Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 11/22/15
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
1113 AM MST FRI NOV 20 2015
.UPDATE...
ISSUED AT 1113 AM MST FRI NOV 20 2015
SHORT TERM GUIDANCE AND HRRR SHOWING SOME GUSTY WINDS QUICKLY
DEVELOPING AROUND NOONTIME...SUPPORTED BY STRONG JET ALOFT...AS
THE SHORT WAVE MOVES DOWNSTREAM. BOOSTED GRIDDED WINDS TO REFLECT
THIS IDEA. WIND GUSTS TO 40 MPH WILL BE COMMON ACROSS THE NRN
VALLEYS AND ALONG THE I70 CORRIDO EAST OF GRAND JUNCTION. THIS IS
BELOW WIND ADVISORY CRITERIA AND NO PLANS TO ISSUE ONE.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 229 AM MST FRI NOV 20 2015
A FEW INCHES OF NEW SNOW FELL OVER THE NORTHERN MTNS AND AREAS OF
THE CENTRAL MTNS OVERNIGHT AS ONE JET STREAK MOVED OVERHEAD. THE
SECOND STREAK THAT IS PROGGED TO MOVE OVER THE SAME AREA FROM
ABOUT DAYBREAK THROUGH THE EVENING HOURS TODAY IS WHEN THE MOST
SNOW WILL FALL. IMPORTANT TO MENTION THAT MODELS HAVE PULLED BACK
ON SNOW AMOUNTS THROUGH THE DAY WITH THE GFS PULLING BACK THE
MOST. EVEN SO...HIGHLIGHTS IN PLACE LOOK GOOD BUT WILL NEED TO BE
MONITORED THROUGH THE DAY AS MODELS STILL DON`T AGREE THAT WELL.
AREAS AWAY FROM THE MTNS WILL SEE GENERALLY PARTLY CLOUDY SKIES
WITH NEAR NORMAL TEMPS IF NOT A LITTLE ABOVE. PRECIP WILL END BY
EARLY SATURDAY MORNING GIVING WAY TO MOSTLY SUNNY SKIES AS HIGH
PRESSURE BUILDS IN.
AS FAR AS TEMPS ARE CONCERNED...THICKNESS VALUES CONTINUE TO SHOW
TEMPS DROPPING AFTER THE CURRENT SYSTEM MOVES OFF TO THE EAST. NAM
GUIDANCE REALLY DROPS TEMPS...SINGLE DIGITS TO TEENS BY SATURDAY
MORNING...WHILE GFS NOT AS DRASTIC BUT STILL INDICATING TEMPS
MUCH COOLER THAN SEEN RECENTLY. EITHER WAY...A RATHER BRISK
SATURDAY IN STORE.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 229 AM MST FRI NOV 20 2015
MID-RANGE MODELS AGREE THAT MONDAY AND TUESDAY WILL BRING PLEASANT
WEATHER AS HIGH PRESSURE REMAINS IN CONTROL WITH TEMPS WARMING UP
EACH DAY. BY WEDNESDAY MORNING...A CLOSED LOW WILL BE APPROACHING
THE AREA FROM THE NW CAUSING INCREASED CLOUD COVERAGE AND PRECIP
CHANCES FROM ABOUT NOON ONWARDS. THE LOCATION OF THE LOW PRESSURE
WILL SET UP TO THE WEST OF THE GREAT SALT LAKE IN UT AND STAY
THERE SPINNING FOR THE REST OF THE WEEK. THIS OCCURS AS UPPER
LEVEL SUPPORT GETS CUTOFF AND NO KICKER SHOWS ITSELF UNTIL THE
WEEKEND TO GET THE SYSTEM MOVING AGAIN. THE EC ALSO BITING OFF ON
THIS SOLN THOUGH DIFFERENCES SHOW UP FOR THE WEEKEND. PRECIP
CERTAINLY POSSIBLE FOR THE CWA BUT THE FINER DETAILS...HOW
MUCH...WHERE...HOW LONG...JUST NOT THERE YET. DOES LOOK MORE
LIKELY THAT THANKSGIVING WILL BE UNSETTLED THOUGH WITH COOLER THAN
AVERAGE TEMPERATURES. AS THIS SYSTEM IS A LONG WAYS OUT...PLENTY
OF CHANGES POSSIBLE OVER THE COMING DAYS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1113 AM MST FRI NOV 20 2015
THROUGH 02Z THIS EVENING...IFR/MVFR CIGS OR BELOW ILS BREAKPOINTS
WILL BE COMMON TODAY OVER THE NORTHERN AND CENTRAL COLORADO
MOUNTAINS. PERIODS OF SNOW IS EXPECTED IN THE HIGH COUNTRY...
ALTHOUGH LIGHT SNOW/RAIN MAY OCCUR AT KEGE OR KASE. MECHANICAL
TURBULENCE OVER THE MOUNTAINS IS EXPECTED.
IMPROVING CONDITIONS ARE EXPECTED AFTER 02Z WITH A CLEARING TREND
UNDERWAY. ALL MOUNTAIN SITES WILL HAVE VFR CONDITIONS AFTER 06Z.
VFR WILL BE MAINAINED FOR THE LOWER ELEVATIONS AND DESERT VALLEYS.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL 6 PM MST THIS EVENING FOR COZ004-
010-013.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ004.
UT...NONE.
&&
$$
UPDATE...PF
SHORT TERM...TGR
LONG TERM...TGR
AVIATION...PF
AREA FORECAST DISCUSSION
NWS ALBANY NY
937 PM EST SAT NOV 21 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST THROUGH THE EASTERN
GREAT LAKES TONIGHT...AND DRAG A COLD FRONT ACROSS THE REGION WITH
WIDELY SCATTERED RAIN AND SNOW SHOWERS. ANY SNOWFALL ACCUMULATION
WILL BE CONFINED TO THE SOUTHERN ADIRONDACKS. BREEZY WEST TO
NORTHWEST WINDS WILL BRING COOLER AIR BACK INTO THE AREA ON
SUNDAY...ALONG WITH SOME LAKE EFFECT SNOW SHOWERS OVER THE
ADIRONDACKS. MAINLY DRY AND COLD WEATHER IS EXPECTED ON MONDAY
ALTHOUGH THERE COULD BE ADDITIONAL SNOW SHOWERS ACROSS THE
ADIRONDACKS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 935 PM EST...HAD TO ADJUST FORECAST SLIGHTLY TO MATCH
CURRENT TREND IN TEMPERATURES...WITH AREAS SEEING BREAKS IN SKY
COVER DROPPING RATHER QUICKLY INTO THE LOW AND MID 30S...WITH EVEN
SOME UPPER 20S ACROSS HIGHER TERRAIN LOCATIONS. WHERE CLOUD COVER
HAS HELD ON...TEMPERATURES HAVE HELD STEADY...AND IN SOME
SPOTS...EVEN RISEN A DEGREE OR TWO DUE TO WEAK WARM AIR ADVECTION
AHEAD AN APPROACHING COLD FRONT/QUASI-OCCLUDED FRONT ASSOCIATED
WITH AN AREA OF LOW PRESSURE TRACKING NORTHEAST ACROSS THE GREAT
LAKES REGION.
IT WILL CONTINUE TO REMAIN DRY ACROSS THE REGION UNTIL AFTER
MIDNIGHT WHEN WIDELY SCATTERED RAIN/SNOW SHOWER ACTIVITY WILL BE
POSSIBLE ACROSS THE REGION. LATEST TRENDS IN MESOSCALE GUIDANCE
CONTINUE TO SHOW LESS AREAL COVERAGE OF ANY SHOWER ACTIVITY THAT
DOES DEVELOP...WITH THE BEST CHANCE FOR RAIN/SNOW SHOWERS FROM THE
CAPITAL REGION AND POINTS NORTH AND WEST.
SHOWERS WILL PRIMARILY BE SNOW ACROSS THE SOUTHERN
ADIRONDACKS...WHERE UP TO A HALF AN INCH OF ACCUMULATION WILL BE
POSSIBLE BY DAYBREAK. ELSEWHERE...PRIMARILY RAIN SHOWERS WILL BE
LIKELY...ALTHOUGH A FEW WET SNOWFLAKES MAY MIX IN OCCASIONALLY
IN THE LAKE GEORGE/SARATOGA REGION AND ACROSS THE UPPER
TACONICS/SOUTHERN VERMONT. IN THESE LOCATIONS NO SNOW ACCUMULATION
IS EXPECTED WITH PERHAPS A DUSTING AT BEST ACROSS THE HIGHEST
PEAKS OF THE SOUTHERN GREENS IN VERMONT.
OVERNIGHT LOWS WILL RANGE FROM THE UPPER 20S/LOW 30S ACROSS THE
HIGHER TERRAIN...WESTERN MOHAWK VALLEY AND LAKE GEORGE REGION...TO
MID AND UPPER 30S IN THE CAPITAL REGION/MID HUDSON VALLEY. A SOUTH
BREEZE WILL AVERAGE 5-15 MPH TONIGHT AND BECOME WESTERLY BY
DAYBREAK AS THE FRONT MOVES ON BY. IT MAY BE GUSTY AT
TIMES...20-30 MPH...OVERNIGHT MAINLY ACROSS PORTIONS OF THE MOHAWK
VALLEY AND SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
AS THE FRONT MOVES ON BY...CHILLIER AIR WILL FILTER INTO THE REGION.
HOWEVER...WITH A WSW FLOW AND A GOOD DEAL OF SUNSHINE...TEMPERATURES
WILL ACTUALLY WARM TO NEAR 50 IN THE VALLEYS...WHILE HOLDING CLOSER
TO 40 ACROSS THE HIGHER TERRAIN. KEEP IN MIND THESE VALUES MIGHT
HAPPEN BY MIDDAY...WITH TEMPERATURES FALLING A BIT DURING THE
AFTERNOON.
IT WILL BE BREEZY WITH A WEST WIND 10-15 MPH...GUSTING TO 25 MPH
ESPECIALLY OVER THE HIGHER TERRAIN/MOHAWK VALLEY AND THE CAPITAL REGION.
WHILE MOST OF THE AREA WILL BE DRY WITH PARTIAL SUNSHINE...LAKE ENHANCED
CLOUDS AND PERHAPS SOME SNOW SHOWERS WILL PERSIST OVER
THE ADIRONDACKS. EVEN IF SURFACE TEMPERATURES ARE ABOVE FREEZING
ON SUNDAY...THE AIR WILL BE QUITE CHILLY ALOFT AND CERTAINLY VERTICAL
INSTABILITY AND UPSLOPE COULD GENERATE THESE SNOW SHOWERS EVEN IN
THE ABSENCE OF ANY PURE LAKE EFFECT.
HOWEVER...AFTER EXAMINING THE EXPERIMENTAL KVIE CSTAR PROGRAM...
IT NOW APPEARS THE INLAND LAKE EXTENT OFF OF ONTARIO WILL ONLY
BE ABOUT 50 MILES...LIMITED DUE TO SOME SHEAR IN THE COLUMN AND
DRY AIR IN THE MID LEVELS. THEREFORE PURE LAKE EFFECT SNOW
PLUMES MIGHT ONLY GRAZE HERKIMER AND LIKELY NOT EVEN REACH
HAMILTON COUNTIES. THEREFORE NO HEADLINES WERE ISSUED.
IF CONDITIONS LOOK DIFFERENT LATER ON...HEADLINES WILL BE RECONSIDERED.
ANY ADDITIONAL SNOW ACCUMULATIONS ON SUNDAY OVER THE ADIRONDACKS SHOULD
LIGHT...AN INCH OR LESS.
SUNDAY NIGHT THROUGH MONDAY NIGHT...LARGE HIGH PRESSURE WILL
BUILD TO OUR SOUTH. ADDITIONAL SHORT WAVE ENERGY ALONG
WITH ANOTHER MID LEVEL TROUGH ROLLING TO OUR NORTH...
COULD TRIGGER A FEW MORE BOUTS OF SNOW SHOWERS WITH ADDITIONAL
MAINLY MINOR ACCUMULATIONS OVER OUR ADIRONDACKS AND
PERHAPS CENTRAL MOHAWK VALLEY. THIS AGAIN ASSUMES THE MAIN
PLUMES OFF ONTARIO STAY MAINLY TO OUR WEST. IT WILL BE A CLOSE
CALL BUT RIGHT NOW THEY APPEAR TO JUST MISS MOST OF OUR AREA.
THE POTENTIAL IS THERE FOR 1-4 INCHES OF SNOWFALL WHEN IT IS ALL SAID AND
DONE...SPREAD OUT OVER SEVERAL PERIODS SO AGAIN NO LAKE EFFECT SNOW
ADVISORIES WERE ISSUED WITH THIS PACKAGE. KEEP IN MIND IF ANY
PLUME FROM LAKE ONTARIO WAS ABLE TO PENETRATE INTO HERKIMER OR
HAMILTON COUNTIES...AMOUNTS COULD BE LOCALLY A LITTLE HIGHER.
THE REMAINDER OF THE REGION SHOULD REMAIN MOSTLY DRY ALTHOUGH A SPRINKLE
OR FLURRY IS POSSIBLE ALONG WITH OCCASIONAL CLOUDINESS.
OTHERWISE IT LOOKS CHILLY BUT NOTHING OUT OF THE ORDINARY
FOR LATE NOVEMBER.
LOW TEMPERATURES MONDAY MORNING WILL BE MAINLY IN THE 20S...WITH SOME TEENS
IN THE COLDEST AREAS. HIGHS MONDAY WILL BE ONLY IN THE UPPER 20S TO MID 30S
HIGHER TERRAIN...CLOSE TO 40 IN THE VALLEYS.
BY TUESDAY...AS HIGH PRESSURE SLOWLY BEGINS TO BUILD ALOFT...THERE WILL BE
SLOW MODERATION IN THE AIRMASS. ANY LINGERING SNOW SHOWERS WILL
CEASE ACROSS THE ADIRONDACKS. OTHERWISE IT WILL BE MOSTLY SUNNY.
LOWS TUESDAY MORNING WILL RANGE FROM THE MID TEENS TO MID 20S.
HIGHS TUESDAY WILL RANGE FROM THE 30S OVER THE HIGHER TERRAIN...
LOWER TO MID 40S IN THE VALLEYS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY MAINLY DRY WEATHER
WITH THE NEXT CHANCE FOR PRECIPITATION ACROSS THE REGION FRIDAY INTO
SATURDAY AS A FRONTAL BOUNDARY MOVES ACROSS THE REGION.
AT THE START OF THE LONG TERM PERIOD...THE LONG RANGE GUIDANCE
CONTINUES TO BE IN VERY GOOD AGREEMENT WITH THE EVOLUTION OF THE
LONG TERM PATTERN. MUCH OF THE LONG TERM PERIOD WILL BE DOMINATED BY
HIGH PRESSURE AT THE SURFACE AND UPPER-LEVEL RIDGING ALOFT. THIS
WILL RESULT IN AN EXTENDED PERIOD OF DRY WEATHER TUESDAY NIGHT
THROUGH THURSDAY NIGHT...INCLUDING THANKSGIVING...WITH PARTLY CLOUDY
SKIES.
A FRONTAL BOUNDARY WILL MOVE ACROSS THE REGION FRIDAY INTO THE
SATURDAY TIME PERIOD. THERE IS SOME DIFFERENCE IN THE LONG RANGE
GUIDANCE REGARDING THE TIMING OF THIS FRONTAL BOUNDARY...BUT HAVE
INDICATED CHANCE POPS DURING THIS TIMEFRAME FOR RAIN SHOWERS DURING
THE DAYTIME HOURS...AND A MIX OF RAIN/SNOW SHOWERS DURING THE
NIGHTTIME HOURS WITH THE BEST CHANCE FOR SNOW ACROSS THE HIGHER
TERRAIN.
TEMPERATURES DURING THE LONG TERM PERIOD WILL BE SLIGHTLY ABOVE
NORMAL FOR LATE NOVEMBER. HIGHS ON WEDNESDAY WILL RANGE FROM THE
UPPER 30S/LOW 40S ACROSS THE HIGHER TERRAIN TO THE MID AND UPPER 40S
IN VALLEY AREAS. HIGHS ON THURSDAY AND FRIDAY WILL RANGE FROM THE
UPPER 40S TO MID 50S. HIGHS ON SATURDAY WILL RANGE FROM NEAR 40 TO
NEAR 50. LOWS TUESDAY NIGHT WILL RANGE FROM THE MID TO UPPER
20S...UPPER 20S TO LOWER 30S WEDNESDAY NIGHT...AND MID 30S TO NEAR
40 THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS EARLY THIS EVENING WILL GIVE WAY TO MVFR CEILINGS
OVERNIGHT AS A COLD FRONT AND ASSOCIATED SCATTERED RAIN/SNOW
SHOWERS MOVES ACROSS THE REGION.
TONIGHT...SCATTERED RAIN SHOWERS...POSSIBLY MIXING WITH SNOW
FLAKES...WILL BE POSSIBLE AT THE TAF SITES AFTER MIDNIGHT WITH THE
BEST CHANCE FOR SHOWERS AT KGFL WHERE -RASN WAS INDICATED IN THE
TAF. NO SNOW ACCUMULATION IS EXPECTED AT ANY OF THE TAF SITES. AT
KALB...KPOU AND KPSF HAVE ONLY GONE WITH VCSH AS SHOWER ACTIVITY
WILL BE HIGHLY SCATTERED.
SUNDAY...A FRONT WILL PASS THROUGH SHIFTING THE WIND TO THE WEST
AROUND 10KTS WITH GUSTS TO 20KTS AT KPSF AND KALB. CONDITIONS WILL
RETURN TO VFR WITH GOOD VISIBILITY AT THE TAF SITES BY 15Z SUNDAY.
OUTLOOK...
SUNDAY NIGHT-THANKSGIVING DAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
A FRONTAL SYSTEM WILL BRING SOME SHOWERS OF RAIN AND SNOW TONIGHT...
HEAVIEST ACROSS THE ADIRONDACKS WHERE A COUPLE INCHES OF SNOW
COULD ACCUMULATE. OTHERWISE...RAIN SHOWER AMOUNTS WILL BE
VERY LIGHT...WELL UNDER A QUARTER INCH MOST PLACES.
ASIDE FROM ON GOING SNOW SHOWERS ACROSS THE ADIRONDACKS...
THE REMAINDER OF THE REGION LOOKS MAINLY DRY SUNDAY THROUGH
THANKSGIVING DAY. EACH NIGHT WILL SEE A NEAR RECOVERY
OF RR VALUES...DROPPING TO SEASONABLE LEVELS IN THE 40S AND
50S EACH AFTERNOON. AMOUNTS WILL BE HIGHER ACROSS THE ADIRONDACKS
WHERE THERE WILL BE POSSIBLE PRECIPITATION...GENERALLY
IN THE 50S AND EVEN 60S.
IT WILL BE SOMEWHAT BREEZY ON SUNDAY...WITH A WESTERLY
WIND 10-15 MPH WITH GUSTS TO 25 MPH ACROSS THE HIGHER
TERRAIN/MOHAWK VALLEY AND CAPITAL REGION.
THE WIND WILL GENERALLY BE LIGHTER THROUGH THE REMAINDER OF THE WEEK.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION AFTER TONIGHT DOES NOT
APPEAR TO BE UNTIL LATE FRIDAY OR SATURDAY.
&&
.HYDROLOGY...
NO HYDROLOGY ISSUES ARE EXPECTED THROUGH THE NEXT WEEK. OTHER THAN
THE POTENTIAL FOR SCATTERED SHOWERS TONIGHT AND LAKE
ENHANCED SNOW SHOWERS IN HAMILTON AND HERKIMER COUNTIES SUNDAY...THE
PERIOD WILL BE MAINLY DRY THROUGH FRIDAY.
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...HWJIV/IRL
NEAR TERM...HWJIV/IRL
SHORT TERM...HWJIV
LONG TERM...IRL
AVIATION...IRL
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
652 PM EST SAT NOV 21 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST THROUGH THE EASTERN
GREAT LAKES TONIGHT...AND DRAG A COLD FRONT ACROSS THE REGION WITH
SCATTERED RAIN AND SNOW SHOWERS. ANY ACCUMULATION WILL BE CONFINED
TO THE SOUTHERN ADIRONDACKS. BREEZY NORTHWEST WINDS WILL BRING
COOLER AIR BACK INTO THE AREA ON SUNDAY...ALONG WITH SOME LAKE
EFFECT SNOW SHOWERS OVER THE ADIRONDACKS. MAINLY DRY AND COLD
WEATHER IS EXPECTED ON MONDAY ALTHOUGH THERE COULD BE ADDITIONAL
SNOW SHOWERS ACROSS THE ADIRONDACKS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 650 PM EST...CURRENT FORECAST REMAINS ON TRACK WITH ONLY
MINOR ADJUSTMENTS MADE TO ACCOUNT FOR THE LATEST OBSERVATIONS. DID
BUMP UP POPS SLIGHTLY FROM THE CAPITAL REGION AND POINTS NORTH AND
WEST LATE TONIGHT AS MESOSCALE GUIDANCE IS HINTING AT SLIGHTLY
GREATER SHOWER COVERAGE AS THE COLD FRONT MOVES THROUGH.
IT WILL CONTINUE TO REMAIN DRY ACROSS THE REGION UNTIL AFTER
MIDNIGHT WHEN SCATTERED RAIN/SNOW SHOWER ACTIVITY AHEAD OF AN
APPROACHING COLD FRONT IMPACTS THE REGION. TEMPERATURES THIS
EVENING ACROSS THE REGION RANGE FROM THE UPPER 30S TO MID
40S...WITH GENERALLY BROKEN SKIES. THE COLDEST TEMPERATURES ACROSS
THE REGION HAVE OCCURRED THANKS IN PART TO BREAKS IN THE CLOUD
COVER. CLOUD COVER WILL CONTINUE TO INCREASE THROUGH THE
NIGHT...WITH MOST AREAS LIKELY SEEING MIN TEMPS OCCUR AROUND OR
SHORTLY AFTER MIDNIGHT...BEFORE HOLDING STEADY OR EVEN RISING A
DEGREE OR TWO IN SPOTS TOWARDS DAYBREAK.
INITIALLY ANY PRECIPITATION WILL START AS A RAIN SNOW MIX OVER
THE ADIRONDACKS BUT SHOULD CHANGE TO ALL SNOW OVERNIGHT. ACCUMULATIONS
LOOK MINOR AS SURFACE TEMPERATURES WILL ONLY BE MARGINALLY COLD
ENOUGH FOR ACCUMULATIONS...GENERALLY AN INCH OR LESS.
FURTHER SOUTH AND EAST SHOWERS WILL BE MOSTLY SCATTERED. SNOW
FLAKES COULD MIX IN ANYWHERE BUT WILL LIKELY NOT PRODUCE ANY
ACCUMULATION AS THE QPF LOOKS VERY LIGHT WITH SOME AREAS NOT
GETTING ANY MEASURABLE AT ALL...ESPECIALLY SOUTH OF ALBANY.
OVERNIGHT LOWS WILL RANGE FROM THE UPPER 20S TO MID 30S. A SOUTH
BREEZE WILL AVERAGE 5-15 MPH TONIGHT BECOME WESTERLY BY DAYBREAK
AS THE FRONT MOVES ON BY.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
AS THE FRONT MOVES ON BY...CHILLIER AIR WILL FILTER INTO THE REGION.
HOWEVER...WITH A WSW FLOW AND A GOOD DEAL OF SUNSHINE...TEMPERATURES
WILL ACTUALLY WARM TO NEAR 50 IN THE VALLEYS...WHILE HOLDING CLOSER
TO 40 ACROSS THE HIGHER TERRAIN. KEEP IN MIND THESE VALUES MIGHT
HAPPEN BY MIDDAY...WITH TEMPERATURES FALLING A BIT DURING THE
AFTERNOON.
IT WILL BE BREEZY WITH A WEST WIND 10-15 MPH...GUSTING TO 25 MPH
ESPECIALLY OVER THE HIGHER TERRAIN/MOHAWK VALLEY AND THE CAPITAL REGION.
WHILE MOST OF THE AREA WILL BE DRY WITH PARTIAL SUNSHINE...LAKE ENHANCED
CLOUDS AND PERHAPS SOME SNOW SHOWERS WILL PERSIST OVER
THE ADIRONDACKS. EVEN IF SURFACE TEMPERATURES ARE ABOVE FREEZING
ON SUNDAY...THE AIR WILL BE QUITE CHILLY ALOFT AND CERTAINLY VERTICAL
INSTABILITY AND UPSLOPE COULD GENERATE THESE SNOW SHOWERS EVEN IN
THE ABSENCE OF ANY PURE LAKE EFFECT.
HOWEVER...AFTER EXAMINING THE EXPERIMENTAL KVIE CSTAR PROGRAM...
IT NOW APPEARS THE INLAND LAKE EXTENT OFF OF ONTARIO WILL ONLY
BE ABOUT 50 MILES...LIMITED DUE TO SOME SHEAR IN THE COLUMN AND
DRY AIR IN THE MID LEVELS. THEREFORE PURE LAKE EFFECT SNOW
PLUMES MIGHT ONLY GRAZE HERKIMER AND LIKELY NOT EVEN REACH
HAMILTON COUNTIES. THEREFORE NO HEADLINES WERE ISSUED.
IF CONDITIONS LOOK DIFFERENT LATER ON...HEADLINES WILL BE RECONSIDERED.
ANY ADDITIONAL SNOW ACCUMULATIONS ON SUNDAY OVER THE ADIRONDACKS SHOULD
LIGHT...AN INCH OR LESS.
SUNDAY NIGHT THROUGH MONDAY NIGHT...LARGE HIGH PRESSURE WILL
BUILD TO OUR SOUTH. ADDITIONAL SHORT WAVE ENERGY ALONG
WITH ANOTHER MID LEVEL TROUGH ROLLING TO OUR NORTH...
COULD TRIGGER A FEW MORE BOUTS OF SNOW SHOWERS WITH ADDITIONAL
MAINLY MINOR ACCUMULATIONS OVER OUR ADIRONDACKS AND
PERHAPS CENTRAL MOHAWK VALLEY. THIS AGAIN ASSUMES THE MAIN
PLUMES OFF ONTARIO STAY MAINLY TO OUR WEST. IT WILL BE A CLOSE
CALL BUT RIGHT NOW THEY APPEAR TO JUST MISS MOST OF OUR AREA.
THE POTENTIAL IS THERE FOR 1-4 INCHES OF SNOWFALL WHEN IT IS ALL SAID AND
DONE...SPREAD OUT OVER SEVERAL PERIODS SO AGAIN NO LAKE EFFECT SNOW
ADVISORIES WERE ISSUED WITH THIS PACKAGE. KEEP IN MIND IF ANY
PLUME FROM LAKE ONTARIO WAS ABLE TO PENETRATE INTO HERKIMER OR
HAMILTON COUNTIES...AMOUNTS COULD BE LOCALLY A LITTLE HIGHER.
THE REMAINDER OF THE REGION SHOULD REMAIN MOSTLY DRY ALTHOUGH A SPRINKLE
OR FLURRY IS POSSIBLE ALONG WITH OCCASIONAL CLOUDINESS.
OTHERWISE IT LOOKS CHILLY BUT NOTHING OUT OF THE ORDINARY
FOR LATE NOVEMBER.
LOW TEMPERATURES MONDAY MORNING WILL BE MAINLY IN THE 20S...WITH SOME TEENS
IN THE COLDEST AREAS. HIGHS MONDAY WILL BE ONLY IN THE UPPER 20S TO MID 30S
HIGHER TERRAIN...CLOSE TO 40 IN THE VALLEYS.
BY TUESDAY...AS HIGH PRESSURE SLOWLY BEGINS TO BUILD ALOFT...THERE WILL BE
SLOW MODERATION IN THE AIRMASS. ANY LINGERING SNOW SHOWERS WILL
CEASE ACROSS THE ADIRONDACKS. OTHERWISE IT WILL BE MOSTLY SUNNY.
LOWS TUESDAY MORNING WILL RANGE FROM THE MID TEENS TO MID 20S.
HIGHS TUESDAY WILL RANGE FROM THE 30S OVER THE HIGHER TERRAIN...
LOWER TO MID 40S IN THE VALLEYS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY MAINLY DRY WEATHER
WITH THE NEXT CHANCE FOR PRECIPITATION ACROSS THE REGION FRIDAY INTO
SATURDAY AS A FRONTAL BOUNDARY MOVES ACROSS THE REGION.
AT THE START OF THE LONG TERM PERIOD...THE LONG RANGE GUIDANCE
CONTINUES TO BE IN VERY GOOD AGREEMENT WITH THE EVOLUTION OF THE
LONG TERM PATTERN. MUCH OF THE LONG TERM PERIOD WILL BE DOMINATED BY
HIGH PRESSURE AT THE SURFACE AND UPPER-LEVEL RIDGING ALOFT. THIS
WILL RESULT IN AN EXTENDED PERIOD OF DRY WEATHER TUESDAY NIGHT
THROUGH THURSDAY NIGHT...INCLUDING THANKSGIVING...WITH PARTLY CLOUDY
SKIES.
A FRONTAL BOUNDARY WILL MOVE ACROSS THE REGION FRIDAY INTO THE
SATURDAY TIME PERIOD. THERE IS SOME DIFFERENCE IN THE LONG RANGE
GUIDANCE REGARDING THE TIMING OF THIS FRONTAL BOUNDARY...BUT HAVE
INDICATED CHANCE POPS DURING THIS TIMEFRAME FOR RAIN SHOWERS DURING
THE DAYTIME HOURS...AND A MIX OF RAIN/SNOW SHOWERS DURING THE
NIGHTTIME HOURS WITH THE BEST CHANCE FOR SNOW ACROSS THE HIGHER
TERRAIN.
TEMPERATURES DURING THE LONG TERM PERIOD WILL BE SLIGHTLY ABOVE
NORMAL FOR LATE NOVEMBER. HIGHS ON WEDNESDAY WILL RANGE FROM THE
UPPER 30S/LOW 40S ACROSS THE HIGHER TERRAIN TO THE MID AND UPPER 40S
IN VALLEY AREAS. HIGHS ON THURSDAY AND FRIDAY WILL RANGE FROM THE
UPPER 40S TO MID 50S. HIGHS ON SATURDAY WILL RANGE FROM NEAR 40 TO
NEAR 50. LOWS TUESDAY NIGHT WILL RANGE FROM THE MID TO UPPER
20S...UPPER 20S TO LOWER 30S WEDNESDAY NIGHT...AND MID 30S TO NEAR
40 THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS EARLY THIS EVENING WILL GIVE WAY TO MVFR CEILINGS
OVERNIGHT AS A COLD FRONT AND ASSOCIATED SCATTERED RAIN/SNOW
SHOWERS MOVES ACROSS THE REGION.
TONIGHT...SCATTERED RAIN SHOWERS...POSSIBLY MIXING WITH SNOW
FLAKES...WILL BE POSSIBLE AT THE TAF SITES AFTER MIDNIGHT WITH THE
BEST CHANCE FOR SHOWERS AT KGFL WHERE -RASN WAS INDICATED IN THE
TAF. NO SNOW ACCUMULATION IS EXPECTED AT ANY OF THE TAF SITES. AT
KALB...KPOU AND KPSF HAVE ONLY GONE WITH VCSH AS SHOWER ACTIVITY
WILL BE HIGHLY SCATTERED.
SUNDAY...A FRONT WILL PASS THROUGH SHIFTING THE WIND TO THE WEST
AROUND 10KTS WITH GUSTS TO 20KTS AT KPSF AND KALB. CONDITIONS WILL
RETURN TO VFR WITH GOOD VISIBILITY AT THE TAF SITES BY 15Z SUNDAY.
OUTLOOK...
SUNDAY NIGHT-THANKSGIVING DAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
A FRONTAL SYSTEM WILL BRING SOME SHOWERS OF RAIN AND SNOW TONIGHT...
HEAVIEST ACROSS THE ADIRONDACKS WHERE A COUPLE INCHES OF SNOW
COULD ACCUMULATE. OTHERWISE...RAIN SHOWER AMOUNTS WILL BE
VERY LIGHT...WELL UNDER A QUARTER INCH MOST PLACES.
ASIDE FROM ON GOING SNOW SHOWERS ACROSS THE ADIRONDACKS...
THE REMAINDER OF THE REGION LOOKS MAINLY DRY SUNDAY THROUGH
THANKSGIVING DAY. EACH NIGHT WILL SEE A NEAR RECOVERY
OF RR VALUES...DROPPING TO SEASONABLE LEVELS IN THE 40S AND
50S EACH AFTERNOON. AMOUNTS WILL BE HIGHER ACROSS THE ADIRONDACKS
WHERE THERE WILL BE POSSIBLE PRECIPITATION...GENERALLY
IN THE 50S AND EVEN 60S.
IT WILL BE SOMEWHAT BREEZY ON SUNDAY...WITH A WESTERLY
WIND 10-15 MPH WITH GUSTS TO 25 MPH ACROSS THE HIGHER
TERRAIN/MOHAWK VALLEY AND CAPITAL REGION.
THE WIND WILL GENERALLY BE LIGHTER THROUGH THE REMAINDER OF THE WEEK.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION AFTER TONIGHT DOES NOT
APPEAR TO BE UNTIL LATE FRIDAY OR SATURDAY.
&&
.HYDROLOGY...
NO HYDROLOGY ISSUES ARE EXPECTED THROUGH THE NEXT WEEK. OTHER THAN
THE POTENTIAL FOR SCATTERED SHOWERS TONIGHT AND LAKE
ENHANCED SNOW SHOWERS IN HAMILTON AND HERKIMER COUNTIES SUNDAY...THE
PERIOD WILL BE MAINLY DRY THROUGH FRIDAY.
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...HWJIV/IRL
NEAR TERM...HWJIV/IRL
SHORT TERM...HWJIV
LONG TERM...IRL
AVIATION...IRL
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS MIAMI FL
715 PM EST SAT NOV 21 2015
.UPDATE...
A BRIEF RESPITE IN THE RAIN OCCURRING ACROSS PORTIONS OF SOUTH FL
THIS MID EVENING....WITH RAIN MOST WIDESPREAD ACROSS THE LAKE
OKEECHOBEE REGION. HOWEVER, RECENT SHOWER DEVELOPMENT JUST
OCCURRED OVER THE SOUTHERN EVERGLADES...AND THIS IS LIKELY A SIGN
OF CONTINUED DEVELOPMENT WITH WAVES OF SHOWERS AND A FEW
THUNDERSTORMS IMPACTING SOUTH FL THROUGHOUT THE NIGHT. HRRR AND
WRF RUNS SHOWING ACTIVE WEATHER OVERNIGHT. AS SUCH...WILL
MAINTAIN THE HIGH POPS GIVEN THE LIKELIHOOD OF RE- DEVELOPMENT.
/GREGORIA
&&
.PREV DISCUSSION... /ISSUED 632 PM EST SAT NOV 21 2015/
AVIATION...
NUMEROUS SHOWERS WILL CONTINUE OVERNIGHT WITH A FEW STORMS.
PREVAILING CONDITIONS SHOULD BE VFR WITH MVFR CIGS AND IFR VSBYS
IN HEAVY RAIN. SHOWERS EXPECTED AGAIN TOMORROW WITH A COLD FRONT
MOVING THROUGH TOMORROW EVENING.
PREV DISCUSSION... /ISSUED 333 PM EST SAT NOV 21 2015/
.WIDESPREAD SHOWERS/FEW TSTORMS TONIGHT-SUNDAY, THEN TURNING
COOLER AND DRIER BEHIND A COLD FRONT SUNDAY NIGHT...
.LOCALLY HEAVY RAINFALL, ISOLATED STREET FLOODING POSSIBLE...
DISCUSSION...
A NEARLY STATIONARY FRONTAL BOUNDARY STRETCHES OVER CENTRAL
FLORIDA JUST NORTH OF LAKE OKEECHOBEE. WATER VAPOR IMAGERY SHOWS A
TROUGH DIGGING INTO THE GULF OF MEXICO WITH A NOTABLE SHORTWAVE
ACROSS THE NW GULF. THIS WILL MOVE ESE AND ACROSS FLORIDA ON
SUNDAY. IN ADVANCE OF THIS FEATURE...A SOUTHEAST WIND IS PUMPING
MOISTURE INTO THE AREA. MID LEVELS HAVE COOLED...AND WITH THE
MOIST, UNSTABLE ATMOSPHERE...WAVES OF SHOWERS AND A FEW
THUNDERSTORMS HAVE BEEN DEVELOPING ACROSS SOUTH FLORIDA THIS
AFTERNOON.
NOTING A COUPLE OF BANDS OF HEFTY SHOWERS/STORMS SETTING UP
RECENTLY...ONE OVER METRO BROWARD AND ANOTHER FORMING JUST OFF
MIAMI BEACH. WILL NEED TO WATCH THESE AS TRAINING CELLS WITHIN
THESE BANDS COULD RESULT IN LOCALIZED FLOODING.
FOR TONIGHT-SUNDAY...NUMEROUS TO WIDESPREAD SHOWERS AND A FEW
THUNDERSTORMS WILL BE THE RULE IN ADVANCE OF THE SHORTWAVE.
MOISTURE WILL REMAIN HIGH AND INSTABILITY JUST ENOUGH FOR
A FEW THUNDERSTORMS. HELICITY DOES LOOK TO INCREASE LATE TONIGHT-
EARLY SUNDAY MORNING...BUT ANY SEVERE RISK IS LOOKING EXTREMELY
LOW AT THIS POINT...GIVEN THE OVERCAST SKIES AND CONVECTIVE
OVERTURNING OF THE ATMOSPHERE. SO THE MAIN RISK TO HIGHLIGHT IS
THE POTENTIAL FOR LOCALLY HEAVY RAINFALL LEADING TO STREET
FLOODING.
THE FRONT GETS A PUSH SOUTHWARD SUNDAY EVENING...AND PASSES ACROSS
SOUTH FL DURING THE EVENING PER GFS AND SLIGHTLY LATER PER ECWMF.
RAIN/TSTORMS ACTIVITY WILL GET SHUNTED OFF THE SOUTHEAST COAST AS
IT PASSES WITH COOLER AND MUCH LESS HUMID AIR FLOWING INTO SOUTH
FLORIDA ON NORTHERLY WINDS BEHIND THE FRONT. THIS WILL DROP TEMPS
FINALLY BELOW 70F FOR THE FIRST TIME THIS FALL FOR FORT LAUDERDALE
AND MIAMI (RECORD LATEST DATE!)
LOWS BY MONDAY MORNING WILL FEEL CHILLY AFTER SUCH A WARM, HUMID
FALL...WITH LOWS FALLING INTO THE 60S SOUTHEAST LOCALES TO THE
50S FROM THE NAPLES AREA TO THE LAKE OKEECHOBEE REGION. HIGHS
TUESDAY WILL ONLY RANGE FROM AROUND 70F NEAR LAKE OKEECHOBEE TO
THE MID 70S SOUTHEAST COAST. TEMPS WILL GRADUALLY WARM DURING THE
MIDDLE PART OF NEXT WEEK. A BREEZY NE-E WIND FLOW WILL PERSIST
NEXT WEEK AND WITH DEWPOINTS IN THE 60S...IT WILL FEEL NICE. A
FEW SHOWERS LOOK TO DEVELOP AND MOVE ONSHORE THE EAST COAST NEXT
WEEK AS LOW LEVEL MOISTURE INCREASES...BUT THEY WILL BE QUICK
PASSING WITH MOST LOCALES REMAINING DRY MOST OF THE TIME.
THE PERSISTENT STRONG ONSHORE WINDS ALONG THE ATLANTIC COAST NEXT
WEEK WILL RESULT IN A HIGH RISK OF RIP CURRENTS AT THE ATLANTIC
BEACHES EXTENDING THROUGH MUCH OF NEXT WEEK. /GREGORIA
MARINE...
WINDS WILL BE ON THE INCREASE OUT OF THE SOUTH TO SOUTHEAST OVER
THE WATERS OVERNIGHT, BECOMING SOUTHWESTERLY ON SUNDAY THEN
NORTHERLY BEHIND A COLD FRONTAL PASSAGE SUNDAY NIGHT-MONDAY. SEAS
WILL RAPIDLY INCREASE SUNDAY NIGHT TO 7-9 FEET OVER THE OFFSHORE
GULF WATERS AND 9+ FEET IN THE GULF STREAM. WINDS WILL TURN
NORTHEASTERLY BY TUESDAY, THEN CONTINUE E-NE THROUGH LATE NEXT
WEEK WITH A FRESH BREEZE PREVAILING.
THE NEXT HIGH TIDE CYCLE IS COMING UP NEXT WEEK, WITH HIGHEST
ASTRONOMICAL TIDES ON WEDNESDAY AND THANKSGIVING DAY. NUISANCE
TIDAL FLOODING COULD BE AN ISSUE FOR MOST OF THE UPCOMING WEEK AND
POSSIBLY EXACERBATED BY THE PERSISTENT ONSHORE WINDS ALONG THE
ATLANTIC COAST. STILL TOO EARLY TO TELL WHETHER WE`LL SEE ANY
TIDAL FLOODING BUT THE POSSIBILITY CERTAINLY EXISTS AND WE`LL KEEP
A CLOSE EYE ON IT DURING THE NEXT SEVERAL DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 72 82 62 74 / 80 80 50 10
FORT LAUDERDALE 73 84 62 75 / 80 80 60 20
MIAMI 74 84 67 77 / 80 80 60 20
NAPLES 72 81 59 73 / 80 80 50 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MIAMI FL
114 AM EST FRI NOV 20 2015
.AVIATION...
FEW SHOWERS IN VICINITY OF KPBI EARLY THIS MORNING...BUT EXPECTED
SCATTERED ACTIVITY TO IMPACT ALL TERMINALS BY SUNRISE...WITH
SHOWER CHANCES HIGH ENOUGH TO WARRANT VCSH THROUG THE PERIOD.
OVERALL VFR CONDITIONS PREVAIL...BUT SOME MVFR CIGS/VSBY PSBL AT
TIMES. GENERAL NE WIND AOB 10 KT FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 803 PM EST THU NOV 19 2015/
UPDATE...
MINOR UPDATE TO THE GRIDS THIS EVENING, MAINLY TO ADJUST POPS FOR
CURRENT CONDITIONS. THE HRRR IS INDICATING THAT THE EAST COAST MAY
SEE LESS SHOWERS OVERNIGHT THAN PREVIOUSLY THOUGHT. HOWEVER, MOST
POPS WERE ONLY SLIGHT CHANCE TO CHANCE ANYWAYS, AND GIVEN
CONTINUED UNCERTAINTY LATER TONIGHT, HAVE LEFT FORECAST RIDE.
OTHERWISE, THE FORECAST IS PRETTY MUCH ON TRACK THIS EVENING.
PREV DISCUSSION... /ISSUED 432 PM EST THU NOV 19 2015/
DISCUSSION...
THE MAIN STORY FOR TODAY IS THE APPROACHING COLD FRONT. IT HAS
PUSHED HIGH PRESSURE TO THE EAST, BRINGING A MORE SOUTH TO
SOUTHEASTERLY FLOW TO SOUTH FLORIDA. MOISTURE HAS REMAINED OVER
THE AREA, AND SHOWERS HAVE BEEN THE RESULT. SOME ISOLATED
THUNDERSTORMS WILL ALSO BE POSSIBLE THIS EVENING.
THE FRONT WILL MOVE INTO CENTRAL FLORIDA AND SLOWLY APPROACH THE
CWA TONIGHT. BY MID-DAY TOMORROW, THE FRONT WILL STALL, PROBABLY
JUST NORTH OF THE LAKE. THIS WILL KEEP MOISTURE AND INSTABILITY
OVER SOUTH FLORIDA THROUGH THE WEEKEND. THERE DOES LOOK TO BE
ABUNDANT CLOUD COVER ASSOCIATED WITH THE FRONT. THIS WILL POSSIBLY
SOMEWHAT HINDER CONVECTIVE DEVELOPMENT WHILE THE FRONT IS AROUND.
BUT, THIS MAY ONLY KEEP MOST CONVECTION FROM DEVELOPING INTO
THUNDERSTORMS. PWATS THROUGH AT LEAST SATURDAY WILL BE AROUND 2
INCHES. THERE WILL ALSO BE A JET STREAK MOVING OVER CENTRAL
FLORIDA BY LATE TOMORROW. THIS COULD HELP GENERATE SOME HEAVY RAIN
OVERNIGHT FRIDAY INTO SATURDAY. THERE IS, OF COURSE, UNCERTAINTY
WITH TIMING AND LOCATION OF THE JET, AND ANY SMALL CHANGE WILL
CHANGE THIS. STILL HAVE SCATTERED SHOWERS FOR MOST OF THE WEEKEND,
ALONG WITH A SLIGHT CHANCE OF THUNDERSTORMS.
BY SATURDAY EVENING, ANOTHER JET MAY MOVE INTO THE AREA. THE GFS
KEEP IT FURTHER NORTH, BUT THE ECMWF BRINGS IT CLOSE ENOUGH THAT
IT BRINGS ADDITIONAL CHANCES OF HEAVY RAIN. LOOKING AT THE 5 DAY
PRECIP TOTAL FROM WPC, THE HEAVIEST ACCUMULATIONS WILL BE WELL OFF
SHORE OF THE TREASURE COAST. BUT, THEY STILL HAVE 2 INCHES OVER
PORTIONS OF THE CWA OVER THE NEXT 5 DAYS. THE 24 HOUR TOTALS ARE
GENERALLY BETWEEN A HALF INCH AND ONE INCH. SO, HAVE KEPT THINGS
JUST AS TYPICAL SCATTERED SHOWERS FOR NOW.
THE FRONT WILL BEGIN TO PUSH THROUGH ON SUNDAY. THIS WILL HAVE THE
POTENTIAL TO BE THE BUSIEST WEATHER DAY, AS THE FRONT WILL BE
FAIRLY STRONG. THE PWATS WILL GO FROM AROUND 2 INCHES AHEAD OF IT
DOWN TO AROUND THREE QUARTERS OF AN INCH BEHIND IT. THE MODELS ARE
INDICATING THE FRONT SHOULD BE THROUGH THE CWA IN THE MIDDLE OF
THE NIGHT, SUNDAY NIGHT. THE WIND SLOWLY PICKS UP, GENERALLY
BEHIND THE FRONT. THE BIGGEST QUESTION IS HOW WILL THE CLOUD COVER
AFFECT THE CONVECTION ASSOCIATED WITH THE FRONT. CURRENTLY, WENT
WITH LIKELY POPS SUNDAY. LIKELY SOME SCATTERED SHOWERS AHEAD OF
THE FRONT, AND A LINE OF SHOWERS, POSSIBLY THUNDERSTORMS, ALONG
THE FRONT.
BEHIND THE FRONT, A COOLER, DRIER AIR MASS SETTLES IN. FORECAST
HIGHS MONDAY ARE IN THE LOW TO MID 70S, WITH DEW POINTS IN THE 50S
AND 60S. BY TUESDAY MORNING, THE FORECAST LOWS ARE ARE IN THE MID
50S TO LOW 60S ACROSS SOUTH FLORIDA, WITH THE COLDER TEMPS WEST OF
THE LAKE. AS HIGH PRESSURE SETTLES IN TO THE NORTH, BEHIND THE
FRONT, WE WILL SEE AN EASTERLY FLOW RETURN, AS WELL AS A GRADUAL
WARM UP BY THE END OF THE WEEK.
MARINE...
A COLD FRONT WILL STALL JUST TO THE NORTH OF THE AREA BY TOMORROW.
THIS WILL BRING CONTINUED UNSETTLED WEATHER TO ALL SOUTH FLORIDA
WATERS OVER THE WEEKEND. THE FRONT WILL PUSH THROUGH THE AREA
SUNDAY NIGHT. THIS WILL BRING A SIGNIFICANT INCREASE IN WINDS AND
WILL LIKELY CAUSE HAZARDOUS MARINE CONDITIONS FOR ALL SOUTH
FLORIDA WATERS BY MONDAY, AS WELL AS BRING THE RETURN OF A HIGH
RISK OF RIP CURRENTS TO THE ATLANTIC BEACHES BY MONDAY, FOR A GOOD
PART OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 74 82 71 84 / 50 70 70 70
FORT LAUDERDALE 73 82 72 85 / 50 70 70 70
MIAMI 73 83 73 84 / 50 60 70 60
NAPLES 71 82 72 81 / 40 60 70 60
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...60/BD
LONG TERM....60/BD
AVIATION...23/SK
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1048 PM EST SAT NOV 21 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TONIGHT. COLDER
AND DRIER AIR WILL FILTER INTO THE REGION BEHIND THE FRONT...AS
HIGH PRESSURE SETTLES INTO THE REGION THROUGH TUESDAY. DRY
WEATHER EXPECTED TO CONTINUE MID TO LATE WEEK...AS HIGH PRESSURE
REMAINS OVER THE EASTERN SEABOARD...WITH MODERATING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SOUTHWESTERLY FLOW ALOFT WILL CONTINUE OVER THE FORECAST AREA
THROUGH THE OVERNIGHT PERIOD. WEAK ISENTROPIC LIFT IS SUPPORTING
SCATTERED LIGHT RAIN SHOWERS MAINLY IN THE EASTERN PART OF THE AREA
TONIGHT. SURFACE COLD FRONT THAT WILL MOVE THROUGH THE REGION LATE
TONIGHT IS NEAR THE APPALACHIANS AS OF 03Z. WINDS WILL INCREASE
TOWARD 12Z AS THE PRESSURE GRADIENT TIGHTENS BEHIND THE FRONT.
RAIN CHANCES WILL DIMINISH FROM SOUTHWEST TO NORTHEAST LATE TONIGHT
AS THE FRONT PUSHES THROUGH AND THE BEST DYNAMICS SHIFT FURTHER OFF
TO THE NORTH AND EAST. HAVE GENERALLY GONE WITH CHANCE POPS INTO
EARLY PORTIONS OF TONIGHT...WITH COVERAGE SCATTERED. RAINFALL
AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO REMAIN ON THE LIGHT SIDE.
THE HRRR SHOWS ANOTHER BAND OF RAINFALL MOVING INTO MAINLY THE
EASTERN PORTION OF THE FORECAST AREA FROM SOUTH TO NORTH AROUND 10Z
WHICH APPEARS TO BE ASSOCIATED WITH SHORTWAVE ENERGY. HAVE CONTINUED
WITH A SLIGHT CHANCE MAINLY EAST THROUGH 12Z.
TEMPERATURES SLOWLY FALLING WITH THE RAINFALL TONIGHT SO HAVE
ADJUSTED CURRENT FORECAST. OVERNIGHT LOWS IN THE MID 40S TO NEAR 50.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
ANOTHER UPPER VORT/JET STREAK WILL SHIFT SE AND DEEPEN THE UPPER
TROUGH AND SHIFT IT INTO THE E CONUS SUN/SUN NT....WITH TROUGH
AXIS PASSING THROUGH OUR REGION SUN NT. THIS WILL LEAD TO AN
INCREASING AND SLIGHTLY BACKING SW FLOW ALOFT FOR OUR REGION
TONIGHT INTO EARLY SUNDAY THAT APPEARS WILL SLOW THE COLD FRONTAL
PASSAGE. GUIDANCE CONSENSUS INDICATES PRECIPITATION MAY NOT EXIT
THE SE FA UNTIL SUNDAY AFTERNOON. AS A RESULT...MAINTAINED POPS
OVER EXTREME ERN PORTIONS OF THE FA INTO EARLY SUNDAY AFTERNOON.
BEHIND THE FRONT...A COOL DRY AIR HIGH PRESSURE AIR MASS WILL
SETTLE INTO OUR REGION. GUIDANCE SUGGESTS MIN TEMPS NEAR OR BELOW
FREEZING SUN AND MON NT. FROST/FREEZE PROGRAM FOR NWS CAE FA HAS
ENDED FOR THIS FALL SEASON.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
NEARLY ZONAL FLOW ALOFT TUESDAY...BUT WILL GIVE WAY TO A BUILDING
UPPER RIDGE OVER THE SOUTHEAST WEDNESDAY THROUGH FRIDAY. SURFACE
HIGH PRESSURE TO REMAIN OVER THE EASTERN SEABOARD. THIS WILL
MAINTAIN FAIR WEATHER FOR OUR REGION WITH MODERATING TEMPERATURES.
LATEST GFS INDICATING SURFACE FRONT SHIFTING EAST INTO THE
APPALACHIANS BY SATURDAY. BOTH GFS AND WPC GUIDANCE SUGGESTING
HIGH CHANCE POPS FOR SATURDAY...BUT GIVEN CURRENT
UNCERTAINTIES...FOR NOW WILL JUST MENTION SLIGHT CHANCE POPS FOR
SATURDAY.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
EXPECT MAINLY MVFR CONDITIONS THROUGH MUCH OF THE MORNING.
MOISTURE WILL REMAIN HIGH ASSOCIATED WITH A COLD FRONT IN THE AREA
PLUS A MID-LEVEL SHORTWAVE TROUGH. OBSERVATION TRENDS SUPPORT
MAINLY MVFR CONDITIONS. MAINTAINED RESTRICTIONS LONGER THAN THE
GFS AND NAM MOS BASED ON THE HRRR WHICH HAD RAIN BECOMING MORE
WIDESPREAD TOWARD 10Z AND LINGERING UNTIL AROUND 15Z. ALSO...THE
MODELS DO NOT SHOW THE H85 TROUGH SHIFTING EAST OF THE AREA UNTIL
THE EARLY AFTERNOON. CLOUDINESS SHOULD DIMINISH DURING THE
AFTERNOON BEHIND THE TROUGH. THE NAM AND GFS MOS SUPPORT DAYTIME
WINDS NORTH NEAR 10 KNOTS.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
DURING THE REST OF THE OUTLOOK PERIOD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1044 PM EST SAT NOV 21 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TONIGHT. COLDER
AND DRIER AIR WILL FILTER INTO THE REGION BEHIND THE FRONT...AS
HIGH PRESSURE SETTLES INTO THE REGION THROUGH TUESDAY. DRY
WEATHER EXPECTED TO CONTINUE MID TO LATE WEEK...AS HIGH PRESSURE
REMAINS OVER THE EASTERN SEABOARD...WITH MODERATING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SOUTHWESTERLY FLOW ALOFT WILL CONTINUE OVER THE FORECAST AREA
THROUGH THE OVERNIGHT PERIOD. WEAK ISENTROPIC LIFT IS SUPPORTING
SCATTERED LIGHT RAIN SHOWERS MAINLY IN THE EASTERN PART OF THE AREA
TONIGHT. SURFACE COLD FRONT THAT WILL MOVE THROUGH THE REGION LATE
TONIGHT IS NEAR THE APPALACHIANS AS OF 03Z.
RAIN CHANCES WILL DIMINISH FROM SOUTHWEST TO NORTHEAST LATE TONIGHT
AS THE FRONT PUSHES THROUGH AND THE BEST DYNAMICS SHIFT FURTHER OFF
TO THE NORTH AND EAST. HAVE GENERALLY GONE WITH CHANCE POPS INTO
EARLY PORTIONS OF TONIGHT...WITH COVERAGE SCATTERED. RAINFALL
AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO REMAIN ON THE LIGHT SIDE.
THE HRRR SHOWS ANOTHER BAND OF RAINFALL MOVING INTO MAINLY THE
EASTERN PORTION OF THE FORECAST AREA FROM SOUTH TO NORTH AROUND 10Z
WHICH APPEARS TO BE ASSOCIATED WITH SHORTWAVE ENERGY. HAVE CONTINUED
WITH A SLIGHT CHANCE MAINLY EAST THROUGH 12Z.
TEMPERATURES SLOWLY FALLING WITH THE RAINFALL TONIGHT SO HAVE
ADJUSTED CURRENT FORECAST. OVERNIGHT LOWS IN THE MID 40S TO NEAR 50.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
ANOTHER UPPER VORT/JET STREAK WILL SHIFT SE AND DEEPEN THE UPPER
TROUGH AND SHIFT IT INTO THE E CONUS SUN/SUN NT....WITH TROUGH
AXIS PASSING THROUGH OUR REGION SUN NT. THIS WILL LEAD TO AN
INCREASING AND SLIGHTLY BACKING SW FLOW ALOFT FOR OUR REGION
TONIGHT INTO EARLY SUNDAY THAT APPEARS WILL SLOW THE COLD FRONTAL
PASSAGE. GUIDANCE CONSENSUS INDICATES PRECIPITATION MAY NOT EXIT
THE SE FA UNTIL SUNDAY AFTERNOON. AS A RESULT...MAINTAINED POPS
OVER EXTREME ERN PORTIONS OF THE FA INTO EARLY SUNDAY AFTERNOON.
BEHIND THE FRONT...A COOL DRY AIR HIGH PRESSURE AIR MASS WILL
SETTLE INTO OUR REGION. GUIDANCE SUGGESTS MIN TEMPS NEAR OR BELOW
FREEZING SUN AND MON NT. FROST/FREEZE PROGRAM FOR NWS CAE FA HAS
ENDED FOR THIS FALL SEASON.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
NEARLY ZONAL FLOW ALOFT TUESDAY...BUT WILL GIVE WAY TO A BUILDING
UPPER RIDGE OVER THE SOUTHEAST WEDNESDAY THROUGH FRIDAY. SURFACE
HIGH PRESSURE TO REMAIN OVER THE EASTERN SEABOARD. THIS WILL
MAINTAIN FAIR WEATHER FOR OUR REGION WITH MODERATING TEMPERATURES.
LATEST GFS INDICATING SURFACE FRONT SHIFTING EAST INTO THE
APPALACHIANS BY SATURDAY. BOTH GFS AND WPC GUIDANCE SUGGESTING
HIGH CHANCE POPS FOR SATURDAY...BUT GIVEN CURRENT
UNCERTAINTIES...FOR NOW WILL JUST MENTION SLIGHT CHANCE POPS FOR
SATURDAY.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
EXPECT MAINLY MVFR CONDITIONS THROUGH MUCH OF THE MORNING.
MOISTURE WILL REMAIN HIGH ASSOCIATED WITH A COLD FRONT IN THE AREA
PLUS A MID-LEVEL SHORTWAVE TROUGH. OBSERVATION TRENDS SUPPORT
MAINLY MVFR CONDITIONS. MAINTAINED RESTRICTIONS LONGER THAN THE
GFS AND NAM MOS BASED ON THE HRRR WHICH HAD RAIN BECOMING MORE
WIDESPREAD TOWARD 10Z AND LINGERING UNTIL AROUND 15Z. ALSO...THE
MODELS DO NOT SHOW THE H85 TROUGH SHIFTING EAST OF THE AREA UNTIL
THE EARLY AFTERNOON. CLOUDINESS SHOULD DIMINISH DURING THE
AFTERNOON BEHIND THE TROUGH. THE NAM AND GFS MOS SUPPORT DAYTIME
WINDS NORTH NEAR 10 KNOTS.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
DURING THE REST OF THE OUTLOOK PERIOD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1137 AM CST FRI NOV 20 2015
.UPDATE...
ISSUED AT 1129 AM CST FRI NOV 20 2015
VERY LIGHT SNOW HAS DEVELOPED IN BENTON COUNTY NEAR VINTON AND IS ALSO
BEING REPORTED IN METRO CEDAR RAPIDS. AS A RESULT THE OVERALL TIMING
OF PRECIPITATION HAS BEEN SPED UP.
THE EVAPORATIVE COOLING DUE TO THE STRONG FORCING IS ALLOWING
PRECIPITATION TO BE ALL SNOW ONCE IT REACHES THE GROUND. THIS SNOW
IS OCCURRING THE THE NARROW BAND ACROSS NORTHERN IOWA INTO EASTERN
IOWA PER RADAR. IMMEDIATE SHORT TERM TRENDS INDICATE THIS BAND
WILL SLOWLY LIFT TO THE EAST NORTHEAST THROUGH EARLY AFTERNOON. AS
THE SATURATION PROCESS BECOMES MORE EFFICIENT...PRECIPITATION IS
EXPECTED TO QUICKLY BREAK OUT ACROSS EASTERN IOWA FROM MID TO
LATE AFTERNOON.
&&
.SYNOPSIS...
ISSUED AT 328 AM CST FRI NOV 20 2015
CURRENT SATELLITE IMAGERY DEPICTS CLEAR SKIES TONIGHT AS HIGH
PRESSURE IS IN PLACE ACROSS THE REGION. AT THE SFC...DRY AIR IS IN
PLACE WITH DEWPOINTS IN THE LOW 20S TO UPPER TEENS. OVER THE FAR
NORTHERN CONUS ROCKY MOUNTAINS...AN UPPER LEVEL WAVE WAS MOVING SE
INTO THE HIGH PLAINS. THIS WAVE IS EXPECTED TO BRING OUR FIRST
WINTER STORM TO THE AREA LATER TODAY AND OVERNIGHT AND INTO SATURDAY
MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CST FRI NOV 20 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM IS THE IMPENDING WINTER
STORM TO AFFECT THE AREA TODAY AND TONIGHT. OVERALL FORECAST HAS
CHANGED LITTLE WITH THE MOST NOTABLE CHANGE WITH A SHIFT SOUTH OF
THE HEAVY SNOW AXIS. GUIDANCE SUGGESTS THAT PRECIP COULD START AS
EARLY AS 18Z ACROSS THE FAR NORTHERN ZONES. OVERALL NO CHANGES TO
THE CURRENT HEADLINES WERE MADE.
H5 WAVE IS FORECAST TO MOVE INTO THE CENTRAL PLAINS BY 18Z TODAY.
MODELS ARE CONSISTENT WITH THE PLACEMENT OF THE MAIN FORCING. THE
GFS IS THE FASTEST OF THE OPERATIONAL MODELS AND THIS SEEMS TO BE
SLIGHTLY SLOWER THAN THE GEFS ENSEMBLE MEAN. BETWEEN 00Z AND 12Z
SATURDAY A H3 JET IS EXPECTED TO PASS TO OUR SOUTH WITH THE
FAVORABLE LEFT EXIT REGION OVER OUR AREA. THIS WILL HELP TO
INCREASE VERTICAL MOTION FROM 00Z TO 12Z SATURDAY. THE H85 LOW
CENTER IS FORECAST TO MOVE JUST TO OUR SOUTH THROUGH THE PERIOD
WITH THE MAJORITY OF THE CWA IN THE BELOW FREEZING SIDE.
MODEL SOUNDINGS ARE INDICATIVE OF SNOW AS SOON AS EVAPORATIVE
COOLING RAPIDLY COOLS THE LOW LEVELS. ONSET OF PRECIP LOOKS TO BE
RAIN AT FIRST...QUICKLY CHANGING TO RASN AND THEN OVER TO ALL SN
SHORTLY AFTER THIS.
TIMING...HIRES GUIDANCE IS HINTING AT A BAND OF PRECIP ACROSS FAR
NORTHERN ZONES AS EARLY AS 18Z. THIS BAND MAY BE LIGHT AT FIRST
AND MAY TAKE SOME TIME TO COOL/MOISTEN UP THE BL BEFORE PRECIP
STARTS TO FALL. THE REST OF THE AREA WILL SEE THE PRECIP START
FROM WEST TO EAST. THE BEST CHANCE FOR ONSET IN THE WEST WILL BE
BETWEEN 20Z AND 22Z. MULTIPLE HRRR RUNS ARE CONSISTENT IN THIS
TIMING. THE HRRR AND OTHER CAMS SUGGEST A 23Z TO 01Z START TIME
FOR THE AREAS ALONG THE MISSISSIPPI RIVER. AREAS ACROSS IL COULD
SEE PRECIP START AS SOON AS 00Z...BUT LIKELY 01Z TO 02Z.
SNOWFALL TOTALS HAVE NOT CHANGED ALL THE MUCH. WITH THE LATEST
GUIDANCE AND TRENDS FROM DPROG DT...IT APPEARS THAT THE HEAVIEST
SNOW HAS SHIFTED SOUTH SOME 40 MILES. THIS PUTS A ROCKFORD TO
CLINTON TO IOWA CITY LINE AS OUR CURRENT BEST GUESS FOR THE
HEAVIEST SNOW AXIS. TOTALS OF UP TO TEN INCHES OR MORE COULD BE
POSSIBLE ALONG THE AXIS.
SOME CONCERNS ABOUT THE FORECAST ARE THE WARM GROUND TEMPS AND THE
EFFECTS OF EVAPORATIVE COOLING. WHILE THE QPF AND SNOW RATIOS
SUPPORT THIS MUCH SNOW...THERE IS A POSSIBILITY THAT THE WARM
GROUND WILL MELT SNOW AND LEAD TO LESS ACCUMULATION THAN FORECAST.
THIS NEEDS TO BE KEPT IN MIND. REGARDLESS OF THE ACTUAL
TOTALS...IMPACTS FROM THIS STORM WILL LIKELY CAUSE DRIVING ISSUES
AS THE SNOW RATE MAY MAKE IT DIFFICULT TO KEEP ROADS CLEARED
...ESPECIALLY LATER AT NIGHT AND IN THE HEAVIER BANDS. THERE ARE
SOME CONCERNS ABOUT ICE FORMING ON UNTREATED ROADWAYS SO BE SURE
TO DRIVE CAUTIOUSLY IF YOU MUST BE OUT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 328 AM CST FRI NOV 20 2015
INITIAL FOCUS IS ON THE EXITING WINTER STORM SATURDAY MORNING...
WHICH WILL BE FOLLOWED BY BITTER COLD TEMPERATURES THROUGH SUNDAY. A
RETURN TO A MORE ZONAL UPPER LEVEL FLOW NEXT WEEK WILL RESULT IN
TEMPERATURES RECOVERING BACK TO NEAR NORMAL WITH INCREASING RAIN
CHANCES IN THE LATTER HALF OF THE WEEK AS GULF MOISTURE RETURNS.
MODEL CONSENSUS HAS THE SURFACE LOW OVER W CENTRAL IL AT 12Z
DEEPENING AND EJECTING NORTHEAST INTO THE GREAT LAKES WITH THE
PASSAGE OF THE UPPER LEVEL VORT MAX FOLLOWED BY ISENTROPIC DOWNGLIDE
AND BRISK WINDS BEHIND THE SYSTEM. THE TIMING OF THE BACK EDGE OF
THE SYSTEM AND THE PASSING DEFORMATION AXIS NW OF THE SURFACE AND
850 MB LOWS HAS BEEN FAIRLY CONSISTENT OVER THE PAST SEVERAL MODEL
RUNS. THIS SUGGESTS ADDITIONAL 1 TO 2 INCH ACCUMULATIONS WILL BE
POSSIBLE PRIMARILY OVER NW IL...WITH TRACE TO QUARTER INCH AMOUNTS
FURTHER WEST AND SOUTH. HOWEVER...EVEN WITHOUT SIGNIFICANT
SNOW...BRISK N-NW WINDS OF 15 TO 25 MPH...POSSIBLY INTO THE 30 MPH
RANGE...MAY CAUSE SOME DRIFTING SNOW ACROSS THE WEST THROUGH THE
MORNING AND WILL KEEP THE CURRENT 18Z EXPIRATION TIME OF THE
HEADLINES GOING FOR NOW. STRONG COLD AIR ADVECTION AND FRESH
SNOWFALL WILL LEAD TO A WINTER-LIKE DAY WITH TEMPERATURES STEADY TO
FALLING THROUGH THE MID TO UPPER 20S EVEN AS THE DEVELOPING LOW
LEVEL ANTICYCLONIC FLOW LEADS TO BREAKS OF SUNSHINE BY AFTERNOON.
