Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/05/14
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
353 PM MST FRI JAN 3 2014
.SHORT TERM...UPPER TROUGH STILL MOVING INTO NORTHERN GREAT
BASIN...BEGINNING TO SEE SOME INCREASE IN MOISTURE ACROSS THE
MOUNTAINS...THOUGH LOOKS TO BE ABOVE MOUNTAIN TOP. NO
PRECIPITATION CURRENTLY ACROSS MOUNTAINS...CLOSEST ACROSS
SOUTHWEST WYOMING AND NORTHERN UTAH. WINDS A BIT GUSTY IN AND NEAR
FOOTHILLS AND ACROSS THE HIGHER MOUNTAINS WITH MIXING AND
INCREASING NORTHWEST FLOW ALOFT AHEAD OF TROUGH. WESTERLY WINDS
HAVE SPREAD AS FAR EAST AS DIA WHICH HELPED TO WARM TEMPERATURES
TO NEAR 60. TROUGH WILL CONTINUE TO MOVE ACROSS THE NORTHERN GREAT
BASIN SOUTHWARD TOWARD COLORADO THIS EVENING AND INTO WESTERN
COLORADO OVERNIGHT. FLOW ALOFT TO BECOME A BIT MORE WESTERLY WITH
INCREASING MOISTURE ACROSS MOUNTAINS. OROGRAPHICS WILL IMPROVE BY
03Z ALONG WITH INCREASING MID LEVEL QG ASCENT AS JET SAGS
SOUTHWARD TOWARD COLORADO. SHOULD SEE SOME SNOW BEGIN TO DEVELOP
BY THE EVENING...ESPECIALLY ACROSS ZONE 31...THEN GRADUALLY BECOME
WIDESPREAD THROUGH THE EVENING WITH IMPROVING OROGRAPHICS AND
LIFT. MODELS SHOW AN INITIAL SHORTWAVE MOVING ACROSS THE MOUNTAINS
AROUND 06Z...WHICH WILL HELP WITH THE SNOWFALL. ALSO THE
APPROACHING JET WILL PROVIDE ADDITIONAL VERTICAL MOTION. GUSTY
WINDS WILL CREATE AREAS OF BLOWING SNOW BY MIDNIGHT...ESPECIALLY
ACROSS THE HIGHER MOUNTAIN PASSES. CURRENT HILITES STILL LOOK
REASONABLE...WITH THE HEAVIER AMOUNTS ACROSS ZONE 31. DID DELAY
THE ONSET OF THE ADVISORIES FOR ZONES 30..32..33 AND 34 UNTIL 03Z
BASED ON CURRENT CONDITIONS. ACROSS FOOTHILLS AND PLAINS...GUSTY
WINDS WILL PERSIST INTO THE EVENING IN AND NEAR FOOTHILLS BEFORE
DECREASING. COLD FRONT ASSOCIATED WITH THE UPPER TROUGH STILL
EXPECTED TO MOVE OUT OF WYOMING AROUND 06Z AND ACROSS THE DENVER
AREA BY 09Z. UPSLOPE WILL THEN DEVELOP AROUND 12Z. LOW LEVEL
MOISTURE TO GRADUALLY INCREASE WITH A CHANCE OF LIGHT SNOW IN AND
NEAR THE FOOTHILLS BY MORNING AS LIFT INCREASES. ON
SATURDAY...UPPER TROUGH WILL MOVE ACROSS THE AREA THROUGH THE DAY.
THE COMBINATION OF GOOD OROGRAPHICS AND MID LEVEL QG ASCENT WITH
JET IN VICINITY WILL CONTINUE TO PROVIDE SNOW FOR THE MOUNTAINS.
WILL CONTINUE WITH THE CURRENT HILITES THROUGH THE AFTERNOON. FOR
FOOTHILLS AND PLAINS...INCREASING UPSLOPE AND MID LEVEL ASCENT
WILL BRING A DECENT SHOT OF SNOW TO MOST LOCATIONS...MAINLY IN AND
NEAR FOOTHILLS. LATEST MODELS STILL SHOWING AMOUNTS IN THE 1 TO 4
INCH RANGE. NAM ON THE LOW END...GFS THE HIGHER END ACROSS THE
DENVER AREA SOUTH OVER THE PALMER DIVIDE. THERE IS STILL SOME
CHANCE FOR A BAND OF HEAVIER SNOW SETTING UP SOMEWHERE ACROSS THE
AREA BY THE AFTERNOON AND COULD HELP PRODUCE MORE SNOW. FOR NOW
WILL CONTINUE WITH THE LOWER AMOUNTS AND WILL WAIT TO SEE WHAT
DEVELOPS BEFORE ISSUING ANY ADVISORIES. AIRMASS TO BE COLDER...
WITH TEMPERATURES STRUGGLING TO GET TO THE MIDDLE 20S ACROSS
PLAINS.
.LONG TERM...THE AMS WILL BECOME INCREASINGLY SUBSIDENT SATURDAY
NIGHT AS THE STORM SYSTEM MOVES TO THE EAST. A STRONG
NORTHWESTERLY FLOW WILL BE OVER THE STATE ON SUNDAY WITH THE UPPER
LEVEL JETSTREAM OVER COLORADO. A WEAK DISTURBANCE EMBEDDED IN THE
FLOW ALOFT WILL BRUSH ACROSS NORTHEAST COLORADO AROUND 00Z MONDAY.
WITH THE JET OVERHEAD...THERE IS THE POTENTIAL FOR SOME BANDED
SNOWFALL OVER THE NORTHEAST PLAINS...BUT MDLS NOT DEVELOPING MUCH
QPF AT THIS TIME SO WL STICK TO SLGT CHC POPS. IN THE MOUNTAINS
AND FOOTHILLS...GUSTY NORTHWEST WINDS SO WL ADD AREAS OF BLOWING
SNOW TO THE GRIDS. OVERALL SNOW AMOUNTS WILL BE LIGHT IN THE
MOUNTAINS DUE TO INCREASING STABILITY. A SECONDARY SURGE OF COLD
AIR SUNDAY EVENING...WL KEEP THE NORTHEAST PLAINS LOCKED IN THE
FREEZER THROUGH MONDAY. THE FLOW ALOFT WILL WEAKEN AND BECOME MORE
WESTERLY BY TUESDAY AS A RIDGE OF HIGH PRESSURE BUILDS IN FROM
THE WEST. TEMPERATURES WILL MODIFY THROUGH MID WEEK. A WEAK SYSTEM
MAY MOVE ACROSS COLORADO ON WEDNESDAY BUT SNOWFALL WILL LIKELY BE
CONFINED TO THE MOUNTAIN AREAS. IT WILL BE DRY AGAIN ON THURSDAY
WITH A SHORT WAVE RIDGE OVER COLORADO...FOLLOWED BY ANOTHER
POTENTIAL TROUGH THURSDAY NIGHT INTO FRIDAY. FOR NOW WL KEEP THE
MENTION OF SNOW CONFINED TO THE MOUNTAINS FOR THE END OF NEXT
WEEK.
&&
.AVIATION...WESTERLY WINDS CONTINUE ACROSS AREA AIRPORTS...WITH
GUSTS TO 35 KTS AT BJC. WINDS STILL EXPECTED TO GRADUALLY WEAKEN
THROUGH THE EVENING. LATEST RAP INDICATING WINDS SHIFTING TO THE
NORTHWEST BY 02Z. THERE IS A CHANCE THAT DRAINAGE WINDS COULD
DEVELOP AT KDEN AND KAPA DURING THE EVENING BEFORE SHIFTING TO THE
NORTHWEST AFTER 06Z. WILL TREND THE TAFS IN THAT DIRECTION.
MOISTURE TO GRADUALLY INCREASE THROUGH EVENING AND
OVERNIGHT...WITH CEILINGS ABOVE 10000 FEET AGL. FRONT STILL
EXPECTED TO MOVE ACROSS THE DENVER AREA AROUND 09Z WITH GUSTY
NORTHERLY WINDS. CEILINGS WILL GRADUALLY LOWER AS UPSLOPE DEVELOPS
BY 12Z ALONG WITH AREAS OF LIGHT SNOW. THE SNOW WILL CONTINUE
THROUGH THE DAY SATURDAY WITH IFR CONDITIONS PREVAILING.
CONDITIONS TO GRADUALLY IMPROVE AFTER 00Z AS UPSLOPE WEAKENS. SNOW
ACCUMULATION OF 2 TO 4 INCHES STILL EXPECTED FOR AREA
AIRPORTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM MST
SUNDAY FOR COZ033-034.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM MST
SATURDAY FOR COZ030-032.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM MST SUNDAY
FOR COZ031.
&&
$$
SHORT TERM...D-L
LONG TERM....COOPER
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
958 AM MST FRI JAN 3 2014
.UPDATE...
&&
.SHORT TERM...MIXING HAS COMMENCED IN AND NEAR FOOTHILLS WITH
GUSTY WESTERLY WINDS MOST AREAS. GRADIENT ACROSS STATE FROM GRAND
JUNCTION TO DENVER HAS INCREASED TO 10.27 MB. SOME GUSTS TO 40
MPH BEING REPORTED AT KBJC AS WELL AS ALONG THE FOOTHILLS OF
JEFFERSON COUNTY. SHOULD SEE WINDS CONTINUE TO INCREASE IN AND
NEAR FOOTHILLS AS WELL AS ACROSS THE MOUNTAINS THROUGH THE
AFTERNOON AHEAD OF APPROACHING UPPER TROUGH AND JET. LATEST RAP
CROSS SECTIONS SHOW CROSS MOUNTAIN FLOW INCREASING TO AROUND 60
KTS AT MOUNTAIN TOP BY 00Z. MODELS KEEP THE STRONGEST WINDS IN AND
NEAR MOUNTAIN TOP THROUGH THE EVENING. SO NOT EXPECTING WINDS TO
EXCEED HIGH WIND CRITERIA. STILL...WOULD SUSPECT THERE WILL BE
SOME GUSTS TO 60 MPH ACROSS THE RIDGES AS WELL AS WIND PRONE AREAS
OF THE FOOTHILLS. WILL BOOST THE WINDS A BIT IN THE GRIDS THROUGH
THIS EVENING IN AND NEAR FOOTHILLS. UPPER TROUGH STILL MOVING INTO
NORTHERN GREAT BASIN WITH SOME MID AND HIGH LEVEL MOISTURE
SPREADING ACROSS UTAH AND WESTERN WYOMING. MOISTURE WILL BE
GRADUALLY INCREASING ACROSS THE MOUNTAINS THROUGH THE DAY...THOUGH
CROSS SECTIONS KEEP MOISTURE ABOVE MOUNTAIN TOP. LATEST RAP SHOWS
SOME QPF ACROSS ZONE 31 AROUND 00Z. WILL BE BACKING OFF ON THE
CHANCES FOR SNOW THIS AFTERNOON FOR THE MOUNTAINS. MOISTURE TO
THEN DEEPEN THIS EVENING AS TROUGH MOVES INTO THE GREAT BASIN AND
OROGRAPHICS IMPROVE. SHOULD BE A GOOD SHOT OF SNOW FOR THE
MOUNTAINS AND HIGH VALLEYS OVERNIGHT INTO SATURDAY. HILITES LOOK
FINE. TIMING OKAY FOR NOW...AS SNOW SHOULD BE ON THE INCREASE
AFTER 00Z.
.AVIATION...GUSTY WESTERLY WINDS ONGOING AT KBJC WITH
GUSTS TO 35 KTS. SOUTHWESTERLIES ONGOING AT KDEN AND KAPA. THE
WESTERLY WINDS WILL SPREAD EAST ACROSS THE AREA AROUND 20 OR 21Z
WITH POSSIBLE GUSTS TO 22 KTS AT KDEN AND KAPA. WINDS TO THEN
SHIFT TO THE NORTHWEST AROUND 01Z. CURRENT TAFS SHOW THIS TREND
AND STILL LOOKS REASONABLE. WILL CONTINUE FOR THE UPCOMING
ISSUANCE. SOME INCREASE IN MID AND HIGH LEVEL MOISTURE BY THE
EVENING...CEILINGS TO REMAIN UNRESTRICTED. FRONT EXPECTED TO MOVE
ACROSS AREA AROUND 09Z WITH GUSTY NORTHERLY WINDS. CEILINGS TO
LOWER BY 11Z WITH SNOW DEVELOPING. SNOW TO CONTINUE THROUGH THE
DAY SATURDAY WITH IFR CONDITIONS PREVAILING. AT THIS TIME...SNOW
ACCUMULATIONS BY SATURDAY EVENING LOOK TO BE IN THE 2 TO 4 INCH
RANGE.
&&
.PREV DISCUSSION... /ISSUED 354 AM MST FRI JAN 3 2014/
SHORT TERM...WARM CONDITIONS ARE EXPECTED TODAY AS WESTERLY
DOWNSLOPE WINDS CONTINUE AHEAD OF TONIGHTS PASSING UPPER LEVEL
DISTURBANCE. WEST WINDS OVER THE WESTERN DENVER SUBURBS HAVE
HELPED TO KEEP TEMPERATURES IN THE UPPER 30S TO MID 40S THIS
MORNING. ELSEWHERE ON THE PLAINS...LOWS HAVE DROPPED AS LOW AS THE
MID TEENS AND LOWER 20S. AFTER SUNRISE...THE AIRMASS SHOULD BECOME
WELL MIXED WITH HIGHS WARMING TO THE MID AND UPPER 50S ACROSS
NORTHEAST COLORADO. MOUNTAIN AREAS SHOULD SEE TEMPERATURES CLOSER
TO SEASONAL NORMALS AS CLOUDS BEGIN INCREASING BY AFTERNOON. THE
FOOTHILLS AND MOUNTAIN RIDGES SHOULD SEE GUSTY WINDS THROUGH THE
DAY BECAUSE OF THE STRONG NORTHWEST FLOW IN PLACE OVER THE STATE.
CROSS SECTIONS SHOW THAT THE HIGHEST WINDS ARE EXPECTED TO REMAIN
OVER THE FOOTHILLS AND HIGHER TERRAIN. A FEW FAVORED LOCATIONS ON
THE PLAINS MAY SEE SOME GUSTY WINDS AT TIMES...BUT NO HIGHLIGHTS
ARE NECESSARY.
TONIGHT WILL SEE BIG CHANGES SPREAD ACROSS THE FORECAST AREA FROM
THE NORTHWEST AS A SHORT WAVE TROUGH MOVES OVER THE STATE. A
STRONG COLD FRONT WILL ACCOMPANY THE UPPER LEVEL SYSTEM AND MOVE
FROM THE WYOMING BORDER TO THE PALMER DIVIDE BETWEEN MIDNIGHT AND
6 AM. ALOFT...THE UPPER DISTURBANCE IS BEING DRIVEN BY A VERY
STRONG JET WHICH WILL AID IN PRODUCING VERICAL MOTIONS AND BANDED
PRECIPITATION FIELDS. MOUNTAIN AREAS SHOULD SEE OROGRAPHIC
PRECIPITATION BEGINNING LATE IN THE AFTERNOON OR DURING THE
EVENING. ONCE PRECIPITATION BEGINS IN THE MOUNTAINS...IT SHOULD
CONTINUE FOR 24 TO 36 HOURS WITH SIGNIFICANT ACCUMULATIONS
POSSIBLE. WILL ISSUE WINTER WEATHER ADVISORIES FOR ZONES
30...32...33 AND 34 AND A WINTER STORM WARNING FOR ZONE 31 WHERE
AMOUNTS WILL BE HEAVIEST.
LONG TERM...AN UPPER LEVEL TROUGH WILL MOVE SE ACROSS THE AREA ON
SAT AS UPSLOPE FLOW DEVELOPS BEHIND A STG CDFNT. COMBINATION OF
FAVORABLE MID LEVEL QG ASCENT THRU THE AFTN HOURS AND AXIS OF
UPPER LEVEL JET SAGGING ACROSS THE AREA SHOULD LEAD TO A DECENT
SHOT OF SNOW IN MOST AREAS. APPEARS BANDED PCPN WILL BE ALONG THE
CO-WY BORDER AT 12Z AND THEN SHIFT SOUTHWARD THRU THE AFTN HOURS
WITH BAND EXITING SRN AREAS OF CWA BY LATE AFTN. GFS IS CERTAINLY
THE MOST AGGRESSIVE WITH SNOW AMOUNTS ON SAT WITH ADVISORY
CRITERIA (3 TO 6 INCHES) OVER THE URBAN CORRIDOR EASTWARD ACROSS
THE PLAINS WITHIN A 12 HOUR WINDOW WHILE THE OTHER MODELS ARE MORE
IN THE 1 TO 3 INCH RANGE. IF BANDED PCPN DOES OCCUR AND MOISTURE
DEPTH IS DEEPER THEN GFS MAY END BE CORRECT WITH SNOW AMOUNTS.
HOWEVER FOR NOW WILL LET DAY SHIFT DECIDE IF AMOUNTS WILL REACH
ADVISORY CRITERIA OVER NERN CO. IN THE MTNS AMOUNTS MAY REACH
WARNING CRITERIA IN ZN 31 WITH HIGH END ADVISORY AMOUNTS IN ZNS 33
AND 34 THRU SAT NIGHT. WINDS WILL BE GUSTY AT TIMES AS WELL SO
WILL SEE BLOWING SNOW OVER THE HIGHER PASSES. HIGHER VALLEYS IN
ZNS 30 AND 32 MAY REACH ADVISORY CRITERIA AS WELL ON SAT DUE TO
BANDED PCPN SO WILL INCLUDE THEM AS WELL. HIGHS ON SAT WILL STAY
IN THE 20S OVER NERN CO.
BY SAT NIGHT THE UPSLOPE FLOW WILL WEAKEN WITH MID LVL DESCENT OVER
THE AREA. THUS SNOW CHANCES SHOULD DECREASE ACROSS NERN CO. IN THE
MTNS OROGRAPHICS WILL REMAIN FAVORABLE SAT NIGHT ALTHOUGH STABILITY
WILL INCREASE SO ADDITIONAL ACCUMULATIONS WILL GENERALLY STAY ON
THE LIGHT SIDE. ON SUN STG NW FLOW ALOFT WILL REMAIN OVER THE AREA
AS ANOTHER DISTURBANCE POSSIBLY AFFECTS THE AREA. OROGRAPHICS WILL
REMAIN FAVORABLE IN THE MTNS HOWEVER MOISTURE DEPTH WILL DECREASE
SOME SO LIGHT ACCUMULATIONS WILL CONTINUE WITH AREAS OF BLOWING
SNOW. AT LOWER ELEVATIONS ANOTHER SHOT OF COLD AIR WILL MOVE INTO
NERN CO SUN AFTN WITH UPSLOPE FLOW DEVELOPING ALONG WITH AN
INCREASE IN MOISTURE. AS THE STG UPPER LEVEL JET MOVES ACROSS SUN
AFTN INTO SUN EVENING THERE COULD BE ANOTHER PERIOD OF BANDED PCPN
OVER PORTIONS OF NERN CO PROBABLY NORTH OF A DENVER TO LIMON LINE.
SINCE THIS IS STILL PRETTY FAR OUT FOR NOW WILL JUST MENTION A
SLIGHT CHC OF SNOW. HIGHS COULD END UP BEING COLDER THAN SAT OVER
NERN CO AS READINGS MAY STRUGGLE TO GET ABV 20.
FOR MON THE FLOW ALOFT WILL BEGIN TO WEAKEN AS A STG UPPER LEVEL
TROUGH RESIDES OVER THE CENTRAL AND EASTERN US. CURRENT CROSS-
SECTIONS SHOW MUCH DRIER AIR SPREADING ACROSS THE AREA SO WILL NOT
MENTION ANY POPS. AS FAR AS HIGHS WILL KEEP READINGS IN THE 20S
ALTHOUGH AREAS OVER THE FAR ERN PLAINS MAY STILL STRUGGLE TO GET ABV
20. BY TUE WNW FLOW ALOFT WILL CONTINUE WITH MODELS NOT SHOWING
MUCH MOISTURE THRU THE AFTN HOURS SO WILL ONLY MENTION LOW POPS IN
THE MTNS. HIGHS SHOULD BEGIN TO MODERATE OVER NERN CO WITH READINGS
RISING BACK INTO THE 30S. FOR WED A WEAK UPPER LEVEL TROUGH MAY
AFFECT THE AREA BRINGING A CHC OF SNOW TO THE MTNS. OVER NERN CO
WILL KEEP FCST DRY WITH TEMPS NEAR SEASONAL LEVELS.
AVIATION...KDEN AND KAPA SHOULD SEE A CONTINUATION OF SOUTHERLY
WINDS THIS MORNING TRANSITIONING TO WESTERLY BY LATE MORNING AND
EARLY AFTERNOON. SOME GUSTS TO ABOUT 20 KNOTS WILL BE POSSIBLE
LATE IN THE AFTERNOON. AT KBJC...WEST WINDS HAVE ALREADY SPREAD
ACROSS THE NORTHERN PARTS OF JEFFERSON COUNTY. WIND GUSTS UP TO 30
KNOTS WILL CONTINUE MUCH OF THE DAY. CEILINGS AND VISIBILITIES
WILL REMAIN UNRESTRICTED THROUGH THIS EVENING. LATER TONIGHT...
STILL EXPECT COLD FRONT TO MOVE ACROSS THE DENVER AREA AFTER 2 AM
WITH LOWERING CEILINGS AND SNOWFALL DEVELOPING BY SUNRISE TOMORROW
MORNING. IFR CONDITIONS AND ACCUMULATING SNOWFALL SHOULD BE
EXPECTED ALL DAY SATURDAY.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 AM MST
SUNDAY FOR COZ033-034.
WINTER WEATHER ADVISORY FROM 5 PM THIS AFTERNOON TO 5 PM MST
SATURDAY FOR COZ030-032.
WINTER STORM WARNING FROM 5 PM THIS AFTERNOON TO 5 AM MST SUNDAY
FOR COZ031.
&&
$$
SHORT TERM...D-L
LONG TERM....RPK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS NEW YORK NY
624 AM EST FRI JAN 3 2014
.SYNOPSIS...
A POTENT STORM SYSTEM TRACKS INTO THE CANADIAN MARITIMES AS ARCTIC
HIGH PRESSURE BUILDS IN THROUGH TONIGHT. HIGH PRESSURE BUILDS
OFFSHORE ON SATURDAY AHEAD OF A COLD FRONT MOVING ACROSS THE UPPER
MIDWEST AND GREAT LAKES. A WAVE OF LOW PRESSURE THEN FORMS ALONG
THE FRONT OVER THE TENNESSEE VALLEY ON SUNDAY...TRACKING NORTHEAST
INTO EASTERN CANADA ON MONDAY. AS IT DOES SO...IT WILL SEND AN
ARCTIC COLD FRONT THROUGH THE REGION IN THE MORNING. HIGH PRESSURE
BUILDS TO THE SOUTH AND WEST OF THE REGION THROUGH MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
990 HPA LOW WAS LOCATED ABOUT 190 MILES SE OF KMTP AT 11Z. LOW
LEVEL FRONTOGENETIC FORCING TO THE NW OF THE LOW PRODUCING SNOW
BANDS ACROSS CENTRAL AND EASTERN CT AND LONG ISLAND...WITH LIGHTER
SNOW TO THE WEST. SNOW WILL TAPER OFF FROM W TO E THIS MORNING BY
AROUND 7 AM OVER FAR WESTERN ZONES 8-9AM AT NYC AND BY 10-11AM OVER
FAR EASTERN ZONES.
STILL ON TRACK FOR 8-12 INCHES ACROSS LONG ISLAND AND 6 TO 10
INCHES ELSEWHERE WITH LOCALLY HIGHER AMOUNTS.
THERE IS STILL SOME INDICATION THAT COULD HAVE A LINGERING
DEFORMATION BAND OVER EASTERN LONG ISLAND INTO EARLY AFTERNOON -
BUT FOR NOW DO NOT THINK WILL ADD MUCH TO ACCUMULATION. WILL NEED
TO MONITOR THIS FEATURE THOUGH - AS SOMETIMES THEY ARE GOOD FOR AN
EXTRA INCH OR TWO OF SNOWFALL.
EVEN AS SNOW SHUTS DOWN - STRONG N-NE WINDS GUSTING TO 30-45 MPH
WILL CAUSING BLOWING OF THE DRY POWDERY SNOW AND VERY LOW WIND CHILLS
- WITH VALUES 15 TO AROUND 20 BELOW ZERO ACROSS NORTHERN INTERIOR
ZONES AND 5 TO AROUND 10 BELOW ELSEWHERE INTO THE EARLY AFTERNOON
HOURS. AS A RESULT HAVE LEFT THE WINTER WEATHER HEADLINES AS IS.
WINDS DIMINISH THIS AFTERNOON - WITH WIND CHILLS INCREASING TO FROM
-10 TO AROUND 0.
FOR HIGHS TODAY TOOK A BLEND OF MIXING DOWN FROM 925 HPA PER BUFKIT
SOUNDINGS WITH NAM AND RUC 2-METER TEMPERATURES AND A BLEND OF
MAV/MET GUIDANCE. EXPECT VALUES DURING THE TEENS TODAY - WITH
MOST HIGHS FOR THE DAY REACHED JUST AFTER MIDNIGHT - AND THE
WARMEST TEMPERATURES DURING THE DAYLIGHT HOURS LIKELY DURING THE
MORNING HOURS.
RECORD LOW TEMPERATURES AND RECORD LOW MAXIMUM TEMPERATURES ARE
LIKELY TODAY AT SOME CLIMATE SITES. SEE THE CLIMATE SECTION OF THE
AFD FOR DETAILS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
MAINLY CLEAR SKY CONDITIONS IN THE WAKE OF THE DEPARTING LOW
COUPLED WITH SNOW COVER AND DIMINISHING WINDS WILL ALLOW FOR LOWS
TO PLUMMET TONIGHT. LOWS WILL BE MAINLY FROM 5 ABOVE TO AROUND 10
BELOW - COLDEST ACROSS THE NORTHERN TIER. THIS AROUND 20-25
DEGREES BELOW NORMAL - AND CONSISTENT WITH TAKING THE LOWEST OF
MAV/MET/NAM 2-METER TEMPERATURES AND BLENDING 2 PARTS OF THIS AND
1 PART OF A BLEND OF MAV/MET/NAM 2-METER TEMPERATURES. THIS
INSURES THAT THE FORECAST LOWS ARE COLDER THAN A BLEND OF GUIDANCE
- HOWEVER NAM 2-METER TEMPERATURES ACROSS THE INTERIOR SEEMED
EXCESSIVELY COLD - ESPECIALLY ACROSS INTERIOR CT.
THESE WILL BE NEAR RECORD VALUES AT SOME LOCATIONS. REFER TO THE
CLIMATE SECTION OF THE AFD FOR DETAILS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A PROGRESSIVE...YET AMPLIFIED FLOW WILL CONTINUE THROUGH NEXT WEEK
WITH ANOTHER FULL LATITUDE TROF MOVING THROUGH THE EAST EARLY NEXT
WEEK. WITH NO REAL BLOCK...A NEUTRAL NAO AND PNA...COLD AIR COMES IN
WITH A FURY EARLY NEXT WEEK...BUT ALSO QUICKLY LIFTS OUT IN THE MID
WEEK PERIOD.
MODELS DIFFER IN THE TIMING OF THE COLD FRONT ON MONDAY...WITH THE
NAM WRF ON THE FASTER END OF THE SUITE...WITH THE GFS TAKING THE
MIDDLE ROAD APPROACH...AND THE ECMWF LAGGING JUST BEHIND. GEFS AND
SREF LEANING TOWARD THE FASTER SOLUTIONS. PREFERENCE RIGHT NOW WAS
TO NOT BREAK MUCH FROM CONTINUITY WITH THE DIFFERENCES IN THE
MODELS...PREFERRING A FRONTAL PASSAGE CLOSE TO DAYBREAK MON.
WARM ADVECTION RAINS DEVELOP SUN AFT...PRIMARILY FROM NYC POINTS
NORTH AND WEST...WITH MOST OF THE AREA SEEING WIDESPREAD RAIN
SUN NIGHT INTO MON MORNING. THERMO PROFILES SUPPORT AN ALL RAIN
EVENT AS COLD AIR LAGS SUFFICIENTLY BEHIND THE FRONT.
STRONG COLD ADVECTION ENSUES FROM MON MORNING INTO TUE...WITH A
PIECE OF THE POLAR VORTEX BREAKING OFF ACROSS THE OHIO VALLEY AND
WORKING EAST ACROSS THE AREA ON TUE. 85H TEMPS ON TUE WILL BE AROUND
-25 DEGREES F. THIS WILL RESULT IN HIGHS TUE ONLY IN THE SINGLE
DIGITS INLAND AND THE LOWER TO MID TEENS ALONG THE COAST. ALSO OF
NOTE IS THAT WINDS WILL CONTINUE TO BE GUSTY FROM A WESTERLY
DIRECTION MONDAY THROUGH WEDNESDAY. WIND CHILLS FORECAST COULD REACH
0 TO -10 DEGREES F AT TIMES LATE MONDAY NIGHT THROUGH EARLY
WEDNESDAY.
AIRMASS GRADUALLY MODERATES WED INTO THU AS HIGH PRESSURE BUILDS TO
THE SOUTH AND EAST.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
***HIGH IMPACT WINTER STORM THROUGH THIS MORNING***
MODERATE TO LOCALLY HEAVY SNOW AND BLOWING/DRIFTING SNOW...WITH
MOSTLY IFR CONDS AND MAXIMUM SNOWFALL RATES OF ABOUT AN INCH PER
HOUR PER HOUR...SHOULD CONTINUE UNTIL ABOUT 11Z-12Z. ALTHOUGH
FALLING SNOW SHOULD THEN TAPER OFF FROM 11Z-14Z FROM WEST TO
EAST...BLOWING/DRIFTING SNOW WILL CONTINUE TO IMPACT THE
TERMINALS WITH AT LEAST MVFR VSBYS INTO EARLY AFTERNOON.
CONDS WILL IMPROVE TO VFR THEREAFTER. TOTAL SNOW ACCUMULATIONS
WILL RANGE FROM 6-8 INCHES AT KSWF...TO 8-10 INCHES OVER WESTERN
TERMINALS AND FROM 8-10 INCHES OVER EASTERN LONG
ELSEWHERE...HIGHEST ACROSS LONG ISLAND.
NORTH WINDS 15-25 KT WITH GUSTS 25-35 KT...HIGHEST AT THE NYC
METRO AND LONG ISLAND TERMINALS...WILL BACK NW A LITTLE LATER THAN
ORIGINALLY EXPECTED...BY ABOUT 14Z-15Z. NW WINDS 20 KT WITH GUSTS
25-30 KT WILL THEN CONTINUE FOR MUCH OF THE DAY...THEN DIMINISH TO
10 KT OR LESS AFTER SUNSET.
NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
KLGA FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
KEWR FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
KHPN FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
KISP FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
.OUTLOOK FOR 06Z SAT THROUGH TUE...
.LATE TONIGHT...VFR WITH LIGHT NW WINDS.
.SAT-SAT NIGHT...VFR. SW WINDS LESS THAN 10 KT.
.SUNDAY...MVFR CONDS POSSIBLE IN THE AFTERNOON...WITH RAIN/SNOW
ACROSS THE INTERIOR AND RAIN AT THE NYC METRO/LONG ISLAND/COASTAL
CT TERMINALS.
