Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/20/13
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1013 PM EST TUE NOV 19 2013
.SYNOPSIS...
LARGE HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT AND
WEDNESDAY WITH CONTINUED COLD TEMPERATURES. A FRONTAL SYSTEM WILL
PROBABLY BRING SOME RAIN SHOWERS FRIDAY NIGHT/SATURDAY
MORNING...FOLLOWED BY BLUSTERY AND UNSEASONABLY COLD WEATHER SUNDAY
INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
HIGH PRESSURE CENTERED OVER THE EASTERN GREAT LAKES IS BUILDING
INTO NEW ENGLAND. STILL A PRESSURE GRADIENT OVER THE REGION WITH
PRESSURE RISES OF ABOUT 2 MB/3 HOURS. TEMPERATURES FALLING BUT A
LITTLE SLOWER THAN FORECAST...PROBABLY DUE TO THE STILL-MOVING
AIR.
EXPECTATION IS FOR THE GRADIENT TO RELAX AFTER MIDNIGHT ESPECIALLY
OVER THE BERKSHIRES/CT VALLEY AREAS. FARTHER EAST THE GRADIENT
SHOULD REMAIN UP THROUGH THE NIGHT.
WE HAVE ADJUSTED TEMPS UP A COUPLE OF DEGREES IN SEVERAL SPOTS
BASED ON OBSERVATION BUT MAINTAIN A SLOW FALL OVERNIGHT WITH
SIMILAR MIN TEMPS BY MORNING. WIND FORECASTS HAVE BEEN FRESHED
WITH 00Z OUTPUT FROM THE HRRR AND RAP MODELS. OTHERWISE A QUIET
NIGHT WITH MIN TEMPS IN THE UPPER TEENS NORTHWEST AND 20S MOST
OTHER PLACES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...
LARGE HIGH PRESSURE WILL BE CENTERED ACROSS SOUTHERN NEW ENGLAND.
WHILE WE WILL SEE PLENTY OF SUNSHINE...THE LOW NOVEMBER SUN
ANGLE/LIMITED MIXING AND COLD START WILL KEEP TEMPS IN CHECK.
AFTERNOON HIGHS SHOULD ONLY RECOVER INTO THE UPPER 30S ACROSS THE
INTERIOR HIGH TERRAIN...TO THE LOWER TO MIDDLE 40S ELSEWHERE. WINDS
WILL BE LIGHTER THAN TODAY...SO WILL NOT FEEL QUITE AS CHILLY IN THE
AFTERNOON.
WEDNESDAY NIGHT...
HIGH PRESSURE WILL REMAIN OVERHEAD ALLOWING FOR A GOOD NIGHT OF
RADIATIONAL COOLING. EXPECT MOSTLY CLEAR TO PARTLY CLOUDY SKIES
WITH JUST SOME HIGH THIN CLOUDS WORKING INTO THE REGION DURING
OVERNIGHT HOURS. EXPECT A WIDE RANGE IN OVERNIGHT LOW TEMPS. LOWS
SHOULD RANGE FROM THE MIDDLE TEENS ACROSS THE NORMALLY COLDEST
OUTLYING LOCATIONS OF SOUTHWEST NH/NORTHWEST MA...TO THE UPPER 20S
AND LOWER 30S IN THE URBAN HEAT ISLANDS OF BOSTON/PROVIDENCE
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* CO0L AND DRY WEATHER THURSDAY INTO FRI
* FRONTAL SYSTEM WITH RAIN POSSIBLE FRI NIGHT INTO SAT
* BLUSTERY AND MUCH COLDER EARLY NEXT WEEK
CONFIDENCE LEVEL/MODEL GUIDANCE...
COMPLICATED LONG TERM FORECAST WITH SEVERAL DIFFERENT
SOLUTIONS...THEREFORE HAVE A MODERATE CONFIDENCE ON THE OVERALL
FORECAST. HAVE HIGH CONFIDENCE IN UPCOMING COLD SPELL FOR EARLY
NEXT WEEK AS WELL AS SOME PRECIP FOR THE FRIDAY NIGHT INTO
SATURDAY TIMEFRAME. HIGH UNCERTAINTY ON PRECIP FOR SUNDAY NIGHT AS
WELL AS THE TUES/WED TIMEFRAME OF NEXT WEEK.
12Z MODEL GUIDANCES HAS COME MORE IN-LINE FOR THE MEDIUM RANGE.
HOWEVER THERE IS STILL A HIGH SPREAD IN GUIDANCE FOR THE LONG
TERM. THE 12Z EC HAS SPED UP WITH THE 12Z GFS AND IS BETTER IN-
LINE FOR THE TIMING OF THE FRONTAL SYSTEM AND PRECIP. BOTH MODELS
AS WELL THE UKMET AND THE ENSEMBLES AGREE TO A MORE INSIDE RUNNER
WITH THE LOW PRESSURE TRACKING INTO QUEBEC...KEEPING SNE ON THE
WARM SIDE AND PRECIP LIQUID. A MAJORITY OF THE MODELS SHOW HEIGHTS
FALL QUICKLY ONCE THE FRONT MOVES OFFSHORE DROPPING TEMPS WELL
BELOW AVG BEGINNING SUNDAY LASTING INTO THE MID-WEEK. A FEW OF
THE GFS ENSEMBLE MEMBERS AND THE DETERMINISTIC EC SHOW A QUICK
MOVING SHORTWAVE THROUGH THE NW FLOW WHICH COULD SPROUT SOME SNOW
SHOWERS ACROSS SNE ESP SOUTH OF THE MASS PIKE. LOOKING
AHEAD...THERE IS A WIDE SPREAD IN THE GUIDANCE FOR NEXT WEEK
REGARDING A POSSIBLE SYSTEM MOVING UP THE COAST. THIS IS SUPPORTED
BY THE DETERMINISTIC EC YET THE EC ENSEMBLES SUPPORT IT FARTHER
SOUTH WITH NO SUPPORT FROM THE GFS AND THE GFS ENSEMBLE. WITH THIS
EVENT 7/8 DAYS OUT...HAVE VERY LOW CONFIDENCE BUT MAY NEED TO
WATCH AS LATEST MODEL RUNS COME IN.
DETAILS...
THURSDAY INTO FRIDAY...
HIGH PRESSURE WILL DOMINATE THIS TIME FRAME KEEPING THE WEATHER
DRY. FORECAST TEMPS WILL RANGE FROM THE MID 40S TO LOW 50S FOR
BOTH DAYS WITH FRIDAY BEING THE WARMER DAY THANKS TO 850 MB TEMPS
WARMING TO 4C. CLOUD COVER WILL BE GENERALLY INCREASE THROUGHOUT
THE DAY BEFORE BECOMING MOSTLY CLOUDY BY FRIDAY AHEAD OF
APPROACHING SYSTEM.
FRIDAY NIGHT INTO SATURDAY...
PRECIP WILL BEGIN TO OVERSPREAD THE REGION EARLY FRIDAY EVENING
FROM THE WEST AND MOVE ACROSS SNE BY SATURDAY MORNING. GENERAL
MODEL CONSISTENCY SHOWS THIS IS THE BEST TIME FRAME FOR PRECIP.
SINCE THIS IS STILL 4/5 DAYS AWAY THE SYSTEM CAN SPEED UP OR SLOW
DOWN...BUT HAVE HIGH CONFIDENCE THAT PRECIP WILL OCCUR FRIDAY
NIGHT AND EARLY SATURDAY MORNING. THEREFORE HAVE HIGH END CHANCE
POPS FOR NOW. EXPECT LIKELY TO BE INTRODUCE BY THE NEXT SHIFT IF
MODELS CONTINUE TO AGREE. THE EC IS A TAD SLOWER ON PUSHING THE
PRECIP OUT BUT REGARDLESS LOOKS LIKE BY THE EVENING ON SATURDAY
THE REGION SHOULD BE CLEARING OUT AS A GOOD AMOUNT OF DRY AIR
PUSHES INTO THE AREA. MOST OF THE PRECIP WILL BE IN LIQUID FORM
AS WE ARE IN THE WARM SECTOR...HOWEVER ON THE BACKSIDE OF THE
SYSTEM...THERE COULD BE A FEW FLAKES/SNOW SHOWERS POSSIBLE. STILL
SOME UNCERTAINTY ON THE THERMAL FIELDS.
SUNDAY INTO MONDAY NIGHT...
VERY COLD AIRMASS WILL BE IN PLACE ACROSS THE REGION BY SUNDAY.
850 MB TEMPS DROP DOWN TO -18C. THIS WILL PUSH TEMPS AROUND 15
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. THERE IS A POSSIBILITY
FOR A WAVE TO MOVE THROUGH THE NW FLOW ALLOWING FOR SOME SNOW
SHOWERS TO DEVELOP BY SUNDAY NIGHT. YET THERE IS A LOW
PROBABILITY THAT THIS MAY OCCUR. OVERALL EXPECT ANOMALOUS COLD
TEMPERATURES SUNDAY INTO MONDAY WITH BLUSTERY CONDITIONS.
TUESDAY AND BEYOND...
AS MENTIONED ABOVE THERE IS HIGH UNCERTAINTY WITH THIS PORTION OF
THE FORECAST AS BOTH MODEL GUIDANCE AND THE ENSEMBLES ARE NOT IN
AGREEMENT. HOWEVER WITH THIS APPROACHING A BUSY TRAVEL TIME...IT
NEEDS TO BE WATCHED CLOSELY. FOR NOW KEPT A CHANCE POPS ACROSS THE
EASTERN HALF OF THE REGION TO ACCOUNT FOR A POSSIBILITY FOR A
COASTAL SYSTEM MOVING UP THE EASTERN SEABOARD LATE TUESDAY INTO
WEDNESDAY. IF THIS DOES PAN OUT THEN A THE PRECIP WOULD MAINLY BE
IN THE FORM OF SNOW RATHER THEN RAIN...HOWEVER IT IS STILL TO
DIFFICULT TO EXACTLY PINPOINT THE THERMAL FIELDS AND WHERE THE
HEAVIEST PRECIP WILL OCCUR. WOULD LIKE TO SEE BETTER MODEL
ALIGNMENT FOR THIS TIMEFRAME.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH WEDNESDAY NIGHT. THERE IS
A LOW PROBABILITY THAT OCEAN EFFECT CLOUDINESS COULD RESULT IN BRIEF
MVFR CIGS ACROSS HYA/ACK LATE TONIGHT/WED MORNING. HOWEVER...FEEL
THEY WILL GENERALLY REMAIN EAST OF THOSE TERMINALS.
OTHERWISE...NORTHWEST WIND GUSTS OF 25 TO 30 KNOTS DIMINISH
OVERNIGHT BUT WILL PERSIST A BIT LONGER IN THE TYPICALLY PRONE
COASTAL LOCATIONS.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...THURSDAY THROUGH SUNDAY.
THU AND FRI...HIGH CONFIDENCE. VFR. SOME LOWER CIGS/LATE NIGHT FOG
POSSIBLE THU NIGHT INTO FRI.
FRI NIGHT INTO SAT...MODERATE CONFIDENCE. AREAS OF MVFR/IFR
POSSIBLE IN RAIN AND FOG.
SUN...MODERATE CONFIDENCE. LINGERING MVFR IN LEFT OVER SNOW/RAIN
SHOWERS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
TONIGHT... COLD ADVECTION OVER THE OCEAN SHOULD ALLOW NORTHWEST SCA
WIND GUSTS OF 25 TO 30 KNOTS TO CONTINUE WELL INTO THE OVERNIGHT
HOURS OVER THE OPEN WATERS. THE AIRPORT AT PROVINCETOWN REPORTED
A GUST TO 34 KNOTS DURING THE EVENING. AN ISOLATED GUST TO THIS
SPEED IS POSSIBLE OVERNIGHT.
WINDS AT LOGAN AIRPORT ARE DIMINISHING...ENOUGH TO GO WITH A
CHANGE OF PLAN...WE WILL END THE BOSTON SCA WITH THIS PACKAGE.
WEDNESDAY AND WEDNESDAY NIGHT...WINDS SHOULD FINALLY DIMINISH BELOW
SCA LEVELS ACROSS ALL OPEN WATERS BY AFTERNOON AS HIGH PRESSURE
BUILDS IN FROM THE WEST. SEAS WILL ALSO CONTINUE TO DIMINISH...BUT
SHOULD REMAIN AT SCA LEVELS ACROSS THE EASTERN ATLANTIC WATERS RIGHT
THROUGH WED NIGHT GIVEN NORTH TO NORTHEAST WINDS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THU INTO FRI...HIGH CONFIDENCE. A PERIOD OF GENERALLY QUIET BOATING
WEATHER IS EXPECTED AS HIGH PRES BUILDS OVER THE WATERS.
FRIDAY NIGHT INTO SAT...MODERATE CONFIDENCE.
A COLD FRONT APPROACHES THE WATERS FROM THE W. SOME S-SW FLOW MAY
LEAD TO SEAS BUILDING ABOVE 5 FT OVERNIGHT AND EXPAND ACROSS MOST
OF THE WATERS BY THE DAY. SMALL CRAFT ADVISORIES WILL BE NEEDED.
SATURDAY NIGHT INTO SUNDAY...MODERATE CONFIDENCE. VERY STRONG COLD
AIRMASS WILL MOVE OVER THE WATERS INCREASING MIXING
POTENTIAL. EXPECT THE POTENTIAL FOR WNW GALES BEGINNING LATE SAT
NIGHT LASTING WELL INTO SUNDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR ANZ231>235-
237-251.
SMALL CRAFT ADVISORY UNTIL 4 AM EST THURSDAY FOR ANZ250-254-
255.
SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR ANZ256.
&&
$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...WTB/FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...WTB/FRANK/DUNTEN
MARINE...WTB/FRANK/DUNTEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
958 PM EST TUE NOV 19 2013
.SYNOPSIS...
LARGE HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT AND
WEDNESDAY WITH CONTINUED COLD TEMPERATURES. A FRONTAL SYSTEM WILL
PROBABLY BRING SOME RAIN SHOWERS FRIDAY NIGHT/SATURDAY
MORNING...FOLLOWED BY BLUSTERY AND UNSEASONABLY COLD WEATHER SUNDAY
INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
HIGH PRESSURE CENTERED OVER THE EASTERN GREAT LAKES IS BUILDING
INTO NEW ENGLAND. STILL A PRESSURE GRADIENT OVER THE REGION WITH
PRESSURE RISES OF ABOUT 2 MB/3 HOURS. TEMPERATURES FALLING BUT A
LITTLE SLOWER THAN FORECAST...PROBABLY DUE TO THE STILL-MOVING
AIR.
EXPECTATION IS FOR THE GRADIENT TO RELAX AFTER MIDNIGHT ESPECIALLY
OVER THE BERKSHIRES/CT VALLEY AREAS. FARTHER EAST THE GRADIENT
SHOULD REMAIN UP THROUGH THE NIGHT.
WE HAVE ADJUSTED TEMPS UP A COUPLE OF DEGREES IN SEVERAL SPOTS
BASED ON OBSERVATION BUT MAINTAIN A SLOW FALL OVERNIGHT WITH
SIMILAR MIN TEMPS BY MORNING. WIND FORECASTS HAVE BEEN FRESHED
WITH 00Z OUTPUT FROM THE HRRR AND RAP MODELS. OTHERWISE A QUIET
NIGHT WITH MIN TEMPS IN THE UPPER TEENS NORTHWEST AND 20S MOST
OTHER PLACES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...
LARGE HIGH PRESSURE WILL BE CENTERED ACROSS SOUTHERN NEW ENGLAND.
WHILE WE WILL SEE PLENTY OF SUNSHINE...THE LOW NOVEMBER SUN
ANGLE/LIMITED MIXING AND COLD START WILL KEEP TEMPS IN CHECK.
AFTERNOON HIGHS SHOULD ONLY RECOVER INTO THE UPPER 30S ACROSS THE
INTERIOR HIGH TERRAIN...TO THE LOWER TO MIDDLE 40S ELSEWHERE. WINDS
WILL BE LIGHTER THAN TODAY...SO WILL NOT FEEL QUITE AS CHILLY IN THE
AFTERNOON.
WEDNESDAY NIGHT...
HIGH PRESSURE WILL REMAIN OVERHEAD ALLOWING FOR A GOOD NIGHT OF
RADIATIONAL COOLING. EXPECT MOSTLY CLEAR TO PARTLY CLOUDY SKIES
WITH JUST SOME HIGH THIN CLOUDS WORKING INTO THE REGION DURING
OVERNIGHT HOURS. EXPECT A WIDE RANGE IN OVERNIGHT LOW TEMPS. LOWS
SHOULD RANGE FROM THE MIDDLE TEENS ACROSS THE NORMALLY COLDEST
OUTLYING LOCATIONS OF SOUTHWEST NH/NORTHWEST MA...TO THE UPPER 20S
AND LOWER 30S IN THE URBAN HEAT ISLANDS OF BOSTON/PROVIDENCE
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* CO0L AND DRY WEATHER THURSDAY INTO FRI
* FRONTAL SYSTEM WITH RAIN POSSIBLE FRI NIGHT INTO SAT
* BLUSTERY AND MUCH COLDER EARLY NEXT WEEK
CONFIDENCE LEVEL/MODEL GUIDANCE...
COMPLICATED LONG TERM FORECAST WITH SEVERAL DIFFERENT
SOLUTIONS...THEREFORE HAVE A MODERATE CONFIDENCE ON THE OVERALL
FORECAST. HAVE HIGH CONFIDENCE IN UPCOMING COLD SPELL FOR EARLY
NEXT WEEK AS WELL AS SOME PRECIP FOR THE FRIDAY NIGHT INTO
SATURDAY TIMEFRAME. HIGH UNCERTAINTY ON PRECIP FOR SUNDAY NIGHT AS
WELL AS THE TUES/WED TIMEFRAME OF NEXT WEEK.
12Z MODEL GUIDANCES HAS COME MORE IN-LINE FOR THE MEDIUM RANGE.
HOWEVER THERE IS STILL A HIGH SPREAD IN GUIDANCE FOR THE LONG
TERM. THE 12Z EC HAS SPED UP WITH THE 12Z GFS AND IS BETTER IN-
LINE FOR THE TIMING OF THE FRONTAL SYSTEM AND PRECIP. BOTH MODELS
AS WELL THE UKMET AND THE ENSEMBLES AGREE TO A MORE INSIDE RUNNER
WITH THE LOW PRESSURE TRACKING INTO QUEBEC...KEEPING SNE ON THE
WARM SIDE AND PRECIP LIQUID. A MAJORITY OF THE MODELS SHOW HEIGHTS
FALL QUICKLY ONCE THE FRONT MOVES OFFSHORE DROPPING TEMPS WELL
BELOW AVG BEGINNING SUNDAY LASTING INTO THE MID-WEEK. A FEW OF
THE GFS ENSEMBLE MEMBERS AND THE DETERMINISTIC EC SHOW A QUICK
MOVING SHORTWAVE THROUGH THE NW FLOW WHICH COULD SPROUT SOME SNOW
SHOWERS ACROSS SNE ESP SOUTH OF THE MASS PIKE. LOOKING
AHEAD...THERE IS A WIDE SPREAD IN THE GUIDANCE FOR NEXT WEEK
REGARDING A POSSIBLE SYSTEM MOVING UP THE COAST. THIS IS SUPPORTED
BY THE DETERMINISTIC EC YET THE EC ENSEMBLES SUPPORT IT FARTHER
SOUTH WITH NO SUPPORT FROM THE GFS AND THE GFS ENSEMBLE. WITH THIS
EVENT 7/8 DAYS OUT...HAVE VERY LOW CONFIDENCE BUT MAY NEED TO
WATCH AS LATEST MODEL RUNS COME IN.
DETAILS...
THURSDAY INTO FRIDAY...
HIGH PRESSURE WILL DOMINATE THIS TIME FRAME KEEPING THE WEATHER
DRY. FORECAST TEMPS WILL RANGE FROM THE MID 40S TO LOW 50S FOR
BOTH DAYS WITH FRIDAY BEING THE WARMER DAY THANKS TO 850 MB TEMPS
WARMING TO 4C. CLOUD COVER WILL BE GENERALLY INCREASE THROUGHOUT
THE DAY BEFORE BECOMING MOSTLY CLOUDY BY FRIDAY AHEAD OF
APPROACHING SYSTEM.
FRIDAY NIGHT INTO SATURDAY...
PRECIP WILL BEGIN TO OVERSPREAD THE REGION EARLY FRIDAY EVENING
FROM THE WEST AND MOVE ACROSS SNE BY SATURDAY MORNING. GENERAL
MODEL CONSISTENCY SHOWS THIS IS THE BEST TIME FRAME FOR PRECIP.
SINCE THIS IS STILL 4/5 DAYS AWAY THE SYSTEM CAN SPEED UP OR SLOW
DOWN...BUT HAVE HIGH CONFIDENCE THAT PRECIP WILL OCCUR FRIDAY
NIGHT AND EARLY SATURDAY MORNING. THEREFORE HAVE HIGH END CHANCE
POPS FOR NOW. EXPECT LIKELY TO BE INTRODUCE BY THE NEXT SHIFT IF
MODELS CONTINUE TO AGREE. THE EC IS A TAD SLOWER ON PUSHING THE
PRECIP OUT BUT REGARDLESS LOOKS LIKE BY THE EVENING ON SATURDAY
THE REGION SHOULD BE CLEARING OUT AS A GOOD AMOUNT OF DRY AIR
PUSHES INTO THE AREA. MOST OF THE PRECIP WILL BE IN LIQUID FORM
AS WE ARE IN THE WARM SECTOR...HOWEVER ON THE BACKSIDE OF THE
SYSTEM...THERE COULD BE A FEW FLAKES/SNOW SHOWERS POSSIBLE. STILL
SOME UNCERTAINTY ON THE THERMAL FIELDS.
SUNDAY INTO MONDAY NIGHT...
VERY COLD AIRMASS WILL BE IN PLACE ACROSS THE REGION BY SUNDAY.
850 MB TEMPS DROP DOWN TO -18C. THIS WILL PUSH TEMPS AROUND 15
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. THERE IS A POSSIBILITY
FOR A WAVE TO MOVE THROUGH THE NW FLOW ALLOWING FOR SOME SNOW
SHOWERS TO DEVELOP BY SUNDAY NIGHT. YET THERE IS A LOW
PROBABILITY THAT THIS MAY OCCUR. OVERALL EXPECT ANOMALOUS COLD
TEMPERATURES SUNDAY INTO MONDAY WITH BLUSTERY CONDITIONS.
TUESDAY AND BEYOND...
AS MENTIONED ABOVE THERE IS HIGH UNCERTAINTY WITH THIS PORTION OF
THE FORECAST AS BOTH MODEL GUIDANCE AND THE ENSEMBLES ARE NOT IN
AGREEMENT. HOWEVER WITH THIS APPROACHING A BUSY TRAVEL TIME...IT
NEEDS TO BE WATCHED CLOSELY. FOR NOW KEPT A CHANCE POPS ACROSS THE
EASTERN HALF OF THE REGION TO ACCOUNT FOR A POSSIBILITY FOR A
COASTAL SYSTEM MOVING UP THE EASTERN SEABOARD LATE TUESDAY INTO
WEDNESDAY. IF THIS DOES PAN OUT THEN A THE PRECIP WOULD MAINLY BE
IN THE FORM OF SNOW RATHER THEN RAIN...HOWEVER IT IS STILL TO
DIFFICULT TO EXACTLY PINPOINT THE THERMAL FIELDS AND WHERE THE
HEAVIEST PRECIP WILL OCCUR. WOULD LIKE TO SEE BETTER MODEL
ALIGNMENT FOR THIS TIMEFRAME.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH WEDNESDAY NIGHT. THERE IS
A LOW PROBABILITY THAT OCEAN EFFECT CLOUDINESS COULD RESULT IN BRIEF
MVFR CIGS ACROSS HYA/ACK LATE TONIGHT/WED MORNING. HOWEVER...FEEL
THEY WILL GENERALLY REMAIN EAST OF THOSE TERMINALS.
OTHERWISE...NORTHWEST WIND GUSTS OF 25 TO 30 KNOTS DIMINISH
OVERNIGHT BUT WILL PERSIST A BIT LONGER IN THE TYPICALLY PRONE
COASTAL LOCATIONS.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...THURSDAY THROUGH SUNDAY.
THU AND FRI...HIGH CONFIDENCE. VFR. SOME LOWER CIGS/LATE NIGHT FOG
POSSIBLE THU NIGHT INTO FRI.
FRI NIGHT INTO SAT...MODERATE CONFIDENCE. AREAS OF MVFR/IFR
POSSIBLE IN RAIN AND FOG.
SUN...MODERATE CONFIDENCE. LINGERING MVFR IN LEFT OVER SNOW/RAIN
SHOWERS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
TONIGHT... COLD ADVECTION OVER THE OCEAN SHOULD ALLOW NORTHWEST SCA
WIND GUSTS OF 25 TO 30 KNOTS TO CONTINUE WELL INTO THE OVERNIGHT
HOURS OVER THE OPEN WATERS. THE AIRPORT AT PROVINCETOWN REPORTED
A GUST TO 34 KNOTS DURING THE EVENING. AN ISOLATED GUST TO THIS
SPEED IS POSSIBLE OVERNIGHT.
SCA FOR BOSTON HARBOR IS SCHEDULED TO EXPIRE AT 11 PM. WINDS ARE
BORDERLINE AT LOGAN AIRPORT...BUT STILL QUITE STRONG AT BUOY 013.
WE WILL EXTEND THE BOSTON SCA UNTIL ROUGHLY 4 AM.
WEDNESDAY AND WEDNESDAY NIGHT...WINDS SHOULD FINALLY DIMINISH BELOW
SCA LEVELS ACROSS ALL OPEN WATERS BY AFTERNOON AS HIGH PRESSURE
BUILDS IN FROM THE WEST. SEAS WILL ALSO CONTINUE TO DIMINISH...BUT
SHOULD REMAIN AT SCA LEVELS ACROSS THE EASTERN ATLANTIC WATERS RIGHT
THROUGH WED NIGHT GIVEN NORTH TO NORTHEAST WINDS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THU INTO FRI...HIGH CONFIDENCE. A PERIOD OF GENERALLY QUIET BOATING
WEATHER IS EXPECTED AS HIGH PRES BUILDS OVER THE WATERS.
FRIDAY NIGHT INTO SAT...MODERATE CONFIDENCE.
A COLD FRONT APPROACHES THE WATERS FROM THE W. SOME S-SW FLOW MAY
LEAD TO SEAS BUILDING ABOVE 5 FT OVERNIGHT AND EXPAND ACROSS MOST
OF THE WATERS BY THE DAY. SMALL CRAFT ADVISORIES WILL BE NEEDED.
SATURDAY NIGHT INTO SUNDAY...MODERATE CONFIDENCE. VERY STRONG COLD
AIRMASS WILL MOVE OVER THE WATERS INCREASING MIXING
POTENTIAL. EXPECT THE POTENTIAL FOR WNW GALES BEGINNING LATE SAT
NIGHT LASTING WELL INTO SUNDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR ANZ231>235-
237-251.
SMALL CRAFT ADVISORY UNTIL 4 AM EST WEDNESDAY FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 4 AM EST THURSDAY FOR ANZ250-254-
255.
SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR ANZ256.
&&
$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...WTB/FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...WTB/FRANK/DUNTEN
MARINE...WTB/FRANK/DUNTEN
AREA FORECAST DISCUSSION
NWS TAUNTON MA
956 PM EST TUE NOV 19 2013
.SYNOPSIS...
LARGE HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT AND
WEDNESDAY WITH CONTINUED COLD TEMPERATURES. A FRONTAL SYSTEM WILL
PROBABLY BRING SOME RAIN SHOWERS FRIDAY NIGHT/SATURDAY
MORNING...FOLLOWED BY BLUSTERY AND UNSEASONABLY COLD WEATHER SUNDAY
INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
HIGH PRESSURE CENTERED OVER THE EASTERN GREAT LAKES IS BUILDING
INTO NEW ENGLAND. STILL A PRESSURE GRADIENT OVER THE REGION WITH
PRESSURE RISES OF ABOUT 2 MB/3 HOURS. TEMPERATURES FALLING BUT A
LITTLE SLOWER THAN FORECAST...PROBABLY DUE TO THE STILL-MOVING
AIR.
EXPECTATION IS FOR THE GRADIENT TO RELAX AFTER MIDNIGHT ESPECIALLY
OVER THE BERKSHIRES/CT VALLEY AREAS. FARTHER EAST THE GRADIENT
SHOULD REMAIN UP THROUGH THE NIGHT.
WE HAVE ADJUSTED TEMPS UP A COUPLE OF DEGREES IN SEVERAL SPOTS
BASED ON OBSERVATION BUT MAINTAIN A SLOW FALL OVERNIGHT WITH
SIMILAR MIN TEMPS BY MORNING. WIND FORECASTS HAVE BEEN FRESHED
WITH 00Z OUTPUT FROM THE HRRR AND RAP MODELS. OTHERWISE A QUIET
NIGHT WITH MIN TEMPS IN THE UPPER TEENS NORTHWEST AND 20S MOST
OTHER PLACES.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
WEDNESDAY...
LARGE HIGH PRESSURE WILL BE CENTERED ACROSS SOUTHERN NEW ENGLAND.
WHILE WE WILL SEE PLENTY OF SUNSHINE...THE LOW NOVEMBER SUN
ANGLE/LIMITED MIXING AND COLD START WILL KEEP TEMPS IN CHECK.
AFTERNOON HIGHS SHOULD ONLY RECOVER INTO THE UPPER 30S ACROSS THE
INTERIOR HIGH TERRAIN...TO THE LOWER TO MIDDLE 40S ELSEWHERE. WINDS
WILL BE LIGHTER THAN TODAY...SO WILL NOT FEEL QUITE AS CHILLY IN THE
AFTERNOON.
WEDNESDAY NIGHT...
HIGH PRESSURE WILL REMAIN OVERHEAD ALLOWING FOR A GOOD NIGHT OF
RADIATIONAL COOLING. EXPECT MOSTLY CLEAR TO PARTLY CLOUDY SKIES
WITH JUST SOME HIGH THIN CLOUDS WORKING INTO THE REGION DURING
OVERNIGHT HOURS. EXPECT A WIDE RANGE IN OVERNIGHT LOW TEMPS. LOWS
SHOULD RANGE FROM THE MIDDLE TEENS ACROSS THE NORMALLY COLDEST
OUTLYING LOCATIONS OF SOUTHWEST NH/NORTHWEST MA...TO THE UPPER 20S
AND LOWER 30S IN THE URBAN HEAT ISLANDS OF BOSTON/PROVIDENCE
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* CO0L AND DRY WEATHER THURSDAY INTO FRI
* FRONTAL SYSTEM WITH RAIN POSSIBLE FRI NIGHT INTO SAT
* BLUSTERY AND MUCH COLDER EARLY NEXT WEEK
CONFIDENCE LEVEL/MODEL GUIDANCE...
COMPLICATED LONG TERM FORECAST WITH SEVERAL DIFFERENT
SOLUTIONS...THEREFORE HAVE A MODERATE CONFIDENCE ON THE OVERALL
FORECAST. HAVE HIGH CONFIDENCE IN UPCOMING COLD SPELL FOR EARLY
NEXT WEEK AS WELL AS SOME PRECIP FOR THE FRIDAY NIGHT INTO
SATURDAY TIMEFRAME. HIGH UNCERTAINTY ON PRECIP FOR SUNDAY NIGHT AS
WELL AS THE TUES/WED TIMEFRAME OF NEXT WEEK.
12Z MODEL GUIDANCES HAS COME MORE IN-LINE FOR THE MEDIUM RANGE.
HOWEVER THERE IS STILL A HIGH SPREAD IN GUIDANCE FOR THE LONG
TERM. THE 12Z EC HAS SPED UP WITH THE 12Z GFS AND IS BETTER IN-
LINE FOR THE TIMING OF THE FRONTAL SYSTEM AND PRECIP. BOTH MODELS
AS WELL THE UKMET AND THE ENSEMBLES AGREE TO A MORE INSIDE RUNNER
WITH THE LOW PRESSURE TRACKING INTO QUEBEC...KEEPING SNE ON THE
WARM SIDE AND PRECIP LIQUID. A MAJORITY OF THE MODELS SHOW HEIGHTS
FALL QUICKLY ONCE THE FRONT MOVES OFFSHORE DROPPING TEMPS WELL
BELOW AVG BEGINNING SUNDAY LASTING INTO THE MID-WEEK. A FEW OF
THE GFS ENSEMBLE MEMBERS AND THE DETERMINISTIC EC SHOW A QUICK
MOVING SHORTWAVE THROUGH THE NW FLOW WHICH COULD SPROUT SOME SNOW
SHOWERS ACROSS SNE ESP SOUTH OF THE MASS PIKE. LOOKING
AHEAD...THERE IS A WIDE SPREAD IN THE GUIDANCE FOR NEXT WEEK
REGARDING A POSSIBLE SYSTEM MOVING UP THE COAST. THIS IS SUPPORTED
BY THE DETERMINISTIC EC YET THE EC ENSEMBLES SUPPORT IT FARTHER
SOUTH WITH NO SUPPORT FROM THE GFS AND THE GFS ENSEMBLE. WITH THIS
EVENT 7/8 DAYS OUT...HAVE VERY LOW CONFIDENCE BUT MAY NEED TO
WATCH AS LATEST MODEL RUNS COME IN.
DETAILS...
THURSDAY INTO FRIDAY...
HIGH PRESSURE WILL DOMINATE THIS TIME FRAME KEEPING THE WEATHER
DRY. FORECAST TEMPS WILL RANGE FROM THE MID 40S TO LOW 50S FOR
BOTH DAYS WITH FRIDAY BEING THE WARMER DAY THANKS TO 850 MB TEMPS
WARMING TO 4C. CLOUD COVER WILL BE GENERALLY INCREASE THROUGHOUT
THE DAY BEFORE BECOMING MOSTLY CLOUDY BY FRIDAY AHEAD OF
APPROACHING SYSTEM.
FRIDAY NIGHT INTO SATURDAY...
PRECIP WILL BEGIN TO OVERSPREAD THE REGION EARLY FRIDAY EVENING
FROM THE WEST AND MOVE ACROSS SNE BY SATURDAY MORNING. GENERAL
MODEL CONSISTENCY SHOWS THIS IS THE BEST TIME FRAME FOR PRECIP.
SINCE THIS IS STILL 4/5 DAYS AWAY THE SYSTEM CAN SPEED UP OR SLOW
DOWN...BUT HAVE HIGH CONFIDENCE THAT PRECIP WILL OCCUR FRIDAY
NIGHT AND EARLY SATURDAY MORNING. THEREFORE HAVE HIGH END CHANCE
POPS FOR NOW. EXPECT LIKELY TO BE INTRODUCE BY THE NEXT SHIFT IF
MODELS CONTINUE TO AGREE. THE EC IS A TAD SLOWER ON PUSHING THE
PRECIP OUT BUT REGARDLESS LOOKS LIKE BY THE EVENING ON SATURDAY
THE REGION SHOULD BE CLEARING OUT AS A GOOD AMOUNT OF DRY AIR
PUSHES INTO THE AREA. MOST OF THE PRECIP WILL BE IN LIQUID FORM
AS WE ARE IN THE WARM SECTOR...HOWEVER ON THE BACKSIDE OF THE
SYSTEM...THERE COULD BE A FEW FLAKES/SNOW SHOWERS POSSIBLE. STILL
SOME UNCERTAINTY ON THE THERMAL FIELDS.
SUNDAY INTO MONDAY NIGHT...
VERY COLD AIRMASS WILL BE IN PLACE ACROSS THE REGION BY SUNDAY.
850 MB TEMPS DROP DOWN TO -18C. THIS WILL PUSH TEMPS AROUND 15
DEGREES BELOW NORMAL FOR THIS TIME OF YEAR. THERE IS A POSSIBILITY
FOR A WAVE TO MOVE THROUGH THE NW FLOW ALLOWING FOR SOME SNOW
SHOWERS TO DEVELOP BY SUNDAY NIGHT. YET THERE IS A LOW
PROBABILITY THAT THIS MAY OCCUR. OVERALL EXPECT ANOMALOUS COLD
TEMPERATURES SUNDAY INTO MONDAY WITH BLUSTERY CONDITIONS.
TUESDAY AND BEYOND...
AS MENTIONED ABOVE THERE IS HIGH UNCERTAINTY WITH THIS PORTION OF
THE FORECAST AS BOTH MODEL GUIDANCE AND THE ENSEMBLES ARE NOT IN
AGREEMENT. HOWEVER WITH THIS APPROACHING A BUSY TRAVEL TIME...IT
NEEDS TO BE WATCHED CLOSELY. FOR NOW KEPT A CHANCE POPS ACROSS THE
EASTERN HALF OF THE REGION TO ACCOUNT FOR A POSSIBILITY FOR A
COASTAL SYSTEM MOVING UP THE EASTERN SEABOARD LATE TUESDAY INTO
WEDNESDAY. IF THIS DOES PAN OUT THEN A THE PRECIP WOULD MAINLY BE
IN THE FORM OF SNOW RATHER THEN RAIN...HOWEVER IT IS STILL TO
DIFFICULT TO EXACTLY PINPOINT THE THERMAL FIELDS AND WHERE THE
HEAVIEST PRECIP WILL OCCUR. WOULD LIKE TO SEE BETTER MODEL
ALIGNMENT FOR THIS TIMEFRAME.
&&
.AVIATION /03Z WEDNESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
HIGH CONFIDENCE IN VFR CONDITIONS THROUGH WEDNESDAY NIGHT. THERE IS
A LOW PROBABILITY THAT OCEAN EFFECT CLOUDINESS COULD RESULT IN BRIEF
MVFR CIGS ACROSS HYA/ACK LATE TONIGHT/WED MORNING. HOWEVER...FEEL
THEY WILL GENERALLY REMAIN EAST OF THOSE TERMINALS.
OTHERWISE...NORTHWEST WIND GUSTS OF 25 TO 30 KNOTS DIMINISH
OVERNIGHT BUT WILL PERSIST A BIT LONGER IN THE TYPICALLY PRONE
COASTAL LOCATIONS.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF.
OUTLOOK...THURSDAY THROUGH SUNDAY.
THU AND FRI...HIGH CONFIDENCE. VFR. SOME LOWER CIGS/LATE NIGHT FOG
POSSIBLE THU NIGHT INTO FRI.
FRI NIGHT INTO SAT...MODERATE CONFIDENCE. AREAS OF MVFR/IFR
POSSIBLE IN RAIN AND FOG.
SUN...MODERATE CONFIDENCE. LINGERING MVFR IN LEFT OVER SNOW/RAIN
SHOWERS.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
TONIGHT... COLD ADVECTION OVER THE OCEAN SHOULD ALLOW NORTHWEST SCA
WIND GUSTS OF 25 TO 30 KNOTS TO CONTINUE WELL INTO THE OVERNIGHT
HOURS OVER THE OPEN WATERS. THE AIRPORT AT PROVINCETOWN REPORTED
A GUST TO 34 KNOTS DURING THE EVENING. AN ISOLATED GUST TO THIS
SPEED IS POSSIBLE OVERNIGHT.
SCA FOR BOSTON HARBOR IS SCHEDULED TO EXPIRE AT 11 PM. WINDS ARE
BORDERLINE AT LOGAN AIRPORT...BUT STILL QUITE STRONG AT BUOY 013.
WE WILL EXTEND THE BOSTON SCA UNTIL ROUGHLY 4 AM.
WEDNESDAY AND WEDNESDAY NIGHT...WINDS SHOULD FINALLY DIMINISH BELOW
SCA LEVELS ACROSS ALL OPEN WATERS BY AFTERNOON AS HIGH PRESSURE
BUILDS IN FROM THE WEST. SEAS WILL ALSO CONTINUE TO DIMINISH...BUT
SHOULD REMAIN AT SCA LEVELS ACROSS THE EASTERN ATLANTIC WATERS RIGHT
THROUGH WED NIGHT GIVEN NORTH TO NORTHEAST WINDS.
OUTLOOK...THURSDAY THROUGH SUNDAY...
THU INTO FRI...HIGH CONFIDENCE. A PERIOD OF GENERALLY QUIET BOATING
WEATHER IS EXPECTED AS HIGH PRES BUILDS OVER THE WATERS.
FRIDAY NIGHT INTO SAT...MODERATE CONFIDENCE.
A COLD FRONT APPROACHES THE WATERS FROM THE W. SOME S-SW FLOW MAY
LEAD TO SEAS BUILDING ABOVE 5 FT OVERNIGHT AND EXPAND ACROSS MOST
OF THE WATERS BY THE DAY. SMALL CRAFT ADVISORIES WILL BE NEEDED.
SATURDAY NIGHT INTO SUNDAY...MODERATE CONFIDENCE. VERY STRONG COLD
AIRMASS WILL MOVE OVER THE WATERS INCREASING MIXING
POTENTIAL. EXPECT THE POTENTIAL FOR WNW GALES BEGINNING LATE SAT
NIGHT LASTING WELL INTO SUNDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR ANZ231>235-
237-251.
SMALL CRAFT ADVISORY UNTIL 4 AM EST THIS EVENING FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 4 AM EST THURSDAY FOR ANZ250-254- 255.
SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR ANZ256.
&&
$$
SYNOPSIS...FRANK/DUNTEN
NEAR TERM...WTB/FRANK/DUNTEN
SHORT TERM...FRANK
LONG TERM...DUNTEN
AVIATION...FRANK/DUNTEN
MARINE...FRANK/DUNTEN
AREA FORECAST DISCUSSION
NWS ALBANY NY
536 PM EST MON NOV 18 2013
.SYNOPSIS...
AS COLDER AIR WORKS INTO THE REGION TONIGHT...LAKE ENHANCED RAIN AND
SNOW SHOWERS WILL AFFECT WESTERN AND NORTHERN PARTS OF THE AREA.
TEMPERATURES TOMORROW WILL BE MUCH COLDER THAN RECENT DAYS...WITH A
GUSTY WESTERLY WIND. HIGH PRESSURE PASSING OVER THE AREA WILL ALLOW
FOR DRY WEATHER FOR THE REMAINDER OF THE WORK WEEK...WITH
TEMPERATURES SLOWLY MODERATING BACK TO NORMAL LEVELS.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 530 PM EST...COLD FRONT JUST SLIPPED SOUTH OF I90 PER THE DUAL
POL RADAR DATA. SOME SHOWERS HAVE DEVELOPED ON THE UPSLOPE AREAS OF
THE SCHOHARIE VALLEY AND HELDERBERGS AND WITH THE MEAN WESTERLY
FLOW...THESE ISOLATED SHOWERS HAVE MOVED INTO THE CAPITAL REGION.
FURTHERMORE...TERRAIN ENHANCEMENT ACROSS THE SOUTHERN GREENS HAVE
TOO INITIATED SOME SHOWERS. SO WE WILL INCREASE POPS/WX THROUGH THE
EVENING HOURS AND WATCH LAKE EFFECT ACTIVITY PICK UP DOWNWIND OF
LAKE ONTARIO. PER THE RUC13 LOW LEVEL CONVERGENCE FIELDS...SEEMS
BAND/S/ OF PRECIP SHOULD INCREASE ACROSS CENTRAL HERKIMER COUNTY
WITH A TENDENCY TO SLIDE SOUTHWARD AND WEAKEN OVERNIGHT. THE
CURRENT FORECAST ACROSS THAT PART OF THE CWA REMAINS IN EXCELLENT
SHAPE. OTHERWISE...PER HOURLY TEMPS...DID SLOW DOWN THE NOCTURNAL
CURVE A BIT AND CLOSER TO THE LAMP/LAV AND 2KM HRRR/RUC13.
AS OF 400 PM EST...A STRONG AND VERTICALLY STACKED STORM SYSTEM
OVER WESTERN QUEBEC WILL FILL IN AND WEAKEN OVERNIGHT. WITH THE
TROUGH AXIS CENTERED OVER THE NORTHEASTERN US...THE CYCLONIC FLOW
AROUND THE UPPER LOW WILL PASS OVER THE NORTHERN AND EASTERN GREAT
LAKES. INITIALLY...THE LOW TO MID LEVEL FLOW WILL BE IN A W-SW
DIRECTION...WHICH WILL ALLOW FOR SOME LAKE ENHANCED RAIN AND SNOW
SHOWERS THIS EVENING OVER THE NORTHWESTERN ADIRONDACKS...AS STRONG
CAA DROP 850 HPA TEMPS FROM AROUND 0 TO +4 DEGREES C THIS
AFTN...TO -8 TO -12 DEGREES C BY LATE TONIGHT.
AS BOUNDARY LAYER TEMPS ALSO COOL DOWN...PTYPE WILL CHANGE TO SNOW
ACROSS THE REGION. THE MEAN WIND SHIFTS TO THE WEST DURING THE
OVERNIGHT HOURS AND EVENTUALLY NORTHWEST BY LATE TONIGHT. OUR LOCAL
WFOWRF...AS WELL AS THE LATEST 3KM HRRR...ALL SUGGEST THAT SOME OF
THIS LAKE ENHANCED ACTIVITY WILL PASS ACROSS WESTERN AND NORTHERN
PARTS OF OUR AREA DURING THE OVERNIGHT HOURS. DUE TO THE EXPECTED
AMOUNTS OF SHEAR AND WIND DIRECTION...THE ACTIVITY WILL GENERALLY BE
MULTI-BAND IN NATURE...AND THE INVERSION HEIGHT OF ONLY 2.5-3 KM
WILL PREVENT ANY MEANINGFUL SNOW BANDS FROM OCCURRING.
WHILE THE BULK OF THE ACTIVITY WILL EITHER BY ACROSS THE HIGH
TERRAIN OR THE WESTERN MOHAWK VALLEY...IT/S POSSIBLE THAT A
FLURRY OR SPRINKLE MAY MAKE IT INTO THE HUDSON VALLEY REGION AND
CAPITAL REGION BY LATE TONIGHT. NO SNOW ACCUMULATION IS EXPECTED FOR
THE CAPITAL REGION/HUDSON VALLEY AREAS. ELSEWHERE..SNOW ACCUM WILL
RANGE FROM JUST A DUSTING TO UP TO TWO INCHES ACROSS THE WESTERN
ADIRONDACKS.
TEMPS WILL BE MUCH COLDER FOR TONIGHT THAN RECENT NIGHTS...WITH MINS
RANGING FROM THE MID 20S TO MID 30S. IN ADDITION...THE W-NW SFC
WIND WILL CONTINUE TO BE GUSTY OVERNIGHT...WITH SUSTAINED WINDS OF
10 TO 20 MPH WITH A FEW HIGHER GUSTS...ESP FOR THE MOHAWK VALLEY AND
CAPITAL REGION.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
WITH SFC HIGH PRESSURE BUILDING INTO THE REGION ON TUESDAY AND THE
FLOW ALOFT BECOMING ANTICYCLONIC AND INVERSION HEIGHTS
LOWERING...LAKE EFFECT ACTIVITY WILL END. A FEW SNOW SHOWERS ARE
POSSIBLE EARLY IN THE DAY ACROSS SCHOHARIE COUNTY AND THE EASTERN
CATSKILLS...OTHERWISE IT WILL BE DRY UNDER A PARTLY TO MOSTLY
SUNNY SKY WITH A CONTINUED GUSTY NW BREEZE. TEMPS WILL BE MUCH
COLDER THAN RECENT DAYS...WITH MAX TEMPS IN THE 30S TO MID 40S
ACROSS THE REGION.
AS THE HIGH PRESSURE AREA BUILDS INTO THE REGION FOR TUESDAY
NIGHT...THE WIND WILL DIE OFF AND THIS SHOULD ALLOW FOR GOOD
RADIATIONAL COOLING. TEMPS WILL BE VERY COLD TOMORROW NIGHT...WITH
TEMPS RANGING FROM THE SINGLE DIGITS OVER THE CENTRAL ADIRONDACKS TO
THE TEENS AND LOW 20S ELSEWHERE.
THE HIGH PRESSURE AREA WILL REMAIN SITUATED OVER THE NORTHEAST FOR
WEDNESDAY THROUGH THURSDAY AS WELL...KEEPING THE DRY WEATHER IN
PLACE. MAX TEMPS ON WED WILL BE COLD ONCE AGAIN...WITH 30S AND LOW
40S. HOWEVER...WITH A LIGHT SOUTHERLY WIND DEVELOPING FOR WED NIGHT
AND A FEW MORE CLOUDS ACROSS THE AREA...MIN TEMPS WON/T BE AS COLD
FOR WED NIGHT...WITH 20S OVER THE MAJORITY OF THE AREA. TEMPS WILL
START TO MODERATE ON THURSDAY AS OUR REGION WILL BE IN A RETURN
FLOW AROUND THE SLOWLY DEPARTING HIGH...WITH 40S ACROSS THE ENTIRE
REGION...AND A FEW MORE CLOUDS AROUND...ESP FOR WESTERN PARTS OF
THE AREA.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE PERIOD BEGINS WITH THE PASSAGE OF A COLD FRONT THAT WILL BRING
VERY LITTLE MOISTURE AND THUS LITTLE IN THE WAY OF PRECIPITATION.
BUT LOW PRESSURE STRENGTHENING ALONG THE FRONT OVER THE OHIO VALLEY
ON FRIDAY WILL RAPIDLY BUILD MOISTURE INTO THE REGION. THE LOW WILL
TRACK ALONG THE MID-ATLANTIC REGION AND UP THE NEW ENGLAND COAST
FRIDAY NIGHT AND SATURDAY...A TRAJECTORY WHICH COULD RESULT IN OUR
FIRST SIGNIFICANT WINTER WEATHER EVENT...CONSISTING OF A MIXED BAG
OF PRECIPITATION TYPES.
A WEST TO NORTHWESTERLY FLOW BEHIND THE SYSTEM ON SUNDAY WILL DRAW
IN SIGNIFICANTLY COLDER AIR AND TURN ON THE LAKE EFFECT MACHINE...
WITH A GOOD CHANCE FOR SNOW SHOWERS FROM SATURDAY AFTERNOON THROUGH
SUNDAY. THIS COULD BE WET SNOW FOR THE MID HUDSON VALLEY. WITH THE
FLOW WEAKENING SUNDAY NIGHT...LAKE EFFECT SHOULD BECOME LIMITED TO
THE WESTERN ADIRONDACKS...ALTHOUGH MOST REMAINING LOCATIONS WILL
STILL HAVE A SLIGHT CHANCE OF SEEING SOMETHING. BY MONDAY...THINGS
SHOULD BE QUIETED DOWN AS HIGH PRESSURE RIDGES IN FROM THE SOUTHERN
APPALACHIANS. THERE WILL BE A GOOD MIX OF SUN AND CLOUDS MONDAY...B
UT LITTLE BOUNCE BACK IN TEMPERATURES.
LOWS THURSDAY AND FRIDAY NIGHTS WILL RANGE FROM THE MID OR UPPER 20S
TO THE MID 30S. BEHIND THE WEEKEND STORM SYSTEM...LOWS WILL BE IN
THE UPPER TEENS AND THE 20S SATURDAY NIGHT. THEY WILL RANGE FROM
ONLY AROUND 10 DEGREES IN THE ADIRONDACKS...TO AROUND 20 DEGREES IN
THE MID HUDSON VALLEY SUNDAY NIGHT. HIGH TEMPERATURES WILL RANGE
FROM THE MID 30S IN THE WESTERN ADIRONDACKS...TO AROUND 50 DEGREES
IN THE MID HUDSON VALLEY ON FRIDAY...COOLING TO FROM AROUND 30 TO
THE MID 40S ON SATURDAY...THE LOWER 20S TO MID 30S ON SUNDAY...WITH
A COUPLE OF DEGREES OF BOUNCE BACK IN THE NORTHWESTERN HALF OF THE
FORECAST AREA FOR MONDAY. NORMAL TEMPERATURES FOR ALBANY DURING
THIS PERIOD ARE MID 40S FOR HIGHS AND AROUND 30 FOR LOWS.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS AND BREEZY CONDITIONS WILL PREVAIL THROUGHOUT THE TAF
PERIOD.
THIS AFTERNOON...GENERALLY CLEARING SKIES ARE EXPECTED AT ALL TAF
SITES EXCEPT FOR KGFL...WHERE PERIODIC BROKEN STRATOCUMULUS AROUND 5
KFT WILL REMAIN AS BROAD CYCLONIC FLOW LINGERS ALOFT BEHIND THE EXIT
OF A POWERFUL STORM SYSTEM. WESTERLY WINDS WILL CONTINUE TO BE
BREEZY THIS AFTERNOON AND THROUGH TONIGHT...GENERALLY BETWEEN 10-15
KNOTS WITH OCCASIONAL GUSTS UP TO 25 KNOTS LIKELY.
TONIGHT INTO TUESDAY...A SECONDARY WEAK COLD FRONT WILL SKIRT ACROSS
THE REGION TONIGHT...WITH RELATIVELY LITTLE IMPACT EXCEPT FOR SOME
PASSING CLOUDS. HIGH PRESSURE WILL BEGIN TO BUILD ACROSS THE REGION
FROM THE SOUTH ON TUESDAY WITH CLEARING SKIES...BUT CONTINUED BREEZY
CONDITIONS AS A TIGHT PRESSURE GRADIENT KEEPS NORTHWESTERLY WINDS
BETWEEN 10-20 KNOTS.
OUTLOOK...
TUESDAY NIGHT-THURSDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA...SHSN...RA.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN.
SATURDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF
SHRA...RA...SN...SLEET.
&&
.HYDROLOGY...
NO HYDRO ISSUES ARE EXPECTED OVER THE NEXT FIVE DAYS.
LAKE EFFECT RAIN AND SNOW SHOWERS WILL AFFECT THE ADIRONDACKS AND
MOHAWK VALLEY TONIGHT...WITH UP TO A QUARTER OF AN INCH OF LIQUID
EQUIVALENT PRECIPITATION EXPECTED. THIS PRECIP WILL HAVE LITTLE TO
NO EFFECT ON AREA WATERWAYS. ANY LAKE EFFECT ACTIVITY WILL END ON
TUESDAY MORNING...AS HIGH PRESSURE BUILDS INTO THE AREA.
HIGH PRESSURE WILL BE IN CONTROL OF THE WEATHER OVER THE REGION
THROUGH THURSDAY...ALLOWING FOR DRY WEATHER. THIS WILL ALLOW RIVERS
AND STREAMS TO HOLD STEADY OR RECEDE...WITH FLOWS EXPECTED TO BE
AROUND SEASONAL LEVELS. A STORM SYSTEM LOOKS TO MOVE ACROSS THE
REGION SOMETIME BETWEEN FRIDAY AND NEXT WEEKEND...WITH RAIN AND SNOW
POSSIBLE.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/BGM
SHORT TERM...FRUGIS
LONG TERM...ELH
AVIATION...IRL
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
358 AM EST MON NOV 18 2013
.DISCUSSION...
CURRENT...LATEST RUC ANALYSIS SHOWS A FRONTAL TROF EXTENDING FROM
THE LWR MS VALLEY UP THE APPALACHIAN RANGE PRESSING E/SE. AHEAD OF
THE FRONT...A POCKET OF MID LVL VORTICITY IS HUGGING THE N GULF
COAST...COUPLED WITH A CORRESPONDING AREA OF LIFTING OMEGA AND UPR
LVL DIVERGENCE. IR SAT PICS SHOWING SOME ENHANCED CLOUD TOPS WITH
THIS FEATURE...THOUGH KTLH-KMOB WSR-88D RADARS ONLY INDICATING
AREAS OF LIGHT TO MODERATE RAIN. WEAK H100-H70 RIDGE AXIS BISECTING
THE FL PENINSULA TOPPED BY AN H85-H50 ANTICYCLONE OVER THE CENTRAL
GOMEX. EVENING RAOB SOUNDINGS WERE ON THE MOIST SIDE WITH PWAT
VALUES BTWN 1.7"-1.8"...THOUGH ONLY KJAX SHOWED ANY DEFINITIVE
CONCENTRATION OF LOW LVL MOISTURE.
TODAY-TONIGHT...
THE FRONTAL TROF WILL COLLAPSE THE WRN FLANK OF THE LOW LVL RIDGE AS
A STRONG STORM SYSTEM OVER THE GREAT LAKES REGION PULLS THE COLD
FRONT INTO THE FL PANHANDLE. DESPITE A STRONG NW PUSH BEHIND THE
FRONT...THE MID LVL ANTICYCLONE WILL SLOW ITS ADVANCEMENT AND KEEP
IT AS THE PRIMARY WX FEATURE TO START THE WEEK. THE LCL AIRMASS WILL
BECOME SATURATED AS THE PREFRONTAL MOISTURE BAND SLIPS ITS WAY INTO
CENTRAL FL. HOWEVER...THERE IS LIMITED AVAILABLE ENERGY UPSTREAM...
MOST OF WHICH IS CONFINED TO THE WRN GOMEX ON THE FAR SIDE OF THE
AFOREMENTIONED ANTICYCLONE.
THE POSITION OF THE MID LVL ANTICYCLONE WILL BLOCK OUT WHAT LITTLE
MOST OF WHAT LITTLE MID/UPPER LVL ENERGY IS AVAILABLE. MEANWHILE...
AS THE GREAT LAKES STORM SYSTEM LIFT INTO ERN CANADA...IT WILL TAKE
MOST OF ITS TORQUE WITH IT...LEAVING THE SRN EXTENSION OF ITS
FRONTAL TROF ON ITS OWN TO PUSH INTO CENTRAL FL. THE FROPA WILL BE
QUITE SLOW...ESPECIALLY WITH WITH ZONAL FLOW ALOFT. NEVERTHELESS...
IT WILL PROVIDE SUFFICIENT LOW LVL CONVERGENCE AND DEEP ENOUGH
MOISTURE TO GENERATE A RESPECTABLE CHANCE FOR PRECIP ACRS THE CWA.
EVEN SO...WITH SUCH WEAK THERMODYNAMIC/DYNAMIC PROFILES...MOST OF
THE PRECIP WITH THIS SYSTEM WILL BE LIGHT WITH MAX QPF VALUES BTWN
0.10"-0.25" OVER MOST OF THE CWA THRU DAYBREAK TUE.
DESPITE CONSIDERABLE CLOUD COVER...THE S/SW FLOW WILL GENERATE WARM
TEMPS ACRS THE CENTRAL PENINSULA WITH MOST AREAS CLIMBING INTO THE
L/M80S...5-9C ABV AVG. WEAK PGRAD WILL PREVAIL...SHOULD SEE AN EAST
COAST SEA BREEZE DEVELOP BY EARLY AFTERNOON FROM THE CAPE ESPECIALLY
IF CLOUD COVER IS SLOW TO PUSH S. CONTINENTAL WIND COMPONENT WILL BE
BRIEF AND LIMITED TO THE OVERNIGHT PD. COUPLED WITH THE BLANKET
EFFECT OF THE PREFRONTAL CLOUD BAND...MIN TEMPS TONIGHT NOT EXPECTED
TO DROP MUCH BLO THE M60S...7-12F ABV AVG.
TUE-TUE NIGHT...
SOUTHERN END OF FRONTAL BOUNDARY WILL BECOME ORIENTED WEST-EAST
AS IT SAGS INTO THE AREA. WHILE THE FLOW ALOFT IS ZONAL AND NO
IMPULSES ARE NOTED...LOW LEVEL MOISTURE CONVERGENCE LOOKS QUITE
IMPRESSIVE FOR THIS TIME OF THE YEAR. THE GFS SHOWS PRECIPITABLE
WATER NEAR 2 INCHES ACROSS THE SOUTH HALF WITH LOW LEVEL NORTHEAST
WINDS 20-25 KNOTS. MOS POPS ARE ABOUT 40 PERCENT IN THE FAR NORTH
TO 70 PERCENT IN THE SOUTH. DID NOT GO THAT HIGH THOUGH...STAYING
ABOUT 20 PERCENT UNDER THOSE VALUES FOR NOW.
LOW LEVEL ONSHORE FLOW WILL STILL BE QUITE STRONG TUE NIGHT SO
HAVE HAD TO BUMP UP POPS FROM THE PREVIOUS FORECAST...WITH 20
PERCENT VALUES IN THE NORTH TO 40 IN THE FAR SOUTHEAST.
WITH SUCH BREEZY LOW LEVEL WINDS...THERE IS A SLIGHT CHANCE FOR
SOME HEAVY RAINFALL MAINLY ALONG THE TREASURE COAST.
SOME MARINE MODIFICATION AND CLOUD COVER WILL PRODUCE LOWER HIGH
TEMPS...ESPECIALLY ACROSS THE NORTH HALF.
WED-THU...
STRONG HIGH PRESSURE ALONG THE EASTERN SEABOARD WILL MAINTAIN A
BREEZY EASTERLY WIND FLOW. FRONTAL BAND MOISTURE IS FORECAST TO
LINGER ACROSS THE AREA...PARTICULARLY THE SOUTH. HENCE HAVE HAD TO
BUMP UP PREVIOUS POPS TO 20 PERCENT NORTH AND 50 PERCENT SOUTHEAST
ON WED. RAIN CHANCES LOOK A LITTLE LESS THU AS RIDGING ALOFT IS
INDICATED AND HAVE 20 PERCENT FOR MOST OF THE AREA AND 30 PERCENT
ALONG THE TREASURE COAST.
FRI-MON...
DEEP LAYER RIDGING OVER THE WESTERN ATLANTIC IS FORECAST TO SHOVE
HIGHEST MOISTURE TO OUR SOUTH FRI-SAT AND HAVE CONTINUED OUR DRY
FORECAST FOR THE MOST PART. THERE COULD BE A FEW ATLANTIC SHOWERS
PUSHING ASHORE MAINLY IN THE FAR SOUTH FRI.
THE NEXT FRONT IS FORECAST TO DROP THROUGH SUNDAY OR SUNDAY NIGHT.
MOISTURE LOOKS LIMITED SO ONLY HAVE SLIGHT CHANCE POPS WITH IT. IT
IS STILL A LONG WAY OUT BUT THE GFS AND ECMWF SUGGEST THAT THERE
WILL BE A LITTLE MORE COOLING WITH THIS FRONT...BACK TO SLIGHTLY
BELOW NORMAL...WHICH WOULD BE A CHANGE FROM THE MOSTLY ABOVE
NORMAL TEMPS WE HAVE HAD THIS MONTH.
&&
.AVIATION...THRU 18/15Z...PREVAILING CIGS AOA FL120 N OF KMLB-KGIF
WITH AREAS CIGS BTWN FL040-060 ALONG AND N OF KISM-KTIX...PATCHY
MVFR/BRIEF LCL IFR VSBYS IN BR/FG. BTWN 18/15Z-18/17Z...SFC
WNDSHFT FM SW TO E BLO 10KTS BTWN KTIX-KSUA...PREVAILING CIGS AOA
FL120 ALL SITES WITH AREAS CIGS BTWN FL040-060 N OF KMLB-KGIF. AFT
18/17Z...VCSH ALL SITES WITH PREVAILING CIGS BTWN FL040-60.
&&
.MARINE...
TODAY-TONIGHT...WEAK HIGH PRES RIDGE BISECTING THE FL PENINSULA WILL
GENERATE A LIGHT TO GENTLE S/SW BREEZE THRU THE DAY. A WEAKENING
COLD FRONT WILL PUSH INTO CENTRAL FLORIDA OVERNIGHT...FORCING WINDS
N OF SEBASTIAN INLET TO VEER TO THE N/NW AND FRESHEN TO 15-20KTS
THROUGH THE PREDAWN HRS. SEAS 2-3FT NEARSHORE AND 3-4FT OFFSHORE
THRU MIDNIGHT...BUILDING TO 3-4FT NEARSHORE AND 4-5FT OFFSHORE BY
DAYBREAK.
TUE-FRI...STRONG HIGH PRESSURE ALONG THE EASTERN SEABOARD WILL
PRODUCE A TIGHT GRADIENT INTO LATE WEEK. ENOUGH CONFIDENCE EXISTS
TO INITIATE ADVISORIES ON TUE FOR THE WATERS FROM SEBASTIAN INLET
NORTHWARD. EXPECT THE ADVISORY TO COVER ALL OF THE WATERS BY TUE
NIGHT OR WED.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 82 65 75 64 / 50 60 20 20
MCO 86 65 77 64 / 50 60 30 20
MLB 83 67 80 70 / 40 50 40 30
VRB 84 67 82 72 / 40 40 50 40
LEE 84 64 76 61 / 50 60 20 20
SFB 84 65 76 63 / 50 60 30 20
ORL 85 65 77 64 / 50 60 30 20
FPR 84 67 81 72 / 30 40 50 40
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...SMALL CRAFT ADVISORY FROM 10 AM TUESDAY TO 4 AM EST THURSDAY FOR
COASTAL WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD COUNTY
LINE OUT 20 NM-WATERS FROM FLAGLER BEACH TO VOLUSIA BREVARD
COUNTY LINE 20 TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY FROM 4 PM TUESDAY TO 4 AM EST THURSDAY FOR
COASTAL WATERS FROM VOLUSIA BREVARD COUNTY LINE TO
SEBASTIAN INLET OUT 20 NM-WATERS FROM VOLUSIA BREVARD
COUNTY LINE TO SEBASTIAN INLET 20 TO 60 NM OFFSHORE.
&&
$$
SHORT TERM...BRAGAW
LONG TERM....LASCODY
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
1225 PM EST MON NOV 18 2013
.UPDATE...
/ISSUED AT 948 AM EST MON NOV 18 2013/
FRONT CONTINUING TO MOVE RAPIDLY THROUGH THE CWA. IT HAS NOW CLEARED
MCN AND CSG. SCATTERED SHOWERS THAT HAD OCCURRED ALONG THE FRONT
HAVE DISSIPATED. THERE COULD BE A FEW SHOWERS DEVELOP AHEAD OF THE
FRONT BEFORE IT PUSHES OUT OF THE CWA AROUND NOON AND HAVE LEFT LOW
CHANCE POPS FOR THE EXTREME SOUTHEAST CORNER OF THE CWA UNTIL NOON.
HAVE TAKEN POPS OUT OF THE FORECAST FOR THIS AFTERNOON AND EVENING
AS DRIER AND MORE STABLE AIR SPREADS ACROSS THE CWA. FORECAST TEMPS
LOOK ON TRACK AS WE ARE GETTING A GOOD REBOUND ACROSS NORTH GA.
LATEST PROGS SHOW THE CAA MOVING INTO THE STATE TONIGHT.
&&
.SHORT TERM /TODAY THROUGH TONIGHT/...
/ISSUED 413 AM EST MON NOV 18 2013/
AT THE SURFACE...COLD FRONT MOVING THROUGH WILL BRING SHOWERS ALONG
AND AHEAD OF IT THROUGH EARLY TO MIDDAY MONDAY ENDING FROM NORTH TO
SOUTH AS IT MOVES THROUGH. ALOFT...MAIN UPPER LEVEL ENERGY
RESPONSIBLE FOR THE SEVERE OUTBREAK ON SUNDAY ACROSS THE OHIO VALLEY
REGION IS MOVING THROUGH THE GREAT LAKES AND AWAY FROM OUR REGION.
END RESULT IS GENERALLY ZONAL FLOW IN THE MID AND UPPER LEVELS
ACROSS THE SOUTHEAST U.S. WITH SURFACE HIGH PRESSURE BUILDING IN
BEHIND THE FRONT. HAVE KEPT HIGH POPS IN WITH THE FRONT AS IT
PROGRESSES SOUTH AND EAST BUT TAPER THEM OFF QUICKLY BEHIND. HAVE
ALSO REMOVED ALL MENTION OF THUNDER AS INSTABILITY IS ALL BUT GONE.
MAIN CONCERN WITH THE FRONT IS GUSTY WINDS WITH THE SHOWERS MIXING
SOME OF THE STRONG WINDS OFF THE SURFACE DOWN. VAD WINDS SHOWING 20
TO 30 KTS IN THE LOWEST FEW THOUSAND FEET. HAVE ALREADY SEEN SOME
GUSTS TO NEAR 40 MPH ACROSS NORTH GA WITH SOME OF THE SHOWERS.
WINDS WILL PICK UP THROUGH THE DAY AS THE CLEARING LINE PROGRESSES
THROUGH THE REGION AND THE SURFACE RIDGE BUILDS IN.
OTHERWISE...THE REMAINDER OF THE SHORT TERM FORECAST LOOKS GOOD.
USED A MODEL BLEND FOR MOST ELEMENTS...WITH THE RUC AND HRRR IN THE
IMMEDIATE SHORT TERM.
30
.LONG TERM /TUESDAY THROUGH SUNDAY/...
/ISSUED 413 AM EST MON NOV 18 2013/
QUIET WEATHER IS ON TAP FOR MOST OF THE LONG TERM PERIOD. A COLD
FRONT IS EXPECTED TO IMPACT THE CWFA LATE IN THE WEEK/EARLY PART OF
THE WEEKEND...BRINGING THE NEXT BEST CHANCES FOR PRECIPITATION.
HIGH PRESSURE WILL CONTINUE ACROSS THE SE US THROUGH WEDNESDAY
BEFORE BEGINNING TO SHIFT EASTWARD ON THURSDAY. A COLD FRONT WILL
MOVE INTO THE MISSISSIPPI RIVER VALLEY ON FRIDAY. THE FRONT IS
EXPECTED TO MOVE THROUGH THE CWFA ON SATURDAY...WITH HIGH PRESSURE
RETURNING FOR THE REMAINDER OF THE WEEKEND INTO THE EARLY PART OF
NEXT WEEK.
PRECIP CHANCES WILL BEGIN TO INCREASE LATER ON THURSDAY AS MOISTURE
BEGINS TO INCREASE AHEAD OF THE APPROACHING FRONTAL BOUNDARY. THE
FRONT IS STILL PROGGED TO COME THROUGH DURING THE DAY ON
SATURDAY...WITH THE MODELS INDICATING SOME MARGINAL INSTABILITY AT
THIS TIME. WILL KEEP THE MENTION OF THUNDER.
STRONG HIGH PRESSURE WILL BUILD BEHIND THE FRONTAL BOUNDARY...AND
BREEZY/WIND CONDITIONS ARE POSSIBLE SATURDAY NIGHT INTO SUNDAY. IN
ADDITION...A COLDER AND DRIER AIRMASS WILL SETTLE OVER THE SOUTHERN
STATES.
NLISTEMAA
&&
.AVIATION...
18Z UPDATE...
VFR CONDITIONS EXPECTED THROUGH THE FORECAST. SKIES WILL BE CLEAR
THROUGH EARLY TONIGHT...THEN CIRRUS WILL BEGIN SPREADING OVER THE
FORECAST AREA LATE TONIGHT AND CONTINUE INTO TUESDAY. WINDS WILL BE
NORTHWEST WITH GUSTS OF 15 TO 20KTS...DIMINISHING SOMEWHAT TONIGHT
AND THEN SWITCHING TO THE NORTHEAST/EAST ON TUESDAY.