SATURDAY NIGHT AND SUNDAY...LIGHTER SURFACE WINDS WITH THE PASSAGE
OF RIDGE AXIS WILL ALLOW MIN TEMPERATURES TO PLUNGE INTO THE SINGLE
DIGITS OVER THE EXPECTED DEEPER SNOW COVERED CENTRAL AND
NORTH...WITH TEENS MAINLY SOUTH OF THE HIGHWAY 34 CORRIDOR.
TEMPERATURES COULD POTENTIALLY END UP EVEN COLDER...DEPENDING ON THE
AMOUNT OF CLOUD COVER IN THE CYCLONIC NW FLOW ALOFT. LITTLE CHANGE
IN THE SURFACE AIRMASS IS EXPECTED FOR SUNDAY UNDER A NW FLOW ALOFT
WITH HIGHS FROM THE MID 20S NE TO THE MID 30S SW
A GRADUAL WARMUP FOLLOWS FOR MONDAY THROUGH WED AS THE UPPER LEVEL
TROUGH MOVES EAST ALLOWING TO A MORE ZONAL FLOW TO DEVELOP OVER THE
CENTRAL U.S. THIS WILL LEAD TO HIGH TEMPERATURES RECOVERING FROM IN
THE 30S MONDAY...BACK TO NEAR LATE NOVEMBER NORMALS IN THE 40S BY
WED. THE NEXT SYSTEM MOVING INTO THE WEST WILL SEND ANOTHER ROUND OF
GULF MOISTURE NORTHWARD FOR INCREASING RAIN CHANCES WED NIGHT
THROUGH FRIDAY WITH TEMPERATURES LIKELY TRENDING NEAR TO ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1129 AM CST FRI NOV 20 2015
VFR CONDITIONS WILL RAPIDLY DETERIORATE TO MVFR/IFR CONDITIONS BY
00Z/21 WITH SNOW. THERE MAY BE A BRIEF PERIOD OF A RAIN/SNOW MIX
BEFORE IT QUICKLY CHANGES OVER TO ALL SNOW. THE EXCEPTION MAY BE
KBRL WHERE A RAIN/SNOW MIX MAY HOLD ON A BIT LONGER. WIDESPREAD
LIFR CONDITIONS WITH SNOW ARE EXPECTED SHORTLY AFTER 00Z/21.
CONDITIONS WILL BEGIN IMPROVING TO IFR AND EVENTUALLY VFR AFT
12Z/21.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER STORM WARNING FROM 6 PM THIS EVENING TO NOON CST SATURDAY
FOR BENTON-BUCHANAN-CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-
JACKSON-JOHNSON-JONES-KEOKUK-LINN-LOUISA-MUSCATINE-SCOTT-
WASHINGTON.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
SATURDAY FOR DES MOINES-HENRY IA-JEFFERSON-LEE-VAN BUREN.
IL...WINTER STORM WARNING FROM 6 PM THIS EVENING TO NOON CST SATURDAY
FOR BUREAU-CARROLL-HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK
ISLAND-STEPHENSON-WHITESIDE.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
SATURDAY FOR HANCOCK-HENDERSON-MCDONOUGH-WARREN.
MO...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
SATURDAY FOR CLARK-SCOTLAND.
&&
$$
UPDATE...08
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...SHEETS
AVIATION...08
AREA FORECAST DISCUSSION...UPDATED
NWS QUAD CITIES IA IL
524 AM CST FRI NOV 20 2015
.SYNOPSIS...
ISSUED AT 328 AM CST FRI NOV 20 2015
CURRENT SATELLITE IMAGERY DEPICTS CLEAR SKIES TONIGHT AS HIGH
PRESSURE IS IN PLACE ACROSS THE REGION. AT THE SFC...DRY AIR IS IN
PLACE WITH DEWPOINTS IN THE LOW 20S TO UPPER TEENS. OVER THE FAR
NORTHERN CONUS ROCKY MOUNTAINS...AN UPPER LEVEL WAVE WAS MOVING SE
INTO THE HIGH PLAINS. THIS WAVE IS EXPECTED TO BRING OUR FIRST
WINTER STORM TO THE AREA LATER TODAY AND OVERNIGHT AND INTO SATURDAY
MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CST FRI NOV 20 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM IS THE IMPENDING WINTER
STORM TO AFFECT THE AREA TODAY AND TONIGHT. OVERALL FORECAST HAS
CHANGED LITTLE WITH THE MOST NOTABLE CHANGE WITH A SHIFT SOUTH OF
THE HEAVY SNOW AXIS. GUIDANCE SUGGESTS THAT PRECIP COULD START AS
EARLY AS 18Z ACROSS THE FAR NORTHERN ZONES. OVERALL NO CHANGES TO
THE CURRENT HEADLINES WERE MADE.
H5 WAVE IS FORECAST TO MOVE INTO THE CENTRAL PLAINS BY 18Z TODAY.
MODELS ARE CONSISTENT WITH THE PLACEMENT OF THE MAIN FORCING. THE
GFS IS THE FASTEST OF THE OPERATIONAL MODELS AND THIS SEEMS TO BE
SLIGHTLY SLOWER THAN THE GEFS ENSEMBLE MEAN. BETWEEN 00Z AND 12Z
SATURDAY A H3 JET IS EXPECTED TO PASS TO OUR SOUTH WITH THE
FAVORABLE LEFT EXIT REGION OVER OUR AREA. THIS WILL HELP TO
INCREASE VERTICAL MOTION FROM 00Z TO 12Z SATURDAY. THE H85 LOW
CENTER IS FORECAST TO MOVE JUST TO OUR SOUTH THROUGH THE PERIOD
WITH THE MAJORITY OF THE CWA IN THE BELOW FREEZING SIDE.
MODEL SOUNDINGS ARE INDICATIVE OF SNOW AS SOON AS EVAPORATIVE
COOLING RAPIDLY COOLS THE LOW LEVELS. ONSET OF PRECIP LOOKS TO BE
RAIN AT FIRST...QUICKLY CHANGING TO RASN AND THEN OVER TO ALL SN
SHORTLY AFTER THIS.
TIMING...HIRES GUIDANCE IS HINTING AT A BAND OF PRECIP ACROSS FAR
NORTHERN ZONES AS EARLY AS 18Z. THIS BAND MAY BE LIGHT AT FIRST
AND MAY TAKE SOME TIME TO COOL/MOISTEN UP THE BL BEFORE PRECIP
STARTS TO FALL. THE REST OF THE AREA WILL SEE THE PRECIP START
FROM WEST TO EAST. THE BEST CHANCE FOR ONSET IN THE WEST WILL BE
BETWEEN 20Z AND 22Z. MULTIPLE HRRR RUNS ARE CONSISTENT IN THIS
TIMING. THE HRRR AND OTHER CAMS SUGGEST A 23Z TO 01Z START TIME
FOR THE AREAS ALONG THE MISSISSIPPI RIVER. AREAS ACROSS IL COULD
SEE PRECIP START AS SOON AS 00Z...BUT LIKELY 01Z TO 02Z.
SNOWFALL TOTALS HAVE NOT CHANGED ALL THE MUCH. WITH THE LATEST
GUIDANCE AND TRENDS FROM DPROG DT...IT APPEARS THAT THE HEAVIEST
SNOW HAS SHIFTED SOUTH SOME 40 MILES. THIS PUTS A ROCKFORD TO
CLINTON TO IOWA CITY LINE AS OUR CURRENT BEST GUESS FOR THE
HEAVIEST SNOW AXIS. TOTALS OF UP TO TEN INCHES OR MORE COULD BE
POSSIBLE ALONG THE AXIS.
SOME CONCERNS ABOUT THE FORECAST ARE THE WARM GROUND TEMPS AND THE
EFFECTS OF EVAPORATIVE COOLING. WHILE THE QPF AND SNOW RATIOS
SUPPORT THIS MUCH SNOW...THERE IS A POSSIBILITY THAT THE WARM
GROUND WILL MELT SNOW AND LEAD TO LESS ACCUMULATION THAN FORECAST.
THIS NEEDS TO BE KEPT IN MIND. REGARDLESS OF THE ACTUAL
TOTALS...IMPACTS FROM THIS STORM WILL LIKELY CAUSE DRIVING ISSUES
AS THE SNOW RATE MAY MAKE IT DIFFICULT TO KEEP ROADS CLEARED
...ESPECIALLY LATER AT NIGHT AND IN THE HEAVIER BANDS. THERE ARE
SOME CONCERNS ABOUT ICE FORMING ON UNTREATED ROADWAYS SO BE SURE
TO DRIVE CAUTIOUSLY IF YOU MUST BE OUT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 328 AM CST FRI NOV 20 2015
INITIAL FOCUS IS ON THE EXITING WINTER STORM SATURDAY MORNING...
WHICH WILL BE FOLLOWED BY BITTER COLD TEMPERATURES THROUGH SUNDAY. A
RETURN TO A MORE ZONAL UPPER LEVEL FLOW NEXT WEEK WILL RESULT IN
TEMPERATURES RECOVERING BACK TO NEAR NORMAL WITH INCREASING RAIN
CHANCES IN THE LATTER HALF OF THE WEEK AS GULF MOISTURE RETURNS.
MODEL CONSENSUS HAS THE SURFACE LOW OVER W CENTRAL IL AT 12Z
DEEPENING AND EJECTING NORTHEAST INTO THE GREAT LAKES WITH THE
PASSAGE OF THE UPPER LEVEL VORT MAX FOLLOWED BY ISENTROPIC DOWNGLIDE
AND BRISK WINDS BEHIND THE SYSTEM. THE TIMING OF THE BACK EDGE OF
THE SYSTEM AND THE PASSING DEFORMATION AXIS NW OF THE SURFACE AND
850 MB LOWS HAS BEEN FAIRLY CONSISTENT OVER THE PAST SEVERAL MODEL
RUNS. THIS SUGGESTS ADDITIONAL 1 TO 2 INCH ACCUMULATIONS WILL BE
POSSIBLE PRIMARILY OVER NW IL...WITH TRACE TO QUARTER INCH AMOUNTS
FURTHER WEST AND SOUTH. HOWEVER...EVEN WITHOUT SIGNIFICANT
SNOW...BRISK N-NW WINDS OF 15 TO 25 MPH...POSSIBLY INTO THE 30 MPH
RANGE...MAY CAUSE SOME DRIFTING SNOW ACROSS THE WEST THROUGH THE
MORNING AND WILL KEEP THE CURRENT 18Z EXPIRATION TIME OF THE
HEADLINES GOING FOR NOW. STRONG COLD AIR ADVECTION AND FRESH
SNOWFALL WILL LEAD TO A WINTER-LIKE DAY WITH TEMPERATURES STEADY TO
FALLING THROUGH THE MID TO UPPER 20S EVEN AS THE DEVELOPING LOW
LEVEL ANTICYCLONIC FLOW LEADS TO BREAKS OF SUNSHINE BY AFTERNOON.
SATURDAY NIGHT AND SUNDAY...LIGHTER SURFACE WINDS WITH THE PASSAGE
OF RIDGE AXIS WILL ALLOW MIN TEMPERATURES TO PLUNGE INTO THE SINGLE
DIGITS OVER THE EXPECTED DEEPER SNOW COVERED CENTRAL AND
NORTH...WITH TEENS MAINLY SOUTH OF THE HIGHWAY 34 CORRIDOR.
TEMPERATURES COULD POTENTIALLY END UP EVEN COLDER...DEPENDING ON THE
AMOUNT OF CLOUD COVER IN THE CYCLONIC NW FLOW ALOFT. LITTLE CHANGE
IN THE SURFACE AIRMASS IS EXPECTED FOR SUNDAY UNDER A NW FLOW ALOFT
WITH HIGHS FROM THE MID 20S NE TO THE MID 30S SW
A GRADUAL WARMUP FOLLOWS FOR MONDAY THROUGH WED AS THE UPPER LEVEL
TROUGH MOVES EAST ALLOWING TO A MORE ZONAL FLOW TO DEVELOP OVER THE
CENTRAL U.S. THIS WILL LEAD TO HIGH TEMPERATURES RECOVERING FROM IN
THE 30S MONDAY...BACK TO NEAR LATE NOVEMBER NORMALS IN THE 40S BY
WED. THE NEXT SYSTEM MOVING INTO THE WEST WILL SEND ANOTHER ROUND OF
GULF MOISTURE NORTHWARD FOR INCREASING RAIN CHANCES WED NIGHT
THROUGH FRIDAY WITH TEMPERATURES LIKELY TRENDING NEAR TO ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 515 AM CST FRI NOV 20 2015
FIRST WINTER STORM THIS SEASON WILL AFFECT THE TAF SITES THROUGH
THIS PERIOD. WITH THE EXCEPTION OF POSSIBLY CID...ALL OTHER TAF
SITES WILL HAVE VFR FLIGHT RULES WITH NO WX THROUGH 21Z TODAY. RA
WILL TRANSITION TO RASN AND THEN SNOW QUICKLY AND AFFECT ALL THE
TAF SITES. SN+ WITH LESS THAN 1/4 VSBY WILL OCCUR...HOWEVER TIMING
OF THESE WINDOWS IS NOT GOOD SO WILL LEAVE THEM OUT UNTIL LATER.
THOSE FLYING LATER IN THE DAY AND OVERNIGHT SHOULD BE PREPARED FOR
IFR AND LIFR AND FROZEN PRECIP. SNOW SHOULD END FROM W TO E NEAR
DAYBREAK SAT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER STORM WARNING FROM 6 PM THIS EVENING TO NOON CST SATURDAY
FOR BENTON-BUCHANAN-CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-
JACKSON-JOHNSON-JONES-KEOKUK-LINN-LOUISA-MUSCATINE-SCOTT-
WASHINGTON.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
SATURDAY FOR DES MOINES-HENRY IA-JEFFERSON-LEE-VAN BUREN.
IL...WINTER STORM WARNING FROM 6 PM THIS EVENING TO NOON CST SATURDAY
FOR BUREAU-CARROLL-HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK
ISLAND-STEPHENSON-WHITESIDE.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
SATURDAY FOR HANCOCK-HENDERSON-MCDONOUGH-WARREN.
MO...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
SATURDAY FOR CLARK-SCOTLAND.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...SHEETS
AVIATION...GIBBS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
328 AM CST FRI NOV 20 2015
.SYNOPSIS...
ISSUED AT 328 AM CST FRI NOV 20 2015
CURRENT SATELLITE IMAGERY DEPICTS CLEAR SKIES TONIGHT AS HIGH
PRESSURE IS IN PLACE ACROSS THE REGION. AT THE SFC...DRY AIR IS IN
PLACE WITH DEWPOINTS IN THE LOW 20S TO UPPER TEENS. OVER THE FAR
NORTHERN CONUS ROCKY MOUNTAINS...AN UPPER LEVEL WAVE WAS MOVING SE
INTO THE HIGH PLAINS. THIS WAVE IS EXPECTED TO BRING OUR FIRST
WINTER STORM TO THE AREA LATER TODAY AND OVERNIGHT AND INTO SATURDAY
MORNING.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 328 AM CST FRI NOV 20 2015
MAIN FORECAST CONCERN FOR THE SHORT TERM IS THE IMPENDING WINTER
STORM TO AFFECT THE AREA TODAY AND TONIGHT. OVERALL FORECAST HAS
CHANGED LITTLE WITH THE MOST NOTABLE CHANGE WITH A SHIFT SOUTH OF
THE HEAVY SNOW AXIS. GUIDANCE SUGGESTS THAT PRECIP COULD START AS
EARLY AS 18Z ACROSS THE FAR NORTHERN ZONES. OVERALL NO CHANGES TO
THE CURRENT HEADLINES WERE MADE.
H5 WAVE IS FORECAST TO MOVE INTO THE CENTRAL PLAINS BY 18Z TODAY.
MODELS ARE CONSISTENT WITH THE PLACEMENT OF THE MAIN FORCING. THE
GFS IS THE FASTEST OF THE OPERATIONAL MODELS AND THIS SEEMS TO BE
SLIGHTLY SLOWER THAN THE GEFS ENSEMBLE MEAN. BETWEEN 00Z AND 12Z
SATURDAY A H3 JET IS EXPECTED TO PASS TO OUR SOUTH WITH THE
FAVORABLE LEFT EXIT REGION OVER OUR AREA. THIS WILL HELP TO
INCREASE VERTICAL MOTION FROM 00Z TO 12Z SATURDAY. THE H85 LOW
CENTER IS FORECAST TO MOVE JUST TO OUR SOUTH THROUGH THE PERIOD
WITH THE MAJORITY OF THE CWA IN THE BELOW FREEZING SIDE.
MODEL SOUNDINGS ARE INDICATIVE OF SNOW AS SOON AS EVAPORATIVE
COOLING RAPIDLY COOLS THE LOW LEVELS. ONSET OF PRECIP LOOKS TO BE
RAIN AT FIRST...QUICKLY CHANGING TO RASN AND THEN OVER TO ALL SN
SHORTLY AFTER THIS.
TIMING...HIRES GUIDANCE IS HINTING AT A BAND OF PRECIP ACROSS FAR
NORTHERN ZONES AS EARLY AS 18Z. THIS BAND MAY BE LIGHT AT FIRST
AND MAY TAKE SOME TIME TO COOL/MOISTEN UP THE BL BEFORE PRECIP
STARTS TO FALL. THE REST OF THE AREA WILL SEE THE PRECIP START
FROM WEST TO EAST. THE BEST CHANCE FOR ONSET IN THE WEST WILL BE
BETWEEN 20Z AND 22Z. MULTIPLE HRRR RUNS ARE CONSISTENT IN THIS
TIMING. THE HRRR AND OTHER CAMS SUGGEST A 23Z TO 01Z START TIME
FOR THE AREAS ALONG THE MISSISSIPPI RIVER. AREAS ACROSS IL COULD
SEE PRECIP START AS SOON AS 00Z...BUT LIKELY 01Z TO 02Z.
SNOWFALL TOTALS HAVE NOT CHANGED ALL THE MUCH. WITH THE LATEST
GUIDANCE AND TRENDS FROM DPROG DT...IT APPEARS THAT THE HEAVIEST
SNOW HAS SHIFTED SOUTH SOME 40 MILES. THIS PUTS A ROCKFORD TO
CLINTON TO IOWA CITY LINE AS OUR CURRENT BEST GUESS FOR THE
HEAVIEST SNOW AXIS. TOTALS OF UP TO TEN INCHES OR MORE COULD BE
POSSIBLE ALONG THE AXIS.
SOME CONCERNS ABOUT THE FORECAST ARE THE WARM GROUND TEMPS AND THE
EFFECTS OF EVAPORATIVE COOLING. WHILE THE QPF AND SNOW RATIOS
SUPPORT THIS MUCH SNOW...THERE IS A POSSIBILITY THAT THE WARM
GROUND WILL MELT SNOW AND LEAD TO LESS ACCUMULATION THAN FORECAST.
THIS NEEDS TO BE KEPT IN MIND. REGARDLESS OF THE ACTUAL
TOTALS...IMPACTS FROM THIS STORM WILL LIKELY CAUSE DRIVING ISSUES
AS THE SNOW RATE MAY MAKE IT DIFFICULT TO KEEP ROADS CLEARED
...ESPECIALLY LATER AT NIGHT AND IN THE HEAVIER BANDS. THERE ARE
SOME CONCERNS ABOUT ICE FORMING ON UNTREATED ROADWAYS SO BE SURE
TO DRIVE CAUTIOUSLY IF YOU MUST BE OUT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 328 AM CST FRI NOV 20 2015
INITIAL FOCUS IS ON THE EXITING WINTER STORM SATURDAY MORNING...
WHICH WILL BE FOLLOWED BY BITTER COLD TEMPERATURES THROUGH SUNDAY. A
RETURN TO A MORE ZONAL UPPER LEVEL FLOW NEXT WEEK WILL RESULT IN
TEMPERATURES RECOVERING BACK TO NEAR NORMAL WITH INCREASING RAIN
CHANCES IN THE LATTER HALF OF THE WEEK AS GULF MOISTURE RETURNS.
MODEL CONSENSUS HAS THE SURFACE LOW OVER W CENTRAL IL AT 12Z
DEEPENING AND EJECTING NORTHEAST INTO THE GREAT LAKES WITH THE
PASSAGE OF THE UPPER LEVEL VORT MAX FOLLOWED BY ISENTROPIC DOWNGLIDE
AND BRISK WINDS BEHIND THE SYSTEM. THE TIMING OF THE BACK EDGE OF
THE SYSTEM AND THE PASSING DEFORMATION AXIS NW OF THE SURFACE AND
850 MB LOWS HAS BEEN FAIRLY CONSISTENT OVER THE PAST SEVERAL MODEL
RUNS. THIS SUGGESTS ADDITIONAL 1 TO 2 INCH ACCUMULATIONS WILL BE
POSSIBLE PRIMARILY OVER NW IL...WITH TRACE TO QUARTER INCH AMOUNTS
FURTHER WEST AND SOUTH. HOWEVER...EVEN WITHOUT SIGNIFICANT
SNOW...BRISK N-NW WINDS OF 15 TO 25 MPH...POSSIBLY INTO THE 30 MPH
RANGE...MAY CAUSE SOME DRIFTING SNOW ACROSS THE WEST THROUGH THE
MORNING AND WILL KEEP THE CURRENT 18Z EXPIRATION TIME OF THE
HEADLINES GOING FOR NOW. STRONG COLD AIR ADVECTION AND FRESH
SNOWFALL WILL LEAD TO A WINTER-LIKE DAY WITH TEMPERATURES STEADY TO
FALLING THROUGH THE MID TO UPPER 20S EVEN AS THE DEVELOPING LOW
LEVEL ANTICYCLONIC FLOW LEADS TO BREAKS OF SUNSHINE BY AFTERNOON.
SATURDAY NIGHT AND SUNDAY...LIGHTER SURFACE WINDS WITH THE PASSAGE
OF RIDGE AXIS WILL ALLOW MIN TEMPERATURES TO PLUNGE INTO THE SINGLE
DIGITS OVER THE EXPECTED DEEPER SNOW COVERED CENTRAL AND
NORTH...WITH TEENS MAINLY SOUTH OF THE HIGHWAY 34 CORRIDOR.
TEMPERATURES COULD POTENTIALLY END UP EVEN COLDER...DEPENDING ON THE
AMOUNT OF CLOUD COVER IN THE CYCLONIC NW FLOW ALOFT. LITTLE CHANGE
IN THE SURFACE AIRMASS IS EXPECTED FOR SUNDAY UNDER A NW FLOW ALOFT
WITH HIGHS FROM THE MID 20S NE TO THE MID 30S SW
A GRADUAL WARMUP FOLLOWS FOR MONDAY THROUGH WED AS THE UPPER LEVEL
TROUGH MOVES EAST ALLOWING TO A MORE ZONAL FLOW TO DEVELOP OVER THE
CENTRAL U.S. THIS WILL LEAD TO HIGH TEMPERATURES RECOVERING FROM IN
THE 30S MONDAY...BACK TO NEAR LATE NOVEMBER NORMALS IN THE 40S BY
WED. THE NEXT SYSTEM MOVING INTO THE WEST WILL SEND ANOTHER ROUND OF
GULF MOISTURE NORTHWARD FOR INCREASING RAIN CHANCES WED NIGHT
THROUGH FRIDAY WITH TEMPERATURES LIKELY TRENDING NEAR TO ABOVE
NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1127 PM CST THU NOV 19 2015
VFR CONDITIONS TO CONTINUE OVERNIGHT WITH WINDS BECOMING LIGHT AND
VARIABLE BY DAYBREAK WITH CLEAR SKIES. A INTENSIFYING STORM SYSTEM
FROM THE NORTHERN ROCKIES WILL BRING INCREASING CLOUDS WITH LOWERING
CEILINGS THROUGH EARLY AFTERNOON AS WINDS SHIFT TO THE NORTHEAST
AT 5 TO 10 KTS. BETWEEN 20/21Z AND 21/03Z...LIGHT TO MODERATE SNOW
WILL DEVELOP WITH CEILINGS DROPPING TO AOB 1K AGL AND VISIBILITIES
AOB 1 MILE FOR IFR TO LIFT CONDITIONS. THESE CONDITIONS WILL EXTEND
PAST 21/06Z AS NORTHEAST WINDS INCREASE TO 10 TO 20 KTS BY MIDNIGHT.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER STORM WARNING FROM 6 PM THIS EVENING TO NOON CST SATURDAY
FOR BENTON-BUCHANAN-CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-
JACKSON-JOHNSON-JONES-KEOKUK-LINN-LOUISA-MUSCATINE-SCOTT-
WASHINGTON.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
SATURDAY FOR DES MOINES-HENRY IA-JEFFERSON-LEE-VAN BUREN.
IL...WINTER STORM WARNING FROM 6 PM THIS EVENING TO NOON CST SATURDAY
FOR BUREAU-CARROLL-HENRY IL-JO DAVIESS-MERCER-PUTNAM-ROCK
ISLAND-STEPHENSON-WHITESIDE.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
SATURDAY FOR HANCOCK-HENDERSON-MCDONOUGH-WARREN.
MO...WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO NOON CST
SATURDAY FOR CLARK-SCOTLAND.
&&
$$
SYNOPSIS...GIBBS
SHORT TERM...GIBBS
LONG TERM...SHEETS
AVIATION...NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1000 AM MST FRI NOV 20 2015
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 203 AM MST FRI NOV 20 2015
LATEST SATELLITE IMAGERY AND RAP H5/H7 ANALYSIS SHOWS SHORTWAVE
TROUGH OVER NORTH CENTRAL WYOMING BEGINNING TO DEEPEN WITH MAIN
MOISTURE AXIS ACROSS NORTHERN NEBRASKA AND SOUTH DAKOTA. AT THE
SURFACE LEE TROUGH IS IN PLACE OVER EASTER COLORADO WITH SOUTHERLY
GRADIENT ACROSS OUR CWA.
TODAY-TONIGHT...SHORTWAVE TROUGH IS ON TRACK TO MOVE THROUGH THE
NORTHERN PLAINS AND DEEPEN WITH A STRONG COLD FRONT DROPPING SOUTH
OVER OUR CWA BY THIS AFTERNOON AND EVENING. MOISTURE PROFILES
CONTINUE TO BE UNIMPRESSIVE...AND THE WINDOW FOR POSITIVE MOISTURE
ADVECTION NARROW. GOOD FORCING AND SPOTTY LIGHT QPF STILL SUPPORT
KEEPING SOME MENTION OF RAIN/SNOW THOUGH CONFIDENCE IS PRETTY LOW WE
WILL SEE MUCH MORE THAN VIRGA OR SPRINKLES/FLURRIES. NAM/ARW/NMM
ACTUALLY SHOW BETTER SIGNAL AFTER 06Z TONIGHT ON BACK SIDE OF UPPER
LOW ASSOCIATED WITH SECONDARY JET STREAK. I KEPT SLIGHT CHANCE POPS
LIMITED TO THE NORTH...TRANSITIONING TO THE WEST DURING THESE
PERIODS WITH SPRINKLES/FLURRIES ELSEWHERE.
WAA ASSOCIATED WITH SOUTHERLY FLOW WILL STILL SUPPORT HIGHS QUICKLY
WARMING AT LEAST IN CLOUD FREE AREAS TO THE 50S BEFORE TEMPERATURES
FALL THIS AFTERNOON BEHIND THE FRONT. LOWS TONIGHT WILL VARY BASED
ON TIMING OF WINDS DECREASING (AND SNOW PACK) AND WITH COLD CANADIAN
AIR MASS IN PLACE LOWS AROUND 10F WILL BE POSSIBLE...AND THE
POTENTIAL FOR SINGLE DIGIT LOW TEMPERATURES EXISTS IN THE WEST.
WHERE WINDS REMAIN HIGHER OVERNIGHT LOWS SHOULD BE CLOSER TO 20F.
AS WAS THE CASE YESTERDAY MODELS SHOW A STRONG PRESSURE GRADIENT
SUPPORTIVE OF AT LEAST NW WINDS GUSTING TO AROUND 40 MPH BASED ON
MIXING HEIGHTS. I STILL CANT RULE OUT SHOWERS MIXING A FEW STRONGER
GUSTS AND IF THIS CORRELATES WITH SNOW COULD REDUCE VISIBILITIES. I
DECIDED NOT TO ADD MENTION OF BLOWING SNOW TO THE GRIDS AND THE
THREAT IS VERY UNCERTAIN/ISOLATED. WILL STILL MAINTAIN MENTION IN
THE HWO.
SATURDAY-SUNDAY NIGHT...ZONAL FLOW AND A DEEP DRY AIR MASS RETURN AND
DRY CONDITIONS WILL PERSIST THROUGH THIS WEEKEND. SHALLOW/COLD AIR
MASS WILL REMAIN IN PLACE THROUGH THE DAY SATURDAY AND HIGHS WILL
GENERALLY BE IN THE 30S (NEAR FREEZING IN PROXIMITY OF SNOW FIELD).
A FEW LOCATIONS IN THE WEST COULD WARM TO AROUND 40 DEPENDING ON
MIXING. WITH INCREASING DOWNSLOPE FLOW/BUILDING LEE TROUGH WAA
INCREASES SUNDAY AND HIGHS IN THE 50S ARE EXPECTED IN AREAS WITHOUT
SNOW PACK. LOWS WILL REFLECT THE GRADUAL WARMING TREND...THOUGH WITH
GOOD RADIATION CONDITIONS/LOWER TD SATURDAY NIGHT WE SHOULD SEE LOWS
IN THE TEENS DESPITE MODERATION ALOFT.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 203 AM MST FRI NOV 20 2015
DRY AND WARM CONDITIONS ARE EXPECTED ON MONDAY AND TUESDAY AS AN
UPPER LEVEL RIDGE FLATTENS OUT ACROSS THE PLAINS AND ZONAL FLOW
DEVELOPS OVER THE REGION. A SHORTWAVE DOES LOOK TO MOVE THROUGH THE
FLOW ON TUESDAY...BUT KEPT THAT PERIOD DRY SINCE LIMITED MOISTURE
SHOULD INHIBIT PRECIP.
QUIET WEATHER PERSISTS FOR THE FORECAST AREA INTO WEDNESDAY AS
RIDGING DEVELOPS AHEAD OF THE NEXT LOW PRESSURE SYSTEM. THIS LOW
TRAVELS FROM THE NORTHWESTERN CONUS TOWARDS THE PLAINS MIDWEEK. A
STRONG COLD FRONT ASSOCIATED WITH THE SYSTEM IS CURRENTLY
ANTICIPATED TO PUSH ACROSS THE HIGH PLAINS WEDNESDAY
NIGHT/THURSDAY...GENERATING RAIN/SNOW CHANCES FOR THE AREA. ONLY
LIGHT ACCUMULATIONS ARE FORECAST AT THIS TIME. LOOKING AHEAD...IT
DOES APPEAR THAT THE REGION WILL SEE BITTER COLD TEMPERATURES JUST
AFTER THE HOLIDAY AS A COLDER AIR MASS PUSHES SOUTH.
TEMPERATURES WILL TREND DOWNWARDS DURING THE EXTENDED PERIOD WITH
HIGHS IN THE 50S ON MONDAY AND TUESDAY COOLING INTO THE UPPER 40S TO
MID 50S FOR WEDNESDAY. THE AREA SHOULD START TO SEE A STEEPER
DECREASE IN TEMPERATURES TOWARDS THE END OF THE WORK WEEK AFTER THE
PASSAGE OF THE COLD FRONT...WITH HIGHS FORECAST IN THE UPPER 30S TO
MID 40S ON THURSDAY. LOWS ARE EXPECTED TO BE IN THE 20S TO LOW 30S
THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1000 AM MST FRI NOV 20 2015
KGLD...VFR CONDITIONS EXPECTED FROM TAF ISSUANCE THROUGH 20Z.
WINDS FROM THE NORTHWEST NEAR 12KTS INITIALLY BUT QUICKEN
INCREASING TO 20KTS GUSTING HIGHER BY 19. AS A COLD FRONT MOVES
THROUGH. FROM 21Z THROUGH 16Z CIGS LOWER TO MVFR RANGE IN POST
FRONTAL MOISTURE. SHOWERS WILL BE AROUND THE TERMINAL INITIALLY AS
RAIN BUT QUICKLY CHANGING TO SNOW LATER THIS AFTERNOON WITH
FLURRIES POSSIBLE EARLY THIS EVENING. WINDS THROUGH 05Z FROM THE
NORTH-NORTHWEST 25G35KTS...FALLING BELOW 12KTS AFTER 06Z. AS THE
SYSTEM EXITS THE AREA AROUND 16Z CIGS QUICKLY IMPROVE TO VFR WITH
WINDS BACKING TO THE WEST JUST UNDER 10KTS.
KMCK...VFR CONDITIONS EXPECTED FROM TAF ISSUANCE THROUGH 19Z WITH
WINDS FROM THE WEST JUST OVER 5KTS. FROM 20Z THROUGH 14Z CIGS
LOWER TO MVFR RANGE. RAIN SHOWERS CHANGING TO SNOW SHOWERS WILL BE
POSSIBLE IN THE 20Z-05Z TIMEFRAME WITH WINDS FROM THE NORTHWEST
GUSTING 25-30KTS. AS THE SYSTEM EXITS THE AREA AROUND 15Z VFR
CONDITIONS RETURN WITH WINDS FROM THE WEST-NORTHWEST 5-10KTS.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JBH
AVIATION...99
AREA FORECAST DISCUSSION
NWS GOODLAND KS
423 AM MST FRI NOV 20 2015
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 203 AM MST FRI NOV 20 2015
LATEST SATELLITE IMAGERY AND RAP H5/H7 ANALYSIS SHOWS SHORTWAVE
TROUGH OVER NORTH CENTRAL WYOMING BEGINNING TO DEEPEN WITH MAIN
MOISTURE AXIS ACROSS NORTHERN NEBRASKA AND SOUTH DAKOTA. AT THE
SURFACE LEE TROUGH IS IN PLACE OVER EASTER COLORADO WITH SOUTHERLY
GRADIENT ACROSS OUR CWA.
TODAY-TONIGHT...SHORTWAVE TROUGH IS ON TRACK TO MOVE THROUGH THE
NORTHERN PLAINS AND DEEPEN WITH A STRONG COLD FRONT DROPPING SOUTH
OVER OUR CWA BY THIS AFTERNOON AND EVENING. MOISTURE PROFILES
CONTINUE TO BE UNIMPRESSIVE...AND THE WINDOW FOR POSITIVE MOISTURE
ADVECTION NARROW. GOOD FORCING AND SPOTTY LIGHT QPF STILL SUPPORT
KEEPING SOME MENTION OF RAIN/SNOW THOUGH CONFIDENCE IS PRETTY LOW WE
WILL SEE MUCH MORE THAN VIRGA OR SPRINKLES/FLURRIES. NAM/ARW/NMM
ACTUALLY SHOW BETTER SIGNAL AFTER 06Z TONIGHT ON BACK SIDE OF UPPER
LOW ASSOCIATED WITH SECONDARY JET STREAK. I KEPT SLIGHT CHANCE POPS
LIMITED TO THE NORTH...TRANSITIONING TO THE WEST DURING THESE
PERIODS WITH SPRINKLES/FLURRIES ELSEWHERE.
WAA ASSOCIATED WITH SOUTHERLY FLOW WILL STILL SUPPORT HIGHS QUICKLY
WARMING AT LEAST IN CLOUD FREE AREAS TO THE 50S BEFORE TEMPERATURES
FALL THIS AFTERNOON BEHIND THE FRONT. LOWS TONIGHT WILL VARY BASED
ON TIMING OF WINDS DECREASING (AND SNOW PACK) AND WITH COLD CANADIAN
AIR MASS IN PLACE LOWS AROUND 10F WILL BE POSSIBLE...AND THE
POTENTIAL FOR SINGLE DIGIT LOW TEMPERATURES EXISTS IN THE WEST.
WHERE WINDS REMAIN HIGHER OVERNIGHT LOWS SHOULD BE CLOSER TO 20F.
AS WAS THE CASE YESTERDAY MODELS SHOW A STRONG PRESSURE GRADIENT
SUPPORTIVE OF AT LEAST NW WINDS GUSTING TO AROUND 40 MPH BASED ON
MIXING HEIGHTS. I STILL CANT RULE OUT SHOWERS MIXING A FEW STRONGER
GUSTS AND IF THIS CORRELATES WITH SNOW COULD REDUCE VISIBILITIES. I
DECIDED NOT TO ADD MENTION OF BLOWING SNOW TO THE GRIDS AND THE
THREAT IS VERY UNCERTAIN/ISOLATED. WILL STILL MAINTAIN MENTION IN
THE HWO.
SATURDAY-SUNDAY NIGHT...ZONAL FLOW AND A DEEP DRY AIR MASS RETURN AND
DRY CONDITIONS WILL PERSIST THROUGH THIS WEEKEND. SHALLOW/COLD AIR
MASS WILL REMAIN IN PLACE THROUGH THE DAY SATURDAY AND HIGHS WILL
GENERALLY BE IN THE 30S (NEAR FREEZING IN PROXIMITY OF SNOW FIELD).
A FEW LOCATIONS IN THE WEST COULD WARM TO AROUND 40 DEPENDING ON
MIXING. WITH INCREASING DOWNSLOPE FLOW/BUILDING LEE TROUGH WAA
INCREASES SUNDAY AND HIGHS IN THE 50S ARE EXPECTED IN AREAS WITHOUT
SNOW PACK. LOWS WILL REFLECT THE GRADUAL WARMING TREND...THOUGH WITH
GOOD RADIATION CONDITIONS/LOWER TD SATURDAY NIGHT WE SHOULD SEE LOWS
IN THE TEENS DESPITE MODERATION ALOFT.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 203 AM MST FRI NOV 20 2015
DRY AND WARM CONDITIONS ARE EXPECTED ON MONDAY AND TUESDAY AS AN
UPPER LEVEL RIDGE FLATTENS OUT ACROSS THE PLAINS AND ZONAL FLOW
DEVELOPS OVER THE REGION. A SHORTWAVE DOES LOOK TO MOVE THROUGH THE
FLOW ON TUESDAY...BUT KEPT THAT PERIOD DRY SINCE LIMITED MOISTURE
SHOULD INHIBIT PRECIP.
QUIET WEATHER PERSISTS FOR THE FORECAST AREA INTO WEDNESDAY AS
RIDGING DEVELOPS AHEAD OF THE NEXT LOW PRESSURE SYSTEM. THIS LOW
TRAVELS FROM THE NORTHWESTERN CONUS TOWARDS THE PLAINS MIDWEEK. A
STRONG COLD FRONT ASSOCIATED WITH THE SYSTEM IS CURRENTLY
ANTICIPATED TO PUSH ACROSS THE HIGH PLAINS WEDNESDAY
NIGHT/THURSDAY...GENERATING RAIN/SNOW CHANCES FOR THE AREA. ONLY
LIGHT ACCUMULATIONS ARE FORECAST AT THIS TIME. LOOKING AHEAD...IT
DOES APPEAR THAT THE REGION WILL SEE BITTER COLD TEMPERATURES JUST
AFTER THE HOLIDAY AS A COLDER AIR MASS PUSHES SOUTH.
TEMPERATURES WILL TREND DOWNWARDS DURING THE EXTENDED PERIOD WITH
HIGHS IN THE 50S ON MONDAY AND TUESDAY COOLING INTO THE UPPER 40S TO
MID 50S FOR WEDNESDAY. THE AREA SHOULD START TO SEE A STEEPER
DECREASE IN TEMPERATURES TOWARDS THE END OF THE WORK WEEK AFTER THE
PASSAGE OF THE COLD FRONT...WITH HIGHS FORECAST IN THE UPPER 30S TO
MID 40S ON THURSDAY. LOWS ARE EXPECTED TO BE IN THE 20S TO LOW 30S
THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 423 AM MST FRI NOV 20 2015
AS COLD FRONT DROPS SOUTH ACROSS THE REGION THIS AFTERNOON CIGS
WILL BEGIN TO LOWER AND WINDS WILL SHIFT TO THE NORTH-NORTHWEST
AND INCREASE. PREVAILING WIND GUSTS 30-35 KFT ARE EXPECTED THIS
AFTERNOON DECREASING DURING THE EVENING HOURS. A FEW STRONGER
GUSTS WILL BE POSSIBLE. MVFR CIGS 2500-3000 KFT ARE SHOWN BY MOST
GUIDANCE BEHIND THIS FRONT IMPROVING LATER TONIGHT. THERE IS SOME
INDICATION OF CIGS DROPPING TO 1500 KFT...HOWEVER CONFIDENCE
WASN`T HIGH ENOUGH TO PREVAIL THIS CONDITION. A FEW RAIN OR SNOW
SHOWERS WILL ALSO BE POSSIBLE. AT THIS TIME VIRGA APPEAR TO BE
MORE LIKELY...AND COVERAGE APPEARS TO BE TOO LOW IN SHOWERS TO
INCLUDE VCSH GROUP DURING THIS UPDATE.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JBH
AVIATION...DR
AREA FORECAST DISCUSSION
National Weather Service Dodge City KS
508 AM CST FRI NOV 20 2015
...Updated Aviation discussion...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 131 AM CST FRI NOV 20 2015
Enjoy the warm day today because conditions change tomorrow. For today,
we will be in the warm sector and there should be some adiabatic compressional
warming ahead of an approaching strong cold front. The ongoing maximum
temperature grid looked on track, although did increase values up a
bit across the northern zones since the fropa and resultant caa has
slowed a bit. Calling for mainly 60s with a few 50s across west-central
Kansas. The front will traverse the region tonight and strong caa is
expected. A strong 850-700-hPa baroclinic zone is expected to pass through.
Models have backed off a bit on flurry potential, but still have some
flurries along and north of Highway 96, where this baroclinic zone
is most pronounced. Winds will increase significantly tonight and through
tomorrow morning (25-30 mph). These windy conditions and cold lows heading
into Saturday morning will create apparent temperature values in the
single digits. Conditions are not cold enough for wind chill advisory
criteria, however.
.LONG TERM...(Saturday THROUGH Thursday)
ISSUED AT 131 AM CST FRI NOV 20 2015
A raw day is expected for Saturday with highs mainly in the 30s. The
northerly winds will decrease in magnitude throughout the day as high
pressure builds in. It will still feel rather blustery and raw through
even with the winds decreasing. The cold conditions will not last long,
as downslope flow is expected Sunday. Highs should jump up back into
the 50s for the end of the weekend. The moderation of temperatures will
continue through the first half of next week as lee troughing and resultant
warm air advection prevails. Conditions may change by Thanksgiving as
a strong upper level disturbance begins to impact the region with low
level frontogenesis across the state. The net result is a chance for
precipitation (probably starting out as showers and may be transition
to snow showers as caa sets in). The superblend pops look fine for now.
Did make slight adjustments to temps as we were warmer than compared
to everyone else. In about a week from now, we might be back on the
cold side again and the ECMWF is showing this cold pattern continuing
outside of the long term domain.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z Saturday MORNING)
ISSUED AT 507 AM CST FRI NOV 20 2015
VFR conditions are expected today given that BUFR soundings
indicated only mid and high level moisture will accompany a weak
upper level disturbance as it crosses the Central High Plains
early today. At the surface a cold front will move south across
southwest Kansas early this afternoon. Behind this front gusty
northwest winds will develop with sustain wind speeds of up to 25
knots possible late today and early tonight. At this time based on
the 06z NAM and latest RAP these gusty winds are expected to reach
GCK between 21z Thursday and 00z Friday. Gusty winds are expected
at HYS around 00z Friday and DDC between 00z and 03z Friday. In
addition to the gusty winds low level moisture will return with
MVFR ceilings becoming possible after sunset, especially in the
HYS area.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 61 24 39 20 / 10 10 0 0
GCK 59 21 37 19 / 10 10 0 0
EHA 64 21 36 21 / 0 10 0 0
LBL 62 23 39 22 / 0 10 0 0
HYS 56 22 37 20 / 10 10 0 0
P28 61 29 42 21 / 10 10 0 0
&&
.DDC Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Sugden
LONG TERM...Sugden
AVIATION...Burgert
AREA FORECAST DISCUSSION
NWS GOODLAND KS
203 AM MST FRI NOV 20 2015
.SHORT TERM...(TODAY THROUGH SUNDAY NIGHT)
ISSUED AT 203 AM MST FRI NOV 20 2015
LATEST SATELLITE IMAGERY AND RAP H5/H7 ANALYSIS SHOWS SHORTWAVE
TROUGH OVER NORTH CENTRAL WYOMING BEGINNING TO DEEPEN WITH MAIN
MOISTURE AXIS ACROSS NORTHERN NEBRASKA AND SOUTH DAKOTA. AT THE
SURFACE LEE TROUGH IS IN PLACE OVER EASTER COLORADO WITH SOUTHERLY
GRADIENT ACROSS OUR CWA.
TODAY-TONIGHT...SHORTWAVE TROUGH IS ON TRACK TO MOVE THROUGH THE
NORTHERN PLAINS AND DEEPEN WITH A STRONG COLD FRONT DROPPING SOUTH
OVER OUR CWA BY THIS AFTERNOON AND EVENING. MOISTURE PROFILES
CONTINUE TO BE UNIMPRESSIVE...AND THE WINDOW FOR POSITIVE MOISTURE
ADVECTION NARROW. GOOD FORCING AND SPOTTY LIGHT QPF STILL SUPPORT
KEEPING SOME MENTION OF RAIN/SNOW THOUGH CONFIDENCE IS PRETTY LOW WE
WILL SEE MUCH MORE THAN VIRGA OR SPRINKLES/FLURRIES. NAM/ARW/NMM
ACTUALLY SHOW BETTER SIGNAL AFTER 06Z TONIGHT ON BACK SIDE OF UPPER
LOW ASSOCIATED WITH SECONDARY JET STREAK. I KEPT SLIGHT CHANCE POPS
LIMITED TO THE NORTH...TRANSITIONING TO THE WEST DURING THESE
PERIODS WITH SPRINKLES/FLURRIES ELSEWHERE.
WAA ASSOCIATED WITH SOUTHERLY FLOW WILL STILL SUPPORT HIGHS QUICKLY
WARMING AT LEAST IN CLOUD FREE AREAS TO THE 50S BEFORE TEMPERATURES
FALL THIS AFTERNOON BEHIND THE FRONT. LOWS TONIGHT WILL VARY BASED
ON TIMING OF WINDS DECREASING (AND SNOW PACK) AND WITH COLD CANADIAN
AIR MASS IN PLACE LOWS AROUND 10F WILL BE POSSIBLE...AND THE
POTENTIAL FOR SINGLE DIGIT LOW TEMPERATURES EXISTS IN THE WEST.
WHERE WINDS REMAIN HIGHER OVERNIGHT LOWS SHOULD BE CLOSER TO 20F.
AS WAS THE CASE YESTERDAY MODELS SHOW A STRONG PRESSURE GRADIENT
SUPPORTIVE OF AT LEAST NW WINDS GUSTING TO AROUND 40 MPH BASED ON
MIXING HEIGHTS. I STILL CANT RULE OUT SHOWERS MIXING A FEW STRONGER
GUSTS AND IF THIS CORRELATES WITH SNOW COULD REDUCE VISIBILITIES. I
DECIDED NOT TO ADD MENTION OF BLOWING SNOW TO THE GRIDS AND THE
THREAT IS VERY UNCERTAIN/ISOLATED. WILL STILL MAINTAIN MENTION IN
THE HWO.
SATURDAY-SUNDAY NIGHT...ZONAL FLOW AND A DEEP DRY AIR MASS RETURN AND
DRY CONDITIONS WILL PERSIST THROUGH THIS WEEKEND. SHALLOW/COLD AIR
MASS WILL REMAIN IN PLACE THROUGH THE DAY SATURDAY AND HIGHS WILL
GENERALLY BE IN THE 30S (NEAR FREEZING IN PROXIMITY OF SNOW FIELD).
A FEW LOCATIONS IN THE WEST COULD WARM TO AROUND 40 DEPENDING ON
MIXING. WITH INCREASING DOWNSLOPE FLOW/BUILDING LEE TROUGH WAA
INCREASES SUNDAY AND HIGHS IN THE 50S ARE EXPECTED IN AREAS WITHOUT
SNOW PACK. LOWS WILL REFLECT THE GRADUAL WARMING TREND...THOUGH WITH
GOOD RADIATION CONDITIONS/LOWER TD SATURDAY NIGHT WE SHOULD SEE LOWS
IN THE TEENS DESPITE MODERATION ALOFT.
.LONG TERM...(MONDAY THROUGH THURSDAY)
ISSUED AT 203 AM MST FRI NOV 20 2015
DRY AND WARM CONDITIONS ARE EXPECTED ON MONDAY AND TUESDAY AS AN
UPPER LEVEL RIDGE FLATTENS OUT ACROSS THE PLAINS AND ZONAL FLOW
DEVELOPS OVER THE REGION. A SHORTWAVE DOES LOOK TO MOVE THROUGH THE
FLOW ON TUESDAY...BUT KEPT THAT PERIOD DRY SINCE LIMITED MOISTURE
SHOULD INHIBIT PRECIP.
QUIET WEATHER PERSISTS FOR THE FORECAST AREA INTO WEDNESDAY AS
RIDGING DEVELOPS AHEAD OF THE NEXT LOW PRESSURE SYSTEM. THIS LOW
TRAVELS FROM THE NORTHWESTERN CONUS TOWARDS THE PLAINS MIDWEEK. A
STRONG COLD FRONT ASSOCIATED WITH THE SYSTEM IS CURRENTLY
ANTICIPATED TO PUSH ACROSS THE HIGH PLAINS WEDNESDAY
NIGHT/THURSDAY...GENERATING RAIN/SNOW CHANCES FOR THE AREA. ONLY
LIGHT ACCUMULATIONS ARE FORECAST AT THIS TIME. LOOKING AHEAD...IT
DOES APPEAR THAT THE REGION WILL SEE BITTER COLD TEMPERATURES JUST
AFTER THE HOLIDAY AS A COLDER AIR MASS PUSHES SOUTH.
TEMPERATURES WILL TREND DOWNWARDS DURING THE EXTENDED PERIOD WITH
HIGHS IN THE 50S ON MONDAY AND TUESDAY COOLING INTO THE UPPER 40S TO
MID 50S FOR WEDNESDAY. THE AREA SHOULD START TO SEE A STEEPER
DECREASE IN TEMPERATURES TOWARDS THE END OF THE WORK WEEK AFTER THE
PASSAGE OF THE COLD FRONT...WITH HIGHS FORECAST IN THE UPPER 30S TO
MID 40S ON THURSDAY. LOWS ARE EXPECTED TO BE IN THE 20S TO LOW 30S
THROUGHOUT THE PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1047 PM MST THU NOV 19 2015
VFR CONDITIONS WILL PERSIST AT GLD AND MCK THROUGH TONIGHT AND
THROUGH MUCH OF THE DAY TOMORROW. CLOUD COVER IS EXPECTED TO
INCREASE WITH CEILINGS LOWERING AFTER 18Z. WITH THE FRONTAL
PASSAGE EXPECTED BY 20Z TOMORROW AT BOTH LOCATIONS...LIGHT SOUTH
WINDS WILL TURN SOUTHWEST AND THEN BECOME GUSTY OUT OF THE
NORTHWEST BY 21Z. SUSTAINED WINDS SPEEDS OF 20-25KTS WILL BE
COMMON WITH GUSTS TO 30-35 KTS BETWEEN 21Z AND 04Z.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...JBH
AVIATION...LOCKHART
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
955 AM CST FRI NOV 20 2015
.UPDATE...
MAIN ADJUSTMENT TO THE PREVIOUS FORECAST WAS TO INCREASE WINDS IN
THE COASTAL WATERS AND NEAR THE COAST. OFFSHORE WINDS HAVE BEEN
RUNNING 15 TO 20 KTS AND SOUTH OF THE I10 CORRIDOR 10 TO 15 KTS
WITH LATEST HRRR AND RUC GUIDANCE INDICATING THAT THESE WIND
SPEEDS WILL PERSIST THROUGH THE AFTERNOON. REST OF THE FORECAST
REMAINS ON TRACK WITH HIGH TEMPERATURES IN THE LOW TO MID 70S.
&&
.PREV DISCUSSION...
DISCUSSION...
20/12Z TAF ISSUANCE.
AVIATION...
HIGH PRES RIDGING SOUTH ACRS LA IS KEEPING A DRY AIRMASS IN
PLACE...WITH NELY WINDS AROUND 5 KT. SKC EXPECTED TO PREVAIL
TODAY AS THE HIGH MOVES EAST...ALLOWING WINDS TO BECOME MORE
ESELY THIS AFTN. MOISTURE WILL BEGIN TO INCREASE TONIGHT...WITH A
BKN/OVC MID-LVL DECK DEVELOPING AS A COLD FRONT MOVES INTO THE
AREA. A FEW SHRA WILL BE POSSIBLE LATE TONIGHT...MAINLY NEAR BPT.
24
PREV DISCUSSION...
.FIRST FREEZE/FROST OF THE SEASON POSSIBLE SUNDAY NIGHT/MONDAY
MORNING...
DISCUSSION...
SURFACE HIGH PRESSURE CENTERED OVER THE MID MISSISSIPPI VALLEY IS
RIDGING DOWN INTO THE FORECAST AREA THIS EARLY MORNING. AGAIN
PROVIDING FAIR CONDITIONS...WITH TEMPERATURES NEAR THE DAILY
OVERNIGHT LOW NORMALS.
WATER VAPOR IMAGERY SHOWS A LARGE UPPER LEVEL LOW OVER EASTERN
CANADA...NORTH OF THE GREAT LAKES. A SHORT WAVE WAS ROTATING
AROUND THIS FEATURE MOVING DOWN INTO THE MOUNTAIN WEST.
THE SHORT WAVE WILL CONTINUE TO DIG DOWN TO THE SOUTHEAST TODAY
HELPING TO CARVE OUT AN UPPER LEVEL TROUGH OVER THE EASTERN U.S.
THIS WEEKEND...WITH UPPER LEVEL RIDGING NOTED OVER THE WESTERN
U.S. THE RESULT WILL BE A DEEPENING NORTHWEST FLOW ALOFT...THAT
WILL PUSH A STRONG CANADIAN COLD FRONT DOWN THROUGH THE REGION.
THE COLD FRONT LOOKS TO ARRIVE IN THE FORECAST AREA LATE SATURDAY
MORNING...AND ACROSS THE FORECAST AREA DURING THE AFTERNOON HOURS.
BEFORE THE FRONT ARRIVES...MID MISSISSIPPI SURFACE RIDGE WILL MOVE
OFF TO THE EAST TO THE MID ATLANTIC STATES...WITH A SURFACE LOW
DEVELOPING OVER THE CENTRAL PLAINS...EAST OF THE ROCKIES. THIS
WILL ALLOW FOR A BRIEF PERIOD OF SOUTHEAST WINDS AND RETURN FLOW
MOISTURE OFF THE GULF TO OCCUR.
MOISTURE PROFILES FROM THE 20/00Z GFS ARE CONSISTENT WITH PAST
RUNS...WITH A RELATIVELY DRIER SOLUTION (PWAT BETWEEN 1.10-1.25
INCHES...WHICH IS SLIGHTLY ABOVE NOVEMBER NORM...AND MEAN RH
60-70 PERCENT)...WHILE THE 20/00Z ECMWF IS ALSO NOW CLOSER TO THE
GFS WITH ITS MOISTURE PROFILE AHEAD OF THE FRONT...JUST A LITTLE
MORE MOIST (PWAT 1.30-1.40 INCH RANGE AND MEAN RH OVER 70
PERCENT.) THIS SEEMS REASONABLE...AS GULF AIR MASS WILL STILL BE
MODIFIED AND NO REAL GOOD LOW LEVEL JET TO BRING IN DEEPER GULF
MOISTURE LOCATED FURTHER TO THE SOUTH.SO THERE IS BETTER CONFIDENCE
WITH POP NUMBERS.
SCATTERED SHOWERS WILL FORM AHEAD OF THE FRONT LATE FRIDAY NIGHT
AND GRADUALLY TAPER OFF FROM NORTH TO SOUTH DURING SATURDAY
AFTERNOON. LOW END POPS TO THE NORTH AND HIGH END POPS TO THE
SOUTH LOOK GOOD. RAINFALL SHOULD MAINLY BE ON THE LIGHT SIDE WITH
MAYBE A FEW MODERATE CELLS. THE GUIDANCE IS ALSO IN BETTER
AGREEMENT WITH THE INSTABILITY DURING THIS EVENT...WITH DECENT
CAPE AND LI`S STAYING OVER THE COASTAL WATERS. THEREFORE...THE
ACTIVITY FOR LAND AREAS WILL LIKELY JUST BE RAIN SHOWERS. AREA
WIDE AVERAGE QPF DURING THE FRONTAL PASSAGE LOOK TO BE LESS THAN A
QUARTER OF INCH NORTH OF I-10...AND JUST ABOVE A QUARTER OF AN
INCH ALONG THE I-10 CORRIDOR TO THE COAST.
WITH THE DEEP NORTHWEST FLOW BEHIND THE COLD FRONT...AIR MASS WILL
BE ORIGINATING FROM CANADA...A MUCH COOLER AND DRIER CONTINENTAL
AIR MASS WILL OVER TAKE THE FORECAST AREA LATE SATURDAY AND HANG
AROUND INTO EARLY NEXT WEEK. PROGS SHOW THE DRYNESS OF THE AIR
MASS WITH PWATS BY SUNDAY UNDER A QUARTER OF AN INCH AND MEAN RH
UNDER 20 PERCENT. AIR TEMPERATURES WILL BE SOME 15F DEGREES BELOW
THE DAILY NORMS.
THE COLDEST TEMPERATURES LOOK TO OCCUR ON SUNDAY NIGHT INTO MONDAY
MORNING WITH THE SURFACE HIGH SETTLING IN OVER THE FORECAST AREA.
THE LIGHT WINDS AND CLEAR SKIES SHOULD MAKE FOR GOOD RADIATIONAL
COOLING. THE LATEST OPERATION GFS MOS NUMBERS STILL ON THE LOW END
OF THE ENSEMBLE BY A FEW DEGREES. THE LOWS THAT WERE FORECAST BY
THE DAY SHIFT FOR MONDAY MORNING ARE VERY CLOSE TO BOTH THE LATEST
GFS MEAN AND THE ECMWF 50P AND 90P VALUES. THEREFORE...THOSE
NUMBERS LOOK REASONABLE TO GO WITH AGAIN. THIS MEANS THE FIRST
FREEZE/FROST OF THE SEASON LOOKS LIKE A GOOD BET FOR A PORTION OF
THE FORECAST AREA. A LIGHT FREEZE SEEMS REASONABLE FOR MOST OF
UPPER SOUTHEAST TEXAS AND CENTRAL LOUISIANA...WITH A FROST
POSSIBLE DOWN TO THE I-10 CORRIDOR DURING LATE SUNDAY NIGHT INTO
EARLY MONDAY MORNING.
THE COLD HIGH PRESSURE SYSTEM WILL MOVE OFF TO THE EAST ON
TUESDAY...WITH A MORE SOUTHEAST FLOW DEVELOPING...THAT WILL HELP
MODERATE TEMPERATURES AND START A WARMING TREND...WITH
TEMPERATURES THEN ABOVE DAILY NORMS AS MID-WEEK TO THE
THANKSGIVING HOLIDAY ROLLS AROUND. MOISTURE WILL ALSO
INCREASE...AND WITH THE FORECAST AREA BETWEEN AN UPPER LEVEL
TROUGH OVER THE WEST AND SOUTHWEST U.S. AND UPPER LEVEL RIDGING
FROM THE SOUTHERN GULF ACROSS THE SOUTHEAST U.S. THERE WILL BE A
CHANCE OF SHOWERS STARTING ON WEDNESDAY THROUGH THE END OF THE
FORECAST PERIOD.
RUA
MARINE...
WEAK SURFACE HIGH CENTERED OVER THE MID MISSISSIPPI VALLEY IS
RIDGING DOWN INTO THE COASTAL WATERS AND HELPING TO PRODUCE
MODERATE NORTHEAST WINDS...JUST UNDER EXERCISE CAUTION CRITERIA.
THESE WINDS WILL BECOME MORE EASTERLY TODAY...AND THEN BRIEFLY
SOUTHEAST TONIGHT AS THE HIGH MOVES OFF TO THE EAST AND A COLD
FRONT APPROACHES FROM THE NORTH.
THIS FRONT WILL BRING DOWN A RATHER CHILLY CANADIAN AIR MASS. THE
COLD AIR ADVECTION GOING OVER RELATIVELY WARMER WATER...GULF OF
MEXICO SEA TEMPERATURES IN THE LOW TO MID 70S...SHOULD CREATE
DECENT MIXING TO BRING DOWN STRONG WINDS TO THE SURFACE. SMALL
CRAFT ADVISORY CONDITIONS LOOK LIKELY FROM LATE SATURDAY INTO
SUNDAY...WITH THE POSSIBILITY OF FREQUENT GUSTS TO GALE FORCE OVER
THE OUTER WATERS SATURDAY NIGHT INTO EARLY SUNDAY.
THE STRONG NORTHERLY FLOW COULD ALSO PRODUCE LOW WATER CONDITIONS
DURING THE PREDICTED LOW TIDE TIMES FROM LATE SATURDAY INTO
SUNDAY.
WINDS WILL BEGIN TO DECREASE ON MONDAY AS THE HIGH SETTLES OVER
THE REGION...AND LIGHT ONSHORE FLOW STARTING ON TUESDAY AS THE
HIGH MOVES OFF TO THE EAST. THE EAST TO SOUTHEAST WINDS WILL
INCREASE BY MID WEEK AS THE NEXT LOW PRESSURE SYSTEM BEGINS TO
DEVELOP OVER THE ROCKIES.
RUA
&&
.PRELIMINARY POINT TEMPS/POPS...
AEX 71 52 65 38 / 0 20 30 10
LCH 73 56 68 43 / 0 30 50 10
LFT 73 57 69 42 / 0 30 40 10
BPT 76 59 68 43 / 0 30 50 10
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...NONE.
&&
$$
PUBLIC...26
AREA FORECAST DISCUSSION
NWS CARIBOU ME
917 AM EST FRI NOV 20 2015
.SYNOPSIS...
AN OCCLUDED FRONT WILL CROSS THE REGION TODAY THROUGH EARLY
TONIGHT WITH RAIN IN ADVANCE OF THE FRONT...THEN EXIT ACROSS THE
MARITIMES LATER TONIGHT. HIGH PRESSURE WILL BUILD ACROSS THE
REGION SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...LATEST RADAR REFLECTIVITY IMAGERY SHOWS AN AREA OF RAIN
ENCOMPASSING MUCH OF NORTHERN AND DOWN EAST MAINE AS OF LATE THIS
MORNING. THERE IS A RATHER SHARP BACK EDGE TO THE RAIN EVIDENT ON
RADAR AS WELL. THE LATEST HRRR SHOWS THE BACK EDGE OF THE RAIN WILL
CONTINUE TO PROGRESS FORM WEST TO EAST DURING THE COURSE OF TODAY.
THE RAIN WILL LINGER THE LONGEST ACROSS THE EASTERN MAINE/NEW
BRUNSWICK BORDER WHERE THE RAIN WILL LIKELY CONTINUE INTO THIS
EVENING. NO SIGNIFICANT CHANGES TO CURRENT FORECAST.
PREVIOUS DISCUSSION...
RAIN WILL OCCUR ACROSS THE REGION TODAY IN ADVANCE OF AN OCCLUDED
FRONT MOVING EAST ACROSS THE FORECAST AREA. A STRONG LOW LEVEL JET
WILL ALSO CROSS THE REGION ON ADVANCE OF THE FRONT PRODUCING GUSTY
WINDS. THE STRONGEST WINDS ARE EXPECTED ALONG THE DOWNEAST COAST
WHERE ONSHORE WINDS COULD GUST TO AROUND 40 MPH AT TIMES. THE
FRONT WILL EXIT ACROSS NEW BRUNSWICK EARLY TONIGHT. RAIN WILL
TAPER TO SHOWERS IN THE WAKE OF THE FRONT EARLY TONIGHT BEFORE
ENDING. COLDER AIR IN THE WAKE OF THE FRONT COULD ALLOW RAIN
SHOWERS TO MIX WITH...OR CHANGE TO...SNOW SHOWERS ACROSS NORTHERN
MAINE EARLY TONIGHT WITH ANY SNOW ACCUMULATION LESS THAN AN INCH.
HIGH PRESSURE WILL THEN BUILD ACROSS THE REGION LATER TONIGHT WITH
DECREASING CLOUDS. HIGH TEMPERATURES TODAY WILL RANGE FROM THE MID
TO UPPER 40S NORTH...TO THE LOWER 50S DOWNEAST. LOW TEMPERATURES
TONIGHT WILL RANGE FROM THE MID TO UPPER 20S NORTH...TO AROUND 30
TO THE LOWER 30S DOWNEAST.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
HIGH PRESSURE WILL BUILD OVER THE REGION SATURDAY THEN MOVE TO
THE EAST SATURDAY NIGHT AS INTENSE LOW PRESSURE MOVES NORTHEAST
ACROSS QUEBEC PROVINCE. A COLD FRONT IS THEN EXPECTED TO MOVE
ACROSS THE STATE SUNDAY BEHIND THE LOW PRESSURE SYSTEM TO THE
NORTH. SHOWERS AND SNOW SHOWERS ARE EXPECTED EARLY SUNDAY IN THE
WEST AS THE FRONT APPROACHES THEN SHOWERS ARE EXPECTED LATER IN
THE DAY SUNDAY OVER THE REMAINDER OF THE REGION AS THE FRONT MOVES
THROUGH.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
A COLDER AIR MASS WILL MOVE IN BEHIND THE FRONT SUNDAY NIGHT
ALONG WITH HIGH PRESSURE. A LOW PRESSURE SYSTEM IS ALSO EXPECTED
TO DEVELOP OFF THE EAST COAST SOUTH OF NEW ENGLAND SUNDAY NIGHT.