.SUNDAY NIGHT-MON MORNING...IFR CONDS LIKELY IN RAIN. S WINDS
G20-30KT LATE SUNDAY NIGHT/MON MORNING.
.MON AFTERNOON-TUE...CONDS IMPROVING TO VFR. W WINDS G20-30 KT.
&&
.MARINE...
MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. FORECAST APPEARS ON TRACK.
THE HIGHEST WINDS WITH THIS STORM WILL OCCUR EARLY THIS MORNING AS
THE STORM CENTER DEEPENS WHILE PASSING SE OF THE 40N/70W BENCHMARK.
GALES ARE STILL EXPECTED ON ALL WATERS AT LEAST THROUGH THE MORNING
HOURS. IT IS POSSIBLE THAT THE WESTERN WATERS FALL BELOW GALE
WARNING CRITERIA BY AROUND NOON TODAY AND THERE IS A CHANCE THAT ALL
WATERS SUBSIDE BELOW GALES BY LATE AFTERNOON. WITH NOT ENOUGH
CONFIDENCE TO TRIM BACK THE GALE WARNING...WILL KEEP THE GALE
WARNING AS IS...LASTING THROUGH THIS AFTERNOON.
FOR THIS EVENING...SCA CONDITIONS ON ALL WATERS TO START...BUT
QUICKLY SUBSIDING. ONLY THE OCEAN WATERS WILL PROBABLY STILL HAVE
SCA CONDITIONS BY MIDNIGHT TONIGHT AND ONLY BECAUSE OF SEAS.
SUB-SCA CONDITIONS COULD BE POSSIBLE BY SUNRISE ON SATURDAY ON THE
OCEAN...IF NOT...SEAS SHOULD SUBSIDE BELOW 5 FT BY MID-MORNING.
SUB SCA SAT MORNING INCREASES TO SCA SOUTHEAST OF LI LATE SAT
THROUGH SUN MORNING. THIS WILL BE MAINLY ACROSS THE EASTERN OCEAN
ZONES. A BRIEF RETURN TO BELOW SCA CONDITIONS WILL BE FOLLOWED BY
ANOTHER ROUND OF SCA SUNDAY NIGHT INTO NEXT WEEK AS A STRONG COLD
FRONT IMPACTS THE AREA. A PROLONGED PERIOD OF WESTERLY WINDS MON
INTO WED WILL PRODUCE ROUGH SEAS AND NEAR GALE FORCE GUSTS ON THE
OCEAN WATERS.
&&
.HYDROLOGY...
AN ADDITIONAL 1/10 TO 4/10 OF AN INCH OF LIQUID EQUIVALENT WILL
FALL MAINLY THIS MORNING...ALL AS SNOW.
ANOTHER WIDESPREAD SIGNIFICANT PRECIP EVENT IS POSSIBLE SUNDAY
THROUGH EARLY MONDAY...MOSTLY IN THE FORM OF RAIN. THE HEAVY RAIN
COULD COMBINE WITH RESIDUAL SNOW COVER TO PRODUCE SOME MINOR
FLOODING. GENERAL ESTIMATES OF EVENT TOTAL LIQUID AMOUNTS FROM A
MODEL CONSENSUS ARE AROUND 0.5 TO 1 INCH.
&&
.TIDES/COASTAL FLOODING...
ALTHOUGH WINDS WILL BE OFFSHORE FOR SEVERAL HOURS BEFORE THE HIGH
TIDE CYCLE OCCURS THE MORNING TO EARLY AFTERNOON...IT APPEARS THAT
TIDAL PILING WILL BE MAIN FACTOR FOR COASTAL FLOODING WITH THIS
CYCLE. ANOTHER FACTOR IS THAT THIS WILL BE THE HIGHER OF THE TWO
DAILY ASTRONOMICAL TIDE CYCLES.
THE STEVENS INSTITUTE GUIDANCE HAS BEEN THE BETTER PERFORMER WITH
THIS STORM SO FAR AND WHEN FACTORING IN AN EXTRA RESIDUAL (NOTING
RECENT OBSERVATIONS) ON TOP OF ITS SURGE GUIDANCE...IT APPEARS
LIKELY THAT THERE WILL BE WIDESPREAD MINOR COASTAL FLOODING WITH
THIS UPCOMING TIDE CYCLE. HOWEVER...WITH HIGH WAVES AND A SE SWELL
FOR A GOOD PORTION LEADING UP TO THE MID-MORNING HOURS...THE
SOUTH-SHORE BACK BAYS OF NASSAU AND QUEENS WILL PROBABLY EXPERIENCE
MODERATE COASTAL FLOODING. IT IS ALSO NOT OUT OF THE QUESTION FOR
LOCALLY MODERATE COASTAL FLOODING FOR THE PARTS OF THE LOWER
HARBOR...BUT THINKING IS THAT ANY MODERATE FLOODING WOULD BE JUST
ISOLATED.
WITH THIS SAID...WILL BE GOING WITH A COASTAL FLOOD ADVISORY FOR ALL
COASTAL ZONES WITH THE EXCEPTION OF SOUTHERN NASSAU AND QUEENS WHERE
A COASTAL FLOOD WARNING WILL BE WARRANTED. ALSO...NO HEADLINES FOR
SOUTHERN NEW LONDON COUNTY AS THEY LIKELY FALL SHORT OF MINOR
THRESHOLDS.
THERE IS A REASONABLE CHANCE HOWEVER SOUTHERN NASSAU AND
QUEENS DON/T EXPERIENCE WIDESPREAD MODERATE FLOODING...AND INSTEAD
JUST HAVE MINOR FLOODING. IT IS ALSO POSSIBLE THAT PARTS OF SOUTHERN
MIDDLESEX COUNTY DO NOT EVEN REACH MINOR COASTAL FLOODING.
NOT EXPECTING ANY COASTAL FLOODING ISSUES WITH TONIGHT/S HIGH TIDE
CYCLE AS IT WILL BE THE LOWER OF THE TWO TIDE CYCLES AND TIDAL
PILING WOULD NO LONGER BE A FACTOR.
&&
.CLIMATE...
CLIMATE RECORDS FOR JANUARY 3:
LOCATION RECORD LOW HIGH FORECAST VALUE
BRIDGEPORT...CT 16 1981 17
ISLIP...NY 20 2008 13
LAGUARDIA...NY 17 1981 18
JFK AIRPORT...NY 22 2008/1981 17
NYC-CENTRAL PARK...NY 12 1918 16
NEWARK...NJ 19 1981 17
LOCATION RECORD LOW FORECAST VALUE
BRIDGEPORT...CT 9 2008 9
ISLIP...NY 7 2001 10
LAGUARDIA...NY 12 1981 7
JFK AIRPORT...NY 14 2008 11
NYC-CENTRAL PARK...NY -4 1879 8
NEWARK...NJ 10 1981 8
CLIMATE RECORDS FOR JANUARY 4:
LOCATION RECORD LOW FORECAST VALUE
BRIDGEPORT...CT -1 1981 1
ISLIP...NY 10 2008 2
LAGUARDIA...NY 4 1981 2
JFK AIRPORT...NY 8 1981 3
NYC-CENTRAL PARK...NY -3 1981 2
NEWARK...NJ 1 1981 1
&&
.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...COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 2 PM EST
THIS AFTERNOON FOR CTZ009>011.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
CTZ005>012.
NY...COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 2 PM EST
THIS AFTERNOON FOR NYZ071-073-078-079-176-177.
BLIZZARD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NYZ078>081-
177-179.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ067>075-176-178.
COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR NYZ072-
074-075.
COASTAL FLOOD WARNING UNTIL 11 AM EST THIS MORNING FOR NYZ178-
179.
COASTAL FLOOD ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ080-081.
NJ...WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ002-
004-006-103>108.
COASTAL FLOOD ADVISORY UNTIL 11 AM EST THIS MORNING FOR NJZ006-
106-108.
MARINE...GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ330-335-338-
340-345-350-353-355.
&&
$$
SYNOPSIS...MALOIT/DW
NEAR TERM...MALOIT/PW
SHORT TERM...MALOIT/PW
LONG TERM...DW
AVIATION...GOODMAN
MARINE...JC/MALOIT/DW
HYDROLOGY...MALOIT/DW
TIDES/COASTAL FLOODING...
CLIMATE...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
422 AM EST FRI JAN 3 2014
.SYNOPSIS...
A POTENT STORM SYSTEM TRACKS INTO THE CANADIAN MARITIMES AS ARCTIC
HIGH PRESSURE BUILDS IN THROUGH TONIGHT. HIGH PRESSURE BUILDS
OFFSHORE ON SATURDAY AHEAD OF A COLD FRONT MOVING ACROSS THE UPPER
MIDWEST AND GREAT LAKES. A WAVE OF LOW PRESSURE THEN FORMS ALONG
THE FRONT OVER THE TENNESSEE VALLEY ON SUNDAY...TRACKING NORTHEAST
INTO EASTERN CANADA ON MONDAY. AS IT DOES SO...IT WILL SEND AN
ARCTIC COLD FRONT THROUGH THE REGION IN THE MORNING. HIGH PRESSURE
BUILDS TO THE SOUTH AND WEST OF THE REGION THROUGH MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
992 HPA LOW WAS LOCATED ABOUT 225 SE OF KMTP AT 8Z. LOW LEVEL
FRONTOGENETIC FORCING TO THE NW OF THE LOW PRODUCING SNOW BANDS ACROSS
THE NYC METRO AND LONG ISLAND EARLY THIS MORNING. BASED ON BANDING A
BIT MORE WIDESPREAD THAN EXPECTED AND TEMPERATURES A TAD COLDER THAN
FORECAST PROMOTING SLIGHTLY HIGHER SNOW TO LIQUID RATIOS...HAVE UPPED
SNOW FALL TOTALS TO 8-12 INCHES ACROSS LONG ISLAND AND 6-10 ACROSS
THE NEW YORK CITY/NE NJ/S WESTCHESTER.
SNOW SHOULD TAPER OFF FROM W TO E BY AROUND MID MORNING BASED ON
TIMING OF BACK EDGE OF SNOW ON RADAR. SOME INDICATION THAT COULD
HAVE A LINGERING DEFORMATION BAND OVER EASTERN LONG ISLAND INTO
EARLY AFTERNOON - BUT FOR NOW DO NOT THINK WILL ADD MUCH TO
ACCUMULATION. WILL NEED TO MONITOR THIS FEATURE THOUGH - AS
SOMETIMES THEY ARE GOOD FOR AN EXTRA INCH OR TWO OF SNOWFALL.
EVEN AS SNOW SHUTS DOWN - STRONG N-NE WINDS GUSTING TO 30-45 MPH
WILL CAUSING BLOWING OF THE DRY POWDERY SNOW AND VERY LOW WIND CHILLS
- WITH VALUES 15 TO 20 BELOW ZERO ACROSS NORTHERN INTERIOR ZONES AND
5 TO 10 BELOW ELSEWHERE INTO THE EARLY AFTERNOON HOURS. AS A RESULT
HAVE LEFT THE WINTER WEATHER HEADLINES AS IS.
WINDS DIMINISH THIS AFTERNOON - WITH WIND CHILLS INCREASING TO FROM
-10 TO AROUND 0.
FOR HIGHS TODAY TOOK A BLEND OF MIXING DOWN FROM 925 HPA PER BUFKIT
SOUNDINGS WITH NAM AND RUC 2-METER TEMPERATURES AND A BLEND OF
MAV/MET GUIDANCE. EXPECT VALUES DURING THE TEENS TODAY - WITH
MOST HIGHS FOR THE DAY REACHED JUST AFTER MIDNIGHT - AND THE
WARMEST TEMPERATURES DURING THE DAYLIGHT HOURS LIKELY DURING THE
MORNING HOURS.
RECORD LOW TEMPERATURES AND RECORD LOW MAXIMUM TEMPERATURES ARE
LIKELY TODAY AT SOME CLIMATE SITES. SEE THE CLIMATE SECTION OF THE
AFD FOR DETAILS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM SATURDAY/...
MAINLY CLEAR SKY CONDITIONS IN THE WAKE OF THE DEPARTING LOW
COUPLED WITH SNOW COVER AND DIMINISHING WINDS WILL ALLOW FOR LOWS
TO PLUMMET TONIGHT. LOWS WILL BE MAINLY FROM 5 ABOVE TO AROUND 10
BELOW - COLDEST ACROSS THE NORTHERN TIER. THIS AROUND 20-25
DEGREES BELOW NORMAL - AND CONSISTENT WITH TAKING THE LOWEST OF
MAV/MET/NAM 2-METER TEMPERATURES AND BLENDING 2 PARTS OF THIS AND
1 PART OF A BLEND OF MAV/MET/NAM 2-METER TEMPERATURES. THIS
INSURES THAT THE FORECAST LOWS ARE COLDER THAN A BLEND OF GUIDANCE
- HOWEVER NAM 2-METER TEMPERATURES ACROSS THE INTERIOR SEEMED
EXCESSIVELY COLD - ESPECIALLY ACROSS INTERIOR CT.
THESE WILL BE NEAR RECORD VALUES AT SOME LOCATIONS. REFER TO THE
CLIMATE SECTION OF THE AFD FOR DETAILS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
A PROGRESSIVE...YET AMPLIFIED FLOW WILL CONTINUE THROUGH NEXT WEEK
WITH ANOTHER FULL LATITUDE TROF MOVING THROUGH THE EAST EARLY NEXT
WEEK. WITH NO REAL BLOCK...A NEUTRAL NAO AND PNA...COLD AIR COMES IN
WITH A FURY EARLY NEXT WEEK...BUT ALSO QUICKLY LIFTS OUT IN THE MID
WEEK PERIOD.
MODELS DIFFER IN THE TIMING OF THE COLD FRONT ON MONDAY...WITH THE
NAM WRF ON THE FASTER END OF THE SUITE...WITH THE GFS TAKING THE
MIDDLE ROAD APPROACH...AND THE ECMWF LAGGING JUST BEHIND. GEFS AND
SREF LEANING TOWARD THE FASTER SOLUTIONS. PREFERENCE RIGHT NOW WAS
TO NOT BREAK MUCH FROM CONTINUITY WITH THE DIFFERENCES IN THE
MODELS...PREFERRING A FRONTAL PASSAGE CLOSE TO DAYBREAK MON.
WARM ADVECTION RAINS DEVELOP SUN AFT...PRIMARILY FROM NYC POINTS
NORTH AND WEST...WITH MOST OF THE AREA SEEING WIDESPREAD RAIN
SUN NIGHT INTO MON MORNING. THERMO PROFILES SUPPORT AN ALL RAIN
EVENT AS COLD AIR LAGS SUFFICIENTLY BEHIND THE FRONT.
STRONG COLD ADVECTION ENSUES FROM MON MORNING INTO TUE...WITH A
PIECE OF THE POLAR VORTEX BREAKING OFF ACROSS THE OHIO VALLEY AND
WORKING EAST ACROSS THE AREA ON TUE. 85H TEMPS ON TUE WILL BE AROUND
-25 DEGREES F. THIS WILL RESULT IN HIGHS TUE ONLY IN THE SINGLE
DIGITS INLAND AND THE LOWER TO MID TEENS ALONG THE COAST. ALSO OF
NOTE IS THAT WINDS WILL CONTINUE TO BE GUSTY FROM A WESTERLY
DIRECTION MONDAY THROUGH WEDNESDAY. WIND CHILLS FORECAST COULD REACH
0 TO -10 DEGREES F AT TIMES LATE MONDAY NIGHT THROUGH EARLY
WEDNESDAY.
AIRMASS GRADUALLY MODERATES WED INTO THU AS HIGH PRESSURE BUILDS TO
THE SOUTH AND EAST.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
***HIGH IMPACT WINTER STORM THROUGH THIS MORNING***
MODERATE TO LOCALLY HEAVY SNOW AND BLOWING/DRIFTING SNOW...WITH
MOSTLY IFR CONDS AND MAXIMUM SNOWFALL RATES OF ABOUT AN INCH PER
HOUR PER HOUR...SHOULD CONTINUE UNTIL ABOUT 11Z-12Z. ALTHOUGH
FALLING SNOW SHOULD THEN TAPER OFF FROM 11Z-14Z FROM WEST TO
EAST...BLOWING/DRIFTING SNOW WILL CONTINUE TO IMPACT THE
TERMINALS WITH AT LEAST MVFR VSBYS INTO EARLY AFTERNOON.
CONDS WILL IMPROVE TO VFR THEREAFTER. TOTAL SNOW ACCUMULATIONS
WILL RANGE FROM 6-8 INCHES AT KSWF...TO 8-10 INCHES OVER WESTERN
TERMINALS AND FROM 8-10 INCHES OVER EASTERN LONG
ELSEWHERE...HIGHEST ACROSS LONG ISLAND.
NORTH WINDS 15-25 KT WITH GUSTS 25-35 KT...HIGHEST AT THE NYC
METRO AND LONG ISLAND TERMINALS...WILL BACK NW A LITTLE LATER THAN
ORIGINALLY EXPECTED...BY ABOUT 14Z-15Z. NW WINDS 20 KT WITH GUSTS
25-30 KT WILL THEN CONTINUE FOR MUCH OF THE DAY...THEN DIMINISH TO
10 KT OR LESS AFTER SUNSET.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS
CAN BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KJFK FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
KLGA FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
KEWR FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH
IMPLIES SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KTEB FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
KHPN FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
KISP FCSTER COMMENTS: AMD LIKELY AFTER 12Z TO FINE TUNE WINDS AND
FLIGHT CAT AS SNOW ENDS BUT AS BLOWING SNOW CONTINUES.
.OUTLOOK FOR 06Z SAT THROUGH TUE...
.LATE TONIGHT...VFR WITH LIGHT NW WINDS.
.SAT-SAT NIGHT...VFR. SW WINDS LESS THAN 10 KT.
.SUNDAY...MVFR CONDS POSSIBLE IN THE AFTERNOON...WITH RAIN/SNOW
ACROSS THE INTERIOR AND RAIN AT THE NYC METRO/LONG ISLAND/COASTAL
CT TERMINALS.
.SUNDAY NIGHT-MON MORNING...IFR CONDS LIKELY IN RAIN. S WINDS
G20-30KT LATE SUNDAY NIGHT/MON MORNING.
.MON AFTERNOON-TUE...CONDS IMPROVING TO VFR. W WINDS G20-30 KT.
&&
.MARINE...
THE HIGHEST WINDS WITH THIS STORM WILL OCCUR EARLY THIS MORNING AS
THE STORM CENTER DEEPENS WHILE PASSING SE OF THE 40N/70W BENCHMARK.
GALES ARE STILL EXPECTED ON ALL WATERS AT LEAST THROUGH THE MORNING
HOURS. IT IS POSSIBLE THAT THE WESTERN WATERS FALL BELOW GALE
WARNING CRITERIA BY AROUND NOON TODAY AND THERE IS A CHANCE THAT ALL
WATERS SUBSIDE BELOW GALES BY LATE AFTERNOON. WITH NOT ENOUGH
CONFIDENCE TO TRIM BACK THE GALE WARNING...WILL KEEP THE GALE
WARNING AS IS...LASTING THROUGH THIS AFTERNOON.
FOR THIS EVENING...SCA CONDITIONS ON ALL WATERS TO START...BUT
QUICKLY SUBSIDING. ONLY THE OCEAN WATERS WILL PROBABLY STILL HAVE
SCA CONDITIONS BY MIDNIGHT TONIGHT AND ONLY BECAUSE OF SEAS.
SUB-SCA CONDITIONS COULD BE POSSIBLE BY SUNRISE ON SATURDAY ON THE
OCEAN...IF NOT...SEAS SHOULD SUBSIDE BELOW 5 FT BY MID-MORNING.
SUB SCA SAT MORNING INCREASES TO SCA SOUTHEAST OF LI LATE SAT
THROUGH SUN MORNING. THIS WILL BE MAINLY ACROSS THE EASTERN OCEAN
ZONES. A BRIEF RETURN TO BELOW SCA CONDITIONS WILL BE FOLLOWED BY
ANOTHER ROUND OF SCA SUNDAY NIGHT INTO NEXT WEEK AS A STRONG COLD
FRONT IMPACTS THE AREA. A PROLONGED PERIOD OF WESTERLY WINDS MON
INTO WED WILL PRODUCE ROUGH SEAS AND NEAR GALE FORCE GUSTS ON THE
OCEAN WATERS.
&&
.HYDROLOGY...
AN ADDITIONAL 1/10 TO 4/10 OF AN INCH OF LIQUID EQUIVALENT WILL
FALL MAINLY THIS MORNING...ALL AS SNOW.
ANOTHER WIDESPREAD SIGNIFICANT PRECIP EVENT IS POSSIBLE SUNDAY
THROUGH EARLY MONDAY...MOSTLY IN THE FORM OF RAIN. THE HEAVY RAIN
COULD COMBINE WITH RESIDUAL SNOW COVER TO PRODUCE SOME MINOR
FLOODING. GENERAL ESTIMATES OF EVENT TOTAL LIQUID AMOUNTS FROM A
MODEL CONSENSUS ARE AROUND 0.5 TO 1 INCH.
&&
.TIDES/COASTAL FLOODING...
ALTHOUGH WINDS WILL BE OFFSHORE FOR SEVERAL HOURS BEFORE THE HIGH
TIDE CYCLE OCCURS THE MORNING TO EARLY AFTERNOON...IT APPEARS THAT
TIDAL PILING WILL BE MAIN FACTOR FOR COASTAL FLOODING WITH THIS
CYCLE. ANOTHER FACTOR IS THAT THIS WILL BE THE HIGHER OF THE TWO
DAILY ASTRONOMICAL TIDE CYCLES.
THE STEVENS INSTITUTE GUIDANCE HAS BEEN THE BETTER PERFORMER WITH
THIS STORM SO FAR AND WHEN FACTORING IN AN EXTRA RESIDUAL (NOTING
RECENT OBSERVATIONS) ON TOP OF ITS SURGE GUIDANCE...IT APPEARS
LIKELY THAT THERE WILL BE WIDESPREAD MINOR COASTAL FLOODING WITH
THIS UPCOMING TIDE CYCLE. HOWEVER...WITH HIGH WAVES AND A SE SWELL
FOR A GOOD PORTION LEADING UP TO THE MID-MORNING HOURS...THE
SOUTH-SHORE BACK BAYS OF NASSAU AND QUEENS WILL PROBABLY EXPERIENCE
MODERATE COASTAL FLOODING. IT IS ALSO NOT OUT OF THE QUESTION FOR
LOCALLY MODERATE COASTAL FLOODING FOR THE PARTS OF THE LOWER
HARBOR...BUT THINKING IS THAT ANY MODERATE FLOODING WOULD BE JUST
ISOLATED.
WITH THIS SAID...WILL BE GOING WITH A COASTAL FLOOD ADVISORY FOR ALL
COASTAL ZONES WITH THE EXCEPTION OF SOUTHERN NASSAU AND QUEENS WHERE
A COASTAL FLOOD WARNING WILL BE WARRANTED. ALSO...NO HEADLINES FOR
SOUTHERN NEW LONDON COUNTY AS THEY LIKELY FALL SHORT OF MINOR
THRESHOLDS.
THERE IS A REASONABLE CHANCE HOWEVER SOUTHERN NASSAU AND
QUEENS DON/T EXPERIENCE WIDESPREAD MODERATE FLOODING...AND INSTEAD
JUST HAVE MINOR FLOODING. IT IS ALSO POSSIBLE THAT PARTS OF SOUTHERN
MIDDLESEX COUNTY DO NOT EVEN REACH MINOR COASTAL FLOODING.
NOT EXPECTING ANY COASTAL FLOODING ISSUES WITH TONIGHT/S HIGH TIDE
CYCLE AS IT WILL BE THE LOWER OF THE TWO TIDE CYCLES AND TIDAL
PILING WOULD NO LONGER BE A FACTOR.
&&
.CLIMATE...
CLIMATE RECORDS FOR JANUARY 3:
LOCATION RECORD LOW HIGH FORECAST VALUE
BRIDGEPORT...CT 16 1981 18
ISLIP...NY 20 2008 17
LAGUARDIA...NY 17 1981 18
JFK AIRPORT...NY 22 2008/1981 18
NYC-CENTRAL PARK...NY 12 1918 17
NEWARK...NJ 19 1981 18
LOCATION RECORD LOW FORECAST VALUE
BRIDGEPORT...CT 9 2008 9
ISLIP...NY 7 2001 10
LAGUARDIA...NY 12 1981 7
JFK AIRPORT...NY 14 2008 11
NYC-CENTRAL PARK...NY -4 1879 8
NEWARK...NJ 10 1981 8
CLIMATE RECORDS FOR JANUARY 4:
LOCATION RECORD LOW FORECAST VALUE
BRIDGEPORT...CT -1 1981 1
ISLIP...NY 10 2008 2
LAGUARDIA...NY 4 1981 2
JFK AIRPORT...NY 8 1981 3
NYC-CENTRAL PARK...NY -3 1981 2
NEWARK...NJ 1 1981 1
&&
.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...COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 2 PM EST
THIS AFTERNOON FOR CTZ009>011.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
CTZ005>012.
NY...COASTAL FLOOD ADVISORY FROM 10 AM THIS MORNING TO 2 PM EST
THIS AFTERNOON FOR NYZ071-073-078-079-176-177.
BLIZZARD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NYZ078>081-
177-179.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ067>075-176-178.
COASTAL FLOOD ADVISORY FROM 7 AM TO 11 AM EST THIS MORNING FOR
NYZ072-074-075.
COASTAL FLOOD WARNING FROM 7 AM TO 11 AM EST THIS MORNING FOR
NYZ178-179.
COASTAL FLOOD ADVISORY FROM 9 AM THIS MORNING TO 1 PM EST THIS
AFTERNOON FOR NYZ080-081.
NJ...WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ002-
004-006-103>108.
COASTAL FLOOD ADVISORY FROM 7 AM TO 11 AM EST THIS MORNING FOR
NJZ006-106-108.
MARINE...GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ330-335-338-
340-345-350-353-355.
&&
$$
SYNOPSIS...MALOIT/DW
NEAR TERM...MALOIT/PW
SHORT TERM...MALOIT/PW
LONG TERM...DW
AVIATION...GOODMAN
MARINE...JC/DW
HYDROLOGY...MALOIT/DW
TIDES/COASTAL FLOODING...
CLIMATE...MALOIT/LN
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
157 AM EST FRI JAN 3 2014
.SYNOPSIS...
DEEPENING LOW PRESSURE PASSES TO THE SOUTH TONIGHT...THEN DEPARTS
TO THE EAST FRIDAY. HIGH PRESSURE BUILDS FRIDAY NIGHT. HIGH
PRESSURE WILL MOVE EAST AND OFFSHORE THIS WEEKEND WITH ANOTHER LOW
DEVELOPING ALONG THE APPALACHIANS SUNDAY. THIS WILL DEEPEN TO THE
WEST OF THE REGION WITH A COLD FRONT MOVING ACROSS MONDAY. ANOTHER
ARCTIC AIR MASS BUILDS IN BEHIND IT AS WESTERN CANADA HIGH PRESSURE
BUILDS TO THE SOUTH AND WEST OF THE REGION THROUGH MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
TEMPERATURES ARE FALLING OFF MORE RAPIDLY THAN FORECAST - HAVE
ADJUSTED DOWNWARD BASED ON HRRR 2-M TEMPERATURES WHICH SEEM TO AVE
BEST HANDLE ON CURRENT TRENDS. AS A RESULT - COULD END UP WITH
SLIGHTLY HIGHER SNOW TO LIQUID RATIOS - SO ADDED LOCALLY HIGHER
AMOUNTS POSSIBLE TO THE WSW TEXT.
SPS OUT FOR SNOW BAND IMPACTING S NASSAU AND SUFFOLK - WITH RATES
1-2 INCH/HR. WILL MONITOR AND UPDATE AMOUNTS IF NEEDED.
AT 4Z A 996 HPA LOW WAS LOCATED ABOUT 210 MILES S OF KMTP LIFTING
NNE PER LATEST PRESSURE FALLS...WITH RAPID DEEPENING EXPECTED TO
CONTINUE. WITH THE STEEP PRESSURE FALLS DUE EXPECT WINDS TO
CONTINUE TO INCREASE OVER THE AREA. DEPENDING ON HOW WINDS AND
VISIBILITIES TREND - THERE IS A CHANCE FOR A SHORT FUSED EXPANSION
OF THE BLIZZARD WARNING - WITH MOST LIKELY CANDIDATES BEING SE CT
AND POSSIBLY NYC. EXPECT HEAVIEST SNOWFALL ACROSS THE AREA
GENERALLY THROUGH 9Z THEN A TAPERING OFF FROM W TO E.
MODEL OUTPUT FOR TONIGHT REMAINS FAIRLY CLOSE...WITH GFS AND
ECMWF A BIT WETTER THAN NAM/WRF.
SREF ENSEMBLE WOULD SUGGEST A QPF BLEND IS PERHAPS THE WAY TO GO AT
THIS TIME. QPF OF AROUND 1/2 INCH TO 3/4 OF AN INCH IS EXPECTED.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SATURDAY/...
VERY COLD AIR THIS TIME FRAME.
MORNING SNOW ENDS FROM WEST TO EAST AS THE UPPER TROUGH PIVOTS
ACROSS THE NORTHEAST AND THE DEEPENING COASTAL LOW DEPARTS. SNOW
ACCUMULATIONS 5 TO 10 INCHES...WITH PERHAPS SOME HIGHER AMOUNTS OVER LI
PER LOW TRACK/HEAVIEST SNOW CLIMATOLOGY.
WINDY CONDITIONS WILL RESULT IN BLOWING SNOW THROUGH THE MORNING AND
INTO THE AFTERNOON.
SKIES CLEAR DURING THE AFTERNOON...AGAIN FROM WEST TO EAST.
TEMPS RISE LITTLE DURING THE DAY...AND IN FACT REMAIN NEARLY STEADY
BEFORE DROPPING LATER IN THE DAY. MAX TEMPS IN THE TEENS EXPECTED.
FOR FRIDAY NIGHT...A RIDGE OF HIGH PRESSURE BUILDS IN. AS WINDS
LIGHTEN AND SKIES REMAIN CLEAR...TEMPS WILL PLUMMET INTO THE SINGLE
DIGITS AND BELOW ZERO ACROSS THE REGION. WENT CLOSER TO COLDER MAV
DATA...WHICH MAY NOT EVEN BE COLD ENOUGH AS MOS TRENDS TOWARD CLIMATOLOGY
AND DOES NOT USUALLY HANDLE IMPACTS OF A FRESH SNOW PACK WELL.
HOWEVER...SOME WAA MID AND HIGH CLOUDS APPROACH LATE AT
NIGHT...WHICH COULD HAVE A MINOR IMPACT ON TEMPS.
&&
.LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/...
THE JET STREAM LIFTS GRADUALLY NORTH OF THE REGION THIS WEEKEND BUT
WILL DIVE BACK SOUTH OF THE REGION FOR NEXT WEEK. A RIDGING TREND IN
THE MID LEVELS MUCH OF THE WEEKEND WITH DECREASING HEIGHTS SUNDAY
AFTERNOON INTO NEXT WEEK WITH A MUCH COLDER AIR MASS APPROACHING.
AT THE SURFACE...THE ARCTIC HIGH PRESSURE WILL BE CENTERED ACROSS
THE REGION SATURDAY MORNING AND WILL PUSH OFFSHORE THROUGH THE DAY.
