TIMING DIFFERENCES IN THE MODELS AS TO
WHEN EITHER OF THE FRONTS ARRIVE AND THIS WILL DIRECTLY IMPACT HOW
MUCH PRECIPITATION WE MIGHT SEE ACROSS OUR REGION INTO EARLY NEXT
WEEK. WITH TOO MUCH UNCERTAINTY, HAVE NOT MADE MANY CHANGES TO THE
CURRENT FORECAST.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
EXCEPT FOR KABE AND KRDG, TAF SITES REMAIN VFR FOR CIGS, AND MVFR
FOR VSBYS. RAIN HAS ENDED ACRS MOST OF PA. HAVE MADE MORE
OPTIMISTIC TAFS FOR THE NEXT FEW HOURS FOR I-95 TAF SITES AND
POINTS E.
STILL SOME UNCERTAINTY AS TO WHAT HAPPENS LATER THIS AFTN. THERE
ARE IFR CIGS S AND W, SO WILL THOSE MOVE INTO THE REGION OR NOT.
ALL GUID STILL INDICATES YES, AND WHAT IS HAPPENING AT RDG AND ABE
WOULD SUGGEST YES. HOWEVER, THE GUID OVERPLAYED ITS HAND THIS
MRNG, SO CONFIDENCE IS LOW.
THE RAIN WILL QUICKLY END FROM SW TO NE DURING THE EARLY
AFTERNOON BUT IFR OR LOW MVFR CIGS MAY LINGER LATER INTO THE
AFTERNOON. THERE IS STILL A MODERATE AMOUNT OF UNCERTAINTY
REGARDING HOW QUICKLY THE TAF SITES WILL IMPROVE TO MVFR AND THEN
VFR. WENT WITH A CONSENSUS BETWEEN THE LAMP AND NAM MOS GUIDANCE
FOR THE 06Z TAFS, CALLING FOR THE LOW CLOUDS TO SCATTER OUT
BETWEEN 21Z AND 00Z.
A S-SWLY WIND MAINLY AOB 10 KT THIS MORNING. SHORTLY AFTER RAIN ENDS
THIS AFTERNOON, MIXING WILL DEEPEN, WINDS WILL VEER SLIGHTLY FROM
THE W-SW AND GUSTS TO 20 KT ARE POSSIBLE.
VFR TO START THE EVENING. GOOD SETUP FOR FOG TONIGHT ASSUMING
CLEARING OCCURS AS ADVERTISED BY GUIDANCE. EXPECT THE FOG TO DEVELOP
BEFORE MIDNIGHT AT THE MORE RURAL TERMINALS WITH A WET GROUND IN
PLACE. IFR/LIFR POSSIBLE OVERNIGHT. HIGHER CLOUD COVER AND LIGHT
RAIN MAY START TO OVERSPREAD ILG-MIV-ACY BEFORE 12Z WED. EVEN IF THE
FOG DISSIPATES AND VSBYS IMPROVE, CIGS SHOULD REMAIN LOW
(IFR/VLIFR).
OUTLOOK...
WEDNESDAY...MVFR/IFR CONDITIONS EXPECTED WITH RAIN OVERSPREADING THE
REGION. SOUTHEAST WINDS BECOME MORE SOUTHERLY THROUGH THE DAY. WINDS
AROUND 15 TO 20 KNOTS THROUGH THE AFTERNOON.
WEDNESDAY NIGHT...IFR CONDITIONS EXPECTED TO IMPROVE TO MVFR ACROSS
THE TERMINALS AS A WARM FRONT LIFTS NORTH OF THE REGION AND RAIN
BEGINS TO RAPER OFF. STRONG SOUTHWESTERLY WINDS UP TO 20 KNOTS.
THURSDAY...MVFR CONDITIONS EXPECTED TO CONTINUE. POSSIBLE
IMPROVEMENT TO VFR DURING THE AFTERNOON IN ADVANCE OF A COLD
FRONT. RAIN RETURNS THURSDAY AFTERNOON. SOUTHWEST WINDS 10 TO 15
KNOTS WITH HIGHER GUSTS POSSIBLE.
THURSDAY NIGHT...MVFR CONDITIONS EXPECTED IN RAIN WITH IMPROVEMENT
TO VFR BEHIND A COLD FRONTAL PASSAGE. GUSTY SOUTHWEST WINDS WILL
BECOME WEST BEHIND THE FRONT.
FRIDAY AND FRIDAY NIGHT...VFR CONDITIONS EXPECTED WITH WEST WINDS
AROUND 5 TO 10 KNOTS. A CHANCE FOR SOME RAIN LATE WITH MVFR
CONDITIONS POSSIBLE.
SATURDAY....MVFR CONDITION EXPECTED IN RAIN AS A WARM FRONT
MOVES INTO THE AREA.
&&
.MARINE...
SW WINDS 10-15 KT AND SEAS 3-5 FT IN OUR ATLANTIC WATERS (1-2 FT
IN THE DE BAY) THIS MORNING. WINDS ARE EXPECTED TO INCREASE TO
15-20 KT THIS AFTN BUT THERE IS NOT MUCH POTENTIAL FOR STRONGER
GUSTS IN THIS STABLE SETUP (WARM AIR ATOP THE COOLER WATERS).
CANNOT RULE OUT ISOLATED 25 KT GUSTS THIS AFTERNOON AT OUR
OFFSHORE BUOYS. A SCA WAS ISSUED FOR THIS AFTERNOON AND EVENING
FOR OUR ATLANTIC COASTAL ZONES WITH SEAS EXPECTED TO BUILD TO
AROUND 5 FT. NO HEADLINES FOR THE DE BAY.
WINDS BECOME LIGHT TONIGHT. SEAS SHOULD SUBSIDE LATE THIS EVENING
AND OVERNIGHT.
OUTLOOK...
WEDNESDAY AND THURSDAY...SMALL CRAFT ADVISORY CONDITIONS EXPECTED.
INCREASING STRONG SOUTHERLY FLOW WILL BUILD SEAS TO 5 TO 7 FEET.
STRONG SOUTHERLY WINDS AROUND 20 TO 30 KNOTS EXPECTED.
THURSDAY NIGHT THROUGH FRIDAY MORNING...WINDS WILL DROP OFF FAIRLY
QUICK BEHIND A COLD FRONTAL PASSAGE THURSDAY NIGHT. SEAS WILL TAKE A
LITTLE BIT LONGER TO SUBSIDE AND THE SMALL CRAFT ADVISORY MAY BE
NEEDED THROUGH FRIDAY MORNING.
FRIDAY MORNING THROUGH SATURDAY...SUB-ADVISORY CONDITIONS EXPECTED.
WEST WINDS WILL BECOME NORTH OVERNIGHT AND THEN NORTHEAST ON
SATURDAY. SEAS AROUND 2 TO 4 FEET.
&&
.CLIMATE...
DAILY RECORD HIGHS ARE POSSIBLE THIS WEDNESDAY, DECEMBER 23. THE
CALENDAR DAY HIGHS ON WEDNESDAY MAY OCCUR CLOSE TO MIDNIGHT WHEN
TEMPERATURES ARE EXPECTED TO RISE AFTER A WARM FRONT MOVES
THROUGH. THERE IS STILL UNCERTAINTY WITH THE TIMING OF THE WARM
FRONT BUT THE EARLIER THE WARM FRONT MAKES IT HERE, THE MORE
LIKELY THESE DAILY RECORDS WILL BE BROKEN.
DAILY RECORD HIGHS ARE EXPECTED THURSDAY, DECEMBER 24TH. CURRENTLY,
RECORD HIGHS ARE FORECAST FOR ALL 8 CLIMATE SITES.
THE FOLLOWING TABLE LISTS THE DAILY RECORD HIGHS FOR DECEMBER 23 AND
24TH THAT ARE IN JEOPARDY AT OUR EIGHT CLIMATE SITES.
DECEMBER 23 DECEMBER 24
SITE RECORD HIGH YEAR(S) SET RECORD HIGH YEAR(S) SET
----------- ----------- ----------- -----------
ACY 65 1990 65 1982
PHL 66 1990 64 1990, 2014
ILG 66 1990 65 2014
ABE 64 1990 62 1990
TTN 70 1891 63 1990, 2014
GED 68 1949, 2013 69 2014
RDG 63 1990, 2007 63 1990
MPO 58 1990 62 1990
WE MAY APPROACH ALL-TIME MONTHLY RECORD HIGHS (I.E., THE WARMEST DAY
IN DECEMBER) AS WELL. CURRENT FORECAST HIGHS ON THE 24TH ARE WITHIN
1-3 DEGREES OF THESE MONTHLY RECORDS AT SEVERAL LOCATIONS.
MONTHLY RECORD
SITE HIGHS FOR DECEMBER DATE(S) SET
------------------ -----------
PHL 73 12/4/1998, 12/7/1998
ACY 77 12/7/1998
ILG 75 12/4/1998
ABE 72 12/29/1984, 12/4/1998, 12/1/2006
TTN 76 12/7/1998
GED 77 12/1/1991
RDG 77 12/29/1984
MPO 67 12/13/2015
DECEMBER 2015 IS ON PACE TO SET THE ALL-TIME MONTHLY RECORD FOR
THE WARMEST DECEMBER AT PHILADELPHIA. THE AVERAGE TEMPERATURE FROM
DECEMBER 1-21ST AT PHL AIRPORT WAS 49.4F (10.6F ABOVE NORMAL)
WHICH IS THE WARMEST ON RECORD THROUGH THE FIRST 21 DAYS OF THE
MONTH. THE PREVIOUS WARMEST WAS 48.6F IN 2001.
MEAN TEMPERATURES THE LAST 10 DAYS OF THE MONTH (DECEMBER 22-31)
WOULD HAVE TO AVERAGE 34.5F (OR 0.2F BELOW NORMAL) TO TIE DECEMBER
1923 FOR THE WARMEST DECEMBER ON RECORD AT PHILADELPHIA (44.6F).
BASED ON OUR CURRENT FORECAST, WHICH HAS AN AVERAGE TEMPERATURE OF
57F (20-25F ABOVE NORMAL) FROM DECEMBER 22-28 AND CPC`S 6-10 DAY
OUTLOOK OF CONTINUED ABOVE NORMAL TEMPS, WE`LL SMASH THE PREVIOUS
RECORD BY MORE THAN 5F!
TO TRY TO PUT THE ABOVE INTO PERSPECTIVE...
THERE IS ONLY ONE OTHER OCCURRENCE IN THE PHILADELPHIA RECORD
BOOKS WHERE THE WARMEST MONTHLY MEAN TEMPERATURE WAS MORE THAN ONE
DEGREE HIGHER THAN THE SECOND WARMEST... THE MONTHLY MEAN
TEMPERATURE OF 46.2F IN JANUARY 1932 IS 2.9F ABOVE THE SECOND
WARMEST JANUARY ON RECORD (1950). BASED ON THE WHAT`S HAPPENED SO
FAR THIS MONTH AND OUR 7-DAY FORECAST, THE MEAN MONTHLY
TEMPERATURE PROJECTED THRU THE 28TH WOULD BE 51.2F. COMPARED TO
OTHER MONTHS (AND ASSUMING THE MONTHLY MEAN DOESN`T CHANGE
SIGNIFICANTLY OVER THE LAST THREE DAYS OF THE MONTH), THIS WOULD
RANK DECEMBER 2015 IN THE TOP THREE WARMEST MARCHES ON RECORD, IN
THE TOP 8 WARMEST NOVEMBERS ON RECORD AND ONLY A FEW DEGREES BELOW
THE MONTHLY NORMAL TEMPERATURE FOR APRIL!
OFFICIAL MONTHLY TEMPERATURE RECORDS FOR PHILADELPHIA DATE BACK TO
1872.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ450>455.
&&
$$
SYNOPSIS...MEOLA
NEAR TERM...KLEIN/NIERENBERG
SHORT TERM...KLEIN
LONG TERM...MEOLA
AVIATION...KLEIN/NIERENBERG/MEOLA
MARINE...KLEIN/MEOLA
CLIMATE...
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
816 PM EST WED DEC 23 2015
.Near Term [Through Tonight]...
For the remainder of tonight, the main focus will be on southeast
Alabama and adjacent sections of the Florida panhandle and
southwest Georgia as bands of showers and a few thunderstorms
continue to stream off to the northeast. The airmass is very moist
for this time of year with 70 degree dewpoints as far north as
Troy, AL. Rainfall rates with the embedded convection are
impressive with EOX dual-pol estimating instantaneous rates of up
to 2-4"/hr, but so far the bands have not been concentrated
enough over any one location to produce any flash flooding. Having
said that, there has been some minor flooding reported across
Houston county with a few rural roads being closed.
Some of our local hi-res guidance later tonight into Thursday
morning is a bit concerning showing these bands persisting and
intensifying through the night. Some of the recent HRRR runs also
hint at this possibility. Should that occur, the threat for
flooding would increase as this would occur over already saturated
soils, but confidence in the evolution of this convection is not
overly high. We`ll be watching for that possibility through the
night.
&&
.Prev Discussion [638 PM EST]...
.Short Term [Thursday Through Friday Night]...
The messy deep layer south/southwesterly flow will continue
through the short term. We`ll likely remain cloudy with a chance
for showers and an isolated storm each day. Though with little to
no surface focus, at this time the threat for any meaningful
rainfall totals will remain west of the Tri-State region. Severe
weather is also not expected during the period. The most notable
item through Friday will be the near record breaking high
temperatures. The local area has a good chance of breaking daily
record max temps on Christmas, and possibly breaking the all time
December high temperature record. Overnight lows will also remain
unseasonably warm, in the middle 60s.
.Long Term [Saturday Through Wednesday]...
The aforementioned warm pattern, with scattered rain chances will
continue through the weekend. Early next week, models indicate
that a large low pressure system will roll through the Mississippi
Valley and force a cold front into the region. It remains unclear
whether the front will make a clean passage, or get held up and
bring an increased chance of rain through mid week.
.Aviation...
[Through 00Z Thursday]...
Rain showers will continue this evening into tonight for all
terminals except for VLD. LIFR CIGs are likely tonight. IFR vis is
expected at most terminals with fog developing late tonight. By
mid-morning, conditions will improve to MVFR and rain will come to
an end. Winds will be southerly with gusts around 20 knots
possible on Thursday.
.Marine...
Southeast winds around 20 knots over the western waters this
evening will lower to cautionary levels after midnight. Winds and
seas over the western waters will approach 20 knots again this
weekend.
.Fire Weather...
Rainy conditions today and again this weekend will prevent
relative humidity values from dropping to critical levels. No red
flag conditions will occur for the next week.
.Hydrology...
This is the last round of heavy rain and scattered thunderstorms
for the region through the holiday weekend. Precipitation this
afternoon and overnight will diminish tomorrow morning and end by
midday. Areas of heaviest rain for the remainder of the afternoon
and overnight will continue to train across southeast AL...far
southwest GA... and the FL panhandle west of the Apalachicola
River. The Flash Flood Watch for those areas will continue
overnight. In general rainfall amounts of 1.5 to 4 inches have
fallen in this area through midday today with an additional 1 to 3
inches possible through daybreak tomorrow. Locally higher amounts
may occur overnight as we could see rainfall rates of 3 to 4
inches per hour in some thunderstorms.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 70 79 65 81 64 / 30 20 20 10 10
Panama City 72 77 67 77 65 / 30 30 20 10 10
Dothan 70 78 66 80 64 / 80 40 30 10 10
Albany 67 79 66 82 63 / 60 20 20 10 10
Valdosta 71 81 65 83 65 / 20 10 10 10 10
Cross City 70 83 64 84 64 / 20 10 10 10 10
Apalachicola 71 75 67 76 66 / 30 10 10 10 10
&&
.TAE WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AL...NONE.
GM...Small Craft Advisory until 1 AM EST Thursday FOR Coastal waters
from Apalachicola to Destin FL out 20 NM-Waters from
Apalachicola to Destin FL from 20 to 60 NM.
&&
$$
NEAR TERM...DVD
SHORT TERM...HARRIGAN
LONG TERM...HARRIGAN
AVIATION...MCDERMOTT
MARINE...MOORE
FIRE WEATHER...MOORE
HYDROLOGY...HOLLINGSWORTH
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
240 PM EST TUE DEC 22 2015
.DISCUSSION...
...MUCH ABOVE NORMAL TEMPERATURES THE REST OF THE WEEK...
...MODERATE TO HIGH RISK OF RIP CURRENTS THRU THE UPCOMING HOLIDAY
WEEKEND...
TONIGHT-WED...LARGE HIGH PRESSURE RIDGE EXTENDING FROM NEAR
BERMUDA TO CENTRAL FLORIDA WILL RULE IN THE LOWER LEVELS. THIS
WILL CONTINUE THE WARM AND MOIST SOUTHEAST/SOUTH WIND FLOW WITH
ELEVATED PRECIPITABLE WATER VALUES.
CONVECTION SO FAR THIS AFTERNOON HAS BEEN IN THE FORM OF SMALL
ISOLATED SHOWERS. RECENT HRRR MODEL RUNS HAVE BACKED OFF
DEVELOPMENT OF SCATTERED SHOWERS AND ISOLATED STORMS THAT IT HAD
BEEN SHOWING EARLIER. STILL THERE ARE SOME CLOUD BOUNDARIES NOTED
ON SATELLITE...SO WE WILL KEEP A SMALL CHANCE FOR SHOWERS IN THE
FORECAST THROUGH EVENING.
THE MAV GUIDANCE AGAIN SHOWS CONSIDERABLE LATE NIGHT STRATUS
DEVELOPING...BUT NOT QUITE AS MUCH FOG AS IT DID LAST NIGHT (WHEN
THERE WAS JUST A PATCH OR TWO OF GROUND FOG). THERE WILL AGAIN BE
CONSIDERABLE CLOUDINESS THROUGH THE NIGHT WITH BOUNDARY LAYER
WINDS AROUND 15 KNOTS...SO WILL NOT FORECAST ANY SIGNIFICANT FOG.
ON WED...MOS POPS ARE VERY LOW BUT IT WILL STAY VERY WARM AND
MOIST. THERE WILL BE CONSIDERABLE HIGH CLOUDINESS AGAIN BUT A FEW
RECORD HIGHS ARE STILL POSSIBLE. FORECAST SOUNDINGS DO NOT SHOW
ANY SIGNIFICANT CAPPING SO WILL KEEP A SMALL CHANCE FOR SHOWERS.
WED NIGHT/THU/THU NIGHT...A SHORTWAVE TROUGH WILL LIFT INTO THE
UPPER MS VALLEY WITH DEEPER MOISTURE ACROSS N FL AND THE SOUTHEAST
WED NIGHT. THE ATLC RIDGE WILL BUILD AT H5 FROM THE EAST TWD FL WITH
LOW LVL SSE KEEPING OVERNIGHT LOWS WARM IN THE UPPER 60S TO LOWER
70S. SSE LOW LVL WINDS EXPECTED ON THU WITH WARM TEMPS AGAIN NEAR
RECORD LEVELS ON CHRISTMAS EVE INTO THE LOWER 80S ALONG THE BEACHES
AND MID 80S INLAND. PWATS FROM 1.3 TO 1.5 INCHES ARE FORECAST WITH
DRYING FORECAST THROUGH THE DAY IN THE H8-H3 LAYER SO WILL CONTINUE
THE DRY AND VERY WARM FORECAST. LOW LVL FLOW WILL VEER SOME TO THE
SE THU NIGHT AND MAY ALLOW A LATE NIGHT SHOWER TO APPROACH THE COAST
FROM THE CAPE TO MARTIN COUNTY. OTHERWISE ANOTHER WARM NIGHT IS
EXPECTED WITH LOWS IN THE UPPER 60S FOR THE INTERIOR AND LOWER 70S
ALONG THE EAST COAST.
MODIFIED EXTENDED DISCUSSION...FRI-TUE...WHILE OVERALL DEEP LAYER
RIDGING MAY WEAKEN AND SHIFT SLOWLY WESTWARD THROUGH THIS TIME IT
STILL REMAINS A PERMANENT FIXTURE FOR OUR WEATHER WITH CONTINUED
SERLY FLOW OCNLY BREEZY ALONG THE COAST DURING THE DAY. THE SURFACE
RIDGING WILL LIFT SLOWLY NORTHWARD THRU THE WEEKEND. PRECIPITATION
CHANCES GENERALLY 20 PERCENT OR LESS AREAWIDE THROUGH THE EXTENDED
PERIOD. A WARMER THAN NORMAL PATTERN CONTINUES INTO MONDAY AND
TUESDAY NEXT WEEK WITH ADDITIONAL RECORD HIGHS AND WARM MINIMUM
TEMPERATURES LIKELY AS HIGHS REACH THE LOWER TO MID 80S AND LOWS
FORECAST IN THE UPPER 60S TO LOWER 70S.
&&
.AVIATION...
MAINLY VFR CONDITIONS THROUGH EVENING THOUGH LOCAL MVFR IS
POSSIBLE WITH ISOLATED SHOWERS. MAV GUIDANCE HAS SOME IFR
TO LIFR STRATUS FOR THE INTERIOR TERMINALS LATE TONIGHT WITH EVEN
DENSE FOG AT KLEE. THE GUIDANCE DID THAT FOR LAST NIGHTS FORECAST
TOO AND THERE WAS VERY LITTLE STRATUS/FOG. BOUNDARY LAYER WINDS
ARE FORECAST TO BE ABOUT THE SAME OVERNIGHT...NEAR 15 KNOTS AND
ALSO EXPECT CONSIDERABLE CLOUDINESS TO LINGER. HENCE...DID NOT HIT
THE STRATUS OR FOG HARD WITH THE PREVIOUS SET OF TAFS. WED WILL BE
ANOTHER QUITE WARM AND HUMID DAY WITH LOCAL MVFR CEILINGS AND
SMALL SHOWER CHANCES.
&&
.MARINE...
TONIGHT-WED...THE LATEST GFS SHOWS SLIGHT BAGGINESS IN THE
PRESSURE GRADIENT DISSIPATING THIS EVENING AND THEN SLIGHT
TIGHTENING INTO WED AFTERNOON. SOUTHEAST/SOUTH FLOW 15-20 IS
INDICATED IN THE GULF STREAM...SO WILL CONTINUE WITH EXERCISE
CAUTION STATEMENTS THERE. CLOSE TO THE COAST...WINDS LOOK TO BE
10-15 KNOTS...STILL NOT GREAT CONDITIONS FOR SMALL CRAFT
OPERATORS.
THU-SUN...PRESSURE GRADIENT AROUND THE ATLANTIC RIDGE OFFSHORE WILL
SUPPORT SE WINDS TO 15 KNOTS...15-20 KNOTS AT TIMES THROUGH THE
UPCOMING HOLIDAY WEEKEND. THIS WILL KEEP SEAS ELEVATED...GENERALLY
AROUND 6 FT OFFSHORE AND 4-5 FT NEAR SHORE FROM CHRISTMAS EVE
THROUGH SUNDAY.
&&
.CLIMATE...DAYTONA BEACH HAD A MORNING LOW OF 71 DEGREES THIS
MORNING AND TEMPERATURES ARE NOT FORECAST TO GO BELOW THAT THIS
EVENING...SO THEY WILL LIKELY HAVE A RECORD WARM LOW FOR TODAY.
HIGHER CHANCES FOR WARM TEMPERATURE RECORDS WED-CHRISTMAS DAY.
RECORD HIGHS TUE THROUGH FRI...
DEC-22 DEC-23 DEC-24 DEC-25
DAB 85(2013) 85(2013) 84(1981) 82(1988)
MCO 86(2013) 86(2013) 85(2014) 85(1924)
MLB 84(2013) 86(2013) 85(2014) 87(1981)
VRB 84(2013) 84(2013) 87(2014) 85(1997)
RECORD WARM LOWS TUE THROUGH FRI...
DEC-22 DEC-23 DEC-24 DEC-25
DAB 70(2006) 68(2013) 67(1997) 69(1997)
MCO 68(1911) 68(1911) 67(2006) 69(1997)
MLB 73(2006) 68(2006) 71(1987) 72(1997)
VRB 74(2006) 69(2013) 72(2014) 71(1997)
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 71 84 69 83 / 30 20 10 10
MCO 70 85 70 86 / 30 20 10 10
MLB 73 85 71 84 / 30 20 10 10
VRB 73 85 70 85 / 30 20 10 10
LEE 71 85 70 85 / 30 20 10 10
SFB 70 86 70 85 / 30 20 10 10
ORL 71 85 71 85 / 30 20 10 10
FPR 73 84 71 85 / 30 20 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM/AVIATION...LASCODY
LONG TERM....VOLKMER
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
930 AM EST TUE DEC 22 2015
.DISCUSSION...
...MUCH ABOVE NORMAL TEMPERATURES THE REST OF THE WEEK...
...MODERATE TO HIGH RISK OF RIP CURRENTS THRU THE UPCOMING HOLIDAY
WEEKEND...
TODAY/TONIGHT...LARGE HIGH PRESSURE RIDGE EXTENDING FROM NEAR BERMUDA
TO CENTRAL FLORIDA WILL PROVIDE A SOUTHEAST/SOUTH LOW LEVEL WIND
FLOW. THIS WILL ELEVATE MOISTURE LEVELS WITH FORECAST PRECIPITABLE
WATER VALUES RISING TO NEAR 1.5 INCHES BY MAX HEATING TIME. MORNING
SOUNDINGS STILL SHOW SOME DRY AND RATHER WARM MID LEVEL AIR BUT
SLIGHT COOLING OF THIS LAYER IS INDICATED BY FORECAST SOUNDINGS.
THE MAIN FORECAST PROBLEM REVOLVES AROUND POPS...AND VARIOUS MODELS
HAVE ALL DIFFERENT TYPES OF SOLUTIONS. THINK THAT THUNDERSTORM
COMPLEX VICINITY MISSISSIPPI DELTA/APALACHICOLA WILL BUILD A LITTLE
SOUTHWARD INTO THE GULF OF MEXICO AND PUMP A HIGH CLOUD CANOPY INTO
OUR NORTHERN SECTIONS. SO EVEN THOUGH SOME DIVERGENCE ALOFT IS
INDICATED THERE THIS AFTERNOON...HEATING WILL BE LIMITED AND INHIBIT
DEEP UPDRAFTS. SOUTHERN SECTIONS SHOULD HAVE THE GREATEST DIRECT
INSOLATION. THE NAM AND HRRR MODELS SHOW SOME CONVECTION WORKING UP
OUT OF SOUTH FLORIDA LATE IN THE DAY AND INTO EVENING...WITH THE
HRRR INDICATING A SLIGHT LIGHTNING RISK OVER OUR SOUTH/CENTRAL
INTERIOR. OVERALL THOUGH...DO NOT SEE ENOUGH TO ADD LIGHTNING TO
THE FORECAST YET. OUR 30 PERCENT SHOWER CHANCES EXCEPT 40 IN THE
FAR SOUTH LOOK OKAY TOO...THOUGH THESE CHANCES COULD BLEED OVER INTO
THE EARLY NIGHTTIME PERIOD.
OTHERWISE...NO CHANGES TO WARM/HUMID FORECAST FOR TODAY. SEVERAL
RECORD WARM LOWS MAY OCCUR TONIGHT.
&&
.AVIATION...SUNSHINE A BIT MUTED BY CIRRUS BUT EXPECT HEATING TO
GENERATE CLOUD FIELD WITH DECENT COVERAGE AGAIN. LOCAL MVFR
POSSIBLE BUT GENERALLY CEILINGS AT OR ABOVE FL035. CHANCE OF
AFTERNOON SHOWERS BUT NOT CERTAIN ENOUGH WITH LOCATION/TIMING TO
INCLUDE ANY TEMPO GROUPS. MOS GUIDANCE GENERATES A LOT OF STRATUS
AND FOG AGAIN TONIGHT FOR THE INTERIOR TERMINALS AND KDAB...BUT WITH
CONSIDERABLE CLOUD COVER...THIS LOOKS RATHER SKETCHY AGAIN.
&&
.MARINE...TODAY/TONIGHT...BUOYS 41009 AND 41010 SHOWING WINDS IN THE
EXERCISE CAUTION RANGE. MARINE MOS SHOWS A SLIGHT DECREASE IN WINDS
THIS AFTERNOON AND THEN AN INCREASE THIS EVENING AND OVERNIGHT.
WITH SEAS AROUND 6 FEET...PLAN TO KEEP THE CURRENT EXERCISE CAUTION
STATEMENT FOR THE OFFSHORE ZONES.
&&
.CLIMATE...DAYTONA BEACH HAD A MORNING LOW OF 71 DEGREES THIS
MORNING AND TEMPERATURES ARE NOT FORECAST TO GO BELOW THAT THIS
EVENING...SO THEY WILL LIKELY HAVE A RECORD WARM LOW FOR TODAY.
VERO BEACH WILL COME CLOSE TO REACHING THEIR RECORD HIGH FOR
TODAY. HIGHER CHANCES FOR WARM TEMPERATURE RECORDS WED-CHRISTMAS DAY.
RECORD HIGHS TUE THROUGH FRI...
DEC-22 DEC-23 DEC-24 DEC-25
DAB 85(2013) 85(2013) 84(1981) 82(1988)
MCO 86(2013) 86(2013) 85(2014) 85(1924)
MLB 84(2013) 86(2013) 85(2014) 87(1981)
VRB 84(2013) 84(2013) 87(2014) 85(1997)
RECORD WARM LOWS TUE THROUGH FRI...
DEC-22 DEC-23 DEC-24 DEC-25
DAB 70(2006) 68(2013) 67(1997) 69(1997)
MCO 68(1911) 68(1911) 67(2006) 69(1997)
MLB 73(2006) 68(2006) 71(1987) 72(1997)
VRB 74(2006) 69(2013) 72(2014) 71(1997)
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...LASCODY
LONG TERM....VOLKMER
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
852 PM EST WED DEC 23 2015
...ISOLATED SEVERE STORMS OR TORNADOES POSSIBLE MAINLY AFTER
MIDNIGHT ALONG WITH CONTINUED FLOODING THREAT...
.UPDATE...
MADE A FEW ADJUSTMENTS TO OVERNIGHT AND MORNING POP TREND THOUGH
STILL KEEP LIKELY TO CATEGORICAL GOING FOR NW MAJORITY OF CWA.
INCLUDED SEVERE MENTION AS A POSSIBILITY PRIMARILY AFTER MIDNIGHT
AS RAP INDICATING NOSE OF 500 J/KG SBCAPE MAY FINALLY MAKE A PUSH
NORTHEAST INTO THE AREA...WHICH IS ALREADY STRONGLY SHEARED
INCLUDING A ROBUST 50-60 KT 850MB JET AND A WHOPPING 500-700 M2S2
OF 0-1KM SRH. NEEDLESS TO SAY WOULD NOT TAKE MUCH TO HAVE A
GREATER SEVERE/TORNADO THREAT WITH ANY INCREASE IN INSTABILITY.
FLOODING THREAT CONTINUES ALSO...AND COULD BE A GREATER URBAN
FLOODING THREAT IF SOME OF THE LATEST WRF SOLUTIONS PAN OUT AS A
CONVECTIVE BAND STALLS FROM SW TO NE ACROSS NORTH GA WHICH COULD
INCLUDE METRO ATLANTA THURSDAY MORNING. WILL NEED TO KEEP A CLOSE
EYE ON SUBSEQUENT RUNS AND OTHER TRENDS SINCE THIS COULD
SIGNIFICANTLY RESULT IN LOCALLY HIGHER QPF VALUES. OTHERWISE MADE
JUST MINOR ADJUSTMENTS TO TEMPS/DEWPTS AND PREVIOUS DISCUSSION
FOLLOWS...
BAKER
&&
.PREV DISCUSSION... /ISSUED 732 PM EST WED DEC 23 2015/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
.FLOOD WATCH CONTINUES THROUGH FRIDAY EVENING...
MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM. LATEST RADAR
TRENDS SHOW SOUTHERN EDGE OF THE PRECIP SHIELD LIFTING NORTH. AT
THE SAME TIME TSTORMS ARE DEVELOPING ALONG THE SOUTHERN EDGE. WE
WILL SEE THE RISK OF THUNDER INCREASE ACROSS THE CWA AS THE REST
OF THIS AFTERNOON AND EVENING PROGRESSES. THERE IS A RISK OF
SEVERE STORMS AS SHEAR IS ALSO INCREASING AS WELL AS CAPE. THERE
WILL BE A LULL IN THE THUNDER LATE THIS EVENING...BUT AS THE COLD
FRONT APPROACHES THE TENNESSEE VALLEY...INSTABILITY WILL INCREASE
AGAIN ALONG WITH SHEAR AND WE WILL SEE ANOTHER ROUND OF THUNDER
WITH ANOTHER RISK OF SEVERE STORMS INCLUDING ISOLATED TORNADOES.
THE RISK WILL LIKELY CONTINUE INTO THURSDAY ACROSS NORTH GEORGIA
AS SHEAR REMAINS HIGH AND THE FRONT STALLS KEEPING HIGH CAPES
ACROSS NORTH GA. CENTRAL GA COULD SEE THUNDERSTORMS
THURSDAY...ALTHOUGH THE BETTER RISK WILL BE ACROSS NORTH GA. NEAR
RECORD/RECORD HIGH TEMPS WILL CONTINUE THROUGH THE SHORT TERM.
17
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FLOOD WATCH CONTINUES THROUGH MID DAY FRIDAY WITH THE PRIMARY
FOCUS SHIFTING TO NORTH GA AT THE BEGINNING OF THE PERIOD BEFORE
THE FLOOD THREAT DIMINISHES BY THE WEEKEND.
AT THE START OF THE PERIOD...STRONG MID LEVEL RIDGING CENTERED
JUST SOUTH OF BERMUDA HELPING TO MAINTAIN THE PERSISTENT SOUTHWEST
FLOW ALOFT ACROSS THE SOUTHEASTERN STATES. THE REMNANT BOUNDARY
THAT PLAGUES US THROUGH EARLY FRIDAY LIFTS NORTH OF THE AREA
FRIDAY NIGHT LEAVING BEHIND THE WARM SOUPY AIRMASS INTO THE
WEEKEND...BUT NOT BEFORE DROPPING ANOTHER 1 TO 2 INCHES OF
PRECIPITATION ACROSS FAR NORTH GA. BOTH THE GFS AND ECMWF
GENERALLY AGREE THAT SOUTHERN TN AND OR NORTH GA WILL HAVE A
RESIDUAL THREAT FOR HEAVY RAIN EARLY FRIDAY THROUGH MIDDAY BEFORE
LIFTING NORTH OF THE REGION. GIVEN THE REMNANT MOISTURE IN PLACE
AS THE FRONT LIFTS NORTH...AM EXPECTING SOME AREAS OF FAIRLY DENSE
FOG TO FORM FRIDAY NIGHT INTO SATURDAY AM...SO SAFE TRAVELS HOME
FOR THOSE ON THE ROAD LATE CHRISTMAS DAY. WEEKEND LOOKS GENERALLY
WARM AND PARTLY TO MOSTLY CLOUDY. CANNOT RULE OUT A STRAY SHOWER
OR TSTORM BUT NOT EXPECTING MUCH IN THE WAY OF STORMS THROUGH THE
WEEKEND.
VERY STRONG JET MAX OF 150KTS DIVING SOUTH ON THE WEST COAST OF
THE US FRIDAY AFTERNOON WILL BE THE NEXT WEATHER MAKER FOR OUR
REGION BY EARLY NEXT WEEK. BY LATE SATURDAY BOTH THE ECMWF AND GFS
CLOSE OFF A PRETTY STRONG UPPER LOW OVER NEW MEXICO SETTING THE
STAGE FOR BOTH SEVERE WEATHER AND HEAVY SNOWS IN THE SOUTHERN
PLAINS AND SOUTHERN ROCKIES. BOTH THE GFS AND ECMWF GENERALLY
AGREE ON LIFTING THAT SYSTEM NORTHEAST ALONG A VERY SIMILAR TRACK TO
THE CURRENT SYSTEM ACROSS TX..AR..AND INTO THE OHIO VALLEY. THE
DIFFERENCE IS THAT THIS SYSTEM IS A TAD CLOSER TO OUR AREA AND MAY
POSE MORE OF A SEVERE THREAT BY LATE MONDAY INTO EARLY TUESDAY.
HAVE INCLUDED LIKELY POPS DURING THAT PERIOD GIVEN THE RELATIVE
AGREEMENT BETWEEN THE LONG RANGE MODELS AND CONFIDENCE THAT WE
WILL HAVE BOTH INSTABILITY AND SHEAR ACROSS THE AREA. WILL
CERTAINLY HAVE TO WATCH THAT SYSTEM AS IT COMES CLOSER.
WITH THE UPPER SYSTEM LIFTING NORTHEAST...WE ONLY GET A MODEST
COOL DOWN IN DAYS 6 AND 7. IT ISNT UNTIL MID TO LATE WEEK WHEN
ANOTHER DISTURBANCE ROLLS THROUGH THAT HAS MUCH MORE SEASONABLE
.IE WINTER...AIRMASS ASSOCIATED WITH IT.
30
&&
.CLIMATE...
RECORDS FOR 12-23
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 73 1933 25 1989 61 1970 13 1989
1931
KATL 73 1990 22 1989 62 1879 8 1989
KMCN 82 1970 28 1989 62 1990 15 1989
KCSG 77 1990 26 1989 63 1970 14 1989
1970
RECORDS FOR 12-24
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 77 1964 31 1945 60 1964 7 1983
KATL 72 1984 28 1963 60 1879 3 1983
1964
KMCN 77 1964 35 1993 62 1964 10 1989
1983
KCSG 79 1984 35 1989 60 1988 9 1989
1964
1955
RECORDS FOR 12-25
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 77 1982 22 1983 61 1982 3 1983
1955
KATL 72 1987 17 1983 59 1982 0 1983
1889
KMCN 78 1982 25 1983 61 1982 7 1983
1932
KCSG 76 1982 24 1983 60 1982 8 1983
1964
RECORDS FOR 12-26
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 74 1964 30 1980 61 1987 9 1983
1928
KATL 72 1987 26 1935 61 1987 5 1983
KMCN 77 1987 33 1902 61 1987 9 1983
1982 1964
KCSG 80 1987 33 1983 64 1987 10 1983
RECORDS FOR 12-27
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 73 1971 33 1917 56 1982 11 1935
KATL 71 1982 27 1892 58 1982 12 1925
1889
KMCN 78 1987 35 1902 61 1987 17 1902
KCSG 75 2008 43 1948 61 1987 23 1985
1982
RECORDS FOR 12-28
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 78 1928 32 1950 59 1982 8 1925
KATL 74 1984 15 1894 58 1954 5 1925
1971
KMCN 76 2008 31 1925 65 1942 11 1925
2007
KCSG 80 1984 36 1950 59 2008 23 2010
1954 1977
&&
.AVIATION...
00Z UPDATE...
MAINLY IFR CIGS AND IFR/MVFR VSBYS EXPECTED THROUGH TONIGHT AND
INTO THURSDAY WITH POSSIBLE IMPROVEMENT BY AFTERNOON. SHOWER AND
ISOLATED THUNDER THREAT SHOULD CONTINUE FOR MAJORITY OF SITES WITH
KMCN POSSIBLY GETTING JUST SOUTH OF MOST COVERAGE. INCLUDED TEMPO
FOR TSRA THROUGH EVENING THOUGH MAY NEED TO USE AGAIN OVERNIGHT
WITH ANOTHER POSSIBLE LINE ACROSS THE NORTH SITES THAT COULD
LINGER INTO THURSDAY. WINDS INITIALLY SSE NEAR 7-10 KTS BECOMING
MOSTLY SSW UNDER 10KTS LATER TONIGHT AND THURSDAY.
//ATL CONFIDENCE...00Z UPDATE...
MEDIUM ON CIGS/VSBYS AND TIMING OF SSW WIND SHIFT.
HIGH ON ALL ELSE.
BAKER
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 62 73 65 74 / 100 60 60 40
ATLANTA 62 73 65 74 / 100 70 70 40
BLAIRSVILLE 60 70 61 71 / 100 80 70 60
CARTERSVILLE 62 74 64 74 / 100 70 70 40
COLUMBUS 63 76 66 78 / 100 60 50 20
GAINESVILLE 61 71 64 72 / 100 70 70 40
MACON 63 76 65 78 / 100 40 30 10
ROME 63 74 63 75 / 100 80 70 40
PEACHTREE CITY 62 74 65 75 / 100 60 60 40
VIDALIA 64 81 66 81 / 60 20 20 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...BUTTS...
CARROLL...CATOOSA...CHATTAHOOCHEE...CHATTOOGA...CHEROKEE...
CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...DADE...
DAWSON...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...FANNIN...
FAYETTE...FLOYD...FORSYTH...GILMER...GLASCOCK...GORDON...
GREENE...GWINNETT...HALL...HANCOCK...HARALSON...HARRIS...HEARD...
HENRY...HOUSTON...JACKSON...JASPER...JEFFERSON...JOHNSON...
JONES...LAMAR...LAURENS...LUMPKIN...MACON...MADISON...MARION...
MERIWETHER...MONROE...MONTGOMERY...MORGAN...MURRAY...MUSCOGEE...
NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...PAULDING...PEACH...
PICKENS...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...SCHLEY...
SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TOWNS...TREUTLEN...
TROUP...TWIGGS...UNION...UPSON...WALKER...WALTON...WARREN...
WASHINGTON...WEBSTER...WHEELER...WHITE...WHITFIELD...WILCOX...
WILKES...WILKINSON.
&&
$$
SHORT TERM...17/BAKER
LONG TERM....30
AVIATION...BAKER
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
844 PM CST WED DEC 23 2015
.UPDATE...
ISSUED AT 840 PM CST WED DEC 23 2015
Cold front in the process of pushing through the forecast area
this evening accompanied by strong southwest to west winds gusting
up to 45 mph at times. Strongest surface pressure rises now
shifting quickly to our north this hour suggesting our bout with
strong winds will be short lived with most areas seeing the winds
subside after midnight. The showers and storms quickly exited the
forecast area around 00z with some lower clouds streaming in from
the west signaling a change to cooler weather for the next couple
of days. Have made some adjustments to the forecast with respect
to removing precip for the overnight hours and tweaking the wind
gusts thru late this evening. Expanded the Wind Advisory a bit
further east for the rest of the evening hours as well. Should
have the latest update out by 900 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 312 PM CST WED DEC 23 2015
First round of severe weather has exited the eastern forecast area
early this afternoon, but storms have quickly started to fire in
northeast Missouri. This particular area has seen some sunshine
during the afternoon, helping to destabilize the atmosphere, where
CAPE`s are above 500 J/kg and 0-6km bulk shear is an impressive 60-
70 knots. HRRR latched onto this area of development earlier, and
races it across the northern part of the forecast area between 4 pm
and 8 pm. Have concentrated the highest PoP`s for the rest of the
afternoon in this area. The storms should be weakening after sunset
as the surface low pulls northeast, and there is some question about
how much the atmosphere across the eastern CWA can recover after
being thoroughly worked over the last several hours.
Secondary concern is with the winds this evening. Have issued a Wind
Advisory for the period from 6 pm to 2 am across about the northwest
half of the forecast area. Main surface low is currently located
across northeast Iowa, and will be zipping northeast. Impressive 3-
hour pressure rises of 10-11 mb are progged to track northeastward
to around Rockford by midnight. Wind gusts of 45 mph or so are
likely across the northwest half of the forecast area as this
bullseye passes. Have gone as far south as Jacksonville with the
advisory, but this area may be of a shorter duration. Most of the
winds should be diminishing around midnight, but will linger a bit
longer north of I-74.
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 312 PM CST WED DEC 23 2015
Short and medium range models are in fairly good agreement with the
overall active weather pattern through the weekend and into early
next week. Unseasonably warm temperatures and very wet weather will
be the main factors for the weekend through late Monday.
In the shorter term, mild temperatures and periods of cloudiness can
be expected for Christmas Eve into much of Christmas Day. The return
of a surface boundary north of the Ohio Valley and associated weak
isentropic lift initially will result in a chance for light rain in
southeast IL late on Christmas Day. The GFS is the odd model out on
this one by keeping the boundary much farther south.
Backing upper level flow in response to a digging trough in the
western U.S. will allow very warm and moist air to return into much
of central and SE IL during the day Saturday. This feed of moisture
and the associated rainfall will linger in the forecast area through
most of Sunday, resulting in 2.50 to 3.50 inches of rain. The
precipitation area will gradually sag south as the upper low in the
west closes off in SW Texas and an upper level confluent area sets
up across central IL by later in the day Sunday.
The upper low in the southwestern U.S. is expected to kick out
toward the Midwest Monday as another strong upper level trough digs
from the Pacific NW to the southern Plains. This will bring the
likelihood of precipitation back to central IL for Monday. The
forecast type becomes a bit tricky north of a Rushville-Bloomington
line Monday into Monday night as upper level soundings indicate a
mix of rain/snow/sleet possible. Could be some minor accumulations
of snow NW of Peoria late Monday, but there is a lot of uncertainty
with this scenario 6 days out.
&&
.AVIATION...(For the 00Z TAFS through 00Z Thursday evening)
ISSUED AT 500 PM CST WED DEC 23 2015
Cold front pushing into extreme west central Illinois will sweep
across the forecast area over the next several hours accompanied
by widely scattered showers and storms and strong gradient winds.
Look for south winds to veer more south-southwest and increase
to between 25 to 35 kts with gusts near 45 kts at times before
diminishing after 07z. Latest satellite data and surface obs to
our west indicate another band of MVFR cigs approaching the river
and based on timing, should begin to affect PIA and SPI by 01z,
BMI to CMI by 02z. Bases should run from 1000-2000 feet with about
a 3-5 hour stay in our TAF area before VFR conditions return after
07z.
&&
.ILX Watches/Warnings/Advisories...
Wind Advisory until 2 AM CST Thursday for ILZ027>031-036>038-
040>053.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Miller
AVIATION...Smith
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1149 AM CST TUE DEC 22 2015
.UPDATE...
ISSUED AT 922 AM CST TUE DEC 22 2015
Large shield of stratus remains in place over the area this
morning, with cirrus starting to move in on top of it west of the
Illinois River. While most of the computer models show some
scouring out of the low clouds, our morning sounding showed a
rather a rather tight inversion around 2000 feet that likely will
not be going anywhere fast. HRRR guidance shows a couple thin
spots trying to form, but largely keeps the low clouds over the
entire area into the evening. The existing sky grids already had a
good handle on that. Because of the extensive clouds, have lowered
highs a couple degrees across the northern CWA, but temperatures
still will get a nice bump upward as the southerly flow gets
stronger this afternoon.
Minor grid updates have been sent, but no changes to the worded
forecast are needed at this time.
&&
.SHORT TERM...(Today)
ISSUED AT 330 AM CST TUE DEC 22 2015
Cold front that triggered scattered showers and thunderstorms across
east-central and southeast Illinois earlier this evening has now
pushed into Indiana, leaving behind cloudy but dry conditions across
the KILX CWA early this morning. Despite surface high pressure
building into the region, do not think any clearing will occur
today. Models show a strong subsidence inversion developing at
around 925mb, essentially trapping the lingering boundary layer
moisture in the form of a low overcast. With such a strong
inversion in place and no appreciable advection to get rid of the
clouds, see little hope for any sunshine today. Due to the
extensive cloud cover, have undercut the MAV guidance numbers,
resulting in high temperatures in the middle to upper 40s.
.LONG TERM...(Tonight through Monday)
ISSUED AT 330 AM CST TUE DEC 22 2015
Warm and unsettled weather will be the rule over the next several
days...with the potential for severe thunderstorms and record high
temperatures on Wednesday and copious amounts of rainfall next
weekend.
As high pressure moves off to the east, increasing southwesterly
flow will bring warmer/more humid air into the region tonight into
Wednesday. NAM forecast soundings are showing the boundary layer
becoming saturated as increasing moisture flows northward,
suggesting the potential for fog/drizzle tonight. With low pressure
ejecting out of the Rockies, scattered showers will arrive late
tonight, although the bulk of the precipitation will hold off until
Wednesday.
A potentially volatile day is unfolding on Wednesday as deepening
low pressure tracks from near Kansas City early in the day to Lake
Superior by evening. Strong southerly winds gusting to between 30
and 40 mph ahead of the approaching system will bring an
unseasonably warm and humid airmass into Illinois, with afternoon
high temperatures climbing to near record levels in the middle 60s
and surface dewpoints reaching the middle to upper 50s. Models
continue to show strong instability developing for this time of
year, with NAM SBCAPES of 500-1000J/kg and lifted index values of -2
to -4C. At the same time, 0-6km bulk shear will increase to between
70 and 80kt along/south of the I-70 corridor. Latest Day 2
convective outlook from SPC now places all areas east of the
Illinois River under a Slight Risk for severe. Based on current
projections and model forecast parameters, it appears the primary
severe weather threats will be damaging wind gusts and large hail,
although an isolated tornado will also be possible given the
increasing shear values. The main time frame for severe will be
during the afternoon east of the Illinois River, shifting to
along/east of the I-57 corridor by early evening. Cold front will
sweep through the region by around midnight, with rain chances
ending overnight.
Once the Wednesday system departs, quiet weather will be on tap for
both Thursday and Friday with dry conditions and mild high
temperatures in the 40s and 50s. After that, a return to warm/wet
weather is in store by next weekend as deep-layer southwesterly flow
re-establishes itself across the central/eastern CONUS in advance of
the next major storm system. All models show an upper trough
digging southward across the western CONUS late in the week,
eventually forming a closed low over the Desert Southwest by
Saturday. How quickly this feature ejects northeastward is still in
question, with the 00z Dec 22 GFS showing a much faster solution
than the ECMWF. With such a deep closed low expected to form and
essentially cut itself off from the main flow well to the north,
think slower is the way to go. As a result, have trended toward the
ECMWF from Saturday through Monday. The ECMWF shows rain spreading
northward well ahead of the upper low along a prevailing baroclinic
zone Saturday/Saturday night. After that, rain will continue
through early next week...although there is some indication that a
northern stream short-wave may temporarily push the frontal boundary
a bit further southward and possibly bring a break in the precip
late Sunday into Monday before the upper low tracks into the region
by Monday night into Tuesday. At this point, will just keep PoPs
going right through the period and will make adjustments as
necessary as better model agreement is achieved.
&&
.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
ISSUED AT 1150 AM CST TUE DEC 22 2015
IFR conditions remain widespread at midday. Some breaks in the
clouds developing near KSPI with the edge of the stratus deck
along the Missouri River north of KSTL. Will need to watch to see
if this can make more progress into central Illinois, but
currently think that there would only be an improvement to MVFR
at best, as wind trajectory becomes more southerly and pushes the
clearing line further north. Some of the high-resolution guidance
has been suggesting some dense fog development in east central
Illinois late this afternoon into evening. Winds increase quite a
bit and would not necessarily favor dense fog, but have lowered
visibilities somewhat before a more widespread 1SM this evening as
was indicated in the previous TAF set. Showers will quickly work
their way across central Illinois Wednesday morning as a strong
storm system lifts northeast across Iowa. Thunder potential is a
bit borderline at the moment and have left it out, but will need
to be monitored. The storm is rather intense, so winds will ramp
up and gust near 30 knots by midday in most of the area.
&&
.CLIMATE...
ISSUED AT 932 AM CST TUE DEC 22 2015
Record highs for Wednesday:
Bloomington/Normal......... 63 in 1933
Champaign/Urbana........... 64 in 1933
Charleston/Mattoon......... 69 in 1933
Danville................... 65 in 1933
Decatur.................... 66 in 1933
Effingham.................. 68 in 1933
Jacksonville............... 70 in 1933
Lincoln.................... 65 in 1933
Olney...................... 67 in 1931
Peoria..................... 65 in 1933
Springfield................ 66 in 1933
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Geelhart
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
933 AM CST TUE DEC 22 2015
.UPDATE...
ISSUED AT 922 AM CST TUE DEC 22 2015
Large shield of stratus remains in place over the area this
morning, with cirrus starting to move in on top of it west of the
Illinois River. While most of the computer models show some
scouring out of the low clouds, our morning sounding showed a
rather a rather tight inversion around 2000 feet that likely will
not be going anywhere fast. HRRR guidance shows a couple thin
spots trying to form, but largely keeps the low clouds over the
entire area into the evening. The existing sky grids already had a
good handle on that. Because of the extensive clouds, have lowered
highs a couple degrees across the northern CWA, but temperatures
still will get a nice bump upward as the southerly flow gets
stronger this afternoon.
Minor grid updates have been sent, but no changes to the worded
forecast are needed at this time.
&&
.SHORT TERM...(Today)
ISSUED AT 330 AM CST TUE DEC 22 2015
Cold front that triggered scattered showers and thunderstorms across
east-central and southeast Illinois earlier this evening has now
pushed into Indiana, leaving behind cloudy but dry conditions across
the KILX CWA early this morning. Despite surface high pressure
building into the region, do not think any clearing will occur
today. Models show a strong subsidence inversion developing at
around 925mb, essentially trapping the lingering boundary layer
moisture in the form of a low overcast. With such a strong
inversion in place and no appreciable advection to get rid of the
clouds, see little hope for any sunshine today. Due to the
extensive cloud cover, have undercut the MAV guidance numbers,
resulting in high temperatures in the middle to upper 40s.
.LONG TERM...(Tonight through Monday)
ISSUED AT 330 AM CST TUE DEC 22 2015
Warm and unsettled weather will be the rule over the next several
days...with the potential for severe thunderstorms and record high
temperatures on Wednesday and copious amounts of rainfall next
weekend.
As high pressure moves off to the east, increasing southwesterly
flow will bring warmer/more humid air into the region tonight into
Wednesday. NAM forecast soundings are showing the boundary layer
becoming saturated as increasing moisture flows northward,
suggesting the potential for fog/drizzle tonight. With low pressure
ejecting out of the Rockies, scattered showers will arrive late
tonight, although the bulk of the precipitation will hold off until
Wednesday.
A potentially volatile day is unfolding on Wednesday as deepening
low pressure tracks from near Kansas City early in the day to Lake
Superior by evening. Strong southerly winds gusting to between 30
and 40 mph ahead of the approaching system will bring an
unseasonably warm and humid airmass into Illinois, with afternoon
high temperatures climbing to near record levels in the middle 60s
and surface dewpoints reaching the middle to upper 50s. Models
continue to show strong instability developing for this time of
year, with NAM SBCAPES of 500-1000J/kg and lifted index values of -2
to -4C. At the same time, 0-6km bulk shear will increase to between
70 and 80kt along/south of the I-70 corridor. Latest Day 2
convective outlook from SPC now places all areas east of the
Illinois River under a Slight Risk for severe. Based on current
projections and model forecast parameters, it appears the primary
severe weather threats will be damaging wind gusts and large hail,
although an isolated tornado will also be possible given the
increasing shear values. The main time frame for severe will be
during the afternoon east of the Illinois River, shifting to
along/east of the I-57 corridor by early evening. Cold front will
sweep through the region by around midnight, with rain chances
ending overnight.
Once the Wednesday system departs, quiet weather will be on tap for
both Thursday and Friday with dry conditions and mild high
temperatures in the 40s and 50s. After that, a return to warm/wet
weather is in store by next weekend as deep-layer southwesterly flow
re-establishes itself across the central/eastern CONUS in advance of
the next major storm system. All models show an upper trough
digging southward across the western CONUS late in the week,
eventually forming a closed low over the Desert Southwest by
Saturday. How quickly this feature ejects northeastward is still in
question, with the 00z Dec 22 GFS showing a much faster solution
than the ECMWF. With such a deep closed low expected to form and
essentially cut itself off from the main flow well to the north,
think slower is the way to go. As a result, have trended toward the
ECMWF from Saturday through Monday. The ECMWF shows rain spreading
northward well ahead of the upper low along a prevailing baroclinic
zone Saturday/Saturday night. After that, rain will continue
through early next week...although there is some indication that a
northern stream short-wave may temporarily push the frontal boundary
a bit further southward and possibly bring a break in the precip
late Sunday into Monday before the upper low tracks into the region
by Monday night into Tuesday. At this point, will just keep PoPs
going right through the period and will make adjustments as
necessary as better model agreement is achieved.
&&
.AVIATION...(For the 12Z TAFS through 12Z Wednesday morning)
ISSUED AT 528 AM CST TUE DEC 22 2015
IFR conditions at all sites at the start and based on satellite
trends and that a sfc ridge is moving over the area, which should
strengthen any inversion already in place, thinking is that the
clouds below 1kft will not be going anywhere. Low sun angle will
not help either. Thinking is that cig heights at SPI and DEC could
come up to 1kft around mid morning, but other sites will remain
IFR until sometime late afternoon. Unfortunately do not see the
inversion ending this evening and HiRes models hinting at possible
dense fog occurring in the area this evening. So, have included an
entry for IFR conditions returning this evening and this could
last through overnight. HiRes models also showing lower vis with
the fog. Unsure how low it will get with no radiation cooling
occurring under cloudy skies. Think fog will form due to increased
low level moisture/dewpoints. Will just have vis drop to 1sm BR,
but it could go lower...will let next forecast take a closer look
at that. Winds will be westerly ahead of the ridge, but then
become southwesterly, then southeasterly this afternoon, and
continuing through the evening.
&&
.CLIMATE...
ISSUED AT 932 AM CST TUE DEC 22 2015
Record highs for Wednesday:
Bloomington/Normal......... 63 in 1933
Champaign/Urbana........... 64 in 1933
Charleston/Mattoon......... 69 in 1933
Danville................... 65 in 1933
Decatur.................... 66 in 1933
Effingham.................. 68 in 1933
Jacksonville............... 70 in 1933
Lincoln.................... 65 in 1933
Olney...................... 67 in 1931
Peoria..................... 65 in 1933
Springfield................ 66 in 1933
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Geelhart
SHORT TERM...Barnes
LONG TERM...Barnes
AVIATION...Auten
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
NWS DES MOINES IA
409 PM CST TUE DEC 22 2015
.SHORT TERM /TONIGHT/...
ISSUED AT 345 PM CST TUE DEC 22 2015
REMNANTS OF THE MORNING STRATUS SHIELD REMAIN OVER THE NORTHEASTERN
THIRD TO HALF OF THE STATE AND WILL GENERALLY REMAIN SO THIS EVENING
AS THE STRONG INVERSION REMAINS IN PLACE AND WE LOSE WHATS LEFT OF
ANY DAYTIME HEATING AND MIXING. AS A RESULT...CEILINGS AND
VISIBILITIES WILL CONTINUE TO BE LOW IN THOSE AREAS...AROUND 500
FEET AND A COUPLE MILES OR LESS RESPECTIVELY THROUGH THE SHORT TERM.
HAVE NOT CURRENTLY INTRODUCED FOG INTO THE GRIDS...BUT MAY WARRANT
SO DURING THE EVENING...ESPECIALLY FOR AREAS THAT HOLD OFF ON SEEING
PRECIP LONGER AND MOISTURE ADVECTION CONTINUES. AREAS THAT SAW
CLEARING WILL PROGRESSIVELY SEE HIGH BASED CLOUDS MOVE IN BEFORE
CEILINGS FALL AGAIN AS SURFACE LOW AND FORCING PROGRESSES TOWARDS
THE REGION FROM CENTRAL/EASTERN KANSAS.
THE AFOREMENTIONED SURFACE LOW WILL BE THE MAIN CONCERN IN THE SHORT
TERM...BEGINNING TO REALLY INFLUENCE THE AREA AFTER 03Z. THROUGH THE
DAY...NAM AND HRRR HAVE TENDED TO HANDLE THE CLEARING BEST...SO HAVE
TRENDED THAT WAY IN THE GRIDS FOR THIS EVENING. WITHIN THE SHORT
TERM WINDOW...BEST INITIAL FORCING IS THERMODYNAMIC WITH A GOOD PUSH
OF THETA-E ADVECTION ALONG WITH ISENTROPIC LIFT IN THE 290K REGION.
THE DEFORMATION ZONE WILL ALSO BEGIN TO SET UP IN NORTHWEST IOWA
AFTER 06Z...FURTHER BOOSTING LIFT. CURRENTLY...THE COLUMN IS QUITE
DRY FROM ABOUT 850MB TO 500MB...WHICH CALLS INTO SOME QUESTION WHEN
THE COLUMN WILL SATURATE AND PRECIP WILL BEGIN...BUT BEGAN TO UP
POPS IN NORTHWEST IOWA AROUND 5Z AND THROUGH THE SHORT TERM WINDOW
IN CONJUNCTION WITH HRRR/NAM SOLUTIONS.
.LONG TERM /WEDNESDAY THROUGH TUESDAY/...
ISSUED AT 345 PM CST TUE DEC 22 2015
THE LONG TERM REMAINS ACTIVE WITH SEVERAL SHORTWAVES EJECTING OUT
OF THE BAST OF A LONG WAVE TROUGH OUT WEST. WE BEGIN THE PERIOD
WITH THE SYSTEM AFFECTING THE SHORT TERM LIFTING NORTHEAST. THERE
WILL BE A BRIEF PERIOD OF OF SNOW ON THE BACKSIDE OF THIS SYSTEM
AS IT LIFTS OFF TO THE NORTHEAST. MOST OF THE FORCING EXITS BEFORE
THE CHANGEOVER SO I AM NOT LOOKING AT MUCH ACCUMULATION PLUS WE
WILL BE TOO WARM ALOFT...MAY EVEN SEE A BIT OF FREEZING RAIN WITH
THIS. ALSO...SOME INSTABILITY WORKS INTO EASTERN IOWA AS THIS
SYSTEM LIFTS OUT WHICH MEANS WE COULD SEE SOME ISOLATED THUNDER
WEDNESDAY AFTERNOON. AFTER THIS SYSTEM DEPARTS THERE WILL BE A
BRIEF RESPITE WEDNESDAY NIGHT BEFORE ANOTHER WEAK SHORTWAVE
TRANSLATES ACROSS THE SOUTH AND EAST. TEMPS WILL BE WARM ENOUGH
FOR RAIN WITH THIS SO NOT FORESEEING MUCH IN THE WAY OF TRAVEL
PROBLEMS BUT WITH RIVERS STILL VERY HIGH...ANY HEAVIER RAINFALL
WILL LIKELY RESULT IN FLOODING AGAIN.
THE NEXT MAIN SYSTEM WILL BE A DEEPENING LOW ACROSS THE SOUTHERN
PLAINS LIFTING NORTHEAST. I THINK THE MODELS ARE LIKELY TOO FAST
WITH THIS SYSTEM GIVEN HOW THE LOW IS DEEPENING BUT INITIALLY THIS
WILL BE A RAIN PRODUCER WITH COLD AIR WRAPPING INTO THE LOW
CHANGING PRECIP OVER TO SNOW. THIS ONE MAY BE A POTENTIAL SNOW
PRODUCER FOR US AND NEEDS TO BE WATCHED BUT WILL ALSO BRING
ADDITIONAL FLOODING THREATS.
&&
.AVIATION...22/18Z
ISSUED AT 1144 AM CST TUE DEC 22 2015
IFR/LIFR CIGS CONTINUE TO DOMINATE EASTERN TWO THIRDS OF
STATE...WHILE CLEARING IS RAPIDLY MOVING INTO EASTERN AND CENTRAL
IOWA. MODELS HAVE NOT HANDLED CLEARING SKIES WELL...BUT TRENDS
SUGGEST IT WILL CONTINUE WELL INTO CENTRAL AND EVEN EASTERN IOWA
BEFORE CLOUDING BACK OVER LATER TODAY/THIS EVENING. WINDS WILL BE
GUSTY AT TIMES TODAY WITH SOUTHEASTERLY WINDS AROUND 15 TO 20 MPH
GUSTING TOWARDS 30 MPH AT TIMES. RETURN OF MVFR/IFR CONDITIONS
OVERNIGHT AS LOW PRESSURE MOVES IN...DROPPING CIGS AND VSBYS...AND
EVENTUALLY RAIN AFTER 06-09Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CURTIS
LONG TERM...FAB
AVIATION...CURTIS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1218 PM CST TUE DEC 22 2015
.UPDATE...
ISSUED AT 1215 PM CST TUE DEC 22 2015
LOW STRATUS/MOISTURE TRAPPED UNDER A STRONG INVERSION THIS MORNING
WAS KEEPING TEMPERATURES IN CHECK...ONLY IN THE LOWER TO MID 30S
AT MANY LOCATIONS. VISIBLE SATELLITE SHOWS THIS STRATUS BEING
SCOURED OUT ACROSS WESTERN IA AND CENTRAL MO DUE TO STRENGTHENING
LOW/MID LEVEL WARM AIR ADVECTION. THIS SCOURING OUT OF THE STRATUS
SHOULD MAKE IT INTO THE DVN CWA LATE THIS AFTERNOON. HOWEVER...
THICKENING CIRRUS WILL ALSO BE OVER THE CWA SO THE BOTTOM LINE IS CLOUDY
OR MOSTLY CLOUDY SKIES WILL REMAIN. WITH CONTINUED SOUTHEAST WINDS
THIS AFTERNOON MAXIMUM TEMPERATURES WILL ACTUALLY OCCUR LATE IN
THE DAY OR EARLY THIS EVENING.
STORM SYSTEM STILL EXPECTED TO IMPACT THE MIDWEST LATER TONIGHT
AND ESPECIALLY ON WEDNESDAY. INTENSE CYCLONE WILL TRACK FROM THE
OK PANHANDLE (TONIGHT) TO CENTRAL IA NOON WEDNESDAY (984 MB) AND
THEN TO NORTHERN WI BY WEDNESDAY EVENING (981 MB). THIS WILL PULL
DEEP MOISTURE NORTHWARD ON A 60 KNOT LOW LEVEL JET WITH PWAT`S
INCREASING TO OVER 1 INCH. AHEAD OF THE COLD FRONT VERY STRONG
DEEP LAYER SHEAR WILL EXIST BUT CAPE WILL BE MINIMAL. THE SEVERE
THREAT (INCLUDING TORNADOES) LOOKS TO BE SOUTH AND EAST OF THE
DVN CWA WHERE THE AXIS OF THE STRONGEST LOW LEVEL JET AND HIGHER
CAPE WILL BE LOCATED. HOWEVER...IF OUR EAST/SOUTHEAST CWA CAN GET
ENOUGH SUNSHINE AND A BIT MORE INSTABILITY THEN AT LEAST ISOLATED
DAMAGING WIND OR HAIL IS POSSIBLE...AND A BRIEF TORNADO CAN`T BE
RULED OUT. SPC HAS PULLED THE MARGINAL RISK A BIT FARTHER WEST
INTO EXTREME EASTERN IA. OTHERWISE...MODERATE TO LOCALLY HEAVY
RAINFALL IS LIKELY WHICH WOULD AGGRAVATE THE ALREADY ONGOING RIVER
FLOODING SITUATION.
RECORD HIGH TEMPERATURE IS ALSO POSSIBLE AT MOLINE ON WEDNESDAY
WITH THE RECORD FOR DECEMBER 23 OF 59 SET IN 1982...WHICH ALSO
HAPPENED TO BE A STRONG EL NINO YEAR (1982-83).
&&
.SYNOPSIS...
ISSUED AT 337 AM CST TUE DEC 22 2015
WEAK SURFACE RIDGE IS BUILDING INTO THE AREA EARLY THIS AM.
SATELLITE AND OBS SHOW STRATUS BLANKETING THE ENTIRE AREA AND
MUCH OF THE MIDWEST... WITH THE BACK EDGE NEAR THE MISSOURI
RIVER VALLEY SHOWING LITTLE MOVEMENT HOLDING FIRM BENEATH STRONG
850 MB INVERSION. WEAK ISENTROPIC ASCENT AND WEAK CONVERGENCE
WITH SURFACE TROUGH PRODUCED PATCHY TO AREAS OF FOG AND DRIZZLE
LAST EVENING INTO THE OVERNIGHT... BUT SEEING A DIMINISHING TREND
EARLY THIS AM AS THIS LIFT MIGRATES EAST. WATER VAPOR SHOWS
UPPER LEVEL SHORTWAVE MOVING ACROSS THE UPPER MIDWEST WITHIN
SEMI-ZONAL FLOW PATTERN. MUCH STRONGER WAVE WAS NOTED OVER THE
NORTHERN ROCKIES IN LEFT EXIT REGION OF VIGOROUS UPPER LEVEL JET
NOSING FROM EASTERN PACIFIC INTO THE WESTERN CONUS. THIS SYSTEM
LOOKS TO SHIFT ACROSS THE UPPER MIDWEST ON WEDNESDAY BRINGING
OUR NEXT ROUND OF WET WEATHER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM CST TUE DEC 22 2015
MAIN CHALLENGES ARE CLOUD TRENDS AND IMPACT ON HIGHS... THEN RAIN
CHANCES LATER TONIGHT.
DONT FORESEE MUCH EROSION OF THE STRATUS THIS AM WITH SFC RIDGE
SLIDING ACROSS REGION WITH LIMITED MIXING AND STRONG 850 MB
INVERSION IN PLACE. HOWEVER... REMAINS TO BE SEEN WITH PASSAGE
OF THE MID LEVEL WAVE THIS AM IF INCREASING SUBSIDENCE IN WAKE
CAN HELP BRING ABOUT SOME EROSION AND NOTICING LAST FEW RUNS OF
HRRR DEPICT SOME DECREASE IN LOWER CLOUDS NORTH LATE AM INTO THE
PM. SATELLITE TRENDS ALSO SHOW LITTLE MOVEMENT TO BACK EDGE OF THE
STRATUS NEAR THE MISSOURI RIVER VALLEY EARLY THIS AM... AND SOME
OF THE HI-RES GUIDANCE IS PRETTY AGGRESSIVE IN ERODING THIS FROM
THE SOUTH THIS AFTERNOON INTO EASTERN IA AND WESTERN IL... BUT
NOTICING HRRR TRENDING SLOWER WITH THIS PROCESS AND WOULD SUGGEST
SOME EROSION UP TO OUR SOUTHERN CWA BUT MAINLY FURTHER SOUTH.
DO FEEL SOME EROSION OF STRATUS IS LIKELY ESPECIALLY ON THE WEST
AND SOUTH SIDE OF DECK WITHIN DEVELOPING STRONGER SOUTHERLY FLOW
AND MIXING... BUT ALSO EXPECT INCREASING HIGH CLOUDS AND WITH
THE FLOW GENERALLY SSE NOT FEELING GOOD ON PROSPECTS FOR MUCH IN
WAY OF SUNSHINE TODAY AND THUS STAYED WITH CLOUDY-MOCLDY SKY
FORECAST TODAY. AS A RESULT OF STAYING PESSIMISTIC WITH CLOUDS
LOWERED HIGHS A TOUCH AND SIDED ON COOL SIDE OF GUIDANCE BLEND
WITH RANGE AROUND 40 TO MID 40S. HOWEVER... IF NO LIFTING OR
THINNING OF STRATUS OCCURS THEN WILL BE COLDER AND MORE IN RANGE
OF MID 30S NORTH TO LOWER 40S SOUTH. ON THE OTHER SIDE OF THIS
IF WE WERE TO SEE MORE EROSION OF STRATUS THIS AFTERNOON WITH
ONSET OF GUSTY SSE WINDS AND BETTER MIXING THEN COULD EASILY SEE
HIGHS WELL INTO THE 40S TO LOWER 50S. BOTTOM LINE... AS CLOUD
TRENDS GO... SO GO TEMPS. TYPICALLY BETTER TO STAY CONSERVATIVE/
PESSIMISTIC WITH CLOUD AND TEMP TRENDS THIS TIME OF YEAR... AS
DECEMBER IS OUR CLOUDIEST MONTH.
AS FOR WINDS TODAY... SHOULD BECOME GUSTY BY AFTERNOON FROM S/SE
15-25 MPH... WITH TIGHTENING PRESSURE GRADIENT BETWEEN NORTHERN
PLAINS TO LEE SIDE CYCLONES AND GREAT LAKES HIGH PRESSURE RIDGE.
WINDS LIKELY TO REMAIN OCCASIONALLY GUSTY TONIGHT WITH CONTINUED
RAMPING UP OF LOW LEVEL JET AND LINGERING SFC PRESSURE GRADIENT.
ISENTROPIC ASCENT/WARM ADVECTION WITH STRENGTHENING LOW LEVEL JET
SHOULD FOSTER INCREASING SHOWER ACTIVITY OVERNIGHT... ESPECIALLY
WEST AND SOUTHWEST OF QUAD CITIES. CANT RULE OUT A RUMBLE OF
THUNDER ESPECIALLY FAR SOUTHWEST CWA WITHIN PLUME OF STEEP LAPSE
RATES 7-8C/KM IN 600-750 LAYER... BUT FEELING FAIRLY ISOLATED AND
HAVE LEFT OUT MENTION ATTIM.
TEMPS SHOULD DROP VERY LITTLE EARLY THIS EVENING AND PRETTY MUCH
BE STEADY TO GRADUALLY RISING TONIGHT WITH CONTINUED WARM
ADVECTION. DEPENDING ON WHAT TEMPS DO TODAY... ITS VERY POSSIBLE
TO SEE HIGHS FOR THE DAY SOME AREAS OCCUR THIS EVENING...
ESPECIALLY NORTHERN CWA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 337 AM CST TUE DEC 22 2015
MAIN FORECAST CONCERN FOR THE LONG TERM ARE THE CHANCES FOR
PRECIPITATION AND THE CHANGING GUIDANCE. GUIDANCE HAS NOT SETTLED
ON ANY SOLUTIONS PAST TOMORROW. THIS LEADS TO AN OVERALL POOR
CONFIDENCE IN THE FORECAST. MAIN ISSUE WITH THIS IS THAT SOME OF
THE MODEL SOLUTIONS SUGGEST THE POTENTIAL FOR A SIGNIFICANT RAINFALL
EVENT BOTH WEDNESDAY AND AGAIN TOWARDS THE END OF THE WEEKEND. THESE
EVENTS...IF THEY OCCUR WOULD ONLY EXASPERATE AN ALREADY ATYPICAL
DECEMBER HYDRO EVENT.
WEDNESDAY...WEDNESDAY NIGHT...
MODELS ARE IN GOOD AGREEMENT WITH THE TRACK OF THE LOW ACROSS THE
AREA. MUCH LIKE YESTERDAY...TEMPERATURES WILL BE THE 40S TO 50S
ACROSS THE CWA AND MOISTURE STREAMS INTO THE AREA. WITH PWATS WELL
ABOVE NORMAL AND APPROACHING 1 INCH ACROSS THE AREA...THE POTENTIAL
FOR MODERATE RAINFALL EXISTS. IT APPEARS THAT WE ONCE AGAIN HAVE A
THREAT FOR THUNDERSTORMS WITH THIS SYSTEM AS THE CLEAR SLOT MAKES
ITS WAY INTO THE AREA. LAPSE RATES SHOULD STEEPEN IN THE MIXED
PHASE REGION OF AN UPDRAFT...THIS INCREASES THE CHANCES FOR
THUNDER...ESPECIALLY SOUTH AND THEN EAST OF THE QC. SPC HAS THIS
AREA IN A MARGINAL RISK FOR SEVERE WEATHER ON WEDNESDAY WITH THE
SLIGHT RISK NOT FAR TO OUR EAST. MY GUT IS TELLING ME THAT THE BEST
CHANCE FOR SEVERE WILL BE WELL TO OUR EAST ASSOCIATED WITH THE H85
JET. THAT BEING SAID...IF WE WERE TO GET SEVERE WEATHER IT WOULD BE
ASSOCIATED WITH THE CLEAR SLOT IN THE AFTERNOON. HIRES MODELS
PREDICT A BROKEN LINE OF CONVECTION ALONG THIS INTERFACE. I THINK
THAT HAIL WOULD BE THE MAIN THREAT IF SEVERE WEATHER OCCURRED. I
ALSO THINK A BRIEF WEAK SPIN UP IS NOT OUT OF THE QUESTION.
AGAIN...I HAVE VERY LOW CONFIDENCE IN THIS OCCURRING. WILL MENTION
THE MARGINAL RISK FOR SEVERE WEATHER IN THE HWO WITH THE HAIL THREAT
FOR WEDNESDAY. ONCE THE SYSTEM MOVES OUT...THE GEM TRIES TO SNEAK
IN ANOTHER WAVE ALONG THE BOUNDARY OVERNIGHT. I DO NOT THINK THIS
WILL HAPPEN AS IT IS THE OUTLIER OF THE REST OF THE MODELS. AS SUCH
I DOWNPLAYED IT. IF IT IS RIGHT...WE COULD SEE SOME SNOW
ACCUMULATION ACROSS NW ZONES.
THURSDAY THROUGH SATURDAY...
MODELS IN GOOD AGREEMENT FOR A QUIET CHRISTMAS EVE AND CHRISTMAS DAY
ACROSS THE AREA WITH HIGH PRESSURE ENTRENCHED ACROSS THE AREA. THE
POTENTIAL EXISTS FOR SOME CLEARING AS WELL ON CHRISTMAS DAY. AFTER
CHRISTMAS DAY...INTO SATURDAY...THE GFS AND ECMWF STALL A BOUNDARY
TO OUR SOUTH. OVERRRUNING MOISTURE MAY GRAZE THE AREA WITH RAIN AND
EVEN SOME RAIN/SNOW MIX ACROSS THE FAR NORTH FRIDAY NIGHT INTO
SATURDAY. FOR THE MOST PART THE HEAVIEST PRECIP STAYS TO THE SOUTH.
PAST THIS...THE MODELS DIVERGE.
PAST SATURDAY...
WITH GUIDANCE JUMPING RUN TO RUN PAST SATURDAY IM GOING TO DISCUSS
EACH MODELS GUIDANCE AND SUGGESTED OUTCOMES AND THEN DISCUSS WHY I
WENT A COMPROMISE BETWEEN THE GFS AND ECMWF. NEEDLESS TO SAY...THE
EXTENDED FORECAST IS FULL OF BUSY WEATHER...AND IF THE GFS IS
CORRECT...WE COULD SEE AN ADDITIONAL 2 TO 4 INCHES AND POSSIBLY UP
TO 5 INCHES THROUGH THE NEXT TEN DAYS.
GFS...
THE RECENT GFS RUNS HAVE PUSHED AN EXTREMELY POTENT...NEGATIVELY
TILTED SYSTEM INTO THE AREA. THIS PULLS A DEEP LOW ACROSS CENTRAL
IOWA. WITH THE STALLED BOUNDARY TO OUR SOUTH...DEEP MOISTURE WOULD
QUICKLY SURGE INTO THE AREA. 60 DEGREE TEMPS ARE FORECAST FOR THE
FAR SE WITH THIS SYSTEM. THE WARM SECTOR...WITH BACKED
WINDS...WOULD ROLL OVER THE AREA...LIKELY LEADING TO THUNDERSTORMS
AND INCREASED RAINFALL ACROSS THE AREA. THE GFS HAS 1 TO 3+ INCHES
OF RAIN IN THIS EVENT. IF THIS WERE TO OCCUR...WE WOULD LIKELY NOT
HAVE MUCH TIME FOR WATER FROM YESTERDAYS EVENT AND WEDNESDAY EVENT
TO ROUTE THROUGH THE RIVERS...MEANING HIGHER RIVERS AND POSSIBLY
INCREASED FLOODING. THE NORTHERN EDGE OF THE CWA WOULD EXPERIENCE
A WINTRY MIX INTO SUNDAY NIGHT AND MONDAY MORNING. AT THIS TIME
HAVE A RA/SN/PL MIX. THIS SOLUTION WOULD BE THE WORST FROM A HYDRO
POINT OF VIEW. I HAVE LOW CONFIDENCE IN THIS OCCURRING.
ECMWF...
THE EURO IS MUCH SLOWER AND ACTUALLY KEEPS THE LOW TO OUR SOUTH
LONGER. THIS WOULD HELP TO ROUTE MORE WATER OUT OF THE FLOW.
EVENTUALLY ON TUESDAY...THE LOW LIFTS THROUGH THE AREA AND HAS LOWER
...LESS THAN AN INCH QPF...ALONG WITH IT. THIS WOULD BE A MUCH
BETTER SOLUTION FROM A HYDRO POINT OF VIEW. MY CONFIDENCE IS
SLIGHTLY HIGHER IN THIS SCENARIO THAN THE GFS...NONETHELESS IT IS
LOW.
THE BOTTOM LINE...
IM STRUGGLING TO DEVELOP THE CONFIDENCE TO TOTALLY ELIMINATE THE GFS
SOLUTION FROM NEXT WEEK. THE GFS HAS CONSISTENTLY DROPPED 1 TO 2
INCHES OF QPF ACROSS CENTRAL MO. A SMALL SHIFT NORTH INTO OUR AREA
IS NOT UNREASONABLE. HOWEVER...IT HAS JUMPED AROUND A LOT MORE
THAN THE EURO AS OF LATE. THIS IS WHY I AM OKAY WITH THE BLEND
THAT I HAVE. UNTIL THE MODELS AGREE ON A SOLUTION THIS WILL
CONTINUE. OBVIOUSLY THESE DIFFERENCES IN SOLUTION MEAN A MAJOR
DIFFERENCE IN POTENTIAL IMPACTS. WHILE I DONT WANT TO MINIMALIZE
THESE IMPACTS...IT IS IMPORTANT TO REMEMBER WE ARE ALMOST 7 DAYS
OUT. EXPECT CHANGES TO THE FORECAST FOR EARLY NEXT WEEK...SOME OF
THESE CHANGES COULD BE SIGNIFICANT...THAT IS THE BOTTOM LINE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1215 PM CST TUE DEC 22 2015
IFR CONDS GRADUALLY IMPROVING TO MVFR LATE THIS AFTERNOON INTO
THIS EVENING. THEN AN INTENSE STORM SYSTEM TRACKING OUT OF THE
SOUTHERN PLAINS WILL SPREAD RAIN AND IFR CONDS INTO THE AREA LATE
TONIGHT AND ON WEDNESDAY. SCATTERED THUNDERSTORMS ARE ALSO
EXPECTED MAINLY IN THE AFTERNOON. SOUTHEAST WINDS 10 TO 15 KNOTS
THROUGH THIS TAF CYCLE.
&&
.HYDROLOGY...
ISSUED AT 247 AM CST TUE DEC 22 2015
RAINFALL AMOUNTS OF A QUARTER INCH TO THREE QUARTERS OF AN INCH FELL
OVER THE PAST 24 HOURS GENERALLY SOUTH OF A LINE FROM MARENGO TO
BELLEVUE. WITH SATURATED GROUND...NEARLY ALL OF THIS RAINFALL WILL
BE RUNOFF AND HAVE ALREADY SEEN SOME LOCAL RESPONSES ON SOME OF THE
RIVERS. THIS ADDITIONAL RAINFALL WILL INCREASE THE FORECAST CRESTS A
BIT ON SOME RIVERS...AND HAS PUSHED THE FORECASTS FOR THE LOWER END
OF THE SKUNK AND DES MOINES RIVERS OVER FLOOD STAGE. ALONG THE
MISSISSIPPI...AFTER SEEING THE RIVER LEVELS FALL OR BECOME STEADY
OVER THE PAST 24 HOURS...MOST SITES WILL SEE THE RIVER BEGIN RISING
AGAIN...WITH THIS TREND CONTINUING THROUGH MUCH OF THE WEEK.
MOST FORECASTS ARE FOR THE RIVER LEVELS TO FALL BY THE END OF THIS
WEEK. HOWEVER...ADDITIONAL STORM SYSTEMS ARE LOOKING TO PASS ACROSS
THE AREA THROUGH THE NEXT WEEK WITH PRECIPITATION FALLING AS RAIN.
THE FIRST OF WHICH WILL BE WEDNESDAY. THERE IS QUITE A BIT OF
UNCERTAINTY IN HOW MUCH RAIN WILL FALL AND WHAT AREAS WILL GET HIT
YET...BUT LIKELY WILL BE ADDITIONAL RISES AND FURTHER POTENTIAL FOR
FLOODING ON SOME AREA RIVERS THROUGH THE CHRISTMAS HOLIDAY WEEKEND.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...HAASE
SYNOPSIS...MCCLURE
SHORT TERM...MCCLURE
LONG TERM...GIBBS
AVIATION...HAASE
HYDROLOGY...GIBBS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
607 AM CST TUE DEC 22 2015
...AVIATION UPDATE...
.SYNOPSIS...
ISSUED AT 337 AM CST TUE DEC 22 2015
WEAK SURFACE RIDGE IS BUILDING INTO THE AREA EARLY THIS AM.
SATELLITE AND OBS SHOW STRATUS BLANKETING THE ENTIRE AREA AND
MUCH OF THE MIDWEST... WITH THE BACK EDGE NEAR THE MISSOURI
RIVER VALLEY SHOWING LITTLE MOVEMENT HOLDING FIRM BENEATH STRONG
850 MB INVERSION. WEAK ISENTROPIC ASCENT AND WEAK CONVERGENCE
WITH SURFACE TROUGH PRODUCED PATCHY TO AREAS OF FOG AND DRIZZLE
LAST EVENING INTO THE OVERNIGHT... BUT SEEING A DIMINISHING TREND
EARLY THIS AM AS THIS LIFT MIGRATES EAST. WATER VAPOR SHOWS
UPPER LEVEL SHORTWAVE MOVING ACROSS THE UPPER MIDWEST WITHIN
SEMI-ZONAL FLOW PATTERN. MUCH STRONGER WAVE WAS NOTED OVER THE
NORTHERN ROCKIES IN LEFT EXIT REGION OF VIGOROUS UPPER LEVEL JET
NOSING FROM EASTERN PACIFIC INTO THE WESTERN CONUS. THIS SYSTEM
LOOKS TO SHIFT ACROSS THE UPPER MIDWEST ON WEDNESDAY BRINGING
OUR NEXT ROUND OF WET WEATHER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM CST TUE DEC 22 2015
MAIN CHALLENGES ARE CLOUD TRENDS AND IMPACT ON HIGHS... THEN RAIN
CHANCES LATER TONIGHT.
DONT FORESEE MUCH EROSION OF THE STRATUS THIS AM WITH SFC RIDGE
SLIDING ACROSS REGION WITH LIMITED MIXING AND STRONG 850 MB
INVERSION IN PLACE. HOWEVER... REMAINS TO BE SEEN WITH PASSAGE
OF THE MID LEVEL WAVE THIS AM IF INCREASING SUBSIDENCE IN WAKE
CAN HELP BRING ABOUT SOME EROSION AND NOTICING LAST FEW RUNS OF
HRRR DEPICT SOME DECREASE IN LOWER CLOUDS NORTH LATE AM INTO THE
PM. SATELLITE TRENDS ALSO SHOW LITTLE MOVEMENT TO BACK EDGE OF THE
STRATUS NEAR THE MISSOURI RIVER VALLEY EARLY THIS AM... AND SOME
OF THE HI-RES GUIDANCE IS PRETTY AGGRESSIVE IN ERODING THIS FROM
THE SOUTH THIS AFTERNOON INTO EASTERN IA AND WESTERN IL... BUT
NOTICING HRRR TRENDING SLOWER WITH THIS PROCESS AND WOULD SUGGEST
SOME EROSION UP TO OUR SOUTHERN CWA BUT MAINLY FURTHER SOUTH.
DO FEEL SOME EROSION OF STRATUS IS LIKELY ESPECIALLY ON THE WEST
AND SOUTH SIDE OF DECK WITHIN DEVELOPING STRONGER SOUTHERLY FLOW
AND MIXING... BUT ALSO EXPECT INCREASING HIGH CLOUDS AND WITH
THE FLOW GENERALLY SSE NOT FEELING GOOD ON PROSPECTS FOR MUCH IN
WAY OF SUNSHINE TODAY AND THUS STAYED WITH CLOUDY-MOCLDY SKY
FORECAST TODAY. AS A RESULT OF STAYING PESSIMISTIC WITH CLOUDS
LOWERED HIGHS A TOUCH AND SIDED ON COOL SIDE OF GUIDANCE BLEND
WITH RANGE AROUND 40 TO MID 40S. HOWEVER... IF NO LIFTING OR
THINNING OF STRATUS OCCURS THEN WILL BE COLDER AND MORE IN RANGE
OF MID 30S NORTH TO LOWER 40S SOUTH. ON THE OTHER SIDE OF THIS
IF WE WERE TO SEE MORE EROSION OF STRATUS THIS AFTERNOON WITH
ONSET OF GUSTY SSE WINDS AND BETTER MIXING THEN COULD EASILY SEE
HIGHS WELL INTO THE 40S TO LOWER 50S. BOTTOM LINE... AS CLOUD
TRENDS GO... SO GO TEMPS. TYPICALLY BETTER TO STAY CONSERVATIVE/
PESSIMISTIC WITH CLOUD AND TEMP TRENDS THIS TIME OF YEAR... AS
DECEMBER IS OUR CLOUDIEST MONTH.
AS FOR WINDS TODAY... SHOULD BECOME GUSTY BY AFTERNOON FROM S/SE
15-25 MPH... WITH TIGHTENING PRESSURE GRADIENT BETWEEN NORTHERN
PLAINS TO LEE SIDE CYCLONES AND GREAT LAKES HIGH PRESSURE RIDGE.
WINDS LIKELY TO REMAIN OCCASIONALLY GUSTY TONIGHT WITH CONTINUED
RAMPING UP OF LOW LEVEL JET AND LINGERING SFC PRESSURE GRADIENT.
ISENTROPIC ASCENT/WARM ADVECTION WITH STRENGTHENING LOW LEVEL JET
SHOULD FOSTER INCREASING SHOWER ACTIVITY OVERNIGHT... ESPECIALLY
WEST AND SOUTHWEST OF QUAD CITIES. CANT RULE OUT A RUMBLE OF
THUNDER ESPECIALLY FAR SOUTHWEST CWA WITHIN PLUME OF STEEP LAPSE
RATES 7-8C/KM IN 600-750 LAYER... BUT FEELING FAIRLY ISOLATED AND
HAVE LEFT OUT MENTION ATTIM.
TEMPS SHOULD DROP VERY LITTLE EARLY THIS EVENING AND PRETTY MUCH
BE STEADY TO GRADUALLY RISING TONIGHT WITH CONTINUED WARM
ADVECTION. DEPENDING ON WHAT TEMPS DO TODAY... ITS VERY POSSIBLE
TO SEE HIGHS FOR THE DAY SOME AREAS OCCUR THIS EVENING...
ESPECIALLY NORTHERN CWA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 337 AM CST TUE DEC 22 2015
MAIN FORECAST CONCERN FOR THE LONG TERM ARE THE CHANCES FOR
PRECIPITATION AND THE CHANGING GUIDANCE. GUIDANCE HAS NOT SETTLED
ON ANY SOLUTIONS PAST TOMORROW. THIS LEADS TO AN OVERALL POOR
CONFIDENCE IN THE FORECAST. MAIN ISSUE WITH THIS IS THAT SOME OF
THE MODEL SOLUTIONS SUGGEST THE POTENTIAL FOR A SIGNIFICANT RAINFALL
EVENT BOTH WEDNESDAY AND AGAIN TOWARDS THE END OF THE WEEKEND. THESE
EVENTS...IF THEY OCCUR WOULD ONLY EXASPERATE AN ALREADY ATYPICAL
DECEMBER HYDRO EVENT.
WEDNESDAY...WEDNESDAY NIGHT...
MODELS ARE IN GOOD AGREEMENT WITH THE TRACK OF THE LOW ACROSS THE
AREA. MUCH LIKE YESTERDAY...TEMPERATURES WILL BE THE 40S TO 50S
ACROSS THE CWA AND MOISTURE STREAMS INTO THE AREA. WITH PWATS WELL
ABOVE NORMAL AND APPROACHING 1 INCH ACROSS THE AREA...THE POTENTIAL
FOR MODERATE RAINFALL EXISTS. IT APPEARS THAT WE ONCE AGAIN HAVE A
THREAT FOR THUNDERSTORMS WITH THIS SYSTEM AS THE CLEAR SLOT MAKES
ITS WAY INTO THE AREA. LAPSE RATES SHOULD STEEPEN IN THE MIXED
PHASE REGION OF AN UPDRAFT...THIS INCREASES THE CHANCES FOR
THUNDER...ESPECIALLY SOUTH AND THEN EAST OF THE QC. SPC HAS THIS
AREA IN A MARGINAL RISK FOR SEVERE WEATHER ON WEDNESDAY WITH THE
SLIGHT RISK NOT FAR TO OUR EAST. MY GUT IS TELLING ME THAT THE BEST
CHANCE FOR SEVERE WILL BE WELL TO OUR EAST ASSOCIATED WITH THE H85
JET. THAT BEING SAID...IF WE WERE TO GET SEVERE WEATHER IT WOULD BE
ASSOCIATED WITH THE CLEAR SLOT IN THE AFTERNOON. HIRES MODELS
PREDICT A BROKEN LINE OF CONVECTION ALONG THIS INTERFACE. I THINK
THAT HAIL WOULD BE THE MAIN THREAT IF SEVERE WEATHER OCCURRED. I
ALSO THINK A BRIEF WEAK SPIN UP IS NOT OUT OF THE QUESTION.
AGAIN...I HAVE VERY LOW CONFIDENCE IN THIS OCCURRING. WILL MENTION
THE MARGINAL RISK FOR SEVERE WEATHER IN THE HWO WITH THE HAIL THREAT
FOR WEDNESDAY. ONCE THE SYSTEM MOVES OUT...THE GEM TRIES TO SNEAK
IN ANOTHER WAVE ALONG THE BOUNDARY OVERNIGHT. I DO NOT THINK THIS
WILL HAPPEN AS IT IS THE OUTLIER OF THE REST OF THE MODELS. AS SUCH
I DOWNPLAYED IT. IF IT IS RIGHT...WE COULD SEE SOME SNOW
ACCUMULATION ACROSS NW ZONES.
THURSDAY THROUGH SATURDAY...
MODELS IN GOOD AGREEMENT FOR A QUIET CHRISTMAS EVE AND CHRISTMAS DAY
ACROSS THE AREA WITH HIGH PRESSURE ENTRENCHED ACROSS THE AREA. THE
POTENTIAL EXISTS FOR SOME CLEARING AS WELL ON CHRISTMAS DAY. AFTER
CHRISTMAS DAY...INTO SATURDAY...THE GFS AND ECMWF STALL A BOUNDARY
TO OUR SOUTH. OVERRRUNING MOISTURE MAY GRAZE THE AREA WITH RAIN AND
EVEN SOME RAIN/SNOW MIX ACROSS THE FAR NORTH FRIDAY NIGHT INTO
SATURDAY. FOR THE MOST PART THE HEAVIEST PRECIP STAYS TO THE SOUTH.
PAST THIS...THE MODELS DIVERGE.
PAST SATURDAY...
WITH GUIDANCE JUMPING RUN TO RUN PAST SATURDAY IM GOING TO DISCUSS
EACH MODELS GUIDANCE AND SUGGESTED OUTCOMES AND THEN DISCUSS WHY I
WENT A COMPROMISE BETWEEN THE GFS AND ECMWF. NEEDLESS TO SAY...THE
EXTENDED FORECAST IS FULL OF BUSY WEATHER...AND IF THE GFS IS
CORRECT...WE COULD SEE AN ADDITIONAL 2 TO 4 INCHES AND POSSIBLY UP
TO 5 INCHES THROUGH THE NEXT TEN DAYS.
GFS...
THE RECENT GFS RUNS HAVE PUSHED AN EXTREMELY POTENT...NEGATIVELY
TILTED SYSTEM INTO THE AREA. THIS PULLS A DEEP LOW ACROSS CENTRAL
IOWA. WITH THE STALLED BOUNDARY TO OUR SOUTH...DEEP MOISTURE WOULD
QUICKLY SURGE INTO THE AREA. 60 DEGREE TEMPS ARE FORECAST FOR THE
FAR SE WITH THIS SYSTEM. THE WARM SECTOR...WITH BACKED
WINDS...WOULD ROLL OVER THE AREA...LIKELY LEADING TO THUNDERSTORMS
AND INCREASED RAINFALL ACROSS THE AREA. THE GFS HAS 1 TO 3+ INCHES
OF RAIN IN THIS EVENT. IF THIS WERE TO OCCUR...WE WOULD LIKELY NOT
HAVE MUCH TIME FOR WATER FROM YESTERDAYS EVENT AND WEDNESDAY EVENT
TO ROUTE THROUGH THE RIVERS...MEANING HIGHER RIVERS AND POSSIBLY
INCREASED FLOODING. THE NORTHERN EDGE OF THE CWA WOULD EXPERIENCE
A WINTRY MIX INTO SUNDAY NIGHT AND MONDAY MORNING. AT THIS TIME
HAVE A RA/SN/PL MIX. THIS SOLUTION WOULD BE THE WORST FROM A HYDRO
POINT OF VIEW. I HAVE LOW CONFIDENCE IN THIS OCCURRING.
ECMWF...
THE EURO IS MUCH SLOWER AND ACTUALLY KEEPS THE LOW TO OUR SOUTH
LONGER. THIS WOULD HELP TO ROUTE MORE WATER OUT OF THE FLOW.
EVENTUALLY ON TUESDAY...THE LOW LIFTS THROUGH THE AREA AND HAS LOWER
...LESS THAN AN INCH QPF...ALONG WITH IT. THIS WOULD BE A MUCH
BETTER SOLUTION FROM A HYDRO POINT OF VIEW. MY CONFIDENCE IS
SLIGHTLY HIGHER IN THIS SCENARIO THAN THE GFS...NONETHELESS IT IS
LOW.
THE BOTTOM LINE...
IM STRUGGLING TO DEVELOP THE CONFIDENCE TO TOTALLY ELIMINATE THE GFS
SOLUTION FROM NEXT WEEK. THE GFS HAS CONSISTENTLY DROPPED 1 TO 2
INCHES OF QPF ACROSS CENTRAL MO. A SMALL SHIFT NORTH INTO OUR AREA
IS NOT UNREASONABLE. HOWEVER...IT HAS JUMPED AROUND A LOT MORE
THAN THE EURO AS OF LATE. THIS IS WHY I AM OKAY WITH THE BLEND
THAT I HAVE. UNTIL THE MODELS AGREE ON A SOLUTION THIS WILL
CONTINUE. OBVIOUSLY THESE DIFFERENCES IN SOLUTION MEAN A MAJOR
DIFFERENCE IN POTENTIAL IMPACTS. WHILE I DONT WANT TO MINIMALIZE
THESE IMPACTS...IT IS IMPORTANT TO REMEMBER WE ARE ALMOST 7 DAYS
OUT. EXPECT CHANGES TO THE FORECAST FOR EARLY NEXT WEEK...SOME OF
THESE CHANGES COULD BE SIGNIFICANT...THAT IS THE BOTTOM LINE.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 544 AM CST TUE DEC 22 2015
STRATUS WITH MAINLY IFR CIGS BLANKETING THE REGION EARLY THIS AM.
BELIEVE STRATUS WILL REMAIN IN PLACE THROUGH 18Z WITH SFC RIDGE
AND ATTENDANT WEAK MIXING ALONG WITH STRONG 850 MB INVERSION...
WITH GRADUAL LIFTING OF CIGS FROM IFR TO LOWER MVFR THROUGH 18Z.
GENERALLY LOWER MVFR CIGS ANTICIPATED THIS AFTERNOON WITH SOME
EROSION OF STRATUS AND IMPROVEMENT TO VFR POSSIBLE... WITH BRL
GENERALLY SHOWN TO HAVE BEST CHANCE AT VFR THIS AFTN/EARLY EVE
ALTHOUGH CANT BE RULED OUT ELSEWHERE GIVEN INCREASING WINDS AND
MIXING... BUT CONFIDENCE TOO LOW AND LEFT OTHER SITES
(DBQ/CID/MLI) IN LOWER MVFR THIS AFTN. ALL SITES THEN TRANSITION
BACK DOWN TO IFR TONIGHT AHEAD OF NEXT STORM SYSTEM. SOME SHOWERS
LIKELY TO DEVELOP LATE TONIGHT ESPECIALLY SOUTHEAST IA AND HAVE
VCSH WORDING FOR NOW AT BRL. POTENTIAL ALSO FOR LOW LEVEL WIND
SHEAR LATE TONIGHT INTO MID AM WED... BUT WITH POTENTIAL GUSTY SFC
WINDS IN TIGHTENING PRESSURE GRADIENT HAVE LEFT OUT MENTION ATTIM.
WINDS SHIFT FROM W/SW TO SE BY THIS AFTERNOON INTO TONIGHT AND
INCREASE TO 10-15 KTS WITH OCCASIONAL GUSTS.
&&
.HYDROLOGY...
ISSUED AT 247 AM CST TUE DEC 22 2015
RAINFALL AMOUNTS OF A QUARTER INCH TO THREE QUARTERS OF AN INCH FELL
OVER THE PAST 24 HOURS GENERALLY SOUTH OF A LINE FROM MARENGO TO
BELLEVUE. WITH SATURATED GROUND...NEARLY ALL OF THIS RAINFALL WILL
BE RUNOFF AND HAVE ALREADY SEEN SOME LOCAL RESPONSES ON SOME OF THE
RIVERS. THIS ADDITIONAL RAINFALL WILL INCREASE THE FORECAST CRESTS A
BIT ON SOME RIVERS...AND HAS PUSHED THE FORECASTS FOR THE LOWER END
OF THE SKUNK AND DES MOINES RIVERS OVER FLOOD STAGE. ALONG THE
MISSISSIPPI...AFTER SEEING THE RIVER LEVELS FALL OR BECOME STEADY
OVER THE PAST 24 HOURS...MOST SITES WILL SEE THE RIVER BEGIN RISING
AGAIN...WITH THIS TREND CONTINUING THROUGH MUCH OF THE WEEK.
MOST FORECASTS ARE FOR THE RIVER LEVELS TO FALL BY THE END OF THIS
WEEK. HOWEVER...ADDITIONAL STORM SYSTEMS ARE LOOKING TO PASS ACROSS
THE AREA THROUGH THE NEXT WEEK WITH PRECIPITATION FALLING AS RAIN.
THE FIRST OF WHICH WILL BE WEDNESDAY. THERE IS QUITE A BIT OF
UNCERTAINTY IN HOW MUCH RAIN WILL FALL AND WHAT AREAS WILL GET HIT
YET...BUT LIKELY WILL BE ADDITIONAL RISES AND FURTHER POTENTIAL FOR
FLOODING ON SOME AREA RIVERS THROUGH THE CHRISTMAS HOLIDAY WEEKEND.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...MCCLURE
SHORT TERM...MCCLURE
LONG TERM...GIBBS
AVIATION...05
HYDROLOGY...GIBBS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
340 AM CST TUE DEC 22 2015
.SYNOPSIS...
ISSUED AT 337 AM CST TUE DEC 22 2015
WEAK SURFACE RIDGE IS BUILDING INTO THE AREA EARLY THIS AM.
SATELLITE AND OBS SHOW STRATUS BLANKETING THE ENTIRE AREA AND
MUCH OF THE MIDWEST... WITH THE BACK EDGE NEAR THE MISSOURI
RIVER VALLEY SHOWING LITTLE MOVEMENT HOLDING FIRM BENEATH STRONG
850 MB INVERSION. WEAK ISENTROPIC ASCENT AND WEAK CONVERGENCE
WITH SURFACE TROUGH PRODUCED PATCHY TO AREAS OF FOG AND DRIZZLE
LAST EVENING INTO THE OVERNIGHT... BUT SEEING A DIMINISHING TREND
EARLY THIS AM AS THIS LIFT MIGRATES EAST. WATER VAPOR SHOWS
UPPER LEVEL SHORTWAVE MOVING ACROSS THE UPPER MIDWEST WITHIN
SEMI-ZONAL FLOW PATTERN. MUCH STRONGER WAVE WAS NOTED OVER THE
NORTHERN ROCKIES IN LEFT EXIT REGION OF VIGOROUS UPPER LEVEL JET
NOSING FROM EASTERN PACIFIC INTO THE WESTERN CONUS. THIS SYSTEM
LOOKS TO SHIFT ACROSS THE UPPER MIDWEST ON WEDNESDAY BRINGING
OUR NEXT ROUND OF WET WEATHER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 337 AM CST TUE DEC 22 2015
MAIN CHALLENGES ARE CLOUD TRENDS AND IMPACT ON HIGHS... THEN RAIN
CHANCES LATER TONIGHT.
DONT FORESEE MUCH EROSION OF THE STRATUS THIS AM WITH SFC RIDGE
SLIDING ACROSS REGION WITH LIMITED MIXING AND STRONG 850 MB
INVERSION IN PLACE. HOWEVER... REMAINS TO BE SEEN WITH PASSAGE
OF THE MID LEVEL WAVE THIS AM IF INCREASING SUBSIDENCE IN WAKE
CAN HELP BRING ABOUT SOME EROSION AND NOTICING LAST FEW RUNS OF
HRRR DEPICT SOME DECREASE IN LOWER CLOUDS NORTH LATE AM INTO THE
PM. SATELLITE TRENDS ALSO SHOW LITTLE MOVEMENT TO BACK EDGE OF THE
STRATUS NEAR THE MISSOURI RIVER VALLEY EARLY THIS AM... AND SOME
OF THE HI-RES GUIDANCE IS PRETTY AGGRESSIVE IN ERODING THIS FROM
THE SOUTH THIS AFTERNOON INTO EASTERN IA AND WESTERN IL... BUT
NOTICING HRRR TRENDING SLOWER WITH THIS PROCESS AND WOULD SUGGEST
SOME EROSION UP TO OUR SOUTHERN CWA BUT MAINLY FURTHER SOUTH.
DO FEEL SOME EROSION OF STRATUS IS LIKELY ESPECIALLY ON THE WEST
AND SOUTH SIDE OF DECK WITHIN DEVELOPING STRONGER SOUTHERLY FLOW
AND MIXING... BUT ALSO EXPECT INCREASING HIGH CLOUDS AND WITH
THE FLOW GENERALLY SSE NOT FEELING GOOD ON PROSPECTS FOR MUCH IN
WAY OF SUNSHINE TODAY AND THUS STAYED WITH CLOUDY-MOCLDY SKY
FORECAST TODAY. AS A RESULT OF STAYING PESSIMISTIC WITH CLOUDS
LOWERED HIGHS A TOUCH AND SIDED ON COOL SIDE OF GUIDANCE BLEND
WITH RANGE AROUND 40 TO MID 40S. HOWEVER... IF NO LIFTING OR
THINNING OF STRATUS OCCURS THEN WILL BE COLDER AND MORE IN RANGE
OF MID 30S NORTH TO LOWER 40S SOUTH. ON THE OTHER SIDE OF THIS
IF WE WERE TO SEE MORE EROSION OF STRATUS THIS AFTERNOON WITH
ONSET OF GUSTY SSE WINDS AND BETTER MIXING THEN COULD EASILY SEE
HIGHS WELL INTO THE 40S TO LOWER 50S. BOTTOM LINE... AS CLOUD
TRENDS GO... SO GO TEMPS. TYPICALLY BETTER TO STAY CONSERVATIVE/
PESSIMISTIC WITH CLOUD AND TEMP TRENDS THIS TIME OF YEAR... AS
DECEMBER IS OUR CLOUDIEST MONTH.
AS FOR WINDS TODAY... SHOULD BECOME GUSTY BY AFTERNOON FROM S/SE
15-25 MPH... WITH TIGHTENING PRESSURE GRADIENT BETWEEN NORTHERN
PLAINS TO LEE SIDE CYCLONES AND GREAT LAKES HIGH PRESSURE RIDGE.
WINDS LIKELY TO REMAIN OCCASIONALLY GUSTY TONIGHT WITH CONTINUED
RAMPING UP OF LOW LEVEL JET AND LINGERING SFC PRESSURE GRADIENT.
ISENTROPIC ASCENT/WARM ADVECTION WITH STRENGTHENING LOW LEVEL JET
SHOULD FOSTER INCREASING SHOWER ACTIVITY OVERNIGHT... ESPECIALLY
WEST AND SOUTHWEST OF QUAD CITIES. CANT RULE OUT A RUMBLE OF
THUNDER ESPECIALLY FAR SOUTHWEST CWA WITHIN PLUME OF STEEP LAPSE
RATES 7-8C/KM IN 600-750 LAYER... BUT FEELING FAIRLY ISOLATED AND
HAVE LEFT OUT MENTION ATTIM.
TEMPS SHOULD DROP VERY LITTLE EARLY THIS EVENING AND PRETTY MUCH
BE STEADY TO GRADUALLY RISING TONIGHT WITH CONTINUED WARM
ADVECTION. DEPENDING ON WHAT TEMPS DO TODAY... ITS VERY POSSIBLE
TO SEE HIGHS FOR THE DAY SOME AREAS OCCUR THIS EVENING...
ESPECIALLY NORTHERN CWA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 337 AM CST TUE DEC 22 2015
MAIN FORECAST CONCERN FOR THE LONG TERM ARE THE CHANCES FOR
PRECIPITATION AND THE CHANGING GUIDANCE. GUIDANCE HAS NOT SETTLED
ON ANY SOLUTIONS PAST TOMORROW. THIS LEADS TO AN OVERALL POOR
CONFIDENCE IN THE FORECAST. MAIN ISSUE WITH THIS IS THAT SOME OF
THE MODEL SOLUTIONS SUGGEST THE POTENTIAL FOR A SIGNIFICANT RAINFALL
EVENT BOTH WEDNESDAY AND AGAIN TOWARDS THE END OF THE WEEKEND. THESE
EVENTS...IF THEY OCCUR WOULD ONLY EXASPERATE AN ALREADY ATYPICAL
DECEMBER HYDRO EVENT.
WEDNESDAY...WEDNESDAY NIGHT...
MODELS ARE IN GOOD AGREEMENT WITH THE TRACK OF THE LOW ACROSS THE
AREA. MUCH LIKE YESTERDAY...TEMPERATURES WILL BE THE 40S TO 50S
ACROSS THE CWA AND MOISTURE STREAMS INTO THE AREA. WITH PWATS WELL
ABOVE NORMAL AND APPROACHING 1 INCH ACROSS THE AREA...THE POTENTIAL
FOR MODERATE RAINFALL EXISTS. IT APPEARS THAT WE ONCE AGAIN HAVE A
THREAT FOR THUNDERSTORMS WITH THIS SYSTEM AS THE CLEAR SLOT MAKES
ITS WAY INTO THE AREA. LAPSE RATES SHOULD STEEPEN IN THE MIXED
PHASE REGION OF AN UPDRAFT...THIS INCREASES THE CHANCES FOR
THUNDER...ESPECIALLY SOUTH AND THEN EAST OF THE QC. SPC HAS THIS
AREA IN A MARGINAL RISK FOR SEVERE WEATHER ON WEDNESDAY WITH THE
SLIGHT RISK NOT FAR TO OUR EAST. MY GUT IS TELLING ME THAT THE BEST
CHANCE FOR SEVERE WILL BE WELL TO OUR EAST ASSOCIATED WITH THE H85
JET. THAT BEING SAID...IF WE WERE TO GET SEVERE WEATHER IT WOULD BE
ASSOCIATED WITH THE CLEAR SLOT IN THE AFTERNOON. HIRES MODELS
PREDICT A BROKEN LINE OF CONVECTION ALONG THIS INTERFACE. I THINK
THAT HAIL WOULD BE THE MAIN THREAT IF SEVERE WEATHER OCCURRED. I
ALSO THINK A BRIEF WEAK SPIN UP IS NOT OUT OF THE QUESTION.
AGAIN...I HAVE VERY LOW CONFIDENCE IN THIS OCCURRING. WILL MENTION
THE MARGINAL RISK FOR SEVERE WEATHER IN THE HWO WITH THE HAIL THREAT
FOR WEDNESDAY. ONCE THE SYSTEM MOVES OUT...THE GEM TRIES TO SNEAK
IN ANOTHER WAVE ALONG THE BOUNDARY OVERNIGHT. I DO NOT THINK THIS
WILL HAPPEN AS IT IS THE OUTLIER OF THE REST OF THE MODELS. AS SUCH
I DOWNPLAYED IT. IF IT IS RIGHT...WE COULD SEE SOME SNOW
ACCUMULATION ACROSS NW ZONES.
THURSDAY THROUGH SATURDAY...
MODELS IN GOOD AGREEMENT FOR A QUIET CHRISTMAS EVE AND CHRISTMAS DAY
ACROSS THE AREA WITH HIGH PRESSURE ENTRENCHED ACROSS THE AREA. THE
POTENTIAL EXISTS FOR SOME CLEARING AS WELL ON CHRISTMAS DAY. AFTER
CHRISTMAS DAY...INTO SATURDAY...THE GFS AND ECMWF STALL A BOUNDARY
TO OUR SOUTH. OVERRRUNING MOISTURE MAY GRAZE THE AREA WITH RAIN AND
EVEN SOME RAIN/SNOW MIX ACROSS THE FAR NORTH FRIDAY NIGHT INTO
SATURDAY. FOR THE MOST PART THE HEAVIEST PRECIP STAYS TO THE SOUTH.
PAST THIS...THE MODELS DIVERGE.
PAST SATURDAY...
WITH GUIDANCE JUMPING RUN TO RUN PAST SATURDAY IM GOING TO DISCUSS
EACH MODELS GUIDANCE AND SUGGESTED OUTCOMES AND THEN DISCUSS WHY I
WENT A COMPROMISE BETWEEN THE GFS AND ECMWF. NEEDLESS TO SAY...THE
EXTENDED FORECAST IS FULL OF BUSY WEATHER...AND IF THE GFS IS
CORRECT...WE COULD SEE AN ADDITIONAL 2 TO 4 INCHES AND POSSIBLY UP
TO 5 INCHES THROUGH THE NEXT TEN DAYS.
GFS...
THE RECENT GFS RUNS HAVE PUSHED AN EXTREMELY POTENT...NEGATIVELY
TILTED SYSTEM INTO THE AREA. THIS PULLS A DEEP LOW ACROSS CENTRAL
IOWA. WITH THE STALLED BOUNDARY TO OUR SOUTH...DEEP MOISTURE WOULD
QUICKLY SURGE INTO THE AREA. 60 DEGREE TEMPS ARE FORECAST FOR THE
FAR SE WITH THIS SYSTEM. THE WARM SECTOR...WITH BACKED
WINDS...WOULD ROLL OVER THE AREA...LIKELY LEADING TO THUNDERSTORMS
AND INCREASED RAINFALL ACROSS THE AREA. THE GFS HAS 1 TO 3+ INCHES
OF RAIN IN THIS EVENT. IF THIS WERE TO OCCUR...WE WOULD LIKELY NOT
HAVE MUCH TIME FOR WATER FROM YESTERDAYS EVENT AND WEDNESDAY EVENT
TO ROUTE THROUGH THE RIVERS...MEANING HIGHER RIVERS AND POSSIBLY
INCREASED FLOODING. THE NORTHERN EDGE OF THE CWA WOULD EXPERIENCE
A WINTRY MIX INTO SUNDAY NIGHT AND MONDAY MORNING. AT THIS TIME
HAVE A RA/SN/PL MIX. THIS SOLUTION WOULD BE THE WORST FROM A HYDRO
POINT OF VIEW. I HAVE LOW CONFIDENCE IN THIS OCCURRING.
ECMWF...
THE EURO IS MUCH SLOWER AND ACTUALLY KEEPS THE LOW TO OUR SOUTH
LONGER. THIS WOULD HELP TO ROUTE MORE WATER OUT OF THE FLOW.
EVENTUALLY ON TUESDAY...THE LOW LIFTS THROUGH THE AREA AND HAS LOWER
...LESS THAN AN INCH QPF...ALONG WITH IT. THIS WOULD BE A MUCH
BETTER SOLUTION FROM A HYDRO POINT OF VIEW. MY CONFIDENCE IS
SLIGHTLY HIGHER IN THIS SCENARIO THAN THE GFS...NONETHELESS IT IS
LOW.
THE BOTTOM LINE...
IM STRUGGLING TO DEVELOP THE CONFIDENCE TO TOTALLY ELIMINATE THE GFS
SOLUTION FROM NEXT WEEK. THE GFS HAS CONSISTENTLY DROPPED 1 TO 2
INCHES OF QPF ACROSS CENTRAL MO. A SMALL SHIFT NORTH INTO OUR AREA
IS NOT UNREASONABLE. HOWEVER...IT HAS JUMPED AROUND A LOT MORE
THAN THE EURO AS OF LATE. THIS IS WHY I AM OKAY WITH THE BLEND
THAT I HAVE. UNTIL THE MODELS AGREE ON A SOLUTION THIS WILL
CONTINUE. OBVIOUSLY THESE DIFFERENCES IN SOLUTION MEAN A MAJOR
DIFFERENCE IN POTENTIAL IMPACTS. WHILE I DONT WANT TO MINIMALIZE
THESE IMPACTS...IT IS IMPORTANT TO REMEMBER WE ARE ALMOST 7 DAYS
OUT. EXPECT CHANGES TO THE FORECAST FOR EARLY NEXT WEEK...SOME OF
THESE CHANGES COULD BE SIGNIFICANT...THAT IS THE BOTTOM LINE.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1134 PM CST MON DEC 21 2015
OPTED FOR A SLOWER CLEARING TREND FOR 06Z TAF ISSUANCE BASED
MAINLY ON EVENING TRENDS OF ENTRENCHED STRATUS SHIELD. LOWEST
VISIBILITIES AND CEILINGS WILL CONTINUE AT KDBQ...AND CEILINGS
EXPECTED TO REMAIN IN PLACE THERE THROUGH TAF PERIOD. HAVE TIMED
PARTIAL CLEARING FROM 17Z TO 21Z...BEGINNING FIRST AT KBRL.
&&
.HYDROLOGY...
ISSUED AT 247 AM CST TUE DEC 22 2015
RAINFALL AMOUNTS OF A QUARTER INCH TO THREE QUARTERS OF AN INCH FELL
OVER THE PAST 24 HOURS GENERALLY SOUTH OF A LINE FROM MARENGO TO
BELLEVUE. WITH SATURATED GROUND...NEARLY ALL OF THIS RAINFALL WILL
BE RUNOFF AND HAVE ALREADY SEEN SOME LOCAL RESPONSES ON SOME OF THE
RIVERS. THIS ADDITIONAL RAINFALL WILL INCREASE THE FORECAST CRESTS A
BIT ON SOME RIVERS...AND HAS PUSHED THE FORECASTS FOR THE LOWER END
OF THE SKUNK AND DES MOINES RIVERS OVER FLOOD STAGE. ALONG THE
MISSISSIPPI...AFTER SEEING THE RIVER LEVELS FALL OR BECOME STEADY
OVER THE PAST 24 HOURS...MOST SITES WILL SEE THE RIVER BEGIN RISING
AGAIN...WITH THIS TREND CONTINUING THROUGH MUCH OF THE WEEK.
MOST FORECASTS ARE FOR THE RIVER LEVELS TO FALL BY THE END OF THIS
WEEK. HOWEVER...ADDITIONAL STORM SYSTEMS ARE LOOKING TO PASS ACROSS
THE AREA THROUGH THE NEXT WEEK WITH PRECIPITATION FALLING AS RAIN.
THE FIRST OF WHICH WILL BE WEDNESDAY. THERE IS QUITE A BIT OF
UNCERTAINTY IN HOW MUCH RAIN WILL FALL AND WHAT AREAS WILL GET HIT
YET...BUT LIKELY WILL BE ADDITIONAL RISES AND FURTHER POTENTIAL FOR
FLOODING ON SOME AREA RIVERS THROUGH THE CHRISTMAS HOLIDAY WEEKEND.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...MCCLURE
SHORT TERM...MCCLURE
LONG TERM...GIBBS
AVIATION...RP KINNEY
HYDROLOGY...GIBBS
AREA FORECAST DISCUSSION
NWS JACKSON KY
101 AM EST TUE DEC 22 2015
.UPDATE...
ISSUED AT 101 AM EST TUE DEC 22 2015
WIDESPREAD LIGHT RAIN CONTINUES TO PUSH EAST ACROSS MUCH OF THE
AREA. THIS RAIN WILL QUICKLY PUSH EAST IN THE NEXT 2 TO 4 HOURS
WITH A BRIEF LULL PUSHING IN FROM THE WEST. HOWEVER...A LINE OF
SHOWERS AND EMBEDDED THUNDERSTORMS HAS DEVELOPED OUT WEST TOWARDS
BOWLING GREEN NORTH TO JUST WEST OF FRANKFORT. HRRR HAS THIS LINE
DEPICTED WELL IN THE LATEST FEW RUNS AND BRING THIS ACTIVITY UP
ACROSS THE BLUEGRASS COUNTIES SHORTLY AFTER 09Z. WE`LL HAVE TO
WATCH THIS AS WE MAY NEED TO TOSS IN SOME THUNDER FOR OUR NORTHERN
COUNTIES. NEXT UPDATE SHOULD HAVE A BETTER HANDLE ON THIS
POTENTIAL. HI-RES MODELS DO SHOW SOME WEAKENING IN THE NEXT FEW
HOURS...SO WE`LL SEE IF THAT MATERIALIZES. REGARDLESS...WE SHOULD
SEE A SECOND SURGE OF RAIN TOWARDS DAYBREAK...ESPECIALLY FOR AREAS
ALONG OR NORTH OF THE MOUNTAIN PARKWAY. FARTHER SOUTH...ACTIVITY
WILL LIKELY BE MORE ISOLATED OR SCATTERED AS THIS ACTIVITY PUSHES
IN AROUND DAYBREAK. LOOKS LIKE THE BULK OF TUESDAY SHOULD BE RAIN
FREE FOR MOST OF US WITH A JUST A FEW ISOLATED SHOWERS HANGING ON
ACROSS SOUTHEAST KENTUCKY THROUGH THE DAY. UPDATED FORECAST HAS
ALREADY BEEN SENT.
UPDATE ISSUED AT 929 PM EST MON DEC 21 2015
RAIN CONTINUES TO INCREASE IN COVERAGE AS IT MAKES ITS WAY INTO
EASTERN KENTUCKY. DECIDED TO INCREASE THE POPS ACROSS EASTERN KY
TO ALL NUMEROUS OR DEFINITE THROUGH THE REMAINDER OF THE EVENING.
IT SEEMS AS THOUGH THUNDER HAS CEASED ACROSS THE OHIO VALLEY...BUT
DID LEAVE IN ONE HOUR OF ISOLATED THUNDER IN THE AREA OF HIGHEST
POPS...JUST IN CASE WE HEAR ONE ROGUE RUMBLE OF THUNDER IN THE
HEAVIEST SHOWERS. ALSO LOOKED AT RADAR TRENDS AND NEW MODEL
GUIDANCE TO EXTRAPOLATE THE RAIN ACROSS THE REGION THROUGH THE
REMAINDER OF THE NIGHT...EXITING DURING TOMORROW MORNING.
ALSO...MADE SURE THE NEAR TERM FORECAST FOR TEMPS...DEW
POINTS...AND WINDS WERE REFLECTING THE ONGOING CONDITIONS. ALL
UPDATES WERE PUBLISHED AND SENT TO NDFD/WEB. A NEW ZONE FORECAST
PACKAGE WAS ALSO SENT OUT AS WELL TO REFLECT THESE CHANGES.
UPDATE ISSUED AT 743 PM EST MON DEC 21 2015
COVERAGE OF SHOWERS IS INCREASING AT A FASTER RATE THAN WAS
PREVIOUSLY FORECAST...SO WENT AHEAD AND INCREASED POPS ACROSS THE
CWA THROUGH THE EVENING. STILL LOOKING AT HEAVIEST SHOWERS TO
BEGIN MOVING INTO THE REGION OVER THE NEXT SEVERAL HOURS AND
CONTINUING THROUGH THE OVERNIGHT. THERE IS SOME THUNDER ONGOING
ACROSS SOUTH CENTRAL KY...SO WILL CONTINUE TO MONITOR AS IT NEARS
THE JKL CWA TO MAKE SURE THUNDER DOES NOT NEED TO BE ADDED INTO
OUR FORECAST AS WELL. OTHER UPDATES INCLUDED CHANGING THE WEATHER
FROM PROBABILITY TO COVERAGE...SINCE THERE IS ONGOING RAIN AND
ONLY CHANCE WORDING. CARRIED THE COVERAGE WORDING THROUGH THE DAY
TOMORROW AS WELL. ALSO...LOADED THE LATEST OBSERVATIONS FOR
TEMPS...DEW POINTS...AND WINDS INTO THE NEAR TERM FORECAST TO MAKE
SURE THE GRIDS REFLECTED THE ONGOING CONDITIONS. ALL CHANGES WERE
PUBLISHED AND SENT TO NDFD. A NEW FORECAST PACKAGE WAS ALSO SENT
OUT TO REFLECT THE ABOVE CHANGE.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 340 PM EST MON DEC 21 2015
OUR REGION IS IN A BROAD AREA OF WARM/MOIST ADVECTION OFF THE GULF
OF MEXICO WITH ROUNDS OF SHOWERS. ONE ROUND MOVED THROUGH THIS
MORNING...AND ANOTHER IS SLOWLY MAKING ITS WAY SE ACROSS THE
FORECAST AREA THIS AFTERNOON. THESE SHOWERS HAVE SHOWN AN OVERALL
VERY SLOW DECLINE AS SHORTWAVE ENERGY WHICH ENHANCED THEM EARLIER
RACES AWAY TO THE NE. ANOTHER SHORTWAVE TROUGH OVER THE MIDDLE OF
THE NATION IS INTERACTING WITH THE WARM/MOIST FLOW OFF THE GULF TO
CAUSE SHOWERS AND THUNDERSTORMS OVER THE LOWER MISSISSIPPI VALLEY
THIS AFTERNOON. MODELS SHOW THIS AREA OF PRECIP QUICKLY EXPANDING
NE LATE TODAY AND TONIGHT AS THE SHORTWAVE AND A SURFACE COLD
FRONT APPROACH. THIS WILL BRING SHOWERS TO THE JKL FORECAST AREA
TONIGHT. MOST OF THE PRECIP SHOULD BE ON THE WAY OUT TO THE NE
EARLY TUESDAY MORNING AS THE SHORTWAVE DEPARTS. THE COLD FRONT IS
EXPECTED TO STALL AS IT REACHES THE JKL FORECAST AREA...AND NO
SIGNIFICANT CHANGE IN OUR UNSEASONABLY WARM SURFACE AIR MASS
SHOULD OCCUR. ANOTHER MID/UPPER LEVEL IMPULSE WILL SUPPORT AN
EXPANDING SURFACE LOW PRESSURE SYSTEM OVER THE MIDDLE OF THE CONUS
ON TUESDAY AND TUESDAY NIGHT. THIS WILL STRENGTHEN LOW LEVEL FLOW
OFF THE GULF OF MEXICO AND SEND THE SURFACE BOUNDARY BACK NORTH.
MEANWHILE... ANOTHER UPPER LEVEL IMPULSE...CURRENTLY OVER NORTHERN
MEXICO...IS SHOWN BY ALL MODELS TO MOVE RAPIDLY THROUGH THE FLOW
ALOFT TO PASS NE OVER THE SE CONUS ON TUESDAY NIGHT. THIS SHOULD
BRING YET ANOTHER ROUND OF SHOWERS FOR THE JKL FORECAST
AREA...ESPECIALLY IN OUR SE COUNTIES.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 347 PM EST MON DEC 21 2015
THE EXTENDED PORTION OF THE FORECAST BEGINS ON WEDNESDAY WITH AN
ACTIVE UPPER LEVEL PATTERN IN PLACE. A DEEP TROUGH SLOWLY MOVING
ACROSS THE MS VALLEY AND INTO THE GREAT LAKES WILL BRING SEVERAL
STRONG SHORT WAVES TRACKING NORTHEAST THROUGH THE OH VALLEY. IN
FACT...A STRONG RIDGE OVER THE ATLANTIC WILL KEEP THE LONG WAVE
TROUGH OVER THE CENTRAL CONUS WITH THE LEE SIDE OVER THE APPALACHIAN
RANGE THROUGH THE ENTIRE EXTENDED.
AT THE SURFACE...SOUTHERLY FLOW WILL BE IN PLACE ACROSS KENTUCKY AS
ANOTHER LOW DEVELOPS IN THE PLAINS AND TRACKS NORTHEAST INTO THE
MIDWEST AND GREAT LAKES REGION WITH A WARM FRONT SHIFTING NORTH
AND POSITIONING OVER THE GREAT LAKES AS WELL PUTTING EASTERN
KENTUCKY IN THE WARM SECTOR IN A VERY UNSEASONABLY WARM AND MOIST
PATTERN FOR DECEMBER. A PREFRONTAL WAVE AHEAD OF THE MAIN TROUGH
WILL KEEP ENOUGH LIFT IN PLACE FOR ONGOING SHOWERS THROUGH THE
DAY ON WEDNESDAY BEFORE FRONTAL PRECIP ARRIVES LATE WEDNESDAY
AFTERNOON AND INTO THE EVENING. DECENT FORCING AND ELEVATED INSTABILITY
WITH THIS FEATURE WILL BE ENOUGH FOR THUNDERSTORM DEVELOPMENT AS
WELL AS A FEW MARGINALLY STRONG STORMS. DETAILS ARE A BIT UNCLEAR
AT THIS POINT BUT THE AMOUNT OF SHEAR AVAILABLE WILL POSE SOME
MONITORING.
THE FRONT MOVES THROUGH BUT STALLS OVER THE APPALACHIAN RANGE BY
LATE THURSDAY WITH CONTINUED RAINFALL ACROSS THE AREA. THIS RESULT
IN A BRIEF REPRIEVE IN THE PRECIP INTO THURSDAY NIGHT BEFORE
YET ANOTHER WAVE TRACKS ALONG THE FRONT INTO FRIDAY BRINGING
ANOTHER ROUND OF RAINFALL TO THE AREA. LOW PRESSURE DEVELOPS
ALONG THE LOWER MS VALLEY AND TRACKS NORTHEAST BRINGING ANOTHER
WARM FRONT NORTH THROUGH KENTUCKY FOLLOWED BY ANOTHER ROUND OF
WARM AND WET WEATHER THROUGH THE AREA FRIDAY AND INTO SATURDAY.
AS THE MENTIONED SURFACE LOW DEVELOPS OVER THE LOWER MS
VALLEY...MODELS HINT AT A STRONG UPPER LEVEL CLOSED LOW EJECTING
OUT OF THE 4 CORNERS REGION INTO THE SOUTHERN PLAINS FURTHER
DEVELOPING A STRONG FRONTAL SYSTEM OVER THE MS VALLEY HEADING
INTO SUNDAY AND INTO THE NEW WEEK.
WHILE MODELS DIVERGE INTO THE EXTENDED...THE OVERALL TREND INTO THE
EXTENDED IS RECORD WARMTH FOLLOWED BY PROLONGED WET WEATHER.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 101 AM EST TUE DEC 22 2015
WHILE CIGS HAVE GONE VFR ACROSS EASTERN KENTUCKY PRESENTLY...LOW
LEVEL MOISTURE SHOULD SPREAD BACK INTO THE AREA THROUGH
DAYBREAK...WITH CIGS COMING BACK DOWN TO MVFR LEVELS GENERALLY
BETWEEN 1-2K FEET. LIGHT SOUTHERLY WINDS WILL GRADUALLY SHIFT TO
THE SOUTHWEST AFTER DAYBREAK...BUT ARE NOT EXPECTED TO GET GUSTY.
A BAND OF SHOWERS/STORMS WILL PUSH INTO THE BLUEGRASS TOWARDS
DAYBREAK AND COULD IMPACT KSYM...WHICH WILL NEED TO BE UPDATED TO
INCLUDE THUNDER IF IT HOLDS TOGETHER. OTHERWISE...EXPECT JUST SOME
ISOLATED SHOWERS AS WE HEAD THROUGH TUESDAY WITH CIGS LIFTING
SLIGHTLY...BUT LIKELY STAYING MVFR. THERE IS A SMALL CHANCE WE
COULD SEE SOME PARTIAL CLEARING...BUT GIVEN THE TIME OF
YEAR...ODDS ON THIS ARE VERY LOW.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...HAL
LONG TERM...SHALLENBERGER
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
707 AM CST TUE DEC 22 2015
...SOUNDING DISCUSSION...
THE SOUNDING THIS MORNING IS SATURATED THROUGH AN INVERSION IN
THE FIRST 500 FT AND IS REPRESENTATIVE OF THE DENSE FOG CONDITIONS
IN PLACE. THE REST OF THE PROFILE DEPICTS A VERY MOIST AIRMASS
OVERALL WITH PW AT 1.73 INCHES... WHICH IS NEAR THE DAILY MAX IN
THE SPC CLIMATOLOGY. THE ATMOSPHERE HAS A BIT OF INSTABILITY WITH
CAPE IN THE MIXED LAYER AT 900 J/KG AND MOST UNSTABLE AT 1100
J/KG. THERE IS JUST A LITTLE BIT OF A WARM LAYER AT ABOUT 800 MB.