//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
17
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 46 59 36 / 20 0 5 0
ATLANTA 71 47 59 38 / 30 0 0 5
BLAIRSVILLE 66 38 56 32 / 20 0 0 0
CARTERSVILLE 69 42 58 36 / 30 0 0 0
COLUMBUS 77 53 64 41 / 70 0 5 5
GAINESVILLE 68 45 57 36 / 20 5 0 0
MACON 78 50 62 38 / 60 5 5 5
ROME 68 43 58 36 / 20 0 0 5
PEACHTREE CITY 73 45 60 37 / 30 0 5 5
VIDALIA 80 55 63 41 / 50 10 5 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...30
LONG TERM....NLISTEMAA
AVIATION...30
AREA FORECAST DISCUSSION...UPDATED
NWS PEACHTREE CITY GA
948 AM EST MON NOV 18 2013
.UPDATE...
FRONT CONTINUING TO MOVE RAPIDLY THROUGH THE CWA. IT HAS NOW CLEARED
MCN AND CSG. SCATTERED SHOWERS THAT HAD OCCURRED ALONG THE FRONT
HAVE DISSIPATED. THERE COULD BE A FEW SHOWERS DEVELOP AHEAD OF THE
FRONT BEFORE IT PUSHES OUT OF THE CWA AROUND NOON AND HAVE LEFT LOW
CHANCE POPS FOR THE EXTREME SOUTHEAST CORNER OF THE CWA UNTIL NOON.
HAVE TAKEN POPS OUT OF THE FORECAST FOR THIS AFTERNOON AND EVENING
AS DRIER AND MORE STABLE AIR SPREADS ACROSS THE CWA. FORECAST TEMPS
LOOK ON TRACK AS WE ARE GETTING A GOOD REBOUND ACROSS NORTH GA.
LATEST PROGS SHOW THE CAA MOVING INTO THE STATE TONIGHT.
&&
.SHORT TERM /TODAY THROUGH TONIGHT/...
/ISSUED 413 AM EST MON NOV 18 2013/
AT THE SURFACE...COLD FRONT MOVING THROUGH WILL BRING SHOWERS ALONG
AND AHEAD OF IT THROUGH EARLY TO MIDDAY MONDAY ENDING FROM NORTH TO
SOUTH AS IT MOVES THROUGH. ALOFT...MAIN UPPER LEVEL ENERGY
RESPONSIBLE FOR THE SEVERE OUTBREAK ON SUNDAY ACROSS THE OHIO VALLEY
REGION IS MOVING THROUGH THE GREAT LAKES AND AWAY FROM OUR REGION.
END RESULT IS GENERALLY ZONAL FLOW IN THE MID AND UPPER LEVELS
ACROSS THE SOUTHEAST U.S. WITH SURFACE HIGH PRESSURE BUILDING IN
BEHIND THE FRONT. HAVE KEPT HIGH POPS IN WITH THE FRONT AS IT
PROGRESSES SOUTH AND EAST BUT TAPER THEM OFF QUICKLY BEHIND. HAVE
ALSO REMOVED ALL MENTION OF THUNDER AS INSTABILITY IS ALL BUT GONE.
MAIN CONCERN WITH THE FRONT IS GUSTY WINDS WITH THE SHOWERS MIXING
SOME OF THE STRONG WINDS OFF THE SURFACE DOWN. VAD WINDS SHOWING 20
TO 30 KTS IN THE LOWEST FEW THOUSAND FEET. HAVE ALREADY SEEN SOME
GUSTS TO NEAR 40 MPH ACROSS NORTH GA WITH SOME OF THE SHOWERS.
WINDS WILL PICK UP THROUGH THE DAY AS THE CLEARING LINE PROGRESSES
THROUGH THE REGION AND THE SURFACE RIDGE BUILDS IN.
OTHERWISE...THE REMAINDER OF THE SHORT TERM FORECAST LOOKS GOOD.
USED A MODEL BLEND FOR MOST ELEMENTS...WITH THE RUC AND HRRR IN THE
IMMEDIATE SHORT TERM.
30
.LONG TERM /TUESDAY THROUGH SUNDAY/...
/ISSUED 413 AM EST MON NOV 18 2013/
QUIET WEATHER IS ON TAP FOR MOST OF THE LONG TERM PERIOD. A COLD
FRONT IS EXPECTED TO IMPACT THE CWFA LATE IN THE WEEK/EARLY PART OF
THE WEEKEND...BRINGING THE NEXT BEST CHANCES FOR PRECIPITATION.
HIGH PRESSURE WILL CONTINUE ACROSS THE SE US THROUGH WEDNESDAY
BEFORE BEGINNING TO SHIFT EASTWARD ON THURSDAY. A COLD FRONT WILL
MOVE INTO THE MISSISSIPPI RIVER VALLEY ON FRIDAY. THE FRONT IS
EXPECTED TO MOVE THROUGH THE CWFA ON SATURDAY...WITH HIGH PRESSURE
RETURNING FOR THE REMAINDER OF THE WEEKEND INTO THE EARLY PART OF
NEXT WEEK.
PRECIP CHANCES WILL BEGIN TO INCREASE LATER ON THURSDAY AS MOISTURE
BEGINS TO INCREASE AHEAD OF THE APPROACHING FRONTAL BOUNDARY. THE
FRONT IS STILL PROGGED TO COME THROUGH DURING THE DAY ON
SATURDAY...WITH THE MODELS INDICATING SOME MARGINAL INSTABILITY AT
THIS TIME. WILL KEEP THE MENTION OF THUNDER.
STRONG HIGH PRESSURE WILL BUILD BEHIND THE FRONTAL BOUNDARY...AND
BREEZY/WIND CONDITIONS ARE POSSIBLE SATURDAY NIGHT INTO SUNDAY. IN
ADDITION...A COLDER AND DRIER AIRMASS WILL SETTLE OVER THE SOUTHERN
STATES.
NLISTEMAA
&&
.AVIATION...
12Z UPDATE...
COLD FRONT EXTENDING FROM CSG TO MCN AT 12Z WILL CONTINUE MOVING
SOUTH THROUGH THE AREA. WIND SHIFT TO THE NW ASSOCIATED WITH THE
FRONT AS WELL AS AN END TO ANY IFR CIGS. WILL MAINTAIN SOME MVFR
CIGS FOR A COUPLE HOURS BEHIND THE FRONT BEFORE GOING VFR AREAWIDE
BY 18Z. WITH THE COLD AIR FILTERING IN...IS POSSIBLE FOR SOME CU
EARLY THIS AFTERNOON...BUT CONFIDENCE IS LOW. GUSTY NORTHWEST
WINDS IN STORE THIS AFTERNOON AT ALL TAF SITES BEFORE RELAXING A
BIT AFTER SUNSET.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF CIG HEIGHT CHANGES.
HIGH CONFIDENCE ALL OTHER ELEMENTS.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 46 59 36 / 20 0 5 0
ATLANTA 71 47 59 38 / 30 0 0 5
BLAIRSVILLE 66 38 56 32 / 20 0 0 0
CARTERSVILLE 69 42 58 36 / 30 0 0 0
COLUMBUS 77 53 64 41 / 70 0 5 5
GAINESVILLE 68 45 57 36 / 20 5 0 0
MACON 78 50 62 38 / 60 5 5 5
ROME 68 43 58 36 / 20 0 0 5
PEACHTREE CITY 73 45 60 37 / 30 0 5 5
VIDALIA 80 55 63 41 / 50 10 5 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...30
LONG TERM....NLISTEMAA
AVIATION...30
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
935 AM EST MON NOV 18 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH LATE THIS AFTERNOON AND EARLY THIS
EVENING...FOLLOWED BY HIGH PRESSURE BUILDING FROM THE NORTH
THROUGH THE END OF THE WORK WEEK. ANOTHER COLD FRONT WILL MOVE
ACROSS THE REGION SATURDAY AND SATURDAY NIGHT...WITH HIGH PRESSURE
RETURNING INTO EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SATELLITE AND SURFACE OBSERVATIONS SHOW THE COLD FRONT MOVING
SLOWLY EAST THROUGH THE MIDLANDS...CSRA AND CENTRAL GEORGIA. THE
FRONT IS EXPECTED TO SLOW DOWN OVER THE NEXT FEW HOURS ONLY TO
ACCELERATE OFFSHORE THIS EVENING AS SHORTWAVE ENERGY PASSES TO THE
NORTH. IN THE MEANTIME...THE ENTIRE FORECAST AREA LOOKS TO REMAIN
WELL EMBEDDED WITHIN THE PRE-FRONTAL WARM SECTOR THROUGH THE
AFTERNOON WITH WARM...MOIST CONDITIONS CONTINUING. DESPITE
EXTENSIVE CLOUD COVER...ONGOING WARM AIR ADVECTION WILL PUSH
HIGHS INTO THE UPPER 70S TO AROUND 80 FOR MOST LOCATIONS. SHOWER
ACTIVITY AHEAD OF THE FRONT HAS BEEN STEADILY DIMINISHING WITH
TIME AS MID-LEVEL DRY AIR OVERSPREADS THE AREA. THE BEST CHANCES
FOR MEASURABLE RAINFALL WILL REMAIN ACROSS THE FAR SOUTHERN ZONES
CLOSER TO THE ALTAMAHA RIVER. WILL CONTINUE TO HIGHLIGHT 40-50
PERCENT POPS IN THESE AREAS WITH 20-30 PERCENT POPS ELSEWHERE.
THERE WILL BE A SMALL WINDOW FOR SOME TSTM ACTIVITY THIS AFTERNOON
AS RAP INSTABILITY PROGS SHOW SBCAPE REACHING AS HIGH AS 1500 J/KG
WITH AS MUCH AS 30 KT OF 0-6 KM BULK SHEAR. THIS MAY SUPPORT A STRONG
TSTM OR TWO...BUT THE OVERALL SEVERE RISK LOOKS PRETTY LOW AT THIS
POINT.
COASTAL WEBCAMS STILL SHOW AREAS OF DENSE SEA FOG IMPACTING THE
BEACHES OF CHARLESTON COUNTY WHERE VISIBILITIES HAVE BEEN AS LOW
AS 1/4 MILE AT TIMES. THE FOG IS NOT WIDESPREAD ENOUGH TO JUSTIFY
A DENSE FOG ADVISORY...BUT THE RISK FOR REDUCED VISIBILITIES WILL
REMAIN ALONG THE BEACHES FOR MUCH OF THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...THE COLD FRONT SHOULD CLEAR THE COAST BY
MIDNIGHT...LATEST ACROSS SOUTHEAST GEORGIA...WITH STRONG HIGH
PRESSURE MOVING IN FROM THE NORTHWEST AFTER MIDNIGHT. THIS WILL
LEAD TO RAPID DRYING AND INCREASING NORTH WINDS...ESPECIALLY NEAR
THE COAST.
THE SYNOPTIC PATTERN IN THE MID-WEEK PERIOD WILL BE DOMINATED BY A
NEARLY ZONAL FLOW ALOFT...WITH WEAK RIDGING STARTING TO BUILD ON
THURSDAY. MEANWHILE AT THE SURFACE...HIGH PRESSURE WILL BUILD INTO
THE REGION FROM THE NORTH AS THE CENTER DRIFTS FROM THE OHIO VALLEY
ON TUESDAY...TO OVER NEW ENGLAND ON WEDNESDAY...THEN TO A POSITION
NEAR OR JUST OFF THE NEW ENGLAND COAST ON THURSDAY.
STRONG SUBSIDENCE AND A LACK OF DEEP MOISTURE SHOULD KEEP CONDITIONS
RAIN-FREE ACROSS THE AREA...WITH THE EXCEPTION OF PORTIONS OF THE
IMMEDIATE SOUTHEAST GEORGIA COAST WHERE A NORTHEAST FLOW COULD ALLOW
ISOLATED SHOWERS TO ADVECT ONSHORE WEDNESDAY AND WEDNESDAY NIGHT.
EXPECT A GOOD AMOUNT OF SUNSHINE ON TUESDAY DESPITE SOME JET
CIRRUS...BUT INCREASING LOW LEVEL MOISTURE WEDNESDAY AND THURSDAY
COULD RESULT IN PARTLY TO MOSTLY CLOUDY SKIES DUE TO THE PRESENCE OF
CUMULUS AND/OR STRATOCUMULUS.
HIGH TEMPERATURES WILL BE BELOW NORMAL TUESDAY AND WEDNESDAY WITH
HIGHS IN THE LOWER TO MID 60S...BUT MODERATE CLOSER TO NORMAL WITH
HIGHS IN THE UPPER 60S TO NEAR 70 BY THURSDAY. LOW TEMPERATURES ON
WEDNESDAY MORNING SHOULD BE IN THE UPPER 30S TO LOWER 40S INLAND
FROM THE IMMEDIATE COAST...BUT COULD GET COOLER INLAND IF WINDS FULLY
DECOUPLE. INCREASED CLOUD COVER THURSDAY MORNING WILL RESULT IN
LOWS IN THE LOWER TO MID 40S AWAY FROM THE IMMEDIATE COAST.
LAKE WINDS...WINDS SHOULD GUSTS TO 25 KT LATE TONIGHT AND
CONTINUE INTO TUESDAY AFTERNOON ON LAKE MOULTRIE AS MUCH COLDER
AND DRIER AIR MOVES IN OVER THE RELATIVELY WARM LAKE CREATING
IDEAL CONDITIONS FOR MIXING STRONG LOW-LEVEL WINDS DOWN TO THE
SURFACE. THUS...A LAKE WIND ADVISORY HAS BEEN ISSUED.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
MEDIUM RANGE IS IN FAIRLY GOOD AGREEMENT THROUGH THE LONG TERM
PERIOD. IN THE MID AND UPPER LEVELS OF THE ATMOSPHERE...A RIDGE WILL
BUILD ACROSS THE SOUTHEAST STATES FROM THE GULF OF MEXICO...BEFORE A
DEEP TROUGH SWINGS ACROSS THE CENTRAL U.S. ON SATURDAY THEN THE
EASTERN U.S. ON SUNDAY WITH A ZONAL FLOW RETURNING FOR MONDAY. AT
THE SURFACE...HIGH PRESSURE WILL MOVE OFF THE EASTERN SEABOARD ON
FRIDAY...ALLOWING A RETURN FLOW TO DEVELOP IN ADVANCE OF AN
APPROACHING COLD FRONT. THE FRONT SHOULD MOVE THROUGH LATE
SATURDAY AND SATURDAY NIGHT...FOLLOWED BY STRONG HIGH PRESSURE
BUILDING FROM THE NORTHWEST.
THERE IS A SLIGHT CHANCE OR CHANCE OF SHOWERS IN THE FORECAST
SATURDAY...SATURDAY NIGHT AND EARLY SUNDAY IN ASSOCIATION WITH THE
COLD FRONT...OTHERWISE RAIN-FREE CONDITIONS ARE EXPECTED. STRONG
WARM AIR ADVECTION AND COMPRESSIONAL HEATING AHEAD OF THE FRONT WILL
RESULT IN ABOVE NORMAL TEMPERATURES FRIDAY AND SATURDAY...WITH A
SIGNIFICANT COOL-DOWN EXPECTED BEHIND THE FRONT SUNDAY AND MONDAY.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
ABUNDANT LOW LEVEL MOISTURE HAS PRODUCED WIDESPREAD STRATUS ACROSS
THE AREA THIS MORNING...WITH IFR OR LOW-END MVFR CEILINGS EXPECTED TO
REMAIN IN PLACE AT THE TERMINALS THROUGH ABOUT 16Z...BEFORE
LIFTING MORE SOLIDLY INTO THE MVFR CATEGORY THROUGH ABOUT 22Z.
VFR CONDITIONS ARE THEN EXPECTED IN WAKE OF A PASSING COLD FRONT
AS WINDS VEER NORTHWEST AND EVENTUALLY NORTH AND CEILINGS
DISSIPATE. THERE COULD BE SOME SCATTERED SHOWERS AHEAD OF THE
FRONT FROM ABOUT MIDDAY THROUGH MID-LATE AFTERNOON AND HAVE
INDICATED MAINLY VCSH AT BOTH TERMINALS...WITH A FEW HOURS OF SHRA
FROM 19-22Z AT KSAV WHERE PROBABILITIES OF RAINFALL ARE SLIGHTLY
GREATER. THERE IS A LOW PROBABILITY FOR SOME THUNDERSTORMS AS
WELL...ESPECIALLY AT KSAV...BUT DUE TO UNCERTAINTY IN
TIMING/COVERAGE HAVE LEFT MENTION OUT OF THE FORECAST.
WINDS LATE TONIGHT INCREASE UPWARDS OF 30-35 KT WITHIN 2K FT OF
THE SURFACE...SO LOW LEVEL WIND SHEAR COULD BECOME A CONCERN. WILL
NEED TO MONITOR TRENDS FOR POSSIBLE INCLUSION IN LATER TAF
ISSUANCES.
EXTENDED AVIATION OUTLOOK...BREEZY CONDITIONS WILL BE POSSIBLE AT
BOTH TERMINALS THROUGH MIDWEEK...OTHERWISE VFR CONDITIONS WILL
PREVAIL.
&&
.MARINE...
TODAY...COASTAL WEBCAM AND PILOT BOAT REPORTS INDICATE VISIBILITIES
HAVE IMPROVED FOR ALL WATERS EXCEPT THE CHARLESTON COUNTY WATERS.
HAVE THEREFORE CANCELLED THE MARINE DENSE FOG ADVISORY FOR ALL BUT
AMZ350 AND THE CHARLESTON HARBOR WHERE DENSE FOG LINGERS NEAR THE
HARBOR ENTRANCE. THE SEA FOG IS EXPECTED TO GRADUALLY SHRINK BELOW
ADVISORY THRESHOLDS OFF THE CHARLESTON COUNTY COAST THIS
AFTERNOON...SO THE ADVISORY WILL REMAIN IN FORCE THROUGH NOON.
HOWEVER...SEA FOG IS RESILIENT AND HARD TO PREDICT. FURTHER
ADJUSTMENTS WILL BE NEEDED LATER TODAY. OTHERWISE...WINDS WILL
REMAIN FAIRLY BENIGN OVER THE WATERS TODAY WITH SEAS 2-4 FT.
TONIGHT...WEST WINDS WILL SHIFT TO THE NORTH AND INCREASE RAPIDLY
AS STRONG HIGH PRESSURE BUILDS INTO THE AREA BEHIND THE COLD
FRONT. EXPECT SOLID ADVISORY CONDITIONS TO DEVELOP FROM NORTH TO
SOUTH WITH GUSTS POSSIBLY NEARING GALE FORCE LATE BEYOND 20 NM.
SEAS WILL BUILD QUICKLY AS WELL...UP TO 6 FT WITHIN 20 NM AND UP
TO 8 FT IN THE 20-60 NM GA ZONE.
TUESDAY THROUGH SATURDAY...STRONG HIGH PRESSURE BUILDING FROM THE
NORTH WILL RESULT IN A TIGHT SURFACE PRESSURE GRADIENT THROUGH THE
MIDDLE OF THE WEEK...WITH A STRONG NORTHEAST FLOW EXPECTED AS COLD
AIR ADVECTION OCCURS OVER THE WATERS. WILL NEED TO MONITOR THIS
SITUATION AS MARGINAL GALE CONDITIONS ARE POSSIBLE OVER THE OUTER
GEORGIA WATERS INTO TUESDAY. FOR NOW...SMALL CRAFT ADVISORIES ARE IN
EFFECT FOR HAZARDOUS MARINE CONDITIONS THROUGH TUESDAY FOR THE
CHARLESTON HARBOR...THROUGH WEDNESDAY NIGHT FOR ALL NEAR SHORE
WATERS...AND INTO THURSDAY NIGHT FOR THE OUTER GEORGIA WATERS WHERE
SEAS WILL REMAIN ELEVATED DESPITE DIMINISHING WINDS ON
THURSDAY/THURSDAY NIGHT. WINDS WILL BEGIN TO VEER ON FRIDAY WITH A
SOUTHERLY RETURN FLOW DEVELOPING BY SATURDAY AHEAD OF AN APPROACHING
COLD FRONT. WINDS AND SEAS SHOULD REMAIN BELOW SMALL CRAFT ADVISORY
LEVELS FRIDAY AND SATURDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY FROM 1 AM TO 4 PM EST TUESDAY FOR SCZ045.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TUESDAY TO 6 AM EST THURSDAY
FOR AMZ352-354.
DENSE FOG ADVISORY UNTIL NOON EST TODAY FOR AMZ330-350.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 AM EST
THURSDAY FOR AMZ350.
SMALL CRAFT ADVISORY FROM 1 AM TUESDAY TO MIDNIGHT EST
THURSDAY NIGHT FOR AMZ374.
SMALL CRAFT ADVISORY FROM 1 AM TO 4 PM EST TUESDAY FOR AMZ330.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
639 AM EST MON NOV 18 2013
.PREV DISCUSSION... /ISSUED 413 AM EST MON NOV 18 2013/
SHORT TERM /TODAY THROUGH TONIGHT/...
AT THE SURFACE...COLD FRONT MOVING THROUGH WILL BRING SHOWERS ALONG
AND AHEAD OF IT THROUGH EARLY TO MIDDAY MONDAY ENDING FROM NORTH TO
SOUTH AS IT MOVES THROUGH. ALOFT...MAIN UPPER LEVEL ENERGY
RESPONSIBLE FOR THE SEVERE OUTBREAK ON SUNDAY ACROSS THE OHIO VALLEY
REGION IS MOVING THROUGH THE GREAT LAKES AND AWAY FROM OUR REGION.
END RESULT IS GENERALLY ZONAL FLOW IN THE MID AND UPPER LEVELS
ACROSS THE SOUTHEAST U.S. WITH SURFACE HIGH PRESSURE BUILDING IN
BEHIND THE FRONT. HAVE KEPT HIGH POPS IN WITH THE FRONT AS IT
PROGRESSES SOUTH AND EAST BUT TAPER THEM OFF QUICKLY BEHIND. HAVE
ALSO REMOVED ALL MENTION OF THUNDER AS INSTABILITY IS ALL BUT GONE.
MAIN CONCERN WITH THE FRONT IS GUSTY WINDS WITH THE SHOWERS MIXING
SOME OF THE STRONG WINDS OFF THE SURFACE DOWN. VAD WINDS SHOWING 20
TO 30 KTS IN THE LOWEST FEW THOUSAND FEET. HAVE ALREADY SEEN SOME
GUSTS TO NEAR 40 MPH ACROSS NORTH GA WITH SOME OF THE SHOWERS.
WINDS WILL PICK UP THROUGH THE DAY AS THE CLEARING LINE PROGRESSES
THROUGH THE REGION AND THE SURFACE RIDGE BUILDS IN.
OTHERWISE...THE REMAINDER OF THE SHORT TERM FORECAST LOOKS GOOD.
USED A MODEL BLEND FOR MOST ELEMENTS...WITH THE RUC AND HRRR IN THE
IMMEDIATE SHORT TERM.
30
LONG TERM /TUESDAY THROUGH SUNDAY/...
QUIET WEATHER IS ON TAP FOR MOST OF THE LONG TERM PERIOD. A COLD
FRONT IS EXPECTED TO IMPACT THE CWFA LATE IN THE WEEK/EARLY PART OF
THE WEEKEND...BRINGING THE NEXT BEST CHANCES FOR PRECIPITATION.
HIGH PRESSURE WILL CONTINUE ACROSS THE SE US THROUGH WEDNESDAY
BEFORE BEGINNING TO SHIFT EASTWARD ON THURSDAY. A COLD FRONT WILL
MOVE INTO THE MISSISSIPPI RIVER VALLEY ON FRIDAY. THE FRONT IS
EXPECTED TO MOVE THROUGH THE CWFA ON SATURDAY...WITH HIGH PRESSURE
RETURNING FOR THE REMAINDER OF THE WEEKEND INTO THE EARLY PART OF
NEXT WEEK.
PRECIP CHANCES WILL BEGIN TO INCREASE LATER ON THURSDAY AS MOISTURE
BEGINS TO INCREASE AHEAD OF THE APPROACHING FRONTAL BOUNDARY. THE
FRONT IS STILL PROGGED TO COME THROUGH DURING THE DAY ON
SATURDAY...WITH THE MODELS INDICATING SOME MARGINAL INSTABILITY AT
THIS TIME. WILL KEEP THE MENTION OF THUNDER.
STRONG HIGH PRESSURE WILL BUILD BEHIND THE FRONTAL BOUNDARY...AND
BREEZY/WIND CONDITIONS ARE POSSIBLE SATURDAY NIGHT INTO SUNDAY. IN
ADDITION...A COLDER AND DRIER AIRMASS WILL SETTLE OVER THE SOUTHERN
STATES.
NLISTEMAA
&&
.AVIATION...
12Z UPDATE...
COLD FRONT EXTENDING FROM CSG TO MCN AT 12Z WILL CONTINUE MOVING
SOUTH THROUGH THE AREA. WIND SHIFT TO THE NW ASSOCIATED WITH THE
FRONT AS WELL AS AN END TO ANY IFR CIGS. WILL MAINTAIN SOME MVFR
CIGS FOR A COUPLE HOURS BEHIND THE FRONT BEFORE GOING VFR AREAWIDE
BY 18Z. WITH THE COLD AIR FILTERING IN...IS POSSIBLE FOR SOME CU
EARLY THIS AFTERNOON...BUT CONFIDENCE IS LOW. GUSTY NORTHWEST
WINDS IN STORE THIS AFTERNOON AT ALL TAF SITES BEFORE RELAXING A
BIT AFTER SUNSET.
//ATL CONFIDENCE...12Z UPDATE...
MEDIUM CONFIDENCE ON TIMING OF CIG HEIGHT CHANGES.
HIGH CONFIDENCE ALL OTHER ELEMENTS.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 46 59 36 / 20 0 5 0
ATLANTA 71 47 59 38 / 30 0 0 5
BLAIRSVILLE 66 38 56 32 / 20 0 0 0
CARTERSVILLE 69 42 58 36 / 30 0 0 0
COLUMBUS 77 53 64 41 / 70 0 5 5
GAINESVILLE 68 45 57 36 / 20 5 0 0
MACON 78 50 62 38 / 60 5 5 5
ROME 68 43 58 36 / 20 0 0 5
PEACHTREE CITY 73 45 60 37 / 30 0 5 5
VIDALIA 80 55 63 41 / 50 10 5 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...30
LONG TERM....NLISTEMAA
AVIATION...30
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
413 AM EST MON NOV 18 2013
.SHORT TERM /TODAY THROUGH TONIGHT/...
AT THE SURFACE...COLD FRONT MOVING THROUGH WILL BRING SHOWERS ALONG
AND AHEAD OF IT THROUGH EARLY TO MIDDAY MONDAY ENDING FROM NORTH TO
SOUTH AS IT MOVES THROUGH. ALOFT...MAIN UPPER LEVEL ENERGY
RESPONSIBLE FOR THE SEVERE OUTBREAK ON SUNDAY ACROSS THE OHIO VALLEY
REGION IS MOVING THROUGH THE GREAT LAKES AND AWAY FROM OUR REGION.
END RESULT IS GENERALLY ZONAL FLOW IN THE MID AND UPPER LEVELS
ACROSS THE SOUTHEAST U.S. WITH SURFACE HIGH PRESSURE BUILDING IN
BEHIND THE FRONT. HAVE KEPT HIGH POPS IN WITH THE FRONT AS IT
PROGRESSES SOUTH AND EAST BUT TAPER THEM OFF QUICKLY BEHIND. HAVE
ALSO REMOVED ALL MENTION OF THUNDER AS INSTABILITY IS ALL BUT GONE.
MAIN CONCERN WITH THE FRONT IS GUSTY WINDS WITH THE SHOWERS MIXING
SOME OF THE STRONG WINDS OFF THE SURFACE DOWN. VAD WINDS SHOWING 20
TO 30 KTS IN THE LOWEST FEW THOUSAND FEET. HAVE ALREADY SEEN SOME
GUSTS TO NEAR 40 MPH ACROSS NORTH GA WITH SOME OF THE SHOWERS.
WINDS WILL PICK UP THROUGH THE DAY AS THE CLEARING LINE PROGRESSES
THROUGH THE REGION AND THE SURFACE RIDGE BUILDS IN.
OTHERWISE...THE REMAINDER OF THE SHORT TERM FORECAST LOOKS GOOD.
USED A MODEL BLEND FOR MOST ELEMENTS...WITH THE RUC AND HRRR IN THE
IMMEDIATE SHORT TERM.
30
.LONG TERM /TUESDAY THROUGH SUNDAY/...
QUIET WEATHER IS ON TAP FOR MOST OF THE LONG TERM PERIOD. A COLD
FRONT IS EXPECTED TO IMPACT THE CWFA LATE IN THE WEEK/EARLY PART OF
THE WEEKEND...BRINGING THE NEXT BEST CHANCES FOR PRECIPITATION.
HIGH PRESSURE WILL CONTINUE ACROSS THE SE US THROUGH WEDNESDAY
BEFORE BEGINNING TO SHIFT EASTWARD ON THURSDAY. A COLD FRONT WILL
MOVE INTO THE MISSISSIPPI RIVER VALLEY ON FRIDAY. THE FRONT IS
EXPECTED TO MOVE THROUGH THE CWFA ON SATURDAY...WITH HIGH PRESSURE
RETURNING FOR THE REMAINDER OF THE WEEKEND INTO THE EARLY PART OF
NEXT WEEK.
PRECIP CHANCES WILL BEGIN TO INCREASE LATER ON THURSDAY AS MOISTURE
BEGINS TO INCREASE AHEAD OF THE APPROACHING FRONTAL BOUNDARY. THE
FRONT IS STILL PROGGED TO COME THROUGH DURING THE DAY ON
SATURDAY...WITH THE MODELS INDICATING SOME MARGINAL INSTABILITY AT
THIS TIME. WILL KEEP THE MENTION OF THUNDER.
STRONG HIGH PRESSURE WILL BUILD BEHIND THE FRONTAL BOUNDARY...AND
BREEZY/WIND CONDITIONS ARE POSSIBLE SATURDAY NIGHT INTO SUNDAY. IN
ADDITION...A COLDER AND DRIER AIRMASS WILL SETTLE OVER THE SOUTHERN
STATES.
NLISTEMAA
&&
AVIATION...
06Z UPDATE...
COLD FRONT ENTERING NORTHWEST GA WITH A LINE OF SHOWERS NOTED ON
RADAR IN ASSOCIATION WITH THE FRONT. BASED ON CURRENT SPEED AM
PROJECTING AN ARRIVAL TIME AT ATL BTW 09Z AND 10Z. HAVE REFLECTED
THIS IN THE 06Z TAF ISSUANCE BY MOVING THINGS UP AN HOUR. EXPECT
IFR AND EVEN SOME LIFR CONDITIONS OFF AND ON UNTIL THE FRONT
PASSES AT ALL TAF SITES. PREVIOUS FORECAST LOOKS GOOD BEYOND
FRONTAL PASSAGE WITH STRONG NORTHWEST WINDS DURING THE DAY TODAY
AND RELAXING AFTER SUNSET AND OTHERWISE VFR CONDITIONS.
//ATL CONFIDENCE...06Z UPDATE...
MEDIUM CONFIDENCE ON LIFR CONDITIONS WITH FRONT...HIGH CONFIDENCE
ON ALL OTHER ELEMENTS.
30
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 72 46 59 36 / 20 0 5 0
ATLANTA 71 47 59 38 / 30 0 0 5
BLAIRSVILLE 66 38 56 32 / 20 0 0 0
CARTERSVILLE 69 42 58 36 / 30 0 0 0
COLUMBUS 77 53 64 41 / 70 0 5 5
GAINESVILLE 68 45 57 36 / 20 5 0 0
MACON 78 50 62 38 / 60 5 5 5
ROME 68 43 58 36 / 20 0 0 5
PEACHTREE CITY 73 45 60 37 / 30 0 5 5
VIDALIA 80 55 63 41 / 50 10 5 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...30
LONG TERM....NLISTEMAA
AVIATION...30
AREA FORECAST DISCUSSION
NWS BOISE ID
237 PM MST MON NOV 18 2013
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...A VIGOROUS AND FAST-
MOVING SERIES OF SYSTEMS IS MOVING EAST TOWARD THE PAC NW. THE
INITIAL WAVE IS SET TO MOVE INTO SE OREGON THIS EVENING AND INTO
SW IDAHO OVERNIGHT. LATEST GUIDANCE FROM THE 18Z NAM IS SLOWING
THE SYSTEM DOWN SIGNIFICANTLY...BUT WILL GO WITH THE OVERWHELMING
AGREEMENT OF THE GFS AND EC...ALONG WITH THE 12Z NAM AND THE
LATEST HRRR RUNS...ON THE PRECIP AREA GETTING THROUGH THE TREASURE
VALLEY BY 12Z. CLOUD COVER WILL BE EXTENSIVE TONIGHT...KEEPING
LOW TEMPS WELL ABOVE NORMAL. THE SECOND MAJOR WAVE IN THE SERIES
WILL MOVE THROUGH TUE NIGHT INTO WED...BRINGING ANOTHER ROUND OF
WIDESPREAD PRECIP. SNOW LEVELS FOR BOTH EVENTS WILL BE TOO HIGH TO
BRING SNOW TO THE VALLEYS...WITH HEIGHTS RANGING FROM 5000 FEET IN
THE NORTH TO 7500 FEET IN THE SOUTH TONIGHT...AND FROM 5500 FEET
IN THE NORTH TO 6500 FEET IN THE SOUTH FOR TUE NIGHT INTO WED
MORNING WHEN THE MAJORITY OF THE PRECIP ASSOCIATED WITH THE SECOND
SYSTEM WILL FALL. HEIGHTS WILL COME DOWN SWIFTLY THROUGH THE DAY
WED...CHANGING THE RAIN TO SNOW IN THE NORTH...BUT BY THAT TIME
MOST OF THE PRECIP WILL HAVE ENDED. TEMPS THROUGH THE SHORT TERM
WILL HAVE MINIMAL DIURNAL RANGE OWING TO CLOUD COVER. CHANGES FROM
THE PREVIOUS FORECAST WERE MINOR.
.LONG TERM...WEDNESDAY NIGHT THROUGH MONDAY...MOSTLY DRY
CONDITIONS WEDNESDAY NIGHT AND THURSDAY WITH LINGERING SHOWERS
ALONG THE NEVADA BORDER AS A WEATHER SYSTEM EXITS TO THE EAST AND
A RIDGE OF HIGH PRESSURE BUILDS OFF THE WEST COAST. DRY CONDITIONS
WILL CONTINUE OVER THE FORECAST AREA FRIDAY THROUGH MONDAY. AS THE
RIDGE OF HIGH PRESSURE STRENGTHENS OVER THE FORECAST AREA
TEMPERATURE INVERSIONS WILL DEVELOP FRIDAY MORNING AND WILL
PERSIST THROUGH THE WEEKEND AND INTO EARLY NEXT WEEK. WITH
RESIDUAL MOISTURE FROM THE PRECIPITATION FROM TUESDAY AND
WEDNESDAY COMBINED WITH THE INVERSIONS WILL SEE AREAS OF VALLEY
FOG AND LOW STRATUS. TEMPERATURES WILL AVERAGE NEAR NORMAL BUT
VALLEY LOCATIONS UNDER THE INVERSION WILL LIKELY SEE TEMPERATURES
A FEW DEGREES BELOW NORMAL.
&&
.AVIATION...WIDESPREAD PRECIPITATION WILL MOVE INTO THE REGION
THIS EVENING AND WILL LINGER OVER THE AREA THROUGH TUESDAY. ONCE
PRECIPITATION BEGINS MOUNTAINS WILL BECOME OBSCURED ALONG WITH
AREAS OF MVFR AND LOCAL IFR CONDITIONS. SNOW LEVEL WILL BE AT OR
ABOVE 5K FEET MSL. LATEST TIMING OF PRECIPITATION STARTING AT TAF
SITES WILL BE AROUND 04Z FOR KBNO...KBKE AND KMYL...AROUND 10Z FOR
KBOI AND AROUND 15Z FOR KTWF AND KJER. SURFACE WINDS TONIGHT WILL
BE SOUTHEAST TO SOUTHWEST GENERALLY 10 KNOTS OR LESS. WINDS ALOFT
WILL BE SOUTHWESTERLY AROUND 15 KNOTS UP THROUGH 10K FEET MSL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...NONE.
OR...NONE.
&&
$$
WEATHER.GOV/BOISE
SHORT TERM...SP
LONG TERM....JA/WH
AVIATION.....JA
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1252 AM EST MON NOV 18 2013
.SYNOPSIS...
HIGH PRESSURE EAST OF NEW ENGLAND WILL SLIDE TO THE EAST. DEEPENING
LOW PRESSURE OVER THE WESTERN GREAT LAKES WILL MOVE NORTHEAST INTO
CANADA...PUSHING A COLD FRONT ACROSS THE LOCAL AREA EARLY MONDAY.
HIGH PRESSURE THEN RETURNS FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
SURFACE ANALYSIS SHOWS A ~980MB LOW JUST NORTH OF LAKE SUPERIOR IN
SOUTHERN ONTARIO, WITH A STRONG COLD FRONT SOUTH THROUGH EASTERN
ILLINOIS TO NORTHEAST TEXAS. ALOFT, MID EVENING WATER VAPOR SAT
IMAGERY SHOWING NEGATIVELY TILTED SHORT WAVE TROUGH PUSHING E-NE
FROM THE MID MISSOURI VALLEY TOWARDS THE UPPER MIDWEST.
RADAR MOSAIC INDICATES A BATCH OF LIGHT RAIN ACROSS SOUTHWEST
VIRGINIA.
A WEAK AREA OF SUBTLE UPPER VORT/WEAK LIFT HAS ALLOWED SOME
SCATTERED SHOWERS/SPRINKLES TO CROP UP IN THE WARM SECTOR THIS
EVENING. HAVE REORGANIZED POPS SLIGHTLY AND WILL GO WITH ISO/SCT
SHRA WORDING EARLY THIS EVENING. HRRR HAS HANDLED RADAR TRENDS
REASONABLY WELL THIS EVENING...WITH ITS SOLUTION KEEPING AREAL
COVERAGE OF SHRAS RATHER SPOTTY THROUGH MUCH OF THE NIGHT. THIS
DOES MAKE SENSE GIVEN RATHER ANEMIC FORCING WITH PRE-FRONTAL PCPN.
SHOWERS DO INCREASE IN COVERAGE LATE W/AFOREMENTIONED COLD FRONT
DROPPING INTO THE NW CORNER OF THE CWA AROUND 09Z. A NARROW LINE
OF SHOWERS LOOKS TO ACCOMPANY THE FRONT...MOST LIKELY WITH BEST
FORCING/CONVERGENCE OVER THE NORTHERN HALF OF THE AREA. HAVE
LIKELY POPS OVER THIS AREA WITH THE FRONTAL PASSAGE...WITH HIGH
CHC POPS FARTHER SOUTH. FRONT SWEEPS QUICKLY TO THE EAST, WITH
DRYING ALOFT QUICKLY BRINGING AN END TO PCPN BEHIND THE FRONT. BY
12Z...THE FRONT WILL EXTEND FROM THE EASTERN PART OF THE NORTHERN
NECK THROUGH THE RICHMOND METRO AREA AND INTO NORTH CENTRAL NC.
PRE-FRONTAL S/SW WINDS WL INCREASE OVER THE NEXT FEW HRS, KEEPING
TEMPERATURES ON THE MILD SIDE. DESPITE STRONG SHEAR...KEPT TSTMS
OUT OF THE FCST. CAPE WILL BE VERY LIMITED AND THE SURFACE WILL
REMAIN STABLE. A FEW GUSTS TO AROUND 30 MPH WILL BE PSBL NEAR THE
FRONT AND ASSOCIATED SHOWERS.
TEMPERATURES HAVE LEVELED OFF THIS EVENING...AND EXPECT STEADY
TEMPS TO RISE SLIGHTLY OVERNIGHT AHEAD OF THE FRONT. EARLY
MORNING LOW TEMPERATURES TO RANGE FROM 60 TO 65...WITH UPR 50S
BEHIND THE FRONT OVER LOUISA AND FLUVANNA COUNTIES.
ON MONDAY...THE FRONT MOVES OFF THE COAST AROUND MIDDAY. PCPN ENDS
IN MOST AREAS IN THE MRNG BUT KEPT SLGT CHC POPS ON THE NC COAST
THROUGH 20Z. DOWNSLOPE FLOW SHOULD BRING SUNSHINE BEHIND THE FRONT
ACROSS THE WESTERN CWA...AND ALLOW TEMPERATURES TO BE MILD ON
MONDAY. EXPECT MAXIMA IN THE LOW TO MID 70S ACROSS MOST OF THE AREA
EXCEPT NEAR 70 WEST OF INTERSTATE 95. TEMPERATURES WILL BEGIN TO
FALL DURING THE AFTN OVER WESTERN SECTIONS. WINDS WILL BE BREEZY
FROM THE WEST AND NORTHWEST...ESPECIALLY NEAR THE COAST.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
MONDAY NIGHT THROUGH TUESDAY NIGHT IS STRAIGHTFORWARD WITH DRY
CONDITIONS AND A MOSTLY CLEAR SKY. HIGH PRESSURE WILL BE OVER THE
NORTHEASTERN STATES WITH RIDGING INTO THE MID ATLANTIC. THE CORE OF
THE RIDGE WILL BE OVERHEAD TUESDAY WHICH WILL REDUCE MIXING SOME.
MODELS ARE ALL OVER THE PLACE WITH HIGH TEMPERATURES BUT STAYED
CLOSE TO OUR PREVIOUS FORECAST AND MOS GUIDE. HIGH TEMPERATURES WILL
RANGE FROM 50 TO 55. ON WEDNESDAY...NE TO E FLOW WILL RESULT IN AN
INCREASE IN CLOUDS AND TEMPERATURES A BIT LOWER...ESPECIALLY OVER
THE PIEDMONT. READINGS ARE EXPECTED TO RANGE FROM AROUND 50 IN THE
PIEDMONT TO THE MID 50S IN NE NORTH CAROLINA. KEPT SLGT CHC FOR
SHOWERS FOR THE NC COAST WITH SOME MODEL SUPPORT...ESPECIALLY FROM
THE GFS FOR THIS POSSIBILITY. LOW TEMPERATURES TUESDAY AND
WEDNESDAY MORNINGS WILL GENERALLY RANGE FROM 30 TO 35.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE SHIFTS OFF THE NRN NEW ENGLAND COAST WED NIGHT AND
THU...THEN STARTS TO SLIDE DOWN THE ATLANTIC COAST THU NIGHT AND
FRI. THE PRESSURE GRADIENT WILL REMAIN TIGHT OVER SERN PORTIONS OF
THE REGION WED NIGHT...FOLLOWED BY ADDITIONAL RELAXING OF THE
GRADIENT IN THIS AREA BY THU AFTN. NW-N WINDS WILL REMAIN BREEZY
NEAR COASTAL AREAS WED THROUGH FRI DUE TO THE PERSISTENT ONSHORE
FLOW. AS WINDS BECOME MORE NE-E ON WED...EXPECT LOW CLOUDS TO MOVE
INTO COASTAL AREAS FROM THE OCEAN. THIS COULD RESULT IN LIGHT RAIN
SHOWERS AND OCCASIONAL DRIZZLE WED/THU. AN APPROACHING COLD FRONT
WILL BOOST TEMPS ACROSS THE REGION FRI/FRI NIGHT...FOLLOWED BY
ANOTHER POTENTIAL BLAST OF ARCTIC AIR SAT/SUN.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
FIRST BATCH OF PRE FRONTAL SHOWERS WILL QUICKLY MOVE OFFSHORE
NEXT FEW HOURS. DESPITE A GUSTY SOUTH WIND UP TO 20 KTS...IFR
STRATUS HAS DEVELOPED ACROSS THE PIEDMONT AND WILL LIKELY MOVE
EAST. THUS...EXPECT CHANGEABLE CIGS AND VSBYS NEXT FEW HOURS WITH
SPORATIC SHOWERS.
MAIN COLD FRONT PROGGED BETWEEN 8-12Z. LATEST MODEL DATA SUGGESTS
LINE OF CONVECTION WITH THIS FRONT WEAKENS AS IT CROSSES THE
MOUNTAINS DUE TO LACK OF UPR LEVEL SUPPORT. STILL CAN`T RUKE OUT A
GUSTY SHOWER WITH THE ACTUAL FROPA AT RIC/SBY WHERE BEST SUPPORT
WILL BE. SCT SHOWERS CONTINUE ACROSS SERN TAF SITES WITH GUSTY
S-SW WINDS UP TO 25 KT.
RAPID IMPROVEMENT AFTER FROPA. DECREASING CLOUDINESS THRU 18Z.
WINDS SHIFT INTO W-NW AT 10-20 KTS. SKC EXPECTED AFTER 00Z.
&&
.MARINE...
WEAK HIGH PRESSURE CONTINUES TO BREAKDOWN THIS EVENING AS E-SE WINDS
REMAIN AOB 10 KT WITH SEAS AVERAGING 1-3 FT. THIS ALL CHANGES
OVERNIGHT AS A VERY STRONG COLD FRONT APPROACHES THE
REGION...CAUSING THE SFC PRESSURE GRADIENT TO TIGHTEN AND THE WINDS
TO VEER TO THE S. WINDS SHIFT TO THE SW AND QUICKLY INCREASE INTO
LOW-END SCA THRESHOLDS JUST AHEAD OF AND ALONG THE FRONTAL PASSAGE
DURING THE PRE-DAWN AND EARLY DAYLIGHT HOURS MON MORNING. SPEEDS
OF 20-25 KT BAY/COASTAL WATERS AND 15-20 KT CURRITUCK SOUND SHOULD
BE ANTICIPATED DURING THE AFOREMENTIONED TIMEFRAME. WAVES ON CHES
BAY WILL QUICKLY BUILD TO 3-4 FT WHILE SEAS QUICKLY RESPOND AND JUMP
TO 4-6 FT FOR ALL COASTAL WATERS (UP TO 7 FT NEAR 20 NM FROM FENWICK
ISLAND TO CHINCOTEAGUE). SW WINDS TURN TO THE W-NW BEHIND THE
FRONTAL PASSAGE ON MON AND SPEEDS WILL DIMINISH BELOW SCA THRESHOLDS
DURING THE DAYTIME. THIS WILL BE SHORT-LIVED AS COLDER TEMPERATURES
FROM A MODIFIED ARCTIC AIRMASS MOVE OVER THE WATERS EARLY MON
EVENING THROUGH TUE. THIS PARTICULAR SET-UP WILL RESULT IN A NW-N
SURGE BEGINNING MON NIGHT AND CONTINUING THROUGH TUE NIGHT BEFORE
WINDS BEGIN TO DIMINISH ON WED. EXPECT THE STRONGEST SURGE TO OCCUR
EARLY TUE MORNING WHEN THE WIND DIRECTION TURNS FROM NW TO N. WIND
SPEEDS ARE ANTICIPATED TO INCREASE TO 20-25 KT (SOLID SCA
CONDITIONS) OVER ALL WATERS...WITH GUSTS TO AROUND 30 KT. RESPONDING
WAVES ARE EXPECTED TO REBUILD TO 4-5 FT OVER CHES BAY. SEAS ARE ALSO
EXPECTED TO BUILD FROM 3-4 FT MONDAY EVENING TO 5-6 FT EARLY TUE
MORNING. PREVIOUS FLAGS FOR COASTAL WATERS NORTH OF THE VA/NC BORDER
AND CHES BAY HAVE BEEN EXTENDED THROUGH TUESDAY EVENING...DESPITE
THE LULL IN WINDS MON AFTN. ADDITIONAL FLAGS HAVE BEEN ISSUED FOR
SRN COASTAL WATERS FROM THE VA/NC BORDER TO CURRITUCK
LIGHT...CURRITUCK SOUND FOR TONIGHT THROUGH TUE EVENING. AN
ADDITIONAL SCA FLAG HAS BEEN ISSUED FOR THE LOWER JAMES RIVER FOR
LATE TONIGHT INTO MON MORNING. HEADLINES FOR REST OF ERN VA RIVERS
WILL LIKELY BE NEEDED FOR MON NIGHT INTO TUESDAY BUT WILL HOLD OFF
ON ISSUING THEM ATTM.
HIGH PRESSURE BEGINS TO SHIFT ACROSS THE OH VALLEY ON TUE...THEN
SHIFTS OVER NRN NEW ENGLAND TUE NIGHT THROUGH WED. THE PRESSURE
GRADIENT WILL REMAIN TIGHT OVER THE WATERS DURING THIS TIMEFRAME.
N WINDS WILL REMAIN ELEVATED IN LOW-END SCA WIND SPEEDS EARLY TUE
NIGHT...THEN START TO DIMINISH AFTER MIDNIGHT INTO WED. EXPECT
WINDS AFTER MIDNIGHT TO AOB 15 KT BAY/RIVERS/SOUND...AOB 20 KT
COASTAL WATERS. AS THE NRN NEW ENGLAND HIGH PRESSURE CENTER MOVES
ACROSS NRN NEW ENGLAND TO JUST OFF ITS COAST ON WED NIGHT INTO
THU...WINDS BECOME MORE NE-E/ONSHORE. SPEEDS WILL BEGIN TO SLACKEN
THROUGH WED AND DIMINISH FURTHER WED NIGHT INTO THU. WAVES ON CHES
BAY SHOULD START TO SUBSIDE BY WED AFTN...EXCEPT THE MOUTH OF THE
BAY WHERE ONSHORE WINDS WILL KEEP WAVES HIGHER THROUGH WED NIGHT.
SEAS SHOULD ALSO BE SLOW TO SUBSIDE BELOW 5 FT UNTIL SOMETIME THU
NIGHT/FRI. HIGH PRESSURE LINGERS OFF THE NRN NEW ENGLAND COAST
THROUGH FRI AND ONSHORE FLOW WILL PERSIST.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR ANZ630>634-650-
652-654-656-658.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR ANZ638.
&&
$$
SYNOPSIS...LSA
NEAR TERM...MAM/LSA
SHORT TERM...LSA
LONG TERM...BMD
AVIATION...MPR
MARINE...BMD
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1245 AM EST MON NOV 18 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT INTO
EARLY MONDAY MORNING. HIGH PRESSURE BEHIND THE COLD FRONT WILL
BUILD OVERHEAD LATE MONDAY THROUGH WEDNESDAY. THE HIGH WILL MOVE
OFF THE COAST THURSDAY AND A COLD FRONT MAY IMPACT THE AREA FRIDAY
AND SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
UPDATE...SEVERE THUNDERSTORM WATCH 572 IS IN EFFECT FOR COUNTIES
ALONG AND WEST OF THE BLUE RIDGE AND PARTS OF THE PIEDMONT REGION.
00Z RADAR AND OBSERVATIONS INDICATE THE COLD FRONT HAS REACHED
WESTERN OHIO...AND CONTINUES TO PUSH RAPIDLY EASTWARD. SOME
AREAS OF LIGHT RAIN/SHOWERS HAVE MOVED INTO THE MOUNTAINS AND
PIEDMONT. THESE WILL IMPACT THE FORECAST AREA OVER THE NEXT
COUPLE OF HOURS. AFTER THE FIRST BATCH OF RAIN...A RESPITE IS
LIKELY FOR A WHILE THIS EVENING AS A DRY SLOT NOTED ON WATER VAPOR
IMAGERY MOVES INTO THE AREA.
BASED ON SHORT-TERM MODEL OUTPUT...THE COLD FRONT AND ITS
ASSOCIATED LINE OF SHOWERS IS EXPECTED TO REACH THE POTOMAC
HIGHLANDS AROUND 11PM - MIDNIGHT...THEN STEADILY CROSS THE CWA
OVERNIGHT...REACHING CHESAPEAKE BAY AROUND 5AM. THERE HAS BEEN
SOME RUN-TO-RUN INCONSISTENCY IN TERMS OF HOW WELL SHOWER ACTIVITY
WILL REMAIN ORGANIZED AS IT CROSSES THE CWA...ESPECIALLY EAST OF
THE BLUE RIDGE. HRRR HAD PREVIOUSLY HELD THE LINE OF HEAVY
SHOWERS TOGETHER...BUT ITS 22Z RUN JUST IN DETERIORATES THE LINE
SOUTH OF THE POTOMAC RIVER AS IT MOVES EWD. WHEREVER THE LINE
HOLDS TOGETHER...IT WILL HAVE THE POTENTIAL TO TAP INTO A VERY
STRONG LOW LEVEL JET STREAM...WHICH SHOULD REACH AROUND 55-65KTS
AT 850MB AS IT CROSSES THE AREA. WITH IT...GUSTY WINDS ARE
EXPECTED...WITH AN ISOLATED DAMAGING WIND THREAT. ISOLATED THUNDER
REMAINS POSSIBLE AS WELL.
A WIND ADVISORY IS IN EFFECT ACROSS MUCH OF THE POTOMAC HIGHLANDS
AND CENTRAL AND SOUTHERN SHENANDOAH VALLEYS FROM 9PM UNTIL 6 AM
MONDAY. THIS ADVISORY IS PRIMARILY FOR ELEVATIONS ABOVE 2500 FEET
ALONG THE ALLEGHENY FRONT AND BLUE RIDGE. WINDS LOOK LIKE THEY
WILL INCREASE QUICKLY THIS EVENING AND GUST BETWEEN 45 AND 55 MPH
AT THE RIDGE TOPS LATER THIS EVENING AND OVERNIGHT.
WENT WITH NAM MODEL FOR LOW TEMPERATURES TONIGHT...THE WARMER MODEL.
WE HAVE WARM AIR ADVECTION ON A PERSISTENT SOUTHERLY WIND PLUS
CLOUD COVER AHEAD OF THE COLD FRONT.
THE COLD FRONT WILL MOVE OFF TO OUR EAST MONDAY MORNING AND LOW
PRESSURE WILL TRACK ACROSS EASTERN CANADA MONDAY WHILE HIGH
PRESSURE BUILDS OVER THE CENTRAL CONUS. A WESTERLY FLOW BEHIND THE
FRONT WILL DRY THINGS OUT QUICKLY FOR MONDAY...ALLOWING FOR PLENTY
OF SUNSHINE. MONDAY WILL BE MILD DUE TO SUNSHINE ALONG WITH A
DOWNSLOPING FLOW...DESPITE COLD ADVECTION BEHIND THE FRONT. MAX
TEMPS WILL RANGE FROM THE UPPER 50S AND LOWER 60S IN THE
SHENANDOAH VALLEY TO THE UPPER 60S AND LOWER 70S NEAR WASHINGTON
AND BALTIMORE AS WELL AS SOUTHERN MARYLAND. CHILLIER CONDITIONS
ARE EXPECTED IN THE MOUNTAINS WITH TEMPS IN THE 40S. BREEZY
CONDITIONS ARE EXPECTED MONDAY DUE TO A DEEP MIXING LAYER.
WESTERLY WINDS WILL GUST FREQUENTLY AROUND 25 TO 30 MPH WITH GUSTS
AROUND 40 MPH IN THE MOUNTAINS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BUILD OVERHEAD MONDAY NIGHT THROUGH WEDNESDAY.
DRY AND SEASONABLY CHILLY CONDITIONS ARE EXPECTED DURING THIS
TIME.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL SLOWLY DRIFT OFF THE MID-ATLANTIC COAST WEDNESDAY
NIGHT INTO THURSDAY AS UPPER-LEVEL TROUGHING APPROACHES FROM THE
WEST. SURFACE REFLECTION IN THE FORM OF A COLD FRONT WILL APPROACH
THE AREA LATE THURSDAY INTO FRIDAY. SEASONABLE TEMPERATURES ARE
EXPECTED AHEAD OF THE FRONT THROUGH LATE IN THE WEEK. 17/12Z GFS
OPERATIONAL IN BETTER AGREEMENT WITH ITS 06Z ENSEMBLE MEAN AND
17/00Z ECMWF OPERATIONAL/ENSEMBLE MEAN WITH OVERALL PATTERN AND
TIMING OF THE FRONT...ALTHOUGH THE ECMWF TRIES TO DEVELOP A WAVE ON
THE FRONT AS IT CROSSES THE AREA. THE ECMWF IS ALSO A BIT COLDER
FRIDAY NIGHT. FOR NOW...FOLLOWED WPC GUIDANCE WHICH IS A 70/30 BLEND
OF THE 00Z ECMWF ENSEMBLE MEAN/06Z GFS ENSEMBLE MEAN.
THIS RESULTS IN A CHANCE OF PRECIPITATION BEGINNING AND ENDING FROM
WEST TO EAST EARLY FRIDAY MORNING THROUGH SATURDAY. ALTHOUGH BOTH
THE GFS AND TO A GREATER EXTENT THE ECMWF HINT AT COLDER AIR MOVING
IN BEFORE PRECIPITATION ENDS...KEPT ANY MENTION OF SNOW SHOWERS
MIXED WITH RAIN WELL NORTH AND WEST OF THE I-95 CORRIDOR GIVEN
CLIMATOLOGY AND INHERENT UNCERTAINTY/MODEL SPREAD AT THIS TIME RANGE.
A BLAST OF ARCTIC AIR FOLLOWS THE COLD FRONT LEADING TO BELOW NORMAL
TEMPERATURES AREA-WIDE NEXT WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
COLD FRONT WILL MOVE ACROSS THE TERMINALS IN THE NEXT FEW HOURS. A
THIN LINE OF SHOWERS WITH HEAVY RAINFALL AND GUSTY WINDS WILL
ACCOMPANY THE FRONT. AHEAD OF THE FRONT...GENERALLY MVFR
CIGS...WITH IFR LIKELY AS THE HEAVIER RAIN MOVES THROUGH.
AFTER THE FRONT MOVES THROUGH...VFR CONDITIONS WILL RETURN BY
SUNRISE...WITH WINDS SHIFTING TO THE WEST. GUSTS TO AROUND 20KT
WILL DEVELOP DURING THE MORNING AND SHOULD PERSIST THROUGH THE
AFTERNOON.
VFR CONDITIONS ARE EXPECTED MONDAY NIGHT THROUGH WEDNESDAY.
NORTHWEST WINDS WILL GUST AROUND 15 TO 20 KNOTS TUESDAY. WINDS
TUESDAY NIGHT AND WEDNESDAY WILL BE LIGHT. HIGH PRESSURE WILL
REMAIN OVER THE TERMINALS LATE IN THE WEEK.
&&
.MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT TONIGHT FOR SOUTHERLY WINDS
AHEAD OF A COLD FRONT. THERE IS POTENTIAL FOR SPECIAL MARINE
WARNINGS OVERNIGHT AS SHOWERS WITH GUSTY WINDS MOVE THROUGH THE WATERS.
GUSTY WESTERLY WINDS ARE EXPECTED BEHIND A COLD FRONT MONDAY. A
SMALL CRAFT ADVISORY IS IN EFFECT FOR THE WATERS. THE SMALL CRAFT
ADVISORY CONTINUES MONDAY NIGHT FOR THE MARYLAND CHESAPEAKE BAY AND
TIDAL POTOMAC RIVER FROM INDIAN HEAD TO SMITH POINT.
A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS
TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE WILL BUILD OVERHEAD
WEDNESDAY. A RELATIVELY BENIGN SURFACE PRESSURE GRADIENT WILL
LIKELY LEAD TO SUB-SCA CONDITIONS ON AREA WATERS WEDNESDAY NIGHT
THROUGH FRIDAY. A COLD FRONT MAY BRING SHOWERS TO THE WATERS
FRIDAY INTO SATURDAY...FOLLOWED BY INCREASINGLY GUSTY NW FLOW.
&&
.TIDES/COASTAL FLOODING...
ANOMALIES WILL CONTINUE TO INCREASE TONIGHT AS THE SOUTHERLY FLOW
INCREASES. HOWEVER...A COLD FRONT IS EXPECTED TO MOVE THROUGH
OVERNIGHT...WITH WINDS SHIFTING TO THE WEST BEFORE MORNING HIGH
TIDE MONDAY. THEREFORE...MINOR COASTAL FLOODING IS NOT EXPECTED
AS OF NOW. WILL CONTINUE TO MONITOR ANOMALIES BECAUSE CERTAINTY IS
LOW DUE TO THE GUSTY SOUTHERLY FLOW.
WEST WINDS WILL CONTINUE BEHIND THE COLD FRONT MONDAY AND
ANOMALIES WILL DECREASE. TIDAL BLOWOUT IS POSSIBLE LATE MONDAY AND
TUESDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR MDZ501.
VA...WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR VAZ025>027-
029-030-036>040-503-504.
WV...WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR WVZ055-
501>503-505-506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ530>534-536-
537-539>541-543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ535-
538-542.
&&
$$
SYNOPSIS...BJL
NEAR TERM...KS/KLW
SHORT TERM...BJL
LONG TERM...DFH
AVIATION...KCS/DFH
MARINE...BJL/KLW/DFH
TIDES/COASTAL FLOODING...KCS
AREA FORECAST DISCUSSION
NWS BALTIMORE MD/WASHINGTON DC
1142 PM EST SUN NOV 17 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL PASS THROUGH THE REGION LATE TONIGHT INTO
EARLY MONDAY MORNING. HIGH PRESSURE BEHIND THE COLD FRONT WILL
BUILD OVERHEAD LATE MONDAY THROUGH WEDNESDAY. THE HIGH WILL MOVE
OFF THE COAST THURSDAY AND A COLD FRONT MAY IMPACT THE AREA FRIDAY
AND SATURDAY.
&&
.NEAR TERM /THROUGH MONDAY/...
UPDATE...SEVERE THUNDERSTORM WATCH 572 IS IN EFFECT FOR COUNTIES
ALONG AND WEST OF THE BLUE RIDGE AND PARTS OF THE PIEDMONT REGION.
00Z RADAR AND OBSERVATIONS INDICATE THE COLD FRONT HAS REACHED
WESTERN OHIO...AND CONTINUES TO PUSH RAPIDLY EASTWARD. SOME
AREAS OF LIGHT RAIN/SHOWERS HAVE MOVED INTO THE MOUNTAINS AND
PIEDMONT. THESE WILL IMPACT THE FORECAST AREA OVER THE NEXT
COUPLE OF HOURS. AFTER THE FIRST BATCH OF RAIN...A RESPITE IS
LIKELY FOR A WHILE THIS EVENING AS A DRY SLOT NOTED ON WATER VAPOR
IMAGERY MOVES INTO THE AREA.
BASED ON SHORT-TERM MODEL OUTPUT...THE COLD FRONT AND ITS
ASSOCIATED LINE OF SHOWERS IS EXPECTED TO REACH THE POTOMAC
HIGHLANDS AROUND 11PM - MIDNIGHT...THEN STEADILY CROSS THE CWA
OVERNIGHT...REACHING CHESAPEAKE BAY AROUND 5AM. THERE HAS BEEN
SOME RUN-TO-RUN INCONSISTENCY IN TERMS OF HOW WELL SHOWER ACTIVITY
WILL REMAIN ORGANIZED AS IT CROSSES THE CWA...ESPECIALLY EAST OF
THE BLUE RIDGE. HRRR HAD PREVIOUSLY HELD THE LINE OF HEAVY
SHOWERS TOGETHER...BUT ITS 22Z RUN JUST IN DETERIORATES THE LINE
SOUTH OF THE POTOMAC RIVER AS IT MOVES EWD. WHEREVER THE LINE
HOLDS TOGETHER...IT WILL HAVE THE POTENTIAL TO TAP INTO A VERY
STRONG LOW LEVEL JET STREAM...WHICH SHOULD REACH AROUND 55-65KTS
AT 850MB AS IT CROSSES THE AREA. WITH IT...GUSTY WINDS ARE
EXPECTED...WITH AN ISOLATED DAMAGING WIND THREAT. ISOLATED THUNDER
REMAINS POSSIBLE AS WELL.
A WIND ADVISORY IS IN EFFECT ACROSS MUCH OF THE POTOMAC HIGHLANDS
AND CENTRAL AND SOUTHERN SHENANDOAH VALLEYS FROM 9PM UNTIL 6 AM
MONDAY. THIS ADVISORY IS PRIMARILY FOR ELEVATIONS ABOVE 2500 FEET
ALONG THE ALLEGHENY FRONT AND BLUE RIDGE. WINDS LOOK LIKE THEY
WILL INCREASE QUICKLY THIS EVENING AND GUST BETWEEN 45 AND 55 MPH
AT THE RIDGE TOPS LATER THIS EVENING AND OVERNIGHT.
WENT WITH NAM MODEL FOR LOW TEMPERATURES TONIGHT...THE WARMER MODEL.
WE HAVE WARM AIR ADVECTION ON A PERSISTENT SOUTHERLY WIND PLUS
CLOUD COVER AHEAD OF THE COLD FRONT.
THE COLD FRONT WILL MOVE OFF TO OUR EAST MONDAY MORNING AND LOW
PRESSURE WILL TRACK ACROSS EASTERN CANADA MONDAY WHILE HIGH
PRESSURE BUILDS OVER THE CENTRAL CONUS. A WESTERLY FLOW BEHIND THE
FRONT WILL DRY THINGS OUT QUICKLY FOR MONDAY...ALLOWING FOR PLENTY
OF SUNSHINE. MONDAY WILL BE MILD DUE TO SUNSHINE ALONG WITH A
DOWNSLOPING FLOW...DESPITE COLD ADVECTION BEHIND THE FRONT. MAX
TEMPS WILL RANGE FROM THE UPPER 50S AND LOWER 60S IN THE
SHENANDOAH VALLEY TO THE UPPER 60S AND LOWER 70S NEAR WASHINGTON
AND BALTIMORE AS WELL AS SOUTHERN MARYLAND. CHILLIER CONDITIONS
ARE EXPECTED IN THE MOUNTAINS WITH TEMPS IN THE 40S. BREEZY
CONDITIONS ARE EXPECTED MONDAY DUE TO A DEEP MIXING LAYER.
WESTERLY WINDS WILL GUST FREQUENTLY AROUND 25 TO 30 MPH WITH GUSTS
AROUND 40 MPH IN THE MOUNTAINS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
HIGH PRESSURE WILL BUILD OVERHEAD MONDAY NIGHT THROUGH WEDNESDAY.
DRY AND SEASONABLY CHILLY CONDITIONS ARE EXPECTED DURING THIS
TIME.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE WILL SLOWLY DRIFT OFF THE MID-ATLANTIC COAST WEDNESDAY
NIGHT INTO THURSDAY AS UPPER-LEVEL TROUGHING APPROACHES FROM THE
WEST. SURFACE REFLECTION IN THE FORM OF A COLD FRONT WILL APPROACH
THE AREA LATE THURSDAY INTO FRIDAY. SEASONABLE TEMPERATURES ARE
EXPECTED AHEAD OF THE FRONT THROUGH LATE IN THE WEEK. 17/12Z GFS
OPERATIONAL IN BETTER AGREEMENT WITH ITS 06Z ENSEMBLE MEAN AND
17/00Z ECMWF OPERATIONAL/ENSEMBLE MEAN WITH OVERALL PATTERN AND
TIMING OF THE FRONT...ALTHOUGH THE ECMWF TRIES TO DEVELOP A WAVE ON
THE FRONT AS IT CROSSES THE AREA. THE ECMWF IS ALSO A BIT COLDER
FRIDAY NIGHT. FOR NOW...FOLLOWED WPC GUIDANCE WHICH IS A 70/30 BLEND
OF THE 00Z ECMWF ENSEMBLE MEAN/06Z GFS ENSEMBLE MEAN.
THIS RESULTS IN A CHANCE OF PRECIPITATION BEGINNING AND ENDING FROM
WEST TO EAST EARLY FRIDAY MORNING THROUGH SATURDAY. ALTHOUGH BOTH
THE GFS AND TO A GREATER EXTENT THE ECMWF HINT AT COLDER AIR MOVING
IN BEFORE PRECIPITATION ENDS...KEPT ANY MENTION OF SNOW SHOWERS
MIXED WITH RAIN WELL NORTH AND WEST OF THE I-95 CORRIDOR GIVEN
CLIMATOLOGY AND INHERENT UNCERTAINTY/MODEL SPREAD AT THIS TIME RANGE.
A BLAST OF ARCTIC AIR FOLLOWS THE COLD FRONT LEADING TO BELOW NORMAL
TEMPERATURES AREA-WIDE NEXT WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
A COLD FRONT WILL MOVE THROUGH THE REGION OVERNIGHT INTO THE EARLY
MORNING HOURS MONDAY. A FEW PERIODS OF SHOWERS ARE EXPECTED...AND
MOST TERMINALS WILL SEE BRIEF HEAVY RAINFALL WITH POTENTIAL FOR
ISOLATED THUNDERSTORMS. AMENDMENTS LIKELY FOR TEMPO GROUPS FOR
THIS HEAVY RAINFALL ACTIVITY AND ASSOCIATED REDUCED CIGS/VSBYS AS
THE ACTIVITY APPROACHES AND TIMING BECOMES MORE CERTAIN. WINDS
WILL INCREASE AS THE EVENING PROGRESSES...WITH GUSTS AROUND 25KTS
AT DC METRO TERMINALS. HIGHER GUSTS POSSIBLE WITH ANY HEAVY
SHOWER/TSTM ACTIVITY. WINDS WILL SHIFT TO THE WEST AFTER THE FRONT
MOVES THROUGH LATE TONIGHT OR EARLY MONDAY.
VFR CONDITIONS ARE EXPECTED MONDAY THROUGH WEDNESDAY. WESTERLY WINDS
WILL GUST AROUND 25 KNOTS MONDAY BEFORE DIMINISHING TOWARD SUNSET.
NORTHWEST WINDS WILL GUST AROUND 15 TO 20 KNOTS TUESDAY. WINDS
TUESDAY NIGHT AND WEDNESDAY WILL BE LIGHT. HIGH PRESSURE WILL
REMAIN OVER THE TERMINALS LATE IN THE WEEK.
&&
.MARINE...
A SMALL CRAFT ADVISORY IS IN EFFECT TONIGHT FOR SOUTHERLY WINDS
AHEAD OF A COLD FRONT. THERE IS POTENTIAL FOR SPECIAL MARINE
WARNINGS OVERNIGHT AS SHOWERS WITH GUSTY WINDS MOVE THROUGH THE WATERS.
GUSTY WESTERLY WINDS ARE EXPECTED BEHIND A COLD FRONT MONDAY. A
SMALL CRAFT ADVISORY IS IN EFFECT FOR THE WATERS. THE SMALL CRAFT
ADVISORY CONTINUES MONDAY NIGHT FOR THE MARYLAND CHESAPEAKE BAY AND
TIDAL POTOMAC RIVER FROM INDIAN HEAD TO SMITH POINT.
A SMALL CRAFT ADVISORY MAY BE NEEDED FOR PORTIONS OF THE WATERS
TUESDAY AND TUESDAY NIGHT. HIGH PRESSURE WILL BUILD OVERHEAD
WEDNESDAY. A RELATIVELY BENIGN SURFACE PRESSURE GRADIENT WILL
LIKELY LEAD TO SUB-SCA CONDITIONS ON AREA WATERS WEDNESDAY NIGHT
THROUGH FRIDAY. A COLD FRONT MAY BRING SHOWERS TO THE WATERS
FRIDAY INTO SATURDAY...FOLLOWED BY INCREASINGLY GUSTY NW FLOW.
&&
.TIDES/COASTAL FLOODING...