THIS SYSTEM WILL THEN MOVE NORTHWARD OVER THE OCEAN AND ACROSS
NOVA SCOTIA MONDAY AND MONDAY NIGHT. A STRONG HIGH PRESSURE SYSTEM
IS THEN EXPECTED TO BUILD ACROSS THE NORTHEAST TUESDAY AND
WEDNESDAY THEN MOVE TO THE EAST THURSDAY.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: IFR/LIFR CONDITIONS ARE EXPECTED ACROSS THE REGION
TODAY ALONG WITH GUSTY WINDS. MVFR/IFR CONDITIONS ARE EXPECTED
ACROSS THE REGION EARLY TONIGHT...THEN IMPROVING TO VFR LEVELS
OVERNIGHT.
SHORT TERM: EXPECT VFR CONDITIONS SATURDAY. MVFR CONDITIONS ARE
POSSIBLE SUNDAY AS A FRONTAL SYSTEM MOVES THROUGH AND STALLS EAST
OF THE AREA SUNDAY NIGHT. VFR CONDITIONS ARE EXPECTED MONDAY AND
TUESDAY.
&&
.MARINE...
NEAR TERM: A GALE WARNING REMAINS IN EFFECT FOR THE WATERS THROUGH
THIS AFTERNOON. SMALL CRAFT ADVISORY CONDITIONS ARE THEN EXPECTED
TONIGHT. VISIBILITIES WILL BE REDUCED IN RAIN AND FOG TODAY INTO
THIS EVENING.
SHORT TERM: HAVE USED A 50/50 BLEND OF THE NAM12 AND GFS40 FOR
SUSTAINED WINDS SATURDAY INTO SUNDAY THEN TRANSITION TO THE SUPER
BLEND WINDS. FOR WAVES: LONG PERIOD SOUTHEASTERLY WAVES FROM
PREVIOUS DAYS FETCH ARE EXPECTED TO SUBSIDE TO BELOW 2 FEET BY
SATURDAY MORNING. EXPECT PRIMARY WAVE SYSTEM SATURDAY TO BE
NORTHEASTERLY WIND WAVES. A NEW SOUTHEASTERLY FETCH IS THEN
EXPECTED TO DEVELOP OFF-SHORE AHEAD OF A DEVELOPING OCEAN LOW
SATURDAY NIGHT INTO SUNDAY. THIS WILL RESULT IN WAVE HEIGHTS
BUILDING TO AROUND 5 FEET/8 SECONDS ON SUNDAY. THIS WAVE SYSTEM
WILL ALSO PREDOMINATE ON MONDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...GALE WARNING UNTIL 5 PM EST THIS AFTERNOON FOR ANZ050>052.
&&
$$
NEAR TERM...DUDA/NORCROSS
SHORT TERM...MIGNONE
LONG TERM...MIGNONE
AVIATION...DUDA/NORCROSS/MIGNONE
MARINE...DUDA/NORCROSS/MIGNONE
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1231 PM EST FRI NOV 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM EST FRI NOV 20 2015
AN UPPER TROUGH OVER ONTARIO IS LEADING TO THE COLDEST AIR THAT WE
HAVE SEEN THIS FALL...WITH 850MB TEMPS -12C AT KINL AT 00Z AND THAT
MATCHES THE RAP ANALYSIS OVER WESTERN LAKE SUPERIOR. A SECONDARY
TROUGH ASSOCIATED WITH THE STRONG LOW OVER HUDSON BAY IS SLOWLY
MOVING EAST ACROSS CENTRAL LAKE SUPERIOR AT THIS TIME AND HAS
SHIFTED WINDS MORE TO THE WEST OVER WESTERN LAKE SUPERIOR. THE COLD
TEMPS HAVE LED TO LAKE EFFECT SNOW IN THE WESTERLY WIND SNOW BELTS.
LOOKING AT WEBCAMS...IT IS TOUGH TO GET A HANDLE ON THE AMOUNT OF
SNOW THAT HAS FALLEN DUE TO THE STRONG WINDS...BUT IT LOOKS TO HAVE
PRODUCED A FEW INCHES IN THE HOUGHTON/CALUMET AREA. THE WINDS HAVE
HELPED CONTRIBUTE TO VISIBILITIES FALLING TO OR BELOW A MILE AT
TIMES AS THEY CONTINUE TO GUST TO 35-40KTS IN THE KEWEENAW.
EXPECT THE LAKE EFFECT TO CONTINUE THROUGH THE SHORT TERM
PERIOD...BUT THE INTENSITY SHOULD BE ON THE DECREASE DUE TO SEVERAL
FACTORS. FIRST...THE DEEP MOISTURE DIMINISHES AS AN UPPER RIDGE
MOVES OVER THE AREA TODAY AHEAD OF A SECONDARY TROUGH MOVING THROUGH
THE NORTHERN ROCKIES. SUBSIDENCE ALOFT WITH THAT RIDGING WILL HELP
LOWER INVERSION HEIGHTS THROUGH THE DAY TOWARDS 7-8KFT (FROM THE
PRESENT 10KFT). SECOND...THE INCREASED CONVERGENCE SEEN ALONG AND
JUST BEHIND THE SURFACE TROUGH WILL DIMINISH THROUGH THE MORNING
HOURS AS THE WINDS BECOME FAIRLY UNIFORM AROUND 270-280 DEGREES.
THERE IS A SECONDARY TROUGH THAT WILL MOVE THROUGH LATE THIS
AFTERNOON AND EARLY THIS EVENING...AND SHIFT WINDS AROUND TO MORE
290-300 DEGREES. THAT WILL BRING MORE LOCATIONS IN THE WESTERN AND
EASTERN U.P. UNDER SOME LAKE EFFECT SNOW (TRADITIONAL NW WIND SNOW
BELTS). ONE OTHER LIMITING FACTOR WILL BE THE CONTINUED INDICATION
BY THE MODELS OF AN INVERTED-V LOOK TO THE LOW LEVELS. THAT BEING
SAID...THE WEAKENING WINDS WILL INCREASE RESIDENCE TIME AND LEAD TO
LESS FRACTURING OF THE FLAKES FOR TONIGHT...SO WOULDN/T BE SURPRISED
TO SEE A FEW LOCATIONS PICKING UP ONE TO LOCALLY TWO INCHES AS MUCH
OF THE CLOUD WILL BE WITHIN THE DGZ. FOR TODAY...EXPECT DAYTIME
ACCUMULATIONS OF 1-2 INCHES OVER THE KEWEENAW AND MAYBE A TOUCH MORE
OVER FAR NORTHEAST LUCE COUNTY WHERE THE LONGER FETCH WILL CREATE
STRONGER BANDS THAT WILL SHIFT SOUTH ALONG THE LUCE COUNTY SHORELINE
IN THE AFTERNOON. AT THIS POINT...THE 15Z END TIME TO THE WINTER WX
ADVISORY LOOKS PRETTY GOOD AS THAT MATCHES UP WELL WITH THE
DIMINISHING TREND IN BOTH THE WINDS AND DEEPER MOISTURE.
WHILE WINDS ARE STILL GUSTING TO 40KTS OVER PORTIONS OF LAKE
SUPERIOR AND THE KEWEENAW PENINSULA AS OF 3AM...THE WEAKENING
PRESSURE GRADIENT THROUGH THE DAY WILL LEAD TO STEADILY DIMINISHING
WINDS THROUGH THE DAY AND EXPECT THEM TO FALL BELOW GALES OVER LAKE
SUPERIOR BY EARLY EVENING. THAT DIMINISHING WILL CONTINUE THROUGH
THE NIGHT AS THEY SHIFT TO THE NORTHWEST. FINALLY...HIGHS TODAY WILL
RANGE FROM THE UPPER 20S OVER THE WEST TO THE LOWER 30S OVER THE
EAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 525 AM EST FRI NOV 20 2015
AFTER WARM WEATHER SO FAR THIS NOV ACROSS THE UPPER LAKES (AT NWS
MARQUETTE, IT`S BEEN THE WARMEST FIRST 19 DAYS OF NOV ON RECORD)...
SEASONABLY COLD WEATHER WILL BE THE RULE THRU THIS WEEKEND AS A TROF
DOMINATES THE GREAT LAKES REGION. NEXT WEEK...A BUILDING
RIDGE/POSITIVE HEIGHT ANOMALY IN THE GULF OF ALASKA INTO WRN CANADA
WILL FORCE TROFFING INTO THE WRN CONUS...THOUGH THE FLOW WILL BE
SPLIT AND TROF WILL BE POSITIVE TILT. THIS IN TURN WILL FORCE
DOWNSTREAM HEIGHT RISES FROM THE ERN PLAINS TO THE E COAST...
RESULTING IN WARMING FOR THE UPPER LAKES TUE/WED AND PERHAPS THRU
THANKSGIVING DAY. THE BIG UNCERTAINTY THAT MAY IMPACT HOLIDAY TRAVEL
IS HOW QUICKLY THE NRN PORTION OF THE WRN TROF PROGRESSES EASTWARD.
WITH THE SRN STREAM PORTION OF THE TROF STILL HANGING BACK OVER THE
SW STATES/SRN ROCKIES...IT MAY SEND ENERGY NE ALONG THE COLD FRONT
MARKING THE LEADING EDGE OF ARCTIC AIR BEING DRIVEN SE BY THE
POSITIVE HEIGHT ANOMALY IN WRN CANADA...RESULTING IN A BAND OF
WINTRY PCPN SOMEWHERE OVER THE UPPER MISSISSIPPI VALLEY OR WRN GREAT
LAKES LATE WEEK. SEASONABLY COLD WEATHER WILL FOLLOW INTO NEXT
WEEKEND...BUT TONIGHTS 00Z GFS/ECMWF ARE QUICKER PUSHING THE WRN
CANADA POSITIVE HEIGHT ANOMALY EASTWARD...WHICH CUTS OFF THE ARCTIC
AIR BEFORE IT REACHES THE UPPER LAKES. FARTHER OUT...CANADIAN
ENSEMBLES AND THE CFSV2 16 MEMBER ENSEMBLE MEAN FAVOR A RETURN TO
PACIFIC FLOW ACROSS THE NRN CONUS/SRN CANADA. SO...AT THIS
POINT...IT APPEARS AN ABOVE NORMAL TEMP REGIME WILL PROBABALY LOCK
IN AGAIN AFTER THE FIRST FEW DAYS OF DEC. AS FOR PCPN...ONGOING LES
WILL PICK UP SOME SAT AS ENERGY SWINGS SE INTO CNTRL PLAINS THEN NE
INTO THE ERN GREAT LAKES. SYSTEM WILL TRACK FAR ENOUGH S AND SE OF
HERE THAT THE SYNOPTIC SNOW SHIELD SHOULD PASS MOSTLY SE OF THE FCST
AREA. A CLIPPER TYPE SHORTWAVE WILL BRING SOME -SN SUN NIGHT/MON
WITH LAKE ENHANCEMENT OFF LAKE MI POSSIBLE INTO THE FAR ERN FCST
AREA. AFTER A TREND TO DRY WEATHER ON TUE...PCPN WILL RETURN
POSSIBLY AS EARLY AS WED AND CONTINUE INTO FRI.
BEGINNING SAT...SHORTWAVE SWINGING THRU THE PLAINS FRI NIGHT WILL
BEGIN TO SPIN UP A SFC WAVE THAT SHOULD BE IN THE VCNTY OF WRN IL AT
12Z SAT. AS THE SHORTWAVE LIFTS TOWARD THE ERN GREAT LAKES...THE LOW
WILL DEEPEN AND TRACK TO THE VCNTY OF DETROIT BY SAT EVENING. THE
REGIONAL CANADIAN AND NCEP ARW/NMM ARE THE DEEPEST/FARTHEST W
SOLUTIONS AND ARE NEARLY IDENTICAL WITH A TRACK TO NEAR SAGINAW BAY.
THE GFS IS A LITTLE FARTHER SE AND THE NAM/ECMWF ARE
WEAKEST/FARTHEST SE WITH A TRACK TO FAR WRN LAKE ERIE. THE CANADIAN
HAS TRENDED NW/STRONGER SINCE THE 12Z RUN...BUT IT IS WITHIN THE
ENVELOP OF THE LAST 5 SOLUTIONS. THE GFS HAS BEEN VERY CONSISTENT IN
THE LAST 5 RUNS. SINCE THE RELATIVELY WARM WATERS OF THE GREAT LAKES
OFTEN CAN HELP PULL DEVELOPING LOW PRES SYSTEMS TO THE W...
ESPECIALLY EARLY IN THE COLD SEASON...FCST WILL LEAN TOWARD THE
FARTHEST W SOLUTIONS OF THE REGIONAL GEM AND NCEP ARW/NMM. THESE
SOLUTIONS RESULT IN LOW-LEVEL FLOW BACKING MORE AND BECOMING MORE
CYCLONIC ACROSS UPPER MI/LAKE SUPERIOR WITH A PERIOD OF NW TO N FLOW
INCREASING LES COVERAGE OVER NRN UPPER MI. RESULT COULD BE THE
POTENTIAL FOR MDT SNOW ACCUMULATIONS OVER MUCH OF THE NCNTRL AND WRN
FCST AREA. THE NE FRINGE OF THE SYNOPTIC SNOW WOULD ALSO BRUSH THE
SE FCST AREA. WITH FCST SOUNDINGS SHOWING DEEPENING MOISTURE AND
FAIRLY HIGH SNOW TO WATER RATIOS...MAY SEE ADVY TYPE SNOWFALL FOR
THE NW TO N WIND FAVORED SNOWBELTS WITH THE MAIN TIME FRAME FOR THE
HEAVIER SNOW ROUGHLY IN THE 18Z SAT TO 06Z SUN TIME PERIOD. OFFICIAL
FCST WILL SHOW 12HR SNOW AMOUNTS OF 2-4 INCHES WHICH IS JUST UNDER
ADVY THRESHOLD FOR LES/HIGH SNOW TO WATER RATIO SNOW. NRN FRINGE OF
SYNOPTIC SNOW SHOULD ONLY YIELD AN INCH OR LESS ACROSS THE SCNTRL/SE
FCST AREA.
BACKING WINDS/DRYING AIR MASS AS HIGH PRES RIDGE ARRIVES SUN WILL
DIMINISH LINGERING LES. IN FACT...EXPECT ALL LES TO END BY LATE
AFTN AS WINDS BACK.
SUN NIGHT/MON...ATTENTION TURNS TO A CLIPPER TYPE SHORTWAVE THAT
REACHES THE UPPER GREAT LAKES MON MORNING. WAA/ISENTROPIC ASCENT
SHOULD YIELD SOME -SN SPREADING ACROSS THE AREA SUN NIGHT WITH
ACCUMULATIONS PROBABLY UNDER 1 INCH. OF MORE CONCERN IS THE BACKING
WINDS WHICH MAY BACK ENOUGH TO LEAD TO LAKE ENHANCEMENT OFF LAKE
MICHIGAN INTO THE FAR ERN FCST AREA SUN NIGHT. FOR NOW...INCREASED
POPS GENERALLY ALONG E OF KISQ/KERY LINE WITH A COUPLE OF INCHES OF
SNOW POSSIBLE.
SOME LIGHT WNW FLOW LES WILL BE POSSIBLE BEHIND THE SHORTWAVE INTO
MON NIGHT. DRY WEATHER WILL RETURN TUE UNDER WAA/BACKING WINDS.
AS ALLUDED TO ABOVE...THE BIG UNCERTAINTY LATER NEXT WEEK WILL BE
HOW QUICKLY THE NRN PORTION OF THE WRN TROF PROGRESSES EASTWARD.
WITH THE SRN STREAM PORTION OF THE TROF HANGING BACK OVER THE SW
STATES/SRN ROCKIES...THERE WILL BE THE POTENTIAL FOR A DECENT PCPN
EVENT ALONG THE COLD FRONT MOVING INTO THE GREAT LAKES. AT THIS
POINT...RECENT GFS/ECMWF RUNS SUGGEST RAIN DEVELOPING LATE WED INTO
THANKSGIVING DAY WITH A TRANSITION TO SNOW FROM NW TO SE
THANKSGIVING NIGHT/FRI. IT REMAINS TO BE SEEN WHETHER THIS WILL
DEVELOP INTO A SIGNIFICANT PCPN EVENT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1230 PM EST FRI NOV 20 2015
ONGOING BREEZY WEST WINDS WILL CONTINUE TO SLOWLY DIMINISH THROUGH
THE TAF PERIOD. SKIES ARE CLEARING AT IWD...AND A BROKEN LOW-END
MVFR STRATO-CU DECK REMAINS AT KSAW. THIS SHOULD LAST THROUGH THE
AFTERNOON BEFORE SLIGHTLY VEERING WINDS BRING HIGH-END MVFR CIGS TO
BOTH SITES. LAKE EFFECT SNOW SHOWERS SHOULD GRADUALLY MOVE INTO KIWD
OVERNIGHT...AND KSAW LATE SAT MORNING.
AT KCMX...A PAIR OF LES BANDS CONTINUE TO STRADDLE THE AIRPORT.
VEERING WINDS THIS AFTERNOON SHOULD PUSH THE NORTHERN BAND ACROSS
THE SITE...LEADING TO TEMPORARY IFR VIS. FROM THIS EVENING INTO
SAT...SCATTERED LES IS EXPECTED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 322 AM EST FRI NOV 20 2015
A TROUGH ASSOCIATED WITH A STRONG LOW PRESSURE SYSTEM OVER HUDSON
BAY WILL CROSS LAKE SUPERIOR THIS EVENING. OVER-WATER INSTABILITY
COMBINED WITH A STRONG PRESSURE GRADIENT WILL RESULT IN WSW STORM
FORCE WINDS TO 50 KNOTS FOR MUCH OF THE OPEN WATERS OF WEST AND
CENTRAL LAKE SUPERIOR THIS EVENING. ONCE THE TROUGH COMPLETELY
CROSSES THE LAKE OVERNIGHT...WINDS WILL SHIFT TO THE WEST AND GUST
TO GALES TO 35-40 KTS THROUGH MUCH OF FRIDAY. THESE STRONG WINDS
WILL DIMINISH STEADILY TO UNDER 25 KTS ON FRI NIGHT/SAT WITH THE
APPROACH OF A WEAK HI PRESSURE RIDGE. A STRONGER N TO NW FLOW UP TO
30 KTS IS POSSIBLE ON SAT NIGHT DEPENDING ON THE TRACK OF A LO PRES
MOVING NE THRU SE ONTARIO. THE FLOW WILL THEN SHIFT TO THE SW UP TO
25 KTS BY LATE SUN INTO MON AS A TRAILING HI PRES RIDGE CROSSES THE
UPPER LAKES AND AHEAD OF ANOTHER LO PRES TROUGH APPROACHING FROM THE
NW. FOLLOWING THE TROF PASSAGE...EXPECT W TO NW WINDS UP TO 25 KTS
ON MON INTO TUE...BUT THEN WINDS WILL SHIFT BACK TO THE SW BY
LATER ON TUE AFTER TRAILING HI PRES SHIFTS TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ250-251-264>267.
GALE WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR LSZ162-
246-247.
GALE WARNING UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR
LSZ241>245-263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...TK
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
637 AM EST FRI NOV 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM EST FRI NOV 20 2015
AN UPPER TROUGH OVER ONTARIO IS LEADING TO THE COLDEST AIR THAT WE
HAVE SEEN THIS FALL...WITH 850MB TEMPS -12C AT KINL AT 00Z AND THAT
MATCHES THE RAP ANALYSIS OVER WESTERN LAKE SUPERIOR. A SECONDARY
TROUGH ASSOCIATED WITH THE STRONG LOW OVER HUDSON BAY IS SLOWLY
MOVING EAST ACROSS CENTRAL LAKE SUPERIOR AT THIS TIME AND HAS
SHIFTED WINDS MORE TO THE WEST OVER WESTERN LAKE SUPERIOR. THE COLD
TEMPS HAVE LED TO LAKE EFFECT SNOW IN THE WESTERLY WIND SNOW BELTS.
LOOKING AT WEBCAMS...IT IS TOUGH TO GET A HANDLE ON THE AMOUNT OF
SNOW THAT HAS FALLEN DUE TO THE STRONG WINDS...BUT IT LOOKS TO HAVE
PRODUCED A FEW INCHES IN THE HOUGHTON/CALUMET AREA. THE WINDS HAVE
HELPED CONTRIBUTE TO VISIBILITIES FALLING TO OR BELOW A MILE AT
TIMES AS THEY CONTINUE TO GUST TO 35-40KTS IN THE KEWEENAW.
EXPECT THE LAKE EFFECT TO CONTINUE THROUGH THE SHORT TERM
PERIOD...BUT THE INTENSITY SHOULD BE ON THE DECREASE DUE TO SEVERAL
FACTORS. FIRST...THE DEEP MOISTURE DIMINISHES AS AN UPPER RIDGE
MOVES OVER THE AREA TODAY AHEAD OF A SECONDARY TROUGH MOVING THROUGH
THE NORTHERN ROCKIES. SUBSIDENCE ALOFT WITH THAT RIDGING WILL HELP
LOWER INVERSION HEIGHTS THROUGH THE DAY TOWARDS 7-8KFT (FROM THE
PRESENT 10KFT). SECOND...THE INCREASED CONVERGENCE SEEN ALONG AND
JUST BEHIND THE SURFACE TROUGH WILL DIMINISH THROUGH THE MORNING
HOURS AS THE WINDS BECOME FAIRLY UNIFORM AROUND 270-280 DEGREES.
THERE IS A SECONDARY TROUGH THAT WILL MOVE THROUGH LATE THIS
AFTERNOON AND EARLY THIS EVENING...AND SHIFT WINDS AROUND TO MORE
290-300 DEGREES. THAT WILL BRING MORE LOCATIONS IN THE WESTERN AND
EASTERN U.P. UNDER SOME LAKE EFFECT SNOW (TRADITIONAL NW WIND SNOW
BELTS). ONE OTHER LIMITING FACTOR WILL BE THE CONTINUED INDICATION
BY THE MODELS OF AN INVERTED-V LOOK TO THE LOW LEVELS. THAT BEING
SAID...THE WEAKENING WINDS WILL INCREASE RESIDENCE TIME AND LEAD TO
LESS FRACTURING OF THE FLAKES FOR TONIGHT...SO WOULDN/T BE SURPRISED
TO SEE A FEW LOCATIONS PICKING UP ONE TO LOCALLY TWO INCHES AS MUCH
OF THE CLOUD WILL BE WITHIN THE DGZ. FOR TODAY...EXPECT DAYTIME
ACCUMULATIONS OF 1-2 INCHES OVER THE KEWEENAW AND MAYBE A TOUCH MORE
OVER FAR NORTHEAST LUCE COUNTY WHERE THE LONGER FETCH WILL CREATE
STRONGER BANDS THAT WILL SHIFT SOUTH ALONG THE LUCE COUNTY SHORELINE
IN THE AFTERNOON. AT THIS POINT...THE 15Z END TIME TO THE WINTER WX
ADVISORY LOOKS PRETTY GOOD AS THAT MATCHES UP WELL WITH THE
DIMINISHING TREND IN BOTH THE WINDS AND DEEPER MOISTURE.
WHILE WINDS ARE STILL GUSTING TO 40KTS OVER PORTIONS OF LAKE
SUPERIOR AND THE KEWEENAW PENINSULA AS OF 3AM...THE WEAKENING
PRESSURE GRADIENT THROUGH THE DAY WILL LEAD TO STEADILY DIMINISHING
WINDS THROUGH THE DAY AND EXPECT THEM TO FALL BELOW GALES OVER LAKE
SUPERIOR BY EARLY EVENING. THAT DIMINISHING WILL CONTINUE THROUGH
THE NIGHT AS THEY SHIFT TO THE NORTHWEST. FINALLY...HIGHS TODAY WILL
RANGE FROM THE UPPER 20S OVER THE WEST TO THE LOWER 30S OVER THE
EAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 525 AM EST FRI NOV 20 2015
AFTER WARM WEATHER SO FAR THIS NOV ACROSS THE UPPER LAKES (AT NWS
MARQUETTE, IT`S BEEN THE WARMEST FIRST 19 DAYS OF NOV ON RECORD)...
SEASONABLY COLD WEATHER WILL BE THE RULE THRU THIS WEEKEND AS A TROF
DOMINATES THE GREAT LAKES REGION. NEXT WEEK...A BUILDING
RIDGE/POSITIVE HEIGHT ANOMALY IN THE GULF OF ALASKA INTO WRN CANADA
WILL FORCE TROFFING INTO THE WRN CONUS...THOUGH THE FLOW WILL BE
SPLIT AND TROF WILL BE POSITIVE TILT. THIS IN TURN WILL FORCE
DOWNSTREAM HEIGHT RISES FROM THE ERN PLAINS TO THE E COAST...
RESULTING IN WARMING FOR THE UPPER LAKES TUE/WED AND PERHAPS THRU
THANKSGIVING DAY. THE BIG UNCERTAINTY THAT MAY IMPACT HOLIDAY TRAVEL
IS HOW QUICKLY THE NRN PORTION OF THE WRN TROF PROGRESSES EASTWARD.
WITH THE SRN STREAM PORTION OF THE TROF STILL HANGING BACK OVER THE
SW STATES/SRN ROCKIES...IT MAY SEND ENERGY NE ALONG THE COLD FRONT
MARKING THE LEADING EDGE OF ARCTIC AIR BEING DRIVEN SE BY THE
POSITIVE HEIGHT ANOMALY IN WRN CANADA...RESULTING IN A BAND OF
WINTRY PCPN SOMEWHERE OVER THE UPPER MISSISSIPPI VALLEY OR WRN GREAT
LAKES LATE WEEK. SEASONABLY COLD WEATHER WILL FOLLOW INTO NEXT
WEEKEND...BUT TONIGHTS 00Z GFS/ECMWF ARE QUICKER PUSHING THE WRN
CANADA POSITIVE HEIGHT ANOMALY EASTWARD...WHICH CUTS OFF THE ARCTIC
AIR BEFORE IT REACHES THE UPPER LAKES. FARTHER OUT...CANADIAN
ENSEMBLES AND THE CFSV2 16 MEMBER ENSEMBLE MEAN FAVOR A RETURN TO
PACIFIC FLOW ACROSS THE NRN CONUS/SRN CANADA. SO...AT THIS
POINT...IT APPEARS AN ABOVE NORMAL TEMP REGIME WILL PROBABALY LOCK
IN AGAIN AFTER THE FIRST FEW DAYS OF DEC. AS FOR PCPN...ONGOING LES
WILL PICK UP SOME SAT AS ENERGY SWINGS SE INTO CNTRL PLAINS THEN NE
INTO THE ERN GREAT LAKES. SYSTEM WILL TRACK FAR ENOUGH S AND SE OF
HERE THAT THE SYNOPTIC SNOW SHIELD SHOULD PASS MOSTLY SE OF THE FCST
AREA. A CLIPPER TYPE SHORTWAVE WILL BRING SOME -SN SUN NIGHT/MON
WITH LAKE ENHANCEMENT OFF LAKE MI POSSIBLE INTO THE FAR ERN FCST
AREA. AFTER A TREND TO DRY WEATHER ON TUE...PCPN WILL RETURN
POSSIBLY AS EARLY AS WED AND CONTINUE INTO FRI.
BEGINNING SAT...SHORTWAVE SWINGING THRU THE PLAINS FRI NIGHT WILL
BEGIN TO SPIN UP A SFC WAVE THAT SHOULD BE IN THE VCNTY OF WRN IL AT
12Z SAT. AS THE SHORTWAVE LIFTS TOWARD THE ERN GREAT LAKES...THE LOW
WILL DEEPEN AND TRACK TO THE VCNTY OF DETROIT BY SAT EVENING. THE
REGIONAL CANADIAN AND NCEP ARW/NMM ARE THE DEEPEST/FARTHEST W
SOLUTIONS AND ARE NEARLY IDENTICAL WITH A TRACK TO NEAR SAGINAW BAY.
THE GFS IS A LITTLE FARTHER SE AND THE NAM/ECMWF ARE
WEAKEST/FARTHEST SE WITH A TRACK TO FAR WRN LAKE ERIE. THE CANADIAN
HAS TRENDED NW/STRONGER SINCE THE 12Z RUN...BUT IT IS WITHIN THE
ENVELOP OF THE LAST 5 SOLUTIONS. THE GFS HAS BEEN VERY CONSISTENT IN
THE LAST 5 RUNS. SINCE THE RELATIVELY WARM WATERS OF THE GREAT LAKES
OFTEN CAN HELP PULL DEVELOPING LOW PRES SYSTEMS TO THE W...
ESPECIALLY EARLY IN THE COLD SEASON...FCST WILL LEAN TOWARD THE
FARTHEST W SOLUTIONS OF THE REGIONAL GEM AND NCEP ARW/NMM. THESE
SOLUTIONS RESULT IN LOW-LEVEL FLOW BACKING MORE AND BECOMING MORE
CYCLONIC ACROSS UPPER MI/LAKE SUPERIOR WITH A PERIOD OF NW TO N FLOW
INCREASING LES COVERAGE OVER NRN UPPER MI. RESULT COULD BE THE
POTENTIAL FOR MDT SNOW ACCUMULATIONS OVER MUCH OF THE NCNTRL AND WRN
FCST AREA. THE NE FRINGE OF THE SYNOPTIC SNOW WOULD ALSO BRUSH THE
SE FCST AREA. WITH FCST SOUNDINGS SHOWING DEEPENING MOISTURE AND
FAIRLY HIGH SNOW TO WATER RATIOS...MAY SEE ADVY TYPE SNOWFALL FOR
THE NW TO N WIND FAVORED SNOWBELTS WITH THE MAIN TIME FRAME FOR THE
HEAVIER SNOW ROUGHLY IN THE 18Z SAT TO 06Z SUN TIME PERIOD. OFFICIAL
FCST WILL SHOW 12HR SNOW AMOUNTS OF 2-4 INCHES WHICH IS JUST UNDER
ADVY THRESHOLD FOR LES/HIGH SNOW TO WATER RATIO SNOW. NRN FRINGE OF
SYNOPTIC SNOW SHOULD ONLY YIELD AN INCH OR LESS ACROSS THE SCNTRL/SE
FCST AREA.
BACKING WINDS/DRYING AIR MASS AS HIGH PRES RIDGE ARRIVES SUN WILL
DIMINISH LINGERING LES. IN FACT...EXPECT ALL LES TO END BY LATE
AFTN AS WINDS BACK.
SUN NIGHT/MON...ATTENTION TURNS TO A CLIPPER TYPE SHORTWAVE THAT
REACHES THE UPPER GREAT LAKES MON MORNING. WAA/ISENTROPIC ASCENT
SHOULD YIELD SOME -SN SPREADING ACROSS THE AREA SUN NIGHT WITH
ACCUMULATIONS PROBABLY UNDER 1 INCH. OF MORE CONCERN IS THE BACKING
WINDS WHICH MAY BACK ENOUGH TO LEAD TO LAKE ENHANCEMENT OFF LAKE
MICHIGAN INTO THE FAR ERN FCST AREA SUN NIGHT. FOR NOW...INCREASED
POPS GENERALLY ALONG E OF KISQ/KERY LINE WITH A COUPLE OF INCHES OF
SNOW POSSIBLE.
SOME LIGHT WNW FLOW LES WILL BE POSSIBLE BEHIND THE SHORTWAVE INTO
MON NIGHT. DRY WEATHER WILL RETURN TUE UNDER WAA/BACKING WINDS.
AS ALLUDED TO ABOVE...THE BIG UNCERTAINTY LATER NEXT WEEK WILL BE
HOW QUICKLY THE NRN PORTION OF THE WRN TROF PROGRESSES EASTWARD.
WITH THE SRN STREAM PORTION OF THE TROF HANGING BACK OVER THE SW
STATES/SRN ROCKIES...THERE WILL BE THE POTENTIAL FOR A DECENT PCPN
EVENT ALONG THE COLD FRONT MOVING INTO THE GREAT LAKES. AT THIS
POINT...RECENT GFS/ECMWF RUNS SUGGEST RAIN DEVELOPING LATE WED INTO
THANKSGIVING DAY WITH A TRANSITION TO SNOW FROM NW TO SE
THANKSGIVING NIGHT/FRI. IT REMAINS TO BE SEEN WHETHER THIS WILL
DEVELOP INTO A SIGNIFICANT PCPN EVENT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 636 AM EST FRI NOV 20 2015
LAKE EFFECT SNOW SHOWERS WILL CONTINUE AT KCMX THROUGH THE PERIOD
BUT SHOULD SEE SOME DECREASE IN INTENSITY THROUGH THE DAY TODAY
WHICH WHEN COMBINED WITH WEAKENING WINDS SHOULD PUSH VISIBILITIES
UP. STILL EXPECT CONDITIONS TO BE IN THE MVFR RANGE WHEN THE SNOW
BANDS ARE AFFECTING THE SITE AFTER THE IFR CONDITIONS THIS MORNING.
AT KIWD...EXPECT BORDERLINE MVFR/VFR CONDITIONS FOR A PERIOD THIS
MORNING BASED ON UPSTREAM OBS...THEN TREND TO VFR AROUND MID DAY.
AS WINDS TURN MORE FAVORABLE FOR LAKE EFFECT THROUGH THE EVENING
HOURS...EXPECT CEILINGS AND VISIBILITIES TO TREND BACK DOWN TO
MVFR. FINALLY FOR KSAW...DOWNSLOPING WESTERLY WINDS TODAY AND
NORTHWEST TONIGHT WILL KEEP VFR CONDITIONS IN PLACE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 322 AM EST FRI NOV 20 2015
A TROUGH ASSOCIATED WITH A STRONG LOW PRESSURE SYSTEM OVER HUDSON
BAY WILL CROSS LAKE SUPERIOR THIS EVENING. OVER-WATER INSTABILITY
COMBINED WITH A STRONG PRESSURE GRADIENT WILL RESULT IN WSW STORM
FORCE WINDS TO 50 KNOTS FOR MUCH OF THE OPEN WATERS OF WEST AND
CENTRAL LAKE SUPERIOR THIS EVENING. ONCE THE TROUGH COMPLETELY
CROSSES THE LAKE OVERNIGHT...WINDS WILL SHIFT TO THE WEST AND GUST
TO GALES TO 35-40 KTS THROUGH MUCH OF FRIDAY. THESE STRONG WINDS
WILL DIMINISH STEADILY TO UNDER 25 KTS ON FRI NIGHT/SAT WITH THE
APPROACH OF A WEAK HI PRESSURE RIDGE. A STRONGER N TO NW FLOW UP TO
30 KTS IS POSSIBLE ON SAT NIGHT DEPENDING ON THE TRACK OF A LO PRES
MOVING NE THRU SE ONTARIO. THE FLOW WILL THEN SHIFT TO THE SW UP TO
25 KTS BY LATE SUN INTO MON AS A TRAILING HI PRES RIDGE CROSSES THE
UPPER LAKES AND AHEAD OF ANOTHER LO PRES TROUGH APPROACHING FROM THE
NW. FOLLOWING THE TROF PASSAGE...EXPECT W TO NW WINDS UP TO 25 KTS
ON MON INTO TUE...BUT THEN WINDS WILL SHIFT BACK TO THE SW BY
LATER ON TUE AFTER TRAILING HI PRES SHIFTS TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ001-
003.
LAKESHORE FLOOD ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ001-
003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ248>251-264>267.
GALE WARNING UNTIL 5 PM EST /4 PM CST/ THIS AFTERNOON FOR
LSZ241>245.
GALE WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR LSZ162-
240-246-247.
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LSZ263.
LAKE MICHIGAN...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
527 AM EST FRI NOV 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM EST FRI NOV 20 2015
AN UPPER TROUGH OVER ONTARIO IS LEADING TO THE COLDEST AIR THAT WE
HAVE SEEN THIS FALL...WITH 850MB TEMPS -12C AT KINL AT 00Z AND THAT
MATCHES THE RAP ANALYSIS OVER WESTERN LAKE SUPERIOR. A SECONDARY
TROUGH ASSOCIATED WITH THE STRONG LOW OVER HUDSON BAY IS SLOWLY
MOVING EAST ACROSS CENTRAL LAKE SUPERIOR AT THIS TIME AND HAS
SHIFTED WINDS MORE TO THE WEST OVER WESTERN LAKE SUPERIOR. THE COLD
TEMPS HAVE LED TO LAKE EFFECT SNOW IN THE WESTERLY WIND SNOW BELTS.
LOOKING AT WEBCAMS...IT IS TOUGH TO GET A HANDLE ON THE AMOUNT OF
SNOW THAT HAS FALLEN DUE TO THE STRONG WINDS...BUT IT LOOKS TO HAVE
PRODUCED A FEW INCHES IN THE HOUGHTON/CALUMET AREA. THE WINDS HAVE
HELPED CONTRIBUTE TO VISIBILITIES FALLING TO OR BELOW A MILE AT
TIMES AS THEY CONTINUE TO GUST TO 35-40KTS IN THE KEWEENAW.
EXPECT THE LAKE EFFECT TO CONTINUE THROUGH THE SHORT TERM
PERIOD...BUT THE INTENSITY SHOULD BE ON THE DECREASE DUE TO SEVERAL
FACTORS. FIRST...THE DEEP MOISTURE DIMINISHES AS AN UPPER RIDGE
MOVES OVER THE AREA TODAY AHEAD OF A SECONDARY TROUGH MOVING THROUGH
THE NORTHERN ROCKIES. SUBSIDENCE ALOFT WITH THAT RIDGING WILL HELP
LOWER INVERSION HEIGHTS THROUGH THE DAY TOWARDS 7-8KFT (FROM THE
PRESENT 10KFT). SECOND...THE INCREASED CONVERGENCE SEEN ALONG AND
JUST BEHIND THE SURFACE TROUGH WILL DIMINISH THROUGH THE MORNING
HOURS AS THE WINDS BECOME FAIRLY UNIFORM AROUND 270-280 DEGREES.
THERE IS A SECONDARY TROUGH THAT WILL MOVE THROUGH LATE THIS
AFTERNOON AND EARLY THIS EVENING...AND SHIFT WINDS AROUND TO MORE
290-300 DEGREES. THAT WILL BRING MORE LOCATIONS IN THE WESTERN AND
EASTERN U.P. UNDER SOME LAKE EFFECT SNOW (TRADITIONAL NW WIND SNOW
BELTS). ONE OTHER LIMITING FACTOR WILL BE THE CONTINUED INDICATION
BY THE MODELS OF AN INVERTED-V LOOK TO THE LOW LEVELS. THAT BEING
SAID...THE WEAKENING WINDS WILL INCREASE RESIDENCE TIME AND LEAD TO
LESS FRACTURING OF THE FLAKES FOR TONIGHT...SO WOULDN/T BE SURPRISED
TO SEE A FEW LOCATIONS PICKING UP ONE TO LOCALLY TWO INCHES AS MUCH
OF THE CLOUD WILL BE WITHIN THE DGZ. FOR TODAY...EXPECT DAYTIME
ACCUMULATIONS OF 1-2 INCHES OVER THE KEWEENAW AND MAYBE A TOUCH MORE
OVER FAR NORTHEAST LUCE COUNTY WHERE THE LONGER FETCH WILL CREATE
STRONGER BANDS THAT WILL SHIFT SOUTH ALONG THE LUCE COUNTY SHORELINE
IN THE AFTERNOON. AT THIS POINT...THE 15Z END TIME TO THE WINTER WX
ADVISORY LOOKS PRETTY GOOD AS THAT MATCHES UP WELL WITH THE
DIMINISHING TREND IN BOTH THE WINDS AND DEEPER MOISTURE.
WHILE WINDS ARE STILL GUSTING TO 40KTS OVER PORTIONS OF LAKE
SUPERIOR AND THE KEWEENAW PENINSULA AS OF 3AM...THE WEAKENING
PRESSURE GRADIENT THROUGH THE DAY WILL LEAD TO STEADILY DIMINISHING
WINDS THROUGH THE DAY AND EXPECT THEM TO FALL BELOW GALES OVER LAKE
SUPERIOR BY EARLY EVENING. THAT DIMINISHING WILL CONTINUE THROUGH
THE NIGHT AS THEY SHIFT TO THE NORTHWEST. FINALLY...HIGHS TODAY WILL
RANGE FROM THE UPPER 20S OVER THE WEST TO THE LOWER 30S OVER THE
EAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 525 AM EST FRI NOV 20 2015
AFTER WARM WEATHER SO FAR THIS NOV ACROSS THE UPPER LAKES (AT NWS
MARQUETTE, IT`S BEEN THE WARMEST FIRST 19 DAYS OF NOV ON RECORD)...
SEASONABLY COLD WEATHER WILL BE THE RULE THRU THIS WEEKEND AS A TROF
DOMINATES THE GREAT LAKES REGION. NEXT WEEK...A BUILDING
RIDGE/POSITIVE HEIGHT ANOMALY IN THE GULF OF ALASKA INTO WRN CANADA
WILL FORCE TROFFING INTO THE WRN CONUS...THOUGH THE FLOW WILL BE
SPLIT AND TROF WILL BE POSITIVE TILT. THIS IN TURN WILL FORCE
DOWNSTREAM HEIGHT RISES FROM THE ERN PLAINS TO THE E COAST...
RESULTING IN WARMING FOR THE UPPER LAKES TUE/WED AND PERHAPS THRU
THANKSGIVING DAY. THE BIG UNCERTAINTY THAT MAY IMPACT HOLIDAY TRAVEL
IS HOW QUICKLY THE NRN PORTION OF THE WRN TROF PROGRESSES EASTWARD.
WITH THE SRN STREAM PORTION OF THE TROF STILL HANGING BACK OVER THE
SW STATES/SRN ROCKIES...IT MAY SEND ENERGY NE ALONG THE COLD FRONT
MARKING THE LEADING EDGE OF ARCTIC AIR BEING DRIVEN SE BY THE
POSITIVE HEIGHT ANOMALY IN WRN CANADA...RESULTING IN A BAND OF
WINTRY PCPN SOMEWHERE OVER THE UPPER MISSISSIPPI VALLEY OR WRN GREAT
LAKES LATE WEEK. SEASONABLY COLD WEATHER WILL FOLLOW INTO NEXT
WEEKEND...BUT TONIGHTS 00Z GFS/ECMWF ARE QUICKER PUSHING THE WRN
CANADA POSITIVE HEIGHT ANOMALY EASTWARD...WHICH CUTS OFF THE ARCTIC
AIR BEFORE IT REACHES THE UPPER LAKES. FARTHER OUT...CANADIAN
ENSEMBLES AND THE CFSV2 16 MEMBER ENSEMBLE MEAN FAVOR A RETURN TO
PACIFIC FLOW ACROSS THE NRN CONUS/SRN CANADA. SO...AT THIS
POINT...IT APPEARS AN ABOVE NORMAL TEMP REGIME WILL PROBABALY LOCK
IN AGAIN AFTER THE FIRST FEW DAYS OF DEC. AS FOR PCPN...ONGOING LES
WILL PICK UP SOME SAT AS ENERGY SWINGS SE INTO CNTRL PLAINS THEN NE
INTO THE ERN GREAT LAKES. SYSTEM WILL TRACK FAR ENOUGH S AND SE OF
HERE THAT THE SYNOPTIC SNOW SHIELD SHOULD PASS MOSTLY SE OF THE FCST
AREA. A CLIPPER TYPE SHORTWAVE WILL BRING SOME -SN SUN NIGHT/MON
WITH LAKE ENHANCEMENT OFF LAKE MI POSSIBLE INTO THE FAR ERN FCST
AREA. AFTER A TREND TO DRY WEATHER ON TUE...PCPN WILL RETURN
POSSIBLY AS EARLY AS WED AND CONTINUE INTO FRI.
BEGINNING SAT...SHORTWAVE SWINGING THRU THE PLAINS FRI NIGHT WILL
BEGIN TO SPIN UP A SFC WAVE THAT SHOULD BE IN THE VCNTY OF WRN IL AT
12Z SAT. AS THE SHORTWAVE LIFTS TOWARD THE ERN GREAT LAKES...THE LOW
WILL DEEPEN AND TRACK TO THE VCNTY OF DETROIT BY SAT EVENING. THE
REGIONAL CANADIAN AND NCEP ARW/NMM ARE THE DEEPEST/FARTHEST W
SOLUTIONS AND ARE NEARLY IDENTICAL WITH A TRACK TO NEAR SAGINAW BAY.
THE GFS IS A LITTLE FARTHER SE AND THE NAM/ECMWF ARE
WEAKEST/FARTHEST SE WITH A TRACK TO FAR WRN LAKE ERIE. THE CANADIAN
HAS TRENDED NW/STRONGER SINCE THE 12Z RUN...BUT IT IS WITHIN THE
ENVELOP OF THE LAST 5 SOLUTIONS. THE GFS HAS BEEN VERY CONSISTENT IN
THE LAST 5 RUNS. SINCE THE RELATIVELY WARM WATERS OF THE GREAT LAKES
OFTEN CAN HELP PULL DEVELOPING LOW PRES SYSTEMS TO THE W...
ESPECIALLY EARLY IN THE COLD SEASON...FCST WILL LEAN TOWARD THE
FARTHEST W SOLUTIONS OF THE REGIONAL GEM AND NCEP ARW/NMM. THESE
SOLUTIONS RESULT IN LOW-LEVEL FLOW BACKING MORE AND BECOMING MORE
CYCLONIC ACROSS UPPER MI/LAKE SUPERIOR WITH A PERIOD OF NW TO N FLOW
INCREASING LES COVERAGE OVER NRN UPPER MI. RESULT COULD BE THE
POTENTIAL FOR MDT SNOW ACCUMULATIONS OVER MUCH OF THE NCNTRL AND WRN
FCST AREA. THE NE FRINGE OF THE SYNOPTIC SNOW WOULD ALSO BRUSH THE
SE FCST AREA. WITH FCST SOUNDINGS SHOWING DEEPENING MOISTURE AND
FAIRLY HIGH SNOW TO WATER RATIOS...MAY SEE ADVY TYPE SNOWFALL FOR
THE NW TO N WIND FAVORED SNOWBELTS WITH THE MAIN TIME FRAME FOR THE
HEAVIER SNOW ROUGHLY IN THE 18Z SAT TO 06Z SUN TIME PERIOD. OFFICIAL
FCST WILL SHOW 12HR SNOW AMOUNTS OF 2-4 INCHES WHICH IS JUST UNDER
ADVY THRESHOLD FOR LES/HIGH SNOW TO WATER RATIO SNOW. NRN FRINGE OF
SYNOPTIC SNOW SHOULD ONLY YIELD AN INCH OR LESS ACROSS THE SCNTRL/SE
FCST AREA.
BACKING WINDS/DRYING AIR MASS AS HIGH PRES RIDGE ARRIVES SUN WILL
DIMINISH LINGERING LES. IN FACT...EXPECT ALL LES TO END BY LATE
AFTN AS WINDS BACK.
SUN NIGHT/MON...ATTENTION TURNS TO A CLIPPER TYPE SHORTWAVE THAT
REACHES THE UPPER GREAT LAKES MON MORNING. WAA/ISENTROPIC ASCENT
SHOULD YIELD SOME -SN SPREADING ACROSS THE AREA SUN NIGHT WITH
ACCUMULATIONS PROBABLY UNDER 1 INCH. OF MORE CONCERN IS THE BACKING
WINDS WHICH MAY BACK ENOUGH TO LEAD TO LAKE ENHANCEMENT OFF LAKE
MICHIGAN INTO THE FAR ERN FCST AREA SUN NIGHT. FOR NOW...INCREASED
POPS GENERALLY ALONG E OF KISQ/KERY LINE WITH A COUPLE OF INCHES OF
SNOW POSSIBLE.
SOME LIGHT WNW FLOW LES WILL BE POSSIBLE BEHIND THE SHORTWAVE INTO
MON NIGHT. DRY WEATHER WILL RETURN TUE UNDER WAA/BACKING WINDS.
AS ALLUDED TO ABOVE...THE BIG UNCERTAINTY LATER NEXT WEEK WILL BE
HOW QUICKLY THE NRN PORTION OF THE WRN TROF PROGRESSES EASTWARD.
WITH THE SRN STREAM PORTION OF THE TROF HANGING BACK OVER THE SW
STATES/SRN ROCKIES...THERE WILL BE THE POTENTIAL FOR A DECENT PCPN
EVENT ALONG THE COLD FRONT MOVING INTO THE GREAT LAKES. AT THIS
POINT...RECENT GFS/ECMWF RUNS SUGGEST RAIN DEVELOPING LATE WED INTO
THANKSGIVING DAY WITH A TRANSITION TO SNOW FROM NW TO SE
THANKSGIVING NIGHT/FRI. IT REMAINS TO BE SEEN WHETHER THIS WILL
DEVELOP INTO A SIGNIFICANT PCPN EVENT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1231 AM EST FRI NOV 20 2015
WINDY CONDITIONS WILL CONTINUE AT ALL SITES THROUGH TONIGHT BEFORE
GRADUALLY DIMINISHING THROUGH THE DAY FRIDAY. WESTERLY GUSTS AS HIGH
AS 40 KTS ARE EXPECTED AT CMX THAT WILL TAPER OFF SLIGHTLY
OVERNIGHT. CMX THROUGHTHIS EVENING...WHILE GUSTS OF 25-305 KNOTS ARE
EXPECTED FOR IWD AND SAW.
HEAVIER LAKE EFFECT SNOW BANDS ARE FORECAST TO FOCUS ACROSS THE
KEWEENAW PENINSULA OVERNIGHT. THIS COMBINED WITH THE GUSTY WINDS
WILL LIKELY BRING IFR TO POSSIBLY LIFR VIS TO CMX VSBY WITH MAINLY
MVFR CIGS THROUGH MUCH OF THE NIGHT. VSBY WILL IMPROVE TO MVFR BY
FRI AFTERNOON AS DRIER AIR MOVES INTO THE REGION. AT IWD AND
SAW...HIGH-END MVFR TO LOW-END VFR CIGS AND ISOLATED TO SCATTERED -
SHSN ARE FORECAST THROUGH THE PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 322 AM EST FRI NOV 20 2015
A TROUGH ASSOCIATED WITH A STRONG LOW PRESSURE SYSTEM OVER HUDSON
BAY WILL CROSS LAKE SUPERIOR THIS EVENING. OVER-WATER INSTABILITY
COMBINED WITH A STRONG PRESSURE GRADIENT WILL RESULT IN WSW STORM
FORCE WINDS TO 50 KNOTS FOR MUCH OF THE OPEN WATERS OF WEST AND
CENTRAL LAKE SUPERIOR THIS EVENING. ONCE THE TROUGH COMPLETELY
CROSSES THE LAKE OVERNIGHT...WINDS WILL SHIFT TO THE WEST AND GUST
TO GALES TO 35-40 KTS THROUGH MUCH OF FRIDAY. THESE STRONG WINDS
WILL DIMINISH STEADILY TO UNDER 25 KTS ON FRI NIGHT/SAT WITH THE
APPROACH OF A WEAK HI PRESSURE RIDGE. A STRONGER N TO NW FLOW UP TO
30 KTS IS POSSIBLE ON SAT NIGHT DEPENDING ON THE TRACK OF A LO PRES
MOVING NE THRU SE ONTARIO. THE FLOW WILL THEN SHIFT TO THE SW UP TO
25 KTS BY LATE SUN INTO MON AS A TRAILING HI PRES RIDGE CROSSES THE
UPPER LAKES AND AHEAD OF ANOTHER LO PRES TROUGH APPROACHING FROM THE
NW. FOLLOWING THE TROF PASSAGE...EXPECT W TO NW WINDS UP TO 25 KTS
ON MON INTO TUE...BUT THEN WINDS WILL SHIFT BACK TO THE SW BY
LATER ON TUE AFTER TRAILING HI PRES SHIFTS TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ001-
003.
LAKESHORE FLOOD ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ001-
003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ248>251-264>267.
GALE WARNING UNTIL 5 PM EST /4 PM CST/ THIS AFTERNOON FOR
LSZ241>245.
GALE WARNING UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON FOR LSZ162-
240-246-247.
GALE WARNING UNTIL 4 PM EST THIS AFTERNOON FOR LSZ263.
LAKE MICHIGAN...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
323 AM EST FRI NOV 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 322 AM EST FRI NOV 20 2015
AN UPPER TROUGH OVER ONTARIO IS LEADING TO THE COLDEST AIR THAT WE
HAVE SEEN THIS FALL...WITH 850MB TEMPS -12C AT KINL AT 00Z AND THAT
MATCHES THE RAP ANALYSIS OVER WESTERN LAKE SUPERIOR. A SECONDARY
TROUGH ASSOCIATED WITH THE STRONG LOW OVER HUDSON BAY IS SLOWLY
MOVING EAST ACROSS CENTRAL LAKE SUPERIOR AT THIS TIME AND HAS
SHIFTED WINDS MORE TO THE WEST OVER WESTERN LAKE SUPERIOR. THE COLD
TEMPS HAVE LED TO LAKE EFFECT SNOW IN THE WESTERLY WIND SNOW BELTS.
LOOKING AT WEBCAMS...IT IS TOUGH TO GET A HANDLE ON THE AMOUNT OF
SNOW THAT HAS FALLEN DUE TO THE STRONG WINDS...BUT IT LOOKS TO HAVE
PRODUCED A FEW INCHES IN THE HOUGHTON/CALUMET AREA. THE WINDS HAVE
HELPED CONTRIBUTE TO VISIBILITIES FALLING TO OR BELOW A MILE AT
TIMES AS THEY CONTINUE TO GUST TO 35-40KTS IN THE KEWEENAW.
EXPECT THE LAKE EFFECT TO CONTINUE THROUGH THE SHORT TERM
PERIOD...BUT THE INTENSITY SHOULD BE ON THE DECREASE DUE TO SEVERAL
FACTORS. FIRST...THE DEEP MOISTURE DIMINISHES AS AN UPPER RIDGE
MOVES OVER THE AREA TODAY AHEAD OF A SECONDARY TROUGH MOVING THROUGH
THE NORTHERN ROCKIES. SUBSIDENCE ALOFT WITH THAT RIDGING WILL HELP
LOWER INVERSION HEIGHTS THROUGH THE DAY TOWARDS 7-8KFT (FROM THE
PRESENT 10KFT). SECOND...THE INCREASED CONVERGENCE SEEN ALONG AND
JUST BEHIND THE SURFACE TROUGH WILL DIMINISH THROUGH THE MORNING
HOURS AS THE WINDS BECOME FAIRLY UNIFORM AROUND 270-280 DEGREES.
THERE IS A SECONDARY TROUGH THAT WILL MOVE THROUGH LATE THIS
AFTERNOON AND EARLY THIS EVENING...AND SHIFT WINDS AROUND TO MORE
290-300 DEGREES. THAT WILL BRING MORE LOCATIONS IN THE WESTERN AND
EASTERN U.P. UNDER SOME LAKE EFFECT SNOW (TRADITIONAL NW WIND SNOW
BELTS). ONE OTHER LIMITING FACTOR WILL BE THE CONTINUED INDICATION
BY THE MODELS OF AN INVERTED-V LOOK TO THE LOW LEVELS. THAT BEING
SAID...THE WEAKENING WINDS WILL INCREASE RESIDENCE TIME AND LEAD TO
LESS FRACTURING OF THE FLAKES FOR TONIGHT...SO WOULDN/T BE SURPRISED
TO SEE A FEW LOCATIONS PICKING UP ONE TO LOCALLY TWO INCHES AS MUCH
OF THE CLOUD WILL BE WITHIN THE DGZ. FOR TODAY...EXPECT DAYTIME
ACCUMULATIONS OF 1-2 INCHES OVER THE KEWEENAW AND MAYBE A TOUCH MORE
OVER FAR NORTHEAST LUCE COUNTY WHERE THE LONGER FETCH WILL CREATE
STRONGER BANDS THAT WILL SHIFT SOUTH ALONG THE LUCE COUNTY SHORELINE
IN THE AFTERNOON. AT THIS POINT...THE 15Z END TIME TO THE WINTER WX
ADVISORY LOOKS PRETTY GOOD AS THAT MATCHES UP WELL WITH THE
DIMINISHING TREND IN BOTH THE WINDS AND DEEPER MOISTURE.
WHILE WINDS ARE STILL GUSTING TO 40KTS OVER PORTIONS OF LAKE
SUPERIOR AND THE KEWEENAW PENINSULA AS OF 3AM...THE WEAKENING
PRESSURE GRADIENT THROUGH THE DAY WILL LEAD TO STEADILY DIMINISHING
WINDS THROUGH THE DAY AND EXPECT THEM TO FALL BELOW GALES OVER LAKE
SUPERIOR BY EARLY EVENING. THAT DIMINISHING WILL CONTINUE THROUGH
THE NIGHT AS THEY SHIFT TO THE NORTHWEST. FINALLY...HIGHS TODAY WILL
RANGE FROM THE UPPER 20S OVER THE WEST TO THE LOWER 30S OVER THE
EAST.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 440 PM EST THU NOV 19 2015
A RETURN TO COLDER...MORE SEASONABLE NOV WX IS IN STORE THIS WEEKEND
AS A SHRTWV DIGGING INTO THE PLAINS AMPLIFIES AN UPR TROF OVER THE
GREAT LKS. ALTHOUGH MUCH OF THE SYNOPTIC SN ASSOCIATED WITH THE
ACCOMPANYING SFC LO TRACKING THRU THE LOWER LKS WL MISS THE CWA TO
THE S...SOME LES WL BE LIKELY IN THE FAVORED SN BELTS NEAR LK SUP.
THERE COULD BE ANOTHER PERIOD OF SN ON SUN NGT INTO MON BEFORE A
PATTERN CHANGE THAT FEATURES A BLDG UPR RDG OVER THE ERN CONUS/
DOWNSTREAM OF TROFFING OVER THE W BRINGS A RETURN OF MILDER WX THE
MIDDLE OF NEXT WEEK. THE EXTENDED FCST FOR THANKSGIVING DAY MAY
INCLUDE SOME RAIN AS A STRENGTHENING SLY FLOW TO THE E OF A LO PRES
MOVING NEWD THRU THE PLAINS ADVECTS MOISTER AIR INTO THE UPR LKS.
FRI NGT...SHRTWV DIGGING INTO THE PLAINS IS FCST TO AMPLIFY UPR TROF
AXIS CENTERED OVER THE NRN PLAINS. AN ACCOMPANYING SFC LO PRES WL BE
TAKING SHAPE OVER THE MID MS RIVER VALLEY BY 12Z. OVER UPR MI...A
CYC WNW FLOW IS FCST TO WEAKEN AND GIVE WAY TO A WEAK HI PRES RDG
AXIS NOSING INTO THE UPR LKS TO THE N OF THE DVLPG LO TO THE S. LES
IN THE CHILLY WNW SLOWLY VEERING NW FLOW...WITH H85 TEMPS ARND
-12C...WL PERSIST THRU THE NGT BUT BE LIMITED IN INTENSITY AND
COVERAGE BY LARGER SCALE DEEP LYR QVECTOR DVGC/SUBSIDENCE...ABSENCE
OF SHARP LLVL CNVGC...AND LLVL DRY AIR THAT SHOWS UP AS AN INVERTED
V T/TD PROFILE ON FCST SDNGS.
SAT/SAT NGT...DEEPENING SFC LO PRES AHEAD OF DIGGING SHRTWV IS FCST
TO MOVE TO SE LOWER MI BY 00Z SUN AND THEN TO NEAR THE ONTARIO/
QUEBEC BORDER JUST S OF JAMES BAY AT 12Z SUN. THE 12Z GFS/00Z
CNDN/09Z SREF MODELS SHOW A SOMEWHAT DEEPER SFC LO PRES/SHARPER CYC
FLOW AND FARTHER W TRACK ASSOCIATED WITH MORE PHASING BTWN THE
DIGGING SHRTWV AND ANOTHER DISTURBANCE FARTHER TO THE N IN MN. THESE
MODELS INDICATE THE NW EDGE OF THE SHARPER FORCING WL AT LEAST BRUSH
THE SE CWA SAT AFTN/EVNG. SINCE THE 00Z GFS ENSEMBLE MEAN SUPPORTS
THE SOMEWHAT WEAKER/FARTHER E TRACK DEPICTED BY THE 12Z NAM/12Z
CNDN/00Z AND 12Z ECMWF...WL TEND TOWARD THAT SCENARIO PER THE LATEST
NCEP GUIDANCE. EVEN IF THE 12Z GFS IS CORRECT...FCST H7-75 SPECIFIC
HUMIDITY JUST A BIT MORE THAN 1 G/KG OVER THE SE CWA WOULD SUPPORT
ONLY AN INCH OR TWO OF SN DURING THE 6-9 HR PERIOD THE DEEP LYR
QVECTOR CNVGC IS FCST TO BE IN PLACE. OF MORE CONCERN IS THE
POTENTIAL FOR LK EFFECT SN NEAR LK SUP AS H85 TEMPS NEAR -15C DROP
OVER THE UPR LKS IN THE EXPECTED LLVL NNW FLOW AND UNDER AN AREA OF
SOME DEEPER MSTR. NAM FCST SDNGS FOR IRONWOOD AND NEWBERRY SHOW SOME
FAIRLY SHARP UVV AT TIMES WITHIN THE DGZ RANGING IN HGT FM 3-8K FT
AGL ON SAT AND SAT NGT. SO LES AT SOME LOCATIONS IN THE FAVORED SN
BELTS MAY AT LEAST APRCH ADVY CRITERIA DURING THIS PERIOD. SLOWLY
SHIFTING WINDS THAT LIMIT SN BAND RESIDENCE TIME WL LOWER THIS
POTENTIAL.
SUN...AS THE CNDN LO SHIFTS TO THE NE INTO NRN QUEBEC...A TRAILING
SFC RDG AXIS IS FCST TO PUSH W-E THRU THE UPR LKS. THE COMBINATION
OF THE INCRSG ACYC FLOW/LLVL DRYING AND DEEP LYR QVECTOR DVGC WL
DIMINISH LINGERING LES. BUT FCST WL SHOW CATEGORICAL LES POPS IN THE
SN BELTS E OF MARQUETTE DURING THE MRNG BEFORE THE CLOSER APRCH OF
THE RDG AXIS IN THE AFTN. ALTHOUGH THERE WL BE AT LEAST SOME PARTIAL
CLRG AS WELL WITH THE ARRIVAL OF THE RDG AXIS... INCRSG SW FLOW/
ISENTROPIC ASCENT ON THE WRN FLANK OF THE PASSING RDG AXIS AND AHEAD
OF NEXT SHRTWV/SFC LO DIGGING SE THRU SCENTRAL CANADA WL BRING
INCRSG MID CLDS DURING THE AFTN.
SUN NGT/MON...NEXT SHRTWV IS PROGGED TO SLIDE SE NEAR OR JUST TO THE
N OF UPR MI. THE 00Z ECWMF SHOWED THE FARTHER N TRACK...WHILE THE
12Z CNDN MODEL IS FARTHER S WITH THE DISTRUBANCE/SFC LO TRACKING
OVER UPR MI. BAND OF INCRSG MID LVL MSTR TIED BEST TO ISENTROPIC
ASCENT SHOWN ON THE 280-285K SFCS WL SUPPORT AT LEAST A CHC OF SOME
SNOW...WITH TRACK OF DISTURBANCE KEY IN THE LOCATION OF THE HIER
POPS. CONSIDERING THE UNCERTAINTY ON THE TRACK OF THE DISTURBANCE...
FCST WL SHOW NO HIER THAN CHC POPS. IF THE FARTHER N TRACK OF THE
DISTURBANCE VERIFIES...SOME LK ENHANCEMENT OFF LK MI COULD AT LEAST
BRUSH THE FAR ERN CWA WITH H85 TEMPS ARND -9C IN LLVL SSW FLOW ON
SUN NGT FOR AT LEAST A SHORT TIME.
MON NGT INTO TUE...NW FLOW ON THE BACK SIDE OF DEPARTING SHRTWV/SFC
LO WL ADVECT AIR SUFFICIENTLY COLD...WITH H85 TEMPS AS LO AS -8C TO -
9C... TO SUPPORT AT LEAST A CHC FOR SOME LES IN THE FAVORED SN BELTS
INTO TUE MRNG.
EXTENDED...ARRIVAL OF SFC HI PRES RDG UNDER BLDG UPR RDG SHOULD
RESULT IN DRY WX AT LEAST ON TUE. AS THE SLY FLOW BTWN THE HI PRES
EXITING TO THE E TOWARD NEW ENGLAND DVLPG LO PRES IN THE WRN PLAINS
ADVECTS WARMER...MOISTER AIR TOWARD THE UPR LKS ON WED/THU THERE WL
BE INCRSG CLDS AND AT LEAST A CHC OF SOME RAIN...ESPECIALLY ON
THANKSGIVING DAY WHEN A DEEPER SFC LO PRES RIDING TO THE NE ON STNRY
FNT STRETCING FM THE SRN PLAINS INTO THE UPR MS RIVER VALLEY GETS
CLOSER. TEMPS ON WED/THANKSGIVING WL RUN WELL ABOVE NORMAL AS H85
TEMPS ARE FCST TO REACH ARND 6C ON THU.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1231 AM EST FRI NOV 20 2015
WINDY CONDITIONS WILL CONTINUE AT ALL SITES THROUGH TONIGHT BEFORE
GRADUALLY DIMINISHING THROUGH THE DAY FRIDAY. WESTERLY GUSTS AS HIGH
AS 40 KTS ARE EXPECTED AT CMX THAT WILL TAPER OFF SLIGHTLY
OVERNIGHT. CMX THROUGHTHIS EVENING...WHILE GUSTS OF 25-305 KNOTS ARE
EXPECTED FOR IWD AND SAW.
HEAVIER LAKE EFFECT SNOW BANDS ARE FORECAST TO FOCUS ACROSS THE
KEWEENAW PENINSULA OVERNIGHT. THIS COMBINED WITH THE GUSTY WINDS
WILL LIKELY BRING IFR TO POSSIBLY LIFR VIS TO CMX VSBY WITH MAINLY
MVFR CIGS THROUGH MUCH OF THE NIGHT. VSBY WILL IMPROVE TO MVFR BY
FRI AFTERNOON AS DRIER AIR MOVES INTO THE REGION. AT IWD AND
SAW...HIGH-END MVFR TO LOW-END VFR CIGS AND ISOLATED TO SCATTERED -
SHSN ARE FORECAST THROUGH THE PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 322 AM EST FRI NOV 20 2015
A TROUGH ASSOCIATED WITH A STRONG LOW PRESSURE SYSTEM OVER HUDSON
BAY WILL CROSS LAKE SUPERIOR THIS EVENING. OVER-WATER INSTABILITY
COMBINED WITH A STRONG PRESSURE GRADIENT WILL RESULT IN WSW STORM
FORCE WINDS TO 50 KNOTS FOR MUCH OF THE OPEN WATERS OF WEST AND
CENTRAL LAKE SUPERIOR THIS EVENING. ONCE THE TROUGH COMPLETELY
CROSSES THE LAKE OVERNIGHT...WINDS WILL SHIFT TO THE WEST AND GUST
TO GALES TO 35-40 KTS THROUGH MUCH OF FRIDAY. THESE STRONG WINDS
WILL DIMINISH STEADILY TO UNDER 25 KTS ON FRI NIGHT/SAT WITH THE
APPROACH OF A WEAK HI PRESSURE RIDGE. A STRONGER N TO NW FLOW UP TO
30 KTS IS POSSIBLE ON SAT NIGHT DEPENDING ON THE TRACK OF A LO PRES
MOVING NE THRU SE ONTARIO. THE FLOW WILL THEN SHIFT TO THE SW UP TO
25 KTS BY LATE SUN INTO MON AS A TRAILING HI PRES RIDGE CROSSES THE
UPPER LAKES AND AHEAD OF ANOTHER LO PRES TROUGH APPROACHING FROM THE
NW. FOLLOWING THE TROF PASSAGE...EXPECT W TO NW WINDS UP TO 25 KTS
ON MON INTO TUE...BUT THEN WINDS WILL SHIFT BACK TO THE SW BY
LATER ON TUE AFTER TRAILING HI PRES SHIFTS TO THE E.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ001-
003.