THIS FEATURE IS MORE PRONOUNCED ON THE LAKE CHARLES AND JACKSON
SOUNDINGS. WARM AIR OR AN INVERSION IN THIS LAYER WILL NEED TO BE
MONITORED AS A POTENTIAL LIMITING FACTOR ON CONVECTION TODAY AND
POSSIBLY TOMORROW. FLOW IS SOUTHWEST THROUGHOUT WITH PEAK WIND 80
KTS AT 200 MB.
KRAUTMANN
&&
.PREV DISCUSSION... /ISSUED 356 AM CST TUE DEC 22 2015/
SHORT TERM...
MOISTURE LEVELS REMAIN VERY HIGH ACROSS THE CENTRAL GULF COAST
THIS MORNING. THIS 00Z SOUNDING FROM YESTERDAY AFTERNOON HAD A
RECORD HIGH PRECIP WATER VALUE OF 1.92" WHICH IS PROBABLY IN THE
UPPER 90TH PERCENTILE FOR THE ENTIRE MONTH OF DECEMBER. THUS
SHOULDN/T BE ANY SURPRISE THAT WIDESPREAD FOG HAS DEVELOPED OVER
MUCH OF THE AREA. MANY OBSERVATIONS INDICATE VISIBILITIES OF
AROUND A HALF MILE OR LESS. SAMPLING INTERSTATE CAMERAS ALSO SHOWS
WHAT APPEARS TO BE LESS THAN 1/4 MILE VISIBILITIES IN SOME
LOCATIONS AS WELL. ALTHOUGH THE ENTIRE CWA PROBABLY DOES NOT NEED
A DENSE FOG ADVISORY...LEAVE THEM ABSENT WOULD PRODUCE A VERY ODD
LOOKING AND CONFUSING PRODUCT. SO WILL BE ISSUING A BLANKET DENSE
FOG ADVISORY FOR THE CWA THROUGH 15Z.
CURRENT RADAR SHOWS FIRST WAVE HEADED EAST ACROSS THE NORTHERN GULF
WATERS. LINGERING SHOWERS PERSIST SIMPLY DUE TO COLUMN SATURATION
AND MINIMAL BUOYANCY. EXTENSIVE CLOUD COVER SHOULD LIMIT WARMING
TODAY TO LOWER 70S ACROSS THE FORECAST AREA. THIS IS A GOOD THING AS
IT WILL LIMIT INSTABILITY POTENTIAL. NEVERTHELESS...A SHORT WAVE IS
PROGGED TO LIFT NORTHEAST OUT OF THE GULF ACROSS THE LOWER HALF OF
THE CWA. HRRR AND NMM AS WELL AS MEDIUM RANGE MODELS ALL PINGING ON
A LARGE SWATH OF NUMEROUS SHOWERS AND THUNDERSTORMS IMPACTING AREAS
SOUTH OF INTERSTATE 10. THE FORECAST POPS HAVE THUS BEEN ADJUSTED
FOR THIS. THE SEVERE POTENTIAL WILL REMAIN ON THE LOW SIDE BUT STILL
EXISTS. MODEL SOUNDINGS DO INDICATE ELEVATED INSTABILITY ACROSS THE
BOARD BUT A WEAK WIND FIELD DURING THE DAYTIME. GOING INTO THE NIGHT
THE WIND FIELD BEGINS TO INCREASE WITH SHEAR VALUES IN THE 40 TO 50
KNOT RANGE. THE QUESTION IS WHETHER OR NOT CELLS WILL BE SURFACE
BASED. IF MODEL SOUNDINGS HOLD TRUE...THEY WONT BE AND THUS THE ONLY
CHANCE TO MIX DOWN STRONGER WINDS THROUGH THE WARM NOSE IS THROUGH
PRECIP LOADING. WILL BE SOMETHING TO WATCH BUT NOT A HIGH CONCERN.
MARINE LOCATIONS WILL BE THE MOST LIKELY FOR STRONGER WIND GUSTS AND
WATERSPOUTS.
THE REAL SEVERE WEATHER THREAT LOOKS TO COME INTO PLAY ON WEDNESDAY.
BROAD LONG WAVE TROUGH ALREADY IN PLACE OVER THE ROCKIES WILL DIG
AND SWING NEGATIVE OVER THE CENTRAL PLAINS DURING THE DAY. DOWN AT
THE SURFACE A LOW ON THE LEESIDE OF THE ROCKIES WILL BE RACING
NORTHEAST ACROSS THE CENTRAL MISSISSIPPI VALLEY. SURFACE PRESSURES
IN THE CWA WILL BE SLOWLY FALLING DURING THE DAY WITH A MINIMUM OF
AROUND 1006 MB. TIGHTENING OF THE PRESSURE GRADIENT WILL INCREASE
SURFACE WINDS WHICH WILL THEN AIDE IN THE TRANSPORT OF 70 DEGREE
DEWPOINTS TO POINTS NORTH. PRESUMING THAT SFC TEMPS DO REACH MID 70S
WHILE THESE DEWPOINTS RISE...BUOYANCY AND INSTABILITY WILL SHOOT UP
DURING THE DAY. BOTH GFS AND NAM BUFR SOUNDINGS SHOW SB AND PARCEL
CAPE VALUES OVER 2000 J/KG AND MU CAPE UP TO 1500 J/KG ALL OVER THE
CWA. HELICITY VALUES AREN/T THAT IMPRESSIVE AT 200 M2/S2 BUT
SUFFICIENT. NOT SURPRISING WITH A FAIRLY UNIFORM WIND DIRECTION
THROUGHOUT THE COLUMN. OF MORE IMPORTANCE IS SPEED SHEAR AND JUST
THE VALUE OF THE WINDS THEMSELVES. LOOKING AT 40 TO 50 KNOTS IN THE
BOUNDARY LAYER WHICH IS PLENTY STRONG TO SUSTAIN SUPERCELLS. THE
PRECIP WATER VALUE IS IN A PRETTY NICE SWEET SPOT...NOT TOO HIGH AND
NOT TO LOW AT AROUND 1.5 INCHES. ALL OF THAT IS TO SAY THAT THE ODDS
OF SEVERE WEATHER FOR THE DAY WEDNESDAY LOOKING BETTER AND BETTER.
THE MAIN THREATS WILL BE TORNADOES AND DAMAGING WINDS. HOW
WIDESPREAD REMAINS TO BE SEEN. IF SFC TEMPS DONT WARM ENOUGH...WILL
JUST HAVE THE DYNAMICS. IF SOUTHEASTERLY FLOW IS TOO STRONG THAN THE
MARINE LAYER COULD BE PUSHED TOO FAR INLAND AND A WARM NOSE (SHOWN
CLEARLY ON THE GPT SOUNDING) WILL HINDER SFC BASED STORMS.
REGARDLESS...THE POTENTIAL IS DEFINITELY THERE AND WARRANTS THE SPC
SLIGHT FOR THE AREA.
LONG TERM...
RESIDUAL SURFACE BOUNDARY WILL BE THE FOCUS FOR CONVECTION ON
THURSDAY. AMPLE MOISTURE STILL LEFT IN THE AREA SHOULD HAVE NO
PROBLEM DEVELOPING INTO SHOWERS WITH POSSIBLY A FEW THUNDERSTORMS.
MUCH WEAKER WINDS IN THE COLUMN AND NON-SEVERE CONDUCING WIND
DIRECTIONS WILL LIMIT THE STRENGTH OF ACTIVITY. COVERAGE SHOULD
STILL BE OVER 50 PERCENT FOR THE MOST PART.
CHRISTMAS DAY COULD ACTUALLY HAVE THE LOWEST CHANCE OF RAIN FOR THE
ENTIRE WEEK AS UPPER LEVEL RIDGE CENTERED OVER THE WESTERN ATLANTIC
BUILDS BACK WESTWARD ACROSS THE CWA. PROBLEM IS THAT ITS STILL
CHANCE CATEGORY. ON THE TEMPERATURE SIDE OF THINGS...WILL NOT BE
FEELING TOO WINTER-LIKE WITH LOWS IN THE MID 60S AND HIGHS
APPROACHING 80 DEGREES IN ISOLATED LOCATIONS. A LITTLE PERSPECTIVE
ON HOW WARM IT WILL BE...THE FORECAST LOWS FOR CHRISTMAS DAY MORNING
ARE SEVERAL DEGREES WARMER THAN TYPICAL DAYTIME HIGHS FOR THIS TIME
OF YEAR. MAY NOT BREAK RECORDS BUT NOT TOO FAR OFF EITHER.
POPS TO FALL EVEN MORE DOWN INTO THE 20 TO 30 PERCENT RANGE THIS
WEEKEND AS THE RIDGE SHIFTS THE SHEAR ZONE FURTHER NORTH AND WEST.
GFS AND ECMWF BOTH CLOSE OFF A LOW IN THE DESERT SOUTHWEST AND
TRACKS EAST BEFORE SWINGING NE OVER THE CENTRAL PLAINS ENDING THE
WEEKEND. THIS WOULD BRING A LINE OF SHOWERS AND STORMS MOVING THRU
SOME TIME BETWEEN SUNDAY NIGHT AND MONDAY NIGHT DEPENDING ON MODEL
TIMING. DIDNT MAKE ANY SIGNIFICANT CHANCES TO POPS DUE TO CHANGING
SOLUTIONS WITH EACH MODEL ITERATION.
MEFFER
AVIATION...
FOG WILL BE THE ISSUE FOR A FEW TERMINALS THIS MORNING. THE
PROBLEMS THAT DENSE FOG WILL DEVELOP FOR A VERY SHORT DURATION THEN
LIFT JUST AS QUICK. HAVE SET PREVAILING TO SHOW VIS AT 2 TO 3SM WITH
TEMPO GROUPS SHOWING DOWN TO 1/4SM. WILL ALSO SHOW TS FOR BTR...HDC
AND ASD MAINLY DURING THE EARLY AFTERNOON. A SEPARATE COMPLEX WILL
AFFECT THE SOUTH SHORE TERMINALS FROM HUM TO NEW AND MSY THROUGH TO
GPT LATE IN THE AFTERNOON AND EVENING HOURS. WILL ALSO KEEP FOG IN
12Z TAF PACK.
MARINE... TS WILL BE RESPONSIBLE FOR PRODUCING SOME STRONG WIND
SPEEDS OVER THE COASTAL WATERS THROUGH TONIGHT. AVOID ANY AREAS
WHERE ARE LOCATED. LARGER SCALE WINDS SHOULD BEGIN TO INCREASE OVER
THE OUTER WATERS TONIGHT WITH EXERCISE CAUTION/SMALL CRAFT ADVISORY
HEADLINES LIKELY TO BE NECESSARY ON WEDNESDAY. CONDITIONS SHOULD
EASE A BIT ON THURSDAY WITH RELATIVELY QUIET WEATHER UNTIL NEXT
SUNDAY AHEAD OF A STRONGER SYSTEM MOVING THROUGH THE CENTER OF THE
COUNTRY.
DECISION SUPPORT...
DSS CODE....GREEN. DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING CONVECTIVE TRENDS.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER
IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED
WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO
MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR
OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 72 63 76 66 / 70 80 90 60
BTR 74 64 75 66 / 80 80 90 40
ASD 71 64 74 67 / 90 80 90 70
MSY 72 64 75 70 / 90 90 80 70
GPT 70 64 71 68 / 90 80 90 70
PQL 72 64 73 69 / 90 80 90 70
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR LAZ034>037-
039-040-046>050-056>072.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR GMZ530-532-
534-536-538-550-552-555.
MS...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR MSZ068>071-
077-080>082.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR GMZ532-534-
536-538-550-552-555.
&&
$$
AREA FORECAST DISCUSSION
NWS NEW ORLEANS LA
356 AM CST TUE DEC 22 2015
.SHORT TERM...
MOISTURE LEVELS REMAIN VERY HIGH ACROSS THE CENTRAL GULF COAST
THIS MORNING. THIS 00Z SOUNDING FROM YESTERDAY AFTERNOON HAD A
RECORD HIGH PRECIP WATER VALUE OF 1.92" WHICH IS PROBABLY IN THE
UPPER 90TH PERCENTILE FOR THE ENTIRE MONTH OF DECEMBER. THUS
SHOULDN/T BE ANY SURPRISE THAT WIDESPREAD FOG HAS DEVELOPED OVER
MUCH OF THE AREA. MANY OBSERVATIONS INDICATE VISIBILITIES OF
AROUND A HALF MILE OR LESS. SAMPLING INTERSTATE CAMERAS ALSO SHOWS
WHAT APPEARS TO BE LESS THAN 1/4 MILE VISIBILITIES IN SOME
LOCATIONS AS WELL. ALTHOUGH THE ENTIRE CWA PROBABLY DOES NOT NEED
A DENSE FOG ADVISORY...LEAVE THEM ABSENT WOULD PRODUCE A VERY ODD
LOOKING AND CONFUSING PRODUCT. SO WILL BE ISSUING A BLANKET DENSE
FOG ADVISORY FOR THE CWA THROUGH 15Z.
CURRENT RADAR SHOWS FIRST WAVE HEADED EAST ACROSS THE NORTHERN GULF
WATERS. LINGERING SHOWERS PERSIST SIMPLY DUE TO COLUMN SATURATION
AND MINIMAL BUOYANCY. EXTENSIVE CLOUD COVER SHOULD LIMIT WARMING
TODAY TO LOWER 70S ACROSS THE FORECAST AREA. THIS IS A GOOD THING AS
IT WILL LIMIT INSTABILITY POTENTIAL. NEVERTHELESS...A SHORT WAVE IS
PROGGED TO LIFT NORTHEAST OUT OF THE GULF ACROSS THE LOWER HALF OF
THE CWA. HRRR AND NMM AS WELL AS MEDIUM RANGE MODELS ALL PINGING ON
A LARGE SWATH OF NUMEROUS SHOWERS AND THUNDERSTORMS IMPACTING AREAS
SOUTH OF INTERSTATE 10. THE FORECAST POPS HAVE THUS BEEN ADJUSTED
FOR THIS. THE SEVERE POTENTIAL WILL REMAIN ON THE LOW SIDE BUT STILL
EXISTS. MODEL SOUNDINGS DO INDICATE ELEVATED INSTABILITY ACROSS THE
BOARD BUT A WEAK WIND FIELD DURING THE DAYTIME. GOING INTO THE NIGHT
THE WIND FIELD BEGINS TO INCREASE WITH SHEAR VALUES IN THE 40 TO 50
KNOT RANGE. THE QUESTION IS WHETHER OR NOT CELLS WILL BE SURFACE
BASED. IF MODEL SOUNDINGS HOLD TRUE...THEY WONT BE AND THUS THE ONLY
CHANCE TO MIX DOWN STRONGER WINDS THROUGH THE WARM NOSE IS THROUGH
PRECIP LOADING. WILL BE SOMETHING TO WATCH BUT NOT A HIGH CONCERN.
MARINE LOCATIONS WILL BE THE MOST LIKELY FOR STRONGER WIND GUSTS AND
WATERSPOUTS.
THE REAL SEVERE WEATHER THREAT LOOKS TO COME INTO PLAY ON WEDNESDAY.
BROAD LONG WAVE TROUGH ALREADY IN PLACE OVER THE ROCKIES WILL DIG
AND SWING NEGATIVE OVER THE CENTRAL PLAINS DURING THE DAY. DOWN AT
THE SURFACE A LOW ON THE LEESIDE OF THE ROCKIES WILL BE RACING
NORTHEAST ACROSS THE CENTRAL MISSISSIPPI VALLEY. SURFACE PRESSURES
IN THE CWA WILL BE SLOWLY FALLING DURING THE DAY WITH A MINIMUM OF
AROUND 1006 MB. TIGHTENING OF THE PRESSURE GRADIENT WILL INCREASE
SURFACE WINDS WHICH WILL THEN AIDE IN THE TRANSPORT OF 70 DEGREE
DEWPOINTS TO POINTS NORTH. PRESUMING THAT SFC TEMPS DO REACH MID 70S
WHILE THESE DEWPOINTS RISE...BUOYANCY AND INSTABILITY WILL SHOOT UP
DURING THE DAY. BOTH GFS AND NAM BUFR SOUNDINGS SHOW SB AND PARCEL
CAPE VALUES OVER 2000 J/KG AND MU CAPE UP TO 1500 J/KG ALL OVER THE
CWA. HELICITY VALUES AREN/T THAT IMPRESSIVE AT 200 M2/S2 BUT
SUFFICIENT. NOT SURPRISING WITH A FAIRLY UNIFORM WIND DIRECTION
THROUGHOUT THE COLUMN. OF MORE IMPORTANCE IS SPEED SHEAR AND JUST
THE VALUE OF THE WINDS THEMSELVES. LOOKING AT 40 TO 50 KNOTS IN THE
BOUNDARY LAYER WHICH IS PLENTY STRONG TO SUSTAIN SUPERCELLS. THE
PRECIP WATER VALUE IS IN A PRETTY NICE SWEET SPOT...NOT TOO HIGH AND
NOT TO LOW AT AROUND 1.5 INCHES. ALL OF THAT IS TO SAY THAT THE ODDS
OF SEVERE WEATHER FOR THE DAY WEDNESDAY LOOKING BETTER AND BETTER.
THE MAIN THREATS WILL BE TORNADOES AND DAMAGING WINDS. HOW
WIDESPREAD REMAINS TO BE SEEN. IF SFC TEMPS DONT WARM ENOUGH...WILL
JUST HAVE THE DYNAMICS. IF SOUTHEASTERLY FLOW IS TOO STRONG THAN THE
MARINE LAYER COULD BE PUSHED TOO FAR INLAND AND A WARM NOSE (SHOWN
CLEARLY ON THE GPT SOUNDING) WILL HINDER SFC BASED STORMS.
REGARDLESS...THE POTENTIAL IS DEFINITELY THERE AND WARRANTS THE SPC
SLIGHT FOR THE AREA.
.LONG TERM...
RESIDUAL SURFACE BOUNDARY WILL BE THE FOCUS FOR CONVECTION ON
THURSDAY. AMPLE MOISTURE STILL LEFT IN THE AREA SHOULD HAVE NO
PROBLEM DEVELOPING INTO SHOWERS WITH POSSIBLY A FEW THUNDERSTORMS.
MUCH WEAKER WINDS IN THE COLUMN AND NON-SEVERE CONDUCING WIND
DIRECTIONS WILL LIMIT THE STRENGTH OF ACTIVITY. COVERAGE SHOULD
STILL BE OVER 50 PERCENT FOR THE MOST PART.
CHRISTMAS DAY COULD ACTUALLY HAVE THE LOWEST CHANCE OF RAIN FOR THE
ENTIRE WEEK AS UPPER LEVEL RIDGE CENTERED OVER THE WESTERN ATLANTIC
BUILDS BACK WESTWARD ACROSS THE CWA. PROBLEM IS THAT ITS STILL
CHANCE CATEGORY. ON THE TEMPERATURE SIDE OF THINGS...WILL NOT BE
FEELING TOO WINTER-LIKE WITH LOWS IN THE MID 60S AND HIGHS
APPROACHING 80 DEGREES IN ISOLATED LOCATIONS. A LITTLE PERSPECTIVE
ON HOW WARM IT WILL BE...THE FORECAST LOWS FOR CHRISTMAS DAY MORNING
ARE SEVERAL DEGREES WARMER THAN TYPICAL DAYTIME HIGHS FOR THIS TIME
OF YEAR. MAY NOT BREAK RECORDS BUT NOT TOO FAR OFF EITHER.
POPS TO FALL EVEN MORE DOWN INTO THE 20 TO 30 PERCENT RANGE THIS
WEEKEND AS THE RIDGE SHIFTS THE SHEAR ZONE FURTHER NORTH AND WEST.
GFS AND ECMWF BOTH CLOSE OFF A LOW IN THE DESERT SOUTHWEST AND
TRACKS EAST BEFORE SWINGING NE OVER THE CENTRAL PLAINS ENDING THE
WEEKEND. THIS WOULD BRING A LINE OF SHOWERS AND STORMS MOVING THRU
SOME TIME BETWEEN SUNDAY NIGHT AND MONDAY NIGHT DEPENDING ON MODEL
TIMING. DIDNT MAKE ANY SIGNIFICANT CHANCES TO POPS DUE TO CHANGING
SOLUTIONS WITH EACH MODEL ITERATION.
MEFFER
&&
.AVIATION...
FOG WILL BE THE ISSUE FOR A FEW TERMINALS THIS MORNING. THE
PROBLEMS THAT DENSE FOG WILL DEVELOP FOR A VERY SHORT DURATION THEN
LIFT JUST AS QUICK. HAVE SET PREVAILING TO SHOW VIS AT 2 TO 3SM WITH
TEMPO GROUPS SHOWING DOWN TO 1/4SM. WILL ALSO SHOW TS FOR BTR...HDC
AND ASD MAINLY DURING THE EARLY AFTERNOON. A SEPARATE COMPLEX WILL
AFFECT THE SOUTH SHORE TERMINALS FROM HUM TO NEW AND MSY THROUGH TO
GPT LATE IN THE AFTERNOON AND EVENING HOURS. WILL ALSO KEEP FOG IN
12Z TAF PACK.
&&
.MARINE... TS WILL BE RESPONSIBLE FOR PRODUCING SOME STRONG WIND
SPEEDS OVER THE COASTAL WATERS THROUGH TONIGHT. AVOID ANY AREAS
WHERE ARE LOCATED. LARGER SCALE WINDS SHOULD BEGIN TO INCREASE OVER
THE OUTER WATERS TONIGHT WITH EXERCISE CAUTION/SMALL CRAFT ADVISORY
HEADLINES LIKELY TO BE NECESSARY ON WEDNESDAY. CONDITIONS SHOULD
EASE A BIT ON THURSDAY WITH RELATIVELY QUIET WEATHER UNTIL NEXT
SUNDAY AHEAD OF A STRONGER SYSTEM MOVING THROUGH THE CENTER OF THE
COUNTRY.
&&
DECISION SUPPORT...
DSS CODE....GREEN. DEPLOYED...NONE.
ACTIVATION...NONE.
ACTIVITIES...MONITORING CONVECTIVE TRENDS.
DECISION SUPPORT SERVICES (DSS) CODE LEGEND GREEN = NO WEATHER
IMPACTS THAT REQUIRE ACTION BLUE = LONG FUSED
WATCH/WARNING/ADVISORY IN EFFECT OR HIGH VISIBILITY EVENT
YELLOW = HEIGHTENED IMPACTS WITH SHORT FUSED WATCH/WARNING/ADVISORY
ISSUANCES; RADAR SUPPORT ORANGE = HIGH IMPACTS - SLIGHT TO
MODERATE RISK SEVERE; NEARBY TROPICAL EVENTS; HAZMAT OR
OTHER LARGE EPISODES RED = FULL ENGAGEMENT FOR MODERATE RISK SVR
AND/OR DIRECT TROPICAL THREATS; EVENTS OF NATIONAL
SIGNIFICANCE
&&
.PRELIMINARY POINT TEMPS/POPS...
MCB 72 63 76 66 / 70 80 90 60
BTR 74 64 75 66 / 80 80 90 40
ASD 71 64 74 67 / 90 80 90 70
MSY 72 64 75 70 / 90 90 80 70
GPT 70 64 71 68 / 90 80 90 70
PQL 72 64 73 69 / 90 80 90 70
&&
.LIX WATCHES/WARNINGS/ADVISORIES...
LA...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR LAZ034>037-
039-040-046>050-056>072.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR GMZ530-532-
534-536-538-550-552-555.
MS...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR MSZ068>071-
077-080>082.
GM...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR GMZ532-534-
536-538-550-552-555.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
939 PM EST WED DEC 23 2015
.SYNOPSIS...
LOW PRESSURE PASSES TO OUR WEST/NORTHWEST TONIGHT AND BRINGS
MODERATE TO HEAVY RAIN OUT AHEAD OF A WARM FRONT TONIGHT. THE
RAIN ENDS EARLY THURSDAY AND STRONG WARM AIR ADVECTION WILL SET
THE STAGE FOR SEVERAL RECORD HIGH TEMPERATURES TO BE
BROKEN...ESPECIALLY ACROSS SOUTHERN NEW HAMPSHIRE. A COLD FRONT
MOVES ACROSS THE AREA THURSDAY NIGHT AND ALTHOUGH TEMPERATURES
WILL RUN ABOUT 10 DEGREES COOLER ON CHRISTMAS DAY IT WILL STILL BE
QUITE PLEASANT WITH TEMPERATURES REMAINING WELL ABOVE NORMAL. OUR
NEXT STORM SYSTEM LOOKS TO ARRIVE LATE SATURDAY INTO SUNDAY AND
SHOULD BE MOSTLY IN THE FORM OF RAIN ONCE AGAIN. HOWEVER...COLDER
AIR WILL PUSH INTO THE REGION THE BEGINNING OF NEXT WEEK AND COULD
REMAIN IN PLACE LONG ENOUGH FOR SEVERAL LOCATIONS TO SEE THEIR
FIRST MEASURABLE SNOWFALL OF THE SEASON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPDATE...
MINOR ESTF UPDATE LATE THIS EVENING BASED ON CURRENT CONDITIONS
AND LATEST RADAR IMAGERY. RAIN CONTINUES ACROSS THE ENTIRE
FORECAST AREA AT THIS TIME. THIS PRECIPITATION HAS AIDED IN MIXING
THE DEEP LOW LEVEL MOISTURE. HENCE...VISIBILITIES CONTINUE TO COME
UP - IN MOST AREAS WITH JUST A FEW POCKETS OF DENSE FOG REMAINING.
AUG TO WVL SHOULD MIX OUT WITHIN THE NEXT HOUR. HRRR DID A GOOD
JOB ON PREDICTING THIS MIXING AND INCREASED VISIBILITIES THIS
EVENING.
WILL BE DROPPING THE DENSE FOG ADVISORIES OVER THE NEXT HALF HOUR.
AREAS OF FOG WILL REMAIN OVERNIGHT...HOWEVER WITH MUCH IMPROVED
VISIBILITIES.
PREV DISC... LOW LEVEL MOISTURE REMAINS TRAPPED BELOW A VERY
SHARP AND SHALLOW INVERSION EVIDENT ON THIS MORNINGS KGYX
SOUNDING. SOME AREAS IN NH HAVE MIXED OUT ON THE NORTHERN EDGE OF
A STRATIFORM RAIN SHIELD ALONG A NORTHWARD MOVING WARM FRONT. AS
THE DEW POINT DEPRESSIONS BECOME SMALLER HOWEVER FOG MAY AGAIN
FORM IN AREAS IT HAS ALREADY LIFTED.
THE DENSE FOG ADVISORY IN PLACE CONTINUES THROUGH 1 AM BUT
WILL LIKELY BE TRIMMED BACK AS THE RAIN ENTERS THE AREA AND
MECHANICALLY MIXES SOME OF THE MOISTURE OUT. HRRR AND OTHER
MESOSCALE MODELS INDICATE IN FACT THAT THE AREA OF DENSE FOG WILL
CONTINUE THROUGH AT LEAST MIDNIGHT BEFORE MOST OF IT DISSIPATES.
RAIN WILL BE HEAVY AT TIMES TONIGHT AND END MID MORNING
CHRISTMAS EVE. EXPECT DRIZZLE TONIGHT AND TOMORROW PRECEDING AND
BEHIND THE MAIN AREA OF PRECIPITATION. NOT EXPECTING THUNDERSTORMS
IN OUR AREA AS MID LEVEL INSTABILITY LOOKS TO STAY SOUTH. QPF
AMOUNTS WILL RANGE FROM A HALF INCH ACROSS THE NORTH TO ALMOST AN
INCH FROM THE FOOTHILLS SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MODELS ARE INDICATING A SIMILAR VERY SHARP INVERSION
TOMORROW AS TODAY...IE THE SAME LOW LEVEL LAYER OF MOISTURE WILL
ONLY MIX SO FAR EAST...DEPENDING ON WHERE THE WARM FRONT REACHES.
THERE IS LITTLE TO FORCE THE BOUNDARY UNTIL THE COLD FRONT
ARRIVES LATER CHRISTMAS EVE. THE NAM AND GEM ARE INDICATING A
VERY ABRUPT TEMPERATURE GRADIENT FROM WEST TO EAST ACROSS MAINE.
FOR THE MOST PART...NH WILL WARM INTO THE UPPER 50S TO EVEN UPPER
60S IN THE KEENE/MANCHESTER AREA AS THE WARM FRONT AT LEAST MAKES
IT THAT FAR. AS FOR MAINE...PORTIONS OF YORK COUNTY AND EVEN
CUMBERLAND COUNTY MIGHT REACH THE 60S...BUT FARTHER EAST WILL
LIKELY BE IN THE 50S AND EVEN UPPER 40S...AS SOME AREAS STRUGGLE
TO BREAK OUT OF FOG/STRATUS SIMILAR TO TODAY. ALL IN ALL IT WILL
BE A UNIQUE CHRISTMAS EVE FOR NEW ENGLAND...WITH RECORD-BREAKING
WARMTH LIKELY FROM NH SOUTHWEST.
RAIN...FOG...AND LOW LEVEL CLOUDS WILL BE SWEPT SOUTH AND EAST AS A
COLD FRONT MOVES THROUGH LATE CHRISTMAS EVE. SKIES SHOULD CLEAR OUT
FROM NORTH TO SOUTH EXCEPT FOR PERHAPS SOME CIRRUS.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
HIGHLIGHTS...
- ALTHOUGH COLD FRONT COMES THROUGH THURSDAY NIGHT...NEAR RECORD
TEMPERATURES WILL STILL BE POSSIBLE ON FRIDAY.
- FAST MOVING SYSTEM TO SPREAD MORE RAIN ACROSS MOST OF THE
REGION WITH POSSIBLE WINTRY MIX IN FAR NORTH.
- COOL HIGH PRESSURE WITH SEASONABLE TEMPS FOR THE BEGINNING OF
NEXT WEEK.
- POSSIBLE FIRST MEASURABLE SNOWFALL FOR MUCH OF THE AREA TUESDAY
INTO WEDNESDAY.
PATTERN SUMMARY: AS MENTIONED YESTERDAY...TELECONNECTION INDICES
WILL CONTINUE TO KEEP POLAR AIR CONFINED MOSTLY TO THE NORTH OF
THE REGION...WITH ONLY QUICK SHOTS OF SEASONABLE-LIKE WEATHER
FOLLOWED BY TEMPERATURES QUICKLY REBOUNDING TO ABOVE NORMAL
VALUES. THE HIGHLY AMPLIFIED RIDGE THAT IS OVER THE REGION TO
START THE PERIOD AND IS RESPONSIBLE FOR THE RECORD WARMTH FOR THE
NEXT TWO DAYS WILL FLATTEN OUT THIS WEEKEND. THIS WILL BRING US
BACK DOWN TO EARTH A BIT...WITH TEMPERATURES SATURDAY AND SUNDAY
LIKELY BEING ONLY SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR. AS
WE HEAD INTO EARLY NEXT WEEK...THE NORTHERN STREAM WILL SINK
SOUTHWARD SLIGHTLY...ENOUGH TO BRING SOME SEASONABLE TEMPERATURES
AS COLD CANADIAN HIGH PRESSURE SINKS OVER THE REGION. HOW STRONG
THIS HIGH PRESSURE IS WILL DETERMINE IF THE COLD AIR WILL HOLD ON
LONG ENOUGH TO ALLOW FOR DECENT OVERRUNNING AND PROVIDE MOST OF US
WITH OUR FIRST MEASURABLE SNOWFALL OF THE SEASON. STILL QUITE A
LOT OF UNCERTAINTY THOUGH AT THIS POINT IN THE FORECAST...SO SNOW
LOVERS WILL JUST HAVE TO KEEP THEIR FINGERS CROSSED AND HOPE THE
FORECAST UNFOLDS TO THEIR LIKING.
DAY BY DAY...
CHRISTMAS DAY: HIGH FORECAST CONFIDENCE
WEATHER IMPACTS: LOW
MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT FOR CHRISTMAS. COLD
FRONT PUSHES THROUGH THE AREA THURSDAY NIGHT INTO FRIDAY MORNING.
ALTHOUGH IT IS A COLD FRONT...THIS MAY ACTUALLY HELP SOME AREAS
WARM UP AS WARM AIR ALOFT MIXES DOWN TO THE SURFACE. TEMPERATURES
ARE LIKELY TO CLIMB TO NEAR RECORD VALUES ON FRIDAY AND DEPENDING
ON HOW FAR NORTH THE SURFACE WARM FRONT MAKES IT ON THURSDAY...MANY
PLACES MAY ACTUALLY TURN OUT WARMER ON CHRISTMAS DAY AS WE TAP
INTO THAT WARMER AIR ALOFT.
SATURDAY AND SUNDAY: MODERATE TO HIGH FORECAST CONFIDENCE
WEATHER IMPACTS: LOW
SHORT WAVE ARRIVES FROM THE SOUTHWEST SATURDAY NIGHT AND HIGH
PRESSURE OVERHEAD SHIFTS OFFSHORE. 12Z MODEL GUIDANCE HAS TRENDED
A BIT WARMER WITH TEMPERATURES ALOFT AND AT THE SURFACE WITH THIS
SYSTEM. FOR NOW IT APPEARS THAT THE BULK OF THE AREA WILL JUST SEE
LIQUID PRECIPITATION...BUT NORTHERN ZONES LOOK TO POTENTIALLY BE
BELOW FREEZING IN THE FOOTHILLS AND MOUNTAIN VALLEYS. THIS COULD
CAUSE A PERIOD OF POSSIBLE MIXED PRECIP OR FREEZING RAIN IN SOME
LOCATIONS. UPPER LEVEL FLOW WILL BE NEARLY ZONAL OVER THE
NORTHEAST CONUS BY THAT TIME...SO THIS SYSTEM SHOULD MOVE THROUGH
RATHER QUICKLY MAKING QPF LIMITED.
MONDAY - WEDNESDAY: LOW TO MODERATE FORECAST CONFIDENCE
WEATHER IMPACTS: POSSIBLY MODERATE WITH WINTRY PRECIPITATION
COLD CANADIAN HIGH PRESSURE DROPS DOWN OVER THE REGION AND
SHOULD MAKE FOR SEASONABLE HIGH TEMPERATURES. STRENGTH AND TIMING
OF THIS HIGH WILL DETERMINE HOW THE FORECAST UNFOLDS THEREAFTER.
EURO HAS STRONG HIGH PRESSURE MOVING RIGHT OVER NEW ENGLAND WHILE
THE GFS HAS A WEAKER SURFACE HIGH AND KEEPS THE HIGH IN CANADA
WITH SURFACE RIDGE EXTENDING OUT OVER NEW ENGLAND. THE EURO
SOLUTION WOULD KEEP COLD AIR IN PLACE MUCH LONGER AND DELAY THE
ONSET OF PRECIPITATION AS LOW PRESSURE APPROACHES FROM THE
SOUTHWEST. WARM AIR ADVECTION/OVERRUNNING ALOFT WILL BRING THE
POTENTIAL FOR PRECIPITATION TO START OFF AT LEAST AS ALL SNOW FOR
THE ENTIRE AREA. HOWEVER...WITH THE CURRENT TRACK OF THIS SYSTEM
FORECAST TO BE WEST OF THE REGION...AN EVENTUAL TRANSITION TO RAIN
WOULD LIKELY OCCUR ...BUT WILL CERTAINLY HAVE TO WATCH THE MODEL
TRENDS IN THE COMING DAYS AS THE 12Z EURO HAS NOW TRENDED EVEN
COLDER THAN THE 00Z RUN.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
SHORT TERM...AREAS OF DENSE FOG WILL MAKE FOR LIFR CONDITIONS
FOR MUCH OF THE NIGHT. RAIN WILL SPREAD FROM THE SW AND IMPROVE
VISIBILITIES FOR A TIME. RAIN MAY BE HEAVY AT TIMES HOWEVER...AND
DRIZZLE IS LIKELY ALONG THE COAST AHEAD OF AND BEHIND THE MAIN
PRECIPITATION SHIELD. FOG WILL AGAIN BE AN ISSUE THURSDAY MORNING.
LONG TERM...VFR CONDITIONS EXPECTED UNTIL SATURDAY NIGHT INTO
SUNDAY...AS OUR NEXT SYSTEM COMES THROUGH THE AREA AND IFR OR
LOWER CONDITIONS ARE POSSIBLE THRU THE DAY ON SUNDAY. CANNOT RULE
OUT SOME MIXED PRECIP EITHER...ESPECIALLY FOR NORTHERN TERMINALS.
AT THIS TIME FORECAST CONFIDENCE IS LOW REGARDING SPECIFIC PRECIP
TYPES. HIGH PRESSURE AND VFR CONDITIONS WILL BUILD BACK INTO THE
REGION FOR MONDAY.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORY IS IN EFFECT BEGINNING TONIGHT
THROUGH TOMORROW FOR THE BAYS AND OUTER WATERS.
LONG TERM...HIGH PRESSURE AND OUR NEXT ARRIVAL OF COLD AIR WILL
BE MONDAY AND THIS MAY BRING A PERIOD OF SCA CONDITIONS WITH IT.
THIS WILL BE FOLLOWED BY A LOW PRESSURE LIKELY PASSING WEST OF
THE WATERS...WITH SOUTHWESTERLY WINDS WITH SCA CONDITIONS AHEAD
OF IT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THURSDAY FOR ANZ151-153.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ150-152-
154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS GRAY ME
714 PM EST WED DEC 23 2015
.SYNOPSIS...
LOW PRESSURE PASSES TO OUR WEST/NORTHWEST TONIGHT AND BRINGS
MODERATE TO HEAVY RAIN OUT AHEAD OF A WARM FRONT TONIGHT. THE
RAIN ENDS EARLY THURSDAY AND STRONG WARM AIR ADVECTION WILL SET
THE STAGE FOR SEVERAL RECORD HIGH TEMPERATURES TO BE
BROKEN...ESPECIALLY ACROSS SOUTHERN NEW HAMPSHIRE. A COLD FRONT
MOVES ACROSS THE AREA THURSDAY NIGHT AND ALTHOUGH TEMPERATURES
WILL RUN ABOUT 10 DEGREES COOLER ON CHRISTMAS DAY IT WILL STILL BE
QUITE PLEASANT WITH TEMPERATURES REMAINING WELL ABOVE NORMAL. OUR
NEXT STORM SYSTEM LOOKS TO ARRIVE LATE SATURDAY INTO SUNDAY AND
SHOULD BE MOSTLY IN THE FORM OF RAIN ONCE AGAIN. HOWEVER...COLDER
AIR WILL PUSH INTO THE REGION THE BEGINNING OF NEXT WEEK AND COULD
REMAIN IN PLACE LONG ENOUGH FOR SEVERAL LOCATIONS TO SEE THEIR
FIRST MEASURABLE SNOWFALL OF THE SEASON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPDATE...
MINOR ESTF UPDATE THIS EVENING BASED ON CURRENT CONDITIONS AND
LATEST RADAR IMAGERY. RAIN CONTINUES TO OVERSPREAD THE REGION FROM
WEST TO EAST WHILE VISIBILITIES IN MAINE AND ADJACENT AREAS IN NEW
HAMPSHIRE REMAIN 1/2 MILE OR LOWER IN MANY AREAS. WILL CONTINUE
THE DENSE FOG ADVISORIES TONIGHT. MADE SOME ADJUSTMENTS BY
INCREASING THE VISIBILITY FORECAST OVER IN NEW HAMPSHIRE THIS
EVENING.
MESOSCALE FOG PRODUCTS INDICATES THE FOG SHOULD BEGIN LIFTING
SOMEWHAT AFTER 06Z. FEEL THIS MAY BE A LITTLE PREMATURE...SO HAVE
LEFT SOME FOG IN THE FORECAST INTO THURSDAY MORNING. OTRW...LITTLE
CHANGE TO THE FORECAST PACKAGE.
PREV DISC...
LOW LEVEL MOISTURE REMAINS TRAPPED BELOW A VERY SHARP
AND SHALLOW INVERSION EVIDENT ON THIS MORNINGS KGYX SOUNDING. SOME
AREAS IN NH HAVE MIXED OUT ON THE NORTHERN EDGE OF A STRATIFORM
RAIN SHIELD ALONG A NORTHWARD MOVING WARM FRONT. AS THE DEW POINT
DEPRESSIONS BECOME SMALLER HOWEVER FOG MAY AGAIN FORM IN AREAS IT
HAS ALREADY LIFTED.
THE DENSE FOG ADVISORY IN PLACE CONTINUES THROUGH 1 AM BUT
WILL LIKELY BE TRIMMED BACK AS THE RAIN ENTERS THE AREA AND
MECHANICALLY MIXES SOME OF THE MOISTURE OUT. HRRR AND OTHER
MESOSCALE MODELS INDICATE IN FACT THAT THE AREA OF DENSE FOG WILL
CONTINUE THROUGH AT LEAST MIDNIGHT BEFORE MOST OF IT DISSIPATES.
RAIN WILL BE HEAVY AT TIMES TONIGHT AND END MID MORNING
CHRISTMAS EVE. EXPECT DRIZZLE TONIGHT AND TOMORROW PRECEDING AND
BEHIND THE MAIN AREA OF PRECIPITATION. NOT EXPECTING THUNDERSTORMS
IN OUR AREA AS MID LEVEL INSTABILITY LOOKS TO STAY SOUTH. QPF
AMOUNTS WILL RANGE FROM A HALF INCH ACROSS THE NORTH TO ALMOST AN
INCH FROM THE FOOTHILLS SOUTH.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
MODELS ARE INDICATING A SIMILAR VERY SHARP INVERSION
TOMORROW AS TODAY...IE THE SAME LOW LEVEL LAYER OF MOISTURE WILL
ONLY MIX SO FAR EAST...DEPENDING ON WHERE THE WARM FRONT REACHES.
THERE IS LITTLE TO FORCE THE BOUNDARY UNTIL THE COLD FRONT
ARRIVES LATER CHRISTMAS EVE. THE NAM AND GEM ARE INDICATING A
VERY ABRUPT TEMPERATURE GRADIENT FROM WEST TO EAST ACROSS MAINE.
FOR THE MOST PART...NH WILL WARM INTO THE UPPER 50S TO EVEN UPPER
60S IN THE KEENE/MANCHESTER AREA AS THE WARM FRONT AT LEAST MAKES
IT THAT FAR. AS FOR MAINE...PORTIONS OF YORK COUNTY AND EVEN
CUMBERLAND COUNTY MIGHT REACH THE 60S...BUT FARTHER EAST WILL
LIKELY BE IN THE 50S AND EVEN UPPER 40S...AS SOME AREAS STRUGGLE
TO BREAK OUT OF FOG/STRATUS SIMILAR TO TODAY. ALL IN ALL IT WILL
BE A UNIQUE CHRISTMAS EVE FOR NEW ENGLAND...WITH RECORD-BREAKING
WARMTH LIKELY FROM NH SOUTHWEST.
RAIN...FOG...AND LOW LEVEL CLOUDS WILL BE SWEPT SOUTH AND EAST AS A
COLD FRONT MOVES THROUGH LATE CHRISTMAS EVE. SKIES SHOULD CLEAR OUT
FROM NORTH TO SOUTH EXCEPT FOR PERHAPS SOME CIRRUS.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
HIGHLIGHTS...
- ALTHOUGH COLD FRONT COMES THROUGH THURSDAY NIGHT...NEAR RECORD
TEMPERATURES WILL STILL BE POSSIBLE ON FRIDAY.
- FAST MOVING SYSTEM TO SPREAD MORE RAIN ACROSS MOST OF THE
REGION WITH POSSIBLE WINTRY MIX IN FAR NORTH.
- COOL HIGH PRESSURE WITH SEASONABLE TEMPS FOR THE BEGINNING OF
NEXT WEEK.
- POSSIBLE FIRST MEASURABLE SNOWFALL FOR MUCH OF THE AREA TUESDAY
INTO WEDNESDAY.
PATTERN SUMMARY: AS MENTIONED YESTERDAY...TELECONNECTION INDICES
WILL CONTINUE TO KEEP POLAR AIR CONFINED MOSTLY TO THE NORTH OF
THE REGION...WITH ONLY QUICK SHOTS OF SEASONABLE-LIKE WEATHER
FOLLOWED BY TEMPERATURES QUICKLY REBOUNDING TO ABOVE NORMAL
VALUES. THE HIGHLY AMPLIFIED RIDGE THAT IS OVER THE REGION TO
START THE PERIOD AND IS RESPONSIBLE FOR THE RECORD WARMTH FOR THE
NEXT TWO DAYS WILL FLATTEN OUT THIS WEEKEND. THIS WILL BRING US
BACK DOWN TO EARTH A BIT...WITH TEMPERATURES SATURDAY AND SUNDAY
LIKELY BEING ONLY SLIGHTLY ABOVE AVERAGE FOR THIS TIME OF YEAR. AS
WE HEAD INTO EARLY NEXT WEEK...THE NORTHERN STREAM WILL SINK
SOUTHWARD SLIGHTLY...ENOUGH TO BRING SOME SEASONABLE TEMPERATURES
AS COLD CANADIAN HIGH PRESSURE SINKS OVER THE REGION. HOW STRONG
THIS HIGH PRESSURE IS WILL DETERMINE IF THE COLD AIR WILL HOLD ON
LONG ENOUGH TO ALLOW FOR DECENT OVERRUNNING AND PROVIDE MOST OF US
WITH OUR FIRST MEASURABLE SNOWFALL OF THE SEASON. STILL QUITE A
LOT OF UNCERTAINTY THOUGH AT THIS POINT IN THE FORECAST...SO SNOW
LOVERS WILL JUST HAVE TO KEEP THEIR FINGERS CROSSED AND HOPE THE
FORECAST UNFOLDS TO THEIR LIKING.
DAY BY DAY...
CHRISTMAS DAY: HIGH FORECAST CONFIDENCE
WEATHER IMPACTS: LOW
MODEL GUIDANCE IS IN FAIRLY GOOD AGREEMENT FOR CHRISTMAS. COLD
FRONT PUSHES THROUGH THE AREA THURSDAY NIGHT INTO FRIDAY MORNING.
ALTHOUGH IT IS A COLD FRONT...THIS MAY ACTUALLY HELP SOME AREAS
WARM UP AS WARM AIR ALOFT MIXES DOWN TO THE SURFACE. TEMPERATURES
ARE LIKELY TO CLIMB TO NEAR RECORD VALUES ON FRIDAY AND DEPENDING
ON HOW FAR NORTH THE SURFACE WARM FRONT MAKES IT ON THURSDAY...MANY
PLACES MAY ACTUALLY TURN OUT WARMER ON CHRISTMAS DAY AS WE TAP
INTO THAT WARMER AIR ALOFT.
SATURDAY AND SUNDAY: MODERATE TO HIGH FORECAST CONFIDENCE
WEATHER IMPACTS: LOW
SHORT WAVE ARRIVES FROM THE SOUTHWEST SATURDAY NIGHT AND HIGH
PRESSURE OVERHEAD SHIFTS OFFSHORE. 12Z MODEL GUIDANCE HAS TRENDED
A BIT WARMER WITH TEMPERATURES ALOFT AND AT THE SURFACE WITH THIS
SYSTEM. FOR NOW IT APPEARS THAT THE BULK OF THE AREA WILL JUST SEE
LIQUID PRECIPITATION...BUT NORTHERN ZONES LOOK TO POTENTIALLY BE
BELOW FREEZING IN THE FOOTHILLS AND MOUNTAIN VALLEYS. THIS COULD
CAUSE A PERIOD OF POSSIBLE MIXED PRECIP OR FREEZING RAIN IN SOME
LOCATIONS. UPPER LEVEL FLOW WILL BE NEARLY ZONAL OVER THE
NORTHEAST CONUS BY THAT TIME...SO THIS SYSTEM SHOULD MOVE THROUGH
RATHER QUICKLY MAKING QPF LIMITED.
MONDAY - WEDNESDAY: LOW TO MODERATE FORECAST CONFIDENCE
WEATHER IMPACTS: POSSIBLY MODERATE WITH WINTRY PRECIPITATION
COLD CANADIAN HIGH PRESSURE DROPS DOWN OVER THE REGION AND
SHOULD MAKE FOR SEASONABLE HIGH TEMPERATURES. STRENGTH AND TIMING
OF THIS HIGH WILL DETERMINE HOW THE FORECAST UNFOLDS THEREAFTER.
EURO HAS STRONG HIGH PRESSURE MOVING RIGHT OVER NEW ENGLAND WHILE
THE GFS HAS A WEAKER SURFACE HIGH AND KEEPS THE HIGH IN CANADA
WITH SURFACE RIDGE EXTENDING OUT OVER NEW ENGLAND. THE EURO
SOLUTION WOULD KEEP COLD AIR IN PLACE MUCH LONGER AND DELAY THE
ONSET OF PRECIPITATION AS LOW PRESSURE APPROACHES FROM THE
SOUTHWEST. WARM AIR ADVECTION/OVERRUNNING ALOFT WILL BRING THE
POTENTIAL FOR PRECIPITATION TO START OFF AT LEAST AS ALL SNOW FOR
THE ENTIRE AREA. HOWEVER...WITH THE CURRENT TRACK OF THIS SYSTEM
FORECAST TO BE WEST OF THE REGION...AN EVENTUAL TRANSITION TO RAIN
WOULD LIKELY OCCUR ...BUT WILL CERTAINLY HAVE TO WATCH THE MODEL
TRENDS IN THE COMING DAYS AS THE 12Z EURO HAS NOW TRENDED EVEN
COLDER THAN THE 00Z RUN.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
SHORT TERM...AREAS OF DENSE FOG WILL MAKE FOR LIFR CONDITIONS
FOR MUCH OF THE NIGHT. RAIN WILL SPREAD FROM THE SW AND IMPROVE
VISIBILITIES FOR A TIME. RAIN MAY BE HEAVY AT TIMES HOWEVER...AND
DRIZZLE IS LIKELY ALONG THE COAST AHEAD OF AND BEHIND THE MAIN
PRECIPITATION SHIELD. FOG WILL AGAIN BE AN ISSUE THURSDAY MORNING.
LONG TERM...VFR CONDITIONS EXPECTED UNTIL SATURDAY NIGHT INTO
SUNDAY...AS OUR NEXT SYSTEM COMES THROUGH THE AREA AND IFR OR
LOWER CONDITIONS ARE POSSIBLE THRU THE DAY ON SUNDAY. CANNOT RULE
OUT SOME MIXED PRECIP EITHER...ESPECIALLY FOR NORTHERN TERMINALS.
AT THIS TIME FORECAST CONFIDENCE IS LOW REGARDING SPECIFIC PRECIP
TYPES. HIGH PRESSURE AND VFR CONDITIONS WILL BUILD BACK INTO THE
REGION FOR MONDAY.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORY IS IN EFFECT BEGINNING TONIGHT
THROUGH TOMORROW FOR THE BAYS AND OUTER WATERS.
LONG TERM...HIGH PRESSURE AND OUR NEXT ARRIVAL OF COLD AIR WILL
BE MONDAY AND THIS MAY BRING A PERIOD OF SCA CONDITIONS WITH IT.
THIS WILL BE FOLLOWED BY A LOW PRESSURE LIKELY PASSING WEST OF
THE WATERS...WITH SOUTHWESTERLY WINDS WITH SCA CONDITIONS AHEAD
OF IT.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...DENSE FOG ADVISORY UNTIL 1 AM EST THURSDAY FOR MEZ007>009-
012>014-018>028.
NH...DENSE FOG ADVISORY UNTIL 1 AM EST THURSDAY FOR NHZ010-014.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THURSDAY FOR ANZ151-153.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ150-152-
154.
&&
$$
JC
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
950 PM EST WED DEC 23 2015
.SYNOPSIS...
A WARM FRONT IS PUSHING NORTH THROUGH THE REGION. A COLD FRONT
WILL MOVE INTO THE AREA EARLY FRIDAY AND REMAIN NEARBY THROUGH THE
WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
AS OF 9PM...FIRST ROUND OF RAIN IS THROUGH. LINES OF HEAVY
SHOWERS AND ISOLATED THUNDERSTORMS MOVED THROUGH THE DC/BALT METRO
THEN DISCRETE SUPERCELLS (ELEVATED MESOCYCLONES) CROSSED SRN MD.
LOW PRESSURE IS OVER WI WITH THE MID-ATLANTIC FIRMLY IN THE WARM
SECTOR THROUGH THURSDAY.
NEXT LINE OF ACTIVITY IS AHEAD OF THE COLD FRONT AND MOVING EAST
THROUGH OHIO. HRRR HAS THIS ACTIVITY WANING BEFORE IT REACHES THE
ALLEGHENY HIGHLANDS (CURRENTLY ON TRACK FOR AROUND MIDNIGHT). WILL
NEED TO KEEP EYES ON THIS ACTIVITY THAT IS STILL GOING STRONG FOR
NOW.
MILD WITH LOW CLOUDS/FOG REFORMING OVER THE AREA IS THE STORY FOR
TONIGHT. MIN TEMPS MAY WELL HAVE BEEN REACHED IN THE MOST RECENT
RAIN. TEMPERATURES SHOULD EITHER HOLD STEADY OR SLOWLY INCREASE
REST OF THE NIGHT IN SLY FLOW 5-10MPH.
TEMPS THURSDAY HAVE BEEN THE TOPIC OF MUCH DISCUSSION GIVEN THEIR
EXPECTED EXCEEDENCE OF DAILY AND POSSIBLE MONTHLY MAX AND HI MIN
RECORDS. IN FACT...TEMPERATURES THIS EVENING ARE APPROACHING THE
MAX TEMPS FOR THURSDAY (SEE CLIMATE SECTION BELOW). GIVEN CLOUD
COVER/ADVECTION FOG...LOW CONFIDENCE IN VALUES...WENT WITH A BLEND
OF GMOS/MAV/MET/ SUPERBLEND WHICH GIVES LOW TO MID 70S. IT WOULD
BE EVEN HIGHER IF IT WERE SUNNY.
MARGINAL RISK FOR SEVERE WEATHER STILL ACROSS THE CWA WITH THE
PREFRONTAL ACTIVITY CURRENTLY OVER OHIO EXPECTED TO REDEVELOP
THROUGH THE MORNING ACROSS THE WRN PORTION OF THE CWA...THEN
PROGRESS EAST. HOWEVER...AS WITH MOST MESOSCALE DRIVEN
ACTIVITY...THERE IS LOW CONFIDENCE/COULD BE A SLOW BIAS TO
PROGRESS. IT MAY END UP BEING A RAINY DAY FOR PARTS OF THE AREA.
HIGH SHEAR/HELICITY VALUES AGAIN TOMORROW...SO A DAMAGING
WIND/ISOLATED TORNADO THREAT EXISTS.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH 6 PM THURSDAY/...
THU COULD BE AN ACTIVE DAY. VIRTUALLY ENTIRE CWA IS OUTLOOKED IN
MRGNL RISK. AT SOME TIMES OF THE YR THIS WOULD NOT RAISE AN
EYEBROW BUT THIS IS XMAS EVE. BUT IT CERTAINLY LOOKS WARRANTED
GIVEN THE 45 KTS BEING PROGGED AT 850MB. STORMS WON`T BE OVERLY
TALL...BUT W/ SKINNY CAPE IN THE SNDGS THERE IS PTNL FOR STORM
DVLPMNT AND TO BRING THOSE WINDS TO THE SFC.
XMAS EVE DAYTIME TEMPS IN THE LM70S E OF THE MTNS. IF REALIZED THESE
WQULD ALSO BRK RECORD HIGH TEMPS (SEE BLO) ALTHO NOT THE UTTER
DECIMATION THAT IAD`S LOW MAY SEE.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
LEANED HEAVILY ON BLENDED AND WPC DATASETS FROM THURSDAY NIGHT
THROUGH THE WEEKEND AS A WAVY FRONT LINGERS ACROSS THE
AREA...AFFECTING CHANCES OF RAIN AND TEMPERATURES. ALOFT...RIDGE
REMAINS NEARLY STATIONARY OFF THE SE COAST. A SW FLOW WILL KEEP A
CONNECTION TO THE GULF OF MEXICO WITH UNSEASONABLY HIGH PWATS
(GENERALLY STAYING NEAR OR ABOVE 1 INCH). THE SUMMARY FOR THE
PERIOD IS CONTINUED WELL-ABOVE NORMAL/RECORD TEMPERATURES AND
VERY LITTLE RESPITE FROM CHANCES OF RAIN. WHILE MODERATE RAINFALL
WILL BE POSSIBLE AT TIMES...AMOUNTS SHOULD BE SPREAD OVER A LONG
ENOUGH PERIOD OF TIME TO PRECLUDE FLOODING CONCERNS.
FRONT SETTLES SOUTH THURSDAY NIGHT AS TRANSIENT HIGH PRESSURE PASSES
BY TO THE NORTH. MODELS DIFFER ON HOW QUICKLY THE FRONT LIFTS BACK
TO THE NORTH...BUT HAS A GOOD CHANCE OF BEING NORTH OF THE AREA BY
SATURDAY NIGHT-SUNDAY AS LOW PRESSURE LIFTS TOWARDS THE GREAT LAKES.
THE LOW THEN SENDS THE FRONT BACK SOUTHWARD SUNDAY NIGHT. GUIDANCE
INDICATING BOTH CHRISTMAS DAY AND SUNDAY HAVE POTENTIAL TO REACH
THE 70S AGAIN...WITH SATURDAY NOT BEING MUCH COOLER. FRONTAL
TIMING AND PRECIP COULD HAVE AN EFFECT THOUGH. LOWS PROBABLY WILL
NOT DROP BELOW 50 IN MOST AREAS UNTIL SUNDAY NIGHT...ASSUMING THE
FRONT PUSHES SOUTH. BEST CHANCE FOR A DRY PERIOD WILL BE SATURDAY
NIGHT- SUNDAY IN THE WARM SECTOR.
/MON THROUGH WED/... LOW CONFIDENCE ON THE LONG TERM PERIOD AS
MODELS DISAGREE ON PRECIP...TEMPS AND LOCATION OF FRONTAL
BOUNDARIES. GFS SOLUTION IS WETTER AND COLDER THAN ECMWF...BUT
THEY BOTH AGREE THAT A COLD FRONT WILL MOVE ACROSS OUR CWA TUE. IN
GENERAL...LEFT A CHANCE OF PRECIP EACH DAY DURING THIS PERIOD...
WITH TEMPS STILL ABOVE NORMAL...BUT NOT AS FAR FROM NORMAL AS THE
WEEKEND.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
IFR CONDS PREVAIL THROUGH THE NIGHT WITH GREAT HUMIDITY FOR THIS
TIME OF YEAR. XMAS EVE WL SEE THE CHC OF TSTMS WHICH COULD BRING
STRONG WINDS TO THE SFC.
A FRONT WILL LINGER NEAR THE AREA THROUGH THE WEEKEND...WHICH WILL
PROMOTE PERIODS OF RAIN...ALONG WITH LOW CIGS AND VSBYS. SPECIFIC
TIMING IS UNCERTAIN...BUT BEST CHANCE FOR IFR MAY BE LATE FRIDAY
THROUGH EARLY SATURDAY. POTENTIAL FOR SW WIND GUSTS OF 20 KT OR
GREATER ON SUNDAY.
&&
.MARINE...
SCA IN EFFECT TNGT AND MAJORITY OF XMAS EVE FOR SLY/SWLY FLOW
GUSTING 20 TO 25 KT. ISOLD TSTMS DURG THE AFTN WL HV THE PTNL TO
BRING STRONG WINDS TO THE SFC WHICH COULD REQUIRE SMW`S.
AS FRONT SINKS SOUTH THURSDAY NIGHT...WINDS WILL DROP BELOW SCA
LEVELS. PROBABILITY OF SCA-LEVEL WINDS LOOKS LOW THROUGH SATURDAY
NIGHT AS THE WEAK FRONT WAFFLES ACROSS THE REGION...ALTHOUGH THERE
WILL BE PERIODS OF RAIN. AS LOW PRESSURE PASSES BY TO THE NORTH
SUNDAY...SW WINDS MAY REACH SCA LEVELS...THEN SHIFTING TO THE NW IF
THE FRONT IS ABLE TO MOVE SOUTH SUNDAY NIGHT.
&&
.CLIMATE...
THE DEC 24 DAILY AND DEC MONTHLY RECORDS...BOTH HIGHS AND HIGH
MINS:
DEC 24 DEC RECORD
HIGH HIGH MIN HIGH HIGH MIN
IAD 66 42 79 62
DCA 69 58 79 59
BWI 65 53 77 62
XMAS EVE FCSTS FOR THE 3 MAJOR AIRPORTS ARE:
LOWS HIGHS
IAD 63 73
DCA 64 74
BWI 61 74
WARMEST DECEMBER AVERAGE TEMPERATURE THROUGH THE 22ND...
DCA BWI IAD
1. 50.5 (2001) 1. 47.2 (1998) 1. 47.2 (1998)
2. 50.2 (1998) 2. 47.1 (2001) 2. 46.5 (2001)
3. 49.2 (2015) 3. 46.3 (2015) 3. 45.9 (2015)
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...NONE.
VA...NONE.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR ANZ530-531-
535-536-538-539.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THURSDAY FOR ANZ532-533-
540>542.
SMALL CRAFT ADVISORY UNTIL 9 PM EST THURSDAY FOR ANZ534-537-
543.
&&
$$
UPDATE...JACKSON
PREVIOUS...WOODY!/ADS/IMR
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1027 PM EST WED DEC 23 2015
.UPDATE...
THE FORECAST UPDATE WILL EXTEND THE WIND ADVISORY OVER THE REST
OF SE MICHIGAN AND MAKE IT VALID WITH ISSUANCE. MID TO LATE
EVENING SURFACE OBSERVATIONS REPORT FREQUENT SOUTH WIND GUSTS IN
THE MID 30 MPH RANGE WITH A FEW REPORTS OVER 40 MPH. THIS IS
OCCURRING IN THE WARM SECTOR IN PLACE OVER LOWER MICHIGAN
ASSOCIATED WITH RAPIDLY DEEPENING LOW PRESSURE OVER WISCONSIN. THE
NEUTRAL STABILITY PROFILE ADVERTISED IN RAP MODEL SOUNDINGS
SUGGESTS WARM SECTOR GUSTS COULD REACH 45 MPH BEFORE THE COLD
FRONT ARRIVES OVERNIGHT. AS FOR THE COLD FRONT ITSELF...UPSTREAM
OBSERVATIONS REPORT PEAK GUSTS AROUND 50 MPH AS FAR SOUTH AS
PEORIA/IL WITHIN STRONG ISALLOBARIC FORCING. THE EXTRA FORCING AND
50 MPH PEAK GUSTS WILL BE SHORT-LIVED BUT MID 40 MPH GUSTS WILL
REMAIN COMMON THROUGH MID THURSDAY MORNING. THE 10 AM EXPIRATION
TIME OF THE HEADLINE LOOKS GOOD.
&&
.AVIATION...ISSUED 732 PM EST WED DEC 23 2015
WITH THE INTENSE LINE OF SHOWERS EAST OF THE TERMINAL CORRIDOR...
EXPECT A COUPLE MORE HOURS OF WEAKER SHOWERS BEFORE A BREAK IN THE
RAIN OCCURS FOR THE REST OF THE EVENING INTO EARLY OVERNIGHT.
BORDERLINE VFR/MVFR CEILING WILL THEN PRECEDE A COLD FRONT THAT WILL
SURGE ACROSS LOWER MICHIGAN BEFORE SUNRISE. THE FRONT WILL BRING
ANOTHER ROUND OF SHOWERS...BUT THE MAIN STORY WILL BE STRONG
WESTERLY WIND GUSTS REACHING THE 30 TO 40 KNOT RANGE. THERE IS
POTENTIAL FOR EVEN HIGHER GUSTS AT FNT AND MBS WHICH WILL BE
MONITORED FOR IN UPSTREAM OBSERVATIONS DURING THE NIGHT. THE GUSTY
CONDITIONS WILL LAST THROUGH MID MORNING BEFORE STEADILY DECREASING
DURING THE REST OF THURSDAY. THE AIR BEHIND THE FRONT WILL BE JUST
SLIGHTLY COOLER BUT MUCH DRIER WHICH WILL SUPPORT VFR CONDITIONS
INTO THURSDAY EVENING.
FOR DTW... A COUPLE MORE HOURS OF LIGHT RAIN AND MVFR CONDITIONS
WILL BE FOLLOWED BY BORDERLINE MVFR/VFR CEILING AND A BREAK IN
PRECIPITATION INTO THE EARLY OVERNIGHT. TIMING ON THE COLD FRONTAL
PASSAGE LOOKS SOLID AROUND 09Z WITH WESTERLY WIND GUSTS REACHING THE
30 TO 40 KNOT RANGE.
//DTW THRESHOLD PROBABILITIES...
* MODERATE FOR CEILING BELOW 5000 FEET TONIGHT.
* MODERATE TO HIGH FOR GUSTS EXCEEDING CROSSWIND THRESHOLD AFTER 09Z.
&&
.PREV DISCUSSION...ISSUED 323 PM EST WED DEC 23 2015
DISCUSSION...
STRONG SURFACE LOW HAS BEGUN ITS NEXT DEEPENING PHASE THIS AFTERNOON
AS VIGOROUS SHORTWAVE HAS ROUNDED THE BASE OF THE MEAN UPPER LEVEL
TROUGH OVER THE PLAINS/MIDWEST. THE 982MB LOW OVER EC IOWA WILL
DEEPEN TO ABOUT 974MB BY THE TIME IT REACHES LAKE SUPERIOR TONIGHT
AND THEN CONTINUE STRENGTHEN IS IT LIFTS TO JAMES BAY AND BEYOND ON
THURSDAY.
WARM FRONT IN ADVANCE OF THIS SYSTEM IS CURRENTLY WORKING NORTH
THROUGH THE FORECAST AREA WITH ALL LOCATIONS NOW CLIMB THROUGH THE
50S WITH A FEW 60 DEGREE READINGS NOTED SOUTH OF DETROIT. DEWPOINTS
WITHIN THIS MILDEST SECTOR HAVE ALSO CLIMBED INTO THE UPPER 50S AS
MODELS SUGGESTED WOULD OCCUR. AS THE WARM AND MOIST AIR CONTINUES TO
OVERSPREAD THE AREA...EXPECT TEMPERATURES TO CLIMB INTO THE 60S AREA
WIDE...SETTING RECORD HIGH TEMPERATURES FOR THE DAY AND ALSO SETTING
UP A MARGINALLY UNSTABLE AIRMASS OVER PARTS OF THE AREA BY THIS
EVENING.
THIS WILL ALLOW ONGOING STRONG TO LOCALLY SEVERE CONVECTIVE LINE
SEGMENTS FROM WESTERN INDIANA AND SOUTHEAST ILLINOIS TO WORK INTO
THE AREA EARLY THIS EVENING. THERE WILL MOST LIKELY BE A SLIGHT
WEAKENING TREND ONCE THIS ACTIVITY ENCROACHES ON THE AREA AS THE
AIRMASS STILL WILL NOT BE QUITE A UNSTABLE AS THE CURRENT AIR
FEEDING INTO ONGOING STORMS TO THE SOUTHWEST. THIS WILL RESULT IN
GUSTY WINDS WITH LOCALLY DAMAGING WIND GUSTS STILL POSSIBLE WITHIN
THE STRONGEST PORTIONS OF THE CONVECTIVE LINE(S) THAT MAKE IT THIS
FAR NORTHEAST.
WHILE A LOW LIKELIHOOD...AN ISOLATED TORNADO STILL CANNOT BE RULED
OUT GIVEN THE STRONG LOW LEVEL SHEAR THAT WILL BE IN PLACE ONCE THIS
ACTIVITY PROPAGATES INTO THE AREA. BY AND LARGE THE MOST LIKELY
SEVERE WEATHER SCENARIO WILL BE ISOLATED POCKETS OF 60 MPH WIND
GUSTS CAUSING SOME DAMAGE AS CONVECTION TAPS INTO THE 60+ KNOT LOW
LEVEL FLOW AND BRINGS SOME OF IT TO THE SURFACE AT TIMES.
ADDITIONAL SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE FROM MID
EVENING INTO THE OVERNIGHT AS THE WARM AND MOIST AIRMASS REMAINS IN
PLACE AND EVEN BUILDS SLIGHTLY IN ADVANCE OF APPROACHING COLD FRONT
WHICH WILL CROSS THE AREA ROUGHLY BETWEEN 06Z-09Z. WITH THE SURFACE
LOW TRACK SO FAR TO THE NORTHWEST...BEST PUNCH OF WIND ALONG AND
BEHIND THIS FRONT WILL BE FOCUSED OVER THE NORTHERN CWA...AND WILL
LIMIT THE EXPECT WIND ADVISORY TO AREAS GENERALLY ALONG AND NORTH OF
INTERSTATE 69. THIS ADVISORY WILL BE RATHER SHORT LIVED AS WELL AS
THE RAPID MOVEMENT OF THE LOW INTO CANADA WILL ALLOW WINDS TO RELAX
RATHER QUICKLY THURSDAY MORNING.
MUCH QUIETER WEATHER WILL SET UP FOR THURSDAY AND FRIDAY AS HIGH
PRESSURE BUILDS EAST ACROSS THE AREA. WITH ONLY A MINOR INCURSION OF
COLDER POLAR AIR INTO AREA BEHIND THIS SYSTEM...TEMPERATURES...WHILE
COOLER...WILL REMAIN ABOVE AVERAGE FOR LATE DECEMBER. EXPECT HIGHS
IN THE 40S TO AROUND 50 THURSDAY AND IN THE 40S FRIDAY.
SURFACE LOW DEVELOPING NORTHEASTWARD ALONG BAROCLINIC ZONE PROGGED
TO MOVE THROUGH SE MI SAT. PLENTY OF MOISTURE TO BE LIFTED OVER THE
FRONTAL ZONE /PWAT NEAR 1.50 IN/ WILL SPELL LIKELY RAIN SAT/SAT
NIGHT AND POSSIBLY LINGERING INTO SUNDAY. THE RAIN COULD BE HEAVY
OVER THE SOUTH IF THE FRONT STAYS RELATIVELY STATIONARY AS SOME NWP
IS DEPICTING. THIS SHOULD BE MOSTLY RAIN BUT COULD BRIEFLY END AS
SNOW SAT NIGHT/SUN. ACCUMULATIONS DO NOT LOOK LIKELY AS THE MAJORITY
OF THE PRECIP WILL BE ON THE WARM SIDE. ATTENTION THEN TURNS TO
STRONG CUTOFF LOW EJECTING NWD FROM TX TO THE GREAT LAKES MON/TUE.
STILL SIGNIFICANT INTERMODEL AND RUN-TO-RUN MODEL DIFFERENCES IN
TIMING AND LOW TRACK...BUT ENOUGH CONFIDENCE TO GO WITH LIKELY POPS
CENTERED AROUND MONDAY NIGHT. P TYPE WILL BE TRICKY AND WILL NOT GET
TOO CUTE WITH THE DETAILS THIS FAR OUT. POTENTIAL DOES EXIST FOR
FZRA ON THE LEADING EDGE OF THE PRECIP. THE MOST LIKELY TIME FRAME
FOR THIS IS MONDAY NIGHT BEFORE WE GET INTO THE WARM SECTOR ON
TUESDAY AS DEPICTED BY THE EURO. MEANWHILE THE GFS HAS CONTINUED TO
TREND EASTWARD WITH THE LOW WHICH WOULD OPEN THE DOOR FOR SNOW FOR
PORTIONS OF OUR AREA. DUE TO MODEL DIFFERENCES AND LONG TIME
HORIZON...KEPT BROADBRUSH RAIN/SNOW MENTION FOR NOW.
MARINE...
A STRONG LOW PRESSURE SYSTEM WILL CONTINUE TO STRENGTHEN AS IT
TRACKS NORTH THROUGH THE WESTERN GREAT LAKES OVERNIGHT REACHING
JAMES BAY BY THURSDAY MORNING. THE LOW WILL PULL A COLD FRONT
THROUGH THE EASTERN GREAT LAKES LATE TONIGHT AROUND 09Z. STRONG
WINDS WILL OCCUR BOTH AHEAD OF...AND BEHIND THE COLD FRONT LEADING
TO A LONG DURATION GALE EVENT ACROSS LAKE HURON. THIS EVENING AHEAD
OF THE FRONT...ALREADY GUSTY WINDS WILL BE ENHANCED BY PREFRONTAL
RAIN SHOWERS MIXING DOWN STRONGER WINDS ALOFT MAINLY ACROSS NORTHERN
LAKE HURON. WINDS WILL THEN TURN WESTERLY AND INCREASE FURTHER AS A
TIGHT PRESSURE GRADIENT SOUTH OF THE LOW CENTER LIFTS UP THROUGH THE
REGION. WIND GUSTS WILL REACH STRONG GALE FORCE AROUND 45 KNOTS OVER
NORTHERN LAKE HURON. THE SOUTHERN END OF THE BASIN WILL BE FURTHER
REMOVED FROM THE TIGHTEST GRADIENT BUT SHOULD STILL SEE GALE FORCE
GUSTS OF 35 TO 40 KNOTS LATE TONIGHT INTO THURSDAY MORNING. WINDS
WILL THEN DIMINISH THROUGH THE DAY THURSDAY AS THE LOW QUICKLY LIFTS
NORTHWARD AWAY FROM THE LAKES. WIND GUSTS ARE EXPECTED TO DROP BELOW
20 KNOTS BY 06Z FRIDAY.
HYDROLOGY...
A LOW PRESSURE SYSTEM CURRENTLY OVER IOWA WILL CONTINUE TO
STRENGTHEN AS IT LIFTS NORTH THROUGH THE OVERNIGHT...REACHING JAMES
BAY BY THURSDAY MORNING. VERY WARM AND MOIST AIR LIFTING INTO THE
AREA AHEAD OF THE COLD FRONT WILL RESULT IN GOOD COVERAGE OF RAIN
SHOWERS THIS EVENING WITH ISOLATED THUNDERSTORMS POSSIBLE. MOST
LOCATIONS WILL RECEIVE AROUND 0.5 INCH OF RAIN BY THURSDAY MORNING
WITH ISOLATED TOTALS OF AROUND 1.0 INCH. LITTLE CONCERN FOR FLOODING
EXISTS.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 10 AM EST THURSDAY FOR MIZ047>049-053>055-
060>063-068>070-075-076-082-083.
LAKE HURON...GALE WARNING FROM 3 AM TO NOON EST THURSDAY FOR LHZ421-422-441-462.
GALE WARNING FROM 4 AM TO 10 AM EST THURSDAY FOR LHZ442-443-463-464.
GALE WARNING UNTIL 3 PM EST THURSDAY FOR LHZ361>363.
LAKE ST CLAIR...SMALL CRAFT ADVISORY UNTIL 10 AM EST THURSDAY FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...SMALL CRAFT ADVISORY UNTIL 10 AM EST THURSDAY FOR LEZ444.
&&
$$
UPDATE.......BT
AVIATION.....BT
DISCUSSION...DG/DT
MARINE.......DRK
HYDROLOGY....DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
713 PM EST WED DEC 23 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 440 PM EST WED DEC 23 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD TROUGH OVER THE WRN
CONUS AND A RIDGE FROM THE WRN ATLANTIC INTO NEW ENGLAND RESULTING
IN SSW FLOW FROM THE SRN PLAINS INTO THE WRN GREAT LAKES. A VIGOROUS
SHORTWAVE TROUGH OVER CNTRL IA WAS LIFTING QUICKLY TO THE NORTHEAST.
AT THE SFC...A 983 MB LOW WAS LOCATED OVER ERN IA WITH A WARM FRONT
TO THE EAST THROUGH SRN LAKE MI. AN AREA OF RAIN OVER UPPER MI AND
NE WI SUPPORTED BY 295K-300K ISENTROPIC LIFT AHEAD OF THE SHRTWV AND
WARM FRONT WAS LIFTING TO THE NNE. TO THE WEST...SNOW OVER NE MN
INTO NW WI WAS ASSOCIATED WITH A BAND OF 850-700 MB
FGEN/DEFORMATION.
TONIGHT...AFTER THE FIRST BATCH OF PCPN MOVES OUT OF THE CNTRL AND
EAST...THE AREA OF FGEN AND 700-300 MB QVECTOR CONV AHEAD OF THE
SHRTWV WILL BRING MORE PCPN THROUGH UPPER MICHIGAN. AS THE TROUGH
AND COLD FRONT NEAR IWD AND 00Z MOVES TO THE NEAR MQT-IMT BY 06Z AND
ERY AROUND 09Z THE RAIN WILL CHANGE TO SNOW. HOWEVER...THE HEAVIEST
PCPN...AS RAIN...IS EXPECTED BEFORE THE COLD AIR MOVES IN. THE
EXCEPTION WILL BE OVER THE FAR WEST (NEAR IWD) WHERE 1 TO 4 INCHES
WILL BE POSSIBLE AND A WINTER WX WAS ISSUED. OTHERWISE...ANY
ACUMULATIONS WILL AMOUNT TO AN INCH OR LESS.
THE OTHER MAIN CONCERN IS THE POTENTIAL FOR STRONG WINDS OVERNIGHT.
AS THE FRONT LIFTS THROUGH A VERY STRNOG ISALLOBARIC COMPONENT WITH
12 MB/3HR PRES RISE WILL BRING VERY GUSTY WINDS TO ESPECIALLY THE
ERN CWA BTWN 06Z-12 WHERE A WIND ADVY IS IN EFFECT. WRLY WINDS WILL
ALSO BE VERY GUSTY OVER THE KEWEENAW WHERE 925 MB WINDS TO 50 KT ARE
FCST.
THURSDAY...A THE STORNG PRES GRADIENT WILL CONTINUE TO BRING GUSTY
WINDS TO UPPER MICHIGAN DURING THE MORNING. THE ADVY WAS MAINTAINED
TIL 21Z OVER THE KEWEENAW GIVEN THE FAVORABLE EXPOSURE TO THE STRONG
WEST WINDS THROUGH MID AFTERNOON. 850 MB TEMPS TO AROUND -8C WILL
ALSO SUPPORT ADDITIONAL LAKE ENHANCED SNOW INTO THE KEWEENAW AS THE
DEEPER WRAP-AROUND MOISTURE LINGERS.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 342 PM EST WED DEC 23 2015
SURFACE LOW WILL CONTINUE TO LIFT PRETTY QUICKLY NORTHEASTWARD INTO
QUEBEC THURSDAY EVENING WITH SURFACE RIDGING BUILDING ACROSS THE
GREAT LAKES FOR CHRISTMAS EVE NIGHT AND THROUGH THE DAY ON
CHRISTMAS. WINDS WILL DIMINISH THURSDAY EVENING WITH A PRETTY
TRANQUIL CHRISTMAS DAY EXPECTED ACROSS THE UP. WITH SOME SUNSHINE
TEMPERATURES WILL CLIMB INTO THE LOWER AND MIDDLE 30S...ABOUT 5 TO
10 DEGREES ABOVE AVERAGE.
ATTENTION WILL THEN TURN TO NORTHERN STREAM UPPER TROUGHING MOVING
EASTWARD ALONG THE CANADIAN BORDER TOWARDS THE UPPER GREAT LAKES
ALONG WITH SHORT WAVE ENERGY LIFTING NORTHEASTWARD FROM THE
DEVELOPING CLOSED LOW OVER THE FOUR CORNERS REGION. MODELS CONTINUE
SHOW A SIGNIFICANT AMOUNT OF UNCERTAINTY STILL WITH THE
PRECIPITATION. GFS AND ECMWF SEEM TO BE MOST CONSISTENT WITH SHOWING
BEST WARM ADVECTION AND FRONTOGENESIS ACROSS THE AREA ON SATURDAY
YIELDING A MARGINAL ADVISORY SNOWFALL FOR THE CENTRAL AND WESTERN UP
WITH SNOW AMOUNTS IN THE 2-4 INCH RANGE WITH LOCALLY HIGHER AMOUNTS
IN THE UPSLOPE AREAS FAVORED BY NORTHEAST WINDS. NAM AND GEM TO A
LESSER EXTENT STILL MORE SHEARED OUT AND KEEP STRONGEST FORCING
SOUTH AND EAST OF THE AREA.
HIGH PRESSURE WITH SEASONABLE TEMPERATURES WILL BUILD BACK ACROSS
THE AREA FOR THE SUNDAY INTO MONDAY TIME PERIOD. 85H TEMPERATURES
WILL BE MARGINAL FOR LIGHT NORTH TO NORTHWEST WIND LAKE EFFECT
SATURDAY NIGHT INTO SUNDAY BUT ANY ACCUMULATIONS WILL BE LIGHT.
MAIN UPPER LOW WILL BEGIN TO EJECT OUT OF THE SOUTHWEST EARLY NEXT
WEEK WITH VARYING SOLUTIONS ON THE TRACK OF THE SURFACE LOW. ECMWF
MOST WOUND UP WITH A TRACK MORE FAVORABLE FOR ACCUMULATING SNOW FOR
MUCH OF THE AREA. GFS IS FARTHER SOUTH AND EAST SUGGESTING ANY
SIGNIFICANT PRECIPITATION STAYS SOUTH AND EAST OF THE AREA. DETAILS
WILL BE RESOLVED OVER THE COMING DAYS WITH A MODEL BLEND THE BEST
COURSE OF ACTION AT THIS TIME.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 711 PM EST WED DEC 23 2015
LIFR TO VLIFR CONDITIONS ARE EXPECTED TO PERSIST INTO THIS EVENING
AS VERY MOIST LOW LEVEL AIR REMAINS OVER THE REGION WITH S-SE FLOW
AND LIGHT PCPN. LLWS IS EXPECTED AT SAW TONIGHT WITH A STRONG SW
LOW LEVEL JET ABOVE THE MAINLY DECOUPLED SFC WINDS. RAIN WILL CHANGE
OVER TO SNOW FROM WEST TO EAST THIS EVENING AND OVERNIGHT. GUSTY
WEST WINDS WILL DEVELOP LATE TONIGHT AT IWD/CMX AND THU MORNING AT
SAW AS THE STRONG LOW LIFTS TO THE NORTH OF THE REGION. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 440 PM EST WED DEC 23 2015
SIGNIFICANT WIND EVENT WILL OCCUR TONIGHT INTO THURSDAY ACROSS THE
WATERS AND THE WIND WILL INCREASE RAPIDLY LATE TONIGHT. A TIGHT
PRESSURE GRADIENT LATE TONIGHT COMBINED WITH A STRONG PRESSURE RISE
OF 12 MB IN THREE HOURS OVER LAKE MICHIGAN WILL CAUSE STORM FORCE
WINDS ACROSS EASTERN LAKE SUPERIOR AND NORTHERN LAKE MICHIGAN LATE
TONIGHT INTO THURSDAY AND A HIGH END GALE ACROSS THE WEST HALF OF
LAKE SUPERIOR. ONCE THIS EVENT ENDS THURSDAY AFTERNOON...WINDS LOOK
TO STAY BELOW 30 KNOTS THROUGH THE REST OF THE PERIOD.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND ADVISORY FROM 3 AM EST /2 AM CST/ TO 1 PM EST /NOON CST/
THURSDAY FOR MIZ007-012>014-085.
WIND ADVISORY FROM 5 AM TO 4 PM EST THURSDAY FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 4 AM CST THURSDAY FOR MIZ009.
LAKE SUPERIOR...
STORM WARNING FROM 5 AM TO 7 PM EST THURSDAY FOR LSZ265>267.
GALE WARNING FROM 3 AM EST /2 AM CST/ TO 7 PM EST /6 PM CST/
THURSDAY FOR LSZ162-240>245-263-264.
GALE WARNING FROM 5 AM TO 7 PM EST THURSDAY FOR LSZ246>251.
LAKE MICHIGAN...
STORM WARNING FROM 1 AM TO NOON EST THURSDAY FOR LMZ221-248-250.
GALE WARNING FROM NOON TO 5 PM EST THURSDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...MZ
AVIATION...VOSS
MARINE...JLB
AREA FORECAST DISCUSSION
NWS JACKSON MS
414 PM CST TUE DEC 22 2015
...SIGNIFICANT SEVERE WEATHER POSSIBLE ON WEDNESDAY...
.DISCUSSION...WIDESPREAD STRATUS CONTINUE TO MAINTAIN GRIP OVER THE
AREA THIS AFTERNOON. A FEW BREAKS WERE NOTED ON VISIBLE SAT,
ALLOWING A FEW LOCATIONS TO WARM INTO THE LOWER 70S. HOWEVER, MOST
SITES REMAINED IN THE MID TO UPPER 60S AS OF 21Z. THE ENVIRONMENT WAS
ALREADY RATHER MOIST, WITH DEWPOINTS IN THE MID TO UPPER 60S
AREAWIDE. CONSIDERABLE GULF COASTAL CONVECTION HAS DEVELOPED TODAY
IN THE INTERFACE BETWEEN A RIGHT ENTRANCE REGION OF THE POLAR JET
AND LEFT EXIT REGION OF THE SUBTROPICAL JET. SOME OF THIS ACTIVITY
HAS ALREADY BEGUN WORKING INTO SE MISSISSIPPI, WITH ADDITIONAL
CONVECTION EXPECTED TO LIFT MAINLY INTO SOUTHEASTERN PORTIONS OF THE
CWA THROUGH THE EVENING.
LOOKING BACK TO THE WEST, U/A ANALYSIS SHOWS A DIP IN THE POLAR JET
OVER THE ROCKY MTNS WHICH IS LEADING TO A DEVELOPING LEESIDE LOW
OVER THE SOUTHERN HIGH PLAINS. AS AN UPPER JET MAX CURRENTLY
EXTENDING FROM OREGON THROUGH NV/UT/AZ ENTERS THE BASE OF THIS
TROUGH, IT WILL TAKE ON A NEGATIVE TILT EARLY WED MORNING OVER THE
PLAINS AS THE SURFACE LOW TRACKS NEWD THROUGH THE MISSOURI VALLEY
TOWARD THE GREAT LAKES THROUGH THE DAY. EARLY WED MORNING, AS THE
COASTAL CONVECTION BEGINS TO LIFT INLAND, THIS WILL USHER IN A SURGE
OF LOW LEVEL MOISTURE/THETA-E THROUGH THE DAY. SOME HIGH RES GUIDANCE
SUGGESTS SCATTERED CONVECTION WILL BE ONGOING AROUND DAYBREAK ON THE
NOSE OF THIS MOISTURE/INSTABILITY SURGE. WHILE THIS CONVECTION WOULD
LIKELY BE ELEVATED, RESPECTABLE FORECAST MID LEVEL LAPSE RATES
SUGGEST LARGE HAIL IS POSSIBLE DURING THE MORNING WITH ANY ACTIVITY
LIFTING NORTHWARD ACROSS THE REGION.
THERE MAY BE A BIT OF A BREAK IN THE ACTION BETWEEN NORTHWARD MOVING
MORNING ACTIVITY AND MORE SUBSTANTIAL DEVELOPMENT DURING THE
AFTERNOON AS A WEAK CAPPING INVERSION HOLDS OFF SURFACE BASED
DEVELOPMENT FOR A WHILE. THEN BY THE AFTERNOON, BETTER UPPER HEIGHT
FALLS AND DECENT MID LEVEL LAPSE RATES WILL OVERLAY DEWPOINTS IN THE
UPPER 60S TO NEAR 70 AND MLCAPES IN THE 1000-2000 J/KG RANGE (IF NOT
HIGHER AS SUGGESTED BY SOME HIGH-RES GUIDANCE). EVEN WITH
CONSIDERABLE CLOUD COVER, WAA AND LIMITED INSOLATION SHOULD BE
SUFFICIENT TO BREAK THE CAP, ALLOWING SCATTERED SUPERCELLS TO DEVELOP
IN AN ENVIRONMENT CHARACTERIZED BY DEEP LAYER SHEAR OF 50-70 KT AND
EFFECTIVE SR HELICITY VALUES IN THE 200-400 M2/S2 RANGE. ALL MODES OF
SEVERE WX WILL BE POSSIBLE, INCLUDING TORNADOES. THE SREF SIG TOR
INGREDIENTS PARAMETER ALSO SUGGESTS SOME STRONG TORNADOES ARE
POSSIBLE, PARTICULARLY OVER THE NORTHERN HALF OF THE CWA. AT THIS
TIME, OUR AREA OF GREATEST CONCERN IS AN AREA ROUGHLY NORTH OF A LINE
FROM RAYVILLE LA TO YAZOO CITY TO MACON, AS THIS IS WHERE THE BEST
UPPER SUPPORT (HEIGHT FIELD/HEIGHT FALLS/PROXIMITY TO PASSING
SHORTWAVE) WILL EXIST. CONFIDENCE IN SEVERE WEATHER IS LOWER SOUTH OF
THIS LINE, BUT THE THREAT CERTAINLY STILL EXISTS.
HEADING LATER INTO THE NIGHT AND EARLY MORNING HOURS THURSDAY, THE
SEVERE THREAT BECOMES MORE QUESTIONABLE AS UPPER HEIGHTS AND SURFACE
PRESSURES BEGIN TO RISE. HOWEVER THERE WILL REMAIN A SURGE OF LOW
LEVEL INSTABILITY AND LINGERING LOW LEVEL SHEAR ACROSS MAINLY EASTERN
MS, SO THERE IS SOME POSSIBILITY SEVERE COULD CONTINUE WELL INTO THE
OVERNIGHT.
A SECONDARY CONCERN THAT MAY REQUIRE MONITORING IS HEAVY RAINFALL
POTENTIAL. RECENT RUNS OF THE NAM HAVE POINTED TO SOME POTENTIAL FOR
CORRIDORS OF TRAINING STORMS. WHILE THIS IS NOT REFLECTED IN THE
LARGER SCALE QPF, WHICH AVERAGES OUT WITH AREAS RECEIVING MUCH LESS
RAIN, THIS WILL BE ANOTHER POTENTIAL HAZARD TO MONITOR WEDNESDAY INTO
EARLY THURSDAY.
AN ACTIVE WEATHER PATTERN WILL CONTINUE INTO THE END OF THE WEEK AS
THE POLAR JET REMAINS NORTH OF THE AREA AND NO FROPA OCCURS WITH THE
MIDWEEK SYSTEM. THOUGH THERE WILL BE A BRIEF DROP OFF IN COLUMN
MOISTURE ACROSS MUCH OF THE AREA ALONG A PREFRONTAL TROUGH (EXCEPT
THE PINE BELT WHERE POSITIVE PW ANOMALIES WILL REMAIN), LOW LEVEL
FLOW WILL QUICKLY BRING A RETURN OF 1.5-2 INCH PW ACROSS MUCH OF THE
AREA THURSDAY INTO CHRISTMAS DAY. RELEVANT PORTIONS OF THE PREVIOUS
LONG TERM FOLLOW BELOW... /DL/
MODEL CONSENSUS HAS THE BOUNDARY JUST NORTHWEST OF OUR CWA BY NOON
FRIDAY RESULTING IN PWATS GREATER THAN AN INCH AND A HALF OVER OUR
WHOLE CWA. GREATEST POPS WL BE CARRIED OVER OUR NORTHWEST ZONES
FRIDAY BUT THERE WL BE A CHANCE FOR RAIN AREAWIDE. THE DEEPENING
TROUGH OVER THE WESTERN CONUS WILL CLOSE OFF OVER THE DESERT
SOUTHWEST BY SATURDAY MORNING AND SWING EAST TO THE TEXAS BIG BEND
REGION BY SUNDAY MORNING. THE MODELS BEGIN TO DIVERGE WITH THE TRACK
OF THE CLOSED LOW SUNDAY INTO TUESDAY WITH THE GFS BEING THE MOST
PROGRESSIVE AND FASTEST BRINGING THE ASSOCIATED COLD FRONT ACROSS OUR
CWA SUNDAY NIGHT. THE ECMWF IS THE SLOWEST WITH THE CLOSED LOW AND
BRINGS THE ASSOCIATED CLOD FRONT THROUGH OUR CWA MONDAY NIGHT. BOTH
MODELS AGREE THAT WARMER THAN NORMAL TEMPERATURES WITH MOSTLY
DIURNALLY DRIVEN RAIN CHANCES WILL CONTINUE OVER OUR CWA THROUGH THE
WEEKEND. HAVE USED A BLEND AND LEANED TOWARD A LITTLE SLOWER FROPA IN
LINE WITH CONSENSUS FROM MONDAY`S RUNS WITH MONDAY BEING THE MAIN
RAIN DAY. THERE STILL REMAIN INDICATION OF SOME POTENTIAL FOR SEVERE
STORMS ALONG AND AHEAD OF THE FRONT. /22/
&&
.AVIATION...LATEST HRRR GUIDANCE INDICATES AT LEAST IFR IF NOT LIFR
STRATUS WILL REMAIN THROUGH TONIGHT. SHRA/TSRA CHANCES WILL INITIALLY
INCREASE OVER THE MEI/PIB AREA THIS AFTN...AND THEN INCREASE LATE
TONIGHT OVER THE REMAINING AREA AS SOUTHERLY FLOW RAPIDLY
STRENGTHENS. SEVERE TSRA WILL BE POSSIBLE WED INTO WED EVNG. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 64 76 65 77 / 50 81 48 44
MERIDIAN 63 75 68 77 / 76 72 62 59
VICKSBURG 65 77 64 77 / 52 77 36 28
HATTIESBURG 64 77 70 78 / 86 67 60 58
NATCHEZ 66 78 64 78 / 60 75 32 35
GREENVILLE 65 75 60 74 / 51 86 33 13
GREENWOOD 65 77 62 77 / 41 85 44 22
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/EC/22
AREA FORECAST DISCUSSION
NWS JACKSON MS
413 PM CST TUE DEC 22 2015
...SIGNIFICANT SEVERE WEATHER POSSIBLE ON WEDNESDAY...
.DISCUSSION...WIDESPREAD STRATUS CONTINUE TO MAINTAIN GRIP OVER THE
AREA THIS AFTERNOON. A FEW BREAKS WERE NOTED ON VISIBLE SAT,
ALLOWING A FEW LOCATIONS TO WARM INTO THE LOWER 70S. HOWEVER, MOST
SITES REMAINED IN THE MID TO UPPER 60S AS OF 21Z. THE ENVIRONMENT WAS
ALREADY RATHER MOIST, WITH DEWPOINTS IN THE MID TO UPPER 60S
AREAWIDE. CONSIDERABLE GULF COASTAL CONVECTION HAS DEVELOPED TODAY IN
THE INTERFACE BETWEEN A RIGHT ENTRACE REGION OF THE POLAR JET AND
LEFT EXIT REGION OF THE SUBTROPICAL JET. SOME OF THIS ACTIVITY HAS
ALREADY BEGUN WORKING INTO SE MISSISSIPPI, WITH ADDITIONAL CONVECTION
EXPECTED TO LIFT MAINLY INTO SOUTHEASTERN PORTIONS OF THE CWA
THROUGH THE EVENING.
LOOKING BACK TO THE WEST, U/A ANALYSIS SHOWS A DIP IN THE POLAR JET
OVER THE ROCKY MTNS WHICH IS LEADING TO A DEVELOPING LEESIDE LOW
OVER THE SOUTHERN HIGH PLAINS. AS AN UPPER JET MAX CURRENTLY
EXTENDING FROM OREGON THROUGH NV/UT/AZ ENTERS THE BASE OF THIS
TROUGH, IT WILL TAKE ON A NEGATIVE TILT EARLY WED MORNING OVER THE
PLAINS AS THE SURFACE LOW TRACKS NEWD THROUGH THE MISSOURI VALLEY
TOWARD THE GREAT LAKES THROUGH THE DAY. EARLY WED MORNING, AS THE
COASTAL CONVECTION BEGINS TO LIFT INLAND, THIS WILL USHER IN A SURGE
OF LOW LEVEL MOISTURE/THETA-E THROUGH THE DAY. SOME HIGH RES GUIDANCE
SUGGESTS SCATTERED CONVECTION WILL BE ONGOING AROUND DAYBREAK ON THE
NOSE OF THIS MOISTURE/INSTABILITY SURGE. WHILE THIS CONVECTION WOULD
LIKELY BE ELEVATED, RESPECTABLE FORECAST MID LEVEL LAPSE RATES
SUGGEST LARGE HAIL IS POSSIBLE DURING THE MORNING WITH ANY ACTIVITY
LIFTING NORTHWARD ACROSS THE REGION.
THERE MAY BE A BIT OF A BREAK IN THE ACTION BETWEEN NORTHWARD MOVING
MORNING ACTIVITY AND MORE SUBSTANTIAL DEVELOPMENT DURING THE
AFTERNOON AS A WEAK CAPPING INVERSION HOLDS OFF SURFACE BASED
DEVELOPMENT FOR A WHILE. THEN BY THE AFTERNOON, BETTER UPPER HEIGHT
FALLS AND DECENT MID LEVEL LAPSE RATES WILL OVERLAY DEWPOINTS IN THE
UPPER 60S TO NEAR 70 AND MLCAPES IN THE 1000-2000 J/KG RANGE (IF NOT
HIGHER AS SUGGESTED BY SOME HIGH-RES GUIDANCE). EVEN WITH
CONSIDERABLE CLOUD COVER, WAA AND LIMITED INSOLATION SHOULD BE
SUFFICIENT TO BREAK THE CAP, ALLOWING SCATTERED SUPERCELLS TO DEVELOP
IN AN ENVIRONMENT CHARACTERIZED BY DEEP LAYER SHEAR OF 50-70 KT AND
EFFECTIVE SR HELICITY VALUES IN THE 200-400 M2/S2 RANGE. ALL MODES OF
SEVERE WX WILL BE POSSIBLE, INCLUDING TORNADOES. THE SREF SIG TOR
INGREDIENTS PARAMETER ALSO SUGGESTS SOME STRONG TORNADOES ARE
POSSIBLE, PARTICULARLY OVER THE NORTHERN HALF OF THE CWA. AT THIS
TIME, OUR AREA OF GREATEST CONCERN IS AN AREA ROUGHLY NORTH OF A LINE
FROM RAYVILLE LA TO YAZOO CITY TO MACON, AS THIS IS WHERE THE BEST
UPPER SUPPORT (HEIGHT FIELD/HEIGHT FALLS/PROXIMITY TO PASSING
SHORTWAVE) WILL EXIST. CONFIDENCE IN SEVERE WEATHER IS LOWER SOUTH OF
THIS LINE, BUT THE THREAT CERTAINLY STILL EXISTS.
HEADING LATER INTO THE NIGHT AND EARLY MORNING HOURS THURSDAY, THE
SEVERE THREAT BECOMES MORE QUESTIONABLE AS UPPER HEIGHTS AND SURFACE
PRESSURES BEGIN TO RISE. HOWEVER THERE WILL REMAIN A SURGE OF LOW
LEVEL INSTABILITY AND LINGERING LOW LEVEL SHEAR ACROSS MAINLY EASTERN
MS, SO THERE IS SOME POSSIBILITY SEVERE COULD CONTINUE WELL INTO THE
OVERNIGHT.
A SECONDARY CONCERN THAT MAY REQUIRE MONITORING IS HEAVY RAINFALL
POTENTIAL. RECENT RUNS OF THE NAM HAVE POINTED TO SOME POTENTIAL FOR
CORRIDORS OF TRAINING STORMS. WHILE THIS IS NOT REFLECTED IN THE
LARGER SCALE QPF, WHICH AVERAGES OUT WITH AREAS RECEIVING MUCH LESS
RAIN, THIS WILL BE ANOTHER POTENTIAL HAZARD TO MONITOR WEDNESDAY INTO
EARLY THURSDAY.
AN ACTIVE WEATHER PATTERN WILL CONTINUE INTO THE END OF THE WEEK AS
THE POLAR JET REMAINS NORTH OF THE AREA AND NO FROPA OCCURS WITH THE
MIDWEEK SYSTEM. THOUGH THERE WILL BE A BRIEF DROP OFF IN COLUMN
MOISTURE ACROSS MUCH OF THE AREA ALONG A PREFRONTAL TROUGH (EXCEPT
THE PINE BELT WHERE POSITIVE PW ANOMALIES WILL REMAIN), LOW LEVEL
FLOW WILL QUICKLY BRING A RETURN OF 1.5-2 INCH PW ACROSS MUCH OF THE
AREA THURSDAY INTO CHRISTMAS DAY. RELEVANT PORTIONS OF THE PREVIOUS
LONG TERM FOLLOW BELOW... /DL/
MODEL CONSENSUS HAS THE BOUNDARY JUST NORTHWEST OF OUR CWA BY NOON
FRIDAY RESULTING IN PWATS GREATER THAN AN INCH AND A HALF OVER OUR
WHOLE CWA. GREATEST POPS WL BE CARRIED OVER OUR NORTHWEST ZONES
FRIDAY BUT THERE WL BE A CHANCE FOR RAIN AREAWIDE. THE DEEPENING
TROUGH OVER THE WESTERN CONUS WILL CLOSE OFF OVER THE DESERT
SOUTHWEST BY SATURDAY MORNING AND SWING EAST TO THE TEXAS BIG BEND
REGION BY SUNDAY MORNING. THE MODELS BEGIN TO DIVERGE WITH THE TRACK
OF THE CLOSED LOW SUNDAY INTO TUESDAY WITH THE GFS BEING THE MOST
PROGRESSIVE AND FASTEST BRINGING THE ASSOCIATED COLD FRONT ACROSS OUR
CWA SUNDAY NIGHT. THE ECMWF IS THE SLOWEST WITH THE CLOSED LOW AND
BRINGS THE ASSOCIATED CLOD FRONT THROUGH OUR CWA MONDAY NIGHT. BOTH
MODELS AGREE THAT WARMER THAN NORMAL TEMPERATURES WITH MOSTLY
DIURNALLY DRIVEN RAIN CHANCES WILL CONTINUE OVER OUR CWA THROUGH THE
WEEKEND. HAVE USED A BLEND AND LEANED TOWARD A LITTLE SLOWER FROPA IN
LINE WITH CONSENSUS FROM MONDAY`S RUNS WITH MONDAY BEING THE MAIN
RAIN DAY. THERE STILL REMAIN INDICATION OF SOME POTENTIAL FOR SEVERE
STORMS ALONG AND AHEAD OF THE FRONT. /22/
&&
.AVIATION...LATEST HRRR GUIDANCE INDICATES AT LEAST IFR IF NOT LIFR
STRATUS WILL REMAIN THROUGH TONIGHT. SHRA/TSRA CHANCES WILL INITIALLY
INCREASE OVER THE MEI/PIB AREA THIS AFTN...AND THEN INCREASE LATE
TONIGHT OVER THE REMAINING AREA AS SOUTHERLY FLOW RAPIDLY
STRENGTHENS. SEVERE TSRA WILL BE POSSIBLE WED INTO WED EVNG. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 64 76 65 77 / 50 81 48 44
MERIDIAN 63 75 68 77 / 76 72 62 59
VICKSBURG 65 77 64 77 / 52 77 36 28
HATTIESBURG 64 77 70 78 / 86 67 60 58
NATCHEZ 66 78 64 78 / 60 75 32 35
GREENVILLE 65 75 60 74 / 51 86 33 13
GREENWOOD 65 77 62 77 / 41 85 44 22
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/EC/22
AREA FORECAST DISCUSSION...CORRECTED
NWS JACKSON MS
1053 AM CST TUE DEC 22 2015
...CONFIDENCE INCREASING IN SEVERE WEATHER THREAT ON WEDNESDAY...
.DISCUSSION...BUSY MORNING IN THE WX OFFICE WITH MUCH TO DISCUSS.
FIRST THINGS FIRST, THE DENSE FOG ADVISORY WAS ALLOWED TO EXPIRE.
VISIBILITY AT ALMOST ALL SITES HAS IMPROVED TO ABOVE 1/4, WITH THE
LAST EXCEPTIONS BEING OUR TWO SITES IN JONES COUNTY. STILL,
CONSIDERABLE FOG AND LOW STRATUS REMAIN ACROSS MOST OF THE CWA, SO
THIS WAS ADDED TO THE FORECAST FOR THE REMAINDER OF THE MORNING. THE
FOG AND LOW CLOUDS ARE STUNTING TEMP RISES ACROSS THE AREA, AND THUS
MAX TEMPS HAVE BEEN ADJUSTED DOWNWARD ACCORDINGLY ACROSS THE ENTIRE
CWA.
NOW, LOOKING AHEAD TO WED...MODELS CONTINUE TO SHOW AN IMPRESSIVE
COMBINATION OF SHEAR AND INSTABILITY AHEAD OF AN APPROACHING STORM
SYSTEM. WHILE MORE SUBTLE HEIGHT FALLS MAY WELL PRECLUDE MORE
WIDESPREAD CONVECTION THROUGH THE EVENT, CURRENT PARAMETER SPACING
SUGGESTS THAT THE STORMS THAT DO DEVELOP COULD GET RATHER NASTY.
CURRENT THINKING IS THE WINDOW OF GREATEST CONCERN WILL BE THE
AFTERNOON AND EARLY EVENING WED OVER NORTHERN PORTIONS OF THE
CWA...WHEN MID/UPPER HEIGHT FALLS WILL BE GREATEST AND SURFACE BASED
PARCELS WILL BE MOST LIKELY TO OVERCOME THE CAP. AT THAT POINT,
SCATTERED SUPERCELL DEVELOPMENT LOOKS QUITE POSSIBLE. ALSO OF
NOTE...RECENT HIGH RES GUIDANCE RUNS SUGGEST THE POTENTIAL FOR
ELEVATED CONVECTION EARLIER IN THE MORNING, WITH POTENTIAL FOR LARGE
HAIL ACROSS SOUTHERN PORTIONS OF THE CWA.
AGAIN...WHILE THERE REMAIN SOME QUESTIONS ABOUT COVERAGE/HOW
WIDESPREAD OF AN AREA WILL BE IMPACTED, THE POTENTIAL FOR HIGHER END
SEVERE WX, INCLUDING POSSIBLY A COUPLE STRONG TORNADOES, WARRANTS A
CATEGORY INCREASE IN SEVERE WEATHER POTENTIAL IN OUR HWO/GRAPHICS.
WE WILL GO AHEAD AND MAKE THESE CHANGES THIS MORNING. MORE
DETAILS WILL BE COMING UP THIS AFTERNOON. /DL/
&&
.AVIATION...WHILE THERE WILL BE GRADUAL IMPROVEMENT WITH THE VSBYS
DUE TO FOG AS WE GO THROUGH THE REMAINDER OF THE MORNING INTO THE
EARLY AFTN...LATEST HRRR GUIDANCE INDICATES AT LEAST IFR IF NOT LIFR
STRATUS WILL REMAIN THROUGH TONIGHT. SHRA/TSRA CHANCES WILL
INITIALLY INCREASE OVER THE MEI/PIB AREA THIS AFTN...AND THEN
INCREASE LATE TONIGHT OVER THE REMAINING AREA AS SOUTHERLY FLOW
RAPIDLY STRENGTHENS. SEVERE TSRA WILL BE POSSIBLE WED INTO WED EVNG.
/EC/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/EC/15/22
AREA FORECAST DISCUSSION
NWS JACKSON MS
721 AM CST TUE DEC 22 2015
.UPDATE...
HAVE EXPANDED THE DENSE FOG ADVISORY TO COVER THE ENTIRE AREA BASED
ON CURRENT TRENDS AND NEAR TERM HRRR GUIDANCE WHICH BEGINS TO FOCUS
MORE DENSE FOG OVER EASTERN MS FOR THE NEXT COUPLE OF HOURS. HAVE
ALSO EXTENDED IT BY AN HOUR BASED ON THESE TRENDS. /EC/
&&
.PREV DISCUSSION... /ISSUED 516 AM CST TUE DEC 22 2015/
UPDATE...UPDATED TO INCLUDE DENSE FOG ADVISORY UNTIL 9AM FOR
PORTIONS OF EXTREME SOUTHEAST ARKANSAS...NORTHEAST LOUISIANA AND
WEST CENTRAL MISSISSIPPI. /22/
PREV DISCUSSION... /ISSUED 444 AM CST TUE DEC 22 2015/
SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT...MOST OF THE SHOWERS
HAVE DISSIPATED THIS MORNING AS THE DEEP MOISTURE HAS SHIFTED TO THE
EAST AND SOUTH OF THE AREA. PATCHY AREAS OF DENSE FOG ARE OCCURRING
AND A LIMITED POTENTIAL FOR DENSE FOG IS ALREADY IN THE HWO.
ISOLATED SHOWERS WILL CONTINUE TO BE POSSIBLE THROUGH THE MORNING
HOURS...BUT AS THE DEEP MOISTURE PUSHES BACK NORTH ACROSS THE
AREA...SHOWERS AND THUNDERSTORMS WILL ONCE AGAIN RETURN THIS
AFTERNOON THROUGH THE EVENING HOURS. HI-RES MODELS INDICATE THAT A
COMPLEX OF STORMS WILL DEVELOP OVER THE NORTH CENTRAL GULF AND MOVE
ACROSS AREAS MAINLY SOUTH OF THE NATCHEZ TRACE CORRIDOR LATER THIS
AFTERNOON THROUGH THE EVENING HOURS. LIMITED INSTABILITY AND SHEAR
WOULD SUGGEST THE ACTIVITY WILL REMAIN BELOW STRONG TO SEVERE
LIMITS...BUT WITH ALL OF THE RECENT RAINFALL SOME LOCALIZED FLOODING
MAY BE POSSIBLE.
SHOWERS AND THUNDERSTORMS WILL CONTINUE TO BE POSSIBLE
OVERNIGHT...BUT THE MAIN SHOW LOOKS TO BE ON WEDNESDAY ACROSS THE
AREA. A STRONG POLAR JET WILL DEEPEN A NEGATIVELY TILTED TROUGH
OVER THE PLAINS WITH A SURFACE LOW MOVING FROM THE CENTRAL PLAINS
INTO THE GREAT LAKES BY WEDNESDAY EVENING. THE BEST FORCING WITH
THIS SYSTEM CONTINUES TO LOOK LIKE IT WILL BE TO THE NORTH OF OUR
AREA...BUT WITHIN OUR AREA THE BEST FORCING WILL GENERALLY BE NORTH
OF THE I-20 CORRIDOR. THE NAM CONTINUES TO BE THE MOST ROBUST MODELS
FOR THE POTENTIAL FOR SEVERE WHILE THE ECMWF IS MORE BEARISH. ALL OF
THE INSTABILITY AND SHEAR PARAMETERS LOOK TO SUPPORT THE POTENTIAL
FOR SEVERE ACROSS THE AREA...BUT THE MAIN LIMITING FACTOR LOOKS TO
BE THE AMOUNT OF FORCING WITH LIMITED HEIGHT FALLS...ESPECIALLY
ALONG AND SOUTH OF OF THE I-20 CORRIDOR. THERE ARE ACTUALLY HEIGHT
RISES ACROSS THE AREA AS WE GET INTO THE LATE AFTERNOON/EARLY
EVENING HOURS. EVEN WITH THESE FACTORS ANY STORMS THAT DUE DEVELOP
WILL HAVE THE ABILITY TO BECOME SEVERE GIVEN THE INSTABILITY AND
VERY STRONG SHEAR. WITH THE CWASP SIG TOR INGREDIENTS CONTINUE TO
REMAIN VERY HIGH OVER OUR AREA...WILL UPGRADE AREAS MAINLY NORTH OF
THE I-20 CORRIDOR TO ELEVATED IN THE HWO AND GRAPHICASTS. HEAVY
RAINFALL WILL ALSO HAVE TO BE MONITORED ONCE AGAIN GIVEN THE
RAINFALL AMOUNTS THAT HAVE ALREADY BEEN RECEIVED AND WILL FALL OVER
THE NEXT COUPLE OF DAYS.
EXPECT THE SEVERE POTENTIAL TO SHIFT EAST OF THE AREA WEDNESDAY
NIGHT...BUT SHOWERS WILL CONTINUE TO BE POSSIBLE THROUGH THE NIGHT
GIVEN THE DEEP LAYER MOISTURE THAT WILL REMAIN OVER MUCH OF THE
AREA. /15/
LONG TERM...THURSDAY THROUGH MONDAY...COME THURSDAY MORNING A
STALLED FRONT WILL BE DRAPED SOUTHWEST TO NORTHEAST ACROSS OUR CWA.
MODELS DIFFER ON HOW FAR SOUTHEAST THE STALLED FRONT WILL BE IN OUR
CWA BUT CONSENSUS PLACES IT SOUTHEAST OF THE NATCHEZ TRACE.
NORTHWEST OF THE STALLED FRONT PWATS WILL BE KNOCKED DOWN BELOW ONE
INCH WITH SURFACE DEW POINTS IN THE UPPER 50S TO LOWER 60S.
SOUTHEAST OF THE BOUNDARY A MOIST AIR MASS WILL REMAIN WITH DEW
POINTS AROUND 70 DEGREES AND PWATS AROUND AN INCH AN A HALF. PLENTY
OF CLOUD COVER AND ONGOING CONVECTION IS EXPECTED ALONG AND
SOUTHEAST OF THE BOUNDARY BUT AFTERNOON HIGHS WILL TOP OUT WELL
ABOVE NORMAL IN THE UPPER 70S. THESE TEMPERATURES WILL CONTRIBUTE TO
MLCAPE VALUES OF 1000-1300J/KG IN AN ENVIRONMENT WHERE THE 0-6KM
BULK SHEAR WILL STILL BE AROUND 45KTS AND 0-3KM STORM RELATIVE
HUMIDITIES AOA 200M2/2. A FEW STRONG TO SEVERE STORMS WILL BE
POSSIBLE DURING THE HEAT OF THE DAY OVER OUR SOUTHEAST WITH DAMAGING
WIND GUSTS BEING THE MAIN THREAT. THURSDAY NIGHT OUR WINDS ALOFT
BACK MORE TO THE SOUTH SOUTHWEST AHEAD OF A DEEPENING TROUGH OVER
THE WESTERN CONUS. SURFACE RIDGING FROM THE ATLANTIC WILL NOSE BACK
ACROSS THE GULF COAST STATES. THIS WILL HELP THE BOUNDARY MOVE BACK
NORTH AS A WARM FRONT THURSDAY NIGHT AND SERVE TO FOCUS FOR
CONVECTION FRIDAY. MODEL CONSENSUS HAS THE BOUNDARY JUST NORTHWEST
OF OUR CWA BY NOON FRIDAY RESULTING IN PWATS GREATER THAN AN INCH
AND A HALF OVER OUR WHOLE CWA. GREATEST POPS WL BE CARRIED OVER OUR
NORTHWEST ZONES FRIDAY BUT THERE WL BE A CHANCE FOR RAIN AREAWIDE.
THE DEEPENING TROUGH OVER THE WESTERN CONUS WILL CLOSE OFF OVER THE
DESERT SOUTHWEST BY SATURDAY MORNING AND SWING EAST TO THE TEXAS BIG
BEND REGION BY SUNDAY MORNING. THE MODELS BEGIN TO DIVERGE WITH THE
TRACK OF THE CLOSED LOW SUNDAY INTO TUESDAY WITH THE GFS BEING THE
MOST PROGRESSIVE AND FASTEST BRINGING THE ASSOCIATED COLD FRONT
ACROSS OUR CWA SUNDAY NIGHT. THE ECMWF IS THE SLOWEST WITH THE
CLOSED LOW AND BRINGS THE ASSOCIATED CLOD FRONT THROUGH OUR CWA
MONDAY NIGHT. BOTH MODELS AGREE THAT WARMER THAN NORMAL TEMPERATURES
WITH MOSTLY DIURNALLY DRIVEN RAIN CHANCES WILL CONTINUE OVER OUR CWA
THROUGH THE WEEKEND. HAVE USED A BLEND AND LEANED TOWARD A LITTLE
SLOWER FROPA IN LINE WITH CONSENSUS FROM MONDAY`S RUNS WITH MONDAY
BEING THE MAIN RAIN DAY. THERE STILL REMAIN INDICATION OF SOME
POTENTIAL FOR SEVERE STORMS ALONG AND AHEAD OF THE FRONT. /22/
AVIATION...MOST SITES ARE IFR/LIFR EARLY THIS MORNING AND EXPECT
THESE CONDITIONS TO CONTINUE THROUGH MOST OF THE PERIOD WITH A
CHANCE FOR SHOWERS AND THUNDERSTORM THIS AFTERNOON AND EVENING. THE
WINDS WILL REMAIN OUT OF THE SOUTH AT 6-9KTS ACROSS THE AREA./15/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 74 63 78 64 / 52 71 77 66
MERIDIAN 73 63 76 65 / 76 80 81 68
VICKSBURG 72 64 78 61 / 34 72 78 53
HATTIESBURG 74 64 78 66 / 89 87 82 66
NATCHEZ 74 65 79 65 / 49 79 73 55
GREENVILLE 68 62 77 58 / 18 71 80 49
GREENWOOD 72 64 78 60 / 26 62 80 64
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR MSZ018-019-
025>066-072>074.
LA...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR LAZ007>009-
015-016-023>026.
AR...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR ARZ074-075.
&&
$$
JAN/JAN
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1153 PM CST MON DEC 21 2015
.SHORT TERM: (Through Tuesday Afternoon)
Issued at 120 PM CST Mon Dec 21 2015
The cold front is making steady progress east across the area
with falling temperatures and a wind shift to the west-northwest.
Dry slot and breaks in the overcast allowed St. Louis to top out
at 67 degrees late this morning which tied the record for the
date that was set back in 1967. What a way to start astronomical
winter, which officially begins at 10:48 PM this evening!
Post frontal IFR stratus deck will blanket the CWA this evening and
despite the subsidence behind the storm system, the low level
moisture will be trapped under the inversion and keep the cloud deck
around tonight or allow for dense fog to develop if there is
clearing. HRRR has been very reliable in these post frontal cloud
forecasts as of late and it shows a LIFR cloud deck through at least
14Z on Tuesday.
Believe clouds or fog will try to scatter/dissipate from
southwest to northeast on Tuesday as flow becomes southerly. Have
forecast temperatures a bit cooler for Tuesday across the
northeastern half of the CWA due to this expected cloud cover.
CVKING
.LONG TERM: (Tuesday Night through Next Monday)
Issued at 120 PM CST Mon Dec 21 2015
Active weather pattern sets up Tuesday night through the
remainder of the forecast. Next shortwave and attendant surface
low/cold front is expected to approach the area from the west
Tuesday night and move across the CWA by late Wednesday evening.
Moisture advection is forecast to increase Tuesday night as the
low level jet increases and showers should be on the increase
after midnight. Can`t rule out a few rumbles of thunder as well,
given MUCAPES around 500 J/KG. This first round of "warm
advection precipitation" should move northeast by late morning on
Wednesday and depending on the amount of clearing and
destablization that can take place across the eastern half of the
CWA, severe thunderstorms may develop ahead and along the cold
front. As with almost any cold season event, the shear and
helicity values are extremely favorable for organized convection.
The question will be the surface based instabilty. The NAM is the
most bullish with around 500-750 J/KG. SPC has placed the eastern
portion of the CWA in a Marginal Risk for Day 3, and historical
analogs (St. Louis University CIPS) certainly support this. Have
introduced severe wording in the HWO and Situational Report to
account for this potential.
Needless to say temperatures will be well above average Tuesday
night and Wednesday. Some of the guidance actually has 70s on
Wednesday afternoon. I would think that is a tad too high, but we
got up to 67 degrees today so I suppose anything is possible this
winter!
The storms, if they develop, should exit rapidly to the east
Wednesday night leaving Christmas Eve and much of Christmas Day dry
and cooler (but yes, still above normal).
Attention then turns to a prolonged rain event Christmas night
through the Holiday Weekend with the prospect of flooding. The
synoptic setup is that the front that drifted to our south moves
back north and sits just to the south of us for a few days with a
classic setup for elevated convection as a deep trof and surface low
develop to our southwest. The front lifts north by early next week
with the system moving over the top of us. GFS has a maximum of
7-10 inches of rain from southwest Missouri through the St. Louis
Metro, the ECWMF has 4-6 inches, and the Central Region SuperBlend
of model data (which includes WPC) has widespread amounts of 5-7
inches. This amount of rain, even spread out over several days,
will cause local streams, creeks and rivers to flood. If
convection occurs and locally higher amounts are realized, then
flash flooding could be a possibility toward the end of the event
once the ground has been thoroughly saturated. Given these
concerns have decided to add mention of flooding in both the HWO
and Situation Report.
Temperatures will remain above normal and fluctuate depending on the
exact placement of the front during the extended portion of the
forecast.
CVKING
&&
.AVIATION: (For the 06z TAFs through 06z Tuesday Night)
Issued at 1139 PM CST Mon Dec 21 2015
IFR flight conditions over most of Missouri and west central
Illinois will overspread the remainder of the area through the
remainder of the night. Expect lowest ceilings/vsbys over central
MO where ceilings will likely be at or below 500 ft. If there is
any clearing, the setup for fog is excellent, so the stratus may
turn into a dense fog with vsbys at or below 1SM. Did not mention
the lower visibility in the KCOU TAF as I`m not sure there will be
any clearing at this time. Low flight conditions will persist
Tuesday morning...with lifting and scattering clouds from the
west during the late morning or early afternoon. Wind will turn to
the south-southeast ahead of the next storm system allowing clouds
to build back into the area during the evening. Looks like the
best chance for rain will hold off until after 06Z
Specifics for KSTL:
Ceiling just dropped below 900 ft right before I sent the
TAF...and I expect IFR ceilings to prevail at Lambert until at
least mid morning Tuesday. Guidance is forecasting the ceilings to
lift and scatter out Tuesday afternoon, but I think it`s too quick
given the moist low levels and weak December sunshine. Therefore I
opted to keep the ceilings below 2000 ft until mid afternoon. If
there is a period of VFR Tuesday afternoon, I think it will be
short-lived. South-southeast flow will develop and push abundant
low level clouds back into the region...along with showers and
possibly a few thunderstorms after 06Z.
Carney
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
532 PM CST WED DEC 23 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 314 PM CST WED DEC 23 2015
PRECIPITATION CHANCES HEADLINE THE SHORT TERM PERIOD. FOR THE
OVERNIGHT...A SHORTWAVE TROUGH CURRENTLY BISECTING WYOMING WILL
CONTINUE TO PUSH EAST THIS EVENING AND BRING ACCUMULATING SNOW FROM
WEST TO EAST ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. CROSS
SECTIONS REVEAL A POTENT MID-LEVEL FGEN BAND THAT WORKING ON STEEP
LOWER AND MID-LEVEL LAPSE RATES AND NEGATIVE EPV. ANTICIPATE THAT
THE BAND WILL BE FAIRLY TIGHT...SO WHERE IT SETS UP...A BRIEF PERIOD
OF MODERATE SNOW IS POSSIBLE. BASED OFF OF THICKNESS...THE NAM IS
GENERATING SNOW ACCUMULATIONS OF UP TO 5 INCHES ACROSS OUR SOUTH.
THE FORWARD SPEED OF THE SYSTEM AND THE FACT THAT MUCH OF THE QPF IS
INITIALLY WASTED AS SATURATION IS SEVERELY LIMITED IS THE MAIN
REASONS WHY WE ARE LIMITING SNOW ACCUMULATIONS AT TWO INCHES OR LESS
WITH THIS SYSTEM. HOWEVER WITH THE CONVECTIVE POTENTIAL...NOT ALL
LOCATIONS WILL SEE EVEN AN INCH...BUT LIKEWISE...UNDER THE
CONVECTIVE BAND...LOCALIZED HIGHER AMOUNTS ARE NOT OUT OF THE
QUESTION. ALSO OF NOTE...NAM BUFR SOUNDINGS REVEAL A PERIOD OF -FZDZ
OR FZFG BEFORE SATURATION IS REALIZED WHERE THE SNOW IS FORECAST.
THERE/S NO MENTION OF THE -FZDZ IN THE FORECAST AT THIS POINT AS
MOISTURE PROFILES ARE BRIEFLY MARGINALLY SUPPORTIVE FOR DZ AND NOT
ALL MODELS ARE SUGGESTING DRIZZLE. IF A BRIEF PERIOD OF FZDZ IS
REALIZED...NO ACCUMULATIONS ARE ANTICIPATED. THE SYSTEM IS
PROGRESSIVE WITH ALL QPF EAST OF THE CWA BY 18Z THURSDAY.
FORECAST TEMPERATURES ARE A BLEND OF NUMERICAL GUIDANCE WITH THE
PREVIOUS FORECAST...WHICH SEEMED REASONABLE WITH HIGHS IN THE 30S
ACROSS THE CWA ON THURSDAY AND LOWS TONIGHT MAINLY IN THE TEENS.
OVER THE SNOW PACK...A FEW SINGLE DIGITS ARE POSSIBLE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 314 PM CST WED DEC 23 2015
BY MIDDAY FRIDAY...THERE IS A WELL-DEVELOPED UPWARD TRAJECTORY IN
THE 285-300K LAYER FROM THE TEXAS GULF COAST TO THE NORTHERN
PLAINS. THE TRAJECTORY BRINGS MIXING RATIOS OF 2-4G/KG TO
NEBRASKA. TOWARD LATE FRIDAY EVENING... SATURATION DEFICITS OF
LESS THAN 25MB ARE INDICATED IN THE SANDHILLS...NORTH CENTRAL
NEBRASKA AND SOUTHWEST NEBRASKA. A CROSS-SECTION ALONG A CDR-LXN
LINE SHOWS SOME 2D- FRONTOGENESIS IN THE 295-305K LAYER OVER THE
SANDHILLS AND ISENTROPIC LIFT OVER A LARGE PART OF THE AREA WITH
ENHANCEMENT IN THE INDIRECT THERMAL CIRCULATION OVER THE SANDHILLS
AND NORTH CENTRAL NEBRASKA. THUS...THE HIGHEST PROBABILITY OF
SIGNIFICANT PRECIPITATION IS NORTH AND WEST OF A LINE FROM ONEILL
TO SIDNEY WHERE PRECIPITATION TOTALS EXCEEDING 0.50 INCH ARE
POSSIBLE. IN THAT AREA...SOUNDINGS SEEM TO FAVOR SNOW TO LIQUID
RATIOS OF 12:1 TO 15:1 OR GREATER. SNOWFALL TOTALS USING SNOW TO
LIQUID RATIOS RUN 5-7 INCHES WITH THE HEAVIEST ALONG U.S. HIGHWAY
20 AND THE WESTERN NIOBRARA VALLEY. CONSIDERING THAT THIS COULD
AFFECT HOLIDAY TRAVEL...THE POTENTIAL IMPACT WARRANTS A WATCH WITH
UPDATES TO ADVISORIES AND WARNINGS AS NEEDED. FOR OTHER
AREAS...CURRENT INDICATIONS ARE THAT 3-5 INCHES CAN BE EXPECTED IN
NORTH CENTRAL THROUGH SOUTHWEST NEBRASKA AND 1-3 INCHES IN SOUTH
CENTRAL AND EXTREME SOUTHWEST NEBRASKA. THE OTHER
THE NEXT SYSTEM...THEN...IS EXPECTED EARLY NEXT WEEK. FOR MONDAY
EVENING THROUGH TUESDAY...THERE ARE SIGNIFICANT DIFFERENCES BETWEEN
THE ECMWF AND THE GFS40 WITH THE ECMWF SHOWING A PRONOUNCED NEGATIVE
TILT AND A MORE WESTERLY STORM TRACK. EITHER WAY...THE SANDHILLS AND
NORTH CENTRAL NEBRASKA CAN EXPECT A GLANCING BLOW AT MOST WITH THE
GFS40 LEAVING THOSE AREAS WITHOUT PRECIPITATION.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 532 PM CST WED DEC 23 2015
THE AVIATION FORECAST IS A BIT PESSIMISTIC KEEPING MVFR CIGS AT
KLBF AND KVTN THROUGH 18Z THURSDAY. THE NAM KEEPS THE MVFR AND
THE RAP MODEL SHOWS THEM THROUGH 16Z...THE LAST AVAILABLE HOUR.
THE ECM SHOWS VFR UNTIL 18Z.
THROUGHOUT THE FCST AREA...MVFR WILL LIKELY DEVELOP FROM KIEN TO
KIML WHICH MOVES EAST THURSDAY.
A PERIOD OF IFR IN SNOW IS EXPECTED SOUTH OF INTERSTATE 80
TONIGHT...04Z-10Z.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR NEZ004>008-094.
&&
$$
SHORT TERM...JACOBS
LONG TERM...SPRINGER
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1144 AM CST TUE DEC 22 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM CST TUE DEC 22 2015
FORECAST CONCERNS WILL BE POTENTIAL FOR MIXED PRECIPITATION/RAIN/
SNOW THROUGH THE THURSDAY.
LARGE SCALE PATTERNS HAS AN H5 TROUGH ENCOMPASSING MUCH OF THE
U.S. THIS MORNING WITH SHORTWAVE TROUGH ENERGY EMBEDDED IN THE
FLOW OVER THE NORTHERN ROCKIES MOVING INTO THE WESTERN HIGH
PLAINS. LIGHTNING STRIKES WERE NOTED OVER PARTS OF NORTHERN UTAH
AND WYOMING. THIS SHORTWAVE TROUGH WILL ROTATE THROUGH...MAINLY
AFFECTING THE DAKOTAS. THIS WEATHER SYSTEM WILL SPREAD
ACCUMULATING SNOW ACROSS A LARGE PART OF NORTH DAKOTA...NORTH OF
THE TRACK OF THE SURFACE LOW. WATER VAPOR SATELLITE IMAGERY SHOWS
INCREASING HIGHER LEVEL MOISTURE ADVANCING EASTWARD FROM THE WEST
ASSOCIATED WITH A STRONG 160KT H3 JET MOVING INTO THE WEST COAST.
THE LOW LEVEL JET FROM CENTRAL NEBRASKA THROUGH CENTRAL KANSAS
WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA AND INCREASE
TO 50KTS. THIS WILL HELP BREAK UP THE LOW CLOUDS (AND FOG) MIXING
IN SOME OF THE DRY AIR ALOFT. SOUTH WINDS WILL INCREASE TO 15 TO
30 MPH. MID AND HIGH CLOUDS CAN BE EXPECTED THROUGHOUT THE DAY.
H85 TEMPERATURES INCREASE TO +6-+8 DEG C. WARMER HIGHS IN THE 40S
TO LOWER 50S ARE FORECAST.
TONIGHT...THE FRONTAL SYSTEM BECOMES COMPLEX...WITH SURFACE LOW
PRESSURE OVER COLORADO MOVING INTO KANSAS AND THE COLD FRONT
APPROACHES FROM THE WEST WITH THE NORTHERN SYSTEM. BY 06Z AN
INVERTED TROF SHOULD EXTEND NEAR LINCOLN TOWARD SIOUX CITY...WITH
MILD AIR ON THE EAST SIDE OF THE FRONT AND COOLER AIR TO THE WEST.
THERE ARE STILL SOME DIFFERENCES IN THE MODELS AS TO THE EFFECTS
OF THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM SYSTEM.
THERE MAY BE TWO BANDS OF MORE FOCUSED PRECIPITATION WITH LIGHTER
PRECIPITATION IN BETWEEN. BETWEEN 06Z-12Z...THE PRECIPITATION
SHOULD EXPAND IN THESE TWO AREAS. THE GFS DOES NOT REALLY SHOW A
MIX OF PRECIP...HOWEVER THE HRRR EXP/NAM DO HAVE MIXED OF
PRECIPITATION. DO MENTION A MIX ON THE WESTERN PARTS OF THE PRECIP
AREA WITH RAIN WHERE THIS IS SUPPORTED...CONTINUING INTO WEDNESDAY
MORNING...BEFORE MOVING OUT IN THE AFTERNOON. THE 06Z MODELS ARE
COMING IN A LITTLE SLOWER...SO THE TIMING MAY NEED TO BE ADJUSTED.
HIGHS WEDNESDAY SHOULD BE IN THE LOWER 30S TO MID 40S NEAR THE
KANSAS BORDER.