ANOMALIES WILL CONTINUE TO INCREASE TONIGHT AS THE SOUTHERLY FLOW
INCREASES. HOWEVER...A COLD FRONT IS EXPECTED TO MOVE THROUGH
OVERNIGHT...WITH WINDS SHIFTING TO THE WEST BEFORE MORNING HIGH
TIDE MONDAY. THEREFORE...MINOR COASTAL FLOODING IS NOT EXPECTED
AS OF NOW. WILL CONTINUE TO MONITOR ANOMALIES BECAUSE CERTAINTY IS
LOW DUE TO THE GUSTY SOUTHERLY FLOW.
WEST WINDS WILL CONTINUE BEHIND THE COLD FRONT MONDAY AND
ANOMALIES WILL DECREASE. TIDAL BLOWOUT IS POSSIBLE LATE MONDAY AND
TUESDAY.
&&
.LWX WATCHES/WARNINGS/ADVISORIES...
DC...NONE.
MD...WIND ADVISORY UNTIL 6 AM EST MONDAY FOR MDZ501.
VA...WIND ADVISORY UNTIL 6 AM EST MONDAY FOR VAZ025>027-029-030-
036>040-503-504.
WV...WIND ADVISORY UNTIL 6 AM EST MONDAY FOR WVZ055-501>503-505-506.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST TUESDAY FOR ANZ530>534-536-
537-539>541-543.
SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ535-538-542.
&&
$$
SYNOPSIS...BJL
NEAR TERM...KS/KLW
SHORT TERM...BJL
LONG TERM...DFH
AVIATION...BJL/KS/DFH
MARINE...BJL/KLW/DFH
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1257 AM EST MON NOV 18 2013
.SYNOPSIS...
A LARGE STORM SYSTEM WILL STRENGTHEN OVER THE GREAT LAKES AND
BLAST A COLD FRONT THROUGH OUR REGION BETWEEN MIDNIGHT AND DAWN
TONIGHT. THE FRONT WILL BE ACCOMPANIED BY A GUSTY LINE OF SHOWERS
AND ISOLATED THUNDERSTORMS. LOCALIZED DAMAGING WINDS WILL BE POSSIBLE.
COLDER AIR WILL MOVE IN BEHIND THE FRONT...WITH GUSTY WINDS
CONTINUING MONDAY. SOME LAKE EFFECT SNOW SHOWERS CAN BE EXPECTED
MONDAY NIGHT INTO TUESDAY MORNING IN CENTRAL NEW YORK.
&&
.NEAR TERM /THROUGH TODAY/...
815 PM UPDATE...
982MB LOW IS CURRENTLY IN VICINITY OF EXTREME EASTERN UP OF
MICHIGAN. CDFNT EXTNDS TWD THE SOUTH ACROSS CNTRL LWR MICHIGAN AND
THRU WRN OHIO WITH WINDS GUSTING ANYWHERE BTWN 35-50KTS.
CONVECTIVE LINE HAS MADE IT INTO NE OH, HWVR CLD-GROUND LIGHTNING
IS ALMOST NON-EXISTENT WITH THE LINE WITH THE MAIN LIGHTNING
STRIKES OVR ONTARIO AND SRN KY. IN-CLOUD LIGHTNING IS NOT MUCH
BETTER AS JUST A FEW STRIKES EXIST OVR ERN OHIO. 00Z KBUF RAOB
SHOWING MINIMAL CAPES AND POOR LAPSE RATES AT THIS TIME AND ONLY
EXPECT THAT TO CONTINUE AS THE LINE HEADS EAST PER KALY SNDG.
LATEST HRRR CONTINUES TO SUGGEST A VRY THIN CONVECTIVE LINE MVG
THRU BTWN 05Z-09Z, PLACING THE LINE ALONG THE I-81 CORRIDOR BY
07Z. ALL INDICATIONS ARE THAT THIS TIMING LOOKS TO BE RIGHT ON
TARGET. THUNDER THREAT LOOKS ISOLD AT BEST BUT STILL EXPECT A VRY
BRIEF WINDOW OF STRONG WINDS ALONG THE FRONT. THUS, WIND ADVISORY
WL CONTINUE AS IS. WL HANDLE ANY DAMAGING WINDS WITH AN SPS OR
SHORT-FUSED HIGH WIND WRNG.
SEE NO REASON TO CHG HRLY T/TD VALUES AS THEY WL SLOWLY RISE
OVRNGT BFR FROPA. NO CHGS NEEDED TO THESE GRIDS ATTM.
PREV DISCO BLO...
115 PM UPDATE... MAIN CONCERN IS FOR STRONG COLD FRONT MOVING
THROUGH LATE TONIGHT WITH GUSTY WINDS...AND A POTENTIAL SQUALL
THAT COULD HAVE LOCALIZED DAMAGING GUSTS.
WELL AHEAD OF THE FRONT...STOUT SOUTHWEST FLOW IS RIDDLED WITH
SHORTWAVES WHICH HAVE ALREADY PRODUCED SOME SHOWERS OVER THE TWIN
TIERS THROUGH CENTRAL NY. SHOWERS ARE PRESSING SOUTHEAST WITH
TIME YET ALSO WITH SATURATED LAYER NOT AS DEEP SO IS BECOMING MORE
SPOTTY IN COVERAGE. ALL OF THIS OF COURSE TAKES A BACK SEAT TO THE
SET UP FOR TONIGHT.
SYNOPTICALLY SPEAKING...STRONG 850MB JET OCCURS AHEAD OF AND ALONG
FRONT OF 60-75 KTS. COMPARED TO THE WAY THE MODELS LOOKED 24 HRS
AGO...THE JET WHILE STILL STRONG IS NOT POSITIONED QUITE AS LOW
IN THE COLUMN. ALSO...MODEL SOUNDINGS ALL SUGGEST NEAR SURFACE AIR
WILL NOT BE CONDUCIVE FOR MIXING DOWN STRONG GUSTS. UNTIL THE
FRONT COMES...HIGHEST GUSTS WILL BE LIMITED MAINLY TO RIDGETOPS IN
CENTRAL NY. IN COORDINATION WITH ADJOINING NWS OFFICES I HAVE
ELECTED TO REPLACE THE HIGH WIND WATCH WITH A WIND ADVISORY /PLUS
A FEW MORE ZONES/...GIVEN EXPECTATION THAT PEAK GUSTS STAYING
BELOW 50 MPH. ANYTHING HIGHER SHOULD BE LIMITED TO THE POTENTIAL
SQUALL IMMEDIATELY ALONG THE FRONT ITSELF...AS HINTED AT BY SPC
SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR OUR WHOLE AREA. THIS
SHORT-FUSE POSSIBILITY WILL BE HANDLED VIA SPS/SVR IF NECESSARY.
CONFIDENCE HAS INCREASED ON TIMING OF FRONT OVERNIGHT...WITH
SQUALL PASSING THROUGH DURING 05Z-10Z TIME FRAME. LOW TOPPED LINE
EXPECTED WITH LIMITED IF ANY LIGHTNING...BUT CONVECTIVE
NONETHELESS AND CAPABLE OF MIXING DOWN STRONG GUSTS. CONDITIONS
MORE FAVORABLE UPSTREAM...BUT STRONGLY FORCED FRONT WILL STILL
CARRY EAST FROM THERE WITH GOOD GUSTS...THE ONLY QUESTION IS HOW
STRONG. 925-850MB JET WILL BE DECREASING JUST AS FRONT CARRIES
THROUGH THE REGION. ALL-IN-ALL AN EERIE WARM EVENING FOLLOWED BY
AN ACTIVE PERIOD MIDNIGHT ONWARD. FORECAST DETAILS HAVE BEEN
UPDATED TODAY THROUGH TONIGHT...INCLUDING SPECIFIC TIMING FOR
CONVECTIVE LINE...AND QUIRKY VERY MILD NON-DIURNAL TEMPERATURES.
POST-FRONTAL ENVIRONMENT MONDAY WILL CONTINUE TO FEATURE GUSTY
WINDS...THIS TIME JUST FROM PRESSURE GRADIENT. ADVISORY LEVEL
GUSTS STILL PROBABLE FOR MUCH OF CENTRAL NY AND PERHAPS HIGHER
ELEVATIONS OF TWIN TIERS/CATSKILLS. FARTHER SOUTHEAST...25 TO 35
MPH GUSTS. WITH WINDS FROM 250-ISH DIRECTION AND 850MB
TEMPERATURES ONLY DIPPING TO ZERO AND FIVE BELOW CELSIUS BY LATE
MONDAY AFTERNOON...AT LEAST FOR DURING THE DAY I AM ONLY EXPECTING
SPOTTY RAIN SHOWERS REACHING INTO CENTRAL SOUTHERN TIER FROM LAKE
ERIE...AND RAIN SHOWERS DEVELOPING NORTH OF THE NY THRUWAY FROM
LAKE ONTARIO.
NON-DIURNAL TEMPERATURES THROUGH THE PERIOD...INCLUDING VERY MILD
CONDITIONS TONIGHT AND THEN STEADY OR FALLING ON MONDAY DUE TO
STRONG COLD AIR ADVECTION.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY NIGHT/...
SOME LAKE EFFECT
PRECIPITATION WILL LIKELY BE OCCURRING SOUTHEAST LAKE ONTARIO
MONDAY NIGHT. 850 MB TEMPERATURES START OUT AROUND -5 C EARLY IN
THE EVENING AND FALL TO -8 TO -10 BY TUESDAY MORNING. PRECIPITATION
EARLY TUESDAY EVENING WILL LIKELY BE A MIX OF RAIN AND SNOW
SHOWERS EAST OF LAKE ONTARIO... TRENDING TOWARD SNOW OVERNIGHT. BOUNDARY
TEMPERATURES WILL BE MARGINAL FOR ACCUMULATIONS... ESPECIALLY AT
LOWER ELEVATIONS. THE FLOW WILL BE FROM AROUND 290 EARLY IN THE
NIGHT SHIFTING TO AROUND 310 BY TUESDAY MORNING. BASED ON THIS
HAVE GONE WITH LIKELY POPS ACROSS OUR NORTHERN COUNTIES MONDAY
EVENING... THEN CHC POPS SPREADING SOUTH TOWARD THE SOUTHERN TIER OF
NY OVERNIGHT. WITH TEMPERATURES MARGINALLY COLD ENOUGH FOR SNOW
AND SHIFTING WINDS AM NOT EXPECTING A MAJOR EVENT... BUT SOME
SMALL ACCUMULATIONS COULD OCCUR ESPECIALLY AT ELEVATIONS ABOVE
1000 FEET ABOVE SEA LEVEL.
SCATTERED LIGHT SNOW SHOWERS MAY CONTINUE INTO TUESDAY MORNING
WITH A 310-320 FLOW FAVORING AREAS DOWNSTREAM OF THE FINGER
LAKES... HOWEVER WITH TEMPERATURES ONLY MARGINALLY COLD ENOUGH FOR
LAKE EFFECT SNOW AND MOISTURE RAPIDLY DECREASING EXPECT ONLY
MINOR IF ANY ACCUMULATIONS ON TUESDAY. HIGH PRESSURE WIL BUILD ACROSS THE
AREA BRINGING DRY SEASONABLY COOL WEATHER TUESDAY NIGHT INTO
WEDNESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
GFS AND ECMWF ARE IN GENERALLY GOOD AGREEMENT ON THE EVOLUTION OF
THE PATTERN LATE NEXT WEEK ALTHOUGH WITH THE USUAL TIMING AND
INTENSITY DIFFERENCES THAT ARE OFTEN SEEN AT THAT TIME RANGE.
THURSDAY SHOULD BE DRY AND MILD WITH HIGH PRESSURE MOVING OFF THE EAST
COAST. CHANCE OF SHOWERS WILL INCREASE FRIDAY AND SATURDAY AS THE
NEXT COLD FRONT APPROACHES FROM THE WEST. BEST CHANCE FOR
PRECIPITATION APPEARS TO BE SATURDAY AS A COLD FRONT MOVES ACROSS
THE AREA. AT THIS POINT THE MOST LIKELY P-TYPE WITH THIS SYSTEM
APPEARS TO BE RAIN BUT SOME MIX MAY OCCUR IF SOME OF THE COOLER
LONG-RANGE SOLUTIONS WERE TO VERIFY. COLD WEATHER WILL RETURN ON
SUNDAY WITH BOTH THE GFS AND ECMWF ADVERTISING THE COLDEST WEATHER
OF THE SEASON BY EARLY NEXT WEEK.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
06Z UPDATE...
SCATTERED RAIN SHOWERS ARE SLOWLY MOVING ACROSS CENTRAL NEW YORK
AND NORTHEAST PENNSYLVANIA THIS MORNING. THESE SHOWERS ARE A MIX
OF VFR AND MVFR CIGS WITH EMBEDDED IFR CIGS. VISBYS MAY FALL TO
IFR AT KBGM FOR A BRIEF PERIOD OF TIME BUT ARE NOT EXPECTED AT
REMAINING TAF SITES. GUSTY WINDS UP TO 35 KNOTS ARE POSSIBLE WITH
THESE SHOWERS. THESE SHOWERS ARE EXPECTED TO CONTINUE FOR THE NEXT
COUPLE OF HOURS AHEAD OF AN APPROACHING COLD FRONT. BEHIND THE
COLD FRONT AN ABRUPT WIND SHIFT WILL OCCUR AND GUSTY WINDS WILL
FOLLOW. WINDS ARE EXPECTED TO BE SUSTAINED AT 20 KNOTS THROUGH THE
AFTERNOON/EVENING ON MONDAY.
COOLER AND DRIER AIR WILL FUNNEL IN THE REGION MONDAY AFTERNOON
BRINGING A CHANCE FOR LAKE EFFECT RAIN SHOWERS TO KRME LATER IN
THE DAY. THESE SHOWERS WILL DEVELOP AROUND 03Z TUESDAY MORNING AND
CONSIST OF MVFR CIGS.
OUTLOOK...
MON AFTN THRU TUE MRNG...MVFR POSSIBLE IN SNOW SHOWERS...MAINLY SYR
AND RME MON NGT AND PERHAPS ALSO KITH-KBGM TUE MRNG.
WED/THU...VFR.
FRI...POSSIBLE RESTRICTIONS FROM -SHRA.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ038.
NY...WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NYZ009-015>018-
022>025-036-037-044>046-055-056.
&&
$$
SYNOPSIS...MDP/PVN
NEAR TERM...MDP/PVN
SHORT TERM...MSE
LONG TERM...MDP/MSE
AVIATION...KAH
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
233 PM EST MON NOV 18 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE OFFSHORE THIS AFTERNOON. COOL HIGH PRESSURE
WILL THEN BUILD OVER THE REGION THROUGH THE REMAINDER OF THE WORK
WEEK. ANOTHER COLD FRONT WILL MOVE THROUGH THE AREA SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1245 PM MONDAY...MINOR UPDATE FOR LATEST TRENDS. PCPN HAS
DRIED UP BUT LATEST HRRR STILL INDICATES LINGERING SCT SHOWER THREAT
S COAST LATE AFTN...THUS WILL CONTINUE 30 POP REST OF AFTN THERE.
RAISED TEMPS A FEW DEGS WITH SOME SRN SECTIONS INTO UPR 70S.
/PREVIOUS DISCUSSION/
AS OF 705 AM MONDAY...HAVE SPED UP PRECIPITATION AS FRONT ALREADY
APPROACHING THE RALEIGH AREA AND BROKEN LINE OF SHOWERS MOVING
INTO OUR WESTERN CWA. HAVE SCALED BACK POPS TO 30 PCT AS COVERAGE
WILL BE LIMITED AND THINK THE BULK OF THE RAIN WILL BE THROUGH
THE AREA BY MID TO LATE MORNING. TEMPERATURES OFF TO A WARM
START THIS MORNING WITH SEVERAL STATIONS AROUND 70 AND EXPECT
READINGS INTO THE MID 70S AT MANY SITES AHEAD OF THE FRONT. BY
MID- AFTERNOON...EXPECTING GUSTY N/NNE WINDS WITH TEMPS LEVELING
OFF THEN FALLING LATE DURING THE DAYLIGHT HOURS.
&&
.SHORT TERM /TONIGHT THROUGH TUESDAY/...
AS OF 355 AM MONDAY...SKIES SHOULD BECOME CLEAR BY SHORTLY AFTER
DARK WITH NORTHERLY BREEZES BRINGING IN COOLER AND DRIER AIR. FOR
LOW TEMPERATURES TONIGHT...MOST AREAS AWAY FROM THE IMMEDIATE
COAST WILL BE IN THE LOW TO MID 40S WITH TEMPERATURES RIGHT AROUND
50 OVER THE OUTER BANKS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
AS OF 230 PM MON...NO SIGNIFICANT CHANGES NEEDED TO FORECAST AT
THIS TIME. SFC HIGH PRESSURE WILL BUILD OVER THE NE US TUE NIGHT
THROUGH LATE WEEK...EXTENDING SOUTHWARD INTO THE SE STATES...WITH
UPPER RIDGING OVER THE SE. GRADUAL TEMP WARMUP EXPECTED THROUGH
THE WEEK WITH BUILDING HEIGHTS. GOOD RADIATIONAL COOLING
CONDITIONS EXPECTED TUE NIGHT WITH CLEAR SKIES AND LIGHT
WINDS...WITH LOWS IN THE LOWER 30S TO LOW/MID 40S FOR THE OUTER
BANKS. BY THU EXPECT TEMPS NEAR NORMAL IN THE LOW/MID 60S. A COLD
FRONT WILL MOVE THROUGH EASTERN NC SATURDAY WITH INCREASING
MOISTURE AND LIFT...WILL CONTINUE CHANCE POPS SAT THROUGH SAT
NIGHT...SLOWLY TAPERING OFF FROM W TO E EARLY SUN MORNING. STRONG
HIGH PRESSURE WILL BUILD IN BEHIND THE FRONT SUN AND MON. MUCH
COOLER TEMPS EXPECTED BEHIND THE FRONT. LOW LEVEL THICKNESS
VALUES SUPPORT HIGHS IN THE UPPER 40S/LOWER 50S WITH OVERNIGHT
LOWS IN THE LOW/UPPER 30S.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TUESDAY/...
AS OF 1230 PM MONDAY...HIGH CONFIDENCE OF VFR CONDITIONS WILL
DOMINATE THE TAF PERIOD. ONCE THE COLD FRONT CROSSES THE
AREA...DRIER AIR WILL AID TO DISSIPATE THE REMAINING CLOUD COVERAGE
IN THE AREA. HIGH PRESSURE WILL BUILD OVERNIGHT...RESULTING WITH A
TIGHTEN PRESSURE GRADIENT AND INHIBITING ANY FOG/LOW STRATUS
DEVELOPMENT. WINDS WILL INCREASE TO 10 GUSTING UP TO 15 KT TOMORROW
MORNING WITH MOSTLY CLEAR SKIES.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM MON...PREDOMINATE VFR CONDITIONS EXPECTED THROUGH THE
PERIOD. A COLD FRONT WILL MOVE THROUGH THE AREA SATURDAY...WITH
PERIODS OF SUB-VFR CONDITIONS POSSIBLE.
&&
.MARINE...
.SHORT TERM /THROUGH TONIGHT/...
AS OF 1245 PM MONDAY...NO CHANGES WITH UPDATE.
/PREVIOUS DISCUSSION/
AS OF 705 AM MONDAY...NO MAJOR CHANGES TO CURRENT MARINE FORECAST
AS SOUTHWEST WINDS OF 15 TO 20 KNOTS SHOULD GRADUALLY BECOME NW BY
EARLY AFTERNOON. EVEN THOUGH WIND AND WAVE MODELS INDICATE THAT
WINDS/SEAS WILL DIMINISH BELOW SMALL CRAFT ADVISORY FOR A FEW
HOURS LATE THIS AFTERNOON AND EVENING...WINDS AND SEAS ABRUPTLY
INCREASE WITH STRONG CAA BEHIND COLD FRONT TONIGHT AND HAVE OPTED
TO KEEP SMALL CRAFT ADV FOR THE COASTAL WATERS TODAY...TONIGHT AND
INTO MID WEEK GIVEN THE GUSTY N/NE WINDS AND ROUGH SEAS. THE
FRONTAL PASSAGE SHOULD OCCUR FOR THE COASTAL WATERS AROUND 18Z OR
SO WITH WINDS VEERING FROM S/SW EARLY THIS MORNING TO WNW/NW BY
EARLY AFTERNOON.
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM MON...SCA CONDITIONS TO START OFF THE PERIOD AND
CONTINUE THROUGH MID/LATE WEEK. SFC HIGH PRESSURE WILL CONTINUE TO
BUILD NORTH TUE NIGHT EXTENDING OVER THE AREA THROUGH LATE WEEK.
THIS COMBINED WITH CAA WILL RESULT IN N/NE WINDS 15-25KT TUE NIGHT
BECOMING NE 15-20KT WED. ELEVATED SEAS OF 4-6FT LIKELY CONTINUE
THROUGH THU. NE FLOW CONTINUES THROUGH THU NIGHT...SLOWLY VEERING
AND BECOMING SLY FRI NIGHT AS COLD FRONT APPROACHES FROM THE WEST. A
COLD FRONT WILL MOVE THROUGH THE WATERS LATE SAT/SAT NIGHT. SW
WINDS WILL INCREASE TO 15-25KT AHEAD OF THE FRONT SAT...BECOMING
NW BEHIND THE FRONT.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 1 AM TO 10 PM EST TUESDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 1 AM TO 4 PM EST TUESDAY FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THURSDAY FOR AMZ152-154-
156-158.
SMALL CRAFT ADVISORY UNTIL 10 AM EST THURSDAY FOR AMZ150.
&&
$$
SYNOPSIS...CTC
NEAR TERM...JBM/CTC
SHORT TERM...CTC
LONG TERM...CQD
AVIATION...BM/CQD
MARINE...JBM/CTC/CQD
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
100 PM EST MON NOV 18 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE OFFSHORE THIS AFTERNOON. COOL HIGH PRESSURE
WILL THEN BUILD OVER THE REGION THROUGH THE REMAINDER OF THE WORK
WEEK. ANOTHER COLD FRONT WILL MOVE ACROSS THE AREA SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1245 PM MONDAY...MINOR UPDATE FOR LATEST TRENDS. PCPN HAS
DRIED UP BUT LATEST HRRR STILL INDICATES LINGERING SCT SHOWER THREAT
S COAST LATE AFTN...THUS WILL CONTINUE 30 POP REST OF AFTN THERE.
RAISED TEMPS A FEW DEGS WITH SOME SRN SECTIONS INTO UPR 70S.
/PREVIOUS DISCUSSION/
AS OF 705 AM MONDAY...HAVE SPED UP PRECIPITATION AS FRONT ALREADY
APPROACHING THE RALEIGH AREA AND BROKEN LINE OF SHOWERS MOVING
INTO OUR WESTERN CWA. HAVE SCALED BACK POPS TO 30 PCT AS COVERAGE
WILL BE LIMITED AND THINK THE BULK OF THE RAIN WILL BE THROUGH
THE AREA BY MID TO LATE MORNING. TEMPERATURES OFF TO A WARM
START THIS MORNING WITH SEVERAL STATIONS AROUND 70 AND EXPECT
READINGS INTO THE MID 70S AT MANY SITES AHEAD OF THE FRONT. BY
MID- AFTERNOON...EXPECTING GUSTY N/NNE WINDS WITH TEMPS LEVELLING
OFF THEN FALLING LATE DURING THE DAYLIGHT HOURS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 355 AM MONDAY...SKIES SHOULD BECOME CLEAR BY SHORTLY AFTER
DARK WITH NORTHERLY BREEZES BRINGING IN COOLER AND DRIER AIR. FOR
LOW TEMPERATURES TONIGHT...MOST AREAS AWAY FROM THE IMMEDIATE
COAST WILL BE IN THE LOW TO MID 40S WITH TEMPERATURES RIGHT AROUND
50 OVER THE OUTER BANKS.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 3 AM MON...STRONG SURFACE RIDGING WILL BUILD ACROSS EASTERN
NC FROM THE NORTH TUES INTO WED WHILE UPPER RIDGING WILL ALSO
BUILD OVER THE REGION FROM THE WEST. MODEST CAA WITH LOW LEVEL
THICKNESSES FALLING TO 1315-1525 METERS EACH DAY WILL YIELD TEMPS
7-8 DEGREES BELOW CLIMO FOR MID NOVEMBER WITH HIGHS ONLY IN THE
MID/UPPER 50S. OVERNIGHT LOWS WILL REACH NEAR FREEZING TUES NIGHT
THEN MODERATE INTO THE UPPER 30S WED NIGHT. GUIDANCE CONTINUES TO
INDICATE WEAK SHORTWAVE ALOFT IN MEAN WESTERLY FLOW MAY PRODUCE
SOME LIGHT SHOWERS FOR COASTAL REGIONS WED AND HAVE MAINTAINED
SLIGHT CHANCE FOR THE CENTRAL OBX/COASTAL WATERS.
BY WED NIGHT...THE SURFACE RIDGE TO THE NORTH WILL SHIFT OVER NEW
ENGLAND AND NOSE SOUTH OVER THE REGION...PRODUCING NE FLOW. RIDGE
THEN SHIFTS OFF THE SOUTHERN NEW ENGLAND COAST THURS/FRI WITH
UPPER RIDGING PERSISTING OVER THE REGION. 850 MB FLOW BECOMES SSW
THUR/FRI WITH SURFACE FLOW REMAINS NE YIELDING CLOUDS AND POSSIBLE
PRECIP MAINLY NEAR THE COAST. SURFACE RETURN FLOW SETS UP FRI AS
THE HIGH SHIFTS OFFSHORE AND A COLD FRONT APPROACHES FROM THE NW
ALLOWING LOW LEVEL THICKNESSES TO BUILD 1360-1370 METERS WITH
TEMPS IN THE MID 60S. KEPT FRI DRY AND BEGAN TREND OF INCREASING
POPS FRI NIGHT AS FRONT SLOWLY SAGS SE OVER THE REGION. SAT SHOULD
REMAIN MILD TEMPERATURE-WISE WITH CHANCE POPS/SCATTERED SHOWERS.
COLD FRONT WILL PUSH OFF THE COAST SAT NIGHT WITH STRONG HIGH
PRESSURE BUILDING IN BEHIND THE FRONT ON SUN. TEMPS SUN WILL BE
COOLER WITH HIGHS IN THE LOW TO MID 50S.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH 18Z TUESDAY/...
AS OF 1230 PM MONDAY...HIGH CONFIDENCE OF VFR CONDITIONS WILL
DOMINATE THE TAF PERIOD. ONCE THE COLD FRONT CROSSES THE
AREA...DRIER AIR WILL AID TO DISSIPATE THE REMAINING CLOUD COVERAGE
IN THE AREA. HIGH PRESSURE WILL BUILD OVERNIGHT...RESULTING WITH A
TIGHTEN PRESSURE GRADIENT AND INHIBITING ANY FOG/LOW STRATUS
DEVELOPMENT. WINDS WILL INCREASE TO 10 GUSTING UP TO 15 KT TOMORROW
MORNING WITH MOSTLY CLEAR SKIES.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 305 AM MON...VFR CONDITIONS WILL PREVAIL THROUGH THE LONG
TERM. HIGH PRESSURE WILL BUILD OVER THE REGION TUES THROUGH MID
WEEK WITH OVERALL DRY AIRMASS AND THUS NO IMPACTS ON AVIATION
EXPECTED.
&&
.MARINE...
.SHORT TERM /THROUGH TONIGHT/...
AS OF 1245 PM MONDAY...NO CHANGES WITH UPDATE.
/PREVIOUS DISCUSSION/
AS OF 705 AM MONDAY...NO MAJOR CHANGES TO CURRENT MARINE FORECAST
AS SOUTHWEST WINDS OF 15 TO 20 KNOTS SHOULD GRADUALLY BECOME NW BY
EARLY AFTERNOON. EVEN THOUGH WIND AND WAVE MODELS INDICATE THAT
WINDS/SEAS WILL DIMINISH BELOW SMALL CRAFT ADVISORY FOR A FEW
HOURS LATE THIS AFTERNOON AND EVENING...WINDS AND SEAS ABRUPTLY
INCREASE WITH STRONG CAA BEHIND COLD FRONT TONIGHT AND HAVE OPTED
TO KEEP SMALL CRAFT ADV FOR THE COASTAL WATERS TODAY...TONIGHT AND
INTO MID WEEK GIVEN THE GUSTY N/NE WINDS AND ROUGH SEAS. THE
FRONTAL PASSAGE SHOULD OCCUR FOR THE COASTAL WATERS AROUND 18Z OR
SO WITH WINDS VEERING FROM S/SW EARLY THIS MORNING TO WNW/NW BY
EARLY AFTERNOON.
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 310 AM MON...A PROLONGED PERIOD OF SMALL ADVISORY CONDITIONS
ARE EXPECTED THROUGH THE PERIOD. SURFACE RIDGE SHIFTS OVER NEW
ENGLAND THEN OFF THE NEW ENGLAND COAST BY LATE WEEK. NORTHERLY WINDS
REMAIN 15-25 KT TUES DUE TO STRONG CAA...THEN WINDS SHIFT NE TUES
NIGHT INTO WED AND BECOME 10-20 KT. GRADIENT DIMINISHES FURTHER
WED/THURS WITH WINDS DIMINISH 10-15 KT AND SLOWLY VEERING ENE
THROUGH THURS. SEAS REMAIN ELEVATED 5-7 FT TUES INTO THURS. SEAS
SHOULD SUBSIDE BELOW 6 FT FOR THE SOUTHERN WATERS BY WED THEN FOR
ALL WATERS BY THURS NIGHT/FRI MORNING.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST WEDNESDAY FOR
AMZ150-152- 154-156.
SMALL CRAFT ADVISORY UNTIL 7 PM EST TUESDAY FOR AMZ158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC/JBM
SHORT TERM...CTC
LONG TERM...DAG
AVIATION...CTC/BM
MARINE...CTC/DAG/JBM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1250 AM EST MON NOV 18 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION FROM THE WEST EARLY THIS MORNING.
HIGH PRESSURE WILL BUILD INTO THE CAROLINAS FROM THE NORTHWEST THIS
AFTERNOON AND INFLUENCE OUR WEATHER THROUGH WEDNESDAY.
&&
.NEAR TERM /OVERNIGHT/...
AS OF 945 PM SUNDAY...
OVERVIEW:
A NEGATIVELY TILTED UPPER LEVEL TROUGH AND ATTENDANT SFC LOW OVER
THE GREAT LAKES WILL TRACK NORTHEAST INTO ONTARIO/QUEBEC...WHILE AN
ASSOCIATED COLD FRONT PROGRESSES RAPIDLY EAST THROUGH THE SOUTHERN
APPALACHIANS INTO CENTRAL/WESTERN PORTIONS OF THE MID-ATLANTIC AND
CAROLINAS BY 12Z MON.
PRECIPITATION CHANCES:
SCATTERED SHOWER ACTIVITY ASSOCIATED WITH WARM ADVECTION AND
MARGINAL ELEVATED INSTABILITY DOWNSTREAM OF THE APPROACHING
LOW-LEVEL TROUGH /COLD FRONT/ OVER THE TN VALLEY WILL WEAKEN SHORTLY
AFTER 06Z AS LOW-LEVEL FLOW VEERS TO A MORE WESTERLY DIRECTION AND A
DRIER MID-LEVEL AIRMASS (PER 00Z UPSTREAM RAOB DATA SUCH AS KOHX)
BEGINS TO ADVECT INTO THE REGION. ASIDE FROM THE POTENTIAL FOR A
SMALL AMPLITUDE DISTURBANCE IN WSW FLOW ALOFT...ANTICIPATE LITTLE IN
THE WAY OF UPPER LEVEL FORCING AS THE AMPLIFYING UPPER LEVEL WAVE
OVER THE GREAT LAKES TRACKS FURTHER AWAY FROM THE REGION INTO
CANADA. WITH THE ABOVE IN MIND...EXPECT SCATTERED ELEVATED SHOWER
ACTIVITY TO PERSIST THROUGH ~06Z. THEREAFTER...A SHORT LULL IN
ACTIVITY MAY BE POSSIBLE BEFORE CHANCES INCREASE ONCE AGAIN IN
ASSOC/W A NARROW SW-NE ORIENTED LINE OF LOW-TOPPED CONVECTION
EXPECTED TO PROGRESS INTO WESTERN PORTIONS OF THE AREA BY 12Z AS THE
COLD FRONT /LOW-LEVEL TROUGH/ APPROACH.
THUNDERSTORM POTENTIAL:
RECENT REMOTE SENSING DATA INDICATED A FEW ISOLD LIGHTNING STRIKES
IN UPSTATE SC WHERE LOW-LEVEL WARM ADVECTION AND ELEVATED
INSTABILITY ARE PRESUMABLY STRONGER...AS SUGGESTED BY 01Z SPC
MESOANALYSIS DATA. AN ISOLD LIGHTNING STRIKE CANNOT BE RULED OUT
WITH ELEVATED SHOWER ACTIVITY THROUGH ~06Z...PRIMARILY IN SOUTHERN
PORTIONS OF THE AREA. ALTHOUGH THE LATEST RAP MODEL DATA INDICATES
THAT STRENGTHENING SOUTHERLY FLOW WILL BEGIN TO ADVECT A MARGINALLY
UNSTABLE SURFACE BASED AIRMASS (CHARACTERIZED BY SFC DEWPOINTS IN
THE MID/UPPER 60S AND MLCAPE OF 250-500 J/KG) INTO PORTIONS OF
CENTRAL NC BY 09Z...IT SEEMS LIKELY THAT A SHALLOW NEAR-SFC STABLE
LAYER WILL REMAIN IN PLACE DUE TO PRIOR SHOWER ACTIVITY AND ONGOING
NOCTURNAL EFFECTS. THIS...IN ADDITION TO WEAK UPPER LEVEL FORCING
AND MID-LEVEL DRYING SHOULD PRECLUDE ANY POTENTIAL FOR SFC-BASED
CONVECTION /SEVERE WEATHER/ AS THE LOW-LEVEL TROUGH APPROACHES
WESTERN PORTIONS OF THE AREA BY SUNRISE.
TEMPERATURES:
AS SOUTHERLY FLOW STRENGTHENS EXPECT TEMPERATURES TO SLOWLY RISE
OVERNIGHT...INTO THE UPPER 60S TO NEAR 70F IN THE FAR S/SE AND INTO
THE MID 60S IN THE N/NW. -VINCENT
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 325 PM SUNDAY...
THE COLD FRONT IS EXPECTED TO PUSH QUICKLY EAST OF THE TRIANGLE
THROUGH THE SOUTHEAST CWA MONDAY MORNING. MUCH DRIER AIR WILL PUSH
IN QUICKLY BEHIND THE FRONT... WITH STRONG SUBSIDENCE AND CLEARING
SKIES AS SURFACE HIGH PRESSURE BUILDS IN FROM THE WEST. EXPECT A
TRANSITION FROM THICK CLOUDY SKIES RAPIDLY TO MOSTLY SUNNY SKIES...
WITH LINGERING SCATTERED CLOUDS BASED AROUND 6000 FT AGL INTO THE
AFTERNOON. THICKNESSES FALL SLOWLY THROUGH THE DAY... WITH A MUCH
MORE PRECIPITOUS DROP LATE IN THE DAY THROUGH MONDAY NIGHT... MAKING
TEMPS DIFFICULT TO PINPOINT. IN FACT.. CURRENT TEMPS IMMEDIATELY
BEHIND THE FRONT ARE STILL IN THE 70S. EXPECT HIGHS FROM 68 NW (WITH
A RISE OF UNDER 10 DEGREES THROUGH THE DAY) TO 75 SOUTHEAST. WINDS
NW AROUND 10-15 MPH. COLDER AIR RUSHES IN BY EVENING AND LASTS
THROUGH THE NIGHT... ALTHOUGH THE COLD AIR ADVECTION AND CLEAR SKIES
WILL BE TEMPERED BY THE CONTINUED MIXING OVERNIGHT. LOWS 36-42. -GIH
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 250 PM SUNDAY...
HIGH PRESSURE WILL BUILD FROM THE MIDWEST TOWARD NEW ENGLAND TUESDAY
AND WEDNESDAY AS AN UPPER RIDGE BUILDS ALONG THE EAST COAST. THE
SURFACE HIGH IS THEN FORECAST TO PERSIST MOST OF THE
WEEK...SUPPLYING COOL AIR AND POTENTIAL COLD AIR DAMMING AS MOISTURE
BEGINS TO INCREASE FROM THE WEST-SOUTHWEST AHEAD OF A SLOW MOVING
COLD FRONT. WHILE MOST OF THE MOISTURE AND PRECIP ASSOCIATED WITH
THE SLOWING COLD FRONT SHOULD STAY WEST OF THE MOUNTAINS...MODELS
SUGGEST SOME LIGHT PRECIP MAY SPREAD ACROSS THE MOUNTAINS BY
FRIDAY...WHICH MAY HELP TO REINFORCE THE WEAK CAD PRIOR TO THE COLD
FRONT FINALLY BEING PUSHED EAST BY A STRONGER SHORTWAVE DIGGING
THROUGH THE GREAT LAKES ON SATURDAY. WILL LEAVE POPS OUT FOR
FRIDAY BUT INCLUDE A CHANCE POP ON SATURDAY. 1000-850MB THICKNESSES
BOTTOM OUT AROUND 1310M TUESDAY/WEDNESDAY MORNING...WHICH WOULD
YIELD HIGHS IN THE MID 50S AND LOWS IN THE UPPER 20S AND LOWER 30S
WEDNESDAY MORNING. WILL THEN ERR ON THE COOLER SIDE OF GUIDANCE FOR
TEMPS THURSDAY THROUGH SATURDAY...WITH HIGHS IN THE LOW TO MID 50S
WEST AND LOW TO MID 60S EAST. LOWS SHOULD BE MOSTLY IN THE UPPER
30S AND LOWER 40S.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AS OF 1250 AM MONDAY...
WIDESPREAD LIFR/IFR CONDITIONS WILL PREVAIL ACROSS CENTRAL NC
THROUGH 10-12Z AS SLY FLOW IN THE LOWER LEVELS OF THE ATMOSPHERE
MAINTAINS A WARM MOIST AIR MASS. SCATTERED SHOWERS WILL BECOME MORE
LIKELY AFTER 08Z AS A COLD FRONT MOVES INTO OUR REGION FROM THE
WEST. THE COLD FRONT SHOULD CROSS THE TRIAD TERMINALS BETWEEN
10-11Z...THE KRDU VICINITY AROUND 12Z...AND KRWI AND KFAY BETWEEN
13-14Z. THE PASSAGE OF THE FRONT WILL BE NOTED BY SURFACE WINDS
VEERING TO THE NW. AHEAD AND BEHIND THE FRONT...EXPECT SURFACE WIND
GUSTS AROUND 20KTS.
DRIER MORE STABLE AIR WILL OVERSPREAD CENTRAL NC FROM THE NW BEHIND
THE FRONT. THIS WILL INITIATE RAPID CLEARING WITH SKIES BECOMING
MOSTLY CLEAR NW-SE BETWEEN 11Z-15Z.
HIGH PRESSURE WILL BUILD INTO THE CAROLINAS THIS AFTERNOON AND
TONIGHT AND LINGER OVER THE REGION TUESDAY INTO WEDNESDAY. THIS
WEATHER SYSTEM WILL BE ACCOMPANIED BY VFR CONDITIONS.
A RETURN FLOW OF MOISTURE AND AN APPROACHING FRONTAL SYSTEM WILL
BRING THE NEXT THREAT FOR SUB-VFR PARAMETERS THURSDAY INTO
FRIDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...VINCENT
SHORT TERM...HARTFIELD
LONG TERM...SMITH
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1231 AM EST MON NOV 18 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE OFF THE CAROLINA COAST TODAY AS COLD CANADIAN
HIGH PRESSURE BUILDS OVER THE REGION THROUGH THE MIDDLE OF THE WEEK.
THE NEXT COLD FRONT IS EXPECTED TO REACH OUR AREA NEXT SATURDAY.
&&
.NEAR TERM /THROUGH TODAY/...
0530 UTC UPDATE...POPS WERE ADJUSTED PER RADAR TRENDS...WITH A
DECREASE IN THE NC FOOTHILLS THE NEXT HOUR OR TWO. POPS WERE ALSO
ADJUSTED TO ACCOUNT FOR TIMING OF THE FRONTAL PASSAGE THIS MORNING.
QPF WAS ADJUSTED ACCORDINGLY...WITH A DECREASE IN THE FOOTHILLS..AND
A BIT MORE IN THE MOUNTAINS. WINDS WERE UPDATED FROM A BLENDED MODEL
DATA...PRESERVING GUSTS AT HIGH ELEVATIONS OVERNIGHT.
AS OF 920 PM...A SMALL CLUSTER OF THUNDERSTORMS WAS TRACKING ACROSS
CHESTER...SC AT 40 MPH. OTHERWISE...AREAS OF LIGHT RAIN AND HEAVY
DRIZZLE WILL REMAIN ACROSS THE FORECAST AREA THROUGH THE REST OF THE
EVENING. A THIN LINE OF ORGANIZED TSRA EXISTED ACROSS MIDDLE
KY/TN...TRACKING SE AT 35 MPH. AT THIS RATE...THE LEADING EDGE OF
THE LINE COULD REACH GRAHAM AND SWAIN COUNTIES AROUND 5Z.
HOWEVER...THE TN BORDER COUNTIES MAY THE GREATEST COVERAGE BETWEEN
5-7Z. THE LATEST RUN OF THE HRRR INDICATES THAT THE CONVECTION WILL
WEAKEN GRADUALLY ACROSS EASTERN TN...REACHING THE NC COUNTIES WILL
DECREASED REFLECTIVITY AND SHORTER LINE SEGMENTS. THE LATEST
MESOSCALE ANALYSIS INDICATES NO INSTABILITY ACROSS THE FORECAST
AREA. HOWEVER...A BAND OF WEAK VALUES OF CAPE MAY POOL ALONG AND
AHEAD OF THE CONVECTION. THE FORECAST AND HWO APPEARS ON TRACK.
AS OF 7 PM...AREAS OF RAIN AND HEAVY DRIZZLE WILL REMAIN ACROSS THE
FORECAST AREA THIS EVENING AND INTO EARLY MON MORNING. THE PRIMARY
FORECAST CONCERN WILL BE ASSOCIATED WITH THE PRE FRONTAL BAND OF
TSRA...LOCATED OVER MIDDLE AND WESTERN KY/TN. 22Z HRRR INDICATES
THAT THE BAND WILL APPROACH THE NC/TN LINE BY 7Z. THROUGH 9Z...HRRR
INDICATES THAT LINE SEGMENTS OF SHRA/TSRA WILL PUSH ACROSS THE
MTNS...TRACKING ACROSS THE NC FOOTHILLS. PRE FRONT NAM12 SHERB 0-3
KM VALUES RANGE FROM .6-.7. ALSO...0-3 KM EHI VALUES DECREASE FROM
.7-.4 M2/S2 FROM WEST TO EAST. I WOULD EXPECT THAT THE LINE OF
CONVECTION WILL CROSS THE SPINE OF THE APPALACHIANS LATE
TONIGHT...LARGELY INTACT. HOWEVER...THE ENVIRONMENT DOES NOT FAVOR
AN ORGANIZED BAND OF CONVECTION ACROSS THE THE FOOTHILLS AND
PIEDMONT. THE HWO APPEARS WELL WORDED...NO CHANGES PLANNED AT THIS
TIME. OTHERWISE...TEMPS SHOULD REMAIN NEARLY STEADY THIS EVENING AND
TONIGHT.
AS OF MID AFTERNOON...SHOWERS CONTINUE TO DEVELOP AND FILL IN ACROSS
NE GEORGIA...THE UPSTATE...AND THE NC FOOTHILLS...WHILE AN AREA OF
PRECIP MOVES ACRS THE NC MTNS FROM ERN TN. PRECIP CHANCES GRADUALLY
RAMP UP THROUGH THE REST OF THE DAYLIGHT HOURS TO ACCOUNT FOR THIS.
TEMPS ARE WARMER THAN EXPECTED ACROSS METRO CHARLOTTE...SO HIGH
TEMPS WERE RAISED THERE.
THE FIRST BATCH OF PRECIP WAS BEING DRIVEN BY THE PASSAGE OF A SHORT
WAVE...SEEN ON THE WATER VAPOR IMAGERY. THERE COULD BE A LULL IN
ACTIVITY MOVING IN FROM THE WEST THIS EVENING...ALTHO LOW LEVEL
MOISTURE AND FORCING WILL REMAIN IN PLACE. THIS DOES NOT LEAVE
ENOUGH CONFIDENCE TO TEMPORARILY LOWER THE PRECIP CHANCES AHEAD OF
THE FRONT...BUT SOME TWEAKING MIGHT BE DONE DURING THE EARLY EVENING
IF REDEVELOPMENT IS NOT SEEN. MOST SIGNS POINT TO A FRONTAL PASSAGE
DURING THE EARLY MORNING HOURS ACROSS MOST OF THE FCST AREA...WITH
THE FRONT STRETCHED OUT OVER THE PIEDMONT AT SUNRISE. THE MAIN ISSUE
IS THE SEVERE WEATHER POTENTIAL. ALTHO SHEAR WILL BE SUFFICIENT...
THE MODEL GUIDANCE CONTINUES TO FAIL TO GIVE MUCH IN THE WAY OF
INSTABILITY. ONLY THE SW MTNS GET EVEN MINIMAL AMOUNTS OF CAPE.
THUS...SOME WIND DAMAGE POTENTIAL CANNOT BE RULED OUT ON THE TN
BORDER THROUGH THE EARLY MORNING HOURS...BUT SEVERE WEATHER LOOKS
UNLIKELY ELSEWHERE. TEMPS WILL NOT FALL OFF MUCH BEFORE THE FRONT
ARRIVES...WHICH SHOULD LEAD TO AN UNSEASONALLY MILD NIGHT OVER THE
PIEDMONT.
THE FRONT SHOULD EXIT THE WESTERN PIEDMONT BY 13Z TO 14Z. A SMALL
POP WAS KEPT OVER THE EASTERN ZONES TO START THE DAY...BUT IS
QUICKLY DISPATCHED EASTWARD. EXPECT RAPID CLEARING MONDAY MORNING
BEHIND THE FRONT...BUT COOLER AIR WILL BE SLOW TO ARRIVE. DOWNSLOPE
E OF THE MTNS WILL ALLOW TEMPS TO CLIMB ABOVE NORMAL ONCE AGAIN WITH
GUSTY NW WIND IN THE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
AS OF 200 PM SUNDAY...A SPLIT QUASI-ZONAL FLOW PATTERN IS EXPECTED
IN THE UPR LVLS DURING THE SHORT TERM...WITH A SOUTHERN STREAM
SHORTWAVE TROF CROSSING THE CWFA TUESDAY NIGHT. MEANWHILE...DRY HIGH
PRES DRIFTS EAST FROM THE MIDWEST TO THE EASTERN SEABOARD BY 00Z
THURSDAY. FCST SNDGS SHOW SOME MAINLY UPR LVL MOISTURE STREAMING
ACRS THE AREA AHEAD OF THE SHORTWAVE TUESDAY EVENING. BUT IT LOOKS
VERY DRY BELOW 600 MB. SO NO PRECIP IS EXPECTED...DESPITE STRONG QG
FORCING WITH THE WAVE...JUST A PERIOD OF SOME BKN-OVC SKIES
POSSIBLE. TEMPS WILL GENERALLY BE SEVERAL DEGREES BELOW NORMAL BOTH
TUESDAY AND WEDNESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 200 EST PM SUNDAY...THE GLOBAL MODELS ARE IN FAIR AGREEMENT
WITH THE OVERALL SYNOPTIC PATTERN FOR THE MEDIUM RANGE PERIOD.
WEAK UPPER RIDGING WILL PERSIST ACROSS THE SE WED NIGHT INTO FRIDAY
AS 588 DM ANTICYCLONE BUILDS ACROSS THE GULF OF MEXICO AND SLOWLY
RETROGRADES THRU THE PERIOD. AN UPPER LOW PRESSURE TROUGH OVER SOUTH
CENTRAL CANADA ON FRI WILL THEN DIGS SOUTHEAST INTO THE GREAT LAKES
REGION FRI NIGHT...AND INTO THE SOUTHEASTERN STATES BY SAT. THE
TROUGH AXIS IS EXPECTED TO CROSS THE FORECAST AREA SUN AND OFF THE
ATLANTIC COAST BY SUN NIGHT.
AT THE SURFACE...CANADIAN HIGH PRESSURE CENTERED ACROSS NEW ENGLAND
WILL CONTINUE TO RIDGE INTO THE CWA WED NIGHT INTO
THURSDAY...ALLOWING COOL NE FLOW TO PERSIST THRU THE PERIOD. BY
FRIDAY...MOIST RETURN S/SE FLOW WILL SET UP ACROSS THE AREA AS THE
HIGH SHIFTS EAST OF THE AREA AND A COLD FRONT APPROACHES FROM THE
WEST. WITH INCREASING MOIST ISENTROPIC LIFT...POPS RAMP UP TO 20/30
PERCENT TOWARD FRI AFTERNOON. THE GFS PUSHES THE FRONT THROUGH THE
REGION FRI NIGHT INTO SAT MORNING WHILE THE SLOWER 12Z ECMWF PUSHES
IT DURING THE DAY ON SAT. BOTH THE GFS/ECMWF GENERATE ABOUT
0.25-0.5" OF QPF DURING THE FROPA. TAKING A COMPROMISE...POPS REMAIN
IN THE 30/40 PERCENT RANGE FRI NIGHT THRU EARLY SAT. CONDITIONS DRY
OUT BY SAT NIGHT AS THE FRONT PUSHES OFFSHORE AND DRY CANADIAN HIGH
BUILDS IN FROM THE WEST. TEMPERATURES WILL REMAIN 3-5 DEGREE BELOW
NORMAL THRU THURSDAY BEFORE WARMING UP TO NEAR NORMAL RANGE BY FRI.
TEMPS THEN DROP CONSIDERABLY TO 7-10 BELOW NORMAL ON SUN AS COLD
CANADIAN HIGH BUILDS IN.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
AT KCLT...MODEL GUIDANCE SUPPORTS CIG FALLING FROM IFR TO LIFR OR
EVEN VLIFR BY DAYBREAK IN A MOIST AIR MASS AHEAD OF A COLD FRONT.
FOR NOW WILL ALLOW CIG TO FALL TO LIFR. VSBY SHOULD REACH MVFR AS
WELL. SHOWERS WILL ACCOMPANY THE FRONT...BUT THUNDER CHANCES ARE TOO
LOW TO MENTION. FRONTAL PASSAGE WILL BE SOME TIME AROUND DAWN...
FOLLOWED WINDS VEERING SW TO NW AND BECOMING GUSTY...WITH
RESTRICTIONS ENDING. WINDS VEER TO THE N TONIGHT AND LOSE MUCH OF
THEIR GUSTINESS.
ELSEWHERE...RESTRICTIONS WILL LOWER AS A COLD FRONT AND ITS
ASSOCIATED PRECIPITATION MOVE INTO THE AREA FROM THE WEST OVERNIGHT.
GUIDANCE HINTS AT VLIFR CIGS AT MANY SITES...BUT CONFIDENCE IS
LIMITED...AND ONLY IFR WILL BE CARRIED AT KAVL...WITH LIFR AT
FOOTHILLS SITES. GUIDANCE SUPPORTS IFR CIGS AT ALL SITES. FRONTAL
PASSAGE WILL BE BEFORE DAWN. THUNDER CHANCES ARE ONLY ENOUGH FOR A
MENTION AT KAND. WINDS WILL VEER FROM SW TO NW WITH FRONTAL PASSAGE
BEFORE DAWN...BUT SPEEDS WILL BE TOO LOW TO MIX OUT RESTRICTIONS
UNTIL AFTER DAYBREAK. NW WINDS BECOME GUSTY DURING THE DAY...THE
VEER TO THE N TONIGHT WITH GUSTS DECREASING.
OUTLOOK...VFR FROM MONDAY NIGHT THROUGH THE MIDDLE OF THE UPCOMING
WEEK.
CONFIDENCE TABLE...
05-11Z 11-17Z 17-23Z 23-05Z
KCLT LOW 55% MED 65% MED 71% HIGH 95%
KGSP MED 78% MED 76% MED 77% MED 72%
KAVL MED 78% MED 65% HIGH 84% HIGH 89%
KHKY HIGH 81% HIGH 85% MED 74% MED 74%
KGMU MED 77% MED 75% MED 76% HIGH 80%
KAND HIGH 83% MED 65% HIGH 89% HIGH 87%
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_TABLES
&&
.FIRE WEATHER...
A LINE OF THUNDERSTORMS IS EXPECTED TO MOVE ACROSS THE NORTH
CAROLINA MOUNTAINS EARLY MONDAY MORNING. WHILE THE LINE SHOULD
WEAKEN AS IT CROSSES THE MOUNTAINS...THE ACCOMPANYING OUTFLOW
BOUNDARY WOULD RESULT IN WINDS RAPIDLY SHIFTING TO THE WEST OR
NORTHWEST. OVER THE LINVILLE GORGE THIS IS MOST LIKELY TO HAPPEN
BETWEEN 1 AM AND 4 AM MONDAY. IN ADDITION TO SHIFTING WINDS...STRONG
WIND GUSTS ARE ALSO POSSIBLE WITH THE LINE.
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...JAT/NED/PM
SHORT TERM...ARK
LONG TERM...JOH
AVIATION...JAT
FIRE WEATHER...
AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
534 PM CST TUE NOV 19 2013
.UPDATE...
FORECAST APPEARS TO BE ON TRACK THIS EVENING. NO MAJOR CHANGES
PLANNED AT THIS TIME. SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT
QUITE A CHANGE COMING IN THE SHORT TERM FROM THIS AFTERNOON
THROUGH THURSDAY NIGHT. FOR TONIGHT...EXPECT RR QUAD JET INDUCED
HIGH CLOUDS TO MOVE ON THIS EVENING WHILE MORE HIGH CLOUDS SPREAD
IN FROM THE WEST. BREEZY SOUTH WINDS WILL DECREASE THIS EVENING
WITH WINDS BECOMING NORTHWEST THROUGH NORTH BY MORNING AS A WEAK
SURFACE LOW PRESSURE TROUGH MOVES THROUGH. TEMPERATURES WILL NOT
FALL OFF MUCH TONIGHT WITH THE MILD AIR MASS REMAINING. LOWS ARE
EXPECTED TO RANGE FROM AROUND 30 DEGREES NORTH CENTRAL TO THE MID
TO UPPER 30S IN THE WATERTOWN/ORTONVILLE AREA. OTHERWISE...HIGHS
ON WEDNESDAY WILL LIKELY BE IN THE MORNING AS AN ARCTIC BOUNDARY
PUSHES IN DURING THE AFTERNOON WITH NORTH WINDS PICKING UP AND
TEMPERATURES FALLING ACROSS THE NORTH. EXPECT WINDS TO BECOME
BLUSTERY AT 15 TO 30 MPH WITH HIGHER GUSTS. THE OTHER ISSUE WILL
BE THE LIGHT SNOW DEVELOPING ALONG AND BEHIND THE SURFACE COLD
FRONT. MID LEVEL FRONTOGENESIS ALONG WITH SOME JET STREAK HELP
WILL BRING LIGHT SNOW TO NORTH CENTRAL SOUTH DAKOTA BY LATE
AFTERNOON. THE MODELS INDICATE LESSER AMOUNTS OF LIFT AND QPF AS
THIS REGION DESCENDS SOUTH ACROSS OUR CWA THROUGH WEDNESDAY NIGHT.
THUS...HAVE LIKELY CHANCES EARLY DIMINISHING THROUGH THE NIGHT.
SNOWFALL AMOUNTS SHOULD BE GENERALLY BELOW AN INCH BY THURSDAY
MORNING. ARCTIC AIR ENCOMPASSES THE ENTIRE CWA ON THURSDAY WITH
LESS WIND. MUCH BELOW NORMAL TEMPERATURES ARE EXPECTED ON
THURSDAY WITH HIGHS IN THE 20 TO 25 DEGREE RANGE ACROSS THE CWA.
THE MODELS THEN SHOW AN UPPER LEVEL LOW PRESSURE TROUGH AND THE
ASSOCIATED LIFT SWINGING OVER THE REGION THURSDAY AND THURSDAY
EVENING. WITH MUCH OF THE NORTHERN CWA UNDER LOW LEVEL DRY
AIR...EXPECT THE BEST CHANCES OF LIGHT SNOW WITH THIS SYSTEM TO
BE FROM PIR TO HURON TO ATY. EXPECT MORE CLOUD COVER AND LIGHT
SNOW TO SPREAD QUICKLY WEST TO EAST ON THURSDAY ACROSS MAINLY THE
SOUTHERN CWA. COULD HAVE SOME MORE SNOWFALL ACCUMULATIONS OF AN INCH
OR TWO. THE LIGHT SNOW WILL END QUICKLY THURSDAY NIGHT WITH
CLEARING SKIES IN BEHIND AND SINGLE DIGIT LOWS.
.LONG TERM...FRIDAY THROUGH TUESDAY
NORTHWEST FLOW ALOFT WILL DOMINATE THE LONG TERM PORTION OF THE
FORECAST. A SURFACE LOW PRESSURE SYSTEM PASSING ACROSS THE GREAT
LAKES REGION ON FRIDAY WILL ALLOW FOR BITTER ARCTIC COLD
TEMPERATURES TO FILTER INTO THE AREA BY FRIDAY NIGHT. BY 12Z
SATURDAY TEMPERATURES AT H85 RANGE IN THE MID TO UPPER TEENS BELOW
ZERO...WHICH IS APPROACHING TWO STANDARD DEVIATIONS BELOW NORMAL. LOW
TEMPERATURES SHOULD EASILY DROP TO THE SINGLE DIGITS ON EITHER
SIDE OF ZERO BY SATURDAY MORNING. THE SURFACE HIGH PRESSURE WILL
EXIT THE REGION ON SATURDAY NIGHT ALLOWING FOR WAA TO SPREAD INTO
THE CWA. TEMPERATURES THROUGH THE REST OF THE PERIOD WILL BE
AROUND NORMAL...DUE TO EXPECTED SNOW COVER. NO SIGNIFICANT
PRECIPITATION CHANCES ARE EXPECTED FOR THE PERIOD.
&&
.AVIATION...
00Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED THROUGH THE TAF PERIOD. WINDS ARE
DIMINISHING AT MOST SITES THIS EVENING...THOUGH KATY WILL REMAIN
AROUND 15 KTS OVERNIGHT. A LOW WILL BEGIN TO IMPACT THE REGION
WEDNESDAY EVENING. CIGS WILL BEGIN TO LOWER NEAR KPIR/KMBG TOWARD
THE END OF THE PERIOD. WINDS WILL SHIFT TO THE NORTH AND NORTHWEST
BEGINNING LATE WEDNESDAY AFTERNOON AND BECOME GUSTY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...MOHR
LONG TERM...SD
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION...UPDATED
NWS MEMPHIS TN
1104 PM CST SUN NOV 17 2013
.UPDATE...
UPDATED TO INCLUDE THE 06Z AVIATION DISCUSSION BELOW.
JCL
&&
.DISCUSSION... /ISSUED 917 PM CST SUN NOV 17 2013/
LINE OF SHOWERS AND ISOLATED THUNDERSTORMS CONTINUES TO PUSH
SOUTH INTO NORTH MISSISSIPPI. SKIES ARE CLOUDY ALONG AND AHEAD OF
THIS LINE BUT BEHIND THE LINE SKIES ARE CLEAR. TEMPERATURES RANGE
FROM THE UPPER 50S TO LOWER 70S. THE LINE OF SHOWERS SHOULD MOVE
THROUGH THE REMAINDER OF THE FORECAST AREA BY MIDNIGHT. HAVE
ADJUSTED POPS FOR THE EVENING HOURS. ALSO REMOVED MENTION OF FOG
OVERNIGHT AND INTO MONDAY MORNING.
ARS
PREV DISCUSSION... /ISSUED 542 PM CST SUN NOV 17 2013/
IN THE SHORT TERM...CLOUDY SKIES HANGING ON TOUGH ACROSS THE EAST
AND SOUTH WITH THE LOW LEVEL MOISTURE AXIS. TO THE NORTH AND WEST
MIDLEVEL DRY HAS SURGED AHEAD OF THE FRONTAL BOUNDARY AND HAS
PROVIDED MOSTLY CLEAR SKIES AND GOOD MIXING IN THE BOUNDARY LAYER
BUT LIKELY CAPPED JUST ABOVE. AS OF 20Z THE COLD FRONT/DRYLINE IS
NOW CROSSING LAWRENCE AND RANDOLPH COUNTIES WITH CONVECTION REALLY
STRUGGLING TO GET GOING DESPITE THE CLEARING AND DEWPOINTS NEAR
70F. WITH THIS SAID...THE NAM...GFS AND HRRR MODELS SHOW THE FRONT
BECOMING SOMEWHAT MORE ACTIVE ACROSS NORTHWEST TENNESSEE BETWEEN
21-00Z. THIS STILL SEEMS VERY CONDITIONAL AND ISOLATED AS MAX
TEMPERATURES WILL START TO FALL. WILL BE TRIMMING BACK THE CURRENT
TORNADO WATCH BY 4 PM FOR THE COUNTIES WEST OF THE RIVER.
FURTHER SOUTH...FEEL RAIN SHOWERS WILL BE MORE LIKELY ESPECIALLY
THIS EVENING AS THE TAIL OF THE FRONT PASSES THROUGH NORTHEAST
MISSISSIPPI. THE SOUTHWEST DELTA COUNTIES WILL HAVE THE LOWEST
RAIN CHANCES FOR THE REMAINDER OF THE DAY. SKIES WILL CLEAR OUT
ACROSS THE SOUTH DURING THE NIGHT WITH SOME PATCHY FOG POSSIBLE.
MONDAY THROUGH WEDNESDAY...SURFACE HIGH PRESSURE WILL KEEP THE
MIDSOUTH DRY WITH NEAR SEASONAL TEMPERATURES. WINDS WILL VEER FROM
NORTH ON MONDAY TO SOUTHEASTERLY ON WEDNESDAY. LOWS TUESDAY AND
WEDNESDAY MORNING WILL BE NEAR FREEZING OVER THE NORTH AND EAST.
WEDNESDAY NIGHT THROUGH SUNDAY...GFS AND ECMWF BECOMING MORE IN
LINE DURING THIS PERIOD THAT WAA AND ISENTROPIC LIFT WILL GENERATE
LIGHT RAIN SHOWER ACTIVITY ACROSS THE MIDWEST FIRST...AND THEN
EXTEND IT SOUTHWARD ON THURSDAY. THIS IS IN RESPONSE TO A
DESCENDING 1040MB SURFACE HIGH IN THE NORTHERN PLAINS...AS IT
GENERATES A NEW COLD FRONT OVER THE MIDWEST. THIS BOUNDARY IS
FORECASTED TO SLOWLY PUSH SOUTH THROUGH OUR AREA THURSDAY NIGHT
THROUGH FRIDAY AND INTO EARLY SATURDAY. THUS THE END OF THE WORK
WEEK LOOKS TO BE COOL AND WET. THOUGH WITH THE LACK OF ANY
SIGNIFICANT UPPER LEVEL SUPPORT THUNDERSTORMS WILL BE MINIMAL. AS
THE FRONT MOVES TOWARDS THE GULF COAST ON SATURDAY...NORTH WINDS
WILL KEEP THE WEEKEND HIGHS TEN TO FIFTEEN DEGREES BELOW
NORMAL...WITH MAINLY 40S TO LOW 50S.
JAB
&&
.AVIATION...
06Z TAF CYCLE (18/06Z-19/06Z)
A COLD FRONT WILL MOVE SOUTHEAST OF THE MIDSOUTH EARLY MONDAY MORNING
FOLLOWED BY MUCH DRIER AIR. AT KTUP...MVFR CONDITIONS WITH A FEW
SHOWERS AND PATCHY FOG MAY LINGER UNTIL ABOUT 07Z...OTHERWISE VFR
CONDITIONS ARE EXPECTED TO PREVAIL AT THE TAF SITES
(KMEM...KMKL...KJBR...AND KTUP) THROUGH THE PERIOD. WINDS TONIGHT
NW-N 6-7 KTS...WINDS MONDAY N 9-11 KTS...WINDS AFTER 19/00Z N-NE
4-6 KTS.
JCL
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 49 63 41 59 / 60 0 0 0
MKL 43 62 35 57 / 60 0 0 0
JBR 43 61 36 55 / 10 0 0 0
TUP 48 66 38 60 / 70 0 0 0
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
529 AM CST MON NOV 18 2013
.DISCUSSION...
SEE THE 12Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
THE FOG WAS BEGINNING TO LIFT AT BOTH KCLL AND KUTS AT 11Z AND
EXPECT BOTH TO BE MVFR BY 12Z. HOWEVER...THE IS A CHANCE THAT IFR
FOG MAY LINGER PAST 12Z. OTHERWISE...THE COLD FRONT THAT IS MOVING
SOUTHWARD AND HELPING TO LIFT THE FOG SHOULD ARRIVE AT KCXO AND
KIAH BY 14Z...15Z AT KHOU...16Z AT KSGR...17Z AT KLBX...AND 18Z AT
KGLS. LESS SURE OF THE TIMING AFTER THE FRONT PUSHES THROUGH THE
BIG METRO AIRPORTS. THIS AFTERNOON SHOULD SEE VFR CONDITIONS
DEVELOPING.
40
&&
.PREV DISCUSSION... /ISSUED 423 AM CST MON NOV 18 2013/
MARINE...
DENSE SEA FOG WILL LIKELY PERSIST THROUGH MUCH OF THE MORNING...
GIVEN THE WATER TEMPERATURES IN THE MID 60S BEING OVERRUN BY AN
AIR MASS WITH DEWPOINTS IN THE LOWER 70S. THE GFS MODEL
STATISTICAL GUIDANCE FOR GALVESTON INDICATES THAT THE SEA FOG WILL
PERSIST THROUGH MID MORNING AND THEN BEGIN LIFTING AS THE COLD
FRONT PUSHES OFF THE COAST. EXPECT THAT GALVESTON BAY WILL SEE
IMPROVEMENTS FIRST DURING THE MID MORNING PERIOD...FOLLOWED BY THE
GULF WATERS EAST OF FREEPORT DURING THE MID TO LATE MORNING. THE
WATERS WEST OF FREEPORT AND MATAGORDA BAY MAY EXPERIENCE THE SEA
FOG THROUGH NOON TIME.
BEHIND THE FRONT MODERATE TO STRONG NORTHEAST WINDS ARE EXPECTED
TO DEVELOP TONIGHT AND THEN SLOWLY DIMINISH THROUGH TUESDAY
NIGHT. AFTER A PERIOD OF ONSHORE WINDS...A STRONGER FRONT IS
EXPECTED TO PUSH OFF THE COAST ON FRIDAY.
PREV DISCUSSION... /ISSUED 347 AM CST MON NOV 18 2013/
DISCUSSION...
DENSE FOG CONTINUES TO BLANKET MUCH OF SOUTHEAST TEXAS THIS
MORNING. A WEAK COLD FRONT IS DRAPED ACROSS THE EXTREME NORTHERN
PART OF THE CWA AND IS DRIFTING SLOWLY SOUTH. AM EXPECTING A
GRADUAL IMPROVEMENT IN VISIBILITY OVER THE NORTH AS DRIER AIR
FILTERS INTO THE REGION. CROCKETT HAS ALREADY CLEARED OUT BUT
HUNTSVILLE IS STILL BELOW A 1/2 MILE. THE FRONT WILL MOVE THROUGH
SE TX TODAY BUT THE SLOW MOVEMENT WILL ALLOW FOGGY CONDS TO
PREVAIL ALONG THE COAST THROUGH LATE MORNING. WILL ADJUST THE
DENSE FOG ADVISORY RIGHT BEFORE SENDING THE ZFP TO TRY AND MATCH
UP WITH CURRENT OBS. THE BOUNDARY COULD ALSO TRIGGER A FEW SHOWERS
AS IT ENCOUNTERS DEEP MOISTURE CLOSER TO THE COAST. SATELLITE
DERIVED PW VALUES ARE NEAR 2.0 INCHES ALONG THE COAST AND THE RAP
AND HRRR WANT TO DEVELOP PRECIP ALONG THE BOUNDARY LATER THIS
MORNING. WILL MAINTAIN CHC/SLT CHC POPS FOR AREAS GENERALLY EAST
OF I-69.
TUESDAY LOOKS QUIET BUT MOISTURE BEGINS TO RETURN ON WEDNESDAY.
PWATS INCREASE TO 1.6 INCHES ON WED AND NAM 12 FCST SOUNDINGS SHOW
A DEEP SATURATED LAYER BETWEEN 900-600 MB. THE GFS IS LESS
AGGRESSIVE BUT STILL SHOWS A SATURATED LAYER BETWEEN 950-700 MB.
WILL MAINTAIN SLT RAIN CHANCES FOR MAINLY THE SW HALF OF THE
REGION. A WARM FRONT WILL MOVE ACROSS SE TX WED NITE AND THURSDAY.
SOME LIGHT RAIN WILL ACCOMPANY THE FRONT AS IT MOVES NORTH. A
WEAK UPPER LEVEL DISTURBANCE COUPLED WITH DEEPER MOISTURE WILL
YIELD A CHANCE OF SHOWERS ON THURSDAY.
MODELS IN BETTER AGREEMENT WITH THE TIMING AND STRENGTH OF THE NEXT
COLD FRONT. THE ECMWF IS STILL FASTER THAN THE GFS. THE GFS IS
TRENDING A BIT FASTER AND THE ECMWF IS TRENDING A BIT SLOWER SO
THE TIMING OF THE FROPA SHOULD BE DURING THE DAY ON FRIDAY. PWATS
INCREASE TO 1.8 INCHES AHEAD OF THE FRONT. JET DYNAMICS ARE
LACKING A BIT BUT THE FRONT SHOULD SERVE AS A CATALYST FOR
SHRA/TSRA. WILL MAINTAIN HIGH END CHC POPS FOR NOW. CONSIDERABLY
COLDER TEMPERATURES WILL MOVE INTO SE TX FOR THE WEEKEND.
ISENTROPIC UPGLIDE SHOULD PERSIST INTO SATURDAY MORNING AS SW
WINDS ALOFT OVERRIDE N-NE SFC WINDS. PRECIP SHOULD END ON SAT AFTN
AS A STRONG UPPER LOW OVER BAJA RETROGRADES SLIGHTLY AND THIS WILL
ALLOW WEAK RIDGING TO AMPLIFY OVER DEEP SOUTH TEXAS. AS A
RESULT...UPPER LEVEL WINDS BRIEFLY BECOME WEST AND END THE
ISENTROPIC LIFT. IT WILL REMAIN UNSEASONABLY COLD THROUGH THROUGH
THE WEEKEND. THE UPPER LOW WILL BEGIN TO MOVE EAST ON MONDAY AND
SW WINDS ALOFT REDEVELOP. THE UPPER LOW WILL MOVE ACROSS THE STATE
NEXT TUES AND A COASTAL LOW WILL DEVELOP OFF CORPUS. THE TWO
FEATURES SHOULD BRING A GOOD CHANCE OF RAIN TO THE REGION NEXT
TUESDAY. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 53 71 54 74 / 10 10 10 10 10
HOUSTON (IAH) 78 54 71 56 74 / 20 10 10 10 20
GALVESTON (GLS) 78 62 69 63 74 / 30 10 10 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...CHAMBERS...COLORADO...
