Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/11/15
AREA FORECAST DISCUSSION...UPDATED
NWS RENO NV
757 PM PST THU DEC 10 2015
.UPDATE...
BAND OF MODERATE TO HEAVY SNOW IS MOVING THROUGH THE TAHOE BASIN
AND INTO THE SIERRA FRONT NORTH OF HIGHWAY 50. SNOWFALL RATES OF
2-3 INCHES PER HOUR ARE OCCURRING IN THIS BAND WITH 1-2 INCHES
ALREADY REPORTED ACROSS RENO. WE RECORDED 1-1.5 INCHES IN THE
LAST 30 MINUTES HERE AT THE OFFICE. WITH ANOTHER COUPLE MODERATE
TO HEAVY BANDS EXPECTED TO FORM BASED ON THE LATEST HRRR GUIDANCE
AND UPSTREAM CONVECTION, ISSUING A WINTER WEATHER ADVISORY FOR THE
RENO, CARSON, MINDEN AREAS THROUGH 10 AM FRIDAY. WHILE THE SNOW
WILL LIKELY END BETWEEN 4-7 AM, THE ROADS WILL LIKELY REMAIN SLICK
THROUGH THE MORNING COMMUTE.
OTHERWISE, THE WARNINGS FOR THE SIERRA LOOK GOOD, BUT SOME LOCALLY
HIGHER AMOUNTS THAN WHAT WE HAVE FORECAST ARE POSSIBLE. IT WOULD
NOT SURPRISE ME TO SEE NEAR 2 FEET FALL NEAR THE SIERRA CREST IN
PLACES FROM PERSISTENT BANDS GIVEN THE INTENSITY. WALLMANN
&&
.SYNOPSIS...
A WINTER STORM IS MOVING THROUGH THE REGION. SNOW LEVELS HAVE
REACHED SIERRA VALLEY FLOORS AND WILL CONTINUE TO LOWER OVERNIGHT
TOWARDS WESTERN NEVADA VALLEY FLOORS. SNOW MAY ACCUMULATE IN LOWER
VALLEYS BY EARLY FRIDAY MORNING. ANOTHER COLDER STORM WILL LIKELY
BRING MORE SNOW AND WIND FOR SUNDAY AND SUNDAY NIGHT. BOTH OF THESE
STORMS WILL PRODUCE SIGNIFICANT TRAVEL IMPACTS ESPECIALLY NEAR THE
SIERRA.
&&
.PREVIOUS DISCUSSION... /ISSUED 235 PM PST THU DEC 10 2015/
SYNOPSIS...
A WINTER STORM IS MOVING THROUGH THE REGION. SNOW LEVELS HAVE
REACHED SIERRA VALLEY FLOORS AND WILL CONTINUE TO LOWER OVERNIGHT
TOWARDS WESTERN NEVADA VALLEY FLOORS. SNOW MAY ACCUMULATE IN
LOWER VALLEYS BY EARLY FRIDAY MORNING. ANOTHER COLDER STORM WILL
LIKELY BRING MORE SNOW AND WIND FOR SUNDAY AND SUNDAY NIGHT. BOTH
OF THESE STORMS WILL PRODUCE SIGNIFICANT TRAVEL IMPACTS ESPECIALLY
NEAR THE SIERRA.
SHORT TERM...
THE WINTER STORM CONTINUES TO PRODUCE SNOW SHOWERS MAINLY IN THE
SIERRA THIS AFTERNOON. THESE SHOWERS HAVE BEEN INCREASINGLY
SCATTERED THIS AFTERNOON AS WE PROGRESS THROUGH THE LULL PERIOD
BETWEEN WAVES. EXPECT COVERAGE TO INCREASE ONCE AGAIN LATE THIS
AFTERNOON AND EVENING AS THE SECOND, COLDER WAVE MOVES INTO THE
SIERRA. THIS WAVE IS PROVING TO BE QUITE VIGOROUS. AS SUCH, THERE
WILL BE A 10% CHANCE OF THUNDERSTORMS ALONG THE CREST INTO THE
WESTERN PORTION OF THE TAHOE BASIN NORTHWARD THROUGH WESTERN
LASSEN COUNTY. SNOW LEVELS HAVE BEEN VERY SLOW TO LOWER, BUT HAVE
REACHED SIERRA VALLEY FLOORS THIS AFTERNOON. EXPECT THEM TO
CONTINUE TO LOWER THIS EVENING AND OVERNIGHT TO WESTERN NEVADA
VALLEY FLOORS.
CONVECTIVE BANDING WILL BE AN ISSUE AS WE HAVE SEEN THIS
AFTERNOON. SOME BANDS HAVE BEEN PERSISTENT ESPECIALLY ALONG THE
INTERSTATE 80 CORRIDOR AND JUST SOUTH OF TAHOE. EXPECT
INTERMITTENT BANDING TO PRODUCE HEAVY SNOW RATES AT TIMES AS THEY
FORM, PERSIST, THEN DISSIPATE. THESE BANDS WILL PRODUCE LOCALLY
HIGHER SNOW TOTALS AND COULD BE AN ISSUE AS WE HEAD INTO THIS
EVENING WHEN SYNOPTIC FORCING EXPANDS AREAL COVERAGE OF SNOW AND
SNOW SHOWERS. ADDITIONAL ACCUMULATIONS WILL RANGE WITH HIGHEST
TOTALS NEAR THE SIERRA CREST. GENERALLY EXPECTING 6-18 INCHES AT
THE CREST AND 4 TO 8 INCHES BELOW 7000 FEET WITH HIGHER TOTALS OF
6-12 INCHES WEST OF HIGHWAY 89.
HAVE REDUCED TOTAL QPF FOR THE NEXT WAVE ALONG THE SIERRA FRONT
AND WESTERN NEVADA WHICH LOOKS TO BE INCREASINGLY SHADOWED. STILL,
2-3 INCHES COULD FALL IN THE FOOTHILLS WILL LOCALLY HIGHER TOTALS
IN AREAS WHERE CONVECTIVE BANDING FORMS. AS FOR RENO/CARSON CITY
METRO AREAS, MAINLY LESS THAN AN INCH. THESE TOTALS ARE FOR
SYNOPTIC FORCING AND DO NOT TAKE INTO ACCOUNT ANY CONVECTIVE
ACTIVITY. A CONVECTIVE BAND CANNOT BE RULED OUT FOR THE METRO
AREAS, BUT FORECASTER CONFIDENCE IN PREDICTIVE PLACEMENT IS
MINIMAL. ANY AREAS WHERE CONVECTIVE BANDS SET UP, COULD GET AN
ADDITION INCH OR TWO OF SNOW DEPENDING ON DURATION.
LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...
A FEW MINOR CHANGES WERE MADE TO THE FORECAST FOR THIS WEEKEND
REGARDING THE NEXT ROUND OF MOUNTAIN SNOW AND VALLEY RAIN. THESE
CHANGES MAINLY REVOLVE AROUND A PERIOD OF WARM AIR ADVECTION
PRECIPITATION SATURDAY AND SATURDAY EVENING NORTH OF A SUSANVILLE TO
GERLACH LINE...AND THE WINDS AHEAD OF THE MAIN UPPER TROUGH SUNDAY.
THE SATURDAY NIGHT PORTION OF THE WARM AIR ADVECTION SYSTEM IS
SHOWING BETTER SIGNS OF ORGANIZING AND CONFIDENCE HAS INCREASED
ENOUGH TO RAISE POPS FOR SATURDAY EVENING AND OVERNIGHT OVER THE
NORTHERN THIRD OF THE FORECAST AREA. CONFIDENCE IS LOWER REGARDING
THE AMOUNT OF PRECIPITATION EXPECTED. AS THIS IS AN OVER RUNNING
EVENT, TOTALS COULD REMAIN ON THE LOW SIDE...BUT WE HAVE TRENDED
UP A LITTLE WITH THE TOTALS FOR SATURDAY EVENING. ISENTROPIC LIFT
IS NOT OVERWHELMING SATURDAY NIGHT, BUT THE PRESSURE CONDENSATION
DEFICIT IS SO LOW THAT VERY LITTLE LIFT WILL BE NEEDED TO PRODUCE
LIGHT PRECIPITATION. FORECAST SOUNDINGS FOR CEDARVILLE SHOW A
SATURATED AIRMASS WITH TEMPS ALL BELOW FREEZING. THIS WOULD
INDICATE ALL SNOW SATURDAY EVENING. QPF VARIATIONS IN THE MODELS
CAST SOME DOUBT ON SNOW AMOUNTS...BUT FOR NOW WE WILL MENTION
AROUND 4 INCHES. IT IS HIGHLY LIKELY WE WILL ISSUE EITHER AN
ADVISORY OR WARNING FOR SURPRISE VALLEY FOR THIS SYSTEM...BUT FOR
NOW WE WILL HOLD OFF TO SEE IF MODEL QPF COMES MORE IN ALIGNMENT.
FARTHER SOUTH THE MAIN UPPER LOW MOVES INTO THE SIERRA EARLY SUNDAY.
AHEAD OF THIS LOW A STRONG PRESSURE/THERMAL GRADIENT AND STRONG
WINDS ALOFT WILL INDUCE GUSTY WINDS. WHILE MID LEVEL WINDS ARE NOT
AS STRONG WITH THIS SYSTEM AS THE ONE EXITING NOW...WE COULD EASILY
SEE GUSTS IN THE 45-55 MPH RANGE FOR MUCH OF THE FORECAST AREA. AS
WE STILL HAVE AN ONGOING SYSTEM, WE WILL HOLD OFF ISSUING ANY
ADVISORIES AT THIS TIME...BUT BE AWARE THEY WILL LIKELY BE ISSUED AS
EARLY AS FRIDAY MORNING.
THE UPPER LOW HAS A VIGOROUS ASSOCIATED COLD FRONT. THIS SYSTEM HAS
INCREASED IN FORWARD MOTION OVER THE LAST COUPLE OF MODEL RUNS. THIS
MAY LIMIT THE AMOUNT OF LIQUID PRECIPITATION...BUT TEMPS AHEAD OF
THE SYSTEM WILL NOT BE AS WARM AS THE PREVIOUS SYSTEM AT THE OUTSET
SO SNOW LEVELS WILL BE FASTER TO FALL. THE JET POSITION BY EARLY
SUNDAY AFTERNOON AND INCREASED INSTABILITY SHOULD ALLOW SPILL OVER
TO BECOME EFFICIENT DURING THE DAY SUNDAY. THE HEAVIEST BURST OF
PRECIPITATION SHOULD BE A SIX HOUR PERIOD SUNDAY AFTERNOON. THIS IS
THE TIME WHEN ACCUMULATIONS IN THE SIERRA COULD REACH NEAR WARNING
CRITERIA AND CREATE PROBLEMS FOR TRAVEL. ACCUMULATIONS EAST OF
THE SIERRA WILL BE LIMITED.
BY MONDAY MORNING THE SYSTEM IS PROGRESSING EAST WITH LINGERING
SHOWERS OVER THE REGION. THESE WILL DECREASE BY TUESDAY BUT
TEMPERATURES WILL REMAIN BELOW AVERAGE. THE MODELS NOW SHOW A RIDGE
DEVELOPING BY WEDNESDAY...BUT TEMPERATURES SLOW TO WARM AS
INVERSIONS DEVELOP. 20
AVIATION...
WIND:
THE STRONGEST WINDS HAVE WEAKENED AS PRECIPITATION MOVED INTO THE
SIERRA AND NORTHWEST NEVADA TODAY. WINDS ARE STILL LOCALLY GUSTING
UP TO 30 KTS IN A FEW VALLEY LOCATIONS WITH GUSTS IN THE 40 TO 70
KT RANGE ACROSS SIERRA RIDGES. THIS IS LEADING TO MULTIPLE
TURBULENCE REPORTS ACROSS THE REGION, THOUGH LLWS IS UNLIKELY
BASED ON CURRENT CONDITIONS. WINDS WILL BECOME LIGHTER OVERNIGHT,
BUT ANOTHER ROUND OF STRONG WINDS IS POSSIBLE SATURDAY NIGHT INTO
SUNDAY.
RAIN AND SNOW:
THE MAIN PRECIPITATION BAND FROM EARLIER THIS MORNING HAS
WEAKENED AND THERE ARE PRESENTLY SCATTERED SHOWERS ACROSS THE
SIERRA AND ISOLATED SHOWERS IN WESTERN NEVADA. ADDITIONAL
ACCUMULATION AT ANY TERMINALS THIS AFTERNOON WILL BE LIGHT.
THE NEXT WAVE FROM THIS SYSTEM ARRIVES TONIGHT WITH ACCUMULATING
SNOW LIKELY AT KTRK, KTVL, AND KMMH. TOTALS THROUGH FRIDAY MORNING
ARE EXPECTED TO BE IN THE 5 TO 10 INCH RANGE AROUND KTRK AND KTVL,
WITH 3 TO 6 INCHES AT KMMH. A LIGHT DUSTING, POSSIBLY UP TO AN INCH
OF SNOW IS POSSIBLE FOR KRNO AND KCXP. EXPECT WIDESPREAD IFR
CONDITIONS IN THE SIERRA AND PERIODS OF IFR CONDITIONS IN WESTERN
NEVADA ALONG WITH MOUNTAIN OBSCURATION. AIRCRAFT ICING IS ALSO
LIKELY OVERNIGHT INTO FRIDAY MORNING.
ANOTHER STORM IS ON TRACK FOR SATURDAY INTO SUNDAY, IMPACTING
AIRPORTS THROUGHOUT THE REGION. DJ
REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 4 AM PST FRIDAY NVZ002.
LAKE WIND ADVISORY UNTIL 6 PM PST THIS EVENING FOR PYRAMID LAKE
IN NVZ004.
CA...WINTER STORM WARNING UNTIL 4 AM PST FRIDAY CAZ071.
WINTER STORM WARNING UNTIL 7 AM PST FRIDAY CAZ073.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY CAZ072.
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...WINTER STORM WARNING UNTIL 4 AM PST FRIDAY NVZ002.
WINTER WEATHER ADVISORY UNTIL 10 AM PST FRIDAY NVZ003.
CA...WINTER STORM WARNING UNTIL 4 AM PST FRIDAY CAZ071.
WINTER STORM WARNING UNTIL 7 AM PST FRIDAY CAZ073.
WINTER STORM WARNING UNTIL 4 AM PST FRIDAY CAZ072.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
348 AM PST WED DEC 9 2015
...WIDESPREAD RAIN AND LOCALLY GUSTY CONDITIONS ON THURSDAY...
.SYNOPSIS....LOOK FOR RAIN TO MOVE TO THE NORTH BAY LATER TODAY
AND THEN ACROSS OUR ENTIRE REGION ON THURSDAY AS A FRONT MOVES
THROUGH. GUSTY WINDS WILL ACCOMPANY ITS APPROACH AND PASSAGE.
SHOWERS AND POSSIBLE THUNDERSTORMS ARE THEN EXPECTED THURSDAY
NIGHT INTO FRIDAY AS A COOL AND UNSTABLE AIR MASS MOVES IN. MORE
WIDESPREAD RAIN IS SLATED FOR LATE SATURDAY THROUGH SUNDAY.
&&
.DISCUSSION...AS OF 3:00 AM PST WEDNESDAY...HIGH CLOUDS STREAMING
ACROSS OUR AREA THIS MORNING HAS HELPED TO KEEP TEMPERATURES
WARMER COMPARED TO YESTERDAY WITH MANY SPOTS 5 TO 10 DEGREES
AHEAD. IN ADDITION, SOME LOCATIONS HAVE SEEN FOG WITH VISIBILITIES
DOWN TO LESS THAN 1/2 A MILE ALTHOUGH MOST OBSERVATIONS ARE NOW
REPORTING VISIBILITIES GREATER THAN 3 MILES.
RAIN WILL ADVANCE TO THE NORTH BAY LATER THIS MORNING AS THE WEAK
RIDGE OVER US YESTERDAY FLATTENS AND MOVES TO THE EAST. 500 MB
FLOW WILL BEGIN TO SAG TO THE SOUTH ALLOWING MOISTURE BACK TO OUR
AREA. KBHX RADAR IS PICKING UP ECHOS ABOUT TO ENTER THE MENDO
COUNTY COAST WITH HRRR SHOWING THE LEADING EDGE GETTING TO THE
SONOMA COAST BY MID-MORNING TODAY. RAIN WILL SLOWLY CONTINUE TO
SPREAD TO THE SOUTH WITH A LITTLE LIGHT RAIN POSSIBLE INTO THE SF
BAY REGION BY THE AFTERNOON.
THIS ROUND OF RAIN IS A PRECURSOR TO THE BIGGER EVENT AS A COLD
FRONT WITH MODERATELY MOIST AIR (PW VALUES OF UP TO 1.20")
ADVANCES FROM THE NORTHWEST LATE TONIGHT AND CONTINUES INTO
THURSDAY. WIDESPREAD RAINFALL WILL MOVE INTO THE NORTH BAY LATE
TONIGHT THEN DOWN TO SF BAY REGION AROUND THE MORNING RUSH. THE
FRONT WILL CONTINUE TO THE MONTEREY BAY REGION AROUND BY EARLY
AFTERNOON. DURING THE FRONTAL PASSAGE, RAIN COULD BE MODERATE TO
HEAVY AT TIMES ALTHOUGH THE DURATION SHOULD BE FAIRLY SHORT. AFTER
A BREAK IN THE PRECIPITATION, SHOWERS WILL MOVE IN FROM THE
NORTHWEST AS THE ATMOSPHERE BECOMES MUCH MORE UNSTABLE.
THUNDERSTORMS WITH SMALL HAIL WILL ALSO BE POSSIBLE ESPECIALLY BY
TOMORROW NIGHT AS THE MOST FAVORED DYNAMICS MOVE ACROSS OUR AREA.
SHOWERS LOOK LIKELY INTO FRIDAY AFTERNOON WITH DRY WEATHER EXPECTED
TO RETURN BY FRIDAY EVENING. MODELS ARE SUGGESTING THAT RAINFALL
FROM THE SHOWERS MAY END UP BEING GREATER THAN THE RAIN DURING THE
FRONTAL PASSAGE. RAINFALL TOTALS THROUGH FRIDAY MORNING ARE EXPECTED
TO BE 1-2" FOR THE NORTH BAY MOUNTAINS, UP TO AN INCH FOR COASTAL
RANGES OF SANTA CRUZ AND MONTEREY COUNTIES, AND 1/3" TO 2/3" FOR
MANY METRO AREAS. SNOW LEVELS WILL DROP DOWN TO UNDER 4000 FEET BY
FRIDAY MORNING WITH MINOR ACCUMULATIONS EXPECTED FOR OUR HIGHEST
PEAKS.
WIND WILL ALSO BE A FACTOR WITH INCREASING WEST TO SOUTHWEST WINDS
EXPECTED TONIGHT INTO THURSDAY. MODELS CONTINUE TO FOCUS THE
HIGHEST SPEEDS OVER THE NORTH BAY MOUNTAINS, SO WILL KEEP THE
ADVISORY GOING FOR THAT REGION. MOST LOCATIONS COULD SEE SPEEDS OF
15 TO 25 MPH WITH GUSTS TO 35 MPH.
SIMILAR TO TODAY, RAIN WILL GENERALLY BE CONFINED TO THE NORTH BAY
ON SATURDAY BEFORE SPREADING AGAIN ACROSS THE ENTIRE CWA AS
ANOTHER COLD FRONT MOVES THROUGH ON SUNDAY. ECMWF HAS BEEN
TRENDING WETTER WHICH IS MORE IN LINE WITH THE GFS SOLUTIONS OVER
THE PAST COUPLE OF DAYS. IN ADDITION, PW VALUES ARE NOW FORECAST
TO APPROACH 1.10" WHICH IS AN INCREASE OF AROUND .2" FROM
YESTERDAY. THEREFORE, RAINFALL AMOUNTS MAY HAVE THE POTENTIAL TO
REACH VALUES SIMILAR TO WHAT WE ARE EXPECTING THURSDAY INTO
FRIDAY. POPS WERE INCREASED FOR SATURDAY NIGHT THROUGH SUNDAY.
LONGER RANGE GUIDANCE FROM CPC ALSO FAVORS ABOVE NORMAL RAINFALL
FOR NEXT WEEK SUGGESTING A CONTINUED ACTIVE PATTERN.
&&
.AVIATION...AS OF 03:50 AM PST WEDNESDAY... LOW TO MEDIUM
CONFIDENCE FORECAST. HIGH CLOUDS SPILLING ACROSS CALIFORNIA THIS
MORNING ARE OBSCURING VIEW OF THE CRITICAL LOWER LEVEL CLOUDS. OBS
STATIONS PRIMARILY REPORTING VFR TO MVFR CIGS... WITH PATCHY VLIFR
IN SALINAS AND NORTH BAY VALLEYS. EXPECTING CIGS TO BOUNCE AROUND
THROUGH THE TAF PERIOD... WITH GRADUALLY DETERIORATING CIGS
AS SFC BOUNDARY APPROACHES AT THE END OF TAF PERIOD. CIGS LOOK TO
BE CONTAINED BETWEEN 1600-4000 FT AGL FOR THIS MORNINGS AVIATION
PUSHES THEN DROPPING TO 1000-2000 FT OR LOWER FOR TONIGHT/EARLY
THURSDAY. LIGHT PRECIP POSBL LATER TODAY IN NORTH BAY. WINDS
PREDOMINATELY LIGHT... THEN INCREASING TOWARDS END OF TAF PERIOD.
VICINITY OF KSFO...OSCILLATING VFR TO MVFR CIGS WITH CLOUDS
1600-4000 FT AGL. WINDS INCREASING STEADILY AFTER 00Z THU. WINDS
GUSTING TO 30-35KT 12-18Z THU.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...VFR EXCEPT WHERE THERE IS PATCHY FOG.
LIGHT WINDS. MVFR TO IFR CIGS POSBL AFTER 02Z THU.
&&
.MARINE...AS OF 3:00 AM PST WEDNESDAY...A STRONG STORM SYSTEM
WILL CAUSE WINDS TO INCREASE LATE WEDNESDAY INTO THURSDAY
PRODUCING HAZARDOUS CONDITIONS. A VERY LARGE LONG PERIOD SWELL
WILL ARRIVE THURSDAY AND FRIDAY PRODUCING HAZARDOUS CONDITIONS
NEAR THE IMMEDIATE COASTLINE...ESPECIALLY ALONG COASTAL REEFS AND
SAND BARS AS WELL AS ACROSS THE SAN FRANCISCO BAR.
&&
.BEACHES...AS OF 3:00 AM PST WEDNESDAY...ANOTHER LARGE SWELL WILL
IMPACT THE COASTAL WATERS LATE TONIGHT THROUGH FRIDAY. SOME OF THE
MODEL GUIDANCE SUGGESTS THIS COULD BE THE BIGGEST SWELL OF THE
SEASON THUS FAR. LATEST FORECAST WILL HAVE SWELLS OVER 20 FEET IN
THE OUTER WATERS AND 15 TO 20 FEET IN THE INNER WATERS. THE PERIOD
IS GREATER THAN 16 SECONDS. THAT BEING SAID...WAVES BREAKING AT
THE COAST COULD EASILY EXCEED 20 FEET AND OVER 30 FEET AT DEEP
WATER BREAKS.
THESE LARGE BREAKING WAVES WILL PUSH WATER WELL UP ONTO THE BEACH
POSSIBLY WASHING PEOPLE FROM THE BEACH INTO THE SEA. LARGE SNEAKER
WAVES WILL ALSO BE POSSIBLE ON STEEP BEACHES SUCH AS CARMEL RIVER
BEACH AND MONTARA BEACH. PLEASE DO NOT CLIMB ON ROCKS OR JETTIES
ALONG THE COAST SINCE THESE AREAS WILL ALSO BE PRONE TO SNEAKER
WAVES. THESE WAVES WILL ARRIVE IN SETS WITH LONG LULLS BETWEEN
WAVE ACTIVITY WHICH COULD GIVE BEACH VISITORS A FALSE SENSE OF
SECURITY...DRAWING THEM CLOSER TO THE WATERS EDGE. REMEMBER TO
NEVER TURN YOUR BACK TO THE WATER AND ALWAYS KEEP AN EYE OUT FOR
RAPIDLY APPROACHING WAVES.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: BELL
AVIATION: DRP
MARINE: DRP
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
300 AM PST WED DEC 9 2015
...WIDESPREAD RAIN AND LOCALLY GUSTY CONDITIONS ON THURSDAY...
.SYNOPSIS....LOOK FOR RAIN TO MOVE TO THE NORTH BAY LATER TODAY
AND THEN ACROSS OUR ENTIRE REGION ON THURSDAY AS A FRONT MOVES
THROUGH. GUSTY WINDS WILL ACCOMPANY ITS APPROACH AND PASSAGE.
SHOWERS AND POSSIBLE THUNDERSTORMS ARE THEN EXPECTED THURSDAY
NIGHT INTO FRIDAY AS A COOL AND UNSTABLE AIR MASS MOVES IN. MORE
WIDESPREAD RAIN IS SLATED FOR LATE SATURDAY THROUGH SUNDAY.
&&
.DISCUSSION...AS OF 3:00 AM PST WEDNESDAY...HIGH CLOUDS STREAMING
ACROSS OUR AREA THIS MORNING HAS HELPED TO KEEP TEMPERATURES
WARMER COMPARED TO YESTERDAY WITH MANY SPOTS 5 TO 10 DEGREES
AHEAD. IN ADDITION, SOME LOCATIONS HAVE SEEN FOG WITH VISIBILITIES
DOWN TO LESS THAN 1/2 A MILE ALTHOUGH MOST OBSERVATIONS ARE NOW
REPORTING VISIBILITIES GREATER THAN 3 MILES.
RAIN WILL ADVANCE TO THE NORTH BAY LATER THIS MORNING AS THE WEAK
RIDGE OVER US YESTERDAY FLATTENS AND MOVES TO THE EAST. 500 MB
FLOW WILL BEGIN TO SAG TO THE SOUTH ALLOWING MOISTURE BACK TO OUR
AREA. KBHX RADAR IS PICKING UP ECHOS ABOUT TO ENTER THE MENDO
COUNTY COAST WITH HRRR SHOWING THE LEADING EDGE GETTING TO THE
SONOMA COAST BY MID-MORNING TODAY. RAIN WILL SLOWLY CONTINUE TO
SPREAD TO THE SOUTH WITH A LITTLE LIGHT RAIN POSSIBLE INTO THE SF
BAY REGION BY THE AFTERNOON.
THIS ROUND OF RAIN IS A PRECURSOR TO THE BIGGER EVENT AS A COLD
FRONT WITH MODERATELY MOIST AIR (PW VALUES OF UP TO 1.20")
ADVANCES FROM THE NORTHWEST LATE TONIGHT AND CONTINUES INTO
THURSDAY. WIDESPREAD RAINFALL WILL MOVE INTO THE NORTH BAY LATE
TONIGHT THEN DOWN TO SF BAY REGION AROUND THE MORNING RUSH. THE
FRONT WILL CONTINUE TO THE MONTEREY BAY REGION AROUND BY EARLY
AFTERNOON. DURING THE FRONTAL PASSAGE, RAIN COULD BE MODERATE TO
HEAVY AT TIMES ALTHOUGH THE DURATION SHOULD BE FAIRLY SHORT. AFTER
A BREAK IN THE PRECIPITATION, SHOWERS WILL MOVE IN FROM THE
NORTHWEST AS THE ATMOSPHERE BECOMES MUCH MORE UNSTABLE.
THUNDERSTORMS WITH SMALL HAIL WILL ALSO BE POSSIBLE ESPECIALLY BY
TONIGHT AS THE MOST FAVORED DYNAMICS MOVE ACROSS OUR AREA. SHOWERS
LOOK LIKELY INTO FRIDAY AFTERNOON WITH DRY WEATHER EXPECTED TO
RETURN BY FRIDAY EVENING. MODELS ARE SUGGESTING THAT RAINFALL FROM
THE SHOWERS MAY END UP BEING GREATER THAN THE RAIN DURING THE
FRONTAL PASSAGE. RAINFALL TOTALS THROUGH FRIDAY MORNING ARE
EXPECTED TO BE 1-2" FOR THE NORTH BAY MOUNTAINS, UP TO AN INCH FOR
COASTAL RANGES OF SANTA CRUZ AND MONTEREY COUNTIES, AND 1/3" TO
2/3" FOR MANY METRO AREAS. SNOW LEVELS WILL DROP DOWN TO UNDER
4000 FEET BY FRIDAY MORNING WITH MINOR ACCUMULATIONS EXPECTED FOR
OUR HIGHEST PEAKS.
WIND WILL ALSO BE A FACTOR WITH INCREASING WEST TO SOUTHWEST WINDS
EXPECTED TONIGHT INTO THURSDAY. MODELS CONTINUE TO FOCUS THE
HIGHEST SPEEDS OVER THE NORTH BAY MOUNTAINS, SO WILL KEEP THE
ADVISORY GOING FOR THAT REGION. MOST LOCATIONS COULD SEE SPEEDS OF
15 TO 25 MPH WITH GUSTS TO 35 MPH.
SIMILAR TO TODAY, RAIN WILL GENERALLY BE CONFINED TO THE NORTH BAY
ON SATURDAY BEFORE SPREADING AGAIN ACROSS THE ENTIRE CWA AS
ANOTHER COLD FRONT MOVES THROUGH ON SUNDAY. ECMWF HAS BEEN
TRENDING WETTER WHICH IS MORE IN LINE WITH THE GFS SOLUTIONS OVER
THE PAST COUPLE OF DAYS. IN ADDITION, PW VALUES ARE NOW FORECAST
TO APPROACH 1.10" WHICH IS AN INCREASE OF AROUND .2" FROM
YESTERDAY. THEREFORE, RAINFALL AMOUNTS MAY HAVE THE POTENTIAL TO
REACH VALUES SIMILAR TO WHAT WE ARE EXPECTING THURSDAY INTO
FRIDAY. POPS WERE INCREASED FOR SATURDAY NIGHT THROUGH SUNDAY.
LONGER RANGE GUIDANCE FROM CPC ALSO FAVORS ABOVE NORMAL RAINFALL
FOR NEXT WEEK SUGGESTING A CONTINUED ACTIVE PATTERN.
&&
.AVIATION...AS OF 10:26 PM PST TUESDAY...MVFR/VFR WITH LOCALIZED
IFR CONDITIONS CONTINUING OVERNIGHT DUE TO A MIX OF CLOUDS AND
PATCHY FOG. KCCR AS WELL AS KSNS REPORTING 1/4 MILE VSBY IN FOG.
LIGHT RAIN WILL DEVELOP OVER THE NORTH BAY LATE TONIGHT AND
CONTINUE THROUGH WEDNESDAY. LIGHT RAIN ALSO POSSIBLE OVER THE REST
OF THE BAY AREA WEDNESDAY.
VICINITY OF KSFO...MVFR CIGS. LOWER CONFIDENCE IFR CIGS 09Z-18Z
TIMEFRAME. LIGHT RAIN POSSIBLE WEDNESDAY.
SFO BRIDGE APPROACH...SIMILAR TO KSFO.
MONTEREY BAY AREA TERMINALS...PATCHY IFR AROUND THE AREA DUE TO
FOG TONIGHT. LIGHT WINDS.
&&
.MARINE...AS OF 3:00 AM PST WEDNESDAY...A STRONG STORM SYSTEM
WILL CAUSE WINDS TO INCREASE LATE WEDNESDAY INTO THURSDAY
PRODUCING HAZARDOUS CONDITIONS. A VERY LARGE LONG PERIOD SWELL
WILL ARRIVE THURSDAY AND FRIDAY PRODUCING HAZARDOUS CONDITIONS
NEAR THE IMMEDIATE COASTLINE...ESPECIALLY ALONG COASTAL REEFS AND
SAND BARS AS WELL AS ACROSS THE SAN FRANCISCO BAR.
&&
.BEACHES...AS OF 3:00 AM PST WEDNESDAY...ANOTHER LARGE SWELL WILL
IMPACT THE COASTAL WATERS LATE TONIGHT THROUGH FRIDAY. SOME OF THE
MODEL GUIDANCE SUGGESTS THIS COULD BE THE BIGGEST SWELL OF THE
SEASON THUS FAR. LATEST FORECAST WILL HAVE SWELLS OVER 20 FEET IN
THE OUTER WATERS AND 15 TO 20 FEET IN THE INNER WATERS. THE PERIOD
IS GREATER THAN 16 SECONDS. THAT BEING SAID...WAVES BREAKING AT
THE COAST COULD EASILY EXCEED 20 FEET AND OVER 30 FEET AT DEEP
WATER BREAKS.
THESE LARGE BREAKING WAVES WILL PUSH WATER WELL UP ONTO THE BEACH
POSSIBLY WASHING PEOPLE FROM THE BEACH INTO THE SEA. LARGE SNEAKER
WAVES WILL ALSO BE POSSIBLE ON STEEP BEACHES SUCH AS CARMEL RIVER
BEACH AND MONTARA BEACH. PLEASE DO NOT CLIMB ON ROCKS OR JETTIES
ALONG THE COAST SINCE THESE AREAS WILL ALSO BE PRONE TO SNEAKER
WAVES. THESE WAVES WILL ARRIVE IN SETS WITH LONG LULLS BETWEEN
WAVE ACTIVITY WHICH COULD GIVE BEACH VISITORS A FALSE SENSE OF
SECURITY...DRAWING THEM CLOSER TO THE WATERS EDGE. REMEMBER TO
NEVER TURN YOUR BACK TO THE WATER AND ALWAYS KEEP AN EYE OUT FOR
RAPIDLY APPROACHING WAVES.
&&
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: BELL
AVIATION: CANEPA
MARINE: DRP
BEACHES: BELL/MM
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK AND TWITTER AT:
WWW.FACEBOOK.COM/NWSBAYAREA
WWW.TWITTER.COM/NWSBAYAREA
AREA FORECAST DISCUSSION...UPDATED
NWS NEW YORK NY
711 PM EST THU DEC 10 2015
.SYNOPSIS...
HIGH PRESSURE OVER THE SOUTHEAST U.S WILL MOVE OFFSHORE
TONIGHT...AND THEN A WARM FRONT LIFTS NORTH THROUGH THE REGION ON
FRIDAY. HIGH PRESSURE TO THE SOUTH WILL BE IN CONTROL THIS WEEKEND. A
STRONG FRONTAL SYSTEM WILL IMPACT THE AREA MONDAY INTO MONDAY
NIGHT WITH HIGH PRESSURE BUILDING IN FOR THE MIDDLE OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
AS IS TYPICAL IN THE EARLY EVENING HOURS AT THIS TIME OF YEAR...
CONDITIONS CAN RADIATE QUITE WELL WITH CLEAR SKIES AND LIGHT
WINDS. TEMPS ARE COOLER THAN PREVIOUSLY FORECAST FOR MOST
LOCATIONS. HOWEVER...A THICK CANOPY OF UPPER LEVEL CLOUDS MOVING
IN WILL LIKELY INSULATE THE AREA WITH TEMPS HOLDING NEARLY
STEADY. THIS COMPOUNDS HOW FAST THE FOG WILL DEVELOP TONIGHT.
HIGH PRES OVER THE SOUTHEAST U.S. WILL SLOWLY DRIFT TO THE EAST
AND MOVE OFFSHORE TONIGHT. SOUTHERLY FLOW WILL ALLOW FOR
WIDESPREAD LOW-LEVEL MOISTURE TO INCREASE THROUGHOUT THE REGION.
LATEST HIGH-RES ARW AND THE LATEST HRRR INDICATING VSBYS DROPPING
TO NEAR ZERO ACROSS MUCH OF LONG ISLAND...SOUTHERN CT...AND INTO
NYC. LATEST NARRE ALSO IN SIMILAR AGREEMENT.
DO NOT FEEL CONFIDENT ENOUGH TO ISSUE A DENSE FOG ADVISORY AT
THIS TIME...BUT WILL CARRY AREAS OF FOG THROUGHOUT...WITH PATCHY
DENSE FOG ACROSS NYC/LI/SOUTHERN CT.
LOWS TONIGHT WILL BE QUITE MILD...RANGING FROM THE 30S INLAND TO
NEAR 50 IN NYC.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
WARM FRONT LIFTS THROUGH THE REGION ON FRIDAY. FOG/LOW CLOUDS
SHOULD BURN OFF IN THE MORNING...GIVING WAY TO INCREASING SUNSHINE
IN THE AFTERNOON. SW FLOW USHERS A WARM AND MILD AIRMASS INTO THE
REGION...WITH HIGHS TOPPING OFF IN THE UPPER 50S TO LOW 60S. THESE
HIGHS ARE SOME 15 DEGREES ABOVE NORMAL...AND HIGH TEMPERATURE
RECORDS AT SOME OF THE FIRST ORDER CLIMATE SITES COULD BE MET. SEE
CLIMATE SECTION BELOW FOR DETAILS.
MILD AGAIN FRIDAY NIGHT WITH THE POTENTIAL FOR FOG. LOWS WILL BE
IN THE 30S INLAND TO NEAR 50 IN NYC.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
MODELS IN GOOD AGREEMENT WITH 1 TO 2 POSITIVE STANDARD DEVIATION
RIDGING OVER THE REGION THIS WEEKEND IN RESPONSE TO A DEEP TROUGH
AND DEVELOPING CLOSED LOW DIGGING INTO THE DEEP SOUTH. THIS CLOSED
LOW WILL THEN LIFT NE INTO THE GREAT LAKES AND THEN SOUTHERN
ONTARIO FOR THE START OF THE WORK WEEK. THIS WILL BRIEFLY FLATTEN
RIDGING MON AND TUE...BEFORE UPPER RIDGING BUILDS BACK FOR THE
EAST COAST AHEAD OF THE NEXT DEEP CENTRAL US TROUGH.
RIDGING THIS WEEKEND WILL MAINTAIN DRY WEATHER AND CONTINUE THE
ANOMALOUSLY MILD CONDITIONS WITH TEMPS IN THE LOWER TO MID 60S
ACROSS MUCH OF THE REGION (AROUND 15-20 DEGREES ABOVE
SEASONABLE). CLOUD COVER WILL BE THE MAIN ISSUE IN TERMS OF TEMPS
FORECAST...WITH SCT-BKN STRATOCU POSSIBLE UNDER A SUBSIDENCE
INVERSION...HIGH CLOUDS LIKELY ROUNDING THE RIDGE...AND OVERNIGHT
STRATUS/FOG WITH ANOMALOUSLY MOIST AIRMASS OVER THE REGION.
BACKDOOR COLD FRONT MAY MAKE A RUN AT THE REGION LATE
SUNDAY...BUT APPEARS AT THIS POINT THAT WE SHOULD BE IN WARM
SECTOR THROUGH THE WEEKEND. THIS FRONT MAY BE A FOCUS FOR SOME
ISOLATED SHOWER ACTIVITY SUNDAY NIGHT.
THE NEXT ITEM OF INTEREST...WILL BE STRONG LOW PRESSURE TRACKING NE
THROUGH THE GREAT LAKES SUN NIGHT INTO MON...WITH ITS ASSOCIATED
OCCLUDED/COLD FRONT APPROACHING THE REGION MON AFTERNOON AND
CROSSING THE REGION MONDAY NIGHT. INCREASING LARGE SCALE LIFT AND
APPROACHING WARM FRONT WILL INCREASE CHANCE OF RAIN SHOWERS
ACTIVITY LATE SUNDAY NIGHT INTO MONDAY. A 6 HR WINDOW OF MODERATE
TO HEAVY RAIN IS POSSIBLE DURING THE MON AFT INTO TUE EVE PERIOD
AS WARM CONVEYOR BELT OF AT LEAST 2-3+ STD PWATS DIRECTED TOWARDS
THE REGION AHEAD OF APPROACHING PIVOTING CLOSED LOW AND ASSOCIATED
FRONTAL SYSTEM. THIS RAIN WOULD BE IN COMBINATION WITH MODERATE
SOUTHERLY WINDS...WITH 55- 65 KT 950 HPA LLJ.
A STRONG PRESSURE GRADIENT...DECENT PRESSURE/RISE COUPLET...AND
FAVORABLE MOMENTUM TRANSFER IN THE WAKE OF THIS SYSTEM...MON
NIGHT INTO TUES...SIGNALS POTENTIAL FOR A PERIOD OF WIND ADVISORY
CONDITIONS. THE LIMITING FACTOR WOULD BE OVERNIGHT/EARLY MORNING
TIMING FOR THESE INGREDIENTS.
IN THE WAKE OF THE CLOSED LOW...DEEP LAYERED RIDGING SHOULD HAVE A
RETURN TO DRY AND CONTINUED UNSEASONABLY MILD CONDITIONS FOR THE
MIDWEEK. THE NEXT TROUGH AND FRONTAL SYSTEM APPEARS TO APPROACH
FOR LATE WEEK.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
HIGH PRESSURE MOVES WELL OFFSHORE TONIGHT. VFR IS FORECAST THROUGH
THIS EVENING AND THEN SUB-VFR WITH POCKETS OF IFR DEVELOPING LATER
TONIGHT. VFR AGAIN BY FRIDAY MIDDAY.
FOG DEVELOPMENT IS LIKELY OVERNIGHT. HOWEVER...THE EXACT MAGNITUDE
IS STILL UNCERTAIN DUE TO MID LVL CLOUDS ROLLING INTO THE REGION.
DENSE FOG IS MOST LIKELY AFT 07Z.
IT IS POSSIBLE SOME ARPT MINIMUMS COULD BE REACHED IN THE 8-12Z
TIME PERIOD.
LIGHT SW WIND 5-10 KT SHOULD BECOME VARIABLE AND/OR CALM
OVERNIGHT.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING AND CATEGORY
OF FOG OVERNIGHT.
KLGA FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING AND CATEGORY
OF FOG OVERNIGHT.
KEWR FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING AND CATEGORY
OF FOG OVERNIGHT.
KTEB FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING AND CATEGORY
OF FOG OVERNIGHT.
KHPN FCSTER COMMENTS: ARPT MINS POSSIBLE LATE TNGT INTO EARLY
FRI. AMENDMENTS LIKELY FOR TIMING AND CATEGORY OF FOG OVERNIGHT.
KISP FCSTER COMMENTS: AMENDMENTS LIKELY FOR TIMING AND CATEGORY
OF FOG OVERNIGHT.
.OUTLOOK FOR 00Z SAT THROUGH TUE...
.FRI NGT...VFR.
.SAT-SUNDAY...VFR.
.SUNDAY NIGHT...POSSIBLE MVFR OR LOWER CONDITIONS LATE.
.MON...MVFR OR LOWER CONDS IN RAIN.
.TUE...VFR WITH GUSTY NW WINDS.
&&
.MARINE...
HIGH PRES OFF THE SOUTHEAST U.S. COAST MOVES OFFSHORE TONIGHT. A
WARM FRONT LIFTS NORTH THROUGH THE WATERS ON FRIDAY...
OTHERWISE...HIGH PRES WILL KEEP CONDS BELOW SCA CRITERIA.
WIDESPREAD FOG WITH VSBY LESS THAN 1 NM MAY DEVELOP ON THE WATERS
TONIGHT. A DENSE FOG ADVISORY FOR THE WATERS MAY BE NEEDED TONIGHT
THROUGH FRIDAY MORNING.
TRANQUIL CONDITIONS THROUGH THE WEEKEND...ALTHOUGH DENSE FOG MAY
BE AN ISSUE AS AN UNSEASONABLY MOIST AIRMASS OVERRIDES THE AREA.
SCA CONDITIONS ARE LIKELY AND POSSIBLE BRIEF GALES MONDAY AFT/EVE
AHEAD OF APPROACHING COLD/OCCLUDED FRONT...WITH BETTER POTENTIAL FOR
GALES ON ALL WATERS AND A LOW CHANCE OF STORM FORCE WINDS ON THE
OCEAN WATERS LATE MON NIGHT INTO TUE MORNING. WILL MAINTAIN THIS
MENTION IN THE HWO.
&&
.HYDROLOGY...
THERE IS POTENTIAL FOR SIGNIFICANT RAINFALL (GREATER THAN 1/2
INCH) MONDAY AFTERNOON INTO TUESDAY EVENING.
&&
.CLIMATE...
HERE ARE THE RECORD HIGH TEMPERATURES FOR FRIDAY...DECEMBER 11.
EWR...65/1971*
BDR...65/1971
NYC...64/1879
LGA...62/1971
JFK...67/1971
ISP...57/2006
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MPS/NV
NEAR TERM...MPS/DW
SHORT TERM...MPS
LONG TERM...NV
AVIATION...JMC/IRD
MARINE...MPS/NV
HYDROLOGY...MPS/NV
CLIMATE...//
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
905 PM CST THU DEC 10 2015
.UPDATE...
ISSUED AT 900 PM CST THU DEC 10 2015
The post-frontal airmass is cooling much quicker than expected,
with CMI already down to 39 and GBG and BMI at 40. There is a band
of cirrus clouds approaching IL from the west, which should help
to limit the additional temp falls later tonight. Have updated the
low temps to put a few mid 30s in the traditional cold spots
along and north of I-74. The other concern is fog potential south
of I-70, especially toward Lawrenceville. Stratus and fog are
already forming in far southern IL, and that trend could progress
up the Wabash River Valley, per HRRR and RAP model output. Have
added a mention of fog S of I-70. There is potential that the fog
could become dense with less than 1/4 mile visibility, so will
watch closely for possible need for a dense fog advisory.
Updated forecast info will be available shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 305 PM CST THU DEC 10 2015
Southeasterly winds will become west to northwesterly as a sfc
trough pushes through the area late this afternoon through early
this evening. Gusty winds associated with the tighter gradient
this afternoon will continue some into the early evening hours
after the trough passage. As the trough passes, a weak/brief sfc
ridge will move into the area late tonight. Temps will fall into
the mid 30s in the northwest to the mid 40s in the southeast, with
mostly clear skies.
.LONG TERM...(Friday through Thursday)
ISSUED AT 305 PM CST THU DEC 10 2015
As the sfc ridge moves across the area tomorrow morning, winds
will be lighter and skies should become partly sunny. Once the
ridge passes tomorrow night, southerly winds will return and bring
in much warmer temps for the weekend. With the return to southerly
winds tomorrow afternoon, warm advection pcpn could move into the
east and southeastern sections of the CWA tomorrow afternoon into
tomorrow evening. For now, just looks like light showers.
Then, a stronger system will develop in the southwest US/plains
and begin to influence the weather across the CWA beginning Sat.
Again, warm advection showers will be possible in the west and
northwest starting Sat. Sat night, the sfc frontal system will get
closer to the area and bring moderate rain showers to the area
late Sat night, which will continue into Sunday and Sun night.
This system will be a stronger dynamic system with a good deal of
wind dynamics and shear. So, believe some isolated thunder could
be possible late Sat night and into Sunday. Showers should also
be moving quite quickly with mid level winds at 40-45kts. Models
have trended a little slower with this system so linger high pops
into Sunday night will be continued.
Temps through the weekend will be quite warm with record temps
possible Sat and Sunday. Temps will then begin to decrease some
after the weekend system.
Pcpn could linger some into Monday as the weekend system moves
quickly northeast out of the area. Then relative dry weather is
expected Monday night and Tue as another weak ridge moves through
the area. Southwest flow will continue through the week and this
will allow a short-wave trough and then a long wave trough to push
through the area for Tue night through Thur. For now, will stick
with the ensemble blend of slight chance pops for Tue night
through Thur and wait and see how models play things out after the
weekend. Temps will cool through the week as cloudy skies will
continue through the week. Temps will become even cooler as the
long wave trough rotates through the CWA toward the end of the
week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
ISSUED AT 551 PM CST THU DEC 10 2015
The 23z surface analysis showed a strong 987 mb low pressure
center over Lake Superior with a cold front extending south just
east of Illinois. With our area behind the cold front, winds have
backed to the west across the board. Wind gusts have quickly
subsided with sunset, and sustained winds will soon dip below
10kts at BMI and CMI, to go along with the lighter winds at the
other TAF sites.
As high pressure builds into Illinois on Friday, winds will veer
back to the S-SE and increase 10-12 kts Friday afternoon.
Satellite images show some lingering strato-cumulus early this
evening around 4-5K ft, otherwise VFR cirrus will be the primary
clouds of note overnight. Later Friday afternoon, warm advection
cloud cover will begin to overspread Illinois from the south, with
clouds in the 1500-2500Ft layer possibly mainly affecting our
eastern terminals of DEC and CMI, but could also affect SPI as
well.
&&
.CLIMATE...
ISSUED AT 255 AM CST THU DEC 10 2015
Record highs for the weekend:
Location Today Friday Saturday Sunday
Dec 10 Dec 11 Dec 12 Dec 13
-------- -------- -------- -------- --------
Bloomington 65 (1918) 65 (1949) 65 (1896) 63 (1975)
Champaign 65 (1889) 64 (1949) 62 (1991) 64 (1975)
Charleston 65 (1918) 66 (1931) 67 (1949) 64 (1991)
Decatur 66 (1918) 65 (1949) 65 (1929) 66 (1975)
Effingham 69 (1971) 60 (1979) 67 (1929) 65 (1991)
Lincoln 65 (1918) 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1889) 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1889) 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Auten
LONG TERM...Auten
AVIATION...Shimon
CLIMATE...07
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
1030 PM EST THU DEC 10 2015
.UPDATE...