LAKESHORE FLOOD ADVISORY UNTIL 10 AM EST THIS MORNING FOR MIZ001-
003.
LAKE SUPERIOR...
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ248>251-264>267.
GALE WARNING UNTIL 5 PM EST /4 PM CST/ THIS AFTERNOON FOR
LSZ240>245.
GALE WARNING UNTIL 1 PM EST THIS AFTERNOON FOR LSZ246-247.
GALE WARNING UNTIL 4 PM EST /3 PM CST/ THIS AFTERNOON FOR LSZ162-
263.
LAKE MICHIGAN...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LMZ221-248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...KC
AVIATION...JLB
MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1107 AM CST FRI NOV 20 2015
.UPDATED FOR 18Z TAF DISCUSSION BELOW...
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM CST FRI NOV 20 2015
WINTER STORM REMAINS ON TRACK TO BRING MODERATE TO HEAVY SNOW ACROSS
NORTHERN IOWA TODAY. THE NORTHERN EDGE OF THIS BAND SHOULD CLIP FAR
SOUTHERN MINNESOTA WITH UP TO 4 INCHES...SO HAVE ISSUED A WINTER
WEATHER ADVISORY BEING THE FIRST SNOWFALL OF THE SEASON. THE SNOW
WILL QUICKLY END TONIGHT...SETTING THE STAGE FOR THE COLDEST NIGHT
OF THE SEASON WITH LOWS IN THE MID TEENS TO LOWER 20S.
THE MODELS HAVE COME INTO BETTER AGREEMENT...AND WITH THE HIRES
SUITE STARTING TO CAPTURE THIS EVENT FEEL FAIRLY CONFIDENT WITH THE
SHORT TERM FORECAST. THE NCAR 10 MEMBER ENSEMBLE DEPICTS THE
UNCERTAINTY BEST...WITH SOME SOLUTIONS SHOWING HARDLY ANY PRECIP
ACROSS SOUTHERN MN...AND OTHERS SHOWING OVER A HALF TO THREE
QUARTERS OF AN INCH. WITH THE ADDITION OF THE HOPWRF AND HRRR FEEL
THAT SOUTHERN MN MAY GET 0.25 TO 0.40 INCHES OF LIQUID...EQUATING TO
2 TO 4 INCHES USING A BLEND OF THE GFS/NAM/AIR FORCE SNOW RATIOS
AT AROUND 10:1 TO 14:1.
A LATENT HEAT VS NON-LATENT HEAT MODEL COMPARISON SHOWS A SOUTHWARD
SHIFT IN THE TRACK FOR THE LATENT HEAT RUN...WHICH RESEMBLES REALITY
MUCH BETTER THAN THE NON-LATENT HEAT RUN...SO THAT IS ANOTHER VOTE
OF CONFIDENCE THAT THE WARNING CRITERIA SNOWFALL WILL STAY TO THE
SOUTH OF THE FORECAST AREA. LOOKING AHEAD...COLD AIR ADVECTION WILL
BRING A REINFORCEMENT OF SEASONABLY COOL AIR ACROSS THE REGION...AND
EXPECT LOW TEMPERATURE NEAR 20 TONIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 416 AM CST FRI NOV 20 2015
THE LONG TERM IS EXPECTED TO BE LARGELY QUIET UNTIL THE LAST HALF
OF NEXT WEEK...RIGHT IN TIME FOR THANKSGIVING AND BLACK FRIDAY. IN
FACT...IT COULD BE QUITE A STORMY END TO THE MONTH.
COLD AND DRY AIR WILL FOLLOW IN THE WAKE OF THE DEPARTING
PLAINS/GREAT LAKES LOW SATURDAY. HIGHS WILL ONLY BE IN THE 20S.
INCREASING CLOUDS ARE EXPECTED LATE SATURDAY AND SATURDAY NIGHT AS
A REINFORCING TROUGH DIGS SOUTHEAST FROM THE CANADIAN ROCKIES.
THIS...IN COMBINATION WITH A BACKING SURFACE FLOW TO THE
SOUTHWEST SHOULD KEEP TEMPERATURES FROM DROPPING INTO THE SINGLE
DIGITS OR LOW TEENS...ASIDE FROM PERHAPS THE SNOWY AREAS ALONG
I-90 IF CLOUDS ARE DELAYED A BIT. DID RAISE LOWS A COUPLE DEGREES
IN MOST LOCATIONS BUT THEY MAY STILL BE TOO COLD.
MEANWHILE...AN UPPER JET STREAK WILL ROUND THE CREST OF THE
WESTERN RIDGE SATURDAY NIGHT. AN ACCOMPANYING LOW PRESSURE SYSTEM
POLEWARD THE JET WILL BEGIN DIVING SOUTHEAST TOWARD THE ARROWHEAD
OF MN SUNDAY EVENING WITH A WARM FRONT EXTENDING TO THE SOUTHEAST
ACROSS WESTERN WI. THERE MAY BE ENOUGH LIFT AND MOISTURE TO BRING
SOME LIGHT SNOW SUNDAY NIGHT NEAR AND EAST OF THE WARM FRONT.
ACCUMULATIONS WOULD BE MINIMAL AND THE REST OF THE CWA WOULD BE
DRY SLOTTED.
AS THAT SYSTEM PUSHES EAST...THE RIDGE WILL BUILD EASTWARD ACROSS
THE PLAINS EARLY NEXT WEEK. MILDER TEMPERATURES WILL RETURN...BUT
NOT TO THE DEGREE SEEN FOR MUCH OF THIS MONTH. MORE IMPORTANTLY...
A TROUGH WILL DIG DOWN THE WEST COAST AND A POTENT CLOSED UPPER
LOW WILL STALL OVER NEVADA AND UTAH FOR THE REST OF THE WEEK.
LATEST GUIDANCE IS IN DECENT AGREEMENT AND SUGGESTS THIS CLOSED
LOW WILL EVENTUALLY PHASE WITH THE POLAR JET ACROSS CANADA AND
RESULT IN A LARGE SCALE POSITIVELY TILTED TROUGH/REX
BLOCK...MAKING IT QUITE DIFFICULT TO FULLY EJECT THE ENERGY FROM
THE SOUTHWEST THROUGH THE END OF THE PERIOD. A LONG FEED FROM THE
TROPICAL PACIFIC WILL SET UP IN THE MID/UPPER LEVELS AND TRANSPORT
QUITE A BIT OF MOISTURE INTO THE PLAINS AND UPPER MIDWEST. STRONG
HIGH PRESSURE /1035-1045MB/ OVER THE NORTHERN ROCKIES WILL AT THE
SAME TIME FEED THE NORTHERN/CENTRAL PLAINS AND UPPER MIDWEST WITH
COLD BOUNDARY LAYER AIR BEHIND THE QUASI-STATIONARY SURFACE
BOUNDARY. THE RESULT COULD BE A PROLONGED WINTRY MESS BEGINNING
WEDNESDAY NIGHT AND CONTINUING THROUGH THE REST OF THE WEEK. KEPT
THE GRIDS A SIMPLE RAIN/SNOW MIX AT THIS RANGE...BUT THERMAL
PROFILES OFF THE GFS AND ECMWF WOULD SUPPORT MORE OF A
SNOW/SLEET/FREEZING RAIN SCENARIO...AND GIVEN THE MOISTURE FEED
AVAILABLE...MAJOR IMPACTS COULD RESULT. STAY TUNED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1115 AM CST FRI NOV 20 2015
VFR CONDITIONS THROUGHOUT. SNOW WILL STAY SOUTH OF THE TAF SITES
TODAY. WINDS WILL BE RELATIVELY LIGHT TODAY...BUT SHOULD INCREASE
LATER TONIGHT WITH GUSTS IN THE MID TEENS POSSIBLE MAINLY OVER THE
EASTERN SITES.
KMSP...
WILL CONTINUE VFR CONDITIONS DURING PERIOD. SOME CHANCE OF MVFR
CIGS MOVING IN AFTER 06Z AS THE UPPER TROUGH SWINGS EAST. APPEARS
KMSP WOULD BE ON THE EDGE OF THE CIGS IF THEY DID OCCUR.
CONFIDENCE IS TOO LOW TO MENTION NOW. WINDS WILL BE RELATIVELY
LIGHT TODAY...BUT SHOULD INCREASE LATER TONIGHT WITH NORTH
NORTHWEST GUSTS IN THE MID TEENS EXPECTED.
/OUTLOOK FOR KMSP/
SAT NITE...VFR. WIND NW AT 5 TO 9KT
SUN...VFR. WIND SW AT 10G20KT.
MON...VFR. WIND WNW AT 10G15KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WINTER WEATHER ADVISORY UNTIL 3 AM CST SATURDAY FOR MNZ091>093.
&&
$$
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
559 AM CST FRI NOV 20 2015
.UPDATED FOR 12Z AVIATION DISCUSSION...
ISSUED AT 548 AM CST FRI NOV 20 2015
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM CST FRI NOV 20 2015
WINTER STORM REMAINS ON TRACK TO BRING MODERATE TO HEAVY SNOW ACROSS
NORTHERN IOWA TODAY. THE NORTHERN EDGE OF THIS BAND SHOULD CLIP FAR
SOUTHERN MINNESOTA WITH UP TO 4 INCHES...SO HAVE ISSUED A WINTER
WEATHER ADVISORY BEING THE FIRST SNOWFALL OF THE SEASON. THE SNOW
WILL QUICKLY END TONIGHT...SETTING THE STAGE FOR THE COLDEST NIGHT
OF THE SEASON WITH LOWS IN THE MID TEENS TO LOWER 20S.
THE MODELS HAVE COME INTO BETTER AGREEMENT...AND WITH THE HIRES
SUITE STARTING TO CAPTURE THIS EVENT FEEL FAIRLY CONFIDENT WITH THE
SHORT TERM FORECAST. THE NCAR 10 MEMBER ENSEMBLE DEPICTS THE
UNCERTAINTY BEST...WITH SOME SOLUTIONS SHOWING HARDLY ANY PRECIP
ACROSS SOUTHERN MN...AND OTHERS SHOWING OVER A HALF TO THREE
QUARTERS OF AN INCH. WITH THE ADDITION OF THE HOPWRF AND HRRR FEEL
THAT SOUTHERN MN MAY GET 0.25 TO 0.40 INCHES OF LIQUID...EQUATING TO
2 TO 4 INCHES USING A BLEND OF THE GFS/NAM/AIR FORCE SNOW RATIOS
AT AROUND 10:1 TO 14:1.
A LATENT HEAT VS NON-LATENT HEAT MODEL COMPARISON SHOWS A SOUTHWARD
SHIFT IN THE TRACK FOR THE LATENT HEAT RUN...WHICH RESEMBLES REALITY
MUCH BETTER THAN THE NON-LATENT HEAT RUN...SO THAT IS ANOTHER VOTE
OF CONFIDENCE THAT THE WARNING CRITERIA SNOWFALL WILL STAY TO THE
SOUTH OF THE FORECAST AREA. LOOKING AHEAD...COLD AIR ADVECTION WILL
BRING A REINFORCEMENT OF SEASONABLY COOL AIR ACROSS THE REGION...AND
EXPECT LOW TEMPERATURE NEAR 20 TONIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 416 AM CST FRI NOV 20 2015
THE LONG TERM IS EXPECTED TO BE LARGELY QUIET UNTIL THE LAST HALF
OF NEXT WEEK...RIGHT IN TIME FOR THANKSGIVING AND BLACK FRIDAY. IN
FACT...IT COULD BE QUITE A STORMY END TO THE MONTH.
COLD AND DRY AIR WILL FOLLOW IN THE WAKE OF THE DEPARTING
PLAINS/GREAT LAKES LOW SATURDAY. HIGHS WILL ONLY BE IN THE 20S.
INCREASING CLOUDS ARE EXPECTED LATE SATURDAY AND SATURDAY NIGHT AS
A REINFORCING TROUGH DIGS SOUTHEAST FROM THE CANADIAN ROCKIES.
THIS...IN COMBINATION WITH A BACKING SURFACE FLOW TO THE
SOUTHWEST SHOULD KEEP TEMPERATURES FROM DROPPING INTO THE SINGLE
DIGITS OR LOW TEENS...ASIDE FROM PERHAPS THE SNOWY AREAS ALONG
I-90 IF CLOUDS ARE DELAYED A BIT. DID RAISE LOWS A COUPLE DEGREES
IN MOST LOCATIONS BUT THEY MAY STILL BE TOO COLD.
MEANWHILE...AN UPPER JET STREAK WILL ROUND THE CREST OF THE
WESTERN RIDGE SATURDAY NIGHT. AN ACCOMPANYING LOW PRESSURE SYSTEM
POLEWARD THE JET WILL BEGIN DIVING SOUTHEAST TOWARD THE ARROWHEAD
OF MN SUNDAY EVENING WITH A WARM FRONT EXTENDING TO THE SOUTHEAST
ACROSS WESTERN WI. THERE MAY BE ENOUGH LIFT AND MOISTURE TO BRING
SOME LIGHT SNOW SUNDAY NIGHT NEAR AND EAST OF THE WARM FRONT.
ACCUMULATIONS WOULD BE MINIMAL AND THE REST OF THE CWA WOULD BE
DRY SLOTTED.
AS THAT SYSTEM PUSHES EAST...THE RIDGE WILL BUILD EASTWARD ACROSS
THE PLAINS EARLY NEXT WEEK. MILDER TEMPERATURES WILL RETURN...BUT
NOT TO THE DEGREE SEEN FOR MUCH OF THIS MONTH. MORE IMPORTANTLY...
A TROUGH WILL DIG DOWN THE WEST COAST AND A POTENT CLOSED UPPER
LOW WILL STALL OVER NEVADA AND UTAH FOR THE REST OF THE WEEK.
LATEST GUIDANCE IS IN DECENT AGREEMENT AND SUGGESTS THIS CLOSED
LOW WILL EVENTUALLY PHASE WITH THE POLAR JET ACROSS CANADA AND
RESULT IN A LARGE SCALE POSITIVELY TILTED TROUGH/REX
BLOCK...MAKING IT QUITE DIFFICULT TO FULLY EJECT THE ENERGY FROM
THE SOUTHWEST THROUGH THE END OF THE PERIOD. A LONG FEED FROM THE
TROPICAL PACIFIC WILL SET UP IN THE MID/UPPER LEVELS AND TRANSPORT
QUITE A BIT OF MOISTURE INTO THE PLAINS AND UPPER MIDWEST. STRONG
HIGH PRESSURE /1035-1045MB/ OVER THE NORTHERN ROCKIES WILL AT THE
SAME TIME FEED THE NORTHERN/CENTRAL PLAINS AND UPPER MIDWEST WITH
COLD BOUNDARY LAYER AIR BEHIND THE QUASI-STATIONARY SURFACE
BOUNDARY. THE RESULT COULD BE A PROLONGED WINTRY MESS BEGINNING
WEDNESDAY NIGHT AND CONTINUING THROUGH THE REST OF THE WEEK. KEPT
THE GRIDS A SIMPLE RAIN/SNOW MIX AT THIS RANGE...BUT THERMAL
PROFILES OFF THE GFS AND ECMWF WOULD SUPPORT MORE OF A
SNOW/SLEET/FREEZING RAIN SCENARIO...AND GIVEN THE MOISTURE FEED
AVAILABLE...MAJOR IMPACTS COULD RESULT. STAY TUNED.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 548 AM CST FRI NOV 20 2015
VFR CONDITIONS THROUGHOUT. SNOW WILL STAY SOUTH OF THE TAF SITES
TODAY. WINDS WILL BE RELATIVELY LIGHT TODAY...BUT SHOULD INCREASE
LATER TONIGHT WITH GUSTS IN THE MID TEENS POSSIBLE.
KMSP...
VFR CONDITIONS THROUGHOUT. SNOW WILL STAY SOUTH OF MSP TODAY.
WINDS WILL BE RELATIVELY LIGHT TODAY...BUT SHOULD INCREASE LATER
TONIGHT WITH NORTH NORTHWEST GUSTS IN THE MID TEENS EXPECTED.
/OUTLOOK FOR KMSP/
SAT...VFR. WIND NW AT 10G15KT
SUN...VFR. WIND SW AT 10G20KT.
MON...VFR. WIND WNW AT 10G15KT.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 3 AM CST
SATURDAY FOR MNZ091>093.
&&
$$
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...JRB
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
416 AM CST FRI NOV 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM CST FRI NOV 20 2015
WINTER STORM REMAINS ON TRACK TO BRING MODERATE TO HEAVY SNOW ACROSS
NORTHERN IOWA TODAY. THE NORTHERN EDGE OF THIS BAND SHOULD CLIP FAR
SOUTHERN MINNESOTA WITH UP TO 4 INCHES...SO HAVE ISSUED A WINTER
WEATHER ADVISORY BEING THE FIRST SNOWFALL OF THE SEASON. THE SNOW
WILL QUICKLY END TONIGHT...SETTING THE STAGE FOR THE COLDEST NIGHT
OF THE SEASON WITH LOWS IN THE MID TEENS TO LOWER 20S.
THE MODELS HAVE COME INTO BETTER AGREEMENT...AND WITH THE HIRES
SUITE STARTING TO CAPTURE THIS EVENT FEEL FAIRLY CONFIDENT WITH THE
SHORT TERM FORECAST. THE NCAR 10 MEMBER ENSEMBLE DEPICTS THE
UNCERTAINTY BEST...WITH SOME SOLUTIONS SHOWING HARDLY ANY PRECIP
ACROSS SOUTHERN MN...AND OTHERS SHOWING OVER A HALF TO THREE
QUARTERS OF AN INCH. WITH THE ADDITION OF THE HOPWRF AND HRRR FEEL
THAT SOUTHERN MN MAY GET 0.25 TO 0.40 INCHES OF LIQUID...EQUATING TO
2 TO 4 INCHES USING A BLEND OF THE GFS/NAM/AIR FORCE SNOW RATIOS
AT AROUND 10:1 TO 14:1.
A LATENT HEAT VS NON-LATENT HEAT MODEL COMPARISON SHOWS A SOUTHWARD
SHIFT IN THE TRACK FOR THE LATENT HEAT RUN...WHICH RESEMBLES REALITY
MUCH BETTER THAN THE NON-LATENT HEAT RUN...SO THAT IS ANOTHER VOTE
OF CONFIDENCE THAT THE WARNING CRITERIA SNOWFALL WILL STAY TO THE
SOUTH OF THE FORECAST AREA. LOOKING AHEAD...COLD AIR ADVECTION WILL
BRING A REINFORCEMENT OF SEASONABLY COOL AIR ACROSS THE REGION...AND
EXPECT LOW TEMPERATURE NEAR 20 TONIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 416 AM CST FRI NOV 20 2015
THE LONG TERM IS EXPECTED TO BE LARGELY QUIET UNTIL THE LAST HALF
OF NEXT WEEK...RIGHT IN TIME FOR THANKSGIVING AND BLACK FRIDAY. IN
FACT...IT COULD BE QUITE A STORMY END TO THE MONTH.
COLD AND DRY AIR WILL FOLLOW IN THE WAKE OF THE DEPARTING
PLAINS/GREAT LAKES LOW SATURDAY. HIGHS WILL ONLY BE IN THE 20S.
INCREASING CLOUDS ARE EXPECTED LATE SATURDAY AND SATURDAY NIGHT AS
A REINFORCING TROUGH DIGS SOUTHEAST FROM THE CANADIAN ROCKIES.
THIS...IN COMBINATION WITH A BACKING SURFACE FLOW TO THE
SOUTHWEST SHOULD KEEP TEMPERATURES FROM DROPPING INTO THE SINGLE
DIGITS OR LOW TEENS...ASIDE FROM PERHAPS THE SNOWY AREAS ALONG
I-90 IF CLOUDS ARE DELAYED A BIT. DID RAISE LOWS A COUPLE DEGREES
IN MOST LOCATIONS BUT THEY MAY STILL BE TOO COLD.
MEANWHILE...AN UPPER JET STREAK WILL ROUND THE CREST OF THE
WESTERN RIDGE SATURDAY NIGHT. AN ACCOMPANYING LOW PRESSURE SYSTEM
POLEWARD THE JET WILL BEGIN DIVING SOUTHEAST TOWARD THE ARROWHEAD
OF MN SUNDAY EVENING WITH A WARM FRONT EXTENDING TO THE SOUTHEAST
ACROSS WESTERN WI. THERE MAY BE ENOUGH LIFT AND MOISTURE TO BRING
SOME LIGHT SNOW SUNDAY NIGHT NEAR AND EAST OF THE WARM FRONT.
ACCUMULATIONS WOULD BE MINIMAL AND THE REST OF THE CWA WOULD BE
DRY SLOTTED.
AS THAT SYSTEM PUSHES EAST...THE RIDGE WILL BUILD EASTWARD ACROSS
THE PLAINS EARLY NEXT WEEK. MILDER TEMPERATURES WILL RETURN...BUT
NOT TO THE DEGREE SEEN FOR MUCH OF THIS MONTH. MORE IMPORTANTLY...
A TROUGH WILL DIG DOWN THE WEST COAST AND A POTENT CLOSED UPPER
LOW WILL STALL OVER NEVADA AND UTAH FOR THE REST OF THE WEEK.
LATEST GUIDANCE IS IN DECENT AGREEMENT AND SUGGESTS THIS CLOSED
LOW WILL EVENTUALLY PHASE WITH THE POLAR JET ACROSS CANADA AND
RESULT IN A LARGE SCALE POSITIVELY TILTED TROUGH/REX
BLOCK...MAKING IT QUITE DIFFICULT TO FULLY EJECT THE ENERGY FROM
THE SOUTHWEST THROUGH THE END OF THE PERIOD. A LONG FEED FROM THE
TROPICAL PACIFIC WILL SET UP IN THE MID/UPPER LEVELS AND TRANSPORT
QUITE A BIT OF MOISTURE INTO THE PLAINS AND UPPER MIDWEST. STRONG
HIGH PRESSURE /1035-1045MB/ OVER THE NORTHERN ROCKIES WILL AT THE
SAME TIME FEED THE NORTHERN/CENTRAL PLAINS AND UPPER MIDWEST WITH
COLD BOUNDARY LAYER AIR BEHIND THE QUASI-STATIONARY SURFACE
BOUNDARY. THE RESULT COULD BE A PROLONGED WINTRY MESS BEGINNING
WEDNESDAY NIGHT AND CONTINUING THROUGH THE REST OF THE WEEK. KEPT
THE GRIDS A SIMPLE RAIN/SNOW MIX AT THIS RANGE...BUT THERMAL
PROFILES OFF THE GFS AND ECMWF WOULD SUPPORT MORE OF A
SNOW/SLEET/FREEZING RAIN SCENARIO...AND GIVEN THE MOISTURE FEED
AVAILABLE...MAJOR IMPACTS COULD RESULT. STAY TUNED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1210 AM CST FRI NOV 20 2015
VFR CONDITIONS THROUGHOUT. GUSTS SHOULD DECREASE OVERNIGHT...AND
MID LEVEL CLOUDS WILL MOVE IN DURING THE MORNING. SNOW IS EXPECTED
TO STAY SOUTH OF THE AIRPORTS.
KMSP...
VFR CONDITIONS THROUGHOUT. SNOW SHOULD STAY SOUTH OF MSP FRIDAY
EVENING.
/OUTLOOK FOR KMSP/
SAT...VFR. WIND NW 10-15 KTS.
SUN...VFR. WIND SW 10 KTS.
MON...VFR. WIND W 10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 3 AM CST
SATURDAY FOR MNZ091>093.
&&
$$
SHORT TERM...JRB
LONG TERM...BORGHOFF
AVIATION...JRB
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1117 AM CST FRI NOV 20 2015
.SHORT TERM: (Through Saturday night)
Issued at 346 AM CST Fri Nov 20 2015
The primary forecast issues through Saturday are related to an
approaching low pressure system: extent of snowfall late tonight
and tomorrow morning, non-diurnal temperatures on Saturday,
strong winds on Saturday, and cold temperatures on Saturday
night.
The upper vort max which will become the focus for wx over the
next 36hrs was just entering ID/MT at 10z per water vapor imagery
and the RAP analysis of the 1.5 PVU sfc. The vort max dives
southeastward and induces surface cyclogenesis today/tonight, and
the resulting sfc low is then lifted northeastward through
MO/IL/IN in response to the approaching upper disturbance.
The surface low really needs to be farther south for even the
northern parts of the LSX CWA to see any appreciable snowfall.
Since no such southern shift has been observed, at best perhaps a
few to several tenths of an inch of snow might collect on grassy
areas in the far northern CWA after colder air on the back side
of the system deepens sufficiently to change light rain over to a
light rain/snow mix. The ground is still warm and no accumulation
is expected on roads. The best time period for any snowflakes is
after midnight on Fri night and before noon on Sat. No winter
headlines are anticipated attm.
Strong CAA on the back side of the aforementioned low pressure
system yields a non-diurnal temperature trend on Saturday. For
some locations, the daily high temperature might actually occur at
midnight. Strong northwest winds are also expected during the day
on Saturday across most of the area, although neither the
sustained winds nor the wind gusts look high enough for a wind
advisory attm (wind advisory criteria is sustained 30-39 mph for
1+ hours or gusts of 45-57 mph). Regardless, the combination of
falling temperatures, gusty northwest winds, and lingering rain
(possibly mixed with snowflakes) on Saturday won`t exactly make
for a Chamber of Commerce kind of day.
Winds should decrease quickly by late Saturday afternoon or early
Saturday evening. A surface high will be migrating across the
area on Saturday night, and some recent model runs now place the
ridge axis across the CWA at 12z Sun. This is significant because
the mostly clear skies and nearly calm winds could enhance
radiational cooling overnight in what is already a chilly air
mass. Overnight lows in the upper teens to lower 20s still look on
track.
A secondary vort max is still expected to move across the area on
Saturday night, but no additional precipitation is expected.
Depending on how much moisture is present aloft, however,
increased mid/high cloudiness associated with this feature could
interfere with the radiational cooling described above.
Kanofsky
.LONG TERM: (Sunday through Thursday)
Issued at 346 AM CST Fri Nov 20 2015
A strong vort max is forecast to dive out of Canada towards the
Great Lakes on Sunday night into Monday, but so far it appears
that the effects of this system will remain to the north and east
of the LSX CWA.
The models continue to show large disagreement for early next
week. Unlike 24hrs ago, the models now have a lead shortwave
zipping across the southern half of the country early in the week
before a much larger low pressure system organizes over the
western CONUS. There are also large differences between recent
runs and last night`s 00z runs with respect to the evolution of
the large low pressure system. The extended forecast generally
follows the recommended CR initialization due to low run-to-run
continuity and overall lack of model agreement.
Kanofsky
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1051 AM CST Fri Nov 20 2015
VFR ceilings will gradually lower overnight...but still remain in
the low-end VFR range. Light showers will form after around
02Z...but visibilities will remain in the VFR range. a strong cold
front will push through the region between 10 and 14Z...with winds
becoming northwest and increasing to 15 to 18 knots with gusts to
25 knots. Ceilings will fall into the low-end MVFR range behind
the cold front. As temperatures fall rapidly behind the
front...rain will mix with and change to snow at KUIN...and mix
with light snow before ending at KCOU. Visibilities may fall into
low-end MVFR at KUIN after around 12Z. Ceilings will begin to
clear from west to east around 18Z.
Specifics for KSTL: VFR ceilings and visibilities expected
overnight. Light showers are possible after around 04Z. A strong
cold front will move through at around 14Z...with southeast winds
shifting to northwest and increasing to 18 to 18 knots with gusts
to 25 to 28 knots. As the front passes...ceilings will fall into
the low-end MVFR range. Ceilings should begin to clear by 21Z.
Browning
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
618 AM CST FRI NOV 20 2015
.SHORT TERM: (Through Saturday night)
Issued at 346 AM CST Fri Nov 20 2015
The primary forecast issues through Saturday are related to an
approaching low pressure system: extent of snowfall late tonight
and tomorrow morning, non-diurnal temperatures on Saturday,
strong winds on Saturday, and cold temperatures on Saturday
night.
The upper vort max which will become the focus for wx over the
next 36hrs was just entering ID/MT at 10z per water vapor imagery
and the RAP analysis of the 1.5 PVU sfc. The vort max dives
southeastward and induces surface cyclogenesis today/tonight, and
the resulting sfc low is then lifted northeastward through
MO/IL/IN in response to the approaching upper disturbance.
The surface low really needs to be farther south for even the
northern parts of the LSX CWA to see any appreciable snowfall.
Since no such southern shift has been observed, at best perhaps a
few to several tenths of an inch of snow might collect on grassy
areas in the far northern CWA after colder air on the back side
of the system deepens sufficiently to change light rain over to a
light rain/snow mix. The ground is still warm and no accumulation
is expected on roads. The best time period for any snowflakes is
after midnight on Fri night and before noon on Sat. No winter
headlines are anticipated attm.
Strong CAA on the back side of the aforementioned low pressure
system yields a non-diurnal temperature trend on Saturday. For
some locations, the daily high temperature might actually occur at
midnight. Strong northwest winds are also expected during the day
on Saturday across most of the area, although neither the
sustained winds nor the wind gusts look high enough for a wind
advisory attm (wind advisory criteria is sustained 30-39 mph for
1+ hours or gusts of 45-57 mph). Regardless, the combination of
falling temperatures, gusty northwest winds, and lingering rain
(possibly mixed with snowflakes) on Saturday won`t exactly make
for a Chamber of Commerce kind of day.
Winds should decrease quickly by late Saturday afternoon or early
Saturday evening. A surface high will be migrating across the
area on Saturday night, and some recent model runs now place the
ridge axis across the CWA at 12z Sun. This is significant because
the mostly clear skies and nearly calm winds could enhance
radiational cooling overnight in what is already a chilly air
mass. Overnight lows in the upper teens to lower 20s still look on
track.
A secondary vort max is still expected to move across the area on
Saturday night, but no additional precipitation is expected.
Depending on how much moisture is present aloft, however,
increased mid/high cloudiness associated with this feature could
interfere with the radiational cooling described above.
Kanofsky
.LONG TERM: (Sunday through Thursday)
Issued at 346 AM CST Fri Nov 20 2015
A strong vort max is forecast to dive out of Canada towards the
Great Lakes on Sunday night into Monday, but so far it appears
that the effects of this system will remain to the north and east
of the LSX CWA.
The models continue to show large disagreement for early next
week. Unlike 24hrs ago, the models now have a lead shortwave
zipping across the southern half of the country early in the week
before a much larger low pressure system organizes over the
western CONUS. There are also large differences between recent
runs and last night`s 00z runs with respect to the evolution of
the large low pressure system. The extended forecast generally
follows the recommended CR initialization due to low run-to-run
continuity and overall lack of model agreement.
Kanofsky
&&
.AVIATION: (For the 12z TAFs through 12z Saturday Morning)
Issued at 615 AM CST Fri Nov 20 2015
WAA/isentropic ascent will increase across the region as we head
into the afternoon and evening hours as storm system begins to
wind up over the Plains, and all of the guidance is suggesting a
similar "thickening and lowering" cloud trend as the day
progresses. In spite of the initially dry AMS have tried to be
fairly aggressive in bringing a rain threat into the area during
the mid/late afternoon hours because of the intensity of the warm
advection, and have roughly modeled start times on last few HRRR
runs, but ceilings with the onset of the rain should remain fairly
high...aoa 6kft.
Ceilings should continue to slowly drop overnight tonight as WAA
continues to lift and moisten the lower level AMS and generate
precip. Conceptually, with surface low tracking from mid-MO to
north of STL in the 06-12z time frame, ceilings will likely drop
to MVFR at KUIN, with the precip transitioning from rain to snow
sometime around 09z when freezing level finally begins to drop in
this part of the FA. Elsewhere in the "warm sector" of the system,
overnight ceilings are expected to remain in the 3-5kft range,
although expect a rapid drop in ceilings with FROPA at KCOU just
before daybreak.
Specifics for KSTL: A gradual increase in mid clouds is forecast
today. This increase in mid level moisture may produce a bit of
light rain by late in the day, but ceilings will remain above 8000
feet. As mentioned above, the very strong WAA that is progged
across the area tonight should cause the rain threat to ramp up
with a continued...gradual lowering of ceilings, but still expect
bases to remain above 3kft through at least 08z. However, passage
of strong cold front Saturday morning in the 12-15z time frame
will advect MVFR cigs into the area, along with strong northwest
winds that will eventually gust over 30 kts later on Saturday.
Truett
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
427 AM CST FRI NOV 20 2015
.SHORT TERM: (Through Saturday night)
Issued at 346 AM CST Fri Nov 20 2015
The primary forecast issues through Saturday are related to an
approaching low pressure system: extent of snowfall late tonight
and tomorrow morning, non-diurnal temperatures on Saturday,
strong winds on Saturday, and cold temperatures on Saturday
night.
The upper vort max which will become the focus for wx over the
next 36hrs was just entering ID/MT at 10z per water vapor imagery
and the RAP analysis of the 1.5 PVU sfc. The vort max dives
southeastward and induces surface cyclogenesis today/tonight, and
the resulting sfc low is then lifted northeastward through
MO/IL/IN in response to the approaching upper disturbance.
The surface low really needs to be farther south for even the
northern parts of the LSX CWA to see any appreciable snowfall.
Since no such southern shift has been observed, at best perhaps a
few to several tenths of an inch of snow might collect on grassy
areas in the far northern CWA after colder air on the back side
of the system deepens sufficiently to change light rain over to a
light rain/snow mix. The ground is still warm and no accumulation
is expected on roads. The best time period for any snowflakes is
after midnight on Fri night and before noon on Sat. No winter
headlines are anticipated attm.
Strong CAA on the back side of the aforementioned low pressure
system yields a non-diurnal temperature trend on Saturday. For
some locations, the daily high temperature might actually occur at
midnight. Strong northwest winds are also expected during the day
on Saturday across most of the area, although neither the
sustained winds nor the wind gusts look high enough for a wind
advisory attm (wind advisory criteria is sustained 30-39 mph for
1+ hours or gusts of 45-57 mph). Regardless, the combination of
falling temperatures, gusty northwest winds, and lingering rain
(possibly mixed with snowflakes) on Saturday won`t exactly make
for a Chamber of Commerce kind of day.
Winds should decrease quickly by late Saturday afternoon or early
Saturday evening. A surface high will be migrating across the
area on Saturday night, and some recent model runs now place the
ridge axis across the CWA at 12z Sun. This is significant because
the mostly clear skies and nearly calm winds could enhance
radiational cooling overnight in what is already a chilly air
mass. Overnight lows in the upper teens to lower 20s still look on
track.
A secondary vort max is still expected to move across the area on
Saturday night, but no additional precipitation is expected.
Depending on how much moisture is present aloft, however,
increased mid/high cloudiness associated with this feature could
interfere with the radiational cooling described above.
Kanofsky
.LONG TERM: (Sunday through Thursday)
Issued at 346 AM CST Fri Nov 20 2015
A strong vort max is forecast to dive out of Canada towards the
Great Lakes on Sunday night into Monday, but so far it appears
that the effects of this system will remain to the north and east
of the LSX CWA.
The models continue to show large disagreement for early next
week. Unlike 24hrs ago, the models now have a lead shortwave
zipping across the southern half of the country early in the week
before a much larger low pressure system organizes over the
western CONUS. There are also large differences between recent
runs and last night`s 00z runs with respect to the evolution of
the large low pressure system. The extended forecast generally
follows the recommended CR initialization due to low run-to-run
continuity and overall lack of model agreement.
Kanofsky
&&
.AVIATION: (For the 06z TAFs through 06z Friday Night)
Issued at 1145 PM CST Thu Nov 19 2015
VFR conditions will prevail at the TAF sites thru much of the
valid period. Look for clouds to increase later tonight with
gradually lowering CIGs thru the day on Friday, likely attaining
MVFR CIGs at UIN by 06z/Sat, and COU just beyond the end of the
valid period. Light rain should also rapidly close in on UIN and
COU heading towards sunset Friday evening with STL metro sites
being affected later that evening. In the meantime, look for
light surface winds becoming SE later tonight, then gusty at times
Friday, with a sharp veer and strengthening from the W-NW with
cold FROPA just beyond the valid period.
Specifics for KSTL: VFR thru much of the valid period with clouds
increasing late, then gradually lowering thru the day on Friday
and into the evening. Rain looks to be a bit faster moving in
during the evening but should be light when it does. Light winds
will become SE late tonight, then gusty towards midday Friday and
into the evening. Look for a sharp veer and strengthening from
the W-NW late Friday night with cold FROPA, along with
introduction of MVFR CIGs but should also signal and end to the
rain.
TES
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
949 AM MST FRI NOV 20 2015
.UPDATE...
THE GOING FORECAST LOOKS ON TRACK. THE SHORTWAVE TROUGH CONTINUES
TO QUICK MOVE INTO SOUTHERN MONTANA. THE HRRR CONTINUES TO SHOW
CONVECTIVE BANDING THROUGH THIS AFTERNOON...WHICH IS LINING UP
WELL WITH CURRENT RADAR. NO CHANGES MADE. REIMER
&&
.SHORT TERM...VALID FOR TDY AND SAT...
THE FIRST SNOWFALL OF THE SEASON FOR THE BILLINGS AREA IS
CURRENTLY UNDERWAY. AN UNSTABLE NORTHWEST FLOW ALOFT WILL CONTINUE
ACROSS THE FORECAST AREA TODAY. A DISTURBANCE ACROSS SOUTHERN
CANADA WILL MOVE SOUTHEAST ACROSS THE CENTRAL AND SOUTHERN
PORTIONS OF THE STATE. IR SATELLITE IS CURRENTLY SHOWING COLDER
CLOUD TOPS UPSTREAM HEADING SOUTHEAST TOWARD OUR FORECAST AREA.
LIGHT SNOW HAS BEEN FALLING THE PAST HOUR HERE IN BILLINGS. RADAR
OVERNIGHT HAS CONTINUED TO SHOW LIGHT SNOW ACROSS OUR WESTERN
COUNTIES BUT THE LATEST OBSERVATION IN LIVINGSTON HAS REPORTED THE
SNOW HAS STOPPED. HOWEVER...THE SNOW SHOULD START AGAIN AS THIS
NEXT DISTURBANCE MOVES ACROSS THE AREA.
MODELS SHOW THE POSSIBILITY OF SNOW BANDING ALONG AND WEST OF A
SHERIDAN- BILLINGS-ROUNDUP LINE. LAPSE RATES ARE STEEP ON THE
ORDER OF 7-8C/KM. CONFIDENCE IS LOW FOR ADVISORY CRITERIA BEING
MET FOR BILLINGS BUT CAN`T RULE OUT AN ISOLATED 2 TO 3 INCH REPORT
ACROSS SOUTHERN YELLOWSTONE COUNTY. HOWEVER..GIVEN A NORTHWEST
SURFACE FLOW...CONFIDENCE IS HIGHER FOR ADVISORY AMOUNTS ACROSS
SOUTHERN BIG HORN COUNTY HAS THE NORTHWEST SURFACE FLOW WILL
PROVIDE FOR AN UPSLOPE COMPONENT. AS A RESULT...I HAVE ADDED
SOUTHERN BIG HORN COUNTY INTO AN ADVISORY FOR THE REMAINDER OF THE
DAY. MODEL GUIDANCE SHOWS SOME GUSTY NORTHWEST WINDS LATER THIS
MORNING FOR THE SHERIDAN AREA AND THIS MAY DOWNSLOPE INTO SHERIDAN
KEEPING SNOW AMOUNTS LIGHTER SO I WILL LEAVE THEM OUT OF THE
ADVISORY FOR NOW. WE WE WILL CONTINUE TO WATCH HOW THE SNOW
EVOLVES FOR YELLOWSTONE AND SHERIDAN COUNTIES FOR ANY POSSIBLE
ADVISORIES LATER THIS MORNING.
A DRY AND MORE STABLE NORTHWEST FLOW ALOFT WILL BE OVER THE
FORECAST ARE TONIGHT THROUGH SATURDAY NIGHT. TEMPERATURES WILL BE
COLD TODAY WITH HIGHS ONLY IN THE UPPER 20S TO LOWER 30S. SOME
CLEARING TONIGHT COMBINED WITH ANY SNOW COVER WILL ALLOW
TEMPERATURES TO FALL WELL INTO THE TEENS AND POSSIBLY SINGLE
DIGITS. HIGHS SATURDAY WILL BE A BIT WARMER BUT WILL WELL BELOW
NORMAL. HOOLEY
.LONG TERM...VALID FOR SUN...MON...TUE...WED...THU...
VERY INTERESTING WX PATTERN NEXT WEEK...WITH WHAT MAY BE OUR FIRST
REAL BLAST OF WINTER BY WEDNESDAY/THURSDAY. ANYONE WITH
THANKSGIVING TRAVEL PLANS WILL NEED TO MONITOR THE FORECAST
CLOSELY.
FOR SUNDAY AND MONDAY...DOWNSLOPE GRADIENTS WILL PREVAIL UNDER
FLAT RIDGING ALOFT. THIS WILL ALLOW FOR BREEZY CONDITIONS AND
GENERALLY WARMER THAN NORMAL TEMPS WITH HIGHS IN THE 40S TO
PUSHING 50F. STRONGEST WINDS WILL OF COURSE BE ALONG OUR WESTERN
FOOTHILLS. DO NOT SEE QUITE ENOUGH GRADIENT OR MID LEVEL FLOW TO
SUPPORT ADVISORY CRITERIA...BUT WILL HAVE TO KEEP AN EYE ON THE
PRE-FRONTAL PERIOD MONDAY-MONDAY NIGHT AS THIS WILL BE THE FAVORED
TIME.
A SHORTWAVE CURRENTLY IN EASTERN SIBERIA WILL MOVE OVER THE GULF
OF AK...DOWN THE CANADIAN WEST COAST...AND CARVE OUT A LOW OVER
THE NW STATES BY TUESDAY. THE COMBINATION OF ASCENT ASSOCIATED
WITH THIS LOW AND A CANADIAN COLD FRONT WILL BRING OUR ENTIRE
REGION A GOOD CHANCE OF ACCUMULATING SNOW TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT. LATEST MODELS HAVE ACTUALLY TRENDED A BIT EAST
WITH THE UPPER LOW AND SUGGEST A MORE FAVORABLE TRACK FOR PCPN IN
OUR AREA...WITH UPSLOPE FLOW THRU MID LEVELS AS A LEE SIDE COLD
AIRMASS DEEPENS. MUST STRESS THE UNCERTAINTY HERE AS A DEVIATION
IN THE TRACK OF THE LOW AND A QUICKER DRYING FROM THE NW WOULD
NEGATIVELY AFFECT OUR PCPN CHANCES...AS THE LOW IS EXPECTED TO
PUSH INTO THE GREAT BASIN OVER TIME. HAVE CAUTIOUSLY RAISED POPS A
NOTCH WITH TUESDAY NIGHT THROUGH WEDNESDAY NIGHT APPEARING TO BE
THE MOST FAVORED PERIODS. MODEL SPREAD INCREASES BY THURSDAY AS WE
SHOULD EVENTUALLY SEE DRYING FROM NW WITH PASSAGE OF NORTHERN
BRANCH SHORTWAVE...IE DECREASING POPS BY THANKSGIVING DAY.
GFS/ECMWF SUGGEST FORMATION OF A REX BLOCK BY THE END OF NEXT
WEEK...WITH STRONG RIDGING OVER THE CANADIAN ROCKIES AS THE UPPER
LOW CUTS OFF SOMEWHERE OVER THE SW CONUS. THIS WOULD KEEP A SFC
RIDGE AND SLOW-TO-EXIT COLD AIR IN OUR CWA INTO NEXT WEEKEND.
SOMETHING TO KEEP AN EYE ON.
AS FOR TEMPERATURES...AFTER THE AFOREMENTIONED MILD DAYS ON
SUNDAY AND MONDAY...WE WILL BEGIN TO TURN COLDER TUESDAY OR
TUESDAY NIGHT WITH PASSAGE OF A STRONG CANADIAN COLD FRONT.
WEDNESDAY AND THURSDAY WILL ALMOST CERTAINLY BE THE COLDEST DAYS
WE HAVE SEEN YET THIS FALL. GFS/ECMWF/CANADIAN SHOW 850MB TEMPS ON
THE ORDER OF -15C BY 144 HRS...AND THIS IS SUPPORTED BY THE GFS
ENSEMBLE MEAN AS WELL...SO THERE IS CONFIDENCE IN LOWERING
FORECAST TEMPS FOR MIDWEEK. HIGHS IN THE TEENS TO LOW 20S AND LOWS
IN THE SINGLE DIGITS ARE A GOOD FIRST GUESS BUT THESE WILL BE TOO
WARM IF THE LATEST MODEL TRENDS VERIFY...ESPECIALLY IF THERE IS A
SIGNIFICANT SNOW COVER.
JKL
&&
.AVIATION...
SNOW SHOWERS WITH PERIODIC REDUCTIONS TO IFR CONDITIONS WILL
PERSIST UNTIL 19Z. IMPROVING CONDITIONS EXPECTED LATE AFTERNOON
WITH VFR OVERNIGHT. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY SAT SUN MON TUE WED THU
-------------------------------------------------------
BIL 030 016/037 026/047 027/048 030/043 019/022 009/019
8/S 10/N 00/N 00/U 01/B 55/S 53/S
LVM 028 013/037 026/043 026/045 028/040 018/019 008/019
8/S 10/N 00/N 00/N 13/O 55/S 43/S
HDN 031 010/037 017/047 022/048 024/045 021/025 010/020
8/S 10/B 00/U 00/U 01/B 35/S 43/S
MLS 028 013/036 017/048 022/047 025/042 022/026 011/022
2/S 10/B 00/U 00/B 01/B 34/S 43/S
4BQ 029 009/036 017/050 022/050 024/046 022/029 012/022
4/S 10/B 00/U 00/U 00/B 25/S 43/S
BHK 025 008/034 015/046 022/045 022/042 022/027 011/022
1/E 10/B 00/B 00/B 00/B 24/S 43/S
SHR 028 005/038 015/048 022/050 023/046 021/027 010/021
8/S 10/B 00/U 00/U 00/B 25/S 54/S
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MST THIS EVENING
FOR ZONES 34-38-40-41-56-64>66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1252 PM CST FRI NOV 20 2015
.UPDATE...
ISSUED AT 1240 PM CST FRI NOV 20 2015
NOON SURFACE TEMPERATURES WERE ALREADY NEARING MAX TEMPERATURES IN
SOME LOCALES. WITH WEAK COLD ADVECTION CONTINUING THIS AFTERNOON
DON`T THINK TEMPERATURES WILL CLIMB MUCH...BUT WITH NEARLY FULL
SUN MANY AREAS AND NO SNOW COVER...DID BUMP UP TEMPS A FEW PLACES.
ALSO LOWERED SKY COVER IN THE SOUTHWEST EARLY THIS AFTERNOON.
UPDATE ISSUED AT 943 AM CST FRI NOV 20 2015
MADE SOME MINOR ADJUSTMENTS TO SKY COVER AND POPS. OTHERWISE NO
SIGNIFICANT UPDATES TO THE GOING FORECAST. LATEST BOWMAN RADAR
INDICATES SOME LIGHT REFLECTIVITIES TRACKING SOUTHEAST ACROSS
BOWMAN/SLOPE COUNTIES...AND A BRIEF SNOW SHOWER INDICATED AT
BAKER MT SO WILL KEEP A MENTION OF SNOW IN THE FAR SOUTHWEST. THIS
WAS TRIMMED BACK EVEN MORE FROM OUR PREVIOUS FORECAST.
UPDATE ISSUED AT 630 AM CST FRI NOV 20 2015
NO CHANGES OF SIGNIFICANCE WERE MADE WITH THIS UPDATE AS WE ONLY
BLENDED CURRENT OBSERVATIONS WITH RECENT SHORT-RANGE MODEL OUTPUT.
WE HAVE RETAINED A LOW-END CHANCE OF LIGHT SNOW IN FAR SOUTHWEST
ND THROUGH EARLY AFTERNOON...BUT NEITHER UPSTREAM OBSERVATIONS IN
MT NOR RECENT HRRR SIMULATIONS ARE SUGGESTIVE OF MUCH POTENTIAL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST FRI NOV 20 2015
A WEAK HIGH PRESSURE RIDGE AXIS EXTENDED FROM SOUTHERN
SASKATCHEWAN SOUTHEASTWARD ACROSS NORTHWESTERN NORTH DAKOTA
THROUGH SOUTH CENTRAL NORTH DAKOTA. THIS RIDGE WAS BETWEEN A
STRONG LOW PRESSURE SYSTEM OVER HUDSON BAY AND ANOTHER LOW OVER
WYOMING. AT UPPER LEVELS...A DEEP UPPER LEVEL LOW WAS OVER HUDSON
BAY...WITH A SECONDARY TROUGH OVER THE NORTHERN ROCKIES AND FRONT
RANGE.
MID LEVEL CLOUD COVER ASSOCIATED WITH THE UPPER LEVEL TROUGH
EXTENDED FROM ALBERTA SOUTHEASTWARD TO SOUTH DAKOTA/NEBRASKA. THE
LOW OVER WYOMING AND UPPER LEVEL TROUGH WAS ASSOCIATED WITH LIGHT
SNOW AND LOWER CLOUDS MAINLY SOUTH AND WEST OF NORTH DAKOTA...BUT
ADDED A MENTION OF A SLIGHT CHANCE OF LIGHT SNOW IN THE FAR
SOUTHWEST THIS MORNING. BOWMAN RADAR INDICATING POSSIBLE LIGHT SNOW
REACHING THE GROUND WITH LIGHT RADAR RETURNS IN THE FAR
SOUTHWEST...MAINLY ALONG AND SOUTH OF HIGHWAY 12. OTHERWISE MID LEVEL
CLOUDS WERE OVER PARTS OF WESTERN AND CENTRAL NORTH DAKOTA...AND
WILL LIKELY CONTINUE TO BRING SOME PARTLY CLOUDY SKIES TO
NORTH DAKOTA. ALSO...A COLD FRONT MOVING SOUTHEAST OUT OF
SASKATCHEWAN IS EXPECTED TO ENTER NORTHWESTERN NORTH DAKOTA
BY DAYBREAK...WITH SOME LOWER LEVEL CLOUDS. THUS A PARTLY TO MOSTLY
CLOUDY DAY EXPECTED. ANOTHER COOL DAY WITH HIGHS FROM 20 TO 30.
ANOTHER COOL NIGHT TONIGHT AS WELL WITH PARTLY TO MOSTLY CLOUDY
SKIES. SOME WARM ADVECTION MAY BEGIN IN THE WEST LATE FRIDAY
NIGHT...BUT STILL EXPECT OVERNIGHT LOWS TO RANGE FROM 5 TO 15.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CST FRI NOV 20 2015
HIGHLIGHTS IN THE LONG TERM INCLUDE GUSTY WINDS SUNDAY AND THE
POSSIBILITY OF WINTER WEATHER IMPACTING THANKSGIVING TRAVEL.
A FEW WEAK AND MOISTURE-STARVED IMPULSES EMBEDDED IN NORTHWEST
FLOW ALOFT WILL CROSS THE REGION THIS WEEKEND. THE 00 UTC MODEL
GUIDANCE CALLS FOR 850-MB WINDS OF 45 TO 55 KT DEVELOPING ACROSS
THE AREA SUNDAY INTO SUNDAY EVENING AS A WEAK CLIPPER-TYPE LOW
TRACKS ACROSS CENTRAL CANADA. THE EFFICIENCY OF MOMENTUM TRANSFER
IS IN QUESTION GIVEN A LACK OF ROBUST COLD AIR ADVECTION...SO WE
ARE NOT CONFIDENT IN HEADLINE-WORTHY GUSTS...BUT IT WILL LIKELY BE
A WINDY DAY REGARDLESS. A BRIEF WARM-UP IS STILL EXPECTED SUNDAY
INTO MONDAY WITH FORECAST HIGHS FROM THE MID 30S TO THE MID 40S F.
BY NEXT WEDNESDAY AND THURSDAY...A DEEP 500-MB LOW IS FORECAST TO
DIG INTO THE GREAT BASIN...AND THAT COULD YIELD SNOWFALL OVER THE
REGION. HOWEVER...THE 00 UTC MODEL SUITE GENERALLY TRENDED FURTHER
SOUTH WITH THE PRIMARY DYNAMIC FORCING THAT REACHES THE PLAINS AND
THUS IT SUGGESTED LOWER SNOWFALL TOTALS IN WESTERN AND CENTRAL ND
THAN PREVIOUS MODEL CYCLES. THUS...CONFIDENCE IN POSSIBLE IMPACTS
TO THANKSGIVING TRAVEL IS NOT VERY HIGH. A SEVEN MEMBER...TIME-
LAGGED ENSEMBLE OF DETERMINISTIC GFS RUNS ALSO YIELDED LESS THAN A
30 PERCENT PROBABILITY OF 0.10 INCHES OR MORE OF LIQUID-EQUIVALENT
PRECIPITATION WEDNESDAY THROUGH THANKSGIVING...FURTHER SUGGESTIVE
OF A LACK OF RUN-TO-RUN MODEL CONSENSUS ON DETAILS OF THE PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1240 PM CST FRI NOV 20 2015
VFR CONDITIONS IN A LIGHT NORTHERLY SURFACE FLOW TODAY AND THIS
EVENING. FLOW BECOMES MORE WESTERLY LATE TONIGHT AND SATURDAY AS A
WARM FRONT APPROACHES FROM THE WEST. THIS WILL ALSO BRING A BAND
OF CLOUDS INTO WESTERN AND CENTRAL NORTH DAKOTA ON SATURDAY.
EXPECT MAINLY LOWER VFR CLOUDS...BUT SCATTERED MVFR CLOUDS CAN NOT
BE RULED OUT.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...CJS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
949 AM CST FRI NOV 20 2015
.UPDATE...
ISSUED AT 943 AM CST FRI NOV 20 2015
MADE SOME MINOR ADJUSTMENTS TO SKY COVER AND POPS. OTHERWISE NO
SIGNIFICANT UPDATES TO THE GOING FORECAST. LATEST BOWMAN RADAR
INDICATES SOME LIGHT REFLECTIVITIES TRACKING SOUTHEAST ACROSS
BOWMAN/SLOPE COUNTIES...AND A BRIEF SNOW SHOWER INDICATED AT
BAKER MT SO WILL KEEP A MENTION OF SNOW IN THE FAR SOUTHWEST. THIS
WAS TRIMMED BACK EVEN MORE FROM OUR PREVIOUS FORECAST.
UPDATE ISSUED AT 630 AM CST FRI NOV 20 2015
NO CHANGES OF SIGNIFICANCE WERE MADE WITH THIS UPDATE AS WE ONLY
BLENDED CURRENT OBSERVATIONS WITH RECENT SHORT-RANGE MODEL OUTPUT.
WE HAVE RETAINED A LOW-END CHANCE OF LIGHT SNOW IN FAR SOUTHWEST
ND THROUGH EARLY AFTERNOON...BUT NEITHER UPSTREAM OBSERVATIONS IN
MT NOR RECENT HRRR SIMULATIONS ARE SUGGESTIVE OF MUCH POTENTIAL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST FRI NOV 20 2015
A WEAK HIGH PRESSURE RIDGE AXIS EXTENDED FROM SOUTHERN
SASKATCHEWAN SOUTHEASTWARD ACROSS NORTHWESTERN NORTH DAKOTA
THROUGH SOUTH CENTRAL NORTH DAKOTA. THIS RIDGE WAS BETWEEN A
STRONG LOW PRESSURE SYSTEM OVER HUDSON BAY AND ANOTHER LOW OVER
WYOMING. AT UPPER LEVELS...A DEEP UPPER LEVEL LOW WAS OVER HUDSON
BAY...WITH A SECONDARY TROUGH OVER THE NORTHERN ROCKIES AND FRONT
RANGE.
MID LEVEL CLOUD COVER ASSOCIATED WITH THE UPPER LEVEL TROUGH
EXTENDED FROM ALBERTA SOUTHEASTWARD TO SOUTH DAKOTA/NEBRASKA. THE
LOW OVER WYOMING AND UPPER LEVEL TROUGH WAS ASSOCIATED WITH LIGHT
SNOW AND LOWER CLOUDS MAINLY SOUTH AND WEST OF NORTH DAKOTA...BUT
ADDED A MENTION OF A SLIGHT CHANCE OF LIGHT SNOW IN THE FAR
SOUTHWEST THIS MORNING. BOWMAN RADAR INDICATING POSSIBLE LIGHT SNOW
REACHING THE GROUND WITH LIGHT RADAR RETURNS IN THE FAR
SOUTHWEST...MAINLY ALONG AND SOUTH OF HIGHWAY 12. OTHERWISE MID LEVEL
CLOUDS WERE OVER PARTS OF WESTERN AND CENTRAL NORTH DAKOTA...AND
WILL LIKELY CONTINUE TO BRING SOME PARTLY CLOUDY SKIES TO
NORTH DAKOTA. ALSO...A COLD FRONT MOVING SOUTHEAST OUT OF
SASKATCHEWAN IS EXPECTED TO ENTER NORTHWESTERN NORTH DAKOTA
BY DAYBREAK...WITH SOME LOWER LEVEL CLOUDS. THUS A PARTLY TO MOSTLY
CLOUDY DAY EXPECTED. ANOTHER COOL DAY WITH HIGHS FROM 20 TO 30.
ANOTHER COOL NIGHT TONIGHT AS WELL WITH PARTLY TO MOSTLY CLOUDY
SKIES. SOME WARM ADVECTION MAY BEGIN IN THE WEST LATE FRIDAY
NIGHT...BUT STILL EXPECT OVERNIGHT LOWS TO RANGE FROM 5 TO 15.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CST FRI NOV 20 2015
HIGHLIGHTS IN THE LONG TERM INCLUDE GUSTY WINDS SUNDAY AND THE
POSSIBILITY OF WINTER WEATHER IMPACTING THANKSGIVING TRAVEL.
A FEW WEAK AND MOISTURE-STARVED IMPULSES EMBEDDED IN NORTHWEST
FLOW ALOFT WILL CROSS THE REGION THIS WEEKEND. THE 00 UTC MODEL
GUIDANCE CALLS FOR 850-MB WINDS OF 45 TO 55 KT DEVELOPING ACROSS
THE AREA SUNDAY INTO SUNDAY EVENING AS A WEAK CLIPPER-TYPE LOW
TRACKS ACROSS CENTRAL CANADA. THE EFFICIENCY OF MOMENTUM TRANSFER
IS IN QUESTION GIVEN A LACK OF ROBUST COLD AIR ADVECTION...SO WE
ARE NOT CONFIDENT IN HEADLINE-WORTHY GUSTS...BUT IT WILL LIKELY BE
A WINDY DAY REGARDLESS. A BRIEF WARM-UP IS STILL EXPECTED SUNDAY
INTO MONDAY WITH FORECAST HIGHS FROM THE MID 30S TO THE MID 40S F.
BY NEXT WEDNESDAY AND THURSDAY...A DEEP 500-MB LOW IS FORECAST TO
DIG INTO THE GREAT BASIN...AND THAT COULD YIELD SNOWFALL OVER THE
REGION. HOWEVER...THE 00 UTC MODEL SUITE GENERALLY TRENDED FURTHER
SOUTH WITH THE PRIMARY DYNAMIC FORCING THAT REACHES THE PLAINS AND
THUS IT SUGGESTED LOWER SNOWFALL TOTALS IN WESTERN AND CENTRAL ND
THAN PREVIOUS MODEL CYCLES. THUS...CONFIDENCE IN POSSIBLE IMPACTS
TO THANKSGIVING TRAVEL IS NOT VERY HIGH. A SEVEN MEMBER...TIME-
LAGGED ENSEMBLE OF DETERMINISTIC GFS RUNS ALSO YIELDED LESS THAN A
30 PERCENT PROBABILITY OF 0.10 INCHES OR MORE OF LIQUID-EQUIVALENT
PRECIPITATION WEDNESDAY THROUGH THANKSGIVING...FURTHER SUGGESTIVE
OF A LACK OF RUN-TO-RUN MODEL CONSENSUS ON DETAILS OF THE PATTERN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 943 AM CST FRI NOV 20 2015
SURFACE HIGH PRESSURE WAS OVER NORTH DAKOTA WITH LOW PRESSURE OVER
WYOMING AND LOW PRESSURE OVER HUDSON BAY. A TROUGH OF LOW PRESSURE
WILL SPREAD CLOUDS LOW VFR CONDITIONS INTO KISN AND KMOT AROUND
15Z AND SCT TO BKN CLOUDS AT KBIS/KDIK/KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...TWH
SHORT TERM...JV
LONG TERM...CJS
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
634 AM CST FRI NOV 20 2015
.UPDATE...
ISSUED AT 630 AM CST FRI NOV 20 2015
NO CHANGES OF SIGNIFICANCE WERE MADE WITH THIS UPDATE AS WE ONLY
BLENDED CURRENT OBSERVATIONS WITH RECENT SHORT-RANGE MODEL OUTPUT.
WE HAVE RETAINED A LOW-END CHANCE OF LIGHT SNOW IN FAR SOUTHWEST
ND THROUGH EARLY AFTERNOON...BUT NEITHER UPSTREAM OBSERVATIONS IN
MT NOR RECENT HRRR SIMULATIONS ARE SUGGESTIVE OF MUCH POTENTIAL.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 340 AM CST FRI NOV 20 2015
A WEAK HIGH PRESSURE RIDGE AXIS EXTENDED FROM SOUTHERN
SASKATCHEWAN SOUTHEASTWARD ACROSS NORTHWESTERN NORTH DAKOTA
THROUGH SOUTH CENTRAL NORTH DAKOTA. THIS RIDGE WAS BETWEEN A
STRONG LOW PRESSURE SYSTEM OVER HUDSON BAY AND ANOTHER LOW OVER
WYOMING. AT UPPER LEVELS...A DEEP UPPER LEVEL LOW WAS OVER HUDSON
BAY...WITH A SECONDARY TROUGH OVER THE NORTHERN ROCKIES AND FRONT
RANGE.
MID LEVEL CLOUD COVER ASSOCIATED WITH THE UPPER LEVEL TROUGH
EXTENDED FROM ALBERTA SOUTHEASTWARD TO SOUTH DAKOTA/NEBRASKA. THE
LOW OVER WYOMING AND UPPER LEVEL TROUGH WAS ASSOCIATED WITH LIGHT
SNOW AND LOWER CLOUDS MAINLY SOUTH AND WEST OF NORTH DAKOTA...BUT
ADDED A MENTION OF A SLIGHT CHANCE OF LIGHT SNOW IN THE FAR
SOUTHWEST THIS MORNING. BOWMAN RADAR INDICATING POSSIBLE LIGHT SNOW
REACHING THE GROUND WITH LIGHT RADAR RETURNS IN THE FAR
SOUTHWEST...MAINLY ALONG AND SOUTH OF HIGHWAY 12. OTHERWISE MID LEVEL
CLOUDS WERE OVER PARTS OF WESTERN AND CENTRAL NORTH DAKOTA...AND
WILL LIKELY CONTINUE TO BRING SOME PARTLY CLOUDY SKIES TO
NORTH DAKOTA. ALSO...A COLD FRONT MOVING SOUTHEAST OUT OF
SASKATCHEWAN IS EXPECTED TO ENTER NORTHWESTERN NORTH DAKOTA
BY DAYBREAK...WITH SOME LOWER LEVEL CLOUDS. THUS A PARTLY TO MOSTLY
CLOUDY DAY EXPECTED. ANOTHER COOL DAY WITH HIGHS FROM 20 TO 30.
ANOTHER COOL NIGHT TONIGHT AS WELL WITH PARTLY TO MOSTLY CLOUDY
SKIES. SOME WARM ADVECTION MAY BEGIN IN THE WEST LATE FRIDAY
NIGHT...BUT STILL EXPECT OVERNIGHT LOWS TO RANGE FROM 5 TO 15.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 340 AM CST FRI NOV 20 2015
HIGHLIGHTS IN THE LONG TERM INCLUDE GUSTY WINDS SUNDAY AND THE
POSSIBILITY OF WINTER WEATHER IMPACTING THANKSGIVING TRAVEL.
A FEW WEAK AND MOISTURE-STARVED IMPULSES EMBEDDED IN NORTHWEST
FLOW ALOFT WILL CROSS THE REGION THIS WEEKEND. THE 00 UTC MODEL
GUIDANCE CALLS FOR 850-MB WINDS OF 45 TO 55 KT DEVELOPING ACROSS
THE AREA SUNDAY INTO SUNDAY EVENING AS A WEAK CLIPPER-TYPE LOW
TRACKS ACROSS CENTRAL CANADA. THE EFFICIENCY OF MOMENTUM TRANSFER
IS IN QUESTION GIVEN A LACK OF ROBUST COLD AIR ADVECTION...SO WE
ARE NOT CONFIDENT IN HEADLINE-WORTHY GUSTS...BUT IT WILL LIKELY BE
A WINDY DAY REGARDLESS. A BRIEF WARM-UP IS STILL EXPECTED SUNDAY
INTO MONDAY WITH FORECAST HIGHS FROM THE MID 30S TO THE MID 40S F.
