Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/07/14
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
859 PM MST MON JAN 6 2014
.UPDATE...MADE FURTHER BUT GENERALLY MINOR ADJUSTMENT TO OVERNIGHT
TEMPERATURES AND WINDS. MAIN CHANGE WAS TO SHOW A LARGER WARMUP
OVERNIGHT IN AND NEAR THE FOOTHILLS AND ACROSS THE NEARBY PLAINS
INCLUDING DENVER METRO. ALSO ADDED SOME PATCHY BLOWING SNOW WHERE
MOUNTAIN WAVE AND WIND GUSTS TO AROUND 40 MPH COULD PRODUCE
BLOWING SNOW IN OPEN AREAS FROM THE FOOTHILLS ONTO THE NEARBY
ADJACENT PLAINS INCLUDING HIGHWAY 93 BOULDER-GOLDEN AND I-25 NEAR
THE WYOMING BORDER.
&&
.PREV DISCUSSION... /ISSUED 603 PM MST MON JAN 6 2014/
UPDATE...UPDATED FOR LATEST TEMPERATURE TRENDS. READINGS SHOULD
REALLY BOTTOM OUT OVERNIGHT IN LOW LYING AREAS DUE TO LIGHT
WINDS/MAINLY CLEAR SKIES...AND FRESH SNOW COVER.
MEANWHILE..READINGS CLOSER TO THE FRONT RANGE WILL BOTTOM OUT IN
THE NEXT HOUR OR TWO...OR ALREADY HAVE BOTTOMED OUT WITH DRAINAGE
WINDS SETTING IN.
&&
.AVIATION...LIGHT DRAINAGE WINDS DEVELOPING AT KDEN AND SHOULD
REMAIN IN PLACE THROUGH TUESDAY MORNING. OTHERWISE NO CHANGES.
.PREV DISCUSSION... /ISSUED 344 PM MST MON JAN 6 2014/
SHORT TERM...UPPER JET HAS MOVED INTO THE CENTRAL PLAINS WITH
WEAKENING NORTHWEST FLOW ALOFT. WINDS HAVE DECREASED CONSIDERABLY
ACROSS THE MOUNTAINS...FOOTHILLS AND PARK COUNTY IN RESPONSE TO
WEAKENING GRADIENT...THOUGH STILL A BIT GUSTY. WESTERLY WINDS HAVE
SPREAD ONTO THE ADJACENT PLAINS OF NORTHERN JEFFERSON COUNTY...
ROUGHLY FROM GOLDEN TO THE BOULDER COUNTY LINE. THERE MAY STILL BE
SOME BLOWING SNOW IN OPEN AREAS. FLOW ALOFT BECOMES A BIT MORE
WESTERLY THIS EVENING AS WEAK UPPER TROUGH MOVES INTO THE NORTHERN
GREAT BASIN. MODELS SHOW A BIT OF A MOUNTAIN WAVE WITH CROSS
MOUNTAIN FLOW AROUND 30 KTS. WINDS TO REMAIN A BIT GUSTY ACROSS
THE MOUNTAINS AND FOOTHILLS WITH SOME GUSTS TO 45 MPH. LATEST HRRR
AND RAP ALSO SHOW WESTERLY WINDS PERSISTING ALONG THE BASE OF THE
FOOTHILLS THROUGH 06Z BEFORE DECREASING OVERNIGHT WITH SOME GUSTS
TO 30 MPH POSSIBLE. SOME POTENTIAL STILL EXISTS FOR BLOWING SNOW
IN OPEN AREAS...BUT LOOKS RATHER LOCALIZED SO WON`T INCLUDE IN
GRIDS FOR NOW. APPEARS BEST HANDLED WITH NOWCASTS. SOME INCREASE
IN MID LEVEL MOISTURE THROUGH THE EVENING AND INTO THE OVERNIGHT
HOURS. CHANCE FOR A WAVE CLOUD DEVELOPING IN AND NEAR THE
FOOTHILLS...AS SHOWN BY CIRA SYNTHETIC SATELLITE IMAGEY BECOMING
FAIRLY EXTENSIVE BETWEEN 09Z AND 15Z. OVERNIGHT LOWS TO MODERATE A
BIT...ESPECIALLY NEAR THE FOOTHILLS OF BOULDER AND JEFFERSON
COUNTY WHERE DOWNSLOPE WINDS WILL AID IN WARMING. LOW LYING AREAS
IN WELD COUNTY WILL STRUGGLE TO STAY ABOVE ZERO. ON TUESDAY...WEST
NORTHWEST FLOW ALOFT WILL PREVAIL. MODELS SHOW THE WEAK TROUGH
MOVING ACROSS WYOMING DURING THE AFTERNOON WITH SOME INCREASE IN
MID LEVEL QG ASCENT ACROSS THE MOUNTAINS LATE IN THE DAY. CROSS
SECTIONS INDICATE AN INCREASE IN IN MOISTURE ABOVE MOUNTAIN TOP.
SOME OROGRAPHICS IN PLACE ACROSS ZONE 31 TO KEEP A SLIGHT CHANCE
OF SNOW GOING. DID DELAY THE ONSET UNTIL 21Z WHEN OROGRAPHICS
BEGINS TO IMPROVE. OTHERWISE...A GRADUAL INCREASE IN CLOUDS. FLOW
ALOFT DECREASES SLIGHTLY THOUGH STILL A BIT OF A MOUNTAIN WAVE.
MAY STILL BE GUSTY OVER THE MOUNTAINS AND ALONG FOOTHILLS.
TEMPERATURES ACROSS PLAINS TO WARM INTO THE MIDDLE 40S MOST
AREAS...WITH UPPER 30S IN LOW LYING AREAS ACROSS WELD COUNTY.
LONG TERM...SWIFT WEST-NORTHWEST FLOW WILL SEND A SERIES OF WEAK TO
MODERATE PERTABATIONS ACROSS COLORADO DURING THE UPCOMING WEEK.
MODELS GENERALLY AGREE IN PASSING THE NEXT WAVE ACROSS COLORADO
TUESDAY NIGHT/WEDNESDAY MORNING. MOUNTAINS SHOULD SCOOP UP MOST
OF THE MOISTURE CARRIED ALONG BY THIS SYSTEM. SCATTERED TO LIKELY
POPS ARE IN ORDER FOR THE NORTHERN AND CENTRAL MTNS DURING THIS
PERIOD. HOWEVER THE RATHER SHALLOW DEPTH OF THE MOISTURE SHOULD
KEEP ACCUMULATIONS ON THE LOW SIDE. QG VERT VELOCITY FIELDS
INDICATE ONLY WEAK SFC-500 ASCENT WITH ITS PASSAGE TUE NIGHT. ITS
POSSIBLE THE NORTHEAST CORNER OF THE CWFA COULD SEE A FEW
FLURRIES. OTHERWISE IT SHOULD REMAIN DRY EAST OF THE MTNS.
MEANWHILE TEMPERATURES WILL CONTINUE TO MODERATE WITH A LOW-LEVEL
DOWNSLOPE FLOW IN PLACE EAST OF THE FRONT RANGE. WEDNESDAY THROUGH
THURSDAY...FLOW ALOFT TRANSITIONS TO MORE OF A ZONAL COMPONENT
AND WEAK RIPPLES EMBEDDED IN THIS FLOW AND OROGRAPHICS SHOULD
CONTINUE TO PRODUCE PERIODS OF LIGHT SNOW THROUGH THE PERIOD.
AGAIN...ANY SNOW ACCUMULATION SHOULD BE MINOR AND LARGELY CONFINED
TO WEST FACING SLOPES AND TIMBERLINE AREAS.
NEXT...GFS AND ECMWF CONTINUE TO SHOW A LARGE OPEN WAVE TROUGH
FORMING OVER THE GREAT BASIN WEDNESDAY NIGHT AND THURSDAY AND
TRANSLATING EASTWARD ACROSS THE ROCKY MTN REGION THURSDAY NIGHT
AND FRIDAY. ENERGY AND MOISTURE ASSOCIATED WITH THIS WAVE APPEARS
SPLIT WITH PART PASSING OVER WYOMING AND THE OTHER PART OVER
SOUTHERN COLORADO AND NEW MEXICO. HOWEVER THE SOUTHERN BRANCH OF
ENERGY AND MOISTURE IS PROGGED TO LIFT NORTHEAST ACROSS OUR PART
OF THE STATE THURSDAY NIGHT/EARLY FRIDAY MORNING. THIS MAY BE THE
NEXT BEST CHANCE FOR SNOW ACCUMULATION IN THE HIGH COUNTRY THIS
WEEK. WHILE THE PLAINS WILL PROBABLY ESCAPE WITH ONLY A FEW
FLURRIES OR LIGHT SNOW SHOWERS UP AGAINST THE FOOTHILLS AND PALMER
DIVIDE. TEMPERATURES BOTH DAYS ARE EXPECTED TO REMAIN AT OR
SLIGHTLY ABOVE AVERAGE EVEN WITH ALL OF THE CLOUD COVER. BY
SATURDAY...MEDIUM RANGE MODELS SHOW THE TROUGH QUICKLY MOVING OUT
WHICH SETS THE STAGE FOR A WARMING AND GUSTY CHINOOK WIND ALONG
THE FRONT RANGE. SHOULD SEE A NICE REBOUND IN TEMPERATURES OVER
AND EAST OF THE FRONT RANGE THAT DAY UNDER CLEARING SKIES. HIGH
COUNTRY ALSO LOOKS DRY WITH AMPLE SUNSHINE. THEN ON SATURDAY NIGHT
AND SUNDAY...THE NEXT IN THE SERIES OF SYSTEMS ORIGINATING OVER
THE PACIFIC NORTHWEST RACES ACROSS WYOMING AND NORTHERN COLORADO.
LOOKS LIKE ANOTHER SHOT OF SNOW AND GUSTY WINDS FOR THE HIGH
COUNTRY AND GUSTY WINDS AND A SLIGHT CHANCE OF RAIN/SNOW FOR LOWER
ELEVATIONS. MONDAY LOOKS DRIER AND WARMER WITH UPPER RIDGE
BUILDING OVER THE INTERMOUNTAIN WEST.
AVIATION...NORTHWEST WINDS CURRENTLY SPREADING ACROSS KBJC AND
KDEN WITH SPEEDS AROUND 8 KTS. LIGHT SOUTHEAST WINDS CONTINUING AT
KAPA. LATEST MODELS STILL INDICATING WINDS TO BECOME SOUTHEAST AT
KDEN AROUND 00Z. WILL CONTINUE THIS TREND FOR THE UPCOMING
ISSUANCE. WINDS TO BE MORE WESTERLY AT KBJC WITH SOME GUSTS TO 20
KTS AFTER 06Z. SOME INCREASE IN MID AND HIGH LEVEL CLOUD WITH
POTENTIAL FOR A WAVE CLOUD IN AND NEAR THE FOOTHILLS AFTER 10Z.
CEILINGS TO REMAIN ABOVE 12000 FEET. WINDS TO WEAKEN BY 15Z AND
BECOME SOUTHERLY. MAY BE MORE SOUTHEAST AT KDEN AND KAPA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....BAKER
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
603 PM MST MON JAN 6 2014
.UPDATE...UPDATED FOR LATEST TEMPERATURE TRENDS. READINGS SHOULD
REALLY BOTTOM OUT OVERNIGHT IN LOW LYING AREAS DUE TO LIGHT
WINDS/MAINLY CLEAR SKIES...AND FRESH SNOW COVER.
MEANWHILE..READINGS CLOSER TO THE FRONT RANGE WILL BOTTOM OUT IN
THE NEXT HOUR OR TWO...OR ALREADY HAVE BOTTOMED OUT WITH DRAINAGE
WINDS SETTING IN.
&&
.AVIATION...LIGHT DRAINAGE WINDS DEVELOPING AT KDEN AND SHOULD
REMAIN IN PLACE THROUGH TUESDAY MORNING. OTHERWISE NO CHANGES.
&&
.PREV DISCUSSION... /ISSUED 344 PM MST MON JAN 6 2014/
SHORT TERM...UPPER JET HAS MOVED INTO THE CENTRAL PLAINS WITH
WEAKENING NORTHWEST FLOW ALOFT. WINDS HAVE DECREASED CONSIDERABLY
ACROSS THE MOUNTAINS...FOOTHILLS AND PARK COUNTY IN RESPONSE TO
WEAKENING GRADIENT...THOUGH STILL A BIT GUSTY. WESTERLY WINDS HAVE
SPREAD ONTO THE ADJACENT PLAINS OF NORTHERN JEFFERSON COUNTY...
ROUGHLY FROM GOLDEN TO THE BOULDER COUNTY LINE. THERE MAY STILL BE
SOME BLOWING SNOW IN OPEN AREAS. FLOW ALOFT BECOMES A BIT MORE
WESTERLY THIS EVENING AS WEAK UPPER TROUGH MOVES INTO THE NORTHERN
GREAT BASIN. MODELS SHOW A BIT OF A MOUNTAIN WAVE WITH CROSS
MOUNTAIN FLOW AROUND 30 KTS. WINDS TO REMAIN A BIT GUSTY ACROSS
THE MOUNTAINS AND FOOTHILLS WITH SOME GUSTS TO 45 MPH. LATEST HRRR
AND RAP ALSO SHOW WESTERLY WINDS PERSISTING ALONG THE BASE OF THE
FOOTHILLS THROUGH 06Z BEFORE DECREASING OVERNIGHT WITH SOME GUSTS
TO 30 MPH POSSIBLE. SOME POTENTIAL STILL EXISTS FOR BLOWING SNOW
IN OPEN AREAS...BUT LOOKS RATHER LOCALIZED SO WON`T INCLUDE IN
GRIDS FOR NOW. APPEARS BEST HANDLED WITH NOWCASTS. SOME INCREASE
IN MID LEVEL MOISTURE THROUGH THE EVENING AND INTO THE OVERNIGHT
HOURS. CHANCE FOR A WAVE CLOUD DEVELOPING IN AND NEAR THE
FOOTHILLS...AS SHOWN BY CIRA SYNTHETIC SATELLITE IMAGEY BECOMING
FAIRLY EXTENSIVE BETWEEN 09Z AND 15Z. OVERNIGHT LOWS TO MODERATE A
BIT...ESPECIALLY NEAR THE FOOTHILLS OF BOULDER AND JEFFERSON
COUNTY WHERE DOWNSLOPE WINDS WILL AID IN WARMING. LOW LYING AREAS
IN WELD COUNTY WILL STRUGGLE TO STAY ABOVE ZERO. ON TUESDAY...WEST
NORTHWEST FLOW ALOFT WILL PREVAIL. MODELS SHOW THE WEAK TROUGH
MOVING ACROSS WYOMING DURING THE AFTERNOON WITH SOME INCREASE IN
MID LEVEL QG ASCENT ACROSS THE MOUNTAINS LATE IN THE DAY. CROSS
SECTIONS INDICATE AN INCREASE IN IN MOISTURE ABOVE MOUNTAIN TOP.
SOME OROGRAPHICS IN PLACE ACROSS ZONE 31 TO KEEP A SLIGHT CHANCE
OF SNOW GOING. DID DELAY THE ONSET UNTIL 21Z WHEN OROGRAPHICS
BEGINS TO IMPROVE. OTHERWISE...A GRADUAL INCREASE IN CLOUDS. FLOW
ALOFT DECREASES SLIGHTLY THOUGH STILL A BIT OF A MOUNTAIN WAVE.
MAY STILL BE GUSTY OVER THE MOUNTAINS AND ALONG FOOTHILLS.
TEMPERATURES ACROSS PLAINS TO WARM INTO THE MIDDLE 40S MOST
AREAS...WITH UPPER 30S IN LOW LYING AREAS ACROSS WELD COUNTY.
LONG TERM...SWIFT WEST-NORTHWEST FLOW WILL SEND A SERIES OF WEAK TO
MODERATE PERTABATIONS ACROSS COLORADO DURING THE UPCOMING WEEK.
MODELS GENERALLY AGREE IN PASSING THE NEXT WAVE ACROSS COLORADO
TUESDAY NIGHT/WEDNESDAY MORNING. MOUNTAINS SHOULD SCOOP UP MOST
OF THE MOISTURE CARRIED ALONG BY THIS SYSTEM. SCATTERED TO LIKELY
POPS ARE IN ORDER FOR THE NORTHERN AND CENTRAL MTNS DURING THIS
PERIOD. HOWEVER THE RATHER SHALLOW DEPTH OF THE MOISTURE SHOULD
KEEP ACCUMULATIONS ON THE LOW SIDE. QG VERT VELOCITY FIELDS
INDICATE ONLY WEAK SFC-500 ASCENT WITH ITS PASSAGE TUE NIGHT. ITS
POSSIBLE THE NORTHEAST CORNER OF THE CWFA COULD SEE A FEW
FLURRIES. OTHERWISE IT SHOULD REMAIN DRY EAST OF THE MTNS.
MEANWHILE TEMPERATURES WILL CONTINUE TO MODERATE WITH A LOW-LEVEL
DOWNSLOPE FLOW IN PLACE EAST OF THE FRONT RANGE. WEDNESDAY THROUGH
THURSDAY...FLOW ALOFT TRANSITIONS TO MORE OF A ZONAL COMPONENT
AND WEAK RIPPLES EMBEDDED IN THIS FLOW AND OROGRAPHICS SHOULD
CONTINUE TO PRODUCE PERIODS OF LIGHT SNOW THROUGH THE PERIOD.
AGAIN...ANY SNOW ACCUMULATION SHOULD BE MINOR AND LARGELY CONFINED
TO WEST FACING SLOPES AND TIMBERLINE AREAS.
NEXT...GFS AND ECMWF CONTINUE TO SHOW A LARGE OPEN WAVE TROUGH
FORMING OVER THE GREAT BASIN WEDNESDAY NIGHT AND THURSDAY AND
TRANSLATING EASTWARD ACROSS THE ROCKY MTN REGION THURSDAY NIGHT
AND FRIDAY. ENERGY AND MOISTURE ASSOCIATED WITH THIS WAVE APPEARS
SPLIT WITH PART PASSING OVER WYOMING AND THE OTHER PART OVER
SOUTHERN COLORADO AND NEW MEXICO. HOWEVER THE SOUTHERN BRANCH OF
ENERGY AND MOISTURE IS PROGGED TO LIFT NORTHEAST ACROSS OUR PART
OF THE STATE THURSDAY NIGHT/EARLY FRIDAY MORNING. THIS MAY BE THE
NEXT BEST CHANCE FOR SNOW ACCUMULATION IN THE HIGH COUNTRY THIS
WEEK. WHILE THE PLAINS WILL PROBABLY ESCAPE WITH ONLY A FEW
FLURRIES OR LIGHT SNOW SHOWERS UP AGAINST THE FOOTHILLS AND PALMER
DIVIDE. TEMPERATURES BOTH DAYS ARE EXPECTED TO REMAIN AT OR
SLIGHTLY ABOVE AVERAGE EVEN WITH ALL OF THE CLOUD COVER. BY
SATURDAY...MEDIUM RANGE MODELS SHOW THE TROUGH QUICKLY MOVING OUT
WHICH SETS THE STAGE FOR A WARMING AND GUSTY CHINOOK WIND ALONG
THE FRONT RANGE. SHOULD SEE A NICE REBOUND IN TEMPERATURES OVER
AND EAST OF THE FRONT RANGE THAT DAY UNDER CLEARING SKIES. HIGH
COUNTRY ALSO LOOKS DRY WITH AMPLE SUNSHINE. THEN ON SATURDAY NIGHT
AND SUNDAY...THE NEXT IN THE SERIES OF SYSTEMS ORIGINATING OVER
THE PACIFIC NORTHWEST RACES ACROSS WYOMING AND NORTHERN COLORADO.
LOOKS LIKE ANOTHER SHOT OF SNOW AND GUSTY WINDS FOR THE HIGH
COUNTRY AND GUSTY WINDS AND A SLIGHT CHANCE OF RAIN/SNOW FOR LOWER
ELEVATIONS. MONDAY LOOKS DRIER AND WARMER WITH UPPER RIDGE
BUILDING OVER THE INTERMOUNTAIN WEST.
AVIATION...NORTHWEST WINDS CURRENTLY SPREADING ACROSS KBJC AND
KDEN WITH SPEEDS AROUND 8 KTS. LIGHT SOUTHEAST WINDS CONTINUING AT
KAPA. LATEST MODELS STILL INDICATING WINDS TO BECOME SOUTHEAST AT
KDEN AROUND 00Z. WILL CONTINUE THIS TREND FOR THE UPCOMING
ISSUANCE. WINDS TO BE MORE WESTERLY AT KBJC WITH SOME GUSTS TO 20
KTS AFTER 06Z. SOME INCREASE IN MID AND HIGH LEVEL CLOUD WITH
POTENTIAL FOR A WAVE CLOUD IN AND NEAR THE FOOTHILLS AFTER 10Z.
CEILINGS TO REMAIN ABOVE 12000 FEET. WINDS TO WEAKEN BY 15Z AND
BECOME SOUTHERLY. MAY BE MORE SOUTHEAST AT KDEN AND KAPA.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BARJENBRUCH
LONG TERM....BAKER
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1244 PM EST SUN JAN 5 2014
.SYNOPSIS...
AN AREA OF LOW PRESSURE RIDES NORTHEAST ALONG A COLD FRONT
STRETCHING FROM THE CENTRAL GULF COAST INTO QUEBEC INTO MONDAY.
ITS ASSOCIATED WARM FRONT LIFTS THROUGH THE AREA
TONIGHT...FOLLOWED BY ITS TRAILING ARCTIC FRONT BY MONDAY
AFTERNOON. ARCTIC AIR THEN POURS INTO THE REGION INTO THE MIDDLE
OF THE WEEK. THE WEATHER WILL BE UNSETTLED FOR THE LATTER PART OF
THE WEEK AS A WEAK FRONTAL BOUNDARY STALLS NEAR THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LIGHT FREEZING RAIN AND LIGHT FREEZING DRIZZLE CONTINUES TO SPREAD
INLAND...WHERE TEMPS ARE IN THE TEENS TO MID 20S. LONG ISLAND IS
BEGINNING TO RISE ABOVE FREEZING...BUT THOSE TEMPS ARE TAKEN AT 6
FT...AND WITH SNOWPACK ON THE GROUND...THINK TEMPS AT THE GROUND
ARE STILL AT OR BELOW FREEZING. WILL TAKE SOME TIME FOR THE WARMER
AIR TO SPREAD NORTH...AS SE WINDS DO NOT LOOK TO INCREASE UNTIL
LATE AFTERNOON/EARLY EVENING. AS SUCH...MODIFIED THE FREEZING RAIN
ADVISORY TO EXTEND FOR NYC...NEARBY NJ...AND LONG ISLAND UNTIL 4
PM AND EVERYBODY ELSE UNTIL 7 PM. LATEST HRRR AND 12Z NAM
INDICATING A PERIOD OF DRYING BY FROM 21Z-00Z...SO IT IS LIKELY
THAT THE ADVISORY CAN BE CANCELLED PRIOR TO THAT.
TRAVEL IS TREACHEROUS...AND THERE HAVE BEEN NUMEROUS TRAFFIC
ACCIDENTS REPORTED ACROSS THE AREA DUE TO THE ICED UP ROADS.
ICE ACCUMULATIONS SHOULD AVERAGE A TRACE TO MAYBE A FEW
HUNDREDTHS OF AN INCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
ANY LINGERING FREEZING RAIN OVER ORANGE COUNTY SHOULD TURN TO ALL
RAIN BY EARLY EVENING.
ISENTROPIC LIFT STEADILY INCREASES IN DEPTH/SATURATION...COUPLED
WITH A 45-60 KT LOW LEVEL JST PASSING OVER THE REGION...WILL SEE
AN INCREASE IN THE COVERAGE AND INTENSITY OF THE RAIN WILL DO
LIKEWISE FROM TONIGHT INTO MONDAY MORNING. SEE HYDROLOGY SECTION
OF THE AFD FOR DETAILS AND IMPACT.
RAINFALL COMES TO AN END WITH THE PASSAGE OF THE ARCTIC FRONT
MAINLY DURING THE MORNING HOURS ON MONDAY. COULD SEE SOME SHOWERS
IMMEDIATELY IN ITS WAKE - EITHER SHRA/SHSN OR BOTH DEPENDING ON
EXACTLY HOW FAST THE TEMPERATURES FALL OF NEAR THE SURFACE. HAVE
THE POTENTIAL FOR A FLASH FREEZE IN THE AFTERNOON - ESPECIALLY IN
AREAS FROM NYC ON N/W WHERE TEMPERATURES FALL INTO THE
TEENS/AROUND 20 BY EVENING. LESS CERTAIN FARTHER E WHERE
TEMPERATURES ONLY FALL INTO THE 20S.
BITTERLY COLD AIR THEN MOVES IN MONDAY NIGHT-TUESDAY NIGHT...
LOWS MONDAY NIGHT FROM THE LOW SINGLE DIGITS FAR NW TO MID TEENS
FAR E...HIGHS TUESDAY FROM THE UPPER SINGLE DIGITS FAR NW TO
AROUND 20 FAR E...AND LOWS TUESDAY NIGHT MAINLY FROM 5 BELOW TO 5
ABOVE - A TAD HIGHER IN NYC/THE TWIN FORKS/AND AT THE IMMEDIATE
COAST.
WINDS TO POSSIBLY WIND ADVISORY LEVELS ACROSS NYC/LONG ISLAND AND
HIGHER ELEVATIONS ACROSS THE INTERIOR...AND JUST BELOW ADVISORY
LEVELS ELSEWHERE WILL PRODUCE POTENTIALLY DANGEROUS WIND CHILLS
MONDAY NIGHT-TUESDAY NIGHT. WIND CHILLS MONDAY NIGHT WILL FALL TO
-15 TO -20 ACROSS NW INTERIOR ZONES...-5 T0 -15 ACROSS MOST OF THE
REMAINDER OF THE AREA...EXCEPT AROUND 0 FAR EASTERN AREAS. WIND
CHILLS MODERATE SLIGHTLY DURING THE DAY ON TUESDAY TO FROM -15 TO
0 (HIGHEST FAR E). DIMINISHING WINDS TUESDAY NIGHT WILL LIMIT WIND
CHILLS TO GENERALLY -5 TO -15 (LOWEST FAR NW)...EXCEPT -5 TO 0 FAR
E ZONES.
WIND CHILL ADVISORIES WILL LIKELY BE NEEDED FOR WESTERN NE NJ
ZONES AND MOST OF THE LOWER HUDSON VALLEY FROM MONDAY NIGHT INTO
TUESDAY MORNING. STILL SOME UNCERTAINTY ON EXACTLY HOW THE WINDS
AND TEMPERATURES PLAY OUT - GUIDANCE TENDS TO BE TOO WARM IN
EXTREME EVENTS LIKE THIS - ESPECIALLY THIS FAR OUT - SO EVEN
THOUGH IT WAS UNDERCUT USING A BLEND OF MODEL 2-METER TEMPERATURES
NOT SURE IF HAVE GONE COLD ENOUGH. BECAUSE OF THIS - STILL WILL
HIGHLIGHT THE CHANCE OF WIND CHILLS AROUND -25 ACROSS INTERIOR
ZONES IN THE HWO MONDAY NIGHT/TUESDAY MORNING.
THE STRONG WNW WINDS AND COLD AIR IN THE LOW LEVELS FROM MONDAY
NIGHT INTO TUESDAY NIGHT WILL ALSO CREATE CONDITIONS RIPE FOR SOUND
EFFECT SNOW. AS TIME GOES ON CONFIDENCE INCREASES - SO HAVE
INCREASED POPS OVER THE TWIN FORKS TO CHANCE ON TUESDAY AFTERNOON
- AS SUGGESTED BY GFS AND ECMWF. GIVEN DEGREE OF SEPARATION BETWEEN
850 TEMPERATURE AND WATER TEMPERATURE (25-30C) WOULD NOT BE
SURPRISED THAT COULD END UP WITH SOME ACCUMULATING SNOW ACROSS
EASTERN PORTIONS OF THE ISLAND - POSSIBLY WITH SOME IMPRESSIVE
SNOW BURSTS. ONCE AGAIN STILL SOME UNCERTAINTY - SO DO NOT WANT TO
GO TOO FAR IN ANY DIRECTION ON THIS QUITE YET.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
FAST WSW FLOW ALOFT WEDNESDAY/WEDNESDAY NIGHT THEN WEAK RIDGING
BUILDS ACROSS ON THURSDAY. DO HAVE THE SLIGHT FOR SOME SNOW
ACROSS MAINLY INTERIOR ZONES IN RESPONSE TO A PASSING SHORTWAVE
AND WEAK WARM ADVECTION.
BETTER CHANCE FOR SOME LIGHT SNOW IS THURSDAY NIGHT WHERE A DEEPER
SHORTWAVE CROSSES THE AREA. ANOTHER SHORTWAVE MOVES IN ON FRIDAY -
WITH POTENTIAL FOR SNOW N AND RAIN/SNOW SOUTH. SOME UNCERTAINTY ON
HOW WARM LOW LEVELS GET - SO USED BLEND OF GFS/ECMWF FOR NOW.
A FRONTAL BOUNDARY STALLS NEAR BY TO CLOSE THE WEEK. WHETHER IT IS
TO THE N OR S AND HOW WAVES OF PRECIPITATION INTERACT WITH IT ARE
UNCERTAIN SO HAVE KEPT POPS RELATIVELY LOW FOR NOW AND KEPT THINGS
SNOW TO RAIN N AND A MIX TO RAIN S FROM FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WERE BASED ON A BLEND OF ALL AVAILABLE GUIDANCE AND
START OUT WELL BELOW NORMAL - MODERATE TO NEAR NORMAL BY FRIDAY
AND TO ABOVE NORMAL BY SATURDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A WARM FRONT APPROACHES THIS AFTERNOON...FOLLOWED BY A COLD FRONT
TONIGHT AND EARLY MONDAY.
LOW END MVFR OR IFR CONDITIONS LIKELY THIS AFTERNOON...WITH IFR OR
LIFR TONIGHT IN LOW CLOUDS AND FOG.
KJFK AND KISP HAVE WARMED CLOSE TO OR JUST ABOVE FREEZING. FREEZING
RAIN MOST TERMINALS SHOULD GRADUALLY CHANGE TO PLAIN RAIN...21-00Z
TIME FRAME. INTERIOR AIRPORTS MAY TAKE A LITTLE LONGER FOR THE
TRANSITION TO TAKE PLACE.
PERIODS OF RAIN EXPECTED TONIGHT.
AS FOR WINDS...LIGHT AND VARIABLE OR LIGHT EAST THROUGH LATE THIS
AFTERNOON AND INTO THE EVENING WILL BECOME SOUTHERLY TONIGHT.
SPEEDS INCREASE TONIGHT AHEAD OF THE COLD FRONT.
WINDS SHIFT AFTER 12-15Z MONDAY MORNING BEHIND THE FRONT. GUSTS 20
TO 30 KTS EXPECTED BEHIND THE FRONT.
LOW LEVEL WIND SHEAR 45 TO 50 KTS EXPECTED AFTER MIDNIGHT TONIGHT
INTO THE EARLY MORNING...MAINLY BEFORE 12Z.
.OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY...
.MON AFTERNOON-TUE...VFR. W WINDS G25-35KT...HIGHEST MON NIGHT-TUE.
.WED...VFR. W WINDS G20KT IN THE MORNING.
.THU...VFR. CHANCE OF MVFR OR LOWER CONDITIONS IN LIGHT SNOW BY LATE
DAY OR AT NIGHT.
.FRI...SUB-VFR POSSIBLE EARLY IN SNOW TO RAIN.
&&
.MARINE...
SCA WILL REMAIN UP FOR THE 2 EASTERN OCEAN WATERS INTO THIS
EVENING FOR 4-6 FT SEAS.
INCREASING SE FLOW TONIGHT IN COMBINATION WITH RESIDUAL SWELLS
SHOULD PUSH OCEAN SEAS BACK OVER 5 FT TONIGHT. GUSTS OVER 25 KT
SHOULD FOLLOW LATE TONIGHT INTO MON MORNING. SCA ALSO IN EFFECT
FOR THE OCEAN FOR THIS TIME FRAME.
GALES ARE EXPECTED AFTER COLD FROPA ON MON...BUT TIMING IS IN
QUESTION. THEY COULD START AS EARLY AS MON AFTERNOON BUT THINK
GREATER LIKELIHOOD EXISTS FOR MON NIGHT-TUE...AND A GALE WATCH HAS
BEEN ISSUED FOR THE OCEAN FOR THIS TIME FRAME. GALES ARE ALSO LIKELY
ON THE HARBOR/SOUND/BAYS FOR PART OF THIS TIME...AVE HELD OFF ON
WATCH THERE FOR NOW.
THE COMBINATION OF COLD WATER TEMPERATURES AND STRONG WINDS WILL
LIKELY LEAD TO FREEZING SPRAY MON NIGHT-TUE NIGHT...AND A FREEZING
SPRAY ADVISORY MAY EVENTUALLY BE NEEDED. BLOWOUT TIDES WILL ALSO BE
A CONCERN ON THE WESTERN SOUND AND THE BAYS OF LONG ISLAND DURING
THE TUE NIGHT LOW TIDE CYCLE.
SCA CONDS ARE LIKELY INTO WED MORNING ON THE NON-OCEAN WATERS WITH
SEAS REMAINING ABOVE 5 FT ON THE OCEAN WATERS INTO WED NIGHT.
&&
.HYDROLOGY...
WIDESPREAD RAIN OVER THE REGION...MAINLY FROM THIS AFTERNOON INTO
EARLY MONDAY AFTERNOON...WILL RESULT IN 2/3 TO 9/10 INCH QPF. THE
COMBINATION OF LOCALLY HEAVY RAIN AND MELTING SNOW MAY RESULT IN
MINOR FLOODING OF URBAN AND POOR DRAINING LOCATIONS.
&&
.EQUIPMENT...
THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS
OUT OF SERVICE.
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY
BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER
RADIO STATION KWO35 IS OUT OF SERVICE.
DURING THE 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 TEST OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR
CTZ005>012.
NY...FREEZING RAIN ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ072>075-078>081-176>179.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ067>071.
NJ...FREEZING RAIN ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NJZ006-106-108.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ002-
004-103>105-107.
MARINE...GALE WATCH FROM MONDAY EVENING THROUGH TUESDAY AFTERNOON FOR
ANZ350-353-355.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST MONDAY
FOR ANZ355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...MALOIT
NEAR TERM...MPS
SHORT TERM...MALOIT
LONG TERM...MALOIT
AVIATION...PW
MARINE...GOODMAN
HYDROLOGY...MALOIT
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1128 AM EST SUN JAN 5 2014
.SYNOPSIS...
AN AREA OF LOW PRESSURE RIDES NORTHEAST ALONG A COLD FRONT
STRETCHING FROM THE CENTRAL GULF COAST INTO QUEBEC INTO MONDAY.
ITS ASSOCIATED WARM FRONT LIFTS THROUGH THE AREA
TONIGHT...FOLLOWED BY ITS TRAILING ARCTIC FRONT BY MONDAY
AFTERNOON. ARCTIC AIR THEN POURS INTO THE REGION INTO THE MIDDLE
OF THE WEEK. THE WEATHER WILL BE UNSETTLED FOR THE LATTER PART OF
THE WEEK AS A WEAK FRONTAL BOUNDARY STALLS NEAR THE REGION.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
LIGHT FREEZING RAIN AND LIGHT FREEZING DRIZZLE CONTINUES TO SPREAD
INLAND...WHERE TEMPS ARE IN THE TEENS TO MID 20S. LONG ISLAND IS
BEGINNING TO RISE ABOVE FREEZING...BUT THOSE TEMPS ARE TAKEN AT 6
FT...AND WITH SNOWPACK ON THE GROUND...THINK TEMPS AT THE GROUND
ARE STILL AT OR BELOW FREEZING. WILL TAKE SOME TIME FOR THE WARMER
AIR TO SPREAD NORTH...AS SE WINDS DO NOT LOOK TO INCREASE UNTIL
LATE AFTERNOON/EARLY EVENING. AS SUCH...MODIFIED THE FREEZING RAIN
ADVISORY TO EXTEND FOR NYC...NEARBY NJ...AND LONG ISLAND UNTIL 4
PM AND EVERYBODY ELSE UNTIL 7 PM. LATEST HRRR AND 12Z NAM
INDICATING A PERIOD OF DRYING BY FROM 21Z-00Z...SO IT IS LIKELY
THAT THE ADVISORY CAN BE CANCELLED PRIOR TO THAT.
TRAVEL IS TREACHEROUS...AND THERE HAVE BEEN NUMEROUS TRAFFIC
ACCIDENTS REPORTED ACROSS THE AREA DUE TO THE ICED UP ROADS.
ICE ACCUMULATIONS SHOULD AVERAGE A TRACE TO MAYBE A FEW
HUNDREDTHS OF AN INCH.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
ANY LINGERING FREEZING RAIN OVER ORANGE COUNTY SHOULD TURN TO ALL
RAIN BY EARLY EVENING.
ISENTROPIC LIFT STEADILY INCREASES IN DEPTH/SATURATION...COUPLED
WITH A 45-60 KT LOW LEVEL JST PASSING OVER THE REGION...WILL SEE
AN INCREASE IN THE COVERAGE AND INTENSITY OF THE RAIN WILL DO
LIKEWISE FROM TONIGHT INTO MONDAY MORNING. SEE HYDROLOGY SECTION
OF THE AFD FOR DETAILS AND IMPACT.
RAINFALL COMES TO AN END WITH THE PASSAGE OF THE ARCTIC FRONT
MAINLY DURING THE MORNING HOURS ON MONDAY. COULD SEE SOME SHOWERS
IMMEDIATELY IN ITS WAKE - EITHER SHRA/SHSN OR BOTH DEPENDING ON
EXACTLY HOW FAST THE TEMPERATURES FALL OF NEAR THE SURFACE. HAVE
THE POTENTIAL FOR A FLASH FREEZE IN THE AFTERNOON - ESPECIALLY IN
AREAS FROM NYC ON N/W WHERE TEMPERATURES FALL INTO THE
TEENS/AROUND 20 BY EVENING. LESS CERTAIN FARTHER E WHERE
TEMPERATURES ONLY FALL INTO THE 20S.
BITTERLY COLD AIR THEN MOVES IN MONDAY NIGHT-TUESDAY NIGHT...
LOWS MONDAY NIGHT FROM THE LOW SINGLE DIGITS FAR NW TO MID TEENS
FAR E...HIGHS TUESDAY FROM THE UPPER SINGLE DIGITS FAR NW TO
AROUND 20 FAR E...AND LOWS TUESDAY NIGHT MAINLY FROM 5 BELOW TO 5
ABOVE - A TAD HIGHER IN NYC/THE TWIN FORKS/AND AT THE IMMEDIATE
COAST.
WINDS TO POSSIBLY WIND ADVISORY LEVELS ACROSS NYC/LONG ISLAND AND
HIGHER ELEVATIONS ACROSS THE INTERIOR...AND JUST BELOW ADVISORY
LEVELS ELSEWHERE WILL PRODUCE POTENTIALLY DANGEROUS WIND CHILLS
MONDAY NIGHT-TUESDAY NIGHT. WIND CHILLS MONDAY NIGHT WILL FALL TO
-15 TO -20 ACROSS NW INTERIOR ZONES...-5 T0 -15 ACROSS MOST OF THE
REMAINDER OF THE AREA...EXCEPT AROUND 0 FAR EASTERN AREAS. WIND
CHILLS MODERATE SLIGHTLY DURING THE DAY ON TUESDAY TO FROM -15 TO
0 (HIGHEST FAR E). DIMINISHING WINDS TUESDAY NIGHT WILL LIMIT WIND
CHILLS TO GENERALLY -5 TO -15 (LOWEST FAR NW)...EXCEPT -5 TO 0 FAR
E ZONES.
WIND CHILL ADVISORIES WILL LIKELY BE NEEDED FOR WESTERN NE NJ
ZONES AND MOST OF THE LOWER HUDSON VALLEY FROM MONDAY NIGHT INTO
TUESDAY MORNING. STILL SOME UNCERTAINTY ON EXACTLY HOW THE WINDS
AND TEMPERATURES PLAY OUT - GUIDANCE TENDS TO BE TOO WARM IN
EXTREME EVENTS LIKE THIS - ESPECIALLY THIS FAR OUT - SO EVEN
THOUGH IT WAS UNDERCUT USING A BLEND OF MODEL 2-METER TEMPERATURES
NOT SURE IF HAVE GONE COLD ENOUGH. BECAUSE OF THIS - STILL WILL
HIGHLIGHT THE CHANCE OF WIND CHILLS AROUND -25 ACROSS INTERIOR
ZONES IN THE HWO MONDAY NIGHT/TUESDAY MORNING.
THE STRONG WNW WINDS AND COLD AIR IN THE LOW LEVELS FROM MONDAY
NIGHT INTO TUESDAY NIGHT WILL ALSO CREATE CONDITIONS RIPE FOR SOUND
EFFECT SNOW. AS TIME GOES ON CONFIDENCE INCREASES - SO HAVE
INCREASED POPS OVER THE TWIN FORKS TO CHANCE ON TUESDAY AFTERNOON
- AS SUGGESTED BY GFS AND ECMWF. GIVEN DEGREE OF SEPARATION BETWEEN
850 TEMPERATURE AND WATER TEMPERATURE (25-30C) WOULD NOT BE
SURPRISED THAT COULD END UP WITH SOME ACCUMULATING SNOW ACROSS
EASTERN PORTIONS OF THE ISLAND - POSSIBLY WITH SOME IMPRESSIVE
SNOW BURSTS. ONCE AGAIN STILL SOME UNCERTAINTY - SO DO NOT WANT TO
GO TOO FAR IN ANY DIRECTION ON THIS QUITE YET.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
FAST WSW FLOW ALOFT WEDNESDAY/WEDNESDAY NIGHT THEN WEAK RIDGING
BUILDS ACROSS ON THURSDAY. DO HAVE THE SLIGHT FOR SOME SNOW
ACROSS MAINLY INTERIOR ZONES IN RESPONSE TO A PASSING SHORTWAVE
AND WEAK WARM ADVECTION.
BETTER CHANCE FOR SOME LIGHT SNOW IS THURSDAY NIGHT WHERE A DEEPER
SHORTWAVE CROSSES THE AREA. ANOTHER SHORTWAVE MOVES IN ON FRIDAY -
WITH POTENTIAL FOR SNOW N AND RAIN/SNOW SOUTH. SOME UNCERTAINTY ON
HOW WARM LOW LEVELS GET - SO USED BLEND OF GFS/ECMWF FOR NOW.
A FRONTAL BOUNDARY STALLS NEAR BY TO CLOSE THE WEEK. WHETHER IT IS
TO THE N OR S AND HOW WAVES OF PRECIPITATION INTERACT WITH IT ARE
UNCERTAIN SO HAVE KEPT POPS RELATIVELY LOW FOR NOW AND KEPT THINGS
SNOW TO RAIN N AND A MIX TO RAIN S FROM FRIDAY NIGHT INTO SATURDAY.
TEMPERATURES WERE BASED ON A BLEND OF ALL AVAILABLE GUIDANCE AND
START OUT WELL BELOW NORMAL - MODERATE TO NEAR NORMAL BY FRIDAY
AND TO ABOVE NORMAL BY SATURDAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
A WARM FRONT APPROACHES TODAY...FOLLOWED BY A COLD FRONT TONIGHT AND
MONDAY.
MVFR CIGS LATE THIS MORNING. FREEZING RAIN OR DRIZZLE MOST AIRPORTS.
TIMING OF PLAIN RAIN COULD BE OFF BY AN HOUR OR TWO. MOST WATCH SFC
TEMPS AS THEY RISE TOWARD THE FREEZING MARK.
STILL EXPECT IFR OR EVEN LIFR LATER THIS AFTERNOON IN LIGHT RAIN.
LOW CLOUDS..RAIN AND FOG EXPECTED TONIGHT.
LIGHT WINDS ARE EXPECTED TO TURN TOWARD THE E-SE THIS
AFTERNOON...THEN BECOME SE 10-15 KT THIS EVENING. LOW LEVEL WIND
SHEAR INCLUDED FOR TONIGHT AS WINDS ALOFT STRENGTHEN.
.OUTLOOK FOR 12Z MONDAY THROUGH THU...
.MON MORNING...IFR OR LIFR IN RAIN AND FOG.
.MON AFTERNOON-TUE...BECOMING VFR. W WINDS G25-35KT...HIGHEST MON
NIGHT-TUE.
.WED...VFR. W WINDS G20KT IN THE MORNING.
.THU...VFR. CHANCE OF MVFR OR LOWER CONDS IN LIGHT SNOW BY LATE DAY
OR AT NIGHT.
&&
.MARINE...
SCA WILL REMAIN UP FOR THE 2 EASTERN OCEAN WATERS INTO THIS
EVENING FOR 4-6 FT SEAS.
INCREASING SE FLOW TONIGHT IN COMBINATION WITH RESIDUAL SWELLS
SHOULD PUSH OCEAN SEAS BACK OVER 5 FT TONIGHT. GUSTS OVER 25 KT
SHOULD FOLLOW LATE TONIGHT INTO MON MORNING. SCA ALSO IN EFFECT
FOR THE OCEAN FOR THIS TIME FRAME.
GALES ARE EXPECTED AFTER COLD FROPA ON MON...BUT TIMING IS IN
QUESTION. THEY COULD START AS EARLY AS MON AFTERNOON BUT THINK
GREATER LIKELIHOOD EXISTS FOR MON NIGHT-TUE...AND A GALE WATCH HAS
BEEN ISSUED FOR THE OCEAN FOR THIS TIME FRAME. GALES ARE ALSO LIKELY
ON THE HARBOR/SOUND/BAYS FOR PART OF THIS TIME...AVE HELD OFF ON
WATCH THERE FOR NOW.
THE COMBINATION OF COLD WATER TEMPERATURES AND STRONG WINDS WILL
LIKELY LEAD TO FREEZING SPRAY MON NIGHT-TUE NIGHT...AND A FREEZING
SPRAY ADVISORY MAY EVENTUALLY BE NEEDED. BLOWOUT TIDES WILL ALSO BE
A CONCERN ON THE WESTERN SOUND AND THE BAYS OF LONG ISLAND DURING
THE TUE NIGHT LOW TIDE CYCLE.
SCA CONDS ARE LIKELY INTO WED MORNING ON THE NON-OCEAN WATERS WITH
SEAS REMAINING ABOVE 5 FT ON THE OCEAN WATERS INTO WED NIGHT.
&&
.HYDROLOGY...
WIDESPREAD RAIN OVER THE REGION...MAINLY FROM THIS AFTERNOON INTO
EARLY MONDAY AFTERNOON...WILL RESULT IN 2/3 TO 9/10 INCH QPF. THE
COMBINATION OF LOCALLY HEAVY RAIN AND MELTING SNOW MAY RESULT IN
MINOR FLOODING OF URBAN AND POOR DRAINING LOCATIONS.
&&
.EQUIPMENT...
THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS
OUT OF SERVICE.
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY
BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER
RADIO STATION KWO35 IS OUT OF SERVICE.
DURING THE 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 TEST OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR
CTZ005>012.
NY...FREEZING RAIN ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NYZ072>075-078>081-176>179.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ067>071.
NJ...FREEZING RAIN ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
NJZ006-106-108.
FREEZING RAIN ADVISORY UNTIL 7 PM EST THIS EVENING FOR NJZ002-
004-103>105-107.
MARINE...GALE WATCH FROM MONDAY EVENING THROUGH TUESDAY AFTERNOON FOR
ANZ350-353-355.
SMALL CRAFT ADVISORY FROM 6 PM THIS EVENING TO 6 PM EST MONDAY
FOR ANZ355.
SMALL CRAFT ADVISORY UNTIL 6 PM EST MONDAY FOR ANZ350-353.
&&
$$
SYNOPSIS...MALOIT
NEAR TERM...MPS
SHORT TERM...MALOIT
LONG TERM...MALOIT
AVIATION...GOODMAN
MARINE...GOODMAN
HYDROLOGY...MALOIT
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS ALBANY NY
1008 AM EST SUN JAN 5 2014
.SYNOPSIS...
A STORM WILL ORGANIZE IN THE TENNESSEE VALLEY LATE SUNDAY AND TRACK
TO THE SAINT LAWRENCE VALLEY MONDAY...BRINGING RAIN AND A WINTRY MIX
OF PRECIPITATION TO THE REGION. BEHIND IT...ANOTHER FRIGID SURGE OF
ARCTIC AIR WILL MOVE INTO OUR REGION AND LAST THROUGH THE MIDDLE OF
THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAJOR CHANGES HAVE BEEN MADE TO THE GRIDDED DATABASE THROUGH EARLY
THIS EVENING. GIVEN THAT THIS MORNING/S TEMPS DROPPED DOWN INTO
THE SINGLE DIGITS ABOVE AND BELOW ZERO AREAWIDE...DESPITE SUNSHINE
THROUGH MIDDAY...THE DEEP SNOWPACK ON THE GROUND AND VERY COLD
START WILL GREATLY LIMIT THE ABILITY OF THE LOWER ATMOSPHERE TO
WARM MUCH TODAY. HAVE LOWERED MAX TEMPS BY AT LEAST 5 DEGREES
AREAWIDE...AND IN SOME PLACES BY AS MUCH AS 10 DEGREES. EXPECT
MOST AREAS TO ONLY REACH THE 20S TO LOWER 30S...COLDEST FOR AREAS
NORTH OF THE MOHAWK RIVER.
THIS POSES AN INCREASING THREAT FOR FREEZING RAIN LATE THIS
AFTERNOON ACROSS CENTRAL AND SOUTHERN AREAS...WHERE NO ADVISORY
CURRENTLY IS IN EFFECT. HAVE SLOWED DOWN THE TIMING OF THE
PRECIPITATION ONSET...UNTIL EARLY/MID AFTERNOON FOR SOUTHERN
AREAS...AND LATE AFTERNOON OR EARLY EVENING FURTHER NORTH. AT THIS
TIME...CAN NOT RULE OUT SOME FREEZING RAIN POTENTIAL...PERHAPS A
LIGHT GLAZE...EVEN FOR SOUTHERN AREAS LATE THIS AFTERNOON...AS
WELL AS FURTHER NORTH INTO THE CATSKILLS/SCHOHARIE VALLEY AND
GREATER CAPITAL DISTRICT. WE MAY NEED TO ISSUE A FREEZING RAIN
ADVISORY BY MIDDAY FOR THESE AREAS SHOULD TEMPS FAIL TO RISE
MUCH...AND PRECIPITATION KEEPS EXPANDING NORTHWARD.
THE CURRENT BAND OF LIGHT PRECIPITATION TO OUR SOUTH...ACROSS
NJ...NYC METRO AND LI...APPEARS TO BE INDUCED BY A BURST OF
ISENTROPIC LIFT ALONG THE 285 K SFC. THE RUC13 SEEMS TO BE
HANDLING THIS SOMEWHAT REASONABLY WELL...AND SUGGESTS THAT THIS
FORCING REMAINS MAINLY SOUTH AND EAST OF OUR CWA THROUGH AT LEAST
MIDDAY...ALTHOUGH MAY THEN EXPAND NORTHWARD LATER THIS AFTERNOON.
TRENDS WILL BE WATCHED.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
THIS WILL BE AN ACTIVE WEATHER PERIOD AS THE STORM PASSES BY WELL TO
OUR WEST...BUT THE COLD FRONT ASSOCIATED WITH THIS SYSTEM WILL MOVE
ACROSS THE REGION MONDAY MORNING AND BRING ANOTHER SURGE OF BITTERLY
COLD ARCTIC AIR TO THE REGION MONDAY NIGHT THROUGH THE MIDDLE OF THE
WEEK.
THIS SCENARIO WILL RESULT IN TEMPS RISING TONIGHT ACROSS THE REGION
AS THE SOUTHERLY FLOW INCREASES AHEAD OF THE COLD FRONT. BY SUNRISE
MONDAY EXPECT TEMPS TO BE IN THE MID 30S TO MID 40S ACROSS THE
FORECAST AREA...WHICH WILL ALSO BE THE HIGH TEMP READING FOR MONDAY.
ANY LEFTOVER MIXED PCPN EARLY TONIGHT WILL BECOME ALL RAIN IN ALL
AREAS BY AROUND MIDNIGHT...WITH RAIN CONTINUING UNTIL THE FRONT
PASSES THROUGH MONDAY MORNING. A PERIOD OF SNOW IS POSSIBLE BEHIND
THE FRONT...ESPECIALLY OVER THE ADIRONDACKS AND WESTERN MOHAWK
VALLEY WHERE AN INCH OR TWO COULD ACCUMULATE. ELSEWHERE...LITTLE
MORE THAN A DUSTING TO HALF AN INCH MAY ACCUMULATE BEFORE PCPN ENDS.
TEMPS WILL DROP DURING THE DAY...REACHING THE 20S AND LOWER 30S BY
SUNSET. BY TUESDAY MORNING LOWS WILL BE IN THE 10 BELOW ZERO TO 10
ABOVE ZERO RANGE...THEN ONLY RISE SLIGHTLY TO HIGHS IN THE SINGLE
DIGITS AND LOW TEENS ON TUESDAY. THE TEMPS FORECAST FOR MONDAY NIGHT
AND TUESDAY ARE CONSIDERABLY LOWER THAN THOSE FORECAST BY THE
MAV/MET MOS GUIDANCE PACKAGES...AND ARE MORE IN LINE WITH THE ECMWF
MOS GUIDANCE. WESTERLY WINDS WILL BE QUITE GUSTY BEHIND THE FRONT
WITH GUSTS OF 30 TO 35 MPH POSSIBLE MONDAY NIGH AND TUESDAY. HAVE
ISSUED A WIND CHILL WATCH FOR AREAS WEST OF THE HUDSON
VALLEY...INCLUDING NORTHERN WARREN COUNTY...WHERE WIND CHILL
READINGS MAY DROP TO 30 BELOW ZERO OR LESS LATER MONDAY NIGHT INTO
TUESDAY. ELSEWHERE...WIND CHILL READINGS SHOULD DROP TO ADVISORY
LEVELS DURING THAT TIME PERIOD.
THE FINAL SIGNIFICANT WEATHER CONCERN WILL BE A PROLONGED LAKE
EFFECT EVENT ACROSS NORTHERN HERKIMER AND HAMILTON COUNTIES MONDAY
NIGHT INTO WEDNESDAY...AND HAVE ISSUED A LAKE EFFECT SNOW WATCH FOR
THOSE TWO ZONES.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
THE PERIOD STARTS OUT TUESDAY NIGHT WITH THE REGION STILL IN THE
GRIP OF A BITTERLY COLD AIR MASS WITH A PERSISTENT WESTERLY BREEZE
CONTINUING TO RESULT IN VERY LOW WIND CHILLS VALUES. ADDITIONAL WIND
CHILL ADVISORIES FOR MUCH OF THE AREA...AND POSSIBLY SOME WARNINGS
FOR THE CATSKILLS...MAY BE NEEDED TUESDAY NIGHT INTO WEDNESDAY
MORNING. ALSO...LAKE EFFECT SNOW WILL BE ONGOING ACROSS THE WESTERN
ADIRONDACKS. BASED ON THE EXPECTED QUASI-STATIONARY WESTERLY FLOW
REGIME...NORTHERN HERKIMER AND HAMILTON COUNTIES LOOK TO CONTINUE TO
RECEIVE ACCUMULATING SNOWFALL FROM THE RATHER LONG DURATION EVENT
INTO WEDNESDAY. THE LAKE EFFECT SNOW WATCH WILL CONTINUE INTO
WEDNESDAY.
COLD TEMPERATURES WILL ALSO PERSIST ON WEDNESDAY...WITH HIGHS
GENERALLY IN THE TEENS AND WESTERLY BREEZE CONTINUING. OUTSIDE OF
LAKE EFFECT SNOW OVER THE WESTERN ADIRONDACKS...IT SHOULD REMAIN DRY
ACROSS THE REST OF THE AREA. THE COLDEST AIR ALOFT WILL BE ERODING
OVER THE AREA WITH A SLOW MODERATION EXPECTED THROUGH THE REST OF
THE WEEK.
THE NEXT CHANCE OF PRECIP ARRIVES THURSDAY NIGHT INTO EARLY
FRIDAY...AS WARM ADVECTION/ISENTROPIC LIFT DEVELOPS ON THE BACK SIDE
OF HIGH PRESSURE DEPARTING OFF THE NEW ENGLAND COAST. THERE IS
UNCERTAINTY REGARDING QPF...AS GFS INDICATING RATHER HEFTY QPF FOR
SUCH AN INNOCUOUS SYSTEM WITH NO ORGANIZED CYCLONE OR INTENSE
BAROCLINIC ZONE. WE WOULD TEND TO FAVOR THE ECMWF DEPICTING LIGHTER
QPF IN THIS CASE. SO WILL STILL ONLY MENTION CHANCE POPS AT THIS
TIME WITH QPF EXPECTED TO BE ON THE LIGHTER SIDE. TEMPERATURE
PROFILES LOOK COLD ENOUGH FOR ALL SNOW.
ONCE THIS SYSTEM DEPARTS LATER FRIDAY...MODELS HAVE TRENDED DRIER
FOR FRIDAY NIGHT INTO SATURDAY...AS RIDGING DEVELOPS TO OUR SOUTH
AND OUR AREA GETS INTO A MILDER WESTERLY FLOW REGIME. AS A
RESULT...HAVE LOWERED POPS TO SLIGHT CHANCE FOR THIS TIME FRAME.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS TO START THE PERIOD THIS MORNING...THEN STRATUS
CLOUDS WILL INCREASE FROM SOUTH TO NORTH DURING THE AFTERNOON WITH
MVFR CIGS. LIGHT PRECIP IS EXPECTED TO DEVELOP LATE THIS AFTERNOON
INTO THIS EVENING...AS MOISTURE INCREASES AHEAD OF A LOW PRESSURE
SYSTEM TRACKING FROM THE OHIO VALLEY INTO THE EASTERN GREAT LAKES.
CONDITIONS WILL EVENTUALLY DETERIORATE TO IFR DURING THE EVENING AS
STEADIER PRECIP DEVELOPS. PRECIP TYPE EXPECTED TO BE PLAIN FOR
KALB/KPOU BUT THERE IS A LOW PROBABILITY FOR BRIEF FREEZING RAIN AT
THE ONSET. SLEET/FREEZING RAIN EXPECTED AT KPSF INITIALLY BEFORE
CHANGING TO RAIN...WHILE KGFL WILL HAVE SURFACE TEMPS AT OR BELOW
FREEZING UNTIL LATE TONIGHT...AND THUS FREEZING RAIN EXPECTED THERE
THROUGH 08Z MONDAY BEFORE CHANGING TO RAIN.
WINDS WILL BE VARIABLE AROUND 5 KT OR LESS INTO THIS EVENING...THEN
WILL GENERALLY SHIFT TO THE SOUTHEAST AT 5-10 KT. LOW LEVEL WIND
SHEAR WILL DEVELOP BY THIS EVENING AS A SOUTHERLY JET MOVES OVERHEAD
WITH 50 KT OF WIND AT 1500 FT AGL.
OUTLOOK...
MONDAY: HIGH OPERATIONAL IMPACT. BREEZY. DEFINITE RA...SN.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
TUESDAY: MODERATE OPERATIONAL IMPACT. WINDY. NO SIG WX.
TUESDAY NIGHT: LOW OPERATIONAL IMPACT. BREEZY. NO SIG WX.
WEDNESDAY TO WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SN.
THURSDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SN.
FRIDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC PROBLEMS ARE EXPECTED OVER THE NEXT FIVE
DAYS.
A STORM WILL ORGANIZE IN THE TENNESSEE VALLEY LATE SUNDAY AND
TRACK TO THE SAINT LAWRENCE VALLEY MONDAY...BRINGING RAIN AND A
WINTRY MIX OF PRECIPITATION. BEHIND IT ANOTHER FRIGID SURGE OF
ARCTIC AIR WILL MOVE INTO OUR REGION AND LAST THROUGH MID WEEK.
WHILE THERE EXISTS SOME UNCERTAINTY OF TIMING AND PTYPE...EXPECT
ONLY MINOR IMPACTS ON THE RIVERS...EVEN IN AREAS WHERE MOSTLY RAIN
FALLS. THE SNOW COVER SHOULD BE ABLE TO ABSORB MUCH OF THE
RAINFALL...AND TEMPERATURES IN THESE AREAS WILL BE ABOVE FREEZING
FOR ONLY ABOUT 24 HOURS. DURING THE MID WEEK PERIOD ICE ON THE
RIVERS WILL BECOME THICKER AS ANOTHER COLD AIRMASS SETTLES OVER OUR
REGION.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...WIND CHILL WATCH FROM LATE MONDAY NIGHT THROUGH TUESDAY
AFTERNOON FOR NYZ032-033-038>040-042-047-048-051-058-063-
082.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
MONDAY FOR NYZ032-033-038>043-082>084.
LAKE EFFECT SNOW WATCH FROM MONDAY EVENING THROUGH WEDNESDAY
AFTERNOON FOR NYZ032-033.
MA...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
MONDAY FOR MAZ001-025.
VT...WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM EST
MONDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...KL/GJM
NEAR TERM...KL/GJM
SHORT TERM...GJM
LONG TERM...JPV
AVIATION...JPV
HYDROLOGY...11
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
1043 AM EST Sun Jan 5 2014
.NEAR TERM [Rest of Today]...
Some cloud cover is expected to linger through much of the day,
with mostly cloudy skies likely in most locations by sunset. This
should keep temperatures relatively cool, especially across our
far western and northern areas where low stratus may be more
persistent. Highs were tweaked down slightly into the upper 50s in
those areas. It should be a fairly warm day elsewhere with highs
near or slightly above normal values. Enjoy the relatively warm
day, as the cold air arrives late tonight and tomorrow morning!
Although daytime PoPs remain concentrated over the water, we did
add some isolated sprinkles to the rest of the area during the
daytime as the HRRR and local TAE WRF-ARW both show a scattering
of light echoes on simulated reflectivity through the day.
&&
.PREV DISCUSSIONS [550 AM EST]...
SHORT TERM [Tonight Through Tuesday]...
Overall, there was little change to the previous forecast.
Guidance is still heavily clustered around very cold temperatures
and wind chills across the area as an Arctic front moves through
the area. The front will move through the western areas late
tonight and the remainder of the area early Monday, bringing with
it the coldest airmass we have felt in a long time given the
expected combination of temperature and wind. The recently issued
freeze warning, hard freeze watch, wind chill watch, and gale
watch contain the details of the expected impacts of this event.
LONG TERM [Tuesday Night Through Saturday]...
Tuesday night will likely see another hard freeze over most of the
area, although winds will be lighter so the wind chill will not be
as low as Monday night. As the high pressure pushes off the east
coast Wednesday through Thursday, winds will shift to the east and
then south and once again return warmer, moist air to the region.
As an upper level disturbance propagates through otherwise mostly
zonal flow and develops another mid and upper level trough,
another cold front will begin to develop and then move across our
area later next week. Chances for rain increase through the
weekend, with widespread chances (30-50%) Friday through Saturday.
AVIATION...
[Through 12Z Monday] Very complex and challenging aviation fcst
over the next 24 hrs, as much of the model guidance did very
poorly overnight. However, this was generally a positive
development for the individual terminals, as the "gloom and doom"
fcst suggested by many of the models and guidance never did
materialize. Although ABY and VLD have finally reached low end
MVFR level CIGS with still the possibility of a brief period of
IFR level conditions, TLH, ECP, and DHN have been mired in VFR
level CIGS which was quite an improvement over guidance. While
these CIGS may not break out much (or at all) during the day
today, am leaning towards improving ABY and VLD back up to VFR
levels for some period of time this afternoon. For later tonight
and early Monday morning, we could see somewhat similar results,
although the probabilities for more widespread MVFR and IFR
conditions do appear likely before the passage of the Arctic cold
front.
MARINE...
Conditions will rapidly deteriorate late tonight as a strong,
Arctic cold front crosses the region. Frequent gale force gusts
out of the northwest are a possibility behind this front through
the day on Monday over the western two-thirds of the area, so a
gale watch has been posted. Winds will likely remain at least 20
knots through Tuesday afternoon, and exercise caution conditions
will
FIRE WEATHER...
No fire weather concerns are expected for both today and Monday,
and although extremely low dewpoints are expected on Tuesday,
these will likely be offset by very low afternoon temperatures and
other parameters which will not be compatible with Red Flag
conditions. Therefore, although Tuesday afternoon does bear
watching at this time, a Fire Weather Watch or Red Flag Warning is
not anticipated.
HYDROLOGY...
Only the Apalachicola River at Blountstown remains in minor flood
stage, and it is expected to slowly decline below flood stage by
Tuesday morning. No additional flooding is expected this week.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 69 44 44 20 38 / 10 40 10 0 0
Panama City 68 41 41 23 38 / 20 40 10 0 0
Dothan 58 31 35 15 31 / 10 40 10 0 0
Albany 59 39 39 15 32 / 10 40 10 0 0
Valdosta 64 50 50 20 36 / 10 40 30 10 0
Cross City 74 62 62 22 41 / 10 30 30 10 0
Apalachicola 65 46 46 24 38 / 20 40 10 0 0
&&
.TAE Watches/Warnings/Advisories...
FL...Hard Freeze Watch from Monday evening through Tuesday morning
for Calhoun-Coastal Bay-Coastal Dixie-Coastal Franklin-
Coastal Gulf-Coastal Jefferson-Coastal Taylor-Coastal
Wakulla-Gadsden-Inland Bay-Inland Dixie-Inland Franklin-
Inland Gulf-Inland Jefferson-Inland Taylor-Inland Wakulla-
Lafayette-Leon-Liberty-Madison-South Walton.
Freeze Warning from 4 AM to Noon CST Monday for Central Walton-
Holmes-Inland Walton-Jackson-Washington.
Hard Freeze Watch from Monday afternoon through Tuesday
afternoon for Central Walton-Holmes-Inland Walton-Jackson-
Washington.
GA...Hard Freeze Watch from Monday evening through Tuesday morning
for Ben Hill-Berrien-Brooks-Colquitt-Cook-Decatur-Grady-
Irwin-Lanier-Lowndes-Mitchell-Thomas-Tift-Turner-Worth.
Wind Chill Watch from late Monday night through Tuesday morning
for Baker-Ben Hill-Berrien-Calhoun-Clay-Colquitt-Cook-
Dougherty-Early-Irwin-Lanier-Lee-Miller-Mitchell-Quitman-
Randolph-Terrell-Tift-Turner-Worth.
Freeze Warning from 5 AM to 1 PM EST Monday for Baker-Calhoun-
Clay-Dougherty-Early-Lee-Miller-Quitman-Randolph-Seminole-
Terrell.
Hard Freeze Watch from Monday afternoon through Tuesday
afternoon for Baker-Calhoun-Clay-Dougherty-Early-Lee-Miller-
Quitman-Randolph-Seminole-Terrell.
AL...Wind Chill Watch from late Monday night through Tuesday morning
for Coffee-Dale-Geneva-Henry-Houston.
Freeze Warning from 4 AM to Noon CST Monday for Coffee-Dale-
Geneva-Henry-Houston.
Hard Freeze Watch from Monday afternoon through Tuesday
afternoon for Coffee-Dale-Geneva-Henry-Houston.
GM...Gale Watch from Monday morning through Monday evening for
Coastal waters From Ochlockonee River to Apalachicola FL
out to 20 NM-Coastal waters from Apalachicola to Destin FL
out 20 NM-Waters from Suwannee River to Apalachicola FL
from 20 to 60 NM-Waters from Apalachicola to Destin FL from
20 to 60 NM.
&&
$$
NEAR TERM...LAMERS
SHORT TERM...DVD
LONG TERM...CAMP/DVD
AVIATION...GOULD
MARINE...DVD
FIRE WEATHER...GOULD
HYDROLOGY...DVD
AREA FORECAST DISCUSSION...UPDATED
NWS CHICAGO/ROMEOVILLE IL
1134 AM CST SUN JAN 5 2014
.DISCUSSION...
1130 AM CST
HAVE MADE SOME ADJUSTMENTS TO SNOWFALL FORECASTS BASED ON THE
PLETHORA OF REPORTS THROUGH EARLY THIS MORNING...AND BETTER
REFINING THE AREAL COVERAGE OF THE HEAVIEST SNOW THIS AFTERNOON.
NO CHANGES MADE TO HEADLINES BESIDES CANCELLING THE WINTER WEATHER
ADVISORY FOR FAR NORTHERN IL.
PICTURESQUE WATER VAPOR IMAGE LATE THIS MORNING WITH THE STRONG
UPPER TROUGH MOVING EAST FROM THE OZARKS AND A COUPLED UPPER JET
IN ADVANCE DIRECTLY OVERHEAD AND OWING TO SUBSTANTIAL LIFT. THIS
HAS ENABLED MODERATE TO HEAVY SNOW TO EXPAND QUICKLY NORTHEAST
FROM SOUTHWEST/CENTRAL IL INTO THE CWA...MAINLY EAST OF
I-55...WITH MOST OBSERVATIONS AT ONE HALF MILE VISIBILITY AND
OCCASIONALLY A FEW LOWER. THIS IS ALONG THE 850MB
TROUGH/DEVELOPING LOW AND THE FAVORED -5C ISOTHERM IN THIS
DEVELOPING DEFORMATION AREA OF A SYSTEM.
AS THIS CONTINUES TO GRADUALLY SHIFT EAST...IT WILL TAKE THE BEST
MOISTURE WITH IT AND SHOULD ALLOW FOR THE SNOW RATIOS TO BETTER
ACROSS THE SOUTHEAST FORECAST AREA. REPORTS HAVE GENERALLY BEEN OF
A VERY WET SNOW THUS FAR. IN ADDITION...BANDED POTENTIAL ACROSS
THE SOUTHEAST HALF OF THE CWA WILL IMPROVE AS WELL AND HAVE SEEN
TRENDS OF THAT ON RADAR WITH STRIPS OF GREATER THAN 25DBZ
OCCASIONALLY DEVELOPING. EVEN HAVE SEEN TEMPORARY ONE QUARTER MILE
VISIBILITY ALL THE WAY UP AT ORD AS OF 1125 AM WITH SUCH A
TEMPORARY BAND. JUST GIVEN THE DEFORMATION PLACEMENT AND SHORT
TERM FORECASTS OF FRONTOGENESIS AND ELEVATED INSTABILITY...SEE NO
REASON THESE WILL NOT CONTINUE TO UNDULATE AROUND AND BE MOST
PERSISTENT IN THE FAR SOUTHEAST FORECAST AREA.
SO BELIEVE THAT ADDITIONAL 1-3 INCHES SHOULD BE SEEN BETWEEN I-88
AND I-55...INCLUDING CHICAGO...FOR STORM TOTALS OF 5-9 INCHES /7-9
IN CHICAGO/. WIDESPREAD 3-6 ADDITIONAL INCHES SHOULD BE SEEN
ACROSS THE SOUTHEAST FORECAST AREA THIS AFTERNOON...FOR GRAND
TOTALS OF 6-12 BASED ON WHAT HAS FALLEN. THE HIGHEST TOTAL AMOUNTS
LOOK TO BE IN NORTHERN LAKE AND PORTER COUNTIES WHICH HAD RECEIVED
4-6 LAST NIGHT...AND WHERE LAKE CONVERGENCE CONTINUES TO FEED SOME
ENHANCEMENT INTO THE AREA.
LAKE AND PORTER COUNTIES ALSO IS MOST VULNERABLE TO THE
FRICTIONLESS WIND FETCH DOWN THE LAKE FOR GUSTS OF 40 MPH WHICH
WOULD LEAD TO CONSIDERABLE BLOWING SNOW AS WELL. ALSO LAKE AND
PORTER COUNTIES ARE ALREADY RECEIVING SOME OF THE LIGHTER/LOWER
WATER CONTENT SNOW AS IT IS SO THEY WILL HAVE A HIGHER BASE. WILL
CONTINUE TO MONITOR CLOSELY IF A BLIZZARD WARNING IS NEEDED
THERE AS A COUPLE MAJOR INTERSTATES ARE NOT FAR FROM THE LAKE
SHORE. ALSO WILL CONTINUE TO MONITOR FURTHER SOUTH TOWARD KANKAKEE
AND PONTIAC AS THE SYNOPTIC ISALLOBARIC COUPLET DEVELOPS AND
PASSES LATE THIS AFTERNOON AND EVE IN TANDEM WITH THE GREATEST
COLD AIR ADVECTION. AT THIS TIME THE THOUGHT IS MUCH OF THIS EARLY
SNOW HAS BEEN TOO WET OF A CONTENT TO BE WIDESPREAD BLOWING...AND
ONCE IT DOES THE ACTUAL FALLING SNOW WILL HAVE CEASED. SO THAT MAY
RESULT IN MORE GROUND BLIZZARD TYPE CONDITIONS. EITHER
WAY...TRAVEL WILL CONTINUE TO BE TREACHEROUS IN THE WINTER STORM
WARNING AREA.
NO CHANGES MADE TO TIMING OF COLD AIR ARRIVAL AND MIN WIND CHILLS
AT THIS TIME.
MTF
&&
.PREV DISCUSSION...
338 AM CST
COMPLEX...HIGH IMPACT WINTER WEATHER EVENT UNDERWAY FOR NORTHERN
ILLINOIS AND NORTHWEST INDIANA.
FOR THE SHORT TERM...THE FOCUS IS THE POST-FRONTAL SNOW BAND EXTENDING
FROM CENTRAL MISSOURI...THROUGH ILLINOIS AND INDIANA AND INTO LOWER
MICHIGAN. AS OF 3AM CST...THE COLD FRONT WAS PUSHING INTO NWRN
INDIANA AND EAST-CENTRAL ILLINOIS. THE ONGOING SNOW IS LARGELY
POST-FRONTAL ALONG AN ELEVATED F-GEN BAND. LATEST RADAR IMAGERY
INDICATES NARROW EMBEDDED HEAVIER BANDS WITH AN ENHANCED BAND FROM
GARY TO PONTIAC. SNOWFALL RATES OF 1/2 INCH PER HOUR ARE LIKELY
WITHIN THE HEAVIER BANDS...WITH STEADY LIGHTER SNOW COVERING THE
REMAINDER OF THE CWA. THE POST FRONTAL SNOW SHOULD PERSIST FOR THE
REMAINDER OF THE NIGHT AND INTO THE MORNING HOURS. SOME OF THE HI
RES GUIDANCE IS SUGGESTING A BRIEF LULL TO THE STEADIER SNOW BEFORE
THE WARM ADVECTION SNOW KICKS IN WITH THE SRN STREAM SHORTWAVE
LIFTING UP FROM THE SOUTHWEST. HAVE ACTUALLY MADE LITTLE
SIGNIFICANT CHANGE TO THE GOING FORECAST AND WINTER WEATHER
HEADLINES...BUT STILL HAVE SOME CONCERN ABOUT THE NECESSITY TO
UPGRADE AT LEAST A PORTION OF THE WINTER STORM WARNING TO A BLIZZARD
WARNING FOR LATE THIS AFTERNOON THROUGH TONIGHT. DURING THIS
PERIOD...MUCH OF THE AREA WILL SEE NORTH WINDS GUSTING TO 30-35
MPH. SO...WILL MAINTAIN MENTION OF BLOWING SNOW FOR THE ENTIRE CWA
WITH...ONCE AGAIN...OPEN AREAS WITH EAST-WEST ORIENTED ROADS SEEING
THE GREATEST IMPACT. BY THE TIME THAT THE WARM ADVECTION SNOW GETS
UNDERWAY...THE SERN PORTIONS OF THE CWA...GENERALLY SOUTH AND EAST
OF A LINE FROM GARY TO PONTIAC SHOULD SEE THE HEAVIEST SNOW...WITH
AMOUNTS GRADUALLY TAPERING OFF TO THE NORTH. THE COMBINATION OF
FALLING SNOW AND STRONG WINDS COULD VERY LIKELY PRODUCE BLIZZARD
CONDITIONS...BUT WILL HOLD OFF ON UPGRADING THIS PORTION OF THE AREA
TO A BLIZZARD WARNING FOR NOW...AND MONITOR THE ONSET TIMING OF THE
HEAVIER SNOWFALL RATES WITH THE WARM ADVECTION SNOW. THE HIGH RES
MODEL GUIDANCE STILL WANTS TO DEVELOP A LAKE EFFECT PLUME POINTING
INTO LAKE AND PORTER COUNTIES IN NORTHWESTERN INDIANA LATE THIS
AFTERNOON AND EARLY THIS EVENING...WHICH COULD FURTHER ENHANCE
SNOWFALL RATES AND LIKELY REDUCING VISIBILITY TO NEAR ZERO AT
TIMES. SO...MANY OF THE INGREDIENTS NECESSARY FOR BLIZZARD
CONDITIONS ARE COMING TOGETHER...THE MAIN QUESTIONS BEING TIMING AND
AREA EXTENT STILL UNCERTAIN ENOUGH TO HOLD OFF ON A BLIZZARD WARNING
FOR NOW.
AND THEN THERE IS THE ARCTIC BLAST. TEMPERATURES ARE ALREADY
DROPPING OFF OVER THE NWRN PORTIONS OF THE CWA...WITH ROCKFORD DOWN
TO 18F AS OF 3AM CST. THE TEMPERATURE TREND FOR THE REMAINDER OF
THE DAY WILL BE DOWNWARD...WITH DAILY HIGHS LIKELY ALREADY
OCCURRING. THE TEMPERATURE FORECAST ALSO LOOKS IN LINE WITH
PREVIOUS THINKING WITH TEMPS LIKELY DROPPING BELOW 0F OVER THE
ROCKFORD AREA BY LATE THIS AFTERNOON AND THE COLD AIR CONTINUE TO
OVERSPREAD THE AREA THROUGH SUNDAY NIGHT...WITH THE HAZARDOUSLY COLD
AIR REMAINING OVER THE AREA INTO WEDNESDAY. AGAIN...WITH VERY
CONSISTENT GUIDANCE WITH RESPECT TO THE COLD...STILL EXPECT THAT
LOWS MONDAY AND TUESDAY MORNING WILL DROP TO -15 TO -20F OVER MUCH
OF THE AREA...WITH ONLY THE IMMEDIATE LAKEFRONT SEEING LOWS ABOVE
-15F...BUT STILL WELL BELOW ZERO. HIGHS FOR MONDAY ARE STILL
EXPECTED TO FLIRT WITH ALL TIME RECORD LOW MAX TEMPS. THIS IS
PROBABLY THE ONLY AREA OF THE FORECAST WHICH IS SEEING SOME
FLIP-FLOPPING AND HAVE ADJUSTED MAX TEMPS FOR MONDAY BACK DOWN A FEW
DEGREES SINCE THE VERY STRONG HIGH WILL BE SLIDING OVER THE WESTERN
PLAINS AS THE SRN STREAM LOW IS BOMBING OUT OVER QUEBEC. THIS
SCENARIO WILL SET UP AN UNIMPEDED FETCH OF COLD ARCTIC AIR...SO
STILL FEEL THAT MUCH OF THE LARGER SCALE MODEL GUIDANCE IS ON TARGET
IN KEEPING MAX TEMPS FOR MUCH OF THE CWA AT -15F OR POSSIBLY A TOUCH
LOWER. AGAIN...TEMPS OVER THE URBANIZED CHICAGO METRO AREA AND
IMMEDIATE LAKE FRONT SHOULD BE A TAD MORE MODERATE...BUT EVEN IN
THESE LOCATIONS...TEMPS WILL STRUGGLE TO REACH -10F.
KREIN
TUESDAY THROUGH SATURDAY...
MAIN FORECAST CONCERNS/CHALLENGES IN THIS PERIOD ARE WITH THE
LINGERING COLD AIR MASS...CHANCE FOR SNOW BY MID WEEK...AND THEN A
CONTINUED WARMING TREND EXPECTED INTO THE WEEKEND.
AT THE START OF THE PERIOD...MODEL GUIDANCE IN PRETTY GOOD AGREEMENT
WITH RESPECT TO OVERALL PATTERN ACROSS THE REGION. WITH THE LARGE
AND HIGHLY AMPLIFIED UPPER LEVEL TROUGH SHIFTING TO THE
EAST...LINGERING SURFACE TROUGH OVER THE GREAT LAKES REGION WILL
SLOWLY SHIFT EAST AS HIGH PRESSURE SPREADS OVER THE AREA. ISSUES
DURING THIS TIME FRAME REMAIN WITH THE COLD AIR MASS IN
PLACE...DESPITE SOME SLIGHT MODERATING WITH THIS COLD AIR. EXPECT
WELL BELOW ZERO TEMPS TO SLOWLY RISE THROUGH THE MORNING TIME
FRAME...BUT WITH WIND CHILLS STILL VERY MUCH IN SUPPORT OF THE
CURRENT WIND CHILL WARNING THAT IS IN EFFECT THROUGH MID DAY
TUESDAY. MADE SLIGHT CHANGES TO HIGH TEMPS ON TUESDAY WITH HIGHS
STILL EXPECTED TO HOVER RIGHT AROUND THE ZERO MARK. WITH REGARDS TO
ANY LINGERING LAKE EFFECT SNOWFALL ACROSS PORTIONS OF THE NORTHWEST
INDIANA...CONTINUED BACKING OF THE BOUNDARY LAYER FLOW WILL STEER
ANY LINGERING DEVELOPMENT OVER PORTER COUNTY TO THE EAST/NORTHEAST.
A RETURN TO MORE ZONAL FLOW WILL BE ON THE SHORT SIDE LATE TUESDAY
NIGHT INTO EARLY WEDNESDAY...AS SEVERAL PIECES OF ENERGY TRAVERSE
THE CENTRAL CONUS. AFTER ANOTHER NIGHT OF SUBZERO TEMPS TUESDAY
NIGHT BACKING FLOW IN RESPONSE TO THESE WAVES WILL FURTHER HELP
MODERATE THIS AIR MASS...AS A PERIOD OF WAA IS ANTICIPATED ACROSS
THE REGION. THIS WILL HELP SUPPORT HIGH TEMPS NOT ONLY FINALLY ABOVE
ZERO...BUT IN THE TEENS AND EVEN LOWER 20S ACROSS THE SOUTHERN CWA
WEDNESDAY. A STRONGER AND MORE DEFINED SHORT WAVE TROUGH IS FORECAST
TO MOVE EAST THROUGH THE CENTRAL PLAINS WEDNESDAY NIGHT INTO
THURSDAY...WITH SURFACE TROUGH/FRONTAL ZONE EXPANDING NORTHEAST
TOWARDS THE SOUTHERN CWA. ALTHOUGH SOME WARM ADVECTION PRECIP COULD
DEVELOP ACROSS THE SOUTHERN CWA EARLY IN THE EVENING...WOULD EXPECT
BETTER PRECIP/SNOW AXIS TO WORK ITS WAY UP TOWARDS THE SOUTHERN CWA
DURING THE OVERNIGHT HOURS WEDNESDAY NIGHT. ALTHOUGH SOME SLIGHT
DIFFERENCES IN MODEL GUIDANCE REMAINS WITH REGARDS TO THE STRENGTH
OF THIS SHORT WAVE TROUGH REMAINS...THERE IS A GENERAL CONSENSUS FOR
SNOW TO TO SPREAD INTO PORTIONS OF NORTHEAST/EAST CENTRAL ILLINOIS
AND NORTHWEST INDIANA WITH THE BEST FORCING EXPECTED ACROSS THE
SOUTHERN CWA. THERE IS THE POTENTIAL FOR CONTINUED DEVELOPMENT INTO
PARTS OF THURSDAY...BUT AT THIS TIME EXPECT ANY LINGERING PRECIP TO
SHIFT EAST OF THE CWA.
GUIDANCE BEGINS TO DIVERGE WITH REGARDS TO THE DETAILS BY LATE IN
THE WEEK...BUT THE OVERALL IDEA IS FOR A CONTINUED WARMING TREND. AS
THIS TREND CONTINUES TEMPS COULD REACH THE FREEZING MARK AND/OR
SURPASS IT BY THE END OF THE PERIOD. ALTHOUGH AS THIS
OCCURS...PRECIP TYPE COULD BECOME AN ISSUE AS WELL...AS THERE IS
CHANCES FOR RAIN OR SNOW CURRENTLY IN THE FORECAST WHICH WILL NEED
TO CONTINUE TO BE MONITORED AS WE APPROACH THIS TIME FRAME.
RODRIGUEZ
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* SNOW CONTINUES THROUGH THIS AFTN.
* GUSTY NORTH WINDS BETWEEN 25-29KT THEN WINDS BACK TO THE
NORTHWEST LATE AFTN.
* MODERATE SNOW AT TIMES BTWN 16-20Z WITH VSBYS REDUCED TO 3/4SM.
* IFR CIGS SLOWLY LIFTING TO MVFR CIGS ARND 03Z.
BEACHLER
//DISCUSSION...UPDATED 12Z...
OVERNIGHT BAND OF LIGHT/OCNL MODERATE SNOW HAS WEAKENED AS
EXPECTED EARLY THIS MORNING...WITH A BRIEF LULL ANTICIPATED
UNTIL MID-MORNING. ANOTHER WAVE OF MORE ORGANIZED SNOW WILL THEN
DEVELOP NORTHEAST FROM MISSOURI AND DOWNSTATE IL DURING THE LATE
MORNING AND AFTERNOON HOURS...AS DEEPENING LOW PRESSURE SYSTEM
TRACKS THROUGH THE OHIO VALLEY. PERIOD FROM ROUGHLY 16-20/22Z
LOOKS TO HAVE THE GREATEST THREAT OF MODERATE SNOW WITH LIFR
CONDITIONS INTO ORD/MDW...WITH LOWEST CONDITIONS TO THE SOUTHEAST
AND RFD TO THE NORTHWEST LIKELY REMAINING VFR WITH LITTLE SNOW
AFTER THIS MORNING. SNOW SHOULD TAPER OFF FROM THE WEST LATE THIS
AFTERNOON/EARLY THIS EVENING...WITH IMPROVING VIS/CIG CONDITIONS
THIS EVENING LIKELY TO VFR OVERNIGHT.
NORTH WINDS WILL INCREASE THROUGH THE DAY AS THE LOW DEEPENS TO
OUR SOUTH AND PASSES TO THE EAST. 350-010 DEG GUSTING 20-25 KT
THIS MORNING SHOULD BECOME MORE 330-350 DEG 25-30 KT THIS
AFTERNOON AND CONTINUING TONIGHT. THIS MAY PRODUCE SOME BLOWING
SNOW ISSUES LATE TODAY AND TONIGHT...THOUGH LOW CONFIDENCE IN
IMPACTS ON VISIBILITY FOR TAF PURPOSES. WINDS CONTINUE TO GUST
25-30 KT INTO MONDAY...THOUGH EVENTUALLY BECOMING MORE 280-300 DEG
BY MONDAY MORNING.
RATZER
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM-HIGH CONFIDENCE IN SNOW AND ASSOCIATED CIG/VIS TRENDS
TODAY.
* HIGH CONFIDENCE IN WIND TRENDS.
BEACHLER
//OUTLOOK FOR ORD/MDW FOR 00Z TUESDAY-12Z SUNDAY...UPDATED 12Z...
MONDAY NIGHT...GUSTY WEST WINDS WITH BLOWING SNOW POSSIBLY REDUCING
VSBY...OTHERWISE VFR.
TUESDAY...VFR.
WEDNESDAY AND THURSDAY...CHANCE OF LIGHT SNOW AND IFR.
FRIDAY...SLIGHT CHANCE OF LIGHT SNOW AND MVFR.
SATURDAY...SLIGHT CHANCE OF LIGHT RAIN/SNOW AND MVFR.
RATZER
&&
.MARINE...
236 AM CST
MAIN MARINE CONCERNS ARE A PERIOD OF NORTH-NORTHWEST GALE FORCE
WINDS ACROSS MAINLY THE SOUTHERN HALF OF LAKE MICHIGAN TODAY INTO
EARLY TUESDAY...ALONG WITH HEAVY FREEZING SPRAY POTENTIAL WITH
BITTERLY COLD ARCTIC AIR SPREADING ACROSS THE REGION.
A COLD FRONT WHICH PUSHED SOUTHEAST OF THE LAKE LATE SATURDAY WILL
BE THE FOCUS FOR AN AREA OF LOW PRESSURE WHICH WILL LIFT NORTHEAST
THROUGH THE OHIO VALLEY TODAY...AND ACROSS THE EASTERN LAKES INTO
QUEBEC TONIGHT AND EARLY MONDAY MORNING. THE COMBINATION OF THE
DEEPENING LOW PRESSURE SYSTEM AND STRONG CANADIAN HIGH PRESSURE
SPREADING SOUTHEAST ACROSS THE PLAINS WILL RESULT IN A TIGHTENING
SURFACE PRESSURE GRADIENT ACROSS THE WESTERN LAKES...WHICH WILL
PROVIDE STRONG NORTH-NORTHWEST WINDS ACROSS LAKE MICHIGAN. FORECAST
SOUNDINGS INDICATE GALES IN THE 35-40 KT RANGE ARE HIGHLY LIKELY
ACROSS THE SOUTHERN PORTION OF THE LAKE BY MID/LATE THIS AFTERNOON
AND WILL GRADUALLY BECOME WEST-NORTHWEST THROUGH MONDAY AND MONDAY
NIGHT BEFORE GRADUALLY DIMINISHING BELOW GALE FORCE EARLY TUESDAY
MORNING. A BITTERLY COLD ARCTIC AIR MASS WAS SPREADING SOUTHEAST
ACROSS THE PLAINS AND UPPER MIDWEST...WHICH WILL COMBINE WITH HIGH
WINDS AND WAVES TO PRODUCE HEAVY FREEZING SPRAY ON VESSELS WHICH
VENTURE OUT ON THE LAKE DURING THE EARLY PORTION OF THIS WEEK. THUS
GALE AND HEAVY FREEZING SPRAY WARNINGS ARE IN EFFECT THROUGH EARLY
TUESDAY. HIGH PRESSURE RIDGING WILL EVENTUALLY PUSH INTO THE WESTERN
GREAT LAKES REGION MID-WEEK...ALLOWING WINDS TO DIMINISH MORE
QUICKLY LATE TUESDAY NIGHT THROUGH THURSDAY. MODERATING TEMPERATURES
ALONG WITH LIGHTER WINDS SHOULD EASE FREEZING SPRAY CONCERNS BY
MID-WEEK AS WELL.
FOR THE ILLINOIS AND INDIANA NEARSHORE WATERS...GALE AND FREEZING
SPRAY WARNINGS INCLUDE INDIANA WATERS WITH NORTHWEST FETCH OFF OPEN
WATERS. WINDS ALONG THE ILLINOIS SHORE LOOK TO BE MARGINAL WITH
RESPECT TO SOLID GALES...WITH GUSTS NEAR BUT PERHAPS INFREQUENTLY
TOPPING 34 KT. WILL GO AHEAD AND UPGRADE THE CURRENT GALE WATCH TO
A WARNING FOR THE IL SHORE...BUT ONLY THROUGH 18Z MONDAY BY WHICH
TIME FLOW BACKS MORE WESTERLY AND SPEEDS DECREASE A LITTLE THROUGH
THE MIXED LAYER.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ006-ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-
ILZ019-ILZ020-ILZ021-ILZ022 UNTIL 6 PM SUNDAY.
WIND CHILL WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022...6
PM SUNDAY TO NOON TUESDAY.
WINTER STORM WARNING...ILZ023-ILZ032-ILZ033-ILZ039 UNTIL
MIDNIGHT MONDAY.
WIND CHILL WARNING...ILZ023-ILZ032-ILZ033-ILZ039...MIDNIGHT
MONDAY TO NOON TUESDAY.
IN...WIND CHILL WARNING...INZ001-INZ002-INZ010-INZ011-
INZ019...MIDNIGHT MONDAY TO NOON TUESDAY.
WINTER STORM WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
MIDNIGHT MONDAY.
LM...GALE WARNING...LMZ080-LMZ669-LMZ671-LMZ673-LMZ675-LMZ743-LMZ744-
LMZ745-LMZ777-LMZ779-LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...3
PM SUNDAY TO 4 AM TUESDAY.
HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ261-LMZ362-LMZ364-
LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878...3 PM SUNDAY TO 4 AM TUESDAY.
GALE WARNING...LMZ740-LMZ741-LMZ742...3 PM SUNDAY TO NOON MONDAY.
SMALL CRAFT ADVISORY...NEARSHORE WATERS
UNTIL 3 PM SUNDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1059 AM CST Sun Jan 5 2014
.DISCUSSION...
ISSUED 1058 AM CST Sun Jan 5 2014
Main complication with the event thus far has been the mixed
precipitation across the southeast CWA. Temps still hanging in the
lower 30s across much of east central and southeast Illinois.
Enhanced reflectivities on radar showing the mixed precip
continuing from around Carbondale northeast through Lawrenceville,
having switched over to snow elsewhere south of I-70. Main surface
low still back over the western tip of Kentucky and will track
northeast along the Ohio River through midday. RAP sounding from
Lawrenceville shows the mixture may continue into early afternoon.
Have toned down snow totals across the extreme southeast due to
this mixture.
With the warmer temperatures in the east, the snow has been wetter
than first expected. While winds may be strong enough to reach
blizzard criteria this afternoon, the snow may not blow around as
severely. Will keep the current headlines as-is and continue to
monitor.
Geelhart
&&
.AVIATION...
ISSUED 1058 AM CST Sun Jan 5 2014
LIFR to VLIFR conditions will continue through the afternoon. Some
improvement being noted northwest of KPIA along the back edge of
the snow shield, but areas of blowing snow will result in MVFR
visibilities at times as the snow ends. Think that KCMI/KBMI/KDEC
will see visibilities of 1/2SM or less for several more hours, as
a surface low moves up the lower Ohio River and enhances the bands
of snow to its northwest. Northerly winds will slowly trend to the
northwest. Gusts of 25-35 knots will persist through the early
evening hours. Increases in the ceilings will take place early in
the evening as skies become clear.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 344 AM CST Sun Jan 5 2014
Ongoing winter storm in progress with the first round of precip
along a frontogenetic band across the NW. Starting to fill in a
bit to the east of Interstate 55...and struggling with precip type
as cold air is slow moving to the southeast. Models slowing down
appreciably with the forward progression of the developing sfc
low through midday. Some minor adjustments to the snowfall and
adding in a bit of a mix for the early morning in the extreme SE
where cold air is slower to approach. Plenty of moisture still
there to work with. Forecast into the extended has another system
for midweek with some more snow in store...but that is where
extended models diverge with very different ideas into Day 7.
Adjustments to the short term forecast...ALLBLEND nearly left
alone for the extended.
SHORT TERM...Today through tomorrow...
Snow continuing to spread as the cold air filters into the SE and
the changeover to snow dominates. S of Interstate 55 will see a
bit of wintry mix this morning until mid morning. This will change
the amount of snow for the SE...but only for the morning...as the
bulk of the storm will be arriving for mid morning through the end
of the day. Delay in the progression of the sfc low...with the
RUC/RAP slowing even more than the HRRR...moving through the Ohio River
Valley this afternoon. Back edge of the heaviest precip a bit of a
problem, varying a bit from model to model with introduction of
drier air on the NWrn edge...but 3 to 5 inches already NW of the
Illinois River Valley resulting in an upgrade to a Winter Storm
Warning. Snow totals overall not changing much with regards to
entire event. Brutally cold air moving in on the back side of this
system. Cold air already settling into southern Canada and will be
sinking in behind the exiting storm. In combination with winds in
the 25 to 30 mph range...wind chills will drop to a very dangerous
-30 to -40 from tonight...through Tuesday morning. Wind chill
warning remains. Those same winds will cause problems with blowing
and drifting snow well after the end of the snowfall tonight.
LONG TERM...Tuesday through Saturday...
Tues and Tues night highs and lows both in the single digits as
the region begins a slow warm up. SWrly flow aloft as another trof
digs into the desert SW and southerly winds at sfc usher warmer
temps in for Wednesday with highs in the 20s. Another system
ejecting out of the SW for Wed night/Thursday. Best chances for
precip to the SE, similar to current storm...but far too early for
details. Climo has major impact to the highs and lows beyond that
point and the ECMWF and the GFS diverge majorly. Very low
confidence in the extended.
HJS
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING until Midnight CST tonight FOR ILZ027>031-
036>038-040>057-061>063-066>068-071>073.
WIND CHILL WARNING from Midnight tonight to Noon CST Tuesday FOR
ILZ027>031-036>038-040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
308 PM EST SUN JAN 5 2014
.UPDATE...
LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 319 AM EST SUN JAN 5 2014
A STORM SYSTEM IS EXPECTED TO BRING A SIGNIFICANT WINTER STORM TO
THE AREA TODAY AND TONIGHT...FOLLOWED BY VERY COLD AIR EARLY NEXT
WEEK IN THE WAKE OF THIS STORM. ADDITIONAL FRONTAL SYSTEM MAY
AFFECT THE AREA AROUND THE MIDDLE OF THE WEEK AND OVER NEXT WEEKEND.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 943 AM EST SUN JAN 5 2014
CURRENT FORECAST IS ON TRACK. PRECIPITATION HAS OVERSPREAD THE
AREA...WITH MODERATE SNOW ACROSS NORTHWEST 2/3 OF CENTRAL INDIANA.
ACROSS THE REMAINDER OF THE AREA...A MIX OF RAIN AND SNOW OR JUST
RAIN CONTINUES.
DUAL-POL RADAR SHOWING MIXED PRECIPITATION IS MOVING NORTH AS
EXPECTED. RAP TRIES TO BRING MIX AS FAR NORTH AS INDIANAPOLIS BUT
LATEST NAM12 KEEPS IT JUST SOUTHEAST OF INDY. BASED ON EXPECTED PATH
OF LOW AND CURRENT TRENDS... LEFT FORECAST AS IS WITH MIX COMING AS
FAR NORTH AS SHELBYVILLE/RUSHVILLE. WILL MONITOR CLOSELY.
PREVIOUS DISCUSSION FOLLOWS...
THINGS SEEM TO BE EVOLVING SLOWER THAN EXPECTED...BUT MODEL DATA
SUGGEST THE MAIN THEME REMAINS THE SAME. MODELS IN RATHER GOOD
AGREEMENT NOW WITH RESPECT TO THE DEVELOPING SURFACE LOW...TRACKING
IT NEAR OF JUST SOUTH OF THE OHIO RIVER THIS AFTERNOON AND EVENING.
NOT TOO MUCH GOING ON AT THIS TIME...HOWEVER THE MAIN LIFT FROM THIS
STORM IS EXPECTED TO BEGIN MOVING INTO THE AREA AFTER SUNRISE...SO
EXPECTING PRECIPITATION TO INCREASE IN INTENSITY/COVERAGE BY THAT
TIME. THE STRONGEST LIFT/HEAVIEST PRECIPITATION LOOKS TO PASS OVER
THE AREA FROM ABOUT MIDDAY THROUGH THE AFTERNOON HOURS. SOME
LINGERING WARM AIR OVER THE SOUTH/SOUTHEAST ZONES SHOULD RESULT IN
MORE OF A MIX INTO THE AFTERNOON HOURS BEFORE THE ATMOSPHERIC COLUMN
COOLS. ELSEWHERE...PRECIPITATION TYPE EXPECTED TO REMAIN SNOW.
MODEL DATA SUGGEST DEFORMATION ZONE WILL STILL BE OVER THE WESTERN
ZONES BY EVENING...SO THINK LIGHTER SNOWFALL WILL CONTINUE OVER THE
AREA THROUGH ABOUT MIDNIGHT BEFORE TAPERING OFF TO SNOW SHOWERS AND
FLURRIES. WINDS EXPECTED TO PICK UP TOWARDS/AFTER SUNSET TONIGHT
WITH GUST TO AROUND 40 MPH POSSIBLE. THIS WILL CAUSE CONSIDERABLE
BLOWING AND DRIFTING SNOW. MAY FLIRT WITH BLIZZARD CRITERIA FOR A
PERIOD THIS EVENING...BUT WITH THE HEAVIER SNOW DIMINISHING BY THAT
TIME...MAY BE HARD TO REACH VISIBILITY CRITERIA. THIS WILL BE
SOMETHING THAT WILL NEED TO BE WATCHED.
GIVEN A SURFACE LOW TRACK ALONG THE OHIO RIVER AND LOCATION OF
DEFORMATION ZONE...STILL APPEARS THE HIGHEST STORM TOTALS WILL BE
LOCATED OVER THE NORTHWEST HALF OF THE FORECAST AREA...WITH LESSER
TOTALS FARTHER SOUTHEAST DUE TO MIXING ISSUES AND BEING LOCATED
FARTHER AWAY FROM THE DEFORMATION ZONE. MODEL GUIDANCE SUGGESTS
POTENTIAL STORM TOTALS FROM AROUND 5 INCHES OVER THE FAR SOUTHEAST
TO ABOUT 10 TO 14 INCHES OVER THE NORTHWEST HALF OF THE AREA.
WILL HOLD ONTO THE WINTER STORM WARNING AS IS FOR NOW...ALTHOUGH IT
DOES APPEAR CONDITIONS WON/T BEGIN TO DETERIORATE UNTIL AFTER
SUNRISE. DUE TO THE SLOWER EVOLUTION OF THE STORM...MAY NEED TO
EXTEND THE WARNING LATER IN TIME AS WELL.
WILL ALSO BE ISSUING A WIND CHILL WARNING STARTING LATE TONIGHT AND
LASTING THROUGH TUESDAY WITH WIND CHILLS EXPECTED TO EXCEED WARNING
CRITERIA THROUGHOUT THOSE TIMES.
EXPECTING TEMPERATURES TO HOLD ABOUT STEADY UNTIL PRECIPITATION
BEGINS...THEN SLOWLY FALL OFF DURING THE AFTERNOON. THE SLOWER
EVOLUTION OF THE STORM SUGGESTS TEMPERATURES PROBABLY WON/T REALLY
START FALLING ON UNTIL AFTER SUNSET. BASED ON LOW LEVEL
THICKNESSES...THE GFS MOS LOWS TONIGHT LOOK TOO COLD. WILL BUMP THEM
UP ABOUT 3-5 DEGREES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ISSUED AT 319 AM EST SUN JAN 5 2014
DEEP COLD UPPER LOW OVER THE GREAT LAKES ON MONDAY EXPECTED TO
REMAIN PROGRESSIVE...SO VERY COLD TEMPERATURES SHOULD GRADUALLY
MODERATE DURING THE PERIOD AS HEIGHTS SLOWLY RISE. OTHER THAN SOME
FLURRIES ON MONDAY DUE TO VERY STEEP LOW LEVEL LAPSE RATES...THE
SHORT TERM SHOULD BE DRY AS HIGH PRESSURE MOVES THROUGH.
