Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/08/13
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1251 PM EST FRI DEC 6 2013
.SYNOPSIS...
LOW PRESSURE MOVES EAST ALONG A STALLED FRONT TO OUR SOUTH
OVERNIGHT. COLD HIGH PRESSURE BUILDING IN FOR THE WEEKEND. LOW
PRESSURE APPROACHES SUNDAY NIGHT AND IMPACTS THE NORTHEAST
THROUGH THE FIRST HALF OF NEXT WEEK WITH HIGH PRESSURE BUILDING IN
FOR THE SECOND HALF.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE GOES WATER VAPOR IMAGERY TELLS THE PICTURE WITH A RIVER OF
MOISTURE FROM THE CENTRAL PACIFIC TO NEWFOUNDLAND.
SFC COLD FRONT SEEN ON RADAR AND IN THE OBS APPROACHING OCEAN CITY
AS OF 1630Z. LATEST HRRR AND RADAR CONTINUES TO SUPPORTS LIGHT RA
ENDING FOR A BRIEF PERIOD EARLY THIS AFTERNOON FROM WEST TO EAST
THEN REDEVELOPING THIS AFTERNOON AS WAVE OF WEAK LOW PRESSURE
RIDE ALONG THE FRONT.
TEMPS STEADY UNTIL 3-4 PM...THEN START A SLOW FALL IN THE COLD
ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
HAVE ISSUED A WINTER WX ADVISORY FOR ORANGE AND PUTNAM COUNTIES
FOR TONIGHT BASED ON LASTED DATA AND COLLABORATION WITH
SURROUNDING NWS OFFICES.
COLD "NOSE" IN LOW LEVELS AROUND 2-4K FT AGL LAYER WITH TEMPS OF
-3 TO -5 C BY 00Z AT KSWF SEEN IN 12Z NAM SOUNDING. THIS CLEARLY
SUPPORTS SLEET. IN FACT, MODERATE TO OCCASIONALLY HEAVY SLEET.
SLEET ACCUMULATION IN ORANGE MY BE AN INCH OR MORE. ITS TOWARDS 10
TO 11 PM THAT THE COLUMN ALOFT (5-10K FT AGL) COOLS ENOUGH TO
SUPPORT SNOW. SNOW AMOUNTS ON TOP THE SLEET WILL DEPEND ON THE
PRECISE TIMING OF THIS COOLING ALOFT. SEE THE POTENTIAL, BASED ON
SREF PLUMES, FOR SEVERAL INCHES. THINKING THE HIGH END WOULD BE 5
WITH MORE LIKELY THE 1 TO 3 RANGE. HAVE ISSUED THE WSW BASED ON
THE EXPECTED SIGNIFICANT AMOUNT OF SLEET AT THE START EVEN THROUGH
COUNTY AVERAGES ARE BELOW THE 3 INCH CRITERIA. IN ADDITION...TEMPS
BELOW FREEZING IN THE ADVISORY AREA WILL MAKE FOR A SIGNIFICANT
IMPACT ON TRAVEL.
WITH THE LOSS OF COLD CLOUD SEEDER/FEEDER NUCLEATION...PCPN IN
THE ADVISORY AREA MY END AS LIGHT FREEZING DRIZZLE.
THE I-84 CORRIDOR IN CT SHOULD ALSO GET ACCUMULATIONS. THUS THESE
AREAS ARE IN THE HWO PRODUCT AND WILL ISSUE AN SPECIAL WEATHER
STATEMENT ONCE RULES ALLOW.
ALONG THE COAST...SEE ALL RAIN. THINK THE POTENTIAL FOR AN SLEET
IS TOO LOW TO MENTION.
EXPECT PCPN TO END QUICKLY SATURDAY AM WITH CLOUDS GIVING WAY TO
AFTERNOON SUNSHINE.
TEMPS RISE TO THE UPPER 30S TO LOWER 40S SATURDAY (GFS MOS
USED)...WHICH IS SLIGHTLY BELOW NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE KEEPS THE REGION DRY SATURDAY NIGHT AND MOST OF THE
DAYTIME HOURS OF SUNDAY WITH BELOW-NORMAL TEMPS.
FOR LATE-DAY SUNDAY THROUGH MONDAY NIGHT...MODELS IN GOOD AGREEMENT
THAT LOW PRESSURE SHIFTS IN FROM THE SOUTH AND WEST...BRINGING
PCPN MAINLY SUNDAY NIGHT THROUGH MONDAY AFTERNOON. THERE IS A
CHANCE HOWEVER THAT THE SOUTHERNMOST PORTIONS OF THE FORECAST AREA
SEE SOME LIGHT SNOW OR FLURRIES DEVELOP RIGHT BEFORE SUNSET ON
SUNDAY. PCPN EVENTUALLY BECOMES LIKELY FOR THE CITY AND OTHER
SOUTHERN SECTIONS BY MIDNIGHT...THEN LIKELY FARTHER NORTH AND EAST
AROUND OR SHORTLY AFTER MIDNIGHT.
FORECAST BUFKIT SOUNDINGS SHOW AN ELEVATED WARM LAYER
DEVELOPING...RESULTING IN MIXED PCPN TYPES. COMPLICATING THE
PCPN TYPE FORECAST FURTHER WILL BE COOLING OF BOUNDARY LAYER AND
SURFACE TEMPS DUE TO WET-BULBING...FOLLOWED BY ONSHORE WINDS THAT
WOULD PUSH TEMPS BACK UP OVERNIGHT SUNDAY NIGHT.
DUE TO THE PCPN TYPE COMPLICATIONS...THE FORECAST WILL PROBABLY
NEED TO BE CHANGED AS THE EVENT DRAWS CLOSER. BUT AT THIS POINT
FOR THE CITY AND COASTAL SECTIONS IT LOOKS LIKE SNOW AT THE ONSET
AS WET-BULBING WOULD PROBABLY OFFSET ANY BOUNDARY LAYER WARMTH
THAT WOULD OTHERWISE SUPPORT RAINFALL. MIXED RAIN/SLEET/SNOW WOULD
THEN FOLLOW HEADING CLOSER TOWARDS MIDNIGHT. A CHANGEOVER TO RAIN
WOULD THEN LIKELY OCCUR DURING THE LATE NIGHT HOURS. FOR INLAND
SPOTS...PRIMARILY SNOW FOR A DECENT PORTION OF THE NIGHT FOLLOWED
BY A WINTRY MIX LATE. A CHANGEOVER TO RAIN PROBABLY OCCURS BY LATE
MORNING FOR MOST INLAND SPOTS. LIGHT SNOW/SLEET ACCUMULATIONS
WOULD BE POSSIBLE...BUT PRIMARILY INLAND. WHATEVER LITTLE
ACCUMULATION THE CITY/COAST COULD MANAGE WOULD BE WASHED AWAY
FAIRLY QUICKLY BY RAIN AND WARMING TEMPS.
THE SYSTEM HEADS OUT TO SEA ON MONDAY NIGHT WITH A CHANCE OF
LINGERING PCPN THROUGH TUESDAY MORNING AS MODELS HINT AT A WEAK
WAVE OF LOW PRESSURE FORMING ALONG A FRONTAL BOUNDARY TO THE SOUTH
AND KEEPING PCPN CLOSE TO US. SHOULD THERE STILL BE PCPN DURING
THIS PERIOD...IT WOULD LIKELY BE RAIN CHANGING OVER TO A WINTRY
MIX...WITH THE CHANGE FIRST OCCURRING INLAND MONDAY NIGHT...THEN FOR
COASTAL SECTIONS LATE AT NIGHT INTO TUESDAY MORNING.
HIGH PRESSURE BUILDS IN FOR TUESDAY NIGHT THROUGH THURSDAY WITH DRY
WEATHER...BUT WITH COLDER THAN NORMAL TEMPERATURES.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
MVFR WITH LCL IFR CONDS THIS AFTERNOON IN -RA/BR.
LOW PRES APPROACHES TONIGHT. ALL RAIN AT THE TERMINALS THROUGH
10Z...POSSIBLY MIXING WITH SLEET AS PRECIP WINDS DOWN AROUND 10Z.
FOR KSWF...RAIN CHANGES TO SLEET THIS EVENING...AND THEN
SNOW/SLEET ON TAP FOR MUCH OF TONIGHT BEFORE PRECIP TAPERS OFF AS
SNOW LATE. IFR/LIFR CONDS.
N WINDS AROUND 10 KT...BACKING TO THE NW SATURDAY MORNING. VFR BY
LATE SATURDAY MORNING.
...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)
KEWR FCSTER COMMENTS: MARGINAL CONDS...LOWERING TO IFR BY 23Z.
KJFK FCSTER COMMENTS: MARGINAL CONDS...LOWERING TO IFR BY 23Z.
KLGA FCSTER COMMENTS: MARGINAL CONDS...LOWERING TO IFR BY 23Z.
KTEB FCSTER COMMENTS: IFR/MVFR CONDS...BCMG IFR BY 23Z.
KHPN FCSTER COMMENTS: IFR/MVFR CONDS...BCMG IFR BY 23Z.
KISP FCSTER COMMENTS: IFR/MVFR CONDS...BCMG IFR BY 00Z.
.OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY...
.SAT AFTERNOON...VFR. NW WINDS 10-20 KT.
.SUNDAY...VFR. LIGHT WINDS.
.SUNDAY NIGHT...IFR. SNOW...THEN SNOW/SLEET/RAIN NEAR THE COAST
AND SNOW/SLEET ACROSS INTERIOR.
.MONDAY...IFR. RAIN. WINTRY MIX ACROSS INTERIOR EARLY...THEN RAIN.
SE WINDS 10-15 KT...BCMG NW LATE.
.MONDAY NIGHT...WINTRY MIX POSSIBLE. WEST WINDS 10 KT OR LESS.
.TUESDAY...VFR. WEST WINDS 10 KT OR LESS.
.WEDNESDAY...VFR. W WIND 15-25 KT.
&&
.MARINE...
COLD FRONT NOW WELL SOUTH OF THE OCEAN COASTAL WATERS.
OVERALL...WINDS BELOW SCA CRITERIA...BUT OCEAN WAVES WILL TAKE A
WHILE TO SUBSIDE. OVERNIGHT...WINDS INCREASE FOR A SHORT TIME
LATE AS A WAVE OF LOW PRESSURE PASSES JUST TO THE SOUTH. WAVES ON
THE OCEAN SHOULD SUBSIDE TO JUST BELOW SCA LEVELS.
SCA CONDITIONS ARE POSSIBLE SATURDAY NIGHT OVER THE OCEAN
WATERS...OTHERWISE TRANQUIL. WINDS AND SEAS INCREASE WITH AN
APPROACHING STORM SUNDAY NIGHT AND MONDAY. SCA CONDITIONS EXPECTED
WITH THIS STORM.
&&
.HYDROLOGY...
PRECIPITATION THROUGH SATURDAY IS EXPECTED TO TOTAL NEAR AN
INCH. NO HYDROLOGIC ISSUES ANTICIPATED.
A STORM SYSTEM COULD BRING A LIQUID EQUIVALENT PRECIPITATION AMOUNT
OF A HALF INCH TO AN INCH FROM LATE SUNDAY AFTERNOON THROUGH MONDAY
NIGHT.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD
EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS
WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL
WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES
TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
SATURDAY FOR NYZ067-068.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE/PW
LONG TERM...JC
AVIATION...MPS
MARINE...JC/PW
HYDROLOGY...JC/PW
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1200 PM EST FRI DEC 6 2013
.SYNOPSIS...
LOW PRESSURE MOVES EAST ALONG A STALLED FRONT TO OUR SOUTH
OVERNIGHT. COLD HIGH PRESSURE BUILDING IN FOR THE WEEKEND. LOW
PRESSURE APPROACHES SUNDAY NIGHT AND IMPACTS THE NORTHEAST
THROUGH THE FIRST HALF OF NEXT WEEK WITH HIGH PRESSURE BUILDING IN
FOR THE SECOND HALF.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE GOES WATER VAPOR IMAGERY TELLS THE PICTURE WITH A RIVER OF
MOISTURE FROM THE CENTRAL PACIFIC TO NEWFOUNDLAND.
SFC COLD FRONT SEEN ON RADAR AND IN THE OBS APPROACHING OCEAN CITY
AS OF 1630Z. LATEST HRRR AND RADAR CONTINUES TO SUPPORTS LIGHT RA
ENDING FOR A BRIEF PERIOD EARLY THIS AFTERNOON FROM WEST TO EAST
THEN REDEVELOPING THIS AFTERNOON AS WAVE OF WEAK LOW PRESSURE
RIDE ALONG THE FRONT.
TEMPS STEADY UNTIL 3-4 PM...THEN START A SLOW FALL IN THE COLD
ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
HAVE ISSUED A WINTER WX ADVISORY FOR ORANGE AND PUTNAM COUNTIES
FOR TONIGHT BASED ON LASTED DATA AND COLLABORATION WITH
SURROUNDING NWS OFFICES.
COLD "NOSE" IN LOW LEVELS AROUND 2-4K FT AGL LAYER WITH TEMPS OF
-3 TO -5 C BY 00Z AT KSWF SEEN IN 12Z NAM SOUNDING. THIS CLEARLY
SUPPORTS SLEET. IN FACT, MODERATE TO OCCASIONALLY HEAVY SLEET.
SLEET ACCUMULATION IN ORANGE MY BE AN INCH OR MORE. ITS TOWARDS 10
TO 11 PM THAT THE COLUMN ALOFT (5-10K FT AGL) COOLS ENOUGH TO
SUPPORT SNOW. SNOW AMOUNTS ON TOP THE SLEET WILL DEPEND ON THE
PRECISE TIMING OF THIS COOLING ALOFT. SEE THE POTENTIAL, BASED ON
SREF PLUMES, FOR SEVERAL INCHES. THINKING THE HIGH END WOULD BE 5
WITH MORE LIKELY THE 1 TO 3 RANGE. HAVE ISSUED THE WSW BASED ON
THE EXPECTED SIGNIFICANT AMOUNT OF SLEET AT THE START EVEN THROUGH
COUNTY AVERAGES ARE BELOW THE 3 INCH CRITERIA. IN ADDITION...TEMPS
BELOW FREEZING IN THE ADVISORY AREA WILL MAKE FOR A SIGNIFICANT
IMPACT ON TRAVEL.
WITH THE LOSS OF COLD CLOUD SEEDER/FEEDER NUCLEATION...PCPN IN
THE ADVISORY AREA MY END AS LIGHT FREEZING DRIZZLE.
THE I-84 CORRIDOR IN CT SHOULD ALSO GET ACCUMULATIONS. THUS THESE
AREAS ARE IN THE HWO PRODUCT AND WILL ISSUE AN SPECIAL WEATHER
STATEMENT ONCE RULES ALLOW.
ALONG THE COAST...SEE ALL RAIN. THINK THE POTENTIAL FOR AN SLEET
IS TOO LOW TO MENTION.
EXPECT PCPN TO END QUICKLY SATURDAY AM WITH CLOUDS GIVING WAY TO
AFTERNOON SUNSHINE.
TEMPS RISE TO THE UPPER 30S TO LOWER 40S SATURDAY (GFS MOS USED)...WHICH
IS SLIGHTLY BELOW NORMAL.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE KEEPS THE REGION DRY SATURDAY NIGHT AND MOST OF THE
DAYTIME HOURS OF SUNDAY WITH BELOW-NORMAL TEMPS.
FOR LATE-DAY SUNDAY THROUGH MONDAY NIGHT...MODELS IN GOOD AGREEMENT
THAT LOW PRESSURE SHIFTS IN FROM THE SOUTH AND WEST...BRINGING
PCPN MAINLY SUNDAY NIGHT THROUGH MONDAY AFTERNOON. THERE IS A
CHANCE HOWEVER THAT THE SOUTHERNMOST PORTIONS OF THE FORECAST AREA
SEE SOME LIGHT SNOW OR FLURRIES DEVELOP RIGHT BEFORE SUNSET ON
SUNDAY. PCPN EVENTUALLY BECOMES LIKELY FOR THE CITY AND OTHER
SOUTHERN SECTIONS BY MIDNIGHT...THEN LIKELY FARTHER NORTH AND EAST
AROUND OR SHORTLY AFTER MIDNIGHT.
FORECAST BUFKIT SOUNDINGS SHOW AN ELEVATED WARM LAYER
DEVELOPING...RESULTING IN MIXED PCPN TYPES. COMPLICATING THE
PCPN TYPE FORECAST FURTHER WILL BE COOLING OF BOUNDARY LAYER AND
SURFACE TEMPS DUE TO WET-BULBING...FOLLOWED BY ONSHORE WINDS THAT
WOULD PUSH TEMPS BACK UP OVERNIGHT SUNDAY NIGHT.
DUE TO THE PCPN TYPE COMPLICATIONS...THE FORECAST WILL PROBABLY
NEED TO BE CHANGED AS THE EVENT DRAWS CLOSER. BUT AT THIS POINT
FOR THE CITY AND COASTAL SECTIONS IT LOOKS LIKE SNOW AT THE ONSET
AS WET-BULBING WOULD PROBABLY OFFSET ANY BOUNDARY LAYER WARMTH THAT
WOULD OTHERWISE SUPPORT RAINFALL. MIXED RAIN/SLEET/SNOW WOULD THEN
FOLLOW HEADING CLOSER TOWARDS MIDNIGHT. A CHANGEOVER TO RAIN WOULD
THEN LIKELY OCCUR DURING THE LATE NIGHT HOURS. FOR INLAND
SPOTS...PRIMARILY SNOW FOR A DECENT PORTION OF THE NIGHT FOLLOWED BY
A WINTRY MIX LATE. A CHANGEOVER TO RAIN PROBABLY OCCURS BY LATE
MORNING FOR MOST INLAND SPOTS. LIGHT SNOW/SLEET ACCUMULATIONS WOULD
BE POSSIBLE...BUT PRIMARILY INLAND. WHATEVER LITTLE ACCUMULATION THE
CITY/COAST COULD MANAGE WOULD BE WASHED AWAY FAIRLY QUICKLY BY RAIN
AND WARMING TEMPS.
THE SYSTEM HEADS OUT TO SEA ON MONDAY NIGHT WITH A CHANCE OF
LINGERING PCPN THROUGH TUESDAY MORNING AS MODELS HINT AT A WEAK
WAVE OF LOW PRESSURE FORMING ALONG A FRONTAL BOUNDARY TO THE SOUTH
AND KEEPING PCPN CLOSE TO US. SHOULD THERE STILL BE PCPN DURING
THIS PERIOD...IT WOULD LIKELY BE RAIN CHANGING OVER TO A WINTRY
MIX...WITH THE CHANGE FIRST OCCURRING INLAND MONDAY NIGHT...THEN FOR
COASTAL SECTIONS LATE AT NIGHT INTO TUESDAY MORNING.
HIGH PRESSURE BUILDS IN FOR TUESDAY NIGHT THROUGH THURSDAY WITH DRY
WEATHER...BUT WITH COLDER THAN NORMAL TEMPERATURES.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
COLD FRONT NOW WELL SOUTHEAST OF LONG ISLAND. MARGINAL CIGS
THIS AFTERNOON WITH RA.
IFR TNGT WITH RAIN. GRADUAL MIXING WITH SLEET AND SNOW FROM NW TO
SE. ALL RAIN AT THE CITY TERMINALS THRU 6Z...WITH SOME MIXING
POSSIBLE BY 12Z. PROB IS TO LOW ATTM TO INCLUDE IN THE TAFS.
LGT SLY FLOW AHEAD OF THE FRONT...WITH WINDS NW BEHIND. GUSTS UP
TO 20KT.
...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)
KEWR FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES
SLANT RANGE VISIBILITY 4-6SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
KLGA FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
KTEB FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
KHPN FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
KISP FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 17Z.
.OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
.SAT...BECOMING VFR BY AFTN. NW WIND 10-20KT.
.SUN...VFR. LGT WIND.
.SUN NGT...MVFR OR LOWER. SNOW/SLEET/FZRA INTERIOR.
SNOW/SLEET/RAIN COAST.
.MON...IFR. RA. SE WND 15-25KT BECOMING SW IN AFTN.
.TUE...VFR. W WIND 15-25KT.
&&
.MARINE...
COLD FRONT NOW WELL SOUTH OF THE OCEAN COASTAL WATERS.
OVERALL...WINDS BELOW SCA CRITERIA...BUT OCEAN WAVES WILL TAKE A
WHILE TO SUBSIDE. OVERNIGHT...WINDS INCREASE FOR A SHORT TIME
LATE AS A WAVE OF LOW PRESSURE PASSES JUST TO THE SOUTH. WAVES ON
THE OCEAN SHOULD SUBSIDE TO JUST BELOW SCA LEVELS.
SCA CONDITIONS ARE POSSIBLE SATURDAY NIGHT OVER THE OCEAN
WATERS...OTHERWISE TRANQUIL. WINDS AND SEAS INCREASE WITH AN
APPROACHING STORM SUNDAY NIGHT AND MONDAY. SCA CONDITIONS EXPECTED
WITH THIS STORM.
&&
.HYDROLOGY...
PRECIPITATION THROUGH SATURDAY IS EXPECTED TO TOTAL NEAR AN
INCH. NO HYDROLOGIC ISSUES ANTICIPATED.
A STORM SYSTEM COULD BRING A LIQUID EQUIVALENT PRECIPITATION AMOUNT
OF A HALF INCH TO AN INCH FROM LATE SUNDAY AFTERNOON THROUGH MONDAY
NIGHT.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD
EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS
WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL
WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES
TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
SATURDAY FOR NYZ067-068.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...TONGUE
NEAR TERM...TONGUE
SHORT TERM...TONGUE/PW
LONG TERM...JC
AVIATION...MPS
MARINE...JC/PW
HYDROLOGY...JC/PW
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
950 AM EST FRI DEC 6 2013
.SYNOPSIS...
A COLD FRONT CROSSES THE REGION EARLY TODAY. LOW PRESSURE RIDES THE
STALLED FRONT TONIGHT WITH HIGH PRESSURE BUILDING IN FOR THE
WEEKEND. LOW PRESSURE RETURNS SUNDAY NIGHT AND IMPACTS THE
NORTHEAST THROUGH THE FIRST HALF OF NEXT WEEK. HIGH PRESSURE
BUILDS IN FOR THE SECOND HALF.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
THE GOES WATER VAPOR IMAGERY TELLS THE PICTURE WITH A RIVER OF
MOISTURE FROM THE CENTRAL PACIFIC TO NEWFOUNDLAND.
SFC COLD FRONT SEEN ON RADAR AND IN THE OBS OFF SOUTH OF LONG
ISLAND AS OF 1430Z. LATEST HRRR AND RADAR SUPPORTS LIGHT RA
ENDING FROM WEST TO EAST FOR THE LUNCH HOUR AND THEN REFORMING
THIS AFTERNOON AS WAVE OF WEAK LOW PRESSURE RIDE ALONG THE FRONT.
TEMPS FALLING IN THE COLD ADVECTION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/...
CURRENTLY EVALUATING NEEDS FOR WINTER WX ADVISORY FOR ORANGE AND
PUTNAM COUNTIES. HOPE TO HAVE A DECISION BY 11 AM.
UPPER SW FLOW PREVAILS THIS TIME FRAME. COLD FRONT SAGS
FURTHER SOUTH IN TIME...AS RIDGE OF HIGH PRESSURE BUILDS FROM THE
WEST.
FOR TONIGHT...COLDER AIR CONTINUES TO FILTER IN FROM THE NORTH.
RAIN WILL BECOME WIDESPREAD OVER THE AREA...TO THE NORTH OF THE
WAVE OF LOW PRESSURE. A TRANSITION FROM RAIN TO SNOW/SLEET WILL
OCCUR FROM NORTH TO SOUTH AS THE NIGHT PROGRESSES.
AT THIS TIME...ANALYSIS OF MODEL SOUNDINGS AND LOW LEVEL
THICKNESS PROFILES WOULD SUGGEST RAIN AND SLEET IN THE EVENING
OVER THE NW ZONES WILL TRANSITION TO SNOW/SLEET IN TIME. MAINLY
RAIN NEAR THE COAST TONIGHT...WITH PERHAPS SOME SLEET MIXING IN
FROM TIME TO TIME...ESPECIALLY AFTER MIDNIGHT.
DO NOT FORESEE MUCH IN THE WAY OF FREEZING RAIN AND THUS SIGNIFICANT
ICING BEHIND THE FRONT. AS SUCH...NO WINTER HEADLINES ARE PLANNED AT
THIS TIME.
MINOR SNOW ACCUMS THOUGH ARE EXPECTED ACROSS THE INTERIOR BY SAT
MORNING. ORANGE COUNTY COULD SEE AN INCH OR TWO OF SNOW...ALONG WITH
SOME SLEET ACCUM.
CLOUDS IN THE MORNING GIVE WAY TO AFTERNOON SUNSHINE.
CHILLY TEMPS RANGING FROM AROUND 30 INLAND TO THE MIDDLE 30S NEAR
THE COAST LATE TONIGHT ARE ANTICIPATED. THEN TEMPS RISE TO THE UPPER
30S TO LOWER 40S SATURDAY...WHICH IS SLIGHTLY BELOW NORMAL. A
MET/MAV MOS BLEND FOLLOWED.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
HIGH PRESSURE KEEPS THE REGION DRY SATURDAY NIGHT AND MOST OF THE
DAYTIME HOURS OF SUNDAY WITH BELOW-NORMAL TEMPS.
FOR LATE-DAY SUNDAY THROUGH MONDAY NIGHT...MODELS IN GOOD AGREEMENT
THAT LOW PRESSURE SHIFTS IN FROM THE SOUTH AND WEST...BRINGING
PCPN MAINLY SUNDAY NIGHT THROUGH MONDAY AFTERNOON. THERE IS A
CHANCE HOWEVER THAT THE SOUTHERNMOST PORTIONS OF THE FORECAST AREA
SEE SOME LIGHT SNOW OR FLURRIES DEVELOP RIGHT BEFORE SUNSET ON
SUNDAY. PCPN EVENTUALLY BECOMES LIKELY FOR THE CITY AND OTHER
SOUTHERN SECTIONS BY MIDNIGHT...THEN LIKELY FARTHER NORTH AND EAST
AROUND OR SHORTLY AFTER MIDNIGHT.
FORECAST BUFKIT SOUNDINGS SHOW AN ELEVATED WARM LAYER
DEVELOPING...RESULTING IN MIXED PCPN TYPES. COMPLICATING THE
PCPN TYPE FORECAST FURTHER WILL BE COOLING OF BOUNDARY LAYER AND
SURFACE TEMPS DUE TO WET-BULBING...FOLLOWED BY ONSHORE WINDS THAT
WOULD PUSH TEMPS BACK UP OVERNIGHT SUNDAY NIGHT.
DUE TO THE PCPN TYPE COMPLICATIONS...THE FORECAST WILL PROBABLY
NEED TO BE CHANGED AS THE EVENT DRAWS CLOSER. BUT AT THIS POINT
FOR THE CITY AND COASTAL SECTIONS IT LOOKS LIKE SNOW AT THE ONSET
AS WET-BULBING WOULD PROBABLY OFFSET ANY BOUNDARY LAYER WARMTH THAT
WOULD OTHERWISE SUPPORT RAINFALL. MIXED RAIN/SLEET/SNOW WOULD THEN
FOLLOW HEADING CLOSER TOWARDS MIDNIGHT. A CHANGEOVER TO RAIN WOULD
THEN LIKELY OCCUR DURING THE LATE NIGHT HOURS. FOR INLAND
SPOTS...PRIMARILY SNOW FOR A DECENT PORTION OF THE NIGHT FOLLOWED BY
A WINTRY MIX LATE. A CHANGEOVER TO RAIN PROBABLY OCCURS BY LATE
MORNING FOR MOST INLAND SPOTS. LIGHT SNOW/SLEET ACCUMULATIONS WOULD
BE POSSIBLE...BUT PRIMARILY INLAND. WHATEVER LITTLE ACCUMULATION THE
CITY/COAST COULD MANAGE WOULD BE WASHED AWAY FAIRLY QUICKLY BY RAIN
AND WARMING TEMPS.
THE SYSTEM HEADS OUT TO SEA ON MONDAY NIGHT WITH A CHANCE OF
LINGERING PCPN THROUGH TUESDAY MORNING AS MODELS HINT AT A WEAK
WAVE OF LOW PRESSURE FORMING ALONG A FRONTAL BOUNDARY TO THE SOUTH
AND KEEPING PCPN CLOSE TO US. SHOULD THERE STILL BE PCPN DURING
THIS PERIOD...IT WOULD LIKELY BE RAIN CHANGING OVER TO A WINTRY
MIX...WITH THE CHANGE FIRST OCCURRING INLAND MONDAY NIGHT...THEN FOR
COASTAL SECTIONS LATE AT NIGHT INTO TUESDAY MORNING.
HIGH PRESSURE BUILDS IN FOR TUESDAY NIGHT THROUGH THURSDAY WITH DRY
WEATHER...BUT WITH COLDER THAN NORMAL TEMPERATURES.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
COLD FRONT NOW EAST OF THE TERMINALS CONTINUES TO DEPART.
BRIEF PERIOD OF IFR CIGS THROUGH 15-16Z...OTHERWISE...CIGS RANGING
FROM 2500-3500 FT. LINGERING RAIN MOVING THROUGH THE REGION WILL
GENERALLY RESULT IN MVFR VSBY AT WORST.
IFR TNGT WITH RAIN. GRADUAL MIXING WITH SLEET AND SNOW FROM NW TO
SE. ALL RAIN AT THE CITY TERMINALS THRU 6Z...WITH SOME MIXING
POSSIBLE BY 12Z. PROB IS TO LOW ATTM TO INCLUDE IN THE TAFS.
LGT SLY FLOW AHEAD OF THE FRONT...WITH WINDS NW BEHIND. GUSTS UP
TO 20KT.
...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)
KEWR FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES
SLANT RANGE VISIBILITY 4-6SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
KLGA FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
KTEB FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
KHPN FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 16Z.
KISP FCSTER COMMENTS: OCNL GUSTS TO 20 KT THRU 17Z.
.OUTLOOK FOR 12Z SATURDAY THROUGH TUESDAY...
.SAT...BECOMING VFR BY AFTN. NW WIND 10-20KT.
.SUN...VFR. LGT WIND.
.SUN NGT...MVFR OR LOWER. SNOW/SLEET/FZRA INTERIOR.
SNOW/SLEET/RAIN COAST.
.MON...IFR. RA. SE WND 15-25KT BECOMING SW IN AFTN.
.TUE...VFR. W WIND 15-25KT.
&&
.MARINE...
THE COLD FRONT MOVE SOUTH OF THE OCEAN COASTAL WATERS.
OVERALL...WINDS BELOW SCA CRITERIA...BUT OCEAN WAVES WILL TAKE A
WHILE TO SUBSIDE. OVERNIGHT...WINDS MAY INCREASE SLIGHTLY FOR A
SHORT TIME LATE AS A WAVE OF LOW PRESSURE PASSES JUST TO THE
SOUTH. WAVES ON THE OCEAN SHOULD SUBSIDE TO JUST BELOW SCA LEVELS.
SCA CONDITIONS ARE POSSIBLE SATURDAY NIGHT OVER THE OCEAN
WATERS...OTHERWISE TRANQUIL. WINDS AND SEAS INCREASE WITH AN
APPROACHING STORM SUNDAY NIGHT AND MONDAY. SCA CONDITIONS EXPECTED
WITH THIS STORM.
&&
.HYDROLOGY...
PRECIPITATION THROUGH SATURDAY IS EXPECTED TO TOTAL AROUND AN
INCH...WITH MOSTLY RAIN EXPECTED. FLOODING IS NOT EXPECTED.
A STORM SYSTEM COULD BRING A LIQUID EQUIVALENT PRECIPITATION AMOUNT
OF A HALF INCH TO AN INCH FROM LATE SUNDAY AFTERNOON THROUGH MONDAY
NIGHT.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD
EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS
WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL
WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES
TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 PM EST THIS EVENING FOR ANZ350-
353-355.
&&
$$
SYNOPSIS...JC/PW
NEAR TERM...TONGUE/PW
SHORT TERM...TONGUE/PW
LONG TERM...JC
AVIATION...JMC
MARINE...JC/PW
HYDROLOGY...JC/PW
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1144 PM EST THU DEC 5 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 1258 PM EST THU DEC 5 2013
AN ACTIVE WEATHER PATTERN IS EXPECTED THE NEXT 24 HOURS AS WINTRY
WEATHER RETURNS TO CENTRAL INDIANA. A COLD FRONT HAS PUSHED
SOUTHEAST OF CENTRAL INDIANA...ALLOWING MUCH COLDER AIR TO PUSH IN
TO THE AREA. A FLOW OF MOIST AIR ALOFT ALONG WITH SEVERAL UPPER
LEVEL WEATHER DISTURBANCES ARE EXPECTED TO PUSH IN TO
CENTRAL INDIANA TONIGHT AND AGAIN ON FRIDAY. THIS WILL RESULT IN
ACCUMULATING SNOW TONIGHT AND FRIDAY FOR MOST OF CENTRAL
INDIANA...AND THE FIRST REAL BIG SNOW OF THE SEASON.
HIGH PRESSURE IS EXPECTED TO BUILD ACROSS THE AREA FRIDAY
NIGHT...ENDING THE SNOW. HOWEVER VERY COLD...ARCTIC AIR WILL ARRIVE
IN INDIANA...WITH TEMPERATURES WELL BELOW NORMAL THOUGH THE WEEKEND.
ANOTHER PASSING STORM SYSTEM MAY BRING SOME LIGHT SNOW OR FREEZING
PRECIPITATION TO AREA ON SUNDAY THROUGH MONDAY. YET ANOTHER SHOT
OF ARCTIC AIR IS THEN EXPECTED TO ARRIVE ON FOR THE MIDDLE OF NEXT
WEEK AND HIGH TEMPERATURES WILL ONLY BE IN THE TEENS.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 951 PM EST THU DEC 5 2013
NAM12 AND RUC13 MODEL SOUNDINGS AND OBSERVATIONAL TRENDS SUGGEST
PRECIPITATION TYPE WILL MAINLY BE SNOW THE REST OF THE NIGHT WITH
THE EXCEPTION OF THE FAR SOUTH...WHERE SOME SLEET IS POSSIBLE
THROUGH MIDNIGHT. LOOKING AT RAPID REFRESH REFLECTIVITY PROGS AND
WITH SHARP DEEP MOISTURE GRADIENT...SOME CONCERN NORTHWEST COUNTIES
WILL NOT SEE MUCH ACCUMULATION TONIGHT...BUT HATE TO PULL POPS AND
ACCUMULATION TOO SOON...SO FOR NOW WILL STICK WITH IT. UPDATED
GRIDS...HAZARDOUS WEATHER OUTLOOK AND WEATHER STORY WITH NEW WEB
STORM BRIEFING TO COME.
PREVIOUS DISCUSSION FOLLOWS...
RADAR THIS AFTERNOON SHOWS A SURGE OF MOISTURE OVER SOUTHERN
ILLINOIS STREAMING NORTHEAST TOWARD CENTRAL INDIANA. SURFACE
ANALYSIS EARLY THIS AFTERNOON SHOWS COLD HIGH PRESSURE IN PLACE
ACROSS THE CENTRAL PLAINS AND A COLD FRONT EAST OF INDIANA...OVER
CENTRAL OHIO...EASTERN KENTUCKY AND CENTRAL TENNESSEE. COLD WEST
TO NORTHWEST SURFACE FLOW WAS IN PLACE ACROSS CENTRAL INDIANA.
SURFACE TEMPS WERE FALLING THIS AFTERNOON ACROSS THE NORTHWEST
PARTS OF THE STATE AND BARELY RISING ACROSS SOUTH. THE WATER VAPOR
IMAGERY IS IMPORTANT TODAY. IT SHOWS A PLUME OF MOISTURE STREAMING
ACROSS MEXICO INTO THE AMERICAN SOUTHWEST AND THEN NORTHEAST INTO
THE GREAT LAKES AND OHIO VALLEY. THIS STREAM OF MOISTURE WILL BE
OUR SOURCE FOR PRECIP OVER THE NEXT 24-36 HOURS.
FORECAST SOUNDINGS ACROSS THE AREA LEAN TOWARD A FREEZING RAIN
PRECIP TYPE LATE THIS AFTERNOON AND THIS EVENING ACROSS SOUTHERN
PARTS OF CENTRAL INDIANA. PRECIPITABLE WATER VALUES AROUND 0.8
INDICATE PLENTY OF MOISTURE AVAILABLE FOR THIS SYSTEM. COLDER AIR
IS EXPECTED TO ARRIVE ACROSS THE ENTIRE FORECAST AREA AFTER 06Z AS
ALL FORECAST SOUNDINGS FALL BELOW FREEZING...CHANGING THE PRECIP
TYPE TO ALL SNOW REGION WIDE.
THUS HAVE TRENDED FORECASTS TOWARD 100 POPS...WITH BEST CHANCES
FOR FREEZING PRECIP ACROSS SOUTHERN PARTS OF THE FORECAST AREA
THIS EVENING. ALSO GIVEN THE EXPECTED PATH OF THE BAND OF
MOISTURE...SOUTHERN INDIANA IS IN THE MOST FAVORABLE POSITION FOR
HEAVIER SNOW AMOUNTS. AS FOR TEMPS...GIVEN THE COLD AIR ADVECTION
BUT EXPECTED PRECIPITATION...HAVE TRENDED LOWS AT OR ABOVE MAVMOS.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
ISSUED AT 1258 PM EST THU DEC 5 2013
SNOW IS EXPECTED ON FRIDAY. FORECAST SOUNDINGS AND TIME HEIGHT
SECTIONS CONTINUE TO SUGGEST A SATURATED COLUMN THROUGH THE DAY
WITH SOUNDINGS ENTIRELY BELOW FREEZING. FLOW ALOFT CONTINUES TO
SUGGEST THE MOIST SOUTHERN JET OF MOISTURE STREAMING IN TO THE
OHIO VALLEY. EMBEDDED SHORT WAVE ARE EXPECTED TO PROVIDE MORE
FORCING FOR ONGOING SNOW. TIME HEIGHT SECTIONS SHOW ANOTHER ROUND
OF GOOD VV DURING THE AFTERNOON HOURS. PRECIPITABLE WATER VIA
FORECAST SOUNDINGS SHOW A CONTINUOUS STREAM OF MOISTURE ACROSS THE
AREA WITH VALUES AROUND 0.60-0.80 FROM 12Z THROUGH 18Z AND AFTER
BEFORE TRAILING OFF AFTER 00Z SAT. THUS PLENTY OF MOISTURE APPEARS
AVAILABLE.
FRONTOGENESIS FORCING APPEARS VERY FAVORABLE FOR THIS
EVENT...AGAIN SHOWING A PERIOD STRONG FORCING MID DAY FRIDAY. THUS
WITH HIGH MOISTURE AND VERY GOOD FORCING EXPECT BANDS OF SNOW
ACROSS THE AREA ON FRIDAY. AGAIN...HEAVIEST AMOUNTS WILL BE ACROSS
THE SOUTHERN PARTS OF FORECAST AREA...WITH LIGHTER AMOUNTS NORTHWEST.
WITH ONGOING PRECIP EXPECTED ON FRIDAY HAVE TRENDED TEMPS COOLER
THAN MAV...STEADY IN THE UPPER 20S.
ON FRIDAY NIGHT...DEEP MOISTURE IS LOST IN THE FORECAST SOUNDINGS
AS BEST FORCING IS LOST AND THE SOUTHERN STREAM SHIFTS EAST. HIGH
PRESSURE OVER THE CENTRAL PLAINS CONTINUES TO BUILD ACROSS THE
REGION A COLD SURFACE RIDGE BUILDS ACROSS CENTRAL ILLINOIS AND
CENTRAL INDIANA. THUS WILL TREND TOWARD A BECOMING PARTLY CLOUDY
SKY. A FEW LINGERING SNOW SHOWERS OR FLURRIES WILL BE POSSIBLE
ACROSS THE EAST AS FRIDAY/S SYSTEM DEPARTS.
HIGH PRESSURE WILL PROVIDE COLD BUT DRY WEATHER FOR SATURDAY.
FORECAST SOUNDINGS REMAIN QUITE DRY. THUS WILL TREND TOWARD A
PARTLY CLOUDY SKY. AS FOR TEMPS DURING THIS PERIOD...GIVEN THE
EXPECTED FRESH SNOW AND COLD AIR IN PLACE WILL TREND HIGHS AND
LOWS COOLER THAN MAVMOS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
ISSUED AT 252 PM EST THU DEC 5 2013
MAIN ISSUE IN THE LONG TERM IS ANOTHER WINTER SYSTEM POSSIBLY
IMPACTING THE AREA EARLY SUNDAY INTO SUNDAY NIGHT. MODELS APPEAR
THEY MAY BE TRENDING SLIGHTLY COOLER MAINLY DURING THE DAY ON
SUNDAY. PRECIP MAY SNEAK INTO THE SOUTHERN FORECAST AREA AROUND
DAYBREAK SUNDAY IN THE FORM OF SNOW...WITH LIGHT SNOW POTENTIALLY
ACROSS MUCH OF THE AREA SUNDAY MORNING. PRECIP MAY TRANSITION TO A
MIX OF SLEET AND SNOW WITH SOME FREEZING RAIN POSSIBLE ACROSS THE
SOUTHWEST SUNDAY AFTERNOON. THIS MIX POTENTIAL WILL EXPAND A BIT
FURTHER NORTHWEST SUNDAY EVENING BEFORE COLD AIR AGAIN OVERTAKES THE
AREA AND MOST PRECIP LATE SUNDAY NIGHT CHANGES BACK TO SNOW...WITH
THE EXCEPTION OF A LIGHT MIX POSSIBLE IN THE EAST.
AMOUNTS WITH THIS SYSTEM...WHILE STILL QUITE UNCERTAIN BEING SO FAR
OUT...APPEAR VERY LIGHT ACROSS MOST OF THE FORECAST AREA. ACROSS THE
SOUTHEASTERN HALF OF THE AREA...FROM VINCENNES TO INDIANAPOLIS AND
MUNCIE SOUTHEASTWARD...1-3 INCHES OF SNOW/SLEET APPEAR POSSIBLE WITH
POTENTIAL FOR A FEW HUNDREDTHS OF FREEZING RAIN. SNOW/SLEET
ACCUMULATIONS OF UP TO 4 INCHES APPEAR POSSIBLE ACROSS THE FAR
SOUTHEASTERN FORECAST AREA...IN THE NORTH VERNON AREA.
ONCE THIS SYSTEM EXITS...DRY WEATHER WILL DOMINATE THE REMAINDER OF
THE FORECAST PERIOD...AND TEMPS WILL TURN SHARPLY COLDER. HIGHS MAY
NOT GET OUT OF THE TEENS AT TIMES NEXT WEEK. ALLBLEND HANDLED THE
OUTER PERIODS WELL AND FEW CHANGES WERE REQUIRED.
&&
.AVIATION /DISCUSSION FOR 060600Z TAF ISSUANCE/...
ISSUED AT 1135 PM EST THU DEC 5 2013
IFR AND LOWER CONDITIONS EXPECTED AT ALL BUT KLAF WITH LIGHT TO
MODERATE SNOW FALLING THROUGH THE OVERNIGHT AND THROUGH THE DAY
FRIDAY. VISIBILITIES IN THE SNOW ARE GENERALLY RUNNING 1 TO 2
MILES WITH SHORT BOUTS OF 1/4 TO 3/4SM WHEN A HEAVIER BAND
DEVELOPS. LOOKING AT UPSTREAM OBSERVATIONS AND FORECAST SOUNDINGS
LOOKS LIKE THE BEST SHOT FOR THIS TO HAPPEN AGAIN AT THE SITES WILL
BE IN THE 6 TO 9Z TIMEFRAME AT KHUF AND KIND AND A BIT LATER AT
KBMG SO WILL CONTINUE TO TEMPO IN THE LOWER CONDITIONS THEN. LIGHT TO
MODERATE SNOWFALL WILL CONTINUE THROUGH THE DAY FRIDAY WITH IFR
CONDITIONS EXPECTED. SNOW COULD OCCUR FOR A FEW HOURS AT KLAF FROM
LATE MORNING TO MID AFTERNOON BUT EXPECT MVFR THERE. CONDITIONS
SHOULD START TO IMPROVE BY 0Z SATURDAY AS THE WINTER SYSTEM MOVES
OUT OF THE AREA.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL MIDNIGHT EST FRIDAY NIGHT FOR INZ037-
039>042-044>049-051>057-060>065-067>072.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST FRIDAY NIGHT FOR
INZ021-028>031-035-036-038-043.
&&
$$
SYNOPSIS...PUMA
NEAR TERM...PUMA/MK
SHORT TERM...PUMA
LONG TERM....NIELD
AVIATION...CP
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS DES MOINES IA
1128 AM CST FRI DEC 6 2013
.SHORT TERM /TODAY/...
ISSUED AT 347 AM CST FRI DEC 6 2013
PRIMARY CONCERN TODAY WILL BE TEMP AND WIND CHILL TRENDS. STRONG
CENTRAL PLAINS TO GREAT LAKES JET...08Z RAP MAX WIND OBJECTIVELY
ANALYZED AT 180KTS OVER SRN WI...IS IN PLACE BUT MUCH OF THE
ASSOCIATED FORCING AND RESULTANT SENSIBLE WEATHER IS WELL TO OUR
SOUTH. A FEW WEAK SHORT WAVES WITH MID LEVEL KINEMATIC FORCING ARE
RIDING THE JET BUT WITH LIMITED MOISTURE ARE PRODUCING NOTHING MORE
THAN MID CLOUDS AND LIGHT SNOW ALOFT SO FORECAST REMAINS DRY.
RECENT RAP/NAM RUNS SEEM TO HAVE A BETTER HANDLE ON THIS ARCTIC
AIRMASS THAN THE GFS...AND ARE ALSO SUPPORTED BY HI RES NMM AND
HOPWRF RUNS. THIS THINKING WOULD SUGGEST HIGHS ONLY MAKING THE MID
SINGLE DIGITS NW TO MID TEENS SE TODAY. WINDS WILL CHANGE LITTLE
TODAY...REMAINING STEADY FROM THE NW AROUND 10KTS PLUS...KEEPING
WIND CHILLS AT OR BELOW ADVISORY CRITERIA /-20F/ THROUGH MUCH OF THE
MORNING. NO CHANGES TO EXISTING HEADLINE.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 347 AM CST FRI DEC 6 2013
TONIGHT THROUGH SATURDAY WILL BE RELATIVELY QUIET WITH RESPECT TO
PRECIPITATION BUT IT WILL BE VERY COLD. THE ARCTIC HIGH WILL PUSH
SOUTH AND EAST ACROSS THE AREA THROUGH THIS TIME. THE GRADIENT
WILL RELAX ACROSS IOWA SO THE WIND WILL DIMINISH SOME THROUGH THIS
EVENING BUT WITH CLEAR SKIES TEMPERATURES WILL QUICKLY FALL.
ANOTHER WIND CHILL ADVISORY WILL LIKELY BE NEEDED FOR TONIGHT BUT
TO AVOID CONFUSION OVER ADDITIONAL HEADLINES I LEFT THAT DECISION
FOR THE DAY SHIFT. NONETHELESS IT WILL REMAIN COLD.
ATTENTION THEN TURNS TO THE SYSTEM COMING IN FOR SUNDAY. A DEEP
UPPER LEVEL TROUGH OVER THE WEST WILL SHIFT INTO THE PLAINS
SATURDAY NIGHT THEN ACROSS THE UPPER MIDWEST SUNDAY AND SUNDAY
NIGHT. AT THE SURFACE A LOW WILL SWING OUT OF THE SOUTHWEST INTO
NORTHERN MISSOURI THEN NORTH CENTRAL ILLINOIS SUNDAY EVENING.
THERE WILL BE SEVERAL WAVES MOVE ACROSS IOWA DURING THIS TIME SO
IT LOOKS AS THOUGH SOME LIGHT SNOW WILL BE POSSIBLE LATE SATURDAY
NIGHT WITH THE FIRST WAVE OF THETA-E ADVECTION THEN AS THE PIECES
OF ENERGY COME ACROSS IOWA SUNDAY THERE WILL BE GENERALLY A LIGHT
TO MODERATE SNOWFALL WITH PERIODS OF MODERATE SNOWFALL. THE LAST
COUPLE OF DAYS THE MODELS HAVE BEEN SUGGESTING A 2 TO 5 INCH SNOW
FALL ACROSS CENTRAL IOWA WITH 2 INCHES ACROSS THE SOUTHEAST AND 5
ACROSS THE FAR NORTHWEST AND WEST. SNOW TO LIQUID RATIONS CONTINUE
TO BE FROM 15 TO 25 TO 1 SO IT WILL NOT TAKE MUCH QPF TO GET
MEASURABLE SNOW. THERE IS STILL SOME UNCERTAINTIES IN THE FINER
DETAILS WHICH WILL PRECLUDE ANY HEADLINES AT THIS TIME BUT WE WILL
CONTINUE TO MONITOR TRENDS.
THE SYSTEM WILL DEPART EARLY MONDAY THEN ANOTHER BLAST OF COLD AIR
WILL COME LATE MONDAY AND TUESDAY USHERED IN BY SOME STRONG WIND.
HOWEVER WITH THE FRESH SNOW FROM SUNDAY...THE WIND MAY CREATE SOME
ISSUES WITH VISIBILITY. WE WILL BE MONITORING THAT AS WELL BUT
WILL GET A BETTER HANDLE ON THAT ONCE WE SEE WHERE THE HEAVIEST
SNOW FALLS. TEMPS MAY MODERATE SOME BY LATE IN THE EXTENDED BUT I
AM NOT PUTTING MUCH WEIGHT IN THAT AS THIS IS DAY 6 AND 7 AND WE
ARE GOING TO HAVE SNOW ON THE GROUND WHICH WILL DEFINITELY IMPACT
TEMPS.
&&
.AVIATION...06/18Z
ISSUED AT 1125 AM CST FRI DEC 6 2013
VFR CONDITIONS EXPECTED AT SITES THROUGH PERIOD. WINDS WILL REMAIN
TO THE NORTHWEST AND BECOME LIGHTER AFTER 00Z.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...SMALL
LONG TERM...FAB
AVIATION...AWB
AREA FORECAST DISCUSSION
NWS DES MOINES IA
541 AM CST FRI DEC 6 2013
.SHORT TERM /TODAY/...
ISSUED AT 347 AM CST FRI DEC 6 2013
PRIMARY CONCERN TODAY WILL BE TEMP AND WIND CHILL TRENDS. STRONG
CENTRAL PLAINS TO GREAT LAKES JET...08Z RAP MAX WIND OBJECTIVELY
ANALYZED AT 180KTS OVER SRN WI...IS IN PLACE BUT MUCH OF THE
ASSOCIATED FORCING AND RESULTANT SENSIBLE WEATHER IS WELL TO OUR
SOUTH. A FEW WEAK SHORT WAVES WITH MID LEVEL KINEMATIC FORCING ARE
RIDING THE JET BUT WITH LIMITED MOISTURE ARE PRODUCING NOTHING MORE
THAN MID CLOUDS AND LIGHT SNOW ALOFT SO FORECAST REMAINS DRY.
RECENT RAP/NAM RUNS SEEM TO HAVE A BETTER HANDLE ON THIS ARCTIC
AIRMASS THAN THE GFS...AND ARE ALSO SUPPORTED BY HI RES NMM AND
HOPWRF RUNS. THIS THINKING WOULD SUGGEST HIGHS ONLY MAKING THE MID
SINGLE DIGITS NW TO MID TEENS SE TODAY. WINDS WILL CHANGE LITTLE
TODAY...REMAINING STEADY FROM THE NW AROUND 10KTS PLUS...KEEPING
WIND CHILLS AT OR BELOW ADVISORY CRITERIA /-20F/ THROUGH MUCH OF THE
MORNING. NO CHANGES TO EXISTING HEADLINE.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 347 AM CST FRI DEC 6 2013
TONIGHT THROUGH SATURDAY WILL BE RELATIVELY QUIET WITH RESPECT TO
PRECIPITATION BUT IT WILL BE VERY COLD. THE ARCTIC HIGH WILL PUSH
SOUTH AND EAST ACROSS THE AREA THROUGH THIS TIME. THE GRADIENT
WILL RELAX ACROSS IOWA SO THE WIND WILL DIMINISH SOME THROUGH THIS
EVENING BUT WITH CLEAR SKIES TEMPERATURES WILL QUICKLY FALL.
ANOTHER WIND CHILL ADVISORY WILL LIKELY BE NEEDED FOR TONIGHT BUT
TO AVOID CONFUSION OVER ADDITIONAL HEADLINES I LEFT THAT DECISION
FOR THE DAY SHIFT. NONETHELESS IT WILL REMAIN COLD.
ATTENTION THEN TURNS TO THE SYSTEM COMING IN FOR SUNDAY. A DEEP
UPPER LEVEL TROUGH OVER THE WEST WILL SHIFT INTO THE PLAINS
SATURDAY NIGHT THEN ACROSS THE UPPER MIDWEST SUNDAY AND SUNDAY
NIGHT. AT THE SURFACE A LOW WILL SWING OUT OF THE SOUTHWEST INTO
NORTHERN MISSOURI THEN NORTH CENTRAL ILLINOIS SUNDAY EVENING.
THERE WILL BE SEVERAL WAVES MOVE ACROSS IOWA DURING THIS TIME SO
IT LOOKS AS THOUGH SOME LIGHT SNOW WILL BE POSSIBLE LATE SATURDAY
NIGHT WITH THE FIRST WAVE OF THETA-E ADVECTION THEN AS THE PIECES
OF ENERGY COME ACROSS IOWA SUNDAY THERE WILL BE GENERALLY A LIGHT
TO MODERATE SNOWFALL WITH PERIODS OF MODERATE SNOWFALL. THE LAST
COUPLE OF DAYS THE MODELS HAVE BEEN SUGGESTING A 2 TO 5 INCH SNOW
FALL ACROSS CENTRAL IOWA WITH 2 INCHES ACROSS THE SOUTHEAST AND 5
ACROSS THE FAR NORTHWEST AND WEST. SNOW TO LIQUID RATIONS CONTINUE
TO BE FROM 15 TO 25 TO 1 SO IT WILL NOT TAKE MUCH QPF TO GET
MEASURABLE SNOW. THERE IS STILL SOME UNCERTAINTIES IN THE FINER
DETAILS WHICH WILL PRECLUDE ANY HEADLINES AT THIS TIME BUT WE WILL
CONTINUE TO MONITOR TRENDS.
THE SYSTEM WILL DEPART EARLY MONDAY THEN ANOTHER BLAST OF COLD AIR
WILL COME LATE MONDAY AND TUESDAY USHERED IN BY SOME STRONG WIND.
HOWEVER WITH THE FRESH SNOW FROM SUNDAY...THE WIND MAY CREATE SOME
ISSUES WITH VISIBILITY. WE WILL BE MONITORING THAT AS WELL BUT
WILL GET A BETTER HANDLE ON THAT ONCE WE SEE WHERE THE HEAVIEST
SNOW FALLS. TEMPS MAY MODERATE SOME BY LATE IN THE EXTENDED BUT I
AM NOT PUTTING MUCH WEIGHT IN THAT AS THIS IS DAY 6 AND 7 AND WE
ARE GOING TO HAVE SNOW ON THE GROUND WHICH WILL DEFINITELY IMPACT
TEMPS.
&&
.AVIATION...06/12Z
ISSUED AT 541 AM CST FRI DEC 6 2013
VFR CONDITIONS ANTICIPATED THROUGH THE PERIOD. MOSTLY CLEAR NORTH
WITH MID CLOUD CIGS THROUGHOUT THE DAY SOUTHEAST. NW WINDS WILL
REMAIN STEADY AND CHANGE LITTLE.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR CALHOUN-CERRO GORDO-
EMMET-HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-
WINNEBAGO-WORTH.
&&
$$
SHORT TERM...SMALL
LONG TERM...FAB
AVIATION...SMALL
AREA FORECAST DISCUSSION
NWS DES MOINES IA
407 AM CST FRI DEC 6 2013
.SHORT TERM /TODAY/...
ISSUED AT 347 AM CST FRI DEC 6 2013
PRIMARY CONCERN TODAY WILL BE TEMP AND WIND CHILL TRENDS. STRONG
CENTRAL PLAINS TO GREAT LAKES JET...08Z RAP MAX WIND OBJECTIVELY
ANALYZED AT 180KTS OVER SRN WI...IS IN PLACE BUT MUCH OF THE
ASSOCIATED FORCING AND RESULTANT SENSIBLE WEATHER IS WELL TO OUR
SOUTH. A FEW WEAK SHORT WAVES WITH MID LEVEL KINEMATIC FORCING ARE
RIDING THE JET BUT WITH LIMITED MOISTURE ARE PRODUCING NOTHING MORE
THAN MID CLOUDS AND LIGHT SNOW ALOFT SO FORECAST REMAINS DRY.
RECENT RAP/NAM RUNS SEEM TO HAVE A BETTER HANDLE ON THIS ARCTIC
AIRMASS THAN THE GFS...AND ARE ALSO SUPPORTED BY HI RES NMM AND
HOPWRF RUNS. THIS THINKING WOULD SUGGEST HIGHS ONLY MAKING THE MID
SINGLE DIGITS NW TO MID TEENS SE TODAY. WINDS WILL CHANGE LITTLE
TODAY...REMAINING STEADY FROM THE NW AROUND 10KTS PLUS...KEEPING
WIND CHILLS AT OR BELOW ADVISORY CRITERIA /-20F/ THROUGH MUCH OF THE
MORNING. NO CHANGES TO EXISTING HEADLINE.
.LONG TERM /TONIGHT THROUGH THURSDAY/...
ISSUED AT 347 AM CST FRI DEC 6 2013
TONIGHT THROUGH SATURDAY WILL BE RELATIVELY QUIET WITH RESPECT TO
PRECIPITATION BUT IT WILL BE VERY COLD. THE ARCTIC HIGH WILL PUSH
SOUTH AND EAST ACROSS THE AREA THROUGH THIS TIME. THE GRADIENT
WILL RELAX ACROSS IOWA SO THE WIND WILL DIMINISH SOME THROUGH THIS
EVENING BUT WITH CLEAR SKIES TEMPERATURES WILL QUICKLY FALL.
ANOTHER WIND CHILL ADVISORY WILL LIKELY BE NEEDED FOR TONIGHT BUT
TO AVOID CONFUSION OVER ADDITIONAL HEADLINES I LEFT THAT DECISION
FOR THE DAY SHIFT. NONETHELESS IT WILL REMAIN COLD.
ATTENTION THEN TURNS TO THE SYSTEM COMING IN FOR SUNDAY. A DEEP
UPPER LEVEL TROUGH OVER THE WEST WILL SHIFT INTO THE PLAINS
SATURDAY NIGHT THEN ACROSS THE UPPER MIDWEST SUNDAY AND SUNDAY
NIGHT. AT THE SURFACE A LOW WILL SWING OUT OF THE SOUTHWEST INTO
NORTHERN MISSOURI THEN NORTH CENTRAL ILLINOIS SUNDAY EVENING.
THERE WILL BE SEVERAL WAVES MOVE ACROSS IOWA DURING THIS TIME SO
IT LOOKS AS THOUGH SOME LIGHT SNOW WILL BE POSSIBLE LATE SATURDAY
NIGHT WITH THE FIRST WAVE OF THETA-E ADVECTION THEN AS THE PIECES
OF ENERGY COME ACROSS IOWA SUNDAY THERE WILL BE GENERALLY A LIGHT
TO MODERATE SNOWFALL WITH PERIODS OF MODERATE SNOWFALL. THE LAST
COUPLE OF DAYS THE MODELS HAVE BEEN SUGGESTING A 2 TO 5 INCH SNOW
FALL ACROSS CENTRAL IOWA WITH 2 INCHES ACROSS THE SOUTHEAST AND 5
ACROSS THE FAR NORTHWEST AND WEST. SNOW TO LIQUID RATIONS CONTINUE
TO BE FROM 15 TO 25 TO 1 SO IT WILL NOT TAKE MUCH QPF TO GET
MEASURABLE SNOW. THERE IS STILL SOME UNCERTAINTIES IN THE FINER
DETAILS WHICH WILL PRECLUDE ANY HEADLINES AT THIS TIME BUT WE WILL
CONTINUE TO MONITOR TRENDS.
THE SYSTEM WILL DEPART EARLY MONDAY THEN ANOTHER BLAST OF COLD AIR
WILL COME LATE MONDAY AND TUESDAY USHERED IN BY SOME STRONG WIND.
HOWEVER WITH THE FRESH SNOW FROM SUNDAY...THE WIND MAY CREATE SOME
ISSUES WITH VISIBILITY. WE WILL BE MONITORING THAT AS WELL BUT
WILL GET A BETTER HANDLE ON THAT ONCE WE SEE WHERE THE HEAVIEST
SNOW FALLS. TEMPS MAY MODERATE SOME BY LATE IN THE EXTENDED BUT I
AM NOT PUTTING MUCH WEIGHT IN THAT AS THIS IS DAY 6 AND 7 AND WE
ARE GOING TO HAVE SNOW ON THE GROUND WHICH WILL DEFINITELY IMPACT
TEMPS.
&&
.AVIATION...06/06Z
ISSUED AT 1129 PM CST THU DEC 5 2013
VFR CONDITIONS WITH BREEZY NORTHWEST WINDS WILL PERSIST THROUGH
THE PERIOD.
&&
.DMX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST TODAY FOR CALHOUN-CERRO GORDO-
EMMET-HANCOCK-HUMBOLDT-KOSSUTH-PALO ALTO-POCAHONTAS-SAC-
WINNEBAGO-WORTH.
&&
$$
SHORT TERM...SMALL
LONG TERM...FAB
AVIATION...DONAVON
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
310 AM CST FRI DEC 6 2013
.SYNOPSIS...
ISSUED AT 307 AM CST FRI DEC 6 2013
LATEST SURFACE ANALYSIS INDICATED A SURFACE RIDGE OF HIGH PRESSURE
BUILDING EAST SOUTHEASTWARD INTO IOWA AND ILLINOIS. A COLD FRONT
WAS DRAPED FROM THE SOUTHERN TIP OF TEXAS NORTHEAST TO NEW YORK.
MID AND HIGH LEVEL CLOUDINESS FROM THE NORTHWEST PERIPHERY OF THE
WINTER STORM SYSTEM TO THE SOUTH AND SOUTHEAST IS SEEN STREAMING
NORTHEAST ACROSS THE CWFA. NORTHWEST WINDS AT 8 TO 15 MPH WERE
OBSERVED AT 3AM...WITH A FEW GUSTS AROUND 20 MPH. TEMPERATURES
RANGE FROM 7 TO 17 DEGREES...WITH THE WARMER READINGS IN THE
SOUTHEAST...CLOSER TO THE SOUTHERN WINTER STORM.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 307 AM CST FRI DEC 6 2013
RELATIVELY QUIET AND COLD CONDITIONS WILL CHARACTERIZE THE WEATHER IN
THE SHORT TERM. ARCTIC HIGH PRESSURE WILL CONTINUE TO BUILD OVER
THE AREA OVER THE NEXT 24 HOURS. SOME MID AND HIGH LEVEL CLOUDINESS
WILL CONTINUE TO OVERSPREAD THE AREA FROM THE SOUTHWEST TODAY...WITH
CLEARING CONDITIONS TONIGHT. FLURRIES MAY BE POSSIBLE ACROSS THE
SOUTHEAST 1/4 OF THE CWFA...BUT OPTED TO LEAVE MENTION OUT OF GRIDS
AT THIS TIME. WINDS WILL REMAIN ON THE BLUSTERY SIDE THROUGH THE
MAJORITY OF THE PERIOD...DIMINISHING UNDER 10 MPH BY SATURDAY
MORNING. TEMPERATURES LOOK TO BE ON TRACK...WITH HIGHS TODAY
STRUGGLING TO REACH THE TEENS AND LOWER 20S. LOWERED MINS SAT
MORNING JUST A TAD WITH CLEAR SKIES AND LIGHTER WINDS...WITH MINS IN
THE MINUS 3 TO 8 ABOVE RANGE. WIND CHILLS THIS MORNING WILL SLIP
INTO THE LOWER SINGLE DIGITS ABOVE ZERO EAST NEAR PRINCETON
ILLINOIS...TO ABOUT MINUS 15 NEAR INDEPENDENCE. THIS AFTERNOON THEY
WILL BE BETWEEN 5 BELOW AND 10 ABOVE. WITH THE COLDER MINS SATURDAY
MORNING...WIND CHILLS WILL DROP TO BETWEEN 5 BELOW AND 18 BELOW ZERO.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 307 AM CST FRI DEC 6 2013
BELOW NORMAL TEMPERATURES ARE THE RULE THROUGHOUT THE EXTENDED
FORECAST. CHANCES FOR MEASURABLE SNOW CONTINUE FOR SUNDAY AND SUNDAY
NIGHT AS UPPER LEVEL IMPULSE IN THE NEARLY MERIDIONAL FLOW CURRENTLY
ALONG THE PACIFIC NW COAST ROUNDS THE BASE OF THE UPPER LEVEL TROUGH
AND PASSES THROUGH THE FORECAST AREA.
SATURDAY INTO SATURDAY NIGHT WILL BE DRY AND COLD AS HIGH PRESSURE
OVER THE NORTHERN ROCKIES PLAINS MIGRATES SE THROUGH THE AREA. WITH
A SIMILAR AIRMASS IN PLACE AS FRIDAY...HIGHS WILL ONLY MAKE THE
TEENS TO NEAR 20 IN THE FAR SOUTH. CLOUDS THICKEN SATURDAY NIGHT AS
MID AND UPPER LEVEL MOISTURE AND MODEST LIFT INCREASES AHEAD OF THE
APPROACHING SHORTWAVE. A DEVELOPING E-SE FLOW OF DRY AIR FROM THE
SURFACE THROUGH 850 MB SHOULD EFFECTIVELY EAT AWAY AT ANY ICE
CRYSTALS...HOLDING OFF THE ONSET OF FLURRIES UNTIL DAYLIGHT SUNDAY.
THE CLOUD COVER SHOULD KEEP MINIMUM TEMPERATURES WARMER THAN
PREVIOUS NIGHTS...FROM AROUND 10 NORTH TO THE LOWER TEENS ELSEWHERE.
SUNDAY AND SUNDAY NIGHT...LIGHT SNOW WILL OVERSPREAD THE AREA FROM
WEST TO EAST AS THE UPPER LEVEL VORT MAX AND INVERTED SURFACE TROUGH
MOVE THROUGH THE REGION. WHILE THERE ARE STILL MINOR DIFFERENCES
BETWEEN MODELS...THE OVERALL TREND IS TOWARD THE BEST UPPER LEVEL
FORCING PASSING OVERHEAD FROM MIDDAY INTO EARLY EVENING. MODEL QPF
AMOUNTS OF ROUGHLY .05 TO NEARLY .20...ALONG WITH A BRIEF WINDOW OF
LIFT IN THE IDEAL DENDRITIC GROWTH ZONE AND SURFACE TEMPERATURES
ONLY REACHING THE 20S...WOULD SUPPORT WIDESPREAD SNOWFALL AMOUNTS OF
AROUND 1 TO 3 INCHES. THE HIGHER TOTALS WILL LIKELY BE ACROSS THE NW
AND NORTH WITH LIGHTEST AMOUNTS IN THE SOUTHEAST. THE VORT MAX
PASSES TO THE NORTHEAST AFTER MIDNIGHT...ENDING THE LIGHT SNOW.
ALLOWING FOR SOME POSSIBLE FURTHER SLOWING OF THE SYSTEM...HAVE KEPT
CHANCE POPS GOING IN THE WEST...WHILE LIKELY POPS HANG ON IN THE FAR
NORTHEAST THROUGH THE NIGHT.
MONDAY THROUGH THURSDAY...THE FORECAST IS KEPT COLD AND DRY. THERE
WILL HOWEVER BE PERIODIC WEAK CLIPPER SYSTEMS IN THE MAINLY NW FLOW
ALOFT TO PROVIDE AT LEAST LOW CHANCES FOR FLURRIES OR LIGHT SNOW IN
THE VICINITY. AT THIS TIME...MODELS HAVE THE FIRST ONE PASSING TO
THE NORTHEAST ON TUESDAY...WITH ANOTHER AROUND WED OR WED NIGHT
POSSIBLY TAKING A MORE DIRECT PATH...BUT WITH SIGNIFICANTLY
DIFFERENT TIMING BETWEEN THE GFS AND ECMWF NO MENTION OF
PRECIPITATION IS INCLUDED IN THE FORECAST AT THIS TIME. THE BIGGER
STORY WILL BE THE CONTINUED COLD TEMPERATURES AS 850 MB TEMPERATURES
REMAIN IN THE SUB ZERO TEENS. FORECAST HIGHS IN THE TEENS TO MID 20S
AND LOWS IN THE SINGLE DIGITS MON THROUGH WED MAY BE TOO
OPTIMISTIC...ESPECIALLY IF THE SUNDAY SYSTEM LAYS NEW SNOW COVER
ACROSS THE AREA. THURSDAY AND BEYOND...THERE IS INDICATION OF A
WARMING TREND AS A SYSTEM DEVELOPS OUT WEST AND THIS IS REFLECTED
WITH HIGHS IN THE 20S TO POSSIBLY LOWER 30S IN THE SOUTH THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1150 PM CST THU DEC 5 2013
PATCHY LOW CLOUDS WITH AN OCCASIONAL MVFR CIG ARE CURRENTLY BEING
FOUND OVER NORTHEAST IOWA. LATEST RAP MODEL OUTLIER WITH
INCREASING THE LOW CLOUDS AND ADVECTING SOUTHEAST OVER MUCH OF
AREA ESPECIALLY NORTH OF I-80 OVERNIGHT AND FRIDAY MORNING.
WHILE SOME PRESENCE OF LOW LEVEL THETA-E AXIS AND LOW LEVEL
FRONTOGENESIS COULD FOSTER ADDITIONAL LOW CLOUDS NOT VERY CONFIDENT
TO MENTION ANY CIGS... BUT DID MAINTAIN SCATTERED CLOUD BASES
AROUND 2KFT AGL ONLY AT KDBQ FOR NOW BEING CLOSER TO THE ABOVE
MENTIONED FEATURES. OTHERWISE...VFR CONDITIONS WITH MID/HIGH
CLOUDINESS FROM STORM SYSTEM PASSING TO OUR SOUTH ON FRIDAY. WINDS
WILL REMAIN GENERALLY NORTHWEST AROUND 10-15 KTS WITH SOME LOCALLY
HIGHER GUSTS POSSIBLE AT TIMES.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...14
SHORT TERM...14
LONG TERM...SHEETS
AVIATION...05
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1150 PM CST THU DEC 5 2013
.SYNOPSIS...
ISSUED AT 318 PM CST THU DEC 5 2013
THE LATEST SFC ANALYSIS WAS INDICATING LARGE CANADIAN RIDGE AXIS
DRAPED FROM MT...DOWN INTO THE SOUTHEASTERN PLAINS AND LOWER MS RVR
VALLEY. THIS TO THE WEST OF LINGERING CYCLONIC PRESSURE GRADIENT
ACRS THE UPPER MS RVR VALLEY AND WESTERN GRT LKS AS OCCLUDED SFC LOW
COMPLEX SPIRALS JUST WEST OF JAMES BAY. VIS SATELLITE LOOP INDICATING
ESTABLISHED SNOW FIELDS ACRS MT...THE DAKOTAS...NORTHERN NEB...MN AND
NW WI. COLD LLVL NORTHWEST FETCH OFF THESE SNOW AREAS AND DOWN ACRS
IA. ALOFT...12Z UPPER AIR ANALYSIS AND MID/UPPER LEVEL MOISTURE FLOW
PATTERNS ON WATER VAPOR IMAGERY LOOP WAS SHOWING DEEP L/W TROF ACRS
MUCH OF THE WESTERN CONUS PIVOTING ACRS THE NORTHERN BAJA...WHILE
NEARLY STACKED UPPER LOW WAS ROLLING NORTHEASTWARD JUST WEST OF JAMES
BAY. THE W/V LOOP ALSO SHOWING LARGE SCALE/LONG FETCH MOISTURE FEED
FROM WELL WEST OF THE BAJA CA....UP ACRS MUCH OF THE SOUTHEASTERN
HALF OF THE CONUS.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 318 PM CST THU DEC 5 2013
TONIGHT...ALTHOUGH THE NORTHWESTERLY SFC WINDS WILL DECREASE TO
AROUND 10 TO 12 MPH OVERNIGHT...COLD AIR ADVECTION MACHINE STILL IN
FULL GEAR FROM NORTHERN PLAINS SOURCE REGION. STILL EXPECT ROUNDS
OF VARYING THICKNESS CIRRUS AND POSSIBLY SOME HIGHER BASED AC OFF
OVERRUNNING WINTER STORM SYSTEM ONGOING ACRS THE SOUTHERN PLAINS AND
UP THE OH RVR VALLEY. THUS MOSTLY CLOUDY TONIGHT...LITTLE OR NO
SNOW COVER...AND MIXING WINDS OF 10+ MPH WILL KEEP TEMPS FROM
BOTTOMING OUT TO SUBZERO READINGS. BUT STILL A COLD NIGHT IN STORE
WITH LOWS IN THE LOWER SINGLE DIGITS ABOVE ZERO IN THE FAR WEST AND
NORTHWEST...5-10 ABOVE TO THE MS RVR...AND LOWER TO MID TEENS EAST
OF THE MS RVR. THESE TEMPS COMBINED WITH THE WINDS TO PRODUCE WIND
CHILLS FROM ZERO..TO 10-12 BELOW ZERO WEST OF THE MS RVR LATE
TONIGHT AND THROUGH 6 AM CST FRI AM. WILL KEEP THE FCST DRY FOR
NOW...BUT EXTRAPOLATING SOME OF THE ELEVATED SNOW BANDS IN SOUTH
CENTRAL KS NORTHEASTWARD...SOME CHC THAT THEY MAY CLIP THE FAR
SOUTHERN CWA OVERNIGHT. BUT IF THEY DO...WILL BANK ON DRIER LLVLS
TO LIMIT THEM TO FLURRIES.
FRIDAY...ANOTHER COLD DAY CHARACTERIZED BY FILTERED SUNSHINE BY
OVERRUNNING CLOUDS OFF STORM SYSTEM JUST OFF TO THE SOUTHEAST.
MOSTLY CLOUDY CONDITIONS AND NORTHWEST WINDS OF 10-20 MPH IN
LINGERING RIDGE PRESSURE GRADIENT AS IT TRIES TO MAKE HEADWAY AND
SLIDE THIS WAY. AGAIN...WILL KEEP THE FCST DRY BUT WOULD NOT BE
SURPRISED IF SOME OVERRUNNING FLURRIES OR EVEN LIGHT SNOW
OCCASIONALLY CLIP THE FAR SOUTHERN AND SOUTHEASTERN CWA FROM TIME
TO TIME. CLOUD COVER AND CONTINUED CAA TO LIMIT HIGH TEMP RECOVERY
TO THE MID TEENS IN THE NORTHWEST...TO THE UPPER TEENS OR AROUND 20
DEGREES ALONG AND EAST OF THE MS RVR. ..12..
.LONG TERM...(FRIDAY NIGHT THROUGH NEXT THURSDAY)
ISSUED AT 318 PM CST THU DEC 5 2013
THE COLD WEATHER LOOKS LIKE IT WILL BE LOCKED IN OVER THE REGION
THROUGH MUCH OF NEXT WEEK WITH THE MODELS KEEPING A PERSISTENT BROAD
H5 TROF OVER THE CENTRAL AND WESTERN U.S.
DRY AND COLD CONDITIONS ARE EXPECTED SATURDAY AS HIGH PRESSURE MOVES
EAST ACROSS NORTHERN IA AND SOUTHERN MN. LOW TEMPERATURES IN THE
SINGLE DIGITS LOOK REASONABLE WITH LIGHT WINDS IN THE WEAK GRADIENT
NEAR THE HIGH AND CLEAR SKIES. LITTLE MIXING DURING THE DAY SUPPORT
TEENS AND LOW 20S FOR HIGHS.
A S/W MOVING OUT OF SOUTHWESTERN U.S. TROF AXIS WILL SPREAD MID
CLOUDS OVER THE AREA SUNDAY NIGHT. A FLURRY CAN/T BE RULED OUT WEST
OF THE RIVER AFTER MIDNIGHT WITH A BROAD REGION OF ISENTROPIC LIFT
AND MOISTENING MID LEVELS AHEAD OF THE S/W. HOWEVER...LOW LEVELS
REMAIN DRY WHICH SHOULD PREVENT ANY MEASURABLE SNOW. THE INCREASING
CLOUD COVER SATURDAY NIGHT WILL KEEP TEMPERATURES FROM FALLING MUCH
WITH LOWS AROUND 10 EXPECTED.
ACCUMULATING SNOW IS EXPECTED SUNDAY AND SUNDAY NIGHT AS THE S/W
MOVES THROUGH THE REGION. THE GFS/ECM HAVE BEEN VERY CONSISTENT
PAINTING A BROAD AREA OF QPF OVER THE REGION WITH THIS S/W WITH
WATER EQUIVALENTS UP TO TWO TENTHS OF AN INCH. THE ECMWF HAS ALSO
BEEN CONSISTENT IN KEEPING THE HIGHER AMOUNTS OVER THE NORTHERN CWFA
WHICH LOOKS REASONABLE BASED ON THE THE TRACK OF THE VORT THROUGH
NORTHERN MO/ SOUTHERN IA. TEMPERATURES WILL BE COLD ENOUGH FOR SOME
HIGH SNOW TO LIQUID RATIOS...POSSIBLY UP TO 20 TO 1 OVER THE
NORTHERN CWFA. FOR NOW A CONSERVATIVE 17 TO 1 RATIO WAS USED WHICH
PRODUCED 24 HOUR SNOWFALL AMOUNTS OF 2 TO NEARLY 4 INCHES OVER THE
NORTHWEST HALF OF THE AREA BETWEEN 12Z SUNDAY AND 12Z MONDAY.
FORECAST SNOW AMOUNTS OVER THE SOUTHEAST HALF WERE IN THE 1 TO 2
INCH RANGE. WIND DURING THE EVENT SHOULD STAY AROUND 10KTS OR LESS
SO NO SIGNIFICANT BLOWING OR DRIFTING IS EXPECTED. THE SNOW SHOULD BE
EAST OF THE AREA BY MONDAY MORNING.
ANOTHER SHOT OF VERY COLD AIR IS PULLED SOUTH INTO THE REGION BEHIND
SUNDAYS SYSTEM. H8 TEMPS ARE PROGGED TO DIP TO -15 TO -20C BY
TUESDAY NIGHT. HIGHS NEXT WEEK SHOULD BE IN THE TEENS AND 20S WITH
LOWS MAINLY IN THE SINGLE DIGITS AND TEENS. THE ECM CONTINUES TO
SHOW A STRONG HIGH PRESSURE SYSTEM OVER THE REGION BY MID WEEK WITH
THIS MORNINGS 12Z RUN INCREASING THE PRESSURE TO 1045MB. IF THIS
VERIFIES AND THERE IS SNOW COVER THEN WE COULD SEE LOW TEMPERATURES
SIGNIFICANTLY COLDER THAN CURRENTLY FORECAST FOR THE MIDDLE OF THE
WEEK. THE GFS ON THE OTHER HAND CONTINUES TO SUGGEST ONE OR TWO WEEK
CLIPPER SYSTEM MOVING THROUGH WHICH WOULD ARGUE AGAINST EXTREMELY
COLD TEMPERATURES. DLF
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1138 PM CST THU DEC 5 2013
PATCHY LOW CLOUDS WITH AN OCCASIONAL MVFR CIG ARE CURRENTLY BEING
FOUND OVER NORTHEAST IOWA. LATEST RAP MODEL OUTLIER WITH
INCREASING THE LOW CLOUDS AND ADVECTING SOUTHEAST OVER MUCH OF
AREA ESPECIALLY NORTH OF I-80 OVERNIGHT AND FRIDAY MORNING.
WHILE SOME PRESENCE OF LOW LEVEL THETA-E AXIS AND LOW LEVEL
FRONTOGENESIS COULD FOSTER ADDITIONAL LOW CLOUDS NOT VERY CONFIDENT
TO MENTION ANY CIGS... BUT DID MAINTAIN SCATTERED CLOUD BASES
AROUND 2KFT AGL ONLY AT KDBQ FOR NOW BEING CLOSER TO THE ABOVE
MENTIONED FEATURES. OTHERWISE...VFR CONDITIONS WITH MID/HIGH
CLOUDINESS FROM STORM SYSTEM PASSING TO OUR SOUTH ON FRIDAY. WINDS
WILL REMAIN GENERALLY NORTHWEST AROUND 10-15 KTS WITH SOME LOCALLY
HIGHER GUSTS POSSIBLE AT TIMES.
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SYNOPSIS...12
SHORT TERM...12
LONG TERM...DLF
AVIATION...05
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1207 AM CST Fri Dec 6 2013
...UPDATED AVIATION...
.SYNOPSIS...
ISSUED AT 1115 AM CST THU DEC 5 2013
At 12z Thursday a 1400-160kt 300mb jet extended from northeast
Colorado into the western Great Lakes. Another upper level jet was
located near the based of the 500mb trough that was positioned from
southern California into southwest Montana. A -25 to -32c 500mb
thermal trough was located near the four corners region. A surface
to 850mb ridge axis was located across from western Nebraska into
western Oklahoma and a surface cold front extended from eastern
Colorado south southeast across eastern New Mexico into west
central Texas.
&&
.SHORT TERM...(This evening through Friday)
ISSUED AT 217 PM CST THU DEC 5 2013
Upper level through that was located across southern California
and Nevada earlier today will track east and cross New Mexico by
late day. Ahead of this this upper trough some mid level moisture
will linger across western Kansas. Backing 700mb winds ahead of
this upper wave appears to enhance frontogenesis across portions
of southwest Kansas late today and early this evening which may
give rise to a period of steady light to moderate snow. Both the
NAM, GFS, and even the RAP hints at enhanced precipitation briefly
ahead of this wave along this baroclinic zone so will follow this
trend through midnight as the upper level trough moves out into
the central high plains. Given the potential for a period of
steadier snow early tonight could easily see snowfall
accumulations in the one to two inch range given the high liquid
to snow ratio. The area more favorable for this measurable
snowfall still appears to be along and south of a Ulysses to Dodge
City to Pratt line. Snow totals of around two inches still not out
of the question near the Oklahoma border so will trim several
counties out of the current winter weather advisory.
Tonight the dewpoint will be at or several degrees below zero
under mostly cloudy skies. Temperatures will be slow to fall this
evening but at this time given these expected low dewpoints, last
nights temperatures across northwest Kansas, and the low levels
cooling by a couple more degrees have decided to stay close to the
guidance for overnight lows. Given these overnight lows ranging
from around 1 degree in west central Kansas to near 10 degrees in
south central Kansas along with wind speeds of around 10 mph the
wind chills by early Friday morning are expected to fall back into
the -8 to -15 degree range. The coldest wind chills early Friday
morning will be across west central Kansas so will be issuing a
wind chill advisory for this area late tonight/early Friday.
On Friday the upper level trough will move east into the mid
Mississippi valley. Subsidence behind this disturbance may give
rise to some breaks of sun late in the day as high pressure at the
surface will continue to build into western Kansas. Despite to
break of sunshine the 900-850mb temperatures continue to support
highs only in the teens Friday afternoon.
.LONG TERM...(Friday night through Thursday)
ISSUED AT 209 PM CST THU DEC 5 2013
Friday night:
Sfc high pressure will shift off to the east Friday night. This will
result in northeasterly winds eventually shifting southeast on the backside
of said departing high. A cold night is expected with minimums near
0F. Would not rule out a few negative values if skies clear more than
expected. Will have to watch for the potential for a wind chill advisory
during the overnight and morning hours.
Saturday and beyond:
The forecast becomes a bit more interesting during the weekend. An amplified
trof will eject from the central Rockies and out across the plains by
Sunday. This wave does have some upper level dynamics associated with
it (140-150 kt jet streak traverses across the forecast area of responsibility).
At the low levels, fairly intense warm air advection, 280-290 Kelvin
isentropic lift, and 850-600 mb increasing frontogenesis will lead
to snow late Saturday and into Sunday. The more enhanced area of said
parameters is forecast along and north of the 850 mb pressure perturbation
...basically the northern half of the forecast area. Models still show
low end snow advisory amounts along and north of highway 96. Even some
of the GEFS members show 2-4" of snow. There is huge bust potential
in temperatures for Sunday, should this snow/snow pack/cloud cover come
into fruition. The ECE shows a high of 8 for KDDC versus 22 from the
MEX. Will apply a slight bias towards the ECMWF solution versus the
GFS. Boise verification shows this guidance doing better than the
MEX with the current cold air mass over Kansas.
After Sunday, the forecast will remain precipitation free as isentropic
downglide and subsidence develops in the wake of the departing synoptic
trof. There is some question of when this cold air will be dislodged
and more of a low level 850 mb downslope plume will develop. The ECMWF
indicates this possibility of seeing "warmer" temperatures (i.e. above
freezing) by mid to late next week. The deterministic runs have been
fairly consistent over the last few days.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1206 AM CST FRI DEC 6 2013
We will need to watch closely for any IFR ceiling development
into the early morning as the back edge of the mid level cloud
shield exits the region. Enough mid level cloud should remain
however to keep low stratus development to a minimum, but the HRRR
does hint at the possibility of localized IFR/LIFR stratus
development which is too low of a chance to include in prevailing
or tempo groups.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 15 0 16 8 / 0 0 30 40
GCK 15 0 13 7 / 0 0 30 50
EHA 13 1 17 9 / 0 0 30 40
LBL 15 0 15 8 / 0 0 30 40
HYS 15 0 15 6 / 0 0 40 60
P28 21 4 20 10 / 10 0 40 40
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY until 9 AM CST /8 AM MST/ this morning FOR
KSZ043-044-061>063.
&&
$$
SYNOPSIS...Burgert
SHORT TERM...Burgert
LONG TERM...Sugden
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1019 AM EST Fri Dec 6 2013
...Forecast Update...
Issued at 1010 AM EST Fri Dec 6 2013
Made some minor tweaks to the grids this morning to better define
sleet/freezing rain/plain rain areas. This didn`t result in any
major changes so our winter weather headlines will stay in the same
areas for now. However, the changes did give Butler/Nelson
counties a bit more freezing rain based on an ice glaze from
freezing rain already reported in Butler County this morning and
current sfc temp gradient orientation.
Overall, dual pol CC`s show the melting layer over southern Indiana
through Dubois, Orange, and Washington counties. Just got reports
of a change over from sleet to snow in NW Dubois County which
confirms that freezing level shown by dual pol data.
For the rest of the morning expect mainly sleet/freezing rain over
southern Indiana with a slow change over to all snow occurring from
the NW to SE. North central KY should largely be light freezing
rain with some areas near the Ohio River seeing some sleet by late
morning. The rain/freezing rain line as of 15Z was from roughly
Morgantown, KY to Frankfort, KY. Expect that line to slowing move
ESE through the day as well. Lexington/Bowling Green areas are
still looking to see a change over to freezing rain in the 2-4 pm
time frame.
Of note, with such warm ground temps ahead of this
weather system earlier this week, areas running in the 30-32 degree
range are seeing ice accums mainly on elevated sfcs. Road impacts
are more common where sfc temps are less than 30 degrees.
Issued at 635 AM EST Fri Dec 6 2013
Secondary surge of moisture is building across Missouri and Arkansas
this hour, and latest SPC mesoanalysis has another frontogenetical
band in the area where banding currently is setting up from KBMG to
KCGI. Latest HRRR is close to current thinking for snow numbers
across our region, 6-10" over our far northwest counties and 3-6"
along the river. The southern end of the warning still has freezing
rain to deal with. We have had a few glazing reports across the
current freezing rain area, which still includes KSDF, though the
intensity has slackened. No headline changes coming still, just
expect conditions to worsen later this morning into the afternoon.
Issued at 455 AM EST Fri Dec 6 2013
Active convection well to out south, and closer to the cold front,
appears to be stealing some of our thunder as far the winter precip
goes. Have a very apparent dry slot forming between this convection,
the northern edge of which now is over Lake Cumberland, and the
heavier sleet across southern Indiana. Even the latter band is
starting to wane as moisture is getting cut off from it. The GEM and
SREF both did a better job of handling this break in the precip, but
both fill that gap back in later this morning and into the
afternoon. Have adjusted totals and early pops to account for these
differences. The overall daytime forecast did not change much, so
will not issue a zone update and no changes to the headline products
are expected at this time.
.SHORT TERM (Now through Saturday Night)...
Issued at 330 AM EST Fri Dec 6 2013
...IMPACTFUL WINTER EVENT ONGOING...
Southwest feed of moisture is pumping in plenty of moisture and
working with Arctic air filtering into the region to create a messy
winter precip forecast this morning. Freezing rain line running
roughly from Russellville in Logan county to Etown/Louisville to
Frankfort. Had a band of heavier returns across our northern row of
counties, where sleet is coming down. SPC mesoanalysis earlier
showed a band of 850-700 mb frontogenesis where this band formed,
but that band has spread out now.
Timing for cold air continues to run a bit faster than previously
forecast, so have had to shift freezing rain timing south. Given
timing for precip coming in, that would also mean higher snow totals
over the north, where the deeper cold air will allow for a quicker
transition to snow during the day today. Bumped up the totals across
our northern counties to 6-10 inches, with areas right along the
Ohio River now getting between 2 and 6 inches.
Current headlines still look good. The northern part of the winter
storm warning looks solid for reaching the heavy snow criteria,
whereas the southern part looks like the combination of freezing
rain, sleet, and snow will be the main threat. The advisory area
looks in line for around an inch of snow and/or a tenth to a quarter
inch of freezing rain.
