Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/13/13
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
835 PM MST THU DEC 12 2013
.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL CONTINUE TO MOVE WEST TO EAST ACROSS
THE REGION THROUGH EARLY TONIGHT...RESULTING IN A SLIGHT CHANCE OF
SHOWERS AND THUNDERSTORMS. OTHERWISE DRY WEATHER WITH ABOVE NORMAL
TEMPERATURES DEVELOP FRIDAY THROUGH EARLY NEXT WEEK.
&&
.DISCUSSION...
THE UPPER LOW THAT BROUGHT SPOTTY SHOWER ACTIVITY EARLIER TODAY TO
PARTS OF SOUTHEAST CA...WITH LOST HORSE RAWS IN JOSHUA TREE NATIONAL
PARK REPORTING 0.06 OF AN INCH OF RAIN...HAS NOW MOVED INTO
SOUTHWEST ARIZONA. ALTHOUGH THIS LOW CENTER IS STILL EXPECTED TO
PASS OVER CENTRAL ARIZONA LATER TONIGHT...AND INTO WESTERN NEW
MEXICO BY EARLY FRIDAY MORNING...MOISTURE AND SHOWERS ASSOCIATED
WITH THIS LOW CENTER HAS NOW SHIFTED WELL TO OUR NORTH AND
EAST...PRESENTLY LOCATED IN AN ARC FROM KINGMAN...TO
FLAGSTAFF...ACROSS THE WHITE MOUNTAINS...THEN INTO EXTREME SOUTHWEST
NM...WITH A PUSH OF DRIER AIR FROM THE SOUTHWEST KEEPING
SOUTH-CENTRAL ARIZONA COMPLETELY DRY...WITH JUST SCATTERED MID-LEVEL
CLOUDINESS BEING REPORTED THIS AFTERNOON AND EVENING. THIS IS WHAT
LED TO THE UPDATED FORECAST EARLIER THIS EVENING THAT PRETTY MUCH
REMOVED ANY CHANCES FOR SHOWERS ACROSS THE GREATER PHOENIX AREA.
ALTHOUGH THERE IS STILL A CHANCE FOR A FEW SHOWERS ACROSS THE HIGHER
ELEVATIONS OF SOUTHERN GILA COUNTY THROUGH LATE TONIGHT...LATEST NAM
AND HRRR MODEL OUTPUT HAS NOW COME INTO AGREEMENT THAT MOST AREAS
WILL REMAIN DRY THROUGH TONIGHT...AND ON INTO AT LEAST THE MIDDLE
PART OF NEXT WEEK. THUS...NO FURTHER UPDATES TO EITHER THE
SHORT-TERM GRIDS OR ZONE FORECASTS ARE PLANNED AT THIS TIME.
&&
.PREVIOUS DISCUSSION...
TONIGHT...
A CUTOFF LOW...CENTERED NEAR YUMA AT 22Z...CONTINUED TO CIRCULATE
ACROSS THE REGION THIS AFTERNOON. MARGINAL MOISTURE AMOUNTS
ACCOMPANYING THE UPPER LOW HAVE RESULTED IN ISOLATED SHOWERS AND
THUNDERSTORMS...MAINLY ACROSS SOUTHEAST CA AND SOUTHWEST AZ THIS
AFTERNOON. ALL MODELS POINT TO THE CUTOFF LOW MOVING QUICKLY EAST
THIS EVENING AND PROVIDING UPPER LEVEL SUPPORT FOR A THREAT OF
SHOWERS AND THUNDERSTORMS OVER SOUTH CENTRAL AZ...INCLUDING PHOENIX
BY THIS EVENING. A CHANCE OF SHOWERS WILL CONTINUE THROUGH LATE
NIGHT OVER SOUTHERN GILA COUNTY ZONE 24...OTHERWISE CLEARING SKIES
WILL SPREAD WEST TO EAST TONIGHT.
FRIDAY...
A SECOND BY DRIER DISTURBANCE WILL MOVE INTO AZ FRIDAY RESULTING IN
CLEAR SKIES AND COOLER TEMPERATURES.
SATURDAY THROUGH THURSDAY...
HIGH PRESSURE WILL REBUILD OVER THE REGION PROVIDING MOSTLY CLEAR
SKIES AND WARMER TEMPERATURES. SOME COOLING MAY TAKE PLACE NEXT
THURSDAY AS MODELS FORECAST ANOTHER DRY WEATHER DISTURBANCE TO MOVE
INTO THE REGION LATER NEXT WEEK.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA...INCLUDING KPHX...KIWA...AND KSDL...
UPPER-LEVEL DISTURBANCE THAT IS NOW MOVING INTO WESTERN ARIZONA IS
EXPECTED TO KEEP SCT-BKN MID-LEVEL CLOUDS OVER THE PHX AREA
TERMINALS THROUGH THIS EVENING...WITH GRADUAL CLEARING EXPECTED
LATER TONIGHT. THERE IS STILL A SLIGHT CHANCE THAT SHOWERS MAY
IMPACT THE TERMINALS EARLY THIS EVENING...BUT CONFIDENCE IS TOO LOW
TO EVEN INCLUDE VCSH IN THE TAFS AT THIS TIME. WESTERLY WINDS EARLY
THIS EVENING TO BECOME TYPICAL DIURNAL EASTERLY WINDS LATER
TONIGHT...WITH LIGHT WESTERLY WINDS REDEVELOPING ON FRIDAY AFTERNOON.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA...INCLUDING KIPL AND
KBLH...
LINGERING MID-LEVEL CLOUDS ARE EXPECTED TO CLEAR LATER THIS EVENING
AS THE UPPER-LEVEL DISTURBANCE THAT BROUGHT THESE CLOUDS MOVES OFF
TO THE EAST. WINDS TO REVERT TO NORMAL DIURNAL DIRECTIONS LATER
TONIGHT AND ON FRIDAY...WITH SPEEDS MAINLY AOB 10KTS.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
DRY CONDITIONS WILL PERSIST THROUGH THE WEEKEND AND INTO NEXT WEEK
AS HIGH PRESSURE BECOMES REESTABLISHED ACROSS THE EASTERN PACIFIC
AND THE INTERMOUNTAIN WEST. ABOVE NORMAL TEMPERATURES AND BELOW
MEDIAN PRECIPITATION ARE EXPECTED.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...NONE.
CA...NONE.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/VASQUEZ
AVIATION...PERCHA
FIRE WEATHER...HIRSCH
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
304 AM CST WED DEC 11 2013
.DISCUSSION...
920 PM CST
THE CURRENT WINTER WEATHER ADVISORY FOR OVERNIGHT AND WEDNESDAY
MORNING CONTINUES AS IS WITH NO MAJOR CHANGES TO GOING FORECAST
SNOWFALL TIMING OR TOTAL AMOUNTS. HAVE ADDED PATCHY BLOWING SNOW
IN FOR THE MORNING IN THE FAR WEST AND SPREAD IT EASTWARD DURING
THE AFTERNOON AS THE COLD...OR SHOULD WE SAY COLDER...AIR SURGES
BACK IN.
THE POSITIVES TOWARD SNOWFALL WITH THIS SYSTEM REMAIN IN
OBSERVATIONAL AND SHORT TERM GUIDANCE...WITH HIGHER SNOW-TO-
LIQUID RATIOS AND TEMPORARY MODEST RATES...WHILE THE SUBTLE
CAVEATS OF A SOMEWHAT WEAK WAVE AND LOW COLUMN MOISTURE ARE LIKELY
TO BE OFFSET BY THESE ENOUGH TO PRODUCE 2-3.5" SNOWFALL AMOUNTS
AND LIKELY SCATTERED HIGHER AMOUNTS WITHIN THE ADVISORY AREA.
RADAR ECHOES ARE ON THE UPWARD TREND ACROSS CENTRAL IA WITHIN THE
WARM AIR ADVECTION WING OF THE SHORT WAVE SEEN ON WATER VAPOR
PROGRESSING EAST SOUTHEAST. THIS WAVE WILL TURN MORE EAST ALONG A
WELL-DEFINED 850-600MB BAROCLINIC ZONE SEEN ON THIS EVES UPPER
AIR DATA. HAVE ALREADY NOTED 3/4SM VISIBILITY IN IA...LIKELY
ASSOCIATED WITH ONE HALF TO ONE INCH PER HOUR TYPE RATES. WITH
CLIPPER SYSTEMS IT SEEMS THAT THE LOWEST VISIBILITY CAN OFTEN BE
EXTRAPOLATED OUT ALONG THE PATH GIVEN THE WAVE MAINTAINS ITS
INTENSITY. THE RAP CONTINUES TO SHOW A FAIRLY QUICK PROGRESSION
OF THE LEADING EDGE OF SNOW OVER MUCH OF THE FORECAST AREA BETWEEN
12AM-3AM...SO DID NOT GET FANCY WITH TRYING TO ADJUST THE ADVISORY
START TIME. TEMPORARY WEST-TO-EAST BANDED SNOW OVERNIGHT WOULD
SEEM PROBABLE IN NORTH CENTRAL IL...MAYBE INTO THE CHICAGO
METRO...ALONG THE BAROCLINIC ZONE AND FAIRLY WELL-DEFINED
MOISTURE CONVERGENCE. CONVECTIVE ALLOWING/HIGH RES GUIDANCE
INDICATES HIGHER REFLECTIVITY AS WELL IN THE 3-8 AM PERIOD. SNOW
LOOKS TO LINGER OVER CHICAGO THROUGH THE END OF THE ADVISORY TIME.
FORECAST SOUNDINGS CONTINUE TO INDICATE A VERY DEEP DENDRITIC
GROWTH AREA WITH NOT OVERLY HIGH WINDS BELOW THE CLOUD BASE FOR
FRAGMENTING. EVEN THE 00Z DVN SOUNDING HAD THE WET BULB
TEMPERATURE BASICALLY WITHIN THE DENDRITIC GROWTH AREA ALL THE WAY
TO ~10000 FT! THIS SHOULD ALLOW FOR GOOD EFFICIENCY (20:1) OF
MEAGER PWAT VALUES UNDER 0.2 INCH AND MIXING RATIOS IN THE CLOUD
LAYER OF 1-1.5 G/KG. SO WE CONTINUE A LITTLE HIGHER THAT MOST
GUIDANCE FOR SNOWFALL AMOUNTS.
THE MOST PROBABLE TIMING FOR HEAVIEST SNOWFALL RATES IN ROCKFORD
IS 2-6 AM AND CHICAGO IS 4-8 AM. TEMPERATURES SHOULD CONTINUE TO
INCH UP PRIOR TO THE SNOWFALL...AND THEN HOLD STEADY IN THE MID-
UPPER TEENS DURING THE SNOW.
MTF
//PREV DISCUSSION...
250 PM...FORECAST CONCERNS INCLUDE ACCUMULATING SNOW TONIGHT INTO
WEDNESDAY MORNING...VERY COLD TEMPERATURES/WIND CHILLS WEDNESDAY
NIGHT AND ANOTHER POSSIBLE ACCUMULATING SNOW EVENT LATE FRIDAY
NIGHT INTO SATURDAY.
TEMPERATURES HAVE REBOUNDED QUITE A BIT FROM THIS MORNING/S SUB
ZERO READINGS WITH MANY AREAS IN THE LOWER/MID 20S. AS GUSTY WINDS
DIMINISH LATE THIS AFTERNOON INTO THIS EVENING...EXPECT TEMPS TO
STEADILY DROP INTO THE LOWER/MID TEENS AND THEN BECOME STEADY BY
LATE EVENING AND BEGIN RISING OVERNIGHT...POSSIBLY INTO THE LOWER
20S BY DAYBREAK.
A WEAK CLIPPER SYSTEM WILL MOVE ACROSS IOWA THIS EVENING AND THEN
ACROSS NORTHERN IL OVERNIGHT AND INTO NORTHWEST INDIANA WEDNESDAY
MORNING. FAIRLY GOOD AGREEMENT AMONG THE MODELS WITH A BAND OF
SNOW SPREADING INTO THE WESTERN CWA AROUND/SHORTLY AFTER MIDNIGHT
AND THEN ACROSS THE REST OF THE AREA DURING THE EARLY MORNING
HOURS...BEFORE SUNRISE. WHILE QPF AMOUNTS MAY ONLY RANGE IN THE
0.15 INCH RANGE...THE AIRMASS IS QUITE COLD AND EXPECT SNOW/WATER
RATIOS IN THE 18:1 TO 20:1 RANGE. THUS THE SNOW SHOULD BE QUITE
DRY AND FLUFFY. HAVE BUMPED QPF AMOUNTS AND SNOWFALL AMOUNTS UP
SLIGHTLY...GENERALLY IN THE 2.5 TO 3 INCH RANGE ALONG AND NORTH OF
INTERSTATE 80. AMOUNTS WILL QUICKLY TAPER OFF INTO THE SOUTHERN
THIRD OF THE CWA. THIS LOW BEGINS TO FILL SOME BY WEDNESDAY
MORNING AND AMOUNTS MAY BE HIGHER WESTERN AREAS THEN EASTERN
AREAS. THE ONE CONCERNING FACTOR IS THE GROWTH ZONE OF -10C TO
-14C WHICH BASED OF THE FORECAST SOUNDINGS COULD BE 150MB TO EVEN
200MB DEEP. THIS COULD ALLOW FOR SOME EFFICIENT SNOW DEVELOPMENT
ALONG WITH LARGE FLAKES...WHICH WOULD ALLOW FOR EVEN HIGHER
SNOWFALL AMOUNTS. THIS COULD ALSO LEAD TO SNOWFALL RATES
APPROACHING AN INCH AN HOUR FOR AT LEAST A SHORT TIME. WITH ALL
THIS IN MIND...WILL BE EXTENDING THE SNOW ADVISORY NORTH TO
INCLUDE THE FOUR NORTHERN COUNTIES AND MENTIONING STORM TOTAL
SNOWFALL AMOUNTS OF 2 TO 4 INCHES...WITH SOME UNCERTAINTY
REGARDING HOW WIDESPREAD THE 3 TO 4 INCH AMOUNTS MAY MATERIALIZE.
THE SNOW WILL TAPER OFF QUICKLY FROM WEST TO EAST AFTER SUNRISE
WITH NORTHWEST WINDS INCREASING AS THE SNOW ENDS AND THEN
REMAINING GUSTY INTO THE AFTERNOON. WIND GUSTS INTO THE 20-25 MPH
RANGE LOOK REASONABLE WHICH MAY CAUSE SOME BLOWING AND DRIFTING
SNOW BUT WILL MAINTAIN CURRENT ADVISORY EXPIRATION TIME OF 16Z
WEDNESDAY FOR NOW.
HIGH TEMPS WEDNESDAY WILL BE REACHED IN THE MORNING WITH STEADILY
FALLING TEMPS THROUGH THE AFTERNOON INTO WEDNESDAY NIGHT...WHICH
IS SHAPING UP TO BE VERY SIMILAR TO THIS MORNING. TEMPERATURES
WILL DIVE IN THE EVENING AND THEN BEGIN TO STEADY OVERNIGHT AND
POSSIBLY BEGIN TO RISE BY THURSDAY MORNING AS CLOUD COVER AND WEAK
WARM ADVECTION MOVE ACROSS THE REGION. BUT WITH A FRESH SNOW COVER
AND CLEARING SKIES...TEMPS SHOULD FALL BELOW ZERO JUST ABOUT
EVERYWHERE WITH THE USUAL COLD SPOTS PERHAPS INTO THE -10 RANGE.
THIS COMBINED WITH WESTERLY WINDS TURNING SOUTHWESTERLY...BUT IN
THE 10 MPH RANGE WILL PRODUCE WIND CHILLS FROM -15 TO -25 WITH
SOME LOCALLY LOWER VALUES. IF THESE TRENDS CONTINUE A WIND CHILL
ADVISORY MAY BE NEEDED DURING THIS TIME PERIOD.
TEMPS MODERATE SLIGHTLY THURSDAY INTO FRIDAY...THOUGH STILL BELOW
NORMAL. A COLD FRONT WILL SAG SOUTH ACROSS THE LAKES REGION
THURSDAY NIGHT AND FRIDAY...REACHING NORTHERN IL FRIDAY AFTERNOON.
MEANWHILE...LOW PRESSURE OVER THE SOUTHERN PLAINS LIFTS NORTHEAST
ACROSS THE OHIO VALLEY SATURDAY AND TO THE EASTERN LAKES BY SUNDAY
MORNING. A PROLONGED PERIOD OF LIGHT TO MODERATE SNOW WILL LIKELY
BEGIN FRIDAY NIGHT AND CONTINUE THROUGH MUCH OF SATURDAY WITH SOME
DIFFERENCES REGARDING THE CORRIDOR OF HEAVIEST QPF. BUT WITH
AMOUNTS IN THE 0.3 TO 0.5 RANGE...SEVERAL INCHES OF SNOW WILL BE
POSSIBLE. BUT WITH WARMER TEMPERATURES...PERHAPS NEAR FREEZING ON
SATURDAY...SNOW RATIOS SHOULD BE CLOSER TO 10:1 WITH A HEAVIER/WET
SNOW MOST LIKELY.
ANOTHER COLD DUMP SATURDAY NIGHT INTO SUNDAY. AND WHILE THE
STRENGTH OF COLD AIR IS STILL A BIT UNCERTAIN HAVE LOWERED TEMPS
SATURDAY NIGHT AND SUNDAY AND IF THIS MORNING AND WEDNESDAY NIGHT
ARE GOOD INDICATORS...TEMPS COULD BE SIGNIFICANTLY COLDER THAN
CURRENTLY ADVERTISED. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MODERATE SNOWFALL INTO THE PREDAWN HOURS REDUCING VSBY TO IFR AND
RESULTING IN 1 TO 3 INCHES OF SNOW ACCUMULATION.
BMD
//DISCUSSION...UPDATED 06Z...
WINTER SYSTEM IS BRINGING AREA OF SNOW OVER IOWA LATE THIS
EVENING...AND WILL BE SPREADING EAST ACROSS NORTHERN ILLINOIS OVER
THE NEXT FEW HOURS. EXPECT VSBY TO FAIRLY QUICKLY DROP TO 1-2SM AS
THE SNOW BEGINS. THE BEST FORCING AND HEAVIEST SNOWFALL IS EXPECTED
TO BETWEEN ROUGHLY 8Z AND 12Z THIS EVENING WHERE VSBY MAY FALL UNDER
A MILE. QUITE A BIT A VARIABILITY IN CIGS UPSTREAM...BUT SHOULD
MAINLY BE IN THE 015-020 RANGE WITH TEMPO LOWER POSSIBLY IFR CIGS AT
TIMES. SNOW WILL BEGIN TO LET UP AROUND DAYBREAK WEDNESDAY MORNING
WHEN 2 TO 4 INCHES OF SNOW IS EXPECTED TO HAVE FALLEN. NORTHWEST
WINDS WITH GUSTS TO AROUND 20 KT ARE EXPECTED FROM MID MORNING
THROUGH MID AFTERNOON...THEN SHOULD EASE AND BEGIN TO BACK TO TO
WEST WEDNESDAY EVENING AS HIGH PRESSURE BUILDS DOWNSTATE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* HIGH CONFIDENCE IN SNOWFALL INTENSITY AND TIMING.
* MEDIUM-HIGH CONFIDENCE IN VSBY TRENDS.
* MEDIUM CONFIDENCE IN CIG TRENDS...LOWER CONFIDENCE IN TIMING
IMPROVEMENT TO VFR MIDDAY WEDNESDAY.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR.
FRIDAY...SNOW ESPECIALLY OVERNIGHT.
SATURDAY...SNOW DURING THE DAY...TAPERING OFF AT NIGHT. MVFR OR
LOWER PSBL.
SUNDAY...CHANCE OF SNOW EARLY WITH CONDITIONS IMPROVING TO VFR
THROUGH THE DAY.
MONDAY...CHANCE OF SNOW...VFR.
JEE
&&
.MARINE...
214 AM CST
WINDS HAVE DIMINISHED BELOW GALES BUT WILL REMAIN BREEZY THROUGH AT
LEAST LATE THURSDAY AS A STRONG HIGH BUILDS ACROSS THE PLAINS
TOWARDS THE MID MISSISSIPPI VALLEY RESULTING IN A MODERATE PRESSURE
GRADIENT OVER THE LAKE. WILL HOIST A SMALL CRAFT ADVISORY FOR THE
ILLINOIS AND INDIANA NEARSHORE WATERS STARTING MID MORNING TODAY.
THE ADVISORY FOR THE ILLINOIS WATERS WILL RUN THROUGH LATE THIS
EVENING WHEN WINDS SHOULD DROP BELOW CRITERIA OVERNIGHT WITH
OFFSHORE FLOW. THE INDIANA SHORES THOUGH WILL LIKELY EXPERIENCE
HAZARDOUS CONDITIONS FOR SMALL CRAFT THROUGH MID TO LATE THURSDAY AS
WAVES SLOWLY DIMINISH IN THE MODERATE NORTHWEST FLOW. WINDS BRIEFLY
ABATE THURSDAY NIGHT INTO EARLY FRIDAY AS A NEUTRAL POINT PUSHES
OVER THE REGION...BUT THEN ARE EXPECTED TO PICK UP AGAIN OUT OF THE
EAST/NORTHEAST LATE FRIDAY AS LOW PRESSURE DEEPENS OVER THE LOWER
MISSISSIPPI VALLEY AND LIFTS INTO THE OHIO VALLEY SATURDAY. A RIDGE
WILL BUILD ACROSS THE LAKE LATE NEXT WEEKEND AND SHOULD ALLOW FOR
ANOTHER LULL IN THE WINDS.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022 UNTIL 10 AM WEDNESDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-ILZ022-
ILZ023-ILZ032...6 PM WEDNESDAY TO 5 AM THURSDAY.
IN...WIND CHILL ADVISORY...INZ001-INZ002...6 PM WEDNESDAY TO 5 AM
THURSDAY.
WINTER WEATHER ADVISORY...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...SMALL CRAFT ADVISORY...LMZ740-LMZ741-LMZ742-LMZ743...9 AM
WEDNESDAY TO 10 PM WEDNESDAY.
SMALL CRAFT ADVISORY...LMZ744-LMZ745...9 AM WEDNESDAY TO 3 PM
THURSDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
215 AM CST WED DEC 11 2013
.DISCUSSION...
920 PM CST
THE CURRENT WINTER WEATHER ADVISORY FOR OVERNIGHT AND WEDNESDAY
MORNING CONTINUES AS IS WITH NO MAJOR CHANGES TO GOING FORECAST
SNOWFALL TIMING OR TOTAL AMOUNTS. HAVE ADDED PATCHY BLOWING SNOW
IN FOR THE MORNING IN THE FAR WEST AND SPREAD IT EASTWARD DURING
THE AFTERNOON AS THE COLD...OR SHOULD WE SAY COLDER...AIR SURGES
BACK IN.
THE POSITIVES TOWARD SNOWFALL WITH THIS SYSTEM REMAIN IN
OBSERVATIONAL AND SHORT TERM GUIDANCE...WITH HIGHER SNOW-TO-
LIQUID RATIOS AND TEMPORARY MODEST RATES...WHILE THE SUBTLE
CAVEATS OF A SOMEWHAT WEAK WAVE AND LOW COLUMN MOISTURE ARE LIKELY
TO BE OFFSET BY THESE ENOUGH TO PRODUCE 2-3.5" SNOWFALL AMOUNTS
AND LIKELY SCATTERED HIGHER AMOUNTS WITHIN THE ADVISORY AREA.
RADAR ECHOES ARE ON THE UPWARD TREND ACROSS CENTRAL IA WITHIN THE
WARM AIR ADVECTION WING OF THE SHORT WAVE SEEN ON WATER VAPOR
PROGRESSING EAST SOUTHEAST. THIS WAVE WILL TURN MORE EAST ALONG A
WELL-DEFINED 850-600MB BAROCLINIC ZONE SEEN ON THIS EVES UPPER
AIR DATA. HAVE ALREADY NOTED 3/4SM VISIBILITY IN IA...LIKELY
ASSOCIATED WITH ONE HALF TO ONE INCH PER HOUR TYPE RATES. WITH
CLIPPER SYSTEMS IT SEEMS THAT THE LOWEST VISIBILITY CAN OFTEN BE
EXTRAPOLATED OUT ALONG THE PATH GIVEN THE WAVE MAINTAINS ITS
INTENSITY. THE RAP CONTINUES TO SHOW A FAIRLY QUICK PROGRESSION
OF THE LEADING EDGE OF SNOW OVER MUCH OF THE FORECAST AREA BETWEEN
12AM-3AM...SO DID NOT GET FANCY WITH TRYING TO ADJUST THE ADVISORY
START TIME. TEMPORARY WEST-TO-EAST BANDED SNOW OVERNIGHT WOULD
SEEM PROBABLE IN NORTH CENTRAL IL...MAYBE INTO THE CHICAGO
METRO...ALONG THE BAROCLINIC ZONE AND FAIRLY WELL-DEFINED
MOISTURE CONVERGENCE. CONVECTIVE ALLOWING/HIGH RES GUIDANCE
INDICATES HIGHER REFLECTIVITY AS WELL IN THE 3-8 AM PERIOD. SNOW
LOOKS TO LINGER OVER CHICAGO THROUGH THE END OF THE ADVISORY TIME.
FORECAST SOUNDINGS CONTINUE TO INDICATE A VERY DEEP DENDRITIC
GROWTH AREA WITH NOT OVERLY HIGH WINDS BELOW THE CLOUD BASE FOR
FRAGMENTING. EVEN THE 00Z DVN SOUNDING HAD THE WET BULB
TEMPERATURE BASICALLY WITHIN THE DENDRITIC GROWTH AREA ALL THE WAY
TO ~10000 FT! THIS SHOULD ALLOW FOR GOOD EFFICIENCY (20:1) OF
MEAGER PWAT VALUES UNDER 0.2 INCH AND MIXING RATIOS IN THE CLOUD
LAYER OF 1-1.5 G/KG. SO WE CONTINUE A LITTLE HIGHER THAT MOST
GUIDANCE FOR SNOWFALL AMOUNTS.
THE MOST PROBABLE TIMING FOR HEAVIEST SNOWFALL RATES IN ROCKFORD
IS 2-6 AM AND CHICAGO IS 4-8 AM. TEMPERATURES SHOULD CONTINUE TO
INCH UP PRIOR TO THE SNOWFALL...AND THEN HOLD STEADY IN THE MID-
UPPER TEENS DURING THE SNOW.
MTF
//PREV DISCUSSION...
250 PM...FORECAST CONCERNS INCLUDE ACCUMULATING SNOW TONIGHT INTO
WEDNESDAY MORNING...VERY COLD TEMPERATURES/WIND CHILLS WEDNESDAY
NIGHT AND ANOTHER POSSIBLE ACCUMULATING SNOW EVENT LATE FRIDAY
NIGHT INTO SATURDAY.
TEMPERATURES HAVE REBOUNDED QUITE A BIT FROM THIS MORNING/S SUB
ZERO READINGS WITH MANY AREAS IN THE LOWER/MID 20S. AS GUSTY WINDS
DIMINISH LATE THIS AFTERNOON INTO THIS EVENING...EXPECT TEMPS TO
STEADILY DROP INTO THE LOWER/MID TEENS AND THEN BECOME STEADY BY
LATE EVENING AND BEGIN RISING OVERNIGHT...POSSIBLY INTO THE LOWER
20S BY DAYBREAK.
A WEAK CLIPPER SYSTEM WILL MOVE ACROSS IOWA THIS EVENING AND THEN
ACROSS NORTHERN IL OVERNIGHT AND INTO NORTHWEST INDIANA WEDNESDAY
MORNING. FAIRLY GOOD AGREEMENT AMONG THE MODELS WITH A BAND OF
SNOW SPREADING INTO THE WESTERN CWA AROUND/SHORTLY AFTER MIDNIGHT
AND THEN ACROSS THE REST OF THE AREA DURING THE EARLY MORNING
HOURS...BEFORE SUNRISE. WHILE QPF AMOUNTS MAY ONLY RANGE IN THE
0.15 INCH RANGE...THE AIRMASS IS QUITE COLD AND EXPECT SNOW/WATER
RATIOS IN THE 18:1 TO 20:1 RANGE. THUS THE SNOW SHOULD BE QUITE
DRY AND FLUFFY. HAVE BUMPED QPF AMOUNTS AND SNOWFALL AMOUNTS UP
SLIGHTLY...GENERALLY IN THE 2.5 TO 3 INCH RANGE ALONG AND NORTH OF
INTERSTATE 80. AMOUNTS WILL QUICKLY TAPER OFF INTO THE SOUTHERN
THIRD OF THE CWA. THIS LOW BEGINS TO FILL SOME BY WEDNESDAY
MORNING AND AMOUNTS MAY BE HIGHER WESTERN AREAS THEN EASTERN
AREAS. THE ONE CONCERNING FACTOR IS THE GROWTH ZONE OF -10C TO
-14C WHICH BASED OF THE FORECAST SOUNDINGS COULD BE 150MB TO EVEN
200MB DEEP. THIS COULD ALLOW FOR SOME EFFICIENT SNOW DEVELOPMENT
ALONG WITH LARGE FLAKES...WHICH WOULD ALLOW FOR EVEN HIGHER
SNOWFALL AMOUNTS. THIS COULD ALSO LEAD TO SNOWFALL RATES
APPROACHING AN INCH AN HOUR FOR AT LEAST A SHORT TIME. WITH ALL
THIS IN MIND...WILL BE EXTENDING THE SNOW ADVISORY NORTH TO
INCLUDE THE FOUR NORTHERN COUNTIES AND MENTIONING STORM TOTAL
SNOWFALL AMOUNTS OF 2 TO 4 INCHES...WITH SOME UNCERTAINTY
REGARDING HOW WIDESPREAD THE 3 TO 4 INCH AMOUNTS MAY MATERIALIZE.
THE SNOW WILL TAPER OFF QUICKLY FROM WEST TO EAST AFTER SUNRISE
WITH NORTHWEST WINDS INCREASING AS THE SNOW ENDS AND THEN
REMAINING GUSTY INTO THE AFTERNOON. WIND GUSTS INTO THE 20-25 MPH
RANGE LOOK REASONABLE WHICH MAY CAUSE SOME BLOWING AND DRIFTING
SNOW BUT WILL MAINTAIN CURRENT ADVISORY EXPIRATION TIME OF 16Z
WEDNESDAY FOR NOW.
HIGH TEMPS WEDNESDAY WILL BE REACHED IN THE MORNING WITH STEADILY
FALLING TEMPS THROUGH THE AFTERNOON INTO WEDNESDAY NIGHT...WHICH
IS SHAPING UP TO BE VERY SIMILAR TO THIS MORNING. TEMPERATURES
WILL DIVE IN THE EVENING AND THEN BEGIN TO STEADY OVERNIGHT AND
POSSIBLY BEGIN TO RISE BY THURSDAY MORNING AS CLOUD COVER AND WEAK
WARM ADVECTION MOVE ACROSS THE REGION. BUT WITH A FRESH SNOW COVER
AND CLEARING SKIES...TEMPS SHOULD FALL BELOW ZERO JUST ABOUT
EVERYWHERE WITH THE USUAL COLD SPOTS PERHAPS INTO THE -10 RANGE.
THIS COMBINED WITH WESTERLY WINDS TURNING SOUTHWESTERLY...BUT IN
THE 10 MPH RANGE WILL PRODUCE WIND CHILLS FROM -15 TO -25 WITH
SOME LOCALLY LOWER VALUES. IF THESE TRENDS CONTINUE A WIND CHILL
ADVISORY MAY BE NEEDED DURING THIS TIME PERIOD.
TEMPS MODERATE SLIGHTLY THURSDAY INTO FRIDAY...THOUGH STILL BELOW
NORMAL. A COLD FRONT WILL SAG SOUTH ACROSS THE LAKES REGION
THURSDAY NIGHT AND FRIDAY...REACHING NORTHERN IL FRIDAY AFTERNOON.
MEANWHILE...LOW PRESSURE OVER THE SOUTHERN PLAINS LIFTS NORTHEAST
ACROSS THE OHIO VALLEY SATURDAY AND TO THE EASTERN LAKES BY SUNDAY
MORNING. A PROLONGED PERIOD OF LIGHT TO MODERATE SNOW WILL LIKELY
BEGIN FRIDAY NIGHT AND CONTINUE THROUGH MUCH OF SATURDAY WITH SOME
DIFFERENCES REGARDING THE CORRIDOR OF HEAVIEST QPF. BUT WITH
AMOUNTS IN THE 0.3 TO 0.5 RANGE...SEVERAL INCHES OF SNOW WILL BE
POSSIBLE. BUT WITH WARMER TEMPERATURES...PERHAPS NEAR FREEZING ON
SATURDAY...SNOW RATIOS SHOULD BE CLOSER TO 10:1 WITH A HEAVIER/WET
SNOW MOST LIKELY.
ANOTHER COLD DUMP SATURDAY NIGHT INTO SUNDAY. AND WHILE THE
STRENGTH OF COLD AIR IS STILL A BIT UNCERTAIN HAVE LOWERED TEMPS
SATURDAY NIGHT AND SUNDAY AND IF THIS MORNING AND WEDNESDAY NIGHT
ARE GOOD INDICATORS...TEMPS COULD BE SIGNIFICANTLY COLDER THAN
CURRENTLY ADVERTISED. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MODERATE SNOWFALL OVERSPREADING THE TERMINALS LATE THIS EVENING
AND EARLY OVERNIGHT REDUCING VSBY TO IFR OR LOWER AND RESULTING
IN 2 TO 4 INCHES OF SNOW ACCUMULATION.
BMD
//DISCUSSION...UPDATED 06Z...
WINTER SYSTEM IS BRINGING AREA OF SNOW OVER IOWA LATE THIS
EVENING...AND WILL BE SPREADING EAST ACROSS NORTHERN ILLINOIS OVER
THE NEXT FEW HOURS. EXPECT VSBY TO FAIRLY QUICKLY DROP TO 1-2SM AS
THE SNOW BEGINS. THE BEST FORCING AND HEAVIEST SNOWFALL IS EXPECTED
TO BETWEEN ROUGHLY 8Z AND 12Z THIS EVENING WHERE VSBY MAY FALL UNDER
A MILE. QUITE A BIT A VARIABILITY IN CIGS UPSTREAM...BUT SHOULD
MAINLY BE IN THE 015-020 RANGE WITH TEMPO LOWER POSSIBLY IFR CIGS AT
TIMES. SNOW WILL BEGIN TO LET UP AROUND DAYBREAK WEDNESDAY MORNING
WHEN 2 TO 4 INCHES OF SNOW IS EXPECTED TO HAVE FALLEN. NORTHWEST
WINDS WITH GUSTS TO AROUND 20 KT ARE EXPECTED FROM MID MORNING
THROUGH MID AFTERNOON...THEN SHOULD EASE AND BEGIN TO BACK TO TO
WEST WEDNESDAY EVENING AS HIGH PRESSURE BUILDS DOWNSTATE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN SNOWFALL INTENSITY AND TIMING.
* MEDIUM-HIGH CONFIDENCE IN VSBY TRENDS.
* MEDIUM CONFIDENCE IN CIG TRENDS...LOWER CONFIDENCE IN TIMING
IMPROVEMENT TO VFR MIDDAY WEDNESDAY.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR.
FRIDAY...SNOW ESPECIALLY OVERNIGHT.
SATURDAY...SNOW DURING THE DAY...TAPERING OFF AT NIGHT. MVFR OR
LOWER PSBL.
SUNDAY...CHANCE OF SNOW EARLY WITH CONDITIONS IMPROVING TO VFR
THROUGH THE DAY.
MONDAY...CHANCE OF SNOW...VFR.
JEE
&&
.MARINE...
214 AM CST
WINDS HAVE DIMINISHED BELOW GALES BUT WILL REMAIN BREEZY THROUGH AT
LEAST LATE THURSDAY AS A STRONG HIGH BUILDS ACROSS THE PLAINS
TOWARDS THE MID MISSISSIPPI VALLEY RESULTING IN A MODERATE PRESSURE
GRADIENT OVER THE LAKE. WILL HOIST A SMALL CRAFT ADVISORY FOR THE
ILLINOIS AND INDIANA NEARSHORE WATERS STARTING MID MORNING TODAY.
THE ADVISORY FOR THE ILLINOIS WATERS WILL RUN THROUGH LATE THIS
EVENING WHEN WINDS SHOULD DROP BELOW CRITERIA OVERNIGHT WITH
OFFSHORE FLOW. THE INDIANA SHORES THOUGH WILL LIKELY EXPERIENCE
HAZARDOUS CONDITIONS FOR SMALL CRAFT THROUGH MID TO LATE THURSDAY AS
WAVES SLOWLY DIMINISH IN THE MODERATE NORTHWEST FLOW. WINDS BRIEFLY
ABATE THURSDAY NIGHT INTO EARLY FRIDAY AS A NEUTRAL POINT PUSHES
OVER THE REGION...BUT THEN ARE EXPECTED TO PICK UP AGAIN OUT OF THE
EAST/NORTHEAST LATE FRIDAY AS LOW PRESSURE DEEPENS OVER THE LOWER
MISSISSIPPI VALLEY AND LIFTS INTO THE OHIO VALLEY SATURDAY. A RIDGE
WILL BUILD ACROSS THE LAKE LATE NEXT WEEKEND AND SHOULD ALLOW FOR
ANOTHER LULL IN THE WINDS.
BMD
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022 UNTIL 10 AM WEDNESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...NONE.
&&
$$
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AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1147 PM CST TUE DEC 10 2013
.DISCUSSION...
920 PM CST
THE CURRENT WINTER WEATHER ADVISORY FOR OVERNIGHT AND WEDNESDAY
MORNING CONTINUES AS IS WITH NO MAJOR CHANGES TO GOING FORECAST
SNOWFALL TIMING OR TOTAL AMOUNTS. HAVE ADDED PATCHY BLOWING SNOW
IN FOR THE MORNING IN THE FAR WEST AND SPREAD IT EASTWARD DURING
THE AFTERNOON AS THE COLD...OR SHOULD WE SAY COLDER...AIR SURGES
BACK IN.
THE POSITIVES TOWARD SNOWFALL WITH THIS SYSTEM REMAIN IN
OBSERVATIONAL AND SHORT TERM GUIDANCE...WITH HIGHER SNOW-TO-
LIQUID RATIOS AND TEMPORARY MODEST RATES...WHILE THE SUBTLE
CAVEATS OF A SOMEWHAT WEAK WAVE AND LOW COLUMN MOISTURE ARE LIKELY
TO BE OFFSET BY THESE ENOUGH TO PRODUCE 2-3.5" SNOWFALL AMOUNTS
AND LIKELY SCATTERED HIGHER AMOUNTS WITHIN THE ADVISORY AREA.
RADAR ECHOES ARE ON THE UPWARD TREND ACROSS CENTRAL IA WITHIN THE
WARM AIR ADVECTION WING OF THE SHORT WAVE SEEN ON WATER VAPOR
PROGRESSING EAST SOUTHEAST. THIS WAVE WILL TURN MORE EAST ALONG A
WELL-DEFINED 850-600MB BAROCLINIC ZONE SEEN ON THIS EVES UPPER
AIR DATA. HAVE ALREADY NOTED 3/4SM VISIBILITY IN IA...LIKELY
ASSOCIATED WITH ONE HALF TO ONE INCH PER HOUR TYPE RATES. WITH
CLIPPER SYSTEMS IT SEEMS THAT THE LOWEST VISIBILITY CAN OFTEN BE
EXTRAPOLATED OUT ALONG THE PATH GIVEN THE WAVE MAINTAINS ITS
INTENSITY. THE RAP CONTINUES TO SHOW A FAIRLY QUICK PROGRESSION
OF THE LEADING EDGE OF SNOW OVER MUCH OF THE FORECAST AREA BETWEEN
12AM-3AM...SO DID NOT GET FANCY WITH TRYING TO ADJUST THE ADVISORY
START TIME. TEMPORARY WEST-TO-EAST BANDED SNOW OVERNIGHT WOULD
SEEM PROBABLE IN NORTH CENTRAL IL...MAYBE INTO THE CHICAGO
METRO...ALONG THE BAROCLINIC ZONE AND FAIRLY WELL-DEFINED
MOISTURE CONVERGENCE. CONVECTIVE ALLOWING/HIGH RES GUIDANCE
INDICATES HIGHER REFLECTIVITY AS WELL IN THE 3-8 AM PERIOD. SNOW
LOOKS TO LINGER OVER CHICAGO THROUGH THE END OF THE ADVISORY TIME.
FORECAST SOUNDINGS CONTINUE TO INDICATE A VERY DEEP DENDRITIC
GROWTH AREA WITH NOT OVERLY HIGH WINDS BELOW THE CLOUD BASE FOR
FRAGMENTING. EVEN THE 00Z DVN SOUNDING HAD THE WET BULB
TEMPERATURE BASICALLY WITHIN THE DENDRITIC GROWTH AREA ALL THE WAY
TO ~10000 FT! THIS SHOULD ALLOW FOR GOOD EFFICIENCY (20:1) OF
MEAGER PWAT VALUES UNDER 0.2 INCH AND MIXING RATIOS IN THE CLOUD
LAYER OF 1-1.5 G/KG. SO WE CONTINUE A LITTLE HIGHER THAT MOST
GUIDANCE FOR SNOWFALL AMOUNTS.
THE MOST PROBABLE TIMING FOR HEAVIEST SNOWFALL RATES IN ROCKFORD
IS 2-6 AM AND CHICAGO IS 4-8 AM. TEMPERATURES SHOULD CONTINUE TO
INCH UP PRIOR TO THE SNOWFALL...AND THEN HOLD STEADY IN THE MID-
UPPER TEENS DURING THE SNOW.
MTF
//PREV DISCUSSION...
250 PM...FORECAST CONCERNS INCLUDE ACCUMULATING SNOW TONIGHT INTO
WEDNESDAY MORNING...VERY COLD TEMPERATURES/WIND CHILLS WEDNESDAY
NIGHT AND ANOTHER POSSIBLE ACCUMULATING SNOW EVENT LATE FRIDAY
NIGHT INTO SATURDAY.
TEMPERATURES HAVE REBOUNDED QUITE A BIT FROM THIS MORNING/S SUB
ZERO READINGS WITH MANY AREAS IN THE LOWER/MID 20S. AS GUSTY WINDS
DIMINISH LATE THIS AFTERNOON INTO THIS EVENING...EXPECT TEMPS TO
STEADILY DROP INTO THE LOWER/MID TEENS AND THEN BECOME STEADY BY
LATE EVENING AND BEGIN RISING OVERNIGHT...POSSIBLY INTO THE LOWER
20S BY DAYBREAK.
A WEAK CLIPPER SYSTEM WILL MOVE ACROSS IOWA THIS EVENING AND THEN
ACROSS NORTHERN IL OVERNIGHT AND INTO NORTHWEST INDIANA WEDNESDAY
MORNING. FAIRLY GOOD AGREEMENT AMONG THE MODELS WITH A BAND OF
SNOW SPREADING INTO THE WESTERN CWA AROUND/SHORTLY AFTER MIDNIGHT
AND THEN ACROSS THE REST OF THE AREA DURING THE EARLY MORNING
HOURS...BEFORE SUNRISE. WHILE QPF AMOUNTS MAY ONLY RANGE IN THE
0.15 INCH RANGE...THE AIRMASS IS QUITE COLD AND EXPECT SNOW/WATER
RATIOS IN THE 18:1 TO 20:1 RANGE. THUS THE SNOW SHOULD BE QUITE
DRY AND FLUFFY. HAVE BUMPED QPF AMOUNTS AND SNOWFALL AMOUNTS UP
SLIGHTLY...GENERALLY IN THE 2.5 TO 3 INCH RANGE ALONG AND NORTH OF
INTERSTATE 80. AMOUNTS WILL QUICKLY TAPER OFF INTO THE SOUTHERN
THIRD OF THE CWA. THIS LOW BEGINS TO FILL SOME BY WEDNESDAY
MORNING AND AMOUNTS MAY BE HIGHER WESTERN AREAS THEN EASTERN
AREAS. THE ONE CONCERNING FACTOR IS THE GROWTH ZONE OF -10C TO
-14C WHICH BASED OF THE FORECAST SOUNDINGS COULD BE 150MB TO EVEN
200MB DEEP. THIS COULD ALLOW FOR SOME EFFICIENT SNOW DEVELOPMENT
ALONG WITH LARGE FLAKES...WHICH WOULD ALLOW FOR EVEN HIGHER
SNOWFALL AMOUNTS. THIS COULD ALSO LEAD TO SNOWFALL RATES
APPROACHING AN INCH AN HOUR FOR AT LEAST A SHORT TIME. WITH ALL
THIS IN MIND...WILL BE EXTENDING THE SNOW ADVISORY NORTH TO
INCLUDE THE FOUR NORTHERN COUNTIES AND MENTIONING STORM TOTAL
SNOWFALL AMOUNTS OF 2 TO 4 INCHES...WITH SOME UNCERTAINTY
REGARDING HOW WIDESPREAD THE 3 TO 4 INCH AMOUNTS MAY MATERIALIZE.
THE SNOW WILL TAPER OFF QUICKLY FROM WEST TO EAST AFTER SUNRISE
WITH NORTHWEST WINDS INCREASING AS THE SNOW ENDS AND THEN
REMAINING GUSTY INTO THE AFTERNOON. WIND GUSTS INTO THE 20-25 MPH
RANGE LOOK REASONABLE WHICH MAY CAUSE SOME BLOWING AND DRIFTING
SNOW BUT WILL MAINTAIN CURRENT ADVISORY EXPIRATION TIME OF 16Z
WEDNESDAY FOR NOW.
HIGH TEMPS WEDNESDAY WILL BE REACHED IN THE MORNING WITH STEADILY
FALLING TEMPS THROUGH THE AFTERNOON INTO WEDNESDAY NIGHT...WHICH
IS SHAPING UP TO BE VERY SIMILAR TO THIS MORNING. TEMPERATURES
WILL DIVE IN THE EVENING AND THEN BEGIN TO STEADY OVERNIGHT AND
POSSIBLY BEGIN TO RISE BY THURSDAY MORNING AS CLOUD COVER AND WEAK
WARM ADVECTION MOVE ACROSS THE REGION. BUT WITH A FRESH SNOW COVER
AND CLEARING SKIES...TEMPS SHOULD FALL BELOW ZERO JUST ABOUT
EVERYWHERE WITH THE USUAL COLD SPOTS PERHAPS INTO THE -10 RANGE.
THIS COMBINED WITH WESTERLY WINDS TURNING SOUTHWESTERLY...BUT IN
THE 10 MPH RANGE WILL PRODUCE WIND CHILLS FROM -15 TO -25 WITH
SOME LOCALLY LOWER VALUES. IF THESE TRENDS CONTINUE A WIND CHILL
ADVISORY MAY BE NEEDED DURING THIS TIME PERIOD.
TEMPS MODERATE SLIGHTLY THURSDAY INTO FRIDAY...THOUGH STILL BELOW
NORMAL. A COLD FRONT WILL SAG SOUTH ACROSS THE LAKES REGION
THURSDAY NIGHT AND FRIDAY...REACHING NORTHERN IL FRIDAY AFTERNOON.
MEANWHILE...LOW PRESSURE OVER THE SOUTHERN PLAINS LIFTS NORTHEAST
ACROSS THE OHIO VALLEY SATURDAY AND TO THE EASTERN LAKES BY SUNDAY
MORNING. A PROLONGED PERIOD OF LIGHT TO MODERATE SNOW WILL LIKELY
BEGIN FRIDAY NIGHT AND CONTINUE THROUGH MUCH OF SATURDAY WITH SOME
DIFFERENCES REGARDING THE CORRIDOR OF HEAVIEST QPF. BUT WITH
AMOUNTS IN THE 0.3 TO 0.5 RANGE...SEVERAL INCHES OF SNOW WILL BE
POSSIBLE. BUT WITH WARMER TEMPERATURES...PERHAPS NEAR FREEZING ON
SATURDAY...SNOW RATIOS SHOULD BE CLOSER TO 10:1 WITH A HEAVIER/WET
SNOW MOST LIKELY.
ANOTHER COLD DUMP SATURDAY NIGHT INTO SUNDAY. AND WHILE THE
STRENGTH OF COLD AIR IS STILL A BIT UNCERTAIN HAVE LOWERED TEMPS
SATURDAY NIGHT AND SUNDAY AND IF THIS MORNING AND WEDNESDAY NIGHT
ARE GOOD INDICATORS...TEMPS COULD BE SIGNIFICANTLY COLDER THAN
CURRENTLY ADVERTISED. CMS
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 06Z...
* MODERATE SNOWFALL OVERSPREADING THE TERMINALS LATE THIS EVENING
AND EARLY OVERNIGHT REDUCING VSBY TO IFR OR LOWER AND RESULTING
IN 2 TO 4 INCHES OF SNOW ACCUMULATION.
BMD
//DISCUSSION...UPDATED 06Z...
WINTER SYSTEM IS BRINGING AREA OF SNOW OVER IOWA LATE THIS
EVENING...AND WILL BE SPREADING EAST ACROSS NORTHERN ILLINOIS OVER
THE NEXT FEW HOURS. EXPECT VSBY TO FAIRLY QUICKLY DROP TO 1-2SM AS
THE SNOW BEGINS. THE BEST FORCING AND HEAVIEST SNOWFALL IS EXPECTED
TO BETWEEN ROUGHLY 8Z AND 12Z THIS EVENING WHERE VSBY MAY FALL UNDER
A MILE. QUITE A BIT A VARIABILITY IN CIGS UPSTREAM...BUT SHOULD
MAINLY BE IN THE 015-020 RANGE WITH TEMPO LOWER POSSIBLY IFR CIGS AT
TIMES. SNOW WILL BEGIN TO LET UP AROUND DAYBREAK WEDNESDAY MORNING
WHEN 2 TO 4 INCHES OF SNOW IS EXPECTED TO HAVE FALLEN. NORTHWEST
WINDS WITH GUSTS TO AROUND 20 KT ARE EXPECTED FROM MID MORNING
THROUGH MID AFTERNOON...THEN SHOULD EASE AND BEGIN TO BACK TO TO
WEST WEDNESDAY EVENING AS HIGH PRESSURE BUILDS DOWNSTATE.
BMD
//ORD AND MDW CONFIDENCE...UPDATED 06Z...
* MEDIUM-HIGH CONFIDENCE IN SNOWFALL INTENSITY AND TIMING.
* MEDIUM-HIGH CONFIDENCE IN VSBY TRENDS.
* MEDIUM CONFIDENCE IN CIG TRENDS...LOWER CONFIDENCE IN TIMING
IMPROVEMENT TO VFR MIDDAY WEDNESDAY.
BMD
//OUTLOOK FOR ORD/MDW FOR 12Z THURSDAY-12Z TUESDAY...UPDATED 00Z...
THURSDAY...VFR.
FRIDAY...SNOW ESPECIALLY OVERNIGHT.
SATURDAY...SNOW DURING THE DAY...TAPERING OFF AT NIGHT. MVFR OR
LOWER PSBL.
SUNDAY...CHANCE OF SNOW EARLY WITH CONDITIONS IMPROVING TO VFR
THROUGH THE DAY.
MONDAY...CHANCE OF SNOW...VFR.
JEE
&&
.MARINE...
145 PM CST
MARINE FORECAST CONCERNS IN ACTIVE PATTERN INCLUDE ONGOING WESTERLY
GALES INTO TONIGHT...THEN AN EXTENDED PERIOD OF WEST-NORTHWEST WINDS
25-30 KT INTO THURSDAY AS ANOTHER ARCTIC HIGH BUILDS THROUGH THE
OHIO VALLEY IN THE WAKE OF ANOTHER CLIPPER. WINDS SHIFT NORTH LATE
THURSDAY NIGHT AS A COLD FRONT SETTLES SOUTH AFTER ANOTHER LOW
PASSES NORTH OF THE LAKES.
LOW PRESSURE WAS LIFTING NORTHEAST ACROSS EASTERN LAKE SUPERIOR THIS
AFTERNOON...WITH A COLD FRONT TRAILING ACROSS WISCONSIN AND FAR
NORTHWEST ILLINOIS. TIGHTENING OF THE GRADIENT IN ASSOCIATION WITH
THE LOW...AND WITH THE PRESSURE RISE/FALL COUPLET WITH THE LOW AND
APPROACHING FRONT HAS RESULTED IN WEST-SOUTHWEST GALES ACROSS THE
SOUTHERN 1/2 OR SO OF LAKE MICHIGAN. WINDS WILL INCREASE THROUGH
LATE AFTERNOON ACROSS NORTHERN LAKE MICHIGAN AS WELL...AS THE LOW
PULLS AWAY TO THE NORTHEAST. FORECAST SOUNDINGS INDICATE THAT GALES
WILL BE A LITTLE MORE MARGINAL ACROSS NORTHERN LAKE MICHIGAN THAN
THEY WERE EARLIER ACROSS THE SOUTH PART OF THE LAKE...WHERE 40+ KT
WINDS OCCURRED DURING THE MID/LATE MORNING HOURS. WEAK HIGH PRESSURE
RIDGING WILL DEVELOP ACROSS THE LAKE TONIGHT...ALLOWING WINDS TO
DECREASE SOMEWHAT...THOUGH THE MAIN HIGH WILL REMAIN WELL TO THE
SOUTH ACROSS THE OHIO VALLEY. THUS A WEST-NORTHWEST GRADIENT WILL
REMAIN ACROSS THE LAKE WHICH WILL CONTINUE TO SUPPORT WESTERLY 25-30
KT WINDS.
A WEAK LOW WILL MOVE QUICKLY ACROSS THE MIDWEST SOUTH OF THE LAKES
WEDNESDAY...WHICH WILL ALLOW A BRIEF DECREASE IN WINDS ACROSS FAR
SOUTHERN LAKE MICHIGAN DURING THE MORNING...THOUGH COLD ARCTIC HIGH
PRESSURE WILL BUILD QUICKLY FROM THE PLAINS INTO THE OHIO VALLEY
WEDNESDAY AFTERNOON AND NIGHT WHICH WILL TIGHTEN UP THE GRADIENT
AGAIN ACROSS THE LAKES. THIS HIGH WILL SLOWLY DRIFT THROUGH AND
SOUTH OF THE OHIO VALLEY THROUGH FRIDAY...WHILE ANOTHER LOW PASSES
NORTH OF THE LAKES. THIS LOW WILL TRAIL A COLD FRONT DOWN THE LAKE
THURSDAY NIGHT...SHIFTING WINDS TO THE NORTH-NORTHEAST FRIDAY.
EAST-NORTHEAST WINDS WILL THEN CONTINUE INTO THE WEEKEND AS YET
ANOTHER LOW/INVERTED TROUGH DEVELOPS ACROSS THE LOWER MISSISSIPPI
AND OHIO VALLEYS.
RATZER
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER WEATHER ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-
ILZ010-ILZ011-ILZ012-ILZ013-ILZ014-ILZ019-ILZ020-ILZ021-
ILZ022 UNTIL 10 AM WEDNESDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002 UNTIL 10 AM WEDNESDAY.
LM...GALE WARNING...LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565 UNTIL 3
AM WEDNESDAY.
&&
$$
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AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
902 PM EST THU DEC 12 2013
.SYNOPSIS...
ISSUED AT 330 PM EST THU DEC 12 2013
HIGH PRESSURE WILL BE OVER THE REGION TONIGHT BUT TEMPERATURES
WILL NOT BE AS COLD AS LAST NIGHT. LOWS WILL STILL DROP INTO THE
LOWER AND MIDDLE TEENS...WITH A FEW SINGLE DIGITS POSSIBLE IN
RURAL AREAS. CLOUDS WILL INCREASE FRIDAY AHEAD OF A STRONG LOW
PRESSURE SYSTEM WHICH WILL BRING ACCUMULATING SNOW TO THE REGION
FRIDAY NIGHT AND SATURDAY. CURRENT INDICATIONS ARE THAT
ACCUMULATIONS BETWEEN 2 AND 5 INCHES WILL BE LIKELY.
&&
.UPDATE...
ISSUED AT 844 PM EST THU DEC 12 2013
UPDATED THIS EVE TO ISSUE A WINTER WEATHER ADVISORY FOR TOMORROW
NIGHT AND SATURDAY. NO SGFNT CHANGES TO GRIDS IN THIS TIMEFRAME.
18Z MODEL RUNS IN DECENT AGREEMENT WITH GOOD RUN-RUN CONTINUITY ON
UPR LOW OPENING UP OVER SWRN U.S. THIS EVE TRACKING NE INTO THE
LWR OH VALLEY BY SATURDAY MORNING. SUB-TROPICAL PLUME ALREADY S-SW
OF THE CIRCULATION IS EXPECTED TO BE DRAWN NORTHWARD OVER THE COLD
AIRMASS IN PLACE OVER THE MIDWEST RESULTING IN WIDESPREAD OVER-
RUNNING SNOW MOVG INTO OUR AREA FRIDAY NIGHT AS THE LOW
APPROACHES... FOLLOWED BY DEFORMATION ZONE SNOWS DURING THE DAY
SATURDAY AS THE VORT MAX MOVES UP THE OH VALLEY. GIVEN THE SYSTEM
IS STILL EXPECTED TO BE IN A WKNG TREND WITH NO CLOSING OFF MID
LEVEL LOW... EXPECT SNOWFALL ACCUMS TO REMAIN BLO WARNING
CRITERIA... BUT WITH DEEP MOISTURE/LIFT THROUGH THE DGZ FCST FOR A
SUBSTANTIAL PERIOD... SGFNT SNOW AMOUNTS SHOULD OCCUR OVER MOST IF
NOT THE ENTIRE AREA FRIDAY NIGHT AND SATURDAY. WITH START OF THE
EVENT NOW APPROX 24HRS OUT AND CONFIDENCE FAIRLY HIGH... FELT
HEADLINE WARRANTED ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 323 PM EST THU DEC 12 2013
FEW CONCERNS THROUGH THE SHORT TERM PERIOD AS SIGNIFICANT WEATHER
AHEAD OF NEXT SYSTEM WILL HOLD OFF UNTIL FRIDAY NIGHT.