ISSUED AT 1030 PM EST THU DEC 10 2015
THE LOW STRATUS IS STARTING TO FORM ACROSS THE AREA. EXPECT THIS
TO FILL OUT WITH TIME OVERNIGHT ALONG WITH A POTENTIAL FOR AREAS
OF FOG AND PATCHY DRIZZLE. HAVE UPDATED THE FORECAST TO REFLECT
THIS AND ALSO TO FINE TUNE THE THE T AND TD GRIDS PER THE LATEST
OBS AND TRENDS. OF NOTE...THE MOST SHELTERED VALLEYS IN THE EAST
SHOULD BE HITTING THEIR LOWS OVER THE NEXT HOUR OR SO WITH A
REBOUND AS THE STRATUS BUILDS. THESE UPDATED GRIDS HAVE BEEN
SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 740 PM EST THU DEC 10 2015
00Z SFC ANALYSIS SHOWS DEEP LOW PRESSURE MOVING INTO THE WESTERN
GREAT LAKES WHILE HIGH PRESSURE HOLDS ON OVER THE EASTERN
SEABOARD. BETWEEN THESE SYSTEMS...EASTERN KENTUCKY...REMAINS IN
THE MIDST OF BROAD SOUTHWEST FLOW KEEPING CONDITIONS MILD AND
MOIST. ON SATELLITE...THICK HIGH CLOUDS COVER THE AREA KEEPING
TEMPERATURES FAIRLY UNIFORM ACROSS THE CWA. EVEN SO...THEY VARY
FROM THE UPPER 40S IN THE DEEPER VALLEYS TO THE MID 50S ON THE
RIDGES. DEWPOINTS...MEANWHILE...ARE RUNNING IN THE MID TO UPPER
40S WITH LIGHT AND VARIABLE SFC WINDS. DO EXPECT STRATUS TO
DEVELOP LATER TONIGHT WITH A POTENTIAL FOR VERY LIGHT PCPN IN THE
FORM OF DRIZZLE TOWARDS DAWN. HAVE MAINTAINED THIS IN THE FORECAST
WITH SOME MINOR ADJUSTMENTS TO SKY COVER AND T/TD GRIDS PER THE
LATEST SHORTBLEND GUIDANCE...CURRENT OBS...AND TRENDS. THESE HAVE
BEEN SENT TO THE NDFD AND WEB SERVERS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 348 PM EST THU DEC 10 2015
HIGH PRESSURE SITTING TO OUR EAST...AND A LOW PRESSURE SYSTEM TO OUR
NORTHWEST HAS CREATED A GOOD FLOW OF SOUTH/SW WARM MOIST AIR INTO
THE REGION. THIS WILL CONTINUE TO PROMOTE TEMPERATURES EACH
DAY...WITH HIGHS TOMORROW HITTING THE MID 60S. MEANWHILE...WITH HIGH
PRESSURE STILL IN PLACE...A DECENT NEAR SURFACE TO MID LEVEL
INVERSION WILL REMAIN IN PLACE THROUGH THE PERIOD. THIS WILL TRAP
ANY OF THE LLVL SW FLOW MOISTURE...LEADING TO INCREASING LLVL CLOUDS
OVERNIGHT AND INTO THE DAY TOMORROW/TOMORROW NIGHT. MODELS ARE
CONTINUING TO SHOW MORE MOISTURE BEING PULLED INTO THE REGION
COMPARED TO PREVIOUS RUNS. AS SUCH...WPC IS NOW PEGGING PRECIP
ACROSS THE WESTERN HALF OF OUR CWA STARTING OVERNIGHT AND CONTINUING
INTO A GOOD PORTION OF THE DAY TOMORROW AS A COLD FRONT TO OUR NORTH
SAGS SOUTH TOWARDS THE OHIO RIVER. AS SUCH...WENT AHEAD AND EXPANDED
LIGHT RAIN POPS INTO OUR CWA OVERNIGHT AND INTO THE FIRST PART OF
THE DAY TOMORROW. FOR LOCATIONS NOT RECEIVING RAIN...ADDED IN
MENTION OF LIGHT DRIZZLE. ACCUMULATIONS SHOULD BE MINIMAL.
BY TOMORROW AFTERNOON...SOME DRY AIR WILL MOVE INTO THE REGION AS
THE FRONT SHIFTS BACK NORTHWARD. THIS SHOULD ALLOW DRIZZLE TO END
ACROSS EASTERN KY...AND SOME BREAK UP IN THE CLOUDS. A STRENGTHENING
INVERSION FRIDAY NIGHT WILL TRAP MOISTURE YET AGAIN...WITH ANOTHER
ROUND OF POSSIBLE DRIZZLE AND LLVL CLOUDS RETURNING. INSULATION BOTH
TONIGHT AND TOMORROW NIGHT...IN ADDITION TO THE CONTINUED SW
FLOW...WILL KEEP OVERNIGHT LOWS AROUND 50 DEGREES TONIGHT...AND
GENERALLY IN THE MID 50S BY FRIDAY NIGHT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 352 PM EST THU DEC 10 2015
MID LEVEL RIDGING WITH SFC HIGH PRESSURE WILL BE DOMINATING THE
SENSIBLE WEATHER FOR THE START OF THE EXTENDED PERIOD. TEMPERATURES
ARE EXPECTED TO REACH NEAR RECORD VALUES DURING THIS TIME WITH HIGHS
FLIRTING WITH THE 70 DEGREE MARK BOTH SATURDAY AND SUNDAY.
MEANWHILE...A DEEP TROUGH OVER FOUR CORNERS REGION WILL GRADUALLY
MAKES ITS WAY TO THE SOUTHERN PLAINS ON SUNDAY. THE TROUGH AND SFC
LOW REFLECTION WILL MOVE INTO THE OH VALLEY MONDAY MORNING ALLOWING
FOR A COLD FRONT TO EXTEND SOUTHWARD INTO THE TN VALLEY. THIS SYSTEM
WILL QUICKLY MOVE THROUGH THE AREA MONDAY...BUT NOT BEFORE DROPPING
UP TO THREE QUARTERS OF AN INCH OF RAIN OVER EASTERN KY. RAIN
ACCUMULATIONS WILL DEPEND ON HOW QUICKLY THE SYSTEM PUSHES
THROUGH...AND IF ANY CONVECTIVE SHOWERS ARE REALIZED. BOTH THE GFS
AND ECMWF MODELS SHOW HIGH TQ VALUES MONDAY MORNING INTO AFTERNOON
WITH THE PASSAGE OF THE FRONT...SO THIS MAY BE ENOUGH TO WARRANT
SOME ISOLATED THUNDER...EVEN THOUGH MODEL SOUNDINGS DO NOT SHOW MUCH
INSTABILITY. GUSTY WINDS ARE ALSO A CONCERN IF THE 850 WINDS MIX
DOWN TO THE SFC. SO WILL INCLUDE BOTH MENTION OF GUSTY WINDS AND
ISOLATED THUNDER IN THE HWO.
MID LEVEL RIDGING BUILDS BACK INTO THE REGION TUESDAY BEFORE ANOTHER
LOW PRESSURE SYSTEM FORMS AND MOVES TOWARDS THE GREAT LAKES ON
WEDNESDAY. BOTH MODELS BRING PRECIPITATION INTO EASTERN KENTUCKY
DURING THE WEDNESDAY/THURSDAY TIME FRAME BUT THERE ARE SUBSTANTIAL
DIFFERENCES BETWEEN THE TIMING AND AMOUNT OF PRECIP. THE ECMWF
DEEPENS THE UPPER LEVEL TROUGH BRINGING PRECIP INTO THE AREA EARLIER
THAN THE GFS. WITH THIS MUCH UNCERTAINTY...WILL STICK CLOSE TO THE
SUPERBLEND. TEMPERATURES DURING THE LATTER HALF OF THE EXTENDED
PERIOD WILL BE A BIT COLDER BUT STILL REMAIN ABOVE NORMAL.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 645 PM EST THU DEC 10 2015
CONDITIONS ARE CURRENTLY VFR THROUGH EASTERN KENTUCKY UNDER A
THICK LAYER OF HIGH CLOUDS. HOWEVER....A NOCTURNAL INVERSION WILL
LIKELY TRAP MOISTURE NEAR THE SURFACE...PROMOTING RENEWED LOW
STRATUS DEVELOPMENT LATER TONIGHT. IT IS PROBABLE THAT MOST TAF
SITES WILL SEE CIG RESTRICTIONS IN THE IFR AND LIFR RANGE...
GENERALLY AFTER 7Z...BUT SOME DENSER FOG AND PATCHES OF DRIZZLE
CANNOT BE RULED OUT. THERE WILL BE A CONTINUED INFLUX OF LLVL
MOISTURE THROUGH TOMORROW...KEEPING IFR AND LIFR CIGS IN PLACE
WITH A GRADUAL LIFTING TREND THROUGHOUT THE DAY. WINDS WILL
AVERAGE 5 TO 10 KTS DURING THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JMW
LONG TERM...JVM
AVIATION...GREIF
[top]
Area Forecast Discussion
National Weather Service Louisville KY
924 PM EST THU DEC 10 2015
...Forecast Update...
Updated at 920 PM EST Thu Dec 10 2015
Minor adjustments made to the overnight forecast, but for the most
part it`s on track. Latest IR imagery and GOES-R probability tools
show lower ceilings associated with the warm, moist southerly flow
beginning to take shape across western TN, southwest KY. This low-
level moisture plume is on track to surge northeastward into central
Kentucky overnight.
Latest soundings and RAP forecasts show a steady southwest wind just
off the deck, which may keep this low-level moisture more stratus
than fog. 11.00z OHX sounding shows moisture rooted at around 900
mb, and RAP RH fields at this layer suggest this moisture overtaking
the area between 06-09z. Will continue mention of fog, some dense,
in the forecast but it may end up being a low stratus deck that
lasts well into Friday.
Otherwise, mild night is on tap with lows expected to not stray too
far from current readings (upper 40s to mid 50s).
.SHORT TERM (Now through Friday Night)...
Issued at 315 PM EST Thu Dec 10 2015
Expect a few peeks at the sun through the remainder of the
afternoon, although variable cloudiness should hang over the region.
Temps should mostly remain in the 50s for the remainder of the
afternoon.
Low level clouds will again increase overnight as low level moisture
is trapped under a shallow inversion and an isentropic lift
component picks up. Will go with low chances for measurable
precipitation, and mention of drizzle given the shallow moisture.
Also concerned about low stratus build down into some impactful fog
so will mention patchy/areas for now. Not sure how dense it will get
given the steady south low level winds and an uptick in near surface
winds, however this did not stop dense fog from setting in last
night. Will mention in the HWO and continue to evaluate for possible
headlines.
Expect a small diurnal trend given the steady south winds and cloud
cover. Lows will only be in the upper 40s and lower 50s.
The devloping warm front will begin to lift north over the area
Friday and Friday night as we switch to deeper SW flow through the
column in response to an amplifying pattern. This will shift main
showery precip chances to mainly our northern CWA. We`ll also see
milder temps across the south in the mid and upper 60s. Expect temps
to reach the low 60s north on the warm advection component.
Another mild night Friday night as we stay in the warm sector. We`ll
keep small chances for measurable showers mainly across the north.
Lows only expected to drop into the upper 50s to around 60 given the
steady warm advection.
.LONG TERM (Saturday through Thursday)...
Issued at 325 PM EST Thu Dec 10 2015
Saturday - Sunday...
The pattern continues to amplify through the weekend as a potent
upper disturbance digs a trough into the southern Plains and SE
CONUS ridge tries to hold. This puts the Ohio River Valley in deep
SW flow, although the dry warm sector should keep things mostly dry,
very mild, and windy.
Expect a few isolated showers to quickly leave southern IN by midday
Saturday with the southerly winds increasing as the pressure
gradient tightens between the southern Plains low and surface high
to our east. This will help temps rise near and around the 70 degree
mark under more peeks at the sun and increasing heights/thicknesses.
Saturday record high temperatures are in real jeopardy as they are
at 68 for all 4 major climate sites and we are forecasting a tie or
break at each. Most notably, the record high of 68 at LEX dates all
the way back to 1873!
A mild Saturday night will also put record warm minimums in jeopardy
as the strong warm advective component increases. Only expecting
lows in the mid 50s to around 60.
As we move into Sunday, pressure gradient tightens even more, to the
point where a Wind Advisory will be a good bet. Low level thermal
profiles look to support mixing up into a layer where gusts in the
30-40 mph range aren`t out of the question. This strong southerly
flow combined with some sun should allow for even warmer temps into
the low 70s. Some guidance even suggests mid 70s which isn`t out of
the question. The one limiting factor could be cloud cover.
Sunday Night - Monday...
Strong upper anomaly ejects out of the southern Plains into the
Great Lakes Sunday evening into Monday, taking on a negative tilt as
it does. This will bring a deep moisture plume over our region as a
low level jet increases in response to the upper jet arrival. We`ll
keep the strong gradient winds in place through the evening ahead of
the front, meanwhile widespread and a strongly forced line of
showers will move through. Still not overly impressed with
instability potential, but given the warm day ahead and continued
warm advection, enough surface based instability may develop for
some stronger gusts to mix down in showers/storms that evening.
Additionaly, some heavy rainfall is possible, although the overall
system is progressive enough that no major concerns are warranted.
Overall QPF should range around 1 inch with some spots seeing
locally higher amounts.
Cold front pushes through later Sunday night into Monday with
lingering showers clearing from SW to NE through the day. Expect
cooler highs back in the 50s (not a statement you see too often in
mid december!).
Monday Night - Thursday...
Progressive upper ridge and surface high pressure keep us dry and
cooler through Tuesday night, although not a substantial airmass
change. Look for highs mostly in the 50s and lows in the 39-43 range.
Chances for rain return Wednesday through Thursday as another front
progresses through our deep SW flow pattern. Confidence is a little
sketchy on timing so will mention low chances for now. A secondary
cool down will occur behind this boundary, with cold air trying to
catch up to any lingering moisture Wednesday night into Thursday.
Will hold off on any frozen precip mention as this scenario rarely
works out.
&&
.AVIATION (00Z TAF Update)...
Updated at 615 PM EST Thu Dec 10 2015
Messy aviation forecast through the period as warm, moist air surges
northward into central Kentucky. Latest IR imagery with GOES-R probs
of IFR/MVFR show some evidence of lower ceilings coming back from
southern/southwest TN already, and this should begin to arrive
across KY in a few hours.
Plan on IFR ceilings at BWG toward midnight, followed at SDF/LEX a
few hours later. Soundings become very saturated below 4 kft and
with weak lift, there could be light drizzle or rain showers. MVFR
to high-end IFR fog also possible as well, especially at BWG.
Soundings show a strong 40 kt jet at about 2 kft, so LLWS is also a
concern. It`s borderline at all sites since surface winds remain
elevated at 8-10 kts. The surface pressure gradient should remain
tight through this evening, so will hold off including that in this
TAF issuance. But the target times for greatest LLWS threat would be
03-09z.
Low clouds/visbys will remain in place across the area through the
day Friday with just a slight improvement expected in ceilings.
Southerly flow will persist with winds 7-10 kts.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........ZT
Short Term.....BJS
Long Term......BJS
Aviation.......ZT
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
141 PM EST WED DEC 9 2015
.UPDATE...
ISSUED AT 141 PM EST WED DEC 9 2015
A FEW RADAR RETURNS HAVE POPPED UP ACROSS THE AREA IN THE PAST FEW
HOURS. SO FAR...THESE HAVE NOT PRODUCED MUCH MORE THAN A FEW
SPRINKLES AT BEST. THE LATEST HRRR MODEL RUNS CONTINUE TO SHOW A
BIT OF AN UPTICK ACROSS OUR SOUTHEAST THROUGH THIS EVENING...SO
WILL STICK WITH THE CHANCE POPS FOR NOW. ALSO FRESHENED UP THE
SKY COVER AND HOURLY TEMPERATURES AND DEW POINTS TO JIVE BETTER
WITH THE CURRENT OBSERVATIONS. UPDATES HAVE BEEN SENT.
UPDATE ISSUED AT 1031 AM EST WED DEC 9 2015
MOSTLY CLOUDY SKIES ARE CURRENTLY ON OUR DOORSTEP...AS A SHORT
WAVE TROUGH MOVES THROUGH WESTERN KENTUCKY/TENNESSEE. SO
FAR...THE RADAR ECHOES HAVE BEEN NON-EXISTENT...BUT THE LATEST
SHORT MODEL GUIDANCE CONTINUES TO ADVERTISE AN UPTICK IN ACTIVITY
THIS AFTERNOON. AS SUCH...HAVE ONLY DELAYED THE POPS A BIT MORE
TOWARDS THE LATEST MODEL TRENDS. ALSO...WENT A BIT HIGHER IN THE
SOUTHEAST LATE THIS AFTERNOON...WHERE SLIGHTLY BETTER MOISTURE
WILL POOL. THE FORECAST HIGHS LOOK ON TRACK...AND HAVE ONLY
FRESHENED UP THE HOURLY TEMPERATURES TO ACCOUNT FOR THE SLOWER
DIURNAL RISE IN SOME OF THE MORE SHELTERED VALLEYS THIS MORNING.
&&
.SHORT TERM...(TODAY THROUGH THURSDAY)
ISSUED AT 308 AM EST WED DEC 9 2015
A FAST MOVING MOISTURE STARVED UPPER LEVEL WEATHER SYSTEM IS
FORECAST TO MOVE ACROSS THE LOWER GREAT LAKES AND OHIO VALLEY
REGIONS TODAY...BRINGING LIGHT RAIN SHOWERS TO EASTERN KENTUCKY AS
IT DOES SO. BASED ON THE SPEED OF THE SYSTEM AND THE LACK OF A
GOOD MOISTURE FEED FOR IT TO INTERACT WITH...PRECIPITATION CHANCES
FOR TODAY WERE LEFT FAIRLY LOW. A GENERAL 20 TO 30 PERCENT CHANCE
OF RAIN IS ON TAP FOR TODAY ACROSS THE AREA. CLOUD COVER WILL BE
ON THE INCREASE EARLY THIS MORNING AS THE SYSTEM APPROACHES...WITH
THE FIRST RAIN SHOWERS EXPECTED TO ENTER THE WESTERN COUNTIES OF
OUR AREA BETWEEN 17 AND 18Z TODAY. THE LAST OF THE RAIN SHOULD BE
EXITING EASTERN KENTUCKY BETWEEN 7 AND 8Z TONIGHT. ONLY VERY LIGHT
RAINFALL ACCUMULATIONS ARE EXPECTED. TEMPERATURES BOTH TODAY AND
TOMORROW WILL BE RUNNING ABOVE NORMAL...WITH HIGHS TODAY AND
THURSDAY TOPPING OUT IN THE MID AND UPPER 50S RESPECTIVELY.
OVERNIGHT LOWS SHOULD ONLY FALL INTO THE MID 40S DUE TO EXTENSIVE
CLOUD COVER AND LIGHT SOUTHERLY FLOW.
.LONG TERM...(THURSDAY NIGHT THROUGH TUESDAY)
ISSUED AT 430 AM EST WED DEC 9 2015
THE PERIOD IS EXPECTED TO BEGIN WITH RIDGING EXTENDING FROM THE
PACIFIC EAST ACROSS MEXICO AND INTO THE WESTERN GULF OF MEXICO.
A TROUGH IS EXPECTED TO BE PUSHING ONSHORE OF THE WESTERN CONUS
WITH A TROUGH MOVING INTO THE WESTERN GREAT LAKES. AT THE SFC..A
LOW PRESSURE SYSTEM ASSOCIATED WITH THE TROUGH MOVING INTO THE
GREAT LAKES SHOULD TRACK INTO ONTARIO AND SEND A COLD FRONT TOWARD
THE OHIO VALLEY WHERE IT SHOULD STALL BEFORE LIFTING NORTH TO
START THE WEEKEND. THE PATTERN IS EXPECTED TO AMPLIFY EARLY IN THE
PERIOD WITH HEIGHTS RISING ACROSS THE APPALACHIAN REGION ON FRIDAY
AS RIDGING BUILDS FROM THE GULF OF MEXICO INTO THE SOUTHEASTERN
CONUS. AT THE SAME TIME A TROUGH SHOULD DIG SOUTH INTO THE DESERT
SOUTHWEST. AT LEAD SHORTWAVE SHOULD LEAD TO A SFC LOW TRACKING
NORTHWEST OF THE AREA FRIDAY NIGHT...WITH THE BOUNDARY THAT DROPS
TOWARD THE OH RIVER EARLY IN THE PERIOD LIFTING INTO THE GREAT
LAKES AS A WARM FRONT. THIS WILL LEAVE THE REGION IN THE WARM
SECTOR TO START THE WEEKEND...AND LIGHT SHOWERS OR SPRINKLES
CANNOT BE RULED OUT AS THE BOUNDARY DROP INTO THE OHIO VALLEY ON
FRIDAY AND THEN LIFTS NORTH THROUGH EARLY ON SATURDAY.
OTHERWISE...WITH THE RIDGE BUILDING TOWARD BERMUDA BEFORE SHIFTING
OFF THE EASTERN SEABOARD AND THE CURRENT MODEL CONSENSUS OF A
DEEPER/SLOWER TROUGH...AT LEAST FOR NOW...MUCH OF SATURDAY INTO
MIDDAY SUNDAY SHOULD END UP DRY ALTHOUGH CLOUDS WILL PASS BY FROM
TIME TO TIME. THE CURRENT MODEL CONSENSUS IS FOR THE TROUGH TO
APPROACH THE MS VALLEY LATE ON SUNDAY AND THEN MOVE INTO THE
EASTERN CONUS ON SUN NIGHT...WITH THE SFC COLD FRONT PRECEDING
THIS ENTERING THE LOWER OH VALLEY ON SUN AFTERNOON AND EVENING.
THERE STILL REMAINS RUN TO RUN AND MODEL TO MODEL VARIABILITY IN
THE DEPTH OF THE TROUGH LEADING TO SPREAD IN THE TRACK OF THE SFC
LOW INTO THE GREAT LAKES REGION. RECENT MODEL RUNS POINT TOWARD
THE TROUGH AXIS NOT MOVING EAST OF THE AREA UNTIL THE DAY ON
MONDAY WITH THE COLD FRONT MOVING ACROSS SOUTH CENTRAL AND EASTERN
KY ON SUN NIGHT INTO EARLY ON MONDAY MORNING. WARM ADVECTION
AHEAD OF AN APPROACHING COLD FRONT AND A DOWNSLOPE COMPONENT OFF
THE HIGHER TERRAIN OF NE TN AND SW VA MAY LEAD TO NEAR RECORD OR
RECORD HIGHS AT LOZ AND JKL FOR SAT AND SUN. MORE CLOUD COVER THAN
ANTICIPATED COULD KEEP TEMPERATURES FROM ACHIEVING THESE VALUES.
OVERALL...THE SOUTHEASTERN PART OF THE AREA NEAR THE VA BORDER AND
ACROSS THE BIG SANDY REGION STANDS THE BEST CHANCE TO NEAR OR
POSSIBLY EXCEED 70 DEGREES ON ONE OR BOTH DAYS.
INSTABILITY PARAMETERS ARE GENERALLY MEAGER WITH THIS SYSTEM...SO
THUNDER CHANCES APPEAR TOO LOW TO INCLUDE ATTM. HOWEVER..THE
PRESSURE GRADIENT WILL INCREASE AS THE END OF WEEK SYSTEM
APPROACHES AND WINDS SHOULD INITIALLY BE RATHER STRONG AND GUSTY
ACROSS THE HIGHER TERRAIN BY MIDDAY ON SUN...AND SOME OF THIS
HIGHER MOMENTUM COULD MIX DOWN TO LOWER ELEVATIONS DURING THE SUN
AFTERNOON TO MON AFTERNOON PERIOD ALTHOUGH WINDS ALOFT APPEAR
STRONGEST FROM LATE SUN AFTERNOON INTO SUN NIGHT. THE DOWNSLOPE
COMPONENT AND THE POTENTIAL FOR MORE VIGOROUS CONVECTION ALONG THE
GULF COAST STATES MAY LEAD TO A DRY DAY ON SUN IN THE FAR
SOUTHEAST AND LESS QPF AREA WIDE THAN SOME OF THE EARLIER MODEL
RUNS. EVEN SO...A SOAKING RAIN WILL PROBABLY OCCUR WITH THIS
SYSTEM...BUT WIDESPREAD 1 INCH OR HIGHER AMOUNTS SEEM LESS
PROBABLE AT THIS TIME. THE HIGHEST POPS AREA WIDE SHOULD OCCUR ON
SUNDAY NIGHT WHERE LIKELY WAS USED.
A RIDGE OF HIGH PRESSURE WILL NOSE INTO THE AREA TO END THE
PERIOD WITH DRY WEATHER ANTICIPATED. EVEN BEHIND THIS
FRONT...TEMPERATURES SHOULD REMAIN ABOVE NORMAL INTO THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 141 PM EST WED DEC 9 2015
VFR CONDITIONS WILL GIVE WAY TO MVFR CEILINGS FROM WEST TO EAST
THROUGH 22Z. A FEW SHOWERS WILL DOT THE AREA THROUGH THIS EVENING
AS WELL...BUT THESE WILL BE LIGHT AND LIKELY NOT RESTRICT
VISIBILITIES TO LESS THAN VFR. CEILINGS WILL CONTINUE TO LOWER
LATER TONIGHT...WITH SOME IFR CONDITIONS EXPECTED JUST BEFORE
DAWN. A GRADUAL IMPROVEMENT TO MVFR WILL THEN OCCUR THROUGH
THURSDAY MORNING. SOUTH TO SOUTHWEST WINDS WILL AVERAGE BETWEEN 5
AND 10 KTS THROUGH THE PERIOD.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GEOGERIAN
SHORT TERM...AR
LONG TERM...JP
AVIATION...GEOGERIAN
AREA FORECAST DISCUSSION
NWS CARIBOU ME
757 PM EST THU DEC 10 2015
.SYNOPSIS...
HIGHER PRESSURE WILL BRIEFLY BUILD ACROSS THE REGION OVERNIGHT.
ABUNDANT LOW LEVEL MOISTURE WILL KEEP SKIES MAINLY CLOUDY OVERNIGHT
WITH AREAS OF FOG AND DRIZZLE. ANOTHER UPPER DISTURBANCE WILL
APPROACH THE REGION FRIDAY AND CROSS THE REGION FRIDAY NIGHT. HIGH
PRESSURE WILL BUILD IN FOR SATURDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
740 PM UPDATE: DECIDED TO GO AHEAD W/AREAS OF DRIZZLE FOR MUCH OF
THE CWA THROUGH THE OVERNIGHT PERIOD. 00Z CAR RAOB SHOWED THAT
SETUP W/DEEP MOISTURE TRAPPED BLOW 700MBS W/INVERSION AROUND
720MBS THIS EVENING. LATEST HRRR AND RAP GUIDANCE INDICATE CLOUDS
TO HANG AROUND OVERNIGHT DESPITE THE DRY AIR ABOVE 700MBS. FOG AND
DRIZZLE SHOULD HANG ON THROUGH EARLY FRIDAY MORNING. TEMPS WILL
DROP BACK A FEW DEGREES BY REMAINING WELL ABOVE 32F.
LOW TEMPERATURES TONIGHT ARE NOT EXPECTED TO FALL ALL THAT MUCH
FROM THIS AFTERNOON HIGHS WITH ABUNDANT LOW LEVEL MOISTURE IN
PLACE. EXPECT LOWS MAINLY IN THE MID TO UPPER 30S NORTH AND LOW
TO MID 40S DOWN EAST.
FRIDAY WILL BE A MAINLY CLOUDY AND UNSEASONABLY MILD DAY. A
WEAK DISTURBANCE WILL MOVE ACROSS THE GULF OF MAINE IN ADVANCE OF
A STRONGER UPPER DISTURBANCE MOVING THROUGH QUEBEC. MOISTURE
IS LIMITED SO WE ARE NOT EXPECTING MUCH IN THE WAY OF ANY
PRECIPITATION WITH THIS SYSTEM OTHER THAN A FEW SHOWERS WILL BE
POSSIBLE ACROSS DOWN EAST MAINE DURING FRIDAY AFTERNOON.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
FRIDAY NIGHT A WEAK 500MB SHORTWAVE TROUGH WILL BE MOVING DIRECTLY
OVER NORTHERN MAINE...WITH A WEAK COLD FRONT PUSHING OFF THE COAST
THROUGH THE NIGHT. A FEW RAIN SHOWERS ARE EXPECTED ACROSS THE
NORTH WOODS AND SAINT JOHN VALLEY...WITH THE REMAINDER OF THE
STATE REMAINING DRY. PARTIAL CLEARING ON SATURDAY AND SLIGHTLY
COOLER THEN FRIDAY...BUT STILL UNSEASONABLY WARM WITH HIGHS IN THE
40S. ZONAL FLOW EXPECTED ALOFT. SUNDAY WILL BE COOLER AS A
BACKDOOR COLD FRONT ON NORTHWEST WINDS PUSHES SLIGHTLY COLDER AIR
INTO THE REGION...BUT STILL RUNNING ABOVE AVERAGE. PARTLY SUNNY
AGAIN...WITH HIGH AND MID CLOUDS ON THE INCREASE THROUGH THE
DAY BUT IT WILL BE DRY. OVERALL A DESCENT WEEKEND ON TAP FOR MID-
DECEMBER.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE EXTENDED MODELS ARE IN GOOD AGREEMENT AT THE START OF THE
PERIOD. A WARM FRONTAL SYSTEM WILL EXTEND ACROSS SW MAINE INTO THE
DOWNEAST COAST. THE ASSOCIATED LOW WILL BE OVER NE MO...WITH A
COLD FRONT EXTENDING INTO THE GULF OF MEXICO. HIGH PRESSURE WILL
BE EAST OF THE COAST OF VA IN THE NORTH ATLANTIC. MON MRNG THE
WARM FRONT WILL MOVE NE FROM WRN ME TO SE WASHINGTON COUNTY.
HIGHER PRESSURE RIDGES INTO WRN ME BEHIND THE WARM FRONT. THE
GUIDANCE SHOWS THE LOW OVER MOVE NE TO NRN LAKE MI. THE LOW BY
THIS POINT WILL BE A MATURE LOW WITH THE ASSOCIATED UPPER LOW OVER
NRN IL. THE COLD FRONT MOVE EAST TO OHIO...THE OCCLUDED FRONT
WRAPPED AROUND THE LOW BACK TO NRN MO. MON EVNG THE COLD FRONT
MVOE EAST TO NH/ME BORDER. THE SFC LOW MOVES TO THE BORDER OF
QUEBEC/ONTARIO THE UPPER LOW TO ERN LAKE HURON. TUES MRNG THE COLD
FRONT MOVES INTO NEW BRUNSWICK...A SECONDARY LOW DEVELOPS OVER
ME/NB BORDER...CLOSELY ASSOCIATED WITH THE UPPER LOW NOW LOCATED
ALONG THE WRN QB/ME BORDER. BY TUES EVNG THE SYSTEM MOVES EAST OF
THE AREA AND HIGHER PRESSURE BUILDS IN. THE HIGH PRESSURE WILL
DOMINATE THE WEATHER THROUGH THURS MRNG. A COLD FRONT WILL THURS
AFTERNOON AND WILL SLOWLY TRANSIT THROUGH THE AREA...AND WILL
REMAIN OVER DOWNEAST ME BY THE END OF THE PERIOD.
LOADED A BLEND TO SMOOTH OUT DIFFERENCES IN THE MODELS THROUGH
THE PERIOD. LOADED NAWAVE4 FOR SEAS...USED WIND GUSTS FROM FACTOR
TOOL FOR GUSTS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: EXPECT WIDESPREAD IFR/LIFR CONDITIONS AT ALL THE WFO
CARIBOU TERMINALS OVERNIGHT IN LOW CIGS/AREAS OF FOG AND DRIZZLE
ALONG WITH LIGHT/CALM SFC WINDS. EXPECT LIFR/IFR EARLY FRIDAY
MORNING TO GIVE WAY TO MVFR BY MIDDAY.
SHORT TERM: IFR CONDITIONS ARE EXPECTED IN THE SHORT TERM FORECAST
WITH NO SIGNIFICANT IMPACTS TO AVIATION OPERATIONS EXPECTED. A FEW
LIGHT RAIN SHOWERS ARE POSSIBLE FRIDAY NIGHT ACROSS THE NORTHERN
TAF TERMINALS.
&&
.MARINE...
NEAR TERM: SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH 9 PM
THIS EVENING. AREAS OF FOG WILL REDUCE VISIBILITY AT TIMES
OVERNIGHT. WINDS/SEAS WILL REMAIN BELOW SMALL CRAFT ADVISORY ON
FRIDAY.
SHORT TERM: WEAK SURFACE COLD FRONT WILL PUSH OFF THE COASTAL
WARTERS FRI NIGHT. OFF SHORE FLOW EXPECTED THROUGH THE WEEKEND
WITH SEAS REMAINING BELOW SMALL CRAFT ADVISORY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 9 PM EST THIS EVENING FOR ANZ050-
051.
&&
$$
NEAR TERM...DUDA/HEWITT
SHORT TERM...DUMONT
LONG TERM...NORTON
AVIATION...DUDA/HEWITT/DUMONT
MARINE...DUDA/HEWITT/DUMONT
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1242 AM EST WED DEC 9 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA TONIGHT THROUGH
WEDNESDAY. THE HIGH WILL MOVE EAST WEDNESDAY NIGHT AS A WEAK
TROUGH OF LOW PRESSURE APPROACHES FROM THE WEST. THIS TROUGH IS
EXPECTED TO CROSS THE REGION ON THURSDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
11:30 PM UPDATE...MODIFIED SOME TEMPERATURES ACROSS THE NORTH
WHERE SOME VALLEYS HAVE BEGUN TO COOL QUICKLY. ALSO MODIFIED
CLOUD COVER JUST A BIT WITH SOME MID AND HIGH CLOUDS BEGINNING TO
MOVE INTO WESTERN AREAS. RADAR SHOWS SOME WEAK ECHOES IN THE FAR
NORTHWEST SO INCLUDED A SLIGHT CHANCE OF SNOW SHOWERS IN THE
NORTHWEST. OTHERWISE, NO MAJOR CHANGES THIS HOUR.
PREVIOUS DISCUSSION... MAIN CHALLENGE THIS TERM AS HAS BEEN THE
PAST FEW DAYS WILL BE THE CLOUDS AND TEMPS.
SURFACE ANALYSIS SHOWED LOW PRES PASSING WELL SE OF THE AREA W/THE
MID AND HIGH CLOUDS ASSOCIATED W/IT STARING TO PULL OUT OF THE
DOWNEAST AND COASTAL AREA. FURTHER N AND W, SATELLITE IMAGERY
SHOWED SOME CLOUDS AROUND AS WEAK UPPER IMPULSE PASSES BY TO THE N
DESPITE HIGH PRES AT THE SURFACE. DOWNEAST AND THE COAST SHOULD
REMAIN MOSTLY CLEAR OVERNIGHT W/HIGH PRES PULLING E. THOSE CLOUDS
ACROSS THE NORTHERN SECTIONS WILL SLOWLY ERODE THIS EVENING, BUT
MORE CLOUDS ARE FORECAST TO SET UP LATER TONIGHT AS A LIGHT ESE
FLOW SETS UP ALLOWING FOR MOISTURE TO GET TRAPPED UNDER THE
INVERSION. THE HRRR DOING WELL W/CURRENT SETUP AND SHOWED THE LLVL
MOISTURE SETTING UP OVER EASTERN AND NORTHERN SECTIONS AFTER
MIDNIGHT. TEMPS WILL VARY OVERNIGHT DEPENDENT ON THE CLOUDS. THIS
WILL MAKE IT FOR A TOUGHT FORECAST. DECIDED TO GO W/UPPER TEENS TO
LOWER 20S ACROSS THE NORTHERN 1/2 OF THE CWA W/THE COLDEST TEMPS
IN THE LOW LYING AREAS AND NEAR RIVER VALLEYS. STAYED W/MID-UPPER
20S DOWNEAST AND THE COAST. THIS WILL NEED TO BE MONITORED AS SOME
OF THE LOW LYING AREAS IN THIS REGION COULD GO COLDER DEPENDING ON
LONGEVITY OF THE CLEARING. PATCHY FOG POSSIBLE ESPECIALLY ALONG
THE RIVER VALLEYS.
LOW CLOUDS WILL TAKE SOME TIME TO ERODE WEDNESDAY MORNING W/THE
WEAK SE FLOW IN PLACE. DIRUNAL EFFECTS SHOULD AID IN ALLOWING FOR
THE CLOUD DECK TO LIFT AND DISSIPATE SOME W/SUNSHINE. DAYTIME
TEMPERATURES WILL BE A BIT ABOVE NORMAL FOR EARLY DECEMBER.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
HIGH PRESSURE WILL MOVE OFF THE COAST WEDNESDAY NIGHT WHILE AT
THE SAME TIME LOW PRESSURE WILL PASS TO THE NORTHWEST OF NEW
ENGLAND. THIS WILL RESULT IN A PERIOD OF SNOW AND RAIN AS WARM
ADVECTION/OVERUNNING TAKE PLACE. SNOW AMOUNTS ARE EXPECTED TO BE
MINIMAL AND CONFINED TO THE NORTH AND WEST AS THE PRECIPITATION
IS EXPECTED TO QUICKLY CHANGE TO RAIN. ANOTHER PERIOD OF RAIN WITH
SOME SNOW MIXED IS EXPECTED FRIDAY AS LOW PRESSURE DEVELOPS ACROSS
NEW ENGLAND.
&&
.LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
LOW PRESSURE MOVING ACROSS QUEBEC WILL PUSH A WEAK FRONT ACROSS
THE STATE FRI EVENING. A FEW SHWRS ARE EXPECTED IN ASSOCIATION,
THOUGH BY THE 00Z SAT MUCH OF THE PRECIP MAY BE OVER FAR ERN & NRN
MAINE, DEPARTING INTO NEW BRUNSWICK AS THE NIGHT PROGRESSES. AN
UPR RIDGE AND WEAK SFC HIGH THEN BUILDS ACROSS THE AREA, ALLOWING
FOR CLEARING SAT INTO AT LEAST SUN AM.
BEYOND THEN, MODEL AGREEMENT BREAKS DOWN. WHILE BOTH THE GFS AND
ECMWF WOULD AGREE ON SOME MORE ACTIVE WEATHER MONDAY INTO TUESDAY,
THEY HAVE COMPLETELY DIFFERENT SOLUTIONS. THE GFS SHOWS ONE VERY
POTENT SFC LOW DRIVEN BY A DEEP UPR TROF MOVING INTO ERN CANADA
AND PUSHING A STRONG FRONT ACROSS THE STATE ON MON. THIS SOLUTION
WOULD BRING ABUNDANT RAINFALL LATE SUN NIGHT THRU MON AFTERNOON,
SWITCHING TO SNOW BEHIND THE FRONT AND LINGERING INTO TUE
AFTERNOON. THE ECMWF IS COMPLETELY DIFFERENT, SHOWING ONE LOW
DRIVEN BY A JET STREAK CROSSING THE CWA MON, AND A SECOND LOW
DRIVEN BY AN UPR TROF OR CUT-OFF MOVING ACROSS ON TUE. HOWEVER,
THE ECMWF HAS BEEN RATHER VARIABLE RUN-TO- RUN, WHILE THE GFS HAS
BEEN A BIT MORE CONSISTENT. GIVEN THIS, AND THE FACT THAT THE
CANADIAN APPEARS CLOSER TO THE GFS, ANY EDITS MADE SUN THRU TUE
WERE SKEWED TOWARD THE GFS SOLUTION.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR LATE THIS EVENING. A LLVL DECK, MVFR AND POSSIBLY
EVEN IFR COULD DEVELOP AFTER MIDNIGHT AND LINGER INTO WED MORNING
AS LIGHT ESE FLOW DEVELOPS. THIS DECK LOOKS LIKE IT WILL SET UP E
OF THE BGR AND BHB TERMINALS.
SHORT TERM: MVFR/VFR CONDITIONS ARE EXPECTED THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM: THE WIND AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL
CRAFT ADVISORY LEVELS THROUGH WEDNESDAY.
SHORT TERM: HAVE USED A BLEND OF THE NAM12 AND GFS40 FOR WINDS. A
SOUTHERLY FETCH WILL DEVELOP FROM THE GULF OF MAINE SOUTHWARD
THURSDAY WITH WAVE HEIGHTS BUILDING TO AROUND 6 FEET/7 SECONDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...BLOOMER
SHORT TERM...NORCROSS
LONG TERM...NORCROSS
AVIATION...BLOOMER/NORCROSS
MARINE...BLOOMER/NORCROSS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1123 PM EST TUE DEC 8 2015
.SYNOPSIS...
HIGH PRESSURE WILL REMAIN OVER THE AREA TONIGHT THROUGH
WEDNESDAY. THE HIGH WILL MOVE EAST WEDNESDAY NIGHT AS A WEAK
TROUGH OF LOW PRESSURE APPROACHES FRO THE WEEST. THIS TROUGH IS
EXPECTED TO CROSS THE REGION ON THURSDAY.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
11:30 PM UPDATE...MODIFIED SOME TEMPERATURES ACROSS THE NORTH
WHERE SOME VALLEYS HAVE BEGUN TO COOL QUICKLY. ALSO MODIFIED
CLOUD COVER JUST A BIT WITH SOME MID AND HIGH CLOUDS BEGINNING TO
MOVE INTO WESTERN AREAS. RADAR SHOWS SOME WEAK ECHOES IN THE FAR
NORTHWEST SO INCLUDED A SLIGHT CHANCE OF SNOW SHOWERS IN THE
NORTHWEST. OTHERWISE, NO MAJOR CHANGES THIS HOUR.
PREVIOUS DISCUSSION... MAIN CHALLENGE THIS TERM AS HAS BEEN THE
PAST FEW DAYS WILL BE THE CLOUDS AND TEMPS.
SURFACE ANALYSIS SHOWED LOW PRES PASSING WELL SE OF THE AREA W/THE
MID AND HIGH CLOUDS ASSOCIATED W/IT STARING TO PULL OUT OF THE
DOWNEAST AND COASTAL AREA. FURTHER N AND W, SATELLITE IMAGERY
SHOWED SOME CLOUDS AROUND AS WEAK UPPER IMPULSE PASSES BY TO THE N
DESPITE HIGH PRES AT THE SURFACE. DOWNEAST AND THE COAST SHOULD
REMAIN MOSTLY CLEAR OVERNIGHT W/HIGH PRES PULLING E. THOSE CLOUDS
ACROSS THE NORTHERN SECTIONS WILL SLOWLY ERODE THIS EVENING, BUT
MORE CLOUDS ARE FORECAST TO SET UP LATER TONIGHT AS A LIGHT ESE
FLOW SETS UP ALLOWING FOR MOISTURE TO GET TRAPPED UNDER THE
INVERSION. THE HRRR DOING WELL W/CURRENT SETUP AND SHOWED THE LLVL
MOISTURE SETTING UP OVER EASTERN AND NORTHERN SECTIONS AFTER
MIDNIGHT. TEMPS WILL VARY OVERNIGHT DEPENDENT ON THE CLOUDS. THIS
WILL MAKE IT FOR A TOUGHT FORECAST. DECIDED TO GO W/UPPER TEENS TO
LOWER 20S ACROSS THE NORTHERN 1/2 OF THE CWA W/THE COLDEST TEMPS
IN THE LOW LYING AREAS AND NEAR RIVER VALLEYS. STAYED W/MID-UPPER
20S DOWNEAST AND THE COAST. THIS WILL NEED TO BE MONITORED AS SOME
OF THE LOW LYING AREAS IN THIS REGION COULD GO COLDER DEPENDING ON
LONGEVITY OF THE CLEARING. PATCHY FOG POSSIBLE ESPECIALLY ALONG
THE RIVER VALLEYS.
LOW CLOUDS WILL TAKE SOME TIME TO ERODE WEDNESDAY MORNING W/THE
WEAK SE FLOW IN PLACE. DIRUNAL EFFECTS SHOULD AID IN ALLOWING FOR
THE CLOUD DECK TO LIFT AND DISSIPATE SOME W/SUNSHINE. DAYTIME
TEMPERATURES WILL BE A BIT ABOVE NORMAL FOR EARLY DECEMBER.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH FRIDAY/...
HIGH PRESSURE WILL MOVE OFF THE COAST WEDNESDAY NIGHT WHILE AT
THE SAME TIME LOW PRESSURE WILL PASS TO THE NORTHWEST OF NEW
ENGLAND. THIS WILL RESULT IN A PERIOD OF SNOW AND RAIN AS WARM
ADVECTION/OVERUNNING TAKE PLACE. SNOW AMOUNTS ARE EXPECTED TO BE
MINIMAL AND CONFINED TO THE NORTH AND WEST AS THE PRECIPITATION
IS EXPECTED TO QUICKLY CHANGE TO RAIN. ANOTHER PERIOD OF RAIN WITH
SOME SNOW MIXED IS EXPECTED FRIDAY AS LOW PRESSURE DEVELOPS ACROSS
NEW ENGLAND.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
LOW PRESSURE MOVING ACROSS QUEBEC WILL PUSH A WEAK FRONT ACROSS
THE STATE FRI EVENING. A FEW SHWRS ARE EXPECTED IN ASSOCIATION,
THOUGH BY THE 00Z SAT MUCH OF THE PRECIP MAY BE OVER FAR ERN & NRN
MAINE, DEPARTING INTO NEW BRUNSWICK AS THE NIGHT PROGRESSES. AN
UPR RIDGE AND WEAK SFC HIGH THEN BUILDS ACROSS THE AREA, ALLOWING
FOR CLEARING SAT INTO AT LEAST SUN AM.
BEYOND THEN, MODEL AGREEMENT BREAKS DOWN. WHILE BOTH THE GFS AND
ECMWF WOULD AGREE ON SOME MORE ACTIVE WEATHER MONDAY INTO TUESDAY,
THEY HAVE COMPLETELY DIFFERENT SOLUTIONS. THE GFS SHOWS ONE VERY
POTENT SFC LOW DRIVEN BY A DEEP UPR TROF MOVING INTO ERN CANADA
AND PUSHING A STRONG FRONT ACROSS THE STATE ON MON. THIS SOLUTION
WOULD BRING ABUNDANT RAINFALL LATE SUN NIGHT THRU MON AFTERNOON,
SWITCHING TO SNOW BEHIND THE FRONT AND LINGERING INTO TUE
AFTERNOON. THE ECMWF IS COMPLETELY DIFFERENT, SHOWING ONE LOW
DRIVEN BY A JET STREAK CROSSING THE CWA MON, AND A SECOND LOW
DRIVEN BY AN UPR TROF OR CUT-OFF MOVING ACROSS ON TUE. HOWEVER,
THE ECMWF HAS BEEN RATHER VARIABLE RUN-TO- RUN, WHILE THE GFS HAS
BEEN A BIT MORE CONSISTENT. GIVEN THIS, AND THE FACT THAT THE
CANADIAN APPEARS CLOSER TO THE GFS, ANY EDITS MADE SUN THRU TUE
WERE SKEWED TOWARD THE GFS SOLUTION.
&&
.AVIATION /06Z WEDNESDAY THROUGH SUNDAY/...
NEAR TERM: VFR LATE THIS EVENING. A LLVL DECK, MVFR AND POSSIBLY
EVEN IFR COULD DEVELOP AFTER MIDNIGHT AND LINGER INTO WED MORNING
AS LIGHT ESE FLOW DEVELOPS. THIS DECK LOOKS LIKE IT WILL SET UP E
OF THE BGR AND BHB TERMINALS.
SHORT TERM: MVFR/VFR CONDITIONS ARE EXPECTED THURSDAY AND FRIDAY.
&&
.MARINE...
NEAR TERM: THE WIND AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL
CRAFT ADVISORY LEVELS THROUGH WEDNESDAY.
SHORT TERM: HAVE USED A BLEND OF THE NAM12 AND GFS40 FOR WINDS. A
SOUTHERLY FETCH WILL DEVELOP FROM THE GULF OF MAINE SOUTHWARD
THURSDAY WITH WAVE HEIGHTS BUILDING TO AROUND 6 FEET/7 SECONDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...CB/HEWITT/MCB
SHORT TERM...MIGNONE
LONG TERM...KREDENSOR
AVIATION...CB/HEWITT/MIGNONE
MARINE...CB/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
349 AM EST WED DEC 9 2015
.SYNOPSIS...