THIS WILL CONTINUE TO MOVE EAST THROUGH THE WEEKEND...WITH A
CONTINUANCE OF RETURN SOUTHERLY FLOW. THE RESULT WILL BE A
MODERATION OF THE AIR MASS...ALTHOUGH WITH LIMITED MIXING HEIGHTS
SATURDAY...ONLY TO BETWEEN 1000 AND 950 MB. HIGHS ARE FORECAST TO
STILL BE ABOUT 10 DEGREES BELOW NORMAL.
THE MODERATION WILL BE MORE REMARKABLE AT NIGHT...ESPECIALLY ALONG
THE COAST WITH THE INCREASINGLY ONSHORE FLOW AS HIGH PRESSURE
CONTINUE TO MOVES OFFSHORE. LOWS SATURDAY NIGHT ARE FORECAST TO BE
CLOSER TO NORMAL BUT STILL LIKELY BELOW NORMAL ACROSS THE INTERIOR
WITH LIGHTER WINDS THERE.
A REMARKABLE REBOUND IN TEMPERATURES FOR SUNDAY WITH THE CONTINUED
RETURN SOUTHERLY FLOW. HOWEVER...TEMPERATURES FREEZING OR BELOW IN
THE MORNING WITH NEXT WAVE OF LOW PRESSURE TO OUR WEST APPROACHING
WILL LEAD TO WARMER TEMPERATURES ALOFT. THIS WILL PRESENT A CHANCE
FOR A WINTRY MIX TO START...CHANGING TO RAIN FROM SOUTHEAST TO
NORTHWEST LATER IN THE DAY AS WARMER AIR RIDES INTO THE AREA. MAINLY
RAIN AT NIGHT AHEAD OF THE COLD FRONT AND ANOMALOUSLY WARM AIR
ADVECTING OVER THE AREA. ALONG WITH THIS WILL ALSO BE ADVECTION
FOG...PATCHY IN NATURE DURING THE AREA BUT LIKELY GROWING IN AREA AT
NIGHT...ESPECIALLY IN ANY LULLS IN RAIN ACTIVITY. TEMPERATURES WILL
BE ON A NON-DIURNAL TREND...RISING SLOWLY SUNDAY EVENING.
A PERIOD OF MODERATE RAIN IS FORECAST SUNDAY NIGHT INTO EARLY
MONDAY. THIS RAIN COULD BE POTENTIALLY HEAVY AT TIMES WITH
PRECIPITABLE WATER VALUES OF SLIGHTLY OVER 1 INCH...WHICH IS CLOSE
TO 2 STANDARD DEVIATIONS ABOVE NORMAL FOR THE MONTH OF JANUARY. THE
RAIN WILL THEN TAPER OFF FROM WEST TO EAST DURING THE DAY MONDAY
WITH SHOWER ACTIVITY BEHIND THE FRONT. SHARP COLD AIR ADVECTION ON A
STRENGTHENING NORTHWEST FLOW WILL ALLOW FOR SOME SNOW SHOWERS AS WE
GO THROUGH THE DAY. MAX TEMPERATURES FOR MONDAY WILL LIKELY BY SET
IN THE MORNING WITH LOWERING TEMPERATURES FOR THE REMAINDER OF THE
DAY.
ANOTHER VERY COLD AIR MASS BUILDS IN THROUGH MID NEXT WEEK WITH MUCH
BELOW NORMAL TEMPS. HIGH PRESSURE FROM WESTERN CANADA WILL BE
BUILDING TO THE SOUTH AND WEST OF THE REGION. ANOTHER ROUND OF SNOW
SHOWERS WILL BE POSSIBLE ACROSS EASTERN LONG ISLAND AND SOUTHEAST CT
TUESDAY INTO TUESDAY EVENING AS WELL AS NEXT THURSDAY AS PERIODIC
SHORTWAVES ALOFT MOVE ACROSS. TOWARDS THE END OF NEXT WEEK THE DEEP
ANOMALOUS TROUGH PATTERN CHANGES TO MORE OF A QUASI-ZONAL FLOW. ALSO
OF NOTE IS THAT WINDS WILL CONTINUE TO BE GUSTY FROM A WESTERLY
DIRECTION MONDAY THROUGH WEDNESDAY. WIND CHILLS FORECAST COULD REACH
0 TO -10 DEGREES F AT TIMES LATE MONDAY NIGHT THROUGH EARLY
WEDNESDAY.
UNCERTAINTY IS HIGHER WITH THE FORECAST SUNDAY NIGHT THROUGH MONDAY.
VAST DIFFERENCES ARE EVIDENT WITHIN THE ECMWF AND GFS SOLUTIONS.
THESE DIFFERENCES ALSO ARE APPARENT WITHIN THE GFS ENSEMBLE AND MUCH
OF ITS MEMBERS WITH THE LAST TWO RUNS. THE FORECAST CURRENTLY SIDES
MORE WITH THE ECMWF SOLUTION WITH A SLOWER FRONTAL SPEED AND MORE
WESTERN TRACK OF THE LOW SUNDAY INTO MONDAY.
&&
.AVIATION /07Z FRIDAY THROUGH TUESDAY/...
***HIGH IMPACT WINTER STORM THROUGH THIS MORNING***
MODERATE TO LOCALLY HEAVY SNOW AND BLOWING/DRIFTING SNOW...WITH
LIFR/VLIFR CONDS AND MAXIMUM SNOWFALL RATES OF UP TO AN INCH PER
HOUR PER HOUR THROUGH ABOUT 11Z-12Z. ALTHOUGH FALLING SNOW WILL
TAPER OFF FROM 12Z-14Z FROM WEST TO EAST...BLOWING/DRIFTING SNOW
WILL CONTINUE TO IMPACT THE TERMINALS WITH AT LEAST MVFR VSBYS
UNTIL MIDDAY. CONDS IMPROVE TO VFR BY EARLY AFTERNOON. TOTAL SNOW
ACCUMULATIONS WILL RANGE FROM 6-8 INCHES OVER WESTERN TERMINALS
AND FROM 8-10 INCHES OVER EASTERN LONG ISLAND AND SOUTHEAST CT.
NORTH WINDS /350-010 MAG/ 20-25 KT WITH GUSTS 30-35 KT WILL BACK
NW /320-340 MAG/ AFTER 12Z.
NW WINDS 20-25 KT WITH GUSTS 25-35 KT WILL CONTINUE FOR MUCH OF
THE DAY...THEN DIMINISH TO 10 KT OR LESS BY 06Z SAT.
.OUTLOOK FOR 06Z SAT THROUGH TUE...
.FRI NIGHT...VFR.
.SAT-SAT NIGHT...VFR. SW WINDS LESS THAN 10 KT.
.SUNDAY...MVFR CONDS POSSIBLE IN THE AFTERNOON...WITH RAIN/SNOW
ACROSS THE INTERIOR AND RAIN AT THE NYC METRO/LONG ISLAND/COASTAL
CT TERMINALS.
.SUNDAY NIGHT-MON MORNING...IFR CONDS LIKELY IN RAIN. S WINDS
G20-30KT LATE SUNDAY NIGHT/MON MORNING.
.MON AFTERNOON-TUE...CONDS IMPROVING TO VFR. W WINDS G20-30 KT.
&&
.MARINE...
MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. BASED ON DEEPENING DID ADD OCCASIONAL
GUSTS TO 50 KT FOR THE TWO EASTERN COASTAL OCEAN ZONES OVERNIGHT.
WIND AND GUSTS CONTINUE TO INCREASE OVERNIGHT AS THE LOW DEEPENS
AND TRACK SOUTH OF THE WATERS.
VERY ROUGH CONDITIONS ARE ANTICIPATED ON THE WATERS THROUGH
FRIDAY. DEEPENING LOW PRESSURE PASSES TO THE SOUTH AND EAST THIS
TIME FRAME...WITH GALES EXPECTED TONIGHT INTO FRIDAY.
FREEZING SPRAY REMAINS A CONCERN AS WELL.
GALE CONDITIONS END LATER FRIDAY AS HIGH PRESSURE BUILDS. WINDS
DIMINISH QUITE A BIT FRIDAY NIGHT AS THE RIDGE BUILDS.
ROUGH SEAS TONIGHT AND FRIDAY SLOWLY SUBSIDE LATE FRIDAY AND FRIDAY
NIGHT.
SUB SCA SAT MORNING INCREASES TO SCA SOUTHEAST OF LI LATE SAT
THROUGH SUN MORNING. THIS WILL BE MAINLY ACROSS THE EASTERN OCEAN
ZONES. A BRIEF RETURN TO BELOW SCA CONDITIONS WILL BE FOLLOWED BY
ANOTHER ROUND OF SCA SUNDAY NIGHT INTO NEXT WEEK.
&&
.HYDROLOGY...
BETWEEN 1/2 TO 3/4 OF AN INCH OF LIQUID EQUIVALENT IS EXPECTED
THROUGH FRIDAY...ALL FALLING AS SNOW.
ANOTHER WIDESPREAD SIGNIFICANT PRECIP EVENT IS POSSIBLE SUNDAY
THROUGH EARLY MONDAY...MOSTLY IN THE FORM OF RAIN. THE HEAVY RAIN
COULD COMBINE WITH RESIDUAL SNOW COVER TO PRODUCE SOME FLOODING.
GENERAL ESTIMATES OF EVENT TOTAL LIQUID AMOUNTS FROM A MODEL
CONSENSUS ARE AROUND 0.5 TO 1 INCH.
&&
.TIDES/COASTAL FLOODING...
THE HEIGHT OF THE STORM COMES THRU OVERNIGHT...AS A RESULT PEAK
WINDS DO NOT LINE UP WITH THE HIGH TIDE CYCLES IN THE CITY AND ALONG
THE GREAT S BAY. ADVISORY WILL EXPIRE AT MIDNIGHT FOR GREAT SOUTH
BAY - WITH MINOR FLOODING MEASURED AT AREA GAGES THERE.
ACROSS THE SOUND...HIGH TIDE IS AROUND MIDNIGHT...SO THIS LINES UP
BETTER WITH THE GALE FORCE WINDS. SEAS HAVE ALREADY BEEN REPORTED AT
4 FT ON THE SOUND...SO EXPECT WAVES COULD REACH AS HIGH AS 3-6 FT ON
THE N FACING SOUND COASTS. AS A RESULT...THIS SHOULD COMBINE WITH
THE SURGE TO PRODUCE MODERATE FLOODING. A WARNING HAS THEREFORE
BEEN ISSUED FROM THE BRONX AROUND TO CNTRL SUFFOLK. DUE TO
OFFSHORE COMPONENT WINDS...EXPECTING THE IMPACTS TO BE LESSER FROM
WESTCHESTER TO CT...SO AN ADVY ISSUED FOR THOSE SPOTS. AN INCREASE
OF A HALF FT IN SURGE ABV THE HIGHEST GUIDANCE WILL BE REQUIRED
FOR THESE AREAS TO REACH MODERATE.
AN ADVY HAS ALSO BEEN POSTED FOR SERN LI. THIS IS PRIMARILY FOR THE
N FACING PORTIONS OF THE S FORK AND SUSCEPTIBLE AREAS ALONG THE
ATLANTIC WHERE WAVE ACTION WILL SUPPLEMENT THE SURGE.
THERE IS CONSIDERABLE SPREAD WITH THE GUIDANCE FOR THE FRIDAY
MRNG/AFTN HIGH TIDE CYCLE...PARTICULARLY ACROSS THE WRN SOUND WHERE
THE ETSS IS TRYING TO HOLD ONTO A SIGNIFICANT AMOUNT OF WATER.
BECAUSE THIS SOLN IS AN OUTLIER...MINOR OR BLW IS THE MOST LIKELY
OUTCOME FOR ALL AREAS ATTM.
MINOR BEACH EROSION CAN BE EXPECTED ALONG PORTIONS OF THE SOUND AND
WRN OCEAN...WITH MODERATE EROSION ALONG THE CNTRL AND ERN
OCEANFRONT.
&&
.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...WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
CTZ005>012.
COASTAL FLOOD ADVISORY UNTIL 2 AM EST EARLY THIS MORNING FOR
CTZ009-010.
NY...BLIZZARD WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NYZ078>081-
177-179.
WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ067>075-176-178.
COASTAL FLOOD ADVISORY UNTIL 2 AM EST EARLY THIS MORNING FOR
NYZ071.
COASTAL FLOOD WARNING UNTIL 2 AM EST EARLY THIS MORNING FOR
NYZ073-078-176-177.
NJ...WINTER STORM WARNING UNTIL 1 PM EST THIS AFTERNOON FOR NJZ002-
004-006-103>108.
MARINE...GALE WARNING UNTIL 6 PM EST THIS EVENING FOR ANZ330-335-338-
340-345-350-353-355.
&&
$$
SYNOPSIS...JM/PW
NEAR TERM...MALOIT/MET/PW
SHORT TERM...PW
LONG TERM...JM
AVIATION...GOODMAN/MPS
MARINE...JC/JM/MET/PW
HYDROLOGY...JM/PW
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
1158 PM EST THU JAN 2 2014
.SYNOPSIS...
DEEPENING LOW PRESSURE PASSES TO THE SOUTH TONIGHT...THEN DEPARTS
TO THE EAST FRIDAY. HIGH PRESSURE BUILDS FRIDAY NIGHT. HIGH
PRESSURE WILL MOVE EAST AND OFFSHORE THIS WEEKEND WITH ANOTHER LOW
DEVELOPING ALONG THE APPALACHIANS SUNDAY. THIS WILL DEEPEN TO THE
WEST OF THE REGION WITH A COLD FRONT MOVING ACROSS MONDAY. ANOTHER
ARCTIC AIRMASS BUILDS IN BEHIND IT AS WESTERN CANADA HIGH PRESSURE
BUILDS TO THE SOUTH AND WEST OF THE REGION THROUGH MID NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
TEMPERATURES ARE FALLING OFF MORE RAPIDLY THAN FORECAST - HAVE
ADJUSTED DOWNWARD BASED ON HRRR 2-M TEMPERATURES WHICH SEEM TO AVE
BEST HANDLE ON CURRENT TRENDS. AS A RESULT - COULD END UP WITH
SLIGHTLY HIGHER SNOW TO LIQUID RATIOS - SO ADDED LOCALLY HIGHER
AMOUNTS POSSIBLE TO THE WSW TEXT.
SPS OUT FOR SNOW BAND IMPACTING S NASSAU AND SUFFOLK - WITH RATES
1-2 INCH/HR. WILL MONITOR AND UPDATE AMOUNTS IF NEEDED.
AT 4Z A 996 HPA LOW WAS LOCATED ABOUT 210 MILES S OF KMTP LIFTING
NNE PER LATEST PRESSURE FALLS...WITH RAPID DEEPENING EXPECTED TO
CONTINUE. WITH THE STEEP PRESSURE FALLS DUE EXPECT WINDS TO
CONTINUE TO INCREASE OVER THE AREA. DEPENDING ON HOW WINDS AND
VISIBILITIES TREND - THERE IS A CHANCE FOR A SHORT FUSED EXPANSION
OF THE BLIZZARD WARNING - WITH MOST LIKELY CANDIDATES BEING SE CT
AND POSSIBLY NYC. EXPECT HEAVIEST SNOWFALL ACROSS THE AREA
GENERALLY THROUGH 9Z THEN A TAPERING OFF FROM W TO E.
MODEL OUTPUT FOR TONIGHT REMAINS FAIRLY CLOSE...WITH GFS AND
ECMWF A BIT WETTER THAN NAM/WRF.
SREF ENSEMBLE WOULD SUGGEST A QPF BLEND IS PERHAPS THE WAY TO GO AT
THIS TIME. QPF OF AROUND 1/2 INCH TO 3/4 OF AN INCH IS EXPECTED.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/...
VERY COLD AIR THIS TIME FRAME.
MORNING SNOW ENDS FROM WEST TO EAST AS THE UPPER TROUGH PIVOTS
ACROSS THE NORTHEAST AND THE DEEPENING COASTAL LOW DEPARTS. SNOW
ACCUMULATIONS 5 TO 10 INCHES...WITH PERHAPS SOME HIGHER AMOUNTS OVER LI
PER LOW TRACK/HEAVIEST SNOW CLIMATOLOGY.
WINDY CONDITIONS WILL RESULT IN BLOWING SNOW THROUGH THE MORNING AND
INTO THE AFTERNOON.
SKIES CLEAR DURING THE AFTERNOON...AGAIN FROM WEST TO EAST.
TEMPS RISE LITTLE DURING THE DAY...AND IN FACT REMAIN NEARLY STEADY
BEFORE DROPPING LATER IN THE DAY. MAX TEMPS IN THE TEENS EXPECTED.
FOR FRIDAY NIGHT...A RIDGE OF HIGH PRESSURE BUILDS IN. AS WINDS
LIGHTEN AND SKIES REMAIN CLEAR...TEMPS WILL PLUMMET INTO THE SINGLE
DIGITS AND BELOW ZERO ACROSS THE REGION. WENT CLOSER TO COLDER MAV
DATA...WHICH MAY NOT EVEN BE COLD ENOUGH AS MOS TRENDS TOWARD CLIMATOLOGY
AND DOES NOT USUALLY HANDLE IMPACTS OF A FRESH SNOWPACK WELL.
HOWEVER...SOME WAA MID AND HIGH CLOUDS APPROACH LATE AT
NIGHT...WHICH COULD HAVE A MINOR IMPACT ON TEMPS.
&&
.LONG TERM /SATURDAY THROUGH THURSDAY/...
THE JET STREAM LIFTS GRADUALLY NORTH OF THE REGION THIS WEEKEND BUT
WILL DIVE BACK SOUTH OF THE REGION FOR NEXT WEEK. A RIDGING TREND IN
THE MID LEVELS MUCH OF THE WEEKEND WITH DECREASING HEIGHTS SUNDAY
AFTERNOON INTO NEXT WEEK WITH A MUCH COLDER AIRMASS APPROACHING.
AT THE SURFACE...THE ARCTIC HIGH PRESSURE WILL BE CENTERED ACROSS
THE REGION SATURDAY MORNING AND WILL PUSH OFFSHORE THROUGH THE DAY.
THIS WILL CONTINUE TO MOVE EAST THROUGH THE WEEKEND...WITH A
CONTINUANCE OF RETURN SOUTHERLY FLOW. THE RESULT WILL BE A
MODERATION OF THE AIRMASS...ALTHOUGH WITH LIMITED MIXING HEIGHTS
SATURDAY...ONLY TO BETWEEN 1000 AND 950 MB. HIGHS ARE FORECAST TO
STILL BE ABOUT 10 DEGREES BELOW NORMAL.
THE MODERATION WILL BE MORE REMARKABLE AT NIGHT...ESPECIALLY ALONG
THE COAST WITH THE INCREASINGLY ONSHORE FLOW AS HIGH PRESSURE
CONTINUE TO MOVES OFFSHORE. LOWS SATURDAY NIGHT ARE FORECAST TO BE
CLOSER TO NORMAL BUT STILL LIKELY BELOW NORMAL ACROSS THE INTERIOR
WITH LIGHTER WINDS THERE.
A REMARKABLE REBOUND IN TEMPERATURES FOR SUNDAY WITH THE CONTINUED
RETURN SOUTHERLY FLOW. HOWEVER...TEMPERATURES FREEZING OR BELOW IN
THE MORNING WITH NEXT WAVE OF LOW PRESSURE TO OUR WEST APPROACHING
WILL LEAD TO WARMER TEMPERATURES ALOFT. THIS WILL PRESENT A CHANCE
FOR A WINTRY MIX TO START...CHANGING TO RAIN FROM SOUTHEAST TO
NORTHWEST LATER IN THE DAY AS WARMER AIR RIDES INTO THE AREA. MAINLY
RAIN AT NIGHT AHEAD OF THE COLD FRONT AND ANOMALOUSLY WARM AIR
ADVECTING OVER THE AREA. ALONG WITH THIS WILL ALSO BE ADVECTION
FOG...PATCHY IN NATURE DURING THE AREA BUT LIKELY GROWING IN AREA AT
NIGHT...ESPECIALLY IN ANY LULLS IN RAIN ACTIVITY. TEMPERATURES WILL
BE ON A NON-DIURNAL TREND...RISING SLOWLY SUNDAY EVENING.
A PERIOD OF MODERATE RAIN IS FORECAST SUNDAY NIGHT INTO EARLY
MONDAY. THIS RAIN COULD BE POTENTIALLY HEAVY AT TIMES WITH
PRECIPITABLE WATER VALUES OF SLIGHTLY OVER 1 INCH...WHICH IS CLOSE
TO 2 STANDARD DEVIATIONS ABOVE NORMAL FOR THE MONTH OF JANUARY. THE
RAIN WILL THEN TAPER OFF FROM WEST TO EAST DURING THE DAY MONDAY
WITH SHOWER ACTIVITY BEHIND THE FRONT. SHARP COLD AIR ADVECTION ON A
STRENGTHENING NORTHWEST FLOW WILL ALLOW FOR SOME SNOW SHOWERS AS WE
GO THROUGH THE DAY. MAX TEMPERATURES FOR MONDAY WILL LIKELY BY SET
IN THE MORNING WITH LOWERING TEMPERATURES FOR THE REMAINDER OF THE
DAY.
ANOTHER VERY COLD AIRMASS BUILDS IN THROUGH MID NEXT WEEK WITH MUCH
BELOW NORMAL TEMPS. HIGH PRESSURE FROM WESTERN CANADA WILL BE
BUILDING TO THE SOUTH AND WEST OF THE REGION. ANOTHER ROUND OF SNOW
SHOWERS WILL BE POSSIBLE ACROSS EASTERN LONG ISLAND AND SOUTHEAST CT
TUESDAY INTO TUESDAY EVENING AS WELL AS NEXT THURSDAY AS PERIODIC
SHORTWAVES ALOFT MOVE ACROSS. TOWARDS THE END OF NEXT WEEK THE DEEP
ANOMALOUS TROUGH PATTERN CHANGES TO MORE OF A QUASI-ZONAL FLOW. ALSO
OF NOTE IS THAT WINDS WILL CONTINUE TO BE GUSTY FROM A WESTERLY
DIRECTION MONDAY THROUGH WEDNESDAY. WIND CHILLS FORECAST COULD REACH
0 TO -10 DEGREES F AT TIMES LATE MONDAY NIGHT THROUGH EARLY
WEDNESDAY.
UNCERTAINTY IS HIGHER WITH THE FORECAST SUNDAY NIGHT THROUGH MONDAY.
VAST DIFFERENCES ARE EVIDENT WITHIN THE ECMWF AND GFS SOLUTIONS.
THESE DIFFERENCES ALSO ARE APPARENT WITHIN THE GFS ENSEMBLE AND MUCH
OF ITS MEMBERS WITH THE LAST TWO RUNS. THE FORECAST CURRENTLY SIDES
MORE WITH THE ECMWF SOLUTION WITH A SLOWER FRONTAL SPEED AND MORE
WESTERN TRACK OF THE LOW SUNDAY INTO MONDAY.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
***HIGH IMPACT WINTER STORM TONIGHT INTO FRIDAY***
SNOW OVERSPREADS THE TERMINALS WITH IFR/LIFR CONDITIONS. SNOW BECOMES
MODERATE TO HEAVY WITH LIFR/VLIFR CONDITIONS AND SNOWFALL RATES OF 1 TO 2
INCHES PER HOUR FROM AROUND 05Z-12Z. ALTHOUGH FALLING SNOW WILL
TAPER OFF FROM 12Z-14Z FROM WEST TO EAST...BLOWING SNOW WILL
CONTINUE TO IMPACT THE TERMINALS WITH IFR VSBYS UNTIL THE MIDDLE OF
THE DAY. CONDITIONS IMPROVE TO VFR BY EARLY AFTERNOON. TOTAL SNOW
ACCUMULATIONS WILL RANGE FROM 6-8 INCHES OVER WESTERN TERMINALS AND
FROM 8-10 INCHES OVER EASTERN LONG ISLAND AND SOUTHEAST CT.
N-NE WINDS (020-040 MAG) AROUND 20 KT WITH GUSTS 25-30 KT WILL BACK
TO THE NORTH (350-010 MAG) AND INCREASE TO 20-30 KT WITH 30-40 KT
GUSTS BY 05Z. WINDS BACK FURTHER TO THE NW (330-350 MAG) AFTER
12Z FRIDAY.
NW WINDS 20-25G25-35KT WILL CONTINUE FOR MUCH OF FRIDAY BEFORE
DIMINISHING BY EARLY EVENING.
.OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY...
.FRIDAY NIGHT...VFR. WINDS DIMINISH TO 10 KT OR LESS BY 06Z.
.SATURDAY-SATURDAY NIGHT...VFR. SW WINDS LESS THAN 10 KT.
.SUNDAY...MVFR POSSIBLE IN THE AFTERNOON. RAIN POSSIBLE ACROSS
KNYC/COASTAL CT/LONG ISLAND/NE NJ TERMINALS AND RAIN/SNOW POSSIBLE
ACROSS THE INTERIOR.
.SUNDAY NIGHT-MONDAY MORNING...IFR CONDITIONS LIKELY IN RAIN. SOUTH
WINDS GUSTING TO 20-30 KT LATE SUNDAY NIGHT/MONDAY MORNING.
.MONDAY AFTERNOON...CONDS IMPROVING TO VFR. WINDS BACK TO THE
WEST. 20-30 KT GUSTS POSSIBLE.
.TUESDAY...VFR. WEST WINDS 15-20 KT WITH 20-30 KT GUSTS.
&&
.MARINE...
MINOR CHANGES THIS UPDATE TO REFLECT THE LATEST TRENDS IN
OBSERVATIONS AND GUIDANCE. BASED ON DEEPENING DID ADD OCCASIONAL
GUSTS TO 50 KT FOR THE TWO EASTERN COASTAL OCEAN ZONES OVERNIGHT.
WIND AND GUSTS CONTINUE TO INCREASE OVERNIGHT AS THE LOW DEEPENS
AND TRACK SOUTH OF THE WATERS.
VERY ROUGH CONDITIONS ARE ANTICIPATED ON THE WATERS THROUGH
FRIDAY. DEEPENING LOW PRESSURE PASSES TO THE SOUTH AND EAST THIS
TIME FRAME...WITH GALES EXPECTED TONIGHT INTO FRIDAY.
FREEZING SPRAY REMAINS A CONCERN AS WELL.
GALE CONDITIONS END LATER FRIDAY AS HIGH PRESSURE BUILDS. WINDS
DIMINISH QUITE A BIT FRIDAY NIGHT AS THE RIDGE BUILDS.
ROUGH SEAS TONIGHT AND FRIDAY SLOWLY SUBSIDE LATE FRIDAY AND FRIDAY
NIGHT.
SUB SCA SAT MORNING INCREASES TO SCA SOUTHEAST OF LI LATE SAT
THROUGH SUN MORNING. THIS WILL BE MAINLY ACROSS THE EASTERN OCEAN
ZONES. A BRIEF RETURN TO BELOW SCA CONDITIONS WILL BE FOLLOWED BY
ANOTHER ROUND OF SCA SUNDAY NIGHT INTO NEXT WEEK.
&&
.HYDROLOGY...
BETWEEN 1/2 TO 3/4 OF AN INCH OF LIQUID EQUIVALENT IS EXPECTED
THROUGH FRIDAY...ALL FALLING AS SNOW.
ANOTHER WIDESPREAD SIGNIFICANT PRECIP EVENT IS POSSIBLE SUNDAY
THROUGH EARLY MONDAY...MOSTLY IN THE FORM OF RAIN. THE HEAVY RAIN
COULD COMBINE WITH RESIDUAL SNOW COVER TO PRODUCE SOME FLOODING.
GENERAL ESTIMATES OF EVENT TOTAL LIQUID AMOUNTS FROM A MODEL
CONSENSUS ARE AROUND 0.5 TO 1 INCH.
&&
.TIDES/COASTAL FLOODING...
THE HEIGHT OF THE STORM COMES THRU OVERNIGHT...AS A RESULT PEAK
WINDS DO NOT LINE UP WITH THE HIGH TIDE CYCLES IN THE CITY AND ALONG
THE GREAT S BAY. ADVISORY WILL EXPIRE AT MIDNIGHT FOR GREAT SOUTH
BAY - WITH MINOR FLOODING MEASURED AT AREA GAUGES THERE.
ACROSS THE SOUND...HIGH TIDE IS AROUND MIDNIGHT...SO THIS LINES UP
BETTER WITH THE GALE FORCE WINDS. SEAS HAVE ALREADY BEEN REPORTED AT
4 FT ON THE SOUND...SO EXPECT WAVES COULD REACH AS HIGH AS 3-6 FT ON
THE N FACING SOUND COASTS. AS A RESULT...THIS SHOULD COMBINE WITH
THE SURGE TO PRODUCE MODERATE FLOODING. A WRNG HAS THEREFORE BEEN
ISSUED FROM THE BRONX AROUND TO CNTRL SUFFOLK. DUE TO OFFSHORE
COMPONENT WINDS...EXPECTING THE IMPACTS TO BE LESSER FROM
WESTCHESTER TO CT...SO AN ADVY ISSUED FOR THOSE SPOTS. AN INCREASE
OF A HALF FT IN SURGE ABV THE HIGHEST GUIDANCE WILL BE REQUIRED FOR
THESE AREAS TO REACH MODERATE.
AN ADVY HAS ALSO BEEN POSTED FOR SERN LI. THIS IS PRIMARILY FOR THE
N FACING PORTIONS OF THE S FORK AND SUSCEPTIBLE AREAS ALONG THE
ATLANTIC WHERE WAVE ACTION WILL SUPPLEMENT THE SURGE.
THERE IS CONSIDERABLE SPREAD WITH THE GUIDANCE FOR THE FRIDAY
MRNG/AFTN HIGH TIDE CYCLE...PARTICULARLY ACROSS THE WRN SOUND WHERE
THE ETSS IS TRYING TO HOLD ONTO A SIGNIFICANT AMOUNT OF WATER.
BECAUSE THIS SOLN IS AN OUTLIER...MINOR OR BLW IS THE MOST LIKELY
OUTCOME FOR ALL AREAS ATTM.
MINOR BEACH EROSION CAN BE EXPECTED ALONG PORTIONS OF THE SOUND AND
WRN OCEAN...WITH MODERATE EROSION ALONG THE CNTRL AND ERN
OCEANFRONT.
&&
.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...WINTER STORM WARNING UNTIL 1 PM EST FRIDAY FOR CTZ005>012.
COASTAL FLOOD ADVISORY UNTIL 2 AM EST FRIDAY FOR CTZ009-010.
NY...BLIZZARD WARNING UNTIL 1 PM EST FRIDAY FOR NYZ078>081-177-179.
WINTER STORM WARNING UNTIL 1 PM EST FRIDAY FOR NYZ067>075-176-
178.
COASTAL FLOOD ADVISORY UNTIL 2 AM EST FRIDAY FOR NYZ071.
COASTAL FLOOD ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ080-
081-179.
COASTAL FLOOD WARNING UNTIL 2 AM EST FRIDAY FOR NYZ073-078-176-
177.
NJ...WINTER STORM WARNING UNTIL 1 PM EST FRIDAY FOR NJZ002-004-006-
103>108.
MARINE...GALE WARNING UNTIL 6 PM EST FRIDAY FOR ANZ330-335-338-340-345-
350-353-355.