SATELLITE SHOWING MID AND HIGH CLOUDS EXITING SOUTHERN AREAS THIS
AFTERNOON WHILE THERMAL TROUGH SAGGING ACROSS LAKE MICHIGAN WAS
AIDING IN STRATOCU DEVELOPMENT ACROSS BERRIEN AND CASS COUNTIES IN
MICHIGAN. THESE LOW CLOUDS AND ANY LAKE EFFECT SNOW SHOWERS WILL BE
MAIN CHALLENGE TONIGHT. SYNOPTIC SCALE THERMAL TROUGH ALREADY MOVING
EAST BUT LAKE INDUCED TROUGHINESS AND THERMAL DISPARITY PROGGED TO
ONLY SLOWLY WARM OVERNIGHT. SATELLITE ALREADY SHOWING LAKE CLOUDS
INTO NORTHERN BERRIEN COUNTY DESPITE WARM AIR ADVECTION. HIRES
GUIDANCE SUGGEST TRAJECTORIES AND WEAK LAKE AGGREGATE TROUGH MAY
ALLOW CLOUDS TO STREAM ACROSS MICHIGAN COUNTIES THIS EVENING AND
INTO OVERNIGHT HOURS. PREVIOUS SKY COVER GRIDS HAD THIS TREND
HANDLED WELL AND GENERALLY STAYED WITH SIMILAR IDEA. LIGHT SNOW
SHOWERS ALREADY NEAR OR INTO EXTREME NORTHERN TIP OF BERRIEN COUNTY
SO WILL CARRY SCT FLURRIES OR LIGHT SNOW SHOWERS THROUGH THE EVENING
UNTIL WARMER AIR ARRIVES AND FLOW WEAKENS WHICH COULD LEAD TO WEAK
MESOLOW FORMATION OVER BOWL REGION OF LAKE. LITTLE OR NO
ACCUMULATION EXPECTED GIVEN SHALLOW MOISTURE DEPTH IN OUR AREA.
OTHERWISE EXPECT MOSTLY CLEAR SKIES TO START THE EVENING WITH SOME
MID AND HIGH CLOUDS INCREASING LATE.
NAM MODEL SOUNDINGS QUITE BULLISH ON LOW LEVEL MOISTURE AND STRATUS
DEVELOPMENT FRIDAY MORNING. NAM12 HAS BEEN RATHER
AGGRESSIVE WITH THIS IDEA THIS WINTER WITH SEVERAL INSTANCES SHOWING
THIS WITH LITTLE TO NO DEVELOPMENT. LATEST HRRR GIVES SOME CREDENCE
TO THIS SOLUTION IN THE NORTH NEAR WEAK SURFACE BOUNDARY WHERE WINDS
BECOME LIGHT. HAVE SLOWLY INCREASED CLOUDS ACROSS THE NORTH
AND NORTHWEST WITH POTENTIAL FOR SOME MID AND HIGH CLOUDS AS WELL.
THIS SHOULD KEEP TEMPS FROM FALLING TOO MUCH OVERNIGHT WITH WARM AIR
ADVECTION WELL UNDERWAY. LOOKING FOR LOWS IN THE 10 TO 15 DEGREE
RANGE LATE EVENING WITH STEADY OR EVEN SLOWLY RISING TEMPS LATE WITH
ANY CLOUD COVER DEVELOPMENT.
COL AREA ASSOCIATED WITH WEAK BOUNDARY WILL LIE ACROSS NW FORECAST
AREA FRIDAY WITH GENERALLY LIGHT WINDS. CLOUD COVER REMAINS TRICKY
DEPENDING ON HOW MUCH SATURATION OCCURS NEAR BOUNDARY WITH INVERSION
ALOFT COURTESY OF WARM AIR ADVECTION. HIGHS WILL REACH MID TO UPPER
20S MOST AREAS WITH LOW 30S POSSIBLE FAR SOUTHWEST AHEAD OF NEXT
STRONG SHORT WAVE. BULK OF PCPN WILL HOLD OFF UNTIL FRIDAY EVENING
BUT DID ALLOW A SLIGHT CHANCE TO RESIDE FAR SOUTHWEST AFTER 21Z WITH
PROXIMITY OF INCREASING MOISTURE AND ISENTROPIC LIFT.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 323 PM EST THU DEC 12 2013
...ACCUMULATING SNOWFALL FRIDAY NIGHT-SATURDAY...
PATTERN IS STILL SUPPORTIVE OF FAVORABLE SYNOPTIC SCALE SNOW EVENT
FOR THE REGION BEGINNING LATE FRIDAY NIGHT AND CONTINUING INTO THE
DAY SATURDAY.
NORTHERN STREAM FLOW WILL KEEP THE BOUNDARY LAYER COLD AIR IN PLACE
AND DEEP ENOUGH TO FAVOR ALL SNOW FOR THE EVENT. THE CHALLENGE WILL
BE TIMING THE PHASING OF THE SOUTHERN STREAM AND NORTHERN STREAM
SHORTWAVES ACROSS THE GREAT LAKES.
12Z RUNS ARE GENERALLY CONSISTENT WITH THE SURFACE LOW DEEPENING IN
THE PANHANDLE REGION DURING THE DAY FRIDAY. CONTINUED DEEPENING AND
OF THE SURFACE LOW OVER THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
RIVER VALLEY DURING THE EVENING FRIDAY INTO SATURDAY WILL USHER IN
COPIOUS MOISTURE AND EXPECT TO SEE A PRONOUNCED WARM LAYER SPREADING
NORTHWARD. THIS WILL FAVOR A MORE DENSE AND WET SNOW ACROSS THE
SOUTH.
TIMING AND PHASING OF THE SOUTHERN AND NORTHERN STREAM WILL
CRITICALLY AFFECT THE DURATION OF THE SNOW AND EXPECT THAT THERE
WILL BE A RAPID CUTOFF OF PRECIPITATION EARLY SATURDAY.
SNOWFALL WILL BE HEAVIEST AND WETTER SOUTH OF THE CWFA AND DRIER
NORTH. REGARDLESS EXPECT TO SEE UPWARDS OF 5 INCHES ACROSS MOST OF
THE AREA.
AS THE SYNOPTIC DRIVEN SNOW ENDS...LAKE EFFECT SHOULD CONTINUE IN
LAPORTE...ST. JOSEPH...BERRIEN AND CASS COUNTIES FOR AN ADDITIONAL 2
TO 4 INCHES BY SATURDAY NIGHT EARLY SUNDAY MORNING.
COLDER AND DRIER AIR WILL SETTLE ACROSS THE PLAINS SUNDAY AND WITH
NEW SNOW AND SOME CLEARING...TEMPERATURES SHOULD BOTTOM OUT AGAIN
SUNDAY NIGHT/MONDAY MORNING. WILL BE MAKING SOME DOWNWARD
ADJUSTMENTS TO THE TEMPERATURES FOR SUN/MON PERIOD.
NEXT CLIPPER SYSTEM FORMS IN THE GREAT LAKES REGION MONDAY/MONDAY
NIGHT/TUESDAY AND THIS WILL BRING AN INCREASE OF CLOUDS AND LAKE
EFFECT TO THE AREA. TIMING AND DURATION OF SNOWFALL IS TOO FAR OUT
TO MAKE DEFINITIVE AMOUNT FORECASTS...BUT IT WILL ADD TO THE SNOW
ALREADY ON THE GROUND. AS THAT SYSTEM EXITS...THE COLD AIR RETURNS
IN ITS WAKE. STARTING TO SEE A DECENT SNOW PACK OVER THE NRN
PLAINS...ADDING TO THE DOUBT THAT ANY SIZABLE WARM UP IS COMING OUR
WAY.
NEXT STORY ON THE HORIZON...ECMWF PREDICTION OF DEEP AND EXPLOSIVE
CYCLOGENESIS ACROSS THE NORTHERN AND CENTRAL PLAINS WEDNESDAY NIGHT
INTO THURSDAY. THERE ARE HINTS IN THE OTHER LONG RANGE MODELS OF A
WAVE EJECTING THROUGH THE ROCKIES. THIS WILL HAVE TO BE WATCHED AS
THE PATTERN EVOLVES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 605 PM EST THU DEC 12 2013
LITTLE CHANGE TO PREVIOUS TAFS. VFR CONDITIONS EXPECTED TO
CONTINUE OVERNIGHT AS RIDGE MOVES ACROSS THE AREA. WINDS WILL BACK
TO S-SE FRIDAY AS A LOW PRESSURE SYSTEM MOVES INTO THE SRN PLAINS.
THIS SHOULD CAUSE INCRSG CLOUDINESS DURING THE DAY WITH SOME MVFR
CIGS PSBL TOWARD EVE. ACCUMULATING SNOW ASSOCIATED WITH THIS LOW
IS EXPECTED TO OVERSPREAD NRN INDIANA JUST BEYOND THIS TAF PD ON
FRIDAY EVE WITH IFR CONDITIONS LIKELY OVERNIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 7 PM EST /6 PM CST/ FRIDAY TO 7 PM
EST /6 PM CST/ SATURDAY FOR INZ003>009-012>018-020-022>027-
032>034.
MI...WINTER WEATHER ADVISORY FROM 7 PM FRIDAY TO 7 PM EST SATURDAY
FOR MIZ077>081.
OH...WINTER WEATHER ADVISORY FROM 7 PM FRIDAY TO 7 PM EST SATURDAY
FOR OHZ001-002-004-005-015-016-024-025.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR LMZ043-046.
&&
$$
UPDATE...JT
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...LEWIS
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
625 PM EST THU DEC 12 2013
.SYNOPSIS...
ISSUED AT 330 PM EST THU DEC 12 2013
HIGH PRESSURE WILL BE OVER THE REGION TONIGHT BUT TEMPERATURES
WILL NOT BE AS COLD AS LAST NIGHT. LOWS WILL STILL DROP INTO THE
LOWER AND MIDDLE TEENS...WITH A FEW SINGLE DIGITS POSSIBLE IN
RURAL AREAS. CLOUDS WILL INCREASE FRIDAY AHEAD OF A STRONG LOW
PRESSURE SYSTEM WHICH WILL BRING ACCUMULATING SNOW TO THE REGION
FRIDAY NIGHT AND SATURDAY. CURRENT INDICATIONS ARE THAT
ACCUMULATIONS BETWEEN 2 AND 5 INCHES WILL BE LIKELY.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 323 PM EST THU DEC 12 2013
FEW CONCERNS THROUGH THE SHORT TERM PERIOD AS SIGNIFICANT WEATHER
AHEAD OF NEXT SYSTEM WILL HOLD OFF UNTIL FRIDAY NIGHT.
SATELLITE SHOWING MID AND HIGH CLOUDS EXITING SOUTHERN AREAS THIS
AFTERNOON WHILE THERMAL TROUGH SAGGING ACROSS LAKE MICHIGAN WAS
AIDING IN STRATOCU DEVELOPMENT ACROSS BERRIEN AND CASS COUNTIES IN
MICHIGAN. THESE LOW CLOUDS AND ANY LAKE EFFECT SNOW SHOWERS WILL BE
MAIN CHALLENGE TONIGHT. SYNOPTIC SCALE THERMAL TROUGH ALREADY MOVING
EAST BUT LAKE INDUCED TROUGHINESS AND THERMAL DISPARITY PROGGED TO
ONLY SLOWLY WARM OVERNIGHT. SATELLITE ALREADY SHOWING LAKE CLOUDS
INTO NORTHERN BERRIEN COUNTY DESPITE WARM AIR ADVECTION. HIRES
GUIDANCE SUGGEST TRAJECTORIES AND WEAK LAKE AGGREGATE TROUGH MAY
ALLOW CLOUDS TO STREAM ACROSS MICHIGAN COUNTIES THIS EVENING AND
INTO OVERNIGHT HOURS. PREVIOUS SKY COVER GRIDS HAD THIS TREND
HANDLED WELL AND GENERALLY STAYED WITH SIMILAR IDEA. LIGHT SNOW
SHOWERS ALREADY NEAR OR INTO EXTREME NORTHERN TIP OF BERRIEN COUNTY
SO WILL CARRY SCT FLURRIES OR LIGHT SNOW SHOWERS THROUGH THE EVENING
UNTIL WARMER AIR ARRIVES AND FLOW WEAKENS WHICH COULD LEAD TO WEAK
MESOLOW FORMATION OVER BOWL REGION OF LAKE. LITTLE OR NO
ACCUMULATION EXPECTED GIVEN SHALLOW MOISTURE DEPTH IN OUR AREA.
OTHERWISE EXPECT MOSTLY CLEAR SKIES TO START THE EVENING WITH SOME
MID AND HIGH CLOUDS INCREASING LATE.
NAM MODEL SOUNDINGS QUITE BULLISH ON LOW LEVEL MOISTURE AND STRATUS
DEVELOPMENT FRIDAY MORNING. NAM12 HAS BEEN RATHER
AGGRESSIVE WITH THIS IDEA THIS WINTER WITH SEVERAL INSTANCES SHOWING
THIS WITH LITTLE TO NO DEVELOPMENT. LATEST HRRR GIVES SOME CREDENCE
TO THIS SOLUTION IN THE NORTH NEAR WEAK SURFACE BOUNDARY WHERE WINDS
BECOME LIGHT. HAVE SLOWLY INCREASED CLOUDS ACROSS THE NORTH
AND NORTHWEST WITH POTENTIAL FOR SOME MID AND HIGH CLOUDS AS WELL.
THIS SHOULD KEEP TEMPS FROM FALLING TOO MUCH OVERNIGHT WITH WARM AIR
ADVECTION WELL UNDERWAY. LOOKING FOR LOWS IN THE 10 TO 15 DEGREE
RANGE LATE EVENING WITH STEADY OR EVEN SLOWLY RISING TEMPS LATE WITH
ANY CLOUD COVER DEVELOPMENT.
COL AREA ASSOCIATED WITH WEAK BOUNDARY WILL LIE ACROSS NW FORECAST
AREA FRIDAY WITH GENERALLY LIGHT WINDS. CLOUD COVER REMAINS TRICKY
DEPENDING ON HOW MUCH SATURATION OCCURS NEAR BOUNDARY WITH INVERSION
ALOFT COURTESY OF WARM AIR ADVECTION. HIGHS WILL REACH MID TO UPPER
20S MOST AREAS WITH LOW 30S POSSIBLE FAR SOUTHWEST AHEAD OF NEXT
STRONG SHORT WAVE. BULK OF PCPN WILL HOLD OFF UNTIL FRIDAY EVENING
BUT DID ALLOW A SLIGHT CHANCE TO RESIDE FAR SOUTHWEST AFTER 21Z WITH
PROXIMITY OF INCREASING MOISTURE AND ISENTROPIC LIFT.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 323 PM EST THU DEC 12 2013
...ACCUMULATING SNOWFALL FRIDAY NIGHT-SATURDAY...
PATTERN IS STILL SUPPORTIVE OF FAVORABLE SYNOPTIC SCALE SNOW EVENT
FOR THE REGION BEGINNING LATE FRIDAY NIGHT AND CONTINUING INTO THE
DAY SATURDAY.
NORTHERN STREAM FLOW WILL KEEP THE BOUNDARY LAYER COLD AIR IN PLACE
AND DEEP ENOUGH TO FAVOR ALL SNOW FOR THE EVENT. THE CHALLENGE WILL
BE TIMING THE PHASING OF THE SOUTHERN STREAM AND NORTHERN STREAM
SHORTWAVES ACROSS THE GREAT LAKES.
12Z RUNS ARE GENERALLY CONSISTENT WITH THE SURFACE LOW DEEPENING IN
THE PANHANDLE REGION DURING THE DAY FRIDAY. CONTINUED DEEPENING AND
OF THE SURFACE LOW OVER THE SORUTHERN PLAINS AND LOWER MISSISSIPPI
RIVER VALLEY DURING THE EVENING FRIDAY INTO SATURDAY WILL USHER IN
COPIOUS MOISTURE AND EXPECT TO SEE A PRONOUNCED WARM LAYER SPREADING
NORTHWARD. THIS WILL FAVOR A MORE DENSE AND WET SNOW ACROSS THE
SOUTH.
TIMING AND PHASING OF THE SOUTHERN AND NORTHERN STREAM WILL
CRITICALLY AFFECT THE DURARTION OF THE SNOW AND EXPECT THAT THERE
WILL BE A RAPID CUTOFF OF PRECIPITATION EARLY SATURDAY.
SNOWFALL WILL BE HEAVIEST AND WETTER SOUTH OF THE CWFA AND DRIER
NORTH. REGARDLESS EXPECT TO SEE UPWARDS OF 5 INCHES ACROSS MOST OF
THE AREA.
AS THE SYNOPTIC DRIVEN SNOW ENDS...LAKE EFFECT SHOULD CONTINUE IN
LAPORTE...ST. JOSEPH...BERRIEN AND CASS COUNTIES FOR AN ADDITIONAL 2
TO 4 INCHES BY SATURDAY NIGHT EARLY SUNDAY MORNING.
COLDER AND DRIER AIR WILL SETTLE ACROSS THE PLAINS SUNDAY AND WITH
NEW SNOW AND SOME CLEARING...TEMPERATURES SHOULD BOTTOM OUT AGAIN
SUNDAY NIGHT/MONDAY MORNING. WILL BE MAKING SOME DOWNWARD
ADJUSTMENTS TO THE TEMPERATURES FOR SUN/MON PERIOD.
NEXT CLIPPER SYSTEM FORMS IN THE GREAT LAKES REGION MONNDAY/MONDAY
NIGHT/TUESDAY AND THIS WILL BRING AN INCREASE OF CLOUDS AND LAKE
EFFECT TO THE AREA. TIMING AND DURATION OF SNOWFALL IS TOO FAR OUT
TO MAKE DEFINITIVE AMOUNT FORECASTS...BUT IT WILL ADD TO THE SNOW
ALREADY ON THE GROUND. AS THAT SYSTEM EXITS...THE COLD AIR RETURNS
IN ITS WAKE. STARTING TO SEE A DECENT SNOW PACK OVER THE NRN
PLAINS...ADDING TO THE DOUBT THAT ANY SIZABLE WARMUP IS COMING OUR
WAY.
NEXT STORY ON THE HORIZON...ECMWF PREDICTION OF DEEP AND EXPLOSIVE
CYCLOGENSIS ACROSS THE NORTHERN AND CENTRAL PLAINS WEDNESDAY NIGHT
INTO THURSDAY. THERE ARE HINTS IN THE OTHER LONG RANGE MODELS OF A
WAVE EJECTING THROUGH THE ROCKIES. THIS WILL HAVE TO BE WATCHED AS
THE PATTERN EVOLVES.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 605 PM EST THU DEC 12 2013
LITTLE CHANGE TO PREVIOUS TAFS. VFR CONDITIONS EXPECTED TO
CONTINUE OVERNIGHT AS RIDGE MOVES ACROSS THE AREA. WINDS WILL BACK
TO S-SE FRIDAY AS A LOW PRESSURE SYSTEM MOVES INTO THE SRN PLAINS.
THIS SHOULD CAUSE INCRSG CLOUDINESS DURING THE DAY WITH SOME MVFR
CIGS PSBL TOWARD EVE. ACCUMULATING SNOW ASSOCIATED WITH THIS LOW
IS EXPECTED TO OVERSPREAD NRN INDIANA JUST BEYOND THIS TAF PD ON
FRIDAY EVE WITH IFR CONDITIONS LIKELY OVERNIGHT.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...NONE.
MI...NONE.
OH...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR LMZ043-046.
&&
$$
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...LEWIS
AVIATION...JT
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS GOODLAND KS
609 PM MST THU DEC 12 2013
.UPDATE...
ISSUED AT 605 PM MST THU DEC 12 2013
JUST COMPLETED AN UPDATE. MODELS HAVING A HARD TIME WITH THE SURFACE
WIND FIELD AND DEWPOINTS. WITH THE EXCEPTION OF THE FAR EAST...LOWER
DEWPOINTS COMBINED WITH THE LIGHT WIND FIELD...AS A SURFACE TROUGH
MOVES ACROSS...HAVE ALLOWED TEMPERATURES FALL RATHER RAPIDLY.
LATEST ADJMAV AND RAP ARE HANDLING THE WINDS...DEWPOINTS AND
TEMPERATURES THE BEST. SO USED THOSE COMBINED WITH REALITY TO MAKE
THOSE ADJUSTMENTS. ALSO A LITTLE MORE CLOUD COVER FROM THE SOUTH
MOVING SO ADJUSTED THAT UP SLIGHTLY.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 1154 AM MST THU DEC 12 2013
A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH THE SOUTHERN PLAINS
TONIGHT AND FRIDAY. HOWEVER THE BEST FORCING WILL STAY WELL TO THE
SOUTH AND MOISTURE WILL BE LACKING ANYWAY. THE SURFACE TROUGH IN
EASTERN COLORADO WILL MOVE TO CENTRAL KANSAS BY FRIDAY MORNING
FOLLOWED BY A COLD FRONT AROUND MID DAY. NET RESULT WILL SEE
SURFACE WINDS SHIFTING TO NORTHWEST AND BECOMING BREEZY FRIDAY
AFTERNOON BEHIND THE FRONT. TEMPERATURES WILL BE NEAR
NORMAL...EXCEPT IN THE VERY LIMITED AREAS WHERE LINGERING SNOW
COVER MAY KEEP THEM SLIGHTLY BELOW NORMAL (MAINLY THE OBERLIN TO
MCCOOK AREA).
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 147 PM MST THU DEC 12 2013
FRIDAY NIGHT-MONDAY...SHORTWAVE TROUGH QUICKLY TRANSITIONS EAST
FRIDAY NIGHT AND NORTHWESTERLY FLOW REDEVELOPS OVER THE NORTHERN
PLAINS ALONG WITH RIDGING ACROSS THE SOUTHWESTERN US. OTHER THAN
PASSING MID-HIGH CLOUDS FRIDAY NIGHT AND AGAIN SATURDAY NIGHT WITH
EMBEDDED SHORTWAVE TROUGHS I ANTICIPATE DRY CONDITIONS TO CONTINUE
AS THE STORM TRACK WILL FAVOR LOCATIONS WELL NORTH OF THE CWA AND
A VERY DEEP DRY AIR MASS BELOW 600MB WILL BE SETTLING INTO THE
REGION. A BACKDOOR COLD FRONT WILL KEEP NEAR SEASONAL TEMPS IN
PLACE FRIDAY AND SATURDAY BEFORE TEMPS BEGIN MODERATING ALOFT IN
RESPONSE TO WEST-SOUTHWEST FLOW IN THE LOWER LEVELS OF THE
ATMOSPHERE SUNDAY AND MONDAY. IN RESPONSE TO GOOD WAA I WOULD
EXPECT HIGHS BOTH SUNDAY AND MONDAY TO BE IN THE 50S ACROSS THE
REGION WITH MID 50S ALONG THE CO/KS BORDER (IF NOT HIGHER WITH
GOOD MIXING).
MONDAY NIGHT-WEDNESDAY...FORECAST BECOMES TRICKIER IN THESE PERIODS
AS MODELS HAVE SHOWN LESS CONSISTENCY/CONTINUITY ON TIMING/EVOLUTION
OF TWO STRONG UPPER LEVEL TROUGHS MOVING OUT OF CANADA. THE FIRST
TROUGH SHOULD PASS OVER THE GREAT LAKES REGION MONDAY NIGHT/TUESDAY
TIME FRAME AND GFS IS MUCH STRONGER AND PUSHES A COLD FRONT
SOUTH OVER OUR CWA. ECMWF AND GEM ARE FURTHER NORTH WITH THE INITIAL
TRACK AND HAS CONSISTENTLY SHOW RIDGING ACROSS THE WESTERN US...AND
THE COLD FRONT REMAINING NORTH AND EAST OF OUR CWA. WHILE EITHER
SOLUTION SUPPORTS DRY WEATHER FOR OUR AREA...THERE IS A LARGE SPREAD
IN TEMPERATURES THROUGH THESE PERIODS. BASED ON BETTER CONTINUITY I
TRENDED THE FORECAST FROM THE MODEL CONSENSUS MEAN TOWARDS THE
WARMER ECMWF SOLUTION...WHICH KEEPS ABOVE NORMAL TEMPS IN PLACE
THROUGH WEDNESDAY.
THURSDAY...GEFS/GFS/ECMWF SHOW A LARGE CHANGE IN THE PATTERN AS A
STRONG TROUGH MOVES INTO THE CENTRAL PLAINS AND AN ARCTIC FRONT
DROPS SOUTH OVER OUR CWA. THERE ARE TIMING DIFFERENCES WITH THIS
FRONT...HOWEVER THE OVERALL TREND SHOULD BE THE RETURN OF MUCH
COLDER TEMPS AND THE POSSIBILITY OF ACCUMULATING SNOW BY LATE NEXT
WEEK OR NEXT WEEKEND. BASED ON PAST EXPERIENCE I WOULD NOT BE
SURPRISED IF THE FRONT TIMING IS IN LINE WITH THE FASTER END OF
GUIDANCE AS THE MOMENTUM OF THE VERY COLD/DENSE AIR MASS CARRIES
IT SOUTH ACROSS THE PLAINS AHEAD OF THE MAIN TROUGH THURSDAY.
THERE IS TOO MUCH UNCERTAINTY AT THIS RANGE TO PICK ONE
SOLUTION...SO FOR THIS FORECAST PACKAGE I HAVE SEASONAL HIGHS IN
THE LOW-MID 40S WHICH IS CLOSE TO MODEL MEAN.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 422 PM MST THU DEC 12 2013
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD. WINDS WILL BE
LIGHT AND VARIABLE UNTIL THE MIDDLE OF THE DAY ON FRIDAY. AT THAT
TIME A COLD FRONT WILL MOVE THROUGH AND CAUSE A SHIFT TO INCREASING
NORTH WINDS WHICH WILL BE GUSTY UNTIL LATE IN THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...024
LONG TERM...DR
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1258 PM MST WED DEC 11 2013
.SHORT TERM...(THIS AFTERNOON THROUGH THURSDAY)
ISSUED AT 1258 PM MST WED DEC 11 2013
LATEST WV IMAGERY AND RAP UPPER LEVEL ANALYSIS SHOW NW FLOW STILL IN
PLACE FROM THE NORTHERN ROCKIES AND ACROSS THE CENTRAL PLAINS...WITH
A SHORTWAVE RIDGE ACROSS THE SW US. AT THE SURFACE 1037MB SURFACE
HIGH PRESSURE ENTERED OVER NORTHEASTERN KS AND SOUTHEASTERN NEBRASKA
WITH A LEE TROUGH JUST EAST OF THE FRONT RANGE IN COLORADO. SOUTH TO
SOUTHWEST GRADIENT BETWEEN THESE FEATURES IS IN PLACE OVER OUR
CWA...WHICH HAS SUPPORTED WAA ACROSS WESTERN LOCATIONS AND ABOVE
FREEZING TEMPERATURES ALONG THE CO/KS STATE LINE.
LOW CLOUDS HAVE PRETTY MUCH CLEARED ACROSS ALL BUT THE FAR
NORTHEAST...AND THESE CLOUDS SHOULD CONTINUE TO DISSIPATE AND MOVE
EAST OUT OF THE AREA. WITH SHORTWAVE RIDGING BUILDING NORTH AND EAST
WE WILL SEE DRY CONDITIONS PERSIST. THE MAIN FORECAST CHALLENGE
THROUGH THE SHORT TERM WILL BE HOW WARM TO MAKE TEMPS. AIR MASS WILL
CONTINUE TO MODERATE WITH SW FLOW SUPPORTING GOOD WAA. MODELS SHOW
H85 TEMPS IN THE 5-7C RANGE...WHICH IF THE GOOD MIXING/WARMING
OBSERVED THE LAST FEW DAYS IS ANY INDICATION WE SHOULD SEE HIGHS AT
LEAST IN THE LOW 50S OVER SNOW FREE AREAS. WITH SW WINDS ADVECTING
THESE WARMER TEMPS TOWARDS SNOW COVERED LOCATIONS IN OUR FAR WEST
AND NORTHEAST WE SHOULD SEE CONTINUED DETERIORATION OF THE SNOW
PACK. I AM NOT AS CONFIDENT ABOUT HIGH TEMP ON THURSDAY OVER
MCCOOK/ATWOOD/OBERLIN...BECAUSE OF THIS SNOW PACK. I WOULD NOT BE
SURPRISED IF AFTER TOMORROW THERE IS NO SIGNIFICANT SNOW PACK LEFT
OVER OUR CWA EVEN IN LOCATIONS THAT SAW 4-5" IN THE NORTHEAST.
.LONG TERM...(THURSDAY NIGHT THROUGH NEXT WEDNESDAY)
ISSUED AT 1209 PM MST WED DEC 11 2013
SHORTWAVE TROUGH WILL MOVE ACROSS THE SOUTHERN PLAINS THURSDAY
NIGHT AND FRIDAY. THE SYSTEM WILL BE TOO FAR SOUTH TO BRING A
CHANCE OF PRECIPITATION TO THE LOCAL AREA...HOWEVER IT WILL TAP
INTO SOME SLIGHTLY COOLER AIR FOR FRIDAY AND SATURDAY...WITH
TEMPERATURES 5 TO 10 DEGREES BELOW NORMAL. THE REMAINDER OF THE
LONG TERM PERIOD WILL SEE VARYING DEGREES OF NORTHWEST FLOW ALOFT.
NO PRECIPITATION IS EXPECTED. TEMPERATURES WILL BE MILD WITH HIGHS
MAINLY IN THE 50S THOUGH COULD REACH THE 60S AND POSSIBLY EVEN 70S
IN A FEW LOCATIONS TUESDAY AND WEDNESDAY WITH DOWNSLOPE WARMING.
HOWEVER...ANOTHER ARCTIC OUTBREAK IS LOOMING FOR THE END OF THE
WEEK WITH BITTERLY COLD AIR MASS UPSTREAM WHICH WILL ARRIVE JUST
BEYOND THIS FORECAST PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY)
ISSUED AT 1023 AM MST WED DEC 11 2013
LOW STRATUS HAS OVERSPREAD BOTH TERMINALS THIS MORNING WITH IFR
CIGS AT KGLD AND MVFR CIGS AT KMCK. SHORT RANGE GUIDANCE GENERALLY
SUPPORTS THIS ACTIVITY DISSIPATING EARLY THIS AFTERNOON AS SW FLOW
BRING DRY AIR BACK INTO THE LOWER ATMOSPHERE. SATELLITE TRENDS
ALREADY INDICATE EDGES OF STRATUS ERODING AND AN OVERALL THINNING
OF THE CLOUD LAYER. I KEPT CIGS PREVAILING THROUGH 20Z BASED ON
SIMILAR TIMING OF RAP/HRRR WITH VFR CONDITIONS THEN PREVAILING
THROUGH THE REST OF THE TAF PERIOD. AS SKIES CLEAR AND DAYTIME
MIXING INCREASE WE SHOULD SEE SOUTH WINDS GUSTING IN THE 20-25KT
RANGE AT KGLD. I HAVE LESS CONFIDENCE IN WINDS MIXING TO THE
SURFACE AT KMCK. BY TONIGHT WINDS SHOULD DECREASE BELOW 12KT AT
BOTH TERMINALS AND REMAIN BELOW 12KT THROUGH THE REST OF THE TAF
PERIOD.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...DR
AREA FORECAST DISCUSSION
NWS GOODLAND KS
956 PM MST TUE DEC 10 2013
.SHORT TERM...(TONIGHT AND TOMORROW)
ISSUED AT 1206 PM MST TUE DEC 10 2013
LATEST WV IMAGERY AND RAP H5 UPPER LEVEL ANALYSIS INDICATES NW FLOW
EXTENDING FROM THE THE NORTHERN ROCKIES IN CANADA ACROSS THE GREAT
BASIN AND INTO THE WESTERN PLAINS OF KANSAS. MID-UPPER LEVEL
MOISTURE PLUME ON WV ASSOCIATED WITH MID-HIGH CLOUDS ARE MOVING INTO
THE NEBRASKA PANHANDLE. THIS APPEARS TO BE ALONG THE LEADING EDE OF
AN EMBEDDED SHORTWAVE TROUGH MOVING OUT OF CANADA INTO THE NORTHERN
PLAINS. AT THE SURFACE A WEAK LEE TROUGH HAS DEVELOPED JUST EAST OF
THE FRONT RANGE IN COLORADO WITH A SURFACE TROUGH AXIS EXTENDING
NORTH ACROSS THE NEBRASKA PANHANDLE. SOUTHERLY GRADIENT EXTENDS EAST
ACROSS WESTERN KANSAS AND HAS SUPPORTED GOOD WAA AND MIXING ACROSS
OUR CWA WHERE TEMPS HAVE FINALLY RISEN ABOVE FREEZING FOR THE FIRST
TIME IN 6 DAYS.
DUE TO SNOW PACK BETTER SNOW PACK IN NE PARTS OF OUR CWA MIXING HAS
BEEN LIMITED AND TEMPS HAVE STRUGGLED TO APPROACH FREEZING. THROUGH
THE REST OF THE AFTERNOON WE SHOULD SEE FURTHER DETERIORATION OF
SNOW PACK ACROSS OUR CWA...SO THERE SHOULD BE LESS OF AN IMPACT ON
THE FORECAST FOR MOST OF OUR AREA GOING FORWARD.
TONIGHT...THE SHORTWAVE TROUGH OVER MONTANA WILL SWING SOUTH THEN
EAST ACROSS THE NORTHERN PLAINS PUSHING A BACKDOOR COLD FRONT OVER
OUR CWA. THERE WILL BE SOME WEAK FORCING ACROSS THE NORTHERN PART OF
OUR CWA...HOWEVER WITH A VERY DRY AIR MASS BELOW 12-15KFT I AM NOT
ANTICIPATING ANY MEASURABLE PRECIP. COULDNT RULE OUT A FEW FLURRIES
IN SW NEBRASKA...HOWEVER ITS HARD TO SAY IF THIS WOULD EVEN REACH
THE SURFACE. WITH A COLD AIR SLOSHING BACK OVER OUR CWA TEMPS WILL
COOL OFF ONCE AGAIN...WITH OVERNIGHT LOWS IN THE SINGLE DIGITS.
WINDS AROUND 10-12KTS...CLOUD COVER...AND SLIGHTLY HIGHER SURFACE TD
VALUES SHOULD LIMIT RADIATIONAL COOLING...OTHERWISE WE WOULD HAVE
SEEN ANOTHER NIGHT OF BELOW ZERO TEMPS.
WEDNESDAY...WHILE THE AIR ALOFT WILL BE COOLER THE PATTERN ALOFT
WILL BE MUCH MORE PROGRESSIVE WITH SHORTWAVE RIDGING AND SOUTHERLY
FLOW REDEVELOPING BY LATE AFTERNOON. HIGH TEMPS ARE TRICKY SINCE WE
COULD SEE A GRADIENT OF MID 30S IN THE WEST ASSOCIATED WITH
AFTERNOON WAA AND GOOD MIXING TO MID 20S IN THE NORTHEAST WHERE
COOLER AIR WILL STILL BE IN PLACE.
.LONG TERM...(TOMORROW NIGHT THROUGH NEXT TUESDAY)
ISSUED AT 1206 PM MST TUE DEC 10 2013
THE CENTRAL PLAINS WILL BE UNDER VARYING DEGREES OF NORTHWEST FLOW
ALOFT THROUGH THE ENTIRE PERIOD. NO SIGNIFICANT DISTURBANCES ARE
FORECAST AND DRY CONDITIONS ARE EXPECTED. TEMPERATURES WILL
GENERALLY BE NEAR NORMAL...ALTHOUGH A COUPLE OF BRIEF COLD AIR
INTRUSIONS ARE FORECAST BY THE MODELS. THE FIRST WILL OCCUR FRIDAY
NIGHT AND WILL LOWER TEMPERATURES BY 5-10 DEGREES ON SATURDAY. A
SECOND SHOT OF EVEN COLDER AIR WILL EFFECT MAINLY EASTERN PARTS OF
THE FORECAST AREA ON SUNDAY. MODELS DISAGREE ON HOW FAR WEST TO
BRING THAT SHALLOW AIR MASS THOUGH THE COLD AIR USUALLY WINS IN
THESE SITUATIONS AND HAVE HEDGED TEMPERATURES ON THE COLD SIDE OF
GUIDANCE ESPECIALLY IN THE EAST. BY MONDAY ALL MODELS SHOW THE COLD
AIR SCOURED OUT AND TEMPERATURES REBOUNDING. ANOTHER SLIGHTLY
COOLER GLANCING BLOW MAY OCCUR ON TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 955 PM MST TUE DEC 10 2013
VFR CONDITIONS ARE LIKELY THROUGH THE ENTIRE 24 FORECAST PERIOD.
POST-FRONTAL NORTHERLY WINDS AT AROUND 10-12 KNOTS SHOULD
DECREASE GRADUALLY OVERNIGHT. BY EARLY MORNING...SURFACE HIGH
PRESSURE MOVES SOUTHEASTWARD JUST TO THE EAST OF BOTH TERMINALS
RESULTING IN LIGHT WINDS. BY MID DAY A SOUTHWESTERLY WIND WILL
STRENGTHEN...POSSIBLY GUSTING TO NEAR 20 KNOTS DURING THE
AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
SHORT TERM...DR
LONG TERM...024
AVIATION...BRB
AREA FORECAST DISCUSSION
NWS GRAY ME
303 PM EST WED DEC 11 2013
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH THROUGH THE REGION TONIGHT. A WEAK
RIDGE OF HIGH PRESSURE WILL BUILD IN FROM THE WEST ON THURSDAY.
LOW PRESSURE MOVING EAST THROUGH SOUTHERN QUEBEC THURSDAY NIGHT
WILL SWING A TRAILING COLD FRONT THROUGH THE REGION ON FRIDAY.
HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST FRIDAY NIGHT AND
SATURDAY. LOW PRESSURE OVER THE OHIO VALLEY SATURDAY NIGHT WILL
REDEVELOP OFF THE MID ATLANTIC COAST AND WILL MOVE NORTHEAST OFF
THE NEW ENGLAND COAST ON SUNDAY. LOW PRESSURE WILL CONTINUE
NORTHEAST INTO THE MARITIMES SUNDAY NIGHT. HIGH PRESSURE WILL
BUILD IN FROM THE WEST ON MONDAY THEN SHIFT OFFSHORE ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
INTERESTING TO NOTE...LAKE EFFECT SNOW SHOWERS WILL LIKELY CONTINUE
ACROSS NORTH-CENTRAL NEW HAMPSHIRE. THIS IS DUE TO THE LARGE BAND
EXITING OFF LAKE ONTARIO. THE LATEST HRRR RUN PICKS UP ON THIS
BAND DURING THE EVENING HOURS...BEFORE WEAKENING IT AND MOVING IT
TO THE SOUTH. ANOTHER BAND OF SNOW SHOWERS ASSOCIATED WITH THE
ARCTIC FRONT WILL LIKELY ENTER MAINE FROM CANADA AROUND 23Z.
ISOLATED SQUALLS ARE POSSIBLE WITH THIS ACTIVE SYSTEM AND WILL
NEED TO BE MONITORED CLOSELY THIS EVENING.
THE MUCH ANTICIPATED ARCTIC FRONT WILL FINALLY CROSS THE REGION
TONIGHT...BRING VERY COLD TEMPERATURES. WITH A NORTHWEST
BREEZE...FAR NORTHERN AREAS WILL RECEIVE WIND CHILL ADVISORY
CONDITIONS IN THE -20C AND COLDER RANGE. THUS...WILL BE POSTING
ADVISORIES FOR THE NORTHERN MOUNTAINS THROUGH EARLY THURSDAY MORNING.
OTHERWISE...UPSLOPE SNOW SHOWERS WILL LIKELY LEAD TO ACCUMULATING
SNOWFALL ACROSS THE HIGHER NORTHWEST FACING TERRAIN TONIGHT. LOOK
FOR UP TO 2-4 INCHES OF DRY...POWDERY SNOW IN THIS REGION.
TEMPERATURES WILL FALL TO NEAR ZERO IN THE NORTH WITH THE
CONTINUING NORTHWEST WIND.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
A WEAK RIDGE OF HIGH PRESSURE WILL PARK ITSELF OVER NORTHERN NEW
ENGLAND THURSDAY. HOWEVER...CLOUDS WILL BE ON THE INCREASE ONCE
AGAIN DURING THE AFTERNOON IN THE NORTH AND MOUNTAINS AS ANOTHER
CLIPPER TYPE SYSTEM QUICKLY APPROACHES FROM CANADA.
THURSDAY NIGHT WILL BE ALMOST A CARBON COPY OF TONIGHT...WITH
SCATTERED SNOW SHOWERS ALONG THE FRONT BY THE EARLY MORNING HOURS.
MORE UPSLOPE SNOW SHOWERS WILL LIKELY FOLLOW. THIS NEXT SHOT OF
COLD AIR WILL BE JUST AS COLD...IF NOT COLDER...THAN THE FIRST
SHOT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
WEAK TROUGH MOVING THROUGH THE REGION FRIDAY WILL LIKELY ONLY
RESULT IN SOME SNOW SHOWERS OVER THE MOUNTAINS. HIGH PRESSURE
MOVES IN FROM THE NORTH FRIDAY NIGHT AND SATURDAY...BRINGING MUCH
COLDER TEMPERATURES TO THE REGION. THIS WILL SET THE STAGE FOR A
POSSIBLE STORM SATURDAY NIGHT AND SUNDAY.
MODELS ARE INDICATING A COASTAL LOW DEVELOPING OVER THE MID-
ATLANTIC STATES SATURDAY NIGHT AND ACROSS THE GULF OF MAINE ON
SUNDAY. THE 12Z GFS HAS BEEN FURTHER EAST WITH THIS SYSTEM AND
TAKES THE LOW OUTSIDE OF THE BENCHMARK...WHILE THE 12Z EURO IS
TAKING THE LOW ALMOST DIRECTLY OVER THE BENCHMARK. EVEN
STILL...THE TREND IN THE EURO HAS BEEN FURTHER EAST WITH EACH RUN.
EVEN IF THE SYSTEM REMAINS WELL OFFSHORE THERE COULD BE ENOUGH
WRAP AROUND MOISTURE TO PRODUCE SEVERAL INCHES OF SNOW OVER
SOUTHERN MAINE AND NEW HAMPSHIRE. COLD AIR ENTRENCHED AT THE
SURFACE SHOULD ENSURE THAT THIS WILL BE AN ALL SNOW EVENT WITH
NOTHING IN THE WAY OF ICE OR RAIN. THE EURO IS ALSO INDICATING
ANOTHER COMPLICATING FACTOR...THE EMERGENCE OF AN INVERTED TROUGH
EXTENDING FROM THE GULF OF MAINE BACK ACROSS LAKE ONTARIO. WILL
DEFINITELY NEED TO WATCH THIS SYSTEM AS WE MOVE INTO THE WEEKEND.
ONCE THE LOW CLEARS THE REGION LATE SUNDAY...RELATIVELY QUIET
WEATHER WILL DOMINATE THE REMAINDER OF THE FORECAST PERIOD.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM...VFR TONIGHT WITH AREAS OF MVFR CEILINGS AND VSBY
POSSIBLE IN THE MOUNTAINS IN ANY SNOW SHOWERS. VFR THURSDAY AND
THURSDAY NIGHT.
LONG TERM...MAINLY VFR FRIDAY AND SATURDAY. IFR/LIFR CIGS AND
VSBYS WILL DEVELOP SATURDAY NIGHT AND SUNDAY AS STRONG SYSTEM
MOVES THROUGH THE REGION.
&&
.MARINE...
SHORT TERM...MINIMAL GALES WILL CONTINUE FOR THE OUTER WATERS FOR
TONIGHT WITH SCAS IN THE BAYS.
LONG TERM...WILL LIKELY NEED AT LEAST SMALL CRAFT ADVISORIES FOR
SATURDAY AND SUNDAY AS LOW PRESSURE TRACKS THROUGH THE GULF OF MAINE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 1 AM TO 8 AM EST THURSDAY FOR
MEZ007>009.
NH...WIND CHILL ADVISORY FROM 1 AM TO 8 AM EST THURSDAY FOR NHZ001.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR ANZ151-153.
GALE WARNING UNTIL 1 AM EST THURSDAY FOR ANZ150-152-154.
&&
$$
CANNON/POHL
AREA FORECAST DISCUSSION
NWS GRAY ME
302 PM EST WED DEC 11 2013
.SYNOPSIS...
A COLD FRONT WILL DROP SOUTH THROUGH THE REGION TONIGHT. A WEAK
RIDGE OF HIGH PRESSURE WILL BUILD IN FROM THE WEST ON THURSDAY.
LOW PRESSURE MOVING EAST THROUGH SOUTHERN QUEBEC THURSDAY NIGHT
WILL SWING A TRAILING COLD FRONT THROUGH THE REGION ON FRIDAY.
HIGH PRESSURE WILL BUILD IN FROM THE NORTHWEST FRIDAY NIGHT AND
SATURDAY. LOW PRESSURE OVER THE OHIO VALLEY SATURDAY NIGHT WILL
REDEVELOP OFF THE MID ATLANTIC COAST AND WILL MOVE NORTHEAST OFF
THE NEW ENGLAND COAST ON SUNDAY. LOW PRESSURE WILL CONTINUE
NORTHEAST INTO THE MARITIMES SUNDAY NIGHT. HIGH PRESSURE WILL
BUILD IN FROM THE WEST ON MONDAY THEN SHIFT OFFSHORE ON TUESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
INTERESTING TO NOTE...LAKE EFFECT SNOW SHOWERS WILL LIKELY CONTINUE
ACROSS NORTH-CENTRAL NEW HAMPSHIRE. THIS IS DUE TO THE LARGE BAND
EXITING OFF LAKE ONTARIO. THE LATEST HRRR RUN PICKS UP ON THIS
BAND DURING THE EVENING HOURS...BEFORE WEAKENING IT AND MOVING IT
TO THE SOUTH. ANOTHER BAND OF SNOW SHOWERS ASSOCIATED WITH THE
ARCTIC FRONT WILL LIKELY ENTER MAINE FROM CANADA AROUND 23Z.
ISOLATED SQUALLS ARE POSSIBLE WITH THIS ACTIVE SYSTEM AND WILL
NEED TO BE MONITORED CLOSELY THIS EVENING.
THE MUCH ANTICIPATED ARCTIC FRONT WILL FINALLY CROSS THE REGION
TONIGHT...BRING VERY COLD TEMPERATURES. WITH A NORTHWEST
BREEZE...FAR NORTHERN AREAS WILL RECEIVE WIND CHILL ADVISORY
CONDITIONS IN THE -20C AND COLDER RANGE. THUS...WILL BE POSTING
ADVISORIES FOR THE NORTHERN MOUNTAINS THROUGH EARLY THURSDAY MORNING.
OTHERWISE...UPSLOPE SNOW SHOWERS WILL LIKELY LEAD TO ACCUMULATING
SNOWFALL ACROSS THE HIGHER NORTHWEST FACING TERRAIN TONIGHT. LOOK
FOR UP TO 2-4 INCHES OF DRY...POWDERY SNOW IN THIS REGION.
TEMPERATURES WILL FALL TO NEAR ZERO IN THE NORTH WITH THE
CONTINUING NORTHWEST WIND.
&&
.SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/...
A WEAK RIDGE OF HIGH PRESSURE WILL PARK ITSELF OVER NORTHERN NEW
ENGLAND THURSDAY. HOWEVER...CLOUDS WILL BE ON THE INCREASE ONCE
AGAIN DURING THE AFTERNOON IN THE NORTH AND MOUNTAINS AS ANOTHER
CLIPPER TYPE SYSTEM QUICKLY APPROACHES FROM CANADA.
THURSDAY NIGHT WILL BE ALMOST A CARBON COPY OF TONIGHT...WITH
SCATTERED SNOW SHOWERS ALONG THE FRONT BY THE EARLY MORNING HOURS.
MORE UPSLOPE SNOW SHOWERS WILL LIKELY FOLLOW. THIS NEXT SHOT OF
COLD AIR WILL BE JUST AS COLD...IF NOT COLDER...THAN THE FIRST
SHOT.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
WEAK TROUGH MOVING THROUGH THE REGION FRIDAY WILL LIKELY ONLY
RESULT IN SOME SNOW SHOWERS OVER THE MOUNTAINS. HIGH PRESSURE
MOVES IN FROM THE NORTH FRIDAY NIGHT AND SATURDAY...BRINGING MUCH
COLDER TEMPERATURES TO THE REGION. THIS WILL SET THE STAGE FOR A
POSSIBLE STORM SATURDAY NIGHT AND SUNDAY.
MODELS ARE INDICATING A COASTAL LOW DEVELOPING OVER THE MID-
ATLANTIC STATES SATURDAY NIGHT AND ACROSS THE GULF OF MAINE ON
SUNDAY. THE 12Z GFS HAS BEEN FURTHER EAST WITH THIS SYSTEM AND
TAKES THE LOW OUTSIDE OF THE BENCHMARK...WHILE THE 12Z EURO IS
TAKING THE LOW ALMOST DIRECTLY OVER THE BENCHMARK. EVEN
STILL...THE TREND IN THE EURO HAS BEEN FURTHER EAST WITH EACH RUN.
EVEN IF THE SYSTEM REMAINS WELL OFFSHORE THERE COULD BE ENOUGH
WRAP AROUND MOISTURE TO PRODUCE SEVERAL INCHES OF SNOW OVER
SOUTHERN MAINE AND NEW HAMPSHIRE. COLD AIR ENTRENCHED AT THE
SURFACE SHOULD ENSURE THAT THIS WILL BE AN ALL SNOW EVENT WITH
NOTHING IN THE WAY OF ICE OR RAIN. THE EURO IS ALSO INDICATING
ANOTHER COMPLICATING FACTOR...THE EMERGENCE OF AN INVERTED TROUGH
EXTENDING FROM THE GULF OF MAINE BACK ACROSS LAKE ONTARIO. WILL
DEFINITELY NEED TO WATCH THIS SYSTEM AS WE MOVE INTO THE WEEKEND.
ONCE THE LOW CLEARS THE REGION LATE SUNDAY...RELATIVELY QUIET
WEATHER WILL DOMINATE THE REMAINDER OF THE FORECAST PERIOD.
&&
.AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
SHORT TERM...VFR TONIGHT WITH AREAS OF MVFR CEILINGS AND VSBY
POSSIBLE IN THE MOUNTAINS IN ANY SNOW SHOWERS. VFR THURSDAY AND
THURSDAY NIGHT.
LONG TERM...MAINLY VFR FRIDAY AND SATURDAY. IFR/LIFR CIGS AND
VSBYS WILL DEVELOP SATURDAY NIGHT AND SUNDAY AS STRONG SYSTEM
MOVES THROUGH THE REGION.
&&
.MARINE...
SHORT TERM...MINIMAL GALES WILL CONTINUE FOR THE OUTER WATERS FOR
TONIGHT WITH SCAS IN THE BAYS.
LONG TERM...WILL LIKELY NEED AT LEAST SMALL CRAFT ADVISORIES FOR
SATURDAY AND SUNDAY AS LOW PRESSURE TRACKS THROUGH THE GULF OF MAINE.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 1 AM TO 8 AM EST THURSDAY FOR
MEZ007>009.
NH...WIND CHILL ADVISORY FROM 1 AM TO 8 AM EST THURSDAY FOR NHZ001.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 AM EST THURSDAY FOR ANZ151-153.
GALE WARNING UNTIL 1 AM EST THURSDAY FOR ANZ150-152-154.
&&
$$
CANNON/POHL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
943 PM EST THU DEC 12 2013
.UPDATE...
ISSUED AT 942 PM EST THU DEC 12 2013
MAIN FCST CONCERN THIS EVNG HAS BEEN ON TIMING/IMPACT OF INTENSE LES
BAND SHOWN ON MQT 88D OVER SCENTRAL LK SUP EXTENDING INTO FAR ERN
ALGER/NRN LUCE COUNTIES. THIS BAND HAS BEEN NEARLY STNRY THRU MUCH
OF THE EVNG...WITH HIEST REFLECTIVITIES APRCHG 30 DBZ AS HI AS 6-7K
FT...PROMPTING ISSUANCE OF AN SPS EARLIER IN THE EVNG. CALL TO
SPOTTER JUST S OF GRAND MARAIS INDICATED SN FALLING AT THE RATE OF
AN INCH/HR WITH TOTAL ACCUMULATION FM NOON THRU 9 PM ARND 7 INCHES.
THE BAND INTENSIFIED DURING THE EVNG WITH SHARPENING LLVL CNVGC
ACCOMPANYING MORE PRONOUNCED LAND BREEZE SW WIND COMPONENT ON THE
SRN FLANK OF THE BAND. CONSIDERED UPGRADING ADVY TO WRNG TO THIS
AREA...BUT RECENT RADAR IMAGERY INDICATES THE BAND IS BEGINNING TO
SHIFT TO THE S IN LINE WITH VEERING LLVL WINDS TO THE NW...WHICH IS
IN AGREEMENT WITH HIER RES MODEL FCSTS. IN FACT...NEARBY SFC OBS/MQD
88D VWP DO SHOW A VEERING TREND. WITH THE STEADY VEERING EXPECTED
THRU THE NGT AND FCST WEAKENING LAND BREEZE CNVGC...EXPECT THE BAND
TO MOVE MORE STEADILY AND DIMINISH A BIT WITH TIME. WITH WEAKER
MULTIPLE BANDED LES EXPECTED TO DOMINATE...WL HOLD ON TO GOING ADVY
FOR ALGER/LUCE/NRN SCHOOLCRAFT COUNTIES.
OTRW...TENDED TO BUMP UP MIN TEMPS FCST A FEW DEGREES WITH QUITE A
BIT OF CLD COVER AND WSHFT TO A MORE N DIRECTION ALLOWING FOR MORE
LK SUP MODERATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
ACROSS ERN NOAM RESULTING IN NW FLOW THROUGH THE NRN GREAT LAKES. A
SHORTWAVE TROUGH WAS MOVING THROUGH NW ONTARIO DRAGGING A COLD FRONT
THROUGH WRN LAKE SUPERIOR. FARTHER UPSTREAM...A WEAK CLIPPER SHRTWV
WAS MOVING FROM SRN SASK INTO THE NRN PLAINS. LES BANDS ALIGNED WITH
WNW FLOW THROUGH ERN LAKE SUPERIOR INTO NE ALGER AND NRN LUCE
COUNTIES HAD DIMINISHED SLIGHTLY AND BECOME MORE CELLULAR THIS
AFTERNOON WITH WEAKENING LOW LEVEL CONV FROM LAND BREEZE COMPONENT.
EXPECT THAT THE LOW LEVEL WINDS WILL DIMINISH AND VEER FROM WNW TO
NRLY. THIS SHOULD PUSH THE MORE SIGNIFICANT LES THROUGH MUCH OF THE
ERN CWA FROM ALGER COUNTY EASTWARD AS A STRENGTHENING LAND BREEZE
SHOULD KEEP MOST OF THE SNOW EAST OF MARQUETTE. EVEN WITH THE
SHIFTING POSITION OF THE LES BANDS...FAVORABLE SNOW GROWTH WITH THE
DGZ IN THE 1K-4K CONVECTIVE LAYER PUSHING SLR VALUES ABOVE 25/1 AND
SHOULD SUPPORT ADVISORY SNOWFALL AMOUNTS IN THE 3 TO 6 INCH RANGE.
OVER THE WEST...THE SHORTER FETCH...ACYC FLOW AND LOWER INVERSION
HEIGHTS FROM 3K-4K FT...WILL KEEP SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE.
FROM LATE TONIGHT INTO EARLY FRI...THE SASK SHRTWV AND WEAK UPPER
LEVEL DIV WITH THE RIGHT ENTRANCE OF A 140 KT 250-300 MB JET WITH
ASSOCIATED 800-600 MB FGEN MAY SUPPORT A BAND OF LIGHT SNOW.
HOWEVER...MODELS SUGGEST THAT THE BEST CHANCE OF LIGHT SNOW WITH
THESE FEATURES WILL REMAIN OVER WI. SO...ONLY CHANCE POPS WITH
ACCUMULATIONS LESS THAN A HALF INCH WERE INCLUDED.
WINDS WILL CONTINUE TO VEER FRIDAY AS ARCTIC HIGH PRES FROM
SASK/MANITOBA INTO NRN ONTARIO BUILDS INTO THE NRN LAKES. WITH WINDS
SHIFTING FROM N TO NNE THE MOST FAVORABLE LOW LEVEL CONV WILL SHIFT
FROM THE NE CWA INTO MARQUETTE COUNTY. WHILE SNOW GROWTH WILL REMAIN
FAVORABLE...INVERSION HEIGHT REMAINING NEAR 5K-6K FT WITH MAINLY
ACYC UPSTREAM FLOW MAY LIMIT LES INTENSITY AND SNOWFALL AMOUNTS
BELOW ADVY LEVELS. GENERALLY 1 TO 3 INCHES ARE EXPECTED WITH THE
GREATEST AMOUNTS IN FAR WRN ALGER COUNTY INTO ERN MARQUETTE COUNTY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
MODELS TODAY CONTINUE TO INDICATE AN OVERALL COLD PATTERN THRU THE
LONG TERM PORTION OF THE FCST. HOWEVER...WITH CURRENT DEEP EXPANSIVE
POLAR VORTEX CENTERED AROUND HUDSON BAY STILL FCST TO WEAKEN AND
RETREAT N THRU AT LEAST THE MIDDLE OF NEXT WEEK...THE COLD WILL EASE
SOME. A VAST SUPPLY OF COLD AIR WILL REMAIN ACROSS CANADA...SO ANY
SHORTWAVE TRACKING ALONG IN THE RELAXING NW FLOW PATTERN WILL BE
ABLE TO TUG COLDER AIR INTO THE UPPER LAKES. FOR THIS REASON...