HIGH PRESSURE REMAINS OVER THE REGION THROUGH MIDDAY. A WEAK LOW
PRESSURE SYSTEM SWINGS THROUGH THE AREA TONIGHT AND EARLY
THURSDAY. HIGH PRESSURE BUILDS OVER THE AREA AGAIN BY FRIDAY AND
REMAINS IN PLACE THROUGH THE COMING WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
CURRENT ANALYSIS INDICATING ~1023 MB SFC HIGH PRESSURE CENTERED
ALONG THE NC/SE VA COASTAL PLAIN. FARTHER WEST...AN ELONGATED
UPPER TROUGH STRETCHES FROM THE WESTERN GREAT LAKES SOUTH TO THE
LOWER MS VALLEY. CURRENT IR IMAGERY SHOWS SOME HIGHER CLOUDS
MOVING ACROSS NORTHERN PORTIONS OF THE FA...INCLUDING THE LOWER MD
EASTERN SHORE. OF GREATER CONCERN IS THE BLANKET OF LOW CLOUDS AND
FOG THAT CONTINUES TO EXPAND NORTH/EAST FROM SOUTH-CENTRAL VA
EARLY THIS MORNING. ALREADY NOTING DENSE FOG (VSBY <1/4 MILE) FOR
AREAS LIKE SOUTH HILL...EMPORIA...FARMVILLE...AND AHOSKIE. GOES-E
FOG PRODUCT IS PICKING UP ON THIS WELL THIS MORNING AND HAS BEEN
SHOWING THIS AREA OF FOG/STRATUS CONTINUING TO EXPAND. HRRR IS
KEYING ON IDEA OF FOG/STRATUS SPREADING NORTH AND EAST THRU
DAYBREAK AND ENCOMPASSING MUCH OF OUR VA/NC COUNTIES. THINK THAT
WIDESPREAD DENSE FOG WILL BE CONFINED PRIMARILY TO THE PIEDMONT
/SOUTH-CENTRAL VA COUNTIES WHERE DFA IS CURRENTLY IN EFFECT...BUT
WILL CONTINUE TO MONITOR TRENDS. CERTAINLY WILL BE A GLOOMY START
FOR MOST AREAS...UNTIL CLOUDS/FOG BURN OFF BY MID/LATE MORNING.
FOR THE REST OF TODAY...MODELS CONTINUE TO SHOW THE UPPER TROUGH
TO THE WEST TRACKING EAST ACROSS THE OH VALLEY/GREAT LAKES
REGIONS...WITH A WEAK COASTAL TROUGH MOVING ACROSS SE VA/NE NC
TONIGHT. HAVE CONTINUED WITH SLIGHT CHC TO LOW CHC POPS (20-30%) FOR
E/SE PORTIONS OF THE FA TONIGHT. OTW...VARIABLE CLOUDS-PARTLY
CLOUDY THRU TONIGHT. HIGHS TODAY IN THE MID/UPR 50S TO LOW 60S.
LOWS TONIGHT IN THE UPR 30S TO MID 40S.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY/...
DRY WX AND A MOSTLY SUNNY SKY RETURNS THU IN THE WAKE OF
AFOREMENTIONED SYSTEMS. HIGH TEMPS THU IN THE LOW/MID 60S. SFC
HIGH PRESSURE BECOMES ESTABLISHED NEAR THE SE COAST ON FRI AS A RIDGE
ALOFT BEGINS TO AMPLIFY INTO THE ERN CONUS. SWLY FLOW LEADS TO
CONTINUED WARMING UNDER A MAINLY CLEAR SKY. HIGH TEMPS FRI IN THE
MID/UPR 60S TO AROUND 70.
&&
.LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/...
UPPER LEVEL RIDGING SLOWLY BUILDS OVER THE MID ATLANTIC REGION FRI
NIGHT THROUGH SAT NIGHT WHILE SFC HIGH PRESSURE RESIDES OFF THE
SE/MID ATLANTIC STATES...RESULTING IN WARMING TEMPERATURES AND DRY
CONDITIONS DURING THIS TIMEFRAME. HIGHS IN THE MID-UPPER 60S SAT...
LOWS IN THE UPPER 40S FRI NIGHT AND LOWER 50S SAT NIGHT (AROUND
5 DEGREES WARMER AT THE BEACHES). 08/1200Z GFS SOLUTION COMING
MORE IN LINE WITH PREVIOUS 08/0000Z ECMWF MODEL RUN. IN GENERAL...
A DYNAMIC UPPER TROUGH EXITS THE DESERT SW AND INTO THE PLAINS AS
SFC LOW DEVELOPS FRI NIGHT AND STRENGTHENS INTO SAT NIGHT. HOWEVER...
THE LATEST 08/1200Z ECMWF HAS SUPPRESSED THE NEWD TRACK OF THE
UPPER/SFC LOWS INTO THE MIDWEST (VICE THE GFS) DUE TO ITS ATTEMPT
AT BECOMING MORE OF A CUTOFF LOW. THEREFORE THE EWD PROGRESSION OF
ITS RESULTANT STRONG SFC COLD FRONT/ONSET OF PRECIP HAS BEEN
DELAYED BY ABOUT 12-18 HOURS. AFTER COMPARING THE UPPER LEVEL JET
DYNAMICS...AM LEANING SLIGHTLY MORE TWD THE GFS MODEL SOLUTION.
THIS WOULD BRING THE STRENGTHENING SFC LOW INTO THE MIDWEST/GREAT
LAKES BY SUN MORNING AND THE STRONG SFC COLD FRONT ACROSS THE MID
ATLANTIC REGION LATE SUN NIGHT INTO THE FIRST HALF OF MON...QUICKLY
PUSHING OFFSHORE BY MON NIGHT. DUE TO LONG RANGE MODEL DISCREPANCIES
REGARDING TIMING AND PLACEMENT OF DYNAMIC FEATURES AND RAINFALL
COVERAGE...WENT WITH A MORE BROAD BRUSHED PRECIP FORECAST AND
CAPPED PRECIP WORDING TO CHANCE (NO HIGHER THAN 50 PERCENT) FOR
SUN NIGHT/MON. TEMPERATURES REMAIN WARM SUN/SUN NIGHT AHEAD OF THE
APPROACHING FRONT DUE TO WARM AIR ADVECTION AND BREEZY SW WINDS.
HIGHS IN THE MID-UPPER 60S. LOWS IN THE 50S. TEMPERATURES ON
MON/MON NIGHT WILL DEPEND ON HOW FAST PRECIP MOVES THROUGH THE
AREA AND HOW FAST COLD AIR ADVECTION CAN TAKE HOLD. HIGHS FOR NOW
IN THE LOW-MID 60S NW TO MID-UPPER 60S SE. WINDS SHOULD STAY BREEZY
MON NIGHT AND KEEP TEMPERATURES FROM BOTTOMING OUT TO THEIR FULLEST
POTENTIAL. EXPECT LOWS IN THE 40S (UPPER 30S POSSIBLE FAR NW COUNTIES).
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
WEAK HIGH PRESSURE IS CENTERED ALONG THE MID-ATLANTIC COAST EARLY
THIS MORNING. GOES SATELLITE PRODUCTS AND SURFACE OBS INDICATE A
LARGE AREA OF FOG ACROSS CENTRAL NC INTO S-CENTRAL VA.
PRESENTLY...THIS AREA OF FOG IS NOT DIRECTLY IMPACTING ANY TAF
SITES. HOWEVER...LOCALLY DENSE FOG HAS DEVELOPED AT PHF. HIGH-RES
DATA SUGGESTS THIS AREA OF FOG WILL EXPAND NE THROUGH THE EARLY
MORNING HOURS...AND TIME-LAGGED RAPID REFRESH DATA DEPICTS A HIGH
PROB OF IFR/LIFR DEVELOPING AT ALL TAF SITES THROUGH THE MORNING.
THE CURRENT FORECAST BEGINS IFR IN THE 08-10Z TIME-FRAME...WITH
POTENTIALLY WIDESPREAD DENSE FOG DEVELOPING BY 10-12Z. THE HIGH
GRADUALLY MOVES OFFSHORE TODAY...WHICH WILL ALLOW FOR AN 8-10KT
SOUTHERLY WIND TO DEVELOP BY ~16Z. VSBY SHOULD BE IMPROVING BY
THIS POINT...BUT THE SOUTHERLY WIND SHOULD FULLY RETURN CONDITIONS
TO VFR. A WEAK BOUNDARY WILL CROSS THE REGION LATE TONIGHT...BUT
MOISTURE IS LIMITED AND FORCING WILL BE WEAK. OTHERWISE...EXPECT
MAINLY VFR CONDITIONS THURSDAY THROUGH SUNDAY WITH HIGH PRESSURE
ACROSS THE REGION. THE ONLY EXCEPTION WILL BE THE POTENTIAL FOR
EARLY MORNING FOG.
&&
.MARINE...
BENIGN CONDITIONS ARE EXPECTED ACROSS THE MARINE AREA THROUGH
SUNDAY AS HIGH PRESSURE PREVAILS ACROSS THE REGION. WEAK HIGH
PRESSURE WILL GRADUALLY SLIDE OFFSHORE TODAY WITH A 5-10KT S WIND
DEVELOPING. A WEAK TROUGH WILL SLIDE ACROSS THE AREA LATE TONIGHT
INTO EARLY THURSDAY...PRODUCING NOT MUCH MORE THAN SUBTLE WIND
SHIFT...BEFORE S FLOW RESUMES BY AFTERNOON AS HIGH PRESSURE
DEVELOPS ALONG THE SOUTHEAST COAST. HIGH PRESSURE THEN EXPANDS AND
BECOMES ANCHORED OFF THE SOUTHEAST COAST THURSDAY NIGHT THROUGH
SUNDAY. THIS WILL PRODUCE SW FLOW AOB 15KT...WITH 2-3FT SEAS...AND
1- 2FT WAVES IN THE BAY. A COLD FRONT APPROACHES FROM THE W SUNDAY
NIGHT...WITH THE LATEST DATA BRINGING THE FRONT ACROSS THE COAST
MONDAY EVENING. THIS FRONT WILL BRING THE NEXT CHC OF SCA
CONDITIONS.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR NCZ012.
VA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR VAZ060-061-
065>068-079-080-087-088-092.
MARINE...NONE.
&&
$$
SYNOPSIS...JDM
NEAR TERM...JDM
SHORT TERM...JDM
LONG TERM...BMD
AVIATION...AJZ
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1034 PM CST TUE DEC 8 2015
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 342 PM CST TUE DEC 8 2015
GOOD PV ANOMALY WITH DRYING NOTED IN WATER VAPOR HAS HELPED FORCE
A NICE BAND OF LIGHT RAIN ACROSS ERN MN/WRN WI TODAY. NORTH OF
THE PV BOOT...THE COMBINATION OF FGEN IN THE H85-H7 LAYER AND
ISENTROPIC LIFT ON THE 295K SFC HAVE PROVIDED THE FORCING FOR THE
BAND OF RAIN WE SEE OUT THERE THIS AFTERNOON. THE HRRR HAS HAD A
PRETTY GOOD HANDLE ON THIS RAIN...SO FOLLOWED IT FOR SHIPPING
THIS BAND OF RAIN OUT OF THE EAST END OF THE MPX CWA BETWEEN 3Z
AND 6Z.
THIS WILL LIKELY BE IT FOR ANY MEANINGFUL PRECIP...THOUGH A FEW
SPRINKLES WILL BE POSSIBLE UNTIL THE MAIN UPPER TROUGH AND
ASSOCIATED SFC THROUGH CURRENTLY ENTERING WRN MN MOVE THROUGH.
HOWEVER...THIS WAVE LOOKS TO LACK DEEP MOISTURE LIKE THE LEAD WAVE
HAS...SO CONCENTRATED ANY MENTIONABLE POPS ON THE ERN WAVE.
FOR TONIGHT...THE MAIN PLAYER TO WHAT WILL HAPPEN WITH
TEMPERATURES AND THE POTENTIAL FOR FOG/STRATUS WILL BE THE NARROW
STRIP OF CLEARING THAT IS STRADDLING THE WRN DAKOTAS BORDER. THIS
CLEARING WILL WORK FROM WEST TO EAST ACROSS THE MPX AREA
TONIGHT. DEPENDING ON WHEN THE CLEARING ARRIVES AND HOW LONG IT
PERSISTS...COULD EASILY SEE LOWS A FEW DEGREES COOLER THAN WHAT
WE CURRENTLY HAVE...ESPECIALLY ACROSS CENTRAL MN. THERE WILL ALSO
BE THE POTENTIAL TO DEVELOP FOG/LOW STRATUS. HOWEVER...WITH SFC
WINDS EXPECTED TO REMAIN UP IN THE 4-8KT RANGE BEHIND THE
TROUGH...LIKELY MEANS OUR MAIN ISSUE FOR TONIGHT WOULD BE THE
POTENTIAL FOR VERY LOW STRATUS AS OPPOSED TO FOG. THE HRRR
DEVELOPS LOW STRATUS/FOG LATE TONIGHT OVER ERN MN/WRN WI...WHICH
GIVEN THE CURRENT RAIN WOULD MAKE THE MOST SENSE FOR SEEING
STRATUS/FOG IF WE ARE GOING TO SEE IT.
FOR WEDNESDAY...ZONAL FLOW ALOFT WILL MEAN MORE MID/UPPER LEVEL
CLOUDS...BUT ALSO THE RETURN OF VERY MILD AIR FROM THE CENTRAL
PLAINS. BOUNDARY LAYER WINDS TOMORROW WILL BE FROM THE SW...WHICH
IS A FAVORABLE WARMING DIRECTION. AS A RESULT...BOOSTED HIGHS
SEVERAL DEGREES DOWNSTREAM OF THE BUFFALO RIDGE...WHERE WE ARE NOW
ANTICIPATING HIGHS TO REACH INTO THE LOW TO MID 50S...WITH HIGHS
AROUND 40 WITH THE REMNANT SNOWPACK OVER CENTRAL MN AND MID/UPPER
40S ELSEWHERE...THOUGH THIS COULD BE WARMER OUTSIDE OF THE REMNANT
SNOW COVER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 342 PM CST TUE DEC 8 2015
THE PATTERN WILL CONTINUE BECOMING MORE ACTIVE DURING THE LONG
TERM. THE FIRST IN A SERIES OF SYSTEMS TO WATCH WILL BE TRACKING
EASTWARD ALONG THE CANADIAN BORDER WEDNESDAY NIGHT AND THURSDAY.
MODELS REMAIN IN FAIRLY GOOD AGREEMENT WITH THIS SYSTEM...WITH
THE EXCEPTION OF THE EURO WHICH CONTINUES TO TRACK ON THE SOUTHERN
EDGE OF THE ENVELOPE. THE MAJORITY OF THE CWA SHOULD BE
DRY...WITH PRECIPITATION LIKELY TO OCCUR ALONG AND NORTH OF THE
STORM TRACK. REDUCED POPS SOME...BUT MAINTAINED AT LEAST SOME
MENTIONABLE POPS ACROSS THE ENTIRE CWA. HIGHEST POPS ARE CONFINED
TO CENTRAL MN WHERE HIGH CHC OR LOW END LIKELIES CONTINUE. TO THE
SOUTH OF THE TRACK...THE DRY SLOT SHOULD HELP CLEAR THE CLOUDS
THURSDAY AFTERNOON ACROSS SRN MN AND WRN WI. STRONGEST CAA WILL
LAG BEHIND THE SYSTEM...AND IT COULD GET RATHER MILD DEPENDING ON
THE AMOUNT OF SUN. CANNOT RULE OUT LOWER 50S ACROSS SRN MN AND
INTO WRN WI. WINDS WILL BE QUITE GUSTY WITH THE PASSAGE OF THE
NEGATIVELY TILTED TROUGH...PARTICULARLY IF THE BOUNDARY LAYER
DESTABILIZES WITH EITHER STRONGER CAA ALOFT...OR HEATING WITH
SUN.
THE DEVELOPING TROUGH ACROSS THE WESTERN U.S. THURSDAY INTO
FRIDAY WILL PLAY A BIG ROLE IN THE REST OF THE LONG TERM FORECAST.
ENERGY WILL BEGIN EJECTING OUT IN PIECES THURSDAY NIGHT WITH A
LEADING WAVE ARRIVING LATE FRIDAY. THIS MAY BRING A SMALL CHANCE
FOR PRECIPITATION...BUT IT DOES NOT HAVE THE TROPICAL MOISTURE IT
WOULD NEED TO PRODUCE ANYTHING SIGNIFICANT. THE MAIN PLAYER WILL
ROUND THE BASE OF THE TROUGH OVER THE SOUTHWESTERN U.S. SATURDAY.
THERE ARE REALLY ONLY TWO LIKELY SCENARIOS THAT WILL PLAY OUT. THE
FIRST ONE IS A PHASED SYSTEM WITH THE NORTHERN STREAM THAT RESULTS
IN A ROBUST SURFACE CYCLONE WHICH TRACKS NORTH NORTHEAST FROM THE
SOUTHERN PLAINS INTO THE WESTERN GREAT LAKES. THIS SCENARIO WOULD
BRING A LOT OF MOISTURE WITH IT NORTHWARD...WITH A MATURE
EXTRATROPICAL CYCLONE BY SUNDAY MORNING SOMEWHERE OVER THE UPPER
MISSISSIPPI VALLEY. SUCH A TRACK IS A LIKELY HEAVY SNOW PRODUCER
FOR US. THE OPERATIONAL GFS AND MANY OF ITS ENSEMBLES...THE
CANADIAN...AND THE FORMER RUNS OF THE ECMWF INDICATED THIS AS A
FAVORED OPTION. THE OTHER SCENARIO IS WHAT THE NEW ECMWF HAS
REVERTED TO AND FEATURES THE UPPER LOW CLOSING OFF FROM THE
NORTHERN STREAM WHICH RESULTS IN A LESS DEVELOPED...SLOW MOVING
SOUTHERN CYCLONE AND LITTLE OR NO PRECIPITATION FOR US. AT THIS
POINT EITHER SCENARIO IS POSSIBLE...BUT PREFER THE FIRST SOLUTION
WHICH HAD STRONG SUPPORT OVERNIGHT. WILL AWAIT FOR FUTURE RUNS TO
DETERMINE ANY MEANINGFUL TREND.
FOLLOWING THE PASSAGE OF THAT SYSTEM IS ANOTHER ORIGINATING FROM
THE NEXT TROUGH OVER THE WESTERN U.S. MODEL CONSISTENCY HAS NOT
BEEN THE BEST WITH THIS ONE...LIKELY DUE TO ERRORS ASSOCIATED WITH
ITS PREDECESSOR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1033 PM CST TUE DEC 8 2015
GIVEN THE RAIN AND LIGHT WIND...WE ARE SEEING A FEW POCKETS OF
FOG IN EASTERN MN AND WESTERN WI. WE ARE A LITTLE CONCERNED THAT
CLEARING COULD ALLOW THE FOG TO EXPAND LATE TONIGHT. WE ALSO
EXPECT A SLIGHT INCREASE IN WIND...WHICH WOULD HELP INHIBIT FOG
FORMATION. GIVEN THE UNCERTAINTY...WE`LL HAVE TO MONITOR THE
VISIBILITY TRENDS AND UPDATE ACCORDINGLY. WE DO THINK THE FOG WILL
GRADUALLY PUSH EAST WITH TIME...SO KRNH COULD ACTUALLY CLEAR
BEFORE SUNRISE.
KMSP...
WE INCLUDED A TEMPO FOR LIGHT FOG EARLY TONIGHT WITH MVFR
VISIBILITY. THIS MIGHT NOT HAPPEN. THERE IS A LITTLE WIND OUT
THERE AND THE AIRPORT IS TYPICALLY HARD TO FOG IN...BUT THE
HUMIDITY IS CLOSE TO 100% THIS EVENING AND THE WIND HAS BEEN NEAR
CALM AT TIMES...SO WHEN THE SKY CLEARS IT WOULD ONLY TAKE A SMALL
AMOUNT OF COOLING TO START FORMING FOG. THE GOOD NEWS...IF IT DOES
FORM...IT SHOULD MOVE ABOUT BEFORE THE MORNING RUSH.
/OUTLOOK FOR KMSP/
THU...VFR WITH MVFR/-RA POSSIBLE. WIND W AT 10G20 KTS.
FRI...VFR. WINDS ESE 5-10 KTS.
SAT...VFR WITH MVFR POSSIBLE. WINDS NNW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...BORGHOFF
AVIATION...CLF
AREA FORECAST DISCUSSION
NWS RALEIGH NC
320 PM EST WED DEC 9 2015
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL TRACK EASTWARD ACROSS
THE REGION TONIGHT. ZONAL FLOW ALOFT ON THURSDAY WILL GRADUALLY
TRANSITION TO SOUTHWEST FLOW ALOFT OVER THE WEEKEND AS AN UPPER
LEVEL RIDGE BUILDS ALONG OR JUST OFFSHORE THE SOUTHEAST COAST.
&&
.NEAR TERM /TONIGHT/...
AS OF 255 PM WEDNESDAY...
A PROGRESSIVE SHORTWAVE TROUGH EXTENDING FROM THE GREAT LAKES SOUTH
INTO THE TN VALLEY WILL TRACK EAST ACROSS THE CAROLINAS AND MID-
ATLANTIC THIS EVENING. LOW-LEVEL FLOW ALONG THE COAST WILL BACK AND
STRENGTHEN WITH THE APPROACH OF 40-60M SYNOPTIC H5 FALLS. THE
RESULTANT WARM MOIST AIR ADVECTION COUPLED WITH LIFT WITHIN THE
RIGHT ENTRANCE REGION OF A 70KT JET MAXIMA WILL SUPPORT A CHANCE OF
SHALLOW CONVECTION/SHOWERS BREAKING OUT ACROSS THE SC/NC COASTAL
PLAIN THIS AFTERNOON AND EVENING...WITH INCREASINGLY AGITATED
CUMULUS FIELD CURRENTLY OVER COASTAL CAROLINA EVIDENCE OF THE PRE-
CONVECTIVE INITIATION CURRENTLY UNDERWAY.
WILL MAINTAIN SMALL CHANCE POPS ALONG AND EAST OF THE I-95
CORRIDOR...TAPERING OFF TO SLIGHT CHANCE EXTENDING WEST TO THE HWY 1
CORRIDOR AND EXITING THE EASTERN CORRIDOR ~06Z.
A GRADUAL WEST-EAST CLEARING TREND AFTER MIDNIGHT MAY ALLOW DENSE
FOG TO DEVELOP ONCE AGAIN THU MORNING. HRRR AND RAP MODEL FIELDS ARE
NOT AS APPARENT AS LAST NIGHT AND AS SUCH CONFIDENCE IS TOO LOW
AT THIS TIME TO ISSUE A DENSE FOG ADVISORY.
LOWS OVERNIGHT IN THE UPPER 30S TO LOWER 40S NORTHWEST PIEDMONT TO
MID/UPPER 40S EAST.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 250 PM WEDNESDAY...
IN THE WAKE OF THE SHORTWAVE TROUGH PASSAGE TONIGHT...ZONAL FLOW
ALOFT WILL BECOME ESTABLISHED ON THURSDAY. SHORTWAVE ENERGY EMBEDDED
IN THE ZONAL FLOW ALOFT MAY SUPPORT PERIODS OF BROKEN HIGH CLOUDS.
OTHERWISE...AFTER MORNING FOG DISPERSES EXPECT PARTLY TO MOSTLY
SUNNY SKIES. HIGHS IN THE LOWER TO MID 60S. LOWS THU NIGHT
LOWER/MIDDLE 40S.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
AS OF 315 PM THURSDAY...
FRIDAY THROUGH SUNDAY: MID/UPPER LEVEL FLOW PATTERN WILL BECOME MORE
AMPLIFIED AGAIN DURING THIS PERIOD (THROUGH THE WEEKEND)... WITH
TROUGHING ACROSS THE WESTERN U.S... WITH A BUILDING RIDGE ACROSS THE
EAST COAST. MEANWHILE... SURFACE HIGH PRESSURE WILL LINGER ALONG/OFF
THE SOUTHEAST U.S. COAST. THIS WILL RESULT IN A WARM AND DRY PERIOD
FOR CENTRAL NC... WITH WELL ABOVE NORMAL TEMPS. HIGH TEMPS ARE
EXPECTED TO RANGE FROM THE UPPER 60 TO LOWER 70S FRIDAY TO THE LOWER
TO MID 70S DURING THE WEEKEND. LOWS WILL FOLLOW A SIMILAR TREND...
WELL ABOVE NORMAL... GENERALLY RANGING FROM THE MID 40S TO THE LOWER
50S.
SUNDAY NIGHT THROUGH WEDNESDAY: THE NEXT SYSTEM WILL APPROACH FROM
THE WEST ON SUNDAY NIGHT. HOWEVER... THE MAIN ENERGY WITH THE SYSTEM
IS EXPECTED TO PASS WELL TO THE NORTH... WITH A TRAILING COLD FRONT
MOVING ACROSS THE AREA ON MONDAY/MONDAY EVENING WITH A CHANCE OF
SHOWERS GENERALLY ALONG AND AHEAD OF THE FRONT. DRY AND COOLER
WEATHER IS EXPECTED FOR TUESDAY AND WEDNESDAY BEHIND THE FRONT...
THOUGH HIGH TEMPS ARE STILL EXPECTED TO REMAIN ABOVE NORMAL...
GENERALLY IN THE 60S. HIGHS ON MONDAY WILL BE WARM AGAIN...
GENERALLY RANGING FROM THE MID 60S TO THE LOWER TO MID 70S.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 120 PM WEDNESDAY...
24-HR TAF PERIOD:
WAA IN ADVANCE OF AN UPPER LEVEL TROUGH THAT WILL MOVE EAST THROUGH
THE AREA THIS EVENING WILL SUPPORT SCATTERED LIGHT RAIN SHOWERS
ACROSS OVER THE SANDHILLS AND COASTAL PLAIN BETWEEN 21Z TO 06Z.
A BRIEF PERIOD OF MVFR CEILINGS IS POSSIBLE AT KFAY AND KRWI AS THE
SHOWERS MOVE THROUGH THE AREA.
GRADUAL CLEARING FROM WEST-EAST AFTER MIDNIGHT MAY ALLOW DENSE FOG
TO DEVELOP ACROSS PORTIONS OF CENTRAL NC ONCE AGAIN BETWEEN 06 TO
14Z THURSDAY. ANY FOG THAT DEVELOPS SHOULD LIFT TO VFR BY 15Z.
LOOKING AHEAD: ASIDE FROM A POTENTIAL FOR SEVERAL HOURS OF SUB-VFR
FOG AND/OR STRATUS... EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE
WEEKEND. A COLD FRONT WILL MOVE THROUGH THE AREA EARLY MONDAY.
SHOWERS AND A BRIEF PERIOD PERIOD OF SUB-VFR CONDITIONS MAY
ACCOMPANY THE FRONT.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES FOR SAT-SUN DECEMBER 12-13:
RALEIGH AREA... 12/12... 79 (2007) AND 12/13... 77 (1927).
GREENSBORO AREA... 12/12... 77 (2007) AND 12/13... 76 (1927).
FAYETTEVILLE AREA... 12/12... 81 (1931) AND 12/13... 81 (1927).
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...77
AVIATION...CBL
CLIMATE...BADGETT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
255 PM EST WED DEC 9 2015
.SYNOPSIS...AN UPPER LEVEL DISTURBANCE WILL TRACK EASTWARD ACROSS
THE REGION TONIGHT. ZONAL FLOW ALOFT ON THURSDAY WILL GRADUALLY
TRANSITION TO SOUTHWEST FLOW ALOFT OVER THE WEEKEND AS AN UPPER
LEVEL RIDGE BUILDS ALONG OR JUST OFFSHORE THE SOUTHEAST COAST.
&&
.NEAR TERM /TONIGHT/...
AS OF 255 PM WEDNESDAY...
A PROGRESSIVE SHORTWAVE TROUGH EXTENDING FROM THE GREAT LAKES SOUTH
INTO THE TN VALLEY WILL TRACK EAST ACROSS THE CAROLINAS AND MID-
ATLANTIC THIS EVENING. LOW-LEVEL FLOW ALONG THE COAST WILL BACK AND
STRENGTHEN WITH THE APPROACH OF 40-60M SYNOPTIC H5 FALLS. THE
RESULTANT WARM MOIST AIR ADVECTION COUPLED WITH LIFT WITHIN THE
RIGHT ENTRANCE REGION OF A 70KT JET MAXIMA WILL SUPPORT A CHANCE OF
SHALLOW CONVECTION/SHOWERS BREAKING OUT ACROSS THE SC/NC COASTAL
PLAIN THIS AFTERNOON AND EVENING...WITH INCREASINGLY AGITATED
CUMULUS FIELD CURRENTLY OVER COASTAL CAROLINA EVIDENCE OF THE PRE-
CONVECTIVE INITIATION CURRENTLY UNDERWAY.
WILL MAINTAIN SMALL CHANCE POPS ALONG AND EAST OF THE I-95
CORRIDOR...TAPERING OFF TO SLIGHT CHANCE EXTENDING WEST TO THE HWY 1
CORRIDOR AND EXITING THE EASTERN CORRIDOR ~06Z.
A GRADUAL WEST-EAST CLEARING TREND AFTER MIDNIGHT MAY ALLOW DENSE
FOG TO DEVELOP ONCE AGAIN THU MORNING. HRRR AND RAP MODEL FIELDS ARE
NOT AS APPARENT AS LAST NIGHT AND AS SUCH CONFIDENCE IS TOO LOW
AT THIS TIME TO ISSUE A DENSE FOG ADVISORY.
LOWS OVERNIGHT IN THE UPPER 30S TO LOWER 40S NORTHWEST PIEDMONT TO
MID/UPPER 40S EAST.
&&
.SHORT TERM /THURSDAY AND THURSDAY NIGHT/...
AS OF 250 PM WEDNESDAY...
IN THE WAKE OF THE SHORTWAVE TROUGH PASSAGE TONIGHT...ZONAL FLOW
ALOFT WILL BECOME ESTABLISHED ON THURSDAY. SHORTWAVE ENERGY EMBEDDED
IN THE ZONAL FLOW ALOFT MAY SUPPORT PERIODS OF BROKEN HIGH CLOUDS.
OTHERWISE...AFTER MORNING FOG DISPERSES EXPECT PARTLY TO MOSTLY
SUNNY SKIES. HIGHS IN THE LOWER TO MID 60S. LOWS THU NIGHT
LOWER/MIDDLE 40S.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
AS OF 245 AM WEDNESDAY...
A WARM DRY PERIOD IS EXPECTED WITH HIGH CONFIDENCE FRIDAY THROUGH
THE WEEKEND. LOWS WILL WARM FROM THE 40S FRIDAY INTO THE LOWER TO
MID 50S SUNDAY AND MONDAY. HIGHS WILL REACH THE LOW TO MID 70S IN
MOST AREAS ESPECIALLY OVER THE WEEKEND. THERE IS ONLY A SLIGHT
CHANCE THAT DAILY RECORD HIGHS MAY BE CHALLENGED BOTH DAYS. SEE THE
CLIMATE SECTION BELOW.
THE NEXT CHANCE OF SHOWERS SHOULD BE SUNDAY NIGHT INTO MONDAY WITH
THE APPROACH OF OUR NEXT FRONT. THE MAIN STORM TRACK WILL BE WELL
NORTHWEST OF THE REGION... WITH JUST THE TRAILING COLD FRONT
CROSSING OUR AREA ON SUNDAY NIGHT/MONDAY (OR MONDAY NIGHT/TUESDAY).
BEHIND THE FRONT...COOLER AND DRIER CONDITIONS ARE EXPECTED ON
TUESDAY. TEMPS WILL BE TEMPERED SOME (COMPARED TO PREVIOUS DAYS) ON
MONDAY GIVEN THE CLOUDS AND RAIN...WITH LOW TO UPPER 60S EXPECTED.
THEN UPPER 50S TO LOWER 60S ARE EXPECTED ON TUESDAY BEHIND THE
FRONT. OVERNIGHT LOWS WILL RETURN TO THE UPPER 30S AND 40S BY EARLY
NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
AS OF 120 PM WEDNESDAY...
24-HR TAF PERIOD:
WAA IN ADVANCE OF AN UPPER LEVEL TROUGH THAT WILL MOVE EAST THROUGH
THE AREA THIS EVENING WILL SUPPORT SCATTERED LIGHT RAIN SHOWERS
ACROSS OVER THE SANDHILLS AND COASTAL PLAIN BETWEEN 21Z TO 06Z.
A BRIEF PERIOD OF MVFR CEILINGS IS POSSIBLE AT KFAY AND KRWI AS THE
SHOWERS MOVE THROUGH THE AREA.
GRADUAL CLEARING FROM WEST-EAST AFTER MIDNIGHT MAY ALLOW DENSE FOG
TO DEVELOP ACROSS PORTIONS OF CENTRAL NC ONCE AGAIN BETWEEN 06 TO
14Z THURSDAY. ANY FOG THAT DEVELOPS SHOULD LIFT TO VFR BY 15Z.
LOOKING AHEAD: ASIDE FROM A POTENTIAL FOR SEVERAL HOURS OF SUB-VFR
FOG AND/OR STRATUS... EXPECT VFR CONDITIONS TO PREVAIL THROUGH THE
WEEKEND. A COLD FRONT WILL MOVE THROUGH THE AREA EARLY MONDAY.
SHOWERS AND A BRIEF PERIOD PERIOD OF SUB-VFR CONDITIONS MAY
ACCOMPANY THE FRONT.
&&
.CLIMATE...
RECORD HIGH TEMPERATURES FOR SAT-SUN DECEMBER 12-13:
RALEIGH AREA... 12/12... 79 (2007) AND 12/13... 77 (1927).
GREENSBORO AREA... 12/12... 77 (2007) AND 12/13... 76 (1927).
FAYETTEVILLE AREA... 12/12... 81 (1931) AND 12/13... 81 (1927).
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...CBL
SHORT TERM...CBL
LONG TERM...BADGETT
AVIATION...CBL
CLIMATE...BADGETT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1238 AM CST WED DEC 9 2015
.UPDATE...
ISSUED AT 1232 AM CST WED DEC 9 2015
A FEW MINOR UPDATES WERE MADE TO PRECIP CHANCES FOR THIS UPDATE.
THE LATEST SHORT-TERM MODELS INDICATE ANY AREA OF SCATTERED RAIN
SHOWERS OVER CANADA WILL CONTINUE TO DEVELOP AND PUSH ACROSS
WESTERN AND CENTRAL NORTH DAKOTA THROUGH THE OVERNIGHT AND EARLY
MORNING HOURS. RADAR INDICATES RECENT DEVELOPMENT ACROSS WESTERN
AND NORTH CENTRAL NORTH DAKOTA. THEREFORE...INCREASED COVERAGE OF
PRECIP CHANCES.
UPDATE ISSUED AT 925 PM CST TUE DEC 8 2015
BASED ON THE LATEST RADAR INFORMATION AND CONSSHORT GUIDANCE HAVE
ADJUSTED THE POPS A BIT FURTHER SOUTH. HRRR STILL KEEPS THE PRECIP
FURTHER NORTH THAN CONSSHORT BUT WILL TREND CLOSER TO CONSSHORT.
UPDATE ISSUED AT 627 PM CST TUE DEC 8 2015
WILL CONTINUE TO FOLLOW THE LATEST HRRR MODEL THAT KEEPS THE
PRECIP ACROSS THE NORTH TONIGHT. THE CONSSHORT GUIDANCE LOOKS A
BIT TOO FAR SOUTH AND TOO WET AT THIS TIME. LIKE THE CURRENT POPS
WITH JUST A SLIGHT CHANCE OF RAIN THIS EVENING BUT A THREAT FRO
SOME FREEZING RAIN NORTH CENTRAL...OVER THE TURTLE MOUNTAINS
TOWARDS MIDNIGHT. OTHERWISE UPDATED THE CURRENT CONDITIONS.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 250 PM CST TUE DEC 8 2015
VERY WARM WEATHER IS EXPECTED WEDNESDAY IN MEAN ZONAL FLOW ALOFT.
ANOTHER BATCH OF VERY MILD AIR ORIGINATING OVER THE PACIFIC OCEAN
WILL SURGE EASTWARD INTO THE NORTHERN PLAINS BY WEDNESDAY AHEAD OF
A 500-MB SHORTWAVE CRASHING INTO THE NORTHERN ROCKIES. THE 12 UTC
MODEL GUIDANCE CALLS FOR 850-MB TEMPERATURES TO RISE INTO THE +10
TO +12 C RANGE OVER SOUTHWESTERN ND BY WEDNESDAY...AND WITH MEAN
WESTERLY LOW-LEVEL THROUGH AT LEAST EARLY AFTERNOON...HIGHS WILL
SOAR TO NEAR-RECORD LEVELS IN MANY AREAS. WE UTILIZED 12 UTC BIAS-
CORRECTED MOS TO BUILD THE HIGH TEMPERATURE FORECAST WEDNESDAY...
WHICH CALLS FOR HIGHS RANGING FROM 50 AT JAMESTOWN TO THE LOWER
60S IN SOUTHWESTERN ND. THE CURRENT DAILY RECORD HIGHS OF 56 F AT
WILLISTON AND 60 F AT DICKINSON COULD BE TIED OR BROKEN. EXPECTED
HIGH-LEVEL CLOUDS AND A LATE-DAY TURN TOWARD MORE SOUTHERLY WINDS
IN THE BOUNDARY LAYER KEPT US FROM ADVERTISING EVEN WARMER HIGHS.
OTHERWISE...WE DO HAVE A SLIGHT CHANCE OF LIGHT RAIN OR FREEZING
RAIN OVER NORTHWEST AND NORTH CENTRAL ND AFTER 06 UTC TONIGHT AND
CONTINUING INTO EARLY WEDNESDAY MORNING. THAT MENTION IS TIED TO
THE APPROACHING MID-LEVEL WARM FRONT...BUT THERE IS LITTLE SIGNAL
OF MOISTURE IN THE DETERMINISTIC MODEL OUTPUT AND IN MANY LOCALES
SURFACE TEMPERATURES WILL RISE ABOVE 32 F OVERNIGHT...SO THE AREA
WITH A RISK OF LIGHT FREEZING RAIN WILL LIKELY BE SMALL IN SPACE
AND TIME...AND CENTERED MAINLY FROM BOTTINEAU TOWARD ROLLA.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 250 PM CST TUE DEC 8 2015
STRONG WINDS AND POSSIBLE MIXED PRECIPITATION HIGHLIGHT THE EARLY
PORTION OF THE EXTENDED PERIOD WITH A COOLING TREND AS WE HEAD
INTO THE UPCOMING WEEKEND.
A STRONG S/WV TROUGH MOVES EAST ACROSS THE NORTHERN PLAINS
WEDNESDAY NIGHT. MODELS ARE STILL INDICATING ALL RAIN ACROSS THE
SOUTHERN TWO THIRDS OF THE STATE WHERE AIR TEMPERATURES REMAINS
ABOVE FREEZING...WITH A WINTRY MIX POSSIBLE FAR NORTH WHERE
TEMPERATURES WILL BE CLOSER TO FREEZING OR BELOW. STRONG CAA IN
THE WAKE OF WED NIGHTS WAVE WILL SEE DAYTIME TEMPERATURES 10-20
DEGREES COLDER THURSDAY COMPARED TO WEDNESDAY...WITH ALSO WRAP
AROUND RAIN OR SNOW SURGING SOUTH AND EAST ACROSS THE STATE.
STRONG WINDS REMAIN A CONCERN LATE WED NIGHT INTO THURSDAY BEHIND
THE SFC LOW WITH STRONG PRESSURE RISES DEVELOPING EAST ACROSS THE
DAKOTAS. MODELS REMAIN OUT OF SYNC AS FAR AS THE LOW PRESSURE
PLACEMENT AND TIMING OF WINDS...AS WELL AS MIXING LAYER HEIGHTS
AND THUS POTENTIAL WIND GUSTS. WE OPTED TO HOLD OFF ON ANY
HEADLINES AND LET THE MID SHIFT TONIGHT RELOOK LATEST 00Z
GUIDANCE WHICH HOPEFULLY NARROWS THINGS DOWN BETTER.
YET ANOTHER POTENT S/WV TROUGH MOVES ACROSS THE REGION LATE
THURSDAY NIGHT INTO FRIDAY. THIS TIME THE ATMOSPHERIC PROFILE
WILL BE COLD ENOUGH FOR ALL SNOW. THIS FEATURE WILL BE MORE
INTERESTING WITH A MORE DEFINED SFC TROUGH AXIS EXTENDING INTO
OUR AREA ALONG WITH STRONGER UPPER LEVEL JET DYNAMICS. WILL
MONITOR THIS PERIOD CLOSE OVER THE NEXT DAY OR TWO WITH NEAR
ADVISORY ACCUMULATIONS STILL POSSIBLE. HOWEVER...LATEST MODELS
ARE MORE PROGRESSIVE SO FORECAST SNOW AMOUNTS HAVE BEEN REDUCED
TO MORE IN THE 1-2 INCH RANGE. REINFORCED SHOT OF COLDER AIR
FOLLOWS FOR THE WEEKEND...WHICH ALSO LOOKS DRY. WILL NEED TO
MONITOR MODELS CLOSELY FOR EARLY TO MID NEXT WEEK AS STRONG ENERGY
MOVES INTO THE PACIFIC NORTHWEST LATE THIS WEEKEND...AND WHICH MAY
EVENTUALLY IMPACT THE NORTHERN PLAINS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1232 AM CST WED DEC 9 2015
VFR AT ALL TAF SITES THROUGH THE TAF PERIOD. THERE IS A SLIGHT
CHANCE THAT TERMINALS COULD SEE SOME VERY LIGHT
RAIN...HOWEVER...DUE TO THE SCATTERED NATURE OF LIGHT RAIN
CONFIDENCE WASN`T HIGH ENOUGH AT ANY INDIVIDUAL TERMINAL TO
MENTION IN THE TAF.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...AJ
SHORT TERM...CJS
LONG TERM...NH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS NORMAN OK
525 PM CST THU DEC 10 2015
.AVIATION...
LIGHT WINDS WILL GRADUALLY SHIFT TO THE SOUTH LATE TONIGHT WITH
ABUNDANT HIGH CLOUDS. SOUTH TO SOUTHWEST WINDS WILL INCREASE TO 10
TO 15KTS BY MID/LATE MORNING.
30
&&
.PREV DISCUSSION... /ISSUED 347 PM CST THU DEC 10 2015/
.DISCUSSION...
THERE ARE SEVERAL WEATHER CONCERNS INCLUDING FOG POTENTIAL LATE
TONIGHT INTO FRIDAY MORNING...RECORD WARMTH AND WILDFIRE
DANGER ON FRIDAY...THEN STRONG TO SEVERE STORMS SATURDAY AND
SATURDAY NIGHT.
LATE TONIGHT INTO FRIDAY MORNING...WILL MONITOR FOR FOG
POTENTIAL...MAINLY EAST OF A MARIETTA TO ARDMORE TO SHAWNEE
LINE...WHERE LOW LEVEL MOISTURE WILL POOL NEAR A WEAK SURFACE
TROUGH. SOME OF THIS FOG COULD BE DENSE WITH VISIBILITIES UNDER
1/4 MILE. THE LATEST HRRR RUNS HAVE BEEN HINTING AT THIS FOG
DEVELOPMENT...SO ADDED MENTION. NOT SURE HOW FAR WEST THE FOG
DEVELOPMENT WILL OCCUR/EXPAND. THERE IS AN OUTSIDE CHANCE THE
OKLAHOMA CITY METRO...STILLWATER...AND PONCA CITY AREAS COULD BE
AFFECTED BY THE FOG AS WELL...THOUGH CONFIDENCE IS RATHER LOW.
WENT WITH THE COLDER SIDE OF GUIDANCE LOWS TONIGHT ACROSS MUCH OF
THE AREA DUE TO LIGHT WINDS....LOW SURFACE DEWPOINTS IN MOST
LOCATIONS...AND ONLY HIGH CLOUDS OVERHEAD WHICH WILL ALLOW FOR
RAPID RADIATIONAL COOLING.
FRIDAY WILL BE PARTLY TO MOSTLY SUNNY AND UNSEASONABLY WARM WITH A
SOUTH TO SOUTHWEST BREEZE. WENT TOWARDS THE WARMER SIDE OF
GUIDANCE EXCEPT EAST OF I-35 WHERE MORNING FOG/CLOUDS MAY HAMPER
HEATING A BIT. THE 80 DEGREE MARK WILL LIKELY BE EXCEEDED IN PARTS
OF WESTERN NORTH TEXAS AND SOUTHWESTERN OKLAHOMA. HIGH LEVEL CLOUD
COVER REMAINS A BIT UNCERTAIN AND COULD KEEP TEMPERATURES DOWN IF
IT IS THICKER THAN CURRENTLY FORECAST.
FRIDAY NIGHT...LOW LEVEL MOISTURE AND CLOUDS WILL INCREASE ACROSS
THE AREA. KEPT MENTION OF FOG AND DRIZZLE NEAR ATOKA AND DURANT
WHERE LOW LEVEL MOISTURE WILL BE DEEPEST. FOG MAY FORM ACROSS MUCH
OF THE AREA...THOUGH NOT CONFIDENT IT WILL BE DENSE AS LOW LEVEL
WINDS MAY KEEP THE AIR SLIGHTLY MIXED NEAR THE GROUND.
SATURDAY MORNING INTO EARLY AFTERNOON...CLOUDY SKIES...FOG...AND
PERHAPS DRIZZLE WILL OCCUR ACROSS MUCH OF THE AREA. THERE IS A
CHANCE FOR SOME SHOWER AND THUNDERSTORM ACTIVITY...THOUGH MOST OF
THE DAY COULD BE RAINFREE DUE TO STRONG CAPPING. IF STORMS
FORM...THEY WOULD LIKELY BE ELEVATED IN NATURE AND COULD PRODUCE
LOCALLY HEAVY DOWNPOURS AND MARGINALLY SEVERE HAIL UP TO QUARTERS
AS MID LEVEL LAPSE RATES WILL BE RATHER STEEP 7 TO 8 C/KM. APPEARS
THE GREATER CHANCES FOR STORMS WILL BE OVER SOUTHERN OR
SOUTHEASTERN OKLAHOMA DURING THIS TIME FRAME. THINK CLOUD COVER
WILL LIMIT HEATING...SO WENT COOLER THAN GUIDANCE HIGHS.
LATE SATURDAY AFTERNOON INTO SATURDAY NIGHT...STORM CHANCES WILL
INCREASE ACROSS THE ENTIRE AREA AS THE MID/UPPER LOW APPROACH.
FIRST STORMS MAY FORM NEAR THE DRYLINE TOWARDS SUNSET SATURDAY IN
FAR WESTERN OKLAHOMA AND FAR WESTERN TEXAS...THEN ORGANIZE INTO A
SQUALL LINE...PUSHING EASTWARD THROUGH THE NIGHT. FIRST STORMS
WOULD HAVE A CHANCE OF BEING DISCRETE AND SUPERCELLULAR DUE TO THE
VERY STRONG SHEAR WHICH WOULD SUPPORT LARGE HAIL AS THE MAIN
HAZARD...ESPECIALLY IF PARTIAL CLEARING AND SURFACE HEATING OCCUR.
POCKETS OF DAMAGING WINDS WITH MESOVORTICES ALONG THE SQUALL LINE
COULD OCCUR. THE AMOUNT OF INSTABILITY REMAINS VERY QUESTIONABLE
AS CLOUD COVER MAY LIMIT LOW LEVEL DESTABILIZATION. TORNADO
POTENTIAL APPEARS TO BE RATHER LOW DUE TO WEAK LOW LEVEL
INSTABILITY. SOME LOCATIONS MAY GET AN INCH OR TWO OF RAINFALL IN
AN HOUR OR TWO WHICH COULD PRODUCE MINOR FLOODING IN A FEW
LOCATIONS.
SUNDAY INTO SUNDAY NIGHT...THE MID/UPPER LOW WILL BRING ADDITIONAL
CHANCES FOR PRECIPITATION OVER MAINLY THE NORTHERN HALF OF
OKLAHOMA...WHILE THE MID/UPPER LEVEL DRY SLOT BRINGS DRY
CONDITIONS TO SOUTHERN OKLAHOMA AND NORTH TEXAS. KEPT A RAIN/SNOW
MIX OVER FAR NORTHERN OKLAHOMA DURING THIS TIME FRAME...THOUGH
LATEST MODEL SOLUTIONS HAVE BEEN TRENDING WARMER AND FARTHER NORTH
WITH THE MID/UPPER LOW WHICH WOULD PUSH THE CHANCES FOR SNOW INTO
KANSAS. ACCUMULATING SNOW SEEMS UNLIKELY EVEN IN NORTHERN OKLAHOMA
BASED ON LATEST MODEL GUIDANCE AS LOW LEVEL TEMPERATURES APPEAR TO
BE TOO WARM.
MONDAY THROUGH NEXT THURSDAY...A DRY AND COLDER WEATHER PATTERN IS
FORECAST...THOUGH CONFIDENCE IS LOW. TEMPERATURES MAY BE BELOW
AVERAGE BY TUESDAY NIGHT THEN CONTINUE THROUGH THE END OF THE
WEEK.
MBS
&&
.FIRE WEATHER...
UNSEASONABLY WARM TEMPERATURES...DRY CONDITIONS...LOW HUMIDITY...
ABUNDANT FUELS TO BURN....AND BREEZY CONDITIONS WILL LIKELY
ELEVATE FIRE WEATHER CONCERNS ON FRIDAY...ESPECIALLY OVER WESTERN
OKLAHOMA AND WESTERN NORTH TEXAS. WINDS APPEAR TO BE BELOW 20 MPH
TO KEEP RED FLAG CONDITIONS FROM OCCURRING.