LOW LEVEL THICKNESS PROGS SUGGEST THE GFS MOS HIGHS AND LOWS MONDAY
AND MONDAY NIGHT LOOK A LITTLE TOO COLD. WILL RAISE THE GUIDANCE
SEVERAL DEGREES IN THOSE PERIODS. HIGHS BY TUESDAY LOOK BETTER...BUT
MAY STILL BE A LITTLE COLD.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 308 PM EST SUN JAN 5 2014
A ZONAL UPPER FLOW PREDOMINATES IN THE LONG TERM AND TEMPERATURES
WILL MODERATE THROUGH THE PERIOD AND WITH ABOVE NORMAL TEMPERATURES
BY THE WEEKEND. THERE ARE A COUPLE OF WEAK SYSTEM WHICH WILL AFFECT
US WITH ONE MOVING THROUGH AROUND WEDNESDAY NIGHT/THURSDAY AND
ANOTHER EARLY SATURDAY FOLLOWED BY ANOTHER TOWARDS THE END OF DAY 7.
THE WEDNESDAY NIGHT/THURSDAY SYSTEM MAY GENERATE LIGHT TO MODERATE
SNOW ACCUMULATIONS...BUT BY THE WEEKEND IT WILL BE WARMUP FOR MOST
OF THE PRECIPITATION TO LIQUID. OVERALL THE ALLBLEND ON
TEMPERATURES SEEM REASONABLE AND ONLY MINOR CHANGES MADE. HIGHS
WILL BE IN THE 20S WEDNESDAY WARMING TO THE UPPER 30S TO LOWER 40S
OVER THE WEEKEND.
&&
.AVIATION /DISCUSSION FOR THE 051800Z TAF ISSUANCE/...
ISSUED AT 1208 PM EDT SUN JAN 5 2014
LIFR CEILINGS AND SNOW WILL BE THE RULE THIS AFTERNOON INTO THIS
EVENING WITH INCREASING WINDS BY EVENING. THIS WILL BE FOLLOWED BY A
GRADUAL IMPROVEMENT LATE TONIGHT.
LOW PRESSURE OVER WESTERN KENTUCKY WILL TRACK NORTHEAST ACROSS THE
OHIO VALLEY THIS AFTERNOON AND INTO SOUTHERN OHIO BY THIS EVENING
AND TO THE EASTERN GREAT LAKES BY 06Z. THIS SYSTEM WILL GENERATE
SNOW OVER MUCH OF THE AREA. HOWEVER KBMG MAY BE WARM ENOUGH TO SEE A
WINTRY MIX FOR THE FIRST FEW HOURS BEFORE CHANGING TO SNOW.
AS THE SURFACE LOW PULLS TO OUR EAST...A STRONG PRESSURE GRADIENT
WILL SET UP ACROSS THE AREA AND SURFACE WINDS WILL INCREASE TO 23
KNOTS WITH GUSTS TO 30 TO 35 KNOTS THIS EVENING CAUSING CONSIDERABLE
BLOWING AND DRIFTING OF SNOW.
AS SNOW DIMINISHES LATER THIS EVENING AS LOW PRESSURE MOVES TO THE
NORTHEAST CEILINGS AND VISIBILITIES WILL BEGIN A VERY SLOW
IMPROVEMENT REACHING A COUPLE OF MILES VISIBILITY AND MVFR CEILINGS
AFTER MIDNIGHT.
ON MONDAY...EXPECT ONLY SCATTERED FLURRIES AS DRIER AIR MOVES
IN...BUT WITH BLOWING SNOW MAY KEEP VISIBILITIES MVFR. WINDS MONDAY
WILL BE WEST 15 TO 25 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 1 AM EST MONDAY FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
WIND CHILL WARNING FROM 1 AM MONDAY TO 7 PM EST TUESDAY FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
SYNOPSIS...JAS
NEAR TERM...JAS/50
SHORT TERM...JAS
LONG TERM....JH
AVIATION...JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1208 PM EST SUN JAN 5 2014
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 319 AM EST SUN JAN 5 2014
A STORM SYSTEM IS EXPECTED TO BRING A SIGNIFICANT WINTER STORM TO
THE AREA TODAY AND TONIGHT...FOLLOWED BY VERY COLD AIR EARLY NEXT
WEEK IN THE WAKE OF THIS STORM. ADDITIONAL FRONTAL SYSTEM MAY
AFFECT THE AREA AROUND THE MIDDLE OF THE WEEK AND OVER NEXT WEEKEND.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 943 AM EST SUN JAN 5 2014
CURRENT FORECAST IS ON TRACK. PRECIPITATION HAS OVERSPREAD THE
AREA...WITH MODERATE SNOW ACROSS NORTHWEST 2/3 OF CENTRAL INDIANA.
ACROSS THE REMAINDER OF THE AREA...A MIX OF RAIN AND SNOW OR JUST
RAIN CONTINUES.
DUAL-POL RADAR SHOWING MIXED PRECIPITATION IS MOVING NORTH AS
EXPECTED. RAP TRIES TO BRING MIX AS FAR NORTH AS INDIANAPOLIS BUT
LATEST NAM12 KEEPS IT JUST SOUTHEAST OF INDY. BASED ON EXPECTED PATH
OF LOW AND CURRENT TRENDS... LEFT FORECAST AS IS WITH MIX COMING AS
FAR NORTH AS SHELBYVILLE/RUSHVILLE. WILL MONITOR CLOSELY.
PREVIOUS DISCUSSION FOLLOWS...
THINGS SEEM TO BE EVOLVING SLOWER THAN EXPECTED...BUT MODEL DATA
SUGGEST THE MAIN THEME REMAINS THE SAME. MODELS IN RATHER GOOD
AGREEMENT NOW WITH RESPECT TO THE DEVELOPING SURFACE LOW...TRACKING
IT NEAR OF JUST SOUTH OF THE OHIO RIVER THIS AFTERNOON AND EVENING.
NOT TOO MUCH GOING ON AT THIS TIME...HOWEVER THE MAIN LIFT FROM THIS
STORM IS EXPECTED TO BEGIN MOVING INTO THE AREA AFTER SUNRISE...SO
EXPECTING PRECIPITATION TO INCREASE IN INTENSITY/COVERAGE BY THAT
TIME. THE STRONGEST LIFT/HEAVIEST PRECIPITATION LOOKS TO PASS OVER
THE AREA FROM ABOUT MIDDAY THROUGH THE AFTERNOON HOURS. SOME
LINGERING WARM AIR OVER THE SOUTH/SOUTHEAST ZONES SHOULD RESULT IN
MORE OF A MIX INTO THE AFTERNOON HOURS BEFORE THE ATMOSPHERIC COLUMN
COOLS. ELSEWHERE...PRECIPITATION TYPE EXPECTED TO REMAIN SNOW.
MODEL DATA SUGGEST DEFORMATION ZONE WILL STILL BE OVER THE WESTERN
ZONES BY EVENING...SO THINK LIGHTER SNOWFALL WILL CONTINUE OVER THE
AREA THROUGH ABOUT MIDNIGHT BEFORE TAPERING OFF TO SNOW SHOWERS AND
FLURRIES. WINDS EXPECTED TO PICK UP TOWARDS/AFTER SUNSET TONIGHT
WITH GUST TO AROUND 40 MPH POSSIBLE. THIS WILL CAUSE CONSIDERABLE
BLOWING AND DRIFTING SNOW. MAY FLIRT WITH BLIZZARD CRITERIA FOR A
PERIOD THIS EVENING...BUT WITH THE HEAVIER SNOW DIMINISHING BY THAT
TIME...MAY BE HARD TO REACH VISIBILITY CRITERIA. THIS WILL BE
SOMETHING THAT WILL NEED TO BE WATCHED.
GIVEN A SURFACE LOW TRACK ALONG THE OHIO RIVER AND LOCATION OF
DEFORMATION ZONE...STILL APPEARS THE HIGHEST STORM TOTALS WILL BE
LOCATED OVER THE NORTHWEST HALF OF THE FORECAST AREA...WITH LESSER
TOTALS FARTHER SOUTHEAST DUE TO MIXING ISSUES AND BEING LOCATED
FARTHER AWAY FROM THE DEFORMATION ZONE. MODEL GUIDANCE SUGGESTS
POTENTIAL STORM TOTALS FROM AROUND 5 INCHES OVER THE FAR SOUTHEAST
TO ABOUT 10 TO 14 INCHES OVER THE NORTHWEST HALF OF THE AREA.
WILL HOLD ONTO THE WINTER STORM WARNING AS IS FOR NOW...ALTHOUGH IT
DOES APPEAR CONDITIONS WON/T BEGIN TO DETERIORATE UNTIL AFTER
SUNRISE. DUE TO THE SLOWER EVOLUTION OF THE STORM...MAY NEED TO
EXTEND THE WARNING LATER IN TIME AS WELL.
WILL ALSO BE ISSUING A WIND CHILL WARNING STARTING LATE TONIGHT AND
LASTING THROUGH TUESDAY WITH WIND CHILLS EXPECTED TO EXCEED WARNING
CRITERIA THROUGHOUT THOSE TIMES.
EXPECTING TEMPERATURES TO HOLD ABOUT STEADY UNTIL PRECIPITATION
BEGINS...THEN SLOWLY FALL OFF DURING THE AFTERNOON. THE SLOWER
EVOLUTION OF THE STORM SUGGESTS TEMPERATURES PROBABLY WON/T REALLY
START FALLING ON UNTIL AFTER SUNSET. BASED ON LOW LEVEL
THICKNESSES...THE GFS MOS LOWS TONIGHT LOOK TOO COLD. WILL BUMP THEM
UP ABOUT 3-5 DEGREES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ISSUED AT 319 AM EST SUN JAN 5 2014
DEEP COLD UPPER LOW OVER THE GREAT LAKES ON MONDAY EXPECTED TO
REMAIN PROGRESSIVE...SO VERY COLD TEMPERATURES SHOULD GRADUALLY
MODERATE DURING THE PERIOD AS HEIGHTS SLOWLY RISE. OTHER THAN SOME
FLURRIES ON MONDAY DUE TO VERY STEEP LOW LEVEL LAPSE RATES...THE
SHORT TERM SHOULD BE DRY AS HIGH PRESSURE MOVES THROUGH.
LOW LEVEL THICKNESS PROGS SUGGEST THE GFS MOS HIGHS AND LOWS MONDAY
AND MONDAY NIGHT LOOK A LITTLE TOO COLD. WILL RAISE THE GUIDANCE
SEVERAL DEGREES IN THOSE PERIODS. HIGHS BY TUESDAY LOOK BETTER...BUT
MAY STILL BE A LITTLE COLD.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 334 AM EST SUN JAN 5 2014
ACTIVE PATTERN CONTINUES THROUGH THE PERIOD...WITH YET ANOTHER
CHANCE FOR ACCUMULATING SNOW BEGINNING LATE WEDNESDAY AS AN UPPER
LEVEL WAVE DROPS SOUTHEAST OUT OF THE NORTHERN PLAINS AND
INTERACTING WITH A SURFACE TROUGH AND GULF MOISTURE LIFTING NORTH
INTO THE REGION. THIS FEATURE WILL LIFT SLOWLY THROUGH THE OHIO
VALLEY WITH SNOW LIKELY TO FALL WEDNESDAY NIGHT AND THURSDAY...
POSSIBLY CONTINUING INTO THURSDAY NIGHT. STILL A BIT PREMATURE TO
CONSIDER SPECIFIC ACCUMS AT THIS POINT BUT IT DOES APPEAR THE
POTENTIAL WILL EXIST FOR A FEW INCHES OF SNOW AT THE VERY LEAST.
UPPER LEVEL FLOW WILL TRANSITION FROM QUASI-ZONAL TO A MOIST
SOUTHWEST FLOW BY FRIDAY AS AN UPPER LEVEL LOW DEVELOPS OVER
NORTHERN MEXICO. ANOTHER STORM SYSTEM SET TO DEVELOP AND EXPAND
TOWARDS THE OHIO/TENNESSEE VALLEYS OVER THE WEEKEND AS THE UPPER LOW
EJECTS INTO TEXAS BY SUNDAY. APPEARS ENOUGH WARM AIR WITHIN THE
LOWER LEVELS WILL ADVECT NORTH TO PRESENT A WINTRY PRECIP MIX OR
EVEN A PERIOD WITH RAIN AS THE PREDOMINANT PRECIP TYPE. HIGHS SHOULD
WARM BACK INTO THE 30S TO LOWER 40S BY SATURDAY AND SUNDAY...LIKELY
TO BE A WELCOME CHANGE FROM THE BITTERLY COLD TEMPS TO COME OVER THE
NEXT FEW DAYS.
&&
.AVIATION /DISCUSSION FOR THE 051800Z TAF ISSUANCE/...
ISSUED AT 1208 PM EDT SUN JAN 5 2014
LIFR CEILINGS AND SNOW WILL BE THE RULE THIS AFTERNOON INTO THIS
EVENING WITH INCREASING WINDS BY EVENING. THIS WILL BE FOLLOWED BY A
GRADUAL IMPROVEMENT LATE TONIGHT.
LOW PRESSURE OVER WESTERN KENTUCKY WILL TRACK NORTHEAST ACROSS THE
OHIO VALLEY THIS AFTERNOON AND INTO SOUTHERN OHIO BY THIS EVENING
AND TO THE EASTERN GREAT LAKES BY 06Z. THIS SYSTEM WILL GENERATE
SNOW OVER MUCH OF THE AREA. HOWEVER KBMG MAY BE WARM ENOUGH TO SEE A
WINTRY MIX FOR THE FIRST FEW HOURS BEFORE CHANGING TO SNOW.
AS THE SURFACE LOW PULLS TO OUR EAST...A STRONG PRESSURE GRADIENT
WILL SET UP ACROSS THE AREA AND SURFACE WINDS WILL INCREASE TO 23
KNOTS WITH GUSTS TO 30 TO 35 KNOTS THIS EVENING CAUSING CONSIDERABLE
BLOWING AND DRIFTING OF SNOW.
AS SNOW DIMINISHES LATER THIS EVENING AS LOW PRESSURE MOVES TO THE
NORTHEAST CEILINGS AND VISIBILITIES WILL BEGIN A VERY SLOW
IMPROVEMENT REACHING A COUPLE OF MILES VISIBILITY AND MVFR CEILINGS
AFTER MIDNIGHT.
ON MONDAY...EXPECT ONLY SCATTERED FLURRIES AS DRIER AIR MOVES
IN...BUT WITH BLOWING SNOW MAY KEEP VISIBILITIES MVFR. WINDS MONDAY
WILL BE WEST 15 TO 25 KNOTS.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 1 AM EST MONDAY FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
WIND CHILL WARNING FROM 1 AM MONDAY TO 7 PM EST TUESDAY FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/50
SHORT TERM...JAS
LONG TERM....RYAN
AVIATION...JH
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
943 AM EST SUN JAN 5 2014
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 319 AM EST SUN JAN 5 2014
A STORM SYSTEM IS EXPECTED TO BRING A SIGNIFICANT WINTER STORM TO
THE AREA TODAY AND TONIGHT...FOLLOWED BY VERY COLD AIR EARLY NEXT
WEEK IN THE WAKE OF THIS STORM. ADDITIONAL FRONTAL SYSTEM MAY
AFFECT THE AREA AROUND THE MIDDLE OF THE WEEK AND OVER NEXT WEEKEND.
&&
.NEAR TERM /REST OF TODAY AND TONIGHT/...
ISSUED AT 943 AM EST SUN JAN 5 2014
CURRENT FORECAST IS ON TRACK. PRECIPITATION HAS OVERSPREAD THE
AREA...WITH MODERATE SNOW ACROSS NORTHWEST 2/3 OF CENTRAL INDIANA.
ACROSS THE REMAINDER OF THE AREA...A MIX OF RAIN AND SNOW OR JUST
RAIN CONTINUES.
DUAL-POL RADAR SHOWING MIXED PRECIPITATION IS MOVING NORTH AS
EXPECTED. RAP TRIES TO BRING MIX AS FAR NORTH AS INDIANAPOLIS BUT
LATEST NAM12 KEEPS IT JUST SOUTHEAST OF INDY. BASED ON EXPECTED PATH
OF LOW AND CURRENT TRENDS... LEFT FORECAST AS IS WITH MIX COMING AS
FAR NORTH AS SHELBYVILLE/RUSHVILLE. WILL MONITOR CLOSELY.
PREVIOUS DISCUSSION FOLLOWS...
THINGS SEEM TO BE EVOLVING SLOWER THAN EXPECTED...BUT MODEL DATA
SUGGEST THE MAIN THEME REMAINS THE SAME. MODELS IN RATHER GOOD
AGREEMENT NOW WITH RESPECT TO THE DEVELOPING SURFACE LOW...TRACKING
IT NEAR OF JUST SOUTH OF THE OHIO RIVER THIS AFTERNOON AND EVENING.
NOT TOO MUCH GOING ON AT THIS TIME...HOWEVER THE MAIN LIFT FROM THIS
STORM IS EXPECTED TO BEGIN MOVING INTO THE AREA AFTER SUNRISE...SO
EXPECTING PRECIPITATION TO INCREASE IN INTENSITY/COVERAGE BY THAT
TIME. THE STRONGEST LIFT/HEAVIEST PRECIPITATION LOOKS TO PASS OVER
THE AREA FROM ABOUT MIDDAY THROUGH THE AFTERNOON HOURS. SOME
LINGERING WARM AIR OVER THE SOUTH/SOUTHEAST ZONES SHOULD RESULT IN
MORE OF A MIX INTO THE AFTERNOON HOURS BEFORE THE ATMOSPHERIC COLUMN
COOLS. ELSEWHERE...PRECIPITATION TYPE EXPECTED TO REMAIN SNOW.
MODEL DATA SUGGEST DEFORMATION ZONE WILL STILL BE OVER THE WESTERN
ZONES BY EVENING...SO THINK LIGHTER SNOWFALL WILL CONTINUE OVER THE
AREA THROUGH ABOUT MIDNIGHT BEFORE TAPERING OFF TO SNOW SHOWERS AND
FLURRIES. WINDS EXPECTED TO PICK UP TOWARDS/AFTER SUNSET TONIGHT
WITH GUST TO AROUND 40 MPH POSSIBLE. THIS WILL CAUSE CONSIDERABLE
BLOWING AND DRIFTING SNOW. MAY FLIRT WITH BLIZZARD CRITERIA FOR A
PERIOD THIS EVENING...BUT WITH THE HEAVIER SNOW DIMINISHING BY THAT
TIME...MAY BE HARD TO REACH VISIBILITY CRITERIA. THIS WILL BE
SOMETHING THAT WILL NEED TO BE WATCHED.
GIVEN A SURFACE LOW TRACK ALONG THE OHIO RIVER AND LOCATION OF
DEFORMATION ZONE...STILL APPEARS THE HIGHEST STORM TOTALS WILL BE
LOCATED OVER THE NORTHWEST HALF OF THE FORECAST AREA...WITH LESSER
TOTALS FARTHER SOUTHEAST DUE TO MIXING ISSUES AND BEING LOCATED
FARTHER AWAY FROM THE DEFORMATION ZONE. MODEL GUIDANCE SUGGESTS
POTENTIAL STORM TOTALS FROM AROUND 5 INCHES OVER THE FAR SOUTHEAST
TO ABOUT 10 TO 14 INCHES OVER THE NORTHWEST HALF OF THE AREA.
WILL HOLD ONTO THE WINTER STORM WARNING AS IS FOR NOW...ALTHOUGH IT
DOES APPEAR CONDITIONS WON/T BEGIN TO DETERIORATE UNTIL AFTER
SUNRISE. DUE TO THE SLOWER EVOLUTION OF THE STORM...MAY NEED TO
EXTEND THE WARNING LATER IN TIME AS WELL.
WILL ALSO BE ISSUING A WIND CHILL WARNING STARTING LATE TONIGHT AND
LASTING THROUGH TUESDAY WITH WIND CHILLS EXPECTED TO EXCEED WARNING
CRITERIA THROUGHOUT THOSE TIMES.
EXPECTING TEMPERATURES TO HOLD ABOUT STEADY UNTIL PRECIPITATION
BEGINS...THEN SLOWLY FALL OFF DURING THE AFTERNOON. THE SLOWER
EVOLUTION OF THE STORM SUGGESTS TEMPERATURES PROBABLY WON/T REALLY
START FALLING ON UNTIL AFTER SUNSET. BASED ON LOW LEVEL
THICKNESSES...THE GFS MOS LOWS TONIGHT LOOK TOO COLD. WILL BUMP THEM
UP ABOUT 3-5 DEGREES.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
ISSUED AT 319 AM EST SUN JAN 5 2014
DEEP COLD UPPER LOW OVER THE GREAT LAKES ON MONDAY EXPECTED TO
REMAIN PROGRESSIVE...SO VERY COLD TEMPERATURES SHOULD GRADUALLY
MODERATE DURING THE PERIOD AS HEIGHTS SLOWLY RISE. OTHER THAN SOME
FLURRIES ON MONDAY DUE TO VERY STEEP LOW LEVEL LAPSE RATES...THE
SHORT TERM SHOULD BE DRY AS HIGH PRESSURE MOVES THROUGH.
LOW LEVEL THICKNESS PROGS SUGGEST THE GFS MOS HIGHS AND LOWS MONDAY
AND MONDAY NIGHT LOOK A LITTLE TOO COLD. WILL RAISE THE GUIDANCE
SEVERAL DEGREES IN THOSE PERIODS. HIGHS BY TUESDAY LOOK BETTER...BUT
MAY STILL BE A LITTLE COLD.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
ISSUED AT 334 AM EST SUN JAN 5 2014
ACTIVE PATTERN CONTINUES THROUGH THE PERIOD...WITH YET ANOTHER
CHANCE FOR ACCUMULATING SNOW BEGINNING LATE WEDNESDAY AS AN UPPER
LEVEL WAVE DROPS SOUTHEAST OUT OF THE NORTHERN PLAINS AND
INTERACTING WITH A SURFACE TROUGH AND GULF MOISTURE LIFTING NORTH
INTO THE REGION. THIS FEATURE WILL LIFT SLOWLY THROUGH THE OHIO
VALLEY WITH SNOW LIKELY TO FALL WEDNESDAY NIGHT AND THURSDAY...
POSSIBLY CONTINUING INTO THURSDAY NIGHT. STILL A BIT PREMATURE TO
CONSIDER SPECIFIC ACCUMS AT THIS POINT BUT IT DOES APPEAR THE
POTENTIAL WILL EXIST FOR A FEW INCHES OF SNOW AT THE VERY LEAST.
UPPER LEVEL FLOW WILL TRANSITION FROM QUASI-ZONAL TO A MOIST
SOUTHWEST FLOW BY FRIDAY AS AN UPPER LEVEL LOW DEVELOPS OVER
NORTHERN MEXICO. ANOTHER STORM SYSTEM SET TO DEVELOP AND EXPAND
TOWARDS THE OHIO/TENNESSEE VALLEYS OVER THE WEEKEND AS THE UPPER LOW
EJECTS INTO TEXAS BY SUNDAY. APPEARS ENOUGH WARM AIR WITHIN THE
LOWER LEVELS WILL ADVECT NORTH TO PRESENT A WINTRY PRECIP MIX OR
EVEN A PERIOD WITH RAIN AS THE PREDOMINANT PRECIP TYPE. HIGHS SHOULD
WARM BACK INTO THE 30S TO LOWER 40S BY SATURDAY AND SUNDAY...LIKELY
TO BE A WELCOME CHANGE FROM THE BITTERLY COLD TEMPS TO COME OVER THE
NEXT FEW DAYS.
&&
.AVIATION /DISCUSSION FOR THE 051500Z KIND TAF UPDATE/...
ISSUED AT 930 AM EDT SUN JAN 5 2014
MINOR TWEAKS MADE TO KIND TAF TO BETTER MATCH CURRENT CONDITIONS.
NO OTHER CHANGES NEEDED AT THIS TIME. PREVIOUS AVIATION DISCUSSION
FOLLOWS...
RAPIDLY DETERIORATING WEATHER WILL CREATE EXTREMELY POOR FLYING
CONDITIONS THROUGHOUT THE FORECAST PERIOD.
PRECIPITATION RAPIDLY EXPANDING INTO THE FORECAST AREA EARLY THIS
MORNING...WITH SNOW NOW FALLING AT ALL TERMINALS. SNOW WILL BECOME
WIDESPREAD AND GRADUALLY HEAVIER AS THE DAY PROGRESSES AS A COLD
FRONT SAGS INTO THE REGION AND LOW PRESSURE OVER ARKANSAS THIS
MORNING TRACKS ALONG THE BOUNDARY INTO THE OHIO VALLEY THIS
AFTERNOON.
AS THE LOW APPROACHES LATER TODAY...MODEL SOUNDINGS INDICATING
WARMER AIR WITHIN THE BOUNDARY LAYER WILL BE DRAWN INTO SOUTHERN
INDIANA...POSSIBLY ALLOWING FOR RAIN TO MIX WITH THE SNOW OR EVEN
SLEET/FREEZING RAIN FOR A BRIEF PERIOD. THE ONLY TERMINAL EXPECTED
TO BE IMPACTED BY THE MIXED PRECIP IS KBMG AND HAVE CONTINUED WITH
RAIN/SNOW FROM LATE MORNING THROUGH MID AFTERNOON. THE WARMER AIR
COMES CLOSE ENOUGH TO KIND THAT A VERY BRIEF PERIOD WITH SLEET
MIXING IN WITH THE SNOW IS NOT ENTIRELY OUT OF THE QUESTION.
CONFIDENCE IS TOO LOW TO MENTION AT THIS POINT BUT WILL NEED TO
MONITOR. AS COLDER AIR RUSHES IN BEHIND THE BOUNDARY BY LATE
AFTERNOON...PRECIP WILL CHANGE TO ALL SNOW AT KBMG.
SNOW WILL BECOME HEAVIEST ACROSS CENTRAL INDIANA THIS AFTERNOON AS
FORCING ALOFT INTENSIFIES AHEAD OF THE LOW. UNDER THE HEAVIEST
BANDS...SNOWFALL RATES OF 1-2 INCHES PER HOUR ARE POSSIBLE. WILL
INTRODUCE 1/4SM AND +SN AT ALL BUT KBMG FROM MID AFTERNOON INTO
THE EVENING. WINDS WILL BECOME NORTHEAST BY MIDDAY THEN
NORTH/NORTHWEST THIS AFTERNOON AS THE LOW PASSES TO THE SOUTH. AS
THE LOW INTENSIFIES...WIND GUSTS TO AROUND 30KTS WILL DEVELOP BY LATE
AFTERNOON. THIS WILL ALLOW FOR BLOWING SNOW IN ADDITION TO THE
SNOWFALL TO DEVELOP AND CONTINUE THIS EVENING.
THE LOW WILL TRACK INTO THE EASTERN GREAT LAKES TONIGHT...WITH
SNOW COMING TO AN END AROUND MIDNIGHT. EVEN AS SNOW ENDS...THE
STRONG WIND GUSTS WILL MAINTAIN BLOWING SNOW ALL NIGHT WITH
REDUCED VISIBILITIES PERSISTING. CEILINGS WILL LIFT TO MFR
OVERNIGHT...WITH SOME BREAKS DEVELOPING TOWARDS DAYBREAK MONDAY AS
DRIER AIR SPREADS INTO THE REGION.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 1 AM EST MONDAY FOR INZ021-028>031-
035>049-051>057-060>065-067>072.
WIND CHILL WARNING FROM 1 AM MONDAY TO 7 PM EST TUESDAY FOR
INZ021-028>031-035>049-051>057-060>065-067>072.
&&
$$
SYNOPSIS...JAS
NEAR TERM...JAS/50
SHORT TERM...JAS
LONG TERM....RYAN
AVIATION...RYAN/JH
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 PADUCAH KY
323 PM CST Sun Jan 5 2014
.SHORT TERM...(This Evening through Monday)
ISSUED AT 323 PM CST SUN JAN 5 2014
Current radar mosiac indicates temporary weakening of pcpn echoes
west of the MS river, however some enhancement is also indicated
over sern MO/swrn IL associated with the exit region of an upper
level jet.
Meanwhile, the nwrn half of the region is under very rapid cold
air advection behind a ewd-departing sfc low, and these very raw
conditions will rapidly sweep across the rest of the region during
the late afternoon. Flash freezing of water on roads is expected.
Dual Pol correlation coefficient from KVWX radar was clearly
showing the rain/snow line beginning to accelerate ewd. Any
intervals of freezing rain or sleet are expected to be even
briefer in duration than they have been up to now.
The HRRR model suggests that the aforementioned enhanced area of
snowfall over sern MO/swrn IL will fill in over most of the region
late this afternoon, except west of Poplar Bluff MO, where
snowfall will taper off rapidly to flurries by sunset.
After sunset, little measurable snowfall is forecast, but
lingering moisture in the new arctic air mass will probably
produce flurries across the entire region into part of the
overnight hours.
A secondary mid level shrtwv will produce clouds and may produce
more flurries during the day Mon. We will flirt with record lows
tonight and Mon night and will shatter minimum highs for Mon.
Dangerous wind chill readings early Mon morning will range from
-20 south to -30 north. The brisk breeze will slowly decrease during
the day. The sun will return Tue, along with "warmer" temps in the teens.
.LONG TERM...(Monday Night through Sunday)
ISSUED AT 323 PM CST SUN JAN 5 2014
Extended models are in general agreement but there are always issues
in the details.
Early Wednesday there is a broad trough over the eastern US with a
more zonal flow over the western US. By Thursday two main troughs
can be seen to our west. One over KS and OK with another off the NW
coast of the US. The first impulse is slow to get here as the
overall pattern changes to a trough in the west and more zonal flow
in the east. But we will have overrunning precipitation both
Wednesday and Thursday.
By 00Z Saturday, the GFS, GEM, and ECMWF want to carve out an upper
level low over the southwest US or Mexico. After that the speed and
intensity of the wave is in question as it moves toward us.
The initial precipitation type will be snow or freezing rain with the
GFS being the warmer model aloft and hence the chance of freezing
rain. Snowfall accumulations will be light but will have to be
monitored. Held off on any ice accumulation until the models have a
better handle on the situation. The good news is that by Friday warm
air has taken over the entire CWA and expect liquid precipitation
over the region through the weekend.
&&
.AVIATION...
ISSUED AT 323 PM CST SUN JAN 5 2014
Location of surface low has required adjustments to changeover time
for all sites. Heaviest precip is now just northwest of KEVV with a
dry slot over parts of SEMO. Changeover to snow has occurred at
KCGI, and KPAH. Expect changeover at KEVV around 21 UTC and KOWB
shortly thereafter. Precip should exit the area late this
afternoon into early evening.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING until 6 PM CST this evening FOR ILZ075>078-
080>089-092-093.
WIND CHILL ADVISORY from 6 PM this evening to 9 AM CST Tuesday
FOR ILZ084>094.
WIND CHILL WARNING from 6 PM this evening to 9 AM CST Tuesday
FOR ILZ075>078-080>083.
WINTER WEATHER ADVISORY until 6 PM CST this evening FOR ILZ090-
091-094.
MO...WINTER STORM WARNING until 6 PM CST this evening FOR MOZ076-086-
087-100-107>111.
WIND CHILL ADVISORY from 6 PM this evening to 9 AM CST Tuesday
FOR MOZ076-086-087-100-107>112-114.
WINTER WEATHER ADVISORY until 6 PM CST this evening FOR MOZ112-
114.
IN...WINTER STORM WARNING until 6 PM CST this evening FOR INZ081-082-
085-086.
WIND CHILL WARNING from 6 PM this evening to 9 AM CST Tuesday
FOR INZ081-082-085>088.
WINTER WEATHER ADVISORY until 6 PM CST this evening FOR INZ087-
088.
KY...WIND CHILL ADVISORY from 6 PM this evening to 9 AM CST Tuesday
FOR KYZ001>022.
WINTER WEATHER ADVISORY until 6 PM CST this evening FOR
KYZ001>022.
&&
$$
SHORT TERM...DB
LONG TERM...PS
AVIATION...PS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1223 PM EST Sun Jan 5 2014
...Updated Aviation Discussion...
...Forecast Update...
Updated at 1150 AM EST Sun Jan 5 2014
Precipitation continues to develop out over western KY this
morning. Strong surge of warm air advection is taking place as
temperatures are nearing 50 degrees down along the KY/TN border
region. Probably will need to adjust our max temperatures for today
down that way a little bit.
Latest 12Z data generally has trended close to the previous 00Z and
06Z runs that were warmer and a little slower with the storm`s
progression through the Ohio Valley. With that said, we feel that
the current snowfall totals over our warning area (southern Indiana)
is a bit too aggressive at this time. After careful coordination
with ILN/IND/PAH we will be downgrading the warning across southern
Indiana to a Winter Weather Advisory. We will also be adjusting the
start time of the advisory products to better align with the
thinking below. The Winter Weather Advisories will also be extended
in time to go throughout the night due to the anticipated high
impacts across the region.
Current prognostic data fields and thermal analysis continues to
show that we will see rain fall across the region this afternoon.
As the surface low pressure system moves through western KY and into
Ohio, a strong Arctic front will push in from the west. This front
will usher in much colder air into the region. It appears that we
will start to see a change over in our western sections around 4-5
PM EST...with a change over occurring in the I-65 corridor between
6-8 PM and in the I-75 corridor in the 9-11 PM time frame. Not
really incorporating much of the NCEP model timing here but this is
more of a blend of our in house high resolution WRF and the
experimental HRRR which appears to have a good handle on the cold
surge coming in from the west.
We still expect to see a band of moderate to heavy snow come in
behind the front. However, this will not last long as it will
quickly move through the region. The models along with upstream
satellite and observations show a dry slot developing across eastern
OK and west-central AR which will likely pivot into our region late
tonight. So while we will get in on the snow, it does not appear
that it will hang around all that much. Though the snowfall is
really the secondary story of this system. Of more concern will be
the tumble in temperatures. We will see temperatures go from the
30s this evening down to near zero by dawn. This will lead to a
quick freeze up of moisture on roads/objects. This combined with
the snow will make travel treacherous tonight.
With regards to snowfall accumulations, we are going to trim back
amounts slightly across southern IN where we believe 2-4 inches is
still likely. The 4 inch amounts would be most likely across our
far northern portions of Dubois, Orange, Washington, Scott, and
Jefferson counties in southern Indiana. Elsewhere across KY a
general 1-3 inches will be possible. This will be a non-uniform
snow...so some areas will pick up an inch here while other areas may
pick up slightly more.
We are currently in the production of updated products and those
should be ready in the next 30-45 minutes. Updated web graphics and
briefing slides will also be available early this afternoon.
Additional meteorological details for later tonight and Monday will
be forthcoming in the standard afternoon discussion which will be
available by mid-afternoon.
Update issued at 830 AM EST Sun Jan 5 2014
Early morning radar mosaics show our winter storm taking aim on the
region. Rain showers have broken out across the region...mainly
west of I-65 with more extensive precipitation out to our north and
northwest. This activity is expected to push eastward throughout
the morning and into the afternoon hours. Much of our eastern
sections...east of US 27/127 will probably remain mostly dry through
the early afternoon hours.
The latest guidance continues to trend warmer, but overall, the
spread and variance in the solutions is starting to diminish
quickly. In general, we should a change over to snow develop to the
west and eventually get into our western counties during the mid
afternoon hours. Based on the latest projections a change over in
the I-65 corridor which includes the Louisville...Elizabethtown...
and Bowling Green areas looks to commence around 6-8 PM EST.
Frankfort and Lexington should see the transition around 8-10 PM
EST. Again, these are just projections and are subject to change
throughout the day.
For now, have adjusted the forecast slightly based on the above
mentioned ideas. This results in a drier forecast for this morning
in the east with a ramp up of wetter conditions toward mid-afternoon
and into the evening hours.
With regards to snowfall amounts, there are signals within the
latest data that suggest a dry punch of air (dry slot) may punch
into the region in the post frontal wake. This could result in
lighter snow accumulations that currently forecast. However...with
regards to impact, the snowfall amounts are not the primary concern
here. The rapid fall of temperatures from the 20s/30s this evening
to near or below zero by morning will lead to a rapid freeze up
tonight making travel quite treacherous. Our plan again today is to
evaluate the 12Z guidance suite this morning and make necessary
adjustments throughout the day.
.SHORT TERM (Now through Monday)...
Issued at 320 PM EST Sat Jan 4 2014
...SIGNIFICANT SNOWS LIKELY ON TODAY WITH HIGHEST ACCUMULATIONS IN
SOUTHERN INDIANA...
...TEMPERATURES TO PLUNGE RAPIDLY THIS EVENING RESULTING IN A
QUICK FREEZE UP AND DANGEROUS WIND CHILLS...
The latest model solutions continue to trend a bit warmer with the
system moving through today. This presents a challenge for
forecasting snowfall totals as they will be highly dependent on how
much moisture remains when temperatures fall enough for rain to
change over to snow. However, even given the warmer solutions, it
still looks like portions of southern Indiana could see some
significant snow accumulations today, with lighter accumulations
along and south of the Ohio River.
Some light radar returns are showing up early this morning over
southern Indiana. Temperatures have remained on the warmer side in
the mid to upper 30s tonight, so this precipitation should be a cold
rain with perhaps some sleet mixed in. As the surface low moves
northeast along the Ohio River today precipitation will spread
across the forecast area from west to east. Warmer air will be
pulled up into central Kentucky and southern Indiana. Thus
precipitation is expected to be mainly rain for most of the region
through the early afternoon hours, though the far northern IN
counties may see some snow mixed in through the day.
As the surface low exits to the northeast late this afternoon it
will drag the cold front through with temperatures plummeting in the
wake of the front. Rain will quickly change over to snow late this
afternoon into this evening as the cold air rushes in behind the
front. Have pushed the changeover back a few more hours from the
previous forecast given the current expected track of the low. As
mentioned in the previous forecast discussion, some bands of snow
may set up with this system and bring bursts of moderate to heavy
snow at times. However, the progressive nature of the system does
look to limit snowfall totals. Did also lower snowfall totals just a
bit, with the highest amounts of around 5 inches in northern Dubois,
Orange and Washington counties in IN. Will leave the Winter Storm
Warning and Advisories in place as is, though the southern tier
counties in the Warning may only reach criteria in part of the
county. Elsewhere, 1-2" of snow is expected in the Advisory areas.
As mentioned, temperatures will fall quickly behind the front. Winds
will pick up with sustained winds of 15-25 mph and gusts up to 35
mph expected tonight and tomorrow. These wind speeds combined with
temperatures dropping to near or below zero Fahrenheit will result
in dangerous wind chills ranging from -15 to -30 F at times. Will
therefore issue a Wind Chill Warning for southern IN and north
central Kentucky and a Wind Chill Advisory for south central
Kentucky beginning at 06Z Monday and running through 18Z Tuesday.
.LONG TERM (Monday Night through Saturday)...
Issued at 330 AM EST Sun Jan 5 2014
...Bitterly Cold Temperatures Early in the Week...Mixed
Precipitation Potential for Mid Week...then Moderating Temperatures
and Rain Chances for Late in Week...
MONDAY NIGHT-TUESDAY...
Bitterly cold temperatures are still on track for early this week
despite how much snow we do or don`t get today. Did come up a
degree or two for low temps Mon night into Tues morning since
forecast snowfall for today is less than initially thought over
much of the area. However, even without a deep snow pack, temps
should still bottom out in the single digits below zero in most
locations Tues morning. Here are the record low temperatures for
Tuesday morning (Jan 7) which will be challenged:
Louisville: -8 in 1912
Lexington: -7 in 1912
Bowling Green: -11 in 1912
With steady westerly winds of 10 to 15 mph expected overnight Monday
through Tues morning, dangerously low wind chills will result.
Expect wind chills of -20 to -30 over southern Indiana and north
central Kentucky where a Wind Chill Warning will be posted. Over
south central KY, wind chills will range from -10 to -20 where a
Wind Chill Advy will be posted.
By Tues afternoon, temps will moderate to the single digits above
zero to lower teens with resulting wind chill values improving to
-5 to 5 range.
Model soundings indicate a very shallow layer of moisture just off
the sfc Mon night which may produce a few scattered flurries over
the region. Tues looks dry as skies become partly cloudy to mostly
sunny throughout the day.
WEDNESDAY-THURSDAY...
Models have come into agreement that a shortwave upper trough will
traverse the southern CONUS pulling up Gulf moisture into the Ohio
Valley Wed night-Thurs night. Models are in decent agreement with
timing but vary some still on QPF amounts. Temp profiles are in
question with quite a spread amongst models still. However, this
overrunning precip setup would lend itself to some sort of wintry
precip. Wed night temps are similar amongst the GFS/ECMWF and would
support an area of snow and/or freezing rain. Thurs/Thurs night,
model temps vary quite a bit so will go with a general rain/snow mix
at this time and refine in coming forecasts. Suspect that after
today`s storm pushes through the region, the models will come into
better agreement for the mid week wintry precip event.
FRIDAY-SATURDAY...
By late in the week, a deeper trough will dive into the southwest
CONUS allowing for better ridging/return flow into the Ohio Valley.
This will result in temperatures returning closer to normal for the
end of the week with more precipitation chances primarily in the
form of rain.
&&
.AVIATION (18Z TAF Update)...
Updated at 1220 PM EST Sun Jan 5 2014
Conditions at the terminals will remain generally VFR early this
afternoon before deteriorating late this afternoon and evening.
Surface low pressure is expected to move northeastward into western
KY this afternoon and into Ohio tonight. As this occurs, a strong
Arctic cold front will swing eastward across the region. Surface
winds will pick up across the region this afternoon and will be
quick brisk. Sustained south to southwesterly winds of 12-15kts
with gusts up to 25kts are likely.
Precipitation out ahead of the front will fall in the form of rain
and then quickly change over to snow in the wake of the front. A
period of moderate to heavy snow will be possible at the terminals
this evening. Best chances of moderate to heavy snow at BWG would
be in the 06/01-02Z range, KSDF between 06/01-03Z and at KLEX
06/03-06Z time range. Ceilings are expected to decrease to the MVFR
range later this afternoon and will likely drop into the IFR range
this evening. Once the snow ends later this evening, ceilings are
likely to recover slightly into the low end of the MVFR range.
As the Arctic front pushes through, expect surface winds to swing
around to the west/northwest and increase in speed. Sustained winds
of 15-20kts with gusts to 30kts will be possible at all the
terminals later this evening and will continue through the overnight
period.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...WINTER WEATHER ADVISORY until 6 AM EST /5 AM CST/ Monday FOR
KYZ023>032-061-062-070>072.
WIND CHILL WARNING from 1 AM EST /Midnight CST/ Monday to 1 PM
EST /Noon CST/ Tuesday FOR KYZ023>043-045>049-053>057-067.
WINTER WEATHER ADVISORY from 7 PM EST /6 PM CST/ this evening to
6 AM EST /5 AM CST/ Monday FOR KYZ033>043-045>049-053>057-
063>067-073>078-081-082.
WIND CHILL ADVISORY from 1 AM EST /Midnight CST/ Monday to 1 PM
EST /Noon CST/ Tuesday FOR KYZ061>066-070>078-081-082.
IN...WINTER WEATHER ADVISORY until 6 AM EST /5 AM CST/ Monday FOR
INZ076>079-083-084-089>092.
WIND CHILL WARNING from 1 AM EST /Midnight CST/ Monday to 1 PM
EST /Noon CST/ Tuesday FOR INZ076>079-083-084-089>092.
&&
$$
Update.........MJ
Short Term.....EER
Long Term......AMS
Aviation.......MJ
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1158 AM EST Sun Jan 5 2014
...Forecast Update...
Updated at 1150 AM EST Sun Jan 5 2014
Precipitation continues to develop out over western KY this
morning. Strong surge of warm air advection is taking place as
temperatures are nearing 50 degrees down along the KY/TN border
region. Probably will need to adjust our max temperatures for today
down that way a little bit.
Latest 12Z data generally has trended close to the previous 00Z and
06Z runs that were warmer and a little slower with the storm`s
progression through the Ohio Valley. With that said, we feel that
the current snowfall totals over our warning area (southern Indiana)
is a bit too aggressive at this time. After careful coordination
with ILN/IND/PAH we will be downgrading the warning across southern
Indiana to a Winter Weather Advisory. We will also be adjusting the
start time of the advisory products to better align with the
thinking below. The Winter Weather Advisories will also be extended
in time to go throughout the night due to the anticipated high
impacts across the region.
Current prognostic data fields and thermal analysis continues to
show that we will see rain fall across the region this afternoon.
As the surface low pressure system moves through western KY and into
Ohio, a strong Arctic front will push in from the west. This front
will usher in much colder air into the region. It appears that we
will start to see a change over in our western sections around 4-5
PM EST...with a change over occurring in the I-65 corridor between
6-8 PM and in the I-75 corridor in the 9-11 PM time frame. Not
really incorporating much of the NCEP model timing here but this is
more of a blend of our in house high resolution WRF and the
experimental HRRR which appears to have a good handle on the cold
surge coming in from the west.
We still expect to see a band of moderate to heavy snow come in
behind the front. However, this will not last long as it will
quickly move through the region. The models along with upstream
satellite and observations show a dry slot developing across eastern
OK and west-central AR which will likely pivot into our region late
tonight. So while we will get in on the snow, it does not appear
that it will hang around all that much. Though the snowfall is
really the secondary story of this system. Of more concern will be
the tumble in temperatures. We will see temperatures go from the
30s this evening down to near zero by dawn. This will lead to a
quick freeze up of moisture on roads/objects. This combined with
the snow will make travel treacherous tonight.
With regards to snowfall accumulations, we are going to trim back
amounts slightly across southern IN where we believe 2-4 inches is
still likely. The 4 inch amounts would be most likely across our
far northern portions of Dubois, Orange, Washington, Scott, and
Jefferson counties in southern Indiana. Elsewhere across KY a
general 1-3 inches will be possible. This will be a non-uniform
snow...so some areas will pick up an inch here while other areas may
pick up slightly more.
We are currently in the production of updated products and those
should be ready in the next 30-45 minutes. Updated web graphics and
briefing slides will also be available early this afternoon.
Additional meteorological details for later tonight and Monday will
be forthcoming in the standard afternoon discussion which will be
available by mid-afternoon.
Update issued at 830 AM EST Sun Jan 5 2014
Early morning radar mosaics show our winter storm taking aim on the
region. Rain showers have broken out across the region...mainly
west of I-65 with more extensive precipitation out to our north and
northwest. This activity is expected to push eastward throughout
the morning and into the afternoon hours. Much of our eastern
sections...east of US 27/127 will probably remain mostly dry through
the early afternoon hours.
The latest guidance continues to trend warmer, but overall, the
spread and variance in the solutions is starting to diminish
quickly. In general, we should a change over to snow develop to the
west and eventually get into our western counties during the mid
afternoon hours. Based on the latest projections a change over in
the I-65 corridor which includes the Louisville...Elizabethtown...
and Bowling Green areas looks to commence around 6-8 PM EST.
Frankfort and Lexington should see the transition around 8-10 PM
EST. Again, these are just projections and are subject to change
throughout the day.
For now, have adjusted the forecast slightly based on the above
mentioned ideas. This results in a drier forecast for this morning
in the east with a ramp up of wetter conditions toward mid-afternoon
and into the evening hours.
With regards to snowfall amounts, there are signals within the
latest data that suggest a dry punch of air (dry slot) may punch
into the region in the post frontal wake. This could result in
lighter snow accumulations that currently forecast. However...with
regards to impact, the snowfall amounts are not the primary concern
here. The rapid fall of temperatures from the 20s/30s this evening
to near or below zero by morning will lead to a rapid freeze up
tonight making travel quite treacherous. Our plan again today is to
evaluate the 12Z guidance suite this morning and make necessary
adjustments throughout the day.
.SHORT TERM (Now through Monday)...
Issued at 320 PM EST Sat Jan 4 2014
...SIGNIFICANT SNOWS LIKELY ON TODAY WITH HIGHEST ACCUMULATIONS IN
SOUTHERN INDIANA...
...TEMPERATURES TO PLUNGE RAPIDLY THIS EVENING RESULTING IN A
QUICK FREEZE UP AND DANGEROUS WIND CHILLS...
The latest model solutions continue to trend a bit warmer with the
system moving through today. This presents a challenge for
forecasting snowfall totals as they will be highly dependent on how
much moisture remains when temperatures fall enough for rain to
change over to snow. However, even given the warmer solutions, it
still looks like portions of southern Indiana could see some
significant snow accumulations today, with lighter accumulations
along and south of the Ohio River.
Some light radar returns are showing up early this morning over
southern Indiana. Temperatures have remained on the warmer side in
the mid to upper 30s tonight, so this precipitation should be a cold
rain with perhaps some sleet mixed in. As the surface low moves
northeast along the Ohio River today precipitation will spread
across the forecast area from west to east. Warmer air will be
pulled up into central Kentucky and southern Indiana. Thus
precipitation is expected to be mainly rain for most of the region
through the early afternoon hours, though the far northern IN
counties may see some snow mixed in through the day.
As the surface low exits to the northeast late this afternoon it
will drag the cold front through with temperatures plummeting in the
wake of the front. Rain will quickly change over to snow late this
afternoon into this evening as the cold air rushes in behind the
front. Have pushed the changeover back a few more hours from the
previous forecast given the current expected track of the low. As
mentioned in the previous forecast discussion, some bands of snow
may set up with this system and bring bursts of moderate to heavy
snow at times. However, the progressive nature of the system does
look to limit snowfall totals. Did also lower snowfall totals just a
bit, with the highest amounts of around 5 inches in northern Dubois,
Orange and Washington counties in IN. Will leave the Winter Storm
Warning and Advisories in place as is, though the southern tier
counties in the Warning may only reach criteria in part of the
county. Elsewhere, 1-2" of snow is expected in the Advisory areas.
As mentioned, temperatures will fall quickly behind the front. Winds
will pick up with sustained winds of 15-25 mph and gusts up to 35
mph expected tonight and tomorrow. These wind speeds combined with
temperatures dropping to near or below zero Fahrenheit will result
in dangerous wind chills ranging from -15 to -30 F at times. Will
therefore issue a Wind Chill Warning for southern IN and north
central Kentucky and a Wind Chill Advisory for south central
Kentucky beginning at 06Z Monday and running through 18Z Tuesday.
.LONG TERM (Monday Night through Saturday)...
Issued at 330 AM EST Sun Jan 5 2014
...Bitterly Cold Temperatures Early in the Week...Mixed
Precipitation Potential for Mid Week...then Moderating Temperatures
and Rain Chances for Late in Week...
MONDAY NIGHT-TUESDAY...
Bitterly cold temperatures are still on track for early this week
despite how much snow we do or don`t get today. Did come up a
degree or two for low temps Mon night into Tues morning since
forecast snowfall for today is less than initially thought over
much of the area. However, even without a deep snow pack, temps
should still bottom out in the single digits below zero in most
locations Tues morning. Here are the record low temperatures for
Tuesday morning (Jan 7) which will be challenged:
Louisville: -8 in 1912
Lexington: -7 in 1912
Bowling Green: -11 in 1912
With steady westerly winds of 10 to 15 mph expected overnight Monday
through Tues morning, dangerously low wind chills will result.
Expect wind chills of -20 to -30 over southern Indiana and north
central Kentucky where a Wind Chill Warning will be posted. Over
south central KY, wind chills will range from -10 to -20 where a
Wind Chill Advy will be posted.
By Tues afternoon, temps will moderate to the single digits above
zero to lower teens with resulting wind chill values improving to
-5 to 5 range.
Model soundings indicate a very shallow layer of moisture just off
the sfc Mon night which may produce a few scattered flurries over
the region. Tues looks dry as skies become partly cloudy to mostly
sunny throughout the day.
WEDNESDAY-THURSDAY...
Models have come into agreement that a shortwave upper trough will
traverse the southern CONUS pulling up Gulf moisture into the Ohio
Valley Wed night-Thurs night. Models are in decent agreement with
timing but vary some still on QPF amounts. Temp profiles are in
question with quite a spread amongst models still. However, this
overrunning precip setup would lend itself to some sort of wintry
precip. Wed night temps are similar amongst the GFS/ECMWF and would
support an area of snow and/or freezing rain. Thurs/Thurs night,
model temps vary quite a bit so will go with a general rain/snow mix
at this time and refine in coming forecasts. Suspect that after
today`s storm pushes through the region, the models will come into
better agreement for the mid week wintry precip event.
FRIDAY-SATURDAY...
By late in the week, a deeper trough will dive into the southwest
CONUS allowing for better ridging/return flow into the Ohio Valley.
This will result in temperatures returning closer to normal for the
end of the week with more precipitation chances primarily in the
form of rain.
&&
.AVIATION (12Z TAF Update)...
Updated at 610 AM EST Sun Jan 5 2014
Conditions will deteriorate through the day today as a low pressure
system moves northeast across the lower Ohio Valley and drags a cold
front through the area. Ceilings will lower to MVFR and then IFR as
rain moves in. Rain will change over to light snow as the cold front
moves through and temperatures drop. Some moderate to heavy snow
bands may develop across the region this afternoon and evening.
However, do not have enough confidence in one setting up over any of
the terminals to include heavier snow in the TAFs at this time. The
snow should end late tonight into early tomorrow morning
Winds will be generally southerly today and will become gusty this
afternoon as the front approaches. In the wake of the front winds
will shift to the WNW and increase to 15-20 knot with gusts to
around 30 knots.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...WINTER WEATHER ADVISORY from 3 PM EST /2 PM CST/ this afternoon
to 6 AM EST /5 AM CST/ Monday FOR KYZ023>032-061-062-
070>072.
WIND CHILL WARNING from 1 AM EST /Midnight CST/ Monday to 1 PM
EST /Noon CST/ Tuesday FOR KYZ023>043-045>049-053>057-067.
WINTER WEATHER ADVISORY from 7 PM EST /6 PM CST/ this evening to
6 AM EST /5 AM CST/ Monday FOR KYZ033>043-045>049-053>057-
063>067-073>078-081-082.
WIND CHILL ADVISORY from 1 AM EST /Midnight CST/ Monday to 1 PM
EST /Noon CST/ Tuesday FOR KYZ061>066-070>078-081-082.
IN...WINTER WEATHER ADVISORY from 3 PM EST /2 PM CST/ this afternoon
to 6 AM EST /5 AM CST/ Monday FOR INZ076>079-083-084-
089>092.
WIND CHILL WARNING from 1 AM EST /Midnight CST/ Monday to 1 PM
EST /Noon CST/ Tuesday FOR INZ076>079-083-084-089>092.
&&
$$
Update.........MJ
Short Term.....EER
Long Term......AMS
Aviation.......EER
AREA FORECAST DISCUSSION
NWS CARIBOU ME
737 PM EST MON JAN 6 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL TRACK WEST OF MAINE THIS AFTERNOON. MUCH COLDER
AIR WILL SWEEP BACK INTO THE AREA BEHIND THIS SYSTEM TONIGHT AND REMAIN
INTO LATE WEEK.&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATE 1935L: QUICK TWEAK TO TEMPERATURES TO ACCOUNT FOR SLIGHTLY
FASTER ADVANCE OF FREEZING LINE.
UPDATE 1825L: ARCTIC FRONTAL BNDRY CURRENTLY BISECTS OUR FA FROM
NE-SW W/ THE FRONT FROM JUST NW OF A KHUL TO KBGR LINE... TEMPS W
OF THIS BNDRY ALREADY COOLING OFF W/ TEMPS JUST BLO FREEZING FAR W
AND NW TO AROUND 32 AT KFVE ATTM. THIS FRONT TO CONT TO MV QUICKLY
EWRD EXITING THE ENTIRE FA AROUND 01-02Z. THEREAFTER MUCH COLDER
AND DRIER AIR WILL RESPREAD ACROSS THE REGION. FOR THIS UPDATE
CYCLE HAVE ADJUSTED POPS AND HRLY TEMPS TO BETTER FIT CURRENT AND
EXPECTED TRENDS THRU THE EVE HRS. ALSO ISSUES AN FA WIDE SPS FOR
HIGHLIGHTING THE THREAT OF BLACK ICE AND SLIPPERY ROADS AS
MOISTURE FROM TODAY/S RAINS AND SNOW MELT FREEZES UP FROM W-E LATER
THIS EVE...
PREV DISC: COLDER TEMPERATURES, FOG AND RE-FREEZING OF THE
STANDING WATER THE MAIN CONCERN FOR TONIGHT. THIS HAS LED TO SOME
HYDROLOGY CONCERNS WHICH ARE ADDRESSED IN THE LAST PARAGRAPH.
STRONG COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT USHERING IN
ANOTHER ROUND OF ARCTIC AIR. WARMER AIR W/RAIN OUT AHEAD OF THE
FRONT WILL BEGIN TO PUSH E THIS EVENING W/TEMPERATURES FALLING
BACK IN WESTERN MAINE LATER THIS AFTERNOON AND THEN REACHING
EASTERN AND NE AREAS AFTER 00Z. RAIN WILL GO TO A PERIOD OF SNOW
BEFORE ENDING AND THIS WILL MAINLY BE ACROSS THE FAR NORTHERN AND
WESTERN AREAS. ANY SNOW ACCUMULATIONS WILL BE LESS THAN AN INCH.
THE LATEST RUN OF THE HRRR WAS DOING REMARKABLY WELL W/THE RAINFALL
AND TEMPERATURES AND FOLLOWED ITS TREND INTO THE NIGHTTIME HOURS.
PRECIP SHOULD END FOR THE ENTIRE CWA BY MIDNIGHT W/PARTIAL CLEARING
THAT COLD AIR PUSHING IN. THE TEMPERATURES WILL REALLY PLUMMET
AFTER MIDNIGHT AS THE ARCTIC TAKES HOLD. READINGS BY EARLY MORNING
ON TUESDAY WILL BE IN THE SINGLE NUMBERS ACROSS NORTHERN AREAS
W/SOME LOCATIONS AOB ZERO ESPECIALLY IN WESTERN AND NORTHWEST
AREAS. ACROSS THE CENTRAL HIGHLANDS AND DOWNEAST, READINGS ARE
EXPECTED TO BE IN THE LOWER TEENS.
THIS COLDER AIR WILL ALLOW FOR THE SETUP FOR A FLASH FREEZE OR A
RE-FREEZE OF ANY STANDING WATER OVERNIGHT. THIS WILL LEAD TO
SLIPPERY ROAD CONDITIONS IN SOME LOCATIONS. A SPECIAL WEATHER
STATEMENT WILL BE ISSUED TO ADDRESS THIS SITUATION.
FOG WILL BE A CONCERN INTO THE EVENING ESPECIALLY ACROSS DOWNEAST
AND THE COAST. VSBYS DOWN ON THE COAST HAVE BEEN AROUND 1/4 OF A
MILE OR LOWER AT TIMES AND RUNNING FROM 1/2 TO 1/4 OF A MILE IN
THE BANGOR AREA. DECIDED TO KEEP WIDESPREAD FOG IN THESE AREAS THROUGH
EARLY EVENING AND ONCE THE COLDER AIR BEGINS TO FILTER IN AND
WINDS TURN WNW, CONDITIONS WILL IMPROVE. FOG ACROSS NORTHERN MAINE
FOR A TIME THIS EVENING BUT IT WILL BE SHORT LIVED.
AS FOR THE WINDS, THE STRONG WINDS THAT OCCURRED EARLIER TODAY
HAVE SINCE ABATED AS THE STRONG LLVL JET(55 KTS) HAS PUSHED TO THE
EAST INTO NEW BRUNSWICK. THEREFORE, THE WIND HEADLINES HAVE BEEN DROPPED.
LASTLY, THERE HAS BEEN CONCERN W/SOME PONDING OF WATER ON AREA
ROADS DUE TO THE SNOW MELT AND RAIN W/SOME STORM DRAINS CLOGGING
LEADING TO MINOR STREET FLOODING. A SURGE UP THE PENOBSCOT RIVER
NEAR BANGOR HAS LED THE CITY OF BANGOR TO CLOSE THE KENDUSKEAG
PLAZA PARKING GARAGE. THE LATEST GAGE HEIGHT WAS JUST AT 11.0 FT
WHICH IS CLOSE TO ACTION STAGE. A FLOOD ADVISORY WAS ISSUED
EARLIER FOR THIS AREA TO ACCOUNT FOR THE PLAY IN THE SURGE AND
REMAINS UP THROUGH THIS EVENING.&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
EXPECT STRONG COLD ADVECTION DURING THE DAY TUESDAY AS INTENSE
LOW PRESSURE OVER NORTHEAST CANADA IN CONJUNCTION WITH STRONG HIGH
PRESSURE OVER THE SOUTH GENERATES A STRONG FLOW FROM THE
NORTHWEST. EXPECT THIS PATTERN TO PERSIST INTO WEDNESDAY THEN
MODERATE AS HIGH PRESSURE BUILDS IN FROM THE WEST DURING THE DAY
THURSDAY THEN CRESTS OVER THE REGION THURSDAY NIGHT. FOR POPS AND
QPF WILL USE A BLEND OF THE NAM12 ...GFS40 ...SREF AND ECMWF. FOR
WINDS HAVE USED THE MOSG25. THE TEMPERATURE GRIDS GENERATED WITH
THE RAW BLEND DUE TO THE EXPECTED CHANGE IN AIRMASS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MILD AND RELATIVELY UNSETTLED LATE THIS WEEK INTO EARLY NEXT WEEK.
HIGH PRESSURE OVERHEAD THURSDAY NIGHT WILL SHIFT TO OUR EAST
FRIDAY INTO SATURDAY, AND WITH THIS WILL COME A WARMER SOUTHWEST
FLOW. THERE LOOKS TO BE A DECENT CHANCE OF PRECIPITATION SATURDAY
AND SATURDAY NIGHT. TEMPERATURES WILL BE WARM ENOUGH FOR MIXED
PRECIPITATION FOR MOST OF THE AREA. TEMPERATURES COOL OFF A BIT
BEHIND THE SYSTEM SUNDAY/SUNDAY NIGHT, BUT NOT EVEN CLOSE TO THE
ARCTIC CHILL WE HAVE BEEN SEEING. THIS LOOKS TO CONTINUE THROUGH
ALL OF NEXT WEEK...A WARMER WEATHER PATTERN WITH FAIRLY WEAK
SYSTEMS IN WHICH WE WILL BE DEALING WITH PRECIPITATION TYPE
CHALLENGES.
MODELS ARE IN FAIRLY GOOD AGREEMENT THURSDAY NIGHT INTO THE
WEEKEND. SOME SLIGHT TIMING ISSUES WITH THE WEEKEND SYSTEM, BUT
NOTHING MAJOR. TIMING OF SYSTEMS INTO EARLY NEXT WEEK BECOMES
SIGNIFICANTLY MORE DIFFICULT.
&&
.AVIATION /01Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: IFR/LIFR ATTM ACROSS THE TERMINALS. CONDITIONS ARE EXPECTED
TO IMPROVE MVFR LATER THIS EVENING AND THEN VFR AFTER MIDNIGHT W/A
WNW WIND TAKING OVER AND COLDER AIR MOVING IN.
SHORT TERM: EXPECT VFR CONDITIONS TUESDAY THROUGH THURSDAY.
&&
.MARINE...
NEAR TERM: LOWERED THE GALE WARNING TO A SCA AS WINDS HAVE COME
DOWN BELOW GALE FORCE. CARRIED GUSTS TO 30 KTS THIS EVENING W/A
FEW GUSTS TO 35 KTS POSSIBLE. WINDS ARE EXPECTED TO COME BACK UP
ON TUESDAY W/THE NW WIND AND SURGE OF CAA OVER THE RELATIVELY
WARMER OCEAN WATERS. WHEN ABOVE THE GUIDANCE ON THE WAVE HEIGHTS
EARLY TONIGHT BY 1-2 FT. A 8-9 SECOND PERIOD SWELL IS THERE ADDING
TO THE WAVE HEIGHTS. WAVE HEIGHTS WILL START TO FALL BACK EARLY
TUESDAY MORNING AS THE WIND BECOMES OFFSHORE.
SHORT TERM: FOR WIND HAVE BLENDED THE NAM12 AND GFS40. FOR WAVES:
LONG FETCH FROM THE GULF OF MAINE SOUTHWARD WILL PERSIST UNTIL IT
IS BROKEN UP BY THE WIND SHIFT LATER TONIGHT. PRIMARY WAVE GROUP
TUESDAY WILL BE FROM THIS FETCH ...6-10 FEET/10-11 SECONDS. EXPECT
THIS LONG PERIOD WAVE GROUP TO PERSIST INTO THURSDAY DUE TO THE
LENGTH OF THE FETCH. WILL USE THE SWAN/NAM TO GENERATE WAVE GRIDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ050>052.
&&
$$
NEAR TERM...FOISY
SHORT TERM...MIGNONE
LONG TERM...FOISY
AVIATION...FOISY/MIGNONE
MARINE...FOISY/MIGNONE
AREA FORECAST DISCUSSION
NWS CARIBOU ME
636 PM EST MON JAN 6 2014
.SYNOPSIS...
STRONG LOW PRESSURE WILL TRACK WEST OF MAINE THIS AFTERNOON. MUCH COLDER
AIR WILL SWEEP BACK INTO THE AREA BEHIND THIS SYSTEM TONIGHT AND REMAIN
INTO LATE WEEK.&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
UPDATE 1825L: ARCTIC FRONTAL BNDRY CURRENTLY BISECTS OUR FA FROM
NE-SW W/ THE FRONT FROM JUST NW OF A KHUL TO KBGR LINE... TEMPS W
OF THIS BNDRY ALREADY COOLING OFF W/ TEMPS JUST BLO FREEZING FAR W
AND NW TO AROUND 32 AT KFVE ATTM. THIS FRONT TO CONT TO MV QUICKLY
EWRD EXITING THE ENTIRE FA AROUND 01-02Z. THEREAFTER MUCH COLDER
AND DRIER AIR WILL RESPREAD ACROSS THE REGION. FOR THIS UPDATE
CYCLE HAVE ADJUSTED POPS AND HRLY TEMPS TO BETTER FIT CURRENT AND
EXPECTED TRENDS THRU THE EVE HRS. ALSO ISSUES AN FA WIDE SPS FOR
HIGHLIGHTING THE THREAT OF BLACK ICE AND SLIPPERY ROADS AS
MOISTURE FROM TODAY/S RAINS AND SNOW MELT FREEZES UP FROM W-E LATER
THIS EVE...
PREV DISC: COLDER TEMPERATURES, FOG AND RE-FREEZING OF THE
STANDING WATER THE MAIN CONCERN FOR TONIGHT. THIS HAS LED TO SOME
HYDROLOGY CONCERNS WHICH ARE ADDRESSED IN THE LAST PARAGRAPH.
STRONG COLD FRONT WILL SWEEP ACROSS THE REGION TONIGHT USHERING IN
ANOTHER ROUND OF ARCTIC AIR. WARMER AIR W/RAIN OUT AHEAD OF THE
FRONT WILL BEGIN TO PUSH E THIS EVENING W/TEMPERATURES FALLING
BACK IN WESTERN MAINE LATER THIS AFTERNOON AND THEN REACHING
EASTERN AND NE AREAS AFTER 00Z. RAIN WILL GO TO A PERIOD OF SNOW
BEFORE ENDING AND THIS WILL MAINLY BE ACROSS THE FAR NORTHERN AND
WESTERN AREAS. ANY SNOW ACCUMULATIONS WILL BE LESS THAN AN INCH.
THE LATEST RUN OF THE HRRR WAS DOING REMARKABLY WELL W/THE RAINFALL
AND TEMPERATURES AND FOLLOWED ITS TREND INTO THE NIGHTTIME HOURS.
PRECIP SHOULD END FOR THE ENTIRE CWA BY MIDNIGHT W/PARTIAL CLEARING
THAT COLD AIR PUSHING IN. THE TEMPERATURES WILL REALLY PLUMMET
AFTER MIDNIGHT AS THE ARCTIC TAKES HOLD. READINGS BY EARLY MORNING
ON TUESDAY WILL BE IN THE SINGLE NUMBERS ACROSS NORTHERN AREAS
W/SOME LOCATIONS AOB ZERO ESPECIALLY IN WESTERN AND NORTHWEST
AREAS. ACROSS THE CENTRAL HIGHLANDS AND DOWNEAST, READINGS ARE
EXPECTED TO BE IN THE LOWER TEENS.
THIS COLDER AIR WILL ALLOW FOR THE SETUP FOR A FLASH FREEZE OR A
RE-FREEZE OF ANY STANDING WATER OVERNIGHT. THIS WILL LEAD TO
SLIPPERY ROAD CONDITIONS IN SOME LOCATIONS. A SPECIAL WEATHER
STATEMENT WILL BE ISSUED TO ADDRESS THIS SITUATION.
FOG WILL BE A CONCERN INTO THE EVENING ESPECIALLY ACROSS DOWNEAST
AND THE COAST. VSBYS DOWN ON THE COAST HAVE BEEN AROUND 1/4 OF A
MILE OR LOWER AT TIMES AND RUNNING FROM 1/2 TO 1/4 OF A MILE IN
THE BANGOR AREA. DECIDED TO KEEP WIDESPREAD FOG IN THESE AREAS THROUGH
EARLY EVENING AND ONCE THE COLDER AIR BEGINS TO FILTER IN AND
WINDS TURN WNW, CONDITIONS WILL IMPROVE. FOG ACROSS NORTHERN MAINE
FOR A TIME THIS EVENING BUT IT WILL BE SHORT LIVED.
AS FOR THE WINDS, THE STRONG WINDS THAT OCCURRED EARLIER TODAY
HAVE SINCE ABATED AS THE STRONG LLVL JET(55 KTS) HAS PUSHED TO THE
EAST INTO NEW BRUNSWICK. THEREFORE, THE WIND HEADLINES HAVE BEEN DROPPED.
LASTLY, THERE HAS BEEN CONCERN W/SOME PONDING OF WATER ON AREA
ROADS DUE TO THE SNOW MELT AND RAIN W/SOME STORM DRAINS CLOGGING
LEADING TO MINOR STREET FLOODING. A SURGE UP THE PENOBSCOT RIVER
NEAR BANGOR HAS LED THE CITY OF BANGOR TO CLOSE THE KENDUSKEAG
PLAZA PARKING GARAGE. THE LATEST GAGE HEIGHT WAS JUST AT 11.0 FT
WHICH IS CLOSE TO ACTION STAGE. A FLOOD ADVISORY WAS ISSUED
EARLIER FOR THIS AREA TO ACCOUNT FOR THE PLAY IN THE SURGE AND
REMAINS UP THROUGH THIS EVENING.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
EXPECT STRONG COLD ADVECTION DURING THE DAY TUESDAY AS INTENSE
LOW PRESSURE OVER NORTHEAST CANADA IN CONJUNCTION WITH STRONG HIGH
PRESSURE OVER THE SOUTH GENERATES A STRONG FLOW FROM THE
NORTHWEST. EXPECT THIS PATTERN TO PERSIST INTO WEDNESDAY THEN
MODERATE AS HIGH PRESSURE BUILDS IN FROM THE WEST DURING THE DAY
THURSDAY THEN CRESTS OVER THE REGION THURSDAY NIGHT. FOR POPS AND
QPF WILL USE A BLEND OF THE NAM12 ...GFS40 ...SREF AND ECMWF. FOR
WINDS HAVE USED THE MOSG25. THE TEMPERATURE GRIDS GENERATED WITH
THE RAW BLEND DUE TO THE EXPECTED CHANGE IN AIRMASS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MILD AND RELATIVELY UNSETTLED LATE THIS WEEK INTO EARLY NEXT WEEK.
HIGH PRESSURE OVERHEAD THURSDAY NIGHT WILL SHIFT TO OUR EAST
FRIDAY INTO SATURDAY, AND WITH THIS WILL COME A WARMER SOUTHWEST
FLOW. THERE LOOKS TO BE A DECENT CHANCE OF PRECIPITATION SATURDAY
AND SATURDAY NIGHT. TEMPERATURES WILL BE WARM ENOUGH FOR MIXED
PRECIPITATION FOR MOST OF THE AREA. TEMPERATURES COOL OFF A BIT
BEHIND THE SYSTEM SUNDAY/SUNDAY NIGHT, BUT NOT EVEN CLOSE TO THE
ARCTIC CHILL WE HAVE BEEN SEEING. THIS LOOKS TO CONTINUE THROUGH
ALL OF NEXT WEEK...A WARMER WEATHER PATTERN WITH FAIRLY WEAK
SYSTEMS IN WHICH WE WILL BE DEALING WITH PRECIPITATION TYPE
CHALLENGES.
MODELS ARE IN FAIRLY GOOD AGREEMENT THURSDAY NIGHT INTO THE
WEEKEND. SOME SLIGHT TIMING ISSUES WITH THE WEEKEND SYSTEM, BUT
NOTHING MAJOR. TIMING OF SYSTEMS INTO EARLY NEXT WEEK BECOMES
SIGNIFICANTLY MORE DIFFICULT.
&&
.AVIATION /00Z TUESDAY THROUGH SATURDAY/...
NEAR TERM: IFR/LIFR ATTM ACROSS THE TERMINALS. CONDITIONS ARE EXPECTED
TO IMPROVE MVFR LATER THIS EVENING AND THEN VFR AFTER MIDNIGHT W/A
WNW WIND TAKING OVER AND COLDER AIR MOVING IN.
SHORT TERM: EXPECT VFR CONDITIONS TUESDAY THROUGH THURSDAY.
&&
.MARINE...
NEAR TERM: LOWERED THE GALE WARNING TO A SCA AS WINDS HAVE COME
DOWN BELOW GALE FORCE. CARRIED GUSTS TO 30 KTS THIS EVENING W/A
FEW GUSTS TO 35 KTS POSSIBLE. WINDS ARE EXPECTED TO COME BACK UP
ON TUESDAY W/THE NW WIND AND SURGE OF CAA OVER THE RELATIVELY
WARMER OCEAN WATERS. WHEN ABOVE THE GUIDANCE ON THE WAVE HEIGHTS
EARLY TONIGHT BY 1-2 FT. A 8-9 SECOND PERIOD SWELL IS THERE ADDING
TO THE WAVE HEIGHTS. WAVE HEIGHTS WILL START TO FALL BACK EARLY
TUESDAY MORNING AS THE WIND BECOMES OFFSHORE.
SHORT TERM: FOR WIND HAVE BLENDED THE NAM12 AND GFS40. FOR WAVES:
LONG FETCH FROM THE GULF OF MAINE SOUTHWARD WILL PERSIST UNTIL IT
IS BROKEN UP BY THE WIND SHIFT LATER TONIGHT. PRIMARY WAVE GROUP
TUESDAY WILL BE FROM THIS FETCH ...6-10 FEET/10-11 SECONDS. EXPECT
THIS LONG PERIOD WAVE GROUP TO PERSIST INTO THURSDAY DUE TO THE
LENGTH OF THE FETCH. WILL USE THE SWAN/NAM TO GENERATE WAVE GRIDS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 5 AM EST TUESDAY FOR ANZ050>052.
&&
$$
NEAR TERM...KHW/HEWITT
SHORT TERM...MIGNONE
LONG TERM...FOISY
AVIATION...KHW
MARINE...KHW/HEWITT/MIGNONE
AREA FORECAST DISCUSSION
NWS GRAY ME
253 PM EST SUN JAN 5 2014
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTH ALONG A STALLED FRONTAL BOUNDARY
WELL TO THE WEST OF THE FORECAST AREA OVERNIGHT. LOW PRESSURE WILL
CONTINUE NORTH THROUGH WESTERN QUEBEC ON MONDAY AND WILL DRIVE A
STRONG COLD FRONT THROUGH THE REGION MONDAY AFTERNOON. A STRONG
WESTERLY FLOW WILL PREVAIL BEHIND THE FRONT MONDAY NIGHT THROUGH
TUESDAY. HIGH PRESSURE WILL BUILD IN FROM THE SOUTH WEDNESDAY
THROUGH THURSDAY. A WARM FRONT WILL LIFT NORTH INTO THE FORECAST
AREA THURSDAY NIGHT AND WILL PUSH NORTHEAST OF THE REGION ON
FRIDAY. A COLD FRONT WILL PUSH THROUGH THE REGION FROM THE WEST ON
SATURDAY WITH HIGH PRESSURE TO FOLLOW ON SUNDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
VERY INTERESTING SETUP WITH LOW PRESSURE PASSING WELL TO OUR WEST
OVERNIGHT. HOWEVER...AT THE SAME TIME...A WEAK AREA OF LOW
PERSSURE HAS ALREADY FORMED ALONG THE MID ATLANTIC COASTLINE. THIS
IS AHEAD OF AND TO THE NORTH OF ALL MODELED GUIDANCE AT THIS TIME.
EVEN THE MESO MODELS ARE HAVING A DIFFICULT TIME THIS MORNING...AS
THEY ARE NOT CAPTURING THE PRECIPITATION OVER SOUTHERN NEW ENGLAND
AT THE MOMENT.
IN ANY CASE...PRECIPITATION WILL ENTER THE FORECAST AREA THIS
EVENING. HAVE LEANED TOWARDS A COLD SOLUTION...A TAD COOLER THAN
ALL AVAILABLE GUIDANCE. ATMOSPHERE STILL VERY COLD AND DRY...AND
THERE WILL BE PLENTY OF EVAPORATION COOLING AS EVIDENT ON 12Z GYX SOUNDING.
THEREFORE...HAVE EXPANDED THE WINTER WX ADIVSORIES TO INCLUDE THE
COASTLINE. LATEST HRRR KEEPS TEMPERATURES BELOW FREEZING FOR MUCH
OF THE COAST THROUGH AT LEAST MIDNIGHT BEFORE THE WARM UP. WARM UP
MAY BE A TAD EARLIER AT PSM AND ALONG THE NH SEACOAST.
ENOUGH DRY AIR IN PLACE TO POSSIBLY HOLD FOR SEVERAL HOURS OF
SNOWFALL IN THE USUAL SUSPECT LOCATION OF THE FOOTHILLS. GFS
ACTUALLY PICKS UP ON THIS FEATURE.
USED A NON-DUIRNAL CURVE FOR THE OVERNIGHT MINS.
HAVE SENT FORECAST SNOWFALL AND ICE MAPS. ICE WILL BE A SENSITIVE
ISSUE AS WE HAVE HAD REPORTS OF ICE STILL IN THE TREES FROM THE
ICE STORM PRIOR TO THE HOLIDAYS.
&&
.SHORT TERM /MONDAY THROUGH MONDAY NIGHT/...
STRONG COLD FRONT WILL CROSS THE REGION MONDAY AFTER A SIGNIFICANT
WARM UP DURING THE AFTERNOON. TEMPS WILL GO FROM WELL IN THE
40S...TO A DEEP FREEZE OVER A SHORT PERIOD OF TIME. STRONGEST
WINDS WILL HOLD OFF UNTIL THE PASSAGE OF THE UPPER LEVEL TROUGH.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
MORE BITTERLY COLD ARCTIC AIR IS EXPECTED TUESDAY THRU WEDNESDAY
ON GUSTY WESTERLY WINDS WHICH WILL CREATE EXTREMELY COLD WIND
CHILLS. THE UPSLOPE WESTERLY FLOW UNDER THE UPR LEVEL SYSTEM WILL
CREATE SCT -SHSN ACROSS THE N/MT ZONES.
FINALLY AS HIGH PRESSURE BUILDS IN FROM THE WEST AND THE AIR MASS
CONTINUES TO WARM WE SHOULD SEE TEMPS CLIMB BACK TO MORE NORMAL
LEVELS ALONG WITH LIGHTER WINDS ON THURSDAY. LATE THURSDAY NIGHT
AND FRIDAY A WARM FRONT WITH WAA ALOFT WILL MOVE ACROSS NORTHERN
NEW ENGLAND CREATING SOME LIGHT SNOW SHOWERS ON FRIDAY INTO FRI EVENING.
TEMPS SHOULD REMAIN COLD ENOUGH TO BE SNOW. HIGH PRES AND A WARMER
AIR MASS WILL TAKE CONTROL FOR SATURDAY.
USED THE SUPERBLEND FOR TEMPS AND POPS.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
SHORT TERM...CONDITIONS DETEORATING TO IFR AND LIFR WITH FOG AND
LOW CEILINGS DEVELOPING LATER TONIGHT. CONDITIONS IMPROVE MONDAY AFTERNOON.
LONG TERM...
MVFR IN SCT -SHSN MTN AREAS TUESDAY. GUSTY W WINDS THRU TUESDAY
NGT AND INTO WEDNESDAY. MVFR CONDS PSBL FRI IN SCT SNW SHWRS.
&&
.MARINE...
SHORT TERM...HAVE ISSUED GALES FOR THE OUTER WATERS AND PENOBSCOT
BAY FOR LATE TONIGHT AND MONDAY WITH A STRONG SOUTHERLY GRADIENT.
SCA IN PLACE FOR CASCO BAY.
LONG TERM...
AN EXTENDED PERIOD OF FAIRLY STRONG WINDS AND ROUGH SEAS WITH AT
LEAST SCA CONDITIONS (AND POSSIBLY GALES OVER THE OPEN WATERS)
THRU TUESDAY NGT AND INTO WEDNESDAY. WINDS THEN SEAS SLOWLY EASE
UP LATE WEDNESDAY THRU THURSDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
MONDAY FOR MEZ018.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 10 AM EST
MONDAY FOR MEZ007>009-012>014-019>022.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 3 AM EST
MONDAY FOR MEZ023>028.
NH...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
MONDAY FOR NHZ003>010-013.
WINTER WEATHER ADVISORY FROM 9 PM THIS EVENING TO 10 AM EST
MONDAY FOR NHZ001-002.
WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 3 AM EST
MONDAY FOR NHZ014.
MARINE...SMALL CRAFT ADVISORY FROM 3 AM TO 3 PM EST MONDAY FOR ANZ153.
GALE WARNING FROM 3 AM TO 3 PM EST MONDAY FOR ANZ150>152-154.
&&
$$
JC/RAM
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
910 PM EST MON JAN 6 2014
.SYNOPSIS...
THE ARCTIC AIRMASS OVER THE UPPER OHIO VALLEY REGION WILL MODERATE
QUICKLY DURING THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
LATE EVE UPDATE MAINLY FEATURED TWEAKS TO HOURLY TRENDS OF WEA
AND WIND GUSTS.
PREVIOUS...
EARLY EVE UPDATE WAS ISSUED TO DROP THE WINTER WEATHER ADVISORY
FOR THE RIDGE ZONES AS ADDITIONAL SNOW ACCUMULATION WL BE MINOR
AND AREAS OF BLOWING SNOW WL LIKELY CAUSE ONLY LOCALIZED ISSUES.
OTHERWISE...HAVE ADJUSTED POPS AND SFC WIND BASED ON THE LATEST
OBS...RADAR...AND DETERMINISTIC MDL TRENDS. HAVE DIMINISHED GUSTS
MAINLY OVR THE RIDGES AS PER LATEST RAP AND NAM MOMEMTUM TRANSFER
PROGNOSIS...AS INVERSION LVLS WL LIKELY PREVENT DEEP MIXING OF
HIGHER WIND VALUES.
IN GENL...SUB ZERO AIR WL CONT TO SLIDE OVR THE REGION AS THE EVE
PROGRESSES...HENCE MOST DETAIL CHANGES ARE COSMETIC AND WIND CHILL
WARNING CONTS.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
DRY AND COLD CONDITIONS WL PREVAIL THROUGH THROUGH TUESDAY NGT AND
WIND CHILL WARNING WAS CONTD FOR NOW. ALTHOUGH DIMINISHING WIND
AND WARM ADVCTN MAY PREVENT ACTUAL CRITERIA FM BEING REACHED AFTR
DARK ON TUESDAY...NO POINT TO HEADLINE ALTERATION AT THIS TIME.
THAT WARM ADVECTION REGIME WL INTENSIFY AND RTN TEMPS TWD THE
SEASONAL AVGS AS A SHRTWV IS PROJECTED ACRS THE GREAT LAKES ON
WED...WHILE ANOTHER IS PROGGED OUT OF THE LOWER OHIO ON THURSDAY.
SNOW CHCS HAVE BEEN MAINTAINED FOR THOSE FEATURES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS REMAIN CONSISTENT IN BRINGING A SHORTWAVE TROUGH AT 500MB
ACROSS REGION THURSDAY NIGHT. UPPED POPS TO COINCIDE WITH THIS
FEATURE AND QUICKLY PUSH THE FOCUS OF THESE CHC POPS EAST...DRYING
BEHIND IT. NOT ALTERING THE TEMPERATURES MUCH THURS AND FRI
MORNING...SO A PRIMARILY SNOW PTYPE EVENT REMAINS THE THINKING.
SIGNIFICANT WARM UP PROGGED FOR THE WEEKEND AS RIDGING TAKES PLACE
BEHIND EXITING SHORTWAVE. 850MB TEMPS REBOUND FROM NEAR FREEZING TO
8 TO 10C SAT ON THE GFS. BUMPED UP TEMPERATURES A FEW DEGREES ACROSS
THE BOARD AS WE GO ABOVE AVERAGE FOR THIS TIME OF YEAR. A WELCOMED
CHANGE BY MOST FROM THE COLD OF THE LAST WEEK. ANOTHER QUICK MOVING
SYSTEM IS POISED TO MOVE THROUGH SAT...BUT ONLY MODEST CAA BEHIND IT
KEEPS OUR TEMPERATURES FROM FALLING OFF DRAMATICALLY. ANOTHER SYSTEM
APPROACHES FROM THE SOUTH TO START NEXT WORK WEEK...BUT CONSIDERABLE
TIMING AND STRUCTURE DIFFERENCES EXIST ON HOW TO HANDLE THE SOUTHERN
CUTOFF TRACKING ACROSS THE SOUTHEAST.
&&
.AVIATION /02Z TUESDAY THROUGH SATURDAY/...
ALTHOUGH GENERAL VFR WL RTN THIS EVENING AND CONT INTO TUESDAY...SFC
WIND WL RMN AN AVIATION CONCERN WITH GUSTS TO ARND 25 KT CONTG.
.OUTLOOK.../MONDAY NIGHT THROUGH FRIDAY/...
THE NEXT CHANCE FOR RESTRICTIONS WL COME WITH CROSSING DISTURBANCES
ON WEDNESDAY AND THURSDAY.
&&
.CLIMATE...
A SUMMARY OF SIGNIFICANT COLD TEMPERATURE READINGS IS INCLUDED
BELOW...
CITY MON/TUE LAST DATE LAST DATE LAST DATE
RECORD(YEAR) BELOW -10 BELOW 0 HIGH BELOW 0
PITTSBURGH -5(1942)/-5(1884) 1/17/2009 1/22/2011 1/19/1994
MORGANTOWN -1(1988)/-4(1970) 1/21/1994 1/17/2009 1/19/1994
ZANESVILLE -3(1959)/-3(1968) 1/22/2011 1/24/2011 1/19/1994
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR MDZ001.
OH...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR OHZ039>041-
048>050-057>059-068-069.
PA...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR PAZ007>009-
013>016-020>023-029-031-073>076.
WV...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR WVZ001>004-
012-021>023-041.
&&
$$
15
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1232 AM EST SUN JAN 5 2014
.SYNOPSIS...
A WARM FRONT FROM THE WEST AND A DEVELOPING COASTAL LOW WILL BRING
ANOTHER ROUND OF PRECIPITATION TO THE AREA LATE TONIGHT INTO
SUNDAY. A STRONG COLD FRONT WILL CROSS THE REGION LATE SUNDAY
NIGHT INTO MONDAY MORNING...FOLLOWED BY A VERY COLD ARCTIC AIRMASS
FOR MONDAY AFTERNOON INTO MID-WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
SEASONABLE CHILL RMNS OVR THE RGN AS SFC HI PRES DRIFTS OFF THE
CST. WNDS HAVE BECOME SSE OVR THE ENTIRE FA...GENERALLY AVGG 10
MPH OR LESS. CLOUDS CONTINUE TO SPREAD NORTHEAST ACROSS THE AREA.
ALREADY REACHING THE RICHMOND AREA THIS EVENING. LOOKING SOUTHEAST
WHERE THE CLOUDS HAVE BEEN ADVECTING UP FROM CAN SEE A SOLID DECK
OF CLOUDS. THE RUC AND 18Z NAM SHOW THIS MOISTURE GENERALLY FROM
85H AND UNDER. THIS WILL HOLD TEMPS UP AS CONTINUED SE FLOW BRINGS
IN STEADILY MILDER AIR. HAVE RAISED SOME TEMPERATURES A LITTLE AND
WHERE THE CLOUDS HAVE ARRIVED HAVE NOT DROPPED TEMPERATURES AT
ALL. THIS MEANS THE ONLY AREA NOW EXPECTING TO SETTLE BELOW
FREEZING IS THE AREA FROM FVX NORTH THROUGH LOUISA. MDLS ARE
DIVERGENT WRT POPS/PCPN...GFS SLOWER AND "DRIER" (W/ JUST LWRG
CIGS)...WHILE THE NAM BRINGS IN AT LEAST LGT PCPN TO SCNTRL AND
WRN PORTIONS OF THE FA AFT 06-09Z/05. TIME SECTIONS SHOW LITTLE OR
NO MOISTURE REACHING NEAR THE MINUS 10 ISOTHERM SO WOULD NOT
EXPECT MORE THEN VERY LIGHT PRECIPITATION OR DRIZZLE THROUGH THE
NIGHT. ALSO HRRR SEEMS TO HAVE A GOOD HANDLE ON WHERE THE DRIZZLE
AND LIGHT PRECIPITATION IS OCCURRING OVER SOUTH CAROLINA AND THAT
HOLDS OFF ANY PRECIPITATION UNTIL AROUND SUNRISE IN THE SOUTHWEST. THERE
IS LO CONFIDENCE RIGHT NOW FOR ANYTHING MORE THAN A TRACE QPF
EVENT... NO HEADLINES ATTM...KEEPING MENTION IN HWO OF POSSIBLE
FREEZING PRECIPITATION AROUND SUNRISE.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH TUESDAY/...
MILDER/WARMER WX XPCD SUN INTO SUN NGT AHD OF APPROACHING LO PRES
AND ASSOCIATED CDFNT FM THE W AND WK CSTL LO PRES TRACKING JUST
OFF THE NC CST. VERY LIMITED DEPTH TO MOISTURE CONTG TO SPREAD OVR
THE RGN DURG SUN...WHICH LIKELY MEANS THAT ANY PCPN WOULD BE
LGT...AND MAY BE CONFINED TO AREAS INLAND/AWAY FM THE CST. THERE
WILL RMN RESIDUAL CAD W OF I95 ON SUN WHILE THE WARMER AIR ARRIVES
NWD ELSW. HI TEMPS FM THE L/M40S NW TO THE U50S/L60S IN SE VA/NE
NC.
THE WK CSTL LO TRACKS TO THE NE AND AWAY FM THE RGN SUN
EVE...WHILE A STRONG CDFNT APPROACHES THE MTNS. THAT FNT MAKES ITS
WAY ACRS THE MTNS AND ONTO THE PIEDMONT SUN NGT THROUGH MON
MRNG...ACCOMPANIED BY A BAND/AREA OF RA (WHICH MAY MIX W/ SN ON
WRN SIDE AS COLDER AIR BEGINS TO ARRIVE). THAT CDFNT CONTS TO PUSH
ACRS THE FA DURG TUE...PUSHING OFF THE CST BY MID/LT MON
AFTN...USHERING IN ANOTHER SHOT OF VERY COLD/ARCTIC AIR ON INCRSG
NW WNDS. SCT-LIKELY SHRAS ACCOMPANY THE FNTL PASSAGE ON
MON...WHICH MAY END AS ISOLD/SCT SHSN AS THE COLDER AIR CONTS IT
MARCH EWD INTO THE FA (AND TEMPS FALL THROUGHOUT THE MIDDAY/AFTN
HRS). LO TEMPS SUN NGT M/U30S FAR W...TO L50S SE. HI TEMPS MON (IN
THE MRNG) FM ARND 40F W TO L50S SE.
WHAT MAY END OF BEING THE COLDEST SHOT OF AIR INTO THE RGN SINCE
FEB 1996 (OR JAN 1994) MON NGT THROUGH TUE. ISOLD/SCT SHSN ARE
PSBL INVOF CST/OVR THE OCN (H85 TEMPS DROP TO BLO -18 DEGS C BY
12Z/07). OTRW...CLR TO PCDY...W/ LO TEMPS FM THE SINGLE DIGITS TO
TEENS (MON NGT)...THEN HI TEMPS NO HIGHER THAN THE TEENS AND L20S
ON TUE. WIND CHILLS MAY DROP TO OR BLO 0 DEGS F FOR A TIME FM LT
MON INTO TUE (AS WNDS AVGG 15-25 MPH...W/ GUSTS TO 35-40 MPH
PSBL).
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
ARCTIC HIGH PRESSURE BUILDS OVERHEAD TUESDAY NIGHT WITH CURRENT
FORECAST LOWS IN THE TEENS. THE HIGH REMAINS OVER THE AREA
WEDNESDAY...WHICH WILL LIMIT MIXING AND RESULT IN HIGHS
GENERALLY IN THE 30S AREAWIDE. DRY AND MAINLY CLEAR CONDITIONS ARE
EXPECTED TUESDAY NIGHT THROUGH WEDNESDAY...ASIDE FROM ANY COLD-AIR
CUMULUS STREAMERS OFF THE BAY. THE ARCTIC HIGH SLIDES OFF THE MID
ATLANTIC COAST WEDNESDAY NIGHT AND THURSDAY. MEANWHILE...A
SHORTWAVE DISTURBANCE APPROACHES FORM THE WEST THURSDAY...AND
TRAVERSES ACROSS THE MID ATLANTIC REGION THURSDAY NIGHT INTO
FRIDAY MORNING. SURFACE TEMPERATURES SHOULD RISE ABOVE 32 F ACROSS
THE ENTIRE LOCAL AREA BY THE TIME ANY LIGHT PRECIP ARRIVES...SO
ALL PRECIP IS STILL EXPECTED TO BE RAIN. HIGHS WILL BE NEAR
SEASONAL AVERAGES THURSDAY AS CLOUD COVER AND LIMITED MIXING WILL
PREVENT HIGHS FROM REACHING THEIR FULL POTENTIAL. ADDITIONAL
SHORTWAVE ENERGY/MOISTURE IS EXPECTED TO CROSS THE AREA AT TIMES
FROM FRIDAY THROUGH THE WEEKEND AS ANOTHER LONGWAVE TROUGH DIGS
OVER THE CENTRAL U.S.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
MOISTURE QUICKLY SPREADING NORTH IN THE FORM OF A BKN-OVC SC DECK
(BTWN 2-4K FT ACROSS THE PIEDMONT AND 4-6K FT ALONG THE COAST).
LATEST MODELS CONTINUE THIS MVFR-VFR TREND AND KEEP IT DRY THROUGH
12Z...ALTHOUGH SOME DRIZZLE MAY DEVELOP AROUND SUNRISE IVOF RIC.
CHALLENGING FORECAST ON WHEN COLUMN BECOMES SATURATED ENOUGH FOR
IFR CONDITIONS AS ANY PCPN SHOULD REMAIN RATHER LIGHT THROUGH
18Z AND EVEN LATER ALONG THE COAST. EXPECT STRATUE ALONG WITH
PERIODS OF LIGHT RAIN/DRIZZLE TO LOWER TOWARD IFR CONDITIONS BY
MID AFTERNOON AT RIC...THEN ALONG COASTAL SECTIONS BEFORE 00Z MON.
IFR CIGS AND PCPN CONTINUE SUNDAY NIGHT AHEAD OF ARCTIC COLD FRONT
EXPECTED TO CROSS THE AREA MONDAY MORNING.
CHANCE OF SHOWERS CONTINUE WITH THE COLD FRONT MONDAY. GIVEN THE
STRONG CAA...COULD SEE RAIN SHOWERS MIX WITH OR BRIEFLY CHANGE TO
SNOW SHOWERS BEFORE. GUSTY NW WINDS DRY OUT COLUMN MON NGT / TUE.
&&
.MARINE...
SEAS ACROSS THE NORTHERN OUTER BANKS CONTINUE TO HOVER BETWEEN 5-6
FT...SO EXTENDED THE SCA THERE THROUGH 4 AM.
PVS DSCN:
SCA CONTINUES FOR SRN WATERS UNTIL 1 AM EDT FROM THE VA/NC BORDER
TO CURRITUCK LIGHT. SEAS OF 5 TO 7 FT WILL PERSIST DURING THIS
TIME BEFORE SUBSIDING BELOW 5 FT. A COASTAL LOW BEGINS TO TAKE
SHAPE OFF THE FL COAST BY SUN MORNING...THEN DEEPENS AS IT TRACKS
ALONG THE CAROLINA COAST TWD THE MID ATLANTIC WATERS DURING THE
DAY. THE PRESSURE GRADIENT WILL TIGHTEN AS THE DAY PROGRESSES DUE
TO A VERY STRONG ARCTIC COLD FRONT MOVING INTO THE TN/OH VALLEYS.
THIS WILL CAUSE SE WINDS TO GRADUALLY INCREASE BY SUN AFTN. THE
COASTAL LOW IS USHERING A WAA REGIME OVER THE WATERS DURING THIS
TIME AND DO NOT ANTICIPATE MUCH SUCCESS IN MIXING DOWN STRONGER
WINDS ALOFT. WILL KEEP WINDS CAPPED JUST BELOW SCA CRITERIA (15 KT
BAY/RIVERS/SOUND...25 KT OCEAN) FROM SUN AFTN INTO SUN NIGHT.
THE AFOREMENTIONED ARCTIC COLD FRONT IS EXPECTED TO RAPIDLY
STRENGTHEN SUN NIGHT INTO MON MORNING AS IT MOVES FROM THE OH/TN
VALLEYS INTO THE ERN GREAT LAKES REGION. THE VERY STRONG ARCTIC
COLD FRONT ASSOCIATED WITH THIS SYSTEM IS EXPECTED TO CROSS THE
WATERS MON MORNING THROUGH EARLY AFTN. S WINDS OF 20-25 KT MON
MORNING WILL QUICKLY VEER TO THE NW BEHIND THE VIGOROUS FRONTAL
PASSAGE AND INCREASE TO 25-30 KT. GUSTS UP TO 40 KT SHOULD BE
ANTICIPATED OVER THE COASTAL WATERS IN ADDITION TO LOW-END GALE
FORCE GUSTS POSSIBLE ON CHES BAY. WAVES/SEAS ARE ALSO EXPECTED TO
RAPIDLY BUILD IN THE VICINITY OF THE COLD FRONT (CHES BAY WAVES
4-5 FT/COASTAL WATERS SEAS 5-8 FT). ALTHOUGH FORECAST MODELS HAVE
BEEN FAIRLY CONSISTENT WITH THE TIMING OF THE FRONTAL PASSAGE ON
MON...AM CONCERNED THAT A DEEP LONGWAVE TROUGH OVER THE CTRL U.S.
WILL DIG A BIT DEEPER THAN EXPECTED. IF THIS OCCURS...THEN THE
FRONTAL PASSAGE COULD BE SLOWED BY A FEW HOURS AND THUS DELAY THE
ONSET OF STRONGER WINDS OVER THE WATERS MON MORNING. ON THE OTHER
HAND...THE ARCTIC AIRMASS BEHIND THE COLD FRONT MAY PUSH THE FRONT
ACROSS THE WATERS A FEW HOURS FASTER THAN ANTICIPATED. SINCE
CURRENT FORECAST HAS WINDS INCREASING LATE IN THE THIRD PERIOD (OR
JUST INSIDE 36 HOURS)...HAVE OPTED NOT TO ISSUE SCA OR GALE
HEADLINES WITH THIS FORECAST ISSUANCE.
VERY STRONG CAA MOVES OVER THE WATERS MON EVENING/OVERNIGHT AS A
VERY COLD ARCTIC AIRMASS MOVES INTO THE MID ATLANTIC REGION BEHIND
THE DEPARTING FRONT. THE SFC PRESSURE GRADIENT IS EXTREMELY TIGHT
DUE TO THE VAST TEMPERATURE DIFFERENCES AHEAD OF AND BEHIND THE
ARCTIC FRONT. TAKING THIS INTO CONSIDERATION...THERE MAY BE A
PERIOD OF STRONGER WINDS (STILL GALE FORCE) WITH THE INITIAL COLD
AIR PUSH WHICH FORECAST MODELS ARE NOT PICKING UP ON ATTM. HAVE
MAINTAINED THE PREVIOUS FORECAST WIND STRENGTH THROUGH MON NIGHT...
WHICH WAS ALREADY HIGHER THAN MODEL GUIDANCE. HOWEVER THIS MAY
NEED TO BE INCREASED BY ANOTHER 5-10 KT ALL WATERS. BECAUSE WINDS
BACK FROM NW TO W MON NIGHT...THE WIND SHIFT MAY BE ENOUGH TO
HAMPER THE POTENTIAL FOR PROLONGED GALES VERSUS IF THE WINDS
STAYED NW-N DURING THE COLD AIR SURGE. W WINDS REMAIN STRONG
THROUGH TUE. THEN HIGH PRESSURE BUILDS INTO THE REGION FROM THE
WEST AND THE TEMP/PRESSURE GRADIENT BEGINS TO RELAX...THUS
ALLOWING WINDS TO SLOWLY DIMINISH DURING THE LATE AFTN/EVENING.
SEAS SHOULD FOLLOW THE SAME TREND DURING THIS TIME BUT SHOULD NOT
FALL BELOW 5 FT UNTIL CLOSER TO WED MORNING. HIGH PRESSURE CROSSES
THE WATERS WED/THU WITH MORE BENIGN CONDITIONS EXPECTED.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
ANZ658.
&&
$$
SYNOPSIS...ALB/BMD/JDM
NEAR TERM...ALB/JAB
SHORT TERM...ALB
LONG TERM...BMD
AVIATION...MPR
MARINE...BMD/MPR
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
519 PM EST SUN JAN 5 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 445 PM EST SUN JAN 5 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE CENTER OF AN ELONGATED
POLAR VORTEX OVER NRN ONTARIO. A SHORTWAVE WAS DIVING SE THRU THE
NRN PLAINS...CAUSING THE ELONGATION OF THE VORTEX INTO THE NRN
PLAINS. THE CORE OF THE VERY COLD ARCTIC AIR MASS RESIDES FROM NRN
ONTARIO INTO SCNTRL CANADA AND THE FAR NRN PLAINS. PER 12Z RAOBS...
850MB TEMPS ARE IN THE -29C TO -34C RANGE ACROSS SCNTRL CANADA INTO
THE FAR NCNTL CONUS. LATEST RUC ANALYSIS INDICATES 850MB TEMPS
RANGING FROM -25C OVER WRN LAKE SUPERIOR TO AROUND -19C OVER FAR SE
LAKE SUPERIOR. OF COURSE...THIS IS LEADING TO LES OFF LAKE SUPERIOR
IN WNW LOW-LEVEL FLOW. HOWEVER...VERY DRY AIR MASS/LOW INVERSION
(3-5KFT LOWEST W PER LATEST RUC) IS GREATLY LIMITING LES INTENSITY.
PLUS...IT DOESN`T HELP THAT VERY COLD AIR HAS ELIMINATED THE DGZ FOR
THE WRN LAKE SUPERIOR LES. ON THE OTHER HAND...THE RESULTING SMALL
SNOWFLAKES ARE LEADING TO SHARPLY REDUCED VIS WHERE LES IS OCCURRING
(VIS AT KCMX HAS BEEN DOWN TO 1/2SM AT TIMES THIS AFTN...AND WEBCAMS
HAVE SHOWN QUITE LOW VIS AT TIMES).