THIS ACTIVE PATTERN CONTINUES WITH A SHORTWAVE MOVING THROUGH LATE
WEDNESDAY NIGHT AND THURSDAY. PRELIMINARY TEMPERATURES APPEAR TO
SUPPORT A MAINLY LIGHT SNOW EVENT. THE NAM IS MORE INTENSE WITH
THIS SHORTWAVE...FARTHER NORTH AND LASTS INTO THE AFTERNOON. FOR
NOW HAVE SOME LIGHT SNOW AMOUNTS MENTIONED.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM CST TUE DEC 22 2015
THERE ARE STILL SIGNIFICANT DIFFERENCES IN THE EXTENDED. WE
CONTINUE TO MENTION RAIN/SNOW FOR FRIDAY AS A STRONGER TROUGH
MOVES INTO UTAH/WYOMING/COLORADO. THE STORM SYSTEM CLOSES OFF OVER
ARIZONA FRIDAY NIGHT WITH WEAK FORCING OVER THE AREA. A TROUGH IN
THE NORTHERN PLAINS REINFORCES THE COLD AIR A LITTLE FARTHER SOUTH
SATURDAY. THE LARGER DIFFERENCES ARE FOR SUNDAY AND MONDAY WITH
THE GFS TRACK OF THE CLOSED LOW MUCH FARTHER NORTH OVER KANSAS
CITY COMPARED TO THE EC...STILL OVER TEXAS.THE GFS HAS MORE
PRECIP WHILE THE EC IS MORE DRY FOR NEB/IA. UNTIL THERE IS BETTER
AGREEMENT...WE STILL HAVE PRECIP CHANCES MENTIONED IN THESE
PERIODS. TEMPERATURES REMAIN AT OR ABOVE NORMAL FOR THIS TIME OF
YEAR.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1137 AM CST TUE DEC 22 2015
VFR CONDITIONS WITH GUSTY SOUTHEAST 15 TO 25KT WILL PERSIST
THROUGH 00Z BEFORE WINDS DIMINISH TO LESS THAN 10KT. DETERIORATING
CONDITIONS ARE FORECAST AFTER 06Z WITH CIGS DROPPING TO MVFR AT
KOMA AND KLNK. RAIN WILL ALSO DEVELOP BY 10Z WHEN IFR TO LIFR
CONDITIONS ARE FORECAST BOTH VSBYS AND CIGS AT KOMA AND KLNK. THE
RAIN AND WORST AVIATION WEATHER LOOKS TO STAY SOUTHEAST OF KOFK
THROUGH THE EVENT...WITH MVFR CIGS FORECAST THERE. NORTH WINDS OF
15 TO 25KT ARE ALSO EXPECTED AT ALL EASTERN NEBRASKA TAF SITES BY
12Z OR SO.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
520 AM CST TUE DEC 22 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM CST TUE DEC 22 2015
FORECAST CONCERNS WILL BE POTENTIAL FOR MIXED PRECIPITATION/RAIN/
SNOW THROUGH THE THURSDAY.
LARGE SCALE PATTERNS HAS AN H5 TROUGH ENCOMPASSING MUCH OF THE
U.S. THIS MORNING WITH SHORTWAVE TROUGH ENERGY EMBEDDED IN THE
FLOW OVER THE NORTHERN ROCKIES MOVING INTO THE WESTERN HIGH
PLAINS. LIGHTNING STRIKES WERE NOTED OVER PARTS OF NORTHERN UTAH
AND WYOMING. THIS SHORTWAVE TROUGH WILL ROTATE THROUGH...MAINLY
AFFECTING THE DAKOTAS. THIS WEATHER SYSTEM WILL SPREAD
ACCUMULATING SNOW ACROSS A LARGE PART OF NORTH DAKOTA...NORTH OF
THE TRACK OF THE SURFACE LOW. WATER VAPOR SATELLITE IMAGERY SHOWS
INCREASING HIGHER LEVEL MOISTURE ADVANCING EASTWARD FROM THE WEST
ASSOCIATED WITH A STRONG 160KT H3 JET MOVING INTO THE WEST COAST.
THE LOW LEVEL JET FROM CENTRAL NEBRASKA THROUGH CENTRAL KANSAS
WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA AND INCREASE
TO 50KTS. THIS WILL HELP BREAK UP THE LOW CLOUDS (AND FOG) MIXING
IN SOME OF THE DRY AIR ALOFT. SOUTH WINDS WILL INCREASE TO 15 TO
30 MPH. MID AND HIGH CLOUDS CAN BE EXPECTED THROUGHOUT THE DAY.
H85 TEMPERATURES INCREASE TO +6-+8 DEG C. WARMER HIGHS IN THE 40S
TO LOWER 50S ARE FORECAST.
TONIGHT...THE FRONTAL SYSTEM BECOMES COMPLEX...WITH SURFACE LOW
PRESSURE OVER COLORADO MOVING INTO KANSAS AND THE COLD FRONT
APPROACHES FROM THE WEST WITH THE NORTHERN SYSTEM. BY 06Z AN
INVERTED TROF SHOULD EXTEND NEAR LINCOLN TOWARD SIOUX CITY...WITH
MILD AIR ON THE EAST SIDE OF THE FRONT AND COOLER AIR TO THE WEST.
THERE ARE STILL SOME DIFFERENCES IN THE MODELS AS TO THE EFFECTS
OF THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM SYSTEM.
THERE MAY BE TWO BANDS OF MORE FOCUSED PRECIPITATION WITH LIGHTER
PRECIPITATION IN BETWEEN. BETWEEN 06Z-12Z...THE PRECIPITATION
SHOULD EXPAND IN THESE TWO AREAS. THE GFS DOES NOT REALLY SHOW A
MIX OF PRECIP...HOWEVER THE HRRR EXP/NAM DO HAVE MIXED OF
PRECIPITATION. DO MENTION A MIX ON THE WESTERN PARTS OF THE PRECIP
AREA WITH RAIN WHERE THIS IS SUPPORTED...CONTINUING INTO WEDNESDAY
MORNING...BEFORE MOVING OUT IN THE AFTERNOON. THE 06Z MODELS ARE
COMING IN A LITTLE SLOWER...SO THE TIMING MAY NEED TO BE ADJUSTED.
HIGHS WEDNESDAY SHOULD BE IN THE LOWER 30S TO MID 40S NEAR THE
KANSAS BORDER.
THIS ACTIVE PATTERN CONTINUES WITH A SHORTWAVE MOVING THROUGH LATE
WEDNESDAY NIGHT AND THURSDAY. PRELIMINARY TEMPERATURES APPEAR TO
SUPPORT A MAINLY LIGHT SNOW EVENT. THE NAM IS MORE INTENSE WITH
THIS SHORTWAVE...FARTHER NORTH AND LASTS INTO THE AFTERNOON. FOR
NOW HAVE SOME LIGHT SNOW AMOUNTS MENTIONED.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM CST TUE DEC 22 2015
THERE ARE STILL SIGNIFICANT DIFFERENCES IN THE EXTENDED. WE
CONTINUE TO MENTION RAIN/SNOW FOR FRIDAY AS A STRONGER TROUGH
MOVES INTO UTAH/WYOMING/COLORADO. THE STORM SYSTEM CLOSES OFF OVER
ARIZONA FRIDAY NIGHT WITH WEAK FORCING OVER THE AREA. A TROUGH IN
THE NORTHERN PLAINS REINFORCES THE COLD AIR A LITTLE FARTHER SOUTH
SATURDAY. THE LARGER DIFFERENCES ARE FOR SUNDAY AND MONDAY WITH
THE GFS TRACK OF THE CLOSED LOW MUCH FARTHER NORTH OVER KANSAS
CITY COMPARED TO THE EC...STILL OVER TEXAS.THE GFS HAS MORE
PRECIP WHILE THE EC IS MORE DRY FOR NEB/IA. UNTIL THERE IS BETTER
AGREEMENT...WE STILL HAVE PRECIP CHANCES MENTIONED IN THESE
PERIODS. TEMPERATURES REMAIN AT OR ABOVE NORMAL FOR THIS TIME OF
YEAR.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 520 AM CST TUE DEC 22 2015
LOW CLOUDS AND FOG CURRENTLY IN PLACE AT KOFK AND KOMA WILL LIFT
AS SOUTHERLY LOW LEVEL FLOW INCREASES THE NEXT SEVERAL HOURS.
AFTER THE LOW CLOUDS MOVE OUT...LOOK FOR VFR CONDITIONS THE REST
OF THE DAY. MOISTURE WILL BE ON THE INCREASE AGAIN TONIGHT AS LIFT
INCREASES WITH APPROACH OF NEXT SHORTWAVE TROUGH. CEILINGS WILL
LOWER WITH MVFR CONDITIONS POSSIBLE AFTER MIDNIGHT. WE SHOULD ALSO
SEE AN INCREASE IN PCPN CHANCES AFTER 06Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
427 AM CST TUE DEC 22 2015
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 345 AM CST TUE DEC 22 2015
FORECAST CONCERNS WILL BE POTENTIAL FOR MIXED
PRECIPITATION/RAIN/SNOW THROUGH THE THURSDAY.
LARGE SCALE PATTERNS HAS AN H5 TROUGH ENCOMPASSING MUCH OF THE
U.S. THIS MORNING WITH SHORTWAVE TROUGH ENERGY EMBEDDED IN THE
FLOW OVER THE NORTHERN ROCKIES MOVING INTO THE WESTERN HIGH
PLAINS. LIGHTNING STRIKES WERE NOTED OVER PARTS OF NORTHERN UTAH
AND WYOMING. THIS SHORTWAVE TROUGH WILL ROTATE THROUGH...MAINLY
AFFECTING THE DAKOTAS. THIS WEATHER SYSTEM WILL SPREAD
ACCUMULATING SNOW ACROSS A LARGE PART OF NORTH DAKOTA...NORTH OF
THE TRACK OF THE SURFACE LOW. WATER VAPOR SATELLITE IMAGERY SHOWS
INCREASING HIGHER LEVEL MOISTURE ADVANCING EASTWARD FROM THE WEST
ASSOCIATED WITH A STRONG 160KT H3 JET MOVING INTO THE WEST COAST.
THE LOW LEVEL JET FROM CENTRAL NEBRASKA THROUGH CENTRAL KANSAS
WILL CONTINUE TO MOVE EAST ACROSS THE FORECAST AREA AND INCREASE
TO 50KTS. THIS WILL HELP BREAK UP THE LOW CLOUDS (AND FOG) MIXING
IN SOME OF THE DRY AIR ALOFT. SOUTH WINDS WILL INCREASE TO 15 TO
30 MPH. MID AND HIGH CLOUDS CAN BE EXPECTED THROUGHOUT THE DAY.
H85 TEMPERATURES INCREASE TO +6-+8 DEG C. WARMER HIGHS IN THE 40S
TO LOWER 50S ARE FORECAST.
TONIGHT...THE FRONTAL SYSTEM BECOMES COMPLEX...WITH SURFACE LOW
PRESSURE OVER COLORADO MOVING INTO KANSAS AND THE COLD FRONT
APPROACHES FROM THE WEST WITH THE NORTHERN SYSTEM. BY 06Z AN
INVERTED TROF SHOULD EXTEND NEAR LINCOLN TOWARD SIOUX CITY...WITH
MILD AIR ON THE EAST SIDE OF THE FRONT AND COOLER AIR TO THE WEST.
THERE ARE STILL SOME DIFFERENCES IN THE MODELS AS TO THE EFFECTS
OF THE NORTHERN STREAM SYSTEM AND THE SOUTHERN STREAM SYSTEM.
THERE MAY BE TWO BANDS OF MORE FOCUSED PRECIPITATION WITH LIGHTER
PRECIPITATION IN BETWEEN. BETWEEN 06Z-12Z...THE PRECIPITATION
SHOULD EXPAND IN THESE TWO AREAS. THE GFS DOES NOT REALLY SHOW A
MIX OF PRECIP...HOWEVER THE HRRR EXP/NAM DO HAVE MIXED OF
PRECIPITATION. DO MENTION A MIX ON THE WESTERN PARTS OF THE PRECIP
AREA WITH RAIN WHERE THIS IS SUPPORTED...CONTINUING INTO WEDNESDAY
MORNING...BEFORE MOVING OUT IN THE AFTERNOON. THE 06Z MODELS ARE
COMING IN A LITTLE SLOWER...SO THE TIMING MAY NEED TO BE ADJUSTED.
HIGHS WEDNESDAY SHOULD BE IN THE LOWER 30S TO MID 40S NEAR THE
KANSAS BORDER.
THIS ACTIVE PATTERN CONTINUES WITH A SHORTWAVE MOVING THROUGH LATE
WEDNESDAY NIGHT AND THURSDAY. PRELIMINARY TEMPERATURES APPEAR TO
SUPPORT A MAINLY LIGHT SNOW EVENT. THE NAM IS MORE INTENSE WITH
THIS SHORTWAVE...FARTHER NORTH AND LASTS INTO THE AFTERNOON. FOR
NOW HAVE SOME LIGHT SNOW AMOUNTS MENTIONED.
.LONG TERM...(THURSDAY NIGHT THROUGH MONDAY)
ISSUED AT 345 AM CST TUE DEC 22 2015
THERE ARE STILL SIGNIFICANT DIFFERENCES IN THE EXTENDED. WE
CONTINUE TO MENTION RAIN/SNOW FOR FRIDAY AS A STRONGER TROUGH
MOVES INTO UTAH/WYOMING/COLORADO. THE STORM SYSTEM CLOSES OFF OVER
ARIZONA FRIDAY NIGHT WITH WEAK FORCING OVER THE AREA. A TROUGH IN
THE NORTHERN PLAINS REINFORCES THE COLD AIR A LITTLE FARTHER SOUTH
SATURDAY. THE LARGER DIFFERENCES ARE FOR SUNDAY AND MONDAY WITH
THE GFS TRACK OF THE CLOSED LOW MUCH FARTHER NORTH OVER KANSAS
CITY COMPARED TO THE EC...STILL OVER TEXAS.THE GFS HAS MORE
PRECIP WHILE THE EC IS MORE DRY FOR NEB/IA. UNTIL THERE IS BETTER
AGREEMENT...WE STILL HAVE PRECIP CHANCES MENTIONED IN THESE
PERIODS. TEMPERATURES REMAIN AT OR ABOVE NORMAL FOR THIS TIME OF
YEAR.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1130 PM CST MON DEC 21 2015
IFR OR LIFR CONDITIONS WILL PREVAIL AT BOTH KOFK AND KOMA THROUGH
15Z AND ARE EXPECTED TO DEVELOP AT KLNK BY 09Z. MVFR CONDITIONS
THEN DEVELOP AT ALL THREE SITES AFTER 15Z AND VFR CONDITIONS AFTER
21Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
IA...NONE.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...FOBERT
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1001 PM EST WED DEC 23 2015
.SYNOPSIS...
UNSEASONABLY WARM, AND SHOWERY WEATHER, WILL PERSIST INTO
THURSDAY. IN FACT, RECORD HIGH TEMPERATURES IN THE MID AND UPPER
60S ARE EXPECTED CHRISTMAS EVE DAY. CHRISTMAS DAY LOOKS DRY, AND
STILL FAIRLY MILD, WITH HIGHS MOSTLY IN THE FIFTIES. RAIN IS
LIKELY BY LATER SATURDAY, AS A WARM FRONT APPROACHES FROM THE
SOUTH.
&&
.NEAR TERM /THROUGH THURSDAY/...
945 PM UPDATE...
SPED UP TIMING OF FIRST BATCH OF RAIN EVEN FASTER. LOWERED POPS IN
THE WEST TO NOTHING. WILL BE WAITING FOR THE CONVECTION IN OHIO.
MODEL DIFFERENCES ON TIMING AND COVERAGE. FOLLOWING THE HRRR SOME
AND BRINGING IN SHOWERS INTO STEUBEN AROUND 9Z. CONFIDENCE NOT
HIGH ENOUGH TO INCLUDE THUNDER BUT MODELS HINTING AT SOME
REMAINING. TEMPERATURES ARE SLOWLY RISING.
7 PM UPDATE...
RAIN ALREADY PULLING OUT OF WRN ZONES AND DROPPED POPS AND QPF.
REST OF RAIN WILL PULL OUT THIS EVENING. AFTER THAT WILL JUST GET
REMNANTS FROM THE CONVECTION NOW IN THE OHIO VALLEY LATE TONIGHT.
TEMPS ARE TRICKY WITH MAX AND MIN TEMPS ALMOST THE SAME AS
TEMPERATURES RISE TONIGHT. SOME CURRENT TEMPS ABOVE THE AFTN MAX
TEMP GRID. ADJUSTED MAX MIN AND HOURLY TEMPS. CLOUDY SKIES WILL
CONTINUE OVERNIGHT WITH THE DEEP MOIST SOUTHERLY FLOW.
230 PM UPDATE...
SHOWERS ARE OVERSPREADING THE REGION THIS AFTERNOON, RIGHT ON
SCHEDULE, AND THEY SHOULD CONTINUE THROUGH EARLY EVENING. MOST OF
THE FORCED LIFT, WITH THE ASSOCIATED SHORT-WAVE, SHOULD BE EAST
OF OUR FORECAST AREA BY MIDNIGHT. THUS, WE STILL ANTICIPATE A
LULL IN PRECIPITATION OVERNIGHT.
MOST OF OUR HIGH-RESOLUTION MODEL GUIDANCE BRINGS A WEAKENING
LINE OF SHOWERS INTO WESTERN NY/PA DURING THE PRE-DAWN HOURS. THIS
IS LIKELY THE REMNANTS OF THE CONVECTIVE LINE IMPACTING SRN
IL/IN/WRN KY THIS AFTERNOON. AS JUST STATED, THIS LINE OF SHOWERS
SHOULD BE IN A WEAKENING STATE AS IT PROGRESSES EASTWARD, AND AS
SUCH, ITS SURVIVAL INTO OUR FORECAST AREA CLOSE TO DAYBREAK IS
UNCERTAIN. FOR NOW, WE`RE CALLING FOR SCATTERED SHOWERS AFTER 4-5
AM, TO COVER THIS POSSIBILITY.
AS A LOW-LEVEL JET MOVES OVERHEAD LATE TONIGHT INTO EARLY
THURSDAY, CONDITIONS SHOULD BECOME WELL MIXED, THUS MAKING
WIDESPREAD FOG DEVELOPMENT UNLIKELY. PART OF THIS STRENGTHENING
FLOW REGIME WILL ALSO BE VERY PRONOUNCED LOW-LEVEL WARM ADVECTION.
THUS, WE`VE CONTINUED TO INDICATE RISING TEMPERATURES OVERNIGHT,
AND MANY AREAS SHOULD ALREADY BE INTO THE 60S BY 5-8 AM.
A STRENGTHENING CYCLONE WILL CONTINUE TO TRACK THROUGH THE WESTERN
LAKES REGION, AND THEN INTO ONTARIO FOR CHRISTMAS EVE. AS IT DOES
SO, IT WILL SWING A COLD FRONT ACROSS CENTRAL NY/NORTHEAST PA
DURING THE LATE MORNING/EARLY AFTERNOON PERIOD. THE BEST UPPER-
LEVEL DYNAMICS WILL BE UP OVER CANADA, AND WELL REMOVED FROM OUR
REGION. THUS, WE FEEL THAT SHOWER ACTIVITY, ALONG AND AHEAD OF
THE FRONT, WILL BE SCATTERED IN NATURE FOR MOST OF THE FORECAST
AREA. GIVEN THE ANOMALOUS WARMTH, NAM/SREF GUIDANCE IN PARTICULAR
SHOWS WEAK INSTABILITY ON THURSDAY (200-400 J/KG OF ML CAPE). AS A
RESULT, WE HAVE AN ISOLATED MENTION OF THUNDER. SHOWERS SHOULD
HAVE A TENDENCY TO DIMINISH FROM WEST TO EAST DURING THE
AFTERNOON, AS THE FRONT SWEEPS THROUGH THE REGION.
AS MENTIONED EARLIER, RECORD HIGHS SHOULD EASILY BE ATTAINED
THURSDAY (CURRENT RECORDS ARE 51 AT BINGHAMTON, 58 AT SYRACUSE,
AND 62 AT SCRANTON). IN FACT, SOME OF OUR NORMALLY WARMER VALLEY
LOCALES, ESPECIALLY OVER NORTHEAST PA, COULD EVEN MAKE A RUN AT 70
DEGREES!
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
3 PM UPDATE...
LATE CHRISTMAS EVE-CHRISTMAS DAY LOOKS MAINLY DRY, AS THE
AFOREMENTIONED FRONTAL ZONE SINKS SOUTHWARD INTO THE MID-ATLANTIC
REGION. THE AIR MASS BEHIND THE FRONT IS NOT VERY COLD AT ALL, AND
THIS IN COMBINATION WITH SOME SUNSHINE ON FRIDAY, SHOULD STILL
BRING HIGHS INTO THE 50S-LOWER 60S.
SATURDAY, THIS SAME FRONTAL BOUNDARY WILL BEGIN TO HEAD BACK
NORTHWARD AGAIN AS A WARM FRONT, IN RESPONSE TO ANOTHER DEVELOPING
CYCLONE OVER THE SOUTH-CENTRAL STATES. BY LATE SATURDAY, MODEL
GUIDANCE IS IN GOOD AGREEMENT DEPICTING A VERY STRONG UPPER JET
STREAK TO OUR NORTH, WITH THE RESPONSE BEING AN INCREASED LOW-
LEVEL JET/TIGHTENED THERMAL GRADIENT OVER NY/PA, JUST NORTH OF THE
APPROACHING WARM FRONT. ANY EARLY SUNSHINE SHOULD FADE BEHIND
INCREASING CLOUDS. THE LIKELIHOOD OF RAIN SHOULD THEN OVERSPREAD
THE FORECAST AREA, FROM SOUTH TO NORTH, BY LATE SATURDAY/SATURDAY
EVENING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
310 PM UPDATE...
THE LARGE-SCALE PATTERN SHOULD FEATURE AN ENERGETIC SOUTHWESTERLY
FLOW ALOFT EARLY IN THE PERIOD (THROUGH WEDNESDAY), WITH A
DEVELOPING BROAD TROUGH, AND MORE SEASONABLE TEMPERATURES LATER
NEXT WEEK.
AS FOR THE DAILY SENSIBLE WEATHER, MILD SHOWERY WEATHER SUNDAY,
WILL BE FOLLOWED BY A GRADUAL COOL-DOWN EARLY NEXT WEEK. THE
BIGGEST UNCERTAINTY LIES WITH THE EVOLUTION/EJECTION OF A POTENT
SOUTHERN-STREAM WAVE LATE MONDAY-TUESDAY (MODELS DIFFER
SIGNIFICANTLY ON TIMING/SURFACE LOW TRACK). IF PRECIPITATION
DEVELOPS QUICKLY ENOUGH, MIXED PHASE (SNOW/SLEET/FREEZING RAIN
MIX) WOULD BE POSSIBLE MONDAY NIGHT OR TUESDAY. IF THE MOISTURE
DOESN`T MOVE IN UNTIL MID-WEEK, TEMPERATURES SHOULD BE WARM ENOUGH
FOR RAIN BY THEN. TIME WILL TELL ON THIS ONE, WITH BETTER MODEL
AGREEMENT HOPEFULLY SEEN IN LATER RUNS.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
AN AREA OF SHOWERS IMPACTING ALL TERMINALS OUTSIDE OF KELM AND
KITH WILL MOVE EAST THROUGH 05Z. WIDESPREAD MVFR CIGS, WITH IFR AT
KBGM, WILL CONTINUE THROUGH 06Z. SLOWLY AS OUR WIND FLOW SHIFTS
INTO THE SOUTHWEST IMPROVEMENT IS EXPECTED AT ALL TERMINALS. THIS
WILL HAPPEN THE FASTEST AND IS MOST LIKELY AT KELM AND KSYR, BUT
MAY BE SLOWER AT THE REST OF THE TERMINALS. IN GENERAL THOUGH WE
SHOULD IMPROVE TO VFR TOWARD DAYBREAK.
IT WILL BE BREEZY THURSDAY, WITH GUSTS OVER 20 KTS POSSIBLE. A
THIN LINE OF SHOWERS WILL MOVE THROUGH THE TERMINALS THROUGH MID
MORNING. WHILE GENERALLY VFR THURSDAY, DURING THESE SHOWERS SOME
BRIEF RESTRICTIONS ARE POSSIBLE (MVFR OR IFR IN HEAVY RAIN) ALONG
WITH SOME GUSTS OVER 30 KTS POSSIBLE.
WINDS TONIGHT SOUTHEAST 5 TO 10 KTS, BECOMING SOUTHWEST TOWARD
DAYBREAK, AND BECOMING GUSTY ON THE HILLTOPS. SOUTHWEST WINDS
THURSDAY SUSTAINED AROUND 10, BUT GUSTS TO 20+KTS POSSIBLE.
.OUTLOOK...
FRI...VFR.
SAT/SUN/MON...RESTRICTIONS POSSIBLE IN RAIN.
&&
.CLIMATE...
RECORD WARM TEMPERATURES NEXT 3 DAYS POSSIBLE...ESPECIALLY
DECEMBER 24TH.
WARMEST LOW TEMPERATURES TODAY AND MAYBE THE 25TH. RECORD WARM
HIGH, LOW, AND AVERAGE THE 24TH LIKELY FOR ALL 3 SITES. FORECAST
HIGHS IN THE MID AND UPPER 60S AND LOWS AT MIDNIGHT UPPER 40S TO
LOWER 50S. WILL BE CLOSE TO THE ALL TIME RECORD DECEMBER
TEMPERATURES. BINGHAMTON CLOSEST WITH 65 12/01/2006 AND 12/29/1984
AND 12/06/1982. SYRACUSE 72 12/06/2001. SCRANTON 71 12/01/2006.
TODAY WITH TEMPERATURES STEADY TO RISING THE REST OF TODAY RECORD
MAX MINS. BINGHAMTON 43 TODAY BREAKS THE RECORD OF 40 IN 2006.
SCRANTON 47 TODAY BREAKS THE RECORD OF 45 IN 1931.
SYRACUSE 42 TODAY TIES THE RECORD OF 42 IN 1931.
FOR THE 24TH MAX MIN AVE
BGM 55 2014 42 1965 48 2014
SYR 58 1965 48 1931 52 1931
AVP 62 1933 47 1931 53 1931
THE 25TH MAX MINIMUM TEMPERATURE AT SCRANTON WHERE THE WARM AIR
LINGERS. AGAIN PROBABLY A LOW AT MIDNIGHT THE END OF THE 25TH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ/TAC
NEAR TERM...MLJ/TAC
SHORT TERM...MLJ
LONG TERM...MLJ
AVIATION...HEDEN
CLIMATE...
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1134 PM EST MON DEC 21 2015
.SYNOPSIS...
A BROAD SOUTHWEST FLOW ACROSS THE EASTERN HALF OF THE COUNTRY WILL
GENERALLY SUPPORT UNSETTLED WEATHER INTO CHRISTMAS EVE. PERIODIC
RAIN SHOWERS WILL BE ACCOMPANIED BY SIGNIFICANT DAY TO DAY WARMING
WITH NEAR RECORD TEMPERATURES IN THE 60S FORECAST FOR WEDNESDAY AND
THURSDAY. THESE EL NINO DRIVEN TEMPERATURES WILL BE ABOUT 30 DEGREES
ABOVE NORMAL...OR CLOSE TO LEVELS EXPERIENCED DURING THE FIRST HALF
OF OCTOBER.
&&
.NEAR TERM /THROUGH TUESDAY/...
THE REGION WILL BE IN A SOUTHWESTERLY FLOW THROUGH TUESDAY...WITH
LONGWAVE TROUGHING FROM THE PACIFIC COAST TO THE PLAINS. THE FIRST
OF TWO SHORTWAVES HAS EXITED INTO NORTHERN NEW ENGLAND LATE THIS
EVENING.
AT 1100 PM RADAR SHOWS SCATTERED SHOWERS LIFTING ACROSS LAKE
ONTARIO AND THE EASTERN LAKE ONTARIO REGION...WITH THESE HIT OR
MISS SHOWERS EXPECTED TO CONTINUE TO LIFT NORTH LATE THIS EVENING.
AFTER THIS THERE MAY BE A SPOTTY SHOWER OR DRIZZLE...BUT FOR THE
MOST PART IT SHOULD BE DRY. ANOTHER...MORE POTENT WAVE...WILL LIFT
FROM THE TENNESSEE VALLEY INTO OUR REGION LATE TONIGHT AND ACROSS
OUR REGION ON TUESDAY. THE 00/18Z GUIDANCE HAS TRENDED HIGHER WITH
QPF...AND BOTH RADAR TRENDS AND THE HRRR SUPPORT THIS. BUFKIT
SHOWS THE BEST LIFT WILL BE ALOFT...LIKELY WITH THE SHORTWAVE AND
AIDED BY A FAVORABLE JET QUADRANT. AS A RESULT...EXPECT A RATHER
STEADY AREA OF RAIN TO ENTER SOUTHERN PORTIONS LATE TONIGHT AND TO MOVE
ACROSS WESTERN NEW YORK TUESDAY MORNING BEFORE CROSSING THE
EASTERN LAKE ONTARIO REGION LATE TUESDAY MORNING AND EARLY
AFTERNOON. THIS MAY BRING A HALF INCH OF RAIN TO A CORRIDOR
EXTENDING FROM WELLSVILLE TO SYRACUSE WITH A QUARTER INCH MORE
COMMONPLACE ELSEWHERE. POPS REFLECT THE SAME TRENDS AS BEFORE BUT
ARE A BIT MORE DEFINITIVE.
TEMPERATURES WILL REMAIN STEADY OR SLOWLY RISE OVERNIGHT. CLOUDY
SKIES WILL LIMIT ANY RADIATIONAL COOLING...AND 850MB TEMPERATURES
WILL GRADUALLY WARM THROUGH THE PERIOD. EVEN WITH RAIN AND MOSTLY
CLOUDY SKIES TEMPERATURES ON TUESDAY WILL CLIMB DUE TO WARM AIR
ADVECTION AND RISE INTO THE 50S IN MOST LOCATIONS.
EXPECT FOG TO DEVELOP IN SOME AREAS TONIGHT...ESPECIALLY
IN AREAS WHERE THERE IS SNOW ON THE GROUND. THIS IS DUE TO DEW
POINTS RISING TO WELL ABOVE 32 AND DIMINISHING WINDS.
SPEAKING OF WINDS...WINDS ALOFT WILL DIMINISH THIS EVENING WHICH
WILL RESULT IN LESS GUSTY WINDS THROUGH TUESDAY MORNING. WINDS
ALOFT ARE NOT VERY STRONG...BUT THE TRACK OF THE SURFACE LOW IS
FAVORABLE TO MIX 925MB WINDS TO THE SURFACE WITH THE PASSAGE OF
THE LOW WITH SOME GUSTS TO 35 MPH ACROSS THE NIAGARA FRONTIER
TUESDAY AFTERNOON.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY NIGHT/...
EVENING UPDATE... LATEST MODELS SHOW WARM FRONT LIFTING NORTH ACROSS
THE FORECAST AREA ON WEDNESDAY AFTERNOON WITH OUR REGION RESIDING
WITHIN THE WARM SECTOR WEDNESDAY NIGHT BEFORE A COLD FRONT SWEEPS
ACROSS THURSDAY. THIS WILL HAVE AN IMPACT ON OUR TEMPS WITH THE
POTENTIAL FOR THE WARMEST TO BE LATER WEDNESDAY INTO WEDNESDAY NIGHT
BEFORE COOLING ON THURSDAY. EVEN WITH THIS SCENARIO WE STILL HAVE
THE POTENTIAL TO BREAK RECORD HIGHS BOTH WEDNESDAY AND THURSDAY WITH
HIGHEST TEMPS OCCURRING OVERNIGHT BRIDGING BOTH DAYS. HAVE ADJUSTED
THE HOURLY TEMP FORECAST TO REFLECT A NON-DIURNAL CURVE WEDNESDAY
NIGHT WHILE BUMPING HIGHS ON WEDNESDAY AND LOWERING A TOUCH ON
THURSDAY BASED ON QUICKER FRONTAL TIMING. THE REST OF THE FORECAST
REMAINS IN TACT.
PREVIOUS DISCUSSION... A HIGHLY AMPLIFIED PATTERN WILL CONTINUE TO
CHARACTERIZE THE MIDDLE OF THE WEEK WITH A FULL-LATITUDE TROUGH
CENTERED ON THE GREAT PLAINS. A POWERFUL UPPER LEVEL JET DIVING
ACROSS THE WESTERN U.S. WILL SERVE TO FURTHER AMPLIFY THIS
FEATURE...ENHANCING MERIDIONAL FLOW ACROSS THE EASTERN U.S. WHILE
DIRECTING A SERIES OF DISTURBANCES NORTHWARDS TOWARDS THE GREAT
LAKES. ALL OF THIS WILL TRANSLATE INTO A PERIOD OF UNSETTLED WEATHER
AND RECORD WARMTH ACROSS WESTERN AND NORTH-CENTRAL NEW YORK AS WE
APPROACH THE CHRISTMAS HOLIDAY. WE WILL DELVE FURTHER INTO THE
DETAILS BELOW...
THE PERIOD WILL OPEN ON A QUIET NOTE TUESDAY NIGHT AS THE AREA WILL
BE UNDER THE INFLUENCE OF SHORTWAVE RIDGING ALOFT...KEEPING
CONDITIONS DRY. WINDS WILL BACK TO THE SOUTH OVERNIGHT AS THE REGION
COMES UNDER THE INFLUENCE OF THE INCREASING MERIDIONAL FLOW DESCRIBED
ABOVE. THIS WILL PUMP INCREASINGLY WARM AND MOIST AIR ACROSS THE
LOWER GREAT LAKES WITH LOWS IN THE MID 40S TUESDAY NIGHT.
TEMPERATURES ON WEDNESDAY WILL REACH INTO THE UPPER 50S AND TOUCH 60
DEGREES ALONG LAKE ERIE...WHERE SOUTHEASTERLY DOWNSLOPING WILL AID
IN BOOSTING TEMPS. THIS WILL BE CLOSE ENOUGH TO AT LEAST TIE RECORD
HIGHS IN MANY LOCALES.
IN ADDITION TO THE POTENTIAL RECORD WARMTH WEDNESDAY...WE WILL SEE A
DECENT CHANCE FOR SHOWERS ACROSS MUCH OF THE FORECAST AREA BY
WEDNESDAY AFTERNOON AS A SHORTWAVE EJECTING OUT OF THE SOUTHERN
APPALACHIANS CROSSES CENTRAL NEW YORK. WHILE THERE MAY BE A
RESPITE BETWEEN SHOWERS ASSOCIATED WITH THIS INITIAL SHORTWAVE
WEDNESDAY AND SHOWERS ASSOCIATED WITH A FRONTAL SYSTEM ON
THURSDAY...GIVEN SOME UNCERTAINTY IN TIMING AND PLACEMENT OF
DETAILS AND CONTINUED ADVECTION OF WARM AND MOIST AIR ACROSS THE
THE REGION THROUGH THE PERIOD...WILL LEAVE IN A CHANCE OF SHOWERS
FOR WEDNESDAY NIGHT. TEMPS WEDNESDAY NIGHT WILL NOT FALL MUCH IF AT
ALL WITH A STIFF SOUTHERLY FLOW.
IF WEDNESDAY FEATURES NEAR-RECORD WARMTH...THURSDAY MAY BREAK
RECORDS ACROSS MUCH OF THE REGION AS 850MB TEMPS SURGE TO AN
ASTOUNDING +12C TO +14C AS GULF OF MEXICO AIR IS DRAWN NORTHWARDS
AHEAD OF A LOW PRESSURE SYSTEM LIFTING FROM THE WESTERN GREAT LAKES
TO JAMES BAY...A SCENARIO WE HAVE SEEN MULTIPLE TIMES THIS WINTER
ALREADY. A STRONG WIND FIELD ALOFT WITH A 850MB JET EXCEEDING 55KTS
WILL CREATE THE POTENTIAL FOR STRONG SOUTHERLY WINDS WEDNESDAY NIGHT
INTO THURSDAY. THE COMBINATION OF EXTREME WARM ADVECTION AND
SOUTHERLY DOWNSLOPING COULD EASILY PUSH TEMPERATURES IN THE 60S
ACROSS THE FORECAST AREA UNLESS THE COLD FRONT ARRIVES EARLY
THURSDAY. IT IS ALSO WORTH NOTING THAT RECORD HIGH LOWS WILL LIKELY
BE SET THURSDAY MORNING OWING TO ABOVE FACTORS WITH TEMPERATURES
REMAINING STEADY WITH LOWS ONLY IN THE MID 50S.
IN ADDITION TO THE WARM AND WINDY CONDITIONS...IT WILL LIKELY
BE WET AS WELL AS THE LOW PASSES TO OUR NORTHWEST AND SHOVES A
WEAKENING COOL FRONT ACROSS THE AREA. IT IS WORTH NOTING THAT THE
BETTER UPPER LEVEL SUPPORT AND THUS HEAVIER RAINFALL WILL LIKELY BE
FOUND OVER CANADA. SHOWERS WILL GRADUALLY TAPER OFF THURSDAY NIGHT
BEHIND THE COOL FRONT WHILE TEMPERATURES FALL BACK INTO THE LOWER
40S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
EVEN WITH THE PASSAGE OF A COOL FRONT THURSDAY... WE WILL CONTINUE
TO SEE MILD TEMPERATURES PERSIST THROUGH THE WEEKEND. FLOW ACROSS
THE LOWER GREAT LAKES WILL FLATTEN OUT AND BECOME MORE ZONAL ALOFT
WITH A BAROCLINIC ZONE LAYING ROUGHLY ACROSS THE GREAT LAKES. WITH
THE UPPER LEVEL JET REMAINING TO OUR NORTH...KEEPING ANY COLD AIR
LOCKED UP OVER CANADA...THE REGION WILL REMAIN UNDER THE INFLUENCE
OF MILD AIR FROM OUR SOUTH. HIGH PRESSURE WILL RESULT IN A DRY
CHRISTMAS DAY...THOUGH LINGERING UPPER LEVEL MOISTURE WILL LIKELY
YIELD FILTERED SUNSHINE AT BEST.
THE NEXT SHOT AT PRECIPITATION WILL BE ON SATURDAY AS UPSTREAM FLOW
AMPLIFIES ONCE AGAIN AND A WAVE MOVING ALONG THE AFOREMENTIONED
BAROCLINIC ZONE BRINGS A SOLID CHANCE OF SHOWERS TO THE LOWER GREAT
LAKES. THE BOUNDARY THEN RETREATS TOP THE SOUTH IN THE WAKE OF THE
WAVE ON SUNDAY...LEADING TO A DRY AND SLIGHTLY COOLER END OT THE
WEEKEND. BY COOLER...IT WILL BE SLIGHTLY COOLER AS HIGHS WILL REMAIN
A SOLID 10 DEGREES ABOVE AVERAGE...IN THE LOWER 40S. ANY COOLDOWN
WILL BE SHORT-LIVED AS WELL AS MODELS ARE IN DECENT AGREEMENT ON
PRODUCING ANOTHER SYSTEM SIMILAR TO THURSDAY`S SYSTEM EARLY NEXT
WEEK...LIKELY LEADING TO ANOTHER ROUND OF POTENTIAL RECORD WARMTH.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
EXPECT MAINLY MVFR CONDITIONS THROUGH 09Z. AFTER THIS STEADY RAIN
WILL MOVE IN AND ADD MOISTURE TO AN ALREADY MOIST ENVIRONMENT
WHICH WILL LOWER CIGS AND VSBY TUESDAY MORNING. LINGERING SNOWPACK
NEAR JHW AND CLIMATOLOGY WILL LIKELY LEAD TO LIFR CIGS AND
FOG. THE LOWEST CONDITIONS ELSEWHERE WILL IMMEDIATELY PRECEDE THE
WIND SHIFT...WITH IMPROVING CONDITIONS WHEN SOUTHWEST WINDS
INCREASE IN THE AFTERNOON AND HELP MIX THE BOUNDARY LAYER.
RAIN WILL END FROM W-E TUESDAY AFTERNOON WITH GRADUALLY IMPROVING
CONDITIONS IN MOST LOCATIONS. MVFR/IFR CONDITIONS WILL PROBABLY
LINGER AT JHW/ART INTO TUESDAY EVENING...WITH CLOUDS LIKELY TO
SCATTER AND/OR LIFT AT BUF/IAG/ROC DUE TO THE STRONGER WINDS.
OUTLOOK...
TUESDAY NIGHT...VFR/MVFR. A CHANCE OF SHOWERS.
WEDNESDAY AND THURSDAY...VFR/MVFR WITH RAIN SHOWERS LIKELY.
FRIDAY...VFR. SATURDAY...VFR EARLY LEADING TO MVFR IN SHOWERS.
&&
.MARINE...
WINDS HAVE DIMINISHED LATE THIS EVENING WITH NO HEADLINES ON THE
WATERS. SOUTHWESTERLY WINDS WILL PICK UP ON LAKE ERIE BEHIND A
WEAK SURFACE LOW TUESDAY AFTERNOON...WITH A BRIEF PERIOD OF NEAR-
SCA CONDITIONS.
AS THE NEXT STORM MOVES ACROSS THE UPPER MISSISSIPPI VALLEY AND
UPPER GREAT LAKES ON WEDNESDAY...WINDS WILL BACK TO THE SOUTHEAST
AND FRESHEN. THIS WILL DIRECT THE HIGHEST WAVES INTO CANADIAN
WATERS...BUT WIND SPEEDS IN EXCESS OF 20 KNOTS COULD LEAD TO
ANOTHER ROUND OF SMALL CRAFT ADVISORIES LATER WEDNESDAY INTO
WEDNESDAY NIGHT.
&&
.CLIMATE...
ALTHOUGH BUFFALO HAS GOTTEN ITS FIRST MEASURABLE SNOW...THIS
WINTER CONTINUES TO BE OFF TO AN EXTRAORDINARILY WARM START.
SPEAKING OF WHICH...YET ANOTHER ROUND OF UNSEASONABLE WARMTH IS
EXPECTED THIS WEEK...AS ANOTHER VERY WARM AIRMASS WILL BRING NEAR
RECORD TO POTENTIALLY RECORD-BREAKING HIGHS BOTH WEDNESDAY AND
THURSDAY (CHRISTMAS EVE). HERE ARE THE CURRENT RECORDS FOR
DECEMBER 23RD AND 24TH...
WEDNESDAY...
CITY.........RECORD HIGH (F)....RECORD WARM LOW (F).....
BUFFALO......59 / 1957...........46 / 1941
ROCHESTER....60 / 1957...........43 / 2006
WATERTOWN....58 / 1990...........42 / 2006
CHRISTMAS EVE...
BUFFALO......59 / 1964...........46 / 1979
ROCHESTER....58 / 1982...........47 / 2014
WATERTOWN....59 / 2014...........49 / 2014
WHEN CONSIDERING THE FORECAST THROUGH THE END OF THE MONTH...
DECEMBER 2015 ALSO STANDS A GOOD CHANCE TO BECOME THE WARMEST
DECEMBER ON RECORD IN WESTERN NEW YORK. CURRENT TRENDS SUGGEST
THAT THE MONTHLY AVERAGE TEMPERATURE MAY WELL TOP 40 DEGREES...
WHICH PUTS THE FOLLOWING RECORDS IN SERIOUS JEOPARDY...
WARMEST MEAN TEMPERATURE RECORDS FOR DECEMBER...
CITY TEMP YEAR
BUFFALO.....37.6 (1923)
ROCHESTER...39.0 (2006)
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...RSH/WCH
NEAR TERM...APFFEL/WCH
SHORT TERM...SMITH/WOOD
LONG TERM...WOOD
AVIATION...APFFEL
MARINE...APFFEL/RSH/WCH
CLIMATE...THOMAS/JJR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
700 PM EST WED DEC 23 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH THE WEEKEND. A WEAK
COLD FRONT WILL APPROACH FROM THE NORTH THURSDAY NIGHT THEN STALL
NEAR THE VIRGINIA BORDER FRIDAY. THE FRONT WILL LIFT BACK NORTH
OVER THE WEEKEND.
&&
.NEAR TERM /TONIGHT/...
AS OF 7 PM WED...ONLY MAIN CHANGE WAS TO EXTEND THUNDER INTO THE
MIDNIGHT HOUR THIS EVENING...AS SOME INSTABILITY WILL LINGER INTO
THE FIRST HALF OF THE NIGHT. HRRR INDICATES BKN LINE OF CONVECTION
ACROSS PIEDMONT WEAKENING AS IT APPROACHES E NC...THOUGH
ADDITIONAL DEVELOPMENT IS POSSIBLE...ESP NEAR THE COAST WHERE
MOISTURE FLUX WILL BE DEEP THROUGH THE OVERNIGHT. EXTREMELY WARM
OVERNIGHT LOWS NEAR 70 WILL LIKELY BREAK ALL-TIME LOW MINIMUMS FOR
DECEMBER TONIGHT. THIS IS EXTRAORDINARY GIVEN IT IS HAPPENING
TOWARDS THE END OF THE MONTH. SEE CLIMATE SECTION BELOW.
PREVIOUS DISCUSSION...AS OF 335 PM WEDNESDAY...SCATTERED CONVECTION CONTINUES TO PUSH
NORTH ACROSS EASTERN NC THIS AFTERNOON. LIGHTNING REMAINS LIMITED
TO ONE CLUSTER OF STORMS OVER THE PAMLICO SOUND, WITH WIDESPREAD
CLOUDS INHIBITING SIGNIFICANT DESTABILIZATION. DEWPOINTS REMAIN
HIGH ACROSS EASTERN NC, LOWER 70S, VERY ANOMALOUS FOR LATE
DECEMBER. SOUTHERLY WINDS ARE GUSTING 20-25 MPH BUT WILL DIMINISH
SLIGHTLY TONIGHT EXCEPT FOR COASTAL/OBX LOCATIONS.
THE UPPER TROUGH WILL CONTINUE TO LIFT NORTH FROM THE CENTRAL
PLAINS INTO THE GREAT LAKES TONIGHT. BEST UPPER SUPPORT IS
NORTHWEST OF THE REGION WITH A FEW WEAK SHORTWAVES LIFTING
NORTHEAST AROUND THE PERIPHERY OF THE UPPER TROUGH IN MEAN SW
FLOW. GIVEN AMPLE MOISTURE (PWATS ABOVE 1.75 INCHES, INSTABILITY
(LI`S OF -3 TO -5), AND 0-3 KM STORM-RELATIVE HELICITY OF 200-300
M2/S2, CANNOT RULE OUT SEVERE THUNDERSTORMS ACROSS THE REGION THIS
EVENING INTO TONIGHT. THE WEAK CONVECTION STREAMING NORTH ACROSS
THE CRYSTAL COAST INTO EASTERN NC HAS NOT MOVED INTO THE MORE
FAVORABLE REGION ALONG/WEST OF HWY 17. IT REMAINS TO BE SEEN IF
THE CONVECTION ACROSS THE MIDLANDS/PIEDMONT OF SC/NC WILL
MAINTAIN OR INTENSIFY AS IT MOVES EAST-NORTHEAST TOWARDS EASTERN
NC. SPC ISSUED A MESOSCALE DISCUSSION HIGHLIGHTING THE POTENTIAL
FOR FURTHER DEVELOPMENT WITH THIS LINE, WITH THE MAIN THREATS
BEING DAMAGING WIND GUSTS OR AN ISOLATED TORNADO EMBEDDED WITHIN
THE LINE OF STORMS. FOR NOW, WILL MAINTAIN HIGH POPS WITH MENTION
OF THUNDER. PERIODS OF HEAVY RAINFALL WITH LOCALIZED FLOODING OF
POOR DRAINAGE AND LOW LYING AREA WILL ALSO BE POSSIBLE. TEMPS
OVERNIGHT REMAIN WARM AGAIN, WITH LOWS IN THE UPPER 60S ACROSS
EASTERN NC WHICH IS ABOUT 30-35 DEGREES ABOVE NORMAL AND WILL
LIKELY BREAK RECORD HIGH MINIMUM TEMPERATURES FOR THE DAY...SEE
CLIMATE SECTION BELOW.
&&
.SHORT TERM /THURSDAY/...
AS OF 350 PM WEDNESDAY...NOT MUCH CHANGE IN THE OVERALL PATTERN
THURSDAY WITH MOIST SW FLOW CONTINUING, THOUGH THE UPPER RIDGE
OVER THE WESTERN ATLANTIC WILL BEGIN TO BUILD WEST ACROSS EASTERN
NC DURING THE DAY. PWATS REMAIN HIGH BUT SHEAR DIMINISHES AND WE
LOSE UPPER SUPPORT, IN THE FORM OF WEAK SHORTWAVES, FOR STORM
DEVELOPMENT. NONETHELESS, WILL CONTINUE A DECREASING TREND IN POPS
THROUGH THE DAY FROM HIGH CHANCE TO LOW CHANCE POPS BY LATE
AFTERNOON. AMPLE INSTABILITY AND MOISTURE WARRANT CONTINUED
MENTION OF THUNDERSTORMS, BUT SHOWER/STORM COVERAGE REMAINS
UNCERTAIN DUE TO LACK OF UPPER SUPPORT/TRIGGER FOR DEVELOPMENT.
MAX TEMPERATURES WILL BUILD INTO THE LOWER 80S ACROSS THE COASTAL
PLAINS, NEAR OR ABOVE THE ALL- TIME RECORD HIGH TEMPERATURES FOR
THE MONTH OF DECEMBER...SEE CLIMATE SECTION BELOW.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
AS OF 300 PM WED...EXPECT RECORD BREAKING WARMTH THROUGH MUCH OF
THE PERIOD AS STRONG UPPER RIDGE OVER THE ATLANTIC BUILDS WEST
TOWARD THE COAST INTO THE WEEKEND.
THURSDAY NIGHT THROUGH CHRISTMAS DAY...COVERAGE OF PRECIPITATION
WILL DROP A BIT THURSDAY NIGHT AND FRIDAY AS UPR RDG GRAD BUILDS
W. UPR RDG BUILDS CLOSER WHICH WILL ACT TO SUPPRESS CONVECTION
AND WITH MORE SUN TEMPS WILL AGAIN BE VERY WARM REACHING AROUND 80
WARMER SPOTS ON CHRISTMAS DAY.
SATURDAY THROUGH SUNDAY...STRONG UPPER LEVEL RIDGE HOLDS ACROSS
THE SOUTHEASTERN UNITED STATES THROUGH THE WEEKEND AS LOW
PRESSURE MOVES FROM THE MISSISSIPPI VALLEY INTO THE GREAT LAKES
REGION. THIS WILL KEEP UNSEASONABLY WARM TEMPERATURES IN PLACE
WITH DAYTIME HIGHS WELL INTO THE 70S SATURDAY AND SUNDAY WITH LOWS
IN THE 60S. THERE WILL BE ONLY A SMALL CHANCE OF SHOWERS EACH DAY
GIVEN THE CONTINUED RATHER MOIST AIRMASS WITH FORECAST
PRECIPITABLE WATER VALUES AOA 1.50 INCHES.
MONDAY THROUGH WEDNESDAY...UPR RDG WILL BEGIN TO SHIFT BACK E
WITH MDLS SHOWING BACKDOOR FRONT DROPPING INTO THE REGION LATE
SUNDAY NIGHT OR EARLY MON THEN LIFTING BACK N TUE AHEAD OF
STRONGER APPROACHING FRONT. CONT PREV FCST OF CHC POPS EARLY NEXT
WEEK WITH STILL VERY MILD TEMPS IN THE 60S TO LOWER 70S...POSS
SOME MID 70S TUE/WED. A COLD FRONT APPROACHES FROM THE WEST ON
WEDNESDAY BUT TIMING OF THE FRONTAL PASSAGE VERY MUCH IN QUESTION
GIVEN THE POTENTIAL ERROR IN THE DAY 7 FORECAST. WILL CONTINUE
WITH ABOVE NORMAL TEMPS AND CHC POPS THRU MIDWEEK FOR NOW.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY/...
AS OF 7 PM WED...HIGH CONFIDENCE OF MVFR CONDITIONS WILL PERSIST
FIRST HALF OF TAF PD. SHOWERS/THUNDERSTORMS ARE EXPECTED TO
DIMINISH TONIGHT...THOUGH HUNG ONTO VCTS FOR SEVERAL MORE HOURS
ACROSS WESTERN SITES AS SOME CONVECTION MAY HOLD TOGETHER COMING
INTO THE COASTAL PLAIN FROM THE PIEDMONT. CEILINGS ARE EXPECTED
TO INCREASE BACK TO VFR THOUGH REMAIN BKN ON THUR. SOUTH WINDS
WILL AGAIN BECOME GUSTY BY LATE MORNING.
LONG TERM /THU NIGHT THROUGH MONDAY/...
AS OF 300 PM WED...WITH STRONG UPPER RIDGE BUILDING OVER THE AREA,
THE COVERAGE OF SHRA/TSRA WILL BE LIMITED THRU MUCH OF THE
UPCOMING WEEKEND. HOWEVER WITH LOW LEVELS REMAINING VERY MOIST
BOUTS OF SUB VFR STRATUS AND FOG WILL BE LIKELY LATE NIGHT/EARLY
MORN THRU SUNDAY. MAINLY VFR LATE MORN THRU EVENING HOURS WITH
ONLY SMALL CHC OF SHRA/TSRA THRU THE WEEKEND. A BACK DOOR COLD
FRONT DROPS THRU THE AREA LATE SUNDAY NIGHT OR EARLY MONDAY
BRINGING A POTENTIAL FOR LOW CLOUDS AND FOG BEHIND THE FRONT EARLY
NEXT WEEK.
&&
.MARINE...
SHORT TERM /THROUGH THURSDAY/
AS OF 355 PM WEDNESDAY...LATEST SURFACE AND BUOY DATA INDICATE SE
TO SSW WINDS ACROSS THE EASTERN NC WATERS 10-20 KT WITH GUSTS
NEAR 30 KT FOR THE OUTER BUOYS 41025/41064. THE SURFACE RIDGE
REMAINS CENTERED OFF THE SOUTHEAST COAST WHILE A COLD FRONT
CONTINUES TO APPROACH FROM THE WEST THROUGH THE SHORT TERM.
SOUTHERLY WINDS WILL CONTINUE 15-25 KT OVERNIGHT INTO THURSDAY
MORNING, THEN SLOWLY DIMINISH THROUGHOUT THE DAY AS THE PRESSURE
GRADIENT RELAXES. SEAS CURRENTLY AROUND 3-6 FT NORTH OF HATTERAS
AND 6-8 FT SOUTH, WILL BUILD IN RESPONSE TO THE STRONGER SOUTHERLY
FLOW, PEAKING AROUND 6-9 FT TONIGHT. STRONGEST WINDS/SEAS WILL
OCCUR OVER THE COASTAL WATERS AND WILL MAINTAIN THE SCA THROUGH
THE NEAR TERM. THE SOUNDS AND RIVERS EXPECTED TO REMAIN JUST
BELOW ADVISORY CRITERIA BUT MAY BE CLOSE ACROSS THE PAMLICO SOUND,
ESPECIALLY IN GUSTS. LOCAL SWAN/NWPS ABOUT 1 FT LESS THAN
WAVEWATCH, BUT APPEARS TO HAVE A BETTER HANDLE ON CURRENT
CONDITIONS SO WILL USE LOCAL GUIDANCE THROUGH THE NEAR TERM.
LONG TERM /THU NIGHT THROUGH MONDAY/...
AS OF 300 PM WED...SW WINDS AND ELEVATED SEAS WILL GRAD SUBSIDE
THU NIGHT AND FRI AS WEAK FRONT STALLS TO THE NORTH AND SFC HIGH
PRESSURE BUILDS OFF THE SE COAST. THE PRESSURE GRADIENT WITH THE
OFFSHORE HIGH WILL SUPPORT A LIGHT TO MODERATE (10-15 KT) S/SW
FLOW THRU MUCH OF THE UPCOMING WEEKEND WITH SEAS MAINLY 3 TO 5 FT.
A BACKDOOR FRONT DROPS THRU THE MARINE AREA LATE SUNDAY NIGHT OR
EARLY MONDAY WITH WINDS SHIFTING N/NE WHILE MAINTAINING MODERATE
SPEEDS AOB 15 KTS.
&&
.CLIMATE...
WARM AND HUMID WEATHER FOR DECEMBER WILL DOMINATE THE REMAINDER
OF CHRISTMAS WEEK. THE FOLLOWING ARE RECORD HIGH MAX TEMPS, AS
WELL AS RECORD HIGH MIN TEMPS, FOR 12/23 THROUGH 12/25, WHEN THE
WARMEST TEMPS ARE EXPECTED. ALSO INCLUDED ARE THE ALL-TIME HIGHS
FOR DECEMBER.
RECORD HIGH MAX TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 79/2013 (KEWN ASOS)
CAPE HATTERAS 75/1990 (KHSE ASOS)
GREENVILLE 79/1967 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1990 (COOP NOT KMRH ASOS)
KINSTON 82/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 82/1981 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/23 WEDNESDAY
LOCATION TEMP/YEAR
NEW BERN 63/1990 (KEWN ASOS)
CAPE HATTERAS 66/1990 (KHSE ASOS)
GREENVILLE 61/1990 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 64/2013 (COOP - NOT KMRH ASOS)
KINSTON 65/2013 (COOP- NOT KISO AWOS)
JACKSONVILLE 63/1956 (KNCA AWOS)
RECORD HIGH MAX TEMPS F0R 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 76/1964 (KEWN ASOS)
CAPE HATTERAS 72/1990 (KHSE ASOS)
GREENVILLE 73/1988 (COOP NOT KPGV AWOS)
MOREHEAD CITY 72/1990 (COOP NOT KMRH ASOS)
KINSTON 78/2013 (COOP NOT KISO AWOS)
JACKSONVILLE 74/1990 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 55/2014 (KEWN ASOS)
CAPE HATTERAS 62/1986 (KHSE ASOS)
GREENVILLE 56/1956 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/1956 (COOP - NOT KMRH ASOS)
KINSTON 63/1990 (COOP- NOT KISO AWOS)
JACKSONVILLE 54/2014 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 78/1955 (KEWN ASOS)
CAPE HATTERAS 73/1964 (KHSE ASOS)
GREENVILLE 77/1964 (COOP NOT KPGV AWOS)
MOREHEAD CITY 74/1974 (COOP NOT KMRH ASOS)
KINSTON 78/1932 (COOP NOT KISO AWOS)
JACKSONVILLE 76/1974 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 63/1964 (KEWN ASOS)
CAPE HATTERAS 61/1964 (KHSE ASOS)
GREENVILLE 59/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/2008 (COOP - NOT KMRH ASOS)
KINSTON 61/1932 (COOP- NOT KISO AWOS)
JACKSONVILLE 61/1987 (KNCA AWOS)
**ALL-TIME RECORD HIGH MAXIMUM TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 83/1971 (KEWN ASOS)
CAPE HATTERAS 78/1991 (KHSE ASOS)
GREENVILLE 82/1998 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 79/1998 (COOP - NOT KMRH ASOS)
KINSTON 87/1918 (COOP - NOT KISO AWOS)
JACKSONVILLE 82/1998 (KNCA AWOS)
**ALL-TIME RECORD HIGH MINIMUM TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 69/2013 (KEWN ASOS)
CAPE HATTERAS 68/2015 (KHSE ASOS)
GREENVILLE 67/1991 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 67/2001 (COOP - NOT KMRH ASOS)
KINSTON 68/1991 (COOP - NOT KISO AWOS)
JACKSONVILLE 68/2013 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR AMZ150.
&&
$$
SYNOPSIS...DAG
NEAR TERM...DAG/TL
SHORT TERM...DAG
LONG TERM...RF/BTC
AVIATION...RF/BTC/TL
MARINE...RF/BTC/DAG
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS RALEIGH NC
315 PM EST TUE DEC 22 2015
.SYNOPSIS...A WEDGE FRONT WILL REMAIN QUASI-STATIONARY OVER THE
PIEDMONT THROUGH TONIGHT...THEN BE OVERTAKEN BY A MARITIME WARM
FRONT THAT WILL SURGE ACROSS THE CAROLINAS AND VIRGINIA ON
WEDNESDAY. ANOMALOUSLY STRONG SUB-TROPICAL HIGH PRESSURE OVER THE
WEST-CENTRAL ATLANTIC OCEAN WILL THEN DIRECT UNSEASONABLY WARM AND
MOIST SOUTHERLY FLOW THROUGHOUT THE SOUTHEASTERN UNITED STATES
THROUGH CHRISTMAS.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 315 PM TUESDAY...
...HEAVY RAIN AND SOME LOCALIZED FLOODING POSSIBLE OVER THE WESTERN
PIEDMONT LATE TONIGHT INTO WEDNESDAY...
EARLIER RAINFALL IS NOW NEAR THE COAST AS THE ASSOCIATED SHEAR AXIS
AND DEEPEST MOISTURE HAVE SHIFTED EAST. SLIGHTLY DRIER MID LEVEL
AIR...WHICH HAS AIDED PERIODS OF DENSE FOG IN THE WEDGE AIRMASS
OVER THE WESTERN PIEDMONT...WILL GIVE WAY TO ANOTHER SURGE OF DEEP
MOISTURE ACCOMPANYING ANOTHER WAVE IN THE SOUTHWEST FLOW. PW WILL
INCREASE BACK TO NEAR 1.8 INCHES...WHICH IS NEARLY A CLIMATOLOGICAL
MAX FOR THIS TIME OF YEAR. WHILE THE MAIN AMPLIFICATION OF THE UPPER
TROUGH MOVING OUT OF THE SOUTHERN US WILL BE WELL WEST OF HERE... A
NOTABLE SHORTWAVE CURRENTLY OVER THE LOWER MISSISSIPPI VALLEY IS
FORECAST TOP LIFT ALONG THE SPINE OF THE APPALACHIANS AND SERVE AS A
FOCUS FOR HEAVY RAINFALL. THE WESTERN PIEDMONT LIES ON THE EAST
EDGE OF THE GENERAL MODEL CONSENSUS OF 2+ INCHES OF QPF...BUT GIVEN
THE ANOMALIES IN THIS PATTERN AND THE 1-2 INCHES THAT FEEL LAST
NIGHT...A FLASH FLOOD WATCH WILL BE ISSUED STARTING AT MIDNIGHT
TONIGHT FOR THE WESTERN PIEDMONT. PRIOR TO THE RAIN...THE HRRR SHOWS
WIDESPREAD FOG SETTLING BACK IN WITHIN THE WEDGE AIRMASS. A DENSE
FOG ADVISORY MAY BE NEEDED BEFORE PRECIP SPREADS IN FROM THE SOUTH
AND HELPS TO AT LEAST MIX OUT THE 1/4 MILE VSBYS. TEMPS WILL HOLD
STEADY OR RISE LATE TONIGHT WITH THE STRENGTHENING WARM
ADVECTION..WITH READINGS IN THE UPPER 50S TO UPPER 60S.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 300 PM TUESDAY...
ONGOING PRECIP WEDNESDAY MORNING WILL BE FOCUSED ACROSS THE WESTERN
PIEDMONT AS A DISTURBANCE LIFTS ALONG THE APPALACHIANS. INCREDIBLY
HIGH PW DISCUSSED INT HE NEAR TERM FORECAST WILL REMAIN OVER THE
AREA WITH NO AIRMASS CHANGE IN SIGHT. THE FOCUS FOR PRECIP...LIKELY
MORE CONVECTIVE IN NATURE...SHOULD SHIFT EAST DURING THE DAY AS THE
DISTURBANCE LIFTS OFF TO THE NORTH AND A TRAILING SHEAR AXIS MOVES
EAST. MID-LEVEL LAPSE RATES ARE EXPECTED TO BE WEAK EAST OF THE
APPALACHIANS (THOUGH THE GFS FORECASTS 6+ C/KM)...BUT GIVEN TEMPS
CLIMBING INTO THE MID 70S AND DEWPOINTS APPROACHING 70...FORECAST
SOUNDINGS SHOW A RANGE OF 500-1000 J/KG OF MUCAPE IN THE COASTAL
PLAIN WEDNESDAY AFTERNOON. EVEN IF THIS IS A LITTLE
OVERDONE...CONVECTION SHOULD BE UNINHIBITED AND COULD TAP INTO THE
40-50KT DEEP SHEAR AND RESULT IN AT LEAST AN ISOLATED SEVERE THREAT.
CONFIDENCE IS LOW GIVEN THE TIME OF YEAR...BUT THE PATTERN IS
UNUSUALLY WARM AND MOIST. EVEN WITHOUT STRONG STORMS...CONVECTIVE
CELLS WILL BE CAPABLE OF PRODUCING ANOTHER INCH OR MORE OF RAIN IN
ISOLATED AREAS...SO A LOCALIZED FLASH FLOOD THREAT MAY STILL BE
THERE.
THE OVERALL COVERAGE OF PRECIP WILL LESSEN WEDNESDAY NIGHT...THOUGH
MODELS CONTINUE TO SHOW POTENTIAL FOR SOME SCATTERED SHOWERS WELL ON
THROUGH THE NIGHT. LOWS WILL BE VERY MILD IN THE MID AND UPPER 60S.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
AS OF 200 PM TUESDAY...
THU AND THU NIGHT: STILL SOME DIFFERENCES IN THE MODELS WITH RESPECT
TO RAIN...THUS THERE IS STILL SOME UNCERTAINTY. HOWEVER...IT IS
LOOKING LIKE THURSDAY COULD BE RELATIVELY DRY...BUT WILL KEEP A
CHANCE OF SOME RAIN IN THE FORECAST. RAIN SHOULD NOT BE NEARLY AS
WIDESPREAD AS IN PRECEDING DAYS. BEST CHANCES FOR CONVECTION WILL
BE IN THE NORTHWEST...ESPECIALLY IN THE AFT/EVE AND INTO THE
OVERNIGHT. HIGHEST TEMPERATURES OF THE LONG TERM ARE STILL EXPECTED
ON THURSDAY AS THE SOUTHERLY WARM ADVECTION PEAKS. HIGHS IN THE LOW
TO MID 70S NW TO AROUND 80 DEGREES IN THE SE. LOWS GENERALLY IN THE
MID 60S.
FRI THROUGH SUN: AS OF THE LATEST MEDIUM RANGE MODEL RUNS...THIS
PERIOD WILL LIKELY BE DOMINATED BY SUB-TROPICAL RIDGING ALOFT OVER
THE SOUTHEAST U.S.. SOUTHERLY TO SOUTHWESTERLY RETURN FLOW AROUND
THE SURFACE HIGH WILL CONTINUE TO USHER WARM MOIST AIR INTO THE
REGION...RESULTING IN A VERY WARM AND MOIST PERIOD FOR THIS TIME OF
YEAR. THE OCCASIONAL UPPER LEVEL DISTURBANCE RIDING THE RIDGE MAY
GENERATING ENOUGH LIFT IN THE ANOMALOUSLY WARM MOIST AIRMASS TO KICK
OFF SOME SHOWERS...MAINLY IN THE AFT/EVE HOURS. THE GENERAL PRECIP
TREND FOR THIS PERIOD WILL BE CHARACTERIZED BY A LULL DURING THE
OVERNIGHT AND MORNING HOURS AND HIGHEST CHANCES DURING THE AFT/EVE.
THE INITIAL FRONTAL SURGE THAT WAS ORIGINALLY EXPECTED TO PUSH SOUTH
INTO THE AREA ON FRIDAY WILL LIKELY STAY WELL TO THE NORTH THROUGH
AT LEAST SUNDAY EVENING. LOWS THROUGH THE PERIOD WILL BE FAIRLY
CONSISTENT...AND WELL ABOVE NORMAL...IN THE MID 50S TO LOW 60S.
HIGHS WILL LIKELY FLUCTUATE A BIT MORE...BUT GENERALLY STAY BETWEEN
THE MID 60S AND UPPER 70S...WHICH IS 10-15 DEGREES ABOVE NORMAL FOR
LATE DECEMBER.
MONDAY AND MONDAY NIGHT...THE GFS AND ECMWF VARY ON WHETHER THEY
THINK A SECONDARY SURGE WILL PUSH FAR ENOUGH SOUTH TO MOVE INTO
CENTRAL NC FOR THE BEGINNING OF THE WEEK. WILL HOLD OFF ON MAKING
ANY DRASTIC CHANGES TO THE PREVIOUS FORECAST FOR EARLY NEXT WEEK
UNTIL THERE IS BETTER AGREEMENT ONE WAY OR THE OTHER.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
AS OF 1250 PM TUESDAY...
WHILE THE PRIMARY AXIS OF PRECIPITATION HAS MOVED EAST TOWARD THE
COAST...A MOIST AIRMASS CONTINUES TO PROMOTE AREA OF LOW CLOUDS
ACROSS MUCH OF CENTRAL NC. WHERE LOW CLOUDS ARE OBSERVED...MAINLY
BETWEEN KGSO AND KRDU...THEY ARE GENERALLY IN THE IFR RANGE. FOG
THAT DEVELOPED EARLIER THIS MORNING AT KGSO AND KINT IS HOLDING
STRONG DESPITE A LIGHT SOUTHWESTERLY WIND...THOUGH SOME TRAFFIC
CAMERAS IN THE AREA SUGGEST THIS MIGHT JUST BE A VERY VERY LOW
OVERCAST...BUT NONETHELESS PROBLEMATIC. EXPECT CONDITIONS WILL
REMAIN FAIRLY STEADY STATE THIS AFTERNOON AND INTO THE EARLY EVENING
HOURS. MODELS THEN SUGGEST FOG ADVECTING ACROSS THE AREA FROM THE
SOUTH AS ANOTHER SURGE OF UNSEASONABLY RICH MOISTURE MOVES IN FROM
THE SOUTH. RAIN WILL BE PREDOMINATE ACROSS THE WESTERN PIEDMONT FOR
MUCH OF THE NIGHT...WHICH SHOULD LIMIT THE FOG FROM STAYING VERY
DENSE THERE...WITH PRECIP EVENTUALLY SHIFTING EAST WEDNESDAY
MORNING. A FEW THUNDERSTORMS ARE POSSIBLY DURING THE DAY ON
WEDNESDAY..MAINLY EAST...WITH WIND GUSTS IN THE 20-30KT RANGE ALSO
POSSIBLE.
OUTLOOK: A MOIST DEEP SOUTHWESTERLY FLOW DOWNSTREAM OF THE LONG WAVE
TROUGH IN PLACE ACROSS THE CENTRAL CONUS WILL SUPPORT A PROLONGED
PERIOD OF ADVERSE AVIATION CONDITIONS THROUGH MUCH OF THE PERIOD.
NEXT SURGE OF MOISTURE MOVES OUT OF THE GULF OF MEXICO LATE TONIGHT
THROUGH THURSDAY...WHICH COULD POTENTIALLY PRODUCE EXTENDED PERIODS
OF MODERATE TO HEAVY RAIN...ESPECIALLY ACROSS WESTERN NC. SUB-VFR
CONDITIONS IN LOW CLOUDS/STRATUS WILL ALSO BE LIKELY EACH MORNING.
&&
.CLIMATE...
HERE ARE THE AREA RECORD MAXIMUMS AND HIGH MINIMUMS FOR DECEMBER 24TH
AND 25TH. RECORDS HAVE BEEN KEPT IN THE GREENSBORO AREA SINCE
1903... IN THE RALEIGH AREA SINCE 1887... AND IN THE FAYETTEVILLE
AREA SINCE 1910.
DEC 24: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 71 (1964) 52 (1904)
RALEIGH 75 (1931) 59 (1891)
FAYETTEVILLE 78 (1931) 66 (1990)
DEC 25: RECORD MAXIMUM HIGH MINIMUM
GREENSBORO 74 (1955) 58 (1932)
RALEIGH 75 (1955) 63 (1932)
FAYETTEVILLE 79 (1932) 68 (1932)
&&
.RAH WATCHES/WARNINGS/ADVISORIES... NONE.
&&
$$
SYNOPSIS...2
NEAR TERM...22
SHORT TERM...22
LONG TERM...10
AVIATION...CBL/22
CLIMATE...HARTFIELD/BLAES
AREA FORECAST DISCUSSION
NWS BISMARCK ND
328 PM CST TUE DEC 22 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 253 PM CST TUE DEC 22 2015
HEAVY SNOW NORTH CENTRAL THROUGH EARLY THIS EVENING HIGHLIGHTS THE
SHORT TERM FORECAST.
AS OF 2130 UTC...A SECONDARY SHORTWAVE EVIDENT ON WATER VAPOR HAS
PROPAGATED NORTHEAST OUT OF NORTH CENTRAL SOUTH DAKOTA INTO SOUTH
CENTRAL NORTH DAKOTA...AS REFLECTED IN THE INTENSIFICATION OF
SNOWFALL ACROSS SOUTH CENTRAL NORTH DAKOTA OVER THE PAST ONE TO
TWO HOURS. THIS WAVE WILL CONTINUE TO PROPAGATE NORTHEAST AND
INTERACT WITH THE TROWAL ACROSS NORTH CENTRAL AND NORTHEAST NORTH
DAKOTA TO CONTINUE TO SUPPORT HEAVY SNOWFALL THROUGH EARLY THIS
EVENING. THE 17-20 UTC HRRR AND RAP ITERATIONS HAVE HANDLED THE
MESOSCALE BANDING OF SNOWFALL WELL THROUGH THE AFTERNOON AND WILL
FOLLOW THEIR SOLUTIONS THROUGH THE EVENING...BLENDED TO THE 12 UTC
GLOBAL SUITE LATE TONIGHT INTO WEDNESDAY MORNING. OVERALL...STORM
TOTAL SNOWFALL ACCUMULATIONS OF 6 TO 8 INCHES REMAIN UNCHANGED FOR
THE TOWNER...RUGBY...BOTTINEAU AND ROLETTE AREAS...WITH LOCALLY
HIGHER AMOUNTS. ELSEWHERE FOR TONIGHT INTO WEDNESDAY
MORNING...LIGHT SNOW IS EXPECTED. THIS IS IN ASSOCIATION WITH THE
WEAKENING TROWAL AND A WAVE CURRENTLY ACROSS NORTH CENTRAL
MONTANA THAT WILL PROPAGATE SOUTHEAST. ADDITIONAL SNOWFALL
ACCUMULATIONS OF AROUND ONE...TO POSSIBLY TWO INCHES ACROSS THE
WEST INTO THE SOUTH CENTRAL ARE FORECAST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 253 PM CST TUE DEC 22 2015
COOLING TEMPERATURES INTO THE WEEKEND HIGHLIGHT THE EXTENDED
FORECAST.
THE 12 UTC DETERMINISTIC AND ENSEMBLE SUITES ARE IN AGREEMENT ON
A BROAD...UPPER LEVEL WESTERN AND CENTRAL CONUS TROUGH TO BEGIN
THE PERIOD TO POSSIBLY TRANSITION TO SPLIT FLOW BY THE
WEEKEND...POTENTIALLY PLACING THE NORTHERN PLAINS IN NORTHWEST
FLOW ALOFT WITH THE NORTHERN STREAM. THIS SUPPORTS A POSSIBLE COOL
DOWN INTO THE WEEKEND. OVERALL...THE CHRISTMAS TRAVEL OUTLOOK
LOOKS GOOD WITH RATHER QUIET WEATHER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 253 PM CST TUE DEC 22 2015
IFR CONDITIONS IN SNOW THROUGH WEDNESDAY MORNING EXPECTED AT KMOT.
IFR CONDITIONS EXPECTED AT KBIS THIS AFTERNOON IN LIGHT SNOW...AND
AGAIN LATE TONIGHT INTO WEDNESDAY MORNING. IFR IN LIGHT SNOW
DEVELOPING AT KISN LATE THIS AFTERNOON THROUGH TONIGHT. MVFR TO
IFR CONDITIONS IN STRATUS AT KDIK...WITH LIGHT SNOW POSSIBLE LATE
TONIGHT INTO WEDNESDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 AM CST WEDNESDAY FOR NDZ004-005-012-
013.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ022-
023-025.
&&
$$
SHORT TERM...AYD
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
124 PM CST TUE DEC 22 2015
.UPDATE...
ISSUED AT 114 PM CST TUE DEC 22 2015
UPGRADED BOTTINEAU...ROLETTE...PIECE AND MCHENRY COUNTIES TO A
WINTER STORM WARNING THROUGH 12 UTC WEDNESDAY WITH THIS UPDATE.
RADAR AND SATELLITE TRENDS THROUGH 19 UTC DEPICT A BAND OF HEAVY
SNOW ACROSS THE FAR NORTH CENTRAL...TURTLE MOUNTAINS AND INTO THE
DEVILS LAKE BASIN IN ASSOCIATION WITH A DEVELOPING TROWAL. A
SECONDARY WAVE OBSERVED ACROSS SOUTH CENTRAL NORTH DAKOTA IS
EXPECTED TO PROPAGATE NORTHEAST THROUGH THE AFTERNOON TO CONTINUE
TO SUSTAIN THE HEAVY SNOW THREAT WITH RATES AROUND ONE INCH PER
HOUR. SEE SPC MCD 2025. WITH A CLEAR PIVOT POINT SETTING UP JUST
SOUTHEAST OF MINOT...THE AFOREMENTIONED COUNTIES ARE EXPECTED TO
REMAIN IMPACTED BY MESOSCALE SNOW BANDING THROUGH 22-23 UTC.
THEREAFTER...SNOWFALL INTENSITY WILL DECREASE...YET SNOW WILL CONTINUE
THROUGH THE NIGHT. THE 17-18 UTC HRRR AND RAP ITERATIONS DEPICT
WELL THIS SCENARIO...AND PLACE 0.40 TO 0.60 INCHES OF LIQUID
EQUIVALENT OVER THE WARNING AREA...TRANSLATING TO AROUND 6 TO 8
INCHES OF SNOW.
UPDATE ISSUED AT 929 AM CST TUE DEC 22 2015
WEBCAM TRENDS THROUGH 1520 UTC INDICATE THAT THE 700-900 MB DRY
LAYER HAS NOT YET BEEN SUFFICIENTLY ERODED ACROSS CENTRAL NORTH
DAKOTA FOR SNOWFALL TO REACH THE SURFACE. 15 UTC RAP SOUNDINGS
SUGGESTS THE LAYER WILL QUICKLY SATURATE IN THE 16-17 UTC
TIMEFRAME. OVERALL...THE 12 UTC WRF-NMM/ARW...NAM NEST AND 11-14
UTC HRRR ITERATIONS SUPPORT THE TREND FROM THE 00 AND 06 UTC
GLOBAL SUITES OF A SLIGHT NORTHWARD SHIFT IN THE SNOWBAND TODAY AS
COMPARED TO RUNS YESTERDAY...WITH NOW LESS THAN ONE INCH OF SNOW
EXPECTED FOR BISMARCK/MANDAN.
UPDATE ISSUED AT 646 AM CST TUE DEC 22 2015
NO SIGNIFICANT CHANGES WITH THIS UPDATE OTHER THAN TO BLEND THE
LATEST RADAR TRENDS INTO THE HOURLY POP FORECAST THROUGH 15 UTC.
RADAR ECHOES HAVE BEEN STEADILY INCREASING OVER SOUTH CENTRAL ND
DURING THE LAST 90 MINUTES...AND WHILE NO PRECIPITATION REPORTS
HAVE BEEN RECEIVED YET...THE 12 UTC BISMARCK SOUNDING IS NEARLY
SATURATED ALOFT...SO SNOW SHOULD QUICKLY DEVELOP BY MID MORNING.
NOTE THAT OVERNIGHT RAP AND HRRR SIMULATIONS /INCLUDING THE ESRL
HRRR/ HAVE BEEN INCONSISTENT FROM RUN TO RUN AND WITH THE GLOBAL
MODEL GUIDANCE...ESPECIALLY ON THE WESTERN AND SOUTHERN BOUNDARY
OF EXPECTED SNOWFALL TODAY...SO THE ACCUMULATION FORECAST STAYED
THE SAME WITH THIS UPDATE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST TUE DEC 22 2015
ACCUMULATING SNOW IS THE MAIN CONCERN IN THE SHORT TERM.
CURRENTLY...THE SURFACE LOW WAS AT THE BORDER OF SOUTHEASTERN
MONTANA AND NORTHEASTERN WYOMING. STRONG SOUTHWESTERLY SURFACE
WINDS WERE NOTED OVER EASTERN WYOMING AND FAR WESTERN SOUTH
DAKOTA. THESE SURFACE WINDS WERE INDICATIVE OF A STRONG LOW LEVEL
JET DEPICTED IN THE MODELS AT H925 AND H850. AT UPPER LEVELS...A
STRONG SHORTWAVE WAS CENTERED OVER WYOMING. LIGHT RADAR RETURNS
WERE OVER EASTERN MONTANA INTO NORTHEASTERN WYOMING...BUT
INTENSITIES WERE INCREASING SOUTH AND EAST OF BILLINGS INTO
NORTHEASTERN WYOMING...IN THE VICINITY OF THE UPPER LEVEL
SHORTWAVE.
THE UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE NORTHEAST ACROSS THE
DAKOTAS TODAY AND MOVE INTO SOUTHERN MANITOBA TONIGHT. THE SURFACE
AND H700 LOW ARE FORECAST TO TRACK NORTHEASTWARD ACROSS NORTH DAKOTA
TODAY...REACHING THE ND/MN/MANITOBA BORDER BY MIDNIGHT TUESDAY
NIGHT. STRONG FRONTOGENETIC FORCING WITH VERTICAL MOTION IN THE
DENDRITIC GROWTH ZONE ARE EXPECTED ALONG THIS TRACK. THE MODELS
INDICATE A DEEPER DENDRITIC GROWTH ZONE LATE THIS MORNING/AFTERNOON
IN NORTH CENTRAL NORTH DAKOTA. FARTHER SOUTH THE TEMPERATURE
PROFILES ARE WARMER EARLY ON THIS MORNING WHEN THE BEST VERTICAL
MOTION IS FORECAST. SO THE LATEST RUN OF THE MODELS VALIDATE THE
ONGOING FORECAST OF MORE PRECIPITATION/SNOWFALL NORTH CENTRAL VERSUS
ACROSS THE SOUTH. THE WARM AIR LAYER OFF THE SURFACE ASSOCIATED WITH
THE LOW LEVEL JET WILL BRING A CHANCE OF MIXED PRECIPITATION TO
PARTS OF SOUTHERN NORTH DAKOTA TODAY...AND THIS WILL LIMIT THE
AMOUNT OF SNOW EXPECTED IN THE SOUTHERN TIER OF COUNTIES.
THE LATEST SHORT TERM HIGH RESOLUTION MODELS ARE NOT AS ROBUST WITH
PRECIP OUTPUT AS THE GLOBAL MODELS...AND USED A BLEND OF HIGH RES
AND GLOBAL MODEL SNOW RATIO METHODS. SNOW IS EXPECTED TO BEGIN OVER
SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA AROUND 6 AM CST...AND
INCREASE QUICKLY BY AROUND 9 AM CST. THE GREATEST FORCING MOVES INTO
NORTHERN NORTH DAKOTA AROUND/AFTER 9 AM CST AND THE AFTERNOON HOURS
SHOULD SEE THE MOST SNOW ACCUMULATIONS ACROSS THE NORTH. THE
SOUTHWEST AND SOUTH CENTRAL SHOULD SEE UP TO AN INCH OR 2 OF SNOW BY
TONIGHT...WITH THE GREATEST SNOWFALL OF 3 TO OVER 5 INCHES OF SNOW
IN THE NORTH CENTRAL...WITH THE HIGHER AMOUNTS IN THE TURTLE
MOUNTAINS AREA.
WILL ADD BOTTINEAU COUNTY TO THE ONGOING WINTER WEATHER
ADVISORY...WHICH WILL INCLUDE WESTHOPE AND BOTTINEAU...VELVA AND
TOWNER...AND POINTS EAST TO RUGBY AND THE TURTLE MOUNTAINS. THERE
MAY BE A COUPLE LOCALES THAT REACH 6 INCHES OR A BIT MORE...BUT IN
GENERAL 3 TO 5.5 INCHES OF SNOW IS EXPECTED MOST AREAS IN THE
ADVISORY.
SNOW SHOULD TAPER TO LIGHT SNOW OR FLURRIES AS THE SYSTEM MOVES
NORTHEAST...BUT LINGER THROUGH THE NIGHT TUESDAY NIGHT AS A WEAK
TROWAL FEATURE KEEPS THE WRAP AROUND PRECIPITATION AS FAR WEST AS
MONTANA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM CST TUE DEC 22 2015
COOL AND GENERALLY QUIET WEATHER WILL PREVAIL IN THE LONG TERM.
FLURRIES OR LIGHT SNOW SHOWERS REMAIN POSSIBLE ON WEDNESDAY WITH
LINGERING CYCLONIC FLOW ACROSS THE REGION. ON THE LARGE SCALE...A
BROAD AND LOW-AMPLITUDE 500-MB TROUGH OVER THE WESTERN AND CENTRAL
UNITED STATES WILL BE REPLACED BY A MUCH DEEPER AND DYNAMICALLY-
ENERGIZED TROUGH CENTERED ON THE FOUR-CORNERS REGION BY SATURDAY.
THAT TRANSITION COULD YIELD LIGHT SNOW IN THE NORTHERN PLAINS LATE
ON CHRISTMAS DAY OR MORE SO ON FRIDAY NIGHT AS FLOW ALOFT BECOMES
SOUTHWESTERLY. HOWEVER...CONFIDENCE IN THE NORTHERN EXTENT OF ANY
LIGHT SNOW IS MODEST AT BEST AS SPLIT FLOW TAKES SHAPE ALOFT...AS
EXEMPLIFIED BY THE 00 UTC ECMWF...WHICH WAS A DRY SOLUTION ACROSS
MUCH OF WESTERN AND CENTRAL ND DURING THAT TIME FRAME.
TEMPERATURES WILL BE SEASONABLY COOL MOST OF THE PERIOD...AND WILL
BE COLDEST FRIDAY INTO SATURDAY...WHEN LOWS WILL BE AROUND 0 F AND
HIGHS WILL ONLY BE IN THE TEENS F PER A 00 UTC MULTI-MODEL BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 114 PM CST TUE DEC 22 2015
LIFR CONDITIONS IN HEAVY SNOW CONTINUING AT KMOT THROUGH THE
AFTERNOON...IFR CONDITIONS THEREAFTER IN SNOW THROUGH THE NIGHT.
IFR CONDITIONS EXPECTED AT KBIS THIS AFTERNOON IN LIGHT SNOW. IFR
IN LIGHT SNOW DEVELOPING AT KISN LATE THIS AFTERNOON THROUGH
TONIGHT. MVFR TO IFR CONDITIONS IN STRATUS AT KDIK AND KISN.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 6 AM CST WEDNESDAY FOR NDZ004-005-012-
013.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ022-
023-025.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...CJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
939 AM CST TUE DEC 22 2015
.UPDATE...
ISSUED AT 929 AM CST TUE DEC 22 2015
WEBCAM TRENDS THROUGH 1520 UTC INDICATE THAT THE 700-900 MB DRY
LAYER HAS NOT YET BEEN SUFFICIENTLY ERODED ACROSS CENTRAL NORTH
DAKOTA FOR SNOWFALL TO REACH THE SURFACE. 15 UTC RAP SOUNDINGS
SUGGESTS THE LAYER WILL QUICKLY SATURATE IN THE 16-17 UTC
TIMEFRAME. OVERALL...THE 12 UTC WRF-NMM/ARW...NAM NEST AND 11-14
UTC HRRR ITERATIONS SUPPORT THE TREND FROM THE 00 AND 06 UTC
GLOBAL SUITES OF A SLIGHT NORTHWARD SHIFT IN THE SNOWBAND TODAY AS
COMPARED TO RUNS YESTERDAY...WITH NOW LESS THAN ONE INCH OF SNOW
EXPECTED FOR BISMARCK/MANDAN.
UPDATE ISSUED AT 646 AM CST TUE DEC 22 2015
NO SIGNIFICANT CHANGES WITH THIS UPDATE OTHER THAN TO BLEND THE
LATEST RADAR TRENDS INTO THE HOURLY POP FORECAST THROUGH 15 UTC.
RADAR ECHOES HAVE BEEN STEADILY INCREASING OVER SOUTH CENTRAL ND
DURING THE LAST 90 MINUTES...AND WHILE NO PRECIPITATION REPORTS
HAVE BEEN RECEIVED YET...THE 12 UTC BISMARCK SOUNDING IS NEARLY
SATURATED ALOFT...SO SNOW SHOULD QUICKLY DEVELOP BY MID MORNING.
NOTE THAT OVERNIGHT RAP AND HRRR SIMULATIONS /INCLUDING THE ESRL
HRRR/ HAVE BEEN INCONSISTENT FROM RUN TO RUN AND WITH THE GLOBAL
MODEL GUIDANCE...ESPECIALLY ON THE WESTERN AND SOUTHERN BOUNDARY
OF EXPECTED SNOWFALL TODAY...SO THE ACCUMULATION FORECAST STAYED
THE SAME WITH THIS UPDATE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST TUE DEC 22 2015
ACCUMULATING SNOW IS THE MAIN CONCERN IN THE SHORT TERM.
CURRENTLY...THE SURFACE LOW WAS AT THE BORDER OF SOUTHEASTERN
MONTANA AND NORTHEASTERN WYOMING. STRONG SOUTHWESTERLY SURFACE
WINDS WERE NOTED OVER EASTERN WYOMING AND FAR WESTERN SOUTH
DAKOTA. THESE SURFACE WINDS WERE INDICATIVE OF A STRONG LOW LEVEL
JET DEPICTED IN THE MODELS AT H925 AND H850. AT UPPER LEVELS...A
STRONG SHORTWAVE WAS CENTERED OVER WYOMING. LIGHT RADAR RETURNS
WERE OVER EASTERN MONTANA INTO NORTHEASTERN WYOMING...BUT
INTENSITIES WERE INCREASING SOUTH AND EAST OF BILLINGS INTO
NORTHEASTERN WYOMING...IN THE VICINITY OF THE UPPER LEVEL
SHORTWAVE.
THE UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE NORTHEAST ACROSS THE
DAKOTAS TODAY AND MOVE INTO SOUTHERN MANITOBA TONIGHT. THE SURFACE
AND H700 LOW ARE FORECAST TO TRACK NORTHEASTWARD ACROSS NORTH DAKOTA
TODAY...REACHING THE ND/MN/MANITOBA BORDER BY MIDNIGHT TUESDAY
NIGHT. STRONG FRONTOGENETIC FORCING WITH VERTICAL MOTION IN THE
DENDRITIC GROWTH ZONE ARE EXPECTED ALONG THIS TRACK. THE MODELS
INDICATE A DEEPER DENDRITIC GROWTH ZONE LATE THIS MORNING/AFTERNOON
IN NORTH CENTRAL NORTH DAKOTA. FARTHER SOUTH THE TEMPERATURE
PROFILES ARE WARMER EARLY ON THIS MORNING WHEN THE BEST VERTICAL
MOTION IS FORECAST. SO THE LATEST RUN OF THE MODELS VALIDATE THE
ONGOING FORECAST OF MORE PRECIPITATION/SNOWFALL NORTH CENTRAL VERSUS
ACROSS THE SOUTH. THE WARM AIR LAYER OFF THE SURFACE ASSOCIATED WITH
THE LOW LEVEL JET WILL BRING A CHANCE OF MIXED PRECIPITATION TO
PARTS OF SOUTHERN NORTH DAKOTA TODAY...AND THIS WILL LIMIT THE
AMOUNT OF SNOW EXPECTED IN THE SOUTHERN TIER OF COUNTIES.
THE LATEST SHORT TERM HIGH RESOLUTION MODELS ARE NOT AS ROBUST WITH
PRECIP OUTPUT AS THE GLOBAL MODELS...AND USED A BLEND OF HIGH RES
AND GLOBAL MODEL SNOW RATIO METHODS. SNOW IS EXPECTED TO BEGIN OVER
SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA AROUND 6 AM CST...AND
INCREASE QUICKLY BY AROUND 9 AM CST. THE GREATEST FORCING MOVES INTO
NORTHERN NORTH DAKOTA AROUND/AFTER 9 AM CST AND THE AFTERNOON HOURS
SHOULD SEE THE MOST SNOW ACCUMULATIONS ACROSS THE NORTH. THE
SOUTHWEST AND SOUTH CENTRAL SHOULD SEE UP TO AN INCH OR 2 OF SNOW BY
TONIGHT...WITH THE GREATEST SNOWFALL OF 3 TO OVER 5 INCHES OF SNOW
IN THE NORTH CENTRAL...WITH THE HIGHER AMOUNTS IN THE TURTLE
MOUNTAINS AREA.
WILL ADD BOTTINEAU COUNTY TO THE ONGOING WINTER WEATHER
ADVISORY...WHICH WILL INCLUDE WESTHOPE AND BOTTINEAU...VELVA AND
TOWNER...AND POINTS EAST TO RUGBY AND THE TURTLE MOUNTAINS. THERE
MAY BE A COUPLE LOCALES THAT REACH 6 INCHES OR A BIT MORE...BUT IN
GENERAL 3 TO 5.5 INCHES OF SNOW IS EXPECTED MOST AREAS IN THE
ADVISORY.
SNOW SHOULD TAPER TO LIGHT SNOW OR FLURRIES AS THE SYSTEM MOVES
NORTHEAST...BUT LINGER THROUGH THE NIGHT TUESDAY NIGHT AS A WEAK
TROWAL FEATURE KEEPS THE WRAP AROUND PRECIPITATION AS FAR WEST AS
MONTANA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM CST TUE DEC 22 2015
COOL AND GENERALLY QUIET WEATHER WILL PREVAIL IN THE LONG TERM.
FLURRIES OR LIGHT SNOW SHOWERS REMAIN POSSIBLE ON WEDNESDAY WITH
LINGERING CYCLONIC FLOW ACROSS THE REGION. ON THE LARGE SCALE...A
BROAD AND LOW-AMPLITUDE 500-MB TROUGH OVER THE WESTERN AND CENTRAL
UNITED STATES WILL BE REPLACED BY A MUCH DEEPER AND DYNAMICALLY-
ENERGIZED TROUGH CENTERED ON THE FOUR-CORNERS REGION BY SATURDAY.
THAT TRANSITION COULD YIELD LIGHT SNOW IN THE NORTHERN PLAINS LATE
ON CHRISTMAS DAY OR MORE SO ON FRIDAY NIGHT AS FLOW ALOFT BECOMES
SOUTHWESTERLY. HOWEVER...CONFIDENCE IN THE NORTHERN EXTENT OF ANY
LIGHT SNOW IS MODEST AT BEST AS SPLIT FLOW TAKES SHAPE ALOFT...AS
EXEMPLIFIED BY THE 00 UTC ECMWF...WHICH WAS A DRY SOLUTION ACROSS
MUCH OF WESTERN AND CENTRAL ND DURING THAT TIME FRAME.
TEMPERATURES WILL BE SEASONABLY COOL MOST OF THE PERIOD...AND WILL
BE COLDEST FRIDAY INTO SATURDAY...WHEN LOWS WILL BE AROUND 0 F AND
HIGHS WILL ONLY BE IN THE TEENS F PER A 00 UTC MULTI-MODEL BLEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 929 AM CST TUE DEC 22 2015
IFR/LIFR CONDITIONS IN SNOW AT KMOT/KJMS DEVELOPING THIS
MORNING...CONTINUING THROUGH THE EARLY AFTERNOON AT KJMS AND
POSSIBLY INTO THE EVENING AT KMOT. IFR CONDITIONS IN LIGHT SNOW
POSSIBLE BY MIDDAY AT KISN WITH A BRIEF LATE AFTERNOON BREAK
POSSIBLE BEFORE ADDITIONAL LIGHT SNOW THIS EVENING AND TONIGHT.
MVFR/IFR CONDITIONS IS STRATUS AT KBIS/KDIK TODAY AND TONIGHT WITH
MUCH LOWER PROBABILITIES FOR SNOW COMPARED TO THE OTHER
TERMINALS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ004-
005-012-013-022-023-025.
&&
$$
UPDATE...AYD
SHORT TERM...JV
LONG TERM...CJS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
646 AM CST TUE DEC 22 2015
.UPDATE...
ISSUED AT 646 AM CST TUE DEC 22 2015
NO SIGNIFICANT CHANGES WITH THIS UPDATE OTHER THAN TO BLEND THE
LATEST RADAR TRENDS INTO THE HOURLY POP FORECAST THROUGH 15 UTC.
RADAR ECHOES HAVE BEEN STEADILY INCREASING OVER SOUTH CENTRAL ND
DURING THE LAST 90 MINUTES...AND WHILE NO PRECIPITATION REPORTS
HAVE BEEN RECEIVED YET...THE 12 UTC BISMARCK SOUNDING IS NEARLY
SATURATED ALOFT...SO SNOW SHOULD QUICKLY DEVELOP BY MID MORNING.
NOTE THAT OVERNIGHT RAP AND HRRR SIMULATIONS /INCLUDING THE ESRL
HRRR/ HAVE BEEN INCONSISTENT FROM RUN TO RUN AND WITH THE GLOBAL
MODEL GUIDANCE...ESPECIALLY ON THE WESTERN AND SOUTHERN BOUNDARY
OF EXPECTED SNOWFALL TODAY...SO THE ACCUMULATION FORECAST STAYED
THE SAME WITH THIS UPDATE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST TUE DEC 22 2015
ACCUMULATING SNOW IS THE MAIN CONCERN IN THE SHORT TERM.
CURRENTLY...THE SURFACE LOW WAS AT THE BORDER OF SOUTHEASTERN
MONTANA AND NORTHEASTERN WYOMING. STRONG SOUTHWESTERLY SURFACE
WINDS WERE NOTED OVER EASTERN WYOMING AND FAR WESTERN SOUTH
DAKOTA. THESE SURFACE WINDS WERE INDICATIVE OF A STRONG LOW LEVEL
JET DEPICTED IN THE MODELS AT H925 AND H850. AT UPPER LEVELS...A
STRONG SHORTWAVE WAS CENTERED OVER WYOMING. LIGHT RADAR RETURNS
WERE OVER EASTERN MONTANA INTO NORTHEASTERN WYOMING...BUT
INTENSITIES WERE INCREASING SOUTH AND EAST OF BILLINGS INTO
NORTHEASTERN WYOMING...IN THE VICINITY OF THE UPPER LEVEL
SHORTWAVE.
THE UPPER LEVEL SHORTWAVE IS FORECAST TO MOVE NORTHEAST ACROSS THE
DAKOTAS TODAY AND MOVE INTO SOUTHERN MANITOBA TONIGHT. THE SURFACE
AND H700 LOW ARE FORECAST TO TRACK NORTHEASTWARD ACROSS NORTH DAKOTA
TODAY...REACHING THE ND/MN/MANITOBA BORDER BY MIDNIGHT TUESDAY
NIGHT. STRONG FRONTOGENETIC FORCING WITH VERTICAL MOTION IN THE
DENDRITIC GROWTH ZONE ARE EXPECTED ALONG THIS TRACK. THE MODELS
INDICATE A DEEPER DENDRITIC GROWTH ZONE LATE THIS MORNING/AFTERNOON
IN NORTH CENTRAL NORTH DAKOTA. FARTHER SOUTH THE TEMPERATURE
PROFILES ARE WARMER EARLY ON THIS MORNING WHEN THE BEST VERTICAL
MOTION IS FORECAST. SO THE LATEST RUN OF THE MODELS VALIDATE THE
ONGOING FORECAST OF MORE PRECIPITATION/SNOWFALL NORTH CENTRAL VERSUS
ACROSS THE SOUTH. THE WARM AIR LAYER OFF THE SURFACE ASSOCIATED WITH
THE LOW LEVEL JET WILL BRING A CHANCE OF MIXED PRECIPITATION TO
PARTS OF SOUTHERN NORTH DAKOTA TODAY...AND THIS WILL LIMIT THE
AMOUNT OF SNOW EXPECTED IN THE SOUTHERN TIER OF COUNTIES.
THE LATEST SHORT TERM HIGH RESOLUTION MODELS ARE NOT AS ROBUST WITH
PRECIP OUTPUT AS THE GLOBAL MODELS...AND USED A BLEND OF HIGH RES
AND GLOBAL MODEL SNOW RATIO METHODS. SNOW IS EXPECTED TO BEGIN OVER
SOUTHWEST AND SOUTH CENTRAL NORTH DAKOTA AROUND 6 AM CST...AND
INCREASE QUICKLY BY AROUND 9 AM CST. THE GREATEST FORCING MOVES INTO
NORTHERN NORTH DAKOTA AROUND/AFTER 9 AM CST AND THE AFTERNOON HOURS
SHOULD SEE THE MOST SNOW ACCUMULATIONS ACROSS THE NORTH. THE
SOUTHWEST AND SOUTH CENTRAL SHOULD SEE UP TO AN INCH OR 2 OF SNOW BY
TONIGHT...WITH THE GREATEST SNOWFALL OF 3 TO OVER 5 INCHES OF SNOW
IN THE NORTH CENTRAL...WITH THE HIGHER AMOUNTS IN THE TURTLE
MOUNTAINS AREA.
WILL ADD BOTTINEAU COUNTY TO THE ONGOING WINTER WEATHER
ADVISORY...WHICH WILL INCLUDE WESTHOPE AND BOTTINEAU...VELVA AND
TOWNER...AND POINTS EAST TO RUGBY AND THE TURTLE MOUNTAINS. THERE
MAY BE A COUPLE LOCALES THAT REACH 6 INCHES OR A BIT MORE...BUT IN
GENERAL 3 TO 5.5 INCHES OF SNOW IS EXPECTED MOST AREAS IN THE
ADVISORY.
SNOW SHOULD TAPER TO LIGHT SNOW OR FLURRIES AS THE SYSTEM MOVES
NORTHEAST...BUT LINGER THROUGH THE NIGHT TUESDAY NIGHT AS A WEAK
TROWAL FEATURE KEEPS THE WRAP AROUND PRECIPITATION AS FAR WEST AS
MONTANA.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM CST TUE DEC 22 2015
COOL AND GENERALLY QUIET WEATHER WILL PREVAIL IN THE LONG TERM.
FLURRIES OR LIGHT SNOW SHOWERS REMAIN POSSIBLE ON WEDNESDAY WITH
LINGERING CYCLONIC FLOW ACROSS THE REGION. ON THE LARGE SCALE...A
BROAD AND LOW-AMPLITUDE 500-MB TROUGH OVER THE WESTERN AND CENTRAL
UNITED STATES WILL BE REPLACED BY A MUCH DEEPER AND DYNAMICALLY-
ENERGIZED TROUGH CENTERED ON THE FOUR-CORNERS REGION BY SATURDAY.
THAT TRANSITION COULD YIELD LIGHT SNOW IN THE NORTHERN PLAINS LATE
ON CHRISTMAS DAY OR MORESO ON FRIDAY NIGHT AS FLOW ALOFT BECOMES
SOUTHWESTERLY. HOWEVER...CONFIDENCE IN THE NORTHERN EXTENT OF ANY
LIGHT SNOW IS MODEST AT BEST AS SPLIT FLOW TAKES SHAPE ALOFT...AS
EXEMPLIFIED BY THE 00 UTC ECMWF...WHICH WAS A DRY SOLUTION ACROSS
MUCH OF WESTERN AND CENTRAL ND DURING THAT TIME FRAME.
TEMPERATURES WILL BE SEASONABLY COOL MOST OF THE PERIOD...AND WILL
BE COLDEST FRIDAY INTO SATURDAY...WHEN LOWS WILL BE AROUND 0 F AND
HIGHS WILL ONLY BE IN THE TEENS F PER A 00 UTC MULTI-MODEL BLEND.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 638 AM CST TUE DEC 22 2015
AREAS OF MVFR-IFR STRATUS EXPECTED IN CENTRAL NORTH DAKOTA EARLY
THIS MORNING AT KJMS. VFR CONDITIONS WEST AT KISN/KMOT/KDIK/BIS
EARLY...THEN INCREASING CLOUDS WITH AN APPROACHING SMALL BUT POTENT
LOW PRESSURE SYSTEM. THIS SYSTEM WILL BRING MVFR-IFR CEILINGS AND
VISIBILITIES IN SNOW AND FOG FROM MAINLY KDIK AND KBIS AROUND 12Z TO
KMOT AND KJMS BEGINNING AROUND 15Z. THE SYSTEM WILL EXIT SLOWLY TO
THE NORTHEAST TUESDAY EVENING...BUT THE POTENTIAL FOR LOW STRATUS
AND FOG WILL REMAIN AT TAF SITES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR NDZ004-
005-012-013-022-023-025.
&&
$$
UPDATE...CJS
SHORT TERM...JV
LONG TERM...CJS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1233 AM CST TUE DEC 22 2015
.UPDATE...
ISSUED AT 1233 AM CST TUE DEC 22 2015
NO SIGNIFICANT CHANGES THIS UPDATE FOR THE OVERNIGHT HOURS. THE
SMALL AREA OF DENSE FOG IN THE SOUTH CENTRAL HAS SEEN IMPROVING
VISIBILITIES...LIKELY DUE TO THE HIGHER CLOUDS AND INCREASING WINDS
ASSOCIATED WITH THE APPROACHING SYSTEM FROM THE SOUTHWEST. ISSUED A
SPECIAL WEATHER STATEMENT TO ADDRESS A SMALL AREA OF DENSE FOG IN
THE NORTH CENTRAL NEAR RUGBY/TURTLE MOUNTAINS - ON THE WESTERN EDGE
OF THE LOW STRATUS CLOUDS. THIS AREA SHOULD SEE IMPROVING
VISIBILITIES AS THE HIGH CLOUDS AND INCREASING WINDS REACH THAT AREA
IN THE NEXT COUPLE OF HOURS.
STILL EXPECT SNOW TO DEVELOP QUICKLY JUST BEFORE OR AROUND DAYBREAK
IN THE SOUTHWEST AND SOUTH CENTRAL...EXPANDING QUICKLY NORTH AND
EAST DURING THE MORNING. THE WINTER WEATHER ADVISORY FOR THE NORTH
CENTRAL MAY NEED TO BE EXPANDED WESTWARD AND SOUTHWESTWARD BY A
COUNTY OR SO...BUT REMAINING IN THE NORTH CENTRAL.
UPDATE ISSUED AT 951 PM CST MON DEC 21 2015
NO SIGNIFICANT UPDATES FOR THE LATE EVENING FORECAST. ISSUED A SPS
FOR FOG ALONG THE WESTERN EDGE OF STRATUS ACROSS SOUTH CENTRAL
NORTH DAKOTA. THIS IS MAINLY ALONG THE MISSOURI RIVER FROM THE
SOUTH DAKOTA BORDER TO LAKE SAKAKAWEA. SINCE THE ISSUANCE SOME OF
THE ASOS/AWOS OBSERVATIONS HAVE IMPROVED A LITTLE AS WARM
ADVECTION AND CLOUDS CONTINUE TO INCREASE FROM WEST TO EAST. WILL
CONTINUE TO MONITOR BUT FOR NOW WILL CONTINUE WITH AN SPS AND NOT
ISSUE A DENSE FOG ADVISORY.
TEMPERATURES CONTINUE TO BE AN ISSUE WITH SOME CLEAR SPOTS...BUT
AS STRATUS SPREADS NORTH AND MID-HIGH CLOUDS INCREASE FROM THE
WEST...WE SHOULD SEE TEMPERATURES STEADY...AND MAYBE RISE A BIT.
AS FAR AS SNOWFALL...HAVE DELAYED THE ARRIVAL OF PRECIPITATION BY
A COUPLE HOURS. LATEST ITERATIONS OF THE MESOSCALE MODELS ARE
ACTUALLY PRETTY SIMILAR TO THE PREVIOUS FORECAST...WITH THE SLIGHT
DELAY IN ONSET. NO SIGNIFICANT CHANGES TO THE OVERALL SNOW
FORECAST AS MODELS ARE JUST ROLLING IN...BUT SEE NOTHING AT THIS
TIME INDICATING A SIGNIFICANT CHANGE FROM OUR CURRENT ADVISORY.
UPDATE ISSUED AT 645 PM CST MON DEC 21 2015
MAIN FORECAST PROBLEM FOR THIS EVENING WILL ONCE AGAIN BE
TEMPERATURES AND CLOUDS/FOG.
CURRENTLY...MAINLY CLEAR SKIES ACROSS WESTERN NORTH DAKOTA.
WIDESPREAD STRATUS OVER THE SOUTH CENTRAL FROM AROUND BISMARCK AND
FORT YATES EAST TO THE JAMES RIVER VALLEY...EXCEPT FOR A HOLE THAT
INCLUDES THE KJMS TAF. STRATUS HAS LIFTED ACROSS MOST OF THE NORTH
CENTRAL BUT A FEW PATCHES REMAIN AROUND THE TURTLE MOUNTAINS.
THINK THESE AREAS ACROSS CENTRAL NORTH DAKOTA WILL LIKELY FILL IN
THIS EVENING. ACROSS THE WEST SKIES MAY REMAIN CLEAR UNTIL HIGHER
CLOUDS ASSOCIATED WITH THE NEXT SYSTEM APPROACH BY MID TO LATE
EVENING. THIS WOULD ALLOW TEMPERATURES TO FALL A LITTLE MORE THAN
ORIGINALLY FORECAST. WILL ADJUST SKY BASED ON LATEST SATELLITE
ANALYSIS AND EXPECTATION FROM MESOSCALE MODELS THAT CENTRAL ND
WILL LIKELY CLOUD UP AGAIN WITH STRATUS DURING THE EVENING. WILL
NEED TO LOWER TEMPERATURES A BIT IN THE FAR EAST WHERE
TEMPERATURES ARE ALREADY NEAR FORECAST LOWS...BUT WITH STRATUS IN
PLACE MANY AREAS...WON`T LET THEM DROP TOO MUCH. WILL LIKELY LOWER
TEMPERATURES A LITTLE IN THE WEST AS EVEN THOUGH WARM ADVECTION
AND CLOUDS WILL INCREASE LATER...SHOULD BE A FEW HOURS WITH CLEAR
SKIES AND LIGHT WINDS BEFORE THIS BEGINS IN EARNEST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 215 PM CST MON DEC 21 2015
FOG TONIGHT AND ACCUMULATING SNOW TUESDAY HIGHLIGHT THE SHORT TERM
FORECAST.
THE 15-19 UTC HRRR ITERATIONS AND THE 12 UTC NAM NEST ONCE AGAIN
TONIGHT DEPICT FOG DEVELOPMENT WITHIN THEIR RESPECTIVE VISIBILITY
FIELDS. THESE FORECASTS HAVE PERFORMED WELL THE PAST WEEK IN
SIGNALING FOG...AND WILL FOLLOW THEIR SOLUTIONS WHICH SUGGEST FOG
GENERALLY ALONG AND EAST OF HIGHWAY 83 TONIGHT INTO EARLY TUESDAY
MORNING BEFORE THE SNOWFALL. A DENSE FOG ADVISORY MAY BE
POSSIBLE.
FOR TUESDAY...THE 12 UTC AND INCOMING 18 UTC DETERMINISTIC AND
ENSEMBLE SUITES ARE IN AGREEMENT ON A WAVE EJECTING NORTHEAST OUT
OF WYOMING...DEEPENING AND POTENTIALLY CLOSING OFF AS IT
PROPAGATES ACROSS NORTH DAKOTA. STRONG FRONTOGENETIC FORCING AND
VERTICAL MOTION IN THE DENDRITIC GROWTH LAYER ARE EXPECTED ALONG
AND NORTH OF THE 700 MB LOW TRACK FROM SOUTHWEST THROUGH NORTHEAST
NORTH DAKOTA TO SUPPORT MESOSCALE BANDING OF SNOW. THE GREATEST
SNOWFALL AMOUNTS OF 3 TO 5 INCHES ARE FORECAST ACROSS THE FAR
NORTH CENTRAL AND TURTLE MOUNTAINS WHERE SNOWFALL DURATION WILL BE
THE LONGEST IN ASSOCIATION WITH THE DEVELOPING TROWAL. THUS...HAVE
ISSUED A WINTER WEATHER ADVISORY FOR THESE AREAS. FOR NOW...THE
LACK OF STRONG ELEVATED INSTABILITY IS EXPECTED TO KEEP SNOWFALL
AMOUNTS BELOW WARNING LEVELS. HOWEVER...THIS WILL HAVE TO BE
CLOSELY MONITORED IN THE MODEL SOLUTIONS OVER THE NEXT 12 HOURS.
ELSEWHERE...WIDESPREAD ONE TO THREE INCH SNOWFALL AMOUNTS ARE
EXPECTED.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 215 PM CST MON DEC 21 2015
SURFACE LOW AND ASSOCIATED MID/UPPER LEVEL TROUGH WILL EXIT THE
TURTLE MOUNTAINS AND SHIFT INTO SOUTHERN ONTARIO BY 12Z WEDNESDAY.
SNOW WILL GRADUALLY DIMINISH AND END TUESDAY NIGHT WITH A COLD
POCKET/THERMAL TROUGH LINGERING THROUGH WEDNESDAY. THIS WILL RESULT
IN PLENTY OF CLOUDS AND POSSIBLE FLURRIES WEDNESDAY. ANOTHER WEAK
SHORTWAVE IS EXPECTED THURSDAY AFTERNOON/EVENING...BUT ANY
PRECIPITATION THREAT IS VERY MINIMAL. A SPLIT FLOW DEVELOPS FOR
THE REST OF THE EXTENDED PERIOD AS AN UPPER TROUGH/LOW IS CARVED
OUT IN THE SOUTHWEST. NORTH DAKOTA FALLS UNDER A SOUTHWEST FLOW
ALOFT CHRISTMAS DAY/FRIDAY...WITH A DEFORMATION ZONE EVOLVING
ACROSS SOUTHERN NORTH DAKOTA FRIDAY NIGHT INTO SATURDAY MORNING.
CHRISTMAS DAY REMAINS DRY WITH MOISTURE ADVECTION INCREASING
FRIDAY EVENING FAR SOUTH. THIS IS IN RESPONSE TO AN INITIAL
MID/UPPER LEVEL LOW EJECTING FROM THE SOUTHWEST UPPER TROUGH WILL
SLIDE ACROSS SOUTH DAKOTA DURING THE ABOVE TIME. WILL CONTINUE TO
WATCH THE TRACK BUT AS OF NOW SOME LIGHT SNOW IS EXPECTED SOUTH OF
I-94 DURING THIS TIME. THIS SHORTWAVE DEPARTS SATURDAY NIGHT WITH
DRY WEATHER UNTIL AT LEAST MONDAY. HIGHS WILL REMAINING IN THE 20S
WED/THU...THEN COLDER AIR WILL BE DRAWN INTO THE APPROACHING
SOUTHWEST SYSTEM WITH WINDS BECOMING NORTH TO NORTHEAST FRI/SAT.
AS THE SYSTEM DEPARTS AND WINDS BECOME SOUTHWEST...HIGHS WILL ONCE
AGAIN REBOUND INTO THE 20S SUNDAY AND MONDAY. OVERNIGHT LOWS WILL
BE COLDEST FRIDAY MORNING THROUGH SUNDAY MORNING WITH LOWS 5 BELOW
ZERO NORTH TO 5 ABOVE ZERO SOUTH.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1233 AM CST TUE DEC 22 2015
AREAS OF MVFR-IFR STRATUS EXPECTED IN CENTRAL NORTH DAKOTA EARLY
THIS MORNING AT KBIS/KJMS. VFR CONDITIONS WEST AT KISN/KMOT/KDIK
EARLY...THEN INCREASING CLOUDS WITH AN APPROACHING SMALL BUT POTENT
LOW PRESSURE SYSTEM. THIS SYSTEM WILL BRING MVFR-IFR CEILINGS AND
VISIBILITIES IN SNOW AND FOG FROM MAINLY KDIK AND KBIS AROUND 12Z TO
KMOT AND KJMS BEGINNING AROUND 15Z. THE SYSTEM WILL EXIT SLOWLY TO
THE NORTHEAST TUESDAY EVENING...BUT THE POTENTIAL FOR LOW STRATUS
AND FOG WILL REMAIN AT TAF SITES.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR NDZ005-012-013-022-023-025.
&&
$$
UPDATE...JV
SHORT TERM...AYD
LONG TERM...KS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
600 PM EST TUE DEC 22 2015
.SYNOPSIS...
A PARADE OF SYSTEMS IMPACTING THE FORECAST AREA THROUGH NEXT WEEK.
PERIODS OF HEAVY RAIN POSSIBLE.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
RADAR IMAGES SHOW LIGHT PCPN OR VIRGA ACROSS OUR AREA. EXPECT
THESE AREAS OF PCPN TO DISSIPATE LATER TONIGHT. ADJUSTED POPS TO
REFLECT THE LATEST RADAR AND MODEL TRENDS. REST OF FORECAST
REMAINS ON TRACK.
PREVIOUS DISCUSSION BELOW...
RAIN MOVING OUT OF THE AREA ALLOWING FOR A LITTLE SUN THIS
AFTERNOON ON THIS WARM FIRST DAY OF WINTER...BUT THE REPRIEVE FROM
PRECIPITATION WILL BE SHORT LIVED.
THE NEXT DISTURBANCE ARRIVES LATE TONIGHT INTO WED. MODELS
ENVELOPE OUR FORECAST AREA IN PRECIP...BUT MOST AGREE TO BRING THE
MOST PREVALENT QPF INTO THE AREA BETWEEN 100 AND 700 AM WEDNESDAY
MORNING. SCATTERED SHOWERS MAY LINGER THROUGH MUCH OF THE DAY
BEFORE ANOTHER WAVE ARRIVES WED NIGHT. THIS WAVE MAY PRODUCE A
THUNDERSTORM OR TWO ESPECIALLY IN THE OHIO RIVER VALLEY.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
MESSY FORECAST...WITH RELATIVELY HIGH UNCERTAINTY DUE TO MODEL
DIFFERENCES. SYNOPTICALLY...A DEEPENING SURFACE LOW WILL BE MOVING
NE THROUGH THE WESTERN GREAT LAKES WEDNESDAY NIGHT...AND WELL
NORTHWARD INTO CANADA THURSDAY. ALREADY MODEL DIFFERENCES HERE WITH
THE ECMWF AND GFS STRONGER AND SLOWER WITH THIS THAN THE NAM. THIS
WILL PUSH A COLD FRONT INTO THE MIDDLE OHIO RIVER VALLEY. MODELS
AGAIN LEND MORE UNCERTAINTY AS THE NAM AND ECMWF MOSTLY WASH THE
FRONT OUT IN THE OHIO RIVER VALLEY...WHILE THE GFS IS FASTER AND
PUSHES THE FRONT THROUGH BEFORE WASHING OUT ACROSS THE CENTRAL
APPALACHIANS. LOOKING AT THE FLOW ALOFT LENDS SOME ADDITIONAL INFO
TO THE EQUATION AS IT IS NEARLY PARALLEL TO THE FRONT. SO DO NOT
EXPECT MUCH PUSH TO THE FRONT. WITH THIS IN MIND...TRIED TO REFLECT
THE FRONT WASHING OUT OVER CWA WITH POPS DROPPING INTO CHANCE RANGE
THURSDAY NIGHT...AND THEN LIKELY POPS COMING BACK IN FROM THE SW AS
A WAVE REORGANIZES THE BOUNDARY AND STARTS PUSHING IT BACK NORTH AS
A WARM FRONT ON FRIDAY.
NAM SHOWING UP CLOSE TO 1000J/KG CAPE THURSDAY...WHILE LIKELY TOO
HIGH...IS IMPRESSIVE FOR LATE DECEMBER. SO HAVE CONTINUED THUNDER
WORDING. BEST SHEAR REMAINS NORTH AND WEST WHICH MAY LIMIT SEVERE
POTENTIAL FOR OUR CWA. HAVE ALSO ADDED MENTION IN HWO FOR POTENTIAL
HEAVY RAIN STARTING FRIDAY.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
THE UNSETTLED WX PATTERN ROLLS ON. THE OLD FRONTAL BOUNDARY WILL
BE RE ENERGIZED BY FRIDAY NIGHT AS INFLUX OF GULF MOISTURE
ADVECTS IN ON THE W PERIPHERAL OF THE UPPER RIDGE...AIDED BY
VARIOUS UPPER AIR IMPULSES. THIS PLACES PORTIONS OF THE CWA IN THE
ZONE FOR SOME MODERATE TO PERHAPS LOCALIZED HEAVY RAINFALL. THIS
AXIS OF HEAVY RAIN WILL GRADUALLY SHIFT N SATURDAY AS THE WARM
FRONT LIFTS N. ATTM IT APPEARS SE OH MAY SEE THE HIGHEST QPF
AMOUNTS...ON THE ORDER OF 1 TO LOLLIPOP 2 INCH AMOUNTS AMOUNTS
AROUND AN INCH ARE POSSIBLE ELSEWHERE. WE HAVE INSERTED A MENTION
OF POTENTIAL WATER PROBLEMS IN THE HWO PRODUCT HIGHLIGHTING SE OH
ZONES.
ONCE THE WARM FRONT LIFTS N OUT OF THE AREA ON SATURDAY...TEMPS
SHOULD RISE ACCORDINGLY. DEPENDING ON CLOUD COVER AND TIMING OF
EXODUS OF WARM FRONT...MUCH OF THE CWA MAY EXPERIENCE RECORD
BREAKING HIGH TEMPERATURES. BOTH THE MOS GUIDANCE FROM GFS/ECWMF
SUGGESTS MID TO UPPER 70S FOR PORTIONS OF THE
LOWLANDS...PARTICULARLY ALONG AND S OF I64 CORRIDOR. NOT GOING TO
BITE ON THAT JUST YET GIVEN UNCERTAINTY WITH EXTENT OF CLOUDS.
HOWEVER...DID RAISE MAXT INTO THE 72 TO 75F RANGE. SHOULD MORE SUN
BE REALIZED THEN THOSE UPPER 70S WOULD CERTAINLY BE REACHABLE.
STATUS QUO SATURDAY NIGHT AS THE UPPER RIDGE FLEXES ITS MUSCLE
INTO THE REGION AND A SIGNIFICANT PIECE OF ENERGY DROPS DOWN INTO
THE S PLAINS. HOWEVER THE OLD FRONTAL BOUNDARY WONT BE TOO FAR OFF
TO THE NW. OVERNIGHT LOWS WILL CONTINUE TO RUN WELL ABOVE NORMAL
JUST AS THE DAYTIME HIGHS DO.
SUNDAY WILL FEATURE THE UPPER TROF AXIS TO THE N TRY TO BEAT DOWN
THE RIDGE A BIT TO ALLOW THE FRONT TO SLIP BACK S INTO THE AREA.
HOWEVER...WITH SURFACE CYCLOGENESIS OVER TX AND MOST OF THE
DYNAMICS FOCUSED OVER THAT REGION...NOT EXPECTING WIDESPREAD
RAINFALL. AS SUCH...LOOK FOR HIGHS TO COME DOWN A BIT BUT STILL 20
TO 25 DEGREES ABOVE NORMAL.
UPPER LEVEL HEIGHTS BUILD ONCE AGAIN ON MONDAY AHEAD OF
AFOREMENTIONED SYSTEM TRACKING INTO THE UPPER MS VALLEY. WILL KEEP
POPS LOW UNTIL MONDAY NIGHT WHEN THE ASSOCIATED COLD FRONT
APPROACHES.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
VFR CONDITIONS WILL PREVAIL THROUGH EARLY WEDNESDAY. SATELLITE
IMAGES AND SFC OBS INDICATE PLENTY OF HIGH LEVEL CLOUDS OVER THE
AREA TONIGHT. LOW STRATUS COULD DEVELOP OVER AREAS THAT RECEIVED
RAIN. HOWEVER...NOT EXPECTING DENSE FOG FORMATION AS THE
BOUNDARY LAYER WINDS WILL BE 15 TO 20 KNOTS ACCORDING TO THE NAM
AND RAP MODELS. THE LOWER ATMOSPHERE SHOULD DECOUPLE TONIGHT
PRODUCING LIGHT AND VARIABLE WINDS OR CALM WINDS THROUGH THE EARLY
MORNING HOURS.
ANOTHER UPPER AIR DISTURBANCE BRINGS ANOTHER ROUND OF RAIN FOR
LATE TONIGHT INTO WEDNESDAY WHERE SOME IFR IS POSSIBLE
PARTICULARLY IN THE MTNS.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 00Z THURSDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: FLIGHT CATEGORIES MAY BE LOWER IN RAIN THAN
FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 22 23 00 01 02 03 04 05 06 07 08 09
EST 1HRLY 17 18 19 20 21 22 23 00 01 02 03 04
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H M M M M M M M
BKW CONSISTENCY M M M M H H H M M M M L
EKN CONSISTENCY M H H H H H H H H H M M
PKB CONSISTENCY H H H H H H H H M M M H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 00Z THURSDAY...
IFR CONDITIONS ARE LIKELY WEDNESDAY NIGHT THROUGH THURSDAY WITH
LOW CEILINGS AND RAIN.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...MZ/30/JW
NEAR TERM...ARJ/JW
SHORT TERM...MZ
LONG TERM...30
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1028 PM EST WED DEC 23 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE EAST COAST FOR
THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO PA
THROUGH SATURDAY AND AGAIN EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
900 PM UPDATE...
RAIN GONE TO THE EAST AND A LULL IS EXPECTED THROUGH MUCH OF THE
NIGHT UNTIL THE LEFTOVERS FROM THE CONVECTION TO THE WEST ARRIVES.
THE WARM AIR CONTINUES TO STRUGGLE TRYING TO GET TO THE NORTH.
HRRR AND RAP MAKE SOME VERY LIGHT SHOWERS IN THE CENTRAL MTNS
OVERNIGHT...BUT A VERY LOW CHC POP IS ALL THAT IS NECESSARY DUE
TO THE EXPECTED MINISCULE COVERAGE. THE TIMING OF THE STUFF FROM
THE WEST CONTINUES TO BE CLOSER TO MORNING THAN MIDNIGHT. FOG NOT
GETTING THICK BUT WILL CONTINUE TO MENTION PATCHY FOG THRU THE
NIGHT - MAINLY FOR THE RIDGES.
600 PM UPDATE...
RADAR RETURNS DIMINISHING ACROSS THE EAST AS SHORTWAVE AND WEAK
JET MAX SLIDE TO THE E/NE. CLUSTER OF SHRA WITH ONE LTG STRIKE IN
CENT MD LOOKS LIKE IT SHOULD MISS US TO THE SE. SOME BREAKS IN THE
CLOUD COVER NOW OVER WRN PA AND THIS COULD LEAD TO FOG AGAIN
TONIGHT...BUT NOT SIMILAR TO LAST NIGHT. LOW CLOUDS IN PLACE WILL
INITIALLY INSULATE THE AREA AND SOME GRADIENT WIND IS FOUND...ESP
IN THE NW HALF OF THE AREA. BUT ANY CLEARING WILL HELP IT TO
RADIATE WELL - SO AT LEAST PATCHY FOG IS STILL EXPECTED.
PREV...
HIGH LIKELIES AND CATEG POPS CONTINUE THROUGH LATE AFTERNOON AND
EARLY EVENING ACROSS CENTRAL PA AS WARM FRONT LIFTS NORTH OF THE
REGION BY 00Z. REGIONAL RADAR MOSAIC SHOWS ALL BUT THE NORTHWEST
MOUNTAINS WITH WIDESPREAD COVERAGE OF RAIN PRESENTLY...WITH
EMBEDDED MODERATE SHOWERS ACCOMPANYING A NARROW 850 MB JETLET OF
45-50 KTS AS IT LIFTS TOWARDS SRN NY STATE AT MID AFTERNOON.
DESPITE THE CLOUDS AND RAIN...IT IS UNREASONABLY (AND
UNSEASONABLY) MILD ACROSS CENTRAL PA WITH SOME OF MY SOUTHEAST
COUNTIES DUMBFOUNDINGLY APPROACHING 60F IN STEADY RAIN AND
SOUTHEAST LLVL FLOW.
POPS WILL STEADILY DROP OFF FROM WEST TO EAST THIS EVENING AS
BOUNDARY LAYER CONVERGENCE AND UPPER FORCING LARGELY LIFT INTO NY
STATE. FOCUS WILL SHIFT TO THE WEST AT THE SAME TIME HOWEVER AS
COLD FRONT SLOWLY APPROACHES LATE TONIGHT AND THURSDAY
MORNING...WITH INCREASING BOUNDARY LAYER CONVERGENCE AND PERHAPS
SOME ISOLATED THUNDER CROSSING THE OH/PA BORDER. IT`S NOT
INCONCEIVABLE THAT A STRIKE OR TWO COULD SURVIVE INTO THE WEST
CENTRAL MOUNTAINS BY EARLY THU MORNING...BUT FOR NOW AM FOCUSING
ON THE TIME OF MAX HEATING EAST OF THE FRONT FOR T POTENTIAL (MORE
BELOW).
TIGHTENING GRADIENT BTWN BERMUDA HIGH AND INTENSIFYING LOW OVR
THE GRT LKS WILL PRODUCE A BREEZY AND UNSEASONABLY WARM NIGHT WITH
TEMPS STEADY OR SLOWLY RISING TO THE L60S IN MANY SPOTS BY DAWN
THURSDAY. BUFKIT SOUNDINGS INDICATE SOUTHERLY WIND GUSTS OF
25-30KTS ARE POSSIBLE LATE TONIGHT ACROSS THE THE ALLEGHENY
PLATEAU...AS WELL AS THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /8 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
COLD FRONT APPROACHING IN BROAD SOUTHWEST FLOW WILL SAG
SOUTHEASTWARD THROUGHOUT THE DAY ON CHRISTMAS EVE. BRIEF MODERATE
SHOWERS ARE EXPECTED...AND WITH DEWPOINTS IN THE 50S AND MAX
TEMPS ANYWHERE FROM THE L60S ACROSS THE NW MTNS...TO THE L70S OVER
THE LOWER SUSQ VALLEY...MODEL SOUNDINGS WITH UP TO A FEW HUNDRED
J/KG CAPE ARE MORE THAN BELIEVABLE ACROSS THE MIDDLE TO LOWER SUSQ
RIVER VALLEY FROM LATE MORNING THROUGH MID AFTERNOON. ADDED T IN
COLLAB WITH BGM AND PHI...NOTING SPC MRGL OUTLOOK AREA OVER MY
SOUTHEAST AS WELL.
GUIDANCE STILL SUGGESTING MUCH OF THE MID TO LATE AFTERNOON WILL
TREND QUITE NICE AS DRIER AIR ARRIVES. ACROSS THE SOUTHEAST...THE
FRONT WILL LINGER THE LONGEST...AND HAVE MAINTAINED MEASURABLE
POPS THERE THROUGH LATE AFTERNOON.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A NEGATIVELY TILTED UPPER LEVEL RIDGE OVER THE EAST COAST...AND A
DEEP TROUGH MOVING THROUGH THE CENTRAL UNITED STATES WILL DOMINATE
THE WEATHER THROUGH THE WEEKEND. AS THE RIDGE MOVES EASTWARD THE
UPPER TROUGH PROPAGATES EASTWARD. A SHORT WAVE TROUGH...AND AN
ASSOCIATED FRONT WILL HAVE EXIT TO THE NORTHEAST...ALLOWING FOR DRY
WEATHER THURSDAY NIGHT INTO FRIDAY. THE BULK OF MED RANGE MDL DATA
SUPPORTS A PERIOD OF DRY WX THU NIGHT THROUGH CHRISTMAS DAY AS A WEAK
SFC HIGH BUILDS EAST FROM THE LOWER GRT LKS. THE STALLED FRONTAL
BOUNDARY SOUTH OF PA WILL LIFT NORTH CHRISTMAS NIGHT INTO SATURDAY.
A DEEPER TROUGH MOVING DOWN FROM THE PACIFIC NORTHWEST...AND THROUGH
THE WESTERN US WILL COUPLE WITH MORE ZONAL FLOW TO FORM THE
QUASI-STATIONARY BOUNDARY THAT WILL BRING PRECIPITATION THIS WEEKEND.