&&
.CLIMATE...
RECORD HIGHS ARE POSSIBLE...IF NOT LIKELY...ACROSS THE AREA ON
FRIDAY. HERE ARE THE RECORDS.
OKLAHOMA CITY...75 DEGREES SET IN 1939
WICHITA FALLS...79 DEGREES SET IN 1929
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 38 72 53 67 / 0 0 10 30
HOBART OK 38 77 48 67 / 0 0 10 20
WICHITA FALLS TX 39 79 55 69 / 0 0 10 30
GAGE OK 38 77 39 65 / 0 0 0 10
PONCA CITY OK 38 72 51 66 / 0 0 10 40
DURANT OK 48 71 62 68 / 0 0 20 70
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
TX...NONE.
&&
$$
06/17
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
550 PM EST WED DEC 9 2015
.SYNOPSIS...
A WEAKENING COLD FRONT WILL TRACK THROUGH THE REGION LATER
TONIGHT AND EARLY THURSDAY...FOLLOWED AN ANOMALOUSLY STRONG UPPER
RIDGE THAT WILL BRING WARMER THAN NORMAL CONDITIONS FROM THE END
OF THE WEEK INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
NE WIND HAS RESULTED IN MORE DENSE FOG AT AOO. MOST AREAS
SE TO NW WINDS NOW.
OTHER SITES NOT BAD...WILL CONTINUE TO MONITOR THE NEED FOR
A DENSE FOG OR FREEZING FOG ADVISORY.
STILL A STRONG INVERSION IN PLACE...BUT BINOVC ALLOWED
TEMPERATURES TO CLIMB ABOVE HIGHS YESTERDAY BY ABOUT
5 TO 10 DEGREES.
ALSO WINDS PICKING UP FROM THE SOUTH...VAD WINDS ABOUT 20 KNOTS
AT 3000 FEET.
LINE OF VERY LIGHT SHOWERS TO THE WEST. WILL HAVE TO MONITOR
THE TEMPERATURES. STILL 32 DEGREES AT THE RDA.
EARLIER DISCUSSION BELOW.
SATELLITE SHOWS THE LOW CLOUDS MELTING AWAY VERY...VERY SLOWLY AT
THE EDGES. OTHERWISE BANDS OF FRONTAL CLOUDS ASSOCIATED WITH A
WEAKENING COLD FRONT ARE ENTERING EASTERN OHIO AND WILL OVERSPREAD
THE REGION TONIGHT.
HAVE BEEN USING THE HRRR TRYING TO GET A HANDLE ON THE VERY NEAR
TERM CLOUDS AND TEMPERATURE TRENDS. IT HAS BEEN TOO FAST ERODING
THE LOW CLOUDS BUT 2M TEMPS AND PBL PROGS SUGGEST KEEPING THE
IMPROVEMENT SLOW FOR CENTRAL AREAS.
NEAR TERM MODELS ARE IN GOOD AGREEMENT IN SHEARING THE PARENT
UPPER TROUGH OUT AND TRACKING IT NORTH OF THE REGION. RAIN SHOWERS
WILL APPROACH MY FAR NWRN ZONES BY NIGHTFALL BEFORE TRACKING
ACROSS THE FCST AREA OVERNIGHT AND WEAKENING. THE BEST CHANCE FOR
RAIN WILL BE OVER THE NORTHWEST AND DURING THE HOURS BEFORE
MIDNIGHT...WITH POPS DWINDLING OVER CENTRAL AND EASTERN AREAS FOR
THE SECOND HALF OF THE OVERNIGHT.
OVERNIGHT LOWS IN THE MID TO UPPER 30S WILL ACTUALLY AVERAGE SOME
10-15 DEG WARMER THAN NORMAL IN MOST SPOTS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
ANOTHER WEAKENING FRONT IS EXPECTED TO SHEAR OUT TO OUR NW...WITH
HIGH PRESSURE ESTABLISHING ITSELF OFF TO OUR SOUTHWEST. THE NET
EFFECT WILL BE FOR A SOUTHWEST FLOW TO SET UP WHICH SHOULD HELP
SCOUR OUT THE PERSISTENT LOW CLOUDS AND FOG THAT HAVE PLAGUED THE
REGION FOR THE LAST SEVERAL DAYS.
WITH AN INCREASE IN SUNSHINE AND A MILDER SOUTHWEST FLOW EXPECTED
TO DEVELOP...HIGHS TUESDAY WILL AVERAGE IN THE LOW TO MID
50S...STILL SOME 10-15 DEG WARMER THAN NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS AND FOG MAY COMPLICATE
THINGS AT FIRST AND WILL ASSESS THIS RISK IN THE SHORT RANGE.
THE GREATEST RISK FOR RAIN WILL LIKELY BE ON MONDAY WITH ABOVE
AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS FAR OUT GIVEN VERY
GOOD MODEL AND ENSEMBLE AGREEMENT. TEMPERATURES ARE FCST TO STAY
RELATIVELY MILD FOR DECEMBER THROUGH MUCH OF NEXT WEEK WITH A COOL
DOWN TO "NEAR NORMAL" POSSIBLE AROUND THE 18-19TH.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
WITH THE EXCEPTION OF BFD/JST...LOW CLOUDS CONTINUE TO PLAGUE
CENTRAL AND EASTERN PA TERMINALS. THERE ARE SIGNS HOWEVER THAT THE
LOW CLOUDS ARE BEGINNING TO ERODE AROUND THE EDGES WITH ALTOONA
RECENTLY IMPROVING TO 2 MILES IN FOG AND EVEN A FEW RAYS OF SUN
BEING SEEN OUT THE WINDOW HERE AT TIMES. I`M NOT TOO OPTIMISTIC
FOR WIDESPREAD IMPROVEMENT HOWEVER AS WE HAVE VERY LOW SUN ANGLES
AND STILL VERY LIGHT WINDS.
HRRR STILL SHOWS THE LOW CLOUDS OVER CENTRAL PA FINALLY BEGINNING
TO BREAK UP DURING THE AFTERNOON...WITH THE LOW CLOUDS HANGING
TOUGH OVER THE LOWER SUSQ VALLEY.
WINDS WILL GENERALLY BE LIGHT...WITH SPEEDS OVER THE NW MOUNTAINS
INCREASING TO AROUND 8-10KT THIS AFTERNOON AHEAD OF AN
APPROACHING WEAK TROUGH.
THE WEAK TROUGH WILL MOVE INTO THE REGION TONIGHT AND BRING AN
INFLUX OF LOW-LEVEL MOISTURE TO WESTERN AND CENTRAL PA. THIS WILL
BRING A RETURN OF CIG RESTRICTIONS TO WESTERN AND CENTRAL SECTIONS
ALONG WITH SOME LIGHT RAIN SHOWERS. OVER MY SOUTHEASTERN TERMINALS
THE LOW CLOUDS FROM TODAY WILL CONTINUE TO HANG TOUGH WITH EVEN
THE POTENTIAL FOR THE FOG TO REDEVELOP UNDER THE PERSISTENT LOW
LEVEL INVERSION.
THE WEAKENING FRONT/TROUGH WILL SWING THROUGH THE AREA LATE
TONIGHT OR EARLY THURSDAY AND FINALLY BRING A DRIER WESTERLY FLOW
TO THE LOCAL FLYING AREA. WE SHOULD START THE DAY WITH FAIRLY
WIDESPREAD IFR/MVFR CEILINGS AND EVEN SOME FOG OVER EASTERN
AREAS...BUT CONDITIONS WILL IMPROVE TO VFR BY LATE MORNING OR
EARLY AFTERNOON AS THE WEST-SOUTHWEST FLOW FRESHENS.
OUTLOOK...
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE/MARTIN
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
347 PM EST WED DEC 9 2015
.SYNOPSIS...
A WEAKENING COLD FRONT WILL TRACK THROUGH THE REGION LATER
TONIGHT AND EARLY THURSDAY...FOLLOWED AN ANOMALOUSLY STRONG UPPER
RIDGE THAT WILL BRING WARMER THAN NORMAL CONDITIONS FROM THE END
OF THE WEEK INTO NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
SATELLITE SHOWS THE LOW CLOUDS MELTING AWAY VERY...VERY SLOWLY AT
THE EDGES. OTHERWISE BANDS OF FRONTAL CLOUDS ASSOCIATED WITH A
WEAKENING COLD FRONT ARE ENTERING EASTERN OHIO AND WILL OVERSPREAD
THE REGION TONIGHT.
HAVE BEEN USING THE HRRR TRYING TO GET A HANDLE ON THE VERY NEAR
TERM CLOUDS AND TEMPERATURE TRENDS. IT HAS BEEN TOO FAST ERODING
THE LOW CLOUDS BUT 2M TEMPS AND PBL PROGS SUGGEST KEEPING THE
IMPROVEMENT SLOW FOR CENTRAL AREAS.
NEAR TERM MODELS ARE IN GOOD AGREEMENT IN SHEARING THE PARENT
UPPER TROUGH OUT AND TRACKING IT NORTH OF THE REGION. RAIN SHOWERS
WILL APPROACH MY FAR NWRN ZONES BY NIGHTFALL BEFORE TRACKING
ACROSS THE FCST AREA OVERNIGHT AND WEAKENING. THE BEST CHANCE FOR
RAIN WILL BE OVER THE NORTHWEST AND DURING THE HOURS BEFORE
MIDNIGHT...WITH POPS DWINDLING OVER CENTRAL AND EASTERN AREAS FOR
THE SECOND HALF OF THE OVERNIGHT.
OVERNIGHT LOWS IN THE MID TO UPPER 30S WILL ACTUALLY AVERAGE SOME
10-15 DEG WARMER THAN NORMAL IN MOST SPOTS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH 6 PM THURSDAY/...
ANOTHER WEAKENING FRONT IS EXPECTED TO SHEAR OUT TO OUR NW...WITH
HIGH PRESSURE ESTABLISHING ITSELF OFF TO OUR SOUTHWEST. THE NET
EFFECT WILL BE FOR A SOUTHWEST FLOW TO SET UP WHICH SHOULD HELP
SCOUR OUT THE PERSISTENT LOW CLOUDS AND FOG THAT HAVE PLAGUED THE
REGION FOR THE LAST SEVERAL DAYS.
WITH AN INCREASE IN SUNSHINE AND A MILDER SOUTHWEST FLOW EXPECTED
TO DEVELOP...HIGHS TUESDAY WILL AVERAGE IN THE LOW TO MID
50S...STILL SOME 10-15 DEG WARMER THAN NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH WEDNESDAY/...
ABOVE NORMAL TO NEAR-RECORD WARMTH WILL BE THE MAIN STORY THIS
PERIOD...WITH DAYTIME HIGHS FCST +20 TO +30 DEGREES ABOVE CLIMO
BY LATE IN THE WEEKEND. POSSIBLE LOW CLOUDS AND FOG MAY COMPLICATE
THINGS AT FIRST AND WILL ASSESS THIS RISK IN THE SHORT RANGE.
THE GREATEST RISK FOR RAIN WILL LIKELY BE ON MONDAY WITH ABOVE
AVERAGE CONFIDENCE IN THE PCPN PATTERN THIS FAR OUT GIVEN VERY
GOOD MODEL AND ENSEMBLE AGREEMENT. TEMPERATURES ARE FCST TO STAY
RELATIVELY MILD FOR DECEMBER THROUGH MUCH OF NEXT WEEK WITH A COOL
DOWN TO "NEAR NORMAL" POSSIBLE AROUND THE 18-19TH.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
WITH THE EXCEPTION OF BFD/JST...LOW CLOUDS CONTINUE TO PLAGUE
CENTRAL AND EASTERN PA TERMINALS. THERE ARE SIGNS HOWEVER THAT THE
LOW CLOUDS ARE BEGINNING TO ERODE AROUND THE EDGES WITH ALTOONA
RECENTLY IMPROVING TO 2 MILES IN FOG AND EVEN A FEW RAYS OF SUN
BEING SEEN OUT THE WINDOW HERE AT TIMES. I`M NOT TOO OPTIMISTIC
FOR WIDESPREAD IMPROVEMENT HOWEVER AS WE HAVE VERY LOW SUN ANGLES
AND STILL VERY LIGHT WINDS.
HRRR STILL SHOWS THE LOW CLOUDS OVER CENTRAL PA FINALLY BEGINNING
TO BREAK UP DURING THE AFTERNOON...WITH THE LOW CLOUDS HANGING
TOUGH OVER THE LOWER SUSQ VALLEY.
WINDS WILL GENERALLY BE LIGHT...WITH SPEEDS OVER THE NW MOUNTAINS
INCREASING TO AROUND 8-10KT THIS AFTERNOON AHEAD OF AN
APPROACHING WEAK TROUGH.
THE WEAK TROUGH WILL MOVE INTO THE REGION TONIGHT AND BRING AN
INFLUX OF LOW-LEVEL MOISTURE TO WESTERN AND CENTRAL PA. THIS WILL
BRING A RETURN OF CIG RESTRICTIONS TO WESTERN AND CENTRAL SECTIONS
ALONG WITH SOME LIGHT RAIN SHOWERS. OVER MY SOUTHEASTERN TERMINALS
THE LOW CLOUDS FROM TODAY WILL CONTINUE TO HANG TOUGH WITH EVEN
THE POTENTIAL FOR THE FOG TO REDEVELOP UNDER THE PERSISTENT LOW
LEVEL INVERSION.
THE WEAKENING FRONT/TROUGH WILL SWING THROUGH THE AREA LATE
TONIGHT OR EARLY THURSDAY AND FINALLY BRING A DRIER WESTERLY FLOW
TO THE LOCAL FLYING AREA. WE SHOULD START THE DAY WITH FAIRLY
WIDESPREAD IFR/MVFR CEILINGS AND EVEN SOME FOG OVER EASTERN
AREAS...BUT CONDITIONS WILL IMPROVE TO VFR BY LATE MORNING OR
EARLY AFTERNOON AS THE WEST-SOUTHWEST FLOW FRESHENS.
OUTLOOK...
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...STEINBUGL
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
211 PM EST WED DEC 9 2015
.SYNOPSIS...
A WEAKENING COLD FRONT WILL TRACK THROUGH THE REGION LATER
TONIGHT AND EARLY THURSDAY...FOLLOWED AN ANOMALOUSLY STRONG UPPER
RIDGE THAT WILL BRING WARMER THAN NORMAL CONDITIONS FROM THE END
OF THE WEEK INTO NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
SATELLITE SHOWS THE LOW CLOUDS MELTING AWAY VERY...VERY SLOWLY AT
THE EDGES. OTHERWISE BANDS OF FRONTAL CLOUDS ASSOCIATED WITH A
WEAKENING COLD FRONT ARE ENTERING EASTERN OHIO AND WILL OVERSPREAD
THE REGION TONIGHT.
HAVE BEEN USING THE HRRR TRYING TO GET A HANDLE ON THE VERY NEAR
TERM CLOUDS AND TEMPERATURE TRENDS. IT HAS BEEN TOO FAST ERODING
THE LOW CLOUDS BUT 2M TEMPS AND PBL PROGS SUGGEST KEEPING THE
IMPROVEMENT SLOW FOR CENTRAL AREAS.
NEAR TERM MODELS ARE IN GOOD AGREEMENT IN SHEARING THE PARENT
UPPER TROUGH OUT AND TRACKING IT NORTH OF THE REGION. RAIN SHOWERS
WILL APPROACH MY FAR NWRN ZONES BY NIGHTFALL BEFORE TRACKING
ACROSS THE FCST AREA OVERNIGHT AND WEAKENING. THE BEST CHANCE FOR
RAIN WILL BE OVER THE NORTHWEST AND DURING THE HOURS BEFORE
MIDNIGHT...WITH POPS DWINDLING OVER CENTRAL AND EASTERN AREAS FOR
THE SECOND HALF OF THE OVERNIGHT.
OVERNIGHT LOWS IN THE MID TO UPPER 30S WILL ACTUALLY AVERAGE SOME
10-15 DEG WARMER THAN NORMAL IN MOST SPOTS.
&&
.SHORT TERM /THURSDAY/...
ANOTHER WEAKENING FRONT IS EXPECTED TO SHEAR OUT TO OUR NW...WITH
HIGH PRESSURE ESTABLISHING ITSELF OFF TO OUR SOUTHWEST. THE NET
EFFECT WILL BE FOR A SOUTHWEST FLOW TO SET UP WHICH SHOULD HELP
SCOUR OUT THE PERSISTENT LOW CLOUDS AND FOG THAT HAVE PLAGUED THE
REGION FOR THE LAST SEVERAL DAYS.
WITH AN INCREASE IN SUNSHINE AND A MILDER SOUTHWEST FLOW EXPECTED
TO DEVELOP...HIGHS TUESDAY WILL AVERAGE IN THE LOW TO MID
50S...STILL SOME 10-15 DEG WARMER THAN NORMAL.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE MAIN STORY FOR THE LONG TERM CONTINUES TO BE UNSEASONABLY
MILD WEATHER...AS WE EXPECT TEMPERATURES ARE EXPECTED TO REMAIN
ABOVE- NORMAL RIGHT INTO EARLY NEXT WEEK.
AS FOR PRECIPITATION...A WEAKENING TROUGH OF LOW PRESSURE COULD
BRING A FEW SHOWERS MAINLY ACROSS THE NORTH AND WEST THU NITE
INTO FRI.
SATURDAY INTO SUNDAY WILL SEE A SIGNIFICANT UPPER-LEVEL RIDGE
BUILD OVER THE EAST COAST. INCREASINGLY SOUTHERLY FLOW SHOULD
BRING IN EVEN MILDER TEMPERATURES THIS WEEKEND...WITH SOME
LOCATIONS SEEING AFTERNOON HIGHS APPROACHING 20 DEGREES ABOVE-
NORMAL.
A MORE SIGNIFICANT STORM SYSTEM WILL TRACK ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND MONDAY INTO TUESDAY...DRAGGING A COLD FRONT
ACROSS CENTRAL PA. THIS SYSTEM WILL BE ACCOMPANIED BY A PERIOD OF
SHOWERY WEATHER...AND FOLLOWED BY A COOL-DOWN BY THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
WITH THE EXCEPTION OF BFD/JST...LOW CLOUDS CONTINUE TO PLAGUE
CENTRAL AND EASTERN PA TERMINALS. THERE ARE SIGNS HOWEVER THAT THE
LOW CLOUDS ARE BEGINNING TO ERODE AROUND THE EDGES WITH ALTOONA
RECENTLY IMPROVING TO 2 MILES IN FOG AND EVEN A FEW RAYS OF SUN
BEING SEEN OUT THE WINDOW HERE AT TIMES. I`M NOT TOO OPTIMISTIC
FOR WIDESPREAD IMPROVEMENT HOWEVER AS WE HAVE VERY LOW SUN ANGLES
AND STILL VERY LIGHT WINDS.
HRRR STILL SHOWS THE LOW CLOUDS OVER CENTRAL PA FINALLY BEGINNING
TO BREAK UP DURING THE AFTERNOON...WITH THE LOW CLOUDS HANGING
TOUGH OVER THE LOWER SUSQ VALLEY.
WINDS WILL GENERALLY BE LIGHT...WITH SPEEDS OVER THE NW MOUNTAINS
INCREASING TO AROUND 8-10KT THIS AFTERNOON AHEAD OF AN
APPROACHING WEAK TROUGH.
THE WEAK TROUGH WILL MOVE INTO THE REGION TONIGHT AND BRING AN
INFLUX OF LOW-LEVEL MOISTURE TO WESTERN AND CENTRAL PA. THIS WILL
BRING A RETURN OF CIG RESTRICTIONS TO WESTERN AND CENTRAL SECTIONS
ALONG WITH SOME LIGHT RAIN SHOWERS. OVER MY SOUTHEASTERN TERMINALS
THE LOW CLOUDS FROM TODAY WILL CONTINUE TO HANG TOUGH WITH EVEN
THE POTENTIAL FOR THE FOG TO REDEVELOP UNDER THE PERSISTENT LOW
LEVEL INVERSION.
THE WEAKENING FRONT/TROUGH WILL SWING THROUGH THE AREA LATE
TONIGHT OR EARLY THURSDAY AND FINALLY BRING A DRIER WESTERLY FLOW
TO THE LOCAL FLYING AREA. WE SHOULD START THE DAY WITH FAIRLY
WIDESPREAD IFR/MVFR CEILINGS AND EVEN SOME FOG OVER EASTERN
AREAS...BUT CONDITIONS WILL IMPROVE TO VFR BY LATE MORNING OR
EARLY AFTERNOON AS THE WEST-SOUTHWEST FLOW FRESHENS.
OUTLOOK...
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
SUN...MAINLY VFR.
MON...FROPA WITH WIDESPREAD SHOWERS AND MVFR/IFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...LA CORTE
SHORT TERM...LA CORTE
LONG TERM...EVANEGO
AVIATION...LA CORTE
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1049 AM EST WED DEC 9 2015
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY RELAX ITS GRIP ON THE REGION TODAY. A
SERIES OF WEAK FRONTS WILL TRACK WELL WEST OF PA LATE IN THE WEEK
AS AN ANOMALOUS UPPER RIDGE BUILDS ALONG THE EAST COAST.
TEMPERATURES WILL BE WARMER THAN NORMAL FOR MUCH OF THE NEXT WEEK
OR TWO.
&&
.NEAR TERM /UNTIL 2 PM THIS AFTERNOON/...
AREAS OF DENSE...FREEZING FOG BLANKETING THE DEEPER VALLEYS IN THE
CENTRAL MTNS REGION...WILL GRADUALLY BURN OFF THROUGH MID DAY. THE
EXCEPTION WILL BE THE LOWER SUSQ WHERE THE EXPERIMENTAL HRRR SHOWS
THE LOW CLOUDS HANGING ON WELL INTO THE DAY.
HAVE EXTENDED THE ADVISORY FOR FOG THROUGH NOON TO COVER THE SLOW
BURN OFF. OTHER THAN POCKETS OF PATCHY DRIZZLE/FREEZING
DRIZZLE...THE CHANCES FOR RAIN WILL REMAIN VERY LOW UNTIL LATER
TODAY OR THIS EVENING AS SHOWERS ASSOCIATED WITH A DYING COLD
FRONT BEGIN TO THREATEN MY FAR NWRN ZONES.
&&
.SHORT TERM /2 PM THIS AFTERNOON THROUGH 6 PM THURSDAY/...
THE MORNING FOG WILL BE SLOW TO DISSIPATE...BUT INCREASING
BOUNDARY LAYER FLOW AHEAD OF ANOTHER SHEARING UPPER WAVE AND
AMPLIFYING UPPER FLOW MAY FINALLY HELP SCOUR THINGS OUT LATE THIS
AFTERNOON /MORE THAN WE`VE SEEN IN A FEW DAYS/.
SOME BREAKS OF MID TO LATE AFTERNOON SUN ARE POSSIBLE...THANKS IN
PART TO WARMING TEMPS ALOFT AND INCREASING SOUTHERLY FLOW.
MAX TEMPS SHOULD ONLY REACH THE MID 40S ACRS MUCH OF THE CENTRAL
AND NRN MTNS...WHILE NEARING THE 50F MARK ACROSS THE SE ZONES. THE
MERCURY MAY HAVE DIFFICULTY RISING ABOVE 40F OVER THE MTNS NORTH
OF KIPT.
MOISTURE INCREASES SUFFICIENTLY AHEAD OF APPROACHING SHORTWAVE AND
WEAK SFC CFRONT TO INTRODUCE A CHANCE OF SHOWERS BY THIS EVENING
ACROSS THE NW MTNS. ELSEWHERE...NO MENTION OF PRECIP OUTSIDE OF
THE PREVIOUSLY NOTED PATCHY DRIZZLE /MAINLY ON THE SOUTH-SE FACING
SLOPES OF THE RIDGES/.
WILL HAVE TO CLOSELY MONITOR THE REGION NEAR AND TO THE EAST OF
THE SUSQ MAINSTEM WHERE ABUNDANT LLVL MOISTURE COULD ONCE AGAIN
STAY TRAPPED BENEATH A FAIRLY STRONG SFC BASED INVERSION...AND
LEAD TO WIDESPREAD LOW CLOUDS AND AREAS OF DENSE FOG. ON THE
POSITIVE SIDE...AT LEAST MIN TEMPS EARLY THURSDAY WILL BE IN THE
MID TO UPPER 30S...NEGATING THE CHC FOR FREEZING FOG.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE MAIN STORY FOR THE LONG TERM CONTINUES TO BE UNSEASONABLY
MILD WEATHER...AS WE EXPECT TEMPERATURES ARE EXPECTED TO REMAIN
ABOVE- NORMAL RIGHT INTO EARLY NEXT WEEK.
AS FOR PRECIPITATION...A WEAKENING TROUGH OF LOW PRESSURE COULD
BRING A FEW SHOWERS ACROSS CENTRAL PA WED NIGHT INTO THU...WITH
ANOTHER TROUGH PROVIDING A SLIGHT CHC FOR SHOWERS ACROSS MAINLY
THE NORTH AND WEST THU NITE INTO FRI.
SATURDAY INTO SUNDAY WILL SEE A SIGNIFICANT UPPER-LEVEL RIDGE
BUILD OVER THE EAST COAST. INCREASINGLY SOUTHERLY FLOW SHOULD
BRING IN EVEN MILDER TEMPERATURES THIS WEEKEND...WITH SOME
LOCATIONS SEEING AFTERNOON HIGHS APPROACHING 20 DEGREES ABOVE-
NORMAL.
A MORE SIGNIFICANT STORM SYSTEM WILL TRACK ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND MONDAY INTO TUESDAY...DRAGGING A COLD FRONT
ACROSS CENTRAL PA. THIS SYSTEM WILL BE ACCOMPANIED BY A PERIOD OF
SHOWERY WEATHER...AND FOLLOWED BY A COOL-DOWN BY THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION /16Z WEDNESDAY THROUGH SUNDAY/...
WITH THE EXCEPTION OF BFD/JST...LOW CLOUDS AND DENSE FOG CONTINUE
TO PLAGUE CENTRAL AND EASTERN PA TERMINALS.
HRRR SHOWS THE LOW CLOUDS OVER CENTRAL PA FINALLY BEGINNING TO
BREAK UP BY EARLY AFTERNOON...WITH THE LOW CLOUDS HANGING TOUGH
OVER THE LOWER SUSQ VALLEY.
WINDS WILL GENERALLY BE LIGHT...WITH SPEEDS OVER THE NW MOUNTAINS
INCREASING TO AROUND 8-10KT THIS AFTERNOON AHEAD OF AN
APPROACHING WEAK TROUGH THAT WILL LIFT THROUGH TONIGHT.
WEAK TROUGH LIFTING SW-NE OVER THE REGION TONIGHT WILL BRING AN
INFLUX OF LOW-LEVEL MOISTURE TO WESTERN AND CENTRAL PA. THIS WILL
BRING A SOLID AREA OF CIG RESTRICTIONS TO WESTERN SECTIONS ALONG
WITH SOME LIGHT RAIN SHOWERS. OVER MY SOUTHEASTERN TERMINALS THIS
MOISTURE UNDER THE RETREATING INVERSION LOOKS TO KEEP LOW CLOUDS
AND AREAS OF FOG LOCKED IN.
OUTLOOK...
THU...MORNING FOG/RESTRICTIONS. IMPROVEMENT IN THE AFT...WITH MVFR
CIGS NW HALF AND VFR SE.
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT-SUN...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL NOON EST TODAY FOR PAZ012-017>019-
025>028-034-035-041-045-046-049-050.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1032 AM EST WED DEC 9 2015
.SYNOPSIS...
HIGH PRESSURE WILL GRADUALLY RELAX ITS GRIP ON THE REGION TODAY. A
SERIES OF WEAK FRONTS WILL TRACK WELL WEST OF PA LATE IN THE WEEK
AS AN ANOMALOUS UPPER RIDGE BUILDS ALONG THE EAST COAST.
TEMPERATURES WILL BE WARMER THAN NORMAL FOR MUCH OF THE NEXT WEEK
OR TWO.
&&
.NEAR TERM /UNTIL 2 PM THIS AFTERNOON/...
AREAS OF DENSE...FREEZING FOG BLANKETING THE DEEPER VALLEYS IN THE
CENTRAL MTNS REGION...WILL GRADUALLY BURN OFF THROUGH MID DAY. THE
EXCEPTION WILL BE THE LOWER SUSQ WHERE THE EXPERIMENTAL HRRR SHOWS
THE LOW CLOUDS HANGING ON WELL INTO THE DAY.
HAVE EXTENDED THE ADVISORY FOR FOG THROUGH NOON TO COVER THE SLOW
BURN OFF. OTHER THAN POCKETS OF PATCHY DRIZZLE/FREEZING
DRIZZLE...THE CHANCES FOR RAIN WILL REMAIN VERY LOW UNTIL LATER
TODAY OR THIS EVENING AS SHOWERS ASSOCIATED WITH A DYING COLD
FRONT BEGIN TO THREATEN MY FAR NWRN ZONES.
&&
.SHORT TERM /2 PM THIS AFTERNOON THROUGH 6 PM THURSDAY/...
THE MORNING FOG WILL BE SLOW TO DISSIPATE...BUT INCREASING
BOUNDARY LAYER FLOW AHEAD OF ANOTHER SHEARING UPPER WAVE AND
AMPLIFYING UPPER FLOW MAY FINALLY HELP SCOUR THINGS OUT LATE THIS
AFTERNOON /MORE THAN WE`VE SEEN IN A FEW DAYS/.
SOME BREAKS OF MID TO LATE AFTERNOON SUN ARE POSSIBLE...THANKS IN
PART TO WARMING TEMPS ALOFT AND INCREASING SOUTHERLY FLOW.
MAX TEMPS SHOULD ONLY REACH THE MID 40S ACRS MUCH OF THE CENTRAL
AND NRN MTNS...WHILE NEARING THE 50F MARK ACROSS THE SE ZONES. THE
MERCURY MAY HAVE DIFFICULTY RISING ABOVE 40F OVER THE MTNS NORTH
OF KIPT.
MOISTURE INCREASES SUFFICIENTLY AHEAD OF APPROACHING SHORTWAVE AND
WEAK SFC CFRONT TO INTRODUCE A CHANCE OF SHOWERS BY THIS EVENING
ACROSS THE NW MTNS. ELSEWHERE...NO MENTION OF PRECIP OUTSIDE OF
THE PREVIOUSLY NOTED PATCHY DRIZZLE /MAINLY ON THE SOUTH-SE FACING
SLOPES OF THE RIDGES/.
WILL HAVE TO CLOSELY MONITOR THE REGION NEAR AND TO THE EAST OF
THE SUSQ MAINSTEM WHERE ABUNDANT LLVL MOISTURE COULD ONCE AGAIN
STAY TRAPPED BENEATH A FAIRLY STRONG SFC BASED INVERSION...AND
LEAD TO WIDESPREAD LOW CLOUDS AND AREAS OF DENSE FOG. ON THE
POSITIVE SIDE...AT LEAST MIN TEMPS EARLY THURSDAY WILL BE IN THE
MID TO UPPER 30S...NEGATING THE CHC FOR FREEZING FOG.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE MAIN STORY FOR THE LONG TERM CONTINUES TO BE UNSEASONABLY
MILD WEATHER...AS WE EXPECT TEMPERATURES ARE EXPECTED TO REMAIN
ABOVE- NORMAL RIGHT INTO EARLY NEXT WEEK.
AS FOR PRECIPITATION...A WEAKENING TROUGH OF LOW PRESSURE COULD
BRING A FEW SHOWERS ACROSS CENTRAL PA WED NIGHT INTO THU...WITH
ANOTHER TROUGH PROVIDING A SLIGHT CHC FOR SHOWERS ACROSS MAINLY
THE NORTH AND WEST THU NITE INTO FRI.
SATURDAY INTO SUNDAY WILL SEE A SIGNIFICANT UPPER-LEVEL RIDGE
BUILD OVER THE EAST COAST. INCREASINGLY SOUTHERLY FLOW SHOULD
BRING IN EVEN MILDER TEMPERATURES THIS WEEKEND...WITH SOME
LOCATIONS SEEING AFTERNOON HIGHS APPROACHING 20 DEGREES ABOVE-
NORMAL.
A MORE SIGNIFICANT STORM SYSTEM WILL TRACK ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND MONDAY INTO TUESDAY...DRAGGING A COLD FRONT
ACROSS CENTRAL PA. THIS SYSTEM WILL BE ACCOMPANIED BY A PERIOD OF
SHOWERY WEATHER...AND FOLLOWED BY A COOL-DOWN BY THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
WITH THE EXCEPTION OF BFD/JST...LOW CLOUDS AND DENSE FOG CONTINUE
TO PLAGUE CENTRAL AND EASTERN PA TERMINALS.
HRRR SHOWS THE LOW CLOUDS OVER CENTRAL PA FINALLY BEGINNING TO
BREAK UP BY EARLY AFTERNOON...WITH THE LOW CLOUDS HANGING TOUGH
OVER THE LOWER SUSQ VALLEY.
WINDS WILL GENERALLY BE LIGHT...WITH SPEEDS OVER THE NW MOUNTAINS
INCREASING TO AROUND 8-10KT THIS AFTERNOON AHEAD OF AN
APPROACHING WEAK TROUGH THAT WILL LIFT THROUGH TONIGHT.
WEAK TROUGH LIFTING SW-NE OVER THE REGION TONIGHT WILL BRING AN
INFLUX OF LOW-LEVEL MOISTURE TO WESTERN AND CENTRAL PA. THIS WILL
BRING A SOLID AREA OF CIG RESTRICTIONS TO WESTERN SECTIONS ALONG
WITH SOME LIGHT RAIN SHOWERS. OVER MY SOUTHEASTERN TERMINALS
...THIS MOISTURE UNDER THE RETREATING INVERSION LOOKS TO KEEP LOW
CLOUDS AND AREAS OF FOG LOCKED IN.
OUTLOOK...
THU...MORNING FOG/RESTRICTIONS. IMPROVEMENT IN THE AFT...WITH MVFR
CIGS NW HALF AND VFR SE.
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT-SUN...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL NOON EST TODAY FOR PAZ012-017>019-
025>028-034-035-041-045-046-049-050.
&&
$$
SYNOPSIS...LA CORTE/LAMBERT
NEAR TERM...LA CORTE/LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...LA CORTE/RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
719 AM EST WED DEC 9 2015
.SYNOPSIS...
A HIGH STAGNANT RIDGE OF HIGH PRESSURE WILL BRING YET ANOTHER
FOGGY MORNING TO A LARGE PART OF CENTRAL PA. A SERIES OF LOW
PRESSURE SYSTEMS WILL TRACK WELL WEST OF PA LATE IN THE WEEK AS AN
ANOMALOUS UPPER RIDGE BUILDS ALONG THE EAST COAST. TEMPERATURES
WILL BE WARMER THAN NORMAL FOR MUCH OF THE NEXT WEEK OR TWO.
&&
.NEAR TERM /UNTIL 2 PM THIS AFTERNOON/...
AREAS OF DENSE...FREEZING FOG BLANKETING THE DEEPER VALLEYS IN THE
CENTRAL MTNS REGION...WILL GRADUALLY EXPAND OUTWARD EARLY
TODAY...CREATING A FAIRLY LARGE AREA OF VERY HAZARDOUS TRAVEL.
10Z TEMPS AND DEWPOINTS /IN THE MID 20S TO AROUND 30F/ ARE NEARLY
IDENTICAL IN MANY LOCATIONS TO THOSE EARLY TUESDAY. HOWEVER...
SLIGHTLY HIGHER MOISTURE IS BEING INJECTED/ADVECTED NWD WITHIN A
FEW TENS OF MB AGL /AND THROUGHOUT A LARGE DEPTH OF THE PERSISTENT
SFC- BASED INVERSION/.
THE DENSE FREEZING FOG ENTRENCHED IN THE CENTRAL MTNS AND SUSQ
WEST BRANCH VALLEYS WILL JUST SLOWLY LIFT A FEW TO SVRL HUNDRED
FEET LATE THIS MORNING INTO THIS AFTERNOON...POSSIBLY REQUIRED AN
ADJUSTMENT/EXTENSION/TRANSITION BACK TO A PLAIN OLD DENSE FOG
ADVISORY IN THOSE LOCATIONS.
THE SATURATED LAYER WILL DEEPEN UP TO NEARLY 2 KFT AGL INTO AT
LEAST EARLY THIS AFTERNOON...POSSIBLY ENOUGH TO PRODUCE SOME
LIGHT DRIZZLE /PER LATEST SREF/NAM AND GFS SOUNDINGS. HRRR AND RAP
DATA IS SLIGHTLY MORE OPTIMISTIC WITH THE MOISTURE DEPTH
DECREASING BY LATE THIS MORNING AND THE T/TD SPREAD INCREASING A
FEW DEG C...WHICH WOULD CAUSE EARLIER DISSIPATION OF THE DENSE
FOG.
INCREASED AND EXPANDED CLOUD COVER TO PAINT MORE OF A CLOUDY
LATE MORNING AND EARLY AFTERNOON THROUGHOUT THE CENTRAL MTNS.
&&
.SHORT TERM /2 PM THIS AFTERNOON THROUGH 6 PM THURSDAY/...
THE MORNING FOG WILL BE SLOW TO DISSIPATE...BUT INCREASING
BOUNDARY LAYER FLOW AHEAD OF ANOTHER SHEARING UPPER WAVE AND
AMPLIFYING UPPER FLOW MAY FINALLY HELP SCOUR THINGS OUT LATE THIS
AFTERNOON /MORE THAN WE/VE SEEN IN A FEW DAYS/.
SOME BREAKS OF MID TO LATE AFTERNOON SUN ARE POSSIBLE...THANKS IN
PART TO WARMING TEMPS ALOFT AND INCREASING SOUTHERLY FLOW.
MAX TEMPS SHOULD ONLY REACH THE MID 40S ACRS MUCH OF THE CENTRAL
AND NRN MTNS...WHILE NEARING THE 50F MARK ACROSS THE SE ZONES. THE
MERCURY MAY HAVE DIFFICULTY RISING ABOVE 40F OVER THE MTNS NORTH
OF KIPT.
MOISTURE INCREASES SUFFICIENTLY AHEAD OF APPROACHING SHORTWAVE AND
WEAK SFC CFRONT TO INTRODUCE A CHANCE OF SHOWERS BY THIS EVENING
ACROSS THE NW MTNS. ELSEWHERE...NO MENTION OF PRECIP OUTSIDE OF
THE PREVIOUSLY NOTED PATCHY DRIZZLE /MAINLY ON THE SOUTH-SE FACING
SLOPES OF THE RIDGES/.
WILL HAVE TO CLOSELY MONITOR THE REGION NEAR AND TO THE EAST OF
THE SUSQ MAINSTEM WHERE ABUNDANT LLVL MOISTURE COULD ONCE AGAIN
STAY TRAPPED BENEATH A FAIRLY STRONG SFC BASED INVERSION...AND
LEAD TO WIDESPREAD LOW CLOUDS AND AREAS OF DENSE FOG. ON THE
POSTITIVE SIDE...AT LEAST MIN TEMPS EARLY THURSDAY WILL BE IN THE
MID TO UPPER 30S...NEGATING THE CHC FOR FREEZING FOG.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE MAIN STORY FOR THE LONG TERM CONTINUES TO BE UNSEASONABLY
MILD WEATHER...AS WE EXPECT TEMPERATURES ARE EXPECTED TO REMAIN
ABOVE- NORMAL RIGHT INTO EARLY NEXT WEEK.
AS FOR PRECIPITATION...A WEAKENING TROUGH OF LOW PRESSURE COULD
BRING A FEW SHOWERS ACROSS CENTRAL PA WED NIGHT INTO THU...WITH
ANOTHER TROUGH PROVIDING A SLIGHT CHC FOR SHOWERS ACROSS MAINLY
THE NORTH AND WEST THU NITE INTO FRI.
SATURDAY INTO SUNDAY WILL SEE A SIGNIFICANT UPPER-LEVEL RIDGE
BUILD OVER THE EAST COAST. INCREASINGLY SOUTHERLY FLOW SHOULD
BRING IN EVEN MILDER TEMPERATURES THIS WEEKEND...WITH SOME
LOCATIONS SEEING AFTERNOON HIGHS APPROACHING 20 DEGREES ABOVE-
NORMAL.
A MORE SIGNIFICANT STORM SYSTEM WILL TRACK ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND MONDAY INTO TUESDAY...DRAGGING A COLD FRONT
ACROSS CENTRAL PA. THIS SYSTEM WILL BE ACCOMPANIED BY A PERIOD OF
SHOWERY WEATHER...AND FOLLOWED BY A COOL-DOWN BY THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
EVEN THOUGH HIGH PRESSURE AREA DRIFTING EASTWARD...LOW LEVEL
INVERSION REMAINS IN PLACE BRINGING ANOTHER MORNING OF VLIFR TO
IFR RESTRICTIONS TO MANY TERMINALS. THICKEST FOG OVERNIGHT HAS
IMPACTED KAOO-KUNV WITH NEAR ZERO VISIBILITIES. LOW CIGS OVER KIPT
SHOULD LOWER TO THE SURFACE AROUND SUNRISE BRINGING SEVERAL HOURS
OF DENSE FOG THERE TOO. NO LOW CLOUDS OVER THE SE AT KMDT-KLNS
AND UP OVER THE NW IN KBFD...BUT A SHORT-LIVED PERIOD OF VIS
REDUCTIONS LIKELY DEVELOPING THERE AS WELL THROUGH ABOUT 15Z. OVER
CENTRAL AREAS...FOG WILL BE LONGER LIVED - POTENTIALLY LASTING
INTO THE EARLY AFTERNOON WITH CIG RESTRICTIONS LIKELY PERSISTING
THROUGH THE DAY. WINDS WILL GENERALLY BE LIGHT...WITH SPEEDS OVER
THE NW MTNS INCREASING TO AROUND 8-10KTS OVER THE NW MTNS THIS
AFTERNOON AHEAD OF AN APPROACHING WEAK TROUGH THAT WILL LIFT
THROUGH TONIGHT.
WEAK TROUGH LIFTING SW-NE OVER THE REGION TONIGHT WILL BRING AN
INFLUX OF LOW-LEVEL MOISTURE TO CENTRAL PA. THIS WILL BRING A
SOLID AREA OF CIG RESTRICTIONS TO WESTERN SECTIONS ALONG WITH SOME
LIGHT RAIN SHOWERS. OVER CENTRAL AND EAST...THIS INFUSION OF LL
MOISTURE UNDER THE RETREATING INVERSION LOOKS TO AGAIN PRODUCE
AREAS OF POTENTIALLY DENSE FOG AND LOW CIGS...ESP FROM KIPT-
KMDT/KLNS. NAM AND SREF BOTH INDICATING THIS PRETTY STRONGLY AND
MODEL SOUNDINGS SUPPORT THIS LINE OF THINKING.
OUTLOOK...
THU...MORNING FOG/RESTRICTIONS. IMPROVEMENT IN THE AFT...WITH MVFR
CIGS NW HALF AND VFR SE.
FRI...AREAS OF MORNING FOG. THEN MAINLY VFR.
SAT-SUN...MVFR WITH CHC SHRA NW HALF. MAINLY VFR SE.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ012-
017>019-025>028-034-035-041-045-046-049-050.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
542 AM EST WED DEC 9 2015
.SYNOPSIS...
A HIGH STAGNANT RIDGE OF HIGH PRESSURE WILL BRING YET ANOTHER
FOGGY MORNING TO A LARGE PART OF CENTRAL PA. A SERIES OF LOW
PRESSURE SYSTEMS WILL TRACK WELL WEST OF PA LATE IN THE WEEK AS AN
ANOMALOUS UPPER RIDGE BUILDS ALONG THE EAST COAST. TEMPERATURES
WILL BE WARMER THAN NORMAL FOR MUCH OF THE NEXT WEEK OR TWO.
&&
.NEAR TERM /UNTIL 2 PM THIS AFTERNOON/...
AREAS OF DENSE...FREEZING FOG BLANKETING THE DEEPER VALLEYS IN THE
CENTRAL MTNS REGION...WILL GRADUALLY EXPAND OUTWARD EARLY
TODAY...CREATING A FAIRLY LARGE AREA OF VERY HAZARDOUS TRAVEL.
10Z TEMPS AND DEWPOINTS /IN THE MID 20S TO AROUND 30F/ ARE NEARLY
IDENTICAL IN MANY LOCATIONS TO THOSE EARLY TUESDAY. HOWEVER...
SLIGHTLY HIGHER MOISTURE IS BEING INJECTED/ADVECTED NWD WITHIN A
FEW TENS OF MB AGL /AND THROUGHOUT A LARGE DEPTH OF THE PERSISTENT
SFC- BASED INVERSION/.
THE DENSE FREEZING FOG ENTRENCHED IN THE CENTRAL MTNS AND SUSQ
WEST BRANCH VALLEYS WILL JUST SLOWLY LIFT A FEW TO SVRL HUNDRED
FEET LATE THIS MORNING INTO THIS AFTERNOON...POSSIBLY REQUIRED AN
ADJUSTMENT/EXTENSION/TRANSITION BACK TO A PLAIN OLD DENSE FOG
ADVISORY IN THOSE LOCATIONS.
THE SATURATED LAYER WILL DEEPEN UP TO NEARLY 2 KFT AGL INTO AT
LEAST EARLY THIS AFTERNOON...POSSIBLY ENOUGH TO PRODUCE SOME
LIGHT DRIZZLE /PER LATEST SREF/NAM AND GFS SOUNDINGS. HRRR AND RAP
DATA IS SLIGHTLY MORE OPTIMISTIC WITH THE MOISTURE DEPTH
DECREASING BY LATE THIS MORNING AND THE T/TD SPREAD INCREASING A
FEW DEG C...WHICH WOULD CAUSE EARLIER DISSIPATION OF THE DENSE
FOG.
INCREASED AND EXPANDED CLOUD COVER TO PAINT MORE OF A CLOUDY
LATE MORNING AND EARLY AFTERNOON THROUGHOUT THE CENTRAL MTNS.
&&
.SHORT TERM /2 PM THIS AFTERNOON THROUGH 6 PM THURSDAY/...
THE MORNING FOG WILL BE SLOW TO DISSIPATE...BUT INCREASING
BOUNDARY LAYER FLOW AHEAD OF ANOTHER SHEARING UPPER WAVE AND
AMPLIFYING UPPER FLOW MAY FINALLY HELP SCOUR THINGS OUT LATE THIS
AFTERNOON /MORE THAN WE/VE SEEN IN A FEW DAYS/.
SOME BREAKS OF MID TO LATE AFTERNOON SUN ARE POSSIBLE...THANKS IN
PART TO WARMING TEMPS ALOFT AND INCREASING SOUTHERLY FLOW.
MAX TEMPS SHOULD ONLY REACH THE MID 40S ACRS MUCH OF THE CENTRAL
AND NRN MTNS...WHILE NEARING THE 50F MARK ACROSS THE SE ZONES. THE
MERCURY MAY HAVE DIFFICULTY RISING ABOVE 40F OVER THE MTNS NORTH
OF KIPT.
MOISTURE INCREASES SUFFICIENTLY AHEAD OF APPROACHING SHORTWAVE AND
WEAK SFC CFRONT TO INTRODUCE A CHANCE OF SHOWERS BY THIS EVENING
ACROSS THE NW MTNS. ELSEWHERE...NO MENTION OF PRECIP OUTSIDE OF
THE PREVIOUSLY NOTED PATCHY DRIZZLE /MAINLY ON THE SOUTH-SE FACING
SLOPES OF THE RIDGES/.
WILL HAVE TO CLOSELY MONITOR THE REGION NEAR AND TO THE EAST OF
THE SUSQ MAINSTEM WHERE ABUNDANT LLVL MOISTURE COULD ONCE AGAIN
STAY TRAPPED BENEATH A FAIRLY STRONG SFC BASED INVERSION...AND
LEAD TO WIDESPREAD LOW CLOUDS AND AREAS OF DENSE FOG. ON THE
POSTITIVE SIDE...AT LEAST MIN TEMPS EARLY THURSDAY WILL BE IN THE
MID TO UPPER 30S...NEGATING THE CHC FOR FREEZING FOG.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE MAIN STORY FOR THE LONG TERM CONTINUES TO BE UNSEASONABLY
MILD WEATHER...AS WE EXPECT TEMPERATURES ARE EXPECTED TO REMAIN
ABOVE- NORMAL RIGHT INTO EARLY NEXT WEEK.
AS FOR PRECIPITATION...A WEAKENING TROUGH OF LOW PRESSURE COULD
BRING A FEW SHOWERS ACROSS CENTRAL PA WED NIGHT INTO THU...WITH
ANOTHER TROUGH PROVIDING A SLIGHT CHC FOR SHOWERS ACROSS MAINLY
THE NORTH AND WEST THU NITE INTO FRI.
SATURDAY INTO SUNDAY WILL SEE A SIGNIFICANT UPPER-LEVEL RIDGE
BUILD OVER THE EAST COAST. INCREASINGLY SOUTHERLY FLOW SHOULD
BRING IN EVEN MILDER TEMPERATURES THIS WEEKEND...WITH SOME
LOCATIONS SEEING AFTERNOON HIGHS APPROACHING 20 DEGREES ABOVE-
NORMAL.