AS THE ELONGATED POLAR VORTEX SWINGS INTO THE UPPER GREAT LAKES
MON...THERE WILL BE A SIGNIFICANT LIFTING OF THE INVERSION AND
DEEPENING OF MOISTURE. THIS WILL GRADUALLY BEGIN TONIGHT...BUT WILL
LARGELY TAKE PLACE DURING THE DAY MON. AS A RESULT...THERE WILL BE A
NOTABLE INCREASE IN LAKE EFFECT SNOW COVERAGE...AND INTENSITY WILL
INCREASE AS WELL. HOWEVER...WITH THE COLD AIR MASS ELIMINATING THE
DGZ...SNOW-TO-WATER RATIOS WILL BE POOR...PROBABLY DOWN TOWARD 10 TO
1 AS HAS BEEN OBSERVED IN PAST ARCTIC AIR MASSES SIMILAR TO THE
MAGNITUDE OF THIS ONE. SNOW WILL BE POWDERY AND VERY EFFECTIVE AT
REDUCING VIS. WITH THE INCREASE IN LES COVERAGE...WHITEOUTS WILL
PROBABLY BECOME NEARLY CONSTANT IN THE SNOWBELTS FAVORED BY NW WINDS
LATE TONIGHT AND ESPECIALLY MON. TONIGHT...LOW-LEVEL WINDS WILL
VEER MORE TOWARD THE NNW IN RESPONSE TO THE DEEPENING LOW LIFTING
NNE THRU THE LWR LAKES. THE VEERING WILL BE MORE PRONOUNCED OVER THE
ERN LAKE WHERE LAND BREEZE ENHANCEMENT OFF ONTARIO WILL AID THE
VEERING. THIS WILL LEAD TO STRENGTHENING CONVERGENCE INTO
ALGER/LUCE/SCHOOLCRAFT COUNTIES. WITH THE DGZ STILL LINGERING IN THE
LOWER PART OF THE CONVECTIVE LAYER IN THAT AREA...SHOULD BE ABLE TO
GET ACCUMULATIONS INTO THE 2 TO 4 INCH RANGE. COMBINED WITH SOME
INCREASE IN WINDS TO GENERATE BLSN...ADVY LOOKS ON TRACK FOR THAT
AREA. EVEN THOUGH THE DGZ IS ELIMINATED MON...SIMILAR ACCUMULATIONS
SHOULD OCCUR GIVEN LINGERING ENHANCED CONVERGENCE AND DEEP MOISTURE
PROFILE. OUT W...SNOW ACCUMULATIONS WILL BE ON THE ORDER OF 1-2 TO
PERHAPS 3IN/12HR TONIGHT/MON.
AS FOR TEMPS/WIND CHILLS...WITH LOW-LEVEL WINDS VEERING TONIGHT...
THERE SHOULD BE AN INCREASE IN LAKE EFFECT CLOUD COVER ACROSS MUCH
OF THE AREA. HAVE THUS OPTED TO RAISE MINS A FEW DEGREES IN MANY
LOCATIONS. TEMPS MAY STILL BOTTOM OUT AROUND -25F OVER THE FAR W
ALONG THE MI/WI BORDER...BUT IF CLOUD COVER IS QUICKER TO DEVELOP
AND MORE PERSISTENT...TEMPS MAY NOT FALL THAT LOW. IN GENERAL...MOST
OF THE W HALF OF UPPER MI WILL SEE MINS IN THE -10F TO -20F RANGE
WITH WIND CHILLS FALLING TO -30 TO -45F. WITH THE CORE OF THE COLD
OVER THE AREA MON...EXPECT INTERIOR W LOCATIONS TO FAIL TO RISE
ABOVE -10F. ONLY AREAS TO GET JUST ABOVE 0F WILL BE OVER THE E.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 515 PM EST SUN JAN 5 2014
.MONDAY NIGHT INTO TUESDAY...W TO WNW LOW LEVEL WINDS WILL CONTINUE
BETWEEN LOW PRES LIFTING NNE INTO HUDSON BAY AND ARCTIC HIGH PRES
BUILDING FROM THE NRN PLAINS TO THE UPPER MS VALLEY. 850 MB TEMPS
WILL GRADUALLY MODERATE FROM THE -25C TO -30C RANGE TO -17C TO -22C
FROM 00Z/TUE TO 00Z/WED. HOWEVER...SFC TEMPS WILL CLIMB ONLY
SLIGHTLY. WINDS WILL ALSO DIMINISH TO AROUND 10 MPH BY TUE MORNING.
HOWEVER...WITH TEMPS AGAIN FALLING INTO THE -12 TO -25 RANGE...WIND
CHILL VALUES OF -30 TO -45 WILL REMAIN IN THE WARNING CATEGORY OVER
MOST OF THE CWA. LES WILL PERSIST FOR THE KEWEENAW AND THE NE CWA(E
OF MUNISING). THE HIGHER RES MODELS SUGGEST THAT LOW LEVEL CONV OVER
THE WRN LAKE MAY BOOST SNOWFALL RATES INTO THE KEWEENAW(NEAR OR JUST
SOUTH OF HOUGHTON) AND NEAR THE PICTURED ROCKS AND GRAND MARAIS.
HOWEVER...WITH THE VERY COLD AIR AND NO DGZ AVAILABLE...SLR VALUES
WILL REMAIN LOW AND LIMIT SNOW ACCUMULATIONS TO THE 1 TO 3 INCH PER
12 HOUR WEST AND POSSIBLY 2 TO 4 INCHES EAST.
TUE NIGHT AND WED...WRLY FLOW LES WILL CONTINUE AS THE AIRMASS
MODERATES. WITH THE DGZ MOVING BACK CLOSER TO THE CONVECTIVE
LAYER...SLR VALUES WILL INCREASE. HOWEVER...THE VERY AIR UPSTREAM
WILL REMAIN UNFAVORABLE FOR MORE SIGNIFICANT LES. SO...SNOWFALL RATES
WILL GENERALLY REMAIN LIGHT...IN THE 1 TO 3 INCH RANGE...WITH THE
GREATEST AMOUNTS REMAINING OVER THE KEWEENAW AND ALONG THE SHORELINE
NEAR GRAND MARAIS. WIND CHILLS WILL ALSO NOT BE AS SEVERE AS WINDS
DIMINISH CLOSER TO 5 MPH INLAND AS TEMPS DROP INTO THE -10 TO -20
RANGE GIVING WIND CHILL VALUES FROM -20 TO -30.
THU-SUN...THE MODELS SHOW A TRANSITION TO A MORE ZONAL PATTERN WITH
SEPARATED NRN AND SRN STREAMS. AFTER BACKING WINDS TO SW WILL END THE
LES OVER THE KEWEENAW THU...MAINLY DRY WEATHER IS EXPECTED INTO THE
WEEKEND WITH MUCH MILDER CONDITIONS. HIGH TEMPS SHOULD CLIMB BACK
INTO THE UPPER 20S FRI AND TO AROUND 30 FOR THE WEEKEND. ALTHOUGH THE
00Z/05 ECMWF RUN SHOWED A MORE PHASED TROUGH BY SUN THAT BRINGS UP
ENOUGH WARM AIR AND MOISTURE FOR RAIN...THE 12Z/05 RUN FLIPPED BACK
TO A MORE SEPARATE NRN STREAM WITH THE SRN SHRTWV SLIDING INTO THE
LOWER MS VALLEY SIMILAR TO THE GFS/GEFS. HOWEVER...CONFIDENCE IN ANY
WEATHER DETAILS BEYOND THE MILDER AIR FOR THE WEEKEND REMAINS LOW.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1217 PM EST SUN JAN 5 2014
WITH EXTREMELY COLD AIR FLOWING INTO THE UPPER LAKES OVER THE NEXT
COUPLE OF DAYS...LAKE EFFECT SNOW SHOWERS WILL BE THE RULE OFF LAKE
SUPERIOR IN AN OVERALL NW FLOW. WITH MIXED LAYER WINDS TENDING TO
VEER SLIGHTLY...-SHSN WILL BECOME INCREASINGLY PERSISTENT AT KIWD.
EXPECT A TREND TO PREVAILING IFR CONDITIONS THIS AFTN/EVENING. WITH
VERY COLD AIR MASS LEADING TO SMALL SNOWFLAKES THAT ARE HIGHLY
EFFECTIVE AT REDUCING VIS...IT`S CERTAINLY POSSIBLE KIWD MAY FALL
INTO A PREVAILING LIFR CONDITION. KCMX WILL REMAIN UNDER CONSTANT
LAKE EFFECT SNOW SHOWERS. DURING THE AFTN...EXPECT CONDITIONS TO
VARY BTWN LIFR AND IFR. AS SNOWFLAKES BECOME SMALLER AND WINDS
INCREASE LEADING TO BLSN...PREVAILING LIFR CONDITIONS WILL TAKE OVER
TONIGHT. AT SOME POINT...MOST LIKELY BY DAYBREAK...EXPECT CONDITIONS
TO BECOME PREVAILING VLIFR AT KCMX. CONDITIONS COULD THEN CERTAINLY
REMAIN VLIFR NEARLY CONTINUOUSLY THRU AT LEAST TUE MORNING. AT
KSAW...INITIALLY DRY AIR AND DOWNSLOPE NW FLOW WILL RESULT IN VFR
CONDITIONS FOR THE NEXT FEW HRS. LAKE EFFECT CLOUDS WILL ARRIVE
LATER THIS AFTN AS THE FLOW VEERS SLIGHTLY AND ALLOWS MORE LAKE
SUPERIOR MODIFIED...MOISTER AIR TO ARRIVE. ALTHOUGH THE LOW-LEVEL NW
WINDS WILL NOT BE IDEAL...THE ARRIVAL OF DEEPER MOISTURE WILL
RESULT IN -SHSN TONIGHT/MON MORNING ALONG WITH MORE SOLID MVFR
CONDITIONS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 515 PM EST SUN JAN 5 2014
PRES GRADIENT WILL SLOWLY INCREASE TONIGHT THRU MON...RESULTING IN
AN INCREASE IN WINDS. LOOKS LIKE 35KT GALES WILL DEVELOP OVER
PORTIONS OF ERN LAKE SUPERIOR LATE TONIGHT OR MON MORNING...AIDED BY
LAND BREEZE CONVERGENCE. AS PRES GRADIENT TIGHTENS A LITTLE MORE...
WILL NEED TO WATCH FOR AN EXPANSION OF GALES TO MORE OF CNTRL/ERN
LAKE SUPERIOR MON NIGHT/TUE. WITH VERY COLD AIR MASS OVER THE AREA
FOR THE NEXT COUPLE OF DAYS...WINDS/WAVES WILL LEAD TO HEAVY
FREEZING SPRAY OVER MUCH OF LAKE SUPERIOR. WINDS WILL DIMINISH
DURING THE MIDWEEK PERIOD AS THE COLD EASES AND HIGH PRES MOVES
ACROSS THE GREAT LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 11 AM EST /10 AM CST/ TUESDAY FOR
MIZ001>005-009>013-084.
WIND CHILL ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ002-009-010-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ006-007-
014-085.
WIND CHILL WARNING FROM 7 PM MONDAY TO 11 AM EST TUESDAY FOR
MIZ006-007-014-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WARNING FROM 7 AM MONDAY TO 1 AM EST WEDNESDAY FOR LSZ265-
266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...JLB
AVIATION...ROLFSON
MARINE...ROLFSON
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
446 PM EST SUN JAN 5 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 445 PM EST SUN JAN 5 2014
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW THE CENTER OF AN ELONGATED
POLAR VORTEX OVER NRN ONTARIO. A SHORTWAVE WAS DIVING SE THRU THE
NRN PLAINS...CAUSING THE ELONGATION OF THE VORTEX INTO THE NRN
PLAINS. THE CORE OF THE VERY COLD ARCTIC AIR MASS RESIDES FROM NRN
ONTARIO INTO SCNTRL CANADA AND THE FAR NRN PLAINS. PER 12Z RAOBS...
850MB TEMPS ARE IN THE -29C TO -34C RANGE ACROSS SCNTRL CANADA INTO
THE FAR NCNTL CONUS. LATEST RUC ANALYSIS INDICATES 850MB TEMPS
RANGING FROM -25C OVER WRN LAKE SUPERIOR TO AROUND -19C OVER FAR SE
LAKE SUPERIOR. OF COURSE...THIS IS LEADING TO LES OFF LAKE SUPERIOR
IN WNW LOW-LEVEL FLOW. HOWEVER...VERY DRY AIR MASS/LOW INVERSION
(3-5KFT LOWEST W PER LATEST RUC) IS GREATLY LIMITING LES INTENSITY.
PLUS...IT DOESN`T HELP THAT VERY COLD AIR HAS ELIMINATED THE DGZ FOR
THE WRN LAKE SUPERIOR LES. ON THE OTHER HAND...THE RESULTING SMALL
SNOWFLAKES ARE LEADING TO SHARPLY REDUCED VIS WHERE LES IS OCCURRING
(VIS AT KCMX HAS BEEN DOWN TO 1/2SM AT TIMES THIS AFTN...AND WEBCAMS
HAVE SHOWN QUITE LOW VIS AT TIMES).
AS THE ELONGATED POLAR VORTEX SWINGS INTO THE UPPER GREAT LAKES
MON...THERE WILL BE A SIGNIFICANT LIFTING OF THE INVERSION AND
DEEPENING OF MOISTURE. THIS WILL GRADUALLY BEGIN TONIGHT...BUT WILL
LARGELY TAKE PLACE DURING THE DAY MON. AS A RESULT...THERE WILL BE A
NOTABLE INCREASE IN LAKE EFFECT SNOW COVERAGE...AND INTENSITY WILL
INCREASE AS WELL. HOWEVER...WITH THE COLD AIR MASS ELIMINATING THE
DGZ...SNOW-TO-WATER RATIOS WILL BE POOR...PROBABLY DOWN TOWARD 10 TO
1 AS HAS BEEN OBSERVED IN PAST ARCTIC AIR MASSES SIMILAR TO THE
MAGNITUDE OF THIS ONE. SNOW WILL BE POWDERY AND VERY EFFECTIVE AT
REDUCING VIS. WITH THE INCREASE IN LES COVERAGE...WHITEOUTS WILL
PROBABLY BECOME NEARLY CONSTANT IN THE SNOWBELTS FAVORED BY NW WINDS
LATE TONIGHT AND ESPECIALLY MON. TONIGHT...LOW-LEVEL WINDS WILL
VEER MORE TOWARD THE NNW IN RESPONSE TO THE DEEPENING LOW LIFTING
NNE THRU THE LWR LAKES. THE VEERING WILL BE MORE PRONOUNCED OVER THE
ERN LAKE WHERE LAND BREEZE ENHANCEMENT OFF ONTARIO WILL AID THE
VEERING. THIS WILL LEAD TO STRENGTHENING CONVERGENCE INTO
ALGER/LUCE/SCHOOLCRAFT COUNTIES. WITH THE DGZ STILL LINGERING IN THE
LOWER PART OF THE CONVECTIVE LAYER IN THAT AREA...SHOULD BE ABLE TO
GET ACCUMULATIONS INTO THE 2 TO 4 INCH RANGE. COMBINED WITH SOME
INCREASE IN WINDS TO GENERATE BLSN...ADVY LOOKS ON TRACK FOR THAT
AREA. EVEN THOUGH THE DGZ IS ELIMINATED MON...SIMILAR ACCUMULATIONS
SHOULD OCCUR GIVEN LINGERING ENHANCED CONVERGENCE AND DEEP MOISTURE
PROFILE. OUT W...SNOW ACCUMULATIONS WILL BE ON THE ORDER OF 1-2 TO
PERHAPS 3IN/12HR TONIGHT/MON.
AS FOR TEMPS/WIND CHILLS...WITH LOW-LEVEL WINDS VEERING TONIGHT...
THERE SHOULD BE AN INCREASE IN LAKE EFFECT CLOUD COVER ACROSS MUCH
OF THE AREA. HAVE THUS OPTED TO RAISE MINS A FEW DEGREES IN MANY
LOCATIONS. TEMPS MAY STILL BOTTOM OUT AROUND -25F OVER THE FAR W
ALONG THE MI/WI BORDER...BUT IF CLOUD COVER IS QUICKER TO DEVELOP
AND MORE PERSISTENT...TEMPS MAY NOT FALL THAT LOW. IN GENERAL...MOST
OF THE W HALF OF UPPER MI WILL SEE MINS IN THE -10F TO -20F RANGE
WITH WIND CHILLS FALLING TO -30 TO -45F. WITH THE CORE OF THE COLD
OVER THE AREA MON...EXPECT INTERIOR W LOCATIONS TO FAIL TO RISE
ABOVE -10F. ONLY AREAS TO GET JUST ABOVE 0F WILL BE OVER THE E.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 448 AM EST SUN JAN 5 2014
THE MAIN CONCERN FOR THE LONG TERM FORECAST WILL BE EXTREMELY COLD
TEMPERATURES/WIND CHILLS AND REDUCED VISIBILITIES FROM LAKE EFFECT
SNOW SHOWERS AND BLOWING SNOW.
LOW PRESSURE TRAVELING FROM THE OHIO VALLEY TODAY WILL REACH QUEBEC
BY MONDAY MORNING. MEANWHILE...A COLD ARCTIC AIRMASS/HIGH PRESSURE
WILL SINK FROM THE CANADIAN PRAIRIE INTO THE MIDWEST AND CENTRAL
PLAINS. AS THIS HIGH SINKS TOWARDS THE GULF COAST MONDAY NIGHT...THE
LOW OVER QUEBEC WILL DRIFT WESTWARD INTO JAMES BAY. THIS PATTERN
WILL KEEP UPPER MICHIGAN IN A MODERATE WEST-NORTHWESTERLY FLOW
THROUGH WEDNESDAY...AS A TIGHTER PRESSURE GRADIENT SITS OVER THE
AREA. ADDITIONALLY...A 500MB LOW WILL CENTER ITSELF OVER UPPER MI
MONDAY MORNING...THEN DRIFT SLOWLY NORTHEASTWARD INTO ONTARIO AND
QUEBEC. WITH THE LOW CENTERED OVER UPPER MI 850-500MB QVECTOR
CONVERGENCE IS MAXIMIZED OVER THE EASTERN U.P. AND LOWER MI. WITH
NORTHWESTERLY WINDS MOVING THE COLD ARCTIC AIR OVER LAKE
SUPERIOR...KEPT POPS IN NORTHWEST WIND FAVORED SNOWBELTS. ALSO
INCREASED POPS IN THE EASTERN CWA AS THE UPPER LEVEL SUPPORT CROSSES
THROUGH THE AREA WITH THE TROUGH.
WINDS GENERALLY REMAIN NORTHWESTERLY THROUGH MONDAY AFTERNOON...THEN
BEGIN TO BACK TOWARDS THE WEST-NORTHWEST WIND DIRECTION. ADJUSTED
POPS ACCORDINGLY...WITH THE MAIN CORE OF PRECIPITATION IN THE
EASTERN U.P. SHIFTING TO AREAS FAVORED BY WNW WINDS...MAINLY EAST OF
MUNISING. ON TUESDAY SEVERAL SMALL SHORTWAVES SNEAK ALONG THE BASE
OF THE TROUGH ALOFT AS IT MOVES EASTWARD...AND WNW WINDS BECOME MORE
WESTERLY TOWARDS THE EVENING. MOST OF THE SNOW BY LATE TUESDAY
AFTERNOON WILL BE OVER THE KEWEENAW AND EAST OF GRAND MARAIS.
LIMITING FACTORS TO SIGNIFICANT ACCUMULATIONS WILL BE THE EXTREMELY
COLD/DRY AIRMASS. THIS SENDS THE DGZ CRASHING INTO THE GROUND FOR
MOST LOCATIONS...ESPECIALLY MONDAY NIGHT INTO TUESDAY AFTERNOON. AS
A RESULT SNOW RATIOS WILL BE ON THE ORDER OF 15-18:1 AND FLAKES VERY
FINE. AS FAR AS MOISTURE GOES...PWATS DURING THIS TIME FRAME DROP TO
NEAR 15 PERCENT OF NORMAL FOR UPPER MI. OVERALL...FROM MONDAY
MORNING THROUGH TUESDAY MORNING...HAVE 2-4 INCHES FOR AREAS FAVORED
BY WEST-NORTHWEST WINDS. TUESDAY MORNING INTO WED MORNING ONLY HAVE
1-3 INCHES FOR THE SAME AREAS...MAINLY THE KEWEENAW AND EAST OF
MUNISING NEAR LAKE SUPERIOR.
THE COLD ARCTIC AIRMASS WILL BRING LOW TEMPERATURES CRASHING DOWN TO
-27F OUT WEST...AND THE TEENS BELOW ZERO EAST FOR MONDAY NIGHT.
AREAS NEAR THE LAKE WILL SEE TEMPERATURES DROP DOWN TO THE SINGLE
DIGITS BELOW ZERO FARTHER EAST AND OVER THE KEWEENAW. WITH THE
STRONGER WINDS OVER THE AREA HOWEVER...WIND CHILLS WILL DROP AS LOW
AS -50F ACROSS THE WEST...AND MAINLY THE -30S AND -40S
ELSEWHERE...EVEN NEAR THE LAKE.
THOUGH SNOW ACCUMULATIONS WILL NOT BE HAZARDOUS BY THEMSELVES...THE
COMBINATION OF SNOW...BLOWING SNOW...AND DANGEROUSLY LOW
TEMPERATURES/WIND CHILLS WARRANT A LAKE EFFECT SNOW ADVISORY FOR
AREAS IN THE EAST...MAINLY FOR ALGER/LUCE/SCHOOLCRAFT COUNTIES. WIND
CHILLS WILL REACH ADVISORY CRITERIA...AND THE COMBINATION OF SNOW
AND BLOWING SNOW/DUE TO WINDS AROUND 30 MPH/ WILL REDUCE
VISIBILITIES DRAMATICALLY...ESPECIALLY WITH THE FINER FLAKES.
ELSEWHERE...HAVE ONLY THE WIND CHILL WARNING IN EFFECT FOR THE
MONDAY-TUESDAY TIME FRAME. THE KEWEENAW WILL ALSO SEE STRONG
WINDS...GUSTING TO 25 TO 30 MPH...AND PERSISTENT LAKE EFFECT SNOW
WITH AREAS OF BLOWING SNOW DURING THE MONDAY-TUESDAY TIME FRAME.
HAVE INCLUDED THIS WORDING IN THE WIND CHILL WARNING FOR THE
KEWEENAW/HOUGHTON COUNTIES FOR SIMPLICITY WITH HEADLINES.
WINDS WILL GRADUALLY DIE DOWN FROM WEDNESDAY INTO THURSDAY AS THE
HIGH CENTERS ITSELF OVER THE GREAT LAKES. LIGHT AND VARIABLE WINDS
WILL GRADUALLY TRANSITION TO MORE MODERATE SOUTH TO SOUTHWESTERLY
WINDS AS THE HIGH SHIFTS EASTWARD TOWARDS THE NEW ENGLAND
STATES...AND LOW PRESSURE MOVES INTO NORTHERN MANITOBA. SOME OF THE
MODELS ATTEMPT TO BRING A WEAK SHORTWAVE TROUGH INTO THE MIDWEST
LATE FRIDAY AFTERNOON AND SATURDAY...BUT OTHERS KEEP MORE ZONAL FLOW
OVER THE AREA. WILL KEEP THE CONSENSUS POPS DURING THIS TIME FRAME
HOWEVER...WITH THE WNW-LAKE EFFECT MOVING OUT INTO THE LAKE AS WINDS
BACK TO THE SOUTH-SOUTHWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1217 PM EST SUN JAN 5 2014
WITH EXTREMELY COLD AIR FLOWING INTO THE UPPER LAKES OVER THE NEXT
COUPLE OF DAYS...LAKE EFFECT SNOW SHOWERS WILL BE THE RULE OFF LAKE
SUPERIOR IN AN OVERALL NW FLOW. WITH MIXED LAYER WINDS TENDING TO
VEER SLIGHTLY...-SHSN WILL BECOME INCREASINGLY PERSISTENT AT KIWD.
EXPECT A TREND TO PREVAILING IFR CONDITIONS THIS AFTN/EVENING. WITH
VERY COLD AIR MASS LEADING TO SMALL SNOWFLAKES THAT ARE HIGHLY
EFFECTIVE AT REDUCING VIS...IT`S CERTAINLY POSSIBLE KIWD MAY FALL
INTO A PREVAILING LIFR CONDITION. KCMX WILL REMAIN UNDER CONSTANT
LAKE EFFECT SNOW SHOWERS. DURING THE AFTN...EXPECT CONDITIONS TO
VARY BTWN LIFR AND IFR. AS SNOWFLAKES BECOME SMALLER AND WINDS
INCREASE LEADING TO BLSN...PREVAILING LIFR CONDITIONS WILL TAKE OVER
TONIGHT. AT SOME POINT...MOST LIKELY BY DAYBREAK...EXPECT CONDITIONS
TO BECOME PREVAILING VLIFR AT KCMX. CONDITIONS COULD THEN CERTAINLY
REMAIN VLIFR NEARLY CONTINUOUSLY THRU AT LEAST TUE MORNING. AT
KSAW...INITIALLY DRY AIR AND DOWNSLOPE NW FLOW WILL RESULT IN VFR
CONDITIONS FOR THE NEXT FEW HRS. LAKE EFFECT CLOUDS WILL ARRIVE
LATER THIS AFTN AS THE FLOW VEERS SLIGHTLY AND ALLOWS MORE LAKE
SUPERIOR MODIFIED...MOISTER AIR TO ARRIVE. ALTHOUGH THE LOW-LEVEL NW
WINDS WILL NOT BE IDEAL...THE ARRIVAL OF DEEPER MOISTURE WILL
RESULT IN -SHSN TONIGHT/MON MORNING ALONG WITH MORE SOLID MVFR
CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST SUN JAN 5 2014
A GALE WATCH IS IN EFFECT FOR CENTRAL AND EASTERN LAKE SUPERIOR
MONDAY MORNING THROUGH TUESDAY NIGHT...AND A HEAVY FREEZING SPRAY
WARNING REMAINS IN EFFECT...
EXPECT NW WINDS 20-25 KTS THIS MORNING TO INCREASE TO 25-30 KTS
LATER TODAY AND TONIGHT AS THE PRES GRADIENT OVER THE UPPER GREAT
LAKES SHARPENS TO THE NW OF A DEEPENING LO PRES MOVING NE THRU THE
SE GREAT LAKES INTO SE CANADA. THERE MAY BE A FEW GALE FORCE GUSTS
OVER PORTIONS OF THE E LAKE LATE TONIGHT AS WELL. WITH ARCTIC AIR
PERSISTING OVER THE AREA...EXPECT PERIODS OF HEAVY FREEZING SPRAY...
ESPECIALLY OVER THE E HALF WHERE WINDS WILL BE STRONGEST.
LAKE SUPERIOR WILL BE CAUGHT THIS TIGHT PRESSURE GRADIENT BETWEEN
STRONG ARCTIC HIGH PRESSURE OVER THE PLAINS AND STRONG LOW PRESSURE
OVER QUEBEC MONDAY INTO TUESDAY. AS A RESULT...WEST NORTHWEST GALES
TO 35 KNOTS WILL OCCUR OVER MAINLY CENTRAL AND EASTERN LAKE SUPERIOR
ON MONDAY AFTERNOON...AND WEST NORTHWEST GALES TO 40 KNOTS WILL
OCCUR ON TUESDAY AFTERNOON. WINDS ON WESTERN LAKE SUPERIOR WILL
LARGELY REMAIN WEST-NORTHWEST AT 20 TO 30 KNOTS DURING THIS TIME.
ADDITIONALLY...COLD ARCTIC AIR IN PLACE OVER LAKE SUPERIOR COMBINED
WITH THE STRONG WINDS WILL LEAD TO HEAVY FREEZING SPRAY FOR ALL OF
THE LAKE THROUGH WEDNESDAY MORNING. ON WEDNESDAY AND THURSDAY HIGH
PRESSURE WILL MAKE ITS WAY NORTHWARD...CENTERING ITSELF OVER THE
GREAT LAKES. AS A RESULT...GUSTY WEST NORTHWEST WINDS WILL DIE
DOWN...EVENTUALLY BACKING SOUTHWEST AT LESS THAN 10 KNOTS BY
THURSDAY. AS THE HIGH SHIFTS TO THE NEW ENGLAND STATES AND LOW
PRESSURE MOVES INTO NORTHERN MANITOBA FRIDAY AFTERNOON AND
SATURDAY...SOUTHWESTERLY WINDS WILL PICK UP TO 15 TO 25 KNOTS OVER
ALL OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 11 AM EST /10 AM CST/ TUESDAY FOR
MIZ001>005-009>013-084.
WIND CHILL ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ002-009-010-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST MONDAY FOR MIZ006-007-
014-085.
WIND CHILL WARNING FROM 7 PM MONDAY TO 11 AM EST TUESDAY FOR
MIZ006-007-014-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WARNING FROM 7 AM MONDAY TO 1 AM EST WEDNESDAY FOR LSZ265-
266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...MCD
AVIATION...ROLFSON
MARINE...KC/MCD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1218 PM EST SUN JAN 5 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST SUN JAN 5 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP POLAR VORTEX
CENTERED OVER SCENTRAL CANADA...WITH CORE OF ARCTIC AIRMASS
ACCOMPANIED BY 00Z H5/H85/H925 TEMPS AS LO AS -43C/-31C/-34C AT THE
PAS MANITOBA. UPR MI IS ON THE PERIPHERY OF THE VERY COLD AIRMASS
ATTM...WITH 00Z H85 TEMPS RANGING FM -6C AT GRB TO -24C AT INL. LVL
WNW FLOW TO THE E OF SFC HI PRES IN THE NRN PLAINS IS ADVECTING THE
COLDER AIR INTO UPR MI...BUT RELATIVELY LIGHT WINDS HAVE SLOWED THE
ADVECTION. THIS COLD FLOW OVER THE RELATIVELY WARM WATERS OF LK SUP
IS CAUSING THE TYPICAL LK CLDS/LES IN THE FAVORED SN BELTS...BUT LO
INVRN BASE ARND H9 AS SHOWN ON THE 00Z INL/GRB RAOBS AS WELL AS DRY
NATURE OF THE LLVLS IS LIMITING THE INTENSITY OF THE SHSN. OTRW...
QUITE A BIT OF HI CLD IS STREAMING OVER MAINLY THE SE HALF OF THE
CWA WELL TO THE N OF SFC LO PRES DVLPG IN THE LOWER MS RIVER VALLEY.
MAIN FCST CONCERNS THRU THE SHORT TERM FOCUS ON TEMPS/WIND CHILLS/
GOING HEADLINES AS WELL AS LES/BLSN.
TODAY...THE CORE OF THE ARCTIC AIR OVER SCENTRAL CANADA EARLY THIS
MRNG IS FCST TO DROP OVER MN BY 00Z MON. AS THE TROF OVER CENTRAL
NAMERICA DEEPENS...THE SFC LO NOW OVER THE LOWER MS RIVER VALLEY IS
PROGGED TO DEEPEN AND MOVE INTO THE OH RIVER VALLEY. ALTHOUGH THE
LARGER SCALE FORCING/ASCENT/DEEP MOISTENING ASSOCIATED WITH THIS LO
WL REMAIN TO THE E-SE OF UPR MI...THE PRES GRADIENT/LLVL NW FLOW
OVER THE AREA IS FCST TO SHARPEN AND INCRS THE ADVECTION OF THE
COLDER AIR INTO THE CWA. MODEL CONSENSUS SHOWS H85 TEMPS FALLING FM
-23C OVER THE NW/-14C OVER THE SE AT 12Z TO -29C OVER THE NW/-19C
OVER THE SE BY 00Z MON. AS A RESULT...THE DIURNAL TEMP RECOVERY...
ESPECIALLY OVER THE WRN ZNS...WL BE NEGLIGIBLE. ALTHOUGH THE SURGE
OF LLVL COLD AIR WL SUPPORT ONGOING LES...THE LO INVRN BASES ARND
3-4K FT AND ACYC NATURE OF THE H925 FLOW/GENERAL SUBSIDENCE WL LIMIT
SN AMOUNTS...ESPECIALLY OVER THE W WHERE THE DGZ WL DESCEND INTO THE
GROUND AND LIMIT SN GROWTH. THERE MAY BE AN UPTICK IN THE LES IN THE
NW WIND SN BELTS E OF MQT LATER IN THE DAY HOWEVER AS LLVL CNVGC ON
LK INDUCED TROF SHARPENS UNDER DEEPENING UPR TROF. AS FOR GOING WIND
CHILL HEADLINES...OPTED TO DROP BARAGA...MARQUETTE AND DICKINSON
COUNTIES FM THE HEADLINE GIVEN CURRENT CONDITIONS AND EXPECTATION
THAT THESE AREAS WL NOT MEET CRITERIA MOST OF THE THE DAY.
TONIGHT...THE LO TO THE SE IS PROGGED TO DEEPEN SGNFTLY AND LIFT
NEWD INTO SE CANADA AS THE CENTRAL CONUS TROF SHARPENS WITH MORE
PHASING OF THE ARCTIC AND POLAR BRANCHES. THE CORE OF THE COLDEST
AIR...WITH H85 TEMPS DOWN TO -33C TO -35C...IS PROGGED TO SHIFT OVER
WI. AS THE LO DEEPENS...THE PRES GRADIENT WL SHARPEN FURTHER OVER
THE UPR LKS...ALLOWING H925 NW WINDS TO INCRS TO 25 TO 30 KTS. THE
STRENGTHENING WINDS AND FALLING TEMPS SUPPORT GOING WIND CHILL WRNGS
AWAY FM THE LK MODERATION THAT WL IMPACT MAINLY THE ERN CWA EVEN
THOUGH A MORE N WIND COMPONENT OFF LK SUP MIGHT NOT ALLOW TEMPS TO
FALL AS LO AS PREVIOUS FCST. BUT OVER THE ERN CWA...THE ARRIVAL OF
DEEPER MSTR ASSOCIATED WITH ARRIVAL OF DEEP LYR QVECTOR CNVGC UNDER
THE FALLING HGTS ASSOCIATED WITH THE DEEPENING UPR TROF AS WELL AS
INCRSG LLVL CNVGC ACCOMPANYING THE SHARPENING OF THE LK INDUCED SFC
TROF WL GIVE A BOOST TO THE LES. WITH MORE FVRBL SN GROWTH...H85
TEMPS ARE PROGGED TO FALL TO ARND -24C HERE BY 12Z MON...AS WELL AS
INCRSG BLSN...OPTED TO REPLACE THE WIND CHILL ADVY FOR ALGER/LUCE/
SCHOOLCRAFT COUNTIES WITH A LK EFFECT SN ADVY TO ACCOUNT FOR SN FALL
AT LEAST APRCHG ADVY AMOUNTS...BLSN AND WIND CHILLS AT LEAST APRCHG
ADVY CRITERIA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 448 AM EST SUN JAN 5 2014
THE MAIN CONCERN FOR THE LONG TERM FORECAST WILL BE EXTREMELY COLD
TEMPERATURES/WIND CHILLS AND REDUCED VISIBILITIES FROM LAKE EFFECT
SNOW SHOWERS AND BLOWING SNOW.
LOW PRESSURE TRAVELING FROM THE OHIO VALLEY TODAY WILL REACH QUEBEC
BY MONDAY MORNING. MEANWHILE...A COLD ARCTIC AIRMASS/HIGH PRESSURE
WILL SINK FROM THE CANADIAN PRAIRIE INTO THE MIDWEST AND CENTRAL
PLAINS. AS THIS HIGH SINKS TOWARDS THE GULF COAST MONDAY NIGHT...THE
LOW OVER QUEBEC WILL DRIFT WESTWARD INTO JAMES BAY. THIS PATTERN
WILL KEEP UPPER MICHIGAN IN A MODERATE WEST-NORTHWESTERLY FLOW
THROUGH WEDNESDAY...AS A TIGHTER PRESSURE GRADIENT SITS OVER THE
AREA. ADDITIONALLY...A 500MB LOW WILL CENTER ITSELF OVER UPPER MI
MONDAY MORNING...THEN DRIFT SLOWLY NORTHEASTWARD INTO ONTARIO AND
QUEBEC. WITH THE LOW CENTERED OVER UPPER MI 850-500MB QVECTOR
CONVERGENCE IS MAXIMIZED OVER THE EASTERN U.P. AND LOWER MI. WITH
NORTHWESTERLY WINDS MOVING THE COLD ARCTIC AIR OVER LAKE
SUPERIOR...KEPT POPS IN NORTHWEST WIND FAVORED SNOWBELTS. ALSO
INCREASED POPS IN THE EASTERN CWA AS THE UPPER LEVEL SUPPORT CROSSES
THROUGH THE AREA WITH THE TROUGH.
WINDS GENERALLY REMAIN NORTHWESTERLY THROUGH MONDAY AFTERNOON...THEN
BEGIN TO BACK TOWARDS THE WEST-NORTHWEST WIND DIRECTION. ADJUSTED
POPS ACCORDINGLY...WITH THE MAIN CORE OF PRECIPITATION IN THE
EASTERN U.P. SHIFTING TO AREAS FAVORED BY WNW WINDS...MAINLY EAST OF
MUNISING. ON TUESDAY SEVERAL SMALL SHORTWAVES SNEAK ALONG THE BASE
OF THE TROUGH ALOFT AS IT MOVES EASTWARD...AND WNW WINDS BECOME MORE
WESTERLY TOWARDS THE EVENING. MOST OF THE SNOW BY LATE TUESDAY
AFTERNOON WILL BE OVER THE KEWEENAW AND EAST OF GRAND MARAIS.
LIMITING FACTORS TO SIGNIFICANT ACCUMULATIONS WILL BE THE EXTREMELY
COLD/DRY AIRMASS. THIS SENDS THE DGZ CRASHING INTO THE GROUND FOR
MOST LOCATIONS...ESPECIALLY MONDAY NIGHT INTO TUESDAY AFTERNOON. AS
A RESULT SNOW RATIOS WILL BE ON THE ORDER OF 15-18:1 AND FLAKES VERY
FINE. AS FAR AS MOISTURE GOES...PWATS DURING THIS TIME FRAME DROP TO
NEAR 15 PERCENT OF NORMAL FOR UPPER MI. OVERALL...FROM MONDAY
MORNING THROUGH TUESDAY MORNING...HAVE 2-4 INCHES FOR AREAS FAVORED
BY WEST-NORTHWEST WINDS. TUESDAY MORNING INTO WED MORNING ONLY HAVE
1-3 INCHES FOR THE SAME AREAS...MAINLY THE KEWEENAW AND EAST OF
MUNISING NEAR LAKE SUPERIOR.
THE COLD ARCTIC AIRMASS WILL BRING LOW TEMPERATURES CRASHING DOWN TO
-27F OUT WEST...AND THE TEENS BELOW ZERO EAST FOR MONDAY NIGHT.
AREAS NEAR THE LAKE WILL SEE TEMPERATURES DROP DOWN TO THE SINGLE
DIGITS BELOW ZERO FARTHER EAST AND OVER THE KEWEENAW. WITH THE
STRONGER WINDS OVER THE AREA HOWEVER...WIND CHILLS WILL DROP AS LOW
AS -50F ACROSS THE WEST...AND MAINLY THE -30S AND -40S
ELSEWHERE...EVEN NEAR THE LAKE.
THOUGH SNOW ACCUMULATIONS WILL NOT BE HAZARDOUS BY THEMSELVES...THE
COMBINATION OF SNOW...BLOWING SNOW...AND DANGEROUSLY LOW
TEMPERATURES/WIND CHILLS WARRANT A LAKE EFFECT SNOW ADVISORY FOR
AREAS IN THE EAST...MAINLY FOR ALGER/LUCE/SCHOOLCRAFT COUNTIES. WIND
CHILLS WILL REACH ADVISORY CRITERIA...AND THE COMBINATION OF SNOW
AND BLOWING SNOW/DUE TO WINDS AROUND 30 MPH/ WILL REDUCE
VISIBILITIES DRAMATICALLY...ESPECIALLY WITH THE FINER FLAKES.
ELSEWHERE...HAVE ONLY THE WIND CHILL WARNING IN EFFECT FOR THE
MONDAY-TUESDAY TIME FRAME. THE KEWEENAW WILL ALSO SEE STRONG
WINDS...GUSTING TO 25 TO 30 MPH...AND PERSISTENT LAKE EFFECT SNOW
WITH AREAS OF BLOWING SNOW DURING THE MONDAY-TUESDAY TIME FRAME.
HAVE INCLUDED THIS WORDING IN THE WIND CHILL WARNING FOR THE
KEWEENAW/HOUGHTON COUNTIES FOR SIMPLICITY WITH HEADLINES.
WINDS WILL GRADUALLY DIE DOWN FROM WEDNESDAY INTO THURSDAY AS THE
HIGH CENTERS ITSELF OVER THE GREAT LAKES. LIGHT AND VARIABLE WINDS
WILL GRADUALLY TRANSITION TO MORE MODERATE SOUTH TO SOUTHWESTERLY
WINDS AS THE HIGH SHIFTS EASTWARD TOWARDS THE NEW ENGLAND
STATES...AND LOW PRESSURE MOVES INTO NORTHERN MANITOBA. SOME OF THE
MODELS ATTEMPT TO BRING A WEAK SHORTWAVE TROUGH INTO THE MIDWEST
LATE FRIDAY AFTERNOON AND SATURDAY...BUT OTHERS KEEP MORE ZONAL FLOW
OVER THE AREA. WILL KEEP THE CONSENSUS POPS DURING THIS TIME FRAME
HOWEVER...WITH THE WNW-LAKE EFFECT MOVING OUT INTO THE LAKE AS WINDS
BACK TO THE SOUTH-SOUTHWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1217 PM EST SUN JAN 5 2014
WITH EXTREMELY COLD AIR FLOWING INTO THE UPPER LAKES OVER THE NEXT
COUPLE OF DAYS...LAKE EFFECT SNOW SHOWERS WILL BE THE RULE OFF LAKE
SUPERIOR IN AN OVERALL NW FLOW. WITH MIXED LAYER WINDS TENDING TO
VEER SLIGHTLY...-SHSN WILL BECOME INCREASINGLY PERSISTENT AT KIWD.
EXPECT A TREND TO PREVAILING IFR CONDITIONS THIS AFTN/EVENING. WITH
VERY COLD AIR MASS LEADING TO SMALL SNOWFLAKES THAT ARE HIGHLY
EFFECTIVE AT REDUCING VIS...IT`S CERTAINLY POSSIBLE KIWD MAY FALL
INTO A PREVAILING LIFR CONDITION. KCMX WILL REMAIN UNDER CONSTANT
LAKE EFFECT SNOW SHOWERS. DURING THE AFTN...EXPECT CONDITIONS TO
VARY BTWN LIFR AND IFR. AS SNOWFLAKES BECOME SMALLER AND WINDS
INCREASE LEADING TO BLSN...PREVAILING LIFR CONDITIONS WILL TAKE OVER
TONIGHT. AT SOME POINT...MOST LIKELY BY DAYBREAK...EXPECT CONDITIONS
TO BECOME PREVAILING VLIFR AT KCMX. CONDITIONS COULD THEN CERTAINLY
REMAIN VLIFR NEARLY CONTINUOUSLY THRU AT LEAST TUE MORNING. AT
KSAW...INITIALLY DRY AIR AND DOWNSLOPE NW FLOW WILL RESULT IN VFR
CONDITIONS FOR THE NEXT FEW HRS. LAKE EFFECT CLOUDS WILL ARRIVE
LATER THIS AFTN AS THE FLOW VEERS SLIGHTLY AND ALLOWS MORE LAKE
SUPERIOR MODIFIED...MOISTER AIR TO ARRIVE. ALTHOUGH THE LOW-LEVEL NW
WINDS WILL NOT BE IDEAL...THE ARRIVAL OF DEEPER MOISTURE WILL
RESULT IN -SHSN TONIGHT/MON MORNING ALONG WITH MORE SOLID MVFR
CONDITIONS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST SUN JAN 5 2014
A GALE WATCH IS IN EFFECT FOR CENTRAL AND EASTERN LAKE SUPERIOR
MONDAY MORNING THROUGH TUESDAY NIGHT...AND A HEAVY FREEZING SPRAY
WARNING REMAINS IN EFFECT...
EXPECT NW WINDS 20-25 KTS THIS MORNING TO INCREASE TO 25-30 KTS
LATER TODAY AND TONIGHT AS THE PRES GRADIENT OVER THE UPPER GREAT
LAKES SHARPENS TO THE NW OF A DEEPENING LO PRES MOVING NE THRU THE
SE GREAT LAKES INTO SE CANADA. THERE MAY BE A FEW GALE FORCE GUSTS
OVER PORTIONS OF THE E LAKE LATE TONIGHT AS WELL. WITH ARCTIC AIR
PERSISTING OVER THE AREA...EXPECT PERIODS OF HEAVY FREEZING SPRAY...
ESPECIALLY OVER THE E HALF WHERE WINDS WILL BE STRONGEST.
LAKE SUPERIOR WILL BE CAUGHT THIS TIGHT PRESSURE GRADIENT BETWEEN
STRONG ARCTIC HIGH PRESSURE OVER THE PLAINS AND STRONG LOW PRESSURE
OVER QUEBEC MONDAY INTO TUESDAY. AS A RESULT...WEST NORTHWEST GALES
TO 35 KNOTS WILL OCCUR OVER MAINLY CENTRAL AND EASTERN LAKE SUPERIOR
ON MONDAY AFTERNOON...AND WEST NORTHWEST GALES TO 40 KNOTS WILL
OCCUR ON TUESDAY AFTERNOON. WINDS ON WESTERN LAKE SUPERIOR WILL
LARGELY REMAIN WEST-NORTHWEST AT 20 TO 30 KNOTS DURING THIS TIME.
ADDITIONALLY...COLD ARCTIC AIR IN PLACE OVER LAKE SUPERIOR COMBINED
WITH THE STRONG WINDS WILL LEAD TO HEAVY FREEZING SPRAY FOR ALL OF
THE LAKE THROUGH WEDNESDAY MORNING. ON WEDNESDAY AND THURSDAY HIGH
PRESSURE WILL MAKE ITS WAY NORTHWARD...CENTERING ITSELF OVER THE
GREAT LAKES. AS A RESULT...GUSTY WEST NORTHWEST WINDS WILL DIE
DOWN...EVENTUALLY BACKING SOUTHWEST AT LESS THAN 10 KNOTS BY
THURSDAY. AS THE HIGH SHIFTS TO THE NEW ENGLAND STATES AND LOW
PRESSURE MOVES INTO NORTHERN MANITOBA FRIDAY AFTERNOON AND
SATURDAY...SOUTHWESTERLY WINDS WILL PICK UP TO 15 TO 25 KNOTS OVER
ALL OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 11
AM EST /10 AM CST/ TUESDAY FOR MIZ001>005-009>013-084.
WIND CHILL ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ002-009-010-084.
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
MONDAY FOR MIZ006-007-014-085.
WIND CHILL WARNING FROM 7 PM MONDAY TO 11 AM EST TUESDAY FOR
MIZ006-007-014-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WATCH FROM MONDAY MORNING THROUGH LATE TUESDAY NIGHT FOR
LSZ243>245-264>266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MCD
AVIATION...ROLFSON
MARINE...KC/MCD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
633 AM EST SUN JAN 5 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST SUN JAN 5 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP POLAR VORTEX
CENTERED OVER SCENTRAL CANADA...WITH CORE OF ARCTIC AIRMASS
ACCOMPANIED BY 00Z H5/H85/H925 TEMPS AS LO AS -43C/-31C/-34C AT THE
PAS MANITOBA. UPR MI IS ON THE PERIPHERY OF THE VERY COLD AIRMASS
ATTM...WITH 00Z H85 TEMPS RANGING FM -6C AT GRB TO -24C AT INL. LVL
WNW FLOW TO THE E OF SFC HI PRES IN THE NRN PLAINS IS ADVECTING THE
COLDER AIR INTO UPR MI...BUT RELATIVELY LIGHT WINDS HAVE SLOWED THE
ADVECTION. THIS COLD FLOW OVER THE RELATIVELY WARM WATERS OF LK SUP
IS CAUSING THE TYPICAL LK CLDS/LES IN THE FAVORED SN BELTS...BUT LO
INVRN BASE ARND H9 AS SHOWN ON THE 00Z INL/GRB RAOBS AS WELL AS DRY
NATURE OF THE LLVLS IS LIMITING THE INTENSITY OF THE SHSN. OTRW...
QUITE A BIT OF HI CLD IS STREAMING OVER MAINLY THE SE HALF OF THE
CWA WELL TO THE N OF SFC LO PRES DVLPG IN THE LOWER MS RIVER VALLEY.
MAIN FCST CONCERNS THRU THE SHORT TERM FOCUS ON TEMPS/WIND CHILLS/
GOING HEADLINES AS WELL AS LES/BLSN.
TODAY...THE CORE OF THE ARCTIC AIR OVER SCENTRAL CANADA EARLY THIS
MRNG IS FCST TO DROP OVER MN BY 00Z MON. AS THE TROF OVER CENTRAL
NAMERICA DEEPENS...THE SFC LO NOW OVER THE LOWER MS RIVER VALLEY IS
PROGGED TO DEEPEN AND MOVE INTO THE OH RIVER VALLEY. ALTHOUGH THE
LARGER SCALE FORCING/ASCENT/DEEP MOISTENING ASSOCIATED WITH THIS LO
WL REMAIN TO THE E-SE OF UPR MI...THE PRES GRADIENT/LLVL NW FLOW
OVER THE AREA IS FCST TO SHARPEN AND INCRS THE ADVECTION OF THE
COLDER AIR INTO THE CWA. MODEL CONSENSUS SHOWS H85 TEMPS FALLING FM
-23C OVER THE NW/-14C OVER THE SE AT 12Z TO -29C OVER THE NW/-19C
OVER THE SE BY 00Z MON. AS A RESULT...THE DIURNAL TEMP RECOVERY...
ESPECIALLY OVER THE WRN ZNS...WL BE NEGLIGIBLE. ALTHOUGH THE SURGE
OF LLVL COLD AIR WL SUPPORT ONGOING LES...THE LO INVRN BASES ARND
3-4K FT AND ACYC NATURE OF THE H925 FLOW/GENERAL SUBSIDENCE WL LIMIT
SN AMOUNTS...ESPECIALLY OVER THE W WHERE THE DGZ WL DESCEND INTO THE
GROUND AND LIMIT SN GROWTH. THERE MAY BE AN UPTICK IN THE LES IN THE
NW WIND SN BELTS E OF MQT LATER IN THE DAY HOWEVER AS LLVL CNVGC ON
LK INDUCED TROF SHARPENS UNDER DEEPENING UPR TROF. AS FOR GOING WIND
CHILL HEADLINES...OPTED TO DROP BARAGA...MARQUETTE AND DICKINSON
COUNTIES FM THE HEADLINE GIVEN CURRENT CONDITIONS AND EXPECTATION
THAT THESE AREAS WL NOT MEET CRITERIA MOST OF THE THE DAY.
TONIGHT...THE LO TO THE SE IS PROGGED TO DEEPEN SGNFTLY AND LIFT
NEWD INTO SE CANADA AS THE CENTRAL CONUS TROF SHARPENS WITH MORE
PHASING OF THE ARCTIC AND POLAR BRANCHES. THE CORE OF THE COLDEST
AIR...WITH H85 TEMPS DOWN TO -33C TO -35C...IS PROGGED TO SHIFT OVER
WI. AS THE LO DEEPENS...THE PRES GRADIENT WL SHARPEN FURTHER OVER
THE UPR LKS...ALLOWING H925 NW WINDS TO INCRS TO 25 TO 30 KTS. THE
STRENGTHENING WINDS AND FALLING TEMPS SUPPORT GOING WIND CHILL WRNGS
AWAY FM THE LK MODERATION THAT WL IMPACT MAINLY THE ERN CWA EVEN
THOUGH A MORE N WIND COMPONENT OFF LK SUP MIGHT NOT ALLOW TEMPS TO
FALL AS LO AS PREVIOUS FCST. BUT OVER THE ERN CWA...THE ARRIVAL OF
DEEPER MSTR ASSOCIATED WITH ARRIVAL OF DEEP LYR QVECTOR CNVGC UNDER
THE FALLING HGTS ASSOCIATED WITH THE DEEPENING UPR TROF AS WELL AS
INCRSG LLVL CNVGC ACCOMPANYING THE SHARPENING OF THE LK INDUCED SFC
TROF WL GIVE A BOOST TO THE LES. WITH MORE FVRBL SN GROWTH...H85
TEMPS ARE PROGGED TO FALL TO ARND -24C HERE BY 12Z MON...AS WELL AS
INCRSG BLSN...OPTED TO REPLACE THE WIND CHILL ADVY FOR ALGER/LUCE/
SCHOOLCRAFT COUNTIES WITH A LK EFFECT SN ADVY TO ACCOUNT FOR SN FALL
AT LEAST APRCHG ADVY AMOUNTS...BLSN AND WIND CHILLS AT LEAST APRCHG
ADVY CRITERIA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 448 AM EST SUN JAN 5 2014
THE MAIN CONCERN FOR THE LONG TERM FORECAST WILL BE EXTREMELY COLD
TEMPERATURES/WIND CHILLS AND REDUCED VISIBILITIES FROM LAKE EFFECT
SNOW SHOWERS AND BLOWING SNOW.
LOW PRESSURE TRAVELING FROM THE OHIO VALLEY TODAY WILL REACH QUEBEC
BY MONDAY MORNING. MEANWHILE...A COLD ARCTIC AIRMASS/HIGH PRESSURE
WILL SINK FROM THE CANADIAN PRAIRIE INTO THE MIDWEST AND CENTRAL
PLAINS. AS THIS HIGH SINKS TOWARDS THE GULF COAST MONDAY NIGHT...THE
LOW OVER QUEBEC WILL DRIFT WESTWARD INTO JAMES BAY. THIS PATTERN
WILL KEEP UPPER MICHIGAN IN A MODERATE WEST-NORTHWESTERLY FLOW
THROUGH WEDNESDAY...AS A TIGHTER PRESSURE GRADIENT SITS OVER THE
AREA. ADDITIONALLY...A 500MB LOW WILL CENTER ITSELF OVER UPPER MI
MONDAY MORNING...THEN DRIFT SLOWLY NORTHEASTWARD INTO ONTARIO AND
QUEBEC. WITH THE LOW CENTERED OVER UPPER MI 850-500MB QVECTOR
CONVERGENCE IS MAXIMIZED OVER THE EASTERN U.P. AND LOWER MI. WITH
NORTHWESTERLY WINDS MOVING THE COLD ARCTIC AIR OVER LAKE
SUPERIOR...KEPT POPS IN NORTHWEST WIND FAVORED SNOWBELTS. ALSO
INCREASED POPS IN THE EASTERN CWA AS THE UPPER LEVEL SUPPORT CROSSES
THROUGH THE AREA WITH THE TROUGH.
WINDS GENERALLY REMAIN NORTHWESTERLY THROUGH MONDAY AFTERNOON...THEN
BEGIN TO BACK TOWARDS THE WEST-NORTHWEST WIND DIRECTION. ADJUSTED
POPS ACCORDINGLY...WITH THE MAIN CORE OF PRECIPITATION IN THE
EASTERN U.P. SHIFTING TO AREAS FAVORED BY WNW WINDS...MAINLY EAST OF
MUNISING. ON TUESDAY SEVERAL SMALL SHORTWAVES SNEAK ALONG THE BASE
OF THE TROUGH ALOFT AS IT MOVES EASTWARD...AND WNW WINDS BECOME MORE
WESTERLY TOWARDS THE EVENING. MOST OF THE SNOW BY LATE TUESDAY
AFTERNOON WILL BE OVER THE KEWEENAW AND EAST OF GRAND MARAIS.
LIMITING FACTORS TO SIGNIFICANT ACCUMULATIONS WILL BE THE EXTREMELY
COLD/DRY AIRMASS. THIS SENDS THE DGZ CRASHING INTO THE GROUND FOR
MOST LOCATIONS...ESPECIALLY MONDAY NIGHT INTO TUESDAY AFTERNOON. AS
A RESULT SNOW RATIOS WILL BE ON THE ORDER OF 15-18:1 AND FLAKES VERY
FINE. AS FAR AS MOISTURE GOES...PWATS DURING THIS TIME FRAME DROP TO
NEAR 15 PERCENT OF NORMAL FOR UPPER MI. OVERALL...FROM MONDAY
MORNING THROUGH TUESDAY MORNING...HAVE 2-4 INCHES FOR AREAS FAVORED
BY WEST-NORTHWEST WINDS. TUESDAY MORNING INTO WED MORNING ONLY HAVE
1-3 INCHES FOR THE SAME AREAS...MAINLY THE KEWEENAW AND EAST OF
MUNISING NEAR LAKE SUPERIOR.
THE COLD ARCTIC AIRMASS WILL BRING LOW TEMPERATURES CRASHING DOWN TO
-27F OUT WEST...AND THE TEENS BELOW ZERO EAST FOR MONDAY NIGHT.
AREAS NEAR THE LAKE WILL SEE TEMPERATURES DROP DOWN TO THE SINGLE
DIGITS BELOW ZERO FARTHER EAST AND OVER THE KEWEENAW. WITH THE
STRONGER WINDS OVER THE AREA HOWEVER...WIND CHILLS WILL DROP AS LOW
AS -50F ACROSS THE WEST...AND MAINLY THE -30S AND -40S
ELSEWHERE...EVEN NEAR THE LAKE.
THOUGH SNOW ACCUMULATIONS WILL NOT BE HAZARDOUS BY THEMSELVES...THE
COMBINATION OF SNOW...BLOWING SNOW...AND DANGEROUSLY LOW
TEMPERATURES/WIND CHILLS WARRANT A LAKE EFFECT SNOW ADVISORY FOR
AREAS IN THE EAST...MAINLY FOR ALGER/LUCE/SCHOOLCRAFT COUNTIES. WIND
CHILLS WILL REACH ADVISORY CRITERIA...AND THE COMBINATION OF SNOW
AND BLOWING SNOW/DUE TO WINDS AROUND 30 MPH/ WILL REDUCE
VISIBILITIES DRAMATICALLY...ESPECIALLY WITH THE FINER FLAKES.
ELSEWHERE...HAVE ONLY THE WIND CHILL WARNING IN EFFECT FOR THE
MONDAY-TUESDAY TIME FRAME. THE KEWEENAW WILL ALSO SEE STRONG
WINDS...GUSTING TO 25 TO 30 MPH...AND PERSISTENT LAKE EFFECT SNOW
WITH AREAS OF BLOWING SNOW DURING THE MONDAY-TUESDAY TIME FRAME.
HAVE INCLUDED THIS WORDING IN THE WIND CHILL WARNING FOR THE
KEWEENAW/HOUGHTON COUNTIES FOR SIMPLICITY WITH HEADLINES.
WINDS WILL GRADUALLY DIE DOWN FROM WEDNESDAY INTO THURSDAY AS THE
HIGH CENTERS ITSELF OVER THE GREAT LAKES. LIGHT AND VARIABLE WINDS
WILL GRADUALLY TRANSITION TO MORE MODERATE SOUTH TO SOUTHWESTERLY
WINDS AS THE HIGH SHIFTS EASTWARD TOWARDS THE NEW ENGLAND
STATES...AND LOW PRESSURE MOVES INTO NORTHERN MANITOBA. SOME OF THE
MODELS ATTEMPT TO BRING A WEAK SHORTWAVE TROUGH INTO THE MIDWEST
LATE FRIDAY AFTERNOON AND SATURDAY...BUT OTHERS KEEP MORE ZONAL FLOW
OVER THE AREA. WILL KEEP THE CONSENSUS POPS DURING THIS TIME FRAME
HOWEVER...WITH THE WNW-LAKE EFFECT MOVING OUT INTO THE LAKE AS WINDS
BACK TO THE SOUTH-SOUTHWEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z MONDAY MORNING)
ISSUED AT 632 AM EST SUN JAN 5 2014
CMX...ALTHOUGH A LO INVRN BASE AND VERY DRY AIR WL LIMIT THE
INTENSITY OF THE LK EFFECT -SHSN TODAY...EXPECT IFR CONDITIONS TO
PREDOMINATE WITH OCNL MVFR VSBYS IN BTWN THE LES BANDS. WITH THE
ARRIVAL OF DEEPER MSTR AND STRENGTHENING NW WINDS/MORE BLSN TNGT...
VSBYS ARE LIKELY TO FALL INTO THE LIFR AND PERHAPS VLIFR RANGE MOST
OF THE TIME.
IWD...BACK EDGE OF LK EFFECT LO CLDS IS JUST TO THE SW OF THIS SITE
EARLY THIS MRNG. AS THE LLVL WIND BACKS A BIT EARLY TODAY...THE MVFR
CIG MAY BREAK AND GIVE WAY TO VFR CONDITIONS FOR AWHILE UNTIL THE
AFTN...WHEN A VEERING WIND WL BRING THE LK CLDS BACK OVER THIS
LOCATION. WITH THE ARRIVAL OF DEEPER MSTR AND STRENGTHENING WNW
WINDS TNGT...EXPECT LK EFFECT -SHSN/SOME BLSN TO DROP VSBYS INTO THE
IFR RANGE MOST OF THE TIME.
SAW...EXPECT VFR CONDITIONS TO PREDOMINATE THRU THIS MRNG WITH A
DOWNSLOPE WNW FLOW. MORE LK EFFECT CLDS WL ARRIVE THIS AFTN AS THE
FLOW SLOWLY VEERS MORE TOWARD THE NW AND ALLOWS MORE LK SUP
MODIFIED...MOISTER AIR TO FLOW OVER THIS SITE. ALTHOUGH THE LLVL NW
WINDS WL NOT BE IDEAL...THE ARRIVAL OF DEEPER MSTR WL RESULT IN MORE
-SHSN TNGT AND MORE SOLID MVFR CONDITIOSN.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST SUN JAN 5 2014
A GALE WATCH IS IN EFFECT FOR CENTRAL AND EASTERN LAKE SUPERIOR
MONDAY MORNING THROUGH TUESDAY NIGHT...AND A HEAVY FREEZING SPRAY
WARNING REMAINS IN EFFECT...
EXPECT NW WINDS 20-25 KTS THIS MORNING TO INCREASE TO 25-30 KTS
LATER TODAY AND TONIGHT AS THE PRES GRADIENT OVER THE UPPER GREAT
LAKES SHARPENS TO THE NW OF A DEEPENING LO PRES MOVING NE THRU THE
SE GREAT LAKES INTO SE CANADA. THERE MAY BE A FEW GALE FORCE GUSTS
OVER PORTIONS OF THE E LAKE LATE TONIGHT AS WELL. WITH ARCTIC AIR
PERSISTING OVER THE AREA...EXPECT PERIODS OF HEAVY FREEZING SPRAY...
ESPECIALLY OVER THE E HALF WHERE WINDS WILL BE STRONGEST.
LAKE SUPERIOR WILL BE CAUGHT THIS TIGHT PRESSURE GRADIENT BETWEEN
STRONG ARCTIC HIGH PRESSURE OVER THE PLAINS AND STRONG LOW PRESSURE
OVER QUEBEC MONDAY INTO TUESDAY. AS A RESULT...WEST NORTHWEST GALES
TO 35 KNOTS WILL OCCUR OVER MAINLY CENTRAL AND EASTERN LAKE SUPERIOR
ON MONDAY AFTERNOON...AND WEST NORTHWEST GALES TO 40 KNOTS WILL
OCCUR ON TUESDAY AFTERNOON. WINDS ON WESTERN LAKE SUPERIOR WILL
LARGELY REMAIN WEST-NORTHWEST AT 20 TO 30 KNOTS DURING THIS TIME.
ADDITIONALLY...COLD ARCTIC AIR IN PLACE OVER LAKE SUPERIOR COMBINED
WITH THE STRONG WINDS WILL LEAD TO HEAVY FREEZING SPRAY FOR ALL OF
THE LAKE THROUGH WEDNESDAY MORNING. ON WEDNESDAY AND THURSDAY HIGH
PRESSURE WILL MAKE ITS WAY NORTHWARD...CENTERING ITSELF OVER THE
GREAT LAKES. AS A RESULT...GUSTY WEST NORTHWEST WINDS WILL DIE
DOWN...EVENTUALLY BACKING SOUTHWEST AT LESS THAN 10 KNOTS BY
THURSDAY. AS THE HIGH SHIFTS TO THE NEW ENGLAND STATES AND LOW
PRESSURE MOVES INTO NORTHERN MANITOBA FRIDAY AFTERNOON AND
SATURDAY...SOUTHWESTERLY WINDS WILL PICK UP TO 15 TO 25 KNOTS OVER
ALL OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 11
AM EST /10 AM CST/ TUESDAY FOR MIZ001>005-009>013-084.
WIND CHILL ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ002-009-010-084.
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
MONDAY FOR MIZ006-007-014-085.
WIND CHILL WARNING FROM 7 PM MONDAY TO 11 AM EST TUESDAY FOR
MIZ006-007-014-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WATCH FROM MONDAY MORNING THROUGH LATE TUESDAY NIGHT FOR
LSZ243>245-264>266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MCD
AVIATION...KC
MARINE...KC/MCD
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
451 AM EST SUN JAN 5 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 448 AM EST SUN JAN 5 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOW DEEP POLAR VORTEX
CENTERED OVER SCENTRAL CANADA...WITH CORE OF ARCTIC AIRMASS
ACCOMPANIED BY 00Z H5/H85/H925 TEMPS AS LO AS -43C/-31C/-34C AT THE
PAS MANITOBA. UPR MI IS ON THE PERIPHERY OF THE VERY COLD AIRMASS
ATTM...WITH 00Z H85 TEMPS RANGING FM -6C AT GRB TO -24C AT INL. LVL
WNW FLOW TO THE E OF SFC HI PRES IN THE NRN PLAINS IS ADVECTING THE
COLDER AIR INTO UPR MI...BUT RELATIVELY LIGHT WINDS HAVE SLOWED THE
ADVECTION. THIS COLD FLOW OVER THE RELATIVELY WARM WATERS OF LK SUP
IS CAUSING THE TYPICAL LK CLDS/LES IN THE FAVORED SN BELTS...BUT LO
INVRN BASE ARND H9 AS SHOWN ON THE 00Z INL/GRB RAOBS AS WELL AS DRY
NATURE OF THE LLVLS IS LIMITING THE INTENSITY OF THE SHSN. OTRW...
QUITE A BIT OF HI CLD IS STREAMING OVER MAINLY THE SE HALF OF THE
CWA WELL TO THE N OF SFC LO PRES DVLPG IN THE LOWER MS RIVER VALLEY.
MAIN FCST CONCERNS THRU THE SHORT TERM FOCUS ON TEMPS/WIND CHILLS/
GOING HEADLINES AS WELL AS LES/BLSN.
TODAY...THE CORE OF THE ARCTIC AIR OVER SCENTRAL CANADA EARLY THIS
MRNG IS FCST TO DROP OVER MN BY 00Z MON. AS THE TROF OVER CENTRAL
NAMERICA DEEPENS...THE SFC LO NOW OVER THE LOWER MS RIVER VALLEY IS
PROGGED TO DEEPEN AND MOVE INTO THE OH RIVER VALLEY. ALTHOUGH THE
LARGER SCALE FORCING/ASCENT/DEEP MOISTENING ASSOCIATED WITH THIS LO
WL REMAIN TO THE E-SE OF UPR MI...THE PRES GRADIENT/LLVL NW FLOW
OVER THE AREA IS FCST TO SHARPEN AND INCRS THE ADVECTION OF THE
COLDER AIR INTO THE CWA. MODEL CONSENSUS SHOWS H85 TEMPS FALLING FM
-23C OVER THE NW/-14C OVER THE SE AT 12Z TO -29C OVER THE NW/-19C
OVER THE SE BY 00Z MON. AS A RESULT...THE DIURNAL TEMP RECOVERY...
ESPECIALLY OVER THE WRN ZNS...WL BE NEGLIGIBLE. ALTHOUGH THE SURGE
OF LLVL COLD AIR WL SUPPORT ONGOING LES...THE LO INVRN BASES ARND
3-4K FT AND ACYC NATURE OF THE H925 FLOW/GENERAL SUBSIDENCE WL LIMIT
SN AMOUNTS...ESPECIALLY OVER THE W WHERE THE DGZ WL DESCEND INTO THE
GROUND AND LIMIT SN GROWTH. THERE MAY BE AN UPTICK IN THE LES IN THE
NW WIND SN BELTS E OF MQT LATER IN THE DAY HOWEVER AS LLVL CNVGC ON
LK INDUCED TROF SHARPENS UNDER DEEPENING UPR TROF. AS FOR GOING WIND
CHILL HEADLINES...OPTED TO DROP BARAGA...MARQUETTE AND DICKINSON
COUNTIES FM THE HEADLINE GIVEN CURRENT CONDITIONS AND EXPECTATION
THAT THESE AREAS WL NOT MEET CRITERIA MOST OF THE THE DAY.
TONIGHT...THE LO TO THE SE IS PROGGED TO DEEPEN SGNFTLY AND LIFT
NEWD INTO SE CANADA AS THE CENTRAL CONUS TROF SHARPENS WITH MORE
PHASING OF THE ARCTIC AND POLAR BRANCHES. THE CORE OF THE COLDEST
AIR...WITH H85 TEMPS DOWN TO -33C TO -35C...IS PROGGED TO SHIFT OVER
WI. AS THE LO DEEPENS...THE PRES GRADIENT WL SHARPEN FURTHER OVER
THE UPR LKS...ALLOWING H925 NW WINDS TO INCRS TO 25 TO 30 KTS. THE
STRENGTHENING WINDS AND FALLING TEMPS SUPPORT GOING WIND CHILL WRNGS
AWAY FM THE LK MODERATION THAT WL IMPACT MAINLY THE ERN CWA EVEN
THOUGH A MORE N WIND COMPONENT OFF LK SUP MIGHT NOT ALLOW TEMPS TO
FALL AS LO AS PREVIOUS FCST. BUT OVER THE ERN CWA...THE ARRIVAL OF
DEEPER MSTR ASSOCIATED WITH ARRIVAL OF DEEP LYR QVECTOR CNVGC UNDER
THE FALLING HGTS ASSOCIATED WITH THE DEEPENING UPR TROF AS WELL AS
INCRSG LLVL CNVGC ACCOMPANYING THE SHARPENING OF THE LK INDUCED SFC
TROF WL GIVE A BOOST TO THE LES. WITH MORE FVRBL SN GROWTH...H85
TEMPS ARE PROGGED TO FALL TO ARND -24C HERE BY 12Z MON...AS WELL AS
INCRSG BLSN...OPTED TO REPLACE THE WIND CHILL ADVY FOR ALGER/LUCE/
SCHOOLCRAFT COUNTIES WITH A LK EFFECT SN ADVY TO ACCOUNT FOR SN FALL
AT LEAST APRCHG ADVY AMOUNTS...BLSN AND WIND CHILLS AT LEAST APRCHG
ADVY CRITERIA.
.LONG TERM...(MONDAY THROUGH SATURDAY)
ISSUED AT 448 AM EST SUN JAN 5 2014
THE MAIN CONCERN FOR THE LONG TERM FORECAST WILL BE EXTREMELY COLD
TEMPERATURES/WIND CHILLS AND REDUCED VISIBILITIES FROM LAKE EFFECT
SNOW SHOWERS AND BLOWING SNOW.
LOW PRESSURE TRAVELING FROM THE OHIO VALLEY TODAY WILL REACH QUEBEC
BY MONDAY MORNING. MEANWHILE...A COLD ARCTIC AIRMASS/HIGH PRESSURE
WILL SINK FROM THE CANADIAN PRAIRIE INTO THE MIDWEST AND CENTRAL
PLAINS. AS THIS HIGH SINKS TOWARDS THE GULF COAST MONDAY NIGHT...THE
LOW OVER QUEBEC WILL DRIFT WESTWARD INTO JAMES BAY. THIS PATTERN
WILL KEEP UPPER MICHIGAN IN A MODERATE WEST-NORTHWESTERLY FLOW
THROUGH WEDNESDAY...AS A TIGHTER PRESSURE GRADIENT SITS OVER THE
AREA. ADDITIONALLY...A 500MB LOW WILL CENTER ITSELF OVER UPPER MI
MONDAY MORNING...THEN DRIFT SLOWLY NORTHEASTWARD INTO ONTARIO AND
QUEBEC. WITH THE LOW CENTERED OVER UPPER MI 850-500MB QVECTOR
CONVERGENCE IS MAXIMIZED OVER THE EASTERN U.P. AND LOWER MI. WITH
NORTHWESTERLY WINDS MOVING THE COLD ARCTIC AIR OVER LAKE
SUPERIOR...KEPT POPS IN NORTHWEST WIND FAVORED SNOWBELTS. ALSO
INCREASED POPS IN THE EASTERN CWA AS THE UPPER LEVEL SUPPORT CROSSES
THROUGH THE AREA WITH THE TROUGH.
WINDS GENERALLY REMAIN NORTHWESTERLY THROUGH MONDAY AFTERNOON...THEN
BEGIN TO BACK TOWARDS THE WEST-NORTHWEST WIND DIRECTION. ADJUSTED
POPS ACCORDINGLY...WITH THE MAIN CORE OF PRECIPITATION IN THE
EASTERN U.P. SHIFTING TO AREAS FAVORED BY WNW WINDS...MAINLY EAST OF
MUNISING. ON TUESDAY SEVERAL SMALL SHORTWAVES SNEAK ALONG THE BASE
OF THE TROUGH ALOFT AS IT MOVES EASTWARD...AND WNW WINDS BECOME MORE
WESTERLY TOWARDS THE EVENING. MOST OF THE SNOW BY LATE TUESDAY
AFTERNOON WILL BE OVER THE KEWEENAW AND EAST OF GRAND MARAIS.
LIMITING FACTORS TO SIGNIFICANT ACCUMULATIONS WILL BE THE EXTREMELY
COLD/DRY AIRMASS. THIS SENDS THE DGZ CRASHING INTO THE GROUND FOR
MOST LOCATIONS...ESPECIALLY MONDAY NIGHT INTO TUESDAY AFTERNOON. AS
A RESULT SNOW RATIOS WILL BE ON THE ORDER OF 15-18:1 AND FLAKES VERY
FINE. AS FAR AS MOISTURE GOES...PWATS DURING THIS TIME FRAME DROP TO
NEAR 15 PERCENT OF NORMAL FOR UPPER MI. OVERALL...FROM MONDAY
MORNING THROUGH TUESDAY MORNING...HAVE 2-4 INCHES FOR AREAS FAVORED
BY WEST-NORTHWEST WINDS. TUESDAY MORNING INTO WED MORNING ONLY HAVE
1-3 INCHES FOR THE SAME AREAS...MAINLY THE KEWEENAW AND EAST OF
MUNISING NEAR LAKE SUPERIOR.
THE COLD ARCTIC AIRMASS WILL BRING LOW TEMPERATURES CRASHING DOWN TO
-27F OUT WEST...AND THE TEENS BELOW ZERO EAST FOR MONDAY NIGHT.
AREAS NEAR THE LAKE WILL SEE TEMPERATURES DROP DOWN TO THE SINGLE
DIGITS BELOW ZERO FARTHER EAST AND OVER THE KEWEENAW. WITH THE
STRONGER WINDS OVER THE AREA HOWEVER...WIND CHILLS WILL DROP AS LOW
AS -50F ACROSS THE WEST...AND MAINLY THE -30S AND -40S
ELSEWHERE...EVEN NEAR THE LAKE.
THOUGH SNOW ACCUMULATIONS WILL NOT BE HAZARDOUS BY THEMSELVES...THE
COMBINATION OF SNOW...BLOWING SNOW...AND DANGEROUSLY LOW
TEMPERATURES/WIND CHILLS WARRANT A LAKE EFFECT SNOW ADVISORY FOR
AREAS IN THE EAST...MAINLY FOR ALGER/LUCE/SCHOOLCRAFT COUNTIES. WIND
CHILLS WILL REACH ADVISORY CRITERIA...AND THE COMBINATION OF SNOW
AND BLOWING SNOW/DUE TO WINDS AROUND 30 MPH/ WILL REDUCE
VISIBILITIES DRAMATICALLY...ESPECIALLY WITH THE FINER FLAKES.
ELSEWHERE...HAVE ONLY THE WIND CHILL WARNING IN EFFECT FOR THE
MONDAY-TUESDAY TIME FRAME. THE KEWEENAW WILL ALSO SEE STRONG
WINDS...GUSTING TO 25 TO 30 MPH...AND PERSISTENT LAKE EFFECT SNOW
WITH AREAS OF BLOWING SNOW DURING THE MONDAY-TUESDAY TIME FRAME.
HAVE INCLUDED THIS WORDING IN THE WIND CHILL WARNING FOR THE
KEWEENAW/HOUGHTON COUNTIES FOR SIMPLICITY WITH HEADLINES.
WINDS WILL GRADUALLY DIE DOWN FROM WEDNESDAY INTO THURSDAY AS THE
HIGH CENTERS ITSELF OVER THE GREAT LAKES. LIGHT AND VARIABLE WINDS
WILL GRADUALLY TRANSITION TO MORE MODERATE SOUTH TO SOUTHWESTERLY
WINDS AS THE HIGH SHIFTS EASTWARD TOWARDS THE NEW ENGLAND
STATES...AND LOW PRESSURE MOVES INTO NORTHERN MANITOBA. SOME OF THE
MODELS ATTEMPT TO BRING A WEAK SHORTWAVE TROUGH INTO THE MIDWEST
LATE FRIDAY AFTERNOON AND SATURDAY...BUT OTHERS KEEP MORE ZONAL FLOW
OVER THE AREA. WILL KEEP THE CONSENSUS POPS DURING THIS TIME FRAME
HOWEVER...WITH THE WNW-LAKE EFFECT MOVING OUT INTO THE LAKE AS WINDS
BACK TO THE SOUTH-SOUTHWEST.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SUNDAY NIGHT)
ISSUED AT 1226 AM EST SUN JAN 5 2014
COLD AIR CONTINUES TO FILTER ACROSS THE UPPER LAKES...WITH LAKE
EFFECT SNOW SHOWERS CONTINUING ACROSS THE KEWEENAW PENINSULA
INCLUDING KCMX. SEE NO REASON WHY THE SNOW SHOWERS WILL NOT CONTINUE
THROUGH THE PERIOD AT KCMX AS THE ARCTIC AIRMASS MOVES OVERHEAD LATE
SUNDAY. EXPECT MVFR CONDITIONS AT CMX TO CONTINUE OVERNIGHT INTO
EARLY SUNDAY AFTERNOON BEFORE STRONGER WINDS AND FINE SNOWFLAKES
HELP TO REDUCE THE VSBY TO IFR DESPITE THE SNOW NOT EXPECTED TO BE
TERRIBLY HEAVY. AS FOR IWD...A LIGHT LAND BREEZE HAS DEVELOPED WHICH
SHOULD HELP TO KEEP SNOW NORTH OF THE SITE TONIGHT. AS THE WINDS
SHIFT BACK TO THE W-NW ON SUNDAY...EXPECT A RETURN OF SNOW SHOWERS
WITH MVFR VSBYS. THE W-NW FLOW AT KSAW SHOULD KEEP VFR VSBYS THROUGH
THE PERIOD. IN FACT...THE MVFR CEILING MAY DISAPPEAR OVERNIGHT AS
THE ARCTIC AIRMASS BUILDS ACROSS THE AREA...HOWEVER EXPECT IT TO
RETURN ON SUNDAY AS THE FLOW BECOMES NORTHWESTERLY AGAIN WITH A
SLIGHT INCREASE OF LOWER MOISTURE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 448 AM EST SUN JAN 5 2014
A GALE WATCH IS IN EFFECT FOR CENTRAL AND EASTERN LAKE SUPERIOR
MONDAY MORNING THROUGH TUESDAY NIGHT...AND A HEAVY FREEZING SPRAY
WARNING REMAINS IN EFFECT...
EXPECT NW WINDS 20-25 KTS THIS MORNING TO INCREASE TO 25-30 KTS
LATER TODAY AND TONIGHT AS THE PRES GRADIENT OVER THE UPPER GREAT
LAKES SHARPENS TO THE NW OF A DEEPENING LO PRES MOVING NE THRU THE
SE GREAT LAKES INTO SE CANADA. THERE MAY BE A FEW GALE FORCE GUSTS
OVER PORTIONS OF THE E LAKE LATE TONIGHT AS WELL. WITH ARCTIC AIR
PERSISTING OVER THE AREA...EXPECT PERIODS OF HEAVY FREEZING SPRAY...
ESPECIALLY OVER THE E HALF WHERE WINDS WILL BE STRONGEST.
LAKE SUPERIOR WILL BE CAUGHT THIS TIGHT PRESSURE GRADIENT BETWEEN
STRONG ARCTIC HIGH PRESSURE OVER THE PLAINS AND STRONG LOW PRESSURE
OVER QUEBEC MONDAY INTO TUESDAY. AS A RESULT...WEST NORTHWEST GALES
TO 35 KNOTS WILL OCCUR OVER MAINLY CENTRAL AND EASTERN LAKE SUPERIOR
ON MONDAY AFTERNOON...AND WEST NORTHWEST GALES TO 40 KNOTS WILL
OCCUR ON TUESDAY AFTERNOON. WINDS ON WESTERN LAKE SUPERIOR WILL
LARGELY REMAIN WEST-NORTHWEST AT 20 TO 30 KNOTS DURING THIS TIME.
ADDITIONALLY...COLD ARCTIC AIR IN PLACE OVER LAKE SUPERIOR COMBINED
WITH THE STRONG WINDS WILL LEAD TO HEAVY FREEZING SPRAY FOR ALL OF
THE LAKE THROUGH WEDNESDAY MORNING. ON WEDNESDAY AND THURSDAY HIGH
PRESSURE WILL MAKE ITS WAY NORTHWARD...CENTERING ITSELF OVER THE
GREAT LAKES. AS A RESULT...GUSTY WEST NORTHWEST WINDS WILL DIE
DOWN...EVENTUALLY BACKING SOUTHWEST AT LESS THAN 10 KNOTS BY
THURSDAY. AS THE HIGH SHIFTS TO THE NEW ENGLAND STATES AND LOW
PRESSURE MOVES INTO NORTHERN MANITOBA FRIDAY AFTERNOON AND
SATURDAY...SOUTHWESTERLY WINDS WILL PICK UP TO 15 TO 25 KNOTS OVER
ALL OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING FROM 7 PM EST /6 PM CST/ THIS EVENING TO 11
AM EST /10 AM CST/ TUESDAY FOR MIZ001>005-009>013-084.
WIND CHILL ADVISORY UNTIL 7 PM EST /6 PM CST/ THIS EVENING FOR
MIZ002-009-010-084.
LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
MONDAY FOR MIZ006-007-014-085.
WIND CHILL WARNING FROM 7 PM MONDAY TO 11 AM EST TUESDAY FOR
MIZ006-007-014-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WATCH FROM MONDAY MORNING THROUGH LATE TUESDAY NIGHT FOR
LSZ243>245-264>266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...MCD
AVIATION...MRD
MARINE...KC/MCD
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
305 PM CST SUN JAN 5 2014
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 305 PM CST SUN JAN 5 2014
NORTHWEST WINDS HAVE INCREASED SUBSTANTIALLY ACROSS WEST CENTRAL
THROUGH SOUTH CENTRAL MN THIS AFTERNOON WITH 20-25 KNOTS COMMON.
THIS IS OCCURRING AS THE CORE OF THE ARCTIC AIR ARRIVES ALONG WITH
THE PRESSURE GRADIENT TIGHTENING BETWEEN A LOW PRESSURE STORM SYSTEM
MOVING THROUGH THE OHIO VALLEY AND A 1053MB HIGH OVER MONTANA.
WEB CAMS ARE SHOWING BLOWING SNOW WITH 1 TO 2 MILE VISIBILITY IN
THE AFOREMENTIONED AREAS. THE BLOWING SNOW WILL CONTINUE THROUGH
THE EVENING ADDING ANOTHER ELEMENT OF DANGER TO THE ALREADY LOW
WINDS CHILLS OF -40 TO -45 CURRENTLY IN PLACE. SATELLITE IMAGERY
SHOWS SOME NICE CONVECTIVE ROLLS AS WELL IN THE MN RIVER VALLEY WITH
THE RAP INDICATING LOW LEVEL LAPSE RATES EXCEEDING 8 DEG C/KM.
LITTLE DEVIATION TO THE FORECAST LOWS/HIGHS FOR TONIGHT AND
MONDAY AS THE CORE OF THE ARCTIC VORTEX SWINGS THROUGH. MUCH OF
CENTRAL MN AND ALONG HIGHWAY 8 IN WEST CENTRAL WI EXPECTED TO
REACH -30 TO -35 WITH -25 TO -30 OVER THE REMAINDER OF THE FA.
HIGHS ON MONDAY PROGGED TO BE IN THE -13 TO -19 RANGE FROM SOUTH
TO NORTH. WIND CHILL VALUES OVERNIGHT AND MONDAY MORNING FROM -50
TO -65 WITH -40 TO -50 FOR MONDAY AFTERNOON.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 305 PM CST SUN JAN 5 2014
THE MAIN WX DISCUSSION IS THAT THE CORE OF THE COLDEST AIR WILL HAVE
MOVED OUT OF THE REGION BY MONDAY NIGHT WITH ONLY RESIDUAL AFFECTS
BASED ON WIND SPDS AND TEMPS STILL IN THE TEENS AND 20S BLW ZERO
THRU TUESDAY MORNING. AS HIGH PRESSURE MOVES OVERHEAD TUESDAY
NIGHT/WEDNESDAY...THE AFFECTS OF RADIATIONAL COOLING MAY AID IN SOME
LOWER TEMPS THAN CURRENTLY FORECAST. BASED ON CURRENT MODEL TRENDS
NEAR -20F IN THE NORTHERN CWA...TO THE SINGLE DIGITS BLW ZERO IN THE
SOUTHERN CWA SEEMS REASONABLE AT THIS TIME.
AFTER WEDNESDAY...THE JET STREAM WILL MOVE NORTH WITH A MORE ZONAL
FLOW DEVELOPING BY THE END OF THE WEEK. THIS WILL LEAD TO MUCH
WARMER TEMPS BY FRI/SAT/SUN WITH ABV NORMAL READINGS ALMOST LIKELY.
MODELS ARE STILL HAVING TROUBLE HANDLING THE SPLIT FLOW REGIME.
BASICALLY FOR OUR REGION IT MEANS THAT UNCERTAINTY EXISTS AS MODELS
ARE TRYING TO HOLD ONTO THE SOUTHERN JET AS THE MOST ACTIVE WX IN
THE NEXT 7 DAYS. CONFIDENCE WILL REMAIN LOW UNTIL MODELS HAVE A
BETTER HANDLE ON THE SOUTHERN JET STREAM STORM SYSTEM THAT WILL
AFFECT THE SOUTHERN U.S. NEXT WEEKEND. AS FOR OUR AREA...MAINLY DRY
WX WILL CONTINUE WITH A MUCH ANTICIPATED WARMING TREND AT LEAST IN
THE SHORT TERM AFTER WEDNESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z MONDAY AFTERNOON)
ISSUED AT 1149 AM CST SUN JAN 5 2014
THE CORE OF THE ARCTIC VORTEX IS PUSHING ACROSS THE DAKOTAS LATE
THIS MORNING. A 3 TO 4 HOUR PERIOD OF MVFR CEILINGS AND IFR VSBYS
IN -SN/BLSN WILL PRECEDE THIS FEATURE AS IT MOVES THROUGH THIS
AFTERNOON AND EARLY EVENING. A CONCERN IS THAT BLOWING SNOW MAY BE
WORSE THAN WHAT THE KAXN AND KRWF TAFS INDICATE. THE BELIEF IS
THAT THE MELTING AND MIXED PRECIP THAT OCCURRED TWO NIGHTS AGO WILL
AID IN KEEPING THINGS MORE IN THE 1 TO 2 MILE RANGE. STRONG NW
WINDS WILL MOVE INTO THE WESTERN TAF SITES EARLY THIS AFTERNOON
AND PUSH EAST THROUGH THE EVENING. SUSTAINED SPEEDS IN THE 20 TO
25 KNOT RANGE EXPECTED IN THE MN RIVER VALLEY WITH GUSTS REACHING
INTO THE LOW 30 KNOT RANGE. SPEEDS A LITTLE LESS FOR THE EASTERN
SITES LATE THIS AFTERNOON AND EVENING. ONCE THE TROUGH ALOFT
PASSES...VFR CONDITIONS EXPECTED LATER THIS EVENING THROUGH
MONDAY.
KMSP...NW WINDS ARE ALREADY BEGINNING TO GUST LATE THIS MORNING
AND WILL CONTINUE TO INCREASE DURING THE AFTERNOON AND EARLY
EVENING HOURS. NW WINDS AROUND 20 KNOTS FOR THE LATE AFTERNOON AND
EVENING WITH GUSTS REACHING 30 KNOTS. THIS COMBINED WITH THE COLD
TEMPS WILL CAUSE WIND CHILL VALUES FROM -30 TO -40 FOR THOSE
WORKING OUTDOORS. A PERIOD OF MVFR CEILINGS/VSBY IN -SN EXPECTED
AS WELL DURING THE LATE AFTERNOON AND EARLY EVENING...MARKING THE
ARRIVAL OF THE COLD AIR ALOFT. VFR CONDITIONS THEREAFTER WITH
BRISK NW WINDS THROUGH MONDAY.
/OUTLOOK FOR KMSP/
MON...VFR. NW WINDS 10-20 KT.
TUE...VFR. W WINDS 5-10 KT.
WED...VFR. WINDS NEAR CALM.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR MNZ041>045-047>070-
073>078-082>085-091>093.
WI...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ014>016-023>028.
&&
$$
SHORT TERM...RAH
LONG TERM...JLT
AVIATION...RAH
AREA FORECAST DISCUSSION...UPDATED AVIATION
NWS ST LOUIS MO
1153 PM CST Sat Jan 4 2014
.UPDATE:
Issued at 810 PM CST Sat Jan 4 2014
Going to be making a few tweaks to the going forecast based on the
latest model data that is coming in.
1. Precipitation will stay in liquid form across far southern CWA
for much of the overnight period, and perhaps into Sunday morning.
Still forecasting just over six inches for storm total - so no
headline changes needed.
2. Latest NAM, HRRR and RAP model runs show intense upward vertical
motion and convective potential due to steep lapse rates and hints
of true CAPE, or upright convective potentional, tomorrow morning
across the warned area and therefore will be adding mention of
thunder to forecast. Certainly potential for localized snowfall
totals over 12 inches.
Updated forecast and graphics will be out by 9 p.m.
CVKING
&&
.SHORT TERM: (Through Tuesday Afternoon)
Issued at 342 PM CST Sat Jan 4 2014
(Tonight - Sunday)
Main forecast issue here is major winter storm set to impact the
entire area.
Forecast by and large is on track from previous shifts with only
minor adjustments made. A major winter storm is set to develop
later tonight and continue thru much of the day on Sunday. The
components for this storm include a strong shortwave over the
east-central Rockies which is expected to drop a bit further south
before moving east into the Mid-MS valley, being steered on this
track by a powerful Polar vortex located over northern MN and
western Ontario. By nightfall Sunday afternoon-evening, pcpn is
expected to have ended over our region, other than some stray
flurries.
In the meantime, a cold front, now entering northeast MO, will
continue to push SE thru our region, getting thru the final SE MO
and S IL counties by daybreak Sunday. Temps will fall several
degrees behind this front and will have no problem dropping into the
20s and below, given this is the leading edge of very bitter cold
air. Ahead of the front, however, temps will struggle to drop below
freezing with clouds and south winds.
Pcpn associated with the front has already taken shape in NW MO and
S IA and N IL and this band of snow will gradually drop SE into the
UIN area this evening and into mid-MO by late evening before some
measure of re-organization takes place as the main system
strengthens to the W. Pcpn-types may be rain or sleet early but
should quickly become all snow with approach of or passage of cold
front and should only be a minor concern. The stronger system snow
will merge with and overtake the frontal snow late tonight as
incredible lift thanks to frontogenesis and jet dynamics enters
central and SE MO and then propagates northeastward into STL Metro
Sunday morning and eventually into SW IL for a good portion on
Sunday. Goree-Younkin-Brown technique continues to target a track
from the central Ozarks to just S and E of downtown STL City and
curving northeastward into IL for heaviest snowfall potential, with
a foot or more of new snow not out of the question. Snowfall
amounts associated with maps represent median, most likely values,
but higher amounts near the track described above quite possible
with higher liquid-to-snow ratios (LSRs) as very cold air builds in
at the lo levels. During its peak from very late tonight thru
Sunday morning and into early afternoon, snowfall rates at times may
top 2" per hour.
The visibility reductions with snow combined with wind gusts of
30-35 mph will result in near blizzard conditions for a time on
Sunday.
When it is done by nightfall early Sunday evening, snowfall amounts
from 4-6" can be expected along a UIN-COU axis with 8-12" for STL
metro and areas just S and E with locally higher amounts.
However, that is only the beginning. Blowing snow will begin to be
a real issue by late Sunday morning on once enough snow has fallen
and strong winds kick in from the strong CAA. This will lead to
impassable roads in places and very lo visibilities.
Winter storm headline types will continue with only slight
adjustments to timing at the end.
(Sunday Night - Tuesday)
Main forecast issue for this period will be extreme cold, with winds
dropping wind chill values to dangerous levels. Lingering issues
from the winter storm will also be a concern.
Blowing snow issues will continue thru at least Sunday night and
perhaps into Monday as the coldest air of my career builds in,
maintaining the strong winds, acting upon what should be a deep
snowpack across much of our region.
Of greater concern is widespread sub-zero temps...dipping to 5 to 15
below Sunday night...only rising to zero to 5 below on Monday...
dropping again to zero to 10 below Monday night...finally bobbing
above zero on Tuesday. We have not seen a prolonged period of
sub-zero for most locations for two or three decades and this cannot
be emphasized enough...this cold will be extremely dangerous when
combined with the wind...giving us once-in-a-generation magnitude of
cold...taking mere minutes to frostbite on exposed skin.
Despite being a couple days out, went ahead and will issue a wind
chill warning to elevate the word on the danger that the cold and
wind will bring to our area.
TES
.LONG TERM: (Wednesday through Next Saturday)
Issued at 342 PM CST Sat Jan 4 2014
The moderation in temperatures that begins on Tuesday will
continue throughout the week as longwave pattern transitions to a
zonal flow pattern over the CONUS, shunting the coldest air to our
north. By Friday and Saturday it would appear that high temps will
finally rebound to near average temperatures, ranging from the
middle 30s in the north to the middle 40s in the south.
Medium range solutions are still forecasting several shortwave
trofs to push into the Central U.S. during the latter half of the
week, with ascent associated with these features combining with
isentropic lift and moisture advection in the return flow to
produce several chances for precipitation. As mentioned in
previous AFD, p-type gets a bit tricky with time: initially all
snow, but with a slow warming throughout the lower troposphere
ptype there may be a transition to sleet over southern areas
Wednesday night and Thursday. By Friday, continuing warming
appears to support all rain, with a threat of freezing rain during
the morning as surface temps are below 32 at that time.
TRUETT
&&
.AVIATION: (For the 06z TAFs through 06z Sunday Night)
Issued at 1145 PM CST Sat Jan 4 2014
Not much has changed in the overall forecast. Confidence has
increased that very heavy snowfall is anticipated for SUS/STL/CPS
shortly after what should be sunrise...12z. Have lowered visbys,
but to keep TAF shorter, not as low as what that time period may
see at times. Other question is timing of onset for SUS/STL/CPS as
precip will be coming from N as well as the S. Light RA or DZ shud
continue off and on until SN finally begins. For UIN/COU, event is
underway and timing still appears to be on track.
&&
.CLIMATE:
Issued at 1130 PM CST Thu Jan 2 2014
Last occurrence of a min temp of zero degrees or lower at KSTL:
0 on January 21, 2011
-5 on January 5, 1999
RECORD LOW TEMPERATURES
January 6 January 7
St. Louis -11/1884 -14/1912
Columbia -12/1912 -20/1912
Quincy -9/1970 -19/1912
RECORD LOW MAXIMUM TEMPERATURES
January 6 January 7
St. Louis 0/1912 0/1912
Columbia -3/1912 2/1912
Quincy -3/1912 -2/1912
Phillipson
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...WINTER STORM WARNING until 6 PM CST Sunday FOR Crawford MO-Iron
MO-Jefferson MO-Madison MO-Reynolds MO-St. Francois MO-Ste.
Genevieve MO-Washington MO.
WIND CHILL WARNING from Midnight Sunday Night to Noon CST
Tuesday FOR Crawford MO-Iron MO-Madison MO-Reynolds MO-St.
Francois MO-Ste. Genevieve MO-Washington MO.
WINTER STORM WARNING until 3 PM CST Sunday FOR Franklin MO-
Gasconade MO-Lincoln MO-Montgomery MO-Osage MO-St. Charles
MO-St. Louis City MO-St. Louis MO-Warren MO.
WIND CHILL WARNING from 6 PM Sunday to Noon CST Tuesday FOR
Audrain MO-Boone MO-Callaway MO-Cole MO-Franklin MO-
Gasconade MO-Jefferson MO-Knox MO-Lewis MO-Lincoln MO-
Marion MO-Moniteau MO-Monroe MO-Montgomery MO-Osage MO-Pike
MO-Ralls MO-Shelby MO-St. Charles MO-St. Louis City MO-St.
Louis MO-Warren MO.
WINTER WEATHER ADVISORY until 3 PM CST Sunday FOR Audrain MO-
Boone MO-Callaway MO-Cole MO-Knox MO-Lewis MO-Marion MO-
Moniteau MO-Monroe MO-Pike MO-Ralls MO-Shelby MO.
IL...WINTER STORM WARNING until 6 PM CST Sunday FOR Bond IL-Clinton
IL-Fayette IL-Marion IL-Monroe IL-Montgomery IL-Randolph IL-
St. Clair IL-Washington IL.
WIND CHILL WARNING from Midnight Sunday Night to Noon CST
Tuesday FOR Randolph IL.
WINTER STORM WARNING until 3 PM CST Sunday FOR Calhoun IL-Greene
IL-Jersey IL-Macoupin IL-Madison IL.
WIND CHILL WARNING from 6 PM Sunday to Noon CST Tuesday FOR
Adams IL-Bond IL-Brown IL-Calhoun IL-Clinton IL-Fayette IL-
Greene IL-Jersey IL-Macoupin IL-Madison IL-Marion IL-Monroe
IL-Montgomery IL-Pike IL-St. Clair IL-Washington IL.
WINTER WEATHER ADVISORY until 3 PM CST Sunday FOR Adams IL-Brown
IL-Pike IL.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
1015 PM EST MON JAN 6 2014
.SYNOPSIS...
ARCTIC HIGH PRESSURE WILL BUILD OVER THE AREA TONIGHT AND TUESDAY.
THE HIGH WILL SHIFT TO THE NORTH WEDNESDAY NIGHT. A TROF OF LOW
PRESSURE WILL DEVELOP ALONG THE SOUTHEAST COAST THURSDAY AND
LINGER INTO FRIDAY...THEN DISSIPATE FRIDAY NIGHT. A COLD FRONT
WILL MOVE THROUGH FROM THE WEST SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
AS OF 10 PM MON...WHILE THE SFC COLD FRONT WENT THROUGH THIS
AFTERNOON ALLOWING TEMPS TO DROP PRETTY QUICKY...THE ARCTIC 850MB
FRONT IS JUST NOW TRAVERSING OUR AREA. BASED ON SATELLITE IMAGERY
ONE CAN CLEARLY DELINEATE THE TROUGHS/FRONTS ALOFT MIGRATING
THROUGH THE CAROLINAS. THE 850MB CROSSING OUR CWA AND THE 700MB
TROUGH CROSSING RAH CWA. AS THE UPPER LEVEL TROUGH CONTINUES TO
PIVOT THROUGH THE AREA...IT WILL ACT AS A CONTINUED SOURCE FOR
THE POLAR AIR ADVECTING INTO THE REGION. TEMPS ARE BEEN A BIT
SLOWER TO DROP (CURRENTLY IN THE 30S) DUE TO THESE FRONTS SLOWLY
PASSING THROUGH...AND CLOUD COVER IN PLACE. HOWEVER...ANTICIPATE
CAA TO CONTINUE THROUGH THE OVERNIGHT...ESPECIALLY A QUICKER DROP
IN TEMPS ONCE THE 700MB FRONT MOVES THROUGH AND STRONG CAA FROM
THE NNW WORKS ITS WAY IN. HRRR IS SUGGESTING TEMPS MAY BE A BIT
TOO LIBERAL BY EARLY TOMORROW MORNING (ESPECIALLY TEMPS CLOSET TO
THE COAST)...BUT WILL KEEP WITH THE TREND FOR NOW AND MODIFY AS
NEEDED. EITHER WAY...WITH WINDY CONDITIONS AND TEMPS IN THE TEENS
ACROSS MUCH OF THE REGION...WIND CHILL WILL BE AN ISSUE EARLY
TOMORROW MORNING.
PREVIOUS DISCUSSION...VERY COLD TEMPS EXPECTED OVERNIGHT WITH LOWS GENERALLY
13-20 DEGREES...AS 850MB TEMPS PLUNGE TO -12 TO -16C OVERNIGHT.
WIND CHILL ADVISORY REMAINS IN EFFECT FOR ENTIRE AREA OVERNIGHT
INTO TUESDAY MORNING...WITH GUSTY NWLY WINDS RESULTING IN WC
VALUES OF 0 TO -5 DEGREES TUESDAY MORNING. RECORD BREAKING LOW
TEMPS ARE EXPECTED...SEE CLIMATE SECTION BELOW FOR ADDITIONAL
INFO.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
AS OF 245 PM MON...SURFACE RIDGE OVER THE GULF STATES WILL GRADUALLY
EXPAND THIS WAY ON TUESDAY. VERY DRY AND VERY COLD AIRMASS IN
PLACE WITH HIGHS ONLY IN THE MID TO UPPER 20S UNDER SUNNY SKIES.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
AS OF 245 PM MON...THIS PERIOD WILL SEE A TRANSITION FROM UPPER
TROUGHING TO RIDGING WITH A RECORD COLD REGIME EVENTUALLY
TRANSITIONING TO ONE FEATURING ABOVE NORMAL TEMPERATURES BY THE
WEEKEND.
THE CORE OF THE ARCTIC AIR MASS WILL SETTLE ACROSS THE AREA EARLY
THIS FORECAST PERIOD. CLEAR SKIES WITH DIMINISHING WIND WILL ALLOW
TEMPS TO PLUMMET INTO THE LOWER TEENS WITH STRONG RADIATIONAL
COOLING TUE NIGHT BUT WIND CHILL VALUES WILL NOT BE MUCH OF A
FACTOR DUE TO THE ABSENCE OF WIND. MANY LOCATIONS WILL BE NEAR
RECORD LOWS AGAIN WEDNESDAY MORNING.