MEDIUM RANGE GUIDANCE FOR SEVERAL DAYS HAS BEEN PROGRESSIVELY SLOWER
TO BRING WARMING INTO THE UPPER LAKES AND HAS ALSO BEEN MORE
TEMPERED WITH THE WARMING. AROUND THE MIDDLE OF NEXT WEEK THERE WILL
BE A TEMPORARY SHIFT IN THE PATTERN TOWARD A DEEPENING TROF OVER THE
WRN CONUS AND DOWNSTREAM BUILDING RIDGE OVER THE SE CONUS/WRN
ATLANTIC. THUS THE MIDWEEK PERIOD WILL OFFER THE BEST CHANCE OF A
WARMUP. HOW MUCH WARMING OCCURS WILL DEPEND ON THE AMPLITUDE AND
LONGITUDE OF THE TROF/RIDGE PATTERN. LATEST MODEL TRENDS POINT
TOWARD AN EWD SHIFT IN THE TROF/RIDGE PATTERN WHICH WILL LIMIT
WARMING FOR THE UPPER LAKES. IN ANY CASE...WARMING WILL ONLY BE
BRIEF AS LONGER RANGE GUIDANCE CONTINUES TO POINT TOWARD
REINTENSIFYING ARCTIC AIR ACROSS WRN/NRN CANADA DUMPING BACK INTO
THE AREA SOMETIME AROUND THE WEEKEND BEFORE CHRISTMAS. OUTSIDE OF
AREAS AFFECTED BY LES/LAKE ENHANCEMENT...THERE WON`T BE MUCH MORE
THAN SOME -SN AT TIMES DURING THE LONG TERM. THE RESURGENCE OF
ARCTIC AIR S INTO THE CONUS LATE NEXT WEEK/WEEKEND COULD OFFER THE
POTENTIAL FOR SOMETHING MORE SUBSTANTIAL IN TERMS OF WIDESPREAD
SNOWFALL.
BEGINNING FRI NIGHT...WINDS WILL CONTINUE VEERING TO THE E THEN
SE FRI NIGHT/SAT MORNING AS SFC HIGH PRES CENTER PASSES JUST N OF
LAKE SUPERIOR AND NEXT CLIPPER SHORTWAVE APPROACHES FROM THE NW. LES
THAT WILL BE OCCURRING MAINLY INTO NCNTRL UPPER MI THU AFTN WILL
SLOWLY SHIFT OUT OF NCNTRL UPPER MI AND THEN CROSS THE KEWEENAW
PENINSULA FOR A TIME LATE FRI NIGHT/SAT MORNING. DGZ WILL BE WELL
CENTERED IN THE CONVECTIVE LAYER...SO A FEW INCHES OF FLUFFY SNOW
ARE POSSIBLE IN THIS AREA OF LES THAT WILL BE SHIFTING WITH THE
WINDS. ALSO...WITH WINDS VEERING OVER NRN LAKE MI...LES OFF LAKE MI
WILL LIKELY MOVE INTO MENOMINEE COUNTY AND POSSIBLY DELTA COUNTY...
LEADING TO SOME FLUFFY SNOW ACCUMULATIONS LATE FRI NIGHT/SAT
MORNING.
ATTENTION THEN TURNS TO NEXT CLIPPER SHORTWAVE DROPPING THRU THE
UPPER GREAT LAKES SAT NIGHT/SUN. -SN ASSOCIATED WITH FEATURE SHOULD
SPREAD INTO THE AREA SAT AFTN/EVENING...AND IT LOOKS LIKE THERE WILL
BE A PERIOD OF LAKE ENHANCEMENT OFF LAKE MI IN SOUTHERLY FLOW...
LEADING TO A POTENTIAL ADVY EVENT. A BRIEF SHOT OF ARCTIC AIR
FOLLOWING SYSTEM WILL PROBABLY RESULT IN A SHORT DURATION PERIOD OF
MDT TO POSSIBLY HVY LAKE ENHANCED SNOW FOR NORTHWEST AND NORTHEAST
UPPER MI LATE SAT NIGHT/EARLY SUNDAY AS WIND SHIFTS NW. SINCE DEEP
LAYER FORCING WITH SHORTWAVE IS FAIRLY IMPRESSIVE...WILL NEED TO
WATCH FOR LOCALLY HVY LAKE ENHANCED SNOW OFF LAKE MI AHEAD OF WAVE
AND OFF LAKE SUPERIOR AS THE WAVE PASSES. AS WINDS VEER AROUND TO
THE N OR NE WITH SFC HIGH PRES PASSING ACROSS NRN ONTARIO...LIGHTER
LES WILL AGAIN SHIFT TO AFFECT MORE OF NRN UPPER MI SUN
AFTN/EVENING.
OVER THE LAST FEW DAYS...UNCERTAINTY FOR THE EARLY AND MIDDLE PARTS
OF NEXT WEEK HAS BEEN HIGH WITH REGARD TO TIMING/STRENGTH/TRACK OF
SEVERAL SHORTWAVES IN WNW FLOW. IT APPEARS THERE MAY BE A COUPLE OF
PERIODS OF WIDESPREAD -SN (CONFIDENCE HIGHEST FOR -SN ON MON) AS
WELL AS LAKE ENHANCEMENT OFF LAKE MICHIGAN AND LAKE SUPERIOR
DEPENDING ON WIND DIRECTION IMMEDIATELY PRIOR TO AND AFTER PASSAGE
OF THE WAVES. GIVEN THE SPREAD OF SOLUTIONS IN RECENT DAYS...
CONFIDENCE IN SNOW AND TEMP FCSTS FOR MON-WED ESPECIALLY TUE/WED
WILL BE LOW UNTIL THAT PART OF THE FCST MOVES CLOSER TO THE SHORT
TERM.
THERE ARE SOME INDICATIONS THAT A SOMEWHAT MORE MEANINGFUL LOW PRES
WAVE MAY MOVE TOWARD THE GREAT LAKES THU/FRI AS THE WRN TROF
DEVELOPS/DEEPENS AND BEGINS TO SHIFT E.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 621 PM EST THU DEC 12 2013
CMX...EXPECT IFR VSBYS WITH FALLING SN/BLSN IN GUSTY NW FLOW THIS
EVNG TO GIVE WAY TO MVFR CONDITIONS AS THE FLOW WEAKENS AND VEERS TO
A MORE UNFVRBL NNE DIRECTION OVERNGT AND FRI.
IWD...AS THE FLOW VEERS TOWARD AN UPSLOPE N AND NE DIRECTION...
EXPECT LK EFFECT -SHSN TO INCRS OVER WRN UPR MI. SO VFR CONDITIONS
AT TAF ISSUANCE SHOULD DETERIORATE TO MVFR THEN IFR DURING THE EARLY
MRNG HRS ON FRI. AS THE LLVL WINDS VEER FURTHER TO A MORE UNFVRBL NE
DIRECTION FRI AFTN...CONDITIONS ARE LIKELY TO IMPROVE TO MVFR AND
PERHAPS VFR LATE IN THE FCST PERIOD.
SAW...EXPECT VFR CONDITIONS THRU THIS EVNG TO DETERIORATE TO MVFR
LATER TNGT AS THE FLOW VEERS TOWARD THE NW FOLLOWING A LO PRES TROF
PASSAGE. WITH A CONTINUED VEERING TO AN UPSLOPE NNE DIRECTION ON FRI
AFTN...VSBYS ARE LIKELY TO FALL TO IFR WITH MORE FREQUENT HEAVIER SHSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST THU DEC 12 2013
A PERIOD OF WNW TO NW GALES IS EXPECTED LATE THIS AFTERNOON THROUGH
THIS EVENING BEFORE DIMINISHING OVERNIGHT WITH HIGH PRES BUILDING
TOWARD THE REGION. HEAVY FREEZING SPRAY WILL ALSO CONTINUE FOR MUCH
OF THE LAKE INTO THIS EVENING. WINDS WILL FINALLY DIMINISH TO
NORTHERLY AT 15 TO 25 KNOTS OVERNIGHT INTO FRIDAY MORNING AS A WEAK
RIDGE PASSES ACROSS THE LAKE. EXPECT 10 TO 20 KT WINDS TO GRADUALLY
BACK TO THE SE BY SATURDAY AHEAD OF DEVELOPING LOW PRESSURE OVER THE
UPPER MS VALLEY. DEPENDING ON THE STRENGTH OF THE LOW AS IT MOVES
ACROSS LAKE SUPERIOR ON SATURDAY NIGHT AND SUNDAY AND THE STRENGTH OF
ANOTHER LOW MOVING UP THE EAST COAST...COULD SEE AN INCREASE IN
NORTHWESTERLY WINDS ON SUNDAY TO 25 TO 30 KTS. THIS WILL BE SHORT-
LIVED AS ANOTHER HIGH SLIDES INTO THE AREA FOR THE BEGINNING OF THE
UPCOMING WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST FRIDAY FOR MIZ006-007-
085.
LAKE SUPERIOR...
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST FRIDAY FOR
LSZ263>266.
GALE WARNING UNTIL 11 PM EST THIS EVENING FOR LSZ264-265.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...JLB
LONG TERM...ROLFSON
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
623 PM EST THU DEC 12 2013
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
ACROSS ERN NOAM RESULTING IN NW FLOW THROUGH THE NRN GREAT LAKES. A
SHORTWAVE TROUGH WAS MOVING THROUGH NW ONTARIO DRAGGING A COLD FRONT
THROUGH WRN LAKE SUPERIOR. FARTHER UPSTREAM...A WEAK CLIPPER SHRTWV
WAS MOVING FROM SRN SASK INTO THE NRN PLAINS. LES BANDS ALIGNED WITH
WNW FLOW THROUGH ERN LAKE SUPERIOR INTO NE ALGER AND NRN LUCE
COUNTIES HAD DIMINISHED SLIGHTLY AND BECOME MORE CELLULAR THIS
AFTERNOON WITH WEAKENING LOW LEVEL CONV FROM LAND BREEZE COMPONENT.
EXPECT THAT THE LOW LEVEL WINDS WILL DIMINISH AND VEER FROM WNW TO
NRLY. THIS SHOULD PUSH THE MORE SIGNIFICANT LES THROUGH MUCH OF THE
ERN CWA FROM ALGER COUNTY EASTWARD AS A STRENGTHENING LAND BREEZE
SHOULD KEEP MOST OF THE SNOW EAST OF MARQUETTE. EVEN WITH THE
SHIFTING POSITION OF THE LES BANDS...FAVORABLE SNOW GROWTH WITH THE
DGZ IN THE 1K-4K CONVECTIVE LAYER PUSHING SLR VALUES ABOVE 25/1 AND
SHOULD SUPPORT ADVISORY SNOWFALL AMOUNTS IN THE 3 TO 6 INCH RANGE.
OVER THE WEST...THE SHORTER FETCH...ACYC FLOW AND LOWER INVERSION
HEIGHTS FROM 3K-4K FT...WILL KEEP SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE.
FROM LATE TONIGHT INTO EARLY FRI...THE SASK SHRTWV AND WEAK UPPER
LEVEL DIV WITH THE RIGHT ENTRANCE OF A 140 KT 250-300 MB JET WITH
ASSOCIATED 800-600 MB FGEN MAY SUPPORT A BAND OF LIGHT SNOW.
HOWEVER...MODELS SUGGEST THAT THE BEST CHANCE OF LIGHT SNOW WITH
THESE FEATURES WILL REMAIN OVER WI. SO...ONLY CHANCE POPS WITH
ACCUMULATIONS LESS THAN A HALF INCH WERE INCLUDED.
WINDS WILL CONTINUE TO VEER FRIDAY AS ARCTIC HIGH PRES FROM
SASK/MANITOBA INTO NRN ONTARIO BUILDS INTO THE NRN LAKES. WITH WINDS
SHIFTING FROM N TO NNE THE MOST FAVORABLE LOW LEVEL CONV WILL SHIFT
FROM THE NE CWA INTO MARQUETTE COUNTY. WHILE SNOW GROWTH WILL REMAIN
FAVORABLE...INVERSION HEIGHT REMAINING NEAR 5K-6K FT WITH MAINLY
ACYC UPSTREAM FLOW MAY LIMIT LES INTENSITY AND SNOWFALL AMOUNTS
BELOW ADVY LEVELS. GENERALLY 1 TO 3 INCHES ARE EXPECTED WITH THE
GREATEST AMOUNTS IN FAR WRN ALGER COUNTY INTO ERN MARQUETTE COUNTY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
MODELS TODAY CONTINUE TO INDICATE AN OVERALL COLD PATTERN THRU THE
LONG TERM PORTION OF THE FCST. HOWEVER...WITH CURRENT DEEP EXPANSIVE
POLAR VORTEX CENTERED AROUND HUDSON BAY STILL FCST TO WEAKEN AND
RETREAT N THRU AT LEAST THE MIDDLE OF NEXT WEEK...THE COLD WILL EASE
SOME. A VAST SUPPLY OF COLD AIR WILL REMAIN ACROSS CANADA...SO ANY
SHORTWAVE TRACKING ALONG IN THE RELAXING NW FLOW PATTERN WILL BE
ABLE TO TUG COLDER AIR INTO THE UPPER LAKES. FOR THIS REASON...
MEDIUM RANGE GUIDANCE FOR SEVERAL DAYS HAS BEEN PROGRESSIVELY SLOWER
TO BRING WARMING INTO THE UPPER LAKES AND HAS ALSO BEEN MORE
TEMPERED WITH THE WARMING. AROUND THE MIDDLE OF NEXT WEEK THERE WILL
BE A TEMPORARY SHIFT IN THE PATTERN TOWARD A DEEPENING TROF OVER THE
WRN CONUS AND DOWNSTREAM BUILDING RIDGE OVER THE SE CONUS/WRN
ATLANTIC. THUS THE MIDWEEK PERIOD WILL OFFER THE BEST CHANCE OF A
WARMUP. HOW MUCH WARMING OCCURS WILL DEPEND ON THE AMPLITUDE AND
LONGITUDE OF THE TROF/RIDGE PATTERN. LATEST MODEL TRENDS POINT
TOWARD AN EWD SHIFT IN THE TROF/RIDGE PATTERN WHICH WILL LIMIT
WARMING FOR THE UPPER LAKES. IN ANY CASE...WARMING WILL ONLY BE
BRIEF AS LONGER RANGE GUIDANCE CONTINUES TO POINT TOWARD
REINTENSIFYING ARCTIC AIR ACROSS WRN/NRN CANADA DUMPING BACK INTO
THE AREA SOMETIME AROUND THE WEEKEND BEFORE CHRISTMAS. OUTSIDE OF
AREAS AFFECTED BY LES/LAKE ENHANCEMENT...THERE WON`T BE MUCH MORE
THAN SOME -SN AT TIMES DURING THE LONG TERM. THE RESURGENCE OF
ARCTIC AIR S INTO THE CONUS LATE NEXT WEEK/WEEKEND COULD OFFER THE
POTENTIAL FOR SOMETHING MORE SUBSTANTIAL IN TERMS OF WIDESPREAD
SNOWFALL.
BEGINNING FRI NIGHT...WINDS WILL CONTINUE VEERING TO THE E THEN
SE FRI NIGHT/SAT MORNING AS SFC HIGH PRES CENTER PASSES JUST N OF
LAKE SUPERIOR AND NEXT CLIPPER SHORTWAVE APPROACHES FROM THE NW. LES
THAT WILL BE OCCURRING MAINLY INTO NCNTRL UPPER MI THU AFTN WILL
SLOWLY SHIFT OUT OF NCNTRL UPPER MI AND THEN CROSS THE KEWEENAW
PENINSULA FOR A TIME LATE FRI NIGHT/SAT MORNING. DGZ WILL BE WELL
CENTERED IN THE CONVECTIVE LAYER...SO A FEW INCHES OF FLUFFY SNOW
ARE POSSIBLE IN THIS AREA OF LES THAT WILL BE SHIFTING WITH THE
WINDS. ALSO...WITH WINDS VEERING OVER NRN LAKE MI...LES OFF LAKE MI
WILL LIKELY MOVE INTO MENOMINEE COUNTY AND POSSIBLY DELTA COUNTY...
LEADING TO SOME FLUFFY SNOW ACCUMULATIONS LATE FRI NIGHT/SAT
MORNING.
ATTENTION THEN TURNS TO NEXT CLIPPER SHORTWAVE DROPPING THRU THE
UPPER GREAT LAKES SAT NIGHT/SUN. -SN ASSOCIATED WITH FEATURE SHOULD
SPREAD INTO THE AREA SAT AFTN/EVENING...AND IT LOOKS LIKE THERE WILL
BE A PERIOD OF LAKE ENHANCEMENT OFF LAKE MI IN SOUTHERLY FLOW...
LEADING TO A POTENTIAL ADVY EVENT. A BRIEF SHOT OF ARCTIC AIR
FOLLOWING SYSTEM WILL PROBABLY RESULT IN A SHORT DURATION PERIOD OF
MDT TO POSSIBLY HVY LAKE ENHANCED SNOW FOR NORTHWEST AND NORTHEAST
UPPER MI LATE SAT NIGHT/EARLY SUNDAY AS WIND SHIFTS NW. SINCE DEEP
LAYER FORCING WITH SHORTWAVE IS FAIRLY IMPRESSIVE...WILL NEED TO
WATCH FOR LOCALLY HVY LAKE ENHANCED SNOW OFF LAKE MI AHEAD OF WAVE
AND OFF LAKE SUPERIOR AS THE WAVE PASSES. AS WINDS VEER AROUND TO
THE N OR NE WITH SFC HIGH PRES PASSING ACROSS NRN ONTARIO...LIGHTER
LES WILL AGAIN SHIFT TO AFFECT MORE OF NRN UPPER MI SUN
AFTN/EVENING.
OVER THE LAST FEW DAYS...UNCERTAINTY FOR THE EARLY AND MIDDLE PARTS
OF NEXT WEEK HAS BEEN HIGH WITH REGARD TO TIMING/STRENGTH/TRACK OF
SEVERAL SHORTWAVES IN WNW FLOW. IT APPEARS THERE MAY BE A COUPLE OF
PERIODS OF WIDESPREAD -SN (CONFIDENCE HIGHEST FOR -SN ON MON) AS
WELL AS LAKE ENHANCEMENT OFF LAKE MICHIGAN AND LAKE SUPERIOR
DEPENDING ON WIND DIRECTION IMMEDIATELY PRIOR TO AND AFTER PASSAGE
OF THE WAVES. GIVEN THE SPREAD OF SOLUTIONS IN RECENT DAYS...
CONFIDENCE IN SNOW AND TEMP FCSTS FOR MON-WED ESPECIALLY TUE/WED
WILL BE LOW UNTIL THAT PART OF THE FCST MOVES CLOSER TO THE SHORT
TERM.
THERE ARE SOME INDICATIONS THAT A SOMEWHAT MORE MEANINGFUL LOW PRES
WAVE MAY MOVE TOWARD THE GREAT LAKES THU/FRI AS THE WRN TROF
DEVELOPS/DEEPENS AND BEGINS TO SHIFT E.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 621 PM EST THU DEC 12 2013
CMX...EXPECT IFR VSBYS WITH FALLING SN/BLSN IN GUSTY NW FLOW THIS
EVNG TO GIVE WAY TO MVFR CONDITIONS AS THE FLOW WEAKENS AND VEERS TO
A MORE UNFVRBL NNE DIRECTION OVERNGT AND FRI.
IWD...AS THE FLOW VEERS TOWARD AN UPSLOPE N AND NE DIRECTION...
EXPECT LK EFFECT -SHSN TO INCRS OVER WRN UPR MI. SO VFR CONDITIONS
AT TAF ISSUANCE SHOULD DETERIORATE TO MVFR THEN IFR DURING THE EARLY
MRNG HRS ON FRI. AS THE LLVL WINDS VEER FURTHER TO A MORE UNFVRBL NE
DIRECTION FRI AFTN...CONDITIONS ARE LIKELY TO IMPROVE TO MVFR AND
PERHAPS VFR LATE IN THE FCST PERIOD.
SAW...EXPECT VFR CONDITIONS THRU THIS EVNG TO DETERIORATE TO MVFR
LATER TNGT AS THE FLOW VEERS TOWARD THE NW FOLLOWING A LO PRES TROF
PASSAGE. WITH A CONTINUED VEERING TO AN UPSLOPE NNE DIRECTION ON FRI
AFTN...VSBYS ARE LIKELY TO FALL TO IFR WITH MORE FREQUENT HEAVIER SHSN.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST THU DEC 12 2013
A PERIOD OF WNW TO NW GALES IS EXPECTED LATE THIS AFTERNOON THROUGH
THIS EVENING BEFORE DIMINISHING OVERNIGHT WITH HIGH PRES BUILDING
TOWARD THE REGION. HEAVY FREEZING SPRAY WILL ALSO CONTINUE FOR MUCH
OF THE LAKE INTO THIS EVENING. WINDS WILL FINALLY DIMINISH TO
NORTHERLY AT 15 TO 25 KNOTS OVERNIGHT INTO FRIDAY MORNING AS A WEAK
RIDGE PASSES ACROSS THE LAKE. EXPECT 10 TO 20 KT WINDS TO GRADUALLY
BACK TO THE SE BY SATURDAY AHEAD OF DEVELOPING LOW PRESSURE OVER THE
UPPER MS VALLEY. DEPENDING ON THE STRENGTH OF THE LOW AS IT MOVES
ACROSS LAKE SUPERIOR ON SATURDAY NIGHT AND SUNDAY AND THE STRENGTH OF
ANOTHER LOW MOVING UP THE EAST COAST...COULD SEE AN INCREASE IN
NORTHWESTERLY WINDS ON SUNDAY TO 25 TO 30 KTS. THIS WILL BE SHORT-
LIVED AS ANOTHER HIGH SLIDES INTO THE AREA FOR THE BEGINNING OF THE
UPCOMING WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST FRIDAY FOR MIZ006-007-
085.
LAKE SUPERIOR...
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST FRIDAY FOR
LSZ263>266.
GALE WARNING UNTIL 11 PM EST THIS EVENING FOR LSZ264-265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...ROLFSON
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
431 PM EST WED DEC 11 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 407 PM EST WED DEC 11 2013
TWO MAIN ITEMS OF FOCUS IN THE SHORT TERM PERIOD...THE ONGOING LAKE
EFFECT SNOW AND THE CONTINUED COLD WEATHER.
LARGE NORTHERN STREAM UPPER TROUGH COVERS THE UPPER GREAT LAKES
REGION AT THIS TIME...ALLOWING RAP ANALYZED 850MB TEMPS TO BE
AROUND -24C. AT THE SURFACE...A LAKE INDUCED TROUGH REMAINS OVER
THE FAR EASTERN LAKE...WHILE HIGH PRESSURE CENTERED OVER NORTHERN
MISSOURI IS PUSHING A RIDGE OVER NORTHERN MINNESOTA AND NORTHWEST
WISCONSIN. THE COLD AIR MOVING OVER THE RELATIVELY WARM LAKE
SUPERIOR WATERS CONTINUES TO PRODUCE LAKE EFFECT IN THE WEST TO
NORTHWEST WIND LOCATIONS THIS AFTERNOON. THE 925/850MB TROUGH THAT
WAS OVER THE AREA THIS MORNING HAS ALREADY SHIFTED EAST OF THE CWA
AND STARTED TO BACK THE WINDS IN THE LOWER LEVELS OVER THE WESTERN
CWA. THIS CAN BE SEEN IN THE VISIBLE SATELLITE IMAGERY OVER THE
WEST...AS THE BANDS HAVE STARTED TO BECOME WEST-EAST ORIENTATED.
THESE BACKING WINDS ARE ALSO STARTING TO REACH THE CENTRAL LAKE
WHERE THE BANDS ARE NOW MORE IN A WNW DIRECTION AND WINDS AT
STANNARD ROCK HAVE SHIFTED TO THE WEST. EASTERN ALGER AND NORTHERN
LUCE HAVE SEEN THE MOST SNOW TODAY...WITH REPORTS IN THE 2-8 INCH
RANGE.
THE HIGH PRESSURE RIDGE THAT HAS STARTED TO MOVE INTO THE WESTERN
CWA WILL CONTINUE EAST TONIGHT...WHICH WILL CONTINUE TO BACK WINDS
THIS EVENING...TO MORE OF A WESTERLY DIRECTION OR EVEN
WEST-SOUTHWEST OVER THE WESTERN CWA. THESE BACKING WINDS WILL
LIKELY LEAD TO A MORE DOMINATE BAND SETTING UP OVER THE
WEST (WITH THE HELP OF COASTAL CONVERGENCE)...LIKELY IN A SIMILAR
LOCATION TO WHAT WAS SEEN ON MONDAY. UNLIKE MONDAY...INVERSION
HEIGHTS WILL BE FALLING AND MUCH LOWER DUE TO THE APPROACHING
HIGH PRESSURE RIDGE AND INCREASED SUBSIDENCE. THIS COMPRESSES THE
MOISTURE TO AROUND 5KFT FOR CLOUD TOPS...EVEN THOUGH LAKE INDUCED
EQUILIBRIUM LEVELS REACH 8-9KFT. WHILE THIS OCCURS...IT DOES TRY TO
PUSH THE BETTER LAKE FORCING INTO THE TOP OF THE DGZ...WHICH MAY AID
SNOWFALL SIZE/RATIOS TO BE A LITTLE HIGHER THAN SEEN OVER THE LAST
DAY. WITH THE AIDED CONVERGENCE DUE TO WINDS BACKING TO THE
SOUTHWEST...WOULD THINK THAT WOULD HELP OFFSET SOME OF THE LARGE
SCALE SUBSIDENCE AND LEAD TO DECENT ACCUMULATING SNOWFALL FOR
NORTHERN HOUGHTON COUNTY AND THE SOUTHERN PART OF KEWEENAW COUNTY
TONIGHT. THERE IS SOME QUESTION ON HOW QUICKLY IT WILL MOVE NORTH
AND WHERE/WHEN IT WILL STALL TONIGHT. LOCAL HIRES WRF-ARW RUNS
(WHICH HAVE PERFORMED WELL WITH LOCATIONS OVER THE LAST 24HRS) ARE
DIFFERING ON HOW FAR NORTH IT WILL GO...ALONG WITH THE 12Z NAM...SO
OPTED TO SHOW IT REACHING STOPPING AROUND THE HOUGHTON-MOHAWK AREA.
THEREFORE...DID EXPAND SNOWFALL AMOUNTS FARTHER NORTH AND ALSO THE
LES ADVISORY. WAS TEMPTED TO BUMP UP TO A WARNING SINCE THERE WERE
REPORTS OUT WEST WITH 1 IN/HR SNOWFALL IN THE COLDER AIR AND LESS
DGZ INFLUENCE...BUT WITH INVERSION HEIGHTS BEING LOWER DECIDED TO
KEEP AMOUNTS AT HIGH END ADVISORY. WILL NEED TO KEEP AN EYE ON
THINGS THIS EVENING...AS THERE IS THE POTENTIAL FOR BORDERLINE
WARNING AMOUNTS WHERE THAT BAND SETS UP. HEADING INTO
THURSDAY...SLIGHTLY WARMER 925-850MB TEMPS DOES PUSH MORE OF THE
CLOUD INTO THE DGZ...WHICH COULD AID SNOWFALL RATIOS EVEN WITH THE
CONTINUED LIMITED CLOUD DEPTH (INVERSION STAYS THE SAME). WINDS LOOK
TO VEER TO MORE OF A WEST-NORTHWEST AS THE TROUGH SLIDES SOUTH
AGAIN...SO WOULD EXPECT LESS CONVERGENCE AFFECTING THE KEWEENAW
PENINSULA AND THE STRONG CONVERGENCE BAND TO SHIFT BACK TO THE
SOUTH. AS FOR THE OTHER ADVISORIES...ENDED GOGEBIC/BARAGA AND SRN
HOUGHTON EARLY AND ALSO TRENDED ONTONAGON TO AN EARLIER END TIME
DUE THE STRONGEST BAND JUST BRUSHING THE FAR NORTHERN PART OF THAT
COUNTY.
OVER THE EAST...THE BACKING WINDS HAVE ALREADY STARTED TO PUSH
THE STRONGER BANDS NORTHEAST AND WOULD EXPECT THAT STEADY PUSH
TO CONTINUE THIS EVENING. THIS STEADY PUSH SHOULD LEAD TO MORE
STEADY/WIDESPREAD ACCUMULATIONS...GENERALLY IN THE 2-5IN RANGE.
TIMING OF THE ADVISORY FOR ALGER AND NRN SCHOOLCRAFT LOOKS GOOD AND
MAY BE ABLE TO END THE LUCE WARNING A COUPLE HOURS EARLY OVERNIGHT.
AFTER THESE BANDS PUSH NORTHEAST...WOULD EXPECT SKIES TO CLEAR OUT.
THE WESTERLY (OR EVEN SLIGHTLY WSW) FLOW WILL CONTINUE INTO TOMORROW
MORNING...BEFORE THE TROUGH DROPS TO THE SOUTH AND WINDS SHIFT BACK
TO THE WEST-NORTHWEST. THIS SHOULD BE ENOUGH TO MOVE THE BANDS BACK
ONSHORE. INVERSION HEIGHTS WILL BE A LOT LOWER THAN SEEN TODAY
(RADAR INDICATED OF 10-11KFT THIS AFTN DECREASING TO 6-7KFT LATE
TONIGHT THROUGH TOMORROW AFTERNOON). EVEN SO...ENHANCED CONVERGENCE
ALONG THE NEXT TROUGH COULD BE ENOUGH TO LEAD TO A QUICK COUPLE OF
INCHES THURSDAY AFTERNOON OVER LUCE COUNTY.
AS FOR THE COLD TEMPERATURES...ONLY MADE MINOR TWEAKS TO LOWS
TONIGHT AND WINDS. LOWS ARE A LITTLE TRICKY WITH THE HIGH
PRESSURE RIDGE TRYING TO SLIDE IN AND THE MODELS SHOWING
WINDS STRUGGLING TO DECOUPLE. BASED OFF INTERIOR LOCATIONS
LAST NIGHT FALLING TO 4-7KTS...THINK THAT SEEMS REASONABLE FOR
TONIGHT AND POTENTIALLY A LITTLE LOWER WITH THE HELP OF THE HIGH
PRESSURE RIDGE MOVING IN. EXPECT MOST LOCATIONS TO BE WELL BELOW
ZERO WITH THE COLDEST VALUES CONTINUING OVER THE INTERIOR WEST AND
CENTRAL (LOWS IN THE TEENS BELOW ZERO). WIND CHILL ADVISORY LOOKS
TO BE IN GOOD SHAPE AFTER THE MINOR ADJUSTMENTS AND WILL LEAVE THAT
AS IS. ONE OTHER ITEM TO NOTE IS A WEAK SHORTWAVE DIVING SOUTHEAST
ON THE BACK SIDE OF THE UPPER TROUGH THAT WILL MOVE THROUGH
NORTHERN MINNESOTA THIS EVENING AND INTO WISCONSIN OVERNIGHT. MAIN
INFLUENCE WILL BE SOME MID-HIGH CLOUDS...BUT INDICATIONS ARE THAT
MOST OF THOSE CLOUDS WILL STAY SOUTHWEST OF THE CWA TONIGHT BUT MAY
STREAM OVER DURING THE DAY TOMORROW. AREAS RIGHT ALONG THE WISCONSIN
BORDER WOULD HAVE THE BEST OPPORTUNITY FOR THESE MID CLOUDS...WHICH
COULD LEAD TO TEMPS WARMING SLIGHTLY TOWARDS DAYBREAK.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 430 PM EST WED DEC 11 2013
MODELS CONTINUE TO SUGGEST AN OVERALL COLD PATTERN THRU THE LONG
TERM PORTION OF THE FCST. HOWEVER...WITH CURRENT DEEP EXPANSIVE
POLAR VORTEX CENTERED AROUND HUDSON BAY WEAKENING AND RETREATING N
LATE THIS WEEK THRU AT LEAST THE MIDDLE OF NEXT WEEK...THE COLD WILL
EASE SOME. A VAST SUPPLY OF COLD AIR WILL REMAIN ACROSS CANADA...SO
ANY SHORTWAVE TRACKING ALONG IN THE RELAXING NW FLOW PATTERN WILL BE
ABLE TO BRING A SURGE OF COLDER AIR INTO THE UPPER LAKES. OVER THE
PAST SEVERAL DAYS...MEDIUM RANGE GUIDANCE HAS BEEN PROGRESSIVELY
SLOWER TO BRING WARMING INTO THE UPPER LAKES FOR THIS REASON. LATER
DOWN THE ROAD NEXT WEEK...THERE ARE SUGGESTIONS OF A TEMPORARY SHIFT
IN THE PATTERN TOWARD A DEEPENING TROF OVER THE WRN CONUS AND
DOWNSTREAM BUILDING RIDGE OVER THE SE CONUS/WRN ATLANTIC. THIS WILL
OFFER THE BEST CHANCE OF A WARMUP THAT WOULD OCCUR AROUND THE MIDDLE
NEXT WEEK. HOW MUCH WARMING OCCURS WILL DEPEND ON THE AMPLITUDE AND
LONGITUDE OF THE TROF/RIDGE PATTERN. WHATEVER HAPPENS...ANY WARMING
WILL ONLY BE BRIEF AS LONGER RANGE GUIDANCE POINTS TOWARD
REINTENSIFYING ARCTIC AIR ACROSS WRN/NRN CANADA DUMPING BACK INTO
THE AREA SOMETIME AROUND THE WEEKEND BEFORE CHRISTMAS OR EARLY
CHRISTMAS WEEK. OUTSIDE OF THE AREAS AFFECTED BY LES...DON`T EXPECT
MUCH MORE THAN SOME -SN AT TIMES DURING THE LONG TERM. POSSIBLE
BRIEF PATTERN CHANGE LATER NEXT WEEK COULD OFFER THE POTENTIAL FOR
SOMETHING MORE SUBSTANTIAL IN TERMS OF PCPN.
BEGINNING THU NIGHT...SHORTWAVE PASSING ACROSS NRN ONTARIO WILL SEND
A SFC TROF S THRU THE UPPER LAKES...CAUSING WINDS TO VEER NW OR N BY
FRI MORNING. AS A RESULT...ONGOING WRLY FLOW LES LATE THU AFTN WILL
SPREAD S...AFFECTING MOST IF NOT ALL OF NRN UPPER MI BY FRI MORNING.
ALTHOUGH THERE IS NOT MUCH IN THE WAY OF DEEP LAYER FORCING...PERIOD
OF DEEPER MOISTURE COMBINED WITH CONVERGENCE ALONG TROF SHOULD YIELD
A SHORT PERIOD OF MDT SNOW AND POSSIBLY BRIEF HVY SNOW AS TROF
SWEEPS S THU NIGHT AND FRI MORNING. BEHIND TROF...INVERSION SETTLES
TO AROUND 5-6KFT FRI. LARGER SCALE LOW-LEVEL FLOW ALSO BECOMES MORE
ANTICYCLONIC FRI. ON THE OTHER HAND...DIMINISHING BOUNDARY LAYER
WINDS MAY ALLOW FOR LOCALIZED CONVERGENCE. IN FACT...NAM INDICATES
WINDS VEERING TO ESE OFF ERN UPPER MI DURING THE DAY FRI...
RESULTING IN A ZONE OF ENHANCED CONVERGENCE EXTENDING ACROSS FAR SE
LAKE SUPERIOR TO THE MARQUETTE AREA. WILL BE SOMETHING TO MONITOR.
OTHERWISE...DGZ WILL BEGIN TO BECOME BETTER LOCATED WITHIN THE
CONVECTIVE LAYER AND UPWARD MOTION ZONE...LEADING TO HIGHER SNOW TO
WATER RATIOS. SO...SHOULD BE ABLE TO FLUFF UP SOME DECENT SNOW
ACCUMULATIONS FRI WHERE LES IS MOST PERISTENT (NCNTRL UPPER MI). OUT
W DURING THE DAY...WINDS MAY END UP VEERING ENOUGH TO PUSH MOST OF
THE LES OFFSHORE OF WRN UPPER MI...EXCEPT FOR THE KEWEENAW.
WINDS CONTINUE VEERING TO THE E THEN SE FRI NIGHT/SAT MORNING AS SFC
HIGH PRES CENTER PASSES JUST N OF LAKE SUPERIOR. LES THAT WILL BE
OCCURRING MAINLY INTO NCNTRL UPPER MI THU AFTN WILL THEN SLOWLY
SHIFT...CROSSING THE KEWEENAW PENINSULA FOR A TIME LATER FRI
NIGHT/SAT MORNING. DGZ WILL STILL BE WELL CENTERED IN THE CONVECTIVE
LAYER...SO A FEW INCHES OF FLUFFY SNOW ARE POSSIBLE. IF WINDS VEER
ENOUGH OVER NRN LAKE MI...SOME LIGHT LES MAY AFFECT PORTIONS OF
MENOMINEE COUNTY.
ATTENTION THEN TURNS TO NEXT CLIPPER SHORTWAVE DROPPING THRU THE
UPPER GREAT LAKES SAT NIGHT/SUN. -SN ASSOCIATED WITH FEATURE SHOULD
SPREAD INTO THE AREA SAT AFTN/EVENING...AND IT LOOKS LIKE THERE WILL
BE A QUICK PERIOD OF LAKE ENHANCEMENT OFF LAKE MI IN SOUTHERLY
FLOW...LEADING TO A POTENTIAL ADVY EVENT. A VERY BRIEF SHOT OF
ARCTIC AIR FOLLOWING SYSTEM WILL PROBABLY RESULT IN A SHORT DURATION
BOUT OF MDT TO POSSIBLY HVY LAKE ENHANCED SNOW FOR NORTHWEST AND
NORTHEAST UPPER MI LATE SAT NIGHT/EARLY SUNDAY AS WIND SHIFTS NW. AS
WINDS VEER AROUND TO THE N OR NE WITH SFC HIGH PRES PASSING ACROSS
NRN ONTARIO...LIGHTER LES WILL AGAIN SHIFT TO AFFECT MORE OF NRN
UPPER MI SUN AFTN/EVENING.
FCST IS MUCH MORE UNCERTAIN HEADING INTO MON/TUE AS MEDIUM RANGE
MODELS ARE HAVING TROUBLE WITH SEVERAL SHORTWAVES IN THE WNW FLOW.
GIVEN THE UNCERTAINTY FROM TODAYS MODEL RUNS AND PREVIOUS RUNS...A
SIMPLE CONSENSUS WILL BE UTILIZED MON/TUE. DEPENDING ON
STRENGTH/TRACK OF THE WAVES...THERE MAY BE A COUPLE OF PERIODS OF
WIDESPREAD -SN AS WELL AS LAKE ENHANCEMENT DEPENDING ON WIND
DIRECTION.
HIGH UNCERTAINTY CONTINUES WED AS ECMWF SHOWS THE POSSIBLE MID WEEK
WARMUP ALLUDED TO EARLIER...WHILE THE GFS DUMPS ARCTIC AIR BACK INTO
THE AREA. AT 00Z THU...850MB TEMPS RANGE FROM ROUGHLY AROUND -2C
WITH THE ECWMF TO -20C WITH THE GFS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 100 PM EST WED DEC 11 2013
LAKE EFFECT SNOW IS EXPECTED TO CONTINUE AT KCMX THROUGH MUCH OF
THE TAF PERIOD. EXPECT MODERATE SNOW TO CONTINUE THROUGH THE
AFTERNOON AND WITH THE GUSTY WEST-NORTHWEST WINDS...IT SHOULD
COMBINE WITH BLOWING SNOW TO PRODUCE IFR AND OCCASIONAL LIFR
VISIBILITIES THROUGH THE AFTERNOON. AS WINDS SHIFT TO THE SOUTHWEST
THIS EVENING...EXPECT A STRONG BAND TO DEVELOP ON THE ENHANCED
CONVERGENCE AND IMPACT THE SITE AROUND 00Z AND CONTINUE THROUGH THE
EVENING. THERE IS A LITTLE UNCERTAINTY ON HOW FAR NORTH IT WILL
LIFT...BUT LATEST INDICATIONS ARE THE BAND WILL MOVE NORTH OF THE
TAF SITE FOR A PERIOD AND HAVE TRENDED THAT WAY IN THE TAF. AS
WINDS SHIFT TO THE NORTHWEST THURSDAY MORNING...LIGHT TO MODERATE
LAKE EFFECT SNOW WILL MOVE BACK INTO THE SITE.
FOR KSAW/KIWD...THE UNFAVORABLE WIND DIRECTIONS FOR THE SITE WILL
LEAD TO GENERALLY VFR CONDITIONS. GUSTY WINDS AT KIWD HAS BEEN
PRODUCING BLSN AND HAVE MENTIONED MVFR VISIBILITIES TO ACCOUNT FOR
THAT THIS AFTERNOON. THERE ARE SOME HINTS OF INCREASING CLOUDS AND
POTENTIAL MVFR CEILINGS AT KIWD LATE TONIGHT INTO THURSDAY
MORNING WITH A WEAK DISTURBANCE MOVING THROUGH...BUT CONFIDENCE WAS
TOO LOW TO INCLUDE AT THIS POINT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EST WED DEC 11 2013
WEST TO NORTHWEST WINDS OF 20-30KTS WILL WEAKEN SLIGHTLY TONIGHT AS
A HIGH PRESSURE RIDGE BRUSHES THE AREA. A WEAK TROUGH MOVING ACROSS
THE AREA ON THURSDAY WILL SHIFT WINDS TO MORE OF A NORTHWESTERLY
DIRECTION THURSDAY AFTERNOON AND TO THE NORTH THURSDAY NIGHT AS
ANOTHER HIGH PRESSURE RIDGE (THIS TIME FROM CENTRAL CANADA) NOSES
INTO WESTERN LAKE SUPERIOR. THIS RIDGE IS EXPECTED TO WEAKEN THE
WINDS BELOW 20KTS. DEPENDING ON THE STRENGTH OF A LOW MOVING ACROSS
LAKE SUPERIOR ON SATURDAY NIGHT AND SUNDAY AND THE STRENGTH OF THE
LOW MOVING UP THE EAST COAST...COULD SEE A INCREASE IN
NORTHWESTERLY WINDS ON SUNDAY TO 25-30KTS. THIS WILL BE SHORT LIVED
AS ANOTHER HIGH SLIDES INTO THE AREA FOR THE BEGINNING OF THE
UPCOMING WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL NOON EST /11 AM CST/ THURSDAY FOR
MIZ002-004-005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ002-
006.
LAKE EFFECT SNOW ADVISORY UNTIL 9 AM EST THURSDAY FOR MIZ001-003.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THURSDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 6 AM EST /5 AM CST/ THURSDAY
FOR LSZ162-240>245-248>251-266.
HEAVY FREEZING SPRAY WARNING UNTIL 3 PM EST THURSDAY FOR
LSZ263>265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...ROLFSON
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
408 PM EST WED DEC 11 2013
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 407 PM EST WED DEC 11 2013
TWO MAIN ITEMS OF FOCUS IN THE SHORT TERM PERIOD...THE ONGOING LAKE
EFFECT SNOW AND THE CONTINUED COLD WEATHER.
LARGE NORTHERN STREAM UPPER TROUGH COVERS THE UPPER GREAT LAKES
REGION AT THIS TIME...ALLOWING RAP ANALYZED 850MB TEMPS TO BE
AROUND -24C. AT THE SURFACE...A LAKE INDUCED TROUGH REMAINS OVER
THE FAR EASTERN LAKE...WHILE HIGH PRESSURE CENTERED OVER NORTHERN
MISSOURI IS PUSHING A RIDGE OVER NORTHERN MINNESOTA AND NORTHWEST
WISCONSIN. THE COLD AIR MOVING OVER THE RELATIVELY WARM LAKE
SUPERIOR WATERS CONTINUES TO PRODUCE LAKE EFFECT IN THE WEST TO
NORTHWEST WIND LOCATIONS THIS AFTERNOON. THE 925/850MB TROUGH THAT
WAS OVER THE AREA THIS MORNING HAS ALREADY SHIFTED EAST OF THE CWA
AND STARTED TO BACK THE WINDS IN THE LOWER LEVELS OVER THE WESTERN
CWA. THIS CAN BE SEEN IN THE VISIBLE SATELLITE IMAGERY OVER THE
WEST...AS THE BANDS HAVE STARTED TO BECOME WEST-EAST ORIENTATED.
THESE BACKING WINDS ARE ALSO STARTING TO REACH THE CENTRAL LAKE
WHERE THE BANDS ARE NOW MORE IN A WNW DIRECTION AND WINDS AT
STANNARD ROCK HAVE SHIFTED TO THE WEST. EASTERN ALGER AND NORTHERN
LUCE HAVE SEEN THE MOST SNOW TODAY...WITH REPORTS IN THE 2-8 INCH
RANGE.
THE HIGH PRESSURE RIDGE THAT HAS STARTED TO MOVE INTO THE WESTERN
CWA WILL CONTINUE EAST TONIGHT...WHICH WILL CONTINUE TO BACK WINDS
THIS EVENING...TO MORE OF A WESTERLY DIRECTION OR EVEN
WEST-SOUTHWEST OVER THE WESTERN CWA. THESE BACKING WINDS WILL
LIKELY LEAD TO A MORE DOMINATE BAND SETTING UP OVER THE
WEST (WITH THE HELP OF COASTAL CONVERGENCE)...LIKELY IN A SIMILAR
LOCATION TO WHAT WAS SEEN ON MONDAY. UNLIKE MONDAY...INVERSION
HEIGHTS WILL BE FALLING AND MUCH LOWER DUE TO THE APPROACHING
HIGH PRESSURE RIDGE AND INCREASED SUBSIDENCE. THIS COMPRESSES THE
MOISTURE TO AROUND 5KFT FOR CLOUD TOPS...EVEN THOUGH LAKE INDUCED
EQUILIBRIUM LEVELS REACH 8-9KFT. WHILE THIS OCCURS...IT DOES TRY TO
PUSH THE BETTER LAKE FORCING INTO THE TOP OF THE DGZ...WHICH MAY AID
SNOWFALL SIZE/RATIOS TO BE A LITTLE HIGHER THAN SEEN OVER THE LAST
DAY. WITH THE AIDED CONVERGENCE DUE TO WINDS BACKING TO THE
SOUTHWEST...WOULD THINK THAT WOULD HELP OFFSET SOME OF THE LARGE
SCALE SUBSIDENCE AND LEAD TO DECENT ACCUMULATING SNOWFALL FOR
NORTHERN HOUGHTON COUNTY AND THE SOUTHERN PART OF KEWEENAW COUNTY
TONIGHT. THERE IS SOME QUESTION ON HOW QUICKLY IT WILL MOVE NORTH
AND WHERE/WHEN IT WILL STALL TONIGHT. LOCAL HIRES WRF-ARW RUNS
(WHICH HAVE PERFORMED WELL WITH LOCATIONS OVER THE LAST 24HRS) ARE
DIFFERING ON HOW FAR NORTH IT WILL GO...ALONG WITH THE 12Z NAM...SO
OPTED TO SHOW IT REACHING STOPPING AROUND THE HOUGHTON-MOHAWK AREA.
THEREFORE...DID EXPAND SNOWFALL AMOUNTS FARTHER NORTH AND ALSO THE
LES ADVISORY. WAS TEMPTED TO BUMP UP TO A WARNING SINCE THERE WERE
REPORTS OUT WEST WITH 1 IN/HR SNOWFALL IN THE COLDER AIR AND LESS
DGZ INFLUENCE...BUT WITH INVERSION HEIGHTS BEING LOWER DECIDED TO
KEEP AMOUNTS AT HIGH END ADVISORY. WILL NEED TO KEEP AN EYE ON
THINGS THIS EVENING...AS THERE IS THE POTENTIAL FOR BORDERLINE
WARNING AMOUNTS WHERE THAT BAND SETS UP. HEADING INTO
THURSDAY...SLIGHTLY WARMER 925-850MB TEMPS DOES PUSH MORE OF THE
CLOUD INTO THE DGZ...WHICH COULD AID SNOWFALL RATIOS EVEN WITH THE
CONTINUED LIMITED CLOUD DEPTH (INVERSION STAYS THE SAME). WINDS LOOK
TO VEER TO MORE OF A WEST-NORTHWEST AS THE TROUGH SLIDES SOUTH
AGAIN...SO WOULD EXPECT LESS CONVERGENCE AFFECTING THE KEWEENAW
PENINSULA AND THE STRONG CONVERGENCE BAND TO SHIFT BACK TO THE
SOUTH. AS FOR THE OTHER ADVISORIES...ENDED GOGEBIC/BARAGA AND SRN
HOUGHTON EARLY AND ALSO TRENDED ONTONAGON TO AN EARLIER END TIME
DUE THE STRONGEST BAND JUST BRUSHING THE FAR NORTHERN PART OF THAT
COUNTY.
OVER THE EAST...THE BACKING WINDS HAVE ALREADY STARTED TO PUSH
THE STRONGER BANDS NORTHEAST AND WOULD EXPECT THAT STEADY PUSH
TO CONTINUE THIS EVENING. THIS STEADY PUSH SHOULD LEAD TO MORE
STEADY/WIDESPREAD ACCUMULATIONS...GENERALLY IN THE 2-5IN RANGE.
TIMING OF THE ADVISORY FOR ALGER AND NRN SCHOOLCRAFT LOOKS GOOD AND
MAY BE ABLE TO END THE LUCE WARNING A COUPLE HOURS EARLY OVERNIGHT.
AFTER THESE BANDS PUSH NORTHEAST...WOULD EXPECT SKIES TO CLEAR OUT.
THE WESTERLY (OR EVEN SLIGHTLY WSW) FLOW WILL CONTINUE INTO TOMORROW
MORNING...BEFORE THE TROUGH DROPS TO THE SOUTH AND WINDS SHIFT BACK
TO THE WEST-NORTHWEST. THIS SHOULD BE ENOUGH TO MOVE THE BANDS BACK
ONSHORE. INVERSION HEIGHTS WILL BE A LOT LOWER THAN SEEN TODAY
(RADAR INDICATED OF 10-11KFT THIS AFTN DECREASING TO 6-7KFT LATE
TONIGHT THROUGH TOMORROW AFTERNOON). EVEN SO...ENHANCED CONVERGENCE
ALONG THE NEXT TROUGH COULD BE ENOUGH TO LEAD TO A QUICK COUPLE OF
INCHES THURSDAY AFTERNOON OVER LUCE COUNTY.
AS FOR THE COLD TEMPERATURES...ONLY MADE MINOR TWEAKS TO LOWS
TONIGHT AND WINDS. LOWS ARE A LITTLE TRICKY WITH THE HIGH
PRESSURE RIDGE TRYING TO SLIDE IN AND THE MODELS SHOWING
WINDS STRUGGLING TO DECOUPLE. BASED OFF INTERIOR LOCATIONS
LAST NIGHT FALLING TO 4-7KTS...THINK THAT SEEMS REASONABLE FOR
TONIGHT AND POTENTIALLY A LITTLE LOWER WITH THE HELP OF THE HIGH
PRESSURE RIDGE MOVING IN. EXPECT MOST LOCATIONS TO BE WELL BELOW
ZERO WITH THE COLDEST VALUES CONTINUING OVER THE INTERIOR WEST AND
CENTRAL (LOWS IN THE TEENS BELOW ZERO). WIND CHILL ADVISORY LOOKS
TO BE IN GOOD SHAPE AFTER THE MINOR ADJUSTMENTS AND WILL LEAVE THAT
AS IS. ONE OTHER ITEM TO NOTE IS A WEAK SHORTWAVE DIVING SOUTHEAST
ON THE BACK SIDE OF THE UPPER TROUGH THAT WILL MOVE THROUGH
NORTHERN MINNESOTA THIS EVENING AND INTO WISCONSIN OVERNIGHT. MAIN
INFLUENCE WILL BE SOME MID-HIGH CLOUDS...BUT INDICATIONS ARE THAT
MOST OF THOSE CLOUDS WILL STAY SOUTHWEST OF THE CWA TONIGHT BUT MAY
STREAM OVER DURING THE DAY TOMORROW. AREAS RIGHT ALONG THE WISCONSIN
BORDER WOULD HAVE THE BEST OPPORTUNITY FOR THESE MID CLOUDS...WHICH
COULD LEAD TO TEMPS WARMING SLIGHTLY TOWARDS DAYBREAK.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 549 AM EST WED DEC 11 2013
MAIN LONG TERM FORECAST CONCERNS FOCUS ON CONTINUED COLD WEATHER AND
PERSISTENT...THOUGH...GENERALLY DIMINISHING LAKE EFFECT SNOWS
THURSDAY INTO FRIDAY...THEN SOME SYSTEM SNOW ARRIVING SAT AND SAT
NIGHT WITH PASSAGE OF SHORTWAVE/INVERTED TROUGH...AND FINALLY
ANOTHER BLAST OF ARCTIC AIR IN THE WAKE OF THE TROUGH RESULTING IN
MORE LES LATE SAT NIGHT INTO SUN NIGHT.
THURSDAY...THE AIRMASS MODERATES SOME AS BETTER WAA KICKS IN MAINLY
SOUTH OF THE AREA...ALTHOUGH SOME WEAK ISENTROPIC LIFT ASSOC MAY
PRODUCE A FEW DUSTING OF LIGHT SNOW/FLURRIES THURSDAY MORNING ALONG
THE WI BORDER. INITIAL DRYNESS OF AIRMASS AND WEAK SUPPORT SHOULD
GENERALLY LIMIT MOST PRECIPITATION FROM REACHING THE GROUND. THE
PASSAGE OF THE MID-LEVEL TROUGH AXIS AND Q-VECT DIV AND ASSOC
DRYING/SUBSIDENCE BEHIND IT MAY BE ENOUGH TO FINALLY DISRUPT AND
WEAKEN LES BANDS OVER THE KEWEENAW AND FAR ERN SHORELINE OF THE CWA
BY THE AFTERNOON HRS. LES BANDS WILL LIKELY BE PUSHED OFFSHORE OF
ERN COUNTIES EARLY IN THE MORNING BY DEVELOPING WAA SW FLOW.
INCREASING SW WINDS WILL ALSO LEAD TO BITTER COLD WIND CHILLS OF 20
TO 30 BELOW THU MORNING WARRANTING WIND CHILL ADVISORIES FOR MUCH OF
WRN HALF INTERIOR. EXPECT GREATEST SNOWFALL (UP TO 4 INCHES) OVER
THE KEWEENAW AND ESPECIALLY NEAR HOUGHTON IN CONVERGENT WRLY FLOW.
THU NIGHT INTO FRIDAY...WINDS VEERING FM WNW THU EVENING TO MORE
NRLY BY FRI MORNING IN WAKE OF ANOTHER CLIPPER SYSTEM AND ARCTIC
FRONTAL PASSAGE WILL BRING LES BACK ONSHORE ACROSS MUCH OF THE NRN
CWA. INCREASED LOW-LVL CONVERGENCE OVER ERN LAKE SUPERIOR DUE TO
CONVERGING LAND BREEZES MAY ALLOW A MODERATE LES BAND OR TWO TO SET
UP OVER THE ERN COUNTIES THU NIGHT IN CONVERGENT NW-NNW FLOW.
ELSEWHERE...LACK OF GOOD LOW-LVL CONVERGENCE AND ADVECTION OF DRIER
AIR FROM NORTH OF LAKE BENEATH LOWERING INVERSION HGTS AS NOTED ON
GFS BUFR SNDGS SHOULD GREATLY LIMIT LES INTENSITY AND THUS ACCUMS.
BY FRI AFTERNOON ANY REMAINING LES SHOULD BE QUICKLY DIMINISHING AS
SFC-8H FLOW BCMS SHARPLY ANTICYCLONIC.
FRI NIGHT INTO SATURDAY...WINDS ARE EXPECTED TO GRADUALLY VEER FROM
NORTH FRI EVENING TO EAST BY SATURDAY MORNING AS SFC HIGH PRESSURE
BUILDING DOWN FROM MANITOBA AND WRN ONTARIO SLIDES NORTH OF LAKE
SUPERIOR AND INTO ERN ONTARIO BY 12Z SAT. DEVELOPING NE AND THEN
ERLY FLOW WILL SHIFT INTO REMAINING LIGHT LES OVER LAKE SUPERIOR
INTO THE NW PORTION OF THE CWA. SOME LES COULD ALSO DEVELOP OVER THE
SRN HALF OF MNM COUNTY IN NE-E FLOW WITH LIGHT ACCUMS POSSIBLE.
MODERATE TO DEEP 700-300 MB Q-VECT CONV MOVING ACROSS THE AREA ON
SATURDAY AHEAD OF THE NEXT CLIPPER SHORTWAVE DIVING DOWN FROM
MANITOBA WRN ONTARIO WILL SPREAD LIGHT SNOW ACROSS MUCH OF THE AREA
ESPECIALLY SATURDAY AFTERNOON. INITIAL DRYNESS OF AIRMASS MAY DELAY
ONSET OF SNOW AND LIMIT ACCUMS...FOR THAT REASON ONLY HAVE CHC POPS
FOR NOW ACROSS CWA.
SATURDAY NIGHT INTO SUNDAY NIGHT...MODELS INDICATE MODERATE TO STRONG
Q-VECT CONV AHEAD OF VIGOROUS CLIPPER SHORTWAVE. ENHANCEMENT FROM
SHORTWAVE COMBINED WITH ANOTHER BLAST OF COLD ARCTIC AIR BEHIND IT
WILL LIKELY RESULT IN ANOTHER BOUT OF MODERATE TO HEAVY LAKE
ENHANCED SNOW FOR NORTHWEST AND NORTHEAST UPPER MI LATE SAT NIGHT
INTO SUNDAY AS WIND SHIFTS NW IN THE WAKE OF THE CLIPPER SYSTEM.
STRONGLY CONVERGENT NW FLOW FCST TO DEVELOP OVER ERN LAKE SUPERIOR
WILL LIKELY FAVOR ERN COUNTIES FOR HIGHEST ACCUMS. PASSAGE OF LAKE
ENHANCED TROUGH WILL SHIFT WINDS TO NNE AND PUSH HEAVIER LAKE SNOW
INTO NORTH CENTRAL UPPER MI LATE SUNDAY. SFC HIGH PRESSURE BUILDING
OVER THE REGION WILL WEAKEN WINDS AND QUICKLY DIMINISH ANY REMAINING
LES OVER THE NRN PORTION OF THE CWA.