FORT BEND...GALVESTON...GRIMES...HARRIS...JACKSON...
LIBERTY...MATAGORDA...MONTGOMERY...POLK...SAN JACINTO...
WALKER...WALLER...WASHINGTON...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.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
423 AM CST MON NOV 18 2013
.MARINE...
DENSE SEA FOG WILL LIKELY PERSIST THROUGH MUCH OF THE MORNING...
GIVEN THE WATER TEMPERATURES IN THE MID 60S BEING OVERRUN BY AN
AIR MASS WITH DEWPOINTS IN THE LOWER 70S. THE GFS MODEL
STATISTICAL GUIDANCE FOR GALVESTON INDICATES THAT THE SEA FOG WILL
PERSIST THROUGH MID MORNING AND THEN BEGIN LIFTING AS THE COLD
FRONT PUSHES OFF THE COAST. EXPECT THAT GALVESTON BAY WILL SEE
IMPROVEMENTS FIRST DURING THE MID MORNING PERIOD...FOLLOWED BY THE
GULF WATERS EAST OF FREEPORT DURING THE MID TO LATE MORNING. THE
WATERS WEST OF FREEPORT AND MATAGORDA BAY MAY EXPERIENCE THE SEA
FOG THROUGH NOON TIME.
BEHIND THE FRONT MODERATE TO STRONG NORTHEAST WINDS ARE EXPECTED
TO DEVELOP TONIGHT AND THEN SLOWLY DIMINISH THROUGH TUESDAY
NIGHT. AFTER A PERIOD OF ONSHORE WINDS...A STRONGER FRONT IS
EXPECTED TO PUSH OFF THE COAST ON FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 347 AM CST MON NOV 18 2013/
DISCUSSION...
DENSE FOG CONTINUES TO BLANKET MUCH OF SOUTHEAST TEXAS THIS
MORNING. A WEAK COLD FRONT IS DRAPED ACROSS THE EXTREME NORTHERN
PART OF THE CWA AND IS DRIFTING SLOWLY SOUTH. AM EXPECTING A
GRADUAL IMPROVEMENT IN VISIBILITY OVER THE NORTH AS DRIER AIR
FILTERS INTO THE REGION. CROCKETT HAS ALREADY CLEARED OUT BUT
HUNTSVILLE IS STILL BELOW A 1/2 MILE. THE FRONT WILL MOVE THROUGH
SE TX TODAY BUT THE SLOW MOVEMENT WILL ALLOW FOGGY CONDS TO
PREVAIL ALONG THE COAST THROUGH LATE MORNING. WILL ADJUST THE
DENSE FOG ADVISORY RIGHT BEFORE SENDING THE ZFP TO TRY AND MATCH
UP WITH CURRENT OBS. THE BOUNDARY COULD ALSO TRIGGER A FEW SHOWERS
AS IT ENCOUNTERS DEEP MOISTURE CLOSER TO THE COAST. SATELLITE
DERIVED PW VALUES ARE NEAR 2.0 INCHES ALONG THE COAST AND THE RAP
AND HRRR WANT TO DEVELOP PRECIP ALONG THE BOUNDARY LATER THIS
MORNING. WILL MAINTAIN CHC/SLT CHC POPS FOR AREAS GENERALLY EAST
OF I-69.
TUESDAY LOOKS QUIET BUT MOISTURE BEGINS TO RETURN ON WEDNESDAY.
PWATS INCREASE TO 1.6 INCHES ON WED AND NAM 12 FCST SOUNDINGS SHOW
A DEEP SATURATED LAYER BETWEEN 900-600 MB. THE GFS IS LESS
AGGRESSIVE BUT STILL SHOWS A SATURATED LAYER BETWEEN 950-700 MB.
WILL MAINTAIN SLT RAIN CHANCES FOR MAINLY THE SW HALF OF THE
REGION. A WARM FRONT WILL MOVE ACROSS SE TX WED NITE AND THURSDAY.
SOME LIGHT RAIN WILL ACCOMPANY THE FRONT AS IT MOVES NORTH. A
WEAK UPPER LEVEL DISTURBANCE COUPLED WITH DEEPER MOISTURE WILL
YIELD A CHANCE OF SHOWERS ON THURSDAY.
MODELS IN BETTER AGREEMENT WITH THE TIMING AND STRENGTH OF THE NEXT
COLD FRONT. THE ECMWF IS STILL FASTER THAN THE GFS. THE GFS IS
TRENDING A BIT FASTER AND THE ECMWF IS TRENDING A BIT SLOWER SO
THE TIMING OF THE FROPA SHOULD BE DURING THE DAY ON FRIDAY. PWATS
INCREASE TO 1.8 INCHES AHEAD OF THE FRONT. JET DYNAMICS ARE
LACKING A BIT BUT THE FRONT SHOULD SERVE AS A CATALYST FOR
SHRA/TSRA. WILL MAINTAIN HIGH END CHC POPS FOR NOW. CONSIDERABLY
COLDER TEMPERATURES WILL MOVE INTO SE TX FOR THE WEEKEND.
ISENTROPIC UPGLIDE SHOULD PERSIST INTO SATURDAY MORNING AS SW
WINDS ALOFT OVERRIDE N-NE SFC WINDS. PRECIP SHOULD END ON SAT AFTN
AS A STRONG UPPER LOW OVER BAJA RETROGRADES SLIGHTLY AND THIS WILL
ALLOW WEAK RIDGING TO AMPLIFY OVER DEEP SOUTH TEXAS. AS A
RESULT...UPPER LEVEL WINDS BRIEFLY BECOME WEST AND END THE
ISENTROPIC LIFT. IT WILL REMAIN UNSEASONABLY COLD THROUGH THROUGH
THE WEEKEND. THE UPPER LOW WILL BEGIN TO MOVE EAST ON MONDAY AND
SW WINDS ALOFT REDEVELOP. THE UPPER LOW WILL MOVE ACROSS THE STATE
NEXT TUES AND A COASTAL LOW WILL DEVELOP OFF CORPUS. THE TWO
FEATURES SHOULD BRING A GOOD CHANCE OF RAIN TO THE REGION NEXT
TUESDAY. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 53 71 54 74 / 10 10 10 10 10
HOUSTON (IAH) 78 54 71 56 74 / 20 10 10 10 20
GALVESTON (GLS) 78 62 69 63 74 / 30 10 10 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 AM CST THIS MORNING FOR THE FOLLOWING
ZONES: AUSTIN...BRAZORIA...BRAZOS...CHAMBERS...COLORADO...
FORT BEND...GALVESTON...GRIMES...HARRIS...JACKSON...
LIBERTY...MATAGORDA...MONTGOMERY...POLK...SAN JACINTO...
WALKER...WALLER...WASHINGTON...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.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
347 AM CST MON NOV 18 2013
.DISCUSSION...
DENSE FOG CONTINUES TO BLANKET MUCH OF SOUTHEAST TEXAS THIS
MORNING. A WEAK COLD FRONT IS DRAPED ACROSS THE EXTREME NORTHERN
PART OF THE CWA AND IS DRIFTING SLOWLY SOUTH. AM EXPECTING A
GRADUAL IMPROVEMENT IN VISIBILITY OVER THE NORTH AS DRIER AIR
FILTERS INTO THE REGION. CROCKETT HAS ALREADY CLEARED OUT BUT
HUNTSVILLE IS STILL BELOW A 1/2 MILE. THE FRONT WILL MOVE THROUGH
SE TX TODAY BUT THE SLOW MOVEMENT WILL ALLOW FOGGY CONDS TO
PREVAIL ALONG THE COAST THROUGH LATE MORNING. WILL ADJUST THE
DENSE FOG ADVISORY RIGHT BEFORE SENDING THE ZFP TO TRY AND MATCH
UP WITH CURRENT OBS. THE BOUNDARY COULD ALSO TRIGGER A FEW SHOWERS
AS IT ENCOUNTERS DEEP MOISTURE CLOSER TO THE COAST. SATELLITE
DERIVED PW VALUES ARE NEAR 2.0 INCHES ALONG THE COAST AND THE RAP
AND HRRR WANT TO DEVELOP PRECIP ALONG THE BOUNDARY LATER THIS
MORNING. WILL MAINTAIN CHC/SLT CHC POPS FOR AREAS GENERALLY EAST
OF I-69.
TUESDAY LOOKS QUIET BUT MOISTURE BEGINS TO RETURN ON WEDNESDAY.
PWATS INCREASE TO 1.6 INCHES ON WED AND NAM 12 FCST SOUNDINGS SHOW
A DEEP SATURATED LAYER BETWEEN 900-600 MB. THE GFS IS LESS
AGGRESSIVE BUT STILL SHOWS A SATURATED LAYER BETWEEN 950-700 MB.
WILL MAINTAIN SLT RAIN CHANCES FOR MAINLY THE SW HALF OF THE
REGION. A WARM FRONT WILL MOVE ACROSS SE TX WED NITE AND THURSDAY.
SOME LIGHT RAIN WILL ACCOMPANY THE FRONT AS IT MOVES NORTH. A
WEAK UPPER LEVEL DISTURBANCE COUPLED WITH DEEPER MOISTURE WILL
YIELD A CHANCE OF SHOWERS ON THURSDAY.
MODELS IN BETTER AGREEMENT WITH THE TIMING AND STRENGTH OF THE NEXT
COLD FRONT. THE ECMWF IS STILL FASTER THAN THE GFS. THE GFS IS
TRENDING A BIT FASTER AND THE ECMWF IS TRENDING A BIT SLOWER SO
THE TIMING OF THE FROPA SHOULD BE DURING THE DAY ON FRIDAY. PWATS
INCREASE TO 1.8 INCHES AHEAD OF THE FRONT. JET DYNAMICS ARE
LACKING A BIT BUT THE FRONT SHOULD SERVE AS A CATALYST FOR
SHRA/TSRA. WILL MAINTAIN HIGH END CHC POPS FOR NOW. CONSIDERABLY
COLDER TEMPERATURES WILL MOVE INTO SE TX FOR THE WEEKEND.
ISENTROPIC UPGLIDE SHOULD PERSIST INTO SATURDAY MORNING AS SW
WINDS ALOFT OVERRIDE N-NE SFC WINDS. PRECIP SHOULD END ON SAT AFTN
AS A STRONG UPPER LOW OVER BAJA RETROGRADES SLIGHTLY AND THIS WILL
ALLOW WEAK RIDGING TO AMPLIFY OVER DEEP SOUTH TEXAS. AS A
RESULT...UPPER LEVEL WINDS BRIEFLY BECOME WEST AND END THE
ISENTROPIC LIFT. IT WILL REMAIN UNSEASONABLY COLD THROUGH THROUGH
THE WEEKEND. THE UPPER LOW WILL BEGIN TO MOVE EAST ON MONDAY AND
SW WINDS ALOFT REDEVELOP. THE UPPER LOW WILL MOVE ACROSS THE STATE
NEXT TUES AND A COASTAL LOW WILL DEVELOP OFF CORPUS. THE TWO
FEATURES SHOULD BRING A GOOD CHANCE OF RAIN TO THE REGION NEXT
TUESDAY. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 77 53 71 54 74 / 10 10 10 10 10
HOUSTON (IAH) 78 54 71 56 74 / 20 10 10 10 20
GALVESTON (GLS) 78 62 69 63 74 / 30 10 10 10 20
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 9 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 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.
&&
$$
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1223 AM EST MON NOV 18 2013
.SYNOPSIS...
COLD FRONT WILL MOVE OVER THE AREA THROUGH THE NIGHT...AND EXIT
EAST BY MONDAY MORING. COLD HIGH PRESSURE SETTLES OVER THE GREAT
LAKES TUESDAY AND WEDNESDAY BRINGING DRIER WEATHER INTO THE MIDDLE
OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1055 PM EST SUNDAY...
COLD FRONT THIS EVENING LIES PITTSBURGH PA TO HUNTINGTON WV
SOUTHWEST TO NASHVILLE TN. RADAR SHOWING DISTINCT LINE OF
CONVECTION APPROACHING OUR SOUTHEAST WV COUNTIES BUT MARGINAL
INSTABILITY IN THIS AREA SHOULD KEEP THE WINDS AT JUST BELOW SVR
LEVELS...ALTHOUGH CANNOT RULE OUT AN ISOLATED TREE BEING BLOWN
DOWN ACROSS THE HIGHER ELEVATIONS OF WESTERN GREENBRIER. AS YOU
HEAD FURTHER EAST THE AIRMASS REMAINS WEDGED IN AND STABLE. THIS
WILL ACT TO KEEP THE HIGHER GUSTS ABOVE THE SURFACE...WITH SOME
HIGHER RIDGES ABOVE 3000-4000 FT GETTING SOME GUSTS TO 50 MPH.
WIND ADVISORY STILL LOOKS GOOD...SO NO CHANGES PLANNED HERE.
FOLLOWED THE 23Z HRRR AS WE HEAD THROUGH THE NIGHT WHICH INDICATES
THE LINE GRADUALLY LOSING ITS PUNCH AND ORGANIZATION ONCE IT GETS
TO ABOUT INSTERSTATE 81 AND THE BLUE RIDGE. WILL MAINTAIN A POP
CONFIGURATION OF LIKELY/CAT WITH THE LINE BUFFERED BY CHANCE
EITHER SIDE...THEN DRYING IT OUT FAST BY MORNING...AS STRONG WNW
AND SUBSIDENCE KICKS IN. TEMPS SEEM ON TARGET FOR LOWS...WHICH
WILL BE ELEVATED PER WIND AND CLOUDS.
PREVIOUS VALID DISCUSSION ISSUED AT 345 PM....
NOT MUCH DROP IN TEMPERATURES UNTIL THE FRONT GOES THROUGH THEN
ON MONDAY NOT MUCH RECOVERY OF TEMPERATURES WITH MODERATE COLD AIR
ADVECTION. STRONG ENOUGH PRESSURE RISES...IN THE +5 TO +10 MB/6HR
RANGE TO ENHANCE THE WINDS FOR MUCH OF THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 311 PM EST SUNDAY...
STILL A GRADIENT LEFT MONDAY NIGHT ALTHOUGH SURFACE HIGH PRESSURE IS
ON APPROACH. LEFTOVER WINDS COMBINED WITH SOME CLOUDS ACROSS SE WEST
VA WILL KEEP TEMPS A LITTLE WARMER THAN THEY WOULD BE IF THE CENTER
OF THE SURFACE HIGH WAS PARKED OVERHEAD. INTO TUESDAY
AFTERNOON...HIGH PRESSURE BEGINS A TRIP TOWARDS PENNSYLVANIA AND NEW
ENGLAND...EVENTUALLY IN THE QUINTESSENTIAL WEDGE POSITION FOR
WEDNESDAY. WITH DOWNSLOPING FLOW REMOVED...COLDER H85 VALUES AROUND
0C WILL COVER MOST OF THE CWA UNDER CLEAR SKIES TUESDAY. DEWPOINTS
MAY FALL INTO THE LOWER 20S AND UPPER TEENS SETTING THE STAGE FOR A
VERY COLD TUESDAY NIGHT...IF MID AND HIGH CLOUDS HOLD OFF FROM THE
SOUTH...AND DEVELOPING EASTERLY FLOW REMAINS WEAK. INCREASING
MID/HIGH CLOUDS WEDNESDAY...A VERY COLD START AND SUBTLE EASTERLY
BREEZES WITHIN THE WEDGE MAY KEEP MOST LOCATIONS BELOW 50F FOR
WEDNESDAY...WHICH IS BELOW THE MEX/ECMWF MOS NUMBERS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 340 PM EST SUNDAY...
A FEW CHANGES IN THE EXTENDED FORECAST BUT STILL LOOKS WET FRIDAY
NIGHT INTO SATURDAY EVENING. MODELS ARE ARGUING WHICH WEATHER
FEATURE WILL BRING RAIN TO THE AREA. THE 12Z GFS FAVORS A SHORT
COMING ACROSS THE TENN VALLEY AND OVER THE WEDGE THURSDAY NIGHT.
FRIDAY AND FRIDAY NIGHT...THE GFS HAS WAVES RIDING ALONG THE
FRONT..EVENTUALLY PUSHING THE COLD FRONT TO THE EAST COAST SATURDAY
MORNING. THE 12Z ECMWF HAS A COLD FRONT MOVING SLOWLY TO THE
EAST...FROM MISSISSIPPI VALLEY THURSDAY NIGHT...INTO THE OHIO VALLEY
FRIDAY AFTERNOON...THEN STALLS IT OVER THE MID ATLANTIC-SOUTHERN
APPALACHIAN MOUNTAINS SATURDAY MORNING. A SURFACE WAVE THEN DEVELOPS
ALONG THE FRONT...POSSIBLY OVER THE FORECAST AREA SATURDAY. THIS
WAVE WILL THEN TRACK NORTHEAST...PULLING THE FRONT ACROSS THE REGION
BY SATURDAY EVENING. SINCE THERE IS DISCONTINUITY BETWEEN MODELS AND
RUN-TO-RUN WITH EACH MODEL...WILL KEEP POPS IN A 20-40 PERCENT RANGE
FRIDAY AFTERNOON INTO SATURDAY AFTERNOON.
WITH EITHER MODEL AND/OR SCENARIO...THE GULF IS OPEN TO BRING THE
AREA MUCH NEEDED RAIN FRIDAY INTO SATURDAY. ALSO...MILD TO WARM
TEMPERATURES LIKELY FRIDAY...DEPENDING ON IF A LOCATION SEES RAIN.
ONCE THE FRONT MOVES TO THE COAST...85H TEMPERATURES DROP TO -10C.
&&
.AVIATION /05Z MONDAY THROUGH FRIDAY/...
AS OF 1215 AM EST MONDAY...
LINE OF SHOWERS WITH GUSTY WINDS WILL BE EAST OF BLF/LWB AT TAF
START TIME...REACHING BCB/ROA AT 06Z. RADAR INDICATES SOME HEAVIER
DOWNPOURS POSSIBLE AT BCB WITH GUSTS TO 30 KNOTS...AND HAVE A
TEMPO GROUP HERE. THE LATEST HIGH RES MODELS INDICATED THAT THE
LINE WEAKENS EAST OF THE BLUE RIDGE SO LYH/DAN IS EXPECTED TO SEE
SOME SHOWERS BUT OVERALL NO HEAVY RAIN ISSUES. UNTIL THE FRONT
PASSES...LOOKING AT BELOW 3KFT CIGS AND AS LOW AS 1KFT ALONG THE
RIDGES...BUT KEPT IT ABOVE FOR NOW. WINDS SHIFT FROM SOUTHWEST TO
WEST-NORTHWEST AT BLF/LWB 07-08Z...BCB/ROA 08-09Z...AND LYH/DAN
10-11Z.
ONCE THE FRONT MOVES BY CIGS RISE TO VFR AND SCATTER OUT. LOOK FOR
VFR TO PERSIST THROUGH THE DAY MONDAY. WIND STAYS GUSTY THROUGH
THE DAY SUBSIDING FOR SOME AROUND DUSK.
WINDS WILL BE GUSTY TOMORROW FROM THE WNW WITH SOME REACHING 30
KNOTS...MAINLY AT THE AIRPORTS LIKE KGEV/KHSP.
DRY HIGH PRESSURE WILL SUPPORT VFR CONDITIONS THROUGH TUESDAY
AFTERNOON...BEFORE WEDGING AGAINST THE EASTERN FACE OF THE
APPALACHIANS. MAY SEE A RETURN OF STRATUS THURSDAY MORNING AS THE
NORTHEAST FLOW WORKS ATLANTIC MOISTURE TOWARD THE BLUE RIDGE.
&&
.FIRE WEATHER...
AS OF 350 PM EST SUNDAY...
REGION STAYS IN MOIST AIR MASS TONIGHT IN ADVANCE OF A STRONG
COLD FRONT. THE PROBABILITY OF A WETTING RAIN RISES SHARPLY BY
THIS EVENING. WINDS FROM THE SOUTH AND SOUTHWEST INCREASE LATER
OVERNIGHT....ESPECIALLY AT HIGHER ELEVATIONS AHEAD OF THE FRONT.
ONCE THE FRONT COMES THROUGH EARLY MONDAY MORNING...WIND WILL SHIFT
TO THE WEST AND NORTHWEST. GUSTY WINDS ARE EXPECTED MONDAY AND
MONDAY NIGHT. BY THE TIME RELATIVE HUMIDITIES DROP BACK DOWN TO
AROUND 30 PERCENT ON TUESDAY...WIND SPEEDS WILL BE DIMINISHING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR VAZ007-019-
020-024-035.
NC...NONE.
WV...WIND ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR WVZ042-043-
045.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...AMS/WP
SHORT TERM...KM
LONG TERM...RCS
AVIATION...AMS/WP
FIRE WEATHER...AMS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1108 PM EST SUN NOV 17 2013
.SYNOPSIS...
COLD FRONT WILL MOVE OVER THE AREA THROUGH THE NIGHT...AND EXIT
EAST BY MONDAY MORING. COLD HIGH PRESSURE SETTLES OVER THE GREAT
LAKES TUESDAY AND WEDNESDAY BRINGING DRIER WEATHER INTO THE MIDDLE
OF NEXT WEEK.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 1055 PM EST SUNDAY...
COLD FRONT THIS EVENING LIES PITTSBURGH PA TO HUNTINGTON WV
SOUTHWEST TO NASHVILLE TN. RADAR SHOWING DISTINCT LINE OF
CONVECTION APPROACHING OUR SOUTHEAST WV COUNTIES BUT MARGINAL
INSTABILITY IN THIS AREA SHOULD KEEP THE WINDS AT JUST BELOW SVR
LEVELS...ALTHOUGH CANNOT RULE OUT AN ISOLATED TREE BEING BLOWN
DOWN ACROSS THE HIGHER ELEVATIONS OF WESTERN GREENBRIER. AS YOU
HEAD FURTHER EAST THE AIRMASS REMAINS WEDGED IN AND STABLE. THIS
WILL ACT TO KEEP THE HIGHER GUSTS ABOVE THE SURFACE...WITH SOME
HIGHER RIDGES ABOVE 3000-4000 FT GETTING SOME GUSTS TO 50 MPH.
WIND ADVISORY STILL LOOKS GOOD...SO NO CHANGES PLANNED HERE.
FOLLOWED THE 23Z HRRR AS WE HEAD THROUGH THE NIGHT WHICH INDICATES
THE LINE GRADUALLY LOSING ITS PUNCH AND ORGANIZATION ONCE IT GETS
TO ABOUT INSTERSTATE 81 AND THE BLUE RIDGE. WILL MAINTAIN A POP
CONFIGURATION OF LIKELY/CAT WITH THE LINE BUFFERED BY CHANCE
EITHER SIDE...THEN DRYING IT OUT FAST BY MORNING...AS STRONG WNW
AND SUBSIDENCE KICKS IN. TEMPS SEEM ON TARGET FOR LOWS...WHICH
WILL BE ELEVATED PER WIND AND CLOUDS.
PREVIOUS VALID DISCUSSION ISSUED AT 345 PM....
NOT MUCH DROP IN TEMPERATURES UNTIL THE FRONT GOES THROUGH THEN
ON MONDAY NOT MUCH RECOVERY OF TEMPERATURES WITH MODERATE COLD AIR
ADVECTION. STRONG ENOUGH PRESSURE RISES...IN THE +5 TO +10 MB/6HR
RANGE TO ENHANCE THE WINDS FOR MUCH OF THE DAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY NIGHT/...
AS OF 311 PM EST SUNDAY...
STILL A GRADIENT LEFT MONDAY NIGHT ALTHOUGH SURFACE HIGH PRESSURE IS
ON APPROACH. LEFTOVER WINDS COMBINED WITH SOME CLOUDS ACROSS SE WEST
VA WILL KEEP TEMPS A LITTLE WARMER THAN THEY WOULD BE IF THE CENTER
OF THE SURFACE HIGH WAS PARKED OVERHEAD. INTO TUESDAY
AFTERNOON...HIGH PRESSURE BEGINS A TRIP TOWARDS PENNSYLVANIA AND NEW
ENGLAND...EVENTUALLY IN THE QUINTESSENTIAL WEDGE POSITION FOR
WEDNESDAY. WITH DOWNSLOPING FLOW REMOVED...COLDER H85 VALUES AROUND
0C WILL COVER MOST OF THE CWA UNDER CLEAR SKIES TUESDAY. DEWPOINTS
MAY FALL INTO THE LOWER 20S AND UPPER TEENS SETTING THE STAGE FOR A
VERY COLD TUESDAY NIGHT...IF MID AND HIGH CLOUDS HOLD OFF FROM THE
SOUTH...AND DEVELOPING EASTERLY FLOW REMAINS WEAK. INCREASING
MID/HIGH CLOUDS WEDNESDAY...A VERY COLD START AND SUBTLE EASTERLY
BREEZES WITHIN THE WEDGE MAY KEEP MOST LOCATIONS BELOW 50F FOR
WEDNESDAY...WHICH IS BELOW THE MEX/ECMWF MOS NUMBERS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 340 PM EST SUNDAY...
A FEW CHANGES IN THE EXTENDED FORECAST BUT STILL LOOKS WET FRIDAY
NIGHT INTO SATURDAY EVENING. MODELS ARE ARGUING WHICH WEATHER
FEATURE WILL BRING RAIN TO THE AREA. THE 12Z GFS FAVORS A SHORT
COMING ACROSS THE TENN VALLEY AND OVER THE WEDGE THURSDAY NIGHT.
FRIDAY AND FRIDAY NIGHT...THE GFS HAS WAVES RIDING ALONG THE
FRONT..EVENTUALLY PUSHING THE COLD FRONT TO THE EAST COAST SATURDAY
MORNING. THE 12Z ECMWF HAS A COLD FRONT MOVING SLOWLY TO THE
EAST...FROM MISSISSIPPI VALLEY THURSDAY NIGHT...INTO THE OHIO VALLEY
FRIDAY AFTERNOON...THEN STALLS IT OVER THE MID ATLANTIC-SOUTHERN
APPALACHIAN MOUNTAINS SATURDAY MORNING. A SURFACE WAVE THEN DEVELOPS
ALONG THE FRONT...POSSIBLY OVER THE FORECAST AREA SATURDAY. THIS
WAVE WILL THEN TRACK NORTHEAST...PULLING THE FRONT ACROSS THE REGION
BY SATURDAY EVENING. SINCE THERE IS DISCONTINUITY BETWEEN MODELS AND
RUN-TO-RUN WITH EACH MODEL...WILL KEEP POPS IN A 20-40 PERCENT RANGE
FRIDAY AFTERNOON INTO SATURDAY AFTERNOON.
WITH EITHER MODEL AND/OR SCENARIO...THE GULF IS OPEN TO BRING THE
AREA MUCH NEEDED RAIN FRIDAY INTO SATURDAY. ALSO...MILD TO WARM
TEMPERATURES LIKELY FRIDAY...DEPENDING ON IF A LOCATION SEES RAIN.
ONCE THE FRONT MOVES TO THE COAST...85H TEMPERATURES DROP TO -10C.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
AS OF 635 PM EST SUNDAY...
SIGNIFICANT CHANGES WILL BE OCCURRING DURING THE TAF PERIOD.
WEDGE STILL HOLDING DOWN CIGS/VSBYS ACROSS THE FOOTHILLS/PIEDMONT.
MOST AREAS WILL BE SEEING OFF AND ON -SHRA WITH AT TIMES MODERATE
SHOWERS THIS EVENING AHEAD OF THE FRONT. IN THE WEST THERE SHOULD
BE SOME LOWERING OF CIGS AS MORE SHOWERS MOVE IN...SO THE VFR
THERE SHOULD BE SHORT LIVED.
THINK PREVIOUS FORECAST HAD THINGS WELL IN HAND WITH TIMING OF THE
FRONT AND THE WIND SHIFT FROM SOUTH TO SOUTHWEST TO WEST. LOOK FOR
BLF/LWB TO GET THE MAIN THRUST OF THE FRONT AROUND 06-08Z...WITH
WINDS GUSTING WITH THE BAND OF SHOWERS. THE GUSTY WINDS WITH THE
SHOWERS WILL MAKE IT INTO BCB/ROA BY 08Z...AND OUT EAST TOWARD
MORNING...ALTHOUGH SOME THINKING THAT THE STRENGTH WILL BE
LESSENED AS CORE OF LOW LVL JET WORKS NORTH OF THE AREA.
SO OVERALL KEEPING TAFS IN THE MVFR OR WORSE RANGE UNTIL OR
SHORTLY AFTER FROPA...THEN SHOULD CLEAR OUT AT LEAST EAST OF THE
BLF/LWB SECTIONS BY 12-14Z...WHILE UPSLOPE BKN VFR CIGS LINGER AT
BLF/LWB UNTIL 14-18Z.
WINDS WILL BE GUSTY TOMORROW FROM THE WNW WITH SOME REACHING 30
KNOTS...MAINLY AT THE AIRPORTS LIKE KGEV/KHSP.
DRY HIGH PRESSURE WILL SUPPORT VFR CONDITIONS THROUGH TUESDAY
AFTERNOON...BEFORE WEDGING AGAINST THE EASTERN FACE OF THE
APPALACHIANS. MAY SEE A RETURN OF STRATUS THURSDAY MORNING AS THE
NORTHEAST FLOW WORKS ATLANTIC MOISTURE TOWARD THE BLUE RIDGE.
&&
.FIRE WEATHER...
AS OF 350 PM EST SUNDAY...
REGION STAYS IN MOIST AIR MASS TONIGHT IN ADVANCE OF A STRONG
COLD FRONT. THE PROBABILITY OF A WETTING RAIN RISES SHARPLY BY
THIS EVENING. WINDS FROM THE SOUTH AND SOUTHWEST INCREASE LATER
OVERNIGHT....ESPECIALLY AT HIGHER ELEVATIONS AHEAD OF THE FRONT.
ONCE THE FRONT COMES THROUGH EARLY MONDAY MORNING...WIND WILL SHIFT
TO THE WEST AND NORTHWEST. GUSTY WINDS ARE EXPECTED MONDAY AND
MONDAY NIGHT. BY THE TIME RELATIVE HUMIDITIES DROP BACK DOWN TO
AROUND 30 PERCENT ON TUESDAY...WIND SPEEDS WILL BE DIMINISHING.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY UNTIL 6 AM EST MONDAY FOR VAZ007-019-020-024-035.
NC...NONE.
WV...WIND ADVISORY UNTIL 6 AM EST MONDAY FOR WVZ042-043-045.
&&
$$
SYNOPSIS...AMS/WP
NEAR TERM...AMS/WP
SHORT TERM...KM
LONG TERM...RCS
AVIATION...AMS/WP
FIRE WEATHER...AMS
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1108 PM MST TUE NOV 19 2013
.SHORT TERM...(TONIGHT THROUGH WEDNESDAY NIGHT)
ISSUED AT 310 PM MST TUE NOV 19 2013
MOIST LOW AMPLITUDE SHORT WAVE RACES ACROSS NORTHWEST COLORADO
TONIGHT. RADAR SHOWING LOW DBZ RETURNS AS THE MOISTURE INCREASES
THIS AFTERNOON...SOME OF THIS PCPN IS REACHING THE GROUND AS KCAG
MEASURED A TRACE AND SUNLIGHT MOUNTAIN AWOS REPORTS LIGHT SNOW.
THE COMBINATION OF OROGRAPHICS AND WEAK DYNAMICAL FORCING WILL
RESULT IN WIDESPREAD LIGHT PCPN OVERNIGHT ACROSS NW COLORADO...POSSIBLY
EXTENDING AS FAR SOUTH AS THE ELK MOUNTAINS. ENHANCED CLOUD COVER
IN THE INFRARED IS SOMEWHAT FRAGMENTED AND UPSTREAM RADAR
OBSERVATIONS SHOW BROKEN AREAS OF PCPN. THE RAP MODEL SHOW PCPN
EXPANDING AS THE SHORT WAVE GETS LIFTED OVER THE DIVIDE...BUT
APPEARS THAT THE TIME DURATION DOES NOT LAST LONG ENOUGH FOR
ADVISORY CRITERIA SNOWFALL. APPEARS THE ELKHEADS AND PARK RANGE
MAY GET A FEW INCHES OF SNOW TONIGHT...BUT TAPERING OFF AFTER
MIDNIGHT. THE SRN HALF HALF GETS EXTENSIVE CLOUD COVER BUT THE
MOISTURE IS NOT AS DEEP...FLURRIES OR BRIEF LIGHT SNOW MAY OCCUR
OVER THE SAN JUAN MOUNTAINS AS THE SHORT WAVE DRAGS ACROSS WRN
COLORADO.
SATELLITE INFRARED AND WATER VAPOR CLEARLY SHOWS A STREAM OF
MOISTURE FROM NW OF THE HAWAIIAN ISLES TO THE CALIFORNIA COAST.
THE FORECAST AREA MAY GET ONLY ONE SHOT AT THIS MOISTURE AND THAT
OCCURS FROM WEDNESDAY AFTERNOON INTO THURSDAY. BUT SHORT WAVE
ENERGY ADVECTING THIS MOISTURE TO THE FOUR CORNERS REGION IS WEAK
AND FRAGMENTED (SIMILAR TO THE LEAD SHORT WAVE). NO SHORTAGE OF
MOISTURE AS 700 MB SPECIFIC HUMIDITY VALUES EXCEED 4 G/KG...BUT
OTHER FEATURES THAT ARE NEEDED FOR EFFICIENT RAIN OR SNOW PRODUCTION
ARE MISSING. LACKING ELEMENTS INCLUDE BAROCLINICITY AND
DYNAMICAL/OROGRAPHICAL FORCING AS 700 MB GRADIENT FLOW IS LESS
THAN 20 KNOTS. THE AREA OF PRECIPITATION WILL BE EXPANDING
WEDNESDAY AFTERNOON OVER SW COLORADO AND SPREADING NEWD...CURRENT
QPF PROJECTIONS SUGGEST SNOW POTENTIAL OF 4 TO 8 INCHES OVER THE
SAN JUAN AND WRN COLORADO CENTRAL MOUNTAINS. THE DEEPEST MOISTURE
WILL BE POSITIONED ACROSS THE REGION ON WEDNESDAY NIGHT BEFORE
SHIFTING DOWNSTREAM BY THURSDAY MORNING...NOT COINCIDING WITH THE
COLD FRONT SURGING SOUTHWARD NEAR THE WYOMING BORDER. SNOW LEVELS
A BIT TRICKY AND WILL BE FLUCTUATING DEPENDING ON TIME OF DAY. IN
GENERAL TERMS...SNOW LEVELS WILL RANGE FROM 7000 TO 8000 FEET.
DIABATIC COOLING PROCESSES COULD RESULT IN WET SNOW TO NEAR THE
VALLEY FLOORS LATE WEDNESDAY NIGHT. LATER SHIFTS MAY NEED TO
CONSIDER HOISTING WINTER WEATHER ADVISORIES.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 310 PM MST TUE NOV 19 2013
BY THU THE SPLIT IN THE FLOW WILL BECOME MORE DISTINCT AS THE LOW
BEGINS TO CLOSE OFF ROUGHLY OVER SOUTHERN CALIFORNIA. A MOIST AND
UNSETTLED SOUTHWEST FLOW AHEAD OF THE LOW WILL CONTINUE TO STREAM
OVER THE SOUTHWEST CORNER OF THE CONUS...AND ACROSS THE SOUTHERN
AND CENTRAL ROCKIES. IN ADDITION...A COLD FRONT ASSOCIATED WITH A
NORTHERN BRANCH SHORTWAVE WILL DROP INTO THE NORTHERN EDGE OF THE
CWA BY AROUND MIDDAY. WE CAN EXPECT MOUNTAIN SNOW AND THE CHANCE
FOR VALLEY RAIN TO CONTINUE THROUGH THU. MOST OF THE AREA WILL BE
DOMINATED BY THE MOIST UNSTABLE SOUTHWEST FLOW WITH SOUTH-
SOUTHWEST SLOPES FAVORED IN THIS REGIME. BUT THE OROGRAPHICS WILL
GENERALLY REMAIN ON THE WEAK SIDE AS THE SOUTHWEST FLOW IS NOT
EXPECTED TO BE OVERLY STRONG. OVER THE FAR NORTH HOWEVER...THE
AREA IMPACTED BY THE THE NORTHERN BRANCH COLD FRONT WILL SPREAD
SOUTH/SOUTHEAST. I EXPECT THAT THERE WILL BE A NICE ENHANCEMENT OF
THE PRECIPITATION IN THE VICINITY OF THE FRONT. BUT MODELS
INDICATE MUCH DRIER AIR WILL PUSH IN BEHIND THE FRONT. THIS WILL
BRING A DOWNTURN IN POPS OVER THE NORTHWEST CORNER BY LATE IN THE
AFTERNOON WITH THAT TREND EXTENDING SOUTH-SOUTHWEST THROUGH THE
EVENING. ALSO A LOCALIZED AREA OF STRONG NORTHERLY WINDS WILL
DEVELOP OVER WESTERN MOFFAT COUNTY INTO THE EASTERN UINTA BASIN
DURING THE EVENING. MUCH COLDER TEMPS WILL RESULT IN THIS DRIER
AIR BEHIND THE FRONT. MODELS DISAGREE ON JUST HOW FAR SOUTH THIS
FRONT WILL REACH BEFORE IT WASHES OUT IN THE SOUTHWEST FLOW AHEAD
OF THE SOUTHERN BRANCH LOW. BUT WE CAN CERTAINLY EXPECT MUCH
COLDER TEMPS OVER THE FAR NORTH...WITH LESS COOLING AS ONE TRAVELS
SOUTH.
MODELS AGREE THAT THE LOW WILL STALL IN THE VICINITY OF SAN DIEGO
BY EARLY FRIDAY...THEN PRETTY MUCH REMAIN STATIONARY UNTIL EARLY
SUNDAY. BY SUN AFTERNOON THE LOW BEGINS TO SLOWLY SHIFT
EAST...MAKING IT OVER NM/GFS...TO THE OK PANHANDLE/ECMWF ON
MONDAY. THIS KEEPS THE DESERT SOUTHWEST THROUGH THE SOUTHERN CO
MOUNTAINS UNDER A MOIST UNSETTLED FLOW AHEAD OF THIS LOW...AND
STILL UNSETTLED AS IT PASSES. OVER THE NORTH...MODELS SHOW A COL
AREA BETWEEN THE SOUTHERN BRANCH LOW AND THE NORTHERN BRANCH
NORTHWESTERLIES WILL MORE OR LESS SET UP OVER WY/NORTHERN CO...AND
EXTEND INTO NORTHEAST UT. THIS WILL KEEP THE NORTHERN HALF TO
TWO/THIRDS OF THE CWA ON THE DRY SIDE. BUT OUR SOUTHERN EDGE MAY
CONTINUE TO SEE PRECIPITATION TROUGH MONDAY. EXPECT THERE WILL BE
BREAKS AT TIMES. AND AS ANY EMBEDDED DISTURBANCES MOVE INTO THE
THE AREA... SHOWERS WILL BE ENHANCED.
MODELS ALL AGREE THAT BY TUE...A DRIER NORTH-NORTHWEST FLOW WILL
DOMINATE AREA-WIDE AS A LARGE AREA OF HIGH PRESSURE BUILDS TO OUR
WEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1030 PM MST TUE NOV 19 2013
VFR EXPECTED IN MOST PLACES BUT THERE WILL BE AN AREA OF MVFR
SOUTH OF EEO BUT NORTH OF MTJ DUE TO SHOWERS MOVING THROUGH.
MOUNTAIN AREAS MAY BE PARTLY OBSCURED TONIGHT FROM LOW CEILINGS. SNOW
LEVELS WILL BE LOWERING TO NEAR THE VALLEY FLOORS OR AROUND 5500
FEET.
VFR ALL TAF SITES AFTER 12Z UNTIL ABOUT 00Z THURS WHEN DEEP MOISTURE
RETURNS ESPECIALLY IN SOUTHERN LOCATIONS...VISIBILITIES AND
CEILING REDUCING AT HIGHER LOCATIONS IN THE SAN JUANS THROUGHOUT
THE EVENING.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...NONE.
UT...NONE.
&&
$$
SHORT TERM...PF
LONG TERM...EH
AVIATION...JAM
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
442 AM EST WED NOV 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EST WED NOV 20 2013
UPPER MICHIGAN IS BETWEEN SURFACE FEATURES THIS MORNING...WITH A
1036MB HIGH MOVING EAST FROM THE LOWER GREAT LAKES AND A 996MB LOW
BETWEEN LAKE WINNIPEG AND HUDSON BAY. A COLD FRONT STRETCHES
SOUTHWEST FROM THIS LOW THROUGH NORTHWEST MINNESOTA AND THROUGH THE
DAKOTAS. THE PRESSURE GRADIENT BETWEEN THESE THREE FEATURES HAS
LEAD TO BREEZY CONDITIONS EARLY THIS MORNING...ESPECIALLY OVER LAKE
SUPERIOR AND THE DOWNSLOPE AREAS OF CENTRAL UPPER MICHIGAN. KMQT VAD
WIND DATA SHOWS 45KT WINDS AT 2KFT AND THAT MATCHES UP WELL WITH
THE 46KT GUST RECORDED AT STANNARD ROCK LAST HOUR. THE REST OF
THE UPPER MICHIGAN HAS BEEN GUSTING TO 15-30KTS OVER THE LAST
COUPLE OF HOURS. EXPECT THE GUSTY WINDS TO CONTINUE THROUGH A GOOD
PORTION OF THE DAY TODAY AT VALUES SIMILAR TO WHAT WAS SEEN
OVERNIGHT. WITH A LITTLE BETTER MIXING...THE HIGHER GUSTS WILL
LIKELY BE MORE WIDESPREAD THAN THE SPORADIC VALUES SEEN OVERNIGHT.
FORTUNATELY...THE 40-50KT 925MB WINDS SHOULD STAY ABOVE THE SURFACE
DUE TO THE INVERSION INDICATED JUST BELOW THAT LEVEL. WITH THE
GRADIENT WEAKENING OVER THE AREA FROM WEST TO EAST THIS AFTERNOON
AND EVENING...ALONG THE WITH PRESSURE FALLS NORTH OF LAKE SUPERIOR
EXITING THIS MORNING...EXPECT A DIMINISHING TREND IN THE WINDS THIS
AFTERNOON/EVENING.
THE REST OF THE WEATHER FORECAST WILL DEPEND ON TWO FEATURES...THE
COLD FRONT TO THE WEST OF THE AREA THAT WILL MOVE THROUGH TONIGHT
AND THURSDAY AND A SHORTWAVE CURRENTLY PULLING OUT OF COLORADO.
THIS SHORTWAVE WILL SLIDE NORTHEAST TODAY AND ACROSS UPPER MICHIGAN
THIS EVENING AND EARLY OVERNIGHT HOURS. AS THIS OCCURS...THE COLD
FRONT WILL BE MOVING ACROSS WESTERN LAKE SUPERIOR. MID LEVEL
SOUTHWESTERLY FLOW AHEAD OF THIS WAVE HAS PRODUCED WIDESPREAD MID
CLOUDS FROM THE CENTRAL PLAINS INTO ONTARIO AND EXPECT THAT TO
CONTINUE THROUGH MUCH OF THE DAY TODAY. RADAR HAS BLOSSOMED OVER THE
LAST COUPLE OF HOURS FROM LAKE SUPERIOR THROUGH EASTERN IOWA AND ALL
ASSOCIATED WITH THE MID CLOUDS. THUS...THERE IS PROBABLY SOME PRECIP
FALLING OUT OF THOSE CLOUDS...BUT THE DRIER AIR IS EVAPORATING THE
PRECIP BEFORE REACHING THE SURFACE (NO OBS INDICATING RAIN). MODELS
INDICATING THERE COULD BE A FEW SHOWERS OVER CENTRAL LAKE SUPERIOR
AND THE KEWEENAW TODAY...BUT HAVE MAINLY LEFT AS SLIGHT CHANCES
SINCE THE DRIER LOW LEVELS WILL LIKELY EVAPORATE MUCH OF THE PRECIP.
THERE WAS A BRIEF PERIOD OF 2-3KFT RETURNS JUST NORTHEAST OF
MARQUETTE (WHICH HAD BEEN HINTED AT IN THE ECMWF AND A COUPLE OTHER
MODELS OVER THE LAST COUPLE OF DAYS)...BUT IT QUICKLY DISSIPATED.
THE DRY AIR INDICATED OVER THE AREA ON INITIAL RAP SOUNDINGS
(DEWPOINT DEPRESSIONS OF 15-20C BETWEEN 900-800MB) WILL CONTINUE
THROUGH MUCH OF THE DAY AND WILL PLAY A ROLE IN THE PRECIP TYPE
FORECAST FOR LATE THIS AFTERNOON AND TONIGHT.
MODELS SEEM TO HAVE DECENT AGREEMENT WITH THE PRECIPITATION TIMING
AND LOCATION FOR TONIGHT...AS THE LOWER LEVELS MOISTEN FROM TOP DOWN
WITH THE ARRIVAL OF THE SHORTWAVE. BEST FORCING FROM THE
SHORTWAVE...ALONG WITH 700-500 Q-VECTOR CONVERGENCE AND ISENTROPIC
ASCENT ON 280-290K SFCS TRACKS ACROSS THE MUCH OF THE CWA...WITH THE
GREATEST FOCUS OVER THE CENTRAL AND EAST THIS EVENING. THINK THAT
LAYER IS WHERE MUCH OF THE PRECIPITATION WILL INITIATE LATE THIS
AFTERNOON OVER NORTHERN WISCONSIN AND THEN LIFT NORTHEAST INTO UPPER
MICHIGAN. LOOKING UPSTREAM...THERE IS NOT MUCH FOR LOWER LEVEL
MOISTURE...AND THINK THAT IT WILL TAKE A LITTLE BIT FOR THE
PRECIPITATION TO COOL AND MOISTEN THE LOWER LEVELS. THIS CAN
SOMEWHAT BE SEEN ON MODEL QPF FIELDS WITH THEIR BLOTCHY NATURE AT
TIMES ALONG WITH 280-285K THETA-E SURFACES COND PRESS DEF VALUES
INDICATING SIGNIFICANT LIFT NEEDED TO MOISTEN THE CENTRAL/EASTERN
CWA DURING THE LATE AFTERNOON/EVENING. IN ADDITION...THE HIGHER
RESOLUTION RUNS ARE ALSO SHOWING SOME OF THE DOWNSLOPE FLOW OVER THE
NORTH CENTRAL EATING AWAY AT QPF AMOUNTS. THEREFORE...ALTHOUGH THE
CONFIDENCE IS HIGH ON TIMING/LOCATION...QPF AMOUNTS ARE MORE
UNCERTAIN DUE TO THE DRY AIR AND WILL LIKELY COME DOWN TO HOW
QUICKLY THINGS MOISTEN. THINK WE WILL GET PRECIPITATION...BUT
WONDERING IF THE DRY AIR WILL LOWER QPF AMOUNTS MORE THAN SOME OF
THE MODELS ARE INDICATING. ALSO...THERE ARE SOME HINTS ON THE 06Z
MODEL RUNS THAT THE MAIN PIECE OF SHORTWAVE ENERGY (NOTED BY THE PV
ANOMALY) WILL SLIDE SOUTH OF THE AREA (THROUGH CENTRAL WISCONSIN
AND LOWER MICHIGAN). AS THE SHORTWAVE SLIDES EAST OVERNIGHT...HAVE
DIMINISHED POPS FROM SOUTHWEST TO NORTHEAST.
AS FOR PRECIP TYPE...HAVE FOLLOWED THE WETBULB0 VALUES FOR MUCH OF
THE FORECAST...AS IT HANDLES WHERE THE THERMAL FIELDS WILL GO AS
EVAPORATIVE COOLING AND MOISTENING OCCURS. THIS LEADS TO MUCH OF
THE INTERIOR (HIGHER TERRAIN) WEST/CENTRAL TO QUICKLY TRANSITION TO
OR START AS SNOW. WITH THE UNCERTAINTY ON QPF...HAVE WENT WITH A
MIDDLE GROUND OF 0.1-0.18IN OF QPF OVER THE CENTRAL CWA WITH
LOWER AMOUNTS WEST AND EAST. WITH THAT AREA SHOWING MAINLY
SNOW...WOULD EXPECT AROUND AN INCH OF ACCUMULATION DURING THE
EVENING HOURS. OF COURSE...IF THE HIGHER QPF SHOWN IN THE 00Z
NAM/GFS IS CORRECT...COULD SEE AMOUNTS AROUND OR A LITTLE OVER 2
INCHES AROUND IRON/DICKINSON COUNTY BUT NOT COMPLETELY BUYING THEIR
QUICK 0.2-0.3IN OF QPF LATE THIS AFTERNOON. DID CONTINUE RAIN/SNOW
IN THE DOWNSLOPE WARMED AREAS NEAR LAKE SUPERIOR AND ALSO OVER THE
EAST. AS DEEPER MOISTURE PULLS OUT OF THE WEST OVERNIGHT...MUCH OF
THE REMAINING CLOUD ENDS UP BEING WARMER THAN -5C. THUS...IF ANY
PRECIPITATION DOES OCCUR...WOULD EXPECT IT TO BE AS FREEZING
DRIZZLE. PREVIOUS SHIFT HAD A GOOD HANDLE ON THIS IDEA AND HAVE
ONLY MADE MINOR ADJUSTMENTS TO PUSH IT A LITTLE TO THE WEST.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 435 PM EST TUE NOV 19 2013
A SOMEWHAT ACTIVE AND MESSY START TO THE LONG TERM WILL BE FOLLOWED
BY THE COLDEST AIRMASS OF THE SEASON. A SERIES OF WEAK WAVES ARE
EXPECTED TO BRING PRECIP CHANCES WEDNESDAY NIGHT...AND POSSIBLY
AGAIN THURSDAY NIGHT INTO FRIDAY. ARCTIC AIR WILL THEN USHER IN FOR
THE WEEKEND...BRINGING BLUSTERY CONDITIONS FOR SATURDAY AND A PERIOD
OF LAKE EFFECT SNOW FOR N TO NW WINDS BELTS.
WEDNESDAY NIGHT AND THURSDAY...A BROAD MID-LEVEL TROUGH ACROSS
CENTRAL CANADA WILL BE IMPINGING ON A DEPARTING SHARP MID-LEVEL
RIDGE ACROSS THE NE CONUS AND ST LAWRENCE VALLEY. AN ASSOCIATED SFC
LOW OVER SOUTHERN HUDSON BAY WILL EXTEND SOUTHWESTWARD ACROSS THE
UPPER MS VALLEY TO A DEVELOPING LOW OVER THE SW STATES. THE FIRST OF
A SERIES OF SHORTWAVE TROUGHS WILL ROUND THE BASE OF THE BROAD
CANADIAN TROUGH BEGINNING WEDNESDAY NIGHT. MODELS ARE IN FAIRLY GOOD
AGREEMENT THAT A WEAK SFC LOW WILL DEVELOP ALONG THE TROUGH OVER
WESTERN LAKE SUPERIOR WEDNESDAY NIGHT.
PRECIP ON WAA AHEAD OF THE DEVELOPING LOW WILL BE ONGOING ACROSS THE
CENTRAL CWA AT THE START OF THE PERIOD. MUCH OF THIS PRECIP WILL BE
FORCED BY WEAK ISENTROPIC LIFT ON THE 285K TO 295K SFCS AND WEAK
MID-LEVEL Q-VECTOR CONVERGENCE AHEAD OF THE SHORTWAVE. DID NOT
CHANGE MUCH IN THE GENERAL PRECIP COVERAGE OTHER THAN SLOW THE
EASTWARD PROGRESSION BY A FEW HOURS. THE MAIN QUESTION REVOLVES
AROUND PRECIP TYPE. WITH RATHER DRY AIR BELOW 5KFT...WETBULB ZERO
HEIGHTS WILL BE UNDER 1KFT FOR NEARLY THE ENTIRE CWA...KEEPING
PRECIP ALL SNOW. AS NOTED BY THE PREVIOUS SHIFT...DOWNSLOPE
INFLUENCE AND SLIGHTLY HIGHER WETBULB ZERO HEIGHTS/TEMPS SHOULD KEEP
PRECIP RAIN TO A MIX OF RAIN/SNOW ALONG LAKE SUPERIOR. VERY POOR
SNOW GROWTH WILL KEEP RATIOS QUITE LOW. WITH THAT...AND WITH OVERALL
WEAK FORCING...ONLY EXPECT UP TO AN INCH OF SNOW INTERIOR WEST.
THE ASSOCIATED COLD FRONT WILL PUSH ACROSS THE CWA FROM WEST TO EAST
THURSDAY. CAA ACROSS THE WEST WILL KEEP TEMPS STEADY IN THE MORNING
BEFORE DROPPING DURING THE AFTERNOON. THE EAST MAY SEE A TOUCH OF
CLEARING AHEAD OF THE FRONT...SO TWEAKED TEMPS UP A DEGREE OR SO FOR
THURSDAY. DRY AIR WORKING IN AND LOWERING INVERSION AT AND BEHIND
THE FRONT MAY RESULT IN SOME PATCHY FREEZING DRIZZLE FOR SOME
LOCATIONS ACROSS THE WEST HALF WED NIGHT INTO THURSDAY MORNING. ONLY
PUT A SLIGHT MENTION IN ATTM...BUT FELT CONDITIONS WARRANTED SOME
PLACEMENT OF FZDZ IN THE FORECAST. EXPECT AN OVERALL BREAK IN
PRECIP...BUT NOT CLOUDS...THURSDAY AS COLD AIR CONTINUES TO FILTER
INTO THE AREA AND SUBSIDENCE INCREASES BEHIND THE TROUGH.
THURSDAY NIGHT AND FRIDAY...THE FORECAST BECOMES QUITE CHALLENGING
AT THIS POINT AS MODEL SPREAD AND RUN-TO-RUN CONSISTENCY BECOMING
QUITE POOR. AGREEMENT IS DECENT...HOWEVER...THAT A REINFORCING
SHORTWAVE TROUGH DIGGING OUT OF WESTERN CANADA WILL TRACK ACROSS THE
BASE OF THE BROAD CANADIAN TROUGH. THE GFS HAS BEEN PERSISTENT FOR
OVER A DAY NOW WITH DEVELOPING A STRONG SFC LOW OVER LOWER MI INTO
FAR EASTERN ONTARIO ON FRIDAY. THE ECMWF...NAM...AND GEM WERE ALL IN
AGREEMENT THAT A WEAKER LOW WOULD REMAIN SOUTH OF THE REGION.
HOWEVER...THE 12Z ECMWF HAS TRENDED NORTHWARD AND STRONGER WITH THE
SYSTEM...THUS INTRODUCING MORE MODEL SPREAD. HAVE TRENDED NORTHWARD
WITH CHANCE POPS A SLIGHT BIT ACROSS THE SOUTH CENTRAL AND EASTERN
CWA...BUT DO NOT WANT TO JUMP ON THE ECMWF TREND QUITE YET. IF THE
ECMWF DOES COME IN LINE WITH THE GFS...A BREEZY FRIDAY WITH LIGHT TO
MODERATE LAKE ENHANCED SNOW COULD OCCUR. FOR NOW...HAVE MAINTAINED A
MOSTLY DRY FORECAST FOR FRIDAY WITH GENERALLY LIGHT WINDS.
SATURDAY THROUGH TUESDAY...GUIDANCE COMES A BIT MORE IN LINE ONCE
THE LOW PASSES SATURDAY. A POTENT ARCTIC FRONT WITH A POCKET OF H8
AIR LESS THAN -20C WILL ADVECT CROSS THE CWA WITH A VERY STRONG
1050MB SFC BUILDING IN BEHIND THE FRONT...RESULTING IN LES AND
STRONG NORTHWESTERLY WINDS. LOCATIONS EXPOSED TO NW WINDS ALONG LAKE
SUPERIOR COULD SEE GUSTS OVER 40MPH ON SATURDAY. COMBINED WITH THE
COLDER TEMPS ONLY IN THE UPPER TEENS...WIND CHILLS WILL FALL TO
AROUND 0F...IF NOT A BIT LOWER FOR SATURDAY. OVERALL...IT WILL BE A
TRUE UPPER MICHIGAN WINTER DAY. DRY AIR SHOULD CUT OFF REMAINING LES
ON SUNDAY.
DEEP TROUGHING WILL CONTINUE ACROSS EASTERN CANADA INTO EARLY NEXT
WEEK WITH SIGNS OF A CLIPPER SYSTEM TRACKING ACROSS THE CWA ON
MONDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1212 AM EST WED NOV 20 2013
EXPECT VFR CONDITIONS OVERNIGHT THROUGH WED MORNING AS THE LOW-LEVEL
AIR MASS REMAINS DRY. A TIGHT PRES GRADIENT BTWN STRENGTHENING
HIGH PRES TO THE E AND LOW PRES MOVING TOWARD HUDSON BAY WILL BRING
STRONG SOUTHERLY FLOW TO THE AREA TONIGHT. WITH SFC WINDS LARGELY
DECOUPLED DUE TO INVERSION... LLWS IS EXPECTED EXCEPT FOR AT IWD
WHERE DECOUPLING IS NOT STRONG ENOUGH TO KEEP WINDS FROM GUSTING TO
NEAR 30KT. WAA PCPN MOVING IN MID TO LATE AFTERNOON WILL DROP CIGS
TO AROUND MVFR WITH VSBY REMAINING MAINLY VFR. PCPN TYPE MAY START
OUT BRIEFLY AS RAIN AND THEN CHANGE TO SNOW TOWARD 00Z/THU. PCPN
CHANGING TO SNOW DURING THE EVENING WILL DROP CONDITIONS TOWARD THE
LOWER END MVFR WITH EVEN IFR CIGS POSSIBLE BY LATE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 441 AM EST WED NOV 20 2013
SOUTHERLY GALES TO 35-40KTS WILL CONTINUE THROUGH MOST OF THE
DAYLIGHT HOURS TODAY OVER EASTERN LAKE SUPERIOR AHEAD OF
A COLD FRONT MOVING THROUGH MINNESOTA TODAY. TIMING OF THE ONGOING
GALE WARNING LOOKS GOOD AND WON/T MAKE ANY CHANGES AT THIS TIME. AS
THE FRONT NEARS LATE THIS AFTERNOON AND EVENING...EXPECT THE WINDS
TO DIMINISH FROM WEST TO EAST THROUGH THE NIGHT. THE FRONT WILL
SLOWLY MOVE EAST ACROSS LAKE SUPERIOR TONIGHT AND THURSDAY...WHICH
WILL SHIFT THE WINDS TO THE NORTHWEST 20-30KTS ON THURSDAY. A HIGH
PRESSURE RIDGE MOVING OVER THE LAKE ON THURSDAY NIGHT WILL SHIFT
WINDS TO THE NORTH AND DIMINISH THEM THURSDAY NIGHT THROUGH FRIDAY.
A WEAK LOW TRACKING FROM THE SOUTHERN PLAINS THROUGH THE LOWER GREAT
LAKES ON FRIDAY WILL KEEP THE NORTHERLY WINDS IN PLACE DUE TO A WEAK
TROUGH SETTING UP OVER UPPER MICHIGAN. THIS TROUGH WILL DIVE SOUTH
ON FRIDAY NIGHT AND WHEN COMBINED WITH A STRONG HIGH BUILDING INTO
THE NORTHERN PLAINS...EXPECT NORTHWESTERLY WINDS TO INCREASE TO
GALES TO 35-40KTS ON SATURDAY AND CONTINUE INTO SATURDAY NIGHT. THIS
EVENT WILL BE SHORT LIVED...AS A RIDGE FROM THAT STRONG HIGH SHIFTS
EAST OVER THE UPPER GREAT LAKES ON SUNDAY AND BRINGS WINDS BELOW
25KTS BY SUNDAY AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LSZ244-245-266-
267.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ264.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ249>251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...KLUBER
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
304 AM CST Wed Nov 20 2013
.SHORT TERM...(Today and Tonight)
Issued at 304 AM CST WED NOV 20 2013
Currently...as expected, isentropic upglide is underway in the
300-310K layer with a solid pressure advection signal. Regional
radar has seen a gradual increase in showers and even a few
lightning strikes. MUCAPE according to the short range models is
in the 100-200 J/kg range (slightly higher to the west over KS/OK)
and supports at least a slight chance mention for thunder for the
remainder of this morning.
Could see varying precip types this morning given the very dry low
levels. The 00z soundings from KSGF/KLZK/KSHV all show a very
stout low level dry layer. RUC initializations from 07z still
indicating dewpoint depressions around 900mb in the 30-50 C range!
With a southeast downsloping wind, dewpoints are struggling at the
surface, dropping into the teens in many locations, especially
northwest of the plateau and ahead of the incoming radar echoes.
Precip falling from these echoes is likely falling as (mainly)
rain, but cannot rule out some poor man`s sleet mixing in given a
6000 foot layer of wet bulb temperatures aloft at or just below 0C.
With a little bit of elevated instability, cannot argue with very
small hail with any storms.
The short wave responsible for instigating this activity will move
from the central Plains and toward the Great Lakes region through
the day. The area will remain in the left exit region of an upper
jet most of the morning, so there will be broad scale lift
support. In the mid to lower levels, isentropic upglide/pressure
advection will continue in the 300-310K layer this morning,
shunting to the northeast into northern Missouri during the
afternoon hours. Will maintain scattered to numerous shower
wording this morning with a mention of sleet possibly mixing in
from time to time through the mid morning hours. During the
afternoon, have lowered PoPs a bit and changed to chance wording
as most of the shower activity should be exiting into central and
northern Missouri.
There will likely be a brief lull in the rainfall from late this
afternoon into the early evening. However, the next shortwave will
be ready to move into the region during the overnight hours. Have
ramped up PoPs during the overnight hours as showers and a few
embedded thunderstorms should envelope the area from southwest to
northeast.
Temperatures will be a challenge today given wet bulbing,
scattered showers and cloud cover. Have held close to a consensus
of the MOS and raw models, which keep readings mainly in the 50-55
degree range (slightly warmer across far southwestern MO).
.LONG TERM...(Thursday through Tuesday)
Issued at 304 AM CST WED NOV 20 2013
Periods of rain are expected on Thursday across the entire outlook
area. NAM/GFS continue to suffer from convective feedback, though
it is indicative of locally heavy rainfall potential. This heavier
rainfall will likely occur in a narrow, mesoscale band, almost
impossible to pin point. Yet another shortwave will move into the
region later Thursday night into early Friday resulting in yet
more periods of rainfall. By Thursday night, model consensus
indicates that a cold front and shallow low level cold airmass
will begin moving into the region, spreading across the entire
area Friday morning. At this point, thermal profiles from all
models support a wet forecast, rather than wintry. We will have
to keep a very sharp eye on this airmass intrusion, especially
across the northwest third of the CWA.
Some good news is that the global models continue to indicate a
progressive invasion of colder and drier air for Friday night.
Have lowered PoPs a bit more and if present trends continue,
Friday night may only feature a few lingering light rain showers
or flurries. Storm total rainfall accumulation for this event
continues to suggest a widespread 0.50" to 2.00" with a mesoscale
band of locally higher amounts possible.
The weekend will be cold and mostly dry as a 1050mb surface high
pressure settles down from southern Canada into the Midwest
region. The center of the high will be near the Missouri Ozarks
area Saturday night into Sunday morning. This will be the coldest
night with clear skies and light winds...temperatures will be
likely in the middle to upper teens. High temperatures this
weekend will be only in the 30s despite sunshine.
The next big question will be what does the cut off low over the
southwest U.S. do for the early part of next week and how much
cold air will be around when this system moves out into the
southern Plains region.
The latest runs of the GFS..ECMWF...GEM...indicate this system
will affect the area by Monday morning. There is still some
disagreement on track and timing but the consensus is that precip
may begin to develop late Sunday night into Monday morning and
spread into the area. It does appear at this time that light
wintry weather mainly in the form of light snow will be possible.
The ECMWF and GEM are the most bullish with the QPF. With
temperatures not climbing much on Monday...there will be a
rain/snow mix possible and lingering through Monday night. Will
need to monitor future trends with model data but the Monday
morning commute could be tricky with light snow in the area but
amounts appear light at this time up to an inch possible. Below
average temperatures will continue through middle of next week
with another surge of cold air moving in.
&&
.AVIATION...(For the 06Z TAFS through 06Z Wednesday Night)
Issued at 1129 PM CST TUE NOV 19 2013
Pilots can expect VFR ceilings to blanket the region tonight and
Wednesday while gusty southerly winds continue.
Scattered showers will develop overnight and continue into
Wednesday morning but the visibility will be predominately VFR.
Surface winds will gusts to over 20 kts at the Joplin and
Springfield terminals through Wednesday. Low level wind shear will
impact the terminal sites through Wednesday morning and will
return Wednesday night.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Gagan
LONG TERM...Gagan/Griffin
AVIATION...Foster
AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
1022 PM MST Tue Nov 19 2013
update aviation section
.DISCUSSION...
Update forthcoming. Strong cold front continues to push south across
the area this evening. The front has moved to the Little Belt
mountains and has moved through Lewistown. Radar returns indicate
snow continuing to develop over the western mountains and push east
across the plains. The winter weather highlight for the Northern
Rocky Mountain Front will continue. Winds behind the front have gone
northerly and the upslope flow will help generate areas of light
snow. The latest RUC analysis shows the snow becoming more
widespread after midnight and sagging south. The snow will increase
over the mountains of Beaverhead, Madison, and Gallatin counties and
the winter weather highlight for this area will continue. Snow
amounts over the plains continue to look on the light side with
generally 1 to 2 inches expected. Have adjusted the hourly
temperatures to better align with reality. Emanuel
&&
.AVIATION...
UPDATED 0522Z.
A cold front continues to push through the forecast area from the
north. While it has made it through north central Montana...it is
presently hung up over the Little Belts. Over the nighttime...the
cold airmass will deepen...eventually making its way to the Helena
valley around 1200Z. Lower clouds behind the front will cause
MVFR/IFR conditions along with some snow. As the front continues
through the CWA, expect low clouds and light snow most areas tonight
and gradually diminishing from the northwest during the morning
daylight hours on Wednesday. db
&&
.PREV DISCUSSION...Issued 303 PM MST Tue Nov 19 2013
Cold Canadian airmass continues to slowly expand south into north
central MT, with leading edge as far south as Heart Butte,
Choteau, Power and Ft Benton to the Bears Paw Mtns. Expect the
front the continue south through the remainder of north central MT
through the remainder of this afternoon and evening, bringing an
abrupt drop in temperatures to the Great Falls area by 5pm and
Lewistown by 9pm. In the upper levels a broad trough will push
east into northern Rockies tonight and across MT tomorrow while an
upper level jet maximum moves east along the Canadian border.
Gusty winds will continue across most of the forecast area tonight
with some potential for strong winds along the continental
divide and Rocky Mtn Front from MacDonald Pass north through
Augusta until the front passes this evening. expect light snow
showers to develop over much of north central MT tonight as cold
air deepens and northerly upslope winds spread south into central
MT. Snow accumulations look to be around an inch or less on the
plains with slightly higher amounts near the little Belts. As the
frontal boundary sags south into SW MT late tonight and the upper
level trough and jet maximum move over the region, snow will
increase over the mtns of Gallatin/Madison and Beaverhead county
with 4 to 6 inches of accumulation likely at elevations above 6000
ft, manly south of I90. temperatures will cool into the single
digits and low teens over north central MT tonight with the cold
airmass deepening over the entire forecast area on Wednesday with
temperatures about 15-25 degrees below seasonal averages. coldest
temperatures of the period look to occur Wednesday night as cold
airmass remains in place with clearing skies and light winds
allowing temperatures to fall into the single digits or colder at
many locations. An upper level ridge moves into the region
Thursday for dry conditions and moderating temperatures. Hoenisch
Thursday Night through Tuesday...Mainly dry, northwest flow will
persist through the period with little precipitation chances. A weak
surface cold front will reinforce the cold, Canadian airmass as it
backs into eastern portions of the forecast area. Despite the
limited moisture, weak convergence and upslope should support a few
snow showers so have kept a slight chance of precipitation across
north-central Montana for Friday. As a ridge of high pressure builds
over the West Coast this weekend, northwest flow aloft will persist
with little chance of precipitation through early next week.
Temperatures will moderate to seasonal averages by Saturday and then
above seasonal averages through early next week. Southwest surface
winds will be breezy at times throughout the forecast period, but
periods of high winds are not anticipated. Long-range models beyond
the forecast period are hinting at a possible weather system for the
middle to end of next week, which is during the Thanksgiving holiday
travel period. Forecast confidence is very low due to uncertainty in
the models, but continue to monitor the forecast for updates
throughout the week. MLV
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 8 17 3 28 / 60 40 0 0
CTB -2 13 0 30 / 60 30 0 0
HLN 24 28 8 29 / 40 50 0 0
BZN 28 35 6 28 / 40 70 10 0
WEY 25 32 3 18 / 80 80 30 10
DLN 29 38 11 30 / 30 50 10 0
HVR 5 15 -1 25 / 60 40 0 0
LWT 12 16 1 28 / 60 60 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 11 PM this evening to 5 PM MST
Wednesday FOR ELEVATIONS ABOVE 6000 FEET FOR Beaverhead...
Gallatin...Madison.
WINTER WEATHER ADVISORY until 5 AM MST Wednesday FOR ELEVATIONS
ABOVE 5000 FEET FOR Northern Rocky Mountain Front.
&&
$$
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AREA FORECAST DISCUSSION
NWS GREAT FALLS MT
900 PM MST Tue Nov 19 2013
.DISCUSSION...
Update forthcoming. Strong cold front continues to push south across
the area this evening. The front has moved to the Little Belt
mountains and has moved through Lewistown. Radar returns indicate
snow continuing to develop over the western mountains and push east
across the plains. The winter weather highlight for the Northern
Rocky Mountain Front will continue. Winds behind the front have gone
northerly and the upslope flow will help generate areas of light
snow. The latest RUC analysis shows the snow becoming more
widespread after midnight and sagging south. The snow will increase
over the mountains of Beaverhead, Madison, and Gallatin counties and
the winter weather highlight for this area will continue. Snow
amounts over the plains continue to look on the light side with
generally 1 to 2 inches expected. Have adjusted the hourly
temperatures to better align with reality. Emanuel
&&
.AVIATION...
UPDATED 2330Z.
A cold front pushing through the forecast area from north to south
had made it to Great Falls by 2330Z. Lower clouds behind the front
will cause MVFR/IFR conditions along with some snow. As the front
continues through the CWA, expect low clouds and light snow most
areas tonight and gradually diminishing from the northwest during
the morning daylight hours on Wednesday. db
&&
.PREV DISCUSSION...Issued 303 PM MST Tue Nov 19 2013
Cold Canadian airmass continues to slowly expand south into north
central MT, with leading edge as far south as Heart Butte,
Choteau, Power and Ft Benton to the Bears Paw Mtns. Expect the
front the continue south through the remainder of north central MT
through the remainder of this afternoon and evening, bringing an
abrupt drop in temperatures to the Great Falls area by 5pm and
Lewistown by 9pm. In the upper levels a broad trough will push
east into northern Rockies tonight and across MT tomorrow while an
upper level jet maximum moves east along the Canadian border.