THE AIR MASS BEGINS TO MODERATE WED WITH SFC HIGH PRES CENTERED
OVER THE REGION BUT HIGH TEMPS AROUND 40 DEGREES WILL STILL BE WELL
BELOW NORMAL. SFC HIGH PRES SLIDES OFF THE COAST NE OF THE AREA WED
NIGHT AND THU WITH VEERING WINDS BRINGING A MILDER TEMPERATURE
TREND FOR THE LATTER HALF OF THE WEEK. HIGHS EXPECTED IN THE LOW 50S
THURS WITH HIGHS FRIDAY LARGELY IN THE 55 TO 60F DEG RANGE. THE
MODERATION CONTINUES INTO THE WEEKEND PRODUCING HIGHS IN THE 60S ON
SATURDAY AND POSSIBLY INTO EARLY NEXT WEEK.
PRECIP CHANCES WILL ALSO BE INCREASING LATE IN THE WEEK AND INTO THE
WEEKEND AS A MORE UNSETTLED WEATHER PATTERN DEVELOPS. A WEAK
INVERTED TROF OFF THE SE COAST MAY PRODUCE SOME LIGHT RAIN OVER THE
AREA LATE THURSDAY INTO FRIDAY. A MORE SUBSTANTIAL THREAT FOR RAIN
APPEARS TO BE TAKING SHAPE FOR SATURDAY AS MODELS BEGINNING TO SHOW
REASONABLE CONTINUITY FOR DEVELOP A MOIST SW FLOW AHEAD OF
APPROACHING SHORT WAVE TROF AND ACCOMPANYING COLD FRONT. THERE IS
ALSO DECENT AGREEMENT FOR A COLD FRONT PASSAGE SAT NIGHT OR EARLY
SUNDAY. WILL HANG ONTO SLIGHT CHANCE POPS SUNDAY FOR NOW AS GFS IS
SOMEWHAT LESS PROGRESSIVE. NO REAL COLD AIR BEHIND THE INITIAL FRONT
SO HIGHS ON SUNDAY MAY AGAIN REACH INTO THE 60S. A SOUTHERN STREAM
SHORT WAVE APPROACHES EARLY NEXT WEEK LEADING TO BETTER CHANCE OF
SHOWERS ALONG WITH MILD TEMPS ON MONDAY.
&&
.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TUESDAY/...
AS OF 645 PM MON...PRED VFR CONDITIONS EXPECTED THROUGH THE TAF
PERIOD WITH CLEAR SKIES. GUSTY NWLY WINDS 15-20KT WILL CONTINUE
OVERNIGHT INTO TUESDAY.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 245 PM MON...POST ARCTIC FRONT, STRONG CAA BRINGS A VERY DRY
AIRMASS TO THE AREA WITH PREDOMINANT VFR THRU MIDWEEK. INCREASING
CLOUDS THU AHEAD OF A WEAK COASTAL TROF AND SHOULD SEE A FEW
SHOWERS AND POSSIBLE SUB-VFR CONDITIONS BEGINNING THU NIGHT AND ON
INTO THE WEEKEND AS AN UNSETTLED WEATHER PATTERN TAKES SHAPE OVER
THE AREA.
&&
.MARINE...
SHORT TERM /THROUGH TUESDAY/...
AS OF 10 PM MON...NO CHANGES NEEDED.
PREVIOUS FORECAST...LATEST OBS SHOW W/NW WINDS 15-25KT WITH A FEW
GUSTS TO 30KT FOR THE SOUTHERN WATERS. WINDS WILL CONTINUE TO
INCREASE TO GALE FORCE THIS EVENING AND PEAK OVERNIGHT/EARLY
TUESDAY MORNING WITH STRONG CAA BEHIND ARCTIC FRONT THAT HAS MOVED
OFFSHORE. GALE FORCE WINDS STILL EXPECTED OVER THE COASTAL WATERS
AND SOUNDS TONIGHT INTO TUESDAY...THOUGH BOTH SOUNDS WILL SEE IT
MAINLY IN GUSTS. TIGHT PRESSURE GRADIENT TONIGHT WILL LOOSEN ON
TUESDAY AS HIGH PRESSURE OVER THE GULF COAST STATES MOVES IN OUR
DIRECTION.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 245 PM MON...WINDS GRADUALLY SUBSIDE TO 10 TO 15 KT TUE NIGHT
AS HIGH PRES BUILDS INTO THE REGION. HIGH PRES PROGGED TO BE
CENTERED ACROSS THE WATERS WED INTO EARLY THURS BRINGING LIGHT
WINDS AND MUCH REDUCED SEAS. E/SE WINDS/SEAS 10 TO 15 KT WILL BE
FORECAST AHEAD OF A COASTAL LOW PRES TROF LATE THURSDAY THRU
FRIDAY. WINDS TURN S/SW AND INCREASE AHEAD OF AN INCOMING COLD
FRONT EARLY IN THE WEEKEND AND MAY SEE MARGINAL SMALL CRAFT
ADVISORY CONDITIONS DEVELOP ON SATURDAY.
&&
.CLIMATE...
RECORD MIN TEMPS FOR JANUARY 7TH:
NEW BERN 23 2010
CAPE HATTERAS 27 1984
WILLIAMSTON 18 1995
KINSTON 15 1969
GREENVILLE 10 1924
BAYBORO 20 1988
MOREHEAD CITY 23 2010
OCRACOKE 28 1999
MANTEO 23 1988
WASHINGTON 25 2010
RECORD LOW MAX TEMPS FOR JANUARY 7TH:
NEW BERN 34 1988
CAPE HATTERAS 38 1973
WILLIAMSTON 29 1988
KINSTON 26 1942
GREENVILLE 27 1924
BAYBORO 30 1988
MOREHEAD CITY 33 1988
OCRACOKE 40 2010
MANTEO 33 1988
WASHINGTON 43 2010
RECORD MIN TEMPS FOR JANUARY 8TH:
NEW BERN 18 1970
CAPE HATTERAS 20 1970
WILLIAMSTON 16 1970
KINSTON 16 1968
GREENVILLE 13 1986
BAYBORO 19 1986
MOREHEAD CITY 16 1968
OCRACOKE 23 1968
MANTEO 20 1986
WASHINGTON 21 1903
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...WIND CHILL ADVISORY FROM 3 AM TO 10 AM EST TUESDAY FOR NCZ029-
044>047-079>081-090>095-098-103-104.
MARINE...GALE WARNING UNTIL 10 AM EST TUESDAY FOR AMZ130-135-156-158.
GALE WARNING UNTIL 1 PM EST TUESDAY FOR AMZ150-152-154.
&&
$$
SYNOPSIS...HSA
NEAR TERM...HSA/CQD/LEP
SHORT TERM...HSA
LONG TERM...BTC
AVIATION...BTC/CQD
MARINE...BTC/HSA/CQD/LEP
CLIMATE...
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
747 AM EST SUN JAN 5 2014
.SYNOPSIS...
LOW PRESSURE WILL TRACK WEST OF PENNSYLVANIA LATER
TODAY. A TRAILING ARCTIC COLD FRONT WILL SWEEP THROUGH
PENNSYLVANIA EARLY MONDAY. UPPER LOW AND ASSOCIATED ARCTIC AIR
MASS WILL LIFT OUT OF THE AREA LATER NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON UPSTREAM OBS AND LATEST MDL OUTPUT...HAVE DELAYED ARRIVAL
OF RA/ZR ACROSS THE AREA TODAY. FZRA REPORTED AT KBWI AT 10Z AND
LATEST RAP SUGGESTS -FZRA COULD ENTER YORK/LANCASTER COS AFTER
12Z. WAA UNDERWAY EARLY THIS MORNING WITH 8H TEMPS ALREADY RISING
ABV 0C ACROSS SOUTHERN PA AT 10Z. MEANWHILE...SFC TEMPS IN THE
SINGLE DIGITS ACROSS MANY PARTS OF CENTRAL PA...CREATING A CLASSIC
FZRA SOUNDING PROFILE. EXPECT WARMER AIR TO EVENTUALLY WIN OUT BY
EARLY EVENING ACROSS THE EASTERN COUNTIES...AS WEAK SFC LOW
LIFTING UP THE COASTAL PLAIN TRACKS ACROSS EASTERN PA. PER WWD
GRAPHICS...EXPECT FZRA ACCRETION TO BE LESS THAN A TENTH OF AN
INCH...BUT ENOUGH TO CREATE POTENTIAL TRAVEL PROBLEMS.
BY EARLY EVENING...STEADIEST RAIN ASSOC WITH WEAK SFC LOW SHOULD
BE EXITING THE EASTERN COUNTIES. MEANWHILE...LIGHTER -DZ/-FZDZ
COULD LINGER OVR THE CENTRAL MTNS AND SUSQ VALLEY...WHERE SREF AND
NAM INDICATE A POCKET OF LINGERING SFC TEMPS NR 32F.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
BATCH OF PRECIP ASSOC WITH WEAK COASTAL LOW SHOULD BE EXITING
EASTERN PA EARLY THIS EVENING. MEANWHILE...PRIMARY SURFACE LOW WILL TRACK
WEST OF PA TONIGHT...KEEPING CENTRAL PA IN THE WARM SECTOR FOR MUCH
OF THE NIGHT. ANY POCKETS OF SUB-FREEZING AIR SHOULD BE SCOURED
OUT OF THE VALLEYS DURING THE EVENING...AS DEEP SOUTHERLY FLOW
OVERSPREADS THE REGION IN ADVANCE OF APPROACHING ARCTIC COLD
FRONT.
ALL MDL GUIDANCE INDICATES ARCTIC COLD FRONT WILL SWEEP THRU
CENTRAL PA BTWN 06Z-12Z. A BAND OF GUSTY RAIN SHOWERS ARE LIKELY
TO ACCOMPANY FROPA ALONG AXIS OF ANOMALOUS SOUTHERLY LL JET/PWATS.
ARRIVAL OF MUCH COLDER AIR WILL TURN THE SHRA TO SHSN OVR THE W
MTNS WITH A LIGHT ACCUM OF AN INCH OR SO POSSIBLE. THE WET
GROUND...COMBINED WITH RAPIDLY FALLING TEMPS BLW FREEZING...COULD
POTENTIALLY PRODUCE BLACK ICE/FLASH FREEZE CONDITIONS EARLY MON
AM. LATER SHIFTS MAY NEED TO CONSIDER POSSIBLE WINT WX ADV.
STRONG CAA WILL CAUSE TEMPS TO BUCK THE TYPICAL DIURNAL TREND WITH
FALLING TEMPS THRU THE DAY. BY EARLY MONDAY EVENING...GEFS ENS
MEAN 8H TEMPS FALL TO -26C...CLOSE TO 3SD BLW NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AIR MASS AS DEFINED BY 8H TEMPS COULD BE THE COLDEST THIS
REGION HAS SEEN IN 20 YEARS. BY TUES AM...THE CORE OF THE COLD
SHOULD LIE ACROSS SOUTHWEST PA...WHERE GEFS ENS MEAN 8H TEMPS FALL
TO -30C. THE FRIGID TEMPS...COMBINED WITH WGUSTS ARND 30KTS MON
NIGHT THRU TUESDAY WILL RESULT IN EXTREMELY DANGEROUS
CONDITIONS...MAKING FROSTBITE AND HYPOTHERMIA A REAL CONCERN EVEN
IF EXPOSED TO THE ELEMENTS FOR ONLY A SHORT PERIOD. HAVE EXPANDED
THE WIND CHILL WATCH EASTWARD INTO THE RIDGE/VALLEY REGION...AS
CONFIDENCE INCREASES THAT WARNING CRITERIA OF 25 BLW WILL BE
REACHED. ALTHOUGH IT APPEARS UNLIKELY WE WILL RIVAL THE MIN TEMPS
OF 1994...WIND CHILLS MAY BE AS COLD OR COLDER AS TIGHT PRES
GRADIENT CONTINUES TO BUFFET THE AREA WITH GUSTS NR 30KTS INTO TUE
EVENING.
SIG LAKE EFFECT DOES NOT APPEAR TO BE A CONCERN...AS MDL DATA
INDICATES BLYR FLOW WILL KEEP SNOW SHOWERS NORTH OF THE BORDER
MON-WED. WEDNESDAY MORNING WILL ALSO BE VERY COLD...AS WINDS
SLACKEN UPON ARRIVAL OF SFC HIGH. MODEL CONSENSUS SUPPORTS TEMPS
SLOWLY MODERATING BACK TOWARDS NORMAL BY THE SECOND HALF OF THE
WEEK. A LIGHT OVERRUNNING SNOWFALL IS POSSIBLE LATE WEEK...AS
WARMER SW FLOW TRIES TO DISLODGE LINGERING LOW LVL CHILL ACROSS
THE NORTHEAST CONUS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
MAIN CHANGE TO THIS TAF PACKAGE IS TO DELAY BY SEVERAL HOURS THE
ONSET OF LIGHT PRECIP AND LOWERING CIGS FOR MUCH OF THE AREA
TODAY.
WEAK DISTURBANCE SLIDING NORTHWARD THROUGH THE MID ATLANTIC REGION
WILL PUSH LOW CLOUDS INTO CENTRAL PA FROM THE SOUTH THIS
MORNING...WITH KLNS-KMDT-KJST DROPPING TO MVFR BY MID MORNING.
A SWATH OF LIGHT FREEZING RA/DZ WILL ALSO DEVELOP OVER THE LOWER
SUSQ DURING THE MID MORNING HOURS - PRODUCING SOME ICING
CONDITIONS. AS SYSTEM LIFTS FURTHER NORTH THIS AFTERNOON...THE
LOWER CIGS AND LIGHT FREEZING RAIN WILL IMPACT CENTRAL TERMINALS
AS WELL.
BY EARLY EVENING...DEEP SOUTHERLY FLOW FINALLY SCOURS OUT THE LOWER
LEVELS AND WARMS TEMPS UP ENOUGH TO CHANGE PRECIP OVER TO PLAIN RAIN
FOR MAJORITY OF CENTRAL PA LOCATIONS...BUT CIGS WILL CONTINUE TO
LOWER TO IFR AS SYNOPTIC LIFT INCREASES WITH ARRIVAL OF DEEPENING
LOW PRESSURE FROM THE OHIO VALLEY. THE WARMER AIR MOVING OVER THE
SNOWPACK IN THE EAST WILL LIKELY GENERATE AN AREA OF THICKER FOG
REDUCING VSBYS BELOW A MILE. LLWS INCLUDED IN TAFS AS 850 MB JET
INCREASES TO 40-60 KTS.
MODEL GUIDANCE INDICATES ARCTIC COLD FRONT WILL SWEEP THRU
CENTRAL PA BETWEEN 06Z-12Z. A BAND OF GUSTY RAIN SHOWERS ARE
LIKELY TO ACCOMPANY FROPA ALONG AXIS OF ANOMALOUS SOUTHERLY LL
JET/PWATS. ARRIVAL OF MUCH COLDER AIR WILL TURN THE SHRA TO SHSN
OVR THE W MTNS AND BEGIN A PERIOD OF STRONG AND GUSTY WESTERLY
WINDS.
OUTLOOK...
MON...RESTRICTIONS IN THE MORNING...THEN IMPROVING CIGS /ESP SE
HALF/ AS STRONG WESTERLY WINDS DEVELOP.
TUE...SCT SNOW SHOWERS NW. VFR ELSEWHERE. WINDY.
WED...SCT SNOW SHOWERS NW. VFR ELSEWHERE.
THU...MVFR TO IFR WITH CHC LIGHT SNOW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
THIS EVENING FOR PAZ012-018-019-026>028-041-042-045-046-
049>053.
WIND CHILL WATCH FROM LATE MONDAY NIGHT THROUGH WEDNESDAY
MORNING FOR PAZ012-018-019-025-026-034-035-037-041-042.
WIND CHILL WATCH FROM MONDAY AFTERNOON THROUGH WEDNESDAY
MORNING FOR PAZ004>006-010-011-017-024-033.
FREEZING RAIN ADVISORY FROM 10 AM THIS MORNING TO 7 PM EST
THIS EVENING FOR PAZ056>059-063.
FREEZING RAIN ADVISORY FROM 1 PM TO 4 PM EST THIS AFTERNOON
FOR PAZ035.
FREEZING RAIN ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
THIS EVENING FOR PAZ006-011-037.
FREEZING RAIN ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ064>066.
FREEZING RAIN ADVISORY FROM 10 AM THIS MORNING TO 4 PM EST
THIS AFTERNOON FOR PAZ036.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...RXR
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
621 AM EST SUN JAN 5 2014
.SYNOPSIS...
LOW PRESSURE WILL TRACK WEST OF PENNSYLVANIA LATER
TODAY. A TRAILING ARCTIC COLD FRONT WILL SWEEP THROUGH
PENNSYLVANIA EARLY MONDAY. UPPER LOW AND ASSOCIATED ARCTIC AIR
MASS WILL LIFT OUT OF THE AREA LATER NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BASED ON UPSTREAM OBS AND LATEST MDL OUTPUT...HAVE DELAYED ARRIVAL
OF RA/ZR ACROSS THE AREA TODAY. FZRA REPORTED AT KBWI AT 10Z AND
LATEST RAP SUGGESTS -FZRA COULD ENTER YORK/LANCASTER COS AFTER
12Z. WAA UNDERWAY EARLY THIS MORNING WITH 8H TEMPS ALREADY RISING
ABV 0C ACROSS SOUTHERN PA AT 10Z. MEANWHILE...SFC TEMPS IN THE
SINGLE DIGITS ACROSS MANY PARTS OF CENTRAL PA...CREATING A CLASSIC
FZRA SOUNDING PROFILE. EXPECT WARMER AIR TO EVENTUALLY WIN OUT BY
EARLY EVENING ACROSS THE EASTERN COUNTIES...AS WEAK SFC LOW
LIFTING UP THE COASTAL PLAIN TRACKS ACROSS EASTERN PA. PER WWD
GRAPHICS...EXPECT FZRA ACCRETION TO BE LESS THAN A TENTH OF AN
INCH...BUT ENOUGH TO CREATE POTENTIAL TRAVEL PROBLEMS.
BY EARLY EVENING...STEADIEST RAIN ASSOC WITH WEAK SFC LOW SHOULD
BE EXITING THE EASTERN COUNTIES. MEANWHILE...LIGHTER -DZ/-FZDZ
COULD LINGER OVR THE CENTRAL MTNS AND SUSQ VALLEY...WHERE SREF AND
NAM INDICATE A POCKET OF LINGERING SFC TEMPS NR 32F.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/...
BATCH OF PRECIP ASSOC WITH WEAK COASTAL LOW SHOULD BE EXITING
EASTERN PA EARLY THIS EVENING. MEANWHILE...PRIMARY SURFACE LOW WILL TRACK
WEST OF PA TONIGHT...KEEPING CENTRAL PA IN THE WARM SECTOR FOR MUCH
OF THE NIGHT. ANY POCKETS OF SUB-FREEZING AIR SHOULD BE SCOURED
OUT OF THE VALLEYS DURING THE EVENING...AS DEEP SOUTHERLY FLOW
OVERSPREADS THE REGION IN ADVANCE OF APPROACHING ARCTIC COLD
FRONT.
ALL MDL GUIDANCE INDICATES ARCTIC COLD FRONT WILL SWEEP THRU
CENTRAL PA BTWN 06Z-12Z. A BAND OF GUSTY RAIN SHOWERS ARE LIKELY
TO ACCOMPANY FROPA ALONG AXIS OF ANOMALOUS SOUTHERLY LL JET/PWATS.
ARRIVAL OF MUCH COLDER AIR WILL TURN THE SHRA TO SHSN OVR THE W
MTNS WITH A LIGHT ACCUM OF AN INCH OR SO POSSIBLE. THE WET
GROUND...COMBINED WITH RAPIDLY FALLING TEMPS BLW FREEZING...COULD
POTENTIALLY PRODUCE BLACK ICE/FLASH FREEZE CONDITIONS EARLY MON
AM. LATER SHIFTS MAY NEED TO CONSIDER POSSIBLE WINT WX ADV.
STRONG CAA WILL CAUSE TEMPS TO BUCK THE TYPICAL DIURNAL TREND WITH
FALLING TEMPS THRU THE DAY. BY EARLY MONDAY EVENING...GEFS ENS
MEAN 8H TEMPS FALL TO -26C...CLOSE TO 3SD BLW NORMAL.
&&
.LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
AIR MASS AS DEFINED BY 8H TEMPS COULD BE THE COLDEST THIS
REGION HAS SEEN IN 20 YEARS. BY TUES AM...THE CORE OF THE COLD
SHOULD LIE ACROSS SOUTHWEST PA...WHERE GEFS ENS MEAN 8H TEMPS FALL
TO -30C. THE FRIGID TEMPS...COMBINED WITH WGUSTS ARND 30KTS MON
NIGHT THRU TUESDAY WILL RESULT IN EXTREMELY DANGEROUS
CONDITIONS...MAKING FROSTBITE AND HYPOTHERMIA A REAL CONCERN EVEN
IF EXPOSED TO THE ELEMENTS FOR ONLY A SHORT PERIOD. HAVE EXPANDED
THE WIND CHILL WATCH EASTWARD INTO THE RIDGE/VALLEY REGION...AS
CONFIDENCE INCREASES THAT WARNING CRITERIA OF 25 BLW WILL BE
REACHED. ALTHOUGH IT APPEARS UNLIKELY WE WILL RIVAL THE MIN TEMPS
OF 1994...WIND CHILLS MAY BE AS COLD OR COLDER AS TIGHT PRES
GRADIENT CONTINUES TO BUFFET THE AREA WITH GUSTS NR 30KTS INTO TUE
EVENING.
SIG LAKE EFFECT DOES NOT APPEAR TO BE A CONCERN...AS MDL DATA
INDICATES BLYR FLOW WILL KEEP SNOW SHOWERS NORTH OF THE BORDER
MON-WED. WEDNESDAY MORNING WILL ALSO BE VERY COLD...AS WINDS
SLACKEN UPON ARRIVAL OF SFC HIGH. MODEL CONSENSUS SUPPORTS TEMPS
SLOWLY MODERATING BACK TOWARDS NORMAL BY THE SECOND HALF OF THE
WEEK. A LIGHT OVERRUNNING SNOWFALL IS POSSIBLE LATE WEEK...AS
WARMER SW FLOW TRIES TO DISLODGE LINGERING LOW LVL CHILL ACROSS
THE NORTHEAST CONUS.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS WILL PREVAIL FOR MOST OF THE NIGHT INTO EARLY
SUNDAY FOR MOST AREAS AS THE PRIMARY LOW PRESSURE SYSTEM
APPROACHES FROM THE WEST. A WEAKER SECONDARY WAVE WILL LIFT UP THE
COASTAL PLAIN TOMORROW. THIS SHOULD SPREAD MVFR CIGS INTO THE
LOWER SUSQ VALLEY SITES OF KLNS-KMDT BY 10Z AT THE EARLIEST BUT BY
16Z AT THE LATEST. EXPECT SOUTHERLY FLOW TO INCREASE AS THE DAY
WEARS ON...WITH LIGHT DRIZZLE/RAIN AND THEN LIGHT FZRA TO DEVELOP
AND SPREAD THROUGHOUT THE SOUTHEAST. THIS RAIN AND THEN FREEZING
RAIN WILL SLOWLY CREEP THROUGHOUT CENTRAL PA BY SUNDAY AFTERNOON
AND EVENING. AS MENTIONED IT COULD START AS -DZ OR PERHAPS -FZDZ
AND THEN SWITCH TO RAIN BETWEEN 21-03Z. THIS SHOULD LOWER VSBYS
AND HAVE LOWER CIGS TO MVFR TO IFR. N AS WELL...POTENTIALLY
LOWERING CIGS TO IFR THROUGH 06Z.
ANOTHER ISSUE IS A STRONG LOW LEVEL JET THAT WILL BE PROPAGATING
WITH THIS SYSTEM WITH WIND SHEAR AT 2KFT 170/40KTS POSSIBLE AT ALL
TAF SITES BETWEEN 22Z TO 07Z MONDAY.
OUTLOOK...
SUN...CLOUDS THICKEN AND LOWER...INITIALLY IN THE EAST BUT
AREA WIDE IN THE AFTERNOON. RAIN OR MIXED PRECIP BECOMING LIKELY.
MON...RESTRICTIONS IN THE MORNING...THEN IMPROVING CIGS /ESP SE
HALF/ AS STRONG WESTERLY WINDS DEVELOP.
TUE...SCT SNOW SHOWERS NW. VFR ELSEWHERE. WINDY.
WED...SCT SNOW SHOWERS NW. VFR ELSEWHERE.
THU...MVFR TO IFR WITH CHC LIGHT SNOW.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
FREEZING RAIN ADVISORY FROM 1 PM THIS AFTERNOON TO 7 PM EST
THIS EVENING FOR PAZ012-018-019-026>028-041-042-045-046-
049>053.
WIND CHILL WATCH FROM LATE MONDAY NIGHT THROUGH WEDNESDAY
MORNING FOR PAZ012-018-019-025-026-034-035-037-041-042.
WIND CHILL WATCH FROM MONDAY AFTERNOON THROUGH WEDNESDAY
MORNING FOR PAZ004>006-010-011-017-024-033.
FREEZING RAIN ADVISORY FROM 10 AM THIS MORNING TO 7 PM EST
THIS EVENING FOR PAZ056>059-063.
FREEZING RAIN ADVISORY FROM 1 PM TO 4 PM EST THIS AFTERNOON
FOR PAZ035.
FREEZING RAIN ADVISORY FROM 4 PM THIS AFTERNOON TO 7 PM EST
THIS EVENING FOR PAZ006-011-037.
FREEZING RAIN ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
PAZ064>066.
FREEZING RAIN ADVISORY FROM 10 AM THIS MORNING TO 4 PM EST
THIS AFTERNOON FOR PAZ036.
&&
$$
SYNOPSIS...FITZGERALD
NEAR TERM...FITZGERALD
SHORT TERM...FITZGERALD
LONG TERM...FITZGERALD
AVIATION...DEVOIR/CERU
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
103 PM EST SUN JAN 5 2014
.SYNOPSIS...
A VERY STRONG AND DEEP UPPER LEVEL TROUGH WILL SWING AN ARCTIC COLD
FRONT OVER THE REGION EARLY MONDAY AND USHER IN RECORD LEVEL COLD
TEMPERATURES FOR MONDAY NIGHT AND TUESDAY. THIS AIRMASS WILL SLOWLY
WARM BACK TO NORMAL LEVELS BY THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...FREEZING RAIN ADVISORY ALLOWED TO EXPIRE AS
TEMPS...AS WELL AS WET BULB TEMPS...ARE ABOVE FREEZING. SOME LIGHT
RAIN MAY FALL IN THE OLD ADVISORY AREA THRU MIDDAY.
915 AM UPDATE...A FEW PATCHES OF RAINFALL ARE SEEN ON RADAR AT THIS
HOUR OVER THE PIEDMONT AND NC FOOTHILLS. MOIST UPGLIDE CONTINUES TO
DRIVE THE PRECIP THOUGH CONVECTION IS PLAYING A SMALL ROLE AND
PROVIDING LOCALIZED ENHANCEMENT. PROG SOUNDINGS DO SUGGEST LESS THAN
100 J OF CAPE ABOVE INVERSION. THUNDER STILL A LONG SHOT WITH
PARCELS STRUGGLING TO REACH EVEN THE FREEZING LEVEL...BUT DID
INCLUDE SOME SUB-SCHC THUNDER CHANCES TODAY IN REVISED POPS...WHICH
ARE GENERALLY A BIT HIGHER THAN BEFORE. CONVECTION ALLOWING MODELS
STILL FAVOR THE ERN PIEDMONT...BUT DO FEATURE SOME SPRINKLES FURTHER
WEST. RAP AND 12Z NAM ARE MORE WIDESPREAD...INDICATING POPS ACRS THE
AREA OF UPGLIDE UNTIL TRENDING DOWN IN THE WEST THIS AFTN AS FLOW
TURNS MORE SWLY AND LESS WARM ADVECTIVE. I MAINTAINED A LULL IN THE
CENTRAL PORTION OF THE CWFA BETWEEN THE DIMINISHING UPGLIDE AND
STRENGTHENING FLOW AHEAD OF SYNOPTIC FORCING/FROPA TONIGHT. TEMPS
WERE TOO WARM PER NEWEST GUIDANCE...INCLUDING HOURLY SHORT TERM
MODELS...WHICH REFLECT THE PERSISTENT LOW STRATUS AND FOG TODAY.
HIGHS WERE GENERALLY LOWERED 3-5 DEGREES.
AS OF 300 AM...CURRENTLY UPGLIDE SHWRS/DRIZZLE CONTINUE TO EXPAND IN
COVERAGE ACRS SC AND THE NC PIEDMONT. MEANWHILE...NUMEROUS TEMP
SENSORS ARE HOVERING IN THE 30-32 DEG RANGE ACRS MUCH OF THE NC
FOOTHILLS AND NW PIEDMONT. GIVEN THE STRONGER RADAR RETURNS HEADING
TOWARD THE NC PIEDMONT...I PLAN TO EXPAND THE FREEZING RAIN ADVISORY
TO INCLUDE THE REST OF THE NC FOOTHILLS....AND ALL THE NW PIEDMONT.
I WILL HAVE IT GO TILL 15Z...THO TEMPS SHUD START WARMING ABV
FREEZING BEFORE THEN.
FOR TODAY...THE BAND OF MOIST UPGLIDE PRECIP SHUD SHIFT EAST OF THE
AREA BY LATE MORNING...WHILE THE NEXT BAND OF PRECIP ASSOCIATED WITH
APPROACHING ARCTIC COLD FRONT WILL STILL BE TO THE WEST. SO EXPECT A
LULL IN -RA/DZ FOR THE AFTN. HOWEVER...CLOUDS SHUD PERSIST...SAVE
FOR SOME OF THE BREAKS POSSIBLE IN SOME OF THE NC MTN VLYS DUE TO
STRONG SWLY DOWNSLOPE FLOW. TEMPS APPEAR TRICKY...AS COLD POOL WILL
LINGER EAST OF THE MTNS...BUT LACK OF PRECIP SHUD ALLOW SOME WARMING
AIDED BY STRONG WAA. FOR NOW...FORECASTING TEMPS TO RISE INTO THE
40S AS THE DAY WEARS ON.
TONIGHT...GUIDANCE HAS SLOWED DOWN TIMING OF STRONG ARCTIC FROPA
SLIGHTLY...BRINGING IT THRU THE CWFA BETWEEN MIDNIGHT AND 6 AM
MONDAY. A SWLY 50-60 KT LLJ WILL TRANSVERSE THE CWFA JUST AHEAD OF
THE FRONT. SO A BRIEF PERIOD OF STRONG WIND GUSTS WILL BE POSSIBLE
ALONG SOME OF THE RIDGES. HOWEVER...SHUD BE CONFINED IN AREA AND TOO
BRIEF TO WARRANT ANY HEADLINE FOR IT ATTM. OTHERWISE...POPS RAMP UP
TO LIKELY TO CATEGORICAL FOR A FEW HOURS OVERNIGHT. QPF LOOKS
LIGHT...GENERALLY UNDER 0.25" FOR MOST AREAS...EXCEPT 0.25-0.5"
ABOVE 3500 FT IN THE MTNS. SNOW LEVELS SHUD START TO FALL AROUND
MIDNIGHT TO VALLEY FLOORS BY 6 AM. EVEN SOME CHANGEOVER MAY OCCUR IN
THE NC FOOTHILLS BEFORE PRECIP TAPERS OFF. GIVEN A SLIGHTLY SLOWER
TIMING OF THE CAA...SNOW ACCUMS LOOK TO BE CONFINED MOSTLY TO ABOVE
3500 FT UNTIL CLOSE TO DAYBREAK...WHEN IT WILL START ACCUMULATING IN
THE VALLEYS. TEMPS ARE EXPECTED TO ALREADY BE IN THE TEENS TO MID
20S BY DAYBREAK IN THE MTNS. MEANWHILE...TEMPS WILL CONT TO RISE OR
HOLD STEADY WITH STRONG WAA AHEAD OF THE FRONT ACRS THE SOUTHEAST
CORNER OF THE CWFA...INCLUDING CHARLOTTE...WHERE SOME 50S MAY OCCUR
BEFORE FROPA. THERE DOESN/T LOOK TO BE ENUF INSTBY OR FORCING FOR
THUNDER.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 330 AM SUNDAY...NOT MUCH CHANGE FROM EARLIER THINKING WITH
REGARD TO THE IMPACTS ACROSS THE WESTERN CAROLINAS FROM THE PASSAGE
OF AN ARCTIC COLD FRONT MONDAY MORNING...SO IT IS TIME TO ACT.
STILL EXPECTING THE FRONT TO BE PUSHING EAST ACROSS THE PIEDMONT AT
SUNRISE MONDAY. PRECIPITATION SHOULD HAVE ALREADY CHANGED TO SNOW
ACROSS THE MTNS. E OF THE MTNS...LINGERING PRECIP COULD CHANGE OVER
TO A BRIEF PERIOD OF SNOW SHOWERS OR FLURRIES BEFORE ENDING MID
MORNING...AS COLD AIR MOVES IN BEHIND FRONT...BUT NO SIGNIFICANT
ACCUM IS EXPECTED. TEMPS MAY FALL BRIEFLY...THEN STABILIZE OR RISE A
FEW DEGREES DURING LATE MORNING...BUT THEN STRONG COLD ADVECTION
WILL TAKE OVER AND TEMPS WILL FALL THROUGH THE AFTERNOON.
SNOW PRODUCTION WILL CONTINUE NEAR THE TN BORDER THROUGHOUT MONDAY
AS TEMPS FALL AND MOISTURE IS PUSHED UP THE W SIDE OF THE MTNS.
THERE ARE SOME MIXED SIGNALS AS TO WHAT THE POTENTIAL FOR
ACCUMULATION WILL BE. ON THE ONE HAND...THE MODELS FCST WEAK SFC
BASED CAPE UPSTREAM...BUT THE SURFACE MIGHT BE FREEZING BY MONDAY
AFTERNOON UPSTREAM...WHICH MIGHT CUT BACK ON MOISTURE FLUX FROM THE
GROUND. THERE SHOULD BE SOME MID LEVEL FORCING IN THE AFTERNOON AS
DPVA MOVES OVERHEAD...BUT THE 850MB WIND RETAINS A MORE WESTERLY
COMPONENT...WHICH ALSO DOES NOT ALLOW FOR A GREAT LAKES CONNECTION.
THESE MIGHT PROVE TO BE LIMITING FACTORS...SO THE POTENTIAL LOOKS TO
BE SOMEWHERE IN THE NEIGHBORHOOD OF 3-5 INCHES ON MTN PEAKS AND 2
INCHES IN THE VALLEYS. GIVEN THAT NEIGHBORING OFFICES ARE GOING WITH
A WARNING...THE BEST COURSE OF ACTION WILL BE TO ALSO GO WITH A
WINTER STORM WARNING FOR THE COUNTIES ALONG THE TN BORDER STARTING
AT MIDNIGHT AND RUNNING THROUGH 6 PM MONDAY. NOTE THAT ONLY THE
RIDGETOPS ARE LIKELY TO REACH WARNING CRITERIA ACCUMULATION...WHILE
THE VALLEYS WILL GET LESS SNOW...BUT THAT PERHAPS THE IMPACT OF
BLOWING SNOW AND VERY COLD TEMPS MIGHT MAKE IT DANGEROUS ENOUGH THAT
PUBLIC IMPACT JUSTIFIES THE WARNING.
THE ARCTIC AIR REALLY TAKES HOLD MONDAY NIGHT AND TUESDAY. TEMPS
WILL BE WELL BELOW NORMAL...LIKELY MORE THAN 20 DEGREES BELOW
NORMAL. THE GUIDANCE CONTINUES TO TREND COOLER WITH EACH RUN...SO
THE FCST LOWS ARE NOW SOLIDLY IN RECORD TERRITORY. WIND GUST
POTENTIAL MAY PEAK MONDAY EVENING AS THE SHORT WAVE PASSES THROUGH.
WIND CHILL VALUES WILL FALL THROUGH THE ADVISORY RANGE MONDAY
AFTERNOON ACROSS THE MTNS...AND BELOW WARNING CRITERIA AROUND SUNSET
MONDAY. FOR THAT REASON...A WIND CHILL WATCH WILL BE ISSUED FOR THE
MTNS AND HIGH ELEVATION FOOTHILL ZONES FOR MONDAY NIGHT THROUGH NOON
TUESDAY. VALUES MAY REACH ADVISORY CRITERIA OUTSIDE THE MTNS...SO AN
ADVISORY MAY BE ISSUED LATER TODAY. ON TUESDAY...HIGH TEMPS WILL
REMAIN IN THE TEENS TO LOWER 20S OVER THE MTNS. TEMPS WILL PROBABLY
STAY BELOW FREEZING OUTSIDE OF THE MTNS...WHICH WOULD BE REMARKABLE
WITH NO SNOW ON THE GROUND. GUIDANCE TEMPS WERE SLIGHTLY COOLER THAN
THE PREV FCST ONCE AGAIN...AND THIS TREND WAS FOLLOWED.
THE REST OF THE SHORT RANGE REMAINS QUIET. THE ARCTIC HIGH REMAINS
IN CONTROL THROUGH WEDNESDAY...WITH THE AIR MASS SLOWLY MODIFYING.
TEMPS WILL REMAIN RATHER COLD...ONLY NOT TO THE EXTREME WE WILL SEE
MONDAY NIGHT AND TUESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 300 AM EST SUNDAY...THE LATEST 00Z GFS/ECMWF AGREE THAT SWLY
FLOW ALOFT WILL PERSIST ACROSS THE REGION WED NIGHT INTO THU...WITH
A WEAK SOUTHERN STREAM UPPER SHORTWAVE PASSING OVERHEAD THU NIGHT
INTO EARLY FRI. THE ECMWF DEVELOPS UPPER RIDGING ACROSS THE REGION
FRI THRU EARLY SUN AS ANOTHER SOUTHERN STREAM UPPER SHORTWAVE TROUGH
EJECTS OUT OF THE DESERT SW AND REACHES WESTERN GULF.
MEANWHILE...THE FASTER GFS PUSHES THIS THROUGH INTO THE MISSISSIPPI
VALLEY BY SAT NIGHT AND MAINTAINS SWLY FLOW ALOFT ACROSS THE REGION.
AT THE SURFACE...MOIST RETURN FLOW WILL DEVELOP ACROSS THE REGION BY
WED NIGHT AS HIGH PRESSURE SLIDES OFF THE MID ATLANTIC COAST. WITH
INCREASING ISENTROPIC LIFT AND A PASSAGE OF UPPER SHORTWAVE ON
THU...LIGHT PRECIP WILL DEVELOP ACROSS THE REGION BY EARLY THU
AFTERNOON. PRECIP WILL BE MAINLY LIQUID THOUGH A BRIEF PERIOD OF
FREEZING RAIN IS POSSIBLE AT THE ONSET OF PRECIP. THE ECMWF THEN
DEVELOPS BROAD AREAS OF DRY HIGH PRESSURE ACROSS THE SE THU NIGHT
INTO SAT...WHILE THE GFS KEEPS THE HIGH OFF THE ATLANTIC COAST AND
SLOWLY PUSHES A COLD FRONT INTO THE TN VALLEY BY FRI NIGHT
MAINTAINING DEEP SOUTHERLY FLOW ACROSS THE REGION. THE GFS SLOWLY
PUSHES THE FRONT THROUGH THE REGION SAT NIGHT INTO SUN WITH A SERIES
OF SURFACE WAVES RIDING ALONG THE FRONT. USING A COMPROMISE BETWEEN
THE DRY ECMWF AND THE WET GFS...HAVE INHERITED SLIGHT CHANCE POPS ON
FRI AND LOWERED POPS FROM THE HIGH END CHANCE/LIKELY TO THE 30/40
PERCENT RANGE ON SAT. THANKS TO WELL ABOVE FREEZING TEMPS...PRECIP
WILL BE ALL LIQUID. TEMPS WILL START OUT AROUND 10-15 DEGREES BELOW
NORMAL ON THU AND QUICKLY WARM BACK UP TO NEAR NORMAL BY FRI.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AT KCLT...LIFR STRATUS ALREADY IN PLACE OVER THE REGION STANDS
LITTLE CHANCE OF IMPROVING THIS AFTN WITH CIRRUS DECK NOW SEEN
MOVING ABOVE IT ON IR SATELLITE. FURTHERMORE AMPLIFYING WARM UPGLIDE
WILL ONLY REINFORCE THE STRATUS GOING INTO THE EVENING...WITH SHOWER
CHANCES INCREASING AFTER SUNSET AND PEAKING JUST PRIOR TO COLD FROPA
JUST BEFORE DAYBREAK. LIFR CIGS WILL LAST UNTIL THE FROPA FOLLOWED
BY RELATIVELY FAST IMPROVEMENT TO VFR. VERTICAL THERMAL PROFILES AND
SFC TEMPS SUPPORT ALL RAIN...NO FZRA OR SN...WITH ARCTIC AIR NOT
PUSHING IN UNTIL AFTER PRECIP TAPERS OFF. EXCEPTIONALLY STRONG LOW
LEVEL JET WILL PRECEDE FRONT IN STRONG INVERSION OVER THE COOL SFC
LAYER. WILL CARRY LLWS AS A RESULT TONIGHT. SLY OVERNIGHT WINDS TURN
NW AND GUSTY BEHIND THE FRONT.
ELSEWHERE...MAIN DIFFERENCES FROM KCLT ARE IN FRONTAL TIMING...APART
FROM THE RA/SN CHANGEOVER OCCURRING IN THE MTNS AND FOOTHILLS. IFR
TO LIFR CIGS ARE LIKELY TO HANG ON AT MID-AFTERNOON LEVELS THRU MOST
OF TONIGHT. AS AT KCLT COLD AIR ARRIVES TOO LATE TO AFFECT PTYPE. IN
FACT...IGNORING KAVL...ANY SN WOULD BE VERY BRIEF AND UNWORTHY OF
TAF MENTION. AT KAVL AND ELSEWHERE IN THE MTNS THE SNOW WILL BE
PARTLY DUE TO UPSLOPE EFFECTS AND ACCUMULATION WILL MAINLY OCCUR
NEAR THE TENN BORDER. MVFR TO IFR VSBY COULD RESULT FROM ANY SNOW
HOWEVER. LLWS CARRIED AT ALL TERMINALS. WIND GUSTS POST FROPA WILL
BE MODEST AT BEST AT THE TAF SITES...HOWEVER STRONG GUSTS OF 30-40
KT LIKELY THRU 18Z IN HIGH TERRAIN.
OUTLOOK...NORTHWEST FLOW SNOW WILL CONTINUE IN THE MTNS MONDAY
CAUSING SOME PERIODIC RESTRICTIONS NEAR THE TENN BORDER. VERY COLD
AND DRY HIGH PRES SETTLES IN FOR TUESDAY AND WEDNESDAY. WINTRY
PRECIP MAY RETURN TO THE AREA WITH ANOTHER SYSTEM MOVING THRU THE
ERN US LATE IN THE WEEK.
CONFIDENCE TABLE...
18-24Z 00-06Z 06-12Z 12-18Z
KCLT MED 78% HIGH 91% HIGH 84% HIGH 83%
KGSP MED 75% HIGH 90% MED 76% HIGH 89%
KAVL MED 73% HIGH 88% MED 77% HIGH 83%
KHKY MED 78% HIGH 96% MED 76% HIGH 83%
KGMU MED 75% HIGH 91% MED 75% HIGH 89%
KAND MED 75% HIGH 86% MED 73% HIGH 83%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.CLIMATE...
RECORD LOW MINIMUM TEMPERATURES FOR TUESDAY JAN 7TH...
AVL... 3 IN 1879
CLT...12 IN 1884
GSP... 9 IN 1904
RECORD LOW MAXIMUM TEMPERATURES FOR TUESDAY JAN 7TH...
AVL...21 IN 1988
CLT...24 IN 1988
GSP...27 IN 1988
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WIND CHILL WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING
FOR NCZ033-048>053-058-059-062>065-501-503-505-507-509.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM EST MONDAY
FOR NCZ033-048>052-058.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...ARK/WIMBERLEY
SHORT TERM...PM
LONG TERM...JOH
AVIATION...WIMBERLEY
CLIMATE...ARK/PM
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
1002 AM EST SUN JAN 5 2014
.SYNOPSIS...
A VERY STRONG AND DEEP UPPER LEVEL TROUGH WILL SWING AN ARCTIC COLD
FRONT OVER THE REGION EARLY MONDAY AND USHER IN RECORD LEVEL COLD
TEMPERATURES FOR MONDAY NIGHT AND TUESDAY. THIS AIRMASS WILL SLOWLY
WARM BACK TO NORMAL LEVELS BY THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
1000 AM UPDATE...FREEZING RAIN ADVISORY ALLOWED TO EXPIRE AS
TEMPS...AS WELL AS WET BULB TEMPS...ARE ABOVE FREEZING. SOME LIGHT
RAIN MAY FALL IN THE OLD ADVISORY AREA THRU MIDDAY.
915 AM UPDATE...A FEW PATCHES OF RAINFALL ARE SEEN ON RADAR AT THIS
HOUR OVER THE PIEDMONT AND NC FOOTHILLS. MOIST UPGLIDE CONTINUES TO
DRIVE THE PRECIP THOUGH CONVECTION IS PLAYING A SMALL ROLE AND
PROVIDING LOCALIZED ENHANCEMENT. PROG SOUNDINGS DO SUGGEST LESS THAN
100 J OF CAPE ABOVE INVERSION. THUNDER STILL A LONG SHOT WITH
PARCELS STRUGGLING TO REACH EVEN THE FREEZING LEVEL...BUT DID
INCLUDE SOME SUB-SCHC THUNDER CHANCES TODAY IN REVISED POPS...WHICH
ARE GENERALLY A BIT HIGHER THAN BEFORE. CONVECTION ALLOWING MODELS
STILL FAVOR THE ERN PIEDMONT...BUT DO FEATURE SOME SPRINKLES FURTHER
WEST. RAP AND 12Z NAM ARE MORE WIDESPREAD...INDICATING POPS ACRS THE
AREA OF UPGLIDE UNTIL TRENDING DOWN IN THE WEST THIS AFTN AS FLOW
TURNS MORE SWLY AND LESS WARM ADVECTIVE. I MAINTAINED A LULL IN THE
CENTRAL PORTION OF THE CWFA BETWEEN THE DIMINISHING UPGLIDE AND
STRENGTHENING FLOW AHEAD OF SYNOPTIC FORCING/FROPA TONIGHT. TEMPS
WERE TOO WARM PER NEWEST GUIDANCE...INCLUDING HOURLY SHORT TERM
MODELS...WHICH REFLECT THE PERSISTENT LOW STRATUS AND FOG TODAY.
HIGHS WERE GENERALLY LOWERED 3-5 DEGREES.
AS OF 300 AM...CURRENTLY UPGLIDE SHWRS/DRIZZLE CONTINUE TO EXPAND IN
COVERAGE ACRS SC AND THE NC PIEDMONT. MEANWHILE...NUMEROUS TEMP
SENSORS ARE HOVERING IN THE 30-32 DEG RANGE ACRS MUCH OF THE NC
FOOTHILLS AND NW PIEDMONT. GIVEN THE STRONGER RADAR RETURNS HEADING
TOWARD THE NC PIEDMONT...I PLAN TO EXPAND THE FREEZING RAIN ADVISORY
TO INCLUDE THE REST OF THE NC FOOTHILLS....AND ALL THE NW PIEDMONT.
I WILL HAVE IT GO TILL 15Z...THO TEMPS SHUD START WARMING ABV
FREEZING BEFORE THEN.
FOR TODAY...THE BAND OF MOIST UPGLIDE PRECIP SHUD SHIFT EAST OF THE
AREA BY LATE MORNING...WHILE THE NEXT BAND OF PRECIP ASSOCIATED WITH
APPROACHING ARCTIC COLD FRONT WILL STILL BE TO THE WEST. SO EXPECT A
LULL IN -RA/DZ FOR THE AFTN. HOWEVER...CLOUDS SHUD PERSIST...SAVE
FOR SOME OF THE BREAKS POSSIBLE IN SOME OF THE NC MTN VLYS DUE TO
STRONG SWLY DOWNSLOPE FLOW. TEMPS APPEAR TRICKY...AS COLD POOL WILL
LINGER EAST OF THE MTNS...BUT LACK OF PRECIP SHUD ALLOW SOME WARMING
AIDED BY STRONG WAA. FOR NOW...FORECASTING TEMPS TO RISE INTO THE
40S AS THE DAY WEARS ON.
TONIGHT...GUIDANCE HAS SLOWED DOWN TIMING OF STRONG ARCTIC FROPA
SLIGHTLY...BRINGING IT THRU THE CWFA BETWEEN MIDNIGHT AND 6 AM
MONDAY. A SWLY 50-60 KT LLJ WILL TRANSVERSE THE CWFA JUST AHEAD OF
THE FRONT. SO A BRIEF PERIOD OF STRONG WIND GUSTS WILL BE POSSIBLE
ALONG SOME OF THE RIDGES. HOWEVER...SHUD BE CONFINED IN AREA AND TOO
BRIEF TO WARRANT ANY HEADLINE FOR IT ATTM. OTHERWISE...POPS RAMP UP
TO LIKELY TO CATEGORICAL FOR A FEW HOURS OVERNIGHT. QPF LOOKS
LIGHT...GENERALLY UNDER 0.25" FOR MOST AREAS...EXCEPT 0.25-0.5"
ABOVE 3500 FT IN THE MTNS. SNOW LEVELS SHUD START TO FALL AROUND
MIDNIGHT TO VALLEY FLOORS BY 6 AM. EVEN SOME CHANGEOVER MAY OCCUR IN
THE NC FOOTHILLS BEFORE PRECIP TAPERS OFF. GIVEN A SLIGHTLY SLOWER
TIMING OF THE CAA...SNOW ACCUMS LOOK TO BE CONFINED MOSTLY TO ABOVE
3500 FT UNTIL CLOSE TO DAYBREAK...WHEN IT WILL START ACCUMULATING IN
THE VALLEYS. TEMPS ARE EXPECTED TO ALREADY BE IN THE TEENS TO MID
20S BY DAYBREAK IN THE MTNS. MEANWHILE...TEMPS WILL CONT TO RISE OR
HOLD STEADY WITH STRONG WAA AHEAD OF THE FRONT ACRS THE SOUTHEAST
CORNER OF THE CWFA...INCLUDING CHARLOTTE...WHERE SOME 50S MAY OCCUR
BEFORE FROPA. THERE DOESN/T LOOK TO BE ENUF INSTBY OR FORCING FOR
THUNDER.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 330 AM SUNDAY...NOT MUCH CHANGE FROM EARLIER THINKING WITH
REGARD TO THE IMPACTS ACROSS THE WESTERN CAROLINAS FROM THE PASSAGE
OF AN ARCTIC COLD FRONT MONDAY MORNING...SO IT IS TIME TO ACT.
STILL EXPECTING THE FRONT TO BE PUSHING EAST ACROSS THE PIEDMONT AT
SUNRISE MONDAY. PRECIPITATION SHOULD HAVE ALREADY CHANGED TO SNOW
ACROSS THE MTNS. E OF THE MTNS...LINGERING PRECIP COULD CHANGE OVER
TO A BRIEF PERIOD OF SNOW SHOWERS OR FLURRIES BEFORE ENDING MID
MORNING...AS COLD AIR MOVES IN BEHIND FRONT...BUT NO SIGNIFICANT
ACCUM IS EXPECTED. TEMPS MAY FALL BRIEFLY...THEN STABILIZE OR RISE A
FEW DEGREES DURING LATE MORNING...BUT THEN STRONG COLD ADVECTION
WILL TAKE OVER AND TEMPS WILL FALL THROUGH THE AFTERNOON.
SNOW PRODUCTION WILL CONTINUE NEAR THE TN BORDER THROUGHOUT MONDAY
AS TEMPS FALL AND MOISTURE IS PUSHED UP THE W SIDE OF THE MTNS.
THERE ARE SOME MIXED SIGNALS AS TO WHAT THE POTENTIAL FOR
ACCUMULATION WILL BE. ON THE ONE HAND...THE MODELS FCST WEAK SFC
BASED CAPE UPSTREAM...BUT THE SURFACE MIGHT BE FREEZING BY MONDAY
AFTERNOON UPSTREAM...WHICH MIGHT CUT BACK ON MOISTURE FLUX FROM THE
GROUND. THERE SHOULD BE SOME MID LEVEL FORCING IN THE AFTERNOON AS
DPVA MOVES OVERHEAD...BUT THE 850MB WIND RETAINS A MORE WESTERLY
COMPONENT...WHICH ALSO DOES NOT ALLOW FOR A GREAT LAKES CONNECTION.
THESE MIGHT PROVE TO BE LIMITING FACTORS...SO THE POTENTIAL LOOKS TO
BE SOMEWHERE IN THE NEIGHBORHOOD OF 3-5 INCHES ON MTN PEAKS AND 2
INCHES IN THE VALLEYS. GIVEN THAT NEIGHBORING OFFICES ARE GOING WITH
A WARNING...THE BEST COURSE OF ACTION WILL BE TO ALSO GO WITH A
WINTER STORM WARNING FOR THE COUNTIES ALONG THE TN BORDER STARTING
AT MIDNIGHT AND RUNNING THROUGH 6 PM MONDAY. NOTE THAT ONLY THE
RIDGETOPS ARE LIKELY TO REACH WARNING CRITERIA ACCUMULATION...WHILE
THE VALLEYS WILL GET LESS SNOW...BUT THAT PERHAPS THE IMPACT OF
BLOWING SNOW AND VERY COLD TEMPS MIGHT MAKE IT DANGEROUS ENOUGH THAT
PUBLIC IMPACT JUSTIFIES THE WARNING.
THE ARCTIC AIR REALLY TAKES HOLD MONDAY NIGHT AND TUESDAY. TEMPS
WILL BE WELL BELOW NORMAL...LIKELY MORE THAN 20 DEGREES BELOW
NORMAL. THE GUIDANCE CONTINUES TO TREND COOLER WITH EACH RUN...SO
THE FCST LOWS ARE NOW SOLIDLY IN RECORD TERRITORY. WIND GUST
POTENTIAL MAY PEAK MONDAY EVENING AS THE SHORT WAVE PASSES THROUGH.
WIND CHILL VALUES WILL FALL THROUGH THE ADVISORY RANGE MONDAY
AFTERNOON ACROSS THE MTNS...AND BELOW WARNING CRITERIA AROUND SUNSET
MONDAY. FOR THAT REASON...A WIND CHILL WATCH WILL BE ISSUED FOR THE
MTNS AND HIGH ELEVATION FOOTHILL ZONES FOR MONDAY NIGHT THROUGH NOON
TUESDAY. VALUES MAY REACH ADVISORY CRITERIA OUTSIDE THE MTNS...SO AN
ADVISORY MAY BE ISSUED LATER TODAY. ON TUESDAY...HIGH TEMPS WILL
REMAIN IN THE TEENS TO LOWER 20S OVER THE MTNS. TEMPS WILL PROBABLY
STAY BELOW FREEZING OUTSIDE OF THE MTNS...WHICH WOULD BE REMARKABLE
WITH NO SNOW ON THE GROUND. GUIDANCE TEMPS WERE SLIGHTLY COOLER THAN
THE PREV FCST ONCE AGAIN...AND THIS TREND WAS FOLLOWED.
THE REST OF THE SHORT RANGE REMAINS QUIET. THE ARCTIC HIGH REMAINS
IN CONTROL THROUGH WEDNESDAY...WITH THE AIR MASS SLOWLY MODIFYING.
TEMPS WILL REMAIN RATHER COLD...ONLY NOT TO THE EXTREME WE WILL SEE
MONDAY NIGHT AND TUESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 300 AM EST SUNDAY...THE LATEST 00Z GFS/ECMWF AGREE THAT SWLY
FLOW ALOFT WILL PERSIST ACROSS THE REGION WED NIGHT INTO THU...WITH
A WEAK SOUTHERN STREAM UPPER SHORTWAVE PASSING OVERHEAD THU NIGHT
INTO EARLY FRI. THE ECMWF DEVELOPS UPPER RIDGING ACROSS THE REGION
FRI THRU EARLY SUN AS ANOTHER SOUTHERN STREAM UPPER SHORTWAVE TROUGH
EJECTS OUT OF THE DESERT SW AND REACHES WESTERN GULF.
MEANWHILE...THE FASTER GFS PUSHES THIS THROUGH INTO THE MISSISSIPPI
VALLEY BY SAT NIGHT AND MAINTAINS SWLY FLOW ALOFT ACROSS THE REGION.
AT THE SURFACE...MOIST RETURN FLOW WILL DEVELOP ACROSS THE REGION BY
WED NIGHT AS HIGH PRESSURE SLIDES OFF THE MID ATLANTIC COAST. WITH
INCREASING ISENTROPIC LIFT AND A PASSAGE OF UPPER SHORTWAVE ON
THU...LIGHT PRECIP WILL DEVELOP ACROSS THE REGION BY EARLY THU
AFTERNOON. PRECIP WILL BE MAINLY LIQUID THOUGH A BRIEF PERIOD OF
FREEZING RAIN IS POSSIBLE AT THE ONSET OF PRECIP. THE ECMWF THEN
DEVELOPS BROAD AREAS OF DRY HIGH PRESSURE ACROSS THE SE THU NIGHT
INTO SAT...WHILE THE GFS KEEPS THE HIGH OFF THE ATLANTIC COAST AND
SLOWLY PUSHES A COLD FRONT INTO THE TN VALLEY BY FRI NIGHT
MAINTAINING DEEP SOUTHERLY FLOW ACROSS THE REGION. THE GFS SLOWLY
PUSHES THE FRONT THROUGH THE REGION SAT NIGHT INTO SUN WITH A SERIES
OF SURFACE WAVES RIDING ALONG THE FRONT. USING A COMPROMISE BETWEEN
THE DRY ECMWF AND THE WET GFS...HAVE INHERITED SLIGHT CHANCE POPS ON
FRI AND LOWERED POPS FROM THE HIGH END CHANCE/LIKELY TO THE 30/40
PERCENT RANGE ON SAT. THANKS TO WELL ABOVE FREEZING TEMPS...PRECIP
WILL BE ALL LIQUID. TEMPS WILL START OUT AROUND 10-15 DEGREES BELOW
NORMAL ON THU AND QUICKLY WARM BACK UP TO NEAR NORMAL BY FRI.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT KCLT /15Z UPDATE/...PERSISTENT MOIST LLVL UPGLIDE WILL KEEP
LIFR/IFR CIGS THRU THE DAY. PATCHY -SHRA AND DZ WILL BE AROUND AT
LEAST THRU THE MORNING. IFR VSBY LIKELY THRU MIDDAY WITH SHOWERS
ONLY REINFORCING SFC SATURATION. GUIDANCE AGREES ON LITTLE
IMPROVEMENT IN CIGS DURING THE AFTN...THEN POSSIBLY LOWERING IN THE
200-300 FT RANGE THIS EVENING WITH DECREASING VSBY. THERE WILL ALSO
BE A STRONG LLJ OF 40-50 KTS ATOP A STRONG INVERSION ABOUT 2000 FT
AGL. SO HAVE ADDED LLWS STARTING AROUND 5Z UNTIL THE COLD FRONT
PASSES THRU BEFORE DAYBREAK MONDAY. RAIN LOOKS TO BE LIGHT WITH THE
COLD FRONT...BUT WILL INCLUDE PREVAILING -SHRA.
ELSEWHERE...ALL SITES LOOK TO BE IFR OR LIFR THRU MOST OF THE
PERIOD...UNTIL A STRONG COLD FRONT PUSHES THRU FROM WEST TO EAST
OVERNIGHT TONIGHT. THE MAIN EXCEPTION IS KAVL...WHERE GUIDANCE HINTS
THAT STRONG SWLY DOWNSLOPE WINDS MAY HELP SCOUR OUT SOME OF THE LOW
CLOUDS. WILL GO WITH MVFR FOR THIS AFTN THERE...BUT IT MAY EVEN GO
VFR BRIEFLY. BUT OTHERWISE...LOW STRATUS AND PATCHY -SHRA AND DZ
THRU THE DAY...WITH MOST PRECIP THIS MORNING...THEN AGAIN TONIGHT
WITH FRONT. THE TOUGHEST PART OF THE FCST IS VSBY...WITH METARS
CONTINUING TO DROP...AND POTENTIAL FOR A LOT MORE FOG AROUND TODAY
AND THIS EVENING. DENSE FOG LOOKS MOST LIKELY IF IT OCCURS TO BE
NEAR THE BLUE RIDGE AND ADJACENT FOOTHILLS...ESP THIS EVENING. THE
OTHER ISSUE TONIGHT WILL BE 40-50 KT JET ATOP A STRONG INVERSION.
HAVE ADDED MENTION OF LLWS.
OUTLOOK...CONDITIONS SHOULD IMPROVE QUICKLY TO VFR BY MIDDAY
MONDAY...BUT NORTHWEST FLOW SNOW WILL RETURN TO THE MTNS WITH GUSTY
NW WINDS DEVELOPING ACRS THE REGION. VERY COLD AND DRY HIGH PRES
SETTLES IN FOR TUESDAY AND WEDNESDAY... WITH WINTRY PRECIP POSSIBLY
RETURNING WITH ANOTHER FRONT ON THURSDAY.
CONFIDENCE TABLE...
15-21Z 21-03Z 03-09Z 09-15Z
KCLT MED 66% MED 77% HIGH 91% MED 70%
KGSP MED 70% HIGH 82% HIGH 89% MED 63%
KAVL MED 75% HIGH 84% MED 74% HIGH 83%
KHKY MED 61% HIGH 83% HIGH 85% MED 63%
KGMU MED 70% HIGH 80% HIGH 85% MED 63%
KAND MED 66% HIGH 86% HIGH 83% MED 63%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.CLIMATE...
RECORD LOW MINIMUM TEMPERATURES FOR TUESDAY JAN 7TH...
AVL... 3 IN 1879
CLT...12 IN 1884
GSP... 9 IN 1904
RECORD LOW MAXIMUM TEMPERATURES FOR TUESDAY JAN 7TH...
AVL...21 IN 1988
CLT...24 IN 1988
GSP...27 IN 1988
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WIND CHILL WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING
FOR NCZ033-048>053-058-059-062>065-501-503-505-507-509.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM EST MONDAY
FOR NCZ033-048>052-058.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...ARK/WIMBERLEY
SHORT TERM...PM
LONG TERM...JOH
AVIATION...ARK/WIMBERLEY
CLIMATE...
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
939 AM EST SUN JAN 5 2014
.SYNOPSIS...
A VERY STRONG AND DEEP UPPER LEVEL TROUGH WILL SWING AN ARCTIC COLD
FRONT OVER THE REGION EARLY MONDAY AND USHER IN RECORD LEVEL COLD
TEMPERATURES FOR MONDAY NIGHT AND TUESDAY. THIS AIRMASS WILL SLOWLY
WARM BACK TO NORMAL LEVELS BY THE END OF NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
915 AM UPDATE...A FEW PATCHES OF RAINFALL ARE SEEN ON RADAR AT THIS
HOUR OVER THE PIEDMONT AND NC FOOTHILLS. MOIST UPGLIDE CONTINUES TO
DRIVE THE PRECIP THOUGH CONVECTION IS PLAYING A SMALL ROLE AND
PROVIDING LOCALIZED ENHANCEMENT. PROG SOUNDINGS DO SUGGEST LESS THAN
100 J OF CAPE ABOVE INVERSION. THUNDER STILL A LONG SHOT WITH
PARCELS STRUGGLING TO REACH EVEN THE FREEZING LEVEL...BUT DID
INCLUDE SOME SUB-SCHC THUNDER CHANCES TODAY IN REVISED POPS...WHICH
ARE GENERALLY A BIT HIGHER THAN BEFORE. CONVECTION ALLOWING MODELS
STILL FAVOR THE ERN PIEDMONT...BUT DO FEATURE SOME SPRINKLES FURTHER
WEST. RAP AND 12Z NAM ARE MORE WIDESPREAD...INDICATING POPS ACRS THE
AREA OF UPGLIDE UNTIL TRENDING DOWN IN THE WEST THIS AFTN AS FLOW
TURNS MORE SWLY AND LESS WARM ADVECTIVE. I MAINTAINED A LULL IN THE
CENTRAL PORTION OF THE CWFA BETWEEN THE DIMINISHING UPGLIDE AND
STRENGTHENING FLOW AHEAD OF SYNOPTIC FORCING/FROPA TONIGHT. TEMPS
WERE TOO WARM PER NEWEST GUIDANCE...INCLUDING HOURLY SHORT TERM
MODELS...WHICH REFLECT THE PERSISTENT LOW STRATUS AND FOG TODAY.
HIGHS WERE GENERALLY LOWERED 3-5 DEGREES.
AS OF 300 AM...CURRENTLY UPGLIDE SHWRS/DRIZZLE CONTINUE TO EXPAND IN
COVERAGE ACRS SC AND THE NC PIEDMONT. MEANWHILE...NUMEROUS TEMP
SENSORS ARE HOVERING IN THE 30-32 DEG RANGE ACRS MUCH OF THE NC
FOOTHILLS AND NW PIEDMONT. GIVEN THE STRONGER RADAR RETURNS HEADING
TOWARD THE NC PIEDMONT...I PLAN TO EXPAND THE FREEZING RAIN ADVISORY
TO INCLUDE THE REST OF THE NC FOOTHILLS....AND ALL THE NW PIEDMONT.
I WILL HAVE IT GO TILL 15Z...THO TEMPS SHUD START WARMING ABV
FREEZING BEFORE THEN.
FOR TODAY...THE BAND OF MOIST UPGLIDE PRECIP SHUD SHIFT EAST OF THE
AREA BY LATE MORNING...WHILE THE NEXT BAND OF PRECIP ASSOCIATED WITH
APPROACHING ARCTIC COLD FRONT WILL STILL BE TO THE WEST. SO EXPECT A
LULL IN -RA/DZ FOR THE AFTN. HOWEVER...CLOUDS SHUD PERSIST...SAVE
FOR SOME OF THE BREAKS POSSIBLE IN SOME OF THE NC MTN VLYS DUE TO
STRONG SWLY DOWNSLOPE FLOW. TEMPS APPEAR TRICKY...AS COLD POOL WILL
LINGER EAST OF THE MTNS...BUT LACK OF PRECIP SHUD ALLOW SOME WARMING
AIDED BY STRONG WAA. FOR NOW...FORECASTING TEMPS TO RISE INTO THE
40S AS THE DAY WEARS ON.
TONIGHT...GUIDANCE HAS SLOWED DOWN TIMING OF STRONG ARCTIC FROPA
SLIGHTLY...BRINGING IT THRU THE CWFA BETWEEN MIDNIGHT AND 6 AM
MONDAY. A SWLY 50-60 KT LLJ WILL TRANSVERSE THE CWFA JUST AHEAD OF
THE FRONT. SO A BRIEF PERIOD OF STRONG WIND GUSTS WILL BE POSSIBLE
ALONG SOME OF THE RIDGES. HOWEVER...SHUD BE CONFINED IN AREA AND TOO
BRIEF TO WARRANT ANY HEADLINE FOR IT ATTM. OTHERWISE...POPS RAMP UP
TO LIKELY TO CATEGORICAL FOR A FEW HOURS OVERNIGHT. QPF LOOKS
LIGHT...GENERALLY UNDER 0.25" FOR MOST AREAS...EXCEPT 0.25-0.5"
ABOVE 3500 FT IN THE MTNS. SNOW LEVELS SHUD START TO FALL AROUND
MIDNIGHT TO VALLEY FLOORS BY 6 AM. EVEN SOME CHANGEOVER MAY OCCUR IN
THE NC FOOTHILLS BEFORE PRECIP TAPERS OFF. GIVEN A SLIGHTLY SLOWER
TIMING OF THE CAA...SNOW ACCUMS LOOK TO BE CONFINED MOSTLY TO ABOVE
3500 FT UNTIL CLOSE TO DAYBREAK...WHEN IT WILL START ACCUMULATING IN
THE VALLEYS. TEMPS ARE EXPECTED TO ALREADY BE IN THE TEENS TO MID
20S BY DAYBREAK IN THE MTNS. MEANWHILE...TEMPS WILL CONT TO RISE OR
HOLD STEADY WITH STRONG WAA AHEAD OF THE FRONT ACRS THE SOUTHEAST
CORNER OF THE CWFA...INCLUDING CHARLOTTE...WHERE SOME 50S MAY OCCUR
BEFORE FROPA. THERE DOESN/T LOOK TO BE ENUF INSTBY OR FORCING FOR
THUNDER.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY/...
AS OF 330 AM SUNDAY...NOT MUCH CHANGE FROM EARLIER THINKING WITH
REGARD TO THE IMPACTS ACROSS THE WESTERN CAROLINAS FROM THE PASSAGE
OF AN ARCTIC COLD FRONT MONDAY MORNING...SO IT IS TIME TO ACT.
STILL EXPECTING THE FRONT TO BE PUSHING EAST ACROSS THE PIEDMONT AT
SUNRISE MONDAY. PRECIPITATION SHOULD HAVE ALREADY CHANGED TO SNOW
ACROSS THE MTNS. E OF THE MTNS...LINGERING PRECIP COULD CHANGE OVER
TO A BRIEF PERIOD OF SNOW SHOWERS OR FLURRIES BEFORE ENDING MID
MORNING...AS COLD AIR MOVES IN BEHIND FRONT...BUT NO SIGNIFICANT
ACCUM IS EXPECTED. TEMPS MAY FALL BRIEFLY...THEN STABILIZE OR RISE A
FEW DEGREES DURING LATE MORNING...BUT THEN STRONG COLD ADVECTION
WILL TAKE OVER AND TEMPS WILL FALL THROUGH THE AFTERNOON.
SNOW PRODUCTION WILL CONTINUE NEAR THE TN BORDER THROUGHOUT MONDAY
AS TEMPS FALL AND MOISTURE IS PUSHED UP THE W SIDE OF THE MTNS.
THERE ARE SOME MIXED SIGNALS AS TO WHAT THE POTENTIAL FOR
ACCUMULATION WILL BE. ON THE ONE HAND...THE MODELS FCST WEAK SFC
BASED CAPE UPSTREAM...BUT THE SURFACE MIGHT BE FREEZING BY MONDAY
AFTERNOON UPSTREAM...WHICH MIGHT CUT BACK ON MOISTURE FLUX FROM THE
GROUND. THERE SHOULD BE SOME MID LEVEL FORCING IN THE AFTERNOON AS
DPVA MOVES OVERHEAD...BUT THE 850MB WIND RETAINS A MORE WESTERLY
COMPONENT...WHICH ALSO DOES NOT ALLOW FOR A GREAT LAKES CONNECTION.
THESE MIGHT PROVE TO BE LIMITING FACTORS...SO THE POTENTIAL LOOKS TO
BE SOMEWHERE IN THE NEIGHBORHOOD OF 3-5 INCHES ON MTN PEAKS AND 2
INCHES IN THE VALLEYS. GIVEN THAT NEIGHBORING OFFICES ARE GOING WITH
A WARNING...THE BEST COURSE OF ACTION WILL BE TO ALSO GO WITH A
WINTER STORM WARNING FOR THE COUNTIES ALONG THE TN BORDER STARTING
AT MIDNIGHT AND RUNNING THROUGH 6 PM MONDAY. NOTE THAT ONLY THE
RIDGETOPS ARE LIKELY TO REACH WARNING CRITERIA ACCUMULATION...WHILE
THE VALLEYS WILL GET LESS SNOW...BUT THAT PERHAPS THE IMPACT OF
BLOWING SNOW AND VERY COLD TEMPS MIGHT MAKE IT DANGEROUS ENOUGH THAT
PUBLIC IMPACT JUSTIFIES THE WARNING.
THE ARCTIC AIR REALLY TAKES HOLD MONDAY NIGHT AND TUESDAY. TEMPS
WILL BE WELL BELOW NORMAL...LIKELY MORE THAN 20 DEGREES BELOW
NORMAL. THE GUIDANCE CONTINUES TO TREND COOLER WITH EACH RUN...SO
THE FCST LOWS ARE NOW SOLIDLY IN RECORD TERRITORY. WIND GUST
POTENTIAL MAY PEAK MONDAY EVENING AS THE SHORT WAVE PASSES THROUGH.
WIND CHILL VALUES WILL FALL THROUGH THE ADVISORY RANGE MONDAY
AFTERNOON ACROSS THE MTNS...AND BELOW WARNING CRITERIA AROUND SUNSET
MONDAY. FOR THAT REASON...A WIND CHILL WATCH WILL BE ISSUED FOR THE
MTNS AND HIGH ELEVATION FOOTHILL ZONES FOR MONDAY NIGHT THROUGH NOON
TUESDAY. VALUES MAY REACH ADVISORY CRITERIA OUTSIDE THE MTNS...SO AN
ADVISORY MAY BE ISSUED LATER TODAY. ON TUESDAY...HIGH TEMPS WILL
REMAIN IN THE TEENS TO LOWER 20S OVER THE MTNS. TEMPS WILL PROBABLY
STAY BELOW FREEZING OUTSIDE OF THE MTNS...WHICH WOULD BE REMARKABLE
WITH NO SNOW ON THE GROUND. GUIDANCE TEMPS WERE SLIGHTLY COOLER THAN
THE PREV FCST ONCE AGAIN...AND THIS TREND WAS FOLLOWED.
THE REST OF THE SHORT RANGE REMAINS QUIET. THE ARCTIC HIGH REMAINS
IN CONTROL THROUGH WEDNESDAY...WITH THE AIR MASS SLOWLY MODIFYING.
TEMPS WILL REMAIN RATHER COLD...ONLY NOT TO THE EXTREME WE WILL SEE
MONDAY NIGHT AND TUESDAY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SATURDAY/...
AS OF 300 AM EST SUNDAY...THE LATEST 00Z GFS/ECMWF AGREE THAT SWLY
FLOW ALOFT WILL PERSIST ACROSS THE REGION WED NIGHT INTO THU...WITH
A WEAK SOUTHERN STREAM UPPER SHORTWAVE PASSING OVERHEAD THU NIGHT
INTO EARLY FRI. THE ECMWF DEVELOPS UPPER RIDGING ACROSS THE REGION
FRI THRU EARLY SUN AS ANOTHER SOUTHERN STREAM UPPER SHORTWAVE TROUGH
EJECTS OUT OF THE DESERT SW AND REACHES WESTERN GULF.
MEANWHILE...THE FASTER GFS PUSHES THIS THROUGH INTO THE MISSISSIPPI
VALLEY BY SAT NIGHT AND MAINTAINS SWLY FLOW ALOFT ACROSS THE REGION.
AT THE SURFACE...MOIST RETURN FLOW WILL DEVELOP ACROSS THE REGION BY
WED NIGHT AS HIGH PRESSURE SLIDES OFF THE MID ATLANTIC COAST. WITH
INCREASING ISENTROPIC LIFT AND A PASSAGE OF UPPER SHORTWAVE ON
THU...LIGHT PRECIP WILL DEVELOP ACROSS THE REGION BY EARLY THU
AFTERNOON. PRECIP WILL BE MAINLY LIQUID THOUGH A BRIEF PERIOD OF
FREEZING RAIN IS POSSIBLE AT THE ONSET OF PRECIP. THE ECMWF THEN
DEVELOPS BROAD AREAS OF DRY HIGH PRESSURE ACROSS THE SE THU NIGHT
INTO SAT...WHILE THE GFS KEEPS THE HIGH OFF THE ATLANTIC COAST AND
SLOWLY PUSHES A COLD FRONT INTO THE TN VALLEY BY FRI NIGHT
MAINTAINING DEEP SOUTHERLY FLOW ACROSS THE REGION. THE GFS SLOWLY
PUSHES THE FRONT THROUGH THE REGION SAT NIGHT INTO SUN WITH A SERIES
OF SURFACE WAVES RIDING ALONG THE FRONT. USING A COMPROMISE BETWEEN
THE DRY ECMWF AND THE WET GFS...HAVE INHERITED SLIGHT CHANCE POPS ON
FRI AND LOWERED POPS FROM THE HIGH END CHANCE/LIKELY TO THE 30/40
PERCENT RANGE ON SAT. THANKS TO WELL ABOVE FREEZING TEMPS...PRECIP
WILL BE ALL LIQUID. TEMPS WILL START OUT AROUND 10-15 DEGREES BELOW
NORMAL ON THU AND QUICKLY WARM BACK UP TO NEAR NORMAL BY FRI.
&&
.AVIATION /15Z SUNDAY THROUGH THURSDAY/...
AT KCLT /15Z UPDATE/...PERSISTENT MOIST LLVL UPGLIDE WILL KEEP
LIFR/IFR CIGS THRU THE DAY. PATCHY -SHRA AND DZ WILL BE AROUND AT
LEAST THRU THE MORNING. IFR VSBY LIKELY THRU MIDDAY WITH SHOWERS
ONLY REINFORCING SFC SATURATION. GUIDANCE AGREES ON LITTLE
IMPROVEMENT IN CIGS DURING THE AFTN...THEN POSSIBLY LOWERING IN THE
200-300 FT RANGE THIS EVENING WITH DECREASING VSBY. THERE WILL ALSO
BE A STRONG LLJ OF 40-50 KTS ATOP A STRONG INVERSION ABOUT 2000 FT
AGL. SO HAVE ADDED LLWS STARTING AROUND 5Z UNTIL THE COLD FRONT
PASSES THRU BEFORE DAYBREAK MONDAY. RAIN LOOKS TO BE LIGHT WITH THE
COLD FRONT...BUT WILL INCLUDE PREVAILING -SHRA.
ELSEWHERE...ALL SITES LOOK TO BE IFR OR LIFR THRU MOST OF THE
PERIOD...UNTIL A STRONG COLD FRONT PUSHES THRU FROM WEST TO EAST
OVERNIGHT TONIGHT. THE MAIN EXCEPTION IS KAVL...WHERE GUIDANCE HINTS
THAT STRONG SWLY DOWNSLOPE WINDS MAY HELP SCOUR OUT SOME OF THE LOW
CLOUDS. WILL GO WITH MVFR FOR THIS AFTN THERE...BUT IT MAY EVEN GO
VFR BRIEFLY. BUT OTHERWISE...LOW STRATUS AND PATCHY -SHRA AND DZ
THRU THE DAY...WITH MOST PRECIP THIS MORNING...THEN AGAIN TONIGHT
WITH FRONT. THE TOUGHEST PART OF THE FCST IS VSBY...WITH METARS
CONTINUING TO DROP...AND POTENTIAL FOR A LOT MORE FOG AROUND TODAY
AND THIS EVENING. DENSE FOG LOOKS MOST LIKELY IF IT OCCURS TO BE
NEAR THE BLUE RIDGE AND ADJACENT FOOTHILLS...ESP THIS EVENING. THE
OTHER ISSUE TONIGHT WILL BE 40-50 KT JET ATOP A STRONG INVERSION.
HAVE ADDED MENTION OF LLWS.
OUTLOOK...CONDITIONS SHOULD IMPROVE QUICKLY TO VFR BY MIDDAY
MONDAY...BUT NORTHWEST FLOW SNOW WILL RETURN TO THE MTNS WITH GUSTY
NW WINDS DEVELOPING ACRS THE REGION. VERY COLD AND DRY HIGH PRES
SETTLES IN FOR TUESDAY AND WEDNESDAY... WITH WINTRY PRECIP POSSIBLY
RETURNING WITH ANOTHER FRONT ON THURSDAY.
CONFIDENCE TABLE...
14-20Z 20-02Z 02-08Z 08-14Z
KCLT MED 78% MED 79% HIGH 95% HIGH 83%
KGSP MED 72% HIGH 93% HIGH 97% MED 70%
KAVL HIGH 80% HIGH 86% HIGH 82% MED 68%
KHKY MED 75% HIGH 92% HIGH 95% MED 66%
KGMU MED 73% HIGH 90% HIGH 95% MED 70%
KAND MED 75% HIGH 85% HIGH 84% MED 70%
THE PERCENTAGE REFLECTS THE NUMBER OF GUIDANCE MEMBERS AGREEING
WITH THE SCHEDULED TAF ISSUANCE FLIGHT RULE CATEGORY. COMPLETE
HOURLY EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLES AND ENSEMBLE
FORECASTS ARE AVAILABLE AT THE FOLLOWING LINK: (MUST BE LOWER CASE)
WWW.WEATHER.GOV/GSP/AVIATION_TABLES
&&
.CLIMATE...
RECORD LOW MINIMUM TEMPERATURES FOR TUESDAY JAN 7TH...
AVL... 3 IN 1879
CLT...12 IN 1884
GSP... 9 IN 1904
RECORD LOW MAXIMUM TEMPERATURES FOR TUESDAY JAN 7TH...
AVL...21 IN 1988
CLT...24 IN 1988
GSP...27 IN 1988
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 6 PM EST MONDAY
FOR NCZ033-048>052-058.
WIND CHILL WATCH FROM MONDAY EVENING THROUGH TUESDAY MORNING
FOR NCZ033-048>053-058-059-062>065-501-503-505-507-509.
FREEZING RAIN ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NCZ035>037-056-057-068-069-501>510.
SC...NONE.
&&
$$
SYNOPSIS...JOH
NEAR TERM...ARK/WIMBERLEY
SHORT TERM...PM
LONG TERM...JOH
AVIATION...ARK/WIMBERLEY
CLIMATE...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
110 PM EST SUN JAN 5 2014
.SYNOPSIS...
A WARM FRONT WILL APPROACH THE AREA FROM THE SOUTH TODAY...
SPREADING LIGHT RAIN ACROSS THE AREA MAINLY EAST OF THE BLUE RIDGE.
AN ARCTIC FRONT WILL ARRIVE LATE TONIGHT. ITS PASSAGE WILL BRING
SOME VERY COLD AIR TO OUR REGION WITH DANGEROUS WIND CHILLS. THIS
AIRMASS WILL LAST INTO TUESDAY...THEN SLOWLY MODERATE FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1205 PM EST SUNDAY...
CANCELLED THE FREEZING RAIN ADVISORY AS ALL TEMPERATURES FROM
REPORTING SITES HAVE RISEN TO ABOVE FREEZING...EXCEPT FOR A FEW
LOCATIONS WEST OF THE AREA OF LIGHT PRECIP THAT ARE RIGHT AT
FREEZING. ADJUSTED SOME HIGH TEMPS DOWN A BIT WITH WEAK WEDGE
CONTINUING ACROSS NORTHEAST PORTION OF THE AREA. ADJUSTED SOME MAX
TEMPS UPWARD IN FAR SOUTHWEST GIVEN CURRENT TEMPS. MINOR CHANGES
TO POPS REMAINDER OF AFTERNOON WITH HRRR AND RAP DOING BEST WITH
CURRENT AREA OF LIGHT RAIN AND HAVE TRIED TO INDICATE A ZONE OF
HIGHEST POPS CONTINUING JUST EAST OF BLUE RIDGE WITH LOWER POPS
FARTHER EAST BORDERING WAKEFIELD FCST AREA...AT LEAST UNTIL LATE
AFTERNOON BEFORE THIS ZONE FINALLY SHIFT EAST AND NORTH OUT OF THE
FCST AREA BY EARLY EVENING.
PREV DISCUSSION AS OF 1025 AM EST SUNDAY...
UPDATED TO CANCEL FREEZING RAIN ADV FOR MTNS OF NW NC AND UP THE
BLUE RIDGE TO FLOYD WHERE HIGHER ELEVATIONS ARE WELL ABOVE
FREEZING. STILL POCKETS OF SUB FREEZING TEMPS IN PARTS OF NEW
RIVER VALLEY WITH SOME GROUND TEMPS LIKELY TO STILL BE BELOW
FREEZING...AND THEN NORTHWARD INTO ROANOAKE VALLEY AND MUCH OF
FOOTHILLS AND PIEDMONT STILL HAVE POCKETS OF SUB FREEZING TEMPS.
THUS WILL KEEP THE ADVISORY GOING UNTIL NOON IN THOSE LOCATIONS.
MOST OF PRECIP HAS MOVED EAST OF BLUE RIDGE...BUT DRIZZLE STILL
POSSIBLE AND ONGOING SLICK SPOTS UNTIL ALL TEMPS HAVE RISEN ABOVE
FREEZING.
PREVIOUS DISCUSSION AS OF 830 AM EST SUNDAY...
NUMEROUS CALLS COMING INTO THE OFFICE THIS MORNING OF AUTO
ACCIDENTS CAUSED BY SLICK ROADS EAST OF THE BLUE RIDGE. GROUND
TEMPERATURES IN MANY AREAS WERE SIGNIFICANTLY CHILLED DURING THE
POLAR SURGE A COUPLE DAYS AGO...AND WITH AIR TEMPERATURES ACROSS
THE PIEDMONT HOVERING AROUND FREEZING...GIVE OR TAKE A DEGREE...
EXPECT ICING TO CONTINUE FOR THE NEXT FEW HOURS. EVEN AFTER AIR
TEMPERATURES WARM LATER THIS MORNING...EXPECT ICING ON THE GROUND
TO BE SLOW TO MELT. MOTORISTS SHOULD EXERCISE EXTREME CAUTION WHEN
TRAVELING THIS MORNING AS THE ICING WILL BE VERY DIFFICULT TO SEE
UNTIL THEY ARE ALREADY DRIVING ON IT. TO MAKE MATTERS WORSE...
SURFACE OBSERVATIONS ACROSS THE MOUNTAINS INDICATE VISIBILITIES
FOGGING DOWN AS MOIST AIR CONTINUES TO WORK IN FROM THE
SOUTHWEST. EXPECT THESE CONDITIONS TO BE SLOW TO IMPROVE THROUGH
THE DAY.
WAVES OF LIGHT RAIN WILL PASS ACROSS THE REGION THROUGH THE DAY
AS MINOR DISTURBANCES EMBEDDED IN THE SOUTHWESTERLY FLOW ALOFT
MOVE ACROSS THE CENTRAL APPALACHIAN CHAIN. BELIEVE THAT THE LIGHT
RAIN WILL LIMIT HEATING ACROSS THE EAST AND HAVE THEREFORE HELD
HIGHS A LITTLE BELOW GUIDANCE...NAMELY THE UPPER 30S AND THE LOW
40S. RAINFALL WILL NOT BE AS WIDESPREAD ACROSS THE MOUNTAINS...AND
EXPECT TO SEE MID AND UPPER 40S THIS AFTERNOON.
ALL OF THIS WARM AIR IS FLOWING IN AHEAD OF OUR NEXT STRONG COLD
FRONT...EXPECTED TO ENTER THE REGION SHORTLY AFTER MIDNIGHT. THE
FRONT WILL SHIFT EAST VERY RAPIDLY...EXITING OUR AREA BEFORE
SUNRISE. WITH PRECIPITABLE WATER VALUES RISING TO AROUND AN INCH
BY MIDNIGHT...BELIEVE ALL LOCATIONS WILL SEE A BRIEF SHOT RAIN AS
THE FRONT PASSES. RAIN WILL CHANGE VERY RAPIDLY TO SNOW AS
TEMPERATURES DROP BEHIND THE FRONT...WITH SNOW ACCUMULATING
ACROSS THE WESTERN RIDGES THROUGH THE NIGHT.
THE GREATEST IMPACTS OF THE COLD FRONT WILL BE FELT ALONG THE
WESTERN MOST COUNTIES FROM GREENBRIER TO WATAUGA. HIGHEST
SNOWFALL ACCUMULATIONS WILL OCCUR IN WESTERN GREENBRIER AND
NORTHERN SUMMERS COUNTIES...WHERE LOCALLY 6 TO 9 INCHES ARE POSSIBLE
THROUGH MONDAY MORNING. LESSER AMOUNTS OF 2 TO LOCALLY 5 INCHES
ARE POSSIBLE ACROSS THE WEST FACING SLOPES IN THE MOUNTAIN EMPIRE
AND NORTHERN NORTH CAROLINA. GUSTY WINDS BEHIND THE FRONT WILL
RESULT IN BLOWING SNOW AND POSSIBLY WHITE OUT CONDITIONS THAT MAY
PERSIST INTO THE MONDAY MORNING COMMUTE. IN ADDITION...THE COLD
AIR WILL LIKELY RESULT IN FLASH FREEZING OF WET SURFACES FROM
RAINFALL EARLIER IN THE EVENING...MAKING FOR SLICK ROADWAYS.
AS A RESULT...HAVE ISSUED A WINTER STORM WARNING FOR OUR WESTERN
MOST COUNTIES...AND A WIND ADVISORY FOR ALL OF OUR MOUNTAIN
COUNTIES...BEGINNING AT MIDNIGHT TONIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 545 AM EST SATURDAY...
BY THE BEGINNING OF THIS PERIOD WE WILL BE FIRMLY ENTRENCHED IN
THE THRAWLS OF AN INTENSE ARCTIC AIR MASS THAT PROMISES TO BRING
SOME OF THE COLDEST TEMPERATURES IN A COUPLE OF DECADES ALONG WITH
DANGEROUSLY COLD WIND CHILLS. ALTHOUGH THE BULK OF SYNOPTICALLY
DRIVEN PCPN WILL BE ENDING DURING THIS TIME FRAME...UPSLOPE SNOW
SHOWERS WILL MOST CERTAINLY CONTINUE GIVEN STRENGTH OF CAA. IN
FACT...FEELS MODELS ARE WAY TO QUICK IN ENDING SHSN...AND HAVE
EXTENDED WELL BEYOND THE MODEL INDICATIONS OF 18Z MON...ALL THE
WAY TO EARLY TUESDAY MORNING. GRANTED...THE MOST SIGNIFICANT
SNOWFALL WILL END BY 18Z MON...BUT EXPECT SHSN TO CONTINUE IN
EARNEST ALONG WEST FACING SLOPES WITH ADDITIONAL ACCUMULATIONS OF
ANOTHER INCH OR TWO POSSIBLE IN THIS TIME FRAME. THUS...THE SNOW
PORTION OF THE WINTER STORM WARNING WILL REMAIN IN EFFECT UNTIL
00Z TUE.
WIND CHILL WILL PERHAPS BE THE MOST SIGNIFICANT ISSUE WITH THIS
EVENT...WITH DANGEROUSLY COLD -20 TO -40F WIND CHILLS IN PLACE
OVERNIGHT MONDAY INTO THE FIRST HALF OF THE DAY TUE. HAVE UPGRADED
THE WIND CHILL WATCH TO A WIND CHILL WARNING WITH THIS PACKAGE AND
ALSO INCLUDED A WIND CHILL ADVISORY FOR THE REMAINDER OF THE
CWA...GENERALLY EAST OF I-81 AND I-77...PRINCIPALLY THE PIEDMONT.
SUSTAINED WINDS SHOULD REMAIN MOSTLY IN THE 15 TO 30 MPH RANGE
LATE TONIGHT THROUGH EARLY TUE...BUT GUSTS OF 45 TO 50 MPH CAN BE
EXPECTED IN THE HIGHER ELEVATIONS OF THE ALLEGHANYS AND BLUE
RIDGE. THIS SPEEDS DO NOT MEET HIGH WIND WARNING CRITERIA...SO
HAVE SIMPLY GONE WITH A WIND ADVISORY AT THIS POINT.
A STRONG NON-DIURNAL TEMPERATURE TREND IS EXPECTED MON...WITH
TEMPERATURES CONTINUING TO PLUNGE UNTIL EARLY TUE. BY TUE
MORNING...THE WESTERN PARTS OF THE CWA WILL BE WELL BELOW
ZERO...WITH -20F POSSIBLE IN NW GREENBRIER EARLY TUE...GENERALLY 0
TO -10F ELSEWHERE THROUGH THE ALLEGHANYS TO THE SINGLE DIGITS
ACROSS THE PIEDMONT. HAVE FAVORED THE COLDER ECMWF MOS FOR MINS
THROUGH THE PERIOD WITH THE COLDER MEX MOS FOR MAXS THROUGH THE
PERIOD. THE ARCTIC HIGH WILL BE CENTERED RIGHT OVER THE CWA AT 12Z
WED...SO ONLY A SLOW MODERATION IN TEMPERATURES ARE EXPECTED WED
AS THE -30C AIR AT 850MB FINALLY LIFTS OUT OF THE CWA.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AS OF 200 PM EST SATURDAY...
DURING THIS PORTION OF THE FORECAST...THE WEATHER PATTERN ACROSS OUR
REGION WILL TRANSITION TO ONE DOMINATED MORE BY THE SOUTHERN STREAM
OF THE JET STREAM RATHER THAN THE NORTHERN STREAM. WITHIN THIS
PATTERN WILL BE A SERIES OF FAST MOVING DISTURBANCES...EACH WITH THE
POTENTIAL TO BRING SOME LIGHT PRECIPITATION TO PARTS OR ALL OF THE
FORECAST AREA. SPECIFICALLY...WE ARE EXPECTING A SYSTEM THURSDAY
AFTERNOON AND THURSDAY NIGHT TO IMPACT MAINLY THE WESTERN PARTS OF
THE REGION. ONE FRIDAY INTO FRIDAY NIGHT MAY SKIRT THE FAR WESTERN
PART OF THE REGION. FINALLY...ONE LATE FRIDAY NIGHT THROUGH SATURDAY
HAS THE POTENTIAL OF BRINING RAIN TO ALL OF THE REGION.
EACH DAY...TEMPERATURES WILL TREND MILDER SO THAT BY SATURDAY HIGH
TEMPERATURES ARE FORECAST IN THE LOWER 50S ACROSS THE MOUNTAINS WITH
MID TO UPPER 50S ACROSS THE PIEDMONT. MOST OF THE PRECIPITATION
ASSOCIATED WITH THE DISTURBANCES WILL BE IN THE FORM OF RAIN. ENOUGH
COLD AIR WILL STILL BE AROUND THURSDAY NIGHT INTO FRIDAY FOR SOME
POCKETS OF FREEZING RAIN.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 105 PM EST SUNDAY...
THIS AFTERNOON THE FCST AREA REMAINS IN A SHALLOW WEDGE AND MOIST
AIRMASS JUST NORTH OF SFC WARM FRONT...WITH AREAS OF LIGHT RAIN
PERSISTING MAINLY EAST OF BCB/ROA...ALTHOUGH CANT RULE OUT A
SPRINKLE OR BRIEF PERIOD OF DRIZZLE THERE AS WELL. MAIN STORY FOR
ALL AIRPORTS IS IFR CIGS AND FOR DAN AND LYH WITH BEST CHC FOR
LIGHT RAIN...EVEN LIFR CIFS AND VSBYS THROUGH REST OF AFTERNOON AT
THOSE TWO AIRPORTS. CHC FOR SOME VFR CIGS AT LWB AND BLF THIS
AFTERNOON..BUT BLV PREVAILING WILL BE IFR CIGS REMAINDER OF DAY. IFR
CONDITIONS MAY NOT BREAK AT ALL FOR BCB/ROA/LYH/DAN BEFORE COLD
FRONT ARRIVES LATE TONIGHT.
THE COLD FRONT WILL ENTER THE REGION BETWEEN 07 UTC AND 10 UTC TONIGHT.
A FEW SCATTERED SHOWERS ALONG AND AHEAD OF THE FRONT WILL QUICKLY
TRANSITION TO SNOW AFTER THE FRONT PASSES...WITH REDUCED VSBYS IN
SNOW MAINLY AT BLF...WITH BRIEFLY LOWER VSBYS AT BCB AND LWB. VERY
COLD AIR WILL ARRIVE BEHIND THE FRONT...WHICH COULD CAUSE FLASH
FREEZING OF WET SURFACES FROM RAINFALL EARLIER IN THE EVENING.
WHILE SNOW SHOWERS WILL NOT PERSIST AS LONG FOR ROA DAN AND LYH.
EXPECT THE CHANGE OVER TO SNOW AROUND 06/08Z AT BLF AND
LWB...06/09Z FOR BCB AND ROA...AND 06/10Z FOR LYH AND DAN.
ACCUMULATIONS OF AROUND 4 INCHES ARE POSSIBLE FOR BLF...AN INCH OR
TWO AT LWB...AND LESS THAN AN INCH FOR ROA AND BCB. STRONG WINDS
FROM THE NORTHWEST WILL ACCOMPANY THE FRONT...WITH OCCASIONAL 35
TO 40 KT GUSTS EXPECTED ACROSS THE MOUNTAINS. STRONG CROSS-
BARRIER FLOW WILL ALSO RESULT IN MODERATE TURBULENCE. IFR
CONDITIONS MAY PERSIST THROUGH THE DAY MONDAY AT BLF IN SNOW
SHOWERS. ELSEWHERE...VFR CIGS AND VSBYS WILL RETURN DURING THE DAY
MONDAY...BUT WITH CONTINUED STRONG AND GUSTY NW WINDS.
WHILE WINDS WILL DIMINISH SOMEWHAT ON MONDAY AFTERNOON...A
SECONDARY SHOT OF ARCTIC AIR WILL ARRIVE MONDAY NIGHT...CAUSING
WIND SPEEDS TO INCREASE ONCE AGAIN. THIS ARCTIC AIR WILL CAUSE
TEMPERATURES TO FALL INTO THE POSITIVE SINGLE DIGITS EAST OF THE
BLUE RIDGE...AND FALL BELOW ZERO TO THE WEST. SNOW SHOWERS WILL
PERSIST ACROSS THE MOUNTAINS THROUGH TUESDAY MORNING...BEFORE
HIGH PRESSURE SETTLES IN...CAUSING WIND SPEEDS AND SNOW SHOWERS TO
DECREASE.
HIGH PRESSURE WILL RETURN BY TUES NIGHT AND WEDNESDAY WITH VFR
CONDITIONS AND MILDER TEMPERATURES...WITH THE NEXT WEATHER SYSTEM
EXPECTED BY LATE IN THE WEEK.
&&
.CLIMATE...
AS OF 220 PM EST THURSDAY...
FORECAST LOW TEMPERATURES MONDAY NIGHT...EARLY JAN 7...ARE
FORECAST TO BE AROUND ZERO OR A BIT BELOW ZERO ACROSS THE
MOUNTAINS AND IN THE SINGLE DIGITS TO NEAR 15 ACROSS THE PIEDMONT.
OF OUR CLIMATE SITES...ALL BUT DANVILLE IS FORECAST TO BREAK THE
RECORD. HIGH TEMPERATURES ON TUESDAY JANUARY 7 ARE FORECAST TO BE
IN THE TEENS ACROSS THE MOUNTAINS AND LOW TO MID 20S ACROSS THE
PIEDMONT. OUR CURRENT FORECAST PLACES THE RECORD MINIMUM HIGH
TEMPERATURE RECORDS IN JEOPARDY AT BOTH BLACKSBURG AND LEWISBURG
WHILE THE OTHER LOCATION WILL SEE TEMPERATURES WITHIN A FEW
DEGREES OF THE RECORDS.
JANUARY 7 RECORDS
LOWS MINIMUM HIGHS
BLACKSBURG VA... 1/1988 19/1988
BLUEFIELD WV.... 0/1970 11/1988
DANVILLE VA..... 10/1969 26/1988
ROANOKE VA...... 8/1970 17/1988
LEWISBURG WV.... 7/2004 11/1988
LYNCHBURG VA.... 10/1912 17/1988
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST TUESDAY FOR
VAZ007-009>020-022>024.
WIND CHILL WARNING FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
VAZ007-009>020-022>024.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 7 PM EST MONDAY
FOR VAZ007-009-015.
WIND CHILL ADVISORY FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
VAZ032>035-043>047-058-059.
NC...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST TUESDAY FOR
NCZ001-002-018.
WIND CHILL WARNING FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
NCZ001-002-018.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 7 PM EST MONDAY
FOR NCZ001-018.
WIND CHILL ADVISORY FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
NCZ003>006-019-020.
WV...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST TUESDAY FOR
WVZ042>045.
WIND CHILL WARNING FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
WVZ042>045.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 7 PM EST MONDAY
FOR WVZ042-043-045.
&&
$$
SYNOPSIS...NF/SK
NEAR TERM...NF/SK
SHORT TERM...RAB
LONG TERM...DS
AVIATION...NF/PM/SK
CLIMATE...DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1207 PM EST SUN JAN 5 2014
.SYNOPSIS...
A WARM FRONT WILL APPROACH THE AREA FROM THE SOUTH TODAY...
SPREADING LIGHT RAIN ACROSS THE AREA MAINLY EAST OF THE BLUE RIDGE.
AN ARCTIC FRONT WILL ARRIVE LATE TONIGHT. ITS PASSAGE WILL BRING
SOME VERY COLD AIR TO OUR REGION WITH DANGEROUS WIND CHILLS. THIS
AIRMASS WILL LAST INTO TUESDAY...THEN SLOWLY MODERATE FOR THE
SECOND HALF OF THE WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1205 PM EST SUNDAY...
CANCELLED THE FREEZING RAIN ADVISORY AS ALL TEMPERATURES FROM
REPORTING SITES HAVE RISEN TO ABOVE FREEZING...EXCEPT FOR A FEW
LOCATIONS WEST OF THE AREA OF LIGHT PRECIP THAT ARE RIGHT AT
FREEZING. ADJUSTED SOME HIGH TEMPS DOWN A BIT WITH WEAK WEDGE
CONTINUING ACROSS NORTHEAST PORTION OF THE AREA. ADJUSTED SOME MAX
TEMPS UPWARD IN FAR SOUTHWEST GIVEN CURRENT TEMPS. MINOR CHANGES
TO POPS REMAINDER OF AFTERNOON WITH HRRR AND RAP DOING BEST WITH
CURRENT AREA OF LIGHT RAIN AND HAVE TRIED TO INDICATE A ZONE OF
HIGHEST POPS CONTINUING JUST EAST OF BLUE RIDGE WITH LOWER POPS
FARTHER EAST BORDERING WAKEFIELD FCST AREA...AT LEAST UNTIL LATE
AFTERNOON BEFORE THIS ZONE FINALLY SHIFT EAST AND NORTH OUT OF THE
FCST AREA BY EARLY EVENING.
PREV DISCUSSION AS OF 1025 AM EST SUNDAY...
UPDATED TO CANCEL FREEZING RAIN ADV FOR MTNS OF NW NC AND UP THE
BLUE RIDGE TO FLOYD WHERE HIGHER ELEVATIONS ARE WELL ABOVE
FREEZING. STILL POCKETS OF SUB FREEZING TEMPS IN PARTS OF NEW
RIVER VALLEY WITH SOME GROUND TEMPS LIKELY TO STILL BE BELOW
FREEZING...AND THEN NORTHWARD INTO ROANOAKE VALLEY AND MUCH OF
FOOTHILLS AND PIEDMONT STILL HAVE POCKETS OF SUB FREEZING TEMPS.
THUS WILL KEEP THE ADVISORY GOING UNTIL NOON IN THOSE LOCATIONS.
MOST OF PRECIP HAS MOVED EAST OF BLUE RIDGE...BUT DRIZZLE STILL
POSSIBLE AND ONGOING SLICK SPOTS UNTIL ALL TEMPS HAVE RISEN ABOVE
FREEZING.