Moisture tap runs out aloft starts to run out this evening.
Soundings show we may have a period of freezing drizzle, as the top
of the saturated layer gets warmer than -10C. Given temperatures
falling quickly, this freezing drizzle combined with already wet
roadways and temperatures well into the 20s will make for continued
dangerous travel conditions overnight.
Highs Saturday will struggle to get into the lower 20s, if that
high, over southern Indiana in the snowpack. Down south, the
freezing mark will be the hard point to reach. The cold temperatures
will set the stage for the next system to come in, read on below.
.LONG TERM (Sunday through Friday)...
Issued at 320 AM EST Fri Dec 6 2013
...SIGNIFICANT WINTRY WEATHER EXPECTED LATE SATURDAY NIGHT AND
SUNDAY ACROSS THE REGION...
...Saturday night through Monday...
Ding, ding! Round two of wintry weather will commence late Saturday
night and through the day Sunday, as our next mid-level southern
stream wave heads northeastward. Precip may begin across southern
Kentucky around midnight, but models seem to rush it in after
midnight. Precipitation types are still a difficult forecast, which
depends on the final snow/sleet/ice totals from this first round of
wintry precip today.
Currently believe surface temperatures will be cold and the depth of
the cold airmass will be sufficiently deep to support mostly snow at
the precipitation onset. The snow could be particularly heavy early
Sunday across portions of southern Indiana and central Kentucky. As
the wave continues to move northeast, warmer air aloft would
eventually overspread the cold lower layer and result in a change
over to perhaps sleet for a very brief period, but freezing rain
would quickly take over and progress northward. Still too difficult
to pin down the snow and freezing rain amounts, but they could
accumulate rapidly before warmer surface air arrives.
Speaking of that, warmer air will work in at the surface across
southern Kentucky in the afternoon, changing freezing rain over to
rain. This too will continue northward into the evening as the wave
shifts northeast. In fact, the warmest temperatures Sunday may very
well occur in the evening as the warmer surface air gets in here. As
the wave departs, colder air rushes back in and will lead to any
leftover precipitation changing back over to snow before ending.
Highs Sunday look to warm to around the freezing mark in areas north
of the Ohio River late in the day, with mid to upper 30s across much
of Kentucky. Lows Sunday night will cool back into the lower 30s.
Highs on Monday are really tough because they will be so dependent
on snow/ice cover. Right now will go with highs in the lower 30s
across the northwest to lower 40s across the southeast.
Monday Night through Thursday...
Will keep a slight chance of light snow over far eastern and
southeastern counties Monday evening as broad shortwave aloft moves
through. Otherwise, weather during this period calms down as flow
aloft becomes less amplified with no noticeable weather systems to
track across our area. This period looks dry, even with a shortwave
trough diving through the Great Lakes Thursday. Any precip
associated with that trough appears to stay north of the area.
Temperatures will be the big story. It will be quite cold with highs
in the 20s across the north and 30s across the south Tuesday through
Thursday, with lows generally in the single digits across the north
and teens across the southern CWA. As mentioned in the previous
forecast, whatever snow cover exists in our north will affect these
numbers.
&&
.HYDROLOGY...
Issued at 315 PM EDT Thu Dec 5 2013
A prolonged period of precipitation will continue into the weekend.
The first system has already dumped up to an inch and another 1 to 2
inches are expected before the precipitation ends Friday night. The
northern portions will see much of this precipitation change over to
freezing or frozen forms. Thus, rises will occur on rivers and
streams but no flooding on major rivers is expected. However,
localized flooding could still occur tonight into Friday.
The second system Saturday night through Sunday could drop an
additional 1 to 2 inches of precipitation is expected over southeast
Kentucky. Again, the precipitation will be a mixture of frozen and
freezing types and will runoff slower than pure rain. This next shot
could trigger some minor flooding on parts of the Green, Licking,
and Salt basins. If so, flooding will extend into next week.
&&
.AVIATION (12Z TAF Update)...
Updated at 640 AM EST Fri Dec 6 2013
There is a bit of a lull in precipitation occurring across the
region as moisture aloft has diminished a bit. This is leading to or
will lead to more of a freezing drizzle and very light sleet
situation for a few hours this morning rather than the steadier
rain. However, our next wave is just southwest of the area and deep
moisture will quickly spread across the region once again.
Precipitation intensity will increase and as the temperature profile
continues to cool, precip type will change through the day. Expect
precip to end this evening and overnight in the form of light
freezing drizzle/light sleet as we once again lose the upper-level
moisture with the system departing. Expect IFR ceilings will be
common now and through the evening before starting to transition to
MVFR toward the end of the TAF period. Visibilities will also
decrease in the heavier precip later today. Winds will continue to
be out of the north at 9-14 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...WINTER STORM WARNING until 1 AM EST /Midnight CST/ Saturday FOR
KYZ023>038.
WINTER WEATHER ADVISORY until 1 AM EST /Midnight CST/ Saturday
FOR KYZ039>043-045>049-053>055-061>063-070>072.
IN...WINTER STORM WARNING until 1 AM EST /Midnight CST/ Saturday FOR
INZ076>079-083-084-089>092.
&&
$$
Update.........AMS
Short Term.....RJS
Long Term......MJP
Hydrology......CMC
Aviation.......RJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
641 AM EST Fri Dec 6 2013
...Updated Aviation and Forecast Discussion...
...Forecast Update...
Issued at 635 AM EST Fri Dec 6 2013
Secondary surge of moisture is building across Missouri and Arkansas
this hour, and latest SPC mesoanalysis has another frontogenetical
band in the area where banding currently is setting up from KBMG to
KCGI. Latest HRRR is close to current thinking for snow numbers
across our region, 6-10" over our far northwest counties and 3-6"
along the river. The southern end of the warning still has freezing
rain to deal with. We have had a few glazing reports across the
current freezing rain area, which still includes KSDF, though the
intensity has slackened. No headline changes coming still, just
expect conditions to worsen later this morning into the afternoon.
Issued at 455 AM EST Fri Dec 6 2013
Active convection well to out south, and closer to the cold front,
appears to be stealing some of our thunder as far the winter precip
goes. Have a very apparent dry slot forming between this convection,
the northern edge of which now is over Lake Cumberland, and the
heavier sleet across southern Indiana. Even the latter band is
starting to wane as moisture is getting cut off from it. The GEM and
SREF both did a better job of handling this break in the precip, but
both fill that gap back in later this morning and into the
afternoon. Have adjusted totals and early pops to account for these
differences. The overall daytime forecast did not change much, so
will not issue a zone update and no changes to the headline products
are expected at this time.
.SHORT TERM (Now through Saturday Night)...
Issued at 330 AM EST Fri Dec 6 2013
...IMPACTFUL WINTER EVENT ONGOING...
Southwest feed of moisture is pumping in plenty of moisture and
working with Arctic air filtering into the region to create a messy
winter precip forecast this morning. Freezing rain line running
roughly from Russellville in Logan county to Etown/Louisville to
Frankfort. Had a band of heavier returns across our northern row of
counties, where sleet is coming down. SPC mesoanalysis earlier
showed a band of 850-700 mb frontogenesis where this band formed,
but that band has spread out now.
Timing for cold air continues to run a bit faster than previously
forecast, so have had to shift freezing rain timing south. Given
timing for precip coming in, that would also mean higher snow totals
over the north, where the deeper cold air will allow for a quicker
transition to snow during the day today. Bumped up the totals across
our northern counties to 6-10 inches, with areas right along the
Ohio River now getting between 2 and 6 inches.
Current headlines still look good. The northern part of the winter
storm warning looks solid for reaching the heavy snow criteria,
whereas the southern part looks like the combination of freezing
rain, sleet, and snow will be the main threat. The advisory area
looks in line for around an inch of snow and/or a tenth to a quarter
inch of freezing rain.
Moisture tap runs out aloft starts to run out this evening.
Soundings show we may have a period of freezing drizzle, as the top
of the saturated layer gets warmer than -10C. Given temperatures
falling quickly, this freezing drizzle combined with already wet
roadways and temperatures well into the 20s will make for continued
dangerous travel conditions overnight.
Highs Saturday will struggle to get into the lower 20s, if that
high, over southern Indiana in the snowpack. Down south, the
freezing mark will be the hard point to reach. The cold temperatures
will set the stage for the next system to come in, read on below.
.LONG TERM (Sunday through Friday)...
Issued at 320 AM EST Fri Dec 6 2013
...SIGNIFICANT WINTRY WEATHER EXPECTED LATE SATURDAY NIGHT AND
SUNDAY ACROSS THE REGION...
...Saturday night through Monday...
Ding, ding! Round two of wintry weather will commence late Saturday
night and through the day Sunday, as our next mid-level southern
stream wave heads northeastward. Precip may begin across southern
Kentucky around midnight, but models seem to rush it in after
midnight. Precipitation types are still a difficult forecast, which
depends on the final snow/sleet/ice totals from this first round of
wintry precip today.
Currently believe surface temperatures will be cold and the depth of
the cold airmass will be sufficiently deep to support mostly snow at
the precipitation onset. The snow could be particularly heavy early
Sunday across portions of southern Indiana and central Kentucky. As
the wave continues to move northeast, warmer air aloft would
eventually overspread the cold lower layer and result in a change
over to perhaps sleet for a very brief period, but freezing rain
would quickly take over and progress northward. Still too difficult
to pin down the snow and freezing rain amounts, but they could
accumulate rapidly before warmer surface air arrives.
Speaking of that, warmer air will work in at the surface across
southern Kentucky in the afternoon, changing freezing rain over to
rain. This too will continue northward into the evening as the wave
shifts northeast. In fact, the warmest temperatures Sunday may very
well occur in the evening as the warmer surface air gets in here. As
the wave departs, colder air rushes back in and will lead to any
leftover precipitation changing back over to snow before ending.
Highs Sunday look to warm to around the freezing mark in areas north
of the Ohio River late in the day, with mid to upper 30s across much
of Kentucky. Lows Sunday night will cool back into the lower 30s.
Highs on Monday are really tough because they will be so dependent
on snow/ice cover. Right now will go with highs in the lower 30s
across the northwest to lower 40s across the southeast.
Monday Night through Thursday...
Will keep a slight chance of light snow over far eastern and
southeastern counties Monday evening as broad shortwave aloft moves
through. Otherwise, weather during this period calms down as flow
aloft becomes less amplified with no noticeable weather systems to
track across our area. This period looks dry, even with a shortwave
trough diving through the Great Lakes Thursday. Any precip
associated with that trough appears to stay north of the area.
Temperatures will be the big story. It will be quite cold with highs
in the 20s across the north and 30s across the south Tuesday through
Thursday, with lows generally in the single digits across the north
and teens across the southern CWA. As mentioned in the previous
forecast, whatever snow cover exists in our north will affect these
numbers.
&&
.HYDROLOGY...
Issued at 315 PM EDT Thu Dec 5 2013
A prolonged period of precipitation will continue into the weekend.
The first system has already dumped up to an inch and another 1 to 2
inches are expected before the precipitation ends Friday night. The
northern portions will see much of this precipitation change over to
freezing or frozen forms. Thus, rises will occur on rivers and
streams but no flooding on major rivers is expected. However,
localized flooding could still occur tonight into Friday.
The second system Saturday night through Sunday could drop an
additional 1 to 2 inches of precipitation is expected over southeast
Kentucky. Again, the precipitation will be a mixture of frozen and
freezing types and will runoff slower than pure rain. This next shot
could trigger some minor flooding on parts of the Green, Licking,
and Salt basins. If so, flooding will extend into next week.
&&
.AVIATION (12Z TAF Update)...
Updated at 640 AM EST Fri Dec 6 2013
There is a bit of a lull in precipitation occurring across the
region as moisture aloft has diminished a bit. This is leading to or
will lead to more of a freezing drizzle and very light sleet
situation for a few hours this morning rather than the steadier
rain. However, our next wave is just southwest of the area and deep
moisture will quickly spread across the region once again.
Precipitation intensity will increase and as the temperature profile
continues to cool, precip type will change through the day. Expect
precip to end this evening and overnight in the form of light
freezing drizzle/light sleet as we once again lose the upper-level
moisture with the system departing. Expect IFR ceilings will be
common now and through the evening before starting to transition to
MVFR toward the end of the TAF period. Visibilities will also
decrease in the heavier precip later today. Winds will continue to
be out of the north at 9-14 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...WINTER STORM WARNING until 1 AM EST /Midnight CST/ Saturday FOR
KYZ023>038.
WINTER WEATHER ADVISORY until 1 AM EST /Midnight CST/ Saturday
FOR KYZ039>043-045>049-053>055-061>063-070>072.
IN...WINTER STORM WARNING until 1 AM EST /Midnight CST/ Saturday FOR
INZ076>079-083-084-089>092.
&&
$$
Update.........RJS
Short Term.....RJS
Long Term......MJP
Hydrology......CMC
Aviation.......MJP
AREA FORECAST DISCUSSION...UPDATED
NWS PADUCAH KY
1127 PM CST Thu Dec 5 2013
.UPDATE...
ISSUED AT 1118 PM CST THU DEC 5 2013
Updated the aviation discussion for the 06Z TAF issuance.
UPDATE ISSUED AT 815 PM CST THU DEC 5 2013
Currently making only minor adjustments to snow/sleet locations in
the grids. There are some slight differences between the latest
NAM and RAP soundings with the NAM a tad warmer. Will keep the mix
but move the snow line a bit farther south. Will up snow amounts
in some areas as Du Quoin is already measuring 2 inches.
Over SEMO now getting reports of sleet. CC product from radar
indicating a mix of snow with bursts of sleet. Expect that to
continue for a good portion of the night except for the extreme
southeast 3 or 4 counties where there might be more icing.
There is currently a lull over west Kentucky but we expect this to
fill in slowly as precipitation is increasing to our south. The
RAP and NAM models keeps a general lull over west Kentucky
through about 9z. Models seem to be hinting at the increase in
intensity over the entire area around midday tomorrow.
&&
.SHORT TERM...(This Evening through Saturday)
ISSUED AT 331 PM CST THU DEC 5 2013
The winter storm is a couple of hours earlier than expected, but
the overall evolution has been as expected so far. The
precipitation has quickly transitioned to sleet over much of
southeast Missouri and southern Illinois. Will allow the warning
to continue as is.
The main shift in guidance, led by the 12Z NAM is to hang onto a
very warm layer aloft longer into the event. The southeast corner
of the area may never see much in the way of snow before the
precipitation ends. The forecast has been shift a bit more toward
freezing rain/ice and less sleet and snow over much of west
Kentucky and Missouri Boot Heel region. A half inch of ice is
likely over much of this area, with just an inch or two of sleet
and snow. Over the northern portions of the area the 6-8" swath of
sleet and snow still looks good, and may not be high enough given
some sleet accumulations we have already received this afternoon.
The overall timing remains the same with the precipitation coming
to a rapid end from west to east Friday afternoon.
North winds generally 10 to 15 mph will continue to bring in much
cooler air through the short term period. Single digit temperatures
are expected over much of the area Friday night, and negative wind
chills are now forecast over much of the area Friday night as
well.
.LONG TERM...(Saturday Night through Thursday)
ISSUED AT 331 PM CST THU DEC 5 2013
Models continue to show low pressure over the western Gulf of Mexico
12z Sunday, with an inverted trof extending east of the PAH forecast
area. Models continue to trend a little farther east, which would
lessen amounts across our area. However, this will also keep our
region in colder air, thus indicating a more persistent wintry mix
and less potential for our southeast counties, where the highest QPF
should be, to change to rain on Sunday. Precipitation will spread
northwest across our counties late Saturday night and continue
through the day Sunday. Light amounts of snow, sleet and a little
freezing rain will be possible across southeast Missouri, southern
Illinois and southwest Indiana by the time the precipitation ends
late Sunday afternoon or Sunday evening.
Across west Kentucky, and possibly into extreme southeast Missouri
and extreme southern Illinois, more significant amounts of freezing
rain and sleet are possible. With almost all of the region below
freezing through the entire event, whatever falls will freeze and/or
accumulate. Southern portions of the Pennyrile region of west
Kentucky have the best chance for temperatures to climb above
freezing, but with the best QPF in this area, a tenth to a quarter
inch of ice accumulation will be possible before the temperatures
potentially climb to above freezing. Lesser amounts of ice are
expected across the rest of west Kentucky and adjacent areas.
Overall confidence is not very high right now, due to current models
trends, but fortunately amounts have trended downward from a couple
of days ago. If the GFS pans out, amounts would still be pretty
significant, but ECMWF, NAM and GEM all show higher QPF mainly over
portions of west Kentucky or to our east. Also, how much snow/ice
pack is left from the winter event just getting started across our
region will have an impact on temperatures and potential
accumulations. By late Sunday night the wintry precip, mainly snow
and sleet by that point, should gradually taper off from west to
east, with a return of dry conditions after 12z Monday.
High pressure will build across the Central Plains Monday and slowly
slide east through mid week, centered over the middle Mississippi
valley by 12z Wednesday. Very cold air will settle into our region
for the early part of the work week. Highs Monday will range from
the middle 20s north to the lower 30s south, then only in the 20s
area wide Tuesday. Lows both Monday night and Tuesday night will
range from the middle single digits north to the middle teens
southeast. By Wednesday and Thursday, with plenty of sunshine, high
temperatures will rebound a little, back into the middle 20s to
middle 30s.
&&
.AVIATION...
ISSUED AT 1118 PM CST THU DEC 5 2013
Cigs and/or vsbys at all sites will gradually decrease from MVFR
to IFR by mid period, then back to MVFR toward the end of the
cycle. Snow/sleet at KCGI should change over to all snow around
15Z. Freezing rain/sleet at KPAH/KEVV/KOWB should change over to
snow between 15-18Z. Northerly winds 10-15 mph gusting up to 20
mph should subside somewhat by the end of the period.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING until 6 PM CST Friday FOR ILZ075>078-
080>094.
MO...WINTER STORM WARNING until 6 PM CST Friday FOR MOZ076-086-087-
100-107>112-114.
IN...WINTER STORM WARNING until 6 PM CST Friday FOR INZ081-082-
085>088.
KY...WINTER STORM WARNING until 6 PM CST Friday FOR KYZ001>008-010-
011-013>016-018>020.
WINTER STORM WARNING until 9 PM CST Friday FOR KYZ009-012-017-
021-022.
&&
$$
SHORT TERM...PS
AVIATION...JP
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1206 PM CST FRI DEC 6 2013
.AVIATION...THE LEADING EDGE OF THE SHALLOW COLD WEDGE OF A COLD
FRONT IS JUST BEYOND TERMINAL ARA WITH VLIFR CIGS, DRIZZLE AND FOG
EXTENDING BACK INTO ARA AND LFT. TO THE WEST, IFR CIGS WITH A FEW SHOWERS
AROUND LCH. PRECIP MORE EXTENSIVE TO THE NORTH AROUND AEX WHERE
LIFR CIGS COMBINE WITH VIS CURRENTLY LESS THAN 2 MILES IN A
MODERATE BAND OF RAIN AND DRIZZLE WILL SHORTLY BE MOVING EAST WITH
VIS TO 3 MILES IMPROVING TO 6 MILES WHILE LIFR CIGS PERSIST THIS AFTERNOON.
ALL LOCATIONS SHOULD SEE PRECIP ENDING WITH MVFR CIGS AND GUSTY
WINDS THIS EVENING WITH THE EXCEPTION OF ARA WHERE IFR CIGS SHOULD
CONTINUE. A FEW SHOWERS COULD REAPPEAR SATURDAY MORNING AS
ADDITIONAL MOISTURE MOVES IN ALOFT AS A FRONTAL WAVE DEVELOPS NEAR
THE TEXAS COAST.
SWEENEY
&&
.PREV DISCUSSION... /ISSUED 1116 AM CST FRI DEC 6 2013/
DISCUSSION...
CDFNT FAIRLY EVIDENT ON VISIBLE SATELLITE AND RADAR IMAGERY
EXTENDING FROM SOUTH CENTRAL LOUISIANA INTO THE WESTERN
GULF...WITH AN EXTENSIVE BLANKET OF POST FRONTAL STRATUS NOW
COVERING ALL BUT EXTREME SE INLAND ZONES AND THE SE THIRD OR SO OF
THE MAOR. DRIZZLE...ALONG WITH PATCHES OF MODERATE RAIN AND A FEW
SHOWERS...PREVAIL IN THE COLD POST FRONTAL AIRMASS. COVERAGE HAS
INCREASED OVER THE PAST COUPLE OF HOURS OR SO...AND THIS SHOULD
CONTINUE HEADING INTO THE EARLY TO MID AFTERNOON...WITH RAIN
CHANCES STARTING TO DECLINE HEADING FROM LATE AFTERNOON THROUGH
THE EVENING. WITH THE EXCEPTION OF LOCATIONS AHEAD OF THE FRONT
WHERE WARMING IS ONGOING...TEMPERATURES ARE EXPECTED TO REMAIN
STEADY IF NOT FALL SLOWLY THROUGH THE DAY. THE CONTRAST IS
STRIKING...WITH LATEST OBS FROM LAFAYETTE AND PATTERSON REPORTING
49 AND 79 DEGREES RESPECTIVELY. ACCURATELY DEPICTING THIS
PHENOMENON IN THE GRIDS IS QUITE CHALLENGING...BUT GENERALLY
SPEAKING...LATEST RUC FCSTS APPEAR TO HAVE THE GREATEST GRASP ON
OVERALL SHORT TERM TRENDS...AND THUS WAS RELIED ON HEAVILY FOR
THE HRLY FCST THE REST OF TODAY. DID INCLUDE SOME PATCHY FOG OVER
SOUTH CENTRAL LOUISIANA WHERE KLFT AND KARA HAVE REPORTED 1/2SM OR
LESS AT TIMES THIS MORNING. THIS SHOULD IMPROVE HEADING INTO THE
AFTERNOON...BUT WILL CONTINUE TO MONITOR TRENDS AND MAY HAVE TO
ADD IT FOR THIS AFTERNOON/EVENING FOR AREAS STILL DOWNSTREAM OF
THE FRONT. HAVE NOT LOOKED TOO DEEPLY AT TONIGHT JUST YET...BUT A
QUICK GLANCE REVEALS THE TYPICAL CAVEATS WHICH INCLUDE BORDERLINE
FREEZING TEMPERATURES AND WHETHER ANY PCPN WILL BE ONGOING TO
FREEZE. WILL BE EXAMINING THAT FURTHER FOR THE AFTERNOON PACKAGE.
13
PREV DISCUSSION... /ISSUED 531 AM CST FRI DEC 6 2013/
DISCUSSION...
12Z TAF ISSUANCE.
AVIATION...
COLD FRONT NOW ACROSS LOWER ACADIANA...PAST ARA BUT NOT YET
REACHED PTN. RADAR SHOWS SCT OVERRUNNING SHRA OVER SE TX/C AND SC
LA THIS MORNING...MIXED WITH -DZ NOT DETECTED BY RADAR.
OTHERWISE...LIFR CEILINGS WILL CONTINUE THIS MORNING FOR ALL
SITES...WITH INTERMITTENT IFR VSBY POSSIBLE AS WELL. SHRA EXPECTED
TO INCREASE LATER THIS MORNING INTO THE EARLY AFTERNOON HOURS. CEILINGS
ONLY EXPECTED TO IMPROVE TO IFR AT BEST LATER THIS MORNING INTO
THE AFTERNOON...WITH IMPROVEMENT TO MVFR THIS EVENING.
DML
PREV DISCUSSION... /ISSUED 355 AM CST FRI DEC 6 2013/
DISCUSSION...
SFC ANALYSIS/88D IMAGERY SHOWS THE FRONT RUNNING ROUGHLY FROM KBTR
THROUGH KLFT AND KIYA TO THE COASTAL WATERS SOUTH OF CAMERON.
LOCAL 88DS SHOW SCATTERED LIGHT SHOWERS DEVELOPING MAINLY ALONG
THE FRONT AND PATCHY LIGHT RAIN BEGINNING TO DEVELOP OVER THE NWRN
ZONES. FURTHER NORTH...REGIONAL 88DS SHOW A LARGE AREA OF LIGHT
RAIN...WITH SOME FREEZING RAIN MIXED IN...SPREADING ACROSS NRN TX
INTO THE ARKLATEX.
NO SIGNIFICANT CHANGES WERE MADE TO THE INHERITED GRIDS/ZONES THIS
MORNING. 00Z MODEL RUNS INDICATE THE PRECIP SHIELD TO OUR NW WILL
CONTINUE PUSHING ESEWD THROUGH THE DAY...MOST AFFECTING THE NRN
ZONES WHERE HIGHEST POPS ARE CURRENTLY DISPLAYED. MEANWHILE
ADDITIONAL OVERRUNNING-TYPE RAINS ARE EXPECTED TO DEVELOP ACROSS
THE REMAINDER OF THE FORECAST AREA AS THE FRONT GRADUALLY GETS A
SHOVE FROM FROM THE SHORTWAVE MOVING INTO THE TX BIG BEND REGION
AND FINALLY DEPARTS THE SERN ZONES LATER THIS MORNING. AS COLD AIR
ASSOCIATED WITH BUILDING CANADIAN HIGH PRESSURE WORKS ITS WAY
OVER THE AREA THROUGH TODAY TEMPS ARE EXPECTED TO BASICALLY HOLD
IN THE LOWER 40S ACROSS THE NWRN ZONES.
STILL LOOKING AT THE POSSIBILITY OF WINTRY WEATHER LATE TONIGHT
INTO SATURDAY MORNING ACROSS THE NRN TIER OF ZONES AS FORECAST
SOUNDINGS CONTINUE TO INDICATE A SHALLOW SUBFREEZING LAYER NEAR THE
SFC. STILL NOT SEEING THE NEED TO EXPAND THIS AREA OF FREEZING
PRECIP SWD THOUGH AS FORECAST SOUNDINGS CONTINUE TO SHOW TEMPS
STAYING ABOVE 32F FOR NOW.
A FAIRLY MESSY WEATHER PATTERN LOOKS ON TAP FOR THE WEEKEND AS THE
OVERRUNNING PATTERN LINGERS AND GETS AIDED BY SFC LOW DEVELOPMENT
OVER THE WRN GULF. THE PRECIP SHOULD GRADUALLY DIMINISH INTO
EARLY NEXT WEEK WHEN THE LONGWAVE TROF AXIS PUSHES EWD ACROSS THE
CNTL CONUS AND DRY AIR TAKES OVER THROUGH THE COLUMN. THE CANADIAN
AIRMASS PROGGED TO SLIP SWD ACROSS THE WRN/CNTL CONUS WILL
MAINTAIN COOL TEMPS THROUGH MID-WEEK. RAIN CHANCES RETURN VERY
LATE IN THE FORECAST PERIOD AS A STRONG SHORTWAVE CROSSES THE
REGION AND WORKS IN CONCERT WITH PROGGED COASTAL TROF DEVELOPMENT.
MARINE...
EXTENDED THE DENSE FOG ADVISORY FOR VERMILION BAY/NEAR SHORE
WATERS EAST OF INTRACOASTAL CITY TO 15Z AS VERY LOW VISIBILITIES
WILL REMAIN A THREAT UNTIL THE FRONT PASSES THIS AREA. ALSO ADDED
CAUTION HEADLINES TO SABINE/CALCASIEU LAKES FOR THIS AFTERNOON AS
NRLY WINDS ARE EXPECTED TO INCREASE TO THE 15-20 KNOT RANGE.
OTHERWISE SCA CONDITIONS ARE EXPECTED TO DEVELOP THROUGH THE
AFTERNOON AND EVENING ON THE COASTAL WATERS AS STRONG OFFSHORE
DEVELOPS IN WAKE OF THE FRONT.
08
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 50 36 43 35 49 / 70 30 50 40 50
KBPT 47 36 44 35 46 / 60 30 50 40 50
KAEX 43 32 41 34 43 / 90 30 50 50 60
KLFT 50 36 44 38 54 / 70 30 50 40 60
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 6 PM CST
SATURDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA OUT 20 NM...
WATERS FROM LOWER ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA
FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SATURDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM CAMERON LA TO HIGH ISLAND TX OUT
20 NM...WATERS FROM CAMERON LA TO HIGH ISLAND TX FROM 20 TO
60 NM.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SATURDAY FOR THE FOLLOWING
ZONES: COASTAL WATERS FROM INTRACOASTAL CITY TO CAMERON LA
OUT 20 NM...WATERS FROM INTRACOASTAL CITY TO CAMERON LA
FROM 20 TO 60 NM.
SMALL CRAFT EXERCISE CAUTION THROUGH SATURDAY AFTERNOON FOR THE
FOLLOWING ZONES: SABINE LAKE.
SMALL CRAFT EXERCISE CAUTION THROUGH SATURDAY AFTERNOON FOR THE
FOLLOWING ZONES: CALCASIEU LAKE.
SMALL CRAFT EXERCISE CAUTION FROM 3 PM CST THIS AFTERNOON
THROUGH SATURDAY AFTERNOON FOR THE FOLLOWING ZONES:
VERMILION BAY.
&&
$$
AREA FORECAST DISCUSSION
NWS LAKE CHARLES LA
1116 AM CST FRI DEC 6 2013
.DISCUSSION...
CDFNT FAIRLY EVIDENT ON VISIBLE SATELLITE AND RADAR IMAGERY
EXTENDING FROM SOUTH CENTRAL LOUISIANA INTO THE WESTERN
GULF...WITH AN EXTENSIVE BLANKET OF POST FRONTAL STRATUS NOW
COVERING ALL BUT EXTREME SE INLAND ZONES AND THE SE THIRD OR SO OF
THE MAOR. DRIZZLE...ALONG WITH PATCHES OF MODERATE RAIN AND A FEW
SHOWERS...PREVAIL IN THE COLD POST FRONTAL AIRMASS. COVERAGE HAS
INCREASED OVER THE PAST COUPLE OF HOURS OR SO...AND THIS SHOULD
CONTINUE HEADING INTO THE EARLY TO MID AFTERNOON...WITH RAIN
CHANCES STARTING TO DECLINE HEADING FROM LATE AFTERNOON THROUGH
THE EVENING. WITH THE EXCEPTION OF LOCATIONS AHEAD OF THE FRONT
WHERE WARMING IS ONGOING...TEMPERATURES ARE EXPECTED TO REMAIN
STEADY IF NOT FALL SLOWLY THROUGH THE DAY. THE CONTRAST IS
STRIKING...WITH LATEST OBS FROM LAFAYETTE AND PATTERSON REPORTING
49 AND 79 DEGREES RESPECTIVELY. ACCURATELY DEPICTING THIS
PHENOMENON IN THE GRIDS IS QUITE CHALLENGING...BUT GENERALLY
SPEAKING...LATEST RUC FCSTS APPEAR TO HAVE THE GREATEST GRASP ON
OVERALL SHORT TERM TRENDS...AND THUS WAS RELIED ON HEAVILY FOR
THE HRLY FCST THE REST OF TODAY. DID INCLUDE SOME PATCHY FOG OVER
SOUTH CENTRAL LOUISIANA WHERE KLFT AND KARA HAVE REPORTED 1/2SM OR
LESS AT TIMES THIS MORNING. THIS SHOULD IMPROVE HEADING INTO THE
AFTERNOON...BUT WILL CONTINUE TO MONITOR TRENDS AND MAY HAVE TO
ADD IT FOR THIS AFTERNOON/EVENING FOR AREAS STILL DOWNSTREAM OF
THE FRONT. HAVE NOT LOOKED TOO DEEPLY AT TONIGHT JUST YET...BUT A
QUICK GLANCE REVEALS THE TYPICAL CAVEATS WHICH INCLUDE BORDERLINE
FREEZING TEMPERATURES AND WHETHER ANY PCPN WILL BE ONGOING TO
FREEZE. WILL BE EXAMINING THAT FURTHER FOR THE AFTERNOON PACKAGE.
13
&&
.PREV DISCUSSION... /ISSUED 531 AM CST FRI DEC 6 2013/
DISCUSSION...
12Z TAF ISSUANCE.
AVIATION...
COLD FRONT NOW ACROSS LOWER ACADIANA...PAST ARA BUT NOT YET
REACHED PTN. RADAR SHOWS SCT OVERRUNNING SHRA OVER SE TX/C AND SC
LA THIS MORNING...MIXED WITH -DZ NOT DETECTED BY RADAR.
OTHERWISE...LIFR CEILINGS WILL CONTINUE THIS MORNING FOR ALL
SITES...WITH INTERMITTENT IFR VSBY POSSIBLE AS WELL. SHRA EXPECTED
TO INCREASE LATER THIS MORNING INTO THE EARLY AFTERNOON HOURS. CEILINGS
ONLY EXPECTED TO IMPROVE TO IFR AT BEST LATER THIS MORNING INTO
THE AFTERNOON...WITH IMPROVEMENT TO MVFR THIS EVENING.
DML
PREV DISCUSSION... /ISSUED 355 AM CST FRI DEC 6 2013/
DISCUSSION...
SFC ANALYSIS/88D IMAGERY SHOWS THE FRONT RUNNING ROUGHLY FROM KBTR
THROUGH KLFT AND KIYA TO THE COASTAL WATERS SOUTH OF CAMERON.
LOCAL 88DS SHOW SCATTERED LIGHT SHOWERS DEVELOPING MAINLY ALONG
THE FRONT AND PATCHY LIGHT RAIN BEGINNING TO DEVELOP OVER THE NWRN
ZONES. FURTHER NORTH...REGIONAL 88DS SHOW A LARGE AREA OF LIGHT
RAIN...WITH SOME FREEZING RAIN MIXED IN...SPREADING ACROSS NRN TX
INTO THE ARKLATEX.
NO SIGNIFICANT CHANGES WERE MADE TO THE INHERITED GRIDS/ZONES THIS
MORNING. 00Z MODEL RUNS INDICATE THE PRECIP SHIELD TO OUR NW WILL
CONTINUE PUSHING ESEWD THROUGH THE DAY...MOST AFFECTING THE NRN
ZONES WHERE HIGHEST POPS ARE CURRENTLY DISPLAYED. MEANWHILE
ADDITIONAL OVERRUNNING-TYPE RAINS ARE EXPECTED TO DEVELOP ACROSS
THE REMAINDER OF THE FORECAST AREA AS THE FRONT GRADUALLY GETS A
SHOVE FROM FROM THE SHORTWAVE MOVING INTO THE TX BIG BEND REGION
AND FINALLY DEPARTS THE SERN ZONES LATER THIS MORNING. AS COLD AIR
ASSOCIATED WITH BUILDING CANADIAN HIGH PRESSURE WORKS ITS WAY
OVER THE AREA THROUGH TODAY TEMPS ARE EXPECTED TO BASICALLY HOLD
IN THE LOWER 40S ACROSS THE NWRN ZONES.
STILL LOOKING AT THE POSSIBILITY OF WINTRY WEATHER LATE TONIGHT
INTO SATURDAY MORNING ACROSS THE NRN TIER OF ZONES AS FORECAST
SOUNDINGS CONTINUE TO INDICATE A SHALLOW SUBFREEZING LAYER NEAR THE
SFC. STILL NOT SEEING THE NEED TO EXPAND THIS AREA OF FREEZING
PRECIP SWD THOUGH AS FORECAST SOUNDINGS CONTINUE TO SHOW TEMPS
STAYING ABOVE 32F FOR NOW.
A FAIRLY MESSY WEATHER PATTERN LOOKS ON TAP FOR THE WEEKEND AS THE
OVERRUNNING PATTERN LINGERS AND GETS AIDED BY SFC LOW DEVELOPMENT
OVER THE WRN GULF. THE PRECIP SHOULD GRADUALLY DIMINISH INTO
EARLY NEXT WEEK WHEN THE LONGWAVE TROF AXIS PUSHES EWD ACROSS THE
CNTL CONUS AND DRY AIR TAKES OVER THROUGH THE COLUMN. THE CANADIAN
AIRMASS PROGGED TO SLIP SWD ACROSS THE WRN/CNTL CONUS WILL
MAINTAIN COOL TEMPS THROUGH MID-WEEK. RAIN CHANCES RETURN VERY
LATE IN THE FORECAST PERIOD AS A STRONG SHORTWAVE CROSSES THE
REGION AND WORKS IN CONCERT WITH PROGGED COASTAL TROF DEVELOPMENT.
MARINE...
EXTENDED THE DENSE FOG ADVISORY FOR VERMILION BAY/NEAR SHORE
WATERS EAST OF INTRACOASTAL CITY TO 15Z AS VERY LOW VISIBILITIES
WILL REMAIN A THREAT UNTIL THE FRONT PASSES THIS AREA. ALSO ADDED
CAUTION HEADLINES TO SABINE/CALCASIEU LAKES FOR THIS AFTERNOON AS
NRLY WINDS ARE EXPECTED TO INCREASE TO THE 15-20 KNOT RANGE.
OTHERWISE SCA CONDITIONS ARE EXPECTED TO DEVELOP THROUGH THE
AFTERNOON AND EVENING ON THE COASTAL WATERS AS STRONG OFFSHORE
DEVELOPS IN WAKE OF THE FRONT.
&&
.PRELIMINARY POINT TEMPS/POPS...
KLCH 50 36 43 35 / 70 30 50 40
KBPT 47 36 44 35 / 60 30 50 40
KAEX 43 32 41 34 / 90 30 50 50
KLFT 50 36 44 38 / 70 30 50 40
&&
.LCH WATCHES/WARNINGS/ADVISORIES...
LA...NONE.
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 3 PM THIS AFTERNOON TO 6 PM CST
SATURDAY FOR COASTAL WATERS FROM LOWER ATCHAFALAYA RIVER TO
INTRACOASTAL CITY LA OUT 20 NM-WATERS FROM LOWER
ATCHAFALAYA RIVER TO INTRACOASTAL CITY LA FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SATURDAY FOR COASTAL WATERS
FROM CAMERON LA TO HIGH ISLAND TX OUT 20 NM-WATERS FROM
CAMERON LA TO HIGH ISLAND TX FROM 20 TO 60 NM.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SATURDAY FOR COASTAL WATERS
FROM INTRACOASTAL CITY TO CAMERON LA OUT 20 NM-WATERS FROM
INTRACOASTAL CITY TO CAMERON LA FROM 20 TO 60 NM.
SMALL CRAFT EXERCISE CAUTION THROUGH SATURDAY AFTERNOON FOR
SABINE LAKE.
SMALL CRAFT EXERCISE CAUTION THROUGH SATURDAY AFTERNOON FOR
CALCASIEU LAKE.
SMALL CRAFT EXERCISE CAUTION FROM 3 PM CST THIS AFTERNOON
THROUGH SATURDAY AFTERNOON FOR VERMILION BAY.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
637 PM EST SAT DEC 7 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS DIGGING FROM NRN
CA INTO NEVADA. AT THE SFC...WRLY WINDS PREVAILED THROUGH THE UPPER
GREAT LAKES TO THE NORTH OF THE ARCTIC RIDGE BUILDING FROM THE NRN
PLAINS AND UPPER MS VALLEY TO THE SRN LAKES. VERY COLD AIR REMAINED
WITH MID AFTERNOON READINGS ONLY CLIMBING INTO THE 5F TO 15F RANGE
THROUGH MID AFTERNOON. VIS SATELLITE INDICATED BACKING WINDS OVER
WRN LAKE SUPERIOR WITH THE LES BANDS BECOMING ALIGNED FROM SW-NE.
TONIGHT...EXPECT LES BANDS INTO THE KEWEENAW TO LIFT SLOWLY
NORTHWARD THIS EVENING. EVEN THOUGH THE HIGHER RES MODELS INDICATED
PERSISTENT LOW LEVEL CONV AND LES FROM AT LEAST CMX
NORTHWARD...CONFIDENCE IS LOWER GIVEN THE SATELLITE TRENDS. SO...THE
ONGOING HEADLINES WERE RETAINED FOR NOW BUT MAY NEED TO BE LIFTED
EARLIER THAN PREVIOUSLY FCST. IF A DOMINANT BAND CAN REDEVELOP AND
BRUSH THE WRN SHORE OF THE KEWEENAW...ADDITIONAL SNOWFALL AMOUNTS OF
3 TO 6 INCHES MAY BE POSSIBLE.
WITH A PERIOD OF FAVORABLE RADIATIONAL COOLING UNTIL LATE TONIGHT...
EXPECT MIN TEMPS NEAR LOWER END OF GUIDANCE WITH LOW TO MID TEENS
BELOW ZERO ACROSS MUCH OF THE WRN INTERIOR RANGING TO AROUND ZERO
OVER THE INTERIOR EAST. WINDS INTO THE 5 T0 10 MPH RANGE TIL LATE
TONIGHT CAUSED WIND CHILL READINGS TO DIP TO NEAR 25 BELOW...SO THE
WIND CHILL ADVISORY WAS RETAINED. THE POTENTIAL FOR INCREASING HIGH
CLOUDS LATE TONIGHT COULD CAUSE TEMPS TO LEVEL OFF A BIT OR RISE
SLIGHTLY TOWARD 12Z SUN.
SUN...ANY REMAINING LES IS EXPECTED TO LIFT TO THE NORTH OF KEWEENAW
AS WINDS BACK IN THE DEVELOPING WAA PATTERN. A BROAD AREA OF
280K-290K ISENTROPIC LIFT WILL BRING LIGHT SNOW FROM MN/WI INTO
UPPER MI DURING THE AFTERNOON. ALTHOUGH...THE VERY DRY LOW LEVELS IN
THE ARCTIC AIRMASS MAY DELAY THE ONSET OF THE PCPN...EXPECT AT LEAST
SOME LIGHT SNOW OVER THE SOUTH IN THE AFTERNOON THAT WILL SPREAD
THROUGH THE REST OF THE CWA BY MID TO LATE AFTERNOON. ACCUMULATIONS
BY 00Z/09 WILL BE RELATIVELY LIGHT...AROUND A HALF INCH OR
LESS...MAINLY OVER THE SOUTH.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013
DEEP TROUGHING ORIENTED FROM EASTERN CANADA ACROSS THE GREAT LAKES
AND WEST TO THE SOUTHWEST CONUS IS REINFORCED THROUGHOUT THE UPCOMING
WEEK. COLD AIRMASS MAY FINALLY MAY START TO RELAX BY NEXT WEEKEND AS
FLOW ALOFT BECOMES MORE ZONAL. FLOW PATTERN THIS WEEK REMAINS ACTIVE
ACROSS THE UPPER LAKES. A COUPLE OF SYSTEMS WILL CROSS THE AREA WITH
WIDESPREAD SYSTEM SNOWS. MOST SIGNIFICANT OF THESE WILL OCCUR SUNDAY
NIGHT AS SHORTWAVE/PV ANAMOLY CROSSING NEVADA/UTAH THIS AFTN/EVENING
HEADS OUT INTO CNTRL PLAINS SUNDAY AFTN THEN LIFTS ACROSS UPPER
GREAT LAKES SUNDAY NIGHT. SLIGHT WARM AIR ADVECTION...RELATIVE
TERM IN THIS AIRMASS...OCCURS OVER SOUTH CENTRAL AND EASTERN CWA
SUNDAY EVENING WITH PVA/DEEP LAYER FORCING THROUGH REST OF NIGHT.
CROSS-SECTIONS INDICATE VERY SHALLOW FGEN FORCING BLO H9...MAINLY
SOUTH AND EAST. MINIMAL SLANTWISE INSTABILITY/NEGATIVE EPV TO RESULT
IN HEAVIER BANDED SNOW THOUGH. ENHANCEMENT TO SYSTEM SNOW MAY OCCUR
NEAR BAY OF GREEN BAY AND LK MICHIGAN WITH ESE/E WINDS IN LOW-LEVELS
WITH TEMPS AT INVERSION TOP OF H85 AROUND -10C /LK MICHIGAN WATER
TEMPS ARE AROUND +5C/. TRICK IS HOW LONG FAVORABLE WIND DIRECTION
PERSISTS AND WHETHER THERE IS TOO MUCH SHEAR IN LAKE CONVECTIVE
LAYER TO OFFSET THIS. EXPECT GENERAL 2-4" OF SYNOPTIC SNOW WITH
MIXING RATIOS 1-2G/KG AND WITH 0.15-0.20 AVERAGED MODEL QPF USING
SLR/S 17-19:1. BASED ON SOUNDINGS...HIGHER SLR/S SEEMED TOUGHER TO
ACHIEVE AS BULK OF LIFT WILL BE OCCURRING AT TEMPS LESS THAN -20C.
SLR/S WILL PROBABLY BE EVEN LOWER HEADING FARTHER NORTH INTO UPR
MICHIGAN...SO SNOW AMOUNTS OF AN INCH MAYBE TWO ARE EXPECTED CLOSER
TO LK SUPERIOR SHORE. ISSUED WINTER WEATHER ADVY FOR THE SYSTEM
SNOW. BASED ON SREF PLUMES AND FCST POPS...VALID TIME OF ADVY FAR
SCNTRL WILL START LATE SUNDAY AFTN AND GO THROUGH DAYBREAK ON
MONDAY. ADVY FOR ZONES TO THE EAST WILL START AND END A FEW HOURS
LATER.
LOW PRESSURE SYSTEM LIFTS TO NORTHEAST OF LK SUPERIOR BY 18Z ON
MONDAY AND THIS WILL USHER IN ANOTHER RETURN TO THE COLD AND WINDY
WEATHER THAT OCCURRED LATE THIS LAST WEEK INTO TODAY. AND YES...LAKE
EFFECT SNOWS...HEAVY AT TIMES...WILL RAMP UP AGAIN IN THE AREAS
FAVORED BY WNW-W FLOW. SO...ONCE AGAIN...KEWEEENAW PENINSULA WILL BE
IN LINE FOR HEAVY LK EFFECT SNOWS. SOUNDINGS IN WAKE OF THE LOW
PRESSURE INDICATE MOIST/UNSTABLE PROFILE TO H7 WITH SHARP CONVERGENCE
DEVELOPING ACROSS KEWEENAW BY MID MORNING MONDAY AND CONTINUING
THROUGH AT LEAST LATE EVENING ON MONDAY NIGHT. SIMILAR TO
THURSDAY...IF WESTERLY FLOW CAN PERSIST IN ONE AREA...LEADING TO
STRONG CONVERGENCE...FOOT PLUS AMOUNTS WILL BE POSSIBLE ACROSS CNTRL
HOUGHTON COUNTY... AFFECTING PAINESDALE...ATLANTIC MINE...HOUGHTON
AND HANCOCK AND POSSIBLY AS FAR NORTH AS CALUMET AND MOHAWK. LAKE
EFFECT HEADLINES ARE RUNNING THEIR COURSE CURRENTLY...SO DID NOT
WANT TO PUT UP ANOTHER LK EFFECT SNOW WATCH AT THIS TIME. WILL LET
MID SHIFT ASSESS THIS POTENTIAL. MAIN ISSUE AWAY FM THE INCREASING
LK EFFECT BY MONDAY AFTN WILL BE ANOTHER BLAST OF COLD TEMPS AND
LOWERING WIND CHILL READINGS.
DOES APPEAR THAT AS STRONGER SHORTWAVE/PRETTY DECENT AREA OF H7-H5
Q-VECTOR CONVERGENCE ARRIVES LATER MONDAY NIGHT...BLYR WINDS BACK SW
ENOUGH TO DISRUPT HEAVIER SNOW ON THE KEWEENAW. THIS MAY PROVIDE A
GOOD BREAK POINT FOR WHATEVER HEADLINE IS ISSUED FOR MONDAY AND
MONDAY EVENING...THOUGH THERE IS A CHANCE THE HEAVIER SNOW BANDS
WILL JUST MAKE INTO KEWEENAW COUNTY BEFORE STALLING OUT. TOUGH TO
SAY AT THIS POINT. SOUNDINGS ELSEHWERE INDICATE ENOUGH MOISTENING
AND LIFT TO INCREASE POPS FOR THE SYSTEM...ESPECIALLY NORTH HALF.
SNOW AMOUNTS FM THE SYSTEM WILL BE ON THE LGT SIDE...LESS THAN AN
INCH MAINLY. OTHER IMPACT FM THE SHORTWAVE WILL BE FOR TEMPS TO TRY
TO RISE SOME LATER MONDAY NIGHT AS THE WINDS INCREASE. THIS MAKES
FOR TRICKY WIND CHILL FORECAST. CURRENT FCST FOR WINDS AND TEMPS
DOES SUGGEST THAT WESTERN HALF OF CWA MAY SEE WIND CHILL CRITERIA
BE MET AT TIMES ON MONDAY NIGHT INTO TUESDAY MORNING. LAST IMPACT
FROM THE SYSTEM WILL BE TO PUSH STRONGER SFC TROUGH SOUTH ACROSS LK
SUPERIOR RESULTING IN MORE OF A NW WIND IN BLYR FOR TUESDAY/TUESDAY
NIGHT. USED LK EFFECT CLIMATOLOGY POPS TO BRING HIGHER POPS TO AREAS
FAVORED BY WNW FLOW SUCH AS ONTONAGON COUTNY AND ALSO IN THE EASTERN
CWA...MAINLY EAST OF MUNISING AND TO THE NORTH OF NEWBERRY.
IN WAKE OF THE TROUGH PASSAGE...COLDEST AIR OF WEEK POURS ACROSS
WITH H85 TEMPS DOWN TO AROUND -25C TUESDAY NIGHT INTO WEDNESDAY.
MAY HAVE MORE WIND CHILL ISSUES TUESDAY NIGHT INTO WEDNESDAY AS
INLAND TEMPS FALL BLO ZERO AND WINDS STAY UP BEHIND THE TROUGH.
COLDEST DAY OF THE WEEK FOR WEDNESDAY WITH MAX TEMPS OVER INLAND
WEST POSSIBLY STAYING AT OR BLO ZERO THE ENTIRE DAY. COLDEST NIGHT
OF THE WEEK LIKELY ON WEDNESDAY NIGHT. AS WINDS GO CALM MAY SEE MINS
LESS THAN 20 BLO ZERO.
SLIGHT WARMING TREND FOR LATE THIS WEEK...BUT STILL QUITE A BIT BLO
NORMAL FOR DAYTIME HIGHS. WEST/SOUTHWEST FLOW LK EFFECT STAYS IN
PLACE ON KEWEENAW THURSDAY BUT THEN SHOULD REORIENT TO MORE NNW-N
FLOW AREAS ON FRIDAY AS ANOTHER SFC TROUGH SWINGS ACROSS. MAY SEE
SOME SYSTEM SNOW THURSDAY NIGHT INTO FRIDAY AHEAD OF THAT TROUGH BUT
THERE ARE SOME TIMING ISSUES THERE STILL...SO WILL JUST HAVE LOW
CHANCE POPS FOR NOW. DID BUMP UP THE CONSENSUS POPS FOR THE LK
EFFECT AREAS.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SUNDAY EVENING)
ISSUED AT 637 PM EST SAT DEC 7 2013
WITH A DRY ARCTIC AIR MASS OVER THE AREA...AN OFFSHORE WIND
DIRECTION AT KIWD/KSAW WILL RESULT IN VFR CONDITIONS THRU SUN
MORNING. AT KCMX...LAKE EFFECT SNOW WILL CONTINUE THROUGH EARLY SUN
MORNING AS WINDS WILL CONTINUE TO HAVE ENOUGH OF AN ONSHORE
COMPONENT. WITH HEAVIER SNOW BANDS LIKELY REMAINING N OF KCMX...
EXPECT CONDITIONS TO VARY GENERALLY BTWN IFR AND MVFR THRU THE
NIGHT. WITH LOSS OF ONSHORE WIND COMPONENT SUN MORNING AS WINDS
BACK...CONDITIONS WILL IMPROVE TO VFR. IN THE AFTN...NEXT
DISTURBANCE WILL APPROACH FROM THE SW. EXPECT -SN AND MVFR
CONDITIONS TO SPREAD NE TO ALL TERMINALS DURING THE AFTN...BEGINNING
FIRST AT KIWD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST SAT DEC 7 2013
EXPECT BRIEF BREAK IN STRONGER WINDS OVER LK SUPERIOR LATER THIS
EVENING THROUGH SUNDAY AS PRESSURE GRADIENT WEAKENS. A LOW PRESSURE
SYSTEM MOVING ACROSS THE AREA ON SUNDAY NIGHT...BUT WINDS WILL REMAIN
LESS THAN 25 KTS. AS THE LOW MOVES OUT OF THE AREA ON MONDAY...EXPECT
THE GRADIENT TO TIGHTEN AND WEST GALES TO DEVELOP THROUGH MONDAY
NIGHT. ANOTHER LOW PRESSURE SYSTEM WILL PASS THROUGH THE UPPER GREAT
LAKES TUESDAY INTO WEDNESDAY...POSSIBLY LEADING TO MORE GALES FROM
THE WEST TO NORTHWEST TUESDAY AFTERNOON THROUGH WEDNESDAY EVENING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 AM EST SUNDAY FOR MIZ003.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ SUNDAY TO 7 AM
EST /6 AM CST/ MONDAY FOR MIZ012-013.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST SUNDAY FOR MIZ001.
WIND CHILL ADVISORY UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR MIZ002-
004-009>011-084.
WINTER WEATHER ADVISORY FROM 7 PM SUNDAY TO 9 AM EST MONDAY FOR
MIZ007-014-085.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ264>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ THIS
EVENING FOR LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
239 PM EST FRI DEC 6 2013
LATEST UPDATE...
SYNOPSIS/HYDRO/MARINE
.SYNOPSIS...
ISSUED AT 238 PM EST FRI DEC 6 2013
THE COLDEST EARLY DECEMBER TEMPERATURES SINCE 2005 ARE EXPECTED.
SNOW SHOWERS WILL PREVAIL WITH 1 TO 2 INCHES OF ACCUMULATION NEAR
AND WEST OF US-131 THROUGH SATURDAY EVENING. FROM SUNDAY NIGHT
INTO MONDAY EXPECT A GENERAL SNOWFALL OF 1 TO 3 INCHES. LAKE
EFFECT SNOW SHOWERS ARE EXPECTED MIDDAY MONDAY THROUGH THURSDAY
WITH SIGNIFICANT ACCUMULATIONS POSSIBLE WEST OF US-131.
&&
.UPDATE...
ISSUED AT 1128 AM EST FRI DEC 6 2013
I UPDATED THE FORECAST TO SHOW HIGHER PROBABILITIES OF LIGHT SNOW
SHOWERS WEST OF US-131 BASED ON RADAR RETURNS...SURFACE OBS (BIV
1 1/2-4SM -SN/ MKG 2-4SM -SN)...LAKE ENHANCED IR IMAGE LOOPS AND
USING THE OMEGA AND RH FROM THE LATEST RAP MODEL IN THE 0-2KM
LAYER. THE LATEST RAP MODEL SUGGESTS THE AREA OF BEST LIFT WILL
SHIFT SOUTH THIS AFTERNOON FROM WHITEHALL TO SOUTH HAVEN NOW... TO
HOLLAND TO BENTON HARBOR BY MID AFTERNOON. INLAND EXPECT JUST
FLURRIES (I PUT FLURRIES IN THE GRIDS TOO). AS ALWAYS IN THESE
SITUATIONS EVEN THE HIGH RES MODELS ARE HAVING A PROBLEM
FORECASTING THIS TYPE OF SNOW SHOWER ACTIVITY.
I STILL EXPECT THE BETTER ACCUMULATIONS TONIGHT INTO SATURDAY SO I
UPDATED THOSE GRIDS TO SHOW HIGHER PROBABILITIES. STILL
ACCUMULATIONS SHOULD BE LESS THAN 2 INCHES IN MOST PLACES.
ELSEWHERE AND OTHERWISE THE FORECAST IS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 332 AM EST FRI DEC 6 2013
THE MAIN FOCUS OF THE SHORT TERM PORTION OF THE FCST REMAINS LAKE
EFFECT TRENDS THROUGH THE PERIOD WITH COLD AIR EXPECTED TO REMAIN IN
PLACE. NO REAL CHANGES HAVE BEEN MADE WITH THE FCST AS MODELS ARE
SHOWING GOOD RUN TO RUN CONSISTENCY.
LAKE EFFECT HAS BEEN SLOW TO GET STARTED WITH THIS COLD AIR
MASS...AND THAT CONTINUES TO BE THE CASE THIS MORNING. SOME FLURRIES
ARE BEING REPORTED AT KCAD JUST NORTH OF THE CWFA...BUT NOTHING IN
THE CWFA AS OF 08Z THIS MORNING. THE LACK OF MOISTURE DEPTH AND LACK
OF LOW LEVEL CONVERGENCE UNDER FAIRLY ROBUST SUBSIDENCE WITH THE
ENTRANCE REGION OF THE STRONG UPPER JET IS OVERCOMING THE HEALTHY
OVER LAKE INSTABILITY.
WE DO EXPECT TO SEE A FEW SNOW SHOWERS DEVELOP TODAY. ONGOING CAA
WILL HELP A BIT TO LOWER THE DGZ INTO THE LIMITED MOISTURE LAYER A
BIT BETTER. THE AFOREMENTIONED LIMITING FACTORS WILL KEEP ANY SNOW
SHOWERS UNDER CONTROL TODAY. THE ONGOING CAA WILL LIMIT THE AMOUNT
OF WARMING FOR TEMPS TODAY. HIGHS SHOULD NOT CLIMB ABOVE THE UPPER
20S AFTER WE LOSE A FEW DEGREES THIS MORNING.
WE CONTINUE TO ANTICIPATE AN UPTICK IN LAKE EFFECT SNOW SHOWER
ACTIVITY FOR TONIGHT AND EARLY SAT MORNING. THIS UPTICK IS EXPECTED
TO BE THE RESULT OF A SHORT WAVE/PV ANOMALY CURRENTLY OVER NM THIS
MORNING LIFTING TO THE NE OVER THE AREA TONIGHT. INVERSION HEIGHTS
WILL BUMP UP TO AROUND 5K FEET OR SO. AT THE SAME TIME...A BIT OF
MID LEVEL MOISTURE WILL TRY TO HELP SNOW SHOWER GENERATION WITH A
SEEDER FEEDER TYPE OF SCENARIO. THERE WILL BE ABOUT 4-6K FT OF DRY
AIR IN BETWEEN THE LAYERS...SO IT IS NOT A GUARANTEE THIS WILL
ABSOLUTELY HELP. THE DGZ WILL BE SATURATED QUITE A BIT WHICH WILL
HELP FOR THE SNOW CAUSE. WNW FLOW FAVORED AREAS WILL SEE THE BEST
CHC OF SNOW SHOWERS AND SOME ACCUMULATIONS. LOW LEVEL CONVERGENCE IS
STILL LACKING...SO WE DO NOT EXPECT SNOW AMOUNTS TO GET OUT OF HAND.
WE WILL SEE THE LAKE EFFECT SNOW SHOWERS THEN GRADUALLY DIMINISH IN
COVERAGE AND INTENSITY DURING THE DAY ON SAT. THE NM SHORT WAVE WILL
EXIT THE AREA AND SUBSIDENCE WILL TAKE CONTROL ONCE AGAIN. INVERSION
HEIGHTS ARE EXPECTED TO LOWER TO AROUND 3K FEET...BEFORE LOW LEVEL
MOISTURE IS EXPECTED TO DISSIPATE WITH A STRONG ARCTIC SFC RIDGE
MOVING DIRECTLY OVERHEAD. THIS WILL ALLOW FOR A COLD SAT NIGHT WITH
SOME CLEARING LIKELY.
THE CLEARING AND BREAK IN THE SNOW SHOWERS WILL BE SHORT LIVED. WE
WILL SEE ADDITIONAL SHORT WAVE ENERGY EJECT OUT FROM THE WRN U.S.
TROUGH AND APPROACH THE AREA SUN AFTERNOON. SOME MOISTURE FROM THE
STRONG STORM SYSTEM EXPECTED ACROSS THE SE STATES WILL WRAP INTO
THIS WAVE AS IT IS PASSING ACROSS THE STATE. THE MOISTURE IS NOT
THAT RICH AS THE BEST MOISTURE WILL REMAIN WELL SE OF THE AREA WITH
THE MAIN BAROCLINIC/FRONTAL ZONE ACROSS THE SE PORTION OF THE
COUNTRY. FORCING IS LIMITED TOO THIS FAR NORTH WITH THE MAIN
ISENTROPIC ASCENT REMAINING WELL SOUTH AND EAST. THIS LOOKS LIKE A
LIGHT SNOW EVENT WHERE MOST OF THE AREA WILL SEE AN INCH OR TWO OF
SNOW ACCUMULATION.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 AM EST FRI DEC 6 2013
THE SYNOPTIC SYSTEM FOR SUNDAY NIGHT CONTINUES TO LOOK LESS
IMPRESSIVE WITH EACH MODEL RUN. WEAK/BAGGY SFC LOW PRESSURE PATTERN
PASSES ACROSS LOWER MI WITH ONLY AROUND ONE TENTH OF AN INCH OF QPF.
NO DECENT/AMPLIFIED SHORTWAVE IS PRESENT ALOFT...AND INSTEAD IT IS
JUST A SHEARED OUT/ELONGATED VORTICITY PATTERN.
THERE IS ALSO THE ISSUE OF A POTENTIAL MID LEVEL DRY SLOT SWEEPING
IN WHICH COULD LEAD TO MORE OF A LIGHT FREEZING RAIN/DRIZZLE THREAT
SUNDAY NIGHT RATHER THAN LIGHT SNOW. WILL KEEP LIKELY POPS FOR LIGHT
SNOW OVER THE ENTIRE AREA FOR NOW BUT IF THE TRENDS CONTINUE THEN
THE FREEZING PRECIP THREAT MAY NEED TO BE ADDED IN LATER FORECASTS.
COLD ADVECTION FOLLOWS ON MONDAY BEHIND THE WEAK EXITING SYSTEM BUT
THE REALLY COLD ARCTIC AIR DOES NOT ARRIVE UNTIL TUESDAY OR TUESDAY
NIGHT. IT IS THE CLIPPER SYSTEM TRACKING ACROSS LAKE SUPERIOR WHICH
BRINGS IN THE COLD AIR AND PERHAPS A BETTER RISK OF SOME
ACCUMULATING LAKE EFFECT SNOW. EVEN THIS IS QUESTIONABLE HOWEVER
SINCE THE CORE OF THE UPPER JET DOES NOT DIP SOUTH OF THE STATE AND
MOISTURE IS RATHER SHALLOW/LIMITED.
THE LAKE EFFECT SNOW SHOWER THREAT IS EXPECTED TO DIMINISH THURSDAY
AS SURFACE RIDGING BUILDS IN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1233 PM EST FRI DEC 6 2013
A MIX OF VFR AND MVFR CEILINGS CAN BE EXPECTED OVER THE NEXT 24
HOURS. THE BULK OF THE MVFR WILL BE DOWN WIND FROM LAKE MICHIGAN...
WITH NW OR WNW FLOW. THE MVFR CONDITIONS SHOULD BE MOST PERSISTENT
AT AZO...WITH VFR AND OCCASIONAL MVFR EXPECTED FOR THE REMAINDER
OF THE TAF SITES.
THERE WILL ALSO BE LIGHT SNOW SHOWERS COMING OFF THE LAKE. MOST
VSBYS WILL BE REDUCED INTO THE MVFR RANGE...HOWEVER A FEW ISOLATED
SNOW SHOWERS MAY BRING VSBYS DOWN INTO THE IFR RANGE. ONCE
AGAIN...WITH THE NW FLOW...AZO SHOULD SEE MORE FREQUENT SNOW
SHOWERS THEN THE REST OF THE TAF SITES. THE HIGHEST IMPACT SNOW
SHOWERS SHOULD OCCUR FROM ROUGHLY 04Z TO 14Z SATURDAY WHEN THE
BEST LOW LEVEL MOISTURE IS REALIZED.
&&
.MARINE...
ISSUED AT 238 PM EST FRI DEC 6 2013
LITTLE REASON TO CHANGE OUR FORECAST OR HEADLINES AT THIS POINT.
NORTHWEST WINDS OF 15 TO 25 KNOTS WILL KEEP WAVES IN THE 4 TO 7
FOOT RANGE INTO SATURDAY BEFORE WINDS DIMINISH LATE IN THE DAY
ALLOWING WAVE HEIGHTS TO ALSO DIMINISH.
&&
.HYDROLOGY...
ISSUED AT 238 PM EST FRI DEC 6 2013
WE WILL CONTINUE TO MONITOR THE ICE JAM THREAT AS THE COLD WEATHER
PERSISTS. THE GENERAL SNOWFALL SUNDAY NIGHT INTO MONDAY MAY
FACILITATE ICE FORMATION ON AREA RIVERS.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...WDM
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...JK
HYDROLOGY...WDM
MARINE...WDM
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1233 PM EST FRI DEC 6 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 332 AM EST FRI DEC 6 2013
COLD AIR IS EXPECTED TO REMAIN IN PLACE THROUGH THE WEEKEND. THERE
WILL BE SOME LAKE EFFECT SNOW SHOWERS THROUGH SATURDAY. NO
SIGNIFICANT ACCUMULATIONS ARE EXPECTED. MOST OF THE AREA SHOULD SEE
LIGHT SNOW ACCUMULATIONS LATE SUNDAY THROUGH MONDAY AS A WAVE OF LOW
PRESSURE MOVES THROUGH THE AREA.
COLDER AIR WILL MOVE IN DURING THE EARLY PORTION OF NEXT WEEK.
CONDITIONS LOOK A BIT MORE FAVORABLE FOR LAKE EFFECT SNOW
ACCUMULATIONS NEXT WEEK...ESPECIALLY ACROSS THE WESTERN HALF OF THE
AREA.
&&
.UPDATE...
ISSUED AT 1128 AM EST FRI DEC 6 2013
I UPDATED THE FORECAST TO SHOW HIGHER PROBABILITIES OF LIGHT SNOW
SHOWERS WEST OF US-131 BASED ON RADAR RETURNS...SURFACE OBS (BIV
1 1/2-4SM -SN/ MKG 2-4SM -SN)...LAKE ENHANCED IR IMAGE LOOPS AND
USING THE OMEGA AND RH FROM THE LATEST RAP MODEL IN THE 0-2KM
LAYER. THE LATEST RAP MODEL SUGGESTS THE AREA OF BEST LIFT WILL
SHIFT SOUTH THIS AFTERNOON FROM WHITEHALL TO SOUTH HAVEN NOW... TO
HOLLAND TO BENTON HARBOR BY MID AFTERNOON. INLAND EXPECT JUST
FLURRIES (I PUT FLURRIES IN THE GRIDS TOO). AS ALWAYS IN THESE
SITUATIONS EVEN THE HIGH RES MODELS ARE HAVING A PROBLEM
FORECASTING THIS TYPE OF SNOW SHOWER ACTIVITY.
I STILL EXPECT THE BETTER ACCUMULATIONS TONIGHT INTO SATURDAY SO I
UPDATED THOSE GRIDS TO SHOW HIGHER PROBABILITIES. STILL
ACCUMULATIONS SHOULD BE LESS THAN 2 INCHES IN MOST PLACES.
ELSEWHERE AND OTHERWISE THE FORECAST IS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 332 AM EST FRI DEC 6 2013
THE MAIN FOCUS OF THE SHORT TERM PORTION OF THE FCST REMAINS LAKE
EFFECT TRENDS THROUGH THE PERIOD WITH COLD AIR EXPECTED TO REMAIN IN
PLACE. NO REAL CHANGES HAVE BEEN MADE WITH THE FCST AS MODELS ARE
SHOWING GOOD RUN TO RUN CONSISTENCY.
LAKE EFFECT HAS BEEN SLOW TO GET STARTED WITH THIS COLD AIR
MASS...AND THAT CONTINUES TO BE THE CASE THIS MORNING. SOME FLURRIES
ARE BEING REPORTED AT KCAD JUST NORTH OF THE CWFA...BUT NOTHING IN
THE CWFA AS OF 08Z THIS MORNING. THE LACK OF MOISTURE DEPTH AND LACK
OF LOW LEVEL CONVERGENCE UNDER FAIRLY ROBUST SUBSIDENCE WITH THE
ENTRANCE REGION OF THE STRONG UPPER JET IS OVERCOMING THE HEALTHY
OVER LAKE INSTABILITY.
WE DO EXPECT TO SEE A FEW SNOW SHOWERS DEVELOP TODAY. ONGOING CAA
WILL HELP A BIT TO LOWER THE DGZ INTO THE LIMITED MOISTURE LAYER A
BIT BETTER. THE AFOREMENTIONED LIMITING FACTORS WILL KEEP ANY SNOW
SHOWERS UNDER CONTROL TODAY. THE ONGOING CAA WILL LIMIT THE AMOUNT
OF WARMING FOR TEMPS TODAY. HIGHS SHOULD NOT CLIMB ABOVE THE UPPER
20S AFTER WE LOSE A FEW DEGREES THIS MORNING.
WE CONTINUE TO ANTICIPATE AN UPTICK IN LAKE EFFECT SNOW SHOWER
ACTIVITY FOR TONIGHT AND EARLY SAT MORNING. THIS UPTICK IS EXPECTED
TO BE THE RESULT OF A SHORT WAVE/PV ANOMALY CURRENTLY OVER NM THIS
MORNING LIFTING TO THE NE OVER THE AREA TONIGHT. INVERSION HEIGHTS
WILL BUMP UP TO AROUND 5K FEET OR SO. AT THE SAME TIME...A BIT OF
MID LEVEL MOISTURE WILL TRY TO HELP SNOW SHOWER GENERATION WITH A
SEEDER FEEDER TYPE OF SCENARIO. THERE WILL BE ABOUT 4-6K FT OF DRY
AIR IN BETWEEN THE LAYERS...SO IT IS NOT A GUARANTEE THIS WILL
ABSOLUTELY HELP. THE DGZ WILL BE SATURATED QUITE A BIT WHICH WILL
HELP FOR THE SNOW CAUSE. WNW FLOW FAVORED AREAS WILL SEE THE BEST
CHC OF SNOW SHOWERS AND SOME ACCUMULATIONS. LOW LEVEL CONVERGENCE IS
STILL LACKING...SO WE DO NOT EXPECT SNOW AMOUNTS TO GET OUT OF HAND.
WE WILL SEE THE LAKE EFFECT SNOW SHOWERS THEN GRADUALLY DIMINISH IN
COVERAGE AND INTENSITY DURING THE DAY ON SAT. THE NM SHORT WAVE WILL
EXIT THE AREA AND SUBSIDENCE WILL TAKE CONTROL ONCE AGAIN. INVERSION
HEIGHTS ARE EXPECTED TO LOWER TO AROUND 3K FEET...BEFORE LOW LEVEL
MOISTURE IS EXPECTED TO DISSIPATE WITH A STRONG ARCTIC SFC RIDGE
MOVING DIRECTLY OVERHEAD. THIS WILL ALLOW FOR A COLD SAT NIGHT WITH
SOME CLEARING LIKELY.
THE CLEARING AND BREAK IN THE SNOW SHOWERS WILL BE SHORT LIVED. WE
WILL SEE ADDITIONAL SHORT WAVE ENERGY EJECT OUT FROM THE WRN U.S.
TROUGH AND APPROACH THE AREA SUN AFTERNOON. SOME MOISTURE FROM THE
STRONG STORM SYSTEM EXPECTED ACROSS THE SE STATES WILL WRAP INTO
THIS WAVE AS IT IS PASSING ACROSS THE STATE. THE MOISTURE IS NOT
THAT RICH AS THE BEST MOISTURE WILL REMAIN WELL SE OF THE AREA WITH
THE MAIN BAROCLINIC/FRONTAL ZONE ACROSS THE SE PORTION OF THE
COUNTRY. FORCING IS LIMITED TOO THIS FAR NORTH WITH THE MAIN
ISENTROPIC ASCENT REMAINING WELL SOUTH AND EAST. THIS LOOKS LIKE A
LIGHT SNOW EVENT WHERE MOST OF THE AREA WILL SEE AN INCH OR TWO OF
SNOW ACCUMULATION.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 AM EST FRI DEC 6 2013
THE SYNOPTIC SYSTEM FOR SUNDAY NIGHT CONTINUES TO LOOK LESS
IMPRESSIVE WITH EACH MODEL RUN. WEAK/BAGGY SFC LOW PRESSURE PATTERN
PASSES ACROSS LOWER MI WITH ONLY AROUND ONE TENTH OF AN INCH OF QPF.
NO DECENT/AMPLIFIED SHORTWAVE IS PRESENT ALOFT...AND INSTEAD IT IS
JUST A SHEARED OUT/ELONGATED VORTICITY PATTERN.
THERE IS ALSO THE ISSUE OF A POTENTIAL MID LEVEL DRY SLOT SWEEPING
IN WHICH COULD LEAD TO MORE OF A LIGHT FREEZING RAIN/DRIZZLE THREAT
SUNDAY NIGHT RATHER THAN LIGHT SNOW. WILL KEEP LIKELY POPS FOR LIGHT
SNOW OVER THE ENTIRE AREA FOR NOW BUT IF THE TRENDS CONTINUE THEN
THE FREEZING PRECIP THREAT MAY NEED TO BE ADDED IN LATER FORECASTS.
COLD ADVECTION FOLLOWS ON MONDAY BEHIND THE WEAK EXITING SYSTEM BUT
THE REALLY COLD ARCTIC AIR DOES NOT ARRIVE UNTIL TUESDAY OR TUESDAY
NIGHT. IT IS THE CLIPPER SYSTEM TRACKING ACROSS LAKE SUPERIOR WHICH
BRINGS IN THE COLD AIR AND PERHAPS A BETTER RISK OF SOME
ACCUMULATING LAKE EFFECT SNOW. EVEN THIS IS QUESTIONABLE HOWEVER
SINCE THE CORE OF THE UPPER JET DOES NOT DIP SOUTH OF THE STATE AND
MOISTURE IS RATHER SHALLOW/LIMITED.
THE LAKE EFFECT SNOW SHOWER THREAT IS EXPECTED TO DIMINISH THURSDAY
AS SURFACE RIDGING BUILDS IN.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1233 PM EST FRI DEC 6 2013
A MIX OF VFR AND MVFR CEILINGS CAN BE EXPECTED OVER THE NEXT 24
HOURS. THE BULK OF THE MVFR WILL BE DOWN WIND FROM LAKE MICHIGAN...
WITH NW OR WNW FLOW. THE MVFR CONDITIONS SHOULD BE MOST PERSISTENT
AT AZO...WITH VFR AND OCCASIONAL MVFR EXPECTED FOR THE REMAINDER
OF THE TAF SITES.
THERE WILL ALSO BE LIGHT SNOW SHOWERS COMING OFF THE LAKE. MOST
VSBYS WILL BE REDUCED INTO THE MVFR RANGE...HOWEVER A FEW ISOLATED
SNOW SHOWERS MAY BRING VSBYS DOWN INTO THE IFR RANGE. ONCE
AGAIN...WITH THE NW FLOW...AZO SHOULD SEE MORE FREQUENT SNOW
SHOWERS THEN THE REST OF THE TAF SITES. THE HIGHEST IMPACT SNOW
SHOWERS SHOULD OCCUR FROM ROUGHLY 04Z TO 14Z SATURDAY WHEN THE
BEST LOW LEVEL MOISTURE IS REALIZED.
&&
.MARINE...
ISSUED AT 332 AM EST FRI DEC 6 2013
WE ARE EXTENDING THE SMALL CRAFT ADVISORY FOR THE ENTIRE NEARSHORE
THROUGH 06Z SUN WITH THIS FCST PACKAGE. WINDS WILL COME DOWN TO
AROUND 15 TO 20 KNOTS TODAY AND REMAIN THERE THROUGH SAT. THE
ONSHORE FLOW AND UNSTABLE CONDITIONS WITH THE COLD AIR COMING IN
OVER THE LAKE WILL KEEP WAVES ABOVE 4 FEET THROUGH SAT. THERE SHOULD
BE A BREAK SAT NIGHT AND EARLY SUN.
&&
.HYDROLOGY...
ISSUED AT 332 AM EST FRI DEC 6 2013
THE ONLY CONCERN WITH HYDROLOGY REMAINS THE THREAT FOR ICE
DEVELOPMENT OVER THE NEXT WEEK. ARCTIC COLD AIR EXPECTED OVER THE
AREA THROUGH MOST OF THE NEXT WEEK WILL HELP ICE DEVELOPMENT. AS THE
ICE DEVELOPS...WE WILL BE MONITORING THE POTENTIAL FOR ICE JAMS TO
FORM.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...JK
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1156 AM EST FRI DEC 6 2013
.AVIATION...
//DISCUSSION...
AN MVFR STRATUS DECK HAS BEEN ON THE DOORSTEP OF MBS FOR THE LAST
HOUR. THE COMBINATION OF THE LOW LEVEL MOISTURE FLUX OFF LAKE
MICHIGAN AND THE DEPTH OF THE LOW LEVEL INVERSION SHOULD SUSTAIN
SOME DEGREE OF LOW CLOUDS INTO AT LEAST MBS THIS AFTERNOON AND
EVENING. THE MAIN LIMITING FACTOR WILL BE THE VERY DRY ARCTIC AIR
NOW ENVELOPING THE REGION. THE INCREASING RESPONSE NOTED OFF LAKE
MICHIGAN MAY ALLOW SOME OF THE STRATO CU TO PERIODICALLY ADVANCE
ACROSS FNT AND PTK THIS EVENING.
FOR DTW...THERE IS GROWING CONFIDENCE THAT POOR MOISTURE QUALITY
WILL KEEP ANY LIGHT SNOW/FLURRIES WELL SOUTH OF METRO THIS EVENING.
ALTHOUGH STRATO CU FROM THE WEST SIDE OF THE STATE WILL ATTEMPT TO
PUSH TOWARD THE EAST...THE DEGREE OF LOW LEVEL DRY AIR AND SLIGHT
DOWNSLOPE COMPONENT INTO METRO UNDER A WNW FLOW SUPPORTS NOTHING
MORE THAN SCT MVFR CLOUD BASES THIS EVENING.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE ON CEILINGS BELOW 5000 FT THIS EVENING AND
OVERNIGHT.
&&
.PREV DISCUSSION...ISSUED 1008 AM EST FRI DEC 6 2013
UPDATE...
THE THICK CANOPY OF MID/HIGH CLOUDS AND WEAK LOW LEVEL COLD AIR
ADVECTION THROUGH THE AFTERNOON WILL INHIBIT MUCH IF ANY DIURNAL
RESPONSE. THIS WILL SUPPORT A MINOR DOWNWARD ADJUSTMENT TO TEMPS
THIS AFTERNOON. THE DEPTH OF THE COLD AIR HAS BEEN INCREASING OVER
THE WESTERN GREAT LAKES WHICH IS LEADING TO A BETTER RESPONSE OFF
LAKE MI. THE 12Z DTX SOUNDING SHOWED A DEEP INVERSION BASED NEAR
920MB. THIS SHOULD ALLOW A GOOD DUCT FOR THE WESTWARD EXPANSION OF
LAKE STRATO CU. RAP SOUNDINGS ON BUFKIT SUGGEST SUPERSATURATION
WITH RESPECT TO ICE NEAR THE INVERSION LEVEL. SO IT SHOULD NOT BE
DIFFICULT TO GENERATE SOME FLURRIES FROM THESE LOWER BASED CLOUDS.
THIS WILL BE MORE PROBABLE ACROSS THE SAGINAW VALLEY AND THUMB
GIVEN THE WESTERLY FLOW. FARTHER SOUTH...THE LOW LEVEL FLOW
BECOMES HIGHLY DIVERGENT WHICH MAY KEEP THE LOW CLOUDS CONFINED TO
WRN LOWER MI THROUGH THE AFTERNOON.
PREV DISCUSSION...ISSUED 356 AM EST FRI DEC 6 2013
SHORT TERM...TODAY AND TONIGHT
THE WEATHER FOR SOUTHEASTERN MICHIGAN WILL BE INFLUENCED BY A
BAROCLINIC ZONE THAT IS IN PLACE FROM THE EASTERN GREAT LAKES
THROUGH MUCH OF THE OHIO RIVER VALLEY. THE FRONTAL BOUNDARY WILL
BECOME QUASI-STATIONARY TODAY AS THE VERY STRONG...POLAR JET AXIS
OVERHEAD BECOMES FAIRLY STATIC. CHARACTERISTICS OF THE FRONT OFFERED
BY CROSS SECTIONS ARE: 1. GRADUALLY SLOPED 2. A DOUBLE GRADIENT
STRUCTURE AT ROUGHLY 750 MB AND 550 MB.
A WAVE IS EXPECTED TO RIPPLE ALONG THE BAROCLINIC ZONE LATE THIS
AFTERNOON AS A LOWER TROPOSPHERIC REFLECTION OF RIGHT ENTRANCE
REGION DYNAMICS. OVERALL PRECIPITATION CHANCES WILL BE NEAR ZERO FOR
MUCH OF THE CWA WITH CHANCES VERY LOW ACROSS MONROE COUNTY. THE
REASON IS ANALYSES OF LOW TO MID TROPOSPHERIC -DIV AND DEFORMATION
ADVERTISE VERY LITTLE FORCING. IN ADDITION...CROSS SECTIONS SUPPORT
SUBSIDENCE THIS AFTERNOON BETWEEN THE 750 MB AND 550 MB GRADIENTS
ALONG WITH RELATIVELY HIGH STATIC STABILITY THROUGH A GOOD CHUNK OF
THE COLUMN. A DRY LAYER BELOW THE 750MB GRADIENT WILL PROVIDE AN
EVAPORATION BUFFER. IN THE SPIRIT OF CONTINUITY...CONTINUED TO
INCLUDE A LOW CHANCE POP OF LIGHT SNOW FOR MONROE COUNTY BETWEEN
21-02Z BUT ANY SNOWFALL...IF ANY...WILL BE NEGLIGIBLE. SOME FORCING
VERY HIGH IN COLUMN IS STILL EXPECTED TO OVERLAP SOUTHEASTERN
MICHIGAN WHICH SHOULD PROVIDE AN ABUNDANCE OF HIGH CLOUD FOR MUCH OF
THE DAYLIGHT HOURS.
SLUGGISH MOVEMENT OF THE FRONT TODAY WILL GIVE SOME POTENTIAL AT
AFTERNOON HIGHS DESPITE THE CLOUDS. FREEZING MARK SOUTH...TO MIDDLE
20S NORTH. WIND CHILLS WILL DROP INTO THE TEENS THIS MORNING...THEN
STRUGGLE TO CLIMB ABOVE 20 FOR THE AFTERNOON. SUBSIDENCE OCCURRING
BEHIND THE WAVE LATE TONIGHT ALONG WITH DRY AIR SHOULD ALLOW CLOUDS
TO SCATTER AN HOUR OR TWO BEFORE SUNRISE. TEMPERATURES WILL HAVE THE
POTENTIAL TO DROP...LOWS IN THE TEENS WIND CHILLS IN THE SINGLE
DIGITS FOR ALL OF SOUTHEASTERN MICHIGAN.
LONG TERM...SATURDAY THROUGH THURSDAY
HIGH AMPLITUDE MID LEVEL FLOW ANCHORED BY A SPRAWLING LONGWAVE
TROUGH WILL REMAIN THE CONTROLLING LARGE SCALE FEATURE WELL INTO
NEXT WEEK. THE WEEKEND BEGINS WITH SE MICHIGAN INITIALLY RESIDING
ALONG THE EASTERN EXTENSION OF THE MAIN HEIGHT FALL CENTER AND WELL
WITHIN THE COLD DOME PERPETUATED BY AN INBOUND 1040 MB ARCTIC HIGH.
AMBIENT AIRMASS WILL CARRY A DEEP DRY LAYER ABOVE 900 MB...WHILE A
CHECK OF UPSTREAM SOUNDINGS ACROSS LAKE MICHIGAN SHOW A PROFILE ALSO
LACKING IN MOISTURE DEPTH WITH SUPPRESSED INVERSION HEIGHTS. THIS
WOULD INDICATE THE OPPORTUNITY FOR A LAKE AND/OR DIURNALLY ENHANCED
STRATOCU FIELD WILL BE LIMITED. SOME LINGERING EARLY STRATUS MAY
EXIST...PARTICULARLY ACROSS THE NORTH WITH THE RESIDUAL MOISTURE
SOURCE FROM TODAY PERHAPS SLOWER TO MIX OUT. MAIN STORY WILL BE
TEMPERATURES...WITH EVEN A HIGH DEGREE OF INSOLATION STRUGGLING TO
MODERATE A THERMAL PROFILE CARRYING 925 MB TEMPERATURES IN THE -11
TO -12C RANGE. THIS WILL TRANSLATE INTO HIGHS OF LOWER TO MIDDLE
20S...OR A GOOD 15 DEGREE BELOW EARLY DECEMBER NORMS. THE EXISTING
SURFACE RIDGING AND DEEP DRY LAYER WILL PROMOTE A GOOD RADIATIONAL
COOLING RESPONSE SATURDAY NIGHT. A GRADUALLY INCREASING CIRRUS
SHIELD WILL BE THE ONE POSSIBLE DISRUPTION TO REALIZING THE FULL
POTENTIAL. OVERALL STILL LOOKING AT LOWS IN THE TEENS...A FEW
SINGLE DIGIT READINGS NOT OUT OF THE QUESTION IN THE COLDEST
LOCALES.
CONDITIONS INTO SUNDAY REMAIN DEFINED BY THE PRESENCE OF A COLD/DRY
ENVIRONMENT...LOW LEVEL FLOW FLIPPING TO EASTERLY WITH THE ARCTIC
HIGH SLOWLY EASING EASTWARD. HIGHS AGAIN IN THE 20S...EFFECTIVELY
CONTAINED BY A MORE CONCERTED INCREASE IN HIGH CLOUD. FOCUS INTO
SUNDAY EVENING/NIGHT THEN TURNS TO A WELL DEFINED PV ANOMALY WORKING
THROUGH THE TROUGH BASE. THIS WAVE WILL SHEAR INTO THE PREVAILING
SOUTHWESTERLIES ORIENTED FROM THE CENTRAL PLAINS INTO THE GREAT
LAKES THROUGH THE LATTER HALF OF THE WEEKEND. THIS PROCESS WILL
PROMPT TWO AREAS OF FOCUS...ONE WITHIN A WING OF EMERGING ISENTROPIC
ASCENT AND MOISTURE TRANSPORT ORIGINATING OUT OF THE WESTERN
GULF...AND A SECOND ACCOMPANYING THE PRIMARY REGION OF FORCED ASCENT
CONTAINED WITHIN THE MAIN HEIGHT FALL CENTER AND ALONG THE
DEVELOPING WEAK SURFACE WAVE AND FRONTAL CIRCULATION EJECTING OUT OF
THE PLAINS. THE OVERALL UPPER JET POSITIONING WOULD TEND TO DIRECT
THE BULK OF THE GULF ORIGINATING MOISTURE AND ATTENDANT WEAK ASCENT
TO OUR SOUTHEAST. IT REMAINS PLAUSIBLE FOR SOUTHERN SECTIONS OF
SOUTHEAST MICHIGAN TO RECEIVE A GLANCING SHOT ALONG THE WESTERN EDGE
SUNDAY EVENING. WEAK SURFACE WAVE THEN LIFTS THROUGH LOWER MICHIGAN
SUNDAY NIGHT...DISPLACED SOUTHEAST OF THE MAIN STRIPE OF DCVA AND
DEFORMATION FORCING SHIFTING FROM THE UPPER MS VALLEY INTO THE U.P.
THIS WILL LEAVE SE MICHIGAN UNDER A BROADER LOOKING PERIOD OF
FORCING...STILL SUFFICIENT TOWARD GENERATING A FEW HUNDREDTHS OF QPF
SUNDAY NIGHT. A SUB-FREEZING THERMAL PROFILE THROUGHOUT WILL
SUPPORT ALL SNOW...ALTHOUGH THE PROFILE WILL BE WARMING WITH
TIME...EFFECTIVELY REDUCING POTENTIAL SNOWFALL RATIOS.
A GENERAL EASTWARD MIGRATION OF THE MEAN LONGWAVE TROUGH WILL DIRECT
A SERIES SHORTWAVES OF SIBERIAN ORIGIN THROUGH THE GREAT LAKES
DURING THE EARLY AND MID WEEK PERIOD. THIS WILL RESULT IN AN
EXTENDED STRETCH OF WELL BELOW NORMAL TEMPERATURES AS ARCTIC AIR
TAKES FIRM RESIDENCE THROUGHOUT THE WEEK.
MARINE...
WESTERLY WINDS WILL DIMINISH SLIGHTLY TODAY AND TONIGHT AS THE
PRESSURE GRADIENT EASES BEHIND LOW PRESSURE LIFTING INTO QUEBEC.
THIS WILL RESULT IN A LOWER WAVE CONDITIONS THROUGH THIS TIME.
COLDER AIR MOVING ACROSS THE WATERS WILL MAINTAIN WIND SPEEDS IN
THE 15 TO 20 KNOT RANGE ACROSS NORTHERN PORTIONS OF LAKE HURON.
SLIGHT INCREASE IN WINDS EARLY SATURDAY WILL BRING GUSTS JUST SHY
OF GALES ACROSS NORTHERN LAKE HURON. STRONG HIGH PRESSURE WILL
THEN TAKE CONTROL SATURDAY NIGHT AND SUNDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...CB
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1128 AM EST FRI DEC 6 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 332 AM EST FRI DEC 6 2013
COLD AIR IS EXPECTED TO REMAIN IN PLACE THROUGH THE WEEKEND. THERE
WILL BE SOME LAKE EFFECT SNOW SHOWERS THROUGH SATURDAY. NO
SIGNIFICANT ACCUMULATIONS ARE EXPECTED. MOST OF THE AREA SHOULD SEE
LIGHT SNOW ACCUMULATIONS LATE SUNDAY THROUGH MONDAY AS A WAVE OF LOW
PRESSURE MOVES THROUGH THE AREA.
COLDER AIR WILL MOVE IN DURING THE EARLY PORTION OF NEXT WEEK.