MONDAY AND TUESDAY...MODELS SHOW SIGNIFICANT DIFFERENCES IN HANDLING
OF NEXT CLIPPER SHORTWAVE DIVING DOWN INTO THE UPPER GREAT LAKES FOR
EARLY NEXT WEEK. THE ECMWF IS DEEPER WITH THIS FEATURE THAN THE GFS
AND ADVANCES IT QUICKER INTO THE REGION. IF THE ECMWF PANS OUT WAA
SSW FLOW AND ENHANCEMENT ASSOC AHEAD OF THE SYSTEM COULD BRING IN
SOME MODERATE TO BRIEFLY HEAVY LES INTO SE AND FAR ERN COUNTIES OF
THE CWA MON AFTERNOON INTO MON EVENING. WINDS VEERING WNW BEHIND THE
CLIPPER WILL BRING BACK LES INTO NW AND NE PORTIONS OF UPPER MI MON
NIGHT INTO TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 100 PM EST WED DEC 11 2013
LAKE EFFECT SNOW IS EXPECTED TO CONTINUE AT KCMX THROUGH MUCH OF
THE TAF PERIOD. EXPECT MODERATE SNOW TO CONTINUE THROUGH THE
AFTERNOON AND WITH THE GUSTY WEST-NORTHWEST WINDS...IT SHOULD
COMBINE WITH BLOWING SNOW TO PRODUCE IFR AND OCCASIONAL LIFR
VISIBILITIES THROUGH THE AFTERNOON. AS WINDS SHIFT TO THE SOUTHWEST
THIS EVENING...EXPECT A STRONG BAND TO DEVELOP ON THE ENHANCED
CONVERGENCE AND IMPACT THE SITE AROUND 00Z AND CONTINUE THROUGH THE
EVENING. THERE IS A LITTLE UNCERTAINTY ON HOW FAR NORTH IT WILL
LIFT...BUT LATEST INDICATIONS ARE THE BAND WILL MOVE NORTH OF THE
TAF SITE FOR A PERIOD AND HAVE TRENDED THAT WAY IN THE TAF. AS
WINDS SHIFT TO THE NORTHWEST THURSDAY MORNING...LIGHT TO MODERATE
LAKE EFFECT SNOW WILL MOVE BACK INTO THE SITE.
FOR KSAW/KIWD...THE UNFAVORABLE WIND DIRECTIONS FOR THE SITE WILL
LEAD TO GENERALLY VFR CONDITIONS. GUSTY WINDS AT KIWD HAS BEEN
PRODUCING BLSN AND HAVE MENTIONED MVFR VISIBILITIES TO ACCOUNT FOR
THAT THIS AFTERNOON. THERE ARE SOME HINTS OF INCREASING CLOUDS AND
POTENTIAL MVFR CEILINGS AT KIWD LATE TONIGHT INTO THURSDAY
MORNING WITH A WEAK DISTURBANCE MOVING THROUGH...BUT CONFIDENCE WAS
TOO LOW TO INCLUDE AT THIS POINT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 407 PM EST WED DEC 11 2013
WEST TO NORTHWEST WINDS OF 20-30KTS WILL WEAKEN SLIGHTLY TONIGHT AS
A HIGH PRESSURE RIDGE BRUSHES THE AREA. A WEAK TROUGH MOVING ACROSS
THE AREA ON THURSDAY WILL SHIFT WINDS TO MORE OF A NORTHWESTERLY
DIRECTION THURSDAY AFTERNOON AND TO THE NORTH THURSDAY NIGHT AS
ANOTHER HIGH PRESSURE RIDGE (THIS TIME FROM CENTRAL CANADA) NOSES
INTO WESTERN LAKE SUPERIOR. THIS RIDGE IS EXPECTED TO WEAKEN THE
WINDS BELOW 20KTS. DEPENDING ON THE STRENGTH OF A LOW MOVING ACROSS
LAKE SUPERIOR ON SATURDAY NIGHT AND SUNDAY AND THE STRENGTH OF THE
LOW MOVING UP THE EAST COAST...COULD SEE A INCREASE IN
NORTHWESTERLY WINDS ON SUNDAY TO 25-30KTS. THIS WILL BE SHORT LIVED
AS ANOTHER HIGH SLIDES INTO THE AREA FOR THE BEGINNING OF THE
UPCOMING WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL NOON EST /11 AM CST/ THURSDAY FOR
MIZ002-004-005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ002-
006.
LAKE EFFECT SNOW ADVISORY UNTIL 9 AM EST THURSDAY FOR MIZ001-003.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THURSDAY FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 6 AM EST /5 AM CST/ THURSDAY
FOR LSZ162-240>245-248>251-266.
HEAVY FREEZING SPRAY WARNING UNTIL 3 PM EST THURSDAY FOR
LSZ263>265.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...SRF
LONG TERM...VOSS
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
227 PM EST WED DEC 11 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 327 AM EST WED DEC 11 2013
COLD AND SNOWY WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK
AND WEEKEND. A BURST OF HEAVIER SNOW IS ON THE WAY TO AREAS NEAR TO
MAINLY SOUTH OF INTERSTATE 96 FROM AROUND DAYBREAK THROUGH THE REST
OF THE MORNING INTO THE EARLY TO MID AFTERNOON HOURS. ANOTHER BURST
OF HEAVIER LAKE EFFECT SNOW WILL OCCUR THURSDAY FROM HOLLAND
NORTHWARD AS WINDS BACK TO THE SOUTHWEST. LOW PRESSURE WILL BRING
MORE SNOW SATURDAY WITH SEVERAL MORE ROUNDS OF SNOW EXPECTED LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 226 PM EST WED DEC 11 2013
WITH THE HIGHER REFLECTIVITIES NOW SOUTH OF THE AREA FOR THE MOST
PART AND SOME SUN AT TIMES HAVE DROPPED THE WINTER WEATHER
ADVISORY. ROADS WILL CONTINUE TO BE SLIPPERY IN SPOTS AS COLD AIR
TEMPS...DROPPING INTO THE SINGLE DIGITS IN QUITE A FEW AREAS THIS
EVENING...MAKE ROAD SALT LESS EFFECTIVE. WIND CHILL VALUES WILL
DIP TO AROUND ZERO F THIS EVENING. LAKE EFFECT SNOW SHOWERS WILL
CONTINUE THIS EVENING...BUT NOT EXPECTING SIGNIFICANT
ACCUMULATIONS.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY AFTERNOON)
ISSUED AT 327 AM EST WED DEC 11 2013
A CONSENSUS OF HIGHER RESOLUTION SHORT RANGE GUIDANCE INCLUDING THE
RUC... HRRR AND 4KM WRF NMM ALL INDICATE THAT ANOTHER BURST OF
HEAVIER SNOW WILL DEVELOP NEAR TO MAINLY SOUTH OF INTERSTATE 96
DURING THE EARLY TO MID MORNING HOURS. THE HEAVIEST SNOW WILL LINGER
THROUGH AT LEAST EARLY AFTERNOON BEFORE TAPERING OFF. A COUPLE OF
UPPER LEVEL DISTURBANCES MOVING THROUGH LATER THIS MORNING INTO THE
AFTERNOON WILL ENHANCE THE SNOW WITH DEEP LOW TO MID LEVEL MOISTURE
IN PLACE THROUGH 18Z THIS AFTERNOON AND WITH H8 TEMPS WAY DOWN
AROUND -16 TO -18 C.
HEAVIEST SNOW FROM MID MORNING THROUGH EARLY TO MID AFTERNOON WILL
FALL MAINLY SOUTH OF I-96 WITH ABOUT 3 TO 5 INCHES OF SNOW EXPECTED
DOWN AROUND HASTINGS... ALLEGAN... SOUTH HAVEN AND KALAMAZOO. A
BUKFIT X-SECTION FOR SOUTH HAVEN SHOWS ABOUT 10 MICROBARS/SEC OF
LIFT LATE THIS MORNING WITH INVERSION HEIGHTS UP AROUND 8-9 KFT. OUR
ONGOING WINTER WEATHER HEADLINES LOOK EXCELLENT AND WILL REMAIN
UNCHANGED.
WNW TO WEST FLOW LES WILL CONTINUE TONIGHT WITH SUFFICIENT MOISTURE
STILL IN PLACE AND H8 TEMPS STILL DOWN AROUND -16 TO -18 C. THEN
WINDS WILL BACK TO THE WSW TO SW THURSDAY FAVORING AREAS FROM AROUND
BIV NORTHWARD OVER OUR NW FCST AREA TO RECEIVE SEVERAL INCHES OF
LAKE EFFECT. LAKE EFFECT SNOW SHOWERS SHOULD FINALLY WIND DOWN A BIT
THURSDAY NIGHT AS H8 TEMPS SLOWLY MODERATE. ONLY A SMALL CHANCE FOR
LIGHT SNOW SHOWERS FRIDAY SINCE BY THEN SFC WINDS SHOULD BECOME
EASTERLY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 327 AM EST WED DEC 11 2013
LIKELY POPS STILL LOOKS GOOD FOR SATURDAY AS THE 00Z GUIDANCE HAS
MAINTAINED CONTINUITY WITH THE LOW COMING OUT OF THE SOUTHERN
PLAINS. MID LEVEL F-GEN COULD BE STRONG ENOUGH TO PRODUCE MESOSCALE
BANDS OF LIGHT TO MODERATE SNOW FOR SEVERAL HOURS SATURDAY AFTERNOON
AND EVENING ACROSS CENTRAL AND SOUTHERN LOWER MICHIGAN.
THE LOW MOVES EAST SATURDAY NIGHT...BUT LOWER MICHIGAN REMAINS IN
THE TROWAL INTO SUNDAY. SO THE SNOW WILL LESSEN IN INTENSITY BUT NOT
END AS AN ARCTIC FRONT PROVIDES SFC CONVERGENCE INTO SUNDAY NIGHT.
SFC RIDGING SHOULD BUILD IN LATE SUNDAY NIGHT THEN RETURN FLOW
FOLLOWS FOR MONDAY IN ADVANCE OF NEXT CLIPPER. SNOW TAPERS OFF
MONDAY BEFORE WARM ADVECTION SNOWS BREAK OUT MONDAY NIGHT FOLLOWED
BY LAKE ENHANCED SNOW SHOWERS FOR TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1257 PM EST WED DEC 11 2013
WIDESPREAD LAKE EFFECT SNOW SHOWERS ARE DIMINISHING IN COVERAGE
AND INTENSITY EARLY THIS AFTERNOON...AND ARE EXPECTED TO CONTINUE
TO DO SO THE REST OF THE DAY. SOME POCKETS OF IFR WILL REMAIN
CLOSER TO THE LAKESHORE UNDER THE ISOLATED HEAVIER SNOW SHOWERS
STILL EXPECTED. THE REST OF THE AREA WILL SEE VFR/MVFR CONDITIONS
IN LESS COVERAGE OF SNOW SHOWERS.
LAKE EFFECT SNOW SHOWERS SHOULD MIGRATE BACK CLOSER TO THE
LAKESHORE TONIGHT BASED ON THE LATEST VISIBLE SATELLITE TRENDS. WE
ARE EXPECTING CLEARING TO TAKE PLACE INLAND...WITH LIGHT SNOW
SHOWERS ALONG THE LAKESHORE. MVFR WILL BE LIKELY ALONG THE
LAKESHORE AND MAINLY VFR INLAND.
SNOW SHOWERS WILL BEGIN TO PICK UP IN COVERAGE AND INTENSITY FOR A
FEW HOURS ON THU MORNING AS ANOTHER WAVE MOVES THROUGH. SNOW
SHOWERS WILL SPREAD INLAND ON W/SW FLOW AND DIURNAL PROCESSES.
MVFR CONDITIONS WILL BECOME DOMINANT WITH SOME IFR POSSIBLE NEAR
KMKG AND KGRR.
&&
.MARINE...
ISSUED AT 327 AM EST WED DEC 11 2013
A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR TODAY THROUGH EARLY
THURSDAY EVENING AS BRISK WEST NORTHWEST WINDS WILL RESULT IN WAVE
HEIGHTS GENERALLY AROUND 4 TO 7 FEET TODAY AND TONIGHT. WINDS
THURSDAY WILL BACK TO THE SOUTHWEST AT 15 TO 25 KNOTS RESULTING IN
CONTINUED SIGNIFICANT WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 327 AM EST WED DEC 11 2013
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE REST OF THE
WEEK AND WEEKEND ALONG WITH SEVERAL ROUNDS OF SNOW SHOWERS. THIS
COMBINATION OF SNOW AND COLD TEMPERATURES WILL RESULT IN POTENTIAL
FOR ICE JAM FORMATION. SO WE WILL CONTINUE TO MONITOR RIVER LEVELS
CLOSELY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...DUKE
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...NJJ
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1258 PM EST WED DEC 11 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 327 AM EST WED DEC 11 2013
COLD AND SNOWY WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK
AND WEEKEND. A BURST OF HEAVIER SNOW IS ON THE WAY TO AREAS NEAR TO
MAINLY SOUTH OF INTERSTATE 96 FROM AROUND DAYBREAK THROUGH THE REST
OF THE MORNING INTO THE EARLY TO MID AFTERNOON HOURS. ANOTHER BURST
OF HEAVIER LAKE EFFECT SNOW WILL OCCUR THURSDAY FROM HOLLAND
NORTHWARD AS WINDS BACK TO THE SOUTHWEST. LOW PRESSURE WILL BRING
MORE SNOW SATURDAY WITH SEVERAL MORE ROUNDS OF SNOW EXPECTED LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1131 AM EST WED DEC 11 2013
DROPPING MUSKEGON...OCEANA AND MASON FROM THE WINTER WEATHER
ADVISORY WITH THE REST REMAINING IN PLACE THROUGH THE AFTERNOON.
FEELING IS THE REMAINING COUNTIES WILL BE ABLE TO BE DROPPED IN
THE EARLY AFTERNOON AS WELL. WANT TO LET SOME OF THE HIGHER
REFLECTIVITIES DROP SOUTH OF THE AREA ASSOCIATED WITH THE BETTER
BANDING BEFORE ENDING IT. THAT WILL LIKELY TAKE PLACE IN THE 1-2 PM
TIME FRAME. ROADS ARE STILL NOT IN GOOD SHAPE GIVEN THE FINE SNOW
FLAKES LEADING TO FAIRLY GREASY ROADS THIS MORNING. ADVISORY IN
TERMS OF IMPACT SEEMED TO WORK OUT WELL GIVEN LIMITED VISIBILITIES
THIS MORNING AND POOR ROAD CONDITIONS. HIGHWAY 131 SOUTH OF GRAND
RAPIDS PER THE MDOT TRAVEL SPEEDS PAGE AS BEEN IMPACTED ALL
MORNING AND CONTINUES TO BE AFFECTED WITH A SECTION STILL SHUT
DOWN IT APPEARS. AGAIN...EARLY TO MID AFTERNOON FEEL WE WILL BE
ABLE TO END THE REMAINING PORTION OF THE WINTER WEATHER ADVISORY
EARLY. SOME LOCAL ACCUMULATIONS OF AN INCH OR SO WILL REMAIN
POSSIBLE THIS AFTERNOON. BEST CHANCE OF THIS OCCURRING THROUGH 00Z
WILL BE FROM OTTAWA COUNTY SOUTH DOWN THE SHORE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY AFTERNOON)
ISSUED AT 327 AM EST WED DEC 11 2013
A CONSENSUS OF HIGHER RESOLUTION SHORT RANGE GUIDANCE INCLUDING THE
RUC... HRRR AND 4KM WRF NMM ALL INDICATE THAT ANOTHER BURST OF
HEAVIER SNOW WILL DEVELOP NEAR TO MAINLY SOUTH OF INTERSTATE 96
DURING THE EARLY TO MID MORNING HOURS. THE HEAVIEST SNOW WILL LINGER
THROUGH AT LEAST EARLY AFTERNOON BEFORE TAPERING OFF. A COUPLE OF
UPPER LEVEL DISTURBANCES MOVING THROUGH LATER THIS MORNING INTO THE
AFTERNOON WILL ENHANCE THE SNOW WITH DEEP LOW TO MID LEVEL MOISTURE
IN PLACE THROUGH 18Z THIS AFTERNOON AND WITH H8 TEMPS WAY DOWN
AROUND -16 TO -18 C.
HEAVIEST SNOW FROM MID MORNING THROUGH EARLY TO MID AFTERNOON WILL
FALL MAINLY SOUTH OF I-96 WITH ABOUT 3 TO 5 INCHES OF SNOW EXPECTED
DOWN AROUND HASTINGS... ALLEGAN... SOUTH HAVEN AND KALAMAZOO. A
BUKFIT X-SECTION FOR SOUTH HAVEN SHOWS ABOUT 10 MICROBARS/SEC OF
LIFT LATE THIS MORNING WITH INVERSION HEIGHTS UP AROUND 8-9 KFT. OUR
ONGOING WINTER WEATHER HEADLINES LOOK EXCELLENT AND WILL REMAIN
UNCHANGED.
WNW TO WEST FLOW LES WILL CONTINUE TONIGHT WITH SUFFICIENT MOISTURE
STILL IN PLACE AND H8 TEMPS STILL DOWN AROUND -16 TO -18 C. THEN
WINDS WILL BACK TO THE WSW TO SW THURSDAY FAVORING AREAS FROM AROUND
BIV NORTHWARD OVER OUR NW FCST AREA TO RECEIVE SEVERAL INCHES OF
LAKE EFFECT. LAKE EFFECT SNOW SHOWERS SHOULD FINALLY WIND DOWN A BIT
THURSDAY NIGHT AS H8 TEMPS SLOWLY MODERATE. ONLY A SMALL CHANCE FOR
LIGHT SNOW SHOWERS FRIDAY SINCE BY THEN SFC WINDS SHOULD BECOME
EASTERLY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 327 AM EST WED DEC 11 2013
LIKELY POPS STILL LOOKS GOOD FOR SATURDAY AS THE 00Z GUIDANCE HAS
MAINTAINED CONTINUITY WITH THE LOW COMING OUT OF THE SOUTHERN
PLAINS. MID LEVEL F-GEN COULD BE STRONG ENOUGH TO PRODUCE MESOSCALE
BANDS OF LIGHT TO MODERATE SNOW FOR SEVERAL HOURS SATURDAY AFTERNOON
AND EVENING ACROSS CENTRAL AND SOUTHERN LOWER MICHIGAN.
THE LOW MOVES EAST SATURDAY NIGHT...BUT LOWER MICHIGAN REMAINS IN
THE TROWAL INTO SUNDAY. SO THE SNOW WILL LESSEN IN INTENSITY BUT NOT
END AS AN ARCTIC FRONT PROVIDES SFC CONVERGENCE INTO SUNDAY NIGHT.
SFC RIDGING SHOULD BUILD IN LATE SUNDAY NIGHT THEN RETURN FLOW
FOLLOWS FOR MONDAY IN ADVANCE OF NEXT CLIPPER. SNOW TAPERS OFF
MONDAY BEFORE WARM ADVECTION SNOWS BREAK OUT MONDAY NIGHT FOLLOWED
BY LAKE ENHANCED SNOW SHOWERS FOR TUESDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1257 PM EST WED DEC 11 2013
WIDESPREAD LAKE EFFECT SNOW SHOWERS ARE DIMINISHING IN COVERAGE
AND INTENSITY EARLY THIS AFTERNOON...AND ARE EXPECTED TO CONTINUE
TO DO SO THE REST OF THE DAY. SOME POCKETS OF IFR WILL REMAIN
CLOSER TO THE LAKESHORE UNDER THE ISOLATED HEAVIER SNOW SHOWERS
STILL EXPECTED. THE REST OF THE AREA WILL SEE VFR/MVFR CONDITIONS
IN LESS COVERAGE OF SNOW SHOWERS.
LAKE EFFECT SNOW SHOWERS SHOULD MIGRATE BACK CLOSER TO THE
LAKESHORE TONIGHT BASED ON THE LATEST VISIBLE SATELLITE TRENDS. WE
ARE EXPECTING CLEARING TO TAKE PLACE INLAND...WITH LIGHT SNOW
SHOWERS ALONG THE LAKESHORE. MVFR WILL BE LIKELY ALONG THE
LAKESHORE AND MAINLY VFR INLAND.
SNOW SHOWERS WILL BEGIN TO PICK UP IN COVERAGE AND INTENSITY FOR A
FEW HOURS ON THU MORNING AS ANOTHER WAVE MOVES THROUGH. SNOW
SHOWERS WILL SPREAD INLAND ON W/SW FLOW AND DIURNAL PROCESSES.
MVFR CONDITIONS WILL BECOME DOMINANT WITH SOME IFR POSSIBLE NEAR
KMKG AND KGRR.
&&
.MARINE...
ISSUED AT 327 AM EST WED DEC 11 2013
A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR TODAY THROUGH EARLY
THURSDAY EVENING AS BRISK WEST NORTHWEST WINDS WILL RESULT IN WAVE
HEIGHTS GENERALLY AROUND 4 TO 7 FEET TODAY AND TONIGHT. WINDS
THURSDAY WILL BACK TO THE SOUTHWEST AT 15 TO 25 KNOTS RESULTING IN
CONTINUED SIGNIFICANT WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 327 AM EST WED DEC 11 2013
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE REST OF THE
WEEK AND WEEKEND ALONG WITH SEVERAL ROUNDS OF SNOW SHOWERS. THIS
COMBINATION OF SNOW AND COLD TEMPERATURES WILL RESULT IN POTENTIAL
FOR ICE JAM FORMATION. SO WE WILL CONTINUE TO MONITOR RIVER LEVELS
CLOSELY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ056-
057-064>066-071>073.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...DUKE
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...NJJ
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
1139 AM EST WED DEC 11 2013
LATEST UPDATE...
UPDATE
.SYNOPSIS...
ISSUED AT 327 AM EST WED DEC 11 2013
COLD AND SNOWY WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK
AND WEEKEND. A BURST OF HEAVIER SNOW IS ON THE WAY TO AREAS NEAR TO
MAINLY SOUTH OF INTERSTATE 96 FROM AROUND DAYBREAK THROUGH THE REST
OF THE MORNING INTO THE EARLY TO MID AFTERNOON HOURS. ANOTHER BURST
OF HEAVIER LAKE EFFECT SNOW WILL OCCUR THURSDAY FROM HOLLAND
NORTHWARD AS WINDS BACK TO THE SOUTHWEST. LOW PRESSURE WILL BRING
MORE SNOW SATURDAY WITH SEVERAL MORE ROUNDS OF SNOW EXPECTED LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.UPDATE...
ISSUED AT 1131 AM EST WED DEC 11 2013
DROPPING MUSKEGON...OCEANA AND MASON FROM THE WINTER WEATHER
ADVISORY WITH THE REST REMAINING IN PLACE THROUGH THE AFTERNOON.
FEELING IS THE REMAINING COUNTIES WILL BE ABLE TO BE DROPPED IN
THE EARLY AFTERNOON AS WELL. WANT TO LET SOME OF THE HIGHER
REFLECTIVITIES DROP SOUTH OF THE AREA ASSOCIATED WITH THE BETTER
BANDING BEFORE ENDING IT. THAT WILL LIKELY TAKE PLACE IN THE 1-2 PM
TIME FRAME. ROADS ARE STILL NOT IN GOOD SHAPE GIVEN THE FINE SNOW
FLAKES LEADING TO FAIRLY GREASY ROADS THIS MORNING. ADVISORY IN
TERMS OF IMPACT SEEMED TO WORK OUT WELL GIVEN LIMITED VISIBILITIES
THIS MORNING AND POOR ROAD CONDITIONS. HIGHWAY 131 SOUTH OF GRAND
RAPIDS PER THE MDOT TRAVEL SPEEDS PAGE AS BEEN IMPACTED ALL
MORNING AND CONTINUES TO BE AFFECTED WITH A SECTION STILL SHUT
DOWN IT APPEARS. AGAIN...EARLY TO MID AFTERNOON FEEL WE WILL BE
ABLE TO END THE REMAINING PORTION OF THE WINTER WEATHER ADVISORY
EARLY. SOME LOCAL ACCUMULATIONS OF AN INCH OR SO WILL REMAIN
POSSIBLE THIS AFTERNOON. BEST CHANCE OF THIS OCCURRING THROUGH 00Z
WILL BE FROM OTTAWA COUNTY SOUTH DOWN THE SHORE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY AFTERNOON)
ISSUED AT 327 AM EST WED DEC 11 2013
A CONSENSUS OF HIGHER RESOLUTION SHORT RANGE GUIDANCE INCLUDING THE
RUC... HRRR AND 4KM WRF NMM ALL INDICATE THAT ANOTHER BURST OF
HEAVIER SNOW WILL DEVELOP NEAR TO MAINLY SOUTH OF INTERSTATE 96
DURING THE EARLY TO MID MORNING HOURS. THE HEAVIEST SNOW WILL LINGER
THROUGH AT LEAST EARLY AFTERNOON BEFORE TAPERING OFF. A COUPLE OF
UPPER LEVEL DISTURBANCES MOVING THROUGH LATER THIS MORNING INTO THE
AFTERNOON WILL ENHANCE THE SNOW WITH DEEP LOW TO MID LEVEL MOISTURE
IN PLACE THROUGH 18Z THIS AFTERNOON AND WITH H8 TEMPS WAY DOWN
AROUND -16 TO -18 C.
HEAVIEST SNOW FROM MID MORNING THROUGH EARLY TO MID AFTERNOON WILL
FALL MAINLY SOUTH OF I-96 WITH ABOUT 3 TO 5 INCHES OF SNOW EXPECTED
DOWN AROUND HASTINGS... ALLEGAN... SOUTH HAVEN AND KALAMAZOO. A
BUKFIT X-SECTION FOR SOUTH HAVEN SHOWS ABOUT 10 MICROBARS/SEC OF
LIFT LATE THIS MORNING WITH INVERSION HEIGHTS UP AROUND 8-9 KFT. OUR
ONGOING WINTER WEATHER HEADLINES LOOK EXCELLENT AND WILL REMAIN
UNCHANGED.
WNW TO WEST FLOW LES WILL CONTINUE TONIGHT WITH SUFFICIENT MOISTURE
STILL IN PLACE AND H8 TEMPS STILL DOWN AROUND -16 TO -18 C. THEN
WINDS WILL BACK TO THE WSW TO SW THURSDAY FAVORING AREAS FROM AROUND
BIV NORTHWARD OVER OUR NW FCST AREA TO RECEIVE SEVERAL INCHES OF
LAKE EFFECT. LAKE EFFECT SNOW SHOWERS SHOULD FINALLY WIND DOWN A BIT
THURSDAY NIGHT AS H8 TEMPS SLOWLY MODERATE. ONLY A SMALL CHANCE FOR
LIGHT SNOW SHOWERS FRIDAY SINCE BY THEN SFC WINDS SHOULD BECOME
EASTERLY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 327 AM EST WED DEC 11 2013
LIKELY POPS STILL LOOKS GOOD FOR SATURDAY AS THE 00Z GUIDANCE HAS
MAINTAINED CONTINUITY WITH THE LOW COMING OUT OF THE SOUTHERN
PLAINS. MID LEVEL F-GEN COULD BE STRONG ENOUGH TO PRODUCE MESOSCALE
BANDS OF LIGHT TO MODERATE SNOW FOR SEVERAL HOURS SATURDAY AFTERNOON
AND EVENING ACROSS CENTRAL AND SOUTHERN LOWER MICHIGAN.
THE LOW MOVES EAST SATURDAY NIGHT...BUT LOWER MICHIGAN REMAINS IN
THE TROWAL INTO SUNDAY. SO THE SNOW WILL LESSEN IN INTENSITY BUT NOT
END AS AN ARCTIC FRONT PROVIDES SFC CONVERGENCE INTO SUNDAY NIGHT.
SFC RIDGING SHOULD BUILD IN LATE SUNDAY NIGHT THEN RETURN FLOW
FOLLOWS FOR MONDAY IN ADVANCE OF NEXT CLIPPER. SNOW TAPERS OFF
MONDAY BEFORE WARM ADVECTION SNOWS BREAK OUT MONDAY NIGHT FOLLOWED
BY LAKE ENHANCED SNOW SHOWERS FOR TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM EST WED DEC 11 2013
MVFR AND IFR IN SNOW AND BLOWING SNOW THIS MORNING WILL IMPROVE TO
MVFR AND VFR BY 18Z FOR MOST PLACES. THE HEAVIER SNOW WILL BE
AROUND AZO WHERE IFR WILL BE PREVAILING MUCH OF THE MORNING. WINDS
WILL BE WEST AROUND 10 TO 15 KNOTS THIS MORNING GOING NORTHWEST
THIS AFTERNOON.
&&
.MARINE...
ISSUED AT 327 AM EST WED DEC 11 2013
A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR TODAY THROUGH EARLY
THURSDAY EVENING AS BRISK WEST NORTHWEST WINDS WILL RESULT IN WAVE
HEIGHTS GENERALLY AROUND 4 TO 7 FEET TODAY AND TONIGHT. WINDS
THURSDAY WILL BACK TO THE SOUTHWEST AT 15 TO 25 KNOTS RESULTING IN
CONTINUED SIGNIFICANT WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 327 AM EST WED DEC 11 2013
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE REST OF THE
WEEK AND WEEKEND ALONG WITH SEVERAL ROUNDS OF SNOW SHOWERS. THIS
COMBINATION OF SNOW AND COLD TEMPERATURES WILL RESULT IN POTENTIAL
FOR ICE JAM FORMATION. SO WE WILL CONTINUE TO MONITOR RIVER LEVELS
CLOSELY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ056-
057-064>066-071>073.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR LMZ844>849.
&&
$$
UPDATE...DUKE
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
644 AM EST WED DEC 11 2013
LATEST UPDATE...
AVIATION
.SYNOPSIS...
ISSUED AT 327 AM EST WED DEC 11 2013
COLD AND SNOWY WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK
AND WEEKEND. A BURST OF HEAVIER SNOW IS ON THE WAY TO AREAS NEAR TO
MAINLY SOUTH OF INTERSTATE 96 FROM AROUND DAYBREAK THROUGH THE REST
OF THE MORNING INTO THE EARLY TO MID AFTERNOON HOURS. ANOTHER BURST
OF HEAVIER LAKE EFFECT SNOW WILL OCCUR THURSDAY FROM HOLLAND
NORTHWARD AS WINDS BACK TO THE SOUTHWEST. LOW PRESSURE WILL BRING
MORE SNOW SATURDAY WITH SEVERAL MORE ROUNDS OF SNOW EXPECTED LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY AFTERNOON)
ISSUED AT 327 AM EST WED DEC 11 2013
A CONSENSUS OF HIGHER RESOLUTION SHORT RANGE GUIDANCE INCLUDING THE
RUC... HRRR AND 4KM WRF NMM ALL INDICATE THAT ANOTHER BURST OF
HEAVIER SNOW WILL DEVELOP NEAR TO MAINLY SOUTH OF INTERSTATE 96
DURING THE EARLY TO MID MORNING HOURS. THE HEAVIEST SNOW WILL LINGER
THROUGH AT LEAST EARLY AFTERNOON BEFORE TAPERING OFF. A COUPLE OF
UPPER LEVEL DISTURBANCES MOVING THROUGH LATER THIS MORNING INTO THE
AFTERNOON WILL ENHANCE THE SNOW WITH DEEP LOW TO MID LEVEL MOISTURE
IN PLACE THROUGH 18Z THIS AFTERNOON AND WITH H8 TEMPS WAY DOWN
AROUND -16 TO -18 C.
HEAVIEST SNOW FROM MID MORNING THROUGH EARLY TO MID AFTERNOON WILL
FALL MAINLY SOUTH OF I-96 WITH ABOUT 3 TO 5 INCHES OF SNOW EXPECTED
DOWN AROUND HASTINGS... ALLEGAN... SOUTH HAVEN AND KALAMAZOO. A
BUKFIT X-SECTION FOR SOUTH HAVEN SHOWS ABOUT 10 MICROBARS/SEC OF
LIFT LATE THIS MORNING WITH INVERSION HEIGHTS UP AROUND 8-9 KFT. OUR
ONGOING WINTER WEATHER HEADLINES LOOK EXCELLENT AND WILL REMAIN
UNCHANGED.
WNW TO WEST FLOW LES WILL CONTINUE TONIGHT WITH SUFFICIENT MOISTURE
STILL IN PLACE AND H8 TEMPS STILL DOWN AROUND -16 TO -18 C. THEN
WINDS WILL BACK TO THE WSW TO SW THURSDAY FAVORING AREAS FROM AROUND
BIV NORTHWARD OVER OUR NW FCST AREA TO RECEIVE SEVERAL INCHES OF
LAKE EFFECT. LAKE EFFECT SNOW SHOWERS SHOULD FINALLY WIND DOWN A BIT
THURSDAY NIGHT AS H8 TEMPS SLOWLY MODERATE. ONLY A SMALL CHANCE FOR
LIGHT SNOW SHOWERS FRIDAY SINCE BY THEN SFC WINDS SHOULD BECOME
EASTERLY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 327 AM EST WED DEC 11 2013
LIKELY POPS STILL LOOKS GOOD FOR SATURDAY AS THE 00Z GUIDANCE HAS
MAINTAINED CONTINUITY WITH THE LOW COMING OUT OF THE SOUTHERN
PLAINS. MID LEVEL F-GEN COULD BE STRONG ENOUGH TO PRODUCE MESOSCALE
BANDS OF LIGHT TO MODERATE SNOW FOR SEVERAL HOURS SATURDAY AFTERNOON
AND EVENING ACROSS CENTRAL AND SOUTHERN LOWER MICHIGAN.
THE LOW MOVES EAST SATURDAY NIGHT...BUT LOWER MICHIGAN REMAINS IN
THE TROWAL INTO SUNDAY. SO THE SNOW WILL LESSEN IN INTENSITY BUT NOT
END AS AN ARCTIC FRONT PROVIDES SFC CONVERGENCE INTO SUNDAY NIGHT.
SFC RIDGING SHOULD BUILD IN LATE SUNDAY NIGHT THEN RETURN FLOW
FOLLOWS FOR MONDAY IN ADVANCE OF NEXT CLIPPER. SNOW TAPERS OFF
MONDAY BEFORE WARM ADVECTION SNOWS BREAK OUT MONDAY NIGHT FOLLOWED
BY LAKE ENHANCED SNOW SHOWERS FOR TUESDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 643 AM EST WED DEC 11 2013
MVFR AND IFR IN SNOW AND BLOWING SNOW THIS MORNING WILL IMPROVE TO
MVFR AND VFR BY 18Z FOR MOST PLACES. THE HEAVIER SNOW WILL BE
AROUND AZO WHERE IFR WILL BE PREVAILING MUCH OF THE MORNING. WINDS
WILL BE WEST AROUND 10 TO 15 KNOTS THIS MORNING GOING NORTHWEST
THIS AFTERNOON.
&&
.MARINE...
ISSUED AT 327 AM EST WED DEC 11 2013
A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR TODAY THROUGH EARLY
THURSDAY EVENING AS BRISK WEST NORTHWEST WINDS WILL RESULT IN WAVE
HEIGHTS GENERALLY AROUND 4 TO 7 FEET TODAY AND TONIGHT. WINDS
THURSDAY WILL BACK TO THE SOUTHWEST AT 15 TO 25 KNOTS RESULTING IN
CONTINUED SIGNIFICANT WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 327 AM EST WED DEC 11 2013
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE REST OF THE
WEEK AND WEEKEND ALONG WITH SEVERAL ROUNDS OF SNOW SHOWERS. THIS
COMBINATION OF SNOW AND COLD TEMPERATURES WILL RESULT IN POTENTIAL
FOR ICE JAM FORMATION. SO WE WILL CONTINUE TO MONITOR RIVER LEVELS
CLOSELY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR MIZ037-
043-050-056-057-064>066-071>073.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...OSTUNO
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
327 AM EST WED DEC 11 2013
.SYNOPSIS...
ISSUED AT 327 AM EST WED DEC 11 2013
COLD AND SNOWY WEATHER WILL CONTINUE THROUGH THE REST OF THE WEEK
AND WEEKEND. A BURST OF HEAVIER SNOW IS ON THE WAY TO AREAS NEAR TO
MAINLY SOUTH OF INTERSTATE 96 FROM AROUND DAYBREAK THROUGH THE REST
OF THE MORNING INTO THE EARLY TO MID AFTERNOON HOURS. ANOTHER BURST
OF HEAVIER LAKE EFFECT SNOW WILL OCCUR THURSDAY FROM HOLLAND
NORTHWARD AS WINDS BACK TO THE SOUTHWEST. LOW PRESSURE WILL BRING
MORE SNOW SATURDAY WITH SEVERAL MORE ROUNDS OF SNOW EXPECTED LATE IN
THE WEEKEND INTO EARLY NEXT WEEK.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY AFTERNOON)
ISSUED AT 327 AM EST WED DEC 11 2013
A CONSENSUS OF HIGHER RESOLUTION SHORT RANGE GUIDANCE INCLUDING THE
RUC... HRRR AND 4KM WRF NMM ALL INDICATE THAT ANOTHER BURST OF
HEAVIER SNOW WILL DEVELOP NEAR TO MAINLY SOUTH OF INTERSTATE 96
DURING THE EARLY TO MID MORNING HOURS. THE HEAVIEST SNOW WILL LINGER
THROUGH AT LEAST EARLY AFTERNOON BEFORE TAPERING OFF. A COUPLE OF
UPPER LEVEL DISTURBANCES MOVING THROUGH LATER THIS MORNING INTO THE
AFTERNOON WILL ENHANCE THE SNOW WITH DEEP LOW TO MID LEVEL MOISTURE
IN PLACE THROUGH 18Z THIS AFTERNOON AND WITH H8 TEMPS WAY DOWN
AROUND -16 TO -18 C.
HEAVIEST SNOW FROM MID MORNING THROUGH EARLY TO MID AFTERNOON WILL
FALL MAINLY SOUTH OF I-96 WITH ABOUT 3 TO 5 INCHES OF SNOW EXPECTED
DOWN AROUND HASTINGS... ALLEGAN... SOUTH HAVEN AND KALAMAZOO. A
BUKFIT X-SECTION FOR SOUTH HAVEN SHOWS ABOUT 10 MICROBARS/SEC OF
LIFT LATE THIS MORNING WITH INVERSION HEIGHTS UP AROUND 8-9 KFT. OUR
ONGOING WINTER WEATHER HEADLINES LOOK EXCELLENT AND WILL REMAIN
UNCHANGED.
WNW TO WEST FLOW LES WILL CONTINUE TONIGHT WITH SUFFICIENT MOISTURE
STILL IN PLACE AND H8 TEMPS STILL DOWN AROUND -16 TO -18 C. THEN
WINDS WILL BACK TO THE WSW TO SW THURSDAY FAVORING AREAS FROM AROUND
BIV NORTHWARD OVER OUR NW FCST AREA TO RECEIVE SEVERAL INCHES OF
LAKE EFFECT. LAKE EFFECT SNOW SHOWERS SHOULD FINALLY WIND DOWN A BIT
THURSDAY NIGHT AS H8 TEMPS SLOWLY MODERATE. ONLY A SMALL CHANCE FOR
LIGHT SNOW SHOWERS FRIDAY SINCE BY THEN SFC WINDS SHOULD BECOME
EASTERLY.
.LONG TERM...(FRIDAY NIGHT THROUGH TUESDAY)
ISSUED AT 327 AM EST WED DEC 11 2013
LIKELY POPS STILL LOOKS GOOD FOR SATURDAY AS THE 00Z GUIDANCE HAS
MAINTAINED CONTINUITY WITH THE LOW COMING OUT OF THE SOUTHERN
PLAINS. MID LEVEL F-GEN COULD BE STRONG ENOUGH TO PRODUCE MESOSCALE
BANDS OF LIGHT TO MODERATE SNOW FOR SEVERAL HOURS SATURDAY AFTERNOON
AND EVENING ACROSS CENTRAL AND SOUTHERN LOWER MICHIGAN.
THE LOW MOVES EAST SATURDAY NIGHT...BUT LOWER MICHIGAN REMAINS IN
THE TROWAL INTO SUNDAY. SO THE SNOW WILL LESSEN IN INTENSITY BUT NOT
END AS AN ARCTIC FRONT PROVIDES SFC CONVERGENCE INTO SUNDAY NIGHT.
SFC RIDGING SHOULD BUILD IN LATE SUNDAY NIGHT THEN RETURN FLOW
FOLLOWS FOR MONDAY IN ADVANCE OF NEXT CLIPPER. SNOW TAPERS OFF
MONDAY BEFORE WARM ADVECTION SNOWS BREAK OUT MONDAY NIGHT FOLLOWED
BY LAKE ENHANCED SNOW SHOWERS FOR TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1145 PM EST TUE DEC 10 2013
SNOW WILL INCREASE IN COVERAGE AND INTENSITY LATE TONIGHT AS A
WAVE OF LOW PRESSURE APPROACHES. MANY SITES ARE TO GO DOWN TO IFR
OR LOWER DUE TO LOW CEILINGS AND VISIBILITIES. DURING THE LATE
MORNING AND THROUGH THE AFTERNOON...THE SNOW BANDS WILL SHIFT
SOUTH AS THE WINDS VEER WITH TIME...BECOMING NORTHWEST BY LATE IN
THE DAY. A TREND TOWARD VFR IS EXPECTED.
&&
.MARINE...
ISSUED AT 327 AM EST WED DEC 11 2013
A SMALL CRAFT ADVISORY HAS BEEN ISSUED FOR TODAY THROUGH EARLY
THURSDAY EVENING AS BRISK WEST NORTHWEST WINDS WILL RESULT IN WAVE
HEIGHTS GENERALLY AROUND 4 TO 7 FEET TODAY AND TONIGHT. WINDS
THURSDAY WILL BACK TO THE SOUTHWEST AT 15 TO 25 KNOTS RESULTING IN
CONTINUED SIGNIFICANT WAVE ACTION.
&&
.HYDROLOGY...
ISSUED AT 327 AM EST WED DEC 11 2013
TEMPERATURES WILL REMAIN WELL BELOW NORMAL THROUGH THE REST OF THE
WEEK AND WEEKEND ALONG WITH SEVERAL ROUNDS OF SNOW SHOWERS. THIS
COMBINATION OF SNOW AND COLD TEMPERATURES WILL RESULT IN POTENTIAL
FOR ICE JAM FORMATION. SO WE WILL CONTINUE TO MONITOR RIVER LEVELS
CLOSELY.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY UNTIL 5 PM EST TODAY FOR MIZ037-043-
050-056-057-064-071.
WINTER WEATHER ADVISORY UNTIL 5 PM EST TODAY FOR MIZ065-066-
072-073.
LM...SMALL CRAFT ADVISORY UNTIL 7 PM EST THURSDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...LAURENS
SHORT TERM...LAURENS
LONG TERM...OSTUNO
AVIATION...MJS
HYDROLOGY...LAURENS
MARINE...LAURENS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1227 AM EST WED DEC 11 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 447 PM EST TUE DEC 10 2013
MAIN FCST CONCERN IN THE SHORT TERM REVOLVES AROUND LES TRENDS AS
REINFORCING ARCTIC AIR MASS PASSES ACROSS THE AREA.
WATER VAPOR IMAGERY AND RUC ANALYSIS SHOW AN EXPANSIVE POLAR VORTEX
CENTERED OVER HUDSON BAY. WITHIN THE CIRCULATION...ONE SHORTWAVE HAS
MOVED E OF UPPER MI/LAKE SUPERIOR. WAVE BROUGHT A PERIOD OF -SN WITH
VERY LITTLE ACCUMULATION ACROSS MAINLY SRN AND ERN UPPER MI EARLIER
TODAY. THE SMALL SNOWFLAKES WERE EXCELLENT VIS RESTRICTORS.
UPSTREAM...ANOTHER SHORTWAVE WAS SWINGING THRU SRN MANITOBA/ND/NRN
MN. TYPICAL FOR ARCTIC AIR MASSES...IN THE WAKE OF THE FIRST
SHORTWAVE...SKIES GENERALLY CLEARED OUT AWAY FROM LAKE EFFECT AREAS.
PER VIS SATELLITE IMAGERY...SFC TROF/WIND SHIFT ACROSS LAKE SUPERIOR
HAS LEAD TO A BAND OF HVY LES THAT HAS SETTLED S ACROSS THE KEWEENAW
TODAY. BAND IS A LITTLE MORE DISORGANIZED NOW...AND EXTENDS E ACROSS
ERN LAKE SUPERIOR PER SATELLITE/KMQT RADAR IMAGERY.
AS NEXT SHORTWAVE MOVES ACROSS THE AREA TONIGHT...MODELS ARE NOT
INDICATING MUCH IN THE WAY OF FORCING PER QVECTORS...PROBABLY DUE TO
CAA AT LOW-LEVELS. NONETHELESS...CONDITIONS ARE FAVORABLE FOR
MDT/HVY LES AS INVERSIONS ARE UP AROUND 8KFT. NEGATIVE FACTOR WILL
BE THE COLD AIR SUPPRESSING THE DGZ...MAINLY OVER THE W WHERE
SHORTER FETCH LEADS TO LESS LAKE MODERATION/WARMING OF THE
LOW-LEVELS. HAVE SOME CONCERN THAT SNOWFLAKES MAY END UP QUITE
SMALL...KEEPING ACCCUMULATIONS LOWER THAN FCST. ON THE OTHER
HAND...THE SMALL SNOWFLAKES CREATE MORE OF A DRIVING HAZARD DUE TO
THEIR EFFECTIVENESS AT REDUCING VIS. IN ANY EVENT...ADVYS REMAIN
UP FOR THE WRN COUNTIES. HEAVIEST SNOW SHOULD FOCUS ACROSS NRN
ONTANAGON COUNTY INTO CNTRL HOUGHTON COUNTY...WHERE LOW-LEVEL
CONVERGENCE WILL BE ESPECIALLY STRONG THRU THE EVENING.
OVER THE E...NOT ONLY DOES A LONGER FETCH AND HIGHER DGZ POINT
TOWARD MORE SIGNIFICANT ACCUMULATIONS...BUT THERE ARE INDICATIONS
FROM ALL HIGH RES MODEL GUIDANCE FOR ONE OR TWO AREAS OF STRONGLY
FOCUSED CONVERGENCE OWING TO LAND BREEZES OFF ONTARIO AND NCNTRL
UPPER MI. EXACTLY WHERE THE CONVERGENCE ZONES SET UP AND WHETHER
THEY REMAIN STATIONARY OR MEANDER WILL CONTROL HOW MUCH SNOW FALLS.
PERUSAL OF A NUMBER OF HIGH RES MODELS SHOW WATER EQUIVALENT PCPN
TOTALS ANYWHERE FROM 1.5 TO 3.5 INCHES AIMING TOWARD WHITEFISH PT
VCNTY BY WED EVENING. IF SNOW RATIOS END UP AROUND 20 TO 1...YOU END
UP WITH A RIDICULOUS POTENTIAL SNOW ACCUMULATION. HOW THE EXPECTED
BAND OR BANDS SETUP TONIGHT WILL SET THE STAGE FOR WHETHER OR NOT
THE POTENTIAL SNOW ACCUMULATION IS REALIZED SOMEWHERE OVER NE UPPER
MI. OTHERWISE...OVERALL MODEL TREND SUGGESTS A LITTLE MORE NORTHERLY
COMPONENT TO THE WIND...SO ADVY WAS EXPANDED TO NRN SCHOOLCRAFT
COUNTY AND HEAVIER SNOW AMOUNTS WERE SPREAD A LITTLE FARTHER W IN
ALGER COUNTY...THOUGH HEAVIEST SNOW BANDS SHOULD STILL END UP E OF
MUNISING.
ONLY OTHER ITEM OF NOTE TONIGHT WAS INCLUSION OF LOW WIND CHILLS IN
HEADLINE PRODUCTS OVER WRN UPPER MI...INCLUDING WIND CHILL ADVY FOR
IRON COUNTY WHICH WAS NOT UNDER HEADLINE INVOLVING SNOW.
ON WED...LES WILL TREND LIGHTER OVER THE W AS INVERSIONS FALL A BIT.
LES SHOULD REMAIN QUITE HEAVY OVER THE E...ESPECIALLY DURING THE
MORNING WHEN CONVERGENCE REMAINS STRONG.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 410 PM EST TUE DEC 10 2013
LOOK FOR A SERIES OF SYSTEMS TO SLIDE IN ON THE NW FLOW
ALOFT...KEEPING SNOW IN THE FCST FOR MUCH OF THE PERIOD. IT WILL BE
A PERIOD OF ALMOST CONTINUOUS SFC TROUGHS OVER CENTRAL AND EASTERN
UPPER MI. THE BUFKIT TIME HEIGHT/OVERVIEW DATA FROM THE GFS AT CMX
LOOKS IMPRESSIVE. ALTHOUGH SNOW AMOUNTS ARE RELATIVELY
MINIMAL...THERE IS NEARLY CONSTANT SNOW FCST THROUGH 06Z MONDAY.
THE PERSISTENT 500MB TROUGH OVER EASTERN CANADA AND THE EAST HALF OF
THE UNITED STATES WILL STILL BE IN PLACE WEDNESDAY NIGHT. EVEN OVER
THE W HALF OF THE NATION THE SIZABLE RIDGE EXTENDING UP THROUGH THE
CASCADES WILL BE UNDERMINED BY CLOSED LOW SPINNING ACROSS S CA
WEDNESDAY NIGHT THROUGH THURSDAY. EXPECT NW FLOW ALOFT THROUGH THE
END OF THE WORK WEEK. THE MODELS SPREAD FOR TEMPERATURES FRIDAY
AFTERNOON ARE ALL OVER THE PLACE...RANGING FROM AROUND 6 TO 23 NEAR
THE WI BORDER. WENT WITH A MIDDLE OF THE ROAD FCST FOR NOW WITH
HIGHS IN THE TEENS CWA WIDE...AND WILL FINE-TUNE IT AS THE TIME
NEARS.
BY 00Z SATURDAY THE MAIN LOW WILL HAVE MOVED FROM HUDSON BAY TO
CENTRAL QUEBEC...SLOWLY MARKING THE END TO ITS DOMINANCE. WHILE SOME
IMPROVEMENT IN THE FRIGGED TEMPERATURES OF LATE FRIDAY INTO
SATURDAY...WE WILL STILL END UP WELL BELOW THE NORMAL HIGH TEMPS FOR
THIS TIME OF YEAR...WHICH MAY TYPICALLY RISE INTO THE MID TO UPPER
20S.
THE NEXT QUICK MOVING WAVE IN THE 500MB NW FLOW OVER N SASKATCHEWAN
AND MANITOBA AT 06Z SATURDAY WILL PUSH ACROSS THE UPPER GREAT LAKES
LATE SATURDAY NIGHT THROUGH SUNDAY.
EXPECT BRIEF RIDGING ALOFT SUNDAY NIGHT INTO MONDAY TO BECOME
SUPPRESSED AHEAD OF THE NEXT TROUGH NEARING FROM THE NORTHWEST. THE
BEST CHANCE FOR SHORT LIVED CWA-WIDE HIGH PRESSURE AT THE SFC WILL
BE SUNDAY NIGHT. THIS WILL BE THE ONLY PERIOD WITH SLIGHT CHANCE
POPS OR LESS ACROSS THE AREA. THE TROUGH TO THE NORTHWEST WILL
LIKELY SWING ACROSS THE UPPER GREAT LAKES MONDAY...AND LINGER
THROUGH TUESDAY...AS LES PICKS UP AGAIN ACROSS THE KEWEENAW
PENINSULA. THE GFS AND ECMWF HAD VERY SIMILAR TIMING ON THE SFC
LOW...SET UP ACROSS CENTRAL LAKE SUPERIOR AND EASTERN ONTARIO AT 18Z
TUESDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1225 AM EST WED DEC 11 2013
KIWD...EXPECT MVFR CONDITIONS TO LAST THROUGH WED EVENING WITH LAKE
EFFECT SNOW SHOWERS CONTINUING. AS WINDS BECOME MORE SW BY WED
EVENING...LAKE CLOUDS WILL PUSH NORTH AND CONDITIONS WILL BE VFR.
KCMX...EXPECT IFR TO LIFR CONDITIONS THROUGH THE FORECAST PERIOD
WITH LAKE EFFECT SNOW BANDS PASSING THROUGH. WITH GUSTY WINDS...THE
BLOWING SNOW WILL BE THE MAIN FACTOR IN THE LOWER VISIBILITIES.
KSAW...VFR CONDITIONS WILL CONTINUE THRU THE FORECAST PERIOD.
DOWNSLOPE NATURE OF THE W WIND AND RELATIVE DRYNESS OF THE AIRMASS
SHOULD MAINTAIN THE VFR WX AT THIS SITE EVEN IF SOME FLURRIES MAKE
IT INTO THE AREA WED MORNING.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 410 PM EST TUE DEC 10 2013
FREEZING SPRAY AND GALES TO 35-40KTS WILL BE THE MAIN
CONCERNS...COMING TO AN END WEDNESDAY NIGHT. HIGH PRESSURE OVER W
CANADA WILL DRIFT SE THROUGH THURSDAY NIGHT. EXPECT A TROUGH TO
LINGER OVER THE UPPER GREAT LAKES DURING THE SAME TIME PERIOD.
ANOTHER HIGH CENTERED OVER CENTRAL CANADA WILL THEN SLIDE ACROSS
ONTARIO ON FRIDAY...AND INTO QUEBEC ON SATURDAY. ALSO FRIDAY INTO
SATURDAY...A LOW WILL ORGANIZE ACROSS THE MID MISSISSIPPI VALLEY.
THE LOW WILL SHIFT INTO THE NE STATES SUNDAY...WITH A TROUGH
LINGERING OVER THE UPPER GREAT LAKES...AS HIGH PRESSURE SLIDES
ACROSS MANITOBA.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 5 PM EST THIS AFTERNOON FOR
MIZ004-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ085.
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ002-
003-006.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST THIS MORNING FOR MIZ001.
LAKE EFFECT SNOW ADVISORY UNTIL 11 AM CST WEDNESDAY FOR MIZ009.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THURSDAY FOR MIZ007.
WIND CHILL ADVISORY UNTIL 11 AM CST WEDNESDAY FOR MIZ010.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 6 PM EST THIS EVENING FOR
LSZ266.
HEAVY FREEZING SPRAY WARNING UNTIL 6 AM EST /5 AM CST/ THURSDAY
FOR LSZ162-240>245-248>251-263>265.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING UNTIL 6 AM EST EARLY THIS MORNING
FOR LMZ221-248-250.
&&
$$
SHORT TERM...ROLFSON
LONG TERM...KF
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
947 PM CST Thu Dec 12 2013
.UPDATE...
Issued at 947 PM CST THU DEC 12 2013
Near term forecast updated to account for rather wild fluctuations
in hourly temperatures. Snow cover, wind and incoming clouds will
continue to play havoc with temperatures the rest of tonight.
Concerning the forecast for tomorrow, incoming NAM and latest
RUC/HRRR suggest that precipitation onset may be delayed a few
hours Friday morning as compared to the going forecast. The very
dry 00 UTC raobs from KSGF/KLZK/KSHV/KOUN do lend credence to a
slightly slower onset. The NAM and RUC continue to be more
aggressive with the warm nose with this system versus its global
model (GFS/Euro/GEM) counterparts. With such a dry airmass in
place will come rather substantial wet bulbing potential, thus am
not buying off on the strength of the warm nose in the NAM/RUC.
Thus, other than a slight delay in onset, precipitation type
expectations have not changed. Snow, sleet and rain/freezing rain
(dependent upon surface temperatures) are all plausible Friday
and Friday night. Surface temperatures will remain very, very
tricky tomorrow. Again, wet bulbing will have a big affect on
readings through at least the morning hours. Most locations will
be a few degrees either side of the freezing mark, with localized
cooler spots in the area terrain. Full forecast update will be
provided when GFS/Euro/GEM are available for investigation.
&&
.SHORT TERM...(This Evening through Saturday)
Issued at 245 PM CST THU DEC 12 2013
A complex forecast the next 48 hours as a storm system tracks
across the region bringing a wintry mix.
A shortwave trough now over the Baja California region will track
northeast toward the Ozarks Friday. Clouds will be on the increase
later tonight as the associated moisture plume streams
northeastward.
A jet streak and accompanying lead disturbance will impact the
region beginning Friday morning. The Ozarks will become favorably
positioned within a coupled jet structure to promote strengthening
synoptic scale lift. This will result in a rapid development and
expansion of precipitation as early as day break and more so
during the morning hours Friday.
Progged low level thermal profiles suggest that precipitation
will begin as a wintry mix in the form of freezing rain and sleet.
Existing cold surfaces and potential of moderate precipitation
rates will likely lead to rapid deterioration of road conditions
Friday morning.
Temperatures will slowly rise Friday with readings rising above
the freezing mark from southwest to northeast. Most locations west
of Highway 65 will rise above freezing by midday while freezing
temperatures and wintry mix linger into at least early afternoon
east of Highway 65 into the eastern Ozarks. Just how long
temperatures remain below freezing will have to monitored closely.
The uncertainty on the exact precipitation type and duration lead
to questions on the exact amount of ice accumulation. At this time
generally expect a few hundredths to near one tenth of an inch ice
accretion.
The shortwave trough will push across the region Friday night
bringing a continuation and even an increase in precipitation
Friday evening. Meanwhile temperatures will slowly settle back
down toward freezing. Expect a wintry mix to expand across the
eastern Ozarks and also spread south across the remainder of the
area. Expect precipitation to transition to a mix of snow and sleet
before diminishing later Friday night. Light snow accumulations are
expected Friday night mainly across central Missouri and the
eastern Ozarks where an inch or two of snow accumulation is
expected.
Areas and perhaps widespread freezing drizzle is expected to develop
late Friday night into Saturday morning. This could result
hazardous travel conditions through Saturday morning.
Temperatures will rise little Saturday with all precipitation
ending during the afternoon.
With the expectation of winter precipitation a Winter Weather
Advisory will be issued from Friday morning into Friday night for
most of the Missouri Ozarks generally east of Interstate 49. The
most impacted area from this event will be along and east of the
Highway 65 corridor. Exact ice and snow accumulations remain
somewhat uncertain and the latest weather information should be
monitored.
.LONG TERM...(Saturday Night through Thursday)
Issued at 230 PM CST THU DEC 12 2013
A Canadian surface high pressure will move in for Saturday night
into early Sunday morning. Temperatures will be coldest with lows
down into the middle to upper teens especially over the higher
terrain of the Ozark Plateau and if any snow cover still remains
on the ground by that time.
Southerly to southwesterly winds will begin on Sunday on the
backside of the surface high. Sunday will remain chilly and below
average but sunny. Temperatures will rebound nicely by the early
part of next week back to more seasonable weather. The upper level
flow will try to flatten somewhat for the middle of next week.
Another weak and dry front will pass through early on Tuesday but
no real temperatures differences expected on either side of the
boundary. A dry and seasonable weather looks to stay around for
the early and middle portion of next week with possibly some
significant weather changes just beyond the 7 days toward the end
of next week.