PREVIOUS DISCUSSION AS OF 830 AM EST SUNDAY...
NUMEROUS CALLS COMING INTO THE OFFICE THIS MORNING OF AUTO
ACCIDENTS CAUSED BY SLICK ROADS EAST OF THE BLUE RIDGE. GROUND
TEMPERATURES IN MANY AREAS WERE SIGNIFICANTLY CHILLED DURING THE
POLAR SURGE A COUPLE DAYS AGO...AND WITH AIR TEMPERATURES ACROSS
THE PIEDMONT HOVERING AROUND FREEZING...GIVE OR TAKE A DEGREE...
EXPECT ICING TO CONTINUE FOR THE NEXT FEW HOURS. EVEN AFTER AIR
TEMPERATURES WARM LATER THIS MORNING...EXPECT ICING ON THE GROUND
TO BE SLOW TO MELT. MOTORISTS SHOULD EXERCISE EXTREME CAUTION WHEN
TRAVELING THIS MORNING AS THE ICING WILL BE VERY DIFFICULT TO SEE
UNTIL THEY ARE ALREADY DRIVING ON IT. TO MAKE MATTERS WORSE...
SURFACE OBSERVATIONS ACROSS THE MOUNTAINS INDICATE VISIBILITIES
FOGGING DOWN AS MOIST AIR CONTINUES TO WORK IN FROM THE
SOUTHWEST. EXPECT THESE CONDITIONS TO BE SLOW TO IMPROVE THROUGH
THE DAY.
WAVES OF LIGHT RAIN WILL PASS ACROSS THE REGION THROUGH THE DAY
AS MINOR DISTURBANCES EMBEDDED IN THE SOUTHWESTERLY FLOW ALOFT
MOVE ACROSS THE CENTRAL APPALACHIAN CHAIN. BELIEVE THAT THE LIGHT
RAIN WILL LIMIT HEATING ACROSS THE EAST AND HAVE THEREFORE HELD
HIGHS A LITTLE BELOW GUIDANCE...NAMELY THE UPPER 30S AND THE LOW
40S. RAINFALL WILL NOT BE AS WIDESPREAD ACROSS THE MOUNTAINS...AND
EXPECT TO SEE MID AND UPPER 40S THIS AFTERNOON.
ALL OF THIS WARM AIR IS FLOWING IN AHEAD OF OUR NEXT STRONG COLD
FRONT...EXPECTED TO ENTER THE REGION SHORTLY AFTER MIDNIGHT. THE
FRONT WILL SHIFT EAST VERY RAPIDLY...EXITING OUR AREA BEFORE
SUNRISE. WITH PRECIPITABLE WATER VALUES RISING TO AROUND AN INCH
BY MIDNIGHT...BELIEVE ALL LOCATIONS WILL SEE A BRIEF SHOT RAIN AS
THE FRONT PASSES. RAIN WILL CHANGE VERY RAPIDLY TO SNOW AS
TEMPERATURES DROP BEHIND THE FRONT...WITH SNOW ACCUMULATING
ACROSS THE WESTERN RIDGES THROUGH THE NIGHT.
THE GREATEST IMPACTS OF THE COLD FRONT WILL BE FELT ALONG THE
WESTERN MOST COUNTIES FROM GREENBRIER TO WATAUGA. HIGHEST
SNOWFALL ACCUMULATIONS WILL OCCUR IN WESTERN GREENBRIER AND
NORTHERN SUMMERS COUNTIES...WHERE LOCALLY 6 TO 9 INCHES ARE POSSIBLE
THROUGH MONDAY MORNING. LESSER AMOUNTS OF 2 TO LOCALLY 5 INCHES
ARE POSSIBLE ACROSS THE WEST FACING SLOPES IN THE MOUNTAIN EMPIRE
AND NORTHERN NORTH CAROLINA. GUSTY WINDS BEHIND THE FRONT WILL
RESULT IN BLOWING SNOW AND POSSIBLY WHITE OUT CONDITIONS THAT MAY
PERSIST INTO THE MONDAY MORNING COMMUTE. IN ADDITION...THE COLD
AIR WILL LIKELY RESULT IN FLASH FREEZING OF WET SURFACES FROM
RAINFALL EARLIER IN THE EVENING...MAKING FOR SLICK ROADWAYS.
AS A RESULT...HAVE ISSUED A WINTER STORM WARNING FOR OUR WESTERN
MOST COUNTIES...AND A WIND ADVISORY FOR ALL OF OUR MOUNTAIN
COUNTIES...BEGINNING AT MIDNIGHT TONIGHT.
&&
.SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/...
AS OF 545 AM EST SATURDAY...
BY THE BEGINNING OF THIS PERIOD WE WILL BE FIRMLY ENTRENCHED IN
THE THRAWLS OF AN INTENSE ARCTIC AIR MASS THAT PROMISES TO BRING
SOME OF THE COLDEST TEMPERATURES IN A COUPLE OF DECADES ALONG WITH
DANGEROUSLY COLD WIND CHILLS. ALTHOUGH THE BULK OF SYNOPTICALLY
DRIVEN PCPN WILL BE ENDING DURING THIS TIME FRAME...UPSLOPE SNOW
SHOWERS WILL MOST CERTAINLY CONTINUE GIVEN STRENGTH OF CAA. IN
FACT...FEELS MODELS ARE WAY TO QUICK IN ENDING SHSN...AND HAVE
EXTENDED WELL BEYOND THE MODEL INDICATIONS OF 18Z MON...ALL THE
WAY TO EARLY TUESDAY MORNING. GRANTED...THE MOST SIGNIFICANT
SNOWFALL WILL END BY 18Z MON...BUT EXPECT SHSN TO CONTINUE IN
EARNEST ALONG WEST FACING SLOPES WITH ADDITIONAL ACCUMULATIONS OF
ANOTHER INCH OR TWO POSSIBLE IN THIS TIME FRAME. THUS...THE SNOW
PORTION OF THE WINTER STORM WARNING WILL REMAIN IN EFFECT UNTIL
00Z TUE.
WIND CHILL WILL PERHAPS BE THE MOST SIGNIFICANT ISSUE WITH THIS
EVENT...WITH DANGEROUSLY COLD -20 TO -40F WIND CHILLS IN PLACE
OVERNIGHT MONDAY INTO THE FIRST HALF OF THE DAY TUE. HAVE UPGRADED
THE WIND CHILL WATCH TO A WIND CHILL WARNING WITH THIS PACKAGE AND
ALSO INCLUDED A WIND CHILL ADVISORY FOR THE REMAINDER OF THE
CWA...GENERALLY EAST OF I-81 AND I-77...PRINCIPALLY THE PIEDMONT.
SUSTAINED WINDS SHOULD REMAIN MOSTLY IN THE 15 TO 30 MPH RANGE
LATE TONIGHT THROUGH EARLY TUE...BUT GUSTS OF 45 TO 50 MPH CAN BE
EXPECTED IN THE HIGHER ELEVATIONS OF THE ALLEGHANYS AND BLUE
RIDGE. THIS SPEEDS DO NOT MEET HIGH WIND WARNING CRITERIA...SO
HAVE SIMPLY GONE WITH A WIND ADVISORY AT THIS POINT.
A STRONG NON-DIURNAL TEMPERATURE TREND IS EXPECTED MON...WITH
TEMPERATURES CONTINUING TO PLUNGE UNTIL EARLY TUE. BY TUE
MORNING...THE WESTERN PARTS OF THE CWA WILL BE WELL BELOW
ZERO...WITH -20F POSSIBLE IN NW GREENBRIER EARLY TUE...GENERALLY 0
TO -10F ELSEWHERE THROUGH THE ALLEGHANYS TO THE SINGLE DIGITS
ACROSS THE PIEDMONT. HAVE FAVORED THE COLDER ECMWF MOS FOR MINS
THROUGH THE PERIOD WITH THE COLDER MEX MOS FOR MAXS THROUGH THE
PERIOD. THE ARCTIC HIGH WILL BE CENTERED RIGHT OVER THE CWA AT 12Z
WED...SO ONLY A SLOW MODERATION IN TEMPERATURES ARE EXPECTED WED
AS THE -30C AIR AT 850MB FINALLY LIFTS OUT OF THE CWA.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
AS OF 200 PM EST SATURDAY...
DURING THIS PORTION OF THE FORECAST...THE WEATHER PATTERN ACROSS OUR
REGION WILL TRANSITION TO ONE DOMINATED MORE BY THE SOUTHERN STREAM
OF THE JET STREAM RATHER THAN THE NORTHERN STREAM. WITHIN THIS
PATTERN WILL BE A SERIES OF FAST MOVING DISTURBANCES...EACH WITH THE
POTENTIAL TO BRING SOME LIGHT PRECIPITATION TO PARTS OR ALL OF THE
FORECAST AREA. SPECIFICALLY...WE ARE EXPECTING A SYSTEM THURSDAY
AFTERNOON AND THURSDAY NIGHT TO IMPACT MAINLY THE WESTERN PARTS OF
THE REGION. ONE FRIDAY INTO FRIDAY NIGHT MAY SKIRT THE FAR WESTERN
PART OF THE REGION. FINALLY...ONE LATE FRIDAY NIGHT THROUGH SATURDAY
HAS THE POTENTIAL OF BRINING RAIN TO ALL OF THE REGION.
EACH DAY...TEMPERATURES WILL TREND MILDER SO THAT BY SATURDAY HIGH
TEMPERATURES ARE FORECAST IN THE LOWER 50S ACROSS THE MOUNTAINS WITH
MID TO UPPER 50S ACROSS THE PIEDMONT. MOST OF THE PRECIPITATION
ASSOCIATED WITH THE DISTURBANCES WILL BE IN THE FORM OF RAIN. ENOUGH
COLD AIR WILL STILL BE AROUND THURSDAY NIGHT INTO FRIDAY FOR SOME
POCKETS OF FREEZING RAIN.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 730 AM EST SUNDAY...
RADAR INDICATES AREAS OF LIGHT RAIN AND FREEZING RAIN MAINLY EAST
OF THE BLUE RIDGE THIS MORNING AS WARMER GULF MOISTURE RIDES IN
OVERTOP COLDER AIR AT THE SURFACE. TEMPERATURES FOR DAN...ROA
AND LYH ARE HOVERING AT FREEZING...GIVE OR TAKE A DEGREE...AND
EXPECT LIGHT FREEZING RAIN TO PERSIST THROUGH ABOUT 10 AM FOR DAN
AND ROA...WHEN TEMPERATURES WILL WARM ABOVE FREEZING. WARMING WILL
BE SLOWER AT LYH...AND MAY TAKE UNTIL NOON FOR FREEZING RAIN TO
END. ACCUMULATIONS WILL BE LIGHT...NOT MUCH MORE THAN A GLAZING.
DRIER AND WARMER CONDITIONS ARE OBSERVED AT BLF AND BCB...WITH
TEMPERATURES ABOVE FREEZING. CLOUD COVER JUST MOVED IN AT
LWB...WHICH IS SITTING IN THE UPPER TEENS BUT IS OTHERWISE DRY.
LOW CLOUDS WILL PERSIST ACROSS THE REGION THROUGH THE DAY AS
MOIST AIR BUILDS IN AHEAD OF A STRONG COLD FRONT. CEILINGS WILL
SPEND THE DAY AROUND 1 KFT OR LOWER FOR MOST LOCATIONS. IN
ADDITION...VISIBILITIES EAST OF THE BLUE RIDGE MAY BRIEFLY DROP
INTO THE 1SM TO 2SM RANGE AS WAVES OF RAIN PASS OVERHEAD.
THE COLD FRONT WILL ENTER THE REGION AFTER MIDNIGHT MONDAY. WILL
SEE SCATTERED SHOWERS ALONG AND AHEAD OF THE FRONT QUICKLY
TRANSITION TO SNOW AFTER THE FRONT PASSES. VERY COLD AIR WILL
ARRIVE BEHIND THE FRONT...WHICH IS LIKELY TO CAUSE FLASH FREEZING
OF WET SURFACES FROM RAINFALL EARLIER IN THE EVENING. ONCE THE
SNOW SETS IN...EXPECT SEVERAL HOURS OF VISIBILITIES AROUND 1SM FOR
ROA WESTWARD...WHILE SNOW SHOWERS WILL NOT PERSIST AS LONG FOR DAN
AND LYH. EXPECT THE CHANGE OVER TO SNOW AROUND 06/08Z AT BLF AND
LWB...06/09Z FOR BCB AND ROA...AND 06/10Z FOR LYH AND DAN.
ACCUMULATIONS OF AROUND 4 INCHES ARE POSSIBLE FOR BLF...AN INCH OR
TWO AT LWB...AND LESS THAN AN INCH FOR ROA AND BCB. STRONG WINDS
FROM THE NORTHWEST WILL ACCOMPANY THE FRONT...WITH OCCASIONAL 35
TO 40 KT GUSTS EXPECTED ACROSS THE MOUNTAINS. STRONG CROSS-
BARRIER FLOW WILL ALSO RESULT IN MODERATE TURBULENCE.
WHILE WINDS WILL DIMINISH SOMEWHAT ON MONDAY AFTERNOON...A
SECONDARY SHOT OF ARCTIC AIR WILL ARRIVE MONDAY NIGHT...CAUSING
WIND SPEEDS TO INCREASE ONCE AGAIN. THIS ARCTIC AIR WILL CAUSE
TEMPERATURES TO FALL INTO THE POSITIVE SINGLE DIGITS EAST OF THE
BLUE RIDGE...AND FALL BELOW ZERO TO THE WEST. SNOW SHOWERS WILL
PERSIST ACROSS THE MOUNTAINS THROUGH TUESDAY MORNING...BEFORE
HIGH PRESSURE SETTLES IN...CAUSING WIND SPEEDS AND SNOW SHOWERS TO
DECREASE.
&&
.CLIMATE...
AS OF 220 PM EST THURSDAY...
FORECAST LOW TEMPERATURES MONDAY NIGHT...EARLY JAN 7...ARE
FORECAST TO BE AROUND ZERO OR A BIT BELOW ZERO ACROSS THE
MOUNTAINS AND IN THE SINGLE DIGITS TO NEAR 15 ACROSS THE PIEDMONT.
OF OUR CLIMATE SITES...ALL BUT DANVILLE IS FORECAST TO BREAK THE
RECORD. HIGH TEMPERATURES ON TUESDAY JANUARY 7 ARE FORECAST TO BE
IN THE TEENS ACROSS THE MOUNTAINS AND LOW TO MID 20S ACROSS THE
PIEDMONT. OUR CURRENT FORECAST PLACES THE RECORD MINIMUM HIGH
TEMPERATURE RECORDS IN JEOPARDY AT BOTH BLACKSBURG AND LEWISBURG
WHILE THE OTHER LOCATION WILL SEE TEMPERATURES WITHIN A FEW
DEGREES OF THE RECORDS.
JANUARY 7 RECORDS
LOWS MINIMUM HIGHS
BLACKSBURG VA... 1/1988 19/1988
BLUEFIELD WV.... 0/1970 11/1988
DANVILLE VA..... 10/1969 26/1988
ROANOKE VA...... 8/1970 17/1988
LEWISBURG WV.... 7/2004 11/1988
LYNCHBURG VA.... 10/1912 17/1988
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST TUESDAY FOR
VAZ007-009>020-022>024.
WIND CHILL WARNING FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
VAZ007-009>020-022>024.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 7 PM EST MONDAY
FOR VAZ007-009-015.
WIND CHILL ADVISORY FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
VAZ032>035-043>047-058-059.
NC...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST TUESDAY FOR
NCZ001-002-018.
WIND CHILL WARNING FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
NCZ001-002-018.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 7 PM EST MONDAY
FOR NCZ001-018.
WIND CHILL ADVISORY FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
NCZ003>006-019-020.
WV...WIND ADVISORY FROM MIDNIGHT TONIGHT TO 1 PM EST TUESDAY FOR
WVZ042>045.
WIND CHILL WARNING FROM 5 PM MONDAY TO 3 PM EST TUESDAY FOR
WVZ042>045.
WINTER STORM WARNING FROM MIDNIGHT TONIGHT TO 7 PM EST MONDAY
FOR WVZ042-043-045.
&&
$$
SYNOPSIS...NF/SK
NEAR TERM...NF/SK
SHORT TERM...RAB
LONG TERM...DS
AVIATION...NF/PM
CLIMATE...DS
YOU CAN SEE AN ILLUSTRATED VERSION OF THE FORECAST DISCUSSION AT
WWW.WEATHER.GOV/SEATTLE/GAFD/LATEST_WEBAFD.HTML
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
828 PM CST MON JAN 6 2014
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 825 PM CST MON JAN 6 2014
NO CHANGE TO HEADLINES THIS EVENING. PLAN IS TO POST A WIND CHILL
ADVISORY ONCE THE WARNING EXPIRES AT NOON TOMORROW. LOOKING AT OUR
CURRENT GRIDS...WOULD GUESS NOON TUE-NOON WED FOR TIMING OF THE
ADVISORY...BUT THAT COULD CHANGE DEPENDING ON ANY CHANGES TO THE
T/WIND/APPARENT-T FCST.
UPDATED WSW AND HWO JUST SENT
&&
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 231 PM CST MON JAN 6 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE STRETCHING FROM SOUTHERN SASKATCHEWAN TO THE GULF COAST OF
TEXAS EARLY THIS AFTERNOON. THE POLAR VORTEX IS SHIFTING EAST INTO
MICHIGAN THOUGH THE CORE OF THE EXTREMELY COLD AIR IS CURRENTLY
OVERHEAD. TEMPERATURES HAVE NOT WARMED TOO MUCH SO FAR TODAY...WITH
READINGS HOLDING STEADY FROM THE LOWER TEENS BELOW ZERO ALONG THE
LAKE MICHIGAN SHORELINE TO THE LOWER 20S BELOW ZERO OVER CENTRAL
WISCONSIN. WIND CHILLS REMAIN IN THE 35 TO 45 DEGREES BELOW ZERO
RANGE. AREAS OF THIN CLOUD COVER CONTINUE TO STREAM SOUTHEAST ON
THE BACKSIDE OF THE POLAR VORTEX...WITH A FEW FLURRIES BEING
REPORTED ON AREA OBSERVATION SITES. AS THE ARCTIC AIR
MODIFIES...TEMPS AND WIND CHILLS REMAIN THE MAIN FORECAST
CONCERNS...FOLLOWED BY CLOUDS/FLURRY CHANCES.
TONIGHT...ARCTIC HIGH PRESSURE WILL SLIDE TO THE GULF COAST...BUT
THE SURFACE RIDGE AXIS WILL HANG BACK ACROSS THE NORTHERN
MISSISSIPPI TO CENTRAL CANADA. THOUGH TEMPERATURES WILL BE
MODIFYING ALOFT...BRISK WEST WINDS WILL CONTINUE TO FUNNEL IN THE
EXTREME COLD FROM THE NORTHERN PLAINS. DO NOT HAVE A GOOD HANDLE ON
CLOUD COVER TONIGHT...BUT WITH THIN CLOUDS DROPPING SOUTH OVER
SOUTHERN CANADA AND MINNESOTA...FIGURE THE REGION WILL HAVE PARTLY
CLOUDY CONDITIONS THROUGH THE EVENING BEFORE A SLIGHT BACKING OF THE
WINDS PUSHES IN DRIER AIR IN AFTER MIDNIGHT. WITH THE SUSTAINED
WINDS AND A MODIFYING AIRMASS...TEMPS WILL BE A DEGREE OR TWO WARMER
OVER WESTERN SECTIONS OF THE FORECAST AREA...THOUGH WILL LIKELY BE A
FEW DEGREES COLDER OVER EASTERN SECTIONS. BUT WITH WINDS REMAINING
IN THE 10-15KT RANGE...WIND CHILLS WILL REMAIN IN THE 40 TO 50
DEGREE BELOW ZERO RANGE. THUS NO CHANGE TO HEADLINES.
TUESDAY...THE SURFACE RIDGE AXIS WILL SHIFT SLIGHTLY INTO WESTERN
WISCONSIN IN THE AFTERNOON WITH ONLY MID AND HIGH CLOUDS MOVING
OVERHEAD. THE WEST WINDS WILL NOT BE AS STRONG OR GUSTY AS
TODAY...AND COMBINED WITH FURTHER MODIFYING OF THE ARCTIC
AIRMASS...SHOULD SEE TEMPS ABOUT 10 DEGREES WARMER THAN TODAY
ACCORDING TO THE LEADING GUIDANCE. THE EXTREMELY COLD WIND CHILLS
ARE EXPECTED TO RISE TO BETWEEN 20 TO 30 DEGREES BELOW ZERO BY EARLY
AFTERNOON.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 231 PM CST MON JAN 6 2014
GRADUALLY IMPROVING TEMPERATURES THIS WEEK WILL BE THE PRIMARY
ISSUE FOLLOWED WITH SOME RESOLUTION WITH A FEW PRECIP CHANCES IN
THE NEAR ZONAL FLOW LATE THIS WEEK AND THROUGH THIS WEEKEND.
FOR STARTERS...ANTICIPATE THE ARCTIC AIR MASS WILL TAKE ITS TIME
TO DEPART THIS WEEK EVEN THOUGH H850 TEMPERATURES INCREASE. VERY
COLD DRY AIR MASS WILL BE RECYCLED BACK NORTH WITH THE RETURN FLOW
THROUGH THURSDAY. ANTICIPATED CLEAR SKIES AND LIGHT WINDS UNDER A
COLD HIGH PRESSURE SYSTEM WILL PROVIDE LARGE DIURNAL CHANGES WITH
SUB ZERO LOW TEMPERATURES CONTINUING INTO THURSDAY MORNING OVER
MOST LOCATIONS.
RETURN SOUTH TO SOUTHWEST FLOW BEGINS LATER THURSDAY SO TEMPS
WILL START TO ASCEND QUICKER WITH TEMPERATURES POSSIBLY REACHING
THE FREEZING MARK THIS WEEKEND OVER PARTS OF THE AREA. CLOUDS MAY
BE ON THE INCREASE OVER SOUTHERN WISCONSIN THROUGH THURSDAY WITH
THE PASSAGE OF A SOUTHERN STREAM SYSTEM TO THE SOUTH...BUT EXPECT THE
AREA TO REMAIN DRY WITH THE SURFACE HIGH STILL SETTLED OVER THE
AREA.
MODEL TIMING OF VARIOUS SHORT WAVES IN THE NEAR ZONAL FLOW POINTING
TO A FRIDAY INTO FRIDAY NIGHT TIME FRAME. A WEAK RIDGE SETTLES
OVER SATURDAY INTO SUNDAY BEFORE POSSIBLY ANOTHER WEAK SYSTEM
PASSES OVER LATER SUNDAY. AGAIN MODEL TIME IN QUESTION DUE TO
TIMING OF THESE SHORT WAVES IN THE ZONAL FLOW AND LIKELY WILL NEED
FURTHER ADJUSTMENTS.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 427 PM CST MON JAN 6 2014
VFR CONDITIONS EXPECTED AS BITTERLY COLD ARCTIC AIR DOMINATES THE
AREA. LLWS WL DEVELOP TNGT AS THE AIR ALOFT STARTS TO WARM...AND
INVERSION STRENGTHENS/LOWERS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
UPDATE.........SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
540 PM CST MON JAN 6 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 243 PM CST MON JAN 6 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA AND AN
ANOMALOUSLY DEEP TROUGH ENCOMPASSING MUCH OF THE EASTERN U.S..
WITHIN THIS DEEP TROUGH...THE POLAR VORTEX STRETCHED FROM NORTHERN
ONTARIO INTO LOWER MI. THE COLDEST AIR ASSOCIATED WITH THE VORTEX
HAS BEEN ON ITS BACK SIDE...NOTED BY 925MB TEMPS AT 12Z OF -34C AT
MPX AND -35C AT INL...OR 3-3.5 STANDARD DEVIATIONS BELOW NORMAL.
THIS ARCTIC AIR HAS MODIFIED SOMEWHAT THROUGH DAYTIME HEATING...BUT
925MB TEMPS PER RAP ANALYSIS ARE STILL NEAR -30C. SURFACE
TEMPERATURES HAVE MANAGED TO CLIMB INTO THE TEENS BELOW ZERO.
HOWEVER...A PERSISTENT 10 TO 20 MPH WIND WITH GUSTS TO 30 MPH HAVE
KEPT WIND CHILLS DOWN TO 35 TO 45 BELOW ZERO. THESE WINDS ARE A
RESULT OF A TIGHT PRESSURE GRADIENT BETWEEN A SURFACE RIDGE OVER
THE DAKOTAS AND A DEEP LOW OVER CENTRAL QUEBEC.
THE POLAR VORTEX IS PROGGED TO GRADUALLY LOSE ITS GRIP ACROSS THE
FORECAST AREA AND GREAT LAKES REGION...LIFTING INTO NORTHERN QUEBEC
BY 00Z WEDNESDAY. THIS WILL ALLOW WARMER AIR TO ENTER THE
REGION. ONE CAVEAT TO THE WARMER AIR IS A SHORTWAVE OVER THE
NORTHWEST TERRITORIES WHICH MODELS SHOW DROPPING DOWN THE BACK SIDE
OF THE VORTEX...COMING INTO NORTHERN WI AT 00Z WEDNESDAY. THIS
SHORTWAVE WILL SLOW SOME OF THE WARM UP.
REGARDING TEMPERATURES...925MB READINGS ARE PROGGED TO CLIMB THROUGH
THE NEXT 24 HOURS...REACHING -24 TO -28C BY 12Z TUE AND TO -18 TO -
22C BY 00Z WED. DESPITE THE WARMING ABOVE THE SURFACE...TEMPERATURES
SHOULD STILL COOL DOWN CLOSE TO READINGS SEEN LAST NIGHT BECAUSE OF
WINDS WHICH ARE GOING TO BE LIGHTER. HOWEVER...A BREEZE WILL PERSIST
SINCE THE SURFACE RIDGE IS STILL OFF TO OUR WEST...WHICH MEANS WIND
CHILL VALUES ARE LIKELY TO STAY BETWEEN 35 AND 55 BELOW ZERO. WINDS
DO MANAGE TO BACK MORE WEST TO POSSIBLY EVEN SOUTHWEST ON TUESDAY...
AHEAD OF A COLD FRONT DROPPING THROUGH MN THAT IS ACCOMPANYING THE
NORTHWEST TERRITORIES SHORTWAVE. THIS BACKING OF WINDS PLUS WARMER
925MB VALUES AND SOME SUN SHOULD HELP BOOST HIGHS TOWARDS THE SINGLE
DIGITS ABOVE ZERO...AT LEAST SOUTHWEST OF I-94. NORTH OF I-94...WIND
CHILL ISSUES ARE GOING TO CONTINUE THROUGH THE AFTERNOON AND AN
ADVISORY WILL BE NEEDED AFTER THE WARNING EXPIRES.
SKY COVER REMAINS A TRICKY FORECAST IN THIS ARCTIC AIRMASS.
ANTICIPATING A PERIOD OF POSSIBLY CLEAR SKIES THIS EVENING ONCE ANY
DIURNAL STRATOCUMULUS DISSIPATES WITH LOSS OF DAYTIME HEATING.
HOWEVER...LOW STRATUS CURRENTLY IN SOUTHERN MANITOBA AND NORTHWEST
MN LOOKS TO MAKE A RUN AT LOCATIONS NORTH OF I-94 LATE THIS EVENING
INTO THE OVERNIGHT HOURS. MID/HIGH CLOUDS SHOULD THEN INCREASE
OVERNIGHT THROUGH TUESDAY...WITH EVEN SOME LOWER STRATUS ACROSS
SOUTHERN PORTIONS OF THE AREA...AS ISENTROPIC LIFT PICKS UP AHEAD
OF THE COLD FRONT AND SHORTWAVE. SOME FLURRIES COULD OCCUR FROM
THE CLOUDS AS WELL ACROSS THE SOUTHWESTERN HALF OF THE AREA ON
TUESDAY AS CLOUD HEIGHTS THERE FALL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 243 PM CST MON JAN 6 2014
MODELS REMAIN IN AGREEMENT SHOWING THE PATTERN GREATLY DEAMPLIFYING
ACROSS THE U.S....BECOMING ZONAL BY THURSDAY MORNING. THIS WILL
SHIFT THE TEMPERATURE FLOW FROM THE ARCTIC TO THE PACIFIC. WE DO
HAVE TO WAIT JUST A LITTLE BIT LONGER AS THAT SHORTWAVE DROPPING
INTO NORTHERN WISCONSIN BRINGS A BRIEF REINFORCING SHOT OF COLD AIR
TUESDAY NIGHT. THIS SHOT OF COLD AIR WILL BE NOTICED THE MOST IN
NORTHERN WI WHERE WIND CHILLS LOOK TO STAY DOWN BETWEEN 20 AND 35
BELOW ZERO. A SURFACE HIGH PRESSURE AREA IS PROGGED TO DRIFT
ACROSS THE FORECAST AREA LATE WEDNESDAY INTO WEDNESDAY NIGHT. THIS
HIGH SHOULD HELP TO CALM THE WINDS DOWN...WHICH DOES BRING A
CONCERN FOR LOW TEMPERATURES WEDNESDAY NIGHT...ESPECIALLY OVER
WISCONSIN. AIRMASS REMAINS QUITE DRY WITH PRECIPITABLE WATER BELOW
0.1 INCHES...SO TEMPERATURES COULD REALLY TANK IN THE TYPICALLY
COLD SPOTS. SOUTHERLY FLOW ON THE BACK SIDE OF THIS HIGH PRESSURE
AREA KICKS WARM ADVECTION INTO HIGH GEAR ON THURSDAY. 925MB TEMPS
CLIMB TO -6 TO -10C. ALTHOUGH THERE MAY BE QUITE A FEW CLOUDS
AROUND...THESE SOUTHERLY WINDS SHOULD HELP PROPEL TEMPERATURES
GENERALLY INTO THE MID TEENS TO AROUND 20...ABOUT 30 DEGREES
WARMER THAN TODAY. NOTE...THERE COULD BE SOME WIND CHILL ISSUES
THURSDAY MORNING AS THE SOUTH WINDS INCREASE. THERE WERE SOME
HINTS OF THE 06.15Z SREF OF SOME POSSIBLE PRECIPITATION WITH THIS
WARM ADVECTION...BUT KEPT THESE OUT WITH NO OTHER DETERMINISTIC
MODEL GUIDANCE SHOWING IT.
HIGHLIGHTS FOR FRIDAY INTO MONDAY...
1. GOOD MODEL AGREEMENT EXISTS THAT A FAIRLY SIGNIFICANT SHORTWAVE
TROUGH WILL MOVE FROM THE PACIFIC NORTHWEST ON THU...TO THE NORTHERN
PLAINS ON FRI AND GREAT LAKES ON SAT. A PLUME OF HIGHER PRECIPITABLE
WATER ON THE ORDER OF A 0.5-0.7 INCHES COMES INTO THE REGION AHEAD
OF THE TROUGH ON FRIDAY. COMBINING THIS MOISTURE WITH THE DPVA AND
ISENTROPIC LOOKS TO YIELD SOME PRECIPITATION. HAVE RAISED POPS ABOUT
5-10 PERCENT...BUT IF THE TRENDS IN THE 06.12Z GFS/ECMWF CONTINUE
THESE CHANCES NEED TO BE RAISED FURTHER. NOTE THAT THE 06.12Z
CANADIAN HOLDS PRECIPITATION OFF TIL FRIDAY NIGHT...WHICH IS PARTLY
THE CAUSE TOO OF THE SMALLER CHANCE INCREASE. THE TYPE IS
SOMEWHAT OF AN ISSUE TOO...DUE TO A LOSS OF ICE IN THE CLOUD AND
WARM LAYER INITIALLY FRIDAY MORNING. IT APPEARS ONCE THINGS
SATURATE...EVAPORATIVE COOLING KNOCKS DOWN ANY WARM LAYER AND CLOUDS
ARE SEEDED WITH ICE. THIS SHOULD OCCUR BY EARLY AFTERNOON.
PRECIPITATION SHOULD END WEST TO EAST FRIDAY NIGHT AS THE SYSTEM
PULLS AWAY. ANY LOSS OF ICE IN THE CLOUDS FRIDAY NIGHT SHOULD OCCUR
AFTER THE PRECIP EXITS.
2. A SERIES OF TWO SHORTWAVE TROUGHS TRACKING ACROSS THE REGION
SUNDAY THROUGH MONDAY. PREVIOUSLY ECMWF RUNS WERE SUGGESTING THAT
THESE TROUGHS WERE GOING TO HOLD BACK OVER THE WESTERN U.S.. NOW
THEY ARE MORE PROGRESSIVE...LIKE THE 05.12Z GFS RUN. THIS MEANS A
BIT LESS CONFIDENCE IN PRECIPITATION AS MOISTURE RETURN BEHIND THE
SATURDAY SYSTEM IS SLOWER TO COME BACK. THEREFORE...CHANCES WERE
LOWERED. IT IS ENTIRELY POSSIBLE SUNDAY THROUGH MONDAY ENDS UP
MAINLY DRY.
3. ABOVE NORMAL TEMPERATURES. BOTH THE FRIDAY AND SUNDAY SHORTWAVE
TROUGHS HELP TO PULL EVEN WARMER AIR INTO THE REGION. 925MB TEMPS
GET UP CLOSE TO 0C ON FRIDAY...COOL SLIGHTLY TO -2 TO -6C ON
SATURDAY...BACK UP TO 0-3C ON SUNDAY AND DOWN TO -2 TO -6C ON
MONDAY. EACH OF THESE DAYS WE SHOULD BE ABLE TO GET HIGHS INTO THE
UPPER 20S TO LOW 30S...AND SUNDAY THERE ARE SIGNS WE COULD TRY TO
PUSH 40. RAISED HIGHS A LITTLE ON SUNDAY AS A RESULT.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z TUESDAY EVENING)
ISSUED AT 540 PM CST MON JAN 6 2014
NORTHWEST FLOW AROUND THE BACK SIDE OF THE DEEP POLAR TROUGH
CONTINUES TO SEND WEAK RIPPLES THROUGH THE AREA. WITH THE COLD AIR
IN PLACE...EACH RIPPLE GENERATES PATCHES OF CLOUD...SOME OF WHICH
OPT TO DROP FLURRIES. FOR THE MOST PART...VFR CONDITIONS WILL
PREVAIL THROUGH THE NIGHT WITH MUCH OF THE CLOUD COVER AT MID
LEVELS. HOWEVER PATCHES OF MVFR CLOUD WILL BE SEEN AT TIMES...
ALONG WITH PATCHES OF FLURRIES. BEST CHANCE TO SEE THIS WILL BE
AT KLSE...BUT SHOULD NOT LAST LONG. DURING THE DAY TUESDAY...WARM
ADVECTION WILL HELP THICKEN AND LOWER THE CLOUD COVER...ESPECIALLY
OVER MN/IA. CLOUD HEIGHTS LOOK TO REMAIN ABOVE 5KFT.
&&
.CLIMATE...
ISSUED AT 243 PM CST MON JAN 6 2014
SO FAR NO RECORDS HAVE BEEN SET AT EITHER LA CROSSE OR ROCHESTER.
HOWEVER...A FEW RECORD LOW TEMPERATURES WERE SET AT COOPERATIVE
OBSERVER SITES...
BYRON MN...........-24. OLD RECORD -10 IN 2010
FRIENDSHIP WI......-22. OLD RECORD -18 IN 1942
OWEN WI............-26. OLD RECORD -26 IN 1979
WINONA DAM 5A MN...-21 OLD RECORD -12 IN 1942
THE COLDEST THE WIND CHILL GOT TO IN LA CROSSE WAS -48 AND AT
ROCHESTER WAS -53. NEITHER MADE IT INTO THE TOP 10...BUT WERE ONLY
ABOUT 5 DEGREES WARMER THAN THE FEBRUARY 2-3 1996 ARCTIC OUTBREAK.
SEE OUR TOP NEWS STORY ON OUR WEBSITE WWW.WEATHER.GOV/ARX FOR MORE
CLIMATE INFORMATION ON THE COLD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR MNZ079-086>088-
094>096.
IA...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW
CLIMATE...AJ
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 204 PM CST SUN JAN 5 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A STRENGTHENING
AREA OF LOW PRESSURE MOVING NORTHEAST OVER THE OHIO VALLEY. A WIDE
SWATH OF HEAVY SNOW IS IMPACTING ST LOUIS TO THE THUMB OF MICHIGAN JUST
NORTH OF THE SURFACE LOW TRACK...AND IS NOT SHOWING ANY SIGNS OF
LIFTING INTO EAST-CENTRAL WISCONSIN. ALTOSTRATUS ON THE NORTHERN
PERIPHERY OF THIS SYSTEM IS MOVING ACROSS MUCH OF CENTRAL AND NORTHEAST
WISCONSIN AND IS PREVENTING ANY SUNSHINE TO OFFSET THE COLD
TEMPERATURES. READINGS THIS AFTERNOON REMAIN BELOW ZERO WEST OF A
WAUTOMA TO IRON MOUNTAIN LINE...WHERE WIND CHILLS ARE NEAR OR BELOW
WIND CHILL ADVISORY CRITERIA (-20F). FARTHER WEST...A LOBE OF THE
POLAR VORTEX IS DROPPING SOUTHEAST OVER THE DAKOTAS WHERE TEMPS ARE
IN THE TEENS BELOW ZERO WITH WINDS GUSTING OVER 40 KTS. ALSO SEEING
LOWER VSBYS WITHIN SOME CLOUD COVER IN THIS REGION...BUT THINK MUCH
OF THESE OBS CAN BE ATTRIBUTED TO BLOWING SNOW. AS THE POLAR VORTEX
AND ASSOCIATED ARCTIC AIR MOVES ACROSS THE REGION...LIGHT SNOW
CHANCES AND WIND CHILL HEADLINES ARE THE MAIN FORECAST CONCERNS.
TONIGHT...THE LOW PRESSURE SYSTEM WILL MOVE FROM THE OHIO VALLEY TO THE
EASTERN GREAT LAKES THIS EVENING. CYCLONIC FLOW AROUND THE LOW WILL
DELAY THE BITTERLY COLD ARCTIC AIR FROM REACHING NORTHEAST WISCONSIN
UNTIL LATE IN THE EVENING OR EARLY OVERNIGHT. OTHERWISE A LOBE OF
THE POLAR VORTEX WILL SWING EAST FROM THE NORTHERN MISSISSIPPI
VALLEY TO NORTHEAST WISCONSIN. AS THIS OCCURS...SHOULD SEE AN AREA
OF LOW AND MID CLOUDS MOVE EAST OVER THE FORECAST AREA. SINCE THE
LOWER VSBYS OVER THE DAKOTAS HAS THE LOOK OF BLOWING SNOW...WILL
REMOVE THE FLURRY MENTION AFTER MIDNIGHT. HOWEVER...MODELS TRY TO
RETURN SOME MOISTURE FROM THE SOUTH AHEAD OF THE SHORTWAVE LOBE AND
PRODUCE LIGHT SNOW OR FLURRIES ALONG THE LAKE MICHIGAN SHORELINE
LATE TONIGHT. THIS POSSIBILITY STILL LOOKS REASONABLE AND WILL
LEAVE IN THE FORECAST. OTHERWISE...THE MAIN STORY WILL BE THE
ADVECTION OF THE COLDEST AIR THE REGION HAS OBSERVED IN YEARS.
850MB TEMPS WILL FALL INTO THE -25C TO -35C RANGE MY 12Z MON WHICH
WILL BRING IN SURFACE TEMPS FROM 30 BELOW OVER NORTH-CENTRAL
WISCONSIN TO ABOUT 15 BELOW AT THE LAKE MICHIGAN SHORELINE.
COMBINED WITH WINDS GUSTING TO 25 TO 30 MPH...PROJECTED WIND CHILLS
WILL FALL INTO THE 40 TO 55 DEGREES BELOW ZERO RANGE. EASTERN
SECTIONS MAY NOT REACH WIND CHILL WARNING CRITERIA UNTIL AFTER
MIDNIGHT...BUT THEY WILL BE FALLING RAPIDLY THROUGH THE EVENING...SO
WILL LEAVE THE WARNING START TIMES ALONE TO INCLUDE THE ADVISORY
RAMP UP TIME.
MONDAY...THE POLAR VORTEX WILL BE EXITING NORTHEAST WISCONSIN EARLY
IN THE MORNING AND WILL LEAVE A SMALL CHANCE OVER DOOR COUNTY TO
ACCOUNT FOR THAT. SHOULD SEE A PERIOD OF DECREASING CLOUDS UNTIL
MID AND HIGH CLOUDS SLIDE IN FROM THE NORTH DURING THE AFTERNOON.
NOT SURE HOW MUCH OF THESE CLOUDS WILL HOLD TOGETHER...SO WILL KEEP
SKIES IN THE PARTLY CLOUDY RANGE. ARCTIC HIGH PRESSURE WILL SLIDE
SOUTHEAST TOWARDS THE CENTRAL PLAINS WHICH SHOULD KEEP A TIGHT
PRESSURE GRADIENT IN PLACE. COMBINED WITH TEMPERATURES IN THE
NEGATIVE TEENS BELOW ZERO FOR HIGHS...WIND CHILLS WILL REMAIN IN THE
35 TO 45 DEGREES BELOW ZERO RANGE. WIND CHILL WARNINGS WILL
CONTINUE AS A RESULT.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 204 PM CST SUN JAN 5 2014
THE BITTER COLD REGIME OF ARCTIC AIR WILL STUBBORNLY DIMINISH
THIS WEEK AS THE UPPER FLOW TURNS MORE ZONAL WITH THE INTRODUCTION
OF WESTERLY PACIFIC FLOW AND MILDER CONDITIONS BY NEXT WEEKEND.
EVEN THOUGH THE CENTER OF THE POLAR VORTEX IS LIFTING NORTHEAST OF
THE AREA MONDAY NIGHT INTO EARLY TUESDAY...BITTER COLD AIR MASS
LEFT IN ITS WAKE COMBINED WITH WEST WINDS 10 TO 20 MPH WILL
CONTINUE TO PRODUCE WARNING WIND CHILL NUMBERS THROUGH A GOOD
PORTION OF TUESDAY BEFORE SUBSIDING TO ADVISORY CRITERIA IN THE
AFTERNOON.
HIGH PRESSURE RIDGE BEGINS TO SETTLES OVER THE AREA LATER TUESDAY
AFTERNOON INTO TUESDAY NIGHT. EVEN THOUGH 850 TEMPS BEGIN TO
MODIFY...EXPECTED CLEAR SKIES AND LIGHT WINDS WILL ALLOW TEMPS TO
PLUMMET WELL BELOW ZERO AGAIN. DEPENDING ON WINDS...PARTS OF THE
THE AREA MAY STILL WARRANT WIND CHILL ADVISORY HEADLINES. THE COLD
HIGH PRESSURE REMAINS SETTLED OVER THE REGION WEDNESDAY NIGHT AND
THURSDAY FOR CONTINUED BELOW NORMAL SUB ZERO TEMPERATURES. A WEAK
SYSTEM IS PROGGED TO PASS SOUTH OF THE AREA WEDNESDAY NIGHT AND
THURSDAY...HAS TRENDED SOUTH LEAVING THE AREA MORE IN THE COLD
AIR MASS.
WAA PATTERN BEGINS IN EARNEST LATER THURSDAY INTO FRIDAY WITH
TEMPERATURES APPROACHING THE FREEZING MARK FOR THE WEEKEND. DUE
TO THE ZONAL FLOW...MODELS ARE PRODUCING DIFFERENT SOLUTIONS WITH
TIMING OF WEAK SHORT WAVES PASSING OVER OR NEAR THE GREAT LAKES
REGION FRIDAY INTO SUNDAY. USUALLY THE PACIFIC SYSTEMS ARE ON THE
DRY SIDE BUT WITH H850 TEMPERATURES ABOVE ZERO THIS WEEKEND...PCPN
TYPE ISSUES WILL INCREASE.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1128 AM CST SUN JAN 5 2014
A WINTER CYCLONE WILL PASS TO OUR SOUTHEAST THROUGH THE AFTERNOON
HOURS. BACK EDGE OF THE PRECIP LIKELY TO REMAIN SOUTH OF THE
FORECAST AREA...THOUGH A BKN TO OVC MID-LEVEL CLOUD DECK WILL BE
OVERHEAD THROUGH THE REST OF THE AFTERNOON. THEN A SHARP UPPER
LEVEL DISTURBANCE WILL SHIFT EAST ACROSS THE FORECAST AREA TONIGHT.
SHOULD SEE AN ADDITIONAL AREA OF MID-CLOUDS WITH THIS
SYSTEM...THOUGH MUCH OF THE AREA LOOKS TO REMAIN DRY. THE EXCEPTION
COULD BE ALONG THE LAKE MICHIGAN SHORELINE...WHERE MOISTURE FROM THE
CYCLONE TO THE SOUTH MAY WORK NORTHWARD AHEAD OF THE DISTURBANCE TO
PRODUCE FLURRIES OR VERY LIGHT SNOW. OTHERWISE...THE MAIN STORY
WILL BE THE INCOMING VERY COLD TEMPERATURES TONIGHT AND MONDAY
ALBEIT WITH VFR CONDITIONS AND GUSTY NORTHWEST WINDS.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING FROM 6 PM THIS EVENING TO NOON CST TUESDAY
FOR WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074.
WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ005-
010>012-018-019-030-035-036.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1012 PM CST SAT JAN 4 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 841 PM CST SAT JAN 4 2014
COLD AIR STARTING TO BECOME ESTABLISHED ACROSS THE AREA...SLOWLY.
EVEN TEMPS BACK IN THE DAKOTAS NOT EXTREMELY COLD YET...SO IT WILL
TAKE A WHILE FOR THE BITTERLY COLD AIR TO ARRIVE. WINDS HAVE
ACTUALLY DIED OFF IN N-C WI. BUT THEY SHOULD PICK UP AGAIN LATER
TNGT AS THE GRADIENT TIGHTENS. START TIME OF THE WIND CHILL
ADVISORY IS PROBABLY STILL A LITTLE TOO EARLY...BUT IT SHOULD BE
IN THE BALLPARK ACRS THE W. THE E MAY NOT HIT ADVISORY CRITERIA
BEFORE TOMORROW NIGHT...BUT THE COMBINATION OF WINDS/TEMPS SHOULD
RESULT IN DOUBLE DIGIT BELOW ZERO WIND CHILLS OVER THE E
TOMORROW...SO WL LEAVE IT TO THE MIDNIGHT SHIFT TO MAKE ANY
FURTHER ADJUSTMENTS TO THE ADVISORY IF NEEDED.
00Z NAM WRAPS PCPN BACK INTO FAR ERN WI TOMORROW EVENING. THAT/S
QUITE AMAZING CONSIDERING SFC TEMPS PROGGED TO BE DOUBLE-DIGIT BLO
ZERO AT THE TIME. LOOKS LIKE ANY SNOW WOULD OCCUR VERY LATE SUN OR
SUN NGT...SO DON/T FEEL THE NEED TO RUSH INTO ANY ADJUSTMENTS THAT
FAR OUT INTO THE FORECAST BEFORE THE REST OF THE 00Z PRODUCT
SUITE ARRIVES.
NO ADDITIONAL HEADLINE CHANGES ANTICIPATED THIS EVENING.
UPDATE
ISSUED AT 656 PM CST SAT JAN 4 2014
COLD AIR HAS BEEN SLOW TO ADVANCE EASTWARD. ADJUSTED THE HOURLY
GRIDS FOR TONIGHT AND TOMORROW AND RE-DID THE WIND CHILLS. LOOKS
LIKE WE WON/T GET CLOSE TO MEETING WIND CHILL ADVISORY CRITERIA IN
THE WEST UNTIL AT LEAST MIDNIGHT...AND IN THE EAST UNTIL 12Z
SUNDAY. AND WE MIGHT NOT REACH ADVISORY CRITERIA AT ALL TOMORROW
IN THE E...AS THE EWD PROGRESS OF THE COLD AIR WL BE FURTHER
DELAYED BY THE WAVE DEVELOPING ON THE ARCTIC FRONT. BUT WE/VE HAD
THE ADVISORY RUNNING FOR SUNDAY FOR QUITE SOME TIME...AND WIND
CHILLS SHOULD AT LEAST BE CLOSE TO ADVISORY CRITERIA...SO DON/T
WANT TO BAIL ON THE ADVISORY UNLESS IT/S A CERTAINTY IT WON/T
VERIFY.
THE SECOND FORECAST PROBLEM WILL BE THE TRACK OF THE WV NEWD ALONG
THE ARCTIC FRONT. ALMOST ALL THE HI RES MODELS TRACK THE WAVE FAR
ENOUGH W TO DRIVE PCPN BACK INTO FAR ERN WI LATE TOMORROW AFTN.
WON/T MAKE ANY CHANGES TO THAT ASPECT OF THE FCST YET...WANT TO
HAVE SOME TIME TO LOOK OVER AT LEAST SOME OF THE 00Z DATASET
BEFORE CONSIDERING ANY CHANGES.
UPDATED PRODUCT SUITE WL BE OUT ASAP.
&&
.SHORT TERM...TONIGHT AND SUNDAY
ISSUED AT 221 PM CST SAT JAN 4 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW AN ARCTIC COLD
FRONT MOVING EAST OVER NORTHEAST WISCONSIN EARLY THIS AFTERNOON.
EARLIER FREEZING DRIZZLE OVER CENTRAL AND NORTH-CENTRAL WISCONSIN
HAS MOSTLY DISSIPATED...AND ONLY A FEW FLURRIES ARE LEFT OVER THE
NORTH. MEANWHILE...CLEARING SKIES ARE WORKING THEIR WAY WEST FROM
MINNESOTA INTO CENTRAL WISCONSIN...BUT WILL TAKE A FEW MORE HOURS
FOR THE NORTH TO CLEAR. FARTHER EAST...SOUTHWEST WINDS IN THE UPPER
LEVELS ARE KEEPING A MID-LEVEL CLOUD DECK OVER THE LOW STRATUS ALONG
THE FRONT. THIS MID-LEVEL CLOUD DECK WILL HANG AROUND INTO THE
EVENING PERIOD. BEHIND THE FRONT...TEMPERATURES ARE GRADUALLY
FALLING BUT THE ARRIVAL OF THE COLDER AIR OVER THE DAKOTAS AND
SOUTHERN CANADA WITHIN SURFACE HIGH PRESSURE LOOKS DELAYED
SOMEWHAT. THE COLDEST AIR...HOWEVER...STILL RESIDES OVER NORTHERN
SASKATCHEWAN AND IS POISED TO ARRIVE LATE TOMORROW AFTERNOON.
TEMPERATURES AND WIND CHILL VALUES ARE THE MAIN FORECAST CONCERNS IN
THE SHORT TERM AS ARCTIC AIR RETURNS.
TONIGHT...THE ARCTIC FRONT WILL SHIFT EAST ACROSS CENTRAL AND
SOUTHERN GREAT LAKES WHERE A BAND OF SNOW WILL OCCUR. NORTHWEST OF THE
FRONT...ARCTIC HIGH PRESSURE WILL BE BUILDING SOUTHEAST INTO THE
REGION...AND PUSHING IN INCREASING AMOUNTS OF DRIER AIR IN THE LOW
LEVELS. THIS DRY AIR SHOULD HELP ERODE MUCH OF THE LOW CLOUD COVER
BY THE START OF THE EVENING. WITH WINDS A LITTLE TOO WESTERLY FOR
MUCH OF A LAKE EFFECT COMPONENT ACROSS THE SNOW BELTS...THE ONLY
CLOUD COVER WILL BE A BAND OF MID AND HIGH CLOUDS AS UPPER LEVEL
FLOW WILL REMAIN OUT OF THE SOUTHWEST WHICH WILL KEEP SKIES PARTLY
TO MOSTLY CLOUDY. IN REGARDS TO TEMPERATURES...WNW WINDS WILL BE
COLD ADVECTING THROUGH THE NIGHT WITH 850MB TEMPS DROPPING TO 23
BELOW OVER N-C WISCONSIN. TEMPS LAST NIGHT OVER NORTHERN MINNESOTA
WERE ONLY IN THE SINGLE DIGITS ABOVE AND BELOW ZERO...SO AM
CONCERNED ABOUT DROPPING TEMPS TOO MUCH. NOT CONFIDENT OF
DECOUPLING OCCURRING...SO WILL GO WITH LOWS AROUND IN THE NEG TEENS
BELOW ZERO OVER CENTRAL AND NORTH-CENTRAL WISCONSIN TO THE SINGLE
DIGITS ABOVE ZERO ALONG THE LAKE SHORE. AS MENTIONED ABOVE...THE
BITTERLY COLD AIR LOOKS TO BE DELAYED BY A FEW HOURS...AND MAY NOT REACH
WIND CHILL ADVISORY CRITERIA UNTIL 03Z OVER THE WESTERN FORECAST
AREA. WITH COORD FROM FORECAST OFFICES TO THE WEST...WILL DELAY THE
START TIME OF THE WESTERN ADVISORY UNTIL 03Z. THE EAST WILL START
AT 06Z AS PLANNED.
SUNDAY...SKIES WILL CONTINUE TO BE PARTLY TO MOSTLY CLOUDY WITH MID
HIGH CLOUDS OVERHEAD. SHOULD SEE THESE CLOUDS DEPART TO THE
SOUTHEAST BY LATE MORNING OR EARLY AFTERNOON. THEN A LOBE OF THE
POLAR VORTEX WILL SWING SOUTHEAST INTO THE NORTHERN MISSISSIPPI
VALLEY DURING THE AFTERNOON. A SECONDARY SURGE OF ARCTIC AIR WILL
ARRIVE WITH THE POLAR VORTEX...AND TEMPS MAY START THEIR FALL BY
MID-AFTERNOON. OFTEN WITH THE LEADING EDGE OF THESE BITTERLY COLD
AIRMASSES THERE ARE SCT INSTABILITY SNOW SHOWERS AND MODELS ARE
SHOWING HIGHER LOW LEVEL MOISTURE INCOMING TOMORROW AFTERNOON. NOT
SURE IF THIS WILL OCCUR IN THIS CASE SINCE THERE IS NO DEFINED
ARCTIC FRONT...BUT DID SHOW INCREASING CLOUDS LATE IN THE
AFTERNOON. ANOTHER THING TO KEEP TABS ON IS THE NORTHERN EXTENT OF
THE PRECIP TOMORROW AFTERNOON WITH WITH THE CYCLONE MOVING OVER THE
OHIO VALLEY. BOTH THE NAM AND GEM BRING LIGHT PRECIP INTO FAR E-C
WISCONSIN IN THE AFTERNOON...BUT THIS LOOKS TOO FAR INTO THE ARCTIC
AIRMASS. WILL LEAVE POPS OUT. WITH THE FALLING TEMPS IN THE
AFTERNOON...WIND CHILLS WILL BE APPROACHING WARNING CRITERIA OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN BY 00Z MON.
.LONG TERM...SUNDAY NIGHT THROUGH SATURDAY
ISSUED AT 221 PM CST SAT JAN 4 2014
PROGS STILL PASS THE CORE OF THE POLAR VORTEX OVER THE REGION
SUNDAY NIGHT INTO MONDAY BEFORE LIFTING EASTWARD INTO TUESDAY.
STRONG BAROCLINIC ZONE IN THE LEAD ARCTIC SURFACE FRONT POSITIONED
TO THE SOUTH AND EAST OF THE AREA LATE SUNDAY WILL BE THE FOCUS OF
ANOTHER SURFACE WAVE AND A REGION OF SNOW EARLY SUNDAY EVENING.
WHILE THE GFS KEEPS THIS AREA OF SNOW SOUTH OF THE AREA SUNDAY
EVENING...THE NAM LIFTS THE NORTHERN PERIPHERY OF THIS SNOW INTO
PARTS OF EAST CENTRAL WISCONSIN. FOR THIS SCENARIO TEMPS WOULD BE
A FEW DEGREES WARMER...BUT WINDS WOULD BE STRONGER DUE TO THE
LOCATION OF THE SURFACE WAVE AND PRESSURE GRADIENT. REGARDLESS OF
EITHER SCENARIO...LITTLE CHANGE TO GOING EXTREME COLD WIND CHILL
FORECASTS...SO NO CHANGES TO THE GOING WIND CHILL WARNING
HEADLINES STARTING SUNDAY EVENING.
FOR THE REST OF THE MODELS CONCERNING THIS LIGHT SNOW POTENTIAL
SUNDAY EVENING FOR THE LAKESHORE REGION...THE GEM AND ECMWF ALSO
PRODUCE SOME LIGHT SNOW ALONG THE LAKE SHORE REGION IN THE EVENING
HOURS. PERHAPS THE MODELS ARE PICKING UP A TREND OF A CONVERGENT
REGION DEVELOPING ON THE WEST SIDE OF LAKE MICHIGAN DUE TO THE
STRONGER WINDS ON THE LAKE PULLING AWAY FROM THE AREA. SURFACE
PRESSURE PLOTS SUGGEST A SUBTLE HEIGHT FALL OVER LAKE MICHIGAN AS
WELL. INCREASING UNSTABLE CONDITIONS OVER THE LAKE ALSO DEVELOPING
WITH THE POLAR VORTEX AND BAROCLINIC ZONE APPROACHING. WILL ADD A
SMALL CHANCE FOR SNOW SHOWERS FOR NOW..BUT ITS POSSIBLE THIS MAY
NEED TO BE INCREASED A LITTLE.
UPPER PATTERN GRADUALLY TURNS MORE ZONAL MID WEEK FOR A TURN TO
MORE NORMAL CONDITIONS. A PIECE OF SOUTHERN STREAM ENERGY SLIDES
OVER THE MID MISSISSIPPI VALLEY REGION WEDNESDAY NIGHT INTO
THURSDAY AND ALONG THE H850 FRONTAL BOUNDARY...GLANCING THE SOUTH
HALF OF THE FORECAST REGION WITH LIGHT SNOW. ANOTHER SHORT WAVE
TROUGH MAY SLIDE OVER THE GREAT LAKES REGION FRIDAY NIGHT INTO
SATURDAY FOR ANOTHER CHANCE OF SNOW OR SNOW MIX...OTHERWISE THE
DRIER WESTERLY OR PACIFIC FLOW CONTINUES INTO THE WEEKEND WITH
MODERATING DAY TIME HIGH TEMPERATURES APPROACHING THE LOWER 30S
WITH NO MAJOR WEATHER SYSTEMS NOTED AT THIS TIME.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1010 PM CST SAT JAN 4 2014
ARCTIC AIR WL BE OVERSPREADING THE AREA DURING THE NEXT 24 HRS.
LOW-LEVEL SUBSIDENCE WL GENERATE VFR CONDITIONS TNGT. EXPECT
INCREASING WINDS TOMORROW AFTN AS WAVE RIDES NEWD ALONG THE ARCTIC
FRONT TO OUR E. LOWER CLDS AND SOME FLURRIES EXPECTED BY LATE SUN
AFTN.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING FROM 6 PM SUNDAY TO NOON CST TUESDAY FOR
WIZ005-010>013-018>022-030-031-035>040-045-048>050-073-074.
WIND CHILL ADVISORY FROM 6 AM TO 6 PM CST SUNDAY FOR WIZ013-020-
021-031-037>039-045-048-049-073-074.
WIND CHILL ADVISORY UNTIL 6 PM CST SUNDAY FOR WIZ005-010>012-018-
019-030-035-036.
&&
$$
UPDATE.........SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
422 AM EST TUE JAN 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 417 AM EST TUE JAN 7 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOWS DEEP POLAR VORTEX
CENTERED FM NCENTRAL ONTARIO S INTO THE GRT LKS...WITH DEEP CYC NW
FLOW OF BITTERLY COLD AIR ARND SFC LO PRES IN NRN QUEBEC. H5/H7/H85
TEMPS WITHIN THE CORE OF COLDEST AIR AT 00Z EXTENDING FM NW ONTARIO
INTO MI WERE -45C/-35C/-30C. LLVL NW WINDS ARE UP TO 35-40 KTS PER
THE MQT 88D VWP UNDER THE FAIRLY TIGHT PRES GRADIENT OVER THE UPR
LKS... AND THE COMBINATION OF THE STEADY SFC WINDS AND THE BRUTAL
COLD THAT HAS DROPPED SFC TEMPS TO ARND -20F OVER THE INTERIOR W
HAVE CAUSED WIND CHILLS TO FALL AS LO AS -35F TO -45F OVER THE
ENTIRE CWA EARLY THIS MRNG. LES ALSO PERSISTS IN THE W TO NW WIND SN
BELTS OVER THE W AND NEAR LK SUP E OF PICTURED ROCKS. AN AREA OF
THICKER CLDS AND SOME SPOTTY -SN ARE SPREADING SEWD THRU NW ONTARIO
TOWARD THE UPR LKS IN ASSOCIATION WITH A SHRTWV DIGGING SSEWD IN NW
ONTARIO ON THE WRN FLANK OF THE POLAR VORTEX.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON RECORD LO TEMPS/WIND
CHILLS/LES AND GOING HEADLINES.
TDAY...AREA OF DPVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH SHRTWV
SLIDING SEWD THRU NE LK SUP THIS MRNG WL MAINTAIN DEEPER MSTR/MIXED
LYR AND AID IN MORE WDSPRD LES. THE SHSN WL BE SOMEWHAT HEAVIER OVER
THE E GIVEN LONGER FETCH/OPPORTUNITY FOR MOISTENING OVER THE E NEAR
LK SUP...WHERE SHARPENED LAND BREEZE CNVGC WL BE THE RULE AND SLGTLY
WARMER TEMPS MODIFIED BY LONGER PASSAGE OVER LK SUP WL NOT HAMPER SN
GROWTH AS SGNFTLY AS OVER THE W. FOLLOWING THE PASSAGE OF THE SHRTWV
TO THE E BY THIS AFTN...DNVA/LARGER SCALE QVECTOR DVGC WL
DOMINATE...WITH ACCOMPANYING SUBSIDENCE DRYING THE MID LVLS AND
CAUSING INVRN BASES TO SINK TO 4-5K FT. SO EXPECT LES INTENSITY TO
DIMINISH. DEPARTURE OF CORE OF COLDEST AIR/POLAR VORTEX TO THE NE
INTO QUEBEC THAT CAUSES H85 TEMPS TO RISE FM ARND -25C AT 12Z TO
CLOSER TO -20C BY 00Z WED WL ALLOW TEMPS TO RECOVER A BIT COMPARED
TO MON. IN CONCERT WITH SLACKENING PRES GRADIENT/SLOWLY DIMINISHING
WINDS...WIND CHILLS SHOULD EASE ABV WRNG THRESHOLDS THIS AFTN AND
THE MAGNITUDE OF THE BLSN IN AREAS IMPACTED BY THE LES SHOULD
SUBSIDE A BIT AS WELL. DID EXTEND THE GOING WRNG FOR A FEW HRS OVER
THE INTERIOR W HALF TO ACCOUNT FOR ADVY CRITERIA THAT WL PERSIST
THERE A BIT LONGER INTO THE AFTN.
TNGT...AS THE ARCTIC AIRMASS RETREATS FARTHER TO THE NE...THE PRES
GRADIENT/LLVL WINDS WL SLOWLY SLACKEN AND H85 TEMPS WL RISE TO ARND
-18C BY 12Z WED UNDER GENERAL SUBSIDENCE THAT WL SHARPEN AN INVRN
ARND 3-4K FT. EVEN THOUGH A SLOW WARMING WL ALLOW FOR IMPROVED SN
GROWTH...LOWERING INVRN BASE SHOULD LIMIT LES INTENSITY ESPECIALLY
OVER THE W. WL NOT EXTEND LES ADVYS BEYOND SCHEDULED EXPIRATION AT
00Z THIS EVNG GIVEN THE EXPECTED DIMINISHING SN TRENDS/WINDS THAT WL
ALSO DIMINISH THE MAGNITUDE OF THE BLSN/WIND CHILLS. ALTHOUGH H85
TEMPS WL MODERATE TNGT...SFC TEMPS MAY STILL PLUNGE SHARPLY AOB -20F
AWAY FM LK MODERATION WITH EXPECTATION THAT LARGER SCALE SUBSIDENCE
WL ALLOW FOR MOCLR SKIES IN THE PRESENCE OF LIGHTER WINDS. APRNT
TEMPS MAY REACH THE WIND CHILL ADVY CRITERIA...BUT OVERALL WINDS
SHOULD BE LIGHT ENUF TO JUSTIFY NO EXTENTION OF WIND CHILL HEADLINES
WHERE THE TEMPS FALL MORE SHARPLY AT THE MORE SHELTERED INTERIOR
LOCATIONS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 417 AM EST TUE JAN 7 2014
FOR WED/WED NIGHT...THE CWA WILL BE BETWEEN A SFC LOW MOVING E AND A
SFC HIGH MOVING IN FROM THE W. WHILE INVERSION HEIGHTS WILL
GRADUALLY LOWER THROUGH THE PERIOD...DO NOT EXPECT MUCH CHANGE IN
WNW-NW WIND LES WED AS WARMING TEMPS WILL PUT MORE OF THE LOW LEVELS
IN THE DGZ SO RATIOS WILL BE A BIT BETTER ALONG WITH A SHORTWAVE
MOVING NE OF THE CWA DURING THE AFTERNOON/EVENING WHICH WILL PROVIDE
SOME SYNOPTIC SUPPORT. THESE FACTORS WILL HELP OFFSET LOWERING
INVERSION HEIGHTS. FOR WED NIGHT...EXPECT LES TO LINGER MAINLY OVER
NE UPPER MI AS THE SFC HIGH MOVES S OF THE CWA WHILE DIMINISHING
OVERALL. DID NOT CHANGE FORECAST MUCH AS PREVIOUS FORECAST LOOKED
GOOD AND EXPECTATIONS HAVE NOT CHANGED SIGNIFICANTLY.
THU INTO EARLY SAT IS TRICKY AS A DISTURBANCE MOVES INTO THE PACIFIC
NW WED NIGHT...WITH NRN AND SRN JET STREAM INTERACTIONS CONTRIBUTING
TO THE SYSTEM STRENGTHENING OVER THE WRN CONUS. WITH THESE TYPES OF
NRN AND SRN STREAM INTERACTIONS...THE SITUATION IS ALWAYS MORE
UNCERTAIN AS MODELS HAVE TROUBLE HANDLING ENERGY ALLOCATION. AREA
WIDE SYSTEM SNOW IS A POSSIBILITY AS ENERGY LIFTS NE OUT OF THE
CENTRAL CONUS FRI INTO FRI NIGHT...BUT OVERALL CHANCES AND
DEFINITELY FINE DETAILS ARE FAR FROM CERTAIN. ONE THING MORE CERTAIN
IS THAT SW WINDS THU THROUGH FRI WILL RESULT AS THE HIGH EXITS E AND
THE TROUGH MOVES IN FROM THE W. MODELS ARE HINTING AT SW FLOW LES
OFF LAKE MICHIGAN...BUT WITH WARMING TEMPS AND THE NORMALLY TRICKY
NATURE OF LES IN THAT REGIME...WILL NOT ADD SIGNIFICANT EMPHASIS AT
THIS TIME. AHEAD OF THE TROUGH...MODELS INDICATE 850MB TEMPS
APPROACHING 0C FRI INTO EARLY SAT...WHICH WILL LEAD TO TEMPS RISING
CLOSER TO FREEZING FRI AND SAT.
SUN INTO MON ARE EVEN MORE UNCERTAIN AS MODELS INDICATE A QUICK
HITTING DISTURBANCE GENERALLY MOVING ALONG THE US/CANADIAN
BORDER...BUT DETAILS WITH THIS SYSTEM ARE FAR FROM CERTAIN...EVEN
GIVEN THE CURRENT GENERAL MODEL AGREEMENT. BEST THAT CAN BE SAID AT
THIS POINT IS THAT THERE IS POTENTIAL FOR A STRONGER SYSTEM TO MOVE
THROUGH OR NEAR THE REGION AND AT LEAST A QUICK SHOT OF WARMER TEMPS
AROUND FREEZING IS POSSIBLE. USED A GENERAL CONSENSUS OF GUIDANCE
FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1222 AM EST TUE JAN 7 2014
AN EXTREMELY COLD AIR MASS MOVING ACROSS THE UPPER GREAT LAKES WILL
CONTINUE TO GENERATE LAKE EFFECT SNOW SHOWERS OFF LAKE SUPERIOR.
WITH WNW FLOW...MAINLY KCMX WILL BE IMPACTED BY SNOW.
THE COMBINATION OF FALLING AND BLOWING OF THE SMALL SNOWFLAKES AT
WILL RESULT IN PREVAILING VLIFR CONDITIONS AT KCMX. KIWD IS EXPECTED
TO REMAIN ON THE EDGE OF THE LAKE EFFECT SNOW BANDS BUT SHOULD STILL
SEE ENOUGH LIGHT SNOW FOR MAINLY MVFR CONDITIONS. SOME
IMPROVEMENT WILL BE POSSIBLE AT KCMX BY TUE AFTERNOON AS WINDS
DIMINISH SLOWLY AND DEEPER MOISTURE DEPARTS/INVERSIONS
FALL...RESULTING IN DIMINISHING LAKE EFFECT SNOW SHOWERS. VFR
CONDITIONS WILL PREDOMINATE AT KSAW WITH A DOWNSLOPE WNW WIND
COMPONENT.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 AM EST TUE JAN 7 2014
EXPECT NW GALES TO 35-40 KTS OVER PORTIONS OF THE EASTERN AND
CENTRAL LAKE TO DIMINISH TO 30 KTS BY THIS EVENING AS THE PRES
GRADIENT OVER THE UPPER LAKES SLACKENS...SO DROPPED THE GOING GALE
WARNING AT 00Z WED. ALTHOUGH WINDS/WAVES WILL SLOWLY DIMINISH THRU
TONIGHT...THE COMBINATION OF THE ARCTIC COLD AND SUFFICIENT WAVE
ACTION WILL RESULT IN CONTINUED WIDESPREAD HEAVY FREEZING SPRAY. A
HIGH PRESSURE SYSTEM MOVING THROUGH LATE WEDNESDAY INTO WEDNESDAY
NIGHT WILL DECREASE WINDS...CAUSING HEAVY FREEZING SPRAY TO DIMINISH.
AS THE HIGH EXITS EAST WHILE LOW PRESSURE MOVES IN FROM THE WEST ON
THURSDAY AND FRIDAY...EXPECT AN INCREASE IN WARMER SW WINDS INTO
EARLY SATURDAY. THE AREA OF LOW PRESSURE WILL PASS THROUGH EARLY
SATURDAY...LEADING TO WESTERLY WINDS THROUGH THE REST OF THE DAY
SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 2 PM EST /1 PM CST/ THIS AFTERNOON FOR
MIZ002-004-005-009>011-084.
WIND CHILL WARNING UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ001-003-006-007-012>014-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
MIZ001>003-006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-243>245-248>251-263>267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...JLB
MARINE...KC
AREA FORECAST DISCUSSION
NWS DULUTH MN
353 AM CST TUE JAN 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 350 AM CST TUE JAN 7 2014
THE VERY COLD CONDITIONS TODAY AND TONIGHT REMAIN THE FOCUS OF
ATTENTION IN THE SHORT TERM. SCATTERED FLURRIES ARE POSSIBLE ACROSS
THE ARROWHEAD THIS MORNING...WITH LIGHT LAKE EFFECT SNOW SHOWERS
ALONG THE SOUTH SHORE FROM PORT WING TO SAXON THROUGH THIS
AFTERNOON. TEMPERATURES WILL BEGIN A GRADUAL WARM UP DURING THE DAY
TOMORROW.
COLD ARCTIC UPPER LOW OVER ONTARIO CONTINUES TO ROTATE TO THE
EAST/NE THIS MORNING AS THE SFC RIDGE AXIS...EXTENDING FROM THE
NORTHWEST TERRITORIES SEWD INTO THE ERN DAKOTAS...SLIDES SLOWLY TO
THE EAST. A WEAK BOUNDARY OVER SERN MANITOBA AND WRN ONTARIO WILL
DROP SWD THROUGH THE ARROWHEAD AND WRN GREAT LAKES AREA THIS MORNING
AND TRIGGER A FEW SCATTERED FLURRIES ACROSS THE REGION.
THE BULK OF THE POLAR AIR HAS SHIFTED TO THE EAST THIS MORNING.
HOWEVER...THERE IS STILL ENOUGH COLD AIR TO DROP TEMPERATURES INTO
THE UPPER TEENS AND 20S BELOW ZERO...AND WITH W WINDS 5 TO 15
MPH...WIND CHILL VALUES REMAIN IN THE -30 TO -45 DEG F RANGE. WIND
CHILL WARNINGS REMAIN IN EFFECT THROUGH NOON TODAY...WITH SECTIONS
OF CENTRAL MN DOWNGRADED TO AN ADVISORY WHERE TEMPS HAVE WARMED
SLIGHTLY AND WINDS HAVE DIMINISHED. OVERALL TEMPERATURES SHOULD
RECOVER TODAY INTO THE SINGLE DIGITS AND TEENS BELOW ZERO...AND
WINDS ARE EXPECTED TO REMAIN STEADY OR WEAKEN AS THE SFC PRES
GRADIENT RELAXES AND HIGH PRESSURE BUILDS IN FROM THE WEST.
TEMPERATURES WILL BE SOMEWHAT TRICKY TONIGHT WITH THE CENTER OF HIGH
PRESSURE MOVING INTO SRN/CENTRAL MN...AND SKIES CLEARING OUT.
RADIATIONAL COOLING WILL BE THE MAIN FACTOR IN DROPPING TEMPS
TONIGHT INTO THE 20S AND LOWER 30S BELOW ZERO. NOT SURE THE
DETERMINISTIC RUNS OF THE GFS NAM OR ECMWF ARE PICKING UP ON THIS
TOO WELL. THE 00Z RUN OF THE GEM IS THE ONLY SHOWING THE COLDEST
AREA ALIGNED WITH THE RIDGE...WITH LOWS 30 TO 35 BELOW ZERO FROM
FARGO/GRAND FORKS TO THE TWIN CITIES...AND AROUND -30 AT BRAINERD
AND HINCKLEY...WITH SLIGHTLY WARMER TEMPS ALONG THE INTL BORDER.
WINDS WILL BE MUCH LIGHTER TO THE SOUTH ALONG THE RIDGE AXIS...AND
REMAIN 5 TO 10 MPH TO THE NORTH WHERE A WEAK GRADIENT WILL LINGER.
SO...WIND CHILL VALUES WILL LIKELY FALL INTO ADVISORY AND WARNING
CRITERIA LEVELS ONCE AGAIN...-40S NORTH...-30S SOUTH. ANOTHER ROUND
OF WIND CHILL HEADLINES IS EXPECTED AGAIN TONIGHT...BUT WILL LET THE
WIND CHILL WARNINGS AND ADVISORY THIS MORNING CONTINUE BEFORE
ISSUING ADDITIONAL ADVISORIES/WARNINGS.
TEMPERATURES ON WEDNESDAY WILL RISE IN THE LATE MORNING AND
AFTERNOON INTO THE SINGLE DIGITS ABOVE AND BELOW ZERO...UNDER MOSTLY
SUNNY SKIES AND LIGHT WEST WINDS. ADDITIONAL WARMING CONTINUES
THROUGH THE LATTER HALF OF THE WEEK.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 350 AM CST TUE JAN 7 2014
WEDNESDAY NIGHT THROUGH THURSDAY A NICE SHORTWAVE WILL MOVE ACROSS
THE US/CANADIAN BORDER...PUSHING A BAND OF WARM AIR ADVECTION ACROSS
THE CWA ON THURSDAY. THIS SHOULD BRING A BAND OF LIGHT SNOW...WITH
HIGH TEMPS 10 TO 15 ABOVE NEARLY EVERYWHERE. THIS SHORTWAVE IS
FARTHER NORTH AND SLOWER THAN ON PREVIOUS RUNS...SO HAVE ADJUSTED
THE POPS NORTH A LITTLE. EVEN SO...IF THE MODELS MAINTAIN
CONTINUITY ON THIS WAVE...POPS WILL NEED TO BE INCREASED.
THURSDAY NIGHT BEGINS A PERIODS OF NEAR TO ABOVE NORMAL TEMPERATURES
WITH A FEW SHORTWAVES BRINGING PERIODS OF LIGHT SNOW. THE UPPER
LEVEL FLOW TURNS MORE ZONAL THAN IT IS NOW...WITH A STRONG OR CUT
OFF UPPER LOW OVER NORTHERN MEXICO...DEPENDING ON THE MODEL. MODELS
ARE STILL SHOWING SIGNIFICANT DIFFERENCES...THOUGH THE GIST OF THE
PATTERN IS GENERALLY THE SAME. A TROUGH AXIS IS EXPECTED TO SWING
THROUGH THE AREA ON FRIDAY...AND INTERACT WITH A PLUME OF WARM MOIST
AIR. THE BULK OF THIS SYSTEM MISSES THE FORECAST AREA TO THE
SOUTHEAST...BUT SHOULD BRING SOME LIGHT SNOW TO PORTIONS OF
NORTHWEST WISCONSIN FRIDAY AFTERNOON AND EVENING. MODELS ARE
BRINGING SOME 850MB TEMPS NEAR OR JUST ABOVE ZERO INTO THE AREA WITH
THIS WAVE. WHILE THIS DOES NOT APPEAR LIKELY AT THIS TIME...WILL BE
MONITORING FOR THE POTENTIAL FOR WARMER AIR AND MIXED PRECIP TYPES
WITH THIS SYSTEM. TEMPERATURES FRIDAY TO RISE INTO THE UPPER 20S TO
AROUND 30...WITH TEENS TO AROUND 20 FRIDAY NIGHT. SATURDAY NIGHT
AND SUNDAY WE HAVE MORE CHANCES FOR PRECIPITATION WITH A POTENT
SHORTWAVE AND SURFACE LOW MOVING THROUGH THE NORTHERN
STREAM...NEARLY ZONAL FLOW. AGAIN...SOME FAIRLY WARM AIR BEING
DRAWN INTO THIS SYSTEM...SO WILL HAVE TO WATCH FOR MIXED PRECIP TYPE
ISSUES. HIGHS SUNDAY SHOULD BE IN THE 20S AND LOW 30S...BUT COLDER
AIR WILL COME BACK FOR MONDAY WITH HIGHS BACK INTO THE 20S.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CST MON JAN 6 2014
LATEST SATELLITE AND OBSERVATIONS SHOW MORE CLOUDS WILL AFFECT THE
CWA TONIGHT...WITH MORE MVFR CEILINGS. MOST TAF SITES WILL
EXPERIENCE AT LEAST SOME MVFR CEILINGS. THE MODELS ARE NOT DOING
A GOOD JOB DEPICTING THESE CLOUDS...AND WE USED A COMBINATION OF
THE RAP AND EXTRAPOLATION FROM SATELLITE/OBS OVER THE NEXT 6 TO 12
HOURS. THE RAP DOES SHOW THE BEST LOW LEVEL MOISTURE LINGERING
OVER FAR NORTHERN MINNESOTA THE LONGEST AND THAT WOULD IMPACT
KINL/KHIB. WINDS WILL GRADUALLY DIMINISH THROUGH THE
PERIOD...ESPECIALLY LATE TUESDAY AFTERNOON/EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH -9 -21 0 -15 / 0 0 0 0
INL -12 -30 -3 -18 / 0 0 0 10
BRD -3 -24 1 -16 / 0 0 0 0
HYR -8 -23 3 -17 / 0 0 0 0
ASX -7 -18 3 -12 / 0 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL WARNING UNTIL NOON CST TODAY FOR MNZ010>012-018>021-
025-026-033>038.
WI...WIND CHILL WARNING UNTIL NOON CST TODAY FOR WIZ001>004-006>009.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ121-
140>148.
&&
$$
SHORT TERM...BJT
LONG TERM...LE
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS DULUTH MN
1136 PM CST MON JAN 6 2014
.UPDATE...
ISSUED AT 1135 PM CST MON JAN 6 2014
ANOTHER COLD NIGHT ACROSS THE NORTHLAND...WITH 11 PM OBSERVATIONS
FROM 20 TO 26 BELOW ACROSS MOST OF THE AREA. WE HAVE MADE SOME
ADJUSTMENTS TO THE GRIDS LATE THIS EVENING...MAINLY INCREASED
CLOUD COVER AS SATELLITE AND OBSERVATIONS SHOWS MORE CLOUDS
NEARING OR JUST ENTERING OUR WESTERN ZONES...WITH MORE IN THE
ARROWHEAD. THE MODELS ARE NOT HANDLING THIS CLOUD COVER VERY
WELL...BUT IT DOES APPEAR IT WILL HOLD IN THROUGH MUCH OF TUESDAY
MORNING AT LEAST.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 309 PM CST MON JAN 6 2014
THE NORTHLAND CAN CONTINUE TO EXPECT THE BITTERLY COLD WEATHER
WITH VERY DANGEROUS WIND CHILLS TO CONTINUE INTO TOMORROW. THE
PARTLY CLEAR SKIES TONIGHT WILL HELP TEMPERATURES TO DROP TO
AROUND -30 DEGREES ACROSS MOST OF THE FORECAST AREA TONIGHT. THE
GFS AND NAM MOS GUIDANCE WERE IN GOOD AGREEMENT. THE SKIES COULD
BE CLOUDIER THOUGH DEPENDING ON IF SOME CLOUDS STREAMING SOUTH OUT
OF MANITOBA AND WESTERN ONTARIO CAN HOLD TOGETHER TONIGHT...SO
SOME AREAS COULD BE A BIT WARMER. THE NW WINDS WILL CONTINUE TO
CAUSE WIDESPREAD WIND CHILLS OF 45 TO 55 DEGREES BELOW ZERO UNTIL
LATE TUESDAY MORNING WHEN CONDITIONS IMPROVE. HOWEVER...WE WILL
PROBABLY NEED WIND CHILL ADVISORIES FOR PARTS OF THE NORTHLAND
TOMORROW DUE TO WIND CHILLS OF 25 TO 35 DEGREES BELOW ZERO THROUGH
THE REST OF THE DAY. DAYTIME HIGH TEMPERATURES ON TUESDAY SHOULD
BE A FEW TO SEVERAL DEGREES WARMER THAN TODAY AS THE 850 HPA
TEMPERATURES OVER THE REGION WARM UP ABOUT 8 TO 12 DEGREES FROM
TODAY TO TOMORROW AFTERNOON.
THERE MAY BE SOME LINGERING LIGHT LAKE EFFECT SNOW SHOWERS ALONG
THE SOUTH SHORE IN NW WISCONSIN THROUGH AT LEAST TOMORROW MORNING.
THE WESTERLY WIND DIRECTION DOES NOT FAVOR SIGNIFICANT SNOW FOR
ANY PARTS OF THE NORTHLAND.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 309 PM CST MON JAN 6 2014
THE ARCTIC ORIGIN AIRMASS WILL CONTINUE ITS HOLD ON THE NORTHLAND
TUESDAY NIGHT...WITH OVERNIGHT LOWS EXPECTED TO BE DEEPLY INTO
THE 20 TO 30 BELOW ZERO RANGE ONCE AGAIN. SOME 30S BELOW ZERO ARE
EXPECTED IN THE NORTH WITH HIGH PRESSURE SETTLING INTO THE RED
RIVER VALLEY REGION BY 12Z WEDNESDAY. TEMPERATURES SHOULD REACH
RIGHT AROUND ZERO FOR DAYTIME HIGHS ON WEDNESDAY...AND MAY TOP
ZERO IN THE SOUTH. IT IS AT ABOUT THIS POINT THAT WE START TIPPING
BACK IN THE OTHER DIRECTION AND TEMPERATURES RISE ABOVE ZERO.
TEMPERATURES WILL AGAIN BE QUITE COOL WEDNESDAY NIGHT...WITH LOWS
IN THE TEENS AND 20S BELOW ZERO...BUT A BIG WARMUP IS STILL IN
STORE FOR LATE IN THE WEEK AND INTO THE WEEKEND. BY MIDWEEK WE
TRANSITION TO A MORE ZONAL FLOW...WITH AN UPPER LEVEL RIDGE
DEVELOPING ACROSS THE NORTHLAND BY THE WEEKEND. THIS SHOULD SET US
UP FOR A PRETTY DRAMATIC JANUARY THAW. HIGH TEMPERATURES ON
THURSDAY SHOULD BE IN THE 10 TO 12 ABOVE RANGE...WITH OVERNIGHT
LOWS STAYING ABOVE ZERO THURSDAY NIGHT WITH CLOUDS AND WAA
CONTINUING. HIGHS ON FRIDAY WILL BE IN THE 20S...WITH HIGHS AROUND
30 ON SUNDAY. NOTHING MAJOR IS EXPECTED IN THE WAY OF
PRECIPITATION...BUT THE GFS DOES HINT AT A LITTLE MORE WELL
DEFINED SYSTEM ON FRIDAY SO WILL KEEP AN EYE OUT FOR THAT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1135 PM CST MON JAN 6 2014
LATEST SATELLITE AND OBSERVATIONS SHOW MORE CLOUDS WILL AFFECT THE
CWA TONIGHT...WITH MORE MVFR CEILINGS. MOST TAF SITES WILL
EXPERIENCE AT LEAST SOME MVFR CEILINGS. THE MODELS ARE NOT DOING
A GOOD JOB DEPICTING THESE CLOUDS...AND WE USED A COMBINATION OF
THE RAP AND EXTRAPOLATION FROM SATELLITE/OBS OVER THE NEXT 6 TO 12
HOURS. THE RAP DOES SHOW THE BEST LOW LEVEL MOISTURE LINGERING
OVER FAR NORTHERN MINNESOTA THE LONGEST AND THAT WOULD IMPACT
KINL/KHIB. WINDS WILL GRADUALLY DIMINISH THROUGH THE
PERIOD...ESPECIALLY LATE TUESDAY AFTERNOON/EVENING.
&&
.PRELIMINARY POINT TEMPS/POPS...
DLH -29 -6 -19 1 / 0 0 0 0
INL -31 -12 -29 -3 / 0 0 0 0
BRD -29 -3 -23 1 / 0 0 0 0
HYR -29 -6 -21 3 / 10 0 0 0
ASX -24 -4 -19 5 / 20 0 0 0
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR MNZ010>012-018>021-
025-026-033>038.
WI...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ001>004-006>009.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST TUESDAY FOR LSZ121-140>148.
&&
$$
UPDATE...MELDE
SHORT TERM...GROCHOCINSKI
LONG TERM...DAP
AVIATION...MELDE
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
348 AM EST TUE JAN 7 2014
.SYNOPSIS...
VERY COLD AND WINDY CONDITIONS WILL BE IN PLACE ACROSS THE NORTH
COUNTRY TODAY AND TONIGHT...WITH DANGEROUSLY LOW WIND CHILL VALUES
THIS MORNING...ESPECIALLY ACROSS NORTHERN NEW YORK. LOW-LEVEL
MOISTURE FROM THE GREAT LAKES WILL BRING VARIABLY CLOUDY CONDITIONS
AND SCATTERED SNOW SHOWER ACTIVITY. MOST OF THE SNOW SHOWER ACTIVITY
WILL BE LIGHT...BUT SOME HEAVIER LAKE EFFECT SNOW BANDS OFF LAKE
ONTARIO ARE EXPECTED TO LOCALLY AFFECT SOUTHERN PARTS OF ST.
LAWRENCE COUNTY INTO PORTIONS OF THE ADIRONDACKS STARTING THIS
AFTERNOON AND LASTING INTO WEDNESDAY MORNING. WEST WINDS WILL
GRADUALLY DIMINISH ACROSS THE REGION ON WEDNESDAY...WITH A TREND
TOWARD MODERATING TEMPERATURES STARTING THURSDAY AND THROUGH THE
UPCOMING WEEKEND. THE NEXT CHANCE FOR SIGNIFICANT PRECIPITATION
ARRIVES WITH A FRONTAL SYSTEM LATE SATURDAY INTO SATURDAY NIGHT.
AT THIS TIME...IT APPEARS PRECIPITATION WILL PREDOMINANTLY BE IN
THE FORM OF RAIN.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 330 AM EST TUESDAY...ONLY CHANGE TO ONGOING HEADLINES WAS TO
EXTEND THE WIND CHILL ADVISORY ACROSS THE NRN ADIRONDACKS AND ST.
LAWRENCE VALLEY THRU NOON TODAY (17Z)...BASED ON 20 BELOW READINGS
LASTING A COUPLE HOURS LONGER THAN PREVIOUSLY FORECAST ACROSS THE
LOWER ELEVATIONS. THE LAKE EFFECT SNOW ADVISORY...FOR LAKE EFFECT
REDEVELOPING NORTHWARD THIS AFTN...CONTINUES FOR SERN ST. LAWRENCE
COUNTY THRU 12Z WED.
UNUSUALLY DEEP 500MB TROUGH IS LIFTING NEWD FROM SERN ONTARIO
AND ACROSS NY EARLY THIS MORNING...WITH 500MB HEIGHT VALUES BELOW
500DM PER LATEST RUC ANALYSIS VCNTY OF LAKE ONTARIO. STRONG LOW-
LEVEL CAA CONTINUES EARLY THIS MORNING ACROSS THE NORTH COUNTRY WITH
850MB TEMPS DROPPING TO -22 TO -24C AND 1000-500MB THICKNESS
VALUES FALLING TO AROUND 490DM BY MID-MORNING. LOW-LEVEL
TRAJECTORIES FROM THE GREAT LAKES ARE RESULTING IN SOME MODERATION
OF THE AIR MASS...SO TEMPERATURES WON/T RIVAL LAST WEEK/S COLD
SNAP (WHEN HIGH TEMPS WERE BELOW ZERO ON JANUARY 2ND AND 3RD).
DESPITE THAT...LAPSE RATES ARE NEAR DRY ADIABATIC FROM THE SFC-
750MB...WHICH IS QUITE DEEP FOR JANUARY. STEEP LAPSE RATES
COMBINED WITH A STRONG WESTERLY GRADIENT FLOW BETWEEN SFC HIGH
PRESSURE OVER THE TN RIVER VALLEY AND DEEP SFC LOW PRESSURE EAST
OF HUDSON BAY WILL RESULT IN MODERATELY STRONG AND GUSTY WINDS
CONTINUING ALL AREAS THRU THE DAYLIGHT HRS TODAY. LOOKING AT WSW
SURFACE WINDS OF 15-25 MPH WITH GUSTS TO 35 MPH. THIS WILL RESULT
IN VERY LOW WIND CHILL VALUES...AND IT CONTINUES TO APPEAR THAT
WE/LL MEET WIND CHILL ADVISORY CRITERIA OF 20 BELOW ACROSS THE NRN
ADIRONDACKS AND ST. LAWRENCE VALLEY FOR A TIME THIS MORNING. WIND
CHILLS GENERALLY 5 TO 15 BELOW ACROSS VT THIS AM. DAYTIME HIGH
TEMPERATURES WILL RANGE FROM THE LOW TEENS IN THE CHAMPLAIN VALLEY
TO THE SINGLE DIGITS ACROSS THE NRN ADIRONDACKS AND MUCH OF
N-CENTRAL AND NERN VT. GENERALLY TRENDED TOWARD THE COLDER SIDE OF
MOS GUIDANCE BASED ON UPSTREAM OBSERVATIONS.
CONCERNING PRECIPITATION...IT APPEARS THAT A SECONDARY COLD FRONT
PASSES THRU AROUND 09Z WITH SOME LIGHT ADDITIONAL SNOW SHOWER
ACTIVITY. ANY ACCUMULATION ASSOCIATED WITH THE BDNRY SHOULD BE UNDER
AN INCH. VEERING WINDS BRIEFLY SHIFTS LAKE ONTARIO SNOW BAND SOUTH
OF OUR CWA THIS MORNING. HOWEVER...THE BTV 4KM AND 12KM WRF MODELS
INDICATE THE BAND WILL OSCILLATE BACK NWD WITH LAKE EFFECT SNOW
BANDS RETURNING TO SRN ST. LAWRENCE INTO SRN FRANKLIN/WRN ESSEX NY
COUNTIES BETWEEN 15Z AND 18Z. ALSO NOTING THAT 850MB FLOW IS 35 TO
40 KTS...SO BAND COULD EXTEND DOWNSTREAM A SIGNIFICANT
DISTANCE...EVEN BRINGING SOME OCCASIONAL FLURRIES OR SNOW SHOWERS
ACROSS THE CHAMPLAIN VALLEY AND UPSLOPE INTO THE CENTRAL/NRN
GREENS FROM TIME TO TIME THIS AFTN/EVE. MAIN IMPACT TO ROAD
CONDITIONS WILL BE LOCALIZED TO SRN ST. LAWRENCE CO. SNOW COULD
BE LOCALLY HEAVY AT TIMES ALONG AND SOUTH OF THE NY ROUTE 3
CORRIDOR FROM BACKUS TO CRANBERRY LAKE TO TUPPER LAKE. WILL
MAINTAIN THE LAKE EFFECT SNOW ADVISORY ACROSS SERN ST. LAWRENCE
COUNTY FOR WHERE ADDITION ACCUMULATIONS AROUND 4" ARE POSSIBLE
BETWEEN 15-00Z TODAY. SNOW-TO-LIQUID RATIOS WILL GENERALLY BE
AROUND 20:1.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH THURSDAY/...
AS OF 330 AM EST TUESDAY...LAKE EFFECT SNOW BANDS WILL CONTINUE
PERIODICALLY IMPACT SRN ST. LAWRENCE COUNTY INTO THE NRN
ADIRONDACKS THROUGH MUCH OF TONIGHT. IT APPEARS BASED ON 4 AND
12KM BTV-WRF SOLNS THAT INTENSITY OF LAKE EFFECT BANDS INTO OUR
CWA WILL LESSEN AFTER 09Z WED. THUS...THE CURRENT ENDING TIME OF
THE ADVISORY AT 12Z WED CONTINUES TO LOOK GOOD. ANTICIPATE SOME
LOCAL ACCUMULATIONS OF 6-8" BY THE TIME THE EVENT ENDS...MAINLY
ALONG AND SOUTH OF NY STATE HIGHWAY 3. ELSEHWERE ACROSS THE
FORECAST AREA...DIMINISHING COVERAGE OF ANY FLURRY ACTIVITY. WSWLY
FLOW FROM THE GREAT LAKES SUGGESTS MOSTLY CLOUDY CONDITIONS...AND
WITH WINDS REMAINING 10-15 MPH...NOT MUCH PROSPECT FOR RADIATIONAL
COOLING TONIGHT. THIS WILL KEEP LOWS GENERALLY IN THE SINGLE
DIGITS ABOVE ZERO...BUT LOCALLY 0 TO -5F ACROSS N-CENTRAL AND NERN
VT AND WITHIN THE ADIRONDACK REGION BETWEEN 1500 AND 2000 FT.
GRADIENT FLOW RELAXES A BIT ON WEDNESDAY...SO WIND CHILL VALUES
WILL BE LESS SEVERE. SOME LAKE EFFECT SNOW SHOWERS ARE STILL
POSSIBLE FOR SRN ST. LAWRENCE AND FRANKLIN COUNTIES...THOUGH
INTENSITY SHOULD BE LESS. A FEW FLURRIES POSSIBLE ELSEWHERE.
STAYED NEAR MOS CONSENSUS ON TEMPS...GENERALLY MID TO UPPER TEENS
FOR AFTN HIGHS...SO A SLIGHT MODERATION FROM EXPECTED HIGHS
TUESDAY.
DURING WEDNESDAY NIGHT...BOTH THE 00Z GFS AND NAM INDICATE THAT A
NORTHERN STREAM SHORTWAVE TROUGH WILL GRAZE THE NRN ZONES. LITTLE IN
THE WAY OF A SFC REFLECTION OR LOW-LEVEL CONVERGENCE...AND AIR MASS
REMAINS QUITE DRY WITH PW VALUES AROUND 0.1 IN. SATURATED LAYER IN
NAM MODEL SOUNDINGS 4-7 KFT LIKELY INDICATIVE OF CLOUD COVER...SO
WILL INDICATE MOSTLY CLOUDY BUT DRY CONDITIONS. LOWS WILL BE
SEASONABLY COLD AND GENERALLY IN THE SINGLE DIGITS ABOVE ZERO...AND
LOCALLY IN THE LOWER TEENS IN THE CHAMPLAIN VALLEY.
SURFACE ANTICYCLONE BUILDS DIRECTLY OVERHEAD DURING THE DAY
THURSDAY. INCREASED SUBSIDENCE DRIES OUT THE COLUMN WITH 1000-500MB
RH VALUES FALLING INTO THE 20-30 PERCENT RANGE. IT ALSO APPEARS THAT
850-700MB FLOW VEERS FROM WSW TO NWLY DURING THE DAYLIGHT HRS...SO
THERE WILL BE LESS IMPACT OF MOISTURE/CLOUDINESS FROM THE GREAT
LAKES. THUS...WILL INDICATE DIMINISHING CLOUDINESS AND MOSTLY SUNNY
FOR THURSDAY AFTN. WINDS WILL BE LIGHT W-NW DURING THE DAYLIGHT HRS
AND AFTN HIGH TEMPS SHOULD REACH THE LOW-MID 20S...AS GRADUAL AIR
MASS MODERATING COMMENCES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 330 AM EST TUESDAY...SFC HIGH PRESSURE WILL SLIDE OFF THE SRN
NEW ENGLAND COAST...BRINGING SW FLOW AND WAA OVER THE NORTH COUNTRY
THURSDAY THROUGH FRIDAY NIGHT/SATURDAY. TEMPERATURES WILL BE
NOTICEABLY WARMER WITH MAX TEMPS IN THE M20S-L30S FRIDAY...WARMING
TO THE M30S-L40S ON SATURDAY. MIN TEMPS WILL WARM FROM 0F TO 15F ON
THURSDAY NIGHT TO THE UPPER TEENS AND M20S FRIDAY NIGHT.
LATE FRIDAY NIGHT INTO SATURDAY WILL SEE AN INCREASING THREAT OF
PRECIPITATION AS AN UPPER LVL TROUGH APPROACHES FROM CENTRAL CANADA.
THIS TROUGH WILL BE ASSOCIATED WITH A SFC LOW PRESSURE SYSTEM NEAR
HUDSONS BAY WITH A FRONTAL SYSTEM DRAPING SWD THRU THE GREAT LAKES
REGION INTO THE MISSISSIPPI VALLEY. WAA AHEAD OF THE FRONT WILL
BRING ABOVE FREEZING TEMPS IN ALOFT SATURDAY MORNING...WHILE COLD
AIR IS DIFFICULT TO ERODE AT THE SFC...RESULTING IN POTENTIAL FOR
SEVERAL HRS OF FZRA. BY THE EARLY AFTN...IT LOOKS LIKE THE WARM AIR
WILL HAVE INFILTRATED THE BL...TRANSITIONING ALL PRECIP TO RAIN.
AS THE COLD FRONT MOVES W TO E ACROSS THE REGION LATE
SATURDAY/SATURDAY NT...PRECIP WILL TAPER OFF AS COLDER AIR FILTERS
IN...TRANSITIONING TO A RAIN/SNOW MIX TO ALL SNOW. LITTLE TO NO SN
FALL ACCUMULATION EXPECTED AT THIS PT AS PRECIP LOOKS TO MOSTLY END
BEFORE COLD AIR REALLY SETTLES IN. SLIGHTLY COOLER TEMPS WILL RESIDE
OVER THE NORTH COUNTRY WITH MAX TEMPS IN THE M30S-NEAR 40 AND MIN
TEMPS IN THE 20S TO NEAR 30.
ANOTHER UPPER LVL TROUGH WILL APPROACH FROM THE WEST...TO BRING MORE
PRECIP TO THE NORTH COUNTRY EARLY NEXT WEEK.
&&
.AVIATION /09Z TUESDAY THROUGH SATURDAY/...
THROUGH 06Z WEDNESDAY...GUSTY WEST WINDS WILL PERSIST WITH LAKE
EFFECT SNOW SHOWERS MAINLY AFFECTING KSLK/KMSS WITH SOME ENHANCED
OROGRAPHIC SNOW AT KMPV AND MVFR/IFR CONDITIONS AT THESE SITES.
SLIGHT TROUGHING AT 700MB WILL DISRUPT SW FLOW...BRINGING A
PERIOD OF MORE WESTERLY FLOW AND SHIFTING LAKE EFFECT BAND
SOUTHWARD FOR A FEW HRS THIS MORNING. TIMING OF PROGRESSION OF
THIS TROUGH HAS SOME UNCERTAINTY...EXPECT FLOW ALOFT TO RETURN TO
MORE SW ORIENTATION BTWN 08Z AND 10Z...RETURNING MVFR/IFR
CONDITIONS TO KSLK...PSBLY KMSS AS WELL.
AFTER DAYBREAK TUESDAY...FLOW AT 850MB INCREASES...PSBLY ALLOWING
FOR SOME FLURRIES/-SHSN IN THE CPV WITH DETERIORATING CONDITIONS
AT KSLK IN LAKE EFFECT SNOW. KMPV WILL SEE A RETURN TO MVFR/IFR
CONDITIONS IN SNOW DURING THE MID-LATE MORNING. THIS INCREASE IN
FLOW WILL BE REFLECTED AT THE SFC WITH WINDS INCREASING AT
15-25KTS AND GUSTS IN EXCESS OF 30KTS PSBL.
OUTLOOK 06Z WEDNESDAY THROUGH SATURDAY...
06Z WEDNESDAY THRU 00Z THURSDAY...PERSISTENT LOW-LEVEL WESTERLY
FLOW FROM THE GREAT LAKES COMBINED WITH ARCTIC AIR MASS WILL
MAINTAIN PERIODS OF MVFR/IFR CEILINGS WITH OCCASIONAL SNOW SHOWER
ACTIVITY. DUE TO LAKE EFFECT BANDS...SNOW SHOWERS WILL LIKELY BE
MOST PERSISTENT AT KSLK.
00Z THURSDAY THRU 06Z FRIDAY...CONDITIONS SHOULD GENERALLY
IMPROVE TO VFR AS HIGH PRESSURE BUILDS ACROSS THE AREA LATE
WEDNESDAY THRU THURSDAY.
06Z FRIDAY ONWARD...A WARM FRONT MOVING NEWD WILL BRING A CHANCE
OF LIGHT SNOW AND MVFR CONDITIONS THURSDAY NIGHT...FOLLOWED BY A
COLD FRONT FRIDAY NIGHT INTO SATURDAY WITH VFR/MVFR MIX IN
-RW/-SW SATURDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR NYZ026-027-
029>031-034-087.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR NYZ029.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
206 AM EST TUE JAN 7 2014
.SYNOPSIS...
AN ARCTIC AIRMASS WILL RESIDE OVER THE REGION THROUGH WEDNESDAY
NIGHT. DANGEROUSLY COLD WIND CHILLS ARE LIKELY TONIGHT THROUGH
TUESDAY. THE CORE OF THE ARCTIC AIR MASS WILL MOVE NORTHEAST OF
THE REGION BY THURSDAY WITH MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TODAY/...