&&
$$
SYNOPSIS...JM/PW
NEAR TERM...MALOIT/MET/PW
SHORT TERM...PW
LONG TERM...JM
AVIATION...MPS
MARINE...JC/JM/MET/PW
HYDROLOGY...JM/PW
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MELBOURNE FL
1020 AM EST FRI JAN 3 2014
.DISCUSSION...
...HAZARDOUS MARINE CONDITIONS THROUGH TONIGHT...
...WINDY AND MUCH COLDER TODAY...
CURRENT...VISIBLE/WATER VAPOR SATELLITE IMAGERY SHOWS ABUNDANT MID
AND HIGH LEVEL CLOUD COVER CONTINUING ACROSS ECFL THIS MORNING.
BOTH RUC ANLYS FIELDS AND THE MORNING RAOBS FROM JAX/TBW/XMR SHOW
NEARLY SATURATED AND DIVGT CONDITIONS IN THE H50-H20 LAYER ACTING
TO PRODUCE THOSE CLOUDS. ALSO...AN EXPANSIVE AREA OF CAA-INDUCED
CLOSED-CELL MARINE STRATOCU IS ALREADY IMPINGING UPON COASTAL
VOLUSIA AND BREVARD COUNTIES. CCAFS 915MHZ WIND PROFILER DATA IS
SUPPORTIVE OF THIS....SHOWING 0-2KM WINDS ALREADY STARTING TO
VEER TO 360-010.
STRONG CAA HAS BEEN WINNING OUT OVER WEAK EARLY JAN/EARLY MORNING
DIURNAL HEATING AS TEMPS AREAWIDE HAVE CONTINUED TO EITHER SLOWLY
DROP OR HOLD STEADY IN THE 2-3HRS SINCE SUNRISE. THIS HAS ALSO
KEPT WCI VALUES IN LAKE/VOLUSIA COS IN THE L30S...SO HAVING THE
NPW/WCA ISSUED UNTIL 10AM TODAY WAS AN EXCELLENT CALL BY THE THU
AFTERNOON SHIFT.
REST OF TODAY...BLUSTERY AND CHILLY FOR MOST OF THE AREA. NORTHERLY
WINDS IN THE 15-25MPH RANGE WILL BE VERY SLOW TO RELAX AS THEY TRY
AND VEER TO NNE THROUGH LATE AFTERNOON. TEMPS WILL STRUGGLE TO RISE
IN THE CAA PATTERN WITH MAXES RANGING FROM ~50F AROUND LAKE GEORGE
AND THE OCALA FOREST...TO THE LOW 60S ACROSS MARTIN COUNTY...WHICH
MEANS 50S FOR MOST OF THE CWA. MADE SOME ADJUSTMENTS TO THE TEMP...
WIND AND SKY COVER GRIDS TO ACCOUNT FOR CURRENT CONDITIONS. THIS
WILL CHANGE ALL THE COASTAL COUNTIES TO "MOSTLY CLOUDY" OR BECOMING
SO BY THIS AFTERNOON DUE TO THE AFOREMENTIONED MARINE CLOUDS.
&&
.AVIATION...VFR CIGS AOB BKN-OVC150 WILL GRADUALLY LIFT ENE AWAY
FROM THE AREA AS H25 JET STREAK/ATTENDANT MOISTURE DOES LIKEWISE.
MVFR CIGS BKN-OVC025-030 CURRENTLY INVADING OMN-DAB-EVB-TIX WILL
CONTINUE TO SPREAD SWD ALONG THE MLB-VRB-FPR CORRIDOR AS 0-1KM
WINDS CONTINUE TO VEER TODAY/TONIGHT.
&&
.MARINE...GIVEN CURRENT WIND/SEA CONDITIONS AT 41009/41012...AS
WELL AS WINDS AT SPGF1...THOUGHT IT WAS PRUDENT TO EXTEND THE GALE
WARNING (FOR FREQUENT GUSTS TO GALE FORCE) INTO THIS AFTERNOON.
OTHERWISE...CURRENT FORECAST FOR WINDS/SEAS CONTINUE ON TRACK.
&&
UPDATE/AVIATION...CRISTALDI
LONG TERM/IMPACT WX...WEITLICH
&&
.PREV DISCUSSION... /ISSUED 400 AM EST FRI JAN 3 2014/
TONIGHT...RAPID AIRMASS MODIFICATION WILL OCCUR AS WINDS VEER
ONSHORE...PUSHING WARM OCEAN AIR AND A BLANKET OF MARINE STRATOCU
BACK ACRS CENTRAL FL. SO RAPID THE MODIFICATION WILL BE THAT SOME
"MIN" TEMPS ALONG THE SPACE AND TREASURE COASTS TONIGHT ACTUALLY MAY
BE WARMER THAN THIS AFTN "MAX" TEMPS...CERTAINLY A DIFFERENCE OF
ARND 5F BTWN THE TWO WILL BE COMMON. INTERIOR TEMPS WILL REMAIN A
FEW DEGS BLO AVG ALONG AND N OF THE I-4 CORRIDOR (L/M40S)...WINDS
EXPECTED TO DIMINISH BLO 10MPH AFT SUNSET...LCL CRITERIA FOR A WIND
CHILL ADVISORY NOT EXPECTED.
PRECIP NOT COMPLETELY OUT OF THE QUESTION....BUT WITH SUCH A STRONG
CAP IN PLACE...VERTICAL MOTION WILL BE WELL BLO 10KFT. ANY IMPACT
FROM SUCH LOW TOPPED SHRAS WOULD BE MINIMAL...WILL KEEP THE FCST DRY
THRU DAYBREAK.
SATURDAY...SFC HIGH PRESSURE NEAR THE MID ATLC WILL PUSH OFFSHORE
ALLOWING FOR MARINE CLOUDINESS TO PUSH ONSHORE ACROSS E CENTRAL FL.
SOME ISOLATED LIGHT SHOWERS MAY MOVE ONSHORE ALONG THE IMMEDIATE
COAST AND A MID LVL S/W TROUGH ACROSS THE SE GULF OF MEXICO WILL
SPREAD CLOUDINESS ACROSS SRN AREAS IN THE AFTERNOON WHERE SOME LATE
DAY SHOWERS MAY ALSO BREAK OUT ACROSS OKEECHOBEE COUNTY. THE ONSHORE
FLOW OFF THE RELATIVELY WARM ATLC WILL ALLOW FOR A 15-20 WARM UP IN
TEMPS FROM VERY COOL FRIDAY READINGS. WILL SEE HIGHS AROUND 70 NORTH
COASTAL AREAS TO MID 70S SRN SECTIONS.
SAT NIGHT...MID LVL DISTURBANCES WILL TRACK NE ACROSS SRN FL WITH
VEERING LOW LVL FLOW. NAM KEEPS MOST OF THE HEAVIER PRECIP OFF THE
TREASURE COAST WHILE 18Z/00Z GFS ALLOWS SHOWERS TO MOVE ONSHORE WITH
HEALTHIER QPF FROM BREVARD SOUTH TO MARTIN COUNTY. WILL LEAN TWD THE
GFS AND SHOW HIGH CHC POPS IN THESE AREAS WITH LOWER CHC POPS TO
SLGT CHC POPS ACROSS NRN INTERIOR SECTIONS. LOWS IN THE MID-UPR 50S
NORTH AND MID 60S S CSTL.
SUNDAY...LOW LVL SW FLOW AHEAD OF THE NEXT FRONT AND ADEQUATE
MOISTURE LEVELS WILL TRIGGER SCATTERED AFTERNOON SHOWERS. WILL KEEP
RAIN CHANCES CLOSE TO MOS AROUND 30 PCT FOR LAKE COUNTY TO 50 PCT
ALONG THE TREASURE COAST. HIGHS WILL WARM INTO THE UPPER 70S TO
LOWER 80S.
MONDAY....A REINFORCING TROUGH DROPS INTO THE UPPER MIDWEST ON
MONDAY AND ALLOWS ANOTHER COLD FRONT TO MOVE DOWN THE FL PENINSULA.
THE FAST MOVING FRONT WILL NOT HAVE SUBSTANTIAL PREFRONTAL MOISTURE
TO WORK WITH...EXCEPT ACROSS S FL. EXPECT ISOLATED SHOWERS ALONG THE
FRONT ACROSS NRN AREAS AND SLIGHTLY HIGHER COVERAGE ACROSS SRN
SECTIONS. HIGHS WILL RANGE FROM THE 60S NORTH TO LOWER 70S SRN
AREAS. BREEZY NW WINDS WILL DEVELOP AFTER THE FRONTAL PASSAGE.
MONDAY NIGHT-TUESDAY NIGHT...SFC HIGH PRESSURE WILL BUILD FROM THE
THE LWR MS VALLEY INTO THE SE STATES EARLY NEXT WEEK WITH THE FIRST
PROLONGED STRETCH OF COLD NORTHERLY LOW LVL FLOW FOR AROUND 36 HOURS
THIS WINTER SEASON. THIS WILL PRODUCE TWO COLD NIGHTS EARLY NEXT
WEEK WITH LOW INTO THE 30S ACROSS MUCH OF NORTHERN AND INTERIOR
SECTIONS OF E CENTRAL FL AND 40S ACROSS SRN COASTAL AREAS. HIGHS
TUESDAY WILL ONLY BE IN THE 50S...EXCEPT INTO THE LOWER 60S ACROSS
THE SRN TREASURE COAST.
WED-FRI...HIGH PRESSURE WILL MOVE TOWARD THE MID ATLC ON WEDNESDAY
AND OFFSHORE THROUGH LATE WEEK ALLOW LOW LVL WINDS TO VEER TO
ONSHORE OFF THE RELATIVELY MILD ATLANTIC WATERS. A GRADUAL WARMING
TREND IS EXPECTED BY THU INTO FRI WITH HIGHS RETURNING TO MID TO
UPPER 70S MOST AREAS. EXPECT MAINLY DRY WEATHER...EXCEPT FOR A
SLIGHT SHOWER CHANCE ON THURSDAY.
&&
.AVIATION...
THRU 03/12Z...W/NW SFC WND G21-25KT...AREAS CIGS BTWN FL020-030 LCL
CIGS BTWN FL010-020. BTWN 03/12Z-03/22Z...N/NW SFC WND G22-26KTS...
VFR ALL SITES. AFT 03/22Z...VFR CIGS BTWN FL030-040 COASTAL SITES...
BTWN FL040-050 INTERIOR SITES.
&&
.MARINE...
TODAY-TONIGHT...DANGEROUS BOATING CONDITIONS AS A POST FRONTAL HI
PRES RIDGE EXTENDING FROM THE BAY OF CAMPECHE TO THE GREAT LAKES
GENERATES A STRONG N/NW BREEZE WITH NEAR GALE STRENGTH OVER THE
OFFSHORE WATERS N OF SEBASTIAN INLET. OFFSHORE DATA BUOYS ALREADY
MEASURING 25-30KT NW WINDS WITH FRQT GUSTS AOA GALE FORCE. SEAS HAVE
YET TO RESPOND TO THE INCREASED WINDS BUT WILL BUILD STEADILY TO
6-8FT NEARSHORE AND UP TO 12FT OFFSHORE THRU THE DAY AS WINDS VEER
TO THE N/NE AND COUNTER THE SRLY GULF STREAM CURRENT. WINDS WILL
DIMINISH BLO SCA CRITERIA AFT SUNSET AS THE POST FRONTAL RIDGE
PUSHES INTO THE W ATLC AND BEGINS TO WEAKEN...THOUGH OVERALL
CONDITION WILL REMAIN QUITE POOR.
CURRENT GALE/SCA CONFIGURATION LOOKS GOOD...BUT WILL EXTEND THE
EXPIRATION TIME FOR THE SCA TO 09Z AREAWIDE...AND TO 15Z FOR THE
OFFSHORE LEG.
EAST WINDS AROUND 15 KNOTS ON SATURDAY ARE EXPECTED WITH SEAS SLOWLY
DIMINISHING TO 4-6 FT. SE/S FLOW AT 10-15 KNOTS ON SUNDAY WITH
HIGHER PRECIP COVERAGE EXPECTED ACROSS THE SRN WATERS. NEXT FRONT
WILL BRING HAZARDOUS BOATING CONDITIONS EARLY NEXT WEEK AS FRONT
MOVES THROUGH THE WATERS DURING THE DAY AND WINDS INCREASE TO 25
KNOTS FROM THE NORTHWEST. EXPECT SEAS TO BUILD TO 10-13 FEET BY
MONDAY NIGHT INTO EARLY TUESDAY AFTERNOON THE OFFSHORE AND GULF
STREAM WATERS.
&&
.FIRE WEATHER...MIN RHS WILL APPROACH 35 PERCENT ACROSS THE INTERIOR
WITH BREEZY N WINDS. ERC VALUES ARE CURRENTLY MISSING BUT WITH SOME
RAIN YESTERDAY WILL HOLD OFF ANY RED FLAG HEADLINES. ONSHORE FLOW
SATURDAY WILL MITIGATE ANY LOW RH CONCERNS. STRONG AND GUSTY NW
WINDS NEXT MONDAY AND LOW RH MAY REQUIRE FIRE WEATHER HEADLINES
EARLY NEXT WEEK.
&&
.CLIMATE...TEMPERATURES SHORTLY AFTER MIDNIGHT IN THE UPPER 60S AT
ORLANDO/MELBOURNE AND VERO BEACH AND IN THE UPPER 50S AT DAYTONA
BEACH WILL BE THE CALENDAR DAY HIGH TEMPERATURES AS A COLD FRONT
BRINGS MUCH COLDER TEMPERATURES TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DAB 50 47 70 60 / 10 10 20 20
MCO 56 46 73 59 / 0 10 10 30
MLB 56 53 73 64 / 10 10 20 50
VRB 59 54 74 63 / 10 10 20 50
LEE 50 40 70 57 / 0 10 10 20
SFB 53 45 72 59 / 0 10 10 20
ORL 54 46 72 60 / 0 10 10 30
FPR 60 55 74 64 / 10 10 20 50
&&
.MLB WATCHES/WARNINGS/ADVISORIES...
FL...LAKE WIND ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR COASTAL
VOLUSIA-INDIAN RIVER-INLAND VOLUSIA-MARTIN-NORTHERN BREVARD-
NORTHERN LAKE-OKEECHOBEE-ORANGE-OSCEOLA-SEMINOLE-SOUTHERN
BREVARD-SOUTHERN LAKE-ST. LUCIE.
AM...SMALL CRAFT ADVISORY UNTIL 4 AM SATURDAY FROM FLAGLER BEACH TO
JUPITER INLET OUT 20 NM.
GALE WARNING UNTIL 4 PM THIS AFTERNOON FROM FLAGLER BEACH TO
JUPITER INLET 20 TO 60 NM OFFSHORE.
SMALL CRAFT ADVISORY FROM 4 PM THIS AFTERNOON UNTIL 10 AM
SATURDAY FROM FLAGLER BEACH TO JUPITER INLET 20 TO 60 NM
OFFSHORE.
&&
$$
AREA FORECAST DISCUSSION
NWS JACKSON KY
1207 AM EST FRI JAN 3 2014
.UPDATE...
ISSUED AT 1206 AM EST FRI JAN 3 2014
UPDATED THE FORECAST TO EXTEND THE WINTER WEATHER ADVISORY UNTIL 2 AM
FOR THE BLUEGRASS AND FOR AREAS WEST OF I 75 SINCE IT WAS STILL
SNOWING. THE BLOWING SNOW WILL CONTINUE TO BE A PROBLEM FOR ROAD
CREWS TONIGHT BECAUSE THE SNOW WILL CONTINUE TO BLOW ACROSS THE
ROADWAYS WHEN THEY ARE CLEARED. THE NEXT PROBLEM IS THE WIND CHILL
CAUSED BY THE WIND AND THE COLD AIR THAT CONTINUES TO POUR INTO THE
AREA. THE REST OF THE FORECAST IS ON TRACK.
UPDATE ISSUED AT 1027 PM EST THU JAN 2 2014
SURFACE ANALYSIS AS OF 03Z STILL FEATURES NORTHWEST FLOW IN THE LOWER
LEVELS THOUGH THE OHIO VALLEY WITH A STRONG GRADIENT MAINTAINED AS
WINDS CONTINUE OUT OF THE NORTH NORTHWEST AT 15 TO 25 KNOTS THROUGH
THE AREA. ENOUGH LOW LEVEL MOISTURE CONTINUES TO STREAM SOUTH FROM
THE GREAT LAKES REGION HITTING THE RUGGED TERRAIN OF THE EASTERN
KENTUCKY. THIS...ALONG WITH JUST ENOUGH INSTABILITY OF 10 TO 20
JOULES AT THE SURFACE...HAS ALLOWED FOR CONTINUED BANDS OF SNOW
SHOWERS LASTING THROUGH THE NIGHT HOURS AS SOME ISOLATED AREAS HAVE
SEEN A BIT MORE ACCUMULATION THAN EXPECTED...ESPECIALLY LOCATIONS
WHERE TERRAIN HAS PROFOUND EFFECTS. THIS ALONG WITH THE ALREADY
TREACHEROUS ROADS DUE TO SNOWFALL...BLACK ICE...AND BLUSTERY
CONDITIONS...HAS LEAD TO THE DECISION TO EXTEND THE WINTER WEATHER
ADVISORY UNTIL MIDNIGHT FOR THE NORTHWEST AND SOUTHWEST COUNTIES AND
AS WELL AS THE MIDDLE TIER COUNTIES. ALSO CONTINUING A BIT LONGER
TONIGHT WILL BE THE STRONG NORTHWEST WINDS. THE NAM AND GFS AGREE
KEEPING THE STRONGER GRADIENT THROUGH THE NIGHT SO HAVE BUMPED UP THE
10 TO 15 KNOT WINDS AND GUSTS TO 20 THROUGH AT LEAST 09Z AND BECOMING
LIGHT BY DAWN.
THE WIND COMBINED WITH THE ARCTIC AIR MASS SETTLING IN WILL DROP SOME
WINDS CHILLS BELOW ZERO TONIGHT. HAVE UPDATED THE ZFP AND WSW TO
ADDRESS THESE IMPACT TONIGHT.
UPDATE ISSUED AT 627 PM EST THU JAN 2 2014
SNOW SHOWERS WILL CONTINUE TO PUSH THROUGH EASTERN KENTUCKY THROUGH
THE NIGHT. SOME SMALLER INTENSE BANDS OF SNOW HAVE SET UP AS WELL. AS
OF RIGHT NOW...TEMPS...WINDS AND SNOWFALL AMOUNTS LOOK TO BE ON TRACK.
HAVE FRESHENED UP THE GRIDS WITH THE MOST CURRENT OBSERVATIONS AND
SENT THEM TO NDFD.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 310 PM EST THU JAN 2 2014
19Z SFC ANALYSIS SHOWS THE NOW DEEPER LOW JUST EAST OF KENTUCKY WITH
THE TIGHT ISOBARS CROSSING INTO EAST KENTUCKY. THIS IS RESULTING IN
STIFF NORTHWEST WINDS WITH GUSTS TO 30 MPH BRINGING IN THE MUCH
COLDER AIR. RAIN HAS CHANGED TO SNOW ACROSS WESTERN PARTS OF THE
AREA AND NOW HERE AT JKL. ANOTHER HOUR OR SO IT WILL BE SNOW
EVERYWHERE...IN PLACES THAT STILL ARE PRECIPITATING. THERE IS
CURRENTLY A DISTINCT BACK EDGE TO THIS POST FRONTAL SNOW AREA.
HOWEVER...ANOTHER DECENT BATCH OF SNOW IS DROPPING THROUGH SOUTHERN
INDIANA ON RADAR AND THIS SHOULD MOVE OVER OUR CWA THIS EVENING.
TEMPERATURES CURRENTLY VARY FROM THE LOW 40S NEAR MIDDLESBORO TO
AROUND FREEZING OVER OUR WESTERN COUNTIES. DEWPOINTS ARE PEGGED TO
THE TEMPERATURE IN MOST SPOTS WITH THE GUSTY NORTHWEST WINDS NOW
REPORTED AT MOST OBS SITES IN THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SHARP AND DEEP TROUGH
CURRENTLY SWINGING THROUGH THE AREA. HEIGHTS WILL THEN QUICKLY CLIMB
LATE TONIGHT INTO FRIDAY IN THE WAKE OF THE DEPARTING WAVE. FAST...
MOSTLY ZONAL...FLOW FOLLOWS INTO SATURDAY MORNING WITH ONLY VERY
MINOR BITS OF ENERGY FLOATING BY IN THE AIR STREAM AT MID LEVELS.
WITH NO GREAT DISTINCTION IN THE MODELS HAVE FAVORED A BLEND WITH A
LEAN TOWARD THE HRRR AND NAM12 FOR NEAR TERM SPECIFICS.
SENSIBLE WEATHER WILL FEATURE A BAND OF SNOW MOVING THROUGH EAST
KENTUCKY ASSOCIATED WITH THE RETURN OF AN ARCTIC AIR MASS. SOME
PLACES...PARTICULARLY IN THE SOUTHWEST...WILL SEE A LULL IN THE SNOW
FOR SEVERAL HOURS INTO THE EVENING WITH A POSSIBLE RESURGENCE AROUND
00Z AS THAT SNOW OVER INDIANA MOVES INTO OUR CWA. EVEN IN THOSE
PLACES...HAZARDOUS CONDITIONS WILL EXIST AS WET ROADS A THREAT TO
ICE OVER SINCE THE ARCTIC AIR QUICKLY DROPS TEMPERATURES INTO THE 20S
FROM WEST TO EAST LATE THIS AFTERNOON AND EARLY EVENING.
ACCORDINGLY...WILL MAINTAIN THE CURRENT ADVISORY STRUCTURE AND FOCUS
ON THE REFREEZE FOR WESTERN MOST PLACES THAT WILL NOT GET MUCH OF THE
UPSLOPE. OTHERWISE...UPSLOPE SNOW SHOWERS/ SQUALLS...COLD TEMPS...
AND LOSS OF SOLAR INSOLATION SHOULD HELP THE EASTERN PORTION OF THE
ADVISORIES PICK UP SNOW TOTALS THROUGH THE EVENING. THE SNOWS WILL
TAPER OFF FROM WEST TO EAST LATER TONIGHT...ENDING LAST IN LOCATIONS
NEAR THE VIRGINIA AND WEST VIRGINIA BORDERS TOWARD DAWN. BY THAT TIME
READINGS WILL BE DOWN IN THE TEENS FOR MOST LOCATIONS WITH SOME
SINGLE DIGITS POSSIBLE IN THE FAR NORTHWESTERN PARTS OF THE CWA.
WINDS RUNNING IN THE 5 TO 10 MPH RANGE INTO EARLY FRIDAY MORNING
WILL YIELD WIND CHILLS IN MANY SPOTS DOWN NEAR ZERO. THE QUICK EXIT
OF THE WEATHER MAKER WILL RETURN SUNNY SKIES TO THE AREA ON FRIDAY...
BUT CAA AND THE ARCTIC AIR IN PLACE WILL KEEP TEMPERATURES FROM
GETTING ANY HIGHER THAN THE LOW TO MID 20S. THIS WILL SET THE STAGE
FOR ANOTHER BITTERLY COLD NIGHT WITH READINGS FALLING INTO THE TEENS
AGAIN ALONG WITH NOTICEABLE RIDGE AND VALLEY DIFFERENCES.
AGAIN LEANED ON THE SOLID CONSSHORT OR BC VERSION FOR HOURLY TEMPS...
DEWS...AND WINDS THROUGH 12Z FRIDAY WITH CONSALL AFTER THAT. AS FOR
POPS...WENT HIGHER THAN GUIDANCE TONIGHT DUE TO IT NOT PICKING UP ON
UPSLOPE SNOWS VERY WELL...DRY AFTER THAT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 250 PM EST THU JAN 2 2014
PRETTY GOOD AGREEMENT AMONGST THE MODELS FOR THE EXTENDED PERIOD.
THE ECMWF MODEL IS A BIT MORE ROBUST WITH ITS QPF THAN THE GFS FOR
THE SUNDAY NIGHT THROUGH MONDAY NIGHT WEATHER SYSTEM...AND THE
WEATHER SYSTEM FOR THE END OF THE WEEK. HOWEVER...THE OVERALL LARGE
SCALE WEATHER PATTERN...BOTH ALOFT AND AT THE SURFACE...IS SIMILAR
IN BOTH MODELS. THAT BEING SAID...WENT MORE TOWARD THE ECMWF
SOLUTION THIS TIME AROUND. TOOK DOWN SNOWFALL TOTALS
SLIGHTLY...HOWEVER...AS THE MODELS HAVE MORE WESTERLY...AS OPPOSED
TO NORTHWESTERLY...FLOW FORECAST...WHICH WOULD BE MUCH LESS
FAVORABLE FOR UPSLOPE SNOW SHOWERS. THE DYNAMICS WITH THE SYSTEM TO
BEGIN THE WEEK ARE STILL EXPECTED TO BE QUITE STRONG...WITH A WELL
DEVELOPED AREA OF LOW PRESSURE MOVING OUT OF THE MID MISSISSIPPI
VALLEY THROUGH THE OHIO VALLEY AND THEN INTO THE EASTERN GREAT LAKES
REGION. A 50 TO 60KT LOW LEVEL JET WOULD BRING AMPLE GULF MOISTURE
INTO THE REGION ALOFT TO AID IN ICE CRYSTAL AND THEREFORE SNOWFLAKE
FORMATION SUNDAY NIGHT AND MONDAY. SNOWFALL TOTALS...DUE TO THE GOOD
DYNAMICS...COULD STILL RANGE BETWEEN 2 AND 3 INCHES FOR MOST OF THE
AREA DURING THE INITIAL EVENT. BITTERLY COLD ARCTIC AIR WILL SPILL
INTO THE AREA TO BEING THE WEEK. THE COLDEST NIGHT OF THE UPCOMING
WORK WEEK LOOKS TO BE MONDAY NIGHT...WHEN LOWS COULD CONCEIVABLE
DROP TO ZERO OR BELOW ZERO FOR THE ENTIRE AREA. WITH THE MODEL
SOUNDINGS DEPICTING 850 HPA TEMPERATURES IN THE MINUS 24 TO MINUS 30
RANGE...SUBZERO LOWS MONDAY NIGHT WOULD NOT BE ALL THAT SURPRISING.
THE COLD AIR MASS WILL MODIFY ONLY SLIGHT TUESDAY WITH HIGHS PEAKING
IN THE TEENS FOR MOST OF THE AREA...WITH HIGHS BARELY TOPPING OUT
AROUND 10 DEGREES NORTH OF I-64. LOWS IN THE SINGLE DIGITS ARE
LIKELY TUESDAY NIGHT...AS WINDS GO NEARLY CALM BENEATH PARTLY CLOUDY
SKIES. HIGHS AND LOWS WEDNESDAY THROUGH THURSDAY WILL BE WELL BELOW
AS WELL...AS THE COLD AIR MASS MAINTAINS ITS GRIP ON THE AREA. A
SECOND WEATHER SYSTEM IS THEN PROGGED TO MOVE ACROSS THE TENNESSEE
AND OHIO VALLEY REGIONS TO END THE WEEK...WITH MORE POTENTIAL FOR
ACCUMULATING SNOW WEDNESDAY NIGHT INTO EARLY THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1206 AM EST FRI JAN 3 2014
CEILINGS WILL REMAIN IFR AND MVFR FOR MUCH OF THE REMAINDER OF THE
EVENING ACROSS EASTERN KENTUCKY AS SNOW SHOWERS CONTINUE TO MOVE
THROUGH THE AREA. CEILINGS AND VISIBILITY WILL IMPROVE TONIGHT FROM
SOUTHWEST TO NORTHEAST AS THE SNOW MOVES OFF TO THE NORTHEAST BY 16Z
FRIDAY. WINDS WILL REMAIN QUITE GUSTY UP TO 25 KNOTS FROM THE WEST
AND WEST NORTHWEST AND WILL FINALLY DECREASE TO AROUND 10 KNOTS BY
12Z. VFR CONDITIONS WILL FINALLY RETURN FOR THE AREA BY 18Z.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 2 AM EST FRIDAY FOR KYZ044-050>052-
058>060-079-083-084-104-106-108.
WINTER WEATHER ADVISORY UNTIL 8 AM EST FRIDAY FOR KYZ088-118-120.
WINTER WEATHER ADVISORY UNTIL 6 AM EST FRIDAY FOR KYZ068-069-080-
085>087-107-109>117-119.
&&
$$
UPDATE...JJ
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...JJ
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
830 PM EST SAT JAN 4 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 SUNDAY 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 SUNDAY 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 /01Z SUNDAY THROUGH THURSDAY/...
LARGE AREA OF LOW CLOUDS ASSOCIATED WITH A TROF ALONG THE
ATLANTIC COAST CONTINUES TO MAKE ITS WAY NORTH AND INTO CENTRAL VA.
SFC OBS SHOW CLOUD CIGS AROUND 3-5K FT AT THE NORTHERN EDGE AND
LOWERING TO MVFR 1000-1500 FT FARTHER SOUTH. TIMING OF CLOUDS OVER
TAF SITES WILL BA CHALLENGING BUT EXPECT STRATOCU CIGS OVER
CENTRAL VA EARLY TONIGHT...LOWERING TO MVFR COND AFTER
MIDNIGHT...AND PSBL IFR CONDS AFTER SUNRISE. LIGHT SHOWERS OR
DRIZZLE ASSOCIATED WITH THE COASTAL TROUGH COUPLED WITH A WEAK
DAMMING SCENARIO WILL CREATE POSSIBLE IFR CEILINGS AND VIS SUN
AFTN/EVENING.
EXPECT A CHANCE OF SHOWERS ASSOCIATED WITH AN APPROACHING COLD
FRONT MONDAY. GUSTY NW WINDS RETURN...ESP TO ERN PORTIONS MON NGT
AND TUE MRNG.
&&
.MARINE...
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 1 AM EST SUNDAY FOR ANZ658.
&&
$$
SYNOPSIS...ALB/BMD/JDM
NEAR TERM...ALB/JAB
SHORT TERM...ALB
LONG TERM...BMD
AVIATION...DAP/JEF
MARINE...BMD
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
710 PM EST SAT JAN 4 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 SUNDAY 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 SUNDAY 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 /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDS AT 18Z WITH MOSTLY CLEAR SKIES AND LIGHT SE-S WIND.
SATELLITE IMAGE SHOWING LARGE AREA OF LOW CLOUDS FROM FLORIA TO
THE CAROLINAS ASSOCIATED WITH A TROF ALONG THE ATLANTIC COAST. THE
CLOUDS WILL GRADUALLY MOVE NORTH AS HIGH PRES OFF THE MID ATL
COAST MOVES FARTHER EAST. SFC OBS SHOW CLOUD CIGS AROUND 4000-5000
FT AT THE NORTHERN EDGE AND LOWERING TO MVFR 1000-1500 FT FARTHER
SOUTH. TIMING OF CLOUDS OVER TAF SITES A LITTLE DIFFICULT BUT
EXPECT STRATOCU CIGS OVER CENTRL VA EARLY TONIGHT...LOWERING TO
MVFR COND AFTER MIDNIGHT...AND PSBL IFR CONDS AFTER SUNRISE.
A CHANCE OF SHOWERS IS IN THE FORECAST LATE SUNDAY THROUGH MONDAY.