CONDITIONS LOOK A BIT MORE FAVORABLE FOR LAKE EFFECT SNOW
ACCUMULATIONS NEXT WEEK...ESPECIALLY ACROSS THE WESTERN HALF OF THE
AREA.
&&
.UPDATE...
ISSUED AT 1128 AM EST FRI DEC 6 2013
I UPDATED THE FORECAST TO SHOW HIGHER PROBABILITIES OF LIGHT SNOW
SHOWERS WEST OF US-131 BASED ON RADAR RETURNS...SURFACE OBS (BIV
1 1/2-4SM -SN/ MKG 2-4SM -SN)...LAKE ENHANCED IR IMAGE LOOPS AND
USING THE OMEGA AND RH FROM THE LATEST RAP MODEL IN THE 0-2KM
LAYER. THE LATEST RAP MODEL SUGGESTS THE AREA OF BEST LIFT WILL
SHIFT SOUTH THIS AFTERNOON FROM WHITEHALL TO SOUTH HAVEN NOW... TO
HOLLAND TO BENTON HARBOR BY MID AFTERNOON. INLAND EXPECT JUST
FLURRIES (I PUT FLURRIES IN THE GRIDS TOO). AS ALWAYS IN THESE
SITUATIONS EVEN THE HIGH RES MODELS ARE HAVING A PROBLEM
FORECASTING THIS TYPE OF SNOW SHOWER ACTIVITY.
I STILL EXPECT THE BETTER ACCUMULATIONS TONIGHT INTO SATURDAY SO I
UPDATED THOSE GRIDS TO SHOW HIGHER PROBABILITIES. STILL
ACCUMULATIONS SHOULD BE LESS THAN 2 INCHES IN MOST PLACES.
ELSWHERE AND OTHERWISE THE FORECAST IS ON TRACK.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 332 AM EST FRI DEC 6 2013
THE MAIN FOCUS OF THE SHORT TERM PORTION OF THE FCST REMAINS LAKE
EFFECT TRENDS THROUGH THE PERIOD WITH COLD AIR EXPECTED TO REMAIN IN
PLACE. NO REAL CHANGES HAVE BEEN MADE WITH THE FCST AS MODELS ARE
SHOWING GOOD RUN TO RUN CONSISTENCY.
LAKE EFFECT HAS BEEN SLOW TO GET STARTED WITH THIS COLD AIR
MASS...AND THAT CONTINUES TO BE THE CASE THIS MORNING. SOME FLURRIES
ARE BEING REPORTED AT KCAD JUST NORTH OF THE CWFA...BUT NOTHING IN
THE CWFA AS OF 08Z THIS MORNING. THE LACK OF MOISTURE DEPTH AND LACK
OF LOW LEVEL CONVERGENCE UNDER FAIRLY ROBUST SUBSIDENCE WITH THE
ENTRANCE REGION OF THE STRONG UPPER JET IS OVERCOMING THE HEALTHY
OVER LAKE INSTABILITY.
WE DO EXPECT TO SEE A FEW SNOW SHOWERS DEVELOP TODAY. ONGOING CAA
WILL HELP A BIT TO LOWER THE DGZ INTO THE LIMITED MOISTURE LAYER A
BIT BETTER. THE AFOREMENTIONED LIMITING FACTORS WILL KEEP ANY SNOW
SHOWERS UNDER CONTROL TODAY. THE ONGOING CAA WILL LIMIT THE AMOUNT
OF WARMING FOR TEMPS TODAY. HIGHS SHOULD NOT CLIMB ABOVE THE UPPER
20S AFTER WE LOSE A FEW DEGREES THIS MORNING.
WE CONTINUE TO ANTICIPATE AN UPTICK IN LAKE EFFECT SNOW SHOWER
ACTIVITY FOR TONIGHT AND EARLY SAT MORNING. THIS UPTICK IS EXPECTED
TO BE THE RESULT OF A SHORT WAVE/PV ANOMALY CURRENTLY OVER NM THIS
MORNING LIFTING TO THE NE OVER THE AREA TONIGHT. INVERSION HEIGHTS
WILL BUMP UP TO AROUND 5K FEET OR SO. AT THE SAME TIME...A BIT OF
MID LEVEL MOISTURE WILL TRY TO HELP SNOW SHOWER GENERATION WITH A
SEEDER FEEDER TYPE OF SCENARIO. THERE WILL BE ABOUT 4-6K FT OF DRY
AIR IN BETWEEN THE LAYERS...SO IT IS NOT A GUARANTEE THIS WILL
ABSOLUTELY HELP. THE DGZ WILL BE SATURATED QUITE A BIT WHICH WILL
HELP FOR THE SNOW CAUSE. WNW FLOW FAVORED AREAS WILL SEE THE BEST
CHC OF SNOW SHOWERS AND SOME ACCUMULATIONS. LOW LEVEL CONVERGENCE IS
STILL LACKING...SO WE DO NOT EXPECT SNOW AMOUNTS TO GET OUT OF HAND.
WE WILL SEE THE LAKE EFFECT SNOW SHOWERS THEN GRADUALLY DIMINISH IN
COVERAGE AND INTENSITY DURING THE DAY ON SAT. THE NM SHORT WAVE WILL
EXIT THE AREA AND SUBSIDENCE WILL TAKE CONTROL ONCE AGAIN. INVERSION
HEIGHTS ARE EXPECTED TO LOWER TO AROUND 3K FEET...BEFORE LOW LEVEL
MOISTURE IS EXPECTED TO DISSIPATE WITH A STRONG ARCTIC SFC RIDGE
MOVING DIRECTLY OVERHEAD. THIS WILL ALLOW FOR A COLD SAT NIGHT WITH
SOME CLEARING LIKELY.
THE CLEARING AND BREAK IN THE SNOW SHOWERS WILL BE SHORT LIVED. WE
WILL SEE ADDITIONAL SHORT WAVE ENERGY EJECT OUT FROM THE WRN U.S.
TROUGH AND APPROACH THE AREA SUN AFTERNOON. SOME MOISTURE FROM THE
STRONG STORM SYSTEM EXPECTED ACROSS THE SE STATES WILL WRAP INTO
THIS WAVE AS IT IS PASSING ACROSS THE STATE. THE MOISTURE IS NOT
THAT RICH AS THE BEST MOISTURE WILL REMAIN WELL SE OF THE AREA WITH
THE MAIN BAROCLINIC/FRONTAL ZONE ACROSS THE SE PORTION OF THE
COUNTRY. FORCING IS LIMITED TOO THIS FAR NORTH WITH THE MAIN
ISENTROPIC ASCENT REMAINING WELL SOUTH AND EAST. THIS LOOKS LIKE A
LIGHT SNOW EVENT WHERE MOST OF THE AREA WILL SEE AN INCH OR TWO OF
SNOW ACCUMULATION.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 332 AM EST FRI DEC 6 2013
THE SYNOPTIC SYSTEM FOR SUNDAY NIGHT CONTINUES TO LOOK LESS
IMPRESSIVE WITH EACH MODEL RUN. WEAK/BAGGY SFC LOW PRESSURE PATTERN
PASSES ACROSS LOWER MI WITH ONLY AROUND ONE TENTH OF AN INCH OF QPF.
NO DECENT/AMPLIFIED SHORTWAVE IS PRESENT ALOFT...AND INSTEAD IT IS
JUST A SHEARED OUT/ELONGATED VORTICITY PATTERN.
THERE IS ALSO THE ISSUE OF A POTENTIAL MID LEVEL DRY SLOT SWEEPING
IN WHICH COULD LEAD TO MORE OF A LIGHT FREEZING RAIN/DRIZZLE THREAT
SUNDAY NIGHT RATHER THAN LIGHT SNOW. WILL KEEP LIKELY POPS FOR LIGHT
SNOW OVER THE ENTIRE AREA FOR NOW BUT IF THE TRENDS CONTINUE THEN
THE FREEZING PRECIP THREAT MAY NEED TO BE ADDED IN LATER FORECASTS.
COLD ADVECTION FOLLOWS ON MONDAY BEHIND THE WEAK EXITING SYSTEM BUT
THE REALLY COLD ARCTIC AIR DOES NOT ARRIVE UNTIL TUESDAY OR TUESDAY
NIGHT. IT IS THE CLIPPER SYSTEM TRACKING ACROSS LAKE SUPERIOR WHICH
BRINGS IN THE COLD AIR AND PERHAPS A BETTER RISK OF SOME
ACCUMULATING LAKE EFFECT SNOW. EVEN THIS IS QUESTIONABLE HOWEVER
SINCE THE CORE OF THE UPPER JET DOES NOT DIP SOUTH OF THE STATE AND
MOISTURE IS RATHER SHALLOW/LIMITED.
THE LAKE EFFECT SNOW SHOWER THREAT IS EXPECTED TO DIMINISH THURSDAY
AS SURFACE RIDGING BUILDS IN.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 658 AM EST FRI DEC 6 2013
MVFR CIGS AROUND 2500 FT AND A FEW LIGHT LAKE EFFECT SNOW SHOWERS
ARE ANTICIPATED TODAY. FOR THE MOST PART NO SIGNIFICANT LENGTHY
REDUCTIONS TO VSBYS ARE EXPECTED... BUT THERE MAY BE TIMES WHEN IT
DIPS DOWN TO 4-6 MILES. LAN AND JXN PROBABLY WILL NOT SEE THE MVFR
CIGS AND FLURRIES TODAY... BUT THEY COULD SPREAD INLAND TONIGHT.
KMKG AND KAZO MAY SEE SOME BETTER SNOW SHOWERS DEVELOPING LATER
TONIGHT WHICH COULD LOWER VSBYS POTENTIALLY INTO IFR CATEGORY AT
TIMES. DID NOT INCLUDE THIS THREAT IN THE TAFS YET HOWEVER AS
CONFIDENCE IS CURRENTLY TOO LOW.
&&
.MARINE...
ISSUED AT 332 AM EST FRI DEC 6 2013
WE ARE EXTENDING THE SMALL CRAFT ADVISORY FOR THE ENTIRE NEARSHORE
THROUGH 06Z SUN WITH THIS FCST PACKAGE. WINDS WILL COME DOWN TO
AROUND 15 TO 20 KNOTS TODAY AND REMAIN THERE THROUGH SAT. THE
ONSHORE FLOW AND UNSTABLE CONDITIONS WITH THE COLD AIR COMING IN
OVER THE LAKE WILL KEEP WAVES ABOVE 4 FEET THROUGH SAT. THERE SHOULD
BE A BREAK SAT NIGHT AND EARLY SUN.
&&
.HYDROLOGY...
ISSUED AT 332 AM EST FRI DEC 6 2013
THE ONLY CONCERN WITH HYDROLOGY REMAINS THE THREAT FOR ICE
DEVELOPMENT OVER THE NEXT WEEK. ARCTIC COLD AIR EXPECTED OVER THE
AREA THROUGH MOST OF THE NEXT WEEK WILL HELP ICE DEVELOPMENT. AS THE
ICE DEVELOPS...WE WILL BE MONITORING THE POTENTIAL FOR ICE JAMS TO
FORM.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR LMZ844>849.
&&
$$
UPDATE...WDM
SYNOPSIS...NJJ
SHORT TERM...NJJ
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...NJJ
MARINE...NJJ
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1008 AM EST FRI DEC 6 2013
.UPDATE...
THE THICK CANOPY OF MID/HIGH CLOUDS AND WEAK LOW LEVEL COLD AIR
ADVECTION THROUGH THE AFTERNOON WILL INHIBIT MUCH IF ANY DIURNAL
RESPONSE. THIS WILL SUPPORT A MINOR DOWNWARD ADJUSTMENT TO TEMPS
THIS AFTERNOON. THE DEPTH OF THE COLD AIR HAS BEEN INCREASING OVER
THE WESTERN GREAT LAKES WHICH IS LEADING TO A BETTER RESPONSE OFF
LAKE MI. THE 12Z DTX SOUNDING SHOWED A DEEP INVERSION BASED NEAR
920MB. THIS SHOULD ALLOW A GOOD DUCT FOR THE WESTWARD EXPANSION OF
LAKE STRATO CU. RAP SOUNDINGS ON BUFKIT SUGGEST SUPERSATURATION
WITH RESPECT TO ICE NEAR THE INVERSION LEVEL. SO IT SHOULD NOT BE
DIFFICULT TO GENERATE SOME FLURRIES FROM THESE LOWER BASED CLOUDS.
THIS WILL BE MORE PROBABLE ACROSS THE SAGINAW VALLEY AND THUMB
GIVEN THE WESTERLY FLOW. FARTHER SOUTH...THE LOW LEVEL FLOW
BECOMES HIGHLY DIVERGENT WHICH MAY KEEP THE LOW CLOUDS CONFINED TO
WRN LOWER MI THROUGH THE AFTERNOON.
&&
.AVIATION...ISSUED 646 AM EST FRI DEC 6 2013
//DISCUSSION...
DESPITE THE SURFACE FRONT PUSHED UP AGAINST THE APPALACHIAN CHAIN...A
GRADUAL SLOPE TO THIS FEATURE PLACES THE MIDLEVEL PORTION OF THE
FRONT OVER SOUTHEASTERN MICHIGAN. THIS BOUNDARY WILL PROVIDE PLENTY
IN THE WAY OF HIGH CLOUD TODAY. A WAVE IS EXPECTED TO RIDE ALONG THE
BOUNDARY REACHING THE AREA VERY LATE IN THE AFTERNOON AND EARLY
EVENING. DRY AIR IN THE LOW LEVELS AND A RELATIVELY HIGH AMOUNT OF
STABILITY WILL MAKE IT DIFFICULT TO SEE ANY PRECIPITATION. THE ONLY
POTENTIAL FOR ANY FLURRIES TO FALL WOULD BE KDTW/KYIP/KDET. BASES
WILL TRY TO LOWER WITH THIS FORCING...REMAINING AT OR ABOVE 4000 FT.
//DTW THRESHOLD THREATS...
* MEDIUM CONFIDENCE IN CEILINGS AT OR BELOW 5000 FT THIS AFTERNOON.
&&
.PREV DISCUSSION...ISSUED 356 AM EST FRI DEC 6 2013
SHORT TERM...TODAY AND TONIGHT
THE WEATHER FOR SOUTHEASTERN MICHIGAN WILL BE INFLUENCED BY A
BAROCLINIC ZONE THAT IS IN PLACE FROM THE EASTERN GREAT LAKES
THROUGH MUCH OF THE OHIO RIVER VALLEY. THE FRONTAL BOUNDARY WILL
BECOME QUASI-STATIONARY TODAY AS THE VERY STRONG...POLAR JET AXIS
OVERHEAD BECOMES FAIRLY STATIC. CHARACTERISTICS OF THE FRONT OFFERED
BY CROSS SECTIONS ARE: 1. GRADUALLY SLOPED 2. A DOUBLE GRADIENT
STRUCTURE AT ROUGHLY 750 MB AND 550 MB.
A WAVE IS EXPECTED TO RIPPLE ALONG THE BAROCLINIC ZONE LATE THIS
AFTERNOON AS A LOWER TROPOSPHERIC REFLECTION OF RIGHT ENTRANCE
REGION DYNAMICS. OVERALL PRECIPITATION CHANCES WILL BE NEAR ZERO FOR
MUCH OF THE CWA WITH CHANCES VERY LOW ACROSS MONROE COUNTY. THE
REASON IS ANALYSES OF LOW TO MID TROPOSPHERIC -DIV AND DEFORMATION
ADVERTISE VERY LITTLE FORCING. IN ADDITION...CROSS SECTIONS SUPPORT
SUBSIDENCE THIS AFTERNOON BETWEEN THE 750 MB AND 550 MB GRADIENTS
ALONG WITH RELATIVELY HIGH STATIC STABILITY THROUGH A GOOD CHUNK OF
THE COLUMN. A DRY LAYER BELOW THE 750MB GRADIENT WILL PROVIDE AN
EVAPORATION BUFFER. IN THE SPIRIT OF CONTINUITY...CONTINUED TO
INCLUDE A LOW CHANCE POP OF LIGHT SNOW FOR MONROE COUNTY BETWEEN
21-02Z BUT ANY SNOWFALL...IF ANY...WILL BE NEGLIGIBLE. SOME FORCING
VERY HIGH IN COLUMN IS STILL EXPECTED TO OVERLAP SOUTHEASTERN
MICHIGAN WHICH SHOULD PROVIDE AN ABUNDANCE OF HIGH CLOUD FOR MUCH OF
THE DAYLIGHT HOURS.
SLUGGISH MOVEMENT OF THE FRONT TODAY WILL GIVE SOME POTENTIAL AT
AFTERNOON HIGHS DESPITE THE CLOUDS. FREEZING MARK SOUTH...TO MIDDLE
20S NORTH. WIND CHILLS WILL DROP INTO THE TEENS THIS MORNING...THEN
STRUGGLE TO CLIMB ABOVE 20 FOR THE AFTERNOON. SUBSIDENCE OCCURRING
BEHIND THE WAVE LATE TONIGHT ALONG WITH DRY AIR SHOULD ALLOW CLOUDS
TO SCATTER AN HOUR OR TWO BEFORE SUNRISE. TEMPERATURES WILL HAVE THE
POTENTIAL TO DROP...LOWS IN THE TEENS WIND CHILLS IN THE SINGLE
DIGITS FOR ALL OF SOUTHEASTERN MICHIGAN.
LONG TERM...SATURDAY THROUGH THURSDAY
HIGH AMPLITUDE MID LEVEL FLOW ANCHORED BY A SPRAWLING LONGWAVE
TROUGH WILL REMAIN THE CONTROLLING LARGE SCALE FEATURE WELL INTO
NEXT WEEK. THE WEEKEND BEGINS WITH SE MICHIGAN INITIALLY RESIDING
ALONG THE EASTERN EXTENSION OF THE MAIN HEIGHT FALL CENTER AND WELL
WITHIN THE COLD DOME PERPETUATED BY AN INBOUND 1040 MB ARCTIC HIGH.
AMBIENT AIRMASS WILL CARRY A DEEP DRY LAYER ABOVE 900 MB...WHILE A
CHECK OF UPSTREAM SOUNDINGS ACROSS LAKE MICHIGAN SHOW A PROFILE ALSO
LACKING IN MOISTURE DEPTH WITH SUPPRESSED INVERSION HEIGHTS. THIS
WOULD INDICATE THE OPPORTUNITY FOR A LAKE AND/OR DIURNALLY ENHANCED
STRATOCU FIELD WILL BE LIMITED. SOME LINGERING EARLY STRATUS MAY
EXIST...PARTICULARLY ACROSS THE NORTH WITH THE RESIDUAL MOISTURE
SOURCE FROM TODAY PERHAPS SLOWER TO MIX OUT. MAIN STORY WILL BE
TEMPERATURES...WITH EVEN A HIGH DEGREE OF INSOLATION STRUGGLING TO
MODERATE A THERMAL PROFILE CARRYING 925 MB TEMPERATURES IN THE -11
TO -12C RANGE. THIS WILL TRANSLATE INTO HIGHS OF LOWER TO MIDDLE
20S...OR A GOOD 15 DEGREE BELOW EARLY DECEMBER NORMS. THE EXISTING
SURFACE RIDGING AND DEEP DRY LAYER WILL PROMOTE A GOOD RADIATIONAL
COOLING RESPONSE SATURDAY NIGHT. A GRADUALLY INCREASING CIRRUS
SHIELD WILL BE THE ONE POSSIBLE DISRUPTION TO REALIZING THE FULL
POTENTIAL. OVERALL STILL LOOKING AT LOWS IN THE TEENS...A FEW
SINGLE DIGIT READINGS NOT OUT OF THE QUESTION IN THE COLDEST
LOCALES.
CONDITIONS INTO SUNDAY REMAIN DEFINED BY THE PRESENCE OF A COLD/DRY
ENVIRONMENT...LOW LEVEL FLOW FLIPPING TO EASTERLY WITH THE ARCTIC
HIGH SLOWLY EASING EASTWARD. HIGHS AGAIN IN THE 20S...EFFECTIVELY
CONTAINED BY A MORE CONCERTED INCREASE IN HIGH CLOUD. FOCUS INTO
SUNDAY EVENING/NIGHT THEN TURNS TO A WELL DEFINED PV ANOMALY WORKING
THROUGH THE TROUGH BASE. THIS WAVE WILL SHEAR INTO THE PREVAILING
SOUTHWESTERLIES ORIENTED FROM THE CENTRAL PLAINS INTO THE GREAT
LAKES THROUGH THE LATTER HALF OF THE WEEKEND. THIS PROCESS WILL
PROMPT TWO AREAS OF FOCUS...ONE WITHIN A WING OF EMERGING ISENTROPIC
ASCENT AND MOISTURE TRANSPORT ORIGINATING OUT OF THE WESTERN
GULF...AND A SECOND ACCOMPANYING THE PRIMARY REGION OF FORCED ASCENT
CONTAINED WITHIN THE MAIN HEIGHT FALL CENTER AND ALONG THE
DEVELOPING WEAK SURFACE WAVE AND FRONTAL CIRCULATION EJECTING OUT OF
THE PLAINS. THE OVERALL UPPER JET POSITIONING WOULD TEND TO DIRECT
THE BULK OF THE GULF ORIGINATING MOISTURE AND ATTENDANT WEAK ASCENT
TO OUR SOUTHEAST. IT REMAINS PLAUSIBLE FOR SOUTHERN SECTIONS OF
SOUTHEAST MICHIGAN TO RECEIVE A GLANCING SHOT ALONG THE WESTERN EDGE
SUNDAY EVENING. WEAK SURFACE WAVE THEN LIFTS THROUGH LOWER MICHIGAN
SUNDAY NIGHT...DISPLACED SOUTHEAST OF THE MAIN STRIPE OF DCVA AND
DEFORMATION FORCING SHIFTING FROM THE UPPER MS VALLEY INTO THE U.P.
THIS WILL LEAVE SE MICHIGAN UNDER A BROADER LOOKING PERIOD OF
FORCING...STILL SUFFICIENT TOWARD GENERATING A FEW HUNDREDTHS OF QPF
SUNDAY NIGHT. A SUB-FREEZING THERMAL PROFILE THROUGHOUT WILL
SUPPORT ALL SNOW...ALTHOUGH THE PROFILE WILL BE WARMING WITH
TIME...EFFECTIVELY REDUCING POTENTIAL SNOWFALL RATIOS.
A GENERAL EASTWARD MIGRATION OF THE MEAN LONGWAVE TROUGH WILL DIRECT
A SERIES SHORTWAVES OF SIBERIAN ORIGIN THROUGH THE GREAT LAKES
DURING THE EARLY AND MID WEEK PERIOD. THIS WILL RESULT IN AN
EXTENDED STRETCH OF WELL BELOW NORMAL TEMPERATURES AS ARCTIC AIR
TAKES FIRM RESIDENCE THROUGHOUT THE WEEK.
MARINE...
WESTERLY WINDS WILL DIMINISH SLIGHTLY TODAY AND TONIGHT AS THE
PRESSURE GRADIENT EASES BEHIND LOW PRESSURE LIFTING INTO QUEBEC.
THIS WILL RESULT IN A LOWER WAVE CONDITIONS THROUGH THIS TIME.
COLDER AIR MOVING ACROSS THE WATERS WILL MAINTAIN WIND SPEEDS IN
THE 15 TO 20 KNOT RANGE ACROSS NORTHERN PORTIONS OF LAKE HURON.
SLIGHT INCREASE IN WINDS EARLY SATURDAY WILL BRING GUSTS JUST SHY
OF GALES ACROSS NORTHERN LAKE HURON. STRONG HIGH PRESSURE WILL
THEN TAKE CONTROL SATURDAY NIGHT AND SUNDAY.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SC
AVIATION.....CB
SHORT TERM...CB
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
952 PM CST Sat Dec 7 2013
.UPDATE:
Issued at 944 PM CST Sat Dec 7 2013
Several narrow snow bands have developed this evening across
southwest Missouri in an area of strong mid level frontogenetical
forcing and low/mid level warm advection ahead of a short wave
moving through the southern plains. Snow is reaching the ground in
and there are areas that have a dusting. The latest RAP and HRRR
runs increase the forcing and shift it northeastward parallelling
I-44 during the overnight hours and into the St. Louis metro area.
This seems reasonable based on observed trends. The only question
is the coverage and whether a wider more solitary band will evolve
or whether it will remain with several narrow bands. At this time
I have increased the pops within this corridor but only mentioned
scattered snow showers due to the uncertainty in the coverage
evolution. Some areas could certainly pick up a dusting to half
inch beneath them. If the coverage expands I will probably need to
boost pops into the likely category before the evening is over.
Glass
&&
.SHORT TERM: (Through Sunday Evening)
Issued at 301 PM CST Sat Dec 7 2013
Strong shortwave dipping into the base of the upper level trof
across the western CONUS will move across the Four Corners tonight
and emerge into the Plains on Sunday morning. Impressive warm
advection forecast to develop ahead of the shortwave with light qpf
noted on all model guidance to march northeast across the CWA from
late tonight through Sunday afternoon. Believe this is one of those
high PoP/low QPF events. Precipitation type is not clear cut...as
lack of ice crystal formation is noted on model soundings. I also
note that there is a steady stream of mid and high level clouds
streaming northeast from Texas. Wonder if the ice crystals from the
higher clouds will lead to a seeder/feeder situation, ultimately
allowing the precipitation to fall as more snow or snow grains
rather than freezing drizzle late tonight and tomorrow morning.
Tomorrow afternoon the best lift will be moving northeast and the
lower atmosphere will be warming so precipitation will likely turn
to areas of freezing drizzle that may continue into the evening.
Overall believe snowfall amounts will remain under an inch and any
freezing drizzle will only produce a light glaze. Will let the
evening and overnight shifts take a look at the 00Z model data to
determine the need, if any, for headlines on Sunday.
CVKING
.LONG TERM: (Sunday Night through Next Saturday)
Issued at 301 PM CST Sat Dec 7 2013
Cold front will progress southeast across the CWA late Sunday
night, reinforcing the cold for the beginning of the work week.
Next shortwave moves into the Plains Monday night an CWA will be in
a favorable area of synoptic lift provided by the right entrance
region of the jet streak to our northeast. This may ultimately
provide another chance of light snow south of Interstate 70. Have
kept slight chance PoPs at this time.
Extended forecast remains dry and cold with cold front passages
Wednesday and Friday.
CVKING
&&
.AVIATION: (For the 00z TAFs through 00z Sunday Evening)
Issued at 541 PM CST Sat Dec 7 2013
Some minor changes in timing to the prev TAFs, but focus remains
the approaching precip. Latest guidance suggests precip will begin
as SN as it moves in from W to E thru the region. This event still
appears to be a high probability, low precip event. By late
morning into the afternoon Sun, the top of the cloud deck will
start to erode, removing ice crystals, changing the precip over
to FZDZ. A lot of uncertainty remains as to when this change will
occur and how long the FZDZ will linger into the afternoon. Cigs
shud remain in the low end MVFR cat thru much of the afternoon.
However, cigs shud drop quickly into IFR cat around sunset as the
atmo cools.
Specifics for KSTL: Only some minor changes to timing of different
cloud deck arrivals. Did introduce FZDZ Sun afternoon with
increased confidence of occurrence. However, timing of onset of SN
and then change over to FZDZ remains uncertain. IFR cigs are
expected as or shortly after precip ends.
Tilly
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION...CORRECTED
NWS WILMINGTON NC
630 PM EST SAT DEC 7 2013
.SYNOPSIS...
DAMP AND CHILLY WEATHER WILL PERSIST INTO SUNDAY NIGHT BEFORE A WARM
FRONT BRINGS A SHORT-LIVED WARMUP MONDAY. A COLD FRONT WILL MOVE
THROUGH TUESDAY BRINGING ANOTHER ROUND OF COOLER WEATHER WEDNESDAY
THROUGH NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 630 PM SATURDAY...THE SURFACE COLD FRONT IS IN THE PROCESS OF
STALLING NEAR THE SOUTH CAROLINA/GEORGIA BORDER. OVER WILMINGTON THE
COLD AIRMASS IS ABOUT 3000 FEET DEEP...ABOVE WHICH WINDS ARE STILL
FROM THE SOUTHWEST AND ORIGINATE FROM THE CENTRAL GULF OF MEXICO.
MODELS DIFFER ON THE DEGREE OF ISENTROPIC LIFT OVER THE FRONTAL
SURFACE TONIGHT. THE GFS IS THE MOST BULLISH WITH THIS LIFT ALONG
THE 295-305K SURFACES (3500-9000 FT AGL) WHILE THE RUC SHOWS THE
LEAST AMOUNT OF LIFT. ALL MODELS CRANK OUT AT LEAST A FEW HUNDREDTHS
OF AN INCH OF RAIN AREA-WIDE. RECENT RADAR LOOPS SHOW QUITE A BIT OF
RAIN UPSTREAM ACROSS CENTRAL AND SOUTHERN SOUTH CAROLINA...THEREFORE
I HAVE RAISED FORECAST POPS FOR THE OVERNIGHT PERIOD TO 80-90
PERCENT FOR ALL BUT THE SOUTH CAROLINA BEACHES AND AREAS NEAR THE
SANTEE RIVER. CLOUD DEPTH SHOULD BE SUFFICIENT WITH CLOUD BASES LOW
ENOUGH TO GUARANTEE OCCASIONAL DRIZZLE EVEN WHEN MEASURABLE RAIN IS
NOT FALLING. COMPARED TO THE PAST SEVERAL DAYS OF SUBTROPICAL
WEATHER...TONIGHT`S WEATHER IS A HARSH REMINDER OF THE ACTUAL DATE
ON THE CALENDAR.
AIRMASS ADVECTION IS THE ONLY FACTOR TO CONSIDER FOR LOWS SINCE
DENSE CLOUD COVER WILL NEGATE ANY RADIATIONAL COOLING EFFECTS.
PREVIOUS FORECAST LOWS RANGING FROM THE UPPER 30S WEST OF I-95 TO
THE MID 40S AT THE BEACHES LOOK REASONABLE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...A DARK AND DREARY SUNDAY ON TAP AS SHALLOW
WEDGE OF CHILLY AIR REMAINS ENTRENCHED ALONG THE EAST FACE OF THE
APPALACHIANS. HIGH TEMPERATURES WILL REMAIN STUCK IN THE 40S YET IT
WILL BE 60 DEGREES 2500 FT ABOVE THE SURFACE. THE BASE OF THIS
IMPRESSIVE INVERSION WILL BE AT ABOUT 600FT...WHICH IS THE LEVEL AT
WHICH THE STRATUS DECK WILL BE FOUND. MODELS SHOWING THAT THE WARM
AIR RIDING OVER THE WEDGE LEADS TO SOME ISENTROPIC UPGLIDE AND
POSSIBLY SOME LIGHT RAINFALL BUT MOST OF BOTH SHOULD REMAIN TO OUR
NORTH. THE WEDGE BREAKS DOWN SURPRISINGLY QUICKLY LATE SUNDAY NIGHT
INTO MONDAY AND THE WARM AIR ALOFT MENTIONED EARLIER WILL MIX TO THE
SURFACE AND BRING A MUCH WARMER AFTERNOON. MODELS HOLDING ON TO RAIN
CHANCES...WHICH SEEMS PLAUSIBLE ENOUGH MONDAY MORNING AS WARM FRONT
LIFTS THROUGH. MONDAY NIGHT ALSO BRINGS SOME CHANCE FOR RAIN AS THE
NEXT COLD FRONT APPROACHES SLOWLY...BEING WELL ALIGNED WITH THE FLOW
ALOFT. IN BETWEEN MONDAY AFTERNOON SHOULD BRING A RELATIVE MINIMUM
IN RAIN CHANCES.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
AS OF 3 PM SATURDAY...COLD FRONT WILL BE IN THE AREA AT THE START OF
THE PERIOD...THOUGH THE TIMING OF ITS PASSAGE REMAINS IN QUESTION.
ECMWF/CANADIAN HAVE A FAST SOLUTION WITH THE GFS ON THE SLOW SIDE
AND NAM IN BETWEEN. THE MID LEVEL PATTERN...BROAD TROUGHING WITH THE
TROUGH AXIS TO THE WEST...MEANS FLOW WILL BE ALIGNED ALONG THE
BOUNDARY WHICH WOULD SUPPORT SLOWER BOUNDARY MOVEMENT. AT THIS POINT
WILL TREND TO THE SLOWER SOLUTION BUT NOT DRASTICALLY...MORE OR LESS
IN LINE WITH THE NAM.
MID LEVEL PATTERN STARTS TO BECOME MORE PROGRESSIVE DURING THE
MIDDLE OF NEXT WEEK PUSHING THE BOUNDARY FARTHER OFF THE COAST AND
MOVING ARCTIC HIGH IN FROM THE WEST. THE BRUNT OF THE COLD ADVECTION
REMAINS NORTH OF THE AREA BUT TEMPERATURES STILL DROP 5-10 DEGREES
BELOW CLIMO BEHIND THE FRONT. SURFACE HIGH SHIFTS OFF THE COAST FRI
WITH WEAK COASTAL TROUGH DEVELOPING LATER IN THE DAY AND BECOMING
MORE DEFINED SAT. AS IS USUALLY THE CASE WITH A COASTAL TROUGH THERE
WILL BE THE POTENTIAL FOR DEVELOPMENT OF WEAK SURFACE WAVE ALONG IT
AS THE PERIOD ENDS. TEMPERATURES RETURN NEAR CLIMO FOR THE END OF
THE PERIOD...THOUGH THE INCREASE IN TEMP WILL BE ACCOMPANIED BY AN
INCREASE IN POP.
&&
.AVIATION /00Z SUNDAY THROUGH WEDNESDAY/...
AS OF 00Z...POST FRONTAL MVFR/IFR CIGS PREVAIL THIS EVENING AS THE
COLD FRONT NOW LIES OFFSHORE OF THE CAROLINAS. THE LOWEST CIGS ARE
BEING REPORTED AT KILM/KCRE/KMYR...WHERE IFR HAS LINGERED THROUGH
THE DAY. CIGS COULD BRIEFLY LIFT ABOVE 1KFT TONIGHT ALONG THE
COAST...BUT GUIDANCE AND FCST SOUNDINGS SUPPORT PREVAILING IFR
STRATUS WITH THE COLD AIR WEDGE IN PLACE. KFLO/KLBT SHOULD SEE MVFR
CIGS TONIGHT LOWER TO IFR AFTER 06Z. RADAR RETURNS INDICATE PERIODS
OF -RA/DZ ARE LIKELY TONIGHT AS WELL...REDUCING VSBYS TO MVFR/IFR AT
TIMES. NORTHEAST WINDS 10-15 KTS WILL PERSIST THROUGH THE PERIOD...
WITH A FEW GUSTS AOB 20 KTS POSSIBLE TONIGHT. MODEL SOUNDINGS DEPICT
THE COLD WEDGE LOCKED IN PLACE THROUGH SUNDAY...SO STRATUS WILL
LIKELY PLAGUE ALL TAF SITES WITH IFR/LIFR CIGS INTO THE AFTN AND
EVENING HOURS.
EXTENDED OUTLOOK...UNSETTLED WEATHER THROUGH THE EXTENDED PERIOD
WITH IFR/MVFR CONDITIONS DUE TO A NEARLY STATIONARY FRONT. SHOWERS
LIKELY TUESDAY WITH ANOTHER COLD FRONT.
&&
.MARINE...
NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 630 PM SATURDAY...THE COLD FRONT HAS STALLED NEAR THE SOUTH
CAROLINA/GEORGIA BORDER AND SHOULD REMAIN THERE THROUGH THE NIGHT.
ARCTIC HIGH PRESSURE OVER MINNESOTA WILL PUSH CHILLY NORTH TO
NORTHEAST WINDS ACROSS THE AREA TONIGHT...WITH SUSTAINED WIND SPEEDS
20-25 KNOTS EXPECTED. RECENT GUSTS OUT AT THE FRYING PAN SHOALS BUOY
HAVE REACHED 27 KNOTS...WITH 22 KNOTS AT WRIGHTSVILLE BEACH AND 21
KNOTS AT MYRTLE BEACH. SEAS HAVE BUILT TO 6 FEET AT FRYING PAN AND 4
FEET AT THE CAPE FEAR RIVER HARBOR BUOY...WITH ANOTHER 1 FOOT
INCREASE POSSIBLE BY MIDNIGHT BEFORE SEA HEIGHTS MAX OUT. DRIZZLE
WITH PATCHES OF LIGHT RAIN WILL CONTINUE THROUGH THE NIGHT.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 PM SATURDAY...CHILLY WEDGE OF HIGH PRESSURE OVER THE
LANDMASS ON SUNDAY TO PINCH GRADIENT EARLY ON. FLAT WAVE OF LOW
PRESSURE OFFSHORE TO EASE THE GRADIENT SOME AS THE DAY WEARS ON.
AS WIND AND SEAS RELAX THE SMALL CRAFT ADVISORY/6FT SEAS SHOULD
ABATE...POSSIBLY A BIT BEFORE THE CURRENT EXPIRATION TIME OF 17Z.
SCEC HEADLINES MAY BE NEEDED BUT PROBABLY ONLY BRIEFLY AS THE
MARINE GRADIENT CONTINUES TO WEAKEN EVEN AS IT HOLDS FAST OVER
LAND. NOT SO SUNDAY NIGHT INTO MONDAY HOWEVER AS THE SHALLOW WEDGE
THEN WEAKENS RATHER QUICKLY. THIS ALLOWS THE FLOW TO TURN AROUND
TO S OR SW WHILE SPEEDS REMAIN GENERALLY CAPPED AT 10 TO 15KT.
LONG TERM /TUESDAY THROUGH THURSDAY/...
AS OF 3 PM SATURDAY...PASSAGE OF COLD FRONT LATE TUE WILL CAUSE
WINDS TO VEER FROM SOUTHWEST TO WEST-NORTHWEST TUE NIGHT. AHEAD OF
THE FRONT GRADIENT WILL PRODUCE WINDS IN THE 15 TO 20 KT RANGE WITH
LIMITED GUST POTENTIAL GIVEN COOLER WATER TEMPS. POST FRONT COLD
ADVECTION IS SLOW TO DEVELOP SO OFFSHORE FLOW TUE NIGHT WILL
INITIALLY BE ON THE WEAK SIDE. AROUND DAYBREAK OR SO NORTHERLY FLOW
START TO INCREASE AS THE COLD AIR ARRIVES. SPEEDS WED AND THU WILL
BE 15 TO 20 KT. OCCASIONAL COLD SURGES COULD PUSH WINDS OVER 20 KT
FOR BRIEF PERIODS OF TIME.
SEAS WELL AWAY FROM SHORE WILL FLIRT WITH 6 FT FOR A MAJORITY OF THE
PERIOD. SOUTHWEST FLOW AHEAD OF THE FRONT WILL PUSH SEAS TO 3 TO 5
FT WITH POTENTIAL FOR HIGHER SEAS IN PLACES. ONCE THE FRONT PASSES
THE ABRUPT WIND SHIFT WILL CREATE A CHAOTIC SEA STATE THOUGH SEAS
WILL START TRENDING DOWN. THE DOWNWARD TREND ENDS WED MORNING AS
COLDER AIR ARRIVES AND WINDS INCREASE...NOW FROM THE NORTH. SEAS
RANGING FROM 2 FT NEAR SHORE TO 6 FT NEAR 20 NM WILL BE POSSIBLE WED
AND THU.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SUNDAY FOR AMZ250-252-254-
256.
&&
$$
NEAR TERM...TRA
SHORT TERM...MBB
LONG TERM...III
AVIATION...BJR
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
658 AM EST FRI DEC 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TODAY AS A COLD FRONT APPROACHES
FROM THE WEST TONIGHT AND WILL CROSS THE REGION ON SATURDAY AFTERNOON.
A STRONGER COLD FRONT WILL CROSS THE REGION TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 655 AM FRIDAY...TEMPERATURES HAVE REMAINED IN THE MID 60S TO
AROUND 70 THIS MORNING GIVEN A SOUTHWEST WINDS AT 7 TO 11 KNOTS. GIVEN
THIS WARM START...MAXIMUM TEMPERATURES TODAY SHOULD BE ABLE TO
REACH THE UPPER 70S TO LOW 80S WELL INLAND WITH LOW TO MID 70S
ALONG THE IMMEDIATE COAST. THINK RECORD LOWS MAY BE THREATENED AT
LOCATIONS SUCH AS GREENVILLE AND PERHAPS KINSTON LATER
TODAY...DESPITE FAIRLY THICK MID AND HIGH LEVEL CLOUDINESS. LATEST
HIGH RESOLUTION WRF AND RAP MODELS KEEP PRECIPITATION TO THE WEST
AND NORTH OF THE CWA TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS OF 325 AM FRIDAY...COLD FRONT WILL APPROACH THE REGION FROM THE
WEST LATER TODAY. BEST LOW-LEVEL MOISTURE TRANSPORT DOES NOT
ARRIVE IN OUR NORTHERN COUNTIES UNTIL AFTER MIDNIGHT AND WILL
SLOWLY RAMP POPS UP WITH CHANCE THRU THE LATE EVENING TO LIKELY
OVER NORTHERN COUNTIES BY LATE TONIGHT. QPF TOTALS THROUGH TONIGHT
DO NOT LOOK TO BE PARTICULARLY HEAVY...GENERALLY AT ONE-TENTH OF
AN INCH OR LESS. TEMPERATURES WILL VERY FROM THE MID TO UPPER 50S
ALONG THE FRONT OVER THE NORTHERN COUNTIES...TO THE MILD LOW AND
MID 60S AHEAD OF THE FRONT OVER THE SOUTHERN TWO-THIRDS OF THE
COUNTY WARNING AREA.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 330 AM FRI...MODELS CONTINUE IN GOOD AGREEMENT ON PUSHING A
SURFACE COLD FRONT THROUGH EASTERN NC SAT MORNING WITH TEMPS
WARMEST IN THE MORNING AND SLOWLY FALLING THROUGHOUT THE DAY DUE
TO CLOUDS AND PRECIP OVERSPREADING THE REGION FROM NW TO SE. THERE
WILL BE A LARGE GRADIENT BETWEEN HEIGHTS/THICKNESSES FROM THE
COASTAL PLAIN COUNTIES TO THE COAST...WITH TEMPS FALLING INTO THE
50S BEHIND THE FRONT. FRONTAL BOUNDARY WILL BE AN ANAFRONT WITH
CLOUD/PRECIP BEHIND THE FRONT. THE UPPER TROUGH WILL REMAIN
CENTERED OVER THE CENTRAL/WESTERN CONUS AS A STRONG RIDGE ALOFT
REMAINS CENTERED OVER FLORIDA...PLACING EASTERN NC IN SW FLOW
ALOFT THROUGH EARLY IN THE WEEK. A STRONG FRONTAL INVERSION WILL
BE PRESENT SAT THROUGH SUN AS 850MB WINDS REMAIN SW WITH NLY
SURFACE WINDS. THIS WILL PRODUCE WIDESPREAD RAIN AND LOW CLOUDS
THROUGH EARLY SUN MORNING. COOLER TEMPS EXPECTED ON SUNDAY DUE TO
CLOUDS/PRECIP WITH HIGHS IN THE 40S INLAND TO 50S ALONG THE COAST.
LATEST GUIDANCE CONTINUES TO INDICATE A COASTAL TROUGH DEVELOPING
SUN AFTERNOON...WHICH BECOMES A WEAK LOW THAT MOVES NNE ALONG THE NC
COAST SUN NIGHT. AS THE LOW MOVES NE OF THE AREA LATE SUN NIGHT/EARLY
MON MORNING...COLD AIR DAMMING SCENARIO WILL SHIFT NW OF THE REGION
AS SW RETURN FLOW TAKES OVER WITH EASTERN NC AGAIN IN THE WARM
SECTOR.
UPPER RIDGE WILL STRENGTHEN AGAIN MON WITH HIGH TEMPS EXPECTED
BACK INTO THE 70S UNDER PARTLY SUNNY SKIES. LOW LEVEL THICKNESSES
BUILD 1385-1390 METERS RANGE...BUT MIXED CLOUDS MAY INHIBIT FULL
INSOLATION SO HELD TEMPS IN THE LOW 70S INLAND TO UPPER 60S
OBX...ALTHOUGH GREATER BREAKS IN CLOUD COVER COULD MEAN TEMPS
REACHING A FEW DEGREES HIGHER THAN CURRENTLY FORECAST.
ANOTHER COLD FRONT WILL PASS THROUGH EASTERN NC EARLY TUES MORNING
BRINGING MORE UNSETTLED WEATHER WITH RAIN AGAIN MOSTLY POST-
FRONTAL AND CONTINUING INTO TUES EVENING BEFORE STRONG HIGH PRESSURE
OVER THE CENTRAL CONUS SHIFTS EAST OVER THE MID-ATLANTIC REGION.
WED/THURS WILL BE DRY AND MUCH COOLER WITH TEMPS STRUGGLING TO
BUILD INTO THE MID 40S DUE TO STRONG COLD AIR ADVECTION IN NLY FLOW.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 655 AM FRIDAY...WITH A LIGHT SOUTHWEST WINDS AT 7 TO 11
KNOTS CONTINUING OVERNIGHT...FOG HAS NOT DEVELOPED AT THE TAF
SITES THIS MORNING. EXTENSIVE MID AND HIGH LEVEL CLOUDINESS WILL
PERSIST THROUGH THE DAY. WINDS GUSTING BETWEEN 15 AND 20 KNOTS ARE
POSSIBLE LATER IN THE DAY IN ADVANCE OF AN APPROACHING COLD FRONT.
NUMERICAL GUIDANCE AGAIN INDICATES PATCHY DENSE FOG LATE TONIGHT...BUT
WITH CONTINUE LIGHT TO MODERATE SW WINDS...AGAIN WILL BE LIMITED
IN SCOPE AND WILL FORECAST JUST MVFR STRATUS AT THIS TIME.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 335 AM FRI...A COLD FRONT WILL APPROACH FROM THE NW FRI
NIGHT...MOVING THROUGH THE TERMINALS SAT MORNING. MODEL SOUNDINGS
INDICATE A PROLONGED PERIOD OF MVFR/IFR CONDITIONS EXPECTED TO
DEVELOP LATE FRI NIGHT AND CONTINUE THROUGH MUCH OF SUNDAY...WITH
WIDESPREAD RAIN ALSO DEVELOPING THIS WEEKEND. N/NE WIND GUSTS
15-20KT EXPECTED BEHIND THE FRONT SAT AFTERNOON. A WEAK LOW OFF
THE COAST WILL PUSH NE THROUGH THE AREA SUN NIGHT WITH SW FLOW
TAKING OVER MON WITH PRECIP CHANCES DIMINISHING AND LOWER CIGS
LIFTING N OF THE REGION THOUGH FOG MAY BE A POSSIBILITY AT NIGHT.
ANOTHER COLD FRONT CROSS THE TERMINALS FROM NW TO SE TUES WITH
ANOTHER ROUND OF MVFR/IFR CONDITIONS POSSIBLE IN LOWERED
CEILINGS/VSBYS THROUGH TUES. HIGH PRESSURE BUILDS OVER THE REGION
TUES NIGHT WITH CONDITIONS IMPROVING TO VFR.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 655 AM FRIDAY...BASED ON CURRENT OBSERVATIONAL TRENDS...HAVE
UPPED WINDS TO 15 T0 20 KNOTS ON THE COASTAL WATERS NORTH OF CAPE
LOOKOUT. HAVE ALSO ADDED THE PAMLICO SOUND TO THE SMALL CRAFT
ADVISORY WHICH WILL BEGIN AT 03Z TONIGHT WITH GUSTY SW WINDS
EXPECTED. SEAS REMAIN IN THE 2 TO 3 FOOT RANGE...BUT PER LOCAL
NWPS/SWAN MODEL AND WAVEWATCH GUIDANCE...SEAS WILL BUILD TO AS
HIGH AS 6 FEET BY LATE THIS EVENING AND TONIGHT.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 345 AM FRI...SCA CONDITIONS WILL PERSIST OVER THE WATERS
THROUGH THE WEEKEND AS SW WINDS INCREASE TO 20 KT OR HIGHER WITH
SEAS REACHING 6 FT FOR THE OUTER CENTRAL/SOUTHERN WATERS. FRONT
WILL PASS THROUGH THE WATERS BY MIDDAY SAT WITH NORTHERLY CAA
SURGE INCREASING WINDS TO 20 KNOTS WITH SEAS 5-7 FT THROUGH SUN
MORNING. MODELS IN AGREEMENT WITH A WEAK INVERTED/COASTAL TROUGH
OVER THE SOUTHERN/CENTRAL WATERS SUN AFTERNOON WHICH DEVELOPS INTO
A WEAK SURFACE LOW AND MOVES NNE ALONG THE NC COAST SUN NIGHT.
SURFACE WINDS WILL BECOME SW ONCE THE WEAK LOW LIFTS NORTH OF THE
WATERS LATE SUN NIGHT. WINDS AND SEAS BRIEFLY SUBSIDE BELOW SCA
CRITERIA MON MORNING WITH SW WINDS 10-15 KT AND SEAS 3-5 FT...THEN
INCREASE TO 15-20 KT AND SEAS 4-7 FT AS THE GRADIENT TIGHTENS
BETWEEN SURFACE RIDGE OFF THE SOUTHEASTERN COAST AND A COLD FRONT
APPROACHING FROM THE NW. SCA CONDITIONS EXPECTED MON AFTERNOON
LASTING THROUGH AT LEAST TUES. WAVEWATCH III AND LOCAL SWAN/NWPS
IN GOOD AGREEMENT THROUGH THE LONG TERM.
&&
.CLIMATE...
RECORD HIGH (79) WAS SET IN NEW BERN ON THURSDAY AND MORE RECORD
WARMTH LIKELY ON FRIDAY.
BELOW IS A SUMMARY OF THE
CLIMATOLOGICAL RECORD HIGH TEMPERATURES FOR FRIDAY...DECEMBER 6TH:
RECORD HIGH FOR DEC 6:
NEW BERN 81 (1998)
GREENVILLE 80 (1998)
KINSTON 81 (1982)
NEWPORT 77 (1998)
BAYBORO 82 (1998)
MOREHEAD CITY 74 (2011)
WILLIAMSTON 76 (1998)
CAPE HATTERAS 77 (1982)
OCRACOKE 73 (1975)
MANTEO 78 (1998)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 AM EST
SUNDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
SUNDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...DAG
AVIATION...CTC/DAG
MARINE...CTC/DAG
CLIMATE...CTC
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
347 AM EST FRI DEC 6 2013
.SYNOPSIS...
HIGH PRESSURE WILL MOVE OFFSHORE TODAY AS A COLD FRONT APPROACHES
FROM THE WEST TONIGHT AND WILL CROSS THE REGION ON SATURDAY AFTERNOON.
A STRONGER COLD FRONT WILL CROSS THE REGION TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 320 AM FRIDAY...WITH A S/SSW WIND OF ABOUT 7 OR 8 KNOTS
LINGERING...TEMPERATURES ARE VERY MILD FOR BOTH THIS TIME OF YEAR
AND THIS TIME OF NIGHT...HOVERING IN THE MID TO UPPER 60S AREA-
WIDE. GIVEN THIS WARM START...MAXIMUM TEMPERATURES TODAY SHOULD BE
ABLE TO REACH THE UPPER 70S TO LOW 80S WELL INLAND WITH LOW TO MID
70S ALONG THE IMMEDIATE COAST. THINK RECORD LOWS MAY BE THREATENED
AT LOCATIONS SUCH AS GREENVILLE AND PERHAPS KINSTON LATER
TODAY...DESPITE FAIRLY THICK MID AND HIGH LEVEL CLOUDINESS. LATEST
HIGH RESOLUTION WRF AND RAP MODELS KEEP PRECIPITATION TO THE WEST
AND NORTH OF THE CWA TODAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
AS OF 325 AM FRIDAY...COLD FRONT WILL APPROACH THE REGION FROM THE
WEST LATER TODAY. BEST LOW-LEVEL MOISTURE TRANSPORT DOES NOT
ARRIVE IN OUR NORTHERN COUNTIES UNTIL AFTER MIDNIGHT AND WILL
SLOWLY RAMP POPS UP WITH CHANCE THRU THE LATE EVENING TO LIKELY
OVER NORTHERN COUNTIES BY LATE TONIGHT. QPF TOTALS THROUGH TONIGHT
DO NOT LOOK TO BE PARTICULARLY HEAVY...GENERALLY AT ONE-TENTH OF
AN INCH OR LESS. TEMPERATURES WILL VERY FROM THE MID TO UPPER 50S
ALONG THE FRONT OVER THE NORTHERN COUNTIES...TO THE MILD LOW AND
MID 60S AHEAD OF THE FRONT OVER THE SOUTHERN TWO-THIRDS OF THE
COUNTY WARNING AREA.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
AS OF 330 AM FRI...MODELS CONTINUE IN GOOD AGREEMENT ON PUSHING A
SURFACE COLD FRONT THROUGH EASTERN NC SAT MORNING WITH TEMPS
WARMEST IN THE MORNING AND SLOWLY FALLING THROUGHOUT THE DAY DUE
TO CLOUDS AND PRECIP OVERSPREADING THE REGION FROM NW TO SE. THERE
WILL BE A LARGE GRADIENT BETWEEN HEIGHTS/THICKNESSES FROM THE
COASTAL PLAIN COUNTIES TO THE COAST...WITH TEMPS FALLING INTO THE
50S BEHIND THE FRONT. FRONTAL BOUNDARY WILL BE AN ANAFRONT WITH
CLOUD/PRECIP BEHIND THE FRONT. THE UPPER TROUGH WILL REMAIN
CENTERED OVER THE CENTRAL/WESTERN CONUS AS A STRONG RIDGE ALOFT
REMAINS CENTERED OVER FLORIDA...PLACING EASTERN NC IN SW FLOW
ALOFT THROUGH EARLY IN THE WEEK. A STRONG FRONTAL INVERSION WILL
BE PRESENT SAT THROUGH SUN AS 850MB WINDS REMAIN SW WITH NLY
SURFACE WINDS. THIS WILL PRODUCE WIDESPREAD RAIN AND LOW CLOUDS
THROUGH EARLY SUN MORNING. COOLER TEMPS EXPECTED ON SUNDAY DUE TO
CLOUDS/PRECIP WITH HIGHS IN THE 40S INLAND TO 50S ALONG THE COAST.
LATEST GUIDANCE CONTINUES TO INDICATE A COASTAL TROUGH DEVELOPING
SUN AFTERNOON...WHICH BECOMES A WEAK LOW THAT MOVES NNE ALONG THE NC
COAST SUN NIGHT. AS THE LOW MOVES NE OF THE AREA LATE SUN NIGHT/EARLY
MON MORNING...COLD AIR DAMMING SCENARIO WILL SHIFT NW OF THE REGION
AS SW RETURN FLOW TAKES OVER WITH EASTERN NC AGAIN IN THE WARM
SECTOR.
UPPER RIDGE WILL STRENGTHEN AGAIN MON WITH HIGH TEMPS EXPECTED
BACK INTO THE 70S UNDER PARTLY SUNNY SKIES. LOW LEVEL THICKNESSES
BUILD 1385-1390 METERS RANGE...BUT MIXED CLOUDS MAY INHIBIT FULL
INSOLATION SO HELD TEMPS IN THE LOW 70S INLAND TO UPPER 60S
OBX...ALTHOUGH GREATER BREAKS IN CLOUD COVER COULD MEAN TEMPS
REACHING A FEW DEGREES HIGHER THAN CURRENTLY FORECAST.
ANOTHER COLD FRONT WILL PASS THROUGH EASTERN NC EARLY TUES MORNING
BRINGING MORE UNSETTLED WEATHER WITH RAIN AGAIN MOSTLY POST-
FRONTAL AND CONTINUING INTO TUES EVENING BEFORE STRONG HIGH PRESSURE
OVER THE CENTRAL CONUS SHIFTS EAST OVER THE MID-ATLANTIC REGION.
WED/THURS WILL BE DRY AND MUCH COOLER WITH TEMPS STRUGGLING TO
BUILD INTO THE MID 40S DUE TO STRONG COLD AIR ADVECTION IN NLY FLOW.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 325 AM FRIDAY...GIVEN A S/SW WIND IN THE 6 TO 8 KNOT
RANGE...DO NOT EXPECT MUCH IN THE WAY OF DENSE FOG AT THE TAF
SITES. EXPECT VFR WITH INCREASING WSW WINDS THROUGH THE DAY FRIDAY.
WIND GUSTS 20-25 KT LIKELY FROM LATE MORNING THRU MID AFTERNOON
FRIDAY. GUIDANCE AGAIN INDICATES PATCHY DENSE FOG LATE FRIDAY
NIGHT...BUT WITH SOME LIGHT SW WINDS...AGAIN MAY BE LIMITED IN
SCOPE.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 335 AM FRI...A COLD FRONT WILL APPROACH FROM THE NW FRI
NIGHT...MOVING THROUGH THE TERMINALS SAT MORNING. MODEL SOUNDINGS
INDICATE A PROLONGED PERIOD OF MVFR/IFR CONDITIONS EXPECTED TO
DEVELOP LATE FRI NIGHT AND CONTINUE THROUGH MUCH OF SUNDAY...WITH
WIDESPREAD RAIN ALSO DEVELOPING THIS WEEKEND. N/NE WIND GUSTS
15-20KT EXPECTED BEHIND THE FRONT SAT AFTERNOON. A WEAK LOW OFF
THE COAST WILL PUSH NE THROUGH THE AREA SUN NIGHT WITH SW FLOW
TAKING OVER MON WITH PRECIP CHANCES DIMINISHING AND LOWER CIGS
LIFTING N OF THE REGION THOUGH FOG MAY BE A POSSIBILITY AT NIGHT.
ANOTHER COLD FRONT CROSS THE TERMINALS FROM NW TO SE TUES WITH
ANOTHER ROUND OF MVFR/IFR CONDITIONS POSSIBLE IN LOWERED
CEILINGS/VSBYS THROUGH TUES. HIGH PRESSURE BUILDS OVER THE REGION
TUES NIGHT WITH CONDITIONS IMPROVING TO VFR.
&&
.MARINE...
SHORT TERM /TODAY AND TONIGHT/...
AS OF 325 AM FRIDAY...THE TIGHTENING PRESSURE GRAD AHEAD OF AN
APPROACHING COLD FRONT WILL RESULT IN INCREASING S-SW WINDS TO
15-20 KTS BY LATER THIS AFTERNOON...INCREASING TO 20 TO 25 KT
LATER TONIGHT. AS A RESULT...HAVE ISSUED A SMALL CRAFT ADVISORY
FOR THE COASTAL WATERS BEGINNING AT 03Z SATURDAY. SEAS ARE
CURRENTLY IN THE 2 TO 3 FOOT RANGE...BUT PER LOCAL NWPS/SWAN MODEL
AND WAVEWATCH GUIDANCE...SEAS WILL BUILD TO AS HIGH AS 6 FEET BY
LATE THIS EVENING AND TONIGHT.
LONG TERM /SATURDAY THROUGH TUESDAY/...
AS OF 345 AM FRI...SCA CONDITIONS WILL PERSIST OVER THE WATERS
THROUGH THE WEEKEND AS SW WINDS INCREASE TO 20 KT OR HIGHER WITH
SEAS REACHING 6 FT FOR THE OUTER CENTRAL/SOUTHERN WATERS. FRONT
WILL PASS THROUGH THE WATERS BY MIDDAY SAT WITH NORTHERLY CAA
SURGE INCREASING WINDS TO 20 KNOTS WITH SEAS 5-7 FT THROUGH SUN
MORNING. MODELS IN AGREEMENT WITH A WEAK INVERTED/COASTAL TROUGH
OVER THE SOUTHERN/CENTRAL WATERS SUN AFTERNOON WHICH DEVELOPS INTO
A WEAK SURFACE LOW AND MOVES NNE ALONG THE NC COAST SUN NIGHT.
SURFACE WINDS WILL BECOME SW ONCE THE WEAK LOW LIFTS NORTH OF THE
WATERS LATE SUN NIGHT. WINDS AND SEAS BRIEFLY SUBSIDE BELOW SCA
CRITERIA MON MORNING WITH SW WINDS 10-15 KT AND SEAS 3-5 FT...THEN
INCREASE TO 15-20 KT AND SEAS 4-7 FT AS THE GRADIENT TIGHTENS
BETWEEN SURFACE RIDGE OFF THE SOUTHEASTERN COAST AND A COLD FRONT
APPROACHING FROM THE NW. SCA CONDITIONS EXPECTED MON AFTERNOON
LASTING THROUGH AT LEAST TUES. WAVEWATCH III AND LOCAL SWAN/NWPS
IN GOOD AGREEMENT THROUGH THE LONG TERM.
&&
.CLIMATE...
RECORD HIGH (79) WAS SET IN NEW BERN ON THURSDAY AND MORE RECORD
WARMTH LIKELY ON FRIDAY.
BELOW IS A SUMMARY OF THE
CLIMATOLOGICAL RECORD HIGH TEMPERATURES FOR FRIDAY...DECEMBER 6TH:
RECORD HIGH FOR DEC 6:
NEW BERN 81 (1998)
GREENVILLE 80 (1998)
KINSTON 81 (1982)
NEWPORT 77 (1998)
BAYBORO 82 (1998)
MOREHEAD CITY 74 (2011)
WILLIAMSTON 76 (1998)
CAPE HATTERAS 77 (1982)
OCRACOKE 73 (1975)
MANTEO 78 (1998)
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 7 PM EST
SUNDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 1 PM EST
SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...DAG
AVIATION...CTC/DAG
MARINE...CTC/DAG
CLIMATE...CTC
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
409 PM EST FRI DEC 6 2013
.SYNOPSIS...
A SERIES OF LOW PRESSURE WAVES WILL TRACK NORTHEAST FROM THE
TENNESSEE VALLEY ACROSS THE MID-ATLANTIC STATES TONIGHT INTO
EARLY SATURDAY MORNING...BRINGING MIXED AND FROZEN PRECIPITATION
TO THE AREA. HIGH PRESSURE WILL PROVIDE A BRIEF RESPITE IN THE
RECENTLY ACTIVE EARLY SEASON WINTER WEATHER PATTERN ON SATURDAY
INTO SATURDAY NIGHT. CONFIDENCE CONTINUES TO INCREASE FOR A PERIOD
OF FROZEN AND FREEZING PRECIPITATION SUNDAY INTO EARLY MONDAY THAT
SHOULD EVENTUALLY CHANGE TO RAIN. AN ARCTIC FRONTAL PASSAGE EARLY
NEXT WEEK WILL DROP TEMPERATURES WELL BELOW NORMAL THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
RADAR AND SATELLITE SHOW THE PRECIPITATION SHIELD MOVING TOWARD
OUR REGION. UPDATED HIGH RESOLUTION MODELS SHOW THE TREND FOR FAST
TRANSITION RAIN TO SNOW AND FAST PERIOD OF SNOW WITH A TENDENCY TO
HAVE HIGHER QPF AND SNOW AMOUNTS FARTHER SOUTH. SNOW COULD BE
HEAVIER THIS EVENING AND INTO EARLY TONIGHT FARTHER SOUTH THAN
EARLIER FORECASTS.
THERE SHOULD BE A PERIOD OF MODERATE TO HEAVY SNOW THIS EVENING
AND TO ABOUT MIDNIGHT IN CENTRAL AND WESTERN PA. SIGNIFICANT SNOW
IS LIKELY BEFORE 9 PM.
IN CENTRAL AREAS THE RAIN WILL RAPIDLY MIX WITH ICE PELLETS AND
FREEZING RAIN THEN TURN TO SNOW. MOST MODELS SHOW THE 0C CONTOUR
RAIN/SNOW LINE PROXY THROUGH STATE COLLEGE ABOUT 5 PM. THIS
FEATURE STALL BETWEEN STATE COLLEGE AND HARRISBURG UNTIL ABOUT
MIDNIGHT.
MOST OF CENTRAL AND NORTHERN PENNSYLVANIA SHOULD SEE SNOW BY 7 PM
WITH SOME MIX OF ICE PELLETS AND FREEZING RAIN FARTHER SOUTH
BEFORE IT TRANSITIONS TO ALL RAIN IN THE LOWER SUSQUEHANNA VALLEY.
SOUTHEASTERN AREAS WILL REMAIN RAIN THIS EVENING.KEY POINT IN
CENTRAL AND NORTH-CENTRAL PA IS RAPID RAIN TO SNOW TRANSITION THIS
EVENING...
&&
.SHORT TERM /9 PM THIS EVENING THROUGH SATURDAY NIGHT/...
KEY ISSUE IS PRECIPITATION SHOULD BE OVER WELL BEFORE SUNRISE...
BETWEEN ABOUT 9 PM AND 2 AM THERE WILL BE SOME MODERATE TO HEAVY
SNOW OVER MOST OF CENTRAL AND NORTHERN PENNSYLVANIA. THE SNOW
SHOULD LET UP A FEW HOURS AFTER MIDNIGHT. SREF AND GEFS HAVE
HEAVIER SNOW BAND NORTH OF THE 4KM RAP AND 4KM NAM. WARNINGS MAY
HAVE TO SLIDE SOUTH SHOULD UPDATED SREF/GEFS INDICATE A SIMILAR
TREND.
WE WENT WITH THE HIGHER PROBABILITY FORECAST.
RAIN AND SNOW WITH FREEZING RAIN WILL SAG SOUTHWARD. EXTREME
SOUTHEASTERN AREAS LIKE HARRISBURG AND YORK SHOULD REMAIN ALL RAIN
AND MAY END WITH A BRIEF PERIOD OF FZDZ SATURDAY MORNING.
SATURDAY WILL BE COLD BUT SHOULD BE MOSTLY PRECIPITATION FREE.
LEFT SOME POST FRONTAL NW FLOW SNOW SHOWERS IN WESTERN AND
NORTHWESTERN MOUNTAINS SATURDAY.
&&
.LONG TERM /SUNDAY THROUGH THURSDAY/...
AFTER A BRIEF RESPITE FROM THE ACTIVE EARLY-SEASON WINTER WEATHER
PATTERN...THE COMBINATION OF LOW-LEVEL COLD AIR ASSOCIATED WITH A
RETREATING ARCTIC SFC HIGH...A STRONG UPPER RIDGE OFF THE
SOUTHEAST COAST...AND A PERSISTENT MOIST SOUTHWESTERLY UPPER FLOW
WITH EMBEDDED WEAK SYSTEMS OPERATING ON AN INTENSE/TIGHT FRONTAL-
BAROCLINIC ZONE /RATHER THAN ONE CONCENTRATED IMPULSE/ WILL BRING
ANOTHER ROUND OF MIXED/WINTRY PRECIPITATION TO THE REGION SUNDAY-
MONDAY. THE FRONTAL ZONE AND AND STRONG UPPER JET WILL SHIFT OFF
THE COAST INTO THE MIDDLE OF THE WEEK...ALLOWING A VERY COLD
AIRMASS TO SPREAD INTO THE REGION FOR LATE IN THE PERIOD.
ALL SIGNS CONTINUE TO POINT TOWARD A CLASSIC OVERRUNNING MIXED
WINTRY PRECIP EVENT FOR SUNDAY-MONDAY...ALTHOUGH THERE ARE SOME
MODEL DIFFS WITH REGARDS TO THE TIMING AND NRN EXTENT OF THE
PRECIP SHIELD.
A 150 KT UPPER JET WILL SHIFT NORTHWARD AS WEAK IMPULSES EJECT
NORTHEASTWARD OUT OF THE DEEP WESTERN TROUGH...WITH PRECIPITATION
EXPANDING NORTHWARD ALONG AN INVERTED SFC TROUGH AXIS ACROSS THE
SOUTHEAST/TENNESSEE VALLEY INTO THE MIDDLE ATLANTIC STATES.
A SURGE OF INTENSE 850-700MB WARM AIR/THETA E/MOISTURE ADVECTION
WILL SPREAD QUICKLY NEWD BEHIND THE FAST SWLY FLOW ALOFT AND
OVERRUN A SHALLOW LAYER OF LLVL SUB-FREEZING AIR DRAINING SWD
ALONG THE ERN SLOPES OF THE APPLCHNS.
THE SYNOPTIC PATTERN LOOKS VERY CONDUCIVE FOR A PERIOD OF
FREEZING-TO-FROZEN PCPN /SN-PL-FZRA/ AS MSTR AND STG WAA ALOFT
FLOWS OVER THE TOP OF A SHALLOW SUB-FZG AIRMASS THAT SHOULD REMAIN
ENTRENCHED ALONG/E OF THE ALLEGHENIES VIA LLVL COLD AIR
DAMMING/SFC PRES CHANNELING...ENHANCED BY NELY AGEO FLOW AND WET
BULB EFFECTS. SFC-850MB TEMPS ARE FCST TO WARM ENOUGH TO CHANGE
FREEZING PTYPES TO PLAIN RAIN IN MOST AREAS AROUND MON AFTN BEFORE
THE ARCTIC COLD FRONT CROSSES THE REGION MON NGT. THE 06/12Z GEFS
MEAN SHOWS A HIGH PROBABILITY OF A FEW INCHES OF SNOW/SLEET ON THE
LEADING EDGE OF THE PRECIP SHIELD FOLLOWED BY POTENTIAL
SIGNIFICANT ICE ACCUMS ESPECIALLY FROM THE LAURELS/SCNTRL MTNS
INTO THE INTERIOR N-CNTRL PART OF THE CWA. WILL CONTINUE TO
HIGHLIGHT THIS SYSTEM IN THE HWO BUT CONFIDENCE IS INCREASING IN
AT LEAST AN ADVISORY TYPE EVENT...IF NOT WARNING GIVEN POTENTIAL
FOR ICE ACCUM >0.25 INCH.
&&
.AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
DETERIORATING FLYING CONDS ARE EXPECTED ACROSS CENTRAL PA THIS
AFTN/EVE...AS ANOTHER ROUND OF PRECIPITATION PUSHES BACK INTO THE
AREA. NRN AND WRN TAF SITES WILL LIKELY SEE A WINTRY MIX CHANGING TO
SNOW THIS EVENING...WITH RAIN CONTINUING FARTHER TO THE SOUTHEAST
/MDT AND LNS/.
THE PRECIP SHOULD GRADUALLY TAPER OFF OVERNIGHT...WITH EVEN MDT
AND LNS POSSIBLY SEEING A BRIEF CHANGEOVER TO SNOW BEFORE THE
PRECIP ENDS.
IMPROVING CONDS EXPECTED FOR SATURDAY...AS THE SYSTEM PULLS EAST
OF THE REGION. NORTHWEST FLOW DEVELOPS...AND WE SHOULD SEE A
RETURN TO VFR CONDS. UPSLOPING NW FLOW COULD DELAY THE IMPROVEMENT
FOR THE WRN TAF SITES /JST AND BFD/...BUT EVEN THEY SHOULD IMPROVE
AS THE DAY PROGRESSES.
THINGS REMAIN QUIET SAT NIGHT INTO EARLY SUNDAY...BEFORE THE NEXT
SYSTEM BRINGS LOWERING CIGS AND SNOW DEVELOPING SUNDAY AFTN. THE
SNOW IS EXPECTED TO CHANGE OVER TO A WINTRY MIX OR RAIN SUNDAY
NIGHT...BEFORE GRADUALLY TAPERING OFF MONDAY.
OUTLOOK...
SAT...BECOMING VFR CENTRAL/EASTERN AREAS...WITH LOWER CIGS
POSSIBLY LINGERING ACROSS THE NORTH AND WEST.
SUN...VFR WILL GIVE WAY TO MVFR/IFR AS THE NEXT ROUND OF WINTRY
PRECIP ARRIVES.
MON...WIDESPREAD MVFR/IFR ASSOCIATED WITH A PASSING COLD FRONT.
TUE-WED...WEST TO NORTHWEST FLOW DEVELOPING. COLD WITH SCT -SHSN
NORTH AND WEST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 5 AM EST SATURDAY FOR PAZ019-
024>028-033>035-042-045-046-049>053.
WINTER STORM WARNING UNTIL 5 AM EST SATURDAY FOR PAZ004>006-
010>012-017-018-037-041.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...GRUMM/STEINBUGL
SHORT TERM...GRUMM/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...EVANEGO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
119 PM EST FRI DEC 6 2013
.SYNOPSIS...
A SERIES OF LOW PRESSURE WAVES WILL TRACK NORTHEAST FROM THE
TENNESSEE VALLEY ACROSS THE MID-ATLANTIC STATES TODAY THROUGH
SATURDAY...BRINGING A CHANGEOVER TO MIXED AND FROZEN PRECIPITATION
TO THE AREA. HIGH PRESSURE WILL PROVIDE A BRIEF RESPITE IN THE
RECENTLY ACTIVE EARLY SEASON WINTER WEATHER PATTERN ON SATURDAY.
CONFIDENCE IS STEADILY INCREASING FOR A PERIOD OF FROZEN AND
FREEZING PRECIPITATION SUNDAY INTO EARLY MONDAY THAT SHOULD
EVENTUALLY CHANGE TO RAIN. AN ARCTIC FRONTAL PASSAGE EARLY NEXT
WEEK WILL DROP TEMPERATURES WELL BELOW NORMAL THROUGH NEXT
WEDNESDAY.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
RADAR AND SATELLITE SHOW THE PRECIPITATION SHIELD MOVING TOWARD
OUR REGION. UPDATED HIGH RESOLUTION MODELS SHOW THE TREND FOR FAST
TRANSITION RAIN TO SNOW AND FAST PERIOD OF SNOW WITH A TENDENCY TO
HAVE HIGHER QPF AND SNOW AMOUNTS FARTHER SOUTH. SNOW COULD BE
HEAVIER THIS EVENING AND INTO EARLY TONIGHT FARTHER SOUTH THAN
EARLIER FORECASTS.
THERE SHOULD BE A PERIOD OF MODERATE TO HEAVY SNOW THIS EVENING
AND TO ABOUT MIDNIGHT IN CENTRAL AND WESTERN PA. SIGNIFICANT SNOW
IS LIKELY BEFORE 9 PM.
IN CENTRAL AREAS THE RAIN WILL RAPIDLY MIX WITH ICE PELLETS AND
FREEZING RAIN THEN TURN TO SNOW. MOST MODELS SHOW THE 0C CONTOUR
RAIN/SNOW LINE PROXY THROUGH STATE COLLEGE ABOUT 5 PM. THIS
FEATURE STALL BETWEEN STATE COLLEGE AND HARRISBURG UNTIL ABOUT
MIDNIGHT.
MOST OF CENTRAL AND NORTHERN PENNSYLVANIA SHOULD SEE SNOW BY 7 PM
WITH SOME MIX OF ICE PELLETS AND FREEZING RAIN FARTHER SOUTH
BEFORE IT TRANSITIONS TO ALL RAIN IN THE LOWER SUSQUEHANNA VALLEY.
SOUTHEASTERN AREAS WILL REMAIN RAIN THIS EVENING.
KEY POINT IN CENTRAL AND NORTH-CENTRAL PA IS RAPID RAIN TO SNOW
TRANSITION THIS EVENING...
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM SATURDAY/...
KEY ISSUE IS PRECIPITATION SHOULD BE OVER WELL BEFORE SUNRISE...
BETWEEN ABOUT 9 PM AND 2 AM THERE WILL BE SOME MODERATE TO HEAVY
SNOW OVER MOST OF CENTRAL AND NORTHERN PENNSYLVANIA. THE SNOW
SHOULD LET UP A FEW HOURS AFTER MIDNIGHT. SREF AND GEFS HAVE
HEAVIER SNOW BAND NORTH OF THE 4KM RAP AND 4KM NAM. WARNINGS MAY
HAVE TO SLIDE SOUTH SHOULD UPDATED SREF/GEFS INDICATE A SIMILAR
TREND.
WE WENT WITH THE HIGHER PROBABILITY FORECAST.
RAIN AND SNOW WITH FREEZING RAIN WILL SAG SOUTHWARD. EXTREME
SOUTHEASTERN AREAS LIKE HARRISBURG AND YORK SHOULD REMAIN ALL RAIN
AND MAY END WITH A BRIEF PERIOD OF FZDZ SATURDAY MORNING.
SATURDAY WILL BE COLD BUT SHOULD BE MOSTLY PRECIPITATION FREE.
LEFT SOME POST FRONTAL NW FLOW SNOW SHOWERS IN WESTERN AND
NORTHWESTERN MOUNTAINS SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH FRIDAY/...
THERE IS THE POTENTIAL FOR SIGNIFICANT FREEZING RAIN LATE
SUNDAY AND EARLY MONDAY IN THE SOUTHWEST MOUNTAINS....
PREVIOUS DISCUSSION...1040+ MB MODIFIED ARCTIC SFC HIGH PRESSURE
OVER THE UPPER MIDWEST SATURDAY WILL MIGRATE EASTWARD INTO THE
NORTHERN MID- ATLANTIC STATES BY SUNDAY MORNING...SETTING THE
STAGE FOR WHAT APPEARS TO BE A CLASSIC OVERRUNNING MIXED PRECIP
EVENT FOR LATER SUNDAY INTO MONDAY.
05/12Z DETERMINISTIC MODEL AND ENSEMBLE GUIDANCE SHOWS LOW PRES
INITIALLY DEVELOPING ALONG AN INVERTED SFC TROUGH AXIS EXTENDING
FROM THE LWR MS/TN VLY NEWD UP THE WEST-SIDE OF THE APPALACHIANS.
THE MAIN LOW SHOULD LIFT NWD THRU THE OH VLY/GRT LKS INTO SERN
CANADA ON DAYS 5-6. MEANWHILE A SECONDARY/WEAKER AREA OF LOW PRES
SHOULD FORM NEAR THE VA/NC COAST AND TRACK NNEWD JUST OFFSHORE SRN
NEW ENGLAND.
DOWNSTREAM FROM A VIGOROUS MID/UPPER LEVEL TROUGH DIGGING THROUGH
THE FOUR CORNERS/SRN ROCKIES...A SURGE OF INTENSE 850-700MB WARM
AIR/THETA E/MOISTURE ADVECTION WILL SPREAD QUICKLY NEWD BEHIND A
BROAD SWLY FLOW ALOFT AND OVERRUN A RETREATING COLD SECTOR
ASSOCIATED WITH THE RETREATING ARCTIC HIGH. THE SYNOPTIC PATTERN
LOOKS VERY CONDUCIVE FOR A PERIOD OF FREEZING-TO-FROZEN PCPN AS
MSTR AND STG WAA ALOFT FLOWS OVER THE TOP OF A SHALLOW SUB-FZG
AIRMASS THAT SHOULD REMAIN ENTRENCHED ALONG/E OF THE ALLEGHENIES
VIA LLVL COLD AIR DAMMING/SFC PRES CHANNELING...ENHANCED BY NELY
AGEO FLOW AND WET BULB EFFECTS. SFC-850MB TEMPS ARE FCST TO WARM
ENOUGH TO CHANGE FREEZING PTYPES TO PLAIN RAIN IN MOST AREAS
AROUND MON AFTN BEFORE THE ARCTIC COLD FRONT CROSSES THE REGION
MON NGT. THE 12Z GEFS MEAN SHOWS A HIGH PROBABILITY OF A FEW
INCHES OF SNOW/SLEET ON THE LEADING EDGE OF THE PRECIP SHIELD
FOLLOWED BY POTENTIAL SIGNIFICANT ICE ACCUMS ESPECIALLY FROM THE
LAURELS/SCNTRL MTNS INTO THE INTERIOR N-CNTRL PART OF THE CWA.
WILL CONTINUE TO HIGHLIGHT THIS SYSTEM IN THE HWO BUT CONFIDENCE
IS INCREASING IN AT LEAST AN ADVISORY TYPE EVENT...IF NOT WARNING
ASSUMING MOD-HVY ICING VIA FZRA.
IN THE WAKE OF THIS SYSTEM...A VERY COLD PATTERN SHOULD GRIP THE
REGION THRU THE MIDDLE OF NEXT WEEK WITH TEMPERATURES WELL BELOW
NORMAL. SOME LAKE EFFECT SNOW SHOWERS ARE POSSIBLE IN THE COLD
CYC FLOW ALOFT ALTHOUGH THE LLVL WINDS MAY HAVE TOO MUCH OF A SW
COMPNT WHICH WOULD ORIENT BANDS MORE ALONG THE LAKE ERIE SHORE
INTO SW NY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
DETERIORATING FLYING CONDS ARE EXPECTED ACROSS CENTRAL PA THIS
AFTN/EVE...AS ANOTHER ROUND OF PRECIPITATION PUSHES BACK INTO THE
AREA. NRN AND WRN TAF SITES WILL LIKELY SEE A WINTRY MIX CHANGING TO
SNOW THIS EVENING...WITH RAIN CONTINUING FARTHER TO THE SOUTHEAST
/MDT AND LNS/.
THE PRECIP SHOULD GRADUALLY TAPER OFF OVERNIGHT...WITH EVEN MDT
AND LNS POSSIBLY SEEING A BRIEF CHANGEOVER TO SNOW BEFORE THE
PRECIP ENDS.
IMPROVING CONDS EXPECTED FOR SATURDAY...AS THE SYSTEM PULLS EAST
OF THE REGION. NORTHWEST FLOW DEVELOPS...AND WE SHOULD SEE A
RETURN TO VFR CONDS. UPSLOPING NW FLOW COULD DELAY THE IMPROVEMENT
FOR THE WRN TAF SITES /JST AND BFD/...BUT EVEN THEY SHOULD IMPROVE
AS THE DAY PROGRESSES.
THINGS REMAIN QUIET SAT NIGHT INTO EARLY SUNDAY...BEFORE THE NEXT
SYSTEM BRINGS LOWERING CIGS AND SNOW DEVELOPING SUNDAY AFTN. THE
SNOW IS EXPCETED TO CHANGE OVER TO A WINTRY MIX OR RAIN SUNDAY
NIGHT...BEFORE GRADUALLY TAPERING OFF MONDAY.
OUTLOOK...
SAT...BECOMING VFR CENTRAL/EASTERN AREAS...WITH LOWER CIGS
POSSIBLY LINGERING ACROSS THE NORTH AND WEST.
SUN...VFR WILL GIVE WAY TO MVFR/IFR AS THE NEXT ROUND OF WINTRY
PRECIP ARRIVES.
MON...WIDESPREAD MVFR/IFR ASSOCIATED WITH A PASSING COLD FRONT.
TUE-WED...WEST TO NORTHWEST FLOW DEVELOPING. COLD WITH SCT -SNSH
NORTH AND WEST.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ019-024>028-033>035-042-045-046-049>053.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ004>006-010>012-017-018-037-041.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...GRUMM/STEINBUGL
SHORT TERM...GRUMM/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...EVANEGO
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1239 PM EST FRI DEC 6 2013
.SYNOPSIS...
A SERIES OF LOW PRESSURE WAVES WILL TRACK NORTHEAST FROM THE
TENNESSEE VALLEY ACROSS THE MID-ATLANTIC STATES TODAY THROUGH
SATURDAY...BRINGING A CHANGEOVER TO MIXED AND FROZEN PRECIPITATION
TO THE AREA. HIGH PRESSURE WILL PROVIDE A BRIEF RESPITE IN THE
RECENTLY ACTIVE EARLY SEASON WINTER WEATHER PATTERN ON SATURDAY.
CONFIDENCE IS STEADILY INCREASING FOR A PERIOD OF FROZEN AND
FREEZING PRECIPITATION SUNDAY INTO EARLY MONDAY THAT SHOULD
EVENTUALLY CHANGE TO RAIN. AN ARCTIC FRONTAL PASSAGE EARLY NEXT
WEEK WILL DROP TEMPERATURES WELL BELOW NORMAL THROUGH NEXT
WEDNESDAY.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
RADAR AND SATELLITE SHOW THE PRECIPITATION SHIELD MOVING TOWARD
OUR REGION. UPDATED HIGH RESOLUTION MODELS SHOW THE TREND FOR FAST
TRANSITION RAIN TO SNOW AND FAST PERIOD OF SNOW WITH A TENDENCY TO
HAVE HIGHER QPF AND SNOW AMOUNTS FARTHER SOUTH. SNOW COULD BE
HEAVIER THIS EVENING AND INTO EARLY TONIGHT FARTHER SOUTH THAN
EARLIER FORECASTS.
THERE SHOULD BE A PERIOD OF MODERATE TO HEAVY SNOW THIS EVENING
AND TO ABOUT MIDNIGHT IN CENTRAL AND WESTERN PA. SIGNIFICANT SNOW
IS LIKELY BEFORE 9 PM.
IN CENTRAL AREAS THE RAIN WILL RAPIDLY MIX WITH ICE PELLETS AND
FREEZING RAIN THEN TURN TO SNOW. MOST MODELS SHOW THE 0C CONTOUR
RAIN/SNOW LINE PROXY THROUGH STATE COLLEGE ABOUT 5 PM. THIS
FEATURE STALL BETWEEN STATE COLLEGE AND HARRISBURG UNTIL ABOUT
MIDNIGHT.
MOST OF CENTRAL AND NORTHERN PENNSYLVANIA SHOULD SEE SNOW BY 7 PM
WITH SOME MIX OF ICE PELLETS AND FREEZING RAIN FARTHER SOUTH
BEFORE IT TRANSITIONS TO ALL RAIN IN THE LOWER SUSQUEHANNA VALLEY.
SOUTHEASTERN AREAS WILL REMAIN RAIN THIS EVENING.
KEY POINT IN CENTRAL AND NORTH-CENTRAL PA IS RAPID RAIN TO SNOW
TRANSITION THIS EVENING...
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM SATURDAY/...
...KEY ISSUE IS PRECIPITATION SHOULD BE OVER WELL BEFORE SUNRISE...
BETWEEN ABOUT 9 PM AND 2 AM THERE WILL BE SOME MODERATE TO HEAVY
SNOW OVER MOST OF CENTRAL AND NORTHERN PENNSYLVANIA. THE SNOW
SHOULD LET UP A FEW HOURS AFTER MIDNIGHT. SREF AND GEFS HAVE
HEAVIER SNOW BAND NORTH OF THE 4KM RAP AND 4KM NAM. WARNINGS MAY
HAVE TO SLIDE SOUTH SHOULD UPDATED SREF/GEFS INDICATE A SIMILAR
TREND.
WE WENT WITH THE HIGHER PROBABILITY FORECAST.
RAIN AND SNOW WITH FREEZING RAIN WILL SAG SOUTHWARD. EXTREME
SOUTHEASTERN AREAS LIKE HARRISBURG AND YORK SHOULD REMAIN ALL RAIN
AND MAY END WITH A BRIEF PERIOD OF FZDZ SATURDAY MORNING.
SATURDAY WILL BE COLD BUT SHOULD BE MOSTLY PRECIPITATION FREE.
LEFT SOME POST FRONTAL NW FLOW SNOW SHOWERS IN WESTERN AND
NORTHWESTERN MOUNTAINS SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THERE IS THE POTENTIAL FOR SIGNIFICANT FREEZING RAIN LATE
SUNDAY AND EARLY MONDAY IN THE SOUTHWEST MOUNTAINS....
PREVIOUS DISCUSSION...1040+ MB MODIFIED ARCTIC SFC HIGH PRESSURE
OVER THE UPPER MIDWEST SATURDAY WILL MIGRATE EASTWARD INTO THE
NORTHERN MID- ATLANTIC STATES BY SUNDAY MORNING...SETTING THE
STAGE FOR WHAT APPEARS TO BE A CLASSIC OVERRUNNING MIXED PRECIP
EVENT FOR LATER SUNDAY INTO MONDAY.
05/12Z DETERMINISTIC MODEL AND ENSEMBLE GUIDANCE SHOWS LOW PRES
INITIALLY DEVELOPING ALONG AN INVERTED SFC TROUGH AXIS EXTENDING
FROM THE LWR MS/TN VLY NEWD UP THE WEST-SIDE OF THE APPALACHIANS.
THE MAIN LOW SHOULD LIFT NWD THRU THE OH VLY/GRT LKS INTO SERN
CANADA ON DAYS 5-6. MEANWHILE A SECONDARY/WEAKER AREA OF LOW PRES
SHOULD FORM NEAR THE VA/NC COAST AND TRACK NNEWD JUST OFFSHORE SRN
NEW ENGLAND.
DOWNSTREAM FROM A VIGOROUS MID/UPPER LEVEL TROUGH DIGGING THROUGH
THE FOUR CORNERS/SRN ROCKIES...A SURGE OF INTENSE 850-700MB WARM
AIR/THETA E/MOISTURE ADVECTION WILL SPREAD QUICKLY NEWD BEHIND A
BROAD SWLY FLOW ALOFT AND OVERRUN A RETREATING COLD SECTOR
ASSOCIATED WITH THE RETREATING ARCTIC HIGH. THE SYNOPTIC PATTERN
LOOKS VERY CONDUCIVE FOR A PERIOD OF FREEZING-TO-FROZEN PCPN AS
MSTR AND STG WAA ALOFT FLOWS OVER THE TOP OF A SHALLOW SUB-FZG
AIRMASS THAT SHOULD REMAIN ENTRENCHED ALONG/E OF THE ALLEGHENIES
VIA LLVL COLD AIR DAMMING/SFC PRES CHANNELING...ENHANCED BY NELY
AGEO FLOW AND WET BULB EFFECTS. SFC-850MB TEMPS ARE FCST TO WARM
ENOUGH TO CHANGE FREEZING PTYPES TO PLAIN RAIN IN MOST AREAS
AROUND MON AFTN BEFORE THE ARCTIC COLD FRONT CROSSES THE REGION
MON NGT. THE 12Z GEFS MEAN SHOWS A HIGH PROBABILITY OF A FEW
INCHES OF SNOW/SLEET ON THE LEADING EDGE OF THE PRECIP SHIELD
FOLLOWED BY POTENTIAL SIGNIFICANT ICE ACCUMS ESPECIALLY FROM THE
LAURELS/SCNTRL MTNS INTO THE INTERIOR N-CNTRL PART OF THE CWA.