A MORE SIGNIFICANT STORM SYSTEM WILL TRACK ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND MONDAY INTO TUESDAY...DRAGGING A COLD FRONT
ACROSS CENTRAL PA. THIS SYSTEM WILL BE ACCOMPANIED BY A PERIOD OF
SHOWERY WEATHER...AND FOLLOWED BY A COOL-DOWN BY THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION /12Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE ALONG THE ATLC COAST WILL PROVIDE GENERALLY CLEAR
SKIES AND LIGHT WINDS THIS EVENING...ALLOWING REDEVELOPMENT OR
THICKENING OF LOW FOG/LOW LEVEL CIGS ESPECIALLY AT LOCATIONS THAT
REMAINED LOW TODAY. AREA OF MID CLOUDS WILL SPREAD WEST TO EAST
OVERNIGHT AHEAD OF WEATHER SYSTEM OVER THE PLAINS. THIS MAY HELP
TO DISRUPT LOWER CONDS...AT LEAST TEMPORARILY OVERNIGHT.
SLOW IMPROVEMENT IS EXPECTED WEDNESDAY AS SFC WINDS INCREASE AHD
OF THE APPROACHING WEATHER SYSTEM. THIS SYSTEM WILL BRING SHOWERS
TO THE REGION WED NIGHT.
OUTLOOK...
TUE NIGHT-WED NIGHT...CHANCE FOR MVFR CIGS.
THU-FRI...MVFR POSS NW.
SAT...MVFR WITH CHC SHRA.
SUN...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ012-
017>019-025>028-034-035-041-045-046-049-050.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT
SHORT TERM...LAMBERT
LONG TERM...EVANEGO
AVIATION...DEVOIR/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
247 AM EST WED DEC 9 2015
.SYNOPSIS...
A HIGH STAGNANT RIDGE OF HIGH PRESSURE WILL BRING YET ANOTHER
FOGGY MORNING TO A LARGE PART OF CENTRAL PA. A SERIES OF LOW
PRESSURE SYSTEMS WILL TRACK WELL WEST OF PA LATE IN THE WEEK AS AN
ANOMALOUS UPPER RIDGE BUILDS ALONG THE EAST COAST. TEMPERATURES
WILL BE WARMER THAN NORMAL FOR MUCH OF THE NEXT WEEK OR TWO.
&&
.NEAR TERM /UNTIL 10 AM THIS MORNING/...
AREAS OF DENSE...FREEZING FOG BLANKETING THE DEEPER VALLEYS IN THE
CENTRAL MTNS REGION...WILL GRADUALLY EXPAND OUTWARD EARLY
TODAY...CREATING A FAIRLY LARGE AREA OF VERY HAZARDOUS TRAVEL.
TEMPS AND DEWPOINTS ARE NEARLY IDENTICAL TO LAST NIGHT AT THIS
TIME IN MANY LOCATIONS. HOWEVER...SLIGHTLY HIGHER MOISTURE IS
BEING INJECTED/ADVECTED NWD WITHIN A FEW TENS OF MB AGL /AND
THROUGHOUT A LARGE DEPTH OF THE PERSISTENT SFC-BASED INVERSION/.
THE DENSE FREEZING FOG ENTRENCHED IN THE CENTRAL MTNS AND SUSQ
WEST BRANCH VALLEYS WILL JUST SLOWLY LIFT A FEW TO SVRL HUNDRED
FEET LATE THIS MORNING INTO THIS AFTERNOON...POSSIBLY REQUIRED AN
ADJUSTMENT/EXTENSION/TRANSITION BACK TO A PLAIN OLD DENSE FOG
ADVISORY IN THOSE LOCATIONS.
THE SATURATED LAYER WILL DEEPEN UP TO NEARLY 2 KFT AGL INTO AT
LEAST EARLY THIS AFTERNOON...POSSIBLY ENOUGH TO PRODUCE SOME
LIGHT DRIZZLE /PER LATEST SREF/NAM AND GFS SOUNDINGS. HRRR AND RAP
DATA IS SLIGHTLY MORE OPTIMISTIC WITH THE MOISTURE DEPTH
DECREASING BY LATE THIS MORNING AND THE T/TD SPREAD INCREASING A
FEW DEG C...WHICH WOULD CAUSE EARLIER DISSIPATION OF THE DENSE
FOG.
INCREASED AND EXPANDED CLOUD COVER TO PAINT MORE OF A CLOUDY
LATE MORNING AND EARLY AFTERNOON THROUGHOUT THE CENTRAL MTNS.
MAX TEMPS SHOULD ONLY REACH THE MID 40S ACRS MUCH OF THE CENTRAL
AND NRN MTNS...WHILE NEARING THE 50F MARK ACROSS THE SE ZONES.
&&
.SHORT TERM /10 AM THIS MORNING THROUGH 6 PM THURSDAY/...
THIS MORNING`S FOG WILL BE SLOW TO DISSIPATE...BUT INCREASING
BOUNDARY LAYER FLOW AHEAD OF ANOTHER SHEARING UPPER WAVE AND
AMPLIFYING UPPER FLOW MAY FINALLY HELP SCOUR THINGS OUT LATE THIS
AFTERNOON /MORE THAN WE/VE SEEN IN A FEW DAYS/.
SOME BREAKS OF MID TO LATE AFTERNOON SUN AND WARMING TEMPS ALOFT
SHOULD PUSH READINGS TO BTWN 45-50F ACROSS THE REGION BY AFTN.
MOISTURE INCREASES SUFFICIENTLY AHEAD OF APPROACHING SHORTWAVE TO
INTRODUCE A CHANCE OF SHOWERS BY THIS EVENING ACROSS THE NW MTNS.
ELSEWHERE...NO MENTION OF PRECIP OUTSIDE OF THE PREVIOUSLY NOTED
PATCHY DRIZZLE /MAINLY ON THE SOUTH-SE FACING SLOPES OF THE
RIDGES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
THE MAIN STORY FOR THE LONG TERM IS UNSEASONABLY MILD
WEATHER...AS WE EXPECT TEMPERATURES ARE EXPECTED TO REMAIN ABOVE-
NORMAL RIGHT INTO EARLY NEXT WEEK.
AS FOR PRECIPITATION...A WEAKENING TROUGH OF LOW PRESSURE COULD
BRING A FEW SHOWERS ACROSS CENTRAL PA WED NIGHT INTO THU...WITH
ANOTHER TROUGH PROVIDING A SLIGHT CHC FOR SHOWERS ACROSS MAINLY
THE NORTH AND WEST THU NITE INTO FRI.
SATURDAY INTO SUNDAY WILL SEE A SIGNIFICANT UPPER-LEVEL RIDGE
BUILD OVER THE EAST COAST. INCREASINGLY SOUTHERLY FLOW SHOULD
BRING IN EVEN MILDER TEMPERATURES THIS WEEKEND...WITH SOME
LOCATIONS SEEING AFTERNOON HIGHS APPROACHING 20 DEGREES ABOVE-
NORMAL.
A MORE SIGNIFICANT STORM SYSTEM WILL TRACK ACROSS THE GREAT LAKES
AND INTO NEW ENGLAND MONDAY INTO TUESDAY...DRAGGING A COLD FRONT
ACROSS CENTRAL PA. THIS SYSTEM WILL BE ACCOMPANIED BY A PERIOD OF
SHOWERY WEATHER...AND FOLLOWED BY A COOL-DOWN BY THE MIDDLE OF
NEXT WEEK.
&&
.AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
HIGH PRESSURE ALONG THE ATLC COAST WILL PROVIDE GENERALLY CLEAR
SKIES AND LIGHT WINDS THIS EVENING...ALLOWING REDEVELOPMENT OR
THICKENING OF LOW FOG/LOW LEVEL CIGS ESPECIALLY AT LOCATIONS THAT
REMAINED LOW TODAY. AREA OF MID CLOUDS WILL SPREAD WEST TO EAST
OVERNIGHT AHEAD OF WEATHER SYSTEM OVER THE PLAINS. THIS MAY HELP
TO DISRUPT LOWER CONDS...AT LEAST TEMPORARILY OVERNIGHT.
SLOW IMPROVEMENT IS EXPECTED WEDNESDAY AS SFC WINDS INCREASE AHD
OF THE APPROACHING WEATHER SYSTEM. THIS SYSTEM WILL BRING SHOWERS
TO THE REGION WED NIGHT.
OUTLOOK...
TUE NIGHT-WED NIGHT...CHANCE FOR MVFR CIGS.
THU-FRI...MVFR POSS NW.
SAT...MVFR WITH CHC SHRA.
SUN...VFR.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR PAZ012-
017>019-025>028-034-035-041-045-046-049-050.
&&
$$
SYNOPSIS...LAMBERT
NEAR TERM...LAMBERT/FITZGERALD
SHORT TERM...LAMBERT/FITZGERALD
LONG TERM...EVANEGO
AVIATION...DEVOIR/GARTNER
AREA FORECAST DISCUSSION
NWS ABERDEEN SD
304 PM CST WED DEC 9 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 243 PM CST WED DEC 9 2015
A FAIRLY ACTIVE PATTERN WITH 2 WEAK SYSTEMS DURING THE SHORT TERM.
HRRR AND RUC BOTH BRING LIGHT PRECIPITATION INTO THE WESTERN CWA
THIS EVENING...WITH PROFILES SUPPORTING A BRIEF PERIOD OF LIGHT RAIN
AHEAD OF THIS WAVE ONCE SATURATION IS ACHIEVED...THUS NOT EXPECTING
MUCH MORE THAN A HUNDREDTH OR TWO. SURFACE TEMPERATURES WILL LIKELY
REMAIN ABOVE FREEZING WITH 925MB TEMPERATURES AROUND +6C AND A
PREDOMINANT WEST WIND. THIS WIND WILL ALSO INCREASE TOWARDS MORNING
WITH 1/2KM WINDS UPWARDS OF 50KTS...HOWEVER BECAUSE OF THE DEGREE OF
COLD ADVECTION...LOW VALUES FOR PRESSURE RISES...AND A 10 TO 12MB
PRESSURE GRADIENT ACROSS THE STATE...ANTICIPATE IT WILL BE DIFFICULT
TO FULLY REALIZE THESE STRONGER WINDS. WILL LEAVE CURRENT HEADLINE
IN PLACE WITH THE REST OF THE CWA POSSIBLY SEEING A FEW GUSTS NEAR
ADVISORY CRITERIA DURING PEAK HEATING.
THE SECOND WEAK WAVE MOVES IN FOR EARLY FRIDAY. WARM ADVECTION WILL
GENERATE ENOUGH LIFT FOR LIGHT PRECIPITATION ALONG AND JUST NORTH OF
THE NORTH DAKOTA/SOUTH DAKOTA STATE LINE DURING THE MORNING
HOURS...BUT AS THE WAVE CONTINUES TO SHEAR APART...PRECIPITATION
INTENSITY WILL LIKELY DROP THROUGH THE MID DAY HOURS. PROFILES ARE
MAINLY SUPPORTIVE OF SNOW...WITH GUIDANCE ESTIMATING AROUND AN INCH
OR TWO JUST NORTH OF THE CWA.
.LONG TERM...(SATURDAY THROUGH WEDNESDAY)
ISSUED AT 243 PM CST WED DEC 9 2015
PRECIPITATION CHANCES THIS WEEKEND...AND AGAIN TUESDAY THROUGH
WEDNESDAY WILL BE THE FORECAST CHALLENGES.
THE PERIOD BEGINS WITH AN UPPER LEVEL TROUGH OF LOW PRESSURE
CROSSING THE CENTRAL CONUS. WHILE ALL MODELS SHOW THIS TROUGH...THEY
DIFFER ON THE PLACEMENT OF THE PCPN. THE MODEL RUNS FROM LAST
NIGHT...WHICH SHOWED DRY CONDITIONS PER THE ECMWF/GEM...HAVE FLIPPED
WITH THE 12Z RUN. THE GFS NOW KEEPS THE CWA DRY...WHILE THE
ECMWF/GEM BRINGS LIGHT SNOW TO THE EASTERN HALF OF THE CWA SATURDAY
THROUGH SUNDAY MORNING. PREFERRED A DRY SOLUTION FOR THE WEEKEND
BASED ON THE NAEFS...WHICH SHOWS A MORE SOUTHEASTERLY SOLUTION.
AFTER A MOSTLY DRY SUNDAY AND MONDAY...MODELS AGREE FAIRLY WELL WITH
A STORM SYSTEM IMPACTING THE REGION TUESDAY THROUGH WEDNESDAY. THIS
STORM COULD BRING WIDESPREAD ACCUMULATING SNOWFALL TO THE REGION. OF
COURSE IT IS FAR TOO SOON TO TALK SNOWFALL AMOUNTS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1132 AM CST WED DEC 9 2015
A WARM FRONT CROSSING THE REGION TODAY WILL SHIFT THE WINDS TO A
WESTERLY DIRECTION. THE WESTERLY WINDS WILL CONTINUE THROUGH THE
VALID TAF PERIOD. EXPECT THE WINDS TO INCREASE FROM WEST TO EAST
ACROSS THE REGION WITH SUSTAINED WINDS OF 20 KNOTS POSSIBLE FOR
ALL TERMINALS ON THURSDAY. A SYSTEM CROSSING THE REGION TONIGHT
COULD BRING VCSH TO MOST TERMINALS. HOWEVER CONDITIONS SHOULD
REMAIN VFR THROUGH THE TAF PERIOD.
&&
.ABR WATCHES/WARNINGS/ADVISORIES...
SD...WIND ADVISORY FROM 5 AM TO 2 PM MST THURSDAY FOR SDZ003-015.
MN...NONE.
&&
$$
SHORT TERM...CONNELLY
LONG TERM...SD
AVIATION...SD
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
300 PM EST WED DEC 9 2015
.SHORT TERM (TONIGHT THROUGH TOMORROW)...
CURRENT WATER VAPOR IMAGERY AND RAP UPPER AIR ANALYSIS INDICATES A
SHORTWAVE TROUGH ACROSS THE OHIO AND TENNESSEE RIVER VALLEYS. AT THE
SURFACE...A COLD FRONT/SURFACE TROUGH IS MOVING INTO MIDDLE
TENNESSEE. WIDESPREAD CLOUD COVER EXIST AHEAD OF THIS SURFACE
BOUNDARY DUE TO LOW LEVEL ISENTROPIC LIFT. VISIBLE SATELLITE
IMAGERY INDICATES RATHER WIDESPREAD CLOUD COVER BACK TO THE WEST
AHEAD OF THIS BOUNDARY. LOOKING AT THE RADAR...NOT SEEING MUCH IN
THE WAY OF PRECIPITATION SHOWING UP AND HAVE ONLY SEEN AN OB OR 2
REPORT LIGHT RAIN. THEREFORE...WENT AHEAD AND REDUCED POPS
SOMEWHAT FOR THIS EVENING/OVERNIGHT WITH POPS AROUND 20-30. HI-
RES MODELS INDICATE SCATTERED SHOWERS DEVELOPING AHEAD OF THIS
BOUNDARY BUT SEEM TO BE A BIT OVERDONE BASED ON THE CURRENT RADAR
TRENDS. REGARDLESS...ANY PRECIPITATION WILL BE LIGHT WITH ONLY THE
LOWEST 100-150 MB SATURATED. WIDESPREAD CLOUD COVER AND SOUTHERLY
FLOW WILL KEEP LOW TEMPERATURES TONIGHT UP IN THE 40S.
NOT A BIG CHANGE IN OVERALL CONDITIONS AS THE TROUGH PASSES TO THE
WEST. LOW LEVEL FLOW BEHIND THE TROUGH REMAINS SOUTHERLY TO
SOUTHWESTERLY AND COULD SEE CLOUD COVER HOLD IN ACROSS THE EASTERN
AREAS NEAR THE MOUNTAINS THROUGHOUT MUCH OF THE DAY TOMORROW.
FURTHER TO THE WEST...EXPECT CLOUDS WILL BEGIN TO DECREASE BY THE
AFTERNOON. HIGH TEMPERATURES WILL REMAIN ABOVE NORMAL WITH HIGHS IN
THE 50S AND 60S.
.LONG TERM (THURSDAY NIGHT THROUGH WEDNESDAY)...
QUIET CONDITIONS TO BEGIN THE LONG TERM AS MOSTLY ZONAL FLOW IS IN
PLACE THROUGH FRIDAY. OVERNIGHT LOWS THURSDAY WILL BE ABOUT 10
DEGREES ABOVE NORMAL. FRIDAY HIGH TEMPS WILL BE AROUND 10 DEGREES
ABOVE NORMAL AND LOWS AROUND 15 ABOVE NORMAL. 500MB HEIGHTS RAPIDLY
INCREASE ACROSS THE REGION ON SATURDAY AND SUNDAY IN ADVANCE OF A
DEEP TROUGH MOVING OUT OF THE PACIFIC NW AND INTO THE PLAINS.
MODELS STILL TRENDING TOWARD A SLOWER SYSTEM SO IT LOOKS LIKE
CONFIDENCE ON TIMING IS INCREASING. HIGH TEMPS FOR BOTH SATURDAY
AND SUNDAY WILL BE IN THE MID TO UPPER 60S WITH THE EXTREME
SOUTHERN VALLEY APPROACHING 70. THESE TEMPERATURES WILL BE AROUND
15 DEGREES ABOVE NORMAL. LOWS ON SATURDAY AND SUNDAY NIGHT WILL BE
15 TO 20 DEGREES WARMER THAN NORMAL. IN FACT...OVERNIGHT LOWS ON
FRIDAY...SATURDAY AND SUNDAY WILL BE NEAR WHAT OUR NORMAL HIGHS
SHOULD BE FOR THIS TIME OF YEAR.
BOTH THE 12Z ECMWF AND GFS SHOW THE DEEP TROUGH MOVING INTO WESTERN
TN LATE SUNDAY NIGHT AND EARLY MONDAY MORNING. THIS SYSTEM HAS QUITE
A BIT OF ENERGY WITH IT BUT WILL BE A FAST MOVER. AMPLE
MOISTURE...LIFT...AND GOOD JET STREAM DYNAMICS WILL GIVE US A CHANCE
TO SEE MODERATE TO LOCALLY HEAVY RAINS FOR THE LATE SUNDAY NIGHT
THROUGH MONDAY MORNING TIME PERIOD. PREVIOUS FORECAST INCLUDED
SLIGHT CHANCE OF THUNDER BUT CURRENT SOUNDINGS SHOW VERY LITTLE TO
NO CAPE AS THIS SYSTEM MOVES THROUGH SO OPTED TO REMOVE THUNDER FROM
FORECAST. HALF AN INCH TO THREE QUARTERS OF AN INCH OF RAIN LOOKS
POSSIBLE WITH THIS SYSTEM. TROUGH AND ASSOCIATED LOW RAPIDLY MOVE
OFF TO THE NE ON MONDAY WITH CLEARING SKIES BY MID TO LATE
AFTERNOON. RIDGING QUICKLY BUILDS BACK IN ON TUESDAY WITH
TEMPERATURES IN THE UPPER 50S TO NEAR 60. TUESDAY NIGHT INTO
WEDNESDAY OUR NEXT SYSTEM APPROACHES. THE CENTER OF THE LOW WILL BE
WELL TO OUR NORTH UP INTO THE GREAT LAKES...BUT ITS ASSOCIATED
TRAILING COLD FRONT WILL BE APPROACHING OUR AREA. TIMING WITH THIS
SYSTEM WILL LIKELY CHANGE BUT FOR NOW HAVE SLIGHT CHANCE SHOWERS
TUESDAY NIGHT WITH LOW END CHANCE ON WEDNESDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 45 64 49 66 / 10 0 0 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 46 60 47 64 / 20 0 0 10
OAK RIDGE, TN 45 61 47 64 / 20 0 10 10
TRI CITIES AIRPORT, TN 43 59 39 63 / 20 10 0 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
MA/SR
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
932 PM CST THU DEC 10 2015
.UPDATE...
WINDS ARE FINALLY EASING...THOUGH A FEW GUSTS APPROACHING ADVISORY
LEVELS ARE STILL POSSIBLE FOR THE NEXT HOUR OR SO OVER THE FAR
NORTHEAST. CLEARING SKIES ARE HELPING WITH DEVELOPING THE WEAK
BUT EFFECTIVE INVERSION SEEN ON RAP SOUNDINGS THAT SHOULD KEEP THE
STIFF WINDS JUST OFF THE SURFACE FROM REACHING THE GROUND. WILL
STILL BE SEEING WIND GUSTS IN THE 20 TO 30 KNOT RANGE THROUGH
MIDNIGHT UNTIL THE LOW LIFTS FAR ENOUGH AWAY TO THE NORTHEAST TO
PULL THE TIGHT GRADIENT OUT OF THE AREA.
WITH A RECORD HIGH TEMPERATURE FOR THE DATE ALREADY SET AT
MADISON...WE ARE ALSO STILL IN THE RUNNING FOR THE WARMEST LOW
TEMPERATURE FOR THE DATE...WHICH WAS 37F DEGREES SET IN 1899.
SO FAR THE LOWEST TEMPERATURE TODAY IS 42F DEGREES AT 214 AM.
WITH A HIGH TEMPERATURE OF 57F DEGREES...MILWAUKEE MISSED THE
RECORD HIGH TEMPERATURE RECORD OF 58F DEGREES SET IN 1911 BY ONE
DEGREE. IT DOES TIE DECEMBER 10 1879 FOR SECOND PLACE. MILWAUKEE WILL
ALSO MISS THE RECORD FOR WARMEST LOW TEMPERATURE FOR THE DATE
WHICH WAS 42F DEGREES SET IN 1911. MILWAUKEE HAS ALREADY HAD A LOW
TEMPERATURE OF 41F JUST AFTER MIDNIGHT...WHICH DOES PUT 2015 ALONE IN
SECOND PLACE...AHEAD OF THE 40F SET IN 1899.
&&
.AVIATION/06Z TAFS/...
WIND GUSTS HAVE FALLEN BELOW 30 KNOTS...THOUGH A FEW ROUGE GUSTS
TO 30 KNOTS ARE POSSIBLE IN THE FAR EAST THROUGH 06Z. EXPECT WINDS
TO STILL GUST TO BETWEEN 15 AND 25 KNOTS UNTIL THE TIGHT PRESSURE
GRADIENT CLEARS TO THE NORTHEAST WITH DEPARTING STRONG SURFACE
LOW. WITH WINDS OF 35 TO 40 KNOTS WITHIN 2K FT OF THE
SURFACE INTO THE EARLY MORNING HOURS...WILL KEEP LOW-LEVEL WIND
SHEAR IN THE FORECAST THROUGH 08Z TO 10Z.
EXPECT VFR CONDITIONS THROUGH THE FORECAST...THOUGH WILL HAVE TO
WATCH SOUTHERN EXTENT OF MVFR CLOUD DECK ROTATING THROUGH
MINNESOTA INTO NORTHWEST AND WEST CENTRAL WISCONSIN AROUND
DEPARTING LOW. SREF PROBABILITIES AND LOW LEVEL RH FORECASTS KEEP
THE LOWER CLOUDS NORTH OF TAF SITES.
&&
.MARINE...
ALLOWED THE GALE WARNING TO EXPIRE...WITH A SMALL CRAFT ADVISORY
IN EFFECT UNTIL 09Z IN THE SRN ZONES AND 11Z IN THE NORTHERN ZONES
UNTIL GUSTY SOUTHWEST TO WEST WINDS EASE WITH DEPARTING TIGHT
PRESSURE GRADIENT AS DEEP LOW CONTINUES TO PULL AWAY TO THE
NORTHEAST.
&&
.PREV DISCUSSION... /ISSUED 345 PM CST THU DEC 10 2015/
SHORT TERM...
TONIGHT AND FRIDAY...FORECAST CONFIDENCE...MEDIUM.
THE TROF OF LOW PRESSURE RESPONSIBLE FOR THE CLOUDS AND ISOLATED
SHOWERS THIS AFTERNOON WILL MOVE OUT OF THE AREA. BEHIND THE
TROF...THE MID AND LOW LEVELS OF THE ATMOSPHERE WILL DRY OUT
YIELDING CLEARING SKIES INTO THE EVENING AND OVERNIGHT HOURS. WAA
WILL ALSO KICK IN OVERNIGHT AS A RIDGE QUICKLY BUILDS INTO THE
REGION. THE LOW LEVEL WAA WILL KEEP THE OVERNIGHT INVERSION
WEAK...ALLOWING SOME WINDS FROM THE STRONG LOW LEVEL JET TO MIX DOWN
TO THE SFC. THIS WILL RESULT IN RELATIVELY WINDY CONDITIONS
OVERNIGHT AND WILL KEEP THE TEMPERATURES FROM DROPPING MUCH BELOW
THE UPPER 30S.
TOMORROW MORNING...LOW CLOUDS WRAPPING AROUND THE DEPARTING LOW WILL
ENCROACH ON THE FORECAST AREA FROM THE NORTHWEST BEFORE MOVING OFF
TO THE EAST BY MID DAY AS A WEAK RIDGE QUICKLY TRAVERSES SOUTHERN
WISCONSIN. THE RIDGE WILL EXIT THE STATE IN THE EARLY AFTERNOON AS
ANOTHER SUBTLE TROF MOVES INTO THE AREA IN THE AFTERNOON. THANKS TO
WAA AND AND ANOTHER SLUG OF MOISTURE ASSOCIATED WITH THIS
TROF...SCATTERED TO BROKEN MID CLOUDS WILL MOVE IN JUST AS THE
MORNING/S LOW CLOUDS MOVE OUT. THIS MEANS THAT DESPITE THE
PERSISTENT WAA THROUGH THE DAY...CLOUDY SKIES WILL MODERATE TEMPS
TOMORROW...KEEPING HIGHS IN THE MID 40S TO AROUND 50.
FRIDAY NIGHT THROUGH MONDAY...FORECAST CONFIDENCE MEDIUM.
A WEAK WAVE OF LOW PRESSURE WILL TRACK FROM THE MID MO RVR VALLEY
INTO SRN WI FRI NT WITH AN INVERTED SFC TROUGH LEFT IN ITS WAKE
FOR SAT. STRATUS AND CHANCES OF LGT RAIN...DRIZZLE AND FOG WILL BE
THE RESULT VIA LOW LEVEL WARM...MOIST ADVECTION AND WEAK
FRONTOGENESIS. THE MILD TEMPS WILL CONTINUE.
A SHARP UPPER TROUGH OVER THE DESERT SW WILL TRACK TO THE SRN
PLAINS FOR SUN...THEN LIFT NEWD TOWARD THE WRN GREAT LAKES FOR SUN
NT AND MON. THIS WILL TRIGGER CYCLOGENESIS FROM THE SRN PLAINS TO
LAKE SUPERIOR BY MON. A LARGE AND MOIST WARM CONVEYOR BELT WITH
PWS AROUND 1.30 INCHES WILL BRING PERIODS OF MODERATE RAINFALL
BEGINNING SAT NT AND LASTING INTO SUN NT. THE OCCLUDED FRONT WILL
PASS LATE SUN NT OR MON AM WHILE THE UPPER LOW PASSES ALOFT. THUS
SHOWERY CONDITIONS WILL LIKELY CONTINUE ON MON. LATEST RAINFALL
FORECAST RANGES FROM 1.5 INCHES IN FAR ERN WI TO 2.25 INCHES IN
THE FAR WRN CWA. THIS WILL ONCE AGAIN CAUSE RIVERS TO RISE WITH
SOME REACHING BANKFUL OR MINOR FLOOD STAGE FOR EARLY NEXT WEEK.
MILD TEMPS WILL CONTINUE WITH HIGHS ON SUN OF 55-60F.
LONG TERM...TUESDAY THROUGH THURSDAY...FORECAST CONFIDENCE
MEDIUM.
ANOTHER ROUND OF CYCLOGENESIS IS EXPECTED FROM THE CENTRAL PLAINS
TO THE LAKE SUPERIOR REGION FOR TUE-WED AS A LARGE UPPER LOW OVER
THE NORTHERN AND CENTRAL ROCKIES MOVES INTO THE NRN PLAINS. THE
CHANCES OF OF PCPN WILL REMAIN LOW AS MUCH OF THE PCPN WILL REMAIN
OVER MN AND NW WI. THIS WILL SUPPORT A CONTINUATION OF MILD
TEMPS EARLY IN THE WEEK BUT THE COLD FRONTAL PASSAGE TUE NT WILL
DROP HIGH TEMPS INTO THE 30S FOR WED. THE UPPER TROUGH PASSAGE
WILL SLOWLY OCCUR FROM WED THROUGH THU...REINFORCING THE COLD AIR
AND BRINGING SLIGHT CHANCES OF SNOW. HIGH TEMPS TO DROP INTO THE
LOWER 30S FOR THU.
AVIATION/00Z TAFS/...
IMMEDIATE CONCERN IS THE SHOWER POTENTIAL THIS AFTERNOON. CURRENT
RADAR TRENDS INDICATE THAT ISOLATED SHOWERS WILL LIKELY IMPACT
MSN...AND MAY REACH FAR ENOUGH SOUTH TO IMPACT THE OTHER TAF SITES
AS THEY MOVE OFF TO THE NORTHEAST. REGARDLESS...MVFR CIGS TO THE
WEST WILL ADVECT TO ALL THE TAF SITES BEFORE CLEARING OUT EARLY THIS
EVENING.
THE OTHER PRIMARY CONCERN IS THE POTENTIAL FOR LLWS THIS EVENING. A
45-50 KT LOW LEVEL JET WILL BE IN PLACE THROUGH THE
EVENING...ESPECIALLY OVER THE EASTER TAF SITES. HOWEVER...MODEL
SOUNDINGS INDICATE A RELATIVELY WEAK INVERSION WHICH WILL ALLOW SOME
OF THE GUSTIER WINDS TO MIX DOWN TO THE SURFACE. THEREFORE HAVE
INCLUDED GUSTS THROUGH MIDNIGHT AT MKE AND ENW RATHER THAN OF LLWS.
AT MSN AND UES...LOW LEVEL JET WILL BE WEAKER AND LLWS POTENTIAL
WILL BE LESS.
MARINE...
THE PRESSURE GRADIENT WILL SLACKEN AS LOW PRESSURE DEPARTS TO THE
NORTHEAST. HOWEVER...A LOW LEVEL JET WILL REMAIN IN PLACE OVER THE
AREA FOR MUCH OF THE EVENING...AND SOME OF THOSE GUSTY WINDS WILL
MIX DOWN TO THE SURFACE. THE GUSTS WILL GRADUALLY DIMINISH
OVERNIGHT...FALLING BELOW SCA CRITERIA BY MIDNIGHT.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 3 AM CST FRIDAY FOR LMZ645-646.
SMALL CRAFT ADVISORY UNTIL 5 AM CST FRIDAY FOR LMZ643-644.
&&
$$
UPDATE...REM
TONIGHT/FRIDAY AND AVIATION/MARINE...BSH
FRIDAY NIGHT THROUGH THURSDAY...GEHRING
AREA FORECAST DISCUSSION
NWS MIAMI FL
409 AM EST FRI DEC 11 2015
.DISCUSSION...
BROAD SURFACE HIGH PRESSURE IS OVER THE REGION. IN THE MID TO
UPPER LEVELS, THERE IS STRONG TROUGH BEGINNING TO EXIT THE AREA.
IT SHOWS UP WELL N THE IS AND WATER VAPOR IMAGERY. IT ALSO LINES
UP WITH A 700-500MB THETA E RIDGE THAT IS BEING PUSHED EASTWARD.
ALONG THE THETA E GRADIENT, SHOWERS AND THUNDERSTORMS ARE FIRING
UP. SOME OF THEM ARE INDICATING STRONG THUNDERSTORM
CHARACTERISTICS, INCLUDING SOME POSSIBLE MODERATE TO LARGE HAIL,
GUSTY WIND, AND EVEN SOME WEAK ROTATION. THIS ACTIVITY IS OVER THE
WATER, BUT HAS CAUSED A FEW MARINE STATEMENTS AND WARNINGS TO BE
ISSUED. THE HRRR SHOWS THE ACTIVITY GENERALLY HUGGING THE COAST
FOR THE NEXT FEW HOURS, BEFORE PUSHING OFF TO THE EAST. IT ALSO
SHOWS A FEW SHOWERS POPPING UP OVER THE INTERIOR OF SOUTH FLORIDA.
HAVE KEPT SLIGHT CHANCE POPS IN THE FORECAST TO ACCOUNT FOR THIS
POSSIBILITY. THE HRRR CURRENTLY SHOWS THE MOST OF THE ACTIVITY
WILL DWINDLE FOR A SHORT TIME FOR THE MAINLAND BY AROUND 16Z. BY
ABOUT 21Z, A FEW SHOWERS POP ONCE AGAIN OVER THE MAINLAND. THIS
ACTIVITY IS EXPECTED TO BE COMING TO AN END BY THIS EVENING.
BY TONIGHT, THE 500MB TROUGH BEGINS TO CUTOFF AND SITS OVER THE
EASTERN BAHAMAS. A 500MB RIDGE BRIEFLY BUILDS OVER THE FLORIDA
PENINSULA. BY SATURDAY AFTERNOON, THE SURFACE HIGH SLIDES OFF TO
THE EAST, BECOMING CENTERED NEAR BERMUDA. THE 500MB CUTOFF LOW
BEGINS TO RETROGRADE TOWARDS THE FLORIDA STRAIGHTS. AT THIS TIME,
AN INVERTED SFC TROUGH DEVELOPS OVER THE TURKS AND CAICOS AND
RETROGRADES ALONG WITH THE UPPER LEVEL HIGH, AND SLOWLY DEEPENS AS
WELL. THIS WILL CAUSE AN INCREASE IN THE SFC WIND, ESPECIALLY FOR
THE ATLANTIC WATERS.
BY SUNDAY AFTERNOON, THE UPPER LEVEL RIDGE WEAKENS, AS WELL AS THE
CUTOFF LOW. THERE IS A STRONG TROUGH MOVING INTO THE GULF FROM THE
WEST, ASSOCIATED WITH A DEEPENING TROUGH MOVING ACROSS THE PLAINS
AT THAT TIME. THE SFC HIGH TO THE EAST ALSO WEAKENS. LOOKING AT
THE 700-500MB THETA-E, THE CUTOFF DOES EFFECTIVELY PUSH A RIDGE
BACK OVER SOUTH FLORIDA BY SUNDAY MID DAY. THIS WILL CAUSE AN
INCREASE IN THE RAIN CHANCES ONCE AGAIN.
IT AT THIS POINT THAT MODELS BEGIN TO DIVERGE AND THE FORECAST
BECOMES TO SEE HIGHER UNCERTAINTY. THE GFS TAKES THE STRONG LOW
OVER THE PLANS AND SHOOTS IT TO THE NORTHEAST, OVER THE GREAT
LAKES REGION. THE ASSOCIATED COLD FRONT MAKES IT TO SOUTH CENTRAL
FLORIDA BEFORE STALLING MONDAY NIGHT, AS THEY HAVE BEEN THIS
SEASON SO FAR. IT THEN HAS A STRONG UPPER LEVEL RIDGE BUILD OVER
THE AREA WITH WEAK HIGH PRESSURE WELL TO THE NORTHEAST. IT SHOWS
PERIODS OF MAINLY COASTAL SHOWERS THROUGH THE END OF THE WEEK AND
INTO THE WEEKEND.
THE ECMWF DOES ALSO TAKE THE LOW ALONG THE SAME COURSE AS THE GFS,
BUT HAS THE FRONT SOMEWHAT MORE ENERGETIC, BRINGING RAIN SHOWERS
TO CENTRAL FLORIDA. IT SHOWS SOME WEAK ISENTROPIC LIFT OVER THE
FLORIDA PENINSULA, WHICH COULD GIVE RISE TO SOME SHOWERS ACTIVITY
IN THE LATTER HALF OF THE WEEK. IT THEN HAS ANOTHER SFC LOW
FORMING OVER THE NORTHERN PLAINS IN THE MIDDLE OF THE WEEK. THIS
LOW HAS A COLD FRONT THAT WILL MOVE INTO THE GULF BY WEDNESDAY
AFTERNOON. IT ALSO SHOWS SEVERAL WEAK LOWS COMING OFF THE SOUTH
TEXAS COAST, RIDING ALONG THE FRONTAL BOUNDARY. BY LATE WEDNESDAY
NIGHT, THE ECMWF HAS A LOW DEEPENING ENOUGH TO LIFT THE STALLED
BOUNDARY TO THE NORTH AS A WARM FRONT. IT THEN HAS A STRONGER LOW
DEVELOPING ALONG THE FRONTAL BOUNDARY, WHICH WILL PUSH A STRONGER
COLD FRONT THROUGH SOUTH FLORIDA BY SATURDAY MORNING. THIS WOULD
MEAN HIGHER POPS FOR FRIDAY NIGHT AND COOLER TEMPS BY SATURDAY.
FOR NOW, HAVE ELEVATED POPS TO A CHANCE CATEGORY FOR THIS
POSSIBILITY, ALTHOUGH IT DOES GO AGAINST PERSISTENCE, SO IT DOES
LEAVE ROOM FOR HIGHER UNCERTAINTY WITH THIS SOLUTION.
ALL IN ALL, SOME CONVECTIVE ACTIVITY TODAY BRINGING SHOWERS AND
STORMS, MAINLY TO THE ATLANTIC WATERS, BUT ALSO POSSIBILITY OF
SEEING SOME RAIN IN THE INTERIOR. ONCE THIS QUIETS DOWN, THERE
WILL BE A FEW DAYS OF QUIET WEATHER.
&&
.AVIATION...
THE WINDS WILL BE LIGHT AND VARIABLE EARLY THIS MORNING BEFORE
GOING EASTERLY AFTER 14/15Z TODAY ALONG THE EAST COAST TAF SITES
AT 5 TO 10 KNOTS. KAPF TAF SITE WILL BE LIGHT AND VARIABLE UNTIL
AROUND 18/19Z WHERE THE WIND DIRECTION WILL SHIFT TO A WESTERLY
DIRECTION...AS THE WEST COAST SEA BREEZE DEVELOPS AND PUSHES
INLAND.
THERE COULD BE A SHOWER OR TWO OVER THE EAST COAST TAF SITES THIS
AFTERNOON...BUT THE COVERAGE WILL BE FEW AND FAR BETWEEN.
THEREFORE...THE TAF SITES WILL REMAIN DRY TODAY OVER SOUTH
FLORIDA. THE CEILING AND VIS WILL ALSO REMAIN IN VFR CONDITIONS
TODAY AT ALL OF THE TAF STIES.
&&
.MARINE...
SHOWERS AND THUNDERSTORMS ACROSS THE ATLANTIC WATERS WILL BEGIN TO
QUIET DOWN THIS EVENING. THEN, BY SATURDAY AFTERNOON, THE WIND
WILL INCREASE, ESPECIALLY ACROSS THE ATLANTIC WATERS. THIS WILL
BRING HAZARDOUS MARINE CONDITIONS TO THE ATLANTIC WATERS, WITH
WIND INCREASING TO 20 TO 25 KTS. THIS WILL ALSO CAUSE SEAS TO
BUILD IN THE GULF STREAM TO 5 TO 7 FT BY SATURDAY NIGHT.
CONDITIONS WILL BEING TO IMPROVE ONCE AGAIN SUNDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 82 71 83 75 / 30 10 10 10
FORT LAUDERDALE 82 71 81 74 / 30 10 10 20
MIAMI 84 71 83 75 / 30 10 10 20
NAPLES 83 66 85 69 / 10 10 0 0
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...13/SI
LONG TERM....13/SI
AVIATION...54/BNB
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
325 AM EST FRI DEC 11 2015
.DISCUSSION...
TODAY-TONIGHT...SURFACE HIGH PRESSURE RIDGE VICINITY NORTH
FLORIDA WILL SHIFT INTO THE ATLANTIC AND SLOWLY STRENGTHEN. WEAK
ONSHORE GRADIENT WINDS TODAY WILL PUSH A FEW ATLANTIC SHOWERS
TOWARDS THE TREASURE COAST...BUT AXIS OF SLOW MOVING UPPER LEVEL
TROUGH WILL FINALLY SHIFT OFFSHORE AND ACROSS THE BAHAMAS. THIS
WILL DECREASE THE DEEPER LAYER MOISTURE THAT HAS BEEN BRUSHING OUR
SOUTHERN AREAS. STILL...A SMALL COASTAL SHOWER CHANCE WILL BE
NEEDED ESPECIALLY THIS MORNING FOR THE TREASURE COAST.
THE REST OF THE FORECAST IS JUST STANDARD FARE WITH TEMPERATURES
CONTINUING ABOVE NORMAL AND LITTLE CHANGED FROM YESTERDAY. PARTLY
TO MOSTLY SUNNY SKIES TODAY AND MOSTLY CLEAR TONIGHT. BOUNDARY
LAYER WINDS WILL INCREASE SLIGHTLY TONIGHT WHICH SHOULD CONFINE
PATCHY FOG TO THE NORTH INTERIOR.
SAT-SUN...TRANQUIL WEATHER EXPECTED OUTSIDE OF AN UPTICK IN ONSHORE
FLOW OVER THE WEEKEND. LOCAL PRESSURE GRADIENT WILL TIGHTEN AS A
WEAK SURFACE REFLECTION OVER THE BAHAMAS SHIFTS WEST IN ASSOCIATION
WITH AN UPPER LEVEL LOW. SQUEEZE PLAY BETWEEN THIS FEATURE AND
HIGHER PRESSURE TO OUR NORTH WILL INCREASE ONSHORE WINDS LATE
SATURDAY AND ESPECIALLY SUNDAY...BECOMING BREEZY AT THE COAST.
UPPER LEVEL RIDGING ALOFT WILL EFFECTIVELY CAP VERTICAL MOTION...SO
ANY SHOWER COVERAGE WILL BE DEPENDENT ON LOW LEVEL MOISTURE AND NEAR-
SURFACE CONVERGENCE. STIFF ONSHORE FLOW WILL LIKELY GENERATE LOW END
BRIEF SHOWERS WITH LIMITED IMPACTS AND QPF AMOUNTS GENERALLY BELOW
0.10". GUIDANCE SUGGESTS COVERAGE WILL REMAIN BELOW MENTIONABLE
VALUES (10 PERCENT) THROUGH LATE SATURDAY BEFORE COASTAL SHOWERS
EMERGE ON SUNDAY.
MON-THU..LOW LEVEL FLOW VEERS EARLY IN THE WEEK AS A SURFACE
BOUNDARY MOVES IN FROM THE GULF OF MEXICO. AS HAS BEEN THE CASE FOR
MUCH OF THE "COOL SEASON"...THE PERSISTENT SOUTHEAST RIDGE WILL
DEFLECT MUCH OF THE FRONT`S ENERGY AND SUPPORT OFF TO OUR NORTH AND
WEST. LATEST MODELS SHOW A WEAKENING FRONTAL BOUNDARY REACHING THE
AREA MON. A SQUALL LINE MAY PRECEDE THE FRONT OVER THE GULF OF
MEXICO SUN NIGHT...BUT PRE FRONTAL CONVERGENCE IS FORECAST TO
RAPIDLY WEAKEN AND MID LEVEL TEMPS WILL BE QUITE WARM FOR MID
DECEMBER...SO WILL NOT INCLUDE MENTION OF THUNDER. CONSENSUS POPS
REMAIN LOW WITH THIS FRONT...AROUND 20 PERCENT. THE FRONT IS STILL
FORECAST TO STALL OUT AND LIFT BACK NORTH THROUGH MID WEEK...SO A
PERIOD OF STRUNG OUT LOW POPS MAY OCCUR AGAIN. ALSO...WITH LITTLE
AIR MASS CHANGE INDICATED...WE WILL CONTINUE HAVING WELL ABOVE
NORMAL TEMPERATURES.
&&
.AVIATION...
A FEW PATCHES OF FOG WILL OCCUR UNTIL SHORTLY AFTER SUNRISE THIS
MORNING. A SMALL COASTAL SHOWER CHANCE WILL EXIST MAINLY KFPR-
KSUA THIS MORNING. OTHERWISE VFR TODAY. SOME STRATUS AND A FEW
PATCHES OF FOG ARE POSSIBLE LATE TONIGHT MAINLY INLAND.
&&
.MARINE...
TODAY-TONIGHT...HIGH PRESSURE VICINITY OF NORTH FLORIDA WILL
MIGRATE INTO THE ATLANTIC AND SLOWLY STRENGTHEN. NORTHEAST WINDS
TODAY SHOULD BE AROUND 10 KNOTS THEN VEER TO EAST TONIGHT AND
PICK UP TO 10-15 KNOTS. THE LATEST HRRR MODEL INDICATES SOME
LIGHTNING STRIKES OFFSHORE THE TREASURE COAST TODAY AND WILL
MENTION A SLIGHT CHANCE IN THE SOUTHERN WATERS EARLY THIS
MORNING. THEN BY AFTERNOON THE AXIS OF AN UPPER LEVEL TROUGH WILL
SHIFT EAST OF THE WATERS AND START TO DECREASE DEEP LAYER
MOISTURE.
SAT-SUN...LOCAL PRESSURE GRADIENT TIGHTENS OVER THE WEEKEND AS
WEAK LOW PRESSURE OVER THE BAHAMAS INTERACTS WITH HIGHER PRESSURES
TO OUR NORTH. THE LATEST WAVE GUIDANCE SHOWS SEAS BUILDING TO 5
FEET SATURDAY AND 5-7 FEET SAT NIGHT AND SUNDAY.
MON-WED...A WEAKENING SURFACE FRONT WILL MOVE TOWARD THE AREA EARLY
IN THE WEEK BEFORE MEANDERING OVER THE COASTAL WATERS INTO MID WEEK.
WINDS WILL VEER MORE SOUTHERLY/SOUTHWESTERLY ON MONDAY WHILE
BECOMING LIGHT TO GENTLE. WINDS WILL FURTHER CLOCK AROUND THE
COMPASS ON TUESDAY WHILE REMAINING LIGHT TO GENTLE.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 76 63 78 65 / 0 10 10 10
MCO 79 62 82 64 / 0 10 0 0
MLB 77 67 80 70 / 0 10 10 10
VRB 78 67 80 70 / 10 10 10 10
LEE 79 60 81 64 / 0 10 0 0
SFB 79 62 81 65 / 0 10 10 0
ORL 79 64 81 66 / 0 10 10 0
FPR 78 66 80 70 / 20 10 10 10
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
&&
$$
SHORT TERM...LASCODY
LONG TERM....ULRICH
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
1154 PM CST THU DEC 10 2015
.UPDATE...
ISSUED AT 900 PM CST THU DEC 10 2015
The post-frontal airmass is cooling much quicker than expected,
with CMI already down to 39 and GBG and BMI at 40. There is a band
of cirrus clouds approaching IL from the west, which should help
to limit the additional temp falls later tonight. Have updated the
low temps to put a few mid 30s in the traditional cold spots
along and north of I-74. The other concern is fog potential south
of I-70, especially toward Lawrenceville. Stratus and fog are
already forming in far southern IL, and that trend could progress
up the Wabash River Valley, per HRRR and RAP model output. Have
added a mention of fog S of I-70. There is potential that the fog
could become dense with less than 1/4 mile visibility, so will
watch closely for possible need for a dense fog advisory.
Updated forecast info will be available shortly.
&&
.SHORT TERM...(Tonight)
ISSUED AT 305 PM CST THU DEC 10 2015
Southeasterly winds will become west to northwesterly as a sfc
trough pushes through the area late this afternoon through early
this evening. Gusty winds associated with the tighter gradient
this afternoon will continue some into the early evening hours
after the trough passage. As the trough passes, a weak/brief sfc
ridge will move into the area late tonight. Temps will fall into
the mid 30s in the northwest to the mid 40s in the southeast, with
mostly clear skies.
.LONG TERM...(Friday through Thursday)
ISSUED AT 305 PM CST THU DEC 10 2015
As the sfc ridge moves across the area tomorrow morning, winds
will be lighter and skies should become partly sunny. Once the
ridge passes tomorrow night, southerly winds will return and bring
in much warmer temps for the weekend. With the return to southerly
winds tomorrow afternoon, warm advection pcpn could move into the
east and southeastern sections of the CWA tomorrow afternoon into
tomorrow evening. For now, just looks like light showers.
Then, a stronger system will develop in the southwest US/plains
and begin to influence the weather across the CWA beginning Sat.
Again, warm advection showers will be possible in the west and
northwest starting Sat. Sat night, the sfc frontal system will get
closer to the area and bring moderate rain showers to the area
late Sat night, which will continue into Sunday and Sun night.
This system will be a stronger dynamic system with a good deal of
wind dynamics and shear. So, believe some isolated thunder could
be possible late Sat night and into Sunday. Showers should also
be moving quite quickly with mid level winds at 40-45kts. Models
have trended a little slower with this system so linger high pops
into Sunday night will be continued.
Temps through the weekend will be quite warm with record temps
possible Sat and Sunday. Temps will then begin to decrease some
after the weekend system.