ALL MID TO LONG RANGE MODELS HAVE THE TROUGH FORM A CUT OFF LOW. THE
BIG QUESTION IS LOCATION. THE GEFS/GFS/EC ALL VARY IN POSITION
AND STRENGTH...THOUGH THE PREDOMINATE LOCATION IS OVER TEXAS. ALL
MODELS HAVE A MOIST BOUNDARY EXTEND FROM THE TROUGH/LOW THROUGH
NEW ENGLAND. THE FORECAST QUESTION OVER THE WEEKEND WILL THEN BE
WHEN/WHERE THE CONVEYER BELT OF MOISTURE SETS UP AND THE MOVEMENT
OF THE TROUGH/LOW AND THE ASSOCIATED BOUNDARY. THE EC HAS A DEEPER
TROUGH BUT SETS UP THE MOISTURE BELT FASTER...BRINGING THE
BOUNDARY NORTHWARD THROUGH PA FRIDAY NIGHT INTO SATURDAY. THE
GFS/GEFS BRINGS THE BEST MOISTURE SATURDAY AFTERNOON. SO DESPITE
THE VARIANCES ALL PWATS ARE ANOMALOUS IN THE +3 TO +4 RANGE SO
EXPECT FOR MORE PRECIPITATION LATE FRIDAY THROUGH SUNDAY.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E
LAKES SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY
SUNDAY. ALTHOUGH LG SCALE FORCING AND ASSOC SFC LOW APPEAR FAIRLY
WEAK. ALONG WITH THE MOIST FLOW WILL BE WARM AIR...WITH 850 HPA IN
THE +10 TO +14 RANGE THROUGH THE WEEKEND. EVEN WITH THE RAIN
EXPECT TEMPERATURES IN THE 50S TO 60S ON SATURDAY AND 60S TO 70S
ON SUNDAY.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS FOR A BRIEF PERIOD OF
DRY/COOLER WX MONDAY...DUE TO A SHORT WAVE BRINGING NORTHWESTERLY
FLOW WHICH LOOKS TO BE THE HERALD FOR THINGS TO COME. BY MID NEXT
WEEK THE UPPER LEVEL LOW THAT WILL DOMINATE THE PATTERN WILL MOVE
THROUGH BRINGING COLD AIR...WHICH WILL USHER IN MORE NORMAL
TEMPERATURES. THOUGH THERE REMAINS GREAT INCONSISTENCY IN
SPECIFICS THE LATTER HALF OF NEXT WEEK LOOKS TO BE A RETURN TO
WINTER...WHEN ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA THRU
THE GRT LKS.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
03Z TAFS SENT.
ADJUSTED SOME AREAS TO TAKE OUT 1/4SM FG.
ACROSS THE WEST AT JST AND BFD...ADDED IN TEMPO GROUP FOR
SHOWERS...GIVEN LINE OVER EASTERN OH.
EARLIER DISCUSSION BELOW.
BEEN WATCHING STORMS TO THE SOUTH OF PA. THESE TRACKING JUST
EAST OF MDT AND LNS. VERY MOIST SYSTEM FOR THIS TIME OF YR.
SFC LOW AND STRONGEST UPPER LEVEL WINDS LIFT NE OF OUR AREA.
HIGHEST DEWPOINTS TO THE SOUTH OF PA...THUS NOT EXPECTING LINES
OF STORMS OVER THE MIDWEST TO MAKE INTO CENTRAL PA BY EARLY
THU...BUT WILL CONTINUE TO MONITOR.
MAIN THING OVERNIGHT WILL BE LOW CIGS AND LOW LVL WIND SHEAR.
MORE DETAIL BELOW.
NOT A LOT OF FOG AND MOST OF THE RAIN EAST AND NE OF
CENTRAL PA...AS OF 6 PM.
STILL EXPECT LOW CIGS OVERNIGHT AND EARLY THU. MOST LOCATIONS
WILL BE IFR AND MVFR.
EXPECT SOME IMPROVEMENT DURING THE DAY...AS WEAK HIGH PRESSURE
BUILDS TOWARD THE AREA.
OUTLOOK...
CHRISTMAS...NO SIG WX EXPECTED EARLY...MVFR CIGS WITH CHC R LATE
AFTERNOON AND AT NIGHT AS WARM FRONTAL FEATURE LIFTS BACK TO THE
NORTH.
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
&&
.CLIMATE...
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/CERU
AVIATION...MARTIN
CLIMATE...HAGNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
854 PM EST WED DEC 23 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE EAST COAST FOR
THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO PA
THROUGH SATURDAY AND AGAIN EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 8 AM THURSDAY MORNING/...
900 PM UPDATE...
RAIN GONE TO THE EAST AND A LULL IS EXPECTED THROUGH MUCH OF THE
NIGHT UNTIL THE LEFTOVERS FROM THE CONVECTION TO THE WEST ARRIVES.
THE WARM AIR CONTINUES TO STRUGGLE TRYING TO GET TO THE NORTH.
HRRR AND RAP MAKE SOME VERY LIGHT SHOWERS IN THE CENTRAL MTNS
OVERNIGHT...BUT A VERY LOW CHC POP IS ALL THAT IS NECESSARY DUE
TO THE EXPECTED MINISCULE COVERAGE. THE TIMING OF THE STUFF FROM
THE WEST CONTINUES TO BE CLOSER TO MORNING THAN MIDNIGHT. FOG NOT
GETTING THICK BUT WILL CONTINUE TO MENTION PATCHY FOG THRU THE
NIGHT - MAINLY FOR THE RIDGES.
600 PM UPDATE...
RADAR RETURNS DIMINISHING ACROSS THE EAST AS SHORTWAVE AND WEAK
JET MAX SLIDE TO THE E/NE. CLUSTER OF SHRA WITH ONE LTG STRIKE IN
CENT MD LOOKS LIKE IT SHOULD MISS US TO THE SE. SOME BREAKS IN THE
CLOUD COVER NOW OVER WRN PA AND THIS COULD LEAD TO FOG AGAIN
TONIGHT...BUT NOT SIMILAR TO LAST NIGHT. LOW CLOUDS IN PLACE WILL
INITIALLY INSULATE THE AREA AND SOME GRADIENT WIND IS FOUND...ESP
IN THE NW HALF OF THE AREA. BUT ANY CLEARING WILL HELP IT TO
RADIATE WELL - SO AT LEAST PATCHY FOG IS STILL EXPECTED.
PREV...
HIGH LIKELIES AND CATEG POPS CONTINUE THROUGH LATE AFTERNOON AND
EARLY EVENING ACROSS CENTRAL PA AS WARM FRONT LIFTS NORTH OF THE
REGION BY 00Z. REGIONAL RADAR MOSAIC SHOWS ALL BUT THE NORTHWEST
MOUNTAINS WITH WIDESPREAD COVERAGE OF RAIN PRESENTLY...WITH
EMBEDDED MODERATE SHOWERS ACCOMPANYING A NARROW 850 MB JETLET OF
45-50 KTS AS IT LIFTS TOWARDS SRN NY STATE AT MID AFTERNOON.
DESPITE THE CLOUDS AND RAIN...IT IS UNREASONABLY (AND
UNSEASONABLY) MILD ACROSS CENTRAL PA WITH SOME OF MY SOUTHEAST
COUNTIES DUMBFOUNDINGLY APPROACHING 60F IN STEADY RAIN AND
SOUTHEAST LLVL FLOW.
POPS WILL STEADILY DROP OFF FROM WEST TO EAST THIS EVENING AS
BOUNDARY LAYER CONVERGENCE AND UPPER FORCING LARGELY LIFT INTO NY
STATE. FOCUS WILL SHIFT TO THE WEST AT THE SAME TIME HOWEVER AS
COLD FRONT SLOWLY APPROACHES LATE TONIGHT AND THURSDAY
MORNING...WITH INCREASING BOUNDARY LAYER CONVERGENCE AND PERHAPS
SOME ISOLATED THUNDER CROSSING THE OH/PA BORDER. IT`S NOT
INCONCEIVABLE THAT A STRIKE OR TWO COULD SURVIVE INTO THE WEST
CENTRAL MOUNTAINS BY EARLY THU MORNING...BUT FOR NOW AM FOCUSING
ON THE TIME OF MAX HEATING EAST OF THE FRONT FOR T POTENTIAL (MORE
BELOW).
TIGHTENING GRADIENT BTWN BERMUDA HIGH AND INTENSIFYING LOW OVR
THE GRT LKS WILL PRODUCE A BREEZY AND UNSEASONABLY WARM NIGHT WITH
TEMPS STEADY OR SLOWLY RISING TO THE L60S IN MANY SPOTS BY DAWN
THURSDAY. BUFKIT SOUNDINGS INDICATE SOUTHERLY WIND GUSTS OF
25-30KTS ARE POSSIBLE LATE TONIGHT ACROSS THE THE ALLEGHENY
PLATEAU...AS WELL AS THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /8 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
COLD FRONT APPROACHING IN BROAD SOUTHWEST FLOW WILL SAG
SOUTHEASTWARD THROUGHOUT THE DAY ON CHRISTMAS EVE. BRIEF MODERATE
SHOWERS ARE EXPECTED...AND WITH DEWPOINTS IN THE 50S AND MAX
TEMPS ANYWHERE FROM THE L60S ACROSS THE NW MTNS...TO THE L70S OVER
THE LOWER SUSQ VALLEY...MODEL SOUNDINGS WITH UP TO A FEW HUNDRED
J/KG CAPE ARE MORE THAN BELIEVABLE ACROSS THE MIDDLE TO LOWER SUSQ
RIVER VALLEY FROM LATE MORNING THROUGH MID AFTERNOON. ADDED T IN
COLLAB WITH BGM AND PHI...NOTING SPC MRGL OUTLOOK AREA OVER MY
SOUTHEAST AS WELL.
GUIDANCE STILL SUGGESTING MUCH OF THE MID TO LATE AFTERNOON WILL
TREND QUITE NICE AS DRIER AIR ARRIVES. ACROSS THE SOUTHEAST...THE
FRONT WILL LINGER THE LONGEST...AND HAVE MAINTAINED MEASURABLE
POPS THERE THROUGH LATE AFTERNOON.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
A NEGATIVELY TILTED UPPER LEVEL RIDGE OVER THE EAST COAST...AND A
DEEP TROUGH MOVING THROUGH THE CENTRAL UNITED STATES WILL DOMINATE
THE WEATHER THROUGH THE WEEKEND. AS THE RIDGE MOVES EASTWARD THE
UPPER TROUGH PROPAGATES EASTWARD. A SHORT WAVE TROUGH...AND AN
ASSOCIATED FRONT WILL HAVE EXIT TO THE NORTHEAST...ALLOWING FOR DRY
WEATHER THURSDAY NIGHT INTO FRIDAY. THE BULK OF MED RANGE MDL DATA
SUPPORTS A PERIOD OF DRY WX THU NIGHT THROUGH CHRISTMAS DAY AS A WEAK
SFC HIGH BUILDS EAST FROM THE LOWER GRT LKS. THE STALLED FRONTAL
BOUNDARY SOUTH OF PA WILL LIFT NORTH CHRISTMAS NIGHT INTO SATURDAY.
A DEEPER TROUGH MOVING DOWN FROM THE PACIFIC NORTHWEST...AND THROUGH
THE WESTERN US WILL COUPLE WITH MORE ZONAL FLOW TO FORM THE
QUASI-STATIONARY BOUNDARY THAT WILL BRING PRECIPITATION THIS WEEKEND.
ALL MID TO LONG RANGE MODELS HAVE THE TROUGH FORM A CUT OFF LOW. THE
BIG QUESTION IS LOCATION. THE GEFS/GFS/EC ALL VARY IN POSITION
AND STRENGTH...THOUGH THE PREDOMINATE LOCATION IS OVER TEXAS. ALL
MODELS HAVE A MOIST BOUNDARY EXTEND FROM THE TROUGH/LOW THROUGH
NEW ENGLAND. THE FORECAST QUESTION OVER THE WEEKEND WILL THEN BE
WHEN/WHERE THE CONVEYER BELT OF MOISTURE SETS UP AND THE MOVEMENT
OF THE TROUGH/LOW AND THE ASSOCIATED BOUNDARY. THE EC HAS A DEEPER
TROUGH BUT SETS UP THE MOISTURE BELT FASTER...BRINGING THE
BOUNDARY NORTHWARD THROUGH PA FRIDAY NIGHT INTO SATURDAY. THE
GFS/GEFS BRINGS THE BEST MOISTURE SATURDAY AFTERNOON. SO DESPITE
THE VARIANCES ALL PWATS ARE ANOMALOUS IN THE +3 TO +4 RANGE SO
EXPECT FOR MORE PRECIPITATION LATE FRIDAY THROUGH SUNDAY.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E
LAKES SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY
SUNDAY. ALTHOUGH LG SCALE FORCING AND ASSOC SFC LOW APPEAR FAIRLY
WEAK. ALONG WITH THE MOIST FLOW WILL BE WARM AIR...WITH 850 HPA IN
THE +10 TO +14 RANGE THROUGH THE WEEKEND. EVEN WITH THE RAIN
EXPECT TEMPERATURES IN THE 50S TO 60S ON SATURDAY AND 60S TO 70S
ON SUNDAY.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS FOR A BRIEF PERIOD OF
DRY/COOLER WX MONDAY...DUE TO A SHORT WAVE BRINGING NORTHWESTERLY
FLOW WHICH LOOKS TO BE THE HERALD FOR THINGS TO COME. BY MID NEXT
WEEK THE UPPER LEVEL LOW THAT WILL DOMINATE THE PATTERN WILL MOVE
THROUGH BRINGING COLD AIR...WHICH WILL USHER IN MORE NORMAL
TEMPERATURES. THOUGH THERE REMAINS GREAT INCONSISTENCY IN
SPECIFICS THE LATTER HALF OF NEXT WEEK LOOKS TO BE A RETURN TO
WINTER...WHEN ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA THRU
THE GRT LKS.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
BEEN WATCHING STORMS TO THE SOUTH OF PA. THESE TRACKING JUST
EAST OF MDT AND LNS. VERY MOIST SYSTEM FOR THIS TIME OF YR.
SFC LOW AND STRONGEST UPPER LEVEL WINDS LIFT NE OF OUR AREA.
HIGHEST DEWPOINTS TO THE SOUTH OF PA...THUS NOT EXPECTING LINES
OF STORMS OVER THE MIDWEST TO MAKE INTO CENTRAL PA BY EARLY
THU...BUT WILL CONTINUE TO MONITOR.
MAIN THING OVERNIGHT WILL BE LOW CIGS AND LOW LVL WIND SHEAR.
MORE DETAIL BELOW.
NOT A LOT OF FOG AND MOST OF THE RAIN EAST AND NE OF
CENTRAL PA...AS OF 6 PM.
STILL EXPECT LOW CIGS OVERNIGHT AND EARLY THU. MOST LOCATIONS
WILL BE IFR AND MVFR.
EXPECT SOME IMPROVEMENT DURING THE DAY...AS WEAK HIGH PRESSURE
BUILDS TOWARD THE AREA.
OUTLOOK...
CHRISTMAS...NO SIG WX EXPECTED EARLY...MVFR CIGS WITH CHC R LATE
AFTERNOON AND AT NIGHT AS WARM FRONTAL FEATURE LIFTS BACK TO THE
NORTH.
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
&&
.CLIMATE...
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...DANGELO/DEVOIR
SHORT TERM...DEVOIR
LONG TERM...FITZGERALD/CERU
AVIATION...MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1131 PM EST MON DEC 21 2015
.SYNOPSIS...
IT WILL BE UNSETTLED AND UNSEASONABLY MILD WEATHER WILL CONTINUE
THIS WEEK WITH TEMPERATURES ON TRACK TO PEAK NEAR OR BEYOND RECORD
LEVELS ON CHRISTMAS EVE.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LITTLE MORE THAN ISOLATED LIGHT SHOWERS OR SPRINKLES AS OF 9 PM.
PRECIP IS SURGING NE AHEAD OF THE NEXT SHORTWAVE IN THE
FLOW...MOVING INTO WEST VIRGINIA NOW...WITH THE HRRR TIMING THE
RAIN INTO MY SWRN ZONES SHORTLY AFTER MIDNIGHT. HAVE RAISED POPS
CLOSER TO SREF VALUES GIVEN THE LARGE SHIELD OF RAIN UPSTREAM.
TEMPS GOT STUCK IN THE LOWER/MID 40S OVER MUCH OF CWA TODAY...BUT
THEY ALSO WON`T FALL OFF MUCH OVERNIGHT AS LOW LEVEL SW FLOW
CONTINUES TO PUSH WARMER AIR INTO THE REGION.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
PACIFIC SHORTWAVE #2 AND ITS WEAK SURFACE LOW QUICKLY LIFTS
NORTHEAST THROUGH THE LOWER GREAT LAKES INTO THE ST. LAWRENCE
VALLEY/NORTHERN NEW ENGLAND BY 00Z WED. A.M. RAIN SHOULD COME TO
AN END FAIRLY ABRUPTLY EARLY TUESDAY AFTERNOON AS RIDGING BUILDS
IN BEHIND THE DEPARTING SYSTEM. THEREFORE TRENDED HIGH PRECIP
PROBS IN THE MORNING STEADILY DOWNWARD WITH A MAINLY DRY PERIOD
/ALBEIT STILL RATHER CLOUDY/ FROM ROUGHLY 18Z TUESDAY TO 12Z
WEDNESDAY. 24HR RAINFALL AMOUNTS ENDING TUESDAY AFTERNOON SHOULD
AVERAGE BETWEEN 0.25 TO 0.50 INCH IN MOST PLACES WHICH IS RIGHT IN
LINE WITH THE GEFS MEAN. THE SREF MEAN QPF IS A LITTLE WETTER
WHICH IS LIKELY DUE TO THE NAM INFLUENCE BEING TOO VIGOROUS WITH
ITS ASCENT AND MOISTURE FIELDS PER WPC MODEL DIAG.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
THERE ARE SEVERAL MAJOR FORECAST QUESTIONS THIS WEEK. THE MOST
ANOMALOUS IS THE POSSIBLE RECORD TEMPERATURES. THE LONG AND MID
RANGE MODELS CONTINUE TO BE IN FAIR AGREEMENT WITH THE OVERALL
PATTERN AND BY THURSDAY THE SREF ENSEMBLES HAVE +14C TEMPS AT
850HPA. SO RECORD TEMPERATURES ACROSS CENTRAL PA ARE STILL ON
TRACK FOR CHRISTMAS EVE WITH FCST HIGHS OF 60-70F DEGREES WITH
MILD TEMPERATURES ALL WEEK.
THE NEXT QUESTION IS THE TIMING OF SUCCESSIVE SHORT WAVES MOVING
THROUGH THE UPPER LEVEL PATTERN. AS AN UPPER LEVEL TROUGH
MOVES INTO THE GREAT LAKE REGION...A MID LEVEL TROUGH WILL
MOVE THROUGH THE OHIO VALLEY. THIS SHOULD BRING STRONG WARM AND MOIST
SOUTHWESTERLY FLOW INTO THE REGION LATE WEDNESDAY...EARLY
THURSDAY. THE LATEST GEFS HAS PWATS OF +3 TO +4 STANDARD
ANOMALIES. SO THAT EVENT SHOULD HAVE THE HEAVIEST
PRECIPITATION. HAVE INCREASED QPF/S UPWARDS...AS WELL AS ADJUSTED
POPS ACCORDINGLY. THAT WARM FRONT WILL BE FOLLOWED BY A WEAKENING
COLD FRONT CHRISTMAS EVE. THE FROPA WILL KNOCK TEMPERATURES BACK
SOME FOR CHRISTMAS DAY BUT IT SHOULD REMAIN ABOVE NORMAL INTO THE
WEEKEND.
THE MEDIUM RANGE MODEL AND ENSEMBLE GUIDANCE IS NOW TRENDING
TOWARD THE IDEA OF A POTENTIAL SIGNIFICANT RAINFALL AXIS SETTING
UP ALONG THE OLD COLD FRONT THAT COULD TRANSITION TO A QUASI-
STATIONARY BOUNDARY. THE GFS/ECMWF DIFFER TO SOME EXTENT ON THE
EVOLUTION OF THE BOUNDARY BUT BOTH SEEM TO FAVOR A RAINFALL AXIS
FROM ROUGHLY DALLAS TX NEWD THROUGH NEW ENGLAND...SATURDAY NIGHT
INTO SUNDAY. CONFIDENCE IN THE PCPN DETAILS DROPS OFF BY THE END
OF THE PERIOD GIVEN THE MODEL SPREAD AND VARIABILITY IN THE
PLACEMENT OF THE PRECIPITATION- FOCUSING BOUNDARY. HOWEVER THE
BOUNDARY SHOULD DIP SOUTHWARD INTO NEXT WEEK AS THE FLOW BECOMES
MORE ZONAL AS THE LOW MOVES INTO THE CENTRAL UNITED STATES.
&&
.AVIATION /04Z TUESDAY THROUGH SATURDAY/...
SURFACE LOW PRESSURE WILL MOVE FROM SOUTHERN MICHIGAN TO THE
EASTERN GREAT LAKES BY TUESDAY AFTERNOON...PUSHING ITS ASSOCIATED
WARM FRONT NWD ACROSS PENNSYLVANIA. ACCOMPANYING THIS FRONT WILL
BE A POTENT UPPER LEVEL DISTURBANCE AND A PLUME OF DEEP MOISTURE
WITH ITS ORIGIN OVER THE GULF OF MEXICO. THE MOISTURE WILL BE
FUNNELED INTO PENNSYLVANIA LATER TONIGHT INTO EARLY TUESDAY
AFTERNOON...BRINGING PERIODS OF RAIN AND GENERALLY IFR CIGS AND
VSBYS.
IFR CONDITIONS /IN THE FORM OF LOW CIGS - BLANKETING MUCH OF NWRN
PENN AT 04Z/ WILL SLOWLY SPREAD SOUTH AND EAST LATE TONIGHT
REACHING THE CENTRAL RIDGE AND VALLEY REGION BEFORE DAYBREAK. ONLY
A FEW BRIEF SHOWERS ARE EXPECTED EARLY TONIGHT.
THE SUSQ VALLEY AIRFIELDS WILL STAY VFR UNTIL THE 08-10Z TIMEFRAME
FOLLOWED BY A DROP INTO MVFR CIGS...WITH VFR TO MVFR VSBYS IN
PERIODS OF RAIN THAT WILL PERSIST INTO AT LEAST EARLY TUESDAY
AFTERNOON.
STIFF SSW-SWRLY LOW LEVEL JET WILL CONTINUE THE LLWS OVER WESTERN
TERMINALS THROUGH THE OVERNIGHT.
MORE NUMEROUS SHOWERS OR EVEN SOME PERIODS OF STEADIER RAIN WILL
ARRIVE FROM THE SW LATER TONIGHT ACROSS ALL OF CENTRAL AND NRN
PENN AND CONTINUE INTO THE EARLY AFTERNOON TUESDAY.
FAIRLY ABRUPT IMPROVEMENT SHOULD OCCUR LATE TUE AFTERNOON AS
RIDGE QUICKLY WORKS IN BEHIND THE DEPARTING SYSTEM. HOWEVER...THE
LLVL WSW FLOW COULD KEEP LOW CIGS AT KJST AND KBFD FOR SEVERAL
HOURS AFTER THE PASSAGE OF THE WEAK SFC CFRONT.
AFTER SOME IMPROVEMENT AND MAINLY DRY CONDITIONS FOR LATER TUESDAY
INTO WEDNESDAY MORNING...MORE UNSETTLED WEATHER WITH OCCASIONAL
SHOWERS WILL RETURN FOR WEDNESDAY AFTERNOON AND PERSIST INTO
THURSDAY... WITH BREEZY CONDITIONS DEVELOPING.
OUTLOOK...
TUE...WIDESPREAD RESTRICTIONS IN RAIN. SOME IMPROVEMENT LATER IN
THE AFTERNOON.
WED...CIG RESTRICTIONS AND ANOTHER ROUND OF RAIN LIKELY. BREEZY.
THU...CIG RESTRICTIONS POSS WEST. IMPROVING CONDITIONS ELSEWHERE.
CONTINUED BREEZY.
CHRISTMAS...NO SIG WX EXPECTED.
SAT...RESTRICTIONS POSS SOUTH.
&&
.CLIMATE...
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...RXR
LONG TERM...CERU/STEINBUGL
AVIATION...LAMBERT/RXR
CLIMATE...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1211 PM CST TUE DEC 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM CST TUE DEC 22 2015
THE AREA CONTINUES TO BE SOCKED IN WITH LOW CLOUDS AND FOG VERY
EARLY THIS MORNING. THE MAIN CHALLENGE TODAY WILL BE HOW QUICKLY THE
FOG MIXES OUT AND HOW LONG LOWER CLOUDS WILL LINGER ACROSS THE AREA.
A DEEPENING AREA OF LOW PRESSURE PRESENTLY SITUATED OVER THE
NORTHERN ROCKIES IS EXPECTED TO SLIDE INTO WESTERN SOUTH DAKOTA BY
MID MORNING...THEN TRACK INTO EASTERN NORTH DAKOTA BY THIS EVENING.
OUT AHEAD OF THIS SYSTEM...SOUTHERLY WINDS WILL INCREASE ACROSS OUR
AREA THROUGH THE DAY AS THE GRADIENT TIGHTENS...AND WITH THAT EXPECT
TO SEE IMPROVING VISIBILITIES THROUGH THE MORNING INTO EARLY
AFTERNOON. THE RAP SEEMS TO BE HANDLING THE CURRENT BOUNDARY LAYER
MOISTURE THE BEST...AND WOULD INDICATE THAT LOW CLOUDS WILL ERODE
FROM THE SOUTHWEST DURING THE LATER MORNING AND AFTERNOON AS
SOUTH/SOUTHWEST MIXED LAYER WINDS INCREASE. EVEN SO...WILL PROBABLY
REMAIN MOSTLY CLOUDY AS MID AND HIGH CLOUDS INCREASE ACROSS THE
REGION. WITH THE STRONG SOUTHERLY FLOW TODAY...WILL SEE TEMPERATURES
RESPOND ACCORDINGLY...WITH HIGHS A GOOD 15 DEGREES WARMER THAN
YESTERDAY. THIS WILL PLAY OUT TO AFTERNOON TEMPERATURES IN THE UPPER
30S TO LOWER 40S.
FOR TONIGHT...A SHORTWAVE LIFTS FROM SOUTHEASTERN NEBRASKA INTO
IOWA/SOUTHEASTERN MINNESOTA OVERNIGHT ON A SOUTHWESTERLY UPPER LEVEL
FLOW. WHILE THE MAIN ENERGY WILL PASS TO THE EAST OF OUR
CWA...MODELS ARE IN DECENT AGREEMENT WITH POSSIBLY GRAZING PORTIONS
OF OUR NORTHWESTERN IOWA/SOUTHWESTERN MINNESOTA ZONES WITH LIGHT
PRECIPITATION LATER TONIGHT. ALL MODELS ARE INDICATING PLUS 0 C 850
MB TEMPERATURES OVER THAT AREA DURING THAT TIME FRAME...SO
PRECIPITATION TYPE COMES DOWN TO SURFACE TEMPERATURES. PRESENTLY AM
FORECASTING SURFACE TEMPERATURES SLOWLY FALLING INTO THE LOWER 30S
VERY LATE TONIGHT...SO IF PRECIPITATION DEVELOPS CANNOT RULE OUT A
PERIOD OF FREEZING RAIN OVER THAT AREA. IT WILL BE A CLOSE CALL WITH
SURFACE TEMPERATURES JUST HOVERING AROUND THE FREEZING MARK...AND
WITH ONLY LIGHT QPF AM NOT EXPECTING ANY SIGNIFICANT IMPACTS AT THIS
POINT...BUT WILL BE SOMETHING TO KEEP AN EYE ON. IT WILL BE COOLER
BACK TO THE WEST HOWEVER AS A COLD FRONT BEGINS TO SLIDE INTO OUR
WESTERN CWA TOWARD MORNING...WITH LOWS RUNNING FROM NEAR 20 FROM
SOUTH CENTRAL SD THROUGH EAST CENTRAL SD...TO LOWER 30S THROUGH
NORTHWEST IA AS REFERRED TO ABOVE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM CST TUE DEC 22 2015
AN UPPER LEVEL TROUGH LIFTS THROUGH NORTH DAKOTA WEDNESDAY
MORNING WHILE A OVER IOWA. MOISTURE DOES SURGE A LITTLE NORTHWARD IN
THE MORNING AHEAD OF AN ADVANCING COLD FRONT. MODELS A BIT MORE
AGGRESSIVE IN BRINGING SOME LIGHT POPS ACROSS OUR FAR SOUTHEAST
CORNER WHERE MOISTURE APPEARS TO BE DEEPER. DID BUMP UP POPS
SLIGHTLY AND EXPANDED THEM SLIGHTLY WEST OF PREVIOUS FORECASTS GIVEN
THE MORE WESTWARD MODEL TRENDS. PRECIPITATION TYPE IS LESS
CERTAIN...WITH FAIRLY WARM MID AND LOW LEVEL TEMPERATURES...WHILE
COLD AIR BEGINS TO SPREAD EAST AT THE SURFACE. THINK THAT MODELS MAY
BE A TOUCH TOO COLD AT THE SURFACE WHERE THE PRECIPITATION IS
EXPECTED...WITH READINGS RIGHT AROUND FREEZING. EXPECT TYPE TO BE
MAINLY LIGHT RAIN OR POSSIBLY VERY BRIEF FREEZING RAIN NEAR DAYBREAK
IF SURFACE TEMPERATURES COOL ENOUGH. THE PRECIPITATION SHOULD EXIT
THE FORECAST AREA TO THE EAST BY MID-AFTERNOON...AND WITH
TEMPERATURES WARMING BACK ABOVE FREEZING...ANY SLIPPERY SURFACES
FROM -FZRA WILL IMPROVE QUICKLY. WINDS WILL TURN BREEZY FROM THE
NORTHWEST WITH DECENT MIXING BEHIND THE FRONT DURING THE DAY...WHICH
WILL RESULT IN HIGHS IN THE UPPER 20S TO UPPER 30S.
ZONAL FLOW ON THURSDAY WILL SPELL A DRY AND SEASONALLY MILD DAY
ACROSS THE REGION. LIGHT WESTERLY WINDS WEDNESDAY NIGHT WILL TURN
SOUTHWESTERLY ON THURSDAY...AND HELP SCOUR OUT THE PERSISTENT CLOUD
COVERAGE FROM WEST TO EAST AS THE DAY PROGRESSES. TEMPERATURES WILL
BE SIMILAR TO WEDNESDAY WITH HIGHS IN THE UPPER 20S TO UPPER 30S.
CONFIDENCE IS INCREASING WITH THE POTENTIAL FOR SOME LIGHT
PRECIPITATION DEVELOPING FRIDAY INTO SATURDAY. WHILE THERE ARE
SOME TIMING CONCERNS BETWEEN THE MODELS...THEY ARE ALL HINTING AT
A GOOD POTENTIAL FOR SOME STEADY LIGHT TO MODERATE PRECIPITATION
DURING THIS PERIOD. THE GEM IS THE QUICKEST WITH LIFTING A WAVE
NORTHEAST FROM THE CENTRAL ROCKIES INTO THE MID MISSOURI VALLEY AS
EARLY AS LATE FRIDAY MORNING. THE ECMWF LAGS BY NEAR 12
HOURS...WHILE THE GFS IS BETWEEN THE TWO SOLUTIONS. ALL MODELS
BRING A DECENT AMOUNT OF QPF THROUGH THE CWA...HIGHEST WEST OF THE
JAMES RIVER AND NORTH OF I90 - OVER A HALF INCH -OVERNIGHT FRIDAY.
IN THIS AREA...TEMPS WILL BE COLD ENOUGH PRIMARILY FOR
SNOWFALL...WHILE AREAS SOUTH AND EAST MAY SEE MORE OF A MIX. STILL
A LOT OF UNCERTAINTY TO IRON OUT IN FUTURE RUNS...BUT IT WILL BE
SOMETHING TO WATCH CLOSELY.
LESS CONFIDENCE LIES BEYOND SATURDAY...AS THE FOCUS BECOMES THE
PROGRESSION OF A SLOW MOVING UPPER LEVEL LOW WOBBLING TOWARDS THE
RIO GRANDE AREA OF TEXAS ON SUNDAY. ACCORDING TO THE GFS...THIS
LARGE SYSTEM WILL LIFT NORTH NORTHEAST...BECOMING CENTERED OVER THE
KANSAS CITY AREA MONDAY MORNING THEN RAPIDLY HEADS INTO CENTRAL
WISCONSIN MONDAY EVENING. THIS PROGRESSION SEEMS TOO MUCH TOO
BULLISH. THE ECMWF MEANWHILE DOES NOT REACH THE KC AREA UNTIL
TUESDAY MORNING. SUFFICE TO SAY...CONFIDENCE IS LOW...SO JUST RAN
WITH THE ALL BLEND POPS FOR NOW. BOTH SOLUTIONS HOWEVER DO INDICATE
A PRETTY BIG IMPACT FOR OUR AREA WITH THIS STORM SYSTEM.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1210 PM CST TUE DEC 22 2015
STRONG SOUTHERLY FLOW WILL CONTINUE TO ADVECT THE IFR/LIFR/VLIFR
CONDITIONS NORTH AND EASTWARD THROUGH THE REMAINDER OF SW MN AND
NW IA THROUGH EARLY AFTERNOON. HAS ALREADY CLEARED KHON/KFSD/KSUX
BY 18Z. SURFACE WINDS WILL GUST IN EXCESS OF 25 KNOTS THROUGH THE
AFTERNOON. AS WINDS DIMINISH TONIGHT...EXPECT AT LEAST DEVELOPMENT
OF SOME MVFR CONDITIONS FOR KFSD AND KSUX...MAINLY IN TERMS OF
VISIBILITY FOR KFSD...AND PERHAPS A PERIOD OF IFR CEILINGS FOR
KSUX AFTER 04Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
527 AM CST TUE DEC 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM CST TUE DEC 22 2015
THE AREA CONTINUES TO BE SOCKED IN WITH LOW CLOUDS AND FOG VERY
EARLY THIS MORNING. THE MAIN CHALLENGE TODAY WILL BE HOW QUICKLY THE
FOG MIXES OUT AND HOW LONG LOWER CLOUDS WILL LINGER ACROSS THE AREA.
A DEEPENING AREA OF LOW PRESSURE PRESENTLY SITUATED OVER THE
NORTHERN ROCKIES IS EXPECTED TO SLIDE INTO WESTERN SOUTH DAKOTA BY
MID MORNING...THEN TRACK INTO EASTERN NORTH DAKOTA BY THIS EVENING.
OUT AHEAD OF THIS SYSTEM...SOUTHERLY WINDS WILL INCREASE ACROSS OUR
AREA THROUGH THE DAY AS THE GRADIENT TIGHTENS...AND WITH THAT EXPECT
TO SEE IMPROVING VISIBILITIES THROUGH THE MORNING INTO EARLY
AFTERNOON. THE RAP SEEMS TO BE HANDLING THE CURRENT BOUNDARY LAYER
MOISTURE THE BEST...AND WOULD INDICATE THAT LOW CLOUDS WILL ERODE
FROM THE SOUTHWEST DURING THE LATER MORNING AND AFTERNOON AS
SOUTH/SOUTHWEST MIXED LAYER WINDS INCREASE. EVEN SO...WILL PROBABLY
REMAIN MOSTLY CLOUDY AS MID AND HIGH CLOUDS INCREASE ACROSS THE
REGION. WITH THE STRONG SOUTHERLY FLOW TODAY...WILL SEE TEMPERATURES
RESPOND ACCORDINGLY...WITH HIGHS A GOOD 15 DEGREES WARMER THAN
YESTERDAY. THIS WILL PLAY OUT TO AFTERNOON TEMPERATURES IN THE UPPER
30S TO LOWER 40S.
FOR TONIGHT...A SHORTWAVE LIFTS FROM SOUTHEASTERN NEBRASKA INTO
IOWA/SOUTHEASTERN MINNESOTA OVERNIGHT ON A SOUTHWESTERLY UPPER LEVEL
FLOW. WHILE THE MAIN ENERGY WILL PASS TO THE EAST OF OUR
CWA...MODELS ARE IN DECENT AGREEMENT WITH POSSIBLY GRAZING PORTIONS
OF OUR NORTHWESTERN IOWA/SOUTHWESTERN MINNESOTA ZONES WITH LIGHT
PRECIPITATION LATER TONIGHT. ALL MODELS ARE INDICATING PLUS 0 C 850
MB TEMPERATURES OVER THAT AREA DURING THAT TIME FRAME...SO
PRECIPITATION TYPE COMES DOWN TO SURFACE TEMPERATURES. PRESENTLY AM
FORECASTING SURFACE TEMPERATURES SLOWLY FALLING INTO THE LOWER 30S
VERY LATE TONIGHT...SO IF PRECIPITATION DEVELOPS CANNOT RULE OUT A
PERIOD OF FREEZING RAIN OVER THAT AREA. IT WILL BE A CLOSE CALL WITH
SURFACE TEMPERATURES JUST HOVERING AROUND THE FREEZING MARK...AND
WITH ONLY LIGHT QPF AM NOT EXPECTING ANY SIGNIFICANT IMPACTS AT THIS
POINT...BUT WILL BE SOMETHING TO KEEP AN EYE ON. IT WILL BE COOLER
BACK TO THE WEST HOWEVER AS A COLD FRONT BEGINS TO SLIDE INTO OUR
WESTERN CWA TOWARD MORNING...WITH LOWS RUNNING FROM NEAR 20 FROM
SOUTH CENTRAL SD THROUGH EAST CENTRAL SD...TO LOWER 30S THROUGH
NORTHWEST IA AS REFERRED TO ABOVE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM CST TUE DEC 22 2015
AN UPPER LEVEL TROUGH LIFTS THROUGH NORTH DAKOTA WEDNESDAY
MORNING WHILE A OVER IOWA. MOISTURE DOES SURGE A LITTLE NORTHWARD IN
THE MORNING AHEAD OF AN ADVANCING COLD FRONT. MODELS A BIT MORE
AGGRESSIVE IN BRINGING SOME LIGHT POPS ACROSS OUR FAR SOUTHEAST
CORNER WHERE MOISTURE APPEARS TO BE DEEPER. DID BUMP UP POPS
SLIGHTLY AND EXPANDED THEM SLIGHTLY WEST OF PREVIOUS FORECASTS GIVEN
THE MORE WESTWARD MODEL TRENDS. PRECIPITATION TYPE IS LESS
CERTAIN...WITH FAIRLY WARM MID AND LOW LEVEL TEMPERATURES...WHILE
COLD AIR BEGINS TO SPREAD EAST AT THE SURFACE. THINK THAT MODELS MAY
BE A TOUCH TOO COLD AT THE SURFACE WHERE THE PRECIPITATION IS
EXPECTED...WITH READINGS RIGHT AROUND FREEZING. EXPECT TYPE TO BE
MAINLY LIGHT RAIN OR POSSIBLY VERY BRIEF FREEZING RAIN NEAR DAYBREAK
IF SURFACE TEMPERATURES COOL ENOUGH. THE PRECIPITATION SHOULD EXIT
THE FORECAST AREA TO THE EAST BY MID-AFTERNOON...AND WITH
TEMPERATURES WARMING BACK ABOVE FREEZING...ANY SLIPPERY SURFACES
FROM -FZRA WILL IMPROVE QUICKLY. WINDS WILL TURN BREEZY FROM THE
NORTHWEST WITH DECENT MIXING BEHIND THE FRONT DURING THE DAY...WHICH
WILL RESULT IN HIGHS IN THE UPPER 20S TO UPPER 30S.
ZONAL FLOW ON THURSDAY WILL SPELL A DRY AND SEASONALLY MILD DAY
ACROSS THE REGION. LIGHT WESTERLY WINDS WEDNESDAY NIGHT WILL TURN
SOUTHWESTERLY ON THURSDAY...AND HELP SCOUR OUT THE PERSISTENT CLOUD
COVERAGE FROM WEST TO EAST AS THE DAY PROGRESSES. TEMPERATURES WILL
BE SIMILAR TO WEDNESDAY WITH HIGHS IN THE UPPER 20S TO UPPER 30S.
CONFIDENCE IS INCREASING WITH THE POTENTIAL FOR SOME LIGHT
PRECIPITATION DEVELOPING FRIDAY INTO SATURDAY. WHILE THERE ARE
SOME TIMING CONCERNS BETWEEN THE MODELS...THEY ARE ALL HINTING AT
A GOOD POTENTIAL FOR SOME STEADY LIGHT TO MODERATE PRECIPITATION
DURING THIS PERIOD. THE GEM IS THE QUICKEST WITH LIFTING A WAVE
NORTHEAST FROM THE CENTRAL ROCKIES INTO THE MID MISSOURI VALLEY AS
EARLY AS LATE FRIDAY MORNING. THE ECMWF LAGS BY NEAR 12
HOURS...WHILE THE GFS IS BETWEEN THE TWO SOLUTIONS. ALL MODELS
BRING A DECENT AMOUNT OF QPF THROUGH THE CWA...HIGHEST WEST OF THE
JAMES RIVER AND NORTH OF I90 - OVER A HALF INCH -OVERNIGHT FRIDAY.
IN THIS AREA...TEMPS WILL BE COLD ENOUGH PRIMARILY FOR
SNOWFALL...WHILE AREAS SOUTH AND EAST MAY SEE MORE OF A MIX. STILL
A LOT OF UNCERTAINTY TO IRON OUT IN FUTURE RUNS...BUT IT WILL BE
SOMETHING TO WATCH CLOSELY.
LESS CONFIDENCE LIES BEYOND SATURDAY...AS THE FOCUS BECOMES THE
PROGRESSION OF A SLOW MOVING UPPER LEVEL LOW WOBBLING TOWARDS THE
RIO GRANDE AREA OF TEXAS ON SUNDAY. ACCORDING TO THE GFS...THIS
LARGE SYSTEM WILL LIFT NORTH NORTHEAST...BECOMING CENTERED OVER THE
KANSAS CITY AREA MONDAY MORNING THEN RAPIDLY HEADS INTO CENTRAL
WISCONSIN MONDAY EVENING. THIS PROGRESSION SEEMS TOO MUCH TOO
BULLISH. THE ECMWF MEANWHILE DOES NOT REACH THE KC AREA UNTIL
TUESDAY MORNING. SUFFICE TO SAY...CONFIDENCE IS LOW...SO JUST RAN
WITH THE ALL BLEND POPS FOR NOW. BOTH SOLUTIONS HOWEVER DO INDICATE
A PRETTY BIG IMPACT FOR OUR AREA WITH THIS STORM SYSTEM.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 522 AM CST TUE DEC 22 2015
WIDESPREAD IFR/MVFR CONDITIONS THIS MORNING ARE EXPECTED TO
IMPROVE BY LATE MORNING AND EARLY AFTERNOON AS SOUTHERLY WINDS
PICK UP ACROSS THE AREA. WINDS WILL THEN GUST IN EXCESS OF 25 KTS
INTO THE LATE AFTERNOON. WINDS WILL THEN DROP OFF THIS
EVENING...WITH CONDITIONS DETERIORATING IN EASTERN AREAS LATER
TONIGHT AS STRATUS RETURNS AND VISIBILITIES LOWER INTO THE MVFR
RANGE.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...
AVIATION...JM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
418 AM CST TUE DEC 22 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM CST TUE DEC 22 2015
THE AREA CONTINUES TO BE SOCKED IN WITH LOW CLOUDS AND FOG VERY
EARLY THIS MORNING. THE MAIN CHALLENGE TODAY WILL BE HOW QUICKLY THE
FOG MIXES OUT AND HOW LONG LOWER CLOUDS WILL LINGER ACROSS THE AREA.
A DEEPENING AREA OF LOW PRESSURE PRESENTLY SITUATED OVER THE
NORTHERN ROCKIES IS EXPECTED TO SLIDE INTO WESTERN SOUTH DAKOTA BY
MID MORNING...THEN TRACK INTO EASTERN NORTH DAKOTA BY THIS EVENING.
OUT AHEAD OF THIS SYSTEM...SOUTHERLY WINDS WILL INCREASE ACROSS OUR
AREA THROUGH THE DAY AS THE GRADIENT TIGHTENS...AND WITH THAT EXPECT
TO SEE IMPROVING VISIBILITIES THROUGH THE MORNING INTO EARLY
AFTERNOON. THE RAP SEEMS TO BE HANDLING THE CURRENT BOUNDARY LAYER
MOISTURE THE BEST...AND WOULD INDICATE THAT LOW CLOUDS WILL ERODE
FROM THE SOUTHWEST DURING THE LATER MORNING AND AFTERNOON AS
SOUTH/SOUTHWEST MIXED LAYER WINDS INCREASE. EVEN SO...WILL PROBABLY
REMAIN MOSTLY CLOUDY AS MID AND HIGH CLOUDS INCREASE ACROSS THE
REGION. WITH THE STRONG SOUTHERLY FLOW TODAY...WILL SEE TEMPERATURES
RESPOND ACCORDINGLY...WITH HIGHS A GOOD 15 DEGREES WARMER THAN
YESTERDAY. THIS WILL PLAY OUT TO AFTERNOON TEMPERATURES IN THE UPPER
30S TO LOWER 40S.
FOR TONIGHT...A SHORTWAVE LIFTS FROM SOUTHEASTERN NEBRASKA INTO
IOWA/SOUTHEASTERN MINNESOTA OVERNIGHT ON A SOUTHWESTERLY UPPER LEVEL
FLOW. WHILE THE MAIN ENERGY WILL PASS TO THE EAST OF OUR
CWA...MODELS ARE IN DECENT AGREEMENT WITH POSSIBLY GRAZING PORTIONS
OF OUR NORTHWESTERN IOWA/SOUTHWESTERN MINNESOTA ZONES WITH LIGHT
PRECIPITATION LATER TONIGHT. ALL MODELS ARE INDICATING PLUS 0 C 850
MB TEMPERATURES OVER THAT AREA DURING THAT TIME FRAME...SO
PRECIPITATION TYPE COMES DOWN TO SURFACE TEMPERATURES. PRESENTLY AM
FORECASTING SURFACE TEMPERATURES SLOWLY FALLING INTO THE LOWER 30S
VERY LATE TONIGHT...SO IF PRECIPITATION DEVELOPS CANNOT RULE OUT A
PERIOD OF FREEZING RAIN OVER THAT AREA. IT WILL BE A CLOSE CALL WITH
SURFACE TEMPERATURES JUST HOVERING AROUND THE FREEZING MARK...AND
WITH ONLY LIGHT QPF AM NOT EXPECTING ANY SIGNIFICANT IMPACTS AT THIS
POINT...BUT WILL BE SOMETHING TO KEEP AN EYE ON. IT WILL BE COOLER
BACK TO THE WEST HOWEVER AS A COLD FRONT BEGINS TO SLIDE INTO OUR
WESTERN CWA TOWARD MORNING...WITH LOWS RUNNING FROM NEAR 20 FROM
SOUTH CENTRAL SD THROUGH EAST CENTRAL SD...TO LOWER 30S THROUGH
NORTHWEST IA AS REFERRED TO ABOVE.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 416 AM CST TUE DEC 22 2015
AN UPPER LEVEL TROUGH LIFTS THROUGH NORTH DAKOTA WEDNESDAY
MORNING WHILE A OVER IOWA. MOISTURE DOES SURGE A LITTLE NORTHWARD IN
THE MORNING AHEAD OF AN ADVANCING COLD FRONT. MODELS A BIT MORE
AGGRESSIVE IN BRINGING SOME LIGHT POPS ACROSS OUR FAR SOUTHEAST
CORNER WHERE MOISTURE APPEARS TO BE DEEPER. DID BUMP UP POPS
SLIGHTLY AND EXPANDED THEM SLIGHTLY WEST OF PREVIOUS FORECASTS GIVEN
THE MORE WESTWARD MODEL TRENDS. PRECIPITATION TYPE IS LESS
CERTAIN...WITH FAIRLY WARM MID AND LOW LEVEL TEMPERATURES...WHILE
COLD AIR BEGINS TO SPREAD EAST AT THE SURFACE. THINK THAT MODELS MAY
BE A TOUCH TOO COLD AT THE SURFACE WHERE THE PRECIPITATION IS
EXPECTED...WITH READINGS RIGHT AROUND FREEZING. EXPECT TYPE TO BE
MAINLY LIGHT RAIN OR POSSIBLY VERY BRIEF FREEZING RAIN NEAR DAYBREAK
IF SURFACE TEMPERATURES COOL ENOUGH. THE PRECIPITATION SHOULD EXIT
THE FORECAST AREA TO THE EAST BY MID-AFTERNOON...AND WITH
TEMPERATURES WARMING BACK ABOVE FREEZING...ANY SLIPPERY SURFACES
FROM -FZRA WILL IMPROVE QUICKLY. WINDS WILL TURN BREEZY FROM THE
NORTHWEST WITH DECENT MIXING BEHIND THE FRONT DURING THE DAY...WHICH
WILL RESULT IN HIGHS IN THE UPPER 20S TO UPPER 30S.
ZONAL FLOW ON THURSDAY WILL SPELL A DRY AND SEASONALLY MILD DAY
ACROSS THE REGION. LIGHT WESTERLY WINDS WEDNESDAY NIGHT WILL TURN
SOUTHWESTERLY ON THURSDAY...AND HELP SCOUR OUT THE PERSISTENT CLOUD
COVERAGE FROM WEST TO EAST AS THE DAY PROGRESSES. TEMPERATURES WILL
BE SIMILAR TO WEDNESDAY WITH HIGHS IN THE UPPER 20S TO UPPER 30S.
CONFIDENCE IS INCREASING WITH THE POTENTIAL FOR SOME LIGHT
PRECIPITATION DEVELOPING FRIDAY INTO SATURDAY. WHILE THERE ARE
SOME TIMING CONCERNS BETWEEN THE MODELS...THEY ARE ALL HINTING AT
A GOOD POTENTIAL FOR SOME STEADY LIGHT TO MODERATE PRECIPITATION
DURING THIS PERIOD. THE GEM IS THE QUICKEST WITH LIFTING A WAVE
NORTHEAST FROM THE CENTRAL ROCKIES INTO THE MID MISSOURI VALLEY AS
EARLY AS LATE FRIDAY MORNING. THE ECMWF LAGS BY NEAR 12
HOURS...WHILE THE GFS IS BETWEEN THE TWO SOLUTIONS. ALL MODELS
BRING A DECENT AMOUNT OF QPF THROUGH THE CWA...HIGHEST WEST OF THE
JAMES RIVER AND NORTH OF I90 - OVER A HALF INCH -OVERNIGHT FRIDAY.
IN THIS AREA...TEMPS WILL BE COLD ENOUGH PRIMARILY FOR
SNOWFALL...WHILE AREAS SOUTH AND EAST MAY SEE MORE OF A MIX. STILL
A LOT OF UNCERTAINTY TO IRON OUT IN FUTURE RUNS...BUT IT WILL BE
SOMETHING TO WATCH CLOSELY.
LESS CONFIDENCE LIES BEYOND SATURDAY...AS THE FOCUS BECOMES THE
PROGRESSION OF A SLOW MOVING UPPER LEVEL LOW WOBBLING TOWARDS THE
RIO GRANDE AREA OF TEXAS ON SUNDAY. ACCORDING TO THE GFS...THIS
LARGE SYSTEM WILL LIFT NORTH NORTHEAST...BECOMING CENTERED OVER THE
KANSAS CITY AREA MONDAY MORNING THEN RAPIDLY HEADS INTO CENTRAL
WISCONSIN MONDAY EVENING. THIS PROGRESSION SEEMS TOO MUCH TOO
BULLISH. THE ECMWF MEANWHILE DOES NOT REACH THE KC AREA UNTIL
TUESDAY MORNING. SUFFICE TO SAY...CONFIDENCE IS LOW...SO JUST RAN
WITH THE ALL BLEND POPS FOR NOW. BOTH SOLUTIONS HOWEVER DO INDICATE
A PRETTY BIG IMPACT FOR OUR AREA WITH THIS STORM SYSTEM.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1044 PM CST MON DEC 21 2015
CERTAINLY NO SHORTAGE OF IFR TO LIFR CONDITIONS ACROSS THE
FORECAST AREA AT THIS TIME. BELIEVE STRONGLY THAT THIS SITUATION
WILL PREVAIL FOR THE NEXT SEVERAL HOURS. HOWEVER LATE TONIGHT...
THE LOW LEVEL WINDS INCLUDING SURFACE WINDS INCREASE DRAMATICALLY
IN ADVANCE OF THE NEXT SHORT WAVE WHICH MOVES ACROSS THE AREA
TUESDAY MORNING. AS THE WINDS INCREASE FROM THE SOUTH AND
SOUTHEAST...IT IS ANTICIPATED THAT THE VISIBILITY WILL IMPROVE
TOWARD TUESDAY MORNING...BUT THE LOW STRATUS WILL LINGER. INCLUDED
THIS SCENARIO IN THE TAF SITES...ESPECIALLY AT KFSD WHERE THICKER
FOG HAS SET IN.
FURTHER OUT...THE NAM HUMIDITY TIME SECTIONS AND SOUNDINGS
CONTINUE TO SHOW A NEVER ENDING REGIME OF LOW CLOUDS THROUGH THE
DAY TUESDAY. THE ONE EXCEPTION IS AT KSUX WHERE IT SHOWS SOME
CLEARING. THE GFS ON THE OTHER HAND VIRTUALLY SHOWS NO LOW CLOUDS
WITH ITS FORECAST WHICH OBVIOUSLY IS NOT LINING UP WITH REALITY.
WHAT LOOKED THE BEST WAS THE LATEST RAP. THE RAP SHOWS CLEARING IN
THE LOW LAYERS LATE TUESDAY MORNING AND EARLY AFTERNOON WHICH
STANDS TO REASON AS YOU DO NOT HAVE TO GO VERY DEEP INTO NEBRASKA
TO FIND NO STRATUS. SO ONCE THE WINDS SHIFT TO THE SOUTH AS
TONIGHT PROGRESSES...ONE WOULD THINK THAT THE FORECAST AREA WILL
GO VFR TOWARD THE MIDDLE OF THE DAY ON TUESDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...JM
LONG TERM...
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1057 PM CST MON DEC 21 2015
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 239 PM CST MON DEC 21 2015
A VERY WEAK WAVE LIFTING THROUGH THE AREA THIS AFTERNOON. NOTHING
MORE THAN FLURRIES EXPECTED AS A FAIRLY SIGNIFICANT DRY LAYER EXISTS
FROM ABOUT 900MB TO 700MB. OTHERWISE A STRONG WAVE WILL MOVE INTO
THE AREA TONIGHT...BUT THE MAIN EFFECTS WILL BE TO THE NORTH OF THE
CWA. WHILE A ROUGE TENTH OR TWO TENTHS OF AN INCH OF SNOWFALL NOT
IMPOSSIBLE MAINLY ALONG AND NORTH OF INTERSTATE 90...JUST FLURRIES OR
PATCHY LIGHT SNOW ARE EXPECTED. CLOUD COVER SHOULD GRADUALLY
DECREASE THROUGH THE DAY TOMORROW...BUT WE WILL LIKELY REMAIN FAIRLY
ENTRENCHED THROUGH TOMORROW MORNING.
AS FOR TEMPERATURES...AS THE WAVE MOVES THROUGH TO THE NORTH LOW
LEVEL SOUTHERLY FLOW WILL INCREASE THROUGH THE NIGHT...WHICH SHOULD
ALLOW FOR RISING TEMPERATURES IN MANY LOCATIONS. LOWS MILD...TEENS
TO LOWER 20S...WILL RISE TO DAYTIME HIGHS FROM THE UPPER 30S TO MID
40S ON TUESDAY.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 239 PM CST MON DEC 21 2015
ONE PASSING WAVE WILL BRING A CHANCE OF LIGHT SNOW/RAIN TO THE
SOUTHEAST CORNER OF THE AREA TUESDAY NIGHT AND WEDNESDAY MORNING AS
COOLER AIR TRIES TO FILTER IN. THIS WAVE WILL EXIT WEDNESDAY
AFTERNOON AND ANOTHER WAVE WILL APPROACH FROM THE WEST WEDNESDAY
NIGHT. WHILE THE MODELS...ESPECIALLY THE EC...MAKE THIS WAVE A
LITTLE STRONGER THAN THE FIRST ONE...IT STILL LOOKS WEAK AND
PRECIPITATION AMOUNTS WILL BE PRETTY LIGHT IF IN FACT IT DEVELOPS.
WILL KEEP POPS IN THE LOW MENTION RANGE AS WITH THE FIRST WAVE AND
KEEP THE THREAT TIME AT LATE WEDNESDAY NIGHT AND THURSDAY MORNING.
THE POTENTIAL AFFECTED AREA WILL BE THE SOUTHERN EDGE OF THE
FORECAST AREA.
SKIES WILL VARY FROM PARTLY TO MOSTLY CLOUDY TUESDAY NIGHT THROUGH
MOST OF THURSDAY. TEMPERATURES WILL BE A LITTLE COOLER THAN TUESDAY
BUT STILL ABOVE NORMAL. WINDS WILL BE LIGHT TO MODERATE...WITH THE
STRONGEST BREEZE IN THE COOL FLOW WEDNESDAY DAYTIME...POSSIBLY
SURGING TO REACH THE LOWER END OF THE BREEZY CATEGORY.
THE COMPLICATED UPPER LOW DIGGING INTO THE SOUTHWESTERN USA AND
WAVES SPINNING NORTHEAST FROM IT WILL BEING A COUPLE THREATS OF
PRECIPITATION...MAINLY SNOW...TO THE AREA DURING THE FRIDAY THROUGH
MONDAY PERIOD. RIGHT NOW TIMING LOOKS RIGHT FOR THE FIRST SYSTEM
FRIDAY INTO SATURDAY WITH ONE OF THOSE ADVANCE WAVES...AND THE OTHER
THREAT MONDAY AS THE MAIN UPPER LOW COMES UP. MODELS ARE SHOWING
BETTER AGREEMENT ON THE MONDAY SYSTEM THAN THEY HAVE THE LAST
SEVERAL DAYS WITH THE FRIDAY SYSTEM. STILL...TOO EARLY TO GET
EXCITED WITH A LOT OF VARIABLES UNCERTAIN. THE APPROACH OF THIS
DEVELOPING SYSTEM WILL DRAW A LITTLE MORE COOL AIR INTO THE NORTHERN
PLAINS AND GET TEMPERATURES A LITTLE CLOSER TO NORMAL...BUT ARCTIC
AIR HAS NO CHANCE OF APPROACH IN THIS PATTERN
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1044 PM CST MON DEC 21 2015
CERTAINLY NO SHORTAGE OF IFR TO LIFR CONDITIONS ACROSS THE
FORECAST AREA AT THIS TIME. BELIEVE STRONGLY THAT THIS SITUATION
WILL PREVAIL FOR THE NEXT SEVERAL HOURS. HOWEVER LATE TONIGHT...
THE LOW LEVEL WINDS INCLUDING SURFACE WINDS INCREASE DRAMATICALLY
IN ADVANCE OF THE NEXT SHORT WAVE WHICH MOVES ACROSS THE AREA
TUESDAY MORNING. AS THE WINDS INCREASE FROM THE SOUTH AND
SOUTHEAST...IT IS ANTICIPATED THAT THE VISIBILITY WILL IMPROVE
TOWARD TUESDAY MORNING...BUT THE LOW STRATUS WILL LINGER. INCLUDED
THIS SCENARIO IN THE TAF SITES...ESPECIALLY AT KFSD WHERE THICKER
FOG HAS SET IN.
FURTHER OUT...THE NAM HUMIDITY TIME SECTIONS AND SOUNDINGS
CONTINUE TO SHOW A NEVER ENDING REGIME OF LOW CLOUDS THROUGH THE
DAY TUESDAY. THE ONE EXCEPTION IS AT KSUX WHERE IT SHOWS SOME
CLEARING. THE GFS ON THE OTHER HAND VIRTUALLY SHOWS NO LOW CLOUDS
WITH ITS FORECAST WHICH OBVIOUSLY IS NOT LINING UP WITH REALITY.
WHAT LOOKED THE BEST WAS THE LATEST RAP. THE RAP SHOWS CLEARING IN
THE LOW LAYERS LATE TUESDAY MORNING AND EARLY AFTERNOON WHICH
STANDS TO REASON AS YOU DO NOT HAVE TO GO VERY DEEP INTO NEBRASKA
TO FIND NO STRATUS. SO ONCE THE WINDS SHIFT TO THE SOUTH AS
TONIGHT PROGRESSES...ONE WOULD THINK THAT THE FORECAST AREA WILL
GO VFR TOWARD THE MIDDLE OF THE DAY ON TUESDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...08
LONG TERM...
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
937 PM CST WED DEC 23 2015
.UPDATE...
FOR EVENING DISCUSSION.
&&
.DISCUSSION...BUSY EVENING...FINALLY GETTING AROUND TO AN UPDATE.
STORMS ARE NOW FOCUSED AHEAD OF A SURFACE TROUGH. DYNAMICS HAVE
QUICKLY DECREASED AS LOW PRESSURE CENTER HAS LIFTED WELL TO THE
NORTH...BUT SHEAR KEEPS SOME ROTATION GOING WITH STORMS AHEAD OF
THE TROUGH. SOME TRAINING HAS DEVELOPED ALONG THE STRETCHING
BOUNDARY...WITH SOME LOCALIZED FLOODING POSSIBLE ALONG THE BAND.
WATCH HAS BEEN DROPPED FOR BNA AND OUR NORTHWEST COUNTIES.
LATE NIGHT HOURS WILL BE MILD WITH AT LEAST SCATTERED
SHOWERS...BUT SEVERE THREAT WILL DROP OFF IN THE LATE NIGHT
HOURS.
&&
.AVIATION...
00Z TAF DISCUSSION.
MAIN CONCERN DURING THE TAF PERIOD IS THE LINE OF STORMS MOVING
INTO MIDDLE TENNESSEE CURRENTLY. TIMED OUT THE STORMS BASED ON
RADAR AND HRRR AND INCLUDED TEMPO LINE AT CKV AND BNA FOR STRONG
WINDS WHICH WILL BE POSSIBLE WITH THE STRONGER STORMS. FRONT WILL
PUSH THROUGH BUT LOW CLOUDS MAY STICK AROUND PARTICULARLY FARTHER
EAST FOR BNA AND CSV. CSV WILL STAY SOCKED IN WITH IFR AND MVFR
THROUGHOUT THE TAF PERIOD. WINDS WILL RELAX AND SHIFT WEST BEHIND
THE LINE OF STORMS BEFORE RETURNING TO THE SOUTH TOMORROW.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM/AVIATION........13
LONG TERM..................13
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
549 PM CST WED DEC 23 2015
.UPDATE...
FOR 00Z AVIATION DISCUSSION.
&&
.DISCUSSION...
MAIN LINE OF POTENTIALLY SEVERE TSTMS EXTENDS FROM MO BOOTHEEL
SOUTHWARD THROUGH EASTERN AR. SO FAR...SOME HALF INCH TO INCH HAIL
AND SOME WIND DAMAGE HAS OCCURRED ACROSS AR. OUT AHEAD OF THIS
LINE...SOME CONVECTIVE SHOWER DEVELOPMENT IS ONGOING. A FEW LTG
STRIKES HAVE JUST OCCURRED IN NW TN AND WESTERN KY. THIS INCREASE
IN DESTABILIZATION IS EXPECTED TO CONTINUE AS THE AFTERNOON WEARS
ON.
EARLIER THIS MORNING...SPC UPGRADED PART OF OUR AREA TO A MDT RISK.
SO...OVER ROUGHLY THE NW 2/3 OF THE MID STATE...WE HAVE A MDT RISK
IN EFFECT. TO OUR WEST...A TOR WATCH IS CURRENTLY IN EFFECT OVER
WESTERN TN UNTIL 8 PM. ADDITIONALLY...IT SHOULD BE NOTED THAT THE
WATCH IS A PDS...OR PARTICULARLY DANGEROUS SITUATION. HELICITY
VALUES ARE QUITE HIGH WITH THIS EVENT AND THESE HIGHER VALUES
CORRESPOND WELL WITH THE BEST FORCING AND INSTABILITY. THUS...ITS
JUST A MATTER OF TIME BEFORE THE WATCH IS EXTENDED EASTWARD TO
COVER THE MID STATE.
GOING FORWARD...I WILL INCLUDE CATEGORICAL POPS FOR TONIGHT AND
INCLUDE SVR WORDING WITH TORNADOS...DAMAGING WINDS AND LARGE HAIL
ALL BEING A VIABLE THREAT. THE TIMEFRAME STILL LOOKS LIKE THE 4PM
TO MIDNIGHT PERIOD. SOME RESIDUAL SHOWER AND NON SEVERE TSTM
ACTIVITY WILL PERSIST BEHIND THE SEVERE THREAT SO LOW POPS WILL
CONTINUE INTO THU MORNING.
BEHIND THIS SYSTEM...WE ARE STILL LOOKING AT A VERY MILD PATTERN.
THE SFC LOW LIFTS OFF WELL TO THE NORTH AND PREVENTS THE INTRUSION
OF ANY SEASONAL AIR.
ON FRIDAY...POPS WILL INCREASE AGAIN AS A WARM FRONT LIFTS
NORTHWARD. THE WARM FRONT WILL BE RATHER STRONG. IN FACT...AFTER A
HIGH ON FRIDAY IN THE MID 60S...LOW TEMPS WILL ONLY FALL TO THE
LOWER TO MID 60S. STILL CAN`T RULE OUT THE POTENTIAL FOR ONE OR TWO
STRONG STORMS WITH THE WARM FRONT BY FRI NT AS 850 MB FLOW WILL
REACH 30 KTS.
IN THE EXT FCST...STILL LOOKING AT A POWERFUL SYSTEM WHICH WILL
DEVELOP OVER TX ON SATURDAY. THIS FEATURE WILL LIFT OFF TO THE
NORTHEAST. EVENTUALLY...IT WILL DRAG A COLD FRONT THROUGH THE AREA
BY TUESDAY. THE SFC LOW CONFIGURATION DOES FEATURE SOME W-E
ELONGATION AND THUS...THE SEVERE THREAT WILL BE REDUCED. STILL
THOUGH...NEG SHOWALTER VALUES WILL ATTEMPT TO MOVE INTO THE MID
STATE ALONG WITH 50 KTS OF WIND AT THE 850 MB LEVEL. SO...CANNOT
RULE OUT STRONG STORMS ON MON AND MON NT.
TEMPS THOUGH THE EXTENDED WILL CONTINUE TO BE RATHER MILD AND COULD
SET RECORDS. RECORDS FOR THE DATE MAY BE SET ON FRIDAY AND FRIDAY NT
FOR BOTH MAX TEMPS AND MIN TEMPS. BEHIND THE FROPA...THE PREVAILING
AIRMASS LOOKS TO BE OF PACIFIC ORIGIN. FURTHERMORE...UPPER LEVEL
PATTERN GANGS ON TO THE DOMINANCE OF ELEVATED HEIGHT FIELDS. WE ARE
CERTAINLY ON OUR WAY TO THE 2ND WARMEST DECEMBER ON RECORD FOR
NASHVILLE.
&&
.AVIATION...
00Z TAF DISCUSSION.
MAIN CONCERN DURING THE TAF PERIOD IS THE LINE OF STORMS MOVING
INTO MIDDLE TENNESSEE CURRENTLY. TIMED OUT THE STORMS BASED ON
RADAR AND HRRR AND INCLUDED TEMPO LINE AT CKV AND BNA FOR STRONG
WINDS WHICH WILL BE POSSIBLE WITH THE STRONGER STORMS. FRONT WILL
PUSH THROUGH BUT LOW CLOUDS MAY STICK AROUND PARTICULARLY FARTHER
EAST FOR BNA AND CSV. CSV WILL STAY SOCKED IN WITH IFR AND MVFR
THROUGHOUT THE TAF PERIOD. WINDS WILL RELAX AND SHIFT WEST BEHIND
THE LINE OF STORMS BEFORE RETURNING TO THE SOUTH TOMORROW.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........10/REAGAN
LONG TERM..................21
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
556 AM CST TUE DEC 22 2015
.DISCUSSION...
...UNUSUAL LATE DECEMBER SEVERE WEATHER OUTBREAK POSSIBLE ON
WEDNESDAY INTO WEDNESDAY NIGHT...
LATEST SURFACE OBSERVATIONS SHOW UNUSUALLY MILD AND HUMID
CONDITIONS ACROSS THE MID STATE WITH TEMPERATURES AND DEWPOINTS
IN THE MID 50S TO LOW 60S. RADAR SHOWS WIDESPREAD SHOWERS AND A
COUPLE OF THUNDERSTORMS CONTINUE OVER MAINLY THE NORTHWEST HALF
OF THE CWA ATTM. LATEST HRRR RUNS INDICATE MOST OF THIS ACTIVITY
WILL SHIFT NORTHEAST OF THE CWA BY 12Z...WITH ONLY ISOLATED
SHOWERS POSSIBLE THE REST OF TODAY MAINLY ACROSS THE SOUTH.
STRONG WAA WILL CONTINUE TO PUMP GULF MOISTURE INTO THE
AREA TODAY...WITH TEMPERATURES RISING WELL INTO THE 60S BY THIS
AFTERNOON. BY THIS EVENING....00Z MODELS PROG A SMALL H5 SHORTWAVE
TO MOVE FROM THE GULF COAST TOWARDS EAST TN...BRINGING THE NEXT
ROUND OF SHOWERS AND STORMS MAINLY TO THE SOUTHEAST HALF OF THE
CWA TUESDAY NIGHT.
SEVERE THUNDERSTORMS ARE BECOMING INCREASINGLY LIKELY ON
WEDNESDAY INTO WEDNESDAY NIGHT AS 00Z GFS/ECMWF NOW IN GOOD
AGREEMENT TAKING A LARGE H5 NEGATIVELY TILTED TROUGH INTO THE
LOWER MISSISSIPPI AND TENNESSEE VALLEYS DURING THE DAY. SOME
MODELS INCLUDING THE 00Z NMMB DEVELOP CONVECTION ACROSS MS/AL
THAT MOVES RAPIDLY ACROSS EASTERN MIDDLE TENNESSEE BY LATE
MORNING...AND SHOULD THIS OCCUR SOME OF THESE STORMS COULD BE
STRONG OR EVEN SEVERE AS EFFECTIVE CAPE INCREASES UP TO 500 J/KG
AND SFC-6KM SHEAR RISES TO 60 KTS BY 18Z. HOWEVER...MAIN SEVERE
THUNDERSTORM POTENTIAL APPEARS TO BE WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING AS SFC COLD FRONT PUSHES TOWARDS THE MID STATE
FROM THE WEST. SEVERAL MODELS INCLUDING THE 00Z/06Z NAM...00Z
GFS...AND OTHERS ALL SUGGEST CELLULAR CONVECTION...INCLUDING
POTENTIAL SUPERCELLS...WILL DEVELOP ACROSS MS/WEST TN THEN SPREAD
VERY RAPIDLY NORTHEAST AT UP TO 55 KTS ACROSS THE CWA INTO
WEDNESDAY EVENING. SFC TEMPS IN THE 70S WITH DEWPOINTS WELL INTO
THE 60S...CAPES RISING INTO A SEASONABLY HIGH 500-1000 J/KG
RANGE...AND SFC-6KM SHEAR INCREASING TO 70-75KTS BETWEEN 23/18Z
AND 24/06Z ALL SUGGEST LIKELIHOOD FOR SEVERE THUNDERSTORMS DURING
THIS TIMEFRAME. OF NOTABLE CONCERN...SHARPPY 00Z GFS SOUNDINGS
SHOW FAVORABLE CONDITIONS FOR COOL-SEASON TORNADOES WITH A VERY
MOIST BOUNDARY LAYER...SFC-1KM SRH AROUND 400 M2/S2...AND LCLS
BELOW 1000M. SPC HAS ACCORDINGLY BUMPED UP OUR SEVERE RISK INTO
THE ENHANCED CATEGORY FOR WEDNESDAY/WEDNESDAY NIGHT. MAIN NEGATIVE
FACTORS FOR A SEVERE WEATHER OUTBREAK ACROSS OUR CWA ARE THE
HIGHEST INSTABILITY REMAINING TO OUR WEST/SOUTHWEST...UNFAVORABLE
SURFACE LOW PLACEMENT WELL TO OUR NORTH IN THE GREAT
LAKES/CANADA...AND CLIMATOLOGY SHOWING DECEMBER AS THE LEAST
LIKELY MONTH FOR TORNADOES ACROSS MIDDLE TENNESSEE.
AFTER SHOWERS AND STORMS EXIT THE MID STATE EARLY
THURSDAY...APPEARS FORECAST AREA WILL BE MOSTLY DRY DURING THE
DAY WITH TEMPERATURES WARMING WELL INTO THE 70S. THIS DRY PERIOD
WILL BE SHORT LIVED AS WARM FRONT RETURNS NORTHWARD THURSDAY
NIGHT AND ESPECIALLY CHRISTMAS DAY BRINGING YET ANOTHER ROUND OF
WIDESPREAD SHOWERS AND THUNDERSTORMS. VERY WARM AND HUMID
CONDITIONS ARE THEN EXPECTED OVER THE WEEKEND WITH TEMPERATURES IN
THE 70S AND DEWPOINTS IN THE 60S...ALTHOUGH POPS WILL BE LOW WITH
MAINLY JUST ISOLATED SHOWERS ANTICIPATED. GFS/ECMWF CONTINUE TO
STRUGGLE WITH EVOLUTION OF MAIN UPPER TROUGH/CLOSED H5 LOW OVER
THE WESTERN CONUS...WITH ECMWF NEARLY 24 HOURS SLOWER THAN THE GFS
EJECTING SYSTEM EASTWARD. HOWEVER...THIS IS A KNOWN BIAS OF THE
ECMWF...AND LEANED MORE TOWARDS THE GFS WITH HIGHEST POPS ON
MONDAY INTO MONDAY NIGHT AS STRONG COLD FRONT BRINGS ANOTHER ROUND
OF WIDESPREAD SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS TO THE
MID STATE IN THIS VERY UNUSUAL LATE DECEMBER WEATHER PATTERN.
&&
.AVIATION...
12Z TAF DISCUSSION.
POOR FLYING CONDITIONS NEXT 24 HOURS AND BEYOND DUE TO LOW
CEILINGS AND VISIBILITIES. CURRENTLY EXITING SHORT WAVE AXIS
EXTENDS DOWN THROUGH MIDDLE TENNESSEE WITH SHOWER ACTIVITY PUSHING
EAST AND WILL SCATTERED OUT BEFORE PULLING OFF PLATEAU AROUND
15Z-16Z. STILL LOOKING FOR GENERALLY LOW CEILINGS AND FOG DURING
THE DAY...MAY IMPROVE SOME BUT NOT FOR LONG. RAIN MOVES IN AGAIN
TONIGHT WITH A FEW THUNDERSTORMS...ESPECIALLY AFTER MIDNIGHT.
&&
.CLIMATE...
AS FAR AS SEVERE WEATHER CLIMATOLOGY GOES...DECEMBER IS THE LEAST
LIKELY MONTH FOR TORNADOES IN MIDDLE TENNESSEE...WITH ONLY 7 ON
RECORD /INCLUDING 1 IN LINCOLN COUNTY/ SINCE THE EARLY 1800S. THE
LAST TORNADO IN MIDDLE TENNESSEE DURING THE MONTH OF DECEMBER
OCCURRED ON DECEMBER 16 2000 WHEN THE AFOREMENTIONED TORNADO HIT
LINCOLN COUNTY. IN THE OHX CWA...THE LAST DECEMBER TORNADO ON
RECORD OCCURRED IN WILLIAMSON COUNTY ON DECEMBER 24 1988.
THE UNUSUALLY WARM WEATHER OVER THE NEXT SEVERAL DAYS WILL LIKELY
SET SOME RECORDS. WILL SEND OUT A PNS LISTING ALL OF THE RECORD
HIGHS AND RECORD WARM MINIMUM TEMPERATURES FOR NASHVILLE AND
CROSSVILLE LATER THIS MORNING.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........01/BOYD
LONG TERM..................55/SHAMBURGER
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
317 AM CST TUE DEC 22 2015
.DISCUSSION...
...UNUSUAL LATE DECEMBER SEVERE WEATHER OUTBREAK POSSIBLE ON
WEDNESDAY INTO WEDNESDAY NIGHT...
LATEST SURFACE OBSERVATIONS SHOW UNUSUALLY MILD AND HUMID
CONDITIONS ACROSS THE MID STATE WITH TEMPERATURES AND DEWPOINTS
IN THE MID 50S TO LOW 60S. RADAR SHOWS WIDESPREAD SHOWERS AND A
COUPLE OF THUNDERSTORMS CONTINUE OVER MAINLY THE NORTHWEST HALF
OF THE CWA ATTM. LATEST HRRR RUNS INDICATE MOST OF THIS ACTIVITY
WILL SHIFT NORTHEAST OF THE CWA BY 12Z...WITH ONLY ISOLATED
SHOWERS POSSIBLE THE REST OF TODAY MAINLY ACROSS THE SOUTH.
STRONG WAA WILL CONTINUE TO PUMP GULF MOISTURE INTO THE
AREA TODAY...WITH TEMPERATURES RISING WELL INTO THE 60S BY THIS
AFTERNOON. BY THIS EVENING....00Z MODELS PROG A SMALL H5 SHORTWAVE
TO MOVE FROM THE GULF COAST TOWARDS EAST TN...BRINGING THE NEXT
ROUND OF SHOWERS AND STORMS MAINLY TO THE SOUTHEAST HALF OF THE
CWA TUESDAY NIGHT.
SEVERE THUNDERSTORMS ARE BECOMING INCREASINGLY LIKELY ON
WEDNESDAY INTO WEDNESDAY NIGHT AS 00Z GFS/ECMWF NOW IN GOOD
AGREEMENT TAKING A LARGE H5 NEGATIVELY TILTED TROUGH INTO THE
LOWER MISSISSIPPI AND TENNESSEE VALLEYS DURING THE DAY. SOME
MODELS INCLUDING THE 00Z NMMB DEVELOP CONVECTION ACROSS MS/AL
THAT MOVES RAPIDLY ACROSS EASTERN MIDDLE TENNESSEE BY LATE
MORNING...AND SHOULD THIS OCCUR SOME OF THESE STORMS COULD BE
STRONG OR EVEN SEVERE AS EFFECTIVE CAPE INCREASES UP TO 500 J/KG
AND SFC-6KM SHEAR RISES TO 60 KTS BY 18Z. HOWEVER...MAIN SEVERE
THUNDERSTORM POTENTIAL APPEARS TO BE WEDNESDAY AFTERNOON INTO
WEDNESDAY EVENING AS SFC COLD FRONT PUSHES TOWARDS THE MID STATE
FROM THE WEST. SEVERAL MODELS INCLUDING THE 00Z/06Z NAM...00Z
GFS...AND OTHERS ALL SUGGEST CELLULAR CONVECTION...INCLUDING
POTENTIAL SUPERCELLS...WILL DEVELOP ACROSS MS/WEST TN THEN SPREAD
VERY RAPIDLY NORTHEAST AT UP TO 55 KTS ACROSS THE CWA INTO
WEDNESDAY EVENING. SFC TEMPS IN THE 70S WITH DEWPOINTS WELL INTO
THE 60S...CAPES RISING INTO A SEASONABLY HIGH 500-1000 J/KG
RANGE...AND SFC-6KM SHEAR INCREASING TO 70-75KTS BETWEEN 23/18Z
AND 24/06Z ALL SUGGEST LIKELIHOOD FOR SEVERE THUNDERSTORMS DURING
THIS TIMEFRAME. OF NOTABLE CONCERN...SHARPPY 00Z GFS SOUNDINGS
SHOW FAVORABLE CONDITIONS FOR COOL-SEASON TORNADOES WITH A VERY
MOIST BOUNDARY LAYER...SFC-1KM SRH AROUND 400 M2/S2...AND LCLS
BELOW 1000M. SPC HAS ACCORDINGLY BUMPED UP OUR SEVERE RISK INTO
THE ENHANCED CATEGORY FOR WEDNESDAY/WEDNESDAY NIGHT. MAIN NEGATIVE
FACTORS FOR A SEVERE WEATHER OUTBREAK ACROSS OUR CWA ARE THE
HIGHEST INSTABILITY REMAINING TO OUR WEST/SOUTHWEST...UNFAVORABLE
SURFACE LOW PLACEMENT WELL TO OUR NORTH IN THE GREAT
LAKES/CANADA...AND CLIMATOLOGY SHOWING DECEMBER AS THE LEAST
LIKELY MONTH FOR TORNADOES ACROSS MIDDLE TENNESSEE.
AFTER SHOWERS AND STORMS EXIT THE MID STATE EARLY
THURSDAY...APPEARS FORECAST AREA WILL BE MOSTLY DRY DURING THE
DAY WITH TEMPERATURES WARMING WELL INTO THE 70S. THIS DRY PERIOD
WILL BE SHORT LIVED AS WARM FRONT RETURNS NORTHWARD THURSDAY
NIGHT AND ESPECIALLY CHRISTMAS DAY BRINGING YET ANOTHER ROUND OF
WIDESPREAD SHOWERS AND THUNDERSTORMS. VERY WARM AND HUMID
CONDITIONS ARE THEN EXPECTED OVER THE WEEKEND WITH TEMPERATURES IN
THE 70S AND DEWPOINTS IN THE 60S...ALTHOUGH POPS WILL BE LOW WITH
MAINLY JUST ISOLATED SHOWERS ANTICIPATED. GFS/ECMWF CONTINUE TO
STRUGGLE WITH EVOLUTION OF MAIN UPPER TROUGH/CLOSED H5 LOW OVER
THE WESTERN CONUS...WITH ECMWF NEARLY 24 HOURS SLOWER THAN THE GFS
EJECTING SYSTEM EASTWARD. HOWEVER...THIS IS A KNOWN BIAS OF THE
ECMWF...AND LEANED MORE TOWARDS THE GFS WITH HIGHEST POPS ON
MONDAY INTO MONDAY NIGHT AS STRONG COLD FRONT BRINGS ANOTHER ROUND
OF WIDESPREAD SHOWERS AND POTENTIALLY STRONG THUNDERSTORMS TO THE
MID STATE IN THIS VERY UNUSUAL LATE DECEMBER WEATHER PATTERN.
&&
.AVIATION...
06Z TAF DISCUSSION.
MAIN BATCH OF SHOWERS WILL MOVE ACROSS THE PLATEAU (CSV) AREA IN
THE NEXT FEW HOURS...WITH SCT -SHRA TO THE WEST. CIGSS WILL DROP
TO IFR LATE IN THE NIGHT AND AREAS OF BR WILL FORM. CIGS WILL BE
SLOW TO IMPROVE ON TUESDAY...BUT SHOULD CLIMB TO MVFR BY MIDDAY.
WINDS WILL BE MOSTLY SOUTH 7-10KT. A FEW 18KT GUST WILL OCCUR
OVERNIGHT.
&&
.CLIMATE...
AS FAR AS SEVERE WEATHER CLIMATOLOGY GOES...DECEMBER IS THE LEAST
LIKELY MONTH FOR TORNADOES IN MIDDLE TENNESSEE...WITH ONLY 7 ON
RECORD /INCLUDING 1 IN LINCOLN COUNTY/ SINCE THE EARLY 1800S. THE
LAST TORNADO IN MIDDLE TENNESSEE DURING THE MONTH OF DECEMBER
OCCURRED ON DECEMBER 16 2000 WHEN THE AFOREMENTIONED TORNADO HIT
LINCOLN COUNTY. IN THE OHX CWA...THE LAST DECEMBER TORNADO ON
RECORD OCCURRED IN WILLIAMSON COUNTY ON DECEMBER 24 1988.
THE UNUSUALLY WARM WEATHER OVER THE NEXT SEVERAL DAYS WILL LIKELY
SET SOME RECORDS. WILL SEND OUT A PNS LISTING ALL OF THE RECORD
HIGHS AND RECORD WARM MINIMUM TEMPERATURES FOR NASHVILLE AND
CROSSVILLE LATER THIS MORNING.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM/AVIATION........01/BOYD
LONG TERM..................55/SHAMBURGER
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1141 PM CST MON DEC 21 2015
.DISCUSSION...
UPDATED FOR 06Z AVIATION DISCUSSION
&&
.PREV DISCUSSION... /ISSUED 906 PM CST MON DEC 21 2015/
UPDATE...
A COLD FRONT IS ON THE DOOR STEPS OF NORTHEAST ARKANSAS AT THIS
TIME. MOST OF THE HEAVIER SHOWER ACTIVITY HAS PUSHED EAST OF THE
CWA. ALTHOUGH A NEW BAND OF SHOWERS HAS DEVELOPED OVER THE LAST
FEW HOURS JUST AHEAD OF THE FRONT. THE HRRR SHOWS THIS BAND
EXPANDING A TAD AS IT PUSHES EASTWARD ACROSS THE MIDSOUTH. WILL
KEEP POPS AS IS FOR THE REMAINDER OF THE NIGHT.
IN ADDITION...SOME CLEARING MAY OCCUR ACROSS NORTHEAST ARKANSAS
AND THE MISSOURI BOOTHEEL BEHIND THE FRONT. A LITTLE WORRIED DENSE
FOG MAY DEVELOP AS WINDS WILL REMAIN LIGHT. DENSE FOG IS ALREADY
BEING REPORTED NEAR CLINTON ARKANSAS. FOR NOW WILL ADD AREAS OF
FOG FOR AREAS ALONG AND WEST OF THE MISSISSIPPI RIVER. UPDATE WILL
BE OUT SHORTLY.
KRM
DISCUSSION... /ISSUED 348 PM CST MON DEC 21 2015/
WE REMAIN IN A VERY ACTIVE PATTERN. EXPECT RAIN ACROSS AT LEAST A
PORTION OF THE MIDSOUTH EVERY DAY THROUGH THE END OF THE WEEKEND.
ABNORMALLY WARM CONDITIONS WILL ALSO CONTINUE. THIS FORECAST
UPDATE WILL FOCUS PRIMARILY ON THE THREAT FOR SEVERE THUNDERSTORMS
LATE TUESDAY NIGHT INTO WEDNESDAY. HOWEVER...SHOWERS AND
THUNDERSTORMS ARE EXPECTED TO CONTINUE BEFORE AND AFTER THEN.
CURRENTLY RAIN IS MOSTLY CONFINED TO NORTH MISSISSIPPI AND A
SMALL AREA OF WEST TENNESSEE NEAR THE MISSISSIPPI RIVER. EMBEDDED
THUNDERSTORMS HAVE BEEN NOTED...ALTHOUGH NOTHING TO BE CONCERNED
ABOUT. TEMPERATURES ARE IN THE MIDDLE 50S TO LOW 60. A MODERATE
SOUTH WIND IS PUMPING GULF MOISTURE ACROSS THE AREA...SETTING THE
STAGE FOR A POTENTIAL ROUND OF SEVERE WEATHER MIDWEEK.
TOMORROW SHOULD BE WARMER...IN THE LOW 60S TO LOW 70S ACROSS MOST
OF THE REGION...RAIN SHOWERS AND ISOLATED THUNDERSTORMS WILL
CONTINUE...MAINLY IN NORTH MISSISSIPPI.
TEMPERATURES WEDNESDAY WILL BE 22-28 DEGREES ABOVE NORMAL...MAINLY
IN THE MIDDLE 70S. DEW POINTS WILL BE AS HIGH AS THE MIDDLE
60S...CREATING AN AIRMASS THAT FEELS MORE LINE SPRING THEN LATE
DECEMBER.
SYNOPTICALLY...OVER THE NEXT 48 HOURS OR SO A VERY BROAD TROUGH
WILL DEEPEN OVER THE WESTERN US...AND SHIFT INTO THE PLAINS. LATE
TUESDAY NIGHT INTO EARLY WEDNESDAY ITS AXIS SHOULD BE OVER
CENTRAL OKLAHOMA...WITH A SLIGHTLY NEGATIVELY TILTED SHORTWAVE
APPROACHING THE MISSISSIPPI RIVER VALLEY. THE STORM PREDICTION
HAS INCLUDED A LARGE PORTION OF THE MIDSOUTH...MAINLY ALONG AND
SOUTH OF THE INTERSTATE 40 CORRIDOR IN A SLIGHT RISK FOR SEVERE
THUNDERSTORMS. WARM TEMPERATURES AND DEW POINTS IN THE 60S WILL
CREATE VERY UNSTABLE ATMOSPHERIC CONDITIONS...ESPECIALLY FOR
DECEMBER. THE NAM GENERATES CAPE VALUES IN EXCESS OF 1000J/KG AS
FAR NORTH AS MEMPHIS...WITH THE GFS NOT MUCH LOWER IN VALUES...BUT
NOT AS FAR NORTH SPATIALLY. I TYPICALLY DO NOT PUT MUCH FAITH IN
CONVECTIVE PARAMETERS MORE THAN 36 HOURS IN THE FUTURE...BUT
VALUES THAT HIGH ARE HARD TO IGNORE. SHEAR PROFILES ARE ALSO
FAIRLY IMPRESSIVE...AND NOT OVERLY INTENSE WHERE MANY TIMES THEY
ARE A DETRIMENT TO SUSTAINED UPDRAFTS. STRONGLY CURVED HODOGRAPHS
FEATURE 0-3KT HELICITY UP TO 300 M^2/S^2 IN NORTH MISSISSIPPI.
1000-500MB LAPSE RATES ARE BETWEEN 5.8C/KM AND 6.2 C/KM. ORGANIZED
SEVERE STORM ARE POSSIBLE...INCLUDING SUPERCELLS. LARGE
HAIL...LOCALLY DAMAGING WIND GUSTS AND TORNADOES ALL APPEAR
POSSIBLE. HOLIDAY TRAVELERS SHOULD PAY PARTICULARLY CLOSE
ATTENTION TO THIS FORECAST.
THE SEVERE THREAT SHOULD DIMINISH OVERNIGHT AS THE SHORTWAVE
TROUGH SHIFTS ACROSS THE MISSISSIPPI RIVER VALLEY. HOWEVER...THE
LARGER SCALE TROUGH WILL REMAIN ANCHORED OVER THE CENTRAL PLAINS.
AS A RESULT WE MAY SEE A BREAK IN WIDESPREAD RAIN AND
THUNDERSTORMS WEDNESDAY NIGHT INTO THURSDAY. UNFORTUNATELY
SHOWERS AND THUNDERSTORMS ARE EXPECTED TO RETURN CHRISTMAS EVE
NIGHT. HOPEFULLY SANTA CAN GET ALL THE GIFTS DELIVERED ACROSS THE
MIDSOUTH BEFORE THE RAIN BEGINS.
LATE IN THE WORK WEEK...A DEEPENING TROUGH OVER THE SOUTHWEST WILL
RESULT IN STRONG SOUTHWEST FLOW ACROSS THE MIDSOUTH. THIS
TYPICALLY MEANS WET CONDITIONS ACROSS OUR AREA. THIS TIME DOESN`T
LOOK LIKE AN EXCEPTION. WILL CARRY HIGH CHANCE TO EVEN LIKELY POPS
FRIDAY THROUGH THE WEEKEND. TEMPERATURES WILL REMAIN SEASONABLY
WARM.
30
&&
.AVIATION...
06Z TAF CYCLE
IFR/LIFR CONDS ACROSS THE AREA ATTM. SCT SHRAS ARE OCCURRING
MAINLY EAST OF THE MS RIVER AND ACROSS THE MO BOOTHEEL. THIS
ACTIVITY WILL MOVE EAST OF THE AREA OVER THE NEXT FEW HOURS.
EXPECT CONDS TO DETERIORATE TO LIFR AFTER MIDNIGHT AREAWIDE IN
LOW CLOUDS AND FOG. FOG SHOULD BE MORE DENSE AT KJBR SINCE THEY
WILL PROBABLY LOOSE THE CLOUD DECK LATER TONIGHT. STARTING TO SEE
THIS WITH VSBYS LESS THAN 1 MILE JUST TO WEST OF KJBR. CONDS WILL
GRADUALLY IMPROVE TUESDAY MORNING. KJBR SHOULD BREAK OUT AND
BECOME VFR. KMEM IS ON THE FENCE SO WENT WITH A SCT015 TEMPO
THERE FOR NOW. KEPT AN MVFR DECK GOING THROUGH THE DAY AT KMKL
WITH IFR CONDS CONTINUING AT KTUP. FRONT WILL WASH OUT ACROSS THE
AREA AND LOW CLOUDS WILL PUSH BACK NORTH TUE EVENING. RAIN LIKELY
AT KTUP IN THE EVENING.
WINDS WILL CONTINUE TO VEER TO THE WEST/NW AND BECOME LIGHT/VRBL
AT KJBR/KMEM/KMKL AS THE FRONT MOVES INTO THE AREA AND WASHES
OUT. LIGHT SOUTHERLY WINDS WILL REDEVELOP TUESDAY AFTN. FRONT
NEVER REALLY MAKES IT TO KTUP AND WINDS REMAIN S/SSW THERE.
SJM
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1151 AM CST TUE DEC 22 2015
.UPDATE...18Z AVIATION UPDATE BELOW.
&&
.AVIATION...FOG AND LOW CLOUDS HAVE DISSIPATED. VFR CONDITIONS
WILL PREVAIL THROUGH THE AFTERNOON. MVFR TO IFR CEILINGS CURRENTLY
FORECAST TO RE-DEVELOP THIS EVENING 02Z-06Z ALONG AND EAST OF THE
I-35/I-37 CORRIDORS...INCLUDING AUS/SAT. NAM12 AND HRRR SLIGHTLY
FASTER WITH THIS HAPPENING THEN CURRENT TAFS REFLECT. MAY NEED TO
ADJUST TIMING UP SLIGHTLY OF IFR DEVELOPMENT IN FUTURE TAF CYCLE.
LIFR CEILINGS AND VISIBILITIES A POSSIBILITY IN THIS SAME AREA
06Z-12Z...AHEAD OF A COLD FRONT. THE FRONT SHOULD MOVE THROUGH
THE I-35 CORRIDOR 12Z-15Z WED WITH VFR CONDITIONS DEVELOPING AT
AUS/SAT AND A DRY W TO NW WIND. DRT IS EXPECTED TO REMAIN VFR
OVERNIGHT.
&&
.PREV DISCUSSION... /ISSUED 958 AM CST TUE DEC 22 2015/
UPDATE...
BASED ON SATELLITE AND SURFACE OBSERVATIONAL TRENDS WILL EXTEND
THE DENSE FOG ADVISORY FOR ANOTHER HOUR UNTIL 11 AM CST. THERE ARE
NO OTHER CHANGES.
PREV DISCUSSION... /ISSUED 859 AM CST TUE DEC 22 2015/
UPDATE...
THE FOG HAS DISSIPATED ALONG THE HIGHWAY 90 CORRIDOR FROM EAST OF
DEL RIO TO SAN ANTONIO. HAVE CANCELLED THE DENSE FOG ADVISORY FOR
THIS AREA. THE DENSE FOG ADVISORY CONTINUES FOR AREAS FURTHER TO
THE SOUTH AND SOUTHEAST AS AREAS OF DENSE FOG REMAIN. MAY HAVE TO
EXTEND SOME COUNTIES PAST 10 AM AND WILL MONITOR THE DISSIPATION
OF THE FOG IN THESE AREAS. WHERE MENTIONED...HAVE REMOVED SHOWERS
FOR LATE THIS MORNING AS MOISTURE ADVECTION NOT ANTICIPATED UNTIL
MIDDAY AND THUNDER FOR THIS AFTERNOON AS A WARM/DRY SOUTHWESTERLY
MID LEVEL FLOW WILL KEEP THE AIRMASS CAPPED. HAVE REESTABLISHED
TEMPERATURE/DEW POINT/WIND TRENDS FOR THE REMAINDER OF TODAY BASED
ON OBSERVATIONAL TRENDS. OTHERWISE...SOUTH CENTRAL TEXAS FORECAST
IS ON TRACK.
PREV DISCUSSION... /ISSUED 409 AM CST TUE DEC 22 2015/
SHORT TERM (TODAY THROUGH WEDNESDAY)...
MAIN HIGHLIGHTS FOR THE SHORT TERM ARE THE ONGOING DENSE FOG THIS
MORNING AND INCREASING RAIN SHOWER CHANCES LATE TONIGHT INTO
WEDNESDAY MORNING. TEMPERATURES WILL REMAIN ABOVE NORMAL AS
MOISTURE POOLS AHEAD OF A WEAK FRONT THAT WILL MOVE THROUGH
TOMORROW MORNING.
LOW LEVEL AND SURFACE SATURATION IS OCCURRING OVER THE COASTAL
PLAINS INTO THE NORTHERN I-37 CORRIDOR AND IN AREAS JUST SOUTH OF
THE EDWARDS PLATEAU. A DENSE FOG ADVISORY IS IN EFFECT UNTIL 10AM
FOR THESE AREAS. LATEST HRRR/RAP GUIDANCE SUGGESTS THE SATURATION
MAY LINGER INTO THE LATE MORNING HOURS AND WILL NEED TO MONITOR IF
THE DENSE FOG ADVISORY NEEDS TO BE EXTENDED AN ADDITIONAL HOUR IN
THAT PARTICULAR LOCATION. LOW CLOUDS WILL REMAIN OVER THE REGION
THROUGH THE DAY AS LIGHT RAIN SHOWERS/DRIZZLE DEVELOP THROUGH THE
AFTERNOON ACROSS THE COASTAL PLAINS. MOISTURE INFLUX WILL OCCUR
THROUGH THE AFTERNOON FROM THE SOUTH AS A SHORTWAVE TROUGH SHIFTS
OVER NORTH TEXAS AIDING IN LIFT. STRONGEST LIFT WILL OCCUR LATE
TONIGHT INTO WEDNESDAY MORNING WITH MOST RAIN SHOWER ACTIVITY
NORTH AND EAST OF THE REGION. WHILE SOME THUNDERSTORMS COULD BE
POSSIBLE GIVE THE AMOUNT OF INSTABILITY...THE IMPLIED OMEGA VALUES
SUGGEST LIFT MAY NOT BE ENOUGH TO HAVE LARGE SCALE THUNDER
DEVELOPMENT WITH A MAJORITY BEING LIGHT TO MODERATE STREAMING RAIN
SHOWERS. THE FRONT WILL CLEAR THROUGH THE REGION NEAR NOON
WEDNESDAY AND SHOWER BRING THE RAIN CHANCES TO A CLOSE WITH
SLIGHTLY DRIER MOVING.
LONG TERM (THURSDAY THROUGH MONDAY)...
AN ACTIVE WEATHER PATTERN IS EXPECTED DURING THE END OF THE
HOLIDAY WEEK INTO THE WEEKEND WITH MULTIPLE RAIN CHANCES AND A
POTENTIAL MORE POTENT FRONTAL SYSTEM AND STORMS LATE SATURDAY OR
EARLY SUNDAY. WHILE THE ACTIVE PATTERN IS WELL AGREED UPON...THE
DETAILS WILL NEED TO CLOSELY WATCHED NEXT WEEKEND GIVEN THE POTENT
SET-UP BEING ADVERTISED ACROSS MULTI-MODEL SOLUTIONS.
CHRISTMAS EVE WILL BE A TRANSITION DAY AS MOISTURE BEGINS TO
STREAM BACK INTO THE REGION FROM THE SOUTH WITH SOUTHWEST H5 FLOW
OVER THE REGION. LOW END RAIN CHANCES WILL BE LIKELY FOR THE
COASTAL PLAINS AS THE LOW-LEVEL SATURATION OCCURS BUT NO LARGE
SCALE MODERATE SHOWERS ARE EXPECTED AT THIS TIME.
FOR CHRISTMAS DAY...MOISTURE TRANSPORT CONTINUES FROM THE SOUTH
AS STRONG LEE-SIDE CYCLOGENESIS COMMENCES IN COLORADO UNDER THE
STRONG INFLUENCE OF DEEPENING LONGWAVE TROUGH OVER THE LOWER WRN
CONUS. NO EMBEDDED SHORTWAVES SEEM TO EJECT AT THIS STAGE OVER THE
REGION WITH ONLY LIGHT SHOWER ACTIVITY OVER THE COASTAL PLAINS AND
MOSTLY CLOUDY CONDITIONS IN PLACE. TEMPERATURES WILL BE WELL ABOVE
AVERAGE WITH HIGHS LIKELY IN THE MID TO UPPER 70S EVEN DESPITE THE
CLOUDS.
GOING INTO THE HOLIDAY WEEKEND...RAIN SHOWERS AND THUNDERSTORMS
CHANCES WILL INCREASE MID AND UPPER LEVEL WIND SPEEDS INCREASE IN
CONCERT WITH THE VIGOROUSLY DEVELOPING H5 TROUGH. THE MAIN WINDOW
OF CONCERN WILL BE LATE SATURDAY INTO EARLY SUNDAY MORNING WHEN
THE BEST FORCING AND POSSIBLE FRONTAL INFLUENCE MOVE OVER THE
REGION. WHILE A MAJORITY OF THE GLOBAL MODELS SHOW THIS OVERALL
PATTERN...THE PLACEMENT OF THE FRONT AND HOW PROGRESSIVE THE
CLOSED LOW BECOMES WILL ULTIMATELY EFFECT THE EVOLUTION OF ANY
POTENTIAL HEAVY RAIN OR STRONG TO SEVERE THUNDERSTORM EVENT. IT
REMAINS TO UNCLEAR AT THIS STAGE WHAT THE EVOLUTION MAY BE AND
WILL NEED MORE RUNS FOR INCREASED CONFIDENCE. HOWEVER...THE
HOLIDAY WEEKEND WILL NEED TO MONITORED FOR POSSIBLE IMPACT
HAZARDOUS WEATHER. MODELS DO HIGHLIGHT A MAJORITY OF THE HEAVY
RAIN NORTH OF THE REGION WHERE FRONTAL CONVERGENCE WILL BE
STRONGER. THE CURRENT ADVERTISED GFS SOLUTION WOULD POINT TO A
POSSIBLE STRONG TO SEVERE SQUALL LINE. BUT AS JUST STATED
BEFORE...MORE RUNS WILL NEED TO BE MONITORED FOR HIGHER
PROBABILITY IN THIS POSSIBILITY. THE DRYLINE AND FRONT SHOULD PUSH
THROUGH THE REGION BY LATE SUNDAY WITH MONDAY BEING DRIER AND
SLIGHTLY COOLER.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 76 62 78 53 75 / 10 20 10 0 10
AUSTIN BERGSTROM INTL AIRPORT 76 62 79 48 76 / 10 20 10 0 10
NEW BRAUNFELS MUNI AIRPORT 78 61 81 51 77 / 10 20 10 0 10
BURNET MUNI AIRPORT 74 57 76 49 71 / - 20 - 0 -
DEL RIO INTL AIRPORT 76 51 79 48 75 / 0 - 0 0 -
GEORGETOWN MUNI AIRPORT 75 61 76 48 73 / 10 20 10 0 10
HONDO MUNI AIRPORT 77 57 79 48 77 / - 10 - 0 -
SAN MARCOS MUNI AIRPORT 76 62 79 51 76 / 10 20 10 0 10
LA GRANGE - FAYETTE REGIONAL 77 65 79 54 77 / 10 20 20 - 10
SAN ANTONIO INTL AIRPORT 77 62 80 53 77 / 10 10 - 0 10
STINSON MUNI AIRPORT 78 63 81 52 78 / 10 10 - 0 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...RUNYEN
SYNOPTIC/GRIDS...04
PUBLIC SERVICE/DATA COLLECTION...TREADWAY
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
533 AM CST TUE DEC 22 2015
.AVIATION...
LOW CIGS AND VISIBILITIES WILL PREVAIL THIS MORNING. MAINLY
LIFR/VLIFR THROUGH 16-17Z. STRONGER SFC WINDS SHOULD ALLOW FOR
SOME MIXING OF DRIER AIR ALOFT TOWARD THE SFC BUT A STUBBORN TEMP
INVERSION WILL WORK AGAINST MIXING. IF ENOUGH DRY AIR CAN MIX
DOWN...VFR CONDS POSSIBLE FOR A BRIEF WINDOW THIS AFTN. LEANED
TOWARD A HRRR/NAM/GFS BLEND FOR THIS TAF PACKAGE WITH
SIGNIFICANTLY MORE WEIGHT GIVEN TO THE HRRR VSBY/CIGS. A
WEAK UPPER LEVEL TROUGH WILL MOVE THROUGH THE REGION TONIGHT AND
THIS FEATURE SHOULD PROVIDE ENOUGH LIFT TO INITIATE A FEW SHOWERS.
WILL CARRY A VCSH AFTER 03Z FOR ALL TAF SITES. SEA FOG WILL PLAGUE
KGLS AS WELL AND ANY IMPROVEMENT IN VSBY/CIGS DURING THE DAY WILL
BE SHORT LIVED. CONDS REMAIN FAVORABLE FOR SEA FOG THROUGH THE END
OF THE WEEK. 43
&&
.PREV DISCUSSION... /ISSUED 447 AM CST TUE DEC 22 2015/
DISCUSSION...
EARLY MORNING OBSERVATIONS AROUND SOUTHEAST TEXAS SHOW NEAR ZERO
VISIBILITIES FROM DENSE FOG... AND THESE CONDITIONS ARE EXPECTED
TO CONTINUE THROUGH MUCH OF THE MORNING. HAVE EXTENDED THE DENSE
FOG ADVISORY THROUGH 10 AM CST BUT CONCERNED THAT THIS MAY NEED TO
BE EXTENDED WITH THE MORNING UPDATE. HRRR VISIBILITY TRENDS SHOW
FOG LINGERING INTO LATE MORNING... AND THIS SOLUTION MAKES SOME
SENSE WITH FORECAST SOUNDINGS SHOWING A STOUT MORNING INVERSION
ALSO PERSISTING INTO LATE MORNING. THIS WOULD DELAY THE ONSET OF
DAYTIME MIXING AND ALLOW FOG TO HOLD ON A BIT LONGER THAN
ANTICIPATED.
FOR THE REMAINDER OF THE DAY... MESSY SOUTHWEST FLOW WILL CONTINUE
ALOFT WITH LARGE SCALE TROUGHING IN PLACE ACROSS THE WESTERN
CONUS. EARLY MORNING WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH
LOCATED OVER THE MEXICAN STATE OF COAHUILA EMBEDDED IN THE FLOW
ALOFT WITH REGIONAL RADAR MOSAIC SHOWING SHOWERS WITH EMBEDDED
THUNDERSTORMS STREAMING ACROSS THE NORTHWESTERN GULF. AS THE
SHORTWAVE OVER MEXICO MOVES TOWARDS THE REGION THIS MORNING...
EXPECT SHOWER AND THUNDERSTORM COVERAGE TO EXPAND NORTHWARD INTO
SOUTHEAST TEXAS. THE ACTUAL TRAJECTORY OF THIS WAVE WILL PLAY A
BIG ROLE IN HOW FAR NORTH RAIN WILL EXTEND INLAND TODAY... AND FOR
NOW ONLY HIGHLIGHTING 20 TO 30 POPS WITH GREATEST COVERAGE
EXPECTED ALONG AND SOUTH OF INTERSTATE 10.
FOR THIS EVENING AND TONIGHT... EXPECT ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS TO DEVELOP ACROSS THE REGION. AS A SHORTWAVE
TROUGH SWINGS ACROSS THE SOUTHERN PLAINS THIS EVENING...
INCREASING FORCING FOR ASCENT WILL OVERSPREAD THE EASTERN HALF OF
THE STATE WITH ISOLATED TO SCATTERED SHOWERS AND POSSIBLY
THUNDERSTORMS BLOSSOMING IN RESPONSE. HIGHLIGHTING GREATEST
CHANCES /40 TO 50 POPS/ OVER THE NORTHERN AND NORTHEASTERN
COUNTIES CLOSER TO THE PASSING TROUGH. SPC IS CURRENTLY
HIGHLIGHTING THESE AREAS WITH A MARGINAL RISK FOR SEVERE
THUNDERSTORMS. FORECAST SOUNDINGS AT COLLEGE STATION AND LUFKIN DO
ADVERTISE MID LEVEL LAPSE RATES AROUND 6-7 KM/C... MLCAPE VALUES
EXCEEDING 1000 J/KG OVERNIGHT... AND 0-6 KM SHEAR VALUES AROUND 40
TO 50 KNOTS. GIVEN THIS... CANNOT RULE OUT AN ISOLATED STRONGER TO
POSSIBLY SEVERE STORM OVER THE NORTHERN AND NORTHEASTERN COUNTIES.
HOWEVER... THESE STORMS WOULD BE THE EXCEPTION AND NOT THE RULE
DUE TO SOME UNCERTAINTY IN ACTUAL THUNDERSTORM COVERAGE.
AS THE SOUTHERN PLAINS SHORTWAVE LIFTS NORTHEAST... IT WILL SEND
A WEAK FRONTAL BOUNDARY INTO THE REGION DURING THE DAY ON
WEDNESDAY. EXPECT LINGERING SHOWERS AND THUNDERSTORMS AHEAD OF THE
BOUNDARY ON WEDNESDAY MORNING. HOWEVER... INCREASINGLY SOUTHWEST
FLOW ABOVE THE SURFACE AS THE TROUGH DEPARTS WILL ADVECT DRIER AIR
OVER THE REGION AND THIS WILL RESULT IN A BRIEF RESPITE IN RAIN
CHANCES WEDNESDAY AFTERNOON THROUGH CHRISTMAS EVE MORNING. HOW
FAR INTO THE REGION THE BOUNDARY WILL MOVE IS STILL A LITTLE
UNCERTAIN... WITH 700 MB FLOW BECOMING INCREASINGLY PARALLEL TO
THE BOUNDARY /LIMITING SUPPORT ALOFT FOR FORWARD MOTION/... BUT
WITH LIMITED AVAILABLE MOISTURE THIS FEATURE IS NOT EXPECTED HAVE
AN IMPACT ON ANY RAIN CHANCES. THE STALLED FRONTAL BOUNDARY IS
EXPECTED TO LIFT NORTH DURING THE DAY ON CHRISTMAS EVE WITH
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BEHIND THIS
BOUNDARY AND PERSISTING OFF-AND-ON THROUGH CHRISTMAS INTO
SATURDAY.
A TROUGH MOVING ALONG THE WEST COAST IS EXPECTED TO CUT OFF
SATURDAY SOMEWHERE OVER NORTHERN MEXICO/WEST TEXAS. THIS CLOSED
LOW IS CURRENTLY FORECAST TO MOVE ACROSS THE STATE SUNDAY THROUGH
TUESDAY... SENDING A STRONG COLD FRONT TOWARDS THE REGION LATE
SUNDAY. TIMING DIFFERENCES STILL EXIST BETWEEN MEDIUM RANGE
GUIDANCE... WITH THE GFS BLASTING THE FRONT THROUGH THE STATE BY
EARLY MONDAY MORNING AND THE EUROPEAN CLEARING THE STATE ALMOST A
FULL DAY LATER.
GIVEN THE TIMING DIFFERENCES... OPTED TO TAKE A BLEND OF MODEL
SOLUTIONS FOR THE WEEKEND FORECAST. WILL NEED TO CONTINUE TO
MONITOR THIS PORTION OF THE FORECAST AS CIPS ANALOG GUIDANCE
INDICATES AT LEAST A LOW SEVERE WEATHER THREAT WITH THIS PATTERN FOR
THE SUNDAY/MONDAY TIMEFRAME AS A LINE OF THUNDERSTORMS DEVELOPS ALONG
THE FRONT. NAEFS ANOMALIES ARE ALSO SHOWING FORECAST PRECIPITABLE
WATER VALUES AROUND TWO STANDARD DEVIATIONS ABOVE CLIMATOLOGICAL
NORMALS... RAISING CONCERNS A HEAVY RAINFALL THREAT /BUT THIS MAY
BE MITIGATED BY THE SPEED OF THE SYSTEM/. WHEN THIS SYSTEM CLEARS
THE REGION THOUGH /BY THE BEGINNING OF NEXT WEEK/... DRIER
WEATHER AND HIGH TEMPERATURES NEAR SEASONAL NORMALS IN THE LOWER
60S ARE EXPECTED.
HUFFMAN
MARINE...
DENSE FOG WILL CONTINUE TO PLAGUE THE COASTAL WATERS AND ADJACENT
BAYS THROUGH THE MORNING. WILL CARRY THE DENSE FOG ADVISORY THROUGH
16Z AND THIS MAY NEED TO BE EXTENDED AS A STUBBORN TEMP INVERSION
LIMITS MIXING. CONDITIONS WILL REMAIN FAVORABLE FOR AREAS OF FOG TO
PERSIST THROUGH THE END OF THE WEEK. MARINERS ARE URGED TO CHECK
THE LATEST FORECAST AND PREPARE FOR RAPIDLY CHANGING CONDITIONS.
A WEAK PRESSURE GRADIENT WILL TIGHTEN THROUGH THE DAY AS LOW
PRESSURE OVER THE WESTERN HIGH PLAINS DEEPENS. MODERATE TO
OCCASIONALLY STRONG ONSHORE WINDS WILL DEVELOP BY EVENING IN
RESPONSE TO THE TIGHTENING GRADIENT. SCEC/SCA CONDS POSSIBLE TONIGHT
INTO WEDNESDAY AS THE STORM SYSTEM OVER THE PLAINS MOVES NORTHEAST.
A LULL IN THE ONSHORE WINDS IS EXPECTED WED NITE/THU BUT WINDS
EXPECTED TO INCREASE AGAIN ON FRI AS ANOTHER AREA OF LOW PRESSURE
DEVELOPS AND INTENSIFIES OVER THE WESTERN PLAINS. A FRONT WILL
CROSS THE COASTAL WATERS NEXT SUN NIGHT AND A WIND SHIFT TO THE
W-NW IS EXPECTED. THE FRONT COULD BRING A LINE OF STRONG STORMS
ACROSS THE MARINE AREAS SUN/MON. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 75 66 77 55 75 / 20 40 30 10 10
HOUSTON (IAH) 74 65 78 58 77 / 20 30 40 10 20
GALVESTON (GLS) 70 66 73 63 72 / 30 30 40 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...
CHAMBERS...COLORADO...FORT BEND...GALVESTON...GRIMES...
HARRIS...HOUSTON...JACKSON...LIBERTY...MADISON...
MATAGORDA...MONTGOMERY...POLK...SAN JACINTO...TRINITY...
WALKER...WALLER...WASHINGTON...WHARTON.
GM...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION FROM 3 PM CST THIS AFTERNOON
THROUGH LATE TONIGHT FOR THE FOLLOWING ZONES: WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...
WATERS FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION...CORRECTED
NWS HOUSTON/GALVESTON TX
447 AM CST TUE DEC 22 2015
.DISCUSSION...
EARLY MORNING OBSERVATIONS AROUND SOUTHEAST TEXAS SHOW NEAR ZERO
VISIBILITIES FROM DENSE FOG... AND THESE CONDITIONS ARE EXPECTED
TO CONTINUE THROUGH MUCH OF THE MORNING. HAVE EXTENDED THE DENSE
FOG ADVISORY THROUGH 10 AM CST BUT CONCERNED THAT THIS MAY NEED TO
BE EXTENDED WITH THE MORNING UPDATE. HRRR VISIBILITY TRENDS SHOW
FOG LINGERING INTO LATE MORNING... AND THIS SOLUTION MAKES SOME
SENSE WITH FORECAST SOUNDINGS SHOWING A STOUT MORNING INVERSION
ALSO PERSISTING INTO LATE MORNING. THIS WOULD DELAY THE ONSET OF
DAYTIME MIXING AND ALLOW FOG TO HOLD ON A BIT LONGER THAN
ANTICIPATED.
FOR THE REMAINDER OF THE DAY... MESSY SOUTHWEST FLOW WILL CONTINUE
ALOFT WITH LARGE SCALE TROUGHING IN PLACE ACROSS THE WESTERN
CONUS. EARLY MORNING WATER VAPOR IMAGERY SHOWS A SHORTWAVE TROUGH
LOCATED OVER THE MEXICAN STATE OF COAHUILA EMBEDDED IN THE FLOW
ALOFT WITH REGIONAL RADAR MOSAIC SHOWING SHOWERS WITH EMBEDDED
THUNDERSTORMS STREAMING ACROSS THE NORTHWESTERN GULF. AS THE
SHORTWAVE OVER MEXICO MOVES TOWARDS THE REGION THIS MORNING...
EXPECT SHOWER AND THUNDERSTORM COVERAGE TO EXPAND NORTHWARD INTO
SOUTHEAST TEXAS. THE ACTUAL TRAJECTORY OF THIS WAVE WILL PLAY A
BIG ROLE IN HOW FAR NORTH RAIN WILL EXTEND INLAND TODAY... AND FOR
NOW ONLY HIGHLIGHTING 20 TO 30 POPS WITH GREATEST COVERAGE
EXPECTED ALONG AND SOUTH OF INTERSTATE 10.
FOR THIS EVENING AND TONIGHT... EXPECT ANOTHER ROUND OF SHOWERS
AND THUNDERSTORMS TO DEVELOP ACROSS THE REGION. AS A SHORTWAVE
TROUGH SWINGS ACROSS THE SOUTHERN PLAINS THIS EVENING...
INCREASING FORCING FOR ASCENT WILL OVERSPREAD THE EASTERN HALF OF
THE STATE WITH ISOLATED TO SCATTERED SHOWERS AND POSSIBLY
THUNDERSTORMS BLOSSOMING IN RESPONSE. HIGHLIGHTING GREATEST
CHANCES /40 TO 50 POPS/ OVER THE NORTHERN AND NORTHEASTERN
COUNTIES CLOSER TO THE PASSING TROUGH. SPC IS CURRENTLY
HIGHLIGHTING THESE AREAS WITH A MARGINAL RISK FOR SEVERE
THUNDERSTORMS. FORECAST SOUNDINGS AT COLLEGE STATION AND LUFKIN DO
ADVERTISE MID LEVEL LAPSE RATES AROUND 6-7 KM/C... MLCAPE VALUES
EXCEEDING 1000 J/KG OVERNIGHT... AND 0-6 KM SHEAR VALUES AROUND 40
TO 50 KNOTS. GIVEN THIS... CANNOT RULE OUT AN ISOLATED STRONGER TO
POSSIBLY SEVERE STORM OVER THE NORTHERN AND NORTHEASTERN COUNTIES.
HOWEVER... THESE STORMS WOULD BE THE EXCEPTION AND NOT THE RULE
DUE TO SOME UNCERTAINTY IN ACTUAL THUNDERSTORM COVERAGE.
AS THE SOUTHERN PLAINS SHORTWAVE LIFTS NORTHEAST... IT WILL SEND
A WEAK FRONTAL BOUNDARY INTO THE REGION DURING THE DAY ON
WEDNESDAY. EXPECT LINGERING SHOWERS AND THUNDERSTORMS AHEAD OF THE
BOUNDARY ON WEDNESDAY MORNING. HOWEVER... INCREASINGLY SOUTHWEST
FLOW ABOVE THE SURFACE AS THE TROUGH DEPARTS WILL ADVECT DRIER AIR
OVER THE REGION AND THIS WILL RESULT IN A BRIEF RESPITE IN RAIN
CHANCES WEDNESDAY AFTERNOON THROUGH CHRISTMAS EVE MORNING. HOW
FAR INTO THE REGION THE BOUNDARY WILL MOVE IS STILL A LITTLE
UNCERTAIN... WITH 700 MB FLOW BECOMING INCREASINGLY PARALLEL TO
THE BOUNDARY /LIMITING SUPPORT ALOFT FOR FORWARD MOTION/... BUT
WITH LIMITED AVAILABLE MOISTURE THIS FEATURE IS NOT EXPECTED HAVE
AN IMPACT ON ANY RAIN CHANCES. THE STALLED FRONTAL BOUNDARY IS
EXPECTED TO LIFT NORTH DURING THE DAY ON CHRISTMAS EVE WITH
SCATTERED SHOWERS AND THUNDERSTORMS DEVELOPING BEHIND THIS
BOUNDARY AND PERSISTING OFF-AND-ON THROUGH CHRISTMAS INTO
SATURDAY.
A TROUGH MOVING ALONG THE WEST COAST IS EXPECTED TO CUT OFF
SATURDAY SOMEWHERE OVER NORTHERN MEXICO/WEST TEXAS. THIS CLOSED
LOW IS CURRENTLY FORECAST TO MOVE ACROSS THE STATE SUNDAY THROUGH
TUESDAY... SENDING A STRONG COLD FRONT TOWARDS THE REGION LATE
SUNDAY. TIMING DIFFERENCES STILL EXIST BETWEEN MEDIUM RANGE
GUIDANCE... WITH THE GFS BLASTING THE FRONT THROUGH THE STATE BY
EARLY MONDAY MORNING AND THE EUROPEAN CLEARING THE STATE ALMOST A
FULL DAY LATER.
GIVEN THE TIMING DIFFERENCES... OPTED TO TAKE A BLEND OF MODEL
SOLUTIONS FOR THE WEEKEND FORECAST. WILL NEED TO CONTINUE TO
MONITOR THIS PORTION OF THE FORECAST AS CIPS ANALOG GUIDANCE
INDICATES AT LEAST A LOW SEVERE WEATHER THREAT WITH THIS PATTERN FOR
THE SUNDAY/MONDAY TIMEFRAME AS A LINE OF THUNDERSTORMS DEVELOPS ALONG
THE FRONT. NAEFS ANOMALIES ARE ALSO SHOWING FORECAST PRECIPITABLE
WATER VALUES AROUND TWO STANDARD DEVIATIONS ABOVE CLIMATOLOGICAL
NORMALS... RAISING CONCERNS A HEAVY RAINFALL THREAT /BUT THIS MAY
BE MITIGATED BY THE SPEED OF THE SYSTEM/. WHEN THIS SYSTEM CLEARS
THE REGION THOUGH /BY THE BEGINNING OF NEXT WEEK/... DRIER
WEATHER AND HIGH TEMPERATURES NEAR SEASONAL NORMALS IN THE LOWER
60S ARE EXPECTED.
HUFFMAN
&&
.MARINE...
DENSE FOG WILL CONTINUE TO PLAGUE THE COASTAL WATERS AND ADJACENT
BAYS THROUGH THE MORNING. WILL CARRY THE DENSE FOG ADVISORY THROUGH
16Z AND THIS MAY NEED TO BE EXTENDED AS A STUBBORN TEMP INVERSION
LIMITS MIXING. CONDITIONS WILL REMAIN FAVORABLE FOR AREAS OF FOG TO
PERSIST THROUGH THE END OF THE WEEK. MARINERS ARE URGED TO CHECK
THE LATEST FORECAST AND PREPARE FOR RAPIDLY CHANGING CONDITIONS.
A WEAK PRESSURE GRADIENT WILL TIGHTEN THROUGH THE DAY AS LOW
PRESSURE OVER THE WESTERN HIGH PLAINS DEEPENS. MODERATE TO
OCCASIONALLY STRONG ONSHORE WINDS WILL DEVELOP BY EVENING IN
RESPONSE TO THE TIGHTENING GRADIENT. SCEC/SCA CONDS POSSIBLE TONIGHT
INTO WEDNESDAY AS THE STORM SYSTEM OVER THE PLAINS MOVES NORTHEAST.
A LULL IN THE ONSHORE WINDS IS EXPECTED WED NITE/THU BUT WINDS
EXPECTED TO INCREASE AGAIN ON FRI AS ANOTHER AREA OF LOW PRESSURE
DEVELOPS AND INTENSIFIES OVER THE WESTERN PLAINS. A FRONT WILL
CROSS THE COASTAL WATERS NEXT SUN NIGHT AND A WIND SHIFT TO THE
W-NW IS EXPECTED. THE FRONT COULD BRING A LINE OF STRONG STORMS
ACROSS THE MARINE AREAS SUN/MON. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 75 66 77 55 75 / 20 40 30 10 10
HOUSTON (IAH) 74 65 78 58 77 / 20 30 40 10 20
GALVESTON (GLS) 70 66 73 63 72 / 30 30 40 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: AUSTIN...BRAZORIA...BRAZOS...BURLESON...
CHAMBERS...COLORADO...FORT BEND...GALVESTON...GRIMES...
HARRIS...HOUSTON...JACKSON...LIBERTY...MADISON...
MATAGORDA...MONTGOMERY...POLK...SAN JACINTO...TRINITY...
WALKER...WALLER...WASHINGTON...WHARTON.
GM...DENSE FOG ADVISORY UNTIL 10 AM CST THIS MORNING FOR THE
FOLLOWING ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS
FROM FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...
WATERS FROM HIGH ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
1203 AM CST TUE DEC 22 2015
.UPDATE...HAVE ISSUED A DENSE FOG ADVISORY FOR THE COASTAL PLAINS
INTO BEXAR COUNTY AND FOR LOCATIONS ALONG AND SOUTH OF THE EDWARDS
PLATEAU AS VISIBILITIES DOWN AT OR BELOW ONE QUARTER OF A MILE
WILL BE LIKELY. VISIBILITIES HAVE ALREADY BEGUN TO DECREASE LATE
THIS EVENING AND THIS TREND IS EXPECTED TO CONTINUE GIVEN THE RAP
NEAR SURFACE SATURATION INDICATIONS. DEWPOINT DEPRESSIONS ARE NEAR
ZERO ALREADY AND THE RAP OUTPUT SUGGESTS THESE CONDITIONS THAT
WILL PROMOTE AREAS OF DENSE FOG WILL PERSIST THROUGH THE OVERNIGHT
AND MORNING HOURS. WE WILL NEED TO MONITOR HOW LOW THE DEPRESSIONS
GET ACROSS THE NORTHERN PORTIONS OF I-35 THROUGH DAWN AND SEE IF
AN EXPANSION OF THE ADVISORY IS NEEDED.
THE AREAS OF DENSE FOG SHOULD DECREASE BY 9 TO 10 AM BUT LOW
CLOUDS WILL LINGER ACROSS THE PLAINS AND THE RIO GRANDE TO EDWARDS
PLATEAU INTO THE EARLY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 1032 PM CST MON DEC 21 2015/
AVIATION...
TEMPERATURE/DEWPOINT DEPRESSIONS ARE NEARING ZERO IN SPOTS ALONG
AND OFF THE ESCARPMENT RESULTING IN BR/FG WITH LCL VSBYS 1/4 MILE
OR LESS ALONG AND SE OF A KDRT TO K5C1 TO KTPL LINE. EXPECT THIS
TO CONTINUE OVERNIGHT INTO TUESDAY MORNING AND HAVE MENTIONED
IFR/MVFR BR AT ALL TAF SITES WITH TEMPO LIFR/VLIFR IN FG AT THE
I-35 SITES. THERE IS SOME UNCERTAINTY ON DURATION OF FG AT KAUS
AND KSAT DUE TO DRAINAGE FLOW OFF THE HILLS. BR/FG LIFTS BY LATE
MORNING TO BE REPLACED BY STRATUS WITH MVFR CIGS IN THE AFTERNOON
AS LOWER LEVEL MOISTURE INCREASES. CIGS LOWER TUESDAY NIGHT TO IFR
AS AIRMASS COOLS. ISOLD/SCT SHRA/TSRA ARE POSSIBLE EAST OF KPEZ TO
KHDO TO KERV TO KAQO LINE TUESDAY AND TUESDAY NIGHT. FOR NOW...
WILL NOT MENTION IN THE TAFS...ALTHOUGH...MONITOR RADAR/MODEL
TRENDS FOR POSSIBLE LATER MENTION. VARIABLE WINDS OF 5 KTS OR LESS
TONIGHT BECOME S TO SE 5 TO 15 KTS ON TUESDAY.
PREV DISCUSSION... /ISSUED 945 PM CST MON DEC 21 2015/
UPDATE...
WE ARE BEGINNING TO SEE FOG FORM ACROSS THE REGION. SOME PLACES
HAVE VISIBILITY DOWN TO A QUARTER OF A MILE. HAVE UPDATED THE
FORECAST TO INCLUDE PATCHY DENSE FOG ALONG AND SOUTH OF
I-35/HWY90. AT THIS TIME WE THINK LOW VISIBILITY WILL NOT BE
WIDESPREAD...SO WE WILL HOLD OFF ISSUING ADVISORY.
HOWEVER...CONDITIONS MAY DETERIORATE OVER THE NEXT FEW HOURS.
STILL A CHANCE DRIER AIR WILL MOVE FARTHER SOUTH AND EAST.
PREV DISCUSSION... /ISSUED 616 PM CST MON DEC 21 2015/
AVIATION...
A WEAK COLD FRONT WILL SAG SOUTHEAST FROM THE HILL COUNTRY ACROSS
THE ESCARPMENT THIS EVENING AND STALL OUT INLAND FROM THE COASTAL
PLAINS. EVEN THOUGH DRIER AIR FILTERS IN BEHIND THE FRONT...
EXPECT MOIST AIR AT THE SURFACE TO RETURN BY MORNING AND MENTIONED
IFR/MVFR VSBYS IN BR IN THE TAFS. SOUTHERLY WINDS STRENGTHEN ON
TUESDAY AHEAD OF ANOTHER FRONT AND UPPER LEVEL TROUGH. LOWER LEVEL
MOISTURE INCREASES WITH STRATUS AND MVFR CIGS DEVELOPING DURING
THE DAY MAINLY AT THE I-35 TAF SITES. ISOLD/SCT SHRA/TSRA ARE
POSSIBLE ALONG/EAST OF I-35 TUESDAY INTO TUESDAY NIGHT. FOR
NOW...WILL NOT MENTION IN THE TAFS AND MONITOR RADAR/MODEL TRENDS
FOR POSSIBLE LATER MENTION. VARIABLE WINDS 5 KTS OR LESS TONIGHT
BECOME S TO SE 5 TO 15 KTS ON TUESDAY.
PREV DISCUSSION... /ISSUED 343 PM CST MON DEC 21 2015/
SHORT TERM (TONIGHT THROUGH TUESDAY NIGHT)...
A COLD FRONT IS CURRENTLY LOCATED ALONG A LLANO TO KERRVILLE TO
NEAR ROCKSPRINGS LINE LATE THIS AFTERNOON. COOLING BEHIND THE
BOUNDARY HAS BEEN OFFSET WITH DOWNSLOPING WINDS. THERE HAS BEEN
SOME DRYING BEHIND THE FRONT WITH DEW POINTS IN THE 40S BEHIND THE
FRONT COMPARED TO 50S AND 60S AHEAD OF THE FRONT. THIS COLD FRONT
IS FORECAST TO CONTINUE A SLOW EASTWARD MOVEMENT TONIGHT...BUT
SHOULD SLOW/STALL IN THE COASTAL PLAINS TOWARD SUNRISE TUESDAY. WE
COULD SEE SOME PATCHY FOG FOR AREAS EAST OF THE COLD FRONT...AND
WE/LL MENTION THIS IN THE FORECAST FOR TONIGHT.
ON TUESDAY...SOUTHERLY SLOW QUICKLY RETURNS TO THE REGION...
ALLOWING AN INCREASE IN MOISTURE ACROSS ALL AREAS. MEANWHILE...
WE/LL SEE AN INCREASING SOUTHWEST FLOW ALOFT OVER TEXAS. THE SHORT
RANGE MODELS SHOW ONE SHORTWAVE TO OUR SOUTH WITH ANOTHER
SHORTWAVE WELL TO OUR NORTHWEST. WITH AN ACTIVE SOUTHWEST FLOW
ALOFT AND DAYTIME HEATING...WE EXPECT ISOLATED TO SCATTERED
AFTERNOON CONVECTION FOR AREAS ALONG AND EAST OF THE I-35
CORRIDOR. CAN/T COMPLETELY RULE OUT A STRONG TO POSSIBLY SEVERE
STORM OR TWO...BUT IT CONTINUES TO LOOK LIKE THE BETTER LIFT WILL
REMAIN NORTH OF OUR REGION. THE MAIN CONCERN WITH ANY STORMS THAT
MANAGE TO DEVELOP WILL BE GUSTY WINDS AND HAIL.
LONG TERM (WEDNESDAY THROUGH MONDAY)...
A PACIFIC COLD FRONT IS SET TO MOVE ACROSS SOUTH CENTRAL TEXAS ON
WEDNESDAY...BRINGING DRIER AIR AND SOME GUSTY NORTHWEST WINDS TO
ALL AREAS. TEMPERATURES WILL STILL REMAIN ABOVE NORMAL ON
WEDNESDAY AS DOWNSLOPE WINDS AND DRY AIR ALLOW ANOTHER DAY OF
HIGHS IN THE 70S. ON THURSDAY...THE MODELS SHOW A MORE NORTHERN
STREAM COLD FRONT MOVING INTO WESTERN AND NORTHERN TEXAS DURING
THE MORNING HOURS. THIS BOUNDARY MAY BE STRONG ENOUGH TO REACH THE
WESTERN HILL COUNTRY...BUT TEMPERATURES ARE STILL EXPECTED TO
REMAIN ABOVE NORMAL. SOUTHERLY FLOW IN THE LOW-LEVELS QUICKLY
RETURNS THURSDAY NIGHT...BRINGING AN INCREASE IN MOISTURE AND
CLOUD COVER TO ALL AREAS. SOME LIGHT SHOWERS ARE POSSIBLE ALONG
AND EAST OF THE I-35 CORRIDOR...WITH RAINFALL AMOUNTS EXPECTED TO
REMAIN RATHER LOW.