WILL CONTINUE TO HIGHLIGHT THIS SYSTEM IN THE HWO BUT CONFIDENCE
IS INCREASING IN AT LEAST AN ADVISORY TYPE EVENT...IF NOT WARNING
ASSUMING MOD-HVY ICING VIA FZRA.
IN THE WAKE OF THIS SYSTEM...A VERY COLD PATTERN SHOULD GRIP THE
REGION THRU THE MIDDLE OF NEXT WEEK WITH TEMPERATURES WELL BELOW
NORMAL. SOME LAKE EFFECT SNOW SHOWERS ARE POSSIBLE IN THE COLD
CYC FLOW ALOFT ALTHOUGH THE LLVL WINDS MAY HAVE TOO MUCH OF A SW
COMPNT WHICH WOULD ORIENT BANDS MORE ALONG THE LAKE ERIE SHORE
INTO SW NY.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
A SHALLOW FRONTAL BOUNDARY BROUGHT AN END TO MOST OF THE
PRECIPITATION ACROSS THE REGION THIS MORNING. MOST VFR AND MVFR
CONDITIONS FOR THE NEXT FEW HOURS.
SNOW WILL MOVE INTO NORTHWESTERN AREAS THIS AFTERNOON AND LOWER
CEILINGS AND HEIGHTS. RAIN AND SNOW WILL MOVE INTO CENTRAL AREAS
IN THE 19 TO 22Z TIME-FRAME LOWERING CEILINGS AND HEIGHTS IN THAT
REGION. RAIN WILL MOVE INTO SOUTHERN REGIONS.
SHOULD BE MOSTLY IFR WITH AREAS OF LIFR IN SNOW AND RAIN.
THERE WILL BE A RAPID CHANGE OVER TO ALL SNOW IN CENTRAL AREAS
FROM ABOUT KAOO-KUNV-KIPT THIS EVENING.
THE PRECIPITATION SHOULD END RAPIDLY AFTER MIDNIGHT WITH A RETURN
TO MOSTLY VFR ON SATURDAY WITH SOME AREAS OF SNOW SHOWERS IN THE
WESTERN MOUNTAINS.
OUTLOOK...
FRI...VFR/MVFR SOME RAIN SE. AFTERNOON-EVEN...IFR IN SNOW/WINTRY
MIX AND RAIN.
SAT...MVFR SNOW SHOWERS IN THE MOUNTAINS. VFR IN CENTRAL/EASTERN
AREAS.
SUN...VFR WILL GIVE WAY TO IFR AS A WINTER STORM RAPIDLY SWEEPS
INTO THE REGION SUNDAY INTO SUNDAY NIGHT.
MON...WIDESPREAD MVFR/IFR ASSOCIATED WITH A PASSING COLD FRONT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ019-024>028-033>035-042-045-046-049>053.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ004>006-010>012-017-018-037-041.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...GRUMM/STEINBUGL
SHORT TERM...GRUMM/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1115 AM EST FRI DEC 6 2013
.SYNOPSIS...
A SERIES OF LOW PRESSURE WAVES WILL TRACK NORTHEAST FROM THE
TENNESSEE VALLEY ACROSS THE MID-ATLANTIC STATES TODAY THROUGH
SATURDAY...BRINGING A CHANGEOVER TO MIXED AND FROZEN PRECIPITATION
TO THE AREA. HIGH PRESSURE WILL PROVIDE A BRIEF RESPITE IN THE
RECENTLY ACTIVE EARLY SEASON WINTER WEATHER PATTERN ON SATURDAY.
CONFIDENCE IS STEADILY INCREASING FOR A PERIOD OF FROZEN AND
FREEZING PRECIPITATION SUNDAY INTO EARLY MONDAY THAT SHOULD
EVENTUALLY CHANGE TO RAIN. AN ARCTIC FRONTAL PASSAGE EARLY NEXT
WEEK WILL DROP TEMPERATURES WELL BELOW NORMAL THROUGH NEXT
WEDNESDAY.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
AN ENHANCED AREA OF ENHANCED CLOUDS AND LIGHT RAIN WILL MOVE
ACROSS SOUTHEASTERN PA. A SHALLOW FRONTAL BOUNDARY OVER THE REGION
IS SLOWLY PUSHING COLD AIR IN FROM NORTHWEST TO SOUTH EAST.
TEMPERATURES ARE BELOW FREEZING IN NW PA AND IN THE 40S IN THE
SOUTHEAST. THE 850 MB ZERO ISOTHERM IS IN NW PA. FRONTAL ZONE AT
850 AND A WAVE TO THE WEST WILL PRODUCE SNOW...HEAVY SNOW...SOME
ICE...AND RAIN OVER THE STATE IN THE NEXT 18 HOURS.
THE MAIN PLAYER IS REALLY A LARGE ANTICYCLONE TO THE WEST AND COLD
AIR. THE "STORM" IS REALLY JUST A STRONG FRONTAL ZONE.
THE SREF AND GEFS SUGGEST SNOW WILL MOVE INTO NORTHWESTERN PA THIS
AFTERNOON AND LATER THIS AFTERNOON RAIN WILL MOVE INTO CENTRAL PA.
A SNOW-BAND IS EVOLVING OVER OHIO. THE RAP AND 4KM NAM SUGGEST THE
HEAVIEST SNOW COULD BE A BIT MORE SOUTH THAN THE 16KM SREF AND
55KM GEFS.
THERE SHOULD BE A PERIOD OF MODERATE TO HEAVY SNOW THIS EVENING
AND TO ABOUT MIDNIGHT IN NORTHWESTERN PA. SIGNIFICANT SNOW IS
LIKELY BEFORE 9 PM.
IN CENTRAL AREAS THE RAIN WILL RAPIDLY MIX WITH ICE PELLETS AND
FREEZING RAIN THEN TURN TO SNOW. MOST MODELS SHOW THE 0C CONTOUR
RAIN/SNOW LINE PROXY THROUGH STATE COLLEGE ABOUT 5 PM. THIS
FEATURE STALL BETWEEN STATE COLLEGE AND HARRISBURG UNTIL ABOUT
MIDNIGHT.
MOST OF CENTRAL AND NORTHERN PENNSYLVANIA SHOULD SEE SNOW BY 7 PM
WITH SOME MIX OF ICE PELLETS AND FREEZING RAIN FARTHER SOUTH
BEFORE IT TRANSITIONS TO ALL RAIN IN THE LOWER SUSQUEHANNA VALLEY.
SOUTHEASTERN AREAS WILL REMAIN RAIN THIS EVENING.
KEY POINT IN CENTRAL AND NORTH-CENTRAL PA IS RAPID RAIN TO SNOW
TRANSITION THIS EVENING...
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM SATURDAY/...
BETWEEN ABOUT 9 PM AND 2 AM THERE WILL BE SOME MODERATE TO HEAVY
SNOW OVER MOST OF CENTRAL AND NORTHERN PENNSYLVANIA. THE SNOW
SHOULD LET UP A FEW HOURS AFTER MIDNIGHT. SREF AND GEFS HAVE
HEAVIER SNOW BAND NORTH OF THE 4KM RAP AND 4KM NAM. WARNINGS MAY
HAVE TO SLIDE SOUTH SHOULD UPDATED SREF/GEFS INDICATE A SIMILAR TREND.
WE WENT WITH THE HIGHER PROBABILITY FORECAST.
RAIN AND SNOW WITH FREEZING RAIN WILL SAG SOUTHWARD. EXTREME
SOUTHEASTERN AREAS LIKE HARRISBURG AND YORK SHOULD REMAIN ALL RAIN
AND MAY END WITH A BRIEF PERIOD OF FZDZ SATURDAY MORNING.
THE MODELS SUGGEST THE PRECIPITATION IS WELL TO OUR EAST A FEW
HOURS EITHER SIDE OF ABOUT 7 AM. SATURDAY WILL BE COLD BUT SHOULD
BE MOSTLY PRECIPITATION FREE.
LEFT SOME POST FRONTAL NW FLOW SNOW SHOWERS IN WESTERN AND
NORTHWESTERN MOUNTAINS SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THERE IS THE POTENTIAL FOR SIGNIFICANT FREEZING RAIN LATE
SUNDAY AND EARLY MONDAY IN THE SOUTHWEST MOUNTAINS....
PREVIOUS DISCUSSION...1040+ MB MODIFIED ARCTIC SFC HIGH PRESSURE
OVER THE UPPER MIDWEST SATURDAY WILL MIGRATE EASTWARD INTO THE
NORTHERN MID- ATLANTIC STATES BY SUNDAY MORNING...SETTING THE
STAGE FOR WHAT APPEARS TO BE A CLASSIC OVERRUNNING MIXED PRECIP
EVENT FOR LATER SUNDAY INTO MONDAY.
05/12Z DETERMINISTIC MODEL AND ENSEMBLE GUIDANCE SHOWS LOW PRES
INITIALLY DEVELOPING ALONG AN INVERTED SFC TROUGH AXIS EXTENDING
FROM THE LWR MS/TN VLY NEWD UP THE WEST-SIDE OF THE APPALACHIANS.
THE MAIN LOW SHOULD LIFT NWD THRU THE OH VLY/GRT LKS INTO SERN
CANADA ON DAYS 5-6. MEANWHILE A SECONDARY/WEAKER AREA OF LOW PRES
SHOULD FORM NEAR THE VA/NC COAST AND TRACK NNEWD JUST OFFSHORE SRN
NEW ENGLAND.
DOWNSTREAM FROM A VIGOROUS MID/UPPER LEVEL TROUGH DIGGING THROUGH
THE FOUR CORNERS/SRN ROCKIES...A SURGE OF INTENSE 850-700MB WARM
AIR/THETA E/MOISTURE ADVECTION WILL SPREAD QUICKLY NEWD BEHIND A
BROAD SWLY FLOW ALOFT AND OVERRUN A RETREATING COLD SECTOR
ASSOCIATED WITH THE RETREATING ARCTIC HIGH. THE SYNOPTIC PATTERN
LOOKS VERY CONDUCIVE FOR A PERIOD OF FREEZING-TO-FROZEN PCPN AS
MSTR AND STG WAA ALOFT FLOWS OVER THE TOP OF A SHALLOW SUB-FZG
AIRMASS THAT SHOULD REMAIN ENTRENCHED ALONG/E OF THE ALLEGHENIES
VIA LLVL COLD AIR DAMMING/SFC PRES CHANNELING...ENHANCED BY NELY
AGEO FLOW AND WET BULB EFFECTS. SFC-850MB TEMPS ARE FCST TO WARM
ENOUGH TO CHANGE FREEZING PTYPES TO PLAIN RAIN IN MOST AREAS
AROUND MON AFTN BEFORE THE ARCTIC COLD FRONT CROSSES THE REGION
MON NGT. THE 12Z GEFS MEAN SHOWS A HIGH PROBABILITY OF A FEW
INCHES OF SNOW/SLEET ON THE LEADING EDGE OF THE PRECIP SHIELD
FOLLOWED BY POTENTIAL SIGNIFICANT ICE ACCUMS ESPECIALLY FROM THE
LAURELS/SCNTRL MTNS INTO THE INTERIOR N-CNTRL PART OF THE CWA.
WILL CONTINUE TO HIGHLIGHT THIS SYSTEM IN THE HWO BUT CONFIDENCE
IS INCREASING IN AT LEAST AN ADVISORY TYPE EVENT...IF NOT WARNING
ASSUMING MOD-HVY ICING VIA FZRA.
IN THE WAKE OF THIS SYSTEM...A VERY COLD PATTERN SHOULD GRIP THE
REGION THRU THE MIDDLE OF NEXT WEEK WITH TEMPERATURES WELL BELOW
NORMAL. SOME LAKE EFFECT SNOW SHOWERS ARE POSSIBLE IN THE COLD
CYC FLOW ALOFT ALTHOUGH THE LLVL WINDS MAY HAVE TOO MUCH OF A SW
COMPNT WHICH WOULD ORIENT BANDS MORE ALONG THE LAKE ERIE SHORE
INTO SW NY.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
A SHALLOW FRONTAL BOUNDARY BROUGHT AN END TO MOST OF THE
PRECIPITATION ACROSS THE REGION THIS MORNING. MOST VFR AND MVFR
CONDITIONS FOR THE NEXT FEW HOURS.
SNOW WILL MOVE INTO NORTHWESTERN AREAS THIS AFTERNOON AND LOWER
CEILINGS AND HEIGHTS. RAIN AND SNOW WILL MOVE INTO CENTRAL AREAS
IN THE 19 TO 22Z TIME-FRAME LOWERING CEILINGS AND HEIGHTS IN THAT
REGION. RAIN WILL MOVE INTO SOUTHERN REGIONS.
SHOULD BE MOSTLY IFR WITH AREAS OF LIFR IN SNOW AND RAIN.
THERE WILL BE A RAPID CHANGE OVER TO ALL SNOW IN CENTRAL AREAS
FROM ABOUT KAOO-KUNV-KIPT THIS EVENING.
THE PRECIPITATION SHOULD END RAPIDLY AFTER MIDNIGHT WITH A RETURN
TO MOSTLY VFR ON SATURDAY WITH SOME AREAS OF SNOW SHOWERS IN THE
WESTERN MOUNTAINS.
OUTLOOK...
FRI...VFR/MVFR SOME RAIN SE. AFTERNOON-EVEN...IFR IN SNOW/WINTRY
MIX AND RAIN.
SAT...MVFR SNOW SHOWERS IN THE MOUNTAINS. VFR IN CENTRAL/EASTERN
AREAS.
SUN...VFR WILL GIVE WAY TO IFR AS A WINTER STORM RAPIDLY SWEEPS
INTO THE REGION SUNDAY INTO SUNDAY NIGHT.
MON...WIDESPREAD MVFR/IFR ASSOCIATED WITH A PASSING COLD FRONT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ019-024>028-033>035-042-045-046-049>053.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ004>006-010>012-017-018-037-041.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...GRUMM/STEINBUGL
SHORT TERM...GRUMM/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...GRUMM
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1056 AM EST FRI DEC 6 2013
.SYNOPSIS...
A SERIES OF LOW PRESSURE WAVES WILL TRACK NORTHEAST FROM THE
TENNESSEE VALLEY ACROSS THE MID-ATLANTIC STATES TODAY THROUGH
SATURDAY...BRINGING A CHANGEOVER TO MIXED AND FROZEN PRECIPITATION
TO THE AREA. HIGH PRESSURE WILL PROVIDE A BRIEF RESPITE IN THE
RECENTLY ACTIVE EARLY SEASON WINTER WEATHER PATTERN ON SATURDAY.
CONFIDENCE IS STEADILY INCREASING FOR A PERIOD OF FROZEN AND
FREEZING PRECIPITATION SUNDAY INTO EARLY MONDAY THAT SHOULD
EVENTUALLY CHANGE TO RAIN. AN ARCTIC FRONTAL PASSAGE EARLY NEXT
WEEK WILL DROP TEMPERATURES WELL BELOW NORMAL THROUGH NEXT
WEDNESDAY.
&&
.NEAR TERM /UNTIL 9 PM THIS EVENING/...
AN ENHANCED AREA OF ENHANCED CLOUDS AND LIGHT RAIN WILL MOVE
ACROSS SOUTHEASTERN PA. A SHALLOW FRONTAL BOUNDARY OVER THE REGION
IS SLOWLY PUSHING COLD AIR IN FROM NORTHWEST TO SOUTH EAST.
TEMPERATURES ARE BELOW FREEZING IN NW PA AND IN THE 40S IN THE
SOUTHEAST. THE 850 MB ZERO ISOTHERM IS IN NW PA. FRONTAL ZONE AT
850 AND A WAVE TO THE WEST WILL PRODUCE SNOW...HEAVY SNOW...SOME
ICE...AND RAIN OVER THE STATE IN THE NEXT 18 HOURS.
THE MAIN PLAYER IS REALLY A LARGE ANTICYCLONE TO THE WEST AND COLD
AIR. THE "STORM" IS REALLY JUST A STRONG FRONTAL ZONE.
THE SREF AND GEFS SUGGEST SNOW WILL MOVE INTO NORTHWESTERN PA THIS
AFTERNOON AND LATER THIS AFTERNOON RAIN WILL MOVE INTO CENTRAL PA.
A SNOW-BAND IS EVOLVING OVER OHIO. THE RAP AND 4KM NAM SUGGEST THE
HEAVIEST SNOW COULD BE A BIT MORE SOUTH THAN THE 16KM SREF AND
55KM GEFS.
THERE SHOULD BE A PERIOD OF MODERATE TO HEAVY SNOW THIS EVENING
AND TO ABOUT MIDNIGHT IN NORTHWESTERN PA. SIGNIFICANT SNOW IS
LIKELY BEFORE 9 PM.
IN CENTRAL AREAS THE RAIN WILL RAPIDLY MIX WITH ICE PELLETS AND
FREEZING RAIN THEN TURN TO SNOW. MOST MODELS SHOW THE 0C CONTOUR
RAIN/SNOW LINE PROXY THROUGH STATE COLLEGE ABOUT 5 PM. THIS
FEATURE STALL BETWEEN STATE COLLEGE AND HARRISBURG UNTIL ABOUT
MIDNIGHT.
MOST OF CENTRAL AND NORTHERN PENNSYLVANIA SHOULD SEE SNOW BY 7 PM
WITH SOME MIX OF ICE PELLETS AND FREEZING RAIN FARTHER SOUTH
BEFORE IT TRANSITIONS TO ALL RAIN IN THE LOWER SUSQUEHANNA VALLEY.
SOUTHEASTERN AREAS WILL REMAIN RAIN THIS EVENING.
...KEY POINT IN CENTRAL AND NORTH-CENTRAL PA IS RAPID RAIN TO SNOW
TRANSITION THIS EVENING...
&&
.SHORT TERM /9 PM THIS EVENING THROUGH 6 PM SATURDAY/...
BETWEEN ABOUT 9 PM AND 2 AM THERE WILL BE SOME MODERATE TO HEAVY
SNOW OVER MOST OF CENTRAL AND NORTHERN PENNSYLVANIA. THE SNOW
SHOULD LET UP A FEW HOURS AFTER MIDNIGHT. SREF AND GEFS HAVE
HEAVIER SNOW BAND NORTH OF THE 4KM RAP AND 4KM NAM. WARNINGS MAY
HAVE TO SLIDE SOUTH SHOULD UPDATED SREF/GEFS INDICATE A SIMILAR TREND.
WE WENT WITH THE HIGHER PROBABILITY FORECAST.
RAIN AND SNOW WITH FREEZING RAIN WILL SAG SOUTHWARD. EXTREME
SOUTHEASTERN AREAS LIKE HARRISBURG AND YORK SHOULD REMAIN ALL RAIN
AND MAY END WITH A BRIEF PERIOD OF FZDZ SATURDAY MORNING.
THE MODELS SUGGEST THE PRECIPITATION IS WELL TO OUR EAST A FEW
HOURS EITHER SIDE OF ABOUT 7 AM. SATURDAY WILL BE COLD BUT SHOULD
BE MOSTLY PRECIPITATION FREE.
LEFT SOME POST FRONTAL NW FLOW SNOW SHOWERS IN WESTERN AND
NORTHWESTERN MOUNTAINS SATURDAY.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
...THERE IS THE POTENTIAL FOR SIGNIFICANT FREEZING RAIN LATE
SUNDAY AND EARLY MONDAY IN THE SOUTHWEST MOUNTAINS....
...PREVIOUS DISCUSSION...1040+ MB MODIFIED ARCTIC SFC HIGH PRESSURE
OVER THE UPPER MIDWEST SATURDAY WILL MIGRATE EASTWARD INTO THE
NORTHERN MID- ATLANTIC STATES BY SUNDAY MORNING...SETTING THE
STAGE FOR WHAT APPEARS TO BE A CLASSIC OVERRUNNING MIXED PRECIP
EVENT FOR LATER SUNDAY INTO MONDAY.
05/12Z DETERMINISTIC MODEL AND ENSEMBLE GUIDANCE SHOWS LOW PRES
INITIALLY DEVELOPING ALONG AN INVERTED SFC TROUGH AXIS EXTENDING
FROM THE LWR MS/TN VLY NEWD UP THE WEST-SIDE OF THE APPALACHIANS.
THE MAIN LOW SHOULD LIFT NWD THRU THE OH VLY/GRT LKS INTO SERN
CANADA ON DAYS 5-6. MEANWHILE A SECONDARY/WEAKER AREA OF LOW PRES
SHOULD FORM NEAR THE VA/NC COAST AND TRACK NNEWD JUST OFFSHORE SRN
NEW ENGLAND.
DOWNSTREAM FROM A VIGOROUS MID/UPPER LEVEL TROUGH DIGGING THROUGH
THE FOUR CORNERS/SRN ROCKIES...A SURGE OF INTENSE 850-700MB WARM
AIR/THETA E/MOISTURE ADVECTION WILL SPREAD QUICKLY NEWD BEHIND A
BROAD SWLY FLOW ALOFT AND OVERRUN A RETREATING COLD SECTOR
ASSOCIATED WITH THE RETREATING ARCTIC HIGH. THE SYNOPTIC PATTERN
LOOKS VERY CONDUCIVE FOR A PERIOD OF FREEZING-TO-FROZEN PCPN AS
MSTR AND STG WAA ALOFT FLOWS OVER THE TOP OF A SHALLOW SUB-FZG
AIRMASS THAT SHOULD REMAIN ENTRENCHED ALONG/E OF THE ALLEGHENIES
VIA LLVL COLD AIR DAMMING/SFC PRES CHANNELING...ENHANCED BY NELY
AGEO FLOW AND WET BULB EFFECTS. SFC-850MB TEMPS ARE FCST TO WARM
ENOUGH TO CHANGE FREEZING PTYPES TO PLAIN RAIN IN MOST AREAS
AROUND MON AFTN BEFORE THE ARCTIC COLD FRONT CROSSES THE REGION
MON NGT. THE 12Z GEFS MEAN SHOWS A HIGH PROBABILITY OF A FEW
INCHES OF SNOW/SLEET ON THE LEADING EDGE OF THE PRECIP SHIELD
FOLLOWED BY POTENTIAL SIGNIFICANT ICE ACCUMS ESPECIALLY FROM THE
LAURELS/SCNTRL MTNS INTO THE INTERIOR N-CNTRL PART OF THE CWA.
WILL CONTINUE TO HIGHLIGHT THIS SYSTEM IN THE HWO BUT CONFIDENCE
IS INCREASING IN AT LEAST AN ADVISORY TYPE EVENT...IF NOT WARNING
ASSUMING MOD-HVY ICING VIA FZRA.
IN THE WAKE OF THIS SYSTEM...A VERY COLD PATTERN SHOULD GRIP THE
REGION THRU THE MIDDLE OF NEXT WEEK WITH TEMPERATURES WELL BELOW
NORMAL. SOME LAKE EFFECT SNOW SHOWERS ARE POSSIBLE IN THE COLD
CYC FLOW ALOFT ALTHOUGH THE LLVL WINDS MAY HAVE TOO MUCH OF A SW
COMPNT WHICH WOULD ORIENT BANDS MORE ALONG THE LAKE ERIE SHORE
INTO SW NY.
&&
.AVIATION /16Z FRIDAY THROUGH TUESDAY/...
SHOWERS CONTINUE TO STREAM ACROSS SOUTHERN AND CENTRAL PA WITH
LIGHT MIXED PRECIPITATION OVER JST AND BFD. THIS STEADY WAVE OF
RAIN MOVING THROUGH CENTRAL PA AND THE LOWER SUSQ WILL CONTINUE THROUGH
THE MORNING. CIGS FOR MOST TAF SITES HAVE LIFTED TO MVFR...AND
WILL REMAIN AROUND MVFR THROUGH THE MORNING AND EARLY AFTERNOON.
JST CURRENTLY HAS LIFR CIGS AND WILL SEE THESE CONTINUE THROUGH
THE MORNING AND EARLY AFTERNOON BEFORE SLIGHTLY LIFTING. THESE
WILL BE MVFR AND LOWER THROUGH TONIGHT. EXPECT THE MIXED
PRECIPITATION TO SWITCH TO RAIN THROUGH THE AFTERNOON HOURS
BEFORE SWITCHING TO A WINTRY MIX LATE THIS AFTERNOON AND SWITCHING
TO SNOW TONIGHT. EXPECT IFR CIGS AND VSBYS TO CONTINUE TONIGHT
INTO EARLY TOMORROW. MOST TAF SITES SHOULD BEGIN TO CLEAR EARLY
TOMORROW MORNING.
OUTLOOK...
FRI...MVFR IN RAIN SE. IFR IN SNOW/WINTRY MIX NW.
SAT...MVFR SNOW SHOWERS IN THE MOUNTAINS. VFR IN CENTRAL/EASTERN
AREAS.
SUN...REDUCTIONS DEVELOPING WITH APPROACHING STORM THAT WILL BRING
A WINTRY MIX SPREADING SOUTH TO NORTH INTO SUN NIGHT.
MON...WIDESPREAD MVFR/IFR ASSOCIATED WITH A PASSING COLD FRONT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ019-024>028-033>035-042-045-046-049>053.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ004>006-010>012-017-018-037-041.
&&
$$
SYNOPSIS...DEVOIR
NEAR TERM...GRUMM/STEINBUGL
SHORT TERM...GRUMM/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
239 AM EST FRI DEC 6 2013
.SYNOPSIS...
A SERIES OF LOW PRESSURE WAVES WILL TRACK NORTHEAST FROM THE
TENNESSEE VALLEY ACROSS THE MID-ATLANTIC STATES TONIGHT THROUGH
FRIDAY...BRINGING PERIODS OF MIXED PRECIPITATION TO THE AREA. HIGH
PRESSURE WILL PROVIDE A BRIEF RESPITE IN THE RECENTLY ACTIVE EARLY
SEASON WINTER WEATHER PATTERN ON SATURDAY. CONFIDENCE IS STEADILY
INCREASING FOR A PERIOD OF FROZEN AND FREEZING PRECIPITATION
SUNDAY INTO EARLY MONDAY THAT SHOULD EVENTUALLY CHANGE TO RAIN. AN
ARCTIC FRONTAL PASSAGE EARLY NEXT WEEK WILL DROP TEMPERATURES WELL
BELOW NORMAL THROUGH NEXT WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
FINE LINE ON KCCX RADAR SHOWING LOCATION OF COLD FRONT...JUST WEST
OF KUNV AND KAOO AT 0330Z. NEAR TERM MODELS AGREE IN TRACKING
COLD FRONT SE ACROSS THE AREA OVERNIGHT.
ALTHOUGH RAIN TAPERED OFF A BIT ACROSS CENTRAL PA EARLIER THIS
EVENING...REGIONAL RADAR MOSAIC SHOWING ANOTHER BATCH OF RAIN
APPROACHING FROM WESTERN PA AT 0330Z. UPSTREAM WATER VAPOR LOOP
SHOWS A SHORTWAVE OVR ILLINOIS AT 03Z...WHICH SHOULD LIFT NE
ACROSS THE E GRT LKS OVERNIGHT. LG SCALE FORCING AHEAD OF THIS
FEATURE SHOULD HELP SUPPORT NEXT BATCH OF PRECIP LATE THIS EVENING
THRU ARND 10Z. 02Z RAP FRONTOGENESIS PATTERNS MATCH WELL WITH
BAND OF SNOW FALLING FROM CENTRAL INDIANA TO NW OHIO. RAP INDICATES
THIS BAND OF ENHANCED FGEN LIFTS ACROSS NW PA BTWN 06Z-09Z AS MDL
SOUNDINGS BECOME COLD ENOUGH FOR SNOW. SO...BELIEVE A LIGHT SNOW
ACCUM IS POSSIBLE OVR WARREN/MCKEAN COS LATE TONIGHT.
FURTHER SOUTH...WILL RAMP UP CHC OF RAIN OVERNIGHT...AS SHORTWAVE
AND ASSOC LL JET/PLUME OF ANOMALOUS PWATS LIFTS THRU. BLEND OF
LATEST LAMP/RAP/NAM INDICATE TEMPS BEHIND CDFRONT WILL COAST
DOWNWARD TO THE U20S BY DAWN OVR THE NW MTNS...THE 30S MOST OF
CENTRAL PA...AND THE M40S ACROSS THE LOWER SUSQ VALLEY.
HAVE INCREASED WSPEEDS OVERNIGHT BASED ON UPSTREAM REPORTS AND
BUFKIT SOUNDINGS...WHICH SUPPORT A PERIOD OF GUSTS ARND 20KTS IN
IN THE NW FLOW IN WAKE OF FRONTAL PASSAGE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
NEXT SHORTWAVE LIFTING OUT OF THE S PLAINS WILL SPAWN A WAVE OF
LOW PRESSURE ALONG QUASI-STATIONARY SFC FRONT S OF PA ON FRIDAY
WITH ANOTHER SLUG OF PRECIP FOR FRIDAY AFTERNOON AND EVENING.
STRONG FRONTOGENETIC FORCING WILL DEVELOP UNDER THE ENTRANCE
REGION OF A VERY STRONG JET STREAK THAT WILL RACE DOWN THE ST
LAWRENCE RIVER VALLEY. THE BIGGEST ISSUE WITH THE SECOND WAVE WILL
BE THE AMOUNT OF WINTRY WEATHER ASSOCIATED. LATEST ENSEMBLE AND
OPER GUIDANCE SUGGESTS AIR MASS WILL BE COLD ENOUGH TO SUPPORT
SNOW ACROSS THE N COUNTIES...AS THE HEAVIEST PRECIP ARRIVES FRIDAY
AFTN. FURTHER SOUTH...LATEST MDL SOUNDINGS SUPPORT RAIN CHANGING
TO A WINTRY MIX ACROSS THE CENTRAL COUNTIES FRIDAY EVENING...AND
MAINLY RAIN OVER ABOUT THE SERN 1/3 OR SO OF MY FCST AREA.
BLENDED MDL QPF SUPPORTS A 3-5 INCH SNOWFALL ACROSS THE N
TIER...WITH JUST ENUF OF A WINTRY MIX OVER THE CENTRAL COUNTIES
TO POTENTIALLY CREATE SLIPPERY ROADS DURING THE EVENING. ACROSS
THE LAUREL HIGHLANDS...WARM AIR ALOFT SHOULD PRECLUDE MUCH SNOW.
HOWEVER...THE HIGHER TERRAIN DOWN THERE STILL LOOKS SUSCEPTIBLE TO
A PERIOD OF FZRA FRIDAY EVENING. HAVE THEREFORE...MOVED BACK THE
START TIME OF THEIR ADVISORY TO 22Z.
DEEPENING COLD AIR WILL ADVECT INTO THE STATE LATE FRIDAY NIGHT WITH
LINGERING LIGHT SNOW/MIXED PRECIP TAPERING OFF QUICKLY ARND
MIDNIGHT.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
1040+ MB MODIFIED ARCTIC SFC HIGH PRESSURE OVER THE UPPER MIDWEST
SATURDAY WILL MIGRATE EASTWARD INTO THE NORTHERN MID-ATLANTIC
STATES BY SUNDAY MORNING...SETTING THE STAGE FOR WHAT APPEARS TO
BE A CLASSIC OVERRUNNING MIXED PRECIP EVENT FOR LATER SUNDAY INTO
MONDAY.
05/12Z DETERMINISTIC MODEL AND ENSEMBLE GUIDANCE SHOWS LOW PRES
INITIALLY DEVELOPING ALONG AN INVERTED SFC TROUGH AXIS EXTENDING
FROM THE LWR MS/TN VLY NEWD UP THE WEST-SIDE OF THE APPALACHIANS.
THE MAIN LOW SHOULD LIFT NWD THRU THE OH VLY/GRT LKS INTO SERN
CANADA ON DAYS 5-6. MEANWHILE A SECONDARY/WEAKER AREA OF LOW PRES
SHOULD FORM NEAR THE VA/NC COAST AND TRACK NNEWD JUST OFFSHORE SRN
NEW ENGLAND.
DOWNSTREAM FROM A VIGOROUS MID/UPPER LEVEL TROUGH DIGGING THROUGH
THE FOUR CORNERS/SRN ROCKIES...A SURGE OF INTENSE 850-700MB WARM
AIR/THETA E/MOISTURE ADVECTION WILL SPREAD QUICKLY NEWD BEHIND A
BROAD SWLY FLOW ALOFT AND OVERRUN A RETREATING COLD SECTOR
ASSOCIATED WITH THE RETREATING ARCTIC HIGH. THE SYNOPTIC PATTERN
LOOKS VERY CONDUCIVE FOR A PERIOD OF FREEZING-TO-FROZEN PCPN AS
MSTR AND STG WAA ALOFT FLOWS OVER THE TOP OF A SHALLOW SUB-FZG
AIRMASS THAT SHOULD REMAIN ENTRENCHED ALONG/E OF THE ALLEGHENIES
VIA LLVL COLD AIR DAMMING/SFC PRES CHANNELING...ENHANCED BY NELY
AGEO FLOW AND WET BULB EFFECTS. SFC-850MB TEMPS ARE FCST TO WARM
ENOUGH TO CHANGE FREEZING PTYPES TO PLAIN RAIN IN MOST AREAS
AROUND MON AFTN BEFORE THE ARCTIC COLD FRONT CROSSES THE REGION
MON NGT. THE 12Z GEFS MEAN SHOWS A HIGH PROBABILITY OF A FEW
INCHES OF SNOW/SLEET ON THE LEADING EDGE OF THE PRECIP SHIELD
FOLLOWED BY POTENTIAL SIGNIFICANT ICE ACCUMS ESPECIALLY FROM THE
LAURELS/SCNTRL MTNS INTO THE INTERIOR N-CNTRL PART OF THE CWA.
WILL CONTINUE TO HIGHLIGHT THIS SYSTEM IN THE HWO BUT CONFIDENCE
IS INCREASING IN AT LEAST AN ADVISORY TYPE EVENT...IF NOT WARNING
ASSUMING MOD-HVY ICING VIA FZRA.
IN THE WAKE OF THIS SYSTEM...A VERY COLD PATTERN SHOULD GRIP THE
REGION THRU THE MIDDLE OF NEXT WEEK WITH TEMPERATURES WELL BELOW
NORMAL. SOME LAKE EFFECT SNOW SHOWERS ARE POSSIBLE IN THE COLD
CYC FLOW ALOFT ALTHOUGH THE LLVL WINDS MAY HAVE TOO MUCH OF A SW
COMPNT WHICH WOULD ORIENT BANDS MORE ALONG THE LAKE ERIE SHORE
INTO SW NY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
ARES OF SHOWERS WILL CONTINUE TO STREAM THROUGH THE REGION
OVERNIGHT. THIS STEADY WAVE OF RAIN MOVING THROUGH CENTRAL PA.
LIFR WILL CONTINUE OVER THE LOWER SUSQ TERMINALS WHERE FOG IS
STILL LOCALLY DENSE. OTHERWISE...MVFR AND LOWER FLIGHT CATEGORIES
WILL CONTINUE INTO THIS MORNING AS MORE RAIN...SNOW...AND WINTRY
MIX OVERSPREAD THE REGION.
OUTLOOK...
FRI...MVFR IN RAIN SE. IFR IN SNOW/WINTRY MIX NW.
SAT...MVFR SNOW SHOWERS IN THE MOUNTAINS. VFR IN CENTRAL/EASTERN
AREAS.
SUN...REDUCTIONS DEVELOPING WITH APPROACHING STORM THAT WILL BRING
A WINTRY MIX SPREADING SOUTH TO NORTH INTO SUN NIGHT.
MON...WIDESPREAD MVFR/IFR ASSOCIATED WITH A PASSING COLD FRONT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ004>006-010>012-017-018-037-041-042.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM EST
SATURDAY FOR PAZ024-033.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...CERU/GARTNER
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
1153 PM EST THU DEC 5 2013
.SYNOPSIS...
A SERIES OF LOW PRESSURE WAVES WILL TRACK NORTHEAST FROM THE
TENNESSEE VALLEY ACROSS THE MID-ATLANTIC STATES TONIGHT THROUGH
FRIDAY...BRINGING PERIODS OF MIXED PRECIPITATION TO THE AREA. HIGH
PRESSURE WILL PROVIDE A BRIEF RESPITE IN THE RECENTLY ACTIVE EARLY
SEASON WINTER WEATHER PATTERN ON SATURDAY. CONFIDENCE IS STEADILY
INCREASING FOR A PERIOD OF FROZEN AND FREEZING PRECIPITATION
SUNDAY INTO EARLY MONDAY THAT SHOULD EVENTUALLY CHANGE TO RAIN. AN
ARCTIC FRONTAL PASSAGE EARLY NEXT WEEK WILL DROP TEMPERATURES WELL
BELOW NORMAL THROUGH NEXT WEDNESDAY.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
FINE LINE ON KCCX RADAR SHOWING LOCATION OF COLD FRONT...JUST WEST
OF KUNV AND KAOO AT 0330Z. NEAR TERM MODELS AGREE IN TRACKING
COLD FRONT SE ACROSS THE AREA OVERNIGHT.
ALTHOUGH RAIN TAPERED OFF A BIT ACROSS CENTRAL PA EARLIER THIS
EVENING...REGIONAL RADAR MOSAIC SHOWING ANOTHER BATCH OF RAIN
APPROACHING FROM WESTERN PA AT 0330Z. UPSTREAM WATER VAPOR LOOP
SHOWS A SHORTWAVE OVR ILLINOIS AT 03Z...WHICH SHOULD LIFT NE
ACROSS THE E GRT LKS OVERNIGHT. LG SCALE FORCING AHEAD OF THIS
FEATURE SHOULD HELP SUPPORT NEXT BATCH OF PRECIP LATE THIS EVENING
THRU ARND 10Z. 02Z RAP FRONTOGENESIS PATTERNS MATCH WELL WITH
BAND OF SNOW FALLING FROM CENTRAL INDIANA TO NW OHIO. RAP INDICATES
THIS BAND OF ENHANCED FGEN LIFTS ACROSS NW PA BTWN 06Z-09Z AS MDL
SOUNDINGS BECOME COLD ENOUGH FOR SNOW. SO...BELIEVE A LIGHT SNOW
ACCUM IS POSSIBLE OVR WARREN/MCKEAN COS LATE TONIGHT.
FURTHER SOUTH...WILL RAMP UP CHC OF RAIN OVERNIGHT...AS SHORTWAVE
AND ASSOC LL JET/PLUME OF ANOMALOUS PWATS LIFTS THRU. BLEND OF
LATEST LAMP/RAP/NAM INDICATE TEMPS BEHIND CDFRONT WILL COAST
DOWNWARD TO THE U20S BY DAWN OVR THE NW MTNS...THE 30S MOST OF
CENTRAL PA...AND THE M40S ACROSS THE LOWER SUSQ VALLEY.
HAVE INCREASED WSPEEDS OVERNIGHT BASED ON UPSTREAM REPORTS AND
BUFKIT SOUNDINGS...WHICH SUPPORT A PERIOD OF GUSTS ARND 20KTS IN
IN THE NW FLOW IN WAKE OF FRONTAL PASSAGE.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
NEXT SHORTWAVE LIFTING OUT OF THE S PLAINS WILL SPAWN A WAVE OF
LOW PRESSURE ALONG QUASI-STATIONARY SFC FRONT S OF PA ON FRIDAY
WITH ANOTHER SLUG OF PRECIP FOR FRIDAY AFTERNOON AND EVENING.
STRONG FRONTOGENETIC FORCING WILL DEVELOP UNDER THE ENTRANCE
REGION OF A VERY STRONG JET STREAK THAT WILL RACE DOWN THE ST
LAWRENCE RIVER VALLEY. THE BIGGEST ISSUE WITH THE SECOND WAVE WILL
BE THE AMOUNT OF WINTRY WEATHER ASSOCIATED. LATEST ENSEMBLE AND
OPER GUIDANCE SUGGESTS AIR MASS WILL BE COLD ENOUGH TO SUPPORT
SNOW ACROSS THE N COUNTIES...AS THE HEAVIEST PRECIP ARRIVES FRIDAY
AFTN. FURTHER SOUTH...LATEST MDL SOUNDINGS SUPPORT RAIN CHANGING
TO A WINTRY MIX ACROSS THE CENTRAL COUNTIES FRIDAY EVENING...AND
MAINLY RAIN OVER ABOUT THE SERN 1/3 OR SO OF MY FCST AREA.
BLENDED MDL QPF SUPPORTS A 3-5 INCH SNOWFALL ACROSS THE N
TIER...WITH JUST ENUF OF A WINTRY MIX OVER THE CENTRAL COUNTIES
TO POTENTIALLY CREATE SLIPPERY ROADS DURING THE EVENING. ACROSS
THE LAUREL HIGHLANDS...WARM AIR ALOFT SHOULD PRECLUDE MUCH SNOW.
HOWEVER...THE HIGHER TERRAIN DOWN THERE STILL LOOKS SUSCEPTIBLE TO
A PERIOD OF FZRA FRIDAY EVENING. HAVE THEREFORE...MOVED BACK THE
START TIME OF THEIR ADVISORY TO 22Z.
DEEPENING COLD AIR WILL ADVECT INTO THE STATE LATE FRIDAY NIGHT WITH
LINGERING LIGHT SNOW/MIXED PRECIP TAPERING OFF QUICKLY ARND
MIDNIGHT.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
1040+ MB MODIFIED ARCTIC SFC HIGH PRESSURE OVER THE UPPER MIDWEST
SATURDAY WILL MIGRATE EASTWARD INTO THE NORTHERN MID-ATLANTIC
STATES BY SUNDAY MORNING...SETTING THE STAGE FOR WHAT APPEARS TO
BE A CLASSIC OVERRUNNING MIXED PRECIP EVENT FOR LATER SUNDAY INTO
MONDAY.
05/12Z DETERMINISTIC MODEL AND ENSEMBLE GUIDANCE SHOWS LOW PRES
INITIALLY DEVELOPING ALONG AN INVERTED SFC TROUGH AXIS EXTENDING
FROM THE LWR MS/TN VLY NEWD UP THE WEST-SIDE OF THE APPALACHIANS.
THE MAIN LOW SHOULD LIFT NWD THRU THE OH VLY/GRT LKS INTO SERN
CANADA ON DAYS 5-6. MEANWHILE A SECONDARY/WEAKER AREA OF LOW PRES
SHOULD FORM NEAR THE VA/NC COAST AND TRACK NNEWD JUST OFFSHORE SRN
NEW ENGLAND.
DOWNSTREAM FROM A VIGOROUS MID/UPPER LEVEL TROUGH DIGGING THROUGH
THE FOUR CORNERS/SRN ROCKIES...A SURGE OF INTENSE 850-700MB WARM
AIR/THETA E/MOISTURE ADVECTION WILL SPREAD QUICKLY NEWD BEHIND A
BROAD SWLY FLOW ALOFT AND OVERRUN A RETREATING COLD SECTOR
ASSOCIATED WITH THE RETREATING ARCTIC HIGH. THE SYNOPTIC PATTERN
LOOKS VERY CONDUCIVE FOR A PERIOD OF FREEZING-TO-FROZEN PCPN AS
MSTR AND STG WAA ALOFT FLOWS OVER THE TOP OF A SHALLOW SUB-FZG
AIRMASS THAT SHOULD REMAIN ENTRENCHED ALONG/E OF THE ALLEGHENIES
VIA LLVL COLD AIR DAMMING/SFC PRES CHANNELING...ENHANCED BY NELY
AGEO FLOW AND WET BULB EFFECTS. SFC-850MB TEMPS ARE FCST TO WARM
ENOUGH TO CHANGE FREEZING PTYPES TO PLAIN RAIN IN MOST AREAS
AROUND MON AFTN BEFORE THE ARCTIC COLD FRONT CROSSES THE REGION
MON NGT. THE 12Z GEFS MEAN SHOWS A HIGH PROBABILITY OF A FEW
INCHES OF SNOW/SLEET ON THE LEADING EDGE OF THE PRECIP SHIELD
FOLLOWED BY POTENTIAL SIGNIFICANT ICE ACCUMS ESPECIALLY FROM THE
LAURELS/SCNTRL MTNS INTO THE INTERIOR N-CNTRL PART OF THE CWA.
WILL CONTINUE TO HIGHLIGHT THIS SYSTEM IN THE HWO BUT CONFIDENCE
IS INCREASING IN AT LEAST AN ADVISORY TYPE EVENT...IF NOT WARNING
ASSUMING MOD-HVY ICING VIA FZRA.
IN THE WAKE OF THIS SYSTEM...A VERY COLD PATTERN SHOULD GRIP THE
REGION THRU THE MIDDLE OF NEXT WEEK WITH TEMPERATURES WELL BELOW
NORMAL. SOME LAKE EFFECT SNOW SHOWERS ARE POSSIBLE IN THE COLD
CYC FLOW ALOFT ALTHOUGH THE LLVL WINDS MAY HAVE TOO MUCH OF A SW
COMPNT WHICH WOULD ORIENT BANDS MORE ALONG THE LAKE ERIE SHORE
INTO SW NY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
NEXT WAVE OF STEADY RAIN MOVING INTO CENTRAL PA ATTM. THIS WILL
LEAD TO SOME IMPROVEMENT OF LIFR VSBYS...AT LEAST FOR AT TIME
WHILE IT IS RAINING OVER THE NEXT SEVERAL HOURS. UNTIL STEADIER
RAIN REACHES EAST...LIFR WILL CONTINUE OVER THE LOWER SUSQ
TERMINALS WHERE FOG IS STILL LOCALLY DENSE. OTHERWISE...MVFR AND LOWER
FLIGHT CATEGORIES WILL CONTINUE INTO FRIDAY AS MORE
RAIN...SNOW...AND WINTRY MIX OVERSPREAD THE REGION.
OUTLOOK...
FRI...MVFR IN RAIN SE. IFR IN SNOW/WINTRY MIX NW.
SAT...MVFR SNOW SHOWERS IN THE MOUNTAINS. VFR IN CENTRAL/EASTERN
AREAS.
SUN...REDUCTIONS DEVELOPING WITH APPROACHING STORM THAT WILL BRING
A WINTRY MIX SPREADING SOUTH TO NORTH INTO SUN NIGHT.
MON...WIDESPREAD MVFR/IFR ASSOCIATED WITH A PASSING COLD FRONT.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 1 PM FRIDAY TO 5 AM EST SATURDAY
FOR PAZ004>006-010>012-017-018-037-041-042.
WINTER WEATHER ADVISORY FROM 5 PM FRIDAY TO 5 AM EST SATURDAY
FOR PAZ024-033.
&&
$$
SYNOPSIS...LA CORTE
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD/LA CORTE/STEINBUGL
LONG TERM...STEINBUGL
AVIATION...GARTNER/COLBERT
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1140 PM CST THU DEC 5 2013
.DISCUSSION...
SEE THE 06Z AVIATION DISCUSSION BELOW.
40
&&
.AVIATION...
MAIN FORECAST ITEMS OF CONCERN WILL BE CEILINGS AND WINDS. MODEL
FORECAST SOUNDINGS KEEP IFR THROUGH FRIDAY MORNING...WITH THE
CEILINGS LIFTING TO MVFR DURING THE AFTERNOON PERIOD. THE
SOUNDINGS DO NOT SUPPORT MUCH IN THE WAY OF CONVECTION...AND FELT
LIGHT DRIZZLE WILL MOST LIKELY OCCUR. WINDS ALONG THE COAST WILL
LIKELY GUST TO ABOVE 25 KNOTS OVERNIGHT TONIGHT AND SHOULD PERSIST
AT KGLS THROUGH FRIDAY AFTERNOON.
THE GUIDANCE SUGGESTS MVFR CONDITIONS LIFTING FRIDAY EVENING FROM
ABOUT HOUSTON SOUTH TO THE COAST. HOWEVER...THE MODEL FORECAST
SOUNDINGS INDICATE THAT MVFR CONDITIONS WILL LIKELY LOWER TOWARD
IFR DURING THE LATE EVENING. WITH COLD AIR ADVECTION COUPLED WITH
THE STRENGTHENING SURFACE PRESSURE GRADIENT...THE WINDS ALONG THE
IMMEDIATE COAST WILL LIKELY STRENGTHEN FRIDAY EVENING TO GUST TO
AROUND 30 KNOTS AT KGLS BEGINNING AROUND 00Z. OVER THE INLAND
SITES...FELT THAT THE GUIDANCE WAS ON TRACK IN DIMINISHING THE
WIND GUSTS AROUND SUNSET.
40
&&
.PREV DISCUSSION... /ISSUED 928 PM CST THU DEC 5 2013/
UPDATE...
UPDATE TO ISSUE A WIND ADVISORY FOR THE COASTAL COUNTIES.
DISCUSSION...
WIND SPEEDS HAVE INCREASED AND WIND ADVISORY CRITERIA HAS BEEN
MET ALONG THE COAST. A WIND ADVISORY WILL BE IN EFFECT THROUGH 4
AM FOR THE COASTAL COUNTIES.
CONCERN IS GROWING FOR WINTER PRECIP OVER THE NW ZONES TONIGHT.
TEMPS ARE GETTING DANGEROUSLY CLOSE TO FREEZING. JACKSONVILLE AND
PALASTINE ARE BOTH REPORTING SLEET. SFC DEW PTS CONTINUE TO DROP
AND AM CONCERNED ABOUT EVAPORATIVE COOLING LOWERING SFC TEMPS TO
NEAR OR JUST BELOW FREEZING. NAM 12 FCST SOUNDINGS SHOW SFC TEMPS
FALLING TO 32 DEGREES AT 09Z AND 31 DEGREES 12Z-18Z. THE NAM12 SFC
DEW PT FIELD IS WARMER SO THERE ARE CONFLICTING SIGNALS BETWEEN
SFC PARAMETERS AND SOUNDING PARAMETERS. AM STRONGLY CONSIDERING A
WINTER WEATHER ADVISORY FOR AREAS NW OF A CALDWELL TO CROCKETT
LINE FOR OVERNIGHT INTO FRI MORNING. 43
PREV DISCUSSION... /ISSUED 805 PM CST THU DEC 5 2013/
UPDATE...
SEE EVENING UPDATE.
DISCUSSION...
AT 01Z...A COLD FRONT EXTENDED FROM SOUTH CENTRAL LOUISIANA
ACROSS THE WESTERN GULF. A VERY TIGHT PRESSURE GRADIENT IS IN
PLACE AND WIND SPEEDS ARE APPROACHING ADVISORY CRITERIA. WILL
WATCH TRENDS BUT WILL HOLD OFF ON A WIND ADVISORY FOR THE COASTAL
COUNTIES FOR NOW. WATER TEMPS HAVE COOLED A BIT SINCE THE LAST
FROPA...SO FEEL THERMAL CONTRIBUTION TO WINDS WILL BE LESS THAN
PAST COUPLE OF EVENTS. RAP GUIDANCE ALSO SUGGESTS THAT WINDS WILL
REMAIN BELOW ADVISORY CRITERIA.
POPS ARE RATHER HIGH CONSIDERING THE RADAR LOOKS SO BENIGN AT THE
CURRENT TIME. 00Z 850 MB ANALYSIS SHOWS WINDS STILL OUT OF THE
SOUTH WITH AN 850 MB FRONT EXTENDING FROM TEXARKANA TO ABOUT
LAREDO. ISENTROPIC UPGLIDE HAS NOT REALLY KICKED IN YET AS NORTH
WINDS REMAIN VERY SHALLOW. THIS SHOULD CHANGE OVERNIGHT AS THE
850 MB FRONT CLEARS THE COAST. 00Z SOUNDINGS SHOW A SATURATED
LAYER FROM THE SURFACE TO 850 MB...AND VERY DRY AIR ABOVE THE
SATURATED LAYER. NAM12 AND RAP FORECAST SOUNDINGS CLOSELY MATCH
THE 00Z SOUNDINGS. THIS TYPE OF SOUNDING FAVORS DRIZZLE OVER RAIN.
EITHER WAY...EXPECT CONDS TO BECOME INCREASINGLY DAMP OVERNIGHT.
TEMP FCST LOOKS TO BE ON TRACK. NOT EXPECTING FREEZING TEMPS
OVERNIGHT BUT CALDWELL (RWV) IS GETTING CLOSE. CURRENT TEMP AT RWV
IS 34 DEGREES WITH A DEW PT OF 30. HAVE SOME CONCERN THAT DEW
POINTS NEAR 30 WILL ALLOW FOR SOME EVAPORATIVE COOLING ONCE PRECIP
BEGINS AND THEN INSTEAD OF DRIZZLE...WE GET FREEZING DRIZZLE.
WILL AGAIN WATCH TRENDS BUT FEEL CURRENT FCST HAS A GOOD HANDLE
ON TONIGHT`S TEMP/PRECIP TRENDS. HAVE MADE MINOR CHANGES TO THE
GRIDS. NEW ZFP OUT BY 900 PM. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 33 35 27 34 31 / 60 70 10 40 40
HOUSTON (IAH) 38 39 33 38 33 / 40 70 20 50 50
GALVESTON (GLS) 46 48 37 45 40 / 40 70 20 50 40
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...WIND ADVISORY UNTIL 4 AM CST FRIDAY FOR THE FOLLOWING ZONES:
BRAZORIA...CHAMBERS...GALVESTON...JACKSON...MATAGORDA.
GM...SMALL CRAFT ADVISORY UNTIL 6 PM CST FRIDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...MATAGORDA BAY...WATERS FROM FREEPORT
TO THE MATAGORDA SHIP CHANNEL 20 NM TO 60 NM...WATERS FROM
FREEPORT TO THE MATAGORDA SHIP CHANNEL OUT 20 NM...WATERS
FROM HIGH ISLAND TO FREEPORT 20 TO 60 NM...WATERS FROM HIGH
ISLAND TO FREEPORT OUT 20 NM.
&&
$$
DISCUSSION...43
AVIATION/MARINE...40
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1149 PM EST THU DEC 5 2013
.SYNOPSIS...
A SLOW MOVING COLD FRONT MOVES EAST INTO THE APPALACHIANS
TONIGHT. THE BOUNDARY CRAWLS ACROSS VIRGINIA ON FRIDAY. ARCTIC
HIGH PRESSURE WELL BEHIND THE FRONT WILL WEDGE SOUTH ALONG THE
MOUNTAINS SATURDAY...BEFORE INTERACTING WITH PRECIPITATION
RETURNING NORTH BY SUNDAY. SOUTHWESTERLY FLOW RETURNS MONDAY
BEFORE A STRONGER COLD FRONT ARRIVES LATE MONDAY NIGHT.
&&
.NEAR TERM /THROUGH FRIDAY/...
AS OF 745 PM EST THURSDAY...
A STRONG COLD FRONT LOCATED TO OUR WEST THIS AFTERNOON FROM CLE TO
LEX TO MEM WILL MOVE EAST TONIGHT INTO FRIDAY. WEAK SHORTWAVES MOVE
NORTHEAST IN THE WARM SECTION WILL RESULT IN SCATTERED SHOWERS.
INCREASED PROBABILITY OF PRECIPITATION IN THE FAR NORTHWEST COUNTY
WARNING AREA AND LEANED POPS THIS EVENING INTO TONIGHT TOWARDS A
BLEND OF THE LATEST RAP AND RNKWRFARW. THE GFS ALSO SHOWED SOME
LIGHT PRECIPITATION ALONG THE SOUTHERN BLUE RIDGE MOUNTAINS INTO
SOUTHERN VIRGINIA. THE MAIN BODY OF RAINFALL SHOULD REMAIN WILL
REMAIN TO OUR WEST TONIGHT.
A VERY WARM AND MUGGY OVERNIGHT EXPECTED WITH READINGS FROM
AROUND 50 DEGREES IN THE NORTHWEST MOUNTAINS TO THE LOWER 60S IN
THE SOUTHEAST.
SURFACE COLD FRONT WILL BE ENTERING THE MOUNTAINS FRIDAY WITH A WAVE
OF LOW PRESSURE WHICH DEVELOPS ALONG THE BOUNDARY AND RIPPLE
NORTHEAST ACROSS THE REGION. MAIN AXIS OF RAIN SHOULD BE FOCUSED
ALONG AND JUST WEST OF THE FRONTAL BOUNDARY FRIDAY. FELT THERE WAS
ENOUGH INSTABILITY TO INCLUDE THE MENTION OF AN ISOLATED
THUNDERSTORMS MAINLY WEST OF I77. PLAYED HIGH TEMPERATURES CLOSE
TO THE ADJMAVBC WITH VALUES FROM THE LOWER 50S IN THE MOUNTAINS TO
THE MID 70S IN THE PIEDMONT.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY NIGHT/...
AS OF 315 PM EST THURSDAY...
NOT A LOT OF CHANGE EARLY ON WITH THE SLOW MOVING COLD FRONT AND
ASSOCIATED WAVE CROSSING THE REGION FROM THE NW FRIDAY NIGHT AND
SPILLING SOUTH OF THE AREA EARLY SATURDAY. MODELS AGAIN WEAKEN THE
AXIS OF LIFT ALONG/BEHIND THE FRONT FRIDAY EVENING WITH HEAVIEST QPF
AND HIGHEST POPS ALONG THE WESTERN SLOPES THROUGH LATE
EVENING...THEN LESS ALONG/EAST OF THE BLUE RIDGE EXCEPT SE WHERE THE
BOUNDARY MAY STALL AND THE LOW LEVEL NE FLOW MAY ENHANCE SHOWERS
LATE. STILL APPEARS ENOUGH MOISTURE ACROSS THE NW LATE FRIDAY NIGHT
TO WARRANT KEEPING IN SOME LIGHT MIX MENTION AT ELEVATION BUT
OVERALL THINK ANYTHING FROZEN AT THIS POINT QUITE SPOTTY ACROSS SE
WVA. COLD AIR WILL BE SLIDING IN FROM THE NORTH/WEST ALTHOUGH TEMPS
MAY ACTUALLY GET COLDER AFTER DAYBREAK SATURDAY WHEN THE BETTER 85H
COLD ADVECTION ARRIVES.
GUIDANCE HAS CONTINUED THE TREND FROM YESTERDAY IN PUSHING THE
DEEPER MOISTURE TO THE SE SATURDAY AS THE LARGE ARCTIC HIGH BUILDS
IN FROM THE NW AND INITIALLY GIVES THE MOISTURE A PUSH. MAY SEE THE
ENTIRE CWA GO DRY BY SATURDAY AFTERNOON BUT FOR NOW LEAVING IN SOME
POP MAINLY EASTERN HALF THROUGH MIDDAY AND MAINLY FAR SE LATE IN THE
DAY. COULD EVEN HAVE SOME CLEARING TAKE PLACE NW PENDING HOW STRONG
THE DRY ADVECTION IS SO CUT BACK ON CLOUD COVER SOME NORTH HALF
DURING THE AFTERNOON. HIGHS CHILLY WITH LOW LEVEL NORTH/NW FLOW WITH
TEMPS 30S WEST TO 40S/NEAR 50 FAR SOUTH.
MAIN CONCERN THEN WITH THE POTENTIAL FOR A SIGNIFICANT WINTER EVENT
FROM VERY LATE SAT NIGHT INTO SUNDAY AND PERHAPS SUNDAY NIGHT ACROSS
THE NORTH. LATEST GUIDANCE HAS AGAIN SLOWED THINGS UP A BIT WITH
LOTS OF COLD/DRY AIR SLIDING DOWN EAST OF THE BLUE RIDGE AS THE
STRONG WEDGE DEVELOPS WITH THE HIGH BUILDING FARTHER SOUTH. THIS
WILL MAKE FOR COLDER TEMPS SAT NIGHT BEFORE THICKENING CLOUDS AND
LIGHT PRECIP RETURN FROM THE SOUTH/SW AFTER MIDNIGHT PER ISENTROPIC
LIFT AHEAD OF ANOTHER WAVE HEADING UP WEST OF THE MOUNTAINS.
LATEST FORECAST SOUNDINGS SHOW DRY AIR HOLDING LONGER WITH PRECIP
NOT REACHING INTO THE SOUTHERN HALF OF THE AREA UNTIL AFTER MIDNIGHT
AND POINTS NORTH SUNDAY AROUND DAYBREAK. PRECIP THEN LOOKS TO
ACCELERATE INTO THE WEDGE SUNDAY MORNING FROM THE SW BUT REMAIN
INCONSISTENT IN QPF AMOUNTS WHICH ARE CRITICAL GIVEN COLDER PROFILES
FROM 12Z RUNS. HOWEVER MOST SHOWING THE BEST LIFT WITH A WARM
FRONT ALOFT TYPE FEATURE THAT DEVELOPS OVER THE CENTRAL/NORTHERN
CWA SUNDAY MORNING AND SHIFTS NORTH DURING THE AFTERNOON LEAVING
MORE SPOTTY NATURE PRECIP ELSW INTO SUNDAY EVENING. BOTH THE NAM
AND GFS ARE COLDER THAN THE EARLIER SOLNS WITH LESS OF A WARM NOSE
EARLY ON AND DEEPER LOW LEVEL COLD AIR SUPPORTIVE OF MORE OF A
SNOW/SLEET MIX AT THE ONSET ESPCLY HIWAY 460 NORTH. THUS INCLUDING
SOME LIGHT ACCUMULATIONS NW SUNDAY MORNING AS THINGS REMAIN BELOW
FREEZING AT 85H AND THINGS BECOME MORE ISOTHERMAL UNTIL THE
STRONGER WARM ADVECTION ARRIVES IN THE AFTERNOON. SOME SLEET ALSO
POSSIBLE ELSW AS THINGS WET BULB DOWN AT THE ONSET BUT THINKING
MORE OF A PROLONGED FREEZING RAIN EVENT ESPCLY SRN BLUE RIDGE AND
ACROSS THE VA COUNTIES SOUTH OF 460. WEDGE MAY BE ENOUGH TO FORCE
TEMPS DOWN ENOUGH TO PRODUCE SOME SPOTTY FZRA INTO NW NC BUT
HOLDING OFF GOING THAT COLD ATTM. OTRW FEW CHANGES TO HIGH POPS
SUNDAY WITH HIGH POPS FOR LOW QPF SUNDAY NIGHT WHEN THE GREENBRIER
VALLEY AND SRN SHENANDOAH VALLEY MAY HOLD ONTO FREEZING RAIN
OVERNIGHT. SINCE MOSTLY A 6TH PERIOD AND BEYOND EVENT...WILL HOLD
OFF ON HEADLINES FOR NOW AND KEEP MENTION IN THE HWO.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 350 PM EST THURSDAY...
COMPLICATED FORECAST CONTINUES THROUGH THE EXTENDED PERIODS AS
SOUTHWEST FLOW ALOFT CONTINUES ACROSS THE REGION AT THE SAME TIME
ARCTIC AIR CONTINUES TO STREAM SOUTHEASTWARD FROM WESTERN/CENTRAL
CANADA INTO THE CENTRAL AND EASTERN U.S. OUR REGION REMAINS ON OR
NEAR THE BOUNDARY BETWEEN THE ARCTIC AIR AND THE WARMER AIR TO THE
SOUTHEAST...HOWEVER...THROUGH THE LONGER TERM PERIODS IT APPEARS
THAT THE ARCTIC AIR WILL WIN OUT ACROSS OUR REGION AND THE FRONTAL
WILL FINALLY BE PUSHED INTO THE SE STATES AS THE UPPER FLOW
FINALLY BECOMES NW.
MON MORNING WE ARE STILL DEALING WITH THE END OF THE POTENTIAL
SIGNIFICANT ICING EVENT ADDRESSED IN THE SHORT TERM PERIODS AS THE
WEDGE BOUNDARY FINALLY LIFTS INTO NORTHERN VA. MODELS HAVE
CONTINUED TO TREND COLDER...WHICH REQUIRES HOLDING ONTO THE -FZRA
A FEW MORE HOURS INTO MID-MORNING MONDAY THAN EARLIER INDICATED.
WILL CHANGE ALL PRECIPITATION TO -RA BY 15Z MON AS THE FORECAST
AREA BRIEFLY MOVES INTO A WARM SECTOR SANDWICHED BETWEEN THE
RETREATING COLD AIR WEDGE AND THE NEXT SURGE OF ARCTIC AIR TO THE
WEST. THROUGH THE DAYLIGHT HOURS...WE SHOULD SEE ONLY LIQUID PCPN
ACROSS THE REGION.
BY 06Z TUE...THE NEXT SURGE OF ARCTIC AIR SHOULD MOVE INTO OUR WV
COUNTIES AND OUR FAR SW VA CONTINUES. GIVEN THE STRENGTH OF THIS
SECOND SURGE OF COLD AIR...WOULD EXPECT -RA TO QUICKLY CHANGE TO
-SN FROM WEST TO EAST DURING THE EVENING. AT THE SAME TIME...THE
DEEPER MOISTURE IS SHIFTING EAST INTO THE PIEDMONT WHERE AT THIS
POINT IT SHOULD STILL BE WARM ENOUGH FOR MOSTLY -RA. THUS...SNOW
ACCUMULATIONS OUTSIDE MOUNTAIN UPSLOPE -SHSN EASTERN WV...SHOULD
BE MINIMAL...BUT COULD NOT RULE OUT AN INCH OR SO IN SOME SPOTS
WEST OF I-81/I-77. THERE IS CONSIDERABLE DISCREPANCY BETWEEN THE
GFS/ECMWF IN THIS TIME FRAME...WITH THE ECMWF PUSHING THE MOISTURE
WELL EAST OF THE CWA BEFORE ANY APPRECIABLE COLD AIR MOVES INTO
THE REGION FROM THE WEST...WHILE THE GFS TRIES TO MOVE YET A THIRD
WAVE ALONG THE FRONTAL BOUNDARY ACROSS THE REGION FROM THE SW.
GIVEN THE OVERALL CONFLUENT FLOW IN THIS TIME FRAME...NOT
EXPECTING ANY SIGNIFICANT PCPN OR MORE IMPORTANTLY WINTER WX
ISSUES. AGAIN...HOWEVER...THERE WILL BE MOUNTAIN UPSLOPE
-SHSN...WITH MINOR SNOW ACCUMULATIONS EASTERN WV COUNTIES INTO FAR
SW VA AND THE NW NC MOUNTAINS.
FOR THE REMAINDER OF THE EXTENDED...AT THIS POINT IT APPEARS DRY.
THE CENTER OF THE ARCTIC AIR MASS DRIFTS OVER THE REGION BY THU
WITH A VERY DRY/COLD AIR MASS. AGAIN...THERE ARE CONSIDERABLE
DIFFERENCES BETWEEN THE ECMWF AND GFS WITH RESPECT TO TEMPERATURES
IN THIS TIME FRAME. GIVEN THE STRENGTH OF THIS ARCTIC AIR
MASS...HAVE LEANED HEAVILY TOWARD THE COLDER GFS. THE COLDEST DAY
SHOULD BE THU WHEN THE ARCTIC HIGH IS CENTERED RIGHT OVER THE CWA.
WOULD NOT BE THE LEAST SURPRISED TO SEE MIN TEMPERATURES IN THE
SINGLE DIGITS IN LOCATIONS SUCH AS LWB. HOWEVER...THE PREVAILING
WEST AS OPPOSED TO A STRONG NW-N FLOW ALOFT SHOULD RESULT IN THE
COLDER AIR REMAINING NORTH AND WEST OF THE CWA..SO WE SHOULD STAY
AOA 20 DEGREES FOR MINS ACROSS THE PIEDMONT. ANY PRECIPITATION
WED-FRI SHOULD BE CONFINED TO UPSLOPE MOUNTAIN -SHSN WITH DRIER
DOWNSLOPE WEST FLOW EAST OF THE ALLEGHANYS. EVEN ACROSS EASTERN
WV...SNOW ACCUMULATIONS SHOULD BE FAIRLY LIMITED WITH OVERALL
SNOW ACCUMULATIONS THERE EVEN AN INCH OR LESS.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
AS OF 1145 PM EST THURSDAY...
STRONG COLD FRONT WILL BE APPROACHING FROM THE OHIO VALLEY...STALLING
WEST OF THE APPALACHIAN MOUNTAINS TONIGHT. A BROAD BAND OF RAIN
FROM CENTRAL PENNSYLVANIA TO CENTRAL TENNESSEE WILL BRING RAIN
WITH MVFR VISIBILITIES TO KLWB AND KBLF TONIGHT. STRATUS AND FOG
WITH SCATTERED SHOWERS IS EXPECTED FOR THE REST OF THE AREA.
CEILINGS WERE ALREADY MVFR AT 00Z/7PM. HIGH CONFIDENCE THAT
KROA...KBCB...KLYH AND KDAN WILL LOWER TO IFR OR LIFR OVERNIGHT WITH
MVFR FOG. LITTLE IMPROVEMENT IS EXPECTED ON FRIDAY. CEILINGS WILL
REMAIN IN THE IFR TO MVFR RANGE WITH RAIN BECOMING MORE
WIDESPREAD...ESPECIALLY IN THE LATE AFTERNOON AND EVENING.
EXTENDED AVIATION...A COLD FRONT WILL MAKE SLOW PROGRESS ACROSS
THE AREA LATE FRIDAY...RESULTING IN MVFR AND IFR CONDITIONS IN
ADDITION TO WIDESPREAD RAIN SHOWERS...BEFORE THE FRONT PASSES EAST
FRIDAY NIGHT INTO SATURDAY MORNING. MAY SEE A BRIEF IMPROVEMENT TO
VFR ON SATURDAY AS HIGH PRESSURE BUILDS IN FROM THE
NORTH...HOWEVER IFR WILL RETURN SATURDAY NIGHT AS ANOTHER SYSTEM
APPROACHES FROM THE SOUTHWEST...BRINGING FREEZING RAIN...SNOW AND
SLEET TO THE AREA SUNDAY. AN ARCTIC COLD FRONT WILL MOVE THROUGH
ON MONDAY...BRINGING A SLOW IMPROVEMENT TO VFR FOR TUESDAY.
HIGH PRESSURE IS EXPECTED TO PROVIDE FAIR WEATHER WITH VFR
CONDITIONS FROM TUESDAY THROUGH THURSDAY.
&&
.CLIMATE...
WARM TEMPERATURES THE NEXT COUPLE DAYS WILL APPROACH RECORDS AT THE
CLIMATE SITES. BELOW ARE THE CURRENT RECORDS.
DECEMBER 5 CURRENT RECORD HIGH TEMPERATURES (YEAR)
ROA76(2001)
LYH76(2001)
DAN 75(1982)
BCB70(2001)
BLF71(2001)
LWB68(2001)
DECEMBER 5 CURRENT RECORD HIGH MINIMUM TEMPERATURES (YEAR)
ROA58(1982)
LYH60(1982)
DAN57(1982)
BCB52(1982)
BLF55(1994)
LWB53(1994)
DECEMBER 6 CURRENT RECORD HIGH MINIMUM TEMPERATURES (YEAR)
ROA52(2011)
LYH52(2011)
DAN60(2011)
BCB51(2011)
BLF56(2011)
LWB 52 (1998)
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...JH/KM
NEAR TERM...AMS/KK
SHORT TERM...JH
LONG TERM...RAB
AVIATION...AMS/KK
CLIMATE...CF
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
901 PM CST SAT DEC 7 2013
.UPDATE...
TEMPERATURES THIS EVENING HAVE RADIATED OUT QUICKLY...REACHING
NEAR THE EXPECTED LOWS ALREADY IN A FEW SPOTS. HOWEVER...AN
APPROACHING MID DECK OF CLOUDS ASSOCIATED WITH THE WARM ADVECTION
FROM THE SYSTEM TO OUR SOUTHWEST WILL PUT A HALT TO THAT TEMP
DROP ONCE THEY ARRIVE.
WITH RESPECT TO SUNDAY/S SNOW...THE NEW NAM IS NOT BRINGING ANY
SURPRISES. IF ANYTHING...IT LOOKS LIKE IT/S GENERATING A TAD MORE
PRECIP...ON THE ORDER OF ABOUT 1/2 INCH MORE OF SNOW. THE SURFACE
LOW TRACK IS VERY SIMILAR TO THE PREVIOUS RUN AND LOOKS A BIT
DEEPER/BETTER ORGANIZED. THE PREVIOUS DISCUSSION BELOW ABOUT THE
EVOLUTION OF THE LOW...WHERE THE HEAVIEST SNOW WILL FALL AND WHEN
IS STILL VERY MUCH VALID. THE EASTERN AREAS WILL SEE THE MOST DUE
TO THE LAKE EFFECT CONTRIBUTION.
WITH ONLY ONE NEW MODEL IN AT THIS TIME AND GIVEN IT/S LACK OF
SURPRISES...NO CHANGES TO THE LATER PERIODS.
&&
.AVIATION/06Z TAFS/...
THE MAIN AVIATION CONCERN DURING THIS PERIOD WILL BE THE SNOW AND
LIKELY REDUCTION TO IFR CONDITIONS BY SUNDAY AFTERNOON. THE MAIN
AREA OF SNOW WILL PUSH IN DURING THE LATE MORNING OR EARLY
AFTERNOON ON SUNDAY AS LOW PRESSURE APPROACHES. HOWEVER...SOME
LAKE EFFECT SNOW SHOWERS ARE LIKELY AHEAD OF THAT MAIN AREA FOR
KMKE/KENW/KUES. LIGHT AND VARIABLE WINDS WILL BECOME NORTHEAST TO
EAST LATE TONIGHT...ALLOWING THE LOWER LAKE EFFECT CLOUDS AND
LIGHT SNOW TO REACH THE 3 SOUTHEAST WI TAF SITES BETWEEN 12-15Z
SUN. THE LAKE EFFECT WILL COMBINE WITH THE MAIN AREA OF SNOW TO
BRING IFR CIGS/VSBYS BY AROUND 18Z AT ALL SITES. THE SNOW SHOULD
TAPER OFF AT KMSN BY AROUND 03-04Z MON AND AT THE 3 SOUTHEAST WI
TAFS SITES BY AROUND 06Z. ONCE THE SNOW ENDS...WESTERLY WINDS WILL
INCREASE TO AROUND 15 KNOTS.
&&
.PREV DISCUSSION... /ISSUED 330 PM CST SAT DEC 7 2013/
SHORT TERM...
TONIGHT...FORECAST CONFIDENCE IS HIGH
HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION TONIGHT. HIGH CLOUDS
WILL STREAM EAST NORTHEASTWARD INTO THE AREA LATER THIS EVENING AND
OVERNIGHT. TEMPERATURES MAY DROP QUICKLY THIS EVENING THROUGH THE
SINGLE DIGITS ABOVE ZERO...AS WINDS DECOUPLE WITH THE PASSING HIGH.
TEMPERATURES SHOULD THEN BECOME STEADY OR SLOWLY RISE LATER
TONIGHT...AS THE CLOUDS MOVE INTO THE AREA.
LAKE EFFECT SNOW SHOWER BAND SHOULD SET UP NORTH TO SOUTH ON THE
EASTERN SIDE OF LAKE MICHIGAN INTO THE SOUTHERN END OF THE LAKE THIS
EVENING. HRRR INDICATING THIS BAND SHOULD GRADUALLY SHIFT TO THE
WEST NORTHWEST LATER TONIGHT...POSSIBLY TRACKING INTO THE FAR
SOUTHEAST COUNTIES NEAR THE LAKE IN THE 09Z TO 12Z SUNDAY PERIOD.
ADDED POPS IN THIS AREA FOR THIS POSSIBILITY. MOST OF THE LAKE
EFFECT SNOW SHOWERS SHOULD HOLD OFF UNTIL AFTER 12Z SUNDAY.
SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH
THE MODELS ARE VERY SIMILAR WITH A WEAK BUT DEVELOPING LOW
PRESSURE THAT WILL APPROACH FROM THE PLAINS. THE SFC LOW WILL
BECOME CLOSED OFF AT 1015 MB NEAR OR EAST OF KMKE BY 06Z MON AND
CONTINUE TO DEEPEN AS IT MOVES THROUGH THE NORTHERN GREAT LAKES
AND INTO CANADA ON MON. A LARGE SCALE AND FAIRLY IMPRESSIVE LOW TO
MID LEVEL WARM ADVECTION PATTERN WITH WILL OVERSPREAD THE REGION
ON SUN WITH SNOW INTENSIFYING LATER IN THE AFTERNOON AND EVENING
WHEN THE SHORTWAVE TROUGH APPROACHES FROM THE SW.
A CONSENSUS OF THE MODELS ON QPF YIELDS QPF TOTALS OF 0.15-0.22.
THE DEPTH OF THE DENDRITE ZONE VARIES ON MODELS BUT HAS TRENDED
LESS DEEP FROM YESTERDAY. THEREFORE WILL GO WITH A MODEL CONSENSUS
OF SNOW RATIOS CLOSE TO 20 TO 1 VERSUS SOMETHING HIGHER. THIS
YIELDS 3 TO 4 INCHES WITH THE EXCEPTION OF 2-3 NEAR THE IL BORDER.
THERE HAS BEEN A SLIGHT NWD TREND WITH THE SHORTWAVE TROUGH AND
QPF...SO LESSER AMOUNTS NEAR THE IL BORDER IS REASONABLE. LAKE
ENHANCED SNOWS THEN NEED TO BE ADDED IN FOR OZAUKEE AND SHEBOYGAN
COUNTIES GIVEN THE 1000-850 MB SELY FLOW AND LAKE TO 850 MB TEMP
DIFFERENCES OF 14-17C. THE LAKE EFFECT SNOW CHARTS SUGGESTS ADDING
AT LEAST 3 INCHES SO FORECASTING 4-7 INCHES OF SNOW IN SHEBOYGAN
AND NRN OZAUKEE COUNTIES. IF GREATER LAKE ENHANCED SNOW IS EXPECTED
A WINTER STORM WARNING MAY BE NEEDED. A WINTER WX ADVISORY IS IN
EFFECT FOR ALL OF THE CWA FOR THIS SNOW EVENT.
BRISK WESTERLY WINDS AND COLD ADVECTION TO PREVAIL ON MON WITH
THE ARCTIC AIRMASS RETURNING AFTER HIGHS IN THE 20S ON SUN. WIND
GUSTS TO 25 MPH COMBINED WITH A POWDERY SNOW PACK SHOULD RESULT IN
AREAS OF BLOWING AND DRIFTING SNOW THAT WILL LIKELY CAUSE SOME
PROBLEMS THROUGHOUT THE DAY FOR TRAVEL. A SHORTWAVE SFC RIDGE WILL
MOVE ACROSS SRN WI MON NT WITH RADIATIONAL COOLING AND ARCTIC AIR
MAKING FOR ANOTHER VERY COLD NIGHT. SWLY WINDS WILL DEVELOP TOWARD
MORNING AS AN ALBERTA CLIPPER MOVES ACROSS THE NORTHERN GREAT
LAKES. WILL LIKELY ONLY SEE SCT-BKN CLOUD COVER FROM IT ON TUE
WITH THE SNOW REMAINING OVER NRN WI. DESPITE SWLY WINDS...HIGH
TEMPS TO ONLY REACH INTO THE TEENS. THE BRISK WINDS HOWEVER WILL
MAINTAIN VERY COLD WIND CHILLS FOR MON-TUE.
LONG TERM...WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE
MEDIUM.
A COUPLE WEAK CLIPPERS WILL BRING ONLY SMALL CHANCES OF LIGHT SNOW
OR FLURRIES FOR TUE NT INTO POSSIBLY WED AND AGAIN FOR THU. ARCTIC
AIR WILL REMAIN OVER THE AREA INTO THU NT. LOW PRESSURE WILL THEN
APPROACH FROM THE NRN PLAINS FOR LATE IN THE WEEK WITH WARM
ADVECTION BRINGING MODERATING TEMPS AND CHANCES OF LGT SNOW.
AVIATION/00Z TAFS/...
VFR CONDITIONS ARE EXPECTED TONIGHT ACROSS TAF SITES. WEST NORTHWEST
WINDS WILL GRADUALLY WEAKEN AND BECOME LIGHT TO CALM TONIGHT...WITH
HIGH CLOUDS MOVING INTO THE AREA BY LATER TONIGHT.
A LAKE EFFECT SNOW BAND WILL MOVE NORTHWARD TO KENOSHA AROUND 12Z
SUNDAY...AND MILWAUKEE/WAUKESHA BY 15Z SUNDAY. THE LIGHT SNOW
SHOWERS WITH THE BAND WILL LINGER FOR A 3 TO 5 HOUR PERIOD
THEREAFTER...WITH MVFR/IFR CEILINGS AND VISIBILITIES OF 2 TO 3
MILES. LIGHT ACCUMULATIONS OF UP TO 0.5 INCHES IS POSSIBLE. EAST
SOUTHEAST WINDS WILL INCREASE SUNDAY.
THE LIGHT TO MODERATE SNOW WITH THE LOW PRESSURE SYSTEM MOVING
NORTHEAST THROUGH THE REGION WILL REACH MADISON BY 15Z SUNDAY...AND
THE EASTERN SITES BY 18Z SUNDAY. THE SNOW WILL BECOME ALL LIGHT
BETWEEN 04Z AND 06Z MONDAY WEST TO EAST ACROSS TAF SITES...THEN
ENDING BETWEEN 09Z AND 12Z MONDAY SOUTHWEST TO NORTHEAST. WINDS WILL
VEER SOUTHWEST BY 06Z MONDAY...AND WEST BY 12Z MONDAY. WINDS WILL
BECOME GUSTY LATE SUNDAY NIGHT INTO MONDAY...WITH SOME BLOWING AND
DRIFTING SNOW.
CEILINGS/VISIBILITIES AT OR BELOW ALTERNATE MINIMUMS ARE
EXPECTED...WITH SOME 1/2 MILE VISIBILITIES POSSIBLE AT TIMES. THE
SNOW IS EXPECTED TO BE OF THE LIGHT AND FLUFFY VARIETY. SNOWFALL
RATES OF 1/4 TO 1/2 INCH PER HOUR ARE EXPECTED...WITH LOCALLY HIGHER
RATES POSSIBLE. TOTAL SNOW ACCUMULATIONS OF 3 TO 4 INCHES ARE
EXPECTED...HIGHEST AT MADISON/MILWAUKEE AND LOWEST AT KENOSHA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 6 AM CST MONDAY FOR
WIZ046-047-051-052-056>060-062>072.
LM...NONE.
&&
$$
UPDATE...DAVIS
TONIGHT/SUNDAY AND AVIATION/MARINE...WOOD
SUNDAY NIGHT THROUGH SATURDAY...GEHRING
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1243 AM EST SUN DEC 8 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS DIGGING FROM NRN
CA INTO NEVADA. AT THE SFC...WRLY WINDS PREVAILED THROUGH THE UPPER
GREAT LAKES TO THE NORTH OF THE ARCTIC RIDGE BUILDING FROM THE NRN
PLAINS AND UPPER MS VALLEY TO THE SRN LAKES. VERY COLD AIR REMAINED
WITH MID AFTERNOON READINGS ONLY CLIMBING INTO THE 5F TO 15F RANGE
THROUGH MID AFTERNOON. VIS SATELLITE INDICATED BACKING WINDS OVER
WRN LAKE SUPERIOR WITH THE LES BANDS BECOMING ALIGNED FROM SW-NE.
TONIGHT...EXPECT LES BANDS INTO THE KEWEENAW TO LIFT SLOWLY
NORTHWARD THIS EVENING. EVEN THOUGH THE HIGHER RES MODELS INDICATED
PERSISTENT LOW LEVEL CONV AND LES FROM AT LEAST CMX
NORTHWARD...CONFIDENCE IS LOWER GIVEN THE SATELLITE TRENDS. SO...THE
ONGOING HEADLINES WERE RETAINED FOR NOW BUT MAY NEED TO BE LIFTED
EARLIER THAN PREVIOUSLY FCST. IF A DOMINANT BAND CAN REDEVELOP AND
BRUSH THE WRN SHORE OF THE KEWEENAW...ADDITIONAL SNOWFALL AMOUNTS OF
3 TO 6 INCHES MAY BE POSSIBLE.
WITH A PERIOD OF FAVORABLE RADIATIONAL COOLING UNTIL LATE TONIGHT...
EXPECT MIN TEMPS NEAR LOWER END OF GUIDANCE WITH LOW TO MID TEENS
BELOW ZERO ACROSS MUCH OF THE WRN INTERIOR RANGING TO AROUND ZERO
OVER THE INTERIOR EAST. WINDS INTO THE 5 T0 10 MPH RANGE TIL LATE
TONIGHT CAUSED WIND CHILL READINGS TO DIP TO NEAR 25 BELOW...SO THE
WIND CHILL ADVISORY WAS RETAINED. THE POTENTIAL FOR INCREASING HIGH
CLOUDS LATE TONIGHT COULD CAUSE TEMPS TO LEVEL OFF A BIT OR RISE
SLIGHTLY TOWARD 12Z SUN.
SUN...ANY REMAINING LES IS EXPECTED TO LIFT TO THE NORTH OF KEWEENAW
AS WINDS BACK IN THE DEVELOPING WAA PATTERN. A BROAD AREA OF
280K-290K ISENTROPIC LIFT WILL BRING LIGHT SNOW FROM MN/WI INTO
UPPER MI DURING THE AFTERNOON. ALTHOUGH...THE VERY DRY LOW LEVELS IN
THE ARCTIC AIRMASS MAY DELAY THE ONSET OF THE PCPN...EXPECT AT LEAST
SOME LIGHT SNOW OVER THE SOUTH IN THE AFTERNOON THAT WILL SPREAD
THROUGH THE REST OF THE CWA BY MID TO LATE AFTERNOON. ACCUMULATIONS
BY 00Z/09 WILL BE RELATIVELY LIGHT...AROUND A HALF INCH OR
LESS...MAINLY OVER THE SOUTH.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013
DEEP TROUGHING ORIENTED FROM EASTERN CANADA ACROSS THE GREAT LAKES
AND WEST TO THE SOUTHWEST CONUS IS REINFORCED THROUGHOUT THE UPCOMING
WEEK. COLD AIRMASS MAY FINALLY MAY START TO RELAX BY NEXT WEEKEND AS
FLOW ALOFT BECOMES MORE ZONAL. FLOW PATTERN THIS WEEK REMAINS ACTIVE
ACROSS THE UPPER LAKES. A COUPLE OF SYSTEMS WILL CROSS THE AREA WITH
WIDESPREAD SYSTEM SNOWS. MOST SIGNIFICANT OF THESE WILL OCCUR SUNDAY
NIGHT AS SHORTWAVE/PV ANAMOLY CROSSING NEVADA/UTAH THIS AFTN/EVENING
HEADS OUT INTO CNTRL PLAINS SUNDAY AFTN THEN LIFTS ACROSS UPPER
GREAT LAKES SUNDAY NIGHT. SLIGHT WARM AIR ADVECTION...RELATIVE
TERM IN THIS AIRMASS...OCCURS OVER SOUTH CENTRAL AND EASTERN CWA
SUNDAY EVENING WITH PVA/DEEP LAYER FORCING THROUGH REST OF NIGHT.
CROSS-SECTIONS INDICATE VERY SHALLOW FGEN FORCING BLO H9...MAINLY
SOUTH AND EAST. MINIMAL SLANTWISE INSTABILITY/NEGATIVE EPV TO RESULT
IN HEAVIER BANDED SNOW THOUGH. ENHANCEMENT TO SYSTEM SNOW MAY OCCUR
NEAR BAY OF GREEN BAY AND LK MICHIGAN WITH ESE/E WINDS IN LOW-LEVELS
WITH TEMPS AT INVERSION TOP OF H85 AROUND -10C /LK MICHIGAN WATER
TEMPS ARE AROUND +5C/. TRICK IS HOW LONG FAVORABLE WIND DIRECTION
PERSISTS AND WHETHER THERE IS TOO MUCH SHEAR IN LAKE CONVECTIVE
LAYER TO OFFSET THIS. EXPECT GENERAL 2-4" OF SYNOPTIC SNOW WITH
MIXING RATIOS 1-2G/KG AND WITH 0.15-0.20 AVERAGED MODEL QPF USING
SLR/S 17-19:1. BASED ON SOUNDINGS...HIGHER SLR/S SEEMED TOUGHER TO
ACHIEVE AS BULK OF LIFT WILL BE OCCURRING AT TEMPS LESS THAN -20C.
SLR/S WILL PROBABLY BE EVEN LOWER HEADING FARTHER NORTH INTO UPR
MICHIGAN...SO SNOW AMOUNTS OF AN INCH MAYBE TWO ARE EXPECTED CLOSER
TO LK SUPERIOR SHORE. ISSUED WINTER WEATHER ADVY FOR THE SYSTEM
SNOW. BASED ON SREF PLUMES AND FCST POPS...VALID TIME OF ADVY FAR
SCNTRL WILL START LATE SUNDAY AFTN AND GO THROUGH DAYBREAK ON
MONDAY. ADVY FOR ZONES TO THE EAST WILL START AND END A FEW HOURS
LATER.
LOW PRESSURE SYSTEM LIFTS TO NORTHEAST OF LK SUPERIOR BY 18Z ON
MONDAY AND THIS WILL USHER IN ANOTHER RETURN TO THE COLD AND WINDY
WEATHER THAT OCCURRED LATE THIS LAST WEEK INTO TODAY. AND YES...LAKE
EFFECT SNOWS...HEAVY AT TIMES...WILL RAMP UP AGAIN IN THE AREAS
FAVORED BY WNW-W FLOW. SO...ONCE AGAIN...KEWEEENAW PENINSULA WILL BE
IN LINE FOR HEAVY LK EFFECT SNOWS. SOUNDINGS IN WAKE OF THE LOW
PRESSURE INDICATE MOIST/UNSTABLE PROFILE TO H7 WITH SHARP CONVERGENCE
DEVELOPING ACROSS KEWEENAW BY MID MORNING MONDAY AND CONTINUING
THROUGH AT LEAST LATE EVENING ON MONDAY NIGHT. SIMILAR TO
THURSDAY...IF WESTERLY FLOW CAN PERSIST IN ONE AREA...LEADING TO
STRONG CONVERGENCE...FOOT PLUS AMOUNTS WILL BE POSSIBLE ACROSS CNTRL
HOUGHTON COUNTY... AFFECTING PAINESDALE...ATLANTIC MINE...HOUGHTON
AND HANCOCK AND POSSIBLY AS FAR NORTH AS CALUMET AND MOHAWK. LAKE
EFFECT HEADLINES ARE RUNNING THEIR COURSE CURRENTLY...SO DID NOT
WANT TO PUT UP ANOTHER LK EFFECT SNOW WATCH AT THIS TIME. WILL LET
MID SHIFT ASSESS THIS POTENTIAL. MAIN ISSUE AWAY FM THE INCREASING
LK EFFECT BY MONDAY AFTN WILL BE ANOTHER BLAST OF COLD TEMPS AND
LOWERING WIND CHILL READINGS.