Pcpn could linger some into Monday as the weekend system moves
quickly northeast out of the area. Then relative dry weather is
expected Monday night and Tue as another weak ridge moves through
the area. Southwest flow will continue through the week and this
will allow a short-wave trough and then a long wave trough to push
through the area for Tue night through Thur. For now, will stick
with the ensemble blend of slight chance pops for Tue night
through Thur and wait and see how models play things out after the
weekend. Temps will cool through the week as cloudy skies will
continue through the week. Temps will become even cooler as the
long wave trough rotates through the CWA toward the end of the
week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1154 PM CST THU DEC 10 2015
The 05z surface analysis showed a cold front located just
southeast of Lawrenceville, and progressing away from our area to
the E-SE. In the post-frontal airmass, winds have settled out from
the SW in the 7-11kt range. Clouds over the TAF sites have been
mainly cirrus for the balance of the evening.
As high pressure builds into Illinois from the west, winds will
eventually veer to the south Friday morning, then become southeast
as the next low pressure system approaches from the central
Plains. Low level moisture will increase later Friday afternoon,
increasing the potential for MVFR clouds and visibility for a few
hours. Friday evening, conditions will lower to IFR or LIFR in
stratus, fog and drizzle. Drier conditions above the saturated low
levels should help preclude much in the way of measurable rain
between 12/00z and 12/06z.
&&
.CLIMATE...
ISSUED AT 255 AM CST THU DEC 10 2015
Record highs for the weekend:
Location Today Friday Saturday Sunday
Dec 10 Dec 11 Dec 12 Dec 13
-------- -------- -------- -------- --------
Bloomington 65 (1918) 65 (1949) 65 (1896) 63 (1975)
Champaign 65 (1889) 64 (1949) 62 (1991) 64 (1975)
Charleston 65 (1918) 66 (1931) 67 (1949) 64 (1991)
Decatur 66 (1918) 65 (1949) 65 (1929) 66 (1975)
Effingham 69 (1971) 60 (1979) 67 (1929) 65 (1991)
Lincoln 65 (1918) 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1889) 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1889) 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
UPDATE...Shimon
SHORT TERM...Auten
LONG TERM...Auten
AVIATION...Shimon
CLIMATE...07
AREA FORECAST DISCUSSION
National Weather Service Paducah KY
1140 PM CST THU DEC 10 2015
.SHORT TERM...(Tonight through Sunday Sunday Night)...
Issued at 230 PM CST Thu Dec 10 2015
In the near term, low cloudiness has scoured out after a morning of
fog and low stratus. Temperatures have warmed into the upper 50s to
the lower 60s. We expect temperatures to max out in the next hour
or so and then start their diurnal fall into the 50s this evening.
Surface winds will be gusty this afternoon with sustained 15-20 MPH
speeds and occasional gusts into the 20-25 MPH range. These winds
will slacken off after sunset.
Clouds will increase tonight as low-level isentropic lift will be in
full swing across the region. We expect a mix of low clouds and fog
to develop once again with some light rain and areas of drizzle
expected. The clouds will keep temperatures mild in the south with
lows only dropping into the lower 50s along the KY/TN border with
mid-upper 40s across the far north. Plenty of cloudiness is
expected to continue on Friday with scattered rain showers dotting
the landscape. Southwesterly winds will keep things warm with highs
in the mid to upper 60s. Overnight lows Friday night will not drop
that much...only into the mid-upper 50s.
Saturday looks to be a little drier with the main forcing north and
west of the region. Current guidance suggests record highs in the
lower 70s...though it could be a little warmer if we have more sun.
Another mild night is on tap for Saturday night with lows only
dropping into the upper 50s to around 60.
By Sunday/Sunday night, well advertised storm system will push into
the region from the west. Precipitation will move in from west to
east during the day with the highest chances in the west and lesser
amounts in the east. Instability will be picking up as well so
have continued to mention chance of thunderstorms through the
period. Highest rain chances look to be Sunday night as the actual
front pushes through. Gradient winds will also pick up through this
period as well. Sustained winds of 15-20 MPH with gusts up to 30+
MPH or higher will be possible through early Monday morning.
.LONG TERM...(Monday through Thursday)
Issued at 245 PM CST Thu Dec 10 2015
Upper level pattern will remain progressive aloft during the period.
Large upper level wave will continue to move off to the northeast
early in the period. The upper flow will quickly go back to zonal
late Monday and Tuesday before re-amplyfing by Wednesday as the next
mid-level cyclone moves from the Plains into the western Great
Lakes. This will push another front through the region on
Wednesday/Wednesday night. The moisture return ahead of this
feature is not overly robust, therefore areal coverage of
precipitation is not going to be as widespread as the Sunday/Monday
system.
Upper level teleconection pattern for mid-late next week will
feature a -AO/-NAO/-PNA pattern with the EPO index heading toward
the neutral range. The overall pattern would suggest an short
period of seasonally cold air coming in for late week and into next
weekend as a large upper trough moves through the region. Highs
Monday will likely top out int he 50-55 degree range with upper 50s
to lower 60s on Tuesday ahead of the next weather system.
Temperatures will likely be cooler on Wednesday with higsh in the
upper 40s in the north ot the lower 50s in the south. Much colder
weather arrives by Thursday with highs mainly in the lower-mid 40s.
Overnight lows through the period will generally be in the upper 30s
to the lower 40s, but cool off into the upper 20s to lower 30s by
Thursday morning and Friday morning.
&&
.AVIATION...
Issued at 1139 PM CST THU DEC 10 2015
Moisture continues to pool and be lifted ahead of a stalling cold
front over southeast Missouri and Southwest Illinois late this ev
evening, producing stratocumulus and patchy fog across the area.
Kept a similar, but slower MVFR trend at most locations with
ceilings and viibility. Maintained this trend through most of the
24 hour forecast period.
&&
.PAH Watches/Warnings/Advisories...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AVIATION...Smith
Area Forecast Discussion
National Weather Service Louisville KY
1227 AM EST FRI DEC 11 2015
...Updated Aviation Discussion...
...Forecast Update...
Updated at 920 PM EST Thu Dec 10 2015
Minor adjustments made to the overnight forecast, but for the most
part it`s on track. Latest IR imagery and GOES-R probability tools
show lower ceilings associated with the warm, moist southerly flow
beginning to take shape across western TN, southwest KY. This low-
level moisture plume is on track to surge northeastward into central
Kentucky overnight.
Latest soundings and RAP forecasts show a steady southwest wind just
off the deck, which may keep this low-level moisture more stratus
than fog. 11.00z OHX sounding shows moisture rooted at around 900
mb, and RAP RH fields at this layer suggest this moisture overtaking
the area between 06-09z. Will continue mention of fog, some dense,
in the forecast but it may end up being a low stratus deck that
lasts well into Friday.
Otherwise, mild night is on tap with lows expected to not stray too
far from current readings (upper 40s to mid 50s).
.SHORT TERM (Now through Friday Night)...
Issued at 325 PM EST Thu Dec 10 2015
Expect a few peeks at the sun through the remainder of the
afternoon, although variable cloudiness should hang over the region.
Temps should mostly remain in the 50s for the remainder of the
afternoon.
Low level clouds will again increase overnight as low level moisture
is trapped under a shallow inversion and an isentropic lift
component picks up. Will go with low chances for measurable
precipitation, and mention of drizzle given the shallow moisture.
Also concerned about low stratus build down into some impactful fog
so will mention patchy/areas for now. Not sure how dense it will get
given the steady south low level winds and an uptick in near surface
winds, however this did not stop dense fog from setting in last
night. Will mention in the HWO and continue to evaluate for possible
headlines.
Expect a small diurnal trend given the steady south winds and cloud
cover. Lows will only be in the upper 40s and lower 50s.
The devloping warm front will begin to lift north over the area
Friday and Friday night as we switch to deeper SW flow through the
column in response to an amplifying pattern. This will shift main
showery precip chances to mainly our northern CWA. We`ll also see
milder temps across the south in the mid and upper 60s. Expect temps
to reach the low 60s north on the warm advection component.
Another mild night Friday night as we stay in the warm sector. We`ll
keep small chances for measurable showers mainly across the north.
Lows only expected to drop into the upper 50s to around 60 given the
steady warm advection.
.LONG TERM (Saturday through Thursday)...
Issued at 325 PM EST Thu Dec 10 2015
Saturday - Sunday...
The pattern continues to amplify through the weekend as a potent
upper disturbance digs a trough into the southern Plains and SE
CONUS ridge tries to hold. This puts the Ohio River Valley in deep
SW flow, although the dry warm sector should keep things mostly dry,
very mild, and windy.
Expect a few isolated showers to quickly leave southern IN by midday
Saturday with the southerly winds increasing as the pressure
gradient tightens between the southern Plains low and surface high
to our east. This will help temps rise near and around the 70 degree
mark under more peeks at the sun and increasing heights/thicknesses.
Saturday record high temperatures are in real jeopardy as they are
at 68 for all 4 major climate sites and we are forecasting a tie or
break at each. Most notably, the record high of 68 at LEX dates all
the way back to 1873!
A mild Saturday night will also put record warm minimums in jeopardy
as the strong warm advective component increases. Only expecting
lows in the mid 50s to around 60.
As we move into Sunday, pressure gradient tightens even more, to the
point where a Wind Advisory will be a good bet. Low level thermal
profiles look to support mixing up into a layer where gusts in the
30-40 mph range aren`t out of the question. This strong southerly
flow combined with some sun should allow for even warmer temps into
the low 70s. Some guidance even suggests mid 70s which isn`t out of
the question. The one limiting factor could be cloud cover.
Sunday Night - Monday...
Strong upper anomaly ejects out of the southern Plains into the
Great Lakes Sunday evening into Monday, taking on a negative tilt as
it does. This will bring a deep moisture plume over our region as a
low level jet increases in response to the upper jet arrival. We`ll
keep the strong gradient winds in place through the evening ahead of
the front, meanwhile widespread and a strongly forced line of
showers will move through. Still not overly impressed with
instability potential, but given the warm day ahead and continued
warm advection, enough surface based instability may develop for
some stronger gusts to mix down in showers/storms that evening.
Additionaly, some heavy rainfall is possible, although the overall
system is progressive enough that no major concerns are warranted.
Overall QPF should range around 1 inch with some spots seeing
locally higher amounts.
Cold front pushes through later Sunday night into Monday with
lingering showers clearing from SW to NE through the day. Expect
cooler highs back in the 50s (not a statement you see too often in
mid december!).
Monday Night - Thursday...
Progressive upper ridge and surface high pressure keep us dry and
cooler through Tuesday night, although not a substantial airmass
change. Look for highs mostly in the 50s and lows in the 39-43 range.
Chances for rain return Wednesday through Thursday as another front
progresses through our deep SW flow pattern. Confidence is a little
sketchy on timing so will mention low chances for now. A secondary
cool down will occur behind this boundary, with cold air trying to
catch up to any lingering moisture Wednesday night into Thursday.
Will hold off on any frozen precip mention as this scenario rarely
works out.
&&
.AVIATION (06Z TAF Update)...
Updated at 1225 AM EST Fri Dec 11 2015
Poor flying conditions expected for most of this period. Lower cigs
are coming and will persist as low-level lift sets up combined with
southerly winds bringing moisture into the region. Some light
drizzle/rains may fall from these low clouds, but the main hazard
will be the lower cigs. Expect low-end MVFR conditions to set up
over the next 2-3 hours and then drop down to IFR by daybreak. Time
height sections indicate their could be a brief rise in cigs at KSDF
and KLEX between 15-21Z...but then cigs should fall again with
sunset.
&&
.LMK Watches/Warnings/Advisories...
KY...NONE.
IN...NONE.
&&
$$
Update.........ZT
Short Term.....BJS
Long Term......BJS
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
345 AM CST FRI DEC 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST FRI DEC 11 2015
CHALLENGES THROUGH TONIGHT INCLUDE CLOUD TRENDS/TEMPERATURES...AND
DRIZZLE POTENTIAL THIS EVENING INTO THE OVERNIGHT. WILL FOLLOW A
BLEND BETWEEN THE 11.00Z NAM/ECMWF/GEM THROUGH 12Z SATURDAY WITH
THE MUCH DRIER GFS BEING AN OUTLIER IN THE SHORT-TERM.
FOR TODAY...A SURFACE TROUGH WILL DEVELOP IN THE LEE OF THE
SOUTHERN ROCKIES AND INTO THE CENTRAL PLAINS IN RESPONSE TO A
DEEPENING TROUGH ACROSS THE WESTERN CONUS. RAP RELATIVE HUMIDITY
SUGGESTS AREAS ALONG AND NORTH OF THE I-90 CORRIDOR WILL REMAIN
MOSTLY CLOUDY FOR A GOOD PORTION OF THE DAY WITH A MIX OF SUN AND
HIGHER CLOUDS FURTHER SOUTH. THESE CLOUDS...COMBINED WITH A COOLER
LOW-LEVEL THERMAL PROFILE IN THE WAKE OF YESTERDAY/S STORM SYSTEM
WILL RESULT IN TEMPERATURES 5 TO 10 DEGREES BELOW YESTERDAY/S
READINGS. AFTERNOON HIGHS WILL RANGE FROM AROUND 40 DEGREES ACROSS
NORTH-CENTRAL WI TO NEAR 50 DEGREES ACROSS PORTIONS OF NORTHEAST
IA INTO ADJACENT AREAS OF SOUTHWEST WI.
SURFACE TO 850 HPA LAYER SLOWLY SATURATES THIS EVENING/OVERNIGHT
AND WITH MODEST LIFT ALONG THE 285 TO 290 K ISENTROPIC SURFACE...
EXPECT PATCHY TO AREAS OF DRIZZLE MAINLY ALONG AND NORTHEAST OF
THE MS RIVER VALLEY. SURFACE TEMPERATURES WILL REMAIN ABOVE
FREEZING WITH LOWS MAINLY IN THE MID TO UPPER 30S...SO IMPACT WILL
BE NEGLIGIBLE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 AM CST FRI DEC 11 2015
WILL KEEP 20 POPS FOR ANY LINGERING DRIZZLE ON SATURDAY...BUT
MOST OF THE DAY SHOULD BE DRY AS PRIMARY ISENTROPIC LIFT MOVES
NORTH OF THE FORECAST AREA. SKIES WILL BE MOSTLY CLOUDY WITH
TEMPERATURES SIMILAR TO TODAY...PERHAPS A DEGREE OR TWO WARMER.
PRIMARY FOCUS WILL BE SATURDAY NIGHT THROUGH MONDAY AS AN
IMPRESSIVE STORM SYSTEM MOVES ACROSS THE UPPER MIDWEST. A STRONG
WARM FRONT WILL SURGE NORTHWARD SATURDAY NIGHT...USHERING IN VERY
WARM AND MOIST CONDITIONS FOR MID-DECEMBER. PWATS LOOK TO INCREASE
ABOVE ONE INCH SATURDAY NIGHT INTO SUNDAY...WHICH IS 3 TO 4
STANDARD DEVIATIONS ABOVE CLIMATOLOGY ACCORDING TO THE 11.00Z
NAEFS. SURFACE FRONT STALLS OUT ON SUNDAY...BISECTING THE FORECAST
AREA FROM SOUTHWEST TO NORTHEAST AND PROVIDES A FOCUS FOR
SIGNIFICANT LIFT. AS A RESULT...EXPECT PERIODS OF MODERATE TO
HEAVY RAIN SATURDAY NIGHT THROUGH SUNDAY AND SUNDAY NIGHT.
ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE MAINLY ACROSS NORTHEAST
IA INTO SOUTHWEST MN AS 0 TO 6 KM MUCAPE RISES TO BETWEEN 100 AND
300 J/KG. TOTAL RAINFALL WILL RANGE FROM 1.5 TO 2.25 INCHES. SEE
HYDROLOGY SECTION BELOW FOR POSSIBLE IMPACTS ON AREA RIVERS AND
STREAMS.
DESPITE THE CALENDAR...PRECIP WILL FALL AS ALL RAIN THROUGH
SUNDAY NIGHT AS 925 HPA TEMPERATURES CLIMB TO BETWEEN +11 AND +13
CELSIUS BY 18Z SUNDAY. EVEN WITH CLOUD COVER AND RAIN...THIS
SHOULD RESULT IN SUNDAY AFTERNOON HIGHS FROM THE MID 40S ACROSS
THE NORTHWEST TO NEAR 60 DEGREES IN THE SOUTHEAST.
PRIMARY DISAGREEMENT BETWEEN THE 11.00Z GLOBAL MODEL SUITE AT
THIS TIME IS THE SPEED IN WHICH THIS SYSTEM MOVES OUT OF THE
REGION ON MONDAY. THE GFS/NAM/GEM PLACE THE SURFACE LOW OVER LAKE
SUPERIOR BY 18Z MONDAY...WHEREAS THE ECMWF IS MUCH SLOWER WITH ITS
LOW OVER SOUTHEAST MN. THE FORMER CONSENSUS SOLUTION WOULD RESULT
IN A MUCH COLDER AIR MASS ALOFT MOVING INTO THE REGION MORE
QUICKLY...THUS INCREASING THE CHANCE FOR LINGERING PRECIP TO TURN
INTO A WINTRY MIX. AT THIS TIME...THINK VAST MAJORITY OF PRECIP
WILL OUTRUN THE COLDER AIR WITH MINIMAL IMPACT TO THE REGION.
HOWEVER...COULD STILL SEE SOME NON-ACCUMULATING SNOW FLAKES ON
MONDAY WITH HIGHS FROM THE MID 30S TO MID 40S.
ANOTHER DEEP TROUGH MOVES INTO THE NATION/S MID-SECTION BY LATE
TUESDAY/WEDNESDAY...BUT GFS/ECMWF BOTH SHOW THE MAJORITY OF
PRECIP MOVING ACROSS THE DAKOTAS INTO NORTHERN MN...KEEPING THE
FORECAST AREA WITHIN THE SYSTEM/S DRY SLOT. FOR NOW...WILL
MAINTAIN THE SUPERBLEND CHANCE POPS GIVEN THE INHERENT
UNCERTAINTIES WITH A SYSTEM ON DAYS 5-7. OF GREATER CERTAINTY FOR
NEXT WEEK...TEMPERATURES WILL FALL EACH DAY...NEARING SOMETHING
CLOSER TO MID-DECEMBER NORMALS. HIGHS WEDNESDAY/THURSDAY LOOK TO
TOP OUT IN THE UPPER 20S TO MID 30S...A SHOCK TO THE SYSTEM GIVEN
THE ABNORMAL WARMTH OF THE PAST FEW WEEKS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1100 PM CST THU DEC 10 2015
CLOUD FORECAST PRESENTING SOME CHALLENGES. MOSTLY VFR CLOUD DECK
RETURNED EARLY THIS EVENING...BUT IFR/MVFR CLOUDS SIT JUST A BIT
FARTHER NORTH...AND MESO MODELS RH FIELDS AND BUFKIT SOUNDINGS
SUGGEST THIS COULD/WILL DROP TO THE I-90 CORRIDOR...THUS IMPACTING
KRST/KLSE. ITS NOT A DONE DEAL BY ANY MEANS...BUT LATEST SATELLITE
TRENDS AND MODEL RUNS SUGGEST ITS BECOMING MORE LIKELY. WILL OPT TO
ADD SEVERAL HOURS OF IFR/MVFR CIGS...WITH EXPECTATIONS THAT THE
CLOUDS WILL LIFT BACK NORTH BEFORE 18Z. SOME VSBY REDUCTION ALSO
LOOK LIKELY...WITH PROBABILITIES FAVORING MVFR...LOWER FARTHER
NORTH.
INCREASING LOW LEVEL MOISTURE/THERMODYNAMICS SHOULD USHER IN MORE
LOW CIGS FRI EVENING. SEE SOME POTENTIAL FOR -DZ TOO...WITH IMPACTS
TO VSBYS IF IT WOULD DEVELOP. WILL ADD MVFR CIGS FOR THE MOMENT...
BUT LEAVE PCPN FREE.
&&
.HYDROLOGY...
ISSUED AT 345 AM CST FRI DEC 11 2015
TOTAL RAINFALL SATURDAY NIGHT THROUGH SUNDAY WILL RANGE FROM 1.5
TO 2.25 INCHES. RIVERS ACROSS THE REGION ARE RUNNING IN THE 90TH
PERCENTILE RANGE FOR THIS TIME OF YEAR. ALTHOUGH NO FLOODING IS
EXPECTED AT THIS TIME...PLAN ON SIGNIFICANT WITHIN BANK RISES.
THOSE WITH INTERESTS ALONG AREA RIVERWAYS ARE ENCOURAGED TO STAY
TUNED TO LATEST FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM...ROGERS
AVIATION.....RIECK
HYDROLOGY...DAS/ROGERS
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
845 AM MST FRI DEC 11 2015
&&
.SYNOPSIS...
A STRONG PACIFIC LOW PRESSURE SYSTEM AND COLD FRONT WILL MOVE
THROUGH THE REGION TODAY...GENERATING COOLER AND WINDY CONDITIONS. A
CHANCE OF SHOWERS ARE ALSO FORECAST MAINLY OVER PORTIONS OF SOUTH
CENTRAL ARIZONA LATE THIS AFTERNOON THROUGH EARLY SATURDAY. CLEAR AND
COLDER WEATHER IS EXPECTED SUNDAY...WITH ANOTHER COLD FRONT FORECAST
TO MOVE INTO THE REGION ON MONDAY. A MUCH COLDER AIRMASS IS FORECAST
TO SETTLE OVER THE REGION TUESDAY AND WEDNESDAY...POSSIBLY GENERATING
SOME OF THE COLDEST LOW TEMPERATURES SO FAR THIS SEASON.
&&
.DISCUSSION... A SIGNIFICANTLY MILDER MORNING THIS MORNING WHEN
COMPARED TO THE LAST SEVERAL DAYS ACROSS THE REGION. THE COMBINATION
OF INCREASED CLOUDINESS AND WINDS HAS KEPT LOWS UP IN THE 50S...AND
EVEN SOME LOW 60S ACROSS SE CA. THE SFC COLD FRONT THAT IS EXPECTED
TO BRING MUCH COOLER WEATHER...AND A CHANCE FOR PRECIP ACROSS THE
REGION IS JUST NOW MOVING INTO SE CA AND THE LOWER COLORADO RIVER
VALLEY. ALTHOUGH THE LATEST RADAR IMAGERY IS NOW SHOWING A FEW
SHOWERS DEVELOPING ACROSS NORTHERN AZ AHEAD OF THE FRONT...THE
LATEST HRRR HIGH-RES MODEL RUN IS STILL NOT SHOWING ANY PRECIP
DEVELOPING ACROSS OUR CWA UNTIL LATE THIS AFTERNOON/EARLY
EVENING...ONCE THE SFC COLD FRONT PASSES...UNDER THE AREA OF BEST
DIFFLUENCE/HEIGHT FALLS AHEAD OF THE MAIN UPPER TROF. STRONG
WESTERLY WINDS THAT HAD BEEN BLOWING IN THE IMPERIAL/EL CENTRO AREA
EARLIER THIS MORNING HAVE DIMINISHED...BUT MORE GUSTY WINDS ARE
STILL EXPECTED FROM LATER THIS MORNING INTO THE AFTERNOON ACROSS SE
CA AND THE LOWER COLORADO RIVER VALLEY...BEHIND THE SFC COLD FRONT.
AS FAR AS THE FORECAST FOR THE REMAINDER OF THIS MORNING/EARLY THIS
AFTERNOON IS CONCERNED...OTHER THAN SOME MINOR ADJUSTMENTS TO THE
HOURLY TEMPERATURE GRIDS...INHERITED FORECASTS ARE HOLDING UP WELL.
&&
.PREVIOUS DISCUSSION...
TODAY THROUGH SATURDAY...
A STRONG PACIFIC TROF AND COLD FRONT CONTINUED TO APPROACH AZ THIS
MORNING. AROUND MIDNIGHT THE FRONT WAS LOCATED FROM LAS VEGAS WEST
TO SANTA BARBARA AND IS FORECAST TO PUSH THROUGH THE COLORADO RIVER
VALLEY AROUND NOON THEN INTO PHOENIX AT 3 PM FRI. VERY NOTICEABLE
AND ABRUPT COOLING WILL TAKE PLACE WITH THE FRONTAL PASSAGE IN
SOUTHEAST CA/COLORADO RIVER VALLEY...ALONG WITH STRONG WINDS PEAKING
TO 40 MPH IN SPOTS. A WIND ADVISORY REMAINS POSTED FOR A LARGE PART
OF SOUTHEAST CA AND THE COLORADO RIVER VALLEY THROUGH 6 PM FRIDAY
EVENING.
ADDITIONALLY...THURSDAY EVENING SATELLITE IMAGERY AND WEATHER
BALLOON SOUNDINGS ALONG THE WEST COAST PAINTED A PICTURE OF A
RELATIVELY DRY SYSTEM. HOWEVER DESPITE THESE INITIAL LOOKS...THIS
SYSTEM WILL MOVE INTO SOUTHWEST AND SOUTH CENTRAL AZ VERY
POWERFULLY...DYNAMICALLY...OR SUCCINCTLY PUT...GENERATING A
CATASTROPHE ALOFT. A STRONG VERTICAL MOTION FIELD WILL DEVELOP LATE
THIS AFTERNOON AND EVENING MAINLY OVER SOUTH CENTRAL AZ...AND WILL
WRING OUT THE AIRMASS PROVIDING A CHANCE OF SHOWERS. THE BEST CHANCE
OF SHOWERS THIS EVENING AND OVERNIGHT WILL BE OVER THE MOUNTAINS
EAST OF PHOENIX IN SOUTHERN GILA COUNTY...INCLUDING EFFICIENT
UPSLOPE PRECIP. THE SNOW LEVEL WILL FALL TO 5500 FEET BY MIDNIGHT IN
SOUTHERN GILA COUNTY...THEN NEAR 5000 FEET SATURDAY MORNING WHEN
CONDITIONS BECOME A LITTLE DRIER. ANY LIGHT ACCUMULATIONS WILL BE
ABOVE THE POPULATION CENTERS IN SOUTHERN GILA COUNTY. UNFORTUNATELY
FOR SOUTHEAST CA AND THE COLORADO RIVER VALLEY...RAIN SHADOW EFFECTS
FROM THE COASTAL MOUNTAINS WILL PRECLUDE ANY PRECIP.
THE PACIFIC LOW PRESSURE SYSTEM WILL QUICKLY MOVE INTO NEW MEXICO BY
EARLY SATURDAY AFTERNOON...HOWEVER AFTERNOON INSTABILITY CLOUDS AND
A SLIGHT CHANCE OF SHOWERS ARE A POSSIBILITY DRIFTING OFF THE
MOUNTAINS INTO THE NORTHERN PORTIONS OF THE PHOENIX AREA...AND INTO
MOST OF SOUTHERN GILA COUNTY.
SUNDAY...
CLEARING SKIES AND CONTINUED COOL WEATHER IS EXPECTED SUNDAY.
MONDAY...
ANOTHER COLD PACIFIC TROF IS FORECAST TO DEEPEN OVER THE REGION
MONDAY RESULTING IN A SLIGHT CHANCE OF SHOWERS FROM PHOENIX
EASTWARD.
TUESDAY THROUGH THURSDAY...
A VERY COLD AND DRY AIRMASS WILL SETTLE OVER THE REGION AND PROVIDE
SOME OF THE COLDEST LOW TEMPERATURES SO FAR THIS SEASON. FREEZE
WARNINGS ARE A POSSIBILITY IN MANY DESERTS LOCATIONS OF SOUTHWEST
AND SOUTH CENTRAL AZ.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA...AND KSDL...
A COLD FRONT WILL MOVE THROUGH LATER TODAY WITH INCREASING SOUTHWESTERLY
SURFACE WINDS STARTING LATE THIS MORNING AND STRENGTHENING THROUGH
EARLY AFTERNOON. NOT MUCH MOISTURE WITH THIS SYSTEM WITH CEILINGS
MOSTLY REMAINING ABOVE FL150 THROUGH 00Z BUT WITH SOME SCATTERED
CUMULUS FL050-070 AFTER 16Z. GOOD POTENTIAL FOR LOWER CIGS AROUND
6-7K FEET TONIGHT WITH A FEW ISOLATED SHOWERS POSSIBLE...BUT MAINLY
STAYING NORTH AND EAST OF THE PHOENIX TERMINALS.
SOUTHEAST CALIFORNIA/SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
WEST TO SOUTHWESTERLY WINDS WILL CONTINUE THROUGH TODAY WITH THE
STRONGEST WIND GUSTS UP TO 40 MPH OCCURRING THIS AFTERNOON. NOT MUCH
MOISTURE WITH THIS SYSTEM WITH CEILINGS MOSTLY REMAINING ABOVE 15K
FEET. WINDS WILL GRADUALLY SUBSIDE STARTING LATE THIS EVENING INTO
THE OVERNIGHT.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SUNDAY THROUGH THURSDAY...
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE PERIOD AS A
COUPLE OF LOW PRESSURE TROUGHS AFFECT THE REGION. A CHANCE OF
SHOWERS TO MAINLY HIGHER TERRAIN LOCATIONS NORTH AND EAST OF PHOENIX
IS POSSIBLE ON MONDAY WITH EVERY OTHER DAY STAYING PRECIP FREE. THE
COOL TEMPERATURES WILL ALLOW FOR HIGHER HUMIDITIES WITH MINIMUM
AFTERNOON VALUES ONLY FALLING INTO A 20 TO 40 PERCENT RANGE. GUSTY
NORTHWESTERLY WINDS ARE LIKELY ON MONDAY AND TUESDAY...ESPECIALLY
AFFECTING THE LOWER COLORADO RIVER VALLEY.
&&
.SPOTTER INFORMATION STATEMENT...
SPOTTERS ARE ENCOURAGED TO REPORT BASED ON STANDARD OPERATING
PROCEDURES.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...WIND ADVISORY FROM 9 AM THIS MORNING TO 6 PM PST THIS EVENING
FOR CAZ032-033.
WIND ADVISORY UNTIL 6 PM PST THIS EVENING FOR CAZ030.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/VASQUEZ
AVIATION...KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
548 AM CST FRI DEC 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 416 AM CST FRI DEC 11 2015
TODAY WILL SERVE AS A DAY OF TRANSITION FROM THE WIDESPREAD VERY
MILD CONDITIONS OF LATE...TO A COOLER AND MORE UNSETTLED REGIME
STARTING THIS WEEKEND. NARROW RIDGE OF HIGH PRESSURE FROM SOUTHWEST
MINNESOTA TO NORTHWEST IOWA WILL CONTINUE TO DRIFT EASTWARD...AS
BROAD LOW PRESSURE ACROSS THE WESTERN PLAINS SPREADS EASTWARD.
WAVE AT THE MID AND UPPER LEVELS SHEARING/LIFTING NORTHEASTWARD...SO
SHOULD SEE A LIMITED PUSH TO LOWER LEVEL BAROCLINICITY AS INVERTED
TROUGH SLIPS ACROSS THE CWA...LIKELY TO REACH AND STALL OUT WELL
SOUTHEAST ACROSS IOWA BY EARLY SATURDAY. ANY PRECIPITATION THREAT
WITH THE INITIAL WAVE TODAY WOULD SEEM TO BE QUITE MINIMAL...AND
FOCUSED MAINLY NORTH OF THE AREA.
MODELS NOT HANDLING THE LOWER CLOUDS PARTICULARLY WELL WHICH EXTEND
ALONG HIGHWAY 14. AS LOW LEVEL FLOW CONTINUES TO FEATURE AN EAST TO
NORTHEAST COMPONENT...HAVE DOUBTS WHETHER SOME AREAS MAY SHAKE
CLOUDS AT ALL...WHICH SHOULD GET A REFRESHED SOUTHWARD PUSH BEHIND
THE INVERTED TROUGH. TEMPS MAY STRUGGLE SOMEWHAT THROUGH THE FAR
NORTH TO REACH VERY FAR INTO THE 40S...WHILE PERIODS OF THINNER
HIGHER CLOUDINESS SOUTH ALLOW FOR AT LEAST A RETURN TO THE
LOWER 50S.
WHILE WILL SEE AN INCREASE IN LOWER LEVEL MOISTURE THROUGH FRIDAY
NIGHT...DEPTH WILL REMAIN AN ISSUE IN TERMS OF PRECIPITATION THREAT.
WITH SLIGHT RIDGING ALOFT BETWEEN THE WAVE FROM TODAY TO THE NORTH
AND THE MAIN TROUGH DIGGING THROUGH THE SOUTHERN ROCKIES...DO NOT
GET ANY COHERENT DEEPER LIFT GOING AS WELL. EVEN SHALLOW LIFT IN THE
MOIST LAYER IS PROBLEMATIC FOR THE MOST PART...WITH POTENTIAL
EXCEPTION OF FAR EASTERN AREAS WITH SOME ELEVATED WARM ADVECTION
TONIGHT. AT THIS TIME...A FAIRLY LOW PROBABILITY OF HAVING ELEMENTS
COME TOGETHER...THUS HAVE NOT MADE MENTION OF ANY NON MEASURABLE
TYPE OF PRECIPITATION...BUT WILL HAVE TO MONITOR FOR ANY BETTER
DRIZZLE OR FREEZING DRIZZLE SIGNALS IN THE LATER FRIDAY NIGHT/EARLY
SATURDAY OVERNIGHT PERIOD. WITH MORE WIDESPREAD LOWER CLOUDINESS
OVERNIGHT...LOWS SHOULD REMAIN UPPER 20S TO LOWER 30S.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 416 AM CST FRI DEC 11 2015
ON SATURDAY...STRONG SOUTHWEST FLOW ALOFT IS IN PLACE AS OUR LARGE
UPPER LOW MOVES SLOWLY ACROSS THE FOUR CORNERS AREA. NOT EXPECTING A
LOT IN THE WAY OF PRECIPITATION DURING THE DAY PERIOD...AS WE HAVE A
LARGE DRY LAYER TO OVERCOME IN THE 700-500MB LAYER. THE ONLY
EXCEPTION TO THIS IS IN OUR EXTREME WESTERN ZONES NEAR CHAMBERLAIN
SD WHERE DEEPER SATURATION EXISTS. BECAUSE OF THIS...OUR CENTRAL SD
AREA WILL LIKELY RECEIVE SNOWFALL...AT LEAST BY AFTERNOON...WITH
TEMPERATURES ALOFT AND AT THE SURFACE COOL ENOUGH THAT THERE COULD
BE A LITTLE ACCUMULATION. BUT ELSEWHERE...ONLY SLIGHT CHANCE
TO LOWER END CHANCE POPS ARE WARRANTED DUE TO THE AFOREMENTIONED DRY
LAYER...WITH DRIZZLE POSSIBLE A THREAT. DID NOT INCLUDE DRIZZLE
YET AS THAT IS JUST ONE MORE ELEMENT TO CONFUSE THINGS IN AN
ALREADY COMPLICATED MIXED PRECIP FORECAST REGIME. DESPITE THE DRY
MID LEVEL DRY LAYER...WHAT WE DO HAVE IS PRETTY STRONG ISENTROPIC
LIFT BEGINNING AT 290K AND IN A PRETTY DEEP LAYER. THE PRECIPITATION
TYPE LOOKS TO BE PREDOMINANTLY LIQUID IN NORTHWEST IA...WITH A
POSSIBLE EXTREMELY LIGHT WINTRY MIX ALONG AN AXIS FROM LAKE
ANDES/YANKTON SD...NORTHEASTWARD TO BROOKINGS AND MARSHALL...WHICH
WOULD INCLUDE SIOUX FALLS. BUT WITH SURFACE TEMPERATURES JUST ABOVE
FREEZING...IT IS QUITE DOUBTFUL THAT ANY MIXED PRECIP WILL ACTUALLY
STICK BECAUSE RATES WILL BE TOO LIGHT TO OVERCOME THE RELATIVELY
MILD TEMPERATURES AND THUS NOT ACCUMULATE. FOR SATURDAYS HIGHS...
MODEL SOUNDINGS SUGGEST A VERY ISOTHERMAL DAY FROM 925MB...SO RELIED
HEAVILY ON TEMPERATURES FROM JUST ABOVE THE SURFACE...WITH HIGHS
RANGING FROM THE MID 30S IN OUR WESTERN AND NORTHERN ZONES ALONG
HIGHWAY 14...PROGRESSIVELY WARMING TO THE LOWER 40S AROUND SIOUX
CITY AND STORM LAKE IA.
ON SATURDAY NIGHT...THE VARIOUS MODELS ARE STILL IN GOOD AGREEMENT
IN MOVING THE UPPER LOW ABOUT DUE EASTWARD TOWARD THE TEXAS AND
OKLAHOMA PANHANDLES. THE NAM AND GFS SOUNDINGS BEGIN TO RAPIDLY
SATURATE SATURDAY EVENING WHICH SHOULD BEGIN TO USHER IN THE PRECIP
IN EARNEST FOR THE ENTIRE FORECAST AREA. THAT SAID...QPF AMOUNTS
STILL LOOK FAIRLY LIGHT WITH A LACK OF STRONG FOCUS MECHANISM OTHER
THEN ISENTROPIC LIFT. THE FRONTOGENESIS IS WEAK...AND THE UPPER QG
FORCING IS VERY BROAD...ACTUALLY EXTENDING ALL THE WAY FROM TEXAS TO
CANADA. THE ONE EXCEPTION TO THE LIGHT PRECIP AMOUNTS IS ACROSS
NORTHWEST IA AND THE EASTERN SECTIONS OF SOUTHWEST MN...WHERE
ELEVATED MU CAPES ARE AROUND 250-300 J/KG PROVIDING A BIT OF
INSTABILITY. SO THOSE AREAS COULD RECEIVE A QUARTER TO A THIRD OF AN
INCH OF RAINFALL. ELSEWHERE...TEMPERATURES BOTH AT THE SURFACE AND
ALOFT ARE COLD ENOUGH THAT DECENT SNOW IS A THREAT IN OUR FAR
WESTERN ZONES...AGAIN TOWARD CENTRAL SD...WITH 2 TO 3 INCHES LIKELY
AROUND CHAMBERLAIN AND WEST OF HURON. IN BETWEEN OUR WEST AND
NORTHWEST IOWA ZONES...WE ARE STILL DEALING WITH A WINTRY MIX OF
PRECIPITATION ALONG THE SAME AXIS MENTIONED IN THE ABOVE PARAGRAPH.
MOST CONCERNING IS THE HEART OF SOUTHWEST MN WHERE ICE ACCUMULATIONS
COULD RANGE FROM 0.05 TO A 0.10 OF AN INCH SOMEWHAT DUE TO HIGHER
ELEVATIONS. MUCH LIGHTER ICE AMOUNTS LOOK TO BE IN THE OFFERING
ELSEWHERE. CONCERNING LOWS...MANY OF THE CONSENSUS GUIDANCE VALUES
LOOKED TOO COOL GIVEN THE INCREASING NORTHERLY WINDS AND VERY
ABUNDANT CLOUD COVER...COUPLED WITH A LACK OF COLD AIR ADVECTION.
THEREFORE BLENDED WARMER ECMWF AND GEM GLOBAL VALUES INTO THE MIX
WHICH KEEPS LOWS ABOVE FREEZING ALONG AND EAST OF HIGHWAY 60 IN OUR
SOUTHEAST ZONES.
THE MODELS BEGIN TO SEVERELY DIVERGE SUNDAY AND SUNDAY NIGHT. THE
GEM GLOBAL AND GFS ARE IN ONE CAMP...IN LIFTING THE UPPER LOW INTO
NORTHERN ILLINOIS AND WISCONSIN BY 12Z MONDAY. THE ECMWF SLOWS THE
LOW PROGRESSION DOWN AND IS ONLY IN SOUTHERN IOWA AND NORTHERN MO BY
12Z MONDAY. FOR NOW...WENT WITH THE CONSENSUS SOLUTIONS OF THE
GEM AND GFS. HOWEVER IT IS DIFFICULT TO TOTALLY DISCOUNT THE ECMWF
AS IT WAS FIRST TO SHOW THE MAJOR SNOW STORM IN MID NOVEMBER. JET
DYNAMICS ARE NOT WELL PLACED WITH THIS EVENT WITH ANY MODEL TO AID
IN REAL STRONG ASCENT...AND IT DOES NOT LOOK AS UNSTABLE AS THE
NOVEMBER EVENT. BUT IF THE ECMWF WOULD VERIFY WITH ITS SLOWER
SOLUTION...THAT WOULD ALLOW SOME COOLER AIR ALOFT AND AT THE SURFACE
TO FILTER DOWN SUNDAY AND SUNDAY NIGHT AND GIVE A DECENT SWATH OF
SNOW BY LATE SUNDAY NIGHT AND MONDAY FOR AREAS EAST OF THE JAMES
RIVER VALLEY. SO IT NEEDS WATCHED. DID USE SOME OF THE ECMWF HOWEVER
IN RADICALLY INCREASING POPS SUNDAY AND SUNDAY NIGHT ALONG AND EAST
OF HIGHWAY 60 OVER SUPERBLEND...ALTHOUGH IRONICALLY SO FAR THE
SUPERBLEND QPF AMOUNTS DID NOT LOOK TOO BAD. BUT AGAIN IF THE ECMWF
VERIFIES IN FUTURE MODEL RUNS...REAL HIGH POPS WILL BE WARRANTED
EVERYWHERE ALONG AND EAST OF THE JAMES RIVER VALLEY.
THE NEXT SYSTEM TO WORRY ABOUT ON TUESDAY AND TUESDAY NIGHT IS MOST
BULLISH ON THE GEM GLOBAL. SURFACE AND TEMPERATURES ALOFT STILL LOOK
COLD ENOUGH TO GIVE AN ALL SNOW EVENT. THE GEM GLOBAL WOULD GIVE THE
MOST SNOW AMOUNTS...GENERALLY IN THE 3 TO 6 INCH RANGE FOR THE
FORECAST AREA...WITH LIGHTER AMOUNTS GENERATED BY THE ECMWF AND GFS
AS THEY PLACE THE LOW WITH A MORE NORTHERLY TRACK. ONE THING FOR
CERTAIN...MUCH MORE SEASONAL NORMAL TEMPERATURES WILL PREVAIL
THROUGH THE WEEK NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 548 AM CST FRI DEC 11 2015
AREA OF MVFR CEILINGS IS HOVERING ALONG THE HIGHWAY 14 CORRIDOR
EARLY THIS MORNING FROM KHON TO KMML...BUT A BREAK NOTED AROUND
KBKX. THIS BREAK LIKELY TO PUSH BRIEFLY INTO KHON AREA LATER INTO
THE MORNING OR EARLY AFTERNOON...ALLOWING A BRIEF RETURN TO VFR
CONDITIONS. HOWEVER...LOW LEVEL WINDS WILL EVENTUALLY STEER THE
LARGER MVFR/IFR CLOUD MASS TO THE NORTH BACK INTO THE AREA DURING
THE AFTERNOON. MODELS NOT PROVIDING ANY CONSISTENT GUIDANCE ON
TIMING OF THIS...OR THAT IT EVEN EXISTS...ADDING TO THE FORECAST
CHALLENGE. RAP SEEMS TO PROVIDE THE BEST ROUGH GUIDANCE AT THIS
POINT. WOULD EXPECT THAT ONCE THE INVERTED TROUGH SLIPS PAST TAF
SITES LATER IN THE DAY AND INTO THE EVENING...NEAR SURFACE WINDS
GRADUALLY SHIFT AROUND TOWARD THE NORTH FROM EAST OR NORTHEAST
SHOULD PUSH MVFR CEILINGS SOUTHWARD WITH A BIT MORE FORCE DURING
THE OVERNIGHT PERIOD. EVEN KSUX AREA SHOULD GET IN ON THE NON VFR
CONDITIONS STARTING GRADUALLY AFTER 06Z.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHAPMAN
LONG TERM...MJ
AVIATION...CHAPMAN
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
529 AM CST FRI DEC 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST FRI DEC 11 2015
CHALLENGES THROUGH TONIGHT INCLUDE CLOUD TRENDS/TEMPERATURES...AND
DRIZZLE POTENTIAL THIS EVENING INTO THE OVERNIGHT. WILL FOLLOW A
BLEND BETWEEN THE 11.00Z NAM/ECMWF/GEM THROUGH 12Z SATURDAY WITH
THE MUCH DRIER GFS BEING AN OUTLIER IN THE SHORT-TERM.
FOR TODAY...A SURFACE TROUGH WILL DEVELOP IN THE LEE OF THE
SOUTHERN ROCKIES AND INTO THE CENTRAL PLAINS IN RESPONSE TO A
DEEPENING TROUGH ACROSS THE WESTERN CONUS. RAP RELATIVE HUMIDITY
SUGGESTS AREAS ALONG AND NORTH OF THE I-90 CORRIDOR WILL REMAIN
MOSTLY CLOUDY FOR A GOOD PORTION OF THE DAY WITH A MIX OF SUN AND
HIGHER CLOUDS FURTHER SOUTH. THESE CLOUDS...COMBINED WITH A COOLER
LOW-LEVEL THERMAL PROFILE IN THE WAKE OF YESTERDAY/S STORM SYSTEM
WILL RESULT IN TEMPERATURES 5 TO 10 DEGREES BELOW YESTERDAY/S
READINGS. AFTERNOON HIGHS WILL RANGE FROM AROUND 40 DEGREES ACROSS
NORTH-CENTRAL WI TO NEAR 50 DEGREES ACROSS PORTIONS OF NORTHEAST
IA INTO ADJACENT AREAS OF SOUTHWEST WI.
SURFACE TO 850 HPA LAYER SLOWLY SATURATES THIS EVENING/OVERNIGHT
AND WITH MODEST LIFT ALONG THE 285 TO 290 K ISENTROPIC SURFACE...
EXPECT PATCHY TO AREAS OF DRIZZLE MAINLY ALONG AND NORTHEAST OF
THE MS RIVER VALLEY. SURFACE TEMPERATURES WILL REMAIN ABOVE
FREEZING WITH LOWS MAINLY IN THE MID TO UPPER 30S...SO IMPACT WILL
BE NEGLIGIBLE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 AM CST FRI DEC 11 2015
WILL KEEP 20 POPS FOR ANY LINGERING DRIZZLE ON SATURDAY...BUT
MOST OF THE DAY SHOULD BE DRY AS PRIMARY ISENTROPIC LIFT MOVES
NORTH OF THE FORECAST AREA. SKIES WILL BE MOSTLY CLOUDY WITH
TEMPERATURES SIMILAR TO TODAY...PERHAPS A DEGREE OR TWO WARMER.
PRIMARY FOCUS WILL BE SATURDAY NIGHT THROUGH MONDAY AS AN
IMPRESSIVE STORM SYSTEM MOVES ACROSS THE UPPER MIDWEST. A STRONG
WARM FRONT WILL SURGE NORTHWARD SATURDAY NIGHT...USHERING IN VERY
WARM AND MOIST CONDITIONS FOR MID-DECEMBER. PWATS LOOK TO INCREASE
ABOVE ONE INCH SATURDAY NIGHT INTO SUNDAY...WHICH IS 3 TO 4
STANDARD DEVIATIONS ABOVE CLIMATOLOGY ACCORDING TO THE 11.00Z
NAEFS. SURFACE FRONT STALLS OUT ON SUNDAY...BISECTING THE FORECAST
AREA FROM SOUTHWEST TO NORTHEAST AND PROVIDES A FOCUS FOR
SIGNIFICANT LIFT. AS A RESULT...EXPECT PERIODS OF MODERATE TO
HEAVY RAIN SATURDAY NIGHT THROUGH SUNDAY AND SUNDAY NIGHT.
ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE MAINLY ACROSS NORTHEAST
IA INTO SOUTHWEST MN AS 0 TO 6 KM MUCAPE RISES TO BETWEEN 100 AND
300 J/KG. TOTAL RAINFALL WILL RANGE FROM 1.5 TO 2.25 INCHES. SEE
HYDROLOGY SECTION BELOW FOR POSSIBLE IMPACTS ON AREA RIVERS AND
STREAMS.
DESPITE THE CALENDAR...PRECIP WILL FALL AS ALL RAIN THROUGH
SUNDAY NIGHT AS 925 HPA TEMPERATURES CLIMB TO BETWEEN +11 AND +13
CELSIUS BY 18Z SUNDAY. EVEN WITH CLOUD COVER AND RAIN...THIS
SHOULD RESULT IN SUNDAY AFTERNOON HIGHS FROM THE MID 40S ACROSS
THE NORTHWEST TO NEAR 60 DEGREES IN THE SOUTHEAST.
PRIMARY DISAGREEMENT BETWEEN THE 11.00Z GLOBAL MODEL SUITE AT
THIS TIME IS THE SPEED IN WHICH THIS SYSTEM MOVES OUT OF THE
REGION ON MONDAY. THE GFS/NAM/GEM PLACE THE SURFACE LOW OVER LAKE
SUPERIOR BY 18Z MONDAY...WHEREAS THE ECMWF IS MUCH SLOWER WITH ITS
LOW OVER SOUTHEAST MN. THE FORMER CONSENSUS SOLUTION WOULD RESULT
IN A MUCH COLDER AIR MASS ALOFT MOVING INTO THE REGION MORE
QUICKLY...THUS INCREASING THE CHANCE FOR LINGERING PRECIP TO TURN
INTO A WINTRY MIX. AT THIS TIME...THINK VAST MAJORITY OF PRECIP
WILL OUTRUN THE COLDER AIR WITH MINIMAL IMPACT TO THE REGION.