THE FORECAST FOR LATE THIS WEEK INTO EARLY NEXT WEEK CONTINUES TO
REMAIN HIGHLY UNCERTAIN. MODEL RUN TO RUN CONSISTENCY HAS BEEN
POOR TO SAY THE LEAST. THE MODELS SHOW AN UPPER TROUGH DROPPING
SOUTH INTO THE GREAT BASIN REGION ON FRIDAY...THEN DEVELOP THE
TROUGH INTO A CLOSED LOW OVER THE DESERT SOUTHWEST OR NORTHERN
MEXICO LATE SATURDAY INTO EARLY SUNDAY. THE LOW IS THEN FORECAST
TO GRADUALLY MOVE EASTWARD INTO THE SOUTHERN U.S. PLAINS EARLY
NEXT WEEK...WITH THE TRACK OF THE LOW REMAINING HIGHLY UNCERTAIN.
FOR NOW...WE/LL BEGIN TO SHOW AN INCREASE IN RAIN CHANCES ACROSS
ALL AREAS...EXCEPT THE RIO GRANDE PLAINS ON FRIDAY. RAIN CHANCES
CONTINUE TO INCREASE ON SATURDAY WITH AN ACTIVE SOUTHWEST FLOW
ALOFT AND WELL ABOVE NORMAL MOISTURE IN PLACE. A STRONG COLD FRONT
IS THEN SET TO MOVE IN EITHER LATE SATURDAY OR EARLY SUNDAY...
BRINGING COOLER TEMPERATURES AND A DOWNWARD TREND IN PRECIPITATION
CHANCES. AS MENTIONED ABOVE...THE FORECAST LATE THIS WEEK INTO
EARLY NEXT WEEK REMAINS UNCERTAIN. STANDARD DEVIATIONS IN THE 4 TO
8 RANGE OBSERVED IN THE GFS MOS ENSEMBLE NUMBERS INDICATE THE
AMOUNT OF UNCERTAINTY IN THIS FORECAST.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 74 50 76 61 78 / 10 0 20 30 10
AUSTIN BERGSTROM INTL AIRPORT 73 46 76 62 78 / 10 0 20 30 10
NEW BRAUNFELS MUNI AIRPORT 75 50 77 61 80 / 10 0 20 30 10
BURNET MUNI AIRPORT 72 46 73 56 74 / 10 0 10 30 10
DEL RIO INTL AIRPORT 73 46 75 51 78 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 75 46 74 60 76 / 10 0 20 30 10
HONDO MUNI AIRPORT 72 47 76 56 78 / 0 0 10 10 -
SAN MARCOS MUNI AIRPORT 73 49 75 61 77 / 10 0 20 30 10
LA GRANGE - FAYETTE REGIONAL 76 53 77 65 78 / 20 - 20 40 20
SAN ANTONIO INTL AIRPORT 74 51 76 62 79 / 10 0 10 20 10
STINSON MUNI AIRPORT 75 52 77 62 79 / 10 0 10 20 10
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
DENSE FOG ADVISORY UNTIL 10 AM CST TUESDAY FOR THE FOLLOWING
COUNTIES: ATASCOSA...BASTROP...BEXAR...CALDWELL...DE WITT...
DIMMIT...FAYETTE...FRIO...GONZALES...GUADALUPE...KARNES...KINNEY...
LAVACA...LEE...MAVERICK...MEDINA...UVALDE...WILSON...ZAVALA.
&&
$$
MESOSCALE/AVIATION...TB3
SYNOPTIC/GRIDS...ALLEN
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
932 PM CST WED DEC 23 2015
.UPDATE...
LINE OF SHOWERS ALONG THE STRONG COLD FRONT BUT NO THUNDER
EXPECTED ANYMORE AS INSTABILITY LESSENING. A BRIEF PERIOD OF
LIGHT RAIN/SNOW MAINLY SOUTH CENTRAL AND TOWARD FOND DU LAC BEFORE
THE PRECIPITATION ENDS AND LIFTS NORTHEAST. NO ACCUMULATIONS
EXPECTED.
WIND ADVISORY MARGINAL...BUT STILL SOME 45 TO 48 KNOT GUSTS...ON
THE HRRR EXPERIMENTAL INTO THE EARLY MORNING HOURS SO WILL
CONTINUE.
&&
.AVIATION/06Z TAFS/...
THE BRIEF VFR DRY SLOT OVER THE SOUTHEAST WILL FILL WITH MVFR
CIGS...WITH IFR CIGS OVER PORTIONS OF SOUTH CENTRAL WISCONSIN.
VFR CONDITIONS WILL EVENTUALLY RETURN THURSDAY AS COLDER/DRIER
AIR WORKS INTO THE AREA BEHIND A DEPARTING STRONG MOVING ACROSS
EASTERN LAKE SUPERIOR.
AS COLDER AIR MOVES IN...AN AREA OF RAIN/SNOW WILL CLIP THE
NORTHWEST HALF OF THE FORECAST AREA UNTIL JUST AFTER MIDNIGHT.
LITTLE TO NO SNOW ACCUMULATION IS EXPECTED.
STRONG SOUTHWEST TO WEST WINDS EXPECTED BEHIND DEPARTING LOW
PRESSURE...WITH PEAK GUSTS OF 35 TO 45 KNOTS LIKELY THROUGH THE
EARLY MORNING HOURS.
&&
.MARINE...
GALE WARNINGS ARE IN EFFECT INTO MID MORNING THURSDAY...AS STRONG
LOW PRESSURE MOVES ACROSS THE EASTERN LAKE SUPERIOR AREA. WILL
BE QUITE WINDY THROUGH THE NIGHT...WITH GUSTS OF 40 TO 45 KNOTS
POSSIBLE.
MAY NEED A SMALL CRAFT ADVISORY FROM MID MORNING THURSDAY INTO INTO
THE AFTERNOON AS WINDS SLOWLY EASE.
WAVES OF 4 TO 8 FEET ARE EXPECTED TONIGHT...SLOWLY SUBSIDING THROUGH
THE DAY THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 352 PM CST WED DEC 23 2015/
TONIGHT AND THURSDAY...FORECAST CONFIDENCE...HIGH
AREA OF SHOWERS AND STORMS IS CURRENTLY APPROACHING FROM THE
SOUTHWEST THIS AFTERNOON. THESE SHOWERS/STORMS ARE EXPECTED TO LIFT
THROUGH THE FORECAST AREA FROM LATE AFTERNOON INTO MID-EVENING.
SPC IS MAINTAINING A SLIGHT RISK FOR SEVERE STORMS IN
THE FAR SOUTHERN FORECAST AREA...WITH A MARGINAL RISK ELSEWHERE.
STILL THINK MAIN THREAT IS FOR STRONG WINDS...THOUGH AN ISOLATED
TORNADO IS NOT OUT OF THE QUESTION.
WHILE THE STORMS ARE EXITING...A DEFORMATION BAND OF RAIN/SNOW WILL
AFFECT THE NORTHWEST HALF OF THE FORECAST AREA FOR THE LATE EVENING
HOURS...WINDING DOWN JUST PAST MIDNIGHT. LITTLE OR NO SNOW
ACCUMULATION IS EXPECTED. IT SHOULD BE THEN DRY FOR THE REST OF THE
NIGHT INTO THURSDAY MORNING...WITH A FEW SNOW FLAKES POSSIBLE IN THE
SOUTHWEST FORECAST AREA THURSDAY AFTERNOON AS A SHORTWAVE MOVES
THROUGH.
VERY WINDY CONDITIONS WILL DEVELOP BEHIND THE DEPARTING LOW AND COLD
FRONT BY MID/LATE EVENING. GUSTS OF 40 TO 50 MPH ARE LIKELY. HAVE
MAINTAINED THE WIND ADVISORY AS IS...EXCEPT LAFAYETTE COUNTY WAS
ADDED.
THURSDAY NIGHT THROUGH FRIDAY...FORECAST CONFIDENCE...HIGH
HIGH PRESSURE WILL MOVE ACROSS THE REGION ON FRIDAY BRINGING QUIET
WEATHER. A 130KT UPPER JET WILL BE OVERHEAD IN SOUTHWEST FLOW
CONTINUING THE MILD TEMPERATURES.
SATURDAY AND SUNDAY...FORECAST CONFIDENCE...MEDIUM
NEXT CHANCE FOR PRECIP IS SATURDAY. THE UPPER JET STRENGTHENS OVER
SOUTHEAST CANADA PUTTING S WI IN THE RIGHT ENTRANCE REGION. MID
LEVEL FRONTOGENESIS WILL BE MOVING ACROSS CENTRAL AND SOUTHERN WI
COMBINED WITH LOW TO MID LEVEL WARM AIR ADVECTION MOVING FROM IOWA
INTO SOUTHERN WI BRINGING A CHANCE FOR PRECIP STARTING EARLY
SATURDAY. THERE COULD BE A RAIN/SNOW MIX IN THE NORTHWEST CWA IN
THE MORNING BEFORE A CHANCE OF RAIN ACROSS ALL OF SOUTHERN WI
DURING THE DAY. IN ADDITION...RAIN ASSOCIATED WITH LOW PRESSURE
APPROACHING FROM THE SOUTH MAY REACH INTO SOUTHERN WI. COULD SEE
SOME FLAKES SATURDAY NIGHT IN THE NORTHWEST CWA ON THE BACKSIDE OF
THIS SYSTEM.
HIGH PRESSURE WILL THEN WORK ITS WAY ACROSS THE REGION ON SUNDAY
BRINGING DRY CONDITIONS. TEMPERATURES WILL COOL SLIGHTLY STARTING
ON SUNDAY AS THE MID LEVEL FLOW BECOMES MORE WESTERLY AND A PAIR
OF MID LEVEL LOWS MOVE THROUGH.
MONDAY THROUGH WEDNESDAY...FORECAST CONFIDENCE...LOW
MODELS DIVERGE AT THIS POINT WITH THE GFS SHOWING APPROACHING LOW
PRESSURE WITH PRECIP STARTING ON MONDAY NIGHT WHILE THE ECMWF IS
SHOWER BRINGING THIS SYSTEM THROUGH ON TUESDAY. THERE IS
UNCERTAINTY WITH PRECIP TYPE IN THE SOUTHEAST WI BUT SNOW IS
POSSIBLE NORTH AND WEST OF MADISON AND MILWAUKEE. THE TIGHT
PRESSURE GRADIENT WITH THIS LOW WILL BRING STRONG WINDS BUT THE
TIMING IS STILL UNCERTAIN.
WEEK 2 FORECAST FROM CPC INDICATES A 50 PERCENT CHANCE OF ABOVE
AVERAGE TEMPERATURES FROM DEC 31 - JAN 6.
AVIATION/00Z TAFS/...
LOW CIGS WILL GENERALLY PERSIST INTO TONIGHT...THOUGH THERE WILL
WILL PROBABLY BE BRIEF VFR BREAKS. WIDESPREAD VFR WILL EVENTUALLY
DEVELOP LATER TONIGHT INTO THURSDAY AS COLDER/DRIER AIR WORKS INTO
THE AREA.
NEXT ROUND OF SHOWERS IS APPROACHING FROM THE SOUTHWEST THIS
AFTERNOON. THIS AREA OF SHOWERS WILL PROBABLY CONTAIN A FEW
THUNDERSTORMS...WITH A SEVERE STORM OR TWO NOT OUT OF THE QUESTION.
THESE SHOWERS/STORMS WILL LIFT THROUGH THE FORECAST AREA FROM LATE
AFTERNOON TO EARLY/MID EVENING.
AN AREA OF RAIN/SNOW WILL THEN CLIP THE NORTHWEST HALF OF THE
FORECAST AREA FROM MID-EVENING UNTIL JUST AFTER MIDNIGHT. LITTLE TO
NO SNOW ACCUMULATION IS EXPECTED.
SOUTHWEST TO WEST WINDS WILL INCREASE BEHIND DEPARTING LOW
PRESSURE THIS EVENING...WITH PEAK GUSTS OF 35 TO 45 KNOTS LIKELY FROM
LATE EVENING INTO THE EARLY MORNING HOURS.
MARINE...
DECIDED TO CANCEL THE DENSE FOG ADVISORY BASED ON WEBCAMS AND THE
FACT THAT WINDS HAVE TURNED SOUTHERLY.
EXTENDED THE GALE WARNING INTO MID MORNING THURSDAY...AS IT LOOKS
LIKE THE STRONGER GUSTS WILL HANG ON A BIT LONGER. WILL TURN QUITE
WIND LATE EVENING INTO THE NIGHT...WITH GUSTS OF 40 TO 45 KNOTS
POSSIBLE BEHIND A STRONG COLD FRONT AND DEPARTING LOW PRESSURE.
MAY NEED A SMALL CRAFT ADVISORY FROM MID MORNING THURSDAY INTO INTO
THE AFTERNOON AS WINDS SLOWLY EASE.
WAVES OF 4 TO 8 FEET ARE EXPECTED TONIGHT...SLOWLY SUBSIDING THROUGH
THE DAY THURSDAY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND ADVISORY UNTIL 6 AM CST THURSDAY FOR WIZ046-047-051-052-
057>060-063>072.
LM...GALE WARNING UNTIL 9 AM CST THURSDAY FOR LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/THURSDAY AND AVIATION/MARINE...DDV
THURSDAY NIGHT THROUGH WEDNESDAY...MARQUARDT
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
611 PM CST WED DEC 23 2015
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
AND NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 550 PM CST WED DEC 23 2015
MADE SOME EARLIER ADJUSTMENTS TO POPS/WX TO ACCOUNT FOR DRY
SLOTTING THAT WAS OCCURRING. SHOWERS AND SCT TSTMS WILL FILL
BACK IN OVER THE REGION IN ASSOCIATION WITH THE ARRIVAL OF THE
POTENT NEGATIVELY-TILTED S/W TROF...SFC LOW AND COLD FRONT THIS
EVG. SBCAPE/MUCAPE HAS BEEN WANING THE PAST FEW HOURS...SO NOT
CONVINCED THAT WE WILL HAVE ANY SIGNIFICANT PROBLEMS WITH THE
CONVECTION LIFTING NE OUT OF NE IA/NW IL. NEVERTHELESS...WILL
KEEP A CLOSE EYE ON IT. SUSPECT THAT RAIN WILL RAPIDLY CHANGE TO
SLEET/SNOW OVER OUR FAR WESTERN COUNTIES BETWEEN 03Z-05Z...WITH
A PERIOD OF MODERATE SNOW EXPECTED OVER FAR NC WI DURING THE
LATE EVENING/EARLY OVERNIGHT HOURS. THUS...THE WINTER WX ADVISORY
FOR VILAS/ONEIDA COUNTIES LOOKS ON TARGET. GUSTY WINDS SHOULD
QUICKLY INCREASE LATE THIS EVG...IN THE WAKE OF THE COLD FRONTAL
PASSAGE. ADVISORY CRITERIA WINDS LOOK LIKE A GOOD BET...AT LEAST
IN THE FOX VALLEY/LKSHR AREAS. NOT SURE THAT WE WILL REACH
WARNING CRITERIA FOR DOOR COUNTY...BUT NOT PLANNING ANY CHANGES
TO THE HIGH WIND WARNING AT THIS TIME.
&&
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 309 PM CST WED DEC 23 2015
PLENTY OF FORECAST CHALLENGES NEXT 24 HOURS CONCERNING WITH GUST
POTENTIAL AND AMOUNT OF RAINFALL AND RAINFALL RATES WHICH MAY
IMPACT ANY LINGERING RIVER FLOOD PROBLEMS AS WELL AS PRODUCE ANY
SMALL STREAM URBAN FLOODING ISSUES. SEE THE HYDROLOGY SECTION
BELOW FOR THE LATEST DETAIL ON FLOODING ISSUES. OTHER ISSUES
CONCERN CHANGE OVER TO SNOW TONIGHT.
A STRONG SHORT WAVE LIFTS NORTHEAST OVER THE GREAT LAKES REGION
THROUGH TONIGHT. AN ASSOCIATED SURFACE LOW WILL TRACK FROM IOWA
LATE THIS AFTERNOON TO CENTRAL UPPER MICHIGAN AROUND MIDNIGHT AND
DEEPEN. THE LOW WILL ALSO A DRAG WARM FRONT OVER NORTHEAST
WISCONSIN THIS AFTERNOON INTO THIS EVENING. MILDER AIR SPREADING
INTO EAST CENTRAL AND FAR NORTHEAST WISCONSIN WILL ALLOW A VERY
MILD AIR MASS WITH POSSIBLE RECORD HIGHS TO INVADE THE AREA.
HIGHEST TOTAL TOTALS NUMBERS IN THE LOWER 50S MID EVENING AS PER
GRB BUFKIT DATA. THIS WILL ALSO RESULT IN A MORE UNSTABLE AIR
MASS AND MAY PROMOTE BETTER MIXING OF STRONG WINDS TO THE
SURFACE...ESPECIALLY WITH ANY CONVECTION. HRRR PROGGED DEVELOPMENT
OF THIS CONVECTION OF CONCERN ALONG AND AHEAD OF THE FRONT OVER
NORTHERN MO AND SOUTHERN IOWA AND SO FAR IS VERIFYING. THIS NEXT
ROUND IS PROGGED TO SWEEP OVER THE AREA THIS EVENING.
PROBLEM 2 WITH THE WINDS OCCUR LATE TONIGHT AS THE DEEPENING LOW
PRESSURE DEPARTS NORTHEAST AND LEAVES A STRONG PRESSURE GRADIENT
OVER MUCH OF THE STATE. A STRONG PRESSURE CHANGE COUPLET SLIDES
OVER NORTHEAST WISCONSIN IN THE WAKE OF THE SURFACE LOW. WILL
CONTINUE WITH THE WIND ADVISORY AND WILL ISSUE FOR DOOR DUE TO THE
WESTERLY COMPONENT. ITS POSSIBLE THE HIGH WIND ADVISORIES AND
WARNINGS MAY NEED TO BE EXPANDED DEPENDING ON THE LOW PRESSURE
TRACK.
PCPN TYPE INITIALLY NOT AN ISSUE BUT COULD SEE SOME HAIL OR
GRAUPEL WITH ANY CONVECTION THIS EVENING. LATER EVENING INTO THE
MORNING...COLDER AIR POURING IN WILL CHANGE THE PCPN TYPE TO
SNOW. WHILE SNOW RANGES MOSTLY IN THE 2-4 RANGES FOR NC WI...THE
SNOW WIND COMBO WARRANTS AN ADVISORY LATER TONIGHT. RADAR SOUTHERN
LOOP SUGGESTS REACHING NC WI AND CHANGEOVER AND ISSUE. BUT DID
NOTICE SOME THUNDER WITH THE SURFACE LOW OVER IOWA.
SYSTEM GRADUALLY DEPARTS THURSDAY WITH DIMINISHING WINDS IN THE
MORNING. TEMPERATURES NEAR STEADY ON THURSDAY.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 309 PM CST WED DEC 23 2015
AMPLIFIED MEAN FLOW TO REMAIN INTACT THRU THE END OF THE WORK WEEK
WITH AN ERN PACIFIC UPR RDG...WRN CONUS UPR TROF AND BERMUDA UPR
RDG. THE UPR TROF IS FCST TO CLOSE OFF INTO AN UPR LOW OVER WEST
TX THIS WEEKEND BEFORE LIFTING NE INTO THE GREAT LAKES EARLY NEXT
WEEK. PCPN CHCS WL BE FOCUSED FRI NGT/SAT ASSOCIATED WITH A TIGHT
BAROCLINIC ZONE/JET ENERGY AND MON NGT/TUE WITH THE UPR LOW/
ASSOCIATED SFC LOW. PCPN TYPE ISSUES WL ALSO BE A PROBLEM WITH
BOTH OF THESE SYSTEMS AS TEMPS FLUCTUATE BELOW FREEZING AT NGT AND
RISE ABOVE FREEZING IN PLACES DURING THE DAY. THERE IS SNOW
ACCUMULATION POTENTIAL FOR CNTRL/NRN WI FRI NGT AND OVER THE
ENTIRE AREA MON NGT/TUE.
A WEAK AREA OF HI PRES IS FCST TO APPROACH SRN SECTIONS OF THE
GREAT LAKES THU NGT AND SHOULD KEEP THE FCST AREA DRY. IT MAY TAKE
MOST OF THE NGT TO TRY AND SCOUR OUT LINGERING LOW/MID-LEVEL
MOISTURE...THUS PARTLY TO MOSTLY CLOUDY SKIES SHOULD SUFFICE. MIN
TEMPS TO RANGE FROM THE MID TO UPR TEENS NORTH...LWR 20S CNTRL...
AND MID TO UPR 20S E-CNTRL WI. THESE DRY CONDITIONS ARE EXPECTED
TO PERSIST THRU CHRISTMAS DAY AS THE SFC HI SLIDES EAST TOWARD THE
ERN GREAT LAKES. UNDER PARTLY CLOUDY SKIES AND RELATIVELY LIGHT
WINDS...LOOK FOR MAX TEMPS TO REACH THE LWR TO MID 30S NORTH...
MID TO UPR 30S SOUTH.
FCST CONFIDENCE DROPS RATHER QUICKLY LATE FRI NGT INTO SAT AS AN
UPR TROF DEEPENS OVER THE ROCKIES...INDIVIDUAL SHORTWAVES EJECT
OUT OF THIS TROF NEWD THRU THE CNTRL CONUS...A STALLED FRONTAL
BOUNDARY TO OUR SOUTH BECOMES MORE ACTIVE AND GULF MOISTURE LIFTS
NORTH ALONG THIS FRONTAL BOUNDARY TOWARD THE GREAT LAKES. MODELS
BRING THE LEADING EDGE OF PCPN INTO NE WI LATE FRI NGT WHEN TEMPS
WL BE COLD ENUF TO ALLOW PCPN TO FALL AS ALL SNOW. THE ISSUES FOR
SAT ARE WHERE THE HIGHEST QPF WL FALL AND WHAT THE PCPN TYPE WL
BE. THIS IS WHERE THE MODELS DIFFER AS THE GFS/ECMWF FOCUS THE
HEAVIER PCPN TO THE NORTH AND ALLOW FOR WARMER AIR TO LIFT FARTHER
NORTH INTO WI...THUS A MIXED PCPN EVENT FOR CNTRL/E-CNTRL WI WITH
SNOW NORTH. THE GEM IS FARTHEST SOUTH WITH THE HEAVIER PCPN (SRN
WI) AND COOLER AIR...THUS KEEPING ALL OUR PCPN AS ALL SNOW. THE
BETTER FRONTOGENETICAL FORCING SIGNAL AND LOCATION OF THE BEST
LIFT FROM THE RIGHT ENTRANCE REGION OF THE UPR JET FAVOR NRN WI
WITH THE HIGHER QPF...THUS WL CONT THE MENTION OF SNOW NORTH AND
SNOW BECOMING MIXED WITH RAIN FOR CNTRL/E-CNTRL WI. POTENTIAL SNOW
ACCUMULATION OF 3-5" IS POSSIBLE OVER THE NORTH FRI NGT INTO
SAT...BUT ANY WAVERING ON THE STRONGER LIFT/FORCING COUDL ALTER
THESE VALUES.
AS THE STRONGER DYNAMICS SHIFT TO THE EAST SAT NGT...MODELS
INDICATE CAA TO TAKE OVER ACROSS WI...THUS ANY LINGERING RAIN OVER
CNTRL OR E-CNTRL WI WL TRANSITION TO ALL SNOW. DO NOT ANTICIPATE
MUCH (IF ANY) ADDITIONAL ACCUMULATION SAT NGT AS MOST OF THE
MOISTURE TO HAVE BEEN SHUNTED EAST. A STRONG AREA OF HI PRES IS
FCST TO BUILD ACROSS THE UPR MS VALLEY ON SUNDAY AND SEND ENUF DRY
AIR INTO WI TO ALLOW SKIES TO BECOME AT LEAST PARTLY CLOUDY.
DESPITE THE CAA AND NORTH WINDS AT 5 TO 15 MPH...MAX TEMPS ARE
FCST TO REMAIN ABOVE NORMAL ON SUNDAY BY AROUND 5 DEGS (MID 20S
N-CNTRL TO LWR 30S E-CNTRL WI).
THE CORE OF THIS STRONG HI PRES IS PROGGED TO MOVE ACROSS WRN
ONTARIO SUNDAY NGT AND VEER THE WINDS TO THE NE. WL HAVE TO WATCH
FOR POTENTIAL OF LK EFFECT SNOW SHWRS FROM LK MI AS TEMPS/DELTA-T
VALUES WOULD SUPPORT THE DEVELOPMENT OF LIGHT SNOW. ONE NEGATIVE
IS THAT THE WINDS CONT TO VEER THRU THE NGT (FROM NORTH TO
E-NE)...THUS IT MAY PROVE DIFFICULT FOR SNOW BANDS TO FOCUS ON ANY
ONE PARTICULAR AREA. OTHERWISE...THE OTHER BIG STORY WL BE THE
APPROACH OF ANOTHER STRONG AREA OF LOW PRES/CLOSED UPR LOW INTO
THE MID-MS VALLEY ON MON. LATEST THINKING IS THAT THERE WL BE ENUF
DRY AIR ON GUSTY EAST WINDS FROM ONTARIO HI PRES TO DELAY THE
ONSET OF ANY PCPN INTO NE WI ON MON. HAVE REDUCED POPS AND WOULD
EXPECT ALMOST A COMPLETELY DRY DAY FOR MON WITH MAX TEMPS IN THE
UPR 20S TO LWR 30S.
MODELS CONT TO DIFFER WITH THE TIMING/EVENTUAL TRACK OF THIS
STRONG SYSTEM MON NGT INTO TUE WITH THE GFS/GEM FAVORING A
QUICKER/FARTHER EAST TRACK VERSUS THE SLOWER/FARTHER WEST TRACK OF
THE ECMWF. THE GFS/GEM SOLUTION WOULD PROVIDE A QUICK-HITTING SNOW
EVENT FOR MAINLY THE SE HALF OF WI MON NGT BEFORE PULLING AWAY ON
TUE. THE ECMWF SOLUTION WOULD BRING A SWATH OF SNOW ACROSS ALL
OF NE WI MON NGT BEFORE MIXING IN RAIN OVER CNTRL/E-CNTRL WI ON
TUE WITH ADDITIONAL SNOWS FOR NRN WI. IF THE ECMWF SOLUTION
PREVAILS...WE WOULD BE LOOKING AT HEADLINES FOR SNOW...HOWEVER
THERE IS TOO MUCH UNCERTAINTY YET SO HAVE FOLLOWED A MODEL BLEND
FOR NOW WITH HIGHER CHC POPS IN THE FCST FOR BOTH MON NGT AND TUE.
EVEN GOING INTO WED...THERE IS MODEL DISAGREEMENT WITH RESPECT TO
THE TRACK OF THE SECONDARY/WEAKER UPR LOW THAT WOULD LIFT NE INTO
THE REGION. SINCE MODELS ARE INCONSISTENT WITH THIS
FEATURE...PREFER TO KEEP THE FCST DRY FOR NOW...BUT WOULD EXPECT
SOME SMALL POPS TO BE ADDED AS WE GET CLOSER TO WED.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 550 PM CST WED DEC 23 2015
AFTER A BRIEF LULL IN THE PCPN DUE TO A DRY SLOT...SHOWERS AND
SCT TSTMS ARE EXPECTED TO REDEVELOP AS A STRONG UPPER LEVEL
DISTURBANCE...SURFACE LOW AND COLD FRONT MOVE THROUGH THIS
EVG. TSTMS SHOULD BE MOST LIKELY IN EC WI...SO PUT TEMPO GROUPS
IN THE GRB/ATW/MTW TAF SITES. AREAS OF FOG WILL AFFECT MUCH OF
NC/C/NE WI THIS EVG UNTIL THE COLD FRONT MOVES THROUGH. RAIN IS
EXPECTED TO CHANGE TO SLEET/SNOW OVER NC/C WI BETWEEN 03Z-05Z/THU
AND PERIOD OF MODERATE SNOWFALL MAY OCCUR IN NC WI...INCLUDING
THE RHI TAF SITE...DURING THE LATE EVG/ EARLY OVERNIGHT HOURS.
LINGERING RAIN/SNOW SHOULD TAPER OFF MOST AREAS BY 09Z-10Z/THU...
WITH CONDITIONS THEN IMPROVING TO MVFR/VFR.
WILL KEEP LLWS IN THE GRB/ATW/MTW TAFS THROUGH LATE EVG...
UNTIL THE COLD FRONTAL PASSAGE OCCURS. STRONG GUSTY SW-W WINDS
WILL DEVELOP IN THE WAKE OF THE FRONT...AND CONTINUE THROUGH
THURSDAY MORNING BEFORE DIMINISHING. GUSTS AS HIGH AS 40 KTS
ARE POSSIBLE IN THE FOX VALLEY/LKSHR AREAS.
&&
.MARINE...
ISSUED AT 309 PM CST WED DEC 23 2015
HIGH-END GALES ARE STILL LIKELY WITH THIS STORM....BUT WILL
MENTION STORM FORCE WIND GUSTS. IN ADDITION WILL ALSO MENTION A
PERIOD OF FOG THOUGH THE EVENING HOURS.
&&
.HYDROLOGY...
ISSUED AT 309 PM CST WED DEC 23 2015
MOST RIVERS HAVE RECOVERED FROM THE HEAVY RAINS OVER A WEEK
AGO...EXCEPT FOR THE LOW LYING AREAS ALONG THE WOLF RIVER SOUTH OF
SHAWANO TO LAKE POYGAN. WITH THIS RAINFALL EXPECTED TO BE IN A
SHORTER TIME FRAME...AN INCH OF RAIN COULD PRODUCE ENOUGH RUN OFF
FOR SOME MINOR URBAN SMALL STREAM FLOODING. THIS WOLF RIVER LEVELS
MAY HOLD STEADY FOR A FEW MORE DAYS WITH THIS ADDITIONAL RAINFALL.
BUT LATEST RADAR TRENDS SUGGEST SOME DRY SLOTTING AS AN AREA OF
ELEVATED CONVECTION IS SWEEPING NORTHEAST OF THE AREA...WITH THE
NEXT ROUND OF CONVECTION APPROACHING FROM IOWA. AS A RESULT RAIN
AMOUNTS TO BE LESS ROUGHLY FORM 0.30 TO 0.50. SEE
WEATHER.GOV/AHPS FOR AVAILABLE FORECASTS FOR NORTHEAST WISCONSIN
RIVERS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 PM THIS EVENING TO NOON CST THURSDAY FOR
WIZ020-021-031-037>040-045-048>050-073-074.
HIGH WIND WARNING FROM 10 PM THIS EVENING TO NOON CST THURSDAY
FOR WIZ022.
WINTER WEATHER ADVISORY UNTIL 4 AM CST THURSDAY FOR WIZ005-010.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....TDH
LONG TERM......AK
AVIATION.......KIECKBUSCH
MARINE.........TDH
HYDROLOGY......TDH
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
256 PM MST TUE DEC 22 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 214 PM MST TUE DEC 22 2015
PRIMARY FORECAST CONCERN FOR THE SHORT TERM IS THE POTENTIAL FOR
SNOWFALL ACROSS THE EXTREME SE WYOMING PLAINS EXTENDING INTO THE
SOUTHERN NEBRASKA PANHANDLE THIS EVENING AND TONIGHT. EVERYTHING
ELSE APPEARS ON TRACK...WITH CURRENT KCYS RADAR LOOP SHOWING
SNOWFALL CONTINUING OVER THE MOUNTAINS. SNOTEL OBSERVATIONS ACROSS
THE SIERRA MADRE RANGE SHOW SOME IMPRESSIVE 36 HOUR SNOW
TOTALS...WITH TWO LOCATIONS NEAR BATTLE MOUNTAIN PASS ESTIMATING
BETWEEN 34 TO 42 INCHES OF SNOW SINCE LATE SUNDAY NIGHT. MORE SNOW
IS EXPECTED TONIGHT AND WEDNESDAY...SO THESE TOTALS WILL LIKELY GO
OVER 4 FEET IN A FEW LOCATIONS. MUCH LESS SNOW WAS OBSERVED OVER
THE SNOWY RANGE WITH ONLY ONE LOCATION ABOVE ONE FOOT OF TOTAL
ACCUMULATION. WILL CONTINUE THE WINTER WEATHER ADVISORIES FOR A
FEW OF THE LOWER ELEVATIONS OF CARBON COUNTY INTO THIS EVENING
WITH SOME ADDITIONAL SNOW AND BLOWING SNOW ALONG AND SOUTH OF I80.
ATTENTION THEN SHIFTS EASTWARD TOWARDS LARAMIE...THE CHEYENNE
AREA...AND ACROSS THE SOUTHERN NE PANHANDLE ALONG I80. MODELS ARE
IN PRETTY GOOD AGREEMENT SHOWING AN AREA OF RAPID FRONTOGENESIS
THIS EVENING JUST SOUTH OF THE COLORADO BORDER. MODELS SHOW A
WEAK WAVE OF LOW PRESSURE DEVELOPING ALONG THE FRONT THIS
EVENING...WHICH IS CURRENTLY NEAR DENVER AND STRETCHES EASTWARD
OVER THE PLAINS NEAR I-70 OVER EASTERN COLORADO. THIS FEATURE
APPEARS TO BE FAST MOVING BUT POTENT...WITH EVEN THE HRRR AND NAM
SHOWING SOME MODERATE SNOW FROM THE I80 SUMMIT EASTWARD INTO
THE SOUTHERN NE PANHANDLE. TYPICALLY...GOOD MODEL AGREEMENT WOULD
INCREASE OVERALL CONFIDENCE 6 TO 12 HOURS OUT...BUT THE ISSUE IS
NO MODELS WAS SHOWING THIS FEATURE YESTERDAY. FOR NOW...INCREASED
POP TO 50 PERCENT ALONG THE I80 CORRIDOR INTO SIDNEY NEBRASKA.
WORDED FORECAST FOR OCCASIONAL SNOW AND 1 TO 2 INCHES OF SNOW
ACCUMULATION FOR NOW EVEN THOUGH THE NAM AND GEM ARE A BIT HIGHER.
WITH WESTERLY FLOW JUST OFF THE SURFACE AND RELATIVELY LOW
DEWPOINTS...CONCERNED THERE IS TOO MUCH DRY AIR TO PRODUCE MUCH
SNOWFALL. THE FRONT WILL QUICKLY PUSH SOUTH AND EAST LATE TONIGHT.
ANOTHER ROUND OF SNOW IS POSSIBLE FOR WEDNESDAY...ALTHOUGH MODELS
ARE NOT AS AGGRESSIVE AS THEY WERE YESTERDAY. ANOTHER QUICK MOVING
SHORTWAVE MOVES ACROSS WYOMING DURING THE AFTERNOON AND EVENING
HOURS...WITH SOME LIGHT SNOW ACROSS THE MOUNTAINS AND POTENTIALACROSS
THE EASTERN PLAINS. WINDS WILL ALSO BEGIN TO INCREASE AGAIN LATE
WEDNESDAY AND WEDNESDAY NIGHT AS HIGH PRESSURE NEAR THE SURFACE
BUILDS ON THE WINDWARD SIDE OF THE ROCKY MOUNTAINS. MAY NEED HIGH
WIND HEADLINES FOR THE WIND PRONE AREAS ONCE AGAIN BY EARLY
THURSDAY MORNING WITH GUSTS AROUND 55 TO 60 MPH.
OTHERWISE...BECOMING COLDER EACH DAY WITH HIGHS ON IN THE 20S TO
LOW 30S BY CHRISTMAS EVE.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 245 PM MST TUE DEC 22 2015
NEXT UPPER SYSTEM TO AFFECT THE AREA WILL BE DIGGING OVER THE
WESTERN CONUS THURSDAY NIGHT WITH SW FLOW ALOFT OVER THE CWA. SOME
SNOW SHOWERS SHOULD OCCUR OVER THE HIGHER MTNS THURSDAY NIGHT AS
MOISTURE INCREASES IN THE FLOW OVER THAT AREA. ONE BATCH OF ENERGY
EJECTS NORTHEAST ACROSS THE CWA CHRISTMAS DAY WITH LEE
CYCLOGENESIS OVER SE COLORADO. THIS SHOULD BRING AN AREA OF LIGHT
SNOW TO MUCH OF THE CWA IN THE AFTERNOON AND EVENING BODING FOR A
WHITE CHRISTMAS FOR AT LEAST PARTS OF THE CWA FOR THE 4TH TIME IN
THE LAST 5 YEARS. MEANWHILE THE MAIN ENERGY WITH THE UPPER SYSTEM
STILL PROGGED TO CUT OFF OVER ARIZONA FRIDAY NIGHT WHILE THE SNOW
ENDS OVER OUR CWA. MODELS IN PRETTY GOOD AGREEMENT IN TRACKING THE
UPPER LOW ACROSS THE SOUTHERN ROCKYS INTO THE SOUTHERN PLAINS
SATURDAY THROUGH SUNDAY WITH THE GFS A BIT FASTER. THIS KEEPS THE
CWA DRY BUT COLD COMPLIMENTS OF A COLD SFC HIGH THAT WILL SETTLE
OVER THE NORTHERN PLAINS. THE UPPER LOW THEN LIFTS NORTHEAST ON
MONDAY AND MAY BRING A GLANCING SHOT OF WRAP-AROUND LIGHT SNOW TO
THE PANHANDLE. OTHERWISE WARMING SOME MONDAY AS SFC DOWNSLOPE FLOW
SETS UP BEFORE ANOTHER UPPER SHORTWAVE PASSES BY MONDAY NIGHT
BRINGING SOME COOLER AIR AGAIN AS WELL AS SOME MTN SNOW SHOWERS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY AFTERNOON)
ISSUED AT 245 PM MST TUE DEC 22 2015
MAINLY VFR OVER ALL TERMINALS INTO EARLY THIS EVENING THEN SOME
MVFR/IFR CONDITIONS EXPECTED FOR A TIME TONIGHT ALONG A LINE FROM
KRWL TO KSNY AS A BAND OF LIGHT SNOW MAY DEVELOP. CONDITIONS
IMPROVING LATER TONIGHT IN THAT AREA. VFR AGAIN AREAWIDE
WEDNESDAY.
&&
.FIRE WEATHER...
ISSUED AT 214 PM MST TUE DEC 22 2015
NO FIRE WEATHER CONCERNS IN THE NEAR FUTURE WITH AFTERNOON
HUMIDITY VALUES WELL OUTSIDE OF CRITICAL THRESHOLDS IN ADDITION TO
SEVERAL CHANCES FOR PRECIPITATION OVER THE NEXT SEVERAL DAYS.
HEAVY MOUNTAIN SNOW IS ALREADY OCCURRING IN THE SNOWY/SIERRA
MADRES...AND IS LIKELY TO CONTINUE THROUGH THU.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 5 PM MST WEDNESDAY FOR WYZ112-114.
WINTER WEATHER ADVISORY UNTIL 5 PM MST THIS AFTERNOON FOR WYZ111.
WINTER WEATHER ADVISORY UNTIL 7 PM MST THIS EVENING FOR WYZ110.
NE...NONE.
&&
$$
SHORT TERM...TJT
LONG TERM...RE
AVIATION...RE
FIRE WEATHER...TJT
AREA FORECAST DISCUSSION
NWS NEW YORK NY
423 AM EST THU DEC 24 2015
.SYNOPSIS...
LOW PRESSURE MOVING THROUGH CANADA WILL DRAG A COLD FRONT ACROSS
THE REGION TODAY. THE FRONT WILL SLOWLY SAG SOUTH OF THE REGION
LATE TONIGHT...AND TOWARDS THE MID ATLANTIC STATES ON CHRISTMAS
AS HIGH PRESSURE BUILDS IN FROM THE NORTH. UNSETTLED WEATHER WILL
RETURN FOR THE WEEKEND AND INTO NEXT WEEK AS A SERIES OF STORM
SYSTEMS MOVE ACROSS.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BREEZY AND INCREDIBLY WARM DAY TODAY (ABOUT 30 DEGREES ABOVE
SEASONABLE.
PHASED SHORTWAVE PIVOTS FROM THE UPPER GREAT LAKES INTO QUEBEC
TODAY...WHILE DEEP TROUGHING RE-ESTABLISHES ACROSS THE WESTERN US
THROUGH TONIGHT. MEANWHILE...BERMUDA RIDGING REMAINS IN CONTROL TO
THE EAST...CONTINUING THE DEEP SW FLOW INTO THE REGION.
AT THE SURFACE...STRONG GREAT LAKES LOW PRESSURE CONTINUES TO TRACK
UP TOWARDS HUDSONS BAY TODAY...WITH ITS WEAKENING TRAILING COLD
FRONT APPROACHING THE REGION LATE TODAY INTO THIS EVENING. HIGHER
RES MODELS INDICATING POTENTIAL FOR A PRE-FRONTAL TROUGH DEVELOPING
ACROSS WESTERN PORTIONS OF THE TRI-STATE THIS AFTERNOON.
AREAS OF FOG WITH VSBY 1/2 TO 1 MILE EXPECTED TO CONTINUE THROUGH
THE MORNING ACROSS LI AND CT IN ADVECTION FOG. A GRADUAL IMPROVEMENT
IN VSBY EXPECTED THROUGH THE LATE MORNING...BUT NEARSHORE LOCATIONS
COULD HOLD WITH POOR VISIBILITIES INTO THE AFTERNOON WITH MARINE
LAYER. AWAY FROM MARINE INFLUENCE...SUCH AS NYC/NJ METRO AND
INTERIOR LOCATIONS...SHOULD SEE A MORE RAPID IMPROVEMENT IN VSBY
THIS MORNING.
HIGH-RES ENSEMBLE AND HRRR INDICATING REMNANTS OF CONVECTIVE LINE
AND ADDITIONAL SHOWER ACTIVITY DEVELOPING THIS MORNING AND
TRANSLATING FROM W TO E THROUGH EARLY AFTERNOON AS 55-60 KT LLJ
TRANSLATE EAST AHEAD OF A PRE-FRONTAL TROUGH. WITH WEAK ELEVATED
INSTABILITY AND FORCING...WILL INCLUDE A SLIGHT CHANCE OF THUNDER
THIS MORNING. THIS AFTERNOON...APPEARS LLJ FORCING AND WEAK
SURFACE TROUGH MOVES EAST. MARGINAL INSTABILITY (POTENTIALLY
SURFACE BASED ACROSS NE NJ/LOWER HUD) STILL EXISTS...BUT NOT MUCH
FORCING OR CONVERGENCE WITH THE APPROACHING COLD FRONT. SO SHOWER
POTENTIAL APPEARS TO BE LOW CHANCE TO SLIGHT...WITH LOW CONFIDENCE
ON ANY THUNDER BASED ON THE WEAK FORCING. BETTER CHANCE OF THUNDER
LOOKS TO BE SOUTH OF THE TRI-STATE. BASED ON WIND PROFILE...GUSTY
WINDS OF 40+ MPH COULD ACCOMPANY ANY HEAVY SHOWER OR TSTMS
ACTIVITY.
IN TERMS OF WINDS...950 HPA WINDS OF 35 TO 40 KT ARE EXPECTED
TODAY...BUT MIXING IS THE CHALLENGE IN FORECASTING WIND SPEEDS.
SUSTAINED SE WINDS OF 10 TO 20 MPH WITH PEAK WINDS GUSTS OF 25 TO 30
MPH LIKELY. IF WE DO SEE SOME BREAKS OF SUN AND INCREASED
MIXING...SUSTAINED WINDS OF 20 TO 25 MPH AND GUSTS 35 TO 40 MPH ARE
POSSIBLE AWAY FROM MARINE INFLUENCE.
IN TERMS OF TEMPS...TEMPS ALREADY STARTING AT RECORD LEVELS (LOWER
TO UPPER 60S) AT 5 OF 6 FIRST ORDER CLIMATE SITES THIS MORNING. LOW
SUN ANGLE...ABUNDANT CLOUD COVER...AND MIXING LIMITED TO 950
HPA...WILL LIMIT POTENTIAL HEATING. BUT RECORD TEMPS IN THE UPPER
60S TO LOWER 70S ARE EXPECTED FOR MOST OF THE REGION...WITH
POTENTIAL FOR MID TO UPPER 70S NYC/NJ METRO IF BREAKS OF SUN ARE
REALIZED.
TONIGHT...MODELS HAVE TRENDED SLOWER WITH COLD FRONTAL PASSAGE.
WITH MODELS SIGNALING WEAK DAYTIME CONVECTION INDUCED VORTS
TRACKING IN THE SW FLOW ALOFT...WITH LINGER SHOWER THREAT ACROSS
NYC/NJ METRO AND LONG ISLAND INTO THE OVERNIGHT.
OTHERWISE...UNSEASONABLY MILD CONDITIONS EXPECTED TO CONTINUE WITH
LOWS GENERALLY IN THE 50S CITY/COAST AND 40S INTERIOR. LIGHT NW
FLOW EXPECTED IN THE WAKE OF THE FRONT...WITH SOME DRIER AIR
TRYING TO ADVECT IN. AMOUNT OF CLOUD COVER ALOFT WILL DETERMINE
DENSE FOG COVERAGE...BUT POTENTIAL EXISTS FOR AT LEAST PATCHY
DENSE FOG.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
MODELS COMING INTO BETTER AGREEMENT WITH CHRISTMAS INTO SATURDAY
PERIOD...WITH TROUGHING CONTINUING TO DEEPEN INTO THE SW US AND
BERMUDA HIGH SLOWLY DRIFTING SW TOWARDS FLORIDA. THIS WILL
CONTINUE TO PLACE THE REGION UNDER A DEEP SW PAC/SUB TROPICAL
FLOW.
AT THE SURFACE...APPEARS TO BE BETTER AGREEMENT WITH WEAK RIDGING
BUILDING INTO THE REGION ON CHRISTMAS DAY...PUSHING TODAYS COLD
FRONT TO THE MID ATLANTIC. THE SUBSIDENCE AND LOW-MID LEVEL
DRYING SHOULD PRESENT A DRY...AND ANOTHER RECORD BREAKING WARM
DAY. A PERIOD OF MOSTLY SUNNY SKIES LIKELY AFTER MORNING
STRATUS/FOG BURN OFF AND BEFORE HIGH CLOUD START TO STREAM IN IN
THE AFTERNOON.
MODELS CONVERGING ON AN INCREASING CHANCE FOR RAIN FRIDAY NIGHT INTO
SAT. AS THE WESTERN TROUGH APPROACHES THE CENTRAL US...DECENT
AGREEMENT IN A SERIES OF LOW PRESSURE WAVES BEGIN TO DEVELOP FROM
THE GULF COAST UP THE MISSISSIPPI RIVER VALLEY...LIFTING THE WARM
FRONT ACROSS THE MID-ATLANTIC UP TOWARDS THE REGION. POTENTIAL
FOR A FEW PERIODS OF LIGHT TO MODERATE RAIN AS SERIES OF WEAK
WAVES RIDE ALONG THE WARM FRONT INDUCED BY SOUTHERN STREAM
ENERGIES ROUNDING THE RIDGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS DIFFER WITH THE POSITION AND TIMING OF A SERIES OF FRONTAL
PASSAGES AND LOW PRESSURE SYSTEMS ASSOCIATED WITH THEM...BUT
GENERALLY A MILD AND UNSETTLED PATTERN. MONDAY HAS THE BEST
CHANCE OF REMAINING DRY AS HIGH PRESSURE BUILDING IN FROM THE
NORTH WOULD APPEAR TO BE STRONG ENOUGH TO SUPPORT IT. TUESDAY HAS
THE BEST CHANCE OF SEEING PCPN...BUT WILL CAP POPS AT CHC DUE TO
THE UNCERTAINTY. FOR LATE MONDAY NIGHT INTO TUESDAY
MORNING...THERMAL PROFILES COULD SUPPORT A WINTRY MIX FOR THE
NORTHERN FRINGE ZONES.
TEMPERATURES THROUGH THE LONG TERM MAINLY WARMER THAN NORMAL.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
A COLD FRONT WILL APPROACH FROM THE WEST THIS AFTERNOON. IFR AND
BELOW CONDITIONS CONTINUE INTO THIS MORNING. DENSE FOG WILL AFFECT
SOME TERMINALS...BUT IT IS UNCERTAIN WHERE VSBYS WILL DROP TO 1/4 OR
BELOW BESIDES KHPN. ANY IMPROVEMENT THROUGH THE DAY IS EXPECTED TO
BE MARGINAL AT MOST. THERE WILL BE A CONTINUED CHANCE OF SHOWERS
GOING INTO THE DAY.
LOW LEVEL JET STILL PRESENT BUT THE CORE HAS PASSED TO THE EAST.
STILL...WINDS AT 2KFT EXPECTED TO BE SW AT 40-45 KT THROUGH MUCH OF
THE MORNING. AT THE SURFACE...A 10-15 KT S-SW FLOW WILL START TO
LOWER THIS AFTERNOON AND FURTHERMORE TONIGHT. ANOTHER ROUND OF FOG
AND LOW STRATUS WILL BE POSSIBLE LATE TONIGHT.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING OF
IMPROVEMENT FROM LIFR/IFR...WHICH COULD BE OFF BY A FEW HOURS.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING
OF IMPROVEMENT FROM LIFR/IFR...WHICH COULD BE OFF BY A FEW HOURS.
KEWR FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY MVFR
THIS MORNING. AMENDMENTS LIKELY TO REFINE TIMING OF IMPROVEMENT FROM
IFR...WHICH COULD BE OFF BY A FEW HOURS.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 3-5SM OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY
MVFR/VFR. AMENDMENTS LIKELY TO REFINE TIMING OF IMPROVEMENT FROM
LIFR/IFR...WHICH COULD BE OFF BY A FEW HOURS.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING OF
IMPROVEMENT FROM VLIFR...WHICH COULD BE OFF BY A FEW HOURS.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING
OF IMPROVEMENT FROM LIFR/IFR...WHICH COULD BE OFF BY A FEW HOURS.
.OUTLOOK FOR 09Z FRIDAY THROUGH MONDAY...
.FRIDAY...IFR POSSIBLE IN THE MORNING.
.SAT-SUN...MVFR OR LOWER POSSIBLE IN -RA.
.MON...SLIGHT CHANCE OF -SHRA WITH MVFR OR LOWER.
&&
.MARINE...
WITH PROLONGED SOUTHERLY FETCH...SEAS ON THE OCEAN WILL STAY
ELEVATED. SCA REMAINS IN EFFECT THERE AS WINDS TOO HAVE BEEN GUSTING
TO 25-30 KT. THE WINDS WILL LOWER TONIGHT AND FRIDAY WHILE OCEAN SEAS
WILL LIKELY STAY ELEVATED WITH CONTRIBUTING SWELL. OTHER WATERS WILL
STAY BELOW SCA THROUGH FRIDAY.
WITHOUT MUCH OFFSHORE FLOW IN THE FORECAST...THE HIGHER OCEAN SEAS
MAY VERY WELL LINGER INTO THIS WEEKEND. HOWEVER GOING INTO THE
WEEKEND...FORECAST OCEAN WAVE HEIGHTS ARE MORE MARGINAL FOR
SCA...RIGHT AROUND 5 FT FRIDAY NIGHT THROUGH SATURDAY NIGHT.
WITH ABUNDANT LOW-LEVEL MOISTURE OVER THE WATERS...WIDESPREAD
DENSE FOG WILL CONTINUE THROUGH THE DAY. THE DENSE FOG ADVISORY HAS
BEEN EXTENDED TO 6 PM FOR MOST WATERS.
WINDS WILL EVENTUALLY INCREASE...BUT GUSTS TO 25KT APPEAR TO
BE LIMITED TO MAINLY THE OCEAN SUNDAY NIGHT AND MONDAY. THERE IS A
CHANCE THAT 25KT GUSTS OCCUR ON THE EASTERN SOUND AS WELL.
&&
.HYDROLOGY...
BASIN AVG QPF FROM .75 TO 2 INCHES WAS NOTED ACROSS THE TRI-STATE
WITH THIS RAIN EVENT.
ADDITIONAL LIGHT TO MODERATE RAINFALL POSSIBLE THIS WEEKEND. A SIGNIFICANT
RAINFALL IS POSSIBLE EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH TIDES THIS MORNING IN COMBINATION WITH RESIDUAL SURGE COULD
CAUSE BRIEF AND LOCALIZED MINOR COASTAL FLOODING ACROSS THE
TYPICALLY VULNERABLE LI SOUTH SHORE BAYS LOCALES. SURGE OF 3/4 TO
1 1/2 FT WILL BE NEEDED TO REACH MINOR COASTAL FLOODING BENCHMARKS
THERE.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR DECEMBER 24TH HAVE ALREADY BEEN SET AT
MOST OF THE CLIMATE SITES SO FAR. SEE BELOW FOR THE HIGHS SO FAR AND
THE FINAL HIGH TEMPERATURES WE ARE FORECASTING LATER TODAY.
LOCATION HIGH YEAR FORECAST
NEWARK 68 2015 75
BRIDGEPORT 61 2015 66
CENTRAL PARK 67 2015 74
LAGUARDIA 63 1990 73
KENNEDY 61 2015 69
ISLIP 62 2015 66
HERE ARE THE HIGH TEMPERATURE RECORDS AND FORECAST HIGHS
FOR DECEMBER 25...CHRISTMAS DAY...
LOCATION HIGH YEAR FORECAST
NEWARK 69 1964 67
BRIDGEPORT 59 1964 63
CENTRAL PARK 64* 1982 66
LAGUARDIA 63 2014 66
KENNEDY 58 1982 65
ISLIP 56 2014 64
*ALSO OCCURRED IN PREVIOUS YEARS
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ338.
DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-335-
340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...JC
AVIATION...JM
MARINE...JM
HYDROLOGY...NV
TIDES/COASTAL FLOODING...NV
CLIMATE...JM
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
124 AM EST THU DEC 24 2015
.PREV DISCUSSION... /ISSUED 852 PM EST WED DEC 23 2015/
..ISOLATED SEVERE STORMS OR TORNADOES POSSIBLE MAINLY AFTER
MIDNIGHT ALONG WITH CONTINUED FLOODING THREAT...
UPDATE...
MADE A FEW ADJUSTMENTS TO OVERNIGHT AND MORNING POP TREND THOUGH
STILL KEEP LIKELY TO CATEGORICAL GOING FOR NW MAJORITY OF CWA.
INCLUDED SEVERE MENTION AS A POSSIBILITY PRIMARILY AFTER MIDNIGHT
AS RAP INDICATING NOSE OF 500 J/KG SBCAPE MAY FINALLY MAKE A PUSH
NORTHEAST INTO THE AREA...WHICH IS ALREADY STRONGLY SHEARED
INCLUDING A ROBUST 50-60 KT 850MB JET AND A WHOPPING 500-700 M2S2
OF 0-1KM SRH. NEEDLESS TO SAY WOULD NOT TAKE MUCH TO HAVE A
GREATER SEVERE/TORNADO THREAT WITH ANY INCREASE IN INSTABILITY.
FLOODING THREAT CONTINUES ALSO...AND COULD BE A GREATER URBAN
FLOODING THREAT IF SOME OF THE LATEST WRF SOLUTIONS PAN OUT AS A
CONVECTIVE BAND STALLS FROM SW TO NE ACROSS NORTH GA WHICH COULD
INCLUDE METRO ATLANTA THURSDAY MORNING. WILL NEED TO KEEP A CLOSE
EYE ON SUBSEQUENT RUNS AND OTHER TRENDS SINCE THIS COULD
SIGNIFICANTLY RESULT IN LOCALLY HIGHER QPF VALUES. OTHERWISE MADE
JUST MINOR ADJUSTMENTS TO TEMPS/DEWPTS AND PREVIOUS DISCUSSION
FOLLOWS...
BAKER
PREV DISCUSSION... /ISSUED 732 PM EST WED DEC 23 2015/
SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
FLOOD WATCH CONTINUES THROUGH FRIDAY EVENING...
MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM. LATEST RADAR
TRENDS SHOW SOUTHERN EDGE OF THE PRECIP SHIELD LIFTING NORTH. AT
THE SAME TIME TSTORMS ARE DEVELOPING ALONG THE SOUTHERN EDGE. WE
WILL SEE THE RISK OF THUNDER INCREASE ACROSS THE CWA AS THE REST
OF THIS AFTERNOON AND EVENING PROGRESSES. THERE IS A RISK OF
SEVERE STORMS AS SHEAR IS ALSO INCREASING AS WELL AS CAPE. THERE
WILL BE A LULL IN THE THUNDER LATE THIS EVENING...BUT AS THE COLD
FRONT APPROACHES THE TENNESSEE VALLEY...INSTABILITY WILL INCREASE
AGAIN ALONG WITH SHEAR AND WE WILL SEE ANOTHER ROUND OF THUNDER
WITH ANOTHER RISK OF SEVERE STORMS INCLUDING ISOLATED TORNADOES.
THE RISK WILL LIKELY CONTINUE INTO THURSDAY ACROSS NORTH GEORGIA
AS SHEAR REMAINS HIGH AND THE FRONT STALLS KEEPING HIGH CAPES
ACROSS NORTH GA. CENTRAL GA COULD SEE THUNDERSTORMS
THURSDAY...ALTHOUGH THE BETTER RISK WILL BE ACROSS NORTH GA. NEAR
RECORD/RECORD HIGH TEMPS WILL CONTINUE THROUGH THE SHORT TERM.
17
LONG TERM /FRIDAY THROUGH WEDNESDAY/...
FLOOD WATCH CONTINUES THROUGH MID DAY FRIDAY WITH THE PRIMARY
FOCUS SHIFTING TO NORTH GA AT THE BEGINNING OF THE PERIOD BEFORE
THE FLOOD THREAT DIMINISHES BY THE WEEKEND.
AT THE START OF THE PERIOD...STRONG MID LEVEL RIDGING CENTERED
JUST SOUTH OF BERMUDA HELPING TO MAINTAIN THE PERSISTENT SOUTHWEST
FLOW ALOFT ACROSS THE SOUTHEASTERN STATES. THE REMNANT BOUNDARY
THAT PLAGUES US THROUGH EARLY FRIDAY LIFTS NORTH OF THE AREA
FRIDAY NIGHT LEAVING BEHIND THE WARM SOUPY AIRMASS INTO THE
WEEKEND...BUT NOT BEFORE DROPPING ANOTHER 1 TO 2 INCHES OF
PRECIPITATION ACROSS FAR NORTH GA. BOTH THE GFS AND ECMWF
GENERALLY AGREE THAT SOUTHERN TN AND OR NORTH GA WILL HAVE A
RESIDUAL THREAT FOR HEAVY RAIN EARLY FRIDAY THROUGH MIDDAY BEFORE
LIFTING NORTH OF THE REGION. GIVEN THE REMNANT MOISTURE IN PLACE
AS THE FRONT LIFTS NORTH...AM EXPECTING SOME AREAS OF FAIRLY DENSE
FOG TO FORM FRIDAY NIGHT INTO SATURDAY AM...SO SAFE TRAVELS HOME
FOR THOSE ON THE ROAD LATE CHRISTMAS DAY. WEEKEND LOOKS GENERALLY
WARM AND PARTLY TO MOSTLY CLOUDY. CANNOT RULE OUT A STRAY SHOWER
OR TSTORM BUT NOT EXPECTING MUCH IN THE WAY OF STORMS THROUGH THE
WEEKEND.
VERY STRONG JET MAX OF 150KTS DIVING SOUTH ON THE WEST COAST OF
THE US FRIDAY AFTERNOON WILL BE THE NEXT WEATHER MAKER FOR OUR
REGION BY EARLY NEXT WEEK. BY LATE SATURDAY BOTH THE ECMWF AND GFS
CLOSE OFF A PRETTY STRONG UPPER LOW OVER NEW MEXICO SETTING THE
STAGE FOR BOTH SEVERE WEATHER AND HEAVY SNOWS IN THE SOUTHERN
PLAINS AND SOUTHERN ROCKIES. BOTH THE GFS AND ECMWF GENERALLY
AGREE ON LIFTING THAT SYSTEM NORTHEAST ALONG A VERY SIMILAR TRACK TO
THE CURRENT SYSTEM ACROSS TX..AR..AND INTO THE OHIO VALLEY. THE
DIFFERENCE IS THAT THIS SYSTEM IS A TAD CLOSER TO OUR AREA AND MAY
POSE MORE OF A SEVERE THREAT BY LATE MONDAY INTO EARLY TUESDAY.
HAVE INCLUDED LIKELY POPS DURING THAT PERIOD GIVEN THE RELATIVE
AGREEMENT BETWEEN THE LONG RANGE MODELS AND CONFIDENCE THAT WE
WILL HAVE BOTH INSTABILITY AND SHEAR ACROSS THE AREA. WILL
CERTAINLY HAVE TO WATCH THAT SYSTEM AS IT COMES CLOSER.
WITH THE UPPER SYSTEM LIFTING NORTHEAST...WE ONLY GET A MODEST
COOL DOWN IN DAYS 6 AND 7. IT ISNT UNTIL MID TO LATE WEEK WHEN
ANOTHER DISTURBANCE ROLLS THROUGH THAT HAS MUCH MORE SEASONABLE
IE WINTER...AIRMASS ASSOCIATED WITH IT.
30
CLIMATE...
RECORDS FOR 12-23
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 73 1933 25 1989 61 1970 13 1989
1931
KATL 73 1990 22 1989 62 1879 8 1989
KMCN 82 1970 28 1989 62 1990 15 1989
KCSG 77 1990 26 1989 63 1970 14 1989
1970
RECORDS FOR 12-24
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 77 1964 31 1945 60 1964 7 1983
KATL 72 1984 28 1963 60 1879 3 1983
1964
KMCN 77 1964 35 1993 62 1964 10 1989
1983
KCSG 79 1984 35 1989 60 1988 9 1989
1964
1955
RECORDS FOR 12-25
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 77 1982 22 1983 61 1982 3 1983
1955
KATL 72 1987 17 1983 59 1982 0 1983
1889
KMCN 78 1982 25 1983 61 1982 7 1983
1932
KCSG 76 1982 24 1983 60 1982 8 1983
1964
RECORDS FOR 12-26
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 74 1964 30 1980 61 1987 9 1983
1928
KATL 72 1987 26 1935 61 1987 5 1983
KMCN 77 1987 33 1902 61 1987 9 1983
1982 1964
KCSG 80 1987 33 1983 64 1987 10 1983
RECORDS FOR 12-27
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 73 1971 33 1917 56 1982 11 1935
KATL 71 1982 27 1892 58 1982 12 1925
1889
KMCN 78 1987 35 1902 61 1987 17 1902
KCSG 75 2008 43 1948 61 1987 23 1985
1982
RECORDS FOR 12-28
MAX TEMPERATURE MIN TEMPERATURE
STATION HIGH LOW HIGH LOW
------- ---------- ---------- ---------- ----------
KAHN 78 1928 32 1950 59 1982 8 1925
KATL 74 1984 15 1894 58 1954 5 1925
1971
KMCN 76 2008 31 1925 65 1942 11 1925
2007
KCSG 80 1984 36 1950 59 2008 23 2010
1954 1977
&&
.AVIATION...
06Z UPDATE...
SHOWERS CONTINUING THROUGH THE PERIOD WITH MOSTLY IFR CEILINGS.
THERE WILL BE SOME ISOLATED THUNDERSTORMS THIS MORNING BUT SHOULD
BE MOSTLY SHOWERS THROUGH THE TAF PERIOD. WINDS WILL BE MAINLY OUT
OF THE S BUT WILL SEE PERIODS OF SW AND SE WINDS THROUGH THE
PERIOD. WIND SPEEDS WILL STAY MAINLY 10KT OR LESS BUT WILL SEE
SOME GUST TO NEAR 18KT IN AND AROUND ANY STRONGER STORMS. VSBYS
SHOULD STAY IN THE VFR TO MVFR RANGE.
//ATL CONFIDENCE...06Z UPDATE...
CONFIDENCE MEDIUM TO HIGH ON ALL ELEMENTS
01
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 73 65 74 62 / 60 60 40 40
ATLANTA 73 65 74 64 / 70 70 40 30
BLAIRSVILLE 70 61 71 61 / 80 70 60 50
CARTERSVILLE 74 64 74 63 / 70 70 40 40
COLUMBUS 76 66 78 63 / 60 50 20 20
GAINESVILLE 71 64 72 63 / 70 70 40 40
MACON 76 65 78 61 / 40 30 10 20
ROME 74 63 75 62 / 80 70 40 50
PEACHTREE CITY 74 65 75 61 / 60 60 40 30
VIDALIA 81 66 81 63 / 20 20 5 20
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH THROUGH FRIDAY EVENING FOR THE FOLLOWING ZONES:
BALDWIN...BANKS...BARROW...BARTOW...BIBB...BLECKLEY...BUTTS...
CARROLL...CATOOSA...CHATTAHOOCHEE...CHATTOOGA...CHEROKEE...
CLARKE...CLAYTON...COBB...COWETA...CRAWFORD...CRISP...DADE...
DAWSON...DEKALB...DODGE...DOOLY...DOUGLAS...EMANUEL...FANNIN...
FAYETTE...FLOYD...FORSYTH...GILMER...GLASCOCK...GORDON...
GREENE...GWINNETT...HALL...HANCOCK...HARALSON...HARRIS...HEARD...
HENRY...HOUSTON...JACKSON...JASPER...JEFFERSON...JOHNSON...
JONES...LAMAR...LAURENS...LUMPKIN...MACON...MADISON...MARION...
MERIWETHER...MONROE...MONTGOMERY...MORGAN...MURRAY...MUSCOGEE...
NEWTON...NORTH FULTON...OCONEE...OGLETHORPE...PAULDING...PEACH...
PICKENS...PIKE...POLK...PULASKI...PUTNAM...ROCKDALE...SCHLEY...
SOUTH FULTON...SPALDING...STEWART...SUMTER...TALBOT...
TALIAFERRO...TAYLOR...TELFAIR...TOOMBS...TOWNS...TREUTLEN...
TROUP...TWIGGS...UNION...UPSON...WALKER...WALTON...WARREN...
WASHINGTON...WEBSTER...WHEELER...WHITE...WHITFIELD...WILCOX...
WILKES...WILKINSON.
TORNADO WATCH UNTIL 5 AM EST EARLY THIS MORNING FOR THE
FOLLOWING ZONES: CATOOSA...DADE...WALKER.
&&
$$
SHORT TERM...01
LONG TERM....41
AVIATION...01
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1101 PM CST WED DEC 23 2015
.UPDATE...
ISSUED AT 840 PM CST WED DEC 23 2015
Cold front in the process of pushing through the forecast area
this evening accompanied by strong southwest to west winds gusting
up to 45 mph at times. Strongest surface pressure rises now
shifting quickly to our north this hour suggesting our bout with
strong winds will be short lived with most areas seeing the winds
subside after midnight. The showers and storms quickly exited the
forecast area around 00z with some lower clouds streaming in from
the west signaling a change to cooler weather for the next couple
of days. Have made some adjustments to the forecast with respect
to removing precip for the overnight hours and tweaking the wind
gusts thru late this evening. Expanded the Wind Advisory a bit
further east for the rest of the evening hours as well. Should
have the latest update out by 900 pm.
&&
.SHORT TERM...(Tonight)
ISSUED AT 312 PM CST WED DEC 23 2015
First round of severe weather has exited the eastern forecast area
early this afternoon, but storms have quickly started to fire in
northeast Missouri. This particular area has seen some sunshine
during the afternoon, helping to destabilize the atmosphere, where
CAPE`s are above 500 J/kg and 0-6km bulk shear is an impressive 60-
70 knots. HRRR latched onto this area of development earlier, and
races it across the northern part of the forecast area between 4 pm
and 8 pm. Have concentrated the highest PoP`s for the rest of the
afternoon in this area. The storms should be weakening after sunset
as the surface low pulls northeast, and there is some question about
how much the atmosphere across the eastern CWA can recover after
being thoroughly worked over the last several hours.
Secondary concern is with the winds this evening. Have issued a Wind
Advisory for the period from 6 pm to 2 am across about the northwest
half of the forecast area. Main surface low is currently located
across northeast Iowa, and will be zipping northeast. Impressive 3-
hour pressure rises of 10-11 mb are progged to track northeastward
to around Rockford by midnight. Wind gusts of 45 mph or so are
likely across the northwest half of the forecast area as this
bullseye passes. Have gone as far south as Jacksonville with the
advisory, but this area may be of a shorter duration. Most of the
winds should be diminishing around midnight, but will linger a bit
longer north of I-74.
.LONG TERM...(Thursday through Wednesday)
ISSUED AT 312 PM CST WED DEC 23 2015
Short and medium range models are in fairly good agreement with the
overall active weather pattern through the weekend and into early
next week. Unseasonably warm temperatures and very wet weather will
be the main factors for the weekend through late Monday.
In the shorter term, mild temperatures and periods of cloudiness can
be expected for Christmas Eve into much of Christmas Day. The return
of a surface boundary north of the Ohio Valley and associated weak
isentropic lift initially will result in a chance for light rain in
southeast IL late on Christmas Day. The GFS is the odd model out on
this one by keeping the boundary much farther south.
Backing upper level flow in response to a digging trough in the
western U.S. will allow very warm and moist air to return into much
of central and SE IL during the day Saturday. This feed of moisture
and the associated rainfall will linger in the forecast area through
most of Sunday, resulting in 2.50 to 3.50 inches of rain. The
precipitation area will gradually sag south as the upper low in the
west closes off in SW Texas and an upper level confluent area sets
up across central IL by later in the day Sunday.
The upper low in the southwestern U.S. is expected to kick out
toward the Midwest Monday as another strong upper level trough digs
from the Pacific NW to the southern Plains. This will bring the
likelihood of precipitation back to central IL for Monday. The
forecast type becomes a bit tricky north of a Rushville-Bloomington
line Monday into Monday night as upper level soundings indicate a
mix of rain/snow/sleet possible. Could be some minor accumulations
of snow NW of Peoria late Monday, but there is a lot of uncertainty
with this scenario 6 days out.
&&
.AVIATION...(For the 06Z TAFS through 06Z Thursday night)
ISSUED AT 1100 PM CST WED DEC 23 2015
The storm system that brought the active weather to our area over
the past 24 hours has shifted well to our north late this evening
which will result in a rapid decrease in wind speeds overnight.
A couple of bands of MVFR cigs were tracking east across the
region tonight with cigs in the 1500-2500 foot range. Will
continue to include a tempo group with these clouds thru about
08-09z with VFR conditions expected after that. Scattered to
broken mid and high level clouds will move in during the morning
on Thursday as a weak weather system pushes across the Plains.
Other than the mid and high clouds, not much else expected with
this system in our area during the day. Westerly winds will
continue their diminishing trend overnight with speeds ranging
from 12 to 20 kts with an occasional gust to 32 kts at times
across the east and north thru about 08z. Winds should begin
to back into the southwest and then south on Thu with speeds
of 10 kts or less.
&&
.ILX Watches/Warnings/Advisories...
Wind Advisory until 2 AM CST Thursday for ILZ027>031-036>038-
040>053.
&&
$$
UPDATE...Smith
SHORT TERM...Geelhart
LONG TERM...Miller
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1243 AM EST THU DEC 24 2015
.AVIATION...
GUSTY SOUTH WIND AND BORDERLINE VFR/MVFR CEILING WILL PRECEDE A COLD
FRONT THAT WILL SURGE ACROSS LOWER MICHIGAN BEFORE SUNRISE. THE
LATEST OBSERVATIONS SUPPORT JUST A FEW BRIEF SHOWERS ALONG THE
FRONT...LEAVING THE MAIN STORY AS STRONG WESTERLY WIND GUSTS
REACHING THE 30 TO 40 KNOT RANGE. THERE IS POTENTIAL FOR GUSTS UP TO
45 KNOTS WHICH WILL BE MONITORED FOR IN UPSTREAM OBSERVATIONS DURING
THE NIGHT. THE GUSTY CONDITIONS WILL LAST THROUGH MID MORNING BEFORE
STEADILY DECREASING DURING THE AFTERNOON. THE AIR BEHIND THE FRONT
WILL BE JUST SLIGHTLY COOLER BUT MUCH DRIER WHICH WILL SUPPORT VFR
CONDITIONS INTO THURSDAY EVENING.
FOR DTW... BORDERLINE MVFR/VFR CEILING AND A BREAK IN PRECIPITATION
WILL CONTINUE DURING THE EARLY MORNING...ALONG WITH GUSTY SOUTH
WIND. TIMING ON THE COLD FRONTAL PASSAGE LOOKS SOLID AROUND 09Z WITH
WESTERLY WIND GUSTS REACHING THE 30 TO 40 KNOT RANGE THROUGH LATE
MORNING.
//DTW THRESHOLD PROBABILITIES...
* MODERATE FOR CEILING BELOW 5000 FEET FOR THE REST OF TONIGHT.
* MODERATE TO HIGH FOR GUSTS EXCEEDING CROSSWIND THRESHOLD AFTER 09Z.
&&
.PREV DISCUSSION...ISSUED 1027 PM EST WED DEC 23 2015
UPDATE...
THE FORECAST UPDATE WILL EXTEND THE WIND ADVISORY OVER THE REST
OF SE MICHIGAN AND MAKE IT VALID WITH ISSUANCE. MID TO LATE
EVENING SURFACE OBSERVATIONS REPORT FREQUENT SOUTH WIND GUSTS IN
THE MID 30 MPH RANGE WITH A FEW REPORTS OVER 40 MPH. THIS IS
OCCURRING IN THE WARM SECTOR IN PLACE OVER LOWER MICHIGAN
ASSOCIATED WITH RAPIDLY DEEPENING LOW PRESSURE OVER WISCONSIN. THE
NEUTRAL STABILITY PROFILE ADVERTISED IN RAP MODEL SOUNDINGS
SUGGESTS WARM SECTOR GUSTS COULD REACH 45 MPH BEFORE THE COLD
FRONT ARRIVES OVERNIGHT. AS FOR THE COLD FRONT ITSELF...UPSTREAM
OBSERVATIONS REPORT PEAK GUSTS AROUND 50 MPH AS FAR SOUTH AS
PEORIA/IL WITHIN STRONG ISALLOBARIC FORCING. THE EXTRA FORCING AND
50 MPH PEAK GUSTS WILL BE SHORT-LIVED BUT MID 40 MPH GUSTS WILL
REMAIN COMMON THROUGH MID THURSDAY MORNING. THE 10 AM EXPIRATION
TIME OF THE HEADLINE LOOKS GOOD.
PREV DISCUSSION...ISSUED 323 PM EST WED DEC 23 2015
DISCUSSION...
STRONG SURFACE LOW HAS BEGUN ITS NEXT DEEPENING PHASE THIS AFTERNOON
AS VIGOROUS SHORTWAVE HAS ROUNDED THE BASE OF THE MEAN UPPER LEVEL
TROUGH OVER THE PLAINS/MIDWEST. THE 982MB LOW OVER EC IOWA WILL
DEEPEN TO ABOUT 974MB BY THE TIME IT REACHES LAKE SUPERIOR TONIGHT
AND THEN CONTINUE STRENGTHEN IS IT LIFTS TO JAMES BAY AND BEYOND ON
THURSDAY.
WARM FRONT IN ADVANCE OF THIS SYSTEM IS CURRENTLY WORKING NORTH
THROUGH THE FORECAST AREA WITH ALL LOCATIONS NOW CLIMB THROUGH THE
50S WITH A FEW 60 DEGREE READINGS NOTED SOUTH OF DETROIT. DEWPOINTS
WITHIN THIS MILDEST SECTOR HAVE ALSO CLIMBED INTO THE UPPER 50S AS
MODELS SUGGESTED WOULD OCCUR. AS THE WARM AND MOIST AIR CONTINUES TO
OVERSPREAD THE AREA...EXPECT TEMPERATURES TO CLIMB INTO THE 60S AREA
WIDE...SETTING RECORD HIGH TEMPERATURES FOR THE DAY AND ALSO SETTING
UP A MARGINALLY UNSTABLE AIRMASS OVER PARTS OF THE AREA BY THIS
EVENING.
THIS WILL ALLOW ONGOING STRONG TO LOCALLY SEVERE CONVECTIVE LINE
SEGMENTS FROM WESTERN INDIANA AND SOUTHEAST ILLINOIS TO WORK INTO
THE AREA EARLY THIS EVENING. THERE WILL MOST LIKELY BE A SLIGHT
WEAKENING TREND ONCE THIS ACTIVITY ENCROACHES ON THE AREA AS THE
AIRMASS STILL WILL NOT BE QUITE A UNSTABLE AS THE CURRENT AIR
FEEDING INTO ONGOING STORMS TO THE SOUTHWEST. THIS WILL RESULT IN
GUSTY WINDS WITH LOCALLY DAMAGING WIND GUSTS STILL POSSIBLE WITHIN
THE STRONGEST PORTIONS OF THE CONVECTIVE LINE(S) THAT MAKE IT THIS
FAR NORTHEAST.
WHILE A LOW LIKELIHOOD...AN ISOLATED TORNADO STILL CANNOT BE RULED
OUT GIVEN THE STRONG LOW LEVEL SHEAR THAT WILL BE IN PLACE ONCE THIS
ACTIVITY PROPAGATES INTO THE AREA. BY AND LARGE THE MOST LIKELY
SEVERE WEATHER SCENARIO WILL BE ISOLATED POCKETS OF 60 MPH WIND
GUSTS CAUSING SOME DAMAGE AS CONVECTION TAPS INTO THE 60+ KNOT LOW
LEVEL FLOW AND BRINGS SOME OF IT TO THE SURFACE AT TIMES.
ADDITIONAL SHOWERS OR THUNDERSTORMS WILL BE POSSIBLE FROM MID
EVENING INTO THE OVERNIGHT AS THE WARM AND MOIST AIRMASS REMAINS IN
PLACE AND EVEN BUILDS SLIGHTLY IN ADVANCE OF APPROACHING COLD FRONT
WHICH WILL CROSS THE AREA ROUGHLY BETWEEN 06Z-09Z. WITH THE SURFACE
LOW TRACK SO FAR TO THE NORTHWEST...BEST PUNCH OF WIND ALONG AND
BEHIND THIS FRONT WILL BE FOCUSED OVER THE NORTHERN CWA...AND WILL
LIMIT THE EXPECT WIND ADVISORY TO AREAS GENERALLY ALONG AND NORTH OF
INTERSTATE 69. THIS ADVISORY WILL BE RATHER SHORT LIVED AS WELL AS
THE RAPID MOVEMENT OF THE LOW INTO CANADA WILL ALLOW WINDS TO RELAX
RATHER QUICKLY THURSDAY MORNING.
MUCH QUIETER WEATHER WILL SET UP FOR THURSDAY AND FRIDAY AS HIGH
PRESSURE BUILDS EAST ACROSS THE AREA. WITH ONLY A MINOR INCURSION OF
COLDER POLAR AIR INTO AREA BEHIND THIS SYSTEM...TEMPERATURES...WHILE
COOLER...WILL REMAIN ABOVE AVERAGE FOR LATE DECEMBER. EXPECT HIGHS
IN THE 40S TO AROUND 50 THURSDAY AND IN THE 40S FRIDAY.
SURFACE LOW DEVELOPING NORTHEASTWARD ALONG BAROCLINIC ZONE PROGGED
TO MOVE THROUGH SE MI SAT. PLENTY OF MOISTURE TO BE LIFTED OVER THE
FRONTAL ZONE /PWAT NEAR 1.50 IN/ WILL SPELL LIKELY RAIN SAT/SAT
NIGHT AND POSSIBLY LINGERING INTO SUNDAY. THE RAIN COULD BE HEAVY
OVER THE SOUTH IF THE FRONT STAYS RELATIVELY STATIONARY AS SOME NWP
IS DEPICTING. THIS SHOULD BE MOSTLY RAIN BUT COULD BRIEFLY END AS
SNOW SAT NIGHT/SUN. ACCUMULATIONS DO NOT LOOK LIKELY AS THE MAJORITY
OF THE PRECIP WILL BE ON THE WARM SIDE. ATTENTION THEN TURNS TO
STRONG CUTOFF LOW EJECTING NWD FROM TX TO THE GREAT LAKES MON/TUE.
STILL SIGNIFICANT INTERMODEL AND RUN-TO-RUN MODEL DIFFERENCES IN
TIMING AND LOW TRACK...BUT ENOUGH CONFIDENCE TO GO WITH LIKELY POPS
CENTERED AROUND MONDAY NIGHT. P TYPE WILL BE TRICKY AND WILL NOT GET
TOO CUTE WITH THE DETAILS THIS FAR OUT. POTENTIAL DOES EXIST FOR
FZRA ON THE LEADING EDGE OF THE PRECIP. THE MOST LIKELY TIME FRAME
FOR THIS IS MONDAY NIGHT BEFORE WE GET INTO THE WARM SECTOR ON
TUESDAY AS DEPICTED BY THE EURO. MEANWHILE THE GFS HAS CONTINUED TO
TREND EASTWARD WITH THE LOW WHICH WOULD OPEN THE DOOR FOR SNOW FOR
PORTIONS OF OUR AREA. DUE TO MODEL DIFFERENCES AND LONG TIME
HORIZON...KEPT BROADBRUSH RAIN/SNOW MENTION FOR NOW.
MARINE...
A STRONG LOW PRESSURE SYSTEM WILL CONTINUE TO STRENGTHEN AS IT
TRACKS NORTH THROUGH THE WESTERN GREAT LAKES OVERNIGHT REACHING
JAMES BAY BY THURSDAY MORNING. THE LOW WILL PULL A COLD FRONT
THROUGH THE EASTERN GREAT LAKES LATE TONIGHT AROUND 09Z. STRONG
WINDS WILL OCCUR BOTH AHEAD OF...AND BEHIND THE COLD FRONT LEADING
TO A LONG DURATION GALE EVENT ACROSS LAKE HURON. THIS EVENING AHEAD
OF THE FRONT...ALREADY GUSTY WINDS WILL BE ENHANCED BY PREFRONTAL
RAIN SHOWERS MIXING DOWN STRONGER WINDS ALOFT MAINLY ACROSS NORTHERN
LAKE HURON. WINDS WILL THEN TURN WESTERLY AND INCREASE FURTHER AS A
TIGHT PRESSURE GRADIENT SOUTH OF THE LOW CENTER LIFTS UP THROUGH THE
REGION. WIND GUSTS WILL REACH STRONG GALE FORCE AROUND 45 KNOTS OVER
NORTHERN LAKE HURON. THE SOUTHERN END OF THE BASIN WILL BE FURTHER
REMOVED FROM THE TIGHTEST GRADIENT BUT SHOULD STILL SEE GALE FORCE
GUSTS OF 35 TO 40 KNOTS LATE TONIGHT INTO THURSDAY MORNING. WINDS
WILL THEN DIMINISH THROUGH THE DAY THURSDAY AS THE LOW QUICKLY LIFTS
NORTHWARD AWAY FROM THE LAKES. WIND GUSTS ARE EXPECTED TO DROP BELOW
20 KNOTS BY 06Z FRIDAY.
HYDROLOGY...
A LOW PRESSURE SYSTEM CURRENTLY OVER IOWA WILL CONTINUE TO
STRENGTHEN AS IT LIFTS NORTH THROUGH THE OVERNIGHT...REACHING JAMES
BAY BY THURSDAY MORNING. VERY WARM AND MOIST AIR LIFTING INTO THE
AREA AHEAD OF THE COLD FRONT WILL RESULT IN GOOD COVERAGE OF RAIN
SHOWERS THIS EVENING WITH ISOLATED THUNDERSTORMS POSSIBLE. MOST
LOCATIONS WILL RECEIVE AROUND 0.5 INCH OF RAIN BY THURSDAY MORNING
WITH ISOLATED TOTALS OF AROUND 1.0 INCH. LITTLE CONCERN FOR FLOODING
EXISTS.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ047>049-053>055-
060>063-068>070-075-076-082-083.
LAKE HURON...GALE WARNING UNTIL NOON EST TODAY FOR LHZ421-422-441-462.
GALE WARNING FROM 4 AM TO 10 AM EST THIS MORNING FOR LHZ442-443-463-
464.
GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LHZ361>363.
LAKE ST CLAIR...GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LEZ444.
&&
$$
AVIATION.....BT
UPDATE.......BT
DISCUSSION...DG/DT
MARINE.......DRK
HYDROLOGY....DRK
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
112 AM EST THU DEC 24 2015
.SYNOPSIS...
UNSEASONABLY WARM, AND SHOWERY WEATHER, WILL PERSIST INTO
THURSDAY. IN FACT, RECORD HIGH TEMPERATURES IN THE MID AND UPPER
60S ARE EXPECTED CHRISTMAS EVE DAY. CHRISTMAS DAY LOOKS DRY, AND
STILL FAIRLY MILD, WITH HIGHS MOSTLY IN THE FIFTIES. RAIN IS
LIKELY BY LATER SATURDAY, AS A WARM FRONT APPROACHES FROM THE
SOUTH.
&&
.NEAR TERM /THROUGH TODAY/...
945 PM UPDATE...
SPED UP TIMING OF FIRST BATCH OF RAIN EVEN FASTER. LOWERED POPS IN
THE WEST TO NOTHING. WILL BE WAITING FOR THE CONVECTION IN OHIO.
MODEL DIFFERENCES ON TIMING AND COVERAGE. FOLLOWING THE HRRR SOME
AND BRINGING IN SHOWERS INTO STEUBEN AROUND 9Z. CONFIDENCE NOT
HIGH ENOUGH TO INCLUDE THUNDER BUT MODELS HINTING AT SOME
REMAINING. TEMPERATURES ARE SLOWLY RISING.
7 PM UPDATE...
RAIN ALREADY PULLING OUT OF WRN ZONES AND DROPPED POPS AND QPF.
REST OF RAIN WILL PULL OUT THIS EVENING. AFTER THAT WILL JUST GET
REMNANTS FROM THE CONVECTION NOW IN THE OHIO VALLEY LATE TONIGHT.
TEMPS ARE TRICKY WITH MAX AND MIN TEMPS ALMOST THE SAME AS
TEMPERATURES RISE TONIGHT. SOME CURRENT TEMPS ABOVE THE AFTN MAX
TEMP GRID. ADJUSTED MAX MIN AND HOURLY TEMPS. CLOUDY SKIES WILL
CONTINUE OVERNIGHT WITH THE DEEP MOIST SOUTHERLY FLOW.
230 PM UPDATE...
SHOWERS ARE OVERSPREADING THE REGION THIS AFTERNOON, RIGHT ON
SCHEDULE, AND THEY SHOULD CONTINUE THROUGH EARLY EVENING. MOST OF
THE FORCED LIFT, WITH THE ASSOCIATED SHORT-WAVE, SHOULD BE EAST
OF OUR FORECAST AREA BY MIDNIGHT. THUS, WE STILL ANTICIPATE A
LULL IN PRECIPITATION OVERNIGHT.
MOST OF OUR HIGH-RESOLUTION MODEL GUIDANCE BRINGS A WEAKENING
LINE OF SHOWERS INTO WESTERN NY/PA DURING THE PRE-DAWN HOURS. THIS
IS LIKELY THE REMNANTS OF THE CONVECTIVE LINE IMPACTING SRN
IL/IN/WRN KY THIS AFTERNOON. AS JUST STATED, THIS LINE OF SHOWERS
SHOULD BE IN A WEAKENING STATE AS IT PROGRESSES EASTWARD, AND AS
SUCH, ITS SURVIVAL INTO OUR FORECAST AREA CLOSE TO DAYBREAK IS
UNCERTAIN. FOR NOW, WE`RE CALLING FOR SCATTERED SHOWERS AFTER 4-5
AM, TO COVER THIS POSSIBILITY.
AS A LOW-LEVEL JET MOVES OVERHEAD LATE TONIGHT INTO EARLY
THURSDAY, CONDITIONS SHOULD BECOME WELL MIXED, THUS MAKING
WIDESPREAD FOG DEVELOPMENT UNLIKELY. PART OF THIS STRENGTHENING
FLOW REGIME WILL ALSO BE VERY PRONOUNCED LOW-LEVEL WARM ADVECTION.
THUS, WE`VE CONTINUED TO INDICATE RISING TEMPERATURES OVERNIGHT,
AND MANY AREAS SHOULD ALREADY BE INTO THE 60S BY 5-8 AM.
A STRENGTHENING CYCLONE WILL CONTINUE TO TRACK THROUGH THE WESTERN
LAKES REGION, AND THEN INTO ONTARIO FOR CHRISTMAS EVE. AS IT DOES
SO, IT WILL SWING A COLD FRONT ACROSS CENTRAL NY/NORTHEAST PA
DURING THE LATE MORNING/EARLY AFTERNOON PERIOD. THE BEST UPPER-
LEVEL DYNAMICS WILL BE UP OVER CANADA, AND WELL REMOVED FROM OUR
REGION. THUS, WE FEEL THAT SHOWER ACTIVITY, ALONG AND AHEAD OF
THE FRONT, WILL BE SCATTERED IN NATURE FOR MOST OF THE FORECAST
AREA. GIVEN THE ANOMALOUS WARMTH, NAM/SREF GUIDANCE IN PARTICULAR
SHOWS WEAK INSTABILITY ON THURSDAY (200-400 J/KG OF ML CAPE). AS A
RESULT, WE HAVE AN ISOLATED MENTION OF THUNDER. SHOWERS SHOULD
HAVE A TENDENCY TO DIMINISH FROM WEST TO EAST DURING THE
AFTERNOON, AS THE FRONT SWEEPS THROUGH THE REGION.
AS MENTIONED EARLIER, RECORD HIGHS SHOULD EASILY BE ATTAINED
THURSDAY (CURRENT RECORDS ARE 51 AT BINGHAMTON, 58 AT SYRACUSE,
AND 62 AT SCRANTON). IN FACT, SOME OF OUR NORMALLY WARMER VALLEY
LOCALES, ESPECIALLY OVER NORTHEAST PA, COULD EVEN MAKE A RUN AT 70
DEGREES!
&&
.SHORT TERM /TONIGHT THROUGH SATURDAY/...
3 PM UPDATE...
LATE CHRISTMAS EVE-CHRISTMAS DAY LOOKS MAINLY DRY, AS THE
AFOREMENTIONED FRONTAL ZONE SINKS SOUTHWARD INTO THE MID-ATLANTIC
REGION. THE AIR MASS BEHIND THE FRONT IS NOT VERY COLD AT ALL, AND
THIS IN COMBINATION WITH SOME SUNSHINE ON FRIDAY, SHOULD STILL
BRING HIGHS INTO THE 50S-LOWER 60S.
SATURDAY, THIS SAME FRONTAL BOUNDARY WILL BEGIN TO HEAD BACK
NORTHWARD AGAIN AS A WARM FRONT, IN RESPONSE TO ANOTHER DEVELOPING
CYCLONE OVER THE SOUTH-CENTRAL STATES. BY LATE SATURDAY, MODEL
GUIDANCE IS IN GOOD AGREEMENT DEPICTING A VERY STRONG UPPER JET
STREAK TO OUR NORTH, WITH THE RESPONSE BEING AN INCREASED LOW-
LEVEL JET/TIGHTENED THERMAL GRADIENT OVER NY/PA, JUST NORTH OF THE
APPROACHING WARM FRONT. ANY EARLY SUNSHINE SHOULD FADE BEHIND
INCREASING CLOUDS. THE LIKELIHOOD OF RAIN SHOULD THEN OVERSPREAD
THE FORECAST AREA, FROM SOUTH TO NORTH, BY LATE SATURDAY/SATURDAY
EVENING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
310 PM UPDATE...
THE LARGE-SCALE PATTERN SHOULD FEATURE AN ENERGETIC SOUTHWESTERLY
FLOW ALOFT EARLY IN THE PERIOD (THROUGH WEDNESDAY), WITH A
DEVELOPING BROAD TROUGH, AND MORE SEASONABLE TEMPERATURES LATER
NEXT WEEK.
AS FOR THE DAILY SENSIBLE WEATHER, MILD SHOWERY WEATHER SUNDAY,
WILL BE FOLLOWED BY A GRADUAL COOL-DOWN EARLY NEXT WEEK. THE
BIGGEST UNCERTAINTY LIES WITH THE EVOLUTION/EJECTION OF A POTENT
SOUTHERN-STREAM WAVE LATE MONDAY-TUESDAY (MODELS DIFFER
SIGNIFICANTLY ON TIMING/SURFACE LOW TRACK). IF PRECIPITATION
DEVELOPS QUICKLY ENOUGH, MIXED PHASE (SNOW/SLEET/FREEZING RAIN
MIX) WOULD BE POSSIBLE MONDAY NIGHT OR TUESDAY. IF THE MOISTURE
DOESN`T MOVE IN UNTIL MID-WEEK, TEMPERATURES SHOULD BE WARM ENOUGH
FOR RAIN BY THEN. TIME WILL TELL ON THIS ONE, WITH BETTER MODEL
AGREEMENT HOPEFULLY SEEN IN LATER RUNS.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
PLENTY OF LOW LEVEL MOISTURE IS LINGERING THIS MORNING. A MIXTURE
OF LOW AND HIGH END MVFR CONDITIONS ARE PRESENT THIS MORNING
ACROSS MUCH OF THE AREA. EXPECT CONDITIONS TO IMPROVE AROUND 12Z
TO VFR. ANOTHER ROUND OF SHOWERS ARE EXPECTED TO MOVE INTO THE
REGION MID MORNING AND IMPACT ALL SITES. THESE SHOWERS ARE
EXPECTED TO BE LESS IMPRESSIVE AS YESTERDAYS... AND HAVE LESS
RESTRICTIONS AS WELL. AFTER THE SHOWERS MOVE TO THE EAST... HIGH
PRESSURE WILL START TO BUILD INTO THE REGION RESULTING IN ALL
SITES BECOMING VFR.
WINDS WILL BE REMAIN SOUTHERLY AHEAD OF THE SHOWERS THIS
MORNING... AND MAY BECOME GUSTY AT TIME WITH GUSTS UP TO 30 KNOTS.
WINDS WILL TRANSITION TO WESTERLY FLOW THIS AFTERNOON... THEN
BECOME LIGHT AND VARIABLE NEAR SUNSET.
FRI...VFR.
SAT/SUN/MON...RESTRICTIONS POSSIBLE IN RAIN.
&&
.CLIMATE...
RECORD WARM TEMPERATURES NEXT 3 DAYS POSSIBLE...ESPECIALLY
DECEMBER 24TH.
WARMEST LOW TEMPERATURES TODAY AND MAYBE THE 25TH. RECORD WARM
HIGH, LOW, AND AVERAGE THE 24TH LIKELY FOR ALL 3 SITES. FORECAST
HIGHS IN THE MID AND UPPER 60S AND LOWS AT MIDNIGHT UPPER 40S TO
LOWER 50S. WILL BE CLOSE TO THE ALL TIME RECORD DECEMBER
TEMPERATURES. BINGHAMTON CLOSEST WITH 65 12/01/2006 AND 12/29/1984
AND 12/06/1982. SYRACUSE 72 12/06/2001. SCRANTON 71 12/01/2006.
TODAY WITH TEMPERATURES STEADY TO RISING THE REST OF TODAY RECORD
MAX MINS. BINGHAMTON 43 TODAY BREAKS THE RECORD OF 40 IN 2006.
SCRANTON 47 TODAY BREAKS THE RECORD OF 45 IN 1931.
SYRACUSE 42 TODAY TIES THE RECORD OF 42 IN 1931.
FOR THE 24TH MAX MIN AVE
BGM 55 2014 42 1965 48 2014
SYR 58 1965 48 1931 52 1931
AVP 62 1933 47 1931 53 1931
THE 25TH MAX MINIMUM TEMPERATURE AT SCRANTON WHERE THE WARM AIR
LINGERS. AGAIN PROBABLY A LOW AT MIDNIGHT THE END OF THE 25TH.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MLJ/TAC
NEAR TERM...MLJ/TAC
SHORT TERM...MLJ
LONG TERM...MLJ
AVIATION...KAH
CLIMATE...
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
405 AM EST THU DEC 24 2015
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE OFFSHORE THROUGH THE WEEKEND. A WEAK
COLD FRONT WILL APPROACH FROM THE NORTH TONIGHT THEN STALL NEAR
THE VIRGINIA BORDER FRIDAY. THE FRONT WILL LIFT BACK NORTH OVER
THE WEEKEND. A COLD FRONT WILL PUSH SOUTH THROUGH THE REGION
SUNDAY NIGHT. HIGH PRESSURE WILL EXTEND SOUTH INTO THE AREA MONDAY
THEN SLIDE OFFSHORE TUESDAY.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 330 AM THURSDAY...THE LINE OF HEAVY SHOWERS AND
THUNDERSTORMS MOVING ACROSS EASTERN SECTIONS HAS BEEN WEAKENING
OVER THE PAST COUPLE HOURS...WHICH IS ALSO EVIDENT IN IR
SATELLITE WITH CLOUD TOP WARMING. STILL SEEING SCATTERED TO
NUMEROUS SHOWERS AND ISOLATED THUNDERSTORMS LIFTING ACROSS THE
REGION...WITH STRONGEST STORMS PRESENTLY IN BEAUFORT CO LIFTING TO
THE NORTHEAST. HRRR HAS MOST OF THESE SHOWERS MOVING OFFSHORE BY
12Z WITH ONLY ISOLATED SHOWERS FOR THE REST OF THE DAY AS LOW PRES
OVER THE GREAT LAKES LIFT NORTH ALLOWING THE UPPER RIDGE AND SFC
HIGH PRES OVER THE WESTERN ATLANTIC WILL BEGIN TO BUILD WEST
TOWARD EASTERN NC DURING THE DAY. WHILE PWATS REMAIN ABOVE
CLIMATOLOGICAL MAX AND AN UNSTABLE AIRMASS REMAINS IN PLACE WITH
LI`S FORECAST TO BE AROUND -6C AND MUCAPE AROUND 2000-3000J/KG...
FORCING IN THE WAY OF EMBEDDED SHORTWAVES WILL BE ABSENT WITH
0-6KM SHEAR WEAKENING TO BELOW 30 KT AND ONLY EXPECT ISOLATED
SHOWERS OR THUNDERSTORMS THIS AFTERNOON AND HAVE LIMITED POPS TO
AROUND 30 PERCENT. THE BIG STORY WILL CONTINUE TO BE THE DEEP S/SW
FLOW BRINGING RECORD WARMTH ACROSS THE REGION. TEMPS ARE A FEW
DEGREES EITHER SIDE OF 70 EARLY THIS MORNING WHICH IS ABOUT 35
DEGREES ABOVE NORMAL LOW TEMPS FOR THIS DAY. HIGHS TODAY ARE
EXPECTED AROUND 80 ACROSS MANY INLAND LOCATIONS WITH MID TO UPPER
70S ALONG THE COAST. MOST CLIMATE LOCATIONS ARE EXPECTED TO SET
NEW RECORD MAX TEMPS AND RECORD HIGH MIN TEMPS FOR THE DAY AND
NEAR OR ABOVE THE ALL-TIME RECORD HIGH TEMPERATURES FOR THE MONTH
OF DECEMBER...SEE CLIMATE SECTION BELOW.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM THURSDAY...UPPER RIDGING AND SFC HIGH PRES CONTINUE
TO BUILD INTO THE SOUTHEASTERN STATES TONIGHT WITH DEEPEST
MOISTURE BEING SHUNTED TO THE WEST AND NORTH. NOCTURNAL SHOWER
ACTIVITY EXPECTED TO BE MINIMAL WITH WEAKENING INSTABILITY AND
LITTLE UPPER LEVEL SUPPORT...THOUGH CANNOT RULE OUT AN ISOLATED
SHOWER SO WILL KEEP 20 POPS IN THE FORECAST. VERY WARM TEMPS WILL
CONTINUE WITH LOWS IN THE MID TO UPPER 60S AND MANY LOCATIONS MAY
SET RECORD HIGH MINIMUM TEMPERATURES AGAIN TONIGHT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 230 AM THU...EXPECT RECORD BREAKING WARMTH THROUGH THE
WEEKEND AS STRONG UPPER RIDGE OVER THE ATLANTIC BUILDS WEST TOWARD
THE COAST.
CHRISTMAS DAY THROUGH SUNDAY...VERY LITTLE PRECIP EXPECTED THRU
THIS PERIOD AS UPR RDG BUILDS CLOSER WHICH WILL ACT TO SUPPRESS
CONVECTION. CONT ISOLD POPS BUT MOST LOCATIONS WILL REMAIN DRY AND
WITH MORE SUN TEMPS WILL AGAIN BE VERY WARM REACHING AROUND 80
WARMER SPOTS THROUGH THE PERIOD. BALMY NIGHTITME LOWS IN THE 60S
EXPECTED.
MONDAY THROUGH WEDNESDAY...UPR RDG WILL BEGIN TO SHIFT BACK E
WITH MDLS SHOWING BACKDOOR FRONT DROPPING THRU THE REGION SUNDAY
NIGHT THEN LIFTING BACK N TUE AHEAD OF STRONGER APPROACHING
FRONT. CONT PREV FCST OF CHC POPS EARLY NEXT WEEK WITH STILL VERY
MILD TEMPS...MAINLY IN 60S MON WARMING BACK INTO THE 70S TUE/WED.
A COLD FRONT APPROACHES FROM THE WEST ON WEDNESDAY BUT TIMING OF
THE FRONTAL PASSAGE VERY MUCH IN QUESTION GIVEN THE POTENTIAL
ERROR IN THE DAY 7 FORECAST...WILL CONTINUE WITH CHC POPS THRU
MIDWEEK FOR NOW.
&&
.AVIATION /08Z THURSDAY THROUGH MONDAY/...
SHORT TERM /THROUGH THURSDAY/...
AS OF 4 AM THURSDAY...MVFR CONDITIONS GENERALLY THE RULE WITH SCT
SHOWERS ACROSS RTES...THROUGH BRIEFLY SEEING CIGS LOWER TO IFR.
MODERATE SLY FLOW AROUND 5-10 KT THROUGH MID MORNING WHICH WILL
LIMIT FOG DEVELOPMENT. MOS GUIDANCE SUGGESTING MVFR CIGS
CONTINUING THROUGH ABOUT 15Z THIS MORNING. DISCOUNTED THE RUC/HRRR
THIS MORNING AS IT APPEARS TO BE AN OUTLIER IN DEVELOPING IFR
CONDITIONS AROUND 10Z THAT CONTINUES INTO THE AFTERNOON HOURS. THE
UPPER RIDGE OVER THE WESTERN ATLANTIC BUILDS TOWARD THE REGION
TODAY WHICH IS EXPECTED TO BRING A DECREASE IN SHOWERS AND
THUNDERSTORMS TODAY BUT A MOIST AND UNSTABLE AIRMASS WILL BE IN
PLACE AND CANNOT RULE OUT ISOLATED TO SCATTERED TSTMS THIS
AFTERNOON. GUSTY S/SW WINDS AROUND 15-20 KT EXPECTED AGAIN
TONIGHT. MODEL SOUNDINGS FAVORABLE FOR STRATUS DEVELOPMENT THIS
EVENING BRINING LIFR CONDITIONS AT THE TERMINALS WHICH IS
SUPPORTED IN MOS GUIDANCE. SW FLOW AROUND 5-10 KT EXPECTED TO
CONTINUE TONIGHT SO THINK MOS GUIDANCE IS TOO PESSIMISTIC WITH
VSBYS.
LONG TERM /FRI THROUGH MONDAY/...
AS OF 230 AM THU...WITH STRONG UPPER RIDGE BUILDING OVER THE
AREA, THE COVERAGE OF SHRA/TSRA WILL BE LIMITED THRU MUCH OF THE
UPCOMING WEEKEND. HOWEVER WITH LOW LEVELS REMAINING VERY MOIST
BOUTS OF SUB VFR STRATUS AND FOG WILL BE LIKELY LATE NIGHT/EARLY
MORN THRU SUNDAY. MAINLY VFR LATE MORN THRU EVENING HOURS WITH
ONLY SMALL CHC OF SHRA/TSRA THRU THE WEEKEND. A BACK DOOR COLD
FRONT DROPS THRU THE AREA SUNDAY NIGHT BRINGING A POTENTIAL FOR
LOW CLOUDS AND FOG BEHIND THE FRONT EARLY NEXT WEEK.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM THURSDAY...LATEST OBS INDICATE S TO SSW WINDS
ACROSS THE EASTERN NC WATERS 15-25 KT WITH GUSTS AROUND 30 KT AT
DIAMOND BUOY. THE SURFACE RIDGE REMAINS CENTERED OFF THE
SOUTHEAST COAST WHILE A COLD FRONT APPROACHES FROM THE WEST.
SOUTHERLY WINDS WILL CONTINUE AROUND 15-25 KT THROUGH ABOUT MID
DAY, THEN SLOWLY DIMINISH AS THE PRESSURE GRADIENT RELAXES AS THE
AFOREMENTIONED FRONT STALLS ACROSS THE APPALACHIANS. SEAS
CURRENTLY AROUND 4-7 FT NORTH OF HATTERAS AND 6-10 FT SOUTH AND
THESE HEIGHTS WILL CONTINUE THROUGH ABOUT MID DAY AS WELL, THEN
GRADUALLY SUBSIDE THROUGH THE REST OF THE SHORT TERM. STRONGEST
WINDS/SEAS WILL OCCUR OVER THE COASTAL WATERS AND WILL MAINTAIN
THE SCA AS ADVERTISED. THE SOUNDS AND RIVERS ARE EXPECTED TO
REMAIN BELOW ADVISORY CRITERIA.
LONG TERM /FRI THROUGH MONDAY/...
AS OF 230 AM THU...WINDS AND SEAS WILL GRAD SUBSIDE FRI AS WEAK
FRONT STALLS TO THE NORTH AND SFC HIGH PRESSURE BUILDS OFF THE SE
COAST. CONT TO HAVE SCA ENDING CNTRL AND SRN WTRS BY MID DAY FRI. THE
PRESSURE GRADIENT WITH THE OFFSHORE HIGH WILL SUPPORT A LIGHT TO
MODERATE (10-15 KT) S/SW FLOW THRU MUCH OF THE UPCOMING WEEKEND
WITH SEAS MAINLY 3 TO 5 FT. MDLS MORE ROBUST WITH NE SURGE BEHIND
BACKDOOR FRONT MON WITH SPEEDS 15 TO 20 KTS AND SOME 6 FT SEAS
OUTER WTRS.
&&
.HYDROLOGY...
WIDESPREAD 3-4 INCHES OF RAIN HAS FALLEN ACROSS THE NC PIEDMONT
AND COASTAL PLAIN OVER THE PAST 3 DAYS WHICH IS CAUSING SEVERAL
MAIN STEM RIVERS TO RISE AND COULD SEE THEM REACH MINOR FLOOD
STAGE AND EARLY AS TONIGHT WITH OTHERS POSSIBLY REACHING FLOOD
STAGE THIS WEEKEND. THE LATEST RIVER FORECASTS HAVE CONTENTNEA
CREEK NEAR HOOKERTON RISING TO MINOR FLOOD STAGE BY LATE THIS
EVENING...THE NEUSE RIVER IN KINSTON SATURDAY AFTERNOON...AND THE
TAR RIVER AT GREENVILLE SATURDAY NIGHT. THE NE CAPE FEAR RIVER IS
EXPECTED TO CREST AT ACTION STAGE. A RIVER FLOOD WARNING MAY BE
ISSUED FOR CONTENTNEA CREEK NEAR HOOKERTON BY LATE THIS MORNING IF
THE LATEST RIVER FORECASTS CONTINUE TO INDICATE THE RIVER WILL
RISE ABOVE FLOOD STAGE.
&&
.CLIMATE...
RECORD BREAKING TEMPS EXPECTED THE REMAINDER OF CHRISTMAS WEEK.
THE FOLLOWING ARE RECORD HIGH MAX TEMPS, AS WELL AS RECORD HIGH
MIN TEMPS, FOR 12/24 THROUGH 12/27. ALSO INCLUDED ARE THE ALL-
TIME MAX HIGH, AND ALL-TIME MAX LOW TEMPS FOR DECEMBER.
RECORD HIGH MAX TEMPS F0R 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 76/1964 (KEWN ASOS)
CAPE HATTERAS 72/1990 (KHSE ASOS)
GREENVILLE 73/1988 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 72/1990 (COOP - NOT KMRH ASOS)
KINSTON 78/2013 (COOP - NOT KISO AWOS)
JACKSONVILLE 74/1990 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/24 THURSDAY
LOCATION TEMP/YEAR
NEW BERN 55/2014 (KEWN ASOS)
CAPE HATTERAS 62/1986 (KHSE ASOS)
GREENVILLE 56/1956 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/1956 (COOP - NOT KMRH ASOS)
KINSTON 63/1990 (COOP - NOT KISO AWOS)
JACKSONVILLE 54/2014 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 78/1955 (KEWN ASOS)
CAPE HATTERAS 73/1964 (KHSE ASOS)
GREENVILLE 77/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 74/1974 (COOP - NOT KMRH ASOS)
KINSTON 78/1932 (COOP - NOT KISO AWOS)
JACKSONVILLE 76/1974 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/25 FRIDAY
LOCATION TEMP/YEAR
NEW BERN 63/1964 (KEWN ASOS)
CAPE HATTERAS 61/1964 (KHSE ASOS)
GREENVILLE 59/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/2008 (COOP - NOT KMRH ASOS)
KINSTON 61/1932 (COOP - NOT KISO AWOS)
JACKSONVILLE 61/1987 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/26 SATURDAY
LOCATION TEMP/YEAR
NEW BERN 77/1987 (KEWN ASOS)
CAPE HATTERAS 74/1964 (KHSE ASOS)
GREENVILLE 77/1932 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 73/1982 (COOP - NOT KMRH ASOS)
KINSTON 77/1955 (COOP - NOT KISO AWOS)
JACKSONVILLE 82/1981 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/26 SATURDAY
LOCATION TEMP/YEAR
NEW BERN 65/1964 (KEWN ASOS)
CAPE HATTERAS 63/1964 (KHSE ASOS)
GREENVILLE 64/1932 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 60/1964 (COOP - NOT KMRH ASOS)
KINSTON 65/1964 (COOP - NOT KISO AWOS)
JACKSONVILLE 64/1964 (KNCA AWOS)
RECORD HIGH MAX TEMPS FOR 12/27 SUNDAY
LOCATION TEMP/YEAR
NEW BERN 74/1971 (KEWN ASOS)
CAPE HATTERAS 71/1982 (KHSE ASOS)
GREENVILLE 76/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 74/1982 (COOP - NOT KMRH ASOS)
KINSTON 77/1964 (COOP - NOT KISO AWOS)
JACKSONVILLE 71/1982 (KNCA AWOS)
RECORD HIGH MIN TEMPS FOR 12/27 SUNDAY
LOCATION TEMP/YEAR
NEW BERN 62/1949 (KEWN ASOS)
CAPE HATTERAS 62/1973 (KHSE ASOS)
GREENVILLE 62/1964 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 61/1949 (COOP - NOT KMRH ASOS)
KINSTON 62/1964 (COOP - NOT KISO AWOS)
JACKSONVILLE 60/1964 (KNCA AWOS)
**ALL-TIME RECORD HIGH MAXIMUM TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 83/1971 (KEWN ASOS)
CAPE HATTERAS 78/1991 (KHSE ASOS)
GREENVILLE 82/1998 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 79/1998 (COOP - NOT KMRH ASOS)
KINSTON 87/1918 (COOP - NOT KISO AWOS)
JACKSONVILLE 82/1998 (KNCA AWOS)
**ALL-TIME RECORD HIGH MINIMUM TEMPS FOR DECEMBER**
LOCATION TEMP/YEAR
NEW BERN 69/2013 (KEWN ASOS)
CAPE HATTERAS 68/2015 (KHSE ASOS)
GREENVILLE 67/1991 (COOP - NOT KPGV AWOS)
MOREHEAD CITY 67/2001 (COOP - NOT KMRH ASOS)
KINSTON 68/1991 (COOP - NOT KISO AWOS)
JACKSONVILLE 68/2013 (KNCA AWOS)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST FRIDAY FOR AMZ152-154-156-
158.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR AMZ150.
&&
$$
SYNOPSIS...SK
NEAR TERM...SK
SHORT TERM...SK
LONG TERM...RF/BTC
AVIATION...RF/SK
MARINE...RF/SK
HYDROLOGY...MHX
CLIMATE...MHX
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1010 PM CST WED DEC 23 2015
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
AND NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 945 PM CST WED DEC 23 2015
FORECAST APPEARS TO BE ON TRACK. PCPN WAS CHANGING OVER TO SNOW
IN THE FAR WEST LATE THIS EVG...AND GIVEN THAT THE ENHANCED
SE EDGE OF THE DEFORMATION ZONE (AND SOME EMBEDDED CONVECTION)
WILL TRACK RIGHT OVER VILAS/ONEIDA COUNTIES OVER THE NEXT 3 TO 4
HOURS...EXPECT SOME GOOD ACCUMS TO OCCUR THERE. SNOW SHOULD
DIMINISH QUICK ENOUGH TO PREVENT SIGNIFICANT ACCUMS SOUTH OF THE
WINTER WX ADVISORY AREA.
WIND ADVISORY IS LOOKING GOOD TOO. THE PRESSURE GRADIENT HAS
REALLY TIGHTENED UP OVER NE IA/NW IL AND SW WI LATE THIS
EVG...ALONG WITH AN INTENSE ISALLOBARIC GRADIENT. NUMEROUS
GUSTS TO 35 TO 45 KTS WERE OCCURRING IN THIS REGION...AND
THESE SHOULD TRANSLATE INTO THE SE HALF OF GRB CWA AS THE
COLD FRONT MOVES THROUGH AROUND THE MIDNIGHT HOUR. STILL
UNCERTAIN IF WE WILL SEE SUSTAINED WINDS TO 40 MPH OR GUSTS
OVER 58 MPH OVER DOOR COUNTY...ESPECIALLY GIVEN A SW-WSW WIND
DIRECTION. DECIDED TO KEEP THE HIGH WIND WARNING GOING...BUT
TONED DOWN THE WORDING SLIGHTLY IN THE STATEMENT.
UPDATE
ISSUED AT 550 PM CST WED DEC 23 2015
MADE SOME EARLIER ADJUSTMENTS TO POPS/WX TO ACCOUNT FOR DRY
SLOTTING THAT WAS OCCURRING. SHOWERS AND SCT TSTMS WILL FILL
BACK IN OVER THE REGION IN ASSOCIATION WITH THE ARRIVAL OF THE
POTENT NEGATIVELY-TILTED S/W TROF...SFC LOW AND COLD FRONT THIS
EVG. SBCAPE/MUCAPE HAS BEEN WANING THE PAST FEW HOURS...SO NOT
CONVINCED THAT WE WILL HAVE ANY SIGNIFICANT PROBLEMS WITH THE
CONVECTION LIFTING NE OUT OF NE IA/NW IL. NEVERTHELESS...WILL
KEEP A CLOSE EYE ON IT. SUSPECT THAT RAIN WILL RAPIDLY CHANGE TO
SLEET/SNOW OVER OUR FAR WESTERN COUNTIES BETWEEN 03Z-05Z...WITH
A PERIOD OF MODERATE SNOW EXPECTED OVER FAR NC WI DURING THE
LATE EVENING/EARLY OVERNIGHT HOURS. THUS...THE WINTER WX ADVISORY
FOR VILAS/ONEIDA COUNTIES LOOKS ON TARGET. GUSTY WINDS SHOULD
QUICKLY INCREASE LATE THIS EVG...IN THE WAKE OF THE COLD FRONTAL
PASSAGE. ADVISORY CRITERIA WINDS LOOK LIKE A GOOD BET...AT LEAST
IN THE FOX VALLEY/LKSHR AREAS. NOT SURE THAT WE WILL REACH
WARNING CRITERIA FOR DOOR COUNTY...BUT NOT PLANNING ANY CHANGES
TO THE HIGH WIND WARNING AT THIS TIME.
&&
.SHORT TERM...TONIGHT AND THURSDAY
ISSUED AT 309 PM CST WED DEC 23 2015
PLENTY OF FORECAST CHALLENGES NEXT 24 HOURS CONCERNING WITH GUST
POTENTIAL AND AMOUNT OF RAINFALL AND RAINFALL RATES WHICH MAY
IMPACT ANY LINGERING RIVER FLOOD PROBLEMS AS WELL AS PRODUCE ANY
SMALL STREAM URBAN FLOODING ISSUES. SEE THE HYDROLOGY SECTION
BELOW FOR THE LATEST DETAIL ON FLOODING ISSUES. OTHER ISSUES
CONCERN CHANGE OVER TO SNOW TONIGHT.
A STRONG SHORT WAVE LIFTS NORTHEAST OVER THE GREAT LAKES REGION
THROUGH TONIGHT. AN ASSOCIATED SURFACE LOW WILL TRACK FROM IOWA
LATE THIS AFTERNOON TO CENTRAL UPPER MICHIGAN AROUND MIDNIGHT AND
DEEPEN. THE LOW WILL ALSO A DRAG WARM FRONT OVER NORTHEAST
WISCONSIN THIS AFTERNOON INTO THIS EVENING. MILDER AIR SPREADING
INTO EAST CENTRAL AND FAR NORTHEAST WISCONSIN WILL ALLOW A VERY
MILD AIR MASS WITH POSSIBLE RECORD HIGHS TO INVADE THE AREA.
HIGHEST TOTAL TOTALS NUMBERS IN THE LOWER 50S MID EVENING AS PER
GRB BUFKIT DATA. THIS WILL ALSO RESULT IN A MORE UNSTABLE AIR
MASS AND MAY PROMOTE BETTER MIXING OF STRONG WINDS TO THE
SURFACE...ESPECIALLY WITH ANY CONVECTION. HRRR PROGGED DEVELOPMENT
OF THIS CONVECTION OF CONCERN ALONG AND AHEAD OF THE FRONT OVER
NORTHERN MO AND SOUTHERN IOWA AND SO FAR IS VERIFYING. THIS NEXT
ROUND IS PROGGED TO SWEEP OVER THE AREA THIS EVENING.
PROBLEM 2 WITH THE WINDS OCCUR LATE TONIGHT AS THE DEEPENING LOW
PRESSURE DEPARTS NORTHEAST AND LEAVES A STRONG PRESSURE GRADIENT
OVER MUCH OF THE STATE. A STRONG PRESSURE CHANGE COUPLET SLIDES
OVER NORTHEAST WISCONSIN IN THE WAKE OF THE SURFACE LOW. WILL
CONTINUE WITH THE WIND ADVISORY AND WILL ISSUE FOR DOOR DUE TO THE
WESTERLY COMPONENT. ITS POSSIBLE THE HIGH WIND ADVISORIES AND
WARNINGS MAY NEED TO BE EXPANDED DEPENDING ON THE LOW PRESSURE
TRACK.
PCPN TYPE INITIALLY NOT AN ISSUE BUT COULD SEE SOME HAIL OR
GRAUPEL WITH ANY CONVECTION THIS EVENING. LATER EVENING INTO THE
MORNING...COLDER AIR POURING IN WILL CHANGE THE PCPN TYPE TO
SNOW. WHILE SNOW RANGES MOSTLY IN THE 2-4 RANGES FOR NC WI...THE
SNOW WIND COMBO WARRANTS AN ADVISORY LATER TONIGHT. RADAR SOUTHERN
LOOP SUGGESTS REACHING NC WI AND CHANGEOVER AND ISSUE. BUT DID
NOTICE SOME THUNDER WITH THE SURFACE LOW OVER IOWA.
SYSTEM GRADUALLY DEPARTS THURSDAY WITH DIMINISHING WINDS IN THE
MORNING. TEMPERATURES NEAR STEADY ON THURSDAY.
.LONG TERM...THURSDAY NIGHT THROUGH WEDNESDAY
ISSUED AT 309 PM CST WED DEC 23 2015
AMPLIFIED MEAN FLOW TO REMAIN INTACT THRU THE END OF THE WORK WEEK
WITH AN ERN PACIFIC UPR RDG...WRN CONUS UPR TROF AND BERMUDA UPR
RDG. THE UPR TROF IS FCST TO CLOSE OFF INTO AN UPR LOW OVER WEST
TX THIS WEEKEND BEFORE LIFTING NE INTO THE GREAT LAKES EARLY NEXT
WEEK. PCPN CHCS WL BE FOCUSED FRI NGT/SAT ASSOCIATED WITH A TIGHT
BAROCLINIC ZONE/JET ENERGY AND MON NGT/TUE WITH THE UPR LOW/
ASSOCIATED SFC LOW. PCPN TYPE ISSUES WL ALSO BE A PROBLEM WITH
BOTH OF THESE SYSTEMS AS TEMPS FLUCTUATE BELOW FREEZING AT NGT AND
RISE ABOVE FREEZING IN PLACES DURING THE DAY. THERE IS SNOW
ACCUMULATION POTENTIAL FOR CNTRL/NRN WI FRI NGT AND OVER THE
ENTIRE AREA MON NGT/TUE.
A WEAK AREA OF HI PRES IS FCST TO APPROACH SRN SECTIONS OF THE
GREAT LAKES THU NGT AND SHOULD KEEP THE FCST AREA DRY. IT MAY TAKE
MOST OF THE NGT TO TRY AND SCOUR OUT LINGERING LOW/MID-LEVEL
MOISTURE...THUS PARTLY TO MOSTLY CLOUDY SKIES SHOULD SUFFICE. MIN
TEMPS TO RANGE FROM THE MID TO UPR TEENS NORTH...LWR 20S CNTRL...
AND MID TO UPR 20S E-CNTRL WI. THESE DRY CONDITIONS ARE EXPECTED
TO PERSIST THRU CHRISTMAS DAY AS THE SFC HI SLIDES EAST TOWARD THE
ERN GREAT LAKES. UNDER PARTLY CLOUDY SKIES AND RELATIVELY LIGHT
WINDS...LOOK FOR MAX TEMPS TO REACH THE LWR TO MID 30S NORTH...
MID TO UPR 30S SOUTH.
FCST CONFIDENCE DROPS RATHER QUICKLY LATE FRI NGT INTO SAT AS AN
UPR TROF DEEPENS OVER THE ROCKIES...INDIVIDUAL SHORTWAVES EJECT
OUT OF THIS TROF NEWD THRU THE CNTRL CONUS...A STALLED FRONTAL
BOUNDARY TO OUR SOUTH BECOMES MORE ACTIVE AND GULF MOISTURE LIFTS
NORTH ALONG THIS FRONTAL BOUNDARY TOWARD THE GREAT LAKES. MODELS
BRING THE LEADING EDGE OF PCPN INTO NE WI LATE FRI NGT WHEN TEMPS
WL BE COLD ENUF TO ALLOW PCPN TO FALL AS ALL SNOW. THE ISSUES FOR
SAT ARE WHERE THE HIGHEST QPF WL FALL AND WHAT THE PCPN TYPE WL
BE. THIS IS WHERE THE MODELS DIFFER AS THE GFS/ECMWF FOCUS THE
HEAVIER PCPN TO THE NORTH AND ALLOW FOR WARMER AIR TO LIFT FARTHER
NORTH INTO WI...THUS A MIXED PCPN EVENT FOR CNTRL/E-CNTRL WI WITH
SNOW NORTH. THE GEM IS FARTHEST SOUTH WITH THE HEAVIER PCPN (SRN
WI) AND COOLER AIR...THUS KEEPING ALL OUR PCPN AS ALL SNOW. THE
BETTER FRONTOGENETICAL FORCING SIGNAL AND LOCATION OF THE BEST
LIFT FROM THE RIGHT ENTRANCE REGION OF THE UPR JET FAVOR NRN WI
WITH THE HIGHER QPF...THUS WL CONT THE MENTION OF SNOW NORTH AND
SNOW BECOMING MIXED WITH RAIN FOR CNTRL/E-CNTRL WI. POTENTIAL SNOW
ACCUMULATION OF 3-5" IS POSSIBLE OVER THE NORTH FRI NGT INTO
SAT...BUT ANY WAVERING ON THE STRONGER LIFT/FORCING COUDL ALTER
THESE VALUES.
AS THE STRONGER DYNAMICS SHIFT TO THE EAST SAT NGT...MODELS
INDICATE CAA TO TAKE OVER ACROSS WI...THUS ANY LINGERING RAIN OVER
CNTRL OR E-CNTRL WI WL TRANSITION TO ALL SNOW. DO NOT ANTICIPATE
MUCH (IF ANY) ADDITIONAL ACCUMULATION SAT NGT AS MOST OF THE
MOISTURE TO HAVE BEEN SHUNTED EAST. A STRONG AREA OF HI PRES IS
FCST TO BUILD ACROSS THE UPR MS VALLEY ON SUNDAY AND SEND ENUF DRY
AIR INTO WI TO ALLOW SKIES TO BECOME AT LEAST PARTLY CLOUDY.
DESPITE THE CAA AND NORTH WINDS AT 5 TO 15 MPH...MAX TEMPS ARE
FCST TO REMAIN ABOVE NORMAL ON SUNDAY BY AROUND 5 DEGS (MID 20S
N-CNTRL TO LWR 30S E-CNTRL WI).
THE CORE OF THIS STRONG HI PRES IS PROGGED TO MOVE ACROSS WRN
ONTARIO SUNDAY NGT AND VEER THE WINDS TO THE NE. WL HAVE TO WATCH
FOR POTENTIAL OF LK EFFECT SNOW SHWRS FROM LK MI AS TEMPS/DELTA-T
VALUES WOULD SUPPORT THE DEVELOPMENT OF LIGHT SNOW. ONE NEGATIVE
IS THAT THE WINDS CONT TO VEER THRU THE NGT (FROM NORTH TO
E-NE)...THUS IT MAY PROVE DIFFICULT FOR SNOW BANDS TO FOCUS ON ANY
ONE PARTICULAR AREA. OTHERWISE...THE OTHER BIG STORY WL BE THE
APPROACH OF ANOTHER STRONG AREA OF LOW PRES/CLOSED UPR LOW INTO
THE MID-MS VALLEY ON MON. LATEST THINKING IS THAT THERE WL BE ENUF
DRY AIR ON GUSTY EAST WINDS FROM ONTARIO HI PRES TO DELAY THE
ONSET OF ANY PCPN INTO NE WI ON MON. HAVE REDUCED POPS AND WOULD
EXPECT ALMOST A COMPLETELY DRY DAY FOR MON WITH MAX TEMPS IN THE
UPR 20S TO LWR 30S.
MODELS CONT TO DIFFER WITH THE TIMING/EVENTUAL TRACK OF THIS
STRONG SYSTEM MON NGT INTO TUE WITH THE GFS/GEM FAVORING A
QUICKER/FARTHER EAST TRACK VERSUS THE SLOWER/FARTHER WEST TRACK OF
THE ECMWF. THE GFS/GEM SOLUTION WOULD PROVIDE A QUICK-HITTING SNOW
EVENT FOR MAINLY THE SE HALF OF WI MON NGT BEFORE PULLING AWAY ON
TUE. THE ECMWF SOLUTION WOULD BRING A SWATH OF SNOW ACROSS ALL
OF NE WI MON NGT BEFORE MIXING IN RAIN OVER CNTRL/E-CNTRL WI ON
TUE WITH ADDITIONAL SNOWS FOR NRN WI. IF THE ECMWF SOLUTION
PREVAILS...WE WOULD BE LOOKING AT HEADLINES FOR SNOW...HOWEVER
THERE IS TOO MUCH UNCERTAINTY YET SO HAVE FOLLOWED A MODEL BLEND
FOR NOW WITH HIGHER CHC POPS IN THE FCST FOR BOTH MON NGT AND TUE.
EVEN GOING INTO WED...THERE IS MODEL DISAGREEMENT WITH RESPECT TO
THE TRACK OF THE SECONDARY/WEAKER UPR LOW THAT WOULD LIFT NE INTO
THE REGION. SINCE MODELS ARE INCONSISTENT WITH THIS
FEATURE...PREFER TO KEEP THE FCST DRY FOR NOW...BUT WOULD EXPECT
SOME SMALL POPS TO BE ADDED AS WE GET CLOSER TO WED.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 945 PM CST WED DEC 23 2015
A STEADY RAIN WAS CHANGING TO SNOW OVER NC/C WI LATE THIS EVG.
MODERATE SNOW WILL LIKELY OCCUR OVER FAR NC WI...INCLUDING THE
RHI TAF SITE...FOR THE FIRST COUPLE HOURS OF THE TAF PERIOD.
FARTHER EAST...SHOWERS AND ISOLD TSTMS WILL TAPER OFF
OVERNIGHT...AND SHOULD END AT GRB/ATW/MTW BEFORE THE AIR MASS IS
COLD ENOUGH TO SUPPORT SNOW. FLIGHT CONDITIONS SHOULD IMPROVE
TO MVFR/VFR AS THE PCPN ENDS OVERNIGHT.
STRONG GUSTY SW-W WINDS WILL DEVELOP IN THE WAKE OF A COLD
FRONTAL PASSAGE...AND CONTINUE THROUGH THURSDAY MORNING BEFORE
DIMINISHING. GUSTS AS HIGH AS 35 TO 45 KTS ARE EXPECTED IN THE
FOX VALLEY/LKSHR AREAS.
&&
.MARINE...
ISSUED AT 309 PM CST WED DEC 23 2015
HIGH-END GALES ARE STILL LIKELY WITH THIS STORM....BUT WILL
MENTION STORM FORCE WIND GUSTS. IN ADDITION WILL ALSO MENTION A
PERIOD OF FOG THOUGH THE EVENING HOURS.
&&
.HYDROLOGY...
ISSUED AT 309 PM CST WED DEC 23 2015
MOST RIVERS HAVE RECOVERED FROM THE HEAVY RAINS OVER A WEEK
AGO...EXCEPT FOR THE LOW LYING AREAS ALONG THE WOLF RIVER SOUTH OF
SHAWANO TO LAKE POYGAN. WITH THIS RAINFALL EXPECTED TO BE IN A
SHORTER TIME FRAME...AN INCH OF RAIN COULD PRODUCE ENOUGH RUN OFF
FOR SOME MINOR URBAN SMALL STREAM FLOODING. THIS WOLF RIVER LEVELS
MAY HOLD STEADY FOR A FEW MORE DAYS WITH THIS ADDITIONAL RAINFALL.
BUT LATEST RADAR TRENDS SUGGEST SOME DRY SLOTTING AS AN AREA OF
ELEVATED CONVECTION IS SWEEPING NORTHEAST OF THE AREA...WITH THE
NEXT ROUND OF CONVECTION APPROACHING FROM IOWA. AS A RESULT RAIN
AMOUNTS TO BE LESS ROUGHLY FORM 0.30 TO 0.50. SEE
WEATHER.GOV/AHPS FOR AVAILABLE FORECASTS FOR NORTHEAST WISCONSIN
RIVERS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL NOON CST THURSDAY FOR WIZ020-021-031-037>040-
045-048>050-073-074.
HIGH WIND WARNING UNTIL NOON CST THURSDAY FOR WIZ022.
WINTER WEATHER ADVISORY UNTIL 4 AM CST THURSDAY FOR WIZ005-010.
&&
$$
UPDATE.........KIECKBUSCH
SHORT TERM.....TDH
LONG TERM......AK
AVIATION.......KIECKBUSCH
MARINE.........TDH
HYDROLOGY......TDH
AREA FORECAST DISCUSSION
NWS RENO NV
329 AM PST THU DEC 24 2015
.SYNOPSIS...
A COLD FAST MOVING STORM WILL BRING PERIODS OF HEAVY SNOW AND SNOW
SHOWERS TO THE SIERRA AND WESTERN NEVADA TODAY AND TONIGHT. SNOW
COVERED ROADS AND BLOWING SNOW ARE LIKELY FOR MUCH OF THE REGION.
COLD CONDITIONS ARE ON TAP FOR CHRISTMAS DAY INTO THE WEEKEND.
WHILE MOST OF NEXT WEEK APPEARS DRY WITH A SLOW WARMING TREND, ONE
OR TWO WEAK STORMS MAY IMPACT THE AREA WITH LIGHT PRECIPITATION.
&&
.SHORT TERM...
RAISED WINDS SLIGHTLY FOR THE HIGHWAY 395 CORRIDOR NEAR AND SOUTH
OF HIGHWAY 203 (MAMMOTH LAKES) THIS AFTERNOON, OTHERWISE MINIMAL
CHANGE TO THE SHORT TERM FORECAST. ALL WARNINGS AND ADVISORIES FOR
TODAY STILL LOOK ON TRACK.
LOOKING AT THE INFRARED AND WATER VAPOR SATELLITES, THE UPPER JET
CORE HAS DROPPED INTO CENTRAL CALIFORNIA/SOUTHERN NEVADA (DRY SLOT
IN WATER VAPOR) WITH COLDER CLOUD TOPS MOVING INTO NORTHERN
CALIFORNIA AND NORTHWEST NEVADA AHEAD OF THE UPPER LOW CORE OFF
THE OREGON COAST. THERE WAS CLOUD-TO-GROUND LIGHTNING WITH THE
MAIN BAND AS IT MOVED ASHORE NEAR ARCATA, CA A FEW HOURS AGO,
INDICATIVE OF THE INSTABILITY AND CONVECTIVE NATURE OF THE COLD
LOW (100-250 J/KG OF CAPE NEAR COAST PER 10Z SPC MESOANALYSIS).