1145 PM UPDATE...
QUICK UPDATE TO LWR TEMPS SOME MORE AS HORNELL NY IS NOW DOWN TO
-2F AS OF 04Z. HV OPTED TO COMBINE CURRENT FCST TEMPS WITH LATEST
RAP AS RAP IS DROPPING THEM OFF CLOSER TO REALITY. THUS THINK THAT
OVRNGT MINS, ON AVERAGE, WL BE ABOUT 1-3 DEGREES CLDR THAN FCST.
IN ADDITION, HV ADJUSTED POPS ACRS NRN ONEIDA CNTY TO RMV POPS FOR
THE TIME BEING. EXPECT SNOW SHOWERS WILL DROP INTO NRN ONEIDA CNTY
AFT 07Z AS UL WV PASSES.
1005 PM UPDATE...
WITHIN THE PAST TWO HOURS...A NICE SQUALL DEVELOPED ACROSS THE
CENTRAL SOUTHERN TIER THAT LED TO A PERIOD OF WHITEOUT CONDITIONS
ACROSS THE GREATER BINGHAMTON AREA AND POINTS EAST. THIS
ACTIVITY...STILL READILY APPARENT ON RADAR...IS RAPIDLY MOVING
THROUGH THE WESTERN CATSKILLS ATTM. LOCAL SCANNER BROADCASTS
INDICATE NUMEROUS ACCIDENTS WITHIN THE BINGHAMTON AREA AS ROADS
QUICKLY ICED UP...AND REPORTS OF ALMOST 3" HAVE BEEN RECEIVED
ACROSS BROOME COUNTY.
SO WITH THIS NEARLY GONE...ATTENTION SHIFTS BACK TO ONGOING LAKE
EFFECT ACTIVITY EAST OF LAKE ONTARIO. OVER THE PAST FEW
HRS...SOUTHWEST FLOW HAS CARRIED THE BAND FURTHER AND FURTHER
NORTH AS CYCLONIC LOW-LEVEL FLOW IN ADVANCE OF MAIN MID-LEVEL
VORTEX DESCENDS UPON THE REGION. THAT SAID...MODELS STILL INDICATE
BAND WILL TEMPORARILY SHIFT SOUTH AFTER 6Z AS AFOREMENTIONED UPPER
WAVE PASSES. AS THIS OCCURS...WE STILL EXPECT ACCUMULATING SNOWS
TO MOVE BACK SOUTH INTO NORTHERN ONEIDA COUNTY AND WILL KEEP
CURRENT LAKE EFFECT ADVISORY IN PLACE. QUICK LOOK AT KBUF RADAR
SHOWS DEVELOPING STREAMERS SOUTH OF GEORGIAN BAY WHICH WITH TIME
WILL LIKELY MERGE WITH THE CURRENT LAKE ONTARIO BAND. AS THIS
OCCURS...WE EXPECT A RESURGENCE/STRENGTHENING OF THE BAND AS IT
GRADUALLY SHIFTS SOUTH AFTER MIDNIGHT. TOWARDS DAYBREAK...MODELS
INDICATE LOW /MID- LEVEL FLOW WILL BEGIN TO BACK AS NEXT UPPER
WAVE APPROACHES FROM SOUTHERN CANADA WHICH SHOULD CARRY HEAVIEST
ACTIVITY FURTHER NORTH ONCE AGAIN.
THE OTHER MAIN STORY IS WINDS AS ARCTIC AIRMASS CONTINUES TO
OVERSPREAD THE REGION. RECENT OBS HAVE INDICATED GUSTS AS HIGH AS
40 KTS IN SOME PLACES...WITH TEMPS RAPIDLY FALLING INTO THE SINGLE
DIGITS (HORNELL CURRENTLY REPORTING 0 DEGREES/WHILE PENN YAN
CURRENTLY SITTING AT 4). QUICK LOOK AT MSAS PRESSURE RISE IMAGES
SHOWS MAX PRESSURE RISE COUPLET EXITING OFF THE EAST THIS
HR...HOWEVER STRONG GUSTS WILL APPARENT WELL WEST IN A FAIRLY
TIGHT PRESSURE GRADIENT. AS A RESULT...EXPECT CONTINUED STRONG
GUSTY WINDS AND DANGEROUSLY LOW WIND CHILLS FOR THE FORESEEABLE
FUTURE.
650 PM UPDATE... VERY INTERESTING WX OCCURRING ACROSS PORTIONS OF
UPSTATE NY THIS HR...WITH MAIN ATTENTION FOCUSED ON FALLING TEMPS
BEHIND ARCTIC COLD FRONT/TROUGH THAT IS CURRENTLY WORKING THROUGH
THE AREA AND ONGOING LAKE EFFECT ACTIVITY EAST OF BOTH LAKES.
TEMPS RAPIDLY FALLING OUT WEST THIS HR WITH SINGLE DIGITS NOW
BEING REPORTED AS CLOSE AS THE WESTERN SOUTHERN TIER (0 DEGREES
CURRENTLY AT OLEAN...WHILE WELLSVILLE IS DOWN TO ONLY 3 DEGREES
THIS HR). UNFORTUNATELY THIS IS ONLY THE START AS TEMPS ACROSS ALL
OF CENTRAL NY AND NORTHEAST PA WILL QUICKLY FALL BELOW ZERO THIS
EVENING AS ARCTIC AIRMASS OVERSPREADS THE REGION. THIS COMBINED
WITH STEADY WEST WINDS OVERNIGHT INTO TOMORROW WILL CREATE VERY
DANGEROUS WIND CHILLS...HENCE THE ONGOING WIND CHILL WARNING WHICH
REMAINS IN EFFECT FOR ALL COUNTIES WITHIN THE CWA.
NOW TO THE LAKE EFFECT ACTIVITY...VERY IMPRESSIVE LAKE BAND OVER
THE BUFFALO METRO THIS EVENING WITH THE BUFFALO AIRPORT NOW
REPORTING VSBYS DOWN TO 1/16TH OF A MILE. TAKE THESE SNOWFALL
RATES AND COMBINE THEM WITH STRONG WINDS...AND BLIZZARD CONDITIONS
ARE OCCURRING UPSTREAM ACROSS WESTERN NY THIS HR. MEANWHILE CLOSER
TO OUR NECK OF THE WORDS...DISORGANIZED ACTIVITY STILL SEEN EAST
OF LAKE ONTARIO WITH THE HEAVIEST ACTIVITY STILL DISPLACED WELL
NORTH OF THE ONEIDA COUNTY LINE. BIG QUESTIONS STILL REMAIN THIS
EVENING ON WHETHER MAIN BAND WILL WORK ITS WAY SOUTH INTO NORTHERN
ONEIDA LATER TONIGHT. FOR NOW...CURRENT THINKING IS THAT BAND WILL
TEMPORARILY SHIFT SOUTH FOR A FEW HRS ON THE BACKSIDE OF MAIN
UPPER TROUGH NOW APPROACHING FROM THE CENTRAL GREAT LAKES. THAT
SAID HOWEVER...HEAVIEST ACTIVITY WILL LIKELY STILL REMAIN NORTH
AND THUS FEEL CURRENT LAKE EFFECT ADVISORY IS IN GOOD SHAPE AT
THIS TIME. WILL CONTINUE TO MONITOR.
AT 4 PM...TEMPS ACROSS THE AREA RANGED IN THE MID TO UPPER 20S. A
SECONDARY TROF WILL DROP THROUGH THE REGION LATER THIS EVENING
WITH TRUE ARCTIC AIR BEHIND THIS BOUNDARY. TEMPS OVERNIGHT WILL
RANGE FROM ZERO TO 10 BELOW DUE TO CAA ALONE AND NO RADIATIONAL
COOLING. THIS COMBINED WITH STRONG WESTERLY WINDS WILL RESULT IN
DANGEROUSLY COLD WIND CHILL VALUES. A WIND CHILL WARNING CONTINUES
FOR THE ENTIRE AREA LATER TONIGHT THROUGH TUESDAY.
LAKE EFFECT SNOW EAST OF LAKE ONTARIO IS CURRENTLY NORTH OF NRN
ONEIDA COUNTY AND SHOULD REMAIN THERE UNTIL THIS SECONDARY TROF
DROPS THROUGH. LATER THIS EVENING THROUGH MID MORNING TUE THE FLOW
SHOULD BECOME FAVORABLE FOR LAKE EFFECT SNOW. FOR THIS REASON
ISSUED A LAKE EFFECT SNOW ADV. LOOKING AT THE MODEL SOUNDING
PROFILES SHOWS A FAIR AMOUNT OF SHEAR WITHIN THE UNSTABLE LAYER.
LOOKING AT THE WIND DIRECTION IN THE LOWER PART OF THE UNSTABLE
LAYER WOULD KEEP THE BAND NORTH OF ONEIDA COUNTY BUT THE TOP PART
OF THE MIXED LAYER SHOWS WESTERLY FLOW IMPLY A NRN ONEIDA COUNTY
BAND. IT WILL BE INTERESTING TO SEE HOW THIS PLAYS OUT, MAYBE A
BROAD BUT LESS INTENSE LAKE BAND WILL DEVELOP.
DEEP CYCLONIC FLOW WILL KEEP PLENTY OF CLOUDS ACROSS THE AREA
THROUGH TUESDAY ALONG WITH SCATTERED FLURRIES. MAX TEMPS ON
TUESDAY WILL REMAIN IN THE SINGLE DIGITS AS T85 RANGE FROM -23/-26C.
STRONG GUSTY WESTERLY WINDS WILL KEEP EXTREME WIND CHILLS OVER
THE AREA THROUGH LATE AFTERNOON.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY NIGHT/...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BROAD H5 TROF REMAINS
OVER THE REGION THROUGH THIS PERIOD WITH ARCTIC AIRMASS ACROSS THE
NORTHEAST. LAKE EFFECT SNOW WILL CONTINUE EAST OF LAKE ONTARIO
THROUGH THIS PERIOD, OCCASIONALLY DROPPING INTO NRN ONEIDA COUNTY,
ESPECIALLY TUESDAY NIGHT.
LOWS TUE NIGHT WILL BE AREA ZERO WITH HIGHS ON WED IN THE TEENS.
BY THURSDAY, SFC HIGH PRES IN THE VCNTY ALONG WITH SOME AIRMASS
MODIFICATION WILL RESULT IN MAX TEMPS IN THE MID TO UPPER 20S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
130 AM UPDATE...
LITTLE CHANGE. FOLLOWED WPC GUIDANCE. ACTIVE BUT WARMER PATTERN.
BOTH EURO AND GFS BRING US RAIN DURING THE DAY SATURDAY. UPPED
POPS TO LIKELY. AFTER THAT A BRIEF RIDGE WITH LITTLE PRECIP. FOR
THE NEXT SYSTEM MODELS DIFFER BY 12 HOURS ON ANOTHER PERIOD OF
RAIN. GFS SUN NGT AND EURO MONDAY. WENT WITH THE EURO AND NO
PRECIP SUN NGT AND CHC POPS MON. MAYBE A COOL DOWN TO NORMAL OR
SLIGHTLY BELOW THAT MIDWEEK NEXT WEEK.
230 PM EST UPDATE...
MADE MINOR ADJUSTMENTS TO THE PREVIOUS FORECAST. A SURFACE RIDGE
WILL SLOWLY SHIFT EAST ON FRIDAY AND DRIFT OFF TO SEA AS ANOTHER
UPPER LEVEL LOW STARTS TO PUSH EAST TOWARDS THE REGION. APPEARS TO
BE ANOTHER WET FORECAST AND KEPT CHANCES FOR EITHER RAIN OR SNOW
THROUGH THE EXTENDED. AS THE UPPER LOW MOVES CLOSER TO THE
NORTHEAST THE CHANCES FOR PRECIP INCREASES AND THE NEXT BEST
CHANCE FOR PRECIP WILL BE SATURDAY. MUCH WARMER WEATHER IS
EXPECTED THIS WEEKEND SO RAIN LOOKS TO BE THE DOMINATE TYPE.
ANOTHER SHORTWAVE IS EXPECTED TO SWEEP ACROSS THE REGION ON
SUNDAY/SUNDAY NIGHT...BUT MODELS HAVE DISCREPANCIES ON THE TIMING
THIS LOW SO KEPT POPS LOW.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
1230 AM UPDATE...
WITH A WESTERLY LOW LEVEL FLOW LAKE EFFECT WILL STAY WEST AND
NORTH OF REGION FOR THE MOST PART. AT RME BAND HAS DROPPED DOWN
EARLY THIS MORNING BUT SHOULD LIFT BACK NORTH BY 12Z. AT BGM WITH
THE OPENNESS ON TOP OF A HILL BLOWING SNOW COULD REDUCE THE
VISIBILITY AT TIMES TO MVFR AND MAYBE IFR BRIEFLY.
THE MAIN STORY WILL CONTINUE TO BE THE STG W WINDS OF 10 TO 20
KTS...WITH GUSTS OF 25-35 KT ALL SITES INTO TONIGHT.
OUTLOOK...
TUE NGT THROUGH WED NGT...OCNL RESTRICTIONS PSBL IN SHSN/FLRYS
FOR THE CENTRAL NY TERMINALS...WITH VFR AT KAVP.
THU...VFR.
THU NGT THROUGH FRI NGT...RESTRICTIONS POSSIBLE IN LIGHT
SNOW...OR A RAIN/SNOW MIX.
SAT...MVFR IN RAIN.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND CHILL WARNING UNTIL 7 PM EST THIS EVENING FOR PAZ038>040-
043-044-047-048-072.
NY...WIND CHILL WARNING UNTIL 7 PM EST THIS EVENING FOR NYZ009-
015>018-022>025-036-037-044>046-055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ009.
&&
$$
SYNOPSIS...RRM
NEAR TERM...CMG/PVN/RRM
SHORT TERM...RRM
LONG TERM...KAH/TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1149 PM EST MON JAN 6 2014
.SYNOPSIS...
AN ARCTIC AIRMASS WILL RESIDE OVER THE REGION THROUGH WEDNESDAY
NIGHT. DANGEROUSLY COLD WIND CHILLS ARE LIKELY TONIGHT THROUGH
TUESDAY. THE CORE OF THE ARCTIC AIR MASS WILL MOVE NORTHEAST OF
THE REGION BY THURSDAY WITH MODERATING TEMPERATURES.
&&
.NEAR TERM /THROUGH TUESDAY/...
1145 PM UPDATE...
QUICK UPDATE TO LWR TEMPS SOME MORE AS HORNELL NY IS NOW DOWN TO
-2F AS OF 04Z. HV OPTED TO COMBINE CURRENT FCST TEMPS WITH LATEST
RAP AS RAP IS DROPPING THEM OFF CLOSER TO REALITY. THUS THINK THAT
OVRNGT MINS, ON AVERAGE, WL BE ABOUT 1-3 DEGREES CLDR THAN FCST.
IN ADDITION, HV ADJUSTED POPS ACRS NRN ONEIDA CNTY TO RMV POPS FOR
THE TIME BEING. EXPECT SNOW SHOWERS WILL DROP INTO NRN ONEIDA CNTY
AFT 07Z AS UL WV PASSES.
1005 PM UPDATE...
WITHIN THE PAST TWO HOURS...A NICE SQUALL DEVELOPED ACROSS THE
CENTRAL SOUTHERN TIER THAT LED TO A PERIOD OF WHITEOUT CONDITIONS
ACROSS THE GREATER BINGHAMTON AREA AND POINTS EAST. THIS
ACTIVITY...STILL READILY APPARENT ON RADAR...IS RAPIDLY MOVING
THROUGH THE WESTERN CATSKILLS ATTM. LOCAL SCANNER BROADCASTS
INDICATE NUMEROUS ACCIDENTS WITHIN THE BINGHAMTON AREA AS ROADS
QUICKLY ICED UP...AND REPORTS OF ALMOST 3" HAVE BEEN RECEIVED
ACROSS BROOME COUNTY.
SO WITH THIS NEARLY GONE...ATTENTION SHIFTS BACK TO ONGOING LAKE
EFFECT ACTIVITY EAST OF LAKE ONTARIO. OVER THE PAST FEW
HRS...SOUTHWEST FLOW HAS CARRIED THE BAND FURTHER AND FURTHER
NORTH AS CYCLONIC LOW-LEVEL FLOW IN ADVANCE OF MAIN MID-LEVEL
VORTEX DESCENDS UPON THE REGION. THAT SAID...MODELS STILL INDICATE
BAND WILL TEMPORARILY SHIFT SOUTH AFTER 6Z AS AFOREMENTIONED UPPER
WAVE PASSES. AS THIS OCCURS...WE STILL EXPECT ACCUMULATING SNOWS
TO MOVE BACK SOUTH INTO NORTHERN ONEIDA COUNTY AND WILL KEEP
CURRENT LAKE EFFECT ADVISORY IN PLACE. QUICK LOOK AT KBUF RADAR
SHOWS DEVELOPING STREAMERS SOUTH OF GEORGIAN BAY WHICH WITH TIME
WILL LIKELY MERGE WITH THE CURRENT LAKE ONTARIO BAND. AS THIS
OCCURS...WE EXPECT A RESURGENCE/STRENGTHENING OF THE BAND AS IT
GRADUALLY SHIFTS SOUTH AFTER MIDNIGHT. TOWARDS DAYBREAK...MODELS
INDICATE LOW /MID- LEVEL FLOW WILL BEGIN TO BACK AS NEXT UPPER
WAVE APPROACHES FROM SOUTHERN CANADA WHICH SHOULD CARRY HEAVIEST
ACTIVITY FURTHER NORTH ONCE AGAIN.
THE OTHER MAIN STORY IS WINDS AS ARCTIC AIRMASS CONTINUES TO
OVERSPREAD THE REGION. RECENT OBS HAVE INDICATED GUSTS AS HIGH AS
40 KTS IN SOME PLACES...WITH TEMPS RAPIDLY FALLING INTO THE SINGLE
DIGITS (HORNELL CURRENTLY REPORTING 0 DEGREES/WHILE PENN YAN
CURRENTLY SITTING AT 4). QUICK LOOK AT MSAS PRESSURE RISE IMAGES
SHOWS MAX PRESSURE RISE COUPLET EXITING OFF THE EAST THIS
HR...HOWEVER STRONG GUSTS WILL APPARENT WELL WEST IN A FAIRLY
TIGHT PRESSURE GRADIENT. AS A RESULT...EXPECT CONTINUED STRONG
GUSTY WINDS AND DANGEROUSLY LOW WIND CHILLS FOR THE FORESEEABLE
FUTURE.
650 PM UPDATE... VERY INTERESTING WX OCCURRING ACROSS PORTIONS OF
UPSTATE NY THIS HR...WITH MAIN ATTENTION FOCUSED ON FALLING TEMPS
BEHIND ARCTIC COLD FRONT/TROUGH THAT IS CURRENTLY WORKING THROUGH
THE AREA AND ONGOING LAKE EFFECT ACTIVITY EAST OF BOTH LAKES.
TEMPS RAPIDLY FALLING OUT WEST THIS HR WITH SINGLE DIGITS NOW
BEING REPORTED AS CLOSE AS THE WESTERN SOUTHERN TIER (0 DEGREES
CURRENTLY AT OLEAN...WHILE WELLSVILLE IS DOWN TO ONLY 3 DEGREES
THIS HR). UNFORTUNATELY THIS IS ONLY THE START AS TEMPS ACROSS ALL
OF CENTRAL NY AND NORTHEAST PA WILL QUICKLY FALL BELOW ZERO THIS
EVENING AS ARCTIC AIRMASS OVERSPREADS THE REGION. THIS COMBINED
WITH STEADY WEST WINDS OVERNIGHT INTO TOMORROW WILL CREATE VERY
DANGEROUS WIND CHILLS...HENCE THE ONGOING WIND CHILL WARNING WHICH
REMAINS IN EFFECT FOR ALL COUNTIES WITHIN THE CWA.
NOW TO THE LAKE EFFECT ACTIVITY...VERY IMPRESSIVE LAKE BAND OVER
THE BUFFALO METRO THIS EVENING WITH THE BUFFALO AIRPORT NOW
REPORTING VSBYS DOWN TO 1/16TH OF A MILE. TAKE THESE SNOWFALL
RATES AND COMBINE THEM WITH STRONG WINDS...AND BLIZZARD CONDITIONS
ARE OCCURRING UPSTREAM ACROSS WESTERN NY THIS HR. MEANWHILE CLOSER
TO OUR NECK OF THE WORDS...DISORGANIZED ACTIVITY STILL SEEN EAST
OF LAKE ONTARIO WITH THE HEAVIEST ACTIVITY STILL DISPLACED WELL
NORTH OF THE ONEIDA COUNTY LINE. BIG QUESTIONS STILL REMAIN THIS
EVENING ON WHETHER MAIN BAND WILL WORK ITS WAY SOUTH INTO NORTHERN
ONEIDA LATER TONIGHT. FOR NOW...CURRENT THINKING IS THAT BAND WILL
TEMPORARILY SHIFT SOUTH FOR A FEW HRS ON THE BACKSIDE OF MAIN
UPPER TROUGH NOW APPROACHING FROM THE CENTRAL GREAT LAKES. THAT
SAID HOWEVER...HEAVIEST ACTIVITY WILL LIKELY STILL REMAIN NORTH
AND THUS FEEL CURRENT LAKE EFFECT ADVISORY IS IN GOOD SHAPE AT
THIS TIME. WILL CONTINUE TO MONITOR.
AT 4 PM...TEMPS ACROSS THE AREA RANGED IN THE MID TO UPPER 20S. A
SECONDARY TROF WILL DROP THROUGH THE REGION LATER THIS EVENING
WITH TRUE ARCTIC AIR BEHIND THIS BOUNDARY. TEMPS OVERNIGHT WILL
RANGE FROM ZERO TO 10 BELOW DUE TO CAA ALONE AND NO RADIATIONAL
COOLING. THIS COMBINED WITH STRONG WESTERLY WINDS WILL RESULT IN
DANGEROUSLY COLD WIND CHILL VALUES. A WIND CHILL WARNING CONTINUES
FOR THE ENTIRE AREA LATER TONIGHT THROUGH TUESDAY.
LAKE EFFECT SNOW EAST OF LAKE ONTARIO IS CURRENTLY NORTH OF NRN
ONEIDA COUNTY AND SHOULD REMAIN THERE UNTIL THIS SECONDARY TROF
DROPS THROUGH. LATER THIS EVENING THROUGH MID MORNING TUE THE FLOW
SHOULD BECOME FAVORABLE FOR LAKE EFFECT SNOW. FOR THIS REASON
ISSUED A LAKE EFFECT SNOW ADV. LOOKING AT THE MODEL SOUNDING
PROFILES SHOWS A FAIR AMOUNT OF SHEAR WITHIN THE UNSTABLE LAYER.
LOOKING AT THE WIND DIRECTION IN THE LOWER PART OF THE UNSTABLE
LAYER WOULD KEEP THE BAND NORTH OF ONEIDA COUNTY BUT THE TOP PART
OF THE MIXED LAYER SHOWS WESTERLY FLOW IMPLY A NRN ONEIDA COUNTY
BAND. IT WILL BE INTERESTING TO SEE HOW THIS PLAYS OUT, MAYBE A
BROAD BUT LESS INTENSE LAKE BAND WILL DEVELOP.
DEEP CYCLONIC FLOW WILL KEEP PLENTY OF CLOUDS ACROSS THE AREA
THROUGH TUESDAY ALONG WITH SCATTERED FLURRIES. MAX TEMPS ON
TUESDAY WILL REMAIN IN THE SINGLE DIGITS AS T85 RANGE FROM -23/-26C.
STRONG GUSTY WESTERLY WINDS WILL KEEP EXTREME WIND CHILLS OVER
THE AREA THROUGH LATE AFTERNOON.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BROAD H5 TROF REMAINS
OVER THE REGION THROUGH THIS PERIOD WITH ARCTIC AIRMASS ACROSS THE
NORTHEAST. LAKE EFFECT SNOW WILL CONTINUE EAST OF LAKE ONTARIO
THROUGH THIS PERIOD, OCCASIONALLY DROPPING INTO NRN ONEIDA COUNTY,
ESPECIALLY TUESDAY NIGHT.
LOWS TUE NIGHT WILL BE AREA ZERO WITH HIGHS ON WED IN THE TEENS.
BY THURSDAY, SFC HIGH PRES IN THE VCNTY ALONG WITH SOME AIRMASS
MODIFICATION WILL RESULT IN MAX TEMPS IN THE MID TO UPPER 20S.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
230 PM EST UPDATE...
MADE MINOR ADJUSTMENTS TO THE PREVIOUS FORECAST. A SURFACE RIDGE
WILL SLOWLY SHIFT EAST ON FRIDAY AND DRIFT OFF TO SEA AS ANOTHER
UPPER LEVEL LOW STARTS TO PUSH EAST TOWARDS THE REGION. APPEARS TO
BE ANOTHER WET FORECAST AND KEPT CHANCES FOR EITHER RAIN OR SNOW
THROUGH THE EXTENDED. AS THE UPPER LOW MOVES CLOSER TO THE
NORTHEAST THE CHANCES FOR PRECIP INCREASES AND THE NEXT BEST
CHANCE FOR PRECIP WILL BE SATURDAY. MUCH WARMER WEATHER IS
EXPECTED THIS WEEKEND SO RAIN LOOKS TO BE THE DOMINATE TYPE.
ANOTHER SHORTWAVE IS EXPECTED TO SWEEP ACROSS THE REGION ON
SUNDAY/SUNDAY NIGHT...BUT MODELS HAVE DISCREPANCIES ON THE TIMING
THIS LOW SO KEPT POPS LOW.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
620 PM MON UPDATE... THIS TAF PD WILL FEATURE VFR CONDS...AS FOR
THE MOST PART...SIG LES BANDS OFF BOTH LAKES ERIE AND ONT STAY
WELL REMOVED FROM OUR TERMINAL SITES.
IT`S PSBL THAT THE LK ONT BAND COULD VERY BRIEFLY DROP SWD AFTER
06Z...AND APPROACH KRME. IF THIS WERE TO HAPPEN...IFR CONDS WOULD
PROBABLY OCCUR. FOR NOW...WE`VE INTRODUCED THIS PSBLTY FOR JUST A
FEW HRS...PRIOR TO 12Z TUE. WE ALSO COULD WELL SEE TRANSITORY
-SHSN/FLRYS ACRS CNY JUST ABT ANYTIME THIS PD...EACH ONE PERHAPS
BRINGING BRIEF RESTRICTIVE CONDS. HOWEVER...GIVEN THEIR
BREVITY...AND ALSO LACK OF PREFERENCE FOR ANY ONE SPECIFIC TIME
FRAME...WE`VE ELECTED TO NOT INCLUDE ANY TEMPO GROUPS FOR SUCH ATTM.
THE MAIN STORY SHOULD BE THE STG WRLY WINDS...WITH GUSTS OF 25-35
KT INDICATED AREA-WIDE.
OUTLOOK...
TUE NGT THROUGH WED...OCNL RESTRICTIONS PSBL IN SHSN/FLRYS FOR THE
CENTRAL NY TERMINALS...WITH MOSTLY VFR AT KAVP.
THU THROUGH SAT...RESTRICTIONS POSSIBLE IN LIGHT SNOW...OR A
RAIN/SNOW MIX.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WIND CHILL WARNING UNTIL 7 PM EST TUESDAY FOR PAZ038>040-043-
044-047-048-072.
NY...WIND CHILL WARNING UNTIL 7 PM EST TUESDAY FOR NYZ009-015>018-
022>025-036-037-044>046-055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 10 AM EST TUESDAY FOR NYZ009.
&&
$$
SYNOPSIS...RRM
NEAR TERM...CMG/PVN/RRM
SHORT TERM...RRM
LONG TERM...KAH
AVIATION...KAH/MLJ
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
335 AM EST TUE JAN 7 2014
.SYNOPSIS...
ARCTIC HIGH PRESSURE WILL BUILD OVER THE AREA TODAY INTO TONIGHT.
THE HIGH WILL SHIFT TO THE NORTH WEDNESDAY NIGHT. A TROUGH OF LOW
PRESSURE WILL DEVELOP ALONG THE SOUTHEAST COAST THURSDAY AND
LINGER INTO FRIDAY...THEN DISSIPATE FRIDAY NIGHT. A SERIES OF
FRONTS WILL AFFECT THE AREA THIS WEEKEND INTO EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 330 AM TUE...STRONG CAA CONTINUING EARLY THIS MORNING AS
ARCTIC AIR MASS SPILLING OVER THE APPALACHIANS AND INTO E NC.
CURRENT TEMPS IN THE UPPER TEENS INLAND TO LOW/MID COAST. BNDRY
LAYER REMAINS MIXED AND NW WINDS CONTINUE AOA 10 KT OCNL GUSTING
TO 20 KT. THESE CONDITIONS ARE PRODUCING WIND CHILLS IN THE SINGLE
DIGITS IN THE COASTAL PLAIN TO LOW TEENS COAST. TEMPS WILL CONTINUE TO
TUMBLE INTO THE MIDDLE TEENS BY DAYBREAK WHEN WE EXPECT THE LOWEST
WIND CHILLS TO OCCUR...GENERALLY 0 TO 5 BELOW. WIND CHILL
HEADLINES LOOK TO BE ON TRACK WITH RISING VALUES ABOVE CRITERIA BY
MID MORNING. RECORD BREAKING COLD MINS THIS MORNING AND RECORD
LOW MAX TEMPS THIS AFTERNOON SHOULD EASILY BE ATTAINED AS
THICKNESS VALS AT 18Z ONLY EXPECTED IN THE 1240-1245 M
RANGE...WHICH TRANSLATES TO HIGHS ONLY IN THE MID 20S FOR MOST
AREAS IN THE NORTHERN/WESTERN FA. GEFS MEAN 850MB TEMPS AND
M-CLIMATE ANOMOLIES INDICATE THESE TEMPS OCCURRING JUST OUTSIDE
THE 30 YEAR CFSR PERIOD...ANOTHER INDICATOR OR RECORD BREAKING
POTENTIAL.
&&
.SHORT TERM /TONIGHT/...
AS OF 330 AM TUE...ARCTIC HIGH PRES WILL MIGRATE EAST AND BE
CENTERED OVER THE AREA TONIGHT...AND WITH CALM WINDS AND CLEAR
SKIES ALONG WITH EXTREMELY DRY AIRMASS...EXCELLENT RADIATIONAL
COOLING CONDITIONS EXPECTED. RECORDS SHOULD BE ATTAINED FOR AREAS
ONCE AGAIN AS MOST LOCALES AWAY FROM THE COAST DROP WELL INTO THE
TEENS. WIND CHILLS WILL NOT BE A FACTOR AS CALM CONDITIONS ARE
EXPECTED.
&&
.LONG TERM /WEDNESDAY THROUGH MONDAY/...
AS OF 245 AM TUESDAY...THIS PERIOD WILL SEE A TRANSITION FROM UPPER
TROUGHING TO RIDGING WITH A COLD REGIME EVENTUALLY TRANSITIONING
TO ONE FEATURING ABOVE NORMAL TEMPERATURES BY THE WEEKEND.
THE CORE OF THE ARCTIC AIR MASS WILL BEGIN TO MODERATE AND RETREAT
TO THE NORTH WEDNESDAY AS THE CENTER OF HIGH PRESSURE SETTLES OVER
NORTH CAROLINA. HIGHS WILL RECOVER TO THE UPPER 30S/LOWER 40S
WHICH IS STILL WELL BELOW NORMAL. WEDNESDAY NIGHT GOOD RADIATIONAL
COOLING IS EXPECTED WITH MOSTLY CLEAR SKIES/LIGHT WINDS WHICH WILL
LEAD TO COLD OVERNIGHT LOWS IN THE LOWER TO MIDDLE 20S. THE HIGH
WILL MOVE OFF OF THE COAST THURSDAY WITH A WEAK TROUGH OF LOW
PRESSURE DEVELOPING OFFSHORE PRODUCING AN EASTERLY FLOW ACROSS THE
AREA. WARM ADVECTION WILL PRODUCE WEAK LIFT WHICH WILL RESULT IN
THE DEVELOPMENT OF LOW CLOUDS ACROSS THE AREA IN THE AFTERNOON.
THERE COULD A FEW LIGHT SHOWERS BUT THE MODELS ARE ALL OVER THE
PLACE WITH REGARDS TO THE QPF FORECAST. THINK REGION WITH BEST
THREAT FOR THESE SHOWERS WILL BE FROM THE SOUTHERN COASTAL PLAIN
TO THE CRYSTAL COAST WHERE A SLIGHT CHANCE POP (20%) WILL BE
CARRIED. THE EASTERLY (MARITIME FLOW) WILL BRING MILDER
TEMPERATURES TO THE REGION WITH HIGHS IN THE UPPER 40S TO LOWER 50S.
THE PERIOD FROM FRIDAY INTO EARLY NEXT WEEK LOOKS TO BE UNSETTLED
WITH LACK OF MODEL RUN TO RUN CONSISTENCY AND SPREAD IN SOLUTIONS
BETWEEN THE VARIOUS MODELS LEADING TO A BELOW NORMAL CONFIDENCE
FACTOR IN THE PRECIPITATION FORECAST. MUCH HIGHER CONFIDENCE IN
THE TEMPERATURE FORECAST WITH ABOVE NORMAL WARMTH EXPECTED
SATURDAY TO MONDAY WITH HIGHS IN THE 60S AND POSSIBLY A FEW 70S
DEPENDING ON HOW THE AMOUNT OF CLOUDS AND PRECIPITATION. FOR NOW
WILL CONTINUE WITH PREVIOUS FORECAST OF CARRYING LOW CHANCE POPS
THROUGH THE PERIOD UNTIL THE PRECIPITATION PATTERN BECOMES BETTER
DEFINED WITH SATURDAY LOOKING TO BE WETTEST DAY AT THIS POINT.
&&
.AVIATION /07Z TUESDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 2 AM TUE...VFR SKC THROUGH THE TAF PD. GUSTY NW WINDS THIS
MORNING WILL RELAX THROUGH THE DAY AS GRADIENT DECREASES. CALM
CONDITIONS EXPECTED BY THIS EVENING THROUGH THE OVERNIGHT.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 245 AM TUESDAY...DRY WEATHER WITH PREVAILING VFR CONDITIONS
ARE EXPECTED INTO THURSDAY. LATE THURSDAY EXPECTING INCREASING
CLOUDS THU AHEAD OF A WEAK COASTAL TROF AND SHOULD SEE A SOME
SHOWERS WITH SUB-VFR CONDITIONS BEGINNING THU NIGHT AND ON INTO
THE WEEKEND AS AN INCREASINGLY MOIST AIRMASS LEADS TO AN UNSETTLED
WEATHER PATTERN OVER THE AREA.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 330 AM TUE...LATEST OBS SHOW WNW WINDS AROUND 25 KT WITH GUSTS
TO 35 KT...MOST NOTEABLY OVER THE OUTER WATERS. SEAS RUNNING 5 TO
9 FEET WITH HIGHEST SEAS OVER THE OUTER WATERS. HAVE CUT BACK
ENDING TIME OF GALES TO 12Z...AS MODELLED SOUNDINGS OVER THE
WATERS AND HRRR BOTH INDICATING A RELAXING GRADIENT BY THEN. GALES
WILL HAVE TO BE REPLACED BY SCA BY THEN. SHOULD SEE A RAPID DEC IN
WINDS THROUGH THE DAY AS ARCTIC HIGH PRES APPROACHES AND GRADIENT
RELAXES. SEAS SHOULD SUBSIDE BELOW 6 FEET BY EARLY THIS EVENING
AND HAVE USED A BLEND OF WW4 AND LOCAL NWPS FOR SEAS FCST.
LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 245 AM TUESDAY...NORTHERLY WINDS WILL BECOME LIGHT
WEDNESDAY DIMINISHING FROM 15 KT EARLY TO LESS THAN 10 KT. AS A
WEAK TROUGH OF LOW PRESSURE DEVELOPS OFFSHORE THURSDAY WINDS WILL
BECOME NORTHEAST AND INCREASE TO 10 TO 15 KT BECOMING EAST TO
SOUTHEAST FRIDAY AND SOUTHEAST SATURDAY WHILE INCREASING TO 15 TO
20 KT. WAVE WATCH IS BUILDING SEAS TO 6+ FT SATURDAY SO MARINERS
SHOULD PLAN FOR SMALL CRAFT ADVISORY CONDITIONS FOR THE WEEKEND IF
THIS TREND CONTINUES IN THE MARINE GUIDANCE.
&&
.CLIMATE...
RECORD MIN TEMPS FOR JANUARY 7TH:
NEW BERN 23 2010
CAPE HATTERAS 27 1984
WILLIAMSTON 18 1995
KINSTON 15 1969
GREENVILLE 10 1924
BAYBORO 20 1988
MOREHEAD CITY 23 2010
OCRACOKE 28 1999
MANTEO 23 1988
WASHINGTON 25 2010
RECORD LOW MAX TEMPS FOR JANUARY 7TH:
NEW BERN 34 1988
CAPE HATTERAS 38 1973
WILLIAMSTON 29 1988
KINSTON 26 1942
GREENVILLE 27 1924
BAYBORO 30 1988
MOREHEAD CITY 33 1988
OCRACOKE 40 2010
MANTEO 33 1988
WASHINGTON 43 2010
RECORD MIN TEMPS FOR JANUARY 8TH:
NEW BERN 18 1970
CAPE HATTERAS 20 1970
WILLIAMSTON 16 1970
KINSTON 16 1968
GREENVILLE 13 1986
BAYBORO 19 1986
MOREHEAD CITY 16 1968
OCRACOKE 23 1968
MANTEO 20 1986
WASHINGTON 21 1903
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...WIND CHILL ADVISORY UNTIL 10 AM EST THIS MORNING FOR NCZ029-
044>047-079>081-090>095-098-103-104.
MARINE...GALE WARNING UNTIL 7 AM EST THIS MORNING FOR AMZ130-135-150-
152-154-156-158.
&&
$$
SYNOPSIS...TL
NEAR TERM...TL
SHORT TERM...TL
LONG TERM...BTC/JME
AVIATION...JME/TL
MARINE...JME/TL
CLIMATE...
AREA FORECAST DISCUSSION
NWS RALEIGH NC
250 AM EST TUE JAN 7 2014
.SYNOPSIS...ANOMALOUSLY COLD ARCTIC HIGH PRESSURE WILL SETTLE OVER
THE CAROLINAS AND VIRGINIA THROUGH WEDNESDAY. A GRADUAL WARMING
TREND WILL BEGIN ON THURSDAY AS HIGH PRESSURE MOVES OFFSHORE AND A
SOUTHERLY RETURN FLOW DEVELOPS ACROSS THE REGION.
&&
.NEAR TERM /TODAY THROUGH WEDNESDAY/...
AS OF 240 AM TUESDAY...
...POSSIBLY THE COLDEST DAY OF 2014...
THE WIND CHILL ADVISORY WILL REMAIN IN EFFECT FOR ALL OF CENTRAL NC
THROUGH NOON TODAY. ADVISORY CRITERIA HAS ALREADY BEEN MET (WIND
CHILL VALUES OF 0 TO -10F AS OF 07Z) IN MOST AREAS WEST OF HWY
1...WITH THE COASTAL PLAIN /I-95 CORRIDOR/ EXPECTED TO
MEET ADVISORY CRITERIA BY SUNRISE.
TODAY/TONIGHT: THE POLAR VORTEX (A COLD/EXPANSIVE UPPER LEVEL LOW)
CENTERED IN VICINITY OF JAMES BAY THIS MORNING WILL LIFT NORTHEAST
INTO THE CANADIAN MARITIMES THIS AFTERNOON/TONIGHT (TO A MORE
TYPICAL LOCATION NEAR BAFFIN ISLAND)...RESULTING IN SYNOPTIC
SUBSIDENCE /HEIGHT RISES ALOFT/ ACROSS THE CAROLINAS. THE STRONGEST
SYNOPTIC SUBSIDENCE AND HEIGHT RISES WILL OCCUR THIS MORNING...
REINFORCING SURFACE PRESSURE RISES ACROSS THE REGION AND PROLONGING
THE ADVECTION OF AN ANOMALOUSLY COLD (`TO BUILD A FIRE`) ARCTIC
AIRMASS INTO CENTRAL NC. FORECAST SOUNDINGS INDICATE A WELL MIXED
BOUNDARY LAYER EXTENDING UP TO 925-900 MB (2500-3500 FT AGL)...AND
THE DRY ADIABATIC METHOD WOULD SUGGEST HIGHS RANGING FROM THE UPPER
TEENS /NEAR 20F/ IN THE FAR NW PIEDMONT TO THE LOWER/MID 20S
ELSEWHERE (WARMEST SOUTH/SE). THOUGH THE ARCTIC AIRMASS WILL QUICKLY
BEGIN TO MODIFY TONIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS
WOULD SUGGEST LOWS IN THE LOWER/MID TEENS WED MORNING.
INTERESTINGLY...THE LATEST RAP FCST SOUNDINGS SHOW A POTENTIAL FOR
VERY SHALLOW INSTABILITY TO DEVELOP UNDER THE SUBSIDENCE INVERSION
THIS MORNING ACROSS PORTIONS OF THE SANDHILLS/SE COASTAL PLAIN AND
THIS AFTERNOON IN THE PIEDMONT BY VIRTUE OF STEEP LAPSE RATES
ASSOC/W SUCH A COLD LOW-LEVEL AIRMASS (-12 TO -15C AT 900 MB)...
THOUGH IT IS DIFFICULT TO BELIEVE THAT SUFFICIENT LOW-LEVEL MOISTURE
WILL BE IN PLACE FOR VERY SHALLOW CU/TCU TO DEVELOP GIVEN SUCH A DRY
AIRMASS (PER 00Z GSO RAOB) AND THAT IT IS TYPICALLY DIFFICULT FOR
ANY UPSTREAM MOISTURE TO ADVECT EAST OF THE SOUTHERN APPALACHIANS IN
THIS TYPE OF REGIME. GIVEN THAT TEMPS AT THE TOP OF THE MIXED LAYER
WILL FALL WITHIN THE ICE NUCLEATION ZONE (I.E. -12 TO -15C)...IF LOW-
LEVEL MOISTURE IS SUFFICIENT IT WOULD AT LEAST BE POSSIBLE FOR
SHALLOW CU/TCU TO DEVELOP AND PERHAPS PRODUCE A FEW FLURRIES. WITH
THE ABOVE IN MIND...FEEL THAT THE AFOREMENTIONED SCENARIO IS TOO
UNLIKELY TO WARRANT MENTION IN THE FCST AT THIS TIME AND WILL
MAINTAIN A DRY FORECAST THROUGH TONIGHT.
WEDNESDAY: HIGH PRESSURE CENTERED OVER THE REGION WED MORNING WILL
GRADUALLY SHIFT OFFSHORE WED NIGHT AS SHORTWAVE ENERGY IN ZONAL FLOW
ALOFT APPROACHES THE SOUTHERN APPALACHIANS FROM THE WEST. WITH DRY
HIGH PRESSURE OVER THE REGION DURING THE DAY...EXPECT CONTINUED
COLD/CLEAR CONDITIONS WITH HIGHS IN THE UPPER 30S (NORTH) TO LOWER
40S (SOUTH). -VINCENT
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 221 AM TUESDAY...
EVEN WITH THE AFOREMENTIONED BITTERLY COLD AIR MASS PULLING OUT
RAPIDLY TO THE NE AND RAPIDLY RISING HEIGHTS ALOFT... THE LINGERING
SURFACE HIGH PRESSURE OVER OUR REGION SHOULD BRING ANOTHER COLD
NIGHT FOR WEDNESDAY NIGHT. MOSTLY CLEAR SKIES WITH LOWS IN THE LOWER
TO MID 20S EXPECTED WITH SOME UPPER TEENS IN THE NORMALLY COLDER
SPOTS.
MODERATION WILL CONTINUE ON THURSDAY AS THE MAIN SURFACE HIGH
PRESSURE BECOMES ESTABLISHED OVER NEW ENGLAND BUT EXTENDING INTO
NC/SC FROM THE NORTH BEFORE SHIFTING SLOWLY OFFSHORE BY FRIDAY
MORNING. AS THE HIGH PRESSURE SHIFTS EASTWARD... WAA WILL COMMENCE
ALOFT AND THIS WILL OVERRUN THE COLD STABLE NEAR SURFACE LAYER BY
LATE THURSDAY AND THURSDAY NIGHT. SOME MODELS AND ENSEMBLE MEMBERS
SPIT OUT A FEW HUNDREDTHS OF PRECIPITATION BETWEEN 06Z-12Z FRIDAY...
MAINLY OVER THE PIEDMONT. P-TYPE WITH WARMING ALOFT WOULD BE
LIQUID... BUT CONCERNS REMAIN WITH THE VERY COLD DRY SURFACE LAYER
OF SOME LIGHT GLAZE OR ICING IN THE PIEDMONT (ESPECIALLY IN THE
TRIAD REGION) LATE THURSDAY NIGHT (SIMILAR TO THE EVENT LAST
SUNDAY). THERE APPEARS TO BE SIGNIFICANT EVAPORATIONAL COOLING
POTENTIAL THURSDAY NIGHT THAT IF ENOUGH LIGHT RAIN FALLS... TEMPS
WOULD COOL RAPIDLY TO NEAR 30 IN THE TRIAD. CURRENT SURFACE WET BULB
FORECASTS INDICATE THIS POTENTIAL... WITH LESSER CHANCES OF ANY
ICING AT RDU... TO NIL IN THE FAY/GSB/RWI AREAS OF THE WARMER
SANDHILLS AND COASTAL PLAIN. CURRENT POP IS 50 OR LESS... OR LESS
THAN LIKELY... WITH QPF OF A FEW HUNDREDTHS IF IT MATERIALIZES.
FOR NOW... WE WILL ADD MENTION OF LIGHT RAIN POSSIBLY MIXED WITH
FREEZING RAIN EARLY (IN THE TRIAD ZONES ONLY)... WITH A CHANCE OF
LIGHT RAIN ELSEWHERE. LOWS 30-38 NW TO SE. IN ADDITION... MOST
GUIDANCE INDICATES THAT TEMPERATURES PRECEDING THIS POTENTIAL LIGHT
QPF EVENT THE DAY BEFORE (THURSDAY) WILL WARM INTO THE 40S AS
CLOUDINESS GRADUALLY INCREASES ESPECIALLY IN THE AFTERNOON. WE WILL
UNDERCUT MOS GUIDANCE BY ABOUT 5 DEGREES TO TAKE INTO ACCOUNT THE
LINGERING ANOMALOUSLY SURFACE LAYER WITH CLOUDS INCREASING A TOP THE
LAYER. HIGHS SHOULD TOP OUT IN THE UPPER 30S NW TO UPPER 40S
FAYETTEVILLE TO GOLDSBORO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 250 AM TUESDAY...
ANY LIGHT GLAZING EARLY FRIDAY IN THE NW PIEDMONT SHOULD BE VERY
SHORT LIVED AS WARMING ALOFT OVERWHELMS THE COLUMN... EVEN IN THE
DAMMING REGION... EVEN IF THE WARMING IS SUBTLE AT THE SURFACE. THE
HYBRID CAD SHOULD LOCK IN OVER THE NORTHWEST PIEDMONT AND DEPENDING
ON THE QPF AND LIGHT RAIN COVERAGE... TEMPS MAY STRUGGLE TO REACH 40
AT WINSTON AND GREENSBORO. TO THE SE... A WARMER... WETTER AIR MASS
WILL SPREAD IN FROM THE OCEAN. THIS WILL SET UP A LARGE TEMPERATURE
GRADIENT FRIDAY WITH THE NW EXPERIENCING 40... AND THE SE
POTENTIALLY WARMING TO NEAR 60. AREAS OF LIGHT RAIN... DRIZZLE AND
FOG SHOULD LINGER MUCH OF THE DAY OVER THE PIEDMONT.
THE FORECAST FOR SATURDAY IF FOR THE HYBRID CAD TO EVENTUALLY
BREAK... AS A WARM FRONT SHIFTS NORTH INTO VA. THIS SHOULD ALLOW
MANY AREAS IN THE EAST TO REACH INTO THE 60S WITH LOWER TO MID 50S
CONFINED TO THE NW PIEDMONT. SKIES MAY REMAIN CLOUDY IN THE NW...
BUT BECOME PARTLY SUNNY IN THE EAST.
SUNDAY INTO EARLY NEXT WEEK BRINGS PLENTY OF UNCERTAINTY WITH THE
FORECAST OF A WET SUBTROPICAL LOW LIKELY BRINGING BACK RAIN CHANCES.
THE CURRENT OPERATIONAL MODELS ARE HAVING DIFFICULTY WITH THE WAVE
TRAIN OF PACIFIC SYSTEMS AND THE POTENTIAL BRIEF CUT OFF LOW OVER
THE SOUTHERN STATES DURING THIS TIME FRAME. REGARDLESS... ABOVE
AVERAGE HEIGHTS GUARANTEES WARMER THAN NORMAL TEMPERATURES INTO
EARLY TO THE MIDDLE OF NEXT WEEK. LOWS IN THE 40S AND POSSIBLY SOME
50S... WITH HIGHS IN THE 60S EXCEPT SOME 50S NW. UNTIL THE MODELS
RESOLVE THE SYSTEM ISSUES... WE WILL KEEP LOW CHANCE OF RAIN IN
SUNDAY THROUGH MONDAY.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1215 AM TUESDAY...
24-HR TAF PERIOD: VFR CONDITIONS WILL RULE THROUGH THE ENTIRE TAF
PERIOD IN ASSOCIATION WITH A VERY COLD/DRY ARCTIC AIRMASS ADVECTING
INTO THE REGION. EXPECT WNW WINDS SUSTAINED AT 10-15 KT WITH GUSTS
OF 20-25 KT THROUGH THE MORNING...EVENTUALLY BECOMING WESTERLY AND
DECREASING TO 5-10 KT BY MID TO LATE AFTERNOON AS THE MSLP GRADIENT
WEAKENS. EXPECT CALM OR LIGHT/VARIABLE WINDS BY OR SHORTLY AFTER
SUNSET AS THE SURFACE HIGH BECOMES CENTERED OVER THE REGION.
LOOKING AHEAD: VFR CONDITIONS ASSOC/W ARCTIC HIGH PRESSURE WILL
PREVAIL THROUGH WED. SUB-VFR CONDITIONS WILL BE POSSIBLE AT ALL
TERMINALS BY LATE THU/THU NIGHT AND INCREASINGLY LIKELY FRI-SUN AS
HIGH PRESSURE MOVES OFFSHORE...A SOUTHERLY RETURN FLOW DEVELOPS...
AND AN UPPER LEVEL TROUGH SLOWLY APPROACHES FROM THE WEST. -VINCENT
&&
.CLIMATE...
RECORD LOW TEMPERATURES FOR JANUARY 7TH...
RDU 15 1988
GSO 14 1988
FAY 13 1959
RECORD LOW MAXIMUM TEMPERATURES FOR JANUARY 7TH...
RDU 21 1988
GSO 21 1988
FAY 31 1988
RECORD LOW TEMPERATURES FOR JANUARY 8TH...
RDU 7 1970
GSO 6 1970
FAY 14 1970
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 AM TO NOON EST TUESDAY FOR NCZ011-
027-028-042-043-077-078-085-086-088-089.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST TUESDAY
FOR NCZ007>010-021>026-038>041-073>076-083-084.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...VINCENT
CLIMATE...BADGETT
AREA FORECAST DISCUSSION
NWS RALEIGH NC
243 AM EST TUE JAN 7 2014
.SYNOPSIS...ANOMALOUSLY COLD ARCTIC HIGH PRESSURE WILL SETTLE OVER
THE CAROLINAS AND VIRGINIA THROUGH WEDNESDAY. A GRADUAL WARMING
TREND WILL BEGIN ON THURSDAY AS HIGH PRESSURE MOVES OFFSHORE AND A
SOUTHERLY RETURN FLOW DEVELOPS ACROSS THE REGION.
&&
.NEAR TERM /TODAY THROUGH WEDNESDAY/...
AS OF 240 AM TUESDAY...
...POSSIBLY THE COLDEST DAY OF 2014...
THE WIND CHILL ADVISORY WILL REMAIN IN EFFECT FOR ALL OF CENTRAL NC
THROUGH NOON TODAY. ADVISORY CRITERIA HAS ALREADY BEEN MET (WIND
CHILL VALUES OF 0 TO -10F AS OF 07Z) IN MOST AREAS WEST OF HWY
1...WITH THE COASTAL PLAIN /I-95 CORRIDOR/ EXPECTED TO
MEET ADVISORY CRITERIA BY SUNRISE.
TODAY/TONIGHT: THE POLAR VORTEX (A COLD/EXPANSIVE UPPER LEVEL LOW)
CENTERED IN VICINITY OF JAMES BAY THIS MORNING WILL LIFT NORTHEAST
INTO THE CANADIAN MARITIMES THIS AFTERNOON/TONIGHT (TO A MORE
TYPICAL LOCATION NEAR BAFFIN ISLAND)...RESULTING IN SYNOPTIC
SUBSIDENCE /HEIGHT RISES ALOFT/ ACROSS THE CAROLINAS. THE STRONGEST
SYNOPTIC SUBSIDENCE AND HEIGHT RISES WILL OCCUR THIS MORNING...
REINFORCING SURFACE PRESSURE RISES ACROSS THE REGION AND PROLONGING
THE ADVECTION OF AN ANOMALOUSLY COLD (`TO BUILD A FIRE`) ARCTIC
AIRMASS INTO CENTRAL NC. FORECAST SOUNDINGS INDICATE A WELL MIXED
BOUNDARY LAYER EXTENDING UP TO 925-900 MB (2500-3500 FT AGL)...AND
THE DRY ADIABATIC METHOD WOULD SUGGEST HIGHS RANGING FROM THE UPPER
TEENS /NEAR 20F/ IN THE FAR NW PIEDMONT TO THE LOWER/MID 20S
ELSEWHERE (WARMEST SOUTH/SE). THOUGH THE ARCTIC AIRMASS WILL QUICKLY
BEGIN TO MODIFY TONIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS
WOULD SUGGEST LOWS IN THE LOWER/MID TEENS WED MORNING.
INTERESTINGLY...THE LATEST RAP FCST SOUNDINGS SHOW A POTENTIAL FOR
VERY SHALLOW INSTABILITY TO DEVELOP UNDER THE SUBSIDENCE INVERSION
THIS MORNING ACROSS PORTIONS OF THE SANDHILLS/SE COASTAL PLAIN AND
THIS AFTERNOON IN THE PIEDMONT BY VIRTUE OF STEEP LAPSE RATES
ASSOC/W SUCH A COLD LOW-LEVEL AIRMASS (-12 TO -15C AT 900 MB)...
THOUGH IT IS DIFFICULT TO BELIEVE THAT SUFFICIENT LOW-LEVEL MOISTURE
WILL BE IN PLACE FOR VERY SHALLOW CU/TCU TO DEVELOP GIVEN SUCH A DRY
AIRMASS (PER 00Z GSO RAOB) AND THAT IT IS TYPICALLY DIFFICULT FOR
ANY UPSTREAM MOISTURE TO ADVECT EAST OF THE SOUTHERN APPALACHIANS IN
THIS TYPE OF REGIME. GIVEN THAT TEMPS AT THE TOP OF THE MIXED LAYER
WILL FALL WITHIN THE ICE NUCLEATION ZONE (I.E. -12 TO -15C)...IF LOW-
LEVEL MOISTURE IS SUFFICIENT IT WOULD AT LEAST BE POSSIBLE FOR
SHALLOW CU/TCU TO DEVELOP AND PERHAPS PRODUCE A FEW FLURRIES. WITH
THE ABOVE IN MIND...FEEL THAT THE AFOREMENTIONED SCENARIO IS TOO
UNLIKELY TO WARRANT MENTION IN THE FCST AT THIS TIME AND WILL
MAINTAIN A DRY FORECAST THROUGH TONIGHT.
WEDNESDAY: HIGH PRESSURE CENTERED OVER THE REGION WED MORNING WILL
GRADUALLY SHIFT OFFSHORE WED NIGHT AS SHORTWAVE ENERGY IN ZONAL FLOW
ALOFT APPROACHES THE SOUTHERN APPALACHIANS FROM THE WEST. WITH DRY
HIGH PRESSURE OVER THE REGION DURING THE DAY...EXPECT CONTINUED
COLD/CLEAR CONDITIONS WITH HIGHS IN THE UPPER 30S (NORTH) TO LOWER
40S (SOUTH). -VINCENT
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 221 AM TUESDAY...
EVEN WITH THE AFOREMENTIONED BITTERLY COLD AIR MASS PULLING OUT
RAPIDLY TO THE NE AND RAPIDLY RISING HEIGHTS ALOFT... THE LINGERING
SURFACE HIGH PRESSURE OVER OUR REGION SHOULD BRING ANOTHER COLD
NIGHT FOR WEDNESDAY NIGHT. MOSTLY CLEAR SKIES WITH LOWS IN THE LOWER
TO MID 20S EXPECTED WITH SOME UPPER TEENS IN THE NORMALLY COLDER
SPOTS.
MODERATION WILL CONTINUE ON THURSDAY AS THE MAIN SURFACE HIGH
PRESSURE BECOMES ESTABLISHED OVER NEW ENGLAND BUT EXTENDING INTO
NC/SC FROM THE NORTH BEFORE SHIFTING SLOWLY OFFSHORE BY FRIDAY
MORNING. AS THE HIGH PRESSURE SHIFTS EASTWARD... WAA WILL COMMENCE
ALOFT AND THIS WILL OVERRUN THE COLD STABLE NEAR SURFACE LAYER BY
LATE THURSDAY AND THURSDAY NIGHT. SOME MODELS AND ENSEMBLE MEMBERS
SPIT OUT A FEW HUNDREDTHS OF PRECIPITATION BETWEEN 06Z-12Z FRIDAY...
MAINLY OVER THE PIEDMONT. P-TYPE WITH WARMING ALOFT WOULD BE
LIQUID... BUT CONCERNS REMAIN WITH THE VERY COLD DRY SURFACE LAYER
OF SOME LIGHT GLAZE OR ICING IN THE PIEDMONT (ESPECIALLY IN THE
TRIAD REGION) LATE THURSDAY NIGHT (SIMILAR TO THE EVENT LAST
SUNDAY). THERE APPEARS TO BE SIGNIFICANT EVAPORATIONAL COOLING
POTENTIAL THURSDAY NIGHT THAT IF ENOUGH LIGHT RAIN FALLS... TEMPS
WOULD COOL RAPIDLY TO NEAR 30 IN THE TRIAD. CURRENT SURFACE WET BULB
FORECASTS INDICATE THIS POTENTIAL... WITH LESSER CHANCES OF ANY
ICING AT RDU... TO NIL IN THE FAY/GSB/RWI AREAS OF THE WARMER
SANDHILLS AND COASTAL PLAIN. CURRENT POP IS 50 OR LESS... OR LESS
THAN LIKELY... WITH QPF OF A FEW HUNDREDTHS IF IT MATERIALIZES.
FOR NOW... WE WILL ADD MENTION OF LIGHT RAIN POSSIBLY MIXED WITH
FREEZING RAIN EARLY (IN THE TRIAD ZONES ONLY)... WITH A CHANCE OF
LIGHT RAIN ELSEWHERE. LOWS 30-38 NW TO SE. IN ADDITION... MOST
GUIDANCE INDICATES THAT TEMPERATURES PRECEDING THIS POTENTIAL LIGHT
QPF EVENT THE DAY BEFORE (THURSDAY) WILL WARM INTO THE 40S AS
CLOUDINESS GRADUALLY INCREASES ESPECIALLY IN THE AFTERNOON. WE WILL
UNDERCUT MOS GUIDANCE BY ABOUT 5 DEGREES TO TAKE INTO ACCOUNT THE
LINGERING ANOMALOUSLY SURFACE LAYER WITH CLOUDS INCREASING A TOP THE
LAYER. HIGHS SHOULD TOP OUT IN THE UPPER 30S NW TO UPPER 40S
FAYETTEVILLE TO GOLDSBORO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 300 PM MONDAY...
FRIDAY WILL BEGIN WITH WHAT LOOKS LIKE A HYBRID CAD WEDGE LOCKED IN
OVER THE NORTHWEST PIEDMONT AND A WARMER...WETTER AIRMASS TO THE
SOUTHEAST. THIS WILL SET UP A LARGE MAX TEMPERATURE GRADIENT ON
FRIDAY WITH THE NW EXPERIENCING MID 40S TO THE UPPER 50S IN THE
SOUTHEAST. BY FRIDAY NIGHT MOST OF THE AREA SHOULD BE BROKEN TO
OVERCAST WITH PRECIPITATION CHANCES BEING PRESENTED BY THE
ISENTROPIC LIFT AND MOISTURE FETCH FROM THE SOUTHWEST ATLANTIC. LOWS
FRIDAY NIGHT MID 30S TO MID 40S.
SATURDAY MORNING THE WEDGE BEGINS TO BREAK DOWN...PRESSURED BY AN
APPROACHING FRONTAL SYSTEM EXTENDING SOUTHWARD FROM THE OHIO VALLEY.
SOUTHWESTERLY FLOW WILL TAKE OVER AND STRONG WARM AIR ADVECTION WILL
HELP TEMPERATURES RISE INTO THE MID 50S TO LOW 60S...DESPITE THE
OVERCAST SKIES. THE CHANCES FOR RAIN ARE VERY GOOD ALONG THE FRONT
AND BOTH MODELS ARE IN FAIRLY GOOD AGREEMENT THAT OUTDOOR PLANS MAY
BE HINDERED SATURDAY AFTERNOON. THE FRONT IS PROGGED TO CROSS THE
AREA SATURDAY NIGHT BUT ANY COLD AIR ADVECTION WILL BE FAIRLY SHORT
LIVED AS A LOW DEVELOPING IN THE THE GULF OF MEXICO WILL BEGIN TO
TAKE OVER AND AN INVERTED TROUGH KEEPS SOUTHEASTERLY FLOW AT LEAST
IN THE SOUTHEASTERN HALF OF THE CWA AROUND FOR THE DAY. THIS WILL
KEEP TEMPS SUNDAY IN THE MID 50S TO LOW 60S FROM NW TO SE AND FAIRLY
DRY ALTHOUGH OVERCAST. SO RIGHT NOW...SUNDAY LOOKS LIKE THE BETTER
DAY OF THE WEEKEND FOR OUTDOOR PLANS. LOWS IN THE LOW TO MID 40S
SUNDAY NIGHT.
UNCERTAINTY WITH THE TRACK OF THE SOUTHERN LOW BETWEEN THE MODELS
MAKES PRECIPITATION CHANCES DIFFICULT TO PREDICT FOR MONDAY
AFTERNOON. THE GFS FAVORS A COASTAL TRACK AND KEEPS THE NW DRIER AND
THE ECMWF LAGS AND FAVORS A MORE WESTERLY TRACK WHICH WOULD MAKE
PRECIP CHANCES GREATER IN THE NW VS THE SE. EITHER WAY IT WILL STILL
BE WARM WITH HIGHS IN THE MID 50S TO LOW 60S.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
AS OF 1215 AM TUESDAY...
24-HR TAF PERIOD: VFR CONDITIONS WILL RULE THROUGH THE ENTIRE TAF
PERIOD IN ASSOCIATION WITH A VERY COLD/DRY ARCTIC AIRMASS ADVECTING
INTO THE REGION. EXPECT WNW WINDS SUSTAINED AT 10-15 KT WITH GUSTS
OF 20-25 KT THROUGH THE MORNING...EVENTUALLY BECOMING WESTERLY AND
DECREASING TO 5-10 KT BY MID TO LATE AFTERNOON AS THE MSLP GRADIENT
WEAKENS. EXPECT CALM OR LIGHT/VARIABLE WINDS BY OR SHORTLY AFTER
SUNSET AS THE SURFACE HIGH BECOMES CENTERED OVER THE REGION.
LOOKING AHEAD: VFR CONDITIONS ASSOC/W ARCTIC HIGH PRESSURE WILL
PREVAIL THROUGH WED. SUB-VFR CONDITIONS WILL BE POSSIBLE AT ALL
TERMINALS BY LATE THU/THU NIGHT AND INCREASINGLY LIKELY FRI-SUN AS
HIGH PRESSURE MOVES OFFSHORE...A SOUTHERLY RETURN FLOW DEVELOPS...
AND AN UPPER LEVEL TROUGH SLOWLY APPROACHES FROM THE WEST. -VINCENT
&&
.CLIMATE...
RECORD LOW TEMPERATURES FOR JANUARY 7TH...
RDU 15 1988
GSO 14 1988
FAY 13 1959
RECORD LOW MAXIMUM TEMPERATURES FOR JANUARY 7TH...
RDU 21 1988
GSO 21 1988
FAY 31 1988
RECORD LOW TEMPERATURES FOR JANUARY 8TH...
RDU 7 1970
GSO 6 1970
FAY 14 1970
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 AM TO NOON EST TUESDAY FOR NCZ011-
027-028-042-043-077-078-085-086-088-089.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST TUESDAY
FOR NCZ007>010-021>026-038>041-073>076-083-084.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...BADGETT
LONG TERM...RTE
AVIATION...VINCENT
CLIMATE...BADGETT
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1137 PM CST MON JAN 6 2014
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 243 PM CST MON JAN 6 2014
CURRENTLY AS OF 20Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED RIDGING OVER THE WESTERN U.S. INTO BRITISH COLUMBIA AND AN
ANOMALOUSLY DEEP TROUGH ENCOMPASSING MUCH OF THE EASTERN U.S..
WITHIN THIS DEEP TROUGH...THE POLAR VORTEX STRETCHED FROM NORTHERN
ONTARIO INTO LOWER MI. THE COLDEST AIR ASSOCIATED WITH THE VORTEX
HAS BEEN ON ITS BACK SIDE...NOTED BY 925MB TEMPS AT 12Z OF -34C AT
MPX AND -35C AT INL...OR 3-3.5 STANDARD DEVIATIONS BELOW NORMAL.
THIS ARCTIC AIR HAS MODIFIED SOMEWHAT THROUGH DAYTIME HEATING...BUT
925MB TEMPS PER RAP ANALYSIS ARE STILL NEAR -30C. SURFACE
TEMPERATURES HAVE MANAGED TO CLIMB INTO THE TEENS BELOW ZERO.
HOWEVER...A PERSISTENT 10 TO 20 MPH WIND WITH GUSTS TO 30 MPH HAVE
KEPT WIND CHILLS DOWN TO 35 TO 45 BELOW ZERO. THESE WINDS ARE A
RESULT OF A TIGHT PRESSURE GRADIENT BETWEEN A SURFACE RIDGE OVER
THE DAKOTAS AND A DEEP LOW OVER CENTRAL QUEBEC.
THE POLAR VORTEX IS PROGGED TO GRADUALLY LOSE ITS GRIP ACROSS THE
FORECAST AREA AND GREAT LAKES REGION...LIFTING INTO NORTHERN QUEBEC
BY 00Z WEDNESDAY. THIS WILL ALLOW WARMER AIR TO ENTER THE
REGION. ONE CAVEAT TO THE WARMER AIR IS A SHORTWAVE OVER THE
NORTHWEST TERRITORIES WHICH MODELS SHOW DROPPING DOWN THE BACK SIDE
OF THE VORTEX...COMING INTO NORTHERN WI AT 00Z WEDNESDAY. THIS
SHORTWAVE WILL SLOW SOME OF THE WARM UP.
REGARDING TEMPERATURES...925MB READINGS ARE PROGGED TO CLIMB THROUGH
THE NEXT 24 HOURS...REACHING -24 TO -28C BY 12Z TUE AND TO -18 TO -
22C BY 00Z WED. DESPITE THE WARMING ABOVE THE SURFACE...TEMPERATURES
SHOULD STILL COOL DOWN CLOSE TO READINGS SEEN LAST NIGHT BECAUSE OF
WINDS WHICH ARE GOING TO BE LIGHTER. HOWEVER...A BREEZE WILL PERSIST
SINCE THE SURFACE RIDGE IS STILL OFF TO OUR WEST...WHICH MEANS WIND
CHILL VALUES ARE LIKELY TO STAY BETWEEN 35 AND 55 BELOW ZERO. WINDS
DO MANAGE TO BACK MORE WEST TO POSSIBLY EVEN SOUTHWEST ON TUESDAY...
AHEAD OF A COLD FRONT DROPPING THROUGH MN THAT IS ACCOMPANYING THE
NORTHWEST TERRITORIES SHORTWAVE. THIS BACKING OF WINDS PLUS WARMER
925MB VALUES AND SOME SUN SHOULD HELP BOOST HIGHS TOWARDS THE SINGLE
DIGITS ABOVE ZERO...AT LEAST SOUTHWEST OF I-94. NORTH OF I-94...WIND
CHILL ISSUES ARE GOING TO CONTINUE THROUGH THE AFTERNOON AND AN
ADVISORY WILL BE NEEDED AFTER THE WARNING EXPIRES.
SKY COVER REMAINS A TRICKY FORECAST IN THIS ARCTIC AIRMASS.
ANTICIPATING A PERIOD OF POSSIBLY CLEAR SKIES THIS EVENING ONCE ANY
DIURNAL STRATOCUMULUS DISSIPATES WITH LOSS OF DAYTIME HEATING.
HOWEVER...LOW STRATUS CURRENTLY IN SOUTHERN MANITOBA AND NORTHWEST
MN LOOKS TO MAKE A RUN AT LOCATIONS NORTH OF I-94 LATE THIS EVENING
INTO THE OVERNIGHT HOURS. MID/HIGH CLOUDS SHOULD THEN INCREASE
OVERNIGHT THROUGH TUESDAY...WITH EVEN SOME LOWER STRATUS ACROSS
SOUTHERN PORTIONS OF THE AREA...AS ISENTROPIC LIFT PICKS UP AHEAD
OF THE COLD FRONT AND SHORTWAVE. SOME FLURRIES COULD OCCUR FROM
THE CLOUDS AS WELL ACROSS THE SOUTHWESTERN HALF OF THE AREA ON
TUESDAY AS CLOUD HEIGHTS THERE FALL.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 243 PM CST MON JAN 6 2014
MODELS REMAIN IN AGREEMENT SHOWING THE PATTERN GREATLY DEAMPLIFYING
ACROSS THE U.S....BECOMING ZONAL BY THURSDAY MORNING. THIS WILL
SHIFT THE TEMPERATURE FLOW FROM THE ARCTIC TO THE PACIFIC. WE DO
HAVE TO WAIT JUST A LITTLE BIT LONGER AS THAT SHORTWAVE DROPPING
INTO NORTHERN WISCONSIN BRINGS A BRIEF REINFORCING SHOT OF COLD AIR
TUESDAY NIGHT. THIS SHOT OF COLD AIR WILL BE NOTICED THE MOST IN
NORTHERN WI WHERE WIND CHILLS LOOK TO STAY DOWN BETWEEN 20 AND 35
BELOW ZERO. A SURFACE HIGH PRESSURE AREA IS PROGGED TO DRIFT
ACROSS THE FORECAST AREA LATE WEDNESDAY INTO WEDNESDAY NIGHT. THIS
HIGH SHOULD HELP TO CALM THE WINDS DOWN...WHICH DOES BRING A
CONCERN FOR LOW TEMPERATURES WEDNESDAY NIGHT...ESPECIALLY OVER
WISCONSIN. AIRMASS REMAINS QUITE DRY WITH PRECIPITABLE WATER BELOW
0.1 INCHES...SO TEMPERATURES COULD REALLY TANK IN THE TYPICALLY
COLD SPOTS. SOUTHERLY FLOW ON THE BACK SIDE OF THIS HIGH PRESSURE
AREA KICKS WARM ADVECTION INTO HIGH GEAR ON THURSDAY. 925MB TEMPS
CLIMB TO -6 TO -10C. ALTHOUGH THERE MAY BE QUITE A FEW CLOUDS
AROUND...THESE SOUTHERLY WINDS SHOULD HELP PROPEL TEMPERATURES
GENERALLY INTO THE MID TEENS TO AROUND 20...ABOUT 30 DEGREES
WARMER THAN TODAY. NOTE...THERE COULD BE SOME WIND CHILL ISSUES
THURSDAY MORNING AS THE SOUTH WINDS INCREASE. THERE WERE SOME
HINTS OF THE 06.15Z SREF OF SOME POSSIBLE PRECIPITATION WITH THIS
WARM ADVECTION...BUT KEPT THESE OUT WITH NO OTHER DETERMINISTIC
MODEL GUIDANCE SHOWING IT.
HIGHLIGHTS FOR FRIDAY INTO MONDAY...
1. GOOD MODEL AGREEMENT EXISTS THAT A FAIRLY SIGNIFICANT SHORTWAVE
TROUGH WILL MOVE FROM THE PACIFIC NORTHWEST ON THU...TO THE NORTHERN
PLAINS ON FRI AND GREAT LAKES ON SAT. A PLUME OF HIGHER PRECIPITABLE
WATER ON THE ORDER OF A 0.5-0.7 INCHES COMES INTO THE REGION AHEAD
OF THE TROUGH ON FRIDAY. COMBINING THIS MOISTURE WITH THE DPVA AND
ISENTROPIC LOOKS TO YIELD SOME PRECIPITATION. HAVE RAISED POPS ABOUT
5-10 PERCENT...BUT IF THE TRENDS IN THE 06.12Z GFS/ECMWF CONTINUE
THESE CHANCES NEED TO BE RAISED FURTHER. NOTE THAT THE 06.12Z
CANADIAN HOLDS PRECIPITATION OFF TIL FRIDAY NIGHT...WHICH IS PARTLY
THE CAUSE TOO OF THE SMALLER CHANCE INCREASE. THE TYPE IS
SOMEWHAT OF AN ISSUE TOO...DUE TO A LOSS OF ICE IN THE CLOUD AND
WARM LAYER INITIALLY FRIDAY MORNING. IT APPEARS ONCE THINGS
SATURATE...EVAPORATIVE COOLING KNOCKS DOWN ANY WARM LAYER AND CLOUDS
ARE SEEDED WITH ICE. THIS SHOULD OCCUR BY EARLY AFTERNOON.
PRECIPITATION SHOULD END WEST TO EAST FRIDAY NIGHT AS THE SYSTEM
PULLS AWAY. ANY LOSS OF ICE IN THE CLOUDS FRIDAY NIGHT SHOULD OCCUR
AFTER THE PRECIP EXITS.
2. A SERIES OF TWO SHORTWAVE TROUGHS TRACKING ACROSS THE REGION
SUNDAY THROUGH MONDAY. PREVIOUSLY ECMWF RUNS WERE SUGGESTING THAT
THESE TROUGHS WERE GOING TO HOLD BACK OVER THE WESTERN U.S.. NOW
THEY ARE MORE PROGRESSIVE...LIKE THE 05.12Z GFS RUN. THIS MEANS A
BIT LESS CONFIDENCE IN PRECIPITATION AS MOISTURE RETURN BEHIND THE
SATURDAY SYSTEM IS SLOWER TO COME BACK. THEREFORE...CHANCES WERE
LOWERED. IT IS ENTIRELY POSSIBLE SUNDAY THROUGH MONDAY ENDS UP
MAINLY DRY.
3. ABOVE NORMAL TEMPERATURES. BOTH THE FRIDAY AND SUNDAY SHORTWAVE
TROUGHS HELP TO PULL EVEN WARMER AIR INTO THE REGION. 925MB TEMPS
GET UP CLOSE TO 0C ON FRIDAY...COOL SLIGHTLY TO -2 TO -6C ON
SATURDAY...BACK UP TO 0-3C ON SUNDAY AND DOWN TO -2 TO -6C ON
MONDAY. EACH OF THESE DAYS WE SHOULD BE ABLE TO GET HIGHS INTO THE
UPPER 20S TO LOW 30S...AND SUNDAY THERE ARE SIGNS WE COULD TRY TO
PUSH 40. RAISED HIGHS A LITTLE ON SUNDAY AS A RESULT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1137 PM CST MON JAN 6 2014
LOOKS LIKE WE HAVE SEEN THE WORST OF THE COLD. WARM ADVECTION
CLOUD ALREADY STREAMING IN FROM THE WEST. LOOKS LIKE ONLY MID AND
HIGH CLOUD WILL MAKE IT TO THE TAF LOCATIONS...AS LATEST MODEL
RUNS SUGGEST THE LOWER CEILINGS WILL REMAIN SOUTH OF BOTH TAF
FORECAST LOCATIONS.
&&
.CLIMATE...
ISSUED AT 243 PM CST MON JAN 6 2014
SO FAR NO RECORDS HAVE BEEN SET AT EITHER LA CROSSE OR ROCHESTER.
HOWEVER...A FEW RECORD LOW TEMPERATURES WERE SET AT COOPERATIVE
OBSERVER SITES...
BYRON MN...........-24. OLD RECORD -10 IN 2010
FRIENDSHIP WI......-22. OLD RECORD -18 IN 1942
OWEN WI............-26. OLD RECORD -26 IN 1979
WINONA DAM 5A MN...-21 OLD RECORD -12 IN 1942
THE COLDEST THE WIND CHILL GOT TO IN LA CROSSE WAS -48 AND AT
ROCHESTER WAS -53. NEITHER MADE IT INTO THE TOP 10...BUT WERE ONLY
ABOUT 5 DEGREES WARMER THAN THE FEBRUARY 2-3 1996 ARCTIC OUTBREAK.
SEE OUR TOP NEWS STORY ON OUR WEBSITE WWW.WEATHER.GOV/ARX FOR MORE
CLIMATE INFORMATION ON THE COLD.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ017-029-032>034-
041>044-053>055-061.
MN...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR MNZ079-086>088-
094>096.
IA...WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR IAZ008>011-018-019-
029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...MW
CLIMATE...AJ
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1022 PM CST MON JAN 6 2014
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 825 PM CST MON JAN 6 2014
NO CHANGE TO HEADLINES THIS EVENING. PLAN IS TO POST A WIND CHILL
ADVISORY ONCE THE WARNING EXPIRES AT NOON TOMORROW. LOOKING AT OUR
CURRENT GRIDS...WOULD GUESS NOON TUE-NOON WED FOR TIMING OF THE
ADVISORY...BUT THAT COULD CHANGE DEPENDING ON ANY CHANGES TO THE
T/WIND/APPARENT-T FCST.
UPDATED WSW AND HWO JUST SENT.
&&
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 231 PM CST MON JAN 6 2014
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE STRETCHING FROM SOUTHERN SASKATCHEWAN TO THE GULF COAST OF
TEXAS EARLY THIS AFTERNOON. THE POLAR VORTEX IS SHIFTING EAST INTO
MICHIGAN THOUGH THE CORE OF THE EXTREMELY COLD AIR IS CURRENTLY
OVERHEAD. TEMPERATURES HAVE NOT WARMED TOO MUCH SO FAR TODAY...WITH
READINGS HOLDING STEADY FROM THE LOWER TEENS BELOW ZERO ALONG THE
LAKE MICHIGAN SHORELINE TO THE LOWER 20S BELOW ZERO OVER CENTRAL
WISCONSIN. WIND CHILLS REMAIN IN THE 35 TO 45 DEGREES BELOW ZERO
RANGE. AREAS OF THIN CLOUD COVER CONTINUE TO STREAM SOUTHEAST ON
THE BACKSIDE OF THE POLAR VORTEX...WITH A FEW FLURRIES BEING
REPORTED ON AREA OBSERVATION SITES. AS THE ARCTIC AIR
MODIFIES...TEMPS AND WIND CHILLS REMAIN THE MAIN FORECAST
CONCERNS...FOLLOWED BY CLOUDS/FLURRY CHANCES.
TONIGHT...ARCTIC HIGH PRESSURE WILL SLIDE TO THE GULF COAST...BUT
THE SURFACE RIDGE AXIS WILL HANG BACK ACROSS THE NORTHERN
MISSISSIPPI TO CENTRAL CANADA. THOUGH TEMPERATURES WILL BE
MODIFYING ALOFT...BRISK WEST WINDS WILL CONTINUE TO FUNNEL IN THE
EXTREME COLD FROM THE NORTHERN PLAINS. DO NOT HAVE A GOOD HANDLE ON
CLOUD COVER TONIGHT...BUT WITH THIN CLOUDS DROPPING SOUTH OVER
SOUTHERN CANADA AND MINNESOTA...FIGURE THE REGION WILL HAVE PARTLY
CLOUDY CONDITIONS THROUGH THE EVENING BEFORE A SLIGHT BACKING OF THE
WINDS PUSHES IN DRIER AIR IN AFTER MIDNIGHT. WITH THE SUSTAINED
WINDS AND A MODIFYING AIRMASS...TEMPS WILL BE A DEGREE OR TWO WARMER
OVER WESTERN SECTIONS OF THE FORECAST AREA...THOUGH WILL LIKELY BE A
FEW DEGREES COLDER OVER EASTERN SECTIONS. BUT WITH WINDS REMAINING
IN THE 10-15KT RANGE...WIND CHILLS WILL REMAIN IN THE 40 TO 50
DEGREE BELOW ZERO RANGE. THUS NO CHANGE TO HEADLINES.
TUESDAY...THE SURFACE RIDGE AXIS WILL SHIFT SLIGHTLY INTO WESTERN
WISCONSIN IN THE AFTERNOON WITH ONLY MID AND HIGH CLOUDS MOVING
OVERHEAD. THE WEST WINDS WILL NOT BE AS STRONG OR GUSTY AS
TODAY...AND COMBINED WITH FURTHER MODIFYING OF THE ARCTIC
AIRMASS...SHOULD SEE TEMPS ABOUT 10 DEGREES WARMER THAN TODAY
ACCORDING TO THE LEADING GUIDANCE. THE EXTREMELY COLD WIND CHILLS
ARE EXPECTED TO RISE TO BETWEEN 20 TO 30 DEGREES BELOW ZERO BY EARLY
AFTERNOON.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 231 PM CST MON JAN 6 2014
GRADUALLY IMPROVING TEMPERATURES THIS WEEK WILL BE THE PRIMARY
ISSUE FOLLOWED WITH SOME RESOLUTION WITH A FEW PRECIP CHANCES IN
THE NEAR ZONAL FLOW LATE THIS WEEK AND THROUGH THIS WEEKEND.
FOR STARTERS...ANTICIPATE THE ARCTIC AIR MASS WILL TAKE ITS TIME
TO DEPART THIS WEEK EVEN THOUGH H850 TEMPERATURES INCREASE. VERY
COLD DRY AIR MASS WILL BE RECYCLED BACK NORTH WITH THE RETURN FLOW
THROUGH THURSDAY. ANTICIPATED CLEAR SKIES AND LIGHT WINDS UNDER A
COLD HIGH PRESSURE SYSTEM WILL PROVIDE LARGE DIURNAL CHANGES WITH
SUB ZERO LOW TEMPERATURES CONTINUING INTO THURSDAY MORNING OVER
MOST LOCATIONS.
RETURN SOUTH TO SOUTHWEST FLOW BEGINS LATER THURSDAY SO TEMPS
WILL START TO ASCEND QUICKER WITH TEMPERATURES POSSIBLY REACHING
THE FREEZING MARK THIS WEEKEND OVER PARTS OF THE AREA. CLOUDS MAY
BE ON THE INCREASE OVER SOUTHERN WISCONSIN THROUGH THURSDAY WITH
THE PASSAGE OF A SOUTHERN STREAM SYSTEM TO THE SOUTH...BUT EXPECT THE
AREA TO REMAIN DRY WITH THE SURFACE HIGH STILL SETTLED OVER THE
AREA.
MODEL TIMING OF VARIOUS SHORT WAVES IN THE NEAR ZONAL FLOW POINTING
TO A FRIDAY INTO FRIDAY NIGHT TIME FRAME. A WEAK RIDGE SETTLES
OVER SATURDAY INTO SUNDAY BEFORE POSSIBLY ANOTHER WEAK SYSTEM
PASSES OVER LATER SUNDAY. AGAIN MODEL TIME IN QUESTION DUE TO
TIMING OF THESE SHORT WAVES IN THE ZONAL FLOW AND LIKELY WILL NEED
FURTHER ADJUSTMENTS.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1021 PM CST MON JAN 6 2014
VFR CONDITIONS EXPECTED AS BITTERLY COLD ARCTIC AIR DOMINATES THE
AREA. THOUGH MARGINAL...WL INCLUDE LLWS OVERNIGHT AS SFC WINDS
HAVE COME DOWN A BIT...AND INVERSION WL STRENGTHEN/LOWER BY
MORNING.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL NOON CST TUESDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
UPDATE.........SKOWRONSKI
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......SKOWRONSKI
AREA FORECAST DISCUSSION
NWS ALBANY NY
924 AM EST TUE JAN 7 2014
.SYNOPSIS...
A BROAD CYCLONIC FLOW OF FRIGID ARCTIC AIR WILL CONTINUE OVER THE
REGION THROUGH THE MIDDLE OF THE WEEK...WITH DANGEROUSLY COLD WIND
CHILLS AND BITTERLY COLD TEMPERATURES. PERSISTENT WESTERLY WINDS
WILL BRING SIGNIFICANT LAKE EFFECT SNOW DOWNWIND OF LAKE ONTARIO
INTO THE WESTERN ADIRONDACKS. A MODERATING TREND IS EXPECTED TOWARDS
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 924 AM EST...TEMPERATURES REMAIN IN THE SINGLE DIGITS OVER
MUCH OF THE REGION THIS MORNING. PERSISTENT AND GUSTY WESTERLY
WINDS MAKING IT FEEL EVEN COLDER...WITH WIND CHILLS GENERALLY IN
THE -10 TO -25 DEGREE RANGE.
WIND CHILL WARNINGS REMAIN IN EFFECT FOR THE EASTERN
CATSKILLS...WITH WIND CHILL ADVISORIES FOR THE REST OF THE AREA.
TEMPERATURES WILL NOT MOVE MUCH TODAY...WITH HIGHS ONLY REACHING
AROUND 10 IN THE HUDSON VALLEY...WITH SINGLE DIGITS OVER THE
HIGHER TERRAIN. AGAIN...WIND CHILLS WILL MAKE IT FEEL EVEN COLDER
THROUGHOUT THE DAY. WITH A STRONG PRESSURE GRADIENT REMAINING OVER
THE REGION...WESTERLY WINDS WILL CONTINUE AT 20 TO 30 MPH...WITH
GUSTS OF 40 TO 45 MPH EXPECTED ESPECIALLY IN FAVORED WEST-EAST
ORIENTED VALLEYS AND HIGHER TERRAIN AREAS.
THE OTHER MAIN STORY TODAY WILL BE HEAVY LAKE EFFECT SNOW FOR
PORTIONS OF THE WESTERN ADIRONDACKS...ESPECIALLY NORTHERN HERKIMER
AND NORTHWEST HAMILTON COUNTIES. OVER THE LAST FEW HOURS...THE
BAND HAS SHIFTED NORTH INTO EXTREME NORTHERN HERKIMER COUNTY. THE
SNOW BAND IS NOW NORTH OF OLD FORGE AND STILLWATER
RESERVOIR...AFFECTING THE DEEP WOODS OF THE NORTHWESTERN CORNER OF
THE ADIRONDACK PARK. THE 12Z RUN OF LOCAL HIRESWRF AND THE LATEST
12Z RUN OF THE 3KM HRRR ALL SUGGEST THE BAND TO SLOWLY MOVE AND
SHIFT DURING THE DAY. EVENTUALLY...IT WILL BEGIN TO SHIFT BACK
SOUTH TOWARDS THE OLD FORGE AREA BY LATER THIS AFTERNOON AND INTO
THE EVENING.
WE ARE STILL CONFIDENT FOR THE SNOW BAND TO EXTEND THROUGH
NORTHERN HERKIMER AND INTO WESTERN HAMILTON COUNTY TODAY AS A
MULTI-LAKE CONNECTION FROM LAKE HURON EVENTUALLY OCCURS. LOCAL
CSTAR RESEARCH INDICATES WITHIN AN EXTREME LAKE-AIR INSTABILITY
REGIME SUCH AS THIS ONE...THE INLAND EXTENT WILL BE RATHER LIMITED
UNTIL A MULTI- LAKE CONNECTION IS ESTABLISHED. WE CUT BACK
SLIGHTLY ON THE AREAL COVERAGE OF THE HEAVIEST ACCUMULATIONS BUT
ARE STILL EXPECTING 12 TO 30 INCHES IN THE MOST PERSISTENT BANDS
MAINLY FROM AROUND OLD FORGE AND ALONG ROUTE 28 NORTHWARD. THE
HEAVIEST ACCUMULATIONS OF NEAR 30 INCHES WILL PROBABLY WIND UP
OCCURRING SOMEWHERE IN THE FOREST BETWEEN STILLWATER RESERVOIR AND
THE ST. LAWRENCE COUNTY BORDER.
OUTSIDE OF THE INTENSE LAKE EFFECT SNOW OVER THE WESTERN
ADIRONDACKS...ONLY SOME LIGHT SNOW SHOWERS ARE EXPECTED FOR LIMITED
AREAS OF THE SOUTHERN GREEN MOUNTAINS IN VERMONT. SKIES WILL BE
MOSTLY TO PARTLY SUNNY ACROSS THE REMAINDER OF THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS WILL CONTINUE THROUGH
TONIGHT AND INTO WEDNESDAY MORNING. A WESTERLY BREEZE WILL PERSIST
DURING THE TIME...WITH TEMPERATURES EXPECTED TO BE IN THE SINGLE
DIGITS TO BELOW ZERO. THUS WILL CONTINUE ALL WIND CHILL HEADLINES
THROUGH 10 AM WEDNESDAY. TEMPERATURES ON WEDNESDAY WILL STILL BE
WELL BELOW NORMAL...ALTHOUGH MID TO UPPER TEENS ARE EXPECTED FOR
HIGHS RATHER THAN SINGLE DIGITS.
IT WILL BE DRY ACROSS MUCH OF THE AREA...ALTHOUGH HEAVY LAKE EFFECT
SNOW SHOULD CONTINUE ACROSS THE WESTERN ADIRONDACKS...AGAIN WITH THE
MOST PERSISTENT AND HIGHEST ACCUMULATIONS MAINLY FROM OLD FORGE AND
ROUTE 28 NORTHWARD TONIGHT INTO WEDNESDAY MORNING. LOCAL INLAND
EXTENT TOOL FROM CSTAR RESEARCH INDICATING THE SNOW BAND MAY EVEN
EXTEND WELL EASTWARD INTO NORTHERN HAMILTON COUNTY...WITH
ACCUMULATING SNOW ALL THE WAY TO INDIAN LAKE. ACTIVITY IS EXPECTED
TO GRADUALLY WEAKEN BY WEDNESDAY AFTERNOON AS CAPPING INVERSION
HEIGHTS LOWER TO AROUND 1 KM.
WILL MENTION JUST CHANCE POPS FOR SOME LEFTOVER WEAK LAKE EFFECT
SNOW SHOWERS OVER THE WESTERN ADIRONDACKS WEDNESDAY
NIGHT...OTHERWISE DRY CONDITIONS SHOULD PERSIST. TEMPERATURES WILL
CONTINUE TO BE BELOW NORMAL ALTHOUGH WITH LESS WIND. HIGH PRESSURE
WILL BUILD INTO THE REGION ON THURSDAY...WITH DRY CONDITIONS AND
TEMPERATURES MODERATING TO ONLY SLIGHTLY BELOW NORMAL READINGS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
EXPECT RELATIVELY MILD TEMPERATURES DURING THE LONG TERM PERIOD AS
SOUTHERLY/SOUTHWESTERLY FLOW DOMINATES MOST OF THE TIME.
SPOTTY LIGHT SNOW SHOWERS POSSIBLE THURSDAY NIGHT INTO FRIDAY AS A
VERY WEAK DISTURBANCE MOVES THROUGH ALONG THE LEADING EDGE OF THE
WARM ADVECTION. HAVE ONLY FORECAST 20 TO 30 POPS DURING THIS PERIOD.
LOWS THURSDAY NIGHT WILL BE IN THE SINGLE DIGITS AND TEENS. HIGHS
FRIDAY WILL BE IN THE 30S WITH TEMPS LIKELY WARM ENOUGH FOR MIXED
RAIN/SNOW SHOWERS OVER SOUTHERN AREAS DURING THE AFTERNOON...IF ANY
PCPN OCCURS.
FOR FRIDAY NIGHT THROUGH SATURDAY...THE SOUTHWESTERLY FLOW WILL
INCREASE...WITH A LARGE AREA OF MOISTURE SURGING INTO THE REGION
FROM THE GULF OF MEXICO...AHEAD OF A FRONTAL BOUNDARY MOVING EAST
FROM THE MISSISSIPPI VALLEY. MAINLY RAIN IS EXPECTED AS THIS
MOISTURE AND FRONTAL BOUNDARY MOVE THROUGH THE REGION. POPS HAVE
BEEN FORECAST TO INCREASE LATE FRIDAY NIGHT...REACHING LIKELY AND
HIGH CHANCE LEVELS ON SATURDAY AND EARLY SATURDAY NIGHT. THE FRONT
WILL MOVE THROUGH EARLY SATURDAY NIGHT...WITH POPS DECREASING LATE
SATURDAY NIGHT. LOWS FRIDAY NIGHT WILL BE IN THE 20S...WITH THE LOWS
LIKELY OCCURRING EARLY. HIGHS SATURDAY WILL GENERALLY BE IN THE
40S...AND LOWS SATURDAY NIGHT IN THE UPPER 20S TO MID 30S.
THE AIRMASS BEHIND THE FRONT WILL NOT BE OF ARCTIC OR POLAR
ORIGIN...SO IT WILL REMAIN MILD ON SUNDAY WITH ONLY A SLIGHT CHANCE
OF SHOWERS. HIGHS WILL BE IN THE MID 30S TO MID 40S. DRY CONDITIONS
SUNDAY NIGHT WITH LOWS IN THE 20S TO AROUND 30.
A STRONG LOW PRESSURE SYSTEM WILL TAKE SHAPE IN THE NORTHERN PLAINS
SUNDAY NIGHT AND MONDAY. IT WILL HAVE LITTLE DIRECT IMPACT ON THE
FORECAST AREA SINCE IT WILL MOVE NORTHEAST ACROSS LAKE SUPERIOR.
HOWEVER...GULF OF MEXICO MOISTURE WILL SURGE NORTHEASTWARD ONCE
AGAIN AHEAD OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM. HAVE ONLY
FORECAST 30 POPS FOR NOW SINCE IT IS STILL 6 TO 7 DAYS OUT.
HOWEVER...IT SHOULD BE MILD ENOUGH AGAIN FOR MAINLY RAIN WITH THIS
SYSTEM AS WELL. HIGHS MONDAY WILL BE IN THE UPPER 30S AND 40S.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
A STRONG CYCLONIC FLOW OF ARCTIC AIR INTO THE REGION WILL BE THE
PRIMARY FEATURE AFFECTING THE TAF SITES DURING THE PERIOD.
VFR CONDITIONS ARE EXPECTED TO DOMINATE THE NEXT 24 HOURS FOR THE
KGFL/KPSF/KALB/KPOU TAF SITES. ALTHOUGH THERE WILL BE A STRONG LAKE
EFFECT RESPONSE OFF LAKE ONTARIO...IT SHOULD BE ORIENTED IN A WEST
TO EAST DIRECTION...WHICH WOULD KEEP IT NORTH OF THE TAF SITES.
CLOUDS TODAY AT THE TAF SITES WILL BE SCT-BKN AT 3.5-5 KFT
AGL...WITH MAINLY BKN CLOUDS AT KPSF. TONIGHT EXPECT MAINLY SCT
CLOUDS.
THE MAIN WEATHER ISSUE AFFECTING THE TAF SITES WILL BE STRONG AND
GUSTY WESTERLY WINDS IN THE CYCLONIC FLOW. SURFACE WINDS TODAY WILL
BE 16 TO 22 KTS WITH GUSTS IN THE 25-35 KT RANGE...THEN LOWER TO 10
TO 15 KTS WITH GUSTS OF 20 TO 25 KTS THIS EVENING. TONIGHT THW WINDS
WILL CONTINUE TO DECREASE TO LESS THAN 10 KTS AT KGFL/KPOU AFTER
07Z...AND AROUND 10 KTS WITH GUSTS TO 15 KTS AT KALB/KPSF.
OUTLOOK...
WEDNESDAY TO THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SATURDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...SHSN.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC PROBLEMS ARE EXPECTED OVER THE NEXT FIVE
DAYS.
FRIGID TEMPERATURES AND WINDY CONDITIONS WILL ALLOW FOR RIVER ICE TO
THICKEN THROUGH THURSDAY. TEMPERATURES ARE EXPECTED TO FINALLY
MODERATE TOWARD THE END OF THE WEEK INTO THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR CTZ001-013.
NY...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR NYZ058-063.
WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR NYZ032-033-
038>043-047>054-059>061-064>066-082>084.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST WEDNESDAY FOR NYZ032-
033.
MA...WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR MAZ001-025.
VT...WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...JPV
NEAR TERM...FRUGIS/JPV
SHORT TERM...JPV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
545 AM CST TUE JAN 7 2014
.DISCUSSION...
352 AM CST
FORECAST CONCERNS INCLUDE SLOW IMPROVEMENT IN BITTER COLD TEMPS AND
WIND CHILLS TODAY...A CHANCE OF SOME LIGHT SNOW WEDNESDAY AND AGAIN
THURSDAY MAINLY ACROSS THE SOUTHERN HALF OF THE FORECAST AREA...AND
FINALLY A MIXED PRECIP/RAIN SYSTEM FRIDAY/SATURDAY AS TEMPS CLIMB
ABOVE FREEZING.
THE DEEP MID-LEVEL TROUGH AND CORE OF COLDEST TEMPERATURES ALOFT
WHICH WERE OVER THE WESTERN GREAT LAKES REGION PER 00Z UPPER AIR
ANALYSIS HAS MOVED EAST ACROSS THE EASTERN LAKES AND UPPER OHIO
VALLEY EARLY THIS MORNING PER GOES WATER VAPOR LOOP. OF COURSE
SURFACE TEMPS OVER DEEP SNOW COVER ARE STILL QUITE COLD...THOUGH
TEMPS HAVE BECOME FAIRLY STEADY IN THE -8 TO -14 DEGREE RANGE ACROSS
THE CWA OVERNIGHT. GRADUALLY DIMINISHING WEST WINDS STILL PRODUCING
WIND CHILLS IN THE -28 TO -34 RANGE AT 3 AM...THOUGH THESE
CONDITIONS SHOULD GRADUALLY IMPROVE THIS MORNING AS WINDS DIMINISH
FURTHER WITH ARRIVAL OF WEAK SURFACE HIGH PRESSURE RIDGE FROM THE
WEST. WHILE A COUPLE OF AWOS SITES ACROSS OUR SOUTHWEST ARE JUST SHY
OF WIND CHILL WARNING CRITERIA...SEE NO ADVANTAGE IN CHANGING
HEADLINES AT THIS TIME AND WILL ALLOW DAY SHIFT TO DOWNGRADE BLOCKS
OF THE WARNING A LITTLE LATER THIS MORNING AS CONDITIONS WARRANT.
TEMPS SHOULD RISE INTO THE SINGLE DIGITS...ABOVE ZERO...DURING THE
DAY WITH WIND CHILLS RISING ABOVE EVEN ADVISORY CRITERIA BY EARLY
AFTERNOON.
UPPER FLOW PROGGED TO DE-AMPLIFY A BIT ACROSS THE CONUS TODAY WHILE
A COUPLE OF QUICK-MOVING CLIPPERS RIDE THE JET ALONG THE BAROCLINIC
ZONE FROM THE NORTHERN PLAINS TO THE OHIO VALLEY. GUIDANCE IN GOOD
AGREEMENT IN BRINGING ONE SUCH SYSTEM ACROSS THE AREA THIS
AFTERNOON...THOUGH IN A RATHER SHEARED AND MOISTURE-STARVED FASHION.
LIGHT SNOW CURRENTLY ACCOMPANYING THIS FEATURE ACROSS THE WESTERN
DAKOTAS...THOUGH SREF ENSEMBLE MEAN POPS DECREASE TO NIL AS IT THE
SYSTEM RAPIDLY MOVES INTO OUR AREA THIS AFTERNOON. DESPITE
ISENTROPIC ASCENT/WARM ADVECTION ACROSS THE ELEVATED THERMAL
GRADIENT...MODEL TIME SECTIONS INDICATE A DEARTH OF MOISTURE IN
LOWER LEVELS THIS AFTERNOON. OTHER THAN AN INCREASE IN SOME MID/HIGH
LEVEL CLOUDS...AM NOT EXPECTING PRECIP WITH THIS WAVE. BAROCLINIC
ZONE ENDS UP STRETCHED WEST-EAST FROM THE IA/MO BORDER EAST ACROSS
CENTRAL IL AND IND ON WEDNESDAY...AS ANOTHER SHORT WAVE TROUGH
(CURRENTLY OVER THE PACIFIC NORTHWEST) APPROACHES. GUIDANCE IS IN
REASONABLE AGREEMENT IN DEVELOPING A RELATIVELY NARROW BAND OF LIGHT
SNOW GENERALLY ALONG AND SOUTH OF THE I-80 CORRIDOR WITH MODEST
FRONTOGENETIC FORCING AND A LITTLE DIVERGENCE ALOFT WITH THE RIGHT
ENTRANCE REGION OF AN UPPER LEVEL JET STREAK TRANSLATING EAST FROM
THE GREAT LAKES. SNOW AMOUNTS LOOK TO BE LESS THAN AN INCH ACROSS
THE SOUTHERN COUNTIES OF THE CWA WEDNESDAY AFTERNOON. ECMWF/GFS
REMAIN IN DECENT AGREEMENT IN BRINGING A SECOND SHORT WAVE ACROSS
THE REGION THURSDAY...WITH SNOW REDEVELOPING ACROSS CENTRAL IL AND
LIFTING ACROSS MAINLY THE SOUTHEAST PART OF THE CWA. WHILE SOME
DIFFERENCES EXIST WITH VARIOUS MODELS...A BLEND OF EC/GFS/SREF QPF
OUTPUT SUGGESTS THE SOUTHERN CWA WILL AGAIN BE FAVORED FOR SOME
LIGHT ACCUMULATING SNOW OF PERHAPS 1-2 INCHES. TEMPS DURING THE
WEDNESDAY/THURSDAY PERIOD WILL BE SLOWLY MODERATING...WITH A FAIR
AMOUNT OF CONTRAST FROM NORTH-SOUTH THANKS TO PRESENCE OF THE
BAROCLINIC ZONE AND LESS CLOUD COVER TO THE NORTH.