HOWEVER...COULD STILL SEE SOME NON-ACCUMULATING SNOW FLAKES ON
MONDAY WITH HIGHS FROM THE MID 30S TO MID 40S.
ANOTHER DEEP TROUGH MOVES INTO THE NATION/S MID-SECTION BY LATE
TUESDAY/WEDNESDAY...BUT GFS/ECMWF BOTH SHOW THE MAJORITY OF
PRECIP MOVING ACROSS THE DAKOTAS INTO NORTHERN MN...KEEPING THE
FORECAST AREA WITHIN THE SYSTEM/S DRY SLOT. FOR NOW...WILL
MAINTAIN THE SUPERBLEND CHANCE POPS GIVEN THE INHERENT
UNCERTAINTIES WITH A SYSTEM ON DAYS 5-7. OF GREATER CERTAINTY FOR
NEXT WEEK...TEMPERATURES WILL FALL EACH DAY...NEARING SOMETHING
CLOSER TO MID-DECEMBER NORMALS. HIGHS WEDNESDAY/THURSDAY LOOK TO
TOP OUT IN THE UPPER 20S TO MID 30S...A SHOCK TO THE SYSTEM GIVEN
THE ABNORMAL WARMTH OF THE PAST FEW WEEKS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 529 AM CST FRI DEC 11 2015
MVFR STRATUS WRAPPED AROUND THE LOW DEPARTING INTO ONTARIO WERE
ALREADY DECREASING WEST/SOUTH OF KRST. THE DECREASE OF THIS CLOUD
DECK LOOKING TO MOVE ACROSS THE TAF SITES THRU THE EARLY/MID MORNING
HOURS AS THE SFC-850MB FLOW BECOMES MORE SOUTHWEST AND EVENTUALLY
SOUTHERLY. A PERIOD OF GOOD VFR WITH LIGHT WINDS THEN EXPECTED FOR
THE LATE MORNING THRU EARLY EVENING HOURS...AS THE AREA WILL BE
BETWEEN SYSTEMS WITH A RIDGE OF HIGH PRESSURE QUICKLY MOVING ACROSS
THE REGION.
THE INCREASING SOUTHERLY FLOW AHEAD OF THE NEXT SYSTEM TAKING SHAPE
IN THE CENTRAL PLAINS THEN SPREADS INCREASING LOW LEVEL MOISTURE INTO
THE AREA FOR THE LATER EVENING AND OVERNIGHT HOURS. THIS LOOKING TO
INITIALLY MOVE IN AS AN MVFR DECK IN THE 2000-2500 FT RANGE...LOWER
INTO THE 500-1500 FT RANGE BY LATER TONIGHT INTO SAT MORNING. THE
LOWER /500-1000 FT/IFR/ CLOUD HGTS AND SOME MVFR BR VSBYS TONIGHT
WOULD BE OVER THE HIGHER TERRAIN AREAS...WITH MORE 1000-1500 CIGS
EXPECTED FOR THE MS/WI RIVER VALLEY SITES. LIFT IN THE LOWER
SATURATED LAYER LATER THIS EVENING/OVERNIGHT NOT OVERLY STRONG...AND
LEFT ANY MENTION OF -DZ OUT OF THE TAFS FOR NOW.
&&
.HYDROLOGY...
ISSUED AT 345 AM CST FRI DEC 11 2015
TOTAL RAINFALL SATURDAY NIGHT THROUGH SUNDAY WILL RANGE FROM 1.5
TO 2.25 INCHES. RIVERS ACROSS THE REGION ARE RUNNING IN THE 90TH
PERCENTILE RANGE FOR THIS TIME OF YEAR. ALTHOUGH NO FLOODING IS
EXPECTED AT THIS TIME...PLAN ON SIGNIFICANT WITHIN BANK RISES.
THOSE WITH INTERESTS ALONG AREA RIVERWAYS ARE ENCOURAGED TO STAY
TUNED TO LATEST FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM....ROGERS
AVIATION.....RRS
HYDROLOGY....DAS/ROGERS
AREA FORECAST DISCUSSION
NWS SAN DIEGO CA
915 AM PST FRI DEC 11 2015
.SYNOPSIS...
A WINTER STORM WILL CONTINUE TO BRING COLD...WINDY WEATHER WITH
SCATTERED SHOWERS...AND A CHANCE FOR THUNDERSTORMS LATER TODAY.
SHOWERS MOVE SOUTHEAST TONIGHT...THEN FAIR AND WARMER OVER THE
WEEKEND BEFORE ANOTHER TROUGH BRINGS MORE GUSTY WINDS AND SHOWERS
SUNDAY NIGHT THROUGH MONDAY AFTERNOON. COOL BUT DRY WEATHER WILL
FOLLOW FOR TUESDAY THROUGH NEXT THURSDAY.
&&
DISCUSSION...FOR EXTREME SOUTHWESTERN CALIFORNIA INCLUDING
ORANGE... SAN DIEGO...WESTERN RIVERSIDE AND SOUTHWESTERN SAN
BERNARDINO COUNTIES...
ISOLATED SHOWERS CONTINUE ACROSS THE REGION...MOSTLY OVER AND WEST
OF THE MTNS. WINDS ARE INCREASING OUT OF THE WEST AND IS CURRENTLY
PEAKING WITH 65 MPH WINDS ACROSS THE MTN RIDGES OF RIVERSIDE AND SAN
DIEGO COUNTIES. SEVERAL LOCATIONS REPORTED WIND GUSTS OF 50 TO 66
MPH IN THE LAST SEVERAL HOURS...AND THE HIGHEST GUST WAS 52 MPH IN
THE PAST HOUR.
THE COLD FRONT WILL MOVE THROUGH OUR AREA BETWEEN 11 AM AND 2 PM.
WHILE SHOWERS WILL NOT NECESSARILY INCREASE IN NUMBER...STRONGER
DYNAMIC FORCING AND INCREASING INSTABILITY DUE TO COLD AIR ALOFT
WILL GENERATE HEAVIER SHOWERS AND ISOLATED THUNDERSTORMS. OROGRAPHIC
LIFT WILL ENHANCE PRECIPITATION ALONG THE WEST SLOPES OF THE
RIVERSIDE AND SAN DIEGO COUNTY MOUNTAINS WHERE RAINFALL AMOUNTS MAY
APPROACH ONE INCH. ELSEWHERE...RAIN TOTALS WILL BE 0.20-0.50 INCH
WEST OF THE MOUNTAINS...0.50-1.00 INCH IN THE MOUNTAINS...AND LESS
THAN 0.10 INCH IN THE DESERTS. THE SNOW LEVEL IS CURRENTLY 5500-6500
FT. THIS SHOULD DROP TO AROUND 4500-5500 FT THIS AFTERNOON...AND
EVENING. AROUND 2-4 INCHES OF SNOW ARE POSSIBLE ABOVE 7000 FT...1 TO
3 INCHES BETWEEN 6000-7000 FT...AND A TRACE TO 1 INCH AT 4500-6000
FT.
GUSTY WEST TO NORTHWEST WINDS WILL CONTINUE THROUGH TODAY. WINDS ARE
PEAKING IN THE MOUNTAINS AND DESERTS THIS MORNING...AND WILL PEAK
ALONG THE COAST LATER THIS MORNING INTO THE AFTERNOON WITH THE
PASSAGE OF THE COLD FRONT. HIGH WIND WARNINGS AND WIND ADVISORIES
REMAIN IN PLACE FOR THE MOUNTAINS...DESERTS...AND COASTAL AREAS
THROUGH THIS EVENING.
AS THE UPPER LEVEL TROUGH AXIS SHIFTS EAST TONIGHT...SUBSIDENCE
ALOFT WILL BRING AN END TO THE SHOWERS BY EARLY SAT MORNING. DRY
WEATHER WITH MARGINALLY HIGHER TEMPERATURES WILL PREVAIL FOR SAT AND
SUN UNDER A WEAK TRANSIENT HIGH PRESSURE RIDGE. ANOTHER LOW PRESSURE
TROUGH IS EXPECTED TO MOVE THROUGH SUNDAY NIGHT INTO
MONDAY...BRINGING ANOTHER ROUND OF SHOWERS AND STRONG WINDS. THIS
SYSTEM MOVES THROUGH PRETTY QUICKLY AND DOES NOT HAVE MUCH IN THE
WAY OF MOISTURE ASSOCIATED WITH IT...SO AGAIN NOT EXPECTING LARGE
RAINFALL ACCUMULATIONS. SNOW LEVELS WILL BE AROUND 4500-5500 FT WITH
THIS SYSTEM. COOL BUT DRIER WEATHER WILL PREVAIL FOR
TUESDAY...FOLLOWED BY SLOW WARMING AND WEAK OFFSHORE FLOW THROUGH
THE REMAINDER OF THE WORK WEEK.
&&
.AVIATION...
111640Z...CURRENTLY...A FEW AREAS OF LIGHT SHOWERS MOVING TO THE
SOUTHEAST...WITH BKN-SCT CLOUDS IN THE 2000-8000 FT MSL LAYER...WITH
PRIMARILY UNRESTRICTED VIS EXCEPT FOR MTN OBSCURATION OF THE COASTAL
SLOPES. CLOUDS AND SHOWERS WILL INCREASE ACROSS THE AREA...MAINLY
OVER AND WEST OF THE MOUNTAINS...THROUGH 2200-12/0000 UTC...WITH
MERGING CLOUD DECKS IN THE 2000-15000 FT MSL LAYER AND EMBEDDED ISOL
THUNDERSTORMS POSSIBLE...PRODUCING BRIEF HEAVY RAIN...LOCAL VIS AOB
1 SM...SMALL HAIL AND STRONG DOWNDRAFTS. CB TOPS TO 25000 FT MSL.
MTN OBSCURATION OF COASTAL SLOPES CONTINUING. SHOWERS AND CLOUDS
DIMINISHING 12/0000-1200 UTC...WITH MOSTLY UNRESTRICTED VIS EXCEPT
FOR POSSIBLE GROUND FOG IN SOME OF THE VALLEY AND MOUNTAIN
LOCATIONS.
STRONG W TO NW WINDS 15-30 KT WITH GUSTS 35-45 KT OVER MTN
RIDGES...THROUGH AND BELOW PASSES/CANYONS...ALONG DESERT SLOPES AND
INTO ADJACENT DESERT AREAS WILL CREATE MOD-STG UDDFS/LLWS OVER AND E
OF THE MTNS THROUGH 12/0300 UTC. ALSO...WINDS AT THE COAST COULD GET
GUSTY AS WELL...WITH 30 KT GUSTS POSSIBLE AT KSAN 2000-12/0200 UTC.
WINDS AND ASSOCIATED UDDFS/LLWS DIMINISHING AFTER 12/0300 UTC.
&&
.MARINE...
840 AM...NORTHWEST WINDS AT SAN CLEMENTE BASIN BUOY SHOW WINDS
SUSTAINED AT 16 KT AND GUSTING TO 21 KT WITH SEAS UP TO 9 FEET.
NORTHWEST WINDS WILL CONTINUE TO STRENGTHEN THIS MORNING...AND
LATEST GUIDANCE FROM THE HRRR AND WRF-EMS SHOWS WIDESPREAD GALE-
FORCE WINDS THIS AFTERNOON AND EVENING FOR BOTH THE INNER AND OUTER
WATERS...WITH WIND GUSTS OF 35 KT LIKELY. IN ADDITION...A LARGE
NORTHWEST SWELL AND STEEP SHORT-PERIOD SWELL...IN ADDITION TO
LOCALLY GENERATED WIND WAVES...WILL CREATE COMBINED SEAS 8 TO 15
FEET THIS AFTERNOON THROUGH EARLY SATURDAY. THE STRONG WINDS AND
STEEP SEAS WILL RESULT IN ROUGH AND DANGEROUS SEA CONDITIONS. A GALE
WARNING HAS BEEN ISSUED FOR BOTH THE INNER AND OUTER WATERS. SEE
LAXMWWSGX FOR DETAILS. ALTHOUGH WINDS WILL LOWER EARLY SATURDAY...
SEAS AT 10 FEET OR GREATER WILL CONTINUE THROUGH LATE SATURDAY
BEFORE LOWERING FURTHER. ISOLATED TO SCATTERED SHOWERS ARE LIKELY
TODAY...WITH A SLIGHT CHANCE FOR THUNDERSTORMS THIS AFTERNOON...WITH
POSSIBLE WATERSPOUTS. SEE THE MARINE WEATHER
STATEMENT...LAXMWSSGX...FOR MORE DETAILS.
ANOTHER LARGE 9-11 FOOT NORTHWEST SWELL WITH 8-13 SECOND PERIODS AND
STRONG NORTHWESTERLY WIND GUSTS OF 25-35 KT WILL BE POSSIBLE MONDAY
INTO EARLY TUESDAY...AS WELL AS SOME SHOWERS...AS ANOTHER STORM
SYSTEM MOVES THROUGH THE REGION.
&&
.BEACHES...
840 AM...LATEST READINGS FROM THE SAN CLEMENTE BASIN BUOY SHOWS
NORTHWEST WAVE HEIGHTS/PERIODS AT 9 FEET/14 SECONDS...WITH 7 FOOT/13
SECONDS SEAS OVER THE NEARSHORE WATERS. A LARGE LONG-PERIOD
NORTHWEST SWELL WILL BUILD TODAY AND PRODUCE HIGH SURF THROUGH
SUNDAY MORNING...WITH SURF SETS PEAKING AT 10-12 FEET THIS AFTERNOON
AND SATURDAY ALONG BEACHES NORTH OF NEWPORT BEACH IN ORANGE COUNTY
AND SETS 11 TO 13 FEET...OCCASIONALLY 15 FEET...SOUTH OF OCEANSIDE
IN SAN DIEGO COUNTY. A HIGH SURF ADVISORY REMAINS IN EFFECT FOR
ORANGE COUNTY WHILE A HIGH SURF WARNING REMAINS IN EFFECT FOR SAN
DIEGO COUNTY WHERE DAMAGING SURF COULD OCCUR.
STRONG ONSHORE WINDS AND HIGH TIDES REACHING 7 FT DURING THE MID-
MORNING HOURS FRIDAY THROUGH SUNDAY WILL COMBINE WITH THE LARGE SURF
TO THREATEN BEACHES WITH MINOR TO LOCALLY MODERATE COASTAL FLOODING
AND EROSION. FOR ADDITIONAL DETAILS...SEE THE HIGH SURF
WARNING...HIGH SURF ADVISORY AND COASTAL FLOOD ADVISORY...LAXCFWSGX.
THERE IS ALSO A SLIGHT CHANCE FOR THUNDERSTORMS AT THE BEACHES ON
THIS AFTERNOON AND POSSIBLY EARLY EVENING.
ADDITIONAL HIGH SURF IS POSSIBLE MONDAY WITH AN 11 FOOT/13 SECOND
NORTHWEST SWELL.
&&
.SKYWARN...
SKYWARN ACTIVATION IS NOT REQUESTED. HOWEVER WEATHER SPOTTERS ARE
ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS.
&&
.SGX WATCHES/WARNINGS/ADVISORIES...
CA...HIGH WIND WARNING UNTIL 10 PM PST FRIDAY FOR RIVERSIDE COUNTY
MOUNTAINS-SAN DIEGO COUNTY MOUNTAINS-SAN GORGONIO PASS NEAR
BANNING.
WIND ADVISORY UNTIL 10 PM PST FRIDAY FOR APPLE AND LUCERNE
VALLEYS-COACHELLA VALLEY-SAN BERNARDINO COUNTY MOUNTAINS-
SAN DIEGO COUNTY DESERTS.
WIND ADVISORY FROM NOON TO 8 PM PST FRIDAY FOR ORANGE COUNTY
COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
COASTAL FLOOD ADVISORY FROM 3 AM FRIDAY TO NOON PST SUNDAY FOR
ORANGE COUNTY COASTAL AREAS-SAN DIEGO COUNTY COASTAL AREAS.
HIGH SURF WARNING UNTIL 4 PM PST SUNDAY FOR SAN DIEGO COUNTY
COASTAL AREAS.
HIGH SURF ADVISORY UNTIL 4 PM PST SUNDAY FOR ORANGE COUNTY
COASTAL AREAS.
PZ...GALE WARNING UNTIL 10 AM PST SUNDAY FOR COASTAL WATERS
FROM SAN MATEO POINT TO THE MEXICAN BORDER AND OUT TO 30 NM-
WATERS FROM SAN MATEO POINT TO THE MEXICAN BORDER EXTENDING
30 TO 60 NM OUT INCLUDING SAN CLEMENTE ISLAND.
&&
$$
PUBLIC...PG
AVIATION/BEACHES/MARINE...HARRISON
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
602 PM EST FRI DEC 11 2015
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE FAIR AND WARM WEATHER INTO SUNDAY.
A WEAK FRONT WILL PROVIDE A CHANCE OF SHOWERS LATE SUNDAY NIGHT
AND MONDAY. ANOTHER FRONT TO PROVIDE A CHANCE OF SHOWERS WEDNESDAY
AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT.
SHALLOW LOW-LEVEL MOISTURE AND NOCTURNAL COOLING SHOULD HELP CAUSE
AREAS OF FOG DURING THE EARLY MORNING HOURS. THE LAMP GUIDANCE
SUGGESTED WIDESPREAD FOG BUT OTHER MODELS WERE LESS AGGRESSIVE.
THE HRRR INDICATED FOG MAINLY TO THE WEST OF THE FORECAST AREA.
LOWS NEAR OR JUST ABOVE 50 DEGREES ARE EXPECTED.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
DRY WEATHER AND ABOVE NORMAL TEMPERATURES WILL PERSIST SATURDAY
THROUGH SATURDAY NIGHT. UPPER RIDGE WILL REMAIN OVER THE
SOUTHEASTERN STATES...AS UPPER TROUGH/CLOSED LOW CROSSES THE
WESTERN CONUS. THIS WILL LEAD TO A CONTINUED WARMING TREND FOR
OUR REGION. SURFACE HIGH PRESSURE CENTERED OVER NORTHERN FLORIDA
WILL LIFT NORTH TOWARDS THE CAROLINAS SATURDAY. FAVORED WARMER
TEMPERATURES INDICATED BY THE MAV MOS WITH HIGHS IN THE MID TO
UPPER 70S AND LOWS IN THE UPPER 40S TO LOWER 50S.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
THE UPPER-LEVEL RIDGE AND SURFACE HIGH PRESSURE WILL MOVE OFF THE
COAST SUNDAY AS AN UPPER LOW LIFTS NORTHEAST FROM THE GREAT PLAINS
INTO THE GREAT LAKES REGION SUNDAY INTO MONDAY. THIS WILL DRAG A
FRONTAL BOUNDARY THROUGH THE FORECAST AREA MONDAY. PRECIPITATION
TO OUR WEST ALONG THE FRONT EXPECTED TO WEAKEN AS IT APPROACHES
OUR REGION AS BEST UPPER DYNAMICS SHIFT TO THE NORTH. INCREASING
LOW-LEVEL SOUTHERLY FLOW/ISENTROPIC LIFT TO DEVELOP OVER OUR
REGION LATE SUNDAY NIGHT AHEAD OF THE APPROACHING WEAK FRONT.
SURFACE AND ELEVATED INSTABILITIES PROGGED TO BE QUITE WEAK ACROSS
THE MIDLANDS AND CSRA...THUS NO MENTION OF THUNDER.
HIGH CHANCE TO LOW LIKELY POPS CONTINUE WITH THE FRONTAL PASSAGE
MONDAY. DRY HIGH PRESSURE WILL BUILD INTO THE REGION MONDAY NIGHT
INTO TUESDAY. ABOVE NORMAL TEMPS WILL CONTINUE TUESDAY GIVEN
SOUTHWEST FLOW ALOFT WITH WEAK UPPER RIDGING OVER THE SOUTHEASTERN
STATES.
GFS/ECMWF IN AGREEMENT WITH UPPER TROUGH MOVING EAST INTO THE
CENTRAL CONUS...WITH UPPER RIDGE SHIFTING TO OUR EAST WEDNESDAY.
SURFACE FRONT PROGGED TO CROSS THE AREA THURSDAY. STILL SOME
TIMING DIFFERENCES WITH THE GFS INDICATING THE FROPA THURSDAY AND
THE ECMWF SLOWER...INDICATING THE FRONT MOVING EAST OF THE AREA
FRIDAY. INCREASING MOISTURE/ISENTROPIC LIFT AHEAD OF THE FRONT MAY
LEAD TO SOME LIGHT PRECIP WEDNESDAY AFTERNOON AND WEDNESDAY NIGHT.
GIVEN MODEL DIFFERENCES WILL KEEP CHANCE OF SHOWERS THURSDAY INTO
FRIDAY. ABOVE NORMAL TEMPERATURES WILL CONTINUE THROUGH
THURSDAY...COOLING TO THE 50S FOR FRIDAY.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
WEAK HIGH PRESSURE WILL REMAIN OVER THE REGION THROUGH TONIGHT.
SHALLOW LOW-LEVEL MOISTURE AND NOCTURNAL COOLING SHOULD HELP CAUSE
AREAS OF FOG DURING THE EARLY MORNING HOURS. THE LAMP GUIDANCE
SUGGESTED WIDESPREAD IFR FOG BUT OTHER MODELS WERE LESS
AGGRESSIVE. THE HRRR INDICATED FOG MAINLY TO THE WEST OF THE
FORECAST AREA. USED AN AVERAGE OF THE GUIDANCE AND FORECASTED MVFR
FOG EXCEPT THE ADDED MOISTURE AND COOLING IN THE RIVER VALLEY
SUPPORT IFR FOG AT AGS. HEATING AND MIXING SHOULD RESULT IN A
RETURN TO VFR CONDITIONS BEGINNING AROUND 14Z.
EXTENDED AVIATION OUTLOOK...A WEAK FRONT MOVING INTO THE AREA
EARLY NEXT WEEK MAY BRING RESTRICTIONS.
&&
.CLIMATE...
FORECAST MAX TEMPS SAT/SUN
CAE...77/79
AGS...78/79
NORMAL MAX TEMPS SAT/SUN
CAE...59/59
AGS...61/60
RECORD MAX TEMPS SAT/SUN
CAE...81/80
AGS...82/81
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
&&
$$
SYNOPSIS...99
NEAR TERM...99
SHORT TERM...99
LONG TERM...99
AVIATION...99
CLIMATE...
AREA FORECAST DISCUSSION
National Weather Service Lincoln IL
239 PM CST FRI DEC 11 2015
.SHORT TERM...(Tonight)
ISSUED AT 239 PM CST FRI DEC 11 2015
Overcast low clouds below 2k ft and patchy fog and drizzle lifting
northward from southern into central IL and reaching north of
Lincoln by mid afternoon. These low clouds and will overspread rest
of northern CWA next few hours. HRRR model has been handling this
quicker timing of arrival of IFR clouds well and even have a few
sites with vsbys below 1 mile with Paris the lowest at 1/2 mile in
fog. South to southeast winds advecting low level moisture northward
into central IL this afternoon and this to continue tonight with
patchy drizzle as well. Continue slight chances of light rain
showers over central and eastern IL tonight though mostly a trace
event tonight.
A 1000 mb surface low pressure over southeast Nebraska will weaken
to 1010 mb as it moves into south central IA by dawn Sat. One warm
front near I-74 to lift into northern IL tonight while another warm
front near I-70 will slowly lift northward across central IL
tonight. Weak lift along with boundary to develop very light
precipitation along with areas of fog and patchy drizzle especially
east of the IL river with very moist low levels from surface up to
850 mb. SSE winds 5-10 mph and low clouds will not allow temps to
drop too much tonight. Unseasonably mild lows range from around 50F
nw of the IL river to the upper 50s in southeast IL from I-70
southeast.
&&
.LONG TERM...(Saturday through Friday)
ISSUED AT 239 PM CST FRI DEC 11 2015
Models finally in better agreement with timing of the approaching
system for this weekend. However, all models still have trended a
little slower with the system as it moves into and through the CWA.
Before the main system gets here, light, warm advection type pcpn
will move across the state during the day on Sat. This will include
cloudy skies and much warmer temps...with some sites reaching or
exceeding record temps. Then the main punch of the pcpn will begin
late Sat night and continue through Sunday and Sun night. Models
have also trended with less pcpn through the period, but still
showing around an inch in the east and over 1.5 inches west of I-55.
The heaviest pcpn looks to be Sun afternoon and Sun evening. The
pcpn will diminish on Monday, with just chance pops for mainly Mon
morning. By afternoon, things should push to the east and northeast.
Besides the record warmth on Sat, Sunday highs will also be quite
warm...well above normal for middle of Dec. Once the system moves
through, temps will decrease but still be above normal.
The main focus for next week, Mon night through Friday, will be the
slightly cooler temps and then the decreasing temps back to normal
for later in the week. With the upper level flow remaining
southwesterly in the extended, another wave or two will move
northeast through the flow. However, with the gulf being blocked,
there should be limited moisture in the area for any weak system to
work with. So, only slight chc pops expected for when the weak wave
moves through, which will be Tue night through Wed night. Besides
this, dry weather is expected most of the area through most of the
week.
Temps will stay above normal through about Wed and then fall to
around normal for the end of the week.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1155 AM CST FRI DEC 11 2015
Broken to overcast mid/high clouds of 15-20k ft blanket central IL
this afternoon. Expect MVFR clouds 1-2k ft to spread northward
into central IL, reaching I-72 between 22-24Z and PIA and BMI
23Z-01Z. Ceilings to lower below 1k ft by mid evening along with
drizzle and fog reducing vsbys to MVFR 3-5 miles and lower to 1-2
miles and possibly lower overnight into mid morning Saturday.
Warm front over central IL near I-74 to slowly lift northward into
northern IL during tonight as 999 mb low pressure along the
eastern NE/KS border lifts into central IA by 12Z Sat and weakens
to 1010 mb. SSE winds of 6-11 kts this afternoon to veer SSW
during tonight into Sat morning and be near 10 kts.
&&
.CLIMATE...
ISSUED AT 300 AM CST FRI DEC 10 2015
Record highs for the weekend:
Location Today Saturday Sunday
DEC 11 DEC 12 DEC 13
---------- --------- --------- ---------
Bloomington 65 (1949) 65 (1896) 63 (1975)
Champaign 64 (1949) 62 (1991) 64 (1975)
Charleston 66 (1931) 67 (1949) 64 (1991)
Decatur 65 (1949) 65 (1929) 66 (1975)
Effingham 60 (1979) 67 (1929) 65 (1991)
Lincoln 66 (1949) 64 (1929) 64 (1975)
Peoria 64 (1949) 62 (1991) 63 (1975)
Springfield 67 (1949) 64 (1929) 67 (1948)
&&
.ILX Watches/Warnings/Advisories...
NONE.
&&
$$
SHORT TERM...07
LONG TERM...Auten
AVIATION...07
CLIMATE...Geelhart
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
343 PM CST FRI DEC 11 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 340 PM CST FRI DEC 11 2015
THE SHORT TERM IS DEFINITELY THE CALM BEFORE THE STORM WITH THE BIG
CHANGE MADE THROUGH THE DAY SATURDAY BEING TO REDUCE POPS THROUGHOUT
THE PERIOD.
THIS AFTERNOON...THE SFC RIDGE THAT WORKED ACROSS MN THIS MORNING IS
NOW WORKING ACROSS WI...WITH EASTERLY LOW LEVEL WINDS SETTING UP AS
LEE CYCLOGENESIS SLOWLY EVOLVES ACROSS COLORADO. LEAD SHORTWAVE
EMANATING FROM THE MAIN WRN THROUGH IS WORKING ACROSS CENTRAL NODAK
THIS AFTERNOON AND IS ON ITS WAY FOR SOUTHERN MANITOBA. PRECIP
ASSOCIATED WITH THIS WAVE HAS BEEN TIED TO MOISTURE AND ISENTROPIC
LIFT ON THE 295K SFC...AND THE RAP SHOWS THIS AREA OF
FORCING/MOISTURE HEADING FOR NW MN...SO REMOVED WHAT LITTLE POPS WE
HAD FOR TODAY AND THIS EVENING ACROSS WESTERN AND CENTRAL MN.
LATER TONIGHT...WE WILL SEE ANOTHER AREA OF PRECIP PUSH NORTH ON THE
LEADING EDGE OF THE FIRST MOISTURE SURGE. THERE WILL LIKELY BE AN
AREA OF DRIZZLE/LIGHT RAIN ASSOCIATED WITH IT...BUT PRIMARY MOISTURE
TRANSPORT AT 925MB WILL BE GOING FROM EASTERN IOWA TOWARD THE
MICH/WI BORDER. AS A RESULT...KEPT THE FORECAST DRY FOR TONIGHT
ACROSS THE ENTIRE MPX CWA...AS ANY DZ/RA PRODUCTION LOOKS TO OCCUR
SOUTHEAST OF OUR FORECAST AREA.
FOR SATURDAY...CONTINUED THE TREND OF DRYING THE FORECAST AS
WELL...AS GUIDANCE IS IN GOOD AGREEMENT ON THE BULK OF THE PRECIP
WITH THIS WEEKENDS SYSTEM COMING AFTER 00Z SUNDAY /SATURDAY
EVENING/. THE ONE EXCEPTION IS THE DEVELOPMENT OF A BAND OF ELEVATED
FGEN IN THE H7-H6 LAYER SATURDAY AFTERNOON. MOST GUIDANCE...CAM AND
NON-CAM ALIKE...SHOW A BAND OF PRECIP DEVELOPING IN WRN MN AND
WORKING UP TO CENTRAL MN DURING THE AFTERNOON...SO THIS WAS WHERE
PRECIP MENTION WAS MAINTAINED...EVERYWHERE ELSE WE KEPT DRY UNTIL WE
GET INTO SATURDAY EVENING...WHEN THINGS LOOK TO GO DOWNHILL PRETTY
QUICK. LOOKS PLENTY WARM ENOUGH SATURDAY AFTERNOON TO KEEP THE VAST
MAJORITY OF THE PRECIP WE SEE AS RAIN...THOUGH WE MAY SEE A
SNOWFLAKE OR TWO MIX IN OUT TOWARD ALEXANDRIA. WITH RAIN EXPECTED TO
DOMINATE...REMOVED ANY SNOW ACCUMULATIONS FROM SATURDAY AS WELL.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 PM CST FRI DEC 11 2015
WIDESPREAD RAIN IS STILL ON TRACK FOR THE WEEKEND INTO MONDAY WITH
1-3 INCHES OF RAIN IN THE EASTERN FORECAST AREA...TAPERING TO
ABOUT A HALF INCH OF LIQUID IN WESTERN MN. AT THIS POINT...WESTERN
MN IS THE MOST SUSCEPTIBLE TO A FEW INCHES OF SNOW GIVEN THE
COOLER TEMPERATURE PROFILE IN THIS AREA.
THE NAM AND ECMWF HAVE BEEN DIALED IN WITH ONLY SMALL WOBBLES IN
THE SURFACE LOW TRACK OVER THE PAST 3 RUNS GOING BACK TO LAST
NIGHT. THE GFS HAS SHOWN A LITTLE MORE RUN-TO-RUN VARIABILITY OVER
THE PAST 3-4 RUNS. AS PREVIOUS DISCUSSIONS HAVE MENTIONED...THE
FORECAST LOW TRACK HAS THE LOOK OF A MAJOR WINTER STORM...ITS
SIMPLY TOO WARM. BOTH THE 60HR CIPS ANALOG FROM THE NAM AND THE
72HR ANALOG FROM THE GFS SUGGEST WE SHOULD BE GETTING READY TO
ISSUE WINTER STORM WATCH HEADLINES ACROSS MOST OF OUR MINNESOTA
COUNTIES...AGAIN NOT EVEN CLOSE WITH THESE TEMPERATURES. WHAT WE
ARE CONFIDENT IN...IS WIDESPREAD 1"+ RAIN TOTALS ACROSS EASTERN
MN AND WESTERN WI. WE NOW HAVE 100% RAIN IN THE FORECAST FOR
SEVERAL PERIODS SAT-MON. SOUTHEAST MN AND WESTERN WI COULD GET A
FEW RUMBLES OF THUNDER AS WELL.
THE MODEL CONSENSUS IS FOR A LOW TRACK OUT OF THE SOUTHERN PLAINS
ACROSS NORTHEAST IA AND INTO NORTHERN WI FROM SATURDAY NIGHT INTO
MONDAY MORNING. THERE WILL BE TWO MAIN BURSTS OF PRECIP...THE
FIRST IS WITH THE MOISTURE SURGE AND ISENTROPIC LIFT SATURDAY
NIGHT...FOLLOWED BY A RELATIVE LULL...AND THE SECOND SURGE SUNDAY
MORNING/AFTERNOON WITH THE CLASSIC FLUID DEFORMATION - THIS LINGERS
INTO MONDAY. THE ONE AREA OF CONCERN IS IN WESTERN MN...WHERE SOME
OF THE MODEL GUIDANCE HAS TRENDED A BIT COOLER. AS IT STANDS
NOW...WE ARE FORECASTING 1-3" OF SNOW NEAR AND WEST OF A LINE FROM
GRANITE FALLS...TO SAUK CENTRE...TO STAPLES - WITH A WINTRY MIX OF
PRECIP. THE COLD SIDE OF THIS SYSTEM ISNT AS COLD AS WE MIGHT
EXPECT...WHICH IS WHY WE AREN`T GOING WITH HIGHER SNOW TOTALS AT
THIS POINT. HOWEVER...STRONG SYSTEMS LIKE THIS THAT DEEPEN AS
THEY LIFT OUT OF THE PLAINS CAN DYNAMICALLY LOWER THE FREEZING
LEVEL AND GIVE YOU A QUICKER CHANGEOVER TO SNOW. IF THAT WERE TO
HAPPEN...LOCATIONS SUCH AS ALEXANDRIA...GRANITE FALLS AND BENSON
COULD END UP WITH SEVERAL INCHES OF SNOW - MAYBE AS MUCH AS 6". WE`LL
CONTINUE TO WATCH OUR WESTERN MN AREA CLOSELY. THE FORECAST
SOUNDINGS DEFINITELY SHOW MORE SLEET IN THESE AREAS AS WELL
BECAUSE THEY HAVE COOLED BUT CONTINUE TO SHOW A WARM LAYER ALOFT.
THE TRAILING SYSTEM TUESDAY NIGHT AND WEDNESDAY STILL LOOKS
COOLER WITH A BETTER CHANCE FOR SNOW. IT HAS A VERY SIMILAR TRACK
TO THE WEEKEND STORM...HOWEVER...IT IS ALSO DRIER AND FASTER. WE
WILL LEAVE IT THERE AND TAKE THIS ONE SYSTEM AT A TIME.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1206 AM CST FRI DEC 11 2015
SFC RIDGE AT 18Z WAS CENTERED ALONG THE MN/WI BORDER. THIS HAS
RESULTED IN LIGHT WINDS AND LIMITED MIXING ALL DAY...WITH THE LOW
STRATUS SLOW TO BUDGE AS A RESULT. FOLLOWED MORE THE HRRR FOR CIGS
THIS AFTERNOON/EVENING AS OPPOSED TO THE OVERLY OPTIMISTIC LAMP
GUIDANCE. ALLOWED VFR CONDITIONS IN SRN WI TO COME INTO ERN
MN...BUT LOOKS UNLIKELY THEY WILL REACH TERMINALS WEST OF MSP.
TONIGHT...WE WILL SEE A SURGE OF LOW LEVEL MOISTURE COME UP FROM
THE SOUTH AND HAVE HIGH CONFIDENCE THAT IT WILL SEND CIGS BACK
DOWN TO IFR/LIFR LEVELS AREAWIDE AND THE LAMP GUIDANCE LOOKS
REASONABLE FOR BRINGING THIS SURGE OF MOISTURE INTO THE TERMINALS.
LESS CONFIDENCE ON WHAT THIS MOISTURE SURGE MEANS FOR VIS...BUT FG
WILL BE A THREAT TO WATCH AT AXN AND POSSIBLY RWF. ONCE THESE LOW
CLOUDS ARRIVE LATE TONIGHT...THEY WILL BE WITH US LIKELY INTO THE
DAY ON MONDAY...THOUGH PRECIPITATION LOOKS TO HOLD OFF UNTIL
AFTER 18Z IN WRN/CENTRAL MN AND AFTER 00Z SUNDAY EVERYWHERE ELSE.
KMSP...HAVE MAINTAINED CONTINUITY WITH THE TAF IN SHOWING A BRIEF
WINDOW OF VFR CIGS...THOUGH THE LONGER IT TAKES FOR THESE
IMPROVEMENTS TO MOVE NORTH OUT OF SRN WI/NRN IOWA...THE GREATER
THE CHANCE THAT MSP NEVER SEES THIS IMPROVEMENT AND REMAINS STUCK
WITH CIGS UNDER 017 FOR LIKELY THE ENTIRE WEEKEND. IF
ANYTHING...CIG FORECAST FOR LATE TONIGHT INTO SATURDAY MORNING IS
A BIT OPTIMISTIC...WITH CIGS DOWN UNDER 500 FEET NOT OUT OF THE
QUESTION COME SATURDAY MORNING.
/OUTLOOK FOR KMSP/
SUN...IFR WITH PERIODS OF RA. WINDS NE TO N 10-15 KTS.
MON...MVFR/IFR. -RA/-SN POSSIBLE EARLY. WINDS NW 15-20 KTS.
TUE...VFR EARLY. MVFR/IFR WITH CHC -SN LATE. WINDS E 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...MPG
LONG TERM...CLF
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1206 PM CST FRI DEC 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST FRI DEC 11 2015
IN THE WAKE OF A STORM SYSTEM THAT BROUGHT RAIN TO CENTRAL/SOUTHERN
MN AND WC WI ON THURSDAY...CAA AND RESIDUAL MOISTURE BLW 5K PROVIDED
LOWER CLDS AND SOME FOG TO THE AREA OVERNIGHT. TEMPS EARLY THIS
MORNING ARE STILL VERY MILD WITH 30S ACROSS THE AREA.
THE MAIN FORECAST CONCERN TODAY/TONIGHT IS WHETHER SOME -SN...MIXED
WITH -RA DEVELOPS IN WC/CENTRAL MN DURING THE LATE AFTN/EVENING HRS
AS A WEAK SHRTWV MOVES NE ACROSS THE DAKOTAS AND INTO NW MN. DEEP
MOISTURE IS THE MAIN PROBLEM WITH THIS SYSTEM AS WAA DEVELOPS AHEAD
OF THIS SHRTWV. THEREFORE...IT IS LIKELY THAT NOTHING MORE THAN A
FEW FLURRIES OR SPRINKLES WILL OCCUR IN WC/CENTRAL MN DURING THE
AFTN/EVENING. EVEN THE LATEST HRRR/RAP DOESN/T SUPPORT ANYTHING MORE
THAN A HUNDREDTH OF AN INCH OF LIQUID WATER IN CENTRAL MN. TEMPS
WILL BE WARMEST ALONG THE IA/MN BORDER WHERE SOME SUNSHINE IS
POSSIBLE. W/NW WINDS WILL BECOME E/SE LATER THIS AFTN/EVENING AHEAD
OF THIS WX SYSTEM. THIS WILL STALL THE CLDS THIS MORNING ALONG THE
IA/MN BORDER...AND BRING THEM BACK NORTH/NW AS BOUNDARY LAYER WINDS
BEGIN TO SHIFT TO THE EAST/SE. IF MORE SUNSHINE DEVELOPS...TEMPS
THIS AFTN WILL REACH 50 DEGREES ALONG THE IA/MN BORDER...WITH 40S AS
FAR NORTH AS THE TWIN CITIES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 350 AM CST FRI DEC 11 2015
THE LONG TERM FORECAST CONTINUES TO FEATURE MULTIPLE CHANCES FOR
PRECIPITATION...ALTHOUGH THE CHANCE OF SNOW HAS DECREASED FOR MOST
OF THE FORECAST AREA UNTIL TUESDAY OF NEXT WEEK.
MID LEVEL HEIGHTS WILL BE ON THE INCREASE AT THE START OF THE LONG
TERM PERIOD ON SATURDAY AS THE SOUTHWESTERN CONUS UPPER TROUGH
FURTHER AMPLIFIES. ANY PRECIP PRIOR TO SATURDAY EVENING SHOULD BE
PRETTY FAINT...WITH ROBUST FORCING NOT LIFTING INTO THE AREA UNTIL
CLOSER TO 06Z SUNDAY. BY THAT TIME...H85 TEMPS ARE PRIMARILY
FORECAST TO BE IN THE +1C TO +6C RANGE OVER THE FORECAST AREA.
THEREFORE EXPECT THE BULK OF THE PRECIP TO BE IN THE FORM OF RAIN
ACROSS ALL BUT POSSIBLY THE VERY FAR WEST CENTRAL MN COUNTIES. BY
THE TIME COLD ENOUGH AIR FEEDS INTO THE AREA OVERNIGHT INTO
MONDAY...THE PRECIPITATION WILL BE WINDING DOWN. HAVE THEREFORE
REDUCED FORECAST SNOWFALL AMOUNTS TO ZERO FROM THE TWIN CITIES
DOWN TO FAIRMONT...EAST ACROSS WI. TO THE WEST...HALF TO ONE INCH
AMOUNTS SEEM REASONABLE.
THE NEXT TROUGH IN THE SOUTHERN STREAM PARADE LIFTS INTO THE AREA
BY TUESDAY. THIS SYSTEM WILL DIFFER IN THAT IT IS PROGGED TO BE
ACCOMPANIED BY A STRONGER SURFACE REFLECTION...AND IS A BIT
COLDER. THERE ARE STILL NOTABLE SPATIAL/TEMPORAL DIFFERENCES
BETWEEN THE GFS AND ECMWF...BUT BOTH WOULD FAVOR SNOW AS THE
PRIMARY PRECIP TYPE.
THE OTHER MAIN HIGHLIGHT IN THE LONG TERM IS THAT BY THE END OF
THE UPCOMING WEEK TEMPERATURES WILL HAVE RETREATED BACK CLOSER TO
NEAR NORMAL VALUES. HIGHS THURSDAY SHOULD BE IN THE LOW/MID 20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1206 AM CST FRI DEC 11 2015
SFC RIDGE AT 18Z WAS CENTERED ALONG THE MN/WI BORDER. THIS HAS
RESULTED IN LIGHT WINDS AND LIMITED MIXING ALL DAY...WITH THE LOW
STRATUS SLOW TO BUDGE AS A RESULT. FOLLOWED MORE THE HRRR FOR CIGS
THIS AFTERNOON/EVENING AS OPPOSED TO THE OVERLY OPTIMISTIC LAMP
GUIDANCE. ALLOWED VFR CONDITIONS IN SRN WI TO COME INTO ERN
MN...BUT LOOKS UNLIKELY THEY WILL REACH TERMINALS WEST OF MSP.
TONIGHT...WE WILL SEE A SURGE OF LOW LEVEL MOISTURE COME UP FROM
THE SOUTH AND HAVE HIGH CONFIDENCE THAT IT WILL SEND CIGS BACK
DOWN TO IFR/LIFR LEVELS AREAWIDE AND THE LAMP GUIDANCE LOOKS
REASONABLE FOR BRINGING THIS SURGE OF MOISTURE INTO THE TERMINALS.
LESS CONFIDENCE ON WHAT THIS MOISTURE SURGE MEANS FOR VIS...BUT FG
WILL BE A THREAT TO WATCH AT AXN AND POSSIBLY RWF. ONCE THESE LOW
CLOUDS ARRIVE LATE TONIGHT...THEY WILL BE WITH US LIKELY INTO THE
DAY ON MONDAY...THOUGH PRECIPITATION LOOKS TO HOLD OFF UNTIL
AFTER 18Z IN WRN/CENTRAL MN AND AFTER 00Z SUNDAY EVERYWHERE ELSE.
KMSP...HAVE MAINTAINED CONTINUITY WITH THE TAF IN SHOWING A BRIEF
WINDOW OF VFR CIGS...THOUGH THE LONGER IT TAKES FOR THESE
IMPROVEMENTS TO MOVE NORTH OUT OF SRN WI/NRN IOWA...THE GREATER
THE CHANCE THAT MSP NEVER SEES THIS IMPROVEMENT AND REMAINS STUCK
WITH CIGS UNDER 017 FOR LIKELY THE ENTIRE WEEKEND. IF
ANYTHING...CIG FORECAST FOR LATE TONIGHT INTO SATURDAY MORNING IS
A BIT OPTIMISTIC...WITH CIGS DOWN UNDER 500 FEET NOT OUT OF THE
QUESTION COME SATURDAY MORNING.
/OUTLOOK FOR KMSP/
SUN...IFR WITH PERIODS OF RA. WINDS NE TO N 10-15 KTS.
MON...MVFR/IFR. -RA/-SN POSSIBLE EARLY. WINDS NW 15-20 KTS.
TUE...VFR EARLY. MVFR/IFR WITH CHC -SN LATE. WINDS E 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
&&
$$
SHORT TERM...JLT
LONG TERM...LS
AVIATION...MPG
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
339 PM CST FRI DEC 11 2015
.SHORT TERM: (Through Late Tonight)
Issued at 336 PM CST Fri Dec 11 2015
Forecast problem for tonight is sky cover and possibility of fog.
Low clouds have mostly cleared out of central Missouri, but are
hanging tough across eastern Missouri and much of southern and
central Illinois. Model guidance has been less than helpful so far
in forecasting these low clouds...though the HRRR has been the best
so far. HRRR has the low clouds continuing to push northeast this
evening, but high clouds will likely persist over the area. The net
effect for the public forecast will still be a mostly cloudy to
cloudy sky regardless of what the low clouds ultimately decide to
do. While there could be some fog tonight, boundary layer winds
look too strong to support truly dense fog...except possibly over
the eastern Ozarks. However, it`s more likely that low visibility
will be caused by low clouds which are forecast to redevelop over
the higher terrain. South-southwest flow combined with clouds will
keep lows well above normal tonight. MOS guidance in the low to mid
50s looks very reasonable.
Carney
.LONG TERM: (Saturday through Next Friday)
Issued at 336 PM CST Fri Dec 11 2015
(Saturday through Monday)
Operational models are showing a slightly slower motion of the upper
low toward the area over the weekend which will result in a slower
onset of the steadier showers on Saturday night and Sunday. Before
then, still expect chances of light rain to increase during the day
on Saturday as transport of moisture from the Gulf increases via
40kt low level jet. Then showers and scattered thunderstorms will
spread across the area on Saturday night and Sunday as strong
moisture convergence moves from west to east across the area
under enhanced ascent caused by negatively tilting mid level
trough. The rain will continue into Sunday night before ending
during the day Monday as the trough lifts out of the area.
While temperatures will cool off slightly over the weekend because
of the rain, they will remain above normal because of the warm
sector. There will not be much of diurnal swing because of the
clouds and rain.
(Tuesday through Friday)
The GFS and ECMWF are depicting similar solutions to yesterday with
an upper low moving from the southern Rockies into the Great Lakes
at midweek. Most of the dynamics look to be staying to the
northwest of our area with this system, and the most of the moisture
will be staying to the south, so precipitation will be limited. The
system will still pull a cold front through the area on Wednesday
with 850mb temperatures falling to around -10C on the ECMWF by
Friday behind it. This still confirms that temperatures will go
from well above normal on Tuesday to near mid December normals by
Friday.
Britt
&&
.AVIATION: (For the 18z TAFs through 18z Saturday Afternoon)
Issued at 1141 AM CST Fri Dec 11 2015
Primary challenge remains low ceilings and visibilities across
much of southeast Missouri and southern Illinois. It`s difficult
to track the northward progress using satellite due to higher
clouds obscuring the low stuff, but It does look like the IFR
ceilings are continuing to move north-northwest based on
observations and breaks in the higher clouds. High resolution
short-range guidance is bearing this out so far, so I expect much
of east central and southeast Missouri as well as parts of west
central and southwest Illinois to get the low stratus through the
afternoon. Guidance indicates improving conditions late this
afternoon into the evening...but there is the potential for
stratus to redevelop overnight tonight. If this occurs, expect
ceilings to be at or below 1000 FT and the low stratus to persist
through much of Saturday morning.
Specifics for KSTL:
Expect gradually improving flight conditions at Lambert this
afternoon...tho I think it unlikely the ceilings will get above
IFR before 22Z...perhaps even closer to 00Z. Pretty much only one
piece of model guidance is handling this situation with any degree
of accuracy, so I`m following that relatively closely. This
guidance actually brings ceilings up to VFR after 00Z...however I
think this is unlikely since MVFR ceilings stretch well south
through the Mississippi Valley. Latest thinking is that ceilings
will stay between 1000-1500 this evening with gradual lowering
back to IFR late tonight. Think IFR conditions are likely to
prevail at least through Saturday morning.
Carney
&&
.CLIMATE:
Record max temps through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 70/1979 70/1991 73/1948
COU 73/1949 74/1889 75/1948
UIN 69/1949 67/1991 67/1948
Record hi lows through the weekend...
FRI 12/11 SAT 12/12 SUN 12/13
STL 53/1965 55/1929 56/1889
COU 55/1965 46/1929 55/1889
UIN 55/1965 42/1991 50/1927
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
358 PM CST FRI DEC 11 2015
.SYNOPSIS...