DOES APPEAR THAT AS STRONGER SHORTWAVE/PRETTY DECENT AREA OF H7-H5
Q-VECTOR CONVERGENCE ARRIVES LATER MONDAY NIGHT...BLYR WINDS BACK SW
ENOUGH TO DISRUPT HEAVIER SNOW ON THE KEWEENAW. THIS MAY PROVIDE A
GOOD BREAK POINT FOR WHATEVER HEADLINE IS ISSUED FOR MONDAY AND
MONDAY EVENING...THOUGH THERE IS A CHANCE THE HEAVIER SNOW BANDS
WILL JUST MAKE INTO KEWEENAW COUNTY BEFORE STALLING OUT. TOUGH TO
SAY AT THIS POINT. SOUNDINGS ELSEHWERE INDICATE ENOUGH MOISTENING
AND LIFT TO INCREASE POPS FOR THE SYSTEM...ESPECIALLY NORTH HALF.
SNOW AMOUNTS FM THE SYSTEM WILL BE ON THE LGT SIDE...LESS THAN AN
INCH MAINLY. OTHER IMPACT FM THE SHORTWAVE WILL BE FOR TEMPS TO TRY
TO RISE SOME LATER MONDAY NIGHT AS THE WINDS INCREASE. THIS MAKES
FOR TRICKY WIND CHILL FORECAST. CURRENT FCST FOR WINDS AND TEMPS
DOES SUGGEST THAT WESTERN HALF OF CWA MAY SEE WIND CHILL CRITERIA
BE MET AT TIMES ON MONDAY NIGHT INTO TUESDAY MORNING. LAST IMPACT
FROM THE SYSTEM WILL BE TO PUSH STRONGER SFC TROUGH SOUTH ACROSS LK
SUPERIOR RESULTING IN MORE OF A NW WIND IN BLYR FOR TUESDAY/TUESDAY
NIGHT. USED LK EFFECT CLIMATOLOGY POPS TO BRING HIGHER POPS TO AREAS
FAVORED BY WNW FLOW SUCH AS ONTONAGON COUTNY AND ALSO IN THE EASTERN
CWA...MAINLY EAST OF MUNISING AND TO THE NORTH OF NEWBERRY.
IN WAKE OF THE TROUGH PASSAGE...COLDEST AIR OF WEEK POURS ACROSS
WITH H85 TEMPS DOWN TO AROUND -25C TUESDAY NIGHT INTO WEDNESDAY.
MAY HAVE MORE WIND CHILL ISSUES TUESDAY NIGHT INTO WEDNESDAY AS
INLAND TEMPS FALL BLO ZERO AND WINDS STAY UP BEHIND THE TROUGH.
COLDEST DAY OF THE WEEK FOR WEDNESDAY WITH MAX TEMPS OVER INLAND
WEST POSSIBLY STAYING AT OR BLO ZERO THE ENTIRE DAY. COLDEST NIGHT
OF THE WEEK LIKELY ON WEDNESDAY NIGHT. AS WINDS GO CALM MAY SEE MINS
LESS THAN 20 BLO ZERO.
SLIGHT WARMING TREND FOR LATE THIS WEEK...BUT STILL QUITE A BIT BLO
NORMAL FOR DAYTIME HIGHS. WEST/SOUTHWEST FLOW LK EFFECT STAYS IN
PLACE ON KEWEENAW THURSDAY BUT THEN SHOULD REORIENT TO MORE NNW-N
FLOW AREAS ON FRIDAY AS ANOTHER SFC TROUGH SWINGS ACROSS. MAY SEE
SOME SYSTEM SNOW THURSDAY NIGHT INTO FRIDAY AHEAD OF THAT TROUGH BUT
THERE ARE SOME TIMING ISSUES THERE STILL...SO WILL JUST HAVE LOW
CHANCE POPS FOR NOW. DID BUMP UP THE CONSENSUS POPS FOR THE LK
EFFECT AREAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1239 AM EST SUN DEC 8 2013
WITH A DRY ARCTIC AIR MASS OVER THE AREA...AN OFFSHORE WIND
DIRECTION AT KSAW WILL RESULT IN VFR CONDITIONS THRU THE MORNING
HRS. AT KIWD...WINDS HAVE VEERED JUST ENOUGH OFF THE DECK TO BRING
LAKE STRATOCU (MVFR CIGS) INTO THE AREA. AS WINDS BACK AGAIN OVER
THE NEXT FEW HRS...STRATOCU WILL CLEAR OUT WITH VFR CONDITIONS THEN
CONTINUING THRU THE MORNING. AT KCMX...LAKE EFFECT SNOW WILL CONTINUE
THRU THE EARLY MORNING AS WINDS WILL HAVE ENOUGH OF AN ONSHORE
COMPONENT. EXPECT CONDITIONS TO VARY GENERALLY BTWN IFR AND MVFR THRU
THE NIGHT THOUGH BRIEF LIFR POSSIBLE OVER THE NEXT COUPLE OF HRS.
WITH LOSS OF ONSHORE WIND COMPONENT TOWARD DAYBREAK AS WINDS
BACK...CONDITIONS WILL IMPROVE TO VFR. IN THE AFTN...NEXT DISTURBANCE
WILL APPROACH FROM THE SW. EXPECT -SN/MVFR CONDITIONS TO SPREAD NE TO
ALL TERMINALS DURING THE AFTN...BEGINNING FIRST AT KIWD. WITH KSAW
CLOSER TO THE TRACK OF THE DISTURBANCE...IFR CONDITIONS ARE MORE
LIKELY TO DEVELOP THERE IN THE EVENING. &&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST SAT DEC 7 2013
EXPECT BRIEF BREAK IN STRONGER WINDS OVER LK SUPERIOR LATER THIS
EVENING THROUGH SUNDAY AS PRESSURE GRADIENT WEAKENS. A LOW PRESSURE
SYSTEM MOVING ACROSS THE AREA ON SUNDAY NIGHT...BUT WINDS WILL REMAIN
LESS THAN 25 KTS. AS THE LOW MOVES OUT OF THE AREA ON MONDAY...EXPECT
THE GRADIENT TO TIGHTEN AND WEST GALES TO DEVELOP THROUGH MONDAY
NIGHT. ANOTHER LOW PRESSURE SYSTEM WILL PASS THROUGH THE UPPER GREAT
LAKES TUESDAY INTO WEDNESDAY...POSSIBLY LEADING TO MORE GALES FROM
THE WEST TO NORTHWEST TUESDAY AFTERNOON THROUGH WEDNESDAY EVENING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR
MIZ002-004-009>011-084.
LAKE EFFECT SNOW ADVISORY UNTIL 5 AM EST EARLY THIS MORNING FOR
MIZ003.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ MONDAY FOR MIZ012-013.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ001.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 AM EST
MONDAY FOR MIZ007-014-085.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1157 PM EST SAT DEC 7 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS DIGGING FROM NRN
CA INTO NEVADA. AT THE SFC...WRLY WINDS PREVAILED THROUGH THE UPPER
GREAT LAKES TO THE NORTH OF THE ARCTIC RIDGE BUILDING FROM THE NRN
PLAINS AND UPPER MS VALLEY TO THE SRN LAKES. VERY COLD AIR REMAINED
WITH MID AFTERNOON READINGS ONLY CLIMBING INTO THE 5F TO 15F RANGE
THROUGH MID AFTERNOON. VIS SATELLITE INDICATED BACKING WINDS OVER
WRN LAKE SUPERIOR WITH THE LES BANDS BECOMING ALIGNED FROM SW-NE.
TONIGHT...EXPECT LES BANDS INTO THE KEWEENAW TO LIFT SLOWLY
NORTHWARD THIS EVENING. EVEN THOUGH THE HIGHER RES MODELS INDICATED
PERSISTENT LOW LEVEL CONV AND LES FROM AT LEAST CMX
NORTHWARD...CONFIDENCE IS LOWER GIVEN THE SATELLITE TRENDS. SO...THE
ONGOING HEADLINES WERE RETAINED FOR NOW BUT MAY NEED TO BE LIFTED
EARLIER THAN PREVIOUSLY FCST. IF A DOMINANT BAND CAN REDEVELOP AND
BRUSH THE WRN SHORE OF THE KEWEENAW...ADDITIONAL SNOWFALL AMOUNTS OF
3 TO 6 INCHES MAY BE POSSIBLE.
WITH A PERIOD OF FAVORABLE RADIATIONAL COOLING UNTIL LATE TONIGHT...
EXPECT MIN TEMPS NEAR LOWER END OF GUIDANCE WITH LOW TO MID TEENS
BELOW ZERO ACROSS MUCH OF THE WRN INTERIOR RANGING TO AROUND ZERO
OVER THE INTERIOR EAST. WINDS INTO THE 5 T0 10 MPH RANGE TIL LATE
TONIGHT CAUSED WIND CHILL READINGS TO DIP TO NEAR 25 BELOW...SO THE
WIND CHILL ADVISORY WAS RETAINED. THE POTENTIAL FOR INCREASING HIGH
CLOUDS LATE TONIGHT COULD CAUSE TEMPS TO LEVEL OFF A BIT OR RISE
SLIGHTLY TOWARD 12Z SUN.
SUN...ANY REMAINING LES IS EXPECTED TO LIFT TO THE NORTH OF KEWEENAW
AS WINDS BACK IN THE DEVELOPING WAA PATTERN. A BROAD AREA OF
280K-290K ISENTROPIC LIFT WILL BRING LIGHT SNOW FROM MN/WI INTO
UPPER MI DURING THE AFTERNOON. ALTHOUGH...THE VERY DRY LOW LEVELS IN
THE ARCTIC AIRMASS MAY DELAY THE ONSET OF THE PCPN...EXPECT AT LEAST
SOME LIGHT SNOW OVER THE SOUTH IN THE AFTERNOON THAT WILL SPREAD
THROUGH THE REST OF THE CWA BY MID TO LATE AFTERNOON. ACCUMULATIONS
BY 00Z/09 WILL BE RELATIVELY LIGHT...AROUND A HALF INCH OR
LESS...MAINLY OVER THE SOUTH.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013
DEEP TROUGHING ORIENTED FROM EASTERN CANADA ACROSS THE GREAT LAKES
AND WEST TO THE SOUTHWEST CONUS IS REINFORCED THROUGHOUT THE UPCOMING
WEEK. COLD AIRMASS MAY FINALLY MAY START TO RELAX BY NEXT WEEKEND AS
FLOW ALOFT BECOMES MORE ZONAL. FLOW PATTERN THIS WEEK REMAINS ACTIVE
ACROSS THE UPPER LAKES. A COUPLE OF SYSTEMS WILL CROSS THE AREA WITH
WIDESPREAD SYSTEM SNOWS. MOST SIGNIFICANT OF THESE WILL OCCUR SUNDAY
NIGHT AS SHORTWAVE/PV ANAMOLY CROSSING NEVADA/UTAH THIS AFTN/EVENING
HEADS OUT INTO CNTRL PLAINS SUNDAY AFTN THEN LIFTS ACROSS UPPER
GREAT LAKES SUNDAY NIGHT. SLIGHT WARM AIR ADVECTION...RELATIVE
TERM IN THIS AIRMASS...OCCURS OVER SOUTH CENTRAL AND EASTERN CWA
SUNDAY EVENING WITH PVA/DEEP LAYER FORCING THROUGH REST OF NIGHT.
CROSS-SECTIONS INDICATE VERY SHALLOW FGEN FORCING BLO H9...MAINLY
SOUTH AND EAST. MINIMAL SLANTWISE INSTABILITY/NEGATIVE EPV TO RESULT
IN HEAVIER BANDED SNOW THOUGH. ENHANCEMENT TO SYSTEM SNOW MAY OCCUR
NEAR BAY OF GREEN BAY AND LK MICHIGAN WITH ESE/E WINDS IN LOW-LEVELS
WITH TEMPS AT INVERSION TOP OF H85 AROUND -10C /LK MICHIGAN WATER
TEMPS ARE AROUND +5C/. TRICK IS HOW LONG FAVORABLE WIND DIRECTION
PERSISTS AND WHETHER THERE IS TOO MUCH SHEAR IN LAKE CONVECTIVE
LAYER TO OFFSET THIS. EXPECT GENERAL 2-4" OF SYNOPTIC SNOW WITH
MIXING RATIOS 1-2G/KG AND WITH 0.15-0.20 AVERAGED MODEL QPF USING
SLR/S 17-19:1. BASED ON SOUNDINGS...HIGHER SLR/S SEEMED TOUGHER TO
ACHIEVE AS BULK OF LIFT WILL BE OCCURRING AT TEMPS LESS THAN -20C.
SLR/S WILL PROBABLY BE EVEN LOWER HEADING FARTHER NORTH INTO UPR
MICHIGAN...SO SNOW AMOUNTS OF AN INCH MAYBE TWO ARE EXPECTED CLOSER
TO LK SUPERIOR SHORE. ISSUED WINTER WEATHER ADVY FOR THE SYSTEM
SNOW. BASED ON SREF PLUMES AND FCST POPS...VALID TIME OF ADVY FAR
SCNTRL WILL START LATE SUNDAY AFTN AND GO THROUGH DAYBREAK ON
MONDAY. ADVY FOR ZONES TO THE EAST WILL START AND END A FEW HOURS
LATER.
LOW PRESSURE SYSTEM LIFTS TO NORTHEAST OF LK SUPERIOR BY 18Z ON
MONDAY AND THIS WILL USHER IN ANOTHER RETURN TO THE COLD AND WINDY
WEATHER THAT OCCURRED LATE THIS LAST WEEK INTO TODAY. AND YES...LAKE
EFFECT SNOWS...HEAVY AT TIMES...WILL RAMP UP AGAIN IN THE AREAS
FAVORED BY WNW-W FLOW. SO...ONCE AGAIN...KEWEEENAW PENINSULA WILL BE
IN LINE FOR HEAVY LK EFFECT SNOWS. SOUNDINGS IN WAKE OF THE LOW
PRESSURE INDICATE MOIST/UNSTABLE PROFILE TO H7 WITH SHARP CONVERGENCE
DEVELOPING ACROSS KEWEENAW BY MID MORNING MONDAY AND CONTINUING
THROUGH AT LEAST LATE EVENING ON MONDAY NIGHT. SIMILAR TO
THURSDAY...IF WESTERLY FLOW CAN PERSIST IN ONE AREA...LEADING TO
STRONG CONVERGENCE...FOOT PLUS AMOUNTS WILL BE POSSIBLE ACROSS CNTRL
HOUGHTON COUNTY... AFFECTING PAINESDALE...ATLANTIC MINE...HOUGHTON
AND HANCOCK AND POSSIBLY AS FAR NORTH AS CALUMET AND MOHAWK. LAKE
EFFECT HEADLINES ARE RUNNING THEIR COURSE CURRENTLY...SO DID NOT
WANT TO PUT UP ANOTHER LK EFFECT SNOW WATCH AT THIS TIME. WILL LET
MID SHIFT ASSESS THIS POTENTIAL. MAIN ISSUE AWAY FM THE INCREASING
LK EFFECT BY MONDAY AFTN WILL BE ANOTHER BLAST OF COLD TEMPS AND
LOWERING WIND CHILL READINGS.
DOES APPEAR THAT AS STRONGER SHORTWAVE/PRETTY DECENT AREA OF H7-H5
Q-VECTOR CONVERGENCE ARRIVES LATER MONDAY NIGHT...BLYR WINDS BACK SW
ENOUGH TO DISRUPT HEAVIER SNOW ON THE KEWEENAW. THIS MAY PROVIDE A
GOOD BREAK POINT FOR WHATEVER HEADLINE IS ISSUED FOR MONDAY AND
MONDAY EVENING...THOUGH THERE IS A CHANCE THE HEAVIER SNOW BANDS
WILL JUST MAKE INTO KEWEENAW COUNTY BEFORE STALLING OUT. TOUGH TO
SAY AT THIS POINT. SOUNDINGS ELSEHWERE INDICATE ENOUGH MOISTENING
AND LIFT TO INCREASE POPS FOR THE SYSTEM...ESPECIALLY NORTH HALF.
SNOW AMOUNTS FM THE SYSTEM WILL BE ON THE LGT SIDE...LESS THAN AN
INCH MAINLY. OTHER IMPACT FM THE SHORTWAVE WILL BE FOR TEMPS TO TRY
TO RISE SOME LATER MONDAY NIGHT AS THE WINDS INCREASE. THIS MAKES
FOR TRICKY WIND CHILL FORECAST. CURRENT FCST FOR WINDS AND TEMPS
DOES SUGGEST THAT WESTERN HALF OF CWA MAY SEE WIND CHILL CRITERIA
BE MET AT TIMES ON MONDAY NIGHT INTO TUESDAY MORNING. LAST IMPACT
FROM THE SYSTEM WILL BE TO PUSH STRONGER SFC TROUGH SOUTH ACROSS LK
SUPERIOR RESULTING IN MORE OF A NW WIND IN BLYR FOR TUESDAY/TUESDAY
NIGHT. USED LK EFFECT CLIMATOLOGY POPS TO BRING HIGHER POPS TO AREAS
FAVORED BY WNW FLOW SUCH AS ONTONAGON COUTNY AND ALSO IN THE EASTERN
CWA...MAINLY EAST OF MUNISING AND TO THE NORTH OF NEWBERRY.
IN WAKE OF THE TROUGH PASSAGE...COLDEST AIR OF WEEK POURS ACROSS
WITH H85 TEMPS DOWN TO AROUND -25C TUESDAY NIGHT INTO WEDNESDAY.
MAY HAVE MORE WIND CHILL ISSUES TUESDAY NIGHT INTO WEDNESDAY AS
INLAND TEMPS FALL BLO ZERO AND WINDS STAY UP BEHIND THE TROUGH.
COLDEST DAY OF THE WEEK FOR WEDNESDAY WITH MAX TEMPS OVER INLAND
WEST POSSIBLY STAYING AT OR BLO ZERO THE ENTIRE DAY. COLDEST NIGHT
OF THE WEEK LIKELY ON WEDNESDAY NIGHT. AS WINDS GO CALM MAY SEE MINS
LESS THAN 20 BLO ZERO.
SLIGHT WARMING TREND FOR LATE THIS WEEK...BUT STILL QUITE A BIT BLO
NORMAL FOR DAYTIME HIGHS. WEST/SOUTHWEST FLOW LK EFFECT STAYS IN
PLACE ON KEWEENAW THURSDAY BUT THEN SHOULD REORIENT TO MORE NNW-N
FLOW AREAS ON FRIDAY AS ANOTHER SFC TROUGH SWINGS ACROSS. MAY SEE
SOME SYSTEM SNOW THURSDAY NIGHT INTO FRIDAY AHEAD OF THAT TROUGH BUT
THERE ARE SOME TIMING ISSUES THERE STILL...SO WILL JUST HAVE LOW
CHANCE POPS FOR NOW. DID BUMP UP THE CONSENSUS POPS FOR THE LK
EFFECT AREAS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1156 PM EST SAT DEC 7 2013
WITH A DRY ARCTIC AIR MASS OVER THE AREA...AN OFFSHORE WIND
DIRECTION AT KSAW WILL RESULT IN VFR CONDITIONS THRU THE MORNING
HRS. AT KIWD...WINDS HAVE VEERED JUST ENOUGH OFF THE DECK TO BRING
LAKE STRATOCU (MVFR CIGS) INTO THE AREA. AS WINDS BACK AGAIN OVER
THE NEXT FEW HRS...SRATOCU WILL CLEAR OUT WITH VFR CONDITIONS THEN
CONTINUING THRU THE MORNING. AT KCMX...LAKE EFFECT SNOW WILL
CONTINUE THRU THE EARLY MORNING AS WINDS WILL HAVE ENOUGH OF AN
ONSHORE COMPONENT. EXPECT CONDITIONS TO VARY GENERALLY BTWN IFR AND
MVFR THRU THE NIGHT THOUGH BRIEF LIFR POSSIBLE OVER THE NEXT COUPLE
OF HRS. WITH LOSS OF ONSHORE WIND COMPONENT TOWARD DAYBREAK AS WINDS
BACK...CONDITIONS WILL IMPROVE TO VFR. IN THE AFTN...NEXT
DISTURBANCE WILL APPROACH FROM THE SW. EXPECT -SN/MVFR CONDITIONS TO
SPREAD NE TO ALL TERMINALS DURING THE AFTN...BEGINNING FIRST AT
KIWD. WITH KSAW CLOSER TO THE TRACK OF THE DISTURBANCE...IFR
CONDITIONS ARE MORE LIKELY TO DEVELOP THERE IN THE EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST SAT DEC 7 2013
EXPECT BRIEF BREAK IN STRONGER WINDS OVER LK SUPERIOR LATER THIS
EVENING THROUGH SUNDAY AS PRESSURE GRADIENT WEAKENS. A LOW PRESSURE
SYSTEM MOVING ACROSS THE AREA ON SUNDAY NIGHT...BUT WINDS WILL REMAIN
LESS THAN 25 KTS. AS THE LOW MOVES OUT OF THE AREA ON MONDAY...EXPECT
THE GRADIENT TO TIGHTEN AND WEST GALES TO DEVELOP THROUGH MONDAY
NIGHT. ANOTHER LOW PRESSURE SYSTEM WILL PASS THROUGH THE UPPER GREAT
LAKES TUESDAY INTO WEDNESDAY...POSSIBLY LEADING TO MORE GALES FROM
THE WEST TO NORTHWEST TUESDAY AFTERNOON THROUGH WEDNESDAY EVENING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR MIZ002-
004-009>011-084.
LAKE EFFECT SNOW ADVISORY UNTIL 5 AM EST SUNDAY FOR MIZ003.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ SUNDAY TO 7 AM
EST /6 AM CST/ MONDAY FOR MIZ012-013.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST SUNDAY FOR MIZ001.
WINTER WEATHER ADVISORY FROM 7 PM SUNDAY TO 9 AM EST MONDAY FOR
MIZ007-014-085.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ264>267.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1148 PM CST Sat Dec 7 2013
.UPDATE:
Issued at 944 PM CST Sat Dec 7 2013
Several narrow snow bands have developed this evening across
southwest Missouri in an area of strong mid level frontogenetical
forcing and low/mid level warm advection ahead of a short wave
moving through the southern plains. Snow is reaching the ground in
and there are areas that have a dusting. The latest RAP and HRRR
runs increase the forcing and shift it northeastward parallelling
I-44 during the overnight hours and into the St. Louis metro area.
This seems reasonable based on observed trends. The only question
is the coverage and whether a wider more solitary band will evolve
or whether it will remain with several narrow bands. At this time
I have increased the pops within this corridor but only mentioned
scattered snow showers due to the uncertainty in the coverage
evolution. Some areas could certainly pick up a dusting to half
inch beneath them. If the coverage expands I will probably need to
boost pops into the likely category before the evening is over.
Glass
&&
.SHORT TERM: (Through Sunday Evening)
Issued at 301 PM CST Sat Dec 7 2013
Strong shortwave dipping into the base of the upper level trof
across the western CONUS will move across the Four Corners tonight
and emerge into the Plains on Sunday morning. Impressive warm
advection forecast to develop ahead of the shortwave with light qpf
noted on all model guidance to march northeast across the CWA from
late tonight through Sunday afternoon. Believe this is one of those
high PoP/low QPF events. Precipitation type is not clear cut...as
lack of ice crystal formation is noted on model soundings. I also
note that there is a steady stream of mid and high level clouds
streaming northeast from Texas. Wonder if the ice crystals from the
higher clouds will lead to a seeder/feeder situation, ultimately
allowing the precipitation to fall as more snow or snow grains
rather than freezing drizzle late tonight and tomorrow morning.
Tomorrow afternoon the best lift will be moving northeast and the
lower atmosphere will be warming so precipitation will likely turn
to areas of freezing drizzle that may continue into the evening.
Overall believe snowfall amounts will remain under an inch and any
freezing drizzle will only produce a light glaze. Will let the
evening and overnight shifts take a look at the 00Z model data to
determine the need, if any, for headlines on Sunday.
CVKING
.LONG TERM: (Sunday Night through Next Saturday)
Issued at 301 PM CST Sat Dec 7 2013
Cold front will progress southeast across the CWA late Sunday
night, reinforcing the cold for the beginning of the work week.
Next shortwave moves into the Plains Monday night an CWA will be in
a favorable area of synoptic lift provided by the right entrance
region of the jet streak to our northeast. This may ultimately
provide another chance of light snow south of Interstate 70. Have
kept slight chance PoPs at this time.
Extended forecast remains dry and cold with cold front passages
Wednesday and Friday.
CVKING
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1139 PM CST Sat Dec 7 2013
Have added mention of SN early in the period for STL/SUS/CPS for
approaching band of SN. This initial band is expected to be short
lived as it moves nwd thru the area. Also added light SN at
COU/UIN just before sunrise, but there is some uncertainty how
intense the SN will be. After a lull in precip, prev TAF forecast
still appears on track with another round mid to late morning and
gradually changing to FZDZ. Same uncertainties exist regarding
timing of change over and time when FZDZ will end. Guidance
continues to suggest that FZFG may be an issue as precip comes to
an end as low clouds settle into the region. For now, have visbys
at 5SM, but if trends continue, visbys may need to be lowered.
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
322 AM CST SUN DEC 8 2013
.DISCUSSION...
DURATION/COVERAGE/AMOUNTS OF SNOW THROUGH THIS EVENING ARE THE
PRIMARY FORECAST CHALLENGES.
SNOW DEVELOPED SATURDAY EVENING ACROSS MUCH OF SOUTHERN NEBRASKA
INCLUDING SOUTHEAST NEBRASKA...AND HAD SPREAD NORTH TO THE PLATTE
RIVER AND THE OMAHA METRO BY MIDNIGHT. THIS WAS SEVERAL HOURS
EARLIER THAN MODELS SHOWED 24 HOURS AGO WHEN THEY WERE PAINTING
SIGNIFICANT BOUNDARY LAYER DRY AIR THAT WOULD NOT BE OVERCOME UNTIL
AFTER MIDNIGHT FOR ALL BUT THE WESTERN CWA. ENHANCED LIFT IN RIGHT
ENTRANCE REGION OF UPPER JET OVERCAME THIS DRY AIR RATHER QUICKLY AS
RADAR RETURNS BLOSSOMED RAPIDLY SATURDAY EVENING IN SOUTH CENTRAL
THEN SOUTHEAST NEBRASKA. 00Z MODELS WERE NOT HANDLING THIS AREA OF
PRECIP WELL AT ALL...INSTEAD FOCUSING ON NORTHERN NEBRASKA BY 06Z.
HOWEVER MESOSCALE MODELS HRRR AND RAP WERE AT LEAST OFFERING BETTER
SOLUTIONS COMPARED TO CURRENT TRENDS.
UPPER TROUGH REMAINED WELL TO OUR WEST THIS MORNING...WITH BASE OF
TROUGH AXIS NEARING THE FOUR CORNERS REGION AT 08Z. A COUPLE OF
SHORTWAVES WERE NOTED IN WATER VAPOR IMAGERY...ONE ROUNDING BASE OF
TROUGH THAT WAS SHOWING ENHANCEMENT IN SOUTHERN ARIZONA...AND A
SECOND WAS SPINNING THROUGH CENTRAL COLORADO. THE FIRST SHORTWAVE
SUGGESTS A STRONG JET SEGMENT THAT WAS NOT HANDLED WELL BY
MODELS...AND EXTRAPOLATION PUTS THE LEFT EXIT REGION OF THAT JET
INTO NEBRASKA LATER THIS MORNING. THIS WILL AGAIN ENHANCE LIFT IN
OUR SOUTHERN/CENTRAL CWA. AND THE COLORADO VORT/SHORTWAVE IS PROGGED
TO WORK EAST INTO NEBRASKA THIS AFTERNOON BEFORE EXITING TO OUR EAST
BY 06Z. AHEAD OF BOTH SHORTWAVES WE WILL SEE CONTINUED ISENTROPIC
UPGLIDE THROUGH THE MORNING AND AFTERNOON BEFORE DOWNGLIDE BEGINS
FROM WEST TO EAST LATE IN THE DAY AND EVENING.
ISENTROPIC ANALYSIS ALONG THE 285K SURFACE INDICATES MIXING RATIOS
OF 2 G/KG WILL CONTINUE TO PUMP INTO OUR SOUTH AND CENTRAL CWA WHERE
LIFT IS EXPECTED TO BE STRONGEST. THIS TRANSLATES TO POTENTIALLY
ANOTHER 4 INCHES OF SNOW IN THOSE AREAS...PUTTING TOTALS IN THE 3 TO
6 INCH RANGE IN MOST OF THE SOUTHERN HALF OF THE CWA. IN THE
NORTHERN HALF AND ESPECIALLY NORTHEAST NEBRASKA...SNOW WAS SLOW TO
BEGIN BUT HAS ENHANCED MARKEDLY OVER THE PAST SEVERAL HOURS. REPORTS
OF AN INCH OR TWO HAVE COME IN FROM NEAR THE SOUTH DAKOTA
BORDER...WITH LESSER AMOUNTS TO THE SOUTH. LIFT IN THAT AREA DOES
NOT LOOK AS STRONG AS TO THE SOUTH...BUT AMOUNTS COULD STILL
APPROACH 3 INCHES BEFORE ENDING. ALREADY HAVE A WINTER WEATHER
ADVISORY GOING FOR MOST OF THE CWA. SOUTHERN AREAS SHOULD EASILY
VERIFY THIS...BUT NORTHERN AREAS COULD STRUGGLE TO REACH THE LOWER
END OF CRITERIA. HOWEVER WILL MAINTAIN ADVISORY FOR ALL CURRENT
AREAS AS SNOW IS JUST GETTING GOING IN OUR NORTH AND EXPECT SOME
ENHANCEMENT DURING THE MORNING.
SNOW SHOULD BE TAPERING IN OUR WEST BY MID AFTERNOON...THEN EASTERN
SECTIONS THIS EVENING. CLEARING SKIES AND FRESH SNOW COVER WILL
ALLOW TEMPERATURES TO DROP BELOW ZERO IN MUCH OF THE CWA. NORTHWEST
WINDS OF 10 TO 15 MPH SHOULD DEVELOP LATER TONIGHT AND MONDAY
MORNING...AND WITH SUB ZERO TEMPERATURES...WIND CHILLS WILL APPROACH
20 BELOW FOR THE START OF THE SCHOOL/WORK WEEK. WILL GO AHEAD AND
ISSUE A WIND CHILL ADVISORY FOR A GOOD PART OF OUR NORTHERN CWA
FOR LATE TONIGHT AND MONDAY MORNING.
ANOTHER SHORTWAVE WILL DIVE INTO THE GREAT LAKES MONDAY
NIGHT...CAUSING SURFACE FLOW TO BECOME SOUTHWESTERLY HERE MONDAY
AFTERNOON. BUT COLD START AND SNOW WILL KEEP HIGHS ONLY IN THE
TEENS. THEN A CLIPPER SYSTEM/SHORTWAVE IS FORECAST THROUGH NORTHEAST
NEBRASKA INTO IOWA TUESDAY NIGHT. AGAIN THIS WILL BRING WEST TO
SOUTHWEST WINDS TO OUR AREA MONDAY NIGHT AND TUESDAY...KEEPING LOWS
ABOVE ZERO AND PUSHING HIGHS INTO THE 20S. MODELS HAVE BEEN
PERSISTENT IN DROPPING A STRIPE OF LIGHT SNOW WITH THIS SYSTEM
TUESDAY NIGHT INTO WEDNESDAY MORNING...SO WILL INSERT SMALL CHANCES
FOR THIS IN OUR NORTHEAST CWA. MUCH COLDER AIR BEHIND THE CLIPPER
WILL KEEP HIGHS IN THE TEENS ON WEDNESDAY. THEN A GRADUAL WARMING
TREND LOOKS ON TRACK FOR THURSDAY INTO SATURDAY AS UPPER FLOW
TRANSITIONS FROM A NORTHWEST TO ZONAL SETUP. HAVE HIGHS CLOSE TO 30
EACH DAY.
DERGAN
&&
.AVIATION...06Z TAFS FOR KOMA...KLNK AND KOFK.
SNOW AT ALL TAF SITES...BUT ENDING BY 09/00Z AT KOFK...01-02Z AT
KLNK/KOMA. MVFR CLOUDS MAY EVENTUALLY BECOME IFR BY 10Z AS HEAVIER
LIFT MOVES INTO THE REGION...THEN BACK TO MVFR BY 16-18Z. EASTERLY
WINDS BECOME SOUTHEAST BUT LESS THAN 12 KNOTS...BUT THEN BECOME
LIGHTER AND VARIABLE AS A SURFACE TROUGH APPROACHES BY
19-21Z...THEN NORTHWEST BY 22-24Z. ACCUMULATIONS AT TAF SITES IN
THE 3 TO 4 INCHES.
DEWALD
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-
012-015>018-030>034-042>045-050>053-065>068-078-088>091.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR NEZ011-012-
015>018-030>034-042>045.
IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043-
055-056-069-079-080-090-091.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR IAZ043-055.
&&
$$
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1254 AM EST SUN DEC 8 2013
.SYNOPSIS...
A COLD FRONT WILL STALL SOUTH OF THE REGION INTO SUNDAY THEN LIFT
BACK NORTH THROUGH THE AREA SUNDAY NIGHT. ANOTHER COLD FRONT WILL
APPROACH FROM THE WEST MONDAY AND CROSS EARLY TUESDAY. COOL HIGH
PRESSURE WILL BUILD IN FROM THE WEST WEDNESDAY INTO FRIDAY. WEAK LOW
PRESSURE WILL DEVELOP NEAR THE COAST LATE IN THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1250 AM SUNDAY...PRECIPITATION IS LIMITED TO THE IMMEDIATE
COASTAL AREAS AND HAVE MADE CHANGES TO THE POPS TO REFLECT THE
CURRENT RADAR TRENDS WITH MINIMAL POPS INLAND. LATEST 3 KM HRRR
AND RAP INCREASES PRECIPITATION INLAND AFTER 12Z WITH INCREASING
ISENTROPIC LIFT MOVING INLAND. NO OTHER BIG CHANGES TO THE
FORECAST AS TEMPERATURES WILL REMAIN FAIRLY STEADY GIVEN THE
CLOUDINESS AND N/NE WINDS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM MONDAY/...
AS OF 215 PM SATURDAY...ISENT LIFT WILL GRAD LIFT N OF REGION
SUNDAY BUT STILL LOOKS LIKE DECENT CVRG OF RAIN/DRIZZLE ESPCLY
EARLY ALL AREAS AND ACROSS THE N LATER. DID NOT CHANGE POPS WHICH
HAVE LIKELY ALL AREAS EARLY...DIMINISHING TO CHC S AS BEST LIFTS
SHIFTS TO THE N. COOL NE FLOW WILL PERSIST INLAND WITH HIGHS IN
THE 40S...ALONG THE CST MAY SEE SOME LOW TO MID 50S AS LOW LVL
FLOW BECOMES A LITTLE MORE ONSHORE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AS OF 330 PM SAT...AN UPPER TROUGH WILL REMAIN CENTERED OVER THE
CENTRAL/WESTERN CONUS AS A STRONG RIDGE ALOFT REMAINS CENTERED
OVER FLORIDA AND THE SE CONUS...PLACING EASTERN NC IN SW FLOW
ALOFT THROUGH EARLY IN THE WEEK. WEAK SFC LOW/WARM FRONT WILL
DEVELOP SUN NIGHT AND MOVE NNE WITH RETURN SW FLOW TAKING OVER
WITH EASTERN NC AGAIN IN THE WARM SECTOR. RAIN CHANCES WILL END
DRASTICALLY SUN NIGHT...THOUGH FCST SNDGS INDICATE OVERCAST LOW
CLOUDS/MIST AND POSSIBLE PATCHY DRIZZLE SUN NIGHT WITH WARM FRONT
MOVING NORTHWARD. MAY SEE SOME SUNSHINE BREAK THROUGH ON MONDAY AS
SW WINDS BRING WARMING TEMPS INTO THE MID 60S NORTHWEST TO NEAR 70
SOUTH.
RAIN EXPECTED ONCE AGAIN MON NIGHT INTO TUE AS A FRONTAL BOUNDARY
PUSHES THROUGH FROM THE NORTH. PRECIP CHANCES INC FROM NORTH TO
SOUTH BEGINNING MON NIGHT. LOTS OF MOISTURE AVAILABLE WITH THIS
FRONTAL SYSTEM AS PLENTY OF GULF OF MEXICO MOISTURE IN SW FLOW
ALOFT. MAINTAINED LIKELY POPS DUE TO STRONG AGREEMENT AMONGST
OPER MODEL RUNS BETWEEN GFS/ECMWF AND ECMWF ENSEMBLE MEAN. FOR
HIGH TEMPS TUE...LOW CONFIDENCE AS TIMING OF THE FRONTAL BOUNDARY
THROUGH E NC WILL DICTATE WHETHER WARMER TEMPS NEAR 70 ARE
REALIZED OR TEMPS REMAIN IN THE 50S. GFS/NAM ARE SLOWER WITH THE
FRONT BRINGING IT THROUGH TUE AFTERNOON...WHILE FASTER ECMWF
PUSHES THE FRONT THROUGH BY TUE MORNING. IF SLOWER GFS/NAM SOLN
VERIFY COULD SEE SOME THUNDERSTORMS AS INSTABILITY WILL BE PRESENT
WITH SOLAR HEATING DURING THE DAY TUE. FOR NOW...HAVE COMPROMISED
AND HAVE COOLER 50S NORTH TO NEAR 70 ON THE CRYSTAL COAST AND KEPT
THUNDER OUT OF THE FCST. TEMPS SHOULD EXHIBIT A NON- DIURNAL
CURVE AS WARMEST READINGS REALIZED EARLY TUE. RAIN WILL QUICKLY
END BY TUES EVENING FROM NW TO SE AS THE FRONT SWEEPS OFFSHORE.
MUCH COOLER/DRIER AIR WILL FILTER IN BEHIND THE FRONT WED/THURS
WITH HIGHS IN THE UPPER 40S/LOW 50S WITH LOWS BELOW FREEZING MOST
AREAS INLAND. MODEST AGREEMENT THURS AFTERNOON WITH A WEAK LOW
DEVELOPING OFFSHORE OF SC/GA WHICH MAY WRAP AROUND SOME CLOUDS
INTO THE EASTERN HALF OF THE CWA...THUS MAINTAINED SLIGHT CHANCE
POPS WED NIGHT/THURS FOR THE COAST. NAEFS POPS AND ECM SOLN REMAIN
MAINLY DRY HOWEVER SO AM DISCOUNTING THE WETTER GFS SOLN. ANY
OFFSHORE LOW WILL SHIFT WELL AWAY FROM THE AREA LATE THUR WITH A
RETURN TO DRY CONDITIONS OVER THE AREA THROUGH FRI...WITH TEMPS
STILL 5-8 F BELOW NORMAL FOR MID DECEMBER.
07/12Z OPERATIONAL RUNS OF THE GFS/ECM INDICATE NEXT POSSIBLE STORM
SYSTEM MOVING UP OUT OF THE GOM LATE IN THE WEEK AS NEXT
SHORTWAVE DIGS THROUGH THE CENTRAL CONUS...SO HAVE INCLUDED CHANCE
POPS FOR LATE IN THE PERIOD INTO NEXT WEEKEND.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SHORT TERM /THROUGH 00Z MONDAY/...
AS OF 1250 PM SAT...PRECIPITATION IS NOW LIMITED TO COASTAL
SECTIONS WITH MVFR CEILINGS AT KEWN AND KOAJ WITH VFR AT BOTH KISO
AND KPGV CURRENTLY. WITH INCREASING ISENTROPIC LIFT AFTER
12Z...HAVE TRENDED CEILINGS DOWN TO IFR AT ALL TAF SITES THROUGH
THE DAY SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THU/...
AS OF 330 PM SAT..A WEAK LOW OFF THE COAST WILL PUSH NE THROUGH THE
AREA SUN NIGHT WITH SW FLOW TAKING OVER AND PRECIP CHANCES
DIMINISHING. HOWEVER...SOUNDINGS INDICATE PLENTY OF LOW LEVEL
MOISTURE REMAINING IN PLACE BRINGING POSSIBLE LIFR CIGS AND BR TO
THE TERMINALS...ALONG WITH SOME PATCHY DRIZZLE. LOW CLOUDS SHOULD
LIFT MON AS SW FLOW INCREASES. ANOTHER COLD FRONT CROSSES THE
TERMINALS FROM NW TO SE TUES WITH ANOTHER ROUND OF MVFR/IFR
CONDITIONS POSSIBLE IN LOWERED CEILINGS/VSBYS MON NIGHT THROUGH
TUE. HIGH PRESSURE BUILDS OVER THE REGION TUES NIGHT THROUGH MID
TO LATE WEEK WITH VFR RETURNING IN MOSTLY SUNNY SKIES.
&&
.MARINE...
SHORT TERM /THROUGH SUN/...
AS OF 1255 AM SUNDAY...GUSTY N/NNE WINDS CONTINUE OVER THE COASTAL
WATERS AND SOUNDS. WIND GUSTS CURRENTLY UP TO 30 KNOTS AT THE BUOY
13 MILES EAST OF OREGON INLET. SEAS THERE HAVE ALSO BUILT TO 9
FEET. MADE JUST MINOR TWEAKS TO THE CURRENT FORECAST AS THESE
TRENDS SHOULD CONTINUE OVERNIGHT AND THRU SUNDAY.
LONG TERM /SUNDAY NIGHT THROUGH THU/...
AS OF 330 PM SAT...WEAK SURFACE LOW MOVES NNE ALONG THE NC COAST
SUN NIGHT. SURFACE WINDS WILL BECOME W ONCE THE WEAK LOW LIFTS
NORTH OF THE WATERS SUN NIGHT. SW WINDS EXPECTED MON NIGHT AND
PEAK AROUND 15 KT BY EVENING. WINDS SHIFT N AND INCREASE 15-20 KT
DUE TO POST- FRONTAL CAA SURGE ASSOCIATED WITH STRONG HIGH
PRESSURE BUILDING OVER THE WATERS BEGINNING TUES AFTERNOON AND
LASTING INTO WED. SEAS BUILD 4-7 FT LATE TUES/TUES NIGHT.
REINFORCING COLD AIR SURGE POSSIBLE BY THUR KEEPING SCA CONDITIONS
A THREAT FOR MUCH OF THE COASTAL WATERS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR AMZ135.
SMALL CRAFT ADVISORY UNTIL 7 AM EST THIS MORNING FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR AMZ150-
152-154.
SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ156-
158.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF
LONG TERM...TL
AVIATION...CTC/TL
MARINE...CTC/TL/LEP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
132 AM CST SUN DEC 8 2013
.UPDATE...
ISSUED AT 132 AM CST SUN DEC 8 2013
LIGHT SNOW IS RAPIDLY DEVELOPING AND/OR SPREADING INTO LOCATIONS
ALONG/WEST OF THE MISSISSIPPI RIVER. IN FACT...EVEN HERE AT OUR
OFFICE BEGINNING TO SEE SOME VERY SMALL FLAKES FALL. HAVE UPDATED
THE FORECAST TO SPREAD PRECIPITATION CHANCES QUICKER INTO THE
AREA. APPEARS MUCH OF THE SNOW DURING THE EARLY MORNING HOURS WILL
BE LIGHT...LIKELY WITH VISIBILITIES ON THE ORDER OF 2 MILES. WSW
ALSO UPDATED TO RELAY THE SNOW STARTING UP QUICKER. RAP SEEMS TO
HAVE A GOOD HANDLE ON THE SITUATION THUS FAR.
AVIATION DISCUSSION UPDATED BELOW AS WELL TO ACCOUNT FOR THE
QUICKER START UP OF THE SNOW.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 206 PM CST SAT DEC 7 2013
FORECAST FOCUS IS ON SNOW POTENTIAL LATE TONIGHT THROUGH SUNDAY
WITH SEVERAL INCHES OF LIGHT FLUFF ANTICIPATED TO ACCUMULATE.
20Z SURFACE ANALYSIS SHOWS ARCTIC HIGH PRESSURE ENTRENCHED ACROSS
THE CENTRAL PART OF THE COUNTRY...WITH CHILLY TEMPS AND VERY
LITTLE IN THE WAY OF CLOUD COVER. BUT THIS IS EXPECTED TO CHANGE
AS A TROUGH OUT ACROSS THE INTERMOUNTAIN WEST MOVES QUICKLY INTO
OUR AREA BY SUNDAY AFTERNOON. WITH SUCH COLD AIR IN PLACE...AS THE
RELATIVELY WARMER AND MORE MOIST AIR MOVES NORTHWARD AHEAD THE
SYSTEM...SEVERAL HOURS OF LIGHT FLUFFY SNOW WILL OCCUR. SATELLITE
SHOWS HIGH CLOUDS ALREADY STREAMING INTO IA AHEAD OF THE SYSTEM...
WITH THICKENING CLOUDS THROUGH THE NIGHT TONIGHT.
MODELS HAVE BEEN INSISTING THAT THE FIRST WAA/ISENTROPIC UPGLIDE
SNOW WILL BEGIN ACROSS WESTERN IA AND SOUTHERN MN BY 12Z...BUT IT
WILL BE FIGHTING VERY DRY AIR INITIALLY. MODEL SOUNDINGS SHOW THE
DOWNWARD SATURATION WITH TIME. FEEL LIGHT ACCUMULATION WILL BE
POSSIBLE OVER SOUTHEAST MN AND NORTH CENTRAL IA ALREADY BEFORE
SUNRISE...WITH SNOW QUICKLY OVERSPREADING THE REMAINDER OF THE
AREA DURING THE MORNING. DRY AIR WILL BE THE MOST STUBBORN OVER
SOUTHERN WI WITH THE EASTERLY FLOW AROUND THE DEPARTING SURFACE
HIGH. WITH THIS SCENARIO AND IN AN EFFORT TO COORDINATE WITH
SURROUNDING OFFICES...HAVE STAGGERED THE START TIMES OF THE WINTER
WEATHER ADVISORY. SNOW RATIO SHOULD BE IN THE 17:1 TO 20:1
RANGE...SO IT WILL NOT TAKE MUCH LIQUID TO GENERATE A GOOD DEAL OF
SNOW. SNOW SHOULD BE TAPERING OFF FROM WEST TO EAST SUNDAY NIGHT.
PROBABLY COULD END THE ADVISORY EARLIER THAN 12Z MONDAY OVER
MN/IA...BUT KEPT IT GOING FOR SIMPLICITY. ONE OTHER CONCERN IS THE
WESTERLY WINDS THAT WILL KICK IN BEHIND THE SYSTEM. WITH THE LIGHT
FLUFFY NATURE OF THE NEW SNOW...IT WILL PROBABLY BE MOVED AROUND
WITH THE WIND. DO NOT FEEL IT WILL BE TRUE BLOWING SNOW HOWEVER...
BUT RATHER JUST SOME DRIFTING IN OPEN AREAS.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 206 PM CST SAT DEC 7 2013
HIGH PRESSURE BUILDS IN AGAIN ON MONDAY...BUT THE AREA WILL REMAIN
UNDER NORTHWEST FLOW ALOFT. SEVERAL PASSING WEAK SHORT WAVE
TROUGHS IN THE FLOW MAY RESULT IN SOME LIGHT SNOW OR FLURRIES FROM
TIME TO TIME. ONE SUCH DISTURBANCE COMES THROUGH MONDAY NIGHT INTO
TUESDAY ACROSS NORTHERN WI...AND ANOTHER COMES THROUGH TUESDAY
NIGHT...AND YET ANOTHER THURSDAY AND FRIDAY. IT WILL REMAIN QUITE
CHILLY THROUGH THE COMING WEEK AS WELL...WITH TEMPERATURES
REMAINING WELL BELOW NORMAL ALL THROUGH THE WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 132 AM CST SUN DEC 8 2013
LIGHT SNOW IS RAPIDLY DEVELOPING AND/OR SPREADING INTO THE TAF
SITES...LIKELY A CONSEQUENCE OF THE AIRMASS BEING SO COLD TO BEGIN
WITH. VISIBILITIES HAVE ALREADY DROPPED TO MVFR AT RST WITH SNOW
LIKELY TO BEGIN SOON AT LSE WITH FLURRIES BEING OBSERVED AT OUR
OFFICE. VISIBILITIES AT BOTH TAF SITES SHOULD DROP TO IFR WITHIN A
FEW HOURS AFTER THE SNOW STARTS...I.E. 09Z AT RST AND 12Z AT LSE.
CEILINGS ARE ALSO LOWERING QUICKLY UPSTREAM TO THE WEST WITH MVFR
CEILINGS LIKELY BY 12Z. FURTHER LOWERING IN CEILINGS AND
VISIBILITIES ARE EXPECTED THIS AFTERNOON AS SNOW PICKS UP
INTENSITY. THERE MAY EVEN BE A PERIOD OF LIFR VISIBILITIES DURING
THE AFTERNOON/EARLY EVENING HOURS. SNOW SHOULD THEN BEGIN
TAPERING OFF TOWARDS 06Z...HELPING VISIBILITIES IMPROVE. FLUFFY SNOW
ACCUMULATIONS OF NEAR 3 INCHES ARE EXPECTED TODAY WITH ANOTHER
INCH OR SO DURING THE EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 6 AM CST
MONDAY FOR WIZ017-029-032>034-041.
WINTER WEATHER ADVISORY FROM NOON TODAY TO 6 AM CST MONDAY FOR
WIZ042>044-053>055-061.
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR MNZ079-086-087-
094-095.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 6 AM CST
MONDAY FOR MNZ088-096.
IA...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR IAZ008-009-018-
019.
WINTER WEATHER ADVISORY FROM 6 AM THIS MORNING TO 6 AM CST
MONDAY FOR IAZ010-011-029-030.
&&
$$
UPDATE...AJ
SHORT TERM...MW
LONG TERM....MW
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
837 AM EST Sun Dec 8 2013
...Forecast Update...
Issued at 835 AM EST Sun Dec 8 2013
Ongoing winter weather event is panning out pretty much as expected
thus far across the region. The latest reports that continue to
filter in show up to 0.2 tenths of an inch of ice on trees and
elevated surfaces, with perhaps up to 0.25 inch in isolated
locations. The highest threat for icing up to 1/4 inch will be on a
line from Logan/Butler counties northeast to Clark/Madison/Garrard
counties. Thus far, reports indicate that side roads are a bit
icy in these areas, but main roads seem to be doing okay. Given the
short duration of the event (latest HRRR shows precip exiting most
locations by 19Z) and locations receiving the icing now will likely
get above freezing in the next couple of hours, will hold off on any
ice storm warning product for now. Certainly a high-end advisory
event in some areas, but impacts thus far continue to warrant
leaving the advisory as is. Will continue to monitor and upgrade
if impacts begin to increase over the next hour or so. Updates
already out.
.SHORT TERM (Now through Monday)...
Issued at 300 AM EST Sun Dec 8 2013
...A light wintry mix possible this morning...tending to change over
to just light rain by afternoon across south central Kentucky...
Upper air pattern shows a broad positively tilted trough across the
Rockies, with southwesterly flow extending from Oklahoma through New
England. Lift, associated with the right entrance region of a
departing jet, coupled with moisture overrunning a nearly stationary
boundary over Tennessee, will bring light mixed wintry precipitation
this morning over central Kentucky.
Forecast soundings show a warm layer around 850mb nosing northwards
across southern Kentucky, and eventually into the Bluegrass.
However, northeasterly winds will keep surface temperatures near
freezing along the Tennessee border, and in the mid to upper 20s
across central Kentucky.
Light mixed sleet and freezing rain will overspread southern
Kentucky during the predawn hours, and slowly move northeast towards
the Bluegrass and along the Ohio River around dawn or shortly after.
Towards Interstate 64, and across the Bluegrass, mixed precip may be
preceded by a period of light snow, with minor accumulations. By
noon, temperatures across our southern counties will slowly rise
above freezing. Any mixed precip should change over to rain or just
drizzle across the Bluegrass by mid to late afternoon. Along the
Ohio River, where snowcover remains, temperatures will struggle to
exceed freezing even by late afternoon.
Will continue with a winter weather advisory for light sleet and
icing across the central Commonwealth, and will likely allow it to
expire by early afternoon across our southern counties. We should
note that any icing or glaze will be light, as precipitation amounts
will likely stay under 2 tenths of an inch near the Ohio River,
ranging to maybe one half inch near the Lake Cumberland Region,
where temperatures will first rise above freezing. Despite light
precip amounts, any light glaze will adversely affect travel due to
antecedent cold pavement and ground.
Light precip will likely change over to just drizzle by
mid-afternoon as moisture become more shallow by evening. Continued
light rain may continue near Lake Cumberland, where a continued
fetch of moisture from the southwest may allow steadier
precipitation. Highs late this afternoon will range from the lower
40s near Lake Cumberland to the lower 30s across southern Indiana.
As this first wave passes, moisture will become more shallow, but
will continue saturated at low levels. So...expect cloudy skies this
evening and overnight, with maybe even some light fog and drizzle.
Temperatures won`t fall to much tonight, with lows not too far from
freezing south and east of the Ohio River.
Some partial clearing may arrive Monday afternoon, especially across
southern Indiana, with highs remaining in the 30s.
.LONG TERM (Monday Night through Saturday)...
Issued at 255 AM EST Sun Dec 8 2013
This period will begin with surface high pressure ridging across or
just north of the Ohio River. Aloft we will have a southwesterly
flow with an elongated vortmax stretching from southeast Ontario to
Oklahoma. Similar to yesterday`s 00Z model runs, today`s GFS/GEM/NAM
all have precip across our southeast early Tuesday as well as a
separate band of precip over southern Indiana, within the right
entrance region of a 180kt upper jet centered over Lake Erie. This
band, of what likely would be snow, is a little farther north than
what was forecast yesterday. The repetition in features, as well as
adding the new ECMWF into the mix, gives me enough of a signal to at
least put in a slight chance of snow across my north early Tuesday
and into the day. As for precip type across our southeast, that
mostly looks like snow from a quick look at soundings. We may warm
enough at the surface for a rain/snow mix. A quick look at forecast
totals for now indicates a sub-advisory event.
Another impulse moves through here Wednesday night, with a few of
the models hinting at low QPF just to our north. May get some
flurries out of this system across the north, but will leave
forecast dry for now.
High pressure on the back side of that system will shift east of our
area Friday, allowing for some southerly winds to try and start a
warmup for the weekend, at least closer to normal. With that warmup
will come another surge in moisture, bringing precip chances back
into the picture. Temperatures are at a range close enough to put in
a rain/snow mix Friday night through Saturday.
&&
.AVIATION (00Z TAF Update)...
Updated at 607 AM EST Sun Dec 8 2013
Light mixed wintry precipitation will continue through the morning
hours at SDF and LEX. For BWG, light freezing rain will switch to
just light rain around 17z. Ceilings will lower to low end MVFR or
to IFR within this precipitation
For BWG,
Light sleet and freezing rain will continue with IFR ceilings
through the mid to late morning hours, after which, it will switch
over to just light rain and diminish. Precipitation rates will stay
light enough so that visibilities will stay in the upper MVFR range.
Light drizzle with continued IFR ceilings are likely this afternoon.
Cloudy skies and possibly light drizzle will continue overnight with
IFR ceilings.
For LEX,
Light sleet, possibly mixed at first with light snow will be ongoing
right around the TAF issuance time. Ceilings will lower to IFR by
14z and continue this way through much of the day. This will change
into light freezing rain which will continue through the morning
hours, eventually changing to light rain or drizzle by mid
afternoon. IFR ceilings are likely this evening and overnight.
For SDF,
Light sleet and snow will continue through the morning
hours...possibly changing to light freezing rain or freezing drizzle
by early afternoon. Precipitation rates will stay light, so that
ground-based visibilities will stay high in the MVFR or even VFR
range today. IFR ceilings are expected this afternoon and tonight.
Northeast winds of 5 to 10 mph tonight will veer to easterly by
morning. Winds will become southerly at around 5 mph this evening.
In general, for the overnight period and through early Monday, IFR
ceilings and possibly some MVFR visibilities will continue even with
a general lack of precipitation.
Ceilings will rise into the MVFR category for all TAF sites by
Monday afternoon as winds become westerly at 5 to 10mph after noon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...WINTER WEATHER ADVISORY until 3 PM EST /2 PM CST/ this afternoon
FOR KYZ061>067-070>078-081-082.
WINTER WEATHER ADVISORY until 6 PM EST /5 PM CST/ this evening
FOR KYZ023>043-045>049-053>057.
IN...NONE.
&&
$$
Update.........KJD
Short Term.....JSD
Long Term......RJS
Aviation.......JSD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
642 AM EST SUN DEC 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 601 AM EST SUN DEC 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS MOVING THROUGH
UTAH EARLY THIS MORNING AND THIS FEATURE WILL BRING A SHOT OF
WIDESPREAD SYSTEM SNOW TO MUCH OF THE AREA TONIGHT INTO EARLY
MONDAY. STRONG SFC HIGH PRESSURE CENTERED JUST SOUTH OF OUR AREA
INTO WISCONSIN HAS RESULTED IN VERY COLD TEMPS (5 TO 15 BELOW ZERO)
EARLY THIS MORNING...ESPECIALLY ACROSS THE WESTERN INTERIOR OF UPPER
MICHIGAN. NOT MUCH WIND ACCOMPANYING THESE COLD TEMPS SO WENT AHEAD
AND CANCELLED THE WIND CHILL ADVISORY FOR THE WESTERN INTERIOR CWA.
WIND PARALLEL LES BANDS STILL IMPACTING THE KEWEENAW PENINSULA AND
ERN SHORELINE AREAS EARLY THIS MORNING IN CONVERGENT LOW-LVL
WESTERLY FLOW. WOULD NOT BE SURPRISED IF THESE AREAS ESPECIALLY THE
KEWEENAW RECEIVED AN ADDITIONAL 3 TO 5 INCHES OF LES OVERNIGHT.
TODAY...ANY REMAINING LES IS EXPECTED TO LIFT NORTH OF THE KEWEENAW
AND THE SHORELINES OF THE ERN COUNTIES AS WINDS BEGIN TO BACK SW IN
THE DEVELOPING WAA PATTERN. A BROAD AREA OF 275K-285K ISENTROPIC
LIFT AHEAD OF SHORTWAVE LIFTING OUT OF THE WRN CONUS TROF WILL
SPREAD LIGHT SNOW FROM MN/WI INTO UPPER MI DURING THE AFTERNOON.
ALTHOUGH...THE VERY DRY LOW LEVELS IN THE ARCTIC AIRMASS MAY DELAY
THE ONSET OF THE PCPN...EXPECT AT LEAST SOME LIGHT SNOW OVER THE
SOUTH BY EARLY AFTERNOON THAT WILL SPREAD THROUGH THE REST OF THE
CWA BY MID TO LATE AFTERNOON. ACCUMULATIONS BY 00Z WILL BE
RELATIVELY LIGHT...GENERALLY A HALF INCH OR LESS MOST AREAS WITH
MAYBE UP TO AN INCH SOUTH CENTRAL ALONG LAKE MI CLOSER TO BEST
ISENTROPIC LIFT AND Q-VECT CONV.
TONIGHT...AS THE SHORTWAVE CONTINUES TO LIFT TOWARD THE GREAT LAKES
FORCING IN LEFT EXIT REGION OF UPPER JET AND ASSOC 700-600 MB FGEN
RESPONSE ALONG WITH NOTED MINIMAL SLANTWISE INSTABILITY/NEGATIVE EPV
OFF CROSS SECTIONS COULD RESULT IN HEAVIER BANDED SNOW OVER SE
COUNTIES. ENHANCEMENT TO SYSTEM SNOW IS ALSO POSSIBLE NEAR BAY OF
GREEN BAY AND LK MICHIGAN WITH ESE SHIFTING SOUTH THROUGH THE NIGHT
/E WINDS IN LOW-LEVELS WITH 8H TEMPS AROUND -12C AND LK MICHIGAN
WATER TEMPS AROUND +5C. BIGGEST LIMITING FACTOR FOR LAKE ENHANCED
SNOW WILL BE SHIFTING WIND DIRECTION. EXPECT GENERAL 1-3" OF
SYNOPTIC SNOW WITH MIXING RATIOS 1-2G/KG AND WITH 0.15-0.20 AVERAGED
MODEL QPF USING SLR/S AROUND 18:1. BASED ON SOUNDINGS...HIGHER SLR/S
SEEM UNLIKELY DUE TO BEST LIFT OCCURING ABV DGZ. COULD SEE ANOTHER
1-2 OF LAKE ENHANCEMENT ON TOP OF SYSTEM SNOW PUSHING TOTAL SNOW
AMOUNTS INTO LOW END ADVISORY CATEGORY WITH 4-5 INCHES. AS A
RESULT...WILL CONTINUE THE WINTER WX ADVISORY FOR SE AND ERN
COUNTIES TONIGHT INTO EARLY MONDAY. FARTHER WEST GENERALLY EXPECT NO
MORE THAN 1-2 INCHES OF TOTAL SNOWFALL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 601 AM EST SUN DEC 8 2013
PERSISTENT DEEP TROUGHING OVER THE EASTERN HALF OF CANADA WILL BRING
REINFORCING SHOTS OF ARCTIC AIR THROUGH THE WEEK AHEAD. LAKE EFFECT
SNOW WILL ONCE AGAIN AFFECT LOCATIONS THAT SAW PLENTY THE LAST FEW
DAYS AS W TO WNW FLOW REMAINS FAIRLY CONTINUOUS. A WEAK CLIPPER
SYSTEM LOOKS TO BE THE ONLY REAL SHOT OF VERY LIGHT SYNOPTIC
SNOWFALL FOR THE ENTIRE CWA LATE MONDAY NIGHT INTO TUESDAY MORNING.
MONDAY...THE FIRST OF SEVERAL EMBEDDED SHORTWAVE TROUGHS WITHIN THE
DEEP EASTERN CANADIAN TROUGH WILL BE PUSHING THROUGH THE AREA MONDAY
MORNING. SEE THE SHORT TERM DISCUSSION FOR DETAILS REGARDING THE
MAIN PORTION OF THIS SYSTEM TONIGHT.
THE NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE WESTERN
CWA BEHIND A COLD FRONT AT THE START OF THE PERIOD. H8 TEMPS FALLING
TO -21 TO -23C BY THE AFTERNOON COMBINED WITH INVERSION HEIGHTS
RISING TO 7KFT AND UNIDIRECTIONAL WESTERLY WINDS SHOULD RESULT IN A
FAIRLY PERSISTENT DOMINATE LAKE EFFECT SNOW BAND AFFECTING NORTHERN
HOUGHTON AND SOUTHERN KEWEENAW COUNTIES. BLUSTERY WEST WINDS OF
20-30MPH WITH GUSTS OVER 35 MPH WILL MAKE CONDITIONS POOR...BUT IF
THE BAND REMAINS ANCHORED IN ONE AREA FOR AT LEAST SEVERAL
HOURS...WARNING CRITERIA SNOW WILL BE POSSIBLE. BECAUSE OF THIS
POTENTIAL ALONG WITH POSSIBLE NEAR BLIZZARD CONDITIONS AT
TIMES...HAVE ISSUED A LAKE EFFECT SNOW WATCH FOR NORTHERN HOUGHTON
AND KEWEENAW COUNTIES MONDAY MORNING INTO MONDAY EVENING. GUSTY
WINDS WILL LIKELY CONTINUE WELL INTO THE NIGHT...SO BLOWING SNOW
WILL REMAIN A PROBLEM. OVERALL...EXPECTATION IS THAT SOME LOCATIONS
COULD SEE IN EXCESS OF A FOOT OF SNOW MONDAY MORNING THROUGH
EVENING...WITH EVEN HIGHER AMOUNTS IF THE BAND REMAINS IN PLACE.
THROUGH...WITH A SLIGHT VEERING OF THE ABOVE-SFC WINDS AHEAD OF A
WEAK MID-LEVEL RIDGE LATE MONDAY AFTERNOON...THE BAND WILL LIKELY
WAVER SOMEWHAT.
MONDAY NIGHT AND TUESDAY...SUFFICIENT MODEL AGREEMENT AND
RUN-TO-RUN CONTINUITY THROUGH THIS PERIOD LEADS TO HIGHER
CONFIDENCE IN THE GOING FORECAST. DID NOT CHANGE MUCH FROM THE
PREVIOUS SHIFT OTHER THAN MAKE SOME MINOR ADJUSTMENTS TO POPS AND
QPF. THE SECOND OF MULTIPLE WAVES ON THE DEEP TROUGH IS PROGGED TO
CROSS UPPER MI LATE MONDAY NIGHT. LITTLE ADDITIONAL SYNOPTIC SUPPORT
WILL BE PRESENT WITH THIS TROUGH...SO ONLY A DUSTING OF SNOW IS
EXPECTED FOR MOST LOCATIONS IN THE CWA TUESDAY MORNING. THE APPROACH
OF THE TROUGH SHOULD BE ENOUGH TO LIMIT LES OFF ON THE KEWEENAW FOR
AT LEAST A SHORT TIME FRAME TUESDAY.
ALSO OF NOTE...LOW TEMPS MONDAY NIGHT HAVE A HIGH COMPONENT OF
VARIABILITY WITH THEM AS A WEAK SFC RIDGE CROSSES THE CWA WHILE HIGH
CLOUDS AHEAD OF TUESDAYS SYSTEM FILTER INTO THE AREA. WENT WITH
COLDEST TEMPS TO AROUND -10F INTERIOR CENTRAL AS THAT AREA LOOKS TO
HAVE THE LONGEST PERIOD OF UNINTERRUPTED COOLING.
TUESDAY NIGHT THROUGH THURSDAY...YET ANOTHER BLAST OF ARCTIC AIR
ARRIVES BEHIND TUESDAYS SYSTEM...THIS TIME WITH H8 TEMPS PUSHING
-25C BY WEDNESDAY AFTERNOON. COULD SEE SOME LOCATIONS WEST ALONG THE
WI BORDER FAIL TO GET ABOVE ZERO ON WEDNESDAY. VERY COLD TEMPS ARE
EXPECTED THROUGH THURSDAY...WITH WIND CHILL READINGS TO -30F
WEDNESDAY NIGHT INTERIOR WEST. WINDS MAY REMAIN LIGHT...SO WIND
CHILL HEADLINES MAY NOT BE NECESSARY.
LAKE EFFECT SNOW WILL ONCE AGAIN BE A CONCERN THROUGH THIS
STRETCH...ONLY THIS TIME WITH A LITTLE MORE OF A NORTHERLY COMPONENT
TO THE WIND. THIS WILL BRING THE POTENTIAL FOR HEAVY LES TUESDAY
NIGHT THROUGH THURSDAY NIGHT FOR THE KEWEENAW AND LOCATIONS EAST OF
MUNISING ALONG LAKE SUPERIOR. THE SETUP LOOKS FAIRLY SIMILAR TO THE
PAST SEVERAL DAYS...SO WOULD NOT BE SURPRISED TO SEE A DOMINATE BAND
AFFECTING BOTH OF THE AFOREMENTIONED LOCATIONS.
FRIDAY AND SATURDAY...MODEL GUIDANCE DIVERGES QUICKLY AT THIS
POINT...WITH THE ECMWF PULLING DOWN ONE MORE ARCTIC AIR MASS WHILE
THE GFS TRENDS TO A MORE ZONAL PATTERN. EITHER WAY...A BRIEF ROUND
OF LIGHT SYNOPTIC SNOW LOOKS POSSIBLE THURSDAY NIGHT INTO FRIDAY.
CONTINUED TO EMPLOY A CONSENSUS FORECAST AT THIS POINT. TEMPERATURES
WILL MODERATE SOMEWHAT BY NEXT WEEKEND...BUT STILL REMAIN 5 TO 10
DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 635 AM EST SUN DEC 8 2013
WITH A DRY ARCTIC AIR MASS OVER THE AREA...AN OFFSHORE WIND SSW
DIRECTION AT KSAW/KIWD WILL RESULT IN VFR CONDITIONS THRU THE MORNING
HRS. AT KCMX...LAKE EFFECT SNOW WILL DIMINISH/END IN THE NEXT FEW HOURS
AS BACKING WINDS PUSH LES OFFSHORE AND CONDITIONS IMPROVE TO VFR. IN
THE AFTN...NEXT DISTURBANCE WILL APPROACH FROM THE SW. EXPECT
-SN/MVFR CONDITIONS TO SPREAD NE TO ALL TERMINALS DURING THE
AFTN...BEGINNING FIRST AT KIWD. WITH KSAW CLOSER TO THE TRACK OF THE
DISTURBANCE...IFR CONDITIONS ARE MORE LIKELY TO DEVELOP THERE IN THE
EVENING. EXPECT IMPROVEMENT IN VSBY TO VFR LATE TONIGHT AT KIWD AS
BACK EDGE OF PCPN/SNOW SHIELD LIFTS NORTH.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 601 AM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES OF GALES. THE FIRST WILL PASS
SOUTHEAST OF UPPER MI MONDAY MORNING. BEHIND THIS TROUGH...WINDS
WILL VEER TO THE WEST AND INCREASE TO GALES TO 35 TO 40 KNOTS ACROSS
THE EAST HALF OF LAKE SUPERIOR MONDAY AFTERNOON AND EVENING. AFTER A
DECREASE TO 20 TO 30 KNOT SOUTHWEST WINDS TUESDAY MORNING...LOW
PRESSURE WILL TRACK EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND
PRODUCE WESTERLY WINDS OF UP TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON
AND EVENING. THE WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30
KNOTS FROM LATE TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE
EXTENDING FROM HIGH PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS
INTO THE AREA. CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE
POSSIBLE THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR
ACROSS THE LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE
SOUTHEASTWARD ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT
WINDS SHOULD REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS
SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM MONDAY MORNING THROUGH MONDAY
EVENING FOR MIZ001-003.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ MONDAY FOR MIZ012-013.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ001.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 AM EST
MONDAY FOR MIZ007-014-085.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ264>267.
GALE WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KLUBER
AVIATION...VOSS
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
602 AM EST SUN DEC 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 601 AM EST SUN DEC 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS MOVING THROUGH
UTAH EARLY THIS MORNING AND THIS FEATURE WILL BRING A SHOT OF
WIDESPREAD SYSTEM SNOW TO MUCH OF THE AREA TONIGHT INTO EARLY
MONDAY. STRONG SFC HIGH PRESSURE CENTERED JUST SOUTH OF OUR AREA
INTO WISCONSIN HAS RESULTED IN VERY COLD TEMPS (5 TO 15 BELOW ZERO)
EARLY THIS MORNING...ESPECIALLY ACROSS THE WESTERN INTERIOR OF UPPER
MICHIGAN. NOT MUCH WIND ACCOMPANYING THESE COLD TEMPS SO WENT AHEAD
AND CANCELLED THE WIND CHILL ADVISORY FOR THE WESTERN INTERIOR CWA.
WIND PARALLEL LES BANDS STILL IMPACTING THE KEWEENAW PENINSULA AND
ERN SHORELINE AREAS EARLY THIS MORNING IN CONVERGENT LOW-LVL
WESTERLY FLOW. WOULD NOT BE SURPRISED IF THESE AREAS ESPECIALLY THE
KEWEENAW RECEIVED AN ADDITIONAL 3 TO 5 INCHES OF LES OVERNIGHT.
TODAY...ANY REMAINING LES IS EXPECTED TO LIFT NORTH OF THE KEWEENAW
AND THE SHORELINES OF THE ERN COUNTIES AS WINDS BEGIN TO BACK SW IN
THE DEVELOPING WAA PATTERN. A BROAD AREA OF 275K-285K ISENTROPIC
LIFT AHEAD OF SHORTWAVE LIFTING OUT OF THE WRN CONUS TROF WILL
SPREAD LIGHT SNOW FROM MN/WI INTO UPPER MI DURING THE AFTERNOON.
ALTHOUGH...THE VERY DRY LOW LEVELS IN THE ARCTIC AIRMASS MAY DELAY
THE ONSET OF THE PCPN...EXPECT AT LEAST SOME LIGHT SNOW OVER THE
SOUTH BY EARLY AFTERNOON THAT WILL SPREAD THROUGH THE REST OF THE
CWA BY MID TO LATE AFTERNOON. ACCUMULATIONS BY 00Z WILL BE
RELATIVELY LIGHT...GENERALLY A HALF INCH OR LESS MOST AREAS WITH
MAYBE UP TO AN INCH SOUTH CENTRAL ALONG LAKE MI CLOSER TO BEST
ISENTROPIC LIFT AND Q-VECT CONV.
TONIGHT...AS THE SHORTWAVE CONTINUES TO LIFT TOWARD THE GREAT LAKES
FORCING IN LEFT EXIT REGION OF UPPER JET AND ASSOC 700-600 MB FGEN
RESPONSE ALONG WITH NOTED MINIMAL SLANTWISE INSTABILITY/NEGATIVE EPV
OFF CROSS SECTIONS COULD RESULT IN HEAVIER BANDED SNOW OVER SE
COUNTIES. ENHANCEMENT TO SYSTEM SNOW IS ALSO POSSIBLE NEAR BAY OF
GREEN BAY AND LK MICHIGAN WITH ESE SHIFTING SOUTH THROUGH THE NIGHT
/E WINDS IN LOW-LEVELS WITH 8H TEMPS AROUND -12C AND LK MICHIGAN
WATER TEMPS AROUND +5C. BIGGEST LIMITING FACTOR FOR LAKE ENHANCED
SNOW WILL BE SHIFTING WIND DIRECTION. EXPECT GENERAL 1-3" OF
SYNOPTIC SNOW WITH MIXING RATIOS 1-2G/KG AND WITH 0.15-0.20 AVERAGED
MODEL QPF USING SLR/S AROUND 18:1. BASED ON SOUNDINGS...HIGHER SLR/S
SEEM UNLIKELY DUE TO BEST LIFT OCCURING ABV DGZ. COULD SEE ANOTHER
1-2 OF LAKE ENHANCEMENT ON TOP OF SYSTEM SNOW PUSHING TOTAL SNOW
AMOUNTS INTO LOW END ADVISORY CATEGORY WITH 4-5 INCHES. AS A
RESULT...WILL CONTINUE THE WINTER WX ADVISORY FOR SE AND ERN
COUNTIES TONIGHT INTO EARLY MONDAY. FARTHER WEST GENERALLY EXPECT NO
MORE THAN 1-2 INCHES OF TOTAL SNOWFALL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 601 AM EST SUN DEC 8 2013
PERSISTENT DEEP TROUGHING OVER THE EASTERN HALF OF CANADA WILL BRING
REINFORCING SHOTS OF ARCTIC AIR THROUGH THE WEEK AHEAD. LAKE EFFECT
SNOW WILL ONCE AGAIN AFFECT LOCATIONS THAT SAW PLENTY THE LAST FEW
DAYS AS W TO WNW FLOW REMAINS FAIRLY CONTINUOUS. A WEAK CLIPPER
SYSTEM LOOKS TO BE THE ONLY REAL SHOT OF VERY LIGHT SYNOPTIC
SNOWFALL FOR THE ENTIRE CWA LATE MONDAY NIGHT INTO TUESDAY MORNING.
MONDAY...THE FIRST OF SEVERAL EMBEDDED SHORTWAVE TROUGHS WITHIN THE
DEEP EASTERN CANADIAN TROUGH WILL BE PUSHING THROUGH THE AREA MONDAY
MORNING. SEE THE SHORT TERM DISCUSSION FOR DETAILS REGARDING THE
MAIN PORTION OF THIS SYSTEM TONIGHT.
THE NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE WESTERN
CWA BEHIND A COLD FRONT AT THE START OF THE PERIOD. H8 TEMPS FALLING
TO -21 TO -23C BY THE AFTERNOON COMBINED WITH INVERSION HEIGHTS
RISING TO 7KFT AND UNIDIRECTIONAL WESTERLY WINDS SHOULD RESULT IN A
FAIRLY PERSISTENT DOMINATE LAKE EFFECT SNOW BAND AFFECTING NORTHERN
HOUGHTON AND SOUTHERN KEWEENAW COUNTIES. BLUSTERY WEST WINDS OF
20-30MPH WITH GUSTS OVER 35 MPH WILL MAKE CONDITIONS POOR...BUT IF
THE BAND REMAINS ANCHORED IN ONE AREA FOR AT LEAST SEVERAL
HOURS...WARNING CRITERIA SNOW WILL BE POSSIBLE. BECAUSE OF THIS
POTENTIAL ALONG WITH POSSIBLE NEAR BLIZZARD CONDITIONS AT
TIMES...HAVE ISSUED A LAKE EFFECT SNOW WATCH FOR NORTHERN HOUGHTON
AND KEWEENAW COUNTIES MONDAY MORNING INTO MONDAY EVENING. GUSTY
WINDS WILL LIKELY CONTINUE WELL INTO THE NIGHT...SO BLOWING SNOW
WILL REMAIN A PROBLEM. OVERALL...EXPECTATION IS THAT SOME LOCATIONS
COULD SEE IN EXCESS OF A FOOT OF SNOW MONDAY MORNING THROUGH
EVENING...WITH EVEN HIGHER AMOUNTS IF THE BAND REMAINS IN PLACE.
THROUGH...WITH A SLIGHT VEERING OF THE ABOVE-SFC WINDS AHEAD OF A
WEAK MID-LEVEL RIDGE LATE MONDAY AFTERNOON...THE BAND WILL LIKELY
WAVER SOMEWHAT.
MONDAY NIGHT AND TUESDAY...SUFFICIENT MODEL AGREEMENT AND
RUN-TO-RUN CONTINUITY THROUGH THIS PERIOD LEADS TO HIGHER
CONFIDENCE IN THE GOING FORECAST. DID NOT CHANGE MUCH FROM THE
PREVIOUS SHIFT OTHER THAN MAKE SOME MINOR ADJUSTMENTS TO POPS AND
QPF. THE SECOND OF MULTIPLE WAVES ON THE DEEP TROUGH IS PROGGED TO
CROSS UPPER MI LATE MONDAY NIGHT. LITTLE ADDITIONAL SYNOPTIC SUPPORT
WILL BE PRESENT WITH THIS TROUGH...SO ONLY A DUSTING OF SNOW IS
EXPECTED FOR MOST LOCATIONS IN THE CWA TUESDAY MORNING. THE APPROACH
OF THE TROUGH SHOULD BE ENOUGH TO LIMIT LES OFF ON THE KEWEENAW FOR
AT LEAST A SHORT TIME FRAME TUESDAY.
ALSO OF NOTE...LOW TEMPS MONDAY NIGHT HAVE A HIGH COMPONENT OF
VARIABILITY WITH THEM AS A WEAK SFC RIDGE CROSSES THE CWA WHILE HIGH
CLOUDS AHEAD OF TUESDAYS SYSTEM FILTER INTO THE AREA. WENT WITH
COLDEST TEMPS TO AROUND -10F INTERIOR CENTRAL AS THAT AREA LOOKS TO
HAVE THE LONGEST PERIOD OF UNINTERRUPTED COOLING.
TUESDAY NIGHT THROUGH THURSDAY...YET ANOTHER BLAST OF ARCTIC AIR
ARRIVES BEHIND TUESDAYS SYSTEM...THIS TIME WITH H8 TEMPS PUSHING
-25C BY WEDNESDAY AFTERNOON. COULD SEE SOME LOCATIONS WEST ALONG THE
WI BORDER FAIL TO GET ABOVE ZERO ON WEDNESDAY. VERY COLD TEMPS ARE
EXPECTED THROUGH THURSDAY...WITH WIND CHILL READINGS TO -30F
WEDNESDAY NIGHT INTERIOR WEST. WINDS MAY REMAIN LIGHT...SO WIND
CHILL HEADLINES MAY NOT BE NECESSARY.
LAKE EFFECT SNOW WILL ONCE AGAIN BE A CONCERN THROUGH THIS
STRETCH...ONLY THIS TIME WITH A LITTLE MORE OF A NORTHERLY COMPONENT
TO THE WIND. THIS WILL BRING THE POTENTIAL FOR HEAVY LES TUESDAY
NIGHT THROUGH THURSDAY NIGHT FOR THE KEWEENAW AND LOCATIONS EAST OF
MUNISING ALONG LAKE SUPERIOR. THE SETUP LOOKS FAIRLY SIMILAR TO THE
PAST SEVERAL DAYS...SO WOULD NOT BE SURPRISED TO SEE A DOMINATE BAND
AFFECTING BOTH OF THE AFOREMENTIONED LOCATIONS.
FRIDAY AND SATURDAY...MODEL GUIDANCE DIVERGES QUICKLY AT THIS
POINT...WITH THE ECMWF PULLING DOWN ONE MORE ARCTIC AIR MASS WHILE
THE GFS TRENDS TO A MORE ZONAL PATTERN. EITHER WAY...A BRIEF ROUND
OF LIGHT SYNOPTIC SNOW LOOKS POSSIBLE THURSDAY NIGHT INTO FRIDAY.
CONTINUED TO EMPLOY A CONSENSUS FORECAST AT THIS POINT. TEMPERATURES
WILL MODERATE SOMEWHAT BY NEXT WEEKEND...BUT STILL REMAIN 5 TO 10
DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1239 AM EST SUN DEC 8 2013
WITH A DRY ARCTIC AIR MASS OVER THE AREA...AN OFFSHORE WIND
DIRECTION AT KSAW WILL RESULT IN VFR CONDITIONS THRU THE MORNING
HRS. AT KIWD...WINDS HAVE VEERED JUST ENOUGH OFF THE DECK TO BRING
LAKE STRATOCU (MVFR CIGS) INTO THE AREA. AS WINDS BACK AGAIN OVER
THE NEXT FEW HRS...STRATOCU WILL CLEAR OUT WITH VFR CONDITIONS THEN
CONTINUING THRU THE MORNING. AT KCMX...LAKE EFFECT SNOW WILL CONTINUE
THRU THE EARLY MORNING AS WINDS WILL HAVE ENOUGH OF AN ONSHORE
COMPONENT. EXPECT CONDITIONS TO VARY GENERALLY BTWN IFR AND MVFR THRU
THE NIGHT THOUGH BRIEF LIFR POSSIBLE OVER THE NEXT COUPLE OF HRS.
WITH LOSS OF ONSHORE WIND COMPONENT TOWARD DAYBREAK AS WINDS
BACK...CONDITIONS WILL IMPROVE TO VFR. IN THE AFTN...NEXT DISTURBANCE
WILL APPROACH FROM THE SW. EXPECT -SN/MVFR CONDITIONS TO SPREAD NE TO
ALL TERMINALS DURING THE AFTN...BEGINNING FIRST AT KIWD. WITH KSAW
CLOSER TO THE TRACK OF THE DISTURBANCE...IFR CONDITIONS ARE MORE
LIKELY TO DEVELOP THERE IN THE EVENING.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 601 AM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES OF GALES. THE FIRST WILL PASS
SOUTHEAST OF UPPER MI MONDAY MORNING. BEHIND THIS TROUGH...WINDS
WILL VEER TO THE WEST AND INCREASE TO GALES TO 35 TO 40 KNOTS ACROSS
THE EAST HALF OF LAKE SUPERIOR MONDAY AFTERNOON AND EVENING. AFTER A
DECREASE TO 20 TO 30 KNOT SOUTHWEST WINDS TUESDAY MORNING...LOW
PRESSURE WILL TRACK EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND
PRODUCE WESTERLY WINDS OF UP TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON
AND EVENING. THE WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30
KNOTS FROM LATE TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE
EXTENDING FROM HIGH PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS
INTO THE AREA. CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE
POSSIBLE THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR
ACROSS THE LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE
SOUTHEASTWARD ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT
WINDS SHOULD REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS
SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM MONDAY MORNING THROUGH MONDAY
EVENING FOR MIZ001-003.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ MONDAY FOR MIZ012-013.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ001.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 AM EST
MONDAY FOR MIZ007-014-085.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ264>267.
GALE WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KLUBER
AVIATION...ROLFSON
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
526 AM EST SUN DEC 8 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS DIGGING FROM NRN
CA INTO NEVADA. AT THE SFC...WRLY WINDS PREVAILED THROUGH THE UPPER
GREAT LAKES TO THE NORTH OF THE ARCTIC RIDGE BUILDING FROM THE NRN
PLAINS AND UPPER MS VALLEY TO THE SRN LAKES. VERY COLD AIR REMAINED
WITH MID AFTERNOON READINGS ONLY CLIMBING INTO THE 5F TO 15F RANGE
THROUGH MID AFTERNOON. VIS SATELLITE INDICATED BACKING WINDS OVER
WRN LAKE SUPERIOR WITH THE LES BANDS BECOMING ALIGNED FROM SW-NE.
TONIGHT...EXPECT LES BANDS INTO THE KEWEENAW TO LIFT SLOWLY
NORTHWARD THIS EVENING. EVEN THOUGH THE HIGHER RES MODELS INDICATED
PERSISTENT LOW LEVEL CONV AND LES FROM AT LEAST CMX
NORTHWARD...CONFIDENCE IS LOWER GIVEN THE SATELLITE TRENDS. SO...THE
ONGOING HEADLINES WERE RETAINED FOR NOW BUT MAY NEED TO BE LIFTED
EARLIER THAN PREVIOUSLY FCST. IF A DOMINANT BAND CAN REDEVELOP AND
BRUSH THE WRN SHORE OF THE KEWEENAW...ADDITIONAL SNOWFALL AMOUNTS OF
3 TO 6 INCHES MAY BE POSSIBLE.
WITH A PERIOD OF FAVORABLE RADIATIONAL COOLING UNTIL LATE TONIGHT...
EXPECT MIN TEMPS NEAR LOWER END OF GUIDANCE WITH LOW TO MID TEENS
BELOW ZERO ACROSS MUCH OF THE WRN INTERIOR RANGING TO AROUND ZERO
OVER THE INTERIOR EAST. WINDS INTO THE 5 T0 10 MPH RANGE TIL LATE
TONIGHT CAUSED WIND CHILL READINGS TO DIP TO NEAR 25 BELOW...SO THE
WIND CHILL ADVISORY WAS RETAINED. THE POTENTIAL FOR INCREASING HIGH
CLOUDS LATE TONIGHT COULD CAUSE TEMPS TO LEVEL OFF A BIT OR RISE
SLIGHTLY TOWARD 12Z SUN.
SUN...ANY REMAINING LES IS EXPECTED TO LIFT TO THE NORTH OF KEWEENAW
AS WINDS BACK IN THE DEVELOPING WAA PATTERN. A BROAD AREA OF
280K-290K ISENTROPIC LIFT WILL BRING LIGHT SNOW FROM MN/WI INTO
UPPER MI DURING THE AFTERNOON. ALTHOUGH...THE VERY DRY LOW LEVELS IN
THE ARCTIC AIRMASS MAY DELAY THE ONSET OF THE PCPN...EXPECT AT LEAST
SOME LIGHT SNOW OVER THE SOUTH IN THE AFTERNOON THAT WILL SPREAD
THROUGH THE REST OF THE CWA BY MID TO LATE AFTERNOON. ACCUMULATIONS
BY 00Z/09 WILL BE RELATIVELY LIGHT...AROUND A HALF INCH OR
LESS...MAINLY OVER THE SOUTH.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 526 AM EST SUN DEC 8 2013
PERSISTENT DEEP TROUGHING OVER THE EASTERN HALF OF CANADA WILL BRING
REINFORCING SHOTS OF ARCTIC AIR THROUGH THE WEEK AHEAD. LAKE EFFECT
SNOW WILL ONCE AGAIN AFFECT LOCATIONS THAT SAW PLENTY THE LAST FEW
DAYS AS W TO WNW FLOW REMAINS FAIRLY CONTINUOUS. A WEAK CLIPPER
SYSTEM LOOKS TO BE THE ONLY REAL SHOT OF VERY LIGHT SYNOPTIC
SNOWFALL FOR THE ENTIRE CWA LATE MONDAY NIGHT INTO TUESDAY MORNING.
MONDAY...THE FIRST OF SEVERAL EMBEDDED SHORTWAVE TROUGHS WITHIN THE
DEEP EASTERN CANADIAN TROUGH WILL BE PUSHING THROUGH THE AREA MONDAY
MORNING. SEE THE SHORT TERM DISCUSSION FOR DETAILS REGARDING THE
MAIN PORTION OF THIS SYSTEM TONIGHT.
THE NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE WESTERN
CWA BEHIND A COLD FRONT AT THE START OF THE PERIOD. H8 TEMPS FALLING
TO -21 TO -23C BY THE AFTERNOON COMBINED WITH INVERSION HEIGHTS
RISING TO 7KFT AND UNIDIRECTIONAL WESTERLY WINDS SHOULD RESULT IN A
FAIRLY PERSISTENT DOMINATE LAKE EFFECT SNOW BAND AFFECTING NORTHERN
HOUGHTON AND SOUTHERN KEWEENAW COUNTIES. BLUSTERY WEST WINDS OF
20-30MPH WITH GUSTS OVER 35 MPH WILL MAKE CONDITIONS POOR...BUT IF
THE BAND REMAINS ANCHORED IN ONE AREA FOR AT LEAST SEVERAL
HOURS...WARNING CRITERIA SNOW WILL BE POSSIBLE. BECAUSE OF THIS
POTENTIAL ALONG WITH POSSIBLE NEAR BLIZZARD CONDITIONS AT
TIMES...HAVE ISSUED A LAKE EFFECT SNOW WATCH FOR NORTHERN HOUGHTON
AND KEWEENAW COUNTIES MONDAY MORNING INTO MONDAY EVENING. GUSTY
WINDS WILL LIKELY CONTINUE WELL INTO THE NIGHT...SO BLOWING SNOW
WILL REMAIN A PROBLEM. OVERALL...EXPECTATION IS THAT SOME LOCATIONS
COULD SEE IN EXCESS OF A FOOT OF SNOW MONDAY MORNING THROUGH
EVENING...WITH EVEN HIGHER AMOUNTS IF THE BAND REMAINS IN PLACE.