&&
.AVIATION...(For the 00Z TAFS through 00Z Friday Evening)
Issued at 542 PM CST THU DEC 12 2013
Very messy and complex forecast for the next 24 hours and beyond.
Please refer to the short range discussion aloft for the explicit
details regarding the dynamics of this system and the temperature
profiles that will dictate a variety of precipitation types. The
forecast bottom line is that conditions will remain quiet through
tonight. Precipitation will move in from the southwest during the
daylight hours of Friday morning and continue in an on again/off
again fashion through Friday night. All precipitation types are
possible tomorrow...starting at a mix of freezing rain/sleet/snow
changing to rain/sleet/snow as surface temperatures rise above
freezing by a few degrees. Any flight restrictions will initially
be tied to visibility (MVFR). As the afternoon progresses,
ceilings will lower to low end MVFR. IFR is more likely just
beyond the TAF cycle.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY from 6 AM Friday to 6 AM CST Saturday
FOR MOZ055>058-066>071-077>083-089>092-094>098-102>106.
KS...NONE.
&&
$$
UPDATE...Gagan
SHORT TERM...Foster
LONG TERM...Griffin
AVIATION...Gagan
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
909 AM MST WED DEC 11 2013
.UPDATE...
NO SIGNIFICANT CHANGES TO THE FORECAST THIS MORNING. SHOULD BE
MAINLY DRY THROUGH AT LEAST THURSDAY. MAIN WEATHER IMPACT WILL BE
WIND IN THE WESTERN ZONES THE NEXT COUPLE OF DAYS. THIS IS
ALREADY HANDLED WELL BY THE WIND ADVISORY. I DID BUMP UP GUSTS FOR
AREAS AROUND WHEATLAND COUNTY BASED ON RAP MODEL GUIDANCE AND
CURRENT OBSERVATIONS. BT
&&
.SHORT TERM...VALID FOR TDY AND THU...
A REAL WARMING TREND IS IN STORE THE NEXT TWO DAYS UNDER NORTHWEST
FLOW ALOFT...BUT WINDS WILL REMAIN AN ISSUE IN SOUTH CENTRAL MT.
WARM AIR ADVECTION WILL BE ONGOING ALOFT THE NEXT 36 HOURS WITH AN
850-HPA THERMAL RIDGE OF +6 C OVER CENTRAL MT BY THU AFTERNOON. WE
EXPECT MUCH OF THIS WARM AIR TO GO TO WASTE WITH AN EXPANSIVE SNOW
FIELD APT TO LIMIT LOW-LEVEL MIXING...ESPECIALLY IN RIVER VALLEYS.
FORECAST SOUNDINGS BOTH TODAY AND THU SUGGEST MIXING COULD BE HELD
CLOSE TO 1000 FT AGL. EVEN SO...BY THU THE AIR MASS IS WARM ENOUGH
TO YIELD TEMPERATURES WELL INTO THE 30S F IN MOST PLACES EVEN WITH
THAT SHALLOW MIXING. FORECAST HIGHS TODAY AND THU ARE MAINLY BASED
ON THE GUIDANCE WHICH HAS BEEN PERFORMING WELL OVER THE LAST SEVEN
DAYS WHEN OUR SNOW FIELD HAS BEEN IN PLACE...WITH WEIGHTING TOWARD
THE 00 UTC GEM NUMBERS. THERE IS NONETHELESS LOTS OF POTENTIAL FOR
HIGHS TO BE EITHER MUCH WARMER OR COLDER THAN EXPECTED IN SPOTS IF
MIXING IS EITHER DEEPER OR EVEN MORE SHALLOW THAN ANTICIPATED.
AS FAR AS WINDS ARE CONCERNED...A WIND ADVISORY CONTINUES UNTIL 15
UTC FRI FOR THE LIVINGSTON AND NYE AREAS AS A 15 TO 20 HPA SURFACE
PRESSURE GRADIENT WILL EXIST BETWEEN IDAHO FALLS AND LEWISTOWN FOR
MUCH OF THE TIME THROUGH THU NIGHT. WE BELIEVE THE PEAK WINDS WILL
BE TONIGHT WHEN THE GRADIENT IS ESPECIALLY TIGHT AND THE STABILITY
AT MOUNTAIN-TOP LEVEL IS GREATEST. AN UPGRADE TO HIGH WIND WARNING
IS NOT OUT OF THE QUESTION WITH A LATER FORECAST. IN CONTRAST...IT
LOOKS LIKE WINDS MAY START RELAXING THU AFTERNOON AND THU NIGHT AS
SURFACE PRESSURE FALLS BEGIN IN EARNEST OVER SOUTHEAST ID AND OVER
YELLOWSTONE PARK AND AS MID-LEVEL COOLING BEGINS AT LIVINGSTON THU
EVENING. LEE-SIDE PRESSURE FALLS WILL ALSO SUPPORT GUSTY WINDS FOR
THE PLAINS OF SOUTH CENTRAL MT...AND A LOCAL ENHANCEMENT IS LIKELY
NEAR YELLOWTAIL DAM IN THIS PATTERN...WHERE GUSTS TO 55 MPH SHOULD
BE AN EASY ACHIEVEMENT BASED ON CLIMATOLOGY AND 00 UTC NAM OUTPUT.
FINALLY...WE ARE MENTIONING AT LEAST PATCHY BLOWING SNOW TODAY AND
TONIGHT IN PLACES OVER SOUTH CENTRAL MT WITH GUSTY WINDS. SCHULTZ
.LONG TERM...VALID FOR FRI...SAT...SUN...MON...TUE...
FRIDAY WILL BE A COOLER DAY AS A CLIPPER SYSTEM MOVES THROUGH THE
DAKOTAS PUSHING THE ARCTIC BACK INTO THE AREA AND LESS DOWNSLOPE
ACROSS THE WESTERN ZONES. MODELS DIFFER A BIT IN HOW FAR WEST THE
COLD AIR WILL COME SO LIMITED A REAL COOL DOWN INTO THE EASTERN
AREAS. THERE WILL BE A THREAT OF SHOWERS MAINLY FOR OROGRAPHIC
MOUNTAINS AS THE FLOW ALOFT INCREASES MOISTURE AND CANNOT RULE OUT
SOME LIGHT SNOW WITH THE BACKDOOR FRONT.
LEESIDE TROF BEGINS TO REBUILD ON SATURDAY AS THE DEEPEST COLD AIR
HEADS INTO THE MIDWEST. THIS ALLOWS THE ARCTIC TO RETREAT AND
BETTER MIXING ACROSS THE WESTERN ZONES. MODELS ALSO TEMPORARILY
DRY OUT THE FLOW ALOFT SO SHOULD SEE LESS SHOWER ACTIVITY WITH
DOWNSLOPE DEFEATING SHOWERS IN THE CENTRAL ZONES. HEIGHTS BUILDING
OVER SOUTHWESTERN PORTIONS OF THE US STRENGTHEN SURFACE HIGH
PRESSURE WEST OF THE DIVIDE ON SUNDAY WHICH WILL BRING AN
INCREASING THREAT OF GAP FLOW WINDS. THIS WINDIER AND DRY PATTERN
STARTING ON SUNDAY KEEPS GOING INTO MONDAY AND TUESDAY BEFORE A
CHANGE OCCURS SOMETIME IN THE WEDNESDAY TO FRIDAY TIMEFRAME. BOTH
ECMWF AND A SERIES OF GFS RUNS ARE ADVERTISING A STRONG ARCTIC
INTRUSION WITH A FAVORABLE FLOW ALOFT TO GENERATE SNOWFALL. TIMING
VARIES BY 36 HOURS BETWEEN THE MODELS BUT THE MAIN MESSAGE IS THE
DEEP CHILL AND MORE SNOW SHOULD BE EXPECTED LATTER HALF OF NEXT
WEEK. BORSUM
&&
.AVIATION...
STRONG...GUSTY SW WINDS WILL IMPACT KLVM AND OTHER LOCATIONS
ALONG THE WESTERN FOOTHILLS. THESE WINDS WILL GENERATE AREAS OF
BLOWING SNOW REDUCING VISIBILITY TO MVFR LOCALLY AT TIMES.
OTHERWISE...VFR CONDITIONS ARE EXPECTED ACROSS THE REST OF THE
REGION INTO TONIGHT. STC
&&
.PRELIMINARY POINT TEMP/POPS...
TDY THU FRI SAT SUN MON TUE
-------------------------------------------------------
BIL 028 021/037 021/033 017/032 025/037 022/033 017/033
0/N 00/N 12/J 11/E 11/B 10/B 11/B
LVM 029 022/039 020/037 021/035 024/035 021/032 020/031
1/Q 11/N 22/W 12/J 21/N 21/N 11/B
HDN 028 016/035 018/034 014/029 022/035 020/034 016/030
1/B 00/B 12/J 12/J 11/B 10/B 11/B
MLS 024 013/033 013/022 012/021 012/031 020/033 014/025
0/B 11/B 13/J 11/E 32/J 22/J 11/B
4BQ 027 013/036 014/028 014/026 017/032 020/033 015/027
0/B 00/B 02/J 12/J 22/J 11/B 11/B
BHK 022 010/031 008/020 012/016 008/026 018/030 012/023
0/B 11/B 13/J 11/E 33/J 12/J 11/B
SHR 030 015/041 014/033 016/033 018/036 020/034 016/031
1/U 10/B 13/J 12/J 11/B 21/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WIND ADVISORY IN EFFECT UNTIL 8 AM MST FRIDAY FOR ZONES
65-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1125 AM CST WED DEC 11 2013
.UPDATE...
ISSUED AT 647 AM CST WED DEC 11 2013
ONLY MADE SOME VERY MINOR TWEAKS FOR THE LATEST UPDATE. AFTER
BRINGING THE LATEST TEMPS/DEWPOINTS IN LINE WITH CURRENT
OBS AND PERUSING LATEST SETS OF MODEL DATA...OPTED TO MAKE A
VERY MINOR...ACROSS-THE-BOARD 1 DEGREE DROP IN HIGHS TODAY VERSUS
EARLIER FORECAST. IN OTHER WORDS...A TAD BIT MORE OF MAINLY THE
NORTHEAST CWA IS NOW AIMED TO FALL SHORT OF 20. ALSO BUMPED UP SKY
COVER INTO PARTLY CLOUDY TERRITORY FOR A TIME THIS MORNING IN FAR
SOUTHERN ZONES TO ACCOUNT FOR EAST-WEST-BAND OF CIRRUS THAT IS
CENTERED JUST SOUTH OF THE CWA. OTHERWISE...SMALL SPLOTCHES OF
LOW STRATUS CONTINUE TO DRIFT ACROSS LIMITED PARTS OF BOTH THE
WESTERN/EASTERN CWA...AND AS EVIDENCED BY THE OB AT HEBRON A
LITTLE WHILE AGO...SOME ROGUE/BRIEF FLURRIES CANNOT BE RULED OUT
WHEREVER THESE CLOUDS HAPPEN TO BE. AS DETAILED IN THE EARLIER
DISCUSSION...DAY SHIFT WILL HAVE TO KEEP AN EYE ON STRATUS TRENDS
OVER WESTERN NEB...JUST IN CASE SOME OF THIS STARTS TO EXPAND BACK
EASTWARD INTO THE WESTERN/NORTHWEST CWA LATER TODAY AS HINTED BY
THE LATEST RAP13 900MB RELATIVE HUMIDITY FORECAST. THIS IS NO SURE
THING THOUGH...AS THE LATEST HRRR KEEPS SKIES CLEAR PER ITS LOW
LEVEL CLOUD COVER PRODUCT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM CST WED DEC 11 2013
IN THE MIDST OF THE MODEST TEMPERATURE-ROLLER COASTER WE ARE NOW
RIDING...TODAY STILL LOOKS LIKE THE OVERALL-COLDEST DAY OUT OF THE
NEXT 7...AS WE CATCH THE WESTERN EDGES OF A GLANCING BLOW OF
ARCTIC AIR THAT IS PRIMARILY PASSING NORTHEAST OF THE AREA. GIVEN
THAT THERE IS ESSENTIALLY ZERO RISK OF PRECIP DURING THE NEXT 24
HOURS...TEMPS CONTINUE TO BE THE MAIN ISSUE...AND AGAIN WOULD
CONSIDER THIS TO BE AN ABOVE-AVERAGE CHALLENGE GIVEN FACTORS SUCH
AS MODEL DISAGREEMENT ON THE MAGNITUDE OF THE COLD AIR TODAY...AND
HOW MUCH OF A NON-DIURNAL TREND TONIGHT COULD HAVE OWING TO STEADY
SOUTHWEST BREEZES.
STARTING OFF EARLY THIS MORNING...THE VAST MAJORITY OF THE CWA IS
SITTING UNDER CLEAR/MOSTLY CLEAR SKIES IN THE WAKE OF A QUICK-
HITTING SYSTEM THAT BROUGHT A ROUND OF FLURRIES/BRIEF VERY LIGHT
SNOW TO MAINLY THE NORTHEAST 1/2 OF THE AREA EARLIER IN THE NIGHT.
THE ONLY REAL EXCEPTION TO THE CLEAR SKIES ARE FAIRLY RANDOM
PATCHES OF LOW STRATUS BASED AROUND 2000 FT THAT ARE DRIFTING
SOUTHWARD ACROSS THE AREA...ALTHOUGH 11-3.9 MICRON SATELLITE HAS
SUGGESTED THAT THIS STRATUS IS DIMINISHING IN AREAL COVERAGE. IN
THE BIG PICTURE ALOFT...WATER VAPOR SATELLITE AND SHORT TERM MODEL
DATA CONTINUE TO DEPICT...A BROAD LONGWAVE TROUGH ENCOMPASSING
MUCH OF THE CONUS...ALTHOUGH NOW A HIGH-AMPLITUDE RIDGE IS SET UP
JUST ALONG/OFF THE PACIFIC COAST...WHILE A NEARLY CUT OFF LOW
SPINS OFF NORTHERN BAJA. CLOSER TO HOME...THE LATEST IN A SERIES
OF NORTHWEST OF NORTHWEST-FLOW/CLIPPER SHORTWAVES IS STILL IN THE
PROCESS OF SHIFTING EASTWARD ACROSS EASTERN NEB/EASTERN
DAKOTAS/IA/MN...WHILE THE ENTIRE CENTRAL PLAINS GENERALLY RESIDES
IN THE ENTRANCE REGION OF A 130+KT UPPER JET STREAK EVIDENT AT
300MB AND CENTERED FROM EASTERN IA EASTWARD. AT THE SURFACE...09Z
OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A COLD/DRY 1036MB RIDGE AXIS
CENTERED OVER SOUTHEAST SD. SOUTH OF THE HIGH CENTER...AT-TIMES BREEZY
NORTHERLY WINDS QUICKLY OVERTOOK THE ENTIRE CWA THROUGH THE
NIGHT IN THE WAKE OF THE FAIRLY STRONG COLD FRONT...WITH SUSTAINED
SPEEDS CURRENTLY AVERAGING AT LEAST 10-15 MPH WITH SOME GUSTS TO
AROUND 20 OR HIGHER. FAIRLY PRONOUNCED COLD AIR ADVECTION IS
ESTABLISHED ACROSS THE REGION...WITH 10Z TEMPS LOCALLY RANGING
FROM 8 AT ORD...TO 16 AT HASTINGS...TO 23 AT BELOIT. AT THE
CURRENT RATE...ACTUAL MORNING LOWS BY 14Z/8AM ARE ON TRACK TO
RANGE FROM AROUND 2 IN THE FAR NORTHERN CWA...TO 14-16 IN THE FAR
SOUTH.
TURNING TO THE FORECAST AND STARTING WITH THE PRE-DAWN HOURS...THE
IMMEDIATE SHORT TERM ISSUE IS NAILING DOWN THE STEADY
TEMPERATURE/DEWPOINT DROPS. THANKS TO THE FALLING TEMPS AND STEADY
NORTH WINDS...WIND CHILLS BY SUNRISE ARE PROGGED TO BE WELL INTO
THE ZERO TO -10 RANGE ACROSS ROUGHLY THE NORTHEAST HALF OF THE
CWA...WITH THE FAR NORTHEAST POSSIBLE EVEN PUSHING -15.
OTHERWISE...ALTHOUGH NOT IN THE OFFICIAL FORECAST DUE TO ITS
EXTREMELY LIMITED COVERAGE...ANY OF THE REMAINING PATCHES OF LOW
STRATUS THIS MORNING COULD SQUEEZE OUT A ROGUE...BRIEF
FLURRY...SUCH AS RECENTLY REPORTED BY AWOS SITES SUCH AS
YORK/ALBION.
FOR THE DAYTIME HOURS...THE SYNOPTIC-SCALE ALOFT WILL FEATURE THE
CONTINUED DEPARTURE OF THE AFOREMENTIONED SHORTWAVE
TROUGH...ALLOWING THE WESTERN CONUS RIDGE TO START EASING EASTWARD
INTO THE CENTRAL PLAINS...RESULTING IN SUBTLE MID LEVEL HEIGHT
RISES. AT THE SURFACE...THE STOUT RIDGE CURRENTLY CENTERED OVER SD
WILL GRADUALLY SLIDE SOUTHEAST TO AN AXIS FROM SOUTHEAST KS-
SOUTHEAST IA BY SUNSET. AS THIS FEATURE PASSES ACROSS THE
CWA...THE MORNING WILL START OUT WITH NORTHERLY BREEZES AROUND 10
MPH IN THE EAST WHILE THE WEST STARTS TO GO LIGHT/VARIABLE. AS THE
DAY GOES ON...THE FAIRLY NARROW CORRIDOR OF LIGHT/VARIABLE BREEZES
WILL SLIDE EASTWARD ACROSS THE AREA...ALLOWING SOUTHWESTERLY FLOW
TO TAKE OVER IN ITS WAKE. BY LATE AFTERNOON...SUSTAINED 5-15 MPH
SOUTHWEST BREEZES WILL BE IN PLACE...LIGHTEST IN THE SOUTHEAST AND
STRONGEST NORTHWEST. AS FOR CLOUD COVER TODAY...EXPECT
SUNNY/MOSTLY SUNNY SKIES TO DOMINATE THE MAJORITY OF THE
AREA...AND THIS IS REFLECTED IN THE FORECAST GRIDS. HOWEVER...ONE
POTENTIAL CAVEAT TO WATCH FOR IS THE EVOLUTION OF LOW STRATUS OVER
WESTERN NEB...AS MODELS SUCH AS THE RAP13 SUGGEST THAT SOME OF
THIS STRATUS COULD GET CAUGHT IN THE SOUTHWEST LOW-LEVEL FLOW ON
THE BACKSIDE OF THE RIDGE AND TRY TO PUSH EASTWARD INTO AT LEAST
THE FAR WESTERN CWA THIS AFTERNOON. HOWEVER...ODDS ARE BETTER THAT
THE MAJORITY OF THIS POTENTIAL LOW CLOUD MASS WOULD FOCUS JUST
OUTSIDE THE CWA TO THE WEST/NORTHWEST. AT ANY RATE...RUNNING WITH
THE NO-WORSE-THAN MOSTLY SUNNY ASSUMPTION...THE BIG QUESTION
TODAY CENTERS AROUND THE BATTLE BETWEEN SUN AND DEVELOPING
SOUTHWESTERLY BREEZES...WHICH FAVORS WARMING...AND THE VERY COLD
LOW LEVEL AIRMASS THAT THE AREA IS STARTING THE DAY WITH ALONG
WITH LINGERING SNOW COVER...WHICH FAVORS COLDER. AFTER
PERUSING/BLENDING VARIOUS MODEL 2M TEMPS/GUIDANCE
SOLUTIONS...OPTED TO ONLY MAKE MINOR TWEAKS TO PREVIOUS
FORECAST...AIMING FOR A RANGE IN HIGHS FROM 16-20 ACROSS ROUGHLY
THE NORTHEAST 1/2...AND 22-26 ACROSS MUCH OF THE SOUTHWEST HALF.
ADMITTEDLY...THIS HAS THE POTENTIAL TO BE AN OPTIMISTIC
FORECAST...AS SOME DATA SETS SUCH AS THE 06Z NAM AND THE 00Z MAV
SUGGEST THAT GOING HIGHS ARE ROUGHLY 5 DEGREES TOO WARM. THE
FEELING AT THIS TIME IS THAT THESE SOLUTIONS ARE JUST A BIT TOO
PESSIMISTIC THOUGH...ESPECIALLY OVER THE RATHER SNOW-FREE
WESTERN/SOUTHERN ZONES.
TURNING TO THIS EVENING/TONIGHT...THE MAIN HIGHLIGHT WILL BE
MODEST BUT STEADY LOW-LEVEL WARM AIR ADVECTION...AS 850MB TEMPS
OVER THE CWA ARE PROGGED TO CLIMB FROM BETWEEN -3 TO -7C AT
00Z/6PM TO BETWEEN ZERO AND +4C BY 12Z/6AM. THE QUESTION THOUGH IS
HOW MUCH OF THIS WARMING WILL TRULY BE REALIZED AT THE SURFACE. ON
THE LARGE SCALE ALOFT TONIGHT...STEADY MID LEVEL HEIGHT RISES WILL
CONTINUE...AS THE BROAD WESTERN CONUS RIDGE EXERTS INCREASING
INFLUENCE...FURTHER DISPLACING THE LOCAL AREA FROM STRONGER UPPER
FLOW ASSOCIATED WITH SPLIT JET STREAMS...ONE ARCING ACROSS THE
U.S/CANADA BORDER INTO THE GREAT LAKES...AND THE SOUTHERN ONE
CENTERED FROM BAJA ACROSS TX INTO THE SOUTHEAST STATES. AT THE
SURFACE...BROAD SOUTHWESTERLY FLOW WILL PERSIST ACROSS THE CENTRAL
PLAINS TO THE NORTHWEST OF THE SOUTHEAST-MOVING RIDGE AXIS...WITH
SUSTAINED SPEEDS LOCALLY RANGING FROM 8-14 MPH WITH SOME HIGHER
GUSTS THROUGH MOST OF THE NIGHT...UNTIL A LULL TO MORE SO 5-8 MPH
OCCURS VERY LATE TOWARD SUNRISE THURSDAY. THIS SORT OF OVERNIGHT
PATTERN WITH STEADY SOUTHWEST BREEZES STRONGLY ARGUES FOR NEAR-
STEADY IF NOT SLOWLY RISING TEMPS IN SOME AREAS...BUT OTHER
FACTORS SUCH AS EXPECTED CLEAR/MOSTLY CLEAR SKIES...SNOW COVER AND
THE MODEST DECREASE IN WIND SPEEDS LATE IN THE NIGHT SUGGESTS THAT
THERE WILL LIKELY BE A COMPLEX BEHAVIOR OF HOURLY TEMPS
TONIGHT...SOMEWHAT AS WHAT OCCURRED MONDAY NIGHT/EARLY TUESDAY
MORNING. IN THE END...OPTED TO LEAN ACTUAL LOWS TOWARD THE MIDDLE
GROUND OF A RATHER WIDE-RANGE OF MODEL/GUIDANCE SOLUTIONS...BUT
THIS STILL ENDED UP RESULTING IN AN UPWARD NUDGE OF 3-4 DEGREES
FROM PREVIOUS FORECAST...CALLING FOR A FAIRLY UNIFORM RANGE ACROSS
THE CWA OF 9-12 DEGREES. THESE VALUES ARE A SOLID 3-5 DEGREES
ABOVE A 00Z MET/MAV GUIDANCE BLEND...WHICH JUST LOOKS TOO COLD
GIVEN THE WESTERLY FLOW/WARM AIR ADVECTION. BY THE SAME
TOKEN...THE OFFICIAL FORECAST IS NOT AS WARM AS RAW 2M TEMPS FROM
MODELS SUCH AS THE GFS/ECMWF...WHICH SUGGEST MUCH OF THE
WEST/SOUTH COULD HOLD ABOVE 15 THROUGH THE NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 458 AM CST WED DEC 11 2013
THE PRIMARY CHALLENGE WILL CONTINUE TO BE THE TEMPERATURE FORECAST
AND HOW TO HANDLE THE SNOW COVER IMPACTS ON TEMPERATURES. WE ARE IN
FOR A VERY NICE WARM-UP ON THURSDAY...LIKELY THE WARMEST DAY IN OVER
A WEEK. EXPECT A COLD FRONTAL PASSAGE ON FRIDAY THAT WILL RESULT IN
A RETURN OF SUB-FREEZING TEMPERATURES FOR MOST AREAS. SUNDAY SHOULD
BE A TRANSITION DAY WITH WARMER WESTERLY WINDS FOLLOWED BY EVEN
WARMER TEMPERATURES EARLY NEXT WEEK WHEN HIGHS SHOULD GENERALLY BE
ABOVE FREEZING. AT THIS TIME WE ARE NOT EXPECTING ANY ADDITIONAL
ACCUMULATING SNOWFALL EVENTS DURING THE LONG TERM PERIOD BUT CAN NOT
COMPLETELY RULE OUT FLURRIES.
THURSDAY...THE SFC WIND WILL TURN SOUTHWESTERLY AS THE SFC HIGH
SLIDES EAST AND AN UPPER RIDGE WILL BUILD ACROSS THE WESTERN CONUS
SENDING WARMER AIR ALOFT INTO THE HIGH PLAINS. 850 MB TEMPERATURES
WILL RISE BY AROUND 10 TO 15C FROM WEDNESDAY AFTERNOON TO THURSDAY
AFTERNOON. THEREFORE...EXPECT A QUICK WARM-UP WITH THE SNOW COVER
BEING THE ONLY THING LEFT LIMITING THE RISE. THERE CERTAINLY COULD
BE A 10 DEGREE OR GREATER DIFFERENCE IN HIGH TEMPERATURES BETWEEN
LOCATIONS WITH SNOW AND THOSE WITHOUT SNOW. FOR INSTANCE...WILL CALL
FOR A HIGH OF 42 IN ORD...AND UPPER 40S IN SOUTHERN TIER OF KS
COUNTIES WHERE THERE IS NO SNOW...BUT WILL ONLY CALL FOR A HIGH OF
32 IN HASTINGS DUE TO SNOW COVER.
FRIDAY...UNCERTAINTY IN TEMPERATURE FORECAST IS RATHER HIGH AS A
COLD FRONT WILL TRACK THROUGH DURING THE DAY AND THE MAGNITUDE OF
THE COLD AIR VARIES FROM MODEL TO MODEL. THE NAM RAW TEMPERATURES
ARE TOO COLD WITH THE NAM BELIEVING THERE IS A DEEPER AND MORE
WIDESPREAD SNOW PACK THAN WE REALLY HAVE. THE 00Z ECMWF MAY BE A
LITTLE TOO WARM AND HAVE LEANED TOWARD THE MIDDLE GROUND 00Z GFS. WE
SHOULD GENERALLY BE LOOKING AT UPPER 20S TO LOWER 30S ACROSS MOST OF
THE FORECAST AREA. DID NOT ACCOUNT FOR A SNOW COVER DIFFERENCE IN
THE TEMPERATURE FIELD DUE TO UNCERTAINTY WITH REGARD TO HOW MUCH
SNOW COVER WILL REMAIN AFTER THURSDAY. WITH REGARD TO
PRECIPITATION...IT SHOULD BE DRY...BUT IT MAY BE A CLOSE CALL FOR
SOUTHEASTERN ZONES AS A SHORTWAVE TRACKS ACROSS THE SOUTHERN PLAINS
AND SPREADS LIGHT SNOW AS FAR NORTH AS SOUTH CENTRAL KANSAS INTO
NORTHEAST KANSAS.
SATURDAY...FORECAST MODELS ARE FAIRLY CONSISTENT IN SHOWING A COOL
HIGH PRESSURE OVERHEAD WITH LIGHT NORTHERLY FLOW BEHIND A DEPARTING
UPPER LEVEL WAVE. NORTHEAST ZONES WILL CERTAINLY GET THE FULLER
BLAST OF THE COLD AND WILL STRUGGLE INTO THE MID 20S WHILE OUR
SOUTHWESTERN ZONES FROM BEAVER CITY TO STOCKTON MAY FLIRT WITH HIGHS
NEAR THE FREEZING MARK. SUBSIDENCE AND DRY WEATHER IS EXPECTED.
SUNDAY THROUGH TUESDAY...UNCERTAINTY REMAINS HIGH BUT HAS IMPROVED
SOME WITH MODELS TRENDING CLOSER TOGETHER AND MORE IN LINE WITH A
WARMER WEATHER REGIME. USED THE ALLBLEND MODEL SOLUTION FOR THESE
OUTER PERIODS...WHICH MAY BE A BIT TOO COOL IF CURRENT WARMER MODEL
TRENDS CONTINUE AND PREVAIL. THE OVERALL PATTERN THESE DAYS WILL BE
AN UPPER RIDGE OVER THE WESTERN CONUS AND THE JET STREAM GENERALLY
NORTH OF OUR FORECAST AREA. EXPECT TEMPERATURES WILL BE WARMER
SUNDAY THAN ON SATURDAY AND THEN EVEN WARMER STILL BY MONDAY AND
TUESDAY. ANY REMAINING SNOW WILL LIKELY MELT UNDER THIS SET UP.
THERE IS STILL HOPE FOR THOSE WANTING A WHITE CHRISTMAS AS BOTH THE
00Z GFS AND 00Z ECWMF SHOW A SHARP TURN TOWARDS COLD BY DEC 20TH OR
21ST WITH THE POTENTIAL OF A WINTER STORM SYSTEM SOMEWHERE IN THE
PLAINS JUST BEFORE CHRISTMAS BUT WAY TO EARLY TO PIN POINT ANYTHING.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1118 AM CST WED DEC 11 2013
LIGHT AND VARIABLE WINDS UNDER INFLUENCE OF SFC RIDGE AXIS WILL
TRANSITION SOUTHWESTERLY AS THE RIDGE SLIDES SOUTHEAST INTO
MISSOURI TODAY. PATCHY LOW CLOUDS RESIDE WEST AND SOUTH OF THE
TERMINAL AND EXPECT THE CLOUDS TO DIMINISH DURING THE DAY WITH NO
EFFECT FOR KGRI. HEADING INTO THIS EVENING AND THE FIRST PART OF
THE NIGHT HAVE MAINTAINED POTENTIAL FOR LOW LEVEL WIND SHEAR AS
LLVL WINDS RAPIDLY INCREASE WITH HEIGHT TO AROUND 40KTS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...FAY
AREA FORECAST DISCUSSION
NWS HASTINGS NE
649 AM CST WED DEC 11 2013
.UPDATE...
ISSUED AT 647 AM CST WED DEC 11 2013
ONLY MADE SOME VERY MINOR TWEAKS FOR THE LATEST UPDATE. AFTER
BRINGING THE LATEST TEMPS/DEWPOINTS IN LINE WITH CURRENT
OBS AND PERUSING LATEST SETS OF MODEL DATA...OPTED TO MAKE A
VERY MINOR...ACROSS-THE-BOARD 1 DEGREE DROP IN HIGHS TODAY VERSUS
EARLIER FORECAST. IN OTHER WORDS...A TAD BIT MORE OF MAINLY THE
NORTHEAST CWA IS NOW AIMED TO FALL SHORT OF 20. ALSO BUMPED UP SKY
COVER INTO PARTLY CLOUDY TERRITORY FOR A TIME THIS MORNING IN FAR
SOUTHERN ZONES TO ACCOUNT FOR EAST-WEST-BAND OF CIRRUS THAT IS
CENTERED JUST SOUTH OF THE CWA. OTHERWISE...SMALL SPLOTCHES OF
LOW STRATUS CONTINUE TO DRIFT ACROSS LIMITED PARTS OF BOTH THE
WESTERN/EASTERN CWA...AND AS EVIDENCED BY THE OB AT HEBRON A
LITTLE WHILE AGO...SOME ROGUE/BRIEF FLURRIES CANNOT BE RULED OUT
WHEREVER THESE CLOUDS HAPPEN TO BE. AS DETAILED IN THE EARLIER
DISCUSSION...DAY SHIFT WILL HAVE TO KEEP AN EYE ON STRATUS TRENDS
OVER WESTERN NEB...JUST IN CASE SOME OF THIS STARTS TO EXPAND BACK
EASTWARD INTO THE WESTERN/NORTHWEST CWA LATER TODAY AS HINTED BY
THE LATEST RAP13 900MB RELATIVE HUMIDITY FORECAST. THIS IS NO SURE
THING THOUGH...AS THE LATEST HRRR KEEPS SKIES CLEAR PER ITS LOW
LEVEL CLOUD COVER PRODUCT.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 458 AM CST WED DEC 11 2013
IN THE MIDST OF THE MODEST TEMPERATURE-ROLLER COASTER WE ARE NOW
RIDING...TODAY STILL LOOKS LIKE THE OVERALL-COLDEST DAY OUT OF THE
NEXT 7...AS WE CATCH THE WESTERN EDGES OF A GLANCING BLOW OF
ARCTIC AIR THAT IS PRIMARILY PASSING NORTHEAST OF THE AREA. GIVEN
THAT THERE IS ESSENTIALLY ZERO RISK OF PRECIP DURING THE NEXT 24
HOURS...TEMPS CONTINUE TO BE THE MAIN ISSUE...AND AGAIN WOULD
CONSIDER THIS TO BE AN ABOVE-AVERAGE CHALLENGE GIVEN FACTORS SUCH
AS MODEL DISAGREEMENT ON THE MAGNITUDE OF THE COLD AIR TODAY...AND
HOW MUCH OF A NON-DIURNAL TREND TONIGHT COULD HAVE OWING TO STEADY
SOUTHWEST BREEZES.
STARTING OFF EARLY THIS MORNING...THE VAST MAJORITY OF THE CWA IS
SITTING UNDER CLEAR/MOSTLY CLEAR SKIES IN THE WAKE OF A QUICK-
HITTING SYSTEM THAT BROUGHT A ROUND OF FLURRIES/BRIEF VERY LIGHT
SNOW TO MAINLY THE NORTHEAST 1/2 OF THE AREA EARLIER IN THE NIGHT.
THE ONLY REAL EXCEPTION TO THE CLEAR SKIES ARE FAIRLY RANDOM
PATCHES OF LOW STRATUS BASED AROUND 2000 FT THAT ARE DRIFTING
SOUTHWARD ACROSS THE AREA...ALTHOUGH 11-3.9 MICRON SATELLITE HAS
SUGGESTED THAT THIS STRATUS IS DIMINISHING IN AREAL COVERAGE. IN
THE BIG PICTURE ALOFT...WATER VAPOR SATELLITE AND SHORT TERM MODEL
DATA CONTINUE TO DEPICT...A BROAD LONGWAVE TROUGH ENCOMPASSING
MUCH OF THE CONUS...ALTHOUGH NOW A HIGH-AMPLITUDE RIDGE IS SET UP
JUST ALONG/OFF THE PACIFIC COAST...WHILE A NEARLY CUT OFF LOW
SPINS OFF NORTHERN BAJA. CLOSER TO HOME...THE LATEST IN A SERIES
OF NORTHWEST OF NORTHWEST-FLOW/CLIPPER SHORTWAVES IS STILL IN THE
PROCESS OF SHIFTING EASTWARD ACROSS EASTERN NEB/EASTERN
DAKOTAS/IA/MN...WHILE THE ENTIRE CENTRAL PLAINS GENERALLY RESIDES
IN THE ENTRANCE REGION OF A 130+KT UPPER JET STREAK EVIDENT AT
300MB AND CENTERED FROM EASTERN IA EASTWARD. AT THE SURFACE...09Z
OBJECTIVE SURFACE ANALYSIS HIGHLIGHTS A COLD/DRY 1036MB RIDGE AXIS
CENTERED OVER SOUTHEAST SD. SOUTH OF THE HIGH CENTER...AT-TIMES BREEZY
NORTHERLY WINDS QUICKLY OVERTOOK THE ENTIRE CWA THROUGH THE
NIGHT IN THE WAKE OF THE FAIRLY STRONG COLD FRONT...WITH SUSTAINED
SPEEDS CURRENTLY AVERAGING AT LEAST 10-15 MPH WITH SOME GUSTS TO
AROUND 20 OR HIGHER. FAIRLY PRONOUNCED COLD AIR ADVECTION IS
ESTABLISHED ACROSS THE REGION...WITH 10Z TEMPS LOCALLY RANGING
FROM 8 AT ORD...TO 16 AT HASTINGS...TO 23 AT BELOIT. AT THE
CURRENT RATE...ACTUAL MORNING LOWS BY 14Z/8AM ARE ON TRACK TO
RANGE FROM AROUND 2 IN THE FAR NORTHERN CWA...TO 14-16 IN THE FAR
SOUTH.
TURNING TO THE FORECAST AND STARTING WITH THE PRE-DAWN HOURS...THE
IMMEDIATE SHORT TERM ISSUE IS NAILING DOWN THE STEADY
TEMPERATURE/DEWPOINT DROPS. THANKS TO THE FALLING TEMPS AND STEADY
NORTH WINDS...WIND CHILLS BY SUNRISE ARE PROGGED TO BE WELL INTO
THE ZERO TO -10 RANGE ACROSS ROUGHLY THE NORTHEAST HALF OF THE
CWA...WITH THE FAR NORTHEAST POSSIBLE EVEN PUSHING -15.
OTHERWISE...ALTHOUGH NOT IN THE OFFICIAL FORECAST DUE TO ITS
EXTREMELY LIMITED COVERAGE...ANY OF THE REMAINING PATCHES OF LOW
STRATUS THIS MORNING COULD SQUEEZE OUT A ROGUE...BRIEF
FLURRY...SUCH AS RECENTLY REPORTED BY AWOS SITES SUCH AS
YORK/ALBION.
FOR THE DAYTIME HOURS...THE SYNOPTIC-SCALE ALOFT WILL FEATURE THE
CONTINUED DEPARTURE OF THE AFOREMENTIONED SHORTWAVE
TROUGH...ALLOWING THE WESTERN CONUS RIDGE TO START EASING EASTWARD
INTO THE CENTRAL PLAINS...RESULTING IN SUBTLE MID LEVEL HEIGHT
RISES. AT THE SURFACE...THE STOUT RIDGE CURRENTLY CENTERED OVER SD
WILL GRADUALLY SLIDE SOUTHEAST TO AN AXIS FROM SOUTHEAST KS-
SOUTHEAST IA BY SUNSET. AS THIS FEATURE PASSES ACROSS THE
CWA...THE MORNING WILL START OUT WITH NORTHERLY BREEZES AROUND 10
MPH IN THE EAST WHILE THE WEST STARTS TO GO LIGHT/VARIABLE. AS THE
DAY GOES ON...THE FAIRLY NARROW CORRIDOR OF LIGHT/VARIABLE BREEZES
WILL SLIDE EASTWARD ACROSS THE AREA...ALLOWING SOUTHWESTERLY FLOW
TO TAKE OVER IN ITS WAKE. BY LATE AFTERNOON...SUSTAINED 5-15 MPH
SOUTHWEST BREEZES WILL BE IN PLACE...LIGHTEST IN THE SOUTHEAST AND
STRONGEST NORTHWEST. AS FOR CLOUD COVER TODAY...EXPECT
SUNNY/MOSTLY SUNNY SKIES TO DOMINATE THE MAJORITY OF THE
AREA...AND THIS IS REFLECTED IN THE FORECAST GRIDS. HOWEVER...ONE
POTENTIAL CAVEAT TO WATCH FOR IS THE EVOLUTION OF LOW STRATUS OVER
WESTERN NEB...AS MODELS SUCH AS THE RAP13 SUGGEST THAT SOME OF
THIS STRATUS COULD GET CAUGHT IN THE SOUTHWEST LOW-LEVEL FLOW ON
THE BACKSIDE OF THE RIDGE AND TRY TO PUSH EASTWARD INTO AT LEAST
THE FAR WESTERN CWA THIS AFTERNOON. HOWEVER...ODDS ARE BETTER THAT
THE MAJORITY OF THIS POTENTIAL LOW CLOUD MASS WOULD FOCUS JUST
OUTSIDE THE CWA TO THE WEST/NORTHWEST. AT ANY RATE...RUNNING WITH
THE NO-WORSE-THAN MOSTLY SUNNY ASSUMPTION...THE BIG QUESTION
TODAY CENTERS AROUND THE BATTLE BETWEEN SUN AND DEVELOPING
SOUTHWESTERLY BREEZES...WHICH FAVORS WARMING...AND THE VERY COLD
LOW LEVEL AIRMASS THAT THE AREA IS STARTING THE DAY WITH ALONG
WITH LINGERING SNOW COVER...WHICH FAVORS COLDER. AFTER
PERUSING/BLENDING VARIOUS MODEL 2M TEMPS/GUIDANCE
SOLUTIONS...OPTED TO ONLY MAKE MINOR TWEAKS TO PREVIOUS
FORECAST...AIMING FOR A RANGE IN HIGHS FROM 16-20 ACROSS ROUGHLY
THE NORTHEAST 1/2...AND 22-26 ACROSS MUCH OF THE SOUTHWEST HALF.
ADMITTEDLY...THIS HAS THE POTENTIAL TO BE AN OPTIMISTIC
FORECAST...AS SOME DATA SETS SUCH AS THE 06Z NAM AND THE 00Z MAV
SUGGEST THAT GOING HIGHS ARE ROUGHLY 5 DEGREES TOO WARM. THE
FEELING AT THIS TIME IS THAT THESE SOLUTIONS ARE JUST A BIT TOO
PESSIMISTIC THOUGH...ESPECIALLY OVER THE RATHER SNOW-FREE
WESTERN/SOUTHERN ZONES.
TURNING TO THIS EVENING/TONIGHT...THE MAIN HIGHLIGHT WILL BE
MODEST BUT STEADY LOW-LEVEL WARM AIR ADVECTION...AS 850MB TEMPS
OVER THE CWA ARE PROGGED TO CLIMB FROM BETWEEN -3 TO -7C AT
00Z/6PM TO BETWEEN ZERO AND +4C BY 12Z/6AM. THE QUESTION THOUGH IS
HOW MUCH OF THIS WARMING WILL TRULY BE REALIZED AT THE SURFACE. ON
THE LARGE SCALE ALOFT TONIGHT...STEADY MID LEVEL HEIGHT RISES WILL
CONTINUE...AS THE BROAD WESTERN CONUS RIDGE EXERTS INCREASING
INFLUENCE...FURTHER DISPLACING THE LOCAL AREA FROM STRONGER UPPER
FLOW ASSOCIATED WITH SPLIT JET STREAMS...ONE ARCING ACROSS THE
U.S/CANADA BORDER INTO THE GREAT LAKES...AND THE SOUTHERN ONE
CENTERED FROM BAJA ACROSS TX INTO THE SOUTHEAST STATES. AT THE
SURFACE...BROAD SOUTHWESTERLY FLOW WILL PERSIST ACROSS THE CENTRAL
PLAINS TO THE NORTHWEST OF THE SOUTHEAST-MOVING RIDGE AXIS...WITH
SUSTAINED SPEEDS LOCALLY RANGING FROM 8-14 MPH WITH SOME HIGHER
GUSTS THROUGH MOST OF THE NIGHT...UNTIL A LULL TO MORE SO 5-8 MPH
OCCURS VERY LATE TOWARD SUNRISE THURSDAY. THIS SORT OF OVERNIGHT
PATTERN WITH STEADY SOUTHWEST BREEZES STRONGLY ARGUES FOR NEAR-
STEADY IF NOT SLOWLY RISING TEMPS IN SOME AREAS...BUT OTHER
FACTORS SUCH AS EXPECTED CLEAR/MOSTLY CLEAR SKIES...SNOW COVER AND
THE MODEST DECREASE IN WIND SPEEDS LATE IN THE NIGHT SUGGESTS THAT
THERE WILL LIKELY BE A COMPLEX BEHAVIOR OF HOURLY TEMPS
TONIGHT...SOMEWHAT AS WHAT OCCURRED MONDAY NIGHT/EARLY TUESDAY
MORNING. IN THE END...OPTED TO LEAN ACTUAL LOWS TOWARD THE MIDDLE
GROUND OF A RATHER WIDE-RANGE OF MODEL/GUIDANCE SOLUTIONS...BUT
THIS STILL ENDED UP RESULTING IN AN UPWARD NUDGE OF 3-4 DEGREES
FROM PREVIOUS FORECAST...CALLING FOR A FAIRLY UNIFORM RANGE ACROSS
THE CWA OF 9-12 DEGREES. THESE VALUES ARE A SOLID 3-5 DEGREES
ABOVE A 00Z MET/MAV GUIDANCE BLEND...WHICH JUST LOOKS TOO COLD
GIVEN THE WESTERLY FLOW/WARM AIR ADVECTION. BY THE SAME
TOKEN...THE OFFICIAL FORECAST IS NOT AS WARM AS RAW 2M TEMPS FROM
MODELS SUCH AS THE GFS/ECMWF...WHICH SUGGEST MUCH OF THE
WEST/SOUTH COULD HOLD ABOVE 15 THROUGH THE NIGHT.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 458 AM CST WED DEC 11 2013
THE PRIMARY CHALLENGE WILL CONTINUE TO BE THE TEMPERATURE FORECAST
AND HOW TO HANDLE THE SNOW COVER IMPACTS ON TEMPERATURES. WE ARE IN
FOR A VERY NICE WARM-UP ON THURSDAY...LIKELY THE WARMEST DAY IN OVER
A WEEK. EXPECT A COLD FRONTAL PASSAGE ON FRIDAY THAT WILL RESULT IN
A RETURN OF SUB-FREEZING TEMPERATURES FOR MOST AREAS. SUNDAY SHOULD
BE A TRANSITION DAY WITH WARMER WESTERLY WINDS FOLLOWED BY EVEN
WARMER TEMPERATURES EARLY NEXT WEEK WHEN HIGHS SHOULD GENERALLY BE
ABOVE FREEZING. AT THIS TIME WE ARE NOT EXPECTING ANY ADDITIONAL
ACCUMULATING SNOWFALL EVENTS DURING THE LONG TERM PERIOD BUT CAN NOT
COMPLETELY RULE OUT FLURRIES.
THURSDAY...THE SFC WIND WILL TURN SOUTHWESTERLY AS THE SFC HIGH
SLIDES EAST AND AN UPPER RIDGE WILL BUILD ACROSS THE WESTERN CONUS
SENDING WARMER AIR ALOFT INTO THE HIGH PLAINS. 850 MB TEMPERATURES
WILL RISE BY AROUND 10 TO 15C FROM WEDNESDAY AFTERNOON TO THURSDAY
AFTERNOON. THEREFORE...EXPECT A QUICK WARM-UP WITH THE SNOW COVER
BEING THE ONLY THING LEFT LIMITING THE RISE. THERE CERTAINLY COULD
BE A 10 DEGREE OR GREATER DIFFERENCE IN HIGH TEMPERATURES BETWEEN
LOCATIONS WITH SNOW AND THOSE WITHOUT SNOW. FOR INSTANCE...WILL CALL
FOR A HIGH OF 42 IN ORD...AND UPPER 40S IN SOUTHERN TIER OF KS
COUNTIES WHERE THERE IS NO SNOW...BUT WILL ONLY CALL FOR A HIGH OF
32 IN HASTINGS DUE TO SNOW COVER.
FRIDAY...UNCERTAINTY IN TEMPERATURE FORECAST IS RATHER HIGH AS A
COLD FRONT WILL TRACK THROUGH DURING THE DAY AND THE MAGNITUDE OF
THE COLD AIR VARIES FROM MODEL TO MODEL. THE NAM RAW TEMPERATURES
ARE TOO COLD WITH THE NAM BELIEVING THERE IS A DEEPER AND MORE
WIDESPREAD SNOW PACK THAN WE REALLY HAVE. THE 00Z ECMWF MAY BE A
LITTLE TOO WARM AND HAVE LEANED TOWARD THE MIDDLE GROUND 00Z GFS. WE
SHOULD GENERALLY BE LOOKING AT UPPER 20S TO LOWER 30S ACROSS MOST OF
THE FORECAST AREA. DID NOT ACCOUNT FOR A SNOW COVER DIFFERENCE IN
THE TEMPERATURE FIELD DUE TO UNCERTAINTY WITH REGARD TO HOW MUCH
SNOW COVER WILL REMAIN AFTER THURSDAY. WITH REGARD TO
PRECIPITATION...IT SHOULD BE DRY...BUT IT MAY BE A CLOSE CALL FOR
SOUTHEASTERN ZONES AS A SHORTWAVE TRACKS ACROSS THE SOUTHERN PLAINS
AND SPREADS LIGHT SNOW AS FAR NORTH AS SOUTH CENTRAL KANSAS INTO
NORTHEAST KANSAS.
SATURDAY...FORECAST MODELS ARE FAIRLY CONSISTENT IN SHOWING A COOL
HIGH PRESSURE OVERHEAD WITH LIGHT NORTHERLY FLOW BEHIND A DEPARTING
UPPER LEVEL WAVE. NORTHEAST ZONES WILL CERTAINLY GET THE FULLER
BLAST OF THE COLD AND WILL STRUGGLE INTO THE MID 20S WHILE OUR
SOUTHWESTERN ZONES FROM BEAVER CITY TO STOCKTON MAY FLIRT WITH HIGHS
NEAR THE FREEZING MARK. SUBSIDENCE AND DRY WEATHER IS EXPECTED.
SUNDAY THROUGH TUESDAY...UNCERTAINTY REMAINS HIGH BUT HAS IMPROVED
SOME WITH MODELS TRENDING CLOSER TOGETHER AND MORE IN LINE WITH A
WARMER WEATHER REGIME. USED THE ALLBLEND MODEL SOLUTION FOR THESE
OUTER PERIODS...WHICH MAY BE A BIT TOO COOL IF CURRENT WARMER MODEL
TRENDS CONTINUE AND PREVAIL. THE OVERALL PATTERN THESE DAYS WILL BE
AN UPPER RIDGE OVER THE WESTERN CONUS AND THE JET STREAM GENERALLY
NORTH OF OUR FORECAST AREA. EXPECT TEMPERATURES WILL BE WARMER
SUNDAY THAN ON SATURDAY AND THEN EVEN WARMER STILL BY MONDAY AND
TUESDAY. ANY REMAINING SNOW WILL LIKELY MELT UNDER THIS SET UP.
THERE IS STILL HOPE FOR THOSE WANTING A WHITE CHRISTMAS AS BOTH THE
00Z GFS AND 00Z ECWMF SHOW A SHARP TURN TOWARDS COLD BY DEC 20TH OR
21ST WITH THE POTENTIAL OF A WINTER STORM SYSTEM SOMEWHERE IN THE
PLAINS JUST BEFORE CHRISTMAS BUT WAY TO EARLY TO PIN POINT ANYTHING.
&&
.AVIATION...(FOR THE 12Z KGRI TAF THROUGH 12Z THURSDAY MORNING)
ISSUED AT 550 AM CST WED DEC 11 2013
CONFIDENCE REMAINS HIGH IN VFR CEILING/VISIBILITY THROUGH THE
VAST MAJORITY OF THE PERIOD...WITH THE ONLY FORESEEN EXCEPTION
CONSISTING OF A SMALL AREA OF BKN/OVC STRATUS THAT IS LURKING
VERY NEAR/OVER THE TERMINAL RIGHT AWAY THIS MORNING. GIVEN THAT
ANY LOW CEILING IS ONLY EXPECTED TO LAST A SHORT TIME...WILL ONLY
CARRY A 2-HOUR TEMPO GROUP FOR IT. ONCE THIS STRATUS VACATES...THE
REMAINDER OF THE PERIOD SHOULD BE LARGELY CLOUD-FREE. DURING THE
LATTER HALF OF THE PERIOD...MAINLY BETWEEN 02Z-07Z...CONFIDENCE
HAS INCREASED ENOUGH IN A PERIOD OF LOW LEVEL WIND SHEAR TO
INTRODUCE INTO THE TAF...AS SURFACE WINDS AVERAGE AROUND 13KT FROM
THE SOUTHWEST WHILE WINDS WITHIN THE LOWEST 1200 FT AGL ACCELERATE
TO OVER 40KT FROM THE WEST...CREATING 30-35KT OF WIND VECTOR
DIFFERENCE BETWEEN THESE LEVELS. BACKING UP TO THE DAYTIME
HOURS...SURFACE BREEZES WILL START OUT NORTHERLY BEFORE BECOMING
FAIRLY LIGHT/VARIABLE AROUND MID-DAY...AND THEN BECOMING
ESTABLISHED FROM THE SOUTHWEST DURING THE AFTERNOON.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
UPDATE...PFANNKUCH
SHORT TERM...PFANNKUCH
LONG TERM...WESELY
AVIATION...PFANNKUCH
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1130 PM CST TUE DEC 10 2013
.SYNOPSIS...
ISSUED AT 305 PM CST TUE DEC 10 2013
H5 ANALYSIS THIS MORNING HAS BROAD NORTHWESTERLY FLOW
ACROSS THE WESTERN HALF OF THE CONUS WITH DEEP LOW PRESSURE OVER SRN
HUDSON BAY. AT THE SURFACE...A COLD FRONT EXTENDED FROM NERN WYOMING
INTO NERN SD. FURTHER SOUTH ACROSS WESTERN AND NORTH CENTRAL
NEBRASKA...WESTERLY FLOW HAS DEVELOPED THIS AFTERNOON WITH
TEMPERATURES REACHING THE 20S AND LOWER 30S.
&&
.UPDATE...
ISSUED AT 614 PM CST TUE DEC 10 2013
THE ECM...RAP...GEM REG AND HRRR MODELS SHOW WIND CHILL ADVISORY
CONDITIONS BY MORNING ACROSS THE NORTHEAST FROM AINWSORTH AND
ONEILL NORTH. A NEW FORECAST IS OUT FOR THESE CONDITIONS.
OTHERWISE THE REST OF THE FORECAST IS ON TRACK WITH THE LEADING
EDGE OF THE ARCTIC AIR ENTERING SHERIDAN COUNTY AND SETTING OFF
SNOW SHOWERS. LOW LEVEL LAPSE RATES ARE VERY STEEP WITH ECHO TOPS
LESS THAN 10KFT.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 305 PM CST TUE DEC 10 2013
AN ARCTIC COLD FRONT WILL MOVE SOUTHEAST ACROSS THE AREA
TONIGHT...WITH A FEW SNOW SHOWERS POSSIBLE ACROSS NORTHERN NEBRASKA
BEHIND THE FRONT. FLURRIES ARE POSSIBLE FARTHER SOUTH AS
WELL...WITH A PERIOD OF WEAK LIFT THROUGH A SATURATED DENDRITIC
LAYER BEHIND THE FRONT. OTHERWISE...WINDS DIMINISH AS HIGH PRESSURE
SETTLES INTO NORTHERN NEBRASKA LATE TONIGHT. THIS WILL ALLOW FOR
LOWS TO DROP TO NEAR ZERO OR JUST BELOW AS SKIES CLEAR LATE.
FARTHER SOUTH WINDS REMAIN UP THROUGH THE NIGHT...AND THIS WILL
HELP KEEP LOWS SOMEWHAT WARMER.
HIGH PRESSURE WILL QUICKLY MOVE SOUTHEAST OF THE AREA
WEDNESDAY...WITH WARMING SOUTHWEST WINDS DEVELOPING BY WEDNESDAY
AFTERNOON. HAVE PUSHED HIGHS UP INTO THE LOWER 30S ACROSS
SOUTHWEST NEBRASKA...BUT ONLY NEAR 20 DEGREES ACROSS EASTERN
PORTIONS OF NORTH CENTRAL NEBRASKA WHERE THE ARCTIC AIR WILL BE
DEEPER.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 305 PM CST TUE DEC 10 2013
IN THE MID
RANGE...TEMPERATURES ARE THE MAIN FORECAST CHALLENGE. FOR WEDNESDAY
NIGHT...LOOK FOR WINDS TO DECREASE BY LATE EVENING AS A WARM FRONT
TRACKS EAST OF THE AREA. CLEAR SKIES AND LIGHT WINDS WILL ALLOW
TEMPS TO DIP INTO THE SINGLE DIGITS ACROSS THE FORECAST AREA.
INHERITED FORECAST HAD ALOT OF TEENS FOR LOWS WEDS NIGHT AND SCALED
THESE BACK TOWARD THE NEW GUIDANCE...WHICH TRENDED MUCH LOWER AS
WELL. ON THURSDAY...WARMER PACIFIC AIR WILL PUSH INTO THE CENTRAL
PLAINS WITH H85 TEMPS REACHING THE MIDDLE SINGLE DIGITS CELSIUS
ABOVE ZERO THURSDAY AFTERNOON. NORMALLY WITH GOOD MIXING...HIGHS
WOULD REACH THE UPPER 40S TO LOWER 50S. HOWEVER...WINDS ARE EXPECTED
TO BE FAIRLY LIGHT THURSDAY...A BY PRODUCT OF SNOW COVER AND ITS
IMPACT ON MIXING. BUFKIT SOUNDINGS FOR BOTH LBF AND VTN ARE NOT
INDICATIVE OF MIXING EITHER. GUIDANCE HIGHS THURSDAY FOR VALENTINE
WERE IN THE MID 40S WITH THIS MORNINGS FCST. THIS SEEMS WAY TOO HIGH
WITH 6+ INCHES OF SNOW EXPECTED TO BE ON THE GROUND ACROSS NORTH
CENTRAL NEBRASKA. HAVE OPTED FOR HIGH IN THE LOWER 40S SOUTHWEST TO
LOWER 30S IN THE NORTHEAST AND PORTIONS OF THE NORTH CENTRAL
FORECAST AREA. LOWS THURSDAY NIGHT WILL BE SLIGHTLY HIGHER THAN
WEDNESDAY NIGHTS MIN TEMPS DUE TO INCREASED HIGH LEVEL
CLOUDINESS...AND THE DEVELOPMENT OF LIGHT WINDS IN ADVANCE OF THE
NEXT ARCTIC COLD FRONT WHICH WILL ARRIVE SOMETIME FRIDAY MORNING OR
AFTERNOON. I DID GO AHEAD AND TREND DOWN HIGHS FRIDAY ACROSS THE
NORTHERN CWA BASED ON A SLIGHTLY FASTER FRONTAL TIMING IE. GFS
SOLUTION...WHICH HAS BEEN MORE CONSISTENT. HIGHS FRIDAY WILL RANGE
FROM THE MID 20S IN THE NORTHEAST...TO AROUND 40 IN THE
SOUTHWEST.