GUSTY NW WINDS RETURN...ESP TO ERN PORTIONS MON NGT AND TUE MRNG.
&&
.MARINE...
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 1 AM EST SUNDAY FOR ANZ658.
&&
$$
SYNOPSIS...ALB/BMD/JDM
NEAR TERM...ALB/JAB
SHORT TERM...ALB
LONG TERM...BMD
AVIATION...JEF
MARINE...BMD
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1254 PM EST FRI JAN 3 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 328 AM EST FRI JAN 3 2014
THE BIG WEATHER STORY THROUGH THE NEXT FEW DAYS WILL BE THE ARRIVAL
OF AN ARCTIC BLAST SATURDAY NIGHT AND THE CORE OF THE COLDEST AIR
COMING ON MONDAY AND TUESDAY. MEANTIME...WE/LL SEE SOME SUNSHINE
TODAY BEFORE LAKE CLOUDS DEVELOP. HOWEVER THE WIND IS GOING TO PICK
UP AND WHEN COMBINED WITH TEMPS IN THE TEENS WILL PRODUCE WIND
CHILLS IN THE 10 TO 15 BELOW RANGE EARLY TODAY. THE COLDEST AIR WILL
ARRIVE MONDAY AND TUESDAY. TEMPERATURES WILL STRUGGLE TO RISE ABOVE
0. WIND CHILLS 20 TO 30 BELOW SEEM LIKELY MONDAY AND TUESDAY. WARMER
AIR WILL ARRIVE BY THE END OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1104 AM EST FRI JAN 3 2014
DOMINANT LAKE SNOW BAND IS CURRENTLY MOVING ONSHORE NEAR
MUSKEGON...BUT BOTH RADAR AND SURFACE OBSERVATIONS SUGGEST THAT
THE INTENSITY IS WEAK.
REGARDING INCREASING WIND LATER TODAY...LATEST HRRR MODEL
GUIDANCE SUGGESTS THAT EXPOSED LAKESHORE AREAS TO THE NORTH
/I.E... THE SABLE POINTS/ COULD SEE WIND ADVISORY CRITERIA BEING
MET AT THE IMMEDIATE LAKESHORE. GIVEN A WIND DIRECTION GENERALLY
FROM THE SOUTH...DO NOT EXPECT MUCH INLAND EXTENT TO THE STRONGEST
WINDS SO DO NOT PLAN TO ISSUE A WIND ADVISORY.
AFTER DISCUSSION WITH THE DETROIT AND NORTHERN INDIANA OFFICES...
WILL BE ISSUING A WINTER STORM WATCH OVER SOUTHEAST ZONES FOR SNOW
SATURDAY NIGHT THROUGH SUNDAY. THERE IS MODERATE CONFIDENCE
REGARDING ACCUMULATIONS. THE MAIN IMPACTS MAY BE TRAVEL RELATED AS
ALREADY ICY CONDITIONS HAVE BEEN REPORTED IN THE AREA.
A BIT MORE CERTAIN IS DANGEROUS WIND CHILLS MONDAY AND TUESDAY.
THEREFORE PLAN TO ISSUE A SEPARATE WATCH TO COVER THIS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 328 AM EST FRI JAN 3 2014
FORECAST CONCERNS DEAL WITH WIND CHILLS THIS MORNING AND THEN SNOW
POTENTIAL SATURDAY AND SUNDAY.
WINDS WILL PICK UP THIS AFTERNOON AS THE CLIPPER DRAGGING THE ARCTIC
FRONT APPROACHES. IN FACT...WINDS ALONG THE COAST MAY APPROACH
ADVISORY CRITERIA BUT FOR THE MOST PART SHOULD FALL JUST SHY. WIND
CHILLS THIS MORNING SHOULD BE IN THE 10 TO 15 BELOW RANGE FOR A FEW
HOURS BEFORE CLIMBING THIS AFTERNOON. SOME SNOW SHOWERS WILL ALSO
DEVELOP NORTH OF MUSKEGON AND WEST OF US-131 AS SW FLOW DEVELOPS BUT
ACCUMS SHOULD BE LESS THAN AN INCH AS MOISTURE IS A LIMITING FACTOR
ALONG WITH UPPER SHORT WAVE RIDGING.
SATURDAY WILL BE THE WARMEST DAY AS TEMPS MAKE A RUN AT 30 IN SW
FLOW AHEAD OF THE FRONT. HOWEVER...BREEZY CONDITIONS WILL MAKE IT
FEEL MUCH COLDER. THE ARCTIC FRONT WILL MOVE THROUGH THE CWA
SATURDAY AFTERNOON. LIGHT SNOW WILL ACCOMPANY THE FRONT. ACCUMS IN
THE 1 TO 3 INCH RANGE SEEM POSSIBLE. THERE IS SOME OMEGA IN THE DGZ
AS IT LOWERS THROUGH THE PERIOD FROM SATURDAY NIGHT THROUGH SUNDAY.
TEMPS WON/T MOVE MUCH SUNDAY AS STRONG COLD AIR ADVECTION WILL BE
UNDERWAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 AM EST FRI JAN 3 2014
THE DANGEROUSLY LOW WIND CHILLS FOR MONDAY THROUGH TUESDAY
MORNING CONTINUE TO BE THE WEATHER HIGHLIGHT IN THE LONG TERM.
WIND CHILL READINGS ON MONDAY AND MONDAY NIGHT AROUND -25 OR
COLDER WILL LIKELY NECESSITATE WIND CHILL WARNINGS FOR THE FIRST
DAY BACK TO SCHOOL.
SINCE WE WILL BE COLD ADVECTING LATE SUNDAY NIGHT AND ALL DAY
MONDAY... THE HIGH TEMP FOR MONDAY 1/6 WILL PROBABLY BE THE MIDNIGHT
READING. TEMPS ON MONDAY AFTERNOON MAY ACTUALLY FALL BELOW ZERO.
IF IT TURNS OUT THAT THE HIGH ON MONDAY IS ONLY AROUND ZERO... THIS
COULD BE IN THE TOP TEN COLDEST HIGH TEMPS AT LEAST AT GRR.
LAKE EFFECT SNOW SHOWERS AND BLOWING SNOW ALONG AND WEST OF HIGHWAY
131 MONDAY AND TUESDAY WILL BE ADDITIONAL HAZARDS EARLY NEXT WEEK
THAT MAY PRODUCE TRAVEL IMPACTS. THE VERY COLD TEMPS AND SNOW WILL
MAKE ROADS ICY AND CHEMICALS WILL PROBABLY BE INEFFECTIVE.
TOTAL LAKE EFFECT SNOW ACCUMULATIONS SHOULD BE RELATIVELY LIGHT
GIVEN THAT A DGZ WILL NOT BE PRESENT DUE TO THE VERY COLD AIR MASS.
THAT MAY BEGIN TO CHANGE BY TUESDAY AFTERNOON AS SLIGHT WARMING
ALLOWS THE DGZ TO RETURN TO THE CLOUD LAYER.
ALTHOUGH THE CORE OF THE COLDEST AIR LIFTS OUT ON TUESDAY... THE
SNOW THREAT CONTINUES INTO WEDNESDAY AND THURSDAY AS ANOTHER H5
TROUGH DIGS WEST OF MI AND MAY INDUCE WARM ADVECTION SNOWS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1254 PM EST FRI JAN 3 2014
VISIBILITIES BELOW A MILE AND CEILINGS UNDER 1000 FEET AT MUSKEGON
DUE TO A SNOWBAND... WILL IMPROVE TO VFR LEVELS OVER THE NEXT COUPLE
OF HOURS. ELSEWHERE... VFR CONDITIONS EXPECTED INTO SATURDAY.
GUSTY WINDS OUT OF THE SOUTH WILL INGREASE THIS AFTERNOON AND
TONIGHT WITH STEADY WINDS BY MORNING OF 20 KNOTS AND GUSTS TO AROUND
35 KNOTS POSSIBLE. WINDS NEAR THE LAKESHORE TONIGHT COULD GUST AS
HIGH AS 40 KNOTS AFTER 00Z.
&&
.MARINE...
ISSUED AT 856 PM EST THU JAN 2 2014
UPGRADED THE GALE WATCH TO A WARNING. CONFIDENCE IS PRETTY HIGH
THAT WINDS WILL REALLY PICK UP FRIDAY AFTERNOON FROM THE SOUTHWEST
AND REACH GALES LATE IN THE DAY.
&&
.HYDROLOGY...
ISSUED AT 236 PM EST THU JAN 2 2014
A FLOOD ADVISORY IS IN EFFECT FOR THE FLAT RIVER AT SMYRNA. A
SUSPECTED ICE JAM UPSTREAM IS CAUSING A SHARP RISE AT THE SMYRNA
RIVER GAUGE. THE ICE JAM ON THE MUSKEGON RIVER THAT HAS IMPACTED
EVART SEEMS TO HAVE STABILIZED. THE MUSKEGON RIVER AT EVART IS NOW
ON A GRADUAL DECLINE. THE FLOOD ADVISORIES FOR THE MUSKEGON RIVER AT
EVART AND THE PERE MARQUETTE RIVER AT SCOTTVILLE HAVE BEEN CANCELED.
RIVERS WILL CONTINUE GAINING ICE COVERAGE AND THICKNESS FOR THE
FORESEEABLE FUTURE. THOSE RIVERS THAT ICE OVER COMPLETELY WILL HAVE
A MINIMAL ICE JAM THREAT. RIVERS WITH JAGGED ICE BUILDUP ARE IN
DANGER OF EXPERIENCING JAMMING AND RAPID FLUCTUATIONS. WIDESPREAD
HEAVIER SNOW IS LIKELY SUNDAY AND SUNDAY NIGHT...FOLLOWED
IMMEDIATELY BY A BLAST OF EXTREMELY COLD AIR. HOPEFULLY RIVER LEVELS
WILL LOCK IN SOMEWHAT WITH THE COLD AIR IN PLACE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
LMZ844>849.
GALE WARNING UNTIL 1 PM EST SATURDAY FOR LMZ844>849.
&&
$$
UPDATE...TJT
SYNOPSIS...93
SHORT TERM...93
LONG TERM...MEADE
AVIATION...63
HYDROLOGY...EBW
MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1134 AM EST FRI JAN 3 2014
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 328 AM EST FRI JAN 3 2014
THE BIG WEATHER STORY THROUGH THE NEXT FEW DAYS WILL BE THE ARRIVAL
OF AN ARCTIC BLAST SATURDAY NIGHT AND THE CORE OF THE COLDEST AIR
COMING ON MONDAY AND TUESDAY. MEANTIME...WE/LL SEE SOME SUNSHINE
TODAY BEFORE LAKE CLOUDS DEVELOP. HOWEVER THE WIND IS GOING TO PICK
UP AND WHEN COMBINED WITH TEMPS IN THE TEENS WILL PRODUCE WIND
CHILLS IN THE 10 TO 15 BELOW RANGE EARLY TODAY. THE COLDEST AIR WILL
ARRIVE MONDAY AND TUESDAY. TEMPERATURES WILL STRUGGLE TO RISE ABOVE
0. WIND CHILLS 20 TO 30 BELOW SEEM LIKELY MONDAY AND TUESDAY. WARMER
AIR WILL ARRIVE BY THE END OF NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1104 AM EST FRI JAN 3 2014
DOMINANT LAKE SNOW BAND IS CURRENTLY MOVING ONSHORE NEAR
MUSKEGON...BUT BOTH RADAR AND SURFACE OBSERVATIONS SUGGEST THAT
THE INTENSITY IS WEAK.
REGARDING INCREASING WIND LATER TODAY...LATEST HRRR MODEL
GUIDANCE SUGGESTS THAT EXPOSED LAKESHORE AREAS TO THE NORTH
/I.E... THE SABLE POINTS/ COULD SEE WIND ADVISORY CRITERIA BEING
MET AT THE IMMEDIATE LAKESHORE. GIVEN A WIND DIRECTION GENERALLY
FROM THE SOUTH...DO NOT EXPECT MUCH INLAND EXTENT TO THE STRONGEST
WINDS SO DO NOT PLAN TO ISSUE A WIND ADVISORY.
AFTER DISCUSSION WITH THE DETROIT AND NORTHERN INDIANA OFFICES...
WILL BE ISSUING A WINTER STORM WATCH OVER SOUTHEAST ZONES FOR SNOW
SATURDAY NIGHT THROUGH SUNDAY. THERE IS MODERATE CONFIDENCE
REGARDING ACCUMULATIONS. THE MAIN IMPACTS MAY BE TRAVEL RELATED AS
ALREADY ICY CONDITIONS HAVE BEEN REPORTED IN THE AREA.
A BIT MORE CERTAIN IS DANGEROUS WIND CHILLS MONDAY AND TUESDAY.
THEREFORE PLAN TO ISSUE A SEPARATE WATCH TO COVER THIS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 328 AM EST FRI JAN 3 2014
FORECAST CONCERNS DEAL WITH WIND CHILLS THIS MORNING AND THEN SNOW
POTENTIAL SATURDAY AND SUNDAY.
WINDS WILL PICK UP THIS AFTERNOON AS THE CLIPPER DRAGGING THE ARCTIC
FRONT APPROACHES. IN FACT...WINDS ALONG THE COAST MAY APPROACH
ADVISORY CRITERIA BUT FOR THE MOST PART SHOULD FALL JUST SHY. WIND
CHILLS THIS MORNING SHOULD BE IN THE 10 TO 15 BELOW RANGE FOR A FEW
HOURS BEFORE CLIMBING THIS AFTERNOON. SOME SNOW SHOWERS WILL ALSO
DEVELOP NORTH OF MUSKEGON AND WEST OF US-131 AS SW FLOW DEVELOPS BUT
ACCUMS SHOULD BE LESS THAN AN INCH AS MOISTURE IS A LIMITING FACTOR
ALONG WITH UPPER SHORT WAVE RIDGING.
SATURDAY WILL BE THE WARMEST DAY AS TEMPS MAKE A RUN AT 30 IN SW
FLOW AHEAD OF THE FRONT. HOWEVER...BREEZY CONDITIONS WILL MAKE IT
FEEL MUCH COLDER. THE ARCTIC FRONT WILL MOVE THROUGH THE CWA
SATURDAY AFTERNOON. LIGHT SNOW WILL ACCOMPANY THE FRONT. ACCUMS IN
THE 1 TO 3 INCH RANGE SEEM POSSIBLE. THERE IS SOME OMEGA IN THE DGZ
AS IT LOWERS THROUGH THE PERIOD FROM SATURDAY NIGHT THROUGH SUNDAY.
TEMPS WON/T MOVE MUCH SUNDAY AS STRONG COLD AIR ADVECTION WILL BE
UNDERWAY.
.LONG TERM...(SUNDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 AM EST FRI JAN 3 2014
THE DANGEROUSLY LOW WIND CHILLS FOR MONDAY THROUGH TUESDAY
MORNING CONTINUE TO BE THE WEATHER HIGHLIGHT IN THE LONG TERM.
WIND CHILL READINGS ON MONDAY AND MONDAY NIGHT AROUND -25 OR
COLDER WILL LIKELY NECESSITATE WIND CHILL WARNINGS FOR THE FIRST
DAY BACK TO SCHOOL.
SINCE WE WILL BE COLD ADVECTING LATE SUNDAY NIGHT AND ALL DAY
MONDAY... THE HIGH TEMP FOR MONDAY 1/6 WILL PROBABLY BE THE MIDNIGHT
READING. TEMPS ON MONDAY AFTERNOON MAY ACTUALLY FALL BELOW ZERO.
IF IT TURNS OUT THAT THE HIGH ON MONDAY IS ONLY AROUND ZERO... THIS
COULD BE IN THE TOP TEN COLDEST HIGH TEMPS AT LEAST AT GRR.
LAKE EFFECT SNOW SHOWERS AND BLOWING SNOW ALONG AND WEST OF HIGHWAY
131 MONDAY AND TUESDAY WILL BE ADDITIONAL HAZARDS EARLY NEXT WEEK
THAT MAY PRODUCE TRAVEL IMPACTS. THE VERY COLD TEMPS AND SNOW WILL
MAKE ROADS ICY AND CHEMICALS WILL PROBABLY BE INEFFECTIVE.
TOTAL LAKE EFFECT SNOW ACCUMULATIONS SHOULD BE RELATIVELY LIGHT
GIVEN THAT A DGZ WILL NOT BE PRESENT DUE TO THE VERY COLD AIR MASS.
THAT MAY BEGIN TO CHANGE BY TUESDAY AFTERNOON AS SLIGHT WARMING
ALLOWS THE DGZ TO RETURN TO THE CLOUD LAYER.
ALTHOUGH THE CORE OF THE COLDEST AIR LIFTS OUT ON TUESDAY... THE
SNOW THREAT CONTINUES INTO WEDNESDAY AND THURSDAY AS ANOTHER H5
TROUGH DIGS WEST OF MI AND MAY INDUCE WARM ADVECTION SNOWS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 658 AM EST FRI JAN 3 2014
WITH THE EXCEPTION OF MKG... VFR LIKELY TODAY AND TONIGHT WITH
INCREASING WINDS FROM THE SOUTH. WINDS THIS AFTERNOON WILL BEGIN
GUSTING TO 20-25 KNOTS BUT THE STRONGEST WINDS WILL BE TONIGHT
WHEN GUSTS TO 25-30 KNOTS ARE EXPECTED.
AT MKG... A BAND OF DISSIPATING LAKE EFFECT SNOW WILL COME ONSHORE
AROUND MID MORNING BRINGING MVFR VSBYS AND CIGS... AND POSSIBLY A
PERIOD OF IFR. THE SNOW SHOWERS SHOULD DISSIPATE COMPLETELY BY MID
AFTERNOON. WINDS AT THE LAKESHORE TONIGHT COULD GUST AS HIGH AS 40
KTS AT TIMES AFTER 00Z.
&&
.MARINE...
ISSUED AT 856 PM EST THU JAN 2 2014
UPGRADED THE GALE WATCH TO A WARNING. CONFIDENCE IS PRETTY HIGH
THAT WINDS WILL REALLY PICK UP FRIDAY AFTERNOON FROM THE SOUTHWEST
AND REACH GALES LATE IN THE DAY.
&&
.HYDROLOGY...
ISSUED AT 236 PM EST THU JAN 2 2014
A FLOOD ADVISORY IS IN EFFECT FOR THE FLAT RIVER AT SMYRNA. A
SUSPECTED ICE JAM UPSTREAM IS CAUSING A SHARP RISE AT THE SMYRNA
RIVER GAUGE. THE ICE JAM ON THE MUSKEGON RIVER THAT HAS IMPACTED
EVART SEEMS TO HAVE STABILIZED. THE MUSKEGON RIVER AT EVART IS NOW
ON A GRADUAL DECLINE. THE FLOOD ADVISORIES FOR THE MUSKEGON RIVER AT
EVART AND THE PERE MARQUETTE RIVER AT SCOTTVILLE HAVE BEEN CANCELED.
RIVERS WILL CONTINUE GAINING ICE COVERAGE AND THICKNESS FOR THE
FORESEEABLE FUTURE. THOSE RIVERS THAT ICE OVER COMPLETELY WILL HAVE
A MINIMAL ICE JAM THREAT. RIVERS WITH JAGGED ICE BUILDUP ARE IN
DANGER OF EXPERIENCING JAMMING AND RAPID FLUCTUATIONS. WIDESPREAD
HEAVIER SNOW IS LIKELY SUNDAY AND SUNDAY NIGHT...FOLLOWED
IMMEDIATELY BY A BLAST OF EXTREMELY COLD AIR. HOPEFULLY RIVER LEVELS
WILL LOCK IN SOMEWHAT WITH THE COLD AIR IN PLACE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
LMZ844>849.
GALE WARNING UNTIL 1 PM EST SATURDAY FOR LMZ844>849.
&&
$$
UPDATE...TJT
SYNOPSIS...93
SHORT TERM...93
LONG TERM...MEADE
AVIATION...MEADE
HYDROLOGY...EBW
MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1124 PM EST THU JAN 2 2014
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 236 PM EST THU JAN 2 2014
THE BIG WEATHER STORY IS THE COLD OUTBREAK EXPECTED EARLY NEXT WEEK.
HIGHS IN THE SINGLE DIGITS AND LOWS IN THE 0 TO 10 BELOW RANGE ARE
EXPECTED. WIND CHILLS COULD DROP AS LOW AS 25 BELOW ON MONDAY AND
TUESDAY. WIND GUSTS ARE FORECAST TO BE AROUND 20 TO 30 MPH.
ANOTHER VERY COLD NIGHT IS IN STORE TONIGHT WITH LOWS IN THE 0 TO
5 BELOW RANGE. SOME LIGHT SNOW NEAR THE LAKESHORE IS POSSIBLE
FRIDAY. WIDESPREAD HEAVIER SNOW WILL MOVE IN SUNDAY AND SUNDAY
NIGHT. SIGNIFICANT ACCUMULATIONS APPEAR LIKELY AT THIS
TIME...ESPECIALLY SOUTH AND EAST OF GRAND RAPIDS.
TEMPERATURES WILL MODERATE CONSIDERABLY ON SATURDAY BEFORE THE
ARCTIC AIR PLUNGES BACK IN. HIGHS ON SATURDAY WILL BE NEAR 30
DEGREES.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 303 PM EST THU JAN 2 2014
MAIN CHALLENGE IN THE VERY SHORT TERM IS ASSESSING SNOW POTENTIAL
NEAR THE LAKESHORE...PARTICULARLY AROUND THE SABLE POINTS OF MASON
AND OCEANA COUNTIES. A DOMINANT LAKE SNOW BAND NEAR THE WESTERN LAKE
MICHIGAN SHORELINE THIS MORNING IS SLOWLY DRIFTING EAST. THE LAST
SEVERAL HRRR MODEL RUNS...AS WELL AS THE NAM...APPEAR TO BE PLACING
OR MOVING THIS FEATURE TOO FAR EAST TOWARDS THE POINTS.
IT IS LOOKING MORE LIKELY THAT WE WILL CLEAR OUT OVER INLAND ZONES
TONIGHT...ALLOWING FOR VERY COLD INLAND TEMPERATURES FRIDAY MORNING
AND A LAND BREEZE THAT HAS A GOOD CHANCE OF KEEPING THE SNOW BAND
OFFSHORE. DISCUSSED THIS WITH THE GAYLORD OFFICE AND WE BOTH CONCUR
THAT THIS IS THE MOST LIKELY SCENARIO AT THIS POINT. HAVE THEREFORE
TRIMMED POPS AND ACCUMULATIONS EXCEPT FOR THE IMMEDIATE COAST.
STILL LOOKING FAVORABLE FOR LIGHT LAKE ENHANCED SNOW FRIDAY AHEAD OF
THE NEXT CLIPPER. DID NOT CHANGE THE INHERITED FORECAST
SIGNIFICANTLY. FROM FRIDAY NIGHT THROUGH SATURDAY POPS INCREASE FROM
NORTHWEST TO SOUTHEAST AHEAD OF THE CLIPPER AND ASSOCIATED COLD
FRONT WHICH SHOULD BE ENTERING THE FORECAST AREA BY SATURDAY EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM EST THU JAN 2 2014
THE MEDIUM RANGE MODELS CONTINUE IN GOOD AGREEMENT ON THE LARGE
SCALE FLOW WITH MINOR DIFFERENCES IN THE SMALLER SCALE FEATURES.
CONFIDENCE IS HIGH DUE TO CONTINUITY IN TIME AND SPACE. WIND CHILL
VALUES AND SNOWFALL ARE THE CHALLENGES WITH THIS FORECAST PACKAGE.
TEMPERATURES WILL FALL TO 0-5 DEGREES SUNDAY NIGHT AND ON MONDAY THE
HIGHS WILL BE AROUND 5 DEGREES ABOVE ZERO. THE LOWS MONDAY NIGHT
WILL BE BELOW ZERO. VALUES THIS LOW HAVE NOT BEEN SEEN IN THIS AREA
SINCE FEB 2007. THE TEMPERATURES WILL BEGIN TO RECOVER WEDNESDAY.
ALONG WITH THE COLD AIR... STRONG GUSTY WINDS OUT OF THE WEST AND
NORTHWEST WILL PRODUCE LOW WIND CHILL VALUES. THE COLDEST WIND
CHILLS... BETWEEN 20 AND 30 DEGREES BELOW ZERO ARE POSSIBLE MONDAY
EVENING INTO TUESDAY MORNING. A WIND CHILL ADVISORY AND MAYBE A WIND
CHILL WARNING WILL BE NEEDED MONDAY AFTERNOON THROUGH TUESDAY
AFTERNOON.
THIS ALSO SEEMS TO BE A SNOWY PERIOD OF TIME. AN UPPER LOW WILL DROP
SOUTH FROM NEAR THE POLE AND MOVE EAST ACROSS SOUTHERN CANADA THROUGH
THE LONG TERM. THIS AND SHORTWAVES MOVING THROUGH THE FLOW AROUND
THE LOW WILL BRING THE COLD AIR... CYCLONIC FLOW AND SNOW. A FEW
SHORTWAVES SHOULD PASS CLOSE ENOUGH TO THE AREA TO RESULT IN SNOW
SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE UPPER LOW WILL HELP TO BUMP
UP THE LAKE EFFECT SNOW MONDAY INTO WEDNESDAY AS THE SYSTEM PULLS
AWAY. WITH THE COLD TEMPERATURES... THE LAKE EFFECT SNOW IS EXPECTED
TO BE IN THE FORM OF SMALL ICE CRYSTALS. THEREFORE THE SNOW WILL NOT
STACK UP... BUT THE STRONG WINDS WILL BLOW THIS SNOW AROUND. THIS
WILL RESULT IN GREATLY REDUCED VISIBILITIES. THIS WILL ESPECIALLY BE
TRUE NEAR LAKE MICHIGAN.
A MORE ZONAL FLOW PATTERN WILL ENSUE WEDNESDAY... AS A LOW PRESSURE
SYSTEM BEGINS MOVING BY TO THE SOUTH OF THE REGION. THIS HAS THE
POTENTIAL FOR ADDITIONAL SNOWFALL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1121 PM EST THU JAN 2 2014
CLEARING SKIES CONTINUE FOR MUCH OF SOUTHWEST LOWER MICHIGAN. THIS
WILL ALLOW FOR MAINLY VFR WEATHER AT THE TAF SITES FOR MUCH OF THE
NIGHT. ALONG THE COAST NEAR KMKG CONDITIONS WILL LOWER TO MVFR/IFR
FRIDAY AM AS A BAND OF SNOW PUSHES IN FROM THE WEST.
WINDS WILL INCREASE AS WE GO THROUGH FRIDAY. STRONGEST VALUES WILL
OCCUR ON THE LAKESHORE WHERE VALUES WILL EASILY TOP 25 KNOTS
DURING THE AFTERNOON.
&&
.MARINE...
ISSUED AT 856 PM EST THU JAN 2 2014
UPGRADED THE GALE WATCH TO A WARNING. CONFIDENCE IS PRETTY HIGH
THAT WINDS WILL REALLY PICK UP FRIDAY AFTERNOON FROM THE SOUTHWEST
AND REACH GALES LATE IN THE DAY.
&&
.HYDROLOGY...
ISSUED AT 236 PM EST THU JAN 2 2014
A FLOOD ADVISORY IS IN EFFECT FOR THE FLAT RIVER AT SMYRNA. A
SUSPECTED ICE JAM UPSTREAM IS CAUSING A SHARP RISE AT THE SMYRNA
RIVER GAUGE. THE ICE JAM ON THE MUSKEGON RIVER THAT HAS IMPACTED
EVART SEEMS TO HAVE STABILIZED. THE MUSKEGON RIVER AT EVART IS NOW
ON A GRADUAL DECLINE. THE FLOOD ADVISORIES FOR THE MUSKEGON RIVER AT
EVART AND THE PERE MARQUETTE RIVER AT SCOTTVILLE HAVE BEEN CANCELED.
RIVERS WILL CONTINUE GAINING ICE COVERAGE AND THICKNESS FOR THE
FORESEEABLE FUTURE. THOSE RIVERS THAT ICE OVER COMPLETELY WILL HAVE
A MINIMAL ICE JAM THREAT. RIVERS WITH JAGGED ICE BUILDUP ARE IN
DANGER OF EXPERIENCING JAMMING AND RAPID FLUCTUATIONS. WIDESPREAD
HEAVIER SNOW IS LIKELY SUNDAY AND SUNDAY NIGHT...FOLLOWED
IMMEDIATELY BY A BLAST OF EXTREMELY COLD AIR. HOPEFULLY RIVER LEVELS
WILL LOCK IN SOMEWHAT WITH THE COLD AIR IN PLACE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR LMZ844>849.
GALE WARNING FROM 1 PM FRIDAY TO 1 PM EST SATURDAY FOR
LMZ844>849.
&&
$$
SYNOPSIS...EBW
SHORT TERM...TJT
LONG TERM...63
AVIATION...MJS
HYDROLOGY...EBW
MARINE...93
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
328 PM CST FRI JAN 3 2014
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 328 PM CST FRI JAN 3 2014
BEFORE THE MAIN SURGE OF EXTREMELY COLD AIR ARRIVES OVER THE
WEEKEND...A STRONG STORM SYSTEM AHEAD OF THIS AIR MASS HAS MODIFIED
ENOUGH TO PRODUCE A PERIOD OF FREEZING RAIN AND SLEET THIS EVENING
AS IT MOVES FROM THE WESTERN DAKOTAS...EASTWARD ACROSS THE UPPER
MIDWEST OVERNIGHT. REGIONAL RADAR ALSO ALREADY INDICATED A LARGE
AREA OF PRECIPITATION DEVELOPING ACROSS CENTRAL ND...SOUTHWARD INTO
CENTRAL SD. ABV THE SFC...TEMPS HAVE WARMED SIGNIFICANTLY...WITH 85H
TEMPS NEAR +6C IN WC MN TO NEAR 0C IN EC MN. HOWEVER...IN THE LOWEST
1-2K...TEMPS WERE NEAR -10C IN EC MN...TO -4C IN WC MN. THE DEPTH OF
THE COLDER TEMPS IN EASTERN MN WILL ALLOW FOR MAINLY SLEET AND SOME
-SN. HOWEVER...FURTHER TO THE WEST...THE PRECIPITATION HAS A BETTER
CHC OF HOLDING AS LIQUID AND NOT REFREEZING IN THE FORM OF SLEET.
THEREFORE...A BETTER CHC OF FREEZING RAIN IS EXPECTED IN WC MN
DURING THE EVENING HRS BEFORE THE ARCTIC FRONT ARRIVES AFT MIDNIGHT.
DEPENDING UPON HOW MUCH FURTHER THE WARMER AIR ADVECTS TO THE
EAST...WILL DEPEND IF EASTERN MN GETS MORE FREEZING RAIN OR SLEET.