WIDESPREAD SHOWERS OVER NORTHERN CALIFORNIA WILL CONTINUE TO DRIVE
SOUTH AND EAST THIS MORNING, WITH THE 09Z HRRR BRINGING SNOW AND
SNOW SHOWERS TO ALL OF THE NORTHERN SIERRA AND WESTERN NEVADA (TO
ABOUT HIGHWAY 50) BETWEEN ~5-9 AM. SHOWERS WILL SPREAD SOUTH OVER
EASTERN MONO AND MINERAL COUNTIES THIS AFTERNOON. THERE COULD BE
A WIDE RANGE OF SNOWFALL TOTALS THROUGH THIS AFTERNOON, ESPECIALLY
EAST OF THE SIERRA, AS LOCALIZED HEAVY SNOW BANDS DEPOSIT IN SOME
AREAS AND NOT OTHERS. LAKE EFFECT SNOW IS ALSO LIKELY TO BRING
SOME LOCALLY HIGHER AMOUNTS DOWNWIND OF LAKE TAHOE AND EVENTUALLY
(~LATE AFTERNOON) PYRAMID LAKE TODAY. IN FACT, THERE ARE SIGNS
THAT LAKE TAHOE IS ALREADY FIRING UP SOME LAKE EFFECT SNOW NEAR
AND NORTH OF HIGHWAY 50 IN FAR WESTERN NEVADA.
BRIEFLY TURNING TO WINDS, THEY SHOULD GUST MAINLY INTO THE 25-35 MPH
RANGE TODAY AHEAD OF THE PRECIPITATION BAND. HOWEVER, LOCAL GUSTS
OF 40-50 MPH ARE POSSIBLE IN WIND PRONE AREAS ALONG HIGHWAY 395
SOUTH OF RENO THROUGH MONO COUNTY AND OUT INTO FAR WESTERN MINERAL
AND SOUTHERN LYON COUNTIES.
THE MAIN AREA OF SNOW SHOWERS DROPS SOUTH OF I-80 THIS EVENING,
ALTHOUGH RESIDUAL SHOWERS ARE POSSIBLE THROUGH TONIGHT ESPECIALLY
DOWNWIND OF PYRAMID LAKE AND PERHAPS LAKE TAHOE (THIS EVENING
ESPECIALLY). THE NAM HAS FINALLY BACKED OFF ON A SECOND SHOT OF
SNOW FOR CHURCHILL AND PERSHING COUNTIES TONIGHT, MORE IN LINE
WITH OTHER MODELS. ANY SNOW ACCUMULATIONS TONIGHT SHOULD REMAIN
LIGHT FOR WESTERN NEVADA, EXCEPT DOWNWIND OF PYRAMID LAKE WHERE
SEVERAL INCHES CANNOT BE RULED OUT. FOR THE SIERRA, WESTERN MONO
AND ALPINE COUNTIES COULD SEE ANOTHER 4-8 INCHES TONIGHT AS
UNSTABLE, MOIST UPSLOPE FLOW PUSHES SNOW ACROSS THE CREST INTO THE
EASTERN SIERRA.
CHRISTMAS DAY THROUGH THE WEEKEND WILL REMAIN COLD UNDER NORTH-
EAST FLOW AS THE TROUGH SLOWLY EXITS. LOWS WILL WE QUITE COLD BY
FRIDAY NIGHT AS CLEARING WORKS INTO THE REGION, WITH BELOW ZERO
READINGS LIKELY FOR THE COLDER, SNOW-COVERED VALLEYS OF WESTERN
NEVADA (OUTSIDE MAIN URBAN AREAS) AND CERTAINLY FOR THE SIERRA
VALLEYS. VALLEY INVERSIONS SHOULD BECOME QUITE STRONG BY SATURDAY
AND SATURDAY NIGHT AS A RIDGE BUILDS OVERHEAD. SNYDER
.LONG TERM...SUNDAY THROUGH WEDNESDAY...
FEW CHANGES MADE TO THE LONG TERM AS THE MODELS AND ENSEMBLES DEPICT
A MEAN RIDGE DEVELOPING ALONG THE COAST. THEY STILL DEPICT WEAK
WAVES MOVING THROUGH THE RIDGE OR DROPPING DOWN THE EAST SIDE INTO
THE MIDDLE OF NEXT WEEK. THE MONDAY SYSTEM LOOKS TO BE THE
STRONGEST, BUT IT REALLY IS QUITE WEAK OVERALL. THE MAIN DIFFERENCES
IN THE MODELS ARE THAT THE GFS IS A BIT FURTHER EAST WITH THE RIDGE
AND HAS THE SYSTEMS THAT DROP DOWN FROM THE NORTH INTO EASTERN
NEVADA. THE EC HAS THEM DROPPING INTO WESTERN NEVADA LIKE INSIDE
SLIDERS. HAVE USED A BLEND OF ALL GUIDANCE AS TRACKING THESE
INDIVIDUAL WAVES IS FUTILE AT BEST 5-7 DAYS OUT.
SUNDAY WILL STILL BE COLD IN THE VALLEYS UNDER A STRONG INVERSION
WHILE MTNS WARM. WITH THE MONDAY SYSTEM, THE BEST CHANCE OF SNOW
SHOWERS LOOKS TO BE IN THE SIERRA FROM TAHOE NORTH AND ALONG THE
OREGON BORDER. IT WILL ALSO HELP TO IMPROVE MIXING A BIT WITH COOLER
TEMPS ALOFT. TUESDAY AND WEDNESDAY, TWO MORE WEAK SYSTEMS WILL DROP
IN FROM THE NORTH. FOR NOW, HAVE KEPT IN A SLIGHT CHANCE OF SHOWERS
FOR TUESDAY ACROSS THE NORTH AND LEFT WEDNESDAY DRY. HAVE GONE WITH
A SLOW WARMING TREND, ESPECIALLY IN THE MOUNTAINS DUE TO BETTER
MIXING. HOWEVER, IF THERE IS ENOUGH SNOW COVER LEFT BY WEDNESDAY IN
WRN NV VALLEYS, THEY COULD BE TRAPPED UNDER A STRONG INVERSION
AGAIN. WALLMANN
&&
.AVIATION...
MAIN CONCERN IS THE SHSN MOVING THROUGH THE SIERRA AND WESTERN
NEVADA TODAY. IFR CONDS THRU 21-00Z FOR KTRK/KTVL THEN SOME MVFR
CONDS THRU 06Z BEFORE IMPROVING. KRNO/KCXP 2-3 HR PERIOD OF IFR
CONDS BETWEEN 15-20Z WITH OCNL MVFR 20-01Z IN -SHSN. KMMH IFR
CONDS 18-01Z THEN GRADUALLY IMPROVING AS WELL. RUNWAY ACCUMS STILL
LOOK TO BE AROUND 6" KTRK/KTVL 2-4" KRNO/KCXP AND 4-6" FOR KMMH.
EXPECT ALL TERMINALS VFR AFTER 09Z FRI.
OTHER CONCERN IS WINDS WITH RIDGE GUSTS 60 KTS ATTM. SOME LLWS THIS
MORNING THRU 15-17Z BEFORE SNOW COMMENCES AND WINDS CLOSER TO
SURFACE ABATE. OTHERWISE SFC WND GUSTS TO 25 KTS MOST LIKELY AT ALL
TERMINALS FROM S-SW THRU 03Z. EXCEPTION WILL BE KMMH WHERE WNW FLOW
ALOFT ALIGNS BETTER AND PEAK GUSTS TO 40-45 KTS POSSIBLE 15-03Z.
WALLMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ005.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 10 PM PST THIS
EVENING NVZ001-003-004.
CA...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ071-072.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING CAZ070.
WINTER STORM WARNING FROM 10 AM THIS MORNING TO 4 AM PST FRIDAY
CAZ073.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1010 AM EST THU DEC 24 2015
.SYNOPSIS...
LOW PRESSURE MOVING THROUGH CANADA WILL DRAG A COLD FRONT ACROSS
THE REGION TODAY. THE FRONT WILL SLOWLY SAG SOUTH OF THE REGION
LATE TONIGHT...AND TOWARDS THE MID ATLANTIC STATES ON CHRISTMAS
AS HIGH PRESSURE BUILDS IN FROM THE NORTH. UNSETTLED WEATHER WILL
RETURN FOR THE WEEKEND AND INTO NEXT WEEK AS A SERIES OF STORM
SYSTEMS MOVE ACROSS.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BREEZY AND INCREDIBLY WARM DAY TODAY IS EXPECTED (ABOUT 30
DEGREES ABOVE SEASONABLE).
PHASED SHORTWAVE PIVOTS INTO QUEBEC TODAY...WHILE DEEP TROUGHING
RE-ESTABLISHES ACROSS THE WESTERN US THROUGH TONIGHT.
MEANWHILE...BERMUDA RIDGING REMAINS IN CONTROL TO THE
EAST...CONTINUING THE DEEP SW FLOW INTO THE REGION.
AT THE SURFACE...LOW PRESSURE CONTINUES TO TRACK TO HUDSONS BAY
TODAY...WITH ITS WEAKENING TRAILING COLD FRONT APPROACHING THE
REGION LATE TODAY INTO THIS EVENING. HIGHER RES MODELS INDICATING
POTENTIAL FOR A PRE-FRONTAL TROUGH DEVELOPING ACROSS WESTERN
PORTIONS OF THE TRI-STATE THIS AFTERNOON.
PATCHY OR AREAS OF FOG...MAINLY ALONG NEARSHORE LOCATIONS...COULD
HOLD WITH POOR VISIBILITIES INTO THE AFTERNOON WITH MARINE LAYER.
AWAY FROM MARINE INFLUENCE...RAPID IMPROVEMENT IN VSBY HAS BEEN
OBSERVED.
HIGH-RES NCAR ENSEMBLE AND HRRR DOING A FAIRLY GOOD JOB OF
PICKING UP ON SHOWER ACTIVITY ON NOSE OF DEVELOPING 55-60 KT LLJ.
THIS ACTIVITY AND REMNANTS OF PA CONVECTIVE LINE SHOULD TRANSLATE
FROM SW TO NE THROUGH THE COASTAL REGION LATE THIS MORNING INTO
EARLY AFTERNOON AHEAD OF A PRE-FRONTAL TROUGH. THUNDER HAS BEEN
OBSERVED JUST TO THE SOUTH. MARGINAL INSTABILITY (POTENTIALLY
SURFACE BASED ACROSS NE NJ/LOWER HUD) STILL EXISTS...BUT NOT MUCH
FORCING OR CONVERGENCE WITH THE APPROACHING COLD FRONT. SO SHOWER
POTENTIAL APPEARS TO BE LOW CHANCE TO SLIGHT...WITH LOW CONFIDENCE
ON ANY THUNDER BASED ON THE WEAK FORCING. BETTER CHANCE OF THUNDER
LOOKS TO BE SOUTH OF THE TRI- STATE. BASED ON WIND PROFILE...GUSTY
WINDS OF 40+ MPH COULD ACCOMPANY ANY HEAVY SHOWER OR TSTM
ACTIVITY.
IN TERMS OF WINDS TODAY...950 HPA WINDS OF 35 TO 40 KT ARE
EXPECTED...BUT MIXING IS THE CHALLENGE IN FORECASTING WIND
SPEEDS. SUSTAINED SE WINDS OF 10 TO 20 MPH WITH PEAK WINDS GUSTS
OF 25 TO 30 MPH LIKELY CONTINUE INTO EARLY
AFTERNOON...PARTICULARLY CITY/COAST. IF WE DO SEE SOME BREAKS OF
SUN AND RESULTANT INCREASED MIXING...SUSTAINED WINDS OF 20 TO 25
MPH AND GUSTS 35 TO 40 MPH ARE POSSIBLE AWAY FROM MARINE
INFLUENCE. THIS IS A LOW PROB...ESPECIALLY GIVEN SATELLITE TRENDS.
MAX TEMPS WILL REMAIN A CHALLENGE THIS AFTERNOON. LOW SUN
ANGLE...ABUNDANT CLOUD COVER...AND MIXING LIMITED TO 950
HPA...WILL LIMIT POTENTIAL HEATING. BUT RECORD TEMPS IN THE UPPER
60S TO LOWER 70S ARE EXPECTED FOR MOST OF THE REGION. A LOW
POTENTIAL FOR MID TO UPPER 70S NYC/NJ METRO...IF BREAKS OF SUN ARE
REALIZED.
TONIGHT...MODELS HAVE TRENDED SLOWER WITH COLD FRONTAL PASSAGE.
WITH MODELS SIGNALING WEAK DAYTIME CONVECTION INDUCED VORTS
TRACKING IN THE SW FLOW ALOFT...WITH LINGERING SHOWER THREAT
ACROSS NYC/NJ METRO AND LONG ISLAND INTO THE OVERNIGHT.
OTHERWISE...UNSEASONABLY MILD CONDITIONS EXPECTED TO CONTINUE WITH
LOWS GENERALLY IN THE 50S CITY/COAST AND 40S INTERIOR. LIGHT NW
FLOW EXPECTED IN THE WAKE OF THE FRONT...WITH SOME DRIER AIR
TRYING TO ADVECT IN. AMOUNT OF CLOUD COVER ALOFT WILL DETERMINE
DENSE FOG COVERAGE...BUT POTENTIAL EXISTS FOR AT LEAST PATCHY
DENSE FOG.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
MODELS COMING INTO BETTER AGREEMENT WITH CHRISTMAS INTO SATURDAY
PERIOD...WITH TROUGHING CONTINUING TO DEEPEN INTO THE SW US AND
BERMUDA HIGH SLOWLY DRIFTING SW TOWARDS FLORIDA. THIS WILL
CONTINUE TO PLACE THE REGION UNDER A DEEP SW PAC/SUB TROPICAL
FLOW.
AT THE SURFACE...APPEARS TO BE BETTER AGREEMENT WITH WEAK RIDGING
BUILDING INTO THE REGION ON CHRISTMAS DAY...PUSHING TODAYS COLD
FRONT TO THE MID ATLANTIC. THE SUBSIDENCE AND LOW-MID LEVEL
DRYING SHOULD PRESENT A DRY...AND ANOTHER RECORD BREAKING WARM
DAY. A PERIOD OF MOSTLY SUNNY SKIES LIKELY AFTER MORNING
STRATUS/FOG BURN OFF AND BEFORE HIGH CLOUD START TO STREAM IN IN
THE AFTERNOON.
MODELS CONVERGING ON AN INCREASING CHANCE FOR RAIN FRIDAY NIGHT INTO
SAT. AS THE WESTERN TROUGH APPROACHES THE CENTRAL US...DECENT
AGREEMENT IN A SERIES OF LOW PRESSURE WAVES BEGIN TO DEVELOP FROM
THE GULF COAST UP THE MISSISSIPPI RIVER VALLEY...LIFTING THE WARM
FRONT ACROSS THE MID-ATLANTIC UP TOWARDS THE REGION. POTENTIAL
FOR A FEW PERIODS OF LIGHT TO MODERATE RAIN AS SERIES OF WEAK
WAVES RIDE ALONG THE WARM FRONT INDUCED BY SOUTHERN STREAM
ENERGIES ROUNDING THE RIDGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS DIFFER WITH THE POSITION AND TIMING OF A SERIES OF FRONTAL
PASSAGES AND LOW PRESSURE SYSTEMS ASSOCIATED WITH THEM...BUT
GENERALLY A MILD AND UNSETTLED PATTERN. MONDAY HAS THE BEST
CHANCE OF REMAINING DRY AS HIGH PRESSURE BUILDING IN FROM THE
NORTH WOULD APPEAR TO BE STRONG ENOUGH TO SUPPORT IT. TUESDAY HAS
THE BEST CHANCE OF SEEING PCPN...BUT WILL CAP POPS AT CHC DUE TO
THE UNCERTAINTY. FOR LATE MONDAY NIGHT INTO TUESDAY
MORNING...THERMAL PROFILES COULD SUPPORT A WINTRY MIX FOR THE
NORTHERN FRINGE ZONES.
TEMPERATURES THROUGH THE LONG TERM MAINLY WARMER THAN NORMAL.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
A WARM FRONT JUST NORTH OF THE REGION WILL PUSH NORTH THROUGH THE
MORNING AS SOUTHWESTERLY WIND INCREASES TO 10 TO 15 KT WITH GUSTS
TO AROUND 20 KT.
A COLD FRONT ACROSS WESTERN PENNSYLVANIA WILL APPROACH FROM THE WEST
THIS AFTERNOON...WILL MOVE THROUGH THE TERMINALS LATE THIS AFTERNOON
INTO EARLY THIS EVENING.
AT THE NYC METRO TERMINALS VFR CONDITIONS ARE EXPECTED MUCH OF THE
TIME UNTIL THIS AFTERNOON. HOWEVER...CONDITIONS ARE VARYING AND AT
TIMES MVFR CEILINGS...AND MAYBE IFR...WILL BE POSSIBLE. OUTSIDE THE
METRO TERMINALS VARIABLE CONDITIONS FROM MVFR TO VFR LIKELY.
AT THIS TIME VFR CONDITIONS ARE EXPECTED TO PREDOMINATE WITH
MVFR POSSIBLE AT TIMES UNTIL LATER THIS AFTERNOON.
WITH THE UNCERTAINTY AND VARIABILITY IN THE FORECAST
CONFIDENCE IS LOW.
LOW LEVEL JET WINDS AT 2KFT EXPECTED TO BE SW AT 40-45 KT THROUGH
THE MORNING AND INTO EARLY AFTERNOON.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: ANY SOUTH TO SOUTHWEST WIND GUSTS ARE EXPECTED
TO BE INTERMITTENT. VFR MOST OF THE TIME INTO THIS AFTERNOON WITH
MVFR CEILINGS AND A LOW CHANCE OF MVFR IN FOG.
KLGA FCSTER COMMENTS: VFR MOST OF THE TIME WITH A CHANCE OF MVFR
CEILINGS THIS MORNING. VISIBILITIES RESTRICTIONS ARE NOT EXPECTED
UNTIL THIS AFTERNOON. SOUTHWESTERLY GUSTS 20-25KT INTO THIS AFTERNOON.
KEWR FCSTER COMMENTS: VFR MOST OF THE TIME WITH A CHANCE OF MVFR
CEILINGS THIS MORNING. VISIBILITIES RESTRICTIONS ARE NOT EXPECTED
UNTIL THIS AFTERNOON. SOUTHWESTERLY GUSTS 20-25KT INTO THIS
AFTERNOON.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 3-5SM OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: VFR MOST OF THE TIME WILL A CHANCE OF MVFR
CEILINGS...MAINLY THIS MORNING. VISIBILITIES RESTRICTIONS ARE NOT
EXPECTED UNTIL THIS AFTERNOON. SOUTHWESTERLY GUSTS AROUND 20 KT
BECOME MORE FREQUENT LATER THIS MORNING...AND CONTINUE INTO THIS
AFTERNOON.
KHPN FCSTER COMMENTS: MVFR CONDITIONS ARE EXPECTED TO IMPROVE TO VFR
LATER THIS MORNING AS A WARM FRONT MOVES FARTHER TO THE NORTH. THEN
AT TIMES MVFR CEILINGS WILL BE POSSIBLE...WITH A CHANCE OF IFR
CEILINGS INTO THIS AFTERNOON. LOW FORECAST CONFIDENCE.
KISP FCSTER COMMENTS: CURRENTLY...IFR CEILINGS WITH MVFR
VISIBILITIES IN FOG...MAY IMPROVE BRIEFLY TO VFR THIS MORNING. LOW
CONFIDENCE. GUSTS MAY NOT BE AS FREQUENT AS INDICATED IN THE TAF.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY...IFR POSSIBLE IN THE MORNING...MAYBE INTO THE AFTERNOON.
.SATURDAY-SUNDAY...MVFR OR LOWER POSSIBLE IN -RA.
.MONDAY...SLIGHT CHANCE OF -SHRA WITH MVFR OR LOWER.
&&
.MARINE...
WITH PROLONGED SOUTHERLY FETCH...SEAS ON THE OCEAN WILL STAY
ELEVATED. SCA REMAINS IN EFFECT THERE AS WINDS TOO HAVE BEEN GUSTING
TO 25-30 KT. OCCASIONAL GUSTS TO 25 KT ON REMAINDER OF WATERS.
THE WINDS WILL LOWER TONIGHT AND FRIDAY WHILE OCEAN SEAS WILL
LIKELY STAY ELEVATED WITH CONTRIBUTING SWELL.
WITHOUT MUCH OFFSHORE FLOW IN THE FORECAST...THE HIGHER OCEAN SEAS
MAY VERY WELL LINGER INTO THIS WEEKEND. HOWEVER GOING INTO THE
WEEKEND...FORECAST OCEAN WAVE HEIGHTS ARE MORE MARGINAL FOR
SCA...RIGHT AROUND 5 FT FRIDAY NIGHT THROUGH SATURDAY NIGHT.
WITH ABUNDANT LOW-LEVEL MOISTURE OVER THE WATERS...WIDESPREAD
DENSE FOG WILL CONTINUE THROUGH THE DAY. THE DENSE FOG ADVISORY HAS
BEEN EXTENDED TO 6 PM FOR MOST WATERS.
WINDS WILL EVENTUALLY INCREASE...BUT GUSTS TO 25KT APPEAR TO
BE LIMITED TO MAINLY THE OCEAN SUNDAY NIGHT AND MONDAY. THERE IS A
CHANCE THAT 25KT GUSTS OCCUR ON THE EASTERN SOUND AS WELL.
&&
.HYDROLOGY...
ADDITIONAL LIGHT TO MODERATE RAINFALL POSSIBLE THIS WEEKEND. A
SIGNIFICANT RAINFALL IS POSSIBLE EARLY NEXT WEEK.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR DECEMBER 24TH HAVE ALREADY BEEN SET AT
MOST OF THE CLIMATE SITES SO FAR. SEE BELOW FOR THE HIGHS SO FAR AND
THE FINAL HIGH TEMPERATURES WE ARE FORECASTING LATER TODAY.
LOCATION HIGH YEAR FORECAST
NEWARK 70 2015 75
BRIDGEPORT 61 2015 66
CENTRAL PARK 70 2015 74
LAGUARDIA 69 2015 73
KENNEDY 61 2015 69
ISLIP 62 2015 66
HERE ARE THE HIGH TEMPERATURE RECORDS AND FORECAST HIGHS
FOR DECEMBER 25...CHRISTMAS DAY...
LOCATION HIGH YEAR FORECAST
NEWARK 69 1964 67
BRIDGEPORT 59 1964 63
CENTRAL PARK 64* 1982 66
LAGUARDIA 63 2014 66
KENNEDY 58 1982 65
ISLIP 56 2014 64
*ALSO OCCURRED IN PREVIOUS YEARS
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ338.
DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-335-
340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...NV
NEAR TERM...NV/PW
SHORT TERM...NV/PW
LONG TERM...JC
AVIATION...JM/MET
MARINE...JM/PW
HYDROLOGY...NV
CLIMATE...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
724 AM EST THU DEC 24 2015
.SYNOPSIS...
UNUSUALLY WARM DECEMBER WEATHER WILL CONTINUE FOR THE NEXT FEW
DAYS...PROBABLY BREAKING MANY RECORDS. WET WEATHER WILL ACCOMPANY
THE WARMTH THIS WEEKEND. FOR NEXT WEEK...LOOKING AT AN ACTIVE
WEATHER PATTERN WITH THE POTENTIAL FOR A WINTRY MIX AT TIMES.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
724 AM UPDATE...
FORECAST REMAINS LARGELY ON TRACK THIS MORNING. MADE SOME TWEAKS
TO REFLECT OBSERVED TRENDS. AREAS OF FOG THIS MORNING. LOOKS LIKE
WE SHOULD SEE ONE MORE ROUND OF SHOWERS ALONG THE SOUTH COAST
LATER THIS MORNING. LATEST RUNS OF THE HRRR APPEAR TO HAVE A GOOD
HANDLE ON THIS.
PREVIOUS DISCUSSION...
HEAVY RAIN HAS MOVED OFFSHORE WHILE THE WARM FRONT CONTINUES TO
SURGE NORTHWARD. WARM FRONT HAS CREPT INTO PARTS OF RHODE ISLAND
AND SOUTHEASTERN MASSACHUSETTS WHERE TEMPERATURES HAVE SOARED INTO
THE UPPER 50S TO MID 60S! VERY HUMID AIR IS ACCOMPANYING THE FRONT
WITH DEWPOINTS IN THE SAME RANGE. BOTH TEMPERATURES AND DEWPOINTS
ARE HIGHLY ANOMALOUS FOR LATE DECEMBER. DEPENDING ON THE NORTHWARD
PROGRESSION OF THE WARM FRONT...WE MAY ACTUALLY HAVE NEAR RECORD
HIGH TEMPERATURES PRIOR TO SUNRISE FOR A FEW LOCATIONS.
IT IS A NEAR CERTAINTY THAT WE WILL HIT RECORD HIGHS TODAY ACROSS
SOUTHERN NEW ENGLAND AS 925MB TEMPS REACH 16C. AND THIS DESPITE
SHOWERS AND OVERCAST SKIES. IF WE WERE TO BREAK OUT INTO SOME
SUN...TEMPS COULD HIT THE LOW TO MID 70S. SINCE WE ARE EXPECTING
CLOUD COVER TO LINGER THROUGHOUT THE DAY...HIGHS WILL ONLY REACH THE
UPPER 60S TO AROUND 70. ONLY BEING RECORD SHATTERING TEMPERATURES.
THE NEXT ROUND OF SHOWERS WILL MOVE INTO SOUTHERN NEW ENGLAND LATER
THIS MORNING AND CONTINUE THROUGH THE AFTERNOON. THIS ROUND WILL BE
MUCH MORE SCATTERED IN NATURE THAN THE RAIN YESTERDAY AND LAST
NIGHT. PATCHY FOG SHOULD LIFT BY MID MORNING...EXCEPT OVER THE CAPE
AND ISLANDS WHERE IT IS LIKELY TO LINGER THROUGH MUCH OF THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
TONIGHT...THE COLD FRONT WILL MOVE THROUGH MUCH OF SOUTHERN NEW
ENGLAND STALLING ALONG THE SOUTH COAST. THIS WILL ALLOW LOW
CLOUDS...FOG...AND EVEN A FEW SHOWERS TO LINGER ON THE SOUTH COAST.
OTHERWISE...EXPECT GRADUALLY CLEARING SKIES AND CONTINUED MILD
TEMPERATURES. LOW TEMPS ARE EXPECTED TO BE IN THE MID 40S TO MID
50S.
CHRISTMAS DAY...ONE OF THE QUIETER DAYS THIS WEEK AS HIGH PRESSURE
BUILDS INTO SOUTHERN NEW ENGLAND. THE MODELS DISAGREE ON WHETHER
THE FRONT REMAINS STALLED ALONG THE SOUTH COAST. THE NAM IS THE
FARTHEST NORTH WITH THE FRONT AND KEEPS LOW CLOUDS AND PERHAPS SOME
SHOWERS ALONG THE SOUTH COAST. HOWEVER...THE GFS AND ECMWF BOTH
PUSH THE FRONT OFFSHORE. SO KEEPING THE CLOUDS ALONG THE SOUTH
COAST...BUT LIMITING THE POPS. EXPECT MAINLY DRY WEATHER WITH
ANOTHER DAY OF WELL ABOVE NORMAL TEMPERATURES. THE RECORD HIGH FOR
PROVIDENCE MIGHT BE TIED OR EXCEEDED WITH CURRENT FORECAST
HIGHS...HOWEVER THE REMAINDER OF THE CLIMATE SITES RECORDS WILL
LIKELY REMAIN SAFE.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
*/ HIGHLIGHTS...
- PERIODS OF WET WEATHER AND BREEZY WINDS FOR THIS WEEKEND
- POTENTIAL SERIES OF WINTER WEATHER STORMS NEXT WEEK
*/ OVERVIEW...
RATHER UNIFIED FLOW ALOFT EXPECTED TO BREAK UP INTO TWO SEPARATE
STREAMS LATE THIS WEEKEND. THIS WILL BE QUITE DIFFERENT FROM THE
RATHER STABLE PATTERN WE HAVE BEEN IN...WHICH FEATURED A BROAD
MID LEVEL TROUGH OVER THE WESTERN USA...AND A SUBTROPICAL RIDGE
ALONG THE EAST COAST. ULTIMATELY...THIS SHOULD MEAN OUR PRESENT
ACTIVE WEATHER PATTERN IS LIKELY TO CONTINUE. THE MOST NOTICEABLE
DIFFERENCE WILL BE THE RETURN TO MORE SEASONABLE TEMPERATURES...
WHICH IN TURN OPENS THE DOOR FOR SOME EPISODES OF WINTRY
PRECIPITATION.
24/00Z GUIDANCE SUITE REMAINS IN RELATIVELY GOOD AGREEMENT THROUGH
MONDAY...BEFORE DEVELOPING MORE SIGNIFICANT DIFFERENCES. WILL
FAVOR A CONSENSUS APPROACH TO SMOOTH OVER THE MINOR DIFFERENCES
THROUGH MONDAY...AND PROVIDE A MORE MIDDLE OF THE ROAD APPROACH
THEREAFTER...WHEN PREDICTABILITY IS NOT SO HIGH.
*/ DISCUSSION...
SATURDAY INTO SUNDAY...
AS NOTED BEFORE...EXPECTING A CLASSIC MATURE LOW PASSAGE JUST TO
OUR NORTH AND WEST. AT THE PRESENT TIME...STILL LOOKING LIKE AN
ALL- RAIN EVENT DURING THIS PORTION OF THE FORECAST. WHILE NOT
RAINING THE ENTIRE TIME...THE MOST LIKELY PERIOD FOR PRECIPITATION
LOOKS TO BE SATURDAY AFTERNOON INTO SUNDAY MORNING.
EXPECTING MORE SEASONABLE AIR TO PUSH INTO OUR REGION BEHIND A
COLD FRONT SUNDAY NIGHT.
NEXT WEEK...
THIS IS STILL LARGELY A LOW CONFIDENCE FORECAST FOR THE SPECIFICS.
HAVE MODERATE CONFIDENCE IN OVERALL TIMING FOR PRECIPITATION. JUST
NOT IN WHICH PRECIPITATION TYPES WE WILL SEE. WITH MORE SEASONABLE
TEMPERATURES EXPECTED...WE COULD FINALLY SEE SOME WINTRY
PRECIPITATION IN SOUTHERN NEW ENGLAND. REALISTICALLY...THIS COULD
INCLUDE POCKETS OF FREEZING RAIN OR SLEET. WITH SUCH LOW
CONFIDENCE IN TEMPERATURE PROFILES THOUGH...WILL LIMIT
PRECIPITATION TYPES TO RAIN...SNOW...OR A RAIN/SNOW MIX. THIS WILL
OBVIOUSLY NEED TO BE WATCHED OVER THE NEXT SEVERAL DAYS.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY/...
TODAY...HIGH CONFIDENCE. EXPECTING A GRADUAL IMPROVEMENT IN
CONDITIONS TO MVFR AS PATCHY FOG LIFTS LATER THIS MORNING. IFR
LIKELY LINGERS TOWARD THE SOUTH COAST...INCLUDING THE CAPE AND
ISLANDS. SCT -SHRA THIS AFTERNOON MAY BRIEFLY REDUCE CONDITIONS
TO MVFR. LLWS THIS MORNING FOR MOST AREAS...THEN BECOMING LIMITED
TO THE CAPE AND ISLANDS THIS AFTERNOON.
TONIGHT...HIGH CONFIDENCE. VFR FOR MUCH OF THE AREA. MVFR VSBYS
AND IFR CIGS LIKELY ALONG THE IMMEDIATE SOUTH COAST...CAPE...AND
ISLANDS IN LOW CLOUDS AND PATCHY FOG.
CHRISTMAS DAY...HIGH CONFIDENCE. QUICK IMPROVEMENT TO VFR
CONDITIONS ALL LOCATIONS.
KBOS TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
EXACT TIMING. LLWS LIKELY THROUGH 18Z.
KBDL TERMINAL...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN
EXACT TIMING. LLWS LIKELY THROUGH 15Z.
OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...
SATURDAY INTO SUNDAY...MODERATE CONFIDENCE.
CONDITIONS DETERIORATING TO A MIX OF MVFR-LIFR. WORST CONDITIONS
SATURDAY NIGHT INTO SUNDAY WITH LIKELIHOOD OF +RA...LOW CIGS AND
FOG. BREEZY SOUTH WINDS...STRONGEST SUNDAY WITH GUSTS ALONG THE
S/SE COAST OF AROUND 25 KTS.
MONDAY...MODERATE CONFIDENCE.
MAINLY VFR AS A HIGH PRESSURE MOVES ACROSS NORTHERN NEW ENGLAND.
NORTH WINDS INCREASING.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH FRIDAY/...HIGH CONFIDENCE.`
SMALL CRAFT ADVISORIES CONTINUE THROUGH FOR ALL WATERS EXCEPT
BOSTON HARBOR AND NARRAGANSETT BAY THROUGH TODAY. AS SEAS AND
WINDS DIMINISH TONIGHT INTO TOMORROW WITH BUILDING HIGH
PRESSURE...ADVISORIES WILL DROP OFF FOR THE INNER WATERS.
HOWEVER...THEY WILL CONTINUE FOR THE SOUTHERN OUTER WATERS THROUGH
CHRISTMAS DAY.
OUTLOOK /FRIDAY NIGHT THROUGH MONDAY/...
SATURDAY INTO SUNDAY...MODERATE CONFIDENCE.
WARM FRONT MOVES NORTH OF THE WATERS SATURDAY NIGHT INTO
SUNDAY...BRINGING A PERIOD OF MODERATE RAIN ALONG WITH LIKELY LOW
CLOUDS AND FOG. SHOULD BE SOME VISIBILITY RESTRICTIONS. INCREASING
S WINDS...WITH THE STRONGEST SUNDAY. ROUGH SEAS LIKELY DEVELOPING
ACROSS THE OUTER COASTAL WATERS SUNDAY.
MONDAY...MODERATE CONFIDENCE.
BRIEF LULL PRECIPITATION-WISE DURING THE DAY. MAINLY NORTH WINDS
WITH GUSTS UP TO 25 KTS. THINKING MOST PRECIPITATION OVER THE
WATERS WILL BE IN THE FORM OF RAIN MONDAY NIGHT...BUT CAN NOT RULE
OUT AN INITIAL WINTRY MIX.
&&
.CLIMATE...
RECORD HIGH MINIMUM TEMPERATURES FOR TODAY 12/24...
BOSTON 44/2003
PROVIDENCE 45/1941
HARTFORD 43/1931
WORCESTER 43/2003
RECORD HIGH TEMPERATURES FOR TODAY 12/24...
BOSTON 61/1996
PROVIDENCE65/2015 - NEW RECORD - PREVIOUSLY 64/2014
HARTFORD59/1996 AND 1990
WORCESTER57/1996 AND 1990
RECORD HIGH MINIMUM TEMPERATURES FOR FRIDAY 12/25...
BOSTON 44/2014
PROVIDENCE 46/1979
HARTFORD 43/2014
WORCESTER 47/1964
RECORD HIGH TEMPERATURES FOR FRIDAY 12/25...
BOSTON 65/1889
PROVIDENCE63/2014
HARTFORD64/1964
WORCESTER60/1964
RECORD HIGH TEMPERATURES FOR SUNDAY 12/27...
BOSTON 61/1949
PROVIDENCE59/1973
HARTFORD60/1949
WORCESTER 58/1895
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST FRIDAY FOR ANZ231>234.
SMALL CRAFT ADVISORY UNTIL 7 PM EST FRIDAY FOR ANZ235-237-
254>256.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ250.
SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR ANZ251.
&&
$$
SYNOPSIS...BELK/RLG
NEAR TERM...BELK/RLG
SHORT TERM...RLG
LONG TERM...BELK
AVIATION...BELK/RLG
MARINE...BELK/RLG
CLIMATE...STAFF
AREA FORECAST DISCUSSION...CORRECTED
NWS NEW YORK NY
708 AM EST THU DEC 24 2015
.SYNOPSIS...
LOW PRESSURE MOVING THROUGH CANADA WILL DRAG A COLD FRONT ACROSS
THE REGION TODAY. THE FRONT WILL SLOWLY SAG SOUTH OF THE REGION
LATE TONIGHT...AND TOWARDS THE MID ATLANTIC STATES ON CHRISTMAS
AS HIGH PRESSURE BUILDS IN FROM THE NORTH. UNSETTLED WEATHER WILL
RETURN FOR THE WEEKEND AND INTO NEXT WEEK AS A SERIES OF STORM
SYSTEMS MOVE ACROSS.
&&
.NEAR TERM /THROUGH TONIGHT/...
A BREEZY AND INCREDIBLY WARM DAY TODAY (ABOUT 30 DEGREES ABOVE
SEASONABLE).
PHASED SHORTWAVE PIVOTS FROM THE UPPER GREAT LAKES INTO QUEBEC
TODAY...WHILE DEEP TROUGHING RE-ESTABLISHES ACROSS THE WESTERN US
THROUGH TONIGHT. MEANWHILE...BERMUDA RIDGING REMAINS IN CONTROL TO
THE EAST...CONTINUING THE DEEP SW FLOW INTO THE REGION.
AT THE SURFACE...STRONG GREAT LAKES LOW PRESSURE CONTINUES TO TRACK
UP TOWARDS HUDSONS BAY TODAY...WITH ITS WEAKENING TRAILING COLD
FRONT APPROACHING THE REGION LATE TODAY INTO THIS EVENING. HIGHER
RES MODELS INDICATING POTENTIAL FOR A PRE-FRONTAL TROUGH DEVELOPING
ACROSS WESTERN PORTIONS OF THE TRI-STATE THIS AFTERNOON.
AREAS OF FOG WITH VSBY 1/2 TO 1 MILE EXPECTED TO CONTINUE THROUGH
THE MORNING ACROSS LI AND CT IN ADVECTION FOG. A GRADUAL
IMPROVEMENT IN VSBY EXPECTED THROUGH THE LATE MORNING...BUT
NEARSHORE LOCATIONS COULD HOLD WITH POOR VISIBILITIES INTO THE
AFTERNOON WITH MARINE LAYER. AWAY FROM MARINE INFLUENCE...SUCH AS
NYC/NJ METRO AND INTERIOR LOCATIONS...SHOULD SEE A MORE RAPID
IMPROVEMENT IN VSBY THIS MORNING.
HIGH-RES NCAR ENSEMBLE AND HRRR DOING A FAIRLY GOOD JOB OF
PICKING UP ON SHOWER ACTIVITY DEVELOPING OVER MID ATLANTIC ON
NOSE OF DEVELOPING 55-60 KT LLJ. THIS DEVELOPING ACTIVITY AND
REMNANTS OF PA CONVECTIVE LINE ARE EXPECTED TO TRANSLATE FROM SW
TO NE THROUGH THE REGION THIS MORNING INTO EARLY AFTERNOON AHEAD
OF A PRE- FRONTAL TROUGH. WITH WEAK ELEVATED INSTABILITY AND
FORCING...WILL INCLUDE A SLIGHT CHANCE OF THUNDER THIS MORNING.
THIS AFTERNOON...APPEARS LLJ FORCING AND WEAK SURFACE TROUGH
MOVES EAST. MARGINAL INSTABILITY (POTENTIALLY SURFACE BASED ACROSS
NE NJ/LOWER HUD) STILL EXISTS...BUT NOT MUCH FORCING OR
CONVERGENCE WITH THE APPROACHING COLD FRONT. SO SHOWER POTENTIAL
APPEARS TO BE LOW CHANCE TO SLIGHT...WITH LOW CONFIDENCE ON ANY
THUNDER BASED ON THE WEAK FORCING. BETTER CHANCE OF THUNDER LOOKS
TO BE SOUTH OF THE TRI- STATE. BASED ON WIND PROFILE...GUSTY WINDS
OF 40+ MPH COULD ACCOMPANY ANY HEAVY SHOWER OR TSTM ACTIVITY.
IN TERMS OF WINDS TODAY...950 HPA WINDS OF 35 TO 40 KT ARE
EXPECTED...BUT MIXING IS THE CHALLENGE IN FORECASTING WIND
SPEEDS. SUSTAINED SE WINDS OF 10 TO 20 MPH WITH PEAK WINDS GUSTS
OF 25 TO 30 MPH LIKELY CONTINUE INTO EARLY
AFTERNOON...PARTICULARLY CITY/COAST. IF WE DO SEE SOME BREAKS OF
SUN AND RESULTANT INCREASED MIXING...SUSTAINED WINDS OF 20 TO 25
MPH AND GUSTS 35 TO 40 MPH ARE POSSIBLE AWAY FROM MARINE
INFLUENCE. THIS IS A LOW PROB.
IN TERMS OF TEMPS TODAY...TEMPS ALREADY STARTING AT RECORD LEVELS
(LOWER TO UPPER 60S) AT 5 OF 6 FIRST ORDER CLIMATE SITES THIS
MORNING. LOW SUN ANGLE...ABUNDANT CLOUD COVER...AND MIXING LIMITED
TO 950 HPA...WILL LIMIT POTENTIAL HEATING. BUT RECORD TEMPS IN THE
UPPER 60S TO LOWER 70S ARE EXPECTED FOR MOST OF THE REGION. A LOW
POTENTIAL FOR MID TO UPPER 70S NYC/NJ METRO...IF BREAKS OF SUN
ARE REALIZED.
TONIGHT...MODELS HAVE TRENDED SLOWER WITH COLD FRONTAL PASSAGE.
WITH MODELS SIGNALING WEAK DAYTIME CONVECTION INDUCED VORTS
TRACKING IN THE SW FLOW ALOFT...WITH LINGER SHOWER THREAT ACROSS
NYC/NJ METRO AND LONG ISLAND INTO THE OVERNIGHT.
OTHERWISE...UNSEASONABLY MILD CONDITIONS EXPECTED TO CONTINUE WITH
LOWS GENERALLY IN THE 50S CITY/COAST AND 40S INTERIOR. LIGHT NW
FLOW EXPECTED IN THE WAKE OF THE FRONT...WITH SOME DRIER AIR
TRYING TO ADVECT IN. AMOUNT OF CLOUD COVER ALOFT WILL DETERMINE
DENSE FOG COVERAGE...BUT POTENTIAL EXISTS FOR AT LEAST PATCHY
DENSE FOG.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
MODELS COMING INTO BETTER AGREEMENT WITH CHRISTMAS INTO SATURDAY
PERIOD...WITH TROUGHING CONTINUING TO DEEPEN INTO THE SW US AND
BERMUDA HIGH SLOWLY DRIFTING SW TOWARDS FLORIDA. THIS WILL
CONTINUE TO PLACE THE REGION UNDER A DEEP SW PAC/SUB TROPICAL
FLOW.
AT THE SURFACE...APPEARS TO BE BETTER AGREEMENT WITH WEAK RIDGING
BUILDING INTO THE REGION ON CHRISTMAS DAY...PUSHING TODAYS COLD
FRONT TO THE MID ATLANTIC. THE SUBSIDENCE AND LOW-MID LEVEL
DRYING SHOULD PRESENT A DRY...AND ANOTHER RECORD BREAKING WARM
DAY. A PERIOD OF MOSTLY SUNNY SKIES LIKELY AFTER MORNING
STRATUS/FOG BURN OFF AND BEFORE HIGH CLOUD START TO STREAM IN IN
THE AFTERNOON.
MODELS CONVERGING ON AN INCREASING CHANCE FOR RAIN FRIDAY NIGHT INTO
SAT. AS THE WESTERN TROUGH APPROACHES THE CENTRAL US...DECENT
AGREEMENT IN A SERIES OF LOW PRESSURE WAVES BEGIN TO DEVELOP FROM
THE GULF COAST UP THE MISSISSIPPI RIVER VALLEY...LIFTING THE WARM
FRONT ACROSS THE MID-ATLANTIC UP TOWARDS THE REGION. POTENTIAL
FOR A FEW PERIODS OF LIGHT TO MODERATE RAIN AS SERIES OF WEAK
WAVES RIDE ALONG THE WARM FRONT INDUCED BY SOUTHERN STREAM
ENERGIES ROUNDING THE RIDGE.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MODELS DIFFER WITH THE POSITION AND TIMING OF A SERIES OF FRONTAL
PASSAGES AND LOW PRESSURE SYSTEMS ASSOCIATED WITH THEM...BUT
GENERALLY A MILD AND UNSETTLED PATTERN. MONDAY HAS THE BEST
CHANCE OF REMAINING DRY AS HIGH PRESSURE BUILDING IN FROM THE
NORTH WOULD APPEAR TO BE STRONG ENOUGH TO SUPPORT IT. TUESDAY HAS
THE BEST CHANCE OF SEEING PCPN...BUT WILL CAP POPS AT CHC DUE TO
THE UNCERTAINTY. FOR LATE MONDAY NIGHT INTO TUESDAY
MORNING...THERMAL PROFILES COULD SUPPORT A WINTRY MIX FOR THE
NORTHERN FRINGE ZONES.
TEMPERATURES THROUGH THE LONG TERM MAINLY WARMER THAN NORMAL.
&&
.AVIATION /11Z THURSDAY THROUGH MONDAY/...
A COLD FRONT WILL APPROACH FROM THE WEST THIS AFTERNOON. IFR AND
BELOW CONDITIONS CONTINUE INTO THIS MORNING. DENSE FOG WILL AFFECT
SOME TERMINALS...BUT IT IS UNCERTAIN WHERE VSBYS WILL DROP TO 1/4 OR
BELOW BESIDES KHPN. ANY IMPROVEMENT THROUGH THE DAY IS EXPECTED TO
BE MARGINAL AT MOST ESPECIALLY FARTHER WEST AWAY FROM THE COAST.
THERE WILL BE A CONTINUED CHANCE OF SHOWERS GOING INTO THE DAY.
LOW LEVEL JET WINDS AT 2KFT EXPECTED TO BE SW AT 40-45 KT THROUGH
THE MORNING AND INTO EARLY AFTERNOON. AT THE SURFACE...A 10-15 KT
S-SW FLOW WILL START TO LOWER THIS AFTERNOON AND FURTHERMORE
TONIGHT. ANOTHER ROUND OF FOG AND LOW STRATUS WILL BE POSSIBLE
LATE TONIGHT.
WITH A LARGE GRADIENT OF CATEGORIES WITHIN A SMALL
DISTANCE...THE FORECAST HAS LOW CONFIDENCE ESPECIALLY WITH
CATEGORY.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: IMPROVEMENT COULD OCCUR EARLIER THAN
FORECAST. MVFR COULD OCCUR A FEW HOURS EARLIER THAN INDICATED.
KLGA FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY VFR
THIS MORNING. CONDITIONS COULD DROP BACK TO MVFR/IFR AT TIMES.
KEWR FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY VFR
THIS MORNING. CONDITIONS COULD DROP BACK TO MVFR/IFR AT TIMES.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH
IMPLIES SLANT RANGE VISIBILITY 3-5SM OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: UNCERTAIN ON HOW LONG CONDITIONS STAY
MVFR. AMENDMENTS LIKELY TO REFINE TIMING OF CATEGORICAL CHANGES.
KHPN FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING OF
IMPROVEMENT FROM VLIFR...WHICH COULD BE OFF BY A FEW HOURS.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY TO REFINE TIMING
OF IMPROVEMENT FROM VLIFR...WHICH COULD BE OFF BY A FEW HOURS.
.OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY...
.FRIDAY...IFR POSSIBLE IN THE MORNING.
.SAT-SUN...MVFR OR LOWER POSSIBLE IN -RA.
.MON...SLIGHT CHANCE OF -SHRA WITH MVFR OR LOWER.
&&
.MARINE...
WITH PROLONGED SOUTHERLY FETCH...SEAS ON THE OCEAN WILL STAY
ELEVATED. SCA REMAINS IN EFFECT THERE AS WINDS TOO HAVE BEEN GUSTING
TO 25-30 KT. OCCASIONAL GUSTS TO 25 KT ON REMAINDER OF WATERS.
THE WINDS WILL LOWER TONIGHT AND FRIDAY WHILE OCEAN SEAS WILL
LIKELY STAY ELEVATED WITH CONTRIBUTING SWELL.
WITHOUT MUCH OFFSHORE FLOW IN THE FORECAST...THE HIGHER OCEAN SEAS
MAY VERY WELL LINGER INTO THIS WEEKEND. HOWEVER GOING INTO THE
WEEKEND...FORECAST OCEAN WAVE HEIGHTS ARE MORE MARGINAL FOR
SCA...RIGHT AROUND 5 FT FRIDAY NIGHT THROUGH SATURDAY NIGHT.
WITH ABUNDANT LOW-LEVEL MOISTURE OVER THE WATERS...WIDESPREAD
DENSE FOG WILL CONTINUE THROUGH THE DAY. THE DENSE FOG ADVISORY HAS
BEEN EXTENDED TO 6 PM FOR MOST WATERS.
WINDS WILL EVENTUALLY INCREASE...BUT GUSTS TO 25KT APPEAR TO
BE LIMITED TO MAINLY THE OCEAN SUNDAY NIGHT AND MONDAY. THERE IS A
CHANCE THAT 25KT GUSTS OCCUR ON THE EASTERN SOUND AS WELL.
&&
.HYDROLOGY...
BASIN AVG QPF FROM .75 TO 2 INCHES WAS NOTED ACROSS THE TRI-STATE
WITH THIS RAIN EVENT.
ADDITIONAL LIGHT TO MODERATE RAINFALL POSSIBLE THIS WEEKEND. A SIGNIFICANT
RAINFALL IS POSSIBLE EARLY NEXT WEEK.
&&
.TIDES/COASTAL FLOODING...
HIGH TIDES IN COMBINATION WITH RESIDUAL SURGE COULD CAUSE BRIEF
AND LOCALIZED MINOR COASTAL FLOODING ACROSS THE TYPICALLY
VULNERABLE LI SOUTH SHORE BAYS LOCALES DURING TIMES OF HIGH TIDE
THIS MORNING.
MINOR ATLANTIC OCEAN BEACH EROSION POSSIBLE...PARTICULARLY THIS
MORNING...WITH 5 TO 7 FT SOUTHERLY SWELLS AND TIDES RUNNING HIGH.
&&
.CLIMATE...
HIGH TEMPERATURE RECORDS FOR DECEMBER 24TH HAVE ALREADY BEEN SET AT
MOST OF THE CLIMATE SITES SO FAR. SEE BELOW FOR THE HIGHS SO FAR AND
THE FINAL HIGH TEMPERATURES WE ARE FORECASTING LATER TODAY.
LOCATION HIGH YEAR FORECAST
NEWARK 68 2015 75
BRIDGEPORT 61 2015 66
CENTRAL PARK 67 2015 74
LAGUARDIA 63 1990 73
KENNEDY 61 2015 69
ISLIP 62 2015 66
HERE ARE THE HIGH TEMPERATURE RECORDS AND FORECAST HIGHS
FOR DECEMBER 25...CHRISTMAS DAY...
LOCATION HIGH YEAR FORECAST
NEWARK 69 1964 67
BRIDGEPORT 59 1964 63
CENTRAL PARK 64* 1982 66
LAGUARDIA 63 2014 66
KENNEDY 58 1982 65
ISLIP 56 2014 64
*ALSO OCCURRED IN PREVIOUS YEARS
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...DENSE FOG ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ338.
DENSE FOG ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ330-335-
340-345-350-353-355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST FRIDAY FOR ANZ350-353-355.
&&
$$
SYNOPSIS...NV
NEAR TERM...NV
SHORT TERM...NV
LONG TERM...JC
AVIATION...JM
MARINE...JM
HYDROLOGY...NV
TIDES/COASTAL FLOODING...NV
CLIMATE...JM
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1045 AM EST THU DEC 24 2015
.UPDATE...
ISSUED AT 1045 AM EST THU DEC 24 2015
15Z SFC ANALYSIS SHOWS A WEAK AND FLEETING AREA OF HIGH PRESSURE
MOVING OVER THE LOWER OHIO VALLEY IN THE WAKE OF A LOW PRESSURE
WAKE DEPARTING TO THE EAST. THIS WAVE PULLED THE LAST OF THE
SHOWERS OUT OF THE AREA AROUND DAWN AND HAS ALSO TAKEN THE BULK OF
THE LOW AND MID LEVEL CLOUDS OUT AS WELL. TEMPERATURES THROUGH
EAST KENTUCKY STARTED OUT WARM AND HAVE BASICALLY HELD STEADY AS
THE INSOLATION IS COUNTERING THE LIMITED CAA IN THE WAKE OF THE
LOW. NORTHWEST PARTS OF THE AREA HAVE MANAGED TO SETTLE INTO THE
UPPER 50S WHILE THE REST OF THE AREA IS GENERALLY IN THE LOW 60S.
EXPECT A REBOUND TO THE NORTHWEST TEMPS BY MID AFTERNOON WHILE THE
THERMOMETERS OF THE REST OF EASTERN KENTUCKY CREEP UP TOWARD THE
MID AND UPPER 60S. SOME DRIER AIR IS INBOUND WITH THE HIGH
PRESSURE AS WELL AND READINGS CURRENTLY REFLECT THAT...VARYING
FROM THE UPPER 40S IN THE NORTHWEST TO THE UPPER 50S AND LOW 60S
IN THE SOUTHEAST TWO THIRDS OF THE CWA. WINDS HAVE TURNED TO THE
NORTHWEST FOR MUCH OF EASTERN KENTUCKY...BUT ARE STILL CALM OR
SOUTHWEST NEARER TO WEST VIRGINIA AND VIRGINIA. HAVE UPDATED THE
FORECAST TO REFLECT LESS SKY COVER AND NEAR ZERO POPS THROUGH THE
REST OF THE DAY ALONG WITH ADDING IN THE LATEST SHORTBLEND
GUIDANCE FOR THE T AND TD GRIDS. THESE HAVE BEEN FINALIZED WITH
THE CURRENT OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 757 AM EST THU DEC 24 2015
PRECIPITATION HAS EXITED THE AREA...AND THE LATEST HRRR HAS BEEN
SHOWING NO OTHER ACTIVITY FOR THE REST OF THE DAY. THIS SEEMS
REASONABLE GIVEN THE LACK OF FORCING. AS SUCH...HAVE REMOVED POPS
FOR THE REST OF THE DAY. ALSO FRESHENED UP THE HOURLY TEMPERATURES
AND DEW POINTS BASED ON THE LATEST TRENDS IN OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
A SURFACE COLD FRONT...STEMMING FROM DEEP LOW PRESSURE CENTERED
ACROSS SOUTH CENTRAL ONTARIO...IS ALIGNED FROM EASTERN INDIANA
DOWN ACROSS CENTRAL KENTUCKY. CONVECTION HAS RACED WELL OUT AHEAD
OF THE BOUNDARY...BEING SUSTAINED BY A STOUT LOW LEVEL JET. THE
WIDESPREAD ACTIVITY HAS ALL BUT CLEARED FAR SOUTHEASTERN
KENTUCKY...WITH JUST A FEW SHOWERS LINGERING BEHIND THE MAIN LINE.
CURRENT OVERNIGHT TEMPERATURES ARE STILL RUNNING WELL ABOVE THE
NORMAL DAYTIME HIGHS FOR THIS TIME OF YEAR...WITH READINGS
RANGING FROM THE UPPER 50S TO LOWER 60S. ALOFT...DEEP TROUGHING
RULES ACROSS THE WESTERN TWO THIRDS OF THE NATION...WITH A MORE
SUMMER-LIKE HIGH POSITIONED ACROSS THE WESTERN ATLANTIC.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM.
CONVECTION WILL CONTINUE TO WANE ACROSS OUR AREA...AS THE LOW
LEVEL JET DIMINISHES AND THE SURFACE COLD FRONT GETS SHEARED
OUT. PASSING HIGH PRESSURE TO OUR NORTH WILL KEEP THINGS DRY
THROUGH MOST OF TONIGHT. MEANWHILE...THE NEXT BIG CHUNK OF ENERGY
WILL BE DIGGING IN FROM THE EASTERN PACIFIC. THIS WILL ALLOW AN
INVERTED SURFACE TROUGH TO DEVELOP AND NOSE IN FROM THE SOUTHWEST
BY EARLY CHRISTMAS DAY...WITH ANOTHER ROUND OF WIDESPREAD SHOWERS
AND A FEW THUNDERSTORMS POSSIBLE.
THE MODELS HAVE BEEN VARYING WITH THE AMOUNT AND POSITION OF THE
HEAVIER QPF...WITH THE ECMWF AND NAM BEEFIER...WHILE THE GFS HAS
BEEN LEANER. GIVEN THE FACT THAT THERE IS WEAK MID AND UPPER LEVEL
FORCING...AM INCLINED TO PUT MORE CONFIDENCE IN THE LEANER TOTALS
FOR NOW. STILL...PWATS ARE EXTREMELY HIGH AND ANY TRAINING
THUNDERSTORM ACTIVITY COULD CERTAINLY BRING TOTALS MORE TOWARDS
THE HIGHER END...UPWARDS OF 2 INCHES IN A 6 TO 12 HOUR PERIOD.
CONSEQUENTLY...WILL CONTINUE TO MENTION GENERALIZED FLOODING
CONCERNS IN THE HWO.
FOR TEMPERATURES...A MORE DIURNALLY LIMITED REGIME WAS
FAVORED...GIVEN THE CLOUDS AND QUICK RETURN OF PRECIPITATION BY
CHRISTMAS DAY. HIGHS TODAY WILL RANGE FROM THE MID TO UPPER
60S...WITH READINGS MORE IN THE LOW TO MID 60S FOR THE HOLIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
MODELS ARE IN GENERALLY GOOD AGREEMENT ON THE MILD AND WET PATTERN
PERSISTING THROUGH THE WEEKEND INTO NEXT WEEK. IT DOES LOOK LIKE THE
WARM FRONT SHOULD LIFT NORTH FRIDAY NIGHT INTO EARLY SATURDAY WITH
RAIN CHANCES LIFTING NORTH OF THE AREA. THUS...MUCH OF SATURDAY
COULD END UP ON THE DRIER SIDE (WHICH WOULD NOT BE A BAD THING). IF
THE DRIER FORECAST PANS OUT...TEMPERATURES COULD SOAR INTO THE LOW
TO MID 70S SOUTH OF THE WARM FRONT...SETTING UP ANOTHER RECORD
BREAKING DAY. IF CLOUDS HOLD ON OR PRECIPITATION HOLDS ON
LONGER...WE MIGHT HAVE TO SETTLE FOR READINGS CLOSER TO 70...BUT
STILL MILD. PRECIPITATION STAYS NORTH INTO SATURDAY NIGHT...BUT THE
FRONT WILL BE DRIVEN BACK TO THE SOUTH ON SUNDAY WITH RAIN CHANCES
RAMPING BACK UP. THE FRONT WILL THEN STALL IN OUR VICINITY KEEPING
THE WEATHER UNSETTLED INTO MONDAY. FINALLY A COLD FRONT SHOULD SWEEP
ACROSS THE AREA MONDAY NIGHT/TUESDAY...BRINGING AN END TO THE
EXTENDED PERIOD OF WET AND MILD WEATHER. TEMPERATURES WILL TAKE A
HIT BY WEDNESDAY WITH HIGHS BACK INTO THE LOWER 50S (BUT STILL ABOVE
NORMAL!). A SECONDARY COLD FRONT COULD BRING A BETTER SURGE OF
COLDER AIR AS WE HEAD INTO NEW YEARS EVE...BRINGING A RETURN OF
MORE SEASONABLE WINTER WEATHER TO EASTERN KENTUCKY.
FORTUNATELY...DESPITE IT TURNING COLDER NEXT WEEK...STILL NO SIGNS
OF ANY SNOWFALL FOR OUR NECK OF THE WOODS.
WITH ALL THE RAIN EXPECTED ON FRIDAY/FRIDAY NIGHT...COUPLED WITH THE
RAIN SUNDAY INTO TUESDAY...WE WILL CONTINUE TO HAVE TO MONITOR
CONDITIONS FOR POSSIBLE FLOODING...ESPECIALLY ON THE RIVERS AND
CREEKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 757 AM EST THU DEC 24 2015
MVFR CEILINGS SHOULD GRADUALLY RAISE UP TO VFR THROUGH THIS
MORNING AS A WEAK AREA OF HIGH PRESSURE BUILDS IN ACROSS THE OHIO
VALLEY. CEILINGS WILL THEN LOWER DOWN TO MVFR LATER TONIGHT AND
THEN IFR THROUGH THE END OF THE PERIOD. RAIN SHOWERS WILL BE
MOVING BACK IN BY CHRISTMAS DAY. WINDS WILL AVERAGE AROUND 5 KTS
OR LESS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
757 AM EST THU DEC 24 2015
.UPDATE...
ISSUED AT 757 AM EST THU DEC 24 2015
PRECIPITATION HAS EXITED THE AREA...AND THE LATEST HRRR HAS BEEN
SHOWING NO OTHER ACTIVITY FOR THE REST OF THE DAY. THIS SEEMS
REASONABLE GIVEN THE LACK OF FORCING. AS SUCH...HAVE REMOVED POPS
FOR THE REST OF THE DAY. ALSO FRESHENED UP THE HOURLY TEMPERATURES
AND DEW POINTS BASED ON THE LATEST TRENDS IN OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
A SURFACE COLD FRONT...STEMMING FROM DEEP LOW PRESSURE CENTERED
ACROSS SOUTH CENTRAL ONTARIO...IS ALIGNED FROM EASTERN INDIANA
DOWN ACROSS CENTRAL KENTUCKY. CONVECTION HAS RACED WELL OUT AHEAD
OF THE BOUNDARY...BEING SUSTAINED BY A STOUT LOW LEVEL JET. THE
WIDESPREAD ACTIVITY HAS ALL BUT CLEARED FAR SOUTHEASTERN
KENTUCKY...WITH JUST A FEW SHOWERS LINGERING BEHIND THE MAIN LINE.
CURRENT OVERNIGHT TEMPERATURES ARE STILL RUNNING WELL ABOVE THE
NORMAL DAYTIME HIGHS FOR THIS TIME OF YEAR...WITH READINGS
RANGING FROM THE UPPER 50S TO LOWER 60S. ALOFT...DEEP TROUGHING
RULES ACROSS THE WESTERN TWO THIRDS OF THE NATION...WITH A MORE
SUMMER-LIKE HIGH POSITIONED ACROSS THE WESTERN ATLANTIC.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM.
CONVECTION WILL CONTINUE TO WANE ACROSS OUR AREA...AS THE LOW
LEVEL JET DIMINISHES AND THE SURFACE COLD FRONT GETS SHEARED
OUT. PASSING HIGH PRESSURE TO OUR NORTH WILL KEEP THINGS DRY
THROUGH MOST OF TONIGHT. MEANWHILE...THE NEXT BIG CHUNK OF ENERGY
WILL BE DIGGING IN FROM THE EASTERN PACIFIC. THIS WILL ALLOW AN
INVERTED SURFACE TROUGH TO DEVELOP AND NOSE IN FROM THE SOUTHWEST
BY EARLY CHRISTMAS DAY...WITH ANOTHER ROUND OF WIDESPREAD SHOWERS
AND A FEW THUNDERSTORMS POSSIBLE.
THE MODELS HAVE BEEN VARYING WITH THE AMOUNT AND POSITION OF THE
HEAVIER QPF...WITH THE ECMWF AND NAM BEEFIER...WHILE THE GFS HAS
BEEN LEANER. GIVEN THE FACT THAT THERE IS WEAK MID AND UPPER LEVEL
FORCING...AM INCLINED TO PUT MORE CONFIDENCE IN THE LEANER TOTALS
FOR NOW. STILL...PWATS ARE EXTREMELY HIGH AND ANY TRAINING
THUNDERSTORM ACTIVITY COULD CERTAINLY BRING TOTALS MORE TOWARDS
THE HIGHER END...UPWARDS OF 2 INCHES IN A 6 TO 12 HOUR PERIOD.
CONSEQUENTLY...WILL CONTINUE TO MENTION GENERALIZED FLOODING
CONCERNS IN THE HWO.
FOR TEMPERATURES...A MORE DIURNALLY LIMITED REGIME WAS
FAVORED...GIVEN THE CLOUDS AND QUICK RETURN OF PRECIPITATION BY
CHRISTMAS DAY. HIGHS TODAY WILL RANGE FROM THE MID TO UPPER
60S...WITH READINGS MORE IN THE LOW TO MID 60S FOR THE HOLIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
MODELS ARE IN GENERALLY GOOD AGREEMENT ON THE MILD AND WET PATTERN
PERSISTING THROUGH THE WEEKEND INTO NEXT WEEK. IT DOES LOOK LIKE THE
WARM FRONT SHOULD LIFT NORTH FRIDAY NIGHT INTO EARLY SATURDAY WITH
RAIN CHANCES LIFTING NORTH OF THE AREA. THUS...MUCH OF SATURDAY
COULD END UP ON THE DRIER SIDE (WHICH WOULD NOT BE A BAD THING). IF
THE DRIER FORECAST PANS OUT...TEMPERATURES COULD SOAR INTO THE LOW
TO MID 70S SOUTH OF THE WARM FRONT...SETTING UP ANOTHER RECORD
BREAKING DAY. IF CLOUDS HOLD ON OR PRECIPITATION HOLDS ON
LONGER...WE MIGHT HAVE TO SETTLE FOR READINGS CLOSER TO 70...BUT
STILL MILD. PRECIPITATION STAYS NORTH INTO SATURDAY NIGHT...BUT THE
FRONT WILL BE DRIVEN BACK TO THE SOUTH ON SUNDAY WITH RAIN CHANCES
RAMPING BACK UP. THE FRONT WILL THEN STALL IN OUR VICINITY KEEPING
THE WEATHER UNSETTLED INTO MONDAY. FINALLY A COLD FRONT SHOULD SWEEP
ACROSS THE AREA MONDAY NIGHT/TUESDAY...BRINGING AN END TO THE
EXTENDED PERIOD OF WET AND MILD WEATHER. TEMPERATURES WILL TAKE A
HIT BY WEDNESDAY WITH HIGHS BACK INTO THE LOWER 50S (BUT STILL ABOVE
NORMAL!). A SECONDARY COLD FRONT COULD BRING A BETTER SURGE OF
COLDER AIR AS WE HEAD INTO NEW YEARS EVE...BRINGING A RETURN OF
MORE SEASONABLE WINTER WEATHER TO EASTERN KENTUCKY.
FORTUNATELY...DESPITE IT TURNING COLDER NEXT WEEK...STILL NO SIGNS
OF ANY SNOWFALL FOR OUR NECK OF THE WOODS.
WITH ALL THE RAIN EXPECTED ON FRIDAY/FRIDAY NIGHT...COUPLED WITH THE
RAIN SUNDAY INTO TUESDAY...WE WILL CONTINUE TO HAVE TO MONITOR
CONDITIONS FOR POSSIBLE FLOODING...ESPECIALLY ON THE RIVERS AND
CREEKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 757 AM EST THU DEC 24 2015
MVFR CEILINGS SHOULD GRADUALLY RAISE UP TO VFR THROUGH THIS
MORNING AS A WEAK AREA OF HIGH PRESSURE BUILDS IN ACROSS THE OHIO
VALLEY. CEILINGS WILL THEN LOWER DOWN TO MVFR LATER TONIGHT AND
THEN IFR THROUGH THE END OF THE PERIOD. RAIN SHOWERS WILL BE
MOVING BACK IN BY CHRISTMAS DAY. WINDS WILL AVERAGE AROUND 5 KTS
OR LESS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
923 AM EST THU DEC 24 2015
.SYNOPSIS...
A WARM FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON WITH
STRONG WARM AIR ADVECTION. THIS WILL SET THE STAGE FOR SEVERAL
RECORD HIGH TEMPERATURES TO BE BROKEN...ESPECIALLY ACROSS SOUTHERN
NEW HAMPSHIRE AND EXTREME SOUTHWEST MAINE. A WEAK COLD FRONT MOVES
ACROSS THE AREA TONIGHT WITH CLEARING CONDITIONS AND COOLER
TEMPERATURES. TEMPERATURES WILL STILL REMAIN WELL ABOVE NORMAL FOR
TONIGHT AND CHRISTMAS DAY. OUR NEXT STORM SYSTEM LOOKS TO ARRIVE
LATE SATURDAY INTO SUNDAY AND SHOULD BE MOSTLY IN THE FORM OF RAIN
ONCE AGAIN. HOWEVER...COLDER AIR WILL PUSH INTO THE REGION THE
BEGINNING OF NEXT WEEK AND COULD REMAIN IN PLACE LONG ENOUGH FOR
SEVERAL LOCATIONS TO SEE THEIR FIRST MEASURABLE SNOWFALL OF THE
SEASON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
9 AM UPDATE...
DIURNAL CURVE REMAINS A CHALLENGE WITH WARM FRONT SNAKING THROUGH
THE REGION AND ALONG THE COAST. PLENTY OF MOISTURE IS POOLING IN
THE WARM SECTOR WITH TEMPERATURES IN OUR AREA IN THE LOW TO MID
40S. FARTHER SOUTH FROM ALBANY TO CAPE COD READINGS ARE IN THE LOW
60S. AS THE WARM FRONT LIFTS NORTH AND EAST WE WILL SEE THAT
WARMTH SPREAD NORTH AND EAST...HOWEVER IT MAY TAKE MOST OF THE
DAY FOR PORTIONS OF THE AREA. IN FACT IT MAY BE AFTER SUNSET THAT
SOME LOCATIONS REACH THEIR HIGHS...INCLUDING PORTLAND.
MANCHESTER AND NASHUA SHOULD REACH THEM MUCH SOONER.
A STRONG AND SHALLOW INVERSION IS NOTED ON THIS MORNING`S
SOUNDING AND IS RESPONSIBLE FOR KEEPING THE WARMER TEMPERATURES
JUST ALOFT. FOR INSTANCE MT WASHINGTON ALREADY BROKE THEIR
TEMPERATURE RECORD FOR THE DAY.
WENT CLOSE TO THE 11Z HRRR FOR THE DIURNAL CURVE WHICH HAS A
BETTER HANDLE ON THE TEMPERATURES THAN THE LATER RUNS AND THE
LOCAL WRF. DRIZZLE/FOG CONTINUES FOR A FEW MORE HOURS UNTIL THE
INVERSION CAN BE BROKEN/ERODED. THERE IS A STRONG LLJ (45 KT)
JUST OFF THE DECK AT AROUND FL025 KFT.
SOME FUN CHRISTMAS EVE WEATHER TRIVIA...THIS MORNING`S KGYX
SOUNDING HAD +13 DEGREES C AT 850MB TEMPERATURE...WHICH IS OUR
SECOND ALL TIME HIGHEST 850MB TEMPERATURE FOR DECEMBER. GOING UP
TO 700MB WE ARE +9 C WHICH IS THE HIGHEST EVER RECORDED FOR
NOVEMBER OR DECEMBER. FOR INSTANCE...KEY WEST`S SOUNDING THIS
MORNING WAS ONLY ONE DEGREE HIGHER (+10) AT 700MB THAN WE ARE!
PREVIOUS DISCUSSION...
WITH THE RAIN ENDING BY MORNING AS THE WARM FRONT ALOFT PASSES TO
OUR N...THE NEXT PROBLEM WILL BE DEALING WITH THE SHARP INVERSIONS
OVER THE AREA THAT BUFKIT SHOWS REMAINING IN PLACE AT ALL
LOCATIONS INTO THE EARLY AFTERNOON. THE SURFACE ANALYSIS ALREADY
SHOWS NICE LOW LEVEL DAMMING OCCURRING WITH NOSING OF HIGH
PRESSURE EXTENDING SOUTHWEST ACROSS ME AND NH. MODELS ARE ALL IN
AGREEMENT THE LOW LEVEL SOUTHWEST JET WILL BE RIDING OVER THIS
SHALLOW INVERSION INTO THE AFTERNOON. WITH THE LACK OF VENTILATION
OF ALL THE RESIDUAL MOISTURE COMBINING WITH STRONG WAA ABOVE THE
SURFACE..WILL EXPECT SUPERSATURATION OF THE AIR MASS TO REMAIN AND
FOG AND DRIZZLE TO REFORM IN THE MORNING...THE QUESTION WILL BE
HOW LOW VISIBILITIES WILL GO. THE DAY SHIFT WILL HAVE TO WATCH FOR
A POSSIBLE NEED OF A DENSE FOG ADVISORY IN SOME AREAS FOR A WHILE
INTO EARLY AFTERNOON. STILL CONFIDENT TEMPERATURES ARE EXPECTED TO
REACH RECORD HIGHS OVER SOUTHERN NH AND SOUTHWEST ME BUT WILL NOT
BE REALIZED UNTIL MID- LATE AFTERNOON AS THE INVERSIONS BREAK AND
A SUDDEN JUMP IN TEMPS WILL BE NOTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
A WEAK COLD FRONT WITH NOT MUCH COLD AIR IN ITS WAKE MOVES
THROUGH THE REGION TONIGHT ALLOWING CLEARING SKIES TO OCCUR AND
TEMPS TO COOL. EVEN STILL TEMPS WILL REMAIN WELL ABOVE NORMAL
TONIGHT AND CHRISTMAS DAY. USED A BLEND OF MODELS FOR MIN/MAX TEMP
FORECAST TONIGHT AND FRI.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRES SLIDES EWD THRU THE REGION FRI NIGHT. LOW TEMPS WILL
DEPEND ON THE AMOUNT OF CLOUD COVER THAT CAN MAKE IT INTO SRN
ZONES. EXPECT THAT MOST OF SAT WILL BE DRY...UNTIL THE EVE. S/WV
TROF MOVING THRU THE GREAT LAKES WILL INDUCE A WEAK LOW TO FORM
ALONG THE STALLED FRONTAL BOUNDARY TO OUR S. THIS WAVE WILL SPREAD
PRECIP INTO THE AREA FROM THE W SAT NIGHT. THERE IS NOT A LOT OF
COLD AIR AROUND FOR THIS SYSTEM...BUT DRY AIR ALOFT MAY ALLOW FOR
ENOUGH WET BULB COOLING TO BRING A MIX OR SNWFL INTO NRN ZONES.
WILL USE A TOP DOWN APPROACH TO PRECIP TYPE IN THOSE AREAS...TO
INTRODUCE A LITTLE WINTRY MIX. THIS IS STILL NEARLY 4 DAYS
OUT...SO DETAILS CAN CHANGE...BUT A LIGHT SNWFL IS POSSIBLE FOR
THE FAR N NEAR JACKMAN...WHILE THRU THE MTNS A LIGHT FREEZING RA
IS POSSIBLE.
BEHIND THIS SYSTEM...A SECONDARY S/WV WILL DRIVE A STRONG COLD
FRONT THRU THE REGION. FOR WHAT SEEMS LIKE THE FIRST TIME IN A
LONG WHILE MODEL GUIDANCE IS INDICATING A SEASONABLY COLD AIR
MASS. THAT/S RIGHT...BELOW NORMAL TEMPS ALOFT. SFC HIGH PRES THAT
BUILDS IN WITH THESE TEMPS IS ALSO FORECAST TO BE QUITE STRONG ON
BOTH GEFS AND ECMWF EPS. MODEL TIMING IS IN EXCELLENT AGREEMENT
FOR THIS RANGE...ARRIVING AROUND 18Z TUE...SO I HAVE NO PROBLEM
GOING WITH LIKELY POP. WITHOUT GETTING INTO TOO MUCH DETAIL FOR
DAY 6...CAREFUL EXAMINATION OF TEMP TRENDS ALOFT SHOW A PRETTY
CLASSIC SIGNAL FOR SNWFL TO MIX FOR A LARGE PART OF THE REGION.
HIGH HEIGHTS IN THE E IS THE TENDENCY STILL IN THE MID
LEVELS...AND THAT WILL WANT TO SEND ANY SYSTEM TO OUR W. THE
RESULTING WAA OVERHEAD WILL BRING IN WARMTH FROM THE SW. ALL MODEL
GUIDANCE SHOWS THIS EVOLUTION...WITH THE GFS AND ECMWF IN CLOSER
AGREEMENT THAN THE COLDER CMC. AGAIN...THIS SYSTEM IS TOO FAR OUT
TO START HAMMERING OUT EXACT SNWFL AMOUNTS...BUT THE CHANCES FOR A
MEASURABLE SNWFL ARE GROWING AND BECOMING MORE LIKELY. ANOTHER 24
HOURS AND THIS SYSTEM WILL BE CLOSER TO THE RANGE WHERE MEDIUM
RANGE GUIDANCE HISTORICALLY STARTS TO PERFORM WELL.
ONE THING THAT IS HIGHER CONFIDENCE IS THAT WITH STRONG HIGH PRES
AND PRECIP MOVING IN...COLD AIR DAMMING WILL KEEP TEMPS ON THE
COOL SIDE. MULTI-MODEL CONSENSUS IS ALREADY KEYING ON THIS AND
DROPPED THE PREVIOUS FORECAST BY SEVERAL DEGREES WHEN BLENDED IN.
IF SECONDARY LOW PRES DEVELOPS AS SUGGESTS BY OPERATIONAL AND
ENSEMBLE GUIDANCE...THESE COOLER SFC TEMPS COULD CONTINUE INTO
WED WITH THE COASTAL FRONT TUCKING BACK IN BEHIND IT.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SHORT TERM...IFR CONDITIONS IN LOW STRATUS AND AREAS OF FOG AND
DRIZZLE WILL CONTINUE THROUGH THE MORNING AND INTO THE AFTERNOON
AS SHARP SURFACE INVERSIONS REMAIN IN PLACE. LLWS WILL ALSO BE A
CONCERN DUE TO A RATHER STRONG LOW LEVEL JET ABOVE THE INVERSION
THROUGH MUCH OF THE DAY. BY MID TO LATE AFTERNOON ENOUGH MIXING
OCCURS TO SCOUR OUT THE INVERSIONS AND CONDITIONS TO IMPROVE TO
VFR AS WINDS ALSO SHIFT TO THE WEST. TONIGHT AND FRIDAY CONDITIONS
WILL BE VFR.
LONG TERM...VFR TO BEGIN THE PERIOD AS HIGH PRES IS IN CONTROL OF
THE REGION. CLOUDS INCREASE FROM THE W LATE SAT...WITH AREAS OF
MVFR AND LOCAL IFR DEVELOPING OVERNIGHT. EXPECTING MAINLY -RA FOR
ALL TERMINALS...THOUGH A LITTLE MIX MAY DEVELOP NEAR HIE
OVERNIGHT SAT. VFR RETURNS SUN EVE AS STRONG HIGH PRES MOVES INTO
THE AREA THRU MON.
&&
.MARINE...
SHORT TERM...A SCA WILL REMAIN IN PLACE AND WILL BE EXTENDED TO
FRIDAY MORNING OVER THE OUTER WATERS DUE TO FIRST WINDS AND SEAS
AND THEN JUST HAZ SEAS AS WINDS SHIFT TO THE WEST AND BECOME
LIGHT. THE SCA OVER PENOBSCOT BAY WILL BE DROPPED AND THE SCA OVER
CASCO BAY WILL BE FOR HAZ SEAS UNTIL 1 PM.
LONG TERM...WINDS AND SEAS LOOK TO REMAIN BELOW SCA THRESHOLDS
UNTIL EARLY NEXT WEEK WHEN STRONG HIGH PRES MOVES TOWARDS THE
WATERS. THE ACCOMPANYING NWLY CAA WILL MOST LIKELY BRING WINDS AND
SEAS TO SCA CONDITIONS. WEAK LOW PRES DEVELOPING IN THE GULF OF ME
TUE MAY EXTEND SCA CONDITIONS INTO MIDWEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 1 PM EST THIS
AFTERNOON FOR ANZ153.
SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR ANZ150-152-154.
&&
$$
NEAR TERM...HANES
SHORT TERM...MARINE
LONG TERM...LEGRO
AREA FORECAST DISCUSSION
NWS CARIBOU ME
555 AM EST THU DEC 24 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK TO OUR NORTHWEST TODAY PULLING A WARM
FRONT THROUGH THE REGION. A COLD FRONT WILL CROSS THE AREA LATE
TODAY THEN HIGH PRESSURE WILL BUILD IN FROM THE WEST CHRISTMAS
DAY INTO SATURDAY. LOW PRESSURE FROM THE MIDWEST WILL APPROACH
ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
545 AM UPDATE...THE LATEST HI-RES MODELS, INCLUDING THE RUC AND
HRRR, AS WELL AS THE NAM AND GFS, HAVE ALL BACKED OFF A BIT ON
TODAY`S WARMING. NORTHEASTERN MAINE IN PARTICULARLY IS LOOKING A
LITTLE COOLER THAN THE PREVIOUS FORECAST; NOTE THE RUC BARELY
BRINGS CAR AND PQI UP TO 40 DEGREES BY AFTERNOON. THIS IS LIKELY
TOO PESSIMISTIC, THOUGH THE WARMEST AIR WILL REMAIN TO OUR SOUTH.
HAVE LOWERED HIGH TEMPERATURES TODAY BY JUST A COUPLE OF DEGREES,
ESPECIALLY IN AROOSTOOK COUNTY AND PORTIONS OF THE CENTRAL
HIGHLANDS. THE CLIMATE SECTION HAS BEEN UPDATED WITH THE LATEST
FORECAST. ALSO LOWERED POPS A BIT THROUGH THIS AFTERNOON AS
SHOWERS DON`T LOOK TO BE AS WIDESPREAD AS PREVIOUSLY ANTICIPATED.
PREVIOUS DISCUSSION...A WARM FRONT CURRENTLY DRAPED ACROSS
EASTERN NEW YORK AND WESTERN NEW ENGLAND WILL CONTINUE TO LIFT
NORTH AND EAST THIS MORNING. WIDESPREAD RAIN WILL ALSO CONTINUE
THROUGH THE MORNING HOURS, BUT IT SHOULD TAPER DOWN TO SCATTERED
SHOWERS BY AFTERNOON ONCE THE FRONT PASSES THROUGH THE STATE. THE
COLD FRONT WILL QUICKLY FOLLOW, CROSSING FROM WEST TO EAST LATE
THIS AFTERNOON. NOTE THAT MUCH OF THE GUIDANCE INDICATES THAT
THERE WILL BE SHOWER ACTIVITY WITH THE FRONTAL PASSAGE, BUT EXPECT
PRECIPITATION TO END FAIRLY RAPIDLY THEREAFTER. TEMPERATURES,
ALREADY QUITE MILD FOR LATE DECEMBER, WILL CONTINUE TO RISE
THROUGH THE DAY. EXPECT UPPER 40S ACROSS THE NORTH AND LOWER TO
MID 50S IN THE BANGOR REGION DOWN TO THE COAST. SEE THE CLIMATE
SECTION BELOW FOR ADDITIONAL INFORMATION. DRIER AND COOLER AIR
WILL SLOWLY WORK INTO THE FORECAST AREA OVERNIGHT BEHIND THE
AFOREMENTIONED COLD FRONT. EVEN STILL, TONIGHT`S LOWS WILL BE WELL
ABOVE NORMAL.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE SHORT TERM CONTS TO LOOK FAIR...BREEZY AND PROGRESSIVELY
COLDER AS SFC HI PRES APCHS FROM THE W AND CROSSES THE REGION...
ALBEIT TEMPS WILL STILL BE ABV AVG FOR THIS TM OF SEASON...EVEN
ON SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
THE ONLY SIG CHG FOR THE LATE SAT NGT INTO SUN PRECIP EVENT IS
THAT OPNL MODELS HAVE TRENDED A LITTLE FURTHER S THAN YSTDY
ATTM...MEANING THAT MORE OF THE...NAMELY THE N AND PTNS OF E CNTRL
ME WILL HOLD ALL OR MSLY ALL SN WITH THIS EVENT. INTERIOR DOWNEAST
AND LOWER PENOBSCOT VLY LCTNS WILL LIKELY HAVE A MIX OF SN...PL
AND RN WITH THIS EVENT WHILE COASTAL AREAS RECEIVE MSLY RN AFT A A
RELATIVELY BRIEF START OF MIXED PRECIP. TOTAL STORM TOTAL QPF
STILL SUGGESTS THAT THIS EVENT WILL LIKELY BE AN ADV LVL EVENT...
ALTHOUGH LOW END WRNG CRITERIA SNFL COULD NOT BE RULED FOR SOME
LCTNS IF THE EVENTS CONTS A FEW HRS INTO SUN EVE BEFORE TAPERING
TO SN SHWRS. WE CONTD TO RAISE MAX POPS INTO THE CATEGORICAL RANGE
FOR THIS EVENT GIVEN RELATIVE MODEL CONSISTENCY OF SHOWING SIG
QPF.
FOLLOWING THE LOW AS IT MOVES E ACROSS NOVA SCOTIA...AN ARCTIC
FRONT AND UPPER LVL TROF FROM HUDSON BAY WILL BRING CLDY SKIES AND
SN SHWRS SPCLY TO THE N HLF OF THE FA LATE SUN NGT INTO ERLY MON
MORN...WITH SKIES BECOMING PTLY CLDY N AND MSLY SUNNY S BY MON
AFTN. AFT NEAR AVG OVRNGT LOWS...HI TEMPS MON LOOK TO BE A LITTLE
BLO AVG WITH A BRISK NW WIND. WINDS WILL DIMINISH MON EVE AND AND
BECOME LGT AND VRBL LATE MON NGT AS SKIES REMAIN MSLY CLR WITH THE
SFC HI PRES CROSSING THE REGION. THIS WILL LIKELY RESULT IN THE
COLDEST NGT OF THE WINTER SO FAR...WITH MANY LCTNS ACROSS THE
N...SPCLY THOSE IN BROAD RVR VLYS FALLING INTO THE SINGLE DIGITS
BELOW ZERO.
ANOTHER S/WV AND SFC LOW APCHG FROM THE MIDWEST WILL BRING
INCREASING CLDNSS TO THE REGION ON TUE WITH SN SLOWLY SPREADING SW
TO NE ACROSS THE REGION FROM TUE AFTN INTO TUE NGT. WITH THE TRACK
OF THE SFC LOW SHOWN TO BE FURTHER S THAN THE MODELS DID YSTDY...
THE CONSENSUS OF MOST MODELS ATTM IS THAT THE BEST POTENTIAL OF
QPF WITH THIS EVENT WILL BE OVR THE S HLF OF THE FA...WHERE WE
WEIGHT HIGHEST POPS IN THE LIKELY CATEGORY WITH HI CHC POPS ACROSS
THE N. FOLLOWING THIS SYSTEM FOR WED INTO WED NGT...BOTH THE 00Z
DTMNSTC GFS AND ECMWF SHOW SOME FOLLOW-UP S/WV ENERGY TRACKING OVR
THE FA FROM THE SW...SO WE MENTIONED LOW CHC SN SHWR POPS BOTH
PDS. TEMPS SHOULD SLOWLY MODERATE SOMEWHAT TUE THRU WED.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NEAR TERM: WIDESPREAD IFR/LIFR CEILINGS WILL PREVAIL THROUGH 18Z
THIS AFTERNOON, ALONG WITH REDUCED VISIBILITY DUE TO RAIN AND FOG.
CONDITIONS WILL IMPROVE LATER THIS AFTERNOON FROM WEST TO EAST AS
A COLD FRONT CROSSES THE REGION. EXPECT ALL SITES TO BE VFR BY 04Z
FRIDAY.
SHORT TERM: VFR XPCTD FRI INTO SAT EVE...THEN CLGS AND VSBYS
LOWERING TO IFR ALL SITES OVRNGT SAT INTO SUN WITH SN FOR NRN
TAF SITES AND MIXED PRECIP FOR DOWNEAST SITES. CONDITIONS IMPROVE
TO MVFR FOR NRN TAF SITES SUN NGT WITH SCT SN SHWRS AND VFR
DOWNEAST. VFR WILL CONT SUN FOR DOWNEAST SITES WITH CONDITIONS
SLOWLY IMPROVING TO VFR NRN TAF SITES BY SUN AFTN.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR THE INNER
WATERS UNTIL 9 AM, AND FOR THE OUTER WATERS UNTIL 6 PM. WINDS WILL
SUBSIDE THROUGH THE DAY, THOUGH SEAS WILL REMAIN ABOVE 5 FEET
THROUGH TONIGHT. THEREFORE THE CURRENT ADVISORY WILL LIKELY NEED TO
BE TRANSITIONED TO ONE FOR HAZARDOUS SEAS ONLY AT SOME POINT TODAY,
PARTICULARLY THE OUTER WATERS.
SHORT TERM: INITIALLY SCA SEAS FOR MSLY THE OUTER WATERS FOR FRI
MORN...WITH WV HTS SUBSIDING TO BLO SCA FRI AFTN. NO HDLNS LIKELY
NEEDED FOR FRI NGT AND SAT...WITH WINDS AND SEAS INCREASING TO SCA
BEHIND LOW PRES FOR ALL OF OUR MZS SUN NGT INTO MON.
&&
.CLIMATE...
THE RECORD HIGH TEMPERATURES FOR DECEMBER 24 ARE AS
FOLLOWS:
SITE RECORD HIGH YEAR CURRENT FORECAST
BANGOR 56 2003 55
CARIBOU 48 2003/2004 46
HOULTON 54 2004 48
MILLINOCKET 58 1911 50
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 AM EST THIS MORNING FOR ANZ052.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ050-
051.
&&
$$
NEAR TERM...HASTINGS
SHORT TERM...VJN
LONG TERM...VJN
AVIATION...HASTINGS/VJN
MARINE...HASTINGS/VJN
CLIMATE...
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1056 AM EST THU DEC 24 2015
.SYNOPSIS...
A COLD FRONT MOVES INTO THE REGION TODAY...REMAINING IN THE
VICINITY THROUGH THE WEEKEND AND INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 10 AM...APPROACHING COLD FRONT WAS IN WEST VIRGINIA. THE
FRONT IS PROGGED TO REACH DC METRO THIS AFTERNOON AND THEN SLOW
DOWN CONSIDERABLY WHILE BECOMING ORIENTED MORE EAST-WEST VERSUS
ITS CURRENT RATHER NORTH-SOUTH ORIENTATION. AS THIS
HAPPENS...THERE IS POTENTIAL FOR CONVECTION TO DEVELOP AND TRAVEL
PARALLEL TO THE FRONT...RESULTING IN A FLASH FLOOD RISK. THIS RISK
IS ENHANCED BY THE EXCEPTIONALLY HIGH PW AIR IN PLACE AT
PRESENT...THOUGH READINGS HAVE DIMINISHED A BIT FROM THEIR RECORD
VALUES LAST EVENING. FLASH FLOOD WATCH REMAINS IN EFFECT INTO THIS
EVENING.
OTHER CONCERN IS FOR ISOLATED SEVERE CONVECTION. THERE REMAINS
PLENTY OF WIND NOT FAR ABOVE THE SURFACE...SO ANY DOWNDRAFTS COULD
BRING STRONG GUSTS TO THE SURFACE. THE ISSUE IS LIMITED
CAPE...WHICH WILL KEEP DOWNDRAFTS FROM BECOMING VERY STRONG. THAT
SAID...ITS HARD TO IGNORE 40 KTS AT 850 AND 50+ AT 700. MARGINAL
RISK FROM SPC REMAINS IN PLACE.
ALL THAT HAVING BEEN SAID...SOME OF THE SHORT TERM MODELING SUCH
AS THE HRRR ARE BEGINNING TO SUGGEST THAT CONVECTION HAS NOW
PERMANENTLY SHIFTED SOUTHEAST OF THE DC/BALTIMORE METRO AREAS FOR
THE DURATION. IF WE BECOME MORE CONFIDENT IN THIS...ITS POSSIBLE
WE MAY DROP THE FLASH FLOOD WATCH...BUT AT THIS POINT CONFIDENCE
IS NOT HIGH.
NOT TO BE OVERSHADOWED BY THE OTHER CONCERNS FOR TODAY...RECORD
BREAKING TEMPERATURES ARE ONGOING TODAY WITH HIGHS PUSHING INTO
THE 70S. DID SIDE WITH A SLIGHTLY COOLER GUIDANCE WITH CLOUD COVER
AND PCPN EXPECTED THROUGH MOST...IF NOT ALL OF THE DAY. SO COULD
SEE TEMPS A FEW DEGREES WARMER IF SOME BREAKS OCCUR THIS AFTN.
ALL-TIME DECEMBER HIGHS LOOK OUT OF REACH...BUT ALL-TIME DECEMBER
MIN TEMPS ARE STILL QUITE POSSIBLE...PARTICULARLY AT DCA WHERE IT
IS ONLY 59. READINGS ARE LIKELY TO REMAIN IN THE 60S IN THE METRO
THROUGH MIDNIGHT.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
FRONT LIKELY TO SLIDE SOUTH ACROSS THE AREA ON FRIDAY. AIR MASS
BEHIND IT IS NOT IMMEDIATELY MUCH COLDER BUT SOME COOLER READINGS
APPEAR LIKELY AND WITH PLENTY OF CLOUD COVER ITS POSSIBLE WE
ACTUALLY STAY IN THE 60S. ANOTHER WAVE RIDES EAST FRIDAY NIGHT
WITH ANOTHER SHOT AT RAIN.
HIGH PRESSURE QUICKLY TRANSITIONS FROM THE GL TO NE FOR
SAT...RESULTING IN AN ELY FLOW DURING THE DAY. LOOKS LIKE THIS
WILL SHOVE THE SURFACE BOUNDARY TO OUR SOUTH AND ERLY FLOW NORTH
OF IT WILL KEEP TEMPS ON THE COOLER SIDE...THOUGH STILL VERY MUCH
ABV NORMAL. FEELING THAT TEMPS ON SAT COULD HAVE BUST POTENTIAL
WITH SO MUCH UNCERTAINTY ON EXACTLY WHERE THE BOUNDARY SETS
UP...SO LOW CONFIDENCE FOR TEMPS...WITH HIGHER CONFIDENCE THOUGH
OF PCPN OCCURRING (ALL RAIN).
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
BROAD ERN CONUS RDG REMAINS THRU THE XTNDD FCST...ALTHO THE AXIS
PROGGED TO BE SHUNTED A BIT INTO THE ATLC AS WEST COAST ENERGY
EJECTS ACRS THE CONUS. THERE ARE MANY UNRESOLVED FINE-SCALE DETAILS
LEADING INTO THE XTNDD. THUS...AM TAKING A BIG-PICTURE STANDPOINT...
UNDERSTANDING THIS SOLN LKLY TO CHG.
REGARDLESS...SUN LKLY TO BE ANOTHER VERY WARM DAY. CDFNT WL THEN
COME THRU...BRINGING NEAR NORMAL TEMPS TO THE AREA SUN NGT/MON--
SOMETHING WHICH HAS BEEN ANYTHING BUT NORMAL RECENTLY. AM CARRYING
CHC POPS THRUT...THO IT/LL BE A TIMING/PLACEMENT ISSUE. SUSPECT
THERE WL BE A DRY PD POST-FROPA MON.
GFS/ECMWF BOTH SUGGEST THAT ANOTHER LOPRES WL EJECT FM THE SRN
PLAINS INTO THE GRTLKS TUE-WED. THAT WOULD BRING ANOTHER PAIR OF
FRONTS /WMFNT THEN CDFNT/ AND THEREFORE MORE PCPN CHCS. AT THIS
POINT AM KEEPING TEMPS ABV NORMAL BUT CLSR TO AVG THAN RECENT PAST.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
MVFR CIGS RETURNED THIS MORNING...BUT IMPROVE AGAIN THIS AFTN.
SHOWERS COULD BRING MOD-HEAVY RAIN AND BRIEF REDUCTIONS BACK TO
MVFR/IFR...ALONG WITH STRONG WINDS GUSTING 30-40 KTS. AN ISO TSTM
CANNOT BE RULED OUT EITHER.
LOW CONFIDENCE ON THE CONDITIONS TONIGHT WITH UNCERTAINTY ON WHERE
THE FRONT WILL END UP. RIGHT NOW GOING WITH MVFR VIS/IFR CIGS...BUT
COULD VERY WELL END UP SEEING EVEN LOWER. ANY PCPN SHOULD TAPER OFF
BY 03Z.
ANOTHER DAY OF SUB-VFR CONDITIONS AND RAIN FRIDAY WITH THE BOUNDARY
NEARBY. THESE CONDITIONS WILL CONTINUE INTO SAT. WINDS HOWEVER WILL
BE ON THE WEAKER SIDE...LESS THAN 10 KTS.
SUN-MON...CFP DURING THIS TIMEFRAME /MOST LKLY SUN PM/ WHICH WUD
BRING FLGT RESTRICTIONS. CONFIDENCE IN RESTRICTIONS OUTSIDE OF
THIS WINDOW LOW.
&&
.MARINE...
SCA CONDITIONS ON ALL WATERS TODAY. SMW MAY BE NEEDED THIS AFTN
WITH SHOWERS AND ISO TSTMS FORMING AHEAD OF AN APPROACHING FRONT.
BY TONIGHT...WINDS TAPER OFF GREATLY...WITH SCA GUSTS ONLY
PERSISTING ON THE CHESAPEAKE BAY THRU 06Z. SUB-SCA CONDITIONS THEN
THE LATTER HALF OF THE NIGHT THRU FRI NIGHT. MAY GO BACK TO SCA AS
BOUNDARY SHIFT SOUTH OF THE AREA AND STIFF ERLY FLOW DEVELOPS OVER
THE WATERS SATURDAY.
CDFNT APPROACHES SUN AND CROSSES WATERS SUN NGT. HV SLY WINDS
INCRSG AHD OF FNT FLLWD BY GOOD MIXING BHD IT. SCA PSBL W/IN THIS
WINDOW.
&&
.CLIMATE...
THE DEC 24 DAILY RECORDS...BOTH HIGHS AND HIGH MINS...
IAD...66 IN 1982...HIGH MIN 42 IN 2014...HIGH ALREADY BROKEN.
DCA...69 IN 1933...HIGH MIN 58 IN 1891...HIGH ALREADY BROKEN.
BWI...HIGH 65 IN 1990 AND 1982...HIGH MIN 53 IN 1891...HIGH
ALREADY BROKEN.
HIGH MINS ARE NOT OFFICIAL UNTIL MIDNIGHT BUT ALL LOOK
LIKELY TO BE BROKEN.
DEC MONTHLY RECORDS...BOTH HIGHS AND HIGH MINS...
IAD...HIGH 79 ON 12/6/1998...HIGH MIN 62 ON 12/22/2013
DCA...HIGH 79 ON 12/7/1998...HIGH MIN 59 ON 12/5/1973
BWI...HIGH 77 ON 12/7/1998, 12/6/1998 AND 12/29/1984...HIGH MIN 62
ON 12/22/2013
HIGHS ARE NOT EXPECTED TO BE BROKEN TODAY BUT HIGH MINS ARE VERY
POSSIBLE...ESPECIALLY DCA.
WARMEST DECEMBER AVERAGE TEMPERATURE THROUGH THE 23RD...
DCA...50.5 /2001/...50.2 /1998/...49.6 /2015/.
BWI...47.2 /1998/...47.1 /2001/...46.9 /2015/.
IAD...47.2 /1998/...46.5 /TIE 2001 AND 2015/.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...FLASH FLOOD WATCH UNTIL 9 PM EST THIS EVENING FOR DCZ001.
MD...FLASH FLOOD WATCH UNTIL 9 PM EST THIS EVENING FOR MDZ011-013-
014-504-506.
VA...FLASH FLOOD WATCH UNTIL 9 PM EST THIS EVENING FOR VAZ052>054.
WV...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ532-
533-540>542.
SMALL CRAFT ADVISORY UNTIL 1 AM EST FRIDAY FOR ANZ534-537-543.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR ANZ530-
531-535-536-538-539.
&&
$$
SYNOPSIS...HTS
NEAR TERM...SEARS/RCM
SHORT TERM...SEARS/RCM
LONG TERM...HTS
AVIATION...SEARS/HTS/RCM
MARINE...SEARS/HTS/RCM
CLIMATE...DFH/RCM
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1011 AM EST THU DEC 24 2015
.UPDATE...
STRONG LOW PRESSURE...971 MB...HAS LIFTED FROM NORTH OF LAKE
SUPERIOR INTO ST JAMES BY THIS MORNING. HIGH PRESSURE MEANWHILE
HAS BEEN PROGRESSIVELY BUILDING INTO THE OHIO VALLEY AND NEW
ENGLAND...EXPANDING UP TOWARDS THE CENTRAL AND SOUTHERN GREAT
LAKES AS THE LOW LIFTS NORTHWARD. THIS TREND WILL CONTINUE
TODAY...ALLOWING THE SURFACE PRESSURE GRADIENT TO CONTINUE
DECREASING ACROSS THE AREA. STRONGER CORE OF WINDS ALOFT WILL ALSO
EXIT NORTHEAST WITH THE UPPER SYSTEM...ENDING POTENTIAL FOR
STRONGER GUSTS TO MIX DOWN TO THE SURFACE AS WE HEAD INTO THE
AFTERNOON. WIND ADVISORY WAS DROPPED EARLIER TODAY...AND EXPECT
LIGHT WINDS BY MID-EVENING.
&&
.AVIATION...ISSUED 653 AM EST THU DEC 24 2015
ALMOST DUE MERIDIONAL TRAJECTORY OF POWERFUL LOW PRESSURE SYSTEM
TRACKING AWAY FROM SOUTHEASTERN MICHIGAN WILL ALLOW THE PRESSURE
GRADIENT TO SLACKEN QUICKLY THIS MORNING. BEEN WITNESSING A STEADY
WEAKENING TREND FOR SURFACE WINDS...WHICH WILL CONTINUE DURING THE
FIRST COUPLE HOURS OF THE TAF PERIOD. MODELS SHOW TRAPPED MOISTURE
BELOW SUBSIDENCE INVERSION IN CYCLONIC FLOW TODAY. THIS MOISTURE
IS EXPECTED TO EVOLVE INTO A DIURNAL STRATOCUMULUS FIELD. WITH THE
ABUNDANCE OF OBSERVED MVFR CIGS/MOISTURE AROUND 3.0 KFT AGL...AND
LATEST DATA FROM EXPERIMENTAL HRRR AND RUC...DECIDED TO GO MORE
BEARISH WITH RESPECT TO CLOUDS TODAY. EXPECTING THE LOW CLOUD TO
VANISH PRETTY RAPIDLY LATE AFTERNOON WITH LOSS OF DIURNAL
SUPPORT...BUT MID CLOUD FROM COLORADO SHORTWAVE WILL BE RAPIDLY
APPROACHING. UNCERTAINTY EXISTS SURROUNDING PRECIPITATION
POTENTIAL TONIGHT. DID ADD IT IN THE NORTH GIVEN QUALITY OF
MOISTURE ALOFT. HOWEVER...SYNOPTIC SCALE WILL NOT BE FAVORABLE FOR
ASCENT.
FOR DTW...WEST SOUTHWEST SURFACE WINDS HAVE ALREADY SETTLED DOWN
INTO THE 15 TO 25 KNOT RANGE. UNCERTAINTIES FOR THE DTW FORECAST ARE
WHETHER OR NOT MVFR CIGS WILL BUILD SOUTH AND EAST AND SUBSEQUENT TIMING.
MODELS SUPPORT IT WILL...AROUND THE TIME CLOUD EVOLVES INTO
STRATOCUMULUS DURING THE AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* MODERATE FOR CEILING BELOW 5000 FEET FOR TODAY.
&&
.PREV DISCUSSION...ISSUED 348 AM EST THU DEC 24 2015
DISCUSSION...
.WIND ADVISORY CONTINUES THROUGH MID MORNING...
INTENSE LOW PRESSURE (974 MB AT 3 AM) OVER NORTHERN ONTARIO WILL
CONTINUE TO PULL AWAY FROM THE GREAT LAKES REGION TODAY. ASSOCIATED
COLD FRONT PASSAGE AND MID LEVEL DRY SLOT IMPACTING SOUTHEAST
MICHIGAN AT PRESS TIME...AND OBSERVATIONS CONTINUE TO SUPPORT 45 MPH
TO 55 MPH WIND GUSTS...HIGHEST GUSTS NORTH OF I-69 WHERE MAX
PRESSURE GRADIENT/COLD ADVECTION EXISTS DUE TO THE LOW PULLING OFF
NORTH-NORTHEAST TOWARD JAMES BAY. WINDS WILL DROP OFF QUICKLY...AND
MAY BE ABLE TO CANCEL THE ADVISORY EARLY...ESPECIALLY SOUTH.
TEMPERATURES IN THE MID 50S TO AROUND 60 DEGREES AS OF 3 AM LOOK TO
BE DROPPING INTO THE MID TO UPPER 40S TOWARD 12Z...WHICH LOOKS TO BE
IN THE BALL PARK OF MAXES. TEMPERATURES COULD CONTINUE TO FALL
DURING THE MORNING HOURS BEFORE MAKING A MODEST RECOVERY DURING THE
AFTERNOON WITH LATE DECEMBER SUNSHINE.
A BIT OF A NUISANCE FORECAST TONIGHT AS UPPER WAVE COMING OUT OF
COLORADO THIS MORNING WILL STREAK NORTHEAST AND SHEAR OUT...RUNNING
INTO MOSTLY UPPER LEVEL CONFLUENT FLOW OVER THE CENTRAL GREAT
LAKES...AS SURFACE HIGH (1022 MB) TRACKS INTO SOUTHERN LOWER
MICHIGAN. HOWEVER...MID LEVEL FGEN/ISENTROPIC ASCENT WITH THE UPPER
WAVE MAY BE SUFFICIENT TO GENERATE PRECIPITATION (ABOUT 4 G/KG OF
SPECIFIC HUMIDITY TO WORK WITH)...BUT WILL HAVE TO OVERCOME DRY AND
RELATIVELY MILD LOW LEVELS (925 MB TEMPS OF ZERO TO 4 C RANGE). BOTH
00Z NAM AND EURO INDICATING SOME LIGHT QPF...BUT DIFFERENT
LOCATIONS...AND WILL CARRY LOW CHANCE POPS FOR SOME LIGHT RAIN OR
SPRINKLES. THINKING PRECIPITATION TYPE WILL BE PREDOMINATELY RAIN
DUE TO LIGHT PRECIPITATION RATES...PREVENTING SUFFICIENT WET BULB
COOLING. CLOUDS EXPECTED TO HOLD SURFACE TEMPS IN THE 30S.
WATER VAPOR IMAGERY SHOWS VERY IMPRESSIVE UPPER LEVEL WAVE/ENERGY
JUST OFF THE COAST OF THE PACIFIC NORTHWEST...WITH THE BULK OF THIS
PV/ENERGY SETTLING OVER THE FOUR CORNERS/NORTHERN MEXICO OVER THE
WEEKEND. SPLIT UPPER LEVEL FLOW WITH A NORTHERN STREAM SHORTWAVE
TROUGH STILL ON TRACK TO SLIDE THROUGH THE GREAT LAKES REGION ON
SUNDAY. A WAVE OF LOW PRESSURE PRECEDING THIS TROUGH WILL MOVE
THROUGH FAR SOUTHERN LOWER MICHIGAN ON SATURDAY...DRAWING UP A LOT
OF WARMTH AND MOISTURE AGAIN...AS 850 MB DEW PTS REACH 10 C ONCE
AGAIN...PER 00Z EURO. THIS AMOUNT OF LOW LEVEL MOISTURE IS RECORD
SETTING FOR THE END OF DECEMBER PER SPC SOUNDING CLIMATOLOGY PAGE.
ALTHOUGH RAIN DEVELOPING SATURDAY AFTERNOON/EVENING IS LIKELY TO
DEFINITE...PUNCHING INTO THE WARM SECTOR IS A BIT MORE
UNCERTAIN...AND THUS MAXES WILL BE FORECASTED MORE
CONSERVATIVELY...MID 40S TO AROUND 50 DEGREES. OBVIOUSLY LOCATIONS
TOWARD THE OHIO BORDER STAND BEST CHANCE TO PUNCH WELL ABOVE 50
DEGREES...BUT THAT MAY NOT OCCUR UNTIL SATURDAY EVENING.
STRONG COLD ADVECTION WILL TAKE PLACE FOR THE SECOND HALF OF THE
WEEKEND BEHIND THE SURFACE WAVE...AS STRONG HIGH (1045 MB) BUILDS
OVER ONTARIO SUNDAY NIGHT. THIS HIGH LOOKS TO SUPPLY/MAINTAIN COLD
LOW LEVEL FEED EARLY NEXT WEEK WHILE THE PREVIOUS MENTIONED FOUR
CORNERS SYSTEM EJECTS NORTHEAST...POTENTIALLY REACHING THE WESTERN
GREAT LAKES ON TUESDAY...PER 00Z EURO. THIS SCENARIO WOULD IMPLY A
PERIOD OF FREEZING RAIN BEFORE CHANGEOVER TO RAIN...WHILE THE 00Z
CANADIAN IS FARTHER SOUTH AND IMPLIES SNOW. MIXED GFS ENSEMBLE
MEMBERS GIVE CREDENCE TO BOTH SOLUTIONS...SO CERTAINLY POSSIBLE WE
WILL HAVE A WINTRY MESS/MIX ON OUR HANDS.
MARINE...
POWERFUL SURFACE LOW PRESSURE...NOW NORTH OF LAKE SUPERIOR...WILL
RAPIDLY LIFT NORTHWARD TO JAMES BAY. A STRONG COLD FRONT WILL SURGE
ACROSS SOUTHEASTERN MICHIGAN DURING THE FIRST HOUR OR TWO OF THE
FORECAST PERIOD AND ACROSS LAKE HURON BY 12Z. POST FRONTAL SURFACE
WINDS HAVE CERTAINLY BEEN ROBUST WITH SOME SFC OBSERVATIONS ON LAND
OVER LOWER MICHIGAN PUSHING/REACHING 50 KNOTS AT TIMES. BEST
ISALLOBARIC SUPPORT WILL PUSH NORTHWARD ALONG LAKE MICHIGAN...BUT
ENOUGH GRADIENT FLOW WITH STEEPENING LOW LEVEL LAPSE RATES WILL
SUPPORT A HIGH END GALE EVENT OF 45 KNOTS OVER SAGINAW BAY AND THE
NORTHERN LAKE HURON BASIN. FARTHER SOUTH...GALE FORCE WINDS OF 40
KNOTS WILL BE POSSIBLE. THE ROBUST WIND FIELD IS EXPECTED TO BE
RATHER SHORT LIVED WITH DIMINISHING WINDS EXPECTED DURING THE REST
OF THE DAY. WIND GUSTS OVER LAKE HURON ARE EXPECTED TO DROP BELOW 20
KNOTS BY 06Z FRIDAY. A BRIEF SURFACE RIDGE WILL BUILD INTO THE
REGION FOR FRIDAY BEFORE THE NEXT LOW PRESSURE SYSTEM SET ITS SIGHTS
ON THE MICHIGAN OHIO BORDER FOR SATURDAY NIGHT. MODELS ARE SHOWING
LEGITIMATE COLD AIR ADVECTION OCCURRING DOWN INTO THE SOUTHERN
GREAT LAKES FOR A TIME SUNDAY NIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LHZ361>363-421-441-
462.
SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 7 PM EST THIS
EVENING FOR LHZ421-441.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LHZ442-443.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR LHZ422.
GALE WARNING UNTIL NOON EST TODAY FOR LHZ422.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......HLO
AVIATION.....CB
DISCUSSION...SF
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
653 AM EST THU DEC 24 2015
.AVIATION...
ALMOST DUE MERIDIONAL TRAJECTORY OF POWERFUL LOW PRESSURE SYSTEM
TRACKING AWAY FROM SOUTHEASTERN MICHIGAN WILL ALLOW THE PRESSURE
GRADIENT TO SLACKEN QUICKLY THIS MORNING. BEEN WITNESSING A STEADY
WEAKENING TREND FOR SURFACE WINDS...WHICH WILL CONTINUE DURING THE
FIRST COUPLE HOURS OF THE TAF PERIOD. MODELS SHOW TRAPPED MOISTURE
BELOW SUBSIDENCE INVERSION IN CYCLONIC FLOW TODAY. THIS MOISTURE
IS EXPECTED TO EVOLVE INTO A DIURNAL STRATOCUMULUS FIELD. WITH THE
ABUNDANCE OF OBSERVED MVFR CIGS/MOISTURE AROUND 3.0 KFT AGL...AND
LATEST DATA FROM EXPERIMENTAL HRRR AND RUC...DECIDED TO GO MORE
BEARISH WITH RESPECT TO CLOUDS TODAY. EXPECTING THE LOW CLOUD TO
VANISH PRETTY RAPIDLY LATE AFTERNOON WITH LOSS OF DIURNAL
SUPPORT...BUT MID CLOUD FROM COLORADO SHORTWAVE WILL BE RAPIDLY
APPROACHING. UNCERTAINTY EXISTS SURROUNDING PRECIPITATION
POTENTIAL TONIGHT. DID ADD IT IN THE NORTH GIVEN QUALITY OF
MOISTURE ALOFT. HOWEVER...SYNOPTIC SCALE WILL NOT BE FAVORABLE FOR
ASCENT.
FOR DTW...WEST SOUTHWEST SURFACE WINDS HAVE ALREADY SETTLED DOWN
INTO THE 15 TO 25 KNOT RANGE. UNCERTAINTIES FOR THE DTW FORECAST ARE
WHETHER OR NOT MVFR CIGS WILL BUILD SOUTH AND EAST AND SUBSEQUENT TIMING.
MODELS SUPPORT IT WILL...AROUND THE TIME CLOUD EVOLVES INTO
STRATOCUMULUS DURING THE AFTERNOON.
//DTW THRESHOLD PROBABILITIES...
* MODERATE FOR CEILING BELOW 5000 FEET FOR TODAY.
&&
.PREV DISCUSSION...ISSUED 348 AM EST THU DEC 24 2015
DISCUSSION...
..WIND ADVISORY CONTINUES THROUGH MID MORNING...
INTENSE LOW PRESSURE (974 MB AT 3 AM) OVER NORTHERN ONTARIO WILL
CONTINUE TO PULL AWAY FROM THE GREAT LAKES REGION TODAY. ASSOCIATED
COLD FRONT PASSAGE AND MID LEVEL DRY SLOT IMPACTING SOUTHEAST
MICHIGAN AT PRESS TIME...AND OBSERVATIONS CONTINUE TO SUPPORT 45 MPH
TO 55 MPH WIND GUSTS...HIGHEST GUSTS NORTH OF I-69 WHERE MAX
PRESSURE GRADIENT/COLD ADVECTION EXISTS DUE TO THE LOW PULLING OFF
NORTH-NORTHEAST TOWARD JAMES BAY. WINDS WILL DROP OFF QUICKLY...AND
MAY BE ABLE TO CANCEL THE ADVISORY EARLY...ESPECIALLY SOUTH.
TEMPERATURES IN THE MID 50S TO AROUND 60 DEGREES AS OF 3 AM LOOK TO
BE DROPPING INTO THE MID TO UPPER 40S TOWARD 12Z...WHICH LOOKS TO BE
IN THE BALL PARK OF MAXES. TEMPERATURES COULD CONTINUE TO FALL
DURING THE MORNING HOURS BEFORE MAKING A MODEST RECOVERY DURING THE
AFTERNOON WITH LATE DECEMBER SUNSHINE.
A BIT OF A NUISANCE FORECAST TONIGHT AS UPPER WAVE COMING OUT OF
COLORADO THIS MORNING WILL STREAK NORTHEAST AND SHEAR OUT...RUNNING
INTO MOSTLY UPPER LEVEL CONFLUENT FLOW OVER THE CENTRAL GREAT
LAKES...AS SURFACE HIGH (1022 MB) TRACKS INTO SOUTHERN LOWER
MICHIGAN. HOWEVER...MID LEVEL FGEN/ISENTROPIC ASCENT WITH THE UPPER
WAVE MAY BE SUFFICIENT TO GENERATE PRECIPITATION (ABOUT 4 G/KG OF
SPECIFIC HUMIDITY TO WORK WITH)...BUT WILL HAVE TO OVERCOME DRY AND
RELATIVELY MILD LOW LEVELS (925 MB TEMPS OF ZERO TO 4 C RANGE). BOTH
00Z NAM AND EURO INDICATING SOME LIGHT QPF...BUT DIFFERENT
LOCATIONS...AND WILL CARRY LOW CHANCE POPS FOR SOME LIGHT RAIN OR
SPRINKLES. THINKING PRECIPITATION TYPE WILL BE PREDOMINATELY RAIN
DUE TO LIGHT PRECIPITATION RATES...PREVENTING SUFFICIENT WET BULB
COOLING. CLOUDS EXPECTED TO HOLD SURFACE TEMPS IN THE 30S.
WATER VAPOR IMAGERY SHOWS VERY IMPRESSIVE UPPER LEVEL WAVE/ENERGY
JUST OFF THE COAST OF THE PACIFIC NORTHWEST...WITH THE BULK OF THIS
PV/ENERGY SETTLING OVER THE FOUR CORNERS/NORTHERN MEXICO OVER THE
WEEKEND. SPLIT UPPER LEVEL FLOW WITH A NORTHERN STREAM SHORTWAVE
TROUGH STILL ON TRACK TO SLIDE THROUGH THE GREAT LAKES REGION ON
SUNDAY. A WAVE OF LOW PRESSURE PRECEDING THIS TROUGH WILL MOVE
THROUGH FAR SOUTHERN LOWER MICHIGAN ON SATURDAY...DRAWING UP A LOT
OF WARMTH AND MOISTURE AGAIN...AS 850 MB DEW PTS REACH 10 C ONCE
AGAIN...PER 00Z EURO. THIS AMOUNT OF LOW LEVEL MOISTURE IS RECORD
SETTING FOR THE END OF DECEMBER PER SPC SOUNDING CLIMATOLOGY PAGE.
ALTHOUGH RAIN DEVELOPING SATURDAY AFTERNOON/EVENING IS LIKELY TO
DEFINITE...PUNCHING INTO THE WARM SECTOR IS A BIT MORE
UNCERTAIN...AND THUS MAXES WILL BE FORECASTED MORE
CONSERVATIVELY...MID 40S TO AROUND 50 DEGREES. OBVIOUSLY LOCATIONS
TOWARD THE OHIO BORDER STAND BEST CHANCE TO PUNCH WELL ABOVE 50
DEGREES...BUT THAT MAY NOT OCCUR UNTIL SATURDAY EVENING.
STRONG COLD ADVECTION WILL TAKE PLACE FOR THE SECOND HALF OF THE
WEEKEND BEHIND THE SURFACE WAVE...AS STRONG HIGH (1045 MB) BUILDS
OVER ONTARIO SUNDAY NIGHT. THIS HIGH LOOKS TO SUPPLY/MAINTAIN COLD
LOW LEVEL FEED EARLY NEXT WEEK WHILE THE PREVIOUS MENTIONED FOUR
CORNERS SYSTEM EJECTS NORTHEAST...POTENTIALLY REACHING THE WESTERN
GREAT LAKES ON TUESDAY...PER 00Z EURO. THIS SCENARIO WOULD IMPLY A
PERIOD OF FREEZING RAIN BEFORE CHANGEOVER TO RAIN...WHILE THE 00Z
CANADIAN IS FARTHER SOUTH AND IMPLIES SNOW. MIXED GFS ENSEMBLE
MEMBERS GIVE CREDENCE TO BOTH SOLUTIONS...SO CERTAINLY POSSIBLE WE
WILL HAVE A WINTRY MESS/MIX ON OUR HANDS.
MARINE...
POWERFUL SURFACE LOW PRESSURE...NOW NORTH OF LAKE SUPERIOR...WILL
RAPIDLY LIFT NORTHWARD TO JAMES BAY. A STRONG COLD FRONT WILL SURGE
ACROSS SOUTHEASTERN MICHIGAN DURING THE FIRST HOUR OR TWO OF THE
FORECAST PERIOD AND ACROSS LAKE HURON BY 12Z. POST FRONTAL SURFACE
WINDS HAVE CERTAINLY BEEN ROBUST WITH SOME SFC OBSERVATIONS ON LAND
OVER LOWER MICHIGAN PUSHING/REACHING 50 KNOTS AT TIMES. BEST
ISALLOBARIC SUPPORT WILL PUSH NORTHWARD ALONG LAKE MICHIGAN...BUT
ENOUGH GRADIENT FLOW WITH STEEPENING LOW LEVEL LAPSE RATES WILL
SUPPORT A HIGH END GALE EVENT OF 45 KNOTS OVER SAGINAW BAY AND THE
NORTHERN LAKE HURON BASIN. FARTHER SOUTH...GALE FORCE WINDS OF 40
KNOTS WILL BE POSSIBLE. THE ROBUST WIND FIELD IS EXPECTED TO BE
RATHER SHORT LIVED WITH DIMINISHING WINDS EXPECTED DURING THE REST
OF THE DAY. WIND GUSTS OVER LAKE HURON ARE EXPECTED TO DROP BELOW 20
KNOTS BY 06Z FRIDAY. A BRIEF SURFACE RIDGE WILL BUILD INTO THE
REGION FOR FRIDAY BEFORE THE NEXT LOW PRESSURE SYSTEM SET ITS SIGHTS
ON THE MICHIGAN OHIO BORDER FOR SATURDAY NIGHT. MODELS ARE SHOWING
LEGITIMATE COLD AIR ADVECTION OCCURRING DOWN INTO THE SOUTHERN
GREAT LAKES FOR A TIME SUNDAY NIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WIND ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ047>049-053>055-
060>063-068>070-075-076-082-083.
LAKE HURON...GALE WARNING UNTIL NOON EST TODAY FOR LHZ421-422-441-462.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LHZ442-443-463-464.
GALE WARNING UNTIL 3 PM EST THIS AFTERNOON FOR LHZ361>363.
LAKE ST CLAIR...GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LCZ460.
MICHIGAN WATERS OF LAKE ERIE...GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LEZ444.
&&
$$
AVIATION.....CB
DISCUSSION...SF
MARINE.......CB
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
940 AM CST THU DEC 24 2015
.UPDATE...
ISSUED AT 932 AM CST THU DEC 24 2015
930 AM SNOW TOTAL AT THE VALLEY WEATHER OFFICE IS 3.8 INCHES AND
STILL COMING DOWN NICELY.
RADAR TRENDS HAVE HIGHEST REFLECTIVITIES FROM SOUTHEAST SAUNDERS
THROUGH NORTHERN SARPY...ALL OF DOUGLAS AND INTO NORTHERN
POTTAWATTAMIE COUNTIES AS OF 930 AM. EXPECT THIS HEAVIEST BAND TO
GRADUALLY WORK EAST OF THE MISSOURI RIVER THROUGH 11 AM WITH A
MARKED DECLINE IN ACTIVITY IN NEBRASKA COUNTIES BY NOON OR SO.
LATEST HRRR FORECASTS BEAR THIS OUT...BUT SNOWFALL OF AN PER HOUR
UNTIL THEN WILL PUT SNOW TOTALS INTO THE 5 TO 6 INCH RANGE FOR
PARTS OF THE OMAHA AND COUNCIL BLUFFS METRO. HAVE UPDATED OUR
FORECAST TO REFLECT THIS.
UPDATE ISSUED AT 844 AM CST THU DEC 24 2015
SNOW CONTINUES OVER MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA.
RADAR TRENDS OVER THE LAST HOUR OR SO SHOW MOST INTENSE SNOWFALL
OCCURRING FROM THE NORTH SIDE OF LINCOLN TO OMAHA AND COUNCIL
BLUFFS. MULTIPLE REPORTS OF 2 INCH ACCUMULATIONS FROM LINCOLN TO
OMAHA AS OF 830 AM. ANOTHER 2 INCHES ARE LIKELY IN THE HEAVIEST
BANDS THROUGH 11 AM OR SO. ALREADY SEEING SNOW ENDING IN SOUTH
CENTRAL NEBRASKA JUST WEST OF FAIRBURY AND YORK...AND TOTAL
SNOWFALL OF 3.5 INCHES WERE RECEIVED IN PARTS OF THOSE AREAS. SO
WOULD EXPECT TOTALS HERE TO REACH THAT 3 TO 4 INCH RANGE RATHER
EASILY...WITH LESSER AMOUNTS CLOSER TO AN INCH BY NORFOLK ON
FRINGE OF SNOW BAND...AND IN FAR SOUTHEAST NEBRASKA AND FAR
SOUTHWEST IOWA WHERE TEMPERATURES ARE AT OR ABOVE FREEZING AND
SOME RAIN/SLEET IS MIXING IN.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 520 AM CST THU DEC 24 2015
SNOW WILL AFFECT THE TAF SITES THIS MORNING...WITH LOWEST CIGS AND
VSBYS EXPECTED AT KLNK AND KOMA. VSBYS MAY DROP TO UNDER 1 MILE...
FROM MID MORNING THROUGH MID DAY. CONDITIONS SHOULD IMPROVE MID
TO LATE AFTERNOON WITH MAINLY VFR CONDITIONS THEN BY THIS EVENING.
NAM MODEL HOLDS ONTO LOW CLOUDS A BIT LONGER...SO WILL HAVE TO
MONITOR TRENDS FOR LATER TAFS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NEZ034-
045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR IAZ043-
055-056-069-079.
&&
$$
UPDATE...DERGAN
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
851 AM CST THU DEC 24 2015
.UPDATE...
ISSUED AT 844 AM CST THU DEC 24 2015
SNOW CONTINUES OVER MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA.
RADAR TRENDS OVER THE LAST HOUR OR SO SHOW MOST INTENSE SNOWFALL
OCCURRING FROM THE NORTH SIDE OF LINCOLN TO OMAHA AND COUNCIL
BLUFFS. MULTIPLE REPORTS OF 2 INCH ACCUMULATIONS FROM LINCOLN TO
OMAHA AS OF 830 AM. ANOTHER 2 INCHES ARE LIKELY IN THE HEAVIEST
BANDS THROUGH 11 AM OR SO. ALREADY SEEING SNOW ENDING IN SOUTH
CENTRAL NEBRASKA JUST WEST OF FAIRBURY AND YORK...AND TOTAL
SNOWFALL OF 3.5 INCHES WERE RECEIVED IN PARTS OF THOSE AREAS. SO
WOULD EXPECT TOTALS HERE TO REACH THAT 3 TO 4 INCH RANGE RATHER
EASILY...WITH LESSER AMOUNTS CLOSER TO AN INCH BY NORFOLK ON
FRINGE OF SNOW BAND...AND IN FAR SOUTHEAST NEBRASKA AND FAR
SOUTHWEST IOWA WHERE TEMPERATURES ARE AT OR ABOVE FREEZING AND
SOME RAIN/SLEET IS MIXING IN.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 520 AM CST THU DEC 24 2015
SNOW WILL AFFECT THE TAF SITES THIS MORNING...WITH LOWEST CIGS AND
VSBYS EXPECTED AT KLNK AND KOMA. VSBYS MAY DROP TO UNDER 1 MILE...
FROM MID MORNING THROUGH MID DAY. CONDITIONS SHOULD IMPROVE MID
TO LATE AFTERNOON WITH MAINLY VFR CONDITIONS THEN BY THIS EVENING.
NAM MODEL HOLDS ONTO LOW CLOUDS A BIT LONGER...SO WILL HAVE TO
MONITOR TRENDS FOR LATER TAFS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NEZ034-
045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR IAZ043-
055-056-069-079.
&&
$$
UPDATE...DERGAN
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
520 AM CST THU DEC 24 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(12Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 520 AM CST THU DEC 24 2015
SNOW WILL AFFECT THE TAF SITES THIS MORNING...WITH LOWEST CIGS AND
VSBYS EXPECTED AT KLNK AND KOMA. VSBYS MAY DROP TO UNDER 1 MILE...
FROM MID MORNING THROUGH MID DAY. CONDITIONS SHOULD IMPROVE MID
TO LATE AFTERNOON WITH MAINLY VFR CONDITIONS THEN BY THIS EVENING.
NAM MODEL HOLDS ONTO LOW CLOUDS A BIT LONGER...SO WILL HAVE TO
MONITOR TRENDS FOR LATER TAFS.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NEZ034-
045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR IAZ043-
055-056-069-079.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...MILLER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
432 AM CST THU DEC 24 2015
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(06Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1120 PM CST WED DEC 23 2015
FORECAST REMAINS ON TRACK WITH MINOR TWEAKS NEEDED. VFR CONDITIONS...
BECOMING MVFR AND EVENTUALLY IFR AS SNOW MOVES INTO ALL 3 TAF
SITES BY 11-13Z. VISIBILITY COULD DROP AS LOW AS 1 MILE AT TIMES
KLNK/KOMA MID MORNING THROUGH EARLY AFTERNOON...THEN SNOW ENDING
BY 19-21Z. STILL LOOKING AT LIGHT ACCUMULATIONS OF 1 TO 3 INCHES
ACROSS THE AREA...BUT SOME OF THAT WILL BE MELTING ON WARM
GROUND...AS DAYTIME TEMPERATURES CLIMB INTO THE MID 30S. WINDS
REMAIN LIGHT GENERALLY LESS THAN 7 KNOTS THROUGH THE PERIOD.
TRANSITIONING BACK TO VFR BY 22-03Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 2 PM CST THIS
AFTERNOON FOR NEZ034-045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 2 PM CST THIS
AFTERNOON FOR IAZ043-055-056-069-079.
&&
$$
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...DEWALD
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
655 AM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO PA
THROUGH THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR LOOP AT 10Z SHOWING A WEAKENING LINE OF CONVECTION MOVING
THROUGH CENTRAL PA ALONG AXIS OF LL JET. SFC ANALYSIS INDICATES
COLD FRONT IS LAGGING TO THE WEST ACROSS EASTERN OHIO. RADAR
TRENDS AND LATEST HRRR SUPPORT THE IDEA OF THIS BAND OF SCT
SHOWERS PROGRESSES EASTWARD ACROSS THE REGION THIS MORNING...EXITING
ALL BUT EXTREME SE PA BY MIDDAY.
ALTHOUGH NO LIGHTNING STRIKES NOTED AT 10Z...WILL CONTINUE TO
MENTION A SLIGHT CHC OF THUNDER COINCIDENT WITH FROPA LATE
AM/EARLY AFTN ACROSS THE SE COUNTIES...WHERE MDLS DEVELOP SOME
MODEST CAPES.
GUIDANCE STILL SUGGESTING CLEARING SKIES WILL OVERSPREAD MUCH OF
CENTRAL PA BY AFTN...AS SFC RIDGING AND LOWER PWAT AIR MASS
ARRIVES BEHIND COLD FRONT. CLOUDS AND THE LINGERING CHC OF A
SHOWER MAY PERSIST THRU EVENING ACROSS THE SOUTHEAST IN THE
VICINITY OF STALLED OUT FRONT.
THE BIGGEST STORY OF THIS CHRISTMAS EVE REMAINS THE RECORD
BREAKING TEMPS. RECORDS HAVE ALREADY FALLEN AT KBFD/KIPT/KMDT AND
ARE VERY LIKELY TO FALL AT KAOO/KUNV. SREF PLUMES INDICATE STEADY
OR SLOWLY FALLING TEMPS TODAY ACROSS THE NW MTNS...WHERE FROPA
WILL OCCUR EARLY IN THE DAY. HOWEVER...READINGS SHOULD RISE
SEVERAL DEGREES ELSEWHERE...WITH SUPERBLEND AND ECME MOS
SUPPORTING MAX TEMPS FROM ARND 60F ACROSS THE NW MTNS...TO ARND
70F OVR THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD PROVIDE
FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T RULE OUT A FEW EVENING SHOWERS ASSOC WITH WEAK
WAVE OF LOW PRES RIDING ALONG STALLED FRONTAL BNDRY. LIKEWISE...A
WEAK SHORTWAVE RIDING ACROSS THE GRT LKS COULD SUPPORT AN ISOLD
SHOWER TOWARD DAWN OVR THE NW MTNS.