Gusty winds will continue across most of the forecast area tonight
with some potential for strong winds along the continental
divide and Rocky Mtn Front from MacDonald Pass north through
Augusta until the front passes this evening. expect light snow
showers to develop over much of north central MT tonight as cold
air deepens and northerly upslope winds spread south into central
MT. Snow accumulations look to be around an inch or less on the
plains with slightly higher amounts near the little Belts. As the
frontal boundary sags south into SW MT late tonight and the upper
level trough and jet maximum move over the region, snow will
increase over the mtns of Gallatin/Madison and Beaverhead county
with 4 to 6 inches of accumulation likely at elevations above 6000
ft, manly south of I90. temperatures will cool into the single
digits and low teens over north central MT tonight with the cold
airmass deepening over the entire forecast area on Wednesday with
temperatures about 15-25 degrees below seasonal averages. coldest
temperatures of the period look to occur Wednesday night as cold
airmass remains in place with clearing skies and light winds
allowing temperatures to fall into the single digits or colder at
many locations. An upper level ridge moves into the region
Thursday for dry conditions and moderating temperatures. Hoenisch
Thursday Night through Tuesday...Mainly dry, northwest flow will
persist through the period with little precipitation chances. A weak
surface cold front will reinforce the cold, Canadian airmass as it
backs into eastern portions of the forecast area. Despite the
limited moisture, weak convergence and upslope should support a few
snow showers so have kept a slight chance of precipitation across
north-central Montana for Friday. As a ridge of high pressure builds
over the West Coast this weekend, northwest flow aloft will persist
with little chance of precipitation through early next week.
Temperatures will moderate to seasonal averages by Saturday and then
above seasonal averages through early next week. Southwest surface
winds will be breezy at times throughout the forecast period, but
periods of high winds are not anticipated. Long-range models beyond
the forecast period are hinting at a possible weather system for the
middle to end of next week, which is during the Thanksgiving holiday
travel period. Forecast confidence is very low due to uncertainty in
the models, but continue to monitor the forecast for updates
throughout the week. MLV
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 8 17 3 28 / 60 40 0 0
CTB -2 13 0 30 / 60 30 0 0
HLN 24 28 8 29 / 40 50 0 0
BZN 28 35 6 28 / 40 70 10 0
WEY 25 32 3 18 / 80 80 30 10
DLN 29 38 11 30 / 30 50 10 0
HVR 5 15 -1 25 / 60 40 0 0
LWT 12 16 1 28 / 60 60 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY from 11 PM this evening to 5 PM MST
Wednesday FOR ELEVATIONS ABOVE 6000 FEET FOR Beaverhead...
Gallatin...Madison.
WINTER WEATHER ADVISORY until 5 AM MST Wednesday FOR ELEVATIONS
ABOVE 5000 FEET FOR Northern Rocky Mountain Front.
&&
$$
weather.gov/greatfalls
www.twitter.com/NWSGreatFalls
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AREA FORECAST DISCUSSION...UPDATED
NWS ABERDEEN SD
1130 PM CST TUE NOV 19 2013
.UPDATE...
SEE UPDATED AVIATION DISCUSSION BELOW.
&&
.PREVIOUS DISCUSSION...
.SHORT TERM...TONIGHT THROUGH THURSDAY NIGHT
QUITE A CHANGE COMING IN THE SHORT TERM FROM THIS AFTERNOON
THROUGH THURSDAY NIGHT. FOR TONIGHT...EXPECT RR QUAD JET INDUCED
HIGH CLOUDS TO MOVE ON THIS EVENING WHILE MORE HIGH CLOUDS SPREAD
IN FROM THE WEST. BREEZY SOUTH WINDS WILL DECREASE THIS EVENING
WITH WINDS BECOMING NORTHWEST THROUGH NORTH BY MORNING AS A WEAK
SURFACE LOW PRESSURE TROUGH MOVES THROUGH. TEMPERATURES WILL NOT
FALL OFF MUCH TONIGHT WITH THE MILD AIR MASS REMAINING. LOWS ARE
EXPECTED TO RANGE FROM AROUND 30 DEGREES NORTH CENTRAL TO THE MID
TO UPPER 30S IN THE WATERTOWN/ORTONVILLE AREA. OTHERWISE...HIGHS
ON WEDNESDAY WILL LIKELY BE IN THE MORNING AS AN ARCTIC BOUNDARY
PUSHES IN DURING THE AFTERNOON WITH NORTH WINDS PICKING UP AND
TEMPERATURES FALLING ACROSS THE NORTH. EXPECT WINDS TO BECOME
BLUSTERY AT 15 TO 30 MPH WITH HIGHER GUSTS. THE OTHER ISSUE WILL
BE THE LIGHT SNOW DEVELOPING ALONG AND BEHIND THE SURFACE COLD
FRONT. MID LEVEL FRONTOGENESIS ALONG WITH SOME JET STREAK HELP
WILL BRING LIGHT SNOW TO NORTH CENTRAL SOUTH DAKOTA BY LATE
AFTERNOON. THE MODELS INDICATE LESSER AMOUNTS OF LIFT AND QPF AS
THIS REGION DESCENDS SOUTH ACROSS OUR CWA THROUGH WEDNESDAY NIGHT.
THUS...HAVE LIKELY CHANCES EARLY DIMINISHING THROUGH THE NIGHT.
SNOWFALL AMOUNTS SHOULD BE GENERALLY BELOW AN INCH BY THURSDAY
MORNING. ARCTIC AIR ENCOMPASSES THE ENTIRE CWA ON THURSDAY WITH
LESS WIND. MUCH BELOW NORMAL TEMPERATURES ARE EXPECTED ON
THURSDAY WITH HIGHS IN THE 20 TO 25 DEGREE RANGE ACROSS THE CWA.
THE MODELS THEN SHOW AN UPPER LEVEL LOW PRESSURE TROUGH AND THE
ASSOCIATED LIFT SWINGING OVER THE REGION THURSDAY AND THURSDAY
EVENING. WITH MUCH OF THE NORTHERN CWA UNDER LOW LEVEL DRY
AIR...EXPECT THE BEST CHANCES OF LIGHT SNOW WITH THIS SYSTEM TO
BE FROM PIR TO HURON TO ATY. EXPECT MORE CLOUD COVER AND LIGHT
SNOW TO SPREAD QUICKLY WEST TO EAST ON THURSDAY ACROSS MAINLY THE
SOUTHERN CWA. COULD HAVE SOME MORE SNOWFALL ACCUMULATIONS OF AN INCH
OR TWO. THE LIGHT SNOW WILL END QUICKLY THURSDAY NIGHT WITH
CLEARING SKIES IN BEHIND AND SINGLE DIGIT LOWS.
.LONG TERM...FRIDAY THROUGH TUESDAY
NORTHWEST FLOW ALOFT WILL DOMINATE THE LONG TERM PORTION OF THE
FORECAST. A SURFACE LOW PRESSURE SYSTEM PASSING ACROSS THE GREAT
LAKES REGION ON FRIDAY WILL ALLOW FOR BITTER ARCTIC COLD
TEMPERATURES TO FILTER INTO THE AREA BY FRIDAY NIGHT. BY 12Z
SATURDAY TEMPERATURES AT H85 RANGE IN THE MID TO UPPER TEENS BELOW
ZERO...WHICH IS APPROACHING TWO STANDARD DEVIATIONS BELOW NORMAL. LOW
TEMPERATURES SHOULD EASILY DROP TO THE SINGLE DIGITS ON EITHER
SIDE OF ZERO BY SATURDAY MORNING. THE SURFACE HIGH PRESSURE WILL
EXIT THE REGION ON SATURDAY NIGHT ALLOWING FOR WAA TO SPREAD INTO
THE CWA. TEMPERATURES THROUGH THE REST OF THE PERIOD WILL BE
AROUND NORMAL...DUE TO EXPECTED SNOW COVER. NO SIGNIFICANT
PRECIPITATION CHANCES ARE EXPECTED FOR THE PERIOD.
&&
.AVIATION...
06Z TAFS FOR THE KABR...KATY...KPIR AND KMBG TERMINALS
VFR CONDITIONS ARE EXPECTED THROUGH WEDNESDAY AFTERNOON. KATY
WILL REMAIN BREEZY OVERNIGHT. A LOW WILL BEGIN TO IMPACT
THE REGION LATE WED AFTERNOON. CIGS WILL BEGIN TO LOWER NEAR
KPIR/KMBG WED EVENING WITH LIGHT SNOW MOVING INTO THE WESTERN CWA
BY THE END OF THE TAF PERIOD. WINDS WILL SHIFT TO THE NORTH AND
NORTHWEST BEGINNING LATE WEDNESDAY MORNING AND BECOME GUSTY.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
&&
$$
UPDATE...WISE
SHORT TERM...MOHR
LONG TERM...SD
AVIATION...WISE
WEATHER.GOV/ABERDEEN
AREA FORECAST DISCUSSION
NWS MIAMI FL
939 AM EST WED NOV 20 2013
.UPDATE...
MAJOR CHANGES HAVE NOT BEEN MADE TO THE MORNING UPDATE. THERE
APPEARS TO BE A WEAK SURFACE TROUGH OFF THE EAST COAST WHICH IS
TRIGGERING CONVECTION OVER THE ATLANTIC WATERS BUT THE MAIN
SURFACE BOUNDARY IS STILL NORTH OF LAKE OKEECHOBEE. THE 12Z MFL
SOUNDING DOES SHOW SOME MODEST INSTABILITY WITH WEAK MID LEVEL
LAPSE RATES WITHIN THE WARM SECTOR ALONG WITH WELL ABOVE AVERAGE
PWAT FOR MID NOVEMBER. HOWEVER, THE LAST TWO RUNS OF THE HRRR HAVE
DECREASED THE AMOUNT OF AFTERNOON CONVECTION ACROSS THE PENINSULA AND
IF THIS TREND CONTINUES, WILL NEED TO SCALE BACK AT LEAST ON THE
TIMING OF THE HIGHER POPS.
KOB
&&
.PREV DISCUSSION... /ISSUED 552 AM EST WED NOV 20 2013/
AVIATION...
A STATIONARY FRONT WILL SLOWLY DISSIPATE THROUGH THURSDAY OVER
SOUTH CENTRAL FLORIDA. THIS WILL KEEP LOW LEVEL MOISTURE IN PLACE
OVER THE SOUTH FLORIDA TAF SITES TODAY INTO THURSDAY ALONG WITH
SCATTERED SHOWERS. THERE COULD EVEN BE A THUNDERSTORM OVER THE TAF
SITES THIS AFTERNOON...BUT THE COVERAGE WILL BE FEW AND FAR
BETWEEN. SO AT THIS TIME WILL CONTINUE TO CARRY VCSH IN THE TAF
SITES FOR TODAY.
THE CEILING AND VIS WILL REMAIN IN THE VFR CONDITIONS TODAY OVER
THE TAF SITES. HOWEVER...KTMB AND KAPF TAF SITES COULD SEE VIS
REDUCTION INTO THE MVFR CONDITIONS EARLY THIS MORNING AND AGAIN
LATE TONIGHT INTO EARLY THURSDAY MORNING DUE TO FOG FORMATION.
AVIATION...54/BNB
PREV DISCUSSION... /ISSUED 423 AM EST WED NOV 20 2013/
SHORT TERM (TODAY-FRIDAY)...
PLENTY OF DEEP LAYER MOISTURE COMBINED WITH A FRONTAL BOUNDARY
STALLING NEAR/OVER THE AREA WILL KEEP THE RAIN CHANCES UP THROUGH A
GOOD PORTION OF THE SHORT-TERM PERIOD. MODEL SOUNDINGS REFLECT THIS
MOIST ENVIRONMENT AND SHOW PRECIPITABLE WATER VALUES RANGING FROM
1.6-1.9" THROUGH THE PERIOD...WHICH IS ABOVE AVERAGE FOR THIS TIME
OF YEAR. THE EARLY MORNING SURFACE ANALYSIS SHOWED THE FRONTAL
BOUNDARY JUST NORTH OF OUR LOCAL AREA WITH A WEAK PRE-FRONTAL TROUGH
EXTENDING SOUTHWEST OUT AHEAD OF IT. THE LATEST WATER VAPOR LOOP
SHOWED MOSTLY ZONAL FLOW ACROSS THE REGION. A FEW RIPPLES OF ENERGY
TRANSLATING EWD WITHIN THE WESTERLY FLOW ALOFT COULD SLIGHTLY
ENHANCE THE RAINFALL ACTIVITY ALONG AND AHEAD OF THE BOUNDARY
PERIODICALLY OVER THE UPCOMING 24-48 HRS. UPPER HEIGHTS WILL THEN
BEGIN TO RISE THROUGH THE LATTER HALF OF THE PERIOD...WHICH MAY
INTRODUCE SOME SLIGHTLY DRIER CONDITIONS AND REDUCE THE TSTM CHANCES
BY FRIDAY. THE FLOW WILL REMAIN QUITE WEAK THROUGH THE LOWER
LEVELS...WHICH SHOULD ALLOW THE EAST/WEST COAST SEA BREEZES TO
DEVELOP THROUGH THE AFTERNOON HOURS. TEMPERATURES WILL REMAIN
SEVERAL DEGREES ABOVE AVERAGE WITH OVERNIGHT LOWS RANGING FROM THE
MID 60S INLAND TO THE LOWER 70S ALONG THE EAST COAST/METRO LOCATIONS
EACH NIGHT. AFTERNOON HIGHS ARE FORECAST TO REACH THE LOW TO MID 80S
EACH DAY. THIS COMBINED WITH DEWPOINTS REMAINING IN THE UPPER 60S
WILL KEEP THE HUMID CONDITIONS IN PLACE.
LONG TERM (SATURDAY-WEDNESDAY)...
THE LATEST GFS MEAN/GFS/ECMWF REMAIN IN DECENT AGREEMENT THROUGH THE
WEEKEND AND INDICATE UPPER HEIGHTS FALLING AS A STRONG SHORTWAVE
TROUGH DIGS SOUTHEAST DRIVING A COLD FRONT THROUGH THE LOCAL AREA
THROUGH THE DAY SUNDAY. THUNDERSTORM CHANCES WITH THIS BOUNDARY
SHOULD REMAIN LOW AS MOST OF THE UPPER FORCING REMAINS WELL TO THE
NORTH. THIS BOUNDARY WILL BE FOLLOWED BY GUSTY NNE WINDS SUNDAY
NIGHT INTO MONDAY WITH SOME DRIER/SLIGHTLY COOLER AIR SPREADING OVER
THE AREA. HOWEVER...TEMPERATURES ARE NOT EXPECTED TO CHANGE MUCH
WITH THIS BOUNDARY AS THE FLOW IF FORECAST TO QUICKLY VEER TO THE
ESE AHEAD OF ANOTHER DEVELOPING SYSTEM ALONG THE TEXAS COAST IN
RESPONSE TO A STRONG SHORTWAVE TROUGH. THIS FEATURE IS PROGGED TO
QUICKLY SWEEP FROM WEST TO EAST ALONG THE NORTHERN GULF COAST STATES
MONDAY THROUGH TUESDAY DRAGGING A SECOND COLD FRONT THROUGH THE AREA
BY THE END OF THE EXTENDED PERIOD.
AVIATION...
PATCHY FOG WILL REMAIN POSSIBLE THROUGH DAYBREAK...MAINLY
FOR TMB AND APF...WHICH MAY PERIODICALLY RESTRICT VSBY/CIGS. ANY
FOG SHOULD BURN OFF QUICKLY AFTER 13/14Z. LIGHT WINDS WILL PERSIST
THROUGH MUCH OF THE PERIOD AS A FRONTAL BOUNDARY REMAINS NEAR/OVER
THE LOCAL AREA. LIGHT WESTERLY WINDS ASSOCIATED WITH THE AFTERNOON
SEA BREEZE WILL REMAIN POSSIBLE AT APF TODAY. THE BEST CHANCE FOR
SHOWERS AND STORMS WILL REMAIN ALONG THE EAST COAST THROUGH THE
PERIOD AS PLENTY OF MOISTURE REMAINS IN PLACE. FOG WILL BECOME A
POSSIBILITY ONCE AGAIN LATE TONIGHT INTO THURSDAY MORNING...MAINLY
FOR TMB AND APF.
BNB/AG
MARINE...
LIGHT WINDS WILL REMAIN IN PLACE ACROSS THE LOCAL WATERS THROUGH
FRIDAY AS A FRONTAL BOUNDARY STALLS OVER THE AREA. THE BEST CHANCE
FOR SHOWERS AND STORMS WILL REMAIN ALONG THE ATLANTIC COAST THROUGH
THURSDAY. A SMALL NORTHERLY SWELL ASSOCIATED WITH FRESH TO STRONG
NORTHEAST WINDS NORTH OF THE FRONT WILL CONTINUE TO SPREAD SOUTH
OVER THE ATLANTIC WATERS THROUGH THE REMAINDER OF THE WEEK. A
STRONG COLD FRONT WILL PUSH THROUGH THE AREA BY THE END OF THE
WEEKEND WITH STRONG NORTHEAST WINDS AND BUILDING SEAS EXPECTED
SUNDAY NIGHT THROUGH MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 83 73 83 72 / 50 40 50 20
FORT LAUDERDALE 83 74 83 74 / 50 30 50 10
MIAMI 84 72 83 73 / 50 20 50 10
NAPLES 84 68 85 69 / 20 20 20 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
955 AM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 951 AM CST WED NOV 20 2013
BASED ON REPORTS OF SLEET IN THE KIIB AREA...THE FORECAST HAS BEEN
UPDATED TO ADD MENTION OF SLEET IN THE FAR NORTHWEST PART OF THE
AREA.
THE SLEET APPEARS TO BE THE RESULT OF EVAPORATIVE COOLING WITH
SURFACE DEW POINTS BELOW 30 DEGREES. BASED ON RAP TRENDS...THE
LOWEST PART OF THE ATMOSPHERE WILL SLOWLY SATURATE THE REMAINDER
OF THE MORNING AND SHOULD PUSH THE PRECIPITATION OVER TO ALL
RAIN. ANY SLEET ACCUMULATIONS ARE EXPECTED TO BE MINOR WITH AMOUNTS
BRIEFLY BEING NO MORE THAN 0.1 OR 0.2 INCHES.
UPDATE ISSUED AT 904 AM CST WED NOV 20 2013
ADJUSTMENTS HAVE BEEN MADE TO THE FORECAST TO BETTER REFLECT
PRECIPITATION TRENDS ON RADAR AND THE OVERALL TIMING AS IT
MOVES/DEVELOPS NORTHEAST. KIIB CURRENTLY SHOWS SNOW BUT A WEB CAM
IS INCONCLUSIVE ON PRECIPITATION TYPE. IT IS POSSIBLE THAT A BRIEF
MIX MAY OCCUR IN THE FAR NORTHWEST UNTIL THE ATMOSPHERE SATURATES
BUT NO ACCUMULATION IS EXPECTED DUE TO THE STILL WARM GROUND.
&&
.SYNOPSIS...
ISSUED AT 250 AM CST WED NOV 20 2013
A WEAK SHORT WAVE RIDGE AND SURFACE HIGH PRESSURE ARE SLIDING EAST
OF THE AREA WHILE A MODEST STORM SYSTEM PULLS OUT OF THE ROCKIES
INTO THE CENTRAL AND NORTHERN PLAINS. MOISTURE AHEAD OF THIS
SYSTEM IS APPARENT VIA ECHOS ON THE 88D...BUT OTHER THAN A FEW
SPOTS OF SLEET...MOST OF THE RETURNS ARE ALOFT. MORE SUBSTANTIAL
PRECIP IN NORTHWEST MISSOURI IS ASSOCIATED WITH THUNDER DUE TO SUPPORT
FROM THE LOW-LEVEL JET.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CST WED NOV 20 2013
MAIN CONCERN IN THE SHORT TERM IS THE IMPACT OF THE TROUGH AS IT
PASSES ACROSS THE AREA TODAY AND THIS EVENING.
SHORT AND LONG TERM MODELS ARE IN GOOD AGREEMENT IN MOVING PRECIP
INTO THE CWA DURING THE MORNING...THEN OUT OF THE CWA DURING THE
EVENING. QPFS ARE FAIRLY CONSISTENT BETWEEN 1/5 AND 1/3 INCH...NOT
SUFFICIENT TO HAVE A NOTABLE IMPACT IN AREAS WHERE DROUGHT
PERSISTS. THE GFS QPF IS AN OUTLIER AND SEEMS TOO WET WHICH MAY
RELATE TO A LARGE AREA OF SEVERELY OVER ANALYZED AND FORECAST
SURFACE DEW POINTS IN THE SOUTH CENTRAL U.S. ON THE 00Z INITIAL.
CLOUDS ARE INCREASING AND WITH RAIN DEVELOPING...TEMPS WILL
STRUGGLE TO CLIMB TODAY. LOOKS LIKE GUIDANCE CAUGHT UP TO THE COOL
VALUES WE HAVE BEEN FORECASTING...SO MADE NO SIGNIFICANT CHANGE TO
MAX TEMPS. AS THE SYSTEM DEPARTS THE AREA...LOW-LEVEL FLOW
BECOMES WEAK AS AN INVERTED TROUGH DEVELOPS. MOISTURE HANGS IN SO
CLOUDS WILL PERSIST AHEAD OF THE NEXT SYSTEM IN LINE...WHICH
SHOULD HOLD UP MIN TEMPS TONIGHT. WOLF
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 250 AM CST WED NOV 20 2013
THE MAIN FORECAST CONCERN CONTINUE TO BE PRECIPITATION TYPE THURSDAY
NIGHT INTO FRIDAY AND TEMPERATURES AFTER SATURDAY. MODELS ARE IN
DECENT OVERALL AGREEMENT THROUGH THE PERIOD WITH SOME TIMING
DIFFERENCES WITH THE ARCTIC AIR FOR THIS WEEKEND.
A WAVE WILL RIDE ALONG A STRONG BAROCLINIC ZONE THAT SETS UP ACROSS
THE REGION DURING THE DAY ON THURSDAY. TEMPERATURES WILL BE WARM
ENOUGH THAT PRECIPITATION WILL FALL AS ALL RAIN THROUGH 06 UTC ON
FRIDAY. A SECOND SHORTWAVE TROUGH WILL DIVE SOUTHEASTWARD OUT OF
SOUTHERN CANADA AFTER 00 UTC ON FRIDAY BRINGING ANOTHER ROUND OF
PRECIPITATION TO THE REGION AND PUSHING A STRONG COLD FRONT EASTWARD. GFS
AND NAM BUFR SOUNDINGS INDICATE THAT PRECIPITATION WILL START OUT AS
RAIN AT MOST LOCATIONS AND BEGIN TO CHANGE OVER TO SNOW VERY SLOWLY
FROM NORTHWEST TO SOUTHEAST AFTER 06 UTC ON FRIDAY. PRECIPITATION
WILL BEGIN TO CHANGE OVER TO THE SOUTHERN HALF OF THE CWA AFTER 12
UTC ON FRIDAY ABOUT THE TIME DRIER AIR BEGINS TO COME SOUTHWARD
CUTTING THE PRECIPITATION OFF. ACCUMULATIONS SHOULD BE LESS THAN A
HALF AN INCH IN THE NORTHWEST.
A SECOND REINFORCING SURGE OF ARCTIC AIR ARRIVES AFTER 00 UTC ON
SATURDAY WITH A SECONDARY COLD FRONT. THERE ARE SOME TIMING DIFFERENCES
BETWEEN THE 00 UTC GFS AND ECMWF WITH THE ARCTIC AIR ARRIVING A
LITTLE MORE SLOWLY WITH THE ECWMF. MODELS SHOW A 1050 MB HIGH DROPPING
SOUTHWARD INTO THE PLAINS WITH A VERY TIGHT PRESSURE GRADIENT OVER
IOWA DURING THE DAY ON SATURDAY. THERE WILL BE LITTLE REBOUND IN
TEMPERATURES DURING THE DAY ON SATURDAY WITH STRONG COLD ADVECTION
AND GUSTY NORTHWEST WINDS. SATURDAY NIGHT WILL BE VERY COLD WITH
HIGH PRESSURE CENTERED OVER CENTRAL AND EASTERN IOWA WITH CLEAR
SKIES AND DEWPOINTS IN THE SINGLE DIGITS WHICH WILL ALLOW
TEMPERATURES TO DROP VERY QUICKLY AS THE WINDS BECOME CALM THROUGH
SUNDAY MORNING. LOW TEMPERATURES MAY VERY WELL NEED TO BE LOWER A
COUPLE MORE DEGREES FOR SUNDAY MORNING. THE SURFACE HIGH
SHIFTS TO THE SOUTHEAST OF THE REGION DURING THE DAY ON SUNDAY
ALLOWING FOR RETURN FLOW TO SETUP AND PULL WARMER AIR NORTHWARD FOR
THE BEGINNING OF NEXT WEEK.
A CLOSED UPPER LEVEL OVER THE SOUTHWESTERN US WILL BEGIN TO LUMBER
EASTWARD EARLY NEXT WEEK WITH MODELS NOW INDICATING PRECIPITATION
ASSOCIATED WITH THIS SYSTEM MOVING TO THE SOUTH OF HIGHWAY 34 DURING
THE DAY ON MONDAY. TEMPERATURES WILL STILL BE COLD ENOUGH ON MONDAY
THAT PRECIPITATION WOULD FALL AS A RAIN SNOW MIX.
AFTER MONDAY ANOTHER CLIPPER SYSTEM WILL DROP SOUTHWARD OUT OF
CANADA AND SWING A COLD FRONT THROUGH THE REGION ALLOWING FOR
TEMPERATURES A COUPLE OF DEGREES FOR THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 532 AM CST WED NOV 20 2013
MOISTURE SURGE AHEAD OF THE STORM SYSTEM MOVING INTO THE MIDWEST
THIS MORNING IS RESULTING IN VIRGA AND SPOTTY RAIN SHOWERS AND ICE
PELLETS. AS THE ATMOSPHERE MOISTENS...RAIN WILL BECOME MORE
WIDESPREAD BY MID MORNING...THEN CONTINUE THROUGH THE DAY INTO THE
EVENING HOURS. VFR CONDITIONS WILL DETERIORATE TO MVFR DURING THE
DAY. IT IS A LITTLE LESS CLEAR HOW THINGS WILL EVOLVE LATER THIS
EVENING AND OVERNIGHT...BUT MVFR CONDITIONS ARE LIKELY TO CONTINUE
WITH A LOW PROBABILITY OF IFR CONDITIONS IF LINGERING MOISTURE
LEADS TO THE FORMATION OF FOG. WOLF
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...WOLF
SHORT TERM...WOLF
LONG TERM...COUSINS
AVIATION...WOLF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
644 AM EST WED NOV 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EST WED NOV 20 2013
UPPER MICHIGAN IS BETWEEN SURFACE FEATURES THIS MORNING...WITH A
1036MB HIGH MOVING EAST FROM THE LOWER GREAT LAKES AND A 996MB LOW
BETWEEN LAKE WINNIPEG AND HUDSON BAY. A COLD FRONT STRETCHES
SOUTHWEST FROM THIS LOW THROUGH NORTHWEST MINNESOTA AND THROUGH THE
DAKOTAS. THE PRESSURE GRADIENT BETWEEN THESE THREE FEATURES HAS
LEAD TO BREEZY CONDITIONS EARLY THIS MORNING...ESPECIALLY OVER LAKE
SUPERIOR AND THE DOWNSLOPE AREAS OF CENTRAL UPPER MICHIGAN. KMQT VAD
WIND DATA SHOWS 45KT WINDS AT 2KFT AND THAT MATCHES UP WELL WITH
THE 46KT GUST RECORDED AT STANNARD ROCK LAST HOUR. THE REST OF
THE UPPER MICHIGAN HAS BEEN GUSTING TO 15-30KTS OVER THE LAST
COUPLE OF HOURS. EXPECT THE GUSTY WINDS TO CONTINUE THROUGH A GOOD
PORTION OF THE DAY TODAY AT VALUES SIMILAR TO WHAT WAS SEEN
OVERNIGHT. WITH A LITTLE BETTER MIXING...THE HIGHER GUSTS WILL
LIKELY BE MORE WIDESPREAD THAN THE SPORADIC VALUES SEEN OVERNIGHT.
FORTUNATELY...THE 40-50KT 925MB WINDS SHOULD STAY ABOVE THE SURFACE
DUE TO THE INVERSION INDICATED JUST BELOW THAT LEVEL. WITH THE
GRADIENT WEAKENING OVER THE AREA FROM WEST TO EAST THIS AFTERNOON
AND EVENING...ALONG THE WITH PRESSURE FALLS NORTH OF LAKE SUPERIOR
EXITING THIS MORNING...EXPECT A DIMINISHING TREND IN THE WINDS THIS
AFTERNOON/EVENING.
THE REST OF THE WEATHER FORECAST WILL DEPEND ON TWO FEATURES...THE
COLD FRONT TO THE WEST OF THE AREA THAT WILL MOVE THROUGH TONIGHT
AND THURSDAY AND A SHORTWAVE CURRENTLY PULLING OUT OF COLORADO.
THIS SHORTWAVE WILL SLIDE NORTHEAST TODAY AND ACROSS UPPER MICHIGAN
THIS EVENING AND EARLY OVERNIGHT HOURS. AS THIS OCCURS...THE COLD
FRONT WILL BE MOVING ACROSS WESTERN LAKE SUPERIOR. MID LEVEL
SOUTHWESTERLY FLOW AHEAD OF THIS WAVE HAS PRODUCED WIDESPREAD MID
CLOUDS FROM THE CENTRAL PLAINS INTO ONTARIO AND EXPECT THAT TO
CONTINUE THROUGH MUCH OF THE DAY TODAY. RADAR HAS BLOSSOMED OVER THE
LAST COUPLE OF HOURS FROM LAKE SUPERIOR THROUGH EASTERN IOWA AND ALL
ASSOCIATED WITH THE MID CLOUDS. THUS...THERE IS PROBABLY SOME PRECIP
FALLING OUT OF THOSE CLOUDS...BUT THE DRIER AIR IS EVAPORATING THE
PRECIP BEFORE REACHING THE SURFACE (NO OBS INDICATING RAIN). MODELS
INDICATING THERE COULD BE A FEW SHOWERS OVER CENTRAL LAKE SUPERIOR
AND THE KEWEENAW TODAY...BUT HAVE MAINLY LEFT AS SLIGHT CHANCES
SINCE THE DRIER LOW LEVELS WILL LIKELY EVAPORATE MUCH OF THE PRECIP.
THERE WAS A BRIEF PERIOD OF 2-3KFT RETURNS JUST NORTHEAST OF
MARQUETTE (WHICH HAD BEEN HINTED AT IN THE ECMWF AND A COUPLE OTHER
MODELS OVER THE LAST COUPLE OF DAYS)...BUT IT QUICKLY DISSIPATED.
THE DRY AIR INDICATED OVER THE AREA ON INITIAL RAP SOUNDINGS
(DEWPOINT DEPRESSIONS OF 15-20C BETWEEN 900-800MB) WILL CONTINUE
THROUGH MUCH OF THE DAY AND WILL PLAY A ROLE IN THE PRECIP TYPE
FORECAST FOR LATE THIS AFTERNOON AND TONIGHT.
MODELS SEEM TO HAVE DECENT AGREEMENT WITH THE PRECIPITATION TIMING
AND LOCATION FOR TONIGHT...AS THE LOWER LEVELS MOISTEN FROM TOP DOWN
WITH THE ARRIVAL OF THE SHORTWAVE. BEST FORCING FROM THE
SHORTWAVE...ALONG WITH 700-500 Q-VECTOR CONVERGENCE AND ISENTROPIC
ASCENT ON 280-290K SFCS TRACKS ACROSS THE MUCH OF THE CWA...WITH THE
GREATEST FOCUS OVER THE CENTRAL AND EAST THIS EVENING. THINK THAT
LAYER IS WHERE MUCH OF THE PRECIPITATION WILL INITIATE LATE THIS
AFTERNOON OVER NORTHERN WISCONSIN AND THEN LIFT NORTHEAST INTO UPPER
MICHIGAN. LOOKING UPSTREAM...THERE IS NOT MUCH FOR LOWER LEVEL
MOISTURE...AND THINK THAT IT WILL TAKE A LITTLE BIT FOR THE
PRECIPITATION TO COOL AND MOISTEN THE LOWER LEVELS. THIS CAN
SOMEWHAT BE SEEN ON MODEL QPF FIELDS WITH THEIR BLOTCHY NATURE AT
TIMES ALONG WITH 280-285K THETA-E SURFACES COND PRESS DEF VALUES
INDICATING SIGNIFICANT LIFT NEEDED TO MOISTEN THE CENTRAL/EASTERN
CWA DURING THE LATE AFTERNOON/EVENING. IN ADDITION...THE HIGHER
RESOLUTION RUNS ARE ALSO SHOWING SOME OF THE DOWNSLOPE FLOW OVER THE
NORTH CENTRAL EATING AWAY AT QPF AMOUNTS. THEREFORE...ALTHOUGH THE
CONFIDENCE IS HIGH ON TIMING/LOCATION...QPF AMOUNTS ARE MORE
UNCERTAIN DUE TO THE DRY AIR AND WILL LIKELY COME DOWN TO HOW
QUICKLY THINGS MOISTEN. THINK WE WILL GET PRECIPITATION...BUT
WONDERING IF THE DRY AIR WILL LOWER QPF AMOUNTS MORE THAN SOME OF
THE MODELS ARE INDICATING. ALSO...THERE ARE SOME HINTS ON THE 06Z
MODEL RUNS THAT THE MAIN PIECE OF SHORTWAVE ENERGY (NOTED BY THE PV
ANOMALY) WILL SLIDE SOUTH OF THE AREA (THROUGH CENTRAL WISCONSIN
AND LOWER MICHIGAN). AS THE SHORTWAVE SLIDES EAST OVERNIGHT...HAVE
DIMINISHED POPS FROM SOUTHWEST TO NORTHEAST.
AS FOR PRECIP TYPE...HAVE FOLLOWED THE WETBULB0 VALUES FOR MUCH OF
THE FORECAST...AS IT HANDLES WHERE THE THERMAL FIELDS WILL GO AS
EVAPORATIVE COOLING AND MOISTENING OCCURS. THIS LEADS TO MUCH OF
THE INTERIOR (HIGHER TERRAIN) WEST/CENTRAL TO QUICKLY TRANSITION TO
OR START AS SNOW. WITH THE UNCERTAINTY ON QPF...HAVE WENT WITH A
MIDDLE GROUND OF 0.1-0.18IN OF QPF OVER THE CENTRAL CWA WITH
LOWER AMOUNTS WEST AND EAST. WITH THAT AREA SHOWING MAINLY
SNOW...WOULD EXPECT AROUND AN INCH OF ACCUMULATION DURING THE
EVENING HOURS. OF COURSE...IF THE HIGHER QPF SHOWN IN THE 00Z
NAM/GFS IS CORRECT...COULD SEE AMOUNTS AROUND OR A LITTLE OVER 2
INCHES AROUND IRON/DICKINSON COUNTY BUT NOT COMPLETELY BUYING THEIR
QUICK 0.2-0.3IN OF QPF LATE THIS AFTERNOON. DID CONTINUE RAIN/SNOW
IN THE DOWNSLOPE WARMED AREAS NEAR LAKE SUPERIOR AND ALSO OVER THE
EAST. AS DEEPER MOISTURE PULLS OUT OF THE WEST OVERNIGHT...MUCH OF
THE REMAINING CLOUD ENDS UP BEING WARMER THAN -5C. THUS...IF ANY
PRECIPITATION DOES OCCUR...WOULD EXPECT IT TO BE AS FREEZING
DRIZZLE. PREVIOUS SHIFT HAD A GOOD HANDLE ON THIS IDEA AND HAVE
ONLY MADE MINOR ADJUSTMENTS TO PUSH IT A LITTLE TO THE WEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 513 AM EST WED NOV 20 2013
ALTHOUGH A FAIRLY ACTIVE PATTERN WILL BE THE RULE THRU THE LONG
TERM...NO SIGNIFICANT PCPN EVENTS ARE ANTICIPATED AS NW FLOW WILL
BECOME THE PREVAILING REGIME FROM THIS WEEKEND THRU AT LEAST THE
MIDDLE OF NEXT WEEK. ACTIVE PATTERN WILL COME IN THE FORM OF A
NUMBER OF SHORTWAVES PRODUCING MOSTLY LIGHT PCPN...THOUGH LAKE
SUPERIOR WILL PROVIDE ENHANCEMENT. THE NW FLOW REGIME WILL SET IN
THIS WEEKEND AS A MEAN RIDGE DEVELOPS ALONG THE W COAST WITH
DOWNSTREAM TROF GENERALLY FROM THE MISSISSIPPI VALLEY TO THE E
COAST. INITIAL SURGE OF COLD AIR THIS WEEKEND ASSOCIATED WITH
DEEPENING TROF WILL BE THE COLDEST OF THE SEASON SO FAR. SOURCE
REGION OF THE AIR MASS IS THE YUKON WHERE A NUMBER OF SITES HAVE
BEEN RECORDING TEMPS IN THE -25 TO -35F RANGE OVER THE LAST DAY OR
SO. SHOT OF ARCTIC AIR WILL BE BRIEF AS TROF TEMPORARILY DEAMPLIFIES
LATE WEEKEND AHEAD OF THE NEXT SHORTWAVE THAT DROPS SE. THAT WAVE
WILL THEN REAMPLIFY THE TROF EARLY NEXT WEEK...BRINGING MORE COLD
AIR INTO THE AREA...THOUGH PROBABLY NOT QUITE AS COLD AS THE AIR
MASS THIS WEEKEND. FARTHER DOWN THE LINE INTO LATE NEXT WEEK...THERE
ARE SOME HINTS THAT THE FLOW PATTERN WILL DEAMPLIFY SOME...
SUGGESTING NO SIGNIFICANT PCPN EVENTS ALONG WITH TEMPS RETURNING TO
AROUND NORMAL.
BEGINNING THU...SHORTWAVE LEADING TO PCPN TONIGHT WILL BE EXITING TO
THE NE. MAY SEE LINGERING PCPN OVER THE E IN THE MORNING AND ALSO IN
THE UPSLOPE AREAS OF THE W. WITH DEEPER MOISTURE PULLING OUT...THERE
COULD BE A LITTLE DZ/FZDZ OVER THE FAR W EARLY...THOUGH THERE IS A
FAIR AMOUNT OF UNCERTAINTY IN HOW MUCH DRYING OCCURS ALOFT.
OTHERWISE...A COLD FRONT WILL BE MOVING ACROSS THE FCST AREA THU.
CAA IS NOT ESPECIALLY STRONG...SO THERE SHOULD STILL BE SOME TEMP
RISE OVER THE W IN THE MORNING BEFORE TEMPS BEGIN FALLING IN THE
AFTN. TEMPS OVER THE E SHOULD RISE TO THE LWR 40S UNDER DELAYED CAA.
IN THE AFTN...WELL BEHIND SFC COLD FRONT...IT APPEARS A BAND OF -SN
MAY ORGANIZE ACROSS ROUGHLY THE W HALF OF THE FCST AREA WITHIN A
ZONE OF LOW/MID LEVEL FRONTOGENESIS UNDERNEATH RIGHT ENTRANCE OF
UPPER JET FROM THE NRN PLAINS TO HUDSON BAY AND LEFT EXIT OF JET
EXTENDING FROM THE SW STATES TO THE MIDWEST.
WITH STRENGTHENING FRONTOGENESIS/UPPER DIVERGENCE TRANSLATING ACROSS
THE UPPER LAKES THU NIGHT AHEAD OF NEXT SHORTWAVE SWINGING ACROSS
THE NRN PLAINS/UPPER MISSISSIPPI VALLEY...EXPECT A PERIOD OF PCPN
ACROSS THE FCST AREA. PER FCST SOUNDINGS AND WETBULB ZERO HEIGHTS
ABOVE 1500FT...PCPN SHOULD START AS MAINLY RA OVER THE E BEFORE IT
CHANGES TO SNOW. SNOW WILL BE THE RULE OVER THE W. WITH NOT MUCH IN
THE WAY OF ISENTROPIC ASCENT NOTED...PCPN SHOULD REMAIN ON THE LIGHT
SIDE. CONSENSUS OF MODEL GUIDANCE SHOWS PCPN AMOUNTS IN THE 0.10 TO
0.20 INCH RANGE. WITH A HIGH DGZ GENERALLY BTWN 11K AND 15KFT AND
MOSTLY ABOVE THE BEST UPWARD MOTION...SNOW TO WATER RATIOS WILL BE
ON THE LOW SIDE...PROBABLY 10-15 TO 1. SO...RIGHT NOW IT LOOKS LIKE
A GENERAL 1-2 TO MAYBE 3 INCH SNOW ACCUMULATION ACROSS THE AREA THU
NIGHT INTO FRI MORNING. WITH 850MB TEMPS FALLING TO -8 TO -10C
DURING THE PERIOD OF -SN...THERE WILL BE SOME LAKE ENHANCEMENT UNDER
NRLY LOW-LEVEL FLOW...AND THAT SHOULD LEAD TO GREATEST ACCUMULATIONS
OVER THE HIGHER TERRAIN NEAR LAKE SUPERIOR. HOWEVER...WITH HIGH
DGZ...ENHANCEMENT SHOULDN`T ADD MUCH TO SYNOPTIC SNOW AMOUNTS.
-SN WILL END FROM W TO E FRI IN THE WAKE OF SHORTWAVE...THOUGH A FEW
-SHSN MAY LINGER THRU THE AFTN OFF LAKE SUPERIOR OVER THE ERN FCST
AREA UNDER 850MB TEMPS AROUND -10C.
ATTENTION THEN TURNS TO THE NEXT SHORTWAVE DROPPING SE AND LEADING
TO THE AFOREMENTIONED WEEKEND TROF AMPLIFICATION AND ARCTIC AIR.
BRIEF PERIOD OF VIGOROUS DEEP LAYER FORCING PER QVECTORS OVERTOP
MORE THAN ADEQUATE OVERWATER INSTABILITY WILL YIELD THE TYPICAL
BURST OF MDT/HVY LAKE ENHANCED SNOW SWEEPING OFF LAKE SUPERIOR ALONG
THE ASSOCIATED ARCTIC COLD FRONT FRI NIGHT/EARLY SAT. IN THE WAKE OF
THE FRONT...850MB TEMPS FALL TO -18 TO -21C SAT...RESULTING IN
VIGOROUS NW/NNW FLOW ORIENTED LAKE CONVECTION. CONSENSUS OF GUIDANCE
IS FOR DEEP MOISTURE TO LINGER LONGEST OVER THE ERN FCST AREA. GFS
FCST SOUNDINGS SHOW MOISTURE UP TO 10KFT OR SO. COMBINED WITH LAKE
NIPIGON PRECONDITIONING AND DGZ LIKELY WELL CENTERED WITHIN THE
UPWARD MOTION ZONE...A SIGNIFICANT LAKE EFFECT EVENT LOOKS TO BE
SETTING UP FOR ALGER/LUCE/NRN SCHOOLCRAFT. GUSTY WINDS OF 30-40MPH
WILL ALSO LEAD TO INCREASING BLSN ISSUES AS SNOW ACCUMULATES. OUT
W...SHORTER FETCH...LOWER DGZ AND MOISTURE EXTENDING TO AROUND 6KFT
WILL WORK TO LIMIT SNOW ACCUMULATIONS COMPARED TO THE E.
HOWEVER...TERRAIN ENHANCEMENT PLAYS A BIGGER ROLE OVER THE W THAN
THE E...AND BOUNDARY LAYER WINDS LOOK SUPPORTIVE OF THE TYPICAL
ENHANCED CONVERGENCE AREA FOR GOGEBIC/ONTONAGON INTO CNTRL HOUGHTON
COUNTIES. AS A RESULT...SIGNIFICANT SNOW MAY ALSO OCCUR IN THAT AREA
AS WELL. ANTICIPATE AT LEAST SOLID ADVY FOR THE KEWEENAW...AND THERE
MAY BE A PERIOD WITH WINDS HAVING ENOUGH NRLY COMPONENT FOR
BARAGA/MARQUETTE COUNTIES TO SEE ADVY AMOUNTS AS WELL. ALL OF THESE
DETAILS WILL BE SORTED OUT ONCE THE EVENT MOVES INTO THE SHORT TERM.
OTHERWISE...IT WILL SEEM LIKE MID WINTER CONDITIONS ACROSS THE AREA
SAT/SAT NIGHT WITH GUSTY WINDS/COLD AIR AND WIND CHILLS FALLING TO
ZERO OR BLO.
LES WILL END SUN FROM W TO E AS WINDS BACK TO THE SW AHEAD OF THE
NEXT SHORTWAVE DIVING SE THRU SCNTRL CANADA. HOWEVER...DEVELOPING
STRONG WAA PATTERN MAY LEAD TO AN AREA OF -SN STREAKING SE INTO THE
AREA SUN AFTN/NIGHT. ANOTHER PERIOD OF LAKE EFFECT SNOW SHOULD SET
UP BEHIND THIS SYSTEM EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM EST WED NOV 20 2013
GUSTY WINDS WILL CONTINUE AT ALL THREE SITES THROUGH MID AFTERNOON
AHEAD OF A COLD FRONT MOVING THROUGH MINNESOTA. IN ADDITION...A
SMALL POCKET OF MVFR CEILINGS IS AFFECTING PORTIONS OF
CENTRAL/EASTERN UPPER MICHIGAN THIS MORNING AND WILL LIKELY
CONTINUE OFF AN ON OVER THE FIRST COUPLE OF THE TAF PERIOD AT KSAW.
OTHERWISE...10KFT CEILINGS WILL CONTINUE TODAY AND THEN LOWER LATER
THIS AFTERNOON AHEAD OF AN APPROACHING DISTURBANCE.
THIS DISTURBANCE/SHORTWAVE WILL LEAD TO THE POTENTIAL FOR RAIN/SNOW
SHOWERS INITIALLY AND THEN QUICKLY TRANSITIONING TO ALL SNOW.
THERE IS SOME UNCERTAINTY ON THE EXACT LOCATION OF THE HEAVIEST
SHOWERS...BUT CURRENT THINKING IS THAT IT WILL BRUSH KIWD/KCMX AND
LARGELY AFFECT KSAW. THEREFORE...HAVE THE LOWEST VISIBILITIES AT
KSAW. THIS UNCERTAINTY ALSO AFFECTS CEILINGS AT KCMX/KIWD THIS
EVENING...AS IF THE PRECIPITATION IS FARTHER WEST...THE CEILINGS
WILL BE LOWER. THIS DISTURBANCE WILL SHIFT NORTHEAST OVERNIGHT AND
BRING AN END TO THE SNOW...BUT STILL EXPECT MVFR/IFR CEILINGS TO
REMAIN IN PLACE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 441 AM EST WED NOV 20 2013
SOUTHERLY GALES TO 35-40KTS WILL CONTINUE THROUGH MOST OF THE
DAYLIGHT HOURS TODAY OVER EASTERN LAKE SUPERIOR AHEAD OF
A COLD FRONT MOVING THROUGH MINNESOTA TODAY. TIMING OF THE ONGOING
GALE WARNING LOOKS GOOD AND WON/T MAKE ANY CHANGES AT THIS TIME. AS
THE FRONT NEARS LATE THIS AFTERNOON AND EVENING...EXPECT THE WINDS
TO DIMINISH FROM WEST TO EAST THROUGH THE NIGHT. THE FRONT WILL
SLOWLY MOVE EAST ACROSS LAKE SUPERIOR TONIGHT AND THURSDAY...WHICH
WILL SHIFT THE WINDS TO THE NORTHWEST 20-30KTS ON THURSDAY. A HIGH
PRESSURE RIDGE MOVING OVER THE LAKE ON THURSDAY NIGHT WILL SHIFT
WINDS TO THE NORTH AND DIMINISH THEM THURSDAY NIGHT THROUGH FRIDAY.
A WEAK LOW TRACKING FROM THE SOUTHERN PLAINS THROUGH THE LOWER GREAT
LAKES ON FRIDAY WILL KEEP THE NORTHERLY WINDS IN PLACE DUE TO A WEAK
TROUGH SETTING UP OVER UPPER MICHIGAN. THIS TROUGH WILL DIVE SOUTH
ON FRIDAY NIGHT AND WHEN COMBINED WITH A STRONG HIGH BUILDING INTO
THE NORTHERN PLAINS...EXPECT NORTHWESTERLY WINDS TO INCREASE TO
GALES TO 35-40KTS ON SATURDAY AND CONTINUE INTO SATURDAY NIGHT. THIS
EVENT WILL BE SHORT LIVED...AS A RIDGE FROM THAT STRONG HIGH SHIFTS
EAST OVER THE UPPER GREAT LAKES ON SUNDAY AND BRINGS WINDS BELOW
25KTS BY SUNDAY AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LSZ244-245-266-
267.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ264.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ249>251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
514 AM EST WED NOV 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EST WED NOV 20 2013
UPPER MICHIGAN IS BETWEEN SURFACE FEATURES THIS MORNING...WITH A
1036MB HIGH MOVING EAST FROM THE LOWER GREAT LAKES AND A 996MB LOW
BETWEEN LAKE WINNIPEG AND HUDSON BAY. A COLD FRONT STRETCHES
SOUTHWEST FROM THIS LOW THROUGH NORTHWEST MINNESOTA AND THROUGH THE
DAKOTAS. THE PRESSURE GRADIENT BETWEEN THESE THREE FEATURES HAS
LEAD TO BREEZY CONDITIONS EARLY THIS MORNING...ESPECIALLY OVER LAKE
SUPERIOR AND THE DOWNSLOPE AREAS OF CENTRAL UPPER MICHIGAN. KMQT VAD
WIND DATA SHOWS 45KT WINDS AT 2KFT AND THAT MATCHES UP WELL WITH
THE 46KT GUST RECORDED AT STANNARD ROCK LAST HOUR. THE REST OF
THE UPPER MICHIGAN HAS BEEN GUSTING TO 15-30KTS OVER THE LAST
COUPLE OF HOURS. EXPECT THE GUSTY WINDS TO CONTINUE THROUGH A GOOD
PORTION OF THE DAY TODAY AT VALUES SIMILAR TO WHAT WAS SEEN
OVERNIGHT. WITH A LITTLE BETTER MIXING...THE HIGHER GUSTS WILL
LIKELY BE MORE WIDESPREAD THAN THE SPORADIC VALUES SEEN OVERNIGHT.
FORTUNATELY...THE 40-50KT 925MB WINDS SHOULD STAY ABOVE THE SURFACE
DUE TO THE INVERSION INDICATED JUST BELOW THAT LEVEL. WITH THE
GRADIENT WEAKENING OVER THE AREA FROM WEST TO EAST THIS AFTERNOON
AND EVENING...ALONG THE WITH PRESSURE FALLS NORTH OF LAKE SUPERIOR
EXITING THIS MORNING...EXPECT A DIMINISHING TREND IN THE WINDS THIS
AFTERNOON/EVENING.
THE REST OF THE WEATHER FORECAST WILL DEPEND ON TWO FEATURES...THE
COLD FRONT TO THE WEST OF THE AREA THAT WILL MOVE THROUGH TONIGHT
AND THURSDAY AND A SHORTWAVE CURRENTLY PULLING OUT OF COLORADO.
THIS SHORTWAVE WILL SLIDE NORTHEAST TODAY AND ACROSS UPPER MICHIGAN
THIS EVENING AND EARLY OVERNIGHT HOURS. AS THIS OCCURS...THE COLD
FRONT WILL BE MOVING ACROSS WESTERN LAKE SUPERIOR. MID LEVEL
SOUTHWESTERLY FLOW AHEAD OF THIS WAVE HAS PRODUCED WIDESPREAD MID
CLOUDS FROM THE CENTRAL PLAINS INTO ONTARIO AND EXPECT THAT TO
CONTINUE THROUGH MUCH OF THE DAY TODAY. RADAR HAS BLOSSOMED OVER THE
LAST COUPLE OF HOURS FROM LAKE SUPERIOR THROUGH EASTERN IOWA AND ALL
ASSOCIATED WITH THE MID CLOUDS. THUS...THERE IS PROBABLY SOME PRECIP
FALLING OUT OF THOSE CLOUDS...BUT THE DRIER AIR IS EVAPORATING THE
PRECIP BEFORE REACHING THE SURFACE (NO OBS INDICATING RAIN). MODELS
INDICATING THERE COULD BE A FEW SHOWERS OVER CENTRAL LAKE SUPERIOR
AND THE KEWEENAW TODAY...BUT HAVE MAINLY LEFT AS SLIGHT CHANCES
SINCE THE DRIER LOW LEVELS WILL LIKELY EVAPORATE MUCH OF THE PRECIP.
THERE WAS A BRIEF PERIOD OF 2-3KFT RETURNS JUST NORTHEAST OF
MARQUETTE (WHICH HAD BEEN HINTED AT IN THE ECMWF AND A COUPLE OTHER
MODELS OVER THE LAST COUPLE OF DAYS)...BUT IT QUICKLY DISSIPATED.
THE DRY AIR INDICATED OVER THE AREA ON INITIAL RAP SOUNDINGS
(DEWPOINT DEPRESSIONS OF 15-20C BETWEEN 900-800MB) WILL CONTINUE
THROUGH MUCH OF THE DAY AND WILL PLAY A ROLE IN THE PRECIP TYPE
FORECAST FOR LATE THIS AFTERNOON AND TONIGHT.
MODELS SEEM TO HAVE DECENT AGREEMENT WITH THE PRECIPITATION TIMING
AND LOCATION FOR TONIGHT...AS THE LOWER LEVELS MOISTEN FROM TOP DOWN
WITH THE ARRIVAL OF THE SHORTWAVE. BEST FORCING FROM THE
SHORTWAVE...ALONG WITH 700-500 Q-VECTOR CONVERGENCE AND ISENTROPIC
ASCENT ON 280-290K SFCS TRACKS ACROSS THE MUCH OF THE CWA...WITH THE
GREATEST FOCUS OVER THE CENTRAL AND EAST THIS EVENING. THINK THAT
LAYER IS WHERE MUCH OF THE PRECIPITATION WILL INITIATE LATE THIS
AFTERNOON OVER NORTHERN WISCONSIN AND THEN LIFT NORTHEAST INTO UPPER
MICHIGAN. LOOKING UPSTREAM...THERE IS NOT MUCH FOR LOWER LEVEL
MOISTURE...AND THINK THAT IT WILL TAKE A LITTLE BIT FOR THE
PRECIPITATION TO COOL AND MOISTEN THE LOWER LEVELS. THIS CAN
SOMEWHAT BE SEEN ON MODEL QPF FIELDS WITH THEIR BLOTCHY NATURE AT
TIMES ALONG WITH 280-285K THETA-E SURFACES COND PRESS DEF VALUES
INDICATING SIGNIFICANT LIFT NEEDED TO MOISTEN THE CENTRAL/EASTERN
CWA DURING THE LATE AFTERNOON/EVENING. IN ADDITION...THE HIGHER
RESOLUTION RUNS ARE ALSO SHOWING SOME OF THE DOWNSLOPE FLOW OVER THE
NORTH CENTRAL EATING AWAY AT QPF AMOUNTS. THEREFORE...ALTHOUGH THE
CONFIDENCE IS HIGH ON TIMING/LOCATION...QPF AMOUNTS ARE MORE
UNCERTAIN DUE TO THE DRY AIR AND WILL LIKELY COME DOWN TO HOW
QUICKLY THINGS MOISTEN. THINK WE WILL GET PRECIPITATION...BUT
WONDERING IF THE DRY AIR WILL LOWER QPF AMOUNTS MORE THAN SOME OF
THE MODELS ARE INDICATING. ALSO...THERE ARE SOME HINTS ON THE 06Z
MODEL RUNS THAT THE MAIN PIECE OF SHORTWAVE ENERGY (NOTED BY THE PV
ANOMALY) WILL SLIDE SOUTH OF THE AREA (THROUGH CENTRAL WISCONSIN
AND LOWER MICHIGAN). AS THE SHORTWAVE SLIDES EAST OVERNIGHT...HAVE
DIMINISHED POPS FROM SOUTHWEST TO NORTHEAST.
AS FOR PRECIP TYPE...HAVE FOLLOWED THE WETBULB0 VALUES FOR MUCH OF
THE FORECAST...AS IT HANDLES WHERE THE THERMAL FIELDS WILL GO AS
EVAPORATIVE COOLING AND MOISTENING OCCURS. THIS LEADS TO MUCH OF
THE INTERIOR (HIGHER TERRAIN) WEST/CENTRAL TO QUICKLY TRANSITION TO
OR START AS SNOW. WITH THE UNCERTAINTY ON QPF...HAVE WENT WITH A
MIDDLE GROUND OF 0.1-0.18IN OF QPF OVER THE CENTRAL CWA WITH
LOWER AMOUNTS WEST AND EAST. WITH THAT AREA SHOWING MAINLY
SNOW...WOULD EXPECT AROUND AN INCH OF ACCUMULATION DURING THE
EVENING HOURS. OF COURSE...IF THE HIGHER QPF SHOWN IN THE 00Z
NAM/GFS IS CORRECT...COULD SEE AMOUNTS AROUND OR A LITTLE OVER 2
INCHES AROUND IRON/DICKINSON COUNTY BUT NOT COMPLETELY BUYING THEIR
QUICK 0.2-0.3IN OF QPF LATE THIS AFTERNOON. DID CONTINUE RAIN/SNOW
IN THE DOWNSLOPE WARMED AREAS NEAR LAKE SUPERIOR AND ALSO OVER THE
EAST. AS DEEPER MOISTURE PULLS OUT OF THE WEST OVERNIGHT...MUCH OF
THE REMAINING CLOUD ENDS UP BEING WARMER THAN -5C. THUS...IF ANY
PRECIPITATION DOES OCCUR...WOULD EXPECT IT TO BE AS FREEZING
DRIZZLE. PREVIOUS SHIFT HAD A GOOD HANDLE ON THIS IDEA AND HAVE
ONLY MADE MINOR ADJUSTMENTS TO PUSH IT A LITTLE TO THE WEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 513 AM EST WED NOV 20 2013
ALTHOUGH A FAIRLY ACTIVE PATTERN WILL BE THE RULE THRU THE LONG
TERM...NO SIGNIFICANT PCPN EVENTS ARE ANTICIPATED AS NW FLOW WILL
BECOME THE PREVAILING REGIME FROM THIS WEEKEND THRU AT LEAST THE
MIDDLE OF NEXT WEEK. ACTIVE PATTERN WILL COME IN THE FORM OF A
NUMBER OF SHORTWAVES PRODUCING MOSTLY LIGHT PCPN...THOUGH LAKE
SUPERIOR WILL PROVIDE ENHANCEMENT. THE NW FLOW REGIME WILL SET IN
THIS WEEKEND AS A MEAN RIDGE DEVELOPS ALONG THE W COAST WITH
DOWNSTREAM TROF GENERALLY FROM THE MISSISSIPPI VALLEY TO THE E
COAST. INITIAL SURGE OF COLD AIR THIS WEEKEND ASSOCIATED WITH
DEEPENING TROF WILL BE THE COLDEST OF THE SEASON SO FAR. SOURCE
REGION OF THE AIR MASS IS THE YUKON WHERE A NUMBER OF SITES HAVE
BEEN RECORDING TEMPS IN THE -25 TO -35F RANGE OVER THE LAST DAY OR
SO. SHOT OF ARCTIC AIR WILL BE BRIEF AS TROF TEMPORARILY DEAMPLIFIES
LATE WEEKEND AHEAD OF THE NEXT SHORTWAVE THAT DROPS SE. THAT WAVE
WILL THEN REAMPLIFY THE TROF EARLY NEXT WEEK...BRINGING MORE COLD
AIR INTO THE AREA...THOUGH PROBABLY NOT QUITE AS COLD AS THE AIR
MASS THIS WEEKEND. FARTHER DOWN THE LINE INTO LATE NEXT WEEK...THERE
ARE SOME HINTS THAT THE FLOW PATTERN WILL DEAMPLIFY SOME...
SUGGESTING NO SIGNIFICANT PCPN EVENTS ALONG WITH TEMPS RETURNING TO
AROUND NORMAL.
BEGINNING THU...SHORTWAVE LEADING TO PCPN TONIGHT WILL BE EXITING TO
THE NE. MAY SEE LINGERING PCPN OVER THE E IN THE MORNING AND ALSO IN
THE UPSLOPE AREAS OF THE W. WITH DEEPER MOISTURE PULLING OUT...THERE
COULD BE A LITTLE DZ/FZDZ OVER THE FAR W EARLY...THOUGH THERE IS A
FAIR AMOUNT OF UNCERTAINTY IN HOW MUCH DRYING OCCURS ALOFT.
OTHERWISE...A COLD FRONT WILL BE MOVING ACROSS THE FCST AREA THU.
CAA IS NOT ESPECIALLY STRONG...SO THERE SHOULD STILL BE SOME TEMP
RISE OVER THE W IN THE MORNING BEFORE TEMPS BEGIN FALLING IN THE
AFTN. TEMPS OVER THE E SHOULD RISE TO THE LWR 40S UNDER DELAYED CAA.
IN THE AFTN...WELL BEHIND SFC COLD FRONT...IT APPEARS A BAND OF -SN
MAY ORGANIZE ACROSS ROUGHLY THE W HALF OF THE FCST AREA WITHIN A
ZONE OF LOW/MID LEVEL FRONTOGENESIS UNDERNEATH RIGHT ENTRANCE OF
UPPER JET FROM THE NRN PLAINS TO HUDSON BAY AND LEFT EXIT OF JET
EXTENDING FROM THE SW STATES TO THE MIDWEST.
WITH STRENGTHENING FRONTOGENESIS/UPPER DIVERGENCE TRANSLATING ACROSS
THE UPPER LAKES THU NIGHT AHEAD OF NEXT SHORTWAVE SWINGING ACROSS
THE NRN PLAINS/UPPER MISSISSIPPI VALLEY...EXPECT A PERIOD OF PCPN
ACROSS THE FCST AREA. PER FCST SOUNDINGS AND WETBULB ZERO HEIGHTS
ABOVE 1500FT...PCPN SHOULD START AS MAINLY RA OVER THE E BEFORE IT
CHANGES TO SNOW. SNOW WILL BE THE RULE OVER THE W. WITH NOT MUCH IN
THE WAY OF ISENTROPIC ASCENT NOTED...PCPN SHOULD REMAIN ON THE LIGHT
SIDE. CONSENSUS OF MODEL GUIDANCE SHOWS PCPN AMOUNTS IN THE 0.10 TO
0.20 INCH RANGE. WITH A HIGH DGZ GENERALLY BTWN 11K AND 15KFT AND
MOSTLY ABOVE THE BEST UPWARD MOTION...SNOW TO WATER RATIOS WILL BE
ON THE LOW SIDE...PROBABLY 10-15 TO 1. SO...RIGHT NOW IT LOOKS LIKE
A GENERAL 1-2 TO MAYBE 3 INCH SNOW ACCUMULATION ACROSS THE AREA THU
NIGHT INTO FRI MORNING. WITH 850MB TEMPS FALLING TO -8 TO -10C
DURING THE PERIOD OF -SN...THERE WILL BE SOME LAKE ENHANCEMENT UNDER
NRLY LOW-LEVEL FLOW...AND THAT SHOULD LEAD TO GREATEST ACCUMULATIONS
OVER THE HIGHER TERRAIN NEAR LAKE SUPERIOR. HOWEVER...WITH HIGH
DGZ...ENHANCEMENT SHOULDN`T ADD MUCH TO SYNOPTIC SNOW AMOUNTS.
-SN WILL END FROM W TO E FRI IN THE WAKE OF SHORTWAVE...THOUGH A FEW
-SHSN MAY LINGER THRU THE AFTN OFF LAKE SUPERIOR OVER THE ERN FCST
AREA UNDER 850MB TEMPS AROUND -10C.
ATTENTION THEN TURNS TO THE NEXT SHORTWAVE DROPPING SE AND LEADING
TO THE AFOREMENTIONED WEEKEND TROF AMPLIFICATION AND ARCTIC AIR.
BRIEF PERIOD OF VIGOROUS DEEP LAYER FORCING PER QVECTORS OVERTOP
MORE THAN ADEQUATE OVERWATER INSTABILITY WILL YIELD THE TYPICAL
BURST OF MDT/HVY LAKE ENHANCED SNOW SWEEPING OFF LAKE SUPERIOR ALONG
THE ASSOCIATED ARCTIC COLD FRONT FRI NIGHT/EARLY SAT. IN THE WAKE OF
THE FRONT...850MB TEMPS FALL TO -18 TO -21C SAT...RESULTING IN
VIGOROUS NW/NNW FLOW ORIENTED LAKE CONVECTION. CONSENSUS OF GUIDANCE
IS FOR DEEP MOISTURE TO LINGER LONGEST OVER THE ERN FCST AREA. GFS
FCST SOUNDINGS SHOW MOISTURE UP TO 10KFT OR SO. COMBINED WITH LAKE
NIPIGON PRECONDITIONING AND DGZ LIKELY WELL CENTERED WITHIN THE
UPWARD MOTION ZONE...A SIGNIFICANT LAKE EFFECT EVENT LOOKS TO BE
SETTING UP FOR ALGER/LUCE/NRN SCHOOLCRAFT. GUSTY WINDS OF 30-40MPH
WILL ALSO LEAD TO INCREASING BLSN ISSUES AS SNOW ACCUMULATES. OUT
W...SHORTER FETCH...LOWER DGZ AND MOISTURE EXTENDING TO AROUND 6KFT
WILL WORK TO LIMIT SNOW ACCUMULATIONS COMPARED TO THE E.
HOWEVER...TERRAIN ENHANCEMENT PLAYS A BIGGER ROLE OVER THE W THAN
THE E...AND BOUNDARY LAYER WINDS LOOK SUPPORTIVE OF THE TYPICAL
ENHANCED CONVERGENCE AREA FOR GOGEBIC/ONTONAGON INTO CNTRL HOUGHTON
COUNTIES. AS A RESULT...SIGNIFICANT SNOW MAY ALSO OCCUR IN THAT AREA
AS WELL. ANTICIPATE AT LEAST SOLID ADVY FOR THE KEWEENAW...AND THERE
MAY BE A PERIOD WITH WINDS HAVING ENOUGH NRLY COMPONENT FOR
BARAGA/MARQUETTE COUNTIES TO SEE ADVY AMOUNTS AS WELL. ALL OF THESE
DETAILS WILL BE SORTED OUT ONCE THE EVENT MOVES INTO THE SHORT TERM.
OTHERWISE...IT WILL SEEM LIKE MID WINTER CONDITIONS ACROSS THE AREA
SAT/SAT NIGHT WITH GUSTY WINDS/COLD AIR AND WIND CHILLS FALLING TO
ZERO OR BLO.
LES WILL END SUN FROM W TO E AS WINDS BACK TO THE SW AHEAD OF THE
NEXT SHORTWAVE DIVING SE THRU SCNTRL CANADA. HOWEVER...DEVELOPING
STRONG WAA PATTERN MAY LEAD TO AN AREA OF -SN STREAKING SE INTO THE
AREA SUN AFTN/NIGHT. ANOTHER PERIOD OF LAKE EFFECT SNOW SHOULD SET
UP BEHIND THIS SYSTEM EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1212 AM EST WED NOV 20 2013
EXPECT VFR CONDITIONS OVERNIGHT THROUGH WED MORNING AS THE LOW-LEVEL
AIR MASS REMAINS DRY. A TIGHT PRES GRADIENT BTWN STRENGTHENING
HIGH PRES TO THE E AND LOW PRES MOVING TOWARD HUDSON BAY WILL BRING
STRONG SOUTHERLY FLOW TO THE AREA TONIGHT. WITH SFC WINDS LARGELY
DECOUPLED DUE TO INVERSION... LLWS IS EXPECTED EXCEPT FOR AT IWD
WHERE DECOUPLING IS NOT STRONG ENOUGH TO KEEP WINDS FROM GUSTING TO
NEAR 30KT. WAA PCPN MOVING IN MID TO LATE AFTERNOON WILL DROP CIGS
TO AROUND MVFR WITH VSBY REMAINING MAINLY VFR. PCPN TYPE MAY START
OUT BRIEFLY AS RAIN AND THEN CHANGE TO SNOW TOWARD 00Z/THU. PCPN
CHANGING TO SNOW DURING THE EVENING WILL DROP CONDITIONS TOWARD THE
LOWER END MVFR WITH EVEN IFR CIGS POSSIBLE BY LATE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 441 AM EST WED NOV 20 2013
SOUTHERLY GALES TO 35-40KTS WILL CONTINUE THROUGH MOST OF THE
DAYLIGHT HOURS TODAY OVER EASTERN LAKE SUPERIOR AHEAD OF
A COLD FRONT MOVING THROUGH MINNESOTA TODAY. TIMING OF THE ONGOING
GALE WARNING LOOKS GOOD AND WON/T MAKE ANY CHANGES AT THIS TIME. AS
THE FRONT NEARS LATE THIS AFTERNOON AND EVENING...EXPECT THE WINDS
TO DIMINISH FROM WEST TO EAST THROUGH THE NIGHT. THE FRONT WILL
SLOWLY MOVE EAST ACROSS LAKE SUPERIOR TONIGHT AND THURSDAY...WHICH
WILL SHIFT THE WINDS TO THE NORTHWEST 20-30KTS ON THURSDAY. A HIGH
PRESSURE RIDGE MOVING OVER THE LAKE ON THURSDAY NIGHT WILL SHIFT
WINDS TO THE NORTH AND DIMINISH THEM THURSDAY NIGHT THROUGH FRIDAY.
A WEAK LOW TRACKING FROM THE SOUTHERN PLAINS THROUGH THE LOWER GREAT
LAKES ON FRIDAY WILL KEEP THE NORTHERLY WINDS IN PLACE DUE TO A WEAK
TROUGH SETTING UP OVER UPPER MICHIGAN. THIS TROUGH WILL DIVE SOUTH
ON FRIDAY NIGHT AND WHEN COMBINED WITH A STRONG HIGH BUILDING INTO
THE NORTHERN PLAINS...EXPECT NORTHWESTERLY WINDS TO INCREASE TO
GALES TO 35-40KTS ON SATURDAY AND CONTINUE INTO SATURDAY NIGHT. THIS
EVENT WILL BE SHORT LIVED...AS A RIDGE FROM THAT STRONG HIGH SHIFTS
EAST OVER THE UPPER GREAT LAKES ON SUNDAY AND BRINGS WINDS BELOW
25KTS BY SUNDAY AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LSZ244-245-266-
267.
GALE WARNING UNTIL 11 AM EST THIS MORNING FOR LSZ264.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ249>251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
603 AM CST WED NOV 20 2013
.UPDATED FOR 12Z AVIATION DISCUSSION...