FRIDAY NIGHT THROUGH TUESDAY...BROAD NORTHWESTERLY FLOW WILL
CONTINUE ACROSS THE CENTRAL AND NORTHERN PLAINS FOR THE EXTENDED
PERIOD. WITH THE NORTHWESTERLY FLOW IN PLACE ARCTIC COLD AIR WILL
BACK INTO THE FORECAST AREA SATURDAY...RETREATING EASTWARD LATE
SUNDAY OR MONDAY. ATTM...THE GFS AND ECMWF SOLUTIONS ARE AT ODDS
WITH HOW FAST THE FRONT PUSHES EAST OUT OF THE AREA WITH THE GFS
BEING SLOWER. ON MONDAY INTO TUESDAY...THE GFS ADVERTISES A NICE
WARMUP WHILE THE ECMWF USHERS IN ANOTHER SHOT OF ARCTIC AIR. FOR
NOW...WILL COMPROMISE BETWEEN SOLUTIONS AND LEAVE THE FORECAST DRY
AS THE NORTHWESTERLY FLOW FAVORS IT.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1129 PM CST TUE DEC 10 2013
MVFR CIGS BETWEEN KVTN AND KTIF WILL DROP SOUTH THROUGH KLBF
OVERNIGHT. THE MODELS THEN SUGGEST THIS MOISTURE WILL BECOME
TRAPPED AND PRODUCE IFR/LIFR CIGS TOWARD MORNING BUT THIS IS
UNCERTAIN GIVEN THE VERTICAL MIXING THAT COULD DEVELOP AFTER
SUNRISE.
THE FCST FOLLOWS THE MODEL SOLN AT KLBF BUT KEEPS KVTN IN VFR
DURING THE MORNING. IF THE MVFR/IFR CIGS DEVELOP AT KLBF AFTER
NEAR OR AFTER SUNRISE THEN THEY WOULD LIKELY GET LIFTED EAST
THROUGH KANW/KONL/KBBW DURING THE LATE MORNING AND AFTN AS A
DEVELOPING WARM FRONT.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 11 AM CST WEDNESDAY FOR NEZ006>010.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...TAYLOR
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
929 PM CST THU DEC 12 2013
.UPDATE...
ISSUED AT 929 PM CST THU DEC 12 2013
SNOW BAND HAS STARTED TO DEVELOP...BUT HAS BEEN A BIT FURTHER
SOUTH THAN ORIGINALLY EXPECTED AND SOME FLAKES HAVE ALREADY BEEN
REPORTED AT COOPERSTOWN AND VALLEY CITY ALTHOUGH NOT CONSISTENTLY.
BROUGHT POPS A BIT FURTHER SOUTH FOR TONIGHT AND MADE SOME FURTHER
ADJUSTMENTS TO QPF AS NOT MUCH WILL ACCUMULATE BEFORE MIDNIGHT.
TEMPS STILL SEEM ON TRACK TO DROP DOWN SIGNIFICANTLY LATER
TONIGHT...AND WINDS WILL STAY NORTH TO NORTHEASTERLY AT AROUND 10
TO 15 MPH. WILL CONTINUE TO KEEP THE WIND CHILL HEADLINE THAT WE
HAVE GOING.
UPDATE ISSUED AT 635 PM CST THU DEC 12 2013
THERE HAS BEEN A BREAK IN THE SNOW EARLY THIS EVENING...BUT
SHORT RANGE MODELS HAVE THE SNOW BAND REDEVELOPING IN THE DEVILS
LAKE BASIN SOON...SO KEPT POPS THAT RAMP UP IN THE NEXT FEW HOURS
GOING. DID CUT AMOUNTS TOWARDS THE SOUTH AND EAST THOUGH. TEMPS
CONTINUE TO BE ON TRACK SO WILL KEEP LOWS IN THE TEENS BELOW ZERO
UP NORTH TO NEAR ZERO IN THE SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM CST THU DEC 12 2013
MAIN FORECAST CONCERNS IN THE SHORT TERM WILL BE EXTENT OF LIGHT
SNOW WITH PASSING UPPER WAVES AND TEMP TRENDS...WITH COLD AIR
REMAINING FIRMLY ENTRENCHED.
A NARROW BAND OF LIGHT SNOW HAS PROGRESSED FROM THE NORTHERN
VALLEY SOUTHEASTWARD INTO NW MINNESOTA THIS AFTERNOON. THIS WILL
CONTINUE TO SHIFT SOUTHEASTWARD THROUGH THE REST OF THE AFTERNOON.
ANOTHER AREA OF LIGHT SNOW WILL SHIFT INTO THE DEVILS LAKE BASIN
THIS EVENING AND SOUTHEASTWARD OVERNIGHT...IN ASSOCIATION WITH AN
AREA OF MID-LEVEL FRONTOGENESIS AND SYNOPTIC FORCING IN THE RIGHT
ENTRANCE REGION OF A BROAD UPPER JET. AS THE FORCING GRADUALLY
WEAKENS...A DECREASING TREND IN THE SNOWFALL IS EXPECTED WITH TIME
AS THE SNOW SHIFTS SOUTHWARD. RIGHT NOW THE BEST CHANCE FOR 1 TO 3
INCHES OF ACCUMULATION LOOKS TO BE FROM THE DEVILS LAKE AREA INTO
PARTS OF THE NORTHERN AND CENTRAL VALLEY TONIGHT INTO FRIDAY.
TEMPS TONIGHT MAY BE TRICKY. ALTHOUGH LOW-LEVEL COLD ADVECTION
WILL CONTINUE THROUGH THE NIGHT...HOW MUCH TEMPS FALL WILL DEPEND
ON CLOUD COVERAGE. THE RAP BRINGS SOME LOW-LEVEL DRYING INTO PARTS
OF NORTHWEST MINNESOTA OVERNIGHT. TEMPS COULD DROP PRETTY QUICKLY
IF ANY CLEARING DOES OCCUR...AND THUS HAVE THE LOWEST TEMPS IN
THIS AREA OF NW MINNESOTA. HIGHS ON FRIDAY LIKELY WILL BE COLDEST
NORTH...WITH TEMPS REMAINING BELOW ZERO...AND SINGLE DIGITS ABOVE
ZERO FARTHER SOUTH.
AS WINDS ARE EXPECTED TO STAY UP AROUND 10 KTS OVERNIGHT...WILL
ALSO ISSUE A WIND CHILL ADVISORY FOR MUCH OF NE ND EASTWARD INTO
NW MN FROM 06Z TONIGHT THROUGH 03Z SATURDAY. WITH WINDS BRISK FROM
THE NORTHEAST ON FRIDAY AHEAD OF THE SFC HIGH...HELD ONTO THE
ADVISORY UNTIL FRIDAY EVENING...ALTHOUGH WIND CHILLS MAY RISE ABOVE
CRITERIA FOR A BIT DURING THE DAY. AS THE SFC RIDGE AXIS
APPROACHES FRIDAY NIGHT...WINDS MAY GO LIGHT...ALLOWING FOR WIND
CHILLS TO RISE ABOVE ADVISORY THRESHOLD. THIS WILL BE MONITORED
DURING FUTURE SHIFTS THOUGH.
A SERIES OF UPPER IMPULSES EMBEDDED IN NORTHWEST FLOW ALOFT WILL
CONTINUE TO AFFECT THE AREA FRIDAY NIGHT INTO SATURDAY...BRINGING
CONTINUED CHANCES FOR LIGHT SNOW. ALTHOUGH MODEL QPF IS LOW...WITH
HIGH SNOW RATIOS AND MODEL SOUNDINGS INDICATING A FAIRLY DEEP
SATURATED LAYER...A FLUFFY INCH OR TWO OF SNOW IS
POSSIBLE...DEPENDING ON THE EXACT TRACK OF THE IMPULSES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 PM CST THU DEC 12 2013
TEMPS ON SATURDAY WILL RISE INTO THE SINGLE DIGITS EITHER SIDE OF
ZERO WITH LIGHT SNOW REMAINING POSSIBLE AS UPPER LEVEL ENERGY
CASCADES THROUGH THE FLOW. A SFC RIDGE WILL SPREAD OVER THE AREA
ON SATURDAY NIGHT. THE MAIN QUESTION WILL BE TEMPS...WHICH WILL BE
DEPENDENT ON CLOUD COVER. THUS...TEMPS COULD BE A BIT COLDER IF
SKIES DO CLEAR.
ANOTHER ROUND OF LIGHT SNOW IS POSSIBLE SUNDAY AS WARM AIR ADVECTION
DEVELOPS AND THE LOW-LEVEL BAROCLINIC ZONE APPROACHES FROM THE WEST
AHEAD OF THE NEXT UPPER WAVE. HOWEVER...TEMPS WILL REMAIN WELL
BELOW NORMAL.
FOR THE SUNDAY NIGHT THROUGH THURSDAY PERIOD...12Z ECMWF/GFS/GEM SO
ENOUGH DISAGREEMENT IN TIMING AND LOCATION OF SEVERAL 500 MB SHORT
WAVES/SURFACE LOW PRESSURE SYSTEMS TO KEEP CONFIDENCE IN FCST A BIT
LOWER THAN NORMAL. IDEA IS FOR ONE SHORT WAVE MONDAY TO EXIT
FOLLOWED BY SOME COLDER AIR MON NIGHT-TUE THEN THE NEXT ONE DUE WED
NIGHT-THU TIME FRAME. EXACT PLACEMENT OF LOWS WILL MEAN POTENTIAL
TEMP DIFFERENCES WITH OVERALL 12Z EURO AND GEM A BIT WARMER THAN 12Z
GFS ESP FOR MID WEEK SYSTEM. WITH THE DIFFERENCES STUCK WITH ALL
BLEND GUIDANCE. THERAFTER AND BEYOND THIS PERIOD IS WHEN THE NEXT
ARCTIC OUBREAK WILL OCCUR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 635 PM CST THU DEC 12 2013
CIGS HAVE BEEN BORDERLINE BETWEEN VFR AND MVFR. THE LEVELS OF THE
CEILINGS WILL SLOWLY DECREASE THROUGHOUT THE PERIOD...ALTHOUGH
THINK THAT THEY WILL STAY MVFR. SOME REDUCTIONS IN VIS AS A SNOW
BAND BUILDS FROM NEAR KDVL TO THE SOUTH AND EAST LATER TONIGHT AND
INTO TOMORROW. THINK THAT AMOUNTS WILL BE FAIRLY LIGHT AND VIS
WILL STAY IN THE 2-5SM RANGE. NORTHWEST WINDS WILL STAY AT AROUND
10 TO 15 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL 9 PM CST FRIDAY FOR NDZ006>008-014>016-
024-026>030-054.
MN...WIND CHILL ADVISORY UNTIL 9 PM CST FRIDAY FOR MNZ001-002-004>009-
013>017-022-023.
&&
$$
UPDATE...JR
SHORT TERM...MAKOWSKI
LONG TERM...RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
636 PM CST THU DEC 12 2013
.UPDATE...
ISSUED AT 635 PM CST THU DEC 12 2013
THERE HAS BEEN A BREAK IN THE SNOW EARLY THIS EVENING...BUT
SHORT RANGE MODELS HAVE THE SNOW BAND REDEVELOPING IN THE DEVILS
LAKE BASIN SOON...SO KEPT POPS THAT RAMP UP IN THE NEXT FEW HOURS
GOING. DID CUT AMOUNTS TOWARDS THE SOUTH AND EAST THOUGH. TEMPS
CONTINUE TO BE ON TRACK SO WILL KEEP LOWS IN THE TEENS BELOW ZERO
UP NORTH TO NEAR ZERO IN THE SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM CST THU DEC 12 2013
MAIN FORECAST CONCERNS IN THE SHORT TERM WILL BE EXTENT OF LIGHT
SNOW WITH PASSING UPPER WAVES AND TEMP TRENDS...WITH COLD AIR
REMAINING FIRMLY ENTRENCHED.
A NARROW BAND OF LIGHT SNOW HAS PROGRESSED FROM THE NORTHERN
VALLEY SOUTHEASTWARD INTO NW MINNESOTA THIS AFTERNOON. THIS WILL
CONTINUE TO SHIFT SOUTHEASTWARD THROUGH THE REST OF THE AFTERNOON.
ANOTHER AREA OF LIGHT SNOW WILL SHIFT INTO THE DEVILS LAKE BASIN
THIS EVENING AND SOUTHEASTWARD OVERNIGHT...IN ASSOCIATION WITH AN
AREA OF MID-LEVEL FRONTOGENESIS AND SYNOPTIC FORCING IN THE RIGHT
ENTRANCE REGION OF A BROAD UPPER JET. AS THE FORCING GRADUALLY
WEAKENS...A DECREASING TREND IN THE SNOWFALL IS EXPECTED WITH TIME
AS THE SNOW SHIFTS SOUTHWARD. RIGHT NOW THE BEST CHANCE FOR 1 TO 3
INCHES OF ACCUMULATION LOOKS TO BE FROM THE DEVILS LAKE AREA INTO
PARTS OF THE NORTHERN AND CENTRAL VALLEY TONIGHT INTO FRIDAY.
TEMPS TONIGHT MAY BE TRICKY. ALTHOUGH LOW-LEVEL COLD ADVECTION
WILL CONTINUE THROUGH THE NIGHT...HOW MUCH TEMPS FALL WILL DEPEND
ON CLOUD COVERAGE. THE RAP BRINGS SOME LOW-LEVEL DRYING INTO PARTS
OF NORTHWEST MINNESOTA OVERNIGHT. TEMPS COULD DROP PRETTY QUICKLY
IF ANY CLEARING DOES OCCUR...AND THUS HAVE THE LOWEST TEMPS IN
THIS AREA OF NW MINNESOTA. HIGHS ON FRIDAY LIKELY WILL BE COLDEST
NORTH...WITH TEMPS REMAINING BELOW ZERO...AND SINGLE DIGITS ABOVE
ZERO FARTHER SOUTH.
AS WINDS ARE EXPECTED TO STAY UP AROUND 10 KTS OVERNIGHT...WILL
ALSO ISSUE A WIND CHILL ADVISORY FOR MUCH OF NE ND EASTWARD INTO
NW MN FROM 06Z TONIGHT THROUGH 03Z SATURDAY. WITH WINDS BRISK FROM
THE NORTHEAST ON FRIDAY AHEAD OF THE SFC HIGH...HELD ONTO THE
ADVISORY UNTIL FRIDAY EVENING...ALTHOUGH WIND CHILLS MAY RISE ABOVE
CRITERIA FOR A BIT DURING THE DAY. AS THE SFC RIDGE AXIS
APPROACHES FRIDAY NIGHT...WINDS MAY GO LIGHT...ALLOWING FOR WIND
CHILLS TO RISE ABOVE ADVISORY THRESHOLD. THIS WILL BE MONITORED
DURING FUTURE SHIFTS THOUGH.
A SERIES OF UPPER IMPULSES EMBEDDED IN NORTHWEST FLOW ALOFT WILL
CONTINUE TO AFFECT THE AREA FRIDAY NIGHT INTO SATURDAY...BRINGING
CONTINUED CHANCES FOR LIGHT SNOW. ALTHOUGH MODEL QPF IS LOW...WITH
HIGH SNOW RATIOS AND MODEL SOUNDINGS INDICATING A FAIRLY DEEP
SATURATED LAYER...A FLUFFY INCH OR TWO OF SNOW IS
POSSIBLE...DEPENDING ON THE EXACT TRACK OF THE IMPULSES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 PM CST THU DEC 12 2013
TEMPS ON SATURDAY WILL RISE INTO THE SINGLE DIGITS EITHER SIDE OF
ZERO WITH LIGHT SNOW REMAINING POSSIBLE AS UPPER LEVEL ENERGY
CASCADES THROUGH THE FLOW. A SFC RIDGE WILL SPREAD OVER THE AREA
ON SATURDAY NIGHT. THE MAIN QUESTION WILL BE TEMPS...WHICH WILL BE
DEPENDENT ON CLOUD COVER. THUS...TEMPS COULD BE A BIT COLDER IF
SKIES DO CLEAR.
ANOTHER ROUND OF LIGHT SNOW IS POSSIBLE SUNDAY AS WARM AIR ADVECTION
DEVELOPS AND THE LOW-LEVEL BAROCLINIC ZONE APPROACHES FROM THE WEST
AHEAD OF THE NEXT UPPER WAVE. HOWEVER...TEMPS WILL REMAIN WELL
BELOW NORMAL.
FOR THE SUNDAY NIGHT THROUGH THURSDAY PERIOD...12Z ECMWF/GFS/GEM SO
ENOUGH DISAGREEMENT IN TIMING AND LOCATION OF SEVERAL 500 MB SHORT
WAVES/SURFACE LOW PRESSURE SYSTEMS TO KEEP CONFIDENCE IN FCST A BIT
LOWER THAN NORMAL. IDEA IS FOR ONE SHORT WAVE MONDAY TO EXIT
FOLLOWED BY SOME COLDER AIR MON NIGHT-TUE THEN THE NEXT ONE DUE WED
NIGHT-THU TIME FRAME. EXACT PLACEMENT OF LOWS WILL MEAN POTENTIAL
TEMP DIFFERENCES WITH OVERALL 12Z EURO AND GEM A BIT WARMER THAN 12Z
GFS ESP FOR MID WEEK SYSTEM. WITH THE DIFFERENCES STUCK WITH ALL
BLEND GUIDANCE. THERAFTER AND BEYOND THIS PERIOD IS WHEN THE NEXT
ARCTIC OUBREAK WILL OCCUR.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 635 PM CST THU DEC 12 2013
CIGS HAVE BEEN BORDERLINE BETWEEN VFR AND MVFR. THE LEVELS OF THE
CEILINGS WILL SLOWLY DECREASE THROUGHOUT THE PERIOD...ALTHOUGH
THINK THAT THEY WILL STAY MVFR. SOME REDUCTIONS IN VIS AS A SNOW
BAND BUILDS FROM NEAR KDVL TO THE SOUTH AND EAST LATER TONIGHT AND
INTO TOMORROW. THINK THAT AMOUNTS WILL BE FAIRLY LIGHT AND VIS
WILL STAY IN THE 2-5SM RANGE. NORTHWEST WINDS WILL STAY AT AROUND
10 TO 15 KTS.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 PM CST FRIDAY FOR
NDZ006>008-014>016-024-026>030-054.
MN...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO 9 PM CST FRIDAY FOR
MNZ001-002-004>009-013>017-022-023.
&&
$$
UPDATE...JR
SHORT TERM...MAKOWSKI
LONG TERM...RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS TULSA OK
935 PM CST THU DEC 12 2013
...UPDATE...
.DISCUSSION...
QUIET WEATHER SO FAR ACROSS THE REGION THIS
EVENING...ALTHOUGH RADAR ECHOES ACROSS SW OK
CONTINUE TO ADVANCE SLOWLY ENE. HRRR OUTPUT HAS
BEEN VERY CONSISTENT OVER THE PAST SEVERAL HOURS
BRINGING LIGHT PRECIP INTO ERN TOWARD 06Z...AND
EVENTUALLY INTO NW AR 09-12Z. BASED ON THIS AND
CURRENT TRENDS...HAVE UPPED POPS SOME LATER TONIGHT
AND BROUGHT PRECIP INTO NW AR A BIT QUICKER THAN
PREVIOUSLY THOUGHT.
SURFACE TEMPS ALREADY RUNNING AT OR JUST A BIT
BELOW FREEZING ACROSS FAR ERN OK/NW AR...SO ONSET
OF PRECIP IN THESE ARESS WILL LIKELY BE LIGHT
FREEZING RAIN. TOUGHER CALL ON PRECIP TYPE TOWARD
12Z-15Z AS SOUTH WINDS CONTINUE TO INCREASE ALONG
WITH SLOWLY RISING SFC TEMPS.
UPDATE PRODUCTS WILL BE OUT SHORTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TUL 31 43 32 37 / 30 60 30 10
FSM 28 40 35 40 / 10 80 80 20
MLC 32 44 35 40 / 20 70 50 20
BVO 28 42 29 35 / 30 60 30 10
FYV 26 38 31 37 / 20 80 80 20
BYV 26 37 31 36 / 10 80 90 20
MKO 30 42 33 36 / 20 70 50 20
MIO 27 40 30 34 / 20 70 50 10
F10 31 43 34 36 / 30 60 30 10
HHW 33 44 38 44 / 20 80 60 20
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
SHORT TERM...18
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
600 PM CST THU DEC 12 2013
.AVIATION...
VFR SKIES WILL PREVAIL THROUGH THE 13/00Z TAF PERIOD. CIGS AT
BKN-OVC035-050 DEVELOPING ACROSS THE AREA THIS EVENING WITH ISOLD
SHRA DEVELOPING MAINLY OVER THE HILL COUNTRY OVERNIGHT N-NW OF TAF
SITES AS AN UPPER LEVEL TROUGH APPROACHES. ISOLD TO SCT SHRA CAN
BE EXPECTED FRIDAY AS THE UPPER LEVEL TROUGH MOVES ACROSS THE AREA
WITH TEMPO MVFR CIGS/VSBYS. WILL MAINTAIN MENTION AT THE I-35 TAF
SITES. UPPER LEVEL TROUGH MOVES EAST LEADING TO CLEARING SKIES
FRIDAY AFTERNOON WEST AND EVENING EAST. WINDS WILL BECOME S-SE AT
4 TO 8 KTS AT TAF SITES TONIGHT...THEN TURN TO SW FRIDAY EVENING.
&&
.PREV DISCUSSION... /ISSUED 300 PM CST THU DEC 12 2013/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
MID TO UPPER LEVEL CLOUDS ARE COVERING ALL OF SOUTH CENTRAL TEXAS
THIS AFTERNOON AS SOUTHWEST FLOW ALOFT PUSHES MOISTURE ACROSS THE
AREA. THESE CLOUDS WILL LINGER AROUND THROUGH FRIDAY AS AN UPPER
LEVEL TROUGH TRAVELS FROM THE DESERT SOUTHWEST INTO THE SOUTHERN
PLAINS. AT LOWER LEVELS...VISIBLE SATELLITE IMAGES ARE DEPICTING
BROKEN TO OVERCAST SKIES PUSHING TO THE NORTH-NORTHEAST ACROSS THE RIO
GRANDE VALLEY WHILE SPREADING NORTHEASTWARD TOWARD THE SAN ANTONIO
AREA. LATEST RUC SOLUTION HAS THIS LOW LEVEL CLOUD DECK SPREADING
ACROSS MOST AREAS OF SOUTH CENTRAL TEXAS BY MIDNIGHT. OVERNIGHT
LOWS WILL RANGE FROM THE MID TO UPPER 30S HILL COUNTRY TO LOWER
40S REST OF THE AREA. LATE TONIGHT INTO FRIDAY...CHANCES OF RAIN
WILL BE INCREASING AS THE UPPER LEVEL TROUGH ABOVE MENTIONED NEARS
THE SOUTHERN PLAINS. EXPECT SHOWERS TO AFFECT THE NORTHWEST AND
NORTHERN SECTIONS OF SOUTH CENTRAL TEXAS OVERNIGHT WITH SHOWERS
SPREADING EASTWARD ON FRIDAY. RAIN CHANCES WILL COME TO AN END
LATE FRIDAY AS THE UPPER TROUGH PUSHES TO THE EAST. RAINFALL
AMOUNTS WILL GENERALLY BE FROM A FEW HUNDREDTHS TO ONE QUARTER
INCH...ESPECIALLY ACROSS THE NORTHEAST PART OF THE HILL COUNTRY.
LONG TERM (SATURDAY THROUGH THURSDAY)...
A DRY COLD FRONT IS EXPECTED TO PUSH ACROSS SOUTH CENTRAL TEXAS
ON SATURDAY WITH SKIES CLEARING FROM WEST TO EAST BY THE AFTERNOON.
MODERATE NORTHWESTERLY WINDS ARE EXPECTED IN THE WAKE OF THE FRONT
WITH WIND SPEEDS DECREASING LATE SATURDAY INTO SUNDAY. SEVERAL
COOL NIGHTS ARE EXPECTED IN THE WAKE OF THE FRONTAL PASSAGE WITH
OVERNIGHT LOWS IN THE LOWER 30S OVER THE HILL COUNTRY AND MID 30S
REST OF THE AREA ON SUNDAY WITH SIMILAR LOWS MONDAY MORNING.
A NORTHWEST TO ZONAL FLOW ALOFT IS ANTICIPATED FOR MUCH OF NEXT
WEEK WITH DRY AND WARMING WEATHER CONDITIONS IN STORE THROUGH
THURSDAY OF NEXT WEEK. LATEST GFS AND ECMWF SOLUTIONS CONTINUE TO
SHOW ANOTHER ARCTIC AIRMASS ARRIVING TO THE LOCAL AREA BETWEEN
SATURDAY AND SUNDAY...DECEMBER 21 AND 22.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 56 44 55 33 / 10 40 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 37 58 42 56 32 / 10 40 20 10 -
NEW BRAUNFELS MUNI AIRPORT 40 58 44 57 33 / 10 30 20 10 -
BURNET MUNI AIRPORT 37 56 40 52 30 / 20 40 10 - -
DEL RIO INTL AIRPORT 40 63 41 60 34 / 10 10 - 0 -
GEORGETOWN MUNI AIRPORT 37 56 42 52 31 / 20 40 20 10 -
HONDO MUNI AIRPORT 40 60 43 61 32 / 10 30 10 - -
SAN MARCOS MUNI AIRPORT 39 59 44 57 33 / 10 40 20 10 -
LA GRANGE - FAYETTE REGIONAL 41 60 47 57 33 / 10 40 30 10 -
SAN ANTONIO INTL AIRPORT 41 58 45 59 34 / 10 30 20 - -
STINSON MUNI AIRPORT 43 60 46 61 35 / 10 30 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...18
PUBLIC SERVICE/DATA COLLECTION...30
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1141 AM CST WED DEC 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST WED DEC 11 2013
MAIN FORECAST CONCERNS ARE ON WIND CHILLS THROUGH TONIGHT AND
PRECIPITATION CHANCES TONIGHT.
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER RIDGING NEAR THE WEST COAST OF THE U.S....BROAD
TROUGHING OVER THE EAST HALF OF CANADA...AND A SHORTWAVE TROUGH
STRETCHING FROM MN INTO NEBRASKA. AHEAD OF THIS SHORTWAVE TROUGH...A
FRONTOGENESIS BAND OF SNOW ENCOMPASSED MUCH OF EASTERN IOWA INTO
SOUTHERN WI...WHILE CLOUDS COVERED MUCH OF THE FORECAST AREA.
HOWEVER...CLEARING ASSOCIATED WITH SUBSIDENCE IN THE TROUGH WAS
QUICKLY APPROACHING THE FORECAST AREA FROM CENTRAL MN. THIS CLEARING
WAS RIGHT BEHIND A COLD FRONT...WHICH ALSO REPRESENTS AN ARCTIC
AIRMASS POISED TO COME INTO THE AREA TODAY. READINGS ARE BELOW ZERO
FROM NORTH DAKOTA INTO CENTRAL MN...AND IN MANY SPOTS TEENS BELOW
ZERO. 850MB STANDARDIZED TEMPERATURE ANOMALIES ASSOCIATED WITH THIS
ARCTIC AIRMASS ARE 2 BELOW NORMAL. ACCOMPANYING THE ARCTIC AIR ARE
SOME BRISK NORTHWEST WINDS...PARTICULARLY WITH THE ISALLOBARIC PUSH
RIGHT BEHIND THE COLD FRONT. THESE WINDS ARE KNOCKING WIND CHILLS
DOWN TO 20 TO 35 BELOW FROM CENTRAL MN THROUGH NORTHERN WI
NORTHWESTWARD.
THE COLD AIR AND CLEARING SEEN OVER CENTRAL MN WILL RUSH INTO THE
FORECAST AREA QUICKLY THIS MORNING...ASSOCIATED WITH THE COLD
FRONTAL AND SHORTWAVE TROUGH PASSAGE. WINDS SHOULD STAY BRISK ALL
DAY AS A SURFACE OVER THE WESTERN DAKOTAS ENDS UP SLIDING WELL TO
OUR SOUTH...INTO NORTHERN MO BY 00Z. THE STRONGEST WINDS ARE LIKELY
THIS MORNING AS PRESSURES RISE RAPIDLY. TEMPERATURES LOOK TO FALL
THROUGH MID MORNING...MAY GET A LITTLE BUMP UP EARLY THIS AFTERNOON
WITH DAYTIME HEATING...AND FALL YET AGAIN ONCE THE SUN STARTS GOING
DOWN. THUS...ITS GOING TO BE TOUGH TO WARM TODAY. HIGHS IN THE
SINGLE DIGITS ABOVE ZERO APPEARS TO BE ALL WE CAN GET...WITH
LOCATIONS NORTH OF HIGHWAY 10 NOT EVEN REACHING ZERO. FACTOR IN THE
WIND AND MUCH OF THE AREA WILL SEE WIND CHILLS REACHING 20 BELOW
ZERO OR COLDER AT TIMES...ESPECIALLY THIS MORNING AND LATE TODAY.
REGARDING HAZARDS...LIKELY SOMETIME BETWEEN 12-13Z TODAY WE CAN
TRANSITION THE WINTER WEATHER ADVISORY OVER TO A WIND CHILL
ADVISORY IN NORTHEAST IOWA.
THIS SHOT OF ARCTIC AIR APPEARS TO BE SHORT-LIVED...HOWEVER. A
SHORTWAVE SEEN OVER ALBERTA IS PROGGED BY MODELS TO DROP DOWN
THROUGH CENTRAL MN AND WI BETWEEN 06-12Z TONIGHT. THE APPROACH OF
THE SHORTWAVE HELPS TO SWING WINDS AROUND TO THE SOUTHWEST...AND
SPREAD SOME MID/HIGH CLOUDS INTO THE AREA RESULTING FROM DPVA AND
ISENTROPIC LIFT. SO AFTER SOME COOLING FROM RADIATIONAL PROCESSES IN
THE EVENING...ADVECTIVE PROCESSES WILL HELP TEMPERATURES CLIMB
THEREAFTER. GIVEN THE COLD EVENING...EXTENDED THE WIND CHILL
ADVISORY THROUGH 12Z THU FOR SOUTHEAST MN INTO SOUTHWEST AND
CENTRAL WI. EXPANDED BOTH IN TIME AND AREA THE ADVISORY TO HELP
BLEND WITH MKX AND DVN OFFICES. THE NEXT QUESTION IS IF ANY SNOW
CAN FALL WITH THE SHORTWAVE. THE 11.00Z GFS/CANADIAN/ECMWF ALL
PRODUCE A BAND OF LIGHT QPF...WITH SOUNDINGS SUGGESTING THE
FORCING IS MOSTLY CO- LOCATED WITH THE DENDRITIC GROWTH ZONE. THE
AFOREMENTIONED MODELS ALL SUGGEST A QUICK MOVING BAND...LIMITING
ACCUMULATIONS...BUT A FEW TENTHS SEEM REASONABLE. HAVE RAISED
PRECIPITATION CHANCES TOWARDS 60. NAM IS THE ONLY MODEL NOT
SHOWING ANY PRECIPITATION...BUT EVEN IT HAS INDICATIONS OF THE
FORCING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 334 AM CST WED DEC 11 2013
MAIN LONG TERM FORECAST CONCERNS ARE ON MINIMAL PRECIPITATION
CHANCES THROUGHOUT.
SOME DEAMPLIFICATION OF THE FLOW ACROSS THE NORTHERN U.S. IS PROGGED
TO OCCUR THURSDAY THROUGH FRIDAY IN RESPONSE TO A TROUGH DROPPING
DOWN THROUGH THE PACIFIC NORTHWEST. THE SWITCH TO A ZONAL FLOW
PATTERN IN THE NORTHERN STREAM APPEARS TO HAVE PLENTY OF MID/UPPER
LEVEL MOISTURE...WHICH IS GOING TO MANIFEST ITSELF IN A LOT OF
CLOUDS. PRECIPITATION CHANCES OVERALL LOOK PRETTY MINIMAL...
THOUGH...AS PLENTIFUL DRY LOW LEVEL AIR IS IN PLACE. ADDITIONALLY...
FORCING APPEARS RESTRICTED TO SOME WEAK MID LEVEL FRONTOGENESIS
STRETCHING FROM NORTHERN/CENTRAL MN INTO NORTHERN WI THU NIGHT AND
FRIDAY. THIS FORCING COULD SQUEEZE OUT SOME SNOW...BUT CONFIDENCE IS
ONLY HIGH ENOUGH FOR A 20 PERCENT CHANCE NORTH OF HIGHWAY 10.
REGARDING THAT AFOREMENTIONED FRONTOGENESIS...THIS WILL OCCUR BEHIND
A COLD FRONTAL PASSAGE PROGGED TO MOVE THROUGH THE AREA THU NIGHT.
SO AFTER A WARMER THURSDAY IN RESPONSE TO LOW LEVEL WARM
ADVECTION...TEMPERATURES HEAD BACK DOWN THU NIGHT...BUT NOT NEARLY
AS COLD AS IT HAS BEEN. DESPITE THE COLD ADVECTION...TEMPERATURES
FRIDAY SHOULD REBOUND CLOSE TO THURSDAYS HIGHS.
FOR FRIDAY NIGHT AND SATURDAY...THE FOCUS HAS BEEN ON A SHORTWAVE
TROUGH AND GENERAL SYSTEM COMING OUT OF THE CENTRAL PLAINS. THIS
SHORTWAVE TROUGH IS CURRENTLY AN UPPER LOW SITTING OFF THE FAR
SOUTHERN CALIFORNIA COAST. 11.00Z ECMWF/GFS/CANADIAN HAVE TRENDED
SLIGHTLY FARTHER SOUTHEAST WITH THIS SYSTEM...AND AS SUCH...THE
PRECIPITATION ALSO MOVED A LITTLE FARTHER AWAY. THERE STILL ARE
INDICATIONS THAT THE MID LEVEL FRONTOGENESIS SITTING OVER NORTHERN
WI ON FRIDAY WILL SLIDE SOUTH OVER THE REST OF THE AREA FRIDAY
NIGHT...POSSIBLY SQUEEZING OUT A LITTLE LIGHT SNOW.
THEREFORE...HAVE HAD TO MAINTAIN SOME 20-40 PERCENT
CHANCES...HIGHEST BETWEEN 06-12Z SATURDAY. CHANCES CONTINUE
THROUGH THE DAY SATURDAY AND INTO SATURDAY NIGHT...MORE IN
RESPONSE TO A POTENT SHORTWAVE TROUGH DROPPING DOWN FROM MANITOBA
INTO UPPER MICHIGAN.
FOR SUNDAY AND BEYOND...SUNDAY IS LOOKING CHILLY AS THE POTENT
TROUGH BRINGS DOWN A BRIEF SHOT OF ARCTIC AIR WITH IT ON ITS BACK
SIDE. 850MB TEMPS FALL TO -14 TO -20C AT 18Z SUNDAY PER 11.00Z
ECMWF...COLDEST OVER TAYLOR COUNTY. MAY GET CLOSE FOR NEEDING A WIND
CHILL ADVISORY SUNDAY MORNING. A WARM ADVECTION PATTERN THEN LOOKS
TO ENSUE FOR SUNDAY NIGHT INTO MONDAY AS YET ANOTHER DECENT
SHORTWAVE TROUGH TRACKS FROM MANITOBA INTO UPPER MICHIGAN. FOLLOWED
CONSENSUS AND INCLUDED 20 PERCENT CHANCES FOR MONDAY. TEMPERATURES
MAY REBOUND HIGHER TOO THAN CURRENTLY FORECAST...BUT GIVEN HOW FAR
OUT THIS PERIOD IS IN THE FORECAST...STAYED CLOSER TO A MODEL
CONSENSUS WITH HIGHS IN THE 15-20 RANGE.
FOR THOSE LOOKING FOR A WARM-UP...THE ECMWF CONTINUES TO HINT AT ONE
FOR THE MIDDLE TO END OF NEXT WEEK AS A DEEP TROUGH FORMS OVER THE
WESTERN U.S.. THE CFS HAS ALSO BEEN ADVERTISING ABOVE NORMAL
TEMPERATURES DURING THIS SAME TIME PERIOD.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z THURSDAY AFTERNOON)
ISSUED AT 1141 AM CST WED DEC 11 2013
COLD CYLCONIC NORTHWEST FLOW ALOFT WILL USHER IN ANOTHER WEAK
SHORTWAVE TROUGH INTO THE REGION THIS EVENING/OVERNIGHT. PLAN ON
VFR CONDITIONS TO DETERIORATE INTO MVFR RANGE AS THIS WAVE
APPROACHES IN THE 06-08Z TIME FRAME AS CLOUD HEIGHTS LOWER AND
VISIBILITY GETS REDUCED IN FALLING LIGHT SNOW. EXPECTING KLSE TO
BE IMPACTED BY THE FALLING SNOW MORE THAN KRST. NOT EXPECTING MORE
THAN 1/4-1/2 INCH. IT APPEARS THE LIGHT SNOW WILL EXIT EAST OF
THE AREA SOON AFTER DAYBREAK WITH LINGERING MVFR/IFR STRATUS
THROUGH THE REST OF THE MORNING HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR WIZ017-029-
032>034-041>044.
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST THURSDAY
FOR WIZ053>055-061.
MN...WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR MNZ079-086>088-
094>096.
IA...WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR IAZ008>010-018-
019-029.
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST THURSDAY
FOR IAZ011-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...DAS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
800 AM CST WED DEC 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST WED DEC 11 2013
MAIN FORECAST CONCERNS ARE ON WIND CHILLS THROUGH TONIGHT AND
PRECIPITATION CHANCES TONIGHT.
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER RIDGING NEAR THE WEST COAST OF THE U.S....BROAD
TROUGHING OVER THE EAST HALF OF CANADA...AND A SHORTWAVE TROUGH
STRETCHING FROM MN INTO NEBRASKA. AHEAD OF THIS SHORTWAVE TROUGH...A
FRONTOGENESIS BAND OF SNOW ENCOMPASSED MUCH OF EASTERN IOWA INTO
SOUTHERN WI...WHILE CLOUDS COVERED MUCH OF THE FORECAST AREA.
HOWEVER...CLEARING ASSOCIATED WITH SUBSIDENCE IN THE TROUGH WAS
QUICKLY APPROACHING THE FORECAST AREA FROM CENTRAL MN. THIS CLEARING
WAS RIGHT BEHIND A COLD FRONT...WHICH ALSO REPRESENTS AN ARCTIC
AIRMASS POISED TO COME INTO THE AREA TODAY. READINGS ARE BELOW ZERO
FROM NORTH DAKOTA INTO CENTRAL MN...AND IN MANY SPOTS TEENS BELOW
ZERO. 850MB STANDARDIZED TEMPERATURE ANOMALIES ASSOCIATED WITH THIS
ARCTIC AIRMASS ARE 2 BELOW NORMAL. ACCOMPANYING THE ARCTIC AIR ARE
SOME BRISK NORTHWEST WINDS...PARTICULARLY WITH THE ISALLOBARIC PUSH
RIGHT BEHIND THE COLD FRONT. THESE WINDS ARE KNOCKING WIND CHILLS
DOWN TO 20 TO 35 BELOW FROM CENTRAL MN THROUGH NORTHERN WI
NORTHWESTWARD.
THE COLD AIR AND CLEARING SEEN OVER CENTRAL MN WILL RUSH INTO THE
FORECAST AREA QUICKLY THIS MORNING...ASSOCIATED WITH THE COLD
FRONTAL AND SHORTWAVE TROUGH PASSAGE. WINDS SHOULD STAY BRISK ALL
DAY AS A SURFACE OVER THE WESTERN DAKOTAS ENDS UP SLIDING WELL TO
OUR SOUTH...INTO NORTHERN MO BY 00Z. THE STRONGEST WINDS ARE LIKELY
THIS MORNING AS PRESSURES RISE RAPIDLY. TEMPERATURES LOOK TO FALL
THROUGH MID MORNING...MAY GET A LITTLE BUMP UP EARLY THIS AFTERNOON
WITH DAYTIME HEATING...AND FALL YET AGAIN ONCE THE SUN STARTS GOING
DOWN. THUS...ITS GOING TO BE TOUGH TO WARM TODAY. HIGHS IN THE
SINGLE DIGITS ABOVE ZERO APPEARS TO BE ALL WE CAN GET...WITH
LOCATIONS NORTH OF HIGHWAY 10 NOT EVEN REACHING ZERO. FACTOR IN THE
WIND AND MUCH OF THE AREA WILL SEE WIND CHILLS REACHING 20 BELOW
ZERO OR COLDER AT TIMES...ESPECIALLY THIS MORNING AND LATE TODAY.
REGARDING HAZARDS...LIKELY SOMETIME BETWEEN 12-13Z TODAY WE CAN
TRANSITION THE WINTER WEATHER ADVISORY OVER TO A WIND CHILL
ADVISORY IN NORTHEAST IOWA.
THIS SHOT OF ARCTIC AIR APPEARS TO BE SHORT-LIVED...HOWEVER. A
SHORTWAVE SEEN OVER ALBERTA IS PROGGED BY MODELS TO DROP DOWN
THROUGH CENTRAL MN AND WI BETWEEN 06-12Z TONIGHT. THE APPROACH OF
THE SHORTWAVE HELPS TO SWING WINDS AROUND TO THE SOUTHWEST...AND
SPREAD SOME MID/HIGH CLOUDS INTO THE AREA RESULTING FROM DPVA AND
ISENTROPIC LIFT. SO AFTER SOME COOLING FROM RADIATIONAL PROCESSES IN
THE EVENING...ADVECTIVE PROCESSES WILL HELP TEMPERATURES CLIMB
THEREAFTER. GIVEN THE COLD EVENING...EXTENDED THE WIND CHILL
ADVISORY THROUGH 12Z THU FOR SOUTHEAST MN INTO SOUTHWEST AND
CENTRAL WI. EXPANDED BOTH IN TIME AND AREA THE ADVISORY TO HELP
BLEND WITH MKX AND DVN OFFICES. THE NEXT QUESTION IS IF ANY SNOW
CAN FALL WITH THE SHORTWAVE. THE 11.00Z GFS/CANADIAN/ECMWF ALL
PRODUCE A BAND OF LIGHT QPF...WITH SOUNDINGS SUGGESTING THE
FORCING IS MOSTLY CO- LOCATED WITH THE DENDRITIC GROWTH ZONE. THE
AFOREMENTIONED MODELS ALL SUGGEST A QUICK MOVING BAND...LIMITING
ACCUMULATIONS...BUT A FEW TENTHS SEEM REASONABLE. HAVE RAISED
PRECIPITATION CHANCES TOWARDS 60. NAM IS THE ONLY MODEL NOT
SHOWING ANY PRECIPITATION...BUT EVEN IT HAS INDICATIONS OF THE
FORCING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 334 AM CST WED DEC 11 2013
MAIN LONG TERM FORECAST CONCERNS ARE ON MINIMAL PRECIPITATION
CHANCES THROUGHOUT.
SOME DEAMPLIFICATION OF THE FLOW ACROSS THE NORTHERN U.S. IS PROGGED
TO OCCUR THURSDAY THROUGH FRIDAY IN RESPONSE TO A TROUGH DROPPING
DOWN THROUGH THE PACIFIC NORTHWEST. THE SWITCH TO A ZONAL FLOW
PATTERN IN THE NORTHERN STREAM APPEARS TO HAVE PLENTY OF MID/UPPER
LEVEL MOISTURE...WHICH IS GOING TO MANIFEST ITSELF IN A LOT OF
CLOUDS. PRECIPITATION CHANCES OVERALL LOOK PRETTY MINIMAL...
THOUGH...AS PLENTIFUL DRY LOW LEVEL AIR IS IN PLACE. ADDITIONALLY...
FORCING APPEARS RESTRICTED TO SOME WEAK MID LEVEL FRONTOGENESIS
STRETCHING FROM NORTHERN/CENTRAL MN INTO NORTHERN WI THU NIGHT AND
FRIDAY. THIS FORCING COULD SQUEEZE OUT SOME SNOW...BUT CONFIDENCE IS
ONLY HIGH ENOUGH FOR A 20 PERCENT CHANCE NORTH OF HIGHWAY 10.
REGARDING THAT AFOREMENTIONED FRONTOGENESIS...THIS WILL OCCUR BEHIND
A COLD FRONTAL PASSAGE PROGGED TO MOVE THROUGH THE AREA THU NIGHT.
SO AFTER A WARMER THURSDAY IN RESPONSE TO LOW LEVEL WARM
ADVECTION...TEMPERATURES HEAD BACK DOWN THU NIGHT...BUT NOT NEARLY
AS COLD AS IT HAS BEEN. DESPITE THE COLD ADVECTION...TEMPERATURES
FRIDAY SHOULD REBOUND CLOSE TO THURSDAYS HIGHS.
FOR FRIDAY NIGHT AND SATURDAY...THE FOCUS HAS BEEN ON A SHORTWAVE
TROUGH AND GENERAL SYSTEM COMING OUT OF THE CENTRAL PLAINS. THIS
SHORTWAVE TROUGH IS CURRENTLY AN UPPER LOW SITTING OFF THE FAR
SOUTHERN CALIFORNIA COAST. 11.00Z ECMWF/GFS/CANADIAN HAVE TRENDED
SLIGHTLY FARTHER SOUTHEAST WITH THIS SYSTEM...AND AS SUCH...THE
PRECIPITATION ALSO MOVED A LITTLE FARTHER AWAY. THERE STILL ARE
INDICATIONS THAT THE MID LEVEL FRONTOGENESIS SITTING OVER NORTHERN
WI ON FRIDAY WILL SLIDE SOUTH OVER THE REST OF THE AREA FRIDAY
NIGHT...POSSIBLY SQUEEZING OUT A LITTLE LIGHT SNOW.
THEREFORE...HAVE HAD TO MAINTAIN SOME 20-40 PERCENT
CHANCES...HIGHEST BETWEEN 06-12Z SATURDAY. CHANCES CONTINUE
THROUGH THE DAY SATURDAY AND INTO SATURDAY NIGHT...MORE IN
RESPONSE TO A POTENT SHORTWAVE TROUGH DROPPING DOWN FROM MANITOBA
INTO UPPER MICHIGAN.
FOR SUNDAY AND BEYOND...SUNDAY IS LOOKING CHILLY AS THE POTENT
TROUGH BRINGS DOWN A BRIEF SHOT OF ARCTIC AIR WITH IT ON ITS BACK
SIDE. 850MB TEMPS FALL TO -14 TO -20C AT 18Z SUNDAY PER 11.00Z
ECMWF...COLDEST OVER TAYLOR COUNTY. MAY GET CLOSE FOR NEEDING A WIND
CHILL ADVISORY SUNDAY MORNING. A WARM ADVECTION PATTERN THEN LOOKS
TO ENSUE FOR SUNDAY NIGHT INTO MONDAY AS YET ANOTHER DECENT
SHORTWAVE TROUGH TRACKS FROM MANITOBA INTO UPPER MICHIGAN. FOLLOWED
CONSENSUS AND INCLUDED 20 PERCENT CHANCES FOR MONDAY. TEMPERATURES
MAY REBOUND HIGHER TOO THAN CURRENTLY FORECAST...BUT GIVEN HOW FAR
OUT THIS PERIOD IS IN THE FORECAST...STAYED CLOSER TO A MODEL
CONSENSUS WITH HIGHS IN THE 15-20 RANGE.
FOR THOSE LOOKING FOR A WARM-UP...THE ECMWF CONTINUES TO HINT AT ONE
FOR THE MIDDLE TO END OF NEXT WEEK AS A DEEP TROUGH FORMS OVER THE
WESTERN U.S.. THE CFS HAS ALSO BEEN ADVERTISING ABOVE NORMAL
TEMPERATURES DURING THIS SAME TIME PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 532 AM CST WED DEC 11 2013
PATCHY BLOWING SNOW IS POSSIBLE AT KRST EARLY THIS
MORNING...OTHERWISE VFR CONDITIONS ARE EXPECTED AT THE TAF SITES
THROUGH THIS EVENING. PLAN ON NORTHWEST WINDS OF 12 TO 14 KTS
THIS MORNING...THEN DIMINISHING INTO THE 8 TO 10 KT RANGE THIS
AFTERNOON AND BECOMING WESTERLY. A FAST MOVING UPPER LEVEL
DISTURBANCE WILL MOVE ACROSS THE AREA LATE TONIGHT BRINGING LIGHT
SNOW OR FLURRIES TO THE TAF SITES. MVFR CONDITIONS ARE POSSIBLE
TONIGHT IN THE SNOW WITH VISIBILITIES IN THE 4 TO 5 SM RANGE AND
CEILINGS LOWERING TO AROUND 2 KFT. THE SNOW LOOKS TO START AT KRST
AROUND 08Z AND AT KLSE AROUND 09Z. MOST OF THE SNOW SHOULD PASS
NORTHEAST OF THE TAF SITES BUT WILL HAVE TO KEEP A CLOSE EYE ON
THIS SYSTEM THIS EVENING INTO THE OVERNIGHT HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR WIZ017-029-
032>034-041>044.
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST THURSDAY
FOR WIZ053>055-061.
MN...WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR MNZ079-086>088-
094>096.
IA...WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR IAZ008>010-018-
019-029.
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST THURSDAY
FOR IAZ011-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
532 AM CST WED DEC 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST WED DEC 11 2013
MAIN FORECAST CONCERNS ARE ON WIND CHILLS THROUGH TONIGHT AND
PRECIPITATION CHANCES TONIGHT.
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER RIDGING NEAR THE WEST COAST OF THE U.S....BROAD
TROUGHING OVER THE EAST HALF OF CANADA...AND A SHORTWAVE TROUGH
STRETCHING FROM MN INTO NEBRASKA. AHEAD OF THIS SHORTWAVE TROUGH...A
FRONTOGENESIS BAND OF SNOW ENCOMPASSED MUCH OF EASTERN IOWA INTO
SOUTHERN WI...WHILE CLOUDS COVERED MUCH OF THE FORECAST AREA.
HOWEVER...CLEARING ASSOCIATED WITH SUBSIDENCE IN THE TROUGH WAS
QUICKLY APPROACHING THE FORECAST AREA FROM CENTRAL MN. THIS CLEARING
WAS RIGHT BEHIND A COLD FRONT...WHICH ALSO REPRESENTS AN ARCTIC
AIRMASS POISED TO COME INTO THE AREA TODAY. READINGS ARE BELOW ZERO
FROM NORTH DAKOTA INTO CENTRAL MN...AND IN MANY SPOTS TEENS BELOW
ZERO. 850MB STANDARDIZED TEMPERATURE ANOMALIES ASSOCIATED WITH THIS
ARCTIC AIRMASS ARE 2 BELOW NORMAL. ACCOMPANYING THE ARCTIC AIR ARE
SOME BRISK NORTHWEST WINDS...PARTICULARLY WITH THE ISALLOBARIC PUSH
RIGHT BEHIND THE COLD FRONT. THESE WINDS ARE KNOCKING WIND CHILLS
DOWN TO 20 TO 35 BELOW FROM CENTRAL MN THROUGH NORTHERN WI
NORTHWESTWARD.
THE COLD AIR AND CLEARING SEEN OVER CENTRAL MN WILL RUSH INTO THE
FORECAST AREA QUICKLY THIS MORNING...ASSOCIATED WITH THE COLD
FRONTAL AND SHORTWAVE TROUGH PASSAGE. WINDS SHOULD STAY BRISK ALL
DAY AS A SURFACE OVER THE WESTERN DAKOTAS ENDS UP SLIDING WELL TO
OUR SOUTH...INTO NORTHERN MO BY 00Z. THE STRONGEST WINDS ARE LIKELY
THIS MORNING AS PRESSURES RISE RAPIDLY. TEMPERATURES LOOK TO FALL
THROUGH MID MORNING...MAY GET A LITTLE BUMP UP EARLY THIS AFTERNOON
WITH DAYTIME HEATING...AND FALL YET AGAIN ONCE THE SUN STARTS GOING
DOWN. THUS...ITS GOING TO BE TOUGH TO WARM TODAY. HIGHS IN THE
SINGLE DIGITS ABOVE ZERO APPEARS TO BE ALL WE CAN GET...WITH
LOCATIONS NORTH OF HIGHWAY 10 NOT EVEN REACHING ZERO. FACTOR IN THE
WIND AND MUCH OF THE AREA WILL SEE WIND CHILLS REACHING 20 BELOW
ZERO OR COLDER AT TIMES...ESPECIALLY THIS MORNING AND LATE TODAY.
REGARDING HAZARDS...LIKELY SOMETIME BETWEEN 12-13Z TODAY WE CAN
TRANSITION THE WINTER WEATHER ADVISORY OVER TO A WIND CHILL
ADVISORY IN NORTHEAST IOWA.
THIS SHOT OF ARCTIC AIR APPEARS TO BE SHORT-LIVED...HOWEVER. A
SHORTWAVE SEEN OVER ALBERTA IS PROGGED BY MODELS TO DROP DOWN
THROUGH CENTRAL MN AND WI BETWEEN 06-12Z TONIGHT. THE APPROACH OF
THE SHORTWAVE HELPS TO SWING WINDS AROUND TO THE SOUTHWEST...AND
SPREAD SOME MID/HIGH CLOUDS INTO THE AREA RESULTING FROM DPVA AND
ISENTROPIC LIFT. SO AFTER SOME COOLING FROM RADIATIONAL PROCESSES IN
THE EVENING...ADVECTIVE PROCESSES WILL HELP TEMPERATURES CLIMB
THEREAFTER. GIVEN THE COLD EVENING...EXTENDED THE WIND CHILL
ADVISORY THROUGH 12Z THU FOR SOUTHEAST MN INTO SOUTHWEST AND
CENTRAL WI. EXPANDED BOTH IN TIME AND AREA THE ADVISORY TO HELP
BLEND WITH MKX AND DVN OFFICES. THE NEXT QUESTION IS IF ANY SNOW
CAN FALL WITH THE SHORTWAVE. THE 11.00Z GFS/CANADIAN/ECMWF ALL
PRODUCE A BAND OF LIGHT QPF...WITH SOUNDINGS SUGGESTING THE
FORCING IS MOSTLY CO- LOCATED WITH THE DENDRITIC GROWTH ZONE. THE
AFOREMENTIONED MODELS ALL SUGGEST A QUICK MOVING BAND...LIMITING
ACCUMULATIONS...BUT A FEW TENTHS SEEM REASONABLE. HAVE RAISED
PRECIPITATION CHANCES TOWARDS 60. NAM IS THE ONLY MODEL NOT
SHOWING ANY PRECIPITATION...BUT EVEN IT HAS INDICATIONS OF THE
FORCING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 334 AM CST WED DEC 11 2013
MAIN LONG TERM FORECAST CONCERNS ARE ON MINIMAL PRECIPITATION
CHANCES THROUGHOUT.
SOME DEAMPLIFICATION OF THE FLOW ACROSS THE NORTHERN U.S. IS PROGGED
TO OCCUR THURSDAY THROUGH FRIDAY IN RESPONSE TO A TROUGH DROPPING
DOWN THROUGH THE PACIFIC NORTHWEST. THE SWITCH TO A ZONAL FLOW
PATTERN IN THE NORTHERN STREAM APPEARS TO HAVE PLENTY OF MID/UPPER
LEVEL MOISTURE...WHICH IS GOING TO MANIFEST ITSELF IN A LOT OF
CLOUDS. PRECIPITATION CHANCES OVERALL LOOK PRETTY MINIMAL...
THOUGH...AS PLENTIFUL DRY LOW LEVEL AIR IS IN PLACE. ADDITIONALLY...
FORCING APPEARS RESTRICTED TO SOME WEAK MID LEVEL FRONTOGENESIS
STRETCHING FROM NORTHERN/CENTRAL MN INTO NORTHERN WI THU NIGHT AND
FRIDAY. THIS FORCING COULD SQUEEZE OUT SOME SNOW...BUT CONFIDENCE IS
ONLY HIGH ENOUGH FOR A 20 PERCENT CHANCE NORTH OF HIGHWAY 10.
REGARDING THAT AFOREMENTIONED FRONTOGENESIS...THIS WILL OCCUR BEHIND
A COLD FRONTAL PASSAGE PROGGED TO MOVE THROUGH THE AREA THU NIGHT.
SO AFTER A WARMER THURSDAY IN RESPONSE TO LOW LEVEL WARM
ADVECTION...TEMPERATURES HEAD BACK DOWN THU NIGHT...BUT NOT NEARLY
AS COLD AS IT HAS BEEN. DESPITE THE COLD ADVECTION...TEMPERATURES
FRIDAY SHOULD REBOUND CLOSE TO THURSDAYS HIGHS.
FOR FRIDAY NIGHT AND SATURDAY...THE FOCUS HAS BEEN ON A SHORTWAVE
TROUGH AND GENERAL SYSTEM COMING OUT OF THE CENTRAL PLAINS. THIS
SHORTWAVE TROUGH IS CURRENTLY AN UPPER LOW SITTING OFF THE FAR
SOUTHERN CALIFORNIA COAST. 11.00Z ECMWF/GFS/CANADIAN HAVE TRENDED
SLIGHTLY FARTHER SOUTHEAST WITH THIS SYSTEM...AND AS SUCH...THE
PRECIPITATION ALSO MOVED A LITTLE FARTHER AWAY. THERE STILL ARE
INDICATIONS THAT THE MID LEVEL FRONTOGENESIS SITTING OVER NORTHERN
WI ON FRIDAY WILL SLIDE SOUTH OVER THE REST OF THE AREA FRIDAY
NIGHT...POSSIBLY SQUEEZING OUT A LITTLE LIGHT SNOW.
THEREFORE...HAVE HAD TO MAINTAIN SOME 20-40 PERCENT
CHANCES...HIGHEST BETWEEN 06-12Z SATURDAY. CHANCES CONTINUE
THROUGH THE DAY SATURDAY AND INTO SATURDAY NIGHT...MORE IN
RESPONSE TO A POTENT SHORTWAVE TROUGH DROPPING DOWN FROM MANITOBA
INTO UPPER MICHIGAN.