GLOBAL GUIDANCE ALL INDICATE LONG-WAVE TROUGH UPPER TROUGH
DEVELOPMENT OVER THE WESTERN CONUS THURSDAY-FRIDAY...WHICH INDUCES
DOWNSTREAM RIDGE ACROSS THE MIDWEST AND EASTERN US. THIS WILL RESULT
IN WARMING TEMPS...THOUGH WITH A SURGE OF MOISTURE ACROSS THE REGION
FRIDAY. BASED ON THERMAL PROFILES/THICKNESS FIELDS...THE CURRENT
EXPECTATION IS THAT PRECIP WILL DEVELOP ACROSS THE AREA FRIDAY AND
COULD BEGIN AS A MIX OF LIGHT RAIN/FREEZING RAIN/SLEET...THOUGH
WOULD LIKELY CHANGE OVER TO RAIN ACROSS ALL/MOST OF THE FORECAST
AREA IN THE AFTERNOON. GUIDANCE DOES APPEAR TO BE SLOWING THE ONSET
OF THE PRECIP A LITTLE...WHICH WOULD HELP MINIMIZE THE AMOUNT OF
MIXED PRECIP WITH COLDER TEMPS IN PLACE DURING THE MORNING. BOTH
GFS/ECMWF DO PRODUCE 0.25-0.50 INCHES OF LIQUID QPF THROUGH FRIDAY
WHICH COMBINED WITH SOME MELTING OF DEEP SNOW PACK COULD LEAD TO
SOME FLOODING/HYDRO ISSUES HEADING INTO NEXT WEEKEND WITH TEMPS
WARMING TO THE UPPER 30S/AROUND 40. ECMWF DEPICTS ANOTHER ROUND OF
RAIN INTO THE AREA LATE SUNDAY...WHILE GFS TRENDS DRIER/COLDER...AS
MODELS DIFFER WITH PHASING OF NORTHERN STREAM TROUGH AND UPPER LOW
IN SOUTHERN PORTION OF LONG-WAVE BY DAYS 6-7. FOR NOW HAVE USED A
BLENDED GUIDANCE SOLUTION FOR TEMPS/PRECIP SUNDAY NIGHT-MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* WEST WINDS OCNLY GUSTING TO ARND 18KT...DIMINISHING THIS
AFTERNOON.
* VFR CIGS REDEVELOP LATE THIS MORNING...GRADUALLY LOWERING
THROUGH THE DAY BUT REMAINING VFR.
KREIN
//DISCUSSION...UPDATED 12Z...
ARCTIC AIR CONTINUES TO DOMINATE THE AREA...WITH A MODERATE
WESTERLY GRADIENT IN PLACE BETWEEN A DEEP LOW OVER ERN CANADA AND
A RIDGE OF HIGH PRESSURE THROUGH THE UPPER MISSOURI VALLEY.
DESPITE CLEAR SKIES OVERNIGHT...DO NOT EXPECT THAT THE LOWER
LEVELS WILL COMPLETELY DECOUPLE AND SOME GUSTINESS WILL PERSIST
THROUGH THE NIGHT. BY LATE TOMORROW MORNING...THE SFC RIDGE AXIS
WILL BEGIN TO PUSH ACROSS THE MIDDLE AND UPPER MISSISSIPPI
VALLEY...FURTHER DECREASING WINDS WHILE GRADUALLY BACKING TO MORE
SWLY. A WEAK UPPER LEVEL IMPULSE DROPPING OUT OF THE NRN PLAINS
SHOULD BRING SOME MID LEVEL CLOUDINESS AND AS THE LOWER LEVEL FLOW
BEGINS TO BACK A LITTLE MORE SWLY...A WEAK RETURN FLOW OF MOISTURE
SHOULD HELP LOWER CIGS...BUT EXPECT THAT ANY DEVELOPING CIGS WILL
REMAIN WELL INTO VFR LEVELS.
KREIN
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS.
KREIN
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR.
THURSDAY...CHANCE OF LIGHT SNOW AND MVFR CIGS/VIS EARLY.
FRIDAY...CHANCE OF WINTRY MIX EARLY...BECOMING RAIN. MVFR/IFR
CIGS/VIS POSSIBLE.
SATURDAY...SLIGHT CHANCE OF LIGHT RAIN AND MVFR EARLY...THEN VFR.
SUNDAY...SLIGHT CHANCE LIGHT SNOW OVERNIGHT. MVFR CIGS/VIS
POSSIBLE.
MONDAY...CHANCE OF LIGHT RAIN OR SNOW AND MVFR CIGS/VIS .
&&
.MARINE...
300 AM CST
WINDS ARE SLOWLY DIMINISHING OVER THE LAKE AS THE PRESSURE
GRADIENT GRADUALLY RELAXES. HAVE DROPPED THE GALE WARNING FOR THE
SOUTH HALF OF THE LAKE AND THE INDIANA NEARSHORE WATERS.
HOWEVER...WINDS GUSTING TO 30KT SHOULD HANG IN THROUGH MUCH OF
TODAY...KEEPING THE THREAT OF HEAVY FREEZING SPRAY GOING AS THERE
WILL BE LITTLE MODIFICATION OF THE AIRMASS. ALSO...WILL NEED TO
REPLACE THE GALE WARNING FOR THE INDIANA NEARSHORE WATERS WITH A
SMALL CRAFT ADVISORY WHILE MAINTAINING THE SMALL CRAFT ADVISORY
FOR THE ILLINOIS NEARSHORE WATERS. ALSO...WILL MAINTAIN THE GOING
HEAVY FREEZING SPRAY WARNING THROUGH THE DAY AS WELL. WINDS SHOULD
DIMINISH ENOUGH BY THIS EVENING THAT THE THREAT FOR ANY ADDITIONAL
HEAVY FREEZING SPRAY WILL SUBSIDE. BY EARLY THURSDAY THE ARCTIC
HIGH WILL MOVE EAST OF THE LAKE AND WINDS WILL INCREASINGLY BECOME
SOUTHERLY...ESPECIALLY WITH A NEW TROUGH OF LOW PRESSURE
DEVELOPING OVER THE PLAINS. WINDS SHOULD PICK UP INTO THE 30KT
RANGE FOR THURSDAY NIGHT AND FRIDAY...BUT WITH THE SOUTHERLY FLOW
DRAWING WARMER AIR NORTHWARD...THERE WILL BE NO THREAT FOR
FREEZING SPRAY...BUT A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED
BY THEN.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY.
IN...WIND CHILL WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
NOON TUESDAY.
LM...HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ261-LMZ362-LMZ364-
LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 6 PM TUESDAY.
SMALL CRAFT ADVISORY...ILLINOIS NEARSHORE WATERS UNTIL 10 AM TUESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
528 AM CST Tue Jan 7 2014
.DISCUSSION...
ISSUED 325 AM CST Tue Jan 7 2014
Arctic blast slowly edging south and temperatures expected to
begin to modify slowly this afternoon. Expansive area of high
pressure spreading over the center of the country gets interrupted
by a quick system on Wed night...and another for Friday and the
first half of the weekend. Temperatures starting to warm up enough
to have an impact on precip type. Extended differs greatly as a
wave ejects out of the southwest...but the GFS carries the system
further south and east, missing Central Illinois altogether. ECMWF
has a bit more of a southwesterly flow aloft...more amplified than
the GFS, and as a result quite a bit more qpf to wrap up the
weekend and start the next work week.
SHORT TERM...Today and tomorrow...
Finally saying goodbye to the bitterly cold temperatures as the
airmass slowly modifies behind the arctic blast. Highs today above
zero...and though very little change in the hourly temperatures
through the overnight with the lows being only a few degrees lower
than todays highs...tomorrow temps climb a bit more. Models
alternating with timing of impacts of two small features for
Wednesday/Wed night. Precip coverage and likelihood smaller with
the day time feature, focused more to the north along a weak
boundary. Better chances for precip Wed night into Thursday.
System should be dominated by snow early on, but accumulations
will remain small.
LONG TERM...Thursday through Monday...
Small accumulations generally less than an inch for Thursday will
come to an end late Thursday as the airmass dries aloft and
crystals are lost. Mixing in some freezing drizzle on the back
edge of the precip with this system. At this point, temperatures
should be climbing above zero across Central Illinois for Friday
and into the weekend. Another system moving in Friday night being
a bit more problematic with the midlevels warming and a lack of
dendrites the precip will have the potential to be more of a
wintry mix and icy. NAM significantly warmer...even at the surface
by a couple degrees resulting in more of a rain solution. So at
this point... precip on Friday before noon a bit of an issue.
After 18z, dominated by rain in ILX CWA. Friday night...timing of
cold air moving in behind the precip will also possibly change the
rain over... but the timing differences at this point put the end
of the rain prior to the arrival of the colder air. Next major
system has major differences in track and timing...another wave
rippling across the swrn portion of the conus and moving into the
Ohio River Valley. GFS is far enough south that it never impacts
the CWA. The ECMWF tracks more NE. The extended, as a result, has
a couple periods with chance pops until more consistency works
into the solutions.
&&
.AVIATION...
ISSUED 525 AM CST Tue Jan 7 2014
VFR conditions are expected today across the forecast area with
the potential for cigs to lower to MVFR cat after 00z...especially
across the north.
Arctic high pressure will continue drift away from the region
today with the latest satellite data and upstream surface
observations indicating a band of mid level clouds over parts of
north central Iowa. This cloud band is expected to drift southeast
and affect most of the TAF sites today with a weak weather system
developing over parts of southern Iowa into northern Missouri this
evening. Models indicate a weak warm front developing over northeast
Missouri with the frontal system edging slowly to the east. Along and
north of this boundary, some MVFR cigs are forecast to develop after
00z this evening which is being confirmed by the latest HRRR and
Short Range Ensemble models. As a result, will continue to lower
the cigs from 6000-8000 feet that are expected over the area later
this morning thru this afternoon, to btwn 2500-3500 feet tonight.
For now, will limit the MVFR cigs to the northern TAF sites (KPIA
and KBMI).
Surface winds will continue to back more into a southerly direction
today as the high pressure system shifts off to our southeast. Wind
speeds today will range from 10 to 15 kts. Winds will be light
south to southeast tonight with speeds less than 10 kts.
Smith
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING until Noon CST today FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
641 AM EST TUE JAN 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 417 AM EST TUE JAN 7 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOWS DEEP POLAR VORTEX
CENTERED FM NCENTRAL ONTARIO S INTO THE GRT LKS...WITH DEEP CYC NW
FLOW OF BITTERLY COLD AIR ARND SFC LO PRES IN NRN QUEBEC. H5/H7/H85
TEMPS WITHIN THE CORE OF COLDEST AIR AT 00Z EXTENDING FM NW ONTARIO
INTO MI WERE -45C/-35C/-30C. LLVL NW WINDS ARE UP TO 35-40 KTS PER
THE MQT 88D VWP UNDER THE FAIRLY TIGHT PRES GRADIENT OVER THE UPR
LKS... AND THE COMBINATION OF THE STEADY SFC WINDS AND THE BRUTAL
COLD THAT HAS DROPPED SFC TEMPS TO ARND -20F OVER THE INTERIOR W
HAVE CAUSED WIND CHILLS TO FALL AS LO AS -35F TO -45F OVER THE
ENTIRE CWA EARLY THIS MRNG. LES ALSO PERSISTS IN THE W TO NW WIND SN
BELTS OVER THE W AND NEAR LK SUP E OF PICTURED ROCKS. AN AREA OF
THICKER CLDS AND SOME SPOTTY -SN ARE SPREADING SEWD THRU NW ONTARIO
TOWARD THE UPR LKS IN ASSOCIATION WITH A SHRTWV DIGGING SSEWD IN NW
ONTARIO ON THE WRN FLANK OF THE POLAR VORTEX.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON RECORD LO TEMPS/WIND
CHILLS/LES AND GOING HEADLINES.
TDAY...AREA OF DPVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH SHRTWV
SLIDING SEWD THRU NE LK SUP THIS MRNG WL MAINTAIN DEEPER MSTR/MIXED
LYR AND AID IN MORE WDSPRD LES. THE SHSN WL BE SOMEWHAT HEAVIER OVER
THE E GIVEN LONGER FETCH/OPPORTUNITY FOR MOISTENING OVER THE E NEAR
LK SUP...WHERE SHARPENED LAND BREEZE CNVGC WL BE THE RULE AND SLGTLY
WARMER TEMPS MODIFIED BY LONGER PASSAGE OVER LK SUP WL NOT HAMPER SN
GROWTH AS SGNFTLY AS OVER THE W. FOLLOWING THE PASSAGE OF THE SHRTWV
TO THE E BY THIS AFTN...DNVA/LARGER SCALE QVECTOR DVGC WL
DOMINATE...WITH ACCOMPANYING SUBSIDENCE DRYING THE MID LVLS AND
CAUSING INVRN BASES TO SINK TO 4-5K FT. SO EXPECT LES INTENSITY TO
DIMINISH. DEPARTURE OF CORE OF COLDEST AIR/POLAR VORTEX TO THE NE
INTO QUEBEC THAT CAUSES H85 TEMPS TO RISE FM ARND -25C AT 12Z TO
CLOSER TO -20C BY 00Z WED WL ALLOW TEMPS TO RECOVER A BIT COMPARED
TO MON. IN CONCERT WITH SLACKENING PRES GRADIENT/SLOWLY DIMINISHING
WINDS...WIND CHILLS SHOULD EASE ABV WRNG THRESHOLDS THIS AFTN AND
THE MAGNITUDE OF THE BLSN IN AREAS IMPACTED BY THE LES SHOULD
SUBSIDE A BIT AS WELL. DID EXTEND THE GOING WRNG FOR A FEW HRS OVER
THE INTERIOR W HALF TO ACCOUNT FOR ADVY CRITERIA THAT WL PERSIST
THERE A BIT LONGER INTO THE AFTN.
TNGT...AS THE ARCTIC AIRMASS RETREATS FARTHER TO THE NE...THE PRES
GRADIENT/LLVL WINDS WL SLOWLY SLACKEN AND H85 TEMPS WL RISE TO ARND
-18C BY 12Z WED UNDER GENERAL SUBSIDENCE THAT WL SHARPEN AN INVRN
ARND 3-4K FT. EVEN THOUGH A SLOW WARMING WL ALLOW FOR IMPROVED SN
GROWTH...LOWERING INVRN BASE SHOULD LIMIT LES INTENSITY ESPECIALLY
OVER THE W. WL NOT EXTEND LES ADVYS BEYOND SCHEDULED EXPIRATION AT
00Z THIS EVNG GIVEN THE EXPECTED DIMINISHING SN TRENDS/WINDS THAT WL
ALSO DIMINISH THE MAGNITUDE OF THE BLSN/WIND CHILLS. ALTHOUGH H85
TEMPS WL MODERATE TNGT...SFC TEMPS MAY STILL PLUNGE SHARPLY AOB -20F
AWAY FM LK MODERATION WITH EXPECTATION THAT LARGER SCALE SUBSIDENCE
WL ALLOW FOR MOCLR SKIES IN THE PRESENCE OF LIGHTER WINDS. APRNT
TEMPS MAY REACH THE WIND CHILL ADVY CRITERIA...BUT OVERALL WINDS
SHOULD BE LIGHT ENUF TO JUSTIFY NO EXTENTION OF WIND CHILL HEADLINES
WHERE THE TEMPS FALL MORE SHARPLY AT THE MORE SHELTERED INTERIOR
LOCATIONS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 417 AM EST TUE JAN 7 2014
FOR WED/WED NIGHT...THE CWA WILL BE BETWEEN A SFC LOW MOVING E AND A
SFC HIGH MOVING IN FROM THE W. WHILE INVERSION HEIGHTS WILL
GRADUALLY LOWER THROUGH THE PERIOD...DO NOT EXPECT MUCH CHANGE IN
WNW-NW WIND LES WED AS WARMING TEMPS WILL PUT MORE OF THE LOW LEVELS
IN THE DGZ SO RATIOS WILL BE A BIT BETTER ALONG WITH A SHORTWAVE
MOVING NE OF THE CWA DURING THE AFTERNOON/EVENING WHICH WILL PROVIDE
SOME SYNOPTIC SUPPORT. THESE FACTORS WILL HELP OFFSET LOWERING
INVERSION HEIGHTS. FOR WED NIGHT...EXPECT LES TO LINGER MAINLY OVER
NE UPPER MI AS THE SFC HIGH MOVES S OF THE CWA WHILE DIMINISHING
OVERALL. DID NOT CHANGE FORECAST MUCH AS PREVIOUS FORECAST LOOKED
GOOD AND EXPECTATIONS HAVE NOT CHANGED SIGNIFICANTLY.
THU INTO EARLY SAT IS TRICKY AS A DISTURBANCE MOVES INTO THE PACIFIC
NW WED NIGHT...WITH NRN AND SRN JET STREAM INTERACTIONS CONTRIBUTING
TO THE SYSTEM STRENGTHENING OVER THE WRN CONUS. WITH THESE TYPES OF
NRN AND SRN STREAM INTERACTIONS...THE SITUATION IS ALWAYS MORE
UNCERTAIN AS MODELS HAVE TROUBLE HANDLING ENERGY ALLOCATION. AREA
WIDE SYSTEM SNOW IS A POSSIBILITY AS ENERGY LIFTS NE OUT OF THE
CENTRAL CONUS FRI INTO FRI NIGHT...BUT OVERALL CHANCES AND
DEFINITELY FINE DETAILS ARE FAR FROM CERTAIN. ONE THING MORE CERTAIN
IS THAT SW WINDS THU THROUGH FRI WILL RESULT AS THE HIGH EXITS E AND
THE TROUGH MOVES IN FROM THE W. MODELS ARE HINTING AT SW FLOW LES
OFF LAKE MICHIGAN...BUT WITH WARMING TEMPS AND THE NORMALLY TRICKY
NATURE OF LES IN THAT REGIME...WILL NOT ADD SIGNIFICANT EMPHASIS AT
THIS TIME. AHEAD OF THE TROUGH...MODELS INDICATE 850MB TEMPS
APPROACHING 0C FRI INTO EARLY SAT...WHICH WILL LEAD TO TEMPS RISING
CLOSER TO FREEZING FRI AND SAT.
SUN INTO MON ARE EVEN MORE UNCERTAIN AS MODELS INDICATE A QUICK
HITTING DISTURBANCE GENERALLY MOVING ALONG THE US/CANADIAN
BORDER...BUT DETAILS WITH THIS SYSTEM ARE FAR FROM CERTAIN...EVEN
GIVEN THE CURRENT GENERAL MODEL AGREEMENT. BEST THAT CAN BE SAID AT
THIS POINT IS THAT THERE IS POTENTIAL FOR A STRONGER SYSTEM TO MOVE
THROUGH OR NEAR THE REGION AND AT LEAST A QUICK SHOT OF WARMER TEMPS
AROUND FREEZING IS POSSIBLE. USED A GENERAL CONSENSUS OF GUIDANCE
FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 641 AM EST TUE JAN 7 2014
CMX...GUSTY WNW FLOW OF ARCTIC AIR WL BRING NEARLY CONTINUOUS
-SHSN/BLSN AND LIFR TO VLIFR CONDITIONS THIS MRNG. WITH THE PASSAGE
OF A DISTURBANCE LATER THIS MRNG...LARGER SCALE SUBSIDENCE WL BRING
ABOUT A DIMINISHING TREND IN THE SHSN. IN CONCERT WITH DIMINISHING
WINDS/BLSN ACCOMPANYING THE EASING OF THE PRES GRADIENT...THE VSBY
AT CMX WL LIKELY RISE INTO THE IFR RANGE LATER TDAY/TNGT.
IWD...WITH A VEERING OF THE LLVL WINDS BEHIND A PASSING DISTURBANCE
THIS MRNG...EXPECT LOWER LK CLDS/MVFR CIGS TO COME BACK OVER THIS
LOCATION FOR MUCH OF THE DAY. AS THE FLOW BACKS A BIT AGAIN TNGT...
THE LO CLDS ARE LIKELY TO SCT OUT AGAIN.
SAW...ALTHOUGH THERE WL BE SC THIS MRNG RELATED TO THE PASSING UPR
DISTURBANCE...DOWNSLOPE NATURE OF THE W TO NW FLOW SHOULD MAINTAIN
VFR CONDITIONS THRU THE ENTIRE FCST PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 AM EST TUE JAN 7 2014
EXPECT NW GALES TO 35-40 KTS OVER PORTIONS OF THE EASTERN AND
CENTRAL LAKE TO DIMINISH TO 30 KTS BY THIS EVENING AS THE PRES
GRADIENT OVER THE UPPER LAKES SLACKENS...SO DROPPED THE GOING GALE
WARNING AT 00Z WED. ALTHOUGH WINDS/WAVES WILL SLOWLY DIMINISH THRU
TONIGHT...THE COMBINATION OF THE ARCTIC COLD AND SUFFICIENT WAVE
ACTION WILL RESULT IN CONTINUED WIDESPREAD HEAVY FREEZING SPRAY. A
HIGH PRESSURE SYSTEM MOVING THROUGH LATE WEDNESDAY INTO WEDNESDAY
NIGHT WILL DECREASE WINDS...CAUSING HEAVY FREEZING SPRAY TO DIMINISH.
AS THE HIGH EXITS EAST WHILE LOW PRESSURE MOVES IN FROM THE WEST ON
THURSDAY AND FRIDAY...EXPECT AN INCREASE IN WARMER SW WINDS INTO
EARLY SATURDAY. THE AREA OF LOW PRESSURE WILL PASS THROUGH EARLY
SATURDAY...LEADING TO WESTERLY WINDS THROUGH THE REST OF THE DAY
SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 2 PM EST /1 PM CST/ THIS AFTERNOON FOR
MIZ002-004-005-009>011-084.
WIND CHILL WARNING UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ001-003-006-007-012>014-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
MIZ001>003-006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-263>267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265-266.
HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST WEDNESDAY FOR
LSZ243>245-249>251.
HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST THIS EVENING FOR
LSZ248.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KC
MARINE...KC
AREA FORECAST DISCUSSION
NWS BUFFALO NY
825 AM EST TUE JAN 7 2014
.SYNOPSIS...
THE DAY WILL START WITH DANGEROUSLY COLD WIND CHILLS FOR THE ENTIRE
REGION AND VERY HEAVY LAKE EFFECT SNOW EAST AND NORTHEAST OF LAKES
ERIE AND ONTARIO. EXPECT EXTREMELY LOW WIND CHILLS AGAIN TONIGHT
WITH WEAKER BUT PERSISTENT LAKE SNOW THROUGH WEDNESDAY AFTERNOON. A
WEAK AREA OF LOW PRESSURE WILL BRING A LIGHT GENERAL SNOW TO THE
REGION THURSDAY BEFORE A WARMING TREND ARRIVES AT THE END OF THE
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
...BLIZZARD WARNING FOR ERIE-GENESEE-WYOMING COUNTIES...
EAST OF LAKE ERIE...THE LAKE SNOW PLUME HAS SHOWN ONLY SLIGHT
NORTHWARD VARIATION THROUGH THE NIGHT AND MAY DRIFT A FEW MILES
SOUTH THEN RETURN NORTH A COUPLE MILES AGAIN AROUND NOON...THEN BACK
TO THE SOUTH AGAIN IN THE AFTERNOON. EXPECT A STRENGTHENING OF THE
LAKE ERIE BAND WITH SNOWFALL RATES TO INCREASE FROM ABOUT 1 INCH PER
HOUR TO ABOUT 2 INCHES PER HOUR FROM MID MORNING THROUGH EARLY
AFTERNOON. HRRR SHOWS A WEAKENING AFTER 20Z WITH INCREASING BOUNDARY
LAYER SHEAR 00Z TO 06Z.
WIND ALONG THE FLANKS OF THE LAKE SNOW BAND WILL BE GUSTY THROUGH
THE DAY AND INTO THE NIGHT. 00Z NAM12 BUFKIT SHOWS A 55KT JET AT
ABOUT 3KFT TO 5KFT WITHIN THE UNSTABLE LOWER LEVELS OF THE LAKE
PLUMES. THIS WILL MIX DOWN AS GUSTS ALONG THE FLANKS OF THE SNOW
PLUME AND PRODUCE BLIZZARD CONDITIONS WITH THE HEAVY SNOW. AREA
TEMPERATURES WILL REMAIN IN THE SINGLE NUMBERS ACROSS THE FORECAST
AREA...AND EVEN HANGING JUST BELOW ZERO ACROSS THE SOUTHERN TIER
CLOSER TO THE CORE OF THE COLDEST AIR. WILL MAINTAIN THE WIND CHILL
WARNING AS THE WIND PICK UP DURING THE DAY EVEN AS THE TEMPS CLIMB
OUT THE OVERNIGHT LOWS IN THE NEGATIVE NUMBERS.
EAST OF LAKE ONTARIO... LAKE SNOW BAND WILL BE MORE INTENSE WITH A
LONGER FETCH ALONG THE FULL LENGTH OF LAKE ONTARIO. THIS WILL FOCUS
ON THE CENTRAL TUG HILL WITH THE VERY GREATEST SNOW ACCUMULATION TO
BE AT THE TRIPLE JUNCTION OF JEFFERSON...LEWIS AND OSWEGO COUNTIES.
THE BAND WILL WANDER ONLY SLIGHTLY...A LITTLE FARTHER NORTH DURING
THE MORNING INTO SOUTHERN JEFFERSON AND CENTRAL LEWIS COUNTIES.
THERE IS ANOTHER MORE DIFFUSE BAND OVER NORTHERN OSWEGO COUNTY WHICH
WILL PROVIDE HALF INCH PER HOUR SNOW RATES.
SNOW AMOUNTS WILL BUILD STEADILY THROUGH THE DAY AND TONIGHT WITH 2
TO 3 FOOT TOTAL AMOUNTS POSSIBLE ACROSS SOUTHERN TO CENTRAL ERIE
COUNTY... BOUNDED BY A FOOT OR SO IN NORTHERNMOST CHAUTAUQUA AND
CATTARAUGUS COUNTIES ON THE CHAUTAUQUA RIDGE...AND 15 TO 18 INCH
AMOUNTS INTO WESTERN WYOMING AND GENESEE COUNTIES. THE TUG HILL WILL
MAINTAIN ITS REPUTATION OF ACCUMULATING A MORE PRODIGIOUS SNOWFALL
ON THE ORDER OF 3 TO 4 FEET...OR MORE...AS SNOWFALL RATES OF 3 TO 4
INCHES PER HOUR ARE NOT OUT OF QUESTION.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
THE BRUTALLY COLD AIR MASS WILL CONTINUE TO LINGER ACROSS THE REGION
WEDNESDAY...RESULTING IN ADDITIONAL TIME DEALING WITH FRIGID
TEMPERATURES...BITTERLY COLD WIND CHILLS AND LAKE EFFECT SNOW.
ONGOING WEST SOUTHWEST FLOW LAKE EFFECT SNOW WILL GRADUALLY WEAKEN
DURING THE DAY WEDNESDAY AND WEDNESDAY NIGHT WITH DECREASING
MOISTURE PROFILES AND LOWERING INVERSION HEIGHTS. PROBABLY LOOKING
AT ADDITIONAL AMOUNTS LIMITED TO LESS THAN 2 INCHES OFF LAKE
ERIE...BUT ADDITIONAL AMOUNTS IN THE 4 TO 8 INCHES ARE QUITE
POSSIBLE EAST OF LAKE ONTARIO. IT WILL REMAIN VERY COLD WEDNESDAY
WITH HIGHS IN THE TEENS AND WIND CHILLS ALTHOUGH LIKELY NOT HEADLINE
WORTHY STILL BELOW ZERO.
LAKE EFFECT SNOWS SHOULD WIND DOWN COMPLETELY THURSDAY AS DRIER AIR
CONTINUES TO SPREAD INTO THE AREA...WARM AIR ALOFT AND DRASTICALLY
LOWER INVERSION HEIGHTS. AIR MASS NOT NEARLY AS COLD AS MODIFICATION
CONTINUES WITH HIGHS REBOUNDING INTO THE 20S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
IT WILL BE NOTABLY WARMER DURING THIS PERIOD AS TEMPERATURES WILL
CLIMB WELL ABOVE NORMAL.
THE CHANGE TO MILDER WEATHER WILL COME AS A RESULT OF SIGNIFICANT
CHANGES IN THE WEATHER PATTERN ACROSS THE HIGH LATITUDES. FOR THE
PAST SEVERAL WEEKS...PERSISTENT RIDGING EXTENDING FROM THE WEST
COAST OF NORTH AMERICA NORTHWARDS ACROSS ALASKA TO NORTHERN SIBERIA
HAS COMBINED WITH A POLAR VORTEX OVER THE CANADIAN ARCTIC TO
ESTABLISH FREQUENT CROSS POLAR FLOWS. THIS PATTERN HAS FUNNELED
FRIGID AIR SOUTHWARDS ACROSS THE CANADIAN PRAIRIES TO THE GREAT
LAKES REGION...WHERE H925/H85 TEMPERATURES THE PAST WEEK OR TWO HAVE
DABBLED CLOSE TO HISTORICAL LOWS. WE HAVE BEEN FORTUNATE ENOUGH TO
AVOID THIS PATTERN DURING THE PAST FEW WINTERS...BUT THE CURRENT
NEUTRAL ENSO EVENT IN THE EQUATORIAL PACIFIC LENDS SUPPORT TO THIS
KIND OF HIGH AMPLITUDE FLOW.
THIS GLACIAL PATTERN WILL BREAK DOWN DURING THE COURSE OF THIS WEEK
THOUGH...AS THE TENACIOUS RIDGING DESCRIBED ABOVE WILL WEAKEN AND
ALLOW THE POLAR VORTEX TO RETROGRADE BACK ACROSS NUNAVUT AND THE
NORTHWEST TERRITORIES. THIS WILL EFFECTIVELY SHUT DOWN THE FEED OF
HYPERBOREAL AIR WHILE ENCOURAGING A STRONG PACIFIC BASED CURRENT TO
FLOOD THE LOWER 48 WITH STRIKINGLY MILDER AIR.
RIDGING OVER THE LOWER GREAT LAKES WILL AMPLIFY A BIT ON FRIDAY
WHILE STRONG HIGH PRESSURE OFF THE EAST COAST WILL CIRCULATE MILDER
AIR NORTHWARDS FROM THE OHIO VALLEY. H85 TEMPS ARE FORECAST TO CLIMB
TO AROUND 0C BY THE END OF THE DAY...AND WITH PARTIAL SUNSHINE
ANTICIPATED FOR THE AFTERNOON...THIS SHOULD SUPPORT DAYTIME HIGHS IN
THE MID TO UPPER 30S. READINGS MAY TICKLE THE 40 DEG MARK IN THE
NORMALLY WARMER GENESEE VALLEY.
A PACIFIC BASED COLD FRONT WILL MOVE ACROSS OUR REGION ON SATURDAY.
THERE IS AT LEAST A SUGGESTION BY THE ECMWF OF A WAVE ALONG THE
FRONT...AND THIS WOULD ONLY ENHANCE THE OPPORTUNITY FOR PCPN. WILL
RAISE POPS TO LIKELY AND GIVEN THE WARM FLOW (H85 TEMPS AS HIGH AS
+5C) AHEAD OF THE FRONT...THE PCPN WILL FALL IN THE FORM OF RAIN.
THE FRONT WILL EXIT ACROSS NEW ENGLAND SATURDAY NIGHT WHILE LOW
LEVEL RIDGING WILL BUILD ACROSS THE LOWER GREAT LAKES. THE SYNOPTIC
PCPN WILL CHANGE OVER TO SNOW SHOWERS AND TAPER OFF FROM WEST TO
EAST IN THE PROCESS.
FOR SUNDAY...FAIRLY STRONG RIDGING WILL PROMOTE PARTLY SUNNY SKIES
WITH TEMPERATURES ONCE AGAIN CLIMBING TO ABOVE NORMAL LEVELS. HIGHS
SUNDAY AFTERNOON ARE EXPECTED TO AVERAGE WITHIN A FEW DEGREES OF
40.
THE NEXT FRONTAL BOUNDARY WILL SAG ACROSS THE UPPER GREAT LAKES ON
MONDAY...BUT IT IS FORECAST TO BE NEARLY PARALLEL TO THE H85-7 FLOW.
FURTHERMORE...A SOUTHERN STREAM SHORTWAVE IS FORECAST TO SPIN UP A
SFC LOW ALONG THE SOUTHERN PORTIONS OF THE FRONT. THIS WOULD KEEP
OUR REGION WITHIN A RELATIVELY MILD SOUTHWEST FLOW SO THAT DAYTIME
HIGHS WILL ONCE AGAIN VISIT THE LOWER 40S.
&&
.AVIATION /14Z TUESDAY THROUGH SATURDAY/...
BLIZZARD CONDITIONS WITH LIFR AT TIMES FOR KBUF TODAY. THE LAKE SNOW
BANDS WILL IMPACT KBUF AND KART THROUGH MUCH OF THE DAY...THEN EXTEND
TO KROC WITH A LESSER IMPACT. KIAG AND KJHW SHOULD REMAIN AT OR
BETTER THAN UPPER MVFR CONDITIONS AS THE LAKE SNOW BANDS WILL VARY
LITTLE IN POSITION.
OUTLOOK...
TUESDAY NIGHT...VFR WITH CHANCE OF SNOW SHOWERS. IFR IN LAKE EFFECT SNOW
EAST OF THE LAKES. GUSTY WINDS.
WEDNESDAY...MAINLY VFR BUT IFR TO MVFR IN LAKE SNOWS EAST OF BOTH
LAKES.
THURSDAY...SNOW LIKELY WITH IFR.
FRIDAY...MAINLY VFR.
SATURDAY...MVFR WITH RAIN/SNOW LIKELY.
&&
.MARINE...
AN EXTENDED PERIOD OF WEST-SOUTHWESTERLY GALE FORCE WINDS WILL
PERSIST THROUGH TONIGHT AS THE LAKES WILL BE UNDER THE INFLUENCE OF
A TIGHT PRESSURE GRADIENT BETWEEN A DEEP AREA OF LOW PRESSURE OVER
NORTHERN QUEBEC AND STRONG HIGH PRESSURE OVER THE SOUTHERN UNITED
STATES. THE COMBINATION OF THE STRONG WINDS AND EXTREMELY COLD AIR
BUILDING ACROSS THE REGION WILL ALSO RESULT IN ENHANCED WAVE ACTION
AND HEAVY FREEZING SPRAY ON THE LAKES.
WINDS AND WAVES WILL GRADUALLY DIMINISH ON WEDNESDAY AS THE LOW
RETREATS INTO THE POLAR REGIONS AND HIGH PRESSURE GRADUALLY SLIDES
TOWARDS THE GREAT LAKES. THE GRADIENT WILL REMAIN JUST TIGHT ENOUGH
TO KEEP WAVES FROM SUBSIDING BELOW SMALL CRAFT ADVISORY LEVELS UNTIL
WEDNESDAY NIGHT/THURSDAY MORNING. HIGH PRESSURE WILL THEN PUSH INTO
THE GREAT LAKES FROM THE SOUTH...RESULTING IN RELATIVELY CALM
CONDITIONS THROUGH THE REST OF THE WORK WEEK.
&&
.HYDROLOGY...
RECENT HYDROGRAPHS AND VISUAL OBSERVATIONS INDICATE THAT ICE JAMS
FORMED DURING THE BRIEF WARM-UP LAST NIGHT ON BUFFALO...CAYUGA...
AND CAZENOVIA CREEKS IN THE BUFFALO AREA. AN ICE JAM HAS ALSO
FORMED ON THE GENESEE RIVER NEAR PORTAGEVILLE.
EVEN THOUGH ICE JAMS HAVE FORMED...TEMPERATURES DROPPING TO VERY
COLD VALUES HAVE COMPLETELY SHUT OFF RUNOFF. WITH JUST BASE FLOWS
RUNNING THROUGH THE CREEKS THE ICE JAMES WILL PROBABLY NOT PRODUCE
ANY SIGNIFICANT FLOODING. THEY WILL NEED TO BE WATCHED NEXT
WEEKEND HOWEVER WHEN TEMPERATURES WARM AGAIN AND RUNOFF BEGINS.
&&
.EQUIPMENT...
THE KBUF WSR-88D IS EXPERIENCING DEGRADED SIGNAL STRENGTH.
INTERNAL CALIBRATIONS ARE TRYING TO COMPENSATE...BUT THE RADAR IS
LIKELY READING RETURNS THAT ARE 5-8 DBZ BELOW WHAT WOULD NORMALLY
BE EXPECTED. THE RADAR WILL NEED TO BE TAKEN OUT OF SERVICE TO FIX
THE ISSUE...AND THIS WILL NOT BE DONE UNTIL A FAIR WEATHER DAY.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WIND CHILL WARNING UNTIL 6 PM EST THIS EVENING FOR NYZ001>006-
010>014-019>021-085.
BLIZZARD WARNING UNTIL 6 AM EST WEDNESDAY FOR NYZ010>012-085.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST WEDNESDAY FOR
NYZ006>008.
WIND CHILL ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ007-008.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ003-013.
LAKE EFFECT SNOW WARNING UNTIL 6 AM EST WEDNESDAY FOR NYZ019-
020.
MARINE...HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST THIS EVENING FOR
LEZ040-041.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LEZ020-040-
041.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
LOZ030.
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST WEDNESDAY FOR
LOZ042>045-062>065.
GALE WARNING UNTIL 4 AM EST WEDNESDAY FOR LOZ042>045-
062>065.
&&
$$
SYNOPSIS...WCH
NEAR TERM...WCH
SHORT TERM...TMA
LONG TERM...RSH
AVIATION...WCH
MARINE...WCH/WOOD
HYDROLOGY...HITCHCOCK
EQUIPMENT...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
719 AM EST TUE JAN 7 2014
.SYNOPSIS...
THE DAY WILL START WITH DANGEROUSLY COLD WIND CHILLS FOR THE ENTIRE
REGION AND VERY HEAVY LAKE EFFECT SNOW EAST AND NORTHEAST OF LAKES
ERIE AND ONTARIO. EXPECT EXTREMELY LOW WIND CHILLS AGAIN TONIGHT
WITH WEAKER BUT PERSISTENT LAKE SNOW THROUGH WEDNESDAY AFTERNOON. A
WEAK AREA OF LOW PRESSURE WILL BRING A LIGHT GENERAL SNOW TO THE
REGION THURSDAY BEFORE A WARMING TREND ARRIVES AT THE END OF THE
WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
...BLIZZARD WARNING FOR ERIE-GENESEE-WYOMING COUNTIES...
EAST OF LAKE ERIE...THE LAKE SNOW PLUME HAS SHOWN ONLY SLIGHT
NORTHWARD VARIATION THROUGH THE NIGHT AND MAY DRIFT A FEW MILES
SOUTH THEN RETURN NORTH A COUPLE MILES AGAIN AROUND NOON...THEN BACK
TO THE SOUTH AGAIN IN THE AFTERNOON. EXPECT A STRENGTHENING OF THE
LAKE ERIE BAND WITH SNOWFALL RATES TO INCREASE FROM ABOUT 1 INCH PER
HOUR TO ABOUT 2 INCHES PER HOUR FROM MID MORNING THROUGH EARLY
AFTERNOON. HRRR SHOWS A WEAKENING AFTER 20Z WITH INCREASING BOUNDARY
LAYER SHEAR 00Z TO 06Z.
WIND ALONG THE FLANKS OF THE LAKE SNOW BAND WILL BE GUSTY THROUGH
THE DAY AND INTO THE NIGHT. 00Z NAM12 BUFKIT SHOWS A 55KT JET AT
ABOUT 3KFT TO 5KFT WITHIN THE UNSTABLE LOWER LEVELS OF THE LAKE
PLUMES. THIS WILL MIX DOWN AS GUSTS ALONG THE FLANKS OF THE SNOW
PLUME AND PRODUCE BLIZZARD CONDITIONS WITH THE HEAVY SNOW. AREA
TEMPERATURES WILL REMAIN IN THE SINGLE NUMBERS ACROSS THE FORECAST
AREA...AND EVEN HANGING JUST BELOW ZERO ACROSS THE SOUTHERN TIER
CLOSER TO THE CORE OF THE COLDEST AIR. WILL MAINTAIN THE WIND CHILL
WARNING AS THE WIND PICK UP DURING THE DAY EVEN AS THE TEMPS CLIMB
OUT THE OVERNIGHT LOWS IN THE NEGATIVE NUMBERS.
EAST OF LAKE ONTARIO... LAKE SNOW BAND WILL BE MORE INTENSE WITH A
LONGER FETCH ALONG THE FULL LENGTH OF LAKE ONTARIO. THIS WILL FOCUS
ON THE CENTRAL TUG HILL WITH THE VERY GREATEST SNOW ACCUMULATION TO
BE AT THE TRIPLE JUNCTION OF JEFFERSON...LEWIS AND OSWEGO COUNTIES.
THE BAND WILL WANDER ONLY SLIGHTLY...A LITTLE FARTHER NORTH DURING
THE MORNING INTO SOUTHERN JEFFERSON AND CENTRAL LEWIS COUNTIES.
THERE IS ANOTHER MORE DIFFUSE BAND OVER NORTHERN OSWEGO COUNTY WHICH
WILL PROVIDE HALF INCH PER HOUR SNOW RATES.
SNOW AMOUNTS WILL BUILD STEADILY THROUGH THE DAY AND TONIGHT WITH 2
TO 3 FOOT TOTAL AMOUNTS POSSIBLE ACROSS SOUTHERN TO CENTRAL ERIE
COUNTY... BOUNDED BY A FOOT OR SO IN NORTHERNMOST CHAUTAUQUA AND
CATTARAUGUS COUNTIES ON THE CHAUTAUQUA RIDGE...AND 15 TO 18 INCH
AMOUNTS INTO WESTERN WYOMING AND GENESEE COUNTIES. THE TUG HILL WILL
MAINTAIN ITS REPUTATION OF ACCUMULATING A MORE PRODIGIOUS SNOWFALL
ON THE ORDER OF 3 TO 4 FEET...OR MORE...AS SNOWFALL RATES OF 3 TO 4
INCHES PER HOUR ARE NOT OUT OF QUESTION.
&&
.SHORT TERM /WEDNESDAY THROUGH THURSDAY NIGHT/...
THE BRUTALLY COLD AIR MASS WILL CONTINUE TO LINGER ACROSS THE REGION
WEDNESDAY...RESULTING IN ADDITIONAL TIME DEALING WITH FRIGID
TEMPERATURES...BITTERLY COLD WIND CHILLS AND LAKE EFFECT SNOW.
ONGOING WEST SOUTHWEST FLOW LAKE EFFECT SNOW WILL GRADUALLY WEAKEN
DURING THE DAY WEDNESDAY AND WEDNESDAY NIGHT WITH DECREASING
MOISTURE PROFILES AND LOWERING INVERSION HEIGHTS. PROBABLY LOOKING
AT ADDITIONAL AMOUNTS LIMITED TO LESS THAN 2 INCHES OFF LAKE
ERIE...BUT ADDITIONAL AMOUNTS IN THE 4 TO 8 INCHES ARE QUITE
POSSIBLE EAST OF LAKE ONTARIO. IT WILL REMAIN VERY COLD WEDNESDAY
WITH HIGHS IN THE TEENS AND WIND CHILLS ALTHOUGH LIKELY NOT HEADLINE
WORTHY STILL BELOW ZERO.
LAKE EFFECT SNOWS SHOULD WIND DOWN COMPLETELY THURSDAY AS DRIER AIR
CONTINUES TO SPREAD INTO THE AREA...WARM AIR ALOFT AND DRASTICALLY
LOWER INVERSION HEIGHTS. AIR MASS NOT NEARLY AS COLD AS MODIFICATION
CONTINUES WITH HIGHS REBOUNDING INTO THE 20S.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
IT WILL BE NOTABLY WARMER DURING THIS PERIOD AS TEMPERATURES WILL
CLIMB WELL ABOVE NORMAL.
THE CHANGE TO MILDER WEATHER WILL COME AS A RESULT OF SIGNIFICANT
CHANGES IN THE WEATHER PATTERN ACROSS THE HIGH LATITUDES. FOR THE
PAST SEVERAL WEEKS...PERSISTENT RIDGING EXTENDING FROM THE WEST
COAST OF NORTH AMERICA NORTHWARDS ACROSS ALASKA TO NORTHERN SIBERIA
HAS COMBINED WITH A POLAR VORTEX OVER THE CANADIAN ARCTIC TO
ESTABLISH FREQUENT CROSS POLAR FLOWS. THIS PATTERN HAS FUNNELED
FRIGID AIR SOUTHWARDS ACROSS THE CANADIAN PRAIRIES TO THE GREAT
LAKES REGION...WHERE H925/H85 TEMPERATURES THE PAST WEEK OR TWO HAVE
DABBLED CLOSE TO HISTORICAL LOWS. WE HAVE BEEN FORTUNATE ENOUGH TO
AVOID THIS PATTERN DURING THE PAST FEW WINTERS...BUT THE CURRENT
NEUTRAL ENSO EVENT IN THE EQUATORIAL PACIFIC LENDS SUPPORT TO THIS
KIND OF HIGH AMPLITUDE FLOW.
THIS GLACIAL PATTERN WILL BREAK DOWN DURING THE COURSE OF THIS WEEK
THOUGH...AS THE TENACIOUS RIDGING DESCRIBED ABOVE WILL WEAKEN AND
ALLOW THE POLAR VORTEX TO RETROGRADE BACK ACROSS NUNAVUT AND THE
NORTHWEST TERRITORIES. THIS WILL EFFECTIVELY SHUT DOWN THE FEED OF
HYPERBOREAL AIR WHILE ENCOURAGING A STRONG PACIFIC BASED CURRENT TO
FLOOD THE LOWER 48 WITH STRIKINGLY MILDER AIR.
RIDGING OVER THE LOWER GREAT LAKES WILL AMPLIFY A BIT ON FRIDAY
WHILE STRONG HIGH PRESSURE OFF THE EAST COAST WILL CIRCULATE MILDER
AIR NORTHWARDS FROM THE OHIO VALLEY. H85 TEMPS ARE FORECAST TO CLIMB
TO AROUND 0C BY THE END OF THE DAY...AND WITH PARTIAL SUNSHINE
ANTICIPATED FOR THE AFTERNOON...THIS SHOULD SUPPORT DAYTIME HIGHS IN
THE MID TO UPPER 30S. READINGS MAY TICKLE THE 40 DEG MARK IN THE
NORMALLY WARMER GENESEE VALLEY.
A PACIFIC BASED COLD FRONT WILL MOVE ACROSS OUR REGION ON SATURDAY.
THERE IS AT LEAST A SUGGESTION BY THE ECMWF OF A WAVE ALONG THE
FRONT...AND THIS WOULD ONLY ENHANCE THE OPPORTUNITY FOR PCPN. WILL
RAISE POPS TO LIKELY AND GIVEN THE WARM FLOW (H85 TEMPS AS HIGH AS
+5C) AHEAD OF THE FRONT...THE PCPN WILL FALL IN THE FORM OF RAIN.
THE FRONT WILL EXIT ACROSS NEW ENGLAND SATURDAY NIGHT WHILE LOW
LEVEL RIDGING WILL BUILD ACROSS THE LOWER GREAT LAKES. THE SYNOPTIC
PCPN WILL CHANGE OVER TO SNOW SHOWERS AND TAPER OFF FROM WEST TO
EAST IN THE PROCESS.
FOR SUNDAY...FAIRLY STRONG RIDGING WILL PROMOTE PARTLY SUNNY SKIES
WITH TEMPERATURES ONCE AGAIN CLIMBING TO ABOVE NORMAL LEVELS. HIGHS
SUNDAY AFTERNOON ARE EXPECTED TO AVERAGE WITHIN A FEW DEGREES OF
40.
THE NEXT FRONTAL BOUNDARY WILL SAG ACROSS THE UPPER GREAT LAKES ON
MONDAY...BUT IT IS FORECAST TO BE NEARLY PARALLEL TO THE H85-7 FLOW.
FURTHERMORE...A SOUTHERN STREAM SHORTWAVE IS FORECAST TO SPIN UP A
SFC LOW ALONG THE SOUTHERN PORTIONS OF THE FRONT. THIS WOULD KEEP
OUR REGION WITHIN A RELATIVELY MILD SOUTHWEST FLOW SO THAT DAYTIME
HIGHS WILL ONCE AGAIN VISIT THE LOWER 40S.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
BLIZZARD CONDITIONS WITH LIFR AT TIMES FOR KBUF TODAY. THE LAKE SNOW
BANDS WILL IMPACT KBUF AND KART THROUGH MUCH OF THE DAY...THEN EXTEND
TO KROC WITH A LESSER IMPACT. KIAG AND KJHW SHOULD REMAIN AT OR
BETTER THAN UPPER MVFR CONDITIONS AS THE LAKE SNOW BANDS WILL VARY
LITTLE IN POSITION.
OUTLOOK...
TUESDAY NIGHT...VFR WITH CHANCE OF SNOW SHOWERS. IFR IN LAKE EFFECT SNOW
EAST OF THE LAKES. GUSTY WINDS.
WEDNESDAY...MAINLY VFR BUT IFR TO MVFR IN LAKE SNOWS EAST OF BOTH
LAKES.
THURSDAY...SNOW LIKELY WITH IFR.
FRIDAY...MAINLY VFR.
SATURDAY...MVFR WITH RAIN/SNOW LIKELY.
&&
.MARINE...
AN EXTENDED PERIOD OF WEST-SOUTHWESTERLY GALE FORCE WINDS WILL
PERSIST THROUGH TONIGHT AS THE LAKES WILL BE UNDER THE INFLUENCE OF
A TIGHT PRESSURE GRADIENT BETWEEN A DEEP AREA OF LOW PRESSURE OVER
NORTHERN QUEBEC AND STRONG HIGH PRESSURE OVER THE SOUTHERN UNITED
STATES. THE COMBINATION OF THE STRONG WINDS AND EXTREMELY COLD AIR
BUILDING ACROSS THE REGION WILL ALSO RESULT IN ENHANCED WAVE ACTION
AND HEAVY FREEZING SPRAY ON THE LAKES.
WINDS AND WAVES WILL GRADUALLY DIMINISH ON WEDNESDAY AS THE LOW
RETREATS INTO THE POLAR REGIONS AND HIGH PRESSURE GRADUALLY SLIDES
TOWARDS THE GREAT LAKES. THE GRADIENT WILL REMAIN JUST TIGHT ENOUGH
TO KEEP WAVES FROM SUBSIDING BELOW SMALL CRAFT ADVISORY LEVELS UNTIL
WEDNESDAY NIGHT/THURSDAY MORNING. HIGH PRESSURE WILL THEN PUSH INTO
THE GREAT LAKES FROM THE SOUTH...RESULTING IN RELATIVELY CALM
CONDITIONS THROUGH THE REST OF THE WORK WEEK.
&&
.HYDROLOGY...
RECENT HYDROGRAPHS AND VISUAL OBSERVATIONS INDICATE THAT ICE JAMS
FORMED DURING THE BRIEF WARM-UP LAST NIGHT ON BUFFALO...CAYUGA...
AND CAZENOVIA CREEKS IN THE BUFFALO AREA. AN ICE JAM HAS ALSO
FORMED ON THE GENESEE RIVER NEAR PORTAGEVILLE.
EVEN THOUGH ICE JAMS HAVE FORMED...TEMPERATURES DROPPING TO VERY
COLD VALUES HAVE COMPLETELY SHUT OFF RUNOFF. WITH JUST BASE FLOWS
RUNNING THROUGH THE CREEKS THE ICE JAMES WILL PROBABLY NOT PRODUCE
ANY SIGNIFICANT FLOODING. THEY WILL NEED TO BE WATCHED NEXT
WEEKEND HOWEVER WHEN TEMPERATURES WARM AGAIN AND RUNOFF BEGINS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WIND CHILL WARNING UNTIL 6 PM EST THIS EVENING FOR NYZ001>006-
010>014-019>021-085.
BLIZZARD WARNING UNTIL 6 AM EST WEDNESDAY FOR NYZ010>012-085.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST WEDNESDAY FOR
NYZ006>008.
WIND CHILL ADVISORY UNTIL 6 PM EST THIS EVENING FOR NYZ007-008.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
NYZ003-013.
LAKE EFFECT SNOW WARNING UNTIL 6 AM EST WEDNESDAY FOR NYZ019-
020.
MARINE...HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST THIS EVENING FOR
LEZ040-041.
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LEZ020-040-
041.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
LOZ030.
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST WEDNESDAY FOR
LOZ042>045-062>065.
GALE WARNING UNTIL 4 AM EST WEDNESDAY FOR LOZ042>045-
062>065.
&&
$$
SYNOPSIS...WCH
NEAR TERM...WCH
SHORT TERM...TMA
LONG TERM...RSH
AVIATION...WCH
MARINE...WCH/WOOD
HYDROLOGY...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
651 AM EST TUE JAN 7 2014
.SYNOPSIS...
VERY COLD AND WINDY CONDITIONS WILL BE IN PLACE ACROSS THE NORTH
COUNTRY TODAY AND TONIGHT...WITH DANGEROUSLY LOW WIND CHILL VALUES
THIS MORNING...ESPECIALLY ACROSS NORTHERN NEW YORK. LOW-LEVEL
MOISTURE FROM THE GREAT LAKES WILL BRING VARIABLY CLOUDY CONDITIONS
AND SCATTERED SNOW SHOWER ACTIVITY. MOST OF THE SNOW SHOWER ACTIVITY
WILL BE LIGHT...BUT SOME HEAVIER LAKE EFFECT SNOW BANDS OFF LAKE
ONTARIO ARE EXPECTED TO LOCALLY AFFECT SOUTHERN PARTS OF ST.
LAWRENCE COUNTY INTO PORTIONS OF THE ADIRONDACKS STARTING THIS
AFTERNOON AND LASTING INTO WEDNESDAY MORNING. WEST WINDS WILL
GRADUALLY DIMINISH ACROSS THE REGION ON WEDNESDAY...WITH A TREND
TOWARD MODERATING TEMPERATURES STARTING THURSDAY AND THROUGH THE
UPCOMING WEEKEND. THE NEXT CHANCE FOR SIGNIFICANT PRECIPITATION
ARRIVES WITH A FRONTAL SYSTEM LATE SATURDAY INTO SATURDAY NIGHT.
AT THIS TIME...IT APPEARS PRECIPITATION WILL PREDOMINANTLY BE IN
THE FORM OF RAIN.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 647 AM EST TUESDAY...MINOR ADJUSTMENTS TO TEMPS/SKY COVER AS
WELL AS DOWNWARD ADJUSTMENT TO POPS NEXT 3-4 HOURS. PRIMARY LAKE
ONTARIO SNOW BAND REMAINS SOUTH OF ST. LAWRENCE COUNTY. AS LOW-
LEVEL WINDS GRADUALLY BACK TO WSWLY...ANTICIPATE A SLOW NWD
MOVEMENT OF THE LAKE EFFECT BAND...LIKELY REACHING OUR CWA
BETWEEN 15-18Z CONSISTENT WITH THE 06Z SOLN OF THE BTV-4KM-WRF.
PREVIOUS DISCUSSION: ONLY CHANGE TO ONGOING HEADLINES WAS TO
EXTEND THE WIND CHILL ADVISORY ACROSS THE NRN ADIRONDACKS AND ST.
LAWRENCE VALLEY THRU NOON TODAY (17Z)...BASED ON 20 BELOW READINGS
LASTING A COUPLE HOURS LONGER THAN PREVIOUSLY FORECAST ACROSS THE
LOWER ELEVATIONS. THE LAKE EFFECT SNOW ADVISORY...FOR LAKE EFFECT
REDEVELOPING NORTHWARD THIS AFTN...CONTINUES FOR SERN ST. LAWRENCE
COUNTY THRU 12Z WED.
UNUSUALLY DEEP 500MB TROUGH IS LIFTING NEWD FROM SERN ONTARIO
AND ACROSS NY EARLY THIS MORNING...WITH 500MB HEIGHT VALUES BELOW
500DM PER LATEST RUC ANALYSIS VCNTY OF LAKE ONTARIO. STRONG LOW-
LEVEL CAA CONTINUES EARLY THIS MORNING ACROSS THE NORTH COUNTRY WITH
850MB TEMPS DROPPING TO -22 TO -24C AND 1000-500MB THICKNESS
VALUES FALLING TO AROUND 490DM BY MID-MORNING. LOW-LEVEL
TRAJECTORIES FROM THE GREAT LAKES ARE RESULTING IN SOME MODERATION
OF THE AIR MASS...SO TEMPERATURES WON/T RIVAL LAST WEEK/S COLD
SNAP (WHEN HIGH TEMPS WERE BELOW ZERO ON JANUARY 2ND AND 3RD).
DESPITE THAT...LAPSE RATES ARE NEAR DRY ADIABATIC FROM THE SFC-
750MB...WHICH IS QUITE DEEP FOR JANUARY. STEEP LAPSE RATES
COMBINED WITH A STRONG WESTERLY GRADIENT FLOW BETWEEN SFC HIGH
PRESSURE OVER THE TN RIVER VALLEY AND DEEP SFC LOW PRESSURE EAST
OF HUDSON BAY WILL RESULT IN MODERATELY STRONG AND GUSTY WINDS
CONTINUING ALL AREAS THRU THE DAYLIGHT HRS TODAY. LOOKING AT WSW
SURFACE WINDS OF 15-25 MPH WITH GUSTS TO 35 MPH. THIS WILL RESULT
IN VERY LOW WIND CHILL VALUES...AND IT CONTINUES TO APPEAR THAT
WE/LL MEET WIND CHILL ADVISORY CRITERIA OF 20 BELOW ACROSS THE NRN
ADIRONDACKS AND ST. LAWRENCE VALLEY FOR A TIME THIS MORNING. WIND
CHILLS GENERALLY 5 TO 15 BELOW ACROSS VT THIS AM. DAYTIME HIGH
TEMPERATURES WILL RANGE FROM THE LOW TEENS IN THE CHAMPLAIN VALLEY
TO THE SINGLE DIGITS ACROSS THE NRN ADIRONDACKS AND MUCH OF
N-CENTRAL AND NERN VT. GENERALLY TRENDED TOWARD THE COLDER SIDE OF
MOS GUIDANCE BASED ON UPSTREAM OBSERVATIONS.
CONCERNING PRECIPITATION...IT APPEARS THAT A SECONDARY COLD FRONT
PASSES THRU AROUND 09Z WITH SOME LIGHT ADDITIONAL SNOW SHOWER
ACTIVITY. ANY ACCUMULATION ASSOCIATED WITH THE BDNRY SHOULD BE UNDER
AN INCH. VEERING WINDS BRIEFLY SHIFTS LAKE ONTARIO SNOW BAND SOUTH
OF OUR CWA THIS MORNING. HOWEVER...THE BTV 4KM AND 12KM WRF MODELS
INDICATE THE BAND WILL OSCILLATE BACK NWD WITH LAKE EFFECT SNOW
BANDS RETURNING TO SRN ST. LAWRENCE INTO SRN FRANKLIN/WRN ESSEX NY
COUNTIES BETWEEN 15Z AND 18Z. ALSO NOTING THAT 850MB FLOW IS 35 TO
40 KTS...SO BAND COULD EXTEND DOWNSTREAM A SIGNIFICANT
DISTANCE...EVEN BRINGING SOME OCCASIONAL FLURRIES OR SNOW SHOWERS
ACROSS THE CHAMPLAIN VALLEY AND UPSLOPE INTO THE CENTRAL/NRN
GREENS FROM TIME TO TIME THIS AFTN/EVE. MAIN IMPACT TO ROAD
CONDITIONS WILL BE LOCALIZED TO SRN ST. LAWRENCE CO. SNOW COULD
BE LOCALLY HEAVY AT TIMES ALONG AND SOUTH OF THE NY ROUTE 3
CORRIDOR FROM BACKUS TO CRANBERRY LAKE TO TUPPER LAKE. WILL
MAINTAIN THE LAKE EFFECT SNOW ADVISORY ACROSS SERN ST. LAWRENCE
COUNTY FOR WHERE ADDITION ACCUMULATIONS AROUND 4" ARE POSSIBLE
BETWEEN 15-00Z TODAY. SNOW-TO-LIQUID RATIOS WILL GENERALLY BE
AROUND 20:1.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH THURSDAY/...
AS OF 330 AM EST TUESDAY...LAKE EFFECT SNOW BANDS WILL CONTINUE
PERIODICALLY IMPACT SRN ST. LAWRENCE COUNTY INTO THE NRN
ADIRONDACKS THROUGH MUCH OF TONIGHT. IT APPEARS BASED ON 4 AND
12KM BTV-WRF SOLNS THAT INTENSITY OF LAKE EFFECT BANDS INTO OUR
CWA WILL LESSEN AFTER 09Z WED. THUS...THE CURRENT ENDING TIME OF
THE ADVISORY AT 12Z WED CONTINUES TO LOOK GOOD. ANTICIPATE SOME
LOCAL ACCUMULATIONS OF 6-8" BY THE TIME THE EVENT ENDS...MAINLY
ALONG AND SOUTH OF NY STATE HIGHWAY 3. ELSEHWERE ACROSS THE
FORECAST AREA...DIMINISHING COVERAGE OF ANY FLURRY ACTIVITY. WSWLY
FLOW FROM THE GREAT LAKES SUGGESTS MOSTLY CLOUDY CONDITIONS...AND
WITH WINDS REMAINING 10-15 MPH...NOT MUCH PROSPECT FOR RADIATIONAL
COOLING TONIGHT. THIS WILL KEEP LOWS GENERALLY IN THE SINGLE
DIGITS ABOVE ZERO...BUT LOCALLY 0 TO -5F ACROSS N-CENTRAL AND NERN
VT AND WITHIN THE ADIRONDACK REGION BETWEEN 1500 AND 2000 FT.
GRADIENT FLOW RELAXES A BIT ON WEDNESDAY...SO WIND CHILL VALUES
WILL BE LESS SEVERE. SOME LAKE EFFECT SNOW SHOWERS ARE STILL
POSSIBLE FOR SRN ST. LAWRENCE AND FRANKLIN COUNTIES...THOUGH
INTENSITY SHOULD BE LESS. A FEW FLURRIES POSSIBLE ELSEWHERE.
STAYED NEAR MOS CONSENSUS ON TEMPS...GENERALLY MID TO UPPER TEENS
FOR AFTN HIGHS...SO A SLIGHT MODERATION FROM EXPECTED HIGHS
TUESDAY.
DURING WEDNESDAY NIGHT...BOTH THE 00Z GFS AND NAM INDICATE THAT A
NORTHERN STREAM SHORTWAVE TROUGH WILL GRAZE THE NRN ZONES. LITTLE IN
THE WAY OF A SFC REFLECTION OR LOW-LEVEL CONVERGENCE...AND AIR MASS
REMAINS QUITE DRY WITH PW VALUES AROUND 0.1 IN. SATURATED LAYER IN
NAM MODEL SOUNDINGS 4-7 KFT LIKELY INDICATIVE OF CLOUD COVER...SO
WILL INDICATE MOSTLY CLOUDY BUT DRY CONDITIONS. LOWS WILL BE
SEASONABLY COLD AND GENERALLY IN THE SINGLE DIGITS ABOVE ZERO...AND
LOCALLY IN THE LOWER TEENS IN THE CHAMPLAIN VALLEY.
SURFACE ANTICYCLONE BUILDS DIRECTLY OVERHEAD DURING THE DAY
THURSDAY. INCREASED SUBSIDENCE DRIES OUT THE COLUMN WITH 1000-500MB
RH VALUES FALLING INTO THE 20-30 PERCENT RANGE. IT ALSO APPEARS THAT
850-700MB FLOW VEERS FROM WSW TO NWLY DURING THE DAYLIGHT HRS...SO
THERE WILL BE LESS IMPACT OF MOISTURE/CLOUDINESS FROM THE GREAT
LAKES. THUS...WILL INDICATE DIMINISHING CLOUDINESS AND MOSTLY SUNNY
FOR THURSDAY AFTN. WINDS WILL BE LIGHT W-NW DURING THE DAYLIGHT HRS
AND AFTN HIGH TEMPS SHOULD REACH THE LOW-MID 20S...AS GRADUAL AIR
MASS MODERATING COMMENCES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 330 AM EST TUESDAY...SFC HIGH PRESSURE WILL SLIDE OFF THE SRN
NEW ENGLAND COAST...BRINGING SW FLOW AND WAA OVER THE NORTH COUNTRY
THURSDAY THROUGH FRIDAY NIGHT/SATURDAY. TEMPERATURES WILL BE
NOTICEABLY WARMER WITH MAX TEMPS IN THE M20S-L30S FRIDAY...WARMING
TO THE M30S-L40S ON SATURDAY. MIN TEMPS WILL WARM FROM 0F TO 15F ON
THURSDAY NIGHT TO THE UPPER TEENS AND M20S FRIDAY NIGHT.
LATE FRIDAY NIGHT INTO SATURDAY WILL SEE AN INCREASING THREAT OF
PRECIPITATION AS AN UPPER LVL TROUGH APPROACHES FROM CENTRAL CANADA.
THIS TROUGH WILL BE ASSOCIATED WITH A SFC LOW PRESSURE SYSTEM NEAR
HUDSONS BAY WITH A FRONTAL SYSTEM DRAPING SWD THRU THE GREAT LAKES
REGION INTO THE MISSISSIPPI VALLEY. WAA AHEAD OF THE FRONT WILL
BRING ABOVE FREEZING TEMPS IN ALOFT SATURDAY MORNING...WHILE COLD
AIR IS DIFFICULT TO ERODE AT THE SFC...RESULTING IN POTENTIAL FOR
SEVERAL HRS OF FZRA. BY THE EARLY AFTN...IT LOOKS LIKE THE WARM AIR
WILL HAVE INFILTRATED THE BL...TRANSITIONING ALL PRECIP TO RAIN.
AS THE COLD FRONT MOVES W TO E ACROSS THE REGION LATE
SATURDAY/SATURDAY NT...PRECIP WILL TAPER OFF AS COLDER AIR FILTERS
IN...TRANSITIONING TO A RAIN/SNOW MIX TO ALL SNOW. LITTLE TO NO SN
FALL ACCUMULATION EXPECTED AT THIS PT AS PRECIP LOOKS TO MOSTLY END
BEFORE COLD AIR REALLY SETTLES IN. SLIGHTLY COOLER TEMPS WILL RESIDE
OVER THE NORTH COUNTRY WITH MAX TEMPS IN THE M30S-NEAR 40 AND MIN
TEMPS IN THE 20S TO NEAR 30.
ANOTHER UPPER LVL TROUGH WILL APPROACH FROM THE WEST...TO BRING MORE
PRECIP TO THE NORTH COUNTRY EARLY NEXT WEEK.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...GENERALLY VFR CONDITIONS WITH GUSTY SW-W
WINDS PERSISTING THIS MORNING. MORE LAKE EFFECT SNOW SHOWERS WILL
DEVELOP LATE THIS MORNING INTO THE AFTN AND EVENING...MAINLY
AFFECTING KSLK/KMSS WITH SOME ENHANCED OROGRAPHIC SNOW AT KMPV
AND MVFR/IFR CONDITIONS AT THESE SITES. AFTER DAYBREAK...STRONG
FLOW ALOFT WILL INCREASE WINDS WITH GUSTS IN EXCESS OF 35KTS
PSBL. KSLK AND KMPV MOST LIKELY TO BCM MVFR/IFR LATE THIS
MRONING.
HEADING INTO THE LATE AFTN/EVENING HRS...WINDS WIIL GRADUALLY
SUBSIDE TO 10-15KTS WITH GUSTS OF 15-25KTS. FETCH ACROSS LAKE
ONTARIO WILL SLOWLY SHRINK AS WINDS WEAKEN
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...
12Z WEDNESDAY THRU 00Z THURSDAY...PERSISTENT LOW-LEVEL WESTERLY
FLOW FROM THE GREAT LAKES COMBINED WITH ARCTIC AIR MASS WILL
MAINTAIN PERIODS OF MVFR/IFR CEILINGS WITH OCCASIONAL SNOW SHOWER
ACTIVITY. DUE TO LAKE EFFECT BANDS...SNOW SHOWERS WILL LIKELY BE
MOST PERSISTENT AT KSLK.
00Z THURSDAY THRU 06Z FRIDAY...CONDITIONS SHOULD GENERALLY
IMPROVE TO VFR AS HIGH PRESSURE BUILDS ACROSS THE AREA LATE
WEDNESDAY THRU THURSDAY.
06Z FRIDAY ONWARD...A WARM FRONT MOVING NEWD WILL BRING A CHANCE
OF LIGHT SNOW AND MVFR CONDITIONS THURSDAY NIGHT...FOLLOWED BY A
COLD FRONT FRIDAY NIGHT INTO SATURDAY WITH VFR/MVFR MIX IN
-RW/-SW SATURDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR NYZ026-027-
029>031-034-087.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR NYZ029.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS BURLINGTON VT
647 AM EST TUE JAN 7 2014
.SYNOPSIS...
VERY COLD AND WINDY CONDITIONS WILL BE IN PLACE ACROSS THE NORTH
COUNTRY TODAY AND TONIGHT...WITH DANGEROUSLY LOW WIND CHILL VALUES
THIS MORNING...ESPECIALLY ACROSS NORTHERN NEW YORK. LOW-LEVEL
MOISTURE FROM THE GREAT LAKES WILL BRING VARIABLY CLOUDY CONDITIONS
AND SCATTERED SNOW SHOWER ACTIVITY. MOST OF THE SNOW SHOWER ACTIVITY
WILL BE LIGHT...BUT SOME HEAVIER LAKE EFFECT SNOW BANDS OFF LAKE
ONTARIO ARE EXPECTED TO LOCALLY AFFECT SOUTHERN PARTS OF ST.
LAWRENCE COUNTY INTO PORTIONS OF THE ADIRONDACKS STARTING THIS
AFTERNOON AND LASTING INTO WEDNESDAY MORNING. WEST WINDS WILL
GRADUALLY DIMINISH ACROSS THE REGION ON WEDNESDAY...WITH A TREND
TOWARD MODERATING TEMPERATURES STARTING THURSDAY AND THROUGH THE
UPCOMING WEEKEND. THE NEXT CHANCE FOR SIGNIFICANT PRECIPITATION
ARRIVES WITH A FRONTAL SYSTEM LATE SATURDAY INTO SATURDAY NIGHT.
AT THIS TIME...IT APPEARS PRECIPITATION WILL PREDOMINANTLY BE IN
THE FORM OF RAIN.
&&
.NEAR TERM /UNTIL 7 PM THIS EVENING/...
AS OF 330 AM EST TUESDAY...ONLY CHANGE TO ONGOING HEADLINES WAS TO
EXTEND THE WIND CHILL ADVISORY ACROSS THE NRN ADIRONDACKS AND ST.
LAWRENCE VALLEY THRU NOON TODAY (17Z)...BASED ON 20 BELOW READINGS
LASTING A COUPLE HOURS LONGER THAN PREVIOUSLY FORECAST ACROSS THE
LOWER ELEVATIONS. THE LAKE EFFECT SNOW ADVISORY...FOR LAKE EFFECT
REDEVELOPING NORTHWARD THIS AFTN...CONTINUES FOR SERN ST. LAWRENCE
COUNTY THRU 12Z WED.
UNUSUALLY DEEP 500MB TROUGH IS LIFTING NEWD FROM SERN ONTARIO
AND ACROSS NY EARLY THIS MORNING...WITH 500MB HEIGHT VALUES BELOW
500DM PER LATEST RUC ANALYSIS VCNTY OF LAKE ONTARIO. STRONG LOW-
LEVEL CAA CONTINUES EARLY THIS MORNING ACROSS THE NORTH COUNTRY WITH
850MB TEMPS DROPPING TO -22 TO -24C AND 1000-500MB THICKNESS
VALUES FALLING TO AROUND 490DM BY MID-MORNING. LOW-LEVEL
TRAJECTORIES FROM THE GREAT LAKES ARE RESULTING IN SOME MODERATION
OF THE AIR MASS...SO TEMPERATURES WON/T RIVAL LAST WEEK/S COLD
SNAP (WHEN HIGH TEMPS WERE BELOW ZERO ON JANUARY 2ND AND 3RD).
DESPITE THAT...LAPSE RATES ARE NEAR DRY ADIABATIC FROM THE SFC-
750MB...WHICH IS QUITE DEEP FOR JANUARY. STEEP LAPSE RATES
COMBINED WITH A STRONG WESTERLY GRADIENT FLOW BETWEEN SFC HIGH
PRESSURE OVER THE TN RIVER VALLEY AND DEEP SFC LOW PRESSURE EAST
OF HUDSON BAY WILL RESULT IN MODERATELY STRONG AND GUSTY WINDS
CONTINUING ALL AREAS THRU THE DAYLIGHT HRS TODAY. LOOKING AT WSW
SURFACE WINDS OF 15-25 MPH WITH GUSTS TO 35 MPH. THIS WILL RESULT
IN VERY LOW WIND CHILL VALUES...AND IT CONTINUES TO APPEAR THAT
WE/LL MEET WIND CHILL ADVISORY CRITERIA OF 20 BELOW ACROSS THE NRN
ADIRONDACKS AND ST. LAWRENCE VALLEY FOR A TIME THIS MORNING. WIND
CHILLS GENERALLY 5 TO 15 BELOW ACROSS VT THIS AM. DAYTIME HIGH
TEMPERATURES WILL RANGE FROM THE LOW TEENS IN THE CHAMPLAIN VALLEY
TO THE SINGLE DIGITS ACROSS THE NRN ADIRONDACKS AND MUCH OF
N-CENTRAL AND NERN VT. GENERALLY TRENDED TOWARD THE COLDER SIDE OF
MOS GUIDANCE BASED ON UPSTREAM OBSERVATIONS.
CONCERNING PRECIPITATION...IT APPEARS THAT A SECONDARY COLD FRONT
PASSES THRU AROUND 09Z WITH SOME LIGHT ADDITIONAL SNOW SHOWER
ACTIVITY. ANY ACCUMULATION ASSOCIATED WITH THE BDNRY SHOULD BE UNDER
AN INCH. VEERING WINDS BRIEFLY SHIFTS LAKE ONTARIO SNOW BAND SOUTH
OF OUR CWA THIS MORNING. HOWEVER...THE BTV 4KM AND 12KM WRF MODELS
INDICATE THE BAND WILL OSCILLATE BACK NWD WITH LAKE EFFECT SNOW
BANDS RETURNING TO SRN ST. LAWRENCE INTO SRN FRANKLIN/WRN ESSEX NY
COUNTIES BETWEEN 15Z AND 18Z. ALSO NOTING THAT 850MB FLOW IS 35 TO
40 KTS...SO BAND COULD EXTEND DOWNSTREAM A SIGNIFICANT
DISTANCE...EVEN BRINGING SOME OCCASIONAL FLURRIES OR SNOW SHOWERS
ACROSS THE CHAMPLAIN VALLEY AND UPSLOPE INTO THE CENTRAL/NRN
GREENS FROM TIME TO TIME THIS AFTN/EVE. MAIN IMPACT TO ROAD
CONDITIONS WILL BE LOCALIZED TO SRN ST. LAWRENCE CO. SNOW COULD
BE LOCALLY HEAVY AT TIMES ALONG AND SOUTH OF THE NY ROUTE 3
CORRIDOR FROM BACKUS TO CRANBERRY LAKE TO TUPPER LAKE. WILL
MAINTAIN THE LAKE EFFECT SNOW ADVISORY ACROSS SERN ST. LAWRENCE
COUNTY FOR WHERE ADDITION ACCUMULATIONS AROUND 4" ARE POSSIBLE
BETWEEN 15-00Z TODAY. SNOW-TO-LIQUID RATIOS WILL GENERALLY BE
AROUND 20:1.
&&
.SHORT TERM /7 PM THIS EVENING THROUGH THURSDAY/...
AS OF 330 AM EST TUESDAY...LAKE EFFECT SNOW BANDS WILL CONTINUE
PERIODICALLY IMPACT SRN ST. LAWRENCE COUNTY INTO THE NRN
ADIRONDACKS THROUGH MUCH OF TONIGHT. IT APPEARS BASED ON 4 AND
12KM BTV-WRF SOLNS THAT INTENSITY OF LAKE EFFECT BANDS INTO OUR
CWA WILL LESSEN AFTER 09Z WED. THUS...THE CURRENT ENDING TIME OF
THE ADVISORY AT 12Z WED CONTINUES TO LOOK GOOD. ANTICIPATE SOME
LOCAL ACCUMULATIONS OF 6-8" BY THE TIME THE EVENT ENDS...MAINLY
ALONG AND SOUTH OF NY STATE HIGHWAY 3. ELSEHWERE ACROSS THE
FORECAST AREA...DIMINISHING COVERAGE OF ANY FLURRY ACTIVITY. WSWLY
FLOW FROM THE GREAT LAKES SUGGESTS MOSTLY CLOUDY CONDITIONS...AND
WITH WINDS REMAINING 10-15 MPH...NOT MUCH PROSPECT FOR RADIATIONAL
COOLING TONIGHT. THIS WILL KEEP LOWS GENERALLY IN THE SINGLE
DIGITS ABOVE ZERO...BUT LOCALLY 0 TO -5F ACROSS N-CENTRAL AND NERN
VT AND WITHIN THE ADIRONDACK REGION BETWEEN 1500 AND 2000 FT.
GRADIENT FLOW RELAXES A BIT ON WEDNESDAY...SO WIND CHILL VALUES
WILL BE LESS SEVERE. SOME LAKE EFFECT SNOW SHOWERS ARE STILL
POSSIBLE FOR SRN ST. LAWRENCE AND FRANKLIN COUNTIES...THOUGH
INTENSITY SHOULD BE LESS. A FEW FLURRIES POSSIBLE ELSEWHERE.
STAYED NEAR MOS CONSENSUS ON TEMPS...GENERALLY MID TO UPPER TEENS
FOR AFTN HIGHS...SO A SLIGHT MODERATION FROM EXPECTED HIGHS
TUESDAY.
DURING WEDNESDAY NIGHT...BOTH THE 00Z GFS AND NAM INDICATE THAT A
NORTHERN STREAM SHORTWAVE TROUGH WILL GRAZE THE NRN ZONES. LITTLE IN
THE WAY OF A SFC REFLECTION OR LOW-LEVEL CONVERGENCE...AND AIR MASS
REMAINS QUITE DRY WITH PW VALUES AROUND 0.1 IN. SATURATED LAYER IN
NAM MODEL SOUNDINGS 4-7 KFT LIKELY INDICATIVE OF CLOUD COVER...SO
WILL INDICATE MOSTLY CLOUDY BUT DRY CONDITIONS. LOWS WILL BE
SEASONABLY COLD AND GENERALLY IN THE SINGLE DIGITS ABOVE ZERO...AND
LOCALLY IN THE LOWER TEENS IN THE CHAMPLAIN VALLEY.
SURFACE ANTICYCLONE BUILDS DIRECTLY OVERHEAD DURING THE DAY
THURSDAY. INCREASED SUBSIDENCE DRIES OUT THE COLUMN WITH 1000-500MB
RH VALUES FALLING INTO THE 20-30 PERCENT RANGE. IT ALSO APPEARS THAT
850-700MB FLOW VEERS FROM WSW TO NWLY DURING THE DAYLIGHT HRS...SO
THERE WILL BE LESS IMPACT OF MOISTURE/CLOUDINESS FROM THE GREAT
LAKES. THUS...WILL INDICATE DIMINISHING CLOUDINESS AND MOSTLY SUNNY
FOR THURSDAY AFTN. WINDS WILL BE LIGHT W-NW DURING THE DAYLIGHT HRS
AND AFTN HIGH TEMPS SHOULD REACH THE LOW-MID 20S...AS GRADUAL AIR
MASS MODERATING COMMENCES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
AS OF 330 AM EST TUESDAY...SFC HIGH PRESSURE WILL SLIDE OFF THE SRN
NEW ENGLAND COAST...BRINGING SW FLOW AND WAA OVER THE NORTH COUNTRY
THURSDAY THROUGH FRIDAY NIGHT/SATURDAY. TEMPERATURES WILL BE
NOTICEABLY WARMER WITH MAX TEMPS IN THE M20S-L30S FRIDAY...WARMING
TO THE M30S-L40S ON SATURDAY. MIN TEMPS WILL WARM FROM 0F TO 15F ON
THURSDAY NIGHT TO THE UPPER TEENS AND M20S FRIDAY NIGHT.
LATE FRIDAY NIGHT INTO SATURDAY WILL SEE AN INCREASING THREAT OF
PRECIPITATION AS AN UPPER LVL TROUGH APPROACHES FROM CENTRAL CANADA.
THIS TROUGH WILL BE ASSOCIATED WITH A SFC LOW PRESSURE SYSTEM NEAR
HUDSONS BAY WITH A FRONTAL SYSTEM DRAPING SWD THRU THE GREAT LAKES
REGION INTO THE MISSISSIPPI VALLEY. WAA AHEAD OF THE FRONT WILL
BRING ABOVE FREEZING TEMPS IN ALOFT SATURDAY MORNING...WHILE COLD
AIR IS DIFFICULT TO ERODE AT THE SFC...RESULTING IN POTENTIAL FOR
SEVERAL HRS OF FZRA. BY THE EARLY AFTN...IT LOOKS LIKE THE WARM AIR
WILL HAVE INFILTRATED THE BL...TRANSITIONING ALL PRECIP TO RAIN.
AS THE COLD FRONT MOVES W TO E ACROSS THE REGION LATE
SATURDAY/SATURDAY NT...PRECIP WILL TAPER OFF AS COLDER AIR FILTERS
IN...TRANSITIONING TO A RAIN/SNOW MIX TO ALL SNOW. LITTLE TO NO SN
FALL ACCUMULATION EXPECTED AT THIS PT AS PRECIP LOOKS TO MOSTLY END
BEFORE COLD AIR REALLY SETTLES IN. SLIGHTLY COOLER TEMPS WILL RESIDE
OVER THE NORTH COUNTRY WITH MAX TEMPS IN THE M30S-NEAR 40 AND MIN
TEMPS IN THE 20S TO NEAR 30.
ANOTHER UPPER LVL TROUGH WILL APPROACH FROM THE WEST...TO BRING MORE
PRECIP TO THE NORTH COUNTRY EARLY NEXT WEEK.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
THROUGH 12Z WEDNESDAY...GENERALLY VFR CONDITIONS WITH GUSTY SW-W
WINDS PERSISTING THIS MORNING. MORE LAKE EFFECT SNOW SHOWERS WILL
DEVELOP LATE THIS MORNING INTO THE AFTN AND EVENING...MAINLY
AFFECTING KSLK/KMSS WITH SOME ENHANCED OROGRAPHIC SNOW AT KMPV
AND MVFR/IFR CONDITIONS AT THESE SITES. AFTER DAYBREAK...STRONG
FLOW ALOFT WILL INCREASE WINDS WITH GUSTS IN EXCESS OF 35KTS
PSBL. KSLK AND KMPV MOST LIKELY TO BCM MVFR/IFR LATE THIS
MRONING.
HEADING INTO THE LATE AFTN/EVENING HRS...WINDS WIIL GRADUALLY
SUBSIDE TO 10-15KTS WITH GUSTS OF 15-25KTS. FETCH ACROSS LAKE
ONTARIO WILL SLOWLY SHRINK AS WINDS WEAKEN
OUTLOOK 12Z WEDNESDAY THROUGH SATURDAY...
12Z WEDNESDAY THRU 00Z THURSDAY...PERSISTENT LOW-LEVEL WESTERLY
FLOW FROM THE GREAT LAKES COMBINED WITH ARCTIC AIR MASS WILL
MAINTAIN PERIODS OF MVFR/IFR CEILINGS WITH OCCASIONAL SNOW SHOWER
ACTIVITY. DUE TO LAKE EFFECT BANDS...SNOW SHOWERS WILL LIKELY BE
MOST PERSISTENT AT KSLK.
00Z THURSDAY THRU 06Z FRIDAY...CONDITIONS SHOULD GENERALLY
IMPROVE TO VFR AS HIGH PRESSURE BUILDS ACROSS THE AREA LATE
WEDNESDAY THRU THURSDAY.
06Z FRIDAY ONWARD...A WARM FRONT MOVING NEWD WILL BRING A CHANCE
OF LIGHT SNOW AND MVFR CONDITIONS THURSDAY NIGHT...FOLLOWED BY A
COLD FRONT FRIDAY NIGHT INTO SATURDAY WITH VFR/MVFR MIX IN
-RW/-SW SATURDAY.
&&
.BTV WATCHES/WARNINGS/ADVISORIES...
VT...NONE.
NY...WIND CHILL ADVISORY UNTIL NOON EST TODAY FOR NYZ026-027-
029>031-034-087.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR NYZ029.
&&
$$
SYNOPSIS...BANACOS
NEAR TERM...BANACOS
SHORT TERM...BANACOS
LONG TERM...KGM
AVIATION...KGM
AREA FORECAST DISCUSSION
NWS RALEIGH NC
631 AM EST TUE JAN 7 2014
.SYNOPSIS...ANOMALOUSLY COLD ARCTIC HIGH PRESSURE WILL SETTLE OVER
THE CAROLINAS AND VIRGINIA THROUGH WEDNESDAY. A GRADUAL WARMING
TREND WILL BEGIN ON THURSDAY AS HIGH PRESSURE MOVES OFFSHORE AND A
SOUTHERLY RETURN FLOW DEVELOPS ACROSS THE REGION.
&&
.NEAR TERM /TODAY THROUGH WEDNESDAY/...
AS OF 240 AM TUESDAY...
...POSSIBLY THE COLDEST DAY OF 2014...
THE WIND CHILL ADVISORY WILL REMAIN IN EFFECT FOR ALL OF CENTRAL NC
THROUGH NOON TODAY. ADVISORY CRITERIA HAS ALREADY BEEN MET (WIND
CHILL VALUES OF 0 TO -10F AS OF 07Z) IN MOST AREAS WEST OF HWY
1...WITH THE COASTAL PLAIN /I-95 CORRIDOR/ EXPECTED TO
MEET ADVISORY CRITERIA BY SUNRISE.
TODAY/TONIGHT: THE POLAR VORTEX (A COLD/EXPANSIVE UPPER LEVEL LOW)
CENTERED IN VICINITY OF JAMES BAY THIS MORNING WILL LIFT NORTHEAST
INTO THE CANADIAN MARITIMES THIS AFTERNOON/TONIGHT (TO A MORE
TYPICAL LOCATION NEAR BAFFIN ISLAND)...RESULTING IN SYNOPTIC
SUBSIDENCE /HEIGHT RISES ALOFT/ ACROSS THE CAROLINAS. THE STRONGEST
SYNOPTIC SUBSIDENCE AND HEIGHT RISES WILL OCCUR THIS MORNING...
REINFORCING SURFACE PRESSURE RISES ACROSS THE REGION AND PROLONGING
THE ADVECTION OF AN ANOMALOUSLY COLD (`TO BUILD A FIRE`) ARCTIC
AIRMASS INTO CENTRAL NC. FORECAST SOUNDINGS INDICATE A WELL MIXED
BOUNDARY LAYER EXTENDING UP TO 925-900 MB (2500-3500 FT AGL)...AND
THE DRY ADIABATIC METHOD WOULD SUGGEST HIGHS RANGING FROM THE UPPER
TEENS /NEAR 20F/ IN THE FAR NW PIEDMONT TO THE LOWER/MID 20S
ELSEWHERE (WARMEST SOUTH/SE). THOUGH THE ARCTIC AIRMASS WILL QUICKLY
BEGIN TO MODIFY TONIGHT...FAVORABLE RADIATIONAL COOLING CONDITIONS
WOULD SUGGEST LOWS IN THE LOWER/MID TEENS WED MORNING.
INTERESTINGLY...THE LATEST RAP FCST SOUNDINGS SHOW A POTENTIAL FOR
VERY SHALLOW INSTABILITY TO DEVELOP UNDER THE SUBSIDENCE INVERSION
THIS MORNING ACROSS PORTIONS OF THE SANDHILLS/SE COASTAL PLAIN AND
THIS AFTERNOON IN THE PIEDMONT BY VIRTUE OF STEEP LAPSE RATES
ASSOC/W SUCH A COLD LOW-LEVEL AIRMASS (-12 TO -15C AT 900 MB)...
THOUGH IT IS DIFFICULT TO BELIEVE THAT SUFFICIENT LOW-LEVEL MOISTURE
WILL BE IN PLACE FOR VERY SHALLOW CU/TCU TO DEVELOP GIVEN SUCH A DRY
AIRMASS (PER 00Z GSO RAOB) AND THAT IT IS TYPICALLY DIFFICULT FOR
ANY UPSTREAM MOISTURE TO ADVECT EAST OF THE SOUTHERN APPALACHIANS IN
THIS TYPE OF REGIME. GIVEN THAT TEMPS AT THE TOP OF THE MIXED LAYER
WILL FALL WITHIN THE ICE NUCLEATION ZONE (I.E. -12 TO -15C)...IF LOW-
LEVEL MOISTURE IS SUFFICIENT IT WOULD AT LEAST BE POSSIBLE FOR
SHALLOW CU/TCU TO DEVELOP AND PERHAPS PRODUCE A FEW FLURRIES. WITH
THE ABOVE IN MIND...FEEL THAT THE AFOREMENTIONED SCENARIO IS TOO
UNLIKELY TO WARRANT MENTION IN THE FCST AT THIS TIME AND WILL
MAINTAIN A DRY FORECAST THROUGH TONIGHT.
WEDNESDAY: HIGH PRESSURE CENTERED OVER THE REGION WED MORNING WILL
GRADUALLY SHIFT OFFSHORE WED NIGHT AS SHORTWAVE ENERGY IN ZONAL FLOW
ALOFT APPROACHES THE SOUTHERN APPALACHIANS FROM THE WEST. WITH DRY
HIGH PRESSURE OVER THE REGION DURING THE DAY...EXPECT CONTINUED
COLD/CLEAR CONDITIONS WITH HIGHS IN THE UPPER 30S (NORTH) TO LOWER
40S (SOUTH). -VINCENT
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
AS OF 221 AM TUESDAY...
EVEN WITH THE AFOREMENTIONED BITTERLY COLD AIR MASS PULLING OUT
RAPIDLY TO THE NE AND RAPIDLY RISING HEIGHTS ALOFT... THE LINGERING
SURFACE HIGH PRESSURE OVER OUR REGION SHOULD BRING ANOTHER COLD
NIGHT FOR WEDNESDAY NIGHT. MOSTLY CLEAR SKIES WITH LOWS IN THE LOWER
TO MID 20S EXPECTED WITH SOME UPPER TEENS IN THE NORMALLY COLDER
SPOTS.
MODERATION WILL CONTINUE ON THURSDAY AS THE MAIN SURFACE HIGH
PRESSURE BECOMES ESTABLISHED OVER NEW ENGLAND BUT EXTENDING INTO
NC/SC FROM THE NORTH BEFORE SHIFTING SLOWLY OFFSHORE BY FRIDAY
MORNING. AS THE HIGH PRESSURE SHIFTS EASTWARD... WAA WILL COMMENCE
ALOFT AND THIS WILL OVERRUN THE COLD STABLE NEAR SURFACE LAYER BY
LATE THURSDAY AND THURSDAY NIGHT. SOME MODELS AND ENSEMBLE MEMBERS
SPIT OUT A FEW HUNDREDTHS OF PRECIPITATION BETWEEN 06Z-12Z FRIDAY...
MAINLY OVER THE PIEDMONT. P-TYPE WITH WARMING ALOFT WOULD BE
LIQUID... BUT CONCERNS REMAIN WITH THE VERY COLD DRY SURFACE LAYER
OF SOME LIGHT GLAZE OR ICING IN THE PIEDMONT (ESPECIALLY IN THE
TRIAD REGION) LATE THURSDAY NIGHT (SIMILAR TO THE EVENT LAST
SUNDAY). THERE APPEARS TO BE SIGNIFICANT EVAPORATIONAL COOLING
POTENTIAL THURSDAY NIGHT THAT IF ENOUGH LIGHT RAIN FALLS... TEMPS
WOULD COOL RAPIDLY TO NEAR 30 IN THE TRIAD. CURRENT SURFACE WET BULB
FORECASTS INDICATE THIS POTENTIAL... WITH LESSER CHANCES OF ANY
ICING AT RDU... TO NIL IN THE FAY/GSB/RWI AREAS OF THE WARMER
SANDHILLS AND COASTAL PLAIN. CURRENT POP IS 50 OR LESS... OR LESS
THAN LIKELY... WITH QPF OF A FEW HUNDREDTHS IF IT MATERIALIZES.
FOR NOW... WE WILL ADD MENTION OF LIGHT RAIN POSSIBLY MIXED WITH
FREEZING RAIN EARLY (IN THE TRIAD ZONES ONLY)... WITH A CHANCE OF
LIGHT RAIN ELSEWHERE. LOWS 30-38 NW TO SE. IN ADDITION... MOST
GUIDANCE INDICATES THAT TEMPERATURES PRECEDING THIS POTENTIAL LIGHT
QPF EVENT THE DAY BEFORE (THURSDAY) WILL WARM INTO THE 40S AS
CLOUDINESS GRADUALLY INCREASES ESPECIALLY IN THE AFTERNOON. WE WILL
UNDERCUT MOS GUIDANCE BY ABOUT 5 DEGREES TO TAKE INTO ACCOUNT THE
LINGERING ANOMALOUSLY SURFACE LAYER WITH CLOUDS INCREASING A TOP THE
LAYER. HIGHS SHOULD TOP OUT IN THE UPPER 30S NW TO UPPER 40S
FAYETTEVILLE TO GOLDSBORO.
&&
.LONG TERM /FRIDAY THROUGH MONDAY/...
AS OF 250 AM TUESDAY...
ANY LIGHT GLAZING EARLY FRIDAY IN THE NW PIEDMONT SHOULD BE VERY
SHORT LIVED AS WARMING ALOFT OVERWHELMS THE COLUMN... EVEN IN THE
DAMMING REGION... EVEN IF THE WARMING IS SUBTLE AT THE SURFACE. THE
HYBRID CAD SHOULD LOCK IN OVER THE NORTHWEST PIEDMONT AND DEPENDING
ON THE QPF AND LIGHT RAIN COVERAGE... TEMPS MAY STRUGGLE TO REACH 40
AT WINSTON AND GREENSBORO. TO THE SE... A WARMER... WETTER AIR MASS
WILL SPREAD IN FROM THE OCEAN. THIS WILL SET UP A LARGE TEMPERATURE
GRADIENT FRIDAY WITH THE NW EXPERIENCING 40... AND THE SE
POTENTIALLY WARMING TO NEAR 60. AREAS OF LIGHT RAIN... DRIZZLE AND
FOG SHOULD LINGER MUCH OF THE DAY OVER THE PIEDMONT.
THE FORECAST FOR SATURDAY IF FOR THE HYBRID CAD TO EVENTUALLY
BREAK... AS A WARM FRONT SHIFTS NORTH INTO VA. THIS SHOULD ALLOW
MANY AREAS IN THE EAST TO REACH INTO THE 60S WITH LOWER TO MID 50S
CONFINED TO THE NW PIEDMONT. SKIES MAY REMAIN CLOUDY IN THE NW...
BUT BECOME PARTLY SUNNY IN THE EAST.
SUNDAY INTO EARLY NEXT WEEK BRINGS PLENTY OF UNCERTAINTY WITH THE
FORECAST OF A WET SUBTROPICAL LOW LIKELY BRINGING BACK RAIN CHANCES.
THE CURRENT OPERATIONAL MODELS ARE HAVING DIFFICULTY WITH THE WAVE
TRAIN OF PACIFIC SYSTEMS AND THE POTENTIAL BRIEF CUT OFF LOW OVER
THE SOUTHERN STATES DURING THIS TIME FRAME. REGARDLESS... ABOVE
AVERAGE HEIGHTS GUARANTEES WARMER THAN NORMAL TEMPERATURES INTO
EARLY TO THE MIDDLE OF NEXT WEEK. LOWS IN THE 40S AND POSSIBLY SOME
50S... WITH HIGHS IN THE 60S EXCEPT SOME 50S NW. UNTIL THE MODELS
RESOLVE THE SYSTEM ISSUES... WE WILL KEEP LOW CHANCE OF RAIN IN
SUNDAY THROUGH MONDAY.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
AS OF 630 AM TUESDAY...
24-HR TAF PERIOD: VFR CONDITIONS WILL RULE THROUGH THE ENTIRE TAF
PERIOD IN ASSOCIATION WITH A VERY COLD/DRY ARCTIC AIRMASS ADVECTING
INTO THE REGION. EXPECT WNW WINDS SUSTAINED AT 7-12 KT WITH GUSTS AS
HIGH AS 20 KT THIS MORNING...EVENTUALLY BECOMING WESTERLY AND
DECREASING TO 5-8 KT BY MID TO LATE AFTERNOON AS THE MSLP GRADIENT
WEAKENS...THEN CALM BY OR SHORTLY AFTER SUNSET AS HIGH PRESSURE
BUILDS OVER THE REGION.
LOOKING AHEAD: VFR CONDITIONS ASSOC/W ARCTIC HIGH PRESSURE WILL
PREVAIL THROUGH WED. SUB-VFR CONDITIONS WILL BE POSSIBLE AT ALL
TERMINALS BY LATE THU/THU NIGHT AND INCREASINGLY LIKELY FRI-SUN AS
HIGH PRESSURE MOVES OFFSHORE...A SOUTHERLY RETURN FLOW DEVELOPS...
AND AN UPPER LEVEL TROUGH SLOWLY APPROACHES FROM THE WEST. -VINCENT
&&
.CLIMATE...
RECORD LOW TEMPERATURES FOR JANUARY 7TH...
RDU 15 1988
GSO 14 1988
FAY 13 1959
RECORD LOW MAXIMUM TEMPERATURES FOR JANUARY 7TH...
RDU 21 1988
GSO 21 1988
FAY 31 1988
RECORD LOW TEMPERATURES FOR JANUARY 8TH...
RDU 7 1970
GSO 6 1970
FAY 14 1970
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 AM TO NOON EST TUESDAY FOR NCZ011-
027-028-042-043-077-078-085-086-088-089.
WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST TUESDAY
FOR NCZ007>010-021>026-038>041-073>076-083-084.
&&
$$
SYNOPSIS...VINCENT
NEAR TERM...VINCENT
SHORT TERM...BADGETT
LONG TERM...BADGETT
AVIATION...VINCENT
CLIMATE...BADGETT
AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
146 PM PST TUE JAN 7 2014
.DISCUSSION...AS OF 01:27 PM PST TUESDAY...WEAK MID/UPPER LEVEL
DISTURBANCE PUSHING INTO THE PACIFIC NORTHWEST THIS AFTERNOON
WHILE FURTHER SOUTH MID/UPPER LEVEL CLOUDS CONTINUE TO STREAM
ACROSS THE CENTRAL COAST. ACROSS THE BAY AREA...AN INCREASE IN
LOWER LEVEL CLOUDS (BETWEEN 3-5KFT) CONTINUES TO MOVE INLAND AS
WELL. THIS HAS KEPT TEMPERATURES DOWN ACROSS THE REGION THIS
AFTERNOON WITH A GENERALLY PERSISTENT ONSHORE FLOW.
FORECAST MODELS CONTINUE TO INDICATE A STRONGER SYSTEM WILL SWEEP
THROUGH THE PACIFIC NORTHWEST WEDNESDAY NIGHT INTO THURSDAY. THIS
WOULD BRING A WEAK BOUNDARY THROUGH THE REGION AND A SLIGHT CHANCE
OF PRECIPITATION TO THE NORTH BAY THURSDAY MORNING. ONLY EXPECTING
VERY LIGHT PRECIPITATION IF IT DOES OCCUR ACROSS THAT REGION. A
RIDGE BUILDS BACK BEHIND THE EXITING SYSTEM AND WILL KEEP DRY
CONDITIONS ACROSS ALL OF THE REGION THURSDAY NIGHT THROUGH FRIDAY
NIGHT. ANOTHER TROUGH WILL SWEEP THROUGH THE REGION ON SATURDAY
AND BRING ANOTHER SLIGHT CHANCE FOR PRECIPITATION TO THE BAY AREA.
FURTHER SOUTH...WILL KEEP THE FORECAST DRY AT THIS TIME WITH THE
BEST MOISTURE AND SUPPORT SAYING TO THE NORTH. OVERALL...THE
AMOUNT OF RAINFALL LOOKS TO REMAIN BELOW ONE-TENTH OF AN INCH WITH
THE SYSTEM ON SATURDAY. COOLER AFTERNOON TEMPERATURES CAN BE
EXPECTED AS THESE WEAK SYSTEMS IMPACT THE REGION WEDNESDAY AND
AGAIN ON THURSDAY.
THE MID/UPPER LEVEL RIDGE WILL THEN REBUILD ACROSS MUCH OF THE
WEST COAST SUNDAY INTO AT LEAST THE MIDDLE OF NEXT WEEK. THIS WILL
PROVIDE ANOTHER WARMING TREND AND ONGOING DRY CONDITIONS ACROSS
THE REGION. WEAK OFFSHORE FLOW LOOKS POSSIBLE LATE IN THE PERIOD
WITH TEMPERATURES EVEN NEAR THE MONTEREY BAY APPROACHING THE LOWER
70S.
&&
.AVIATION...AS OF 9:40 AM PST TUESDAY...VFR CONDITIONS WILL
PREVAIL THROUGH AT LEAST THE AFTERNOON HOURS. MEDIUM TO LOW
CONFIDENCE. MID LEVEL CLOUDS CONTINUE TO STREAM ONSHORE TO THE
NORTH OF THE AREA...WITH THE SHORT TERM FORECAST MODELS INDICATING
THAT THESE CLOUDS WILL IMPACT THE TERMINALS DURING THE LATER
AFTERNOON HOURS. THE NAM...WRF...AND HRRR ALL ARE IN GOOD
AGREEMENT THAT MARINE LOW CLOUDS WILL MOVE ONSHORE BETWEEN 03 AND
06Z WEDNESDAY AS ONSHORE FLOW INCREASES.
VICINITY OF KSFO...VFR CONDITIONS WILL PREVAIL THROUGH 06Z. LOW
CONFIDENCE. LIGHT ONSHORE FLOW THIS AFTERNOON WITH POSSIBLE MVFR
CIGS AROUND 1500 FEET IMPACTING THE TERMINALS AFTER 06Z. AGAIN LOW
CONFIDENCE WITH TIMING.
KSFO BRIDGE APPROACH...THE APPROACH MAY BE IMPACTED AN HOUR LATER THAN
THE TERMINAL.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WILL PREVAIL THROUGH
22Z. MVFR CIGS WILL BE POSSIBLE LATER THIS AFTERNOON WITH IFR CIGS
THIS EVENING THROUGH THE OVERNIGHT HOURS.
$$
.MTR WATCHES/WARNINGS/ADVISORIES...
.TNGT...NONE.
&&
$$
PUBLIC FORECAST: RGASS
AVIATION: RILEY
CLIMATE: BELL/RWW
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AREA FORECAST DISCUSSION
NWS SAN FRANCISCO BAY AREA
944 AM PST TUE JAN 7 2014
.DISCUSSION...AS OF 09:25 AM PST TUESDAY...HAVE MADE A FEW UPDATES
TO THE FORECAST THIS MORNING TO MAINLY INCREASE CLOUD COVER
ACROSS MUCH OF THE REGION AND LOWER AFTERNOON TEMPERATURES BY A
DEGREE OR SO...MAINLY INLAND. MID LEVEL CLOUDS CAN BE SEEN ON VIS
SAT ACROSS THE NORTHERN CALIFORNIA COAST AS THE HIGH CLOUDS
CONTINUE TO SHIFT SOUTHEASTWARD. EXPECTING THESE CLOUDS TO IMPACT
THE REGION LATE THIS AFTERNOON OR EARLY EVENING AS WELL. WILL TAKE
A LOOK AT THE LATEST FORECAST MODELS WITH REGARDS TO THE REMAINDER
OF THE FORECAST PERIOD FOR THE AFTERNOON FORECAST PACKAGE.