WC WI WILL LIKELY REMAIN SNOW OR A MIXTURE OF SLEET AND SNOW. QPF
AMTS REMAIN FAIRLY LIGHT...BUT EVEN A FEW HUNDREDTHS OF AN INCH OF
FREEZING RAIN CAN CAUSE HAZARDOUS ROADS IF NOT TREATED. A WINTER WX
ADV WAS ISSUED BASED ON THE FREEZING PRECIPITATION AND THEN BLOWING
AND DRIFTING SNOW AFTER MIDNIGHT. ONLY SMALL CHGS IN THE FORECAST ON
SATURDAY AS TEMPS WILL CONTINUE TO FALL THROUGHOUT THE DAY. WIND
CHILL VALUES BY LATE SATURDAY AFTERNOON WILL RANGE FROM -30 TO -35F
IN CENTRAL/WC MN...TO AROUND -15 IN WC WI.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 328 PM CST FRI JAN 3 2014
THE WORST ARCTIC OUTBREAK SO FAR THIS COLD SEASON WILL BE UNDERWAY
AT THE START OF THE LONG TERM. DETERMINISTIC SOLUTIONS CONTINUE TO
DRIVE A POLAR VORTEX... CURRENTLY OVER THE YUKON... TO NEAR KDLH BY
SUNDAY EVENING... WITH 1000-500MB THICKNESS VALUES BELOW 486
(DAM). VERTICAL PROFILES BETWEEN THE SURFACE AND 850MB SHOW
TEMPERATURES IN THE -30 TO -35 DEG C RANGE ACROSS THE CWA SUNDAY
NIGHT AND MONDAY. THIS UPCOMING COLD IS QUITE SIMILAR PATTERN-WISE TO
THAT IN EARLY JANUARY 1982. A CHECK ON WEATHER MAPS DURING THAT
COLD OUTBREAK SHOWED THE UPPER LOW BOTTOMING OUT ACROSS THE UPPER
GREAT LAKES ALONG WITH THE SURFACE HIGH STAYING WELL WEST AND
SOUTH OF THE FA. THIS RESULTS IN THE LIKELYHOOD OF SOME CLOUDINESS
DUE TO PROXIMITY OF THE UPPER LOW AND ALSO A NW WIND FROM 10 TO
20 MPH IN THE HEART OF THE ARCTIC COLD. MSP DURING THE COLD WAVE
IN EARLY JANUARY 1982 HAD A LOW TEMPERATURES OF -26 DEG F. IN
FACT...LOWS ACROSS THE ENTIRE FA REACHED -25 TO -32 DEG F. THIS IS
VERY SIMILAR THE FORECAST VALUES AHEAD.
TODAY/S FORECAST HAS LOWS DROPPING BELOW ZERO SATURDAY EVENING AND
NOT RISING ABOVE ZERO UNTIL WEDNESDAY. THIS IS A RUN OF 88 HOURS
BELOW ZERO FOR MSP. NOT A TOP 10 RECORD... WHICH RUNS FROM 186
HOURS DOWN TO 130 HOURS. THE WORST STRETCH OF COLD IS FROM SUNDAY
NIGHT THROUGH TUESDAY. LOWS SUNDAY NIGHT ARE FORECAST IN THE -25
TO -32 DEG F RANGE... WITH -27 FOR MSP (THIS WOULD TIE THE RECORD).
THIS WOULD ALSO BE THE COLDEST MSP HAS BEEN SINCE DECEMBER 26TH
1996. THE ECE AND GFS MOS FOR MSP ARE -27 AND -29 DEG F
RESPECTIVELY. THEN HAVE THE POTENTIAL FOR RECORD LOW HIGHS ON
MONDAY WITH VALUES ONLY FORECAST IN THE -14 TO -20 DEG F RANGE. WE
HAVE MSP AT -17 FOR THE HIGH ON MONDAY WHICH WOULD BE A RECORD LOW
HIGH (-14). MONDAY NIGHT WE ARE BACK DOWN IN THE -20 TO -26 DEG F
RANGE WITH HIGHS ON TUESDAY IN THE SINGLE DIGITS BELOW ZERO.
AS MENTIONED EARLIER...NW WINDS WILL BE BLOWING THE WHOLE TIME.
WIND CHILL VALUES SUNDAY NIGHT AND MONDAY WILL BE IN THE -50 TO
-60 DEG F RANGE WITH VALUES MONDAY NIGHT AND TUESDAY MORNING IN
THE -40 TO -50 DEG F RANGE. A WIND CHILL WARNING REMAINS IN EFFECT
FROM 6 PM SATURDAY UNTIL NOON ON TUESDAY.
THE BALANCE OF THE WORKWEEK WILL BE ONE OF TEMPERATURE MODERATION
AS THE FLOW BECOMES MORE WESTERLY. HIGHS INCREASE FROM THE SINGLE
DIGITS ABOVE ZERO ON WEDNESDAY TO THE UPPER 20S BY FRIDAY. THERE
IS SOME DISAGREEMENT BETWEEN THE GFS/GEM AND EC ON HOW CLOSE WE
WILL BE TO A SOUTHERN STREAM SNOW EVENT. THE GEM AND GFS WOULD
JUST NICK OUR EASTERN AND SOUTHERN AREAS WHILE THE EC WOULD BRING
THE SNOW THROUGH A NORTHERN STREAM FEATURE. COLLABORATION TODAY
WAS TO KEEP VERY SMALL POPS CONFINED TO AREAS EAST AND SOUTH OF
THE TWIN CITIES FOR WEDNESDAY/WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1200 PM CST FRI JAN 3 2014
MAIN CHG TO THIS AVIATION TAF PERIOD IS TO CONCENTRATE ON TIMING
OF THE FREEZING RAIN/SLEET DEVELOPMENT ACROSS WC MN/CENTRAL MN
TOWARD 22-00Z. OTHERWISE...THE NEXT 6 HRS WILL BE MAINLY IFR/MVFR
IN BLSN WITH CIGS HOLDING ARND 1K...TO LOCALLY 2-3K IN WC WI.
A WARM LAYER ABV THE SFC (85H) IS NOTED IN WESTERN MN... AND AS
FAR EAST AS AXN/MKT TO AEL BASED ON THE LATEST RAP AT 17Z. STRONG
WSW WINDS AT 85H WILL CONTINUE TO ADVECT THESE HIGHER TEMPS
EASTWARD INTO EASTERN MN BY 00Z. HOWEVER...THERE IS A SUBSTANTIAL
DEEP SUB-FREEZING LAYER BLW 90H WHICH WILL LEAD TO THE REFREEZING
OF THE PRECIPITATION. EC MN WILL LIKELY HOLD ONTO SLEET WITH
STC/RWF/AXN A PERIOD OF FZRA/PL THRU THE EVENING BEFORE CHG OVER
TO -SN AFT 6Z. DEPENDING UPON HOW MUCH PRECIPITATION DEVELOPS
ACROSS SD IN THE NEXT FEW HRS...WILL DEPEND UPON HOW MUCH
ACCUMULATION DEVELOPS. AM LEANING TOWARD AT LEAST 0.1 INCH OF ICE
AT AXN THIS EVENING...WITH LESSER AMTS AT STC/RWF. RNH/EAU SHOULD
STAY ALL SNOW...WITH A MIXTURE OF PL DURING THE LATE EVENING.
WINDS WILL REMAIN FROM THE S/SSW AND GUSTY THIS AFTN/OVERNIGHT...BEFORE
CHG TO THE SW/NW BY SATURDAY MORNING. CONFIDENCE IN FREEZING RAIN
IS MODERATE AT AXN/STC...WITH LOWER CONFIDENCE AT RWF.
KMSP...
THIS FORECAST IS BASED ON THE 85H TEMPS HOLD NEAR +2C AND THE
DEEPER LAYER OF TEMPS -10C BLW 90H WHICH WILL KEEP THE
PRECIPITATION IN THE FORM OF LIGHT SLEET OR SNOW. CONFIDENCE OF
FREEZING RAIN IS LOW AT THE AIRPORT...BUT IF ANY -FZRA
DEVELOPS...IT WOULD BE AFT 2Z. SOME LOWER VSBYS MAY OCCUR THIS
AFTN AS WINDS CONTINUE TO GUST UP TO 26 KTS. S/SSW WINDS CONTINUE
THIS AFTN/EVENING...BECOMING MORE SW TONIGHT...THEN W/NW SATURDAY
AFTN.
/OUTLOOK FOR KMSP/
SAT NIGHT...VFR. NORTHWEST WIND 10 TO 20 KT.
SUN THRU MON NIGHT...MVFR POSSIBLE. NORTHWEST WIND 10 TO 20 KT.
TUE...MVFR CEILINGS POSSIBLE EARLY. WEST WIND 10 TO 15 KT.
TUE NIGHT...VFR. WEST WIND 5 TO 10 KT BECOMING SOUTH.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR MNZ041-047-
048-054>057-064-065-067-073>077-082>085-091>093.
WIND CHILL WARNING FROM 6 PM SATURDAY TO NOON CST TUESDAY FOR
MNZ041>045-047>070-073>078-082>085-091>093.
WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR MNZ042>045-
049>053-058>063-066-068>070-078.
WI...WIND CHILL WARNING FROM 6 PM SATURDAY TO NOON CST TUESDAY FOR
WIZ014>016-023>028.
WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR WIZ014>016-
023>028.
&&
$$
SHORT TERM...JLT
LONG TERM...RAH
AVIATION...JLT
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1215 PM CST FRI JAN 3 2014
.UPDATE...
ISSUED AT 1012 AM CST FRI JAN 3 2014
A WINTER WEATHER ADVISORY HAS BEEN EXTENDED THROUGH MID AFTERNOON
FOR ALL OF WEST CENTRAL THROUGH SOUTH CENTRAL MN DUE TO BLOWING AND
DRIFTING SNOW CONCERNS. AN ADDITIONAL ADVISORY IS BEING CONSIDERED
FOR TONIGHT AND EARLY SATURDAY FOR MUCH OF THE CWA DUE TO MIXED
PRECIPITATION CONCERNS AHEAD OF THE INCOMING ARCTIC FRONT. DETAILS
ON THIS LATER.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 351 AM CST FRI JAN 3 2014
LATEST 11-3.9 MICRON IMAGERY SHOWS CLOUDS SPILLING DOWN THE WESTERN
RIDGE AND MOVING INTO THE AREA AT THE CURRENT TIME. THE SURFACE
RIDGE HAS SHIFTED TO THE EAST... ALLOWING WINDS TO BECOME
SOUTHERLY... WHICH WHEN COMBINED WITH THE INCREASED CLOUD COVER HAS
CAUSED TEMPERATURES TO BEGIN TO MOVE UPWARD ACROSS MUCH OF THE AREA.
THIS TREND WILL CONTINUE THROUGH THE DAY TODAY... AS ROBUST WARM
ADVECTION OCCURS ALOFT. SURFACE TEMPERATURES WILL RESPOND AS WELL...
BUT THEY HAVE A LONG WAY TO GO... AND LOOK TO ONLY HAVE A CHANCE OF
GETTING CLOSE TO FREEZING OVER THE WESTERN PORTION OF THE AREA.
HOWEVER... 850MB TEMPERATURES LOOK TO GET WELL ABOVE FREEZING LATER
THIS AFTERNOON INTO TONIGHT... WHICH WILL SPELL SOME
PRECIPITATION-TYPE ISSUES ACROSS THE AREA AS THE SURFACE LOW AND
COLD FRONT MOVE THROUGH THE REGION TONIGHT. AT THIS POINT... THE
BEST COMBINATION OF WARM ADVECTION AND SATURATION LOOK TO OCCUR OFF
TO OUR NORTH... BUT WE SHOULD SEE A WINDOW OF SOME LIGHT PCPN WITH
THE COLD FRONT AND DPVA AHEAD OF THE UPPER SHORTWAVE. KEPT BEST POPS
FROM LATE AFTERNOON THROUGH THE EVENING... WITH HIGHEST VALUES
ACROSS THE NORTH CENTRAL AND NORTHEAST PORTION OF THE FORECAST AREA.
WITH ABOVE FREEZING TEMPERATURES ALOFT AND BELOW FREEZING VALUES AT
AND NEAR THE SURFACE... BOTH SLEET AND SOME LIGHT FREEZING RAIN WILL
BE A POSSIBILITY WITH ANY PCPN THAT OCCURS. AS TEMPERATURES TURN
SHARPLY COLDER LATER TONIGHT... ANY LINGERING PCPN WILL CHANGE BACK
TO SNOW. AT THIS POINT... PCPN AMOUNTS LOOK LIGHT... AND IT IS TOUGH
TO SAY IF/WHERE ANYTHING GREATER THAN A TENTH OF AN INCH MIGHT
OCCUR. WITH THAT IN MIND... AM HOLDING OFF ON ISSUING ANY WINTER
WEATHER HEADLINES DUE TO MIXED PCPN. HOWEVER... PRIOR TO THE ARRIVAL
OF THE PCPN... WE WILL HAVE A PERIOD OF STRONG SOUTHERLY WINDS
TODAY... PARTICULARLY NEAR THE BUFFALO RIDGE. THIS SHOULD CAUSE SOME
BLOWING SNOW ISSUES FOR A GOOD PART OF THE DAY TODAY... SO WILL BE
ISSUING A WINTER WEATHER ADVISORY FOR THE FAR WEST-CENTRAL AND
SOUTHWEST PORTION OF THE AREA INTO MID-AFTERNOON. PATCHY BLOWING
SNOW WILL IMPACT MUCH OF THE REST OF THE AREA AT TIMES... AS WINDS
GUST NEAR 30 MPH. THERE COULD BE BLOWING SNOW CONCERNS ONCE AGAIN
LATE TONIGHT INTO SATURDAY BEHIND THE COLD FRONT... BUT THOSE COULD
BE MITIGATED BY ANY SLEET/FREEZING RAIN WHICH FALLS. NEEDLESS TO
SAY... THIS IS ANOTHER ITEM WHICH WILL NEED TO BE MONITORED... AND
WILL CERTAINLY BE MENTIONED IN THE FORECAST.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 351 AM CST FRI JAN 3 2014
THE FOCUS ON THE LONG TERM IS SQUARELY ON THE INTENSE...POSSIBLY
RECORD BREAKING COLD AIR OUTBREAK LATE THIS WEEKEND AND EARLY NEXT
WEEK. THIS HAS ALL THE MARKINGS OF A HISTORIC EVENT...AND A
FORECASTER IS LUCKY IF HE/SHE SEES ONE LIKE THIS IN THEIR ENTIRE
CAREER. SURPRISINGLY FOR SUCH AN EXTREME EVENT...THERE IS VERY
HIGH CONFIDENCE THROUGH EARLY NEXT WEEK OF IT OCCURRING...ASIDE
FROM SMALLER DETAILS SUCH AS WHETHER WE CAN BREAK ALL TIME COLD
RECORD HIGHS MONDAY. EVEN MOS IS CALLING FOR ALL TIME RECORD
HIGHS TO BE TIED OR BROKEN. A WIND CHILL WARNING HAS BEEN ISSUED
THROUGH THE COLD AIR OUTBREAK FOR THE 100 PERCENT CHANCE OF -35 OR
COLDER WIND CHILLS OCCURRING.
THE SOURCE REGION OF THIS AIR MASS IS IN NUNAVUT WHERE CURRENT
TEMPERATURES ARE AROUND -30. MODELS SHOW LITTLE OR NO MODERATION
AS THIS CHUNK OF ARCTIC AIR DIVES SOUTHEAST INTO THE UPPER MIDWEST
LATE THIS WEEKEND DUE TO LIMITED SUN AND CONTINUOUS SNOW PACK. THE
CORE OF THE COLDEST AIR WILL PASS DIRECTLY OVERHEAD LATE SUNDAY
AFTERNOON AND SUNDAY EVENING. GUIDANCE HAS BEEN RATHER STABLE IN
DEPICTING NEAR RECORD COLD AIR FOR SEVERAL RUNS. BOTH GFS AND
ECMWF MOS GUIDANCE ARE IN THE 25 TO 35 BELOW RANGE FOR LOWS SUNDAY
NIGHT AND HIGHS IN THE 15 TO 20 BELOW RANGE MONDAY. THE MOS
NUMBERS FOR MONDAY ARE BOLSTERED BY 925 MB TEMPS IN THE -29 TO
-34C RANGE WHICH WOULD ALSO TRANSLATE TO HIGHS IN THE UPPER TEENS
BELOW ZERO IF WE CAN EVEN MIX THAT DEEP. HAVE ADJUSTED THE GRIDS
DOWNWARD TO REFLECT THE GOOD CONSISTENCY. THE COLDEST HIGH EVER
RECORDED AT MSP IS -17F...OCCURRING WITH THE INFAMOUS COLD
OUTBREAKS OF 2/2/1996 AND 12/23/1983. THE FORECAST CURRENTLY CALLS
FOR THAT ALL TIME RECORD TO BE TIED. USUALLY FOR SUCH EXTREME
TEMPS TO OCCUR...CLEAR SKIES...CALM WINDS AND IDEAL RADIATIONAL
COOLING CONDITIONS WOULD BE NECESSARY. IT WILL NOT BE NECESSARY IN
THIS AIRMASS. IN FACT...CYCLONIC FLOW ALOFT MAY BRING CLOUDS AND
OCCASIONAL ICE CRYSTALS.
IF THE AIR TEMPERATURES WERE NOT IMPRESSIVE ENOUGH...PERHAPS THE
WIND ACCOMPANYING THE BITTER COLD AIR IS. NORTHWEST WINDS OF 10
TO 20 MPH THROUGHOUT THE OUTBREAK WILL LEAD TO WIND CHILLS
DROPPING TO 35 TO 50 BELOW...EXCEPT BETWEEN 50 AND 60 BELOW
SUNDAY NIGHT AND MONDAY MORNING. BOTTOM LINE...IT WILL BE
COLD...EXTREMELY COLD.
A COUPLE OTHER NOTES...BLOWING SNOW IS POSSIBLE AT TIMES THROUGH
EARLY NEXT WEEK - PARTICULARLY IMMEDIATELY BEHIND THE ARCTIC
BOUNDARIES IN WESTERN MINNESOTA WHERE WINDS MAY GUST TO 35 MPH.
MAY NEED A HEADLINE FOR THIS...BUT CONFIDENCE IS NOT HIGH ENOUGH
YET TO JUMP ON THAT.
BY MID TO LATE NEXT WEEK...MUCH MILDER AIR WILL PUSH EAST ACROSS
THE CONUS AS ZONAL FLOW TAKES OVER. THERE ARE STILL NO SIGNIFICANT
SNOW STORMS ON THE HORIZON.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1200 PM CST FRI JAN 3 2014
MAIN CHG TO THIS AVIATION TAF PERIOD IS TO CONCENTRATE ON TIMING
OF THE FREEZING RAIN/SLEET DEVELOPMENT ACROSS WC MN/CENTRAL MN
TOWARD 22-00Z. OTHERWISE...THE NEXT 6 HRS WILL BE MAINLY IFR/MVFR
IN BLSN WITH CIGS HOLDING ARND 1K...TO LOCALLY 2-3K IN WC WI.
A WARM LAYER ABV THE SFC (85H) IS NOTED IN WESTERN MN... AND AS
FAR EAST AS AXN/MKT TO AEL BASED ON THE LATEST RAP AT 17Z. STRONG
WSW WINDS AT 85H WILL CONTINUE TO ADVECT THESE HIGHER TEMPS
EASTWARD INTO EASTERN MN BY 00Z. HOWEVER...THERE IS A SUBSTANTIAL
DEEP SUB-FREEZING LAYER BLW 90H WHICH WILL LEAD TO THE REFREEZING
OF THE PRECIPITATION. EC MN WILL LIKELY HOLD ONTO SLEET WITH
STC/RWF/AXN A PERIOD OF FZRA/PL THRU THE EVENING BEFORE CHG OVER
TO -SN AFT 6Z. DEPENDING UPON HOW MUCH PRECIPITATION DEVELOPS
ACROSS SD IN THE NEXT FEW HRS...WILL DEPEND UPON HOW MUCH
ACCUMULATION DEVELOPS. AM LEANING TOWARD AT LEAST 0.1 INCH OF ICE
AT AXN THIS EVENING...WITH LESSER AMTS AT STC/RWF. RNH/EAU SHOULD
STAY ALL SNOW...WITH A MIXTURE OF PL DURING THE LATE EVENING.
WINDS WILL REMAIN FROM THE S/SSW AND GUSTY THIS AFTN/OVERNIGHT...BEFORE
CHG TO THE SW/NW BY SATURDAY MORNING. CONFIDENCE IN FREEZING RAIN
IS MODERATE AT AXN/STC...WITH LOWER CONFIDENCE AT RWF.
KMSP...
THIS FORECAST IS BASED ON THE 85H TEMPS HOLD NEAR +2C AND THE
DEEPER LAYER OF TEMPS -10C BLW 90H WHICH WILL KEEP THE
PRECIPITATION IN THE FORM OF LIGHT SLEET OR SNOW. CONFIDENCE OF
FREEZING RAIN IS LOW AT THE AIRPORT...BUT IF ANY -FZRA
DEVELOPS...IT WOULD BE AFT 2Z. SOME LOWER VSBYS MAY OCCUR THIS
AFTN AS WINDS CONTINUE TO GUST UP TO 26 KTS. S/SSW WINDS CONTINUE
THIS AFTN/EVENING...BECOMING MORE SW TONIGHT...THEN W/NW SATURDAY
AFTN.
/OUTLOOK FOR KMSP/
SAT NIGHT...VFR. NORTHWEST WIND 10 TO 20 KT.
SUN THRU MON NIGHT...MVFR POSSIBLE. NORTHWEST WIND 10 TO 20 KT.
TUE...MVFR CEILINGS POSSIBLE EARLY. WEST WIND 10 TO 15 KT.
TUE NIGHT...VFR. WEST WIND 5 TO 10 KT BECOMING SOUTH.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WINTER WEATHER ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR MNZ041-
047-048-054>057-064-065-067-073>077-082>085-091>093.
WIND CHILL WARNING FROM 6 PM SATURDAY TO NOON CST TUESDAY FOR
MNZ041>045-047>070-073>078-082>085-091>093.
WI...WIND CHILL WARNING FROM 6 PM SATURDAY TO NOON CST TUESDAY FOR
WIZ014>016-023>028.
&&
$$
UPDATE...RAH
SHORT TERM...
LONG TERM...BORGHOFF
AVIATION...JLT
AREA FORECAST DISCUSSION...UPDATED
NWS ST LOUIS MO
813 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 00z TAFs through 00z Sunday Evening)
Issued at 527 PM CST Sat Jan 4 2014
A number of uncertainties remain regarding this system. Mainly,
timing of onset precip and timing of heavier SN. Latest guidance
suggests that precip may begin as DZ/FZDZ or as a mix of RA/IP.
Actual precip may also end a little sooner than TAF suggests.
However, as visbys will likely stay within the MVFR range, or
perhaps lower, due to blowing snow, only added another group when
cigs are expected to lift. Will likely need to update later to
include better timing of heaviest SN. For now, heaviest SN shud
reach COU late tonight as the upper trof reaches the region. This
shud hold off for SUS/CPS until right around sunrise. UIN may also
not see the lowest visbys until near sunrise, but more uncertainty
exists. When the system exits, snowfall amounts around 4 inches
for COU/UIN and 10 to 12 inches for SUS/CPS.
Specifics for KSTL: Other than what is mentioned above, heaviest
SN shud reach terminal somewhere between 12z and 15z and shud
persist thru about 18z. Total snowfall is currently forecast
around 10 inches.
Tilly
&&
.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 from Midnight tonight to 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 from Midnight tonight to 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 GRAND FORKS ND
1020 AM CST FRI JAN 3 2014
.UPDATE...
ISSUED AT 945 AM CST FRI JAN 3 2014
NO CHANGES TO THIS UPDATE...AS WE ARE STILL TRYING TO GET TIMING
ON POTENTIAL BLIZZARD. THERE WILL BE AN AREA OF MIXED PRECIP
MOVING FROM WEST TO EAST THIS AFTERNOON...AND THIS COULD CREATE
ICY CONDITIONS. THIS IS HANDLED WELL AND NO CHANGES PLANNED.
SOUTHERLY WINDS SHOULD SLOWLY DECREASE AND BLOWING/DRIFTING SHOULD
DIMINISH IN THE VALLEY.
UPDATE ISSUED AT 701 AM CST FRI JAN 3 2014
FCST ON TRACK. DID ADJUST TEMPS SLIGHTLY THIS MORNING BUT OVERALL
THINGS SEEM OK. REPORT OF AROUND AN INCH OF NEW SNOW IN WARROAD-
BAUDETTE AREA. WINDS STARTING TO DIMINISH A BIT IN THE RRV AND
THIS TREND WILL CONTINUE THIS MORNING. WILL HAVE TO WATCH
DEVELOPMENT OF PRECIP IN ERN MT. LATEST RAP MORE AGGRESSIVE IN
BRINGING IN PRECIP SOUTH OF THE LOW THIS AFTN AND THIS COULD CAUSE
ISSUES IF HEAVY ENOUGH DUE TO FREEZING RAIN/SLEET CHANCES.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 318 AM CST FRI JAN 3 2014
MANY ISSUES TO START WITH. SURFACE LOW PRESSURE EAST OF CALGARY
ALBERTA ATTM AND THIS WILL TRACK AS EXPECTED TO NEAR GRAND FORKS
BY 00Z...THEN EAST THRU NRN MN TONIGHT. WARM ADVECTION LIGHT SNOWS
IN FAR NW MN WILL CONTINUE THIS MORNING BEFORE MORE SNOW ASSOC
WITH SFC LOW ARRIVES IN THAT AREA THIS AFTN-TONIGHT. COORD WITH
DLH AND BASED ON SNOWFALL FCST OF 3-5 INCHES IN ROSEAU-WARROAD-
BAUDETTE-WASKISH WILL GO WINTER WX ADVISORY 12Z FRI-12Z SAT.
SOUTH OF THE LOW TRACK EXPECT A WARM AIR SURGE EAST THIS AFTN INTO
THE DVL BASIN MIDDAY AND INTO THE RED RIVER VALLEY MID TO LATE
AFTN WITH TEMPS LOWER 30S IN DVL BASIN AND UPPER 20S-LOWER 30S IN
THE MID/SRN RRV. SOUTH OF THE LOW NOT MUCH PRECIP...BUT ALL MODELS
INDICATE SOME LIGHT PRECIP DEVELOPING AHEAD OF SHARPENING 500 MB
TROUGH IN SE ND INTO WCNTRL MN MID TO LATE AFTN. IN THIS WARMER
AIR ALOFT REGION...ANY PRECIP THAT FALLS WOULD BE OF A LIGHT
FREEZING RAIN/SLEET TYPE. AMOUNTS WILL BE LIGHT. NORTH OF THE LOW
SNOW WILL DROP INTO NRN ND MID AFTN INTO LATE AFTN. SFC LOW
POSITION NEAR GRAND FORKS AT 00Z WOULD MEAN NORTH-NORTHWEST WINDS
WILL BEGIN TO ENTER FAR NW FCST AREA-FAR NRN RRV AROUND 21-22Z AND
THEN SPREAD SOUTHWARD BEHIND THE LOW AFTER 00Z. GFS MODEL A BIT
MORE AGGRESSIVE WITH PRECIP/WIND THAN PAST RUNS AND 06Z NAM PRETTY
STRONG TOO AND WITH A SHARP SURGE OF COLD SFC-925 MB TEMPS AND
GOOD MIXED LAYER TO 925 MB WHERE WINDS WILL BE 45 KTS WOULD EXPECT
BLIZZARD CONDITIONS TO DEVELOP. BASED ON TIMING OF WINDS WILL
HOIST BLIZZARD WARNING FOR FAR NRN RRV/DVL BASIN STARTING AT 21Z
FRI THRU 15Z SAT. FOR THE REST OF THE RED RIVER VALLEY GRAND FORKS
SOUTHWARD BECAUSE OF START TIME NOT TIL AFTER 00Z...WILL KEEP
WATCH AND ALLOW DAYSHIFT TO FINE TUNE BEGINNING OF WARNING
HEADLINES. FRESH SNOWFALL WILL BE LIGHT IN THE NRN VALLEY WITH AN
INCH OR MAYBE TWO CANDO-GRAFTON-HALLOCK WITH THAT HEAVIER SNOWFALL
MORE TOWARD ROSEAU EASTWARD. FOR AREAS SOUTH OF HIGHWAY TWO
GENERALLY LESS THAN AN INCH. FOR AREAS OF MINNESOTA NOT IN LAKE OF
THE WOODS AREA NOR IN THE RED RIVER VALLEY (TVF-BJI SOUTHWARD)
COULD SEE WINTER WX ADVISORY CONDITIONS WITH SOME BLOWING
SNOW/SNOW SHOWERS TONIGHT BUT WILL LET LATER SHIFT DETERMINE
EXTENT AND TIMING OF THAT.
WINDS WILL SLOWLY SUBSIDE SATURDAY MORNING WITH BLOWING SNOW
CONDITIONS BECOME MORE LIMITED AND CLEARING WORKS IN. TEMPS WILL
FALL SLOWLY DURING THE DAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 318 AM CST FRI JAN 3 2014
CLEAR TO PARTLY CLOUDY SKY SAT NIGHT WILL LEAD TO A COLD NIGHT
WITH NORTHWEST WINDS HOLDING UP AND WIND CHILL WILL DROP INTO
ADVISORY AND THEN WARNING CRITERIA BY 12Z SUN.
FOR SUNDAY...EXPECT MAIN COLD SHOT AT LEAST AT 925-850 MB LAYER AS
UPPER LOW DROPS SOUTH. EXPECT AN INCREASE IN CLOUDS AND FLURRIES
TO MOVE IN FROM THE NORTH SUN-SUN NIGHT. WHILE CLOUDS WILL KEEP
LOW TEMPS SUN NIGHT FROM GOING OFF THE DEEP END...TIGHT GRADIENT
BETWEEN SFC LOW IN WESTERN QUEBEC AND HIGH PRESSURE IN ALBERTA-
SASK-MONTANA WILL CREATE A STIFF NORTHWEST BREEZE AND VERY LOW
WIND CHILLS. WILL ADDRESS WIND CHILL WARNINGS AS NEEDED ONCE THIS
BLIZZARD SYSTEM DEPARTS.
MONDAY THROUGH WEDNESDAY NIGHT...00 UTC GFS/ECMWF ARE IN GOOD
AGREEMENT. BOTH SHOW A DEEP TROUGH ACROSS THE EASTERN CONUS ON
MONDAY MOVING INTO EASTERN CANADA BY MID-WEEK WITH FLOW ALOFT
BECOMING MORE WESTERLY ACROSS THE NORTHERN PLAINS. WEAK SHORT-WAVES
WILL DROP SOUTH FROM CANADA...BUT WITH SURFACE HIGH PRESSURE AND
LITTLE MOISTURE...WILL KEEP THE FORECAST DRY. THE DEEP FREEZE WILL
CONTINUE ON MONDAY WITH HIGHS IN THE TEENS BELOW ZERO...BUT EXPECT
A GRADUAL WARMING TREND THEREAFTER AS A BUILDING RIDGE ACROSS THE
WESTERN CONUS SLOWLY TRANSLATES TO THE EAST. HIGHS BY WEDNESDAY
SHOULD RISE ABOVE ZERO WITH 850 HPA TEMPERATURES AROUND -12 C.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 701 AM CST FRI JAN 3 2014
VERY DIFFICULT AVIATION FORECAST. AREAS OF IFR CIGS AT FAR/GFK
MAINLY DUE TO BLOWING SNOW OVER THE SENSOR. OTHERWISE WITHOUT
BLOWING SNOW MOST CIGS IN THE LOW END VFR RANGE. VSYBS REDUCED IN
BLOWING SNOW TO 1-3SM IN THE RRV WILL IMPROVE TO P6SM AS WELL BY
LATE MORNING/MIDDAY AS WINDS DIMINISH. QUESTION IS CHANCE FOR
FREEZING PRECIP THIS AFTN ESP AT GFK/FAR. DID NOT INCLUDE IN TAF
DUE TO HIGH UNCERTAINTY ON WHEN/HOW MUCH. WINDS WILL TURN NORTH-
NORTHWEST WITH GUSTS TO 35 KTS (OR HIGHER) FOR A PERIOD THIS EVE
FROM NORTH TO SOUTH THROUGH DVL/RRV BASIN. CIGS LIKELY TO LOWER
AND VSBYS TOO TO IFR LEVELS IN THIS REGION. A BIT HIGHER VSBYS
BEMIDJI BUT STILL SOME SNOWFALL TONIGHT WITH IFR CIGS LATER
TONIGHT. FOR THIEF RIVER FALLS DUE TO CONTINUED CEILOMETER OUTAGE
AND AWAITING A REPLACEMENT WENT AMENDMENT NOT SCHEDULED (AMD NOT
SKED) DUE TO HIGH UNCERTAINTY OF CIGS TODAY-TONIGHT AND NO REAL
WAY TO CHECK IN REAL TIME, SO UPDATES WILL BE LIMITED TO GENERALLY
MAJOR TAF ISSUANCE TIMES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...BLIZZARD WATCH FROM 6 PM CST THIS EVENING THROUGH SATURDAY
MORNING FOR NDZ024-026>030-038-039-049-052-053.