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA COULD
SPREAD A BIT OF LGT RAIN INTO THE SOUTHERN PART OF THE STATE
DURING THE PM HOURS OF CHRISTMAS DAY. BLEND OF ENSEMBLE/OPER MDL
DATA SUPPORTS CHC POPS ACROSS THE SOUTHERN TIER AND SLGHT CHC OVR
THE NORTHERN HALF OF THE STATE. OTHERWISE...BIG STORY WILL
CONTINUE TO BE THE MILD WX. GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN
VERY WARM FOR DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE L50S
ACROSS THE NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS UPPER RIDGE OFF THE EAST COAST WILL CONTINUE TO BE THE
DOMINANT PLAYER IN OUR WX THROUGH THE UPCOMING WEEKEND...EXTENDING
OUR STRETCH OF WELL ABOVE NORMAL TEMPS.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E
LAKES SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY
SUNDAY. ALTHOUGH LG SCALE FORCING AND ASSOC SFC LOW APPEAR FAIRLY
WEAK...ABUNDANT MOISTURE /+3-4 SD GEFS PWATS/ IMPLY CLOUDY/WET WX
LATE FRIDAY INTO EARLY SUNDAY. COLD AIR DAMMING SCENARIO SATURDAY
SHOULD RESULT IN A RELATIVE COOL DAY /COMPARED TO THOSE RECENTLY/
WITH READINGS STUCK IN THE 40S OVR THE CENTRAL MTNS. WARMER CONDS
EXPECTED SUNDAY...AS LOW LVL COOL AIR IS SCOURED AHEAD OF COLD
FRONT. GEFS 925 TEMPS AND EC MOS SUGGEST TEMPS COULD APPROACH 70F
ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS FOR A BRIEF PERIOD OF
DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE INDICATES N
STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC HIGH BUILDING SE
FROM ONTARIO. NEXT CHC OF PRECIP COMES MON NIGHT/TUESDAY...WHEN
ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA THRU THE GRT LKS.
HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND ASSOC SUPPLY OF
CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS FAVOR A WINTRY
MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN TUESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
VFR TO MVFR CIGS AND GENERALLY VFR VSBYS WILL CONTINUE ACROSS THE
REGION INTO THE LATE MORNING HOURS WITH SCATTERED SHOWERS RACING
NEWD AHEAD OF A WEAK COLD FRONT.
THE FRONT WILL CROSS THE WESTERN PENN AIRFIELDS LATE THIS
MORNING...AND THE SUSQ VALLEY TAF SITES EARLY THIS AFTERNOON.
LLWS WILL PERSIST FOR THE NEXT SVRL HOURS PRIOR TO THE ARRIVAL OF
THE COLD FRONT.
A BRIEF DROP TO THE IFR OR EVEN LIFR CIG IS EXPECTED IN THE 13-15Z
PERIOD INVOF KJST AS WINDS VEER TO THE SW THEN WSW...AND LIFT THE
MOIST AND SLIGHTLY COOLER AIR UP OVER THE LAUREL HIGHLANDS.
A FEW TO SVRL HOUR PERIOD OF GUSTY SW-WSW WINDS IS EXPECTED LATE
THIS MORNING AND THIS AFTERNOON...NEAR AND JUST IN THE WAKE OF THE
COLD FRONT.
EXPECT GRADUAL IMPROVEMENT DURING THE AFTERNOON HOURS WITH CLOUD
BASES LIFTING TO 5000 FT AGL OR HIGHER...AS WEAK HIGH PRESSURE
BUILDS TOWARD THE AREA.
OUTLOOK...
CHRISTMAS...NO SIG WX EXPECTED EARLY...MVFR CIGS WITH CHC R LATE
AFTERNOON AND AT NIGHT AS WARM FRONTAL FEATURE LIFTS BACK TO THE
NORTH.
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
&&
.CLIMATE...
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/CERU
AVIATION...LAMBERT/MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
605 AM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO PA
THROUGH THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR LOOP AT 10Z SHOWING A WEAKENING LINE OF CONVECTION MOVING
THROUGH CENTRAL PA ALONG AXIS OF LL JET. SFC ANALYSIS INDICATES
COLD FRONT IS LAGGING TO THE WEST ACROSS EASTERN OHIO. RADAR
TRENDS AND LATEST HRRR SUPPORT THE IDEA OF THIS BAND OF SCT
SHOWERS PROGRESSES EASTWARD ACROSS THE REGION THIS MORNING...EXITING
ALL BUT EXTREME SE PA BY MIDDAY.
ALTHOUGH NO LIGHTNING STRIKES NOTED AT 10Z...WILL CONTINUE TO
MENTION A SLIGHT CHC OF THUNDER COINCIDENT WITH FROPA LATE
AM/EARLY AFTN ACROSS THE SE COUNTIES...WHERE MDLS DEVELOP SOME
MODEST CAPES.
GUIDANCE STILL SUGGESTING CLEARING SKIES WILL OVERSPREAD MUCH OF
CENTRAL PA BY AFTN...AS SFC RIDGING AND LOWER PWAT AIR MASS
ARRIVES BEHIND COLD FRONT. CLOUDS AND THE LINGERING CHC OF A
SHOWER MAY PERSIST THRU EVENING ACROSS THE SOUTHEAST IN THE
VICINITY OF STALLED OUT FRONT.
THE BIGGEST STORY OF THIS CHRISTMAS EVE REMAINS THE RECORD
BREAKING TEMPS. RECORDS HAVE ALREADY FALLEN AT KBFD/KIPT/KMDT AND
ARE VERY LIKELY TO FALL AT KAOO/KUNV. SREF PLUMES INDICATE STEADY
OR SLOWLY FALLING TEMPS TODAY ACROSS THE NW MTNS...WHERE FROPA
WILL OCCUR EARLY IN THE DAY. HOWEVER...READINGS SHOULD RISE
SEVERAL DEGREES ELSEWHERE...WITH SUPERBLEND AND ECME MOS
SUPPORTING MAX TEMPS FROM ARND 60F ACROSS THE NW MTNS...TO ARND
70F OVR THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD PROVIDE
FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T RULE OUT A FEW EVENING SHOWERS ASSOC WITH WEAK
WAVE OF LOW PRES RIDING ALONG STALLED FRONTAL BNDRY. LIKEWISE...A
WEAK SHORTWAVE RIDING ACROSS THE GRT LKS COULD SUPPORT AN ISOLD
SHOWER TOWARD DAWN OVR THE NW MTNS.
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA COULD
SPREAD A BIT OF LGT RAIN INTO THE SOUTHERN PART OF THE STATE
DURING THE PM HOURS OF CHRISTMAS DAY. BLEND OF ENSEMBLE/OPER MDL
DATA SUPPORTS CHC POPS ACROSS THE SOUTHERN TIER AND SLGHT CHC OVR
THE NORTHERN HALF OF THE STATE. OTHERWISE...BIG STORY WILL
CONTINUE TO BE THE MILD WX. GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN
VERY WARM FOR DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE L50S
ACROSS THE NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
ANOMALOUS UPPER RIDGE OFF THE EAST COAST WILL CONTINUE TO BE THE
DOMINANT PLAYER IN OUR WX THROUGH THE UPCOMING WEEKEND...EXTENDING
OUR STRETCH OF WELL ABOVE NORMAL TEMPS.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E
LAKES SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY
SUNDAY. ALTHOUGH LG SCALE FORCING AND ASSOC SFC LOW APPEAR FAIRLY
WEAK...ABUNDANT MOISTURE /+3-4 SD GEFS PWATS/ IMPLY CLOUDY/WET WX
LATE FRIDAY INTO EARLY SUNDAY. COLD AIR DAMMING SCENARIO SATURDAY
SHOULD RESULT IN A RELATIVE COOL DAY /COMPARED TO THOSE RECENTLY/
WITH READINGS STUCK IN THE 40S OVR THE CENTRAL MTNS. WARMER CONDS
EXPECTED SUNDAY...AS LOW LVL COOL AIR IS SCOURED AHEAD OF COLD
FRONT. GEFS 925 TEMPS AND EC MOS SUGGEST TEMPS COULD APPROACH 70F
ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS FOR A BRIEF PERIOD OF
DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE INDICATES N
STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC HIGH BUILDING SE
FROM ONTARIO. NEXT CHC OF PRECIP COMES MON NIGHT/TUESDAY...WHEN
ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA THRU THE GRT LKS.
HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND ASSOC SUPPLY OF
CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS FAVOR A WINTRY
MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN TUESDAY.
&&
.AVIATION /10Z THURSDAY THROUGH MONDAY/...
FRAGMENTED REMNANTS OF THE WED EVENING SQUALL LINE ACROSS THE OHIO
VALLEY WAS MOVING OVER THE NW AND NORTH-CENTRAL MTNS OF PENN EARLY
TODAY AS A SFC TROUGH. THIS FEATURE WAS ACCOMPANIED BY AN AREA OF
MDT-HVY RAIN SHOWERS WITH A FEW EMBEDDED...FAST MOVING AND LOW-
TOPPED TSRA. BRIEF 25-30 KT WIND GUSTS FROM THE WEST OR NW ARE
POSSIBLE AT KUNV AND KIPT THROUGH 0830Z.
MAINLY MVFR CIGS AND VFR VSBYS WILL CONTINUE ACROSS THE SUSQ
VALLEY AND CENTRAL MTNS THIS MORNING...WHILE VFR TO MVFR WILL BE
FOUND OVER THE WESTERN TERMINALS KJST AND KBFD...WITH A LIKELY
DROP TO THE IFR OR EVEN LIFR CIG RANGE BY 12Z IN THE WAKE OF THE
AFOREMENTIONED SFC TROUGH AS WINDS BECOME SSWRLY THIS MORNING.
LOW LVL WIND SHEAR WILL OCCUR THROUGH AROUND 12Z OVER THE WESTERN
PENN AIRFIELDS...AND WILL CONTINUE UNTIL 14-16Z OVER THE CENTRAL
AND EASTERN PENN TAF SITES.
EXPECT SOME IMPROVEMENT DURING THE DAY TODAY...AS WEAK HIGH
PRESSURE BUILDS TOWARD THE AREA.
OUTLOOK...
CHRISTMAS...NO SIG WX EXPECTED EARLY...MVFR CIGS WITH CHC R LATE
AFTERNOON AND AT NIGHT AS WARM FRONTAL FEATURE LIFTS BACK TO THE
NORTH.
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
&&
.CLIMATE...
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/CERU
AVIATION...LAMBERT/MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
744 AM CST THU DEC 24 2015
.UPDATE...
QUICK UPDATE TO EXTEND DENSE FOG ADVISORY NORTHWARD PER LATEST
SATELLITE AND OBSERVATION TRENDS. A WARM FRONT IS QUICKLY LIFTING
NORTH ACROSS THE REGION THIS MORNING... STRETCHING FROM FROM
ROUGHLY NORTHERN AUSTIN COUNTY INTO POLK COUNTY JUDGING BY THE DEW
POINT INCREASES... AND VISIBILITIES HAVE IMPROVED GENERALLY INTO
THE 3 TO 5 MILE RANGE BEHIND THE FRONT. CANCELLED SOUTHERN PORTION
OF DENSE FOG ADVISORY IN RESPONSE. HRRR HAS DONE REMARKABLY WELL
CAPTURING TRENDS THIS MORNING AND EXPECT THE DENSE FOG THREAT TO
BE SHORT LIVED GIVEN THE PROGRESS OF THE FRONT AND TIME OF DAY.
UPDATED PRODUCTS ALREADY OUT.
HUFFMAN
&&
.PREV DISCUSSION... /ISSUED 518 AM CST THU DEC 24 2015/
AVIATION...
VISIBILITIES CONTINUE TO FLUCTUATE ACROSS SE TX EARLY THIS
MORNING. A SWATH OF CIRRUS MOVING ACROSS THE REGION LOOKS LIKE
IT IS THE MECHANISM CAUSING THE DISRUPTION TO TO CIGS/VSBY.
POTENTIAL STILL EXISTS THIS MORNING FOR CIGS/VSBY TO CRASH ONCE
THE CIRRUS EXITS THE AREA. HRRR DID A GOOD JOB YESTERDAY AND WILL
STAY WITH THIS SOLUTION FOR TODAY. THIS MEANS LOW CIGS FOR MUCH OF
THE DAY AND PERIODS OF DENSE FOG AT KGLS. NAM/GFS FCST SOUNDINGS
SHOW VFR CONDS AT KCLL TRANSITIONING TO MVFR CIGS BY AFTN...WITH
TAF SITES TO SOUTH GENERALLY MVFR FOR MOST OF THE DAY BEFORE
TRANSITIONING TO IFR/LIFR TONIGHT. ADDED -DZ OVERNIGHT AS FCST
SOUNDINGS LOOK SATURATED TO AROUND 900 MB WITH DRY AIR ABOVE THIS
LAYER. S-SE WINDS WILL BE ON THE LIGHT SIDE TODAY WITH SOME
STRENGTHENING ALONG THE COAST TONIGHT AND AREAWIDE ON FRIDAY. 43
PREV DISCUSSION... /ISSUED 508 AM CST THU DEC 24 2015/
SHORT TERM /CHRISTMAS EVE THROUGH CHRISTMAS/...
GENERALLY QUIET CONDITIONS UNDERWAY EARLY THIS CHRISTMAS EVE
MORNING... WITH THE MAIN WEATHER CONCERN PRESENTLY DENSE FOG
ACROSS PORTION OF THE REGION. INFRARED SATELLITE IMAGERY SHOWS
THIS FOG SLOWLY EXPANDING NORTHWARD FROM THE COAST... WITH
VISIBILITIES FALLING TO LESS THAN ONE MILE. HIGH RESOLUTION
GUIDANCE SHOWS FOG CONTINUING INTO THE MID MORNING HOURS AND
CONCERNED THAT THE ADVISORY MAY NEED TO BE EXTENDED WITH FORECAST
SOUNDINGS NOT SHOWING A STOUT INVERSION LIFTING UNTIL LATE
MORNING. FOR THE MORNING FORECAST... DID EXTEND THE ADVISORY
NORTHWARD TO ROUGHLY A COLUMBUS TO LIVINGSTON LINE BASED ON
SATELLITE TRENDS.
THE REMAINDER OF THE SHORT TERM WILL BE WARM... WITH INCREASING
RAIN CHANCES. ANOTHER A DRY MORNING WILL GIVE WAY TO ISOLATED
SHOWERS THIS AFTERNOON AS A WARM FRONT BEGINS TO LIFT INLAND AND
DEEPER MOISTURE RETURNS TO THE REGION /PRECIPITABLE WATER VALUES
RISING BACK OVER ONE INCH THIS AFTERNOON AND EVENING/. NEAR RECORD
HIGH TEMPERATURES WILL BE POSSIBLE AGAIN TODAY /HIGHS IN THE MID
70S TO NEAR 80/ BUT INCREASING CLOUD COVER IS EXPECTED TO KEEP
SITES A DEGREE OR TWO COOLER THAN YESTERDAY.
FOR TONIGHT... INCREASING DIVERGENCE IN THE SOUTHWEST FLOW ALOFT
WILL RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT LATE TONIGHT
INTO EARLY CHRISTMAS MORNING. THERE IS A MARGINAL RISK THAT SOME
OF THESE STORMS MAY BECOME STRONG TO SEVERE AND CAPABLE OF
DAMAGING WINDS OR LARGE HAIL /ROUGHLY ALONG AND EAST OF A
MADISONVILLE TO HOUSTON LINE/ WITH ENOUGH SHEAR TO PROMOTE STORM
ORGANIZATION /0-6 KM BULK SHEAR AROUND 30 TO 40 KNOTS/. HOWEVER...
OVERALL WEAK FORCING WILL DO A GOOD JOB LIMITING THUNDERSTORM
COVERAGE AND FOR NOW ONLY COVERING THE AREA WITH 30-40 POPS. FOG
DEVELOPMENT... SOME POSSIBLY DENSE... IS ALSO EXPECTED AGAIN
OVERNIGHT AS OVERNIGHT LOWS FALL INTO THE 60S TO NEAR 70.
FOR CHRISTMAS DAY... ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE UNDER MOSTLY CLOUDY SKIES AS
SEVERAL WEAK DISTURBANCES CROSS THE REGION. EXPECT HIGH
TEMPERATURES TO TOP OUT IN THE UPPER 70S.
HUFFMAN
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
BY FRIDAY NIGHT... A WAVE LOCATED JUST OFF THE PACIFIC NORTHWEST
COAST EARLY THIS MORNING ON WATER VAPOR IMAGERY WILL BEGIN
TRAVELING DOWN THE WEST COAST. THIS WAVE IS EXPECTED TO CUTOFF
OVER THE DESERT SOUTHWEST ON SATURDAY... AND 00Z GUIDANCE HAS COME
INTO BETTER AGREEMENT REGARDING THE TRAJECTORY OF THIS SYSTEM. THE
CANADIAN...GFS...AND EUROPEAN ALL SWING THE UPPER LOW ACROSS
SOUTHWEST TEXAS TO NORTHEAST TEXAS LATE SUNDAY AND CLEAR THE
STATE ON MONDAY.
WHAT HAPPENS DURING THIS TIME IS EXPECTED TO BE A VERY ACTIVE
WEATHER PERIOD FOR SOUTHEAST TEXAS... AND WELL... MOST OF THE
STATE FOR THAT MATTER. AS A LEAD SHORTWAVE EJECTS OUT OF THE
TROUGH OVER THE WESTERN CONUS ACROSS COLORADO ON FRIDAY... IT
WILL DISLODGE A MUCH COLDER AIRMASS... SENDING A COLD FRONT SURGING
INTO TEXAS ON SATURDAY. AT THE SAME TIME... HEIGHT FALLS AHEAD OF
THE UPPER LOW OVER THE SOUTHWEST /ROUGHLY 5 TO 7 DECAMETERS/ ARE
EXPECTED TO INDUCE A SURFACE LOW OVER NORTHERN MEXICO. INCREASING
FORCING AHEAD OF THE UPPER LOW IS EXPECTED TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS ON SATURDAY... SOME OF WHICH COULD BE
STRONG TO SEVERE OVER THE NORTHERN COUNTIES AS THEY DEVELOP ALONG
AN APPROACHING COLD FRONT LATE SATURDAY INTO EARLY SUNDAY. ON SUNDAY...
THE SURFACE LOW OVER MEXICO WILL BE DRAGGED NORTHEAST WITH THE
UPPER LOW WITH A LINE OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY
DEVELOPING ALONG AN ATTENDANT PACIFIC FRONT AND IMPACTING THE
REGION.
WHILE THIS EVENT IS STILL A FEW DAYS OUT... THIS PATTERN
CONTINUES TO REFLECT A SEVERE WEATHER THREAT AND HEAVY
RAIN/FLOODING THREAT FOR MUCH OF THE REGION. ALL SOUTHEAST TEXANS
ARE URGED TO CONTINUE MONITORING THE FORECAST... ESPECIALLY WITH
HOLIDAY TRAVEL POSSIBLE THIS WEEKEND.
DRIER CONDITIONS ARE EXPECTED TO SETTLE IN ACROSS THE REGION FROM
WEST TO EAST ON MONDAY AS THE SYSTEM CLEARS... WITH LITTLE TO NO
RAIN CHANCES EXPECTED THROUGH WEDNESDAY WITH VERY LITTLE MOISTURE
RECOVERY ANTICIPATED. MUCH COOLER AIR IN THE WAKE OF THE FRONT IS
EXPECTED TO DROP LOW TEMPERATURES INTO THE 30S FOR MUCH OF THE
REGION TUESDAY MORNING... WITH BELOW NORMAL TEMPERATURES
CONTINUING THROUGH THE END OF THE FORECAST.
HUFFMAN
MARINE...
AREAS OF FOG WILL CONTINUE TO AFFECT MARINE AREAS THROUGH THE DAY.
VSBY WILL VARY BETWEEN 1/2 AND 3 MILES AND DESPITE LIMITED IMPROVEMENT
IN VSBY TO ABOVE A MILE IN A FEW LOCATIONS PREFER TO MAINTAIN THE MARINE
DENSE FOG ADVISORY THROUGH 18Z. HRRR AND SREF ENSEMBLE GUIDANCE SUGGEST
DENSE FOG MAY LINGER NEAR THE COAST AND JUST OFFSHORE THROUGH CHRISTMAS
MORNING...AND PERHAPS LONGER.
LONG PERIOD SWELLS PROPAGATING INTO THE COASTAL WATERS WILL KEEP
SEAS SLIGHTLY ELEVATED AND WILL MAINTAIN THE SCA THROUGH 12Z FOR THE
20-60NM WATERS AND ISSUE AN SCEC FOR THE 0-20 NM THROUGH 12Z. WILL
CARRY CAUTION FLAGS FOR THE 20-60 NM WATERS FROM 12-18Z. LIGHTER
WINDS EXPECTED TODAY AND TONIGHT AS THE PRESSURE GRADIENT FLATTENS.
THE GRADIENT TIGHTENS AGAIN THIS EVENING AND ONSHORE WINDS WILL ONCE
AGAIN STRENGTHEN. ANOTHER SCEC WILL BE REQUIRED FOR THE OFFSHORE
WATERS TONIGHT. WINDS STRENGTHEN TO 20-25 KTS ON SATURDAY AS LOW
PRESSURE DEVELOPS IN WEST TEXAS. AN SCA WILL LIKELY BE REQUIRED
THROUGH SUNDAY AS THE LOW OVER WEST TEXAS SHIFTS SLOWLY EAST. A COLD
FRONT WILL CROSS THE COASTAL WATERS SUNDAY NIGHT WITH A LINE OF
STRONG STORMS AND A WIND SHIFT TO THE W-NW. ANOTHER SCA WILL BE
REQUIRED IN THE WAKE OF THE FRONT. WINDS WILL GENTLY VEER TO THE
NE-E BY TUESDAY AND DECREASE IN SPEED AS HIGH PRESSURE BUILDS TOWARD
THE NORTHERN GULF COAST.
TIDE LEVELS REMAIN AROUND A FOOT OR SO ABOVE NORMAL AND WITH A
CONTINUED STRONG ONSHORE FLOW...TIDE LEVELS SHOULD REMAIN ELEVATED
THROUGH THE WEEKEND. ATTM...COASTAL FLOODING IS NOT ANTICIPATED AS
HIGH TIDES ARE EXPECTED TO REMAIN 3.0 FEET OR LESS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 65 77 70 78 / 10 30 40 50 50
HOUSTON (IAH) 79 68 79 70 77 / 20 40 40 40 50
GALVESTON (GLS) 74 67 73 68 73 / 20 30 40 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
ZONES: BRAZOS...BURLESON...GRIMES...HOUSTON...MADISON...
POLK...SAN JACINTO...TRINITY...WALKER...WASHINGTON.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...14
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
531 AM CST THU DEC 24 2015
.AVIATION...
A WEAK COLD FRONT PASSING THROUGH THE CENTRAL PANHANDLE WILL PASS
TAF SITES BY MID MORNING WITH MODEST NORTH TO NORTHEAST POST
FRONTAL BREEZES. WINDS MAY BRIEFLY EXCEED 12 KNOTS...ESPECIALLY AT
KCDS. WINDS WILL TURN TO SOUTHEAST LATER TODAY AT BOTH KLBB AND
KPVW. OTHERWISE VFR WITH AN INCREASE IN MID LEVEL MOISTURE
EXPECTED MAINLY OVER KPVW LATER TODAY. LIGHT SHOWER CHANCES SHOULD
REMAIN NORTHWEST OF KPVW. RMCQUEEN
&&
.PREV DISCUSSION... /ISSUED 456 AM CST THU DEC 24 2015/
SHORT TERM...
A WEAK COLD FRONT EXTENDING OUT OF THE DISTURBANCE IN EASTERN SOUTH
DAKOTA AND NEBRASKA...AND CROSSING THE PANHANDLE AT THIS TIME...WILL
SPREAD SOUTH ACROSS THE AREA SHORTLY AFTER DAYBREAK. NORTHERLY
BREEZES WILL BE STRONGEST OVER THE NORTHERN ROLLING PLAINS...NEAR 15
MPH LATE THIS MORNING...TRENDING LIGHTER LATER TODAY AND TURNING
SOUTHEAST ON THE CAPROCK. DRIER AIR ALSO WILL SPREAD SOUTH BEHIND
THE FRONT. ALOFT...A VERY ENERGETIC WESTERLY FLOW WILL BACK TO THE
SOUTHWEST AS POTENT STORM ENERGY CROSSES THE NORTHWEST COAST AND
STARTS DEEPENING OVER THE NORTHERN GREAT BASIN TONIGHT. BANDS OF MID
AND UPPER LEVEL MOISTURE WILL CONTINUE OVER OUR AREA TODAY AND
TONIGHT. HRRR SOLUTION AT LEAST TRIES TO BREAK OUT SPRITZY LIGHT
SHOWERS NEAR NORTHWESTERN ZONES LATER TODAY...CHANCES WILL BE SMALL
HOWEVER OWING TO THE DRIER LOWER LEVELS BEHIND THE FRONT MENTIONED
ABOVE. SLIGHTLY COOLER WITH THE FRONT TODAY AND SOME THICKENING OF
MID LEVEL CLOUDS EXPECTED DURING THE DAY...BUT STILL ABOVE NORMAL.
SLIGHTLY COOLER TONIGHT AS WELL YET ALSO STILL ABOVE NORMAL.
RMCQUEEN
LONG TERM...
LIKELIHOOD OF BLIZZARD CONDITIONS AND HEAVY SNOW CONTINUING FOR
LATE WEEKEND...
AFTER ONE MORE ABNORMALLY WARM DECEMBER DAY TO CELEBRATE
CHRISTMAS...INCREASING SOUTHWEST FLOW ALOFT BRINGING THIS WARMUP
WILL BE STERNLY UNDERCUT BY A STRONG COLD FRONT BLASTING SOUTH
ACROSS THE FRONT RANGE AND GREAT PLAINS. GIVEN THE MAGNITUDE OF THE
COLD AIR AHEAD OF A 1040 MB SURFACE RIDGE...WILL IN ALL LIKELIHOOD
SEE THIS BOUNDARY ARRIVE ACROSS THE FAR SOUTHERN TEXAS PANHANDLE BY
DAYBREAK SATURDAY WITH NORTH WINDS QUICKLY ACCELERATING TO 15-25
MPH AFTER SUNRISE. FALLING TEMPERATURES WILL RESULT THROUGHOUT THE
DAY VIA POTENT COLD AIR ADVECTION...WITH READINGS APPROACHING
FREEZING IN THE NORTHWEST BY LATE AFTERNOON. THE WESTERN EXTENT OF
SOME ENHANCED GULF MOISTURE MAY BE ABLE TO HOLD FIRM ACROSS THE
ROLLING PLAINS...SO HAVE THUS MAINTAINED SHOWER MENTION ALONG WITH
A SLIM CHANCE OF A THUNDERSTORM BEFORE THE COLD AIR POURS
IN...ALTHOUGH MAY BE ABLE TO EVENTUALLY PULL THUNDER PENDING THE
SPEED OF THE FRONT.
UPPER LOW DIGGING THROUGH ARIZONA WILL SLOWLY TRAVERSE EASTWARD WITH
DEEP LAYER LIFT INCREASING ACROSS THE WESTERN SOUTH PLAINS HEADING
INTO SATURDAY EVENING. TRENDS CONTINUE FOR THIS SYSTEM TO SLOW AS
IT PUSHES EASTWARD...WHICH IS TYPICAL OF A STORM OF THIS CALIBER.
PRECIPITATION SHOULD BEGIN TO FALL ACROSS THE SOUTH PLAINS AND FAR
SOUTHWEST PANHANDLE AS THE UPPER LEVEL AND ISENTROPIC LIFT
INCREASE SATURDAY EVENING...SPREADING EAST INTO THE OVERNIGHT
HOURS. SNOW LOOKS TO BE THE DOMINANT MODE ACROSS THE TYPICAL
SNOWBELT AT THE ONSET...WHILE A MIX WILL BE FOUND FARTHER SOUTH
AND EAST INITIALLY. RAPID DYNAMIC COOLING COMBINED WITH WET
BULBING SHOULD MEAN MORE SLEET AS OPPOSED TO FREEZING RAIN DURING
THE MIXED PHASE STAGE SATURDAY EVENING/NIGHT...WITH SNOW TAKING
OVER BY DAYBREAK SUNDAY. INSTABILITY AND SATURATION IN THE
DENDRITIC GROWTH LAYER CONTINUE TO LOOK FAVORABLE FOR THE THREAT
OF HEAVY SNOW...WITH AMOUNTS OF AT LEAST 4 INCHES LOOKING LIKE A
GOOD BET. WILL HOLD OFF ON WATCH ISSUANCE FOR ANOTHER PERIOD OR
TWO TO BETTER PINPOINT TIMING AND TRACK OF THE SYSTEM.
THE MAJORITY OF THE SNOW THAT FALLS WILL BE OF THE BLOWING/DRIFTING
VARIETY GIVEN THE PROLONGED PERIOD OF BRISK NORTHERLY WINDS EXPECTED
ON THE NORTH/NORTHWEST QUADRANT OF THE PARENT UPPER LOW. WHILE
TRAVEL IS HIGHLY DISCOURAGED SATURDAY NIGHT THROUGH AT LEAST EARLY
MONDAY...THOSE TRAVELING ON EAST-WEST ORIENTED HIGHWAYS WILL BE AT
GREATER RISK GIVEN THE PERPENDICULAR COMPONENT OF THE WINDS ALLOWING
FOR SNOW TO COVER ROADWAYS.
WIND CHILLS...INCLUDING SINGLE DIGIT AND BELOW ZERO READINGS...WILL
BE ANOTHER ISSUE OF CONCERN WITH TEMPERATURES REMAINING BELOW
FREEZING FROM LATE SATURDAY UNTIL LIKELY TUESDAY AFTERNOON. WIND
SPEEDS OF 25-35 MPH WILL PERSIST FROM SATURDAY NIGHT THROUGH
SUNDAY...WHILE STILL REMAINING ABOVE 20 MPH INTO MONDAY.
SPEED/TRACK OF THE UPPER LOW WILL DETERMINE HOW LONG SNOW PERSISTS INTO
MONDAY...BUT NONETHELESS SHOULD SEE THE SNOW AND WIND TAPER OFF
DURING THE DAY. HOWEVER...TRAVEL WILL STILL BE TREACHEROUS GIVEN
EXPECTED TEMPERATURES BELOW FREEZING AND SUBSEQUENT LACK OF
SNOWMELT. A SERIES OF DISTURBANCES THROUGH NEXT WEEK WILL LEAD TO
A COOL END TO THE YEAR...INCLUDING CRISP NIGHTS WHERE SNOWPACK
REMAINS IN PLACE. TRACK OF THESE SYSTEMS CURRENTLY APPEAR TOO FAR
NORTH TO WARRANT PRECIPITATION MENTION.
AS I SIGN OFF THIS MORNING...I WOULD LIKE TO LET EVERYONE KNOW WHAT
A PLEASURE IT HAS BEEN SERVING THE FOLKS OF THE SOUTH PLAINS REGION.
THANK YOU FOR MAKING MY TIME SPENT IN WEST TEXAS MEMORABLE AND
ENJOYABLE...AND I VERY MUCH LOOK FORWARD TO FUTURE RETURN VISITS. I
WISH ALL OF YOU A VERY MERRY CHRISTMAS AND A HAPPY NEW YEAR!
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99/05
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
518 AM CST THU DEC 24 2015
.AVIATION...
VISIBILITIES CONTINUE TO FLUCTUATE ACROSS SE TX EARLY THIS
MORNING. A SWATH OF CIRRUS MOVING ACROSS THE REGION LOOKS LIKE
IT IS THE MECHANISM CAUSING THE DISRUPTION TO TO CIGS/VSBY.
POTENTIAL STILL EXISTS THIS MORNING FOR CIGS/VSBY TO CRASH ONCE
THE CIRRUS EXITS THE AREA. HRRR DID A GOOD JOB YESTERDAY AND WILL
STAY WITH THIS SOLUTION FOR TODAY. THIS MEANS LOW CIGS FOR MUCH OF
THE DAY AND PERIODS OF DENSE FOG AT KGLS. NAM/GFS FCST SOUNDINGS
SHOW VFR CONDS AT KCLL TRANSITIONING TO MVFR CIGS BY AFTN...WITH
TAF SITES TO SOUTH GENERALLY MVFR FOR MOST OF THE DAY BEFORE
TRANSITIONING TO IFR/LIFR TONIGHT. ADDED -DZ OVERNIGHT AS FCST
SOUNDINGS LOOK SATURATED TO AROUND 900 MB WITH DRY AIR ABOVE THIS
LAYER. S-SE WINDS WILL BE ON THE LIGHT SIDE TODAY WITH SOME
STRENGTHENING ALONG THE COAST TONIGHT AND AREAWIDE ON FRIDAY. 43
&&
.PREV DISCUSSION... /ISSUED 508 AM CST THU DEC 24 2015/
SHORT TERM /CHRISTMAS EVE THROUGH CHRISTMAS/...
GENERALLY QUIET CONDITIONS UNDERWAY EARLY THIS CHRISTMAS EVE
MORNING... WITH THE MAIN WEATHER CONCERN PRESENTLY DENSE FOG
ACROSS PORTION OF THE REGION. INFRARED SATELLITE IMAGERY SHOWS
THIS FOG SLOWLY EXPANDING NORTHWARD FROM THE COAST... WITH
VISIBILITIES FALLING TO LESS THAN ONE MILE. HIGH RESOLUTION
GUIDANCE SHOWS FOG CONTINUING INTO THE MID MORNING HOURS AND
CONCERNED THAT THE ADVISORY MAY NEED TO BE EXTENDED WITH FORECAST
SOUNDINGS NOT SHOWING A STOUT INVERSION LIFTING UNTIL LATE
MORNING. FOR THE MORNING FORECAST... DID EXTEND THE ADVISORY
NORTHWARD TO ROUGHLY A COLUMBUS TO LIVINGSTON LINE BASED ON
SATELLITE TRENDS.
THE REMAINDER OF THE SHORT TERM WILL BE WARM... WITH INCREASING
RAIN CHANCES. ANOTHER A DRY MORNING WILL GIVE WAY TO ISOLATED
SHOWERS THIS AFTERNOON AS A WARM FRONT BEGINS TO LIFT INLAND AND
DEEPER MOISTURE RETURNS TO THE REGION /PRECIPITABLE WATER VALUES
RISING BACK OVER ONE INCH THIS AFTERNOON AND EVENING/. NEAR RECORD
HIGH TEMPERATURES WILL BE POSSIBLE AGAIN TODAY /HIGHS IN THE MID
70S TO NEAR 80/ BUT INCREASING CLOUD COVER IS EXPECTED TO KEEP
SITES A DEGREE OR TWO COOLER THAN YESTERDAY.
FOR TONIGHT... INCREASING DIVERGENCE IN THE SOUTHWEST FLOW ALOFT
WILL RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT LATE TONIGHT
INTO EARLY CHRISTMAS MORNING. THERE IS A MARGINAL RISK THAT SOME
OF THESE STORMS MAY BECOME STRONG TO SEVERE AND CAPABLE OF
DAMAGING WINDS OR LARGE HAIL /ROUGHLY ALONG AND EAST OF A
MADISONVILLE TO HOUSTON LINE/ WITH ENOUGH SHEAR TO PROMOTE STORM
ORGANIZATION /0-6 KM BULK SHEAR AROUND 30 TO 40 KNOTS/. HOWEVER...
OVERALL WEAK FORCING WILL DO A GOOD JOB LIMITING THUNDERSTORM
COVERAGE AND FOR NOW ONLY COVERING THE AREA WITH 30-40 POPS. FOG
DEVELOPMENT... SOME POSSIBLY DENSE... IS ALSO EXPECTED AGAIN
OVERNIGHT AS OVERNIGHT LOWS FALL INTO THE 60S TO NEAR 70.
FOR CHRISTMAS DAY... ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE UNDER MOSTLY CLOUDY SKIES AS
SEVERAL WEAK DISTURBANCES CROSS THE REGION. EXPECT HIGH
TEMPERATURES TO TOP OUT IN THE UPPER 70S.
HUFFMAN
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
BY FRIDAY NIGHT... A WAVE LOCATED JUST OFF THE PACIFIC NORTHWEST
COAST EARLY THIS MORNING ON WATER VAPOR IMAGERY WILL BEGIN
TRAVELING DOWN THE WEST COAST. THIS WAVE IS EXPECTED TO CUTOFF
OVER THE DESERT SOUTHWEST ON SATURDAY... AND 00Z GUIDANCE HAS COME
INTO BETTER AGREEMENT REGARDING THE TRAJECTORY OF THIS SYSTEM. THE
CANADIAN...GFS...AND EUROPEAN ALL SWING THE UPPER LOW ACROSS
SOUTHWEST TEXAS TO NORTHEAST TEXAS LATE SUNDAY AND CLEAR THE
STATE ON MONDAY.
WHAT HAPPENS DURING THIS TIME IS EXPECTED TO BE A VERY ACTIVE
WEATHER PERIOD FOR SOUTHEAST TEXAS... AND WELL... MOST OF THE
STATE FOR THAT MATTER. AS A LEAD SHORTWAVE EJECTS OUT OF THE
TROUGH OVER THE WESTERN CONUS ACROSS COLORADO ON FRIDAY... IT
WILL DISLODGE A MUCH COLDER AIRMASS... SENDING A COLD FRONT SURGING
INTO TEXAS ON SATURDAY. AT THE SAME TIME... HEIGHT FALLS AHEAD OF
THE UPPER LOW OVER THE SOUTHWEST /ROUGHLY 5 TO 7 DECAMETERS/ ARE
EXPECTED TO INDUCE A SURFACE LOW OVER NORTHERN MEXICO. INCREASING
FORCING AHEAD OF THE UPPER LOW IS EXPECTED TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS ON SATURDAY... SOME OF WHICH COULD BE
STRONG TO SEVERE OVER THE NORTHERN COUNTIES AS THEY DEVELOP ALONG
AN APPROACHING COLD FRONT LATE SATURDAY INTO EARLY SUNDAY. ON SUNDAY...
THE SURFACE LOW OVER MEXICO WILL BE DRAGGED NORTHEAST WITH THE
UPPER LOW WITH A LINE OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY
DEVELOPING ALONG AN ATTENDANT PACIFIC FRONT AND IMPACTING THE
REGION.
WHILE THIS EVENT IS STILL A FEW DAYS OUT... THIS PATTERN
CONTINUES TO REFLECT A SEVERE WEATHER THREAT AND HEAVY
RAIN/FLOODING THREAT FOR MUCH OF THE REGION. ALL SOUTHEAST TEXANS
ARE URGED TO CONTINUE MONITORING THE FORECAST... ESPECIALLY WITH
HOLIDAY TRAVEL POSSIBLE THIS WEEKEND.
DRIER CONDITIONS ARE EXPECTED TO SETTLE IN ACROSS THE REGION FROM
WEST TO EAST ON MONDAY AS THE SYSTEM CLEARS... WITH LITTLE TO NO
RAIN CHANCES EXPECTED THROUGH WEDNESDAY WITH VERY LITTLE MOISTURE
RECOVERY ANTICIPATED. MUCH COOLER AIR IN THE WAKE OF THE FRONT IS
EXPECTED TO DROP LOW TEMPERATURES INTO THE 30S FOR MUCH OF THE
REGION TUESDAY MORNING... WITH BELOW NORMAL TEMPERATURES
CONTINUING THROUGH THE END OF THE FORECAST.
HUFFMAN
MARINE...
AREAS OF FOG WILL CONTINUE TO AFFECT MARINE AREAS THROUGH THE DAY.
VSBY WILL VARY BETWEEN 1/2 AND 3 MILES AND DESPITE LIMITED IMPROVEMENT
IN VSBY TO ABOVE A MILE IN A FEW LOCATIONS PREFER TO MAINTAIN THE MARINE
DENSE FOG ADVISORY THROUGH 18Z. HRRR AND SREF ENSEMBLE GUIDANCE SUGGEST
DENSE FOG MAY LINGER NEAR THE COAST AND JUST OFFSHORE THROUGH CHRISTMAS
MORNING...AND PERHAPS LONGER.
LONG PERIOD SWELLS PROPAGATING INTO THE COASTAL WATERS WILL KEEP
SEAS SLIGHTLY ELEVATED AND WILL MAINTAIN THE SCA THROUGH 12Z FOR THE
20-60NM WATERS AND ISSUE AN SCEC FOR THE 0-20 NM THROUGH 12Z. WILL
CARRY CAUTION FLAGS FOR THE 20-60 NM WATERS FROM 12-18Z. LIGHTER
WINDS EXPECTED TODAY AND TONIGHT AS THE PRESSURE GRADIENT FLATTENS.
THE GRADIENT TIGHTENS AGAIN THIS EVENING AND ONSHORE WINDS WILL ONCE
AGAIN STRENGTHEN. ANOTHER SCEC WILL BE REQUIRED FOR THE OFFSHORE
WATERS TONIGHT. WINDS STRENGTHEN TO 20-25 KTS ON SATURDAY AS LOW
PRESSURE DEVELOPS IN WEST TEXAS. AN SCA WILL LIKELY BE REQUIRED
THROUGH SUNDAY AS THE LOW OVER WEST TEXAS SHIFTS SLOWLY EAST. A COLD
FRONT WILL CROSS THE COASTAL WATERS SUNDAY NIGHT WITH A LINE OF
STRONG STORMS AND A WIND SHIFT TO THE W-NW. ANOTHER SCA WILL BE
REQUIRED IN THE WAKE OF THE FRONT. WINDS WILL GENTLY VEER TO THE
NE-E BY TUESDAY AND DECREASE IN SPEED AS HIGH PRESSURE BUILDS TOWARD
THE NORTHERN GULF COAST.
TIDE LEVELS REMAIN AROUND A FOOT OR SO ABOVE NORMAL AND WITH A
CONTINUED STRONG ONSHORE FLOW...TIDE LEVELS SHOULD REMAIN ELEVATED
THROUGH THE WEEKEND. ATTM...COASTAL FLOODING IS NOT ANTICIPATED AS
HIGH TIDES ARE EXPECTED TO REMAIN 3.0 FEET OR LESS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 65 77 70 78 / 10 30 40 50 50
HOUSTON (IAH) 79 68 79 70 77 / 20 40 40 40 50
GALVESTON (GLS) 74 67 73 68 73 / 20 30 40 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...CHAMBERS...COLORADO...FORT
BEND...GALVESTON...HARRIS...JACKSON...LIBERTY...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...WALLER...WHARTON.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST EARLY THIS
MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
508 AM CST THU DEC 24 2015
.SHORT TERM /CHRISTMAS EVE THROUGH CHRISTMAS/...
GENERALLY QUIET CONDITIONS UNDERWAY EARLY THIS CHRISTMAS EVE
MORNING... WITH THE MAIN WEATHER CONCERN PRESENTLY DENSE FOG
ACROSS PORTION OF THE REGION. INFRARED SATELLITE IMAGERY SHOWS
THIS FOG SLOWLY EXPANDING NORTHWARD FROM THE COAST... WITH
VISIBILITIES FALLING TO LESS THAN ONE MILE. HIGH RESOLUTION
GUIDANCE SHOWS FOG CONTINUING INTO THE MID MORNING HOURS AND
CONCERNED THAT THE ADVISORY MAY NEED TO BE EXTENDED WITH FORECAST
SOUNDINGS NOT SHOWING A STOUT INVERSION LIFTING UNTIL LATE
MORNING. FOR THE MORNING FORECAST... DID EXTEND THE ADVISORY
NORTHWARD TO ROUGHLY A COLUMBUS TO LIVINGSTON LINE BASED ON
SATELLITE TRENDS.
THE REMAINDER OF THE SHORT TERM WILL BE WARM... WITH INCREASING
RAIN CHANCES. ANOTHER A DRY MORNING WILL GIVE WAY TO ISOLATED
SHOWERS THIS AFTERNOON AS A WARM FRONT BEGINS TO LIFT INLAND AND
DEEPER MOISTURE RETURNS TO THE REGION /PRECIPITABLE WATER VALUES
RISING BACK OVER ONE INCH THIS AFTERNOON AND EVENING/. NEAR RECORD
HIGH TEMPERATURES WILL BE POSSIBLE AGAIN TODAY /HIGHS IN THE MID
70S TO NEAR 80/ BUT INCREASING CLOUD COVER IS EXPECTED TO KEEP
SITES A DEGREE OR TWO COOLER THAN YESTERDAY.
FOR TONIGHT... INCREASING DIVERGENCE IN THE SOUTHWEST FLOW ALOFT
WILL RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT LATE TONIGHT
INTO EARLY CHRISTMAS MORNING. THERE IS A MARGINAL RISK THAT SOME
OF THESE STORMS MAY BECOME STRONG TO SEVERE AND CAPABLE OF
DAMAGING WINDS OR LARGE HAIL /ROUGHLY ALONG AND EAST OF A
MADISONVILLE TO HOUSTON LINE/ WITH ENOUGH SHEAR TO PROMOTE STORM
ORGANIZATION /0-6 KM BULK SHEAR AROUND 30 TO 40 KNOTS/. HOWEVER...
OVERALL WEAK FORCING WILL DO A GOOD JOB LIMITING THUNDERSTORM
COVERAGE AND FOR NOW ONLY COVERING THE AREA WITH 30-40 POPS. FOG
DEVELOPMENT... SOME POSSIBLY DENSE... IS ALSO EXPECTED AGAIN
OVERNIGHT AS OVERNIGHT LOWS FALL INTO THE 60S TO NEAR 70.
FOR CHRISTMAS DAY... ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE UNDER MOSTLY CLOUDY SKIES AS
SEVERAL WEAK DISTURBANCES CROSS THE REGION. EXPECT HIGH
TEMPERATURES TO TOP OUT IN THE UPPER 70S.
HUFFMAN
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
BY FRIDAY NIGHT... A WAVE LOCATED JUST OFF THE PACIFIC NORTHWEST
COAST EARLY THIS MORNING ON WATER VAPOR IMAGERY WILL BEGIN
TRAVELING DOWN THE WEST COAST. THIS WAVE IS EXPECTED TO CUTOFF
OVER THE DESERT SOUTHWEST ON SATURDAY... AND 00Z GUIDANCE HAS COME
INTO BETTER AGREEMENT REGARDING THE TRAJECTORY OF THIS SYSTEM. THE
CANADIAN...GFS...AND EUROPEAN ALL SWING THE UPPER LOW ACROSS
SOUTHWEST TEXAS TO NORTHEAST TEXAS LATE SUNDAY AND CLEAR THE
STATE ON MONDAY.
WHAT HAPPENS DURING THIS TIME IS EXPECTED TO BE A VERY ACTIVE
WEATHER PERIOD FOR SOUTHEAST TEXAS... AND WELL... MOST OF THE
STATE FOR THAT MATTER. AS A LEAD SHORTWAVE EJECTS OUT OF THE
TROUGH OVER THE WESTERN CONUS ACROSS COLORADO ON FRIDAY... IT
WILL DISLODGE A MUCH COLDER AIRMASS... SENDING A COLD FRONT SURGING
INTO TEXAS ON SATURDAY. AT THE SAME TIME... HEIGHT FALLS AHEAD OF
THE UPPER LOW OVER THE SOUTHWEST /ROUGHLY 5 TO 7 DECAMETERS/ ARE
EXPECTED TO INDUCE A SURFACE LOW OVER NORTHERN MEXICO. INCREASING
FORCING AHEAD OF THE UPPER LOW IS EXPECTED TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS ON SATURDAY... SOME OF WHICH COULD BE
STRONG TO SEVERE OVER THE NORTHERN COUNTIES AS THEY DEVELOP ALONG
AN APPROACHING COLD FRONT LATE SATURDAY INTO EARLY SUNDAY. ON SUNDAY...
THE SURFACE LOW OVER MEXICO WILL BE DRAGGED NORTHEAST WITH THE
UPPER LOW WITH A LINE OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY
DEVELOPING ALONG AN ATTENDANT PACIFIC FRONT AND IMPACTING THE
REGION.
WHILE THIS EVENT IS STILL A FEW DAYS OUT... THIS PATTERN
CONTINUES TO REFLECT A SEVERE WEATHER THREAT AND HEAVY
RAIN/FLOODING THREAT FOR MUCH OF THE REGION. ALL SOUTHEAST TEXANS
ARE URGED TO CONTINUE MONITORING THE FORECAST... ESPECIALLY WITH
HOLIDAY TRAVEL POSSIBLE THIS WEEKEND.
DRIER CONDITIONS ARE EXPECTED TO SETTLE IN ACROSS THE REGION FROM
WEST TO EAST ON MONDAY AS THE SYSTEM CLEARS... WITH LITTLE TO NO
RAIN CHANCES EXPECTED THROUGH WEDNESDAY WITH VERY LITTLE MOISTURE
RECOVERY ANTICIPATED. MUCH COOLER AIR IN THE WAKE OF THE FRONT IS
EXPECTED TO DROP LOW TEMPERATURES INTO THE 30S FOR MUCH OF THE
REGION TUESDAY MORNING... WITH BELOW NORMAL TEMPERATURES
CONTINUING THROUGH THE END OF THE FORECAST.
HUFFMAN
&&
.MARINE...
AREAS OF FOG WILL CONTINUE TO AFFECT MARINE AREAS THROUGH THE DAY.
VSBY WILL VARY BETWEEN 1/2 AND 3 MILES AND DESPITE LIMITED IMPROVEMENT
IN VSBY TO ABOVE A MILE IN A FEW LOCATIONS PREFER TO MAINTAIN THE MARINE
DENSE FOG ADVISORY THROUGH 18Z. HRRR AND SREF ENSEMBLE GUIDANCE SUGGEST
DENSE FOG MAY LINGER NEAR THE COAST AND JUST OFFSHORE THROUGH CHRISTMAS
MORNING...AND PERHAPS LONGER.
LONG PERIOD SWELLS PROPAGATING INTO THE COASTAL WATERS WILL KEEP
SEAS SLIGHTLY ELEVATED AND WILL MAINTAIN THE SCA THROUGH 12Z FOR THE
20-60NM WATERS AND ISSUE AN SCEC FOR THE 0-20 NM THROUGH 12Z. WILL
CARRY CAUTION FLAGS FOR THE 20-60 NM WATERS FROM 12-18Z. LIGHTER
WINDS EXPECTED TODAY AND TONIGHT AS THE PRESSURE GRADIENT FLATTENS.
THE GRADIENT TIGHTENS AGAIN THIS EVENING AND ONSHORE WINDS WILL ONCE
AGAIN STRENGTHEN. ANOTHER SCEC WILL BE REQUIRED FOR THE OFFSHORE
WATERS TONIGHT. WINDS STRENGTHEN TO 20-25 KTS ON SATURDAY AS LOW
PRESSURE DEVELOPS IN WEST TEXAS. AN SCA WILL LIKELY BE REQUIRED
THROUGH SUNDAY AS THE LOW OVER WEST TEXAS SHIFTS SLOWLY EAST. A COLD
FRONT WILL CROSS THE COASTAL WATERS SUNDAY NIGHT WITH A LINE OF
STRONG STORMS AND A WIND SHIFT TO THE W-NW. ANOTHER SCA WILL BE
REQUIRED IN THE WAKE OF THE FRONT. WINDS WILL GENTLY VEER TO THE
NE-E BY TUESDAY AND DECREASE IN SPEED AS HIGH PRESSURE BUILDS TOWARD
THE NORTHERN GULF COAST.
TIDE LEVELS REMAIN AROUND A FOOT OR SO ABOVE NORMAL AND WITH A
CONTINUED STRONG ONSHORE FLOW...TIDE LEVELS SHOULD REMAIN ELEVATED
THROUGH THE WEEKEND. ATTM...COASTAL FLOODING IS NOT ANTICIPATED AS
HIGH TIDES ARE EXPECTED TO REMAIN 3.0 FEET OR LESS. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 65 77 70 78 / 10 30 40 50 50
HOUSTON (IAH) 79 68 79 70 77 / 20 40 40 40 50
GALVESTON (GLS) 74 67 73 68 73 / 20 30 40 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...CHAMBERS...COLORADO...FORT
BEND...GALVESTON...HARRIS...JACKSON...LIBERTY...MATAGORDA...
MONTGOMERY...POLK...SAN JACINTO...WALLER...WHARTON.
GM...DENSE FOG ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING ZONES:
GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH ISLAND
TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 AM CST EARLY THIS
MORNING FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO
THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 6 AM CST EARLY THIS MORNING FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL NOON CST TODAY FOR THE
FOLLOWING ZONES: WATERS FROM FREEPORT TO THE MATAGORDA SHIP
CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH ISLAND TO
FREEPORT 20 TO 60 NM.
&&
$$
DISCUSSION...14
AVIATION/MARINE...43
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
456 AM CST THU DEC 24 2015
.SHORT TERM...
A WEAK COLD FRONT EXTENDING OUT OF THE DISTURBANCE IN EASTERN SOUTH
DAKOTA AND NEBRASKA...AND CROSSING THE PANHANDLE AT THIS TIME...WILL
SPREAD SOUTH ACROSS THE AREA SHORTLY AFTER DAYBREAK. NORTHERLY
BREEZES WILL BE STRONGEST OVER THE NORTHERN ROLLING PLAINS...NEAR 15
MPH LATE THIS MORNING...TRENDING LIGHTER LATER TODAY AND TURNING
SOUTHEAST ON THE CAPROCK. DRIER AIR ALSO WILL SPREAD SOUTH BEHIND
THE FRONT. ALOFT...A VERY ENERGETIC WESTERLY FLOW WILL BACK TO THE
SOUTHWEST AS POTENT STORM ENERGY CROSSES THE NORTHWEST COAST AND
STARTS DEEPENING OVER THE NORTHERN GREAT BASIN TONIGHT. BANDS OF MID
AND UPPER LEVEL MOISTURE WILL CONTINUE OVER OUR AREA TODAY AND
TONIGHT. HRRR SOLUTION AT LEAST TRIES TO BREAK OUT SPRITZY LIGHT
SHOWERS NEAR NORTHWESTERN ZONES LATER TODAY...CHANCES WILL BE SMALL
HOWEVER OWING TO THE DRIER LOWER LEVELS BEHIND THE FRONT MENTIONED
ABOVE. SLIGHTLY COOLER WITH THE FRONT TODAY AND SOME THICKENING OF
MID LEVEL CLOUDS EXPECTED DURING THE DAY...BUT STILL ABOVE NORMAL.
SLIGHTLY COOLER TONIGHT AS WELL YET ALSO STILL ABOVE NORMAL.
RMCQUEEN
.LONG TERM...
.LIKELIHOOD OF BLIZZARD CONDITIONS AND HEAVY SNOW CONTINUING FOR
LATE WEEKEND...
AFTER ONE MORE ABNORMALLY WARM DECEMBER DAY TO CELEBRATE
CHRISTMAS...INCREASING SOUTHWEST FLOW ALOFT BRINGING THIS WARMUP
WILL BE STERNLY UNDERCUT BY A STRONG COLD FRONT BLASTING SOUTH
ACROSS THE FRONT RANGE AND GREAT PLAINS. GIVEN THE MAGNITUDE OF THE
COLD AIR AHEAD OF A 1040 MB SURFACE RIDGE...WILL IN ALL LIKELIHOOD
SEE THIS BOUNDARY ARRIVE ACROSS THE FAR SOUTHERN TEXAS PANHANDLE BY
DAYBREAK SATURDAY WITH NORTH WINDS QUICKLY ACCELERATING TO 15-25
MPH AFTER SUNRISE. FALLING TEMPERATURES WILL RESULT THROUGHOUT THE
DAY VIA POTENT COLD AIR ADVECTION...WITH READINGS APPROACHING
FREEZING IN THE NORTHWEST BY LATE AFTERNOON. THE WESTERN EXTENT OF
SOME ENHANCED GULF MOISTURE MAY BE ABLE TO HOLD FIRM ACROSS THE
ROLLING PLAINS...SO HAVE THUS MAINTAINED SHOWER MENTION ALONG WITH
A SLIM CHANCE OF A THUNDERSTORM BEFORE THE COLD AIR POURS
IN...ALTHOUGH MAY BE ABLE TO EVENTUALLY PULL THUNDER PENDING THE
SPEED OF THE FRONT.
UPPER LOW DIGGING THROUGH ARIZONA WILL SLOWLY TRAVERSE EASTWARD WITH
DEEP LAYER LIFT INCREASING ACROSS THE WESTERN SOUTH PLAINS HEADING
INTO SATURDAY EVENING. TRENDS CONTINUE FOR THIS SYSTEM TO SLOW AS
IT PUSHES EASTWARD...WHICH IS TYPICAL OF A STORM OF THIS CALIBER.
PRECIPITATION SHOULD BEGIN TO FALL ACROSS THE SOUTH PLAINS AND FAR
SOUTHWEST PANHANDLE AS THE UPPER LEVEL AND ISENTROPIC LIFT
INCREASE SATURDAY EVENING...SPREADING EAST INTO THE OVERNIGHT
HOURS. SNOW LOOKS TO BE THE DOMINANT MODE ACROSS THE TYPICAL
SNOWBELT AT THE ONSET...WHILE A MIX WILL BE FOUND FARTHER SOUTH
AND EAST INITIALLY. RAPID DYNAMIC COOLING COMBINED WITH WET
BULBING SHOULD MEAN MORE SLEET AS OPPOSED TO FREEZING RAIN DURING
THE MIXED PHASE STAGE SATURDAY EVENING/NIGHT...WITH SNOW TAKING
OVER BY DAYBREAK SUNDAY. INSTABILITY AND SATURATION IN THE
DENDRITIC GROWTH LAYER CONTINUE TO LOOK FAVORABLE FOR THE THREAT
OF HEAVY SNOW...WITH AMOUNTS OF AT LEAST 4 INCHES LOOKING LIKE A
GOOD BET. WILL HOLD OFF ON WATCH ISSUANCE FOR ANOTHER PERIOD OR
TWO TO BETTER PINPOINT TIMING AND TRACK OF THE SYSTEM.
THE MAJORITY OF THE SNOW THAT FALLS WILL BE OF THE BLOWING/DRIFTING
VARIETY GIVEN THE PROLONGED PERIOD OF BRISK NORTHERLY WINDS EXPECTED
ON THE NORTH/NORTHWEST QUADRANT OF THE PARENT UPPER LOW. WHILE
TRAVEL IS HIGHLY DISCOURAGED SATURDAY NIGHT THROUGH AT LEAST EARLY
MONDAY...THOSE TRAVELING ON EAST-WEST ORIENTED HIGHWAYS WILL BE AT
GREATER RISK GIVEN THE PERPENDICULAR COMPONENT OF THE WINDS ALLOWING
FOR SNOW TO COVER ROADWAYS.
WIND CHILLS...INCLUDING SINGLE DIGIT AND BELOW ZERO READINGS...WILL
BE ANOTHER ISSUE OF CONCERN WITH TEMPERATURES REMAINING BELOW
FREEZING FROM LATE SATURDAY UNTIL LIKELY TUESDAY AFTERNOON. WIND
SPEEDS OF 25-35 MPH WILL PERSIST FROM SATURDAY NIGHT THROUGH
SUNDAY...WHILE STILL REMAINING ABOVE 20 MPH INTO MONDAY.
SPEED/TRACK OF THE UPPER LOW WILL DETERMINE HOW LONG SNOW PERSISTS INTO
MONDAY...BUT NONETHELESS SHOULD SEE THE SNOW AND WIND TAPER OFF
DURING THE DAY. HOWEVER...TRAVEL WILL STILL BE TREACHEROUS GIVEN
EXPECTED TEMPERATURES BELOW FREEZING AND SUBSEQUENT LACK OF
SNOWMELT. A SERIES OF DISTURBANCES THROUGH NEXT WEEK WILL LEAD TO
A COOL END TO THE YEAR...INCLUDING CRISP NIGHTS WHERE SNOWPACK
REMAINS IN PLACE. TRACK OF THESE SYSTEMS CURRENTLY APPEAR TOO FAR
NORTH TO WARRANT PRECIPITATION MENTION.
AS I SIGN OFF THIS MORNING...I WOULD LIKE TO LET EVERYONE KNOW WHAT
A PLEASURE IT HAS BEEN SERVING THE FOLKS OF THE SOUTH PLAINS REGION.
THANK YOU FOR MAKING MY TIME SPENT IN WEST TEXAS MEMORABLE AND
ENJOYABLE...AND I VERY MUCH LOOK FORWARD TO FUTURE RETURN VISITS. I
WISH ALL OF YOU A VERY MERRY CHRISTMAS AND A HAPPY NEW YEAR!
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/31...END...
AREA FORECAST DISCUSSION
NWS RENO NV
135 PM PST THU DEC 24 2015
.SYNOPSIS...
AFTER HEAVY SNOW SHOWERS MOVE OUT TONIGHT, A FEW LIGHT SNOW
SHOWERS REMAIN POSSIBLE ON FRIDAY. FRESH SNOWCOVER WILL LEAD TO
WIDESPREAD COLD TEMPERATURES CHRISTMAS DAY THROUGH THE WEEKEND. A
WEAKENING STORM WILL BRING LIGHT SNOW SHOWERS TO THE REGION
MONDAY, WITH POTENTIAL FOR A SLIDER WEDNESDAY OR THURSDAY
PROVIDING A CHANCE FOR SNOW IN NORTHERN AND WESTERN NEVADA.
&&
.SHORT TERM...
ONGOING WINTER STORM BEHAVING MORE OR LESS AS EXPECTED WITH
SIGNIFICANT TRAVEL IMPACTS CONTINUING INTO THE EVENING HOURS.
WE`VE SEEN BIG DELAYS AND TEMPORARY ROAD CLOSURES OVER THE SIERRA,
AND DELAYS/DIVERSION INTO RNO AIRPORT DUE TO HEAVY SNOW AND LOW
VISIBILITY. OVERALL THE BULK OF THE HEAVY SNOW SHOWERS WILL SETTLE
SOUTHWARD THROUGH THE AFTERNOON AND EVENING. SEE OUR SOCIAL MEDIA
AND LSR FOR SPECIFIC SNOW REPORTS. MAIN FORECAST ISSUES ARE --
* WITH NUMEROUS REPORTS OF 20:1 SNOW RATIOS (UNSURPRISING) AND
BURSTS OF HEAVY PRECIP SEEN IN THE HRRR, I`VE INCREASED SNOW
TOTAL FORECASTS FOR THE SIERRA FRONT, TAHOE, AND MONO CO
REGIONS. SNOW AMOUNTS WILL VARY A LOT DUE TO SHOWERY/BANDED
NATURE OF THE PRECIP GIVEN UNSTABLE AIRMASS. LAKE EFFECT OFF OF
TAHOE HAS OCCURRED PERIODICALLY TODAY AND THE RISK CONTINUES
INTO EARLY EVENING WITH WESTERLY FLOW ALOFT FOR CARSON
CITY/CARSON VALLEY. OVERALL MESSAGE IS THE SAME THOUGH - ROUGH
TRAVEL ON ROADS AREAWIDE THROUGH THIS EVENING, WITH AREAS OF
BLOWING SNOW AND ZERO VISIBILITY IN THE MOUNTAINS. REFREEZE OF
MELTED SNOW ON ROADS WILL BE AN ISSUE TOO TONIGHT.
* GUIDANCE IS SHOWING A SECONDARY WAVE ALOFT DROPPING IN LATE
TONIGHT AND FRIDAY, WHICH COULD SPARK ADDITIONAL SNOW SHOWER
DEVELOPMENT. LOCATION OF THIS ACTIVITY HIGHLY VARIABLE IN THE
SIMULATIONS BUT BEST BET IS THE SIERRA WITH A SLIGHT UPSLOPE
COMPONENT, BUT AIRMASS REMAINS COLD AND UNSTABLE AREA WIDE SO WE
CAN`T RULE OUT SHSN ANYWHERE FRIDAY. A QUICK 1-3" ACCUM POSSIBLE
DEPENDING ON HOW ROBUST THE SHOWERS BECOME.
CS
.LONG TERM...SATURDAY TO WEDNESDAY...
COLD PROGRESSIVE FLOW WILL CONTINUE INTO THE WEST COAST WHICH MAY
ALLOW A COUPLE FAST MOVING SYSTEMS TO IMPACT THE AREA INTO THE
MIDDLE OF NEXT WEEK.
AS THE CURRENT TROUGH OVER THE REGION EXITS ON FRIDAY NIGHT,
NORTHEAST TO EAST WINDS WILL DEVELOP IN THE SIERRA AND TAHOE BASIN.
HAVE ISSUED A LAKE WIND ADVISORY FOR TAHOE FOR FRIDAY NIGHT AND
SATURDAY MORNING WITH WAVES UP TO 4 FEET AND GUSTS NEAR 35 MPH.
FOR THE WEEKEND, CONDITIONS WILL BE DRY AND COLD. OVERNIGHT LOWS
WILL BE BELOW ZERO IN MOST SIERRA VALLEYS AND IN THE -5 TO 15 RANGE
ACROSS WESTERN NEVADA AND NORTHEAST CALIFORNIA WITH THE FRESH SNOW
COVER. VALLEY INVERSIONS WILL LIKELY DEVELOP AND KEEP AFTERNOON
HIGHS IN THE 20S TO LOW 30S.
NEXT SYSTEM SHOULD ARRIVE IN TIME FOR THE MONDAY MORNING COMMUTE.
LIQUID AMOUNTS IN THE MODELS ARE LESS THAN 0.10 INCH, WITH SNOW
LEVELS NEAR AND BELOW 4000 FEET. SNOW AMOUNTS SHOULD BE LESS THAN AN
INCH FOR MOST LOCATIONS, THOUGH EVEN A HALF INCH OF SNOW COULD CAUSE
TRAVEL ISSUES FOR THE MONDAY MORNING COMMUTE.
MODELS SHOW A SECOND SLIDER SYSTEM FOR MID WEEK, BUT TRACK WILL
DEPEND ON WHERE THE EASTERN PACIFIC RIDGE SETS UP. FOR NOW THE TRACK
OF THIS SYSTEM VARIES BETWEEN WESTERN NEVADA AND UTAH. IF THE TRACK
IS OVER WESTERN NEVADA, ANOTHER ROUND OF SNOW ON VALLEY FLOORS IS
LIKELY. SOMETHING TO KEEP AN EYE ON OVER THE NEXT FEW DAYS. BRONG
&&
.AVIATION...
SNOW SHOWERS WILL BRING QUICK VARIATIONS IN FLIGHT CONDITIONS FOR
AREA AIRPORTS, RANGING FROM VFR TO LIFR IN A MATTER OF MINUTES.
BASED ON THE LATEST HRRR GUIDANCE, THE MAIN RISK AREA FOR THIS
WILL SETTLE SOUTHWARD THROUGH THE AFTERNOON AND EVENING. FOR
RNO/CXP 22Z-01Z WILL MARK THIS TRANSITION FROM HEAVIER SHOWERS TO
LIGHTER ONES, TVL/TRK SOMETIME BETWEEN 01-03Z, AND MMH 04-06Z.
ADDITIONAL SNOW ACCUMULATIONS ARE LIKELY WITH RATES IN SHOWERS
1"/HOUR FOR RNO/CXP, AND POSSIBLY 2-3"/HR FOR TVL/TRK/MMH.
AFTER 6Z/FRIDAY MAIN ISSUES WILL BE RESIDUAL CLOUDS AND LIGHT
SNOW SHOWERS NEAR THE MOUNTAINS, LEADING TO TERRAIN OBSCURATION.
SECONDARY WAVE ALOFT MAY BRING SOME MVFR SNOW SHOWERS TO THE
REGION BETWEEN 9Z/FRI-21Z/FRI. PREDICTABILITY OF THESE IS LOW DUE
TO VARYING TRACKS IN THE SIMULATIONS, SO AM ADDRESSING WITH VCSH
IN THE TAFS. MOST LIKELY AIRPORTS TO SEE THESE ARE TVL/TRK. CS
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ005.
LAKE WIND ADVISORY FROM 10 PM FRIDAY TO 10 AM PST SATURDAY FOR
LAKE TAHOE IN NVZ002.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ001-004.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ003.
CA...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ071.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING CAZ070.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY CAZ073.
LAKE WIND ADVISORY FROM 10 PM FRIDAY TO 10 AM PST SATURDAY FOR
LAKE TAHOE IN CAZ072.
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...UPDATED
NWS RENO NV
1014 AM PST THU DEC 24 2015
.UPDATE...
SO WE HAVE A RESPECTABLE WINTER STORM ON OUR HANDS TODAY! THIS AT
THE SAME TIME NEW YORK CITY IS 70 DEGREES ON CHRISTMAS EVE!
WIDESPREAD HEAVY SNOW SHOWERS ACROSS THE REGION WITH REPORTS OF
1-2"/HOUR RATES IN THE VALLEYS INCLUDING AROUND RENO AND CARSON
CITY, WITH 3+"/HOUR IN THE SIERRA. VERY HIGH RATIO SNOWS, WITH A
COUPLE OBSERVATIONS OF AT LEAST 20:1. WE ARE SENDING OUT REPORTS
VIA LSR AS WE GET THEM, ALSO MONITOR OUR SOCIAL MEDIA FOR FREQUENT
UPDATES AND SNOW REPORTS. SUFFICE IT TO SAY ROADS ARE A MESS
ACROSS THE SIERRA, NE CALIFORNIA, AND FAR WESTERN NEVADA. WE ARE
ALSO SEEING NEAR BLIZZARD CONDITIONS OVER THE PASSES WITH BLOWING
SNOW. GOES WITHOUT SAYING THAT TRAVEL IS NOT RECOMMENDED.
FOR NEXT 12 HOURS, THE BIG PICTURE REMAINS THE SAME WITH HEAVY
SNOW SHOWERS CONTINUING INTO EARLY AFTERNOON THEN GRADUALLY
WORKING SOUTH AND EAST INTO THE BALANCE OF THE AFTERNOON AND
EVENING. THIS IS SHOWN WELL IN THE LATEST HRRR GUIDANCE, WITH SOME
IMPRESSIVE QPF ENHANCEMENTS AT TIMES. AIRMASS IS QUITE UNSTABLE
LEADING TO HIGH SNOWFALL RATES AND NUMEROUS BANDS OF SNOW.
THEREFORE AMOUNTS WILL VARY OVER THE REGION. ONE SUCH BAND IS NOW
TRAINING JUST SOUTH OF I-80 INCLUDING THE RENO/SPARKS AREA -
SHOULD THIS CONTINUE WE COULD EASILY SEE 5" OR MORE IN THESE
AREAS. WHILE LOCATIONS 5-10 MILES TO THE NORTH WILL SEE LESS.
NO CHANGES PLANNED TO THE ADVISORIES/WARNINGS AS THE MESSAGE IS
ALREADY OUT THERE. WILL SEND UPDATE TO GRIDDED FORECAST SHORTLY.
CS
&&
.PREVIOUS DISCUSSION... /ISSUED 329 AM PST THU DEC 24 2015/
SYNOPSIS...
A COLD FAST MOVING STORM WILL BRING PERIODS OF HEAVY SNOW AND SNOW
SHOWERS TO THE SIERRA AND WESTERN NEVADA TODAY AND TONIGHT. SNOW
COVERED ROADS AND BLOWING SNOW ARE LIKELY FOR MUCH OF THE REGION.
COLD CONDITIONS ARE ON TAP FOR CHRISTMAS DAY INTO THE WEEKEND.
WHILE MOST OF NEXT WEEK APPEARS DRY WITH A SLOW WARMING TREND, ONE
OR TWO WEAK STORMS MAY IMPACT THE AREA WITH LIGHT PRECIPITATION.
SHORT TERM...
RAISED WINDS SLIGHTLY FOR THE HIGHWAY 395 CORRIDOR NEAR AND SOUTH
OF HIGHWAY 203 (MAMMOTH LAKES) THIS AFTERNOON, OTHERWISE MINIMAL
CHANGE TO THE SHORT TERM FORECAST. ALL WARNINGS AND ADVISORIES FOR
TODAY STILL LOOK ON TRACK.
LOOKING AT THE INFRARED AND WATER VAPOR SATELLITES, THE UPPER JET
CORE HAS DROPPED INTO CENTRAL CALIFORNIA/SOUTHERN NEVADA (DRY SLOT
IN WATER VAPOR) WITH COLDER CLOUD TOPS MOVING INTO NORTHERN
CALIFORNIA AND NORTHWEST NEVADA AHEAD OF THE UPPER LOW CORE OFF
THE OREGON COAST. THERE WAS CLOUD-TO-GROUND LIGHTNING WITH THE
MAIN BAND AS IT MOVED ASHORE NEAR ARCATA, CA A FEW HOURS AGO,
INDICATIVE OF THE INSTABILITY AND CONVECTIVE NATURE OF THE COLD
LOW (100-250 J/KG OF CAPE NEAR COAST PER 10Z SPC MESOANALYSIS).
WIDESPREAD SHOWERS OVER NORTHERN CALIFORNIA WILL CONTINUE TO DRIVE
SOUTH AND EAST THIS MORNING, WITH THE 09Z HRRR BRINGING SNOW AND
SNOW SHOWERS TO ALL OF THE NORTHERN SIERRA AND WESTERN NEVADA (TO
ABOUT HIGHWAY 50) BETWEEN ~5-9 AM. SHOWERS WILL SPREAD SOUTH OVER
EASTERN MONO AND MINERAL COUNTIES THIS AFTERNOON. THERE COULD BE
A WIDE RANGE OF SNOWFALL TOTALS THROUGH THIS AFTERNOON, ESPECIALLY
EAST OF THE SIERRA, AS LOCALIZED HEAVY SNOW BANDS DEPOSIT IN SOME
AREAS AND NOT OTHERS. LAKE EFFECT SNOW IS ALSO LIKELY TO BRING
SOME LOCALLY HIGHER AMOUNTS DOWNWIND OF LAKE TAHOE AND EVENTUALLY
(~LATE AFTERNOON) PYRAMID LAKE TODAY. IN FACT, THERE ARE SIGNS
THAT LAKE TAHOE IS ALREADY FIRING UP SOME LAKE EFFECT SNOW NEAR
AND NORTH OF HIGHWAY 50 IN FAR WESTERN NEVADA.
BRIEFLY TURNING TO WINDS, THEY SHOULD GUST MAINLY INTO THE 25-35 MPH
RANGE TODAY AHEAD OF THE PRECIPITATION BAND. HOWEVER, LOCAL GUSTS
OF 40-50 MPH ARE POSSIBLE IN WIND PRONE AREAS ALONG HIGHWAY 395
SOUTH OF RENO THROUGH MONO COUNTY AND OUT INTO FAR WESTERN MINERAL
AND SOUTHERN LYON COUNTIES.
THE MAIN AREA OF SNOW SHOWERS DROPS SOUTH OF I-80 THIS EVENING,
ALTHOUGH RESIDUAL SHOWERS ARE POSSIBLE THROUGH TONIGHT ESPECIALLY
DOWNWIND OF PYRAMID LAKE AND PERHAPS LAKE TAHOE (THIS EVENING
ESPECIALLY). THE NAM HAS FINALLY BACKED OFF ON A SECOND SHOT OF
SNOW FOR CHURCHILL AND PERSHING COUNTIES TONIGHT, MORE IN LINE
WITH OTHER MODELS. ANY SNOW ACCUMULATIONS TONIGHT SHOULD REMAIN
LIGHT FOR WESTERN NEVADA, EXCEPT DOWNWIND OF PYRAMID LAKE WHERE
SEVERAL INCHES CANNOT BE RULED OUT. FOR THE SIERRA, WESTERN MONO
AND ALPINE COUNTIES COULD SEE ANOTHER 4-8 INCHES TONIGHT AS
UNSTABLE, MOIST UPSLOPE FLOW PUSHES SNOW ACROSS THE CREST INTO THE
EASTERN SIERRA.
CHRISTMAS DAY THROUGH THE WEEKEND WILL REMAIN COLD UNDER NORTH-
EAST FLOW AS THE TROUGH SLOWLY EXITS. LOWS WILL WE QUITE COLD BY
FRIDAY NIGHT AS CLEARING WORKS INTO THE REGION, WITH BELOW ZERO
READINGS LIKELY FOR THE COLDER, SNOW-COVERED VALLEYS OF WESTERN
NEVADA (OUTSIDE MAIN URBAN AREAS) AND CERTAINLY FOR THE SIERRA
VALLEYS. VALLEY INVERSIONS SHOULD BECOME QUITE STRONG BY SATURDAY
AND SATURDAY NIGHT AS A RIDGE BUILDS OVERHEAD. SNYDER
LONG TERM...SUNDAY THROUGH WEDNESDAY...
FEW CHANGES MADE TO THE LONG TERM AS THE MODELS AND ENSEMBLES DEPICT
A MEAN RIDGE DEVELOPING ALONG THE COAST. THEY STILL DEPICT WEAK
WAVES MOVING THROUGH THE RIDGE OR DROPPING DOWN THE EAST SIDE INTO
THE MIDDLE OF NEXT WEEK. THE MONDAY SYSTEM LOOKS TO BE THE
STRONGEST, BUT IT REALLY IS QUITE WEAK OVERALL. THE MAIN DIFFERENCES
IN THE MODELS ARE THAT THE GFS IS A BIT FURTHER EAST WITH THE RIDGE
AND HAS THE SYSTEMS THAT DROP DOWN FROM THE NORTH INTO EASTERN
NEVADA. THE EC HAS THEM DROPPING INTO WESTERN NEVADA LIKE INSIDE
SLIDERS. HAVE USED A BLEND OF ALL GUIDANCE AS TRACKING THESE
INDIVIDUAL WAVES IS FUTILE AT BEST 5-7 DAYS OUT.
SUNDAY WILL STILL BE COLD IN THE VALLEYS UNDER A STRONG INVERSION
WHILE MTNS WARM. WITH THE MONDAY SYSTEM, THE BEST CHANCE OF SNOW
SHOWERS LOOKS TO BE IN THE SIERRA FROM TAHOE NORTH AND ALONG THE
OREGON BORDER. IT WILL ALSO HELP TO IMPROVE MIXING A BIT WITH COOLER
TEMPS ALOFT. TUESDAY AND WEDNESDAY, TWO MORE WEAK SYSTEMS WILL DROP
IN FROM THE NORTH. FOR NOW, HAVE KEPT IN A SLIGHT CHANCE OF SHOWERS
FOR TUESDAY ACROSS THE NORTH AND LEFT WEDNESDAY DRY. HAVE GONE WITH
A SLOW WARMING TREND, ESPECIALLY IN THE MOUNTAINS DUE TO BETTER
MIXING. HOWEVER, IF THERE IS ENOUGH SNOW COVER LEFT BY WEDNESDAY IN
WRN NV VALLEYS, THEY COULD BE TRAPPED UNDER A STRONG INVERSION
AGAIN. WALLMANN
AVIATION...
MAIN CONCERN IS THE SHSN MOVING THROUGH THE SIERRA AND WESTERN
NEVADA TODAY. IFR CONDS THRU 21-00Z FOR KTRK/KTVL THEN SOME MVFR
CONDS THRU 06Z BEFORE IMPROVING. KRNO/KCXP 2-3 HR PERIOD OF IFR
CONDS BETWEEN 15-20Z WITH OCNL MVFR 20-01Z IN -SHSN. KMMH IFR
CONDS 18-01Z THEN GRADUALLY IMPROVING AS WELL. RUNWAY ACCUMS STILL
LOOK TO BE AROUND 6" KTRK/KTVL 2-4" KRNO/KCXP AND 4-6" FOR KMMH.
EXPECT ALL TERMINALS VFR AFTER 09Z FRI.
OTHER CONCERN IS WINDS WITH RIDGE GUSTS 60 KTS ATTM. SOME LLWS THIS
MORNING THRU 15-17Z BEFORE SNOW COMMENCES AND WINDS CLOSER TO
SURFACE ABATE. OTHERWISE SFC WND GUSTS TO 25 KTS MOST LIKELY AT ALL
TERMINALS FROM S-SW THRU 03Z. EXCEPTION WILL BE KMMH WHERE WNW FLOW
ALOFT ALIGNS BETTER AND PEAK GUSTS TO 40-45 KTS POSSIBLE 15-03Z.
WALLMANN
REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ005.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 10 PM PST THIS
EVENING NVZ001-003-004.
CA...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ071-072.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING CAZ070.
WINTER STORM WARNING FROM 10 AM THIS MORNING TO 4 AM PST FRIDAY
CAZ073.
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ005.
WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ001-004.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING NVZ003.
CA...WINTER STORM WARNING UNTIL 10 PM PST THIS EVENING CAZ071.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING CAZ070.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY 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 CHICAGO/ROMEOVILLE IL
156 PM CST THU DEC 24 2015
.UPDATE...
1023 AM...MORNING UPDATE...SHORT TERM/HI RES GUIDANCE SUGGESTING
WAVE OVER MISSOURI MAY BE SUFFICIENT FOR SOME SPRINKLES OR BRIEF
LIGHT RAIN ACROSS SOUTH/CENTRAL PARTS OF THE CWA THIS AFTERNOON
AND ADDED SLIGHT CHANCE MENTION OF THIS AFTERNOON. CLOUD COVER
ALSO EXPECTED TO FILL BACK IN WITH THIS WAVE AND THAT MAY KEEP
TEMPS FROM RISING MUCH BEYOND UPPER 30S NORTH TO MID 40S SOUTH.
A SECOND WAVE BACK OVER WESTERN IOWA WILL BE LIFTING NORTHEAST
THIS AFTERNOON AND THIS EVENING. 12Z NAM AND GFS SHOW THE BULK OF
THE PRECIP WITH THIS WAVE LIFTING NORTH OF THE CWA THIS EVENING.
THIS TREND ALSO SEEMS SUPPORTED BY THE RAP THOUGH THE HRRR STILL
MAINTAINS PRECIP INTO THE MID/LATE EVENING...MAINLY ACROSS FAR
NORTHWEST IL. ANY PRECIP THAT DOES OCCUR IS LIKELY TO BE LIGHT
AND WITH TEMPS PROBABLY STILL AT OR ABOVE FREEZING AT THAT
TIME...DOUBTFUL THERE WOULD BE ANY SNOW ACCUMULATION. CMS
&&
.SHORT TERM...
249 AM CST
THROUGH TONIGHT...
WINDS HAVE BEGUN TO CALM DOWN AFTER SEEING GUSTS EARLY THIS MORNING
OVER 40 MPH...BUT WITH SFC RIDGING ARRIVING THE GRADIENT WILL
CONTINUE TO DECREASE THROUGHOUT THE MORNING. BY MIDDAY WINDS SHOULD
BE GENERALLY SOUTHWEST BETWEEN 10 TO 20 MPH. THE LOW THAT BROUGHT
THE SEVERE WEATHER TO THE REGION HAS ALREADY LIFTED TO NEAR JAMES
BAY IN ONTARIO. DESPITE THE QUIET CONDITIONS FOR THE BULK OF THE
DAY...THE LARGEST CHALLENGE WILL BE ON HOW THE STRATUS LAYER
EVOLVES. IR IMAGERY SHOWS A LARGE STRATUS DECK SLIDING SOUTHEAST
ACROSS NORTHERN IL STRETCHING NORTHWEST THROUGH IOWA/MINNESOTA. HI-
RES GUIDANCE CONTINUES TO FEED CLOUDS ACROSS THE NORTHERN HALF OF
THE CWFA...WHICH COULD RESULT IN TEMPS BEING COOLER THEN PRESENT
HIGHS PROGGED AROUND 40 IN THE NORTHWEST AND LOW/MID 40S FOR
CENTRAL/SOUTHERN CWFA. DEW POINTS WILL BE HOVERING IN THE UPR 20S
DUE TO THE LACK OF STRONG SUBSIDENCE.
FURTHER UPSTREAM ACROSS THE CENTRAL ROCKIES IS A STRONGER MID-LVL
VORT...IR IMAGERY IS DEPICTING THIS FEATURE WELL AND MOST
OPERATIONAL SOLUTIONS HAVE THE TRAJECTORY OF THE MID-LVL WAVE
SLIDING EAST/NORTHEAST ACROSS IOWA INTO SOUTHERN WISC BY THIS
EVENING. THE CONCERN IS THAT IF THE STRATUS LAYER REMAINS IN PLACE
ACROSS THE FORECAST AREA...THE MID-LVL WAVE MAY ACT AS A CATALYST
AND QUICKLY SATURATE FROM TOP/DOWN THE PROFILE. WHILE THERE IS A
SHALLOW WARM LAYER...IT IS CONCEIVABLE THAT THIS COULD ERODE QUICKLY
IF DEW POINTS REMAIN IN THE UPR 20S/NEAR 30. IF INDEED THE WAVE
AGITATES THE ENVIRONMENT AND PRODUCES PRECIP...IT WOULD LIKELY FALL
AS RAIN AT THE ONSET...THEN THERMAL COOL DOWN TO SUPPORT A RAIN/SNOW
MIX BEFORE GOING OVER TO LIGHT SNOW AROUND 2-4Z. HAVE OPTED TO BLEND
MORE WITH THE SREF/GFS IN TIMING...BRINGING PRECIP INTO NORTHWEST
CWFA MID/LATE AFTN AND SPREADING EAST TOWARDS THE CHICAGO METRO BY
00-02Z. QPF LOOKS VERY LOW...BUT COULD EASILY SEE WHAT SNOW FALLS TO
PERHAPS PRODUCE A FEW TENTHS OF AN INCH BEFORE ENDING. SFC CONDS
SHOULD BE WARM ENOUGH TO LIMIT ANY ACCUMULATIONS...BUT IF THE MID-
LVL WAVE IS ABLE TO EFFICIENTLY PRODUCE MOISTURE THEN QPF COULD BE
HIGHER AS WELL AS PERHAPS UP TO ONE HALF INCH OF SNOW.
TEMPS OVERNIGHT SHOULD COOL OFF INTO THE UPR 20S IN THE NORTH...BUT
REMAIN IN THE LOW TO PERHAPS MID 30S IN THE FAR SOUTH.
BEACHLER
&&
.LONG TERM...
249 AM CST
FRIDAY THROUGH WEDNESDAY...
CHRISTMAS DAY THROUGH SATURDAY... SFC RIDGING THEN ABSORBS THE
REMAINING LOW LEVEL MOISTURE EARLY CHRISTMAS DAY WITH DRY CONDS AND
P-CLOUDY SKIES EXPECTED FOR MUCH OF THE DAY. WITH THE LACK OF COLD
AIR IN PLACE...TEMPS WILL LIKELY REBOUND INTO THE MID/UPR 40S. ONE
CAVEAT IS THAT WINDS WILL BE TURNING NORTHEAST...WHICH COULD KEEP
THE AREAS ADJACENT TO LAKE MICHIGAN A FEW DEGREES COOLER. BY
CHRISTMAS NIGHT OPERATIONAL GUIDANCE CONTINUES TO PROG A DEVELOPING
SHORTWAVE ACROSS THE LEE-SIDE OF THE SOUTHERN ROCKIES. WITH THE
500MB TROUGH PARKED ACROSS THE FOUR-CORNERS REGION OF THE
CONUS...SOUTHERLY FLOW OF MOISTURE APPEARS POISED TO STREAM NORTH
FROM THE WESTERN GULF. SO TEMPS MAY ONLY FALL SLIGHTLY CHRISTMAS
NIGHT BEFORE WARMING OVERNIGHT. PRECIP SHOULD OVERSPREAD THE REGION
BY EARLY SATURDAY...AND BE WARM ENOUGH INITIALLY TO SUPPORT RAIN.
UNSEASONABLY WARM/MOIST CONDITIONS CONTINUE INTO SAT...WITH DEW
POINTS YET AGAIN PUSHING INTO THE LOW 50S IN THE FAR SOUTHERN CWFA.
GUIDANCE CONTINUES TO INDICATE SOME MID-LVL INSTABILITY WITH A
SERIES OF WEAK SHORTWAVES LIFTING NORTHEAST ALONG A QUASI-STATIONARY
BOUNDARY...SO HAVE HELD ONTO THE MENTION OF THUNDER IN THE SOUTH.
SUNDAY THROUGH WEDNESDAY... FOR THE SECOND HALF OF THE WEEKEND
OPERATIONAL GUIDANCE HAS BEEN BOUNCEING BETWEEN THE PLACEMENT OF THE
FRONTAL BOUNDARY...BUT NOW APPEARS FAVORABLE TO PUSH SOUTH OF THE
FORECAST AREA BY SUN MIDDAY WITH A STRONG CANADIAN SFC RIDGE
DROPPING SOUTH INTO THE NORTHERN PLAINS EARLY SUN...THEN STRETCHING
EAST SUN NGT TO COVER MUCH OF THE GREAT LAKES AND PUSH THE BOUNDARY
FURTHER SOUTH. ENSEMBLES CONTINUE TO SHOW THAT THE SFC RIDGE MAY BE
STRONG ENOUGH TO HOLD THE FRONTAL BOUNDARY FURTHER SOUTH INTO
MONDAY...WHICH MAY FURTHER DELAY MOISTURE FROM LIFTING BACK ACROSS
THE REGION UNTIL MON NGT/TUE.
MID-LVL FLOW DOES BEGIN TO TRANSITION TOWARDS A SEMI-ZONAL SETUP
MON...WHICH COULD AID IN EJECTING THE SFC RIDGE BACK EAST EARLIER
MON AND ALLOW THE BOUNDARY AND DEVELOPING SHORTWAVE TO QUICKLY LIFT
NORTH DURING THE DAY MON. IT IS POSSIBLE THAT THE NORTHERN EDGE OF
THE PRECIP SHIELD...ONCE IT DOES RETURN NORTH...COULD START AS A
WINTRY MIX BEFORE WARMING AND TRANSITIONING OVER TO ALL RAIN. BUT
GIVEN THE LOW CONFIDENCE IN THE PRECISE PLACEMENT OF THE
LOW/BOUNDARY...THIS PERIOD WILL LIKELY UNDERGO ADDITIONAL CHANGES.
TEMPS TOWARDS NEXT WEEK APPEAR TO LEAN TOWARDS CLIMO WITH HIGHS IN
THE LOW/MID 30S...BUT LOWS WILL LIKELY SEE SOME MODERATION GIVEN
EXPECTED CLOUD COVER AND REMAIN IN THE MID/UPR 20S TO AROUND 30.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 20Z...
* SLIGHT CHANCE FOR LIGHT PCPN LATE THIS AFTERNOON OR EARLY THIS
EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...
THE GUSTY WSWLY WINDS ARE DIMINISHING AS DEEP LOW PRESSURE
CONTINUES TO PULL AWAY TO THE NORTHEAST AND HIGH PRESSURE BUILDS
ACROSS THE MIDDLE MISSISSIPPI VALLEY AND THE OHIO VALLEY. THE WIND
SPEED TREND WILL CONTINUE DOWN...BECMG LGT/VRBL THIS EVENING AND
OVERNIGHT AS THE PRESSURE GRADIENT ACROSS THE REGION BECOMES VERY
WEAK.
A WEAK MID LEVEL IMPULSE TRACKING FROM IOWA THIS AFTERNOON AND
ACROSS THE AREA AROUND THE WISCONSIN-ILLINOIS BORDER HAS THE
POTENTIAL TO GENERATE SOME PCPN...BUT FORECAST MOISTURE PROFILES
INDICATE CONDITIONS BELOW 5KFT SHOULD BE RATHER DRY AND A
SATURATED LAYER WITH WEAK FORCING LOOKS TO RATHER SHALLOW.
SO...WHILE THERE IS A SLIGHT CHANCE FOR RAIN OR A RAIN/SNOW
MIX...CHANCES ARE TOO LOW TO INCLUDE IN THE TAFS...AND MAY
ULTIMATELY END UP BEING MORE VIRGA THAN ACTUAL PCPN REACHING THE
GROUND.
FOR TOMORROW...WITH THE CENTER OF HIGH PRESSURE OVER SRN WISCONSIN
AND A DRY AIRMASS ACROSS THE REGION...EXPECT ONLY OPERATIONALLY
INSIGNIFICANT CLOUD COVER AND LIGHT NELY WINDS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* MEDIUM CONFIDENCE THAT THE TERMINALS WILL REMAIN DRY THROUGH
THE PERIOD.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF RAIN.
SATURDAY...RAIN SHOWERS LIKELY. CHANCE OF MVFR/IFR.
SUNDAY...VFR.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
WEDNESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
350 AM CST
HIGH WINDS AND WAVES CONTINUING ACROSS THE ENTIRE LAKE THIS
MORNING. THE STRONGEST WINDS ARE CURRENTLY OCCURRING OVER THE
NORTH HALF WHERE STORM FORCE WINDS ARE STILL ONGOING. THESE STORM
FORCE WINDS WILL CONTINUE THROUGH MID MORNING...WITH GALES
PERSISTING THEN INTO THE AFTERNOON. GALES ARE STILL OCCURRING
ACROSS THE SOUTH HALF/NEARSHORE...AND WITH THESE SPEEDS EXPECTED
TO CONTINUE THROUGH MID MORNING AS WELL. SPEEDS WILL CONTINUE TO
DIMINISH OVER THE ENTIRE LAKE THIS AFTERNOON AND THIS
EVENING...WITH A PERIOD OF LIGHTER WINDS TO END THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSCHICAGO
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WWW.YOUTUBE.COM/NWSCHICAGO
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1121 AM CST THU DEC 24 2015
.UPDATE...
1023 AM...MORNING UPDATE...SHORT TERM/HI RES GUIDANCE SUGGESTING
WAVE OVER MISSOURI MAY BE SUFFICIENT FOR SOME SPRINKLES OR BRIEF
LIGHT RAIN ACROSS SOUTH/CENTRAL PARTS OF THE CWA THIS AFTERNOON
AND ADDED SLIGHT CHANCE MENTION OF THIS AFTERNOON. CLOUD COVER
ALSO EXPECTED TO FILL BACK IN WITH THIS WAVE AND THAT MAY KEEP
TEMPS FROM RISING MUCH BEYOND UPPER 30S NORTH TO MID 40S SOUTH.
A SECOND WAVE BACK OVER WESTERN IOWA WILL BE LIFTING NORTHEAST
THIS AFTERNOON AND THIS EVENING. 12Z NAM AND GFS SHOW THE BULK OF
THE PRECIP WITH THIS WAVE LIFTING NORTH OF THE CWA THIS EVENING.
THIS TREND ALSO SEEMS SUPPORTED BY THE RAP THOUGH THE HRRR STILL
MAINTAINS PRECIP INTO THE MID/LATE EVENING...MAINLY ACROSS FAR
NORTHWEST IL. ANY PRECIP THAT DOES OCCUR IS LIKELY TO BE LIGHT
AND WITH TEMPS PROBABLY STILL AT OR ABOVE FREEZING AT THAT
TIME...DOUBTFUL THERE WOULD BE ANY SNOW ACCUMULATION. CMS
&&
.SHORT TERM...
249 AM CST
THROUGH TONIGHT...
WINDS HAVE BEGUN TO CALM DOWN AFTER SEEING GUSTS EARLY THIS MORNING
OVER 40 MPH...BUT WITH SFC RIDGING ARRIVING THE GRADIENT WILL
CONTINUE TO DECREASE THROUGHOUT THE MORNING. BY MIDDAY WINDS SHOULD
BE GENERALLY SOUTHWEST BETWEEN 10 TO 20 MPH. THE LOW THAT BROUGHT
THE SEVERE WEATHER TO THE REGION HAS ALREADY LIFTED TO NEAR JAMES
BAY IN ONTARIO. DESPITE THE QUIET CONDITIONS FOR THE BULK OF THE
DAY...THE LARGEST CHALLENGE WILL BE ON HOW THE STRATUS LAYER
EVOLVES. IR IMAGERY SHOWS A LARGE STRATUS DECK SLIDING SOUTHEAST
ACROSS NORTHERN IL STRETCHING NORTHWEST THROUGH IOWA/MINNESOTA. HI-
RES GUIDANCE CONTINUES TO FEED CLOUDS ACROSS THE NORTHERN HALF OF
THE CWFA...WHICH COULD RESULT IN TEMPS BEING COOLER THEN PRESENT
HIGHS PROGGED AROUND 40 IN THE NORTHWEST AND LOW/MID 40S FOR
CENTRAL/SOUTHERN CWFA. DEW POINTS WILL BE HOVERING IN THE UPR 20S
DUE TO THE LACK OF STRONG SUBSIDENCE.
FURTHER UPSTREAM ACROSS THE CENTRAL ROCKIES IS A STRONGER MID-LVL
VORT...IR IMAGERY IS DEPICTING THIS FEATURE WELL AND MOST
OPERATIONAL SOLUTIONS HAVE THE TRAJECTORY OF THE MID-LVL WAVE
SLIDING EAST/NORTHEAST ACROSS IOWA INTO SOUTHERN WISC BY THIS
EVENING. THE CONCERN IS THAT IF THE STRATUS LAYER REMAINS IN PLACE
ACROSS THE FORECAST AREA...THE MID-LVL WAVE MAY ACT AS A CATALYST
AND QUICKLY SATURATE FROM TOP/DOWN THE PROFILE. WHILE THERE IS A
SHALLOW WARM LAYER...IT IS CONCEIVABLE THAT THIS COULD ERODE QUICKLY
IF DEW POINTS REMAIN IN THE UPR 20S/NEAR 30. IF INDEED THE WAVE
AGITATES THE ENVIRONMENT AND PRODUCES PRECIP...IT WOULD LIKELY FALL
AS RAIN AT THE ONSET...THEN THERMAL COOL DOWN TO SUPPORT A RAIN/SNOW
MIX BEFORE GOING OVER TO LIGHT SNOW AROUND 2-4Z. HAVE OPTED TO BLEND
MORE WITH THE SREF/GFS IN TIMING...BRINGING PRECIP INTO NORTHWEST
CWFA MID/LATE AFTN AND SPREADING EAST TOWARDS THE CHICAGO METRO BY
00-02Z. QPF LOOKS VERY LOW...BUT COULD EASILY SEE WHAT SNOW FALLS TO
PERHAPS PRODUCE A FEW TENTHS OF AN INCH BEFORE ENDING. SFC CONDS
SHOULD BE WARM ENOUGH TO LIMIT ANY ACCUMULATIONS...BUT IF THE MID-
LVL WAVE IS ABLE TO EFFICIENTLY PRODUCE MOISTURE THEN QPF COULD BE
HIGHER AS WELL AS PERHAPS UP TO ONE HALF INCH OF SNOW.
TEMPS OVERNIGHT SHOULD COOL OFF INTO THE UPR 20S IN THE NORTH...BUT
REMAIN IN THE LOW TO PERHAPS MID 30S IN THE FAR SOUTH.
BEACHLER
&&
.LONG TERM...
249 AM CST
FRIDAY THROUGH WEDNESDAY...
CHRISTMAS DAY THROUGH SATURDAY... SFC RIDGING THEN ABSORBS THE
REMAINING LOW LEVEL MOISTURE EARLY CHRISTMAS DAY WITH DRY CONDS AND
P-CLOUDY SKIES EXPECTED FOR MUCH OF THE DAY. WITH THE LACK OF COLD
AIR IN PLACE...TEMPS WILL LIKELY REBOUND INTO THE MID/UPR 40S. ONE
CAVEAT IS THAT WINDS WILL BE TURNING NORTHEAST...WHICH COULD KEEP
THE AREAS ADJACENT TO LAKE MICHIGAN A FEW DEGREES COOLER. BY
CHRISTMAS NIGHT OPERATIONAL GUIDANCE CONTINUES TO PROG A DEVELOPING
SHORTWAVE ACROSS THE LEE-SIDE OF THE SOUTHERN ROCKIES. WITH THE
500MB TROUGH PARKED ACROSS THE FOUR-CORNERS REGION OF THE
CONUS...SOUTHERLY FLOW OF MOISTURE APPEARS POISED TO STREAM NORTH
FROM THE WESTERN GULF. SO TEMPS MAY ONLY FALL SLIGHTLY CHRISTMAS
NIGHT BEFORE WARMING OVERNIGHT. PRECIP SHOULD OVERSPREAD THE REGION
BY EARLY SATURDAY...AND BE WARM ENOUGH INITIALLY TO SUPPORT RAIN.
UNSEASONABLY WARM/MOIST CONDITIONS CONTINUE INTO SAT...WITH DEW
POINTS YET AGAIN PUSHING INTO THE LOW 50S IN THE FAR SOUTHERN CWFA.
GUIDANCE CONTINUES TO INDICATE SOME MID-LVL INSTABILITY WITH A
SERIES OF WEAK SHORTWAVES LIFTING NORTHEAST ALONG A QUASI-STATIONARY
BOUNDARY...SO HAVE HELD ONTO THE MENTION OF THUNDER IN THE SOUTH.
SUNDAY THROUGH WEDNESDAY... FOR THE SECOND HALF OF THE WEEKEND
OPERATIONAL GUIDANCE HAS BEEN BOUNCEING BETWEEN THE PLACEMENT OF THE
FRONTAL BOUNDARY...BUT NOW APPEARS FAVORABLE TO PUSH SOUTH OF THE
FORECAST AREA BY SUN MIDDAY WITH A STRONG CANADIAN SFC RIDGE
DROPPING SOUTH INTO THE NORTHERN PLAINS EARLY SUN...THEN STRETCHING
EAST SUN NGT TO COVER MUCH OF THE GREAT LAKES AND PUSH THE BOUNDARY
FURTHER SOUTH. ENSEMBLES CONTINUE TO SHOW THAT THE SFC RIDGE MAY BE
STRONG ENOUGH TO HOLD THE FRONTAL BOUNDARY FURTHER SOUTH INTO
MONDAY...WHICH MAY FURTHER DELAY MOISTURE FROM LIFTING BACK ACROSS
THE REGION UNTIL MON NGT/TUE.
MID-LVL FLOW DOES BEGIN TO TRANSITION TOWARDS A SEMI-ZONAL SETUP
MON...WHICH COULD AID IN EJECTING THE SFC RIDGE BACK EAST EARLIER
MON AND ALLOW THE BOUNDARY AND DEVELOPING SHORTWAVE TO QUICKLY LIFT
NORTH DURING THE DAY MON. IT IS POSSIBLE THAT THE NORTHERN EDGE OF
THE PRECIP SHIELD...ONCE IT DOES RETURN NORTH...COULD START AS A
WINTRY MIX BEFORE WARMING AND TRANSITIONING OVER TO ALL RAIN. BUT
GIVEN THE LOW CONFIDENCE IN THE PRECISE PLACEMENT OF THE
LOW/BOUNDARY...THIS PERIOD WILL LIKELY UNDERGO ADDITIONAL CHANGES.
TEMPS TOWARDS NEXT WEEK APPEAR TO LEAN TOWARDS CLIMO WITH HIGHS IN
THE LOW/MID 30S...BUT LOWS WILL LIKELY SEE SOME MODERATION GIVEN
EXPECTED CLOUD COVER AND REMAIN IN THE MID/UPR 20S TO AROUND 30.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* SLIGHT CHANCE FOR LIGHT PCPN LATE THIS AFTERNOON OR EARLY THIS
EVENING.
KREIN
//DISCUSSION...UPDATED 18Z...
THE GUSTY WSWLY WINDS ARE DIMINISHING AS DEEP LOW PRESSURE
CONTINUES TO PULL AWAY TO THE NORTHEAST AND HIGH PRESSURE BUILDS
ACROSS THE MIDDLE MISSISSIPPI VALLEY AND THE OHIO VALLEY. THE WIND
SPEED TREND WILL CONTINUE DOWN...BECMG LGT/VRBL THIS EVENING AND
OVERNIGHT AS THE PRESSURE GRADIENT ACROSS THE REGION BECOMES VERY
WEAK.
A WEAK MID LEVEL IMPULSE TRACKING FROM IOWA THIS AFTERNOON AND
ACROSS THE AREA AROUND THE WISCONSIN-ILLINOIS BORDER HAS THE
POTENTIAL TO GENERATE SOME PCPN...BUT FORECAST MOISTURE PROFILES
INDICATE CONDITIONS BELOW 5KFT SHOULD BE RATHER DRY AND A
SATURATED LAYER WITH WEAK FORCING LOOKS TO RATHER SHALLOW.
SO...WHILE THERE IS A SLIGHT CHANCE FOR RAIN OR A RAIN/SNOW
MIX...CHANCES ARE TOO LOW TO INCLUDE IN THE TAFS...AND MAY
ULTIMATELY END UP BEING MORE VIRGA THAN ACTUAL PCPN REACHING THE
GROUND.
FOR TOMORROW...WITH THE CENTER OF HIGH PRESSURE OVER SRN WISCONSIN
AND A DRY AIRMASS ACROSS THE REGION...EXPECT ONLY OPERATIONALLY
INSIGNIFICANT CLOUD COVER AND LIGHT NELY WINDS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* MEDIUM CONFIDENCE THAT THE TERMINALS WILL REMAIN DRY THROUGH
THE PERIOD.
* HIGH CONFIDENCE IN ALL OTHER FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF RAIN.
SATURDAY...RAIN SHOWERS LIKELY. CHANCE OF MVFR/IFR.
SUNDAY...VFR.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
WEDNESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
350 AM CST
HIGH WINDS AND WAVES CONTINUING ACROSS THE ENTIRE LAKE THIS
MORNING. THE STRONGEST WINDS ARE CURRENTLY OCCURRING OVER THE
NORTH HALF WHERE STORM FORCE WINDS ARE STILL ONGOING. THESE STORM
FORCE WINDS WILL CONTINUE THROUGH MID MORNING...WITH GALES
PERSISTING THEN INTO THE AFTERNOON. GALES ARE STILL OCCURRING
ACROSS THE SOUTH HALF/NEARSHORE...AND WITH THESE SPEEDS EXPECTED
TO CONTINUE THROUGH MID MORNING AS WELL. SPEEDS WILL CONTINUE TO
DIMINISH OVER THE ENTIRE LAKE THIS AFTERNOON AND THIS
EVENING...WITH A PERIOD OF LIGHTER WINDS TO END THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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
1023 AM CST THU DEC 24 2015
.UPDATE...
1023 AM...MORNING UPDATE...SHORT TERM/HI RES GUIDANCE SUGGESTING
WAVE OVER MISSOURI MAY BE SUFFICIENT FOR SOME SPRINKLES OR BRIEF
LIGHT RAIN ACROSS SOUTH/CENTRAL PARTS OF THE CWA THIS AFTERNOON
AND ADDED SLIGHT CHANCE MENTION OF THIS AFTERNOON. CLOUD COVER
ALSO EXPECTED TO FILL BACK IN WITH THIS WAVE AND THAT MAY KEEP
TEMPS FROM RISING MUCH BEYOND UPPER 30S NORTH TO MID 40S SOUTH.
A SECOND WAVE BACK OVER WESTERN IOWA WILL BE LIFTING NORTHEAST
THIS AFTERNOON AND THIS EVENING. 12Z NAM AND GFS SHOW THE BULK OF
THE PRECIP WITH THIS WAVE LIFTING NORTH OF THE CWA THIS EVENING.
THIS TREND ALSO SEEMS SUPPORTED BY THE RAP THOUGH THE HRRR STILL
MAINTAINS PRECIP INTO THE MID/LATE EVENING...MAINLY ACROSS FAR
NORTHWEST IL. ANY PRECIP THAT DOES OCCUR IS LIKELY TO BE LIGHT
AND WITH TEMPS PROBABLY STILL AT OR ABOVE FREEZING AT THAT
TIME...DOUBTFUL THERE WOULD BE ANY SNOW ACCUMULATION. CMS
&&
.SHORT TERM...
249 AM CST
THROUGH TONIGHT...
WINDS HAVE BEGUN TO CALM DOWN AFTER SEEING GUSTS EARLY THIS MORNING
OVER 40 MPH...BUT WITH SFC RIDGING ARRIVING THE GRADIENT WILL
CONTINUE TO DECREASE THROUGHOUT THE MORNING. BY MIDDAY WINDS SHOULD
BE GENERALLY SOUTHWEST BETWEEN 10 TO 20 MPH. THE LOW THAT BROUGHT
THE SEVERE WEATHER TO THE REGION HAS ALREADY LIFTED TO NEAR JAMES
BAY IN ONTARIO. DESPITE THE QUIET CONDITIONS FOR THE BULK OF THE
DAY...THE LARGEST CHALLENGE WILL BE ON HOW THE STRATUS LAYER
EVOLVES. IR IMAGERY SHOWS A LARGE STRATUS DECK SLIDING SOUTHEAST
ACROSS NORTHERN IL STRETCHING NORTHWEST THROUGH IOWA/MINNESOTA. HI-
RES GUIDANCE CONTINUES TO FEED CLOUDS ACROSS THE NORTHERN HALF OF
THE CWFA...WHICH COULD RESULT IN TEMPS BEING COOLER THEN PRESENT
HIGHS PROGGED AROUND 40 IN THE NORTHWEST AND LOW/MID 40S FOR
CENTRAL/SOUTHERN CWFA. DEW POINTS WILL BE HOVERING IN THE UPR 20S
DUE TO THE LACK OF STRONG SUBSIDENCE.
FURTHER UPSTREAM ACROSS THE CENTRAL ROCKIES IS A STRONGER MID-LVL
VORT...IR IMAGERY IS DEPICTING THIS FEATURE WELL AND MOST
OPERATIONAL SOLUTIONS HAVE THE TRAJECTORY OF THE MID-LVL WAVE
SLIDING EAST/NORTHEAST ACROSS IOWA INTO SOUTHERN WISC BY THIS
EVENING. THE CONCERN IS THAT IF THE STRATUS LAYER REMAINS IN PLACE
ACROSS THE FORECAST AREA...THE MID-LVL WAVE MAY ACT AS A CATALYST
AND QUICKLY SATURATE FROM TOP/DOWN THE PROFILE. WHILE THERE IS A
SHALLOW WARM LAYER...IT IS CONCEIVABLE THAT THIS COULD ERODE QUICKLY
IF DEW POINTS REMAIN IN THE UPR 20S/NEAR 30. IF INDEED THE WAVE
AGITATES THE ENVIRONMENT AND PRODUCES PRECIP...IT WOULD LIKELY FALL
AS RAIN AT THE ONSET...THEN THERMAL COOL DOWN TO SUPPORT A RAIN/SNOW
MIX BEFORE GOING OVER TO LIGHT SNOW AROUND 2-4Z. HAVE OPTED TO BLEND
MORE WITH THE SREF/GFS IN TIMING...BRINGING PRECIP INTO NORTHWEST
CWFA MID/LATE AFTN AND SPREADING EAST TOWARDS THE CHICAGO METRO BY
00-02Z. QPF LOOKS VERY LOW...BUT COULD EASILY SEE WHAT SNOW FALLS TO
PERHAPS PRODUCE A FEW TENTHS OF AN INCH BEFORE ENDING. SFC CONDS
SHOULD BE WARM ENOUGH TO LIMIT ANY ACCUMULATIONS...BUT IF THE MID-
LVL WAVE IS ABLE TO EFFICIENTLY PRODUCE MOISTURE THEN QPF COULD BE
HIGHER AS WELL AS PERHAPS UP TO ONE HALF INCH OF SNOW.
TEMPS OVERNIGHT SHOULD COOL OFF INTO THE UPR 20S IN THE NORTH...BUT
REMAIN IN THE LOW TO PERHAPS MID 30S IN THE FAR SOUTH.
BEACHLER
&&
.LONG TERM...
249 AM CST
FRIDAY THROUGH WEDNESDAY...
CHRISTMAS DAY THROUGH SATURDAY... SFC RIDGING THEN ABSORBS THE
REMAINING LOW LEVEL MOISTURE EARLY CHRISTMAS DAY WITH DRY CONDS AND
P-CLOUDY SKIES EXPECTED FOR MUCH OF THE DAY. WITH THE LACK OF COLD
AIR IN PLACE...TEMPS WILL LIKELY REBOUND INTO THE MID/UPR 40S. ONE
CAVEAT IS THAT WINDS WILL BE TURNING NORTHEAST...WHICH COULD KEEP
THE AREAS ADJACENT TO LAKE MICHIGAN A FEW DEGREES COOLER. BY
CHRISTMAS NIGHT OPERATIONAL GUIDANCE CONTINUES TO PROG A DEVELOPING
SHORTWAVE ACROSS THE LEE-SIDE OF THE SOUTHERN ROCKIES. WITH THE
500MB TROUGH PARKED ACROSS THE FOUR-CORNERS REGION OF THE
CONUS...SOUTHERLY FLOW OF MOISTURE APPEARS POISED TO STREAM NORTH
FROM THE WESTERN GULF. SO TEMPS MAY ONLY FALL SLIGHTLY CHRISTMAS
NIGHT BEFORE WARMING OVERNIGHT. PRECIP SHOULD OVERSPREAD THE REGION
BY EARLY SATURDAY...AND BE WARM ENOUGH INITIALLY TO SUPPORT RAIN.
UNSEASONABLY WARM/MOIST CONDITIONS CONTINUE INTO SAT...WITH DEW
POINTS YET AGAIN PUSHING INTO THE LOW 50S IN THE FAR SOUTHERN CWFA.
GUIDANCE CONTINUES TO INDICATE SOME MID-LVL INSTABILITY WITH A
SERIES OF WEAK SHORTWAVES LIFTING NORTHEAST ALONG A QUASI-STATIONARY
BOUNDARY...SO HAVE HELD ONTO THE MENTION OF THUNDER IN THE SOUTH.
SUNDAY THROUGH WEDNESDAY... FOR THE SECOND HALF OF THE WEEKEND
OPERATIONAL GUIDANCE HAS BEEN BOUNCEING BETWEEN THE PLACEMENT OF THE
FRONTAL BOUNDARY...BUT NOW APPEARS FAVORABLE TO PUSH SOUTH OF THE
FORECAST AREA BY SUN MIDDAY WITH A STRONG CANADIAN SFC RIDGE
DROPPING SOUTH INTO THE NORTHERN PLAINS EARLY SUN...THEN STRETCHING
EAST SUN NGT TO COVER MUCH OF THE GREAT LAKES AND PUSH THE BOUNDARY
FURTHER SOUTH. ENSEMBLES CONTINUE TO SHOW THAT THE SFC RIDGE MAY BE
STRONG ENOUGH TO HOLD THE FRONTAL BOUNDARY FURTHER SOUTH INTO
MONDAY...WHICH MAY FURTHER DELAY MOISTURE FROM LIFTING BACK ACROSS
THE REGION UNTIL MON NGT/TUE.
MID-LVL FLOW DOES BEGIN TO TRANSITION TOWARDS A SEMI-ZONAL SETUP
MON...WHICH COULD AID IN EJECTING THE SFC RIDGE BACK EAST EARLIER
MON AND ALLOW THE BOUNDARY AND DEVELOPING SHORTWAVE TO QUICKLY LIFT
NORTH DURING THE DAY MON. IT IS POSSIBLE THAT THE NORTHERN EDGE OF
THE PRECIP SHIELD...ONCE IT DOES RETURN NORTH...COULD START AS A
WINTRY MIX BEFORE WARMING AND TRANSITIONING OVER TO ALL RAIN. BUT
GIVEN THE LOW CONFIDENCE IN THE PRECISE PLACEMENT OF THE
LOW/BOUNDARY...THIS PERIOD WILL LIKELY UNDERGO ADDITIONAL CHANGES.
TEMPS TOWARDS NEXT WEEK APPEAR TO LEAN TOWARDS CLIMO WITH HIGHS IN
THE LOW/MID 30S...BUT LOWS WILL LIKELY SEE SOME MODERATION GIVEN
EXPECTED CLOUD COVER AND REMAIN IN THE MID/UPR 20S TO AROUND 30.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* GUSTY WEST/SOUTHWEST WINDS THIS MORNING.
* LOW POTENTIAL FOR LIGHT RAIN/SNOW EARLY THIS EVENING.
KREIN
//DISCUSSION...UPDATED 12Z...
GUSTY WESTERLY WINDS PERSISTING THIS MORNING AND WILL LIKELY
CONTINUE OVER THE NEXT SEVERAL HOURS...BUT WITH SPEEDS THEN
EXPECTED TO DIMINISH INTO THE AFTERNOON. WINDS WILL LIKELY BECOME
VARIABLE THIS AFTERNOON INTO THE EVENING BEFORE HOLDING ONTO A
MORE NORTHERLY DIRECTION...BUT STILL LIGHT. MVFR CEILINGS WILL BE
LIKELY THROUGH THE DAY. HOWEVER...THE TERMINALS ARE RIGHT ON THE
EDGE OF THIS CLOUD SHIELD AT THIS TIME. ALTHOUGH THERE MAY SOME
BRIEF PERIODS OF CLEARER SKIES EARLY...THE TREND WILL BE TO CLOUD
BACK UP LATER THIS MORNING. STILL MONITORING THE POTENTIAL FOR
SOME LIGHT PRECIP ACROSS THE AREA LATER THIS AFTERNOON INTO THE
EVENING. CONFIDENCE IS LOW WITH COVERAGE AND PLACEMENT AND HAVE
ONLY MADE MENTION OF VCSH IN THE TAFS. IF THIS WERE TO
DEVELOP...HIGHEST CHANCES WOULD BE NEAR THE RFD/DPA AREA. PRECIP
TYPE COULD ALSO BE A CHALLENGE...AS ITS POSSIBLE THAT RAIN/SNOW
MIX COULD BE OBSERVED.
RODRIGUEZ
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* HIGH WITH WIND SPEED/DIRECTION.
* MEDIUM TO HIGH WITH CEILING TRENDS.
* LOW WITH PCPN POTENTIAL LATER THIS EVENING.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...SLIGHT CHANCE OF RAIN.
SATURDAY...RAIN SHOWERS LIKELY. CHANCE OF MVFR/IFR.
SUNDAY...VFR.
MONDAY...CHANCE OF RAIN/SNOW/SLEET AND MVFR CIGS.
TUESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
WEDNESDAY...CHANCE OF RAIN/SNOW AND MVFR CIGS.
RODRIGUEZ
&&
.MARINE...
350 AM CST
HIGH WINDS AND WAVES CONTINUING ACROSS THE ENTIRE LAKE THIS
MORNING. THE STRONGEST WINDS ARE CURRENTLY OCCURRING OVER THE
NORTH HALF WHERE STORM FORCE WINDS ARE STILL ONGOING. THESE STORM
FORCE WINDS WILL CONTINUE THROUGH MID MORNING...WITH GALES
PERSISTING THEN INTO THE AFTERNOON. GALES ARE STILL OCCURRING
ACROSS THE SOUTH HALF/NEARSHORE...AND WITH THESE SPEEDS EXPECTED
TO CONTINUE THROUGH MID MORNING AS WELL. SPEEDS WILL CONTINUE TO
DIMINISH OVER THE ENTIRE LAKE THIS AFTERNOON AND THIS
EVENING...WITH A PERIOD OF LIGHTER WINDS TO END THE WORK WEEK.
RODRIGUEZ
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
IN...NONE.
LM...NONE.
&&
$$
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 JACKSON KY
320 PM EST THU DEC 24 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM EST THU DEC 24 2015
19Z SFC ANALYSIS SHOWS A RELATIVE AREA OF HIGH PRESSURE OVER THE
OHIO VALLEY WHILE LOW PRESSURE IS BUILDING TO THE SOUTHWEST. ON
SATELLITE...A BRIEF PERIOD OF LOW CLOUDS AROUND MIDDAY HAVE
BROKEN UP AND SCATTERED OUT DURING THE EARLY AFTERNOON LEAVING
MOSTLY SUNNY CONDITIONS. THAT SUNSHINE...AND SOME LIMITED
DRYING...RESULTED IN TEMPERATURES SPIKING INTO THE UPPER 60S AND
LOWER 70S THROUGH EAST KENTUCKY THIS AFTERNOON. DEWPOINTS HAVE
FALLEN INTO THE LOW AND MID 50S..BUT ARE STILL VERY HIGH FOR THIS
TIME OF YEAR. MEANWHILE...WINDS ARE LIGHT AND VARIABLE THROUGH THE
AREA...GENERALLY FROM THE SOUTH FOR LOCATIONS SOUTH OF THE
MOUNTAIN PARKWAY.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE LONGWAVE PATTERN
AS THEY ALL SHOW THE SOUTHEAST RIDGE STRENGTHENING AND WOBBLING
WEST INTO FRIDAY WHILE LARGE AND FAIRLY STRONG TROUGHING DIVES
INTO THE DESERT SOUTHWEST. THIS WILL ALL SERVE TO STRENGTHEN THE
BROAD AND DEEP SOUTHWEST FLOW THROUGH THE REGION INTO SATURDAY
MORNING. WHILE THE MAJORITY OF THE ENERGY IN THIS PATTERN WILL
STAY WITH THE WESTERN TROUGH...THERE WILL BE A FEW WEAK WAVES THAT
RIDE OVER THE AREA DURING THE SHORT TERM PORTION OF THE FORECAST.
OF MOST SIGNIFICANCE WILL BE THE RECORD OR NEAR RECORD HIGH PW
AIR IN PLACE OVER THE REGION DURING THE DAY FRIDAY INTO
SATURDAY...THAT THE MODELS ARE PRETTY MUCH IN CONCURRENCE WITH.
AS SUCH...WILL FOLLOW A BLENDED MODEL SOLUTION FAVORING THE HIGHER
RESOLUTION HRRR AND NAM12 ALONG WITH INPUT FROM THE NATIONAL
CENTERS.
SENSIBLE WEATHER WILL FEATURE A CONTINUATION OF OUR VERY WARM
HOLIDAY PERIOD WITH TEMPERATURES NOT FALLING TOO FAR INTO THE 50S
FOR MOST SPOTS TONIGHT. ALTHOUGH...AM EXPECTING A BIT OF A RIDGE
TO VALLEY TEMPERATURE SPLIT THIS EVENING AND INTO THE FIRST PART
OF THE OVERNIGHT. THIS SHOULD BE MOST NOTICEABLE IN THE FAR
EASTERN SHELTERED VALLEYS AND IS EXPECTED TO MIX OUT TOWARDS DAWN.
THE NEXT SURGE IN PCPN WILL LIKELY MOVE IN FROM THE SOUTHWEST
AROUND DAWN AS WELL AND OVERSPREAD THE ENTIRE CWA BY MID MORNING.
EXPECT LIGHT TO MODERATE SHOWERS ALONG WITH A POTENTIAL FOR
THUNDERSTORMS INTO THE DAY FRIDAY AS AN INVERTED TROUGH/SFC WAVE
MOVES THROUGH KENTUCKY. THIS WILL ACTIVATE THE HIGH MOISTURE
CONTENT IN PLACE AND COULD LEAD TO TRAINING ISSUES IN A FEW
SPOTS...PARTICULARLY THOSE THAT MAY HAVE SEEN SATURATING TO HEAVY
RAINS OVER THE PAST DAY OR SO. DO EXPECT THE HIGHEST RAINFALL
TOTALS THROUGH SATURDAY MORNING TO FALL OVER THE CUMBERLAND
VALLEY BEFORE THE RESPONSIBLE WAVE PULLS OUT OF THE AREA EARLY
SATURDAY. GIVEN THE POTENTIAL HAVE DECIDED TO ISSUE A FLOOD WATCH
STARTING AT 6 AM FRIDAY AND RUNNING THROUGH 8 AM SATURDAY...WITH
BETWEEN 1.5 AND 2.5 INCHES OF RAIN POSSIBLE DURING THIS TIME
FRAME. THIS WATCH WILL COVER POINTS GENERALLY SOUTH OF INTERSTATE
64. CONFIDENCE IS FAIRLY HIGH THAT A GOOD SWATH OF RAIN WILL FALL
OVER A GOOD PORTION OF THE CWA DURING THIS TIME...BUT LOW FOR ANY
PARTICULAR PLACEMENT GIVEN SOME DISCREPANCIES WITH THE HIGHEST
AXIS OF QPF FROM EACH MODEL. IN ADDITION...THE CONCERN FOR HEAVY
RAIN WILL RUN INTO THE NEW WEEK AND FOR THAT OVERARCHING RAINFALL
THREAT WILL ISSUE AN ESF.
FOR TEMPERATURES AND DEWPOINTS...HAVE MAINLY GONE WITH THE
SHORTBLEND GUIDANCE THROUGH FRIDAY MORNING AND THEN THE SUPERBLEND
INTO SATURDAY MORNING. DID MAKE SOME NEAR TERM ADJUSTMENTS INTO
THE FIRST PART OF THE NIGHT FOR A PARTIAL AND BRIEF RIDGE TO
VALLEY TEMPERATURE SPLIT. NOT EXPECTING MUCH OF A DIFFERENCE IN
TEMPS FRIDAY NIGHT GIVEN THE PCPN. AS FOR POPS...ENDED UP ON THE
HIGH SIDE OF GUIDANCE THROUGH THE PERIOD...ESPECIALLY TONIGHT AT
LOZ WHERE THE WETTER MET NUMBERS WERE PREFERRED.
WHILE RECORD HIGH MINIMUM TEMPERATURES ARE EXPECTED BOTH TONIGHT
AND FRIDAY NIGHT...HIGH TEMPERATURE RECORDS FOR TOMORROW WILL
LIKELY NOT FALL DUE TO A VERY WARM CHRISTMAS BACK IN 1982.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 315 PM EST THU DEC 24 2015
THE MAIN CONCERN FOR THIS PERIOD WILL BE THE POTENTIAL FOR
REPEATING ROUNDS OF RAINFALL THROUGH EARLY NEXT WEEK WITH A DEEP
AND MOISTURE LADEN SOUTHWEST FLOW IN PLACE ALOFT. A WAVY FRONTAL
BOUNDARY WILL LIFT NORTHWARD ACROSS OUR AREA ON SATURDAY ALLOWING
FOR A BREAK IN THE RAINFALL FOR MOST OF EASTERN KENTUCKY FROM
SATURDAY AFTERNOON THROUGH SUNDAY MORNING. FOR THIS REASON...THE
FLOOD WATCH ISSUED WILL ONLY RUN THROUGH AROUND DAWN ON SATURDAY.
HOWEVER...DEEPENING LOW PRESSURE WILL DRIVE NORTHEASTWARD OUT OF
TEXAS LATE IN THE WEEKEND INTO THE DAY ON MONDAY AND THIS WILL
SEND THE FRONT AND A LOAD OF MOISTURE BACK ACROSS THE REGION
BEGINNING SUNDAY AFTERNOON AND LASTING THROUGH MONDAY NIGHT. A
COUPLE OF INCHES OF ADDITIONAL RAINFALL IS LIKELY DURING THIS SECOND
WAVE OF RAIN...WHICH WILL LIKELY CAUSE ADDITIONAL FLOOD CONCERNS.
THIS SYSTEM WILL EXIT TO OUR EAST WITH DIMINISHING RAIN CHANCES ON
TUESDAY.
THE OTHER STORY TO TOUCH ON IS THE UNSEASONABLE WARMTH. PROGGED
850 MB TEMPS ON SATURDAY OF AROUND 15C ARE CLOSE TO RECORD HIGHS
ACCORDING TO SPC SOUNDING CLIMATOLOGY. HIGH TEMPS ARE FORECAST TO
EASILY ECLIPSE RECORDS SATURDAY BY CLIMBING INTO THE LOW TO MID
70S. THIS MAY BE CONSERVATIVE IF CLOUDS SCATTER OUT FOR ANY LENGTH
OF TIME. TEMPS ON SUNDAY WILL AGAIN THREATEN RECORDS AS THEY CLIMB
TO AROUND 70 SOUTH OF I-64...BEFORE A COOLER BUT STILL ABOVE NORMAL
AIRMASS FILTERS IN BEHIND THE FRONT FOR THE MIDDLE OF NEXT WEEK. IF
OUR FORECAST PANS OUT THROUGH DECEMBER 31ST...THIS WILL EASILY BE
THE WARMEST DECEMBER ON RECORD AT BOTH JKL AND LOZ. IN FACT...OUR
AVERAGE TEMPERATURE THIS DECEMBER AT JKL AND LOZ WILL LIKELY BE A
COUPLE DEGREES WARMER THAN THE AVERAGE NOVEMBER TEMPERATURE AT
THOSE SITES WHEN ALL IS SAID AND DONE!
BEYOND TUESDAY...FORECAST MODELS KEEP US IN SOUTHWEST FLOW ALOFT
WITH ANOTHER SHORTWAVE PROGGED TO BRING ANOTHER ROUND OF SHOWERS
WEDNESDAY AND WEDNESDAY NIGHT...FOLLOWED BY A RETURN TO MORE
SEASONAL TEMPERATURES BY NEW YEARS EVE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 115 PM EST THU DEC 24 2015
MAINLY VFR CEILINGS WILL PREVAIL INTO THE FIRST PART OF THE NIGHT
THEN LOWER DOWN TO MVFR TOWARD DAWN FRIDAY AND INTO OR NEAR IFR
THROUGH THE END OF THE PERIOD. SHOWERS AND A FEW RUMBLES OF
THUNDER WILL BE MOVING BACK IN AROUND DAWN IN THE SOUTHWEST AND BY
13Z ELSEWHERE. WINDS WILL AVERAGE AROUND 5 KTS OR LESS THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
FLOOD WATCH FROM FRIDAY MORNING THROUGH SATURDAY MORNING FOR
KYZ058>060-068-069-079-080-083>088-104-106>120.
&&
$$
SHORT TERM...GREIF
LONG TERM...ABE
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
130 PM EST THU DEC 24 2015
.UPDATE...
ISSUED AT 130 PM EST THU DEC 24 2015
DID A QUICK UPDATE TO THE GRIDS TO CAPTURE THE CURRENT CONDITIONS
INCLUDING SKY COVER THROUGH THE REST OF THE DAY. THESE GRIDS HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1045 AM EST THU DEC 24 2015
15Z SFC ANALYSIS SHOWS A WEAK AND FLEETING AREA OF HIGH PRESSURE
MOVING OVER THE LOWER OHIO VALLEY IN THE WAKE OF A LOW PRESSURE
WAVE DEPARTING TO THE EAST. THIS WAVE PULLED THE LAST OF THE
SHOWERS OUT OF THE AREA AROUND DAWN AND HAS ALSO TAKEN THE BULK OF
THE LOW AND MID LEVEL CLOUDS OUT AS WELL. TEMPERATURES THROUGH
EAST KENTUCKY STARTED OUT WARM AND HAVE BASICALLY HELD STEADY AS
THE INSOLATION IS COUNTERING THE LIMITED CAA IN THE WAKE OF THE
LOW. NORTHWEST PARTS OF THE AREA HAVE MANAGED TO SETTLE INTO THE
UPPER 50S WHILE THE REST OF THE AREA IS GENERALLY IN THE LOW 60S.
EXPECT A REBOUND TO THE NORTHWEST TEMPS BY MID AFTERNOON WHILE THE
THERMOMETERS OF THE REST OF EASTERN KENTUCKY CREEP UP TOWARD THE
MID AND UPPER 60S. SOME DRIER AIR IS INBOUND WITH THE HIGH
PRESSURE AS WELL AND READINGS CURRENTLY REFLECT THAT...VARYING
FROM THE UPPER 40S IN THE NORTHWEST TO THE UPPER 50S AND LOW 60S
IN THE SOUTHEAST TWO THIRDS OF THE CWA. WINDS HAVE TURNED TO THE
NORTHWEST FOR MUCH OF EASTERN KENTUCKY...BUT ARE STILL CALM OR
SOUTHWEST NEARER TO WEST VIRGINIA AND VIRGINIA. HAVE UPDATED THE
FORECAST TO REFLECT LESS SKY COVER AND NEAR ZERO POPS THROUGH THE
REST OF THE DAY ALONG WITH ADDING IN THE LATEST SHORTBLEND
GUIDANCE FOR THE T AND TD GRIDS. THESE HAVE BEEN FINALIZED WITH
THE CURRENT OBS AND TRENDS. THE UPDATED GRIDS HAVE BEEN SENT TO
THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 757 AM EST THU DEC 24 2015
PRECIPITATION HAS EXITED THE AREA...AND THE LATEST HRRR HAS BEEN
SHOWING NO OTHER ACTIVITY FOR THE REST OF THE DAY. THIS SEEMS
REASONABLE GIVEN THE LACK OF FORCING. AS SUCH...HAVE REMOVED POPS
FOR THE REST OF THE DAY. ALSO FRESHENED UP THE HOURLY TEMPERATURES
AND DEW POINTS BASED ON THE LATEST TRENDS IN OBSERVATIONS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
A SURFACE COLD FRONT...STEMMING FROM DEEP LOW PRESSURE CENTERED
ACROSS SOUTH CENTRAL ONTARIO...IS ALIGNED FROM EASTERN INDIANA
DOWN ACROSS CENTRAL KENTUCKY. CONVECTION HAS RACED WELL OUT AHEAD
OF THE BOUNDARY...BEING SUSTAINED BY A STOUT LOW LEVEL JET. THE
WIDESPREAD ACTIVITY HAS ALL BUT CLEARED FAR SOUTHEASTERN
KENTUCKY...WITH JUST A FEW SHOWERS LINGERING BEHIND THE MAIN LINE.