&&
.PREV DISCUSSION...AS OF 3:00 AM PST TUESDAY...FAIR AMOUNT OF HIGH
LEVEL CLOUDS ACROSS OUR CWA THIS MORNING AS A VERY WEAK SYSTEM
APPROACHES THE CALIFORNIA COAST. AT THE SAME TIME THE FLOW AT THE
SURFACE HAS SWITCHED TO MORE ONSHORE AND WE ARE EVEN SEEING A FEW
REPORTS OF PATCHY FOG AROUND THE MONTEREY BAY/SALINAS VALLEY
REGION. TEMPERATURES ARE RUNNING FAIRLY CLOSE TO WHERE WE WERE 24
HOURS AGO, ALTHOUGH WITH DEW POINTS HIGHER, A FAIR NUMBER OF SPOTS
ARE AT LEAST 1-3 DEGREES WARMER. AFTER HITTING 30S AND 40S THIS
MORNING, LOOK FOR CONDITIONS SIMILAR TO MONDAY ALTHOUGH A MORE
WESTERLY FLOW AT THE SURFACE WILL HELP TO KEEP SPOTS AT THE COAST
A BIT COOLER. LOOK FOR UPPER 50S TO MID 60S AT THE COAST WITH 60S
TO LOWER 70S INLAND. CONDITIONS ON WEDNESDAY WILL BE SIMILAR TO
TODAY ALTHOUGH A FEW DEGREES COOLER AS 850 MB TEMPS DROP ANOTHER 1-2C.
BY WEDNESDAY EVENING A SYSTEM WILL DIVE DOWN FROM THE NW AND
APPROACH NEVADA BY THE AFTERNOON. THE BULK OF THE MOISTURE WILL BE
DIVERTED WELL TO OUR NORTH AND EAST, HOWEVER FAR SOUTHERN EXTENT
OF MOISTURE COULD END UP BRUSHING OUR CWA. ABOUT 15 PERCENT OF
ENSEMBLE MEMBERS BRING RAIN DOWN AS FAR SOUTH AS SFO, SO KEPT A
MENTION OF RAIN GOING FOR PARTS OF OUR AREA. ANY AMOUNTS THAT DO
FALL WILL BE VERY LIGHT.
HIGH PRESSURE WILL BRIEFLY BUILD BACK IN AS THE SYSTEM DEPARTS FOR
NORTHERN MEXICO/TEXAS REGION. ANOTHER SHORTWAVE TROF WILL THEN
ADVANCE TO THE PACNW/NORCAL COAST FOR SATURDAY. THIS ONE HAS A
BETTER SHOT THAN THE ONE ON THURSDAY AS ITS TRAJECTORY IS MORE
FROM THE NW AND NOT SIMPLY AN INSIDE SLIDER FROM THE NORTH. ABOUT
40% OF ENSEMBLE MEMBERS BRING RAIN INTO THE CWA SO POPS WERE
SLIGHTLY EXPANDED AND INCREASED. AGAIN, IF ANY RAIN FALLS, IT
SHOULD BE VERY LIGHT. A TENTH LOOKS LIKE THE UPPER END OF THE
RANGE EVEN FOR LOCATIONS SUCH AS VENADO. WOULD NOT BE SURPRISED IF
SPOTS SUCH AS SAN FRANCISCO AND HALF MOON BAY EVEN SAW A FEW TIPS
OF THE BUCKET.
JUST AS QUICKLY AS OUR RAIN CHANCES COME, THEY WILL COME TO AN END
AS THE EASTPAC/WEST COAST RIDGE REBUILDS MUCH STRONGER AND DIVERTS
ALL RAINFALL WELL TO OUR NORTH. IN FACT, MOST OF NEXT WORK WEEK
LOOKS DRY ALL OF THE WAY THROUGH THE STATE OF OREGON AND MUCH OF
WASHINGTON.
WORTH NOTING THAT THE LONG RANGE (16 DAY) OPERATIONAL GFS IS
SHOWING MORE SUBSTANTIAL RAINFALL AFTER THE 20TH OF JANUARY. 0Z
RUN INDICATES MORE THAN 2" POSSIBLE WITH THE 06Z INDICATING HALF
THAT VALUE.
&&
.CLIMATE...SAN FRANCISCO HAS REPORTED MEASURABLE RAINFALL ONLY 6
DAYS SO FAR FOR THE WATER YEAR (GOING BACK TO JULY 1, 2013). THAT TIES
THE RECORD FOR FEWEST NUMBER OF DATES.
WITH JUST 1.30" OF RAIN SO FAR FOR THE CURRENT WATER YEAR, SANTA
CRUZ IS HAVING ITS DRIEST START ON RECORD. IN A TYPICAL YEAR,
12.55" WOULD ALREADY BE RECORDED.
ON AN AVERAGE JANUARY DAY, MONTEREY WOULD RECEIVE 0.14" OF RAIN,
BEN LOMOND 0.32", HALF MOON BAY 0.18", AND 0.27" IN CLOVERDALE.
FROM THE PREVIOUS SHIFT...ROSSBY WAVE THEORY SUGGESTS WHEN A
STRONG RIDGE IS IN PLACE OVER THE WEST COAST AN EQUALLY STRONG
TROUGH WILL BE IN PLACE OVER THE EASTERN HALF OF AMERICA. THUS
WHILE THE BAY AREA AND MOST OF CALIFORNIA HAVE SEEN A WARM AND
MILD JANUARY MUCH OF THE EAST COAST HAS BEEN BRUTALLY COLD AND
SNOWY. RELIABLE CLIMATE DATA RECORDS IN DOWNTOWN SAN FRANCISCO GO
ALL THE WAY BACK TO 1850 WHILE MADISON WISCONSIN HAS CLIMATE
RECORDS BACK TO 1871. ON JANUARY 6TH 1887 DOWNTOWN SAN FRANCISCO
SET A RECORD HIGH OF 73 DEGREES THAT STILL STANDS TODAY WHILE ON
JANUARY 7TH 1887 MADISON WISCONSIN FELL TO -29 DEGREES WHICH STILL
REMAINS A RECORD LOW. IN JANUARY OF 1887 DOWNTOWN SF RECEIVED 1.90
INCHES OF RAIN WITH NEARLY ALL OF IT FALLING IN A TWO DAY WINDOW
FROM JANUARY 18-19. LITTLE OR NO RAIN FELL THE REST OF THE MONTH.
SO WHAT HAPPENED IN FEBRUARY OF 1887 IN DOWNTOWN SF? 9.24 INCHES
OF RAIN FELL (ALONG WITH 3.7 INCHES OF SNOW ON FEB 5TH). NOT HARD
SCIENCE HERE FOLKS BUT STILL HOPE AS MANY OF OUR READERS ARE
ACHING FOR RAIN AND MOUNTAIN SNOW.
&&
.AVIATION...AS OF 9:40 AM PST TUESDAY...VFR CONDITIONS WILL
PREVAIL THROUGH AT LEAST THE AFTERNOON HOURS. MEDIUM TO LOW
CONFIDENCE. MID LEVEL CLOUDS CONTINUE TO STREAM ONSHORE TO THE
NORTH OF THE AREA...WITH THE SHORT TERM FORECAST MODELS INDICATING
THAT THESE CLOUDS WILL IMPACT THE TERMINALS DURING THE LATER
AFTERNOON HOURS. THE NAM...WRF...AND HRRR ALL ARE IN GOOD
AGREEMENT THAT MARINE LOW CLOUDS WILL MOVE ONSHORE BETWEEN 03 AND
06Z WEDNESDAY AS ONSHORE FLOW INCREASES.
VICINITY OF KSFO...VFR CONDITIONS WILL PREVAIL THROUGH 06Z. LOW
CONFIDENCE. LIGHT ONSHORE FLOW THIS AFTERNOON WITH POSSIBLE MVFR
CIGS AROUND 1500 FEET IMPACTING THE TERMINALS AFTER 06Z. AGAIN LOW
CONFIDENCE WITH TIMING.
KSFO BRIDGE APPROACH...THE APPROACH MAY BE IMPACTED AN HOUR LATER THAN
THE TERMINAL.
MONTEREY BAY AREA TERMINALS...VFR CONDITIONS WILL PREVAIL THROUGH
22Z. MVFR CIGS WILL BE POSSIBLE LATER THIS AFTERNOON WITH IFR CIGS
THIS EVENING THROUGH THE OVERNIGHT HOURS.
$$
.MTR WATCHES/WARNINGS/ADVISORIES...
.TDAY...NONE.
&&
$$
PUBLIC FORECAST: RGASS
AVIATION: RILEY
CLIMATE: BELL/RWW
VISIT US AT WWW.WEATHER.GOV/SANFRANCISCO
FOLLOW US ON FACEBOOK, TWITTER, AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.SANFRANCISCOBAYAREA.GOV
WWW.TWITTER.COM/NWSBAYAREA
WWW.YOUTUBE.COM/NWSBAYAREA
AREA FORECAST DISCUSSION
NWS ALBANY NY
1235 PM EST TUE JAN 7 2014
.SYNOPSIS...
A BROAD CYCLONIC FLOW OF FRIGID ARCTIC AIR WILL CONTINUE OVER THE
REGION THROUGH THE MIDDLE OF THE WEEK...WITH DANGEROUSLY COLD WIND
CHILLS AND BITTERLY COLD TEMPERATURES. PERSISTENT WESTERLY WINDS
WILL BRING SIGNIFICANT LAKE EFFECT SNOW DOWNWIND OF LAKE ONTARIO
INTO THE WESTERN ADIRONDACKS. A MODERATING TREND IS EXPECTED TOWARDS
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF NOON EST...TEMPERATURES REMAIN IN THE SINGLE DIGITS OVER
MUCH OF THE REGION. PERSISTENT AND GUSTY WESTERLY WINDS MAKING IT
FEEL EVEN COLDER...WITH WIND CHILLS GENERALLY IN THE -10 TO -25
DEGREE RANGE.
WIND CHILL WARNINGS REMAIN IN EFFECT FOR THE EASTERN
CATSKILLS...WITH WIND CHILL ADVISORIES FOR THE REST OF THE AREA.
TEMPERATURES WILL NOT MOVE MUCH TODAY...WITH HIGHS ONLY REACHING
AROUND 10 IN THE HUDSON VALLEY...WITH SINGLE DIGITS OVER THE
HIGHER TERRAIN. AGAIN...WIND CHILLS WILL MAKE IT FEEL EVEN COLDER
THROUGHOUT THE DAY. WITH A STRONG PRESSURE GRADIENT REMAINING OVER
THE REGION...WESTERLY WINDS WILL CONTINUE AT 20 TO 30 MPH...WITH
GUSTS OF 40 TO 45 MPH EXPECTED ESPECIALLY IN FAVORED WEST-EAST
ORIENTED VALLEYS AND HIGHER TERRAIN AREAS.
THE OTHER MAIN STORY TODAY WILL BE HEAVY LAKE EFFECT SNOW FOR
PORTIONS OF THE WESTERN ADIRONDACKS...ESPECIALLY NORTHERN HERKIMER
AND NORTHWEST HAMILTON COUNTIES. OVER THE LAST FEW HOURS...THE
BAND HAS SHIFTED NORTH INTO EXTREME NORTHERN HERKIMER COUNTY. THE
SNOW BAND IS NOW NORTH OF OLD FORGE AND STILLWATER
RESERVOIR...AFFECTING THE DEEP WOODS OF THE NORTHWESTERN CORNER OF
THE ADIRONDACK PARK. THE 12Z RUN OF LOCAL HIRESWRF AND THE LATEST
12Z RUN OF THE 3KM HRRR ALL SUGGEST THE BAND TO SLOWLY MOVE AND
SHIFT DURING THE DAY. EVENTUALLY...IT WILL BEGIN TO SHIFT BACK
SOUTH TOWARDS THE OLD FORGE AREA BY LATER THIS AFTERNOON AND INTO
THE EVENING.
WE ARE STILL CONFIDENT FOR THE SNOW BAND TO EXTEND THROUGH
NORTHERN HERKIMER AND INTO WESTERN HAMILTON COUNTY TODAY AS A
MULTI-LAKE CONNECTION FROM LAKE HURON EVENTUALLY OCCURS. LOCAL
CSTAR RESEARCH INDICATES WITHIN AN EXTREME LAKE-AIR INSTABILITY
REGIME SUCH AS THIS ONE...THE INLAND EXTENT WILL BE RATHER LIMITED
UNTIL A MULTI- LAKE CONNECTION IS ESTABLISHED. WE CUT BACK
SLIGHTLY ON THE AREAL COVERAGE OF THE HEAVIEST ACCUMULATIONS BUT
ARE STILL EXPECTING 12 TO 30 INCHES IN THE MOST PERSISTENT BANDS
MAINLY FROM AROUND OLD FORGE AND ALONG ROUTE 28 NORTHWARD. THE
HEAVIEST ACCUMULATIONS OF NEAR 30 INCHES WILL PROBABLY WIND UP
OCCURRING SOMEWHERE IN THE FOREST BETWEEN STILLWATER RESERVOIR AND
THE ST. LAWRENCE COUNTY BORDER.
OUTSIDE OF THE INTENSE LAKE EFFECT SNOW OVER THE WESTERN
ADIRONDACKS...ONLY SOME LIGHT SNOW SHOWERS ARE EXPECTED FOR LIMITED
AREAS OF THE SOUTHERN GREEN MOUNTAINS IN VERMONT. SKIES WILL BE
MOSTLY TO PARTLY SUNNY ACROSS THE REMAINDER OF THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS WILL CONTINUE THROUGH
TONIGHT AND INTO WEDNESDAY MORNING. A WESTERLY BREEZE WILL PERSIST
DURING THE TIME...WITH TEMPERATURES EXPECTED TO BE IN THE SINGLE
DIGITS TO BELOW ZERO. THUS WILL CONTINUE ALL WIND CHILL HEADLINES
THROUGH 10 AM WEDNESDAY. TEMPERATURES ON WEDNESDAY WILL STILL BE
WELL BELOW NORMAL...ALTHOUGH MID TO UPPER TEENS ARE EXPECTED FOR
HIGHS RATHER THAN SINGLE DIGITS.
IT WILL BE DRY ACROSS MUCH OF THE AREA...ALTHOUGH HEAVY LAKE EFFECT
SNOW SHOULD CONTINUE ACROSS THE WESTERN ADIRONDACKS...AGAIN WITH THE
MOST PERSISTENT AND HIGHEST ACCUMULATIONS MAINLY FROM OLD FORGE AND
ROUTE 28 NORTHWARD TONIGHT INTO WEDNESDAY MORNING. LOCAL INLAND
EXTENT TOOL FROM CSTAR RESEARCH INDICATING THE SNOW BAND MAY EVEN
EXTEND WELL EASTWARD INTO NORTHERN HAMILTON COUNTY...WITH
ACCUMULATING SNOW ALL THE WAY TO INDIAN LAKE. ACTIVITY IS EXPECTED
TO GRADUALLY WEAKEN BY WEDNESDAY AFTERNOON AS CAPPING INVERSION
HEIGHTS LOWER TO AROUND 1 KM.
WILL MENTION JUST CHANCE POPS FOR SOME LEFTOVER WEAK LAKE EFFECT
SNOW SHOWERS OVER THE WESTERN ADIRONDACKS WEDNESDAY
NIGHT...OTHERWISE DRY CONDITIONS SHOULD PERSIST. TEMPERATURES WILL
CONTINUE TO BE BELOW NORMAL ALTHOUGH WITH LESS WIND. HIGH PRESSURE
WILL BUILD INTO THE REGION ON THURSDAY...WITH DRY CONDITIONS AND
TEMPERATURES MODERATING TO ONLY SLIGHTLY BELOW NORMAL READINGS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/...
EXPECT RELATIVELY MILD TEMPERATURES DURING THE LONG TERM PERIOD AS
SOUTHERLY/SOUTHWESTERLY FLOW DOMINATES MOST OF THE TIME.
SPOTTY LIGHT SNOW SHOWERS POSSIBLE THURSDAY NIGHT INTO FRIDAY AS A
VERY WEAK DISTURBANCE MOVES THROUGH ALONG THE LEADING EDGE OF THE
WARM ADVECTION. HAVE ONLY FORECAST 20 TO 30 POPS DURING THIS PERIOD.
LOWS THURSDAY NIGHT WILL BE IN THE SINGLE DIGITS AND TEENS. HIGHS
FRIDAY WILL BE IN THE 30S WITH TEMPS LIKELY WARM ENOUGH FOR MIXED
RAIN/SNOW SHOWERS OVER SOUTHERN AREAS DURING THE AFTERNOON...IF ANY
PCPN OCCURS.
FOR FRIDAY NIGHT THROUGH SATURDAY...THE SOUTHWESTERLY FLOW WILL
INCREASE...WITH A LARGE AREA OF MOISTURE SURGING INTO THE REGION
FROM THE GULF OF MEXICO...AHEAD OF A FRONTAL BOUNDARY MOVING EAST
FROM THE MISSISSIPPI VALLEY. MAINLY RAIN IS EXPECTED AS THIS
MOISTURE AND FRONTAL BOUNDARY MOVE THROUGH THE REGION. POPS HAVE
BEEN FORECAST TO INCREASE LATE FRIDAY NIGHT...REACHING LIKELY AND
HIGH CHANCE LEVELS ON SATURDAY AND EARLY SATURDAY NIGHT. THE FRONT
WILL MOVE THROUGH EARLY SATURDAY NIGHT...WITH POPS DECREASING LATE
SATURDAY NIGHT. LOWS FRIDAY NIGHT WILL BE IN THE 20S...WITH THE LOWS
LIKELY OCCURRING EARLY. HIGHS SATURDAY WILL GENERALLY BE IN THE
40S...AND LOWS SATURDAY NIGHT IN THE UPPER 20S TO MID 30S.
THE AIRMASS BEHIND THE FRONT WILL NOT BE OF ARCTIC OR POLAR
ORIGIN...SO IT WILL REMAIN MILD ON SUNDAY WITH ONLY A SLIGHT CHANCE
OF SHOWERS. HIGHS WILL BE IN THE MID 30S TO MID 40S. DRY CONDITIONS
SUNDAY NIGHT WITH LOWS IN THE 20S TO AROUND 30.
A STRONG LOW PRESSURE SYSTEM WILL TAKE SHAPE IN THE NORTHERN PLAINS
SUNDAY NIGHT AND MONDAY. IT WILL HAVE LITTLE DIRECT IMPACT ON THE
FORECAST AREA SINCE IT WILL MOVE NORTHEAST ACROSS LAKE SUPERIOR.
HOWEVER...GULF OF MEXICO MOISTURE WILL SURGE NORTHEASTWARD ONCE
AGAIN AHEAD OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM. HAVE ONLY
FORECAST 30 POPS FOR NOW SINCE IT IS STILL 6 TO 7 DAYS OUT.
HOWEVER...IT SHOULD BE MILD ENOUGH AGAIN FOR MAINLY RAIN WITH THIS
SYSTEM AS WELL. HIGHS MONDAY WILL BE IN THE UPPER 30S AND 40S.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
VFR AND GUSTY CONDITIONS WILL PREVAIL THROUGHOUT THE TAF PERIOD.
THIS AFTERNOON...MAINLY CLEAR SKIES WILL CONTINUE THIS AFTERNOON
EXCEPT AT KPSF WHERE OCCASIONAL BROKEN STRATOCUMULUS AROUND 4 KFT
REMAINS TIED TO THE TERRAIN. THERE WILL BE PLENTY OF LAKE-EFFECT
CLOUDS OFF LAKE ONTARIO...BUT WEST/SOUTHWESTERLY FLOW WILL KEEP MOST
OF THESE CLOUDS WEST OF THE TAF SITES. PRIMARY CONCERN THIS
AFTERNOON WILL BE A STRONG AND GUSTY WESTERLY WIND BEING INDUCED BY
A STRONG PRESSURE GRADIENT BETWEEN CYCLONIC FLOW ALOFT AND SURFACE
HIGH PRESSURE ATTEMPTING TO NUDGE NORTHWARDS ACROSS THE REGION.
WINDS WILL BE BETWEEN 12-18 KNOTS WITH OCCASIONAL GUSTS TO 25-30
KNOTS...ESPECIALLY AT KALB WHERE TERRAIN CHANNELING MAY ALLOW GUSTS
TO REACH 35 KNOTS AT TIMES.
TONIGHT INTO WEDNESDAY...SKIES WILL BECOME CLEAR TONIGHT AS HIGH
PRESSURE CONTINUES TO BUILD ACROSS THE REGION. WINDS WILL REMAIN
GUSTY...ALTHOUGH DIMINISHED SOMEWHAT AS NIGHTTIME MIXING IS
DEPRESSED. REGARDLESS...WINDS WILL BE AROUND 10-15 KNOTS WITH
OCCASIONAL GUSTS OF 20-25 KNOTS.
OTHER THAN A FEW STRATOCUMULUS AROUND 5 KFT WEDNESDAY...SKIES WILL
REMAIN MOSTLY CLEAR AT THE TAF SITES TO END THE TAF PERIOD...WITH A
WESTERLY WIND AROUND 10 KNOTS GUSTING TO 20 KNOTS...AND GRADUALLY
DIMINISHING THROUGHOUT THE DAY.
OUTLOOK...
WEDNESDAY TO THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SATURDAY-SUNDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...SHSN.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC PROBLEMS ARE EXPECTED OVER THE NEXT FIVE
DAYS.
FRIGID TEMPERATURES AND WINDY CONDITIONS WILL ALLOW FOR RIVER ICE TO
THICKEN THROUGH THURSDAY. TEMPERATURES ARE EXPECTED TO FINALLY
MODERATE TOWARD THE END OF THE WEEK INTO THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR CTZ001-013.
NY...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR NYZ058-063.
WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR NYZ032-033-
038>043-047>054-059>061-064>066-082>084.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST WEDNESDAY FOR NYZ032-
033.
MA...WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR MAZ001-025.
VT...WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...JPV
NEAR TERM...FRUGIS/11/JPV
SHORT TERM...JPV
LONG TERM...GJM
AVIATION...IRL
HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS ALBANY NY
1158 AM EST TUE JAN 7 2014
.SYNOPSIS...
A BROAD CYCLONIC FLOW OF FRIGID ARCTIC AIR WILL CONTINUE OVER THE
REGION THROUGH THE MIDDLE OF THE WEEK...WITH DANGEROUSLY COLD WIND
CHILLS AND BITTERLY COLD TEMPERATURES. PERSISTENT WESTERLY WINDS
WILL BRING SIGNIFICANT LAKE EFFECT SNOW DOWNWIND OF LAKE ONTARIO
INTO THE WESTERN ADIRONDACKS. A MODERATING TREND IS EXPECTED TOWARDS
THE END OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF NOON EST...TEMPERATURES REMAIN IN THE SINGLE DIGITS OVER
MUCH OF THE REGION. PERSISTENT AND GUSTY WESTERLY WINDS MAKING IT
FEEL EVEN COLDER...WITH WIND CHILLS GENERALLY IN THE -10 TO -25
DEGREE RANGE.
WIND CHILL WARNINGS REMAIN IN EFFECT FOR THE EASTERN
CATSKILLS...WITH WIND CHILL ADVISORIES FOR THE REST OF THE AREA.
TEMPERATURES WILL NOT MOVE MUCH TODAY...WITH HIGHS ONLY REACHING
AROUND 10 IN THE HUDSON VALLEY...WITH SINGLE DIGITS OVER THE
HIGHER TERRAIN. AGAIN...WIND CHILLS WILL MAKE IT FEEL EVEN COLDER
THROUGHOUT THE DAY. WITH A STRONG PRESSURE GRADIENT REMAINING OVER
THE REGION...WESTERLY WINDS WILL CONTINUE AT 20 TO 30 MPH...WITH
GUSTS OF 40 TO 45 MPH EXPECTED ESPECIALLY IN FAVORED WEST-EAST
ORIENTED VALLEYS AND HIGHER TERRAIN AREAS.
THE OTHER MAIN STORY TODAY WILL BE HEAVY LAKE EFFECT SNOW FOR
PORTIONS OF THE WESTERN ADIRONDACKS...ESPECIALLY NORTHERN HERKIMER
AND NORTHWEST HAMILTON COUNTIES. OVER THE LAST FEW HOURS...THE
BAND HAS SHIFTED NORTH INTO EXTREME NORTHERN HERKIMER COUNTY. THE
SNOW BAND IS NOW NORTH OF OLD FORGE AND STILLWATER
RESERVOIR...AFFECTING THE DEEP WOODS OF THE NORTHWESTERN CORNER OF
THE ADIRONDACK PARK. THE 12Z RUN OF LOCAL HIRESWRF AND THE LATEST
12Z RUN OF THE 3KM HRRR ALL SUGGEST THE BAND TO SLOWLY MOVE AND
SHIFT DURING THE DAY. EVENTUALLY...IT WILL BEGIN TO SHIFT BACK
SOUTH TOWARDS THE OLD FORGE AREA BY LATER THIS AFTERNOON AND INTO
THE EVENING.
WE ARE STILL CONFIDENT FOR THE SNOW BAND TO EXTEND THROUGH
NORTHERN HERKIMER AND INTO WESTERN HAMILTON COUNTY TODAY AS A
MULTI-LAKE CONNECTION FROM LAKE HURON EVENTUALLY OCCURS. LOCAL
CSTAR RESEARCH INDICATES WITHIN AN EXTREME LAKE-AIR INSTABILITY
REGIME SUCH AS THIS ONE...THE INLAND EXTENT WILL BE RATHER LIMITED
UNTIL A MULTI- LAKE CONNECTION IS ESTABLISHED. WE CUT BACK
SLIGHTLY ON THE AREAL COVERAGE OF THE HEAVIEST ACCUMULATIONS BUT
ARE STILL EXPECTING 12 TO 30 INCHES IN THE MOST PERSISTENT BANDS
MAINLY FROM AROUND OLD FORGE AND ALONG ROUTE 28 NORTHWARD. THE
HEAVIEST ACCUMULATIONS OF NEAR 30 INCHES WILL PROBABLY WIND UP
OCCURRING SOMEWHERE IN THE FOREST BETWEEN STILLWATER RESERVOIR AND
THE ST. LAWRENCE COUNTY BORDER.
OUTSIDE OF THE INTENSE LAKE EFFECT SNOW OVER THE WESTERN
ADIRONDACKS...ONLY SOME LIGHT SNOW SHOWERS ARE EXPECTED FOR LIMITED
AREAS OF THE SOUTHERN GREEN MOUNTAINS IN VERMONT. SKIES WILL BE
MOSTLY TO PARTLY SUNNY ACROSS THE REMAINDER OF THE REGION.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
FRIGID TEMPERATURES AND DANGEROUS WIND CHILLS WILL CONTINUE THROUGH
TONIGHT AND INTO WEDNESDAY MORNING. A WESTERLY BREEZE WILL PERSIST
DURING THE TIME...WITH TEMPERATURES EXPECTED TO BE IN THE SINGLE
DIGITS TO BELOW ZERO. THUS WILL CONTINUE ALL WIND CHILL HEADLINES
THROUGH 10 AM WEDNESDAY. TEMPERATURES ON WEDNESDAY WILL STILL BE
WELL BELOW NORMAL...ALTHOUGH MID TO UPPER TEENS ARE EXPECTED FOR
HIGHS RATHER THAN SINGLE DIGITS.
IT WILL BE DRY ACROSS MUCH OF THE AREA...ALTHOUGH HEAVY LAKE EFFECT
SNOW SHOULD CONTINUE ACROSS THE WESTERN ADIRONDACKS...AGAIN WITH THE
MOST PERSISTENT AND HIGHEST ACCUMULATIONS MAINLY FROM OLD FORGE AND
ROUTE 28 NORTHWARD TONIGHT INTO WEDNESDAY MORNING. LOCAL INLAND
EXTENT TOOL FROM CSTAR RESEARCH INDICATING THE SNOW BAND MAY EVEN
EXTEND WELL EASTWARD INTO NORTHERN HAMILTON COUNTY...WITH
ACCUMULATING SNOW ALL THE WAY TO INDIAN LAKE. ACTIVITY IS EXPECTED
TO GRADUALLY WEAKEN BY WEDNESDAY AFTERNOON AS CAPPING INVERSION
HEIGHTS LOWER TO AROUND 1 KM.
WILL MENTION JUST CHANCE POPS FOR SOME LEFTOVER WEAK LAKE EFFECT
SNOW SHOWERS OVER THE WESTERN ADIRONDACKS WEDNESDAY
NIGHT...OTHERWISE DRY CONDITIONS SHOULD PERSIST. TEMPERATURES WILL
CONTINUE TO BE BELOW NORMAL ALTHOUGH WITH LESS WIND. HIGH PRESSURE
WILL BUILD INTO THE REGION ON THURSDAY...WITH DRY CONDITIONS AND
TEMPERATURES MODERATING TO ONLY SLIGHTLY BELOW NORMAL READINGS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
EXPECT RELATIVELY MILD TEMPERATURES DURING THE LONG TERM PERIOD AS
SOUTHERLY/SOUTHWESTERLY FLOW DOMINATES MOST OF THE TIME.
SPOTTY LIGHT SNOW SHOWERS POSSIBLE THURSDAY NIGHT INTO FRIDAY AS A
VERY WEAK DISTURBANCE MOVES THROUGH ALONG THE LEADING EDGE OF THE
WARM ADVECTION. HAVE ONLY FORECAST 20 TO 30 POPS DURING THIS PERIOD.
LOWS THURSDAY NIGHT WILL BE IN THE SINGLE DIGITS AND TEENS. HIGHS
FRIDAY WILL BE IN THE 30S WITH TEMPS LIKELY WARM ENOUGH FOR MIXED
RAIN/SNOW SHOWERS OVER SOUTHERN AREAS DURING THE AFTERNOON...IF ANY
PCPN OCCURS.
FOR FRIDAY NIGHT THROUGH SATURDAY...THE SOUTHWESTERLY FLOW WILL
INCREASE...WITH A LARGE AREA OF MOISTURE SURGING INTO THE REGION
FROM THE GULF OF MEXICO...AHEAD OF A FRONTAL BOUNDARY MOVING EAST
FROM THE MISSISSIPPI VALLEY. MAINLY RAIN IS EXPECTED AS THIS
MOISTURE AND FRONTAL BOUNDARY MOVE THROUGH THE REGION. POPS HAVE
BEEN FORECAST TO INCREASE LATE FRIDAY NIGHT...REACHING LIKELY AND
HIGH CHANCE LEVELS ON SATURDAY AND EARLY SATURDAY NIGHT. THE FRONT
WILL MOVE THROUGH EARLY SATURDAY NIGHT...WITH POPS DECREASING LATE
SATURDAY NIGHT. LOWS FRIDAY NIGHT WILL BE IN THE 20S...WITH THE LOWS
LIKELY OCCURRING EARLY. HIGHS SATURDAY WILL GENERALLY BE IN THE
40S...AND LOWS SATURDAY NIGHT IN THE UPPER 20S TO MID 30S.
THE AIRMASS BEHIND THE FRONT WILL NOT BE OF ARCTIC OR POLAR
ORIGIN...SO IT WILL REMAIN MILD ON SUNDAY WITH ONLY A SLIGHT CHANCE
OF SHOWERS. HIGHS WILL BE IN THE MID 30S TO MID 40S. DRY CONDITIONS
SUNDAY NIGHT WITH LOWS IN THE 20S TO AROUND 30.
A STRONG LOW PRESSURE SYSTEM WILL TAKE SHAPE IN THE NORTHERN PLAINS
SUNDAY NIGHT AND MONDAY. IT WILL HAVE LITTLE DIRECT IMPACT ON THE
FORECAST AREA SINCE IT WILL MOVE NORTHEAST ACROSS LAKE SUPERIOR.
HOWEVER...GULF OF MEXICO MOISTURE WILL SURGE NORTHEASTWARD ONCE
AGAIN AHEAD OF THE COLD FRONT ASSOCIATED WITH THIS SYSTEM. HAVE ONLY
FORECAST 30 POPS FOR NOW SINCE IT IS STILL 6 TO 7 DAYS OUT.
HOWEVER...IT SHOULD BE MILD ENOUGH AGAIN FOR MAINLY RAIN WITH THIS
SYSTEM AS WELL. HIGHS MONDAY WILL BE IN THE UPPER 30S AND 40S.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
A STRONG CYCLONIC FLOW OF ARCTIC AIR INTO THE REGION WILL BE THE
PRIMARY FEATURE AFFECTING THE TAF SITES DURING THE PERIOD.
VFR CONDITIONS ARE EXPECTED TO DOMINATE THE NEXT 24 HOURS FOR THE
KGFL/KPSF/KALB/KPOU TAF SITES. ALTHOUGH THERE WILL BE A STRONG LAKE
EFFECT RESPONSE OFF LAKE ONTARIO...IT SHOULD BE ORIENTED IN A WEST
TO EAST DIRECTION...WHICH WOULD KEEP IT NORTH OF THE TAF SITES.
CLOUDS TODAY AT THE TAF SITES WILL BE SCT-BKN AT 3.5-5 KFT
AGL...WITH MAINLY BKN CLOUDS AT KPSF. TONIGHT EXPECT MAINLY SCT
CLOUDS.
THE MAIN WEATHER ISSUE AFFECTING THE TAF SITES WILL BE STRONG AND
GUSTY WESTERLY WINDS IN THE CYCLONIC FLOW. SURFACE WINDS TODAY WILL
BE 16 TO 22 KTS WITH GUSTS IN THE 25-35 KT RANGE...THEN LOWER TO 10
TO 15 KTS WITH GUSTS OF 20 TO 25 KTS THIS EVENING. TONIGHT THE WINDS
WILL CONTINUE TO DECREASE TO LESS THAN 10 KTS AT KGFL/KPOU AFTER
07Z...AND AROUND 10 KTS WITH GUSTS TO 15 KTS AT KALB/KPSF.
OUTLOOK...
WEDNESDAY TO THURSDAY: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHSN.
FRIDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA...SHSN.
FRIDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
SATURDAY: MODERATE OPERATIONAL IMPACT. LIKELY SHRA...SHSN.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC PROBLEMS ARE EXPECTED OVER THE NEXT FIVE
DAYS.
FRIGID TEMPERATURES AND WINDY CONDITIONS WILL ALLOW FOR RIVER ICE TO
THICKEN THROUGH THURSDAY. TEMPERATURES ARE EXPECTED TO FINALLY
MODERATE TOWARD THE END OF THE WEEK INTO THE WEEKEND.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR CTZ001-013.
NY...WIND CHILL WARNING UNTIL 10 AM EST WEDNESDAY FOR NYZ058-063.
WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR NYZ032-033-
038>043-047>054-059>061-064>066-082>084.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST WEDNESDAY FOR NYZ032-
033.
MA...WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR MAZ001-025.
VT...WIND CHILL ADVISORY UNTIL 10 AM EST WEDNESDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...JPV
NEAR TERM...FRUGIS/11/JPV
SHORT TERM...JPV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...JPV
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1159 AM CST TUE JAN 7 2014
.DISCUSSION...
1036 AM CST
MINOR UPDATES THIS MORNING...PRIMARILY ADJUSTING SKY GRIDS TO
ACCOUNT FOR MID/HIGH LEVEL MOISTURE STREAMING OUT AHEAD OF A WAVE
OF ENERGY TRAVERSING THE REGION. SATELLITE IMAGERY DEPICTING A
FAIRLY THICK MID/HIGH LEVEL CLOUD SHIELD QUICKLY EXPANDING
SOUTHEAST OVER THE AREA...AND ANTICIPATE THIS TO BE IN PLACE FOR
MOST OF TODAY BEFORE SLOWLY SLIDING TO THE SOUTHEAST. CURRENT WIND
CHILL WARNING WHICH IS SET TO EXPIRE AT MID DAY STILL APPEARS TO
BE ON PAR...WITH WIND CHILLS STILL IN THE 25 TO 30 BELOW ZERO
RANGE AT THIS HOUR. EXPECT A SLOW WARMING TREND INTO THE
AFTERNOON...RISING ABOVE ZERO IN MOST LOCATIONS. ALTHOUGH...DO
EXPECT WIND CHILLS TO REMAIN IN THE 10 TO 20 BELOW ZERO RANGE
THROUGH MID AFTERNOON BUT ALSO OBSERVING SOME SLIGHT MODERATION AS
WELL. CURRENT BUILDING SURFACE RIDGE WILL CONTINUE TO WORK ITS WAY
OVERHEAD TODAY...WITH WINDS DIMINISHING THIS AFTERNOON INTO THE
EVENING.
RODRIGUEZ
//PREV DISCUSSION...
352 AM CST
FORECAST CONCERNS INCLUDE SLOW IMPROVEMENT IN BITTER COLD TEMPS AND
WIND CHILLS TODAY...A CHANCE OF SOME LIGHT SNOW WEDNESDAY AND AGAIN
THURSDAY MAINLY ACROSS THE SOUTHERN HALF OF THE FORECAST AREA...AND
FINALLY A MIXED PRECIP/RAIN SYSTEM FRIDAY/SATURDAY AS TEMPS CLIMB
ABOVE FREEZING.
THE DEEP MID-LEVEL TROUGH AND CORE OF COLDEST TEMPERATURES ALOFT
WHICH WERE OVER THE WESTERN GREAT LAKES REGION PER 00Z UPPER AIR
ANALYSIS HAS MOVED EAST ACROSS THE EASTERN LAKES AND UPPER OHIO
VALLEY EARLY THIS MORNING PER GOES WATER VAPOR LOOP. OF COURSE
SURFACE TEMPS OVER DEEP SNOW COVER ARE STILL QUITE COLD...THOUGH
TEMPS HAVE BECOME FAIRLY STEADY IN THE -8 TO -14 DEGREE RANGE ACROSS
THE CWA OVERNIGHT. GRADUALLY DIMINISHING WEST WINDS STILL PRODUCING
WIND CHILLS IN THE -28 TO -34 RANGE AT 3 AM...THOUGH THESE
CONDITIONS SHOULD GRADUALLY IMPROVE THIS MORNING AS WINDS DIMINISH
FURTHER WITH ARRIVAL OF WEAK SURFACE HIGH PRESSURE RIDGE FROM THE
WEST. WHILE A COUPLE OF AWOS SITES ACROSS OUR SOUTHWEST ARE JUST SHY
OF WIND CHILL WARNING CRITERIA...SEE NO ADVANTAGE IN CHANGING
HEADLINES AT THIS TIME AND WILL ALLOW DAY SHIFT TO DOWNGRADE BLOCKS
OF THE WARNING A LITTLE LATER THIS MORNING AS CONDITIONS WARRANT.
TEMPS SHOULD RISE INTO THE SINGLE DIGITS...ABOVE ZERO...DURING THE
DAY WITH WIND CHILLS RISING ABOVE EVEN ADVISORY CRITERIA BY EARLY
AFTERNOON.
UPPER FLOW PROGGED TO DE-AMPLIFY A BIT ACROSS THE CONUS TODAY WHILE
A COUPLE OF QUICK-MOVING CLIPPERS RIDE THE JET ALONG THE BAROCLINIC
ZONE FROM THE NORTHERN PLAINS TO THE OHIO VALLEY. GUIDANCE IN GOOD
AGREEMENT IN BRINGING ONE SUCH SYSTEM ACROSS THE AREA THIS
AFTERNOON...THOUGH IN A RATHER SHEARED AND MOISTURE-STARVED FASHION.
LIGHT SNOW CURRENTLY ACCOMPANYING THIS FEATURE ACROSS THE WESTERN
DAKOTAS...THOUGH SREF ENSEMBLE MEAN POPS DECREASE TO NIL AS IT THE
SYSTEM RAPIDLY MOVES INTO OUR AREA THIS AFTERNOON. DESPITE
ISENTROPIC ASCENT/WARM ADVECTION ACROSS THE ELEVATED THERMAL
GRADIENT...MODEL TIME SECTIONS INDICATE A DEARTH OF MOISTURE IN
LOWER LEVELS THIS AFTERNOON. OTHER THAN AN INCREASE IN SOME MID/HIGH
LEVEL CLOUDS...AM NOT EXPECTING PRECIP WITH THIS WAVE. BAROCLINIC
ZONE ENDS UP STRETCHED WEST-EAST FROM THE IA/MO BORDER EAST ACROSS
CENTRAL IL AND IND ON WEDNESDAY...AS ANOTHER SHORT WAVE TROUGH
(CURRENTLY OVER THE PACIFIC NORTHWEST) APPROACHES. GUIDANCE IS IN
REASONABLE AGREEMENT IN DEVELOPING A RELATIVELY NARROW BAND OF LIGHT
SNOW GENERALLY ALONG AND SOUTH OF THE I-80 CORRIDOR WITH MODEST
FRONTOGENETIC FORCING AND A LITTLE DIVERGENCE ALOFT WITH THE RIGHT
ENTRANCE REGION OF AN UPPER LEVEL JET STREAK TRANSLATING EAST FROM
THE GREAT LAKES. SNOW AMOUNTS LOOK TO BE LESS THAN AN INCH ACROSS
THE SOUTHERN COUNTIES OF THE CWA WEDNESDAY AFTERNOON. ECMWF/GFS
REMAIN IN DECENT AGREEMENT IN BRINGING A SECOND SHORT WAVE ACROSS
THE REGION THURSDAY...WITH SNOW REDEVELOPING ACROSS CENTRAL IL AND
LIFTING ACROSS MAINLY THE SOUTHEAST PART OF THE CWA. WHILE SOME
DIFFERENCES EXIST WITH VARIOUS MODELS...A BLEND OF EC/GFS/SREF QPF
OUTPUT SUGGESTS THE SOUTHERN CWA WILL AGAIN BE FAVORED FOR SOME
LIGHT ACCUMULATING SNOW OF PERHAPS 1-2 INCHES. TEMPS DURING THE
WEDNESDAY/THURSDAY PERIOD WILL BE SLOWLY MODERATING...WITH A FAIR
AMOUNT OF CONTRAST FROM NORTH-SOUTH THANKS TO PRESENCE OF THE
BAROCLINIC ZONE AND LESS CLOUD COVER TO THE NORTH.
GLOBAL GUIDANCE ALL INDICATE LONG-WAVE TROUGH UPPER TROUGH
DEVELOPMENT OVER THE WESTERN CONUS THURSDAY-FRIDAY...WHICH INDUCES
DOWNSTREAM RIDGE ACROSS THE MIDWEST AND EASTERN US. THIS WILL RESULT
IN WARMING TEMPS...THOUGH WITH A SURGE OF MOISTURE ACROSS THE REGION
FRIDAY. BASED ON THERMAL PROFILES/THICKNESS FIELDS...THE CURRENT
EXPECTATION IS THAT PRECIP WILL DEVELOP ACROSS THE AREA FRIDAY AND
COULD BEGIN AS A MIX OF LIGHT RAIN/FREEZING RAIN/SLEET...THOUGH
WOULD LIKELY CHANGE OVER TO RAIN ACROSS ALL/MOST OF THE FORECAST
AREA IN THE AFTERNOON. GUIDANCE DOES APPEAR TO BE SLOWING THE ONSET
OF THE PRECIP A LITTLE...WHICH WOULD HELP MINIMIZE THE AMOUNT OF
MIXED PRECIP WITH COLDER TEMPS IN PLACE DURING THE MORNING. BOTH
GFS/ECMWF DO PRODUCE 0.25-0.50 INCHES OF LIQUID QPF THROUGH FRIDAY
WHICH COMBINED WITH SOME MELTING OF DEEP SNOW PACK COULD LEAD TO
SOME FLOODING/HYDRO ISSUES HEADING INTO NEXT WEEKEND WITH TEMPS
WARMING TO THE UPPER 30S/AROUND 40. ECMWF DEPICTS ANOTHER ROUND OF
RAIN INTO THE AREA LATE SUNDAY...WHILE GFS TRENDS DRIER/COLDER...AS
MODELS DIFFER WITH PHASING OF NORTHERN STREAM TROUGH AND UPPER LOW
IN SOUTHERN PORTION OF LONG-WAVE BY DAYS 6-7. FOR NOW HAVE USED A
BLENDED GUIDANCE SOLUTION FOR TEMPS/PRECIP SUNDAY NIGHT-MONDAY.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* NONE
IZZI
//DISCUSSION...UPDATED 18Z...
SURFACE HIGH PRESSURE WILL TRACK EASTWARD TO THE SOUTH OF THE
REGION WITH WEST TO SOUTHWEST WINDS CONTINUING THROUGH THE
AFTERNOON WITH SOME OCNL GUSTS IN THE 15-20KT RANGE EXPECTED.
WINDS WILL SUBSIDE THIS EVENING AND REMAIN LESS GENERALLY THAN
10KT THROUGH THE DAY WEDNESDAY. VFR CIGS ARE EXPECTED THROUGH THE
PERIOD WITH LITTLE THREAT OF ANY CIGS BELOW FL030.
IZZI
//ORD AND MDW CONFIDENCE...UPDATED 18Z...
* HIGH CONFIDENCE IN ALL FORECAST ELEMENTS
IZZI
//OUTLOOK FOR ORD/MDW FOR 00Z THURSDAY-12Z TUESDAY...UPDATED 12Z...
WEDNESDAY NIGHT...VFR.
THURSDAY...CHANCE OF LIGHT SNOW AND MVFR CIGS/VIS EARLY.
FRIDAY...CHANCE OF WINTRY MIX EARLY...BECOMING RAIN. MVFR/IFR
CIGS/VIS POSSIBLE.
SATURDAY...SLIGHT CHANCE OF LIGHT RAIN AND MVFR EARLY...THEN VFR.
SUNDAY...SLIGHT CHANCE LIGHT SNOW OVERNIGHT. MVFR CIGS/VIS
POSSIBLE.
MONDAY...CHANCE OF LIGHT RAIN OR SNOW AND MVFR CIGS/VIS .
&&
.MARINE...
300 AM CST
WINDS ARE SLOWLY DIMINISHING OVER THE LAKE AS THE PRESSURE
GRADIENT GRADUALLY RELAXES. HAVE DROPPED THE GALE WARNING FOR THE
SOUTH HALF OF THE LAKE AND THE INDIANA NEARSHORE WATERS.
HOWEVER...WINDS GUSTING TO 30KT SHOULD HANG IN THROUGH MUCH OF
TODAY...KEEPING THE THREAT OF HEAVY FREEZING SPRAY GOING AS THERE
WILL BE LITTLE MODIFICATION OF THE AIRMASS. ALSO...WILL NEED TO
REPLACE THE GALE WARNING FOR THE INDIANA NEARSHORE WATERS WITH A
SMALL CRAFT ADVISORY WHILE MAINTAINING THE SMALL CRAFT ADVISORY
FOR THE ILLINOIS NEARSHORE WATERS. ALSO...WILL MAINTAIN THE GOING
HEAVY FREEZING SPRAY WARNING THROUGH THE DAY AS WELL. WINDS SHOULD
DIMINISH ENOUGH BY THIS EVENING THAT THE THREAT FOR ANY ADDITIONAL
HEAVY FREEZING SPRAY WILL SUBSIDE. BY EARLY THURSDAY THE ARCTIC
HIGH WILL MOVE EAST OF THE LAKE AND WINDS WILL INCREASINGLY BECOME
SOUTHERLY...ESPECIALLY WITH A NEW TROUGH OF LOW PRESSURE
DEVELOPING OVER THE PLAINS. WINDS SHOULD PICK UP INTO THE 30KT
RANGE FOR THURSDAY NIGHT AND FRIDAY...BUT WITH THE SOUTHERLY FLOW
DRAWING WARMER AIR NORTHWARD...THERE WILL BE NO THREAT FOR
FREEZING SPRAY...BUT A SMALL CRAFT ADVISORY WILL LIKELY BE NEEDED
BY THEN.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WIND CHILL WARNING...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032-ILZ033-ILZ039 UNTIL NOON TUESDAY.
IN...WIND CHILL WARNING...INZ001-INZ002-INZ010-INZ011-INZ019 UNTIL
NOON TUESDAY.
LM...HEAVY FREEZING SPRAY WARNING...LMZ080-LMZ261-LMZ362-LMZ364-
LMZ366-LMZ563-LMZ565-LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-
LMZ743-LMZ744-LMZ745-LMZ777-LMZ779-LMZ868-LMZ870-LMZ872-
LMZ874-LMZ876-LMZ878 UNTIL 6 PM TUESDAY.
SMALL CRAFT ADVISORY...INDIANA NEARSHORE WATERS UNTIL 4 PM TUESDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1045 AM CST Tue Jan 7 2014
.DISCUSSION...
ISSUED 1045 AM CST Tue Jan 7 2014
Will update the forecast at noon allowing the wind chill warning
to expire at that time across central IL. Wind chills late this
morning average from 15-25 below zero, except closer to 10 below
zero in southern 6 counties. Bloomington is coldest wind chill of
26 below zero. Mid level clouds already spreading east into
eastern IL late this morning with areas west of I-57 nearly cloudy.
Updated sky grids to increase cloud cover today and evening. Rest of
forecast looks on track into this evening. Highs range from 8-15F
with coolest readings from I-74 northeast. South to southwest
winds of 10-15 mph today with few gusts of 15-20 mph.
1040 mb arctic high pressure over the lower MS river valley and
ridging into TN/KY will continue to weaken to 1035 mb over the
Carolinas by dawn Wed. A warm front from northeast Nebraska to
near the MO/IA border to move into central IL tonight with temps
not falling much tonight due to this frontal boundary in area and
more cloud cover. Lows tonight around 5F northern areas and lower
teens southern areas.
07
&&
.AVIATION...
ISSUED 525 AM CST Tue Jan 7 2014
VFR conditions are expected today across the forecast area with
the potential for cigs to lower to MVFR cat after 00z...especially
across the north.
Arctic high pressure will continue drift away from the region
today with the latest satellite data and upstream surface
observations indicating a band of mid level clouds over parts of
north central Iowa. This cloud band is expected to drift southeast
and affect most of the TAF sites today with a weak weather system
developing over parts of southern Iowa into northern Missouri this
evening. Models indicate a weak warm front developing over northeast
Missouri with the frontal system edging slowly to the east. Along and
north of this boundary, some MVFR cigs are forecast to develop after
00z this evening which is being confirmed by the latest HRRR and
Short Range Ensemble models. As a result, will continue to lower
the cigs from 6000-8000 feet that are expected over the area later
this morning thru this afternoon, to btwn 2500-3500 feet tonight.
For now, will limit the MVFR cigs to the northern TAF sites (KPIA
and KBMI).
Surface winds will continue to back more into a southerly direction
today as the high pressure system shifts off to our southeast. Wind
speeds today will range from 10 to 15 kts. Winds will be light
south to southeast tonight with speeds less than 10 kts.
Smith
&&
.PREV DISCUSSION...
ISSUED 325 AM CST Tue Jan 7 2014
Arctic blast slowly edging south and temperatures expected to
begin to modify slowly this afternoon. Expansive area of high
pressure spreading over the center of the country gets interrupted
by a quick system on Wed night...and another for Friday and the
first half of the weekend. Temperatures starting to warm up enough
to have an impact on precip type. Extended differs greatly as a
wave ejects out of the southwest...but the GFS carries the system
further south and east, missing Central Illinois altogether. ECMWF
has a bit more of a southwesterly flow aloft...more amplified than
the GFS, and as a result quite a bit more qpf to wrap up the
weekend and start the next work week.
SHORT TERM...Today and tomorrow...
Finally saying goodbye to the bitterly cold temperatures as the
airmass slowly modifies behind the arctic blast. Highs today above
zero...and though very little change in the hourly temperatures
through the overnight with the lows being only a few degrees lower
than todays highs...tomorrow temps climb a bit more. Models
alternating with timing of impacts of two small features for
Wednesday/Wed night. Precip coverage and likelihood smaller with
the day time feature, focused more to the north along a weak
boundary. Better chances for precip Wed night into Thursday.
System should be dominated by snow early on, but accumulations
will remain small.
LONG TERM...Thursday through Monday...
Small accumulations generally less than an inch for Thursday will
come to an end late Thursday as the airmass dries aloft and
crystals are lost. Mixing in some freezing drizzle on the back
edge of the precip with this system. At this point, temperatures
should be climbing above zero across Central Illinois for Friday
and into the weekend. Another system moving in Friday night being
a bit more problematic with the midlevels warming and a lack of
dendrites the precip will have the potential to be more of a
wintry mix and icy. NAM significantly warmer...even at the surface
by a couple degrees resulting in more of a rain solution. So at
this point... precip on Friday before noon a bit of an issue.
After 18z, dominated by rain in ILX CWA. Friday night...timing of
cold air moving in behind the precip will also possibly change the
rain over... but the timing differences at this point put the end
of the rain prior to the arrival of the colder air. Next major
system has major differences in track and timing...another wave
rippling across the swrn portion of the conus and moving into the
Ohio River Valley. GFS is far enough south that it never impacts
the CWA. The ECMWF tracks more NE. The extended, as a result, has
a couple periods with chance pops until more consistency works
into the solutions.
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING until Noon CST today FOR ILZ027>031-036>038-
040>057-061>063-066>068-071>073.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
317 PM EST TUE JAN 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 417 AM EST TUE JAN 7 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOWS DEEP POLAR VORTEX
CENTERED FM NCENTRAL ONTARIO S INTO THE GRT LKS...WITH DEEP CYC NW
FLOW OF BITTERLY COLD AIR ARND SFC LO PRES IN NRN QUEBEC. H5/H7/H85
TEMPS WITHIN THE CORE OF COLDEST AIR AT 00Z EXTENDING FM NW ONTARIO
INTO MI WERE -45C/-35C/-30C. LLVL NW WINDS ARE UP TO 35-40 KTS PER
THE MQT 88D VWP UNDER THE FAIRLY TIGHT PRES GRADIENT OVER THE UPR
LKS... AND THE COMBINATION OF THE STEADY SFC WINDS AND THE BRUTAL
COLD THAT HAS DROPPED SFC TEMPS TO ARND -20F OVER THE INTERIOR W
HAVE CAUSED WIND CHILLS TO FALL AS LO AS -35F TO -45F OVER THE
ENTIRE CWA EARLY THIS MRNG. LES ALSO PERSISTS IN THE W TO NW WIND SN
BELTS OVER THE W AND NEAR LK SUP E OF PICTURED ROCKS. AN AREA OF
THICKER CLDS AND SOME SPOTTY -SN ARE SPREADING SEWD THRU NW ONTARIO
TOWARD THE UPR LKS IN ASSOCIATION WITH A SHRTWV DIGGING SSEWD IN NW
ONTARIO ON THE WRN FLANK OF THE POLAR VORTEX.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON RECORD LO TEMPS/WIND
CHILLS/LES AND GOING HEADLINES.
TDAY...AREA OF DPVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH SHRTWV
SLIDING SEWD THRU NE LK SUP THIS MRNG WL MAINTAIN DEEPER MSTR/MIXED
LYR AND AID IN MORE WDSPRD LES. THE SHSN WL BE SOMEWHAT HEAVIER OVER
THE E GIVEN LONGER FETCH/OPPORTUNITY FOR MOISTENING OVER THE E NEAR
LK SUP...WHERE SHARPENED LAND BREEZE CNVGC WL BE THE RULE AND SLGTLY
WARMER TEMPS MODIFIED BY LONGER PASSAGE OVER LK SUP WL NOT HAMPER SN
GROWTH AS SGNFTLY AS OVER THE W. FOLLOWING THE PASSAGE OF THE SHRTWV
TO THE E BY THIS AFTN...DNVA/LARGER SCALE QVECTOR DVGC WL
DOMINATE...WITH ACCOMPANYING SUBSIDENCE DRYING THE MID LVLS AND
CAUSING INVRN BASES TO SINK TO 4-5K FT. SO EXPECT LES INTENSITY TO
DIMINISH. DEPARTURE OF CORE OF COLDEST AIR/POLAR VORTEX TO THE NE
INTO QUEBEC THAT CAUSES H85 TEMPS TO RISE FM ARND -25C AT 12Z TO
CLOSER TO -20C BY 00Z WED WL ALLOW TEMPS TO RECOVER A BIT COMPARED
TO MON. IN CONCERT WITH SLACKENING PRES GRADIENT/SLOWLY DIMINISHING
WINDS...WIND CHILLS SHOULD EASE ABV WRNG THRESHOLDS THIS AFTN AND
THE MAGNITUDE OF THE BLSN IN AREAS IMPACTED BY THE LES SHOULD
SUBSIDE A BIT AS WELL. DID EXTEND THE GOING WRNG FOR A FEW HRS OVER
THE INTERIOR W HALF TO ACCOUNT FOR ADVY CRITERIA THAT WL PERSIST
THERE A BIT LONGER INTO THE AFTN.
TNGT...AS THE ARCTIC AIRMASS RETREATS FARTHER TO THE NE...THE PRES
GRADIENT/LLVL WINDS WL SLOWLY SLACKEN AND H85 TEMPS WL RISE TO ARND
-18C BY 12Z WED UNDER GENERAL SUBSIDENCE THAT WL SHARPEN AN INVRN
ARND 3-4K FT. EVEN THOUGH A SLOW WARMING WL ALLOW FOR IMPROVED SN
GROWTH...LOWERING INVRN BASE SHOULD LIMIT LES INTENSITY ESPECIALLY
OVER THE W. WL NOT EXTEND LES ADVYS BEYOND SCHEDULED EXPIRATION AT
00Z THIS EVNG GIVEN THE EXPECTED DIMINISHING SN TRENDS/WINDS THAT WL
ALSO DIMINISH THE MAGNITUDE OF THE BLSN/WIND CHILLS. ALTHOUGH H85
TEMPS WL MODERATE TNGT...SFC TEMPS MAY STILL PLUNGE SHARPLY AOB -20F
AWAY FM LK MODERATION WITH EXPECTATION THAT LARGER SCALE SUBSIDENCE
WL ALLOW FOR MOCLR SKIES IN THE PRESENCE OF LIGHTER WINDS. APRNT
TEMPS MAY REACH THE WIND CHILL ADVY CRITERIA...BUT OVERALL WINDS
SHOULD BE LIGHT ENUF TO JUSTIFY NO EXTENTION OF WIND CHILL HEADLINES
WHERE THE TEMPS FALL MORE SHARPLY AT THE MORE SHELTERED INTERIOR
LOCATIONS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 417 AM EST TUE JAN 7 2014
FOR WED/WED NIGHT...THE CWA WILL BE BETWEEN A SFC LOW MOVING E AND A
SFC HIGH MOVING IN FROM THE W. WHILE INVERSION HEIGHTS WILL
GRADUALLY LOWER THROUGH THE PERIOD...DO NOT EXPECT MUCH CHANGE IN
WNW-NW WIND LES WED AS WARMING TEMPS WILL PUT MORE OF THE LOW LEVELS
IN THE DGZ SO RATIOS WILL BE A BIT BETTER ALONG WITH A SHORTWAVE
MOVING NE OF THE CWA DURING THE AFTERNOON/EVENING WHICH WILL PROVIDE
SOME SYNOPTIC SUPPORT. THESE FACTORS WILL HELP OFFSET LOWERING
INVERSION HEIGHTS. FOR WED NIGHT...EXPECT LES TO LINGER MAINLY OVER
NE UPPER MI AS THE SFC HIGH MOVES S OF THE CWA WHILE DIMINISHING
OVERALL. DID NOT CHANGE FORECAST MUCH AS PREVIOUS FORECAST LOOKED
GOOD AND EXPECTATIONS HAVE NOT CHANGED SIGNIFICANTLY.
THU INTO EARLY SAT IS TRICKY AS A DISTURBANCE MOVES INTO THE PACIFIC
NW WED NIGHT...WITH NRN AND SRN JET STREAM INTERACTIONS CONTRIBUTING
TO THE SYSTEM STRENGTHENING OVER THE WRN CONUS. WITH THESE TYPES OF
NRN AND SRN STREAM INTERACTIONS...THE SITUATION IS ALWAYS MORE
UNCERTAIN AS MODELS HAVE TROUBLE HANDLING ENERGY ALLOCATION. AREA
WIDE SYSTEM SNOW IS A POSSIBILITY AS ENERGY LIFTS NE OUT OF THE
CENTRAL CONUS FRI INTO FRI NIGHT...BUT OVERALL CHANCES AND
DEFINITELY FINE DETAILS ARE FAR FROM CERTAIN. ONE THING MORE CERTAIN
IS THAT SW WINDS THU THROUGH FRI WILL RESULT AS THE HIGH EXITS E AND
THE TROUGH MOVES IN FROM THE W. MODELS ARE HINTING AT SW FLOW LES
OFF LAKE MICHIGAN...BUT WITH WARMING TEMPS AND THE NORMALLY TRICKY
NATURE OF LES IN THAT REGIME...WILL NOT ADD SIGNIFICANT EMPHASIS AT
THIS TIME. AHEAD OF THE TROUGH...MODELS INDICATE 850MB TEMPS
APPROACHING 0C FRI INTO EARLY SAT...WHICH WILL LEAD TO TEMPS RISING
CLOSER TO FREEZING FRI AND SAT.
SUN INTO MON ARE EVEN MORE UNCERTAIN AS MODELS INDICATE A QUICK
HITTING DISTURBANCE GENERALLY MOVING ALONG THE US/CANADIAN
BORDER...BUT DETAILS WITH THIS SYSTEM ARE FAR FROM CERTAIN...EVEN
GIVEN THE CURRENT GENERAL MODEL AGREEMENT. BEST THAT CAN BE SAID AT
THIS POINT IS THAT THERE IS POTENTIAL FOR A STRONGER SYSTEM TO MOVE
THROUGH OR NEAR THE REGION AND AT LEAST A QUICK SHOT OF WARMER TEMPS
AROUND FREEZING IS POSSIBLE. USED A GENERAL CONSENSUS OF GUIDANCE
FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1250 PM EST TUE JAN 7 2014
CMX...GUSTY WNW FLOW OF ARCTIC AIR WL BRING NEARLY CONTINUOUS
-SHSN/BLSN AND LIFR TO VLIFR CONDITIONS REMAINING. IN FACT VIS HAS
BEEN STUCK AT 1/4SM OR LESS SINCE 13Z. EXPECT A WEAKENING TREND
OVERALL...BUT IT WILL BE SLOW GOING. A NEARLY STEADY BAND OF LES
SHOWN ON THE VIS SATELLITE IMG SHOWN THAT IT IS MOVING SLIGHTLY N
THIS AFTERNOON. THE RESULT WILL BE MORE VARIABILITY IN THE
VIS/CEILINGS...WITH SLOW IMPROVEMENT LATE THIS AFTERNOON/OVERNIGHT
AS WINDS DIMINISH AND VIS IMPROVES. LARGER SCALE DRYING WILL QUICKLY
TAKE HOLD WEDNESDAY AFTERNOON.
IWD...MOST OF THE CLOUDS AND ASSOCIATED SNOW SHOWERS HAVE REMAINED
OFF SHORE...WITH VFR CEILINGS DOMINATING. THE POTENTIAL FOR MVFR
CEILINGS WILL LINGER THROUGH MID AFTERNOON...BEFORE LIGHTER WINDS
AND DRIER AIR SWINGS IN.
SAW...A SECONDARY BAND OF LIGHT SNOW SET UP ACROSS N CENTRAL UPPER
MI WILL KEEP THE POTENTIAL FOR MVFR CEILINGS AND A FEW LIGHT SNOW
SHOWERS AT SAW THROUGH LATE AFTERNOON...BEFORE VFR CEILINGS/VIS TAKE
HOLD AND REMAIN THROUGH THE PERIOD AS W-WNW WINDS KEEP THE FOCUS OF
LES TO THE W AND E.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 317 PM EST TUE JAN 7 2014
WEAKENING W-WNW WINDS WILL BE THE RULE THROUGH EARLY WEDNESDAY
MORNING. HOWEVER...WITH THE CONTINUED ARCTIC AIRMASS AND STEADY WIND
DIRECTION...WAVES WILL NOT DIMINISH RAPIDLY AND FREEZING SPRAY WILL
CONTINUE TO BE A CONCERN THROUGH WEDNESDAY/WEDNESDAY EVENING...AND
POSSIBLY AGAIN ON THURSDAY. WHILE WINDS WILL INCREASE WITH GUSTS
NEARING 25-30KTS NO GALES ARE FORESEEN THROUGH THE REST OF THE FCST
PERIOD AT THIS TIME.
THE DEEP LOW N QUEBEC WILL REMAIN NEARLY STATIONARY THROUGH
WEDNESDAY...WITH A TROUGH SLOWLY FILLING OVER LAKE SUPERIOR. HIGH
PRESSURE ACROSS S CENTRAL CANADA AND THE N PLAINS WILL SINK ACROSS
MINNESOTA AND WISCONSIN ON WEDNESDAY...AND BRIEFLY PUSH A RIDGE
ACROSS LAKE SUPERIOR WEDNESDAY NIGHT...BEFORE MOVING OFF THE NEW
ENGLAND COAST THURSDAY NIGHT. EXPECT A WEAKENING RIDGE TO LINGER
ACROSS THE UPPER GREAT LAKES UNTIL LOW PRESSURE NEARS FROM MANITOBA
FRIDAY. THE LOW WILL SHIFT ACROSS ONTARIO FRIDAY NIGHT...WHILE
DRAGGING A TROUGH OVER LAKE SUPERIOR FRIDAY NIGHT INTO SATURDAY. A
BRIEF RIDGE WILL PUSH ACROSS LAKE SUPERIOR SATURDAY NIGHT. EXPECT
ALLOW OVER SOUTHERN MANITOBA TO SLIDE ACROSS ONTARIO SUNDAY...WHILE
BRINGING A TROUGH ACROSS LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 1 PM EST /NOON CST/ WEDNESDAY FOR
MIZ002-004-005-009>011-084.
WIND CHILL ADVISORY FROM 11 PM EST /10 PM CST/ THIS EVENING TO 9
AM EST /8 AM CST/ WEDNESDAY FOR MIZ006-007-012>014-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST WEDNESDAY FOR
MIZ001>003-006-007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 9 PM EST WEDNESDAY FOR LSZ266-
267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265-266.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-263>265.
HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST WEDNESDAY FOR
LSZ243>245-249>251.
HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST THIS EVENING FOR
LSZ248.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1251 PM EST TUE JAN 7 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 417 AM EST TUE JAN 7 2014
00Z RAOBS/LATEST WV IMAGERY AND RUC ANALYSIS SHOWS DEEP POLAR VORTEX
CENTERED FM NCENTRAL ONTARIO S INTO THE GRT LKS...WITH DEEP CYC NW
FLOW OF BITTERLY COLD AIR ARND SFC LO PRES IN NRN QUEBEC. H5/H7/H85
TEMPS WITHIN THE CORE OF COLDEST AIR AT 00Z EXTENDING FM NW ONTARIO
INTO MI WERE -45C/-35C/-30C. LLVL NW WINDS ARE UP TO 35-40 KTS PER
THE MQT 88D VWP UNDER THE FAIRLY TIGHT PRES GRADIENT OVER THE UPR
LKS... AND THE COMBINATION OF THE STEADY SFC WINDS AND THE BRUTAL
COLD THAT HAS DROPPED SFC TEMPS TO ARND -20F OVER THE INTERIOR W
HAVE CAUSED WIND CHILLS TO FALL AS LO AS -35F TO -45F OVER THE
ENTIRE CWA EARLY THIS MRNG. LES ALSO PERSISTS IN THE W TO NW WIND SN
BELTS OVER THE W AND NEAR LK SUP E OF PICTURED ROCKS. AN AREA OF
THICKER CLDS AND SOME SPOTTY -SN ARE SPREADING SEWD THRU NW ONTARIO
TOWARD THE UPR LKS IN ASSOCIATION WITH A SHRTWV DIGGING SSEWD IN NW
ONTARIO ON THE WRN FLANK OF THE POLAR VORTEX.
MAIN FCST CONCERNS IN THE SHORT TERM FOCUS ON RECORD LO TEMPS/WIND
CHILLS/LES AND GOING HEADLINES.
TDAY...AREA OF DPVA/DEEP LYR QVECTOR CNVGC ASSOCIATED WITH SHRTWV
SLIDING SEWD THRU NE LK SUP THIS MRNG WL MAINTAIN DEEPER MSTR/MIXED
LYR AND AID IN MORE WDSPRD LES. THE SHSN WL BE SOMEWHAT HEAVIER OVER
THE E GIVEN LONGER FETCH/OPPORTUNITY FOR MOISTENING OVER THE E NEAR
LK SUP...WHERE SHARPENED LAND BREEZE CNVGC WL BE THE RULE AND SLGTLY
WARMER TEMPS MODIFIED BY LONGER PASSAGE OVER LK SUP WL NOT HAMPER SN
GROWTH AS SGNFTLY AS OVER THE W. FOLLOWING THE PASSAGE OF THE SHRTWV
TO THE E BY THIS AFTN...DNVA/LARGER SCALE QVECTOR DVGC WL
DOMINATE...WITH ACCOMPANYING SUBSIDENCE DRYING THE MID LVLS AND
CAUSING INVRN BASES TO SINK TO 4-5K FT. SO EXPECT LES INTENSITY TO
DIMINISH. DEPARTURE OF CORE OF COLDEST AIR/POLAR VORTEX TO THE NE
INTO QUEBEC THAT CAUSES H85 TEMPS TO RISE FM ARND -25C AT 12Z TO
CLOSER TO -20C BY 00Z WED WL ALLOW TEMPS TO RECOVER A BIT COMPARED
TO MON. IN CONCERT WITH SLACKENING PRES GRADIENT/SLOWLY DIMINISHING
WINDS...WIND CHILLS SHOULD EASE ABV WRNG THRESHOLDS THIS AFTN AND
THE MAGNITUDE OF THE BLSN IN AREAS IMPACTED BY THE LES SHOULD
SUBSIDE A BIT AS WELL. DID EXTEND THE GOING WRNG FOR A FEW HRS OVER
THE INTERIOR W HALF TO ACCOUNT FOR ADVY CRITERIA THAT WL PERSIST
THERE A BIT LONGER INTO THE AFTN.
TNGT...AS THE ARCTIC AIRMASS RETREATS FARTHER TO THE NE...THE PRES
GRADIENT/LLVL WINDS WL SLOWLY SLACKEN AND H85 TEMPS WL RISE TO ARND
-18C BY 12Z WED UNDER GENERAL SUBSIDENCE THAT WL SHARPEN AN INVRN
ARND 3-4K FT. EVEN THOUGH A SLOW WARMING WL ALLOW FOR IMPROVED SN
GROWTH...LOWERING INVRN BASE SHOULD LIMIT LES INTENSITY ESPECIALLY
OVER THE W. WL NOT EXTEND LES ADVYS BEYOND SCHEDULED EXPIRATION AT
00Z THIS EVNG GIVEN THE EXPECTED DIMINISHING SN TRENDS/WINDS THAT WL
ALSO DIMINISH THE MAGNITUDE OF THE BLSN/WIND CHILLS. ALTHOUGH H85
TEMPS WL MODERATE TNGT...SFC TEMPS MAY STILL PLUNGE SHARPLY AOB -20F
AWAY FM LK MODERATION WITH EXPECTATION THAT LARGER SCALE SUBSIDENCE
WL ALLOW FOR MOCLR SKIES IN THE PRESENCE OF LIGHTER WINDS. APRNT
TEMPS MAY REACH THE WIND CHILL ADVY CRITERIA...BUT OVERALL WINDS
SHOULD BE LIGHT ENUF TO JUSTIFY NO EXTENTION OF WIND CHILL HEADLINES
WHERE THE TEMPS FALL MORE SHARPLY AT THE MORE SHELTERED INTERIOR
LOCATIONS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 417 AM EST TUE JAN 7 2014
FOR WED/WED NIGHT...THE CWA WILL BE BETWEEN A SFC LOW MOVING E AND A
SFC HIGH MOVING IN FROM THE W. WHILE INVERSION HEIGHTS WILL
GRADUALLY LOWER THROUGH THE PERIOD...DO NOT EXPECT MUCH CHANGE IN
WNW-NW WIND LES WED AS WARMING TEMPS WILL PUT MORE OF THE LOW LEVELS
IN THE DGZ SO RATIOS WILL BE A BIT BETTER ALONG WITH A SHORTWAVE
MOVING NE OF THE CWA DURING THE AFTERNOON/EVENING WHICH WILL PROVIDE
SOME SYNOPTIC SUPPORT. THESE FACTORS WILL HELP OFFSET LOWERING
INVERSION HEIGHTS. FOR WED NIGHT...EXPECT LES TO LINGER MAINLY OVER
NE UPPER MI AS THE SFC HIGH MOVES S OF THE CWA WHILE DIMINISHING
OVERALL. DID NOT CHANGE FORECAST MUCH AS PREVIOUS FORECAST LOOKED
GOOD AND EXPECTATIONS HAVE NOT CHANGED SIGNIFICANTLY.
THU INTO EARLY SAT IS TRICKY AS A DISTURBANCE MOVES INTO THE PACIFIC
NW WED NIGHT...WITH NRN AND SRN JET STREAM INTERACTIONS CONTRIBUTING
TO THE SYSTEM STRENGTHENING OVER THE WRN CONUS. WITH THESE TYPES OF
NRN AND SRN STREAM INTERACTIONS...THE SITUATION IS ALWAYS MORE
UNCERTAIN AS MODELS HAVE TROUBLE HANDLING ENERGY ALLOCATION. AREA
WIDE SYSTEM SNOW IS A POSSIBILITY AS ENERGY LIFTS NE OUT OF THE
CENTRAL CONUS FRI INTO FRI NIGHT...BUT OVERALL CHANCES AND
DEFINITELY FINE DETAILS ARE FAR FROM CERTAIN. ONE THING MORE CERTAIN
IS THAT SW WINDS THU THROUGH FRI WILL RESULT AS THE HIGH EXITS E AND
THE TROUGH MOVES IN FROM THE W. MODELS ARE HINTING AT SW FLOW LES
OFF LAKE MICHIGAN...BUT WITH WARMING TEMPS AND THE NORMALLY TRICKY
NATURE OF LES IN THAT REGIME...WILL NOT ADD SIGNIFICANT EMPHASIS AT
THIS TIME. AHEAD OF THE TROUGH...MODELS INDICATE 850MB TEMPS
APPROACHING 0C FRI INTO EARLY SAT...WHICH WILL LEAD TO TEMPS RISING
CLOSER TO FREEZING FRI AND SAT.
SUN INTO MON ARE EVEN MORE UNCERTAIN AS MODELS INDICATE A QUICK
HITTING DISTURBANCE GENERALLY MOVING ALONG THE US/CANADIAN
BORDER...BUT DETAILS WITH THIS SYSTEM ARE FAR FROM CERTAIN...EVEN
GIVEN THE CURRENT GENERAL MODEL AGREEMENT. BEST THAT CAN BE SAID AT
THIS POINT IS THAT THERE IS POTENTIAL FOR A STRONGER SYSTEM TO MOVE
THROUGH OR NEAR THE REGION AND AT LEAST A QUICK SHOT OF WARMER TEMPS
AROUND FREEZING IS POSSIBLE. USED A GENERAL CONSENSUS OF GUIDANCE
FOR THIS PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1250 PM EST TUE JAN 7 2014
CMX...GUSTY WNW FLOW OF ARCTIC AIR WL BRING NEARLY CONTINUOUS
-SHSN/BLSN AND LIFR TO VLIFR CONDITIONS REMAINING. IN FACT VIS HAS
BEEN STUCK AT 1/4SM OR LESS SINCE 13Z. EXPECT A WEAKENING TREND
OVERALL...BUT IT WILL BE SLOW GOING. A NEARLY STEADY BAND OF LES
SHOWN ON THE VIS SATELLITE IMG SHOWN THAT IT IS MOVING SLIGHTLY N
THIS AFTERNOON. THE RESULT WILL BE MORE VARIABILITY IN THE
VIS/CEILINGS...WITH SLOW IMPROVEMENT LATE THIS AFTERNOON/OVERNIGHT
AS WINDS DIMINISH AND VIS IMPROVES. LARGER SCALE DRYING WILL QUICKLY
TAKE HOLD WEDNESDAY AFTERNOON.
IWD...MOST OF THE CLOUDS AND ASSOCIATED SNOW SHOWERS HAVE REMAINED
OFF SHORE...WITH VFR CEILINGS DOMINATING. THE POTENTIAL FOR MVFR
CEILINGS WILL LINGER THROUGH MID AFTERNOON...BEFORE LIGHTER WINDS
AND DRIER AIR SWINGS IN.
SAW...A SECONDARY BAND OF LIGHT SNOW SET UP ACROSS N CENTRAL UPPER
MI WILL KEEP THE POTENTIAL FOR MVFR CEILINGS AND A FEW LIGHT SNOW
SHOWERS AT SAW THROUGH LATE AFTERNOON...BEFORE VFR CEILINGS/VIS TAKE
HOLD AND REMAIN THROUGH THE PERIOD AS W-WNW WINDS KEEP THE FOCUS OF
LES TO THE W AND E.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 417 AM EST TUE JAN 7 2014
EXPECT NW GALES TO 35-40 KTS OVER PORTIONS OF THE EASTERN AND
CENTRAL LAKE TO DIMINISH TO 30 KTS BY THIS EVENING AS THE PRES
GRADIENT OVER THE UPPER LAKES SLACKENS...SO DROPPED THE GOING GALE
WARNING AT 00Z WED. ALTHOUGH WINDS/WAVES WILL SLOWLY DIMINISH THRU
TONIGHT...THE COMBINATION OF THE ARCTIC COLD AND SUFFICIENT WAVE
ACTION WILL RESULT IN CONTINUED WIDESPREAD HEAVY FREEZING SPRAY. A
HIGH PRESSURE SYSTEM MOVING THROUGH LATE WEDNESDAY INTO WEDNESDAY
NIGHT WILL DECREASE WINDS...CAUSING HEAVY FREEZING SPRAY TO DIMINISH.
AS THE HIGH EXITS EAST WHILE LOW PRESSURE MOVES IN FROM THE WEST ON
THURSDAY AND FRIDAY...EXPECT AN INCREASE IN WARMER SW WINDS INTO
EARLY SATURDAY. THE AREA OF LOW PRESSURE WILL PASS THROUGH EARLY
SATURDAY...LEADING TO WESTERLY WINDS THROUGH THE REST OF THE DAY
SATURDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL WARNING UNTIL 2 PM EST /1 PM CST/ THIS AFTERNOON FOR
MIZ002-004-005-009>011-084.
WIND CHILL ADVISORY UNTIL 1 PM EST /NOON CST/ WEDNESDAY FOR
MIZ002-004-005-009>011-084.
WIND CHILL ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR MIZ006-007-
014-085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR
MIZ001>003-006-007.
WIND CHILL ADVISORY UNTIL 2 PM EST /1 PM CST/ THIS AFTERNOON FOR
MIZ012-013.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 9 PM EST WEDNESDAY FOR LSZ266-
267.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR LSZ265-266.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ WEDNESDAY
FOR LSZ162-263>265.
HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST WEDNESDAY FOR
LSZ243>245-249>251.
HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST THIS EVENING FOR
LSZ248.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...KC
LONG TERM...TITUS
AVIATION...KF
MARINE...KC
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
442 PM CST TUE JAN 7 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 350 PM CST TUE JAN 7 2014
TEMPERATURES HAVE WARMED BACK ABOVE ZERO FOR MUCH OF THE AREA TODAY
THANKS TO SUNNY SKIES AND OUR SOMEWHAT OLD AND NON-PRISTINE SNOWPACK
WHICH HAS ALLOWED US TO MIX TO AROUND 925 MB. BUT OUR STAY ABOVE
ZERO WILL BE SHORT LIVED WITH PERHAPS THE COLDEST NIGHT OF THIS
COLD AIR OUTBREAK BEING POSSIBLE TONIGHT...ESPECIALLY FOR
WRN/CENTRAL MN. THE CULPRIT FOR THE COLD NIGHT TONIGHT IS THE 1030MB
HIGH UP IN SASKATCHEWAN THIS AFTERNOON THAT WILL BE SETTLING OVER MN
TONIGHT. THIS WILL GIVE US OUR FIRST GOOD OPPORTUNITY TO DECOUPLE
THE BOUNDARY LAYER UNDER MOSTLY CLEAR SKIES...SETTING UP IDEAL
RADIATIONAL COOLING CONDITIONS. THE ONLY POTENTIAL ISSUE? A STRIP OF
MID LEVEL CLOUDS THAT STRETCHES FROM THE TWIN CITIES BACK INTO
SOUTHEAST SASKATCHEWAN. A QUICK PEEK OUT THE WINDOW SHOWS THAT IR
SATELLITE IS EMBELLISHING THE THICKNESS OF THE CLOUD COVER A
BIT...AS IT IS A RATHER THIN ALTO CU DECK...SO WILL STICK WITH THE
IDEA OF THE RAP WITH THIS AREA OF CLOUDS DISSIPATING THIS EVENING AS
A REINFORCING SHOT OF SUBSIDENCE AND DRY AIR MOVES IN. WITH CLEARING
SKIES EXPECTED...FAVORED THE FORECAST TOWARD A BLEND OF THE BIAS
CORRECTED MAV/MET...WHICH RESULTED IN LOWS BETWEEN 28 AND 33 DEGREES
BELOW ZERO BASICALLY NORTHWEST OF A BENSON TO KANABEC LINE. UNDER
SIMILAR CONDITIONS THIS MORNING...LADYSMITH WAS ABLE TO DROP DOWN TO
-30...SO AS LONG AS THE MID LEVEL CLOUDS DON/T STICK AROUND FOR TOO
LONG...AM FAIRLY CONFIDENT IN SEEING TEMPS OF -30 OR COLDER IN OUR
TRADITIONAL COLD SPOTS LIKE BENSON AND LITTLE FALLS.
UNFORTUNATELY...WITH TEMPERATURES THIS COLD...IT WILL NOT TAKE MUCH
WIND TO SEE APPARENT TEMPERATURES CRASH TO BETWEEN 25 BELOW ZERO IN
SOUTHERN MN TO THE LOWER 40S BELOW ZERO ACROSS CENTRAL MN. WIND
SPEEDS ARE FORECAST TO BE 5 MPH OR LESS...SO WOULD HAVE PREFERRED TO
GO WITH NO WIND CHILL HEADLINES /DUE TO LACK OF WINDS/...BUT AFTER
COLLABORATION WITH NEIGHBORS HAVE GONE AHEAD AND ISSUED ANOTHER WIND
CHILL ADVISORY FOR TONIGHT INTO WEDNESDAY MORNING. HAVE APPARENT
TEMPERATURES WHERE FORECAST LOWS ARE CURRENTLY PROGGED TO BE COOLER
THAN -25 GETTING DOWN TO AROUND 40 BELOW...WHICH IS INTO WARNING
CRITERIA. HOWEVER...WITH WINDS EXPECTED TO BE LIGHT...DECIDED TO
STICK WITH THE ADVISORY...ESPECIALLY CONSIDERING THIS WILL BE
NOTHING LIKE WHAT WAS SEEN FROM SUNDAY NIGHT INTO MONDAY NIGHT.
FOR WEDNESDAY...WITH THE HIGH DIRECTLY OVERHEAD...WE WILL NOT SEE
MUCH MIXING...AS EVIDENCED BY NAM BUFR SOUNDINGS WHICH SHOW THE
BOUNDARY LAYER TODAY MIXING UP TO BETWEEN 900 AND 925 MB...BUT ONLY
MAKING IT TO 950MB OR LESS FOR WEDNESDAY. THIS WILL RESULT IN
WEDNESDAY BEING COOLER THAN WHAT WE ARE SEEING TODAY. AFTER BLENDING
IN BIAS CORRECTED MOS AND RAW MODEL DATA...ENDED UP WITH FORECAST
HIGHS ON WEDNESDAY ABOUT 2 TO 5 DEGREES COOLER THAN WHAT WE HAD BEEN
GOING WITH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 PM CST TUE JAN 7 2014
HIGH PRESSURE WILL KEEP THE UPPER MIDWEST DRY AND COLD FOR A FEW
MORE DAYS UNTIL SOUTHERLY FLOW BRINGS INCREASED MOISTURE...WARMER
TEMPERATURES...AND PRECIP CHANCES THIS WEEKEND.
AT THE START OF THE PERIOD HIGH PRESSURE WILL BE CENTERED ALONG THE
MN/WI BORDER...WITH CLEAR SKIES AND LIGHT WINDS SUPPORTING LOW
TEMPERATURES IN THE NEGATIVE 20S ACROSS WESTERN WISCONSIN AND
EASTERN MINNESOTA. THESE LOW TEMPERATURES SHOULD CLOSELY MIRROR
TONIGHTS. FARTHER WEST WARM AIR ADVECTION WILL WARM TEMPERATURES
OVERNIGHT...SO HAVE A NON- DIURNAL TREND IN PLACE. A PWAT FORECAST
OFF THE GFS 07.12 HAS 0.5 INCHES RETURNING ACROSS MINNESOTA...AND
AN INCH OF PRECIPITABLE WATER SOUTHEAST ACROSS THE WISCONSIN RIVER
VALLEY. THIS NORTHWARD MOISTURE FLUX IS AHEAD OF A LONGWAVE TROUGH
THAT WILL MOVE EASTWARD AND A WIDESPREAD AREA OF PRECIP ACROSS THE
EASTERN CONUS. AS OF NOW THE MAJORITY OF THE PRECIP WILL FALL EAST
OF I-35...SO CONTINUED WITH CHANCE POPS ACROSS THE SOUTHEASTERN
PORTIONS OF THE CWA. TEMPERATURES WILL MODERATE
CONSIDERABLY...WITH NEAR 30 FOR FRIDAY AND SATURDAY. SUNDAYS HIGHS
ARE CURRENTLY FORECAST TO BE IN THE MID 30S...BUT COULD SEE LOW
40S DEPENDING ON THE TIMING OF THE H850 THERMAL RIDGE.
CURRENTLY...THE EC 07.12 IS SLOWER THAN THE GFS AND WOULD FAVOR A
WARMER SOLUTION. FOR NOW HAVE A BLENDED GUIDANCE GIVEN THE
UNCERTAINTY...BUT THE POTENTIAL CERTAINLY EXISTS FOR A WARM
SUNDAY. ANOTHER CHANCE FOR SNOW EXISTS BEHIND THE COLD FRONT
SUNDAY NIGHT INTO MONDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 437 PM CST TUE JAN 7 2014
VFR THROUGH PERIOD. SOME HIGHER LEVEL MID CLOUD DROPPING SOUTH
OVER THE AREA DURING THE NIGHT. SOME SMALL CHANCE OF MVFR CIGS
BRUSHING THE FAR NORTHERN CWA LATER TONIGHT...BUT BELIEVE THIS
WILL GRADUALLY DRY UP OVERNIGHT. LIGHT W-NW WINDS BECOMING L/V
OVER THE WEST LATE TONIGHT INTO WEDNESDAY.
KMSP...HIGH CONFIDENCE FORECAST. VFR THROUGH PERIOD. LIGHT WINDS.
/OUTLOOK FOR KMSP/
THU...VFR. WINDS S 10 KTS.
FRI...VFR. CHC MVFR/-SN/-IP. WIND SSW 10 KTS.
SAT...VFR. WINDS SW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR MNZ041>045-
047>070-073>078-082>085-091>093.
WI...WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...DWE
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
356 PM CST TUE JAN 7 2014
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 350 PM CST TUE JAN 7 2014
TEMPERATURES HAVE WARMED BACK ABOVE ZERO FOR MUCH OF THE AREA TODAY
THANKS TO SUNNY SKIES AND OUR SOMEWHAT OLD AND NON-PRISTINE SNOWPACK
WHICH HAS ALLOWED US TO MIX TO AROUND 925 MB. BUT OUR STAY ABOVE
ZERO WILL BE SHORT LIVED WITH PERHAPS THE COLDEST NIGHT OF THIS
COLD AIR OUTBREAK BEING POSSIBLE TONIGHT...ESPECIALLY FOR
WRN/CENTRAL MN. THE CULPRIT FOR THE COLD NIGHT TONIGHT IS THE 1030MB
HIGH UP IN SASKATCHEWAN THIS AFTERNOON THAT WILL BE SETTLING OVER MN
TONIGHT. THIS WILL GIVE US OUR FIRST GOOD OPPORTUNITY TO DECOUPLE
THE BOUNDARY LAYER UNDER MOSTLY CLEAR SKIES...SETTING UP IDEAL
RADIATIONAL COOLING CONDITIONS. THE ONLY POTENTIAL ISSUE? A STRIP OF
MID LEVEL CLOUDS THAT STRETCHES FROM THE TWIN CITIES BACK INTO
SOUTHEAST SASKATCHEWAN. A QUICK PEEK OUT THE WINDOW SHOWS THAT IR
SATELLITE IS EMBELLISHING THE THICKNESS OF THE CLOUD COVER A
BIT...AS IT IS A RATHER THIN ALTO CU DECK...SO WILL STICK WITH THE
IDEA OF THE RAP WITH THIS AREA OF CLOUDS DISSIPATING THIS EVENING AS
A REINFORCING SHOT OF SUBSIDENCE AND DRY AIR MOVES IN. WITH CLEARING
SKIES EXPECTED...FAVORED THE FORECAST TOWARD A BLEND OF THE BIAS
CORRECTED MAV/MET...WHICH RESULTED IN LOWS BETWEEN 28 AND 33 DEGREES
BELOW ZERO BASICALLY NORTHWEST OF A BENSON TO KANABEC LINE. UNDER
SIMILAR CONDITIONS THIS MORNING...LADYSMITH WAS ABLE TO DROP DOWN TO
-30...SO AS LONG AS THE MID LEVEL CLOUDS DON/T STICK AROUND FOR TOO
LONG...AM FAIRLY CONFIDENT IN SEEING TEMPS OF -30 OR COLDER IN OUR
TRADITIONAL COLD SPOTS LIKE BENSON AND LITTLE FALLS.
UNFORTUNATELY...WITH TEMPERATURES THIS COLD...IT WILL NOT TAKE MUCH
WIND TO SEE APPARENT TEMPERATURES CRASH TO BETWEEN 25 BELOW ZERO IN
SOUTHERN MN TO THE LOWER 40S BELOW ZERO ACROSS CENTRAL MN. WIND
SPEEDS ARE FORECAST TO BE 5 MPH OR LESS...SO WOULD HAVE PREFERRED TO
GO WITH NO WIND CHILL HEADLINES /DUE TO LACK OF WINDS/...BUT AFTER
COLLABORATION WITH NEIGHBORS HAVE GONE AHEAD AND ISSUED ANOTHER WIND
CHILL ADVISORY FOR TONIGHT INTO WEDNESDAY MORNING. HAVE APPARENT
TEMPERATURES WHERE FORECAST LOWS ARE CURRENTLY PROGGED TO BE COOLER
THAN -25 GETTING DOWN TO AROUND 40 BELOW...WHICH IS INTO WARNING
CRITERIA. HOWEVER...WITH WINDS EXPECTED TO BE LIGHT...DECIDED TO
STICK WITH THE ADVISORY...ESPECIALLY CONSIDERING THIS WILL BE
NOTHING LIKE WHAT WAS SEEN FROM SUNDAY NIGHT INTO MONDAY NIGHT.
FOR WEDNESDAY...WITH THE HIGH DIRECTLY OVERHEAD...WE WILL NOT SEE
MUCH MIXING...AS EVIDENCED BY NAM BUFR SOUNDINGS WHICH SHOW THE
BOUNDARY LAYER TODAY MIXING UP TO BETWEEN 900 AND 925 MB...BUT ONLY
MAKING IT TO 950MB OR LESS FOR WEDNESDAY. THIS WILL RESULT IN
WEDNESDAY BEING COOLER THAN WHAT WE ARE SEEING TODAY. AFTER BLENDING
IN BIAS CORRECTED MOS AND RAW MODEL DATA...ENDED UP WITH FORECAST
HIGHS ON WEDNESDAY ABOUT 2 TO 5 DEGREES COOLER THAN WHAT WE HAD BEEN
GOING WITH.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 350 PM CST TUE JAN 7 2014
HIGH PRESSURE WILL KEEP THE UPPER MIDWEST DRY AND COLD FOR A FEW
MORE DAYS UNTIL SOUTHERLY FLOW BRINGS INCREASED MOISTURE...WARMER
TEMPERATURES...AND PRECIP CHANCES THIS WEEKEND.
AT THE START OF THE PERIOD HIGH PRESSURE WILL BE CENTERED ALONG THE
MN/WI BORDER...WITH CLEAR SKIES AND LIGHT WINDS SUPPORTING LOW
TEMPERATURES IN THE NEGATIVE 20S ACROSS WESTERN WISCONSIN AND
EASTERN MINNESOTA. THESE LOW TEMPERATURES SHOULD CLOSELY MIRROR
TONIGHTS. FARTHER WEST WARM AIR ADVECTION WILL WARM TEMPERATURES
OVERNIGHT...SO HAVE A NON- DIURNAL TREND IN PLACE. A PWAT FORECAST
OFF THE GFS 07.12 HAS 0.5 INCHES RETURNING ACROSS MINNESOTA...AND
AN INCH OF PRECIPITABLE WATER SOUTHEAST ACROSS THE WISCONSIN RIVER
VALLEY. THIS NORTHWARD MOISTURE FLUX IS AHEAD OF A LONGWAVE TROUGH
THAT WILL MOVE EASTWARD AND A WIDESPREAD AREA OF PRECIP ACROSS THE
EASTERN CONUS. AS OF NOW THE MAJORITY OF THE PRECIP WILL FALL EAST
OF I-35...SO CONTINUED WITH CHANCE POPS ACROSS THE SOUTHEASTERN
PORTIONS OF THE CWA. TEMPERATURES WILL MODERATE
CONSIDERABLY...WITH NEAR 30 FOR FRIDAY AND SATURDAY. SUNDAYS HIGHS
ARE CURRENTLY FORECAST TO BE IN THE MID 30S...BUT COULD SEE LOW
40S DEPENDING ON THE TIMING OF THE H850 THERMAL RIDGE.
CURRENTLY...THE EC 07.12 IS SLOWER THAN THE GFS AND WOULD FAVOR A
WARMER SOLUTION. FOR NOW HAVE A BLENDED GUIDANCE GIVEN THE
UNCERTAINTY...BUT THE POTENTIAL CERTAINLY EXISTS FOR A WARM
SUNDAY. ANOTHER CHANCE FOR SNOW EXISTS BEHIND THE COLD FRONT
SUNDAY NIGHT INTO MONDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1156 AM CST TUE JAN 7 2014
FAIRLY BENIGN TAF PERIOD IS ANTICIPATED...AS SFC RIDGE AXIS
OVERHEAD NOW WILL REPLACED BY...ANOTHER AREA OF HIGH PRESSURE
CURRENTLY WORKING SOUTH ACROSS THE CANADIAN PRAIRIE TONIGHT. LOW
CLOUDS OVER NRN MN WILL NOT COME MUCH FARTHER SOUTH THAN THEIR
CURRENT POSITION...AS CYCLONIC FLOW WILL REMAIN NORTH OF THE AREA
AS WELL...MEANING ITS MAINLY SCATTERED MID LEVEL CLOUDS WITH W TO
NW WINDS OF 5 KTS OR LESS FOR THE NEXT 30 HOURS.
KMSP...HIGH CONFIDENCE FORECAST...WITH NOT MUCH VARIATION
EXPECTED FROM CURRENT TAF.
/OUTLOOK FOR KMSP/
THU...VFR. WINDS S 10 KTS.
FRI...VFR. CHC MVFR/-SN/-IP. WIND SSW 10 KTS.
SAT...VFR. WINDS SW 5-10 KTS.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR MNZ041>045-
047>070-073>078-082>085-091>093.
WI...WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...MPG
LONG TERM...JRB
AVIATION...MPG
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 240 PM CST TUE JAN 7 2014
THE LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ARCTIC HIGH
PRESSURE CENTERED OVER THE GULF COAST...AND A RIDGE AXIS EXTENDING
NORTHEAST ACROSS THE PLAINS TO CENTRAL CANADA. AREAS OF LOW CLOUD
COVER CONTINUE TO FLOW SOUTHEAST AHEAD OF THE RIDGE AXIS FROM SOUTHERN
CANADA AND NORTHERN MINNESOTA AND INTO WISCONSIN...BUT THE LATEST
SATELLITE IMAGES SHOW THE STRATUS DISSIPATING AS IT MOVES INTO
NORTH-CENTRAL WISCONSIN. WITH PARTLY TO MOSTLY SUNNY
CONDITIONS...TEMPERATURES AND WIND CHILLS HAVE WARMED INTO THE
SINGLE DIGITS BELOW ZERO AND BETWEEN 20 TO 30 DEGREES BELOW ZERO
RESPECTIVELY. AS HIGH PRESSURE SHIFTS EAST INTO THE REGION OVER THE
NEXT 24 HOURS...TEMPS AND WIND CHILLS REMAIN THE MAIN FORECAST
CONCERNS...FOLLOWED BY CLOUDS.
TONIGHT...THE SURFACE RIDGE AXIS OVER THE NORTHERN MISSISSIPPI
VALLEY AND NORTHERN PLAINS WILL MOVE EAST TOWARDS THE STATE. AREAS OF LOW
STRATUS UPSTREAM WILL CONTINUE TO FLOW SOUTHEAST AHEAD OF THE
SURFACE HIGH WHICH MAKES CLOUD FORECAST PROBLEMATIC. DO NOT THINK
MODELS HAVE A GOOD HANDLE ON THIS CLOUD COVER...BUT DO INDICATE
DIMINISHING LOW LEVEL RH THAT WOULD POINT TOWARDS THIS CLOUD COVER
BREAKING UP. SO GENERALLY WENT WITH MOSTLY CLEAR TO PARTLY CLOUDY
CONDITIONS FOR THE EVENING...WITH A LITTLE HIGHER CLOUD COVER OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN...THEN SKY CONDITIONS TURNING
MOSTLY CLEAR EVERYWHERE OVERNIGHT. DUE TO THE INCOMING SURFACE
HIGH...WINDS WILL BE SUBSIDING TONIGHT...AND SOME POTENTIAL FOR
DECOUPLING OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. LOW LEVEL
WINDS WILL BE RIGHT ON THE CUSP...AND IF THIS OCCURS...LOW TEMPS
WILL BE SEVERAL DEGREES COLDER THAN IN THE GOING FORECAST. AS A
RESULT...DID SIDE WITH THE COLDER GUIDANCE BUT DID NOT GO WITH THE
COLDEST SOLUTIONS IN CASE DECOUPLING DID NOT OCCUR. THIS WOULD
PLACE LOW TEMPS MAINLY BETWEEN 10 AND 20 BELOW...WITH A FEW COLDER
SPOTS OVER N-C WISCONSIN...AND A FEW WARMER SPOTS NEAR THE LAKE
SHORE. WIND CHILLS WILL FALL TO 25 T0 35 DEGREES BELOW ZERO. WIND
CHILL ADVISORY HEADLINES WILL GO ON AS PLANNED...WITH THE CAVEAT
THAT SOME LOCATIONS MAY SEE A CALM WIND FOR A PERIOD LATE TONIGHT.
WEDNESDAY...HIGH PRESSURE WILL MOVE OVER THE AREA. TEMPERATURES
WILL CONTINUE THEIR SLOW MODERATION...AND WITH PLENTY OF
SUNSHINE...READINGS WILL RETURN TO THE SINGLE DIGITS ABOVE ZERO.
APPARENT TEMPS WILL RISE ABOVE ADVISORY CRITERIA BY LATE IN THE
MORNING...SO WILL RUN HEADLINES THROUGH 18Z.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 240 PM CST TUE JAN 7 2014
ARCTIC AIR MASS WITH SUB ZERO LOW TEMPERATURES WILL LINGER
WEDNESDAY NIGHT DUE TO ANTICIPATED CLEAR SKIES AND CALM WINDS UNDER
THE SURFACE HIGH PRESSURE SYSTEM.
ATTENTION THEN TURNS TO PCPN POTENTIAL LATE IN THE WEEK WITH THE
WAA FLOW. INITIAL WEAK SHORT WAVE PASSES JUST SOUTH OF THE AREA
THURSDAY INTO THURSDAY NIGHT. CONSIDERED ADDING A SLIGHT CHANCE OF
PCPN BUT UNSURE OF SATURATION FOR NOW. LATER SHIFTS CAN SOME ZL-
THURSDAY NIGHT IF WARRANTED.
MAIN SHORTWAVE TO PASS OVER LATER FRIDAY INTO FRIDAY EVENING WITH
PROGS INDICATED UP TO 0.25 WATER EQUIVALENT BY FRIDAY MIDNIGHT
OVER THE SOUTHEAST HALF OF THE FORECAST AREA. FORECAST SOUNDINGS
SUGGESTING A MIX OF ZR/S OVER MOST LOCATIONS AND THEREFORE HAS THE
POTENTIAL OF A HEADLINE FOR MIXED PCPN LATE THIS WEEK. HWO ALREADY
HIGHLIGHTING THIS CONCERN.
SURFACE RIDGE UNDER THE ZONAL FLOW REGIME TO END PCPN SATURDAY MORNING
WITH WAA PATTERN STARTING UP AGAIN SATURDAY NIGHT INTO SUNDAY. THE
FIRST IN A SERIES OF LOW PRESSURE SYSTEMS IS PROGGED TO TRACK
NORTH OF LAKE SUPERIOR LATE NEXT WEEKEND WILL DRAG A COOL FRONT
OVER THE AREA LATER SUNDAY INTO SUNDAY NIGHT...FOLLOWED WITH
ANOTHER CLIPPER SYSTEM NORTH OF THE REGION TOWARD TUESDAY. WILL
CONTINUE LOW END CHANCES OF PCPN WITH THE VARIOUS FROPAS.
FOR WHAT ITS WORTH...END PERIODS OF THE MEDIUM RANGE MODELS ARE
INDICATING SOME COLDER AIR TO WORK TOWARD THE GREAT LAKES REGION
LATE NEXT WEEKEND.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1119 AM CST TUE JAN 7 2014
SURFACE HIGH PRESSURE WILL BE BUILDING EAST INTO THE STATE THROUGH
THE TAF PERIOD. AREAS OF MVFR CLOUD COVER REMAIN OVER NORTHWEST
WISCONSIN...NORTHERN MINNESOTA...AND SOUTHERN CANADA WHICH WILL
CONTINUE TO GET PUSHED SOUTHEAST BY NORTHWEST WINDS. MODELS
INDICATE THAT THIS CLOUD COVER WILL DISSIPATE THIS EVENING...BUT NOT
SURE HOW WELL THE MODELS HAVE THIS HANDLED. WILL EXTEND THE TEMPO
MVFR GROUP TO LATE AFTERNOON...BUT MIGHT HAVE TO GET EXTENDED AGAIN
IF THE CLOUDS HOLD TOGETHER. IF THE CLOUDS DO BREAK UP AS
ANTICIPATED BY LATE TONIGHT...THEN VFR CONDITIONS ARE EXPECTED
THROUGH THE DAY TOMORROW.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST WEDNESDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......MPC