ISSUED AT 555 AM CST WED NOV 20 2013
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST WED NOV 20 2013
EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH GFS20.00 500MB
HEIGHTS AND WINDS SHOWS SPLIT FLOW ACROSS NORTH AMERICA...WITH THE
NORTHERN STREAM SET UP ACROSS SOUTHERN CANADA...WHILE THE ZONAL
SOUTHERN STREAM WAS POSITIONED FROM SOUTHERN CALIFORNIA TO GEORGIA.
A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE CURRENTLY LOCATED ACROSS
EASTERN COLORADO WILL TRACK NORTHEASTWARD TODAY...AND THIS WILL
PROVIDE THE LARGE SCALE FORCING FOR A FEW LIGHT RAIN/SNOW SHOWERS IN
WESTERN WISCONSIN AND FAR EASTERN MINNESOTA. RAP FORECAST SOUNDINGS
FOR EAU CLAIRE SHOW AROUND 15UB/S OF LIFT CENTERED AROUND THE 600MB
LAYER..WITH AN ISOTHERMAL LAYER IN THE LOWEST 4000FT HOVERING AROUND
0C. THE WARM NEAR SURFACE TEMPERATURES SHOULD MELT THE PRECIP DURING
THE AFTERNOON...BUT EXPECT A TRANSITION TO A RAIN/SNOW MIX DURING
THE EVENING AND OVERNIGHT HOURS. ANY SNOW ACCUMULATIONS SHOULD BE
CONFINED TO GRASSY SURFACES...AND RANGE FROM A TRACE TO A HALF INCH.
MEANWHILE A STRONGER NORTHERN STREAM SHORTWAVE WILL MOVE ACROSS
SOUTHERN CANADA AND DRIVE A COLD FRONT THROUGH THE DAKOTAS INTO
NORTHWEST MN. A BAND OF POST FRONTAL SNOW WILL GIVE A QUICK 2-3
INCHES OF SNOW UP THERE...BUT THIS WILL WEAKEN AS IT APPROACHES WEST
CENTRAL MN. THEREFORE JUST HAVE CHANCE POPS IN...WITH LITTLE IF ANY
ACCUMULATION. THE MOST NOTICEABLE CHANGE IN THE WEATHER WILL BE
STRONG OVERNIGHT NORTHWEST WINDS OF 25MPH...WITH GUSTS NEAR 35MPH
ASSOCIATED WITH THE COLD AIR ADVECTION BEHIND THE SURFACE FRONT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM CST WED NOV 20 2013
THE BIG WEATHER STORY OVER THE COMING DAYS IS THE SNOW EVENT
EXPECTED THURSDAY AFTERNOON - THURSDAY NIGHT. THE FEATURE EXPECTED
TO BRING MN/WI SNOW THIS WEEK IS CURRENTLY LOCATED IN THE PACIFIC
NORTHWEST AND NORTHERN ROCKIES THIS MORNING...BUT REALLY DOESN`T
SHOW MUCH AMPLIFICATION THIS MORNING. HOWEVER...THERE IS A WELL
DEFINED ARCTIC BOUNDARY NEAR THE US/CANADIAN BORDER IN
MT/ND...WITH COLD AIR ALREADY SPILLING ACROSS THE BORDER. THIS
WAVE WILL DROP SOUTHEAST OVER THE NEXT COUPLE DAYS...BECOME A
LITTLE SHARPER/WELL-DEFINED AND PASS THROUGH THE FORECAST AREA
BETWEEN 21Z THURSDAY AND 12Z FRIDAY. A SW/NE ORIENTATED BAND OF
600-700MB FGEN WILL SWING THROUGH THE FORECAST THIS AREA DURING
THIS TIME...YIELDING A 3-6 HR WINDOW WITH LIGHT TO MODERATE SNOW.
THE 20.00-06Z NAM HAVE A SHARPER WAVE AND STRONGER FGEN. AS A
RESULT...THE NAM HAS HIGHER TOTALS ACROSS A LARGER PORTION OF THE
FORECAST AREA /A LOT OF 3-4" TOTALS/. THE GEM/GFS/ECMWF ARE A
LITTLE MORE DIFFUSE WITH THE BOUNDARY AND HAVE THE HIGHER TOTALS
/2-3"/ ACROSS MAINLY SOUTH CENTRAL MN. THE LAST 3 RUNS OF THE SREF
HAVE MAINTAINED AROUND 1" FOR MSP...THE NAM HAS SHOWN
1-3.5"...OVER THE LAST FEW RUNS...AND THE GFS HAS BEEN THE
STEADIEST WITH RIGHT AROUND 2". THE QPF ISN`T OVERLY IMPRESSIVE
/NOT SURPRISING GIVEN THIS IS A NORTHWEST FLOW EVENT/ BUT THE SNOW
RATIOS SHOULD EXCEED 12:1 GIVEN THE COLD PROFILE. HOWEVER...THE
COMBINATION OF STRONG SURFACE WINDS AND UNCERTAINTY IN OVERLAP OF
BEST OMEGA AND THE DENDRITE GROWTH ZONE SUGGESTS RATIOS SHOULD NOT
BE AS THEY COULD BE...PERHAPS 13-15:1. WE HAVE TRACE AMOUNTS IN
THE NORTHERN FORECAST AREA OF CENTRAL MN TO AROUND 3" IN OUR
SOUTH. AT THIS POINT...THE EVENT LOOKS JUST SHY OF NEEDING A
WINTER WEATHER ADVISORY...ESPECIALLY SINCE MOST OF THE ACTIVITY
WILL FALL BETWEEN THE EVENING AND MORNING COMMUTES.
NONETHELESS...THURSDAY NIGHT WILL FEEL MORE LIKE DECEMBER OR
JANUARY WITH FALLING TEMPS...BRISK NORTHERLY WINDS...AND BANDS OF
SNOW.
THE THURSDAY SYSTEM IS THE FIRST OF TWO ARCTIC BOUNDARIES EXPECTED
OVER THE NEXT 7 DAYS. THE WIND AND COLD TEMPS BEHIND THE THURSDAY
SYSTEM WILL DROP WIND CHILLS NEAR OR BELOW ZERO FOR MUCH OF THE
FORECAST AREA...FOR MOST OF THE WEEKEND. ANOTHER...POTENTIALLY
MORE POTENT /IN TERMS OF COLD/ ARCTIC BOUNDARY IS EXPECTED TO
ARRIVE ON TUESDAY. THIS WOULD BE THE COLDEST AIR OF THE SEASON IF
THE GFS/ECMWF PAN OUT. AS A RESULT...MINUS A BRIEF WARM UP ON
MONDAY...MN/WI WILL SEE HIGHS IN THE TEENS AND 20S AND LOWS IN THE
SINGLE DIGITS ABOVE OR BELOW ZERO FROM SATURDAY-WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 555 AM CST WED NOV 20 2013
SOUTHERLY WINDS WILL CONTINUE AHEAD OF AN APPROACHING COLD FRONT
THAT WILL MOVE THROUGH THE REGION LATER TONIGHT. BEHIND THE FRONT
EXPECT MVFR/IFR CIGS AND NORTHWEST WINDS OF GUSTING IN EXCESS OF
25KTS AT TIMES. MEANWHILE TODAY MOISTURE WILL SURGE UP FROM THE
SOUTH AND BRING SOME MVFR/IFR CONDITIONS ACROSS WESTERN MN...WHICH
WILL LINGER OVERNIGHT AT KEAU AND KRNH.
KMSP...
LATEST HIRES MODELS HAVE THE LOW CIGS JUST TO THE SOUTH AND EAST
OF THE METRO AREA THIS EVENING/OVERNIGHT...SO HAVE TRENDED IN THAT
DIRECTION. CONFIDENCE IS HIGHER IN MVFR CIGS THURSDAY MORNING AS
THE COLD FRONT MOVES IN FROM THE NORTHWEST.
/OUTLOOK FOR KMSP/
THU...VFR WITH MVFR/IFR AND -SN LATE. WINDS NNW AT 15G20KTS.
FRI...MVFR/IFR AND -SN ENDING. THEN VFR. WINDS NNW AT 10KTS.
SAT...VFR/MVFR. WINDS NW AT 15G25KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...CLF
AVIATION...JRB
AREA FORECAST DISCUSSION
NWS DULUTH MN
550 AM CST WED NOV 20 2013
.SHORT TERM...(TODAY THROUGH THURSDAY AFTERNOON)
ISSUED AT 345 AM CST WED NOV 20 2013
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE RAIN/SNOW MIX
EXPECTED TO DEVELOP LATE THIS MORNING AND CONTINUE THROUGH THE
AFTERNOON AND EVENING MAINLY ACROSS NW WI EVENTUALLY SPREADING
WWD INTO EXTREME E-CENTRAL/NE MN...AND THE COLD FRONT CURRENTLY
OVER ERN ND EXPECTED TO PUSH EWD THROUGH THE NORTHLAND TONIGHT AND
EARLY THURSDAY WITH SCATTERED SNOW SHOWERS AND GUSTY N/NW WINDS
AND FALLING TEMPERATURES THROUGH THUR AFTERNOON. THE OTHER AREA OF
CONCERN WILL BE THE LAKE EFFECT SNOW POTENTIAL ALONG THE SOUTH
SHORE THUR AFTERNOON. FAVORABLE CONDITIONS WILL ALLOW FOR
ACCUMULATING LES TO INITIATE AND CONTINUE THROUGH THE NIGHT.
WEAK UPPER TROUGH CURRENTLY SITUATED OVER THE WRN US WITH A LOW
AMPLITUDE RIDGE ACROSS THE ERN GREAT LAKES/NERN US. AT THE
SFC...HIGH PRESSURE IS DOMINATING THE CNTRL GRT LKS AND AN AREA OF
LOW PRESSURE IS DEVELOPING OVER THE FRONT RANGE OF THE ROCKIES.
THIS SET UP IS PRODUCING A TIGHT PRESSURE GRADIENT ACROSS THE
UPPER MIDWEST AND FAVORABLE CONDITIONS FOR STRONG SLY FLOW AND
GUSTY WINDS. THIS WARM FLOW HAS ALLOW TEMPERATURES TO REMAIN MILD
THIS MORNING...WITH TEMPS FROM THE MID 30S TO LOWER 40S.
A WEAK S/W WILL EJECT NEWD OUT OF THE SRN ROCKIES/PLAINS THIS
MORNING AND WILL TRACK FROM OKLA TO THE MICH U.P. TODAY AND TONIGHT.
THIS SYSTEM WILL INTERACT WITH THE RELATIVELY WARM AND MOIST AIR
MASS IN PLACE TO PRODUCE MAINLY A RAIN/SNOW MIX OVER THE ERN HALF OF
THE NORTHLAND. TEMP PROFILES IN THE MID LEVELS WILL HOVER AROUND OR
JUST BELOW FREEZING...WITH SFC TEMPS A FEW DEG ABOVE 32F. THIS
SET UP SHOULD BE CONDUCIVE FOR A RA/SN MIX. A FEW OF THESE SHOWERS
COULD BECOME ENHANCED AS THE THERMAL GRADIENT TIGHTENS THIS
AFTERNOON/EVENING WITH THE APPROACH OF A STRONG COLD FRONT FROM THE
WEST. THE STRONG MOISTURE CONTENT AND POTENTIALLY INTENSIFYING
SHOWERS MIGHT ALLOW THE PRECIP TO CHANGE OVER TO ALL SNOW IN SOME
LOCATIONS. HOWEVER...WILL BE DIFFICULT TO NAIL DOWN THESE SMALL
SCALE DETAILS.
TONIGHT AND MAINLY TOMORROW THE MAIN AREA OF CONCERN SHIFTS TO THE
APPROACHING COLD FRONT. THE FRONT IS EXPECTED TO TRACK FAIRLY SLOWLY
EWD THROUGH NRN MN LATE TONIGHT AND THROUGH THUR MORNING AS THE S/W
TO THE EAST LIFTS INTO THE GRT LKS. THE COLD FRONT WILL HAVE AN
ARCTIC AIR MASS BEHIND IT AND USHER IN SNOW SHOWERS OVER MUCH OF THE
NORTHLAND. THE SNOW WILL BE FAIRLY WIDESPREAD DURING THE DAY
THURSDAY...BUT ONLY LIGHT AMTS ARE EXPECTED WITH DRY AIR MOVING
IN BEHIND THE FRONT. HIGH PRESSURE WILL BUILD IN OVER THE
DAKOTAS...NW MN...AND WRN ONTARIO THUR AFTERNOON AND ALLOW WINDS
TO SHIFT TO THE NORTH AND BECOME QUITE GUSTY. THE COLD TEMPS AND
STRONG WINDS WILL MAKE CONDITIONS FEEL VERY COLD. HIGHS WILL LEVEL
OUT IN THE TEENS TO THE NORTH AND LOW 30S TO THE SOUTH...WITH
STEADY OR FALLING TEMPS FROM WEST TO EAST THROUGH THE DAY.
THE COLD AIR MASS MOVING IN AND VEERING NORTH WINDS OVER WRN LAKE
SUPERIOR WILL PRODUCE FAVORABLE CONDITIONS FOR LAKE EFFECT SNOW
ALONG THE SOUTH SHORE BEGINNING THUR AFTERNOON. BL MOISTURE PROFILES
WILL BE HIGH ENOUGH DURING THE AFTERNOON TO ALLOW THE LES TO
INITIATE BEFORE THE DRIER AIR MOVES IN. STEEP LOW LVL LAPSE RATES
AND WEAK INSTABILITY WITH A LONG FETCH OVER LS WILL ALL AID IN THE
DEVELOPMENT OF SNOW SHOWERS OVER BAYFIELD ASHLAND AND IRON
COUNTIES. COULD SEE AN INCH OR SO OF ACCUMULATION BEFORE 6 PM
THURSDAY...AFTER WHICH ADDITIONAL SNOW IS LIKELY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 345 AM CST WED NOV 20 2013
THE EXTENDED PERIOD WILL FEATURE SOME VERY COLD AIR MOVING OVER THE
NORTHLAND FRIDAY INTO FRIDAY NIGHT AND PERIODS OF LAKE EFFECT SNOW.
A COLD FRONT WILL MOVE THROUGH THE REGION THURSDAY. THURSDAY
NIGHT...A MID LEVEL FRONT AND FGEN WILL BRING A CHANCE FOR SNOW TO
ABOUT THE SOUTHERN HALF OF THE NORTHLAND...WITH CHANCES HIGHEST OVER
NORTHWEST WISCONSIN. SOME LIGHT SNOWFALL...UP TO 2 INCHES IN
SPOTS...WILL BE POSSIBLE. THE EXCEPTION WILL BE THE SNOWBELT OF
ASHLAND AND IRON COUNTIES WHICH SHOULD SEE HIGHER SNOWFALL DUE TO
NORTHERLY WINDS DEVELOPING AND THE STABILITY BEING LOW ENOUGH FOR
LAKE EFFECT SNOW.
ANOTHER SHORTWAVE AND STRONGER COLD FRONT WILL SWEEP THROUGH THE
AREA FRIDAY INTO FRIDAY NIGHT. THE FRONT WILL BRING A CHANCE FOR
LIGHT SNOW...WITH LIMITED SNOW ACCUMULATIONS EXPECTED. AT THIS
TIME...WE THINK A NARROW BAND OF STRONGER FAST MOVING SNOW SHOWERS
WILL BE POSSIBLE WITH THE FRONT. 850MB TEMPS ARE FORECAST TO DROP TO
-23C FAR NORTH TO -19C IN OUR SOUTHERN ZONES BY 12Z SAT. WE ARE
EXPECTING LOWS SATURDAY MORNING TO BE AROUND ZERO NORTH TO 10 TO 15
ACROSS NORTHERN WISCONSIN. TEMPS COULD BE EVEN COLDER IF WINDS CAN
DROP OFF MORE THAN IS EXPECTED ATTM. HIGHS SATURDAY WILL ONLY REACH
AROUND 10 ABOVE ACROSS FAR NORTHERN MINNESOTA...TO THE TEENS SOUTH.
THE LAKE WILL BECOME ACTIVE AGAIN FRIDAY NIGHT INTO SATURDAY
NIGHT...WITH SOME SIGNIFICANT SNOWFALL LIKELY ACROSS THE SNOWBELT OF
ASHLAND AND IRON COUNTIES WITH THE VERY COLD TEMPS CROSSING THE LAKE
WITH A FAVORABLE FETCH.
WAA WILL DEVELOP SATURDAY NIGHT INTO SUNDAY...WITH SOME LIGHT SNOW
POSSIBLE ACROSS THE REGION. ANOTHER STRONG COLD FRONT WILL THEN
SWEEP THROUGH THE REGION MONDAY INTO MONDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 550 AM CST WED NOV 20 2013
VFR CONDITIONS COVERED THE NORTHLAND EARLY THIS MORNING. A LLJ
REMAINED OVER MUCH OF THE NORTHLAND CREATING SOME LLWS THAT WILL
CONTINUE EARLY THIS MORNING.
A COLD FRONT IN NORTHWEST MINNESOTA WILL CONTINUE TO SLOWLY MOVE
SOUTHEAST TODAY. MVFR CEILINGS WILL MOVE IN FROM THE
NORTHWEST...AND WERE SEEN IN OBSERVATIONS/SATELLITE OVER PORTIONS
OF MB/OT. THE RAP WAS HANDLING THESE CLOUDS FAIRLY WELL. MORE MVFR
OR LOW END VFR CLOUDS ARE EXPECTED TO DEVELOP AND MOVE NORTH
TOWARD NORTHERN WISCONSIN THIS AFTERNOON. MVFR OR IFR CEILINGS ARE
EXPECTED OVER ALL AREAS TONIGHT. SOME LIGHT PRECIPITATION WILL
DEVELOP AS WELL TODAY...BOTH BEHIND THE COLD FRONT...AND WELL
AHEAD OVER NORTHERN WISCONSIN/FAR EASTERN MINNESOTA LATER THIS
AFTERNOON. THE PRECIPITATION MAY START OUT AS RAIN...OR A
MIX...BUT WILL TRANSITION TO MAINLY SNOW TONIGHT. SOUNDINGS ALSO
SUGGEST SOME DRYING ALOFT LATER TONIGHT WHICH COULD LEAD TO
DRIZZLE AS WE LOSE ICE IN THE CLOUDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 42 26 27 14 / 30 30 30 30
INL 38 16 19 5 / 20 60 30 10
BRD 45 22 25 13 / 10 20 20 20
HYR 41 30 30 19 / 40 50 40 60
ASX 43 32 32 20 / 30 50 60 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ121-
142-143-146>148.
SMALL CRAFT ADVISORY UNTIL 10 AM CST THIS MORNING FOR LSZ144-145.
SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ140-141.
&&
$$
SHORT TERM...BJT
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
425 AM CST WED NOV 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST WED NOV 20 2013
EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH GFS20.00 500MB
HEIGHTS AND WINDS SHOWS SPLIT FLOW ACROSS NORTH AMERICA...WITH THE
NORTHERN STREAM SET UP ACROSS SOUTHERN CANADA...WHILE THE ZONAL
SOUTHERN STREAM WAS POSITIONED FROM SOUTHERN CALIFORNIA TO GEORGIA.
A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE CURRENTLY LOCATED ACROSS
EASTERN COLORADO WILL TRACK NORTHEASTWARD TODAY...AND THIS WILL
PROVIDE THE LARGE SCALE FORCING FOR A FEW LIGHT RAIN/SNOW SHOWERS IN
WESTERN WISCONSIN AND FAR EASTERN MINNESOTA. RAP FORECAST SOUNDINGS
FOR EAU CLAIRE SHOW AROUND 15UB/S OF LIFT CENTERED AROUND THE 600MB
LAYER..WITH AN ISOTHERMAL LAYER IN THE LOWEST 4000FT HOVERING AROUND
0C. THE WARM NEAR SURFACE TEMPERATURES SHOULD MELT THE PRECIP DURING
THE AFTERNOON...BUT EXPECT A TRANSITION TO A RAIN/SNOW MIX DURING
THE EVENING AND OVERNIGHT HOURS. ANY SNOW ACCUMULATIONS SHOULD BE
CONFINED TO GRASSY SURFACES...AND RANGE FROM A TRACE TO A HALF INCH.
MEANWHILE A STRONGER NORTHERN STREAM SHORTWAVE WILL MOVE ACROSS
SOUTHERN CANADA AND DRIVE A COLD FRONT THROUGH THE DAKOTAS INTO
NORTHWEST MN. A BAND OF POST FRONTAL SNOW WILL GIVE A QUICK 2-3
INCHES OF SNOW UP THERE...BUT THIS WILL WEAKEN AS IT APPROACHES WEST
CENTRAL MN. THEREFORE JUST HAVE CHANCE POPS IN...WITH LITTLE IF ANY
ACCUMULATION. THE MOST NOTICEABLE CHANGE IN THE WEATHER WILL BE
STRONG OVERNIGHT NORTHWEST WINDS OF 25MPH...WITH GUSTS NEAR 35MPH
ASSOCIATED WITH THE COLD AIR ADVECTION BEHIND THE SURFACE FRONT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM CST WED NOV 20 2013
THE BIG WEATHER STORY OVER THE COMING DAYS IS THE SNOW EVENT
EXPECTED THURSDAY AFTERNOON - THURSDAY NIGHT. THE FEATURE EXPECTED
TO BRING MN/WI SNOW THIS WEEK IS CURRENTLY LOCATED IN THE PACIFIC
NORTHWEST AND NORTHERN ROCKIES THIS MORNING...BUT REALLY DOESN`T
SHOW MUCH AMPLIFICATION THIS MORNING. HOWEVER...THERE IS A WELL
DEFINED ARCTIC BOUNDARY NEAR THE US/CANADIAN BORDER IN
MT/ND...WITH COLD AIR ALREADY SPILLING ACROSS THE BORDER. THIS
WAVE WILL DROP SOUTHEAST OVER THE NEXT COUPLE DAYS...BECOME A
LITTLE SHARPER/WELL-DEFINED AND PASS THROUGH THE FORECAST AREA
BETWEEN 21Z THURSDAY AND 12Z FRIDAY. A SW/NE ORIENTATED BAND OF
600-700MB FGEN WILL SWING THROUGH THE FORECAST THIS AREA DURING
THIS TIME...YIELDING A 3-6 HR WINDOW WITH LIGHT TO MODERATE SNOW.
THE 20.00-06Z NAM HAVE A SHARPER WAVE AND STRONGER FGEN. AS A
RESULT...THE NAM HAS HIGHER TOTALS ACROSS A LARGER PORTION OF THE
FORECAST AREA /A LOT OF 3-4" TOTALS/. THE GEM/GFS/ECMWF ARE A
LITTLE MORE DIFFUSE WITH THE BOUNDARY AND HAVE THE HIGHER TOTALS
/2-3"/ ACROSS MAINLY SOUTH CENTRAL MN. THE LAST 3 RUNS OF THE SREF
HAVE MAINTAINED AROUND 1" FOR MSP...THE NAM HAS SHOWN
1-3.5"...OVER THE LAST FEW RUNS...AND THE GFS HAS BEEN THE
STEADIEST WITH RIGHT AROUND 2". THE QPF ISN`T OVERLY IMPRESSIVE
/NOT SURPRISING GIVEN THIS IS A NORTHWEST FLOW EVENT/ BUT THE SNOW
RATIOS SHOULD EXCEED 12:1 GIVEN THE COLD PROFILE. HOWEVER...THE
COMBINATION OF STRONG SURFACE WINDS AND UNCERTAINTY IN OVERLAP OF
BEST OMEGA AND THE DENDRITE GROWTH ZONE SUGGESTS RATIOS SHOULD NOT
BE AS THEY COULD BE...PERHAPS 13-15:1. WE HAVE TRACE AMOUNTS IN
THE NORTHERN FORECAST AREA OF CENTRAL MN TO AROUND 3" IN OUR
SOUTH. AT THIS POINT...THE EVENT LOOKS JUST SHY OF NEEDING A
WINTER WEATHER ADVISORY...ESPECIALLY SINCE MOST OF THE ACTIVITY
WILL FALL BETWEEN THE EVENING AND MORNING COMMUTES.
NONETHELESS...THURSDAY NIGHT WILL FEEL MORE LIKE DECEMBER OR
JANUARY WITH FALLING TEMPS...BRISK NORTHERLY WINDS...AND BANDS OF
SNOW.
THE THURSDAY SYSTEM IS THE FIRST OF TWO ARCTIC BOUNDARIES EXPECTED
OVER THE NEXT 7 DAYS. THE WIND AND COLD TEMPS BEHIND THE THURSDAY
SYSTEM WILL DROP WIND CHILLS NEAR OR BELOW ZERO FOR MUCH OF THE
FORECAST AREA...FOR MOST OF THE WEEKEND. ANOTHER...POTENTIALLY
MORE POTENT /IN TERMS OF COLD/ ARCTIC BOUNDARY IS EXPECTED TO
ARRIVE ON TUESDAY. THIS WOULD BE THE COLDEST AIR OF THE SEASON IF
THE GFS/ECMWF PAN OUT. AS A RESULT...MINUS A BRIEF WARM UP ON
MONDAY...MN/WI WILL SEE HIGHS IN THE TEENS AND 20S AND LOWS IN THE
SINGLE DIGITS ABOVE OR BELOW ZERO FROM SATURDAY-WEDNESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1133 PM CST TUE NOV 19 2013
THE BIGGEST UNCERTAINTY FOR THE TAF PERIOD WILL BE THE ARRIVAL OF
LOWER CIGS LATER WEDNESDAY. A SLUG OF MOISTURE WILL DEVELOP OVER
THE MID MISSOURI VALLEY AND TRACK NORTHEAST INTO WISCONSIN
WEDNESDAY AFTERNOON. A FEW SHOWERS MAY IMPACT EAU DURING THIS TIME
ALONG WITH SOME MVFR CIGS. THE COLD FRONT WILL SLOW A BIT DURING
THE DAY AS THIS DISTURBANCE RIDES NORTHEAST IN ADVANCE OF IT.
BEHIND THE FRONT...THERE IS HIGH CONFIDENCE OF MVFR...POSSIBLY IFR
CIGS PERSISTING INTO WEDNESDAY NIGHT. WHERE THE UNCERTAINTY
RESIDES IS BETWEEN THESE TWO FEATURES - THE FRONT AND THE
DISTURBANCE. MODELS ARE CURRENTLY ALL OVER THE PLACE WITH LOW
LEVEL MOISTURE CONTENT AND THUS TIMING OF LOWER CIGS MAY CHANGE IN
FUTURE FORECASTS. IN THE MEANTIME...VFR CONDITIONS EXPECTED WITH
WIND SHEAR DIMINISHING OVERNIGHT.
KMSP...VFR CONDITIONS EXPECTED INTO EARLY WEDNESDAY AFTERNOON.
THEREAFTER...UNCERTAINTY IS RELATIVELY HIGH WITH REGARDS TO TIMING
OF LOWER CIGS AS OUTLINED ABOVE. THINK PRECIPITATION WILL REMAIN
WELL EAST OF MSP WEDNESDAY AFTERNOON.
/OUTLOOK FOR KMSP/
THU...VFR. N WIND 12-15 KTS.
THU NGT...MVFR/SN LIKELY. NE WIND 10 KTS.
FRI...VFR. MVFR POSSIBLE FRIDAY NIGHT. N TO NW WIND 5-10 KTS.
SAT...MVFR POSSIBLE. NW WIND 15G25KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
SHORT TERM...JRB
LONG TERM...CLF
AVIATION...BORGHOFF
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
524 AM CST Wed Nov 20 2013
...Aviation Forecast Update...
.SHORT TERM...(Today and Tonight)
Issued at 304 AM CST WED NOV 20 2013
Currently...as expected, isentropic upglide is underway in the
300-310K layer with a solid pressure advection signal. Regional
radar has seen a gradual increase in showers and even a few
lightning strikes. MUCAPE according to the short range models is
in the 100-200 J/kg range (slightly higher to the west over KS/OK)
and supports at least a slight chance mention for thunder for the
remainder of this morning.
Could see varying precip types this morning given the very dry low
levels. The 00z soundings from KSGF/KLZK/KSHV all show a very
stout low level dry layer. RUC initializations from 07z still
indicating dewpoint depressions around 900mb in the 30-50 C range!
With a southeast downsloping wind, dewpoints are struggling at the
surface, dropping into the teens in many locations, especially
northwest of the plateau and ahead of the incoming radar echoes.
Precip falling from these echoes is likely falling as (mainly)
rain, but cannot rule out some poor man`s sleet mixing in given a
6000 foot layer of wet bulb temperatures aloft at or just below 0C.
With a little bit of elevated instability, cannot argue with very
small hail with any storms.
The short wave responsible for instigating this activity will move
from the central Plains and toward the Great Lakes region through
the day. The area will remain in the left exit region of an upper
jet most of the morning, so there will be broad scale lift
support. In the mid to lower levels, isentropic upglide/pressure
advection will continue in the 300-310K layer this morning,
shunting to the northeast into northern Missouri during the
afternoon hours. Will maintain scattered to numerous shower
wording this morning with a mention of sleet possibly mixing in
from time to time through the mid morning hours. During the
afternoon, have lowered PoPs a bit and changed to chance wording
as most of the shower activity should be exiting into central and
northern Missouri.
There will likely be a brief lull in the rainfall from late this
afternoon into the early evening. However, the next shortwave will
be ready to move into the region during the overnight hours. Have
ramped up PoPs during the overnight hours as showers and a few
embedded thunderstorms should envelope the area from southwest to
northeast.
Temperatures will be a challenge today given wet bulbing,
scattered showers and cloud cover. Have held close to a consensus
of the MOS and raw models, which keep readings mainly in the 50-55
degree range (slightly warmer across far southwestern MO).
.LONG TERM...(Thursday through Tuesday)
Issued at 304 AM CST WED NOV 20 2013
Periods of rain are expected on Thursday across the entire outlook
area. NAM/GFS continue to suffer from convective feedback, though
it is indicative of locally heavy rainfall potential. This heavier
rainfall will likely occur in a narrow, mesoscale band, almost
impossible to pin point. Yet another shortwave will move into the
region later Thursday night into early Friday resulting in yet
more periods of rainfall. By Thursday night, model consensus
indicates that a cold front and shallow low level cold airmass
will begin moving into the region, spreading across the entire
area Friday morning. At this point, thermal profiles from all
models support a wet forecast, rather than wintry. We will have
to keep a very sharp eye on this airmass intrusion, especially
across the northwest third of the CWA.
Some good news is that the global models continue to indicate a
progressive invasion of colder and drier air for Friday night.
Have lowered PoPs a bit more and if present trends continue,
Friday night may only feature a few lingering light rain showers
or flurries. Storm total rainfall accumulation for this event
continues to suggest a widespread 0.50" to 2.00" with a mesoscale
band of locally higher amounts possible.
The weekend will be cold and mostly dry as a 1050mb surface high
pressure settles down from southern Canada into the Midwest
region. The center of the high will be near the Missouri Ozarks
area Saturday night into Sunday morning. This will be the coldest
night with clear skies and light winds...temperatures will be
likely in the middle to upper teens. High temperatures this
weekend will be only in the 30s despite sunshine.
The next big question will be what does the cut off low over the
southwest U.S. do for the early part of next week and how much
cold air will be around when this system moves out into the
southern Plains region.
The latest runs of the GFS..ECMWF...GEM...indicate this system
will affect the area by Monday morning. There is still some
disagreement on track and timing but the consensus is that precip
may begin to develop late Sunday night into Monday morning and
spread into the area. It does appear at this time that light
wintry weather mainly in the form of light snow will be possible.
The ECMWF and GEM are the most bullish with the QPF. With
temperatures not climbing much on Monday...there will be a
rain/snow mix possible and lingering through Monday night. Will
need to monitor future trends with model data but the Monday
morning commute could be tricky with light snow in the area but
amounts appear light at this time up to an inch possible. Below
average temperatures will continue through middle of next week
with another surge of cold air moving in.
&&
.AVIATION...(For the 12Z TAFS through 12Z Thursday Morning)
Issued at 509 AM CST WED NOV 20 2013
Scattered showers will be around through mid morning but mainly
VFR conditions will prevail. Winds will remain gusty out of the
southeast especially for SGF up to 25 knots. A broken to overcast deck
will remain through the afternoon around 10k feet. The next round
of showers will be developing after 00z tonight with showers
likely at all terminals by 06z. Have included low level wind shear
through 16z this morning at all terminals and again after 00z
tonight.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
SHORT TERM...Gagan
LONG TERM...Gagan/Griffin
AVIATION...Griffin
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
540 PM EST WED NOV 20 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 207 PM EST WED NOV 20 2013
HIGH PRESSURE TO THE EAST IS GOING TO RULE INDIANA WEATHER
OVERNIGHT. FROM THURSDAY INTO FRIDAY A COMBINED LOW PRESSURE SYSTEM
AND COLD FRONT SHOULD CROSS THE HOOSIER STATE FROM THE WEST. THE LOW
PRESSURE SYSTEM AND COLD FRONT WILL BE FOLLOWED BY A HUGE AREA OF
HIGH PRESSURE.
THE HIGH PRESSURE AREA IS FORECAST TO BE FOLLOWED BY ANOTHER
COMBINED LOW PRESSURE SYSTEM AND COLD FRONT. EXPECT MORE HIGH
PRESSURE TO ARRIVE ACROSS INDIANA BY WEDNESDAY.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 207 PM EST WED NOV 20 2013
PROBLEM IS WHETHER RAIN WILL START LATE TONIGHT.
MODELS CONCUR WARM ADVECTION CAUSING INCREASING CLOUDS AND
SATURATION TONIGHT. RACE WILL BE ON FOR WHICH HAPPENS FIRST...WATER
MAKING IT TO GROUND OR 12Z ARRIVING.
THE MAV IS HIGH WITH POPS COMPARED TO THE MET. LAST TIME
PRECIPITATION MOVED INTO STATE MET TIMING WAS BETTER. LATEST RAP IN
BUFKIT HAS LITTLE OR NO QPF IN CWA THROUGH 10Z. THAT DOES NOT LEAVE
MUCH OF A WINDOW FOR ANYTHING TO START BEFORE THURSDAY. GOING MET
PLUS 10 PERCENT...SO AS TO NOT COMPLETELY DISCOUNT MAV.
VERY LOW CONFIDENCE TEMPERATURE FORECAST. MINOR CHANGES IN
CLOUDS OR PCPN WOULD HAVE A BIG IMPACT. FOR NOW USING
GUIDANCE...WHICH IS ALMOST THE SAME BETWEEN MODELS. EVENING SHIFT
MAY BE ABLE TO MAKE SIGNIFICANT IMPROVEMENTS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 207 PM EST WED NOV 20 2013
WITH MODELS AGREEING ABOUT WET THURSDAY AND THURSDAY NIGHT...MAIN
QUESTION IS WHEN RAIN WILL END.
FOR SOME REASON MAV POPS DROP SHARPLY FRIDAY. THIS MAKES NO SENSE
LOOKING AT ANY MODEL QPF. IT IS ALSO VERY DIFFERENT FROM EITHER THE
ECM OR NAM GUIDANCE. MAV HAD A SIMILAR PROBLEM DROPPING POPS FOR NO
APPARENT REASON WITH LAST SYSTEM. WILL USE THE MET.
GOING TO SLIGHTLY DAMPER MAV POPS FRIDAY NIGHT. PCPN WILL DEFINITELY
BE ON DOWNSWING. HOWEVER THAT FAR OUT I DONT WANT TO COMPLETELY RULE
OUT SOMETHING PAST 00Z. EVERYTHING POINTS TO CLEARING SATURDAY.
TEMPERATURES...GREAT UNCERTAINTY. THEY WILL BE HEAVILY IMPACTED BY
DETAILS IN TIMING OF PRECIPITATION...CLOUDS...AND A FRONTAL PASSAGE.
CONSENSUS BEST FOR SITUATIONS LIKE THIS. WILL TRY THAT BETWEEN MAV
AND MET. SIGNIFICANT FORECAST CHANGES MAY OCCUR AS NEW INFO ARRIVES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 236 PM EST WED NOV 20 2013
BOTH THE EURO AND GFS ARE IN GOOD AGREEMENT WITH SPLIT FLOW ACROSS
THE U.S. AS MID/UPPER LEVEL FLOW WILL COME FROM THE NORTHERN
CANADIAN TERRITORIES SOUTHEAST INTO THE UPPER OHIO VALLEY DUE TO A
MID/UPPER LOW BLOCKING OVER THE SOUTHWESTERN U.S. THIS LEAVES AREAS
FROM THE UPPER GREAT LAKES AND OHIO VALLEY IN COLD AIR REGIME
THROUGH THE PERIOD. TEMPERATURES WILL BE IN THE 30S FOR HIGHS AND IN
THE TEENS TO THE MID 20S FOR LOWS.
A TROUGH WILL BE EMBEDDED WITHIN THE MID LEVEL FLOW BRINGING
RAIN/SNOW EARLY ON DURING THE SHORTENED WORK WEEK AS TEMPERATURES
WILL BE WARM ENOUGH FOR RAIN/SNOW POSSIBLE STARTING ON MONDAY
BECOMING LIGHT SNOW MONDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR 210000Z TAF ISSUANCE/...
ISSUED AT 540 PM EST WED NOV 20 2013
VFR WITH SCATTERED LIGHT SHOWERS OVERNIGHT...GIVING WAY TO MVFR IN
RAIN DURING THE DAY THURSDAY.
SCATTERED LIGHT SHOWERS...MOST NUMEROUS AROUND KLAF...WILL CONTINUE
THIS EVENING. DO NOT THINK THERE WILL BE ANY RESTRICTIONS WITH THESE
SHOWERS...SO WILL COVER WITH VCSH AS NECESSARY. WINDS NOT FAR OFF
THE SURFACE WILL BE RELATIVELY STRONG OVERNIGHT...BUT NOT QUITE TO
LOW LEVEL WIND SHEAR CRITERIA.
RAIN WILL DEVELOP LATE TONIGHT NORTHWEST AND SLOWLY SPREAD SOUTHEAST
ACROSS THE TAF SITES ON THURSDAY. EXPECT CEILINGS AND VISIBILITIES
TO LOWER TO MVFR IN THE RAIN. CANNOT RULE OUT IFR BY THE END OF THE
PERIOD AT KLAF AND IN THE LATTER PART OF THE 30 HOUR TAF AT KIND.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....DWM
AVIATION...50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
352 PM EST WED NOV 20 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 207 PM EST WED NOV 20 2013
HIGH PRESSURE TO THE EAST IS GOING TO RULE INDIANA WEATHER
OVERNIGHT. FROM THURSDAY INTO FRIDAY A COMBINED LOW PRESSURE SYSTEM
AND COLD FRONT SHOULD CROSS THE HOOSIER STATE FROM THE WEST. THE LOW
PRESSURE SYSTEM AND COLD FRONT WILL BE FOLLOWED BY A HUGE AREA OF
HIGH PRESSURE.
THE HIGH PRESSURE AREA IS FORECAST TO BE FOLLOWED BY ANOTHER
COMBINED LOW PRESSURE SYSTEM AND COLD FRONT. EXPECT MORE HIGH
PRESSURE TO ARRIVE ACROSS INDIANA BY WEDNESDAY.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 207 PM EST WED NOV 20 2013
PROBLEM IS WHETHER RAIN WILL START LATE TONIGHT.
MODELS CONCUR WARM ADVECTION CAUSING INCREASING CLOUDS AND
SATURATION TONIGHT. RACE WILL BE ON FOR WHICH HAPPENS FIRST...WATER
MAKING IT TO GROUND OR 12Z ARRIVING.
THE MAV IS HIGH WITH POPS COMPARED TO THE MET. LAST TIME
PRECIPITATION MOVED INTO STATE MET TIMING WAS BETTER. LATEST RAP IN
BUFKIT HAS LITTLE OR NO QPF IN CWA THROUGH 10Z. THAT DOES NOT LEAVE
MUCH OF A WINDOW FOR ANYTHING TO START BEFORE THURSDAY. GOING MET
PLUS 10 PERCENT...SO AS TO NOT COMPLETELY DISCOUNT MAV.
VERY LOW CONFIDENCE TEMPERATURE FORECAST. MINOR CHANGES IN
CLOUDS OR PCPN WOULD HAVE A BIG IMPACT. FOR NOW USING
GUIDANCE...WHICH IS ALMOST THE SAME BETWEEN MODELS. EVENING SHIFT
MAY BE ABLE TO MAKE SIGNIFICANT IMPROVEMENTS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 207 PM EST WED NOV 20 2013
WITH MODELS AGREEING ABOUT WET THURSDAY AND THURSDAY NIGHT...MAIN
QUESTION IS WHEN RAIN WILL END.
FOR SOME REASON MAV POPS DROP SHARPLY FRIDAY. THIS MAKES NO SENSE
LOOKING AT ANY MODEL QPF. IT IS ALSO VERY DIFFERENT FROM EITHER THE
ECM OR NAM GUIDANCE. MAV HAD A SIMILAR PROBLEM DROPPING POPS FOR NO
APPARENT REASON WITH LAST SYSTEM. WILL USE THE MET.
GOING TO SLIGHTLY DAMPER MAV POPS FRIDAY NIGHT. PCPN WILL DEFINITELY
BE ON DOWNSWING. HOWEVER THAT FAR OUT I DONT WANT TO COMPLETELY RULE
OUT SOMETHING PAST 00Z. EVERYTHING POINTS TO CLEARING SATURDAY.
TEMPERATURES...GREAT UNCERTAINTY. THEY WILL BE HEAVILY IMPACTED BY
DETAILS IN TIMING OF PRECIPITATION...CLOUDS...AND A FRONTAL PASSAGE.
CONSENSUS BEST FOR SITUATIONS LIKE THIS. WILL TRY THAT BETWEEN MAV
AND MET. SIGNIFICANT FORECAST CHANGES MAY OCCUR AS NEW INFO ARRIVES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 236 PM EST WED NOV 20 2013
BOTH THE EURO AND GFS ARE IN GOOD AGREEMENT WITH SPLIT FLOW ACROSS
THE U.S. AS MID/UPPER LEVEL FLOW WILL COME FROM THE NORTHERN
CANADIAN TERRITORIES SOUTHEAST INTO THE UPPER OHIO VALLEY DUE TO A MID/UPPER
LOW BLOCKING OVER THE SOUTHWESTERN U.S. THIS LEAVES AREAS FROM THE
UPPER GREAT LAKES AND OHIO VALLEY IN COLD AIR REGIME THROUGH THE
PERIOD. TEMPERATURES WILL BE IN THE 30S FOR HIGHS AND IN THE TEENS
TO THE MID 20S FOR LOWS.
A TROUGH WILL BE EMBEDDED WITHIN THE MID LEVEL FLOW BRINGING
RAIN/SNOW EARLY ON DURING THE SHORTENED WORK WEEK AS TEMPERATURES
WILL BE WARM ENOUGH FOR RAIN/SNOW POSSIBLE STARTING ON MONDAY
BECOMING LIGHT SNOW MONDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR 202100Z TAF UPDATE/...
ISSUED AT 352 PM EST WED NOV 20 2013
KIND TAF LOOKS GOOD. ONLY MINOR TWEAKS MADE.
PREVIOUS DISCUSSION FOLLOWS...
VFR CONDITIONS IN PLACE FOR THIS AFTERNOON AND EARLY TONIGHT AS HIGH
PRESSURE WILL BE OVER THE EASTERN GREAT LAKES AND NEW ENGLAND.
THIS HIGH PRESSURE WILL MOVE MOVE OFF TO THE EAST AND NORTHEAST AS
LOW PRESSURE DEVELOPS OVER SOUTHEAST COLORADO TONIGHT AND A COLD FRONT
DRIFTS IN FROM THE NORTHWEST THURSDAY AFTERNOON. SOUTHERLY WINDS
WILL BRING MOISTURE NORTHWARD DURING THE EARLY HALF OF THURSDAY
AND WILL BE EXPECTING SOME LIGHT RAIN BY LATE MORNING BECOMING
MORE STEADY WITH MVFR/IFR CONDITIONS AT MOST TAF SITES BY THURSDAY
AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....DWM
AVIATION...DWM/50
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
252 PM EST WED NOV 20 2013
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 207 PM EST WED NOV 20 2013
HIGH PRESSURE TO THE EAST IS GOING TO RULE INDIANA WEATHER
OVERNIGHT. FROM THURSDAY INTO FRIDAY A COMBINED LOW PRESSURE SYSTEM
AND COLD FRONT SHOULD CROSS THE HOOSIER STATE FROM THE WEST. THE LOW
PRESSURE SYSTEM AND COLD FRONT WILL BE FOLLOWED BY A HUGE AREA OF
HIGH PRESSURE.
THE HIGH PRESSURE AREA IS FORECAST TO BE FOLLOWED BY ANOTHER
COMBINED LOW PRESSURE SYSTEM AND COLD FRONT. EXPECT MORE HIGH
PRESSURE TO ARRIVE ACROSS INDIANA BY WEDNESDAY.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 207 PM EST WED NOV 20 2013
PROBLEM IS WHETHER RAIN WILL START LATE TONIGHT.
MODELS CONCUR WARM ADVECTION CAUSING INCREASING CLOUDS AND
SATURATION TONIGHT. RACE WILL BE ON FOR WHICH HAPPENS FIRST...WATER
MAKING IT TO GROUND OR 12Z ARRIVING.
THE MAV IS HIGH WITH POPS COMPARED TO THE MET. LAST TIME
PRECIPITATION MOVED INTO STATE MET TIMING WAS BETTER. LATEST RAP IN
BUFKIT HAS LITTLE OR NO QPF IN CWA THROUGH 10Z. THAT DOES NOT LEAVE
MUCH OF A WINDOW FOR ANYTHING TO START BEFORE THURSDAY. GOING MET
PLUS 10 PERCENT...SO AS TO NOT COMPLETELY DISCOUNT MAV.
VERY LOW CONFIDENCE TEMPERATURE FORECAST. MINOR CHANGES IN
CLOUDS OR PCPN WOULD HAVE A BIG IMPACT. FOR NOW USING
GUIDANCE...WHICH IS ALMOST THE SAME BETWEEN MODELS. EVENING SHIFT
MAY BE ABLE TO MAKE SIGNIFICANT IMPROVEMENTS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 207 PM EST WED NOV 20 2013
WITH MODELS AGREEING ABOUT WET THURSDAY AND THURSDAY NIGHT...MAIN
QUESTION IS WHEN RAIN WILL END.
FOR SOME REASON MAV POPS DROP SHARPLY FRIDAY. THIS MAKES NO SENSE
LOOKING AT ANY MODEL QPF. IT IS ALSO VERY DIFFERENT FROM EITHER THE
ECM OR NAM GUIDANCE. MAV HAD A SIMILAR PROBLEM DROPPING POPS FOR NO
APPARENT REASON WITH LAST SYSTEM. WILL USE THE MET.
GOING TO SLIGHTLY DAMPER MAV POPS FRIDAY NIGHT. PCPN WILL DEFINITELY
BE ON DOWNSWING. HOWEVER THAT FAR OUT I DONT WANT TO COMPLETELY RULE
OUT SOMETHING PAST 00Z. EVERYTHING POINTS TO CLEARING SATURDAY.
TEMPERATURES...GREAT UNCERTAINTY. THEY WILL BE HEAVILY IMPACTED BY
DETAILS IN TIMING OF PRECIPITATION...CLOUDS...AND A FRONTAL PASSAGE.
CONSENSUS BEST FOR SITUATIONS LIKE THIS. WILL TRY THAT BETWEEN MAV
AND MET. SIGNIFICANT FORECAST CHANGES MAY OCCUR AS NEW INFO ARRIVES.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
ISSUED AT 236 PM EST WED NOV 20 2013
BOTH THE EURO AND GFS ARE IN GOOD ARGEEMENT WITH SPLIT FLOW ACROSS
THE U.S. AS MID/UPPER LEVEL FLOW WILL COME FROM THE NORTHERN
CANADIAN TERRITORIES SOUTHEAST INTO THE UPPER OHIO VALLEY DUE TO A MID/UPPER
LOW BLOCKING OVER THE SOUTHWESTERN U.S. THIS LEAVES AREAS FROM THE
UPPER GREAT LAKES AND OHIO VALLEY IN COLD AIR REGIME THROUGH THE
PERIOD. TEMPERATURES WILL BE IN THE 30S FOR HIGHS AND IN THE TEENS
TO THE MID 20S FOR LOWS.
A TROUGH WILL BE EMBEDDED WITHIN THE MID LEVEL FLOW BRINGING
RAIN/SNOW EARLY ON DURING THE SHORTENED WORK WEEK AS TEMPERATURES
WILL BE WARM ENOUGH FOR RAIN/SNOW POSSIBLE STARTING ON MONDAY
BECOMING LIGHT SNOW MONDAY NIGHT.
&&
.AVIATION /DISCUSSION FOR 201800Z TAF ISSUANCE/...
ISSUED AT 1153 AM EST WED NOV 20 2013
VFR CONDITIONS IN PLACE FOR THIS AFTERNOON AND EARLY TONIGHT AS
HIGH PRESSURE WILL BE OVER THE EASTERN GREAT LAKES AND NEW
ENGLAND.
THIS HIGH PRESSURE WILL MOVE MOVE OFF TO THE EAST AND NORTHEAST AS
LOW PRESSURE DEVELOPS OVER SOUTHEAST COLORADO TONIGHT AND A COLD FRONT
DRIFTS IN FROM THE NORTHWEST THURSDAY AFTERNOON. SOUTHERLY WINDS
WILL BRING MOISTURE NORTHWARD DURING THE EARLY HALF OF THURSDAY
AND WILL BE EXPECTING SOME LIGHT RAIN BY LATE MORNING BECOMING
MORE STEADY WITH MVFR/IFR CONDITIONS AT MOST TAF SITES BY THURSDAY
AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....DWM
AVIATION...DWM
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
207 PM EST WED NOV 20 2013
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 207 PM EST WED NOV 20 2013
HIGH PRESSURE TO THE EAST IS GOING TO RULE INDIANA WEATHER
OVERNIGHT. FROM THURSDAY INTO FRIDAY A COMBINED LOW PRESSURE SYSTEM
AND COLD FRONT SHOULD CROSS THE HOOSIER STATE FROM THE WEST. THE LOW
PRESSURE SYSTEM AND COLD FRONT WILL BE FOLLOWED BY A HUGE AREA OF
HIGH PRESSURE.
THE HIGH PRESSURE AREA IS FORECAST TO BE FOLLOWED BY ANOTHER
COMBINED LOW PRESSURE SYSTEM AND COLD FRONT. EXPECT MORE HIGH
PRESSURE TO ARRIVE ACROSS INDIANA BY WEDNESDAY.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 207 PM EST WED NOV 20 2013
PROBLEM IS WHETHER RAIN WILL START LATE TONIGHT.
MODELS CONCUR WARM ADVECTION CAUSING INCREASING CLOUDS AND
SATURATION TONIGHT. RACE WILL BE ON FOR WHICH HAPPENS FIRST...WATER
MAKING IT TO GROUND OR 12Z ARRIVING.
THE MAV IS HIGH WITH POPS COMPARED TO THE MET. LAST TIME
PRECIPITATION MOVED INTO STATE MET TIMING WAS BETTER. LATEST RAP IN
BUFKIT HAS LITTLE OR NO QPF IN CWA THROUGH 10Z. THAT DOES NOT LEAVE
MUCH OF A WINDOW FOR ANYTHING TO START BEFORE THURSDAY. GOING MET
PLUS 10 PERCENT...SO AS TO NOT COMPLETELY DISCOUNT MAV.
VERY LOW CONFIDENCE TEMPERATURE FORECAST. MINOR CHANGES IN
CLOUDS OR PCPN WOULD HAVE A BIG IMPACT. FOR NOW USING
GUIDANCE...WHICH IS ALMOST THE SAME BETWEEN MODELS. EVENING SHIFT
MAY BE ABLE TO MAKE SIGNIFICANT IMPROVEMENTS.
&&
.SHORT TERM /THURSDAY THROUGH SATURDAY/...
ISSUED AT 207 PM EST WED NOV 20 2013
WITH MODELS AGREEING ABOUT WET THURSDAY AND THURSDAY NIGHT...MAIN
QUESTION IS WHEN RAIN WILL END.
FOR SOME REASON MAV POPS DROP SHARPLY FRIDAY. THIS MAKES NO SENSE
LOOKING AT ANY MODEL QPF. IT IS ALSO VERY DIFFERENT FROM EITHER THE
ECM OR NAM GUIDANCE. MAV HAD A SIMILAR PROBLEM DROPPING POPS FOR NO
APPARENT REASON WITH LAST SYSTEM. WILL USE THE MET.
GOING TO SLIGHTLY DAMPER MAV POPS FRIDAY NIGHT. PCPN WILL DEFINITELY
BE ON DOWNSWING. HOWEVER THAT FAR OUT I DONT WANT TO COMPLETELY RULE
OUT SOMETHING PAST 00Z. EVERYTHING POINTS TO CLEARING SATURDAY.
TEMPERATURES...GREAT UNCERTAINTY. THEY WILL BE HEAVILY IMPACTED BY
DETAILS IN TIMING OF PRECIPITATION...CLOUDS...AND A FRONTAL PASSAGE.
CONSENSUS BEST FOR SITUATIONS LIKE THIS. WILL TRY THAT BETWEEN MAV
AND MET. SIGNIFICANT FORECAST CHANGES MAY OCCUR AS NEW INFO ARRIVES.
&&
.LONG TERM /SATURDAY THROUGH TUESDAY/...
ISSUED AT 305 AM EST WED NOV 20 2013
MODELS ARE IN BETTER AGREEMENT ON TIMING OF EXIT OF SYSTEM ON
SATURDAY. ONLY KEEPING A SLIGHT CHANCE IN THE FAR EAST IN THE
MORNING WITH THE UPPER TROUGH AXIS MOVING THROUGH. WITH SOME LAKE
EFFECT POSSIBILITY IN THE FAR NORTHEAST HAVE CARRIED A SLIGHT CHANCE
OF SNOW THERE ALL DAY. BY SATURDAY NIGHT HIGH PRESSURE STARTS
BUILDING IN AND BRINGS IN DRY WEATHER THROUGH MONDAY. BY MONDAY
NIGHT THE SURFACE HIGH IS OFF TO THE SOUTHEAST AND AN UPPER LOW
FORMING OVER THE PLAINS ALLOWS SOME MOISTURE TO WORK IT/S WAY BACK
NORTH ON THE BACK SIDE OF THE SURFACE HIGH. THIS WILL BRING SMALL
CHANCES FOR SNOW MONDAY NIGHT INTO TUESDAY. TEMPERATURES WILL RUN
WELL BELOW NORMAL THROUGH THE LONG TERM.
&&
.AVIATION /DISCUSSION FOR 201800Z TAF ISSUANCE/...
ISSUED AT 1153 AM EST WED NOV 20 2013
VFR CONDITIONS IN PLACE FOR THIS AFTERNOON AND EARLY TONIGHT AS
HIGH PRESSURE WILL BE OVER THE EASTERN GREAT LAKES AND NEW
ENGLAND.
THIS HIGH PRESSURE WILL MOVE MOVE OFF TO THE EAST AND NORTHEAST AS
LOW PRESSURE DEVELOPS OVER SOUTHEAST COLORADO TONIGHT AND A COLD FRONT
DRIFTS IN FROM THE NORTHWEST THURSDAY AFTERNOON. SOUTHERLY WINDS
WILL BRING MOISTURE NORTHWARD DURING THE EARLY HALF OF THURSDAY
AND WILL BE EXPECTING SOME LIGHT RAIN BY LATE MORNING BECOMING
MORE STEADY WITH MVFR/IFR CONDITIONS AT MOST TAF SITES BY THURSDAY
AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...JK
NEAR TERM...JK
SHORT TERM...JK
LONG TERM....CP
AVIATION...DWM
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1204 PM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 1200 PM CST WED NOV 20 2013
THE DRY AIR IS SLOWLY LOSING GROUND AS THE WAA PRECIPITATION
SLOWLY MOVES ACROSS THE CWFA. THE OVERALL TIMING HAS BEEN ADJUSTED
SLIGHTLY BUT THOSE AREAS THAT WERE DRY THIS MORNING SHOULD SEE
RAIN DEVELOPING THIS AFTERNOON. IF CURRENT RADAR TRENDS CONTINUE
THEN THE FAR WESTERN PARTS OF THE AREA MAY SEE AN END TO THE RAIN
THIS AFTERNOON.
UPDATE ISSUED AT 951 AM CST WED NOV 20 2013
BASED ON REPORTS OF SLEET IN THE KIIB AREA...THE FORECAST HAS BEEN
UPDATED TO ADD MENTION OF SLEET IN THE FAR NORTHWEST PART OF THE
AREA.
THE SLEET APPEARS TO BE THE RESULT OF EVAPORATIVE COOLING WITH
SURFACE DEW POINTS BELOW 30 DEGREES. BASED ON RAP TRENDS...THE
LOWEST PART OF THE ATMOSPHERE WILL SLOWLY SATURATE THE REMAINDER
OF THE MORNING AND SHOULD PUSH THE PRECIPITATION OVER TO ALL
RAIN. ANY SLEET ACCUMULATIONS ARE EXPECTED TO BE MINOR WITH AMOUNTS
BRIEFLY BEING NO MORE THAN 0.1 OR 0.2 INCHES.
UPDATE ISSUED AT 904 AM CST WED NOV 20 2013
ADJUSTMENTS HAVE BEEN MADE TO THE FORECAST TO BETTER REFLECT
PRECIPITATION TRENDS ON RADAR AND THE OVERALL TIMING AS IT
MOVES/DEVELOPS NORTHEAST. KIIB CURRENTLY SHOWS SNOW BUT A WEB CAM
IS INCONCLUSIVE ON PRECIPITATION TYPE. IT IS POSSIBLE THAT A BRIEF
MIX MAY OCCUR IN THE FAR NORTHWEST UNTIL THE ATMOSPHERE SATURATES
BUT NO ACCUMULATION IS EXPECTED DUE TO THE STILL WARM GROUND.
&&
.SYNOPSIS...
ISSUED AT 250 AM CST WED NOV 20 2013
A WEAK SHORT WAVE RIDGE AND SURFACE HIGH PRESSURE ARE SLIDING EAST
OF THE AREA WHILE A MODEST STORM SYSTEM PULLS OUT OF THE ROCKIES
INTO THE CENTRAL AND NORTHERN PLAINS. MOISTURE AHEAD OF THIS
SYSTEM IS APPARENT VIA ECHOS ON THE 88D...BUT OTHER THAN A FEW
SPOTS OF SLEET...MOST OF THE RETURNS ARE ALOFT. MORE SUBSTANTIAL
PRECIP IN NORTHWEST MISSOURI IS ASSOCIATED WITH THUNDER DUE TO SUPPORT
FROM THE LOW-LEVEL JET.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 250 AM CST WED NOV 20 2013
MAIN CONCERN IN THE SHORT TERM IS THE IMPACT OF THE TROUGH AS IT
PASSES ACROSS THE AREA TODAY AND THIS EVENING.
SHORT AND LONG TERM MODELS ARE IN GOOD AGREEMENT IN MOVING PRECIP
INTO THE CWA DURING THE MORNING...THEN OUT OF THE CWA DURING THE
EVENING. QPFS ARE FAIRLY CONSISTENT BETWEEN 1/5 AND 1/3 INCH...NOT
SUFFICIENT TO HAVE A NOTABLE IMPACT IN AREAS WHERE DROUGHT
PERSISTS. THE GFS QPF IS AN OUTLIER AND SEEMS TOO WET WHICH MAY
RELATE TO A LARGE AREA OF SEVERELY OVER ANALYZED AND FORECAST
SURFACE DEW POINTS IN THE SOUTH CENTRAL U.S. ON THE 00Z INITIAL.
CLOUDS ARE INCREASING AND WITH RAIN DEVELOPING...TEMPS WILL
STRUGGLE TO CLIMB TODAY. LOOKS LIKE GUIDANCE CAUGHT UP TO THE COOL
VALUES WE HAVE BEEN FORECASTING...SO MADE NO SIGNIFICANT CHANGE TO
MAX TEMPS. AS THE SYSTEM DEPARTS THE AREA...LOW-LEVEL FLOW
BECOMES WEAK AS AN INVERTED TROUGH DEVELOPS. MOISTURE HANGS IN SO
CLOUDS WILL PERSIST AHEAD OF THE NEXT SYSTEM IN LINE...WHICH
SHOULD HOLD UP MIN TEMPS TONIGHT. WOLF
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 250 AM CST WED NOV 20 2013
THE MAIN FORECAST CONCERN CONTINUE TO BE PRECIPITATION TYPE THURSDAY
NIGHT INTO FRIDAY AND TEMPERATURES AFTER SATURDAY. MODELS ARE IN
DECENT OVERALL AGREEMENT THROUGH THE PERIOD WITH SOME TIMING
DIFFERENCES WITH THE ARCTIC AIR FOR THIS WEEKEND.
A WAVE WILL RIDE ALONG A STRONG BAROCLINIC ZONE THAT SETS UP ACROSS
THE REGION DURING THE DAY ON THURSDAY. TEMPERATURES WILL BE WARM
ENOUGH THAT PRECIPITATION WILL FALL AS ALL RAIN THROUGH 06 UTC ON
FRIDAY. A SECOND SHORTWAVE TROUGH WILL DIVE SOUTHEASTWARD OUT OF
SOUTHERN CANADA AFTER 00 UTC ON FRIDAY BRINGING ANOTHER ROUND OF
PRECIPITATION TO THE REGION AND PUSHING A STRONG COLD FRONT EASTWARD. GFS
AND NAM BUFR SOUNDINGS INDICATE THAT PRECIPITATION WILL START OUT AS
RAIN AT MOST LOCATIONS AND BEGIN TO CHANGE OVER TO SNOW VERY SLOWLY
FROM NORTHWEST TO SOUTHEAST AFTER 06 UTC ON FRIDAY. PRECIPITATION
WILL BEGIN TO CHANGE OVER TO THE SOUTHERN HALF OF THE CWA AFTER 12
UTC ON FRIDAY ABOUT THE TIME DRIER AIR BEGINS TO COME SOUTHWARD
CUTTING THE PRECIPITATION OFF. ACCUMULATIONS SHOULD BE LESS THAN A
HALF AN INCH IN THE NORTHWEST.
A SECOND REINFORCING SURGE OF ARCTIC AIR ARRIVES AFTER 00 UTC ON
SATURDAY WITH A SECONDARY COLD FRONT. THERE ARE SOME TIMING DIFFERENCES
BETWEEN THE 00 UTC GFS AND ECMWF WITH THE ARCTIC AIR ARRIVING A
LITTLE MORE SLOWLY WITH THE ECWMF. MODELS SHOW A 1050 MB HIGH DROPPING
SOUTHWARD INTO THE PLAINS WITH A VERY TIGHT PRESSURE GRADIENT OVER
IOWA DURING THE DAY ON SATURDAY. THERE WILL BE LITTLE REBOUND IN
TEMPERATURES DURING THE DAY ON SATURDAY WITH STRONG COLD ADVECTION
AND GUSTY NORTHWEST WINDS. SATURDAY NIGHT WILL BE VERY COLD WITH
HIGH PRESSURE CENTERED OVER CENTRAL AND EASTERN IOWA WITH CLEAR
SKIES AND DEWPOINTS IN THE SINGLE DIGITS WHICH WILL ALLOW
TEMPERATURES TO DROP VERY QUICKLY AS THE WINDS BECOME CALM THROUGH
SUNDAY MORNING. LOW TEMPERATURES MAY VERY WELL NEED TO BE LOWER A
COUPLE MORE DEGREES FOR SUNDAY MORNING. THE SURFACE HIGH
SHIFTS TO THE SOUTHEAST OF THE REGION DURING THE DAY ON SUNDAY
ALLOWING FOR RETURN FLOW TO SETUP AND PULL WARMER AIR NORTHWARD FOR
THE BEGINNING OF NEXT WEEK.
A CLOSED UPPER LEVEL OVER THE SOUTHWESTERN US WILL BEGIN TO LUMBER
EASTWARD EARLY NEXT WEEK WITH MODELS NOW INDICATING PRECIPITATION
ASSOCIATED WITH THIS SYSTEM MOVING TO THE SOUTH OF HIGHWAY 34 DURING
THE DAY ON MONDAY. TEMPERATURES WILL STILL BE COLD ENOUGH ON MONDAY
THAT PRECIPITATION WOULD FALL AS A RAIN SNOW MIX.
AFTER MONDAY ANOTHER CLIPPER SYSTEM WILL DROP SOUTHWARD OUT OF
CANADA AND SWING A COLD FRONT THROUGH THE REGION ALLOWING FOR
TEMPERATURES A COUPLE OF DEGREES FOR THE MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1200 PM CST WED NOV 20 2013
MVFR TO VFR CONDITIONS EXIST ACROSS EASTERN IOWA AND NORTHERN
ILLINOIS AS AN AREA OF RAIN SLOWLY MOVES NORTHEAST. CONDITIONS
WILL DETERIORATE TO MVFR ONCE THE RAIN BEGINS AND THEN IMPROVE TO
VFR WHEN THE RAIN ENDS. HOWEVER...MVFR CIGS ARE DEVELOPING BEHIND
THE RAIN WHICH MAY RESULT IN MVFR CONDITIONS PERSISTING. AFT
06Z/21 A WEAK FRONT WILL MOVE INTO THE AREA CAUSING WIDESPREAD
MVFR CONDITIONS WITH A GOOD PROBABILITY OF IFR CONDITIONS.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
UPDATE...08
SYNOPSIS...WOLF
SHORT TERM...WOLF
LONG TERM...COUSINS
AVIATION...08
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
418 PM EST WED NOV 20 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 416 PM EST WED NOV 20 2013
THE OVERALL WEATHER PATTERN WILL REMAIN QUITE MESSY...MAKING THE
OVERALL FORECAST TRICKY OVER THE NEXT DAY. A LIGHT WET SNOW IS
EXPECTED ACROSS THE INTERIOR WEST THIS EVENING BEFORE A COLD FRONT
PUSHES INTO THE WESTERN CWA THURSDAY AFTERNOON.
LATE THIS AFTERNOON AND TONIGHT...MID-LEVEL SW FLOW AHEAD OF DEEP
TROUGHING DEVELOPING ACROSS CENTRAL CANADA WILL CONTINUE THROUGH
THURSDAY. AN ASSOCIATED SFC TROUGH ORIENTED ACROSS THE UPPER MS
VALLEY BETWEEN LOW PRESSURE OVER HUDSON BAY AND DEVELOPING LOW
PRESSURE ACROSS THE SOUTHERN HIGH PLAINS WILL SLOWLY PUSH EAST. A
WELL-DEFINED MID-LEVEL SHORTWAVE TROUGH CURRENTLY CENTERED NEAR
SIOUX FALLS WILL CONTINUE ITS NORTHEASTWARD PROGRESSION THIS EVENING
AND BE THE MAIN PLAYER IN PRECIPITATION.
MANY CONVOLUTED FORCING MECHANISMS WILL BE AT WORK THIS EVENING. A
COMPLICATED LOW-LEVEL FGEN PATTERN SLOPING TO THE SE WITH HEIGHT AND
A WEAK UPPER-LEVEL JET STREAK MERGING WITH THE POLAR JET WILL IMPOSE
CONFLICTING OMEGA FIELDS ON EACH OTHER. THIS WEAK UPPER JET STREAK
APPEARS TO BE SOME CONVECTIVE FEEDBACK TIED TO A CLUSTER OF
PERSISTENT STORMS OVER IA AND MO. MEANWHILE...WEAK ISENTROPIC ASCENT
ON THE 290-295K SFCS WILL ASSIST SOME MID-LEVEL PRECIP DEVELOPMENT
THIS EVENING. OVERALL...PRECIP LOOKS TO BE CONTROLLED BY THE
ISENTROPIC ASCENT AND Q-VECTOR CONV WITH THE MID-LEVEL WAVE.
A BROKEN SHIELD OF RAIN AND SNOW SHOWERS HAS DEVELOPED ACROSS
WESTERN WI OVER THE PAST SEVERAL HOURS. THIS HAS EASED SOME CONCERNS
THAT THE MIXED OMEGA FIELD WOULD SUPPRESS PRECIP. THE RAP HAS
MAINTAINED A DECENT HANDLE ON THE PRECIP EVOLUTION...SO HAVE
FOLLOWED IT FOR THE OVERALL PRECIP PATTERN WHILE EMPLOYING THE NAM
FOR THE SYNOPTIC EVOLUTION. PRECIP HAS JUST STARTED TO SPREAD INTO
THE INTERIOR WEST NEAR WI AND WILL CONTINUE NORTHWARD INTO THE
EVENING. THERE IS GOOD AGREEMENT THAT THE GREATEST COVERAGE WILL BE
MID TO LATE EVENING ACROSS MUCH OF THE WEST HALF OF THE CWA BEFORE
PRECIP SPREADS EASTWARD OVERNIGHT WITH THE WAVE.
PTYPE LOOKS TO BE MOSTLY WET SNOW FOR ALL BUT THE NEAR LAKE SUPERIOR
SHORELINE AS WETBULB ZERO LEVELS WILL BE WELL BELOW 1KFT. A SUB
700MB DRY LAYER MAY INHIBIT PRECIP INITIALLY...BUT GIVEN CURRENT
RADAR RETURNS IN WI...PRECIP RATES SHOULD BE HIGH ENOUGH TO OVERCOME
THE DRY AIR IN A HOUR OR SO. SNOW RATIOS SHOULD BE QUITE
LOW...GENERALLY 8-10:1 AS MOST LIFT WILL BE W/IN TEMPS HIGHER THAN
THE DGZ. SOME AGGREGATION COULD BE POSSIBLE THROUGH A DEEP
ISOTHERMAL LAYER BETWEEN -3 AND -5C...SO LARGER WET FLAKES ARE
POSSIBLE. TOTAL SNOWFALL THROUGH TONIGHT IS FORECAST TO BE 0.5-1.5
INCHES FOR THE INTERIOR WEST HALF...HIGHEST FROM IRON RIVER TO
CHAMPION. WOULD NOT BE SURPRISED IF SOME LOCATIONS TOP 2 INCHES
GIVEN THE HEAVIER SHOWER ACTIVITY EXPECTED. SHORELINE LOCATIONS WILL
SEE MINIMAL ACCUMULATION AS A RESULT OF LOWER ELEVATION AND
DOWNSLOPING WITH A GENERAL SOUTH WIND.
OVERALL PRECIP COVERAGE WILL DIMINISH SLOWLY AS THE SHIELD
PROGRESSES EASTWARD. HOWEVER...CONTINUED SOUTH TO SSW FLOW OFF LAKE
MI SHOULD YIELD A LAKE-ENHANCED BAND OF RAIN AND SNOW SHOWERS
ACROSS EASTERN DELTA INTO SCHOOLCRAFT COUNTIES. MEANWHILE...MINIMAL
FZDZ WILL BE POSSIBLE ACROSS THE FAR WEST LATE TONIGHT AS SOME
MID-LEVEL DRYING BEHIND THE SHORTWAVE LIMITS LIFT TO THE BARELY
SUB-FREEZING LOW-LEVELS.