BY NEXT WEDNESDAY AND THURSDAY...A DEEP 500-MB LOW IS FORECAST TO
DIG INTO THE GREAT BASIN...AND THAT COULD YIELD SNOWFALL OVER THE
REGION. HOWEVER...THE 00 UTC MODEL SUITE GENERALLY TRENDED FURTHER
SOUTH WITH THE PRIMARY DYNAMIC FORCING THAT REACHES THE PLAINS AND
THUS IT SUGGESTED LOWER SNOWFALL TOTALS IN WESTERN AND CENTRAL ND
THAN PREVIOUS MODEL CYCLES. THUS...CONFIDENCE IN POSSIBLE IMPACTS
TO THANKSGIVING TRAVEL IS NOT VERY HIGH. A SEVEN MEMBER...TIME-
LAGGED ENSEMBLE OF DETERMINISTIC GFS RUNS ALSO YIELDED LESS THAN A
30 PERCENT PROBABILITY OF 0.10 INCHES OR MORE OF LIQUID-EQUIVALENT
PRECIPITATION WEDNESDAY THROUGH THANKSGIVING...FURTHER SUGGESTIVE
OF A LACK OF RUN-TO-RUN MODEL CONSENSUS ON DETAILS OF THE PATTERN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 630 AM CST FRI NOV 20 2015
SURFACE HIGH PRESSURE WAS OVER NORTH DAKOTA WITH LOW PRESSURE OVER
WYOMING AND LOW PRESSURE OVER HUDSON BAY. A TROUGH OF LOW PRESSURE
WILL SPREAD CLOUDS AND MVFR TO LOW VFR CONDITIONS INTO KISN AND KMOT
AROUND 15Z AND SCT TO BKN CLOUDS AT KBIS/KDIK/KJMS.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...CJS
SHORT TERM...JV
LONG TERM...CJS
AVIATION...JV
AREA FORECAST DISCUSSION
NWS CLEVELAND OH
647 PM EST SAT NOV 21 2015
.SYNOPSIS...
LOW PRESSURE OVER NORTHERN OHIO WILL TRACK NORTHEAST INTO QUEBEC ON
SUNDAY PULLING A STRONG COLD FRONT EAST ACROSS THE AREA. HIGH
PRESSURE WILL BUILD OVER THE OHIO VALLEY ON SUNDAY...THEN SHIFT TO
THE EAST COAST ON MONDAY. ANOTHER LOW PRESSURE SYSTEM WILL SLIDE
EAST ACROSS THE UPPER GREAT LAKES ON MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
BAND OF SHOWERS WITH SOME GRAUPEL MIXED IN ON THE WESTERN EDGE
PUSHING EAST AT THIS TIME ACROSS EASTERN OHIO AND NORTHWEST
PENNSYLVANIA. THE LATEST HRRR MODEL INDICATES BAND WILL GRADUALLY
NARROW AS IT MOVES INTO MUCH DRIER AIR.
TO THE WEST...THE BULK OF THE PRECIPITATION HAS MOVED EAST AND OUT
OF THE AREA AT THIS TIME. AS THE LOW PRESSURE SYSTEM MOVES
EAST...WRAP AROUND MOISTURE AND ASSOCIATED PRECIPITATION WILL
ADVANCE EAST INTO NORTHWEST OHIO. DECIDED TO LEAVE A MENTION OF UP
TO AN INCH SNOW ACCUMULATION OVERNIGHT WITH THE WRAP AROUND. WILL
DO SOME CLEAN UP FOR SNOW ACCUMS LATER THIS EVENING AS ACTIVITY
PULLS OUT.
WE ARE MONITORING LATEST MODELS AS THEY COME IN TO MAKE A DECISION
ON WHETHER TO KEEP THE LAKE EFFECT SNOW WATCH OR DROP IT. CURRENT
TRENDS POINTING TOWARD LAKE EFFECT NOT BEING ABLE TO PRODUCE
ENOUGH SNOW TO WARRANT A WARNING OR KEEPING THE WATCH. WILL WAIT
TO SEE WHAT NEW MODELS FROM 00Z RUN INDICATE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY NIGHT/...
LAKE EFFECT WATCHES REMAIN IN EFFECT THROUGH SUNDAY NIGHT...7AM
MONDAY MORNING FOR ASHTABULA/ERIE/CRAWFORD COUNTIES. NOT A CLEAR CUT
LAKE EFFECT EVENT WITH VERY DRY MID-LEVEL AIR SPREADING OVER THE
LAKE AND ATTEMPTING TO LIMIT CLOUD DEPTH. WITH THAT SAID...THE LAKE
REMAINS FAIRLY WARM NEAR 50 DEGREES WITH STRONG LOW LEVEL
INSTABILITY DEVELOPING ON SUNDAY. AFTER AN INITIAL PUSH OF SNOW
SHOWERS DURING THE MORNING...EXPECT THE SNOW TO BE BROKEN UP
SOMEWHAT DURING THE MIDDLE PART OF THE DAY. DURING THE AFTERNOON
HOWEVER THE WINDS SOUTH OF THE LAKE START TO BACK AS THE SURFACE
HIGH BUILDS INTO THE OHIO VALLEY. THIS HELPS TO ENHANCE LOW LEVEL
CONVERGENCE AND MAY ESTABLISH SOME STRONGER WEST TO EAST ORIENTED
BANDS OFF THE LAKE. THESE BANDS ARE THE PRIMARY REASON FOR THE
WATCH...WITH MODERATE TO HEAVY SNOWFALL POSSIBLE WHERE BANDS
PERSIST FROM SUNDAY AFTERNOON INTO SUNDAY NIGHT...GRADUALLY MOVING
NE UP THE LAKESHORE. NOT ENOUGH CONFIDENCE AT THIS POINT TO ISSUE
ANY WARNINGS OR ADVISORIES AS THESE BANDS ARE HARD TO PINPOINT.
AT THIS TIME THE HEAVIEST SNOWFALL EXPECTED OVER INLAND ERIE PA
WHERE TEMPERATURES WILL BE A LITTLE COOLER AND SEVERAL WINDOWS
EXIST TO ACCUMULATE SEVERAL INCHES AT A TIME. IF THOSE HEAVIER
BANDS DO DEVELOP ON SUNDAY THEN COULD NEED ADVISORIES THAT ARE NOT
CURRENTLY IN THE WATCH. TRIMMED THE ENDING TIME OF THE WATCH TO 7
AM MONDAY AS THE FLOW WILL BE OUT OF THE SOUTH BY THAT TIME AND
ANY LINGERING SNOW SHOULD SHIFT BACK OUT OVER THE LAKE.
ANOTHER LOW PRESSURE SYSTEM WILL MOVE ACROSS THE UPPER GREAT LAKES
ON MONDAY/MONDAY NIGHT. THIS SYSTEM WILL BRING ANOTHER CHANCE OF
SNOW ALONG THE LAKE ERIE SHORELINE.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
PATTERN WILL RETURN TO A WESTERN TROUGH/EASTERN RIDGE
BY MID WEEK. THEREFORE THE AREA WILL BE DRY AND BACK AT OR SLIGHTLY
ABOVE NORMAL FOR THE SECOND HALF OF THE WEEK INCLUDING THE HOLIDAY.
THE LONGWAVE TROUGH GETS HELPED ALONG BY A NORTHERN WAVE THAT WILL
ALLOW COLDER AIR TO INTRUDE ONCE AGAIN. THEREFORE CHANGES WILL
ARRIVE ON FRIDAY INTO SATURDAY WITH THE ARRIVAL OF A COLD FRONT.
RAIN AHEAD...SNOW SHOWERS AND POSSIBLE LAKE EFFECT ON THE BACKSIDE.
MODELS ARE IN MUCH BETTER AGREEMENT TODAY...WHICH IS GOOD
CONSIDERING THE NORTHERN/SOUTHERN INTERACTIONS.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
AT 2330Z LOW PRESSURE WAS LOCATED OVER CENTRAL LAKE ERIE WITH A
COLD FRONT EXTENDING SOUTHWARD TO KBJJ TO EAST OF COLUMBUS. THIS
FRONT WILL MOVE QUICKLY EASTWARD WITH ITS SWATH OF RAINFALL. MUCH
OF THIS RAIN IS STRUGGLING TO REACH THE SURFACE WITH THE VERY DRY
LOWER LEVELS OF THE ATMOSPHERE. CEILINGS WILL LOWER ACROSS THE
EAST THROUGH 02Z AND SHOULD ALL REACH MVFR LEVELS BY 04Z.
SOUTHWEST TO WEST WINDS WILL BECOME GUSTY IN THE WAKE OF THE FRONT
WITH 25 TO 30 KNOTS LIKELY. WINDS WILL DECREASE BY SUNRISE BUT
WILL REMAIN WESTERLY THROUGH THE DAY ON SUNDAY.
THE ONLY SNOW SO FAR HAS BEEN AT KTOL WHERE AROUND AN INCH OF SNOW
HAS OCCURRED. THE HEAVIEST SNOW HAS ENDED IN THIS AREA BUT
BELIEVE SOME 3 TO 5 MILE SNOW WILL CONTINUE THROUGH 03Z OR 04Z.
VERY LITTLE ADDITIONAL ACCUMULATION IS ANTICIPATED. ELSEWHERE IT
LOOKS AS IF THE SNOW WILL BE LITTLE MORE THAN FLURRIES AFTER
MIDNIGHT BUT MAY SEE NOTHING AT ALL. WE WILL THEN WATCH FOR SOME
LAKE EFFECT SNOW TO DEVELOP. THE MAIN SWATH OF SNOW WILL BE INTO
NW PA AND MAY IMPACT KERI AFTER 10Z. THE BEST CHANCE TO SEE LAKE
EFFECT SNOW WILL BE FROM SUNRISE TILL AROUND NOON.
OUTLOOK...NON VFR POSSIBLE NE OHIO INTO NW PA SUN NIGHT THROUGH
MONDAY NIGHT WITH LOWER CEILINGS AND SOME SNOW POSSIBLE.
&&
.MARINE...
NO CHANGES MADE TO THE ARRANGEMENT OF THE GALE WARNING
THAT BEGINS THIS EVENING. LOW CENTER EXPECTED TO TRACK NEAR OR JUST
WEST OF CLEVELAND. OVERALL WIND WILL BE ON THE INCREASE AS THE
DIRECTION SHIFTS AROUND TO THE WEST AS THE LOW GETS NORTHEAST OF THE
LAKE. THE PERIOD OF TIME FOR THE GALES IS RATHER NARROW AND WINDS
WILL BE SLOWLY DECREASING BY MID MORNING SUNDAY. SMALL CRAFT
ADVISORIES WILL CERTAINLY FOLLOW THE GALE FOR THE REST OF SUNDAY AND
SUNDAY NIGHT. HIGH PRESSURE SETS UP OVER THE OHIO VALLEY FOR SUNDAY
AND MONDAY...BUT A CLIPPER MOVING ACROSS THE NE FRINGES OF THE GREAT
LAKES WILL KEEP THE GRADIENT TIGHT AND SOUTHWEST FLOW WILL REMAIN
BRISK. EVENTUALLY WINDS WILL SHIFT TO THE WEST MONDAY NIGHT AND THIS
IS ANOTHER PERIOD WHERE SMALL CRAFT ADVISORY CONDITIONS WILL LIKELY
BE MET. WINDS WILL DECREASE ON TUESDAY AS THE HIGH BECOMES MORE
CENTERED OVER THE EASTERN LAKES. SOUTH WINDS INCREASE ON THURSDAY
AHEAD OF A COLD FRONT FOR FRIDAY.&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...LAKE EFFECT SNOW WATCH FROM 4 AM EST SUNDAY THROUGH MONDAY
MORNING FOR OHZ014-089.
WIND ADVISORY UNTIL 7 AM EST SUNDAY FOR OHZ089.
PA...LAKE EFFECT SNOW WATCH FROM 4 AM EST SUNDAY THROUGH MONDAY
MORNING FOR PAZ001>003.
WIND ADVISORY UNTIL 7 AM EST SUNDAY FOR PAZ001.
MARINE...GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST SUNDAY FOR
LEZ061-142>149-162>169.
&&
.CLE WATCHES/WARNINGS/ADVISORIES...
OH...LAKE EFFECT SNOW WATCH FROM 4 AM EST SUNDAY THROUGH MONDAY
MORNING FOR OHZ014-089.
WIND ADVISORY UNTIL 7 AM EST SUNDAY FOR OHZ089.
PA...LAKE EFFECT SNOW WATCH FROM 4 AM EST SUNDAY THROUGH MONDAY
MORNING FOR PAZ001>003.
WIND ADVISORY UNTIL 7 AM EST SUNDAY FOR PAZ001.
MARINE...GALE WARNING FROM 10 PM THIS EVENING TO 1 PM EST SUNDAY FOR
LEZ061-142>149-162>169.
&&
$$
SYNOPSIS...KEC
NEAR TERM...LOMBARDY
SHORT TERM...KEC
LONG TERM...OUDEMAN
AVIATION...MULLEN
MARINE...OUDEMAN
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1033 PM EST SAT NOV 21 2015
.SYNOPSIS...
A COLD FRONT WITH SHOWERS WILL SWEEP EAST ACROSS PENNSYLVANIA
TONIGHT . COLDER AIR WILL MOVE IN BEHIND THE FRONT AND LAKE
ENHANCED SNOW SHOWERS WILL MOVE INTO THE MOUNTAINS ACROSS THE
NORTH AND CENTRAL TOWARD MORNING. SUNDAY WILL BE COLDER WITH SCATTERED
SNOW SHOWERS IN NORTHWEST AND MAYBE A SPRINKLE THROUGH THE
SUSQUEHANNA VALLEY. HIGH PRESSURE WILL MOVE IN AND BRING FAIR AND
MILD WEATHER FOR THANKSGIVING.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SHOWERS WERE MOVING INTO WESTERN PA AT 23Z AHEAD OF A COLD FRONT
THAT WAS THROUGH CENTRAL OH. THE FRONT AND SHOWERS WILL ADVANCE
EAST INTO PA WITH TEMPERATURES IN THE 40S. PRECIPITATION WILL BEGIN
AS ALL RAIN. COLDER AIR WILL MOVE IN BEHIND THE FRONT CHANGING
RAIN TO SNOW BEGINNING AT HIGHER ELEVATIONS IN THE NORTH AND WEST
AFTER MIDNIGHT. HIGH RESOLUTION MODELS MOVE SHOWERS FROM THE
LAUREL MOUNTAINS NORTH THROUGH WILLIAMSPORT AND TIOGA COUNTY BY
MIDNIGHT BUT THE AREA OF SHOWERS WILL BECOME LIGHTER AND MORE
SCATTERED AS IT MOVES FURTHER EAST OF THE MOUNTAINS. IT IS
UNCERTAIN THAT THE LOWER SUSQUEHANNA VALLEY WILL SEE ANY RAIN AT
ALL. BACKED OFF SOME ON BOTH THE QPF AND THE SNOWFALL OVER THE
NORTHWEST BEHIND THE FRONT. BEST CHANCE FOR ANY MEASURABLE SNOW
BY MORNING REMAINS ACROSS HIGHER TERRAIN IN THE NORTHWEST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SUNDAY WILL TURN MARKEDLY COLDER AND BREEZY.
THE COLD AIR...WARM LAKES AND MEAN SFC-800MB 250-270 DEG WINDS
INDICATE A POTENTIAL FOR SINGLE LAKE ERIE SNOW BAND INITIALLY
ALONG THE I-90 CORRIDOR LATER TONIGHT AND SUNDAY MORNING...
TRANSITIONING INTO A MORE MULTI-BAND SETUP DURING THE DAY SUNDAY
INTO SUNDAY NIGHT. AT THIS TIME...LATEST OPERATIONAL MODELS AND
THE SREF IS SUGGESTING 2-4 INCHES OF SNOW POSSIBLE NEAR THE NY
BORDER WITH WARREN COUNTY...BUT BEST SNOW IS LIKELY JUST TO THE
NORTH OF THE PA/NY BORDER.
WE HAVE CANCELED THE LES WATCH FOR NW WARREN COUNTY AT THIS TIME
AS ALL INDICATIONS ARE THAT THE SNOW WILL BE LIGHT AND NOT REACH
ADVISORY OR WARNING CRITERIA FOR A 12 HOUR SNOWFALL.
SUNDAY WILL BE COLD AND BREEZY WITH FLURRIES AND A FEW SNOW
SHOWERS ACROSS THE LAURELS...AND AND PERHAPS A FEW LIGHT SNOW
SHOWERS OR FLURRIES BLEEDING INTO THE CENTRAL MOUNTAINS AT TIMES.
HIGH TEMPS WILL RANGE FROM NEAR 32 ACROSS THE NRN AND WRN
MOUNTAINS...AND UPPER 30S TO L40S ACROSS THE CENTRAL AND SE
VALLEY LOCATIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
LOOKING AT A SEE-SAW WEATHER PATTERN THIS PERIOD AS WE START OFF
THE PERIOD WITH A DEEPENING RELATIVE CHILL AS A SERIES OF
SHORTWAVE TROFS REINFORCE COOLER AIR ESTABLISHED OVER THE REGION
THIS WEEKEND...BEFORE THE START OF THE LONG TERM PERIOD. EARLY NEXT
WEEK THE PATTERN IS FORECAST TO TRANSITION TO A ZONAL FLOW THEN HEIGHTS
RISE OVER THE EASTERN U.S. IN RESPONSE TO A DIGGING UPPER TROF
OVER THE CENTRAL ROCKIES.
THE COLD AIR SHOULD SLOWLY EASE ON MONDAY INTO MONDAY NIGHT. WE
BOTTOM OUT -1 TO -1.5SD BELOW NORMAL FOR 850 MB TEMPS SUNDAY INTO
MONDAY EVENING.
AT THE SURFACE HIGH PRESSURE WILL DOMINATE OUR WEATHER TUESDAY TO
FRIDAY...THE CENTER OF THE HIGH WILL DRIFT OVER THE WESTERN
ATLANTIC...THE PATTERN IMPLIES LOW-LEVEL TRAPPED COLD AIR AS WARM
AIR BUILDS IN ALOFT AND A RIDGE BUILDS AT 500 MB TO OUR WEST. A
WARM LOOKING PATTERN ABOVE THE SURFACE. THE DEEP SOUTHWEST FLOW
IMPLIES INCREASED CHANCE RAIN TOWARD THE WEEKEND BUT NOTHING AT
THIS TIME TO FOCUS ON.
THE 850 MB TEMPERATURES WILL BE A BIT ABOVE NORMAL BY
THANKSGIVING AND PERHAPS INTO EARLY SATURDAY. LOTS OF UNCERTAINTY
AND SOME GEFS AND NAEFS MEMBERS SHOW COLD AIR SAGGING SOUTH
FRIDAY-SATURDAY. SO THE GEFS SHOWS SLIGHTLY ABOVE NORMAL
TEMPERATURES WED-FRIDAY BUT LATE FRIDAY-SATURDAY THE 2M
TEMPERATURE PLUMES SHOW HUGE SPREAD AND LOTS OF UNCERTAINTY. WILL
IT GET WARM OR A SHALLOW FRONT SLIDE THROUGH? INITIALLY THE MEDIAN
IS HIGHER THEN THE MEAN...FRIDAY SHOULD BE WARM...SATURDAY THE
MEDIAN IS BELOW THE MEAN...SATURDAY HIGHER PROBABILITY OF BEING
COLDER THAN FORECAST AS WE TEND TO THE MEAN.
&&
.AVIATION /04Z SUNDAY THROUGH THURSDAY/...
MAIN AVIATION CONCERN LATE THIS EVENING WILL BE THE POSSIBILITY
OF LLWS...AS CORE OF STRONG WINDS ALOFT OVERSPREAD THE AREA IN
ADVANCE OF APPROACHING COLD FRONT. LATEST BUFKIT SOUNDINGS SUPPORT
A BRIEF PERIOD OF LLWS CRITERIA ACROSS MUCH OF CENTRAL PA LATE
THIS EVENING.
COLD FRONT WILL SWEEP THRU CENTRAL PA BTWN 04Z-07Z...ACCOMPANIED
BY A FEW SHRA ACROSS THE W MTNS. MVFR CONDS COULD ACCOMPANY THE
FRONTAL SHOWERS AT KBFD/KJST. HOWEVER...A BIGGER CONCERN MAY
BE STRONG...GUSTY WSW WINDS ACCOMPANYING AND IMMEDIATELY
FOLLOWING THE FRONTAL PASSAGE. HRRR AND LATEST NAM SOUNDINGS
INDICATE THE POSSIBILITY OF GUSTS BTWN 35-40KTS AT KBFD/KJST BTWN
04Z-07Z...WITH SOMEWHAT WEAKER GUSTS FOLLOWING FROPA FURTHER
EAST.
COLD AIR FLOWING OVER THE GREAT LAKES WILL PRODUCE LAKE EFFECT
SNOW SHOWERS ACROSS PORTIONS OF NW PA LATE TONIGHT AND SUNDAY.
HOWEVER...LATEST MDL DATA SUGGESTS THE SIG VIS REDUCTIONS WILL
REMAIN JUST NORTHWEST OF KBFD. ELSEWHERE...WIDESPREAD VFR CONDS
APPEAR VERY LIKELY THRU SUNDAY WITH THE POSSIBLE EXCEPTION OF OCNL
MVFR CIGS AT KJST.
OUTLOOK...
MON-THU...NO SIG WX EXPECTED.
&&
.CLIMATE...
ISSUED AT 148 AM EST SAT NOV 21 2015
WITH 10 DAYS LEFT IN THE MONTH...PRELIMINARY CLIMATE DATA
INDICATES THAT NOVEMBER 2015 IS CURRENTLY ON TRACK TO BE THE
WARMEST NOVEMBER ON RECORD AT OUR TWO LONG TERM CLIMATE SITES:
HARRISBURG AND WILLIAMSPORT. A CONTINUOUS WEATHER RECORD HAS BEEN
KEPT AT EACH SITE SINCE 1888 AND 1895 RESPECTIVELY.
THROUGH 11/20...
THE AVG. MONTHLY TEMPERATURE AT HARRISBURG IS 53.2 DEGREES OR
+7.2 DEGREES ABOVE NORMAL.
THE AVG. MONTHLY TEMPERATURE AT WILLIAMSPORT IS 50.9 DEGREES OR
+7.5 DEGREES ABOVE NORMAL.
THE TOP 5 WARMEST NOVEMBERS (CURRENT RANKINGS)
MDT: 2015 (53.2), 1931 (51.3), 1975 (50.0), 1999 (49.3), 1994
(49.0)
IPT: 2015 (50.9), 1931 (48.8), 1902 (47.3), 2009/1972 (47.2), 1913
(46.3)
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WATSON
NEAR TERM...WATSON
SHORT TERM...LA CORTE
LONG TERM...GRUMM/GARTNER
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
651 PM EST SAT NOV 21 2015
.SYNOPSIS...
A COLD FRONT WITH SHOWERS WILL SWEEP EAST ACROSS PENNSYLVANIA
TONIGHT . COLDER AIR WILL MOVE IN BEHIND THE FRONT AND LAKE
ENHANCED SNOW SHOWERS WILL MOVE INTO THE MOUNTAINS ACROSS THE
NORTH AND CENTRAL TOWARD MORNING. SUNDAY WILL BE COLDER WITH SCATTERED
SNOW SHOWERS IN NORTHWEST AND MAYBE A SPRINKLE THROUGH THE
SUSQUEHANNA VALLEY. HIGH PRESSURE WILL MOVE IN AND BRING FAIR AND
MILD WEATHER FOR THANKSGIVING.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SHOWERS WERE MOVING INTO WESTERN PA AT 23Z AHEAD OF A COLD FRONT
THAT WAS THROUGH CENTRAL OH. THE FRONT AND SHOWERS WILL ADVANCE
EAST INTO PA WITH TEMPERATURES IN THE 40S. PRECIPITATION WILL BEGIN
AS ALL RAIN. COLDER AIR WILL MOVE IN BEHIND THE FRONT CHANGING
RAIN TO SNOW BEGINNING AT HIGHER ELEVATIONS IN THE NORTH AND WEST
AFTER MIDNIGHT. HIGH RESOLUTION MODELS MOVE SHOWERS FROM THE
LAUREL MOUNTAINS NORTH THROUGH WILLIAMSPORT AND TIOGA COUNTY BY
MIDNIGHT BUT THE AREA OF SHOWERS WILL BECOME LIGHTER AND MORE
SCATTERED AS IT MOVES FURTHER EAST OF THE MOUNTAINS. IT IS
UNCERTAIN THAT THE LOWER SUSQUEHANNA VALLEY WILL SEE ANY RAIN AT
ALL. BACKED OFF SOME ON BOTH THE QPF AND THE SNOWFALL OVER THE
NORTHWEST BEHIND THE FRONT. BEST CHANCE FOR ANY MEASURABLE SNOW
BY MORNING REMAINS ACROSS HIGHER TERRAIN IN THE NORTHWEST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SUNDAY WILL TURN MARKEDLY COLDER AND BREEZY.
THE COLD AIR...WARM LAKES AND MEAN SFC-800MB 250-270 DEG WINDS
INDICATE A POTENTIAL FOR SINGLE LAKE ERIE SNOW BAND INITIALLY
ALONG THE I-90 CORRIDOR LATER TONIGHT AND SUNDAY MORNING...
TRANSITIONING INTO A MORE MULTI-BAND SETUP DURING THE DAY SUNDAY
INTO SUNDAY NIGHT. AT THIS TIME...LATEST OPERATIONAL MODELS AND
THE SREF IS SUGGESTING 2-4 INCHES OF SNOW POSSIBLE NEAR THE NY
BORDER WITH WARREN COUNTY...BUT BEST SNOW IS LIKELY JUST TO THE
NORTH OF THE PA/NY BORDER.
WE HAVE CANCELED THE LES WATCH FOR NW WARREN COUNTY AT THIS TIME
AS ALL INDICATIONS ARE THAT THE SNOW WILL BE LIGHT AND NOT REACH
ADVISORY OR WARNING CRITERIA FOR A 12 HOUR SNOWFALL.
SUNDAY WILL BE COLD AND BREEZY WITH FLURRIES AND A FEW SNOW
SHOWERS ACROSS THE LAURELS...AND AND PERHAPS A FEW LIGHT SNOW
SHOWERS OR FLURRIES BLEEDING INTO THE CENTRAL MOUNTAINS AT TIMES.
HIGH TEMPS WILL RANGE FROM NEAR 32 ACROSS THE NRN AND WRN
MOUNTAINS...AND UPPER 30S TO L40S ACROSS THE CENTRAL AND SE
VALLEY LOCATIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
LOOKING AT A SEE-SAW WEATHER PATTERN THIS PERIOD AS WE START OFF
THE PERIOD WITH A DEEPENING RELATIVE CHILL AS A SERIES OF
SHORTWAVE TROFS REINFORCE COOLER AIR ESTABLISHED OVER THE REGION
THIS WEEKEND...BEFORE THE START OF THE LONG TERM PERIOD. EARLY NEXT
WEEK THE PATTERN IS FORECAST TO TRANSITION TO A ZONAL FLOW THEN HEIGHTS
RISE OVER THE EASTERN U.S. IN RESPONSE TO A DIGGING UPPER TROF
OVER THE CENTRAL ROCKIES.
THE COLD AIR SHOULD SLOWLY EASE ON MONDAY INTO MONDAY NIGHT. WE
BOTTOM OUT -1 TO -1.5SD BELOW NORMAL FOR 850 MB TEMPS SUNDAY INTO
MONDAY EVENING.
AT THE SURFACE HIGH PRESSURE WILL DOMINATE OUR WEATHER TUESDAY TO
FRIDAY...THE CENTER OF THE HIGH WILL DRIFT OVER THE WESTERN
ATLANTIC...THE PATTERN IMPLIES LOW-LEVEL TRAPPED COLD AIR AS WARM
AIR BUILDS IN ALOFT AND A RIDGE BUILDS AT 500 MB TO OUR WEST. A
WARM LOOKING PATTERN ABOVE THE SURFACE. THE DEEP SOUTHWEST FLOW
IMPLIES INCREASED CHANCE RAIN TOWARD THE WEEKEND BUT NOTHING AT
THIS TIME TO FOCUS ON.
THE 850 MB TEMPERATURES WILL BE A BIT ABOVE NORMAL BY
THANKSGIVING AND PERHAPS INTO EARLY SATURDAY. LOTS OF UNCERTAINTY
AND SOME GEFS AND NAEFS MEMBERS SHOW COLD AIR SAGGING SOUTH
FRIDAY-SATURDAY. SO THE GEFS SHOWS SLIGHTLY ABOVE NORMAL
TEMPERATURES WED-FRIDAY BUT LATE FRIDAY-SATURDAY THE 2M
TEMPERATURE PLUMES SHOW HUGE SPREAD AND LOTS OF UNCERTAINTY. WILL
IT GET WARM OR A SHALLOW FRONT SLIDE THROUGH? INITIALLY THE MEDIAN
IS HIGHER THEN THE MEAN...FRIDAY SHOULD BE WARM...SATURDAY THE
MEDIAN IS BELOW THE MEAN...SATURDAY HIGHER PROBABILITY OF BEING
COLDER THAN FORECAST AS WE TEND TO THE MEAN.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
MAIN AVIATION CONCERN THIS EVENING WILL BE THE POSSIBILITY OF
LLWS...AS CORE OF STRONG WINDS ALOFT OVERSPREAD THE AREA IN
ADVANCE OF APPROACHING COLD FRONT. LATEST BUFKIT SOUNDINGS SUPPORT
A BRIEF PERIOD OF LLWS CRITERIA ACROSS MUCH OF CENTRAL PA LATE
THIS EVENING.
COLD FRONT WILL SWEEP THRU CENTRAL PA BTWN 04Z-07Z...ACCOMPANIED
BY A FEW SHRA ACROSS THE W MTNS. MVFR CONDS COULD ACCOMPANY THE
FRONTAL SHOWERS AT KBFD/KJST. HOWEVER...A BIGGER CONCERN MAY
BE STRONG...GUSTY WSW WINDS ACCOMPANYING AND IMMEDIATELY
FOLLOWING THE FRONTAL PASSAGE. HRRR AND LATEST NAM SOUNDINGS
INDICATE THE POSSIBILITY OF GUSTS BTWN 35-40KTS AT KBFD/KJST BTWN
04Z-07Z...WITH SOMEWHAT WEAKER GUSTS FOLLOWING FROPA FURTHER
EAST.
COLD AIR FLOWING OVER THE GREAT LAKES WILL PRODUCE LAKE EFFECT
SNOW SHOWERS ACROSS PORTIONS OF NW PA LATE TONIGHT AND SUNDAY.
HOWEVER...LATEST MDL DATA SUGGESTS THE SIG VIS REDUCTIONS WILL
REMAIN JUST NORTHWEST OF KBFD. ELSEWHERE...WIDESPREAD VFR CONDS
APPEAR VERY LIKELY THRU SUNDAY WITH THE POSSIBLE EXCEPTION OF OCNL
MVFR CIGS AT KJST.
OUTLOOK...
MON-THU...NO SIG WX EXPECTED.
&&
.CLIMATE...
ISSUED AT 148 AM EST SAT NOV 21 2015
WITH 10 DAYS LEFT IN THE MONTH...PRELIMINARY CLIMATE DATA
INDICATES THAT NOVEMBER 2015 IS CURRENTLY ON TRACK TO BE THE
WARMEST NOVEMBER ON RECORD AT OUR TWO LONG TERM CLIMATE SITES:
HARRISBURG AND WILLIAMSPORT. A CONTINUOUS WEATHER RECORD HAS BEEN
KEPT AT EACH SITE SINCE 1888 AND 1895 RESPECTIVELY.
THROUGH 11/20...
THE AVG. MONTHLY TEMPERATURE AT HARRISBURG IS 53.2 DEGREES OR
+7.2 DEGREES ABOVE NORMAL.
THE AVG. MONTHLY TEMPERATURE AT WILLIAMSPORT IS 50.9 DEGREES OR
+7.5 DEGREES ABOVE NORMAL.
THE TOP 5 WARMEST NOVEMBERS (CURRENT RANKINGS)
MDT: 2015 (53.2), 1931 (51.3), 1975 (50.0), 1999 (49.3), 1994
(49.0)
IPT: 2015 (50.9), 1931 (48.8), 1902 (47.3), 2009/1972 (47.2), 1913
(46.3)
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WATSON
NEAR TERM...WATSON
SHORT TERM...LA CORTE
LONG TERM...GRUMM/GARTNER
AVIATION...FITZGERALD
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
633 PM EST SAT NOV 21 2015
.SYNOPSIS...
A COLD FRONT WITH SHOWERS WILL SWEEP EAST ACROSS PENNSYLVANIA
TONIGHT . COLDER AIR WILL MOVE IN BEHIND THE FRONT AND LAKE
ENHANCED SNOW SHOWERS WILL MOVE INTO THE MOUNTAINS ACROSS THE
NORTH AND CENTRAL TOWARD MORNING. SUNDAY WILL BE COLDER WITH SCATTERED
SNOW SHOWERS IN NORTHWEST AND MAYBE A SPRINKLE THROUGH THE
SUSQUEHANNA VALLEY. HIGH PRESSURE WILL MOVE IN AND BRING FAIR AND
MILD WEATHER FOR THANKSGIVING.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
SHOWERS WERE MOVING INTO WESTERN PA AT 23Z AHEAD OF A COLD FRONT
THAT WAS THROUGH CENTRAL OH. THE FRONT AND SHOWERS WILL ADVANCE
EAST INTO PA WITH TEMPERATURES IN THE 40S. PRECIPITATION WILL BEGIN
AS ALL RAIN. COLDER AIR WILL MOVE IN BEHIND THE FRONT CHANGING
RAIN TO SNOW BEGINNING AT HIGHER ELEVATIONS IN THE NORTH AND WEST
AFTER MIDNIGHT. HIGH RESOLUTION MODELS MOVE SHOWERS FROM THE
LAUREL MOUNTAINS NORTH THROUGH WILLIAMSPORT AND TIOGA COUNTY BY
MIDNIGHT BUT THE AREA OF SHOWERS WILL BECOME LIGHTER AND MORE
SCATTERED AS IT MOVES FURTHER EAST OF THE MOUNTAINS. IT IS
UNCERTAIN THAT THE LOWER SUSQUEHANNA VALLEY WILL SEE ANY RAIN AT
ALL. BACKED OFF SOME ON BOTH THE QPF AND THE SNOWFALL OVER THE
NORTHWEST BEHIND THE FRONT. BEST CHANCE FOR ANY MEASURABLE SNOW
BY MORNING REMAINS ACROSS HIGHER TERRAIN IN THE NORTHWEST.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
SUNDAY WILL TURN MARKEDLY COLDER AND BREEZY.
THE COLD AIR...WARM LAKES AND MEAN SFC-800MB 250-270 DEG WINDS
INDICATE A POTENTIAL FOR SINGLE LAKE ERIE SNOW BAND INITIALLY
ALONG THE I-90 CORRIDOR LATER TONIGHT AND SUNDAY MORNING...
TRANSITIONING INTO A MORE MULTI-BAND SETUP DURING THE DAY SUNDAY
INTO SUNDAY NIGHT. AT THIS TIME...LATEST OPERATIONAL MODELS AND
THE SREF IS SUGGESTING 2-4 INCHES OF SNOW POSSIBLE NEAR THE NY
BORDER WITH WARREN COUNTY...BUT BEST SNOW IS LIKELY JUST TO THE
NORTH OF THE PA/NY BORDER.
WE HAVE CANCELED THE LES WATCH FOR NW WARREN COUNTY AT THIS TIME
AS ALL INDICATIONS ARE THAT THE SNOW WILL BE LIGHT AND NOT REACH
ADVISORY OR WARNING CRITERIA FOR A 12 HOUR SNOWFALL.
SUNDAY WILL BE COLD AND BREEZY WITH FLURRIES AND A FEW SNOW
SHOWERS ACROSS THE LAURELS...AND AND PERHAPS A FEW LIGHT SNOW
SHOWERS OR FLURRIES BLEEDING INTO THE CENTRAL MOUNTAINS AT TIMES.
HIGH TEMPS WILL RANGE FROM NEAR 32 ACROSS THE NRN AND WRN
MOUNTAINS...AND UPPER 30S TO L40S ACROSS THE CENTRAL AND SE
VALLEY LOCATIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
LOOKING AT A SEE-SAW WEATHER PATTERN THIS PERIOD AS WE START OFF
THE PERIOD WITH A DEEPENING RELATIVE CHILL AS A SERIES OF
SHORTWAVE TROFS REINFORCE COOLER AIR ESTABLISHED OVER THE REGION
THIS WEEKEND...BEFORE THE START OF THE LONG TERM PERIOD. EARLY NEXT
WEEK THE PATTERN IS FORECAST TO TRANSITION TO A ZONAL FLOW THEN HEIGHTS
RISE OVER THE EASTERN U.S. IN RESPONSE TO A DIGGING UPPER TROF
OVER THE CENTRAL ROCKIES.
THE COLD AIR SHOULD SLOWLY EASE ON MONDAY INTO MONDAY NIGHT. WE
BOTTOM OUT -1 TO -1.5SD BELOW NORMAL FOR 850 MB TEMPS SUNDAY INTO
MONDAY EVENING.
AT THE SURFACE HIGH PRESSURE WILL DOMINATE OUR WEATHER TUESDAY TO
FRIDAY...THE CENTER OF THE HIGH WILL DRIFT OVER THE WESTERN
ATLANTIC...THE PATTERN IMPLIES LOW-LEVEL TRAPPED COLD AIR AS WARM
AIR BUILDS IN ALOFT AND A RIDGE BUILDS AT 500 MB TO OUR WEST. A
WARM LOOKING PATTERN ABOVE THE SURFACE. THE DEEP SOUTHWEST FLOW
IMPLIES INCREASED CHANCE RAIN TOWARD THE WEEKEND BUT NOTHING AT
THIS TIME TO FOCUS ON.
THE 850 MB TEMPERATURES WILL BE A BIT ABOVE NORMAL BY
THANKSGIVING AND PERHAPS INTO EARLY SATURDAY. LOTS OF UNCERTAINTY
AND SOME GEFS AND NAEFS MEMBERS SHOW COLD AIR SAGGING SOUTH
FRIDAY-SATURDAY. SO THE GEFS SHOWS SLIGHTLY ABOVE NORMAL
TEMPERATURES WED-FRIDAY BUT LATE FRIDAY-SATURDAY THE 2M
TEMPERATURE PLUMES SHOW HUGE SPREAD AND LOTS OF UNCERTAINTY. WILL
IT GET WARM OR A SHALLOW FRONT SLIDE THROUGH? INITIALLY THE MEDIAN
IS HIGHER THEN THE MEAN...FRIDAY SHOULD BE WARM...SATURDAY THE
MEDIAN IS BELOW THE MEAN...SATURDAY HIGHER PROBABILITY OF BEING
COLDER THAN FORECAST AS WE TEND TO THE MEAN.
&&
.AVIATION /23Z SATURDAY THROUGH THURSDAY/...
MAIN AVIATION CONCERN THIS EVENING WILL BE THE POSSIBILITY OF
LLWS...AS CORE OF STRONG WINDS ALOFT OVERSPREAD THE AREA IN
ADVANCE OF APPROACHING COLD FRONT. LATEST BUFKIT SOUNDINGS SUPPORT
A BRIEF PERIOD OF LLWS CRITERIA ACROSS MUCH OF CENTRAL PA LATE
THIS EVENING.
COLD FRONT WILL SWEEP THRU CENTRAL PA BTWN 04Z-07Z...ACCOMPANIED
BY A FEW SHRA ACROSS THE W MTNS. MVFR CONDS COULD ACCOMPANY THE
FRONTAL SHOWERS AT KBFD/KJST. HOWEVER...A BIGGER CONCERN MAY
STRONG...GUSTY WSW WINDS ACCOMPANYING AND IMMEDIATELY FOLLOWING
THE FRONTAL PASSAGE. HRRR AND LATEST NAM SOUNDINGS INDICATE THE
POSSIBILITY OF GUSTS BTWN 35-40KTS AT KBFD/KJST BTWN 04Z-07Z...WITH
SOMEWHAT WEAKER GUSTS FURTHER EAST.
COLD AIR FLOWING OVER THE GREAT LAKES WILL PRODUCE LAKE EFFECT
SNOW SHOWERS ACROSS PORTIONS OF NW PA LATE TONIGHT AND SUNDAY.
HOWEVER...LATEST MDL DATA SUGGESTS THE SIG VIS REDUCTIONS WILL
REMAIN JUST NORTHWEST OF KBFD. ELSEWHERE...WIDESPREAD VFR CONDS
APPEAR VERY LIKELY THRU SUNDAY WITH THE POSSIBLE EXCEPTION OF OCNL
MVFR CIGS AT KJST.
OUTLOOK...SUNDAY-WEDNESDAY
MON-TUE...MVFR WITH CHC -SHSN NW. VFR/NO SIG WX ELSEWHERE.
WED-THU...VFR/NO SIG WX.
&&
.CLIMATE...
ISSUED AT 148 AM EST SAT NOV 21 2015
WITH 10 DAYS LEFT IN THE MONTH...PRELIMINARY CLIMATE DATA
INDICATES THAT NOVEMBER 2015 IS CURRENTLY ON TRACK TO BE THE
WARMEST NOVEMBER ON RECORD AT OUR TWO LONG TERM CLIMATE SITES:
HARRISBURG AND WILLIAMSPORT. A CONTINUOUS WEATHER RECORD HAS BEEN
KEPT AT EACH SITE SINCE 1888 AND 1895 RESPECTIVELY.
THROUGH 11/20...
THE AVG. MONTHLY TEMPERATURE AT HARRISBURG IS 53.2 DEGREES OR
+7.2 DEGREES ABOVE NORMAL.
THE AVG. MONTHLY TEMPERATURE AT WILLIAMSPORT IS 50.9 DEGREES OR
+7.5 DEGREES ABOVE NORMAL.
THE TOP 5 WARMEST NOVEMBERS (CURRENT RANKINGS)
MDT: 2015 (53.2), 1931 (51.3), 1975 (50.0), 1999 (49.3), 1994
(49.0)
IPT: 2015 (50.9), 1931 (48.8), 1902 (47.3), 2009/1972 (47.2), 1913
(46.3)
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WATSON
NEAR TERM...WATSON
SHORT TERM...WATSON/LA CORTE
LONG TERM...GRUMM/GARTNER
AVIATION...FITZGERALD/LA CORTE
CLIMATE...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
1124 AM CST FRI NOV 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CST FRI NOV 20 2015
PRESENT RADAR SHOWING DEVELOPING SNOW BAND FROM SOUTHWESTERN SOUTH
DAKOTA TO NORTH CENTRAL NEBRASKA VERY EARLY THIS MORNING...THOUGH
NOT SEEING ANY SNOW REACHING THE GROUND ON THE EASTERN EXTENT OF THE
BAND WITH DRY LOW LEVEL AIR IN PLACE. THIS AREA OF SNOW LOOKS TO BE
COLLOCATED WELL WITH MODEL 700 MB FRONTOGENESIS FIELDS. STILL LOOKING
AT A DECENT SNOW EVENT ACROSS THE AREA TODAY WITH STRENGTHENING MID
LEVEL FRONTOGENESIS AND UPPER LEVEL LIFT AIDED BY A JET STREAK
SITUATED THROUGH NORTHERN SOUTH DAKOTA INTO MINNESOTA. MODELS IN
FAIRLY DECENT AGREEMENT ON A STRONG FRONTOGENETIC BAND DEVELOPING
INTO SOUTH CENTRAL SOUTH DAKOTA IN THE EARLY MORNING...THEN
SPLITTING TO THE NORTH AND SOUTH BY LATE MORNING...WITH THE SOUTHERN
BAND BECOMING DOMINATE OVER NORTHWESTERN IOWA BY AFTERNOON AS
OPTIMUM 500-300 MB DIV Q SLIDES THROUGH SOUTHERN SOUTH DAKOTA AND
NEBRASKA DURING THAT TIME FRAME. THIS SCENARIO POINTS TO HEAVY SNOW
DEVELOPING SOUTH OF INTERSTATE 90 DURING THE DAY...WITH AMOUNTS
DECREASING RAPIDLY TO THE NORTH WHERE DRIER AIR WILL BE GREATER AND
FORCING IS LESS. WHAT IS SOMEWHAT DISTURBING IS THAT MOST RECENT
MODEL RUNS...INCLUDING THE RAP AND HRRR ARE TRENDING FARTHER TO THE
NORTH WITH THE MORNING PERIOD SNOWFALL IN THE INITIAL FRONTOGENETIC
BAND...PLACING IT RIGHT ALONG THE INTERSTATE 90 CORRIDOR...BEFORE
COLLAPSING IT SOUTHWARD BY AFTERNOON AS EXPLAINED ABOVE. IN
ADDITION...THEY ARE HINTING AT SOME INSTABILITY OF THE FRONT SO
THERE COULD BE A PERIOD OF HEAVIER SNOWFALL IN THIS VICINITY DURING
THE MORNING HOURS. STILL THINKING THE GENERAL HEAVIER SNOW WILL BE
SOUTH OF I90 FOR MOST OF THE DAY...BUT WILL BE SOMETHING TO KEEP AN
EYE ON. WINDS WILL REMAIN ON THE LIGHTER SIDE TODAY...SO BLOWING
SNOW SHOULD NOT BE AN ISSUE. REMAINED BELOW GUIDANCE WITH RESPECT TO
TEMPERATURES...WITH PRECIPITATION AND WET BULBING EFFECTS...SO
LOOKING AT HIGHS JUST EITHER SIDE OF 30 DEGREES. USING SNOW RATIOS
IN THE RANGE OF 11:1 TO 15:1 AND CURRENTLY PROJECTED TOTAL SNOWFALL
AMOUNTS RANGE FROM JUST UNDER AN INCH ALONG THE HIGHWAY 14
CORRIDOR...TO 4 TO 6 INCHES ALONG THE I90 CORRIDOR...TO 6 TO 9
INCHES SOUTH OF THAT AREA...TRENDING HIGHEST TOWARD NORTHWESTERN
IOWA. IN LIGHT OF ALL THE ABOVE REASONING...ISSUED A WINTER WEATHER
ADVISORY ONE STRIP OF COUNTIES FARTHER TO THE NORTH THAN PREVIOUS
FORECAST...ALONG THE I90 CORRIDOR...WITH A WINTER STORM WARNING FOR
AREAS TO THE SOUTH.
BY THIS EVENING THE MIDLEVEL FRONTOGENETIC FORCING SLIDES EASTWARD
INTO NORTH CENTRAL AND NORTHEASTERN IOWA WITH MAXIMUM UPPER LEVEL
DIV Q FOLLOWING SUIT. WITH THAT...WILL SEE SNOW TAPER OFF FROM WEST
TO EAST DURING THE EVENING. MAY GET SOME CLEARING LATER IN THE
NIGHT...AND WENT ON THE LOWER SIDE OF GUIDANCE...ESPECIALLY IN
EXPECTED SNOW COVERED AREAS...WITH OVERNIGHT READINGS IN THE MID
TEENS NORTH TO AROUND 10 SOUTH OF THE I90 CORRIDOR.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 AM CST FRI NOV 20 2015
A DRY FIRST HALF OF THE MEDIUM RANGE FORECAST...WITH MORE UNSETTLED
WEATHER TAKING AIM FOR THE THANKSGIVING HOLIDAY. EARLY ON THIS
WEEKEND...BEHIND TODAYS DEPARTING SNOWSTORM...THE MAIN CONCERN WILL
BE WITH TEMPERATURES. THE FIRST COLD DAY OF THE LATE FALL AND EARLY
WINTER SEASON WILL ARRIVE ON SATURDAY. FRESH SNOW COVER...COMBINED
WITH H850 MB TEMPERATURES -10 TO -14C WILL KEEP TEMPERATURES WELL
BELOW NORMAL THIS WEEKEND. SATURDAYS HIGHS MAY STRUGGLE TO BREAK
FREE FROM THE MID 20S. ON SUNDAY...WE WILL HAVE A RETURN OF
SOUTHWESTERLY BOUNDARY LAYER AND LOW LEVEL FLOW...BUT FRESH SNOW
COVER WILL AGAIN HAMPER TEMPERATURES SIGNIFICANTLY.
QUIET WEATHER THROUGH THE FIRST HALF OF NEXT WEEK AS RIDGING SPREADS
ACROSS THE CENTRAL UNITED STATES. WARM SOUTHERLY FLOW SHOULD BUMP
TEMPERATURES BACK INTO THE 40S AND SHOULD MELT SOME OF THE SNOWPACK.
THE CONCERN COULD THEN TURN TO FOG POTENTIAL IN THE MIDWEEK
TIMEFRAME.
WHILE STILL EARLY...WE WILL HAVE TO KEEP AN EYE ON A DEEP UPPER
THROUGH DIGGING INTO THE SOUTHWESTERN US THIS WEEK. THIS SYSTEM
COULD BRING MESSY WEATHER INTO THE MIDDLE OF THE COUNTRY FOR THE
THANKSGIVING HOLIDAY. MODELS SEEM TO AGREE THAT A COLD FRONT WILL
SURGE THROUGH THE REGION LATE WEDNESDAY INTO THURSDAY. CONSIDERABLE
UPPER LIFT MAY SPREAD ACROSS THE REGION WITH THE H850 BOUNDARY
LINGERING OVER THE COLDER SFC AIR. THIS SOLN COULD PRODUCE A MYRIAD
OF WINTRY WEATHER IN THE LOCAL AREA BY THANKSGIVING AND THE DAY
AFTER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1120 AM CST FRI NOV 20 2015
HEAVY SNOW BAND ACROSS THE AREA AFFECTING I-90 AND SOUTH. VFR
CONDITIONS SHOULD PREVAIL ACROSS EASTERN SOUTH DAKOTA NORTH OF
HIGHWAY 34. INTENSE BAND OF SNOWFALL IS EXPECTED TO DECREASE NEAR
SIOUX FALLS...BY 20 Z...AND DIMISH TO FLURRIES WITHIN A FEW HOURS.
FURTHER TO THE SOUTH...SECOND BAND OF FRONTOGENESIS IS EXPECTED TO
DEVELOP AND CREATE GREATLY REDUCED CONDITIONS ALONG THE HIGHWAY 20
CORRIDOR...INCLUDING KSUX. THESE CONDITIONS WILL IMPROVE THROUGH
THE EVENING HOURS TONIGHT. WIDESPREAD VFR CONDITIONS ARE EXPECTED
ON SATURDAY.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR SDZ063>071.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR SDZ050-
057>061.
WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR SDZ062.
MN...WINTER WEATHER ADVISORY UNTIL 9 PM CST THIS EVENING FOR MNZ089-
090-098.
IA...WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR IAZ001>003-
012-013-020.
WINTER STORM WARNING UNTIL MIDNIGHT CST TONIGHT FOR IAZ014-021-
022-031-032.
NE...WINTER STORM WARNING UNTIL 9 PM CST THIS EVENING FOR NEZ013-014.
&&
$$
SHORT TERM...JM
LONG TERM...DUX
AVIATION...
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
513 AM CST FRI NOV 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CST FRI NOV 20 2015
PRESENT RADAR SHOWING DEVELOPING SNOW BAND FROM SOUTHWESTERN SOUTH
DAKOTA TO NORTH CENTRAL NEBRASKA VERY EARLY THIS MORNING...THOUGH
NOT SEEING ANY SNOW REACHING THE GROUND ON THE EASTERN EXTENT OF THE
BAND WITH DRY LOW LEVEL AIR IN PLACE. THIS AREA OF SNOW LOOKS TO BE
COLLOCATED WELL WITH MODEL 700 MB FRONTOGENESIS FIELDS. STILL LOOKING
AT A DECENT SNOW EVENT ACROSS THE AREA TODAY WITH STRENGTHENING MID
LEVEL FRONTOGENESIS AND UPPER LEVEL LIFT AIDED BY A JET STREAK
SITUATED THROUGH NORTHERN SOUTH DAKOTA INTO MINNESOTA. MODELS IN
FAIRLY DECENT AGREEMENT ON A STRONG FRONTOGENETIC BAND DEVELOPING
INTO SOUTH CENTRAL SOUTH DAKOTA IN THE EARLY MORNING...THEN
SPLITTING TO THE NORTH AND SOUTH BY LATE MORNING...WITH THE SOUTHERN
BAND BECOMING DOMINATE OVER NORTHWESTERN IOWA BY AFTERNOON AS
OPTIMUM 500-300 MB DIV Q SLIDES THROUGH SOUTHERN SOUTH DAKOTA AND
NEBRASKA DURING THAT TIME FRAME. THIS SCENARIO POINTS TO HEAVY SNOW
DEVELOPING SOUTH OF INTERSTATE 90 DURING THE DAY...WITH AMOUNTS
DECREASING RAPIDLY TO THE NORTH WHERE DRIER AIR WILL BE GREATER AND
FORCING IS LESS. WHAT IS SOMEWHAT DISTURBING IS THAT MOST RECENT
MODEL RUNS...INCLUDING THE RAP AND HRRR ARE TRENDING FARTHER TO THE
NORTH WITH THE MORNING PERIOD SNOWFALL IN THE INITIAL FRONTOGENETIC
BAND...PLACING IT RIGHT ALONG THE INTERSTATE 90 CORRIDOR...BEFORE
COLLAPSING IT SOUTHWARD BY AFTERNOON AS EXPLAINED ABOVE. IN
ADDITION...THEY ARE HINTING AT SOME INSTABILITY OF THE FRONT SO
THERE COULD BE A PERIOD OF HEAVIER SNOWFALL IN THIS VICINITY DURING
THE MORNING HOURS. STILL THINKING THE GENERAL HEAVIER SNOW WILL BE
SOUTH OF I90 FOR MOST OF THE DAY...BUT WILL BE SOMETHING TO KEEP AN
EYE ON. WINDS WILL REMAIN ON THE LIGHTER SIDE TODAY...SO BLOWING
SNOW SHOULD NOT BE AN ISSUE. REMAINED BELOW GUIDANCE WITH RESPECT TO
TEMPERATURES...WITH PRECIPITATION AND WET BULBING EFFECTS...SO
LOOKING AT HIGHS JUST EITHER SIDE OF 30 DEGREES. USING SNOW RATIOS
IN THE RANGE OF 11:1 TO 15:1 AND CURRENTLY PROJECTED TOTAL SNOWFALL
AMOUNTS RANGE FROM JUST UNDER AN INCH ALONG THE HIGHWAY 14
CORRIDOR...TO 4 TO 6 INCHES ALONG THE I90 CORRIDOR...TO 6 TO 9
INCHES SOUTH OF THAT AREA...TRENDING HIGHEST TOWARD NORTHWESTERN
IOWA. IN LIGHT OF ALL THE ABOVE REASONING...ISSUED A WINTER WEATHER
ADVISORY ONE STRIP OF COUNTIES FARTHER TO THE NORTH THAN PREVIOUS
FORECAST...ALONG THE I90 CORRIDOR...WITH A WINTER STORM WARNING FOR
AREAS TO THE SOUTH.
BY THIS EVENING THE MIDLEVEL FRONTOGENETIC FORCING SLIDES EASTWARD
INTO NORTH CENTRAL AND NORTHEASTERN IOWA WITH MAXIMUM UPPER LEVEL
DIV Q FOLLOWING SUIT. WITH THAT...WILL SEE SNOW TAPER OFF FROM WEST
TO EAST DURING THE EVENING. MAY GET SOME CLEARING LATER IN THE
NIGHT...AND WENT ON THE LOWER SIDE OF GUIDANCE...ESPECIALLY IN
EXPECTED SNOW COVERED AREAS...WITH OVERNIGHT READINGS IN THE MID
TEENS NORTH TO AROUND 10 SOUTH OF THE I90 CORRIDOR.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 AM CST FRI NOV 20 2015
A DRY FIRST HALF OF THE MEDIUM RANGE FORECAST...WITH MORE UNSETTLED
WEATHER TAKING AIM FOR THE THANKSGIVING HOLIDAY. EARLY ON THIS
WEEKEND...BEHIND TODAYS DEPARTING SNOWSTORM...THE MAIN CONCERN WILL
BE WITH TEMPERATURES. THE FIRST COLD DAY OF THE LATE FALL AND EARLY
WINTER SEASON WILL ARRIVE ON SATURDAY. FRESH SNOW COVER...COMBINED
WITH H850 MB TEMPERATURES -10 TO -14C WILL KEEP TEMPERATURES WELL
BELOW NORMAL THIS WEEKEND. SATURDAYS HIGHS MAY STRUGGLE TO BREAK
FREE FROM THE MID 20S. ON SUNDAY...WE WILL HAVE A RETURN OF
SOUTHWESTERLY BOUNDARY LAYER AND LOW LEVEL FLOW...BUT FRESH SNOW
COVER WILL AGAIN HAMPER TEMPERATURES SIGNIFICANTLY.
QUIET WEATHER THROUGH THE FIRST HALF OF NEXT WEEK AS RIDGING SPREADS
ACROSS THE CENTRAL UNITED STATES. WARM SOUTHERLY FLOW SHOULD BUMP
TEMPERATURES BACK INTO THE 40S AND SHOULD MELT SOME OF THE SNOWPACK.
THE CONCERN COULD THEN TURN TO FOG POTENTIAL IN THE MIDWEEK
TIMEFRAME.
WHILE STILL EARLY...WE WILL HAVE TO KEEP AN EYE ON A DEEP UPPER
THROUGH DIGGING INTO THE SOUTHWESTERN US THIS WEEK. THIS SYSTEM
COULD BRING MESSY WEATHER INTO THE MIDDLE OF THE COUNTRY FOR THE
THANKSGIVING HOLIDAY. MODELS SEEM TO AGREE THAT A COLD FRONT WILL
SURGE THROUGH THE REGION LATE WEDNESDAY INTO THURSDAY. CONSIDERABLE
UPPER LIFT MAY SPREAD ACROSS THE REGION WITH THE H850 BOUNDARY
LINGERING OVER THE COLDER SFC AIR. THIS SOLN COULD PRODUCE A MYRIAD
OF WINTRY WEATHER IN THE LOCAL AREA BY THANKSGIVING AND THE DAY
AFTER.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 507 AM CST FRI NOV 20 2015
SNOW IS EXPECTED TO DEVELOP ACROSS THE AREA THIS
MORNING...WITH HEAVIEST SNOW FROM THE INTERSTATE 90 CORRIDOR AND
SOUTHWARD. SNOW WILL BE HEAVY AT TIMES THROUGH THE
AFTERNOON...WITH MVFR AND IFR CONDITIONS COMMON. AREAS ALONG THE
HIGHWAY 14 CORRIDOR...INCLUDING KHON...WILL BE EFFECTED LESS FROM
THE STORM SYSTEM...THUS CONDITIONS WILL RESIDE MAINLY IN THE VFR
TO UPPER END MVFR RANGE. SNOW WILL TAPER OFF THIS EVENING FROM
WEST TO EAST.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR SDZ063>071.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR SDZ050-
057>061.
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS
EVENING FOR SDZ062.
MN...WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS
EVENING FOR MNZ089-090-098.
IA...WINTER STORM WARNING FROM 9 AM THIS MORNING TO 9 PM CST THIS
EVENING FOR IAZ001>003-012-013-020.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR IAZ014-021-022-031-032.
NE...WINTER STORM WARNING FROM 9 AM THIS MORNING TO 9 PM CST THIS
EVENING FOR NEZ013-014.
&&
$$
SHORT TERM...JM
LONG TERM...DUX
AVIATION...JM
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
355 AM CST FRI NOV 20 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 354 AM CST FRI NOV 20 2015
PRESENT RADAR SHOWING DEVELOPING SNOW BAND FROM SOUTHWESTERN SOUTH
DAKOTA TO NORTH CENTRAL NEBRASKA VERY EARLY THIS MORNING...THOUGH
NOT SEEING ANY SNOW REACHING THE GROUND ON THE EASTERN EXTENT OF THE
BAND WITH DRY LOW LEVEL AIR IN PLACE. THIS AREA OF SNOW LOOKS TO BE
COLLOCATED WELL WITH MODEL 700 MB FRONTOGENESIS FIELDS. STILL LOOKING
AT A DECENT SNOW EVENT ACROSS THE AREA TODAY WITH STRENGTHENING MID
LEVEL FRONTOGENESIS AND UPPER LEVEL LIFT AIDED BY A JET STREAK
SITUATED THROUGH NORTHERN SOUTH DAKOTA INTO MINNESOTA. MODELS IN
FAIRLY DECENT AGREEMENT ON A STRONG FRONTOGENETIC BAND DEVELOPING
INTO SOUTH CENTRAL SOUTH DAKOTA IN THE EARLY MORNING...THEN
SPLITTING TO THE NORTH AND SOUTH BY LATE MORNING...WITH THE SOUTHERN
BAND BECOMING DOMINATE OVER NORTHWESTERN IOWA BY AFTERNOON AS
OPTIMUM 500-300 MB DIV Q SLIDES THROUGH SOUTHERN SOUTH DAKOTA AND
NEBRASKA DURING THAT TIME FRAME. THIS SCENARIO POINTS TO HEAVY SNOW
DEVELOPING SOUTH OF INTERSTATE 90 DURING THE DAY...WITH AMOUNTS
DECREASING RAPIDLY TO THE NORTH WHERE DRIER AIR WILL BE GREATER AND
FORCING IS LESS. WHAT IS SOMEWHAT DISTURBING IS THAT MOST RECENT
MODEL RUNS...INCLUDING THE RAP AND HRRR ARE TRENDING FARTHER TO THE
NORTH WITH THE MORNING PERIOD SNOWFALL IN THE INITIAL FRONTOGENETIC
BAND...PLACING IT RIGHT ALONG THE INTERSTATE 90 CORRIDOR...BEFORE
COLLAPSING IT SOUTHWARD BY AFTERNOON AS EXPLAINED ABOVE. IN
ADDITION...THEY ARE HINTING AT SOME INSTABILITY OF THE FRONT SO
THERE COULD BE A PERIOD OF HEAVIER SNOWFALL IN THIS VICINITY DURING
THE MORNING HOURS. STILL THINKING THE GENERAL HEAVIER SNOW WILL BE
SOUTH OF I90 FOR MOST OF THE DAY...BUT WILL BE SOMETHING TO KEEP AN
EYE ON. WINDS WILL REMAIN ON THE LIGHTER SIDE TODAY...SO BLOWING
SNOW SHOULD NOT BE AN ISSUE. REMAINED BELOW GUIDANCE WITH RESPECT TO
TEMPERATURES...WITH PRECIPITATION AND WET BULBING EFFECTS...SO
LOOKING AT HIGHS JUST EITHER SIDE OF 30 DEGREES. USING SNOW RATIOS
IN THE RANGE OF 11:1 TO 15:1 AND CURRENTLY PROJECTED TOTAL SNOWFALL
AMOUNTS RANGE FROM JUST UNDER AN INCH ALONG THE HIGHWAY 14
CORRIDOR...TO 4 TO 6 INCHES ALONG THE I90 CORRIDOR...TO 6 TO 9
INCHES SOUTH OF THAT AREA...TRENDING HIGHEST TOWARD NORTHWESTERN
IOWA. IN LIGHT OF ALL THE ABOVE REASONING...ISSUED A WINTER WEATHER
ADVISORY ONE STRIP OF COUNTIES FARTHER TO THE NORTH THAN PREVIOUS
FORECAST...ALONG THE I90 CORRIDOR...WITH A WINTER STORM WARNING FOR
AREAS TO THE SOUTH.
BY THIS EVENING THE MIDLEVEL FRONTOGENETIC FORCING SLIDES EASTWARD
INTO NORTH CENTRAL AND NORTHEASTERN IOWA WITH MAXIMUM UPPER LEVEL
DIV Q FOLLOWING SUIT. WITH THAT...WILL SEE SNOW TAPER OFF FROM WEST
TO EAST DURING THE EVENING. MAY GET SOME CLEARING LATER IN THE
NIGHT...AND WENT ON THE LOWER SIDE OF GUIDANCE...ESPECIALLY IN
EXPECTED SNOW COVERED AREAS...WITH OVERNIGHT READINGS IN THE MID
TEENS NORTH TO AROUND 10 SOUTH OF THE I90 CORRIDOR.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 354 AM CST FRI NOV 20 2015
A DRY FIRST HALF OF THE MEDIUM RANGE FORECAST...WITH MORE UNSETTLED
WEATHER TAKING AIM FOR THE THANKSGIVING HOLIDAY. EARLY ON THIS
WEEKEND...BEHIND TODAYS DEPARTING SNOWSTORM...THE MAIN CONCERN WILL
BE WITH TEMPERATURES. THE FIRST COLD DAY OF THE LATE FALL AND EARLY
WINTER SEASON WILL ARRIVE ON SATURDAY. FRESH SNOW COVER...COMBINED
WITH H850 MB TEMPERATURES -10 TO -14C WILL KEEP TEMPERATURES WELL
BELOW NORMAL THIS WEEKEND. SATURDAYS HIGHS MAY STRUGGLE TO BREAK
FREE FROM THE MID 20S. ON SUNDAY...WE WILL HAVE A RETURN OF
SOUTHWESTERLY BOUNDARY LAYER AND LOW LEVEL FLOW...BUT FRESH SNOW
COVER WILL AGAIN HAMPER TEMPERATURES SIGNIFICANTLY.
QUIET WEATHER THROUGH THE FIRST HALF OF NEXT WEEK AS RIDGING SPREADS
ACROSS THE CENTRAL UNITED STATES. WARM SOUTHERLY FLOW SHOULD BUMP
TEMPERATURES BACK INTO THE 40S AND SHOULD MELT SOME OF THE SNOWPACK.
THE CONCERN COULD THEN TURN TO FOG POTENTIAL IN THE MIDWEEK
TIMEFRAME.
WHILE STILL EARLY...WE WILL HAVE TO KEEP AN EYE ON A DEEP UPPER
THROUGH DIGGING INTO THE SOUTHWESTERN US THIS WEEK. THIS SYSTEM
COULD BRING MESSY WEATHER INTO THE MIDDLE OF THE COUNTRY FOR THE
THANKSGIVING HOLIDAY. MODELS SEEM TO AGREE THAT A COLD FRONT WILL
SURGE THROUGH THE REGION LATE WEDNESDAY INTO THURSDAY. CONSIDERABLE
UPPER LIFT MAY SPREAD ACROSS THE REGION WITH THE H850 BOUNDARY
LINGERING OVER THE COLDER SFC AIR. THIS SOLN COULD PRODUCE A MYRIAD
OF WINTRY WEATHER IN THE LOCAL AREA BY THANKSGIVING AND THE DAY
AFTER.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 529 PM CST THU NOV 19 2015
MAIN AVIATION CONCERN IS THE LATE MORNING AND AFTERNOON HOURS ON
FRIDAY...WHEN A BAND OF SNOW WILL MOVE ACROSS THE FORECAST...MOST
ACUTE ALONG INTERSTATE 90 AND SOUTHWARD. THEREFORE HAVE LIFR TO
IFR CONDITIONS FOR THE KFSD AND KSUX TAF SITES...KEEPING KHON AT
MVFR WHO SHOULD BE TOO FAR NORTH TO GET HEAVY SNOW.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL 6 PM CST THIS EVENING FOR SDZ063>071.
WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR SDZ050-
057>061.
WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS
EVENING FOR SDZ062.
MN...WINTER WEATHER ADVISORY FROM 9 AM THIS MORNING TO 9 PM CST THIS
EVENING FOR MNZ089-090-098.
IA...WINTER STORM WARNING FROM 9 AM THIS MORNING TO 9 PM CST THIS
EVENING FOR IAZ001>003-012-013-020.
WINTER STORM WARNING FROM 9 AM THIS MORNING TO MIDNIGHT CST
TONIGHT FOR IAZ014-021-022-031-032.