FOR SUNDAY AND BEYOND...SUNDAY IS LOOKING CHILLY AS THE POTENT
TROUGH BRINGS DOWN A BRIEF SHOT OF ARCTIC AIR WITH IT ON ITS BACK
SIDE. 850MB TEMPS FALL TO -14 TO -20C AT 18Z SUNDAY PER 11.00Z
ECMWF...COLDEST OVER TAYLOR COUNTY. MAY GET CLOSE FOR NEEDING A WIND
CHILL ADVISORY SUNDAY MORNING. A WARM ADVECTION PATTERN THEN LOOKS
TO ENSUE FOR SUNDAY NIGHT INTO MONDAY AS YET ANOTHER DECENT
SHORTWAVE TROUGH TRACKS FROM MANITOBA INTO UPPER MICHIGAN. FOLLOWED
CONSENSUS AND INCLUDED 20 PERCENT CHANCES FOR MONDAY. TEMPERATURES
MAY REBOUND HIGHER TOO THAN CURRENTLY FORECAST...BUT GIVEN HOW FAR
OUT THIS PERIOD IS IN THE FORECAST...STAYED CLOSER TO A MODEL
CONSENSUS WITH HIGHS IN THE 15-20 RANGE.
FOR THOSE LOOKING FOR A WARM-UP...THE ECMWF CONTINUES TO HINT AT ONE
FOR THE MIDDLE TO END OF NEXT WEEK AS A DEEP TROUGH FORMS OVER THE
WESTERN U.S.. THE CFS HAS ALSO BEEN ADVERTISING ABOVE NORMAL
TEMPERATURES DURING THIS SAME TIME PERIOD.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z THURSDAY MORNING)
ISSUED AT 532 AM CST WED DEC 11 2013
PATCHY BLOWING SNOW IS POSSIBLE AT KRST EARLY THIS
MORNING...OTHERWISE VFR CONDITIONS ARE EXPECTED AT THE TAF SITES
THROUGH THIS EVENING. PLAN ON NORTHWEST WINDS OF 12 TO 14 KTS
THIS MORNING...THEN DIMINISHING INTO THE 8 TO 10 KT RANGE THIS
AFTERNOON AND BECOMING WESTERLY. A FAST MOVING UPPER LEVEL
DISTURBANCE WILL MOVE ACROSS THE AREA LATE TONIGHT BRINGING LIGHT
SNOW OR FLURRIES TO THE TAF SITES. MVFR CONDITIONS ARE POSSIBLE
TONIGHT IN THE SNOW WITH VISIBILITIES IN THE 4 TO 5 SM RANGE AND
CEILINGS LOWERING TO AROUND 2 KFT. THE SNOW LOOKS TO START AT KRST
AROUND 08Z AND AT KLSE AROUND 09Z. MOST OF THE SNOW SHOULD PASS
NORTHEAST OF THE TAF SITES BUT WILL HAVE TO KEEP A CLOSE EYE ON
THIS SYSTEM THIS EVENING INTO THE OVERNIGHT HOURS.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ054-
061.
WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR WIZ017-029-
032>034-041>044.
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST THURSDAY
FOR WIZ053-055.
MN...WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR MNZ079-086>088-
094>096.
IA...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
334 AM CST WED DEC 11 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 334 AM CST WED DEC 11 2013
MAIN FORECAST CONCERNS ARE ON WIND CHILLS THROUGH TONIGHT AND
PRECIPITATION CHANCES TONIGHT.
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED UPPER RIDGING NEAR THE WEST COAST OF THE U.S....BROAD
TROUGHING OVER THE EAST HALF OF CANADA...AND A SHORTWAVE TROUGH
STRETCHING FROM MN INTO NEBRASKA. AHEAD OF THIS SHORTWAVE TROUGH...A
FRONTOGENESIS BAND OF SNOW ENCOMPASSED MUCH OF EASTERN IOWA INTO
SOUTHERN WI...WHILE CLOUDS COVERED MUCH OF THE FORECAST AREA.
HOWEVER...CLEARING ASSOCIATED WITH SUBSIDENCE IN THE TROUGH WAS
QUICKLY APPROACHING THE FORECAST AREA FROM CENTRAL MN. THIS CLEARING
WAS RIGHT BEHIND A COLD FRONT...WHICH ALSO REPRESENTS AN ARCTIC
AIRMASS POISED TO COME INTO THE AREA TODAY. READINGS ARE BELOW ZERO
FROM NORTH DAKOTA INTO CENTRAL MN...AND IN MANY SPOTS TEENS BELOW
ZERO. 850MB STANDARDIZED TEMPERATURE ANOMALIES ASSOCIATED WITH THIS
ARCTIC AIRMASS ARE 2 BELOW NORMAL. ACCOMPANYING THE ARCTIC AIR ARE
SOME BRISK NORTHWEST WINDS...PARTICULARLY WITH THE ISALLOBARIC PUSH
RIGHT BEHIND THE COLD FRONT. THESE WINDS ARE KNOCKING WIND CHILLS
DOWN TO 20 TO 35 BELOW FROM CENTRAL MN THROUGH NORTHERN WI
NORTHWESTWARD.
THE COLD AIR AND CLEARING SEEN OVER CENTRAL MN WILL RUSH INTO THE
FORECAST AREA QUICKLY THIS MORNING...ASSOCIATED WITH THE COLD
FRONTAL AND SHORTWAVE TROUGH PASSAGE. WINDS SHOULD STAY BRISK ALL
DAY AS A SURFACE OVER THE WESTERN DAKOTAS ENDS UP SLIDING WELL TO
OUR SOUTH...INTO NORTHERN MO BY 00Z. THE STRONGEST WINDS ARE LIKELY
THIS MORNING AS PRESSURES RISE RAPIDLY. TEMPERATURES LOOK TO FALL
THROUGH MID MORNING...MAY GET A LITTLE BUMP UP EARLY THIS AFTERNOON
WITH DAYTIME HEATING...AND FALL YET AGAIN ONCE THE SUN STARTS GOING
DOWN. THUS...ITS GOING TO BE TOUGH TO WARM TODAY. HIGHS IN THE
SINGLE DIGITS ABOVE ZERO APPEARS TO BE ALL WE CAN GET...WITH
LOCATIONS NORTH OF HIGHWAY 10 NOT EVEN REACHING ZERO. FACTOR IN THE
WIND AND MUCH OF THE AREA WILL SEE WIND CHILLS REACHING 20 BELOW
ZERO OR COLDER AT TIMES...ESPECIALLY THIS MORNING AND LATE TODAY.
REGARDING HAZARDS...LIKELY SOMETIME BETWEEN 12-13Z TODAY WE CAN
TRANSITION THE WINTER WEATHER ADVISORY OVER TO A WIND CHILL
ADVISORY IN NORTHEAST IOWA.
THIS SHOT OF ARCTIC AIR APPEARS TO BE SHORT-LIVED...HOWEVER. A
SHORTWAVE SEEN OVER ALBERTA IS PROGGED BY MODELS TO DROP DOWN
THROUGH CENTRAL MN AND WI BETWEEN 06-12Z TONIGHT. THE APPROACH OF
THE SHORTWAVE HELPS TO SWING WINDS AROUND TO THE SOUTHWEST...AND
SPREAD SOME MID/HIGH CLOUDS INTO THE AREA RESULTING FROM DPVA AND
ISENTROPIC LIFT. SO AFTER SOME COOLING FROM RADIATIONAL PROCESSES IN
THE EVENING...ADVECTIVE PROCESSES WILL HELP TEMPERATURES CLIMB
THEREAFTER. GIVEN THE COLD EVENING...EXTENDED THE WIND CHILL
ADVISORY THROUGH 12Z THU FOR SOUTHEAST MN INTO SOUTHWEST AND
CENTRAL WI. EXPANDED BOTH IN TIME AND AREA THE ADVISORY TO HELP
BLEND WITH MKX AND DVN OFFICES. THE NEXT QUESTION IS IF ANY SNOW
CAN FALL WITH THE SHORTWAVE. THE 11.00Z GFS/CANADIAN/ECMWF ALL
PRODUCE A BAND OF LIGHT QPF...WITH SOUNDINGS SUGGESTING THE
FORCING IS MOSTLY CO- LOCATED WITH THE DENDRITIC GROWTH ZONE. THE
AFOREMENTIONED MODELS ALL SUGGEST A QUICK MOVING BAND...LIMITING
ACCUMULATIONS...BUT A FEW TENTHS SEEM REASONABLE. HAVE RAISED
PRECIPITATION CHANCES TOWARDS 60. NAM IS THE ONLY MODEL NOT
SHOWING ANY PRECIPITATION...BUT EVEN IT HAS INDICATIONS OF THE
FORCING.
.LONG TERM...(THURSDAY THROUGH TUESDAY)
ISSUED AT 334 AM CST WED DEC 11 2013
MAIN LONG TERM FORECAST CONCERNS ARE ON MINIMAL PRECIPITATION
CHANCES THROUGHOUT.
SOME DEAMPLIFICATION OF THE FLOW ACROSS THE NORTHERN U.S. IS PROGGED
TO OCCUR THURSDAY THROUGH FRIDAY IN RESPONSE TO A TROUGH DROPPING
DOWN THROUGH THE PACIFIC NORTHWEST. THE SWITCH TO A ZONAL FLOW
PATTERN IN THE NORTHERN STREAM APPEARS TO HAVE PLENTY OF MID/UPPER
LEVEL MOISTURE...WHICH IS GOING TO MANIFEST ITSELF IN A LOT OF
CLOUDS. PRECIPITATION CHANCES OVERALL LOOK PRETTY MINIMAL...
THOUGH...AS PLENTIFUL DRY LOW LEVEL AIR IS IN PLACE. ADDITIONALLY...
FORCING APPEARS RESTRICTED TO SOME WEAK MID LEVEL FRONTOGENESIS
STRETCHING FROM NORTHERN/CENTRAL MN INTO NORTHERN WI THU NIGHT AND
FRIDAY. THIS FORCING COULD SQUEEZE OUT SOME SNOW...BUT CONFIDENCE IS
ONLY HIGH ENOUGH FOR A 20 PERCENT CHANCE NORTH OF HIGHWAY 10.
REGARDING THAT AFOREMENTIONED FRONTOGENESIS...THIS WILL OCCUR BEHIND
A COLD FRONTAL PASSAGE PROGGED TO MOVE THROUGH THE AREA THU NIGHT.
SO AFTER A WARMER THURSDAY IN RESPONSE TO LOW LEVEL WARM
ADVECTION...TEMPERATURES HEAD BACK DOWN THU NIGHT...BUT NOT NEARLY
AS COLD AS IT HAS BEEN. DESPITE THE COLD ADVECTION...TEMPERATURES
FRIDAY SHOULD REBOUND CLOSE TO THURSDAYS HIGHS.
FOR FRIDAY NIGHT AND SATURDAY...THE FOCUS HAS BEEN ON A SHORTWAVE
TROUGH AND GENERAL SYSTEM COMING OUT OF THE CENTRAL PLAINS. THIS
SHORTWAVE TROUGH IS CURRENTLY AN UPPER LOW SITTING OFF THE FAR
SOUTHERN CALIFORNIA COAST. 11.00Z ECMWF/GFS/CANADIAN HAVE TRENDED
SLIGHTLY FARTHER SOUTHEAST WITH THIS SYSTEM...AND AS SUCH...THE
PRECIPITATION ALSO MOVED A LITTLE FARTHER AWAY. THERE STILL ARE
INDICATIONS THAT THE MID LEVEL FRONTOGENESIS SITTING OVER NORTHERN
WI ON FRIDAY WILL SLIDE SOUTH OVER THE REST OF THE AREA FRIDAY
NIGHT...POSSIBLY SQUEEZING OUT A LITTLE LIGHT SNOW.
THEREFORE...HAVE HAD TO MAINTAIN SOME 20-40 PERCENT
CHANCES...HIGHEST BETWEEN 06-12Z SATURDAY. CHANCES CONTINUE
THROUGH THE DAY SATURDAY AND INTO SATURDAY NIGHT...MORE IN
RESPONSE TO A POTENT SHORTWAVE TROUGH DROPPING DOWN FROM MANITOBA
INTO UPPER MICHIGAN.
FOR SUNDAY AND BEYOND...SUNDAY IS LOOKING CHILLY AS THE POTENT
TROUGH BRINGS DOWN A BRIEF SHOT OF ARCTIC AIR WITH IT ON ITS BACK
SIDE. 850MB TEMPS FALL TO -14 TO -20C AT 18Z SUNDAY PER 11.00Z
ECMWF...COLDEST OVER TAYLOR COUNTY. MAY GET CLOSE FOR NEEDING A WIND
CHILL ADVISORY SUNDAY MORNING. A WARM ADVECTION PATTERN THEN LOOKS
TO ENSUE FOR SUNDAY NIGHT INTO MONDAY AS YET ANOTHER DECENT
SHORTWAVE TROUGH TRACKS FROM MANITOBA INTO UPPER MICHIGAN. FOLLOWED
CONSENSUS AND INCLUDED 20 PERCENT CHANCES FOR MONDAY. TEMPERATURES
MAY REBOUND HIGHER TOO THAN CURRENTLY FORECAST...BUT GIVEN HOW FAR
OUT THIS PERIOD IS IN THE FORECAST...STAYED CLOSER TO A MODEL
CONSENSUS WITH HIGHS IN THE 15-20 RANGE.
FOR THOSE LOOKING FOR A WARM-UP...THE ECMWF CONTINUES TO HINT AT ONE
FOR THE MIDDLE TO END OF NEXT WEEK AS A DEEP TROUGH FORMS OVER THE
WESTERN U.S.. THE CFS HAS ALSO BEEN ADVERTISING ABOVE NORMAL
TEMPERATURES DURING THIS SAME TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z WEDNESDAY NIGHT)
ISSUED AT 1125 PM CST TUE DEC 10 2013
LATEST SHORT WAVE TROUGH IS MOVING THROUGH THE REGION QUICKLY LATE
THIS EVENING. LOWER VISIBILITIES AND CEILINGS REMAINING JUST SOUTH
OF FORECAST AREA BUT STILL SEEING MVFR CONDITIONS WITH LIGHT SNOW
FLYING FOR A FEW MORE HOURS. AS WAVE MOVES OUT OVERNIGHT...COLD
FRONT ON ITS HEELS WILL SCATTER CLOUDS OUT QUICKLY LEADING TO RETURN
TO VFR CONDITIONS BY DAYBREAK.
GUSTY NORTHWEST WINDS BEHIND FRONT EARLY THIS MORNING COULD KICK UP
A LITTLE BLOWING SNOW AT TIMES PRODUCING MINIMAL IMPACT TO AVIATION.
WINDS WILL SUBSIDE WEDNESDAY AFTERNOON AS SHORT TERM RIDGING BUILDS
IN AHEAD OF YET ANOTHER WAVE LATER WEDNESDAY NIGHT.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR WIZ054-
061.
WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR WIZ032>034-
041>044.
WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 6 AM CST THURSDAY
FOR WIZ053-055.
WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR WIZ017-029.
MN...WIND CHILL ADVISORY UNTIL 6 AM CST THURSDAY FOR MNZ079-086>088-
094>096.
IA...WINTER WEATHER ADVISORY UNTIL 9 AM CST THIS MORNING FOR
IAZ008>011-018-019-029-030.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...SHEA
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1045 PM CST TUE DEC 10 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND WEDNESDAY
ISSUED AT 246 PM CST TUE DEC 10 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW THE EARLIER
CLIPPER EXITING THE REGION OVER NORTHEAST LOWER MICHIGAN. PARTIAL
CLEARING HAS OCCURRED BEHIND THE SYSTEM ACROSS THE STATE...BUT LIKE
YESTERDAY...STRATO-CU KEEPS RE-DEVELOPING WITHIN THE ARCTIC AIRMASS
DUE TO STEEP LOW-LEVEL LAPSE RATES. LIGHT SNOW SHOWERS/FLURRIES ARE
NOT AS WIDESPREAD AS YESTERDAY...BUT ARE STILL SHOWING UP ON RADAR
MAINLY OVER CENTRAL AND SOUTHERN WISCONSIN. THESE LIGHT SNOW
SHOWERS/FLURRIES SHOULD AGAIN SUBSIDE AROUND SUNSET. THEN ATTENTION
TURNS TO THE VARIOUS SHORTWAVES/CLIPPERS UPSTREAM. ONE CLIPPER OVER
LAKE WINNIPEG IS ANTICIPATED TO SWING ACROSS LAKE SUPERIOR AND THE
UPPER PENINSULA TONIGHT. A MORE POTENT WAVE RESIDES OVER MONTANA
WHICH WILL ALSO MOVE ACROSS THE REGION LATE OVERNIGHT. AS A
RESULT...LIGHT SNOW POTENTIAL AND WIND CHILL HEADLINES ARE THE MAIN
FORECAST CONCERNS IN THE SHORT TERM.
TONIGHT...ANOTHER FAST MOVING CLIPPER SYSTEM WILL SLIDE QUICKLY
SOUTHEAST INTO THE WESTERN GREAT LAKES/NORTHERN MISSISSIPPI VALLEY.
AHEAD OF THE SHORTWAVE...A WEAK SURFACE CIRCULATION WILL MOVE ACROSS
IOWA AND INTO NORTHERN ILLINOIS. FORCING IS NOT NEARLY AS ROBUST AS
THE PAST CLIPPER...AND THE TRACK IS A COUPLE HUNDRED MILES FURTHER
SOUTH AS WELL. BUT SEEMS TO HAVE ENOUGH MOISTURE ON THE NORTHERN
PERIPHERY OF THE SYSTEM FOR LIGHT SNOW TO GRAZE CENTRAL AND
EAST-CENTRAL WISCONSIN COUNTIES. HAVE KEPT THE CHANCE OF SNOW IN
THE FORECAST...BUT DID DELAY THE ARRIVAL A COUPLE HOURS TO MATCH THE
LATEST TRENDS. AS THE CLIPPER PASSES BY TO THE SOUTH...SHOULD SEE A
SECONDARY SURGE OF ARCTIC AIR ARRIVE LATE TONIGHT. THEREFORE
ANTICIPATE WIND CHILL READINGS TO FALL OFF QUICKLY OVERNIGHT AS THIS
SURGE OF ARCTIC AIR SPREADS EAST. ALREADY WILL BE NEAR WIND CHILL
ADVISORY CRITERIA OVER N-C WISCONSIN FOR THE EVENING...SO WILL NOT
TAKE MUCH COLDER AIR FOR CRITERIA TO BE MET. WILL KEEP THE START
TIME AS PLANNED...THOUGH N-C WISCONSIN MAY SEE THE CRITERIA BREACHED
AN HOUR OR TWO BEFORE ISSUANCE TIME. LITTLE CHANGE TO LOW TEMPS.
WEDNESDAY...CLEARING SKIES WILL TAKE PLACE WEDNESDAY MORNING AS THE
CORE OF THE ARCTIC AIR MOVES INTO THE FORECAST AREA. DESPITE MOSTLY
CLEAR TO PARTLY CLOUDY CONDITIONS...TEMPS WILL STRUGGLE TO RISE
ABOVE 0 DEGREES OVER CENTRAL AND NORTH-CENTRAL WISCONSIN. WIND
CHILL READINGS MAY RISE ABOVE ADVISORY CRITERIA FOR A FEW HOURS
DURING THE AFTERNOON OVER NORTHEAST WISCONSIN...ONLY TO FALL BELOW
AGAIN BY THE START OF THE EVENING. WILL THEREFORE LET THE WIND
CHILL HEADLINES GO INTO THE NEXT PERIOD.
.LONG TERM...WEDNESDAY NIGHT THROUGH TUESDAY
ISSUED AT 246 PM CST TUE DEC 10 2013
CONTINUED COLD TEMPERATURES AND PERIODIC SNOW CHANCES...MOST
NOTABLY FRIDAY NIGHT INTO SATURDAY...WILL BE THE MAIN FCST
CONCERNS.
MOSTLY CLEAR SKIES WILL ALLOW TEMPS TO FALL WELL BLO ZERO WEDNESDAY
EVENING...BUT WAA AND INCREASING CLOUDS WILL PROBABLY RESULT IN
STEADY OR SLOWLY WARMING TEMPS BEFORE DAYBREAK. ENOUGH SATURATION
SHOULD OCCUR OVER OUR SW COUNTIES LATE TO ALLOW SOME LIGHT SNOW OR
FLURRIES TO DEVELOP. STEADY WEST WINDS AND VERY COLD TEMPS WILL
RESULT IN BITTER COLD WIND CHILLS...WHICH WILL LINGER INTO EARLY
THURSDAY. HAVE EXTENDED THE WIND CHILL ADVISORY UNTIL 15Z THU.
WILL EVENTUALLY NEED TO ADD THE LAKESHORE COUNTIES TO THE ADVISORY
FOR WEDS NGT...BUT THAT CAN BE DONE WITH SUBSEQUENT FCSTS.
A VERY STRONG BAROCLINIC ZONE WILL BE IN PLACE FROM THURSDAY INTO
FRIDAY. WITH WAA CONTINUING ON THURSDAY...AND THE RRQ OF AN UPPER
JET...FRONTOGENETIC FORCING AND WEAK SHORT-WAVE ENERGY AFFECTING
THE REGION THU NGT/FRI...ENOUGH FORCING SHOULD BE PRESENT TO
CONTINUE A CHANCE OF LIGHT SNOW/FLURRIES THROUGH THE PERIOD. A
MODEST MODERATION IN TEMPS WILL OCCUR LATE IN THE WORK WEEK...
BUT BACKED OFF A LITTLE ON THE PREVIOUS MAX TEMPS FOR FRIDAY.
ITS STARTING TO LOOK MORE INTERESTING LATE FRI NGT/SATURDAY
AS AN INVERTED SFC TROF MOVES THROUGH THE REGION. LOW-LEVEL
CONVERGENCE IS EXPECTED TO BE QUITE STG IN THE FOX VALLEY/LKSHR
AREAS...AND SYNOPTIC FORCING SHOULD BE PROVIDED BY H8 WAA/ISENT
LIFT AND SOME UPPER JET ENERGY. LAKE-ENHANCEMENT IS LIKELY...WITH
E-SE WINDS OFF LAKE MICHIGAN AND LK-H8 DELTA-T`S OF 14-18 C. WILL
RAISE POPS TO LIKELY OVER THE FOX VALLEY AND ESPECIALLY THE
LAKESHORE COUNTIES...AND MENTION THE POSSIBILITY OF 2-4 INCH
ACCUMS (WITH LOCAL HIGHER AMOUNTS ON THE LKSHR) IN THE HAZARDOUS
WEATHER OUTLOOK.
THE FCST IS UP IN THE AIR SATURDAY NIGHT/SUNDAY...AS SOME OF
THE MEDIUM RANGE MODELS (ESPECIALLY THE GFS) BRING AN UPPER LOW
FARTHER SOUTH (THROUGH WI) AND LINGER THE INVERTED SFC TROF OVER
THE WESTERN GREAT LAKES REGION. ALTHOUGH THE ECMWF WAS STILL
TAKING THE UPPER LOW THROUGH LAKE SUPERIOR...IT HAD SHOWN A
FARTHER SOUTH SOLN A COUPLE DAYS AGO...SO THIS BEARS WATCHING.
AT THE LEAST...IT APPEARS THAT COLD CYCLONIC NORTH FLOW WILL
BRING ANOTHER SHOT OF ARCTIC AIR INTO THE REGION BY SUDAY...AND
CAUSE LAKE-ENHANCED SNOW TO INCREASE OVER NC WI. AT WORST...
ACCUMULATING SNOW COULD CONTINUE ACROSS MUCH OF THE FORECAST
AREA SATURDAY NIGHT INTO SUNDAY MORNING. FOR NOW...HAVE JUST
INCREASED POPS OVER THE LAKE SUPERIOR SNOW BELT. THE ARCTIC
SURGE SHOULD BE BRIEF.
THE CHANCE OF LIGHT SNOW OR FLURRIES WILL CONTINUE EARLY NEXT
WEEK...AS SEVERAL S/W TROFS MOVE THROUGH THE WESTERN GREAT
LAKES...AND THE ARCTIC BAROCLINIC ZONE OSCILLATES OVER THE
REGION.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1045 PM CST TUE DEC 10 2013
ANOTHER IN A SERIES OF WEAK CLIPPER SYSTEMS WILL PASS OVER THE
SOUTH HALF THE STATE OVERNIGHT BEFORE DEPARTING SOUTHEAST
WISCONSIN WEDNESDAY MORNING. EXPECT MAINLY A PERIOD OF VFR CIGS
WITH SCATTERED MVFR CIGS DURING PASSAGE FOLLOWED BY ANOTHER SHOT
OF COLD ARCTIC AIR WITH GUSTY WEST WINDS FOR WEDNESDAY. DRIER AIR
WILL DIMINISH CLOUDS QUICKLY FROM WEST TO EAST FOR VFR CONDITIONS
FOR WEDNESDAY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 3 AM WEDNESDAY TO 9 AM CST THURSDAY FOR
WIZ013-020-021-031-037>039-045-048-049-073-074.
WIND CHILL ADVISORY UNTIL 9 AM CST THURSDAY FOR WIZ005-010>012-
018-019-030-035-036.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......TDH
AREA FORECAST DISCUSSION
NWS ALBANY NY
330 AM EST FRI DEC 13 2013
.SYNOPSIS...
AN ARCTIC FRONTAL BOUNDARY WILL GRADUALLY SLIDE ACROSS THE REGION
TODAY. IN ITS WAKE...HIGH PRESSURE WILL ATTEMPT TO BUILD OVER
THE NORTHERN HALF OF THE REGION TONIGHT. A WINTER STORM WILL TAKE
SHAPE AND IMPACT THE REGION THIS WEEKEND WITH MODERATE TO
SIGNIFICANT AMOUNTS OF SNOW.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 300 AM EST...
THE INITIAL CONCERN THIS MORNING IS THE ONGOING LAKE EFFECT
ACTIVITY DOWNWIND OF LAKE ONTARIO. KTYX DOPPLER RADAR SUGGESTS THE
INLAND EXTENT OF THE >20DBZ WAS ACROSS NORTH CENTRAL HERKIMER
COUNTY AROUND 60 MILES INLAND FROM THE LAKE. THIS IS IN EXCELLENT
AGREEMENT WITH THE LOCALLY DEVELOPED CSTAR RESEARCH OF LAKE EFFECT
INLAND EXTENT PROGRAM WHICH KEEPS THIS BAND AROUND THAT 60 MILE
INLAND PENETRATION THROUGH THE REMAINDER OF THIS EARLY FRIDAY
MORNING. AFTER SUNRISE...THE ARCTIC FRONTAL BOUNDARY IS EXPECTED
TO SLIDE TOWARD THE I90 CORRIDOR WHICH WILL SHIFT THE BOUNDARY
LAYER WIND TOWARD A WEST-NORTHWEST THEN NORTHWEST WHICH WILL TAKE
THIS BAND SOUTHWARD. MAIN QUESTION WILL BE HOW MUCH THIS FRONT
WILL INTERACT WITH THE MOISTURE AND TRANSPORT IT DOWNSTREAM INTO
THE MOHAWK VALLEY AND THE CAPITAL REGION. LOCALLY DEVELOP HIRESWRF
AND HRRR REFLECTIVITY FORECASTS SUGGEST A FEW SNOW SHOWERS AND
SQUALLS MAY MAKE IT INTO THESE REGIONS AS WE WILL PLACE A LITTLE
HIGHER POPS THROUGH THE MORNING HOURS. AS THE FLOW CONTINUES TO
BACK IN THE WAKE OF THE FROPA...THIS BAND WILL WEAKEN AS FLOW
TRAJECTORY BECOMES LESS THAN FAVORABLE FOR OUR REGION AND LOWERING
SUBSIDENCE INVERSION AS SURFACE HIGH BUILDS NORTH OF THE GREAT
LAKES REGION AND EXTENDS ITS INFLUENCE OVER LAKE ONTARIO.
CLOUDS WILL BE A CHALLENGE TODAY AS 1000-850MB RH VALUES FROM THE
LATEST RUC13 CONTINUE TO SUPPORT RATHER HIGH VALUES FOR THE
SOUTHERN 2/3RDS OF THE CWA. HOWEVER...THE LOW LEVEL AGEOSTROPHIC
FLOW DOES INCREASE A BIT WHICH SHOULD ASSIST WITH THE DRIER AIR
AND EVENTUAL MECHANICAL MIXING FOR SOME BREAKS TO OCCUR INTO THE
CAPITAL REGION LATER THIS AFTERNOON. THE COLD ADVECTION TODAY
ALONG WITH THE CLOUD COVER AND A VERY LOW SUN ANGLE SHOULD KEEP
AFTERNOON HIGHS RATHER CHILLY INTO THE TEENS FOR THE TERRAIN AND
20S ELSEWHERE AS H850 TEMPS DROP BACK WELL INTO THE NEGATIVE TEENS
AND AROUND -20C FOR THE DACKS.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
...WINTER STORM WATCH FOR THE ENTIRE REGION...
EXTENSIVE COLLABORATION WITH NEIGHBORING WFOS AND WPC THIS MORNING
AS 00Z GUIDANCE IS SLOWLY COMING TO AN AGREEMENT WITH A
SIGNIFICANT IMPACT FROM THIS DEVELOPING WINTER STORM. THIS STORM
IS MORE OF A MILLER TYPE `B` AS REDEVELOPMENT WILL COMMENCE FROM
THE OHIO VALLEY SYSTEM TO THE MID ATLANTIC REGION.
THE MAIN PLAYER WITH THIS UPCOMING EVENT WAS SITUATED OVER THE
FOUR CORNERS REGION PER THE H2O VAPOR LOOP ANALYSIS.
MEANWHILE...PACIFIC MOISTURE WAS ADVANCING AHEAD OF THIS SYSTEM
ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY. A
POTENT UPPER JET WAS DIVING INTO THE NORTHERN TIER OF THE CONUS AS
THESE SYSTEMS WILL ATTEMPT TO PHASE OVER THE MID ATLANTIC INTO THE
NORTHEAST CORRIDOR ON SATURDAY.
THE AFOREMENTIONED ARCTIC FRONTAL BOUNDARY WILL BECOME QUASI-
STATIONARY ALONG OR JUST SOUTH OF THE NY STATE LINE TONIGHT WITH
BROAD ISENTROPIC LIFT EVOLVING OVER WESTERN AND CENTRAL NY. THIS
WILL SPELL OUT LIGHT SNOW DEVELOPING FROM WEST TO EAST AND COULD
EXTEND AS FAR EAST AS THE CATSKILLS OVERNIGHT. FOR THE REMAINDER
OF THE REGION...EXPECTING A MAINLY DRY OVERNIGHT AS THAT ARCTIC
DRY AIRMASS ADVECTS SOUTHWARD THROUGH THE HUDSON RIVER VALLEY.
OVERNIGHT LOWS WILL DROP WELL BELOW ZERO ACROSS THE DACKS WHERE
THE BETTER CHANCE FOR CLEARING SKIES AND TEENS ELSEWHERE AS THE
H850 TEMPS DROP TO BELOW -20C ACROSS THE NORTH AND NEGATIVE MID
TEENS ELSEWHERE.
IN FACT...THIS AGEOSTROPIC LOW LEVEL COMPONENT WHILE WEAK IN
MAGNITUDE IS RATHER PERSISTENT THROUGH THE DAY SATURDAY INTO
SATURDAY EVENING. THIS WILL KEEP THE PRECIP ALL SNOW AS ISENTROPIC
LIFT INCREASES AND LIGHT SNOW SPREADS ACROSS MOST THE REGION FROM
SOUTH TO NORTH THROUGH THE DAY. ACCUMULATIONS DURING SATURDAY WILL
LIKELY RANGE FROM AROUND 1 INCH ACROSS THE NORTHERN PORTIONS OF
THE REGION WITH AROUND 3 INCHES FOR THE SOUTH AND SOUTHWEST
PORTIONS OF THE REGION. HIGH TEMPERATURES WILL STRUGGLE TO GET OUT
OF THE TEENS.
SATURDAY NIGHT...THIS WILL BE THE MAIN EVENT FOR THE REGION AS
INCREASING LOW LEVEL SOUTH-SOUTHEAST JET GREATER THAN 50KTS
DEVELOPS AS SECONDARY DEVELOPMENT OF THE COASTAL LOW TAKES SHAPE.
THERE WILL BE AN ENHANCED REGION OF 2-D FGEN FORCING PER THE NCEP
MODEL SUITE ACROSS THE SOUTHERN AREAS /MAINLY JUST SOUTH OF THE
CAPITAL REGION/ WHERE SNOWFALL RATES COULD BE ENHANCED. THE
COMBINATION OF THIS SNOWFALL BAND AND THOSE WINDS COULD
POTENTIALLY BRING NEAR BLIZZARD CONDITIONS FOR THE HIGHER TERRAIN
FOR A PERIOD OF TIME. THE REMAINDER THE REGION...SNOW WILL BE
ONGOING WITH LATEST PLUME DIAGRAMS POINTING TOWARD 0.90" H2O
EQUIVALENT FROM THE GEFS/SREF. CROSS SECTIONS REVEAL THE BEST LIFT
FOR THE MOST OF THE REGION WILL OCCUR JUST BELOW THE BEST
DENDRITIC ICE GROWTH WHILE CLOSER TO THE 2D FGEN BANDS THAT WE
EFFECTIVELY TAP INTO THAT DENDRITIC ICE GROWTH. HERE...COULD SEE
SNOWFALL RATES APPROACHING UP TO 2 INCHES PER HOUR. THE ONLY SMALL
ISSUE TO THESE SNOWFALL RATES WILL BE THE DEGREE OF WARM AIR
ADVECTING NORTHWARD. SEEMS SOUTHERN PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES COULD SEE A PERIOD OF SLEET/FZRA PER TOP-DOWN
THERMAL APPROACH FROM AN ENSEMBLE TREND OF THE NCEP MODELS.
SUNDAY...THE MAIN STORM CENTER NOW REFORMS AND INTENSIFIES OVER
THE GULF OF MAINE SUNDAY MORNING. THERE COULD BE A PERIOD OF THE
MOHAWK VALLEY CONVERGENCE PER CSTAR RESEARCH WHICH WILL NEED TO BE
MONITORED. OTHERWISE...SNOW WILL GRADUALLY DIMINISH IN COVERAGE
AND INTENSITY THROUGH THE DAY AS WE TRANSITION TO LIGHT SNOW
SHOWERS AND UPSLOPE FAVORED LOCATIONS FOR SOME ADDITIONAL SNOW
ACCUMULATIONS.
AT THE END OF THIS EVENT...COULD SEE VALUES OF 6-12 INCHES ACROSS
THE REGION HENCE THE WINTER STORM WATCH IN EFFECT FOR THE ENTIRE
REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE DEPARTING WINTER STORM WILL CONTINUE TO LIFT NORTHEAST TOWARDS
ATLANTIC CANADA...WITH COLD CYCLONIC FLOW IN PLACE OVER THE
NORTHEASTERN US IN ITS WAKE. SOME LINGERING LAKE ENHANCED SNOW
SHOWERS WILL AFFECT THE WESTERN ADIRONDACKS AND WESTERN MOHAWK
VALLEY ON SUNDAY NIGHT WITH VERY COLD TEMPS...THANKS TO THE FRESH
SNOW COVER AND DIMINISHING WINDS. MOST AREAS LOOK TO DROP INTO THE
SINGLE DIGITS...WITH BELOW ZERO READINGS POSSIBLE OVER THE HIGH
TERRAIN...ESP IN THE ADIRONDACKS.
HIGH PRESSURE WILL PASS OVER THE REGION ON MONDAY...ALLOWING FOR DRY
WEATHER WITH BELOW NORMAL TEMPS. HIGHS WILL ONLY REACH THE TEENS TO
LOW 20S WITH PARTIAL SUNSHINE.
CLOUDS WILL QUICKLY INCREASE FOR MONDAY NIGHT AS A CLIPPER SYSTEM
DIVES FROM SOUTHERN CANADA TOWARDS THE GREAT LAKES. THERE IS GOOD
MODEL AGREEMENT THAT THIS SYSTEM WILL SLIDE ACROSS THE NORTHEAST FOR
LATE MONDAY NIGHT INTO TUESDAY. AS A RESULT...A SEVERAL HOUR PERIOD
OF LIGHT SNOW LOOKS TO MOVE ACROSS THE REGION. MOISTURE WILL BE
LIMITED...AND ANY SNOWFALL LOOKS TO BE LESS THAN ADVISORY LEVEL
AMOUNTS. TEMPS WILL CONTINUE TO BE VERY COLD...WITH SINGLE DIGITS
MONDAY NIGHT...AND MAINLY 20S ON TUESDAY.
BEHIND THIS SYSTEM...ANOTHER ROUND OF LAKE EFFECT SNOW LOOKS TO
IMPACT THE WESTERN ADIRONDACKS FOR TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. MEANWHILE...DRY WEATHER BUT BELOW NORMAL TEMPS WILL CONTINUE
ACROSS THE REMAINDER OF THE FORECAST AREA. MIN TEMPS TUESDAY NIGHT
WILL BE IN THE TEENS TO NEAR 20...WITH 20S TO LOW 30S DURING THE DAY
WEDNESDAY...AND TEENS AGAIN ON WED NIGHT.
THE LAKE EFFECT SHOULD SHUT OFF SOMETIME THURSDAY...AS A LARGE AREA
OF HIGH PRESSURE PASSES OVER THE AREA. SOME MODERATION IN TEMPS
WILL START TO OCCUR...AS A TROUGH BEGINS TO GET CARVED OUT ACROSS
THE WESTERN US AND RIDGING DEVELOPS ACROSS THE SOUTHEASTERN US. THIS
WILL PUT OUR REGION IN A SW FLOW ALOFT. TEMPS ON THURSDAY MAY
FINALLY REACH THE FREEZING MARK IN THE CAPITAL REGION...ALTHOUGH
HIGH TERRAIN AREAS WILL STILL BE IN THE 20S. THE WARMING TREND
APPEARS TO CONTINUE RIGHT INTO THE UPCOMING WEEKEND.
&&
.AVIATION /08Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TERMINALS AND THIS WILL CONTINUE
THROUGH THE REMAINDER OF THE OVERNIGHT HOURS WITH JUST SCT-BKN
STRATOCU CLOUDS AROUND 3500-4000 FT. DURING THE LATE MORNING TO
EARLY AFTN HOURS...AN ARCTIC FRONTAL BOUNDARY...AIDED BY SOME
MOISTURE OFF LAKE ONTARIO...WILL PASS THROUGH THE REGION. THIS MAY
ALLOW FOR SOME SNOW SHOWERS ACROSS THE REGION. THE BEST CHANCE WILL
BE FOR KALB/KPSF...AS THE SNOW SHOWERS MAY PASS DOWN THE MOHAWK
VALLEY AND TOWARDS THE CAPITAL REGION/BERKSHIRES. WE HAVE INCLUDED A
PROB30 TO INCLUDE THE POTENTIAL FOR A BRIEF IFR SNOW SHOWER DURING
THE LATE MORNING/EARLY AFTN. OUTSIDE OF SNOW SHOWERS...CIGS WILL BE
BKN AROUND 4 KFT DURING THE DAY FRIDAY. CLOUDS SHOULD START TO CLEAR
FOR FOR FRIDAY EVENING/FRIDAY NIGHT.
WINDS WILL BE S-SW AHEAD OF THE BOUNDARY THROUGH THE REMAINDER OF
THE OVERNIGHT HOURS AROUND 5-10 KTS. DURING THE DAY FRIDAY...WINDS
WILL BECOME W-NW AT 10-15 KTS WITH A FEW HIGHER GUSTS...ESP AT
KALB/KPSF. WINDS WILL DIMINISH ON FRIDAY EVENING WITH THE LOSS OF
DAYTIME HEATING.
OUTLOOK...
FRIDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SATURDAY THROUGH SUNDAY: HIGH OPERATIONAL IMPACT. SN.
MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF -SHSN.
TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED THROUGH EARLY NEXT WEEK.
MAINLY SNOW WILL FALL THIS WEEKEND AND TEMPERATURES WILL BE WELL
BELOW NORMAL AND ICE WILL CONTINUE TO FORM ON AREA RIVERS...STREAMS
AND PARTICULARLY LAKES THROUGH EARLY NEXT WEEK.
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...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR CTZ001-013.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ033-038.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ032.
MA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR MAZ001-025.
VT...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS TAMPA BAY RUSKIN FL
300 AM EST FRI DEC 13 2013
.SYNOPSIS...
08Z WATER VAPOR AND H4 RAP ANALYSIS SHOWS A CONVERGENT UPPER LEVEL
PATTERN OVER THE EASTERN HALF OF THE NATION BETWEEN THE NORTHERN AND
SOUTHERN STREAM FLOW. TROUGHING THAT PAST THROUGH THE SE CONUS THE
PAST 24 HOURS AND HELPED FINALLY EXIT THE OLD COLD FRONT TO OUR
SOUTH IS NOW WELL OFF TO THE EAST OF THE REGION. THIS FEATURE ALSO
SIGNIFICANTLY DRIED OUT OUR COLUMN OVERHEAD WITH IT ASSOCIATED POST
PASSAGE SUBSIDENCE. TO SHOW THE EXTENT OF DRYING THAT WE SAW DURING
THURSDAY...THE 12/12Z KTBW SOUNDING PROFILE HAD A PW OF 1.4" WHILE
THE 13/00Z PROFILE WAS DOWN TO AROUND 0.6". ELSEWHERE...A CLOSED LOW
FEATURE OVER THE 4-CORNERS REGION IS BEGINNING TO OPEN UP AND BECOME
PROGRESSIVE TO THE EAST THIS MORNING. ALREADY BEGINNING TO SEE UPPER
LEVEL SOUTHERN STREAM MOISTURE STREAM EASTWARD AHEAD OF THIS FEATURE
ALONG THE NORTHERN GULF COAST...AND SOME OF THIS CIRRUS WILL BEGIN
TO INVADE OUR SKIES THIS MORNING.
AT THE SURFACE...FLORIDA PENINSULA RESIDES BETWEEN THE OLD DECAYING
FRONTAL BOUNDARY TO OUR SOUTH...AND 1030MB HIGH PRESSURE CENTERED
NEAR THE TN VALLEY. THE GRADIENT BETWEEN THESE 2 FEATURES IS
PROVIDING A GENERAL E/NE FLOW THIS MORNING. THE BOUNDARY LAYER IS
QUITE DRY EARLY THIS MORNING WITH DEWPOINTS IN THE 30S AND
40S...HOWEVER...WITH THE EASTERLY FLOW OFF THE ATLANTIC AND THE LOSS
OF COOL/DRY AIR ADVECTION...THESE LOW LEVEL MOISTURE LEVELS WILL
BEGIN TO CREEP BACK UP BY TONIGHT. TEMPERATURES ARE ALSO BECOMING
QUITE COOL THIS MORNING...ESPECIALLY COMPARED TO THE PAST WEEK WE
ALL EXPERIENCED. IN CLOSEST PROXIMITY TO THE HIGH AND IN A BETTER
DRAINAGE PATTERN OVER THE FAR NORTHERN NATURE COAST...THE BOUNDARY
LAYER IS HAVING A EASIER TIME DE-COUPLING AND MORE EFFICIENT
RADIATIONAL COOLING IS TAKING PLACE. SEVERAL STATIONS NORTH OF
CRYSTAL RIVER ARE ALREADY IN THE LOWER/MID 30S AND WITH THESE TEMPS
"CRASHING THROUGH THE DEWPOINTS"...ITS A GOOD BET THAT WE WILL SEE
SOME PATCHY FROST BEFORE SUNRISE FOR PARTS OF LEVY COUNTY...AND
INLAND NORTHERN CITRUS COUNTY. ELSEWHERE...ALTHOUGH IT WILL BE A
COOL START TO THE DAY...NO FROST OR FREEZE CONCERNS ARE EXPECTED.
&&
.SHORT TERM (TODAY THROUGH SUNDAY)...
TODAY...A FAIR WEATHER AND GENERALLY DRY DAY ON TAP TO END OUT THE
WORK WEEK AFTER THE COOL START TO THE MORNING. ZONAL FLOW ALOFT WILL
REMAIN IN PLACE THROUGH THE EVENING HOURS WHILE THE SURFACE HIGH
SHIFTS EASTWARD OFF THE CAROLINA COAST. THE FAIRLY DRY COLUMN AND
LACK OF ANY SYNOPTIC FORCING SUGGEST VERY LOW RAIN CHANCES FOR THE
REGION. ONLY EXCEPTION THAT ONE COULD SEE IS IN FAR EASTERN
POLK/HIGHLANDS COUNTY WHERE THE EASTERLY ONSHORE FLOW ALONG THE FL
EAST COAST COULD BE ENOUGH TO FORCE A FEW SHALLOW SPEED CONVERGENCE
SHOWERS/SPRINKLES. LOCAL HI-RES MODEL RUNS ARE SHOWING THE POTENTIAL
FOR THESE SHOWERS WITH MOST OF THE ACTIVITY EVAPORATING BEFORE
REACHING OUR ZONES. CAN NOT RULE OUT AN ISOLATED SPRINKLE FOR THESE
AREAS DURING THE AFTERNOON HOURS...BUT NO MEASURABLE RAINFALL IS
EXPECTED. OTHERWISE...SOME HIGH LEVEL CIRRUS AT TIMES AND A
DEVELOPING CUMULUS FIELD ASSOCIATED WITH THE INCREASING LOW LEVEL
ATLANTIC MOISTURE WILL GIVE US A MIX OF SUN AND CLOUDS BY THE
AFTERNOON. TEMPERATURES CLIMB TO THE LOWER 70S NORTH...MIDDLE 70S
ALONG THE I-4 CORRIDOR...AND MID/UPPER 70S DOWN TOWARD FORT MYERS.
TONIGHT...A NOTICEABLY WARMER OVERNIGHT PERIOD IN STORE WITH MANY
SPOTS SEEING LOWS 10+ DEGREES WARMER THAN FRIDAY MORNING. SHORTWAVE
IMPULSE WILL EJECT EASTWARD FROM THE SOUTHERN PLAINS TOWARD THE TN
VALLEY WITH AN ASSOCIATED WEAK SURFACE REFLECTION TRACKING ACROSS
THE LOWER MS VALLEY. A COLD FRONT WILL THEN TRAIL BACK FROM THIS
FEATURE INTO THE WESTERN GULF OF MEXICO. ANY SYNOPTIC FORCING OF
INFLUENCE WILL BE WELL TO OUR NORTH AND NORTHWEST AND THE UPPER JET
IS UNFAVORABLE TO AID IN LARGE SCALE LIFT. NO HEIGHT FALLS ARE
SUGGESTED BY ANY GUIDANCE MEMBER...AND GFS ENSEMBLES ARE ALL TIGHTLY
CLUSTERED FOR SATURDAY MORNING. THEREFORE...FEEL CONFIDENT IN A
RAIN-FREE FORECAST FOR ALL ZONES.
SATURDAY...
IT LOOKS LIKE A PATTERN THAT WILL PROVIDE A VERY DIFFERENT FORECAST
FROM NORTH TO SOUTH ACROSS THE FORECAST AREA BY SATURDAY NIGHT. FOR
THE DAYLIGHT HOURS ON SATURDAY THOUGH...LOOKING AT A MAINLY RAIN
FREE FORECAST. INITIAL SHORTWAVE WILL QUICKLY PIVOT UP THE SPINE OF
THE APPALACHIANS...BUT BE FOLLOWED BY YET ANOTHER IMPULSE EJECTING
EASTWARD IN ITS WAKE FROM THE SOUTHERN PLAINS. THE LARGE SCALE FLOW
BETWEEN THESE TWO SHORTWAVE WILL BE NEARLY PARALLEL TO THE FRONT
ALIGNED FROM THE NORTH-CENTRAL GULF COAST TO AL/GA. THIS PARALLEL
FLOW WILL ONLY ALLOW FOR A LIMITED AMOUNT OF EASTWARD PROGRESSION
DURING THE DAY...AND WE WILL BE WAITING TILL THE VERY LATE
DAY/EVENING HOURS FOR THE NEXT IMPULSE TO FINALLY PUSH THE SYSTEM
ENOUGH TO REALLY INFLUENCE ANY OF OUR ZONES. WILL BRING IN A CHANCE
FOR SHOWERS TO CITRUS/LEVY COUNTY AND THE ADJACENT MARINE ZONES
DURING THE LATE AFTERNOON...BUT FEEL MOST OF THE CONVECTIVE ACTIVITY
WILL HOLD OFF UNTIL ALMOST DARK. SO FOR THE MAJORITY OF THE DAY WILL
SEE INCREASING CLOUDS NORTH AND A MIX OF SUN AND CLOUDS SOUTH.
PRE-FRONTAL THERMAL RIDGE AND DECENT DIURNAL MIXING WILL RESULT IN A
WARM SATURDAY WITH MID 70S TO NEAR 80 NORTH AND INTO THE LOWER/MID
80S FROM I-4 CORRIDOR SOUTHWARD. LOW LEVEL FLOW WILL VEER ONSHORE
DURING THE AFTERNOON AND THIS MAY KNOCK THE TEMPS AT THE BEACHES
BACK INTO THE 70S OFF THE RELATIVELY COOLER SHELF WATERS.
SATURDAY NIGHT...THE FRONT ALIGNS JUST TO OUR NORTHWEST WITH THE
APPROACHING TROUGH PROVIDING A ZONE OF DEEP LAYER QG-FORCING AND
INCREASING FAVORABLE UPPER JET DYNAMICS TO SUPPORT RAINFALL. THIS
SETUP IS BEST TO THE NORTH OF TAMPA BAY...AND DECREASES RAPIDLY FROM
THE I-4 CORRIDOR SOUTHWARD. AT THIS POINT...THE EXCELLENT AGREEMENT
OF THE ENSEMBLE GUIDANCE MAKES THIS FORECAST OF HIGHER CONFIDENCE
THAN USUAL. WILL GO WITH LIKELY POPS FOR THE NORTHERN NATURE COAST
ZONES...DECREASING TO CHANCE POPS THROUGH THE I-4 CORRIDOR AND THEN
DECREASING RAIN CHANCES TO 10% OR LESS DOWN TOWARD CHARLOTTE/LEE
COUNTIES. AS OF NOW...THE SEVERE THREAT FOR THE NATURE COAST LOOKS
MARGINAL AT BEST. A FEW ISOLATED WIND GUST CAN NOT BE RULED OUT...
BUT INSTABILITY IS NOT IMPRESSIVE AND NEITHER IS THE LOW LEVEL JET.
SUNDAY...RAPID CYCLOGENESIS IS PROGGED TO TAKE PLACE LATE SATURDAY
NIGHT AND SUNDAY MORNING OVER MID-ATLANTIC/NEW ENGLAND COAST
BAROCLINIC ZONE. AS THIS OCCURS...WOULD ANTICIPATE THE MAIN ENERGY
TO TRANSLATE AWAY FROM OUR REGION WITH THE SURFACE FRONT BECOME
INCREASINGLY STRETCHED WITH TIME. THEREFORE...IT MAY BE DIFFICULT TO
SUPPORT ANY ORGANIZED BANDS OF CONVECTION ON SUNDAY AS THE FRONT
SLOWLY SAGS THROUGH THE REGION. BEST FORECAST AT THIS TIME WOULD BE
FOR A MOSTLY CLOUDY DAY WITH SCATTERED SHOWER COVERAGE DECREASING
THE LATER INTO THE DAY WE GO.
&&
.LONG TERM (SUNDAY NIGHT THROUGH NEXT THURSDAY)...
A COLD FRONT WILL BE MOVING THROUGH THE AREA TO BEGIN THE PERIOD.
THE FRONT WILL BRING WITH IT A LOW CHANCE FOR SHOWERS...GENERALLY
20-30 PERCENT ACROSS THE AREA. THIS FRONT WILL GRADUALLY CLEAR THE
AREA BY MONDAY AFTERNOON WITH COOLER AND DRIER HIGH PRESSURE FROM
THE NORTHERN GULF REGION BUILDING INTO THE AREA BEHIND THE FRONT.
THIS HIGH PRESSURE CENTER WILL SLOWLY SHIFT TO THE EAST ACROSS THE
SOUTHEASTERN STATES THROUGH WEDNESDAY WITH NEAR ZONAL FLOW
ALOFT...THEN SHIFT ENE TO OVER THE WEST ATLANTIC AND EASTERN US
THROUGH THURSDAY. MODELS ARE IN GOOD AGREEMENT THROUGH WEDNESDAY
ACROSS THE REGION WITH THE RIDGING REMAINING IN PLACE ACROSS THE
AREA AND WINDS SHIFTING FROM THE NORTH TO THE EAST THROUGH THE WEEK
ALLOWING FOR A GRADUAL MODERATION IN TEMPS AND MOISTURE.
TEMPERATURES WILL BEGIN BELOW NORMAL FOR SUNDAY NIGHT THROUGH MONDAY
NIGHT...THEN NEAR NORMAL TUESDAY...AND RISING ABOVE NORMAL THROUGH
THE REST OF THE PERIOD.
&&
.AVIATION...
VFR CONDITIONS ARE EXPECTED THROUGH THE PERIOD WITH NE FLOW BECOMING
MORE EASTERLY IN THE LATE MORNING/EARLY AFTERNOON AND INCREASING TO
10-12KTS.
&&
.MARINE...
WINDS OVER THE EASTERN GULF OF MEXICO ARE BEGINNING TO SUBSIDE EARLY
THIS MORNING AND WILL CANCEL THE REMAINING SMALL CRAFT ADVISORIES
WITH THE 430AM MARINE FORECAST ISSUANCE. CAUTIONARY LEVEL WINDS AND
SEAS WILL STILL BE AROUND FOR PART OF THE MORNING AND THEN SUBSIDE
BELOW HEADLINE CRITERIA FOR THE AFTERNOON. ANOTHER BRIEF ROUND OF
CAUTIONARY LEVEL WINDS IS POSSIBLE FRIDAY NIGHT WITH WINDS AGAIN
SUBSIDING BELOW HEADLINE CRITERIA FOR SATURDAY. A COLD FRONT WILL
SLOWLY SAG THROUGH THE FORECAST WATERS LATE SATURDAY NIGHT AND
SUNDAY WITH A WIND SHIFT TO THE NORTHWEST AND NORTH IN ITS WAKE. A
ROUND OF SHOWERS AND STORM WILL ACCOMPANY THIS FRONT LATER SATURDAY
INTO SUNDAY MORNING WITH THE BEST CHANCES FOR STORMS TO THE NORTH OF
TARPON SPRINGS.
&&
.FIRE WEATHER...
HIGH PRESSURE TO OUR NORTH WILL SHIFT OFF THE CAROLINA COAST BY
TONIGHT. THE NEXT SYSTEM TO EFFECT OUR REGION WILL APPROACH FROM THE
WEST ON SATURDAY GIVING GOOD RAIN CHANCES SATURDAY NIGHT AND SUNDAY
MORNING TO AREAS NORTH OF TAMPA BAY. EASTERLY FLOW WILL BEGIN TO
DELIVER INCREASINGLY LOW LEVEL MOISTURE OFF THE ATLANTIC TODAY AND
SHOULD PREVENT ANY CRITICALLY LOW LEVELS OF RELATIVE HUMIDITY. A
FURTHER INCREASE IN LOW LEVEL MOISTURE BY SATURDAY WILL KEEP
RELATIVE HUMIDITY VALUES WELL ABOVE CRITICAL LEVELS. AREAS OF FOG
ARE ANTICIPATED TO DEVELOP AFTER MIDNIGHT FRIDAY NIGHT INTO EARLY
SATURDAY MORNING...ALTHOUGH A WIDESPREAD DENSE FOG EVENT DOES NOT
APPEAR LIKELY.
&&
.PRELIMINARY POINT TEMPS/POPS...
TPA 76 63 79 69 / 0 0 10 40
FMY 80 64 83 68 / 10 0 0 10
GIF 75 59 82 66 / 10 10 10 40
SRQ 78 62 79 69 / 0 0 10 30
BKV 74 57 82 67 / 0 0 20 50
SPG 74 65 79 69 / 0 0 10 40
&&
.TBW WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GULF WATERS...NONE.
&&
$$
SYNOPSIS/SHORT TERM/MARINE/FIRE WX...MROCZKA
LONG TERM/AVIATION...COLSON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1244 AM EST FRI DEC 13 2013
.SYNOPSIS...
ISSUED AT 1244 AM EST FRI DEC 13 2013
HIGH PRESSURE WILL BE OVER THE REGION TONIGHT BUT TEMPERATURES
WILL NOT BE AS COLD AS LAST NIGHT. LOWS WILL STILL DROP INTO THE
LOWER AND MIDDLE TEENS...WITH A FEW SINGLE DIGITS POSSIBLE IN
RURAL AREAS. CLOUDS WILL INCREASE FRIDAY AHEAD OF A STRONG LOW
PRESSURE SYSTEM WHICH WILL BRING ACCUMULATING SNOW TO THE REGION
FRIDAY NIGHT AND SATURDAY. CURRENT INDICATIONS ARE THAT
ACCUMULATIONS BETWEEN 2 AND 6 INCHES WILL BE LIKELY.
&&
.UPDATE...
ISSUED AT 844 PM EST THU DEC 12 2013
UPDATED THIS EVE TO ISSUE A WINTER WEATHER ADVISORY FOR TOMORROW
NIGHT AND SATURDAY. NO SGFNT CHANGES TO GRIDS IN THIS TIMEFRAME.
18Z MODEL RUNS IN DECENT AGREEMENT WITH GOOD RUN-RUN CONTINUITY ON
UPR LOW OPENING UP OVER SWRN U.S. THIS EVE TRACKING NE INTO THE
LWR OH VALLEY BY SATURDAY MORNING. SUB-TROPICAL PLUME ALREADY S-SW
OF THE CIRCULATION IS EXPECTED TO BE DRAWN NORTHWARD OVER THE COLD
AIRMASS IN PLACE OVER THE MIDWEST RESULTING IN WIDESPREAD OVER-
RUNNING SNOW MOVG INTO OUR AREA FRIDAY NIGHT AS THE LOW
APPROACHES... FOLLOWED BY DEFORMATION ZONE SNOWS DURING THE DAY
SATURDAY AS THE VORT MAX MOVES UP THE OH VALLEY. GIVEN THE SYSTEM
IS STILL EXPECTED TO BE IN A WKNG TREND WITH NO CLOSING OFF MID
LEVEL LOW... EXPECT SNOWFALL ACCUMS TO REMAIN BLO WARNING
CRITERIA... BUT WITH DEEP MOISTURE/LIFT THROUGH THE DGZ FCST FOR A
SUBSTANTIAL PERIOD... SGFNT SNOW AMOUNTS SHOULD OCCUR OVER MOST IF
NOT THE ENTIRE AREA FRIDAY NIGHT AND SATURDAY. WITH START OF THE
EVENT NOW APPROX 24HRS OUT AND CONFIDENCE FAIRLY HIGH... FELT
HEADLINE WARRANTED ATTM.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 323 PM EST THU DEC 12 2013
FEW CONCERNS THROUGH THE SHORT TERM PERIOD AS SIGNIFICANT WEATHER
AHEAD OF NEXT SYSTEM WILL HOLD OFF UNTIL FRIDAY NIGHT.