THROUGH...WITH A SLIGHT VEERING OF THE ABOVE-SFC WINDS AHEAD OF A
WEAK MID-LEVEL RIDGE LATE MONDAY AFTERNOON...THE BAND WILL LIKELY
WAVER SOMEWHAT.
MONDAY NIGHT AND TUESDAY...SUFFICIENT MODEL AGREEMENT AND
RUN-TO-RUN CONTINUITY THROUGH THIS PERIOD LEADS TO HIGHER
CONFIDENCE IN THE GOING FORECAST. DID NOT CHANGE MUCH FROM THE
PREVIOUS SHIFT OTHER THAN MAKE SOME MINOR ADJUSTMENTS TO POPS AND
QPF. THE SECOND OF MULTIPLE WAVES ON THE DEEP TROUGH IS PROGGED TO
CROSS UPPER MI LATE MONDAY NIGHT. LITTLE ADDITIONAL SYNOPTIC SUPPORT
WILL BE PRESENT WITH THIS TROUGH...SO ONLY A DUSTING OF SNOW IS
EXPECTED FOR MOST LOCATIONS IN THE CWA TUESDAY MORNING. THE APPROACH
OF THE TROUGH SHOULD BE ENOUGH TO LIMIT LES OFF ON THE KEWEENAW FOR
AT LEAST A SHORT TIME FRAME TUESDAY.
ALSO OF NOTE...LOW TEMPS MONDAY NIGHT HAVE A HIGH COMPONENT OF
VARIABILITY WITH THEM AS A WEAK SFC RIDGE CROSSES THE CWA WHILE HIGH
CLOUDS AHEAD OF TUESDAYS SYSTEM FILTER INTO THE AREA. WENT WITH
COLDEST TEMPS TO AROUND -10F INTERIOR CENTRAL AS THAT AREA LOOKS TO
HAVE THE LONGEST PERIOD OF UNINTERRUPTED COOLING.
TUESDAY NIGHT THROUGH THURSDAY...YET ANOTHER BLAST OF ARCTIC AIR
ARRIVES BEHIND TUESDAYS SYSTEM...THIS TIME WITH H8 TEMPS PUSHING
-25C BY WEDNESDAY AFTERNOON. COULD SEE SOME LOCATIONS WEST ALONG THE
WI BORDER FAIL TO GET ABOVE ZERO ON WEDNESDAY. VERY COLD TEMPS ARE
EXPECTED THROUGH THURSDAY...WITH WIND CHILL READINGS TO -30F
WEDNESDAY NIGHT INTERIOR WEST. WINDS MAY REMAIN LIGHT...SO WIND
CHILL HEADLINES MAY NOT BE NECESSARY.
LAKE EFFECT SNOW WILL ONCE AGAIN BE A CONCERN THROUGH THIS
STRETCH...ONLY THIS TIME WITH A LITTLE MORE OF A NORTHERLY COMPONENT
TO THE WIND. THIS WILL BRING THE POTENTIAL FOR HEAVY LES TUESDAY
NIGHT THROUGH THURSDAY NIGHT FOR THE KEWEENAW AND LOCATIONS EAST OF
MUNISING ALONG LAKE SUPERIOR. THE SETUP LOOKS FAIRLY SIMILAR TO THE
PAST SEVERAL DAYS...SO WOULD NOT BE SURPRISED TO SEE A DOMINATE BAND
AFFECTING BOTH OF THE AFOREMENTIONED LOCATIONS.
FRIDAY AND SATURDAY...MODEL GUIDANCE DIVERGES QUICKLY AT THIS
POINT...WITH THE ECMWF PULLING DOWN ONE MORE ARCTIC AIR MASS WHILE
THE GFS TRENDS TO A MORE ZONAL PATTERN. EITHER WAY...A BRIEF ROUND
OF LIGHT SYNOPTIC SNOW LOOKS POSSIBLE THURSDAY NIGHT INTO FRIDAY.
CONTINUED TO EMPLOY A CONSENSUS FORECAST AT THIS POINT. TEMPERATURES
WILL MODERATE SOMEWHAT BY NEXT WEEKEND...BUT STILL REMAIN 5 TO 10
DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1239 AM EST SUN DEC 8 2013
WITH A DRY ARCTIC AIR MASS OVER THE AREA...AN OFFSHORE WIND
DIRECTION AT KSAW WILL RESULT IN VFR CONDITIONS THRU THE MORNING
HRS. AT KIWD...WINDS HAVE VEERED JUST ENOUGH OFF THE DECK TO BRING
LAKE STRATOCU (MVFR CIGS) INTO THE AREA. AS WINDS BACK AGAIN OVER
THE NEXT FEW HRS...STRATOCU WILL CLEAR OUT WITH VFR CONDITIONS THEN
CONTINUING THRU THE MORNING. AT KCMX...LAKE EFFECT SNOW WILL CONTINUE
THRU THE EARLY MORNING AS WINDS WILL HAVE ENOUGH OF AN ONSHORE
COMPONENT. EXPECT CONDITIONS TO VARY GENERALLY BTWN IFR AND MVFR THRU
THE NIGHT THOUGH BRIEF LIFR POSSIBLE OVER THE NEXT COUPLE OF HRS.
WITH LOSS OF ONSHORE WIND COMPONENT TOWARD DAYBREAK AS WINDS
BACK...CONDITIONS WILL IMPROVE TO VFR. IN THE AFTN...NEXT DISTURBANCE
WILL APPROACH FROM THE SW. EXPECT -SN/MVFR CONDITIONS TO SPREAD NE TO
ALL TERMINALS DURING THE AFTN...BEGINNING FIRST AT KIWD. WITH KSAW
CLOSER TO THE TRACK OF THE DISTURBANCE...IFR CONDITIONS ARE MORE
LIKELY TO DEVELOP THERE IN THE EVENING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST SAT DEC 7 2013
EXPECT BRIEF BREAK IN STRONGER WINDS OVER LK SUPERIOR LATER THIS
EVENING THROUGH SUNDAY AS PRESSURE GRADIENT WEAKENS. A LOW PRESSURE
SYSTEM MOVING ACROSS THE AREA ON SUNDAY NIGHT...BUT WINDS WILL REMAIN
LESS THAN 25 KTS. AS THE LOW MOVES OUT OF THE AREA ON MONDAY...EXPECT
THE GRADIENT TO TIGHTEN AND WEST GALES TO DEVELOP THROUGH MONDAY
NIGHT. ANOTHER LOW PRESSURE SYSTEM WILL PASS THROUGH THE UPPER GREAT
LAKES TUESDAY INTO WEDNESDAY...POSSIBLY LEADING TO MORE GALES FROM
THE WEST TO NORTHWEST TUESDAY AFTERNOON THROUGH WEDNESDAY EVENING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM MONDAY MORNING THROUGH MONDAY
EVENING FOR MIZ001-003.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ MONDAY FOR MIZ012-013.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ001.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 AM EST
MONDAY FOR MIZ007-014-085.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ264>267.
GALE WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...ROLFSON
MARINE...JLA
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
854 AM CST SUN DEC 8 2013
.DISCUSSION...
HAVE UPDATED THE FORECAST...WITH THE BIGGEST CHANGE BEING THE
ADDITION OF PAWNEE AND RICHARDSON COUNTIES TO THE ADVISORY.
MODERATE SNOWFALL IS ONGOING THERE...AND THE POTENTIAL IS JUST AS
HIGH THERE FOR 2-3 INCHES OF SNOW AS MANY OTHER AREAS OF THE CWA.
ACTUALLY REDUCED POPS IN NORTHEAST NEB FOR A SHORT PERIOD THIS
LATE MORNING/EARLY AFTERNOON...WHERE THERE ARE LITTLE MORE THAN
FLURRIES NOW. ADJUSTED SNOW TOTALS DOWNWARD UP THERE...AND UPWARD
IN SOUTHEAST NEB. ALSO UPDATED TEMPERATURE AND DEWPOINT
TRENDS...AS TEMPS DID NOT FALL FAR OVERNIGHT AND HAVE BEEN STEADY
TO RISING.
MAYES
&&
.PREV DISCUSSION... /ISSUED 532 AM CST SUN DEC 8 2013/
AVIATION...12Z TAFS FOR KOFK...KOMA AND KLNK.
LIGHT SNOW WILL CONTINUE OVER THE TAF SITES THROUGH 20Z...WITH THE
HEAVIER INTENSITIES REMAINING OVER KLNK. IFR CONDITIONS ARE
EXPECTED PRIMARILY AT KLNK IN SNOW WITH MVFR TO VFR AT KOFK AND
KOMA. SNOW WILL TAPER OFF AND END FROM WEST TO EAST LATER THIS
AFTERNOON. TOTAL SNOWFALL ACCUMULATIONS OF 2 TO 4 INCHES ARE
POSSIBLE...WITH THE HEAVIER AMOUNTS AT KLNK AND KOMA. SKIES ARE
EXPECTED TO SCATTER OUT THIS EVENING AND EVENTUALLY CLEAR OUT
OVERNIGHT. A COLD FRONT WILL MOVE ACROSS THE TAF SITES BY EARLY
EVENING. THIS COULD PUSH NORTHWEST WINDS UP TO AROUND 10-12KTS
OVERNIGHT AND PRODUCE SOME DRIFTING OF SNOW OVERNIGHT.
KERN
PREV DISCUSSION... /ISSUED 322 AM CST SUN DEC 8 2013/
DISCUSSION...
DURATION/COVERAGE/AMOUNTS OF SNOW THROUGH THIS EVENING ARE THE
PRIMARY FORECAST CHALLENGES.
SNOW DEVELOPED SATURDAY EVENING ACROSS MUCH OF SOUTHERN NEBRASKA
INCLUDING SOUTHEAST NEBRASKA...AND HAD SPREAD NORTH TO THE PLATTE
RIVER AND THE OMAHA METRO BY MIDNIGHT. THIS WAS SEVERAL HOURS
EARLIER THAN MODELS SHOWED 24 HOURS AGO WHEN THEY WERE PAINTING
SIGNIFICANT BOUNDARY LAYER DRY AIR THAT WOULD NOT BE OVERCOME UNTIL
AFTER MIDNIGHT FOR ALL BUT THE WESTERN CWA. ENHANCED LIFT IN RIGHT
ENTRANCE REGION OF UPPER JET OVERCAME THIS DRY AIR RATHER QUICKLY AS
RADAR RETURNS BLOSSOMED RAPIDLY SATURDAY EVENING IN SOUTH CENTRAL
THEN SOUTHEAST NEBRASKA. 00Z MODELS WERE NOT HANDLING THIS AREA OF
PRECIP WELL AT ALL...INSTEAD FOCUSING ON NORTHERN NEBRASKA BY 06Z.
HOWEVER MESOSCALE MODELS HRRR AND RAP WERE AT LEAST OFFERING BETTER
SOLUTIONS COMPARED TO CURRENT TRENDS.
UPPER TROUGH REMAINED WELL TO OUR WEST THIS MORNING...WITH BASE OF
TROUGH AXIS NEARING THE FOUR CORNERS REGION AT 08Z. A COUPLE OF
SHORTWAVES WERE NOTED IN WATER VAPOR IMAGERY...ONE ROUNDING BASE OF
TROUGH THAT WAS SHOWING ENHANCEMENT IN SOUTHERN ARIZONA...AND A
SECOND WAS SPINNING THROUGH CENTRAL COLORADO. THE FIRST SHORTWAVE
SUGGESTS A STRONG JET SEGMENT THAT WAS NOT HANDLED WELL BY
MODELS...AND EXTRAPOLATION PUTS THE LEFT EXIT REGION OF THAT JET
INTO NEBRASKA LATER THIS MORNING. THIS WILL AGAIN ENHANCE LIFT IN
OUR SOUTHERN/CENTRAL CWA. AND THE COLORADO VORT/SHORTWAVE IS PROGGED
TO WORK EAST INTO NEBRASKA THIS AFTERNOON BEFORE EXITING TO OUR EAST
BY 06Z. AHEAD OF BOTH SHORTWAVES WE WILL SEE CONTINUED ISENTROPIC
UPGLIDE THROUGH THE MORNING AND AFTERNOON BEFORE DOWNGLIDE BEGINS
FROM WEST TO EAST LATE IN THE DAY AND EVENING.
ISENTROPIC ANALYSIS ALONG THE 285K SURFACE INDICATES MIXING RATIOS
OF 2 G/KG WILL CONTINUE TO PUMP INTO OUR SOUTH AND CENTRAL CWA WHERE
LIFT IS EXPECTED TO BE STRONGEST. THIS TRANSLATES TO POTENTIALLY
ANOTHER 4 INCHES OF SNOW IN THOSE AREAS...PUTTING TOTALS IN THE 3 TO
6 INCH RANGE IN MOST OF THE SOUTHERN HALF OF THE CWA. IN THE
NORTHERN HALF AND ESPECIALLY NORTHEAST NEBRASKA...SNOW WAS SLOW TO
BEGIN BUT HAS ENHANCED MARKEDLY OVER THE PAST SEVERAL HOURS. REPORTS
OF AN INCH OR TWO HAVE COME IN FROM NEAR THE SOUTH DAKOTA
BORDER...WITH LESSER AMOUNTS TO THE SOUTH. LIFT IN THAT AREA DOES
NOT LOOK AS STRONG AS TO THE SOUTH...BUT AMOUNTS COULD STILL
APPROACH 3 INCHES BEFORE ENDING. ALREADY HAVE A WINTER WEATHER
ADVISORY GOING FOR MOST OF THE CWA. SOUTHERN AREAS SHOULD EASILY
VERIFY THIS...BUT NORTHERN AREAS COULD STRUGGLE TO REACH THE LOWER
END OF CRITERIA. HOWEVER WILL MAINTAIN ADVISORY FOR ALL CURRENT
AREAS AS SNOW IS JUST GETTING GOING IN OUR NORTH AND EXPECT SOME
ENHANCEMENT DURING THE MORNING.
SNOW SHOULD BE TAPERING IN OUR WEST BY MID AFTERNOON...THEN EASTERN
SECTIONS THIS EVENING. CLEARING SKIES AND FRESH SNOW COVER WILL
ALLOW TEMPERATURES TO DROP BELOW ZERO IN MUCH OF THE CWA. NORTHWEST
WINDS OF 10 TO 15 MPH SHOULD DEVELOP LATER TONIGHT AND MONDAY
MORNING...AND WITH SUB ZERO TEMPERATURES...WIND CHILLS WILL APPROACH
20 BELOW FOR THE START OF THE SCHOOL/WORK WEEK. WILL GO AHEAD AND
ISSUE A WIND CHILL ADVISORY FOR A GOOD PART OF OUR NORTHERN CWA
FOR LATE TONIGHT AND MONDAY MORNING.
ANOTHER SHORTWAVE WILL DIVE INTO THE GREAT LAKES MONDAY
NIGHT...CAUSING SURFACE FLOW TO BECOME SOUTHWESTERLY HERE MONDAY
AFTERNOON. BUT COLD START AND SNOW WILL KEEP HIGHS ONLY IN THE
TEENS. THEN A CLIPPER SYSTEM/SHORTWAVE IS FORECAST THROUGH NORTHEAST
NEBRASKA INTO IOWA TUESDAY NIGHT. AGAIN THIS WILL BRING WEST TO
SOUTHWEST WINDS TO OUR AREA MONDAY NIGHT AND TUESDAY...KEEPING LOWS
ABOVE ZERO AND PUSHING HIGHS INTO THE 20S. MODELS HAVE BEEN
PERSISTENT IN DROPPING A STRIPE OF LIGHT SNOW WITH THIS SYSTEM
TUESDAY NIGHT INTO WEDNESDAY MORNING...SO WILL INSERT SMALL CHANCES
FOR THIS IN OUR NORTHEAST CWA. MUCH COLDER AIR BEHIND THE CLIPPER
WILL KEEP HIGHS IN THE TEENS ON WEDNESDAY. THEN A GRADUAL WARMING
TREND LOOKS ON TRACK FOR THURSDAY INTO SATURDAY AS UPPER FLOW
TRANSITIONS FROM A NORTHWEST TO ZONAL SETUP. HAVE HIGHS CLOSE TO 30
EACH DAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-
012-015>018-030>034-042>045-050>053-065>068-078-088>093.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR NEZ011-012-
015>018-030>034-042>045.
IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043-
055-056-069-079-080-090-091.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR IAZ043-055.
&&
$$
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
532 AM CST SUN DEC 8 2013
.AVIATION...12Z TAFS FOR KOFK...KOMA AND KLNK.
LIGHT SNOW WILL CONTINUE OVER THE TAF SITES THROUGH 20Z...WITH THE
HEAVIER INTENSITIES REMAINING OVER KLNK. IFR CONDITIONS ARE
EXPECTED PRIMARILY AT KLNK IN SNOW WITH MVFR TO VFR AT KOFK AND
KOMA. SNOW WILL TAPER OFF AND END FROM WEST TO EAST LATER THIS
AFTERNOON. TOTAL SNOWFALL ACCUMULATIONS OF 2 TO 4 INCHES ARE
POSSIBLE...WITH THE HEAVIER AMOUNTS AT KLNK AND KOMA. SKIES ARE
EXPECTED TO SCATTER OUT THIS EVENING AND EVENTUALLY CLEAR OUT
OVERNIGHT. A COLD FRONT WILL MOVE ACROSS THE TAF SITES BY EARLY
EVENING. THIS COULD PUSH NORTHWEST WINDS UP TO AROUND 10-12KTS
OVERNIGHT AND PRODUCE SOME DRIFTING OF SNOW OVERNIGHT.
KERN
&&
.PREV DISCUSSION... /ISSUED 322 AM CST SUN DEC 8 2013/
DISCUSSION...
DURATION/COVERAGE/AMOUNTS OF SNOW THROUGH THIS EVENING ARE THE
PRIMARY FORECAST CHALLENGES.
SNOW DEVELOPED SATURDAY EVENING ACROSS MUCH OF SOUTHERN NEBRASKA
INCLUDING SOUTHEAST NEBRASKA...AND HAD SPREAD NORTH TO THE PLATTE
RIVER AND THE OMAHA METRO BY MIDNIGHT. THIS WAS SEVERAL HOURS
EARLIER THAN MODELS SHOWED 24 HOURS AGO WHEN THEY WERE PAINTING
SIGNIFICANT BOUNDARY LAYER DRY AIR THAT WOULD NOT BE OVERCOME UNTIL
AFTER MIDNIGHT FOR ALL BUT THE WESTERN CWA. ENHANCED LIFT IN RIGHT
ENTRANCE REGION OF UPPER JET OVERCAME THIS DRY AIR RATHER QUICKLY AS
RADAR RETURNS BLOSSOMED RAPIDLY SATURDAY EVENING IN SOUTH CENTRAL
THEN SOUTHEAST NEBRASKA. 00Z MODELS WERE NOT HANDLING THIS AREA OF
PRECIP WELL AT ALL...INSTEAD FOCUSING ON NORTHERN NEBRASKA BY 06Z.
HOWEVER MESOSCALE MODELS HRRR AND RAP WERE AT LEAST OFFERING BETTER
SOLUTIONS COMPARED TO CURRENT TRENDS.
UPPER TROUGH REMAINED WELL TO OUR WEST THIS MORNING...WITH BASE OF
TROUGH AXIS NEARING THE FOUR CORNERS REGION AT 08Z. A COUPLE OF
SHORTWAVES WERE NOTED IN WATER VAPOR IMAGERY...ONE ROUNDING BASE OF
TROUGH THAT WAS SHOWING ENHANCEMENT IN SOUTHERN ARIZONA...AND A
SECOND WAS SPINNING THROUGH CENTRAL COLORADO. THE FIRST SHORTWAVE
SUGGESTS A STRONG JET SEGMENT THAT WAS NOT HANDLED WELL BY
MODELS...AND EXTRAPOLATION PUTS THE LEFT EXIT REGION OF THAT JET
INTO NEBRASKA LATER THIS MORNING. THIS WILL AGAIN ENHANCE LIFT IN
OUR SOUTHERN/CENTRAL CWA. AND THE COLORADO VORT/SHORTWAVE IS PROGGED
TO WORK EAST INTO NEBRASKA THIS AFTERNOON BEFORE EXITING TO OUR EAST
BY 06Z. AHEAD OF BOTH SHORTWAVES WE WILL SEE CONTINUED ISENTROPIC
UPGLIDE THROUGH THE MORNING AND AFTERNOON BEFORE DOWNGLIDE BEGINS
FROM WEST TO EAST LATE IN THE DAY AND EVENING.
ISENTROPIC ANALYSIS ALONG THE 285K SURFACE INDICATES MIXING RATIOS
OF 2 G/KG WILL CONTINUE TO PUMP INTO OUR SOUTH AND CENTRAL CWA WHERE
LIFT IS EXPECTED TO BE STRONGEST. THIS TRANSLATES TO POTENTIALLY
ANOTHER 4 INCHES OF SNOW IN THOSE AREAS...PUTTING TOTALS IN THE 3 TO
6 INCH RANGE IN MOST OF THE SOUTHERN HALF OF THE CWA. IN THE
NORTHERN HALF AND ESPECIALLY NORTHEAST NEBRASKA...SNOW WAS SLOW TO
BEGIN BUT HAS ENHANCED MARKEDLY OVER THE PAST SEVERAL HOURS. REPORTS
OF AN INCH OR TWO HAVE COME IN FROM NEAR THE SOUTH DAKOTA
BORDER...WITH LESSER AMOUNTS TO THE SOUTH. LIFT IN THAT AREA DOES
NOT LOOK AS STRONG AS TO THE SOUTH...BUT AMOUNTS COULD STILL
APPROACH 3 INCHES BEFORE ENDING. ALREADY HAVE A WINTER WEATHER
ADVISORY GOING FOR MOST OF THE CWA. SOUTHERN AREAS SHOULD EASILY
VERIFY THIS...BUT NORTHERN AREAS COULD STRUGGLE TO REACH THE LOWER
END OF CRITERIA. HOWEVER WILL MAINTAIN ADVISORY FOR ALL CURRENT
AREAS AS SNOW IS JUST GETTING GOING IN OUR NORTH AND EXPECT SOME
ENHANCEMENT DURING THE MORNING.
SNOW SHOULD BE TAPERING IN OUR WEST BY MID AFTERNOON...THEN EASTERN
SECTIONS THIS EVENING. CLEARING SKIES AND FRESH SNOW COVER WILL
ALLOW TEMPERATURES TO DROP BELOW ZERO IN MUCH OF THE CWA. NORTHWEST
WINDS OF 10 TO 15 MPH SHOULD DEVELOP LATER TONIGHT AND MONDAY
MORNING...AND WITH SUB ZERO TEMPERATURES...WIND CHILLS WILL APPROACH
20 BELOW FOR THE START OF THE SCHOOL/WORK WEEK. WILL GO AHEAD AND
ISSUE A WIND CHILL ADVISORY FOR A GOOD PART OF OUR NORTHERN CWA
FOR LATE TONIGHT AND MONDAY MORNING.
ANOTHER SHORTWAVE WILL DIVE INTO THE GREAT LAKES MONDAY
NIGHT...CAUSING SURFACE FLOW TO BECOME SOUTHWESTERLY HERE MONDAY
AFTERNOON. BUT COLD START AND SNOW WILL KEEP HIGHS ONLY IN THE
TEENS. THEN A CLIPPER SYSTEM/SHORTWAVE IS FORECAST THROUGH NORTHEAST
NEBRASKA INTO IOWA TUESDAY NIGHT. AGAIN THIS WILL BRING WEST TO
SOUTHWEST WINDS TO OUR AREA MONDAY NIGHT AND TUESDAY...KEEPING LOWS
ABOVE ZERO AND PUSHING HIGHS INTO THE 20S. MODELS HAVE BEEN
PERSISTENT IN DROPPING A STRIPE OF LIGHT SNOW WITH THIS SYSTEM
TUESDAY NIGHT INTO WEDNESDAY MORNING...SO WILL INSERT SMALL CHANCES
FOR THIS IN OUR NORTHEAST CWA. MUCH COLDER AIR BEHIND THE CLIPPER
WILL KEEP HIGHS IN THE TEENS ON WEDNESDAY. THEN A GRADUAL WARMING
TREND LOOKS ON TRACK FOR THURSDAY INTO SATURDAY AS UPPER FLOW
TRANSITIONS FROM A NORTHWEST TO ZONAL SETUP. HAVE HIGHS CLOSE TO 30
EACH DAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-
012-015>018-030>034-042>045-050>053-065>068-078-088>091.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR NEZ011-012-
015>018-030>034-042>045.
IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043-
055-056-069-079-080-090-091.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR IAZ043-055.
&&
$$
99/99
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
449 AM MST SUN DEC 8 2013
.AVIATION...
12Z TAF CYCLE
IFR/LIFR CIGS AND VSBYS IN BR AND FZFG CONTINUE ACROSS THE EASTERN
PLAINS THIS MORNING...THOUGH THIS SHOULD CONTINUE TO ERODE FROM
WEST TO EAST AS SW WINDS INCREASE THIS MORNING. WILL LIKELY HANG ON
THE LONGEST AT KROW. MEANWHILE...SNOW CONTINUES ACROSS THE NORTH
AND WEST...WITH THE HEAVIEST SNOW BAND OCCURRING ALONG A COLD
FRONT. STRONG AND GUSTY SW TO W WINDS WILL ALSO ARRIVE WITH THE
FRONT AND LAST FOR 1 TO 3 HOURS. THOUGH THE BAND OF SNOW WILL
STRUGGLE TO MAKE IT EAST OF THE CENTRAL MOUNTAIN CHAIN... THE
WIND WILL NOT. GUSTS NEAR 45KT WILL BE POSSIBLE...ESPECIALLY
ALONG AND JUST EAST OF THE CENTRAL MTN CHAIN FROM MID MORNING
THROUGH EARLY AFTN. WINDS WILL DIMINISH LATE THIS AFTERNOON. MAY
SEE SOME LOW CLOUD DEVELOPMENT IN THE VCNTY OF KROW AFT 06Z
TONIGHT.
34
&&
.PREV DISCUSSION...338 AM MST SUN DEC 8 2013...
...STRONGER WINDS AND FRIGID TEMPERATURES TODAY/MONDAY WILL MAKE
FOR THE COLDEST DAYS OF THE ARCTIC STRETCH...
MID-LEVEL SPEED MAX OF 60-80 KNOTS WITHIN BASE OF A
POTENT UPPER LEVEL SHORTWAVE TROUGH TO TRANSLATE EASTWARD OVER
THE AREA TODAY. VERY COLD AIR ALOFT CONTRIBUTING TO A BEAUTIFUL
SATELLITE PRESENTATION EARLY THIS MORNING. COOLING CLOUD TOPS
EVIDENT OVER FAR NW/NC AREAS WHERE CONVECTIVE SNOW BURSTS LIKELY
PRODUCING SHORT-DURATION INTENSE SNOW OVER THE HIGHER TERRAIN FROM
JUST EAST-NORTHEAST OF FARMINGTON TO CHAMA AND AREAS JUST SOUTH.
CHAMA HAD 4 INCHES OF SNOW AS OF MID-EVENING SATURDAY PRIOR TO
THESE MORE FAVORABLE CONDITIONS THAT WILL SHIFT TOWARD THE SANGRES.
OTHERWISE...TRANSITION TO INCREASINGLY OROGRAPHIC SNOWS EXPECTED AS
THE MORNING PROGRESSES WITH BANDED SNOW STRUCTURE EXPECTED ALONG A
SURFACE TO MID- LEVEL FRONTAL ZONE THAT WILL CONTINUE TO PRESS
EAST- SOUTHEAST AND FAVOR WC AREAS ESPECIALLY NEAR THE DIVIDE.
COULD SEE THE REMNANTS OF THIS BAND REACH THE ABQ AREA BY MID- TO
LATE MORNING PER THE LATEST HRRR BUT NOT EXPECTING MUCH IMPACT. OF
GREATER IMPACT FOR MOST AREAS WILL BE INCREASING WIND AND COMBINED
WITH FRIGID TEMPERATURES WILL MAKE IT BRUTAL FOR MUCH OF THE NORTH
AND WEST. DOWNSLOPING WINDS FOR THE FIRST TIME IN MANY DAYS SHOULD
ACTUALLY HELP IMPROVE CONDITIONS ACROSS THE EASTERN PLAINS WHERE
LOW CLOUDS...FREEZING FOG/DRIZZLE WILL CONTINUE THROUGH THE
MORNING ACROSS ROUGHLY THE SOUTHEAST QUARTER. BLOWING SNOW IMPACTS
COULD BE SIGNIFICANT FOR AREAS THAT RECEIVED HEAVY SNOW THIS PAST
THURSDAY AND ARE WELL REMOVED FROM WHERE THE SNOW ACTUALLY FALLS
TODAY.
ANOTHER VERY INTERESTING/CHALLENGING FORECAST TONIGHT INTO MONDAY.
AS THE NEXT REINFORCING AND COLDEST CHUNK OF ARCTIC AIR PLUNGES
SOUTH. AND IT WILL DO SO VERY SIMILAR TO HOW THE INITIAL BLAST
PLAYED OUT LAST THURSDAY. THAT IS BREAKING DOWN BOTH SIDES OF THE
DIVIDE. THERE WILL BE A BACKDOOR SEGMENT THAT WILL PUSH SOUTH AND
WEST A LITTLE FASTER THAN THE REINFORCING SURGE OF ARCTIC AIR
ACROSS WESTERN NEW MEXICO. AT THE SAME TIME...A POSITIVELY TILTED
UPPER TROUGH WILL BE SAGGING SOUTH-SOUTHEAST OVER THE AREA. THE
GFS HAS BEEN TARGETING A MESOSCALE BAND OF SNOW AHEAD OF THE UPPER
TROUGH AND ALONG THE SOUTHWARD- MOVING ARCTIC REINFORCEMENT MUCH
FARTHER WEST AND NORTH COMPARED TO ITS COUNTERPARTS. ECMWF AND
ESPECIALLY THE NAM ARE CONSIDERABLY DRIER AND FOCUS MOST THEIR QPF
FROM EAST- CENTRAL INTO SOUTH- CENTRAL NEW MEXICO. WHERE THIS
BANDS SET UP WILL LIKELY MEAN THE DIFFERENCE BETWEEN A HIGH-END
ADVISORY FOR SEVERAL INCHES OF SNOW OR NO ADVISORY. FOR NOW HAVE
KEPT WITH PREVIOUS STRONG TREND TOWARD THE GFS. BOTTOM LINE...WE
ARE NOT DONE WITH SNOW IMPACTS.
THEREAFTER...A BRUTALLY COLD PATTERN MONDAY NIGHT ESPECIALLY WITH
FRESH SNOW COVER AND CLEARING SKIES FOR SOME AREAS. OTHERWISE A
QUIET PATTERN FINALLY INDICATED INTO TUESDAY WITH ANY LINGERING
SNOW ENDING FROM EAST TO WEST. WE WILL FINALLY BEGIN TO MAKE THE
TURN BY THE MIDDLE PART OF THE WEEK BUT STILL UNCERTAINTY
REGARDING HOW A LOW LATITUDE LOW MAY EVOLVE FOR THE LATE WEEK
PERIOD. KJ
.FIRE WEATHER...
NOW HAS BEGUN ACROSS THE NORTH AND WEST THIS MORNING AS AN UPPER
LEVEL TROUGH SWINGS OVER NM. VERY HIGH SNOW RATIOS EXPECTED WITH
THIS COLD AIRMASS...AND SEVERAL INCHES OF SNOW HAS ALREADY BEEN
REPORTED ACROSS THE SAN JUAN MOUNTAINS. COLD FRONT IS MARCHING INTO
NORTHWEST NM AND IS CURRENTLY THROUGH FARMINGTON AND GALLUP. THIS
FRONT WILL CONTINUE TO SWEEP EASTWARD TODAY CREATING WINDY
CONDITIONS BEHIND IT...ESPECIALLY ACROSS THE CENTRAL MOUNTAIN CHAIN
AND ADJACENT HIGHLANDS TO THE EAST. THE INCREASE IN WIND SPEED WILL
RESULT IN VERY GOOD TO EXCELLENT VENTILATION FOR ALL BUT THE
SOUTHERN PORTIONS OF THE RIO GRANDE VALLEY AND THE EAST CENTRAL
PLAINS. ALSO BECAUSE OF THE WINDS...SPECIFICALLY THE DOWNSLOPE
COMPONENT ACROSS THE EAST...TEMPERATURES ARE EXPECTED TO WARM ABOVE
THE FREEZING MARK FOR THE FIRST TIME IN SEVERAL DAYS...THOUGH MOST
AREAS WILL REMAIN 10 TO 20 DEGREES BELOW NORMAL.
THE WARM-UP TODAY WILL BE SHORT-LIVED AS MUCH COLDER AIR FILTERS
INTO THE AREA TONIGHT...AND MOST AREAS ON MONDAY WILL STRUGGLE TO
REACH THE FREEZING MARK. A SECONDARY TROUGH WILL SWING OVER THE
STATE ON MONDAY AS WELL...AND OPERATIONAL MODELS ARE STILL AT ODDS
WITH PRECIPITATION POTENTIAL. HOWEVER...GFS ENSEMBLE GUIDANCE
INCREASES CONFIDENCE THAT THERE WILL BE A BAND OF SNOW DEVELOPING
ALONG A FRONT STRETCHING FROM THE SW MTNS TOWARD THE SANDIA/MANZANO
MOUNTAINS. ADDITIONALLY...CONVERGENCE DUE TO THE BACK DOOR SEGMENT
OF THE FRONT MAY ENHANCE SNOWFALL POTENTIAL OVER THE CENTRAL AND
SOUTH CENTRAL HIGHLANDS. SHOULD THIS OCCUR A COUPLE INCHES OF SNOW
ARE POSSIBLE...THOUGH IT SHOULD BE MENTIONED THAT THE NAM AND ECMWF
MODELS SHOW VERY LITTLE QPF...IF ANY.
WINDS DUE TO THE FRONT WILL KEEP VENT RATES IN THE GOOD TO VERY GOOD
CATEGORY MONDAY ACROSS THE CENTRAL AND WEST...WITH POOR VENTILATION
PREVAILING ACROSS THE EAST.
COOL NORTHWEST FLOW WILL BE IN STORE FOR TUESDAY AND WEDNESDAY...AND
TEMPERATURES WILL REMAIN UP TO 20 DEGREES BELOW NORMAL. GENERALLY
LIGHT WINDS AND POOR MIXING WILL RESULT IN POOR VENTILATION
AREAWIDE. HOWEVER...A BACK DOOR COLD FRONT WILL SLIDE DOWN THE
PLAINS ON WEDNESDAY.
MODELS SHOW A DISTURBANCE MOVING ACROSS THE AREA ON
THURSDAY...THOUGH IT IS UNCLEAR WHERE...IF ANY...PRECIPITATION
OCCURS WITH THIS SYSTEM. MIXING WILL REMAIN POOR...THUS SO WILL
VENTILATION. THE UPPER AIR PATTERN LOOKS TO REMAIN ACTIVE BEYOND
THURSDAY...THOUGH MODELS DIVERGE ON PLACEMENT AND TIMING OF STORM
SYSTEMS. 34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ521>524-526>529-533-539-540.
WINTER WEATHER ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE
FOLLOWING ZONES...NMZ501-502-504>506-511-512-515>517.
WINTER STORM WARNING UNTIL 4 PM MST THIS AFTERNOON FOR THE
FOLLOWING ZONES...NMZ503-510-513-514.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
338 AM MST SUN DEC 8 2013
...STRONGER WINDS AND FRIGID TEMPERATURES TODAY/MONDAY WILL MAKE
FOR THE COLDEST DAYS OF THE ARCTIC STRETCH...
.DISCUSSION...MID-LEVEL SPEED MAX OF 60-80 KNOTS WITHIN BASE OF A
POTENT UPPER LEVEL SHORTWAVE TROUGH TO TRANSLATE EASTWARD OVER
THE AREA TODAY. VERY COLD AIR ALOFT CONTRIBUTING TO A BEAUTIFUL
SATELLITE PRESENTATION EARLY THIS MORNING. COOLING CLOUD TOPS
EVIDENT OVER FAR NW/NC AREAS WHERE CONVECTIVE SNOW BURSTS LIKELY
PRODUCING SHORT-DURATION INTENSE SNOW OVER THE HIGHER TERRAIN FROM
JUST EAST-NORTHEAST OF FARMINGTON TO CHAMA AND AREAS JUST SOUTH.
CHAMA HAD 4 INCHES OF SNOW AS OF MID-EVENING SATURDAY PRIOR TO
THESE MORE FAVORABLE CONDITIONS THAT WILL SHIFT TOWARD THE SANGRES.
OTHERWISE...TRANSITION TO INCREASINGLY OROGRAPHIC SNOWS EXPECTED AS
THE MORNING PROGRESSES WITH BANDED SNOW STRUCTURE EXPECTED ALONG A
SURFACE TO MID- LEVEL FRONTAL ZONE THAT WILL CONTINUE TO PRESS
EAST- SOUTHEAST AND FAVOR WC AREAS ESPECIALLY NEAR THE DIVIDE.
COULD SEE THE REMNANTS OF THIS BAND REACH THE ABQ AREA BY MID- TO
LATE MORNING PER THE LATEST HRRR BUT NOT EXPECTING MUCH IMPACT. OF
GREATER IMPACT FOR MOST AREAS WILL BE INCREASING WIND AND COMBINED
WITH FRIGID TEMPERATURES WILL MAKE IT BRUTAL FOR MUCH OF THE NORTH
AND WEST. DOWNSLOPING WINDS FOR THE FIRST TIME IN MANY DAYS SHOULD
ACTUALLY HELP IMPROVE CONDITIONS ACROSS THE EASTERN PLAINS WHERE
LOW CLOUDS...FREEZING FOG/DRIZZLE WILL CONTINUE THROUGH THE
MORNING ACROSS ROUGHLY THE SOUTHEAST QUARTER. BLOWING SNOW IMPACTS
COULD BE SIGNIFICANT FOR AREAS THAT RECEIVED HEAVY SNOW THIS PAST
THURSDAY AND ARE WELL REMOVED FROM WHERE THE SNOW ACTUALLY FALLS
TODAY.
ANOTHER VERY INTERESTING/CHALLENGING FORECAST TONIGHT INTO MONDAY.
AS THE NEXT REINFORCING AND COLDEST CHUNK OF ARCTIC AIR PLUNGES
SOUTH. AND IT WILL DO SO VERY SIMILAR TO HOW THE INITIAL BLAST
PLAYED OUT LAST THURSDAY. THAT IS BREAKING DOWN BOTH SIDES OF THE
DIVIDE. THERE WILL BE A BACKDOOR SEGMENT THAT WILL PUSH SOUTH AND
WEST A LITTLE FASTER THAN THE REINFORCING SURGE OF ARCTIC AIR
ACROSS WESTERN NEW MEXICO. AT THE SAME TIME...A POSITIVELY TILTED
UPPER TROUGH WILL BE SAGGING SOUTH-SOUTHEAST OVER THE AREA. THE
GFS HAS BEEN TARGETING A MESOSCALE BAND OF SNOW AHEAD OF THE UPPER
TROUGH AND ALONG THE SOUTHWARD- MOVING ARCTIC REINFORCEMENT MUCH
FARTHER WEST AND NORTH COMPARED TO ITS COUNTERPARTS. ECMWF AND
ESPECIALLY THE NAM ARE CONSIDERABLY DRIER AND FOCUS MOST THEIR QPF
FROM EAST- CENTRAL INTO SOUTH- CENTRAL NEW MEXICO. WHERE THIS
BANDS SET UP WILL LIKELY MEAN THE DIFFERENCE BETWEEN A HIGH-END
ADVISORY FOR SEVERAL INCHES OF SNOW OR NO ADVISORY. FOR NOW HAVE
KEPT WITH PREVIOUS STRONG TREND TOWARD THE GFS. BOTTOM LINE...WE
ARE NOT DONE WITH SNOW IMPACTS.
THEREAFTER...A BRUTALLY COLD PATTERN MONDAY NIGHT ESPECIALLY WITH
FRESH SNOW COVER AND CLEARING SKIES FOR SOME AREAS. OTHERWISE A
QUIET PATTERN FINALLY INDICATED INTO TUESDAY WITH ANY LINGERING
SNOW ENDING FROM EAST TO WEST. WE WILL FINALLY BEGIN TO MAKE THE
TURN BY THE MIDDLE PART OF THE WEEK BUT STILL UNCERTAINTY
REGARDING HOW A LOW LATITUDE LOW MAY EVOLVE FOR THE LATE WEEK
PERIOD. KJ
&&
.FIRE WEATHER...
NOW HAS BEGUN ACROSS THE NORTH AND WEST THIS MORNING AS AN UPPER
LEVEL TROUGH SWINGS OVER NM. VERY HIGH SNOW RATIOS EXPECTED WITH
THIS COLD AIRMASS...AND SEVERAL INCHES OF SNOW HAS ALREADY BEEN
REPORTED ACROSS THE SAN JUAN MOUNTAINS. COLD FRONT IS MARCHING INTO
NORTHWEST NM AND IS CURRENTLY THROUGH FARMINGTON AND GALLUP. THIS
FRONT WILL CONTINUE TO SWEEP EASTWARD TODAY CREATING WINDY
CONDITIONS BEHIND IT...ESPECIALLY ACROSS THE CENTRAL MOUNTAIN CHAIN
AND ADJACENT HIGHLANDS TO THE EAST. THE INCREASE IN WIND SPEED WILL
RESULT IN VERY GOOD TO EXCELLENT VENTILATION FOR ALL BUT THE
SOUTHERN PORTIONS OF THE RIO GRANDE VALLEY AND THE EAST CENTRAL
PLAINS. ALSO BECAUSE OF THE WINDS...SPECIFICALLY THE DOWNSLOPE
COMPONENT ACROSS THE EAST...TEMPERATURES ARE EXPECTED TO WARM ABOVE
THE FREEZING MARK FOR THE FIRST TIME IN SEVERAL DAYS...THOUGH MOST
AREAS WILL REMAIN 10 TO 20 DEGREES BELOW NORMAL.
THE WARM-UP TODAY WILL BE SHORT-LIVED AS MUCH COLDER AIR FILTERS
INTO THE AREA TONIGHT...AND MOST AREAS ON MONDAY WILL STRUGGLE TO
REACH THE FREEZING MARK. A SECONDARY TROUGH WILL SWING OVER THE
STATE ON MONDAY AS WELL...AND OPERATIONAL MODELS ARE STILL AT ODDS
WITH PRECIPITATION POTENTIAL. HOWEVER...GFS ENSEMBLE GUIDANCE
INCREASES CONFIDENCE THAT THERE WILL BE A BAND OF SNOW DEVELOPING
ALONG A FRONT STRETCHING FROM THE SW MTNS TOWARD THE SANDIA/MANZANO
MOUNTAINS. ADDITIONALLY...CONVERGENCE DUE TO THE BACK DOOR SEGMENT
OF THE FRONT MAY ENHANCE SNOWFALL POTENTIAL OVER THE CENTRAL AND
SOUTH CENTRAL HIGHLANDS. SHOULD THIS OCCUR A COUPLE INCHES OF SNOW
ARE POSSIBLE...THOUGH IT SHOULD BE MENTIONED THAT THE NAM AND ECMWF
MODELS SHOW VERY LITTLE QPF...IF ANY.
WINDS DUE TO THE FRONT WILL KEEP VENT RATES IN THE GOOD TO VERY GOOD
CATEGORY MONDAY ACROSS THE CENTRAL AND WEST...WITH POOR VENTILATION
PREVAILING ACROSS THE EAST.
COOL NORTHWEST FLOW WILL BE IN STORE FOR TUESDAY AND WEDNESDAY...AND
TEMPERATURES WILL REMAIN UP TO 20 DEGREES BELOW NORMAL. GENERALLY
LIGHT WINDS AND POOR MIXING WILL RESULT IN POOR VENTILATION
AREAWIDE. HOWEVER...A BACK DOOR COLD FRONT WILL SLIDE DOWN THE
PLAINS ON WEDNESDAY.
MODELS SHOW A DISTURBANCE MOVING ACROSS THE AREA ON
THURSDAY...THOUGH IT IS UNCLEAR WHERE...IF ANY...PRECIPITATION
OCCURS WITH THIS SYSTEM. MIXING WILL REMAIN POOR...THUS SO WILL
VENTILATION. THE UPPER AIR PATTERN LOOKS TO REMAIN ACTIVE BEYOND
THURSDAY...THOUGH MODELS DIVERGE ON PLACEMENT AND TIMING OF STORM
SYSTEMS. 34
&&
.AVIATION...
06Z TAF CYCLE
IFR AND MVFR CIGS COVERAGE HAS DECREASED IN VCNTY OF RIO GRANDE
VALLEY...BUT MVFR TO LOCALLY IFR CIGS MAY REDEVELOP IN THIS
AREA AFTER 10Z...MUCH MORE SO THOUGH NORTH OF INTERSTATE 40. SAF
TAF SITE SHOULD SEE SIGNIFICANT IMPROVEMENT TO SCT OR AT LEAST
HIGHER CIGS BETWEEN 07Z AND 10Z WITH SOME LOWERING AGAIN
THEREAFTER. SOME CIG HEIGHT RISES AT LVS AND PERHAPS ROW AFTER
11Z...BUT LESS LIKELY THAN SAF TO IMPROVE TO SCT CLOUDS. OTHERWISE
MOST OF THE EASTERN PLAINS LIKELY TO STAY IN PRETTY SOLID MVFR TO
IFR CIGS OVERNIGHT WITH IMPROVEMENT TO SCT AFTER 15Z. CIGS AND
VSBY LOWERING EXPECTED AFTER 06Z AT FMN AND GUP WITH SOME AREAS OF
LIGHT TO BRIEFLY MODERATE SNOW. MT OBSCURATIONS LIKELY MOST PEAKS
AND RANGES OVERNIGHT. WINDS IN THE LOWER BOUNDARY LAYER WILL
LIKELY INCREASE MODESTLY OVERNIGHT WITH GREATER INCREASES HIGHER
TERRAIN...BUT STRONGER WINDS LIKELY ACROSS MUCH OF THE AREA LATE
MORN AND AFTN SUNDAY. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 26 5 21 -1 / 30 0 5 0
DULCE........................... 23 -4 18 -16 / 40 5 5 0
CUBA............................ 27 6 21 -7 / 40 10 20 0
GALLUP.......................... 31 4 25 -8 / 30 5 20 0
EL MORRO........................ 31 1 25 -10 / 40 10 30 5
GRANTS.......................... 34 8 28 -5 / 30 5 20 0
QUEMADO......................... 38 15 29 -1 / 30 5 20 5
GLENWOOD........................ 44 22 38 12 / 10 5 20 0
CHAMA........................... 19 -8 13 -16 / 60 10 5 0
LOS ALAMOS...................... 30 9 23 -2 / 40 10 30 5
PECOS........................... 27 8 20 -1 / 30 10 30 5
CERRO/QUESTA.................... 22 -4 16 -13 / 40 10 10 0
RED RIVER....................... 17 -6 11 -16 / 60 10 20 0
ANGEL FIRE...................... 21 -10 15 -18 / 50 10 20 5
TAOS............................ 25 0 19 -14 / 30 5 10 0
MORA............................ 26 4 20 -4 / 30 5 30 5
ESPANOLA........................ 33 11 27 3 / 20 5 10 0
SANTA FE........................ 28 9 21 1 / 30 10 20 5
SANTA FE AIRPORT................ 31 12 24 2 / 20 5 20 5
ALBUQUERQUE FOOTHILLS........... 36 17 30 6 / 10 5 30 5
ALBUQUERQUE HEIGHTS............. 37 20 30 10 / 5 0 30 0
ALBUQUERQUE VALLEY.............. 39 15 32 5 / 5 0 30 0
ALBUQUERQUE WEST MESA........... 38 18 31 9 / 5 0 30 0
LOS LUNAS....................... 42 21 34 9 / 5 0 30 0
RIO RANCHO...................... 37 18 31 9 / 10 0 30 0
SOCORRO......................... 48 24 37 15 / 0 0 30 5
SANDIA PARK/CEDAR CREST......... 33 10 26 -3 / 30 10 40 5
TIJERAS......................... 34 12 27 -5 / 20 5 40 5
MORIARTY/ESTANCIA............... 32 -1 26 -13 / 20 5 30 10
CLINES CORNERS.................. 30 11 21 2 / 30 5 50 20
GRAN QUIVIRA.................... 37 18 29 7 / 20 0 40 20
CARRIZOZO....................... 43 24 37 16 / 10 0 40 20
RUIDOSO......................... 38 21 32 16 / 10 0 50 30
CAPULIN......................... 28 3 16 2 / 10 5 10 5
RATON........................... 29 2 20 -2 / 20 5 10 5
SPRINGER........................ 31 4 21 -3 / 10 5 10 5
LAS VEGAS....................... 29 8 20 -1 / 20 5 20 10
CLAYTON......................... 33 6 18 7 / 5 5 10 10
ROY............................. 33 7 19 3 / 5 5 20 10
CONCHAS......................... 41 12 25 6 / 5 0 30 10
SANTA ROSA...................... 41 15 26 10 / 5 0 30 20
TUCUMCARI....................... 45 12 28 10 / 0 5 20 20
CLOVIS.......................... 44 15 26 14 / 0 5 20 20
PORTALES........................ 44 16 27 13 / 0 0 20 20
FORT SUMNER..................... 43 18 29 13 / 0 5 20 20
ROSWELL......................... 49 25 36 19 / 0 0 10 30
PICACHO......................... 47 24 34 17 / 0 0 30 30
ELK............................. 46 24 34 18 / 0 0 40 30
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ521>524-526>529-533-539-540.
WINTER WEATHER ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE
FOLLOWING ZONES...NMZ501-502-504>506-511-512-515>517.
WINTER STORM WARNING UNTIL 4 PM MST THIS AFTERNOON FOR THE
FOLLOWING ZONES...NMZ503-510-513-514.
&&
$$
41
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1025 AM EST SUN DEC 8 2013
.SYNOPSIS...
CHILLY AND DAMP CONDITIONS WILL PREVAIL TODAY BEFORE A WARM FRONT
BRINGS A SHORT-LIVED WARM-UP ON MONDAY. A STRONG COLD FRONT WILL
MOVE ACROSS THE AREA TUESDAY...BRINGING A REINFORCEMENT OF COOLER
AIR THROUGH MID WEEK. ANOTHER STORM SYSTEM MAY BRING RAIN TO THE
REGION NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM SUNDAY...PERSISTENCE EMPLOYED FOR THE NEAR TERM
UPDATE AS THE METEOROLOGICAL SET-UP SUPPORTS A COOL AND WET REGIME
TO PREVAIL ALL DAY AND OVERNIGHT. NEAR TERM MODEL DATA HOWEVER
POINTS TO ATYPICAL TEMPERATURE CURVES TONIGHT...WITH A SLOW CLIMB
FROM THE MIDDLE AND UPPER 40S TO AROUND 50 DEGREES BY DAYBREAK
MONDAY AS SW FLOW ALOFT STRENGTHENS AND SCOURS THE SHALLOW AND
COOL WEDGE OF MARITIME INFLUENCE. HOW QUICKLY THIS OCCURS REMAINS
UP FOR ASSESSMENT...BUT IT APPEARS THE WEDGE WILL REMAIN
ENTRENCHED OVER THE FORECAST AREA THROUGH DAYBREAK MONDAY. THIS
MAKE TEMP AND WIND FORECASTS A BIT MORE PREDICTABLE THAN THE
TRANSITION OF WARMING ON MONDAY MORNING. MAXIMUM TEMPERATURES AS A
RESULT WILL LIKELY OCCUR FOR TODAYS 24 HOUR CALENDER PERIOD JUST
PRIOR TO 12Z/7AM MONDAY MORNING.
PRECIPITATION-WISE THE OVER-RUNNING WEDGE PATTERN WILL SUPPORT
OCCASIONAL DRIZZLE AREA-WIDE THROUGH TONIGHT. IN FACT AS THE WARM
FRONTAL TYPE PROCESS GEARS UP EARLY ON MONDAY...AREAS OF DENSE FOG
AND DRIZZLE MAY EXPAND OVER THE FORECAST AREA TO START THE WEEK.
P-TYPE ANALYSIS SHOWS THAT BOTH STRATIFORM AND CONVECTIVE TYPE
RAINFALL WILL PREVAIL OVER THE AREA THROUGH TONIGHT...BUT NOT A
LARGE OR SIGNIFICANT CONTRIBUTION FROM EITHER. WILL CONTINUE TO
ADVERTISE SCATTERED TO LIKELY POP VALUES TO HIGHLIGHT DECENT
PROBABILITIES OF MEASURABLE PRECIPITATION HOWEVER ACCOMPANIED BY
INTERMITTENT DRIZZLE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...SHARP CLASSIC COLD AIR DAMMING EVENT WILL COME
TO AN END EARLY IN THE PERIOD WITH THE FORECAST DILEMMA BEING
FORECAST HIGHS FOR MONDAY. THE MET CONTINUES TO ADVERTISE THE
COOLER NUMBERS AND WITH LINGERING LOW LEVEL MOISTURE AND NEARING
THE WINTER SOLSTICE...THESE SEEM MORE REASONABLE ALTHOUGH WITH ANY
APPRECIABLE CLOUD OR EARLY BREAKS...VERY WARM TEMPERATURES IN THE
850-900MB LAYER COULD MIX DOWN.
THE FORECAST SOLUTIONS REGARDING THE FRONT TUESDAY CONTINUE TO WAVER
AND SLOW THE PROGRESSION OF THE FRONT. IN FACT...THE GFS SHOWS A
SECONDARY AREA OF QPF DEVELOPING WITH THE SOUTHWEST FLOW WEDNESDAY
THUS SLOWING THE FRONT FOR TUESDAY. THIS IS THE FIRST CYCLE THIS HAS
APPEARED SO I DID MAINTAIN THE LIKELY POPS FOR TUESDAY AND INCREASED
THE LONGEVITY OF THE MOISTURE FOR TUESDAY EVENING. NO CHANGES TO
TEMPERATURE FORECAST FOR TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...CONFIDENCE HAS WALKED BACK SLIGHTLY WITH REGARDS
TO THE EVENTS FOR THE EXTENDED FORECAST. THE NEW AND WETTER
SOLUTION AS ADVERTISED BY THE GFS OPERATIONAL PUTS WEDNESDAY IN
QUESTION ALTHOUGH I DID NOT CHANGE THE DRY FORECAST AT LEAST FOR
NOW TO SEE IF MORE SOLUTIONS COME IN SIMILAR. THE GFS ALSO
CONTINUES TO SHOW A FAIRLY STRONG SOUTHERN STREAM SYSTEM FOR THE
END OF THE WEEK INSTEAD OF THE WEAKLY FORCED COASTAL TROUGH. I
HAVE ALONG WITH ADJACENT OFFICES INCREASED POPS AND CLOUD COVER
FOR THE END OF THE PERIOD. NO CHANGES TO THE TEMPERATURE FORECAST
ALTHOUGH ONCE AGAIN THE READINGS MAY SEE SOME CHANGES DEPENDING ON
THE MASS FIELDS.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AS OF 15Z...PREDOMINATELY IFR CONDITIONS THIS MORNING WITH
STRATUS AND OCCASIONAL LIGHT DRIZZLE. THERE IS A BATCH OF HEAVIER
SHOWERS NOW MOVING THROUGH THE NORTHERN THIRD OF THE
CWA...ASSOCIATED WITH A WEAK DISTURBANCE. EXPECT THIS AREA OF
SHOWERS TO MOVE NORTHEAST AND OUT OF THE REGION BY 13Z. THE WEDGE
WILL PROBABLY STAY IN PLACE THROUGH THE FORECAST PERIOD...PERHAPS
LIFTING ALONG THE COAST BY 10-11Z ON MONDAY.
EXTENDED OUTLOOK...UNSETTLED WEATHER THROUGH THE EXTENDED PERIOD
WITH LIFR/IFR/MVFR CONDITIONS DUE TO A NEARLY STATIONARY FRONT
THROUGH MONDAY. SHOWERS LIKELY TUESDAY FOLLOWED BY ANOTHER COLD
FRONTAL PASSAGE.
&&
.MARINE...
NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1025 AM SUNDAY...THE SCA HAS BEEN EXTENDED TO MID-
AFTERNOON TODAY FOR ALL WATERS. THE NE WINDS CONTINUE TO HOWL AT
15 TO 25 KT WITH GUSTS APPROACHING 30 KT OFF CAPE FEAR EARLY THIS
MORNING. WITH A SLIGHTLY SLOWER BREAKDOWN IN THE WEDGE BEING
FORECAST DURING THIS PERIOD...HAVE SLOWED THE DIMINISHING TREND OF
THE NE WINDS ACROSS THE LOCAL WATERS TODAY THROUGH TONIGHT. THIS
IS DEPICTED WELL BY THE HOURLY HRRR MODEL RUNS ILLUSTRATING
PROGGED SFC WINDS.
THIS WILL ALSO PRODUCE A SLOWER SUBSIDING TREND TO THE SIGNIFICANT
SEAS FROM ROUGHLY 4 TO 7 FT EARLY THIS AM...TO 2 TO 5 FT BY SUNDAY
EVENING. THE MAKE-UP OF THE SIGNIFICANT SEAS WILL REMAIN FROM THE
LOCALLY PRODUCED WIND DRIVEN VARIETY...WITH AVERAGE PERIODS AROUND
5 SECONDS.
SEA FOG MAY BECOME AN ISSUE ONCE AGAIN DURING THE PRE-DAWN MONDAY
HRS BUT LIKELY HOLD OFF INTO THE NEXT PERIOD WHEN S-SW WINDS ACROSS
LOCAL SSTS IN THE 50S OCCUR.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...LIGHT AND ESSENTIALLY VARIABLE WINDS WILL
QUICKLY FIND DEFINITION AS A SOUTHWEST FLOW OF 15-20 KNOTS DEVELOPS
MIDDAY MONDAY. THIS FLOW WILL CONTINUE THROUGH MOST OF THE DAY
TUESDAY BEFORE A LONG ADVERTISED FRONT MOVES ACROSS THE WATERS. BY
0600 UTC WEDNESDAY WINDS WILL BE NORTH ACROSS ALL WATERS WITH THE
SAME 15-20 KNOTS. THE CHANGE IN FETCH AND THE FACT WINDS SEEM TO
REMAIN CAPPED AT 20 KNOTS SHOULD KEEP SEAS BELOW FLAG CRITERIA IN A
2-4 FOOT RANGE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...A NORTH TO NORTHEASTERLY FLOW WILL GREET
MARINERS INITIALLY WITH A FEW HOURS OF 15-20 KNOTS DIMINISHING
SLIGHTLY TO 10-15 KNOTS BY WEDNESDAY EVENING. SLOW MOVING HIGH
PRESSURE AND LOW PRESSURE WELL OFFSHORE WILL KEEP THIS FLOW IN
PLACE THROUGH THURSDAY. SEAS SHOULD REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ250-
252-254-256.
&&
$$
NEAR TERM...DOUG/MJC
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
956 AM EST SUN DEC 8 2013
.SYNOPSIS...
LOW PRESSURE TRAVELING UP THE APPALACHIANS WILL BRING A MIXTURE OF
WINTRY PRECIPITATION TODAY INTO TONIGHT. HIGH PRESSURE WILL TRY TO
BUILD IN ON MONDAY...BUT ANOTHER WEAK SYSTEM WILL AFFECT THE
REGION ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DECENT ISENTROPIC LIFT COMBINING WITH UPR LEVEL DIVERGENCE FROM
THE RR QUAD ENTRANCE REGION OF UPR LEVEL JET WILL PRODUCE
WIDESPREAD PCPN ACRS THE REGION THIS MORNING INTO THE FIRST PART OF
THIS AFTERNOON. WAA WILL GRADUALLY WARM ATMOSPHERIC COLUMN ALOFT FROM
SE TO NW THROUGH THE DAY. AS THIS OCCURS...SNOW WILL TRANSITION TO
A MIXTURE OF SLEET AND FREEZING RAIN. IT SHOULD WARM UP ENOUGH IN
THE FAR SE LATE THIS AFTERNOON FOR LIQUID PCPN. UPDATE THIS
MORNING WAS TO BUMP UP SNOWFALL AMOUNTS A BIT IN THE SE CWFA AS
SOME BURSTS OF MODERATE SNOW HAS ALREADY RESULTED IN ACCUMS AROUND
AN INCH. SO...2 TO 3 LOOKS GOOD HERE WITH 1 TO 2 FARTHER NORTH IN
DAYTON AND COLUMBUS METROS AND LESS THAN AN INCH NORTHWEST. LATEST
MODEL SINDICATE THAT WE COULD END UP WITH LIGHTER PCPN THIS
EVENING/OVERNIGHT OVER MUCH OF THE REGION DUE TO DEEP MOISTURE
EXITING AND FORCING REMAINING FOCUSED NEAR THE SE WITH A LOW LEVEL
JET. WITH WARM TEMPS ALOFT AND SFC TEMPS NEAR OR SLIGHTLY BELOW
FREEZING WILL RESULT IN EITHER LIGHT FREEZING RAIN OR FREEZING
DRIZZLE. HEADLINES WILL HAVE TO BE ADJUSTED AT SOME POINT. TOSSED
AROUND ADDING OUR NW CWFA IN AN ADVISORY...BUT WILL WAIT FOR SOME
NEWER MODEL RUNS TO SEE IF PCPN WILL BE ENOUGH TO DO SO. TEMPS
STARTING OUT COLD WITH ANY LIGHT LIQUID PCPN WITH SFC TEMPS BELOW
FREEZING COULD CAUSE SOME ISSUES ON UNTREATED SIDEWALKS AND ROADS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THE DEEP MOISTURE BEGINS TO BE SHUNTED E AT THE BEGINNING OF THE
PERIOD...LEAVING THE W WITH VERY SHALLOW MOISTURE AND WEAKENING
LIFT. THIS IS A SETUP FOR MORE OF A FZDZ/FZRA SCENARIO AS
COMPARED TO SN/PL. THEREFORE BEGAN TO LOWER THE POPS IN THE W AND
INTRODUCED MORE OF THE FZDZ/FZRA. EXPECT MUCH OF THE AREA TO MAKE
THE CHANGE OVER AS TONIGHT PROGRESSES. THE EXCEPTION WILL BE THE
SE/E WHERE TEMPERATURES MIGHT STAY UP ALL NIGHT THEREFORE STAYING
ALL RAIN. THE ADVISORY IN THOSE LOCATIONS MIGHT BE TOO LONG...BUT
WILL NOT CHANGE THE TIMING RIGHT NOW. INSTEAD WILL LET LATER
SHIFTS CANCEL IT IF IT IS NOT NEEDED. LOWS TONIGHT SHOULD STAY UP
IN THE LOWER TO MID 30S IN THE SE...BUT WILL FALL INTO THE UPPER
20S BACK TO THE W AS THE COOLER AIR WORKS IN ON THE BACKSIDE OF
THE SYSTEM
AS THE SYSTEM SLIDES E EARLY MONDAY...THE REGION WILL BE STUCK
UNDER A SUBSIDENCE INVERSION...WHICH SHOULD KEEP LOW CLOUDS IN
THROUGHOUT THE DAY. RIGHT NOW ENDED THE DZ/FZDZ MONDAY MORNING...BUT
WITH THE LOW CLOUDS THE LIGHT PCPN COULD LINGER.
MONDAY NIGHT INTO TUESDAY SEES A SPLIT LEVEL FLOW DEVELOP WITH
A NRN STREAM VORT PIVOTING INTO THRU THE OHIO VALLEY LATE MONDAY
NIGHT INTO TUESDAY. MODELS PRODUCE AN RIBBON OF SNOW ALONG THE
LEADING EDGE OF THE ARCTIC AIR...WITH THE NAM THE QUICKEST AS IT
PUSHES THE SNOW IN MONDAY NIGHT. THE GFS AND ECMWF WAIT UNTIL
TUESDAY TO BRING THIS FEATURE IN. WILL LEAN TOWARD THE GFS/ECMWF
SOLUTION AND WILL KEEP A MENTION OF SNOW ACRS SE HALF OF FA
TUESDAY.
HIGHS MONDAY AND TUESDAY WILL REMAIN MUCH BELOW NORMAL. ON MONDAY
THEY WILL BE IN THE UPPER 20S IN THE NW TO THE MID 30S IN THE SE.
THEN ON TUESDAY WITH THE WEATHER SYSTEM WORKING THROUGH HIGHS WILL
ONLY REACH THE LOWE 20S IN THE N AND THE LOWER 30S IN THE S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE TO NOSE INTO THE OHIO VALLEY WEDNESDAY WITH WEAK
SYSTEM DROPPING THRU THE GREAT LAKES. THE FAVORABLE MSTR/LIFT TO
STAY TO OUR NORTH...SO HAVE MAINTAINED A DRY FCST WED. COLD
TEMPERATURES TO PERSIST WITH LOWS AROUND 10 DEGREES WEST TO 15
DEGREES SE AND HIGHS LOWER/MIDDLE 20S NW TO THE LOWER 30S SE.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION THURSDAY/FRIDAY TIME
FRAME. COLD TEMPERATURES TO CONTINUE THURSDAY WITH MORNING LOWS
FROM SINGLE DIGITS OVER THE WEST WHERE SNOW COVER EXISTS TO NEAR 15
SE. HIGHS TO RANGE FROM THE LOWER 20S NW TO NEAR 30 SE.
SOME MODERATION TO TEMPERATURES EXPECTED FRIDAY ON BACK SIDE OF SFC
HIGH PRESSURE WITH HIGHS FROM LOWER 30S NW TO THE UPPER 30S SE.
MID LEVEL FLOW BACKS WITH SYSTEM EXPECTED TO DEVELOP ALONG THE
EASTERN SEABOARD LATE FRIDAY INTO SATURDAY. ILN FA IS ON THE FAR NW
FRINGE OF THIS SYSTEM AND HAVE LIMITED ANY MENTION OF PRECIP TO A
SLIGHT CHC OF A SNOW SHOWER IN THE FAR SE LATE FRIDAY NIGHT INTO
SATURDAY.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
CIGS WILL CONTINUE TO LOWER THIS MORNING AS MOISTURE OVERSPREADS
THE ESTABLISHED COLD AIR DOME IN PLACE OVER THE OHIO VALLEY. CIGS
WILL DROP TO THE MVFR CATEGORY IN A RAPID FASHION THIS MORNING
AND LOWER TO IFR IN THE AFTERNOON. WHILE THE PLUME OF THE BEST
MOISTURE WILL REMAIN SOUTHEAST OF THE I-71 CORRIDOR AND MAJORITY
OF TAF SITES...A PROLONGED PERIOD OF LIGHT PRECIPITATION WILL
OCCUR AND CIGS AT THE END OF THE VALID TAF ARE EXPECTED TO DIP TO
THE LIFR OR VLIFR.
AS FAR AS PTYPE GOES...SNOW WILL OCCUR IN THE MORNING AND
TRANSITION TO A FREEZING RAIN MIXED IN WITH SLEET BY THE
AFTERNOON. SOUNDINGS IN THE LATER AFTERNOON APPEAR TO HAVE THE TOP
OF THE MOISTURE COLUMN STUCK BETWEEN 0 AND -5 DEGREES AND LACKING
ANY DENDRITIC GROWTH...SUPPORTING SUB FREEZING RAINDROPS AND
DRIZZLE WHICH WILL FREEZE ON SURFACES.
TEMPERATURES MAY RISE TO ABOVE FREEZING IN THE LATE AFTERNOON AND
MORESO OVERNIGHT BUT STILL LINGER AROUND THE FREEZING MARK AND ADD
TO THE POSSIBILITY OF A PTYPE ISSUE. PRECIP THROUGH THE MAJORITY
OF THE NEXT 24 HOURS WILL BE LIGHT BUT CIGS ARE EXPECTED TO DROP
SIGNIFICANTLY GIVEN THE DEEP MOISTURE OVER THE REGION. WHILE A
CHANGEOVER TO -SN IS EXPECTED BEFORE THE PRECIP ENTIRELY
ENDS TONIGHT...VSBYS WILL REMAIN REDUCED BY MIST. DID NOT WANT TO
KEEP AN IFR VSBY IN SNOW WHEN THE MAIN FACTOR REDUCING THE VSBY
WAS THE MIST AND NOT PRECIP...EVEN IF SOME VERY LIGHT FLURRIES ARE
POSSIBLE THROUGH DAYBREAK. VERY LITTLE CHANGE TO THE FORECAST AND
MINUTE TIMING VARIABILITY IS FOUND AT ALL OF THE TAF FCSTS THIS
MORNING.
OUTLOOK...LIFR CIGS AND IFR VSBYS ARE LIKELY THROUGH MONDAY
MORNING...WITH MVFR CONDITIONS CONTINUING THROUGH MONDAY NIGHT.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR OHZ045-046-
051>056-060>065-070>074-077>082-088.
KY...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR KYZ089>100.
IN...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...CONIGLIO/SITES
NEAR TERM...HICKMAN/SITES
SHORT TERM...SITES
LONG TERM...AR
AVIATION...FRANKS
AREA FORECAST DISCUSSION
NWS TAUNTON MA
420 PM EST SUN DEC 8 2013
.SYNOPSIS...
COLD AND HIGH PRESSURE GRADUALLY LIFTS NORTH AND EAST AS LOW
PRESSURE LIFTS NORTH FROM THE CAROLINAS TONIGHT...ACROSS SOUTHERN
NEW ENGLAND DURING THE DAY MONDAY. MAINLY DRY...BUT UNSEASONABLY
COLD AND BLUSTERY WEATHER IS EXPECTED FOR THE REST OF THE UPCOMING
WORK WEEK. WE WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR A
PERIOD OF LIGHT SNOW ON TUESDAY...MAINLY SOUTH OF THE MASSACHUSETTS
TURNPIKE.
&&
.NEAR TERM /UNTIL 8 PM THIS EVENING/...
COLD AND DRY HIGH PRESSURE REMAINS RELATIVELY IN CONTROL. PER THE
LATEST SURFACE ANALYSIS...THE COLD-AIR DAMMING SIGNATURE IS WELL-
EVIDENT THROUGH THE MID-ATLANTIC ALONG THE EASTERN SPINE OF THE
APPALACHIAN MOUNTAINS. IT WILL LIKELY TAKE SOME TIME INTO THIS
EVENING FOR THE LOW PRESSURE CENTER EVOLVING OFF THE CAROLINA
COASTLINE TO BEGIN THE PROCESS OF WARM AIR NORTH AND ERODING THE
COLDER AIR IN PLACE.
FOLLOWING HRRR TRENDS...EXPECT THE HEAVIEST BANDING OF PRECIPITATION
TO REMAIN SOUTH OF THE REGION COLLOCATED WITH THE H85 THERMAL
GRADIENT AND REGION OF GREATEST MID-LEVEL CONVERGENCE. WILL KEEP
WITH A DRY FORECAST INTO SUNDOWN.
&&
.SHORT TERM /8 PM THIS EVENING THROUGH 6 PM MONDAY/...
AN OPEN-WAVE TROUGH ACROSS THE GREAT LAKES REGION HAS BEGUN TO
INTERACT WITH THE BROADER SUB-TROPICAL FLOW ACROSS THE EASTERN
CONUS. INFLECTION ALONG THE COLLOCATED TIGHT THERMAL GRADIENT HAS
SUBSEQUENTLY RESULTED IN A WEAK AREA OF LOW PRESSURE PRESENTLY OFF
THE MID-ATLANTIC WHICH WILL DRIFT NORTHEASTWARD ACROSS CAPE COD
BRINGING WITH IT A WINTRY MIX OF SNOW...SLEET...AND FREEZING RAIN
FOR SOUTHERN NEW ENGLAND DURING THE TIMEFRAME /ESPECIALLY THE MONDAY
MORNING COMMUTE/.
HAVE GREATER CONFIDENCE WITH COLDER SOLUTIONS. WITH BROAD AGREEMENT
AND RUN-TO-RUN CONTINUITY FROM THE ECMWF...PREFER THE MESO-NAM AND
WRF-MODEL SOLUTIONS WHICH CAPTURE THE COLD-AIR DAMMING PROCESSES
THROUGH THE CONNECTICUT RIVER VALLEY /SEE 1000-850 THICKNESSES/.
TRENDS ARE NOTEWORTHY WITHIN THE LATEST HRRR RUNS. BUT OVERALL THERE
IS STILL PLENTY OF UNCERTAINTY CONCERNING THERMAL PROFILES AND THE
ACCOMPANYING TRANSITION PROCESS OF WINTRY WEATHER TO PLAIN RAIN.
THAT BEING SAID...THERE IS A LOT TO CONSIDER. WITH H975 AGEOSTROPHIC
FLOW OUT OF THE INTERIOR NORTH WITH A WEAK LOW TRACKING ACROSS THE
CAPE...NOT EXPECTING EASTERLY ONSHORE FLOW NORTH OF THE LOW TO SCOUR
OUT INTERIOR SURFACE COLD AIR EFFECTIVELY. EXPECT PREVAILING
NORTHERLY COLD-AIR DRAINAGE FLOW...JAMMING UP THROUGHOUT INTERIOR
VALLEYS /ESPECIALLY THE CT RIVER VALLEY/. 2M FORECASTED TEMPERATURES
TAKEN MAINLY FROM MESO-NAM/WRF-MODEL SOLUTIONS. THOUGH THE EASTERLY
ONSHORE FLOW WILL RESULT IN A FASTER TRANSITION OF PRECIPITATION
TYPES ACROSS EAST COASTAL PLAIN IN THE MORNING...EXPECTING A WINTRY
MIX TO LAST LONGER ACROSS THE INTERIOR INTO THE MIDDAY AND POSSIBLY
THE AFTERNOON HOURS. UPSTREAM TRENDS ACROSS INTERIOR MID-ATLANTIC
SHOW THIS PROCESS ALREADY ONGOING WHICH ADD FURTHER CONFIDENCE THAT
COLD-AIR DAMMING OVER THE INTERIOR WILL BE A BIG ISSUE AS TO WINTER
WEATHER OUTCOMES.
PRECIPITATION AND SNOW/ICE AMOUNTS REMAIN A CHALLENGE...AND LIKELY
THERE ARE ALWAYS SURPRISES IN STORE WITH SYSTEMS SUCH AS THESE.
CONSIDERING THE AFOREMENTIONED SPATIAL AND TEMPORAL CHALLEGES IN THE
PRECIPITATION TRANSITION...IMPACTING ACCUMULATIONS AT THE SURFACE...
ANOTHER POINT OF CONCERN IS UPON PRECIPITATION AMOUNTS. EVALUATING
THE ATMOSPHERE...FORCING IS MAINLY WITHIN LOW-LEVELS WITH LITTLE
INDICATION OF DEEP-LAYER ASCENT ALBEIT SOME BROAD-SCALE DIFFLUENCE
ALOFT. YET SREF V-WIND ANOMALIES AT H85 ARE +2 STANDARD-DEVIATIONS
AND NOTING UPSTREAM TRENDS OVER THE MID-ATLANTIC...THERE IS THE
DISTINCT POSSIBILITY FOR A MESO-SCALE BAND OF SNOW ACROSS SOUTHERN
NEW ENGLAND COLLOCATED WITH THE TIGHT H85 THERMAL GRADIENT WHERE
STRONG LOW-LEVEL CONVERGENCE IS MODELED TO LIFT THROUGH BETTER SNOW-
GROWTH REGIONS. THERE IS SOME SIGNAL WITHIN NEAR-TERM MESOSCALE
SOLUTIONS...ALBEIT CHAOTIC. IT IS ENTIRELY PLAUSIBLE TO SEE AREAS IN
PROXIMITY TO THE SOUTH-COAST OF SEEING A COUPLE OF INCHES OF SNOW IN
A SHORT PERIOD OF TIME DURING THE EARLY ONSET BEFORE TRANSITIONING
TO RAIN.
AS SUCH...WILL TAKE 1-2 INCH ACCUMULATIONS DOWN TO THE SOUTH-COAST.
WILL HAVE 2-4 INCHES FOR PORTIONS OF NORTH AND WEST MA AND SOUTHERN
NH. ICE ACCUMULATIONS UP TO A TENTH OF AN INCH EXPECTED ALONG AND
EAST OF THE EASTERN COASTAL PLAIN...EAST OF THE I-95/I-495 BELTWAY.
TOTAL LIQUID PRECIPITATION AMOUNTS AROUND 0.4 INCHES WITH THE
HEAVIEST AMOUNTS JUST OFF THE SOUTH-COAST.
EXPECT ACCUMULATIONS TO BEGIN THIS EVENING AND CONTINUE THROUGH THE
MORNING COMMUTE. WILL SEE A GRADUAL TRANSITION OF FROZEN P-TYPES
BACK INTO THE INTERIOR BEGINNING AROUND 6-8 AM...WITH LOCATIONS
ACROSS WESTERN AND NORTHERN MA AND SOUTHERN NH SEEING THE LONGEST
PERIOD OF A WINTRY MIX....EAST-COAST TRANSITIONING QUICKEST. HAVE
LENGTHENED THE WINTER- WEATHER ADVISORY FOR HARTFORD COUNTY CT
WITH THE EXPECTATION OF COLD-AIR DRAINAGE PROCESSES. IMPACTS IN
THE WINTER WEATHER ADVISORY...BUT IN BREVITY...EXPECT A MESSY
MONDAY MORNING COMMUTE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* PERIOD OF LIGHT SNOW POSSIBLE SOUTH OF MA PIKE ON TUE
* MAINLY DRY AND UNSEASONABLY COLD WED THROUGH FRI
* LOW CONFIDENCE FORECAST NEXT WEEKEND
DETAILS...
MONDAY NIGHT...
OTHER THAN PERHAPS A LEFT OVER SPOT SHOWER IN THE EARLY EVENING...
DRY WEATHER EXPECTED. A COLD FRONT SWINGS THROUGH THE REGION EARLY
IN THE EVENING. TEMPS WILL ACTUALLY RISE ABOVE FREEZING ACROSS
PORTIONS OF THE INTERIOR THAT HAVE BEEN JAMMED IN SHALLOW COLD AIR
DURING THE DAY MONDAY. THE REASON FOR THIS IS THAT WARMER MID
LEVEL AIR WILL BE TEMPORARILY MIXED DOWN...AS WINDS SHIFT TO THE
WEST. THIS SHOULD ALLOW ANY LEFTOVER ICY CONDITIONS ON ROADWAYS TO
MELT. COLDER AIR WILL FINALLY BEGIN WORKING BACK INTO THE REGION
OVERNIGHT...WITH LOWS BY DAYBREAK BACK INTO THE 20S ACROSS THE
INTERIOR. THE COASTAL PLAIN SHOULD ONLY SEE LOWS REACH THE LOWER
TO MIDDLE 30S.
TUESDAY...
THE MAIN CONCERN IS THE CHANCES FOR A PERIOD OF LIGHT SNOW ON
TUESDAY...MAINLY SOUTH OF THE MA TURNPIKE. A WEAK WAVE OF LOW
PRESSURE WILL BE PASSING WELL TO OUR SOUTH...BUT AN APPROACHING
SHORTWAVE BACKS THE UPPER LEVEL FLOW. IT PLACES US UNDERNEATH A
POTENT JET STREAK WHICH RESULTS IN A PERIOD OF DECENT MID LEVEL
LIFT. WILL BE FIGHTING LOW LEVEL DRY AIR SO NOT EXPECTING A LOT OF
PRECIP...BUT A PERIOD OF LIGHT SNOW IS STILL POSSIBLE SOUTH OF MA
TURNPIKE ESPECIALLY NEAR THE SOUTH COAST. PERHAPS ITS MILD ENOUGH
FOR MIXED PRECIP AT THE ONSET ACROSS CAPE/ISLANDS...BUT SHOULD
TURN OVER TO ALL LIGHT SNOW. WE MAY EVEN SEE A COATING TO PERHAPS
1 INCH IN A FEW LOCATIONS. THERE IS A LOW PROBABILITY OF A BIT
MORE SNOW NEAR THE SOUTH COAST...BUT MOST GUIDANCE DOES NOT
SUPPORT THAT AT THIS TIME.
WEDNESDAY THROUGH FRIDAY...
NORTHWEST FLOW ALOFT WILL RESULT IN UNSEASONABLY COLD WEATHER FOR
SOUTHERN NEW ENGLAND. THERE ARE SOME MODEL DISCREPANCIES ON THE
TIMING OF REINFORCING SHOTS OF COLD AIR...HENCE UNCERTAINTIES ON
WHICH DAY WILL BE THE COLDEST. MAINLY DRY WEATHER DOMINATES OVER
THIS TIME PERIOD...BUT CAN/T RULE OUT A BRIEF PASSING FLURRY/SNOW
SHOWER WITH SOME MOISTURE STARVED NORTHERN STREAM ENERGY/FRONTAL
PASSAGES. IT ALSO WILL BE WINDY AT TIMES...SO IT CERTAINLY WILL
FEEL WINTERLIKE.
SATURDAY AND SUNDAY...
FORECAST CONFIDENCE IS VERY LOW OVER THIS TIME. THE ONE THING WILL
HAVE TO WATCH NEXT WEEKEND IS THE TRACK A WAVE OF LOW PRESSURE TO
OUR SOUTH. MOST MODELS SUGGEST THAT THE SYSTEM WILL PASS FAR
ENOUGH SOUTH TO SPARE OUR REGION OF SIGNIFICANT PRECIP.
HOWEVER...SOME MODELS SUGGEST THE LARGE HIGH TO OUR NORTH MAY
EVENTUALLY RESULT IN ONSHORE FLOW...BRINGING THE POTENTIAL FOR
SOME LIGHT WINTRY PRECIPITATION. OTHER GUIDANCE SUGGESTS SOUTHWEST
FLOW ALOFT MAY RESULT IN SOME OVER RUNNING PRECIPITATION. ALL IN
ALL...VERY LOW CONFIDENT FORECAST FOR NEXT WEEKEND.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
21Z UPDATE...
NEAR-TERM /THROUGH MONDAY/...HIGH CONFIDENCE ON TRENDS. MODERATE
CONFIDENCE ON TIMING OF PRECIPITATION TYPE SPECIFICS AND CIG/VSBY
IMPACTS.
CIGS LOWERING FROM LOW-END VFR TO MVFR/IFR. INITIAL ONSET OF -SN
WITH IFR VSBYS...TRANSITIONING TO -PL/UP/FZRA THEN TO PLAIN RAIN
BY MORNING INTO THE AFTERNOON. EXPECT QUICKEST TRANSITION ALONG
EAST-COAST TERMINALS...MORE GRADUAL ACROSS THE INTERIOR WITH THE
WINTRY MIX HOLDING ON LONGER OVER TERMINALS WITHIN VALLEYS. WITH
-SN/PL WENT WITH IFR VSBYS...MVFR VSBYS FOR -FZRA/RA.
NORTHERLY FLOW GRADUALLY VEERING EASTERLY THROUGH THE PERIOD WITH
GUSTS UP TO AROUND 20 KTS ESPECIALLY ALONG THE COAST. THOUGH EXPECT
IN SHELTERED VALLEYS A LIGHT NORTHERLY FLOW TO PREVAIL.
CONDITIONS BEGIN TO IMPROVE INTO MONDAY NIGHT.
KBOS TAF...HIGH CONFIDENCE IN TRENDS. LOW CONFIDENCE IN TIMING OF
PRECIPITATION TRANSITIONS. EXPECTING -SN TO QUICKLY TRANSITION TO
-RA DURING THE MORNING WITH ONSHORE EASTERLY FLOW.
KBDL TAF...HIGH CONFIDENCE IN TRENDS. LOW CONFIDENCE IN TIMING OF
PRECIPITATION TRANSITIONS. -SN WILL GRADUALLY TRANSITION TO A
WINTRY MIX...BUT THAT MIX MAY HOLD LONGER WITH SHALLOW COLD AIR
BELOW-FREEZING OVER THE TERMINAL. LIGHT NORTHERLY FLOW.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. LEFT OVER MVFR-IFR
CONDITIONS EARLY IN THE EVENING IMPROVE TO VFR BEHIND A COLD FRONT.
TUESDAY...LOW CONFIDENCE. A PERIOD OF MVFR-IFR CONDITIONS POSSIBLE
SOUTH OF THE MA TURNPIKE IN A ROUND OF LIGHT SNOW. OTHERWISE...VFR
CONDITIONS FOR THE REST OF THE TIME.
WEDNESDAY THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE. VFR
CONDITIONS DOMINATE WITH GUSTY WNW WINDS AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /THROUGH MONDAY/...HIGH CONFIDENCE.
NORTHERLY WINDS OVER THE WATERS WILL VEER EAST-SOUTHEASTERLY WITH
TIME GUSTING 25 TO 30 KTS DURING THE DAY MONDAY AS AN AREA OF LOW
PRESSURE CROSSES INTO SOUTHERN NEW ENGLAND. WITH THE LOW/S PASSAGE
EXPECT WINDS TO BACK MORE SOUTHERLY.
PROLONGED PERIOD OF FETCH WILL RESULT IN SEAS OF 6 TO 8 FEET
ACROSS THE OUTER WATERS IMPACTING THE EAST- FACING ATLANTIC
BEACHES. SMALL CRAFT ADVISORIES IN EFFECT FOR ALL LOCATIONS EXCEPT
INNER BAYS.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...HIGH CONFIDENCE.
THE GENERAL IDEA IS THAT THE PASSAGE OF A COUPLE OF STRONG COLD
FRONTS WILL RESULT IN PERSISTENT WEST TO NORTHWEST WINDS OVER THIS
TIME. GIVEN THE STRONG COLD ADVECTION OVER THE WATERS...SCA WIND
GUSTS ARE EXPECTED OVER MUCH OF THIS TIME PERIOD OVER THE OPEN
WATERS. WE MAY EVEN SEE A BRIEF GALE FOR A TIME ON WEDNESDAY. THERE
ALSO WILL BE LULLS IN THE WIND...BUT TIMING THAT THIS FAR OUT IS
IMPOSSIBLE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
MONDAY FOR CTZ002>004.
MA...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
MONDAY FOR MAZ013-017.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 1 PM EST
MONDAY FOR MAZ002>005-008>012-014-026.
NH...NONE.
RI...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
MONDAY FOR RIZ001>004-006.
MARINE...SMALL CRAFT ADVISORY FROM 5 AM TO 1 PM EST MONDAY FOR
ANZ231>234.
SMALL CRAFT ADVISORY FROM 3 AM TO 6 PM EST MONDAY FOR ANZ235-
237-254>256.
SMALL CRAFT ADVISORY FROM 7 AM TO 6 PM EST MONDAY FOR ANZ250.
SMALL CRAFT ADVISORY FROM 7 AM TO 1 PM EST MONDAY FOR ANZ251.
&&
$$
SYNOPSIS...FRANK/SIPPRELL
NEAR TERM...SIPPRELL
SHORT TERM...SIPPRELL
LONG TERM...FRANK
AVIATION...FRANK/SIPPRELL
MARINE...FRANK/SIPPRELL
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
103 PM EST SUN DEC 8 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE INTO NEW ENGLAND BY THIS EVENING. A LOW
PRESSURE SYSTEM WILL MOVE THROUGH THE GREAT LAKES REGION THROUGH
TODAY AND MONDAY, DRAGGING A COLD FRONT THROUGH OUR AREA LATE
MONDAY. MEANWHILE, A LOW PRESSURE SYSTEM WILL DEVELOP AND MOVE UP
ALONG THE MIDDLE ATLANTIC COAST ON MONDAY. A SECONDARY FRONT WILL
MOVE THROUGH THE REGION LATE TUESDAY INTO WEDNESDAY. HIGH PRESSURE
WILL THEN BUILD INTO THE REGION FROM THE WEST ON WEDNESDAY BEFORE
SHIFTING EAST OF THE AREA AT THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN EXTENSIVE SURFACE AND UPPER AIR ANALYSIS REVEALS RATHER ROBUST
LOW-LEVEL WAA ACROSS PORTIONS OF THE MID ATLANTIC. TO THE NORTH OF
THIS ZONE, A TIGHTENING AREA OF WEST TO EAST ORIENTATED FRONTOGENETIC
FORCING IS OCCURRING. THIS FORCING IS SEEN IN THE RADAR DATA AS A
BANDED FEATURE ACROSS NORTHERN MARYLAND TO PORTIONS OF SOUTHERN
NEW JERSEY. THERE APPEARS TO BE SOME SLANTWISE INSTABILITY PLAYING
A ROLE ALONG WITH SIGNIFICANT ISENTROPIC UPGLIDE COMBINING WITH
THE SNOW GROWTH REGION. THIS IS PRODUCING SNOWFALL RATES OF 1-2
INCHES PER HOUR WITH SOME AREAS UNDER THE BAND REPORTING 4-4.5
INCHES OF SNOW ALREADY. THE VISIBLE SATELLITE IMAGERY HAS SHOWN
SOME CONVECTIVE NATURE AT TIMES TO THE CLOUD FEATURES WITH THIS
BAND. BASED ON THIS AND ALSO RADAR TRENDS, A WINTER STORM WARNING
WAS ISSUED FOR THE COUNTIES BEING AFFECT BY THE BANDING. THE
ADVISORY WAS EXPANDED TO THE REST OF THE AREA AS ROADWAYS WILL
BECOME OR ALREADY HAVE BECOME HAZARDOUS.
THE LATEST HRRR HAS THIS FEATURE PLACED RATHER WELL SO FAR AND IT
CONTINUES TO SLIDE IT NORTHEASTWARD ACROSS PHILADELPHIA AND
PORTIONS OF SOUTHERN NEW JERSEY. FARTHER NORTH, WEAKER FORCING SO
FAR AND DRIER AIR IS PREVENTING THE SNOW FROM SHIFTING NORTHWARD.