NE...WINTER STORM WARNING FROM 9 AM THIS MORNING TO 9 PM CST THIS
EVENING FOR NEZ013-014.
&&
$$
SHORT TERM...JM
LONG TERM...DUX
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
217 PM CST FRI NOV 20 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 217 PM CST FRI NOV 20 2015
HAVE BEEN TRYING TO INTEGRATE CURRENT RADAR AND SURFACE
OBSERVATIONS INTO THE FORECAST TO FINE TUNE STORM. BOTTOM LINE IS
THE ADVISORIES AND WARNINGS LOOK ON TRACK FOR LOCATION. WE DID
UPDATE THE START TIME. HAVE LEFT THE END TIME ON SATURDAY AS THE
NORTHWEST WINDS OF 15 TO 25 MPH WILL CAUSE SOME DRIFTING...
ESPECIALLY ON THE HIGHER TERRAIN OF SWRN WI AND NERN IA.
CURRENT SNOW BAND IS IMPRESSIVE WITH AMOUNTS NEAR 15 INCHES NEAR
SIOUX FALLS SD TODAY AND MESSY ROADS EXTENDING NOW INTO PARTS OF
NERN IA UNDER THE SNOW BAND. GIVEN A MODERATE SNOW
RATE IN THE CENTRAL-EASTERN IA SNOW BAND...ACCUMULATING SNOW AND
SLICK ROADS HAPPEN FAIRLY QUICK AFTER ONSET. THIS BAND IS WELL
REPRESENTED BY 600-700 MB FRONTOGENESIS FORCING PER RAP ANALYSIS.
THE BAND SHOULD CONTINUE TO SHIFT NORTHEAST THROUGH EARLY EVENING. PER
VIGOROUS SHORTWAVE TROUGH IN KS/NEB MOVING AT US...THE
FRONTOGENESIS THEN REINVIGORATES A BIT LATER EVENING ON A NE-SW
ARC OVER THE SOUTHERN FORECAST AREA...WITH THE MAIN HEAVY SNOW
BAND NEAR HIGHWAY 20 TO I-80 WITH STRONGER FRONTOGENSIS INDICATED
IN THE SHORT TERM MODELS.
BIG PICTURE REMAINS THE SAME FOR THIS STORM. WE HAVENT CHANGED
THE TOTAL LIQUID FROM THIS STORM MUCH...BUT DO HAVE SOME CONCERNS
WITH SNOW RATIOS IN THE WARNING...ESPECIALLY CLOSER TO DUBUQUE AND
THE SOUTHERN HALF OF THE FAYETTE-CLAYTON-GRANT COUNTIES. THE
LATEST RAP AND 20.12Z NAM/GFS OUTPUT RUN THROUGH THE DENDRITIC
GROWTH ZONE COBB TECHNIQUE SUGGEST RATIOS COULD BE IN THE 20-24 TO
1 RANGE. WE HAVE INCREASED THOSE RATIOS TO 17 TO 1 ACROSS THE
WARNING WITH A 150-200 MB DENDRITE GROWTH ZONE SUGGESTED. THIS
RAISES TOTALS TOWARD A FOOT. WINDS WILL INCREASE ACROSS THE SOUTH
INTO THE 15 TO 25 MPH RANGE SATURDAY FOR A BIT OF DRIFTING SNOW.
MAIN MESSAGE IS THE SAME...WITH POSSIBLY A BIT MORE IMPACT ACROSS
THE FAR SOUTH /IA HIGHWAY 3/ WITH 10-12 INCHES AND SOME DRIFTING
SNOW. BELIEVE ACCUMULATING SNOW WILL REALLY BE SOUTH OF I-90...AND
THE HAZARDS LOOK LIKE THEY ARE PLACED WELL.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 217 PM CST FRI NOV 20 2015
NORTHWEST FLOW CONTINUES WITH A COLD WEEKEND. CONSENSUS
DETERMINISTIC MODEL RUNS FROM 20.12Z AGREED WELL ON A DYNAMIC
SYSTEM SHIFTING THROUGH NERN WI RAPIDLY SUNDAY NIGHT. THIS LOOKS
LIKE IT COULD SPREAD SOME SNOW ACROSS NORTHCENTRAL WI...LEAVING BY
MONDAY.
THE WEEK THEN BEGINS TO WARM AS ANOTHER LONGWAVE TROUGH DIGS IN
THE WEST. BY MID-WEEK PRECIPITATION WORKS INTO THE AREA ON A
MOIST FLOW. A CLOUDY PERIOD WITH POSSIBLY PRECIPITATION TYPE
ISSUES. AT THIS TIME IT APPEARS MAINLY LIKE A RAIN/SNOW SCENARIO
BUT DEPENDING ON HOW MOISTURE ARRIVES...SOME FREEZING DRIZZLE
COULD BE AROUND. THE MAIN IDEA NOW IS WARMING AND PRECIPITATION BY
MID-WEEK INTO THANKSGIVING. CONFIDENCE MODERATE WITH GOOD
CONSENSUS ON THE BIG PICTURE.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1146 AM CST FRI NOV 20 2015
A SNOW BAND HAS SET UP FROM SOUTHEAST SOUTH DAKOTA INTO THE
WATERLOO IA AREA...WITH ALTOSTRATUS SPREADING NORTH INTO THE TAF
SITES NORTH OF THE BAND. THIS SNOW BAND LOOKS TO STAY MOSTLY SOUTH
OF THE TAF SITES THROUGH TONIGHT...BUT ITS NORTHERN EDGE COULD TRY
TO SNEAK IN THIS EVENING...KNOCKING VISIBILITIES DOWN TO MVFR AT
TIMES. ANY ACCUMULATIONS LOOK TO BE LESS THAN 1 INCH. PLAN ON ANY
LIGHT SNOW TO DEPART OVERNIGHT...FOLLOWED BY CLOUDS CLEARING
DURING THE MORNING HOURS.
PLAN ON WINDS TO BECOME NORTHWESTERLY BY THIS EVENING...FOLLOWED
BY AN INCREASE TO 10-15 KT ON SATURDAY AS THE PRESSURE GRADIENT
TIGHTENS OVER THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR WIZ054-061.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO NOON CST SATURDAY
FOR WIZ055.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
SATURDAY FOR WIZ053.
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR MNZ094-095.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
SATURDAY FOR MNZ096.
IA...WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR IAZ008-018-019.
WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR IAZ009.
WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR IAZ010-011-030.
WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR IAZ029.
&&
$$
SHORT TERM...BAUMGARDT
LONG TERM...BAUMGARDT
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1146 AM CST FRI NOV 20 2015
.UPDATE...
ISSUED AT 1117 AM CST FRI NOV 20 2015
RADAR IMAGERY AS OF 17Z SHOWED A MESOSCALE SNOW BAND FROM NEAR FSD
TO ALO/VTI...GRADUALLY MARCHING NORTHEASTWARD ON ITS EASTERN
FLANK. THIS BAND CORRELATES WELL WITH 700-600MB FRONTOGENESIS
SHOWN IN THE RAP. THE EASTERN SIDE OF THE BAND HAS HAD TO OVERCOME
LOWER LEVEL DRY AIR...BUT ONCE IT DOES...VISIBILITIES QUICKLY
TANK. IN MARSHALLTOWN IA...THE VISIBILITY DROPPED FROM 10 MILES TO
3/4 IN LESS THAN 1 HOUR AS THE BAND MOVED THROUGH. OVER THE
NORTHWEST PART OF IOWA INTO SOUTHEAST SOUTH DAKOTA...WHERE THE
BAND HAS BEEN STAYING PUT THE LONGEST...SNOWFALL AMOUNTS OF 4 TO 6
INCHES HAVE ALREADY OCCURRED.
20.12Z GFS/NAM/REGIONAL CANADIAN AND 20.15Z RAP/BOULDER HRRR ALL
POINT TO THE FRONTOGENESIS BAND LIFTING INTO NORTHEAST IA AND FAR
SOUTHWEST WI OVER THE COURSE OF THE AFTERNOON...ABOUT 3 HOURS
SOONER THAN PREVIOUSLY FORECAST. AS A RESULT...HAVE STARTED THE
WARNING TIMES ABOUT 3 HOURS EARLIER. ADDITIONALLY...IT APPEARS THE
STRONGEST FORCING WITH THE BAND SLOWS UP...ALONG AN AXIS BETWEEN
HIGHWAYS 20 AND 30. THE AFOREMENTIONED MODELS ALL BOOSTED UP QPF
IN THIS REGION AND HAVE MADE A SIMILAR ADJUSTMENT...BUT DID NOT GO
AS HIGH YET WITH LOW LEVEL DRY AIR CONCERNS IN OUR AREA. MODEL
SOUNDINGS WITHIN THIS STRONGEST FORCING DEPICT ANYWHERE FROM
150-200MB OF DENDRITIC GROWTH ZONE WITH VERY STRONG
LIFT...SUPPORTING SNOW TO WATER RATIOS APPROACHING 20 TO 1.
THEREFORE ALSO BOOSTED SNOW TO WATER RATIOS AND SIMILAR TO
QPF...PLAYED A BIT MORE CONSERVATIVE. NET RESULT IS THAT WE ARE
NOW LOOKING AT 8-12 INCHES FROM FLOYD COUNTY INTO GRANT...HIGHEST
THE CLOSER YOU GET TO HIGHWAY 20.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 330 AM CST FRI NOV 20 2015
FIRST WINTER STORM OF THE YOUNG WINTER SEASON...AND FORECAST FOCUS
IS SQUARELY ON THAT.
UPPER LEVEL TROUGH AXIS SLATED TO SWING ACROSS THE UPPER MISSISSIPPI
RIVER VALLEY SAT...WITH AN EMBEDDED RIPPLE IN THE FLOW LEADING THE
CHARGE INTO THE AREA LATER THIS AFTERNOON/TONIGHT. NORTH-SOUTH
RUNNING X-SECTION SHOWS STRONG/SLOPING FRONTOGENETIC
RESPONSE...STRONGEST ACROSS CENTRAL-NORTHERN IA AND NORTHERN ILL/FAR
SOUTHERN WI. DON/T SEE MUCH -EPV TO ENHANCE BANDING...BUT A 130 KT
UPPER LEVEL JET WILL ENHANCE THE LIFT VIA THE LEFT EXIT REGION.
HEFTY SWATH OF LOW LEVEL THERMODYNAMICS AND QG CONVERGENCE COME WITH
THE SHORTWAVE. NO LACK FOR FORCING FOR SNOW.
SATURATION WILL BE LIMITING FACTOR IN EXTENT OF THE
PCPN...ESPECIALLY ON ITS NORTHERN FRINGES. BOTH THE GFS AND NAM
BRING THE DEEPEST SATURATION JUST SOUTH OF I-90...PER TIME/HEIGHT X-
SECTIONS AND BUFKIT SOUNDINGS. FACTORING IN WHAT WILL LIKELY BE SOME
BANDING IN THE WEST-EAST RUNNING SWATH OF SNOW AND THOSE DRIER LOW
LEVELS...THERE COULD BE A RATHER QUICK FALL OFF IN
ACCUMULATIONS...SNOW RATES...AND EVEN WHERE SNOW FALLS ON THE
NORTHERN EDGE. WILL PAINT QPF/SNOW AMOUNTS AND CHANCES WITH THIS IN
MIND. SOME MESO MODELS SUGGESTING THE NORTHERN PORTION OF THE SNOW
COULD SLIDE SOUTH OF I-90.
AS FOR AMOUNTS...DENDRITIC ZONE GROWTH REGION AROUND 6 KFT AT DBQ AT
THE ONSET OF THE SNOW...DECREASING THROUGH THE NIGHT. MUCH LOWER TO
THE NORTH. SREF DATA SHOWS HUGE SPREADS...OVER 20 INCHES BETWEEN TOP
AND BOTTOM AT LOCATIONS LIKE DBQ. COBB OUTPUT HAS BEEN FAIRLY STEADY
IN THE GFS/NAM DOWN SOUTH THOUGH...SUGGESTING A FOOT FOR DBQ. SPREAD
IN THE SREF PLUMES LOWERS CONFIDENCE A BIT...BUT STEADINESS IN COBB
PROPS IT UP. GOING 5 TO 8 INCHES ACROSS NORTHEAST IA AND SOUTHWEST
WI AT THE MOMENT. SOME LOCALLY HIGHER AMOUNTS ACROSS THE FAR SOUTH
ARE POSSIBLE - ALL DEPENDING ON WHERE THE MORE INTENSE BANDS SET UP.
TO THE NORTH...AMOUNTS ARE MORE PROBLEMATIC. LOCATIONS ALONG I-90
FROM RST-LSE COULD SEE AN INCH OR SO...OR NOTHING. WILL KEEP
OPTIMISTIC WITH SOME ACCUMULATIONS RIGHT NOW...BUT A SHIFT TO LITTLE
OR NO ACCUMS COULD VERY WELL OCCUR. WITH THAT IN MIND...WILL LEAVE
THE I-90 CORRIDOR OUT OF A WINTER WEATHER ADVISORY FOR THIS MOMENT.
LET TRENDS AND NEXT MODEL RUN CONFIRM THE NEED TO MOVE THE ADV
NORTH. WILL INCLUDE A TIER BELOW THAT...AND THEN ALL WARNING FOR
NORTHEAST IA AND SOUTHWEST WI. SOME LOCATIONS THERE WON/T HIT
TRADITIONAL CRITERIA...BUT WITH IT THE FIRST SIGNIFICANT
SNOWFALL...IMPACTS WILL BE HIGH.
.LONG TERM...(SATURDAY THROUGH THANKSGIVING)
ISSUED AT 330 AM CST FRI NOV 20 2015
SHORTWAVE TROUGH LOOKS TO DROP OUT OF CANADA SUNDAY...SPINNING
ACROSS THE UPPER MISSISSIPPI RIVER VALLEY SUNDAY NIGHT-MONDAY.
STRONG QG CONVERGENCE RESPONSE THROUGH THE LEVELS WITH THE
FEATURE...WITH A HEFTY LEADING PUSH OF LOW LEVEL THERMODYNAMICS.
AMPLE LIFT FOR PCPN PRODUCTION. MODELS KEEP MOST OF THE QPF ACROSS
NORTHERN PARTS OF MN/WI...WHERE THE SATURATION IS DEEPEST. ITS LACK
OF RH IS PREVENTING THE MODELS FROM CHURNING OUT MORE QPF...AND IF
THIS PROGGED LACK OF MOISTURE CAN BE OVERCOME...PCPN WOULD GO FROM
CHANCES IN THE NORTH...TO WIDESPREAD LIKELY. ITS A SYSTEM THAT BEARS
WATCHING...AND COULD PACK A BIT MORE OF A PUNCH THEN MODELS ARE
CURRENTLY INDICATING.
MODELS IN GOOD AGREEMENT WITH QUICKLY TRANSITIONING TO BROAD UPPER
LEVEL RIDGING...THEN SOUTHWEST FLOW FOR TUE-THU. TEMPS AT OR ABOVE
THE SEASONABLE NORMALS TUE-THU. WITH THE SOUTHWEST FLOW WILL COME A
SLUG OF GULF MOISTURE. 850 MB TRANSPORT INCREASES DURING THE
PERIOD...STRONGEST ACROSS THE FORECAST AREA THU AFTERNOON/EVENING.
PWS EXCEED 1 INCH IN THE GFS...WITH NAEFS ANOMALIES HOVERING AROUND
+1. A SFC FRONT WILL BE ENCROACHING FROM THE WEST...AHEAD OF SOME
UPPER LEVEL ENERGY SPITTING OUT OF A DESERT SW TROUGH AND A
SHORTWAVE MOVING ALONG THE CANADIAN/US BORDER. DECENT FRONTOGENETIC
RESPONSE AND SOME QG CONVERGENCE WILL HAVE A HAND IN WORKING ON THAT
MOISTURE TO PRODUCE AREAS OF PRECIPITATION...MOSTLY IN THE FORM OF
RAIN. SOME HINTS IN THE GFS/ECMWF THAT SOME SNOW WOULD BECOME LIKELY
ON THE BACKSIDE OF THE SYSTEM...WITH THE EC A BIT MORE BULLISH ON
THE POTENTIAL. CAN/T RULE OUT THE POTENTIAL FOR A WINTRY MIX EITHER.
HARD TO SAY THIS FAR OUT. WILL LET CONSENSUS SOLUTION PAINT THE PCPN
CHANCES AND REFINE DETAILS AS WE GET CLOSER TO THE THANKSGIVING
HOLIDAY. SUFFICE TO SAY...THERE LOOKS TO BE SOME PCPN IMPACTS FOR
THE HOLIDAY...INCLUDING BLACK FRIDAY SHOPPERS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1146 AM CST FRI NOV 20 2015
A SNOW BAND HAS SET UP FROM SOUTHEAST SOUTH DAKOTA INTO THE
WATERLOO IA AREA...WITH ALTOSTRATUS SPREADING NORTH INTO THE TAF
SITES NORTH OF THE BAND. THIS SNOW BAND LOOKS TO STAY MOSTLY SOUTH
OF THE TAF SITES THROUGH TONIGHT...BUT ITS NORTHERN EDGE COULD TRY
TO SNEAK IN THIS EVENING...KNOCKING VISIBILITIES DOWN TO MVFR AT
TIMES. ANY ACCUMULATIONS LOOK TO BE LESS THAN 1 INCH. PLAN ON ANY
LIGHT SNOW TO DEPART OVERNIGHT...FOLLOWED BY CLOUDS CLEARING
DURING THE MORNING HOURS.
PLAN ON WINDS TO BECOME NORTHWESTERLY BY THIS EVENING...FOLLOWED
BY AN INCREASE TO 10-15 KT ON SATURDAY AS THE PRESSURE GRADIENT
TIGHTENS OVER THE REGION.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO NOON CST
SATURDAY FOR WIZ054-061.
WINTER STORM WARNING FROM 6 PM THIS EVENING TO NOON CST SATURDAY
FOR WIZ055.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
SATURDAY FOR WIZ053.
MN...WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO 6 AM CST
SATURDAY FOR MNZ094-095.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO NOON CST
SATURDAY FOR MNZ096.
IA...WINTER STORM WARNING UNTIL 6 AM CST SATURDAY FOR IAZ008-018-019.
WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO 6 AM CST
SATURDAY FOR IAZ009.
WINTER STORM WARNING FROM 3 PM THIS AFTERNOON TO NOON CST
SATURDAY FOR IAZ010-011-030.
WINTER STORM WARNING UNTIL NOON CST SATURDAY FOR IAZ029.
&&
$$
UPDATE...AJ
SHORT TERM...RIECK
LONG TERM....RIECK
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
254 PM MST FRI NOV 20 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 253 PM MST FRI NOV 20 2015
THE MAIN SHORTWAVE TROUGH AXIS CONTINUES TO MOVE EASTWARD ACROSS
THE CWA THIS AFTERNOON. SNOW HAS BEEN GRADUALLY DECREASING TO THE
WEST OF THE LARAMIE RANGE IN RESPONSE TO NVA AND INCREASING LARGE
SCALE SUBSIDENCE ON THE BACK SIDE OF THE SYSTEM...SO NOT EXPECTING
MUCH FOR ADDITIONAL ACCUMULATIONS OUT THERE. INFRARED SATELLITE IS
STILL SHOWING SOME COOLING CLOUD TOPS ACROSS EAST CENTRAL WY INTO
THE NORTHERN NE PANHANDLE...MAINLY WITH THE UPSLOPE ALONG THE PINE
RIDGE. THIS SUGGESTS WIDESPREAD SNOW WILL LIKELY CONTINUE THROUGH
AT LEAST EARLY EVENING BEFORE UPPER-LEVEL SUPPORT WEAKENS. EXPECT
TO SEE SOME LINGERING SNOW SHOWERS OVERNIGHT...BUT POPS SHOULD BE
NIL ACROSS THE CWA BY 09Z.
WINTER STORM WARNINGS FOR THE SNOWY/SIERRA MADRE MOUNTAIN RANGES
WILL REMAIN UNCHANGED. SNOWFALL ESTIMATES FROM SEVERAL SNOTEL OBS
INDICATE AROUND 1 TO 2 FEET WITH A FEW ISOLATED TOTALS AROUND 30
INCHES OVER THE LAST 24 HOURS. ANOTHER INCH OR TWO IS POSSIBLE IN
THE NEXT FEW HOURS. DOWNGRADED THE ARLINGTON WARNING TO A WINTER
WEATHER ADVISORY AS CONDITIONS HAVE IMPROVED...BUT LOW VISIBILITY
CONTINUES IN FALLING/BLOWING SNOW. HAZARDOUS WINTER CONDITIONS ARE
STILL ONGOING OVER THE I80 SUMMIT WITH WYDOT CONTINUING TO REPORT
CLOSURES DUE TO ACCIDENTS. A WINTER WEATHER ADVISORY WILL CONTINUE
UNTIL 11 PM. FINALLY...WILL KEEP THE WINTER WEATHER ADVISORY GOING
FOR THE PINE RIDGE AREA THROUGH THE EVENING. CANCELLED CONVERSE CO
AND THE NORTHERN LARAMIE RANGE EARLY AS THE UPPER-LEVEL SUPPORT IS
NOW EXITING TO THE EAST.
VERY COLD TONIGHT FOR MUCH OF THE AREA. LOCATIONS WHICH RECEIVED
MORE THAN A COUPLE INCHES OF SNOW TODAY WILL LIKELY BE COLDER THAN
SURROUNDING AREAS...ESPECIALLY IF CLOUDS/PRECIP CLEAR OUT EARLIER
THAN EXPECTED. OFFICIAL FORECAST LOW TEMPERATURES ARE SEVERAL DEG
BELOW CONSENSUS MOS GUIDANCE. COULD SEE SUB-ZERO READINGS IN THE
HIGH VALLEYS SUCH AS LARAMIE. WIDESPREAD WIND CHILLS BETWEEN -5 F
AND -20 F CAN BE EXPECTED BY SUNRISE SAT. DRY NORTHWEST FLOW ALOFT
AND WARMING THERMAL PROFILES WILL YIELD IMPROVING CONDITIONS AREA
WIDE ON SATURDAY WITH NO CHANCES FOR PRECIP. BREEZY ALONG AND WEST
OF THE LARAMIE RANGE WITH CAG-CPR GRADIENTS AROUND 50 METERS...BUT
ATTM DO NOT EXPECT WIND HIGHLIGHTS FOR THE WIND PRONE AREAS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 253 PM MST FRI NOV 20 2015
...WINTER STORM POSSIBLE FOR THE THANKSGIVING HOLIDAY...
WE WILL BE UNDER NORTHWEST FLOW SUNDAY. RIDGE AXIS OFF TO THE WEST
ALONG THE WEST COAST. FAIRLY WARM AND DRY THROUGH TUESDAY WITH
GRADUALLY WARMING TEMPERATURES EACH DAY. UPPER RIDGE AXIS MOVES
OVER WYOMING MONDAY AFTERNOON WITH 700MB TEMPERATURES MAXING OUT
ABOVE FREEZING.
INCREASING WESTERLY WINDS TUESDAY AS RIDGE AXIS MOVES EAST.
DOWNSLOPING WINDS OFF THE LARAMIE RANGE COULD VERY WELL PUSH HIGHS
INTO THE 60S TUESDAY.
VERY GOOD AGREEMENT BETWEEN THE GFS AND ECMWF ON TIMING...PRECIP
PLACEMENT AND TOTALS ON A PACIFIC STORM SYSTEM MOVING INTO
WYOMING. WE SHOULD BEGIN SEEING PRECIP OUT WEST IN CARBON COUNTY
AS EARLY AS WEDNESDAY MORNING...MORE LIKELY WEDNESDAY EVENING.
ASSOCIATED COLD FRONT MOVES THROUGH SOUTHEAST WYOMING WEDNESDAY
MORNING WITH 700MB TEMPERATURES FALLING TO -12 TO -14C WEDNESDAY
AFTERNOON. THIS WILL BE ALL SNOW WITH THESE VERY COLD 700MB
TEMPERATURES.
IF TRAVELING THROUGH SOUTHEAST WYOMING WEDNESDAY INTO THURSDAY
NEXT WEEK...YOU WILL DEFINITELY WANT TO STAY UP ON THE FORECAST
FOR THIS PART OF THE COUNTRY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1029 AM MST FRI NOV 20 2015
SECOND DISTURBANCE BEGINNING TO MOVE INTO CENTRAL WYOMING LATE
THIS MORNING....MOVING EAST SOUTHEAST. THIS DISTURBANCE WILL BRING
ANOTHER SHOT OF WIDESPREAD LIGHT SNOW AND IFR CONDITIONS TO OUR
AIRPORTS. QUESTION IS...HOW FAR SOUTH WILL THE SNOW/IFR CONDITIONS
GET. FOLLOWED HRRR GUIDANCE THAT KEEPS IFR/LIFR CONDITIONS GOING
FOR MOST OF THE PANHANDLE AND HERE AT KCYS THROUGH THE AFTERNOON.
UPSLOPE WINDS AT KLAR SHOULD CONTINUE TO CREATE IFR CONDITIONS IN
SNOW FOR THERE.
&&
.FIRE WEATHER...
ISSUED AT 253 PM MST FRI NOV 20 2015
MINIMAL FIRE WEATHER CONCERNS FOR MOST AREAS AS RECENT SNOWFALL
AND COLDER TEMPERATURES WILL KEEP FIRE WEATHER CONCERNS AT BAY.
SNOW TO END ACROSS THE AREA BY SATURDAY MORNING WITH A DRY PERIOD
AHEAD THROUGH AT LEAST MID WEEK. NEXT CHANCES FOR SNOW APPEAR TO
BE WEDNESDAY NIGHT INTO THANKSGIVING TIMEFRAME.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ110-112-
114.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR
WYZ101>103-106-116-117.
NE...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR NEZ002-
095.
&&
$$
SHORT TERM...CLH
LONG TERM...GCC
AVIATION...GCC
FIRE WEATHER...GCC
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
1033 AM MST FRI NOV 20 2015
.SHORT TERM...(TODAY THROUGH SUNDAY AFTERNOON)
ISSUED AT 338 AM MST FRI NOV 20 2015
TODAY...QUITE SURPRISED THAT WINDS HAVE NOT INCREASED AS MUCH AS
EARLIER ANTICIPATED ACROSS THE SOUTHERN LARAMIE RANGE. WATCHING
TRENDS THE PAST FEW HOURS...AND SINCE THE WORK HEIGHT PRODUCT
SHOWS LOWERING HEIGHT DIFFERENCES THE NEXT FEW HOURS...WILL LIKELY
CANCEL THE HIGH WIND WARNING EARLY FOR THE INTERSTATE 80 SUMMIT.
WATCHING SATELLITE AND RADAR TRENDS...A BAND OF LIGHT TO MODERATE
SNOW CONTINUES TO DESCEND SOUTHWARD ACROSS OUR NORTHERN
COUNTIES...AND WITH PROGGED QPF...STILL EXPECTING AT LEAST 1 TO 3
INCHES OF SNOW OVER OUR NORTHERN COUNTIES FROM DOUGLAS TO CHADRON
AND NOT ENOUGH CONFIDENCE TO DROP THE WINTER WEATHER ADVISORY THERE
AS WOULD NOT BE SURPRISED TO SEE A POWDERY SNOWFALL OF AROUND 3
INCHES IN A FEW LOCATIONS THERE.
AS FOR THE WINTER STORM WARNING OVER OUR SNOWY AND SIERRA MADRE
RANGES AND THE NORTHERN SNOWY FOOTHILLS...SNOW HAS BEEN SLOW TO
DEVELOP AND INCREASE IN INTENSITY THERE. HOWEVER...BASED ON THE
MODEL PROGS...STILL BELIEVE THERE WILL BE A PERIOD OF 6 TO 12 HOURS
OF AT LEAST MODERATE SNOW ALONG WITH STRONG GUSTY WINDS PRODUCING
LIMITED VISIBILITIES TO WARRANT CONTINUING THE WINTER STORM WARNING
EVEN THOUGH TOTAL SNOWFALL ACCUMULATIONS WILL LIKELY BE LESS THEN
EARLIER ANTICIPATED.
TONIGHT...CLEARING AND COLD WITH FRESH SNOW COVER AND LIGHT
WINDS...PRODUCING LOW TEMPERATURES IN THE SINGLE DIGITS AND LOWER
TEENS.
SATURDAY...WITH FRESH SNOW COVER AT MOST LOCATIONS AND A COLD
AIRMASS OVERHEAD...TEMPERATURES WILL STRUGGLE TO CLIMB TO ABOVE
FREEZING...THOUGH FORTUNATELY WINDS WILL BE RELATIVELY LIGHT.
SATURDAY NIGHT/SUNDAY...NOT QUITE AS COLD OVERNIGHT AS THE AIRMASS
BEGINS TO MODERATE AND LOW LEVEL MIXING AIDS IN KEEPING IT SLIGHTLY
WARMER. WARMING TREND BEGINS IN EARNEST WITH 700 MB TEMPERATURES
RISING TO NEAR -1 CELSIUS AND WITH DOWNSLOPE WEST WINDS SO
WIDESPREAD 40S EXPECTED EAST OF INTERSTATE 25 WITH ABOVE FREEZING
MAXIMUM TEMPERATURES WEST OF I-25.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 411 AM MST FRI NOV 20 2015
TRANQUIL WEATHER WILL BE IN PLACE FOR MUCH OF THE LONG TERM
FORECAST PERIOD UNDER THE INFLUENCE OF UPPER LEVEL RIDGING.
TEMPERATURES WILL START OFF ON THE CHILLY SIDE SUNDAY MORNING WITH
SINGLE DIGITS AND TEENS ACROSS THE AREA. TEMPERATURES WILL
MODERATE INTO THE 30S AND 40S BY SUNDAY AFTERNOON. WARMER WEATHER
WILL SPREAD INTO THE AREA FOR MONDAY AND TUESDAY AS THE RIDGE AXIS
SHIFTS ACROSS THE ROCKIES. ONE MORE NICE DAY IS POSSIBLE WEDNESDAY
BUT THAT DEPENDS ON HOW FAST THE NEXT UPPER LEVEL TROUGH
PROGRESSES EASTWARD ACROSS THE WESTERN CONUS. WILL CERTAINLY SEE
INCREASING CLOUD COVER BUT THE BEST CHANCES FOR PRECIPITATION MAY
HOLD OFF UNTIL THURSDAY. EXTENDED MODELS DIFFER IN THE DETAILS BUT
GENERALLY SHOW A LARGE CUTOFF LOW OVER IMPACTING THE FORECAST AREA
THROUGH LATE NEXT WEEK AND POTENTIAL INTO NEXT WEEKEND.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1029 AM MST FRI NOV 20 2015
SECOND DISTURBANCE BEGINNING TO MOVE INTO CENTRAL WYOMING LATE
THIS MORNING....MOVING EAST SOUTHEAST. THIS DISTURBANCE WILL BRING
ANOTHER SHOT OF WIDESPREAD LIGHT SNOW AND IFR CONDITIONS TO OUR
AIRPORTS. QUESTION IS...HOW FAR SOUTH WILL THE SNOW/IFR CONDITIONS
GET. FOLLOWED HRRR GUIDANCE THAT KEEPS IFR/LIFR CONDITIONS GOING
FOR MOST OF THE PANHANDLE AND HERE AT KCYS THROUGH THE AFTERNOON.
UPSLOPE WINDS AT KLAR SHOULD CONTINUE TO CREATE IFR CONDITIONS IN
SNOW FOR THERE.
&&
.FIRE WEATHER...
ISSUED AT 338 AM MST FRI NOV 20 2015
MINIMAL CONCERNS BASED ON PROJECTED WINDS AND
HUMIDITIES FOR THE NEXT SEVERAL DAYS.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ110-112-
114.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR
WYZ101>103.
NE...WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR NEZ002-
095.
&&
$$
SHORT TERM...RE
LONG TERM...SML
AVIATION...GCC
FIRE WEATHER...RUBIN
AREA FORECAST DISCUSSION
NWS NEW YORK NY
103 AM EST SUN NOV 22 2015
.SYNOPSIS...
A WARM FRONT PASSES TONIGHT...FOLLOWED BY A COLD FRONT EARLY SUNDAY.
LOW PRESSURE RIDES ALONG THE FRONT PASSING JUST EAST SUNDAY NIGHT. HIGH
PRESSURE BUILDS IN FROM THE SOUTH EARLY THROUGH MIDWEEK...EVENTUALLY
MOVING INTO THE CANADIAN MARITIMES TOWARDS THE END OF THE WEEK. A
COLD FRONT WILL APPROACH FRIDAY NIGHT AND MOVE ACROSS NEXT
SATURDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
LINE OF SHOWERS ASSOCIATED WITH APPROACHING COLD FRONT IS SITUATED
OVER WESTERN NY AND CENTRAL PA AS OF 06Z. CURRENT FORECAST
GUIDANCE SUCH AS THE HRRR...WHICH HAS A GOOD HANDLE ON THE CURRENT
POSITION OF THIS LINE...SUGGESTS THAT THE LINE OF SHOWERS WEAKENS
AS IT CONTINUES ITS APPROACH TOWARD THE AREA. THE RUC AND NARRE
ARE IN LINE WITH SCENARIO...SO HAVE GONE WITH SLIGHT CHANCE
EVERYWHERE THROUGH MUCH OF THE OVERNIGHT PERIOD. OTHERWISE...NO
MAJOR CHANGES MADE TO THE FORECAST.
LOW LEVEL FLOW AROUND THE HIGH IS ADVECTING LOWER CLOUDS ACROSS
THE AREA THIS EVENING. LATEST MESOSCALE MODELS SUGGEST LOW CLOUD
MOVEMENT/EXPANSION ACROSS NYC METRO AND LONG ISLAND NORTHWARD
ACROSS THE LOWER HUDSON VALLEY AND INTO SOUTHERN CT THROUGH THE
NIGHT.
THEN...UPSTREAM SHORTWAVE AND ASSOCIATED SFC LOW PIVOT ACROSS THE
GREAT LAKES REGION INTO CANADA. A WARM FRONT WILL APPROACH LATER
TONIGHT. AS THE LOWER LEVELS SATURATE AND WEAK LIFT IS REALIZED...
SOME LIGHT SHOWERS WILL BE POSSIBLE BUT NOT UNTIL LATE TONIGHT.
VEERING WINDS TO THE SE SHOULD PREVENT TEMPS FROM DROPPING MUCH MORE
THAN EVENING READINGS. GENERALLY EXPECT LOWS IN THE UPPER 30S WELL
INLAND TO NEAR 50 AT THE COAST...WITH TEMPERATURE READINGS NEARLY
STEADY OR SLIGHTLY RISING OVERNIGHT.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
MODELS ARE IN GENERAL AGREEMENT THIS TIME FRAME AS UPPER TROUGH AXIS
APPROACHES IN TIME...AND SFC COLD FRONT QUICKLY MOVES ACROSS THE
AREA SUNDAY MORNING.
AS THE UPPER STEERING FLOW BECOMES NEARLY PARALLEL WITH THE FRONT
(MORE OF A NEGATIVE TILT ORIENTATION)...THE FRONT LOOKS TO SLOW DOWN
TO THE EAST OF THE AREA. MODELS GENERALLY AGREE ON THIS.
HOWEVER...DIFFERENCES ARE NOTED IN PLACEMENT OF SFC LOW AS IT
RIDES ALONG THE FRONT...DUE TO SUBTLE DIFFERENCES ALOFT.
ANY SHOWERS EARLY SUNDAY MOVE EAST...WITH ADDITIONAL SHOWERS
DEVELOPING ALONG OF AND AHEAD OF THE FRONT AS ATLANTIC MOISTURE IS
PICKED UP. AT THIS TIME...EXPECT MOST OF THIS PRECIP REMAINS TO THE
EAST...BUT POPS WERE RAISED SOME...PARTICULARLY FOR THE EASTERN
PORTION OF THE CWA. WOULD NOT BE SURPRISED IF POPS ARE RAISED
FURTHER FOR EASTERN LONG ISLAND IF SUBSEQUENT MODEL RUNS SUPPORT
THIS IDEA.
TEMPS ON SUNDAY WILL REMAINS AROUND NORMAL LEVELS. CAA BEHIND THE
FRONT THOUGH WILL ALLOW READINGS TO FALL BACK TO THE LOWER 30S NEAR
THE COAST...AND 20S ELSEWHERE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
MONDAY STARTS A TRANSITION PERIOD TO MORE RIDGING ALOFT WITH A
MODERATION OF THE AIRMASS ACROSS THE LOCAL REGION. THE JET STREAM
WILL BE RISING FARTHER NORTH AS THE WEEK PROGRESSES WITH A MILD
AIRMASS MOVING IN PLACE. THE LOCAL WEATHER REMAINS DRY IN MUCH OF
THE LONG TERM DURING THE NEW WEEK WITH A RISING TREND TO
TEMPERATURES. HIGHS FORECAST ARE BETWEEN 5 AND 10 DEGREES BELOW
NORMAL MONDAY AND THEN JUST A FEW DEGREES BELOW NORMAL TUESDAY AND
NEAR NORMAL WEDNESDAY. THEN MAX TEMPERATURES ARE FORECAST BETWEEN
5 AND 10 DEGREES ABOVE NORMAL FOR THURSDAY AND FRIDAY. MAX
TEMPERATURES RETURN TO NEAR NORMAL NEXT SATURDAY.
THIS COMES FROM A HIGH PRESSURE AREA HAVING A SOURCE IN THE SOUTH.
THIS MOVES DIRECTLY ACROSS TUESDAY NIGHT THROUGH WEDNESDAY AND THEN
HEADS INTO THE CANADIAN MARITIMES TOWARDS THE END OF THE WEEK. THE
NW FLOW DECREASES MONDAY NIGHT AND TUESDAY...STAYS LIGHT AND
VARIABLE MIDWEEK AND THEN BECOMES MORE SOUTHERLY THURSDAY AND
FRIDAY...WHICH WILL HELP WITH WARM AIR ADVECTION. THIS CONTINUES
FRIDAY NIGHT BUT TEMPERATURES TREND COOLER BEHIND A COLD FRONT
NEXT SATURDAY.
THE NEXT CHANCE OF RAIN DOES NOT ARRIVE UNTIL FRIDAY NIGHT INTO NEXT
SATURDAY WITH THE APPROACH OF THE NEXT COLD FRONT AND UPPER LEVEL
TROUGH.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
FORECAST DILEMMA OVERNIGHT CONTINUES TO BE WHETHER OR NOT CIGS DROP
INTO THE MVFR CATEGORY AS GUIDANCE CONTINUES TO DIFFER...AND
WHETHER CIGS THEN REMAIN MVFR. AREAS OF CIGS AROUND 2500FT IN THE
AREA AND WILL MENTION IN A TEMPO GROUP FOR NOW...KEEPING THE MAIN
FORECAST VFR...WITH CIGS AROUND 3500FT.
SE WINDS LESS THAN 10 KT WILL GRADUALLY VEER THROUGH THE NIGHT
AND BECOME WNW BEHIND THE COLD FRONT...10Z- 13Z. G20 KT POSSIBLE
IN THE MORNING.
A WAVE OF LOW PRESSURE THEN DEVELOPS ALONG THE COLD FRONT AS IT
STALLS JUST EAST OF THE TERMINALS SUN AFT. IT APPEARS THE NYC
TERMINALS WILL BE RIGHT ON THE WESTERN PERIPHERY OF THE RAIN WITH
CONDITIONS REMAINING VFR IN A NLY FLOW. HOWEVER...KGON AND POSSIBLY
KISP MAY EXPERIENCE SUB-VFR CONDITIONS IN RAIN.
.OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...
.LATE SUNDAY NIGHT...VFR.
.MONDAY...VFR. NW GUSTS 20-25 KT.
.TUESDAY-THURSDAY...VFR.
&&
.MARINE...
SE WINDS INCREASE AHEAD OF A WARM FRONT LATE TONIGHT. THEN WINDS
SHIFT S-SW BEHIND THE WARM FRONT...AND W-NW BEHIND THE COLD FRONT
SUNDAY MORNING. WINDS INCREASE IN THE MORNING...THEN MAY DIMINISH
BRIEFLY AS THE FRONT MOVES ACROSS BEFORE PICKING UP AGAIN FROM THE
NW LATE SUNDAY AND SUNDAY NIGHT.
SCA FOR THE OCEAN WATERS REMAINS IN EFFECT SUNDAY MORNING FOR
BORDERLINE WINDS AND SEAS. SOLID SCA CONDITIONS ARE ANTICIPATED
BEHIND THE COLD FRONT SUNDAY NIGHT.
FOR THE LONG TERM...MONDAY WILL STILL HAVE A STEEP PRESSURE GRADIENT
WITH NW FLOW 10-20 KT GUSTING UP TO AROUND 25 KT IN THE MORNING BUT
DECREASING IN THE AFTERNOON FOR THE OCEAN WATERS. SEAS ARE FORECAST
TO BE UP TO 5-6 FT ON THE OCEAN WATERS. THE OCEAN SEAS SLIGHTLY
LOWER MONDAY NIGHT AND TUESDAY BUT ARE STILL FORECAST TO BE NEAR 5
FT SO THERE WILL BE A CHANCE FOR SCA CONDITIONS ON THE OCEAN EARLY
NEXT WEEK. THERE IS SOME UNCERTAINTY AND WITH THE OFFSHORE
FLOW...SEAS COULD BE A LITTLE LOWER THAN FORECAST ESPECIALLY MONDAY
NIGHT AND TUESDAY AS HIGH PRESSURE MOVES IN CLOSER FROM THE SOUTH.
OTHER WATERS WILL STAY BELOW SCA THE WHOLE TIME.
FOR TUESDAY NIGHT THROUGH THURSDAY...SUB SCA CONDITIONS ARE FORECAST
WITH A WEAK PRESSURE GRADIENT IN PLACE AS HIGH PRESSURE ACROSS
THE WATERS CONTINUES.
&&
.HYDROLOGY...
NO SIGNIFICANT PRECIPITATION IS EXPECTED INTO THE START OF NEXT
WEEK.
DRY CONDITIONS ARE FORECAST MONDAY THROUGH FRIDAY WITH THE NEXT
CHANCE OF RAINFALL COMING FRIDAY NIGHT INTO NEXT SATURDAY.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 6 AM THIS MORNING TO 6 AM EST MONDAY
FOR ANZ350-353-355.
&&
$$
SYNOPSIS...JM/PW
NEAR TERM...JM/JP/DW/PW
SHORT TERM...PW
LONG TERM...JM
AVIATION...MET/DW
MARINE...JM/JP/PW
HYDROLOGY...JM/PW
AREA FORECAST DISCUSSION
NWS ALBANY NY
1243 AM EST SUN NOV 22 2015
.SYNOPSIS...
LOW PRESSURE WILL RACE FROM THE OTTAWA VALLEY INTO QUEBEC TODAY...AS
ITS COLD FRONT EXITS THE REGION THIS MORNING. HIGH PRESSURE WILL
CREST FROM THE OHIO VALLEY INTO THE NORTHEAST TONIGHT INTO MONDAY.
TUESDAY A WARM FRONT MOVE ACROSS THE REGION. WEDNESDAY INTO FRIDAY
HIGH PRESSURE WILL BUILD ALONG THE EASTERN SEABOARD...WITH MILD
FAIR CONDITIONS FOR NOVEMBER.
&&
.NEAR TERM /THROUGH SUNDAY NIGHT/...
AS OF 1158 PM EST...SHARP UPPER LEVEL TROUGH IS MOVING ACROSS THE
WESTERN GREAT LAKES...WITH SFC LOW PRESSURE LOCATED CLOSE TO
TORONTO...AND HEADED NORTHEAST. THE SFC COLD FRONT ATTACHED TO
THIS LOW PRESSURE AREA IS NOW CROSSING FAR WESTERN NEW YORK STATE
AND WESTERN PA...AND IS HEADED TOWARDS OUR AREA.
REGIONAL MOSAIC RADAR SHOWS SOME RETURNS OVER THE WESTERN
ADIRONDACKS...WITH ADDITIONAL ACTIVITY WELL UPSTREAM ALONG THE SFC
COLD FRONT ACROSS WESTERN NEW YORK. TEMPS HAVE BEEN VARIABLE
ACROSS THE REGION...WITH READING RANGING FROM THE LOW 30S OVER THE
ADIRONDACKS TO THE MID 40S IN THE HUDSON VALLEY. THIS IS DUE TO A
SOUTHERLY WIND BRINGING IN WARMER AIR UP THE HUDSON VALLEY AND
ALLOWING SOME MIXING...WHILE AREAS THAT HAVE BEEN CALM HAVE
ALLOWED TEMPS TO RADIATE. AS THE FRONTAL BOUNDARY
APPROACHES...TEMPS WILL LIKELY HOLD STEADY FOR MOST AREAS...ALTHOUGH
IN PLACES WHERE THE TEMPS HAS FALLEN INTO THE LOW 30S MAY ACTUALLY
RISE A LITTLE BIT. AS A RESULT...ANY LIGHT PRECIP WILL GENERALLY
BE IN THE FORM OF RAIN DUE TO ENOUGH WARMING IN THE BOUNDARY
LAYER...ALTHOUGH SOME HIGHER TERRAIN AND SHELTERED LOCATIONS IN
THE ADIRONDACKS COULD SEE SOME SNOW SHOWER ACTIVITY. UP TO A HALF
AN INCH OF ACCUMULATION WILL BE POSSIBLE BY DAYBREAK IN THOSE
AREAS.
OVERNIGHT LOWS HAVE ALREADY OCCURRED IN SOME AREAS...ALTHOUGH
TEMPS MAY FALL FOR THE HUDSON VALLEY TOWARDS SUNRISE AS THE FRONT
COMES THROUGH. MIN TEMPS LOOK TO BE IN THE 30S FOR MOST SPOTS.
AS THE FRONT MOVES ON BY...CHILLIER AIR WILL FILTER INTO THE REGION.
HOWEVER...WITH A WSW FLOW AND A GOOD DEAL OF SUNSHINE...TEMPERATURES
WILL ACTUALLY WARM TO NEAR 50 IN THE VALLEYS...WHILE HOLDING CLOSER
TO 40 ACROSS THE HIGHER TERRAIN. KEEP IN MIND THESE VALUES MIGHT
HAPPEN BY MIDDAY...WITH TEMPERATURES FALLING A BIT DURING THE
AFTERNOON.
IT WILL BE BREEZY WITH A WEST WIND 10-15 MPH...GUSTING TO 25 MPH
ESPECIALLY OVER THE HIGHER TERRAIN/MOHAWK VALLEY AND THE CAPITAL REGION.
WHILE MOST OF THE AREA WILL BE DRY WITH PARTIAL SUNSHINE...LAKE ENHANCED
CLOUDS AND PERHAPS SOME SNOW SHOWERS WILL PERSIST OVER
THE ADIRONDACKS. EVEN IF SURFACE TEMPERATURES ARE ABOVE FREEZING
ON SUNDAY...THE AIR WILL BE QUITE CHILLY ALOFT AND CERTAINLY VERTICAL
INSTABILITY AND UPSLOPE COULD GENERATE THESE SNOW SHOWERS EVEN IN
THE ABSENCE OF ANY PURE LAKE EFFECT.
HOWEVER...AFTER EXAMINING THE EXPERIMENTAL KVIE CSTAR PROGRAM...
IT NOW APPEARS THE INLAND LAKE EXTENT OFF OF ONTARIO WILL ONLY
BE ABOUT 50 MILES...LIMITED DUE TO SOME SHEAR IN THE COLUMN AND
DRY AIR IN THE MID LEVELS. THEREFORE PURE LAKE EFFECT SNOW
PLUMES MIGHT ONLY GRAZE HERKIMER AND LIKELY NOT EVEN REACH
HAMILTON COUNTIES. THEREFORE NO HEADLINES WERE ISSUED.
IF CONDITIONS LOOK DIFFERENT LATER ON...HEADLINES WILL BE RECONSIDERED.
ANY ADDITIONAL SNOW ACCUMULATIONS ON SUNDAY OVER THE ADIRONDACKS SHOULD
LIGHT...AN INCH OR LESS.
SUNDAY NIGHT THROUGH MONDAY...LARGE HIGH PRESSURE WILL BUILD TO
OUR SOUTH. ADDITIONAL SHORT WAVE ENERGY ALONG WITH ANOTHER MID
LEVEL TROUGH ROLLING TO OUR NORTH... COULD TRIGGER A FEW MORE
BOUTS OF SNOW SHOWERS WITH ADDITIONAL MAINLY MINOR ACCUMULATIONS
OVER OUR ADIRONDACKS AND PERHAPS CENTRAL MOHAWK VALLEY. THIS AGAIN
ASSUMES THE MAIN PLUMES OFF ONTARIO STAY MAINLY TO OUR WEST. IT
WILL BE A CLOSE CALL BUT RIGHT NOW THEY APPEAR TO JUST MISS MOST
OF OUR AREA.
THE POTENTIAL IS THERE FOR 1-4 INCHES OF SNOWFALL WHEN IT IS ALL SAID AND
DONE...SPREAD OUT OVER SEVERAL PERIODS SO AGAIN NO LAKE EFFECT SNOW
ADVISORIES WERE ISSUED WITH THIS PACKAGE. KEEP IN MIND IF ANY
PLUME FROM LAKE ONTARIO WAS ABLE TO PENETRATE INTO HERKIMER OR
HAMILTON COUNTIES...AMOUNTS COULD BE LOCALLY A LITTLE HIGHER.
THE REMAINDER OF THE REGION SHOULD REMAIN MOSTLY DRY ALTHOUGH A SPRINKLE
OR FLURRY IS POSSIBLE ALONG WITH OCCASIONAL CLOUDINESS. OTHERWISE
IT LOOKS CHILLY BUT NOTHING OUT OF THE ORDINARY FOR LATE NOVEMBER.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
MODEL SUITE IS IN AGREEMENT...AND SOLUTION HAS BEEN STABLE FOR A
FEW DAYS FOR THIS PERIOD. THIS WILL BE A PERIOD OF TRANSITION.
THERE MAY BE SOME LINGERING CLOUDS AND SNOW SHOWERS EARLY MONDAY
OVER W ADRNDKS...BUT CAP WILL BE LOW...UPPER SUPPORT GONE...AND
SHEAR UNFAVORABLE. OTHERWISE SFC PRESSURE RIDGE OVER REGION WILL
RESULT IN A FAIR DAY IN MOST AREAS.
MONDAY NIGHT INTO TUESDAY MID LEVEL WAA...FOLLOWED BY A WMFNT WILL
RESULT IN INCRG CLOUDS AND ISOLD TO SCT PCPN. HWVR BY TUES NT 500
HPA RIDGE WILL BE BUILDING ALONG THE E SEABOARD WITH FAIR
CONDS...AND SETTING THE STAGE FOR A TRANQUIL MILD THANKSGIVING
PERIOD.
TEMPS WILL BE NEAR TO SLIGHLY BLO NORMAL DURING THIS PERIOD. OTRW
AN IDEAL REGIME TO USE SUPERBLEND IN GRIDS. NO TARGETS OF
OPPORTUNITY IN THE STF.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY MAINLY DRY WEATHER
WITH THE NEXT CHANCE FOR PRECIPITATION ACROSS THE REGION FRIDAY INTO
SATURDAY AS A FRONTAL BOUNDARY MOVES ACROSS THE REGION.
AT THE START OF THE LONG TERM PERIOD...THE LONG RANGE GUIDANCE
CONTINUES TO BE IN VERY GOOD AGREEMENT WITH THE EVOLUTION OF THE
LONG TERM PATTERN. MUCH OF THE LONG TERM PERIOD WILL BE DOMINATED BY
HIGH PRESSURE AT THE SURFACE AND UPPER-LEVEL RIDGING ALOFT. THIS
WILL RESULT IN AN EXTENDED PERIOD OF DRY WEATHER TUESDAY NIGHT
THROUGH THURSDAY NIGHT...INCLUDING THANKSGIVING...WITH PARTLY CLOUDY
SKIES.
A FRONTAL BOUNDARY WILL MOVE ACROSS THE REGION FRIDAY INTO THE
SATURDAY TIME PERIOD. THERE IS SOME DIFFERENCE IN THE LONG RANGE
GUIDANCE REGARDING THE TIMING OF THIS FRONTAL BOUNDARY...BUT HAVE
INDICATED CHANCE POPS DURING THIS TIMEFRAME FOR RAIN SHOWERS DURING
THE DAYTIME HOURS...AND A MIX OF RAIN/SNOW SHOWERS DURING THE
NIGHTTIME HOURS WITH THE BEST CHANCE FOR SNOW ACROSS THE HIGHER
TERRAIN.
TEMPERATURES DURING THE LONG TERM PERIOD WILL BE SLIGHTLY ABOVE
NORMAL FOR LATE NOVEMBER. HIGHS ON WEDNESDAY WILL RANGE FROM THE
UPPER 30S/LOW 40S ACROSS THE HIGHER TERRAIN TO THE MID AND UPPER 40S
IN VALLEY AREAS. HIGHS ON THURSDAY AND FRIDAY WILL RANGE FROM THE
UPPER 40S TO MID 50S. HIGHS ON SATURDAY WILL RANGE FROM NEAR 40 TO
NEAR 50. LOWS TUESDAY NIGHT WILL RANGE FROM THE MID TO UPPER
20S...UPPER 20S TO LOWER 30S WEDNESDAY NIGHT...AND MID 30S TO NEAR
40 THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A FRONTAL BOUNDARY IS APPROACHING THE FROM THE GREAT LAKES
REGION. MAINLY VFR CONDITIONS ARE EXPECTED OVERNIGHT...ALTHOUGH
SOME PERIODS OF MVFR CIGS ARE POSSIBLE...ESP FOR KPSF. WILL
INCLUDE A VCSH FOR ALL SITES...BUT SHOWERS WILL BE VERY LIGHT AND
SPOTTY OVERNIGHT. MOST TAF SITES SHOULD ONLY SEE PRECIP AS
RAIN...ALTHOUGH CANNOT TOTALLY RULE OUT A FEW WET SNOWFLAKES
MIXING IN AT KGFL. SOUTH-SOUTHEAST WINDS WILL BE ABOUT 5-10 KTS
OVERNIGHT...ESP FOR KALB...WHERE WINDS WILL FUNNEL UP THE HUDSON
VALLEY.
ANY RAIN SHOWERS SHOULD BE DONE BY 12Z WITH THE PASSAGE OF THE
COLD FRONT...AND WINDS WILL SWITCH TO THE WEST AND BECOME GUSTY
FOR ALL SITES. VFR CONDITIONS ARE EXPECTED FOR THE WHOLE DAY ON
SUNDAY...WITH JUST SOME PATCHES OF STRATOCU CLOUDS AND HIGH CLOUDS
THROUGH THE DAY.
OUTLOOK...
SUNDAY NIGHT-THANKSGIVING DAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
A FRONTAL SYSTEM WILL BRING SOME SHOWERS OF RAIN AND SNOW TONIGHT...
HEAVIEST ACROSS THE ADIRONDACKS WHERE A COUPLE INCHES OF SNOW
COULD ACCUMULATE. OTHERWISE...RAIN SHOWER AMOUNTS WILL BE
VERY LIGHT...WELL UNDER A QUARTER INCH MOST PLACES.
ASIDE FROM ON GOING SNOW SHOWERS ACROSS THE ADIRONDACKS...
THE REMAINDER OF THE REGION LOOKS MAINLY DRY SUNDAY THROUGH
THANKSGIVING DAY. EACH NIGHT WILL SEE A NEAR RECOVERY
OF RR VALUES...DROPPING TO SEASONABLE LEVELS IN THE 40S AND
50S EACH AFTERNOON. AMOUNTS WILL BE HIGHER ACROSS THE ADIRONDACKS
WHERE THERE WILL BE POSSIBLE PRECIPITATION...GENERALLY
IN THE 50S AND EVEN 60S.
IT WILL BE SOMEWHAT BREEZY ON SUNDAY...WITH A WESTERLY
WIND 10-15 MPH WITH GUSTS TO 25 MPH ACROSS THE HIGHER
TERRAIN/MOHAWK VALLEY AND CAPITAL REGION.
THE WIND WILL GENERALLY BE LIGHTER THROUGH THE REMAINDER OF THE WEEK.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION AFTER TONIGHT DOES NOT
APPEAR TO BE UNTIL LATE FRIDAY OR SATURDAY.
&&
.HYDROLOGY...
NO HYDROLOGY ISSUES ARE EXPECTED THROUGH THE NEXT WEEK. OTHER THAN
THE POTENTIAL FOR SCATTERED SHOWERS TONIGHT AND LAKE
ENHANCED SNOW SHOWERS IN HAMILTON AND HERKIMER COUNTIES SUNDAY...THE
PERIOD WILL BE MAINLY DRY THROUGH FRIDAY.
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...SNYDER
NEAR TERM...FRUGIS/HWJIV/IRL
SHORT TERM...SNYDER
LONG TERM...IRL
AVIATION...FRUGIS
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
1158 PM EST SAT NOV 21 2015
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST THROUGH THE EASTERN
GREAT LAKES TONIGHT...AND DRAG A COLD FRONT ACROSS THE REGION WITH
WIDELY SCATTERED RAIN AND SNOW SHOWERS. ANY SNOWFALL ACCUMULATION
WILL BE CONFINED TO THE SOUTHERN ADIRONDACKS. BREEZY WEST TO
NORTHWEST WINDS WILL BRING COOLER AIR BACK INTO THE AREA ON
SUNDAY...ALONG WITH SOME LAKE EFFECT SNOW SHOWERS OVER THE
ADIRONDACKS. MAINLY DRY AND COLD WEATHER IS EXPECTED ON MONDAY
ALTHOUGH THERE COULD BE ADDITIONAL SNOW SHOWERS ACROSS THE
ADIRONDACKS.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 1158 PM EST...SHARP UPPER LEVEL TROUGH IS MOVING ACROSS THE
WESTERN GREAT LAKES...WITH SFC LOW PRESSURE LOCATED CLOSE TO
TORONTO...AND HEADED NORTHEAST. THE SFC COLD FRONT ATTACHED TO
THIS LOW PRESSURE AREA IS NOW CROSSING FAR WESTERN NEW YORK STATE
AND WESTERN PA...AND IS HEADED TOWARDS OUR AREA.
REGIONAL MOSAIC RADAR SHOWS SOME RETURNS OVER THE WESTERN
ADIRONDACKS...WITH ADDITIONAL ACTIVITY WELL UPSTREAM ALONG THE SFC
COLD FRONT ACROSS WESTERN NEW YORK. TEMPS HAVE BEEN VARIABLE
ACROSS THE REGION...WITH READING RANGING FROM THE LOW 30S OVER THE
ADIRONDACKS TO THE MID 40S IN THE HUDSON VALLEY. THIS IS DUE TO A
SOUTHERLY WIND BRINGING IN WARMER AIR UP THE HUDSON VALLEY AND
ALLOWING SOME MIXING...WHILE AREAS THAT HAVE BEEN CALM HAVE
ALLOWED TEMPS TO RADIATE. AS THE FRONTAL BOUNDARY
APPROACHES...TEMPS WILL LIKELY HOLD STEADY FOR MOST AREAS...ALTHOUGH
IN PLACES WHERE THE TEMPS HAS FALLEN INTO THE LOW 30S MAY ACTUALLY
RISE A LITTLE BIT. AS A RESULT...ANY LIGHT PRECIP WILL GENERALLY
BE IN THE FORM OF RAIN DUE TO ENOUGH WARMING IN THE BOUNDARY
LAYER...ALTHOUGH SOME HIGHER TERRAIN AND SHELTERED LOCATIONS IN
THE ADIRONDACKS COULD SEE SOME SNOW SHOWER ACTIVITY. UP TO A HALF
AN INCH OF ACCUMULATION WILL BE POSSIBLE BY DAYBREAK IN THOSE
AREAS.
OVERNIGHT LOWS HAVE ALREADY OCCURRED IN SOME AREAS...ALTHOUGH
TEMPS MAY FALL FOR THE HUDSON VALLEY TOWARDS SUNRISE AS THE FRONT
COMES THROUGH. MIN TEMPS LOOK TO BE IN THE 30S FOR MOST SPOTS.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
AS THE FRONT MOVES ON BY...CHILLIER AIR WILL FILTER INTO THE REGION.
HOWEVER...WITH A WSW FLOW AND A GOOD DEAL OF SUNSHINE...TEMPERATURES
WILL ACTUALLY WARM TO NEAR 50 IN THE VALLEYS...WHILE HOLDING CLOSER
TO 40 ACROSS THE HIGHER TERRAIN. KEEP IN MIND THESE VALUES MIGHT
HAPPEN BY MIDDAY...WITH TEMPERATURES FALLING A BIT DURING THE
AFTERNOON.
IT WILL BE BREEZY WITH A WEST WIND 10-15 MPH...GUSTING TO 25 MPH
ESPECIALLY OVER THE HIGHER TERRAIN/MOHAWK VALLEY AND THE CAPITAL REGION.
WHILE MOST OF THE AREA WILL BE DRY WITH PARTIAL SUNSHINE...LAKE ENHANCED
CLOUDS AND PERHAPS SOME SNOW SHOWERS WILL PERSIST OVER
THE ADIRONDACKS. EVEN IF SURFACE TEMPERATURES ARE ABOVE FREEZING
ON SUNDAY...THE AIR WILL BE QUITE CHILLY ALOFT AND CERTAINLY VERTICAL
INSTABILITY AND UPSLOPE COULD GENERATE THESE SNOW SHOWERS EVEN IN
THE ABSENCE OF ANY PURE LAKE EFFECT.
HOWEVER...AFTER EXAMINING THE EXPERIMENTAL KVIE CSTAR PROGRAM...
IT NOW APPEARS THE INLAND LAKE EXTENT OFF OF ONTARIO WILL ONLY
BE ABOUT 50 MILES...LIMITED DUE TO SOME SHEAR IN THE COLUMN AND
DRY AIR IN THE MID LEVELS. THEREFORE PURE LAKE EFFECT SNOW
PLUMES MIGHT ONLY GRAZE HERKIMER AND LIKELY NOT EVEN REACH
HAMILTON COUNTIES. THEREFORE NO HEADLINES WERE ISSUED.
IF CONDITIONS LOOK DIFFERENT LATER ON...HEADLINES WILL BE RECONSIDERED.
ANY ADDITIONAL SNOW ACCUMULATIONS ON SUNDAY OVER THE ADIRONDACKS SHOULD
LIGHT...AN INCH OR LESS.
SUNDAY NIGHT THROUGH MONDAY NIGHT...LARGE HIGH PRESSURE WILL
BUILD TO OUR SOUTH. ADDITIONAL SHORT WAVE ENERGY ALONG
WITH ANOTHER MID LEVEL TROUGH ROLLING TO OUR NORTH...
COULD TRIGGER A FEW MORE BOUTS OF SNOW SHOWERS WITH ADDITIONAL
MAINLY MINOR ACCUMULATIONS OVER OUR ADIRONDACKS AND
PERHAPS CENTRAL MOHAWK VALLEY. THIS AGAIN ASSUMES THE MAIN
PLUMES OFF ONTARIO STAY MAINLY TO OUR WEST. IT WILL BE A CLOSE
CALL BUT RIGHT NOW THEY APPEAR TO JUST MISS MOST OF OUR AREA.
THE POTENTIAL IS THERE FOR 1-4 INCHES OF SNOWFALL WHEN IT IS ALL SAID AND
DONE...SPREAD OUT OVER SEVERAL PERIODS SO AGAIN NO LAKE EFFECT SNOW
ADVISORIES WERE ISSUED WITH THIS PACKAGE. KEEP IN MIND IF ANY
PLUME FROM LAKE ONTARIO WAS ABLE TO PENETRATE INTO HERKIMER OR
HAMILTON COUNTIES...AMOUNTS COULD BE LOCALLY A LITTLE HIGHER.
THE REMAINDER OF THE REGION SHOULD REMAIN MOSTLY DRY ALTHOUGH A SPRINKLE
OR FLURRY IS POSSIBLE ALONG WITH OCCASIONAL CLOUDINESS.
OTHERWISE IT LOOKS CHILLY BUT NOTHING OUT OF THE ORDINARY
FOR LATE NOVEMBER.
LOW TEMPERATURES MONDAY MORNING WILL BE MAINLY IN THE 20S...WITH SOME TEENS
IN THE COLDEST AREAS. HIGHS MONDAY WILL BE ONLY IN THE UPPER 20S TO MID 30S
HIGHER TERRAIN...CLOSE TO 40 IN THE VALLEYS.
BY TUESDAY...AS HIGH PRESSURE SLOWLY BEGINS TO BUILD ALOFT...THERE WILL BE
SLOW MODERATION IN THE AIRMASS. ANY LINGERING SNOW SHOWERS WILL
CEASE ACROSS THE ADIRONDACKS. OTHERWISE IT WILL BE MOSTLY SUNNY.
LOWS TUESDAY MORNING WILL RANGE FROM THE MID TEENS TO MID 20S.
HIGHS TUESDAY WILL RANGE FROM THE 30S OVER THE HIGHER TERRAIN...
LOWER TO MID 40S IN THE VALLEYS.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE LONG TERM PERIOD WILL BE CHARACTERIZED BY MAINLY DRY WEATHER
WITH THE NEXT CHANCE FOR PRECIPITATION ACROSS THE REGION FRIDAY INTO
SATURDAY AS A FRONTAL BOUNDARY MOVES ACROSS THE REGION.
AT THE START OF THE LONG TERM PERIOD...THE LONG RANGE GUIDANCE
CONTINUES TO BE IN VERY GOOD AGREEMENT WITH THE EVOLUTION OF THE
LONG TERM PATTERN. MUCH OF THE LONG TERM PERIOD WILL BE DOMINATED BY
HIGH PRESSURE AT THE SURFACE AND UPPER-LEVEL RIDGING ALOFT. THIS
WILL RESULT IN AN EXTENDED PERIOD OF DRY WEATHER TUESDAY NIGHT
THROUGH THURSDAY NIGHT...INCLUDING THANKSGIVING...WITH PARTLY CLOUDY
SKIES.
A FRONTAL BOUNDARY WILL MOVE ACROSS THE REGION FRIDAY INTO THE
SATURDAY TIME PERIOD. THERE IS SOME DIFFERENCE IN THE LONG RANGE
GUIDANCE REGARDING THE TIMING OF THIS FRONTAL BOUNDARY...BUT HAVE
INDICATED CHANCE POPS DURING THIS TIMEFRAME FOR RAIN SHOWERS DURING
THE DAYTIME HOURS...AND A MIX OF RAIN/SNOW SHOWERS DURING THE
NIGHTTIME HOURS WITH THE BEST CHANCE FOR SNOW ACROSS THE HIGHER
TERRAIN.