BLIZZARD WARNING FROM 3 PM THIS AFTERNOON TO 9 AM CST SATURDAY
FOR NDZ006>008-014>016-054.
MN...BLIZZARD WATCH FROM 6 PM CST THIS EVENING THROUGH SATURDAY
MORNING FOR MNZ001>003-027-029-030-040.
BLIZZARD WARNING FROM 3 PM THIS AFTERNOON TO 9 AM CST SATURDAY
FOR MNZ004-007.
WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR MNZ005-006-
009.
&&
$$
UPDATE...DK
SHORT TERM...RIDDLE
LONG TERM...RIDDLE/ROGERS
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
710 AM CST FRI JAN 3 2014
.UPDATE...
ISSUED AT 701 AM CST FRI JAN 3 2014
FCST ON TRACK. DID ADJUST TEMPS SLIGHTLY THSI MORNING BUT OVERALL
THINGS SEEM OK. REPORT OF AROUND AN INCH OF NEW SNOW IN WARROAD-
BAUDETTE AREA. WINDS STARTING TO DIMINISH A BIT IN THE RRV AND
THIS TREND WILL CONTINUE THIS MORNING. WILL HAVE TO WATCH
DEVELOPMENT OF PRECIP IN ERN MT. LATEST RAP MORE AGGRESSIVE IN
BRINGING IN PRECIP SOUTH OF THE LOW THIS AFTN AND THIS COULD CAUSE
ISSUES IF HEAVY ENOUGH DUE TO FREEZING RAIN/SLEET CHANCES.
&&
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 318 AM CST FRI JAN 3 2014
MANY ISSUES TO START WITH. SURFACE LOW PRESSURE EAST OF CALGARY
ALBERTA ATTM AND THIS WILL TRACK AS EXPECTED TO NEAR GRAND FORKS
BY 00Z...THEN EAST THRU NRN MN TONIGHT. WARM ADVECTION LIGHT SNOWS
IN FAR NW MN WILL CONTINUE THIS MORNING BEFORE MORE SNOW ASSOC
WITH SFC LOW ARRIVES IN THAT AREA THIS AFTN-TONIGHT. COORD WITH
DLH AND BASED ON SNOWFALL FCST OF 3-5 INCHES IN ROSEAU-WARROAD-
BAUDETTE-WASKISH WILL GO WINTER WX ADVISORY 12Z FRI-12Z SAT.
SOUTH OF THE LOW TRACK EXPECT A WARM AIR SURGE EAST THIS AFTN INTO
THE DVL BASIN MIDDAY AND INTO THE RED RIVER VALLEY MID TO LATE
AFTN WITH TEMPS LOWER 30S IN DVL BASIN AND UPPER 20S-LOWER 30S IN
THE MID/SRN RRV. SOUTH OF THE LOW NOT MUCH PRECIP...BUT ALL MODELS
INDICATE SOME LIGHT PRECIP DEVELOPING AHEAD OF SHARPENING 500 MB
TROUGH IN SE ND INTO WCNTRL MN MID TO LATE AFTN. IN THIS WARMER
AIR ALOFT REGION...ANY PRECIP THAT FALLS WOULD BE OF A LIGHT
FREEZING RAIN/SLEET TYPE. AMOUNTS WILL BE LIGHT. NORTH OF THE LOW
SNOW WILL DROP INTO NRN ND MID AFTN INTO LATE AFTN. SFC LOW
POSITION NEAR GRAND FORKS AT 00Z WOULD MEAN NORTH-NORTHWEST WINDS
WILL BEGIN TO ENTER FAR NW FCST AREA-FAR NRN RRV AROUND 21-22Z AND
THEN SPREAD SOUTHWARD BEHIND THE LOW AFTER 00Z. GFS MODEL A BIT
MORE AGGRESSIVE WITH PRECIP/WIND THAN PAST RUNS AND 06Z NAM PRETTY
STRONG TOO AND WITH A SHARP SURGE OF COLD SFC-925 MB TEMPS AND
GOOD MIXED LAYER TO 925 MB WHERE WINDS WILL BE 45 KTS WOULD EXPECT
BLIZZARD CONDITIONS TO DEVELOP. BASED ON TIMING OF WINDS WILL
HOIST BLIZZARD WARNING FOR FAR NRN RRV/DVL BASIN STARTING AT 21Z
FRI THRU 15Z SAT. FOR THE REST OF THE RED RIVER VALLEY GRAND FORKS
SOUTHWARD BECAUSE OF START TIME NOT TIL AFTER 00Z...WILL KEEP
WATCH AND ALLOW DAYSHIFT TO FINE TUNE BEGINNING OF WARNING
HEADLINES. FRESH SNOWFALL WILL BE LIGHT IN THE NRN VALLEY WITH AN
INCH OR MAYBE TWO CANDO-GRAFTON-HALLOCK WITH THAT HEAVIER SNOWFALL
MORE TOWARD ROSEAU EASTWARD. FOR AREAS SOUTH OF HIGHWAY TWO
GENERALLY LESS THAN AN INCH. FOR AREAS OF MINNESOTA NOT IN LAKE OF
THE WOODS AREA NOR IN THE RED RIVER VALLEY (TVF-BJI SOUTHWARD)
COULD SEE WINTER WX ADVISORY CONDITIONS WITH SOME BLOWING
SNOW/SNOW SHOWERS TONIGHT BUT WILL LET LATER SHIFT DETERMINE
EXTENT AND TIMING OF THAT.
WINDS WILL SLOWLY SUBSIDE SATURDAY MORNING WITH BLOWING SNOW
CONDITIONS BECOME MORE LIMITED AND CLEARING WORKS IN. TEMPS WILL
FALL SLOWLY DURING THE DAY.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 318 AM CST FRI JAN 3 2014
CLEAR TO PARTLY CLOUDY SKY SAT NIGHT WILL LEAD TO A COLD NIGHT
WITH NORTHWEST WINDS HOLDING UP AND WIND CHILL WILL DROP INTO
ADVISORY AND THEN WARNING CRITERIA BY 12Z SUN.
FOR SUNDAY...EXPECT MAIN COLD SHOT AT LEAST AT 925-850 MB LAYER AS
UPPER LOW DROPS SOUTH. EXPECT AN INCREASE IN CLOUDS AND FLURRIES
TO MOVE IN FROM THE NORTH SUN-SUN NIGHT. WHILE CLOUDS WILL KEEP
LOW TEMPS SUN NIGHT FROM GOING OFF THE DEEP END...TIGHT GRADIENT
BETWEEN SFC LOW IN WESTERN QUEBEC AND HIGH PRESSURE IN ALBERTA-
SASK-MONTANA WILL CREATE A STIFF NORTHWEST BREEZE AND VERY LOW
WIND CHILLS. WILL ADDRESS WIND CHILL WARNINGS AS NEEDED ONCE THIS
BLIZZARD SYSTEM DEPARTS.
MONDAY THROUGH WEDNESDAY NIGHT...00 UTC GFS/ECMWF ARE IN GOOD
AGREEMENT. BOTH SHOW A DEEP TROUGH ACROSS THE EASTERN CONUS ON
MONDAY MOVING INTO EASTERN CANADA BY MID-WEEK WITH FLOW ALOFT
BECOMING MORE WESTERLY ACROSS THE NORTHERN PLAINS. WEAK SHORT-WAVES
WILL DROP SOUTH FROM CANADA...BUT WITH SURFACE HIGH PRESSURE AND
LITTLE MOISTURE...WILL KEEP THE FORECAST DRY. THE DEEP FREEZE WILL
CONTINUE ON MONDAY WITH HIGHS IN THE TEENS BELOW ZERO...BUT EXPECT
A GRADUAL WARMING TREND THEREAFTER AS A BUILDING RIDGE ACROSS THE
WESTERN CONUS SLOWLY TRANSLATES TO THE EAST. HIGHS BY WEDNESDAY
SHOULD RISE ABOVE ZERO WITH 850 HPA TEMPERATURES AROUND -12 C.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SATURDAY MORNING)
ISSUED AT 701 AM CST FRI JAN 3 2014
VERY DIFFICULT AVIATION FORECAST. AREAS OF IFR CIGS AT FAR/GFK
MAINLY DUE TO BLOWING SNOW OVER THE SENSOR. OTHERWISE WITHOUT
BLOWING SNOW MOST CIGS IN THE LOW END VFR RANGE. VSYBS REDUCED IN
BLOWING SNOW TO 1-3SM IN THE RRV WILL IMPROVE TO P6SM AS WELL BY
LATE MORNING/MIDDAY AS WINDS DIMINISH. QUESTION IS CHANCE FOR
FREEZING PRECIP THIS AFTN ESP AT GFK/FAR. DID NOT INCLUDE IN TAF
DUE TO HIGH UNCERTAINITY ON WHEN/HOW MUCH. WINDS WILL TURN NORTH-
NORTHWEST WITH GUSTS TO 35 KTS (OR HIGHER) FOR A PERIOD THIS EVE
FROM NORTH TO SOUTH THROUGH DVL/RRV BASIN. CIGS LIKELY TO LOWER
AND VSBYS TOO TO IFR LEVELS IN THIS REGION. A BIT HIGHER VSBYS
BEMIDJI BUT STILL SOME SNOWFALL TONIGHT WITH IFR CIGS LATER
TONIGHT. FOR THIEF RIVER FALLS DUE TO CONTINUED CEILOMETER OUTAGE
AND AWAITING A REPLACEMENT WENT AMENDMENT NOT SCHEDULED (AMD NOT
SKED) DUE TO HIGH UNCERTAINITY OF CIGS TODAY-TONIGHT AND NO REAL
WAY TO CHECK IN REAL TIME, SO UPDATES WILL BE LIMITED TO GENERALLY
MAJOR TAF ISSUANCE TIMES.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...BLIZZARD WATCH FROM 6 PM CST THIS EVENING THROUGH SATURDAY
MORNING FOR NDZ024-026>030-038-039-049-052-053.
BLIZZARD WARNING FROM 3 PM THIS AFTERNOON TO 9 AM CST SATURDAY
FOR NDZ006>008-014>016-054.
MN...BLIZZARD WATCH FROM 6 PM CST THIS EVENING THROUGH SATURDAY
MORNING FOR MNZ001>003-027-029-030-040.
BLIZZARD WARNING FROM 3 PM THIS AFTERNOON TO 9 AM CST SATURDAY
FOR MNZ004-007.
WINTER WEATHER ADVISORY UNTIL 6 AM CST SATURDAY FOR MNZ005-006-
009.
&&
$$
UPDATE...RIDDLE
SHORT TERM...RIDDLE
LONG TERM...RIDDLE/ROGERS
AVIATION...RIDDLE
AREA FORECAST DISCUSSION
NWS BISMARCK ND
103 AM CST FRI JAN 3 2014
.UPDATE...
ISSUED AT 102 AM CST FRI JAN 3 2014
ADDED A MENTION OF PATCHY BLOWING SNOW TO MUCH OF WESTERN AND
CENTRAL NORTH DAKOTA FOR THE REMAINDER OF THE NIGHT. THE 06-07 UTC
SOUTHERLY WINDS GUSTING TO 30 KTS ACROSS THE NORTH CENTRAL AND
JAMES RIVER VALLEY WILL CONTINUE...DUE IN LARGE PART TO NEAR 15
MB/6 HR PRESSURE FALLS AHEAD OF THE WARM FRONT ACROSS EASTERN
MONTANA. SOUTHWEST WINDS TO 30 KTS ARE EXPECTED AFTER 10 UTC
ACROSS THE SOUTHWEST IN THE WAKE OF THE WARM FRONT...WITH BLOWING
SNOW A THREAT UNTIL SURFACE TEMPERATURES WARM INTO THE MID 30S BY
MID MORNING.
UPDATE ISSUED AT 956 PM CST THU JAN 2 2014
ANOTHER QUICK UPDATE TO CLEAN UP POPS ACROSS CENTRAL NORTH DAKOTA.
LIGHT SNOW IS TAPERING OFF IN BISMARCK WITH 0.5 INCH ACCUMULATION
AT THE OFFICE. EXPECT LIGHT SNOW TO CONTINUE TO TAPER FROM WEST TO
EAST THROUGH THE REST OF THE EVENING. NEXT ROUND OF PRECIPITATION
IS EXPECTED TO MOVE INTO THE NORTH LATE TONIGHT AND CURRENT
FORECAST LOOKS REASONABLE HERE SO NO CHANGES. WILL UPDATE ALL
PRODUCTS SHORTLY.
UPDATE ISSUED AT 827 PM CST THU JAN 2 2014
WARM ADVECTION SNOW IS MORE ROBUST THAN INITIALLY THOUGHT ACROSS
CENTRAL NORTH DAKOTA. WILL UPDATE FLURRIES TO LIKELY TO
CATEGORICAL LIGHT SNOW THIS EVENING...MAINLY ALONG AND EAST OF
HIGHWAY 83. TWO TENTHS OF AN INCH OF LIGHT FLUFFY SNOW AT KBIS SO
FAR. THINK AMOUNTS WILL BE A HALF INCH OR LESS IN MOST AREAS. WITH
HIGHER SLR RATIOS IN THE EASTERN CWA...CANNOT RULE OUT SOME
REPORTS OF UP TO AN INCH FROM BOTTINEAU...RUGBY AREAS DOWN THROUGH
HARVEY AND CARRINGTON. UPDATED ZONES HAVE BEEN SENT.
UPDATE ISSUED AT 654 PM CST THU JAN 2 2014
LATEST RADAR LOOP IS INDICATING LIGHT WARM ADVECTION SNOW ACROSS
CENTRAL NORTH DAKOTA. LATEST RAP MESOSCALE MODEL DEPICTS LIGHT
REFLECTIVITIES TRACKING EAST ACROSS CENTRAL NORTH DAKOTA THIS
EVENING. FOR NOW WILL ADD A MENTION OF SCATTERED FLURRIES MAINLY
ALONG AND EAST OF THE HIGHWAY 83 CORRIDOR THROUGH THE EVENING.
OTHERWISE NO SIGNIFICANT CHANGES TO THE GOING FORECAST.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 259 PM CST THU JAN 2 2014
THE MAIN FORECAST ISSUE IS POTENTIAL BLIZZARD CONDITIONS
DEVELOPING FRIDAY AFTERNOON ACROSS THE NORTH.
IN THE NEAR TERM...HAVE EXPANDED AREA OF ISOLATED FLURRIES NORTH
AND WEST...AND CONTINUED FLURRIES LATER INTO THE EVENING IN THE
TURTLE MOUNTAIN AREA. WIND CHILL VALUES WILL BE BORDERLINE
ADVISORY CRITERIA THROUGH THIS EVENING FROM THE TURTLE MOUNTAINS
INTO THE JAMES RIVER VALLEY...BUT WILL COVER IN HAZARDOUS WEATHER
OUTLOOK IN ORDER TO AVOID CONFUSION FROM MULTIPLE HEADLINES.
12Z GFS/ECMWF ARE IN AGREEMENT WITH A STRONGER SURFACE GRADIENT
AND POTENTIAL FOR WIND GUSTS AROUND 40 MPH BEGINNING FRIDAY
AFTERNOON IN THE NORTH. THE NAM IS LESS ROBUST WITH WIND SPEEDS.
HOWEVER...COMPARING MODELS DURING THE RECENT BLIZZARD EVENT WITH
THE FRIDAY STORM...ALONG WITH CONSIDERATIONS OF THE FRESH SNOW
COVER...THE BALANCE TILTS TOWARD A BLIZZARD WATCH. STRONG WINDS
WILL LIKELY BE ABLE TO BREAK THROUGH ANY CRUST THAT DEVELOPS ON
THE LOOSE SNOW DURING THE WARM-UP FRIDAY. HAVE COVERED THE ENTIRE
FORECAST AREA IN THE WATCH. SNOWFALL AMOUNTS WILL BE AN INCH OR
TWO ACROSS THE NORTH...LESS THAN AN INCH CENTRAL AND SOUTH. THERE
IS POTENTIAL FOR SOME SLEET AND/OR FREEZING RAIN...BUT THE MAIN
TRAVEL HAZARD WILL BE BLOWING AND DRIFTING SNOW.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 259 PM CST THU JAN 2 2014
ACTIVE WEATHER IN TERMS OF A BLIZZARD WATCH ONGOING FROM FRIDAY
EVENING THROUGH SATURDAY MORNING...FOLLOWED BY LIFE THREATENING WIND
CHILL TEMPERATURES BETWEEN 50 AND 60 BELOW SATURDAY NIGHT THROUGH
TUESDAY MORNING.
A STRONG ARCTIC FRONT WILL SWEEP TO THE SOUTHERN BORDER BY 00Z
SATURDAY WITH A SHARP TRANSITION TO NORTHWEST WINDS AND POSSIBLY
ONGOING BLIZZARD CONDITIONS WITH VISIBILITIES LESS THAN ONE QUARTER
MILE. THE WINDS WILL BEGIN TO ABATE SATURDAY MORNING BUT REMAIN
BRISK AT 10 TO 20 MPH THROUGH SATURDAY NIGHT. BRUTAL H85 TEMPS OF
-35C TO -37C ACROSS WESTERN AND CENTRAL NORTH DAKOTA WILL ARRIVE
SUNDAY INTO MONDAY MORNING. ALONG WITH THAT WILL BE NORTHWEST
SURFACE WINDS OF 20 TO 30 MPH ASSOCIATED WITH THE COLDEST CHUNK OF
AIR. THAT WOULD PUT THE RISK OF FROSTBITE AND HYPOTHERMIA
POSSIBILITIES TO WITHIN 5 MINUTES OR LESS ON EXPOSED SKIN SURFACES.
A WIND CHILL WARNING HEADLINE WILL LIKELY BE HOISTED BY FRIDAY
AFTERNOON. NO SIGNIFICANT SNOWSTORMS DURING THE EXTREME COLD SNAP.
TEMPERATURES MODERATE BY WEDNESDAY AND THURSDAY...FROM WEST TO
EAST...WITH HIGHS 15 TO 25 ABOVE ON THURSDAY.
HIGHS SATURDAY WILL RANGE FROM 15 BELOW IN THE TURTLE MOUNTAINS TO 8
ABOVE IN THE SOUTHWEST. THE COLDEST AIR WILL ARRIVE SUNDAY THROUGH
MONDAY NIGHT WITH LOWS 15 BELOW TO 30 BELOW...AND HIGHS 15 BELOW TO
25 BELOW ZERO. THESE TEMPERATURES WHEN COMBINED WITH WINDS OF 20 TO
30 MPH WILL YIELD WIND CHILL TEMPERATURES OF 50 TO 60 BELOW.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 102 AM CST FRI JAN 3 2014
IFR STRATUS WITH LIGHT SNOW IS EXPECTED TO CONTINUE TO IMPACT KBIS
AND KJMS THROUGH AT LEAST 10 UTC. STRONG SOUTHERLY WINDS TO 30 KTS
TONIGHT AT KJMS WILL ALSO RESULT IN BLOWING SNOW. A STRONG STORM
SYSTEM WILL IMPACT WESTERN AND CENTRAL NORTH DAKOTA FRIDAY
AFTERNOON INTO SATURDAY MORNING. WIDESPREAD LIFR CONDITIONS WILL
DEVELOP WITH NORTHWEST WINDS TO 45KTS...LIGHT SNOW AND BLOWING
SNOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
BLIZZARD WATCH FROM THIS EVENING THROUGH SATURDAY MORNING FOR
NDZ018>023-025-031>037-040>048-050-051.
BLIZZARD WATCH FROM THIS AFTERNOON THROUGH SATURDAY MORNING FOR
NDZ001>005-009>013-017.
&&
$$
UPDATE...AYD
SHORT TERM...RP KINNEY
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1154 PM CST THU JAN 2 2014
.UPDATE...
ISSUED AT 1153 PM CST THU JAN 2 2014
MADE A FEW MINOR TWEAKS TO POPS TO REFLECT CURRENT TRENDS...SNOW
HAS BEEN MORE HIT AND MISS BUT BLOWING SNOW HAS STARTED GOING
ACROSS THE VALLEY. TEMPS WILL CONTINUE TO SLOWLY RISE OVERNIGHT AS
SOUTHERLY WINDS AND WARM AIR ADVECTION CONTINUES.
UPDATE ISSUED AT 937 PM CST THU JAN 2 2014
GIVEN RADAR RETURNS FROM MINOT AND SFC OBS OVER THE NORTH CENTRAL
PORTION OF ND...BUMPED UP POPS FOR THE REST OF THE EVENING INTO
THE PERIOD JUST AFTER MIDNIGHT. THE RAP AND NAM SEEM TO DO FAIRLY
WELL WITH THE GOING TRENDS...AND HAVE SOME PRECIP ALONG THE
LEADING EDGE OF THE WARM AIR ADVECTION. KEPT LIKELY POPS OVER THE
DEVILS LAKE BASIN DURING THE NEXT FEW HOURS...BUT TRANSITIONED TO
SLIGHTLY LOWER POPS LATER TONIGHT AS THE BAND MOVES EAST AS THE
MODELS AND RADAR TRENDS SHOW SOME WEAKENING. ANY ACCUMULATIONS
WILL BE VERY LIGHT. BLOWING SNOW MAY ALSO BE AN ISSUE...BUT NOT
SURE HOW WIDESPREAD IT WILL BE. WILL KEEP AN EYE ON WEB CAM TRENDS
FOR NOW AND WILL KEEP HEADLINES AS THEY ARE.
UPDATE ISSUED AT 644 PM CST THU JAN 2 2014
THROUGH IN A FLURRY MENTION AFTER 03Z AS THERE HAVE BEEN SOME SNOW
REPORTS IN NORTH CENTRAL ND AND THE RAP AND NAM SHOW SOME WEAK QPF
MOVING THROUGH THE DEVILS LAKE BASIN. THINK THAT ANYTHING
SIGNIFICANT WILL HOLD OFF UNTIL AFTER MIDNIGHT SO DID NOT MAKE ANY
CHANGES TO POPS FOR NOW. THE REST OF THE CWA SHOULD SEE INCREASING
CLOUDS THROUGH THIS EVENING AND EVENTUALLY RISING TEMPS...ALTHOUGH
THE EASTERN COUNTIES MAY BE STEADY FOR A WHILE UNTIL THE STRONGER
WARM AIR ADVECTION KICKS IN.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 225 PM CST THU JAN 2 2014
THE MAIN CHALLENGE WILL BE LIFE THREATENING WIND CHILLS AND
POTENTIAL BLIZZARD LATE FRIDAY AFTERNOON INTO SATURDAY MORNING.
MODELS ARE IN GOOD AGREEMENT AND PREFER THE CONSISTENT GFS/ECMWF
MIX THIS AFTERNOON.
FOR TONIGHT...SOUTHERLY WINDS WILL INCREASE AND THERE WILL BE
DANGEROUS WIND CHILLS TO 35 BELOW IN ALL AREAS. THERE WILL ALSO BE
30KT TO MIX FROM THE SOUTH IN THE VALLEY...AND BLOWING SNOW IS
LIKELY WITH VSBYS DOWN TO ONE MILE AT TIMES IN OPEN COUNTRY. TEMPS
WILL SLOWLY RISE WITH THE SOUTH WINDS. THERE COULD BE SOME LIGHT
SNOW IN THE FAR NORTH LATE...BUT MINIMAL ACCUMULATION EXPECTED.
ON FRIDAY/FRI NIGHT...SFC LOW PRESSURE WILL MOVE INTO THE CENTRAL
VALLEY BY 00Z. EXPECT A PERIOD OF MIXED PRECIP IN THE WARM
SECTOR...WITH SNOW IN THE FAR NORTH BY LATE AFTERNOON. WINDS WILL
SHIFT TO THE NORTH AND INCREASE IN THE FAR N/NW AFTER 21Z...WITH
POTENTIAL BLIZZARD CONDITIONS DEVELOPING AND MOVING SOUTH THROUGH
FRIDAY EVENING AND OVERNIGHT. THERE WILL BE ABOUT 40-45KT TO MIX
FROM 880MB PER THE GFS/ECMWF...WITH THE NAM A BIT WEAKER WITH THE
MIXED LAYER. GIVEN THAT THERE WILL BE FALLING SNOW...AND BLOWING
SNOW ADVECTING SOUTH...BLIZZARD CONDITIONS MAY DEVELOP IN THE
NORTHERN VALLEY AFTER 21Z FRI...MOVING INTO THE GFK AREA BY 2Z OR
SO THEN TO FARGO AFTER 3Z. FOR SIMPLICITY SAKE...WILL START THE
BLIZZARD WATCH IN THE NORTH AT 21Z FRI THEN POINTS SOUTH AT 00Z
SAT IN CASE FRONT SPEEDS UP A BIT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 225 PM CST THU JAN 2 2014
FOR SATURDAY...WINDS WILL REMAIN STRONG DURING THE MORNING WITH
30-35KT TO MIX UNTIL 18Z SAT. THEREFORE...BLOWING SNOW WILL REMAIN
A PROBLEM IN THE VALLEY WITH LIKELY FALLING TEMPS BELOW ZERO IN ALL
AREAS ON SATURDAY.
FOR SAT NIGHT/SUN...CONTINUED INTENSE COLD AIR ADVECTION WILL
CONTINUE WITH 925MB TEMPS FALLING TO -35C BY SUNDAY EVENING.
COUPLE THIS WITH TEMPS WELL BELOW ZERO AND 10-25MPH WINDS...LIFE
THREATENING WIND CHILLS TO 60 BELOW ARE POSSIBLE. THIS WILL BE A
DANGEROUS ARCTIC OUTBREAK GIVEN THE COMBINATION OF WIND
CHILLS...SOME FLURRIES POSSIBLE ON SUNDAY WITH AREAS OF
BLOWING/DRIFTING. CAUTION IS URGED BY ANYONE VENTURING OUTDOORS
DURING THIS TIMEFRAME.
FOR MON-THU...THE LONG TERM WILL START OUT WITH A NORTHERLY FLOW
PATTERN ALOFT CONTINUING TO HOLD A FRIGID ARCTIC AIR MASS IN
PLACE...BRINGING WELL BELOW AVG TEMPS TO THE AREA EARLY IN THE
WEEK. AN UPPER WAVE DROPS INTO THE DAKOTAS TUE NIGHT INTO
WED...HOWEVER APPEARS ANY SNOW WILL BE ACROSS CNTRL AND WRN ND
WITH THE SFC HIGH MOVING ACROSS THE VALLEY. AN H500 SHORT WAVE
RIDGE THEN CONTINUES THE DRY WEATHER FROM WED TO THE END OF THE
WEEK...WITH RETURN FLOW SETTING UP TO BRING MUCH WELCOMED RELIEF
TO THE FRIGID AIRMASS. TEMPS IN THE TEENS ARE POSSIBLE BY
THURSDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1153 PM CST THU JAN 2 2014
SOME BLOWING SNOW HAS REDUCED VIS AND BROUGHT SOME LOWER CIGS
FROM THE RED RIVER VALLEY WESTWARD OVERNIGHT...THINK THAT THIS
WILL CONTINUE ON AND OFF INTO THE EARLY MORNING HOURS AS SOUTHERLY
WINDS CONTINUE TO BE BREEZY. THINK THAT CONDITIONS WILL GO IN AND
OUT OF MVFR TO VFR WITH SOME DROPS TO IFR...AND COVERED THIS WITH
TEMPO GROUPS. THE CENTER OF THE SFC LOW WILL MOVE INTO THE REGION
BY TOMORROW AFTERNOON...BRINGING SOME DECREASING SOUTHWESTERLY
WINDS FOR A WHILE BUT LIGHT SNOW AND POSSIBLY EVEN SOME FZRA IN
THE SOUTH WILL CONTINUE. THE COLD FRONT WILL DROP DOWN INTO THE
AREA FRIDAY EVENING...WITH STRONG NORTHWESTERLY WINDS AND BLOWING
SNOW REDUCING VIS DOWN TO A MILE OR POSSIBLY LESS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...BLIZZARD WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING FOR
NDZ024-026>030-038-039-049-052-053.
WIND CHILL ADVISORY UNTIL 6 AM CST FRIDAY FOR NDZ006>008-014>016-
024-026>030-038-039-049-052>054.
BLIZZARD WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY MORNING
FOR NDZ006>008-014>016-054.
MN...BLIZZARD WATCH FROM FRIDAY EVENING THROUGH SATURDAY MORNING FOR
MNZ001>003-027-029-030-040.
WIND CHILL ADVISORY UNTIL 6 AM CST FRIDAY FOR MNZ001>009-013>017-
022>024-027>032-040.
BLIZZARD WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY MORNING
FOR MNZ004-007.
&&
$$
UPDATE...JR
SHORT TERM...DK
LONG TERM...DK/SPEICHER
AVIATION...JR
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
928 PM CST SAT JAN 4 2014
.UPDATE...
...VERY COLD THE NEXT SEVERAL DAYS...
THE COLD FRONT CONTINUES TO MAKE GOOD PROGRESS TONIGHT MOVING
SOUTHEAST. AT 9 PM...IT WAS LOCATED GENERALLY ALONG AN EAST OF
SHERMAN TO FORT WORTH AND EASTLAND LINE WITH MUCH STRONGER
NORTHWEST WINDS LAGGING SEVERAL HOURS BEHIND THE INITIAL WIND
SHIFT. EXPECT TEMPERATURES TO DROP UP TO 10 DEGREES IN THE FIRST
HOUR BEHIND THE INITIAL WIND SHIFT...THEN CONTINUING TO DROP
THROUGHOUT THE REST OF THE NIGHT.
ONE CONCERN WITH THIS VERY COLD AIR MASS WILL BE THE WIND CHILLS
THAT WILL OCCUR SUNDAY MORNING...AND AGAIN SUNDAY NIGHT THROUGH
MONDAY MORNING. READINGS BELOW 10 DEGREES WILL BE LIKELY WEST
THROUGH NORTH OF THE METROPLEX SUNDAY MORNING AND GENERALLY ACROSS
ALL OF NORTH AND CENTRAL TEXAS FROM MIDNIGHT SUNDAY THROUGH MID
MORNING MONDAY. THOSE VENTURING OUT IN THESE CONDITIONS SHOULD
DRESS APPROPRIATELY AND LIMIT OUTSIDE EXPOSURE TIME.