THE DRY AIR IS EXPECTED TO GRADUALLY GIVE WAY DURING THE REST OF
THE AFTERNOON, ALLOWING SNOW TO BREAK OUT FARTHER TO THE NORTH.
THE GRIDS WERE UPDATED TO INCREASE SNOW AMOUNTS ESPECIALLY FOR
THE AREA BEING AFFECTED BY THE BANDING FEATURE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
HOWEVER, AS WAA INCREASES THRU THE NIGHT, THE PRECIP WILL BEGIN TO
MIX AND EVENTUALLY CHANGE TO ALL RAIN FROM SE TO NW. THE GFS IS THE
WARMEST/FASTEST MDL WITH THIS TRANSITION. THE NAM/WRF AND ECMWF ARE
A BIT SLOWER BUT STILL HAVE THE CHANGEOVER REACHING THE I-95
CORRIDOR SHORTLY AFTER MIDNIGHT. FURTHER AND W, THE WINTRY PRECIP
WILL HANG ON LONGER. CURRENT THINKING IS THE GFS IS TOO WARM/TOO
QUICK WITH THE TRANSITION.
IT IS STILL PSBL THERE COULD BE A PD OF FZRA ALG THE I-95 CORRIDOR,
BUT CONFIDENCE IS LOW ON THIS OCCURRENCE SO NO HEADLINES ARE BEING
ISSUED FOR NOW. IF THE GFS IS CORRECT, THEY WILL LIKELY NOT BE
NEEDED. IF MORE SLEET OCCURS IN THE TRANSITION, THEY MAY NOT BE
NEEDED EITHER. BY MON MRNG, ALL BUT THE FAR N AND W SHOULD BE
RAIN.
TEMPS WILL RISE OVERNIGHT AS THE WAA KICKS IN. THIS IS DEFINITELY A
TRICKY TEMP DAY (AND NIGHT) AND A COUPLE OF DEGREES MAKES A WORLD OF
DIFFERENCE!
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
THINGS SHOULD BEGIN TO WIND DOWN BY MONDAY MORNING WITH JUST A FEW
ISSUES LEFT LINGERING ACROSS THE POCONOS IN TERMS OF ICING, THOUGH
WE MIGHT BE A COUPLE HOURS TOO LONG ON THIS. OTHERWISE RAIN WILL
CONTINUE TO OVERSPREAD FROM THE SOUTH-SOUTHWEST AS THE COASTAL WAVE
CONTINUES ITS NORTHWARD PROGRESS PASSING JUST OFF THE DELMARVA
COAST. A WEAK COLD FRONT WILL THEN PUSH IN FROM THE WEST AND
EFFECTIVELY PUT AN END TO PRECIPITATION BUT IN DOING SO COLDER AIR
BEGINS TO FILTER BACK INTO THE REGION.
MODELS CONTINUE TO SHOW A DISCONTINUITY WITH EACH OTHER IN TERMS OF
THE FINAL WAVE ON TUESDAY...DOES IT SKIRT BY TO OUR SOUTH OR HAVE
ENOUGH LATITUDE TO BRUSH BY OVERHEAD. UPPER LEVEL SUPPORT IN TERMS
OF THE RIGHT ENTRANCE TO THE STRONG JET AND WEAK Q-VEC CONVERGENCE
COUPLED WITH WEAK FGEN IN THE 700-500MB LAYER, SHOULD ALLOW FOR SOME
MORE MOISTURE TO BE SQUEEZED OUT ACROSS AT LEAST THE SOUTHERN HALF
OF THE CWA TUESDAY AFTERNOON. THERMAL PROFILES WILL BE CONDUCIVE FOR
ALL SNOW TO FALL THOUGH THE ONE MAJOR QUESTION BECOMES HOW MUCH
ENERGY IS STILL LEFT IN THE MID-LEVELS. BY TUESDAY THE MID-LEVEL
ENERGY BECOMES VERY STRUNG OUT AND MAY HAVE GIVEN ALL IT CAN SO
ONLY TIME WILL TELL IN THE AFTERMATH OF TONIGHTS SYSTEM TO SEE IF IF
CAN RECOVER. SPEAKING OF SNOWFALL, NOT EXPECTING MUCH IN THE WAY OF
ACCUMULATION THOUGH SOME OF THE MODELS ARE TRYING TO SHOW A QUICK
BURST TUESDAY AFTERNOON WITH DECENT DENDRITIC GROWTH POSSIBLE WITH
UPWARDS OF AN INCH IN SPOTS...MOST SOUTH AND EAST OF PHILLY.
WITH THE FINAL WAVE GONE, HIGH PRESSURE WORKS BACK IN ON WEDNESDAY
AND TEMPERATURES PLUMMET TO WELL BELOW SEASONAL AVERAGES...THROUGH
AT LEAST THE END OF THE WORK WEEK. A SLIGHT MODERATION IS EXPECTED
BY SATURDAY AS THE FLOW BEGINS TO VEER SLIGHTLY TOWARDS THE
WEST-SOUTHWEST. THE NEXT POTENTIAL SYSTEM LOOKS TO SKIRT BY THE
COAST SATURDAY NIGHT INTO SUNDAY THROWING SOME MOISTURE BACK ACROSS
THE REGION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THIS AFTERNOON...A BAND OF HEAVY SNOW WILL IMPACT KILG TO KPHL AND
KPNE ESPECIALLY FOR AWHILE. THIS WILL PRODUCE MVFR TO IFR
CONDITIONS WITH SNOWFALL RATES AROUND AN INCH PER HOUR. THIS BAND
SHOULD TRANSLATE TO THE NORTHEAST THROUGH THE AFTERNOON WITH
PERHAPS SOME LESSENING OF THE SNOW INTENSITY POSSIBLE LATER.
ELSEWHERE, SNOW IS EXPECTED TO ARRIVE NORTHWARD WITH THE ARRIVAL
LAST AT KABE AND KTTN. THE SNOW MAY START TO MIX WITH SOME SLEET
NEAR KPHL ON SOUTH AND EAST TOWARD EARLY EVENING. NORTH TO
NORTHEAST WINDS 5-8 KNOTS.
TONIGHT...A TRANSITION OF THE PRECIPITATION IS EXPECTED FROM
SOUTHEAST TO NORTHWEST, WITH SNOW AND SLEET CHANGING TO FREEZING
RAIN AND RAIN. KABE AND KRDG WILL HANG ONTO THE FROZEN/FREEZING
PRECIPITATION THE LONGEST, WITH KMIV AND KACY HAVING ALL RAIN SOONER.
MVFR AND TO EVEN IFR CONDITIONS /ESPECIALLY CEILINGS/ ARE EXPECTED.
NORTHEAST WINDS GENERALLY AROUND 5 KNOTS, HOWEVER BECOMING
EAST-SOUTHEAST MAINLY AT KACY OVERNIGHT.
OUTLOOK...
MONDAY...STILL EXPECTING AN MVFR/IFR DAY AS RAIN CONTINUES TO
OVERSPREAD FROM THE SOUTH-SOUTHWEST. A COASTAL LOW PRESSURE WILL
PASS BY HEADING TOWARDS NEW ENGLAND AND MAY HELP TO KEEP A
PREDOMINANT EASTERLY FLOW ACROSS THE REGION THROUGH THE MORNING
HOURS AND THEN AS THE LOW MOVES AWAY WE BACK TOWARDS THE WEST. RAIN
SHOULD BEGIN TO COME TO AN END DURING THE EVENING HOURS.
TUESDAY...ONE FINAL WAVE OF LOW PRESSURE MAY IMPACT THE REGION
DURING THE DAY PROVIDING MVFR/IFR SNOW. NOT QUITE SURE HOW FAR
INLAND THE PRECIPITATION WILL FALL BUT HIGHER CONFIDENCE AT THIS
POINT IS FROM MIV AND ACY...MAYBE THE I-95 CORRIDOR. OTHERWISE WE
WILL BE VFR.
WEDNESDAY - THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL SLIDE INTO NEW ENGLAND THROUGH TONIGHT.
MEANWHILE, LOW PRESSURE WILL TRACK UP THE OHIO VALLEY WITH A
SECONDARY WEAKER LOW DEVELOP NEAR THE MID ATLANTIC COAST. AS THIS
OCCURS, THE NORTHEASTERLY WIND WILL INCREASE SOME AND THEN TURN
EASTERLY TONIGHT ESPECIALLY ACROSS THE NORTHERN ZONES. BASED ON THE
FORECAST SOUNDINGS FROM THE NAM/GFS AND ECMWF, WE OPTED TO ISSUE A
SMALL CRAFT ADVISORY FOR OUR TWO NORTHERN ZONES STARTING THIS
EVENING AND GOING THROUGH 11Z MONDAY AT THIS POINT. WE WILL
REEVALUATE THIS LATER TODAY. WE ALSO EXTENDED THE ADVISORY FOR OUR
CENTRAL AND SOUTHERN OCEAN ZONES UNTIL 05Z TONIGHT AFTER
COLLABORATING WITH WFO AKQ. WE HELD OFF ON AN ADVISORY FOR DELAWARE
BAY AS THE GREATER FLOW LOOKS TO BE ACROSS THE OCEAN. SEAS WILL BE
NEAR 5 FEET THROUGH TONIGHT GIVEN THE FLOW INCREASING SOME AND
TURNING MORE NORTHEAST AND EAST.
OUTLOOK...
MONDAY...LINGERING SMALL CRAFT ISSUES POSSIBLE AS THE COASTAL WAVE
PULLS FURTHER NORTH WITH SEAS AND WINDS BEGINNING TO RELAX BY LATE
IN THE DAY.
TUESDAY AND WEDNESDAY...A FAIRLY TIGHT GRADIENT WILL EXIST FOR THE
TUESDAY THROUGH WEDNESDAY TIME FRAME WITH WINDS PICKING UP OUT OF
THE WEST OR NORTHWEST. WE COULD NEAR GALES ACROSS THE NORTH FOR A
BRIEF TIME PERIOD WEDNESDAY MORNING BUT CONFIDENCE IS RATHER LOW
RIGHT NOW. CONFIDENCE IS HIGH THAT A SMALL CRAFT WILL BE NEEDED FOR
THAT TIME FRAME.
THURSDAY...WINDS AND SEAS WILL SUBSIDE BELOW SMALL CRAFT ADVISORY
LEVELS AS HIGH PRESSURE BUILDS ACROSS THE REGION.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 5 AM EST MONDAY FOR PAZ060>062.
WINTER WEATHER ADVISORY UNTIL 3 AM EST MONDAY FOR PAZ101-
103>106.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
MONDAY FOR PAZ054-055.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR PAZ070-071-
102.
NJ...WINTER WEATHER ADVISORY UNTIL 5 AM EST MONDAY FOR NJZ007-008.
WINTER WEATHER ADVISORY UNTIL 3 AM EST MONDAY FOR NJZ009.
WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR
NJZ021>023.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
MONDAY FOR NJZ001.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR NJZ016>020-
027.
WINTER WEATHER ADVISORY UNTIL 1 AM EST MONDAY FOR NJZ010-012-
013-015.
DE...WINTER WEATHER ADVISORY UNTIL 9 PM EST THIS EVENING FOR DEZ002-
003.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR DEZ001.
MD...WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR MDZ008.
WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ012-
015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ452>455.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 AM EST MONDAY
FOR ANZ450-451.
&&
$$
SYNOPSIS...HEAVENER/MEOLA
NEAR TERM...GORSE
SHORT TERM...NIERENBERG
LONG TERM...HEAVENER
AVIATION...GORSE/HEAVENER
MARINE...GORSE/HEAVENER/MEOLA
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
1139 AM EST SUN DEC 8 2013
.SYNOPSIS...
HIGH PRESSURE WILL SLIDE INTO NEW ENGLAND BY THIS EVENING. A LOW
PRESSURE SYSTEM WILL MOVE THROUGH THE GREAT LAKES REGION THROUGH
TODAY AND MONDAY, DRAGGING A COLD FRONT THROUGH OUR AREA LATE
MONDAY. MEANWHILE, A LOW PRESSURE SYSTEM WILL DEVELOP AND MOVE UP
ALONG THE MIDDLE ATLANTIC COAST ON MONDAY. A SECONDARY FRONT WILL
MOVE THROUGH THE REGION LATE TUESDAY INTO WEDNESDAY. HIGH PRESSURE
WILL THEN BUILD INTO THE REGION FROM THE WEST ON WEDNESDAY BEFORE
SHIFTING EAST OF THE AREA AT THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AN EXTENSIVE SURFACE AND UPPER AIR ANALYSIS THIS MORNING REVEALS
RATHER ROBUST LOW-LEVEL WAA ACROSS PORTIONS OF THE MID ATLANTIC.
TO THE NORTH OF THIS ZONE, THERE APPEARS TO BE A TIGHTENING AREA
OF WEST TO EAST FRONTOGENETIC FORCING. THIS FORCING IS SEEN IN THE
RADAR DATA AS A BANDED FEATURE ACROSS NORTHERN MARYLAND AND IT IS
NOW MOVING ACROSS NORTHERN DELAWARE AND SOUTHWESTERN NEW JERSEY.
THE LATEST HRRR HAS THIS FEATURE PLACED WELL SO FAR AND IT SLIDES
IT NORTHEASTWARD ACROSS PHILADELPHIA AND THEN ACROSS PORTIONS OF
SOUTHERN NEW JERSEY. THERE ARE REPORTS OF MODERATE TO HEAVY SNOW
OCCURRING WITH THIS BANDED FEATURE, WHICH IS RESULTING IN MUCH
MORE EFFICIENT ACCUMULATIONS.
AS A RESULT, WE EXPANDED THE WINTER WEATHER ADVISORY TO THE EAST
ANOTHER TIER OF ZONES. IT MAY NEED TO BE EXTENDED TO THE COAST,
BUT EVENTUAL WARMING ALOFT AND FROM THE OCEAN INFLUENCE SHOULD
KEEP SNOW ACCUMULATIONS LOWERED TOWARD THE COAST. THIS IS OF LOWER
CONFIDENCE HOWEVER. WE ALSO ADDED IN LIGHT ICING INTO THE NEW
ADVISORY PORTION AS SOUNDINGS DO SHOW A POTENTIAL WINDOW OF
OPPORTUNITY THIS EVENING DURING THE TRANSITION PERIOD.
THE GRIDS ARE BEING UPDATED TO INCREASE SNOW AMOUNTS SOME
ESPECIALLY FOR THE AREA BEING AFFECTED BY THE BANDING FEATURE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
HOWEVER, AS WAA INCREASES THRU THE NIGHT, THE PRECIP WILL BEGIN TO
MIX AND EVENTUALLY CHANGE TO ALL RAIN FROM SE TO NW. THE GFS IS THE
WARMEST/FASTEST MDL WITH THIS TRANSITION. THE NAM/WRF AND ECMWF ARE
A BIT SLOWER BUT STILL HAVE THE CHANGEOVER REACHING THE I-95
CORRIDOR SHORTLY AFTER MIDNIGHT. FURTHER AND W, THE WINTRY PRECIP
WILL HANG ON LONGER. CURRENT THINKING IS THE GFS IS TOO WARM/TOO
QUICK WITH THE TRANSITION.
IT IS STILL PSBL THERE COULD BE A PD OF FZRA ALG THE I-95 CORRIDOR,
BUT CONFIDENCE IS LOW ON THIS OCCURRENCE SO NO HEADLINES ARE BEING
ISSUED FOR NOW. IF THE GFS IS CORRECT, THEY WILL LIKELY NOT BE
NEEDED. IF MORE SLEET OCCURS IN THE TRANSITION, THEY MAY NOT BE
NEEDED EITHER. BY MON MRNG, ALL BUT THE FAR N AND W SHOULD BE
RAIN.
TEMPS WILL RISE OVERNIGHT AS THE WAA KICKS IN. THIS IS DEFINITELY A
TRICKY TEMP DAY (AND NIGHT) AND A COUPLE OF DEGREES MAKES A WORLD OF
DIFFERENCE!
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
THINGS SHOULD BEGIN TO WIND DOWN BY MONDAY MORNING WITH JUST A FEW
ISSUES LEFT LINGERING ACROSS THE POCONOS IN TERMS OF ICING, THOUGH
WE MIGHT BE A COUPLE HOURS TOO LONG ON THIS. OTHERWISE RAIN WILL
CONTINUE TO OVERSPREAD FROM THE SOUTH-SOUTHWEST AS THE COASTAL WAVE
CONTINUES ITS NORTHWARD PROGRESS PASSING JUST OFF THE DELMARVA
COAST. A WEAK COLD FRONT WILL THEN PUSH IN FROM THE WEST AND
EFFECTIVELY PUT AN END TO PRECIPITATION BUT IN DOING SO COLDER AIR
BEGINS TO FILTER BACK INTO THE REGION.
MODELS CONTINUE TO SHOW A DISCONTINUITY WITH EACH OTHER IN TERMS OF
THE FINAL WAVE ON TUESDAY...DOES IT SKIRT BY TO OUR SOUTH OR HAVE
ENOUGH LATITUDE TO BRUSH BY OVERHEAD. UPPER LEVEL SUPPORT IN TERMS
OF THE RIGHT ENTRANCE TO THE STRONG JET AND WEAK Q-VEC CONVERGENCE
COUPLED WITH WEAK FGEN IN THE 700-500MB LAYER, SHOULD ALLOW FOR SOME
MORE MOISTURE TO BE SQUEEZED OUT ACROSS AT LEAST THE SOUTHERN HALF
OF THE CWA TUESDAY AFTERNOON. THERMAL PROFILES WILL BE CONDUCIVE FOR
ALL SNOW TO FALL THOUGH THE ONE MAJOR QUESTION BECOMES HOW MUCH
ENERGY IS STILL LEFT IN THE MID-LEVELS. BY TUESDAY THE MID-LEVEL
ENERGY BECOMES VERY STRUNG OUT AND MAY HAVE GIVEN ALL IT CAN SO
ONLY TIME WILL TELL IN THE AFTERMATH OF TONIGHTS SYSTEM TO SEE IF IF
CAN RECOVER. SPEAKING OF SNOWFALL, NOT EXPECTING MUCH IN THE WAY OF
ACCUMULATION THOUGH SOME OF THE MODELS ARE TRYING TO SHOW A QUICK
BURST TUESDAY AFTERNOON WITH DECENT DENDRITIC GROWTH POSSIBLE WITH
UPWARDS OF AN INCH IN SPOTS...MOST SOUTH AND EAST OF PHILLY.
WITH THE FINAL WAVE GONE, HIGH PRESSURE WORKS BACK IN ON WEDNESDAY
AND TEMPERATURES PLUMMET TO WELL BELOW SEASONAL AVERAGES...THROUGH
AT LEAST THE END OF THE WORK WEEK. A SLIGHT MODERATION IS EXPECTED
BY SATURDAY AS THE FLOW BEGINS TO VEER SLIGHTLY TOWARDS THE
WEST-SOUTHWEST. THE NEXT POTENTIAL SYSTEM LOOKS TO SKIRT BY THE
COAST SATURDAY NIGHT INTO SUNDAY THROWING SOME MOISTURE BACK ACROSS
THE REGION.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
REST OF TODAY...A BAND OF MODERATE TO HEAVY SNOW WILL IMPACT KILG
TO KPHL ESPECIALLY FOR AWHILE. THIS WILL PRODUCE MVFR TO IFR
CONDITIONS WITH SNOWFALL RATES NEARING AN INCH PER HOUR. THIS BAND
SHOULD TRANSLATE TO THE NORTHEAST THROUGH THE AFTERNOON WITH
PERHAPS SOME LESSENING OF THE SNOW INTENSITY POSSIBLE LATER.
ELSEWHERE, SNOW IS EXPECTED TO ARRIVE NORTHWARD WITH THE ARRIVAL
LAST AT KABE AND KTTN. THE SNOW MAY START TO MIX WITH SOME SLEET
NEAR KPHL ON SOUTH AND EAST TOWARD EARLY EVENING. NORTH TO NORTHEAST
WINDS 5-8 KNOTS.
TONIGHT...A TRANSITION OF THE PRECIPITATION IS EXPECTED FROM
SOUTHEAST TO NORTHWEST, WITH SNOW AND SLEET CHANGING TO FREEZING
RAIN AND RAIN. KABE AND KRDG WILL HANG ONTO THE FROZEN/FREEZING
PRECIPITATION THE LONGEST, WITH KMIV AND KACY HAVING ALL RAIN SOONER.
MVFR AND TO EVEN IFR CONDITIONS /ESPECIALLY CEILINGS/ ARE EXPECTED.
NORTHEAST WINDS GENERALLY AROUND 5 KNOTS, HOWEVER BECOMING
EAST-SOUTHEAST MAINLY AT KACY OVERNIGHT.
OUTLOOK...
MONDAY...STILL EXPECTING AN MVFR/IFR DAY AS RAIN CONTINUES TO
OVERSPREAD FROM THE SOUTH-SOUTHWEST. A COASTAL LOW PRESSURE WILL
PASS BY HEADING TOWARDS NEW ENGLAND AND MAY HELP TO KEEP A
PREDOMINANT EASTERLY FLOW ACROSS THE REGION THROUGH THE MORNING
HOURS AND THEN AS THE LOW MOVES AWAY WE BACK TOWARDS THE WEST. RAIN
SHOULD BEGIN TO COME TO AN END DURING THE EVENING HOURS.
TUESDAY...ONE FINAL WAVE OF LOW PRESSURE MAY IMPACT THE REGION
DURING THE DAY PROVIDING MVFR/IFR SNOW. NOT QUITE SURE HOW FAR
INLAND THE PRECIPITATION WILL FALL BUT HIGHER CONFIDENCE AT THIS
POINT IS FROM MIV AND ACY...MAYBE THE I-95 CORRIDOR. OTHERWISE WE
WILL BE VFR.
WEDNESDAY - THURSDAY...VFR.
&&
.MARINE...
HIGH PRESSURE WILL SLIDE INTO NEW ENGLAND THROUGH TONIGHT.
MEANWHILE, LOW PRESSURE WILL TRACK UP THE OHIO VALLEY WITH A
SECONDARY WEAKER LOW DEVELOP NEAR THE MID ATLANTIC COAST. AS THIS
OCCURS, THE NORTHEASTERLY WIND WILL INCREASE SOME AND THEN TURN
EASTERLY TONIGHT ESPECIALLY ACROSS THE NORTHERN ZONES. BASED ON THE
FORECAST SOUNDINGS FROM THE NAM/GFS AND ECMWF, WE OPTED TO ISSUE A
SMALL CRAFT ADVISORY FOR OUR TWO NORTHERN ZONES STARTING THIS
EVENING AND GOING THROUGH 11Z MONDAY AT THIS POINT. WE WILL
REEVALUATE THIS LATER TODAY. WE ALSO EXTENDED THE ADVISORY FOR OUR
CENTRAL AND SOUTHERN OCEAN ZONES UNTIL 05Z TONIGHT AFTER
COLLABORATING WITH WFO AKQ. WE HELD OFF ON AN ADVISORY FOR DELAWARE
BAY AS THE GREATER FLOW LOOKS TO BE ACROSS THE OCEAN. SEAS WILL BE
NEAR 5 FEET THROUGH TONIGHT GIVEN THE FLOW INCREASING SOME AND
TURNING MORE NORTHEAST AND EAST.
OUTLOOK...
MONDAY...LINGERING SMALL CRAFT ISSUES POSSIBLE AS THE COASTAL WAVE
PULLS FURTHER NORTH WITH SEAS AND WINDS BEGINNING TO RELAX BY LATE
IN THE DAY.
TUESDAY AND WEDNESDAY...A FAIRLY TIGHT GRADIENT WILL EXIST FOR THE
TUESDAY THROUGH WEDNESDAY TIME FRAME WITH WINDS PICKING UP OUT OF
THE WEST OR NORTHWEST. WE COULD NEAR GALES ACROSS THE NORTH FOR A
BRIEF TIME PERIOD WEDNESDAY MORNING BUT CONFIDENCE IS RATHER LOW
RIGHT NOW. CONFIDENCE IS HIGH THAT A SMALL CRAFT WILL BE NEEDED FOR
THAT TIME FRAME.
THURSDAY...WINDS AND SEAS WILL SUBSIDE BELOW SMALL CRAFT ADVISORY
LEVELS AS HIGH PRESSURE BUILDS ACROSS THE REGION.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 5 AM EST MONDAY FOR PAZ060>062.
WINTER WEATHER ADVISORY UNTIL 3 AM EST MONDAY FOR PAZ101>106.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
MONDAY FOR PAZ054-055.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR PAZ070-
071.
NJ...WINTER WEATHER ADVISORY UNTIL 5 AM EST MONDAY FOR NJZ007-008.
WINTER WEATHER ADVISORY UNTIL 3 AM EST MONDAY FOR NJZ009.
WINTER WEATHER ADVISORY FROM 6 PM THIS EVENING TO 7 AM EST
MONDAY FOR NJZ001.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
NJZ016>019.
WINTER WEATHER ADVISORY UNTIL 1 AM EST MONDAY FOR NJZ010-012-
013-015.
DE...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR DEZ001.
MD...WINTER WEATHER ADVISORY UNTIL 7 PM EST THIS EVENING FOR MDZ008-
012-015-019-020.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ452>455.
SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 6 AM EST MONDAY
FOR ANZ450-451.
&&
$$
SYNOPSIS...HEAVENER/MEOLA
NEAR TERM...GORSE
SHORT TERM...NIERENBERG
LONG TERM...HEAVENER
AVIATION...GORSE/HEAVENER
MARINE...GORSE/HEAVENER/MEOLA
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1220 PM EST Sun Dec 8 2013
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1212 PM EST Sun Dec 8 2013
Wintry mix has turned to rain in the south and has dissipated to
just some patches of light freezing drizzle in the north/west, so
have canceled the advisory for the Bowling Green and Louisville
areas. Have replaced it with a Special Weather Statement for the
light patchy FZDZ.
Issued at 835 AM EST Sun Dec 8 2013
Ongoing winter weather event is panning out pretty much as expected
thus far across the region. The latest reports that continue to
filter in show up to 0.2 tenths of an inch of ice on trees and
elevated surfaces, with perhaps up to 0.25 inch in isolated
locations. The highest threat for icing up to 1/4 inch will be on a
line from Logan/Butler counties northeast to Clark/Madison/Garrard
counties. Thus far, reports indicate that side roads are a bit
icy in these areas, but main roads seem to be doing okay. Given the
short duration of the event (latest HRRR shows precip exiting most
locations by 19Z) and locations receiving the icing now will likely
get above freezing in the next couple of hours, will hold off on any
ice storm warning product for now. Certainly a high-end advisory
event in some areas, but impacts thus far continue to warrant
leaving the advisory as is. Updates already out.
.SHORT TERM (Now through Monday)...
Issued at 300 AM EST Sun Dec 8 2013
...A light wintry mix possible this morning...tending to change over
to just light rain by afternoon across south central Kentucky...
Upper air pattern shows a broad positively tilted trough across the
Rockies, with southwesterly flow extending from Oklahoma through New
England. Lift, associated with the right entrance region of a
departing jet, coupled with moisture overrunning a nearly stationary
boundary over Tennessee, will bring light mixed wintry precipitation
this morning over central Kentucky.
Forecast soundings show a warm layer around 850mb nosing northwards
across southern Kentucky, and eventually into the Bluegrass.
However, northeasterly winds will keep surface temperatures near
freezing along the Tennessee border, and in the mid to upper 20s
across central Kentucky.
Light mixed sleet and freezing rain will overspread southern
Kentucky during the predawn hours, and slowly move northeast towards
the Bluegrass and along the Ohio River around dawn or shortly after.
Towards Interstate 64, and across the Bluegrass, mixed precip may be
preceded by a period of light snow, with minor accumulations. By
noon, temperatures across our southern counties will slowly rise
above freezing. Any mixed precip should change over to rain or just
drizzle across the Bluegrass by mid to late afternoon. Along the
Ohio River, where snowcover remains, temperatures will struggle to
exceed freezing even by late afternoon.
Will continue with a winter weather advisory for light sleet and
icing across the central Commonwealth, and will likely allow it to
expire by early afternoon across our southern counties. We should
note that any icing or glaze will be light, as precipitation amounts
will likely stay under 2 tenths of an inch near the Ohio River,
ranging to maybe one half inch near the Lake Cumberland Region,
where temperatures will first rise above freezing. Despite light
precip amounts, any light glaze will adversely affect travel due to
antecedent cold pavement and ground.
Light precip will likely change over to just drizzle by
mid-afternoon as moisture become more shallow by evening. Continued
light rain may continue near Lake Cumberland, where a continued
fetch of moisture from the southwest may allow steadier
precipitation. Highs late this afternoon will range from the lower
40s near Lake Cumberland to the lower 30s across southern Indiana.
As this first wave passes, moisture will become more shallow, but
will continue saturated at low levels. So...expect cloudy skies this
evening and overnight, with maybe even some light fog and drizzle.
Temperatures won`t fall to much tonight, with lows not too far from
freezing south and east of the Ohio River.
Some partial clearing may arrive Monday afternoon, especially across
southern Indiana, with highs remaining in the 30s.
.LONG TERM (Monday Night through Saturday)...
Issued at 255 AM EST Sun Dec 8 2013
This period will begin with surface high pressure ridging across or
just north of the Ohio River. Aloft we will have a southwesterly
flow with an elongated vortmax stretching from southeast Ontario to
Oklahoma. Similar to yesterday`s 00Z model runs, today`s GFS/GEM/NAM
all have precip across our southeast early Tuesday as well as a
separate band of precip over southern Indiana, within the right
entrance region of a 180kt upper jet centered over Lake Erie. This
band, of what likely would be snow, is a little farther north than
what was forecast yesterday. The repetition in features, as well as
adding the new ECMWF into the mix, gives me enough of a signal to at
least put in a slight chance of snow across my north early Tuesday
and into the day. As for precip type across our southeast, that
mostly looks like snow from a quick look at soundings. We may warm
enough at the surface for a rain/snow mix. A quick look at forecast
totals for now indicates a sub-advisory event.
Another impulse moves through here Wednesday night, with a few of
the models hinting at low QPF just to our north. May get some
flurries out of this system across the north, but will leave
forecast dry for now.
High pressure on the back side of that system will shift east of our
area Friday, allowing for some southerly winds to try and start a
warmup for the weekend, at least closer to normal. With that warmup
will come another surge in moisture, bringing precip chances back
into the picture. Temperatures are at a range close enough to put in
a rain/snow mix Friday night through Saturday.
&&
.AVIATION (18Z TAF Update)...
Updated at 1218 PM EST Sun Dec 8 2013
The wintry mix has become very light across the region this
afternoon, but a prolonged period of IFR cigs or even LIFR cigs
appears increasingly likely tonight. These LIFR ceilings have already
moved into KBWG, and will likely affect KLEX as well. As another
disturbance pushes in from the southwest overnight, additional
low-level moisture will work into the region. This will cause
ceilings to remain IFR or LIFR through the overnight period, with
even a few light showers possible around KLEX or KBWG. KSDF will
be further removed from the deeper moisture overnight, so just
expect IFR cigs and perhaps some isolated drizzle. Winds will be
shifting from easterly to southerly to westerly by Monday morning.
Wind speeds will be generally light, around 7 knots or less.
Ceilings should slowly improve throughout the day on Monday,
lifting to MVFR thresholds by the mid to late morning hours.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...WINTER WEATHER ADVISORY until 6 PM EST this evening FOR
KYZ035>037-039>043-046>049-054>057.
WINTER WEATHER ADVISORY until 3 PM EST this afternoon FOR KYZ067.
IN...NONE.
&&
$$
Update.........KJD/13
Short Term.....JSD
Long Term......RJS
Aviation.......KJD
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1213 PM EST Sun Dec 8 2013
...Forecast Update...
Issued at 1212 PM EST Sun Dec 8 2013
Wintry mix has turned to rain in the south and has dissipated to
just some patches of light freezing drizzle in the north/west, so
have canceled the advisory for the Bowling Green and Louisville
areas. Have replaced it with a Special Weather Statement for the
light patchy FZDZ.
Issued at 835 AM EST Sun Dec 8 2013
Ongoing winter weather event is panning out pretty much as expected
thus far across the region. The latest reports that continue to
filter in show up to 0.2 tenths of an inch of ice on trees and
elevated surfaces, with perhaps up to 0.25 inch in isolated
locations. The highest threat for icing up to 1/4 inch will be on a
line from Logan/Butler counties northeast to Clark/Madison/Garrard
counties. Thus far, reports indicate that side roads are a bit
icy in these areas, but main roads seem to be doing okay. Given the
short duration of the event (latest HRRR shows precip exiting most
locations by 19Z) and locations receiving the icing now will likely
get above freezing in the next couple of hours, will hold off on any
ice storm warning product for now. Certainly a high-end advisory
event in some areas, but impacts thus far continue to warrant
leaving the advisory as is. Updates already out.
.SHORT TERM (Now through Monday)...
Issued at 300 AM EST Sun Dec 8 2013
...A light wintry mix possible this morning...tending to change over
to just light rain by afternoon across south central Kentucky...
Upper air pattern shows a broad positively tilted trough across the
Rockies, with southwesterly flow extending from Oklahoma through New
England. Lift, associated with the right entrance region of a
departing jet, coupled with moisture overrunning a nearly stationary
boundary over Tennessee, will bring light mixed wintry precipitation
this morning over central Kentucky.
Forecast soundings show a warm layer around 850mb nosing northwards
across southern Kentucky, and eventually into the Bluegrass.
However, northeasterly winds will keep surface temperatures near
freezing along the Tennessee border, and in the mid to upper 20s
across central Kentucky.
Light mixed sleet and freezing rain will overspread southern
Kentucky during the predawn hours, and slowly move northeast towards
the Bluegrass and along the Ohio River around dawn or shortly after.
Towards Interstate 64, and across the Bluegrass, mixed precip may be
preceded by a period of light snow, with minor accumulations. By
noon, temperatures across our southern counties will slowly rise
above freezing. Any mixed precip should change over to rain or just
drizzle across the Bluegrass by mid to late afternoon. Along the
Ohio River, where snowcover remains, temperatures will struggle to
exceed freezing even by late afternoon.
Will continue with a winter weather advisory for light sleet and
icing across the central Commonwealth, and will likely allow it to
expire by early afternoon across our southern counties. We should
note that any icing or glaze will be light, as precipitation amounts
will likely stay under 2 tenths of an inch near the Ohio River,
ranging to maybe one half inch near the Lake Cumberland Region,
where temperatures will first rise above freezing. Despite light
precip amounts, any light glaze will adversely affect travel due to
antecedent cold pavement and ground.
Light precip will likely change over to just drizzle by
mid-afternoon as moisture become more shallow by evening. Continued
light rain may continue near Lake Cumberland, where a continued
fetch of moisture from the southwest may allow steadier
precipitation. Highs late this afternoon will range from the lower
40s near Lake Cumberland to the lower 30s across southern Indiana.
As this first wave passes, moisture will become more shallow, but
will continue saturated at low levels. So...expect cloudy skies this
evening and overnight, with maybe even some light fog and drizzle.
Temperatures won`t fall to much tonight, with lows not too far from
freezing south and east of the Ohio River.
Some partial clearing may arrive Monday afternoon, especially across
southern Indiana, with highs remaining in the 30s.
.LONG TERM (Monday Night through Saturday)...
Issued at 255 AM EST Sun Dec 8 2013
This period will begin with surface high pressure ridging across or
just north of the Ohio River. Aloft we will have a southwesterly
flow with an elongated vortmax stretching from southeast Ontario to
Oklahoma. Similar to yesterday`s 00Z model runs, today`s GFS/GEM/NAM
all have precip across our southeast early Tuesday as well as a
separate band of precip over southern Indiana, within the right
entrance region of a 180kt upper jet centered over Lake Erie. This
band, of what likely would be snow, is a little farther north than
what was forecast yesterday. The repetition in features, as well as
adding the new ECMWF into the mix, gives me enough of a signal to at
least put in a slight chance of snow across my north early Tuesday
and into the day. As for precip type across our southeast, that
mostly looks like snow from a quick look at soundings. We may warm
enough at the surface for a rain/snow mix. A quick look at forecast
totals for now indicates a sub-advisory event.
Another impulse moves through here Wednesday night, with a few of
the models hinting at low QPF just to our north. May get some
flurries out of this system across the north, but will leave
forecast dry for now.
High pressure on the back side of that system will shift east of our
area Friday, allowing for some southerly winds to try and start a
warmup for the weekend, at least closer to normal. With that warmup
will come another surge in moisture, bringing precip chances back
into the picture. Temperatures are at a range close enough to put in
a rain/snow mix Friday night through Saturday.
&&
.AVIATION (12Z TAF Update)...
Updated at 607 AM EST Sun Dec 8 2013
Light mixed wintry precipitation will continue through the morning
hours at SDF and LEX. For BWG, light freezing rain will switch to
just light rain around 17z. Ceilings will lower to low end MVFR or
to IFR within this precipitation
For BWG,
Light sleet and freezing rain will continue with IFR ceilings
through the mid to late morning hours, after which, it will switch
over to just light rain and diminish. Precipitation rates will stay
light enough so that visibilities will stay in the upper MVFR range.
Light drizzle with continued IFR ceilings are likely this afternoon.
Cloudy skies and possibly light drizzle will continue overnight with
IFR ceilings.
For LEX,
Light sleet, possibly mixed at first with light snow will be ongoing
right around the TAF issuance time. Ceilings will lower to IFR by
14z and continue this way through much of the day. This will change
into light freezing rain which will continue through the morning
hours, eventually changing to light rain or drizzle by mid
afternoon. IFR ceilings are likely this evening and overnight.
For SDF,
Light sleet and snow will continue through the morning
hours...possibly changing to light freezing rain or freezing drizzle
by early afternoon. Precipitation rates will stay light, so that
ground-based visibilities will stay high in the MVFR or even VFR
range today. IFR ceilings are expected this afternoon and tonight.
Northeast winds of 5 to 10 mph tonight will veer to easterly by
morning. Winds will become southerly at around 5 mph this evening.
In general, for the overnight period and through early Monday, IFR
ceilings and possibly some MVFR visibilities will continue even with
a general lack of precipitation.
Ceilings will rise into the MVFR category for all TAF sites by
Monday afternoon as winds become westerly at 5 to 10mph after noon.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...WINTER WEATHER ADVISORY until 6 PM EST this evening FOR
KYZ035>037-039>043-046>049-054>057.
WINTER WEATHER ADVISORY until 3 PM EST this afternoon FOR KYZ067.
IN...NONE.
&&
$$
Update.........13/KJD
Short Term.....JSD
Long Term......RJS
Aviation.......JSD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
600 PM EST SUN DEC 8 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 400 PM EST SUN DEC 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS MOVING THROUGH
SE CO. AT THE SFC...LIGHT WINDS PREVAILED ACROSS UPPER MICHIGAN AS
ARCTIC HIGH PRES EXTENDED FROM NEW ENGLAND INTO THE NRN GREAT LAKES.
A LOW PRES TROUGH STRETCHED FROM SW KS THROUGH THE OH VALLEY. A
BROAD AREA OF LIGHT SNOW SUPPORTED BY WAA/280K-290K ISENTROPIC
LIFT...HAD SPREAD FROM MN/IA/WI INTO UPPER MI. HOWEVER...SNOW HAS
BEEN VERY LIGHT WITH VSBY TO 2-4SM FROM MNM-ESC AND ABOVE 5SM FROM
IMT-IWD.
LATE THIS AFTERNOON AND TONIGHT...AS THE SHORTWAVE CONTINUES TO LIFT
TOWARD THE GREAT LAKES EXPECT THE SNOW INTENSITY TO SLOWLY INCREASE.
HOWEVER...WITH THE STRONGER 700-300 MB QVECTOR CONV REMAINING SOUTH
OF THE AREA AND ONLY 1-2 G/KG AVAILABLE...GOING QPF VALUES IN THE
0.08-0.20 RANGE REMAIN ON TRACK. EXPECT SLR VALUES FROM NEAR 20/1
SOUTH TO 15/1 NORTH AS THE DGZ IS DEEPER AND EXTENDS MORE FAVORABLY
INTO THE LAYER OF GREATER UPWARD MOTION OVER THE SOUTH COMPARED TO
THE SHALLOW DGZ FARTHER NORTH IN THE COLDER AIR.
SO...FCST SNOWFALL AMOUNTS OF AROUND AN INCH NORTH TO 1 TO 3 INCHES
SOUTH ARE INCLUDED. THE HIGHER RES MODELS SUGGEST THAT AN AREA OF
LOW LEVEL CONV OVER NRN LAKE MI AHEAD OF THE AREA OF STRONGER SE
WINDS MAY PUSH A BAND OF LAKE ENHANCED SNOW INTO LOCATIONS BORDER
THE BAY OF GREEN BAY AND LAKE MICHIGAN LATE THIS EVENING. SINCE THE
BAND IS EXPECTED TO BE TRANSIENT...ADDITIONAL SNOW AMOUNTS OF ONLY
AN INCH OR TWO ARE EXPECTED WITH THIS FEATURE. A PERIOD OF SRLY
WINDS INTO SCHOOLCRAFT COUNTY COULD ALSO BRING A PERIOD OF MODERATE
SNOW LATE TONIGHT.
MONDAY...THE FIRST OF SEVERAL EMBEDDED SHORTWAVE TROUGHS WITHIN THE
DEEP EASTERN CANADIAN TROUGH WILL BE PUSHING THROUGH THE AREA MONDAY
MORNING. THE NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE
WESTERN CWA BEHIND A COLD FRONT AT THE START OF THE PERIOD. 850 MB
TEMPS FALLING TO -21 TO -23C BY THE AFTERNOON COMBINED WITH
INVERSION HEIGHTS RISING TO 8K-10K FT AND UNIDIRECTIONAL WESTERLY
WINDS SHOULD RESULT IN FAVORABLE LOW LEVEL CONV AND POTENTIAL FOR A
DOMINANT LES BAND INTO THE NRN KEWEENAW PENINSULA. WITH THE PASSAGE
OF THE SHRTWV...EXPECT THAT THE WINDS WOULD EVENTUALLY
VEER...PUSHING THE BAND SLOWLY TO THE SOUTH FROM NEAR EAGLE RIVER TO
CALUMET/MOHAWK AND TO HOUGHTON IN THE AFTERNOON. SNOWFALL
ACCUMULATIONS WILL GREATLY DEPEND ON HOW THE HEAVIER BAND LINGERS IN
ANY ONE LOCATION...BUT 12 HOUR ACCUMULATIONS OF AT LEAST 8 INCHES
REMAIN POSSIBLE. IN ADDITION...BLUSTERY WEST WINDS OF 20-30MPH WITH
GUSTS OVER 35 MPH WILL PRODUCE CONSIDERABLE BLOWING AND DRIFTING
SNOW AND VERY LOW VSBY. HOWEVER...SINCE THE HIGHER RES MODELS STILL
SHOW DIFFERENCES IN HANDLING WHERE THE BAND WILL DEVELOP AND HOW
LONG IT WILL LINGER...THE WATCH WAS NOT UPGRADED AT THIS TIME.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 PM EST SUN DEC 8 2013
ELOGATED AREA OF UPPER LEVEL TROUGHING STRETCHES FROM SKANDINAVIA
AND FAR NORTHWEST RUSSIA ACROSS THE NORTH POLE AND ACROSS MUCH OF
EASTERN CANADA AND AS FAR SOUTH AS THE WESTERN PORTIONS OF THE
CONUS. CORE OF COLDEST AIR RESIDES FROM NORTHERN GREENLAND ACROSS
CNTRL CANADA AND INTO THE NORTHERN PLAINS. H85 TEMP THIS MORNING
AT KINL WAS -25C WHILE IT WAS -17C AT KGRB. DECENT AGREEMENT THAT
UPCOMING WEEK WILL REMAIN CHILLY AS UPPER TROUGH BECOMES MORE
CENTERED OVER HUDSON BAY ALLOWING MULTIPLE PUSHES OF ARCTIC AIR TO
SWEEP ACROSS NORTHERN PLAINS AND GREAT LAKES IN NW FLOW ALOFT.
STILL INDICATIONS THAT COLD STARTS TO RELAX NEXT WEEKEND AS
TROUGHING REORIENTS FROM NORTH POLE TO DAVIS STRAIT AND GREENLAND
WHICH ALLOWS FOR MORE OF A ZONAL WEST-NORTHWEST FLOW ALOFT ACROSS
THE CONUS BY MIDDLE OF THE MONTH.
FIRST CONCERNING THE LK EFFECT ON MONDAY NIGHT. INITIAL SHORTWAVE IN
NW FLOW CURRENTLY OVER NORTHERN SASKATCHEWAN AND MANITOBA SWEEPS
ACROSS LK SUPERIOR REGION MONDAY AFTN. EXPECT MINIMAL SYNOPTIC
SUPPORT FOR ANY SNOW AS PVA/Q-VECTOR CONVERGENCE AT H7-H5/H85-H7
STAYS OVER LK SUPERIOR AND MAINLY NORTH. SFC LOW MOVING THROUGH ON
MONDAY DEEPENS NORTH OF LK SUPERIOR TOWARD JAMES BAY BY MONDAY
EVENING AS RESULT OF PVA/COLD AIR ADVECTION. RESULT IS INCREASING
UNSTABLE WESTERLY LOW- LEVEL FLOW ACROSS LK SUPERIOR. NAM SOUNDINGS
INDICATE VERY UNSTABLE CONDITIONS AS SHORTWAVE HELPS RAISE INVERSIONS
TO OVER 7KFT WITH LAKE EQL/S OVER 13KFT AT CMX AND P59 AND STDM4.
SFC-925MB STEERING WINDS VARY ENOUGH DURING PERIOD OF MOST FAVORABLE
INSTABILITY/MOSITURE/CONVERGENCE TO PEG WHERE HEAVIEST SNOW WILL
OCCUR. HIGH RES MODELS DO DIFFER HERE SOMEWHAT...WITH THE 12Z
REGIONAL GEM KEEPING THE STRONGEST CONVERGENCE MAINLY ALONG THE
NORTHWEST SHORE OF THE KEWEENAW THROUGH LATE AFTN...WHILE LOCAL WRF
IS MORE ON THE SOUTHERN EDGE...SETTING UP DOMINANT BAND MAINLY TO
SOUTH OF HOUGHTON AND HANCOCK. NAM AND NCEP WRF-ARW/NMM NESTS KIND OF
IN BTWN THOSE IDEAS. GIVEN THE DEGREE OF OVERWATER INSTABILITY...
POTENTIAL CERTAINTY THERE FOR TOTAL SNOW MONDAY AFTN THROUGH MONDAY
EVENING TO EXCEED A FOOT...IF THE BAND CAN PERSIST IN ONE LOCATION
FOR A WHILE. AT THE LEAST...MOST AREAS WILL SEE BURSTS OF HEAVIER
SNOW ALONG WITH STRONG/GUSTY WEST WINDS TO 40 MPH AND A LOT OF
BLOWING SNOW AND POOR VSBY. IN THE HEAVIER SNOW BAND...WHITEOUTS MAY
OCCUR MONDAY AFTN INTO MONDAY EVENING.
COORD WITH SHORT TERM FORECASTER AND DECIDED TO LEAVE GOING LK
EFFECT SNOW WATCH. NOT REALLY A QUESTION IF HEAVY LES/BLSN WILL
OCCUR...BUT MORE ONE OF WHERE THAT STRONG CONVERGENCE BAND WILL
DEVELOP. WILL LET MID SHIFT TAKE ANOTHER CRACK AT PINNING DOWN
LOCATION OF THE HEAVIER SNOW BAND.
ATTN LATER MONDAY NIGHT WILL BE ON SHORTWAVE PUSHING IN ACROSS
NORTHERN PLAINS AND ASSOCIATED SFC TROUGH. FIRST IMPACT FM THIS
WAVE WILL BE TO BACK WINDS SW...ALLOWING MOST OF HEAVIER LK EFFECT
SNOW TO PUSH OUT OVER LK SUPERIOR OFF THE KEWEENAW PENINSULA...THUS
THE ENDING TIME OF LATE MONDAY EVENING FOR LAKE EFFECT SNOW WATCH.
RIGHT AS THE LK EFFECT DIMINISHES FOR A WHILE...STILL APPEARS THAT
LGT SYNOPTIC SNOW WILL IMPACT MUCH OF CWA MAINLY IN THE MORNING.
BRIEF NOTE ABOUT WIND CHILLS FOR MONDAY NIGHT...INCREASING CLOUDS
AHEAD OF THE SYSTEM LATER MONDAY NIGHT SHOULD ALLOW TEMPS TO BEGIN TO
RISE. HAVE MINS WELL BLO ZERO...EVEN LESS THAN 10 BLO THROUGH EARLY
MORNING...THEN WITH THE ARRIVAL OF CLOUDS AND MORE WIND...EXPECT
TEMPS TO RISE TOWARD ZERO BY DAYBREAK ON TUESDAY. WILL BE CLOSE CALL
ON WIND CHILL READINGS NEAR CRITERIA BUT TEMPS MAY WARM JUST ENOUGH
TO KEEP WIND CHILLS GREATER THAN 25 BLO. AT THE LEAST...WIND CHILLS
WILL STILL BE A RATHER CHILLY 10 TO 20 BLO FOR MAJORITY OF WEST HALF
OF UPR MICHIGAN.
AS SFC LOW STRENGTHENS...MOISTURE/TEMPERATURE ADVECTION AHEAD OF
WAVE MIGHT RESULT IN MORE WIDESPREAD SNOW OVER EASTERN CWA LATE
MORNING INTO EARLY AFTN...WHERE A FEW INCHES OF SNOW COULD OCCUR.
OTHERWISE...EXPECT LESS THAN 1 INCH FOR THE CWA FROM THE SYSTEM.
ONCE THE SHORTWAVE AND SFC LOW CROSS THE AREA...SFC TROUGH ELONGATES
ACROSS SOUTHERN HALF OF LK SUPERIOR AND EVENTUALLY INTO NORTHERN
TIER OF UPR MICHIGAN. RESULT WILL BE LK EFFECT...MOSTLY OF MODERATE
INTENSITY...FOR THE WNW-NW FLOW AREAS. MOST CONCENTRATED/HEAVIER
SNOW SHOWERS LIKELY FOR THE SNOWBELTS OF ONTONAGON COUNTY FROM WHITE
PINE TO ROCKLAND AND ALSO TO THE EAST OF MUNISING AND TO THE NORTH
OF NEWBERRY...INCLUDING GRAND MARAIS. PERSISTENT LK EFFECT SETUP
CONTINUES THROUGH MUCH OF WEDNESDAY WITH INVERSIONS 5-8KFT AND
MORE THAN SUFFICIENT OVER-WATER INSTABILITY AS H85 TEMPS ARE NEAR
-25C. GIVEN SUCH COLD TEMPS THOUGH...SNOW WILL BE VERY FINE AND
MAIN ISSUE IN THE LK EFFECT AREAS WILL BE POWDERY SNOW BEING BLOWN
AROUND BY GUSTY WINDS RESULTING IN BLSN/POOR VSBY. AWAY FM THE LK
EFFECT COLD AIRMASS FIRMLY ENTRENCHED. SOME AREAS OF WESTERN CWA MAY
NOT REACH ZERO ON WEDNESDAY AFTN.
ANOTHER SYSTEM APPROACHING IN THE ACTIVE NW FLOW ALOFT COMES IN BY
THURSDAY MORNING. WINDS SHOULD BACK ENOUGH SW TO PUSH MOST OF THE LK
EFFECT OFFSHORE EXCEPT OVER THE KEWEENAW. HIGH PRESSURE RIDGE IN
VCNTY FIRST PART OF WED NIGHT WITH SUCH COLD AIRMASS SUGGESTS THAT
MINS COULD BE VERY LOW. LOWERED TEMPS TOWARD COLDER MOS NUMBERS...AND
FURTHER TWEAKED COLD SPOTS IN THE INTERIOR TOWARD 20 BLO ZERO. MAY BE
SIMILAR SETUP TO MONDAY NIGHT/TUESDAY NIGHT WHERE TEMPS RISE LATE.
MAIN CHANGE BESIDES LOWERING TEMPS WAS TO LOWER WIND SPEEDS TOO AS
WINDS MAY TRY TO GO CALM WITH THE RIDGE AROUND TO START THE NIGHT.
THUS...MAY NOT SEE WIND CHILL ISSUES UNLESS THAT INCOMING SYSTEM
TRENDS STRONGER.
IN WAKE OF THAT SYSTEM...SFC TROUGH SINKS ACROSS LK SUPERIOR AND UPR
MICHIGAN WHICH TURNS WINDS MORE NNW/N LATER THURSDAY AND FRIDAY.
KEPT IDEA OF INCREASING POPS FOR LK EFFECT ALONG MUCH OF LK SUPERIOR
COMPARED TO CONSENSUS POPS. MODELS HINT THAT WARMER AIR COULD TRY TO
WORK IN BY NEXT WEEKEND...AT LEAST RELATIVELY WARMER...AS FLOW SHOWS
SIGNS OF TRYING TO BECOME MORE ZONAL. MORE WIDESPREAD AREA OF WARM
AIR ADVECTION SNOW MAY TRY TO DEVELOP CLOSE TO THE REGION ALONG
RETREATING ARCTIC AIRMASS. THOSE TYPE OF DETAILS WILL BE HANDLED BY
LOW CHANCE POPS FOR THE TIME BEING. TEMPS THOUGH WARMER WILL STILL
BE RUNNING BLO NORMAL THROUGH THE END OF THE EXTENDED.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 600 PM EST SUN DEC 8 2013
WIDESPREAD LIGHT SNOW WILL CONTINUE TONIGHT WITH MVFR/IFR CONDITIONS
CONTINUING. IFR CONDITIONS ARE MOST LIKELY TO DEVELOP AT SAW.
CONDITIONS SHOULD IMPROVE TO MVFR BY LATE TONIGHT OR MON MORNING AT
IWD AND SAW. LAKE EFFECT SNOW WITH VLIFR VSBY IS EXPECTED AT CMX BY
MID MORNING AS WINDS VEER TO THE WEST AND BECOME GUSTY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES OF GALES. THE FIRST WILL PASS
SOUTHEAST OF UPPER MI MONDAY MORNING. BEHIND THIS TROUGH...WINDS
WILL VEER TO THE WEST AND INCREASE TO GALES TO 35 TO 40 KNOTS ACROSS
LAKE SUPERIOR MONDAY AFTERNOON AND EVENING. AFTER A DECREASE TO 20
TO 30 KNOT SOUTHWEST WINDS TUESDAY MORNING...LOW PRESSURE WILL TRACK
EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND PRODUCE ANOTHER ROUND
OF GALES TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON AND EVENING. THE
WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30 KNOTS FROM LATE
TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE EXTENDING FROM HIGH
PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS INTO THE AREA.
CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE POSSIBLE
THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR ACROSS THE
LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE SOUTHEASTWARD
ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WINDS SHOULD
REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 9 AM EST MONDAY FOR MIZ007-014-085.
LAKE EFFECT SNOW WATCH FROM MONDAY MORNING THROUGH MONDAY
EVENING FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 7 AM EST /6 AM CST/ MONDAY FOR
MIZ012-013.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM MONDAY TO 7 AM EST
TUESDAY FOR LSZ245-248>251-265>267.
GALE WARNING FROM 1 PM MONDAY TO 5 AM EST TUESDAY FOR LSZ244-245-
265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM EST /NOON CST/ MONDAY TO
7 AM EST /6 AM CST/ TUESDAY FOR LSZ162-240>244-263-264.
GALE WARNING FROM 4 PM MONDAY TO 5 AM EST TUESDAY FOR LSZ264.
GALE WARNING FROM 1 PM MONDAY TO MIDNIGHT EST MONDAY NIGHT FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
402 PM EST SUN DEC 8 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 400 PM EST SUN DEC 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS MOVING THROUGH
SE CO. AT THE SFC...LIGHT WINDS PREVAILED ACROSS UPPER MICHIGAN AS
ARCTIC HIGH PRES EXTENDED FROM NEW ENGLAND INTO THE NRN GREAT LAKES.
A LOW PRES TROUGH STRETCHED FROM SW KS THROUGH THE OH VALLEY. A
BROAD AREA OF LIGHT SNOW SUPPORTED BY WAA/280K-290K ISENTROPIC
LIFT...HAD SPREAD FROM MN/IA/WI INTO UPPER MI. HOWEVER...SNOW HAS
BEEN VERY LIGHT WITH VSBY TO 2-4SM FROM MNM-ESC AND ABOVE 5SM FROM
IMT-IWD.
LATE THIS AFTERNOON AND TONIGHT...AS THE SHORTWAVE CONTINUES TO LIFT
TOWARD THE GREAT LAKES EXPECT THE SNOW INTENSITY TO SLOWLY INCREASE.
HOWEVER...WITH THE STRONGER 700-300 MB QVECTOR CONV REMAINING SOUTH
OF THE AREA AND ONLY 1-2 G/KG AVAILABLE...GOING QPF VALUES IN THE
0.08-0.20 RANGE REMAIN ON TRACK. EXPECT SLR VALUES FROM NEAR 20/1
SOUTH TO 15/1 NORTH AS THE DGZ IS DEEPER AND EXTENDS MORE FAVORABLY
INTO THE LAYER OF GREATER UPWARD MOTION OVER THE SOUTH COMPARED TO
THE SHALLOW DGZ FARTHER NORTH IN THE COLDER AIR.
SO...FCST SNOWFALL AMOUNTS OF AROUND AN INCH NORTH TO 1 TO 3 INCHES
SOUTH ARE INCLUDED. THE HIGHER RES MODELS SUGGEST THAT AN AREA OF
LOW LEVEL CONV OVER NRN LAKE MI AHEAD OF THE AREA OF STRONGER SE
WINDS MAY PUSH A BAND OF LAKE ENHANCED SNOW INTO LOCATIONS BORDER
THE BAY OF GREEN BAY AND LAKE MICHIGAN LATE THIS EVENING. SINCE THE
BAND IS EXPECTED TO BE TRANSIENT...ADDITIONAL SNOW AMOUNTS OF ONLY
AN INCH OR TWO ARE EXPECTED WITH THIS FEATURE. A PERIOD OF SRLY
WINDS INTO SCHOOLCRAFT COUNTY COULD ALSO BRING A PERIOD OF MODERATE
SNOW LATE TONIGHT.
MONDAY...THE FIRST OF SEVERAL EMBEDDED SHORTWAVE TROUGHS WITHIN THE
DEEP EASTERN CANADIAN TROUGH WILL BE PUSHING THROUGH THE AREA MONDAY
MORNING. THE NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE
WESTERN CWA BEHIND A COLD FRONT AT THE START OF THE PERIOD. 850 MB
TEMPS FALLING TO -21 TO -23C BY THE AFTERNOON COMBINED WITH
INVERSION HEIGHTS RISING TO 8K-10K FT AND UNIDIRECTIONAL WESTERLY
WINDS SHOULD RESULT IN FAVORABLE LOW LEVEL CONV AND POTENTIAL FOR A
DOMINANT LES BAND INTO THE NRN KEWEENAW PENINSULA. WITH THE PASSAGE
OF THE SHRTWV...EXPECT THAT THE WINDS WOULD EVENTUALLY
VEER...PUSHING THE BAND SLOWLY TO THE SOUTH FROM NEAR EAGLE RIVER TO
CALUMET/MOHAWK AND TO HOUGHTON IN THE AFTERNOON. SNOWFALL
ACCUMULATIONS WILL GREATLY DEPEND ON HOW THE HEAVIER BAND LINGERS IN
ANY ONE LOCATION...BUT 12 HOUR ACCUMULATIONS OF AT LEAST 8 INCHES
REMAIN POSSIBLE. IN ADDITION...BLUSTERY WEST WINDS OF 20-30MPH WITH
GUSTS OVER 35 MPH WILL PRODUCE CONSIDERABLE BLOWING AND DRIFTING
SNOW AND VERY LOW VSBY. HOWEVER...SINCE THE HIGHER RES MODELS STILL
SHOW DIFFERENCES IN HANDLING WHERE THE BAND WILL DEVELOP AND HOW
LONG IT WILL LINGER...THE WATCH WAS NOT UPGRADED AT THIS TIME.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 PM EST SUN DEC 8 2013
ELOGATED AREA OF UPPER LEVEL TROUGHING STRETCHES FROM SKANDINAVIA
AND FAR NORTHWEST RUSSIA ACROSS THE NORTH POLE AND ACROSS MUCH OF
EASTERN CANADA AND AS FAR SOUTH AS THE WESTERN PORTIONS OF THE
CONUS. CORE OF COLDEST AIR RESIDES FROM NORTHERN GREENLAND ACROSS
CNTRL CANADA AND INTO THE NORTHERN PLAINS. H85 TEMP THIS MORNING
AT KINL WAS -25C WHILE IT WAS -17C AT KGRB. DECENT AGREEMENT THAT
UPCOMING WEEK WILL REMAIN CHILLY AS UPPER TROUGH BECOMES MORE
CENTERED OVER HUDSON BAY ALLOWING MULTIPLE PUSHES OF ARCTIC AIR TO
SWEEP ACROSS NORTHERN PLAINS AND GREAT LAKES IN NW FLOW ALOFT.
STILL INDICATIONS THAT COLD STARTS TO RELAX NEXT WEEKEND AS
TROUGHING REORIENTS FROM NORTH POLE TO DAVIS STRAIT AND GREENLAND
WHICH ALLOWS FOR MORE OF A ZONAL WEST-NORTHWEST FLOW ALOFT ACROSS
THE CONUS BY MIDDLE OF THE MONTH.
FIRST CONCERNING THE LK EFFECT ON MONDAY NIGHT. INITIAL SHORTWAVE IN
NW FLOW CURRENTLY OVER NORTHERN SASKATCHEWAN AND MANITOBA SWEEPS
ACROSS LK SUPERIOR REGION MONDAY AFTN. EXPECT MINIMAL SYNOPTIC
SUPPORT FOR ANY SNOW AS PVA/Q-VECTOR CONVERGENCE AT H7-H5/H85-H7
STAYS OVER LK SUPERIOR AND MAINLY NORTH. SFC LOW MOVING THROUGH ON
MONDAY DEEPENS NORTH OF LK SUPERIOR TOWARD JAMES BAY BY MONDAY
EVENING AS RESULT OF PVA/COLD AIR ADVECTION. RESULT IS INCREASING
UNSTABLE WESTERLY LOW- LEVEL FLOW ACROSS LK SUPERIOR. NAM SOUNDINGS
INDICATE VERY UNSTABLE CONDITIONS AS SHORTWAVE HELPS RAISE INVERSIONS
TO OVER 7KFT WITH LAKE EQL/S OVER 13KFT AT CMX AND P59 AND STDM4.
SFC-925MB STEERING WINDS VARY ENOUGH DURING PERIOD OF MOST FAVORABLE
INSTABILITY/MOSITURE/CONVERGENCE TO PEG WHERE HEAVIEST SNOW WILL
OCCUR. HIGH RES MODELS DO DIFFER HERE SOMEWHAT...WITH THE 12Z
REGIONAL GEM KEEPING THE STRONGEST CONVERGENCE MAINLY ALONG THE
NORTHWEST SHORE OF THE KEWEENAW THROUGH LATE AFTN...WHILE LOCAL WRF
IS MORE ON THE SOUTHERN EDGE...SETTING UP DOMINANT BAND MAINLY TO
SOUTH OF HOUGHTON AND HANCOCK. NAM AND NCEP WRF-ARW/NMM NESTS KIND OF
IN BTWN THOSE IDEAS. GIVEN THE DEGREE OF OVERWATER INSTABILITY...
POTENTIAL CERTAINTY THERE FOR TOTAL SNOW MONDAY AFTN THROUGH MONDAY
EVENING TO EXCEED A FOOT...IF THE BAND CAN PERSIST IN ONE LOCATION
FOR A WHILE. AT THE LEAST...MOST AREAS WILL SEE BURSTS OF HEAVIER
SNOW ALONG WITH STRONG/GUSTY WEST WINDS TO 40 MPH AND A LOT OF
BLOWING SNOW AND POOR VSBY. IN THE HEAVIER SNOW BAND...WHITEOUTS MAY
OCCUR MONDAY AFTN INTO MONDAY EVENING.
COORD WITH SHORT TERM FORECASTER AND DECIDED TO LEAVE GOING LK
EFFECT SNOW WATCH. NOT REALLY A QUESTION IF HEAVY LES/BLSN WILL
OCCUR...BUT MORE ONE OF WHERE THAT STRONG CONVERGENCE BAND WILL
DEVELOP. WILL LET MID SHIFT TAKE ANOTHER CRACK AT PINNING DOWN
LOCATION OF THE HEAVIER SNOW BAND.
ATTN LATER MONDAY NIGHT WILL BE ON SHORTWAVE PUSHING IN ACROSS
NORTHERN PLAINS AND ASSOCIATED SFC TROUGH. FIRST IMPACT FM THIS
WAVE WILL BE TO BACK WINDS SW...ALLOWING MOST OF HEAVIER LK EFFECT
SNOW TO PUSH OUT OVER LK SUPERIOR OFF THE KEWEENAW PENINSULA...THUS
THE ENDING TIME OF LATE MONDAY EVENING FOR LAKE EFFECT SNOW WATCH.
RIGHT AS THE LK EFFECT DIMINISHES FOR A WHILE...STILL APPEARS THAT
LGT SYNOPTIC SNOW WILL IMPACT MUCH OF CWA MAINLY IN THE MORNING.
BRIEF NOTE ABOUT WIND CHILLS FOR MONDAY NIGHT...INCREASING CLOUDS
AHEAD OF THE SYSTEM LATER MONDAY NIGHT SHOULD ALLOW TEMPS TO BEGIN TO
RISE. HAVE MINS WELL BLO ZERO...EVEN LESS THAN 10 BLO THROUGH EARLY
MORNING...THEN WITH THE ARRIVAL OF CLOUDS AND MORE WIND...EXPECT
TEMPS TO RISE TOWARD ZERO BY DAYBREAK ON TUESDAY. WILL BE CLOSE CALL
ON WIND CHILL READINGS NEAR CRITERIA BUT TEMPS MAY WARM JUST ENOUGH
TO KEEP WIND CHILLS GREATER THAN 25 BLO. AT THE LEAST...WIND CHILLS
WILL STILL BE A RATHER CHILLY 10 TO 20 BLO FOR MAJORITY OF WEST HALF
OF UPR MICHIGAN.
AS SFC LOW STRENGTHENS...MOISTURE/TEMPERATURE ADVECTION AHEAD OF
WAVE MIGHT RESULT IN MORE WIDESPREAD SNOW OVER EASTERN CWA LATE
MORNING INTO EARLY AFTN...WHERE A FEW INCHES OF SNOW COULD OCCUR.
OTHERWISE...EXPECT LESS THAN 1 INCH FOR THE CWA FROM THE SYSTEM.
ONCE THE SHORTWAVE AND SFC LOW CROSS THE AREA...SFC TROUGH ELONGATES
ACROSS SOUTHERN HALF OF LK SUPERIOR AND EVENTUALLY INTO NORTHERN
TIER OF UPR MICHIGAN. RESULT WILL BE LK EFFECT...MOSTLY OF MODERATE
INTENSITY...FOR THE WNW-NW FLOW AREAS. MOST CONCENTRATED/HEAVIER
SNOW SHOWERS LIKELY FOR THE SNOWBELTS OF ONTONAGON COUNTY FROM WHITE
PINE TO ROCKLAND AND ALSO TO THE EAST OF MUNISING AND TO THE NORTH
OF NEWBERRY...INCLUDING GRAND MARAIS. PERSISTENT LK EFFECT SETUP
CONTINUES THROUGH MUCH OF WEDNESDAY WITH INVERSIONS 5-8KFT AND
MORE THAN SUFFICIENT OVER-WATER INSTABILITY AS H85 TEMPS ARE NEAR
-25C. GIVEN SUCH COLD TEMPS THOUGH...SNOW WILL BE VERY FINE AND
MAIN ISSUE IN THE LK EFFECT AREAS WILL BE POWDERY SNOW BEING BLOWN
AROUND BY GUSTY WINDS RESULTING IN BLSN/POOR VSBY. AWAY FM THE LK
EFFECT COLD AIRMASS FIRMLY ENTRENCHED. SOME AREAS OF WESTERN CWA MAY
NOT REACH ZERO ON WEDNESDAY AFTN.
ANOTHER SYSTEM APPROACHING IN THE ACTIVE NW FLOW ALOFT COMES IN BY
THURSDAY MORNING. WINDS SHOULD BACK ENOUGH SW TO PUSH MOST OF THE LK
EFFECT OFFSHORE EXCEPT OVER THE KEWEENAW. HIGH PRESSURE RIDGE IN
VCNTY FIRST PART OF WED NIGHT WITH SUCH COLD AIRMASS SUGGESTS THAT
MINS COULD BE VERY LOW. LOWERED TEMPS TOWARD COLDER MOS NUMBERS...AND
FURTHER TWEAKED COLD SPOTS IN THE INTERIOR TOWARD 20 BLO ZERO. MAY BE
SIMILAR SETUP TO MONDAY NIGHT/TUESDAY NIGHT WHERE TEMPS RISE LATE.
MAIN CHANGE BESIDES LOWERING TEMPS WAS TO LOWER WIND SPEEDS TOO AS
WINDS MAY TRY TO GO CALM WITH THE RIDGE AROUND TO START THE NIGHT.
THUS...MAY NOT SEE WIND CHILL ISSUES UNLESS THAT INCOMING SYSTEM
TRENDS STRONGER.
IN WAKE OF THAT SYSTEM...SFC TROUGH SINKS ACROSS LK SUPERIOR AND UPR
MICHIGAN WHICH TURNS WINDS MORE NNW/N LATER THURSDAY AND FRIDAY.
KEPT IDEA OF INCREASING POPS FOR LK EFFECT ALONG MUCH OF LK SUPERIOR
COMPARED TO CONSENSUS POPS. MODELS HINT THAT WARMER AIR COULD TRY TO
WORK IN BY NEXT WEEKEND...AT LEAST RELATIVELY WARMER...AS FLOW SHOWS
SIGNS OF TRYING TO BECOME MORE ZONAL. MORE WIDESPREAD AREA OF WARM
AIR ADVECTION SNOW MAY TRY TO DEVELOP CLOSE TO THE REGION ALONG
RETREATING ARCTIC AIRMASS. THOSE TYPE OF DETAILS WILL BE HANDLED BY
LOW CHANCE POPS FOR THE TIME BEING. TEMPS THOUGH WARMER WILL STILL
BE RUNNING BLO NORMAL THROUGH THE END OF THE EXTENDED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1218 PM EST SUN DEC 8 2013
A DISTURBANCE AND WIDESPREAD AREA OF LIGHT SNOW WILL MOVE FROM WI
INTO UPPER MICHIGAN THIS AFTERNOON. EXPECT -SN/MVFR CONDITIONS TO
SPREAD NE TO ALL TERMINALS DURING THE AFTERNOON...BEGINNING FIRST AT
KIWD. WITH KSAW CLOSER TO THE TRACK OF THE DISTURBANCE...IFR
CONDITIONS ARE MORE LIKELY TO DEVELOP THERE IN THE EVENING.
CONDITIONS SHOULD IMPROVE TO MVFR BY LATE TONIGHT OR MON MORNING AT
IWD AND SAW. LAKE EFFECT SNOW WITH LIFR VSBY IS EXPECTED AT CMX BY
MID MORNING AS WINDS VEER TO THE WEST.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES OF GALES. THE FIRST WILL PASS
SOUTHEAST OF UPPER MI MONDAY MORNING. BEHIND THIS TROUGH...WINDS
WILL VEER TO THE WEST AND INCREASE TO GALES TO 35 TO 40 KNOTS ACROSS
LAKE SUPERIOR MONDAY AFTERNOON AND EVENING. AFTER A DECREASE TO 20
TO 30 KNOT SOUTHWEST WINDS TUESDAY MORNING...LOW PRESSURE WILL TRACK
EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND PRODUCE ANOTHER ROUND
OF GALES TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON AND EVENING. THE
WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30 KNOTS FROM LATE
TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE EXTENDING FROM HIGH
PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS INTO THE AREA.
CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE POSSIBLE
THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR ACROSS THE
LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE SOUTHEASTWARD
ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WINDS SHOULD
REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 AM EST
MONDAY FOR MIZ007-014-085.
LAKE EFFECT SNOW WATCH FROM MONDAY MORNING THROUGH MONDAY
EVENING FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 7 AM EST /6 AM CST/ MONDAY FOR
MIZ012-013.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM MONDAY TO 7 AM EST
TUESDAY FOR LSZ245-248>251-265>267.
GALE WARNING FROM 1 PM MONDAY TO 5 AM EST TUESDAY FOR LSZ244-245-
265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM EST /NOON CST/ MONDAY TO
7 AM EST /6 AM CST/ TUESDAY FOR LSZ162-240>244-263-264.
GALE WARNING FROM 4 PM MONDAY TO 5 AM EST TUESDAY FOR LSZ264.
GALE WARNING FROM 1 PM MONDAY TO MIDNIGHT EST MONDAY NIGHT FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1219 PM EST SUN DEC 8 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 601 AM EST SUN DEC 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS MOVING THROUGH
UTAH EARLY THIS MORNING AND THIS FEATURE WILL BRING A SHOT OF
WIDESPREAD SYSTEM SNOW TO MUCH OF THE AREA TONIGHT INTO EARLY
MONDAY. STRONG SFC HIGH PRESSURE CENTERED JUST SOUTH OF OUR AREA
INTO WISCONSIN HAS RESULTED IN VERY COLD TEMPS (5 TO 15 BELOW ZERO)
EARLY THIS MORNING...ESPECIALLY ACROSS THE WESTERN INTERIOR OF UPPER
MICHIGAN. NOT MUCH WIND ACCOMPANYING THESE COLD TEMPS SO WENT AHEAD
AND CANCELLED THE WIND CHILL ADVISORY FOR THE WESTERN INTERIOR CWA.
WIND PARALLEL LES BANDS STILL IMPACTING THE KEWEENAW PENINSULA AND
ERN SHORELINE AREAS EARLY THIS MORNING IN CONVERGENT LOW-LVL
WESTERLY FLOW. WOULD NOT BE SURPRISED IF THESE AREAS ESPECIALLY THE
KEWEENAW RECEIVED AN ADDITIONAL 3 TO 5 INCHES OF LES OVERNIGHT.
TODAY...ANY REMAINING LES IS EXPECTED TO LIFT NORTH OF THE KEWEENAW
AND THE SHORELINES OF THE ERN COUNTIES AS WINDS BEGIN TO BACK SW IN
THE DEVELOPING WAA PATTERN. A BROAD AREA OF 275K-285K ISENTROPIC
LIFT AHEAD OF SHORTWAVE LIFTING OUT OF THE WRN CONUS TROF WILL
SPREAD LIGHT SNOW FROM MN/WI INTO UPPER MI DURING THE AFTERNOON.
ALTHOUGH...THE VERY DRY LOW LEVELS IN THE ARCTIC AIRMASS MAY DELAY
THE ONSET OF THE PCPN...EXPECT AT LEAST SOME LIGHT SNOW OVER THE
SOUTH BY EARLY AFTERNOON THAT WILL SPREAD THROUGH THE REST OF THE
CWA BY MID TO LATE AFTERNOON. ACCUMULATIONS BY 00Z WILL BE
RELATIVELY LIGHT...GENERALLY A HALF INCH OR LESS MOST AREAS WITH
MAYBE UP TO AN INCH SOUTH CENTRAL ALONG LAKE MI CLOSER TO BEST
ISENTROPIC LIFT AND Q-VECT CONV.
TONIGHT...AS THE SHORTWAVE CONTINUES TO LIFT TOWARD THE GREAT LAKES
FORCING IN LEFT EXIT REGION OF UPPER JET AND ASSOC 700-600 MB FGEN
RESPONSE ALONG WITH NOTED MINIMAL SLANTWISE INSTABILITY/NEGATIVE EPV
OFF CROSS SECTIONS COULD RESULT IN HEAVIER BANDED SNOW OVER SE
COUNTIES. ENHANCEMENT TO SYSTEM SNOW IS ALSO POSSIBLE NEAR BAY OF
GREEN BAY AND LK MICHIGAN WITH ESE SHIFTING SOUTH THROUGH THE NIGHT
/E WINDS IN LOW-LEVELS WITH 8H TEMPS AROUND -12C AND LK MICHIGAN
WATER TEMPS AROUND +5C. BIGGEST LIMITING FACTOR FOR LAKE ENHANCED
SNOW WILL BE SHIFTING WIND DIRECTION. EXPECT GENERAL 1-3" OF
SYNOPTIC SNOW WITH MIXING RATIOS 1-2G/KG AND WITH 0.15-0.20 AVERAGED
MODEL QPF USING SLR/S AROUND 18:1. BASED ON SOUNDINGS...HIGHER SLR/S
SEEM UNLIKELY DUE TO BEST LIFT OCCURING ABV DGZ. COULD SEE ANOTHER
1-2 OF LAKE ENHANCEMENT ON TOP OF SYSTEM SNOW PUSHING TOTAL SNOW
AMOUNTS INTO LOW END ADVISORY CATEGORY WITH 4-5 INCHES. AS A
RESULT...WILL CONTINUE THE WINTER WX ADVISORY FOR SE AND ERN
COUNTIES TONIGHT INTO EARLY MONDAY. FARTHER WEST GENERALLY EXPECT NO
MORE THAN 1-2 INCHES OF TOTAL SNOWFALL.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 601 AM EST SUN DEC 8 2013
PERSISTENT DEEP TROUGHING OVER THE EASTERN HALF OF CANADA WILL BRING
REINFORCING SHOTS OF ARCTIC AIR THROUGH THE WEEK AHEAD. LAKE EFFECT
SNOW WILL ONCE AGAIN AFFECT LOCATIONS THAT SAW PLENTY THE LAST FEW
DAYS AS W TO WNW FLOW REMAINS FAIRLY CONTINUOUS. A WEAK CLIPPER
SYSTEM LOOKS TO BE THE ONLY REAL SHOT OF VERY LIGHT SYNOPTIC
SNOWFALL FOR THE ENTIRE CWA LATE MONDAY NIGHT INTO TUESDAY MORNING.
MONDAY...THE FIRST OF SEVERAL EMBEDDED SHORTWAVE TROUGHS WITHIN THE
DEEP EASTERN CANADIAN TROUGH WILL BE PUSHING THROUGH THE AREA MONDAY
MORNING. SEE THE SHORT TERM DISCUSSION FOR DETAILS REGARDING THE
MAIN PORTION OF THIS SYSTEM TONIGHT.
THE NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE WESTERN
CWA BEHIND A COLD FRONT AT THE START OF THE PERIOD. H8 TEMPS FALLING
TO -21 TO -23C BY THE AFTERNOON COMBINED WITH INVERSION HEIGHTS
RISING TO 7KFT AND UNIDIRECTIONAL WESTERLY WINDS SHOULD RESULT IN A
FAIRLY PERSISTENT DOMINATE LAKE EFFECT SNOW BAND AFFECTING NORTHERN
HOUGHTON AND SOUTHERN KEWEENAW COUNTIES. BLUSTERY WEST WINDS OF
20-30MPH WITH GUSTS OVER 35 MPH WILL MAKE CONDITIONS POOR...BUT IF
THE BAND REMAINS ANCHORED IN ONE AREA FOR AT LEAST SEVERAL
HOURS...WARNING CRITERIA SNOW WILL BE POSSIBLE. BECAUSE OF THIS
POTENTIAL ALONG WITH POSSIBLE NEAR BLIZZARD CONDITIONS AT
TIMES...HAVE ISSUED A LAKE EFFECT SNOW WATCH FOR NORTHERN HOUGHTON
AND KEWEENAW COUNTIES MONDAY MORNING INTO MONDAY EVENING. GUSTY
WINDS WILL LIKELY CONTINUE WELL INTO THE NIGHT...SO BLOWING SNOW
WILL REMAIN A PROBLEM. OVERALL...EXPECTATION IS THAT SOME LOCATIONS
COULD SEE IN EXCESS OF A FOOT OF SNOW MONDAY MORNING THROUGH
EVENING...WITH EVEN HIGHER AMOUNTS IF THE BAND REMAINS IN PLACE.
THROUGH...WITH A SLIGHT VEERING OF THE ABOVE-SFC WINDS AHEAD OF A
WEAK MID-LEVEL RIDGE LATE MONDAY AFTERNOON...THE BAND WILL LIKELY
WAVER SOMEWHAT.
MONDAY NIGHT AND TUESDAY...SUFFICIENT MODEL AGREEMENT AND
RUN-TO-RUN CONTINUITY THROUGH THIS PERIOD LEADS TO HIGHER
CONFIDENCE IN THE GOING FORECAST. DID NOT CHANGE MUCH FROM THE
PREVIOUS SHIFT OTHER THAN MAKE SOME MINOR ADJUSTMENTS TO POPS AND
QPF. THE SECOND OF MULTIPLE WAVES ON THE DEEP TROUGH IS PROGGED TO
CROSS UPPER MI LATE MONDAY NIGHT. LITTLE ADDITIONAL SYNOPTIC SUPPORT
WILL BE PRESENT WITH THIS TROUGH...SO ONLY A DUSTING OF SNOW IS
EXPECTED FOR MOST LOCATIONS IN THE CWA TUESDAY MORNING. THE APPROACH
OF THE TROUGH SHOULD BE ENOUGH TO LIMIT LES OFF ON THE KEWEENAW FOR
AT LEAST A SHORT TIME FRAME TUESDAY.
ALSO OF NOTE...LOW TEMPS MONDAY NIGHT HAVE A HIGH COMPONENT OF
VARIABILITY WITH THEM AS A WEAK SFC RIDGE CROSSES THE CWA WHILE HIGH
CLOUDS AHEAD OF TUESDAYS SYSTEM FILTER INTO THE AREA. WENT WITH
COLDEST TEMPS TO AROUND -10F INTERIOR CENTRAL AS THAT AREA LOOKS TO
HAVE THE LONGEST PERIOD OF UNINTERRUPTED COOLING.
TUESDAY NIGHT THROUGH THURSDAY...YET ANOTHER BLAST OF ARCTIC AIR
ARRIVES BEHIND TUESDAYS SYSTEM...THIS TIME WITH H8 TEMPS PUSHING
-25C BY WEDNESDAY AFTERNOON. COULD SEE SOME LOCATIONS WEST ALONG THE
WI BORDER FAIL TO GET ABOVE ZERO ON WEDNESDAY. VERY COLD TEMPS ARE
EXPECTED THROUGH THURSDAY...WITH WIND CHILL READINGS TO -30F
WEDNESDAY NIGHT INTERIOR WEST. WINDS MAY REMAIN LIGHT...SO WIND
CHILL HEADLINES MAY NOT BE NECESSARY.
LAKE EFFECT SNOW WILL ONCE AGAIN BE A CONCERN THROUGH THIS
STRETCH...ONLY THIS TIME WITH A LITTLE MORE OF A NORTHERLY COMPONENT
TO THE WIND. THIS WILL BRING THE POTENTIAL FOR HEAVY LES TUESDAY
NIGHT THROUGH THURSDAY NIGHT FOR THE KEWEENAW AND LOCATIONS EAST OF
MUNISING ALONG LAKE SUPERIOR. THE SETUP LOOKS FAIRLY SIMILAR TO THE
PAST SEVERAL DAYS...SO WOULD NOT BE SURPRISED TO SEE A DOMINATE BAND
AFFECTING BOTH OF THE AFOREMENTIONED LOCATIONS.
FRIDAY AND SATURDAY...MODEL GUIDANCE DIVERGES QUICKLY AT THIS
POINT...WITH THE ECMWF PULLING DOWN ONE MORE ARCTIC AIR MASS WHILE
THE GFS TRENDS TO A MORE ZONAL PATTERN. EITHER WAY...A BRIEF ROUND
OF LIGHT SYNOPTIC SNOW LOOKS POSSIBLE THURSDAY NIGHT INTO FRIDAY.
CONTINUED TO EMPLOY A CONSENSUS FORECAST AT THIS POINT. TEMPERATURES
WILL MODERATE SOMEWHAT BY NEXT WEEKEND...BUT STILL REMAIN 5 TO 10
DEGREES BELOW NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1218 PM EST SUN DEC 8 2013
A DISTURBANCE AND WIDESPREAD AREA OF LIGHT SNOW WILL MOVE FROM WI
INTO UPPER MICHIGAN THIS AFTERNOON. EXPECT -SN/MVFR CONDITIONS TO
SPREAD NE TO ALL TERMINALS DURING THE AFTERNOON...BEGINNING FIRST AT
KIWD. WITH KSAW CLOSER TO THE TRACK OF THE DISTURBANCE...IFR
CONDITIONS ARE MORE LIKELY TO DEVELOP THERE IN THE EVENING.
CONDITIONS SHOULD IMPROVE TO MVFR BY LATE TONIGHT OR MON MORNING AT
IWD AND SAW. LAKE EFFECT SNOW WITH LIFR VSBY IS EXPECTED AT CMX BY
MID MORNING AS WINDS VEER TO THE WEST.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 601 AM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES OF GALES. THE FIRST WILL PASS
SOUTHEAST OF UPPER MI MONDAY MORNING. BEHIND THIS TROUGH...WINDS
WILL VEER TO THE WEST AND INCREASE TO GALES TO 35 TO 40 KNOTS ACROSS
THE EAST HALF OF LAKE SUPERIOR MONDAY AFTERNOON AND EVENING. AFTER A
DECREASE TO 20 TO 30 KNOT SOUTHWEST WINDS TUESDAY MORNING...LOW
PRESSURE WILL TRACK EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND
PRODUCE WESTERLY WINDS OF UP TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON
AND EVENING. THE WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30
KNOTS FROM LATE TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE
EXTENDING FROM HIGH PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS
INTO THE AREA. CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE
POSSIBLE THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR
ACROSS THE LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE
SOUTHEASTWARD ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT
WINDS SHOULD REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS
SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WATCH FROM MONDAY MORNING THROUGH MONDAY
EVENING FOR MIZ001-003.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ THIS AFTERNOON
TO 7 AM EST /6 AM CST/ MONDAY FOR MIZ012-013.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 9 AM EST
MONDAY FOR MIZ007-014-085.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ264>267.
GALE WATCH FROM MONDAY AFTERNOON THROUGH MONDAY EVENING FOR
LSZ263.
GALE WATCH FROM MONDAY AFTERNOON THROUGH LATE MONDAY NIGHT FOR
LSZ244-245.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...VOSS
LONG TERM...KLUBER
AVIATION...JLB
MARINE...KLUBER
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
157 PM CST SUN DEC 8 2013
.DISCUSSION...
UPDATED TO DROP WINTER WEATHER ADVISORY ACROSS THE AREA. WITH
VISILIBITIES NOW AT OR ABOVE 2 SM IN MOST LOCATIONS...ONLY LIGHT
ACCUMULATIONS OF A COUPLE TENTHS OF AN INCH ARE EXPECTED.
SECONDARY BATCH OF SNOW CURRENTLY IN SOUTHEAST NEB IS PROGGED TO
WEAKEN AS IT APPROACHES EASTERN NEB...BUT IT MAY BRING YET ANOTHER
TENTH OR TWO OF SNOW. OVERALL...WITH THE ACCUMULATING SNOW
DIMINISHING...THE NEED FOR AN ADVISORY HAS DIMINISHED AS WELL.
WITH COMPACTION AND SETTLING OF SNOW...MOST LOCATIONS HAVE LIKELY
SEEN THEIR PEAK SNOW ACCUMULATIONS.
MAYES
&&
.PREV DISCUSSION... /ISSUED 1125 AM CST SUN DEC 8 2013/
AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
LIGHT TO MODERATE SNOW CONTINUES AT ALL SITES...BUT VIS AND
CEILINGS SHOULD GRADUALLY IMPROVE THROUGH THE AFTERNOON.
KOMA MAY HOLD ON TO SNOW UNTIL AT LEAST AROUND 00Z...BUT OTHER
SITES SHOULD TAPER TO FLURRIES BEFORE THEN. OVERNIGHT...CEILINGS
SHOULD DECREASE...WHILE WINDS WILL INCREASE OUT OF THE NORTHWEST.
HAVE ONLY BROUGHT WINDS ABOVE 12KT AT KOFK...WITH KOMA/KLNK AT
AROUND 10KT...AND WINDS SHOULD BEING TO DECREASE BY AROUND 18Z
MONDAY.
MAYES
PREV DISCUSSION... /ISSUED 854 AM CST SUN DEC 8 2013/
DISCUSSION...
HAVE UPDATED THE FORECAST...WITH THE BIGGEST CHANGE BEING THE
ADDITION OF PAWNEE AND RICHARDSON COUNTIES TO THE ADVISORY.
MODERATE SNOWFALL IS ONGOING THERE...AND THE POTENTIAL IS JUST AS
HIGH THERE FOR 2-3 INCHES OF SNOW AS MANY OTHER AREAS OF THE CWA.
ACTUALLY REDUCED POPS IN NORTHEAST NEB FOR A SHORT PERIOD THIS
LATE MORNING/EARLY AFTERNOON...WHERE THERE ARE LITTLE MORE THAN
FLURRIES NOW. ADJUSTED SNOW TOTALS DOWNWARD UP THERE...AND UPWARD
IN SOUTHEAST NEB. ALSO UPDATED TEMPERATURE AND DEWPOINT
TRENDS...AS TEMPS DID NOT FALL FAR OVERNIGHT AND HAVE BEEN STEADY
TO RISING.
MAYES
PREV DISCUSSION... /ISSUED 322 AM CST SUN DEC 8 2013/
DISCUSSION...
DURATION/COVERAGE/AMOUNTS OF SNOW THROUGH THIS EVENING ARE THE
PRIMARY FORECAST CHALLENGES.