TEMPERATURES DURING THE LONG TERM PERIOD WILL BE SLIGHTLY ABOVE
NORMAL FOR LATE NOVEMBER. HIGHS ON WEDNESDAY WILL RANGE FROM THE
UPPER 30S/LOW 40S ACROSS THE HIGHER TERRAIN TO THE MID AND UPPER 40S
IN VALLEY AREAS. HIGHS ON THURSDAY AND FRIDAY WILL RANGE FROM THE
UPPER 40S TO MID 50S. HIGHS ON SATURDAY WILL RANGE FROM NEAR 40 TO
NEAR 50. LOWS TUESDAY NIGHT WILL RANGE FROM THE MID TO UPPER
20S...UPPER 20S TO LOWER 30S WEDNESDAY NIGHT...AND MID 30S TO NEAR
40 THURSDAY AND FRIDAY NIGHTS.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
A FRONTAL BOUNDARY IS APPROACHING THE FROM THE GREAT LAKES
REGION. MAINLY VFR CONDITIONS ARE EXPECTED OVERNIGHT...ALTHOUGH
SOME PERIODS OF MVFR CIGS ARE POSSIBLE...ESP FOR KPSF. WILL
INCLUDE A VCSH FOR ALL SITES...BUT SHOWERS WILL BE VERY LIGHT AND
SPOTTY OVERNIGHT. MOST TAF SITES SHOULD ONLY SEE PRECIP AS
RAIN...ALTHOUGH CANNOT TOTALLY RULE OUT A FEW WET SNOWFLAKES
MIXING IN AT KGFL. SOUTH-SOUTHEAST WINDS WILL BE ABOUT 5-10 KTS
OVERNIGHT...ESP FOR KALB...WHERE WINDS WILL FUNNEL UP THE HUDSON
VALLEY.
ANY RAIN SHOWERS SHOULD BE DONE BY 12Z WITH THE PASSAGE OF THE
COLD FRONT...AND WINDS WILL SWITCH TO THE WEST AND BECOME GUSTY
FOR ALL SITES. VFR CONDITIONS ARE EXPECTED FOR THE WHOLE DAY ON
SUNDAY...WITH JUST SOME PATCHES OF STRATOCU CLOUDS AND HIGH CLOUDS
THROUGH THE DAY.
OUTLOOK...
SUNDAY NIGHT-THANKSGIVING DAY: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.FIRE WEATHER...
A FRONTAL SYSTEM WILL BRING SOME SHOWERS OF RAIN AND SNOW TONIGHT...
HEAVIEST ACROSS THE ADIRONDACKS WHERE A COUPLE INCHES OF SNOW
COULD ACCUMULATE. OTHERWISE...RAIN SHOWER AMOUNTS WILL BE
VERY LIGHT...WELL UNDER A QUARTER INCH MOST PLACES.
ASIDE FROM ON GOING SNOW SHOWERS ACROSS THE ADIRONDACKS...
THE REMAINDER OF THE REGION LOOKS MAINLY DRY SUNDAY THROUGH
THANKSGIVING DAY. EACH NIGHT WILL SEE A NEAR RECOVERY
OF RR VALUES...DROPPING TO SEASONABLE LEVELS IN THE 40S AND
50S EACH AFTERNOON. AMOUNTS WILL BE HIGHER ACROSS THE ADIRONDACKS
WHERE THERE WILL BE POSSIBLE PRECIPITATION...GENERALLY
IN THE 50S AND EVEN 60S.
IT WILL BE SOMEWHAT BREEZY ON SUNDAY...WITH A WESTERLY
WIND 10-15 MPH WITH GUSTS TO 25 MPH ACROSS THE HIGHER
TERRAIN/MOHAWK VALLEY AND CAPITAL REGION.
THE WIND WILL GENERALLY BE LIGHTER THROUGH THE REMAINDER OF THE WEEK.
THE NEXT CHANCE OF WIDESPREAD PRECIPITATION AFTER TONIGHT DOES NOT
APPEAR TO BE UNTIL LATE FRIDAY OR SATURDAY.
&&
.HYDROLOGY...
NO HYDROLOGY ISSUES ARE EXPECTED THROUGH THE NEXT WEEK. OTHER THAN
THE POTENTIAL FOR SCATTERED SHOWERS TONIGHT AND LAKE
ENHANCED SNOW SHOWERS IN HAMILTON AND HERKIMER COUNTIES SUNDAY...THE
PERIOD WILL BE MAINLY DRY THROUGH FRIDAY.
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...HWJIV/IRL
NEAR TERM...FRUGIS/HWJIV/IRL
SHORT TERM...HWJIV
LONG TERM...IRL
AVIATION...FRUGIS
FIRE WEATHER...HWJIV
HYDROLOGY...HWJIV
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
336 AM EST SUN NOV 22 2015
.SHORT TERM (TODAY AND MONDAY)...
MORNING WATER VAPOR IMAGERY AND RUC ANALYSIS DEPICT INCREASING
TROUGHINESS ACROSS THE CENTRAL AND SOUTHEASTERN U.S. THIS
OCCURRING IN RESPONSE TO A FAST MOVING SHORTWAVE EMANATING FROM
THE CENTRAL AND SOUTHERN PLAINS. ON THE HEELS OF THIS FEATURE...A
STRONG COLD FRONT IS SURGING SOUTHWARD. AHEAD OF THE FRONT...ALONG
A REMNANT FRONTAL ZONE... A DISORGANIZED AREA OF LOW PRESSURE
CONTINUES TO MEANDER EASTWARD ACROSS THE EASTERN GULF. SCATTERED
TO NUMEROUS SHOWERS AND EMBEDDED THUNDERSTORMS ASSOCIATED WITH
THIS FEATURE ARE STEWING OVER THE WARM GULF WATERS...WITH LESSER
COVERAGE OVER THE MAINLAND.
AS THE AREA OF LOW PRESSURE CONTINUES TO DRIFT ACROSS THE
STATE...SCATTERED SHOWERS AND EMBEDDED THUNDERSTORMS WILL REMAIN
POSSIBLE THROUGH MUCH OF THE MORNING HOURS...AND INTO THE EARLY
AFTERNOON. RECENT RADAR TRENDS HAVE SHOWN A GENERAL DECREASE IN
REFLECTIVITIES INLAND...WITH A NOTED INCREASE IN CONVECTIVE
COVERAGE OVER THE WATERS...LIKELY IN RESPONSE TO APPROACHING
HEIGHT FALLS/LIFT ASSOCIATED WITH THE SHORTWAVE AND FRONT.
THROUGH THE DAY TODAY...SHOWERS AND ISOLATED STORMS WILL
GRADUALLY END FROM NORTH TO SOUTH...AS THE STRONG COLD FRONT
SURGES SOUTHWARD ACROSS THE AREA. WILL MAINTAIN LIKELY POPS NORTH
OF I-4 THROUGH EARLY AFTERNOON...BUT THIS SHOULD SHUT OFF QUICKLY
AS DRIER AND MUCH COOLER AIR IS ADVECTED IN BEHIND THE FRONT.
AREAS SOUTH OF I-4 WILL SEE SHOWERS/STORMS COME TO AN END SOMETIME
THIS EVENING...AS THE FRONT EVENTUALLY WORKS SOUTH.
WITH RATHER HIGH PRECIPITABLE WATER VALUES...LOCALLY HEAVY
RAINFALL WILL BE LIKELY...ESPECIALLY WITH ANY THUNDERSTORMS THAT
OCCUR. IN ADDITION...WEAK MID TROPOSPHERIC FLOW WILL LEAD TO SLOW
SHOWER/STORM MOVEMENT...AND SOME TRAINING OF CONVECTIVE ELEMENTS
IS ALSO POSSIBLE...LEADING TO LOCALLY ENHANCED POTENTIAL FOR
FLOODING. AT THIS TIME...IT APPEARS AREAS ALONG AND SOUTH OF I-4
WILL EXPERIENCE THE HEAVIER RAINS AND HIGHER RAINFALL TOTALS.
RADAR ESTIMATES SHOW UP TO 2 TO 3 INCHES OF RAIN HAVE ALREADY
FALLEN IN LOCALIZED AREAS...AND AN ADDITIONAL INCH TO TWO INCHES
WILL BE POSSIBLE IN SOME AREAS. PLEASE PAY ATTENTION AS YOU TRAVEL
TODAY...AND BE PREPARED FOR SLOW DOWNS WITHIN HEAVIER RAINS.
ON THE HEELS OF THE FRONT...BREEZY NORTHEAST WINDS WILL
OVERSPREAD THE AREA THIS AFTERNOON AND TONIGHT. AS COLD ADVECTION
PERSISTS OVERNIGHT...EXPECT LOWS TO TUMBLE...WITH WIDESPREAD 40
AND 50 DEGREE READINGS...AND PERHAPS EVEN SOME UPPER 30S UP NORTH
FOR MONDAY MORNING LOWS. WITH PERSISTENT NORTHEAST WINDS...HIGHS
WILL COME IN BELOW NORMAL MONDAY... GENERALLY IN THE 60S...THOUGH
PARTS OF LEVY AND CITRUS COUNTIES MAY ONLY RISE INTO THE UPPER
50S. TIME TO BREAK OUT SOME WARMER CLOTHES!
.LONG TERM (MONDAY NIGHT THROUGH SATURDAY)...
THE UPPER TROUGH OVER THE EASTERN U.S. THAT PUSHED A FRONTAL
BOUNDARY SOUTH OF FLORIDA WILL CONTINUE TO FILL AND PROVIDE A MORE
ZONAL MID LEVEL FLOW. HIGH PRESSURE WILL SETTLE INTO THE SE U.S.
NORTH OF FLORIDA BRINGING TEMPERATURES NEAR TO SLIGHTLY BELOW
NORMAL AND A STRONGER PRESSURE GRADIENT ACROSS THE STATE THAT WILL
INCREASE WINDS MAINLY OVER THE GULF WATERS. BY WEDNESDAY THE
CENTER OF HIGH PRESSURE WILL SHIFT NORTH OVER NEW ENGLAND BUT
LEAVE THE PRESSURE GRADIENT AND EASTERLY FLOW OVER THE PENINSULA
WHICH WILL MODERATE TEMPERATURES AND BRING MOIST AIR FROM THE
ATLANTIC. MODELS IN GOOD AGREEMENT THAT AN UPPER LOW DEVELOPS OFF
THE COAST OF FLORIDA THURSDAY BUT PROVIDES LITTLE INFLUENCE TO
WEAKENING HIGH PRESSURE OVER THE STATE INTO THE WEEKEND.
&&
.AVIATION...
VERY TRICKY AVIATION FORECAST WILL UNFOLD OVER THE NEXT 12 TO 18
HR. WITH A DISORGANIZED AREA OF LOW PRESSURE...AND AN APPROACHING
FRONT...SCATTERED TO WIDESPREAD SHOWERS AND ISOLATED STORMS WILL
REMAIN POSSIBLE THROUGH AT LEAST EARLY TO MID AFTERNOON. HEAVY
RAIN MAY ACCOMPANY SHOWERS AND STORMS...REDUCING VSBYS TO 3 MILES
OR LESS AT TIMES. IN ADDITION...ABUNDANT MOISTURE WILL CREATE
OCCASIONAL IFR CIGS...ESPECIALLY THROUGH THE LATE MORNING HOURS.
BY EARLY TO MID AFTERNOON...A STRONG COLD FRONT WILL WORTH
SOUTH...BRINGING AN END TO RAIN CHANCES FROM NORTH TO SOUTH BY
THIS EVENING...AND GENERATING BRISK NORTHEAST WINDS THROUGH THE
REMAINDER OF THE TAF PERIOD.
&&
.MARINE...
VARIABLE WINDS WILL EXIST ACROSS THE WATERS THROUGH SUNRISE IN
THE PRESENCE OF A WEAK AREA OF LOW PRESSURE. WINDS AND SEAS MAY BE
LOCALLY ENHANCED AROUND MARINE THUNDERSTORMS. A STRONG COLD FRONT
WILL SURGE SOUTHWARD ACROSS THE WATERS THROUGH THE DAY...WITH
STRONG NORTHEAST WINDS OF 15 TO 25 KNOTS OFFSHORE...EVENTUALLY
OVERSPREADING THE NEAR SHORE WATERS TONIGHT. THIS WILL CREATE
HAZARDOUS BOATING CONDITIONS AND A SMALL CRAFT ADVISORY WILL BE IN
EFFECT STARTING THIS MORNING...AND EXTENDING INTO THE DAY ON
TUESDAY. WINDS WILL WEAKEN SOMEWHAT LATE TUESDAY THROUGH THE
REMAINDER OF NEXT WEEK...WITH PERIODS OF CAUTIONARY TO BORDERLINED
ADVISORY LEVEL WINDS...AS HIGH PRESSURE SETTLES IN TO THE NORTH.
&&
.FIRE WEATHER...
HIGH HUMIDITY VALUES AND WIDESPREAD RAIN WILL KEEP FIRE CONCERNS
AT BAY THROUGH TONIGHT. A STRONG COLD FRONT WILL BRING MUCH DRIER
AIR INTO THE REGION MONDAY AND TUESDAY. HOWEVER...COOLER
TEMPERATURES SHOULD KEEP HUMIDITIES FROM FALLING TO CRITICAL
VALUES DURING THIS TIME. MOISTURE WILL GRADUALLY INCREASE FROM MID
TO LATE WEEK...WITH NO WILDFIRE CONCERNS EXPECTED.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 74 52 67 50 / 70 10 0 0
FMY 77 57 72 53 / 80 30 0 0
GIF 72 49 66 49 / 70 10 0 0
SRQ 76 55 68 52 / 70 10 0 0
BKV 71 47 64 43 / 70 10 0 0
SPG 73 57 67 54 / 70 10 0 0
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...BEACH HAZARDS STATEMENT THROUGH MONDAY EVENING FOR COASTAL
SARASOTA-PINELLAS.
GULF WATERS...SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 1 PM EST
TUESDAY FOR WATERS FROM ENGLEWOOD TO TARPON SPRINGS
FL OUT 20 TO 60 NM-WATERS FROM TARPON SPRINGS TO
SUWANNEE RIVER FL OUT 20 TO 60 NM.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST
TUESDAY FOR COASTAL WATERS FROM BONITA BEACH TO
ENGLEWOOD FL OUT 20 NM-COASTAL WATERS FROM ENGLEWOOD
TO TARPON SPRINGS FL OUT 20 NM-COASTAL WATERS FROM
TARPON SPRINGS TO SUWANNEE RIVER FL OUT 20 NM-WATERS
FROM BONITA BEACH TO ENGLEWOOD FL OUT 20 TO 60 NM.
&&
$$
SHORT TERM/AVIATION/MARINE/FIRE WEATHER...84/AUSTIN
LONG TERM...03/PAXTON
DECISION SUPPORT...03/PAXTON
AREA FORECAST DISCUSSION
NWS MIAMI FL
104 AM EST SUN NOV 22 2015
.AVIATION...
SHOWER COVERAGE HAS DIMINISHED LATE THIS EVENING...SO HAVE KEPT
ONLY VCSH IN TAFS THROUGH MID-MRNG...THEN WITH PREVAILING
RAIN/SHOWERS THROUGH SUNSET AS POPS NEAR 100 PERCENT. ACTIVITY
WILL ONLY GRADUALLY DIMINISH SUNDAY NIGHT...VCSH MAINTAINED. CANT
RULE OUT ISOLATED THUNDER...BUT NO MENTION IN TAFS ATTM. PERIODS
OF VSBY AND ESPECIALLY CIG RESTRICTIONS QUITE POSSIBLE...BUT
DURATIONS SHOULD BE BRIEF AND TIMING QUITE UNCERTAIN SO FOR NOW
WILL LEAVE VFR PREVAILING. DID ADD TEMPO MVFR CIGS AT KPBI
OVERNIGHT...WHERE LOW STRATUS APPEARS TO BE MOST PREVALENT. LIGHT
MAINLY NORTH WINDS OVERNIGHT WILL TURN SOUTHWEST BY MID-
MORNING...AND INCREASE IN SPEED AS THEY BACK TO THE WEST AND
EVENING NORTH AFTER SUNSET. GUSTS TO 20 KT AFTER NOON ARE
POSSIBLE.
&&
.PREV DISCUSSION... /ISSUED 715 PM EST SAT NOV 21 2015/
UPDATE...
A BRIEF RESPITE IN THE RAIN OCCURRING ACROSS PORTIONS OF SOUTH FL
THIS MID EVENING....WITH RAIN MOST WIDESPREAD ACROSS THE LAKE
OKEECHOBEE REGION. HOWEVER, RECENT SHOWER DEVELOPMENT JUST
OCCURRED OVER THE SOUTHERN EVERGLADES...AND THIS IS LIKELY A SIGN
OF CONTINUED DEVELOPMENT WITH WAVES OF SHOWERS AND A FEW
THUNDERSTORMS IMPACTING SOUTH FL THROUGHOUT THE NIGHT. HRRR AND
WRF RUNS SHOWING ACTIVE WEATHER OVERNIGHT. AS SUCH...WILL
MAINTAIN THE HIGH POPS GIVEN THE LIKELIHOOD OF RE- DEVELOPMENT.
/GREGORIA
PREV DISCUSSION... /ISSUED 333 PM EST SAT NOV 21 2015/
DISCUSSION...
A NEARLY STATIONARY FRONTAL BOUNDARY STRETCHES OVER CENTRAL
FLORIDA JUST NORTH OF LAKE OKEECHOBEE. WATER VAPOR IMAGERY SHOWS A
TROUGH DIGGING INTO THE GULF OF MEXICO WITH A NOTABLE SHORTWAVE
ACROSS THE NW GULF. THIS WILL MOVE ESE AND ACROSS FLORIDA ON
SUNDAY. IN ADVANCE OF THIS FEATURE...A SOUTHEAST WIND IS PUMPING
MOISTURE INTO THE AREA. MID LEVELS HAVE COOLED...AND WITH THE
MOIST, UNSTABLE ATMOSPHERE...WAVES OF SHOWERS AND A FEW
THUNDERSTORMS HAVE BEEN DEVELOPING ACROSS SOUTH FLORIDA THIS
AFTERNOON.
NOTING A COUPLE OF BANDS OF HEFTY SHOWERS/STORMS SETTING UP
RECENTLY...ONE OVER METRO BROWARD AND ANOTHER FORMING JUST OFF
MIAMI BEACH. WILL NEED TO WATCH THESE AS TRAINING CELLS WITHIN
THESE BANDS COULD RESULT IN LOCALIZED FLOODING.
FOR TONIGHT-SUNDAY...NUMEROUS TO WIDESPREAD SHOWERS AND A FEW
THUNDERSTORMS WILL BE THE RULE IN ADVANCE OF THE SHORTWAVE.
MOISTURE WILL REMAIN HIGH AND INSTABILITY JUST ENOUGH FOR
A FEW THUNDERSTORMS. HELICITY DOES LOOK TO INCREASE LATE TONIGHT-
EARLY SUNDAY MORNING...BUT ANY SEVERE RISK IS LOOKING EXTREMELY
LOW AT THIS POINT...GIVEN THE OVERCAST SKIES AND CONVECTIVE
OVERTURNING OF THE ATMOSPHERE. SO THE MAIN RISK TO HIGHLIGHT IS
THE POTENTIAL FOR LOCALLY HEAVY RAINFALL LEADING TO STREET
FLOODING.
THE FRONT GETS A PUSH SOUTHWARD SUNDAY EVENING...AND PASSES ACROSS
SOUTH FL DURING THE EVENING PER GFS AND SLIGHTLY LATER PER ECWMF.
RAIN/TSTORMS ACTIVITY WILL GET SHUNTED OFF THE SOUTHEAST COAST AS
IT PASSES WITH COOLER AND MUCH LESS HUMID AIR FLOWING INTO SOUTH
FLORIDA ON NORTHERLY WINDS BEHIND THE FRONT. THIS WILL DROP TEMPS
FINALLY BELOW 70F FOR THE FIRST TIME THIS FALL FOR FORT LAUDERDALE
AND MIAMI (RECORD LATEST DATE!)
LOWS BY MONDAY MORNING WILL FEEL CHILLY AFTER SUCH A WARM, HUMID
FALL...WITH LOWS FALLING INTO THE 60S SOUTHEAST LOCALES TO THE
50S FROM THE NAPLES AREA TO THE LAKE OKEECHOBEE REGION. HIGHS
TUESDAY WILL ONLY RANGE FROM AROUND 70F NEAR LAKE OKEECHOBEE TO
THE MID 70S SOUTHEAST COAST. TEMPS WILL GRADUALLY WARM DURING THE
MIDDLE PART OF NEXT WEEK. A BREEZY NE-E WIND FLOW WILL PERSIST
NEXT WEEK AND WITH DEWPOINTS IN THE 60S...IT WILL FEEL NICE. A
FEW SHOWERS LOOK TO DEVELOP AND MOVE ONSHORE THE EAST COAST NEXT
WEEK AS LOW LEVEL MOISTURE INCREASES...BUT THEY WILL BE QUICK
PASSING WITH MOST LOCALES REMAINING DRY MOST OF THE TIME.
THE PERSISTENT STRONG ONSHORE WINDS ALONG THE ATLANTIC COAST NEXT
WEEK WILL RESULT IN A HIGH RISK OF RIP CURRENTS AT THE ATLANTIC
BEACHES EXTENDING THROUGH MUCH OF NEXT WEEK. /GREGORIA
MARINE...
WINDS WILL BE ON THE INCREASE OUT OF THE SOUTH TO SOUTHEAST OVER
THE WATERS OVERNIGHT, BECOMING SOUTHWESTERLY ON SUNDAY THEN
NORTHERLY BEHIND A COLD FRONTAL PASSAGE SUNDAY NIGHT-MONDAY. SEAS
WILL RAPIDLY INCREASE SUNDAY NIGHT TO 7-9 FEET OVER THE OFFSHORE
GULF WATERS AND 9+ FEET IN THE GULF STREAM. WINDS WILL TURN
NORTHEASTERLY BY TUESDAY, THEN CONTINUE E-NE THROUGH LATE NEXT
WEEK WITH A FRESH BREEZE PREVAILING.
THE NEXT HIGH TIDE CYCLE IS COMING UP NEXT WEEK, WITH HIGHEST
ASTRONOMICAL TIDES ON WEDNESDAY AND THANKSGIVING DAY. NUISANCE
TIDAL FLOODING COULD BE AN ISSUE FOR MOST OF THE UPCOMING WEEK AND
POSSIBLY EXACERBATED BY THE PERSISTENT ONSHORE WINDS ALONG THE
ATLANTIC COAST. STILL TOO EARLY TO TELL WHETHER WE`LL SEE ANY
TIDAL FLOODING BUT THE POSSIBILITY CERTAINLY EXISTS AND WE`LL KEEP
A CLOSE EYE ON IT DURING THE NEXT SEVERAL DAYS.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 62 74 64 78 / 50 10 20 20
FORT LAUDERDALE 62 75 65 78 / 60 20 20 20
MIAMI 67 77 64 79 / 60 20 20 20
NAPLES 59 73 56 78 / 50 0 0 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...59/RM
LONG TERM....57/DG
AVIATION...23/SK
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
125 AM EST SUN NOV 22 2015
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE FORECAST AREA TONIGHT. COLDER
AND DRIER AIR WILL FILTER INTO THE REGION BEHIND THE FRONT...AS
HIGH PRESSURE SETTLES INTO THE REGION THROUGH TUESDAY. DRY
WEATHER EXPECTED TO CONTINUE MID TO LATE WEEK...AS HIGH PRESSURE
REMAINS OVER THE EASTERN SEABOARD...WITH MODERATING TEMPERATURES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SOUTHWESTERLY FLOW ALOFT WILL CONTINUE OVER THE FORECAST AREA
THROUGH THE OVERNIGHT PERIOD. WEAK ISENTROPIC LIFT IS SUPPORTING
SCATTERED LIGHT RAIN SHOWERS MAINLY IN THE EASTERN PART OF THE AREA
TONIGHT. SURFACE COLD FRONT THAT WILL MOVE THROUGH THE REGION LATE
TONIGHT IS NEAR THE APPALACHIANS AS OF 03Z. WINDS WILL INCREASE
TOWARD 12Z AS THE PRESSURE GRADIENT TIGHTENS BEHIND THE FRONT.
RAIN CHANCES WILL DIMINISH FROM SOUTHWEST TO NORTHEAST LATE TONIGHT
AS THE FRONT PUSHES THROUGH AND THE BEST DYNAMICS SHIFT FURTHER OFF
TO THE NORTH AND EAST. HAVE GENERALLY GONE WITH CHANCE POPS INTO
EARLY PORTIONS OF TONIGHT...WITH COVERAGE SCATTERED. RAINFALL
AMOUNTS WITH THIS SYSTEM ARE EXPECTED TO REMAIN ON THE LIGHT SIDE.
THE HRRR SHOWS ANOTHER BAND OF RAINFALL MOVING INTO MAINLY THE
EASTERN PORTION OF THE FORECAST AREA FROM SOUTH TO NORTH AROUND 10Z
WHICH APPEARS TO BE ASSOCIATED WITH SHORTWAVE ENERGY. HAVE CONTINUED
WITH A SLIGHT CHANCE MAINLY EAST THROUGH 12Z.
TEMPERATURES SLOWLY FALLING WITH THE RAINFALL TONIGHT SO HAVE
ADJUSTED CURRENT FORECAST. OVERNIGHT LOWS IN THE MID 40S TO NEAR 50.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
ANOTHER UPPER VORT/JET STREAK WILL SHIFT SE AND DEEPEN THE UPPER
TROUGH AND SHIFT IT INTO THE E CONUS SUN/SUN NT....WITH TROUGH
AXIS PASSING THROUGH OUR REGION SUN NT. THIS WILL LEAD TO AN
INCREASING AND SLIGHTLY BACKING SW FLOW ALOFT FOR OUR REGION
TONIGHT INTO EARLY SUNDAY THAT APPEARS WILL SLOW THE COLD FRONTAL
PASSAGE. GUIDANCE CONSENSUS INDICATES PRECIPITATION MAY NOT EXIT
THE SE FA UNTIL SUNDAY AFTERNOON. AS A RESULT...MAINTAINED POPS
OVER EXTREME ERN PORTIONS OF THE FA INTO EARLY SUNDAY AFTERNOON.
BEHIND THE FRONT...A COOL DRY AIR HIGH PRESSURE AIR MASS WILL
SETTLE INTO OUR REGION. GUIDANCE SUGGESTS MIN TEMPS NEAR OR BELOW
FREEZING SUN AND MON NT. FROST/FREEZE PROGRAM FOR NWS CAE FA HAS
ENDED FOR THIS FALL SEASON.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
NEARLY ZONAL FLOW ALOFT TUESDAY...BUT WILL GIVE WAY TO A BUILDING
UPPER RIDGE OVER THE SOUTHEAST WEDNESDAY THROUGH FRIDAY. SURFACE
HIGH PRESSURE TO REMAIN OVER THE EASTERN SEABOARD. THIS WILL
MAINTAIN FAIR WEATHER FOR OUR REGION WITH MODERATING TEMPERATURES.
LATEST GFS INDICATING SURFACE FRONT SHIFTING EAST INTO THE
APPALACHIANS BY SATURDAY. BOTH GFS AND WPC GUIDANCE SUGGESTING
HIGH CHANCE POPS FOR SATURDAY...BUT GIVEN CURRENT
UNCERTAINTIES...FOR NOW WILL JUST MENTION SLIGHT CHANCE POPS FOR
SATURDAY.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE GENERALLY EXPECTED THROUGH THE 24 HR FORECAST
PERIOD.
AN UPPER TROUGH WILL APPROACH THE AREA THIS MORNING ALONG WITH A
COLD FRONT THAT IS EXPECTED TO CROSS THE REGION TODAY. MVFR CIGS
EARLIER HAVE SHIFTED TO THE EAST AS A BAND OF LIGHT RAIN CONTINUES
TO PUSH TOWARDS THE COAST. SHORTWAVE ENERGY LIFTING NORTHEASTWARD
FROM THE GULF COAST WILL BRING ANOTHER ROUND OF LIGHT RAIN TO THE
REGION...THOUGH IT IS EXPECTED TO MAINLY BE TO THE EAST OF THE
TERMINALS BUT COULD IMPACT OGB BRIEFLY LATER THIS MORNING WITH
SOME LIGHT RAIN. THERE IS A LOW POSSIBILITY MVFR CIGS COULD RETURN
AT TIMES THROUGH 15Z BUT CONFIDENCE WAS TOO LOW TO INCLUDE.
WINDS WILL PICK UP FROM THE NORTH AS THE FRONT CROSSES THE REGION
AFTER 13Z-15Z AND SKIES SHOULD BECOME LESS CLOUDY THIS AFTERNOON
AS DRY HIGH PRESSURE BUILDS INTO THE REGION FROM THE NORTHWEST.
EXTENDED AVIATION OUTLOOK...NO SIGNIFICANT IMPACTS EXPECTED
DURING THE REST OF THE OUTLOOK PERIOD.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
AVIATION...23
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
330 AM CST SUN NOV 22 2015
.SHORT TERM...(Today)
ISSUED AT 330 AM CST SUN NOV 22 2015
A very chilly start is on tap today due to the new snowfall.
Traditional cold spots from Altona to Lacon will see below zero
temps around sunrise. A 1028mb surface high pressure center will
pass just southwest of IL this morning. The ridge axis will progress
east of IL by 18z/Noon, allowing for surface winds to become
southerly this afternoon. Typically that means slightly warmer high
temps, but the new snow cover will keep temps a tick below potential
due to insolation going into melting the snow instead of sensible
heating. A band of altocumulus clouds is projected to move across
our northern counties today as well, with moisture mainly in the 850-
700mb layer per RAP and HRRR soundings. So a combination of snow pack
and cloud cover will limit highs north of I-74 to at or just below
freezing today. Southern areas with snow less than an inch should
see the sun help to melt off what feel on Saturday. High temps south
and southwest of Lincoln to Mattoon should reach the mid to upper
30s under sunny skies.
&&
.LONG TERM...(Tonight through Saturday)
ISSUED AT 330 AM CST SUN NOV 22 2015
Surface high pressure ridge from eastern Texas into the Ohio river
valley at sunset will shift se into the Gulf Coast States Monday.
Meanwhile upper level trof over the OH/TN river valleys at sunset to
track east to the Atlantic Coast Monday morning, while another short
wave track northeast of central IL tonight into early Monday
morning. This feature may produce some mid level clouds over mainly
ne areas tonight and diminish by Monday morning. SSW winds 8-15 mph
to starts to modify temperatures. Lows tonight in the mid to upper
20s with some lower 20s over far northern CWA (Knox, Stark &
Marshall counties) where deeper snow pack of 6-10 inches is. Highs
Monday range from upper 30s to near 40F over northern CWA where snow
pack lingering while upper 40s SW CWA and into southeast IL.
Upper level ridge into IL Tue and into the eastern states Wed to
continue fair weather with temperatures continuing to modify. Lows
Monday night in the mid to upper 20s again with SW CWA near 30F. May
need to watch for patchy fog possibly developing over snow pack of
northern CWA later Monday night into early Tue morning as wind gets
lighter and have snow melt on Monday. Highs Tue range from lower 40s
from I-74 north to lower 50s sw CWA. Highs Wed around 50F northern
CWA and mid 50s sw CWA. Have slight chances of showers over the IL
river valley west of I-55 by Wed afternoon. Even milder highs Thu in
the upper 50s to around 60F.
Strong cutoff upper level low/trof digs over the Rockies during Wed
and Thu while surface low pressure to eject ne from the Texas
panhandle into the western great lakes Thu night and brings a cold
front east across IL in the Thu night to Fri time frame. 00Z models
still differ on timing of this front but generally show increasing
chances of showers from nw to se during Wed night and Thu with
likely pops Thu night into Friday. Rainfall amounts of 1-1.50 inches
during that time. Then cooler and drier weather follow late this
week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Sunday night)
ISSUED AT 1100 PM CST SAT NOV 21 2015
VFR conditions are expected this forecast period. High pressure
will drift across the region through Sunday morning bringing very
cold conditions to the forecast area. A band of mid level clouds
over north central Iowa was tracking southeast and should be
tracking across west central Illinois after 10z and further east
after 13z. Bases of the clouds should range from 6000-9000 feet
into the afternoon hours but precip is not expected with this
weak upper level wave that will push across the forecast area
during the day. Westerly winds at 8 to 15 kts tonight will back
into a south to southwest direction on Sunday at 7 to 12 kts
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Smith
AREA FORECAST DISCUSSION
NWS GRAY ME
250 AM EST SUN NOV 22 2015
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH THE REGION ON TODAY AND A WEAK WAVE
OF LOW PRESSURE WILL MOVE NORTHEASTWARD ALONG THE FRONT DURING
THE DAY ALLOWING FOR SOME COASTAL RAIN LATER TODAY AND TONIGHT.
HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION MONDAY
MORNING WHILE LOW PRESSURE TRACKS TO OUR EAST. THE HIGH WILL
SHIFT OFFSHORE ON WEDNESDAY AND A BROAD UPPER LEVEL RIDGE BUILDS
OVER NEW ENGLAND. THIS WILL BRING ABOVE AVERAGE TEMPERATURES
THROUGH THE END OF THE WORK WEEK. HIGH PRESSURE WILL HOLD
OFFSHORE THROUGH FRIDAY AND THE NEXT CHANCE FOR RAIN WILL COME ON
SATURDAY AS A COLD FRONT ENTERS THE AREA.
&&
.NEAR TERM /THROUGH TODAY/...
A WEAK SYSTEM WILL MOVE NORTHEAST AND INTO CANADA THIS
MORNING...DRAGGING A COLD FRONT THROUGH THE REGION. A FEW
SCATTERED RAIN SHOWERS WILL CROSS THE REGION THIS
MORNING...HOWEVER MOST AREAS WILL REMAIN DRY. SOME OF THE RAIN
SHOWERS WILL MIX WITH A FEW SNOW SHOWERS ACROSS THE HIGHER
TERRAIN...MAINLY IN NEW HAMPSHIRE AND THE WESTERN MOUNTAINS OF
MAINE. MOST OTHER AREAS WILL REMAIN MILD WITH DAYTIME TEMPERATURES
REACHING THE 40S.
&&
.SHORT TERM /TONIGHT THROUGH 6 PM MONDAY/...
THE LATEST HRRR MODEL RUN CONTINUES TO SHOW PRECIPITATION BREAKING
OUT LATE THIS AFTERNOON AND THIS EVENING IN THE FORM OF SOME LIGHT
RAIN...MAINLY ALONG THE COASTLINE. THIS WILL BE TRIGGERED FROM
CYCLOGENESIS OFF THE MID ATLANTIC COASTLINE DURING THE DAY.
00Z GUIDANCE SUGGESTS THE MAJORITY OF THE PRECIPITATION WILL
REMAIN TO OUR EAST TONIGHT. HOWEVER...THERE HAS BEEN A TREND TO
SPILL THE RAINFALL BACK INTO OUR FORECAST AREA FROM RUN TO RUN AND
THIS TREND CONTINUES. HIGHEST RAINFALL AMOUNTS WILL BE A THIRD TO
A HALF INCH ALONG THE MIDCOAST REGION OF MAINE.
PTYPE...THERE WILL ALSO BE SOME AREAS ALONG THE MIDCOAST AND
INLAND NORTH AND EAST OF THE AUGUSTA AND WATERVILLE CORRIDOR THAT
HAS A TRANSITION TO SNOW LATE TONIGHT AND EARLY MONDAY. THIS AREA
WILL SEE COLD AIR ADVECTED INTO THE REGION WITH THE PASSAGE OF AN
H8 LOW AND THE APPROACH OF THE UPPER LEVEL TROUGH EARLY MONDAY.
THE SNOW WILL MAINLY STICK ACROSS ANY ELEVATED TERRAIN...AND AT
THIS TIME WE ARE EXPECTING A COATING TO AN INCH OF SNOW. A FEW
COMMUNITIES MAY PICK UP A COUPLE INCHES OF ACCUMULATION.
HAZARDS: SOME SLICK DRIVING MONDAY MORNING EASTERN SECTIONS.
GUSTY NORTHERLY WINDS AS WELL HOWEVER...NOT OVERLY WINDY WITH
GUSTS TO ABOUT 25 MPH. THERE MAY BE A SHARP GRADIENT TO THE
PRECIPITATION FROM WEST TO EAST NEAR THE PENOBSCOT RIVER VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
- COLD START TO THE FORECAST WITH TEMPS SLIGHTLY BELOW NORMAL
- WARMUP STARTS WED WITH HIGHS REACHING MID TO UPPER 50S BY FRI
- COLD FRONT WILL BRING CHANCE OF RAIN AND COOLER TEMPS NEXT
WEEKEND
OPERATIONAL MODEL GUIDANCE AND GFS/EURO ENSEMBLES ARE ACTUALLY
IN GOOD AGREEMENT THROUGH THE LONG TERM. WE START THE PERIOD
ON TUESDAY WITH AN ANOMALOUS 500MB TROUGH OVER NEW ENGLAND WITH
H500 ABOUT 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL. THE SAME IS
ALSO TRUE FOR T850. DUE TO THIS I DECIDED TO DROP LOW
TEMPERATURES A BIT BELOW THE MODEL CONSENSUS FOR TUESDAY MORNING.
THE GOOD NEWS IS THAT THE SLIGHTLY BELOW AVERAGE TEMPERATURES
WILL BE SHORT LIVED AND THE TROUGH IS QUICKLY REPLACED BY A BROAD
UPPER LEVEL RIDGE AND STRONG WARM AIR ADVECTION ALOFT. H500
TOWARDS THE END OF THE WORKWEEK ARE 2 - 3 STANDARD DEVIATIONS
ABOVE NORMAL AND T850 OF 1 - 2 STANDARD DEVIATIONS ABOVE. THIS
WILL LIKELY MEAN THAT WE SEE TEMPERATURES WELL ABOVE AVERAGE ON
THANKSGIVING DAY AND FRIDAY...WITH HIGHS CLIMBING INTO THE 50S
ACROSS SOUTHERN LOCATIONS.
THEREAFTER...COLD FRONTAL PASSAGE LOOKS LIKELY ON SATURDAY
AND SHOULD SPREAD SOME SHOWERS ACROSS THE AREA. DECIDED TO GO
WITH A GUIDANCE CONSENSUS BLEND FOR POP ON SATURDAY DUE TO SOME
MINOR VARIATIONS OF TIMING BETWEEN THE MODELS AT THIS TIME.
BEHIND THIS FRONT...STRONG COLD AIR ADVECTION WILL BRING A SHARP
CONTRAST TO TEMPERATURES COME SUNDAY...WITH FORECASTED HIGHS
SLIGHTLY BELOW AVERAGE.
&&
.AVIATION /08Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...AREAS OF IFR AND MVFR CONDITIONS THIS MORNING WITH
SOME LOW CLOUDS CROSSING THE REGION. CEILINGS WILL LIFT THIS
AFTERNOON. CLOUDS WILL LOWER AND THICKEN WITH RAIN ALONG THE COAST
TONIGHT INTO EARLY MONDAY...WITH SOME SNOW MIXING IN NEAR THE
CAPITAL DISTRICT.
LONG TERM...HIGH PRESSURE OVERHEAD SHOULD PROVIDE VFR CONDITIONS
THROUGHOUT THE FORECAST PERIOD.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORIES HAVE BEEN HOISTED FOR TONIGHT
INTO EARLY MONDAY. A NORTHERLY FLOW WILL INCREASE OVER THE WATERS.
STRONGEST GRADIENT WILL REMAIN EAST OF OUR AREA WHERE GALE WATCHES
REMAIN IN EFFECT. GUSTY WINDS AND CHOPPY SEAS WILL CONTINUE
THROUGHOUT THE DAY ON MONDAY.
LONG TERM...WILL LIKELY SEE SCA CONDITIONS CONTINUE INTO
TUESDAY MORNING AND EVEN THOUGH WINDS WILL DROP BELOW 25 KNOTS
LATER MONDAY NIGHT....SEAS WILL LIKELY STAY IN THE 5 TO 7FT RANGE
INTO TUESDAY MORNING. HIGH PRESSURE AND WEAK A GRADIENT SHOULD
PERSIST AFTER THAT AND NO OTHER FLAGS ARE EXPECTED AT THIS TIME.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 PM EST MONDAY
FOR ANZ150>154.
&&
$$
NEAR/SHORT TERM...CANNON
LONG TERM...KISTNER
AREA FORECAST DISCUSSION
NWS RALEIGH NC
405 AM EST SUN NOV 22 2015
.SYNOPSIS...A COLD FRONT WILL CROSS CENTRAL NC THIS MORNING. COOL
HIGH PRESSURE WILL THEN BUILD OVER THE REGION...LASTING THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 355 AM SUNDAY...
WARM/MOIST ADVECTION COUPLED WITH THE RIGHT ENTRANCE REGION OF A
150KT JET ALONG THE APPALACHIANS HAS LEAD TO THE DEVELOPMENT OF A
RAIN BAND PARALLEL TO AND JUST EAST OF I-95...WITH SOME NOTABLE
ENHANCEMENT OWING TO FGEN ASSOCIATED WITH AN APPROACHING COLD FRONT.
THE HIGHER RAINFALL AMOUNTS...UP TO HALF AN INCH AT GSB...ARE VERY
ISOLATED AND MOST LOCATIONS WILL SEE A TENTH OF AN INCH OR LESS. THE
COLD FRONT ITSELF IS JUST NOW MOVING THROUGH THE WESTERN PIEDMONT
AND WILL CONTINUE AN EASTWARD MARCH EARLY THIS MORNING. THE
BIGGEST UNCERTAINTY IN THE NEAR TERM IS THE POTENTIAL FOR ANOTHER
BAND OF PRECIP TO BREAK OUT NEAR THE SAVANNAH RIVER BASIN AND SPREAD
NORTH ACROSS THE NC COASTAL PLAIN....AS THE HRRR SUGGEST. THIS
SEEMS PLAUSIBLE GIVEN THE CONTINUED UPPER DIVERGENCE ASSOCIATED WITH
THE JET AND INCREASING DCVA ASSOCIATED WITH THE TROUGH APPROACHING
THE TN VALLEY. MOST OF THE LIFT WILL ACCORDING BE ALOFT...AND WITH
DRIER LOW-LEVEL AIR MOVING IN BEHIND THE COLD FRONT...THE ADDITIONAL
RAIN SHOULD BE LIGHTER. BECAUSE OF THIS...WE WILL HANG ONTO HIGHER
POPS A LITTLE LONGER FOR AREAS NEAR AND EAST OF I-95....WITH RAIN
FINALLY COMING TO AN END BY 18Z.
SKIES WILL CLEAR FROM WEST TO EAST TODAY...THOUGH HIGH CLOUDS WILL
CONTINUE TO STREAM NORTHEAST AS THE UPPER JET SLOWLY PULLS OUT. THIS
WILL ALLOW TEMPS TO RESPOND A LITTLE ACROSS THE WEST BEFORE STRONGER
COLD ADVECTION KICKS IN THIS AFTERNOON. CLOUDS AND LIGHT PRECIP
WILL HINDER HEATING MORE IN THE EAST. USING A BLEND OF HIRES AND
STATISTICAL GUIDANCE YIELDS HIGHS IN THE UPPER 40S TO AROUND 50.
COLD ADVECTION WILL CONTINUE TONIGHT AS HIGH PRESSURE OVER THE TN
VALLEY BUILDS EAST IN THE WAKE OF THE LIFTING UPPER TROUGH. LOW-
LEVEL THICKNESSES BOTTOM OUT NEAT 1280M BY 12Z MONDAY...SUGGESTING
20S FOR NEARLY ALL OF THE CWA. CHANCES FOR DECOUPLING AND EXTRA
COOLING WILL BE GREATEST IN THE WEST BUT LIKELY VERY LATE...SO WILL
STICK WITH LOWS CLOSE TO STATISTICAL GUIDANCE IN THE MID 20S WEST TO
NEAR 30 EAST.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 355 AM SUNDAY...
HIGH PRESSURE WILL CONTINUE TO SLOWLY EXPAND OVER THE REGION ON
MONDAY BENEATH WEST-NORTHWEST FLOW ALOFT. A LOW-LEVEL THICKNESS
NEAR 1280M MONDAY MORNING CORRELATES TO CHILLY HIGHS IN THE MID AND
UPPER 40S UNDER FULL SUN. GIVEN MODEST NORTHWEST FLOW
CONTINUING INTO MONDAY NIGHT... MODELS SHOW A DECENT SIGNAL FOR
OROGRAPHICALLY ENHANCED CIRRUS LATE MONDAY NIGHT...MAINLY FROM THE
NORTHWEST PIEDMONT INTO VA. HARD TO SAY IF THIS WOULD HAVE ANY
IMPACTS ON LOWS...WHICH SHOULD BE IN THE UPPER 20S... AND SOME MID
20S FOR OUTLYING AREAS...UNDER OTHERWISE GOOD RADIATIONAL COOLING
CONDITIONS.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 400 AM SUNDAY..
IN BRIEF QUASI-ZONAL MID-LATITUDE FLOW...A PAIR OF UPPER LOWS OFF
THE NORTH AND SOUTH COASTS OF CA THIS MORNING...ARE FORECAST TO MOVE
IN SOMEWHAT-PHASED FASHION EAST ACROSS THE SOUTHEAST US LATE TUE
THROUGH WED...AT WHICH TIME CONSIDERABLE HIGH CLOUDINESS APPEARS
PROBABLE. ALTHOUGH HIGH LEVEL MOISTURE PROGS FROM BOTH THE GFS AND
ECMWF DEPICT HIGH VALUES OF RH CENTERED AROUND 300 MB...IT IS OFTEN
TIMES DIFFICULT TO TRULY ASCERTAIN JUST HOW OPAQUE THE ASSOCIATED
CIRRUS WILL BE UNTIL ABOUT 24 HOURS OUT...WHEN THE UPSTREAM
SATELLITE PRESENTATION CAN BETTER CORROBORATE THOSE MOISTURE
FORECASTS. AS SUCH...TEMPERATURES TUE NIGHT-WED...WHEN THE CIRRUS
SHOULD BE MAXIMIZED...HAVE BEEN ADJUSTED TO REFLECT A FEW DEGREE
LOWER DIURNAL RANGE (IE. LOWS TUE NIGHTNUDGED UP AND HIGHS WED
NUDGED DOWN A DEGREE OR TWO). THESE MAY NEED FURTHER MODIFICATION
ONCE IT BECOMES CLEARER HOW IMPACTFUL THE CIRRUS WILL BECOME.
OTHERWISE...THE TRANSITION TO A STRONG RIDGE FROM THE GULF OF MEXICO
TO THE WESTERN NORTH ATLANTIC AND A DEEP UPPER LOW INITIALLY OVER
THE INTERMOUNTAIN WEST WILL CONTINUE THROUGH MID-LATE WEEK...WITH AN
EASTWARD PROGRESSION OF THAT TROUGH/RIDGE COUPLET THROUGH NEXT
WEEKEND.
AT THE SURFACE...CONTINENTAL POLAR HIGH PRESSURE WILL EXPAND
EASTWARD INTO THE SOUTHEASTERN AND MIDDLE ATLANTIC STATES EARLY IN
THE WEEK...THEN STRENGTHEN SIGNIFICANTLY -BENEATH THE AFOREMENTIONED
STRONG AND AMPLIFIED RIDING ALOFT OVER THE EASTERN US- TO NEAR 1050
MB INVOF NOVA SCOTIA BY THU MORNING. THE RIDGE...WHICH WILL CONTINUE
TO SPAN THE LENGTH OF THE EAST COAST...WILL THEN WEAKEN/BREAK DOWN
IN ADVANCE OF A STRONG FRONTAL ZONE ACCOMPANYING THE AMPLIFIED
TROUGH ALOFT...WHICH NWP GUIDANCE GENERALLY AGREES WILL CROSS NC
EARLY NEXT WEEKEND.
TEMPERATURES DURING THE PERIOD WILL DISPLAY A WIDER THAN AVG RANGE
FROM EAST TO WEST OWING TO THE POTENTIAL FOR 925-850 MB
MOISTURE...IN ESE FLOW IN THAT LAYER...TO BANK AGAINST THE MOUNTAINS
AND SPREAD EAST ACROSS THE FOOTHILLS/WESTERN PIEDMONT BY THU-FRI.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 1255 AM SUNDAY...
PERIODS OF LIGHT RAIN WILL CONTINUE ACROSS EASTERN NC THIS
MORNING...LEADING TO MAINLY MVFR CEILINGS AT KFAY...THOUGH A HEAVY
PATCH OR TWO OF RAIN CAUSE SOME TEMPORARY IFR VSBYS. RADAR IMAGERY
SUGGESTS THE BULK OF THE RAIN WILL STAY EAST OF KRDU...AND MAY EVEN
STAY EAST KRWI FOR THE MOST PART. THUS...ANY IMPACTS ARE EXPECTED
TO BE OF SHORTER DURATION AT THIS TERMINALS THIS MORNING.
MEANWHILE...A COLD FRONT JUST NOW MOVING EAST OF THE APPALACHIANS
WILL SWEEP ACROSS CENTRAL NC BETWEEN 07Z AND 13Z. MVFR CEILINGS
HAVE DEVELOP IN THE FOOTHILLS AND WESTERN PIEDMONT AND ARE EXPECTED
TO CONTINUE FOR A FEW MORE HOURS...LIKELY BEING ERODED BY THE FRONT
AFTER 09Z. THIS SAME MOISTURE COULD ALSO CAUSE A SHORT PERIOD OF
MVFR CEILINGS AT KRDU BEFORE WINDS SHIFT TO NORTHWESTERLY AND DRIER
AIR BEGINS FILTER ACROSS THE AREA. THE BIGGEST UNCERTAINTY IN THE
FORECAST LIES IN THE POSSIBILITY IF A ANOTHER BAND OF LIGHT RAIN
THAT NEAR TERM GUIDANCE SHOWS SPREADING ACROSS EASTERN SC AND
NC...WHICH COULD EXTENDING THE BORDERLINE MVFR/VFR CONDITIONS
THROUGH THE MORNING HOURS....WITH MUCH HIGHER CONFIDENCE IN VFR
CONDITIONS AFTER 18Z. BEHIND THE AFOREMENTIONED COLD
FRONT...NORTHWEST WINDS WILL GUST TO AROUND 20KT THIS AFTERNOON
BEFORE HIGH PRESSURE BEGINS TO BUILD OVER THE REGION TONIGHT.
OUTLOOK...HIGH PRESSURE WILL THEN DOMINATE FOR THE REMAINDER OF THE
PERIOD...THUS VFR CONDITIONS WILL PREVAIL THROUGH THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...22
NEAR TERM...22
SHORT TERM...22
LONG TERM...26
AVIATION...22
AREA FORECAST DISCUSSION
NWS RALEIGH NC
355 AM EST SUN NOV 22 2015
.SYNOPSIS...A COLD FRONT WILL CROSS CENTRAL NC THIS MORNING. COOL
HIGH PRESSURE WILL THEN BUILD OVER THE REGION...LASTING THROUGH
EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 355 AM SUNDAY...
WARM/MOIST ADVECTION COUPLED WITH THE RIGHT ENTRANCE REGION OF A
150KT JET ALONG THE APPALACHIANS HAS LEAD TO THE DEVELOPMENT OF A
RAIN BAND PARALLEL TO AND JUST EAST OF I-95...WITH SOME NOTABLE
ENHANCEMENT OWING TO FGEN ASSOCIATED WITH AN APPROACHING COLD FRONT.
THE HIGHER RAINFALL AMOUNTS...UP TO HALF AN INCH AT GSB...ARE VERY
ISOLATED AND MOST LOCATIONS WILL SEE A TENTH OF AN INCH OR LESS. THE
COLD FRONT ITSELF IS JUST NOW MOVING THROUGH THE WESTERN PIEDMONT
AND WILL CONTINUE AN EASTWARD MARCH EARLY THIS MORNING. THE
BIGGEST UNCERTAINTY IN THE NEAR TERM IS THE POTENTIAL FOR ANOTHER
BAND OF PRECIP TO BREAK OUT NEAR THE SAVANNAH RIVER BASIN AND SPREAD
NORTH ACROSS THE NC COASTAL PLAIN....AS THE HRRR SUGGEST. THIS
SEEMS PLAUSIBLE GIVEN THE CONTINUED UPPER DIVERGENCE ASSOCIATED WITH
THE JET AND INCREASING DCVA ASSOCIATED WITH THE TROUGH APPROACHING
THE TN VALLEY. MOST OF THE LIFT WILL ACCORDING BE ALOFT...AND WITH
DRIER LOW-LEVEL AIR MOVING IN BEHIND THE COLD FRONT...THE ADDITIONAL
RAIN SHOULD BE LIGHTER. BECAUSE OF THIS...WE WILL HANG ONTO HIGHER
POPS A LITTLE LONGER FOR AREAS NEAR AND EAST OF I-95....WITH RAIN
FINALLY COMING TO AN END BY 18Z.
SKIES WILL CLEAR FROM WEST TO EAST TODAY...THOUGH HIGH CLOUDS WILL
CONTINUE TO STREAM NORTHEAST AS THE UPPER JET SLOWLY PULLS OUT. THIS
WILL ALLOW TEMPS TO RESPOND A LITTLE ACROSS THE WEST BEFORE STRONGER
COLD ADVECTION KICKS IN THIS AFTERNOON. CLOUDS AND LIGHT PRECIP
WILL HINDER HEATING MORE IN THE EAST. USING A BLEND OF HIRES AND
STATISTICAL GUIDANCE YIELDS HIGHS IN THE UPPER 40S TO AROUND 50.
COLD ADVECTION WILL CONTINUE TONIGHT AS HIGH PRESSURE OVER THE TN
VALLEY BUILDS EAST IN THE WAKE OF THE LIFTING UPPER TROUGH. LOW-
LEVEL THICKNESSES BOTTOM OUT NEAT 1280M BY 12Z MONDAY...SUGGESTING
20S FOR NEARLY ALL OF THE CWA. CHANCES FOR DECOUPLING AND EXTRA
COOLING WILL BE GREATEST IN THE WEST BUT LIKELY VERY LATE...SO WILL
STICK WITH LOWS CLOSE TO STATISTICAL GUIDANCE IN THE MID 20S WEST TO
NEAR 30 EAST.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 355 AM SUNDAY...
HIGH PRESSURE WILL CONTINUE TO SLOWLY EXPAND OVER THE REGION ON
MONDAY BENEATH WEST-NORTHWEST FLOW ALOFT. A LOW-LEVEL THICKNESS
NEAR 1280M MONDAY MORNING CORRELATES TO CHILLY HIGHS IN THE MID AND
UPPER 40S UNDER FULL SUN. GIVEN MODEST NORTHWEST FLOW
CONTINUING INTO MONDAY NIGHT... MODELS SHOW A DECENT SIGNAL FOR
OROGRAPHICALLY ENHANCED CIRRUS LATE MONDAY NIGHT...MAINLY FROM THE
NORTHWEST PIEDMONT INTO VA. HARD TO SAY IF THIS WOULD HAVE ANY
IMPACTS ON LOWS...WHICH SHOULD BE IN THE UPPER 20S... AND SOME MID
20S FOR OUTLYING AREAS...UNDER OTHERWISE GOOD RADIATIONAL COOLING
CONDITIONS.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 305 PM SATURDAY..
THE MID LEVEL FLOW PATTERN WILL BECOME MORE AMPLIFIED ONCE AGAIN
ACROSS THE CONUS MID TO LATE WEEK... WITH STRONG MID LEVEL RIDGING
BUILDING ACROSS OUR AREA AND HOLDING ACROSS OUR REGION THROUGH THE
REMAINDER OF THE WEEK. SURFACE HIGH PRESSURE WILL SHIFT OFF THE MID-
ATLANTIC/NORTHEAST U.S. COAST ON WEDNESDAY... BUT CONTINUE TO RIDGE
INTO OUR REGION. THIS WILL YIELD CONTINUED DRY WEATHER... BUT
CONTINUED SLOWLY MODIFYING/MOISTENING LOW LEVEL AIRMASS. HIGH TEMPS
ARE EXPECTED TO REBOUND FROM THE 50S ON WEDNESDAY TO THE 60S BY
FRIDAY. LOWS ARE EXPECTED TO FOLLOW A SIMILAR TREND... WITH LOWS IN
THE UPPER 30S NW TO MID 40S SE ON THURSDAY MORNING TO THE LOWER 40S
NW TO THE UPPER 40S SE ON FRIDAY MORNING.
THE RIDGE BEGINS TO BREAK DOWN/SHIFT EASTWARD FRIDAY NIGHT INTO NEXT
WEEKEND... ALLOWING A FRONT TO APPROACH/MOVE INTO THE REGION. MODELS
CONTINUE TO STRUGGLE AS TO WHEN THE FRONT WILL MOVE INTO CENTRAL NC
AND HOW MUCH MOISTURE AND LIFT WILL BE PRESENT. THUS... WILL STICK
CLOSE TO WPC`S TIMING/FORECAST... WITH LOW POPS AT THIS TIME GIVEN
CONFIDENCE FOR SATURDAY. EXPECT LOW TEMPS IN THE MID TO UPPER 40S
SUNDAY NIGHT... WITH HIGHS SATURDAY IN ADVANCE OF THE FRONT IN THE
LOWER 60 NW TO UPPER 60S SE.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
AS OF 1255 AM SUNDAY...
PERIODS OF LIGHT RAIN WILL CONTINUE ACROSS EASTERN NC THIS
MORNING...LEADING TO MAINLY MVFR CEILINGS AT KFAY...THOUGH A HEAVY
PATCH OR TWO OF RAIN CAUSE SOME TEMPORARY IFR VSBYS. RADAR IMAGERY
SUGGESTS THE BULK OF THE RAIN WILL STAY EAST OF KRDU...AND MAY EVEN
STAY EAST KRWI FOR THE MOST PART. THUS...ANY IMPACTS ARE EXPECTED
TO BE OF SHORTER DURATION AT THIS TERMINALS THIS MORNING.
MEANWHILE...A COLD FRONT JUST NOW MOVING EAST OF THE APPALACHIANS
WILL SWEEP ACROSS CENTRAL NC BETWEEN 07Z AND 13Z. MVFR CEILINGS
HAVE DEVELOP IN THE FOOTHILLS AND WESTERN PIEDMONT AND ARE EXPECTED
TO CONTINUE FOR A FEW MORE HOURS...LIKELY BEING ERODED BY THE FRONT
AFTER 09Z. THIS SAME MOISTURE COULD ALSO CAUSE A SHORT PERIOD OF
MVFR CEILINGS AT KRDU BEFORE WINDS SHIFT TO NORTHWESTERLY AND DRIER
AIR BEGINS FILTER ACROSS THE AREA. THE BIGGEST UNCERTAINTY IN THE
FORECAST LIES IN THE POSSIBILITY IF A ANOTHER BAND OF LIGHT RAIN
THAT NEAR TERM GUIDANCE SHOWS SPREADING ACROSS EASTERN SC AND
NC...WHICH COULD EXTENDING THE BORDERLINE MVFR/VFR CONDITIONS
THROUGH THE MORNING HOURS....WITH MUCH HIGHER CONFIDENCE IN VFR
CONDITIONS AFTER 18Z. BEHIND THE AFOREMENTIONED COLD
FRONT...NORTHWEST WINDS WILL GUST TO AROUND 20KT THIS AFTERNOON
BEFORE HIGH PRESSURE BEGINS TO BUILD OVER THE REGION TONIGHT.
OUTLOOK...HIGH PRESSURE WILL THEN DOMINATE FOR THE REMAINDER OF THE
PERIOD...THUS VFR CONDITIONS WILL PREVAIL THROUGH THURSDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...22
NEAR TERM...22
SHORT TERM...22
LONG TERM...BSD
AVIATION...22
AREA FORECAST DISCUSSION
NWS TAUNTON MA
959 AM EST SUN NOV 22 2015
.SYNOPSIS...
A COLD FRONT MOVES THROUGH FROM WEST TO EAST LATE TONIGHT AND
SUNDAY...BRINGING SCATTERED SHOWERS. LOW PRESSURE THEN DEVELOPS ON
THE FRONT MOVING UP THE EASTERN SEABOARD AND BRINGING A PERIOD OF
RAIN TO THE CAPE AND ISLANDS SUNDAY NIGHT INTO MONDAY MORNING.
HIGH PRESSURE RETURNS TO THE AREA MONDAY EVENING THROUGH FRIDAY.
A COLD FRONT MOVES THROUGH SOUTHERN NEW ENGLAND SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
NOTING A FOCUSED AREA OF DEFORMATION ACTING UPON INCREASED
MOISTURE FLUX AHEAD OF A PRECIP SHIELD S OF LI. THIS HAS MANIFEST
ITSELF AS SOME SHRA MAINLY ACROSS E MA NEAR AND E OF THE I-495
CORRIDOR. IN THE MEANTIME THE SRN PRECIP SHIELD CONTINUES TO
BLOSSOM AND MESOSCALE GUIDANCE IS CATCHING UP. POPS WERE UPDATED
TO REFLECT MAINLY A BLEND OF THE HRRR AND RAW RAP DATA...TRYING TO
BETTER REFINE THE GRADIENT BETWEEN THE HAVES AND HAVE NOTS FOR
THIS AFTERNOON AND EVENING. OTHER UPDATES WERE TO LOWER TEMPS A
BIT ACROSS THE ERN HALF OF THE REGION. LOW DWPTS SUGGEST ROOM FOR
RADIATIONAL COOLING...AND THESE AREAS WILL ALSO REMAIN CLOUDY
THROUGH THE DAYLIGHT PERIOD.
PREVIOUS DISCUSSION...
A COLD FRONT WILL CROSS SOUTHERN NEW ENGLAND TODAY. THIS FRONT
WILL PROVIDE A FOCUS FOR SOME SHOWERS...MAINLY ACROSS CT...RI AND
SOUTHEAST MA. KEPT AT LEAST A CHANCE OF SHOWERS IN THIS REGION FOR
THIS MORNING.
SYNOPTIC INGREDIENTS STILL IN PLACE FOR CYCLOGENESIS ALONG THIS
COLD FRONT OFF THE MID ATLANTIC COAST LATER TODAY. THIS SECONDARY
LOW PRESSURE WILL MOVE NORTH ALONG THE FRONTAL BOUNDARY...AND SLOW
ITS EASTWARD PROGRESS. THIS WAVE WILL APPROACH THE BENCHMARK VERY
LATE TODAY. THE INCREASED SURFACE CONVERGENCE SHOULD BE ENOUGH TO
GENERATE A MORE WIDESPREAD RAINFALL TOWARD SOUTHEAST MA LATER
TODAY. EXPECTING A VERY SHARP WESTERN CUTOFF TO THE RAINFALL
SHIELD. NOT VERY CONFIDENT WHERE THAT WILL ESTABLISH RIGHT NOW. SO
WILL EXTEND A CHANCE OF RAINFALL WEST INTO NORTHEAST CT AND
CENTRAL MA. THIS MAY HAVE TO BE REFINED WITH LATER FORECASTS.
SEASONABLE TEMPERATURES ANTICIPATED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
TONIGHT...
AN OFFSHORE LOW PRESSURE WILL MAKE ITS CLOSEST APPROACH TO
SOUTHERN NEW ENGLAND TONIGHT. ONE LAST BURST OF MODERATE RAIN IS
EXPECTED UNTIL THIS LOW PRESSURE MOVES BY. FINAL STORM TOTALS
COULD REACH 1.0-1.5 INCHES ACROSS CAPE/ISLANDS...BUT AS MENTIONED
ABOVE...THERE IS LIKELY TO BE A VERY TIGHT QPF GRADIENT. WILL BE A
RACE BETWEEN THE DRYING AND COLD ADVECTION AS TO WHETHER A BRIEF
PERIOD OF FROZEN PRECIP IS OBSERVED BEFORE IT FINALLY COMES TO AN
END...BUT AT THIS TIME SOUNDINGS SUGGEST THE DRYING WILL WIN...SO
MAINTAIN ONLY LIQUID PRECIP.
TEMPERATURES SHOULD FALL QUICKLY OVER THE THE INTERIOR WITH
CLEARING SKIES. TIGHTER TEMPERATURE GRADIENT TOWARDS THE COAST.
MONDAY...
CLOUDS AND RAIN SHOULD BE EXITING THE OUTER CAPE EARLY MONDAY.
OTHERWISE DRIER AND BLUSTERY WEATHER FOLLOWS. HIGH PRESSURE WELL
TO OUR SOUTH WILL RESULT IN PERSISTENT NORTHWEST WINDS AND MODEST
COLD AIR ADVECTION. EXPECTING TEMPERATURES ABOUT 10 DEGREES LOWER
THAN SUNDAY...DESPITE PLENTY OF SUNSHINE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* SEASONABLY COOL OR BELOW NORMAL TEMPS TUE
* DRY WEATHER WITH A MODERATING TEMPERATURE TREND THROUGH THE END OF
THE WEEK
* A COLD FRONT MOVES THROUGH SATURDAY PROVIDING A CHANCE OF PRECIP
MONDAY NIGHT THROUGH TUESDAY...EXCELLENT AGREEMENT AMONGST THE
MODELS WITH HIGH PRESSURE BUILDING OVER SOUTHERN NEW ENGLAND.
TEMPERATURES WILL BE BELOW NORMAL DURING THIS TIME FRAME...BUT DRY
WEATHER IS EXPECTED.
WEDNESDAY THROUGH FRIDAY...THERE IS VERY GOOD AGREEMENT AMONGST THE
MODELS ON THIS TIME PERIOD. DRY WEATHER IS EXPECTED AS HIGH
PRESSURE MOVES SLOWLY INTO THE MARITIMES WEDNESDAY. TEMPERATURES
WILL MODERATE THROUGH THE REMAINDER OF THE WEEK WITH TEMPERATURES
WELL ABOVE NORMAL ON THANKSGIVING AND FRIDAY.
SATURDAY...AN UPPER LEVEL TROUGH MOVES OVER SOUTHERN NEW ENGLAND. AT
THE SAME TIME...LOW PRESSURE MOVES FROM QUEBEC INTO THE
MARITIMES...BRINGING A COLD FRONT THROUGH THE REGION. THIS WILL
PROVIDE A CHANCE FOR PRECIPITATION ACROSS THE AREA. AT THIS
POINT...TEMPERATURES ARE SUCH THAT THIS WILL LIKELY BE RAIN. PRIOR
TO THE FRONT COMING THROUGH...WE WILL SEE CONTINUED WARMER THAN
NORMAL TEMPERATURES FROM THANKSGIVING AND FRIDAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY/...
TODAY AND TONIGHT...MODERATE CONFIDENCE DUE TO TIMING ISSUES.
MVFR/IFR EARLY WILL GIVE WAY TO VFR THROUGH THE MORNING HOURS FOR
CT/WESTERN AND CENTRAL MA...THEN NE MA/RI BY EARLY AFTERNOON.
AREAS ACROSS SE MA ARE LIKELY TO STAY MVFR/IFR AS A MORE STEADY
RAINFALL DEVELOPS AND CONTINUES LATE THIS AFTERNOON AND TONIGHT.