ISSUED AT 357 PM CST FRI DEC 11 2015
12Z OBJECTIVE ANALYSIS SUGGESTS THE LONG WAVE TROUGH IS CENTERED
SOUTHWEST OF THE MOGOLLON RIM WITH A LEAD DISTURBANCE NEAR THE 4
CORNERS. BROAD RIDGING ENCOMPASSES MUCH THE CORNBELT AND
SOUTHEASTERN US...WITH A CLOSED LOW NORTH OF NEW ENGLAND. ANALYSIS
OF THE 12Z RAOBS SHOWED THE 12Z NAM INITIALIZED TOO WARM ACROSS THE
SOUTHWESTERN STATES...SUGGESTING THE TROUGH COULD DIG FURTHER SOUTH.
AT THE SURFACE...A MODIFIED CONTINENTAL ARCTIC FRONT HAS PUSHED INTO
NORTHERN NEBRASKA. KVTN AND KANW ARE CURRENTLY /21Z/ AT 32 AND 33
DEGREES FAHRENHEIT RESPECTIVELY...WHEREAS LOCATIONS ALONG AND
SOUTHEAST OF A KONL TO KTIF TO KOGA LINE ARE ALL IN THE 40S AND 50S.
STRATUS HAS DRIFTED SOUTH ACROSS NORTHERN NEBRASKA THIS
AFTERNOON...WITH HIGH CLOUDS ACROSS OUR SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 357 PM CST FRI DEC 11 2015
TONIGHT AND TOMORROW. THE SHORT RANGE MODELS CONTINUE TO STRUGGLE
WITH RUN TO RUN CONSISTENCY...BUT ARE BEGINNING TO COME INTO BETTER
AGREEMENT. THE CURRENT FORECAST TRACKS THE MAIN H5 LOW FURTHER
SOUTH...NOW MORE IN LINE WITH THE EURO WHICH FAVORS A DELAYED ONSET
OF QPF ACROSS THE FORECAST AREA. THE MODELS REMAIN FIXED HOWEVER
THAT A COUPLED JET WILL INTERACT WITH A MID LEVEL FGEN BAND AND
ISENTROPIC UPGLIDE WITHIN THE 290-300K SURFACES TO EVENTUALLY
PRODUCE SNOW ACROSS NW NEBRASKA AND PORTIONS OF THE ADJACENT
SANDHILLS BEGINNING AROUND 12Z SATURDAY. CONDENSATION PRESSURE
DEFICITS ARE SHOWN TO LOWER TO 1MB...ACCUMULATING SNOWFALL IS
ANTICIPATED. THE HEAVIEST ACCUMULATIONS ARE ANTICIPATED AFTER 18Z
SATURDAY ACROSS NORTHWEST NEBRASKA WHERE AN INCH OR TWO OF SNOW WILL
FALL BEFORE 00Z. OTHER LOCATIONS ACROSS THE NORTHWEST SANDHILLS
/WEST OF A KVTN TO KOGA LINE/ WOULD EXPECT UPWARDS TO AN INCH BEFORE
00Z SUNDAY. WITH ACCUMULATIONS ANTICIPATED BEYOND 00Z SUNDAY...WE
WILL ISSUE A WINTER WEATHER ADVISORY FOR OUR FAR WESTERN COUNTIES
FROM 12Z THROUGH 18Z SUNDAY.
THE PREVIOUS FORECAST HAD A MENTION OF FZDZ OR FREEZING RAIN DURING
THE AFTERNOON HOURS SATURDAY. THERE REMAINS FAR TOO MANY VARIABLES
THAT NEED TO COME INTO PLAY BEFORE ANY FREEZING PRECIPITATION IS
REALIZED. WITH THE LATEST RUNS TRENDING SOUTH...WE FELT COMFORTABLE
REMOVING THE FREEZING PRECIP FROM THE FORECAST. NOTE 12Z NAM BUFR
SOUNDINGS STILL SHOW A BRIEF PERIOD FOR ICING TOMORROW AFTERNOON
EAST OF HIGHWAY 83...BUT THE 18Z MODEL RUN BACKED OFF LIKE THE
OTHERS.
THE INCREASING STRATUS WILL HELP KEEP TEMPERATURES WARMER THAN WHAT
GUIDANCE IS PROJECTING. WE USED A SMALL BLEND OF THE MET/MAV WITH
THE PREVIOUS FORECAST WHICH ONLY LOWERED MIN T/S A COUPLE DEGREES.
IF SIGNIFICANT CLEARING REMAINS...THEN OUR T/S ARE AMBITIOUSLY
HIGH.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 357 PM CST FRI DEC 11 2015
SNOW CHANCES CONTINUE SATURDAY NIGHT INTO SUNDAY AS AN UPPER
LEVEL TROUGH CURRENTLY CROSSING CALIFORNIA NEVADA DEEPENS AND
CLOSES OFF EAST OF THE 4 CORNERS REGION SATURDAY EVENING. THE
UPPER LOW THEN FCST TO TRACK INTO THE OKLA/TX PNHDL REGION BY
12Z SUNDAY AND INTO FAR SCTRL KS BY 00Z MONDAY.
A DEFINED FGEN BAND DEVELOPING ACROSS THE PANHANDLE INTO WESTERN
CHERRY COUNTY WILL WEAKEN SATURDAY NIGHT. THIS WILL OCCUR AS THE
COUPLED UPPER JET BECOMES REMOVE FROM THE REGION.
CHANCE POPS TO LIKELY POPS ACROSS THE FA SATURDAY NIGHT...ALONG
THE UPPER TROUGH AXIS. A WEDGE OF WARMER AIR IN PLACE EAST OF A
NORTH PLATTE THROUGH ONEILL LINE TO KEEP PRECIP TYPE AS RAIN OR A
RAIN/SNOW MIX WITH SNOW TO THE WEST. ON SUNDAY...SNOW TO END
ACROSS THE WESTERN ZONES AS A CHANCE FOR RAIN OR SNOW CONTINUES
ACROSS THE EAST. MODELS DIFFER ON POSITION OF THE UPPER LOW SUNDAY
INTO SUNDAY NIGHT. THE ECMWF IS SLOWER AND FURTHER SOUTH THAN THE
GFS WRT THE UPPER LOW. HIGHEST POPS FAVORED EAST OF NORTH PLATTE
THROUGH ONEILL LINE. CHANCES FOR SNOW AND RAIN OR SNOW THROUGH THE
DAY. ACCUMULATIONS WILL BE DEPENDENT ON AVAILABILITY OF COLDER AIR
AND EXACT TRACK OF THE SYSTEM. HIGHS MID TO UPPER 30S.
SNOW CHANCES END IN EASTERN AREAS SUNDAY NIGHT.
HAVE ISSUED A WINTER WEATHER ADVISORY FOR SNOW FOR THE EASTERN
PANHANDLE BEGINNING 12Z SATURDAY UNTIL 18Z SUNDAY WHERE SNOWFALL
AMOUNTS OF 3 TO 4 INCHES ARE FORECAST. FURTHER EAST...CONFIDENCE
REMAINS TOO LOW AND WILL HOLD OFF ON ISSUING FOR ADDL COUNTIES IN
THE WRN SANDHILLS.
THE NEXT SYSTEM WILL DROP THROUGH THE INTERMOUNTAIN WEST TOWARD
THE UT/CO/WY BORDER REGION BY MONDAY AFTERNOON. THIS SYSTEM IS
FORECAST TO DEVELOP A CLOSED LOW IN WESTERN NEBRASKA MONDAY NIGHT
LIFTING INTO EASTERN SOUTH DAKOTA TUESDAY. LOCATION AND TIMING OF
THE UPPER LOW DIFFER HOWEVER WRT THE GFS AND ECMWF. WITH A STRONG
TAP OF ARCTIC AIR...ANY PRECIPITATION WILL BE SNOW. LIKELY CHANCES
FOR SNOW ACCUMULATIONS TO BE ACROSS THE NCTRL NEBR. HIGHS TUESDAY
THROUGH THURSDAY IN THE MID TO UPPER 20S NORTH TO THE UPPER 20S
AND LOWER 30S SOUTH. LOWS DIPPING INTO THE SINGLE DIGITS AND
TEENS...ESPECIALLY IF SNOW COVER MATERIALIZES.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1134 AM CST FRI DEC 11 2015
A DIFFICULT AVIATION FORECAST IS IN STORE OVER THE NEXT 24 HOURS...AS
VARYING MODEL SOLUTIONS ARE LEADING TO LOW FORECASTER CONFIDENCE.
THIS LOW CONFIDENCE WILL BE EXPRESSED IN THE FOLLOWING BREAK DOWN
FOR EACH RESPECTIVE TERMINAL.
AT THE KVTN TERMINAL...17Z VISIBLE SATELLITE AND METAR
ANALYSIS DEPICTED A THICK DECK OF STRATUS AND IFR CONDITIONS OVER
MOST OF WESTERN SOUTH DAKOTA. THIS REGION OF STRATUS WAS MOVING
SLOWLY TO THE SOUTH AT APPROXIMATELY 5-10 KNOTS. THIS MOTION AND
SPEED WOULD BRING IFR CONDITIONS INTO THE KVTN TERMINAL BETWEEN 19Z-
20Z. WHILE THE 12Z RAP/NAM SOLUTIONS DEPICT THIS REGION OF STRATUS
ARRIVING AROUND THE 19-20Z HOUR...THE 12Z GFS MAINTAINS VFR
CONDITIONS OVER THE TERMINAL FOR THE NEXT 24 HOURS. BASED UPON
CURRENT VISIBLE SATELLITE AND METAR OBSERVATIONS...HAVE DECIDED TO
BASE THE NEXT 24 HOUR FORECAST AT THE KVTN TERMINAL OFF OF THE 12Z
RAP/NAM MODEL SOLUTIONS...AS THESE MODELS ARE CURRENTLY RESOLVING
THE STRATUS TO THE NORTH OF THE TERMINAL FAIRLY WELL.
FOR THE KLBF TERMINAL...SIGNIFICANT MODEL SOLUTIONS ALSO
EXISTS. WHILE THE 12Z NAM BRINGS IN IFR CEILINGS OVER THE NEXT
24 HOURS...THE 12Z GFS ONLY REDUCES CEILING TO AS LOW AS 5000FT
NEAR THE END OF THE FORECAST PERIOD. FURTHER COMPLICATING MATTERS...
THE 12Z RAP ONLY GOES OUT TO 09Z...AT WHICH TIME MVFR CONDITIONS
APPEAR POSSIBLE. FOR THIS REASON...HAVE DECIDED FOR THE SAKE OF
FORECAST CONTINUITY TO MAINTAIN A REDUCTION IN CEILINGS AROUND THE
09ZHOUR...HOWEVER...HAVE INCREASED CEILINGS SLIGHTLY FROM THE
PREVIOUS FORECAST DUE TO THE WIDE MODEL SPREAD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM SATURDAY TO 11 AM MST SUNDAY
FOR NEZ004-022-056.
&&
$$
SYNOPSIS...JACOBS
SHORT TERM...JACOBS
LONG TERM...ROBERG
AVIATION...MOLDAN
AREA FORECAST DISCUSSION
NWS NORTH PLATTE NE
1134 AM CST FRI DEC 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST FRI DEC 11 2015
A WEAK ARCTIC FRONTAL BOUNDARY ACROSS SD SHOULD BACK INTO NRN NEB
LATE THIS AFTN AND BE THE BASIS FOR STRATUS TONIGHT. THE FRONT
WILL BE DRAWN FARTHER SOUTH TONIGHT AS SFC LOW PRESSURE ACROSS
THE CNTL HIGH PLAINS THIS MORNING DROPS SOUTH INTO THE SRN
PLAINS.
THE ECM GUIDANCE WAS FAVORED FOR HIGHS IN THE 40S NORTH
TODAY...50S SOUTH. A BREAK IN THE CIRRUS ACROSS ERN COLO WILL BE
MOVING OVERHEAD SOMETIME TODAY SUPPORTING MILD TEMPERATURES. THE
UPPER LEVEL WINDS HAVE TAKEN AN EAST NORTHEAST TRAJECTORY WITH AN
APPROACHING UPPER LEVEL LONG WAVE TROF OVER THE WRN U.S. THIS
PRESENTS THE COLO ROCKIES AS THE SOURCE REGION FOR CIRRUS VS
WYOMING YESTERDAY.
THE ARCTIC FRONT WILL DRAPE SOUTH TONIGHT WITH WIDESPREAD CLOUD
COVER. LOWS FALL INTO THE 20S WITH HIGH HUMIDITY. SFC OBS BEHIND
THE COLD FRONT ARE IN THE UPPER 20S TO NEAR 30 BUT NEITHER THE
NAM NOR THE SREF MODELS INDICATE FOG GIVEN THE DEEPER MOISTURE
AND LACK OF RADIATIVE COOLING.
LASTLY...THE MODELS SHOW VARYING DEGREES OF 700-500MB
FRONTOGENESIS ACROSS NW NEB TONIGHT. THIS WOULD POOL MOISTURE AND
PERHAPS DEVELOP LIGHT SNOW BY SATURDAY MORNING ACROSS THE
PANHANDLE COUNTIES AND PERHAPS FAR SOUTHWEST NEB.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 AM CST FRI DEC 11 2015
UPPER LEVEL LOW WILL BE WEAKENING AS IT LIFTS NORTHEAST ACROSS
WESTERN NEBRASKA ON SATURDAY...WITH A NEW LOW DEVELOPING OVER THE
SOUTHERN PLAINS.
MODELS CONTINUE IN GOOD AGREEMENT WITH A FGEN BAND DEVELOPING
ACROSS THE SANDHILLS SATURDAY. GULF MOISTURE WILL BE SURGING
NORTH...HOWEVER INITIAL MOISTURE IS LIMITED IN THE MID/LOWER
LEVELS AND SATURATION WILL HAVE TO BE TOP DOWN. THUS EARLY IN THE
MORNING PRECIP TO BE LIGHT. PRECIP BECOMES HEAVIER FOR THE
AFTERNOON INTO THE EVENING HOURS. BUFKIT SOUNDINGS AND SFC TEMPS
BELOW 0C AND PRECIP TYPE ALL SNOW ACROSS THE WEST. ACCUMULATIONS
OF 1 TO 3 WITH LOCALLY A BAND OF 4 INCHES POSSIBLE BEFORE ENDING
SUNDAY MORN.
MORE OF A CONCERN IS THE EASTERN ZONES. A WARM BUT DRY LOWER LEVEL
LAYER TO CAUSE PRECIP TYPE ISSUES AND MAY BE TO MUCH FOR WEAK LIFT
TO OVERCOME. SAT MORN TEMPS AT OR BELOW FREEZING AND WITH THE WARM
LAYER SOME MELTING TO OCCUR. IF ANYTHING REACHES THE GROUND LIGHT
FREEZING RAIN OR SLEET IS POSSIBLE...ALTHOUGH IF THE SYSTEM SHIFTS
EAST SLIGHTLY EXPECT ALL SNOW. SFC TEMPS LOOK TO WARM ABOVE
FREEZING BY LATE MORNING SO A SWITCH TO RAIN OR SNOW IS
ANTICIPATED...ALBEIT LIGHT. THE BETTER LIFT IS ACROSS THE WESTERN
ZONES...BUT WITH THE SURGING MOISTURE LATER IN THE DAY...WILL
CONTINUE TO INCLUDE LOW POPS.
THE SECOND LOW OVER THE SOUTHERN PLAINS CONTINUE TO CAUSE PROBLEMS
WITH THE MODELS. THE 00Z RUNS HAVE DEVELOPED THE LOW A LITTLE
FURTHER TO THE NORTH...WITH THE EC CONTINUE TO BE THE STRONGEST
AND SLOWEST. THE TRACK OF THE UPPER LEVEL LOW REMAINS THE
SAME...TO THE NORTHEAST ACROSS THE MID MISS RVR VALLEY...WHICH IS
WELL EAST OF THE CWA. SOME WRAP AROUND SNOW IS POSSIBLE ACROSS THE
EASTERN ZONES...ALTHOUGH CONVECTION AHEAD OF THE SYSTEM COULD ROB
THE WRAP AROUND MOISTURE AND KEEP THE FORECAST AREA DRY FOR SUNDAY
AND SUNDAY NIGHT.
BREAK FOR MONDAY THEN THE NEXT SYSTEM ARRIVES MONDAY NIGHT. 00Z
MODELS ARE STRONGER WITH THIS SYSTEM COMPARED TO WHAT I WAS
LOOKING AT YESTERDAY. THIS SYSTEM WILL BE LIMITED WITH MOISTURE AS
GULF REMAINS CLOSED...THUS MOISTURE WILL BE CROSSING THE ROCKIES
AND TOP DOWN. TEMPS PLENTY COLD AND PRECIP WILL BE ALL SNOW. WILL
CONTINUE TO MONITOR AS ACCUMULATING SNOWS...HIGHEST CHANCE NEAR
THE S DAKOTA BORDER AT THIS TIME...WILL BE POSSIBLE.
SYSTEM EXITS BY WED MORNING WITH DRY AND MORE WINTER LIKE
TEMPS...LIKELY AT OR BELOW NORMAL...PENDING SNOW COVER...TEMPS MAY
NEED TO BE LOWERED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1134 AM CST FRI DEC 11 2015
A DIFFICULT AVIATION FORECAST IS IN STORE OVER THE NEXT 24 HOURS...AS
VARYING MODEL SOLUTIONS ARE LEADING TO LOW FORECASTER CONFIDENCE.
THIS LOW CONFIDENCE WILL BE EXPRESSED IN THE FOLLOWING BREAK DOWN
FOR EACH RESPECTIVE TERMINAL.
AT THE KVTN TERMINAL...17Z VISIBLE SATELLITE AND METAR
ANALYSIS DEPICTED A THICK DECK OF STRATUS AND IFR CONDITIONS OVER
MOST OF WESTERN SOUTH DAKOTA. THIS REGION OF STRATUS WAS MOVING
SLOWLY TO THE SOUTH AT APPROXIMATELY 5-10 KNOTS. THIS MOTION AND
SPEED WOULD BRING IFR CONDITIONS INTO THE KVTN TERMINAL BETWEEN 19Z-
20Z. WHILE THE 12Z RAP/NAM SOLUTIONS DEPICT THIS REGION OF STRATUS
ARRIVING AROUND THE 19-20Z HOUR...THE 12Z GFS MAINTAINS VFR
CONDITIONS OVER THE TERMINAL FOR THE NEXT 24 HOURS. BASED UPON
CURRENT VISIBLE SATELLITE AND METAR OBSERVATIONS...HAVE DECIDED TO
BASE THE NEXT 24 HOUR FORECAST AT THE KVTN TERMINAL OFF OF THE 12Z
RAP/NAM MODEL SOLUTIONS...AS THESE MODELS ARE CURRENTLY RESOLVING
THE STRATUS TO THE NORTH OF THE TERMINAL FAIRLY WELL.
FOR THE KLBF TERMINAL...SIGNIFICANT MODEL SOLUTIONS ALSO
EXISTS. WHILE THE 12Z NAM BRINGS IN IFR CEILINGS OVER THE NEXT
24 HOURS...THE 12Z GFS ONLY REDUCES CEILING TO AS LOW AS 5000FT
NEAR THE END OF THE FORECAST PERIOD. FURTHER COMPLICATING MATTERS...
THE 12Z RAP ONLY GOES OUT TO 09Z...AT WHICH TIME MVFR CONDITIONS
APPEAR POSSIBLE. FOR THIS REASON...HAVE DECIDED FOR THE SAKE OF
FORECAST CONTINUITY TO MAINTAIN A REDUCTION IN CEILINGS AROUND THE
09ZHOUR...HOWEVER...HAVE INCREASED CEILINGS SLIGHTLY FROM THE
PREVIOUS FORECAST DUE TO THE WIDE MODEL SPREAD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...CDC
LONG TERM...MASEK
AVIATION...MOLDAN
AREA FORECAST DISCUSSION
NWS BISMARCK ND
241 PM CST FRI DEC 11 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
LATEST RADAR LOOPS HAVE THE BACK EDGE OF THE PRECIPITATION
APPROACHING A NEW SALEM TO BEULAH LINE. EXPECT THE SNOW TO END
WEST OF THE MISSOURI RIVER BY 4 PM. RADAR LOOPS ALSO SHOW THE
SYSTEM MAY BE LIFTING NORTH A BIT FASTER NOW SO THE SNOW WILL
PROGRESSIVELY END THIS EVENING NORTH. EXPECT STORM TOTALS 2 TO 3
INCHES ACROSS CENTRAL NORTH DAKOTA AND 1 TO 2 INCHES NORTH.
ISOLATED 4 INCH AMOUNTS ARE POSSIBLE SOUTH CENTRAL SUCH AS
BISMARCK.
TONIGHT WITH LOW LEVEL MOISTURE IN PLACE WILL SEE CLOUDS ALL BUT
THE FAR SOUTHWEST WHERE A SOUTHWEST WIND COMPONENT AT H925-850 MAY
ERODE CLOUD DECK A BIT. OTHERWISE CLOUDY. BASED ON THE HRRR KEPT
SOME FOG IN AFTER MIDNIGHT THROUGH SATURDAY MORNING WEST CENTRAL
AND SOUTH.
ON SATURDAY WILL DONT SEE ANYTHING THAT WILL CLEAR CLOUDS SO
CLOUDY EXCEPT FOR THE FAR SOUTHWEST. HIGHS WILL BE LIMITED TO THE
LOWER 30S EXCEPT MID TO UPPER 30S SOUTHWEST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 241 PM CST FRI DEC 11 2015
SATURDAY NIGHT A LONGWAVE TROUGH IS WELL ESTABLISHED OVER THE
ROCKIES TO 4-CORNERS AREA. SHORTWAVE ENERGY MOVING NORTHEASTWARD
UPSTREAM OF THE TROUGH GLANCES THE JAMES RIVER VALLEY SATURDAY NIGHT
INTO SUNDAY MORNING. AREAS SOUTH OF JAMESTOWN COULD RECEIVE 1/2 INCH
TO AN INCH OF SNOW.
ATTENTION THEN TURNS TO THE NEXT STORM SYSTEM MOVING EAST ACROSS THE
ROCKIES. ON SUNDAY ANOTHER LONGWAVE TROUGH MOVES INTO THE WEST COAST
AND DIGS SOUTH TOWARDS CALIFORNIA. THE SYSTEM CONTINUES TO DEEPEN AS
IT MOVES ACROSS THE ROCKIES SUNDAY NIGHT AND MONDAY. UNCERTAINTIES
CONTINUE REGARDING PLACEMENT/TIMING OF THIS SYSTEM...BUT MODEL
CONSENSUS WOULD SUGGEST THE LEADING EDGE OF SHORTWAVE ENERGY AND
MOISTURE REACHING THE WESTERN DAKOTAS MONDAY AFTERNOON/EVENING. THE
MODELS DEVELOP THE STORM SYSTEM SUCH THAT THE TRACK OF THE MID-LEVEL
LOW MOVES FROM COLORADO ACROSS THE CENTRAL PLAINS TO EASTERN SOUTH
DAKOTA BY TUESDAY AFTERNOON AND INTO MINNESOTA TUESDAY NIGHT. THIS
LATEST RUN OF THE MODELS SUGGESTS SOUTHERN NORTH DAKOTA COULD
RECEIVE MODERATE SNOW AMOUNTS WITH LIGHT AMOUNTS IN THE NORTHWEST
AND NORTH CENTRAL...AND THIS OCCURRING OVER A PERIOD FROM MONDAY
AFTERNOON THROUGH TUESDAY NIGHT/WEDNESDAY MORNING. THIS TRACK WOULD
SUGGEST THAT AREAS SOUTH AND EAST OF OUR AREA WOULD RECEIVE THE BULK
OF PRECIPITATION WITH THIS SYSTEM.
ANOTHER SHORTWAVE DIVES SOUTHEAST OUT OF ALBERTA/SASKATCHEWAN
WEDNESDAY/THURSDAY...BUT WITH MUCH LESS MOISTURE AND ONLY SLIGHT
CHANCES OF LIGHT SNOW/FLURRIES.
A COOLING TREND THROUGH THE LONG TERM...WITH SEASONABLE TEMPERATURES
EXPECTED BY THE MIDDLE AND END OF NEXT WEEK...WITH HIGHS IN THE 20S
AND LOWS IN THE SINGLE DIGITS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 241 PM CST FRI DEC 11 2015
LOW STRATUS WILL BRING WIDESPREAD IFR/LOW IFR CONDITIONS ACROSS
THE REGION THROUGH FRIDAY NIGHT. SNOW WILL TAPER OFF FROM SOUTH
TO NORTH LATE FRIDAY AFTERNOON INTO THE EVENING HOURS. THERE WILL
BE SOME FOG TONIGHT DUE TO THE LOW LEVEL MOISTURE. POSSIBILITY
KDIK COULD BREAK OUT OF THE CLOUDS BUT TOO MUCH UNCERTAINTY SO WILL
KEEP IFR THERE FOR NOW UNTIL SUNRISE SATURDAY MORNING.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...WAA
LONG TERM...JV
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS MORRISTOWN TN
326 PM EST FRI DEC 11 2015
.SHORT TERM (TONIGHT THROUGH TOMORROW)...
YOU MAY HAVE TO LOOK AT THE CALENDAR TO REALIZE THAT IT IS MID-
DECEMBER. IN FACT...EXPECT MANY LOCATIONS WILL TOP OUT JUST A FEW
DEGREES BELOW RECORD HIGHS FOR TODAY. CURRENT WATER VAPOR IMAGERY
AND RAP UPPER AIR ANALYSIS INDICATES A RIDGE ACROSS THE NORTHERN
GULF COAST WITH A TROUGH MOVING ONTO THE WEST COAST. AT THE
SURFACE...HIGH PRESSURE CONTINUES ALONG THE SOUTHEASTERN COAST. A
STALLED FRONTAL BOUNDARY CURRENTLY STRETCHES ACROSS THE OHIO RIVER
VALLEY SOUTHWESTERN INTO EASTERN TEXAS. CLOSER TO HOME...DECENT LOW
LEVEL ISENTROPIC FLOW CONTINUES ACROSS THE AREA PRODUCING WIDESPREAD
CLOUD COVER WITH SOME OCCASIONAL SPRINKLES. LOW LEVEL SOUTHERLY
WINDS ARE ADVECTING IN WARM AIR AND MOISTURE WITH TEMPERATURES
CURRENTLY IN THE 60S TO LOW 70S AND DEWPOINTS IN THE 50S TO LOW
60S. FOR TONIGHT...EXPECT THE LOW LEVEL ASCENT WILL KEEP CONDITIONS
CLOUDY OVERNIGHT WITH OCCASIONAL DRIZZLE. MODELS INDICATE THAT
THERE COULD BE A FEW AREAS OF PATCHY FOG AND HAVE MENTIONED THIS IN
THE FORECAST BUT IT LOOKS AS THROUGH LOW LEVEL WINDS WILL BE
SUFFICIENT ENOUGH TO KEEP THE BOUNDARY LAYER MIXED. WITH THIS
SAID...DO NOT EXPECT ANY AREAS OF WIDESPREAD DENSE FOG TONIGHT.
WIDESPREAD CLOUD COVER AND LOW LEVEL SOUTHERLY WINDS WILL KEEP LOW
TEMPERATURES UP IN THE 50S TONIGHT.
THE MID TO UPPER LEVEL FLOW TAKES ON MORE OF A SOUTHWESTERLY
COMPONENT AS THE RIDGE AXIS MOVES THROUGH TOMORROW. THE STALLED
BOUNDARY WILL BEGIN TO PUSH TO THE NORTH. SATURDAY WILL START OFF
WITH CLOUDS AND PATCHY FOG BUT MODEL SOUNDINGS INDICATE A FEW PEAKS
OF SUNSHINE WILL BE POSSIBLE BY THE AFTERNOON. WITH THE HIGHER
HEIGHTS AND INCREASED INSOLATION...EXPECT TEMPERATURES WILL PUSH TO
NEAR RECORD VALUES. THE RECORD VALUE FOR CHATTANOOGA TOMORROW IS 72
DEGREES AND THINK THIS WILL BE THE RECORD THAT WILL MOST LIKELY BE
BROKEN.
.LONG TERM (SATURDAY NIGHT THROUGH FRIDAY)...
UNSETTLED WEATHER AHEAD AS TROUGH AFTER TROUGH MOVES THROUGH
DURING THE LONG TERM.
WELL ABOVE NORMAL TEMPERATURES CONTINUE SATURDAY NIGHT WITH LOWS
RANGING FROM THE UPPER 40S TO LOW TO MID 50S. SUNDAY THE ABOVE
NORMAL WARMTH CONTINUES AS A DEEP AND ROBUST TROUGH ACROSS THE
PLAINS MAINTAINS A STOUT SOUTHERLY FLOW OUT AHEAD OF THE
SYSTEM....RAISING TEMPS ACROSS THE EASTERN U.S. SUNDAY CONTINUES TO
LOOK DRY AT THIS POINT WITH CLOUDS SLOWLY INCREASING THROUGHOUT THE
DAY AND MORE SO TOWARD EVENING. BY SUNDAY AFTERNOON WINDS BECOME
QUITE BREEZY...ESPECIALLY ACROSS THE HIGHER ELEVATIONS...AS THE
PRESSURE GRADIENT BEGINS TO TIGHTEN AS THE DEEP WESTERN TROUGH
APPROACHES. WINDS LOOK TO BE THE STRONGEST SUNDAY NIGHT THROUGH
ABOUT 12Z MONDAY MORNING. A WIND ADVISORY ACROSS OUR EASTERN
MOUNTAINS WILL LIKELY BE NEEDED DURING THIS PERIOD. AS OF NOW...IT
LOOKS LIKE THE HIGHEST PEAKS WILL SEE SUSTAINED WINDS IN THE 30S
WITH GUSTS UP TO 55 MPH DUE TO THE STRONG 850MB JET PUSHING THROUGH
WITH THIS SYSTEM. ALSO...IF WINDS BACK A TAD MORE AT THE 850MB LEVEL
WE COULD POSSIBLY HAVE A BRIEF PERIOD OF MOUNTAIN WAVES. THE MAIN
LINE OF SHOWERS MOVE IN AFTER MIDNIGHT AND MOVE OUT BY LATE MORNING
TO EARLY AFTERNOON MONDAY. THERE COULD ALSO BE A RUMBLE OF THUNDER
AS THE LINE OF SHOWERS MOVE THROUGH AS THERE IS VERY WEAK ELEVATED
INSTABILITY PRESENT IN THE 12Z NAM AND GFS SOUNDINGS. OUR FAR
WESTERN AREAS MAY SEE THE SUN RETURN BY MONDAY AFTERNOON WITH
CONDITIONS CLEARING FROM WEST TO EAST AS THIS SYSTEM PULLS NE OUT OF
THE AREA.
BRIEF ZONAL FLOW RETURNS ON TUESDAY GIVING US A DRY DAY WITH MOSTLY
SUNNY SKIES AND TEMPS IN THE UPPER 50S TO LOW 60S. ANOTHER TROUGH
APPROACHES WEDNESDAY/WEDNESDAY NIGHT AND GIVE US ANOTHER SHOT AT
SHOWERS. THEN ANOTHER TROUGH MOVES IN LATE THURSDAY INTO
FRIDAY...GIVING US YET ANOTHER SHOT AT SHOWERS. OVERALL...A MILD AND
UNSETTLED LONG TERM IN STORE.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 58 74 55 71 / 10 10 10 10
KNOXVILLE MCGHEE TYSON AIRPORT, TN 56 73 51 71 / 10 10 10 10
OAK RIDGE, TN 58 72 51 71 / 10 10 10 10
TRI CITIES AIRPORT, TN 49 70 46 71 / 10 10 10 10
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...NONE.
VA...NONE.
&&
$$
MA/SR
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
337 PM CST FRI DEC 11 2015
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 337 PM CST FRI DEC 11 2015
MAIN FORECAST CONCERNS FOR TONIGHT ARE ON DRIZZLE AND FOG POTENTIAL.
LOW PRESSURE...CURRENTLY MOVING ACROSS EASTERN NEBRASKA/WESTERN
IOWA...WILL CONTINUE TO PUSH EASTWARD AND WEAKEN TONIGHT. THIS WILL
LIFT A WEAK WARM FRONT INTO THE REGION WITH WIDESPREAD STRATUS/LOW
CLOUDS MOVING IN. THERE COULD EVEN BE SOME LIGHT DRIZZLE AT TIMES
MAINLY ACROSS PORTIONS OF NORTHEAST IOWA INTO FAR SOUTHWEST
WISCONSIN. SOME FOG IS ALSO POSSIBLE TONIGHT BUT IT SHOULD MAINLY BE
CONFINED TO HIGHER TERRAIN LOCATIONS SUCH AS RIDGES AND BLUFF TOPS.
THERE IS THE POTENTIAL FOR SOME LOCALLY DENSE FOG ACROSS PORTIONS
OF NORTHEAST IOWA AND EXTREME SOUTHWEST WISCONSIN BUT THE BULK OF
THIS SHOULD REMAIN SOUTH OF THE FORECAST AREA. WE SHOULD THEN SEE
A BREAK IN THE DRIZZLE ON SATURDAY WITH MUCH OF THE DAY EXPECTED
TO BE OVERCAST AND DRY. A VIGOROUS TROUGH THEN DIGS INTO THE
SOUTHWEST CONUS TONIGHT AND PUSHES INTO THE PLAINS LATE SATURDAY
AFTERNOON INTO SATURDAY NIGHT SETTING THE STAGE FOR WIDESPREAD
RAIN ACROSS THE REGION AND UNSEASONABLY WARM TEMPERATURES.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 337 PM CST FRI DEC 11 2015
A VERY MOIST AND WARM AIRMASS FOR THIS TIME OF YEAR MOVES IN
SATURDAY NIGHT INTO SUNDAY WITH PRECIPITABLE WATER VALUES OF 1 TO
1.5 INCHES PRODUCING STANDARDIZED ANOMALIES OF PLUS 4 TO PLUS 5.
TEMPERATURES ARE EQUALLY AS IMPRESSIVE ON SUNDAY WITH HIGHS
EXPECTED TO SOAR INTO 50S TO POSSIBLY THE UPPER 50S AT A FEW
LOCATIONS...PLACING US IN RECORD TERRITORY AT SOME LOCATIONS. THE
RAINS SET IN FOR SATURDAY NIGHT BUT THE GREATEST SURGE OF MOISTURE
LOOKS TO OCCUR LATE SATURDAY NIGHT INTO SUNDAY MORNING. A FEW
THUNDERSTORMS MAY ALSO MIX IN WITH THE RAIN DURING THIS TIMEFRAME.
THE RAIN WILL CONTINUE THROUGH THE DAY ON SUNDAY AND INTO SUNDAY
NIGHT AS THE UPPER LOW LIFTS NORTHEAST OUT OF THE PLAINS AND
PUSHES INTO THE UPPER MISSISSIPPI RIVER VALLEY. NORMALLY WITH
SEMI-FROZEN GROUND WE WOULD BE LOOKING AT FLOODING CONCERNS WITH
THIS SYSTEM. HOWEVER...UNFROZEN SOILS WILL HELP TO MITIGATE RUNOFF
AND GIVEN PROLONGED NATURE OF THE RAINFALL...RIVER RISES WILL BE
THE MAIN CONCERN. MANY RIVERS ARE RUNNING HIGH FOR THIS TIME OF
YEAR SO WE WILL HAVE TO KEEP AN EYE ON WHERE THE HEAVIEST RAINFALL
OCCURS. CURRENT THINKING IS THAT WIDESPREAD RAINFALL OF 1.5 TO 2.4
INCHES WOULD FALL ACROSS THE FORECAST AREA FROM SATURDAY NIGHT
THROUGH MONDAY.
THE UPPER LOW MOVES THROUGH DURING THE DAY ON MONDAY AND STARTS TO
WRAP COLDER AIR INTO THE REGION BY MONDAY AFTERNOON INTO MONDAY
NIGHT. WE COULD SEE A SWITCH OVER TO SNOW IF THE COLD AIR ARRIVES
SOON ENOUGH....WITH LIGHT ACCUMULATIONS POSSIBLE. THE LOW WILL
THEN EXIT MONDAY NIGHT. THE NEXT TROUGH WILL BE QUICK ON THE HEELS
OF THE FIRST AND LOOKS TO BRING MUCH COOLER...MORE SEASONABLE
TEMPERATURES TO THE REGION ALONG WITH SOME CHANCES FOR LIGHT SNOW.
THE BULK OF THE RAIN/SNOW LOOKS TO OCCUR NORTHWEST OF THE FORECAST
AREA ACROSS ACROSS THE DAKOTAS AND CENTRAL INTO NORTHERN
MINNESOTA. HOWEVER...IF THE STORM TRACK SHIFTS A LITTLE FURTHER
SOUTH NORTHWEST SECTIONS OF THE FORECAST AREAS COULD GET IN ON
SOME SNOW ACCUMULATIONS TUESDAY NIGHT INTO WEDNESDAY. HIGHS WILL
FALL BACK INTO THE 30S AND 40S ON TUESDAY...THEN COOL INTO THE 20S
AND 30S THURSDAY INTO FRIDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1105 AM CST FRI DEC 11 2015
THE LOW CLOUDS WITH IFR/MVFR CEILINGS HAVE BEEN SLOW TO LIFT OUT
OF THE AREA THIS MORNING. THE 11.12Z NAM AND 11.15Z RAP STILL
SUGGEST THE AREA OF MOISTURE WITH THESE CLOUDS WILL GRADUALLY GET
PUSHED NORTH THROUGH THE AFTERNOON AS THE FLOW TURNS MORE TO THE
SOUTH AHEAD OF THE AREA OF LOW PRESSURE OVER KANSAS. WILL GO WITH
THIS TREND OF THE CEILINGS COMING UP TO VFR EARLY THIS AFTERNOON
FOR BOTH SITES. ANOTHER AREA OF HIGH LOW LEVEL MOISTURE AND IFR
CEILINGS IS IN PLACE OVER SOUTHERN ILLINOIS AND MISSOURI. THIS
MOISTURE IS EXPECTED TO GET LIFTED NORTH AND INTO THE AREA TONIGHT
BRINGING MORE IFR AND MVFR CEILINGS TO THE REGION. THIS TREND WAS
SHOWN IN THE PREVIOUS FORECASTS AND WILL CONTINUE THIS BUT PUSH
THE TIMING BACK AS BOTH THE RAP AND NAM SHOW THIS BEING A LITTLE
SLOWER TO ARRIVE. SOME CONCERN WHETHER THERE WILL BE ANY DRIZZLE
WITH THESE LOWER CLOUDS AND HAVE LEFT THIS OUT FOR NOW AS THE BEST
LIFT THROUGH THE SATURATED LAYER LOOKS TO OCCUR AS THE MOISTURE
MOVES IN AND BY THE TIME THE SATURATED LAYER IS DEEP ENOUGH TO
SUPPORT DRIZZLE...THE LIFT BECOMES VERY WEAK.
&&
.HYDROLOGY...SATURDAY NIGHT THROUGH MONDAY
ISSUED AT 337 PM CST FRI DEC 11 2015
TOTAL RAINFALL SATURDAY NIGHT THROUGH SUNDAY WILL RANGE FROM 1.5 TO
2.4 INCHES. RIVERS ACROSS THE REGION ARE RUNNING IN THE 90TH
PERCENTILE RANGE FOR THIS TIME OF YEAR. ALTHOUGH NO FLOODING IS
EXPECTED AT THIS TIME...PLAN ON SIGNIFICANT WITHIN BANK RISES.
THOSE WITH INTERESTS ALONG AREA RIVERWAYS ARE ENCOURAGED TO STAY
TUNED TO LATEST FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...WETENKAMP
LONG TERM...WETENKAMP
AVIATION...04
HYDROLOGY...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1105 AM CST FRI DEC 11 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 345 AM CST FRI DEC 11 2015
CHALLENGES THROUGH TONIGHT INCLUDE CLOUD TRENDS/TEMPERATURES...AND
DRIZZLE POTENTIAL THIS EVENING INTO THE OVERNIGHT. WILL FOLLOW A
BLEND BETWEEN THE 11.00Z NAM/ECMWF/GEM THROUGH 12Z SATURDAY WITH
THE MUCH DRIER GFS BEING AN OUTLIER IN THE SHORT-TERM.
FOR TODAY...A SURFACE TROUGH WILL DEVELOP IN THE LEE OF THE
SOUTHERN ROCKIES AND INTO THE CENTRAL PLAINS IN RESPONSE TO A
DEEPENING TROUGH ACROSS THE WESTERN CONUS. RAP RELATIVE HUMIDITY
SUGGESTS AREAS ALONG AND NORTH OF THE I-90 CORRIDOR WILL REMAIN
MOSTLY CLOUDY FOR A GOOD PORTION OF THE DAY WITH A MIX OF SUN AND
HIGHER CLOUDS FURTHER SOUTH. THESE CLOUDS...COMBINED WITH A COOLER
LOW-LEVEL THERMAL PROFILE IN THE WAKE OF YESTERDAY/S STORM SYSTEM
WILL RESULT IN TEMPERATURES 5 TO 10 DEGREES BELOW YESTERDAY/S
READINGS. AFTERNOON HIGHS WILL RANGE FROM AROUND 40 DEGREES ACROSS
NORTH-CENTRAL WI TO NEAR 50 DEGREES ACROSS PORTIONS OF NORTHEAST
IA INTO ADJACENT AREAS OF SOUTHWEST WI.
SURFACE TO 850 HPA LAYER SLOWLY SATURATES THIS EVENING/OVERNIGHT
AND WITH MODEST LIFT ALONG THE 285 TO 290 K ISENTROPIC SURFACE...
EXPECT PATCHY TO AREAS OF DRIZZLE MAINLY ALONG AND NORTHEAST OF
THE MS RIVER VALLEY. SURFACE TEMPERATURES WILL REMAIN ABOVE
FREEZING WITH LOWS MAINLY IN THE MID TO UPPER 30S...SO IMPACT WILL
BE NEGLIGIBLE.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 345 AM CST FRI DEC 11 2015
WILL KEEP 20 POPS FOR ANY LINGERING DRIZZLE ON SATURDAY...BUT
MOST OF THE DAY SHOULD BE DRY AS PRIMARY ISENTROPIC LIFT MOVES
NORTH OF THE FORECAST AREA. SKIES WILL BE MOSTLY CLOUDY WITH
TEMPERATURES SIMILAR TO TODAY...PERHAPS A DEGREE OR TWO WARMER.
PRIMARY FOCUS WILL BE SATURDAY NIGHT THROUGH MONDAY AS AN
IMPRESSIVE STORM SYSTEM MOVES ACROSS THE UPPER MIDWEST. A STRONG
WARM FRONT WILL SURGE NORTHWARD SATURDAY NIGHT...USHERING IN VERY
WARM AND MOIST CONDITIONS FOR MID-DECEMBER. PWATS LOOK TO INCREASE
ABOVE ONE INCH SATURDAY NIGHT INTO SUNDAY...WHICH IS 3 TO 4
STANDARD DEVIATIONS ABOVE CLIMATOLOGY ACCORDING TO THE 11.00Z
NAEFS. SURFACE FRONT STALLS OUT ON SUNDAY...BISECTING THE FORECAST
AREA FROM SOUTHWEST TO NORTHEAST AND PROVIDES A FOCUS FOR
SIGNIFICANT LIFT. AS A RESULT...EXPECT PERIODS OF MODERATE TO
HEAVY RAIN SATURDAY NIGHT THROUGH SUNDAY AND SUNDAY NIGHT.
ISOLATED THUNDERSTORMS ARE ALSO POSSIBLE MAINLY ACROSS NORTHEAST
IA INTO SOUTHWEST MN AS 0 TO 6 KM MUCAPE RISES TO BETWEEN 100 AND
300 J/KG. TOTAL RAINFALL WILL RANGE FROM 1.5 TO 2.25 INCHES. SEE
HYDROLOGY SECTION BELOW FOR POSSIBLE IMPACTS ON AREA RIVERS AND
STREAMS.
DESPITE THE CALENDAR...PRECIP WILL FALL AS ALL RAIN THROUGH
SUNDAY NIGHT AS 925 HPA TEMPERATURES CLIMB TO BETWEEN +11 AND +13
CELSIUS BY 18Z SUNDAY. EVEN WITH CLOUD COVER AND RAIN...THIS
SHOULD RESULT IN SUNDAY AFTERNOON HIGHS FROM THE MID 40S ACROSS
THE NORTHWEST TO NEAR 60 DEGREES IN THE SOUTHEAST.
PRIMARY DISAGREEMENT BETWEEN THE 11.00Z GLOBAL MODEL SUITE AT
THIS TIME IS THE SPEED IN WHICH THIS SYSTEM MOVES OUT OF THE
REGION ON MONDAY. THE GFS/NAM/GEM PLACE THE SURFACE LOW OVER LAKE
SUPERIOR BY 18Z MONDAY...WHEREAS THE ECMWF IS MUCH SLOWER WITH ITS
LOW OVER SOUTHEAST MN. THE FORMER CONSENSUS SOLUTION WOULD RESULT
IN A MUCH COLDER AIR MASS ALOFT MOVING INTO THE REGION MORE
QUICKLY...THUS INCREASING THE CHANCE FOR LINGERING PRECIP TO TURN
INTO A WINTRY MIX. AT THIS TIME...THINK VAST MAJORITY OF PRECIP
WILL OUTRUN THE COLDER AIR WITH MINIMAL IMPACT TO THE REGION.
HOWEVER...COULD STILL SEE SOME NON-ACCUMULATING SNOW FLAKES ON
MONDAY WITH HIGHS FROM THE MID 30S TO MID 40S.
ANOTHER DEEP TROUGH MOVES INTO THE NATION/S MID-SECTION BY LATE
TUESDAY/WEDNESDAY...BUT GFS/ECMWF BOTH SHOW THE MAJORITY OF
PRECIP MOVING ACROSS THE DAKOTAS INTO NORTHERN MN...KEEPING THE
FORECAST AREA WITHIN THE SYSTEM/S DRY SLOT. FOR NOW...WILL
MAINTAIN THE SUPERBLEND CHANCE POPS GIVEN THE INHERENT
UNCERTAINTIES WITH A SYSTEM ON DAYS 5-7. OF GREATER CERTAINTY FOR
NEXT WEEK...TEMPERATURES WILL FALL EACH DAY...NEARING SOMETHING
CLOSER TO MID-DECEMBER NORMALS. HIGHS WEDNESDAY/THURSDAY LOOK TO
TOP OUT IN THE UPPER 20S TO MID 30S...A SHOCK TO THE SYSTEM GIVEN
THE ABNORMAL WARMTH OF THE PAST FEW WEEKS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1105 AM CST FRI DEC 11 2015
THE LOW CLOUDS WITH IFR/MVFR CEILINGS HAVE BEEN SLOW TO LIFT OUT
OF THE AREA THIS MORNING. THE 11.12Z NAM AND 11.15Z RAP STILL
SUGGEST THE AREA OF MOISTURE WITH THESE CLOUDS WILL GRADUALLY GET
PUSHED NORTH THROUGH THE AFTERNOON AS THE FLOW TURNS MORE TO THE
SOUTH AHEAD OF THE AREA OF LOW PRESSURE OVER KANSAS. WILL GO WITH
THIS TREND OF THE CEILINGS COMING UP TO VFR EARLY THIS AFTERNOON
FOR BOTH SITES. ANOTHER AREA OF HIGH LOW LEVEL MOISTURE AND IFR
CEILINGS IS IN PLACE OVER SOUTHERN ILLINOIS AND MISSOURI. THIS
MOISTURE IS EXPECTED TO GET LIFTED NORTH AND INTO THE AREA TONIGHT
BRINGING MORE IFR AND MVFR CEILINGS TO THE REGION. THIS TREND WAS
SHOWN IN THE PREVIOUS FORECASTS AND WILL CONTINUE THIS BUT PUSH
THE TIMING BACK AS BOTH THE RAP AND NAM SHOW THIS BEING A LITTLE
SLOWER TO ARRIVE. SOME CONCERN WHETHER THERE WILL BE ANY DRIZZLE
WITH THESE LOWER CLOUDS AND HAVE LEFT THIS OUT FOR NOW AS THE BEST
LIFT THROUGH THE SATURATED LAYER LOOKS TO OCCUR AS THE MOISTURE
MOVES IN AND BY THE TIME THE SATURATED LAYER IS DEEP ENOUGH TO
SUPPORT DRIZZLE...THE LIFT BECOMES VERY WEAK.
&&
.HYDROLOGY...
ISSUED AT 345 AM CST FRI DEC 11 2015
TOTAL RAINFALL SATURDAY NIGHT THROUGH SUNDAY WILL RANGE FROM 1.5
TO 2.25 INCHES. RIVERS ACROSS THE REGION ARE RUNNING IN THE 90TH
PERCENTILE RANGE FOR THIS TIME OF YEAR. ALTHOUGH NO FLOODING IS
EXPECTED AT THIS TIME...PLAN ON SIGNIFICANT WITHIN BANK RISES.
THOSE WITH INTERESTS ALONG AREA RIVERWAYS ARE ENCOURAGED TO STAY
TUNED TO LATEST FORECASTS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...ROGERS
LONG TERM....ROGERS
AVIATION...04
HYDROLOGY....DAS/ROGERS