SNOW DEVELOPED SATURDAY EVENING ACROSS MUCH OF SOUTHERN NEBRASKA
INCLUDING SOUTHEAST NEBRASKA...AND HAD SPREAD NORTH TO THE PLATTE
RIVER AND THE OMAHA METRO BY MIDNIGHT. THIS WAS SEVERAL HOURS
EARLIER THAN MODELS SHOWED 24 HOURS AGO WHEN THEY WERE PAINTING
SIGNIFICANT BOUNDARY LAYER DRY AIR THAT WOULD NOT BE OVERCOME UNTIL
AFTER MIDNIGHT FOR ALL BUT THE WESTERN CWA. ENHANCED LIFT IN RIGHT
ENTRANCE REGION OF UPPER JET OVERCAME THIS DRY AIR RATHER QUICKLY AS
RADAR RETURNS BLOSSOMED RAPIDLY SATURDAY EVENING IN SOUTH CENTRAL
THEN SOUTHEAST NEBRASKA. 00Z MODELS WERE NOT HANDLING THIS AREA OF
PRECIP WELL AT ALL...INSTEAD FOCUSING ON NORTHERN NEBRASKA BY 06Z.
HOWEVER MESOSCALE MODELS HRRR AND RAP WERE AT LEAST OFFERING BETTER
SOLUTIONS COMPARED TO CURRENT TRENDS.
UPPER TROUGH REMAINED WELL TO OUR WEST THIS MORNING...WITH BASE OF
TROUGH AXIS NEARING THE FOUR CORNERS REGION AT 08Z. A COUPLE OF
SHORTWAVES WERE NOTED IN WATER VAPOR IMAGERY...ONE ROUNDING BASE OF
TROUGH THAT WAS SHOWING ENHANCEMENT IN SOUTHERN ARIZONA...AND A
SECOND WAS SPINNING THROUGH CENTRAL COLORADO. THE FIRST SHORTWAVE
SUGGESTS A STRONG JET SEGMENT THAT WAS NOT HANDLED WELL BY
MODELS...AND EXTRAPOLATION PUTS THE LEFT EXIT REGION OF THAT JET
INTO NEBRASKA LATER THIS MORNING. THIS WILL AGAIN ENHANCE LIFT IN
OUR SOUTHERN/CENTRAL CWA. AND THE COLORADO VORT/SHORTWAVE IS PROGGED
TO WORK EAST INTO NEBRASKA THIS AFTERNOON BEFORE EXITING TO OUR EAST
BY 06Z. AHEAD OF BOTH SHORTWAVES WE WILL SEE CONTINUED ISENTROPIC
UPGLIDE THROUGH THE MORNING AND AFTERNOON BEFORE DOWNGLIDE BEGINS
FROM WEST TO EAST LATE IN THE DAY AND EVENING.
ISENTROPIC ANALYSIS ALONG THE 285K SURFACE INDICATES MIXING RATIOS
OF 2 G/KG WILL CONTINUE TO PUMP INTO OUR SOUTH AND CENTRAL CWA WHERE
LIFT IS EXPECTED TO BE STRONGEST. THIS TRANSLATES TO POTENTIALLY
ANOTHER 4 INCHES OF SNOW IN THOSE AREAS...PUTTING TOTALS IN THE 3 TO
6 INCH RANGE IN MOST OF THE SOUTHERN HALF OF THE CWA. IN THE
NORTHERN HALF AND ESPECIALLY NORTHEAST NEBRASKA...SNOW WAS SLOW TO
BEGIN BUT HAS ENHANCED MARKEDLY OVER THE PAST SEVERAL HOURS. REPORTS
OF AN INCH OR TWO HAVE COME IN FROM NEAR THE SOUTH DAKOTA
BORDER...WITH LESSER AMOUNTS TO THE SOUTH. LIFT IN THAT AREA DOES
NOT LOOK AS STRONG AS TO THE SOUTH...BUT AMOUNTS COULD STILL
APPROACH 3 INCHES BEFORE ENDING. ALREADY HAVE A WINTER WEATHER
ADVISORY GOING FOR MOST OF THE CWA. SOUTHERN AREAS SHOULD EASILY
VERIFY THIS...BUT NORTHERN AREAS COULD STRUGGLE TO REACH THE LOWER
END OF CRITERIA. HOWEVER WILL MAINTAIN ADVISORY FOR ALL CURRENT
AREAS AS SNOW IS JUST GETTING GOING IN OUR NORTH AND EXPECT SOME
ENHANCEMENT DURING THE MORNING.
SNOW SHOULD BE TAPERING IN OUR WEST BY MID AFTERNOON...THEN EASTERN
SECTIONS THIS EVENING. CLEARING SKIES AND FRESH SNOW COVER WILL
ALLOW TEMPERATURES TO DROP BELOW ZERO IN MUCH OF THE CWA. NORTHWEST
WINDS OF 10 TO 15 MPH SHOULD DEVELOP LATER TONIGHT AND MONDAY
MORNING...AND WITH SUB ZERO TEMPERATURES...WIND CHILLS WILL APPROACH
20 BELOW FOR THE START OF THE SCHOOL/WORK WEEK. WILL GO AHEAD AND
ISSUE A WIND CHILL ADVISORY FOR A GOOD PART OF OUR NORTHERN CWA
FOR LATE TONIGHT AND MONDAY MORNING.
ANOTHER SHORTWAVE WILL DIVE INTO THE GREAT LAKES MONDAY
NIGHT...CAUSING SURFACE FLOW TO BECOME SOUTHWESTERLY HERE MONDAY
AFTERNOON. BUT COLD START AND SNOW WILL KEEP HIGHS ONLY IN THE
TEENS. THEN A CLIPPER SYSTEM/SHORTWAVE IS FORECAST THROUGH NORTHEAST
NEBRASKA INTO IOWA TUESDAY NIGHT. AGAIN THIS WILL BRING WEST TO
SOUTHWEST WINDS TO OUR AREA MONDAY NIGHT AND TUESDAY...KEEPING LOWS
ABOVE ZERO AND PUSHING HIGHS INTO THE 20S. MODELS HAVE BEEN
PERSISTENT IN DROPPING A STRIPE OF LIGHT SNOW WITH THIS SYSTEM
TUESDAY NIGHT INTO WEDNESDAY MORNING...SO WILL INSERT SMALL CHANCES
FOR THIS IN OUR NORTHEAST CWA. MUCH COLDER AIR BEHIND THE CLIPPER
WILL KEEP HIGHS IN THE TEENS ON WEDNESDAY. THEN A GRADUAL WARMING
TREND LOOKS ON TRACK FOR THURSDAY INTO SATURDAY AS UPPER FLOW
TRANSITIONS FROM A NORTHWEST TO ZONAL SETUP. HAVE HIGHS CLOSE TO 30
EACH DAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR NEZ011-012-
015>018-030>034-042>045.
IA...WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR IAZ043-055.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS OMAHA/VALLEY NE
1125 AM CST SUN DEC 8 2013
.AVIATION...
18Z TAFS FOR KOMA...KLNK...AND KOFK.
LIGHT TO MODERATE SNOW CONTINUES AT ALL SITES...BUT VIS AND
CEILINGS SHOULD GRADUALLY IMPROVE THROUGH THE AFTERNOON.
KOMA MAY HOLD ON TO SNOW UNTIL AT LEAST AROUND 00Z...BUT OTHER
SITES SHOULD TAPER TO FLURRIES BEFORE THEN. OVERNIGHT...CEILINGS
SHOULD DECREASE...WHILE WINDS WILL INCREASE OUT OF THE NORTHWEST.
HAVE ONLY BROUGHT WINDS ABOVE 12KT AT KOFK...WITH KOMA/KLNK AT
AROUND 10KT...AND WINDS SHOULD BEING TO DECREASE BY AROUND 18Z
MONDAY.
MAYES
&&
.PREV DISCUSSION... /ISSUED 854 AM CST SUN DEC 8 2013/
DISCUSSION...
HAVE UPDATED THE FORECAST...WITH THE BIGGEST CHANGE BEING THE
ADDITION OF PAWNEE AND RICHARDSON COUNTIES TO THE ADVISORY.
MODERATE SNOWFALL IS ONGOING THERE...AND THE POTENTIAL IS JUST AS
HIGH THERE FOR 2-3 INCHES OF SNOW AS MANY OTHER AREAS OF THE CWA.
ACTUALLY REDUCED POPS IN NORTHEAST NEB FOR A SHORT PERIOD THIS
LATE MORNING/EARLY AFTERNOON...WHERE THERE ARE LITTLE MORE THAN
FLURRIES NOW. ADJUSTED SNOW TOTALS DOWNWARD UP THERE...AND UPWARD
IN SOUTHEAST NEB. ALSO UPDATED TEMPERATURE AND DEWPOINT
TRENDS...AS TEMPS DID NOT FALL FAR OVERNIGHT AND HAVE BEEN STEADY
TO RISING.
MAYES
PREV DISCUSSION... /ISSUED 322 AM CST SUN DEC 8 2013/
DISCUSSION...
DURATION/COVERAGE/AMOUNTS OF SNOW THROUGH THIS EVENING ARE THE
PRIMARY FORECAST CHALLENGES.
SNOW DEVELOPED SATURDAY EVENING ACROSS MUCH OF SOUTHERN NEBRASKA
INCLUDING SOUTHEAST NEBRASKA...AND HAD SPREAD NORTH TO THE PLATTE
RIVER AND THE OMAHA METRO BY MIDNIGHT. THIS WAS SEVERAL HOURS
EARLIER THAN MODELS SHOWED 24 HOURS AGO WHEN THEY WERE PAINTING
SIGNIFICANT BOUNDARY LAYER DRY AIR THAT WOULD NOT BE OVERCOME UNTIL
AFTER MIDNIGHT FOR ALL BUT THE WESTERN CWA. ENHANCED LIFT IN RIGHT
ENTRANCE REGION OF UPPER JET OVERCAME THIS DRY AIR RATHER QUICKLY AS
RADAR RETURNS BLOSSOMED RAPIDLY SATURDAY EVENING IN SOUTH CENTRAL
THEN SOUTHEAST NEBRASKA. 00Z MODELS WERE NOT HANDLING THIS AREA OF
PRECIP WELL AT ALL...INSTEAD FOCUSING ON NORTHERN NEBRASKA BY 06Z.
HOWEVER MESOSCALE MODELS HRRR AND RAP WERE AT LEAST OFFERING BETTER
SOLUTIONS COMPARED TO CURRENT TRENDS.
UPPER TROUGH REMAINED WELL TO OUR WEST THIS MORNING...WITH BASE OF
TROUGH AXIS NEARING THE FOUR CORNERS REGION AT 08Z. A COUPLE OF
SHORTWAVES WERE NOTED IN WATER VAPOR IMAGERY...ONE ROUNDING BASE OF
TROUGH THAT WAS SHOWING ENHANCEMENT IN SOUTHERN ARIZONA...AND A
SECOND WAS SPINNING THROUGH CENTRAL COLORADO. THE FIRST SHORTWAVE
SUGGESTS A STRONG JET SEGMENT THAT WAS NOT HANDLED WELL BY
MODELS...AND EXTRAPOLATION PUTS THE LEFT EXIT REGION OF THAT JET
INTO NEBRASKA LATER THIS MORNING. THIS WILL AGAIN ENHANCE LIFT IN
OUR SOUTHERN/CENTRAL CWA. AND THE COLORADO VORT/SHORTWAVE IS PROGGED
TO WORK EAST INTO NEBRASKA THIS AFTERNOON BEFORE EXITING TO OUR EAST
BY 06Z. AHEAD OF BOTH SHORTWAVES WE WILL SEE CONTINUED ISENTROPIC
UPGLIDE THROUGH THE MORNING AND AFTERNOON BEFORE DOWNGLIDE BEGINS
FROM WEST TO EAST LATE IN THE DAY AND EVENING.
ISENTROPIC ANALYSIS ALONG THE 285K SURFACE INDICATES MIXING RATIOS
OF 2 G/KG WILL CONTINUE TO PUMP INTO OUR SOUTH AND CENTRAL CWA WHERE
LIFT IS EXPECTED TO BE STRONGEST. THIS TRANSLATES TO POTENTIALLY
ANOTHER 4 INCHES OF SNOW IN THOSE AREAS...PUTTING TOTALS IN THE 3 TO
6 INCH RANGE IN MOST OF THE SOUTHERN HALF OF THE CWA. IN THE
NORTHERN HALF AND ESPECIALLY NORTHEAST NEBRASKA...SNOW WAS SLOW TO
BEGIN BUT HAS ENHANCED MARKEDLY OVER THE PAST SEVERAL HOURS. REPORTS
OF AN INCH OR TWO HAVE COME IN FROM NEAR THE SOUTH DAKOTA
BORDER...WITH LESSER AMOUNTS TO THE SOUTH. LIFT IN THAT AREA DOES
NOT LOOK AS STRONG AS TO THE SOUTH...BUT AMOUNTS COULD STILL
APPROACH 3 INCHES BEFORE ENDING. ALREADY HAVE A WINTER WEATHER
ADVISORY GOING FOR MOST OF THE CWA. SOUTHERN AREAS SHOULD EASILY
VERIFY THIS...BUT NORTHERN AREAS COULD STRUGGLE TO REACH THE LOWER
END OF CRITERIA. HOWEVER WILL MAINTAIN ADVISORY FOR ALL CURRENT
AREAS AS SNOW IS JUST GETTING GOING IN OUR NORTH AND EXPECT SOME
ENHANCEMENT DURING THE MORNING.
SNOW SHOULD BE TAPERING IN OUR WEST BY MID AFTERNOON...THEN EASTERN
SECTIONS THIS EVENING. CLEARING SKIES AND FRESH SNOW COVER WILL
ALLOW TEMPERATURES TO DROP BELOW ZERO IN MUCH OF THE CWA. NORTHWEST
WINDS OF 10 TO 15 MPH SHOULD DEVELOP LATER TONIGHT AND MONDAY
MORNING...AND WITH SUB ZERO TEMPERATURES...WIND CHILLS WILL APPROACH
20 BELOW FOR THE START OF THE SCHOOL/WORK WEEK. WILL GO AHEAD AND
ISSUE A WIND CHILL ADVISORY FOR A GOOD PART OF OUR NORTHERN CWA
FOR LATE TONIGHT AND MONDAY MORNING.
ANOTHER SHORTWAVE WILL DIVE INTO THE GREAT LAKES MONDAY
NIGHT...CAUSING SURFACE FLOW TO BECOME SOUTHWESTERLY HERE MONDAY
AFTERNOON. BUT COLD START AND SNOW WILL KEEP HIGHS ONLY IN THE
TEENS. THEN A CLIPPER SYSTEM/SHORTWAVE IS FORECAST THROUGH NORTHEAST
NEBRASKA INTO IOWA TUESDAY NIGHT. AGAIN THIS WILL BRING WEST TO
SOUTHWEST WINDS TO OUR AREA MONDAY NIGHT AND TUESDAY...KEEPING LOWS
ABOVE ZERO AND PUSHING HIGHS INTO THE 20S. MODELS HAVE BEEN
PERSISTENT IN DROPPING A STRIPE OF LIGHT SNOW WITH THIS SYSTEM
TUESDAY NIGHT INTO WEDNESDAY MORNING...SO WILL INSERT SMALL CHANCES
FOR THIS IN OUR NORTHEAST CWA. MUCH COLDER AIR BEHIND THE CLIPPER
WILL KEEP HIGHS IN THE TEENS ON WEDNESDAY. THEN A GRADUAL WARMING
TREND LOOKS ON TRACK FOR THURSDAY INTO SATURDAY AS UPPER FLOW
TRANSITIONS FROM A NORTHWEST TO ZONAL SETUP. HAVE HIGHS CLOSE TO 30
EACH DAY.
DERGAN
&&
.OAX WATCHES/WARNINGS/ADVISORIES...
NE...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR NEZ011-
012-015>018-030>034-042>045-050>053-065>068-078-088>093.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR NEZ011-012-
015>018-030>034-042>045.
IA...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ043-
055-056-069-079-080-090-091.
WIND CHILL ADVISORY FROM 3 AM TO NOON CST MONDAY FOR IAZ043-055.
&&
$$
99/99
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
101 PM MST SUN DEC 8 2013
.UPDATE...
UPDATED TO CANCEL WIND AND WINTER WEATHER HIGHLIGHTS. FRONTAL BAND
HAS WEAKENED SIGNIFICANTLY AS IT MOVED WELL SOUTH OF THE UPPER
LEVEL FORCING OVER COLORADO. SFC COLD FRONT IS NOW MAINLY A
STALLED WEST TO EAST ORIENTED TEMPERATURE BOUNDARY FROM QUEMADO TO
SOCORRO TO CLINES CORNERS TO JUST N/NW OF TUCUMCARI. ISOALTED SNOW
SHOWERS WILL CONTINUE OVER THE WESTERN HIGHLANDS AND MTNS AND OVER THE
CENTRAL HIGHLANDS THROUGH THE AFTERNOON. THE STALLED SFC FRONT DRAPED FROM
WEST TO EAST EXPECTED TO SET THE STAGE FOR MONDAY.
33
&&
.PREV DISCUSSION...1055 AM MST SUN DEC 8 2013...
.AVIATION...
18Z TAF CYCLE
LIFR CONDITIONS IN FREEZING FOG AT KROW TO IMPROVE TO VFR BY 20Z
THEN REMAIN VFR THROUGH THE TAF PERIOD WITH THE POTENTIAL FOR MVFR
CONDITIONS MONDAY MORNING. VFR CONDITIONS FORECAST TO PERSIST AT
KFMN...BUT MORE COMPLEX FORECAST FOR KGUP...KABQ...KAEG...KSAF AND
KTCC AS ANOTHER SHORTWAVE TROUGH DROPS INTO THE REGION OVERNIGHT
THROUGH MONDAY. LIGHT SNOW WITH MVFR CIGS/VSBYS FORECAST TO
DEVELOP OVERNIGHT...WITH IFR CONDITIONS POSSIBLE. IMPROVEMENT...
IF ANY...MONDAY MORNING WILL BE SLOW AT KGUP...KABQ...KAEG AND
KSAF. LIKELY AN ALL-DAY SCENARIO AT KTCC WITH DETERIORATING
CONDITIONS. WIND GUSTS TO BETWEEN 35-40KTS AT KLVS AND KTCC THIS
AFTERNOON WILL DIMINISH QUICKLY BY EARLY EVENING.
11
.PREV DISCUSSION...338 AM MST SUN DEC 8 2013...
...STRONGER WINDS AND FRIGID TEMPERATURES TODAY/MONDAY WILL MAKE
FOR THE COLDEST DAYS OF THE ARCTIC STRETCH...
MID-LEVEL SPEED MAX OF 60-80 KNOTS WITHIN BASE OF A
POTENT UPPER LEVEL SHORTWAVE TROUGH TO TRANSLATE EASTWARD OVER
THE AREA TODAY. VERY COLD AIR ALOFT CONTRIBUTING TO A BEAUTIFUL
SATELLITE PRESENTATION EARLY THIS MORNING. COOLING CLOUD TOPS
EVIDENT OVER FAR NW/NC AREAS WHERE CONVECTIVE SNOW BURSTS LIKELY
PRODUCING SHORT-DURATION INTENSE SNOW OVER THE HIGHER TERRAIN FROM
JUST EAST-NORTHEAST OF FARMINGTON TO CHAMA AND AREAS JUST SOUTH.
CHAMA HAD 4 INCHES OF SNOW AS OF MID-EVENING SATURDAY PRIOR TO
THESE MORE FAVORABLE CONDITIONS THAT WILL SHIFT TOWARD THE SANGRES.
OTHERWISE...TRANSITION TO INCREASINGLY OROGRAPHIC SNOWS EXPECTED AS
THE MORNING PROGRESSES WITH BANDED SNOW STRUCTURE EXPECTED ALONG A
SURFACE TO MID- LEVEL FRONTAL ZONE THAT WILL CONTINUE TO PRESS
EAST- SOUTHEAST AND FAVOR WC AREAS ESPECIALLY NEAR THE DIVIDE.
COULD SEE THE REMNANTS OF THIS BAND REACH THE ABQ AREA BY MID- TO
LATE MORNING PER THE LATEST HRRR BUT NOT EXPECTING MUCH IMPACT. OF
GREATER IMPACT FOR MOST AREAS WILL BE INCREASING WIND AND COMBINED
WITH FRIGID TEMPERATURES WILL MAKE IT BRUTAL FOR MUCH OF THE NORTH
AND WEST. DOWNSLOPING WINDS FOR THE FIRST TIME IN MANY DAYS SHOULD
ACTUALLY HELP IMPROVE CONDITIONS ACROSS THE EASTERN PLAINS WHERE
LOW CLOUDS...FREEZING FOG/DRIZZLE WILL CONTINUE THROUGH THE
MORNING ACROSS ROUGHLY THE SOUTHEAST QUARTER. BLOWING SNOW IMPACTS
COULD BE SIGNIFICANT FOR AREAS THAT RECEIVED HEAVY SNOW THIS PAST
THURSDAY AND ARE WELL REMOVED FROM WHERE THE SNOW ACTUALLY FALLS
TODAY.
ANOTHER VERY INTERESTING/CHALLENGING FORECAST TONIGHT INTO MONDAY.
AS THE NEXT REINFORCING AND COLDEST CHUNK OF ARCTIC AIR PLUNGES
SOUTH. AND IT WILL DO SO VERY SIMILAR TO HOW THE INITIAL BLAST
PLAYED OUT LAST THURSDAY. THAT IS BREAKING DOWN BOTH SIDES OF THE
DIVIDE. THERE WILL BE A BACKDOOR SEGMENT THAT WILL PUSH SOUTH AND
WEST A LITTLE FASTER THAN THE REINFORCING SURGE OF ARCTIC AIR
ACROSS WESTERN NEW MEXICO. AT THE SAME TIME...A POSITIVELY TILTED
UPPER TROUGH WILL BE SAGGING SOUTH-SOUTHEAST OVER THE AREA. THE
GFS HAS BEEN TARGETING A MESOSCALE BAND OF SNOW AHEAD OF THE UPPER
TROUGH AND ALONG THE SOUTHWARD- MOVING ARCTIC REINFORCEMENT MUCH
FARTHER WEST AND NORTH COMPARED TO ITS COUNTERPARTS. ECMWF AND
ESPECIALLY THE NAM ARE CONSIDERABLY DRIER AND FOCUS MOST THEIR QPF
FROM EAST- CENTRAL INTO SOUTH- CENTRAL NEW MEXICO. WHERE THIS
BANDS SET UP WILL LIKELY MEAN THE DIFFERENCE BETWEEN A HIGH-END
ADVISORY FOR SEVERAL INCHES OF SNOW OR NO ADVISORY. FOR NOW HAVE
KEPT WITH PREVIOUS STRONG TREND TOWARD THE GFS. BOTTOM LINE...WE
ARE NOT DONE WITH SNOW IMPACTS.
THEREAFTER...A BRUTALLY COLD PATTERN MONDAY NIGHT ESPECIALLY WITH
FRESH SNOW COVER AND CLEARING SKIES FOR SOME AREAS. OTHERWISE A
QUIET PATTERN FINALLY INDICATED INTO TUESDAY WITH ANY LINGERING
SNOW ENDING FROM EAST TO WEST. WE WILL FINALLY BEGIN TO MAKE THE
TURN BY THE MIDDLE PART OF THE WEEK BUT STILL UNCERTAINTY
REGARDING HOW A LOW LATITUDE LOW MAY EVOLVE FOR THE LATE WEEK
PERIOD. KJ
.FIRE WEATHER...
NOW HAS BEGUN ACROSS THE NORTH AND WEST THIS MORNING AS AN UPPER
LEVEL TROUGH SWINGS OVER NM. VERY HIGH SNOW RATIOS EXPECTED WITH
THIS COLD AIRMASS...AND SEVERAL INCHES OF SNOW HAS ALREADY BEEN
REPORTED ACROSS THE SAN JUAN MOUNTAINS. COLD FRONT IS MARCHING INTO
NORTHWEST NM AND IS CURRENTLY THROUGH FARMINGTON AND GALLUP. THIS
FRONT WILL CONTINUE TO SWEEP EASTWARD TODAY CREATING WINDY
CONDITIONS BEHIND IT...ESPECIALLY ACROSS THE CENTRAL MOUNTAIN CHAIN
AND ADJACENT HIGHLANDS TO THE EAST. THE INCREASE IN WIND SPEED WILL
RESULT IN VERY GOOD TO EXCELLENT VENTILATION FOR ALL BUT THE
SOUTHERN PORTIONS OF THE RIO GRANDE VALLEY AND THE EAST CENTRAL
PLAINS. ALSO BECAUSE OF THE WINDS...SPECIFICALLY THE DOWNSLOPE
COMPONENT ACROSS THE EAST...TEMPERATURES ARE EXPECTED TO WARM ABOVE
THE FREEZING MARK FOR THE FIRST TIME IN SEVERAL DAYS...THOUGH MOST
AREAS WILL REMAIN 10 TO 20 DEGREES BELOW NORMAL.
THE WARM-UP TODAY WILL BE SHORT-LIVED AS MUCH COLDER AIR FILTERS
INTO THE AREA TONIGHT...AND MOST AREAS ON MONDAY WILL STRUGGLE TO
REACH THE FREEZING MARK. A SECONDARY TROUGH WILL SWING OVER THE
STATE ON MONDAY AS WELL...AND OPERATIONAL MODELS ARE STILL AT ODDS
WITH PRECIPITATION POTENTIAL. HOWEVER...GFS ENSEMBLE GUIDANCE
INCREASES CONFIDENCE THAT THERE WILL BE A BAND OF SNOW DEVELOPING
ALONG A FRONT STRETCHING FROM THE SW MTNS TOWARD THE SANDIA/MANZANO
MOUNTAINS. ADDITIONALLY...CONVERGENCE DUE TO THE BACK DOOR SEGMENT
OF THE FRONT MAY ENHANCE SNOWFALL POTENTIAL OVER THE CENTRAL AND
SOUTH CENTRAL HIGHLANDS. SHOULD THIS OCCUR A COUPLE INCHES OF SNOW
ARE POSSIBLE...THOUGH IT SHOULD BE MENTIONED THAT THE NAM AND ECMWF
MODELS SHOW VERY LITTLE QPF...IF ANY.
WINDS DUE TO THE FRONT WILL KEEP VENT RATES IN THE GOOD TO VERY GOOD
CATEGORY MONDAY ACROSS THE CENTRAL AND WEST...WITH POOR VENTILATION
PREVAILING ACROSS THE EAST.
COOL NORTHWEST FLOW WILL BE IN STORE FOR TUESDAY AND WEDNESDAY...AND
TEMPERATURES WILL REMAIN UP TO 20 DEGREES BELOW NORMAL. GENERALLY
LIGHT WINDS AND POOR MIXING WILL RESULT IN POOR VENTILATION
AREAWIDE. HOWEVER...A BACK DOOR COLD FRONT WILL SLIDE DOWN THE
PLAINS ON WEDNESDAY.
MODELS SHOW A DISTURBANCE MOVING ACROSS THE AREA ON
THURSDAY...THOUGH IT IS UNCLEAR WHERE...IF ANY...PRECIPITATION
OCCURS WITH THIS SYSTEM. MIXING WILL REMAIN POOR...THUS SO WILL
VENTILATION. THE UPPER AIR PATTERN LOOKS TO REMAIN ACTIVE BEYOND
THURSDAY...THOUGH MODELS DIVERGE ON PLACEMENT AND TIMING OF STORM
SYSTEMS. 34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
33
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1055 AM MST SUN DEC 8 2013
.AVIATION...
18Z TAF CYCLE
LIFR CONDITIONS IN FREEZING FOG AT KROW TO IMPROVE TO VFR BY 20Z
THEN REMAIN VFR THROUGH THE TAF PERIOD WITH THE POTENTIAL FOR MVFR
CONDITIONS MONDAY MORNING. VFR CONDITIONS FORECAST TO PERSIST AT
KFMN...BUT MORE COMPLEX FORECAST FOR KGUP...KABQ...KAEG...KSAF AND
KTCC AS ANOTHER SHORTWAVE TROUGH DROPS INTO THE REGION OVERNIGHT
THROUGH MONDAY. LIGHT SNOW WITH MVFR CIGS/VSBYS FORECAST TO
DEVELOP OVERNIGHT...WITH IFR CONDITIONS POSSIBLE. IMPROVEMENT...
IF ANY...MONDAY MORNING WILL BE SLOW AT KGUP...KABQ...KAEG AND
KSAF. LIKELY AN ALL-DAY SCENARIO AT KTCC WITH DETERIORATING
CONDITIONS. WIND GUSTS TO BETWEEN 35-40KTS AT KLVS AND KTCC THIS
AFTERNOON WILL DIMINISH QUICKLY BY EARLY EVENING.
11
&&
.PREV DISCUSSION...338 AM MST SUN DEC 8 2013...
...STRONGER WINDS AND FRIGID TEMPERATURES TODAY/MONDAY WILL MAKE
FOR THE COLDEST DAYS OF THE ARCTIC STRETCH...
MID-LEVEL SPEED MAX OF 60-80 KNOTS WITHIN BASE OF A
POTENT UPPER LEVEL SHORTWAVE TROUGH TO TRANSLATE EASTWARD OVER
THE AREA TODAY. VERY COLD AIR ALOFT CONTRIBUTING TO A BEAUTIFUL
SATELLITE PRESENTATION EARLY THIS MORNING. COOLING CLOUD TOPS
EVIDENT OVER FAR NW/NC AREAS WHERE CONVECTIVE SNOW BURSTS LIKELY
PRODUCING SHORT-DURATION INTENSE SNOW OVER THE HIGHER TERRAIN FROM
JUST EAST-NORTHEAST OF FARMINGTON TO CHAMA AND AREAS JUST SOUTH.
CHAMA HAD 4 INCHES OF SNOW AS OF MID-EVENING SATURDAY PRIOR TO
THESE MORE FAVORABLE CONDITIONS THAT WILL SHIFT TOWARD THE SANGRES.
OTHERWISE...TRANSITION TO INCREASINGLY OROGRAPHIC SNOWS EXPECTED AS
THE MORNING PROGRESSES WITH BANDED SNOW STRUCTURE EXPECTED ALONG A
SURFACE TO MID- LEVEL FRONTAL ZONE THAT WILL CONTINUE TO PRESS
EAST- SOUTHEAST AND FAVOR WC AREAS ESPECIALLY NEAR THE DIVIDE.
COULD SEE THE REMNANTS OF THIS BAND REACH THE ABQ AREA BY MID- TO
LATE MORNING PER THE LATEST HRRR BUT NOT EXPECTING MUCH IMPACT. OF
GREATER IMPACT FOR MOST AREAS WILL BE INCREASING WIND AND COMBINED
WITH FRIGID TEMPERATURES WILL MAKE IT BRUTAL FOR MUCH OF THE NORTH
AND WEST. DOWNSLOPING WINDS FOR THE FIRST TIME IN MANY DAYS SHOULD
ACTUALLY HELP IMPROVE CONDITIONS ACROSS THE EASTERN PLAINS WHERE
LOW CLOUDS...FREEZING FOG/DRIZZLE WILL CONTINUE THROUGH THE
MORNING ACROSS ROUGHLY THE SOUTHEAST QUARTER. BLOWING SNOW IMPACTS
COULD BE SIGNIFICANT FOR AREAS THAT RECEIVED HEAVY SNOW THIS PAST
THURSDAY AND ARE WELL REMOVED FROM WHERE THE SNOW ACTUALLY FALLS
TODAY.
ANOTHER VERY INTERESTING/CHALLENGING FORECAST TONIGHT INTO MONDAY.
AS THE NEXT REINFORCING AND COLDEST CHUNK OF ARCTIC AIR PLUNGES
SOUTH. AND IT WILL DO SO VERY SIMILAR TO HOW THE INITIAL BLAST
PLAYED OUT LAST THURSDAY. THAT IS BREAKING DOWN BOTH SIDES OF THE
DIVIDE. THERE WILL BE A BACKDOOR SEGMENT THAT WILL PUSH SOUTH AND
WEST A LITTLE FASTER THAN THE REINFORCING SURGE OF ARCTIC AIR
ACROSS WESTERN NEW MEXICO. AT THE SAME TIME...A POSITIVELY TILTED
UPPER TROUGH WILL BE SAGGING SOUTH-SOUTHEAST OVER THE AREA. THE
GFS HAS BEEN TARGETING A MESOSCALE BAND OF SNOW AHEAD OF THE UPPER
TROUGH AND ALONG THE SOUTHWARD- MOVING ARCTIC REINFORCEMENT MUCH
FARTHER WEST AND NORTH COMPARED TO ITS COUNTERPARTS. ECMWF AND
ESPECIALLY THE NAM ARE CONSIDERABLY DRIER AND FOCUS MOST THEIR QPF
FROM EAST- CENTRAL INTO SOUTH- CENTRAL NEW MEXICO. WHERE THIS
BANDS SET UP WILL LIKELY MEAN THE DIFFERENCE BETWEEN A HIGH-END
ADVISORY FOR SEVERAL INCHES OF SNOW OR NO ADVISORY. FOR NOW HAVE
KEPT WITH PREVIOUS STRONG TREND TOWARD THE GFS. BOTTOM LINE...WE
ARE NOT DONE WITH SNOW IMPACTS.
THEREAFTER...A BRUTALLY COLD PATTERN MONDAY NIGHT ESPECIALLY WITH
FRESH SNOW COVER AND CLEARING SKIES FOR SOME AREAS. OTHERWISE A
QUIET PATTERN FINALLY INDICATED INTO TUESDAY WITH ANY LINGERING
SNOW ENDING FROM EAST TO WEST. WE WILL FINALLY BEGIN TO MAKE THE
TURN BY THE MIDDLE PART OF THE WEEK BUT STILL UNCERTAINTY
REGARDING HOW A LOW LATITUDE LOW MAY EVOLVE FOR THE LATE WEEK
PERIOD. KJ
.FIRE WEATHER...
NOW HAS BEGUN ACROSS THE NORTH AND WEST THIS MORNING AS AN UPPER
LEVEL TROUGH SWINGS OVER NM. VERY HIGH SNOW RATIOS EXPECTED WITH
THIS COLD AIRMASS...AND SEVERAL INCHES OF SNOW HAS ALREADY BEEN
REPORTED ACROSS THE SAN JUAN MOUNTAINS. COLD FRONT IS MARCHING INTO
NORTHWEST NM AND IS CURRENTLY THROUGH FARMINGTON AND GALLUP. THIS
FRONT WILL CONTINUE TO SWEEP EASTWARD TODAY CREATING WINDY
CONDITIONS BEHIND IT...ESPECIALLY ACROSS THE CENTRAL MOUNTAIN CHAIN
AND ADJACENT HIGHLANDS TO THE EAST. THE INCREASE IN WIND SPEED WILL
RESULT IN VERY GOOD TO EXCELLENT VENTILATION FOR ALL BUT THE
SOUTHERN PORTIONS OF THE RIO GRANDE VALLEY AND THE EAST CENTRAL
PLAINS. ALSO BECAUSE OF THE WINDS...SPECIFICALLY THE DOWNSLOPE
COMPONENT ACROSS THE EAST...TEMPERATURES ARE EXPECTED TO WARM ABOVE
THE FREEZING MARK FOR THE FIRST TIME IN SEVERAL DAYS...THOUGH MOST
AREAS WILL REMAIN 10 TO 20 DEGREES BELOW NORMAL.
THE WARM-UP TODAY WILL BE SHORT-LIVED AS MUCH COLDER AIR FILTERS
INTO THE AREA TONIGHT...AND MOST AREAS ON MONDAY WILL STRUGGLE TO
REACH THE FREEZING MARK. A SECONDARY TROUGH WILL SWING OVER THE
STATE ON MONDAY AS WELL...AND OPERATIONAL MODELS ARE STILL AT ODDS
WITH PRECIPITATION POTENTIAL. HOWEVER...GFS ENSEMBLE GUIDANCE
INCREASES CONFIDENCE THAT THERE WILL BE A BAND OF SNOW DEVELOPING
ALONG A FRONT STRETCHING FROM THE SW MTNS TOWARD THE SANDIA/MANZANO
MOUNTAINS. ADDITIONALLY...CONVERGENCE DUE TO THE BACK DOOR SEGMENT
OF THE FRONT MAY ENHANCE SNOWFALL POTENTIAL OVER THE CENTRAL AND
SOUTH CENTRAL HIGHLANDS. SHOULD THIS OCCUR A COUPLE INCHES OF SNOW
ARE POSSIBLE...THOUGH IT SHOULD BE MENTIONED THAT THE NAM AND ECMWF
MODELS SHOW VERY LITTLE QPF...IF ANY.
WINDS DUE TO THE FRONT WILL KEEP VENT RATES IN THE GOOD TO VERY GOOD
CATEGORY MONDAY ACROSS THE CENTRAL AND WEST...WITH POOR VENTILATION
PREVAILING ACROSS THE EAST.
COOL NORTHWEST FLOW WILL BE IN STORE FOR TUESDAY AND WEDNESDAY...AND
TEMPERATURES WILL REMAIN UP TO 20 DEGREES BELOW NORMAL. GENERALLY
LIGHT WINDS AND POOR MIXING WILL RESULT IN POOR VENTILATION
AREAWIDE. HOWEVER...A BACK DOOR COLD FRONT WILL SLIDE DOWN THE
PLAINS ON WEDNESDAY.
MODELS SHOW A DISTURBANCE MOVING ACROSS THE AREA ON
THURSDAY...THOUGH IT IS UNCLEAR WHERE...IF ANY...PRECIPITATION
OCCURS WITH THIS SYSTEM. MIXING WILL REMAIN POOR...THUS SO WILL
VENTILATION. THE UPPER AIR PATTERN LOOKS TO REMAIN ACTIVE BEYOND
THURSDAY...THOUGH MODELS DIVERGE ON PLACEMENT AND TIMING OF STORM
SYSTEMS. 34
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 AM TO 11 PM MST MONDAY FOR THE
FOLLOWING ZONES...NMZ518>526-529-531>539.
WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ521>524-526>529-533-539-540.
WINTER WEATHER ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE
FOLLOWING ZONES...NMZ501-502-504>506-511-512-515>517.
WINTER WEATHER ADVISORY FROM 2 AM TO 4 PM MST MONDAY FOR THE
FOLLOWING ZONES...NMZ505>509.
WINTER STORM WARNING UNTIL 4 PM MST THIS AFTERNOON FOR THE
FOLLOWING ZONES...NMZ503-510-513-514.
&&
$$
33
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
148 PM EST SUN DEC 8 2013
.SYNOPSIS...
CHILLY AND DAMP CONDITIONS WILL PREVAIL TODAY BEFORE A WARM FRONT
BRINGS A SHORT-LIVED WARM-UP ON MONDAY. A STRONG COLD FRONT WILL
MOVE ACROSS THE AREA TUESDAY...BRINGING A REINFORCEMENT OF COOLER
AIR THROUGH MID WEEK. ANOTHER STORM SYSTEM MAY BRING RAIN TO THE
REGION NEXT WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1025 AM SUNDAY...PERSISTENCE EMPLOYED FOR THE NEAR TERM
UPDATE AS THE METEOROLOGICAL SET-UP SUPPORTS A COOL AND WET REGIME
TO PREVAIL ALL DAY AND OVERNIGHT. NEAR TERM MODEL DATA HOWEVER
POINTS TO ATYPICAL TEMPERATURE CURVES TONIGHT...WITH A SLOW CLIMB
FROM THE MIDDLE AND UPPER 40S TO AROUND 50 DEGREES BY DAYBREAK
MONDAY AS SW FLOW ALOFT STRENGTHENS AND SCOURS THE SHALLOW AND
COOL WEDGE OF MARITIME INFLUENCE. HOW QUICKLY THIS OCCURS REMAINS
UP FOR ASSESSMENT...BUT IT APPEARS THE WEDGE WILL REMAIN
ENTRENCHED OVER THE FORECAST AREA THROUGH DAYBREAK MONDAY. THIS
MAKE TEMP AND WIND FORECASTS A BIT MORE PREDICTABLE THAN THE
TRANSITION OF WARMING ON MONDAY MORNING. MAXIMUM TEMPERATURES AS A
RESULT WILL LIKELY OCCUR FOR TODAYS 24 HOUR CALENDER PERIOD JUST
PRIOR TO 12Z/7AM MONDAY MORNING.
PRECIPITATION-WISE THE OVER-RUNNING WEDGE PATTERN WILL SUPPORT
OCCASIONAL DRIZZLE AREA-WIDE THROUGH TONIGHT. IN FACT AS THE WARM
FRONTAL TYPE PROCESS GEARS UP EARLY ON MONDAY...AREAS OF DENSE FOG
AND DRIZZLE MAY EXPAND OVER THE FORECAST AREA TO START THE WEEK.
P-TYPE ANALYSIS SHOWS THAT BOTH STRATIFORM AND CONVECTIVE TYPE
RAINFALL WILL PREVAIL OVER THE AREA THROUGH TONIGHT...BUT NOT A
LARGE OR SIGNIFICANT CONTRIBUTION FROM EITHER. WILL CONTINUE TO
ADVERTISE SCATTERED TO LIKELY POP VALUES TO HIGHLIGHT DECENT
PROBABILITIES OF MEASURABLE PRECIPITATION HOWEVER ACCOMPANIED BY
INTERMITTENT DRIZZLE.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...SHARP CLASSIC COLD AIR DAMMING EVENT WILL COME
TO AN END EARLY IN THE PERIOD WITH THE FORECAST DILEMMA BEING
FORECAST HIGHS FOR MONDAY. THE MET CONTINUES TO ADVERTISE THE
COOLER NUMBERS AND WITH LINGERING LOW LEVEL MOISTURE AND NEARING
THE WINTER SOLSTICE...THESE SEEM MORE REASONABLE ALTHOUGH WITH ANY
APPRECIABLE CLOUD OR EARLY BREAKS...VERY WARM TEMPERATURES IN THE
850-900MB LAYER COULD MIX DOWN.
THE FORECAST SOLUTIONS REGARDING THE FRONT TUESDAY CONTINUE TO WAVER
AND SLOW THE PROGRESSION OF THE FRONT. IN FACT...THE GFS SHOWS A
SECONDARY AREA OF QPF DEVELOPING WITH THE SOUTHWEST FLOW WEDNESDAY
THUS SLOWING THE FRONT FOR TUESDAY. THIS IS THE FIRST CYCLE THIS HAS
APPEARED SO I DID MAINTAIN THE LIKELY POPS FOR TUESDAY AND INCREASED
THE LONGEVITY OF THE MOISTURE FOR TUESDAY EVENING. NO CHANGES TO
TEMPERATURE FORECAST FOR TUESDAY.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...CONFIDENCE HAS WALKED BACK SLIGHTLY WITH REGARDS
TO THE EVENTS FOR THE EXTENDED FORECAST. THE NEW AND WETTER
SOLUTION AS ADVERTISED BY THE GFS OPERATIONAL PUTS WEDNESDAY IN
QUESTION ALTHOUGH I DID NOT CHANGE THE DRY FORECAST AT LEAST FOR
NOW TO SEE IF MORE SOLUTIONS COME IN SIMILAR. THE GFS ALSO
CONTINUES TO SHOW A FAIRLY STRONG SOUTHERN STREAM SYSTEM FOR THE
END OF THE WEEK INSTEAD OF THE WEAKLY FORCED COASTAL TROUGH. I
HAVE ALONG WITH ADJACENT OFFICES INCREASED POPS AND CLOUD COVER
FOR THE END OF THE PERIOD. NO CHANGES TO THE TEMPERATURE FORECAST
ALTHOUGH ONCE AGAIN THE READINGS MAY SEE SOME CHANGES DEPENDING ON
THE MASS FIELDS.
&&
.AVIATION /18Z SUNDAY THROUGH THURSDAY/...
AS OF 18Z...WEDGE WILL LIKELY REMAIN IN PLACE THROUGH MUCH OF THE
FORECAST PERIOD. HIGH CONFIDENCE FOR IFR CONDITIONS THIS
AFTERNOON...POSSIBLY BECOMING VLIFR TONIGHT. THE WARM AIR WILL START
TO OVERRIDE THE WEDGE LATE TONIGHT. THE RISING DEWPOINTS COUPLED WITH
DIURNAL AFFECTS SHOULD BE A GOOD RECIPE FOR DENSE FOG TONIGHT. WOULD
NOT BE SURPRISED TO SEE SOME M1/4SM ESPECIALLY OVER THE SOUTHERN
TERMINALS. MONDAY...DENSE FOG WILL LINGER THROUGH MID MORNING AT THE
COASTAL TERMINALS...LIFTING AS WINDS SHIFT TO THE SOUTHWEST AS THE
WEDGE ERODES. INLAND TERMINALS MAY SEE LIFR/IFR CONDITIONS THROUGH
THE END OF THE FORECAST PERIOD AS THE WEDGE IN TYPICAL FASHION WILL
BE STUBBORN TO RETREAT.
EXTENDED OUTLOOK...UNSETTLED WEATHER THROUGH TUESDAY WITH
LIFR/IFR/MVFR CONDITIONS DUE TO A NEARLY STATIONARY. SHOWERS LIKELY
TUESDAY FOLLOWED BY ANOTHER COLD FRONTAL PASSAGE. MODERATE
CONFIDENCE FOR VFR CONDITIONS WEDNESDAY THROUGH FRIDAY...EXCEPT
POSSIBLY THE COAST WEDNESDAY NIGHT. SHOWERS POSSIBLE
SATURDAY.
&&
.MARINE...
NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
AS OF 1025 AM SUNDAY...THE SCA HAS BEEN EXTENDED TO MID-
AFTERNOON TODAY FOR ALL WATERS. THE NE WINDS CONTINUE TO HOWL AT
15 TO 25 KT WITH GUSTS APPROACHING 30 KT OFF CAPE FEAR EARLY THIS
MORNING. WITH A SLIGHTLY SLOWER BREAKDOWN IN THE WEDGE BEING
FORECAST DURING THIS PERIOD...HAVE SLOWED THE DIMINISHING TREND OF
THE NE WINDS ACROSS THE LOCAL WATERS TODAY THROUGH TONIGHT. THIS
IS DEPICTED WELL BY THE HOURLY HRRR MODEL RUNS ILLUSTRATING
PROGGED SFC WINDS.
THIS WILL ALSO PRODUCE A SLOWER SUBSIDING TREND TO THE SIGNIFICANT
SEAS FROM ROUGHLY 4 TO 7 FT EARLY THIS AM...TO 2 TO 5 FT BY SUNDAY
EVENING. THE MAKE-UP OF THE SIGNIFICANT SEAS WILL REMAIN FROM THE
LOCALLY PRODUCED WIND DRIVEN VARIETY...WITH AVERAGE PERIODS AROUND
5 SECONDS.
SEA FOG MAY BECOME AN ISSUE ONCE AGAIN DURING THE PRE-DAWN MONDAY
HRS BUT LIKELY HOLD OFF INTO THE NEXT PERIOD WHEN S-SW WINDS ACROSS
LOCAL SSTS IN THE 50S OCCUR.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...LIGHT AND ESSENTIALLY VARIABLE WINDS WILL
QUICKLY FIND DEFINITION AS A SOUTHWEST FLOW OF 15-20 KNOTS DEVELOPS
MIDDAY MONDAY. THIS FLOW WILL CONTINUE THROUGH MOST OF THE DAY
TUESDAY BEFORE A LONG ADVERTISED FRONT MOVES ACROSS THE WATERS. BY
0600 UTC WEDNESDAY WINDS WILL BE NORTH ACROSS ALL WATERS WITH THE
SAME 15-20 KNOTS. THE CHANGE IN FETCH AND THE FACT WINDS SEEM TO
REMAIN CAPPED AT 20 KNOTS SHOULD KEEP SEAS BELOW FLAG CRITERIA IN A
2-4 FOOT RANGE.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...A NORTH TO NORTHEASTERLY FLOW WILL GREET
MARINERS INITIALLY WITH A FEW HOURS OF 15-20 KNOTS DIMINISHING
SLIGHTLY TO 10-15 KNOTS BY WEDNESDAY EVENING. SLOW MOVING HIGH
PRESSURE AND LOW PRESSURE WELL OFFSHORE WILL KEEP THIS FLOW IN
PLACE THROUGH THURSDAY. SEAS SHOULD REMAIN IN A 2-4 FOOT RANGE.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR AMZ250-
252-254-256.
&&
$$
NEAR TERM...DOUG/MJC
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DL/8
AREA FORECAST DISCUSSION
NWS WILMINGTON OH
1256 PM EST SUN DEC 8 2013
.SYNOPSIS...
LOW PRESSURE TRAVELING UP THE APPALACHIANS WILL BRING A MIXTURE OF
WINTRY PRECIPITATION TODAY INTO TONIGHT. HIGH PRESSURE WILL TRY TO
BUILD IN ON MONDAY...BUT ANOTHER WEAK SYSTEM WILL AFFECT THE
REGION ON TUESDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
DECENT ISENTROPIC LIFT COMBINING WITH UPR LEVEL DIVERGENCE FROM
THE RR QUAD ENTRANCE REGION OF UPR LEVEL JET WILL PRODUCE
WIDESPREAD PCPN ACRS THE REGION THIS MORNING INTO THE FIRST PART OF
THIS AFTERNOON. WAA WILL GRADUALLY WARM ATMOSPHERIC COLUMN ALOFT FROM
SE TO NW THROUGH THE DAY. AS THIS OCCURS...SNOW WILL TRANSITION TO
A MIXTURE OF SLEET AND FREEZING RAIN. IT SHOULD WARM UP ENOUGH IN
THE FAR SE LATE THIS AFTERNOON FOR LIQUID PCPN. UPDATE THIS
MORNING WAS TO BUMP UP SNOWFALL AMOUNTS A BIT IN THE SE CWFA AS
SOME BURSTS OF MODERATE SNOW HAS ALREADY RESULTED IN ACCUMS AROUND
AN INCH. SO...2 TO 3 LOOKS GOOD HERE WITH 1 TO 2 FARTHER NORTH IN
DAYTON AND COLUMBUS METROS AND LESS THAN AN INCH NORTHWEST. LATEST
MODEL INDICATE THAT WE COULD END UP WITH LIGHTER PCPN THIS
EVENING/OVERNIGHT OVER MUCH OF THE REGION DUE TO DEEP MOISTURE
EXITING AND FORCING REMAINING FOCUSED NEAR THE SE WITH A LOW LEVEL
JET. WITH WARM TEMPS ALOFT AND SFC TEMPS NEAR OR SLIGHTLY BELOW
FREEZING WILL RESULT IN EITHER LIGHT FREEZING RAIN OR FREEZING
DRIZZLE. HEADLINES WILL HAVE TO BE ADJUSTED AT SOME POINT. TOSSED
AROUND ADDING OUR NW CWFA IN AN ADVISORY...BUT WILL WAIT FOR SOME
NEWER MODEL RUNS TO SEE IF PCPN WILL BE ENOUGH TO DO SO. TEMPS
STARTING OUT COLD WITH ANY LIGHT LIQUID PCPN WITH SFC TEMPS BELOW
FREEZING COULD CAUSE SOME ISSUES ON UNTREATED SIDEWALKS AND ROADS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THE DEEP MOISTURE BEGINS TO BE SHUNTED E AT THE BEGINNING OF THE
PERIOD...LEAVING THE W WITH VERY SHALLOW MOISTURE AND WEAKENING
LIFT. THIS IS A SETUP FOR MORE OF A FZDZ/FZRA SCENARIO AS
COMPARED TO SN/PL. THEREFORE BEGAN TO LOWER THE POPS IN THE W AND
INTRODUCED MORE OF THE FZDZ/FZRA. EXPECT MUCH OF THE AREA TO MAKE
THE CHANGE OVER AS TONIGHT PROGRESSES. THE EXCEPTION WILL BE THE
SE/E WHERE TEMPERATURES MIGHT STAY UP ALL NIGHT THEREFORE STAYING
ALL RAIN. THE ADVISORY IN THOSE LOCATIONS MIGHT BE TOO LONG...BUT
WILL NOT CHANGE THE TIMING RIGHT NOW. INSTEAD WILL LET LATER
SHIFTS CANCEL IT IF IT IS NOT NEEDED. LOWS TONIGHT SHOULD STAY UP
IN THE LOWER TO MID 30S IN THE SE...BUT WILL FALL INTO THE UPPER
20S BACK TO THE W AS THE COOLER AIR WORKS IN ON THE BACKSIDE OF
THE SYSTEM
AS THE SYSTEM SLIDES E EARLY MONDAY...THE REGION WILL BE STUCK
UNDER A SUBSIDENCE INVERSION...WHICH SHOULD KEEP LOW CLOUDS IN
THROUGHOUT THE DAY. RIGHT NOW ENDED THE DZ/FZDZ MONDAY MORNING...BUT
WITH THE LOW CLOUDS THE LIGHT PCPN COULD LINGER.
MONDAY NIGHT INTO TUESDAY SEES A SPLIT LEVEL FLOW DEVELOP WITH
A NRN STREAM VORT PIVOTING INTO THRU THE OHIO VALLEY LATE MONDAY
NIGHT INTO TUESDAY. MODELS PRODUCE AN RIBBON OF SNOW ALONG THE
LEADING EDGE OF THE ARCTIC AIR...WITH THE NAM THE QUICKEST AS IT
PUSHES THE SNOW IN MONDAY NIGHT. THE GFS AND ECMWF WAIT UNTIL
TUESDAY TO BRING THIS FEATURE IN. WILL LEAN TOWARD THE GFS/ECMWF
SOLUTION AND WILL KEEP A MENTION OF SNOW ACRS SE HALF OF FA
TUESDAY.
HIGHS MONDAY AND TUESDAY WILL REMAIN MUCH BELOW NORMAL. ON MONDAY
THEY WILL BE IN THE UPPER 20S IN THE NW TO THE MID 30S IN THE SE.
THEN ON TUESDAY WITH THE WEATHER SYSTEM WORKING THROUGH HIGHS WILL
ONLY REACH THE LOWE 20S IN THE N AND THE LOWER 30S IN THE S.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGH PRESSURE TO NOSE INTO THE OHIO VALLEY WEDNESDAY WITH WEAK
SYSTEM DROPPING THRU THE GREAT LAKES. THE FAVORABLE MSTR/LIFT TO
STAY TO OUR NORTH...SO HAVE MAINTAINED A DRY FCST WED. COLD
TEMPERATURES TO PERSIST WITH LOWS AROUND 10 DEGREES WEST TO 15
DEGREES SE AND HIGHS LOWER/MIDDLE 20S NW TO THE LOWER 30S SE.
SFC HIGH PRESSURE TO BUILD ACRS THE REGION THURSDAY/FRIDAY TIME
FRAME. COLD TEMPERATURES TO CONTINUE THURSDAY WITH MORNING LOWS
FROM SINGLE DIGITS OVER THE WEST WHERE SNOW COVER EXISTS TO NEAR 15
SE. HIGHS TO RANGE FROM THE LOWER 20S NW TO NEAR 30 SE.
SOME MODERATION TO TEMPERATURES EXPECTED FRIDAY ON BACK SIDE OF SFC
HIGH PRESSURE WITH HIGHS FROM LOWER 30S NW TO THE UPPER 30S SE.
MID LEVEL FLOW BACKS WITH SYSTEM EXPECTED TO DEVELOP ALONG THE
EASTERN SEABOARD LATE FRIDAY INTO SATURDAY. ILN FA IS ON THE FAR NW
FRINGE OF THIS SYSTEM AND HAVE LIMITED ANY MENTION OF PRECIP TO A
SLIGHT CHC OF A SNOW SHOWER IN THE FAR SE LATE FRIDAY NIGHT INTO
SATURDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
STRONGEST WAA ASSOCIATED WITH UPPER LEVEL JET ENERGY WAS PIVOTING
NE OUT OF THE TAF REGION THIS AFTERNOON. A MIXTURE OF LIGHT
SNOW...SLEET AND FREEZING RAIN WILL TRANSITION OVER TO SOME PATCHY
LIGHT FREEZING RAIN OR LIGHT FREEZING DRIZZLE AS DEEP MOISTURE
GETS REPLACED WITH LOW LEVEL MOISTURE...WICH WILL LACK ICE
NUCLEATION FOR SNOW DEVELOPMENT.
FOR TONIGHT...A FRONTAL BOUNDARY WILL APPROACH THE REGION FROM THE
WEST AND WILL PUSH ACROSS THE TAF SITES LATE TONIGHT INTO MONDAY.
CONTINUED MOIST LOW LEVEL WAA AHEAD OF THE FRONT WILL RESULT IN
LOW CEILINGS AND VISIBILITIES...ALONG WITH SOME LIGHT FREEZING
RAIN/LIGHT FREEZING DRIZZLE OR IN THE LIQUID FORM AT SOME POINT
(KCMH/KLCK) BEFORE THE FRONT PUSHES BY. KEPT VISIBILITIES AS LOW
AS 1SM BUT WOULD NOT BE SURPRISED IF SOME POCKETS OF 1/2SM OR LESS
DEVELOP. ONCE THE FRONT MOVES THROUGH...DRIER AIR IN THE LOWER
LEVELS WILL RESULT IN A SLOW IMPROVEMENT IN VISIBILITIES AND
CEILINGS ON MONDAY...WITH MVFR CEILINGS AT LEAST CONTINUING INTO
THE AFTERNOON HOURS.
OUTLOOK...MVFR CEILINGS TO LINGER INTO MONDAY EVENING.
&&
.ILN WATCHES/WARNINGS/ADVISORIES...
OH...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR OHZ045-046-
051>056-060>065-070>074-077>082-088.
KY...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR KYZ089>100.
IN...WINTER WEATHER ADVISORY UNTIL 4 AM EST MONDAY FOR INZ050-058-
059-066-073>075-080.
&&
$$
SYNOPSIS...CONIGLIO/SITES
NEAR TERM...HICKMAN/SITES
SHORT TERM...SITES
LONG TERM...AR
AVIATION...HICKMAN
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1200 PM CST SUN DEC 8 2013
.DISCUSSION...
SEE AVIATION FOR 18Z TAF ISSUANCE.
&&
.AVIATION...
MOSTLY MVFR CIGS TOWARDS THE SOUTH WITH IFR CONDITIONS IN OUR
NORTHWESTERN PARTS OF THE CWA. NAM AND RAP ADVERTISING CLEARING
FOR KCLL...KUTS...AND POSSIBLY KCXO TONIGHT WHILE GFS AND ECMWF
HOLD UP THE CLEARING LINE. LOOKS LIKELY THAT SOME DRY AIR WILL
WORK IN FROM THE WEST BUT SHOULD ONLY PUNCH FAR ENOUGH SOUTH TO
CLEAR OUT MOST CLOUDS AT KCLL. SINCE NAM IS CLEARING OUT THE
CLOUDS IT ALSO SUPPORTS THE FORMATION OF FOG TO THE NORTHERN TAF
SITES. THIS IS SUPPORTED BY THE NAM DEWPOINT DEPRESSION FIELD.
LIGHT WINDS FROM THE SURFACE HIGH PRESSURE WILL ALSO HELP PROMOTE
FOG IN THE NORTHERN TAF SITES. STRONGER WINDS FURTHER SOUTHWARDS
IN COMBINATION WITH CLOUD COVER SHOULD KEEP IT MOSTLY A STRATUS
EVENT. 23
&&
.PREV DISCUSSION... /ISSUED 1028 AM CST SUN DEC 8 2013/
DISCUSSION...
TEMPERATURES HAVE FINALLY CREPT ABOVE FREEZING NOW ALL ZONES WITH
THE FREEZING LINE NOW JUST NORTHWEST OF OUR FORECAST AREA. SOME
SPOTS FROM CENTERVILLE OUT TOWARD METROPLEX STILL SEEING FREEZING
FOG BUT NOT EXPECTING ANY MORE ICY CONDITIONS IN THOSE NORTHWEST
COUNTIES WHICH HAD THE ISSUES LAST NIGHT AND EARLY THIS MORNING.
THEREFORE FREEZING FOG ADVISORY WILL BE ALLOWED TO EXPIRE.
GOING FORWARD...TRICKY TEMP FORECAST TODAY AS VISIBLE SATELLITE
SHOWING A FEW THIN SPOTS. AM FORECASTING HIGH TEMPERATURES A FEW
DEGREES BELOW MOST GUIDANCE BASED ON THE IDEA WILL KEEP CLOUD
COVER THROUGH THE AFTERNOON...WITH JUST BRIEF PERIODS OF
BRIGHTENING FROM SOME FILTERED SUN. AMOUNT OF SUN WILL DETERMINE
HIGH TEMPS...SO IF MORE THAN EXPECTED COULD EXCEED FORECAST
TEMPS...BUT DONT THINK THAT WILL HAPPEN. WITH SIMILAR VERTICAL
MOISTURE PROFILE...COULD STILL SEE SOME SPOTTY DRIZZLE OR
SPRINKLES TODAY AS WEAK DISTRUBANCES RIPPLE ALONG IN FAST WSW
FLOW ALOFT...BUT CHANCE OF MEASURABLE RAIN ONLY 20 PERCENT OR SO.
PREV DISCUSSION... /ISSUED 438 AM CST SUN DEC 8 2013/
DISCUSSION...
WENT AHEAD AND REPLACED WINTER WX ADVISORY WITH A FREEZING FOG
ADVISORY AND EXTENDED IT UNTIL 10 AM. FIRST ONE I`VE ISSUED IN 19
YEARS HERE...BUT SEEMS TO FIT/DESCRIBE ONGOING CONDITIONS BEST.
MODELS HAVE BEEN OVERDOING QPF AMOUNTS/COVERAGE AND FEEL THEY
PROBABLY WILL AGAIN TODAY ESP AS RRQ OF JET SHOULD LIFT OUTS OF
THE REGION. MAY STILL SEE A PATCHY AREA OF SPRINKLES/DRIZZLE
ACROSS SE PARTS THIS AFTN BUT WENT AHEAD AND LOWERED POPS TO ~20%.
REINFORCING FRONT STILL PENCILED IN TO MOVE THRU THE REGION ON
MONDAY. ANOTHER ROUND OF ISENTROPIC LIFT FROM LATE AFTN MON-LATE
TUE MORNING MAY BRING SOME MORE POCKETS OF DZ/-RA. WILL AGAIN
NEED TO KEEP AN EYE ON SFC TEMP PROFILE ACROSS OUR EXTREME NRN
COUNTIES DURING THIS TIME FRAME BUT FREEZING LINE DOESN`T LOOK TO
MAKE IT NEARLY AS FAR SOUTH AS THE PAST FEW.
P/MCLDY...COOL...MDRY DAYS SHOULD THEN PERSIST WED-THURS. COMBINATION
OF COASTAL TROF AND SHORTWAVES EMBEDDED IN THE SW FLOW ALOFT
SHOULD BRING INCREASED RAIN CHANCES THURS NIGHT AND INTO THE
WEEKEND. 47
MARINE...
LIGHT TO MODERATE OFFSHORE WINDS TO PREVAIL TODAY WITH HIGH PRESSURE
SETTLING OVER THE STATE. MODELS STILL GOING WITH THE PASSAGE OF A RE-
INFORCING COLD FRONT LATE TOMORROW. WINDS SHOULD PICK BACK UP TO SCA
AND/OR SCEC CRITERIA STARTING BY LATE MON NIGHT/TUES. THESE ELEVATED
WINDS/SEAS FCST TO PERSIST THROUGH WEDS (OR SO). THE STRONG SFC HIGH
IN THE WAKE OF THIS COLD AIRMASS IS NOT EXPECTED TO MOVE EAST OF THE
REGION UNTIL THE LATTER PART OF THE WEEK. AS SUCH WE MAY NOT SEE THE
RETURN OF ONSHORE WINDS UNTIL SAT. 41
AVIATION...
CIGS/VIS FALLING THIS MORNING WITH THE END OF THIS PCPN. WET GROUNDS
AND NEARLY CALM WINDS TO HELP IN THE FORMATION OF LOW CLOUDS/FZFG ON
THROUGH MID/LATE MORNING. HOWEVER STILL THINKING THAT MVFR CIGS WILL
PREVAIL BY THIS AFTN. CIGS/VIS COULD FALL AGAIN TONIGHT ALONG WITH A
RETURN OF LIGHT PCPN GIVEN THE PERSISTENT SWLY UPPER FLOW (AND POSSI-
BILITY OF ADDITIONAL EMBEDDED SHORTWAVES MOVING ACROSS). REINFORCING
SHOT OF COLD AIR EXPECTED MON NIGHT WITH WINDS INCREASING ONCE AGAIN
INTO TUES. 41
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 42 36 47 34 42 / 10 10 30 30 20
HOUSTON (IAH) 44 42 53 40 44 / 10 20 30 30 20
GALVESTON (GLS) 49 47 55 46 50 / 20 20 30 30 30
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
DISCUSSION...99
AVIATION/MARINE...23
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1254 PM EST SUN DEC 8 2013
.SYNOPSIS...
ARCTIC HIGH PRESSURE TO OUR NORTH WILL PROVIDE A CONTINUOUS
SOURCE OF COLD AIR TODAY. A TROUGH OF LOW PRESSURE DEVELOPING
OVER THE TENNESSEE RIVER VALLEY WILL PROVIDE A CONTINUOUS
SOURCE OF MOISTURE. THE COLD AIR WILL INTERACT WITH MOISTURE
FOR A BLEND OF WINTRY PRECIPITATION ACROSS THE REGION TODAY
AND TONIGHT. FREEZING RAIN WILL BE THE DOMINANT PRECIPITATION
TYPE.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS 1232 PM EST SUNDAY...
ADDED SOME FREEZING DRIZZLE AND FOG TO ISC GRIDS FOR THIS
AFTERNOON INTO TONIGHT. TEMPERATURES CONTINUE TO DROP AS
A WEDGE OF COLD AIR PUSHES DOWN THE APPALACHIANS. WINTER MIX OF
SNOW...SLEET AND FREEZING DRIZZLE AND FREEZING RAIN WILL
TRANSITION TO FREEZING RAIN/RAIN FOR MOST OF THE FORECAST
TONIGHT. LATEST RADAR TRENDS LINE UP NICELY WITH HRRR SOLUTION
FOR THIS AFTERNOON. ADJUSTED TEMPERATURES...WEATHER...POPS AND
AMOUNTS FOR THE NEXT COUPLE OF HOURS.
AS OF 944 AM EST SUNDAY...
WINTER STORM WARNINGS REMAIN IN EFFECT INTO MONDAY MORNING FOR
MOST OF CWA WITH A COMPLEX WINTER STORM MARCHING ACROSS OUR REGION
TODAY WITH A MIXTURE OF SNOW...SLEET...FREEZING RAIN AND RAIN.
TROUGH OF LOW PRESSURE OVER THE TENNESSEE RIVER VALLEY WILL
STRENGTHEN THIS AFTERNOON...PROVIDING A CONTINUOUS SOURCE OF
MOISTURE. HIGH PRESSURE LOCATED ACROSS PENNSYLVANIA IS BUILDING
INTO THE AREA FROM THE NORTH...PROVIDING A SOURCE OF COLD AIR. THE
WEDGE OF COLD AIR ON THE EAST SIDE OF THE MOUNTAINS WILL LIKELY
REMAIN IN PLACE THROUGH TONIGHT. SNOW AND SLEET REPORTED ACROSS
THE NORTH GENERALLY SOUTHEAST WEST VIRGINIA AND ALLEGHANY
HIGHLANDS. POCKETS OF SLEET AND FREEZING RAIN FALLING ACROSS
LARGE PORTION OF CWA THIS MORNING. REPORTS OF UP TO A TENTH OF AN
INCH OF ICE THIS MORNING. RAIN AND EVEN ELEVATED CONVECTION
REPORTED THIS MORNING ACROSS THE SOUTH. STILL LOOKS LIKE MOST OF
THE REGION WILL TRANSITION TO FREEZING RAIN THIS AFTERNOON INTO
TONIGHT. HIGHEST ICE AMOUNTS EXPECTED ALONG THE SOUTHERN BLUE
RIDGE. UPDATED ISC GRIDS TO MATCH UP WITH CURRENT WEATHER...TEMPERATURES
AND RADAR IMAGES. MORE ADJUSTMENTS LATER THIS MORNING....
WE WILL BE LAUNCHING A 18Z SOUNDING.
AS OF 500 AM EST SUNDAY...
ALL INGREDIENTS ARE IN PLACE FOR WINTRY PRECIPITATION TODAY.
SURFACE HIGH PRESSURE IS STILL BUILDING INTO THE AREA FROM THE
NORTHEAST. THIS WILL PROVIDE A CONTINUOUS SOURCE OF COLD AIR
TODAY...TEMPERATURES CONTINUING TO FALL THROUGH THE MORNING HOURS.
MOST LOCATIONS SHOULD WETBULB AT OR BELOW FREEZING THIS MORNING.
SOME AREAS ARE ALREADY WELL BELOW FREEZING...NOTING THE 21 DEG F
TEMP AT HSP AIRPORT AS OF 5AM.
TROUGH OF LOW PRESSURE OVER THE TENNESSEE RIVER VALLEY WILL
STRENGTHEN TODAY...PROVIDING A CONTINUOUS SOURCE OF MOISTURE.
ALL MODELS INDICATE STRONG ISENTROPIC LIFT ACROSS THE AREA WITH
INCREASING MID LEVEL FRONTOGENESIS. THIS SHOULD YIELD WIDESPREAD
DEVELOPMENT OF PRECIPITATION...QPF OF A QUARTER TO THREE QUARTERS
OF AN INCH...FROM 12Z/7AM THIS MORNING THROUGH 12Z/7AM MONDAY
MORNING. THIS WILL TRANSLATE INTO AN ACCUMULATION OF SIGNIFICANT
WINTRY PRECIPITATION...THE DOMINANT P-TYPE...FREEZING RAIN.
WARM INTRUSION ALOFT CAPS THE COLD BOUNDARY LAYER. VERY WARM
AIR...4-8 DEG C...IS MOVING NORTHEAST THROUGH THE TENNESSEE VALLEY
AND WILL FLOW UP AND OVERTOP THE COLD AIR WEDGE HERE ON THE EAST
SIDE OF THE APPALACHIAN MOUNTAINS. THIS SHOULD ENSURE THAT
MOST... IF NOT ALL...HYDROMETEORS MELT ON THERE WAY TO THE
SURFACE. THE ONLY AREA WHERE THE SOUNDING PROFILE MAY ENTERTAIN
ISOTHERMAL CHARACTERISTICS...THE WARM NOSE CLOSER TO 0 DEG C...IS
FROM THE HIGHLANDS OF VA/WV NORTHEASTWARD INTO THE SHENANDOAH
VALLEY. AS SUCH...THE PRECIPITATION MAY TAKE ON THE FORM OF SLEET
AND SNOW WHICH COULD ACCUMULATE AN INCH OR TWO THIS MORNING. BY
AFTERNOON...THE WARM INTRUSION SHOULD MAKE ITS WAY FAR ENOUGH
NORTH LATITUDE TO CHANGE THE PRECIP TO FREEZING RAIN THERE TOO.
THE WEDGE OF COLD AIR ON THE EAST SIDE OF THE MOUNTAINS WILL
LIKELY REMAIN IN PLACE THROUGH TONIGHT. GIVEN THE EXTENT OF
WARMING WHICH IS FORECAST TO TAKE PLACE ALOFT...SOME OF THE MODELS
INDICATING AS WARM AS +10 DEG C AT 85H...MODIFICATION OF THE COLD
BOUNDARY LAYER SEEMS INEVITABLE...AND SHOULD RESULTING IN
STEADILY RISING TEMPERATURES AT THE SURFACE. A GRADUAL CHANGE FROM
FREEZING RAIN TO JUST PLAIN OL RAIN IS ANTICIPATED...ESP WEST OF
THE APPALACHIAN DIVIDE. WITH THE INCREASED WARMING ALOFT...FOG
WILL LIKELY BECOME AN ISSUE AS THE WARMER AIR MIXES WITH THE COLD
MOIST BOUNDARY LAYER.
GREATEST ACCUMULATIONS OF ICE TODAY/TONIGHT ARE EXPECTED ALONG
THE SPINE OF THE BLUE RIDGE WHICH WILL RESIDE IN THE COLDER AIR
THE LONGEST...AND WHERE THE LOW LEVEL UPSLOPE EASTERLY WIND FLOW
WILL ENHANCE THE LOCAL QPF/ICING AMOUNTS. HIGHEST IMPACT FROM THIS
EVENT WILL BE ICING ON ELEVATED SURFACES. THE GROUND IS STILL
RELATIVELY WARM FROM THIS PAST WEEKS WARMTH...SO THEORETICALLY
THERE SHOULD BE LESS OF AN IMPACT TO ROAD SURFACES. THAT BEING
SAID...ITS STILL A GOOD DAY TO SIT THIS ONE OUT. THE ROADS CAN
FOOL YOU ONCE THE AIR TEMP REMAINS BELOW FREEZING LONG ENOUGH.
UNTREATED SURFACES MAY LOOK WET...BUT MAY ACTUALLY CONTAIN A THIN
COATING OF ICE HIDDEN BY WHAT APPEARS TO BE JUST WET PAVEMENT. IF
VENTURING OUT OF DOORS...PREP ACCORDINGLY. A COLD RAIN OR FREEZING
RAIN MAKES FOR IDEAL HYPOTHERMIC CONDITIONS. WALKING OUT TO CHECK
THE ICE ACCUMULATION ON MY VEHICLE WAS ENOUGH TO MAKE MY TEETH
CHATTER...AS THE OLD SAYING GOES...THE DAMPNESS IN THE AIR WILL
CUT RIGHT THROUGH YA...A COLD RAW RAIN.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 500 AM EST SUNDAY...
FOR THE MONDAY MORNING COMMUTE...MAY SEE A FEW POCKETS OF FREEZING
RAIN LEFT OVER ACROSS THE SHENANDOAH VALLEY...BUT OTHERWISE EXPECT
TEMPERATURES TO BE WARM ENOUGH ALL OTHER LOCATIONS FOR PRECIPITATION
TO FALL AS LIQUID. ANY ICING LEFTOVER FROM THE OVERNIGHT SHOULD MELT
QUICKLY DURING LATE MORNING AS TEMPERATURES CLIMB INTO THE MID 40S
NORTH OF INTERSTATE 81...AND INTO THE LOW 50S FURTHER SOUTH. DURING
MID AFTERNOON...EXPECT RAIN TO BECOME MORE SHOWERY IN NATURE AS A
COLD FRONT MAKES ITS WAY EAST ACROSS THE AREA. AS WINDS SHIFT
NORTHWESTERLY BEHIND THE FRONT...WILL SEE SHOWERS DIMINISH IN
COVERAGE FOR THE EVENING...ALTHOUGH THE BREAK WILL BE SHORT-LIVED.
PACIFIC HIGH PRESSURE WILL BUILD IN BEHIND THE COLD FRONT MONDAY
NIGHT...AND WILL BUILD SOUTHWARD AGAINST THE EASTERN FACE OF THE
APPALACHIANS BUY TUESDAY MORNING...RESULTING IN A COOL NORTHEASTERLY
WINDFLOW ACROSS THE AREA. MEANWHILE...OUR NEXT UPPER LEVEL TROUGH
WILL PASS ACROSS THE PLAINS...DRAWING ANOTHER WAVE OF WARM GULF
MOISTURE NORTHWARD ALONG THE APPALACHIAN CHAIN. RAIN ASSOCIATED WITH
THE TROUGH WILL COVER MUCH OF THE AREA DURING THE MORNING...BUT DO
NOT ANTICIPATE WIDESPREAD WINTRY PRECIPITATION ISSUES AS THE PACIFIC
HIGH PRESSURE SYSTEM HUGGING THE SURFACE WILL BE WARMER THAN THE
HIGH WHICH CONTRIBUTED TO FREEZING PRECIPITATION THIS PAST WEEKEND.
REGARDLESS...EXPECT TEMPERATURES TO REBOUND LITTLE...IF ANY...FROM
OVERNIGHT LOWS DUE TO THE RAIN...WITH AFTERNOON HIGHS RANGING FROM
AROUND FREEZING IN SOUTHEAST WEST VIRGINIA...TO THE LOW 40S ACROSS
NORTHERN NORTH CAROLINA.
THE UPPER LEVEL TROUGH WILL PASS EAST OF OUR AREA TUESDAY NIGHT...
TAKING REMAINING PRECIPITATION WITH IT FOR THE MOST PART...ALTHOUGH
A FEW UPSLOPE SNOW SHOWERS MAY LINGER ACROSS SOUTHEAST WEST VIRGINIA
INTO LATE EVENING. HIGH PRESSURE WILL BUILD IN FROM THE WEST...
BRINGING A RETURN OF SOME SUNSHINE FOR WEDNESDAY.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 310 PM EST SATURDAY...
SURFACE HIGH PRESSURE REMAINS OVER MUCH OF THE EASTERN UNITED STATES
THURSDAY AND FRIDAY WHICH WILL KEEP TEMPERATURES NEAR OR SLIGHTLY
BELOW NORMAL.
WEAK NORTHERN STREAM SHORTWAVE COMING THROUGH EARLY THURSDAY...BUT
MODELS KEEP FORECAST AREA DRY. NEXT ORGANIZED SYSTEM COMES OUT OF
SOUTHERN STREAM FRIDAY NIGHT THROUGH SATURDAY. THIS TIMING LEANS
TOWARD SLOWER ECMWF.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 1254 PM EST SUNDAY...
ICE AND LOW CEILINGS WILL HINDER AVIATION OPERATIONS THIS
AFTERNOON INTO MONDAY. VERY HIGH CONFIDENCE FOR SEVERE CLEAR ICING
AT ALL TAF SITES TODAY...WITH ONE QUARTER TO ONE HALF INCH ICE
ACCUMULATIONS POSSIBLE.
WINTRY MIXTURE OF SNOW...SLEET...FREEZING DRIZZLE AND FREEZING
RAIN WILL CONTINUE INTO THIS EVENING...THEN PRECIPIATION WILL
BECOME FREEZING RAIN AND RAIN TONIGHT INTO MONDAY MORNING.
ACROSS THE NORTH...WHERE COLDER AIR IN PLACE CLOSER TO
LWB...SNOW/ICE PELLETS WILL TRANSITION TO FREEZING RAIN. IFR
CONDITIONS ARE EXPECTED WITH THE WINTER PRECIPITATION AT THE TAF
SITES. EXPECT ALL AIRPORTS TO EXPERIENCE CEILINGS IN THE 300 TO
700 FOOT RANGE THIS AFTERNOON...WITH THESE LOW CEILINGS EXPECTED
TO LAST INTO MONDAY. VISIBILITIES WILL ALSO BE UP AND DOWN AS
HEAVIER PRECIPITATION MOVES ON AND OFF STATION.
WARMER AIR WILL BUILD INTO THE AREA TONIGHT...RAISING SURFACE
TEMPERATURES AND ENDING SEVERE CLEAR ICING FROM SOUTHWEST TO
NORTHEAST. SUBFREEZING AIR WILL LINGER LONGEST AT LYH...WHICH MAY
NOT SEE FREEZING PRECIPITATION END UNTIL 09/12Z TO 09/14Z.
MEDIUM TO HIGH CONFIDENCE ON CEILINGS AND VISIBILITIES. HIGH
CONFIDENCE IN WINDS DURING THE TAF PERIOD.
.AVIATION EXTENDED...
WEATHER WILL BE QUITE UNSETTLED THROUGH THE FIRST PART OF THE WEEK.
A COLD FRONT WILL MOVE THROUGH ON MONDAY...BRINGING IMPROVED
FLYING CONDITIONS AND A SHORT BREAK IN PRECIPITATION AS HIGH
PRESSURE BUILDS IN FROM THE WEST. RAIN...IN ADDITION TO MVFR/IFR...
WILL RETURN MONDAY NIGHT THROUGH TUESDAY MORNING AS AN UPPER
TROUGH MOVES ACROSS THE REGION. HIGH PRESSURE WILL BUILD IN FOR
WEDNESDAY AND THURSDAY WITH A RETURN TO VFR.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WINTER STORM WARNING UNTIL 9 AM EST MONDAY FOR VAZ011-013-014-
017>020-022>024-033>035-045>047.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR VAZ010-012-
015-016.
WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR VAZ032-043-044-
058-059.
FREEZING RAIN ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR VAZ007-
009.
NC...WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR NCZ001-002-
018.
WINTER STORM WARNING UNTIL 4 AM EST MONDAY FOR NCZ003>006-019-
020.
WV...WINTER STORM WARNING UNTIL 9 AM EST MONDAY FOR WVZ043>045.
WINTER STORM WARNING UNTIL MIDNIGHT EST TONIGHT FOR WVZ042.
&&
$$
SYNOPSIS...PM
NEAR TERM...KK/PM
SHORT TERM...NF
LONG TERM...AMS
AVIATION...KK/NF
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ONE SHORTWAVE
TROUGH MOVING INTO SOUTHWEST WISCONSIN THIS AFTERNOON...WHILE
ANOTHER WAVE NOW ENTERING THE CENTRAL GREAT PLAINS. AHEAD OF THE
FORMER SHORTWAVE...WEAK ISENTROPIC ASCENT IS PRODUCING A WIDESPREAD
SWATH OF LIGHT SNOW ACROSS THE STATE. THE BETTER SNOWS WITH THE
FIRST WAVE ARE STILL ACROSS IOWA AT THE MOMENT...WHERE VSBYS ARE
DOWN TO A HALF MILE AND WIDESPREAD 1-2 INCHES ARE BEING REPORTED SO
FAR. FURTHER CONCERNS RESIDE ALONG THE LAKE SHORE WHERE LAKE
ENHANCEMENT IS OCCURRING OVER CENTRAL AND SOUTHERN PARTS OF THE LAKE
MICHIGAN SHORELINE. EARLIER REPORTS SHOWED 1-1.5 INCH PER HOUR
SNOWFALL RATES IN THOSE LAKE ENHANCED BANDS. ONE OF THESE BANDS IS
APPROACHING MANITOWOC...BUT APPEARS TRANSIENT IN A LOW LEVEL
CONVERGENT ZONE. LOW LEVEL WINDS ARE JUST STARTING TO TURN TO THE
SOUTHEAST SO WILL NEED TO WATCH THESE TRENDS FOR THE REST OF THE
AFTERNOON. AS THE SHORTWAVES MOVE ACROSS THE ARE TONIGHT...SNOWFALL
AMOUNTS AND IMPACTS ARE THE MAIN FORECAST CONCERN.
TONIGHT...SHORTWAVE TROUGH OVER COLORADO WILL QUICKLY EJECT
NORTHEAST A DRIVE A STRENGTHENING...ALTHOUGH STILL RELATIVELY
WEAK...AREA OF LOW PRESSURE FROM THE CENTRAL GREAT PLAINS AND ACROSS
SOUTHEAST WISCONSIN TONIGHT. FORCING AHEAD OF THE SHORTWAVE IN THE
FORM OF -DIVQ...UPPER DIVERGENCE...AND ISENTROPIC ASCENT IS ONLY
MODEST...BUT BUFKIT SOUNDINGS FROM THE NAM/GFS/SREF ALL INDICATE A
150-200MB DEEP DENDRITIC GROWTH ZONE BETWEEN APPROX 850-650MB OVER
CENTRAL AND NORTHEAST WISCONSIN. THIS SUGGESTS THAT WHATEVER WEAK
TO MODERATE LIFT THAT OCCURS...SNOW FLAKE PRODUCTION WILL BE VERY
EFFICIENT AND SNOW TO LIQUID RATIOS WILL BE QUITE HIGH. GENERALLY
WENT WITH A 19-20:1 RATIO...ALTHOUGH A LITTLE LOWER NEAR THE LAKE
MICHIGAN SHORELINE WHERE ONSHORE FLOW WILL LEAD TO SLIGHTLY WARMER
LOW LEVEL THERMAL PROFILES. THE BULK OF THE SNOW LOOKS TO OCCUR IN
A COUPLE WAVES. THE FIRST WILL ARRIVE LATE THIS AFTERNOON INTO EARLY
THIS EVENING FROM THE FIRST AREA OF SNOW OVER IOWA AND SE
MINNESOTA...FOLLOW BY THE MAIN SHORTWAVE AND SURFACE LOW OVER
COLORADO. PLENTY OF 1-3" INCH REPORTS UPSTREAM OVER IOWA...AND FEW
4-6 INCH REPORTS OVER EASTERN NEBRASKA AS WELL. WILL INCREASE
AMOUNTS A LITTLE OVER N-C WISCONSIN TO AROUND 3 INCHES. THE PRIMARY
CONCERN THOUGH WILL BE ALONG THE LAKE SHORE WHERE WINDS WILL BE
TURNING TO THE EAST AND SOUTHEAST THIS EVENING. THE LAKE ENHANCEMENT
OVER SOUTHEAST WISCONSIN APPEARS TO BE FLUCTUATING...AS A CONVERGENT
BAND LIFTS NORTH. BUT EARLIER SNOWFALL RATES WHERE ENHANCEMENT TOOK
PLACE ARE ALARMING. LOOKS LIKE A GOOD 9-12 HOURS OF ENHANCEMENT
POSSIBLE OVER NORTHEAST WISCONSIN. WILL GO WITH WIDESPREAD 2-4
INCHES EXCEPT NEAR THE LAKESHORE WHERE 5-6 INCHES WILL BE POSSIBLE.
HEADLINES WILL REMAIN THE SAME...AND WILL PASS ALONG LAKE
ENHANCEMENT CONCERNS TO THE EVENING SHIFT.
MONDAY...THE SNOW WILL BE ENDING EARLY MONDAY MORNING OVER NORTHEAST
WISCONSIN AS THE SURFACE LOW PULLS AWAY. WEST WINDS WILL BE
STRENGTHENING IN THE WAKE OF THE LOW AND COLD ADVECTING AT THE SAME
TIME. TEMPS WILL REMAIN NEARLY STEADY OR FALL SLIGHTLY DURING THE
DAY...DESPITE CLEARING TAKING PLACE. WITH WINDS GUSTING TO 30
MPH...APPARENT TEMPS WILL BE FALLING TO NEAR 20 BELOW ZERO OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN DURING THE AFTERNOON. WILL
LIKELY NEED WIND CHILL HEADLINES...BUT WITH THE ONGOING SNOW
ADVISORY...WILL NOT ISSUE ANOTHER HEADLINE. MORNING TO MIDDAY HIGHS
IN THE MIDDLE SINGLE DIGITS NORTH TO THE UPPER TEENS NEAR THE LAKE
SHORE.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
VERY COLD AIR WILL REMAIN FIRMLY ENTRENCHED ACROSS THE AREA
MONDAY NIGHT. EXPECT WINDS CHILLS TO DROP TO AROUND 25 BELOW
ACROSS THE NORTH. HOWEVER...TEMPERATURES ARE EXPECTED TO
MODIFY SOME LATE MONDAY NIGHT DUE TO INCREASING CLOUDINESS
AND AHEAD OF APPROACHING SYSTEM. INCREASED CHANCES OF SNOW
ACROSS THE NORTHWEST HALF OF THE FORECAST AREA. INCREASED SNOW
CHANCES SIGNIFICANTLY ON TUESDAY MORNING AS SYSTEM MOVES ACROSS
THE AREA. ALSO...PRECIPITATION TOTALS WILL BE LIGHT...SNOW RATIOS
WOULD SUGGEST LESS THAN AN INCH OF NEW SNOW TUESDAY MORNING. THE
HIGHEST SNOWFALL TOTALS WILL BE ACROSS THE NORTH.
MOST OF THE MODELS NOW BRING CLIPPER SYSTEM SOUTH OF THE AREA
TUESDAY NIGHT. THE ONLY EXCEPTION WAS THE ECMWF...THUS WILL CONTINUE
CHANCES ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. THE GFS MODELS
HAS BEEN WAFFLING ON NORTHWARD EXTENT OF THE PRECIPITATION FIELD. VERY
COLD AIR IS EXPECTED WEDNESDAY MORNING. ANOTHER SYSTEM EXPECTED TO
PASS ACROSS THE NORTH THURSDAY/THURSDAY NIGHT. LOW CONFIDENCE ON WHEN
THIS SYSTEM WOULD BRING A SMALL CHANCE OF LIGHT SNOW DURING THIS PERIOD.
CURRENT FORECAST HAS LIGHT SNOW IN THE FORECAST THURSDAY NIGHT...BUT
LATER SHIFTS MAY NEED TO SPEED UP THE SNOW AND ADD A CHANCE TO THE
THURSDAY PERIOD. THE ARCTIC AIR WILL MODIFY FRIDAY INTO NEXT WEEKEND
WITH HIGHS IN THE UPPER TEENS TO MIDDLE 20S.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1131 AM CST SUN DEC 8 2013
LOW PRESSURE WILL MOVE NORTHEAST THIS AFTERNOON ACROSS
THE PLAINS AND THE CENTRAL GREAT LAKES TONIGHT. AHEAD OF THIS
LOW...LIGHT SNOW WILL CONTINUE THIS AFTERNOON WHICH WILL DROP VSBYS
TO IFR. THE SNOW WILL INCREASE IN INTENSITY THIS EVENING WHICH WILL
DROP VSBYS TO LIFR...MAINLY OVER CENTRAL AND NORTHEAST WISCONSIN. LOCALLY
VLIFR IN MODERATE TO HEAVY SNOW IS POSSIBLE ALONG THE LAKE MICHIGAN
SHORELINE DUE TO LAKE ENHANCEMENT. THE SNOW WILL GRADUALLY DIMINISH
OVERNIGHT TONIGHT...BUT WEST WINDS WILL DEVELOP BEHIND THE SYSTEM
AND BECOME GUSTY BY MORNING. THE GUSTY WEST WINDS WILL LIKELY
CREATE BLOWING AND DRIFTING OF THE NEW SNOW BY MIDDAY MONDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ005-010-011-
018>021-030-031-035>040-045-048>050-074.
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ012-013-022-
073.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......MPC