CURRENT OVERNIGHT TEMPERATURES ARE STILL RUNNING WELL ABOVE THE
NORMAL DAYTIME HIGHS FOR THIS TIME OF YEAR...WITH READINGS
RANGING FROM THE UPPER 50S TO LOWER 60S. ALOFT...DEEP TROUGHING
RULES ACROSS THE WESTERN TWO THIRDS OF THE NATION...WITH A MORE
SUMMER-LIKE HIGH POSITIONED ACROSS THE WESTERN ATLANTIC.
THE MODELS ARE IN GOOD AGREEMENT THROUGH THE SHORT TERM.
CONVECTION WILL CONTINUE TO WANE ACROSS OUR AREA...AS THE LOW
LEVEL JET DIMINISHES AND THE SURFACE COLD FRONT GETS SHEARED
OUT. PASSING HIGH PRESSURE TO OUR NORTH WILL KEEP THINGS DRY
THROUGH MOST OF TONIGHT. MEANWHILE...THE NEXT BIG CHUNK OF ENERGY
WILL BE DIGGING IN FROM THE EASTERN PACIFIC. THIS WILL ALLOW AN
INVERTED SURFACE TROUGH TO DEVELOP AND NOSE IN FROM THE SOUTHWEST
BY EARLY CHRISTMAS DAY...WITH ANOTHER ROUND OF WIDESPREAD SHOWERS
AND A FEW THUNDERSTORMS POSSIBLE.
THE MODELS HAVE BEEN VARYING WITH THE AMOUNT AND POSITION OF THE
HEAVIER QPF...WITH THE ECMWF AND NAM BEEFIER...WHILE THE GFS HAS
BEEN LEANER. GIVEN THE FACT THAT THERE IS WEAK MID AND UPPER LEVEL
FORCING...AM INCLINED TO PUT MORE CONFIDENCE IN THE LEANER TOTALS
FOR NOW. STILL...PWATS ARE EXTREMELY HIGH AND ANY TRAINING
THUNDERSTORM ACTIVITY COULD CERTAINLY BRING TOTALS MORE TOWARDS
THE HIGHER END...UPWARDS OF 2 INCHES IN A 6 TO 12 HOUR PERIOD.
CONSEQUENTLY...WILL CONTINUE TO MENTION GENERALIZED FLOODING
CONCERNS IN THE HWO.
FOR TEMPERATURES...A MORE DIURNALLY LIMITED REGIME WAS
FAVORED...GIVEN THE CLOUDS AND QUICK RETURN OF PRECIPITATION BY
CHRISTMAS DAY. HIGHS TODAY WILL RANGE FROM THE MID TO UPPER
60S...WITH READINGS MORE IN THE LOW TO MID 60S FOR THE HOLIDAY.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 359 AM EST THU DEC 24 2015
MODELS ARE IN GENERALLY GOOD AGREEMENT ON THE MILD AND WET PATTERN
PERSISTING THROUGH THE WEEKEND INTO NEXT WEEK. IT DOES LOOK LIKE THE
WARM FRONT SHOULD LIFT NORTH FRIDAY NIGHT INTO EARLY SATURDAY WITH
RAIN CHANCES LIFTING NORTH OF THE AREA. THUS...MUCH OF SATURDAY
COULD END UP ON THE DRIER SIDE (WHICH WOULD NOT BE A BAD THING). IF
THE DRIER FORECAST PANS OUT...TEMPERATURES COULD SOAR INTO THE LOW
TO MID 70S SOUTH OF THE WARM FRONT...SETTING UP ANOTHER RECORD
BREAKING DAY. IF CLOUDS HOLD ON OR PRECIPITATION HOLDS ON
LONGER...WE MIGHT HAVE TO SETTLE FOR READINGS CLOSER TO 70...BUT
STILL MILD. PRECIPITATION STAYS NORTH INTO SATURDAY NIGHT...BUT THE
FRONT WILL BE DRIVEN BACK TO THE SOUTH ON SUNDAY WITH RAIN CHANCES
RAMPING BACK UP. THE FRONT WILL THEN STALL IN OUR VICINITY KEEPING
THE WEATHER UNSETTLED INTO MONDAY. FINALLY A COLD FRONT SHOULD SWEEP
ACROSS THE AREA MONDAY NIGHT/TUESDAY...BRINGING AN END TO THE
EXTENDED PERIOD OF WET AND MILD WEATHER. TEMPERATURES WILL TAKE A
HIT BY WEDNESDAY WITH HIGHS BACK INTO THE LOWER 50S (BUT STILL ABOVE
NORMAL!). A SECONDARY COLD FRONT COULD BRING A BETTER SURGE OF
COLDER AIR AS WE HEAD INTO NEW YEARS EVE...BRINGING A RETURN OF
MORE SEASONABLE WINTER WEATHER TO EASTERN KENTUCKY.
FORTUNATELY...DESPITE IT TURNING COLDER NEXT WEEK...STILL NO SIGNS
OF ANY SNOWFALL FOR OUR NECK OF THE WOODS.
WITH ALL THE RAIN EXPECTED ON FRIDAY/FRIDAY NIGHT...COUPLED WITH THE
RAIN SUNDAY INTO TUESDAY...WE WILL CONTINUE TO HAVE TO MONITOR
CONDITIONS FOR POSSIBLE FLOODING...ESPECIALLY ON THE RIVERS AND
CREEKS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 115 PM EST THU DEC 24 2015
MAINLY VFR CEILINGS WILL PREVAIL INTO THE FIRST PART OF THE NIGHT
THEN LOWER DOWN TO MVFR TOWARD DAWN FRIDAY AND INTO OR NEAR IFR
THROUGH THE END OF THE PERIOD. SHOWERS AND A FEW RUMBLES OF
THUNDER WILL BE MOVING BACK IN AROUND DAWN IN THE SOUTHWEST AND BY
13Z ELSEWHERE. WINDS WILL AVERAGE AROUND 5 KTS OR LESS THROUGH THE
PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GEOGERIAN
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
1124 AM EST THU DEC 24 2015
.SYNOPSIS...
A WARM FRONT WILL MOVE THROUGH THE AREA THIS AFTERNOON WITH
STRONG WARM AIR ADVECTION. THIS WILL SET THE STAGE FOR SEVERAL
RECORD HIGH TEMPERATURES TO BE BROKEN...ESPECIALLY ACROSS SOUTHERN
NEW HAMPSHIRE AND EXTREME SOUTHWEST MAINE. A WEAK COLD FRONT MOVES
ACROSS THE AREA TONIGHT WITH CLEARING CONDITIONS AND COOLER
TEMPERATURES. TEMPERATURES WILL STILL REMAIN WELL ABOVE NORMAL FOR
TONIGHT AND CHRISTMAS DAY. OUR NEXT STORM SYSTEM LOOKS TO ARRIVE
LATE SATURDAY INTO SUNDAY AND SHOULD BE MOSTLY IN THE FORM OF RAIN
ONCE AGAIN. HOWEVER...COLDER AIR WILL PUSH INTO THE REGION THE
BEGINNING OF NEXT WEEK AND COULD REMAIN IN PLACE LONG ENOUGH FOR
SEVERAL LOCATIONS TO SEE THEIR FIRST MEASURABLE SNOWFALL OF THE
SEASON TUESDAY INTO WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1120 AM UPDATE...
WARM FRONT HAS PUSHED INLAND A WAYS...BRINGING PATCHY FOG AND
DRIZZLE WITH IT. TO THE WEST A QLCS HAD DEVELOPED ALONG A COLD
FRONT WITH SOME SHOWERS OUT AHEAD OF IT. THE FRONT LOOKS NOW TO
CROSS THE AREA EARLY THIS EVENING WITH LITTLE FANFARE.
TEMPERATURES WILL CONTINUE TO BE TRICKY WITH POSSIBLE RAPID
WARMING TOWARDS THE END OF THE DAY ONCE THE INVERSION BREAKS.
9 AM UPDATE...
DIURNAL CURVE REMAINS A CHALLENGE WITH WARM FRONT SNAKING THROUGH
THE REGION AND ALONG THE COAST. PLENTY OF MOISTURE IS POOLING IN
THE WARM SECTOR WITH TEMPERATURES IN OUR AREA IN THE LOW TO MID
40S. FARTHER SOUTH FROM ALBANY TO CAPE COD READINGS ARE IN THE LOW
60S. AS THE WARM FRONT LIFTS NORTH AND EAST WE WILL SEE THAT
WARMTH SPREAD NORTH AND EAST...HOWEVER IT MAY TAKE MOST OF THE
DAY FOR PORTIONS OF THE AREA. IN FACT IT MAY BE AFTER SUNSET THAT
SOME LOCATIONS REACH THEIR HIGHS...INCLUDING PORTLAND.
MANCHESTER AND NASHUA SHOULD REACH THEM MUCH SOONER.
A STRONG AND SHALLOW INVERSION IS NOTED ON THIS MORNING`S
SOUNDING AND IS RESPONSIBLE FOR KEEPING THE WARMER TEMPERATURES
JUST ALOFT. FOR INSTANCE MT WASHINGTON ALREADY BROKE THEIR
TEMPERATURE RECORD FOR THE DAY.
WENT CLOSE TO THE 11Z HRRR FOR THE DIURNAL CURVE WHICH HAS A
BETTER HANDLE ON THE TEMPERATURES THAN THE LATER RUNS AND THE
LOCAL WRF. DRIZZLE/FOG CONTINUES FOR A FEW MORE HOURS UNTIL THE
INVERSION CAN BE BROKEN/ERODED. THERE IS A STRONG LLJ (45 KT)
JUST OFF THE DECK AT AROUND FL025 KFT.
SOME FUN CHRISTMAS EVE WEATHER TRIVIA...THIS MORNING`S KGYX
SOUNDING HAD +13 DEGREES C AT 850MB TEMPERATURE...WHICH IS OUR
SECOND ALL TIME HIGHEST 850MB TEMPERATURE FOR DECEMBER. GOING UP
TO 700MB WE ARE +9 C WHICH IS THE HIGHEST EVER RECORDED FOR
NOVEMBER OR DECEMBER. FOR INSTANCE...KEY WEST`S SOUNDING THIS
MORNING WAS ONLY ONE DEGREE HIGHER (+10) AT 700MB THAN WE ARE!
PREVIOUS DISCUSSION...
WITH THE RAIN ENDING BY MORNING AS THE WARM FRONT ALOFT PASSES TO
OUR N...THE NEXT PROBLEM WILL BE DEALING WITH THE SHARP INVERSIONS
OVER THE AREA THAT BUFKIT SHOWS REMAINING IN PLACE AT ALL
LOCATIONS INTO THE EARLY AFTERNOON. THE SURFACE ANALYSIS ALREADY
SHOWS NICE LOW LEVEL DAMMING OCCURRING WITH NOSING OF HIGH
PRESSURE EXTENDING SOUTHWEST ACROSS ME AND NH. MODELS ARE ALL IN
AGREEMENT THE LOW LEVEL SOUTHWEST JET WILL BE RIDING OVER THIS
SHALLOW INVERSION INTO THE AFTERNOON. WITH THE LACK OF VENTILATION
OF ALL THE RESIDUAL MOISTURE COMBINING WITH STRONG WAA ABOVE THE
SURFACE..WILL EXPECT SUPERSATURATION OF THE AIR MASS TO REMAIN AND
FOG AND DRIZZLE TO REFORM IN THE MORNING...THE QUESTION WILL BE
HOW LOW VISIBILITIES WILL GO. THE DAY SHIFT WILL HAVE TO WATCH FOR
A POSSIBLE NEED OF A DENSE FOG ADVISORY IN SOME AREAS FOR A WHILE
INTO EARLY AFTERNOON. STILL CONFIDENT TEMPERATURES ARE EXPECTED TO
REACH RECORD HIGHS OVER SOUTHERN NH AND SOUTHWEST ME BUT WILL NOT
BE REALIZED UNTIL MID- LATE AFTERNOON AS THE INVERSIONS BREAK AND
A SUDDEN JUMP IN TEMPS WILL BE NOTED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
A WEAK COLD FRONT WITH NOT MUCH COLD AIR IN ITS WAKE MOVES
THROUGH THE REGION TONIGHT ALLOWING CLEARING SKIES TO OCCUR AND
TEMPS TO COOL. EVEN STILL TEMPS WILL REMAIN WELL ABOVE NORMAL
TONIGHT AND CHRISTMAS DAY. USED A BLEND OF MODELS FOR MIN/MAX TEMP
FORECAST TONIGHT AND FRI.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRES SLIDES EWD THRU THE REGION FRI NIGHT. LOW TEMPS WILL
DEPEND ON THE AMOUNT OF CLOUD COVER THAT CAN MAKE IT INTO SRN
ZONES. EXPECT THAT MOST OF SAT WILL BE DRY...UNTIL THE EVE. S/WV
TROF MOVING THRU THE GREAT LAKES WILL INDUCE A WEAK LOW TO FORM
ALONG THE STALLED FRONTAL BOUNDARY TO OUR S. THIS WAVE WILL SPREAD
PRECIP INTO THE AREA FROM THE W SAT NIGHT. THERE IS NOT A LOT OF
COLD AIR AROUND FOR THIS SYSTEM...BUT DRY AIR ALOFT MAY ALLOW FOR
ENOUGH WET BULB COOLING TO BRING A MIX OR SNWFL INTO NRN ZONES.
WILL USE A TOP DOWN APPROACH TO PRECIP TYPE IN THOSE AREAS...TO
INTRODUCE A LITTLE WINTRY MIX. THIS IS STILL NEARLY 4 DAYS
OUT...SO DETAILS CAN CHANGE...BUT A LIGHT SNWFL IS POSSIBLE FOR
THE FAR N NEAR JACKMAN...WHILE THRU THE MTNS A LIGHT FREEZING RA
IS POSSIBLE.
BEHIND THIS SYSTEM...A SECONDARY S/WV WILL DRIVE A STRONG COLD
FRONT THRU THE REGION. FOR WHAT SEEMS LIKE THE FIRST TIME IN A
LONG WHILE MODEL GUIDANCE IS INDICATING A SEASONABLY COLD AIR
MASS. THAT/S RIGHT...BELOW NORMAL TEMPS ALOFT. SFC HIGH PRES THAT
BUILDS IN WITH THESE TEMPS IS ALSO FORECAST TO BE QUITE STRONG ON
BOTH GEFS AND ECMWF EPS. MODEL TIMING IS IN EXCELLENT AGREEMENT
FOR THIS RANGE...ARRIVING AROUND 18Z TUE...SO I HAVE NO PROBLEM
GOING WITH LIKELY POP. WITHOUT GETTING INTO TOO MUCH DETAIL FOR
DAY 6...CAREFUL EXAMINATION OF TEMP TRENDS ALOFT SHOW A PRETTY
CLASSIC SIGNAL FOR SNWFL TO MIX FOR A LARGE PART OF THE REGION.
HIGH HEIGHTS IN THE E IS THE TENDENCY STILL IN THE MID
LEVELS...AND THAT WILL WANT TO SEND ANY SYSTEM TO OUR W. THE
RESULTING WAA OVERHEAD WILL BRING IN WARMTH FROM THE SW. ALL MODEL
GUIDANCE SHOWS THIS EVOLUTION...WITH THE GFS AND ECMWF IN CLOSER
AGREEMENT THAN THE COLDER CMC. AGAIN...THIS SYSTEM IS TOO FAR OUT
TO START HAMMERING OUT EXACT SNWFL AMOUNTS...BUT THE CHANCES FOR A
MEASURABLE SNWFL ARE GROWING AND BECOMING MORE LIKELY. ANOTHER 24
HOURS AND THIS SYSTEM WILL BE CLOSER TO THE RANGE WHERE MEDIUM
RANGE GUIDANCE HISTORICALLY STARTS TO PERFORM WELL.
ONE THING THAT IS HIGHER CONFIDENCE IS THAT WITH STRONG HIGH PRES
AND PRECIP MOVING IN...COLD AIR DAMMING WILL KEEP TEMPS ON THE
COOL SIDE. MULTI-MODEL CONSENSUS IS ALREADY KEYING ON THIS AND
DROPPED THE PREVIOUS FORECAST BY SEVERAL DEGREES WHEN BLENDED IN.
IF SECONDARY LOW PRES DEVELOPS AS SUGGESTS BY OPERATIONAL AND
ENSEMBLE GUIDANCE...THESE COOLER SFC TEMPS COULD CONTINUE INTO
WED WITH THE COASTAL FRONT TUCKING BACK IN BEHIND IT.
&&
.AVIATION /16Z THURSDAY THROUGH MONDAY/...
SHORT TERM...IFR CONDITIONS IN LOW STRATUS AND AREAS OF FOG AND
DRIZZLE WILL CONTINUE THROUGH THE MORNING AND INTO THE AFTERNOON
AS SHARP SURFACE INVERSIONS REMAIN IN PLACE. LLWS WILL ALSO BE A
CONCERN DUE TO A RATHER STRONG LOW LEVEL JET ABOVE THE INVERSION
THROUGH MUCH OF THE DAY. BY MID TO LATE AFTERNOON ENOUGH MIXING
OCCURS TO SCOUR OUT THE INVERSIONS AND CONDITIONS TO IMPROVE TO
VFR AS WINDS ALSO SHIFT TO THE WEST. TONIGHT AND FRIDAY CONDITIONS
WILL BE VFR.
LONG TERM...VFR TO BEGIN THE PERIOD AS HIGH PRES IS IN CONTROL OF
THE REGION. CLOUDS INCREASE FROM THE W LATE SAT...WITH AREAS OF
MVFR AND LOCAL IFR DEVELOPING OVERNIGHT. EXPECTING MAINLY -RA FOR
ALL TERMINALS...THOUGH A LITTLE MIX MAY DEVELOP NEAR HIE
OVERNIGHT SAT. VFR RETURNS SUN EVE AS STRONG HIGH PRES MOVES INTO
THE AREA THRU MON.
&&
.MARINE...
SHORT TERM...A SCA WILL REMAIN IN PLACE AND WILL BE EXTENDED TO
FRIDAY MORNING OVER THE OUTER WATERS DUE TO FIRST WINDS AND SEAS
AND THEN JUST HAZ SEAS AS WINDS SHIFT TO THE WEST AND BECOME
LIGHT. THE SCA OVER PENOBSCOT BAY WILL BE DROPPED AND THE SCA OVER
CASCO BAY WILL BE FOR HAZ SEAS UNTIL 1 PM.
LONG TERM...WINDS AND SEAS LOOK TO REMAIN BELOW SCA THRESHOLDS
UNTIL EARLY NEXT WEEK WHEN STRONG HIGH PRES MOVES TOWARDS THE
WATERS. THE ACCOMPANYING NWLY CAA WILL MOST LIKELY BRING WINDS AND
SEAS TO SCA CONDITIONS. WEAK LOW PRES DEVELOPING IN THE GULF OF ME
TUE MAY EXTEND SCA CONDITIONS INTO MIDWEEK.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS UNTIL 1 PM EST THIS
AFTERNOON FOR ANZ153.
SMALL CRAFT ADVISORY UNTIL 7 AM EST FRIDAY FOR ANZ150-152-154.
&&
$$
NEAR TERM...HANES
SHORT TERM...MARINE
LONG TERM...LEGRO
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
406 PM EST THU DEC 24 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 405 PM EST THU DEC 24 2015
WV IMAGERY AND RAP ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WEST INTO THE CNTRL CONUS RESULTING IN SW FLOW FROM THE
PLAINS INTO THE CNTRL PLAINS TO THE NRN LAKES. A SHRTWV FROM SE SD
INTO WRN IA SUPPORTED AN AREA OF SNOW OVER IA. OTHERWISE...DRY
CONDITIONS PREVAILED FROM NRN MN THROUGH UPPER MI. WINDS HAVE
DIMINISHED THIS AFTERNOON AS THE PRES GRADIENT WEAKENS IN ADVANCE OF
HIGH PRES BUILDING TOWARD THE AREA FROM THE NRN PLAINS. EVEN WITH 850
MB TEMPS NEAR -10C...ONLY A FEW FLURRIES OBSERVED FOR WEST FLOW LES
AREAS AS INVERSION HEIGHTS HAVE DROPPED TO AROUND 3K-4K FT.
TONIGHT...WRLY FLOW WITH LOW LEVEL CONV WILL FAVOR CONTINUED CHANCE
OF LIGHT SNOW SHOWERS FOR THE KEWEENAW. HOWEVER...WITH THE TOP OF
THE CLOUD LAYER NEAR -10C...ICE NUCLEI MAY BE LACKING RESULTING
POTENTIAL FOR SOME FZDZ. OTHERWISE...WINDS WILL CONTINUE TO DIMINISH
WITH GRADUAL CLEARING OVER THE WEST HALF LATE TONIGHT. TEMPS SHOULD
DROP INTO THE UPPER TEENS TO LOWER 20S.
FRIDAY...THE RIDGE WILL BUILD INTO THE WRN LAKES WITH PARTLY TO
MOSTLY SUNNY SKIES. THE SUNSHINE WILL HELP PUSH TEMPS INTO THE 30 TO
35 RANGE...COLDEST OVER THE WEST WITH THE MOST SNOW COVER.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM EST THU DEC 24 2015
THE PHASING OF A COUPLE PIECES OF UPPER LEVEL ENERGY WILL RESULT IN
SOME LIGHT TO POTENTIALLY MODERATE SNOW AT TIMES OVER MUCH OR ALL OF
THE CWA LATE FRI NIGHT UNTO EARLY SAT NIGHT BEFORE TRANSITIONING TO
LES. MODELS CONTINUE TO TREND NW WITH THE HEAVIEST QPF/SNOW...SO
WILL CONTINUE SHOWING THAT TREND IN THE FORECAST. ALSO...MODELS ARE
NOT IN COMPLETE AGREEMENT ON PRECIP AMOUNTS...SO THERE REMAINS SOME
UNCERTAINTY THERE AS WELL. AT THIS POINT...EXPECT GREATEST SNOWFALL
FROM NCENTRAL UPPER MI...WHERE WINDS WILL TURN OUT OF THE NE ON SAT
PROVIDING UPSLOPE FORCING...TO THE KEWEENAW AND WRN UPPER MI. HAVE 3-
5 INCHES IN THESE AREAS...WITH LOWER AMOUNTS TO THE S AND E. BLOWING
SNOW WILL BE ON THE INCREASE NEAR LAKE SUPERIOR ON SAT AS WIND GUSTS
INCREASE TO 25-30MPH AND BECOME NORTHERLY.
THE WINDS WILL CARRY MUCH COLDER AIR AS AN UPPER TROUGH DROPS
THROUGH SAT NIGHT INTO SUN MORNING. 850MB TEMPS WILL DROP FROM
AROUND -8C AT 00Z SUN TO BETWEEN -15C AND -20C LATE SUN INTO SUN
NIGHT. WINDS WILL BE OUT OF THE NW UNTIL AFTER 00Z MON WHEN WINDS
WILL TURN N-NNE...THEN OUT OF THE E MON MORNING AS A HIGH PASSES N
OF THE AREA. MOST OF THIS TIME WILL SEE INVERSION HEIGHT AROUND
4KFT...WITH GOOD SNOW RATIOS...BUT A SHORTWAVE MAY MOVE THROUGH SUN
EVENING THAT WOULD BRING A HEAVIER BURST OF SNOW AS THE WINDS TURN
MORE N-NNE. OVERALL GOOD CONFIDENCE OF LIGHT TO OCCASIONALLY
MODERATE LES AND PATCHY BLOW SNOW IN NW WIND SNOWBELTS...BECOMING N-
NNE SNOW BELTS LATE SUN INTO MON MORNING. THIS SHOULD RESULT IN
SEVERAL INCHES OF SNOW DURING THIS PERIOD. WILL INCREASE
QPF/SNOWFALL AMOUNTS AND POPS.
FOR NEXT WEEK...LOTS OF UNCERTAINTY AS THE UPPER LOW THAT WILL FORM
OVER THE U.S./MEXICO BORDER LOOKS TO BREAK DOWN AND SHIFT THROUGH
THE REGION TUE INTO TUE NIGHT. THERE ARE A LOT OF VARIABLES WITH
SNOWFALL FORECAST FOR THAT TIME...BUT THE OVERALL APPEARANCE IS THAT
A MAJOR PATTERN CHANGE MAY OCCUR. MODELS SHOW THE LONGWAVE UPPER
TROUGH THAT HAS BEEN OVER THE WRN CONUS SHIFTING TO THE ERN
CONUS...WITH COLDER AIR AND MORE ACTIVE WEATHER THE GENERAL THEME.
STAY TUNED TO LATER FORECASTS FOR DETAILS NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1244 PM EST THU DEC 24 2015
VERY WINDY CONDITIONS...WITH GUSTS AS HIGH AS 45 MPH AT CMX WILL
GRADUALLY DIMINISH THIS AFTERNOON AS HIGH PRESSURE OVER THE PLAINS
BUILDS TOWARD THE REGION. ENOUGH LOW LEVEL MOISTURE WILL LINGER TO
SUPPORT MVFR CIGS THROUGH MUCH OF TONIGHT. CONDITIONS AT IWD AND SAW
IMPROVE TO VFR TOWARD FRI MORNING WHILE CMX REMAINS MVFR TIL MIDDAY
FRI WITH UPSLOPE WESTERLY FLOW CONTINUING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 405 PM EST THU DEC 24 2015
AS HIGH PRESSURE BUILDS TOWARD THE REGION THIS
EVENING...WINDS WILL DROP BELOW GALE FORCE. HIGH PRESSURE BUILDS
ACROSS THE LAKE FOR CHRISTMAS DAY BEFORE ANOTHER LOW MOVES ACROSS
THE SOUTHERN GREAT LAKES SATURDAY NIGHT. STRONGER HIGH PRESSURE IS
EXPECTED TO BUILD ACROSS THE UPPER GREAT LAKES SUNDAY INTO MONDAY.
AFTER TONIGHT...WINDS SHOULD STAY BELOW 30KT ACROSS LAKE SUPERIOR
THROUGH MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 8 PM EST THIS EVENING FOR LSZ265>267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ243>251-264.
LAKE MICHIGAN...
GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...TITUS
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
343 PM CST THU DEC 24 2015
.SHORT TERM: (Through Late Tonight)
Issued at 342 PM CST Thu Dec 24 2015
Low-mid level WAA and MCON along with frontogenetic forcing resulted
in an elongated region of light rain earlier today across central
and northeast MO. This regime is occurring in advance of a low-
amplitude disturbance which is dampening and now located in western
MO. Overall forcing has diminished and shifted to the northeast of
the CWA and only a narrow elongated ribbon of light rain still
persists in west central IL. Present indications is this will also
diminish and shift to the northeast the remainder of the afternoon
and early evening as the disturbance aloft and associated surface
cold front push east. There are some indications in the HRRR and GFS
that a new narrow band of precipitation may try to develop this
evening somewhere in the SE/EC MO into SW IL region in response to a
new region of low level MCON. I have add a slight chance of light
rain in SW IL this evening to account for this and some sprinkles
further west. Otherwise expecting several waves of clouds tonight
with current mid clouds and maybe a period of low clouds up north.
SREF probs and HRRR also suggesting some potential for fog from
across northern/central MO into western IL overnight. I added a
mention of patchy fog in this region, but the overall pattern in
post-frontal air mass with building surface high pressure is at
first glance not one typically associated with alot of fog.
Glass
.LONG TERM: (Friday through Next Thursday)
Issued at 342 PM CST Thu Dec 24 2015
(Friday)
Overall, it looks like a fairly tranquil Christmas Day across the
area. Models continue to hint at WAA along the stalled frontal
boundary to our south generating an axis of convection from AR into
the lower Ohio Valley, with our far southern counties on the very
northern fringes of this activity. The 12z solutions have the axis
of this activity just south of our ara, but since the last few model
cycles have wobbled a bit with the north/south placement of this
precip, I`ve maintained some very low PoPs over our far southern
counties.
Otherwise, it still appears tranquil conditions are on tap for the
region, with temperatures maintaining the very mild levels that have
been commonplace this December. Highs are expected to range from
the middle and upper 40s northwest, to the middle 50s southeast.
Concern then turns to the long-advertised heavy rain threat for the
upcoming weekend and into early next week. Due to some uncertainty
to the placement of the heaviest rain have opted not to go with any
hydro headlines...yet. However, will be reissuing the EFP to
maintain awareness of the threat, which should come in two waves as
described below.
(Saturday Through Monday Night)
The long-advertised spell of wet weather should commence in earnest
either late Friday night or Saturday. Deep southerly flow is
expected to develop across the region in response to the upper level
system digging into the southwest US, and resultant isentropic
ascent over the area should be quite strong with the stalled frontal
boundary and low level baroclinic zone just to our south. In
addition, UVV across the area will be enhance by several weak
shortwaves ejecting ahead of the main system. Moisture should be no
problem as airmass will essentially be the same one that fueled
yesterdays storms in our area, with the increasing southerly flow
adding even more moisture to the unseasonably moist December
airmass. Again, models are wobbling a bit with the exact location of
the axis of the heaviest precip, but they are in excellent agreement
with the general idea that several rounds of convection will track
along and north of the frontal boundary as it attemps to push
north...from eastern OK into s MO and s IL...in the Saturday and
Saturday night time.
It appears that this first round of significant rain will wind down
on Sunday as shortwave in the northern branch of the westerlies
allows Canadian high to drop south, temporarily shutting down the
warm advection and nudging the frontal boundary back south.
Final wave of potentially heavy rain should impact the region on
Monday and Monday night as upper level low lifts out of Texas and
pushes northeast into the mid-Mississippi Valley. Again, moisture-
laden AMS ans strong UVV should produce another band of moderate to
occasionally heavy rain...with embedded thunderstorms...that will
sweep across the area.
It`s not totally out of the question that we could see a bit of
wintry precip Sunday night-Monday night. First concern will be late
Sunday night and into early Monday as surface temps drop below
freezing with the southward surge of the Canadian high...while AMS
aloft remains well above freezing. This threat should be brief and
on the northern fringes of the heavier rainfall...and with the very
warm ground temperatures am not expecting much of an impact from
this. The second concern will be Monday night as the upper low
pushes across the area. It`s possible that the dropping freezing
levels beneath the low could cause the rain to change over to snow,
but not certain if the lower levels will cool enough for any
prolonged period of significant nowfall.
(Tuesday-Thursday)
Medium range progs suggest long wave trof will be parked over the
central CONUS during this time frame. This will finally allow
Canadian air to dominate the region, which should yield more normal
typical wintertime temperatures.
Best holiday wishes to all...from the day shift of the National
Weather Service in St. Louis.
Truett
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1147 AM CST Thu Dec 24 2015
VFR flight conditions are expected to dominate the terminals
through the forecast period. An area of light rain which moved
through central MO this morning impacting KCOU, will continue to
the northeast and weaken and may bring KUIN some sprinkles.
Otherwise mid-high clouds will largely dominate with winds
veering tonight with the approach and passage of a weak surface
cold front. Some of our guidance suggests good IFR or lower fog
potential in central and northeast MO and west central IL
overnight into early Friday morning, and thus added a tempo group
for MVFR conditions given only marginal confidence.
Specifics for KSTL:
VFR flight conditions are expected to dominate through the
forecast period. Mid-high clouds will largely dominate with winds
veering tonight with the approach and passage of a weak surface
cold front. Can`t rule out some sprinkles this evening but
confidence is not great enough to include any mention.
Glass
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 39 54 47 63 / 10 10 50 100
Quincy 32 48 42 54 / 10 5 20 70
Columbia 33 52 45 59 / 5 10 60 80
Jefferson City 33 53 46 60 / 5 10 70 80
Salem 40 56 49 64 / 20 20 50 90
Farmington 39 54 49 64 / 20 20 60 100
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1137 AM CST THU DEC 24 2015
.UPDATE...
ISSUED AT 1128 AM CST THU DEC 24 2015
STRONGEST RADAR RETURNS HAVE BEEN GRADUALLY DECREASING IN
INTENSITY AS THEY SHIFT ACROSS THE MISSOURI RIVER BETWEEN 1030 AND
1130 AM. HOWEVER MODERATE SNOWS WERE STILL FALLING ACROSS THE
OMAHA METRO AND INTO SARPY COUNTY NEAR GRETNA AND BELLEVUE.
REPORTS OF 6 INCHES OF SNOW HAVE BEEN COMMON ACROSS THE METRO FROM
SAUNDERS COUNTY INTO DOUGLAS/SARPY...WITH SOME AS HIGH AS 8
INCHES. COULD SEE ANOTHER INCH OR SO WEST OF THE MISSOURI RIVER
BEFORE BACK EDGE TO MODERATE SNOW MOVES EAST EARLY THIS AFTERNOON.
EAST OF THE RIVER...CONTINUED SNOWS IN POTTAWATTAMIE...HARRISON
AND SHELBY COUNTIES WILL ACCUMULATE AN INCH OR MORE AN HOUR EARLY
THIS AFTERNOON...BUT WITH INTENSITY TRENDS ON THE DOWNWARD
SLIDE...EXPECT TOTALS THERE TO REMAIN GENERALLY NEAR OR UNDER 5
INCHES. WILL LIKELY LET WINTER WEATHER ADVISORIES EXPIRE WEST OF
THE METRO AS SCHEDULED AT NOON...AND LET THE ADVISORY FROM OMAHA
AND EAST CONTINUE INTO MID AFTERNOON.
UPDATE ISSUED AT 932 AM CST THU DEC 24 2015
930 AM SNOW TOTAL AT THE VALLEY WEATHER OFFICE IS 3.8 INCHES AND
STILL COMING DOWN NICELY.
RADAR TRENDS HAVE HIGHEST REFLECTIVITIES FROM SOUTHEAST SAUNDERS
THROUGH NORTHERN SARPY...ALL OF DOUGLAS AND INTO NORTHERN
POTTAWATTAMIE COUNTIES AS OF 930 AM. EXPECT THIS HEAVIEST BAND TO
GRADUALLY WORK EAST OF THE MISSOURI RIVER THROUGH 11 AM WITH A
MARKED DECLINE IN ACTIVITY IN NEBRASKA COUNTIES BY NOON OR SO.
LATEST HRRR FORECASTS BEAR THIS OUT...BUT SNOWFALL OF AN PER HOUR
UNTIL THEN WILL PUT SNOW TOTALS INTO THE 5 TO 6 INCH RANGE FOR
PARTS OF THE OMAHA AND COUNCIL BLUFFS METRO. HAVE UPDATED OUR
FORECAST TO REFLECT THIS.
UPDATE ISSUED AT 844 AM CST THU DEC 24 2015
SNOW CONTINUES OVER MUCH OF EASTERN NEBRASKA AND SOUTHWEST IOWA.
RADAR TRENDS OVER THE LAST HOUR OR SO SHOW MOST INTENSE SNOWFALL
OCCURRING FROM THE NORTH SIDE OF LINCOLN TO OMAHA AND COUNCIL
BLUFFS. MULTIPLE REPORTS OF 2 INCH ACCUMULATIONS FROM LINCOLN TO
OMAHA AS OF 830 AM. ANOTHER 2 INCHES ARE LIKELY IN THE HEAVIEST
BANDS THROUGH 11 AM OR SO. ALREADY SEEING SNOW ENDING IN SOUTH
CENTRAL NEBRASKA JUST WEST OF FAIRBURY AND YORK...AND TOTAL
SNOWFALL OF 3.5 INCHES WERE RECEIVED IN PARTS OF THOSE AREAS. SO
WOULD EXPECT TOTALS HERE TO REACH THAT 3 TO 4 INCH RANGE RATHER
EASILY...WITH LESSER AMOUNTS CLOSER TO AN INCH BY NORFOLK ON
FRINGE OF SNOW BAND...AND IN FAR SOUTHEAST NEBRASKA AND FAR
SOUTHWEST IOWA WHERE TEMPERATURES ARE AT OR ABOVE FREEZING AND
SOME RAIN/SLEET IS MIXING IN.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
...SNOW THROUGH EARLY AFTERNOON...WARMER FOR CHRISTMAS DAY WITH
SNOW FOR NORTHEAST NEBRASKA...
FORECAST CONCERNS FOR TODAY WILL BE FAST-MOVING STORM SYSTEM AND HOW
MUCH SNOW WILL FALL...SPOTTY PRECIPITATION POTENTIAL
CHRISTMAS...THEN EXPANDING PRECIPITATION AREA CHRISTMAS NIGHT INTO
SATURDAY NIGHT WITH ACCUMULATING SNOW/MIX FOR PARTS OF NORTHEAST
NEBRASKA.
THE 00Z OAX SOUNDING HAD DRIED OUT WITH 0.25 PWAT. A LOOK TO THE
WEST AND KLBF HAD PWAT OF 0.20...HOWEVER WAS SATURATED AT 6KFT WITH
TEMPERATURES IN THE DENDRITIC LAYER OF -11 TO -15DEG C.
ON THE H3 CHART...THE 100-140KT STRETCHED FROM NORTHERN CALIFORNIA
ACROSS THE SOUTHERN PLAINS...TURNING NORTH INTO ILLINOIS AND WI.
BROAD TROF WITH EMBEDDED SHORTWAVES STILL DOMINATED THE MID
TROPOSPHERIC FLOW. THE APPROACHING SHORTWAVE AT 06Z EXTENDED FROM
WYOMING ACROSS COLORADO INTO NEW MEXICO. 40M HEIGHT FALLS WERE
ASSOCIATED WITH THIS FEATURE. LIGHTNING STRIKES WERE NOTED WITH
FROM SOUTHEAST UTAH THROUGH COLORADO INTO NEW MEXICO DURING THE
EVENING AND IN NORTHWEST KANSAS AROUND 06Z. AT H7 COLD
TEMPERATURES WERE OBSERVED...HOWEVER THE H85 THERMAL TROUGH WAS
OVER OAX AND TOP...WITH WARMER H85 TEMPERATURES OVER WESTERN
KANSAS. H85 MOISTURE WAS RETURNING TO THE ROCKIES ACROSS MEXICO
INTO ARIZONA/NEW MEXICO AND SOUTHWEST COLORADO.
AT 05Z THERE WAS 2-STAR SNOW IN NORTHEAST COLORADO AND 3-STAR SNOW
IN NORTHWEST KANSAS WITH SOME LIGHTNING. AT 0930Z THE WSR-88D
RADAR MOSAIC SHOWED SNOW SPREADING NORTHEAST WITH RETURNS AS CLOSE
AT ALBION BY 10Z AND THE STRONGER RETURNS OVER NORTH CENTRAL
KANSAS AND SOUTH CENTRAL NEBRASKA.
THROUGH 12Z...THE H3 JET IS FORECAST TO STRENGTHEN TO 150KTS OVER
INDIANA. THIS JET COMBINED WITH A RIPPLE IN THE JET OVER COLORADO
HAS A SMALL AREA OF ENHANCED UPPER LEVEL DIVERGENCE WHICH PUSHES
ACROSS THE FORECAST AREA THROUGH 18Z AND ACROSS IOWA DURING THE
AFTERNOON. UPWARD VERTICAL MOTION INCREASES ACROSS CENTRAL
NEBRASKA THROUGH 12Z AND THE FORECAST AREA THIS MORNING. FAVORABLE
MID LEVEL WARM ADVECTION AND THETA-E ADVECTION INCREASE AS WELL.
THE LIFT TODAY HAS VERY FAVORABLE TEMPERATURES AS GOOD SATURATION TO
WORK WITH...SO SHOULD BE EFFICIENT WITH THE SNOW PRODUCTION AND
VISIBILITIES DROPPING DOWN TO LESS THAN A MILE. THE 00Z RUNS OF
THE NAM/GFS HAVE 2 TO 4 INCHES OF SNOW AT OMAHA USING THE COBB
METHOD AND MOST MODELS NOW HAVE BETWEEN 1 AND 4 INCHES ACROSS
PARTS OF THE CWA. THE LOW LEVEL JET IS STRONGER ACROSS
KANSAS/MISSOURI/OKLAHOMA AND THERE ARE MORE RETURNS IN KANSAS THAN
THE MODELS HAVE. THE 06Z NAM IS ABOUT 1 COUNTY FARTHER SOUTH WITH
THE HIGHER SNOW AMOUNTS...HOWEVER THE LATEST HRRR EXP HAS THE
HIGHER SNOW TRACK SLIGHTLY NORTH. SHORT MET WATCH WILL HAVE THE
BEST HANDLE ON WHERE THE HEAVIER AMOUNTS WILL FALL. OUR CURRENT
FORECAST HAS HIGHEST AMOUNTS RIGHT THROUGH EAST CENTRAL NEBRASKA
INTO WESTERN IOWA. WITH THE SNOW COMING IN DURING THE EARLY/MID
MORNING COMMUTE AND LASTING THROUGH LUNCH. AMOUNTS OF 1 TO 4
INCHES ARE EXPECTED SO DECIDED TO ISSUE A WINTER WEATHER
ADVISORY. HOLIDAY TRAVEL IS ALSO ONGOING...ALTHOUGH SOME OF THE
TRAVEL SHOULD ACTUALLY BE LIGHTER WITH SCHOOLS ON BREAK AND PEOPLE
ON HOLIDAY. THE SNOW WILL END FROM WEST TO EAST...AND SHOULD BE
EAST OF THE AREA BY MID AFTERNOON. HIGHS TODAY SHOULD MOSTLY BE IN
THE LOWER TO MID 30S...HOWEVER WARMER HIGHS AROUND 40 OR THE LOWER
40S COULD BE REACHED NEAR THE KANSAS BORDER. THE WINDS SHOULD NOT
BE AN ISSUE...MOSTLY UNDER 10 MPH.
THERE IS A BREAK FOR TONIGHT AND ALREADY ON CHRISTMAS DAY...THERE IS
SOME WEAK ENERGY PUSHING INTO THE PLAINS AHEAD OF TROUGH OVER THE
ROCKIES/SIERRAS. CLOUDS AND SOME SNOW/MIX CHANCES...ESPECIALLY IN
PARTS OF NORTHEAST NEBRASKA AND AREAS FARTHER WEST. CHRISTMAS
NIGHT...THE BRUNT OF THE SNOW IS ACROSS SOUTH DAKOTA AND
MINNESOTA...AND CLIPS PARTS OF NORTHEAST NEBRASKA AND NORTHWEST
IOWA WITH ACCUMULATING SNOW. SPOTTY RAIN/MIX WILL BE POSSIBLE
ACROSS PARTS OF THE REST OF THE CWA. SATURDAY...THE COLD AIR MOVES
FARTHER SOUTH AND WILL CONTINUE TO MENTION SNOW/MIX/RAIN...HOWEVER
ANY ACCUMULATIONS APPEAR SLIGHT...EXPECT NORTHEAST NEBRASKA COULD
SEE MORE ACCUMULATIONS. SATURDAY NIGHT...THE EC IS DRY...HOWEVER
THE NAM/SREF/GEM STILL LINGER SOME LIGHT SNOW IN THE EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 345 AM CST THU DEC 24 2015
THE GFS/EC START OUT THE EXTENDED IN GOOD AGREEMENT WITH CLOSED
H5 LOW PRESSURE OVER SOUTHWEST TX INTO MEXICO...EXTENDING THE
TROUGH NORTHWARD ACROSS PARTS OF NEBRASKA INTO THE GREAT LAKES.
HOWEVER...BY MONDAY THERE ARE HUGE DIFFERENCES...THE EC IS FARTHER
NORTH WITH THE TRACK OF THE H5 LOW INTO NORTHERN TEXAS WHILE THE
GFS IS SOUTH. WILL TREND WITH THE EC AND MAINTAIN POPS MONDAY AND
MONDAY NIGHT. SHOULD THE EC WIN OUT...COULD BE SIGNIFICANT SNOW
ACCUMULATIONS FOR PARTS OF THE FORECAST AREA...WHILE THE GFS
MISSES US. SOUTHWEST IOWA COULD SEE A MIX IF THIS TRACK HOLDS...
OTHERWISE...WE ARE MAINLY ON THE COLD SIDE OF THE STORM SYSTEM. BY
WEDNESDAY...THE BULK OF THE STORM SYSTEM IS TO OUR NORTH AND EAST.
COULD BE SOME WRAP-AROUND...THEN WE ARE DRY WEDNESDAY NIGHT AND
THURSDAY. LOOK FOR AT OR BELOW NORMAL TEMPERATURES SUNDAY THROUGH
THURSDAY.
&&
.AVIATION...(18Z TAFS FOR KOFK...KLNK AND KOMA.)
ISSUED AT 1128 AM CST THU DEC 24 2015
MODERATE SNOWS NEAR KOMA WILL GRADUALLY END EARLY IN THE TAF
PERIOD...ALLOWING VSBYS TO IMPROVE MARKEDLY BY 20Z. CIGS WILL ALSO
LIFT TO MVFR WITH SNOW ENDING AT ALL TAF SITES. A GRADUAL
IMPROVEMENT IN CIGS WILL TO VFR IS EXPECTED BY 00Z AT ALL EASTERN
NEBRASKA TAF SITES. HOWEVER LIGHT WINDS AND CLEARING SKIES
COMBINED WITH FRESH SNOW COVER WILL LIKELY LEAD TO AREAS OF FOG
LATER TONIGHT...ESPECIALLY AT KOMA AND KLNK WHERE VSBYS COULD
EASILY DROP TO BELOW A MILE AFTER 06Z.
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR NEZ034-
045-052-053-067.
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR NEZ044-050-051-
065-066-078.
IA...WINTER WEATHER ADVISORY UNTIL 2 PM CST THIS AFTERNOON FOR IAZ043-
055-056-069-079.
&&
$$
UPDATE...DERGAN
SHORT TERM...ZAPOTOCNY
LONG TERM...ZAPOTOCNY
AVIATION...DERGAN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
250 PM EST THU DEC 24 2015
.SYNOPSIS...
A STRONG UPPER RIDGE WILL REMAIN ANCHORED OFF THE SOUTHEAST COAST
FOR THE NEXT WEEK. A SERIES OF SHORTWAVES RIDING ALONG THE WESTERN
PERIPHERY OF THE UPPER RIDGE WILL BRING BOUTS OF RAINFALL TO PA
THROUGH THIS WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
RADAR LOOP AT 10Z SHOWING A WEAKENING LINE OF CONVECTION MOVING
THROUGH CENTRAL PA ALONG AXIS OF LL JET. SFC ANALYSIS INDICATES
COLD FRONT IS LAGGING TO THE WEST ACROSS EASTERN OHIO. RADAR
TRENDS AND LATEST HRRR SUPPORT THE IDEA OF THIS BAND OF SCT
SHOWERS PROGRESSES EASTWARD ACROSS THE REGION THIS MORNING...EXITING
ALL BUT EXTREME SE PA BY MIDDAY.
ALTHOUGH NO LIGHTNING STRIKES NOTED AT 10Z...WILL CONTINUE TO
MENTION A SLIGHT CHC OF THUNDER COINCIDENT WITH FROPA LATE
AM/EARLY AFTN ACROSS THE SE COUNTIES...WHERE MDLS DEVELOP SOME
MODEST CAPES.
GUIDANCE STILL SUGGESTING CLEARING SKIES WILL OVERSPREAD MUCH OF
CENTRAL PA BY AFTN...AS SFC RIDGING AND LOWER PWAT AIR MASS
ARRIVES BEHIND COLD FRONT. CLOUDS AND THE LINGERING CHC OF A
SHOWER MAY PERSIST THRU EVENING ACROSS THE SOUTHEAST IN THE
VICINITY OF STALLED OUT FRONT.
THE BIGGEST STORY OF THIS CHRISTMAS EVE REMAINS THE RECORD
BREAKING TEMPS. RECORDS HAVE ALREADY FALLEN AT KBFD/KIPT/KMDT AND
ARE VERY LIKELY TO FALL AT KAOO/KUNV. SREF PLUMES INDICATE STEADY
OR SLOWLY FALLING TEMPS TODAY ACROSS THE NW MTNS...WHERE FROPA
WILL OCCUR EARLY IN THE DAY. HOWEVER...READINGS SHOULD RISE
SEVERAL DEGREES ELSEWHERE...WITH SUPERBLEND AND ECME MOS
SUPPORTING MAX TEMPS FROM ARND 60F ACROSS THE NW MTNS...TO ARND
70F OVR THE LOWER SUSQ VALLEY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/...
WEAK RIDGE OF HIGH PRES AND ASSOC LOW PWAT AIR MASS SHOULD PROVIDE
FAIR WX FOR MOST OF CENTRAL PA TONIGHT. ACROSS THE SE
COUNTIES...CAN/T RULE OUT A FEW EVENING SHOWERS ASSOC WITH WEAK
WAVE OF LOW PRES RIDING ALONG STALLED FRONTAL BNDRY. LIKEWISE...A
WEAK SHORTWAVE RIDING ACROSS THE GRT LKS COULD SUPPORT AN ISOLD
SHOWER TOWARD DAWN OVR THE NW MTNS.
A WEAK WAVE RIDING ALONG STALLED FRONTAL BNDRY SOUTH OF PA COULD
SPREAD A BIT OF LGT RAIN INTO THE SOUTHERN PART OF THE STATE
DURING THE PM HOURS OF CHRISTMAS DAY. BLEND OF ENSEMBLE/OPER MDL
DATA SUPPORTS CHC POPS ACROSS THE SOUTHERN TIER AND SLGHT CHC OVR
THE NORTHERN HALF OF THE STATE. OTHERWISE...BIG STORY WILL
CONTINUE TO BE THE MILD WX. GEFS ENS MEAN 925 TEMPS NORTH OF FRONT REMAIN
VERY WARM FOR DECEMBER...LIKELY SUPPORTING MAX TEMPS FROM THE
L50S ACROSS THE NW MTNS...TO THE M60S OVR THE SE COUNTIES.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
A DEEP TROUGH MOVING THROUGH THE CENTRAL UNITED STATES AND LARGE
HIGH PRESSURE AT THE SFC OVER THE EAST COAST WILL DOMINATE THE
WEATHER THROUGH THE WEEKEND. THE STALLED FRONTAL BOUNDARY WILL
CONTINUE TO LIFT NORTH SATURDAY INTO SUNDAY AS A DEEPENING TROUGH
MOVES DOWN THROUGH THE SOUTHWESTERN UNITED STATES. THE INTERACTION
OF THE TROUGH...ALONG WITH THE LARGE HIGH LOCATED OVER THE
ATLANTICWILL COME IN THE FORM OF A QUASI- STATIONARY BOUNDARY
THAT WILL BRING THE NEXT BEST CHANCE FOR PRECIPITATION THIS
WEEKEND.
ALL MID TO LONG RANGE MODELS HAVE THE TROUGH FORM A CUT OFF LOW.
THE BIG QUESTION IS LOCATION HOWEVER THE GEFS/GFS/EC ARE COMING
MORE INTO AGREEMENT ON POSITION AND STRENGTH. ALL OPERATIONAL
RUNS DIG THE LOW THROUGH NORTHERN MEXICO BEFORE TRAVERSING TEXAS
AND LIFTING INTO THE SOUTHERN GREAT LAKES AND THEN MOVING EASTWARD
OVER THE RIDGE. THOUGH THE PREDOMINATE LOCATION IS OVER TEXAS. THE
MODELS ARE COMING INTO A COMMON SOLUTION FOR THE MOVEMENT OF THE
MOIST BOUNDARY THAT SHOULD EXTEND FROM THE TROUGH/LOW THROUGH NEW
ENGLAND. ALL PWATS ARE ANOMALOUS IN THE +3 TO +4 RANGE SO EXPECT
FOR MORE PRECIPITATION SATURDAY THROUGH SUNDAY.
ALL MED RANGE GUIDANCE TRACKS SFC LOW NORTH OF PA ACROSS THE E LAKES
SAT NIGHT...WITH TRAILING COLD FRONT COMING THRU PA EARLY SUNDAY.
COLD AIR DAMMING SCENARIO SATURDAY SHOULD RESULT IN A RELATIVE
COOL DAY /COMPARED TO THOSE RECENTLY/ WITH READINGS STUCK IN THE
40S OVR THE CENTRAL MTNS. WARMER CONDS EXPECTED SUNDAY...AS LOW
LVL COOL AIR IS SCOURED AHEAD OF COLD FRONT. GEFS 925 TEMPS AND EC
MOS SUGGEST TEMPS COULD APPROACH 70F ACROSS THE SE COUNTIES.
AFTER A VERY WARM WEEKEND...STRONG SIGNALS PERSIST FOR A BRIEF
PERIOD OF DRY/COOLER WX MONDAY...AS BULK OF MED RANGE GUIDANCE
INDICATES N STREAM SHORTWAVE WILL BEAT DOWN ATL RIDGE WITH SFC
HIGH BUILDING SE FROM ONTARIO. NEXT CHC OF PRECIP COMES MON
NIGHT/TUESDAY...WHEN ECENS/GEFS BOTH TRACK ANOTHER LOW WEST OF PA
THRU THE GRT LKS. HOWEVER...THIS TIME THERE WILL BE A SFC HIGH AND
ASSOC SUPPLY OF CHILLY LOW LVL AIR PARKED OVR NEW ENG. THUS...ODDS
FAVOR A WINTRY MIX OVR CENTRAL/NORTHERN COUNTIES...TURNING TO RAIN
TUESDAY. HAVE ADJUSTED THE POPS AND THE PRECIP TYPE ACCORDINGLY.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
VFR TO MVFR CIGS AND GENERALLY VFR VSBYS WILL CONTINUE ACROSS THE
REGION INTO THE LATE MORNING HOURS WITH SCATTERED SHOWERS RACING
NEWD AHEAD OF A WEAK COLD FRONT.
THE FRONT WILL CROSS THE WESTERN PENN AIRFIELDS LATE THIS
MORNING...AND THE SUSQ VALLEY TAF SITES EARLY THIS AFTERNOON.
LLWS WILL PERSIST FOR THE NEXT SVRL HOURS PRIOR TO THE ARRIVAL OF
THE COLD FRONT.
A BRIEF DROP TO THE IFR OR EVEN LIFR CIG IS EXPECTED IN THE 13-15Z
PERIOD INVOF KJST AS WINDS VEER TO THE SW THEN WSW...AND LIFT THE
MOIST AND SLIGHTLY COOLER AIR UP OVER THE LAUREL HIGHLANDS.
A FEW TO SVRL HOUR PERIOD OF GUSTY SW-WSW WINDS IS EXPECTED LATE
THIS MORNING AND THIS AFTERNOON...NEAR AND JUST IN THE WAKE OF THE
COLD FRONT.
EXPECT GRADUAL IMPROVEMENT DURING THE AFTERNOON HOURS WITH CLOUD
BASES LIFTING TO 5000 FT AGL OR HIGHER...AS WEAK HIGH PRESSURE
BUILDS TOWARD THE AREA.
OUTLOOK...
CHRISTMAS...NO SIG WX EXPECTED EARLY...MVFR CIGS WITH CHC R LATE
AFTERNOON AND AT NIGHT AS WARM FRONTAL FEATURE LIFTS BACK TO THE
NORTH.
SAT...MVFR/LCL IFR+ CIGS WITH CHC -SHRA.
SUN...RESTRICTIONS POSSIBLE AS FRONT AND -SHRA PASS.
MON...FAIR EARLY...CHC -SHRA LATE.
&&
.CLIMATE...
DECEMBER 2015 CONTINUES TO BE UNSEASONABLY MILD. ANOTHER ROUND OF
WELL ABOVE AVERAGE TEMPERATURES THIS WEEK WILL BRING POTENTIALLY
RECORD SETTING TEMPERATURES FOR WEDNESDAY AND THURSDAY /CHRISTMAS
EVE/. HERE ARE THE CURRENT RECORDS FOR WEDNESDAY THE 23RD AND
THURSDAY THE 24TH...
RECORD HIGH TEMPERATURES...
SITEWED RECORDTHU RECORDNORMAL
HARRISBURG65F (1990)62F (1990)39F
WILLIAMSPORT63F (1990)56F (1931)36F
ALTOONA62F (1957)62F (1965)36F
BRADFORD56F (1990)55F (1965)31F
STATE COLLEGE*65F (1933)63F (1933)36F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. WEDNESDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
RECORD HIGH LOW TEMPERATURES...
SITETHU RECORDFRI RECORDNORMAL
HARRISBURG49F (1931)45F (1891)25F
WILLIAMSPORT45F (2014)43F (1895)22F
ALTOONA41F (1972)42F (1987)21F
BRADFORD44F (1965)42F (1982)16F
STATE COLLEGE*45F (1931)46F (1893)22F
*STATE COLLEGE RECORD IS FROM 7AM TO 7AM COOP SITE...
I.E. THURSDAY/S RECORD IS ACTUALLY 7AM WED - 7AM THU
WITH THE CONTINUED VERY MILD TEMPERATURES...DECEMBER 2015 IS ON
TRACK TO BE THE WARMEST DECEMBER ON RECORD AT ALL SITES.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD/CERU
AVIATION...LAMBERT/MARTIN
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
455 PM EST THU DEC 24 2015
.SYNOPSIS...
DEEP MOISTURE WILL FOCUS MAINLY ON THE SOUTHERN APPALACHIANS TONIGHT
BEFORE GRADUALLY RETREATING TO THE NORTH AND WEST FRIDAY THROUGH THE
WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHEAST OVER THE
WEEKEND...BUT WITH CONTINUED LOW LEVEL MOISTURE IN PLACE. A STRONG
LOW PRESSURE SYSTEM MAY APPROACH FROM THE WEST EARLY NEXT WEEK TO
BRING ANOTHER ROUND OF HEAVY RAINFALL TO THE AREA.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 445 PM...STILL WORKING OFF THAT PRECIP LULL LATE THIS
AFTERNOON. STRONGER...POSSIBLY SEVERE...CONVECTION WAS RACING OUT
EASTWARD ACROSS E CENTRAL GA AND INTO THE MIDLANDS OF SC AHEAD OF
THE MAIN PRECIP BAND. THIS MIGHT BE HELPING TO KILL OFF THE PRECIP
ON THE BACK SIDE...WHICH WAS MOVING INTO NE GEORGIA AND THE UPSTATE.
WILL CUT BACK TEMPORARILY ON THE PRECIP CHANCE OVER THE NC MTNS AND
FOOTHILLS INTO THE EARLY EVENING. TIME WILL TELL SHORTLY IF
SCATTERED CONVECTION DEVELOPING AROUND METRO ATL WILL MAKE A RUN
TOWARD THE AREA AROUND SUNSET. THE HRRR IS NOT REALLY IMPRESSED.
MIGHT HAVE TO CUT BACK EVEN FURTHER ON NEXT UPDATE. DEEP LAYER SW
FLOW WILL PERSIST THROUGH THE PERIOD AS WEAK H5 VORT LOBES MOVE
THROUGH ALOFT. THE BEST MOISTURE WILL FOCUS BACK PRIMARILY ON THE
SRN APPALACHIANS TONIGHT THROUGH FRIDAY AS HEIGHTS SLOWLY BUILD
ACROSS THE SE. THE LOW LEVEL FLOW WILL VEER FARTHER SW AND FOCUS THE
UPSLOPE FORCING AROUND THE FAR SRN AND SW MTNS. THE FLASH FLOOD
WATCH WILL BE EXTENDED FOR THE MOUNTAINS AND ADJACENT FOOTHILLS
THROUGH FRIDAY. INSTABILITY FOR SCT CONVECTION WILL REMAIN BEST IN
PIEDMONT SECTIONS ON FRIDAY...BUT WITH COVERAGE PROBABLY TOO LOW TO
WARRANT A LONGER DURATION WATCH EXPANSITION THERE. MINS WILL BE 30
DEGREES ABOVE CLIMO TONIGHT WITH MAXES 20 DEGREES ABOVE CLIMO FRIDAY
AFTN.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 230 PM EST THURSDAY...A PROMINENT SE RIDGE WILL FORM OVER THE
WEEKEND AS THE SRN STREAM SYSTEM APPROACHING W TX CREATES TREMENDOUS
HEIGHT FALLS WELL TO THE WEST. THE DEEPER MOISTURE WILL GET PUSHED N
AND WEST OF THE FORECAST AREA OVER THE WEEKEND. HOWEVER...LOW LEVEL
UPGLIDE WILL PERSIST OVER WRN SECTIONS AND PERMIT CONTINUED LOW END
SHOWER CHANCES. EXPECT WARM TEMPS AND INSTABILITY THROUGH THE
WEEKEND UNDER THE RIDGE...WITH ISOLD TSTMS POSSIBLE. MAXES WILL BE
IN THE 70S...WITH HIGHER ELEVATION 60S. MINS WILL BE IN THE 50S MTNS
AND 60S PIEDMONT WITH CONTINUED WARM CONDITIONS THROUGH SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM THURSDAY...THE MEDIUM RANGE BEGINS 00Z MONDAY WITH AN
ATLANTIC SURFACE RIDGE BREAKING DOWN AND AN UPPER LEVEL TROUGH AND
ASSOCIATED CLOSED LOW DEEPENING OVER THE SOUTHERN PLAINS. THE LOW
WILL TRANSLATE ACROSS THE MIDWEST MONDAY AND TUESDAY...BRINGING A
SURFACE COLD FRONT JUST TO THE WEST OF THE AREA.
MOIST SOUTH/SOUTHEASTERLY LOW LEVEL FLOW WILL PROVIDE PLENTIFUL
MOISTURE AS A SURFACE WARM FRONT DRAGS NORTH OF THE CWA MONDAY...AND
A SURFACE HIGH POSITIONED OVER THE NORTHEAST CONUS WILL ALLOW A
WEDGE TO BRIEFLY BUILD IN LATE MONDAY THROUGH THE DAY ON TUESDAY.
THE PRESENCE OF THE WEDGE COMBINED WITH THE MOIST SOUTHEASTERLY FLOW
WILL PROVIDE A WINDOW MONDAY NIGHT AND TUESDAY FOR SOME POTENTIAL
ISENTROPIC UPGLIDE...SO HAVE RAISED POPS TO LIKELY FOR MOST OF THE
AREA DURING THAT TIME. THE SURFACE COLD FRONT WILL PASS BY LATE
TUESDAY EVENING...SO POPS ARE TAPERED TO CHANCE TUESDAY NIGHT.
THE LULL IN POPS WILL BE BRIEF TUESDAY NIGHT...AS A FRONTAL BOUNDARY
OVER THE GULF WILL LIFT NORTHWARD TO APPROACH OUR AREA ON WEDNESDAY.
A MOIST TAP OF GULF AIR NEVER REALLY CUTS OFF AFTER THE PREVIOUS
FRONTAL PASSAGE...BUT A LACK OF IMPRESSIVE UPPER LIFT OR OTHER
FORCING WILL KEEP POPS JUST BELOW THE LIKELY CATEGORY. A SECOND
UPPER TROUGH/WEAK LOW WILL PASS WEDNESDAY NIGHT...WITH SOMEWHAT
DRIER AIR ALLOWED TO MOVE IN BEHIND THE FRONT THURSDAY AND FRIDAY.
POPS WILL FINALLY BE LOWERED SUBSTANTIALLY OVERNIGHT THURSDAY AND
INTO FRIDAY MORNING. THERE IS STILL DISAGREEMENT ON THE DEPTH OF THE
FINAL UPPER TROUGH THAT WILL PASS THURSDAY AND FRIDAY...BUT OVERALL
HEIGHT FALLS WILL LEAD TO A GRADUAL DECLINE IN TEMPERATURES TO JUST
5 TO 10 DEGREES ABOVE NORMAL BY FRIDAY.
&&
.AVIATION /22Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONTINUED SHRA WILL AFFECT THE AIRFIELD THROUGH THE AFTN
AND EVENING HOURS...BUT WITH TSRA MUCH MORE DIFFICULT TO TIME.
ANTICIPATE MAINLY MVFR CIGS ON S TO SW MIXING WITH OCCASIONAL
GUSTS...AND THEN A RETURN TO IFR THEN LIFR CIGS OVERNIGHT AS THE
MIXING AND RAINFALL LESSEN. PERISTENT SRLY FLOW SHOULD KEEP VSBY
FROM CRASHING DESPITE THE VERY MOIST GROUND. MVFR CIGS/VSBY WILL BE
VERY SLOW TO IMPROVE THROUGH LATE MORNING FRIDAY.
ELSEWHERE...EXPECT CONTINUED FAIRLY WIDESPREAD SHRA ACROSS THE MTN
AND FOOTHILL TAF SITES...BUT WITH CONVECTIVE CHANCES APPEARING TO BE
A BIT LESS. THE LATEST HRRR DOES BRING SOME CONVECTION BACK TONIGHT
WHICH WILL NEED TO BE MONITORED FOR TEMPO TSRA AFTER 05Z.
OTHERWISE...MVFR TO VFR CIGS EARLY WILL RETURN TO IFR THEN LIFR
OVERNIGHT IN THE MOIST SRLY FLOW. UPSLOPE SHRA ARE LIKELY AT TIMES
THROUGH 18Z FRIDAY.
OUTLOOK...DEEP LAYER MOISTURE AHEAD OF A STALLED FRONT WILL PERSIST
OVER AT LEAST THE MOUNTAINS THROUGH LATE FRIDAY...BEFORE SOME MINOR
DRYING OCCURS OVER THE WEEKEND. SRLY UPSLOPE FLOW WILL PERSIST OVER
THE WEEKEND...HOWEVER...WITH SOME RESTRICTIONS ONCE AGAIN LIKELY.
ANOTHER WET SYSTEM WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
22-04Z 04-10Z 10-16Z 16-18Z
KCLT MED 78% MED 72% MED 72% HIGH 84%
KGSP MED 75% MED 75% HIGH 83% HIGH 85%
KAVL MED 75% MED 75% HIGH 94% HIGH 100%
KHKY HIGH 89% LOW 58% HIGH 80% HIGH 84%
KGMU HIGH 80% HIGH 80% HIGH 86% HIGH 81%
KAND HIGH 89% MED 78% HIGH 86% HIGH 88%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.HYDROLOGY...
ONGOING AND DEVELOPING HYDRO ISSUES WILL BE EXACERBATED BY
ADDITIONAL MODERATE TO HEAVY RAINFALL IN THE EXTREME SOUTHERN
APPALCHIANS TONIGHT INTO FRIDAY. ADDITIONAL QPF OF 1.5 TO 2.5 INCHES
ARE POSSIBLE IN THE SRN ESCARPMENT AREAS...WITH 1 TO 2 INCHES
POSSIBLE ACROSS THE FOOTHILLS...AND AMOUNTS FALLING OFF QUICKLY
FARTHER EAST INTO THE PIEDMONT. LOCALLY HEAVY RAINFALL COULD
REDEVELOP JUST ABOUT ANYWHERE WITH SCATTERED CONVECTION...BUT THE NC
MOUNTAINS...GA MTNS...AND IMMEDIATELY ADJACENT FOOTHILLS SHOULD HAVE
THE LONGEST DURATION HYDRO ISSUES THROUGH FRIDAY. THE FLASH FLOOD
WATCH WILL BE EXTENDED IN THESE AREAS.
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR GAZ010-017-018-
026-028.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR GAZ029.
NC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR NCZ033-035-
048>053-058-059-062>065-501>510.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ036-037-
056-057-068>072-082.
SC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR SCZ001>007-010.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ008-009-
011>014-019.
&&
$$
SYNOPSIS...HG
NEAR TERM...HG/PM
SHORT TERM...HG
LONG TERM...LEV
AVIATION...HG
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
253 PM EST THU DEC 24 2015
.SYNOPSIS...
DEEP MOISTURE WILL FOCUS MAINLY ON THE SOUTHERN APPALACHIANS TONIGHT
BEFORE GRADUALLY RETREATING TO THE NORTH AND WEST FRIDAY THROUGH THE
WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHEAST OVER THE
WEEKEND...BUT WITH CONTINUED LOW LEVEL MOISTURE IN PLACE. A STRONG
LOW PRESSURE SYSTEM MAY APPROACH FROM THE WEST EARLY NEXT WEEK TO
BRING ANOTHER ROUND OF HEAVY RAINFALL TO THE AREA.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 225 PM EST...PRECIPITATION RATES EXPERIENCED A BRIEF LULL THIS
AFTERNOON...BUT BETTER RATES ARE STEADILY RETURNING FROM THE MORE
UNSTABLE AIR ACROSS CENTRAL GA. THE POTENTIAL FOR STRONG CONVECTION
DOES NOT APPEAR IMPRESSIVE AS THE LOW LEVEL JET HAS WEAKENED
SUFFICIENTLY...BUT THUNDER WILL BE POSSIBLE GIVEN SB CAPE VALUES OF
500 TO 1500 J/KG MOST AREAS EAST OF THE MTNS. DEEP LAYER SW FLOW
WILL PERSIST THROUGH THE PERIOD AS WEAK H5 VORT LOBES MOVE THROUGH
ALOFT. THE BEST MOISTURE WILL FOCUS PRIMARILY ON THE SRN
APPALACHIANS TONIGHT THROUGH FRIDAY AS HEIGHTS SLOWLY BUILD ACROSS
THE SE. THE LOW LEVEL FLOW WILL VEER FARTHER SW AND FOCUS THE
UPSLOPE FORCING AROUND THE FAR SRN AND SW MTNS. THE FLASH FLOOD
WATCH WILL BE EXTENDED FOR THE MOUNTAINS AND ADJACENT FOOTHILLS
THROUGH FRIDAY. INSTABILITY FOR SCT CONVECTION WILL REMAIN BEST IN
PIEDMONT SECTIONS ON FRIDAY...BUT WITH COVERAGE PROBABLY TOO LOW TO
WARRANT A LONGER DURATION WATCH EXPANSITION THERE. MINS WILL BE 30
DEGREES ABOVE CLIMO TONIGHT WITH MAXES 20 DEGREES ABOVE CLIMO FRIDAY
AFTN.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
AT 230 PM EST THURSDAY...A PROMINENT SE RIDGE WILL FORM OVER THE
WEEKEND AS THE SRN STREAM SYSTEM APPROACHING W TX CREATES TREMENDOUS
HEIGHT FALLS WELL TO THE WEST. THE DEEPER MOISTURE WILL GET PUSHED N
AND WEST OF THE FORECAST AREA OVER THE WEEKEND. HOWEVER...LOW LEVEL
UPGLIDE WILL PERSIST OVER WRN SECTIONS AND PERMIT CONTINUED LOW END
SHOWER CHANCES. EXPECT WARM TEMPS AND INSTABILITY THROUGH THE
WEEKEND UNDER THE RIDGE...WITH ISOLD TSTMS POSSIBLE. MAXES WILL BE
IN THE 70S...WITH HIGHER ELEVATION 60S. MINS WILL BE IN THE 50S MTNS
AND 60S PIEDMONT WITH CONTINUED WARM CONDITIONS THROUGH SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
AS OF 230 PM THURSDAY...THE MEDIUM RANGE BEGINS 00Z MONDAY WITH AN
ATLANTIC SURFACE RIDGE BREAKING DOWN AND AN UPPER LEVEL TROUGH AND
ASSOCIATED CLOSED LOW DEEPENING OVER THE SOUTHERN PLAINS. THE LOW
WILL TRANSLATE ACROSS THE MIDWEST MONDAY AND TUESDAY...BRINGING A
SURFACE COLD FRONT JUST TO THE WEST OF THE AREA.
MOIST SOUTH/SOUTHEASTERLY LOW LEVEL FLOW WILL PROVIDE PLENTIFUL
MOISTURE AS A SURFACE WARM FRONT DRAGS NORTH OF THE CWA MONDAY...AND
A SURFACE HIGH POSITIONED OVER THE NORTHEAST CONUS WILL ALLOW A
WEDGE TO BRIEFLY BUILD IN LATE MONDAY THROUGH THE DAY ON TUESDAY.
THE PRESENCE OF THE WEDGE COMBINED WITH THE MOIST SOUTHEASTERLY FLOW
WILL PROVIDE A WINDOW MONDAY NIGHT AND TUESDAY FOR SOME POTENTIAL
ISENTROPIC UPGLIDE...SO HAVE RAISED POPS TO LIKELY FOR MOST OF THE
AREA DURING THAT TIME. THE SURFACE COLD FRONT WILL PASS BY LATE
TUESDAY EVENING...SO POPS ARE TAPERED TO CHANCE TUESDAY NIGHT.
THE LULL IN POPS WILL BE BRIEF TUESDAY NIGHT...AS A FRONTAL BOUNDARY
OVER THE GULF WILL LIFT NORTHWARD TO APPROACH OUR AREA ON WEDNESDAY.
A MOIST TAP OF GULF AIR NEVER REALLY CUTS OFF AFTER THE PREVIOUS
FRONTAL PASSAGE...BUT A LACK OF IMPRESSIVE UPPER LIFT OR OTHER
FORCING WILL KEEP POPS JUST BELOW THE LIKELY CATEGORY. A SECOND
UPPER TROUGH/WEAK LOW WILL PASS WEDNESDAY NIGHT...WITH SOMEWHAT
DRIER AIR ALLOWED TO MOVE IN BEHIND THE FRONT THURSDAY AND FRIDAY.
POPS WILL FINALLY BE LOWERED SUBSTANTIALLY OVERNIGHT THURSDAY AND
INTO FRIDAY MORNING. THERE IS STILL DISAGREEMENT ON THE DEPTH OF THE
FINAL UPPER TROUGH THAT WILL PASS THURSDAY AND FRIDAY...BUT OVERALL
HEIGHT FALLS WILL LEAD TO A GRADUAL DECLINE IN TEMPERATURES TO JUST
5 TO 10 DEGREES ABOVE NORMAL BY FRIDAY.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONTINUED SHRA WILL AFFECT THE AIRFIELD THROUGH THE AFTN
AND EVENING HOURS...BUT WITH TSRA MUCH MORE DIFFICULT TO TIME.
ANTICIPATE MAINLY MVFR CIGS ON S TO SW MIXING WITH OCCASIONAL
GUSTS...AND THEN A RETURN TO IFR THEN LIFR CIGS OVERNIGHT AS THE
MIXING AND RAINFALL LESSEN. PERISTENT SRLY FLOW SHOULD KEEP VSBY
FROM CRASHING DESPITE THE VERY MOIST GROUND. MVFR CIGS/VSBY WILL BE
VERY SLOW TO IMPROVE THROUGH LATE MORNING FRIDAY.
ELSEWHERE...EXPECT CONTINUED FAIRLY WIDESPREAD SHRA ACROSS THE MTN
AND FOOTHILL TAF SITES...BUT WITH CONVECTIVE CHANCES APPEARING TO BE
A BIT LESS. THE LATEST HRRR DOES BRING SOME CONVECTION BACK TONIGHT
WHICH WILL NEED TO BE MONITORED FOR TEMPO TSRA AFTER 05Z.
OTHERWISE...MVFR TO VFR CIGS EARLY WILL RETURN TO IFR THEN LIFR
OVERNIGHT IN THE MOIST SRLY FLOW. UPSLOPE SHRA ARE LIKELY AT TIMES
THROUGH 18Z FRIDAY.
OUTLOOK...DEEP LAYER MOISTURE AHEAD OF A STALLED FRONT WILL PERSIST
OVER AT LEAST THE MOUNTAINS THROUGH LATE FRIDAY...BEFORE SOME MINOR
DRYING OCCURS OVER THE WEEKEND. SRLY UPSLOPE FLOW WILL PERSIST OVER
THE WEEKEND...HOWEVER...WITH SOME RESTRICTIONS ONCE AGAIN LIKELY.
ANOTHER WET SYSTEM WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
20-02Z 02-08Z 08-14Z 14-18Z
KCLT HIGH 90% HIGH 87% HIGH 83% HIGH 90%
KGSP HIGH 82% MED 75% HIGH 90% HIGH 90%
KAVL HIGH 85% MED 72% HIGH 83% HIGH 90%
KHKY HIGH 92% MED 64% HIGH 87% HIGH 90%
KGMU HIGH 89% MED 75% HIGH 83% HIGH 90%
KAND HIGH 94% MED 78% HIGH 88% HIGH 90%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.HYDROLOGY...
ONGOING AND DEVELOPING HYDRO ISSUES WILL BE EXACERBATED BY
ADDITIONAL MODERATE TO HEAVY RAINFALL IN THE EXTREME SOUTHERN
APPALCHIANS TONIGHT INTO FRIDAY. ADDITIONAL QPF OF 1.5 TO 2.5 INCHES
ARE POSSIBLE IN THE SRN ESCARPMENT AREAS...WITH 1 TO 2 INCHES
POSSIBLE ACROSS THE FOOTHILLS...AND AMOUNTS FALLING OFF QUICKLY
FARTHER EAST INTO THE PIEDMONT. LOCALLY HEAVY RAINFALL COULD
REDEVELOP JUST ABOUT ANYWHERE WITH SCATTERED CONVECTION...BUT THE NC
MOUNTAINS...GA MTNS...AND IMMEDIATELY ADJACENT FOOTHILLS SHOULD HAVE
THE LONGEST DURATION HYDRO ISSUES THROUGH FRIDAY. THE FLASH FLOOD
WATCH WILL BE EXTENDED IN THESE AREAS.
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR GAZ010-017-018-
026-028.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR GAZ029.
NC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR NCZ033-035-
048>053-058-059-062>065-501>510.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ036-037-
056-057-068>072-082.
SC...FLASH FLOOD WATCH THROUGH FRIDAY EVENING FOR SCZ001>007-010.
FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ008-009-
011>014-019.
&&
$$
SYNOPSIS...HG
NEAR TERM...HG
SHORT TERM...HG
LONG TERM...LEV
AVIATION...HG
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
227 PM EST THU DEC 24 2015
.SYNOPSIS...
DEEP MOISTURE WILL FOCUS MAINLY ON THE SOUTHERN APPALACHIANS TONIGHT
BEFORE GRADUALLY RETREATING TO THE NORTH AND WEST FRIDAY THROUGH THE
WEEKEND. HIGH PRESSURE WILL BUILD IN FROM THE SOUTHEAST OVER THE
WEEKEND...BUT WITH CONTINUED LOW LEVEL MOISTURE IN PLACE. A STRONG
LOW PRESSURE SYSTEM MAY APPROACH FROM THE WEST EARLY NEXT WEEK TO
BRING ANOTHER ROUND OF HEAVY RAINFALL TO THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1255 PM EST...PRECIPITATION RATES ARE EXPERIENCING A RELATIVE
LULL EARLY THIS AFTERNOON AS THE BETTER RATES ARE SHIFTING OFF THE
NE...AND ALSO GATHER TO THE S ACROSS CENTRAL GA. THE LATEST HRRR
FEATURES THE LULL LASTING THROUGH THE EVENING...WITH FAIRLY HIGH
POPS FOR CONTINUED SRLY UPSLOPE...BUT WITH LOWER RATES AND WEAK
CONVECTION. ALSO...THE BEST LOW LEVEL JET HAS WEAKENED AND VEERED SO
THE TSTM THREAT SHOULD BE FAIRLY MINIMAL FOR ALL BUT LOCALLY HEAVY
RAINFALL AND ISOLD WIND GUSTS.
OTHERWISE...DEEP LAYER SW FLOW WILL PERSIST THROUGH THE PERIOD AS
WEAK H5 VORT LOBES MOVE THROUGH ALOFT. THE BEST MOISTURE WILL FOCUS
PRIMARILY ON THE SRN APPALACHIANS TONIGHT THROUGH FRIDAY AS HEIGHTS
SLOWLY BUILD ACROSS THE SE. THE LOW LEVEL FLOW WILL VEER FARTHER SW
AND FOCUS THE UPSLOPE FORCING AROUND THE FAR SRN AND SW MTNS. THE
FLASH FLOOD WATCH WILL LIKELY BE EXTENDED FOR AT LEAST THE
MOUNTAINS. INSTABILITY FOR SCT CONVECTION WILL REMAIN BEST IN
PIEDMONT SECTIONS ON FRIDAY...BUT WITH COVERAGE PROBABLY TOO LOW TO
WARRANT A LONGER DURATION WATCH EXPANSIION THERE. MINS WILL BE 30
DEGREES ABOVE CLIMO TONIGHT WITH MAXES 20 DEGREES ABOVE CLIMO FRIDAY.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AT 230 AM THURSDAY...ON FRIDAY MORNING AN UPPER RIDGE WILL BE
CENTERED OVER THE WESTERN ATLANTIC...WHILE AN UPPER TROUGH WILL BE
OVER THE ROCKIES. AN UPPER LOW CLOSES OFF IN THE SOUTHWEST USA...
WHILE NORTHERN STREAM PROGRESSES AND GOES OUT OF PHASE. BY SUNDAY
MORNING THE UPPER LOW IS OVER NORTH CENTRAL MX...WHILE THE ATLANTIC
UPPER RIDGE RETROGRESSES SLIGHTLY OVER THE SOUTHEAST USA. THIS PATTERN
RESULTS IN THE BULK OF UPPER LEVEL ENERGY BEING DIRECTED WELL TO OUR
WEST AND NORTH.
AT THE SURFACE...ON FRIDAY A NEARLY STATIONARY FRONT WILL BE OVER
THE SOUTHERN APPALACHIANS...WITH SOUTHWESTERLY GULF INFLOW AHEAD OF
THE BOUNDARY IMPACTING OUR AREA. THE FRONT MOVES NORTH TO THE OH AND
POTOMAC RIVER VALLEYS ON SATURDAY...WHILE GULF INFLOW CONTINUES. A
COLD FRONT WILL MOVE INTO THE OH AND MID MS RIVER VALLEYS BY SUNDAY
MORNING...WITH GULF INFLOW PERSISTING.
THE SOUTHWESTERLY ASPECT OF GULF INFLOW WILL HAMPER ISENTROPIC
UPGLIDE AND UPSLOPE FLOW...LIMITING PRECIPITATION PRODUCTION. BOTH
INSTABILITY AND SHEAR WILL BE PRESENT ON FRIDAY...AND THERE A
MARGINAL RISK FOR SEVERE WEATHER...MAINLY DURING THE DAY. WHILE
INSTABILITY IS PRESENT ON SATURDAY...SHEAR WILL BE MORE LIMITED.
TEMPERATURES WILL RUN WELL ABOVE NORMAL UNDER THE INFLUENCE OF THE
ATLANTIC RIDGE...WITH MINIMUMS EVEN MORE EXTREME DUE TO ROBUST
MOISTURE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AT 230 AM THURSDAY...ON SUNDAY MORNING AN ATLANTIC UPPER RIDGE WILL
EXTEND WEST TO THE SOUTHEAST USA...WHILE A CLOSED UPPER LOW WILL BE
OVER NORTH CENTRAL MX. THE TROUGH MOVES OVER TX ON MONDAY...AND
APPROACHES THE GREAT LAKES ON TUESDAY...WHILE THE RIDGE TO THE EAST
GRADUALLY BREAKS DOWN. MEANWHILE...ANOTHER AN UPPER LOW MOVES INTO
THE BASE TO THE WEST TROUGH. THIS LOW NEVER DEEPENS LIKE THE
PREVIOUS ONE...AND FILLS AS IT CROSSES THE PLAINS ON WEDNESDAY.
AT THE SURFACE...THE COLD FRONT OVER THE OH RIVER VALLEY SUNDAY
MORNING IS EXPECTED TO PUSH SOUTH O THE CAROLINAS BY MONDAY AS HIGH
PRESSURE OVER CANADA EXTENDS SOUTH ALONG THE EAST COAST. MEANWHILE
GULF INFLOW AHEAD OF A COLD FRONT WILL IMPACT THE GULF STATES. THE
CAROLINA FRONT MOVES SLOWLY NORTH ON TUESDAY...WHILE THE COLD FRONT
TO OUR WEST CROSSES THE GULF STATES...AND GULF INFLOW INCREASES INTO
THE SOUTHERN APPALACHIANS. THE COLD FRONT CROSSES THE MOUNTAINS AND
STALLS OVER THE PIEDMONT ON WEDNESDAY...WHILE GULF MOISTURE
CONTINUES TO SPREAD NE ALONG AND OVER THE BOUNDARY.
ISENTROPIC UPGLIDE AND SOUTHERLY UPSLOPE FLOW WILL BE MAINLY
LIMITED TO MONDAY AHEAD TO THE APPROACHING COLD FRONT. OTHERWISE...
LOW LEVEL FLOW GENERALLY BE FROM THE SE...WITH LITTLE UPGLIDE UP
UPSLOPE COMPONENT. THIS WILL LIMIT PRECIPITATION PRODUCTION...
DESPITE THE PROLONGED NATURE OF MOIST INFLOW. TEMPERATURES WILL
REMAIN ABOVE NORMAL...BUT WITH A DOWNWARD TRENDS AS HEIGHT FALL
ALOFT WITH THE BREAKDOWN OF THE UPPER RIDGE.
&&
.AVIATION /20Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONTINUED SHRA WILL AFFECT THE AIRFIELD THROUGH THE AFTN
AND EVENING HOURS...BUT WITH TSRA MUCH MORE DIFFICULT TO TIME.
ANTICIPATE MAINLY MVFR CIGS ON S TO SW MIXING WITH OCCASIONAL
GUSTS...AND THEN A RETURN TO IFR THEN LIFR CIGS OVERNIGHT AS THE
MIXING AND RAINFALL LESSEN. PERISTENT SRLY FLOW SHOULD KEEP VSBY
FROM CRASHING DESPITE THE VERY MOIST GROUND. MVFR CIGS/VSBY WILL BE
VERY SLOW TO IMPROVE THROUGH LATE MORNING FRIDAY.
ELSEWHERE...EXPECT CONTINUED FAIRLY WIDESPREAD SHRA ACROSS THE MTN
AND FOOTHILL TAF SITES...BUT WITH CONVECTIVE CHANCES APPEARING TO BE
A BIT LESS. THE LATEST HRRR DOES BRING SOME CONVECTION BACK TONIGHT
WHICH WILL NEED TO BE MONITORED FOR TEMPO TSRA AFTER 05Z.
OTHERWISE...MVFR TO VFR CIGS EARLY WILL RETURN TO IFR THEN LIFR
OVERNIGHT IN THE MOIST SRLY FLOW. UPSLOPE SHRA ARE LIKELY AT TIMES
THROUGH 18Z FRIDAY.
OUTLOOK...DEEP LAYER MOISTURE AHEAD OF A STALLED FRONT WILL PERSIST
OVER AT LEAST THE MOUNTAINS THROUGH LATE FRIDAY...BEFORE SOME MINOR
DRYING OCCURS OVER THE WEEKEND. SRLY UPSLOPE FLOW WILL PERSIST OVER
THE WEEKEND...HOWEVER...WITH SOME RESTRICTIONS ONCE AGAIN LIKELY.
ANOTHER WET SYSTEM WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
19-01Z 01-07Z 07-13Z 13-18Z
KCLT HIGH 92% HIGH 85% HIGH 83% HIGH 83%
KGSP MED 79% MED 76% HIGH 88% HIGH 81%
KAVL MED 72% MED 76% HIGH 86% HIGH 80%
KHKY HIGH 93% MED 62% HIGH 81% HIGH 85%
KGMU HIGH 87% MED 74% MED 77% HIGH 85%
KAND HIGH 86% MED 68% HIGH 84% HIGH 83%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.HYDROLOGY...
ONGOING AND DEVELOPING HYDRO ISSUES WILL BE EXACERBATED BY
ADDITIONAL MODERATE TO HEAVY RAINFALL IN THE EXTREME SOUTHERN
APPALCHIANS TONIGHT INTO FRIDAY. ADDITIONAL QPF OF 1.5 TO 2 INCHES
IS LIKELY IN THE SRN ESCARPMENT AREAS...WITH AMOUNTS FALLING OFF
QUICKLY FARTHER EAST INTO THE PIEDMONT. LOCALLY HEAVY RAINFALL COULD
REDEVELOP JUST ABOUT ANYWHERE WITH SCATTERED CONVECTION...BUT THE NC
MOUNTAINS...GA MTNS...AND IMMEDIATELY ADJACENT FOOTHILLS SHOULD HAVE
THE LONGEST DURATION HYDRO ISSUES THROUGH FRIDAY.
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR THURSDAY DECEMBER 24...
AVL 72 1955
CLT 71 1982...1931
GSP 71 1964
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR WEDNESDAY DEC 23...
AVL 59 1990
CLT 63 1990
GSP 61 1990
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR THURSDAY DEC 24...
AVL 54 1932
CLT 56 1891
GSP 55 1931
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR GAZ010-017-
018-026-028-029.
NC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ033-
035>037-048>053-056>059-062>065-068>072-082-501>510.
SC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ001>014-
019.
&&
$$
SYNOPSIS...JAT
NEAR TERM...HG
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...HG
HYDROLOGY...
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
115 PM EST THU DEC 24 2015
.SYNOPSIS...
UNSETTLED WEATHER AND ABOVE NORMAL TEMPERATURES WILL CONTINUE
THROUGH EARLY NEXT WEEK AHEAD OF A COLD FRONT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 950 AM EST...THE LOW LEVEL SOUTHWESTERLY JET MAXIMIZED OVER
THE FORECAST AREA EARLY THIS MORNING...BUT NOW CONTINUES TO WEAKEN
SLIGHTLY AND VEER. THIS...COMBINED WITH THE SOMEWHAT LIMITED
INSTABILITY DUE TO THE WIDESPREAD CLOUDS...PRECIP...AND WARM
PROFILES...APPEARS TO BE LIMITING THE STRENGTH OF THE CONVECTION
THUS FAR. HOWEVER...CONTINUED S TO SW UPSLOPE FLOW WILL PERMIT THE
FOCUS OF ONGOING AND NEW HYDRO CONCERNS TO FOCUS MORE SOLIDLY ON THE
MTNS AND THE IMMEDIATELY ADJACENT FOOTHILLS GOING FORWARD. THE FLASH
FLOD WATCH WILL CONTINUE THROUGHOUT...BUT THE LANDSLIDE WORDING WILL
BE BEEFED UP FOR LOCATIONS IN AND NEAR THE HIGHER TERRAIN THE REST
OF TODAY THROUGH TONIGHT.
OTHERWISE...HIGHS TODAY WILL BE 20 TO 25 DEGREES ABOVE NORMAL AND
WILL THREATEN RECORDS. LOWS TONIGHT WILL BE 30 TO 35 DEGREES ABOVE
NORMAL AND WILL THREATEN RECORDS FOR HIGHEST MINIMUM TEMPERATURES.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AT 230 AM THURSDAY...ON FRIDAY MORNING AN UPPER RIDGE WILL BE
CENTERED OVER THE WESTERN ATLANTIC...WHILE AN UPPER TROUGH WILL BE
OVER THE ROCKIES. AN UPPER LOW CLOSES OFF IN THE SOUTHWEST USA...
WHILE NORTHERN STREAM PROGRESSES AND GOES OUT OF PHASE. BY SUNDAY
MORNING THE UPPER LOW IS OVER NORTH CENTRAL MX...WHILE THE ATLANTIC
UPPER RIDGE RETROGRESSES SLIGHTLY OVER THE SOUTHEAST USA. THIS PATTERN
RESULTS IN THE BULK OF UPPER LEVEL ENERGY BEING DIRECTED WELL TO OUR
WEST AND NORTH.
AT THE SURFACE...ON FRIDAY A NEARLY STATIONARY FRONT WILL BE OVER
THE SOUTHERN APPALACHIANS...WITH SOUTHWESTERLY GULF INFLOW AHEAD OF
THE BOUNDARY IMPACTING OUR AREA. THE FRONT MOVES NORTH TO THE OH AND
POTOMAC RIVER VALLEYS ON SATURDAY...WHILE GULF INFLOW CONTINUES. A
COLD FRONT WILL MOVE INTO THE OH AND MID MS RIVER VALLEYS BY SUNDAY
MORNING...WITH GULF INFLOW PERSISTING.
THE SOUTHWESTERLY ASPECT OF GULF INFLOW WILL HAMPER ISENTROPIC
UPGLIDE AND UPSLOPE FLOW...LIMITING PRECIPITATION PRODUCTION. BOTH
INSTABILITY AND SHEAR WILL BE PRESENT ON FRIDAY...AND THERE A
MARGINAL RISK FOR SEVERE WEATHER...MAINLY DURING THE DAY. WHILE
INSTABILITY IS PRESENT ON SATURDAY...SHEAR WILL BE MORE LIMITED.
TEMPERATURES WILL RUN WELL ABOVE NORMAL UNDER THE INFLUENCE OF THE
ATLANTIC RIDGE...WITH MINIMUMS EVEN MORE EXTREME DUE TO ROBUST
MOISTURE.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AT 230 AM THURSDAY...ON SUNDAY MORNING AN ATLANTIC UPPER RIDGE WILL
EXTEND WEST TO THE SOUTHEAST USA...WHILE A CLOSED UPPER LOW WILL BE
OVER NORTH CENTRAL MX. THE TROUGH MOVES OVER TX ON MONDAY...AND
APPROACHES THE GREAT LAKES ON TUESDAY...WHILE THE RIDGE TO THE EAST
GRADUALLY BREAKS DOWN. MEANWHILE...ANOTHER AN UPPER LOW MOVES INTO
THE BASE TO THE WEST TROUGH. THIS LOW NEVER DEEPENS LIKE THE
PREVIOUS ONE...AND FILLS AS IT CROSSES THE PLAINS ON WEDNESDAY.
AT THE SURFACE...THE COLD FRONT OVER THE OH RIVER VALLEY SUNDAY
MORNING IS EXPECTED TO PUSH SOUTH O THE CAROLINAS BY MONDAY AS HIGH
PRESSURE OVER CANADA EXTENDS SOUTH ALONG THE EAST COAST. MEANWHILE
GULF INFLOW AHEAD OF A COLD FRONT WILL IMPACT THE GULF STATES. THE
CAROLINA FRONT MOVES SLOWLY NORTH ON TUESDAY...WHILE THE COLD FRONT
TO OUR WEST CROSSES THE GULF STATES...AND GULF INFLOW INCREASES INTO
THE SOUTHERN APPALACHIANS. THE COLD FRONT CROSSES THE MOUNTAINS AND
STALLS OVER THE PIEDMONT ON WEDNESDAY...WHILE GULF MOISTURE
CONTINUES TO SPREAD NE ALONG AND OVER THE BOUNDARY.
ISENTROPIC UPGLIDE AND SOUTHERLY UPSLOPE FLOW WILL BE MAINLY
LIMITED TO MONDAY AHEAD TO THE APPROACHING COLD FRONT. OTHERWISE...
LOW LEVEL FLOW GENERALLY BE FROM THE SE...WITH LITTLE UPGLIDE UP
UPSLOPE COMPONENT. THIS WILL LIMIT PRECIPITATION PRODUCTION...
DESPITE THE PROLONGED NATURE OF MOIST INFLOW. TEMPERATURES WILL
REMAIN ABOVE NORMAL...BUT WITH A DOWNWARD TRENDS AS HEIGHT FALL
ALOFT WITH THE BREAKDOWN OF THE UPPER RIDGE.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AT KCLT...CONTINUED SHRA WILL AFFECT THE AIRFIELD THROUGH THE AFTN
AND EVENING HOURS...BUT WITH TSRA MUCH MORE DIFFICULT TO TIME.
ANTICIPATE MAINLY MVFR CIGS ON S TO SW MIXING WITH OCCASIONAL
GUSTS...AND THEN A RETURN TO IFR THEN LIFR CIGS OVERNIGHT AS THE
MIXING AND RAINFALL LESSEN. PERISTENT SRLY FLOW SHOULD KEEP VSBY
FROM CRASHING DESPITE THE VERY MOIST GROUND. MVFR CIGS/VSBY WILL BE
VERY SLOW TO IMPROVE THROUGH LATE MORNING FRIDAY.
ELSEWHERE...EXPECT CONTINUED FAIRLY WIDESPREAD SHRA ACROSS THE MTN
AND FOOTHILL TAF SITES...BUT WITH CONVECTIVE CHANCES APPEARING TO BE
A BIT LESS. THE LATEST HRRR DOES BRING SOME CONVECTION BACK TONIGHT
WHICH WILL NEED TO BE MONITORED FOR TEMPO TSRA AFTER 05Z.
OTHERWISE...MVFR TO VFR CIGS EARLY WILL RETURN TO IFR THEN LIFR
OVERNIGHT IN THE MOIST SRLY FLOW. UPSLOPE SHRA ARE LIKELY AT TIMES
THROUGH 18Z FRIDAY.
OUTLOOK...DEEP LAYER MOISTURE AHEAD OF A STALLED FRONT WILL PERSIST
OVER AT LEAST THE MOUNTAINS THROUGH LATE FRIDAY...BEFORE SOME MINOR
DRYING OCCURS OVER THE WEEKEND. SRLY UPSLOPE FLOW WILL PERSIST OVER
THE WEEKEND...HOWEVER...WITH SOME RESTRICTIONS ONCE AGAIN LIKELY.
ANOTHER WET SYSTEM WILL APPROACH FROM THE WEST EARLY NEXT WEEK.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT HIGH 94% HIGH 80% HIGH 89% HIGH 84%
KGSP MED 78% HIGH 82% HIGH 90% HIGH 86%
KAVL HIGH 83% HIGH 81% HIGH 88% HIGH 83%
KHKY HIGH 100% MED 64% HIGH 81% HIGH 86%
KGMU HIGH 88% MED 78% MED 78% HIGH 86%
KAND HIGH 90% MED 79% HIGH 87% HIGH 84%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE HOURLY
EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE FORECASTS
ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION
&&
.HYDROLOGY...
ONGOING AND DEVELOPING HYDRO ISSUES WILL BE EXACERBATED BY
ADDITIONAL MODERATE TO HEAVY RAINFALL IN THE EXTREME SOUTHERN
APPALCHIANS TONIGHT INTO FRIDAY. ADDITIONAL QPF OF 1.5 TO 2 INCHES
IS LIKELY IN THE SRN ESCARPMENT AREAS...WITH AMOUNTS FALLING OFF
QUICKLY FARTHER EAST INTO THE PIEDMONT. LOCALLY HEAVY RAINFALL COULD
REDEVELOP JUST ABOUT ANYWHERE WITH SCATTERED CONVECTION...BUT THE NC
MOUNTAINS...GA MTNS...AND IMMEDIATELY ADJACENT FOOTHILLS SHOULD HAVE
THE LONGEST DURATION HYDRO ISSUES THROUGH FRIDAY.
&&
.CLIMATE...
DAILY MAXIMUM TEMPERATURE RECORDS FOR THURSDAY DECEMBER 24...
AVL 72 1955
CLT 71 1982...1931
GSP 71 1964
DAILY MAXIMUM TEMPERATURE RECORDS FOR FRIDAY DECEMBER 25...
AVL 67 1955...1944...1904
CLT 77 1955
GSP 78 1955
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR WEDNESDAY DEC 23...
AVL 59 1990
CLT 63 1990
GSP 61 1990
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR THURSDAY DEC 24...
AVL 54 1932
CLT 56 1891
GSP 55 1931
DAILY HIGH MINIMUM TEMPERATURE RECORDS FOR FRIDAY DEC 25...
AVL 55 1982
CLT 62 1932
GSP 56 1964
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR GAZ010-017-
018-026-028-029.
NC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR NCZ033-
035>037-048>053-056>059-062>065-068>072-082-501>510.
SC...FLASH FLOOD WATCH UNTIL 7 PM EST THIS EVENING FOR SCZ001>014-
019.
&&
$$
SYNOPSIS...JAT
NEAR TERM...HG
SHORT TERM...JAT
LONG TERM...JAT
AVIATION...HG
HYDROLOGY...HG
CLIMATE...JAT
AREA FORECAST DISCUSSION
NWS LUBBOCK TX
1139 AM CST THU DEC 24 2015
.AVIATION...
A COLD FRONT HAS PASSED THROUGH ALL THE TAF SITES WITH NORTH-
NORTHEAST WINDS AROUND 10 TO 15 KTS. THE WINDS WILL SLOWLY COME
AROUND TO THE EAST AND DIMINISH BY EVENING. SOME MID TO UPPER
LEVEL CLOUDINESS IS EXPECTED BUT VFR CONDITIONS WILL CONTINUE FOR
THE NEXT 24 HOURS.
&&
.PREV DISCUSSION... /ISSUED 531 AM CST THU DEC 24 2015/
AVIATION...
A WEAK COLD FRONT PASSING THROUGH THE CENTRAL PANHANDLE WILL PASS
TAF SITES BY MID MORNING WITH MODEST NORTH TO NORTHEAST POST
FRONTAL BREEZES. WINDS MAY BRIEFLY EXCEED 12 KNOTS...ESPECIALLY AT
KCDS. WINDS WILL TURN TO SOUTHEAST LATER TODAY AT BOTH KLBB AND
KPVW. OTHERWISE VFR WITH AN INCREASE IN MID LEVEL MOISTURE
EXPECTED MAINLY OVER KPVW LATER TODAY. LIGHT SHOWER CHANCES SHOULD
REMAIN NORTHWEST OF KPVW. RMCQUEEN
PREV DISCUSSION... /ISSUED 456 AM CST THU DEC 24 2015/
SHORT TERM...
A WEAK COLD FRONT EXTENDING OUT OF THE DISTURBANCE IN EASTERN SOUTH
DAKOTA AND NEBRASKA...AND CROSSING THE PANHANDLE AT THIS TIME...WILL
SPREAD SOUTH ACROSS THE AREA SHORTLY AFTER DAYBREAK. NORTHERLY
BREEZES WILL BE STRONGEST OVER THE NORTHERN ROLLING PLAINS...NEAR 15
MPH LATE THIS MORNING...TRENDING LIGHTER LATER TODAY AND TURNING
SOUTHEAST ON THE CAPROCK. DRIER AIR ALSO WILL SPREAD SOUTH BEHIND
THE FRONT. ALOFT...A VERY ENERGETIC WESTERLY FLOW WILL BACK TO THE
SOUTHWEST AS POTENT STORM ENERGY CROSSES THE NORTHWEST COAST AND
STARTS DEEPENING OVER THE NORTHERN GREAT BASIN TONIGHT. BANDS OF MID
AND UPPER LEVEL MOISTURE WILL CONTINUE OVER OUR AREA TODAY AND
TONIGHT. HRRR SOLUTION AT LEAST TRIES TO BREAK OUT SPRITZY LIGHT
SHOWERS NEAR NORTHWESTERN ZONES LATER TODAY...CHANCES WILL BE SMALL
HOWEVER OWING TO THE DRIER LOWER LEVELS BEHIND THE FRONT MENTIONED
ABOVE. SLIGHTLY COOLER WITH THE FRONT TODAY AND SOME THICKENING OF
MID LEVEL CLOUDS EXPECTED DURING THE DAY...BUT STILL ABOVE NORMAL.
SLIGHTLY COOLER TONIGHT AS WELL YET ALSO STILL ABOVE NORMAL.
RMCQUEEN
LONG TERM...
LIKELIHOOD OF BLIZZARD CONDITIONS AND HEAVY SNOW CONTINUING FOR
LATE WEEKEND...
AFTER ONE MORE ABNORMALLY WARM DECEMBER DAY TO CELEBRATE
CHRISTMAS...INCREASING SOUTHWEST FLOW ALOFT BRINGING THIS WARMUP
WILL BE STERNLY UNDERCUT BY A STRONG COLD FRONT BLASTING SOUTH
ACROSS THE FRONT RANGE AND GREAT PLAINS. GIVEN THE MAGNITUDE OF THE
COLD AIR AHEAD OF A 1040 MB SURFACE RIDGE...WILL IN ALL LIKELIHOOD
SEE THIS BOUNDARY ARRIVE ACROSS THE FAR SOUTHERN TEXAS PANHANDLE BY
DAYBREAK SATURDAY WITH NORTH WINDS QUICKLY ACCELERATING TO 15-25
MPH AFTER SUNRISE. FALLING TEMPERATURES WILL RESULT THROUGHOUT THE
DAY VIA POTENT COLD AIR ADVECTION...WITH READINGS APPROACHING
FREEZING IN THE NORTHWEST BY LATE AFTERNOON. THE WESTERN EXTENT OF
SOME ENHANCED GULF MOISTURE MAY BE ABLE TO HOLD FIRM ACROSS THE
ROLLING PLAINS...SO HAVE THUS MAINTAINED SHOWER MENTION ALONG WITH
A SLIM CHANCE OF A THUNDERSTORM BEFORE THE COLD AIR POURS
IN...ALTHOUGH MAY BE ABLE TO EVENTUALLY PULL THUNDER PENDING THE
SPEED OF THE FRONT.
UPPER LOW DIGGING THROUGH ARIZONA WILL SLOWLY TRAVERSE EASTWARD WITH
DEEP LAYER LIFT INCREASING ACROSS THE WESTERN SOUTH PLAINS HEADING
INTO SATURDAY EVENING. TRENDS CONTINUE FOR THIS SYSTEM TO SLOW AS
IT PUSHES EASTWARD...WHICH IS TYPICAL OF A STORM OF THIS CALIBER.
PRECIPITATION SHOULD BEGIN TO FALL ACROSS THE SOUTH PLAINS AND FAR
SOUTHWEST PANHANDLE AS THE UPPER LEVEL AND ISENTROPIC LIFT
INCREASE SATURDAY EVENING...SPREADING EAST INTO THE OVERNIGHT
HOURS. SNOW LOOKS TO BE THE DOMINANT MODE ACROSS THE TYPICAL
SNOWBELT AT THE ONSET...WHILE A MIX WILL BE FOUND FARTHER SOUTH
AND EAST INITIALLY. RAPID DYNAMIC COOLING COMBINED WITH WET
BULBING SHOULD MEAN MORE SLEET AS OPPOSED TO FREEZING RAIN DURING
THE MIXED PHASE STAGE SATURDAY EVENING/NIGHT...WITH SNOW TAKING
OVER BY DAYBREAK SUNDAY. INSTABILITY AND SATURATION IN THE
DENDRITIC GROWTH LAYER CONTINUE TO LOOK FAVORABLE FOR THE THREAT
OF HEAVY SNOW...WITH AMOUNTS OF AT LEAST 4 INCHES LOOKING LIKE A
GOOD BET. WILL HOLD OFF ON WATCH ISSUANCE FOR ANOTHER PERIOD OR
TWO TO BETTER PINPOINT TIMING AND TRACK OF THE SYSTEM.
THE MAJORITY OF THE SNOW THAT FALLS WILL BE OF THE BLOWING/DRIFTING
VARIETY GIVEN THE PROLONGED PERIOD OF BRISK NORTHERLY WINDS EXPECTED
ON THE NORTH/NORTHWEST QUADRANT OF THE PARENT UPPER LOW. WHILE
TRAVEL IS HIGHLY DISCOURAGED SATURDAY NIGHT THROUGH AT LEAST EARLY
MONDAY...THOSE TRAVELING ON EAST-WEST ORIENTED HIGHWAYS WILL BE AT
GREATER RISK GIVEN THE PERPENDICULAR COMPONENT OF THE WINDS ALLOWING
FOR SNOW TO COVER ROADWAYS.
WIND CHILLS...INCLUDING SINGLE DIGIT AND BELOW ZERO READINGS...WILL
BE ANOTHER ISSUE OF CONCERN WITH TEMPERATURES REMAINING BELOW
FREEZING FROM LATE SATURDAY UNTIL LIKELY TUESDAY AFTERNOON. WIND
SPEEDS OF 25-35 MPH WILL PERSIST FROM SATURDAY NIGHT THROUGH
SUNDAY...WHILE STILL REMAINING ABOVE 20 MPH INTO MONDAY.
SPEED/TRACK OF THE UPPER LOW WILL DETERMINE HOW LONG SNOW PERSISTS INTO
MONDAY...BUT NONETHELESS SHOULD SEE THE SNOW AND WIND TAPER OFF
DURING THE DAY. HOWEVER...TRAVEL WILL STILL BE TREACHEROUS GIVEN
EXPECTED TEMPERATURES BELOW FREEZING AND SUBSEQUENT LACK OF
SNOWMELT. A SERIES OF DISTURBANCES THROUGH NEXT WEEK WILL LEAD TO
A COOL END TO THE YEAR...INCLUDING CRISP NIGHTS WHERE SNOWPACK
REMAINS IN PLACE. TRACK OF THESE SYSTEMS CURRENTLY APPEAR TOO FAR
NORTH TO WARRANT PRECIPITATION MENTION.
AS I SIGN OFF THIS MORNING...I WOULD LIKE TO LET EVERYONE KNOW WHAT
A PLEASURE IT HAS BEEN SERVING THE FOLKS OF THE SOUTH PLAINS REGION.
THANK YOU FOR MAKING MY TIME SPENT IN WEST TEXAS MEMORABLE AND
ENJOYABLE...AND I VERY MUCH LOOK FORWARD TO FUTURE RETURN VISITS. I
WISH ALL OF YOU A VERY MERRY CHRISTMAS AND A HAPPY NEW YEAR!
&&
.LUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1042 AM CST THU DEC 24 2015
.DISCUSSION...
KEEPING THE DENSE FOG ADVISORY UP FOR THE BAYS/NEARSHORE WATERS
FOR THE REST OF TODAY...LIKELY EXTENDING IT INTO MOST OF TOMOR-
ROW. INCREASED ONSHORE WINDS NOT EXPECTED UNTIL EARLY SAT SO WE
COULD SEE LIMITED VISIBILITIES THERE UNTIL THEN. OTHERWISE JUST
SOME TWEAKS WITH THE SHORT TERM POP/WX GRIDS WITH THE UPDATE. A
LOT OF CAPPING NOTED WITH REGIONAL 12Z SOUNDINGS AND NOT SEEING
TOO MUCH BY WAY OF SHORTWAVE ACTIVITY MOVING INTO THE AREA FROM
THE W/SW ATTM. HAVE LOWERED POPS A BIT FOR THIS AFTN/EARLY EVE-
NING AS IT LOOKS LIKE WE WILL NEED SOME TIME FOR THE AIRMASS TO
MOISTEN UP. AS SUCH STARTING TO HAVE SOME DOUBTS REGARDING POPS
FOR TONIGHT...BUT WILL LEAVE THIS AS IS FOR NOW. 41
&&
.PREV DISCUSSION... /ISSUED 744 AM CST THU DEC 24 2015/
UPDATE...
QUICK UPDATE TO EXTEND DENSE FOG ADVISORY NORTHWARD PER LATEST
SATELLITE AND OBSERVATION TRENDS. A WARM FRONT IS QUICKLY LIFTING
NORTH ACROSS THE REGION THIS MORNING... STRETCHING FROM FROM
ROUGHLY NORTHERN AUSTIN COUNTY INTO POLK COUNTY JUDGING BY THE DEW
POINT INCREASES... AND VISIBILITIES HAVE IMPROVED GENERALLY INTO
THE 3 TO 5 MILE RANGE BEHIND THE FRONT. CANCELLED SOUTHERN PORTION
OF DENSE FOG ADVISORY IN RESPONSE. HRRR HAS DONE REMARKABLY WELL
CAPTURING TRENDS THIS MORNING AND EXPECT THE DENSE FOG THREAT TO
BE SHORT LIVED GIVEN THE PROGRESS OF THE FRONT AND TIME OF DAY.
UPDATED PRODUCTS ALREADY OUT.
HUFFMAN
PREV DISCUSSION... /ISSUED 508 AM CST THU DEC 24 2015/
SHORT TERM /CHRISTMAS EVE THROUGH CHRISTMAS/...
GENERALLY QUIET CONDITIONS UNDERWAY EARLY THIS CHRISTMAS EVE
MORNING... WITH THE MAIN WEATHER CONCERN PRESENTLY DENSE FOG
ACROSS PORTION OF THE REGION. INFRARED SATELLITE IMAGERY SHOWS
THIS FOG SLOWLY EXPANDING NORTHWARD FROM THE COAST... WITH
VISIBILITIES FALLING TO LESS THAN ONE MILE. HIGH RESOLUTION
GUIDANCE SHOWS FOG CONTINUING INTO THE MID MORNING HOURS AND
CONCERNED THAT THE ADVISORY MAY NEED TO BE EXTENDED WITH FORECAST
SOUNDINGS NOT SHOWING A STOUT INVERSION LIFTING UNTIL LATE
MORNING. FOR THE MORNING FORECAST... DID EXTEND THE ADVISORY
NORTHWARD TO ROUGHLY A COLUMBUS TO LIVINGSTON LINE BASED ON
SATELLITE TRENDS.
THE REMAINDER OF THE SHORT TERM WILL BE WARM... WITH INCREASING
RAIN CHANCES. ANOTHER A DRY MORNING WILL GIVE WAY TO ISOLATED
SHOWERS THIS AFTERNOON AS A WARM FRONT BEGINS TO LIFT INLAND AND
DEEPER MOISTURE RETURNS TO THE REGION /PRECIPITABLE WATER VALUES
RISING BACK OVER ONE INCH THIS AFTERNOON AND EVENING/. NEAR RECORD
HIGH TEMPERATURES WILL BE POSSIBLE AGAIN TODAY /HIGHS IN THE MID
70S TO NEAR 80/ BUT INCREASING CLOUD COVER IS EXPECTED TO KEEP
SITES A DEGREE OR TWO COOLER THAN YESTERDAY.
FOR TONIGHT... INCREASING DIVERGENCE IN THE SOUTHWEST FLOW ALOFT
WILL RESULT IN SCATTERED THUNDERSTORM DEVELOPMENT LATE TONIGHT
INTO EARLY CHRISTMAS MORNING. THERE IS A MARGINAL RISK THAT SOME
OF THESE STORMS MAY BECOME STRONG TO SEVERE AND CAPABLE OF
DAMAGING WINDS OR LARGE HAIL /ROUGHLY ALONG AND EAST OF A
MADISONVILLE TO HOUSTON LINE/ WITH ENOUGH SHEAR TO PROMOTE STORM
ORGANIZATION /0-6 KM BULK SHEAR AROUND 30 TO 40 KNOTS/. HOWEVER...
OVERALL WEAK FORCING WILL DO A GOOD JOB LIMITING THUNDERSTORM
COVERAGE AND FOR NOW ONLY COVERING THE AREA WITH 30-40 POPS. FOG
DEVELOPMENT... SOME POSSIBLY DENSE... IS ALSO EXPECTED AGAIN
OVERNIGHT AS OVERNIGHT LOWS FALL INTO THE 60S TO NEAR 70.
FOR CHRISTMAS DAY... ISOLATED TO SCATTERED SHOWERS AND
THUNDERSTORMS WILL REMAIN POSSIBLE UNDER MOSTLY CLOUDY SKIES AS
SEVERAL WEAK DISTURBANCES CROSS THE REGION. EXPECT HIGH
TEMPERATURES TO TOP OUT IN THE UPPER 70S.
HUFFMAN
LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
BY FRIDAY NIGHT... A WAVE LOCATED JUST OFF THE PACIFIC NORTHWEST
COAST EARLY THIS MORNING ON WATER VAPOR IMAGERY WILL BEGIN
TRAVELING DOWN THE WEST COAST. THIS WAVE IS EXPECTED TO CUTOFF
OVER THE DESERT SOUTHWEST ON SATURDAY... AND 00Z GUIDANCE HAS COME
INTO BETTER AGREEMENT REGARDING THE TRAJECTORY OF THIS SYSTEM. THE
CANADIAN...GFS...AND EUROPEAN ALL SWING THE UPPER LOW ACROSS
SOUTHWEST TEXAS TO NORTHEAST TEXAS LATE SUNDAY AND CLEAR THE
STATE ON MONDAY.
WHAT HAPPENS DURING THIS TIME IS EXPECTED TO BE A VERY ACTIVE
WEATHER PERIOD FOR SOUTHEAST TEXAS... AND WELL... MOST OF THE
STATE FOR THAT MATTER. AS A LEAD SHORTWAVE EJECTS OUT OF THE
TROUGH OVER THE WESTERN CONUS ACROSS COLORADO ON FRIDAY... IT
WILL DISLODGE A MUCH COLDER AIRMASS... SENDING A COLD FRONT SURGING
INTO TEXAS ON SATURDAY. AT THE SAME TIME... HEIGHT FALLS AHEAD OF
THE UPPER LOW OVER THE SOUTHWEST /ROUGHLY 5 TO 7 DECAMETERS/ ARE
EXPECTED TO INDUCE A SURFACE LOW OVER NORTHERN MEXICO. INCREASING
FORCING AHEAD OF THE UPPER LOW IS EXPECTED TO RESULT IN SCATTERED
SHOWERS AND THUNDERSTORMS ON SATURDAY... SOME OF WHICH COULD BE
STRONG TO SEVERE OVER THE NORTHERN COUNTIES AS THEY DEVELOP ALONG
AN APPROACHING COLD FRONT LATE SATURDAY INTO EARLY SUNDAY. ON SUNDAY...
THE SURFACE LOW OVER MEXICO WILL BE DRAGGED NORTHEAST WITH THE
UPPER LOW WITH A LINE OF STRONG TO SEVERE THUNDERSTORMS POSSIBLY
DEVELOPING ALONG AN ATTENDANT PACIFIC FRONT AND IMPACTING THE
REGION.
WHILE THIS EVENT IS STILL A FEW DAYS OUT... THIS PATTERN
CONTINUES TO REFLECT A SEVERE WEATHER THREAT AND HEAVY
RAIN/FLOODING THREAT FOR MUCH OF THE REGION. ALL SOUTHEAST TEXANS
ARE URGED TO CONTINUE MONITORING THE FORECAST... ESPECIALLY WITH
HOLIDAY TRAVEL POSSIBLE THIS WEEKEND.
DRIER CONDITIONS ARE EXPECTED TO SETTLE IN ACROSS THE REGION FROM
WEST TO EAST ON MONDAY AS THE SYSTEM CLEARS... WITH LITTLE TO NO
RAIN CHANCES EXPECTED THROUGH WEDNESDAY WITH VERY LITTLE MOISTURE
RECOVERY ANTICIPATED. MUCH COOLER AIR IN THE WAKE OF THE FRONT IS
EXPECTED TO DROP LOW TEMPERATURES INTO THE 30S FOR MUCH OF THE
REGION TUESDAY MORNING... WITH BELOW NORMAL TEMPERATURES
CONTINUING THROUGH THE END OF THE FORECAST.
HUFFMAN
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 65 77 70 78 / 10 30 40 50 50
HOUSTON (IAH) 79 68 79 70 77 / 10 40 40 40 50
GALVESTON (GLS) 74 67 73 68 73 / 10 30 40 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...DENSE FOG ADVISORY UNTIL 6 PM CST THIS EVENING FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
SMALL CRAFT SHOULD EXERCISE CAUTION UNTIL 6 PM CST THIS EVENING
FOR THE FOLLOWING ZONES: WATERS FROM FREEPORT TO THE
MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT 20 TO 60 NM.
&&
$$
AN ILLUSTRATED VERSION OF THIS FORECAST DISCUSSION CAN BE SEEN AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND FRIDAY
ISSUED AT 327 PM CST THU DEC 24 2015
LINGERING GUSTY WINDS WILL END DURING THE REST OF THE AFTERNOON
AS THE DEEP STORM SYSTEM WHICH PRODUCED STRONG WINDS OVERNIGHT
MOVES FURTHER NORTHEAST.
WITH THE EXCEPTION OF SOME HOLES IN THE CLOUD COVER FOR AREAS EAST
OF THE FOX RIVER EARLY THIS AFTERNOON...CLOUDS WERE PERSISTENT
ACROSS THE AREA. WHERE LOW LEVEL CLOUDS HAVE SCOURED OVER EAST
CENTRAL WISCONSIN...LOWERING MID LEVEL CLOUDS WILL BE ON THE
INCREASE THIS AFTERNOON AND EVENING AS A WEAK SHORT WAVE TRACKS
FROM IOWA TO SOUTHERN WISCONSIN. THE MODELS ARE IN SOME AGREEMENT
WITH THE NORTHERN FRINGE OF THE LIGHT SNOW BRUSHING OVER PARTS OF
CENTRAL AND EAST CENTRAL WISCONSIN THIS EVENING BEFORE DEPARTING
JUST AFTER MIDNIGHT. HRRR DIMINISHES THIS AREA OF LIGHT SNOW WHILE
WORKING NORTHWARD SO WILL MAINLY GO WITH HIGHER END CHC POPS SOUTH
OF HIGHWAY 10.
SURFACE HIGH PRESSURE REGION AND UPPER REGION BUILDS INTO THE AREA
FRIDAY FOR A QUIET XMAS DAY.
.LONG TERM...FRIDAY NIGHT THROUGH THURSDAY
ISSUED AT 327 PM CST THU DEC 24 2015
THE MAIN CONCERNS DURING THIS PART OF THE FORECAST ARE A COUPLE OF
SYSTEMS WITH THE POTENTIAL TO PRODUCE SEVERAL INCHES OF SNOWFALL
IN THE FORECAST AREA. THE FIRST ARRIVES LATE FRIDAY NIGHT AND THE
NEXT LOOKS TO BE EARLY IN THE UPCOMING WORK WEEK.
MODELS ONCE AGAIN SHOWED A STRONG UPPER JET STREAK NORTH OF
WISCONSIN. UPPER LEVEL DIVERGENCE ASSOCIATED WITH THE JET WILL
ASSIST AN APPROACHING MID LEVEL SHORT WAVE TROUGH IN DEVELOPING
SNOW ACROSS NORTHERN WISCONSIN FRIDAY NIGHT AND SATURDAY. HIGHEST
QPF VALUES WERE FORECAST IN THE NORTH AND THERE MAY BE SEVERAL
INCHES OF SNOW BEFORE THINGS WIND DOWN SATURDAY EVENING. MOST OF
THE 12Z MODELS SHOWED ONE LARGE AREA OF QPF DEVELOPING...THE NAM
KEPT TWO SEPARATE AREAS...AS A SURFACE LOW MOVING ALONG A COLD
FRONT ENTERS THE REGION. PRECIPITATION AMOUNTS SHOULD BE LIGHTER
BETWEEN THE TWO MAXIMA AND SOME WILL FALL AS RAIN IN PARTS OF
EASTERN WISCONSIN. SO...SNOWFALL NUMBERS ARE RATHER QUESTIONABLE
IN CENTRAL AND EASTERN WISCONSIN. SURFACE HIGH PRESSURE BUILDING
INTO THE AREA WILL KEEP A CHANCE FOR LAKE EFFECT SNOW SHOWERS IN
FAR NORTH CENTRAL WISCONSIN THROUGH AT LEAST SUNDAY.
SURFACE AND 500MB LOWS MOVING FROM THE PLAINS TO THE GREAT LAKES
REGION COULD BRING SIGNIFICANT SNOWFALL TO THE AREA...BUT THERE IS
TOO MUCH DISAGREEMENT AMONG THE MODELS TO GO WITH ANYTHING HIGHER
THAN A CHANCE FOR SNOW ON MONDAY NIGHT AND TUESDAY. THE 12Z
CANADIAN-NH BRINGS LITTLE OR NO PRECIPITATION TO THE AREA AT
ALL...WHILE THE ECMWF HAD MORE THAN 0.50 INCH OF QPF IN THE
SOUTHERN PART OF THE AREA. THE GFS LOOKED MORE SIMILAR TO THE
CANADIAN THAN TO THE EC. WILL HAVE TO KEEP A CLOSE WATCH ON THE
SYSTEM.
TEMPERATURES WILL BE ABOVE NORMAL FOR THIS TIME OF YEAR...BUT NOT
NEARLY AS WARM AS THEY HAVE BEEN IN THE RECENTLY.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1131 AM CST THU DEC 24 2015
MAINLY MVFR CONDITIONS TODAY INTO TONIGHT. A PERIOD OF VFR CIGS
MAY LINGER OVER EAST CENTRAL WISCONSIN THIS AFTERNOON...BUT A
WEAK UPPER SYSTEM TRACKING OVER SOUTHERN WISCONSIN TONIGHT WILL
RETURN CIGS TO MVFR...WITH PATCHY MVFR VSBYS DUE TO SNOW FOR THE
ATW AND MTW TAFS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM.....TDH
LONG TERM......MG
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
315 PM CST THU DEC 23 2015
.TONIGHT AND FRIDAY - CONFIDENCE...MEDIUM.
MODELS GENERALLY IN GOOD AGREEMENT IN DIMINISHING AREA OF UPSTREAM
SNOW AS IT APPROACHES THE FROM THE SOUTHWEST BY LATE AFTERNOON. MOST
MODELS INDICATE BEST CHANCE FOR ANY VERY LIGHT ACCUMULATIONS THIS
EVENING WOULD BE ACROSS THE NORTHWEST FORECAST AREA AS A SHORTWAVE
PUSHES THROUGH. LATEST NAM AND HRRR ARE SHOWING SOME ADDITIONAL
DEVELOPMENT LATE EVENING...THOUGH DEEPER MOISTURE IS DEPARTING AT
THAT TIME. COULD BE SOME DRIZZLE MIXED IN THERE IF SATURATION IS NOT
DEEP ENOUGH FOR ICE CRYSTAL FORMATION. ANY LINGERING PRECIP SHOULD
EXIT THE EAST BY AROUND 3 AM...WITH DECREASING CLOUDS TOWARD
DAYBREAK AS HIGH PRESSURE BUILDS INTO THE AREA.
HIGH PRESSURE WILL THEN BRING DRY WEATHER AND A FAIR AMOUNT OF
SUNSHINE FRIDAY...WITH HIGH TEMPERATURES REMAINING ABOVE NORMAL IN
THE UPPER 30S TO LOW 40S.
.FRIDAY NIGHT THROUGH SUNDAY - FORECAST CONFIDENCE...LOW TO MEDIUM.
DRIER EASTERLY FLOW AND LINGERING SHORT WAVE RIDGING WILL SLOW DOWN
THREAT OF LIGHT PRECIPITATION SPREADING BACK INTO SRN WI. HENCE WL
REMOVE POPS FOR MOST OF FRIDAY NIGHT...BUT KEEP SMALL CHANCE IN THE
WEST WELL AFTER 06Z.
OVER THE NEXT 24 HOURS...UPPER JET AXIS SHIFTS FROM OVER SRN WI TO
NORTHERN WI IN RESPONSE TO AMPLIFYING UPSTREAM LONG-WAVE TROFFING.
SRN WI WILL REMAIN BETWEEN TWO ACTION AREAS ON SATURDAY. ENHANCED
SYNOPTIC FORCING FROM LEFT ENTRANCE REGION OF UPPER JET WL FOCUS TO
THE NORTHWEST OF CWA ACROSS MORE OF SRN MN INTO CENTRAL/NRN WI. IN
ADDITION...THIS AREA WILL EXPERIENCE BETTER LOW LEVEL CONVERGENCE
ALONG TIGHTENING BAROCLINIC ZONE. MEANWHILE...WELL TO THE
SOUTH...STRONG FRONTAL BOUNDARY WILL REMAIN ACTIVE FROM THE OHIO
VALLEY INTO THE CENTRAL MS VALLEY REGION. WEAK LAYER Q-VECTOR
CONVERGENCE DOES PASS ACROSS SRN WI ON SAT AND EXITS THE AREA SAT
NGT. WL CONTINUE HIGHER CHANCE TO LIKELY POPS IN NORTHWEST CWA FOR
LATER FRIDAY NIGHT INTO SATURDAY AS BOTH GFS AND NAM SHOWING
MODERATE ISENTROPIC OMEGA ON 300 THETA SURFACE BRUSHING THIS AREA.
CONDENSATION PRESSURE DEFICITS DECREASE TO LESS THAN 10 MB DURING
THIS TIME. FORECAST SOUNDINGS AND TOP-DOWN APPROACH SHOW POTENTIAL
FOR A PERIOD OF -SN AND -IP INITIALLY...CHANGING OVER TO MOSTLY -RA
IN THE AFTN. 85H TEMPS DROP 10C BY SUN MRNG AS COLDER AIR SETTLES
OVER SRN WI. SOME -RA OR -SN IS POSSIBLE SAT NGT AS REMNANTS OF
UPSTREAM SHORT WAVE TROF MOVE THRU ERN AND SRN WI. BUILDING SHORT
WAVE RIDGING WL RESULT IN MOSTLY DRY AND COLDER CONDITIONS TO FINISH
OFF THE HOLIDAY WEEKEND. WL NEED TO KEEP ONE EYE ON LINGERING LOW
LEVEL MOISTURE AND POTENTIAL LAKE EFFECT LIGHT RAIN OR SNOW SHOWERS
AS DELTA-T INCREASES TO AROUND 11C BEFORE LOW LEVEL WINDS WEAKEN AND
BACK MORE TO THE NORTH. GFS AND NAM FOCUS LOW LEVEL WINDS MORE INTO
NE IL SUN MRNG HOWEVER SO KEPT SUN MRNG DRY ALONG THE LAKE FOR NOW.
.EXTENDED PERIOD...
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE - INITIALLY HIGH
TRENDING TO LOW.
QUIET WEATHER IS EXPECTED TO START THE EXTENDED PERIOD AS THE SHORT
WAVE RIDGING THAT WILL HAVE BUILT INTO THE WESTERN GTLAKES LATER
SUNDAY LINGERS OVER THE WESTERN GTLAKES INTO MONDAY. THE COLDER
TEMPERATURES WILL PERSIST THROUGH THE EXTENDED PERIOD...BUT WILL
STILL BE ABOVE NORMAL FOR LATE DEC. THE QUIETER WEATHER LOOKS TO BE
SHORT-LIVED AS MEDIUM RANGE GUIDANCE IN GOOD AGREEMENT ON CARRYING
SOUTHERN PLAINS SHORT WAVE ON NORTHERLY PATH INTO THE VICINITY OF
THE NRN IL/IN REGION BY 12Z/TUE. HOWEVER ECMWF AND GFS DIVERGE ON
PATH OF WEATHER SYSTEM. ECMWF HAD BEEN TRENDING MORE WEST AND
WARMER OVER EARLIER MODEL RUNS...HOWEVER NEW 12Z DETERMINISTIC RUN
NOW TRENDING FARTHER EAST AND COLDER WITH THIS SYSTEM. CRITICAL
THICKNESSES SHOWING POTENTIAL FOR ICING MON NGT WITH THIS SOLUTION.
GFS AND GEM-NH SHOWING BETTER RUN TO RUN CONSISTENCY WITH COLDER
SOLUTION AND ARE TRENDING FARTHER SOUTH AND EAST...MORE TOWARD NRN
IN WITH LESS EFFECT ON SRN WI. MREF ENSEMBLE BASED ON GFS SHOWS
CONSIDERABLE VARIABILITY WITH SOME OF THE SOLUTIONS TRENDING FARTHER
WEST. WPC BLENDED FIELDS FAVOR 00Z DETERMINISTIC ECMWF AND ECMWF
BLEND WHILE NEW 12Z NH-GEM IS TRENDING TOWARD DRIER GFS. HENCE ALOT
OF UNCERTAINTY AT THIS POINT AND LOW CONFIDENCE IN SOLUTIONS FOR
THIS EARLY WEEK SYSTEM. FOR NOW WL CONTINUE LIKELY WORDING FOR SNOW
IN THE SOUTHEAST CWA WITH A CHANCE FOR SOME SLEET OR RAIN IN THE FAR
SOUTHEAST. NEED BETTER AGREEMENT BEFORE HITTING FREEZING RAIN
THREAT HARDER AT THIS POINT. WL CONTINUE POTENTIAL SNOWFALL
AND MIX MENTION IN HWO.
TUESDAY NIGHT THROUGH THURSDAY...FORECAST CONFIDENCE - MEDIUM.
LOOKS LIKE UNSETTLED CONDITIONS WILL CONTINUE THROUGH MID-WEEK AND
THE END OF THE EXTENDED PERIOD. LINGERING UPSTREAM TROF OVER UPPER
MIDWEST LOOKS TO SEND SEVERAL WEAK SHORT WAVES ACROSS THE WESTERN
GTLAKES DURING THE PERIOD. COLDER...MORE SEASONAL CONDITIONS SHOULD
SETTLE INTO THE REGION EARLY NEXT WEEK SO MAY BE ABLE TO FINALLY
BUILD UP SOME SNOW COVER.
&&
.AVIATION/00Z TAFS/...
WILL LIKELY SEE A LITTLE SNOW THIS EVENING...MAINLY ACROSS THE
NORTHWEST HALF OF THE FORECAST AREA AS A SHORTWAVE MOVES THROUGH THE
AREA. SNOW TOTALS LOOK LIKE A DUSTING TO A COUPLE TENTHS OF AN INCH
AT BEST. LATEST HRRR AND NAM DO SHOW SOME ADDITIONAL DEVELOPMENT
FARTHER SOUTHEAST BY LATE EVENING...POSSIBLY MIXED WITH DRIZZLE AS
DEEPER MOISTURE IS LOST. ANY LINGERING PRECIP SHOULD EXIT THE EAST
BY AROUND 09Z. THE SHORTWAVE WILL LIKELY BRING SOME LOWER CIGS FOR A
TIME...WITH VFR CONDITIONS RETURNING FOR FRIDAY UNDER HIGH PRESSURE.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...NONE.
$$
TONIGHT AND FRIDAY/AVIATION...DDV
FRIDAY NIGHT THROUGH THURSDAY...MBK