IN OUR EVENING ANALYSIS OF MODEL DATA...WE/VE DECIDED TO LOWER
LOW TEMPS A DEGREE OR TWO ON MONDAY...LOWERED HIGHS ON MONDAY A
GOOD 3-4 DEGREES AND MADE MINOR ADJUSTMENTS TO THE LOWS ON TUESDAY
MORNING. HAVE ALSO MADE SOME HOURLY GRID ADJUSTMENTS TO BETTER
REFLECT FRONTAL TIMING AND TRENDS OF WINDS/TEMPS/DEWPOINTS BEHIND
THE FRONT. NEW FORECAST PACKAGE WILL BE OUT SHORTLY. 75
&&
.AVIATION...
/00Z TAFS/
MAIN CONCERNS CONTINUE TO BEING TIMING OF THE ARCTIC FRONT INTO
ALL THE TERMINALS...THE SUBSEQUENT POST-FRONTAL CIGS.
COLD FRONT NOW PUSHING THROUGH AN OKC-WICHITA FALLS-LUBBOCK LINE
WITH THE INITIAL SURGE RELATIVELY SHALLOW AND JUST 2-2.5 KFT PER
MODEL BUFR AND RUC SOUNDINGS...AND MOS GUIDANCE. THE TRENDS BY
MODELS HAS BEEN TO SLOW THE INITIAL SURGE...LIKELY DUE TO STRONG
HEIGHT FALLS ASSOCIATED WITH A SHORTWAVE DROPPING SOUTHEAST OVER
WESTERN HIGH PLAINS. DID SLOW THE FROPA A FEW HOURS...BUT NOTHING
TOWARD THE VERY SLOW NAM AS DENSE AIR MASSES LIKE THESE USUALLY
PICK UP SPEED AT NIGHTFALL IN THE WINTER...NOT SLOW DOWN DESPITE
AFOREMENTIONED HEIGHT FALLS.
DFW AIRPORTS: WILL HAVE FROPA AT ALLIANCE AROUND 04Z/10 PM...DFW/FTW
05Z/11 PM...AND LOVE FIELD/ARLINGTON 06Z/MIDNIGHT. SSW WINDS 10-15
MPH MAY BRIEFLY VEER WSW AND DIMINISH TO AROUND 10 KTS AROUND
03Z...BEFORE SHIFTING NW AROUND 15 KTS.
ONCE THE STRONG CAA CATCHES UP...PRESSURE GRADIENT AND FRONTAL
INVERSION DEPTH INCREASE WITH GUSTY NNW WINDS 18-23 KTS THROUGH
THE MORNING HOURS. MVFR CIGS TO PREVAIL ABOVE 020...THEN SLOWLY
RISE INTO VFR 030-040 BY MIDDAY AND SCATTER OUT WITH WIND SPEEDS
SLOWLY DROPPING BY EARLY TO MID AFTERNOON SUNDAY.
WACO: FROPA WITH NW WINDS 15 KTS AROUND 09Z/3 AM...THEN THE SAME
PROCESS WITH INCREASING AND GUSTY NNW WINDS 17-21 KTS WITH MVFR
CIGS ABOVE 020 INITIALLY...GOING VFR 030-040 BY MIDDAY...THEN
SCATTERING LATER ON SUNDAY AFTERNOON.
05/
&&
.PREV DISCUSSION... /ISSUED 458 PM CST SAT JAN 4 2014/
AN ARCTIC COLD FRONT WILL MOVE THROUGH ALL OF NORTH TEXAS TONIGHT
AND BRING SOME VERY ABRUPT CHANGES. THE PASSAGE OF THE FRONT WILL
TURN THE WIND TO THE NORTH/NORTHWEST AND INCREASE IT BETWEEN 15
AND 25 MPH ALONG WITH SOME GUSTS IN EXCESS OF 30 MPH. THE
STRONGEST WIND SPEEDS SHOULD LAG THE FRONT BY A FEW HOURS. SINCE
THE FRONT WILL MOVE THROUGH MOST LOCATIONS AFTER DARK...THE
COMBINATION OF NOCTURNAL COOLING AND COLD AIR ADVECTION WILL
RESULT IN QUICKLY FALLING TEMPERATURES BEHIND THE FRONT. OVERNIGHT
LOW TEMPERATURES WILL FALL BELOW FREEZING IN MOST LOCATIONS WITH
WIND CHILL READINGS IN THE SINGLE DIGITS AND TEENS ACROSS THE
NORTHWEST HALF OF THE REGION. THERE IS A SLIGHT CHANCE OF RAIN
ACROSS THE EASTERN ZONES TONIGHT NEAR AND BEHIND THE FRONT. SINCE
MOISTURE WILL BE LIMITED...ANY RAIN THAT FALLS SHOULD BE VERY
LIGHT. HOWEVER...SOME LOCATIONS THAT SEE LIGHT RAIN WILL FALL
BELOW FREEZING BEFORE SUNRISE. THEREFORE...BRIEF...LIGHT FREEZING
RAIN WILL BE POSSIBLE. IF ANY FREEZING RAIN DOES OCCUR IN THE
EASTERN ZONES...IMPACTS SHOULD BE MINIMAL SINCE PRECIP WILL BE
VERY LIGHT. ALL PRECIP SHOULD MOVE EAST OF NORTH TEXAS AFTER
SUNRISE SUNDAY AS THE UPPER TROUGH AXIS EXITS THE REGION.
EVEN THOUGH THE SUN WILL RETURN ON SUNDAY...IT WILL BE A COLD AND
BLUSTERY DAY WITH HIGH TEMPERATURES ONLY REACHING THE 30S TO LOWER
40S AND A NORTH TO NORTHWEST WIND BETWEEN 15 AND 25 MPH ALONG WITH
SOME HIGHER GUSTS. SURFACE HIGH PRESSURE WILL SETTLE OVER THE
STATE SUNDAY NIGHT THROUGH MONDAY AND RESULT IN DECREASING WIND
SPEEDS AND A MOSTLY CLEAR SKY. SINCE THE WIND WILL NOT BECOME CALM
SUNDAY NIGHT...RADIATIONAL COOLING WILL NOT BE OPTIMAL.
HOWEVER...OVERNIGHT LOWS SUNDAY SHOULD STILL FALL INTO THE TEENS
AND 20S WITH WIND CHILL READINGS GENERALLY IN THE SINGLE DIGITS.
MONDAY AND MONDAY NIGHT WILL ALSO BE COLD WITH HIGHS GENERALLY IN
THE 30S AND LOWS IN THE TEENS TO AROUND 20. THE ONLY SAVING GRACE
WILL BE A RELATIVELY LIGHT WIND.
A WARM UP WILL BEGIN ON TUESDAY AS SOUTHERLY WINDS RETURN IN
RESPONSE TO A DEVELOPING HIGH PLAINS SURFACE TROUGH. LOW LEVEL
MOISTURE WILL SURGE NORTHWARD TUESDAY NIGHT THROUGH WEDNESDAY AS
THE SURFACE TROUGH DEEPENS INTO THE SOUTHERN HIGH PLAINS. RAIN
CHANCES WILL BEGIN WEDNESDAY MORNING AS LARGE SCALE LIFT INCREASES
WITH THE APPROACH OF A SHORT WAVE TROUGH. THE BEST RAIN CHANCES
WILL BE ACROSS THE EASTERN ZONES WEDNESDAY NIGHT THROUGH THURSDAY
WHEN A WEAK COLD FRONT ENTERS THE REGION.
RAIN CHANCES SHOULD CONTINUE ACROSS NORTH TEXAS THURSDAY NIGHT
THROUGH FRIDAY AS AN UPPER TROUGH MOVES ACROSS THE STATE. THE
ECMWF AND GFS SOLUTIONS ARE STILL NOT IN AGREEMENT ON THE
STRENGTH OF THIS SYSTEM. FOR NOW...WE WILL SIDE WITH THE MORE
PROGRESSIVE GFS SOLUTION AND MOVE THE TROUGH AXIS THROUGH NORTH
TEXAS SATURDAY. HOWEVER...IF THE ECMWF SOLUTION VERIFIES IT WOULD
RESULT IN AN EXTENDED PERIOD OF RAIN THROUGH SUNDAY OF NEXT WEEK.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 28 37 17 30 21 / 10 10 0 0 0
WACO, TX 32 45 19 36 15 / 10 10 0 0 0
PARIS, TX 27 35 12 26 13 / 20 10 5 0 0
DENTON, TX 24 35 14 29 16 / 10 10 0 0 0
MCKINNEY, TX 27 35 14 27 16 / 10 10 0 0 0
DALLAS, TX 28 37 17 30 20 / 10 10 0 0 0
TERRELL, TX 29 37 15 30 16 / 20 10 0 0 0
CORSICANA, TX 32 39 19 32 18 / 10 10 5 0 0
TEMPLE, TX 31 43 19 37 16 / 5 10 0 0 0
MINERAL WELLS, TX 21 37 14 31 16 / 5 10 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
/75
AREA FORECAST DISCUSSION...UPDATED
NWS FORT WORTH TX
551 PM CST SAT JAN 4 2014
.AVIATION...
/00Z TAFS/
MAIN CONCERNS CONTINUE TO BEING TIMING OF THE ARCTIC FRONT INTO
ALL THE TERMINALS...THE SUBSEQUENT POST-FRONTAL CIGS.
COLD FRONT NOW PUSHING THROUGH AN OKC-WICHITA FALLS-LUBBOCK LINE
WITH THE INITIAL SURGE RELATIVELY SHALLOW AND JUST 2-2.5 KFT PER
MODEL BUFR AND RUC SOUNDINGS...AND MOS GUIDANCES. THE TRENDS BY
MODELS HAS BEEN TO SLOW THE INITIAL SURGE...LIKELY DUE TO STRONG
HEIGHT FALLS ASSOCIATED WITH A SHORTWAVE DROPPING SOUTHEAST OVER
WESTERN HIGH PLAINS. DID SLOW THE FROPA A FEW HOURS...BUT NOTHING
TOWARD THE VERY SLOW NAM AS DENSE AIRMASSES LIKE THESE USUALLY
PICK UP SPEED AT NIGHTFALL IN THE WINTER...NOT SLOW DOWN DESPITE
AFOREMENTIONED HEIGHT FALLS.
DFW AIRPORTS: WILL HAVE FROPA AT ALLIANCE AROUND 04Z/10 PM...DFW/FTW
05Z/11 PM...AND LOVE FIELD/ARLINGTON 06Z/MIDNIGHT. SSW WINDS 10-15
MPH MAY BRIEFLY VEER WSW AND DIMINISH TO AROUND 10 KTS AROUND
03Z...BEFORE SHIFTING NW AROUND 15 KTS.
ONCE THE STRONG CAA CATCHES UP...PRESSURE GRADIENT AND FRONTAL
INVERSION DEPTH INCREASE WITH GUSTY NNW WINDS 18-23 KTS THROUGH
THE MORNING HOURS. MVFR CIGS TO PREVAIL ABOVE 020...THEN SLOWLY
RISE INTO VFR 030-040 BY MIDDAY AND SCATTER OUT WITH WIND SPEEDS
SLOWLY DROPPING BY EARLY TO MID AFTERNOON SUNDAY.
WACO: FROPA WITH NW WINDS 15 KTS AROUND 09Z/3 AM...THEN THE SAME
PROCESS WITH INCREASING AND GUSTY NNW WINDS 17-21 KTS WITH MVFR
CIGS ABOVE 020 INITIALLY...GOING VFR 030-040 BY MIDDAY...THEN
SCATTERING LATER ON SUNDAY AFTERNOON.
05/
&&
.PREV DISCUSSION... /ISSUED 458 PM CST SAT JAN 4 2014/
AN ARCTIC COLD FRONT WILL MOVE THROUGH ALL OF NORTH TEXAS TONIGHT
AND BRING SOME VERY ABRUPT CHANGES. THE PASSAGE OF THE FRONT WILL
TURN THE WIND TO THE NORTH/NORTHWEST AND INCREASE IT BETWEEN 15
AND 25 MPH ALONG WITH SOME GUSTS IN EXCESS OF 30 MPH. THE
STRONGEST WIND SPEEDS SHOULD LAG THE FRONT BY A FEW HOURS. SINCE
THE FRONT WILL MOVE THROUGH MOST LOCATIONS AFTER DARK...THE
COMBINATION OF NOCTURNAL COOLING AND COLD AIR ADVECTION WILL
RESULT IN QUICKLY FALLING TEMPERATURES BEHIND THE FRONT. OVERNIGHT
LOW TEMPERATURES WILL FALL BELOW FREEZING IN MOST LOCATIONS WITH
WIND CHILL READINGS IN THE SINGLE DIGITS AND TEENS ACROSS THE
NORTHWEST HALF OF THE REGION. THERE IS A SLIGHT CHANCE OF RAIN
ACROSS THE EASTERN ZONES TONIGHT NEAR AND BEHIND THE FRONT. SINCE
MOISTURE WILL BE LIMITED...ANY RAIN THAT FALLS SHOULD BE VERY
LIGHT. HOWEVER...SOME LOCATIONS THAT SEE LIGHT RAIN WILL FALL
BELOW FREEZING BEFORE SUNRISE. THEREFORE...BRIEF...LIGHT FREEZING
RAIN WILL BE POSSIBLE. IF ANY FREEZING RAIN DOES OCCUR IN THE
EASTERN ZONES...IMPACTS SHOULD BE MINIMAL SINCE PRECIP WILL BE
VERY LIGHT. ALL PRECIP SHOULD MOVE EAST OF NORTH TEXAS AFTER
SUNRISE SUNDAY AS THE UPPER TROUGH AXIS EXITS THE REGION.
EVEN THOUGH THE SUN WILL RETURN ON SUNDAY...IT WILL BE A COLD AND
BLUSTERY DAY WITH HIGH TEMPERATURES ONLY REACHING THE 30S TO LOWER
40S AND A NORTH TO NORTHWEST WIND BETWEEN 15 AND 25 MPH ALONG WITH
SOME HIGHER GUSTS. SURFACE HIGH PRESSURE WILL SETTLE OVER THE
STATE SUNDAY NIGHT THROUGH MONDAY AND RESULT IN DECREASING WIND
SPEEDS AND A MOSTLY CLEAR SKY. SINCE THE WIND WILL NOT BECOME CALM
SUNDAY NIGHT...RADIATIONAL COOLING WILL NOT BE OPTIMAL.
HOWEVER...OVERNIGHT LOWS SUNDAY SHOULD STILL FALL INTO THE TEENS
AND 20S WITH WIND CHILL READINGS GENERALLY IN THE SINGLE DIGITS.
MONDAY AND MONDAY NIGHT WILL ALSO BE COLD WITH HIGHS GENERALLY IN
THE 30S AND LOWS IN THE TEENS TO AROUND 20. THE ONLY SAVING GRACE
WILL BE A RELATIVELY LIGHT WIND.
A WARM UP WILL BEGIN ON TUESDAY AS SOUTHERLY WINDS RETURN IN
RESPONSE TO A DEVELOPING HIGH PLAINS SURFACE TROUGH. LOW LEVEL
MOISTURE WILL SURGE NORTHWARD TUESDAY NIGHT THROUGH WEDNESDAY AS
THE SURFACE TROUGH DEEPENS INTO THE SOUTHERN HIGH PLAINS. RAIN
CHANCES WILL BEGIN WEDNESDAY MORNING AS LARGE SCALE LIFT INCREASES
WITH THE APPROACH OF A SHORT WAVE TROUGH. THE BEST RAIN CHANCES
WILL BE ACROSS THE EASTERN ZONES WEDNESDAY NIGHT THROUGH THURSDAY
WHEN A WEAK COLD FRONT ENTERS THE REGION.
RAIN CHANCES SHOULD CONTINUE ACROSS NORTH TEXAS THURSDAY NIGHT
THROUGH FRIDAY AS AN UPPER TROUGH MOVES ACROSS THE STATE. THE
ECMWF AND GFS SOLUTIONS ARE STILL NOT IN AGREEMENT ON THE
STRENGTH OF THIS SYSTEM. FOR NOW...WE WILL SIDE WITH THE MORE
PROGRESSIVE GFS SOLUTION AND MOVE THE TROUGH AXIS THROUGH NORTH
TEXAS SATURDAY. HOWEVER...IF THE ECMWF SOLUTION VERIFIES IT WOULD
RESULT IN AN EXTENDED PERIOD OF RAIN THROUGH SUNDAY OF NEXT WEEK.
79
&&
.PRELIMINARY POINT TEMPS/POPS...
DALLAS-FT. WORTH, TX 28 37 18 33 21 / 10 10 0 0 0
WACO, TX 32 45 21 39 15 / 10 10 0 0 0
PARIS, TX 27 35 13 29 13 / 20 10 5 0 0
DENTON, TX 24 35 17 28 15 / 10 10 0 0 0
MCKINNEY, TX 27 35 15 29 16 / 10 10 0 0 0
DALLAS, TX 28 37 18 32 20 / 10 10 0 0 0
TERRELL, TX 29 37 16 32 16 / 20 10 0 0 0
CORSICANA, TX 32 39 20 36 18 / 10 10 5 0 0
TEMPLE, TX 31 43 20 39 16 / 5 10 0 0 0
MINERAL WELLS, TX 21 37 15 33 16 / 5 10 0 0 0
&&
.FWD WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
05/79
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
926 PM CST SAT JAN 4 2014
.UPDATE...
NO SURPRISES IN THE 00Z NAM. THEY CONFIRM THE 6 HOUR SLOWER
ARRIVAL OF WIND CHILLS REACHING ADVISORY CRITERIA. BESIDES THAT
THE NAM TEMPS AND NAM MOS HAVE VIRTUALLY THE SAME BITTER COLD
TEMPERATURES SUNDAY NIGHT THROUGH MONDAY. THEREFORE THE WIND CHILL
WARNINGS REMAIN WITH THE SAME WIND CHILL VALUES.
THE 00Z NAM STILL CLIPS THE KENOSHA AREA WITH 3 TO 5 INCH SNOW
POTENTIAL LATE TONIGHT THROUGH SUNDAY. WILL BE A CLOSE CALL ON THE
NORTH FRINGE OF THE PRECIPITATION SHEILD. AMOUNTS RAPIDLY
DECREASE TO THE NORTH WITH UP TO AN INCH POSSIBLE IN THE FAR
SOUTHEAST CORNER OF MILWAUKEE COUNTY.
&&
.AVIATION/06Z TAFS/...
THE SNOW HAS TEMPORARILY SAGGED SOUTH OF THE KENOSHA AREA.
THE 00Z NAM STILL CLIPS THE KENOSHA AREA WITH 3 TO 5 INCH SNOW
POTENTIAL LATE TONIGHT THROUGH SUNDAY. WILL BE A CLOSE CALL ON THE
NORTH FRINGE OF THE PRECIPITATION SHEILD. AMOUNTS RAPIDLY
DECREASE TO THE NORTH WITH UP TO AN INCH POSSIBLE IN THE FAR
SOUTHEAST CORNER OF MILWAUKEE COUNTY.
THEREFORE IFR VSBYS AGAIN EXPECTED IN THE FAR SOUTHEAST.
OTHERWISE MVFR CIGS IN THE SOUTHEAST WITH VFR FARTHER NORTH AND
WEST.
NORTHWEST WINDS WILL INCREASE SUNDAY AS BITTER COLD AIR MOVES IN
BY SUNDAY NIGHT AND CONTINUING INTO TUESDAY.
&&
.PREV DISCUSSION... /ISSUED 331 PM CST SAT JAN 4 2014/
TONIGHT AND SUNDAY...FORECAST CONFIDENCE IS HIGH.
WINTER WEATHER ADVISORY FOR WALWORTH...RACINE AND KENOSHA
COUNTIES CONTINUES UNTIL 00Z MONDAY. AREA RADARS SHOWING MORE
BANDS OF LIGHT TO MODERATE SNOW DEVELOPING FROM FAR EASTERN
IOWA...THROUGH NORTHEAST ILLINOIS/FAR SOUTHEAST WISCONSIN...INTO
SOUTHWEST LOWER MICHIGAN.
THIS WAS BEING DRIVEN BY RIGHT ENTRANCE REGION OF 300 MB JET
STREAK...AS WELL AS MODEST LOW TO MID LEVEL FRONTOGENESIS
RESPONSE. THE MID LEVEL FRONTOGENESIS LINGERS ACROSS THE FAR
SOUTHEAST INTO SUNDAY AFTERNOON...WITH 850MB TROUGH/CONVERGENCE
AND LOW LEVEL FRONTOGENESIS RESPONSE ALSO LINGERING INTO TONIGHT.
GOOD UPWARD VERTICAL MOTION SHOWN IN SATURATED AIR COLUMN AND
DENDRITE ZONE ACROSS THE FAR SOUTHEAST COUNTIES THROUGH TONIGHT
AND SUNDAY ON THE NAM. NAM/CANADIAN/ECMWF HAVE QPF LINGERING IN
THE SOUTHEAST THROUGH SUNDAY.
HOWEVER...GFS DRIES OUT LOW AND SOME OF THE MID LEVELS TONIGHT
INTO SUNDAY. THIS RESULTS IN A MAINLY DRY SUNDAY IN THE FAR
SOUTHEAST. HRRR TRYING TO SHOW A PERIOD OF DRY CONDITIONS LATER
THIS EVENING INTO THE OVERNIGHT HOURS BEFORE BRINGING THE SNOW
BACK BY 09Z SUNDAY.
NAM/MESOSCALE MODELS/SOME SREF ENSEMBLES ARE CRANKING OUT QUITE A
BIT OF QPF IN THE FAR SOUTHEAST THROUGH SUNDAY...UP TO AROUND 1/2
INCH IN SOME INSTANCES. FOR NOW...LEANED TOWARD THE WETTER
SOLUTIONS...BUT DID NOT GO QUITE AS HIGH AS THEM WITH QPF AND
SUBSEQUENT SNOW AMOUNTS.
EXPECTING A 3 TO 5 INCH ACCUMULATION NEAR THE BORDER IN KENOSHA
COUNTY THROUGH SUNDAY...TO AROUND AN INCH IN A MILWAUKEE TO BELOIT
LINE...LOWER TO THE NORTH AND WEST. THESE AMOUNTS COULD BE
SOMEWHAT HIGHER IF THE AFOREMENTIONED WETTER LOOKING MODELS
VERIFY...SO INCREASING AMOUNTS AND ADJUSTING HEADLINES ARE
POSSIBLE IN LATER FORECASTS.
STRONG COLD AIR ADVECTION WILL DEVELOP TONIGHT INTO SUNDAY...AS
ARCTIC AIRMASS MOVES INTO THE AREA. WIND CHILLS ARE EXPECTED TO
DROP QUICKLY AWAY IN SOUTH CENTRAL WISCONSIN LATER TONIGHT...AND
ACROSS AREAS AWAY FROM THE LAKE SUNDAY. KEPT WIND CHILL ADVISORIES
GOING FROM PREVIOUS FORECAST. TEMPERATURES WILL DROP QUICKLY
TONIGHT...AND WILL REMAIN NEARLY STEADY SUNDAY WITH COLD AIR
ADVECTION CONTINUING.
SUNDAY NIGHT THROUGH TUESDAY...FORECAST CONFIDENCE HIGH.
THE FORECAST OF DANGEROUSLY COLD AIR FOR THIS PERIOD REMAINS ON
TRACK. STRONG LOW PRESSURE THAT WILL MOVE UP THE OHIO VALLEY
TONIGHT AND SUNDAY WILL INTENSIFY FURTHER AND LIKELY RETROGRADE A
BIT FARTHER WEST SUNDAY NIGHT INTO MONDAY. THIS MAY ALLOW US TO
ADJUST TEMPS UP A DEGREE OR SO...BUT THE WINDS WILL BE
STRONGER...SO NO NET GAIN ON THOSE BRUTAL WIND CHILL READINGS.
SOME OF THE MODELS SUGGEST THE CHANCE FOR SNOW MAY HANG BACK
ACROSS THE FAR EAST INTO SUNDAY NIGHT DUE TO THE RETROGRADE TRACK
OF THE LOW. I/LL KEEP A VERY SMALL CHANCE IN THE EAST JUST IN
CASE...BUT IT WILL BE MINOR STUFF EITHER WAY.
WEDNESDAY THROUGH THURSDAY...FORECAST CONFIDNECE IS MEDIUM.
WE START TO SEE A SHIFT TOWARD A WARMER PATTERN BY MID WEEK. TEMPS
TUESDAY NIGHT/WEDNESDAY MORNING WILL STILL BE VERY COLD ABOUT -5
TO -10...COLD BUT A DECENT IMPROVEMENT FROM THE PREVIOUS COUPLE
OF DAYS. A WARM FRONT APPROACHES FROM THE SOUTH AND THIS COUPLED
WITH THE ARRIVAL OF A FAVORABLE ENTRANCE REGION OF AN UPPER JET
SHOULD TRIGGER SOME FRONTOGENESIS AND WARM ADVECTION ACROSS THE
FRONT. ISENTROPICALLY WE START TO SEE SOME DECENT SATURATION AND
ALL THIS COULD RESULT IN SOME LIGHT SNOW WED AND WED NGT WITH ONLY
A SMALL CHANCE LINGERING INTO THURSDAY.
FRIDAY AND SATURDAY...FORECAST CONFIDENCE IS MEDIUM.
TEMPS ARE EXPECTED TO CLIMB TO NEAR OR SLIGHTLY ABOVE NORMAL BY
THE END OF NEXT WEEK. HIGHS ARE EXPECTED TO CLIMB INTO THE LOWER
TO MID 30S. THIS COMES AS HIGH PRESSURE SLIPS OFF TO THE EAST AND
LOW PRESSURE MOVES ACROSS THE NORTHERN TIER OF THE U.S.
AVIATION/00Z TAFS/...
EXPECT LIGHT TO MODERATE SNOW TO CONTINUE AT THE EASTERN SITES
TONIGHT AND SUNDAY...WITH MADISON WEST OF THE SNOW.
KENOSHA SHOULD SEE VISIBILITIES DOWN TO AIRFIELD MINIMUMS AT
TIMES FOR MOST OF TONIGHT...AND AROUND OR BELOW ALTERNATE MINIMUMS
LATER TONIGHT AND SUNDAY. SNOWFALL RATES OF 1/4 INCH PER HOUR ARE
EXPECTED TONIGHT...WITH SOME 1/2 INCH PER HOUR RATES POSSIBLE.
TOTAL OF 3 TO 5 INCHES ARE POSSIBLE BY LATE SUNDAY HERE.
MILWAUKEE AND WAUKESHA MAY SEE A BREAK IN THE SNOW THIS EVENING
AND INTO THE OVERNIGHT HOURS...BEFORE IT OCCURS AGAIN LATER
TONIGHT INTO SUNDAY. FOR NOW...KEPT SNOW IN TAFS AS AM DOUBTFUL
THIS WILL OCCUR. RATES WILL BE 1/4 INCH PER HOUR WHEN THE SNOW
FALLS...WITH BRIEF 1/2 INCH PER HOUR RATES POSSIBLE. TOTAL AMOUNTS
OF AROUND AN INCH ARE EXPECTED BY LATE SUNDAY. MADISON SHOULD BE
JUST WEST OF THE SNOW AREA...AND SHOULD NOT SEE ANY ACCUMULATIONS.
SOUTHWEST WINDS WILL SHIFT NORTHWEST EARLY THIS EVENING IN THE
EASTERN SITES...AS COLD FRONT SLIDES SOUTHEAST THROUGH THE AREA.
WINDS WILL BECOME GUSTY BY SUNDAY AFTERNOON. MAY SEE SOME BLOWING
SNOW OCCUR AT THE EASTERN SITES SUNDAY AFTERNOON...BUT
VISIBILITIES SHOULD BE ABOVE 3 MILES.
MARINE...
SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR SUNDAY...WITH A GALE
WATCH FOR SUNDAY NIGHT THROUGH MONDAY NIGHT...AS A TIGHT PRESSURE
GRADIENT DEVELOPS WITH STRENGTHENING LOW PRESSURE PASSING
SOUTHEAST OF THE REGION. GUSTS MAY REACH GALE FORCE AT TIMES
SUNDAY NIGHT THROUGH MONDAY NIGHT. HIGH WAVES WILL BE LIMITED
TOWARD AND OVER THE OPEN WATERS...IN THE ICE FREE AREAS. GUSTY
WINDS MAY LINGER THROUGH TUESDAY NIGHT...UNTIL STRONG LOW PRESSURE
MOVES AWAY FROM THE REGION.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL WARNING FROM 6 PM SUNDAY TO NOON CST TUESDAY FOR
WIZ046-047-051-052-056>060-062>072.
WIND CHILL ADVISORY FROM NOON TO 6 PM CST SUNDAY FOR WIZ051-058-
063-064-067>069.
WIND CHILL ADVISORY FROM 6 AM TO 6 PM CST SUNDAY FOR WIZ046-047-
056-057-062.
WINTER WEATHER ADVISORY UNTIL 6 PM CST SUNDAY FOR WIZ070>072.
LM...SMALL CRAFT ADVISORY FROM 6 AM TO 6 PM CST SUNDAY FOR LMZ643>646.
GALE WARNING FROM 6 PM SUNDAY TO 4 AM CST TUESDAY FOR LMZ643>646.
&&
$$
UPDATE...HENTZ
TONIGHT/SUNDAY AND AVIATION/MARINE...WOOD
SUNDAY NIGHT THROUGH SATURDAY...DAVIS
AREA FORECAST DISCUSSION...UPDATED
NWS GREEN BAY WI
851 PM CST SAT JAN 4 2014
NEW INFORMATION ADDED TO UPDATE SECTION
.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 00Z TAF ISSUANCE
ISSUED AT 511 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. EXPECT INCREASING
WINDS TOMORROW AFTN AS WAVE RIDES NEWD ALONG THE ARCTIC FRONT TO
OUR E.
&&
.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 FROM MIDNIGHT TONIGHT TO 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 GREEN BAY WI
704 PM CST SAT JAN 4 2014
NEW INFORMATION ADDED TO UPDATE SECTION
.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 00Z TAF ISSUANCE
ISSUED AT 511 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. EXPECT INCREASING
WINDS TOMORROW AFTN AS WAVE RIDES NEWD ALONG THE ARCTIC FRONT TO
OUR E.
&&
.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 FROM MIDNIGHT TONIGHT TO 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 GREEN BAY WI
517 PM CST SAT JAN 4 2014
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.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 00Z TAF ISSUANCE
ISSUED AT 511 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. EXPECT INCREASING
WINDS TOMORROW AFTN AS WAVE RIDES NEWD ALONG THE ARCTIC FRONT TO
OUR E.
&&
.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 MIDNIGHT TONIGHT TO 6 PM CST SUNDAY FOR
WIZ013-020-021-031-037>039-045-048-049-073-074.
WIND CHILL ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST SUNDAY
FOR WIZ005-010>012-018-019-030-035-036.
&&
$$
SHORT TERM.....MPC
LONG TERM......TDH
AVIATION.......SKOWRONSKI
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
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...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 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 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
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 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 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
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 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...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:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
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 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 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 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 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
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 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
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