THURSDAY...AN OVERALL LULL IN PRECIP IS EXPECTED THROUGH THURSDAY
MORNING BEHIND THE MID-LEVEL WAVE...BUT THE SFC TROUGH WILL BEGIN TO
TRACK ACROSS THE CWA DURING THE AFTERNOON ACROSS THE WEST. HIGH
TEMPS WILL BE FAIRLY EARLY IN THE DAY FOR THE WEST HALF...WITH
FALLING TEMPS THROUGHOUT THE AFTERNOON. HIGHER MOISTURE WITH THE
FRONT AND DROPPING TEMPS WILL INCREASE SNOW SHOWER COVERAGE
WEST...ESPECIALLY FOR THE HIGHER TERRAIN.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 416 PM EST WED NOV 20 2013
SPLIT FLOW PATTERN PERSISTS THROUGH LATE THIS WEEK THEN FLOW PATTERN
BECOMES PHASED THIS WEEKEND INTO INTO FIRST PART OF NEXT WEEK WHICH
ALLOWS COLDEST AIR OF THE SEASON TO ARRIVE. COUPLE OF SHORTWAVES AND
SMALLER JET STREAKS LIFT ACROSS THURSDAY NIGHT INTO FRIDAY. BEST
CHANCE OF SYNOPTIC PRECIPITATION OCCURS THURSDAY NIGHT...ESPECIALLY
OVER THE SOUTH AND EAST. THOUGH THERE COULD BE SOME MIXED RAIN AND
SNOW EARLY THURSDAY EVENING IN THE EAST...SOUNDINGS AND THICKNESSES
BEYOND THAT TIME INDICATE COLD AIR WILL STAY IN PLACE LEADING TO SNOW
AS ONLY PTYPE THROUGH THE THANKSGIVING HOLIDAY.
MAY SEE ENHANCEMENT TO SNOW OVER THE WEST AND NORTH THURSDAY NIGHT
AS TEMPS AT INVERSION TOP OR H85 FALL TO -8C TO -10C GIVING A DELTA
T TO AROUND 13C. MORE SIGNIFICANT CONTRIBUTION FROM THE LAKE
ENHANCEMENT MAY BE OVER HIGHER TERRAIN OF NCNTRL AS LARGER SCALE
FORCING FOR SNOW PERSISTS INTO DAYBREAK ON FRIDAY. A FEW INCHES OF
SNOW MAY OCCUR OVER THURSDAY NIGHT FOR HIGHER TERRAIN OF MARQUETTE
COUNTY AND FOR FAVORED INLAND SNOWBELTS OF WESTERN ALGER COUNTY.
ELSEWHERE SNOW AMOUNTS OF AN INCH OR TWO ARE POSSIBLE.
ARCTIC FRONT WILL BE BLASTING SOUTH ACROSS MANITOBA AND NORTHERN
ONTARIO ON FRIDAY BUT WILL NOT ARRIVE OVER UPR LAKES UNTIL FRIDAY
EVENING. SO...FRIDAY MAY END UP A FAIRLY QUIET BTWN SYSTEMS DAY AS
CWA WILL BE IN WAKE OF THURSDAY NIGHT WAVE AND STILL AHEAD OF ARCTIC
FRONT/STRONG COLD AIR ADVECTION/LK EFFECT SNOWS FOR LATER FRIDAY
NIGHT INTO THE WEEKEND. PARTIAL CLEARING MAY OCCUR BUT WITH LIMITED
WARM AIR ADVECTION AHEAD OF THE FRONT...TEMPS WILL SILL END UP IN
THE 20S. WINDS WILL BE ON THE LIGHTER SIDE COMPARED TO THE WINDY
CONDITIONS COMING FOR THE WEEKEND.
ARCTIC FRONT SWEEPS THROUGH ON FRIDAY NIGHT. TEMPS STARTING OUT THE
EVENING IN THE UPR 20S WILL BE SOLIDLY IN THE TEENS OVER THE WEST BY
DAYBREAK ON SATURDAY AND GOING NOWHERE FAST. TEMPS WILL STAY STEADY
OR FALL SLIGHTLY ON SATURDAY AS PLUNGE OF COLD AIR AT H85 AND H7
DRIVES ACROSS THE GREAT LAKES REGION. EXPECT LK EFFECT SNOWS TO RAMP
UP SIGNIFICANTLY. INTITAL BURST OF SNOW OCCURS FRIDAY EVENING OVER
THE KEWEENAW WITH SUFFICIENT OVERWATER INSTABILITY COMBINING WITH
LOW-LEVEL CONVERGENCE ALONG FRONT. SOUNDINGS INDICATE FAVORABLE
MOISTURE AND LOCATION OF DGZ INTERSECTING PROJECTED UVM. SLR/S
SHOULD INCREASE TO MORE OF A FLUFFY 15-20:1 WITH STRONG NW WINDS IN
BLYR ONLY THING PROHIBITING SLR/S WELL OVER 20:1. ONCE BURST OF
HEAVIER SNOW SLIDES ACROSS CWA WITH THE ARCTIC FRONT...EXPECT
PERIOD OF HEAVY NNW FLOW LK EFFECT THROUGH THE DAY. NNW WINDS IN
BLYR AND A STILL OPEN LK NIPEGON COULD LEAD TO HEAVIEST SNOW
SHOWERS SETTING UP BTWN MQT AND MUNISING. SNOW TOTALS LATER
FRIDAY NIGHT THROUGH SATURDAY WILL BE AT LEAST ADVY ALONG MUCH OF
LK SUPERIOR WITH SOME AREAS SEEING WARNING AMOUNTS OF 10 INCHES IN
12 HOURS. STRONG WINDS WITH THE FLUFFIER SNOW WILL RESULT IN AREAS
OF BLOWING SNOW/REDUCED VSBY. PRETTY CONFIDENT HEADLINES FOR THIS
EVENT WILL BE COMING IN THE NEXT COUPLE DAYS. FOR NOW...WILL KEEP
GRAPHICAL MENTION IN THE EHWO AND A MENTION IN HAZARDOUS WEATHER
OUTLOOK.
DEPARTING DEEPER MOISTURE AND LOWERING INVERSIONS/INCREASING
ANTICYCLONIC FLOW WITH ARRIVAL OF SFC RIDGE WILL PUT A CRIMP IN LK
EFFECT BY SATURDAY NIGHT. STILL MAY SEE ADVY AMOUNTS OVER THE EAST
THOUGH AS OVERWATER INSTABILITY REMAINS MORE THAN SUFFICIENT AND
THERE WILL LIKELY BE SOME UPTICK OF LOW-LEVEL CONVERGENCE AS WINDS
BACK MORE WESTERLY OVR LAND WITH THE ARRIVAL OF THE SFC RIDGE TOWARD
WESTERN UPR MICHIGAN. TRANSITION ON SUNDAY AS SFC RIDGE CROSSES.
COULD BE TRICKY SINCE COLD AIR LINGERS AND WINDS BECOME FAVORABLE
FOR LK EFFECT OFF LK MICHIGAN. INITIALLY WINDS HAVE ENOUGH SOUTHERLY
COMPONENT TO INCLUDE HIGHER POPS OVER MUCH OF SCHOOLCRAFT AND LUCE
COUNTIES...THEN EVENTUALLY ON SUNDAY NIGHT THE WINDS HAVE ENOUGH OF
A WESTERLY COMPONENT TO PUSH MOST OF MORE SIGNIFICANT LK EFFECT
FARTHER TO THE EAST. HOWEVER...CLIPPER LOW PRESSURE SYSTEM DROPPING
TO NORTH OF LK SUPERIOR WILL SPREAD ADDITIONAL SNOW ACROSS NORTHERN
AND EASTERN UPR MICHIGAN.
ANOTHER BOUT OF COLD AIR AND LK EFFECT LIKELY IN WAKE OF THAT
CLIPPER TUESDAY AND WEDNESDAY. ONCE AGAIN AREAS FAVORED BY NNW
FLOW OVER CNTRL AND EASTERN CWA WILL SEE THE BEST SHOT AT HEAVIER
SNOW. PLENTY OF TIME TO ASSESS THIS POTENTIAL ONCE WE GET PAST THE
WEEKEND LK EFFECT SNOWS. PEEK AHEAD TO THANKSGIVING SHOWS THE COLD
AIR PERSISTS WHILE LINGERING LK EFFECT RUNS ITS COURSE. SO...AT
LEAST AT THIS POINT...NO LARGE SCALE LOW PRESSURE SYSTEM/WIDESPREAD
SNOW EXPECTED FOR THE THANKSGIVING TIME FRAME. PROBABLY GOES WITHOUT
SAYING...BUT OBVIOUSLY THERE IS PLENTY OF TIME FOR THIS TO CHANGE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1251 PM EST WED NOV 20 2013
MAIN IMPACTS AT ALL SITES WILL DEVELOP THROUGH THIS EVENING AS
PRECIP SPREADS OVER THE AREA. EXCEPT ELEVATED -SHRA TO FALL THROUGH
A DRY NEAR-SFC LAYER AND CHANGE TO -SN THIS EVENING...MAINLY AT IWD
AND CMX. FORECAST GUIDANCE HAS BEEN CONSISTENTLY UNCLEAR AS TO HOW
HEAVY -SN WILL BE. EXPECTATIONS ARE THAT -SN AT CMX AND IWD WILL
ONLY LOWER VIS AND CIGS TO LOW-END MVFR. THOUGH MOISTURE WILL BE
INCREASING AT ALL SITES AS PRECIP PASSES THROUGH...DOWNSLOPING WITH
GENERALLY SOUTH WINDS SHOULD KEEP CIGS MVFR THROUGH THE EVENING. IFR
CIGS SHOULD THEN DEVELOP AT IWD AND SAW OVERNIGHT AS WINDS BECOME
MORE SSW AND LOW-LEVEL MOISTURE INCREASES BEHIND THE PRECIP. ALL
SITES SHOULD SEE SOME CIG IMPROVEMENT THURSDAY MORNING WITH SOME
LOW-LEVEL DRYING AND MINIMAL LIFT. THE EXCEPTION WILL BE CMX...WHERE
AN APPROACHING COLD FRONT WILL BRING NW WINDS AND INCREASINGLY
UPSLOPE FLOW.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST WED NOV 20 2013
SOUTHERLY WINDS OF UP TO 30 KNOTS FOR EASTERN LAKE SUPERIOR LATE
THIS AFTERNOON WILL DIMINISH TO LESS THAN 20 KNOTS BY THURSDAY
MORNING AS A COLD FRONT NEARS WESTERN LAKE SUPERIOR. THE COLD FRONT
IS EXPECTED TO CROSS LAKE SUPERIOR BEGINNING FAR WEST MID-THURSDAY
MORNING...AND REACHING THE FAR EAST THURSDAY EVENING. WINDS WILL
QUICKLY VEER TO THE NW AROUND 30 KNOTS FOR MUCH OF LAKE SUPERIOR
BEHIND THE FRONT. EXPECT THESE WINDS TO CONTINUE THROUGH THURSDAY
EVENING BEFORE DIMINISHING ON FRIDAY.
STRONG HIGH PRESSURE BUILDING ACROSS CENTRAL CANADA WILL BEGIN TO
IMPINGE ON LOW PRESSURE DEVELOPING OVER THE LOWER GREAT LAKES FRIDAY
AFTERNOON AND EVENING. WEST WINDS OF 20-30 KNOTS ACROSS WESTERN LAKE
SUPERIOR FRIDAY EVENING WILL BECOME NW GALES TO 35 KNOTS WEST TO NW
GALES TO 45 KNOTS EAST SATURDAY MORNING. THE WINDS WILL GRADUALLY
DIMINISH TO UNDER 20 KNOTS BY SUNDAY MORNING. WITH ARCTIC AIR MOVING
OVER THE LAKE...THERE IS A POTENTIAL FOR WIDESPREAD FREEZING SPRAY
SATURDAY AND SATURDAY NIGHT. THEN AN APPROACHING LOW PRESSURE FROM
CANADA WILL BACK WINDS SW TO 20-30 KNOTS BY MONDAY MORNING. ANOTHER
COLD FRONT WILL FOLLOW MONDAY AFTERNOON WITH 20-30 KNOTS NW WINDS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WATCH FROM LATE FRIDAY NIGHT THROUGH LATE SATURDAY NIGHT
FOR LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KLUBER
LONG TERM...JLA
AVIATION...KLUBER
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1253 PM EST WED NOV 20 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 441 AM EST WED NOV 20 2013
UPPER MICHIGAN IS BETWEEN SURFACE FEATURES THIS MORNING...WITH A
1036MB HIGH MOVING EAST FROM THE LOWER GREAT LAKES AND A 996MB LOW
BETWEEN LAKE WINNIPEG AND HUDSON BAY. A COLD FRONT STRETCHES
SOUTHWEST FROM THIS LOW THROUGH NORTHWEST MINNESOTA AND THROUGH THE
DAKOTAS. THE PRESSURE GRADIENT BETWEEN THESE THREE FEATURES HAS
LEAD TO BREEZY CONDITIONS EARLY THIS MORNING...ESPECIALLY OVER LAKE
SUPERIOR AND THE DOWNSLOPE AREAS OF CENTRAL UPPER MICHIGAN. KMQT VAD
WIND DATA SHOWS 45KT WINDS AT 2KFT AND THAT MATCHES UP WELL WITH
THE 46KT GUST RECORDED AT STANNARD ROCK LAST HOUR. THE REST OF
THE UPPER MICHIGAN HAS BEEN GUSTING TO 15-30KTS OVER THE LAST
COUPLE OF HOURS. EXPECT THE GUSTY WINDS TO CONTINUE THROUGH A GOOD
PORTION OF THE DAY TODAY AT VALUES SIMILAR TO WHAT WAS SEEN
OVERNIGHT. WITH A LITTLE BETTER MIXING...THE HIGHER GUSTS WILL
LIKELY BE MORE WIDESPREAD THAN THE SPORADIC VALUES SEEN OVERNIGHT.
FORTUNATELY...THE 40-50KT 925MB WINDS SHOULD STAY ABOVE THE SURFACE
DUE TO THE INVERSION INDICATED JUST BELOW THAT LEVEL. WITH THE
GRADIENT WEAKENING OVER THE AREA FROM WEST TO EAST THIS AFTERNOON
AND EVENING...ALONG THE WITH PRESSURE FALLS NORTH OF LAKE SUPERIOR
EXITING THIS MORNING...EXPECT A DIMINISHING TREND IN THE WINDS THIS
AFTERNOON/EVENING.
THE REST OF THE WEATHER FORECAST WILL DEPEND ON TWO FEATURES...THE
COLD FRONT TO THE WEST OF THE AREA THAT WILL MOVE THROUGH TONIGHT
AND THURSDAY AND A SHORTWAVE CURRENTLY PULLING OUT OF COLORADO.
THIS SHORTWAVE WILL SLIDE NORTHEAST TODAY AND ACROSS UPPER MICHIGAN
THIS EVENING AND EARLY OVERNIGHT HOURS. AS THIS OCCURS...THE COLD
FRONT WILL BE MOVING ACROSS WESTERN LAKE SUPERIOR. MID LEVEL
SOUTHWESTERLY FLOW AHEAD OF THIS WAVE HAS PRODUCED WIDESPREAD MID
CLOUDS FROM THE CENTRAL PLAINS INTO ONTARIO AND EXPECT THAT TO
CONTINUE THROUGH MUCH OF THE DAY TODAY. RADAR HAS BLOSSOMED OVER THE
LAST COUPLE OF HOURS FROM LAKE SUPERIOR THROUGH EASTERN IOWA AND ALL
ASSOCIATED WITH THE MID CLOUDS. THUS...THERE IS PROBABLY SOME PRECIP
FALLING OUT OF THOSE CLOUDS...BUT THE DRIER AIR IS EVAPORATING THE
PRECIP BEFORE REACHING THE SURFACE (NO OBS INDICATING RAIN). MODELS
INDICATING THERE COULD BE A FEW SHOWERS OVER CENTRAL LAKE SUPERIOR
AND THE KEWEENAW TODAY...BUT HAVE MAINLY LEFT AS SLIGHT CHANCES
SINCE THE DRIER LOW LEVELS WILL LIKELY EVAPORATE MUCH OF THE PRECIP.
THERE WAS A BRIEF PERIOD OF 2-3KFT RETURNS JUST NORTHEAST OF
MARQUETTE (WHICH HAD BEEN HINTED AT IN THE ECMWF AND A COUPLE OTHER
MODELS OVER THE LAST COUPLE OF DAYS)...BUT IT QUICKLY DISSIPATED.
THE DRY AIR INDICATED OVER THE AREA ON INITIAL RAP SOUNDINGS
(DEWPOINT DEPRESSIONS OF 15-20C BETWEEN 900-800MB) WILL CONTINUE
THROUGH MUCH OF THE DAY AND WILL PLAY A ROLE IN THE PRECIP TYPE
FORECAST FOR LATE THIS AFTERNOON AND TONIGHT.
MODELS SEEM TO HAVE DECENT AGREEMENT WITH THE PRECIPITATION TIMING
AND LOCATION FOR TONIGHT...AS THE LOWER LEVELS MOISTEN FROM TOP DOWN
WITH THE ARRIVAL OF THE SHORTWAVE. BEST FORCING FROM THE
SHORTWAVE...ALONG WITH 700-500 Q-VECTOR CONVERGENCE AND ISENTROPIC
ASCENT ON 280-290K SFCS TRACKS ACROSS THE MUCH OF THE CWA...WITH THE
GREATEST FOCUS OVER THE CENTRAL AND EAST THIS EVENING. THINK THAT
LAYER IS WHERE MUCH OF THE PRECIPITATION WILL INITIATE LATE THIS
AFTERNOON OVER NORTHERN WISCONSIN AND THEN LIFT NORTHEAST INTO UPPER
MICHIGAN. LOOKING UPSTREAM...THERE IS NOT MUCH FOR LOWER LEVEL
MOISTURE...AND THINK THAT IT WILL TAKE A LITTLE BIT FOR THE
PRECIPITATION TO COOL AND MOISTEN THE LOWER LEVELS. THIS CAN
SOMEWHAT BE SEEN ON MODEL QPF FIELDS WITH THEIR BLOTCHY NATURE AT
TIMES ALONG WITH 280-285K THETA-E SURFACES COND PRESS DEF VALUES
INDICATING SIGNIFICANT LIFT NEEDED TO MOISTEN THE CENTRAL/EASTERN
CWA DURING THE LATE AFTERNOON/EVENING. IN ADDITION...THE HIGHER
RESOLUTION RUNS ARE ALSO SHOWING SOME OF THE DOWNSLOPE FLOW OVER THE
NORTH CENTRAL EATING AWAY AT QPF AMOUNTS. THEREFORE...ALTHOUGH THE
CONFIDENCE IS HIGH ON TIMING/LOCATION...QPF AMOUNTS ARE MORE
UNCERTAIN DUE TO THE DRY AIR AND WILL LIKELY COME DOWN TO HOW
QUICKLY THINGS MOISTEN. THINK WE WILL GET PRECIPITATION...BUT
WONDERING IF THE DRY AIR WILL LOWER QPF AMOUNTS MORE THAN SOME OF
THE MODELS ARE INDICATING. ALSO...THERE ARE SOME HINTS ON THE 06Z
MODEL RUNS THAT THE MAIN PIECE OF SHORTWAVE ENERGY (NOTED BY THE PV
ANOMALY) WILL SLIDE SOUTH OF THE AREA (THROUGH CENTRAL WISCONSIN
AND LOWER MICHIGAN). AS THE SHORTWAVE SLIDES EAST OVERNIGHT...HAVE
DIMINISHED POPS FROM SOUTHWEST TO NORTHEAST.
AS FOR PRECIP TYPE...HAVE FOLLOWED THE WETBULB0 VALUES FOR MUCH OF
THE FORECAST...AS IT HANDLES WHERE THE THERMAL FIELDS WILL GO AS
EVAPORATIVE COOLING AND MOISTENING OCCURS. THIS LEADS TO MUCH OF
THE INTERIOR (HIGHER TERRAIN) WEST/CENTRAL TO QUICKLY TRANSITION TO
OR START AS SNOW. WITH THE UNCERTAINTY ON QPF...HAVE WENT WITH A
MIDDLE GROUND OF 0.1-0.18IN OF QPF OVER THE CENTRAL CWA WITH
LOWER AMOUNTS WEST AND EAST. WITH THAT AREA SHOWING MAINLY
SNOW...WOULD EXPECT AROUND AN INCH OF ACCUMULATION DURING THE
EVENING HOURS. OF COURSE...IF THE HIGHER QPF SHOWN IN THE 00Z
NAM/GFS IS CORRECT...COULD SEE AMOUNTS AROUND OR A LITTLE OVER 2
INCHES AROUND IRON/DICKINSON COUNTY BUT NOT COMPLETELY BUYING THEIR
QUICK 0.2-0.3IN OF QPF LATE THIS AFTERNOON. DID CONTINUE RAIN/SNOW
IN THE DOWNSLOPE WARMED AREAS NEAR LAKE SUPERIOR AND ALSO OVER THE
EAST. AS DEEPER MOISTURE PULLS OUT OF THE WEST OVERNIGHT...MUCH OF
THE REMAINING CLOUD ENDS UP BEING WARMER THAN -5C. THUS...IF ANY
PRECIPITATION DOES OCCUR...WOULD EXPECT IT TO BE AS FREEZING
DRIZZLE. PREVIOUS SHIFT HAD A GOOD HANDLE ON THIS IDEA AND HAVE
ONLY MADE MINOR ADJUSTMENTS TO PUSH IT A LITTLE TO THE WEST.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 513 AM EST WED NOV 20 2013
ALTHOUGH A FAIRLY ACTIVE PATTERN WILL BE THE RULE THRU THE LONG
TERM...NO SIGNIFICANT PCPN EVENTS ARE ANTICIPATED AS NW FLOW WILL
BECOME THE PREVAILING REGIME FROM THIS WEEKEND THRU AT LEAST THE
MIDDLE OF NEXT WEEK. ACTIVE PATTERN WILL COME IN THE FORM OF A
NUMBER OF SHORTWAVES PRODUCING MOSTLY LIGHT PCPN...THOUGH LAKE
SUPERIOR WILL PROVIDE ENHANCEMENT. THE NW FLOW REGIME WILL SET IN
THIS WEEKEND AS A MEAN RIDGE DEVELOPS ALONG THE W COAST WITH
DOWNSTREAM TROF GENERALLY FROM THE MISSISSIPPI VALLEY TO THE E
COAST. INITIAL SURGE OF COLD AIR THIS WEEKEND ASSOCIATED WITH
DEEPENING TROF WILL BE THE COLDEST OF THE SEASON SO FAR. SOURCE
REGION OF THE AIR MASS IS THE YUKON WHERE A NUMBER OF SITES HAVE
BEEN RECORDING TEMPS IN THE -25 TO -35F RANGE OVER THE LAST DAY OR
SO. SHOT OF ARCTIC AIR WILL BE BRIEF AS TROF TEMPORARILY DEAMPLIFIES
LATE WEEKEND AHEAD OF THE NEXT SHORTWAVE THAT DROPS SE. THAT WAVE
WILL THEN REAMPLIFY THE TROF EARLY NEXT WEEK...BRINGING MORE COLD
AIR INTO THE AREA...THOUGH PROBABLY NOT QUITE AS COLD AS THE AIR
MASS THIS WEEKEND. FARTHER DOWN THE LINE INTO LATE NEXT WEEK...THERE
ARE SOME HINTS THAT THE FLOW PATTERN WILL DEAMPLIFY SOME...
SUGGESTING NO SIGNIFICANT PCPN EVENTS ALONG WITH TEMPS RETURNING TO
AROUND NORMAL.
BEGINNING THU...SHORTWAVE LEADING TO PCPN TONIGHT WILL BE EXITING TO
THE NE. MAY SEE LINGERING PCPN OVER THE E IN THE MORNING AND ALSO IN
THE UPSLOPE AREAS OF THE W. WITH DEEPER MOISTURE PULLING OUT...THERE
COULD BE A LITTLE DZ/FZDZ OVER THE FAR W EARLY...THOUGH THERE IS A
FAIR AMOUNT OF UNCERTAINTY IN HOW MUCH DRYING OCCURS ALOFT.
OTHERWISE...A COLD FRONT WILL BE MOVING ACROSS THE FCST AREA THU.
CAA IS NOT ESPECIALLY STRONG...SO THERE SHOULD STILL BE SOME TEMP
RISE OVER THE W IN THE MORNING BEFORE TEMPS BEGIN FALLING IN THE
AFTN. TEMPS OVER THE E SHOULD RISE TO THE LWR 40S UNDER DELAYED CAA.
IN THE AFTN...WELL BEHIND SFC COLD FRONT...IT APPEARS A BAND OF -SN
MAY ORGANIZE ACROSS ROUGHLY THE W HALF OF THE FCST AREA WITHIN A
ZONE OF LOW/MID LEVEL FRONTOGENESIS UNDERNEATH RIGHT ENTRANCE OF
UPPER JET FROM THE NRN PLAINS TO HUDSON BAY AND LEFT EXIT OF JET
EXTENDING FROM THE SW STATES TO THE MIDWEST.
WITH STRENGTHENING FRONTOGENESIS/UPPER DIVERGENCE TRANSLATING ACROSS
THE UPPER LAKES THU NIGHT AHEAD OF NEXT SHORTWAVE SWINGING ACROSS
THE NRN PLAINS/UPPER MISSISSIPPI VALLEY...EXPECT A PERIOD OF PCPN
ACROSS THE FCST AREA. PER FCST SOUNDINGS AND WETBULB ZERO HEIGHTS
ABOVE 1500FT...PCPN SHOULD START AS MAINLY RA OVER THE E BEFORE IT
CHANGES TO SNOW. SNOW WILL BE THE RULE OVER THE W. WITH NOT MUCH IN
THE WAY OF ISENTROPIC ASCENT NOTED...PCPN SHOULD REMAIN ON THE LIGHT
SIDE. CONSENSUS OF MODEL GUIDANCE SHOWS PCPN AMOUNTS IN THE 0.10 TO
0.20 INCH RANGE. WITH A HIGH DGZ GENERALLY BTWN 11K AND 15KFT AND
MOSTLY ABOVE THE BEST UPWARD MOTION...SNOW TO WATER RATIOS WILL BE
ON THE LOW SIDE...PROBABLY 10-15 TO 1. SO...RIGHT NOW IT LOOKS LIKE
A GENERAL 1-2 TO MAYBE 3 INCH SNOW ACCUMULATION ACROSS THE AREA THU
NIGHT INTO FRI MORNING. WITH 850MB TEMPS FALLING TO -8 TO -10C
DURING THE PERIOD OF -SN...THERE WILL BE SOME LAKE ENHANCEMENT UNDER
NRLY LOW-LEVEL FLOW...AND THAT SHOULD LEAD TO GREATEST ACCUMULATIONS
OVER THE HIGHER TERRAIN NEAR LAKE SUPERIOR. HOWEVER...WITH HIGH
DGZ...ENHANCEMENT SHOULDN`T ADD MUCH TO SYNOPTIC SNOW AMOUNTS.
-SN WILL END FROM W TO E FRI IN THE WAKE OF SHORTWAVE...THOUGH A FEW
-SHSN MAY LINGER THRU THE AFTN OFF LAKE SUPERIOR OVER THE ERN FCST
AREA UNDER 850MB TEMPS AROUND -10C.
ATTENTION THEN TURNS TO THE NEXT SHORTWAVE DROPPING SE AND LEADING
TO THE AFOREMENTIONED WEEKEND TROF AMPLIFICATION AND ARCTIC AIR.
BRIEF PERIOD OF VIGOROUS DEEP LAYER FORCING PER QVECTORS OVERTOP
MORE THAN ADEQUATE OVERWATER INSTABILITY WILL YIELD THE TYPICAL
BURST OF MDT/HVY LAKE ENHANCED SNOW SWEEPING OFF LAKE SUPERIOR ALONG
THE ASSOCIATED ARCTIC COLD FRONT FRI NIGHT/EARLY SAT. IN THE WAKE OF
THE FRONT...850MB TEMPS FALL TO -18 TO -21C SAT...RESULTING IN
VIGOROUS NW/NNW FLOW ORIENTED LAKE CONVECTION. CONSENSUS OF GUIDANCE
IS FOR DEEP MOISTURE TO LINGER LONGEST OVER THE ERN FCST AREA. GFS
FCST SOUNDINGS SHOW MOISTURE UP TO 10KFT OR SO. COMBINED WITH LAKE
NIPIGON PRECONDITIONING AND DGZ LIKELY WELL CENTERED WITHIN THE
UPWARD MOTION ZONE...A SIGNIFICANT LAKE EFFECT EVENT LOOKS TO BE
SETTING UP FOR ALGER/LUCE/NRN SCHOOLCRAFT. GUSTY WINDS OF 30-40MPH
WILL ALSO LEAD TO INCREASING BLSN ISSUES AS SNOW ACCUMULATES. OUT
W...SHORTER FETCH...LOWER DGZ AND MOISTURE EXTENDING TO AROUND 6KFT
WILL WORK TO LIMIT SNOW ACCUMULATIONS COMPARED TO THE E.
HOWEVER...TERRAIN ENHANCEMENT PLAYS A BIGGER ROLE OVER THE W THAN
THE E...AND BOUNDARY LAYER WINDS LOOK SUPPORTIVE OF THE TYPICAL
ENHANCED CONVERGENCE AREA FOR GOGEBIC/ONTONAGON INTO CNTRL HOUGHTON
COUNTIES. AS A RESULT...SIGNIFICANT SNOW MAY ALSO OCCUR IN THAT AREA
AS WELL. ANTICIPATE AT LEAST SOLID ADVY FOR THE KEWEENAW...AND THERE
MAY BE A PERIOD WITH WINDS HAVING ENOUGH NRLY COMPONENT FOR
BARAGA/MARQUETTE COUNTIES TO SEE ADVY AMOUNTS AS WELL. ALL OF THESE
DETAILS WILL BE SORTED OUT ONCE THE EVENT MOVES INTO THE SHORT TERM.
OTHERWISE...IT WILL SEEM LIKE MID WINTER CONDITIONS ACROSS THE AREA
SAT/SAT NIGHT WITH GUSTY WINDS/COLD AIR AND WIND CHILLS FALLING TO
ZERO OR BLO.
LES WILL END SUN FROM W TO E AS WINDS BACK TO THE SW AHEAD OF THE
NEXT SHORTWAVE DIVING SE THRU SCNTRL CANADA. HOWEVER...DEVELOPING
STRONG WAA PATTERN MAY LEAD TO AN AREA OF -SN STREAKING SE INTO THE
AREA SUN AFTN/NIGHT. ANOTHER PERIOD OF LAKE EFFECT SNOW SHOULD SET
UP BEHIND THIS SYSTEM EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1251 PM EST WED NOV 20 2013
MAIN IMPACTS AT ALL SITES WILL DEVELOP THROUGH THIS EVENING AS
PRECIP SPREADS OVER THE AREA. EXCEPT ELEVATED -SHRA TO FALL THROUGH
A DRY NEAR-SFC LAYER AND CHANGE TO -SN THIS EVENING...MAINLY AT IWD
AND CMX. FORECAST GUIDANCE HAS BEEN CONSISTENTLY UNCLEAR AS TO HOW
HEAVY -SN WILL BE. EXPECTATIONS ARE THAT -SN AT CMX AND IWD WILL
ONLY LOWER VIS AND CIGS TO LOW-END MVFR. THOUGH MOISTURE WILL BE
INCREASING AT ALL SITES AS PRECIP PASSES THROUGH...DOWNSLOPING WITH
GENERALLY SOUTH WINDS SHOULD KEEP CIGS MVFR THROUGH THE EVENING. IFR
CIGS SHOULD THEN DEVELOP AT IWD AND SAW OVERNIGHT AS WINDS BECOME
MORE SSW AND LOW-LEVEL MOISTURE INCREASES BEHIND THE PRECIP. ALL
SITES SHOULD SEE SOME CIG IMPROVEMENT THURSDAY MORNING WITH SOME
LOW-LEVEL DRYING AND MINIMAL LIFT. THE EXCEPTION WILL BE CMX...WHERE
AN APPROACHING COLD FRONT WILL BRING NW WINDS AND INCREASINGLY
UPSLOPE FLOW.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 441 AM EST WED NOV 20 2013
SOUTHERLY GALES TO 35-40KTS WILL CONTINUE THROUGH MOST OF THE
DAYLIGHT HOURS TODAY OVER EASTERN LAKE SUPERIOR AHEAD OF
A COLD FRONT MOVING THROUGH MINNESOTA TODAY. TIMING OF THE ONGOING
GALE WARNING LOOKS GOOD AND WON/T MAKE ANY CHANGES AT THIS TIME. AS
THE FRONT NEARS LATE THIS AFTERNOON AND EVENING...EXPECT THE WINDS
TO DIMINISH FROM WEST TO EAST THROUGH THE NIGHT. THE FRONT WILL
SLOWLY MOVE EAST ACROSS LAKE SUPERIOR TONIGHT AND THURSDAY...WHICH
WILL SHIFT THE WINDS TO THE NORTHWEST 20-30KTS ON THURSDAY. A HIGH
PRESSURE RIDGE MOVING OVER THE LAKE ON THURSDAY NIGHT WILL SHIFT
WINDS TO THE NORTH AND DIMINISH THEM THURSDAY NIGHT THROUGH FRIDAY.
A WEAK LOW TRACKING FROM THE SOUTHERN PLAINS THROUGH THE LOWER GREAT
LAKES ON FRIDAY WILL KEEP THE NORTHERLY WINDS IN PLACE DUE TO A WEAK
TROUGH SETTING UP OVER UPPER MICHIGAN. THIS TROUGH WILL DIVE SOUTH
ON FRIDAY NIGHT AND WHEN COMBINED WITH A STRONG HIGH BUILDING INTO
THE NORTHERN PLAINS...EXPECT NORTHWESTERLY WINDS TO INCREASE TO
GALES TO 35-40KTS ON SATURDAY AND CONTINUE INTO SATURDAY NIGHT. THIS
EVENT WILL BE SHORT LIVED...AS A RIDGE FROM THAT STRONG HIGH SHIFTS
EAST OVER THE UPPER GREAT LAKES ON SUNDAY AND BRINGS WINDS BELOW
25KTS BY SUNDAY AFTERNOON.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LSZ266-267.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ249>251.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...KLUBER
MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1210 PM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 1122 AM CST WED NOV 20 2013
MINOR ADJUSTMENTS MADE TO EXISTING GRIDS/FCSTS. DECREASED SKY
COVER OVER WRN CWA AND TRENDED DOWNWARD THIS AFTERNOON OVER CTRL
CWA BASED ON LATEST SAT IMAGERY/RAP13 FCST OF MID LVL MOISTURE.
CHANGED PTYPE TO MORE MIXED RAIN/SNOW IN ERN CWA BASED ON
INCREASED POTENTIAL FOR DIABATIC COOLING. LOCATIONS TO THE SOUTH
ALREADY REPORTING SN/IP AT TIMES AND LATEST NAM BUFR SNDGS. HOPWRF
SHOWS ALL SNOW WITH INCREASING ACC POTENTIAL. THIS IS POSSIBLE
CONSIDERING THE USUAL PATTERN OF ALL SNOW OCCURRING IN BULLSEYE OF
GREATEST UVV. ADDED SOME MINOR ACCUMULATIONS FOR NOW. HOWEVER WILL
WATCH SOUTH OF REGION NEXT FEW HRS FOR ANY INDICATIONS OF MORE
ORGANIZED/SUSTAINED POTENTIAL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST WED NOV 20 2013
EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH GFS20.00 500MB
HEIGHTS AND WINDS SHOWS SPLIT FLOW ACROSS NORTH AMERICA...WITH THE
NORTHERN STREAM SET UP ACROSS SOUTHERN CANADA...WHILE THE ZONAL
SOUTHERN STREAM WAS POSITIONED FROM SOUTHERN CALIFORNIA TO GEORGIA.
A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE CURRENTLY LOCATED ACROSS
EASTERN COLORADO WILL TRACK NORTHEASTWARD TODAY...AND THIS WILL
PROVIDE THE LARGE SCALE FORCING FOR A FEW LIGHT RAIN/SNOW SHOWERS IN
WESTERN WISCONSIN AND FAR EASTERN MINNESOTA. RAP FORECAST SOUNDINGS
FOR EAU CLAIRE SHOW AROUND 15UB/S OF LIFT CENTERED AROUND THE 600MB
LAYER..WITH AN ISOTHERMAL LAYER IN THE LOWEST 4000FT HOVERING AROUND
0C. THE WARM NEAR SURFACE TEMPERATURES SHOULD MELT THE PRECIP DURING
THE AFTERNOON...BUT EXPECT A TRANSITION TO A RAIN/SNOW MIX DURING
THE EVENING AND OVERNIGHT HOURS. ANY SNOW ACCUMULATIONS SHOULD BE
CONFINED TO GRASSY SURFACES...AND RANGE FROM A TRACE TO A HALF INCH.
MEANWHILE A STRONGER NORTHERN STREAM SHORTWAVE WILL MOVE ACROSS
SOUTHERN CANADA AND DRIVE A COLD FRONT THROUGH THE DAKOTAS INTO
NORTHWEST MN. A BAND OF POST FRONTAL SNOW WILL GIVE A QUICK 2-3
INCHES OF SNOW UP THERE...BUT THIS WILL WEAKEN AS IT APPROACHES WEST
CENTRAL MN. THEREFORE JUST HAVE CHANCE POPS IN...WITH LITTLE IF ANY
ACCUMULATION. THE MOST NOTICEABLE CHANGE IN THE WEATHER WILL BE
STRONG OVERNIGHT NORTHWEST WINDS OF 25MPH...WITH GUSTS NEAR 35MPH
ASSOCIATED WITH THE COLD AIR ADVECTION BEHIND THE SURFACE FRONT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM CST WED NOV 20 2013
THE BIG WEATHER STORY OVER THE COMING DAYS IS THE SNOW EVENT
EXPECTED THURSDAY AFTERNOON - THURSDAY NIGHT. THE FEATURE EXPECTED
TO BRING MN/WI SNOW THIS WEEK IS CURRENTLY LOCATED IN THE PACIFIC
NORTHWEST AND NORTHERN ROCKIES THIS MORNING...BUT REALLY DOESN`T
SHOW MUCH AMPLIFICATION THIS MORNING. HOWEVER...THERE IS A WELL
DEFINED ARCTIC BOUNDARY NEAR THE US/CANADIAN BORDER IN
MT/ND...WITH COLD AIR ALREADY SPILLING ACROSS THE BORDER. THIS
WAVE WILL DROP SOUTHEAST OVER THE NEXT COUPLE DAYS...BECOME A
LITTLE SHARPER/WELL-DEFINED AND PASS THROUGH THE FORECAST AREA
BETWEEN 21Z THURSDAY AND 12Z FRIDAY. A SW/NE ORIENTATED BAND OF
600-700MB FGEN WILL SWING THROUGH THE FORECAST THIS AREA DURING
THIS TIME...YIELDING A 3-6 HR WINDOW WITH LIGHT TO MODERATE SNOW.
THE 20.00-06Z NAM HAVE A SHARPER WAVE AND STRONGER FGEN. AS A
RESULT...THE NAM HAS HIGHER TOTALS ACROSS A LARGER PORTION OF THE
FORECAST AREA /A LOT OF 3-4" TOTALS/. THE GEM/GFS/ECMWF ARE A
LITTLE MORE DIFFUSE WITH THE BOUNDARY AND HAVE THE HIGHER TOTALS
/2-3"/ ACROSS MAINLY SOUTH CENTRAL MN. THE LAST 3 RUNS OF THE SREF
HAVE MAINTAINED AROUND 1" FOR MSP...THE NAM HAS SHOWN
1-3.5"...OVER THE LAST FEW RUNS...AND THE GFS HAS BEEN THE
STEADIEST WITH RIGHT AROUND 2". THE QPF ISN`T OVERLY IMPRESSIVE
/NOT SURPRISING GIVEN THIS IS A NORTHWEST FLOW EVENT/ BUT THE SNOW
RATIOS SHOULD EXCEED 12:1 GIVEN THE COLD PROFILE. HOWEVER...THE
COMBINATION OF STRONG SURFACE WINDS AND UNCERTAINTY IN OVERLAP OF
BEST OMEGA AND THE DENDRITE GROWTH ZONE SUGGESTS RATIOS SHOULD NOT
BE AS THEY COULD BE...PERHAPS 13-15:1. WE HAVE TRACE AMOUNTS IN
THE NORTHERN FORECAST AREA OF CENTRAL MN TO AROUND 3" IN OUR
SOUTH. AT THIS POINT...THE EVENT LOOKS JUST SHY OF NEEDING A
WINTER WEATHER ADVISORY...ESPECIALLY SINCE MOST OF THE ACTIVITY
WILL FALL BETWEEN THE EVENING AND MORNING COMMUTES.
NONETHELESS...THURSDAY NIGHT WILL FEEL MORE LIKE DECEMBER OR
JANUARY WITH FALLING TEMPS...BRISK NORTHERLY WINDS...AND BANDS OF
SNOW.
THE THURSDAY SYSTEM IS THE FIRST OF TWO ARCTIC BOUNDARIES EXPECTED
OVER THE NEXT 7 DAYS. THE WIND AND COLD TEMPS BEHIND THE THURSDAY
SYSTEM WILL DROP WIND CHILLS NEAR OR BELOW ZERO FOR MUCH OF THE
FORECAST AREA...FOR MOST OF THE WEEKEND. ANOTHER...POTENTIALLY
MORE POTENT /IN TERMS OF COLD/ ARCTIC BOUNDARY IS EXPECTED TO
ARRIVE ON TUESDAY. THIS WOULD BE THE COLDEST AIR OF THE SEASON IF
THE GFS/ECMWF PAN OUT. AS A RESULT...MINUS A BRIEF WARM UP ON
MONDAY...MN/WI WILL SEE HIGHS IN THE TEENS AND 20S AND LOWS IN THE
SINGLE DIGITS ABOVE OR BELOW ZERO FROM SATURDAY-WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1207 PM CST WED NOV 20 2013
SOUTHERLY WINDS WILL CONTINUE AHEAD OF AN APPROACHING COLD FRONT
THAT WILL MOVE THROUGH THE REGION LATE TONIGHT. BEHIND THE FRONT
EXPECT MVFR/IFR CIGS AND NORTHWEST WINDS. AFTER APPROX 15Z WINDS
TO INCREASE AND GUST IN EXCESS OF 20KTS AT TIMES. TODAY MOISTURE
WILL SURGE UP FROM THE SOUTH AND BRING SOME MVFR/IFR CONDITIONS
ACROSS WESTERN WI. AS FRONT MOVES INTO THIS EXISTING AREA OF
MVFR/IFR CIGS TONIGHT SOME DRIZZLE AND FOG POSSIBLE...BUT HAVE
LEFT OUT FOR NOW WITH LOW CONFIDENCE.
KMSP...
LATEST HIRES MODELS HAVE THE LOW CIGS JUST TO THE SOUTH AND EAST OF
THE METRO AREA THIS EVENING/ EARLY OVERNIGHT...SO HAVE TRENDED IN
THAT DIRECTION. CONFIDENCE MUCH HIGHER IN MVFR/IFR CIGS THURSDAY
MORNING AS THE COLD FRONT MOVES IN FROM THE NORTHWEST.
/OUTLOOK FOR KMSP/
FRI...MVFR/IFR AND -SN ENDING. THEN VFR. WINDS NNW AT 10KTS.
SAT...VFR/MVFR. WINDS NW AT 15G25KTS.
SUN...VFR. WINDS SW AT 10-15KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...99
SHORT TERM...JRB
LONG TERM...CLF
AVIATION...99
AREA FORECAST DISCUSSION...UPDATED
NWS TWIN CITIES/CHANHASSEN MN
ISSUED BY NATIONAL WEATHER SERVICE DULUTH MN
1137 AM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 1122 AM CST WED NOV 20 2013
MINOR ADJUSTMENTS MADE TO EXISTING GRIDS/FCSTS. DECREASED SKY
COVER OVER WRN CWA AND TRENDED DOWNWARD THIS AFTERNOON OVER CTRL
CWA BASED ON LATEST SAT IMAGERY/RAP13 FCST OF MID LVL MOISTURE.
CHANGED PTYPE TO MORE MIXED RAIN/SNOW IN ERN CWA BASED ON
INCREASED POTENTIAL FOR DIABATIC COOLING. LOCATIONS TO THE SOUTH
ALREADY REPORTING SN/IP AT TIMES AND LATEST NAM BUFR SNDGS. HOPWRF
SHOWS ALL SNOW WITH INCREASING ACC POTENTIAL. THIS IS POSSIBLE
CONSIDERING THE USUAL PATTERN OF ALL SNOW OCCURRING IN BULLSEYE OF
GREATEST UVV. ADDED SOME MINOR ACCUMULATIONS FOR NOW. HOWEVER WILL
WATCH SOUTH OF REGION NEXT FEW HRS FOR ANY INDICATIONS OF MORE
ORGANIZED/SUSTAINED POTENTIAL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST WED NOV 20 2013
EARLY MORNING WATER VAPOR IMAGERY TOGETHER WITH GFS20.00 500MB
HEIGHTS AND WINDS SHOWS SPLIT FLOW ACROSS NORTH AMERICA...WITH THE
NORTHERN STREAM SET UP ACROSS SOUTHERN CANADA...WHILE THE ZONAL
SOUTHERN STREAM WAS POSITIONED FROM SOUTHERN CALIFORNIA TO GEORGIA.
A LOW AMPLITUDE SOUTHERN STREAM SHORTWAVE CURRENTLY LOCATED ACROSS
EASTERN COLORADO WILL TRACK NORTHEASTWARD TODAY...AND THIS WILL
PROVIDE THE LARGE SCALE FORCING FOR A FEW LIGHT RAIN/SNOW SHOWERS IN
WESTERN WISCONSIN AND FAR EASTERN MINNESOTA. RAP FORECAST SOUNDINGS
FOR EAU CLAIRE SHOW AROUND 15UB/S OF LIFT CENTERED AROUND THE 600MB
LAYER..WITH AN ISOTHERMAL LAYER IN THE LOWEST 4000FT HOVERING AROUND
0C. THE WARM NEAR SURFACE TEMPERATURES SHOULD MELT THE PRECIP DURING
THE AFTERNOON...BUT EXPECT A TRANSITION TO A RAIN/SNOW MIX DURING
THE EVENING AND OVERNIGHT HOURS. ANY SNOW ACCUMULATIONS SHOULD BE
CONFINED TO GRASSY SURFACES...AND RANGE FROM A TRACE TO A HALF INCH.
MEANWHILE A STRONGER NORTHERN STREAM SHORTWAVE WILL MOVE ACROSS
SOUTHERN CANADA AND DRIVE A COLD FRONT THROUGH THE DAKOTAS INTO
NORTHWEST MN. A BAND OF POST FRONTAL SNOW WILL GIVE A QUICK 2-3
INCHES OF SNOW UP THERE...BUT THIS WILL WEAKEN AS IT APPROACHES WEST
CENTRAL MN. THEREFORE JUST HAVE CHANCE POPS IN...WITH LITTLE IF ANY
ACCUMULATION. THE MOST NOTICEABLE CHANGE IN THE WEATHER WILL BE
STRONG OVERNIGHT NORTHWEST WINDS OF 25MPH...WITH GUSTS NEAR 35MPH
ASSOCIATED WITH THE COLD AIR ADVECTION BEHIND THE SURFACE FRONT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 340 AM CST WED NOV 20 2013
THE BIG WEATHER STORY OVER THE COMING DAYS IS THE SNOW EVENT
EXPECTED THURSDAY AFTERNOON - THURSDAY NIGHT. THE FEATURE EXPECTED
TO BRING MN/WI SNOW THIS WEEK IS CURRENTLY LOCATED IN THE PACIFIC
NORTHWEST AND NORTHERN ROCKIES THIS MORNING...BUT REALLY DOESN`T
SHOW MUCH AMPLIFICATION THIS MORNING. HOWEVER...THERE IS A WELL
DEFINED ARCTIC BOUNDARY NEAR THE US/CANADIAN BORDER IN
MT/ND...WITH COLD AIR ALREADY SPILLING ACROSS THE BORDER. THIS
WAVE WILL DROP SOUTHEAST OVER THE NEXT COUPLE DAYS...BECOME A
LITTLE SHARPER/WELL-DEFINED AND PASS THROUGH THE FORECAST AREA
BETWEEN 21Z THURSDAY AND 12Z FRIDAY. A SW/NE ORIENTATED BAND OF
600-700MB FGEN WILL SWING THROUGH THE FORECAST THIS AREA DURING
THIS TIME...YIELDING A 3-6 HR WINDOW WITH LIGHT TO MODERATE SNOW.
THE 20.00-06Z NAM HAVE A SHARPER WAVE AND STRONGER FGEN. AS A
RESULT...THE NAM HAS HIGHER TOTALS ACROSS A LARGER PORTION OF THE
FORECAST AREA /A LOT OF 3-4" TOTALS/. THE GEM/GFS/ECMWF ARE A
LITTLE MORE DIFFUSE WITH THE BOUNDARY AND HAVE THE HIGHER TOTALS
/2-3"/ ACROSS MAINLY SOUTH CENTRAL MN. THE LAST 3 RUNS OF THE SREF
HAVE MAINTAINED AROUND 1" FOR MSP...THE NAM HAS SHOWN
1-3.5"...OVER THE LAST FEW RUNS...AND THE GFS HAS BEEN THE
STEADIEST WITH RIGHT AROUND 2". THE QPF ISN`T OVERLY IMPRESSIVE
/NOT SURPRISING GIVEN THIS IS A NORTHWEST FLOW EVENT/ BUT THE SNOW
RATIOS SHOULD EXCEED 12:1 GIVEN THE COLD PROFILE. HOWEVER...THE
COMBINATION OF STRONG SURFACE WINDS AND UNCERTAINTY IN OVERLAP OF
BEST OMEGA AND THE DENDRITE GROWTH ZONE SUGGESTS RATIOS SHOULD NOT
BE AS THEY COULD BE...PERHAPS 13-15:1. WE HAVE TRACE AMOUNTS IN
THE NORTHERN FORECAST AREA OF CENTRAL MN TO AROUND 3" IN OUR
SOUTH. AT THIS POINT...THE EVENT LOOKS JUST SHY OF NEEDING A
WINTER WEATHER ADVISORY...ESPECIALLY SINCE MOST OF THE ACTIVITY
WILL FALL BETWEEN THE EVENING AND MORNING COMMUTES.
NONETHELESS...THURSDAY NIGHT WILL FEEL MORE LIKE DECEMBER OR
JANUARY WITH FALLING TEMPS...BRISK NORTHERLY WINDS...AND BANDS OF
SNOW.
THE THURSDAY SYSTEM IS THE FIRST OF TWO ARCTIC BOUNDARIES EXPECTED
OVER THE NEXT 7 DAYS. THE WIND AND COLD TEMPS BEHIND THE THURSDAY
SYSTEM WILL DROP WIND CHILLS NEAR OR BELOW ZERO FOR MUCH OF THE
FORECAST AREA...FOR MOST OF THE WEEKEND. ANOTHER...POTENTIALLY
MORE POTENT /IN TERMS OF COLD/ ARCTIC BOUNDARY IS EXPECTED TO
ARRIVE ON TUESDAY. THIS WOULD BE THE COLDEST AIR OF THE SEASON IF
THE GFS/ECMWF PAN OUT. AS A RESULT...MINUS A BRIEF WARM UP ON
MONDAY...MN/WI WILL SEE HIGHS IN THE TEENS AND 20S AND LOWS IN THE
SINGLE DIGITS ABOVE OR BELOW ZERO FROM SATURDAY-WEDNESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 555 AM CST WED NOV 20 2013
SOUTHERLY WINDS WILL CONTINUE AHEAD OF AN APPROACHING COLD FRONT
THAT WILL MOVE THROUGH THE REGION LATER TONIGHT. BEHIND THE FRONT
EXPECT MVFR/IFR CIGS AND NORTHWEST WINDS OF GUSTING IN EXCESS OF
25KTS AT TIMES. MEANWHILE TODAY MOISTURE WILL SURGE UP FROM THE
SOUTH AND BRING SOME MVFR/IFR CONDITIONS ACROSS WESTERN MN...WHICH
WILL LINGER OVERNIGHT AT KEAU AND KRNH.
KMSP...
LATEST HIRES MODELS HAVE THE LOW CIGS JUST TO THE SOUTH AND EAST
OF THE METRO AREA THIS EVENING/OVERNIGHT...SO HAVE TRENDED IN THAT
DIRECTION. CONFIDENCE IS HIGHER IN MVFR CIGS THURSDAY MORNING AS
THE COLD FRONT MOVES IN FROM THE NORTHWEST.
/OUTLOOK FOR KMSP/
THU...VFR WITH MVFR/IFR AND -SN LATE. WINDS NNW AT 15G20KTS.
FRI...MVFR/IFR AND -SN ENDING. THEN VFR. WINDS NNW AT 10KTS.
SAT...VFR/MVFR. WINDS NW AT 15G25KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
UPDATE...99
SHORT TERM...JRB
LONG TERM...CLF
AVIATION...JRB
AREA FORECAST DISCUSSION...UPDATED
NWS DULUTH MN
1128 AM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 1124 AM CST WED NOV 20 2013
LOW AMPLITUDE FAST-MOVING S/W TROF LOCATED OVER IOWA AS OF LATE
THIS MORNING WILL RAPIDLY EJECT NORTHEASTWARD TO THE UPPER
PENINSULA OF MICHIGAN BY LATE THIS EVENING WHILE DEAMPLIFYING.
THIS WAVE IS MOSTLY A MID-LEVEL FEATURE..AND CROSS SECTIONS REVEAL
A FAIR AMOUNT OF INSTABILITY AVAILABLE FOR FORCING TO ACT ON IN
THE 700-500 MB LAYER. THIS SEEMS TO BE SUPPORTED BY THE
DEVELOPMENT OF CONVECTIVE RADAR ECHOES AND SEVERAL LIGHTNING
STRIKES OVER NCENT IOWA OVER THE PAST 90 MINUTES OR SO. WHILE PEAK
PERIOD OF STRONGEST ASCENT IS ONLY EXPECTED TO BE 2 TO 4
HOURS..MAGNITUDE OF VERTICAL MOTIONS AND PRECIP RATES MAY BE
SUFFICIENT TO ELICIT A CHANGE OVER TO WET SNOW FOR A SHORT TIME
ACROSS OUR FAR SOUTHEAST CWA LATE THIS AFTERNOON/EARLY EVENING.
STILL..A PRECISE CALL ON PTYPE IS QUITE DIFFICULT AS NEAR SURFACE
TEMPS HAVE RISEN INTO THE LOWER 40S..BUT YET AIRMASS IS STILL QUITE
FAR FROM SATURATION AS WELL. THUS..IT WILL BE A BATTLE BETWEEN
DIABATIC/EVAPORATIONAL/SUBLIMATION COOLING EFFECTS AND NEAR SURFACE
WARM AIR..WITH THE ULTIMATE DETERMINING FACTOR LIKELY BEING PRECIP
RATE IN MANY LOCALES.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY AFTERNOON)
ISSUED AT 345 AM CST WED NOV 20 2013
MAIN CONCERNS IN THE SHORT TERM ARE FOCUSED AROUND THE RAIN/SNOW MIX
EXPECTED TO DEVELOP LATE THIS MORNING AND CONTINUE THROUGH THE
AFTERNOON AND EVENING MAINLY ACROSS NW WI EVENTUALLY SPREADING
WWD INTO EXTREME E-CENTRAL/NE MN...AND THE COLD FRONT CURRENTLY
OVER ERN ND EXPECTED TO PUSH EWD THROUGH THE NORTHLAND TONIGHT AND
EARLY THURSDAY WITH SCATTERED SNOW SHOWERS AND GUSTY N/NW WINDS
AND FALLING TEMPERATURES THROUGH THUR AFTERNOON. THE OTHER AREA OF
CONCERN WILL BE THE LAKE EFFECT SNOW POTENTIAL ALONG THE SOUTH
SHORE THUR AFTERNOON. FAVORABLE CONDITIONS WILL ALLOW FOR
ACCUMULATING LES TO INITIATE AND CONTINUE THROUGH THE NIGHT.
WEAK UPPER TROUGH CURRENTLY SITUATED OVER THE WRN US WITH A LOW
AMPLITUDE RIDGE ACROSS THE ERN GREAT LAKES/NERN US. AT THE
SFC...HIGH PRESSURE IS DOMINATING THE CNTRL GRT LKS AND AN AREA OF
LOW PRESSURE IS DEVELOPING OVER THE FRONT RANGE OF THE ROCKIES.
THIS SET UP IS PRODUCING A TIGHT PRESSURE GRADIENT ACROSS THE
UPPER MIDWEST AND FAVORABLE CONDITIONS FOR STRONG SLY FLOW AND
GUSTY WINDS. THIS WARM FLOW HAS ALLOW TEMPERATURES TO REMAIN MILD
THIS MORNING...WITH TEMPS FROM THE MID 30S TO LOWER 40S.
A WEAK S/W WILL EJECT NEWD OUT OF THE SRN ROCKIES/PLAINS THIS
MORNING AND WILL TRACK FROM OKLA TO THE MICH U.P. TODAY AND TONIGHT.
THIS SYSTEM WILL INTERACT WITH THE RELATIVELY WARM AND MOIST AIR
MASS IN PLACE TO PRODUCE MAINLY A RAIN/SNOW MIX OVER THE ERN HALF OF
THE NORTHLAND. TEMP PROFILES IN THE MID LEVELS WILL HOVER AROUND OR
JUST BELOW FREEZING...WITH SFC TEMPS A FEW DEG ABOVE 32F. THIS
SET UP SHOULD BE CONDUCIVE FOR A RA/SN MIX. A FEW OF THESE SHOWERS
COULD BECOME ENHANCED AS THE THERMAL GRADIENT TIGHTENS THIS
AFTERNOON/EVENING WITH THE APPROACH OF A STRONG COLD FRONT FROM THE
WEST. THE STRONG MOISTURE CONTENT AND POTENTIALLY INTENSIFYING
SHOWERS MIGHT ALLOW THE PRECIP TO CHANGE OVER TO ALL SNOW IN SOME
LOCATIONS. HOWEVER...WILL BE DIFFICULT TO NAIL DOWN THESE SMALL
SCALE DETAILS.
TONIGHT AND MAINLY TOMORROW THE MAIN AREA OF CONCERN SHIFTS TO THE
APPROACHING COLD FRONT. THE FRONT IS EXPECTED TO TRACK FAIRLY SLOWLY
EWD THROUGH NRN MN LATE TONIGHT AND THROUGH THUR MORNING AS THE S/W
TO THE EAST LIFTS INTO THE GRT LKS. THE COLD FRONT WILL HAVE AN
ARCTIC AIR MASS BEHIND IT AND USHER IN SNOW SHOWERS OVER MUCH OF THE
NORTHLAND. THE SNOW WILL BE FAIRLY WIDESPREAD DURING THE DAY
THURSDAY...BUT ONLY LIGHT AMTS ARE EXPECTED WITH DRY AIR MOVING
IN BEHIND THE FRONT. HIGH PRESSURE WILL BUILD IN OVER THE
DAKOTAS...NW MN...AND WRN ONTARIO THUR AFTERNOON AND ALLOW WINDS
TO SHIFT TO THE NORTH AND BECOME QUITE GUSTY. THE COLD TEMPS AND
STRONG WINDS WILL MAKE CONDITIONS FEEL VERY COLD. HIGHS WILL LEVEL
OUT IN THE TEENS TO THE NORTH AND LOW 30S TO THE SOUTH...WITH
STEADY OR FALLING TEMPS FROM WEST TO EAST THROUGH THE DAY.
THE COLD AIR MASS MOVING IN AND VEERING NORTH WINDS OVER WRN LAKE
SUPERIOR WILL PRODUCE FAVORABLE CONDITIONS FOR LAKE EFFECT SNOW
ALONG THE SOUTH SHORE BEGINNING THUR AFTERNOON. BL MOISTURE PROFILES
WILL BE HIGH ENOUGH DURING THE AFTERNOON TO ALLOW THE LES TO
INITIATE BEFORE THE DRIER AIR MOVES IN. STEEP LOW LVL LAPSE RATES
AND WEAK INSTABILITY WITH A LONG FETCH OVER LS WILL ALL AID IN THE
DEVELOPMENT OF SNOW SHOWERS OVER BAYFIELD ASHLAND AND IRON
COUNTIES. COULD SEE AN INCH OR SO OF ACCUMULATION BEFORE 6 PM
THURSDAY...AFTER WHICH ADDITIONAL SNOW IS LIKELY.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 345 AM CST WED NOV 20 2013
THE EXTENDED PERIOD WILL FEATURE SOME VERY COLD AIR MOVING OVER THE
NORTHLAND FRIDAY INTO FRIDAY NIGHT AND PERIODS OF LAKE EFFECT SNOW.
A COLD FRONT WILL MOVE THROUGH THE REGION THURSDAY. THURSDAY
NIGHT...A MID LEVEL FRONT AND FGEN WILL BRING A CHANCE FOR SNOW TO
ABOUT THE SOUTHERN HALF OF THE NORTHLAND...WITH CHANCES HIGHEST OVER
NORTHWEST WISCONSIN. SOME LIGHT SNOWFALL...UP TO 2 INCHES IN
SPOTS...WILL BE POSSIBLE. THE EXCEPTION WILL BE THE SNOWBELT OF
ASHLAND AND IRON COUNTIES WHICH SHOULD SEE HIGHER SNOWFALL DUE TO
NORTHERLY WINDS DEVELOPING AND THE STABILITY BEING LOW ENOUGH FOR
LAKE EFFECT SNOW.
ANOTHER SHORTWAVE AND STRONGER COLD FRONT WILL SWEEP THROUGH THE
AREA FRIDAY INTO FRIDAY NIGHT. THE FRONT WILL BRING A CHANCE FOR
LIGHT SNOW...WITH LIMITED SNOW ACCUMULATIONS EXPECTED. AT THIS
TIME...WE THINK A NARROW BAND OF STRONGER FAST MOVING SNOW SHOWERS
WILL BE POSSIBLE WITH THE FRONT. 850MB TEMPS ARE FORECAST TO DROP TO
-23C FAR NORTH TO -19C IN OUR SOUTHERN ZONES BY 12Z SAT. WE ARE
EXPECTING LOWS SATURDAY MORNING TO BE AROUND ZERO NORTH TO 10 TO 15
ACROSS NORTHERN WISCONSIN. TEMPS COULD BE EVEN COLDER IF WINDS CAN
DROP OFF MORE THAN IS EXPECTED ATTM. HIGHS SATURDAY WILL ONLY REACH
AROUND 10 ABOVE ACROSS FAR NORTHERN MINNESOTA...TO THE TEENS SOUTH.
THE LAKE WILL BECOME ACTIVE AGAIN FRIDAY NIGHT INTO SATURDAY
NIGHT...WITH SOME SIGNIFICANT SNOWFALL LIKELY ACROSS THE SNOWBELT OF
ASHLAND AND IRON COUNTIES WITH THE VERY COLD TEMPS CROSSING THE LAKE
WITH A FAVORABLE FETCH.
WAA WILL DEVELOP SATURDAY NIGHT INTO SUNDAY...WITH SOME LIGHT SNOW
POSSIBLE ACROSS THE REGION. ANOTHER STRONG COLD FRONT WILL THEN
SWEEP THROUGH THE REGION MONDAY INTO MONDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 550 AM CST WED NOV 20 2013
VFR CONDITIONS COVERED THE NORTHLAND EARLY THIS MORNING. A LLJ
REMAINED OVER MUCH OF THE NORTHLAND CREATING SOME LLWS THAT WILL
CONTINUE EARLY THIS MORNING.
A COLD FRONT IN NORTHWEST MINNESOTA WILL CONTINUE TO SLOWLY MOVE
SOUTHEAST TODAY. MVFR CEILINGS WILL MOVE IN FROM THE
NORTHWEST...AND WERE SEEN IN OBSERVATIONS/SATELLITE OVER PORTIONS
OF MB/OT. THE RAP WAS HANDLING THESE CLOUDS FAIRLY WELL. MORE MVFR
OR LOW END VFR CLOUDS ARE EXPECTED TO DEVELOP AND MOVE NORTH
TOWARD NORTHERN WISCONSIN THIS AFTERNOON. MVFR OR IFR CEILINGS ARE
EXPECTED OVER ALL AREAS TONIGHT. SOME LIGHT PRECIPITATION WILL
DEVELOP AS WELL TODAY...BOTH BEHIND THE COLD FRONT...AND WELL
AHEAD OVER NORTHERN WISCONSIN/FAR EASTERN MINNESOTA LATER THIS
AFTERNOON. THE PRECIPITATION MAY START OUT AS RAIN...OR A
MIX...BUT WILL TRANSITION TO MAINLY SNOW TONIGHT. SOUNDINGS ALSO
SUGGEST SOME DRYING ALOFT LATER TONIGHT WHICH COULD LEAD TO
DRIZZLE AS WE LOSE ICE IN THE CLOUDS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH 43 26 27 14 / 30 30 30 30
INL 40 16 19 5 / 40 60 30 10
BRD 46 22 25 13 / 10 20 20 20
HYR 41 30 30 19 / 40 50 40 60
ASX 44 32 32 20 / 40 50 60 50
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ121-
142-143-146>148.
SMALL CRAFT ADVISORY UNTIL 10 PM CST THIS EVENING FOR LSZ140-141.
&&
$$
UPDATE...MILLER
SHORT TERM...BJT
LONG TERM...MELDE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1234 PM CST Wed Nov 20 2013
.UPDATE...
Issued at 1216 PM CST WED NOV 20 2013
We have trimmed PoPs back into the 20-30 percent range from mid to
late afternoon as isentropic upglide along a weakening low level
jet shifts east of the region. We also did some adjusting to
expected high temperatures out east as cloud cover and
precipitation have held down temperatures all morning.
On the other hand, partial clearing has resulted in a jump to
temperatures across southeastern Kansas and western Missouri this
morning. We have made adjustments to sky grids into this afternoon
along with bumping up expected highs a degree or two around Joplin.
We did also do an unscheduled fire weather update as mixing in the
partial clearing area has resulted in dew points dropping into the
lower and middle 20s. This will result in elevated fire weather
conditions for the remainder of this afternoon south of Interstate
44 and west of Highway 65.
&&
.SHORT TERM...(Today and Tonight)
Issued at 304 AM CST WED NOV 20 2013
Currently...as expected, isentropic upglide is underway in the
300-310K layer with a solid pressure advection signal. Regional
radar has seen a gradual increase in showers and even a few
lightning strikes. MUCAPE according to the short range models is
in the 100-200 J/kg range (slightly higher to the west over KS/OK)
and supports at least a slight chance mention for thunder for the
remainder of this morning.
Could see varying precip types this morning given the very dry low
levels. The 00z soundings from KSGF/KLZK/KSHV all show a very
stout low level dry layer. RUC initializations from 07z still
indicating dewpoint depressions around 900mb in the 30-50 C range!
With a southeast downsloping wind, dewpoints are struggling at the
surface, dropping into the teens in many locations, especially
northwest of the plateau and ahead of the incoming radar echoes.
Precip falling from these echoes is likely falling as (mainly)
rain, but cannot rule out some poor man`s sleet mixing in given a
6000 foot layer of wet bulb temperatures aloft at or just below 0C.
With a little bit of elevated instability, cannot argue with very
small hail with any storms.
The short wave responsible for instigating this activity will move
from the central Plains and toward the Great Lakes region through
the day. The area will remain in the left exit region of an upper
jet most of the morning, so there will be broad scale lift
support. In the mid to lower levels, isentropic upglide/pressure
advection will continue in the 300-310K layer this morning,
shunting to the northeast into northern Missouri during the
afternoon hours. Will maintain scattered to numerous shower
wording this morning with a mention of sleet possibly mixing in
from time to time through the mid morning hours. During the
afternoon, have lowered PoPs a bit and changed to chance wording
as most of the shower activity should be exiting into central and
northern Missouri.
There will likely be a brief lull in the rainfall from late this
afternoon into the early evening. However, the next shortwave will
be ready to move into the region during the overnight hours. Have
ramped up PoPs during the overnight hours as showers and a few
embedded thunderstorms should envelope the area from southwest to
northeast.
Temperatures will be a challenge today given wet bulbing,
scattered showers and cloud cover. Have held close to a consensus
of the MOS and raw models, which keep readings mainly in the 50-55
degree range (slightly warmer across far southwestern MO).
.LONG TERM...(Thursday through Tuesday)
Issued at 304 AM CST WED NOV 20 2013
Periods of rain are expected on Thursday across the entire outlook
area. NAM/GFS continue to suffer from convective feedback, though
it is indicative of locally heavy rainfall potential. This heavier
rainfall will likely occur in a narrow, mesoscale band, almost
impossible to pin point. Yet another shortwave will move into the
region later Thursday night into early Friday resulting in yet
more periods of rainfall. By Thursday night, model consensus
indicates that a cold front and shallow low level cold airmass
will begin moving into the region, spreading across the entire
area Friday morning. At this point, thermal profiles from all
models support a wet forecast, rather than wintry. We will have
to keep a very sharp eye on this airmass intrusion, especially
across the northwest third of the CWA.
Some good news is that the global models continue to indicate a
progressive invasion of colder and drier air for Friday night.
Have lowered PoPs a bit more and if present trends continue,
Friday night may only feature a few lingering light rain showers
or flurries. Storm total rainfall accumulation for this event
continues to suggest a widespread 0.50" to 2.00" with a mesoscale
band of locally higher amounts possible.
The weekend will be cold and mostly dry as a 1050mb surface high
pressure settles down from southern Canada into the Midwest
region. The center of the high will be near the Missouri Ozarks
area Saturday night into Sunday morning. This will be the coldest
night with clear skies and light winds...temperatures will be
likely in the middle to upper teens. High temperatures this
weekend will be only in the 30s despite sunshine.
The next big question will be what does the cut off low over the
southwest U.S. do for the early part of next week and how much
cold air will be around when this system moves out into the
southern Plains region.
The latest runs of the GFS..ECMWF...GEM...indicate this system
will affect the area by Monday morning. There is still some
disagreement on track and timing but the consensus is that precip
may begin to develop late Sunday night into Monday morning and
spread into the area. It does appear at this time that light
wintry weather mainly in the form of light snow will be possible.
The ECMWF and GEM are the most bullish with the QPF. With
temperatures not climbing much on Monday...there will be a
rain/snow mix possible and lingering through Monday night. Will
need to monitor future trends with model data but the Monday
morning commute could be tricky with light snow in the area but
amounts appear light at this time up to an inch possible. Below
average temperatures will continue through middle of next week
with another surge of cold air moving in.
&&
.AVIATION...(For the 18Z TAFS through 18Z Thursday Afternoon)
Issued at 1216 PM CST WED NOV 20 2013
As of early this afternoon, rain showers have vacated the
southern Missouri TAF sites. We may still see a scattered shower
or two this afternoon...otherwise broken mid-level clouds and VFR
conditions will prevail. Shower coverage will then increase
tonight...especially after midnight. Steadier rain and even a few
thunderstorms are then expected Thursday morning as a frontal
boundary sets up over the region. High confidence exists in low-
end MVFR flight conditions. There is also a decent signal there
for IFR, but IFR coverage will depend on the exact location of
this frontal boundary and heavier precipitation. We have elected
to go with a TEMPO IFR group to cover this for now. One other
final impact to note will be low level wind shear conditions from
this evening into Thursday morning.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
KS...NONE.