EXPECTING A TIGHT GRADIENT BETWEEN MVFR/IFR OVER THE CAPE AND
ISLANDS...AND VFR FARTHER NORTHWEST.
MONDAY...HIGH CONFIDENCE. MAINLY VFR. LOW PROBABILITY OF MVFR
CONDITIONS IN SHOWERS ACROSS THE CAPE AND ISLANDS EARLY. OTHERWISE
DRY WITH GUSTY NW WINDS 15 TO 25 KT.
KBOS TAF...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN EXACT
TIMING.
KBDL TAF...HIGH CONFIDENCE IN TRENDS...LOWER CONFIDENCE IN EXACT
TIMING.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...
HIGH CONFIDENCE. VFR/DRY WEATHER AND GOOD VSBY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY/...HIGH CONFIDENCE.
A BRIEF LULL IN SMALL CRAFT ADVISORY CONDITIONS ACROSS MOST WATERS
THIS MORNING. INCREASING SOUTHERLY SWELL WILL REACH NEAR 5 FT
AGAIN BY THIS EVENING. AS A COLD FRONT MOVES OFFSHORE...NW WINDS
ALSO INCREASE 25-30 KT TONIGHT. THE ONLY CAVEAT REMAINS BOSTON
HARBOR DUE TO UNCERTAINTY IN WIND STRENGTH AND ITS DURATION.
MONDAY...GUSTY NNW WINDS 20 TO 30 KT...STRONGEST WIND ACROSS THE
EASTERN MA WATERS. ROUGH SEAS EXPECTED. VSBY MAY LOWER EARLY IN
RAIN THEN IMPROVING QUICKLY.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...HIGH CONFIDENCE.
MONDAY NIGHT THROUGH THURSDAY...HIGH PRESSURE BUILDS INTO SOUTHERN
NEW ENGLAND AND THE COASTAL WATERS. NORTHWESTERLY WINDS DIMINISH
QUICKLY SWITCHING TO SOUTHEASTERLY TUESDAY NIGHT. SEAS SLOWLY
DIMINISH. SMALL CRAFT ADVISORIES WILL LIKELY STILL BE NEEDED FOR
MONDAY NIGHT AND POSSIBLY TUESDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR ANZ231>234.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
MONDAY FOR ANZ236.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST MONDAY
FOR ANZ235-237-251.
SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ250-254-255.
SMALL CRAFT ADVISORY FROM 1 PM THIS AFTERNOON TO 6 PM EST
MONDAY FOR ANZ256.
&&
$$
SYNOPSIS...BELK/RLG
NEAR TERM...BELK/DOODY
SHORT TERM...BELK
LONG TERM...RLG
AVIATION...BELK/RLG
MARINE...BELK/RLG
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
930 AM CST SUN NOV 22 2015
.UPDATE...
ISSUED AT 930 AM CST SUN NOV 22 2015
Short-wave trough embedded within broad northwesterly flow is
currently producing an area of mid-level clouds along/west of a
Chicago...to Peoria...to Columbia, Missouri line. These clouds
will spread eastward as the morning progresses. Have therefore
updated the sky grids to go with partly sunny wording across the
northern half of the KILX CWA. Have also adjusted hourly temps to
account for a faster diurnal temp rise across areas where little
or no snow is on the ground. Based on current temp trends and
expected arrival of mid-level cloud deck, have lowered afternoon
high temps by a degree or two along/north of I-74 where ample snow
cover exists. Highs will range from the upper 20s north of the
Peoria area...to the upper 30s around Jacksonville. Zone update
has already been issued.
&&
.SHORT TERM...(Today)
ISSUED AT 330 AM CST SUN NOV 22 2015
A very chilly start is on tap today due to the new snowfall.
Traditional cold spots from Altona to Lacon will see below zero
temps around sunrise. A 1028mb surface high pressure center will
pass just southwest of IL this morning. The ridge axis will progress
east of IL by 18z/Noon, allowing for surface winds to become
southerly this afternoon. Typically that means slightly warmer high
temps, but the new snow cover will keep temps a tick below potential
due to insolation going into melting the snow instead of sensible
heating. A band of altocumulus clouds is projected to move across
our northern counties today as well, with moisture mainly in the 850-
700mb layer per RAP and HRRR soundings. So a combination of snow pack
and cloud cover will limit highs north of I-74 to at or just below
freezing today. Southern areas with snow less than an inch should
see the sun help to melt off what feel on Saturday. High temps south
and southwest of Lincoln to Mattoon should reach the mid to upper
30s under sunny skies.
.LONG TERM...(Tonight through Saturday)
ISSUED AT 330 AM CST SUN NOV 22 2015
Surface high pressure ridge from eastern Texas into the Ohio river
valley at sunset will shift se into the Gulf Coast States Monday.
Meanwhile upper level trof over the OH/TN river valleys at sunset to
track east to the Atlantic Coast Monday morning, while another short
wave track northeast of central IL tonight into early Monday
morning. This feature may produce some mid level clouds over mainly
ne areas tonight and diminish by Monday morning. SSW winds 8-15 mph
to starts to modify temperatures. Lows tonight in the mid to upper
20s with some lower 20s over far northern CWA (Knox, Stark &
Marshall counties) where deeper snow pack of 6-10 inches is. Highs
Monday range from upper 30s to near 40F over northern CWA where snow
pack lingering while upper 40s SW CWA and into southeast IL.
Upper level ridge into IL Tue and into the eastern states Wed to
continue fair weather with temperatures continuing to modify. Lows
Monday night in the mid to upper 20s again with SW CWA near 30F. May
need to watch for patchy fog possibly developing over snow pack of
northern CWA later Monday night into early Tue morning as wind gets
lighter and have snow melt on Monday. Highs Tue range from lower 40s
from I-74 north to lower 50s sw CWA. Highs Wed around 50F northern
CWA and mid 50s sw CWA. Have slight chances of showers over the IL
river valley west of I-55 by Wed afternoon. Even milder highs Thu in
the upper 50s to around 60F.
Strong cutoff upper level low/trof digs over the Rockies during Wed
and Thu while surface low pressure to eject ne from the Texas
panhandle into the western great lakes Thu night and brings a cold
front east across IL in the Thu night to Fri time frame. 00Z models
still differ on timing of this front but generally show increasing
chances of showers from nw to se during Wed night and Thu with
likely pops Thu night into Friday. Rainfall amounts of 1-1.50 inches
during that time. Then cooler and drier weather follow late this
week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 536 AM CST SUN NOV 22 2015
VFR conditions are expected over the next 24 hours, as high
pressure passes across IL today. A period of VFR mid-clouds are
poised to progress across the northern half of IL today, generally
in the 7k-10k FT layer. Winds will start out light westerly, then
become south-southwest as the surface ridge axis moves east of
Illinois. Wind speeds look to remain in the 10-13kt range from
this afternoon through the evening.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Shimon
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
536 AM CST SUN NOV 22 2015
.SHORT TERM...(Today)
ISSUED AT 330 AM CST SUN NOV 22 2015
A very chilly start is on tap today due to the new snowfall.
Traditional cold spots from Altona to Lacon will see below zero
temps around sunrise. A 1028mb surface high pressure center will
pass just southwest of IL this morning. The ridge axis will progress
east of IL by 18z/Noon, allowing for surface winds to become
southerly this afternoon. Typically that means slightly warmer high
temps, but the new snow cover will keep temps a tick below potential
due to insolation going into melting the snow instead of sensible
heating. A band of altocumulus clouds is projected to move across
our northern counties today as well, with moisture mainly in the 850-
700mb layer per RAP and HRRR soundings. So a combination of snow pack
and cloud cover will limit highs north of I-74 to at or just below
freezing today. Southern areas with snow less than an inch should
see the sun help to melt off what feel on Saturday. High temps south
and southwest of Lincoln to Mattoon should reach the mid to upper
30s under sunny skies.
.LONG TERM...(Tonight through Saturday)
ISSUED AT 330 AM CST SUN NOV 22 2015
Surface high pressure ridge from eastern Texas into the Ohio river
valley at sunset will shift se into the Gulf Coast States Monday.
Meanwhile upper level trof over the OH/TN river valleys at sunset to
track east to the Atlantic Coast Monday morning, while another short
wave track northeast of central IL tonight into early Monday
morning. This feature may produce some mid level clouds over mainly
ne areas tonight and diminish by Monday morning. SSW winds 8-15 mph
to starts to modify temperatures. Lows tonight in the mid to upper
20s with some lower 20s over far northern CWA (Knox, Stark &
Marshall counties) where deeper snow pack of 6-10 inches is. Highs
Monday range from upper 30s to near 40F over northern CWA where snow
pack lingering while upper 40s SW CWA and into southeast IL.
Upper level ridge into IL Tue and into the eastern states Wed to
continue fair weather with temperatures continuing to modify. Lows
Monday night in the mid to upper 20s again with SW CWA near 30F. May
need to watch for patchy fog possibly developing over snow pack of
northern CWA later Monday night into early Tue morning as wind gets
lighter and have snow melt on Monday. Highs Tue range from lower 40s
from I-74 north to lower 50s sw CWA. Highs Wed around 50F northern
CWA and mid 50s sw CWA. Have slight chances of showers over the IL
river valley west of I-55 by Wed afternoon. Even milder highs Thu in
the upper 50s to around 60F.
Strong cutoff upper level low/trof digs over the Rockies during Wed
and Thu while surface low pressure to eject ne from the Texas
panhandle into the western great lakes Thu night and brings a cold
front east across IL in the Thu night to Fri time frame. 00Z models
still differ on timing of this front but generally show increasing
chances of showers from nw to se during Wed night and Thu with
likely pops Thu night into Friday. Rainfall amounts of 1-1.50 inches
during that time. Then cooler and drier weather follow late this
week.
&&
.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
ISSUED AT 536 AM CST SUN NOV 22 2015
VFR conditions are expected over the next 24 hours, as high
pressure passes across IL today. A period of VFR mid-clouds are
poised to progress across the northern half of IL today, generally
in the 7k-10k FT layer. Winds will start out light westerly, then
become south-southwest as the surface ridge axis moves east of
Illinois. Wind speeds look to remain in the 10-13kt range from
this afternoon through the evening.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Shimon
AREA FORECAST DISCUSSION
NWS GRAY ME
906 AM EST SUN NOV 22 2015
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH THE REGION ON TODAY AND A WEAK WAVE
OF LOW PRESSURE WILL MOVE NORTHEASTWARD ALONG THE FRONT DURING
THE DAY ALLOWING FOR SOME COASTAL RAIN LATER TODAY AND TONIGHT.
HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION MONDAY
MORNING WHILE LOW PRESSURE TRACKS TO OUR EAST. THE HIGH WILL
SHIFT OFFSHORE ON WEDNESDAY AND A BROAD UPPER LEVEL RIDGE BUILDS
OVER NEW ENGLAND. THIS WILL BRING ABOVE AVERAGE TEMPERATURES
THROUGH THE END OF THE WORK WEEK. HIGH PRESSURE WILL HOLD
OFFSHORE THROUGH FRIDAY AND THE NEXT CHANCE FOR RAIN WILL COME ON
SATURDAY AS A COLD FRONT ENTERS THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
9 AM UPDATE...HAVE ISSUED A SPECIAL WEATHER STATEMENT FOR
LOCALIZED FREEZING DRIZZLE IN SPOTS THROUGH ABOUT 1030 AM. MOST
LOCATIONS ARE AT OR ABOVE FREEZING...BUT A FEW MESONET OBS ARE
BETWEEN 30 AND 32 DEGREES AS OF 9 AM. SOME VERY LIGHT DRIZZLE IS
FALLING IN SPOTS. EVEN THOUGH ROADS SHOULD BE FAIRLY WARM...A FEW
SLICK SPOTS WILL BE POSSIBLE THROUGH ABOUT 1030 AM.
PREVIOUSLY...
LATEST HRRR CONTINUE TO BRING SOME LIGHT STEADY PRECIP TO THE
IMMEDIATE COAST DURING THE MID AFTERNOON HOURS. SOME SNOW MAY
POSSIBLY MIX IN WITH THE PRECIP LATER TONIGHT AS BOUNDARY LAYER
TEMPERATURES COOL WITH TIME.
PREV DISC...
A WEAK SYSTEM WILL MOVE NORTHEAST AND INTO CANADA
THIS MORNING...DRAGGING A COLD FRONT THROUGH THE REGION. A FEW
SCATTERED RAIN SHOWERS WILL CROSS THE REGION THIS
MORNING...HOWEVER MOST AREAS WILL REMAIN DRY. SOME OF THE RAIN
SHOWERS WILL MIX WITH A FEW SNOW SHOWERS ACROSS THE HIGHER
TERRAIN...MAINLY IN NEW HAMPSHIRE AND THE WESTERN MOUNTAINS OF
MAINE. MOST OTHER AREAS WILL REMAIN MILD WITH DAYTIME TEMPERATURES
REACHING THE 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE LATEST HRRR MODEL RUN CONTINUES TO SHOW PRECIPITATION BREAKING
OUT LATE THIS AFTERNOON AND THIS EVENING IN THE FORM OF SOME LIGHT
RAIN...MAINLY ALONG THE COASTLINE. THIS WILL BE TRIGGERED FROM
CYCLOGENESIS OFF THE MID ATLANTIC COASTLINE DURING THE DAY.
00Z GUIDANCE SUGGESTS THE MAJORITY OF THE PRECIPITATION WILL
REMAIN TO OUR EAST TONIGHT. HOWEVER...THERE HAS BEEN A TREND TO
SPILL THE RAINFALL BACK INTO OUR FORECAST AREA FROM RUN TO RUN AND
THIS TREND CONTINUES. HIGHEST RAINFALL AMOUNTS WILL BE A THIRD TO
A HALF INCH ALONG THE MIDCOAST REGION OF MAINE.
PTYPE...THERE WILL ALSO BE SOME AREAS ALONG THE MIDCOAST AND
INLAND NORTH AND EAST OF THE AUGUSTA AND WATERVILLE CORRIDOR THAT
HAS A TRANSITION TO SNOW LATE TONIGHT AND EARLY MONDAY. THIS AREA
WILL SEE COLD AIR ADVECTED INTO THE REGION WITH THE PASSAGE OF AN
H8 LOW AND THE APPROACH OF THE UPPER LEVEL TROUGH EARLY MONDAY.
THE SNOW WILL MAINLY STICK ACROSS ANY ELEVATED TERRAIN...AND AT
THIS TIME WE ARE EXPECTING A COATING TO AN INCH OF SNOW. A FEW
COMMUNITIES MAY PICK UP A COUPLE INCHES OF ACCUMULATION.
HAZARDS: SOME SLICK DRIVING MONDAY MORNING EASTERN SECTIONS.
GUSTY NORTHERLY WINDS AS WELL HOWEVER...NOT OVERLY WINDY WITH
GUSTS TO ABOUT 25 MPH. THERE MAY BE A SHARP GRADIENT TO THE
PRECIPITATION FROM WEST TO EAST NEAR THE PENOBSCOT RIVER VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
- COLD START TO THE FORECAST WITH TEMPS SLIGHTLY BELOW NORMAL
- WARMUP STARTS WED WITH HIGHS REACHING MID TO UPPER 50S BY FRI
- COLD FRONT WILL BRING CHANCE OF RAIN AND COOLER TEMPS NEXT
WEEKEND
OPERATIONAL MODEL GUIDANCE AND GFS/EURO ENSEMBLES ARE ACTUALLY
IN GOOD AGREEMENT THROUGH THE LONG TERM. WE START THE PERIOD
ON TUESDAY WITH AN ANOMALOUS 500MB TROUGH OVER NEW ENGLAND WITH
H500 ABOUT 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL. THE SAME IS
ALSO TRUE FOR T850. DUE TO THIS I DECIDED TO DROP LOW
TEMPERATURES A BIT BELOW THE MODEL CONSENSUS FOR TUESDAY MORNING.
THE GOOD NEWS IS THAT THE SLIGHTLY BELOW AVERAGE TEMPERATURES
WILL BE SHORT LIVED AND THE TROUGH IS QUICKLY REPLACED BY A BROAD
UPPER LEVEL RIDGE AND STRONG WARM AIR ADVECTION ALOFT. H500
TOWARDS THE END OF THE WORKWEEK ARE 2 - 3 STANDARD DEVIATIONS
ABOVE NORMAL AND T850 OF 1 - 2 STANDARD DEVIATIONS ABOVE. THIS
WILL LIKELY MEAN THAT WE SEE TEMPERATURES WELL ABOVE AVERAGE ON
THANKSGIVING DAY AND FRIDAY...WITH HIGHS CLIMBING INTO THE 50S
ACROSS SOUTHERN LOCATIONS.
THEREAFTER...COLD FRONTAL PASSAGE LOOKS LIKELY ON SATURDAY
AND SHOULD SPREAD SOME SHOWERS ACROSS THE AREA. DECIDED TO GO
WITH A GUIDANCE CONSENSUS BLEND FOR POP ON SATURDAY DUE TO SOME
MINOR VARIATIONS OF TIMING BETWEEN THE MODELS AT THIS TIME.
BEHIND THIS FRONT...STRONG COLD AIR ADVECTION WILL BRING A SHARP
CONTRAST TO TEMPERATURES COME SUNDAY...WITH FORECASTED HIGHS
SLIGHTLY BELOW AVERAGE.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...AREAS OF IFR AND MVFR CONDITIONS THIS MORNING WITH
SOME LOW CLOUDS CROSSING THE REGION. CEILINGS WILL LIFT THIS
AFTERNOON. CLOUDS WILL LOWER AND THICKEN WITH RAIN ALONG THE COAST
TONIGHT INTO EARLY MONDAY...WITH SOME SNOW MIXING IN NEAR THE
CAPITAL DISTRICT.
LONG TERM...HIGH PRESSURE OVERHEAD SHOULD PROVIDE VFR CONDITIONS
THROUGHOUT THE FORECAST PERIOD.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORIES HAVE BEEN HOISTED FOR TONIGHT
INTO EARLY MONDAY. A NORTHERLY FLOW WILL INCREASE OVER THE WATERS.
STRONGEST GRADIENT WILL REMAIN EAST OF OUR AREA WHERE GALE WATCHES
REMAIN IN EFFECT. GUSTY WINDS AND CHOPPY SEAS WILL CONTINUE
THROUGHOUT THE DAY ON MONDAY.
LONG TERM...WILL LIKELY SEE SCA CONDITIONS CONTINUE INTO
TUESDAY MORNING AND EVEN THOUGH WINDS WILL DROP BELOW 25 KNOTS
LATER MONDAY NIGHT....SEAS WILL LIKELY STAY IN THE 5 TO 7FT RANGE
INTO TUESDAY MORNING. HIGH PRESSURE AND WEAK A GRADIENT SHOULD
PERSIST AFTER THAT AND NO OTHER FLAGS ARE EXPECTED AT THIS TIME.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 PM EST MONDAY
FOR ANZ150>154.
&&
$$
NEAR TERM UPDATE...EKSTER
AREA FORECAST DISCUSSION
NWS GRAY ME
704 AM EST SUN NOV 22 2015
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH THE REGION ON TODAY AND A WEAK WAVE
OF LOW PRESSURE WILL MOVE NORTHEASTWARD ALONG THE FRONT DURING
THE DAY ALLOWING FOR SOME COASTAL RAIN LATER TODAY AND TONIGHT.
HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION MONDAY
MORNING WHILE LOW PRESSURE TRACKS TO OUR EAST. THE HIGH WILL
SHIFT OFFSHORE ON WEDNESDAY AND A BROAD UPPER LEVEL RIDGE BUILDS
OVER NEW ENGLAND. THIS WILL BRING ABOVE AVERAGE TEMPERATURES
THROUGH THE END OF THE WORK WEEK. HIGH PRESSURE WILL HOLD
OFFSHORE THROUGH FRIDAY AND THE NEXT CHANCE FOR RAIN WILL COME ON
SATURDAY AS A COLD FRONT ENTERS THE AREA.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE...
POCKETS OF LIGHT SLEET WITH A FEW SCATTERED RAIN AND SNOW SHOWERS
CONTINUES TO CROSS THE REGION THIS MORNING PER LATEST OBSERVATIONS
AND 88D IMAGERY.
LATEST HRRR CONTINUE TO BRING SOME LIGHT STEADY PRECIP TO THE
IMMEDIATE COAST DURING THE MID AFTERNOON HOURS. SOME SNOW MAY
POSSIBLY MIX IN WITH THE PRECIP LATER TONIGHT AS BOUNDARY LAYER
TEMPERATURES COOL WITH TIME.
PREV DISC...
A WEAK SYSTEM WILL MOVE NORTHEAST AND INTO CANADA
THIS MORNING...DRAGGING A COLD FRONT THROUGH THE REGION. A FEW
SCATTERED RAIN SHOWERS WILL CROSS THE REGION THIS
MORNING...HOWEVER MOST AREAS WILL REMAIN DRY. SOME OF THE RAIN
SHOWERS WILL MIX WITH A FEW SNOW SHOWERS ACROSS THE HIGHER
TERRAIN...MAINLY IN NEW HAMPSHIRE AND THE WESTERN MOUNTAINS OF
MAINE. MOST OTHER AREAS WILL REMAIN MILD WITH DAYTIME TEMPERATURES
REACHING THE 40S.
&&
.SHORT TERM /MONDAY/...
THE LATEST HRRR MODEL RUN CONTINUES TO SHOW PRECIPITATION BREAKING
OUT LATE THIS AFTERNOON AND THIS EVENING IN THE FORM OF SOME LIGHT
RAIN...MAINLY ALONG THE COASTLINE. THIS WILL BE TRIGGERED FROM
CYCLOGENESIS OFF THE MID ATLANTIC COASTLINE DURING THE DAY.
00Z GUIDANCE SUGGESTS THE MAJORITY OF THE PRECIPITATION WILL
REMAIN TO OUR EAST TONIGHT. HOWEVER...THERE HAS BEEN A TREND TO
SPILL THE RAINFALL BACK INTO OUR FORECAST AREA FROM RUN TO RUN AND
THIS TREND CONTINUES. HIGHEST RAINFALL AMOUNTS WILL BE A THIRD TO
A HALF INCH ALONG THE MIDCOAST REGION OF MAINE.
PTYPE...THERE WILL ALSO BE SOME AREAS ALONG THE MIDCOAST AND
INLAND NORTH AND EAST OF THE AUGUSTA AND WATERVILLE CORRIDOR THAT
HAS A TRANSITION TO SNOW LATE TONIGHT AND EARLY MONDAY. THIS AREA
WILL SEE COLD AIR ADVECTED INTO THE REGION WITH THE PASSAGE OF AN
H8 LOW AND THE APPROACH OF THE UPPER LEVEL TROUGH EARLY MONDAY.
THE SNOW WILL MAINLY STICK ACROSS ANY ELEVATED TERRAIN...AND AT
THIS TIME WE ARE EXPECTING A COATING TO AN INCH OF SNOW. A FEW
COMMUNITIES MAY PICK UP A COUPLE INCHES OF ACCUMULATION.
HAZARDS: SOME SLICK DRIVING MONDAY MORNING EASTERN SECTIONS.
GUSTY NORTHERLY WINDS AS WELL HOWEVER...NOT OVERLY WINDY WITH
GUSTS TO ABOUT 25 MPH. THERE MAY BE A SHARP GRADIENT TO THE
PRECIPITATION FROM WEST TO EAST NEAR THE PENOBSCOT RIVER VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
- COLD START TO THE FORECAST WITH TEMPS SLIGHTLY BELOW NORMAL
- WARMUP STARTS WED WITH HIGHS REACHING MID TO UPPER 50S BY FRI
- COLD FRONT WILL BRING CHANCE OF RAIN AND COOLER TEMPS NEXT
WEEKEND
OPERATIONAL MODEL GUIDANCE AND GFS/EURO ENSEMBLES ARE ACTUALLY
IN GOOD AGREEMENT THROUGH THE LONG TERM. WE START THE PERIOD
ON TUESDAY WITH AN ANOMALOUS 500MB TROUGH OVER NEW ENGLAND WITH
H500 ABOUT 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL. THE SAME IS
ALSO TRUE FOR T850. DUE TO THIS I DECIDED TO DROP LOW
TEMPERATURES A BIT BELOW THE MODEL CONSENSUS FOR TUESDAY MORNING.
THE GOOD NEWS IS THAT THE SLIGHTLY BELOW AVERAGE TEMPERATURES
WILL BE SHORT LIVED AND THE TROUGH IS QUICKLY REPLACED BY A BROAD
UPPER LEVEL RIDGE AND STRONG WARM AIR ADVECTION ALOFT. H500
TOWARDS THE END OF THE WORKWEEK ARE 2 - 3 STANDARD DEVIATIONS
ABOVE NORMAL AND T850 OF 1 - 2 STANDARD DEVIATIONS ABOVE. THIS
WILL LIKELY MEAN THAT WE SEE TEMPERATURES WELL ABOVE AVERAGE ON
THANKSGIVING DAY AND FRIDAY...WITH HIGHS CLIMBING INTO THE 50S
ACROSS SOUTHERN LOCATIONS.
THEREAFTER...COLD FRONTAL PASSAGE LOOKS LIKELY ON SATURDAY
AND SHOULD SPREAD SOME SHOWERS ACROSS THE AREA. DECIDED TO GO
WITH A GUIDANCE CONSENSUS BLEND FOR POP ON SATURDAY DUE TO SOME
MINOR VARIATIONS OF TIMING BETWEEN THE MODELS AT THIS TIME.
BEHIND THIS FRONT...STRONG COLD AIR ADVECTION WILL BRING A SHARP
CONTRAST TO TEMPERATURES COME SUNDAY...WITH FORECASTED HIGHS
SLIGHTLY BELOW AVERAGE.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...AREAS OF IFR AND MVFR CONDITIONS THIS MORNING WITH
SOME LOW CLOUDS CROSSING THE REGION. CEILINGS WILL LIFT THIS
AFTERNOON. CLOUDS WILL LOWER AND THICKEN WITH RAIN ALONG THE COAST
TONIGHT INTO EARLY MONDAY...WITH SOME SNOW MIXING IN NEAR THE
CAPITAL DISTRICT.
LONG TERM...HIGH PRESSURE OVERHEAD SHOULD PROVIDE VFR CONDITIONS
THROUGHOUT THE FORECAST PERIOD.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORIES HAVE BEEN HOISTED FOR TONIGHT
INTO EARLY MONDAY. A NORTHERLY FLOW WILL INCREASE OVER THE WATERS.
STRONGEST GRADIENT WILL REMAIN EAST OF OUR AREA WHERE GALE WATCHES
REMAIN IN EFFECT. GUSTY WINDS AND CHOPPY SEAS WILL CONTINUE
THROUGHOUT THE DAY ON MONDAY.
LONG TERM...WILL LIKELY SEE SCA CONDITIONS CONTINUE INTO
TUESDAY MORNING AND EVEN THOUGH WINDS WILL DROP BELOW 25 KNOTS
LATER MONDAY NIGHT....SEAS WILL LIKELY STAY IN THE 5 TO 7FT RANGE
INTO TUESDAY MORNING. HIGH PRESSURE AND WEAK A GRADIENT SHOULD
PERSIST AFTER THAT AND NO OTHER FLAGS ARE EXPECTED AT THIS TIME.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 PM EST MONDAY
FOR ANZ150>154.
&&
$$
AREA FORECAST DISCUSSION
NWS RALEIGH NC
645 AM EST SUN NOV 22 2015
.SYNOPSIS...A COLD FRONT WILL CROSS CENTRAL NC THIS MORNING. COOL
HIGH PRESSURE WILL THEN BUILD OVER THE REGION AND PERSIST THROUGH
THE FIRST HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 355 AM SUNDAY...
WARM/MOIST ADVECTION COUPLED WITH THE RIGHT ENTRANCE REGION OF A
150KT JET ALONG THE APPALACHIANS HAS LEAD TO THE DEVELOPMENT OF A
RAIN BAND PARALLEL TO AND JUST EAST OF I-95...WITH SOME NOTABLE
ENHANCEMENT OWING TO FGEN ASSOCIATED WITH AN APPROACHING COLD FRONT.
THE HIGHER RAINFALL AMOUNTS...UP TO HALF AN INCH AT GSB...ARE VERY
ISOLATED AND MOST LOCATIONS WILL SEE A TENTH OF AN INCH OR LESS. THE
COLD FRONT ITSELF IS JUST NOW MOVING THROUGH THE WESTERN PIEDMONT
AND WILL CONTINUE AN EASTWARD MARCH EARLY THIS MORNING. THE
BIGGEST UNCERTAINTY IN THE NEAR TERM IS THE POTENTIAL FOR ANOTHER
BAND OF PRECIP TO BREAK OUT NEAR THE SAVANNAH RIVER BASIN AND SPREAD
NORTH ACROSS THE NC COASTAL PLAIN....AS THE HRRR SUGGEST. THIS
SEEMS PLAUSIBLE GIVEN THE CONTINUED UPPER DIVERGENCE ASSOCIATED WITH
THE JET AND INCREASING DCVA ASSOCIATED WITH THE TROUGH APPROACHING
THE TN VALLEY. MOST OF THE LIFT WILL ACCORDING BE ALOFT...AND WITH
DRIER LOW-LEVEL AIR MOVING IN BEHIND THE COLD FRONT...THE ADDITIONAL
RAIN SHOULD BE LIGHTER. BECAUSE OF THIS...WE WILL HANG ONTO HIGHER
POPS A LITTLE LONGER FOR AREAS NEAR AND EAST OF I-95....WITH RAIN
FINALLY COMING TO AN END BY 18Z.
SKIES WILL CLEAR FROM WEST TO EAST TODAY...THOUGH HIGH CLOUDS WILL
CONTINUE TO STREAM NORTHEAST AS THE UPPER JET SLOWLY PULLS OUT. THIS
WILL ALLOW TEMPS TO RESPOND A LITTLE ACROSS THE WEST BEFORE STRONGER
COLD ADVECTION KICKS IN THIS AFTERNOON. CLOUDS AND LIGHT PRECIP
WILL HINDER HEATING MORE IN THE EAST. USING A BLEND OF HIRES AND
STATISTICAL GUIDANCE YIELDS HIGHS IN THE UPPER 40S TO AROUND 50.
COLD ADVECTION WILL CONTINUE TONIGHT AS HIGH PRESSURE OVER THE TN
VALLEY BUILDS EAST IN THE WAKE OF THE LIFTING UPPER TROUGH. LOW-
LEVEL THICKNESSES BOTTOM OUT NEAT 1280M BY 12Z MONDAY...SUGGESTING
20S FOR NEARLY ALL OF THE CWA. CHANCES FOR DECOUPLING AND EXTRA
COOLING WILL BE GREATEST IN THE WEST BUT LIKELY VERY LATE...SO WILL
STICK WITH LOWS CLOSE TO STATISTICAL GUIDANCE IN THE MID 20S WEST TO
NEAR 30 EAST.
&&
.SHORT TERM /MONDAY AND MONDAY NIGHT/...
AS OF 355 AM SUNDAY...
HIGH PRESSURE WILL CONTINUE TO SLOWLY EXPAND OVER THE REGION ON
MONDAY BENEATH WEST-NORTHWEST FLOW ALOFT. A LOW-LEVEL THICKNESS
NEAR 1280M MONDAY MORNING CORRELATES TO CHILLY HIGHS IN THE MID AND
UPPER 40S UNDER FULL SUN. GIVEN MODEST NORTHWEST FLOW
CONTINUING INTO MONDAY NIGHT... MODELS SHOW A DECENT SIGNAL FOR
OROGRAPHICALLY ENHANCED CIRRUS LATE MONDAY NIGHT...MAINLY FROM THE
NORTHWEST PIEDMONT INTO VA. HARD TO SAY IF THIS WOULD HAVE ANY
IMPACTS ON LOWS...WHICH SHOULD BE IN THE UPPER 20S... AND SOME MID
20S FOR OUTLYING AREAS...UNDER OTHERWISE GOOD RADIATIONAL COOLING
CONDITIONS.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 400 AM SUNDAY..
IN BRIEF QUASI-ZONAL MID-LATITUDE FLOW...A PAIR OF UPPER LOWS OFF
THE NORTH AND SOUTH COASTS OF CA THIS MORNING...ARE FORECAST TO MOVE
IN SOMEWHAT-PHASED FASHION EAST ACROSS THE SOUTHEAST US LATE TUE
THROUGH WED...AT WHICH TIME CONSIDERABLE HIGH CLOUDINESS APPEARS
PROBABLE. ALTHOUGH HIGH LEVEL MOISTURE PROGS FROM BOTH THE GFS AND
ECMWF DEPICT HIGH VALUES OF RH CENTERED AROUND 300 MB...IT IS OFTEN
TIMES DIFFICULT TO TRULY ASCERTAIN JUST HOW OPAQUE THE ASSOCIATED
CIRRUS WILL BE UNTIL ABOUT 24 HOURS OUT...WHEN THE UPSTREAM
SATELLITE PRESENTATION CAN BETTER CORROBORATE THOSE MOISTURE
FORECASTS. AS SUCH...TEMPERATURES TUE NIGHT-WED...WHEN THE CIRRUS
SHOULD BE MAXIMIZED...HAVE BEEN ADJUSTED TO REFLECT A FEW DEGREE
LOWER DIURNAL RANGE (IE. LOWS TUE NIGHT NUDGED UP AND HIGHS WED
NUDGED DOWN A DEGREE OR TWO). THESE MAY NEED FURTHER MODIFICATION
ONCE IT BECOMES CLEARER HOW IMPACTFUL THE CIRRUS WILL BECOME.
OTHERWISE...THE TRANSITION TO A STRONG RIDGE FROM THE GULF OF MEXICO
TO THE WESTERN NORTH ATLANTIC AND A DEEP UPPER LOW INITIALLY OVER
THE INTERMOUNTAIN WEST WILL CONTINUE THROUGH MID-LATE WEEK...WITH AN
EASTWARD PROGRESSION OF THAT TROUGH/RIDGE COUPLET THROUGH NEXT
WEEKEND.
AT THE SURFACE...CONTINENTAL POLAR HIGH PRESSURE WILL EXPAND
EASTWARD INTO THE SOUTHEASTERN AND MIDDLE ATLANTIC STATES EARLY IN
THE WEEK...THEN STRENGTHEN SIGNIFICANTLY -BENEATH THE AFOREMENTIONED
STRONG AND AMPLIFIED RIDING ALOFT OVER THE EASTERN US- TO NEAR 1050
MB INVOF NOVA SCOTIA BY THU MORNING. THE RIDGE...WHICH WILL CONTINUE
TO SPAN THE LENGTH OF THE EAST COAST...WILL THEN WEAKEN/BREAK DOWN
IN ADVANCE OF A STRONG FRONTAL ZONE ACCOMPANYING THE AMPLIFIED
TROUGH ALOFT...WHICH NWP GUIDANCE GENERALLY AGREES WILL CROSS NC
EARLY NEXT WEEKEND.
TEMPERATURES DURING THE PERIOD WILL DISPLAY A WIDER THAN AVG RANGE
FROM EAST TO WEST OWING TO THE POTENTIAL FOR 925-850 MB
MOISTURE...IN ESE FLOW IN THAT LAYER...TO BANK AGAINST THE MOUNTAINS
AND SPREAD EAST ACROSS THE FOOTHILLS/WESTERN PIEDMONT BY THU-FRI.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 645 AM SUNDAY...
WHILE A BAND OF RAIN EXITS THE COASTAL PLAIN THIS MORNING...A COLD
FRONT IS BEGINNING TO MAKE IT WAY THROUGH THE AREA...WITH DRIER AIR
ALREADY WORKING IN FROM THE WEST AND HELPING TO SCOUR EARLIER LOW
CLOUDS. ANOTHER BAND OF RAIN HAS BEEN SLOWLY EXPANDING OVER GEORGIA
AND EASTERN SC...WHICH SHOULD MOVE INTO EASTERN NC LATER THIS
MORNING. HOWEVER..THE COMBINATION OF LIGHTER RAIN RATES AND DRIER
LOW LEVEL AIR SHOULD KEEP CEILINGS FROM FALLING ANY LOWER THAN MVFR
AT MOST. THE CHANCE OF MVFR CEILINGS IS GREATEST AT KFAY BETWEEN
14Z AND 17Z...WITH LOWER CONFIDENCE AT KRWI. BEHIND THE
FRONT...WINDS WILL INCREASE TO 8-12KT AND GUST TO NEAR 20 KT AT
TIMES. VFR CONDITIONS ARE EXPECTED ACROSS ALL OF CENTRAL NC AFTER
18Z.
OUTLOOK...HIGH PRESSURE WILL REMAIN OVER THE REGION FOR MUCH OF THE
UPCOMING WEEK...WITH A PROLONGED PERIOD OF VFR CONDITIONS. THE NEXT
CHANCE OF SUB-VFR CONDITIONS WILL COME NEXT WEEKEND.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...22
NEAR TERM...22
SHORT TERM...22
LONG TERM...26
AVIATION...22
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1229 PM EST SUN NOV 22 2015
.SYNOPSIS...
A COLD FRONT MOVES THROUGH FROM WEST TO EAST LATE TONIGHT AND
SUNDAY...BRINGING SCATTERED SHOWERS. LOW PRESSURE THEN DEVELOPS ON
THE FRONT MOVING UP THE EASTERN SEABOARD AND BRINGING A PERIOD OF
RAIN TO THE CAPE AND ISLANDS SUNDAY NIGHT INTO MONDAY MORNING.
HIGH PRESSURE RETURNS TO THE AREA MONDAY EVENING THROUGH FRIDAY.
A COLD FRONT MOVES THROUGH SOUTHERN NEW ENGLAND SATURDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
10 AM UPDATE...
NOTING A FOCUSED AREA OF DEFORMATION ACTING UPON INCREASED
MOISTURE FLUX AHEAD OF A PRECIP SHIELD S OF LI. THIS HAS MANIFEST
ITSELF AS SOME SHRA MAINLY ACROSS E MA NEAR AND E OF THE I-495
CORRIDOR. IN THE MEANTIME THE SRN PRECIP SHIELD CONTINUES TO
BLOSSOM AND MESOSCALE GUIDANCE IS CATCHING UP. POPS WERE UPDATED
TO REFLECT MAINLY A BLEND OF THE HRRR AND RAW RAP DATA...TRYING TO
BETTER REFINE THE GRADIENT BETWEEN THE HAVES AND HAVE NOTS FOR
THIS AFTERNOON AND EVENING. OTHER UPDATES WERE TO LOWER TEMPS A
BIT ACROSS THE ERN HALF OF THE REGION. LOW DWPTS SUGGEST ROOM FOR
RADIATIONAL COOLING...AND THESE AREAS WILL ALSO REMAIN CLOUDY
THROUGH THE DAYLIGHT PERIOD.
PREVIOUS DISCUSSION...
A COLD FRONT WILL CROSS SOUTHERN NEW ENGLAND TODAY. THIS FRONT
WILL PROVIDE A FOCUS FOR SOME SHOWERS...MAINLY ACROSS CT...RI AND
SOUTHEAST MA. KEPT AT LEAST A CHANCE OF SHOWERS IN THIS REGION FOR
THIS MORNING.
SYNOPTIC INGREDIENTS STILL IN PLACE FOR CYCLOGENESIS ALONG THIS
COLD FRONT OFF THE MID ATLANTIC COAST LATER TODAY. THIS SECONDARY
LOW PRESSURE WILL MOVE NORTH ALONG THE FRONTAL BOUNDARY...AND SLOW
ITS EASTWARD PROGRESS. THIS WAVE WILL APPROACH THE BENCHMARK VERY
LATE TODAY. THE INCREASED SURFACE CONVERGENCE SHOULD BE ENOUGH TO
GENERATE A MORE WIDESPREAD RAINFALL TOWARD SOUTHEAST MA LATER
TODAY. EXPECTING A VERY SHARP WESTERN CUTOFF TO THE RAINFALL
SHIELD. NOT VERY CONFIDENT WHERE THAT WILL ESTABLISH RIGHT NOW. SO
WILL EXTEND A CHANCE OF RAINFALL WEST INTO NORTHEAST CT AND
CENTRAL MA. THIS MAY HAVE TO BE REFINED WITH LATER FORECASTS.
SEASONABLE TEMPERATURES ANTICIPATED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
TONIGHT...
AN OFFSHORE LOW PRESSURE WILL MAKE ITS CLOSEST APPROACH TO
SOUTHERN NEW ENGLAND TONIGHT. ONE LAST BURST OF MODERATE RAIN IS
EXPECTED UNTIL THIS LOW PRESSURE MOVES BY. FINAL STORM TOTALS
COULD REACH 1.0-1.5 INCHES ACROSS CAPE/ISLANDS...BUT AS MENTIONED
ABOVE...THERE IS LIKELY TO BE A VERY TIGHT QPF GRADIENT. WILL BE A
RACE BETWEEN THE DRYING AND COLD ADVECTION AS TO WHETHER A BRIEF
PERIOD OF FROZEN PRECIP IS OBSERVED BEFORE IT FINALLY COMES TO AN
END...BUT AT THIS TIME SOUNDINGS SUGGEST THE DRYING WILL WIN...SO
MAINTAIN ONLY LIQUID PRECIP.
TEMPERATURES SHOULD FALL QUICKLY OVER THE THE INTERIOR WITH
CLEARING SKIES. TIGHTER TEMPERATURE GRADIENT TOWARDS THE COAST.
MONDAY...
CLOUDS AND RAIN SHOULD BE EXITING THE OUTER CAPE EARLY MONDAY.
OTHERWISE DRIER AND BLUSTERY WEATHER FOLLOWS. HIGH PRESSURE WELL
TO OUR SOUTH WILL RESULT IN PERSISTENT NORTHWEST WINDS AND MODEST
COLD AIR ADVECTION. EXPECTING TEMPERATURES ABOUT 10 DEGREES LOWER
THAN SUNDAY...DESPITE PLENTY OF SUNSHINE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
HIGHLIGHTS...
* SEASONABLY COOL OR BELOW NORMAL TEMPS TUE
* DRY WEATHER WITH A MODERATING TEMPERATURE TREND THROUGH THE END OF
THE WEEK
* A COLD FRONT MOVES THROUGH SATURDAY PROVIDING A CHANCE OF PRECIP
MONDAY NIGHT THROUGH TUESDAY...EXCELLENT AGREEMENT AMONGST THE
MODELS WITH HIGH PRESSURE BUILDING OVER SOUTHERN NEW ENGLAND.
TEMPERATURES WILL BE BELOW NORMAL DURING THIS TIME FRAME...BUT DRY
WEATHER IS EXPECTED.
WEDNESDAY THROUGH FRIDAY...THERE IS VERY GOOD AGREEMENT AMONGST THE
MODELS ON THIS TIME PERIOD. DRY WEATHER IS EXPECTED AS HIGH
PRESSURE MOVES SLOWLY INTO THE MARITIMES WEDNESDAY. TEMPERATURES
WILL MODERATE THROUGH THE REMAINDER OF THE WEEK WITH TEMPERATURES
WELL ABOVE NORMAL ON THANKSGIVING AND FRIDAY.
SATURDAY...AN UPPER LEVEL TROUGH MOVES OVER SOUTHERN NEW ENGLAND. AT
THE SAME TIME...LOW PRESSURE MOVES FROM QUEBEC INTO THE
MARITIMES...BRINGING A COLD FRONT THROUGH THE REGION. THIS WILL
PROVIDE A CHANCE FOR PRECIPITATION ACROSS THE AREA. AT THIS
POINT...TEMPERATURES ARE SUCH THAT THIS WILL LIKELY BE RAIN. PRIOR
TO THE FRONT COMING THROUGH...WE WILL SEE CONTINUED WARMER THAN
NORMAL TEMPERATURES FROM THANKSGIVING AND FRIDAY.
&&
.AVIATION /17Z SUNDAY THROUGH THURSDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY/...
THROUGH 00Z...HIGH CONFIDENCE.
TRENDING TOWARD VFR ALL TERMINALS NW OF A LINE FROM HVN-BVY. S AND
E OF THIS LINE EXPECT MAINLY MVFR CIGS/VSBYS WITH A RAIN SHIELD
MOVING N ACROSS THE REGION. IFR CONFINED TO MAINLY CAPE/ISLANDS.
WINDS SHIFT TO THE NW...AT OR AROUND 10 KT.
00Z THIS EVENING THROUGH 12Z TOMORROW...MODERATE CONFIDENCE MAINLY
DUE TO TIMING UNCERTAINTY.
EXPECT GRADUAL TRANSITION FROM MIX OF MVFR/IFR TO VFR AT ALL E
MA/RI TERMINALS ESPECIALLY BEGINNING MAINLY AFTER 03Z. RAIN WILL
ALSO SLOWLY COME TO AN END THROUGH THIS PERIOD...ALTHOUGH WET
RUNWAYS ARE LIKELY EARLY. VERY LOW CONFIDENCE IN A BRIEF PERIOD
OF MIXED SLEET/SNOW MAINLY FOR E MA BEFORE THE PRECIP ENDS BETWEEN
03Z-06Z. WIND GUSTS TO AROUND 25KT AT THE COASTAL TERMINALS.
TOMORROW...HIGH CONFIDENCE.
MAINLY VFR. GUSTY NW WINDS TO 25 KT AT TIMES.
KBOS TAF...MODERATE CONFIDENCE IN TRENDS THROUGH 03Z...HIGHER
CONFIDENCE AFTER. ISSUE IS WHETHER BRIEF LIFTING OF MVFR CIGS
POSSIBLE LATER THIS AFTERNOON/EVENING.
KBDL TAF...HIGH CONFIDENCE IN TRENDS.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...
HIGH CONFIDENCE. VFR/DRY WEATHER AND GOOD VSBY.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
SHORT TERM /THROUGH MONDAY/...HIGH CONFIDENCE.
A BRIEF LULL IN SMALL CRAFT ADVISORY CONDITIONS ACROSS MOST WATERS
THIS MORNING. INCREASING SOUTHERLY SWELL WILL REACH NEAR 5 FT
AGAIN BY THIS EVENING. AS A COLD FRONT MOVES OFFSHORE...NW WINDS
ALSO INCREASE 25-30 KT TONIGHT. THE ONLY CAVEAT REMAINS BOSTON
HARBOR DUE TO UNCERTAINTY IN WIND STRENGTH AND ITS DURATION.
MONDAY...GUSTY NNW WINDS 20 TO 30 KT...STRONGEST WIND ACROSS THE
EASTERN MA WATERS. ROUGH SEAS EXPECTED. VSBY MAY LOWER EARLY IN
RAIN THEN IMPROVING QUICKLY.
OUTLOOK /MONDAY NIGHT THROUGH THURSDAY/...HIGH CONFIDENCE.
MONDAY NIGHT THROUGH THURSDAY...HIGH PRESSURE BUILDS INTO SOUTHERN
NEW ENGLAND AND THE COASTAL WATERS. NORTHWESTERLY WINDS DIMINISH
QUICKLY SWITCHING TO SOUTHEASTERLY TUESDAY NIGHT. SEAS SLOWLY
DIMINISH. SMALL CRAFT ADVISORIES WILL LIKELY STILL BE NEEDED FOR
MONDAY NIGHT AND POSSIBLY TUESDAY.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 1 PM EST MONDAY
FOR ANZ231>234.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 11 AM EST
MONDAY FOR ANZ236.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST MONDAY
FOR ANZ235-237-251.
SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ250-254-255.
SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ256.
&&
$$
SYNOPSIS...BELK/RLG
NEAR TERM...BELK/DOODY
SHORT TERM...BELK
LONG TERM...RLG
AVIATION...DOODY/RLG
MARINE...BELK/RLG
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1153 AM CST SUN NOV 22 2015
.UPDATE...
ISSUED AT 930 AM CST SUN NOV 22 2015
Short-wave trough embedded within broad northwesterly flow is
currently producing an area of mid-level clouds along/west of a
Chicago...to Peoria...to Columbia, Missouri line. These clouds
will spread eastward as the morning progresses. Have therefore
updated the sky grids to go with partly sunny wording across the
northern half of the KILX CWA. Have also adjusted hourly temps to
account for a faster diurnal temp rise across areas where little
or no snow is on the ground. Based on current temp trends and
expected arrival of mid-level cloud deck, have lowered afternoon
high temps by a degree or two along/north of I-74 where ample snow
cover exists. Highs will range from the upper 20s north of the
Peoria area...to the upper 30s around Jacksonville. Zone update
has already been issued.
&&
.SHORT TERM...(Today)
ISSUED AT 330 AM CST SUN NOV 22 2015
A very chilly start is on tap today due to the new snowfall.
Traditional cold spots from Altona to Lacon will see below zero
temps around sunrise. A 1028mb surface high pressure center will
pass just southwest of IL this morning. The ridge axis will progress
east of IL by 18z/Noon, allowing for surface winds to become
southerly this afternoon. Typically that means slightly warmer high
temps, but the new snow cover will keep temps a tick below potential
due to insolation going into melting the snow instead of sensible
heating. A band of altocumulus clouds is projected to move across
our northern counties today as well, with moisture mainly in the 850-
700mb layer per RAP and HRRR soundings. So a combination of snow pack
and cloud cover will limit highs north of I-74 to at or just below
freezing today. Southern areas with snow less than an inch should
see the sun help to melt off what feel on Saturday. High temps south
and southwest of Lincoln to Mattoon should reach the mid to upper
30s under sunny skies.
.LONG TERM...(Tonight through Saturday)
ISSUED AT 330 AM CST SUN NOV 22 2015
Surface high pressure ridge from eastern Texas into the Ohio river
valley at sunset will shift se into the Gulf Coast States Monday.
Meanwhile upper level trof over the OH/TN river valleys at sunset to
track east to the Atlantic Coast Monday morning, while another short
wave track northeast of central IL tonight into early Monday
morning. This feature may produce some mid level clouds over mainly
ne areas tonight and diminish by Monday morning. SSW winds 8-15 mph
to starts to modify temperatures. Lows tonight in the mid to upper
20s with some lower 20s over far northern CWA (Knox, Stark &
Marshall counties) where deeper snow pack of 6-10 inches is. Highs
Monday range from upper 30s to near 40F over northern CWA where snow
pack lingering while upper 40s SW CWA and into southeast IL.
Upper level ridge into IL Tue and into the eastern states Wed to
continue fair weather with temperatures continuing to modify. Lows
Monday night in the mid to upper 20s again with SW CWA near 30F. May
need to watch for patchy fog possibly developing over snow pack of
northern CWA later Monday night into early Tue morning as wind gets
lighter and have snow melt on Monday. Highs Tue range from lower 40s
from I-74 north to lower 50s sw CWA. Highs Wed around 50F northern
CWA and mid 50s sw CWA. Have slight chances of showers over the IL
river valley west of I-55 by Wed afternoon. Even milder highs Thu in
the upper 50s to around 60F.
Strong cutoff upper level low/trof digs over the Rockies during Wed
and Thu while surface low pressure to eject ne from the Texas
panhandle into the western great lakes Thu night and brings a cold
front east across IL in the Thu night to Fri time frame. 00Z models
still differ on timing of this front but generally show increasing
chances of showers from nw to se during Wed night and Thu with
likely pops Thu night into Friday. Rainfall amounts of 1-1.50 inches
during that time. Then cooler and drier weather follow late this
week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
ISSUED AT 1153 AM CST SUN NOV 22 2015
VFR conditions will prevail through the entire 18z TAF period. A
weak disturbance will spread mid-level clouds across the area this
afternoon. 1730z satellite imagery shows the clouds with bases of
7000-9000ft along/west of the Illinois River. Satellite timing
tools and Rapid Refresh RH progs suggest they will arrive at KPIA
by 18z, then further east to KCMI by around 21z. The clouds will
clear from west to east late this afternoon into the evening, but
additional mid-level clouds further upstream across western Iowa
will arrive by mid to late evening. Winds will initially be from
the south at around 10kt this afternoon, then will veer to the
W/SW by Monday morning.
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Barnes
SHORT TERM...Shimon
LONG TERM...07
AVIATION...Barnes
AREA FORECAST DISCUSSION
NWS GRAY ME
1236 PM EST SUN NOV 22 2015
.SYNOPSIS...
A COLD FRONT WILL PUSH THROUGH THE REGION ON TODAY AND A WEAK WAVE
OF LOW PRESSURE WILL MOVE NORTHEASTWARD ALONG THE FRONT DURING
THE DAY ALLOWING FOR SOME COASTAL RAIN LATER TODAY AND TONIGHT.
HIGH PRESSURE WILL BEGIN TO BUILD INTO THE REGION MONDAY
MORNING WHILE LOW PRESSURE TRACKS TO OUR EAST. THE HIGH WILL
SHIFT OFFSHORE ON WEDNESDAY AND A BROAD UPPER LEVEL RIDGE BUILDS
OVER NEW ENGLAND. THIS WILL BRING ABOVE AVERAGE TEMPERATURES
THROUGH THE END OF THE WORK WEEK. HIGH PRESSURE WILL HOLD
OFFSHORE THROUGH FRIDAY AND THE NEXT CHANCE FOR RAIN WILL COME ON
SATURDAY AS A COLD FRONT ENTERS THE AREA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1230 PM UPDATE...HAVE UPDATED THE FORECAST TO ACCOUNT FOR TRENDS
IN LATEST OBSERVATIONAL AND MESOSCALE MODEL DATA. MAIN FORECAST
CHALLENGE FOR THIS AFTERNOON IS THE QPF/POP GRADIENT FOR TONIGHT
AND IF COLDER AIR CAN ARRIVE IN TIME FOR RAIN TO CHANGE OVER THE
ACCUMULATING SNOW IN SPOTS.
9 AM UPDATE...HAVE ISSUED A SPECIAL WEATHER STATEMENT FOR
LOCALIZED FREEZING DRIZZLE IN SPOTS THROUGH ABOUT 1030 AM. MOST
LOCATIONS ARE AT OR ABOVE FREEZING...BUT A FEW MESONET OBS ARE
BETWEEN 30 AND 32 DEGREES AS OF 9 AM. SOME VERY LIGHT DRIZZLE IS
FALLING IN SPOTS. EVEN THOUGH ROADS SHOULD BE FAIRLY WARM...A FEW
SLICK SPOTS WILL BE POSSIBLE THROUGH ABOUT 1030 AM.
PREVIOUSLY...
LATEST HRRR CONTINUE TO BRING SOME LIGHT STEADY PRECIP TO THE
IMMEDIATE COAST DURING THE MID AFTERNOON HOURS. SOME SNOW MAY
POSSIBLY MIX IN WITH THE PRECIP LATER TONIGHT AS BOUNDARY LAYER
TEMPERATURES COOL WITH TIME.
PREV DISC...
A WEAK SYSTEM WILL MOVE NORTHEAST AND INTO CANADA
THIS MORNING...DRAGGING A COLD FRONT THROUGH THE REGION. A FEW
SCATTERED RAIN SHOWERS WILL CROSS THE REGION THIS
MORNING...HOWEVER MOST AREAS WILL REMAIN DRY. SOME OF THE RAIN
SHOWERS WILL MIX WITH A FEW SNOW SHOWERS ACROSS THE HIGHER
TERRAIN...MAINLY IN NEW HAMPSHIRE AND THE WESTERN MOUNTAINS OF
MAINE. MOST OTHER AREAS WILL REMAIN MILD WITH DAYTIME TEMPERATURES
REACHING THE 40S.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THE LATEST HRRR MODEL RUN CONTINUES TO SHOW PRECIPITATION BREAKING
OUT LATE THIS AFTERNOON AND THIS EVENING IN THE FORM OF SOME LIGHT
RAIN...MAINLY ALONG THE COASTLINE. THIS WILL BE TRIGGERED FROM
CYCLOGENESIS OFF THE MID ATLANTIC COASTLINE DURING THE DAY.
00Z GUIDANCE SUGGESTS THE MAJORITY OF THE PRECIPITATION WILL
REMAIN TO OUR EAST TONIGHT. HOWEVER...THERE HAS BEEN A TREND TO
SPILL THE RAINFALL BACK INTO OUR FORECAST AREA FROM RUN TO RUN AND
THIS TREND CONTINUES. HIGHEST RAINFALL AMOUNTS WILL BE A THIRD TO
A HALF INCH ALONG THE MIDCOAST REGION OF MAINE.
PTYPE...THERE WILL ALSO BE SOME AREAS ALONG THE MIDCOAST AND
INLAND NORTH AND EAST OF THE AUGUSTA AND WATERVILLE CORRIDOR THAT
HAS A TRANSITION TO SNOW LATE TONIGHT AND EARLY MONDAY. THIS AREA
WILL SEE COLD AIR ADVECTED INTO THE REGION WITH THE PASSAGE OF AN
H8 LOW AND THE APPROACH OF THE UPPER LEVEL TROUGH EARLY MONDAY.
THE SNOW WILL MAINLY STICK ACROSS ANY ELEVATED TERRAIN...AND AT
THIS TIME WE ARE EXPECTING A COATING TO AN INCH OF SNOW. A FEW
COMMUNITIES MAY PICK UP A COUPLE INCHES OF ACCUMULATION.
HAZARDS: SOME SLICK DRIVING MONDAY MORNING EASTERN SECTIONS.
GUSTY NORTHERLY WINDS AS WELL HOWEVER...NOT OVERLY WINDY WITH
GUSTS TO ABOUT 25 MPH. THERE MAY BE A SHARP GRADIENT TO THE
PRECIPITATION FROM WEST TO EAST NEAR THE PENOBSCOT RIVER VALLEY.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
- COLD START TO THE FORECAST WITH TEMPS SLIGHTLY BELOW NORMAL
- WARMUP STARTS WED WITH HIGHS REACHING MID TO UPPER 50S BY FRI
- COLD FRONT WILL BRING CHANCE OF RAIN AND COOLER TEMPS NEXT
WEEKEND
OPERATIONAL MODEL GUIDANCE AND GFS/EURO ENSEMBLES ARE ACTUALLY
IN GOOD AGREEMENT THROUGH THE LONG TERM. WE START THE PERIOD
ON TUESDAY WITH AN ANOMALOUS 500MB TROUGH OVER NEW ENGLAND WITH
H500 ABOUT 1 TO 2 STANDARD DEVIATIONS BELOW NORMAL. THE SAME IS
ALSO TRUE FOR T850. DUE TO THIS I DECIDED TO DROP LOW
TEMPERATURES A BIT BELOW THE MODEL CONSENSUS FOR TUESDAY MORNING.
THE GOOD NEWS IS THAT THE SLIGHTLY BELOW AVERAGE TEMPERATURES
WILL BE SHORT LIVED AND THE TROUGH IS QUICKLY REPLACED BY A BROAD
UPPER LEVEL RIDGE AND STRONG WARM AIR ADVECTION ALOFT. H500
TOWARDS THE END OF THE WORKWEEK ARE 2 - 3 STANDARD DEVIATIONS
ABOVE NORMAL AND T850 OF 1 - 2 STANDARD DEVIATIONS ABOVE. THIS
WILL LIKELY MEAN THAT WE SEE TEMPERATURES WELL ABOVE AVERAGE ON
THANKSGIVING DAY AND FRIDAY...WITH HIGHS CLIMBING INTO THE 50S
ACROSS SOUTHERN LOCATIONS.
THEREAFTER...COLD FRONTAL PASSAGE LOOKS LIKELY ON SATURDAY
AND SHOULD SPREAD SOME SHOWERS ACROSS THE AREA. DECIDED TO GO
WITH A GUIDANCE CONSENSUS BLEND FOR POP ON SATURDAY DUE TO SOME
MINOR VARIATIONS OF TIMING BETWEEN THE MODELS AT THIS TIME.
BEHIND THIS FRONT...STRONG COLD AIR ADVECTION WILL BRING A SHARP
CONTRAST TO TEMPERATURES COME SUNDAY...WITH FORECASTED HIGHS
SLIGHTLY BELOW AVERAGE.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...AREAS OF IFR AND MVFR CONDITIONS THIS MORNING WITH
SOME LOW CLOUDS CROSSING THE REGION. CEILINGS WILL LIFT THIS
AFTERNOON. CLOUDS WILL LOWER AND THICKEN WITH RAIN ALONG THE COAST
TONIGHT INTO EARLY MONDAY...WITH SOME SNOW MIXING IN NEAR THE
CAPITAL DISTRICT.
LONG TERM...HIGH PRESSURE OVERHEAD SHOULD PROVIDE VFR CONDITIONS
THROUGHOUT THE FORECAST PERIOD.
&&
.MARINE...
SHORT TERM...SMALL CRAFT ADVISORIES HAVE BEEN HOISTED FOR TONIGHT
INTO EARLY MONDAY. A NORTHERLY FLOW WILL INCREASE OVER THE WATERS.
STRONGEST GRADIENT WILL REMAIN EAST OF OUR AREA WHERE GALE WATCHES
REMAIN IN EFFECT. GUSTY WINDS AND CHOPPY SEAS WILL CONTINUE
THROUGHOUT THE DAY ON MONDAY.
LONG TERM...WILL LIKELY SEE SCA CONDITIONS CONTINUE INTO
TUESDAY MORNING AND EVEN THOUGH WINDS WILL DROP BELOW 25 KNOTS
LATER MONDAY NIGHT....SEAS WILL LIKELY STAY IN THE 5 TO 7FT RANGE
INTO TUESDAY MORNING. HIGH PRESSURE AND WEAK A GRADIENT SHOULD
PERSIST AFTER THAT AND NO OTHER FLAGS ARE EXPECTED AT THIS TIME.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 8 PM THIS EVENING TO 6 PM EST MONDAY
FOR ANZ150>154.
&&
$$
NEAR TERM UPDATE...EKSTER
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1235 PM CST SUN NOV 22 2015
.SYNOPSIS...
ISSUED AT 339 AM CST SUN NOV 22 2015
THE 08Z MSL ANALYSIS SHOWED LOW PRESSURE CENTERED OVER NORTHWEST
SASKATCHEWAN WITH A WARM FRONT DRAPED THROUGH THE DAKOTAS. ANOTHER
WEAKER FRONT WAS INDICATED FROM SOUTHEAST WYOMING THROUGH EASTERN
COLORADO TO THE TEXAS-OKLAHOMA PANHANDLES. IN THE UPPER LEVELS...THE
WATER VAPOR IMAGERY SHOWED THE JET FROM SOUTHWEST OREGON THROUGH THE
FOUR CORNERS REGION ACROSS NORTH TEXAS AND CENTRAL ARKANSAS. A
DEVELOPING CYCLONE COULD BE SEEN OVER THE NORTHEAST PACIFIC NEAR
41.5N/133.6W.
&&
.UPDATE...
ISSUED AT 1235 PM CST SUN NOV 22 2015
UPDATED THE FORECAST TO ACCOUNT FOR A BIT MORE WARMING THAN
PREVIOUSLY THOUGHT...EVEN IN SNOW COVERED AREAS. WEST WINDS ARE
ALSO A BIT STRONGER WHICH THE RAP MODEL WAS BETTER AT IDENTIFYING
DUE TO BETTER MIXING THROUGH THE AFTERNOON. OTHERWISE REST OF FCST
REMAINS AS IT WAS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 339 AM CST SUN NOV 22 2015
SOUTHWEST FLOW DEVELOPS IN WESTERN NEBRASKA THIS AFTERNOON.
THAT...COMBINED WITH ABUNDANT SUNSHINE...WILL GIVE SIGNIFICANT
WARMING TO MOST OF NEBRASKA. IN NORTH CENTRAL NEBRASKA...WHERE SNOW
COVER IS PRESENT...TEMPERATURES WILL BE COLDER THOUGH 5-10 DEGREES
WARMER THAN THEY WERE YESTERDAY. LIGHT WIND AND CLEAR SKY WILL FAVOR
TEMPERATURES TONIGHT FALLING TO THE MID TEENS TO MID 20S.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 339 AM CST SUN NOV 22 2015
A MILD AND DRY START TO THE WEEK IS EXPECTED AHEAD OF A LARGE UPPER
LEVEL LOW PRESSURE SYSTEM THAT WILL BE DIGGING SOUTHEAST INTO THE
WESTERN PORTION OF THE UNITED STATES. VERY MILD AIR WILL BE IN PLACE
AHEAD OF THIS SYSTEM...WITH H850MB TEMPS SUPPORTING HIGHS IN THE MID
40S TO MID 50S BOTH MONDAY AND TUESDAY.
ALL EYES WILL FOCUS ON THE WESTERN CONUS UPPER LEVEL LOW AS THE
THANKSGIVING HOLIDAY DRAWS NEARER. THE GEFS ENSEMBLES AND THE
OPERATIONAL GFS AND ECMWF CONTINUE TO SHEAR THE UPPER LEVEL TROUGH
OUT THANKSGIVING DAY INTO FRIDAY. THIS SCENARIO WOULD NOT FAVOR
HEAVY OR SIGNIFICANT PRECIPITATION FOR OUR AREA...AS SOUTHWEST FLOW
ALOFT WOULD FAVOR DRY SLOTTING. A NEW DEVELOPMENT TONIGHT IS UPPER
LEVEL ENERGY BEING HELD BACK WITH A NEW UPPER LOW REFORMING THEN
HEADING TOWARD THE CENTRAL PLAINS SUNDAY INTO MONDAY. THIS IS JUST
BEYOND THE FORECAST PERIOD AND WILL CONTINUE TO MONITOR.
TEMPERATURE WISE...THE MILD START TO THE WEEK WILL COME TO AN ABRUPT
END AS A STRONG ARCTIC COLD FRONT PLUNGES SOUTH THOUGH THE AREA LATE
WEDNESDAY NIGHT AND THANKSGIVING DAY. HIGHS ONLY IN THE 20S CAN BE
EXPECTED FRIDAY IN THE WAKE OF THE FRONT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1132 AM CST SUN NOV 22 2015
VFR CONDITIONS WILL PREVAIL THROUGH THE FCST PERIOD.
WEAK SFC FRONT WILL SAG ACROSS THE CENTRAL PLAINS THIS EVENING AND
OVERNIGHT BUT WILL NOT MAKE AS MUCH PROGRESS SWD AS HEIGHTS BEGIN
TO FALL A LITTLE ACROSS THE WEST LEADING TO A LESS AMPLIFIED FLOW
ACROSS THE PLAINS. SOME HIGH CLOUDS WILL BE PRODUCED AS A
RESULT...BUT THAT IS IT WITH DRY LOWER LEVELS IN PLACE. SFC
PRESSURE FALLS DEVELOP AS THIS ZONAL FLOW DEVELOPS AND A WEAKENING
OF THE WESTERLIES BY MONDAY MORNING. THE WEAKENING FRONT WILL
QUICKLY RETREAT NWD THROUGH THE NIGHT AS THIS OCCURS...AND A
RETURN TO MOSTLY CLEAR SKIES.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...STOPPKOTTE
SYNOPSIS...SPRINGER
SHORT TERM...SPRINGER
LONG TERM...TAYLOR
AVIATION...STOPPKOTTE