&&
$$
UPDATE...Schaumann
SHORT TERM...Gagan
LONG TERM...Gagan/Griffin
AVIATION...Schaumann
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
919 AM MST WED NOV 20 2013
.UPDATE...
ARCTIC FRONT PUSHED THROUGH THE FORECAST AREA EARLY THIS MORNING.
TEMPERATURES HAVE FALLEN INTO THE UPPER TEENS TO LOWER 20S ACROSS
THE AREA. RADAR SHOWING LIGHT TO MODERATE SNOW ACROSS
WHEATLAND...GOLDEN VALLEY AND MUSSELSHELL COUNTIES MOVING EAST BUT
THE BAND ITSELF IS SLOWING SINKING SOUTH AND HAS ENTERED NORTHWEST
YELLOWSTONE COUNTY. GFS AND RAP PAINT A GOOD SWATH OF QPF ACROSS
WHEATLAND COUNTY TO MUSSELSHELL COUNTY SO HAVE ADDED THESE AREAS
TO THE SNOW ADVISORY FOR THE DAY. ONLY OTHER CHANGES WAS SOME
WORDING WITH THE ADVISORY. SINCE THE ARCTIC FRONT MOVED IN EARLIER
THAN ANTICIPATED AND ROAD SURFACES ARE WELL BELOW FREEZING THERE
MAY NOT BE THE INITIAL SNOWMELT ON ROADS FOLLOWED BY A QUICK
FREEZE. HOWEVER...TRAFFIC MAY STILL ALLOW FOR SOME MELTING
INITIALLY. IN ANY CASE...STILL LOOKING AT DIFFICULT TRAVEL
CONDITIONS SPREADING FROM NORTH TO SOUTH ACROSS THE ENTIRE AREA
TODAY. UPDATED FORECAST AND ADVISORIES HAVE BEEN ISSUED. HOOLEY
&&
.SHORT TERM...VALID FOR TDY AND THU...
ARCTIC COLD FRONT PUSHED THROUGH THE BILLINGS AREA AROUND
MIDNIGHT LAST NIGHT AND IS CONTINUING ITS SOUTHWARD TREK THROUGH
THE FORECAST AREA. ON THE AVERAGE...TEMPERATURES FELL ABOUT 20
DEGREES WITH THE FRONTAL PASSAGE.
TODAY...HIGH TEMPERATURES OCCURRED AROUND MIDNIGHT AND A STEADY
FALL OF TEMPERATURES CAN BE EXPECTED THROUGHOUT THE DAY AS STRONG
COLD ADVECTION CONTINUES. FOR HIGHS TODAY...HAVE GONE WITH
EXPECTED HIGHS AT 6 AM AS NO RECOVERY IS EXPECTED. IN
FACT...TEMPERATURES WILL FALL INTO THE LOW TEENS BY AFTERNOON.
SHORT WAVE ENERGY MOVING OVER NORTHWEST MONTANA THIS MORNING AND
WILL BEGIN TO IMPACT OUR AREA AROUND 12Z. FAIRLY GOOD LIFT ACROSS
THE REGION TODAY WITH FRONTOGENESIS INCREASING AS THE COLD AIR
DEEPENS. WINDS ALOFT WILL CONTINUE BACKING TO THE NORTH AND THIS
WILL BRING INCREASING UPSLOPE FLOW...ESPECIALLY TO THE FOOTHILLS.
MODELS ALSO SHOWING A BRIEF PERIOD OF ISENTROPIC LIFT MOVING IN BY
LATE MORNING. CROSS SECTIONS INDICATING DEEP MOISTURE FIELD MOVING
ACROSS THE AREA ALONG WITH A LOWERING DENDRITIC LAYER. THIS
FORCING WILL BRING PERIODS OF MODERATE SNOWFALL TODAY AND 2 TO 4
INCHES OVER THE PLAINS LOOKS ON TRACK AS DOES 3 TO 6 INCHES ALONG
THE FOOTHILLS. EXPECT 4 TO 8 INCHES IN THE MOUNTAINS BUT SNOW
AMOUNTS WILL REMAIN BELOW WARNING CRITERIA.
BIGGEST IMPACT TODAY WILL BE ICY ROADWAYS. WARM SURFACE
TEMPERATURES WILL MELT WITH INITIAL SNOWFALL THIS MORNING. AS
COLDER AIR CONTINUES TO ADVECT INTO THE AREA...ROADS WILL FREEZE
OVER AND THIS WILL CREATE DANGEROUS TRAVELING CONDITIONS. CURRENT
WINTER WEATHER ADVISORIES ON TRACK AND WILL KEEP IT GOING TODAY.
UPPER LEVEL FORCING AND COLD AIR WILL MOVE INTO NORTHERN WYOMING
THIS AFTERNOON. 2 TO 4 INCHES IS EXPECTED IN THE SHERIDAN AREA
ALONG WITH ICY ROAD CONDITIONS.
TONIGHT...SNOW WILL BE ENDING FROM NORTH TO SOUTH. CLOUDS WILL BE
DECREASING AND VERY COLD TEMPERATURES ARE EXPECTED. MOST AREAS
WILL SEE SINGLE DIGITS FOR OVERNIGHT LOWS WITH A FEW AREAS OVER
SOUTHEAST MONTANA POSSIBLY SLIPPING INTO THE SINGLE DIGITS BELOW
ZERO.
THURSDAY AND THURSDAY NIGHT...DRY BUT COLD CONDITIONS WILL
CONTINUE ACROSS THE AREA. TEMPERATURES WILL WARM SLIGHTLY AS
HEIGHTS ALOFT BEGIN TO INCREASE BUT WE ARE ONLY EXPECT HIGHS TO
REACH INTO THE LOW TO MID 20S. OVERNIGHT LOWS WILL BE IN THE
TEENS. RICHMOND
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
ONLY RELATIVELY MINOR CHANGES TO THE EXTENDED PERIOD AGAIN THIS
MORNING...MAINLY FOR COORDINATION PURPOSED. OVERALL THE STORY
REMAINS THE SAME WITH MAINLY DRY CONDITIONS PREVAILING ACROSS THE
REGION THROUGHOUT THE EXTENDED PERIOD. THERE WILL EB A GENERAL
WARMING TREND THROUGH ABOUT MONDAY...WHEN ANOTHER BATCH OF COOLER
AIR MOVES ACROSS THE REGION.
CURRENTLY THE ONLY CHANCE FOR PRECIP APPEARS TO BE FOR
FRIDAY...AS A REINFORCING PUSH OF COLD AIR PUSH EASTWARD OUT OF
THE REGION. ONCE PROGGED AS A DISCRETE PUSH OF COLD AIR ON
FRIDAY...THIS COLD PUSH APPEARS TO HAVE COMBINED WITH THE EXIT OF
THE COLD AIR FROM THE SHORT TERM PERIOD. THIS REINFORCING COLD
PUSH NOW PROGGED TO SLIP FURTHER TO THE EAST...WITH THE EXIT OF
THE PREVIOUS SYSTEM. HAVE COOLED EXTREME EAST SLIGHTLY...BUT KEPT
WEST WARMER...WITH DOWNSLOPE FLOW. PARED POPS BACK TO SLIGHT
CHANCE FOR FRIDAY AFTERNOON...BUT MAY BE TOO DRY WITHOUT A BREAK
IN COLD FOR SOME MELTING AND EVAPORATION TO OCCUR. WARMING TREND
PERSISTS THROUGH SUNDAY...WITH TEMPS BACK INTO THE 40S AND 50S.
ANOTHER SHORTWAVE WILL SWING THROUGH THE AREA SUNDAY NIGHT/MONDAY
AS AN UPPER LEVEL TROF SLIDES ACROSS SOUTHERN CANADA TOWARD THE
HUDSON BAY AREA. AT THIS TIME IT APPEARS TO BE A GLANCING
BLOW...WITH ONLY A SLIGHT COOL OFF AND LITTLE IN THE WAY OF ENERGY
FOR PRECIP PRODUCTION. HAVE CONTINUED WITH DRY FORECAST THROUGH
WEDNESDAY...WITH SLIGHTLY COOLER TEMPS FOR THE BEGINNING OF THE
WORK WEEK. AAG
&&
.AVIATION...
SNOW WILL CONTINUE TO OVERSPREAD THE REGION FROM THE NORTH AND
WEST. LOW CLOUDS AND SNOW WILL RESULT IN WIDESPREAD MVFR TO LIFR
FLIGHT CONDITIONS INTO THIS EVENING. SURFACE WINDS WILL REMAIN
NORTH TO NORTHEASTERLY AT ALL TERMINALS TODAY. STC
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 023 006/024 018/034 012/041 024/052 027/047 025/044
9/S 20/B 02/J 10/U 00/N 00/B 00/B
LVM 034 004/026 016/035 016/043 028/049 026/047 020/043
8/S 20/B 01/B 10/U 00/N 00/B 00/B
HDN 026 006/025 011/033 008/040 018/049 022/046 021/042
9/S 30/B 03/J 10/U 00/U 00/B 00/B
MLS 019 001/023 006/026 004/034 018/043 023/043 019/038
9/S 20/B 03/J 10/U 00/U 00/U 00/B
4BQ 028 003/022 005/028 002/036 019/045 022/044 020/039
8/S 52/J 03/J 10/U 00/U 00/U 00/B
BHK 022 002/021 006/024 004/029 017/042 020/042 016/035
9/S 40/B 03/J 10/B 00/U 00/U 00/B
SHR 033 007/024 004/036 010/042 022/048 023/047 022/043
7/S 72/J 02/J 10/U 00/U 00/B 00/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MST THIS EVENING
FOR ZONES 28>42-56>58-63>66.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 AM MST THURSDAY FOR
ZONE 99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
305 PM EST WED NOV 20 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHEAST UNITED STATES WILL MOVE OFF THE
COAST TONIGHT AND LEAD TO A SOUTHERLY FLOW OF MILDER AIR FOR
THURSDAY. A WARM FRONT WILL MOVE THROUGH THE REGION THURSDAY NIGHT
AND FRIDAY BRINGING SOME RAIN SHOWERS WITH IT. A STRONG COLD
FRONT WILL MOVE THROUGH THE REGION SATURDAY WHICH WILL USHER IN
MUCH COLDER AIR FOR SUNDAY AND EARLY NEXT WEEK. THIS COLD AIR
COULD GENERATE SIGNIFICANT LAKE EFFECT SNOWS IN THE LAKE EFFECT
SNOW BELTS OF NORTH CENTRAL NEW YORK.
&&
.NEAR TERM /THROUGH THURSDAY/...
HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S INTO THIS EVENING AS
THE UPPER LEVEL RDG AXIS SLOWLY MOVES E. EXPECT ONLY SOME PATCHY
CIRRUS AT TIMES WORKG OVER THE UPR LVL RDG AXIS WHICH WILL BE MOVG
OHVD THIS EVE. OTHERWISE FAIR WX THIS EVENING.
FOR OVERNIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12..12Z CMC AND RUC13 AS WELL AS THE LATEST 12Z GFS
ALL SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE
MIDDLE ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING
NORTHWARD REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS
LAYER FARTHER S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS
REACHING NRN PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM/GFS
AND CMC.
ON THURSDAY THERE WILL BE A SOUTHERLY RETURN FLOW SETTING UP AS
THE SFC HIGH IS OFFSHORE. THE 925 MB TO 850 MB WINDS WILL BE FROM
THE SOUTH AND BASED ON THE LATEST NAM...GFS AND CMC MODELS LL
MOISTURE WILL BE ON THE INCREASE THURSDAY AS CIRRUS AND MID CLDS
POUR IN FROM THE WEST AS HI LEVEL THERMAL ADVECTIONS BEGIN IN
ADVANCE OF THE NEXT SYSTEM. THEREFORE WILL HAVE INCREASING AMNTS
OF CLDS DURING THE DAY THURSDAY. LOOKS LIKE ANY PRECIP WILL HOLD
OFF B4 00Z FRI.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FOR THURSDAY NIGHT...AN UPPER LEVEL JET STREAK WITH THE NEXT
SYSTEM WILL PUSH INTO THE LOWER LAKES/UPPR OH VLLY AND SUPPORT A
SWRLY LLJ AT ARND 850 MB WHICH WILL LEAD TO A SHOT OF WAA AND
MOISTURE ADVTN INTO NY AND NRN PA. THIS WAA WILL LEAD TO A BATCH
OF LIGHT RAIN SPREADING ACRS MOST OF THE CWA BETWEEN 6Z AND
12Z FRI...WITH SOME LIGHTER PRECIP POTENTIALLY ARRIVING A TAD EARLIER
IN WRN NY. MODEL SOUNDING DATA SUGGESTS ALL RAIN SPREADING EWRD AS
THERE WILL BE NON-DIURNAL TEMP TRENDS WITH THE MIN/S OCCURRING IN
THU EVENING AND RISING TEMPS OVERNIGHT INTO FRI AM WHEN THE BULK OF
THE PRECIP ARRIVES.
AFTER THIS FIRST SHOT OF WAA RAIN SHRA PASSES...THERE WILL BE A
LULL IN THE RAINFALL FRI AM IN ADVANCE OF THE CD FRNT WHICH
REACHES WRN NY BY 18Z AND THEN CROSSES THE REST OF C NY/NE PA BY
FRI EVE. THERE WILL BE SHRA WITH THIS FRONT AND A LITTLE BEHIND IT. THEN
THERE WILL BE ANOTHER LULL IN THE PRECIP UNTIL THE NEXT WAVE
APPROACHES SAT PM WHICH WILL BE ASSCTD WITH A SFC LO AND THE TRUE
ARCTIC FRNT WHICH REACHES INTO THE ERN LAKES SAT PM. FOR SAT...IT
LOOKS LIKE BY AFTERNOON MOST OF THE CWA WILL SEE SN SHWRS AND
FLURRIES AS 850 MB TEMPS DROP TO -10C OR BLO. AGAIN THERE WILL BE
A NON-DIURNAL TEMP TREND SAT PM WITH STRG CAA. MAXES SHUD OCCUR
LATE MORNING SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
EXTENDED FORECAST BEGINS WITH A VERY COLD AIRMASS ACROSS THE
NORTHEAST AS A DEEP UPPER LEVEL TROF SWINGS THROUGH THE AREA. BOTH
THE GFS/ECMWF CONTINUE TO ADVERTISE T85 AROUND -16C/-18C FOR 18Z
SUN. THEY BOTH HAVE BEEN CONSISTENT WITH THIS COLD AIRMASS FOR
SEVERAL RUNS NOW INDICATING A HIGH LIKELY HOOD OF OCCURRENCE.
INITIALLY THE LOW LEVEL FLOW SATURDAY NIGHT LOOKS AROUND 290
DEGREES THEN SHIFTS MORE NORTHWEST AFTER 06Z AS A SECONDARY TROF
PASSES. ON SUNDAY, THE LOW LEVEL FLOW WILL BACK AS H85 RIDGE MOVES
THROUGH THE AREA. FOR SATURDAY NIGHT THROUGH SUNDAY WILL CONTINUE
TO ADVERTISE LIKELY POPS FOR LES PRIMARILY SOUTHEAST OF LAKE
ONTARIO. SNOW ACCUMS THROUGH THE PERIOD WILL LIKELY REACH SEVERAL
INCHES WITH A LAKE SNOW ADVISORY MOST LIKELY NEEDED SATURDAY NIGHT
INTO SUNDAY AS THE EVENT APPROACHES. A SHORT FETCH AND LIMITED
SYNOPTIC MOISTURE MAY LIMIT ACCUMS BUT THE AIRMASS IS VERY COLD FOR
THIS TIME OF THE YEAR.
MONDAY NIGHT INTO WEDNESDAY, A NORTHERN STREAM SYSTEM WILL MOVE
THROUGH THE UPPER GREAT LAKES AND ACROSS EASTERN CANADA. WILL
MENTION CHC/SLIGHT CHC POPS FOR SNOW SHOWERS. THE MEDIUM RANGE
MODELS HAVE HINTED AT A NORTHERN/SOUTHERN STREAM PHASING TUE INTO
WED WITH THE DEVELOPMENT OF A STRONG COAST LOW WHICH COULD IMPACT
THE FORECAST AREA. THE LATEST OPERATIONAL RUNS OF THE GFS/ECMWF
NOW SHOW THE SYSTEM REMAINING PRIMARILY EAST/SOUTH OF THE AREA. IT`S
STILL EARLY, SOMETHING TO WATCH.
TEMPS THROUGH THE PERIOD WILL BE AROUND 10-15 DEGREES BELOW NORMAL.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE IN THE VCNTY WILL MOVE TO THE EAST COAST AT THE END
OF THIS TAF PERIOD WHILE A COLD FRONT DROPS INTO THE UPPER GREAT
LAKES. IN GENERAL VFR CONDITIONS ARE EXPECTED TO CONTINUE. THROUGH
MID MORNING THURSDAY, JUST CI ACROSS THE TERMINALS WITH A MID
DECK DEVELOPING OVER THE AREA LATE IN THE TAF PERIOD.
MODELS ARE INDICATING THE POTENTIAL FOR A MARINE LAYER TOWARD
DAYBREAK ACROSS THE KAVP/KBGM TERMINALS. SINCE THE MODEL SOUNDINGS
DON`T INDICATE THIS POTENTIAL UNTIL ALMOST 12Z AND THE LAYER IS
VERY SHALLOW HAVE DECIDED TO INCLUDE JUST A SCATTERED MVFR LAYER
AT KBGM/KAVP BEGINNING AT 12Z.
LIGHT AND VARIABLE WINDS BECOMING SOUTHEAST AROUND 5 KNOTS
OVERNIGHT THEN SOUTHERLY AROUND 10 KNOTS ON THURSDAY.
OUTLOOK...
THURSDAY NIGHT INTO FRIDAY...RESTRICTIONS LIKELY FROM RAIN SHOWERS.
FRI NIGHT INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD
FRONT PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT SHSN...ESPECIALLY
CENTRAL NY TERMINALS.
SUNDAY NIGHT...VFR.
MONDAY...RESTRICTIONS POSSIBLE IN SNOW SHOWERS PRIMARILY NYS TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
142 PM EST WED NOV 20 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE NORTHEAST UNITED STATES WILL MOVE OFF THE
COAST TONIGHT AND LEAD TO A SOUTHERLY FLOW OF MILDER AIR FOR
THURSDAY. A WARM FRONT WILL MOVE THROUGH THE REGION THURSDAY NIGHT
AND FRIDAY BRINGING SOME RAIN SHOWERS WITH IT. A STRONG COLD
FRONT WILL MOVE THROUGH THE REGION SATURDAY WHICH WILL USHER IN
MUCH COLDER AIR FOR SUNDAY AND EARLY NEXT WEEK. THIS COLD AIR
COULD GENERATE SIGNIFICANT LAKE EFFECT SNOWS IN THE LAKE EFFECT
SNOW BELTS OF NORTH CENTRAL NEW YORK.
&&
.NEAR TERM /THROUGH THURSDAY/...
HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S INTO THIS EVENING AS
THE UPPER LEVEL RDG AXIS SLOWLY MOVES E. EXPECT ONLY SOME PATCHY
CIRRUS AT TIMES WORKG OVER THE UPR LVL RDG AXIS WHICH WILL BE MOVG
OHVD THIS EVE. OTHERWISE FAIR WX THIS EVENING.
FOR OVERNIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12..12Z CMC AND RUC13 AS WELL AS THE LATEST 12Z GFS
ALL SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE
MIDDLE ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING
NORTHWARD REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS
LAYER FARTHER S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS
REACHING NRN PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM/GFS
AND CMC.
ON THURSDAY THERE WILL BE A SOUTHERLY RETURN FLOW SETTING UP AS
THE SFC HIGH IS OFFSHORE. THE 925 MB TO 850 MB WINDS WILL BE FROM
THE SOUTH AND BASED ON THE LATEST NAM...GFS AND CMC MODELS LL
MOISTURE WILL BE ON THE INCREASE THURSDAY AS CIRRUS AND MID CLDS
POUR IN FROM THE WEST AS HI LEVEL THERMAL ADVECTIONS BEGIN IN
ADVANCE OF THE NEXT SYSTEM. THEREFORE WILL HAVE INCREASING AMNTS
OF CLDS DURING THE DAY THURSDAY. LOOKS LIKE ANY PRECIP WILL HOLD
OFF B4 00Z FRI.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH SATURDAY/...
FOR THURSDAY NIGHT...AN UPPER LEVEL JET STREAK WITH THE NEXT
SYSTEM WILL PUSH INTO THE LOWER LAKES/UPPR OH VLLY AND SUPPORT A
SWRLY LLJ AT ARND 850 MB WHICH WILL LEAD TO A SHOT OF WAA AND
MOISTURE ADVTN INTO NY AND NRN PA. THIS WAA WILL LEAD TO A BATCH
OF LIGHT RAIN SPREADING ACRS MOST OF THE CWA BETWEEN 6Z AND
12Z FRI...WITH SOME LIGHTER PRECIP POTENTIALLY ARRIVING A TAD EARLIER
IN WRN NY. MODEL SOUNDING DATA SUGGESTS ALL RAIN SPREADING EWRD AS
THERE WILL BE NON-DIURNAL TEMP TRENDS WITH THE MIN/S OCCURRING IN
THU EVENING AND RISING TEMPS OVERNIGHT INTO FRI AM WHEN THE BULK OF
THE PRECIP ARRIVES.
AFTER THIS FIRST SHOT OF WAA RAIN SHRA PASSES...THERE WILL BE A
LULL IN THE RAINFALL FRI AM IN ADVANCE OF THE CD FRNT WHICH
REACHES WRN NY BY 18Z AND THEN CROSSES THE REST OF C NY/NE PA BY
FRI EVE. THERE WILL BE SHRA WITH THIS FRONT AND A LITTLE BEHIND IT. THEN
THERE WILL BE ANOTHER LULL IN THE PRECIP UNTIL THE NEXT WAVE
APPROACHES SAT PM WHICH WILL BE ASSCTD WITH A SFC LO AND THE TRUE
ARCTIC FRNT WHICH REACHES INTO THE ERN LAKES SAT PM. FOR SAT...IT
LOOKS LIKE BY AFTERNOON MOST OF THE CWA WILL SEE SN SHWRS AND
FLURRIES AS 850 MB TEMPS DROP TO -10C OR BLO. AGAIN THERE WILL BE
A NON-DIURNAL TEMP TREND SAT PM WITH STRG CAA. MAXES SHUD OCCUR
LATE MORNING SAT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH TUESDAY/...
115 PM TUE UPDATE...
GENERALLY USED WPC GUIDANCE EXCEPT FOR LOCALIZED ENHANCEMENTS TO
POP AND SKY GRIDS FOR WHEN LAKE EFFECT SNOW WILL BE FAVORABLE.
INTERESTING PATTERN TAKING SHAPE WITH INCREASING CONFIDENCE FOR
SOLID SHOT OF ARCTIC AIR /COLDEST OF SEASON SO FAR/ DURING SECOND
HALF OF WEEKEND...AND FOR LAKE EFFECT SNOW. DETAILS OF THAT SNOW
OF COURSE WILL BE RESOLVED IN COMING DAYS...BUT IN THE BIG PICTURE
IT LOOKS FAVORABLE WITHIN OUR GENERAL AREA AND FORECAST HAS BEEN
ADJUSTED ACCORDINGLY WITH BEST CHANCES SUNDAY IN CENTRAL NEW YORK.
BEFORE THEN HOWEVER...TIMING OF INITIAL COLD FRONT LOOKS LIKELY
FOR SOMETIME FRIDAY NIGHT/EARLY SATURDAY. FRONTAL PRECIPITATION
WILL PROBABLY BE MAINLY RAIN. COLD AIR ADVECTION OCCURS DURING THE
DAY...ALLOWING LINGERING RAIN SHOWERS TO MIX WITH SNOW...THOUGH
AMOUNTS PROBABLY LIMITED BY THEN DUE TO DRY SLOTTING /LOSS OF
DEEPER MOISTURE/. ARCTIC FRONT WILL THEN BLAST THROUGH SOMETIME
SATURDAY NIGHT...PLUMMETING 850MB TEMPERATURES INTO AT LEAST THE
MID TEENS BELOW ZERO ON SUNDAY. WITH THE ARCTIC AIR MASS APPEARING
TO ADVECT IN FROM WNW INSTEAD OF THE NORTHERLY DIRECTION...AND
WITH THE DENDRITIC GROWTH LAYER BECOMING COMFORTABLY CONTAINED IN
THE LOWEST 8 KFT AGL...IT IS A FAVORABLE SET UP FOR ACCUMULATING
LAKE EFFECT SNOW INCLUDING UPSTREAM LAKE-TO-LAKE CONNECTIONS
SUNDAY INTO PERHAPS SUNDAY NIGHT.
IT HAS BEEN COMMON SO FAR THIS SEASON FOR AN INITIALLY VERY COLD
AIR MASS IN THE MODELS...TO MODERATE AS THE EVENT GETS CLOSER TO
THE POINT THAT IT IS NOT QUITE AS COLD AS ORIGINALLY ANTICIPATED
ONCE IT ARRIVES. HOWEVER...IN THIS CASE...THE MODELS HAVE
INDICATED THE ARCTIC AIR FOR AT LEAST A FEW RUNS AND ARE
MAINTAINING ITS MAGNITUDE IF NOT TRENDING EVEN SLIGHTLY COLDER.
BOTH 12Z GFS AND 00Z ECMWF DIVE 1000-500MB THICKNESSES BELOW 510
DECAMETER RANGE. GFS GUIDANCE TEMPERATURES HAVE NOW TRENDED
TOWARDS THE VERY COLD ECMWF GUIDANCE VALUES. WE NOW EXPECT MOST
LOCATIONS NOT TO GET OUT OF THE 20S FOR HIGHS SUNDAY.
DRY SURFACE RIDGE MONDAY WITH WARM AIR ADVECTION ALOFT...BUT
LIKELY MUCH MORE MUTED AT THE SURFACE AS WOULD BE TYPICAL ON BACK
SIDE OF ARCTIC AIR MASS. SO AFTER MAINLY TEENS FOR LOWS SUNDAY
NIGHT...ONLY UPPER 20S TO MID 30S ANTICIPATED FOR HIGHS MONDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE IN THE VCNTY WILL MOVE TO THE EAST COAST AT THE END
OF THIS TAF PERIOD WHILE A COLD FRONT DROPS INTO THE UPPER GREAT
LAKES. IN GENERAL VFR CONDITIONS ARE EXPECTED TO CONTINUE. THROUGH
MID MORNING THURSDAY, JUST CI ACROSS THE TERMINALS WITH A MID
DECK DEVELOPING OVER THE AREA LATE IN THE TAF PERIOD.
MODELS ARE INDICATING THE POTENTIAL FOR A MARINE LAYER TOWARD
DAYBREAK ACROSS THE KAVP/KBGM TERMINALS. SINCE THE MODEL SOUNDINGS
DON`T INDICATE THIS POTENTIAL UNTIL ALMOST 12Z AND THE LAYER IS
VERY SHALLOW HAVE DECIDED TO INCLUDE JUST A SCATTERED MVFR LAYER
AT KBGM/KAVP BEGINNING AT 12Z.
LIGHT AND VARIABLE WINDS BECOMING SOUTHEAST AROUND 5 KNOTS
OVERNIGHT THEN SOUTHERLY AROUND 10 KNOTS ON THURSDAY.
OUTLOOK...
THURSDAY NIGHT INTO FRIDAY...RESTRICTIONS LIKELY FROM RAIN SHOWERS.
FRI NIGHT INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD
FRONT PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT SHSN...ESPECIALLY
CENTRAL NY TERMINALS.
SUNDAY NIGHT...VFR.
MONDAY...RESTRICTIONS POSSIBLE IN SNOW SHOWERS PRIMARILY NYS TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...MDP
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
105 PM EST WED NOV 20 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL RESULT IN FAIR WEATHER AND
NEAR SEASONAL TEMPERATURES FOR THIS AFTERNOON. THIS HIGH WILL
SHIFT OFF THE NORTHEAST COAST TONIGHT AND ALLOW FOR A SOUTHERLY
FLOW OF AIR TO ONCE AGAIN RETURN TO THE AREA. THIS WILL LEAD TO
SLIGHTLY WARMER TEMPERATURES FOR THURSDAY. THE NEXT CHANCE FOR
ORGANIZED RAINFALL WILL ARRIVE THURSDAY NIGHT AS A WARM FRONT
LIFTS NORTH ACROSS THE REGION...WITH RAIN CHANCES FURTHER
INCREASING BOTH FRIDAY AND FRIDAY NIGHT AS A STRONG COLD FRONT
APPROACHES FROM THE WEST. MUCH COLDER AIR WILL THEN SETTLE INTO
THE REGION FOR THE UPCOMING WEEKEND WITH DEVELOPING LAKE EFFECT
SNOW SHOWERS EXPECTED DOWNWIND OF LAKE ONTARIO.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S THIS AFTERNOON AND
EVENING AS THE UPPER LEVEL RDG AXIS SLOWLY MOVES E IN TANDEM WITH
THE LARGE SFC HIGH OVHD. SOME CIRRUS WILL ADVECT OVER THE UPR RDG
AXIS LATER THIS AFTERNOON. IN ADDTN...THERE WAS AN UPPER LEVEL
WAVE MOVING OFF THE MID ATLANTIC COAST THAT HAD SPREAD SOME CIRRUS
TO OUR AREA THIS MORNING. THIS CIRRUS WILL TRACK E OF THE REGION
THIS PM. THE LL/S ARE EXTREMELY DRY AND WE DON/T EXPECT ANY CU OR
SC FORMATION WITH INSOLATION.
FOR TONIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12 AND RUC13 AS WELL AS THE LATEST 12Z GFS ALL
SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE MIDDLE
ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING NORTHWARD
REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS LAYER FARTHER
S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS REACHING NRN
PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM AND GFS.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EASTERN SEABOARD ON
THURSDAY WITH SOUTHEAST LOW-LEVEL FLOW PREVAILING OVER MUCH OF
OUR REGION. CLOUDS WILL BE ON THE INCREASE THROUGH THE AFTERNOON
AS FLOW ACROSS THE OHIO VALLEY AND UPPER MIDWEST BEGINS TO
INCREASE AS A STRONG COLD FRONT /BLUE NORTHER/ DROPS ACROSS THE
CENTRAL AND SOUTHERN PLAINS. THIS WILL ULTIMATELY MEAN TEMPS ON
THURSDAY WILL BE A FEW DEGREES WARMER THAN TODAY...WITH LWR TO
MIDDLE 40S EXPECTED REGION-WIDE.
FCST BECOMES A BIT MORE INTERESTING THURSDAY NIGHT AS A WEAK AREA
OF LOW PRESSURE BEGINS MOVING NORTHEAST ALONG A FRONTAL BOUNDARY
DROPPING SOUTH THROUGH THE UPPER MIDWEST/WESTERN GREAT LAKES. AS
THIS FEATURE PASSES TO OUR NORTH AND WEST...A CORRESPONDING WARM
FRONT WILL BEGIN LIFTING NORTH TOWARDS OUR REGION. STRENGTHENING
SOUTHWESTERLY 850 FLOW WILL CREATE MODEST ISENTROPIC ASCENT ALONG
THE 295-300K THETA SURFACES WHICH WILL UNDOUBTEDLY INCREASE CLOUD
COVERAGE WHILE ALSO PROVIDING THE NEXT OPPORTUNITY FOR ORGANIZED
RAINFALL. FOR THURSDAY NIGHT...BEST ISENTROPIC ASCENT WILL BE
CONFINED TO AREAS WEST OF THE INTERSTATE 81 CORRIDOR WHERE HIGH
CHC TO LOW LIKELY POPS HAVE BEEN OFFERED. FURTHER SOUTH AND
EAST...MUCH DRIER AIR WILL BE IN PLACE THANKS TO ANCHORED HIGH
PRESSURE AND ASSOCIATED RIDGE AXIS EXTENDING DOWN THE IMMEDIATE
EASTERN SEABOARD.
WARM FRONT TO CONTINUE LIFTING THROUGH THE REGION EARLY FRIDAY
MORNING BEFORE CLEARING AND PLACING MUCH OF OUR AREA IN THE WARM
SECTOR TEMPORARILY. BEST CHANCES FOR RAIN WILL BE DURING THE AM
HRS AS FEATURE LIFTS NORTH...WITH DECREASING CHANCES EXPECTED BY
AFTERNOON.
FORECAST UNCERTAINLY BEGINS TO REAR ITS UGLY HEAD BY FRI EVENING
AS MAIN COLD FRONT WILL BEGIN PASSING THROUGH THE REGION. DESPITE
OVERALL MODEL AGREEMENT THAT A FRONT WILL PASS...THE GFS AND NAM
REMAIN UP TO 6+ HRS OFF ON TIMING...WITH THE FORMER TRENDING THE
SLOWEST AND HOLDING OFF PASSAGE UNTIL AFTER 00Z. THE NAM ON THE
OTHER HAND WOULD SUGGEST A PASSAGE FRI AFTERNOON. QUICK LOOK AT A
POOR-MAN`S ENSEMBLE WOULD SUGGEST THE NAM MODEL IS THE OUTLIER AS
THE ECMWF/CMC/AND UKMET ALL AGREE FRONT WILL PASS A LITTLE LATER
THAN WHAT THE NAM IS OFFERING. THAT SAID...HAVE INCREASED POPS
INTO SAT MORNING WITH LIKELY POPS OFFERED REGION-WIDE. AS COLD
AIR USHERS INTO THE REGION...RAIN MAY MIX WITH SNOW BEFORE ALL
ACTIVITY PASSES OFF TO THE SOUTH AND EAST AFTER 12Z.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
115 PM TUE UPDATE...
GENERALLY USED WPC GUIDANCE EXCEPT FOR LOCALIZED ENHANCEMENTS TO
POP AND SKY GRIDS FOR WHEN LAKE EFFECT SNOW WILL BE FAVORABLE.
INTERESTING PATTERN TAKING SHAPE WITH INCREASING CONFIDENCE FOR
SOLID SHOT OF ARCTIC AIR /COLDEST OF SEASON SO FAR/ DURING SECOND
HALF OF WEEKEND...AND FOR LAKE EFFECT SNOW. DETAILS OF THAT SNOW
OF COURSE WILL BE RESOLVED IN COMING DAYS...BUT IN THE BIG PICTURE
IT LOOKS FAVORABLE WITHIN OUR GENERAL AREA AND FORECAST HAS BEEN
ADJUSTED ACCORDINGLY WITH BEST CHANCES SUNDAY IN CENTRAL NEW YORK.
BEFORE THEN HOWEVER...TIMING OF INITIAL COLD FRONT LOOKS LIKELY
FOR SOMETIME FRIDAY NIGHT/EARLY SATURDAY. FRONTAL PRECIPITATION
WILL PROBABLY BE MAINLY RAIN. COLD AIR ADVECTION OCCURS DURING THE
DAY...ALLOWING LINGERING RAIN SHOWERS TO MIX WITH SNOW...THOUGH
AMOUNTS PROBABLY LIMITED BY THEN DUE TO DRY SLOTTING /LOSS OF
DEEPER MOISTURE/. ARCTIC FRONT WILL THEN BLAST THROUGH SOMETIME
SATURDAY NIGHT...PLUMMETING 850MB TEMPERATURES INTO AT LEAST THE
MID TEENS BELOW ZERO ON SUNDAY. WITH THE ARCTIC AIR MASS APPEARING
TO ADVECT IN FROM WNW INSTEAD OF THE NORTHERLY DIRECTION...AND
WITH THE DENDRITIC GROWTH LAYER BECOMING COMFORTABLY CONTAINED IN
THE LOWEST 8 KFT AGL...IT IS A FAVORABLE SET UP FOR ACCUMULATING
LAKE EFFECT SNOW INCLUDING UPSTREAM LAKE-TO-LAKE CONNECTIONS
SUNDAY INTO PERHAPS SUNDAY NIGHT.
IT HAS BEEN COMMON SO FAR THIS SEASON FOR AN INITIALLY VERY COLD
AIR MASS IN THE MODELS...TO MODERATE AS THE EVENT GETS CLOSER TO
THE POINT THAT IT IS NOT QUITE AS COLD AS ORIGINALLY ANTICIPATED
ONCE IT ARRIVES. HOWEVER...IN THIS CASE...THE MODELS HAVE
INDICATED THE ARCTIC AIR FOR AT LEAST A FEW RUNS AND ARE
MAINTAINING ITS MAGNITUDE IF NOT TRENDING EVEN SLIGHTLY COLDER.
BOTH 12Z GFS AND 00Z ECMWF DIVE 1000-500MB THICKNESSES BELOW 510
DECAMETER RANGE. GFS GUIDANCE TEMPERATURES HAVE NOW TRENDED
TOWARDS THE VERY COLD ECMWF GUIDANCE VALUES. WE NOW EXPECT MOST
LOCATIONS NOT TO GET OUT OF THE 20S FOR HIGHS SUNDAY.
DRY SURFACE RIDGE MONDAY WITH WARM AIR ADVECTION ALOFT...BUT
LIKELY MUCH MORE MUTED AT THE SURFACE AS WOULD BE TYPICAL ON BACK
SIDE OF ARCTIC AIR MASS. SO AFTER MAINLY TEENS FOR LOWS SUNDAY
NIGHT...ONLY UPPER 20S TO MID 30S ANTICIPATED FOR HIGHS MONDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
HIGH PRESSURE IN THE VCNTY WILL MOVE TO THE EAST COAST AT THE END
OF THIS TAF PERIOD WHILE A COLD FRONT DROPS INTO THE UPPER GREAT
LAKES. IN GENERAL VFR CONDITIONS ARE EXPECTED TO CONTINUE. THROUGH
MID MORNING THURSDAY, JUST CI ACROSS THE TERMINALS WITH A MID
DECK DEVELOPING OVER THE AREA LATE IN THE TAF PERIOD.
MODELS ARE INDICATING THE POTENTIAL FOR A MARINE LAYER TOWARD
DAYBREAK ACROSS THE KAVP/KBGM TERMINALS. SINCE THE MODEL SOUNDINGS
DON`T INDICATE THIS POTENTIAL UNTIL ALMOST 12Z AND THE LAYER IS
VERY SHALLOW HAVE DECIDED TO INCLUDE JUST A SCATTERED MVFR LAYER
AT KBGM/KAVP BEGINNING AT 12Z.
LIGHT AND VARIABLE WINDS BECOMING SOUTHEAST AROUND 5 KNOTS
OVERNIGHT THEN SOUTHERLY AROUND 10 KNOTS ON THURSDAY.
OUTLOOK...
THURSDAY NIGHT INTO FRIDAY...RESTRICTIONS LIKELY FROM RAIN SHOWERS.
FRI NIGHT INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD
FRONT PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT SHSN...ESPECIALLY
CENTRAL NY TERMINALS.
SUNDAY NIGHT...VFR.
MONDAY...RESTRICTIONS POSSIBLE IN SNOW SHOWERS PRIMARILY NYS TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...CMG
LONG TERM...MDP
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1210 PM EST WED NOV 20 2013
.SYNOPSIS...
HIGH PRESSURE OVER THE REGION WILL RESULT IN FAIR WEATHER AND
NEAR SEASONAL TEMPERATURES FOR THIS AFTERNOON. THIS HIGH WILL
SHIFT OFF THE NORTHEAST COAST TONIGHT AND ALLOW FOR A SOUTHERLY
FLOW OF AIR TO ONCE AGAIN RETURN TO THE AREA. THIS WILL LEAD TO
SLIGHTLY WARMER TEMPERATURES FOR THURSDAY. THE NEXT CHANCE FOR
ORGANIZED RAINFALL WILL ARRIVE THURSDAY NIGHT AS A WARM FRONT
LIFTS NORTH ACROSS THE REGION...WITH RAIN CHANCES FURTHER
INCREASING BOTH FRIDAY AND FRIDAY NIGHT AS A STRONG COLD FRONT
APPROACHES FROM THE WEST. MUCH COLDER AIR WILL THEN SETTLE INTO
THE REGION FOR THE UPCOMING WEEKEND WITH DEVELOPING LAKE EFFECT
SNOW SHOWERS EXPECTED DOWNWIND OF LAKE ONTARIO.
&&
.NEAR TERM /THROUGH TONIGHT/...
HIGH PRESSURE WILL DOMINATE THE NORTHEAST U.S THIS AFTERNOON AND
EVENING AS THE UPPER LEVEL RDG AXIS SLOWLY MOVES E IN TANDEM WITH
THE LARGE SFC HIGH OVHD. SOME CIRRUS WILL ADVECT OVER THE UPR RDG
AXIS LATER THIS AFTERNOON. IN ADDTN...THERE WAS AN UPPER LEVEL
WAVE MOVING OFF THE MID ATLANTIC COAST THAT HAD SPREAD SOME CIRRUS
TO OUR AREA THIS MORNING. THIS CIRRUS WILL TRACK E OF THE REGION
THIS PM. THE LL/S ARE EXTREMELY DRY AND WE DON/T EXPECT ANY CU OR
SC FORMATION WITH INSOLATION.
FOR TONIGHT...THE SFC HI WORKS E OVER ERN NEW ENGLAND WITH THE
UPPER LEVEL RDG AXIS OVHD. CIRRUS WILL CONT TO SPILL OVER THE RDG
ALOFT. THE NAM12 AND RUC13 AS WELL AS THE LATEST 12Z GFS ALL
SUGGEST A MARINE LAYER OF LOW CLOUDS FORMING AGAIN IN THE MIDDLE
ATLANTIC STATES TONIGHT. THE GFS/NAM HAS THIS LAYER WORKING NORTHWARD
REACHING FAR NRN PA BY 12Z THU. THE RAP AT 9Z HAS THIS LAYER FARTHER
S THAN THE GFS AND NAM. FOR NOW WILL HAVE SOME CLDS REACHING NRN
PA BY 12Z AS PER PREVIOUS FORECAST AND LATEST NAM AND GFS.
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL REMAIN ANCHORED OVER THE EASTERN SEABOARD ON
THURSDAY WITH SOUTHEAST LOW-LEVEL FLOW PREVAILING OVER MUCH OF
OUR REGION. CLOUDS WILL BE ON THE INCREASE THROUGH THE AFTERNOON
AS FLOW ACROSS THE OHIO VALLEY AND UPPER MIDWEST BEGINS TO
INCREASE AS A STRONG COLD FRONT /BLUE NORTHER/ DROPS ACROSS THE
CENTRAL AND SOUTHERN PLAINS. THIS WILL ULTIMATELY MEAN TEMPS ON
THURSDAY WILL BE A FEW DEGREES WARMER THAN TODAY...WITH LWR TO
MIDDLE 40S EXPECTED REGION-WIDE.
FCST BECOMES A BIT MORE INTERESTING THURSDAY NIGHT AS A WEAK AREA
OF LOW PRESSURE BEGINS MOVING NORTHEAST ALONG A FRONTAL BOUNDARY
DROPPING SOUTH THROUGH THE UPPER MIDWEST/WESTERN GREAT LAKES. AS
THIS FEATURE PASSES TO OUR NORTH AND WEST...A CORRESPONDING WARM
FRONT WILL BEGIN LIFTING NORTH TOWARDS OUR REGION. STRENGTHENING
SOUTHWESTERLY 850 FLOW WILL CREATE MODEST ISENTROPIC ASCENT ALONG
THE 295-300K THETA SURFACES WHICH WILL UNDOUBTEDLY INCREASE CLOUD
COVERAGE WHILE ALSO PROVIDING THE NEXT OPPORTUNITY FOR ORGANIZED
RAINFALL. FOR THURSDAY NIGHT...BEST ISENTROPIC ASCENT WILL BE
CONFINED TO AREAS WEST OF THE INTERSTATE 81 CORRIDOR WHERE HIGH
CHC TO LOW LIKELY POPS HAVE BEEN OFFERED. FURTHER SOUTH AND
EAST...MUCH DRIER AIR WILL BE IN PLACE THANKS TO ANCHORED HIGH
PRESSURE AND ASSOCIATED RIDGE AXIS EXTENDING DOWN THE IMMEDIATE
EASTERN SEABOARD.
WARM FRONT TO CONTINUE LIFTING THROUGH THE REGION EARLY FRIDAY
MORNING BEFORE CLEARING AND PLACING MUCH OF OUR AREA IN THE WARM
SECTOR TEMPORARILY. BEST CHANCES FOR RAIN WILL BE DURING THE AM
HRS AS FEATURE LIFTS NORTH...WITH DECREASING CHANCES EXPECTED BY
AFTERNOON.
FORECAST UNCERTAINLY BEGINS TO REAR ITS UGLY HEAD BY FRI EVENING
AS MAIN COLD FRONT WILL BEGIN PASSING THROUGH THE REGION. DESPITE
OVERALL MODEL AGREEMENT THAT A FRONT WILL PASS...THE GFS AND NAM
REMAIN UP TO 6+ HRS OFF ON TIMING...WITH THE FORMER TRENDING THE
SLOWEST AND HOLDING OFF PASSAGE UNTIL AFTER 00Z. THE NAM ON THE
OTHER HAND WOULD SUGGEST A PASSAGE FRI AFTERNOON. QUICK LOOK AT A
POOR-MAN`S ENSEMBLE WOULD SUGGEST THE NAM MODEL IS THE OUTLIER AS
THE ECMWF/CMC/AND UKMET ALL AGREE FRONT WILL PASS A LITTLE LATER
THAN WHAT THE NAM IS OFFERING. THAT SAID...HAVE INCREASED POPS
INTO SAT MORNING WITH LIKELY POPS OFFERED REGION-WIDE. AS COLD
AIR USHERS INTO THE REGION...RAIN MAY MIX WITH SNOW BEFORE ALL
ACTIVITY PASSES OFF TO THE SOUTH AND EAST AFTER 12Z.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
115 PM TUE UPDATE...
GENERALLY USED WPC GUIDANCE EXCEPT FOR LOCALIZED ENHANCEMENTS TO
POP AND SKY GRIDS FOR WHEN LAKE EFFECT SNOW WILL BE FAVORABLE.
INTERESTING PATTERN TAKING SHAPE WITH INCREASING CONFIDENCE FOR
SOLID SHOT OF ARCTIC AIR /COLDEST OF SEASON SO FAR/ DURING SECOND
HALF OF WEEKEND...AND FOR LAKE EFFECT SNOW. DETAILS OF THAT SNOW
OF COURSE WILL BE RESOLVED IN COMING DAYS...BUT IN THE BIG PICTURE
IT LOOKS FAVORABLE WITHIN OUR GENERAL AREA AND FORECAST HAS BEEN
ADJUSTED ACCORDINGLY WITH BEST CHANCES SUNDAY IN CENTRAL NEW YORK.
BEFORE THEN HOWEVER...TIMING OF INITIAL COLD FRONT LOOKS LIKELY
FOR SOMETIME FRIDAY NIGHT/EARLY SATURDAY. FRONTAL PRECIPITATION
WILL PROBABLY BE MAINLY RAIN. COLD AIR ADVECTION OCCURS DURING THE
DAY...ALLOWING LINGERING RAIN SHOWERS TO MIX WITH SNOW...THOUGH
AMOUNTS PROBABLY LIMITED BY THEN DUE TO DRY SLOTTING /LOSS OF
DEEPER MOISTURE/. ARCTIC FRONT WILL THEN BLAST THROUGH SOMETIME
SATURDAY NIGHT...PLUMMETING 850MB TEMPERATURES INTO AT LEAST THE
MID TEENS BELOW ZERO ON SUNDAY. WITH THE ARCTIC AIR MASS APPEARING
TO ADVECT IN FROM WNW INSTEAD OF THE NORTHERLY DIRECTION...AND
WITH THE DENDRITIC GROWTH LAYER BECOMING COMFORTABLY CONTAINED IN
THE LOWEST 8 KFT AGL...IT IS A FAVORABLE SET UP FOR ACCUMULATING
LAKE EFFECT SNOW INCLUDING UPSTREAM LAKE-TO-LAKE CONNECTIONS
SUNDAY INTO PERHAPS SUNDAY NIGHT.
IT HAS BEEN COMMON SO FAR THIS SEASON FOR AN INITIALLY VERY COLD
AIR MASS IN THE MODELS...TO MODERATE AS THE EVENT GETS CLOSER TO
THE POINT THAT IT IS NOT QUITE AS COLD AS ORIGINALLY ANTICIPATED
ONCE IT ARRIVES. HOWEVER...IN THIS CASE...THE MODELS HAVE
INDICATED THE ARCTIC AIR FOR AT LEAST A FEW RUNS AND ARE
MAINTAINING ITS MAGNITUDE IF NOT TRENDING EVEN SLIGHTLY COLDER.
BOTH 12Z GFS AND 00Z ECMWF DIVE 1000-500MB THICKNESSES BELOW 510
DECAMETER RANGE. GFS GUIDANCE TEMPERATURES HAVE NOW TRENDED
TOWARDS THE VERY COLD ECMWF GUIDANCE VALUES. WE NOW EXPECT MOST
LOCATIONS NOT TO GET OUT OF THE 20S FOR HIGHS SUNDAY.
DRY SURFACE RIDGE MONDAY WITH WARM AIR ADVECTION ALOFT...BUT
LIKELY MUCH MORE MUTED AT THE SURFACE AS WOULD BE TYPICAL ON BACK
SIDE OF ARCTIC AIR MASS. SO AFTER MAINLY TEENS FOR LOWS SUNDAY
NIGHT...ONLY UPPER 20S TO MID 30S ANTICIPATED FOR HIGHS MONDAY.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
HIPRES OVRHD CNTRL NY AND NEPA WILL BRING MAINLY CLR SKIES AND DRY
AIR THRU THE TAF PD. WINDS WILL BE VRBL THIS MRNG...THAN LESS THAN
10 MPH FROM THE EAST THRU THE DAY INTO THE EVENING.
OUTLOOK...
THU...VFR.
FRI INTO SAT...RESTRICTIONS POSSIBLE FROM SHRA...AS A COLD FRONT
PASSES THROUGH THE AREA.
SAT NGT AND SUN...RESTRICTIONS LIKELY FROM LAKE EFFECT SHSN...ESPECIALLY
CENTRAL NY TERMINALS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...CMG
LONG TERM...MDP
AVIATION...DGM
AREA FORECAST DISCUSSION
NWS BISMARCK ND
447 PM CST WED NOV 20 2013
.UPDATE...
ISSUED AT 447 PM CST WED NOV 20 2013
QUICK UPDATE TO EXPAND THE WINTER WEATHER ADVISORY INTO
RENVILLE...TOWNER...BOTTINEAU...PIERCE AND ROLETTE COUNTIES.
HEAVY BANDED SNOW IS EXPECTED TO RESULT IN 3 TO 5 INCHES OF SNOW
FOR THESE AREAS WITH VISIBILITIES NEAR ONE QUARTER OF A MILE.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
LATEST RADAR AND WEATHER CAMERAS INDICATE SNOW FROM WEST CENTRAL
INTO NORTH CENTRAL NORTH DAKOTA. SNOW HAS BEEN HEAVY AT TIMES WITH
VISIBILITY DOWN TO A QUARTER. LATEST REPORTS AND ESTIMATES INDICATE
1-2 INCHES HAS FALLEN FROM WILLISTON TO DICKINSON. LIKELY SOME
HIGHER AMOUNTS IN A PERSISTENT BAND ACROSS MAINLY MCKENZIE COUNTY.
THIS BAND HAS BECOMING MORE ENHANCED ACROSS MOUNTRAIL INTO WARD
COUNTY IN THE PAST HOUR.
EXPECT ANOTHER 2 TO 4 HOURS OF LIGHT TO MODERATE SNOW IN THE
ADVISORY AREA...BEFORE SHIFTING FARTHER SOUTH AND EAST. 12 UTC
MODEL GUIDANCE AND THE LATEST MESOSCALE RAP AND HRRR SHOW
PRECIPITATION ENDING QUICKLY AROUND 00 UTC IN WESTERN NORTH DAKOTA
AS BEST FRONTOGENETICAL FORCING SHIFTS INTO CENTRAL NORTH DAKOTA.
THIS SHOULD PUT AN END TO ACCUMULATING SNOW OVER THE ADVISORY AREA
BY MID EVENING. CURRENT HAZARD GOES UNTIL 10 PM AND EVENING SHIFT
CAN CANCEL EARLY IF NEEDED.
BEST SNOW CHANCES ARE OVER CENTRAL NORTH DAKOTA THIS EVENING. AND
ACCUMULATIONS OF AROUND AN INCH ARE POSSIBLE OVER THE SOUTH
CENTRAL AND FAR SOUTHWEST...FROM BOWMAN AND HETTINGER TO BISMARCK
AND JAMESTOWN. LESSER AMOUNTS...UNDER AN INCH ARE EXPECTED FROM
SELFRIDGE TO LAMOURE AND OAKES. MODEL SOUNDINGS INDICATE WARM
TEMPERATURES ALOFT IN THE FAR SOUTH CENTRAL...THUS HAVE INCLUDED A
MENTION OF MIXED PRECIPITATION SOUTH OF BISMARCK TO THE SOUTHERN
JAMES RIVER VALLEY.
PRECIPITATION ENDS QUICKLY IN THE CENTRAL AS THE UPPER TROUGH
TRANSLATES INTO THE AREA LATE TONIGHT. THEN WE ARE LOOKING AT VERY
COLD TEMPERATURES AND WIND CHILLS LATE TONIGHT AND THURSDAY. WIND
CHILLS FROM 10 BELOW SOUTH TO 20 BELOW NORTHWEST CAN BE EXPECTED
EARLY THURSDAY MORNING.
THURSDAY IS EXPECTED TO BE DRY BUT COLD WITH HIGHS OF 10 TO 20 ABOVE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE COLDEST AIR OF THE
SEASON THUS FAR FOR FRIDAY NIGHT INTO SATURDAY MORNING.
THE 12 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A WEAK
CLIPPER SYSTEM PROPAGATING NEAR THE INTERNATIONAL BORDER THURSDAY
NIGHT INTO FRIDAY MORNING. THIS IS FOLLOWED BY A 1050 MB HIGH
BUILDING ACROSS NORTH DAKOTA THROUGH THE REMAINDER OF THE DAY ON
FRIDAY. WHEN COMBINED WITH THE SNOW COVER THAT WILL BE ACROSS THE
NORTH...THE COLDEST NIGHT OF THE SEASON THUS FAR IS EXPECTED WITH
LOWS NEAR -15 NORTH...WITH THE SINGLE DIGITS BELOW ZERO ACROSS THE
SOUTH. DID UNDERCUT ALL GUIDANCE BY AT LEAST FIVE DEGREES ACROSS
THE SNOWPACK FOR LOWS FRIDAY NIGHT. WIND CHILLS MAY APPROACH
ADVISORY CRITERIA OF -25 TO -30 EARLY SATURDAY MORNING ACROSS THE
NORTH. HIGHS WARM BACK INTO THE 30S ON SUNDAY IN THE WARM SECTOR
OF A SOUTHERN CANADA CLIPPER. HOWEVER...THIS WARM UP IS BRIEF AS
ANOTHER COOL CANADIAN AIRMASS PROPAGATES SOUTH EARLY NEXT WEEK
UNDER NORTHWEST FLOW ALOFT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 447 PM CST WED NOV 20 2013
A BAND OF MODERATE TO HEAVY SNOW WILL CONTINUE TO MOVE ACROSS
SOUTHWEST AND CENTRAL NORTH DAKOTA LATE THIS AFTERNOON AND EARLY
THIS EVENING. LIFR CONDITIONS ARE EXPECTED AT KMOT...WITH
CONDITIONS FALLING TO IFR AT KDIK...KBIS AND KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 PM CST THIS EVENING FOR
NDZ003>005-009>013-017-018-021.
&&
$$
UPDATE...AYD
SHORT TERM...TWH
LONG TERM...AYD
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS BISMARCK ND
313 PM CST WED NOV 20 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
LATEST RADAR AND WEATHER CAMERAS INDICATE SNOW FROM WEST CENTRAL
INTO NORTH CENTRAL NORTH DAKOTA. SNOW HAS BEEN HEAVY AT TIMES WITH
VISIBILITY DOWN TO A QUARTER. LATEST REPORTS AND ESTIMATES INDICATE
1-2 INCHES HAS FALLEN FROM WILLISTON TO DICKINSON. LIKELY SOME
HIGHER AMOUNTS IN A PERSISTENT BAND ACROSS MAINLY MCKENZIE COUNTY.
THIS BAND HAS BECOMING MORE ENHANCED ACROSS MOUNTRAIL INTO WARD
COUNTY IN THE PAST HOUR.
EXPECT ANOTHER 2 TO 4 HOURS OF LIGHT TO MODERATE SNOW IN THE
ADVISORY AREA...BEFORE SHIFTING FARTHER SOUTH AND EAST. 12 UTC
MODEL GUIDANCE AND THE LATEST MESOSCALE RAP AND HRRR SHOW
PRECIPITATION ENDING QUICKLY AROUND 00 UTC IN WESTERN NORTH DAKOTA
AS BEST FRONTOGENETICAL FORCING SHIFTS INTO CENTRAL NORTH DAKOTA.
THIS SHOULD PUT AN END TO ACCUMULATING SNOW OVER THE ADVISORY AREA
BY MID EVENING. CURRENT HAZARD GOES UNTIL 10 PM AND EVENING SHIFT
CAN CANCEL EARLY IF NEEDED.
BEST SNOW CHANCES ARE OVER CENTRAL NORTH DAKOTA THIS EVENING. AND
ACCUMULATIONS OF AROUND AN INCH ARE POSSIBLE OVER THE SOUTH
CENTRAL AND FAR SOUTHWEST...FROM BOWMAN AND HETTINGER TO BISMARCK
AND JAMESTOWN. LESSER AMOUNTS...UNDER AN INCH ARE EXPECTED FROM
SELFRIDGE TO LAMOURE AND OAKES. MODEL SOUNDINGS INDICATE WARM
TEMPERATURES ALOFT IN THE FAR SOUTH CENTRAL...THUS HAVE INCLUDED A
MENTION OF MIXED PRECIPITATION SOUTH OF BISMARCK TO THE SOUTHERN
JAMES RIVER VALLEY.
PRECIPITATION ENDS QUICKLY IN THE CENTRAL AS THE UPPER TROUGH
TRANSLATES INTO THE AREA LATE TONIGHT. THEN WE ARE LOOKING AT VERY
COLD TEMPERATURES AND WIND CHILLS LATE TONIGHT AND THURSDAY. WIND
CHILLS FROM 10 BELOW SOUTH TO 20 BELOW NORTHWEST CAN BE EXPECTED
EARLY THURSDAY MORNING.
THURSDAY IS EXPECTED TO BE DRY BUT COLD WITH HIGHS OF 10 TO 20 ABOVE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 312 PM CST WED NOV 20 2013
THE HIGHLIGHT OF THE EXTENDED FORECAST IS THE COLDEST AIR OF THE
SEASON THUS FAR FOR FRIDAY NIGHT INTO SATURDAY MORNING.
THE 12 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A WEAK
CLIPPER SYSTEM PROPAGATING NEAR THE INTERNATIONAL BORDER THURSDAY
NIGHT INTO FRIDAY MORNING. THIS IS FOLLOWED BY A 1050 MB HIGH
BUILDING ACROSS NORTH DAKOTA THROUGH THE REMAINDER OF THE DAY ON
FRIDAY. WHEN COMBINED WITH THE SNOW COVER THAT WILL BE ACROSS THE
NORTH...THE COLDEST NIGHT OF THE SEASON THUS FAR IS EXPECTED WITH
LOWS NEAR -15 NORTH...WITH THE SINGLE DIGITS BELOW ZERO ACROSS THE
SOUTH. DID UNDERCUT ALL GUIDANCE BY AT LEAST FIVE DEGREES ACROSS
THE SNOWPACK FOR LOWS FRIDAY NIGHT. WIND CHILLS MAY APPROACH
ADVISORY CRITERIA OF -25 TO -30 EARLY SATURDAY MORNING ACROSS THE
NORTH. HIGHS WARM BACK INTO THE 30S ON SUNDAY IN THE WARM SECTOR
OF A SOUTHERN CANADA CLIPPER. HOWEVER...THIS WARM UP IS BRIEF AS
ANOTHER COOL CANADIAN AIRMASS PROPAGATES SOUTH EARLY NEXT WEEK
UNDER NORTHWEST FLOW ALOFT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 312 PM CST WED NOV 20 2013
SNOW WILL MOVE EASTWARD THROUGH NORTH DAKOTA THROUGHOUT THE DAY
AND TAPPER OFF THROUGH THE OVERNIGHT HOURS. MVFR TO IFR CEILINGS
AND REDUCED VISIBILITIES CAN BE EXPECTED THROUGH MUCH OF THE DAY.
THEN IMPROVING FROM WEST TO EAST TONIGHT. WINDS WILL REMAIN
NORTHERLY NEAR 15 MPH THROUGH THE TAF PERIOD...BECOMING WEST TO
SOUTHWESTERLY FROM 12Z TO 18Z THURSDAY.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 PM CST THIS EVENING FOR
NDZ009>011-017-018-021.
&&
$$
SHORT TERM...TWH
LONG TERM...AYD
AVIATION...TWH
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1205 PM CST WED NOV 20 2013
.UPDATE...
AREA OF PRECIPITATION OVER EASTERN IOWA AND SOUTHWARD WILL
CONTINUE TO SHIFT NORTHEAST INTO THE AREA THIS AFTERNOON...MOVING
ACROSS THIS EVENING. THIS IS BEING DRIVEN BY FOCUSED WARM AIR
ADVECTION...ALONG WITH PASSING 500 MB SHORTWAVE TROUGH. DRY AIR IN
THE LOW LEVELS WILL LIMIT THE PUSH OF LIGHT RAIN INTO WESTERN
PORTIONS OF THE AREA...BEFORE BECOMING MORE WIDESPREAD WEST TO
EAST AROUND 00Z THURSDAY PER HRRR AND 4 KM WRF/NMM MODELS.
FORECAST SOUNDINGS ACROSS THE WESTERN PORTIONS OF THE AREA ARE
TRYING TO SHOW SOME LIGHT SNOW MIXING IN WITH THE LIGHT RAIN EARLY
THIS EVENING...BUT PUSH OF WARM AIR ADVECTION SHOULD KEEP WET BULB
PROFILES WARM ENOUGH FOR LIGHT RAIN. TEMPERATURES MAY BE A BIT TOO
WARM...SO WILL ADJUST AS NEEDED FOR CURRENT TRENDS.
&&
.AVIATION/12Z TAFS/...
LIGHT RAIN SHOULD SPREAD EASTWARD ACROSS TAF SITES...FROM BETWEEN
22Z WEDNESDAY AT MADISON...TO AROUND 00Z THURSDAY AT THE EASTERN
SITES. THE LIGHT RAIN WILL END BETWEEN 05Z AT MADISON...AND 08Z AT
THE EASTERN TAF SITES. MVFR CEILINGS AND VISIBILITIES ARE EXPECTED
ONCE THE RAIN MOVES IN...AND CONTINUING THROUGH THE REST OF
TONIGHT. THE MVFR CEILINGS WILL LINGER ON THURSDAY.
GUSTY SOUTH SOUTHEAST WINDS THIS AFTERNOON WILL GRADUALLY SUBSIDE
BY EVENING ACROSS TAF SITES...WITH SOUTHEAST WINDS CONTINUING TO
WEAKEN TONIGHT. LIGHT AND VARIABLE WINDS ARE THEN EXPECTED LATER
TONIGHT INTO THURSDAY...BEFORE BECOMING LIGHT NORTH TO NORTHEAST
LATE THURSDAY AFTERNOON.
&&
.MARINE...
SMALL CRAFT ADVISORY CONTINUES ACROSS THE NEARSHORE WATERS OF LAKE
MICHIGAN UNTIL 10Z THURSDAY. MARINE OBSERVATIONS ALONG THE SHORE
HAVE SHOWN SOME SOUTH SOUTHEAST GUSTS IN THE 30 TO 35 KNOT
RANGE...BUT SHOULD GRADUALLY DIMINISH THIS AFTERNOON INTO THIS
EVENING.
WINDS WILL BECOME LIGHT LATER TONIGHT INTO THURSDAY...BEFORE
BECOMING NORTH TO NORTHEAST LATER THURSDAY AFTERNOON. HIGH WAVES
OF 5 TO 8 FEET WILL GRADUALLY SUBSIDE WITH THE WEAKENING WINDS BY
LATER TONIGHT.
&&
.PREV DISCUSSION... /ISSUED 400 AM CST WED NOV 20 2013/
TODAY AND TONIGHT...FORECAST CONFIDENCE MEDIUM TO HIGH.
MODELS DIFFER A BIT IN TIMING WITH ISENTROPICALLY-DRIVEN PCPN...SO
USED A BLENDED SOLUTION FOR POPS. INITIAL PCPN BANDS ON AREA RADARS
ONLY PRODUCING ISOLATED TRACE AMOUNTS WITH CLOUD BASES BETWEEN 7K
AND 9K FT...REFLECTING DIFFICULTY OF GETTING MEASURABLE PCPN UNTIL
LOWER LAYERS SATURATE. COULD SEE A FEW SPRINKLES THIS MORNING
WITH THESE INITIAL BANDS...BUT WILL SEE BETTER CHANCES OF LIGHT
RAIN MOVE IN LATE MORNING/EARLY AFTERNOON IN THE WEST AND LATE
AFTERNOON/EVENING IN THE EAST WITH SECOND SURGE OF ISENTROPIC LIFT
AND LOWER CONDENSATION PRESSURE DEFICITS...AS WELL AS ADDITIONAL
FORCING FROM DCVA AHEAD OF SHORT WAVE. AMOUNTS WILL BE LIGHT...BUT
UPPED POPS TO CATEGORICAL WEST AND HIGH LIKELY EAST.
BLENDED SOLUTION TAKES PRECIPITATION OUT OF CWA WITH WAVE BETWEEN
06Z AND 09Z. RIGHT NOW THE FORECAST SOUNDINGS INDICATE PCPN ALL
LIQUID...BUT MAY HAVE TO WATCH FOR SOME SNOW FLAKES MIXING IN THE
NORTH AS PCPN ENDS.
WARM AIR ADVECTION REMAINS STRONGER ALOFT...WITH CLOUDS AND PCPN
FURTHER LIMITING TEMPS...BUT SHOULD STILL SEE HIGHS IN THE LOW 40S.
NOT MUCH OF A DROP OFF TONIGHT WITH LOWS ABOUT 7-8F LOWER THAN
DAYTIME HIGHS AS COOLER AIR STAYS TO THE NW OF SURFACE TROUGH
THAT IS JUST SAGGING INTO NW PORTION OF CWA AT 12Z THURSDAY.
THURSDAY AND FRIDAY - CONFIDENCE...MEDIUM
BRIEF RIDGING ALOFT AFTER THE PASSAGE OF THE WEDNESDAY NIGHT
WAVE. THE NEXT 500 MILLIBAR SHORTWAVE ARRIVES FOR THURSDAY
AFTERNOON BRINGING ANOTHER ROUND OF LIGHT PRECIPITATION. WEAK
700-300 MILLIBAR Q-VECTOR CONVERGENCE. BEST 850-700 MILLIBAR
Q-VECTOR CONVERGENCE TO THE SOUTHEAST. UPPER JET COMES INTO PLAY
THOUGH MODEL DIVERGENT SIGNALS ARE WEAK. LOW LEVEL THERMAL
PROFILES SUPPORT RAIN DURING THURSDAY THEN 925/850 MILLIBAR COLD
AIR PUSH STARTS TO SLIDE INTO THE CWA THURSDAY NIGHT...SO WILL
SHOW A GRADUAL TRANSITION TO A MIX AND EVENTUALLY ALL LIGHT SNOW
IN THE NW CWA. HIGHS WILL OCCUR EARLY FRIDAY AS COLDER AIRMASS
CONTINUES TO PUSH IN WITH 850/925 COLD AIR ADVECTION. MODELS SHOW
PRETTY DECENT DRY PUSH WORKING IN AS THE DAY GOES ON...NAM IS
ESPECIALLY AGGRESSIVE IN SCOURING OUT THE CLOUD COVER.
SATURDAY - CONFIDENCE...MEDIUM
COLD AIRMASS CONTINUES TO POUR INTO THE AREA WITH 850 TEMPS
DROPPING TO -18 TO -20C. UPPER FLOW IS STILL STRONGLY CYCLONIC
THOUGH AIRMASS PROGGD TO BE VERY DRY. WILL LEAVE DRY FCST INTACT.
HIGHS FOR MOST AREAS WILL REMAIN IN THE 20S.
SUNDAY - CONFIDENCE...MEDIUM DECENT 850 WAA PATTERN SETS UP. AT
925...THERMAL TROUGH LINGERS THROUGH THE MORNING WITH SOME
MODIFICATION INTO THE AFTERNOON. GFS SOUNDINGS SHOW POTENTIAL TO
MIX TO 925 WHICH SHOWS RECOVERY TO THE MID 20S.
MONDAY AND TUESDAY - CONFIDENCE...MEDIUM
COLD AIRMASS GETS REINFORCED WITH ANOTHER FRONT MONDAY NIGHT. 850
TEMPS BACK INTO THE TEENS BELOW ZERO CELSIUS. CURRENT ALLBLEND
GIVING HIGHS IN THE LOW/MID 30S THOUGH WITH 925 TEMPS PROGGD
ANYWHERE FROM -7 TO -10C MAY BE ANOTHER TOUGH DAY GETTING OUT OF
THE 20S. BASED ON COLLAB WITH SURROUNDING OFFICES TWEAKED TEMPS
DOWN A SMIDGE FOR STARTERS.
AVIATION/12Z TAFS/...EXPECT VFR CLOUD DECK TO LOWER WITH
CONTINUING WARM AIR/MOISTURE ADVECTION. COULD SEE A FEW SPRINKLES
BUT BETTER CHANCES FOR STEADY LIGHT RAIN WITH MVFR VSBYS COME
INTO KMSN LATE MORNING/EARLY AFTERNOON AND INTO EASTERN TAF SITE
BY EARLY EVENING. SOME CONCERN WITH NAM SHOWING LOWER CIGS
SETTLING IN AS PCPN MOVES OUT.
MARINE...NO CHANGE TO GOING SMALL CRAFT ADVISORY HEADLINE.
FORECAST WIND GUSTS WILL APPROACH GALE FORCE FOR A TIME
TODAY...WITH WINDS SLOWLY EASING STARTING LATE THIS AFTERNOON
INTO THE EVENING. END TIME OF ADVISORY WILL ALLOW TIME FOR WAVES
TO SUBSIDE...THOUGH THEY WILL STAY IN THE 3 TO 4 FOOT RANGE INTO
THURSDAY MORNING IN THE NORTHERN ZONES.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM CST THURSDAY FOR LMZ643>646.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...REM
THURSDAY THROUGH TUESDAY...COLLAR