SATELLITE SHOWING MID AND HIGH CLOUDS EXITING SOUTHERN AREAS THIS
AFTERNOON WHILE THERMAL TROUGH SAGGING ACROSS LAKE MICHIGAN WAS
AIDING IN STRATOCU DEVELOPMENT ACROSS BERRIEN AND CASS COUNTIES IN
MICHIGAN. THESE LOW CLOUDS AND ANY LAKE EFFECT SNOW SHOWERS WILL BE
MAIN CHALLENGE TONIGHT. SYNOPTIC SCALE THERMAL TROUGH ALREADY MOVING
EAST BUT LAKE INDUCED TROUGHINESS AND THERMAL DISPARITY PROGGED TO
ONLY SLOWLY WARM OVERNIGHT. SATELLITE ALREADY SHOWING LAKE CLOUDS
INTO NORTHERN BERRIEN COUNTY DESPITE WARM AIR ADVECTION. HIRES
GUIDANCE SUGGEST TRAJECTORIES AND WEAK LAKE AGGREGATE TROUGH MAY
ALLOW CLOUDS TO STREAM ACROSS MICHIGAN COUNTIES THIS EVENING AND
INTO OVERNIGHT HOURS. PREVIOUS SKY COVER GRIDS HAD THIS TREND
HANDLED WELL AND GENERALLY STAYED WITH SIMILAR IDEA. LIGHT SNOW
SHOWERS ALREADY NEAR OR INTO EXTREME NORTHERN TIP OF BERRIEN COUNTY
SO WILL CARRY SCT FLURRIES OR LIGHT SNOW SHOWERS THROUGH THE EVENING
UNTIL WARMER AIR ARRIVES AND FLOW WEAKENS WHICH COULD LEAD TO WEAK
MESOLOW FORMATION OVER BOWL REGION OF LAKE. LITTLE OR NO
ACCUMULATION EXPECTED GIVEN SHALLOW MOISTURE DEPTH IN OUR AREA.
OTHERWISE EXPECT MOSTLY CLEAR SKIES TO START THE EVENING WITH SOME
MID AND HIGH CLOUDS INCREASING LATE.
NAM MODEL SOUNDINGS QUITE BULLISH ON LOW LEVEL MOISTURE AND STRATUS
DEVELOPMENT FRIDAY MORNING. NAM12 HAS BEEN RATHER
AGGRESSIVE WITH THIS IDEA THIS WINTER WITH SEVERAL INSTANCES SHOWING
THIS WITH LITTLE TO NO DEVELOPMENT. LATEST HRRR GIVES SOME CREDENCE
TO THIS SOLUTION IN THE NORTH NEAR WEAK SURFACE BOUNDARY WHERE WINDS
BECOME LIGHT. HAVE SLOWLY INCREASED CLOUDS ACROSS THE NORTH
AND NORTHWEST WITH POTENTIAL FOR SOME MID AND HIGH CLOUDS AS WELL.
THIS SHOULD KEEP TEMPS FROM FALLING TOO MUCH OVERNIGHT WITH WARM AIR
ADVECTION WELL UNDERWAY. LOOKING FOR LOWS IN THE 10 TO 15 DEGREE
RANGE LATE EVENING WITH STEADY OR EVEN SLOWLY RISING TEMPS LATE WITH
ANY CLOUD COVER DEVELOPMENT.
COL AREA ASSOCIATED WITH WEAK BOUNDARY WILL LIE ACROSS NW FORECAST
AREA FRIDAY WITH GENERALLY LIGHT WINDS. CLOUD COVER REMAINS TRICKY
DEPENDING ON HOW MUCH SATURATION OCCURS NEAR BOUNDARY WITH INVERSION
ALOFT COURTESY OF WARM AIR ADVECTION. HIGHS WILL REACH MID TO UPPER
20S MOST AREAS WITH LOW 30S POSSIBLE FAR SOUTHWEST AHEAD OF NEXT
STRONG SHORT WAVE. BULK OF PCPN WILL HOLD OFF UNTIL FRIDAY EVENING
BUT DID ALLOW A SLIGHT CHANCE TO RESIDE FAR SOUTHWEST AFTER 21Z WITH
PROXIMITY OF INCREASING MOISTURE AND ISENTROPIC LIFT.
&&
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 323 PM EST THU DEC 12 2013
...ACCUMULATING SNOWFALL FRIDAY NIGHT-SATURDAY...
PATTERN IS STILL SUPPORTIVE OF FAVORABLE SYNOPTIC SCALE SNOW EVENT
FOR THE REGION BEGINNING LATE FRIDAY NIGHT AND CONTINUING INTO THE
DAY SATURDAY.
NORTHERN STREAM FLOW WILL KEEP THE BOUNDARY LAYER COLD AIR IN PLACE
AND DEEP ENOUGH TO FAVOR ALL SNOW FOR THE EVENT. THE CHALLENGE WILL
BE TIMING THE PHASING OF THE SOUTHERN STREAM AND NORTHERN STREAM
SHORTWAVES ACROSS THE GREAT LAKES.
12Z RUNS ARE GENERALLY CONSISTENT WITH THE SURFACE LOW DEEPENING IN
THE PANHANDLE REGION DURING THE DAY FRIDAY. CONTINUED DEEPENING AND
OF THE SURFACE LOW OVER THE SOUTHERN PLAINS AND LOWER MISSISSIPPI
RIVER VALLEY DURING THE EVENING FRIDAY INTO SATURDAY WILL USHER IN
COPIOUS MOISTURE AND EXPECT TO SEE A PRONOUNCED WARM LAYER SPREADING
NORTHWARD. THIS WILL FAVOR A MORE DENSE AND WET SNOW ACROSS THE
SOUTH.
TIMING AND PHASING OF THE SOUTHERN AND NORTHERN STREAM WILL
CRITICALLY AFFECT THE DURATION OF THE SNOW AND EXPECT THAT THERE
WILL BE A RAPID CUTOFF OF PRECIPITATION EARLY SATURDAY.
SNOWFALL WILL BE HEAVIEST AND WETTER SOUTH OF THE CWFA AND DRIER
NORTH. REGARDLESS EXPECT TO SEE UPWARDS OF 5 INCHES ACROSS MOST OF
THE AREA.
AS THE SYNOPTIC DRIVEN SNOW ENDS...LAKE EFFECT SHOULD CONTINUE IN
LAPORTE...ST. JOSEPH...BERRIEN AND CASS COUNTIES FOR AN ADDITIONAL 2
TO 4 INCHES BY SATURDAY NIGHT EARLY SUNDAY MORNING.
COLDER AND DRIER AIR WILL SETTLE ACROSS THE PLAINS SUNDAY AND WITH
NEW SNOW AND SOME CLEARING...TEMPERATURES SHOULD BOTTOM OUT AGAIN
SUNDAY NIGHT/MONDAY MORNING. WILL BE MAKING SOME DOWNWARD
ADJUSTMENTS TO THE TEMPERATURES FOR SUN/MON PERIOD.
NEXT CLIPPER SYSTEM FORMS IN THE GREAT LAKES REGION MONDAY/MONDAY
NIGHT/TUESDAY AND THIS WILL BRING AN INCREASE OF CLOUDS AND LAKE
EFFECT TO THE AREA. TIMING AND DURATION OF SNOWFALL IS TOO FAR OUT
TO MAKE DEFINITIVE AMOUNT FORECASTS...BUT IT WILL ADD TO THE SNOW
ALREADY ON THE GROUND. AS THAT SYSTEM EXITS...THE COLD AIR RETURNS
IN ITS WAKE. STARTING TO SEE A DECENT SNOW PACK OVER THE NRN
PLAINS...ADDING TO THE DOUBT THAT ANY SIZABLE WARM UP IS COMING OUR
WAY.
NEXT STORY ON THE HORIZON...ECMWF PREDICTION OF DEEP AND EXPLOSIVE
CYCLOGENESIS ACROSS THE NORTHERN AND CENTRAL PLAINS WEDNESDAY NIGHT
INTO THURSDAY. THERE ARE HINTS IN THE OTHER LONG RANGE MODELS OF A
WAVE EJECTING THROUGH THE ROCKIES. THIS WILL HAVE TO BE WATCHED AS
THE PATTERN EVOLVES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1238 AM EST FRI DEC 13 2013
THE FIRST HALF OF THE TAF PERIOD WILL BE RATHER UNEVENTFUL WITH
VFR CONDITIONS AT BOTH SITES AS WE AWAIT THE ARRIVAL OF LOW
PRESSURE FROM THE SOUTHWEST AND A FRONTAL BOUNDARY FROM THE NORTH.
HAVE BACKED OFF ON ARRIVAL OF MVFR CIGS AT KSBN IN RESPONSE TO
SOUTHWARD MOVING FRONT AS MODELS CONTINUE TO TREND A BIT SLOWER
WITH THIS FEATURE ARRIVING. MAIN FOCUS WILL BE WITH ONSET OF SNOW
TONIGHT WITH RAPID ONSET OF SNOW IN THE 3 TO 6Z WINDOW AND SIMILAR
FLGT CONDITIONS AT BOTH SITES. AFTER 6Z AND WELL INTO THE NEXT
DAY...IFR/POSSIBLE LIFR CIGS/VSBYS WILL ARRIVE WITH MAIN FOCUS
POINTING TOWARDS KFWA WHERE HEAVIEST SNOW MAY OCCUR. FURTHER
DETAILS WILL BE ADDED IN LATER FORECASTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY FROM 7 PM EST /6 PM CST/ THIS EVENING TO
7 PM EST /6 PM CST/ SATURDAY FOR INZ003>009-012>018-020-
022>027-032>034.
MI...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
SATURDAY FOR MIZ077>081.
OH...WINTER WEATHER ADVISORY FROM 7 PM THIS EVENING TO 7 PM EST
SATURDAY FOR OHZ001-002-004-005-015-016-024-025.
LM...SMALL CRAFT ADVISORY UNTIL 4 AM EST EARLY THIS MORNING FOR
LMZ043.
&&
$$
UPDATE...JT
SYNOPSIS...LASHLEY
SHORT TERM...LASHLEY
LONG TERM...LEWIS
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.NORTHERNIN.GOV
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
248 AM CST Fri Dec 13 2013
...Updated for Short and Long Term...
.SYNOPSIS...
ISSUED AT 242 AM CST FRI DEC 13 2013
The center of an upper low was moving across Arizona overnight as
observed on water vapor imagery. Just upstream was a broad area of
positive vorticity advection across new Mexico into the panhandles,
where the leading edge of the upper jet was also located. Very weak
pressure falls were occurring and were widespread from the northern
High Plains region of Wyoming and Nebraska to north central Texas.
METAR objective analysis indicated warm surface frontogenesis was
developing from southeast Colorado into western Oklahoma. An
extremely dry 00 UTC KDDC sounding was likely contributing to a
pronounced lack of radar precipitation echoes advancing any farther
than the Oklahoma/Kansas line near Coldwater and Medicine lodge.
Surface temperatures around 1 am were steady to slowly warming south
and east of Dodge city.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 242 AM CST FRI DEC 13 2013
The last run of the NAM and recent HRRR models appeared to represent
the thermodynamic and precipitation areal coverage very well by
keeping extremely low precipitation/QPF accumulations mainly across
western Oklahoma into areas of western Kansas east of Medicine
Lodge. Even with the advancing upper system from the southern
Rockies, the isentropic fields indicate an increasingly downslope
profile after about 09-12 UTC.
The WRF model is still having problems with ground snow across the
I-70 corridor, which hasn`t existed for a few days. However the
solution is probably not bad farther south and west where it
forecasts temperatures as high as around 50 degrees. As the pressure
falls persist, a surface low will develop southeastward into the
panhandles this afternoon. The local GFS mos products forecast
stronger surface winds behind the attendant surface cold frontal
boundary later into Friday night especially toward midnight. This is
a reasonable solution as the surface low will move rapidly across
the southern plains and the upper trough swings across the region
just in time to add to a deep subsident profile for western
Kansas.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 242 AM CST FRI DEC 13 2013
A significant Arctic outbreak is the offing coming up next Thursday
or Friday time frame. As with many Arctic events, the long range
models struggle with the timing and normally are too slow with these
Arctic fronts. Current long range model trends are suggesting a bit
slower solution to the Arctic fropa, but like mentioned above they
do not normally pan out that way. Current thoughts are a frontal
passage around Thursday afternoon. There may be a strong temperature
contrast by Thursday afternoon from Hays to Medicine Lodge. Current
high temps from the mid 40s around Hays to the low to mid 50s in the
Medicine Lodge area may need significant adjustment downward if a
faster solution bears out. Some light snow is also possible into
next weekend of December 21st and 22nd, however should be light
accumulations.
Ahead of the Arctic front, from Saturday into Wednesday, a warming
trend begins Sunday with temperatures rising from the low to mid 40s
on Saturday behind a cold front, and into the 50s through Wednesday.
A cold upper trough will be moving across the Plains on Saturday
followed by dry northwest flow aloft and downslope and warmer
surface winds. Overnight lows look to gradually warm from the low to
mid 20s on Saturday night into the upper 20s into Wednesday night.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday night)
ISSUED AT 1128 PM CST THU DEC 12 2013
There is good agreement between the short term mesoscale models that
any precipitation will be focused across south central Kansas and
have not impact of the local terminals (DDC/GCK/HYS). Beyond this,
the only concerns remain some chance for fog development between 10
and 14 UTC which is not expected to be widespread but patchy at best,
and a wind shift later Friday morning that will bring increasingly
stronger surface winds through Friday night behind the cold front.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 21 43 23 / 0 10 0 0
GCK 50 20 46 21 / 0 0 0 0
EHA 49 23 46 24 / 0 0 0 0
LBL 50 22 46 24 / 0 0 0 0
HYS 42 17 39 21 / 10 10 0 0
P28 49 22 40 22 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Kruse
AVIATION...Russell
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1038 PM MST THU DEC 12 2013
.UPDATE...
ISSUED AT 605 PM MST THU DEC 12 2013
JUST COMPLETED AN UPDATE. MODELS HAVING A HARD TIME WITH THE SURFACE
WIND FIELD AND DEWPOINTS. WITH THE EXCEPTION OF THE FAR EAST...LOWER
DEWPOINTS COMBINED WITH THE LIGHT WIND FIELD...AS A SURFACE TROUGH
MOVES ACROSS...HAVE ALLOWED TEMPERATURES FALL RATHER RAPIDLY.
LATEST ADJMAV AND RAP ARE HANDLING THE WINDS...DEWPOINTS AND
TEMPERATURES THE BEST. SO USED THOSE COMBINED WITH REALITY TO MAKE
THOSE ADJUSTMENTS. ALSO A LITTLE MORE CLOUD COVER FROM THE SOUTH
MOVING SO ADJUSTED THAT UP SLIGHTLY.
&&
.SHORT TERM...(THIS AFTERNOON THROUGH FRIDAY)
ISSUED AT 1154 AM MST THU DEC 12 2013
A WEAK SHORTWAVE TROUGH WILL MOVE THROUGH THE SOUTHERN PLAINS
TONIGHT AND FRIDAY. HOWEVER THE BEST FORCING WILL STAY WELL TO THE
SOUTH AND MOISTURE WILL BE LACKING ANYWAY. THE SURFACE TROUGH IN
EASTERN COLORADO WILL MOVE TO CENTRAL KANSAS BY FRIDAY MORNING
FOLLOWED BY A COLD FRONT AROUND MID DAY. NET RESULT WILL SEE
SURFACE WINDS SHIFTING TO NORTHWEST AND BECOMING BREEZY FRIDAY
AFTERNOON BEHIND THE FRONT. TEMPERATURES WILL BE NEAR
NORMAL...EXCEPT IN THE VERY LIMITED AREAS WHERE LINGERING SNOW
COVER MAY KEEP THEM SLIGHTLY BELOW NORMAL (MAINLY THE OBERLIN TO
MCCOOK AREA).
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 147 PM MST THU DEC 12 2013
FRIDAY NIGHT-MONDAY...SHORTWAVE TROUGH QUICKLY TRANSITIONS EAST
FRIDAY NIGHT AND NORTHWESTERLY FLOW REDEVELOPS OVER THE NORTHERN
PLAINS ALONG WITH RIDGING ACROSS THE SOUTHWESTERN US. OTHER THAN
PASSING MID-HIGH CLOUDS FRIDAY NIGHT AND AGAIN SATURDAY NIGHT WITH
EMBEDDED SHORTWAVE TROUGHS I ANTICIPATE DRY CONDITIONS TO CONTINUE
AS THE STORM TRACK WILL FAVOR LOCATIONS WELL NORTH OF THE CWA AND
A VERY DEEP DRY AIR MASS BELOW 600MB WILL BE SETTLING INTO THE
REGION. A BACKDOOR COLD FRONT WILL KEEP NEAR SEASONAL TEMPS IN
PLACE FRIDAY AND SATURDAY BEFORE TEMPS BEGIN MODERATING ALOFT IN
RESPONSE TO WEST-SOUTHWEST FLOW IN THE LOWER LEVELS OF THE
ATMOSPHERE SUNDAY AND MONDAY. IN RESPONSE TO GOOD WAA I WOULD
EXPECT HIGHS BOTH SUNDAY AND MONDAY TO BE IN THE 50S ACROSS THE
REGION WITH MID 50S ALONG THE CO/KS BORDER (IF NOT HIGHER WITH
GOOD MIXING).
MONDAY NIGHT-WEDNESDAY...FORECAST BECOMES TRICKIER IN THESE PERIODS
AS MODELS HAVE SHOWN LESS CONSISTENCY/CONTINUITY ON TIMING/EVOLUTION
OF TWO STRONG UPPER LEVEL TROUGHS MOVING OUT OF CANADA. THE FIRST
TROUGH SHOULD PASS OVER THE GREAT LAKES REGION MONDAY NIGHT/TUESDAY
TIME FRAME AND GFS IS MUCH STRONGER AND PUSHES A COLD FRONT
SOUTH OVER OUR CWA. ECMWF AND GEM ARE FURTHER NORTH WITH THE INITIAL
TRACK AND HAS CONSISTENTLY SHOW RIDGING ACROSS THE WESTERN US...AND
THE COLD FRONT REMAINING NORTH AND EAST OF OUR CWA. WHILE EITHER
SOLUTION SUPPORTS DRY WEATHER FOR OUR AREA...THERE IS A LARGE SPREAD
IN TEMPERATURES THROUGH THESE PERIODS. BASED ON BETTER CONTINUITY I
TRENDED THE FORECAST FROM THE MODEL CONSENSUS MEAN TOWARDS THE
WARMER ECMWF SOLUTION...WHICH KEEPS ABOVE NORMAL TEMPS IN PLACE
THROUGH WEDNESDAY.
THURSDAY...GEFS/GFS/ECMWF SHOW A LARGE CHANGE IN THE PATTERN AS A
STRONG TROUGH MOVES INTO THE CENTRAL PLAINS AND AN ARCTIC FRONT
DROPS SOUTH OVER OUR CWA. THERE ARE TIMING DIFFERENCES WITH THIS
FRONT...HOWEVER THE OVERALL TREND SHOULD BE THE RETURN OF MUCH
COLDER TEMPS AND THE POSSIBILITY OF ACCUMULATING SNOW BY LATE NEXT
WEEK OR NEXT WEEKEND. BASED ON PAST EXPERIENCE I WOULD NOT BE
SURPRISED IF THE FRONT TIMING IS IN LINE WITH THE FASTER END OF
GUIDANCE AS THE MOMENTUM OF THE VERY COLD/DENSE AIR MASS CARRIES
IT SOUTH ACROSS THE PLAINS AHEAD OF THE MAIN TROUGH THURSDAY.
THERE IS TOO MUCH UNCERTAINTY AT THIS RANGE TO PICK ONE
SOLUTION...SO FOR THIS FORECAST PACKAGE I HAVE SEASONAL HIGHS IN
THE LOW-MID 40S WHICH IS CLOSE TO MODEL MEAN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1035 PM MST THU DEC 12 2013
VFR CONDITIONS WITH VARIABLE AMOUNTS OF HIGH CLOUD COVER EXPECTED
THROUGH THE PERIOD. WINDS WILL BE LIGHT AND VARIABLE AS A
PREFRONTAL TROUGH MOVES THROUGH DURING THE OVERNIGHT AND MORNING
HOURS. BY MIDDAY...A COLD FRONT WILL MOVE THROUGH AND BRING GUSTY
WINDS TO BOTH SITES...HIGHER AT KGLD...THROUGH THE AFTERNOON. THE
GUSTS END BY LATE IN THE AFTERNOON.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
CO...NONE.
NE...NONE.
&&
$$
UPDATE...BULLER
SHORT TERM...024
LONG TERM...DR
AVIATION...BULLER
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 AM EST FRI DEC 13 2013
.UPDATE...
ISSUED AT 942 PM EST THU DEC 12 2013
MAIN FCST CONCERN THIS EVNG HAS BEEN ON TIMING/IMPACT OF INTENSE LES
BAND SHOWN ON MQT 88D OVER SCENTRAL LK SUP EXTENDING INTO FAR ERN
ALGER/NRN LUCE COUNTIES. THIS BAND HAS BEEN NEARLY STNRY THRU MUCH
OF THE EVNG...WITH HIEST REFLECTIVITIES APRCHG 30 DBZ AS HI AS 6-7K
FT...PROMPTING ISSUANCE OF AN SPS EARLIER IN THE EVNG. CALL TO
SPOTTER JUST S OF GRAND MARAIS INDICATED SN FALLING AT THE RATE OF
AN INCH/HR WITH TOTAL ACCUMULATION FM NOON THRU 9 PM ARND 7 INCHES.
THE BAND INTENSIFIED DURING THE EVNG WITH SHARPENING LLVL CNVGC
ACCOMPANYING MORE PRONOUNCED LAND BREEZE SW WIND COMPONENT ON THE
SRN FLANK OF THE BAND. CONSIDERED UPGRADING ADVY TO WRNG TO THIS
AREA...BUT RECENT RADAR IMAGERY INDICATES THE BAND IS BEGINNING TO
SHIFT TO THE S IN LINE WITH VEERING LLVL WINDS TO THE NW...WHICH IS
IN AGREEMENT WITH HIER RES MODEL FCSTS. IN FACT...NEARBY SFC OBS/MQD
88D VWP DO SHOW A VEERING TREND. WITH THE STEADY VEERING EXPECTED
THRU THE NGT AND FCST WEAKENING LAND BREEZE CNVGC...EXPECT THE BAND
TO MOVE MORE STEADILY AND DIMINISH A BIT WITH TIME. WITH WEAKER
MULTIPLE BANDED LES EXPECTED TO DOMINATE...WL HOLD ON TO GOING ADVY
FOR ALGER/LUCE/NRN SCHOOLCRAFT COUNTIES.
OTRW...TENDED TO BUMP UP MIN TEMPS FCST A FEW DEGREES WITH QUITE A
BIT OF CLD COVER AND WSHFT TO A MORE N DIRECTION ALLOWING FOR MORE
LK SUP MODERATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
ACROSS ERN NOAM RESULTING IN NW FLOW THROUGH THE NRN GREAT LAKES. A
SHORTWAVE TROUGH WAS MOVING THROUGH NW ONTARIO DRAGGING A COLD FRONT
THROUGH WRN LAKE SUPERIOR. FARTHER UPSTREAM...A WEAK CLIPPER SHRTWV
WAS MOVING FROM SRN SASK INTO THE NRN PLAINS. LES BANDS ALIGNED WITH
WNW FLOW THROUGH ERN LAKE SUPERIOR INTO NE ALGER AND NRN LUCE
COUNTIES HAD DIMINISHED SLIGHTLY AND BECOME MORE CELLULAR THIS
AFTERNOON WITH WEAKENING LOW LEVEL CONV FROM LAND BREEZE COMPONENT.
EXPECT THAT THE LOW LEVEL WINDS WILL DIMINISH AND VEER FROM WNW TO
NRLY. THIS SHOULD PUSH THE MORE SIGNIFICANT LES THROUGH MUCH OF THE
ERN CWA FROM ALGER COUNTY EASTWARD AS A STRENGTHENING LAND BREEZE
SHOULD KEEP MOST OF THE SNOW EAST OF MARQUETTE. EVEN WITH THE
SHIFTING POSITION OF THE LES BANDS...FAVORABLE SNOW GROWTH WITH THE
DGZ IN THE 1K-4K CONVECTIVE LAYER PUSHING SLR VALUES ABOVE 25/1 AND
SHOULD SUPPORT ADVISORY SNOWFALL AMOUNTS IN THE 3 TO 6 INCH RANGE.
OVER THE WEST...THE SHORTER FETCH...ACYC FLOW AND LOWER INVERSION
HEIGHTS FROM 3K-4K FT...WILL KEEP SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE.
FROM LATE TONIGHT INTO EARLY FRI...THE SASK SHRTWV AND WEAK UPPER
LEVEL DIV WITH THE RIGHT ENTRANCE OF A 140 KT 250-300 MB JET WITH
ASSOCIATED 800-600 MB FGEN MAY SUPPORT A BAND OF LIGHT SNOW.
HOWEVER...MODELS SUGGEST THAT THE BEST CHANCE OF LIGHT SNOW WITH
THESE FEATURES WILL REMAIN OVER WI. SO...ONLY CHANCE POPS WITH
ACCUMULATIONS LESS THAN A HALF INCH WERE INCLUDED.
WINDS WILL CONTINUE TO VEER FRIDAY AS ARCTIC HIGH PRES FROM
SASK/MANITOBA INTO NRN ONTARIO BUILDS INTO THE NRN LAKES. WITH WINDS
SHIFTING FROM N TO NNE THE MOST FAVORABLE LOW LEVEL CONV WILL SHIFT
FROM THE NE CWA INTO MARQUETTE COUNTY. WHILE SNOW GROWTH WILL REMAIN
FAVORABLE...INVERSION HEIGHT REMAINING NEAR 5K-6K FT WITH MAINLY
ACYC UPSTREAM FLOW MAY LIMIT LES INTENSITY AND SNOWFALL AMOUNTS
BELOW ADVY LEVELS. GENERALLY 1 TO 3 INCHES ARE EXPECTED WITH THE
GREATEST AMOUNTS IN FAR WRN ALGER COUNTY INTO ERN MARQUETTE COUNTY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 423 AM EST FRI DEC 13 2013
NAM SHOWS A 500 MB RIDGE OVER THE WESTERN U.S. 12Z SAT WITH A
SHORTWAVE TROUGH OVER THE CENTRAL U.S. A CLOSED 500 MB LOW OVER
NORTHERN MANITOBA DIGS SOUTHEAST ON SAT AND DIGS A DEEPER TROUGH
INTO THE UPPER GREAT LAKES WHICH AFFECTS THE AREA LATE ON SAT INTO
SAT NIGHT. THIS TROUGH MOVES INTO THE LOWER GREAT LAKES ON SUN.
NAM SHOWS SOME 850-500 MB Q-VECTOR CONVERGENCE AND SOME DEEPER
MOISTURE SAT NIGHT AND BOTH LEAVE ON SUN. LOOKS LIKE THERE COULD BE
SOME LAKE ENHANCEMENT WITH EAST FLOW GOING ON OVER THE KEWEENAW AND
ALSO FROM LAKE MICHIGAN ACROSS MENOMINEE AND DELTA COUNTIES ON
SATURDAY WITH A DRY WEDGE OF AIR IN BETWEEN OVER THE CENTRAL AND
EASTERN CWA IN THE MORNING AND TRIED TO REFLECT THE TWO AREAS OF
PCPN IN THE POPS GRIDS. WILL GO CATEGORICAL WITH THE LAKE
ENHANCEMENT OVER SOUTHERN MENOMINEE AND ACROSS THE NORTHERN KEWEENAW
PENINSULA AS LAKE TEMPERATURES ARE AROUND 4C AND GFS AND NAM ARE
SHOWING 850 MB TEMPERATURES OF -16C TO -20C. THESE AREAS MIGHT NEED
ADVISORIES FOR LAKE ENHANCED SNOWFALL AS THERE COULD BE 4-6 INCHES
OF SNOW SAT AND SAT NIGHT WITH THIS NEXT SYSTEM. WILL LET DAY SHIFT
LOOK AT THIS POSSIBILITY AGAIN...BUT RIGHT NOW LOOKS LIKE ADVISORY
SNOWFALL. THIS DRY AIR ERODES IN THE AFTERNOON AND WENT CHANCE POPS
ACROSS THE CENTRAL AND EAST THEN. LAKE EFFECT STARTS SAT NIGHT
ACROSS THE WEST IN NORTHWEST LAKE EFFECT SNOW BELTS AND THIS
CONTINUES INTO SUNDAY EVENING. DID NOT MAKE TOO MANY ADJUSTMENTS TO
GOING TEMPERATURES EXCEPT TO LOWER LOW TEMPERATURES A BIT MORE
DURING THE NIGHTS WITH LIGHTER WINDS.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH ACROSS
THE U.S. 12Z MON. THIS BROAD TROUGH REMAINS 12Z TUE WITH A STRONGER
SHORTWAVE DIGGING INTO THE UPPER GREAT LAKES. THIS TROUGH MOVES INTO
THE EASTERN U.S. 12Z WED. ECMWF THEN SHOWS A STRONG TROUGH DIGGING
INTO THE ROCKIES 12Z THU WHILE THE GFS IS ZONAL WITH ITS UPPER FLOW
AND SOLUTION IS TOTALLY DIFFERENT. THE GFS HAS A HIGH PRESSURE
SYSTEM OVER THE GREAT LAKES 12Z THU. LOOKING AT THE MANUAL
PROGS...LOOKS LIKE THE ECMWF SOLUTION WAS FOLLOWED ON THU. STILL
LOOKS COLDER THAN NORMAL THIS FORECAST PERIOD. WILL HAVE CHANCE POPS
IN FOR MONDAY WITH PASSAGE OF A SHORTWAVE ACROSS THE AREA AND THEN
MON NIGHT THERE COULD BE SOME LAKE ENHANCEMENT OVER THE EASTERN CWA
OFF OF LAKE MICHIGAN AND WENT LIKELY POPS THERE WITH CHANCE POPS
ELSEWHERE. FOR TUE...LAKE EFFECT SNOW OFF OF LAKE SUPERIOR STARTS UP
AND WENT CHANCE POPS FOR THEN AND THEN THE NEXT SYSTEM COMES IN FOR
THU AND WENT CHANCE POPS THEN.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1229 AM EST FRI DEC 13 2013
CMX...EXPECT IFR VSBYS WITH FALLING SN/BLSN IN GUSTY NW FLOW EARLY
IN THE FCST PERIOD TO GIVE WAY TO MVFR CONDITIONS AS THE FLOW
WEAKENS AND VEERS TO A MORE UNFVRBL NNE DIRECTION.
IWD...AS THE FLOW VEERS TOWARD AN UPSLOPE N AND NE DIRECTION...
EXPECT LK EFFECT -SHSN TO INCRS AT IWD EARLY THIS MRNG. SO MVFR
CONDITIONS EARLY IN THE TAF PERIOD SHOULD DETERIORATE TO IFR BY
SUNRISE. AS THE LLVL WINDS VEER FURTHER TO A MORE UNFVRBL NE THEN E
DIRECTION FRI AFTN/EVNG...CONDITIONS ARE LIKELY TO IMPROVE TO MVFR
AND PERHAPS VFR BY EVNG.
SAW...EXPECT VFR CONDITIONS EARLY THIS MRNG TO DETERIORATE TO MVFR
BY SUNRISE AS THE FLOW VEERS TOWARD THE N FOLLOWING A LO PRES TROF
PASSAGE. WITH A CONTINUED VEERING TO AN UPSLOPE NNE DIRECTION THIS
AFTN...VSBYS ARE LIKELY TO FALL TO IFR WITH MORE FREQUENT ENHANCED
SHSN. AS THE FLOW VEERS FURTHER LATER THIS EVNG TOWARD A LESS FVRBL
E DIRECTION...CONDITIONS WL REBOUND TO MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST THU DEC 12 2013
A PERIOD OF WNW TO NW GALES IS EXPECTED LATE THIS AFTERNOON THROUGH
THIS EVENING BEFORE DIMINISHING OVERNIGHT WITH HIGH PRES BUILDING
TOWARD THE REGION. HEAVY FREEZING SPRAY WILL ALSO CONTINUE FOR MUCH
OF THE LAKE INTO THIS EVENING. WINDS WILL FINALLY DIMINISH TO
NORTHERLY AT 15 TO 25 KNOTS OVERNIGHT INTO FRIDAY MORNING AS A WEAK
RIDGE PASSES ACROSS THE LAKE. EXPECT 10 TO 20 KT WINDS TO GRADUALLY
BACK TO THE SE BY SATURDAY AHEAD OF DEVELOPING LOW PRESSURE OVER THE
UPPER MS VALLEY. DEPENDING ON THE STRENGTH OF THE LOW AS IT MOVES
ACROSS LAKE SUPERIOR ON SATURDAY NIGHT AND SUNDAY AND THE STRENGTH OF
ANOTHER LOW MOVING UP THE EAST COAST...COULD SEE AN INCREASE IN
NORTHWESTERLY WINDS ON SUNDAY TO 25 TO 30 KTS. THIS WILL BE SHORT-
LIVED AS ANOTHER HIGH SLIDES INTO THE AREA FOR THE BEGINNING OF THE
UPCOMING WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 6 PM EST THIS EVENING FOR MIZ006.
LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MIZ007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ263>266.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...JLB
LONG TERM...07
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1230 AM EST FRI DEC 13 2013
.UPDATE...
ISSUED AT 942 PM EST THU DEC 12 2013
MAIN FCST CONCERN THIS EVNG HAS BEEN ON TIMING/IMPACT OF INTENSE LES
BAND SHOWN ON MQT 88D OVER SCENTRAL LK SUP EXTENDING INTO FAR ERN
ALGER/NRN LUCE COUNTIES. THIS BAND HAS BEEN NEARLY STNRY THRU MUCH
OF THE EVNG...WITH HIEST REFLECTIVITIES APRCHG 30 DBZ AS HI AS 6-7K
FT...PROMPTING ISSUANCE OF AN SPS EARLIER IN THE EVNG. CALL TO
SPOTTER JUST S OF GRAND MARAIS INDICATED SN FALLING AT THE RATE OF
AN INCH/HR WITH TOTAL ACCUMULATION FM NOON THRU 9 PM ARND 7 INCHES.
THE BAND INTENSIFIED DURING THE EVNG WITH SHARPENING LLVL CNVGC
ACCOMPANYING MORE PRONOUNCED LAND BREEZE SW WIND COMPONENT ON THE
SRN FLANK OF THE BAND. CONSIDERED UPGRADING ADVY TO WRNG TO THIS
AREA...BUT RECENT RADAR IMAGERY INDICATES THE BAND IS BEGINNING TO
SHIFT TO THE S IN LINE WITH VEERING LLVL WINDS TO THE NW...WHICH IS
IN AGREEMENT WITH HIER RES MODEL FCSTS. IN FACT...NEARBY SFC OBS/MQD
88D VWP DO SHOW A VEERING TREND. WITH THE STEADY VEERING EXPECTED
THRU THE NGT AND FCST WEAKENING LAND BREEZE CNVGC...EXPECT THE BAND
TO MOVE MORE STEADILY AND DIMINISH A BIT WITH TIME. WITH WEAKER
MULTIPLE BANDED LES EXPECTED TO DOMINATE...WL HOLD ON TO GOING ADVY
FOR ALGER/LUCE/NRN SCHOOLCRAFT COUNTIES.
OTRW...TENDED TO BUMP UP MIN TEMPS FCST A FEW DEGREES WITH QUITE A
BIT OF CLD COVER AND WSHFT TO A MORE N DIRECTION ALLOWING FOR MORE
LK SUP MODERATION.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
ACROSS ERN NOAM RESULTING IN NW FLOW THROUGH THE NRN GREAT LAKES. A
SHORTWAVE TROUGH WAS MOVING THROUGH NW ONTARIO DRAGGING A COLD FRONT
THROUGH WRN LAKE SUPERIOR. FARTHER UPSTREAM...A WEAK CLIPPER SHRTWV
WAS MOVING FROM SRN SASK INTO THE NRN PLAINS. LES BANDS ALIGNED WITH
WNW FLOW THROUGH ERN LAKE SUPERIOR INTO NE ALGER AND NRN LUCE
COUNTIES HAD DIMINISHED SLIGHTLY AND BECOME MORE CELLULAR THIS
AFTERNOON WITH WEAKENING LOW LEVEL CONV FROM LAND BREEZE COMPONENT.
EXPECT THAT THE LOW LEVEL WINDS WILL DIMINISH AND VEER FROM WNW TO
NRLY. THIS SHOULD PUSH THE MORE SIGNIFICANT LES THROUGH MUCH OF THE
ERN CWA FROM ALGER COUNTY EASTWARD AS A STRENGTHENING LAND BREEZE
SHOULD KEEP MOST OF THE SNOW EAST OF MARQUETTE. EVEN WITH THE
SHIFTING POSITION OF THE LES BANDS...FAVORABLE SNOW GROWTH WITH THE
DGZ IN THE 1K-4K CONVECTIVE LAYER PUSHING SLR VALUES ABOVE 25/1 AND
SHOULD SUPPORT ADVISORY SNOWFALL AMOUNTS IN THE 3 TO 6 INCH RANGE.
OVER THE WEST...THE SHORTER FETCH...ACYC FLOW AND LOWER INVERSION
HEIGHTS FROM 3K-4K FT...WILL KEEP SNOWFALL AMOUNTS IN THE 1 TO 3
INCH RANGE.
FROM LATE TONIGHT INTO EARLY FRI...THE SASK SHRTWV AND WEAK UPPER
LEVEL DIV WITH THE RIGHT ENTRANCE OF A 140 KT 250-300 MB JET WITH
ASSOCIATED 800-600 MB FGEN MAY SUPPORT A BAND OF LIGHT SNOW.
HOWEVER...MODELS SUGGEST THAT THE BEST CHANCE OF LIGHT SNOW WITH
THESE FEATURES WILL REMAIN OVER WI. SO...ONLY CHANCE POPS WITH
ACCUMULATIONS LESS THAN A HALF INCH WERE INCLUDED.
WINDS WILL CONTINUE TO VEER FRIDAY AS ARCTIC HIGH PRES FROM
SASK/MANITOBA INTO NRN ONTARIO BUILDS INTO THE NRN LAKES. WITH WINDS
SHIFTING FROM N TO NNE THE MOST FAVORABLE LOW LEVEL CONV WILL SHIFT
FROM THE NE CWA INTO MARQUETTE COUNTY. WHILE SNOW GROWTH WILL REMAIN
FAVORABLE...INVERSION HEIGHT REMAINING NEAR 5K-6K FT WITH MAINLY
ACYC UPSTREAM FLOW MAY LIMIT LES INTENSITY AND SNOWFALL AMOUNTS
BELOW ADVY LEVELS. GENERALLY 1 TO 3 INCHES ARE EXPECTED WITH THE
GREATEST AMOUNTS IN FAR WRN ALGER COUNTY INTO ERN MARQUETTE COUNTY.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 419 PM EST THU DEC 12 2013
MODELS TODAY CONTINUE TO INDICATE AN OVERALL COLD PATTERN THRU THE
LONG TERM PORTION OF THE FCST. HOWEVER...WITH CURRENT DEEP EXPANSIVE
POLAR VORTEX CENTERED AROUND HUDSON BAY STILL FCST TO WEAKEN AND
RETREAT N THRU AT LEAST THE MIDDLE OF NEXT WEEK...THE COLD WILL EASE
SOME. A VAST SUPPLY OF COLD AIR WILL REMAIN ACROSS CANADA...SO ANY
SHORTWAVE TRACKING ALONG IN THE RELAXING NW FLOW PATTERN WILL BE
ABLE TO TUG COLDER AIR INTO THE UPPER LAKES. FOR THIS REASON...
MEDIUM RANGE GUIDANCE FOR SEVERAL DAYS HAS BEEN PROGRESSIVELY SLOWER
TO BRING WARMING INTO THE UPPER LAKES AND HAS ALSO BEEN MORE
TEMPERED WITH THE WARMING. AROUND THE MIDDLE OF NEXT WEEK THERE WILL
BE A TEMPORARY SHIFT IN THE PATTERN TOWARD A DEEPENING TROF OVER THE
WRN CONUS AND DOWNSTREAM BUILDING RIDGE OVER THE SE CONUS/WRN
ATLANTIC. THUS THE MIDWEEK PERIOD WILL OFFER THE BEST CHANCE OF A
WARMUP. HOW MUCH WARMING OCCURS WILL DEPEND ON THE AMPLITUDE AND
LONGITUDE OF THE TROF/RIDGE PATTERN. LATEST MODEL TRENDS POINT
TOWARD AN EWD SHIFT IN THE TROF/RIDGE PATTERN WHICH WILL LIMIT
WARMING FOR THE UPPER LAKES. IN ANY CASE...WARMING WILL ONLY BE
BRIEF AS LONGER RANGE GUIDANCE CONTINUES TO POINT TOWARD
REINTENSIFYING ARCTIC AIR ACROSS WRN/NRN CANADA DUMPING BACK INTO
THE AREA SOMETIME AROUND THE WEEKEND BEFORE CHRISTMAS. OUTSIDE OF
AREAS AFFECTED BY LES/LAKE ENHANCEMENT...THERE WON`T BE MUCH MORE
THAN SOME -SN AT TIMES DURING THE LONG TERM. THE RESURGENCE OF
ARCTIC AIR S INTO THE CONUS LATE NEXT WEEK/WEEKEND COULD OFFER THE
POTENTIAL FOR SOMETHING MORE SUBSTANTIAL IN TERMS OF WIDESPREAD
SNOWFALL.
BEGINNING FRI NIGHT...WINDS WILL CONTINUE VEERING TO THE E THEN
SE FRI NIGHT/SAT MORNING AS SFC HIGH PRES CENTER PASSES JUST N OF
LAKE SUPERIOR AND NEXT CLIPPER SHORTWAVE APPROACHES FROM THE NW. LES
THAT WILL BE OCCURRING MAINLY INTO NCNTRL UPPER MI THU AFTN WILL
SLOWLY SHIFT OUT OF NCNTRL UPPER MI AND THEN CROSS THE KEWEENAW
PENINSULA FOR A TIME LATE FRI NIGHT/SAT MORNING. DGZ WILL BE WELL
CENTERED IN THE CONVECTIVE LAYER...SO A FEW INCHES OF FLUFFY SNOW
ARE POSSIBLE IN THIS AREA OF LES THAT WILL BE SHIFTING WITH THE
WINDS. ALSO...WITH WINDS VEERING OVER NRN LAKE MI...LES OFF LAKE MI
WILL LIKELY MOVE INTO MENOMINEE COUNTY AND POSSIBLY DELTA COUNTY...
LEADING TO SOME FLUFFY SNOW ACCUMULATIONS LATE FRI NIGHT/SAT
MORNING.
ATTENTION THEN TURNS TO NEXT CLIPPER SHORTWAVE DROPPING THRU THE
UPPER GREAT LAKES SAT NIGHT/SUN. -SN ASSOCIATED WITH FEATURE SHOULD
SPREAD INTO THE AREA SAT AFTN/EVENING...AND IT LOOKS LIKE THERE WILL
BE A PERIOD OF LAKE ENHANCEMENT OFF LAKE MI IN SOUTHERLY FLOW...
LEADING TO A POTENTIAL ADVY EVENT. A BRIEF SHOT OF ARCTIC AIR
FOLLOWING SYSTEM WILL PROBABLY RESULT IN A SHORT DURATION PERIOD OF
MDT TO POSSIBLY HVY LAKE ENHANCED SNOW FOR NORTHWEST AND NORTHEAST
UPPER MI LATE SAT NIGHT/EARLY SUNDAY AS WIND SHIFTS NW. SINCE DEEP
LAYER FORCING WITH SHORTWAVE IS FAIRLY IMPRESSIVE...WILL NEED TO
WATCH FOR LOCALLY HVY LAKE ENHANCED SNOW OFF LAKE MI AHEAD OF WAVE
AND OFF LAKE SUPERIOR AS THE WAVE PASSES. AS WINDS VEER AROUND TO
THE N OR NE WITH SFC HIGH PRES PASSING ACROSS NRN ONTARIO...LIGHTER
LES WILL AGAIN SHIFT TO AFFECT MORE OF NRN UPPER MI SUN
AFTN/EVENING.
OVER THE LAST FEW DAYS...UNCERTAINTY FOR THE EARLY AND MIDDLE PARTS
OF NEXT WEEK HAS BEEN HIGH WITH REGARD TO TIMING/STRENGTH/TRACK OF
SEVERAL SHORTWAVES IN WNW FLOW. IT APPEARS THERE MAY BE A COUPLE OF
PERIODS OF WIDESPREAD -SN (CONFIDENCE HIGHEST FOR -SN ON MON) AS
WELL AS LAKE ENHANCEMENT OFF LAKE MICHIGAN AND LAKE SUPERIOR
DEPENDING ON WIND DIRECTION IMMEDIATELY PRIOR TO AND AFTER PASSAGE
OF THE WAVES. GIVEN THE SPREAD OF SOLUTIONS IN RECENT DAYS...
CONFIDENCE IN SNOW AND TEMP FCSTS FOR MON-WED ESPECIALLY TUE/WED
WILL BE LOW UNTIL THAT PART OF THE FCST MOVES CLOSER TO THE SHORT
TERM.
THERE ARE SOME INDICATIONS THAT A SOMEWHAT MORE MEANINGFUL LOW PRES
WAVE MAY MOVE TOWARD THE GREAT LAKES THU/FRI AS THE WRN TROF
DEVELOPS/DEEPENS AND BEGINS TO SHIFT E.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1229 AM EST FRI DEC 13 2013
CMX...EXPECT IFR VSBYS WITH FALLING SN/BLSN IN GUSTY NW FLOW EARLY
IN THE FCST PERIOD TO GIVE WAY TO MVFR CONDITIONS AS THE FLOW
WEAKENS AND VEERS TO A MORE UNFVRBL NNE DIRECTION.
IWD...AS THE FLOW VEERS TOWARD AN UPSLOPE N AND NE DIRECTION...
EXPECT LK EFFECT -SHSN TO INCRS AT IWD EARLY THIS MRNG. SO MVFR
CONDITIONS EARLY IN THE TAF PERIOD SHOULD DETERIORATE TO IFR BY
SUNRISE. AS THE LLVL WINDS VEER FURTHER TO A MORE UNFVRBL NE THEN E
DIRECTION FRI AFTN/EVNG...CONDITIONS ARE LIKELY TO IMPROVE TO MVFR
AND PERHAPS VFR BY EVNG.
SAW...EXPECT VFR CONDITIONS EARLY THIS MRNG TO DETERIORATE TO MVFR
BY SUNRISE AS THE FLOW VEERS TOWARD THE N FOLLOWING A LO PRES TROF
PASSAGE. WITH A CONTINUED VEERING TO AN UPSLOPE NNE DIRECTION THIS
AFTN...VSBYS ARE LIKELY TO FALL TO IFR WITH MORE FREQUENT ENHANCED
SHSN. AS THE FLOW VEERS FURTHER LATER THIS EVNG TOWARD A LESS FVRBL
E DIRECTION...CONDITIONS WL REBOUND TO MVFR.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 419 PM EST THU DEC 12 2013
A PERIOD OF WNW TO NW GALES IS EXPECTED LATE THIS AFTERNOON THROUGH
THIS EVENING BEFORE DIMINISHING OVERNIGHT WITH HIGH PRES BUILDING
TOWARD THE REGION. HEAVY FREEZING SPRAY WILL ALSO CONTINUE FOR MUCH
OF THE LAKE INTO THIS EVENING. WINDS WILL FINALLY DIMINISH TO
NORTHERLY AT 15 TO 25 KNOTS OVERNIGHT INTO FRIDAY MORNING AS A WEAK
RIDGE PASSES ACROSS THE LAKE. EXPECT 10 TO 20 KT WINDS TO GRADUALLY
BACK TO THE SE BY SATURDAY AHEAD OF DEVELOPING LOW PRESSURE OVER THE
UPPER MS VALLEY. DEPENDING ON THE STRENGTH OF THE LOW AS IT MOVES
ACROSS LAKE SUPERIOR ON SATURDAY NIGHT AND SUNDAY AND THE STRENGTH OF
ANOTHER LOW MOVING UP THE EAST COAST...COULD SEE AN INCREASE IN
NORTHWESTERLY WINDS ON SUNDAY TO 25 TO 30 KTS. THIS WILL BE SHORT-
LIVED AS ANOTHER HIGH SLIDES INTO THE AREA FOR THE BEGINNING OF THE
UPCOMING WORK WEEK.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
MIZ006-007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST THIS MORNING FOR
LSZ263>266.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...JLB
LONG TERM...ROLFSON
AVIATION...KC
MARINE...JLB
AREA FORECAST DISCUSSION
NWS SPRINGFIELD MO
1152 PM CST Thu Dec 12 2013
...Update to Aviation Section...
.UPDATE...
Issued at 947 PM CST THU DEC 12 2013
Near term forecast updated to account for rather wild fluctuations
in hourly temperatures. Snow cover, wind and incoming clouds will
continue to play havoc with temperatures the rest of tonight.
Concerning the forecast for tomorrow, incoming NAM and latest
RUC/HRRR suggest that precipitation onset may be delayed a few
hours Friday morning as compared to the going forecast. The very
dry 00 UTC raobs from KSGF/KLZK/KSHV/KOUN do lend credence to a
slightly slower onset. The NAM and RUC continue to be more
aggressive with the warm nose with this system versus its global
model (GFS/Euro/GEM) counterparts. With such a dry airmass in
place will come rather substantial wet bulbing potential, thus am
not buying off on the strength of the warm nose in the NAM/RUC.
Thus, other than a slight delay in onset, precipitation type
expectations have not changed. Snow, sleet and rain/freezing rain
(dependent upon surface temperatures) are all plausible Friday
and Friday night. Surface temperatures will remain very, very
tricky tomorrow. Again, wet bulbing will have a big affect on
readings through at least the morning hours. Most locations will
be a few degrees either side of the freezing mark, with localized
cooler spots in the area terrain. Full forecast update will be
provided when GFS/Euro/GEM are available for investigation.
&&
.SHORT TERM...(This Evening through Saturday)
Issued at 245 PM CST THU DEC 12 2013
A complex forecast the next 48 hours as a storm system tracks
across the region bringing a wintry mix.
A shortwave trough now over the Baja California region will track
northeast toward the Ozarks Friday. Clouds will be on the increase
later tonight as the associated moisture plume streams
northeastward.
A jet streak and accompanying lead disturbance will impact the
region beginning Friday morning. The Ozarks will become favorably
positioned within a coupled jet structure to promote strengthening
synoptic scale lift. This will result in a rapid development and
expansion of precipitation as early as day break and more so
during the morning hours Friday.
Progged low level thermal profiles suggest that precipitation
will begin as a wintry mix in the form of freezing rain and sleet.
Existing cold surfaces and potential of moderate precipitation
rates will likely lead to rapid deterioration of road conditions
Friday morning.
Temperatures will slowly rise Friday with readings rising above
the freezing mark from southwest to northeast. Most locations west
of Highway 65 will rise above freezing by midday while freezing
temperatures and wintry mix linger into at least early afternoon
east of Highway 65 into the eastern Ozarks. Just how long
temperatures remain below freezing will have to monitored closely.
The uncertainty on the exact precipitation type and duration lead
to questions on the exact amount of ice accumulation. At this time
generally expect a few hundredths to near one tenth of an inch ice
accretion.
The shortwave trough will push across the region Friday night
bringing a continuation and even an increase in precipitation
Friday evening. Meanwhile temperatures will slowly settle back
down toward freezing. Expect a wintry mix to expand across the
eastern Ozarks and also spread south across the remainder of the
area. Expect precipitation to transition to a mix of snow and sleet
before diminishing later Friday night. Light snow accumulations are
expected Friday night mainly across central Missouri and the
eastern Ozarks where an inch or two of snow accumulation is
expected.
Areas and perhaps widespread freezing drizzle is expected to develop
late Friday night into Saturday morning. This could result
hazardous travel conditions through Saturday morning.
Temperatures will rise little Saturday with all precipitation
ending during the afternoon.
With the expectation of winter precipitation a Winter Weather
Advisory will be issued from Friday morning into Friday night for
most of the Missouri Ozarks generally east of Interstate 49. The
most impacted area from this event will be along and east of the
Highway 65 corridor. Exact ice and snow accumulations remain
somewhat uncertain and the latest weather information should be
monitored.
.LONG TERM...(Saturday Night through Thursday)
Issued at 230 PM CST THU DEC 12 2013
A Canadian surface high pressure will move in for Saturday night
into early Sunday morning. Temperatures will be coldest with lows
down into the middle to upper teens especially over the higher
terrain of the Ozark Plateau and if any snow cover still remains
on the ground by that time.
Southerly to southwesterly winds will begin on Sunday on the
backside of the surface high. Sunday will remain chilly and below
average but sunny. Temperatures will rebound nicely by the early
part of next week back to more seasonable weather. The upper level
flow will try to flatten somewhat for the middle of next week.
Another weak and dry front will pass through early on Tuesday but
no real temperatures differences expected on either side of the
boundary. A dry and seasonable weather looks to stay around for
the early and middle portion of next week with possibly some
significant weather changes just beyond the 7 days toward the end
of next week.
&&
.AVIATION...(For the 06Z TAFS through 06Z Friday Night)
Issued at 1152 PM CST THU DEC 12 2013
Very messy and complex forecast for the next 24 to 36 hours.
Please refer to the short range discussion aloft for the explicit
details regarding the dynamics of this system and the temperature
profiles that will dictate a variety of precipitation types. The
forecast bottom line is that conditions will remain quiet through
tonight. Precipitation will move in from the southwest during the
daylight hours of Friday morning and continue in an on again/off
again fashion through Friday night. All precipitation types are
possible Friday...starting at a mix of freezing rain/sleet/snow
changing to rain/sleet/snow as surface temperatures rise above
freezing by a few degrees. Any flight restrictions will initially
be tied to visibility (MVFR). As the afternoon progresses,
ceilings will lower to low end MVFR. As the core of the system
passes over the region Friday night, a swath of snow will develop
over a portion of the region, with better chances of affecting
SGF/BBG. Widespread IFR visibility and ceilings are expected (LIFR
is plausible). A transition to freezing drizzle is expected just
beyond the end of the TAF cycle with IFR continuing.
&&
.SGF WATCHES/WARNINGS/ADVISORIES...
MO...WINTER WEATHER ADVISORY from 6 AM Friday to 6 AM CST Saturday
FOR MOZ055>058-066>071-077>083-089>092-094>098-102>106.
KS...NONE.
&&
$$
UPDATE...Gagan
SHORT TERM...Foster
LONG TERM...Griffin
AVIATION...Gagan
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
259 AM MST FRI DEC 13 2013
.DISCUSSION...
WATER VAPOR LOOP THIS MORNING SHOWING UPPER LOW OPENING UP OVER AZ
AS IT TRAVELS QUICKLY EAST TOWARD NM. PRECIP ACTIVITY WITH FORCING
AHEAD OF THE WAVE IS SHOWERY IN NATURE AND MOVING QUICKLY EAST INTO
THE RIO GRANDE VALLEY. LIGHT SNOW ACCUMS WILL OCCUR IN BRIEF BOUTS
OF CONVECTIVE ACTIVITY. THE EXCEPTION WILL BE WEST FACING SLOPES OF
THE CENTRAL MT CHAIN WHERE ENHANCED UPSLOPE WILL SQUEEZE OUT MORE
STRATIFORM ACTIVITY FOR SEVERAL HOURS THIS MORNING...EQUATING TO
PERHAPS AN INCH OR TWO ABOVE 7500 FT. THE HRRR ENSEMBLE REFLECTIVITY
PRODUCT IS HANDLING THE CURRENT DISTRIBUTION OF PRECIP WELL SO LEFT
POPS THIS MORNING AROUND THE ABQ METRO AREA AND SURROUNDING HIGH
TERRAIN IN THE MODERATE TO HIGH CHANCE RANGE.
THE MAIN STORY TODAY WILL BE WINDS ALONG AND EAST OF THE CENTRAL MT
CHAIN WHERE FAST LAMINAR FLOW WITHIN THE EXITING UPPER TROUGH WILL
COMBINE WITH A DEEPENING SURFACE LOW OVER THE PLAINS. SPC WRF-ARW
INDICATES 850-700MB LAYER WINDS OF 30-35KTS STRETCHING DOWN THE U.S.
285 CORRIDOR FROM CLINES TO VAUGHN...ALONG 54 NEAR CORONA...AND MUCH
OF LINCOLN AND WESTERN CHAVES COUNTIES. WINDS WILL INCREASE THRU THE
MORNING AND PEAK NEAR 2 PM THEN TAPER OFF BY SUNSET.
A RATHER STOUT UPPER WAVE IN NW FLOW WILL SHIFT QUICKLY OVER THE
AREA BEHIND THIS DEPARTING WAVE AND DELIVER ANOTHER PUNCH OF COLDER
AIR FOR SATURDAY. HIGHS WILL BE ROUGHLY 5 TO 10F BLW NORMAL. TEMPS
WILL MODERATE BACK TO NEAR NORMAL SUNDAY AND CONTINUE WARMING THRU
MID WEEK AS UPPER FLOW BACKS MORE ZONAL. MODELS ARE STILL CLOSING IN
ON A WHOPPER OF A STORM FOR LATE IN THE WEEK WITH ANOTHER SURGE OF
BITTER COLD AIR...SNOW...AND STRONG WINDS.
GUYER
&&
.FIRE WEATHER...
AS EXPECTED THE BAJA LOW APPROACHING FROM THE WEST SOUTHWEST IS
WEAKENING INTO AN OPEN TROUGH AND WILL PASS EASTWARD OVER THE FIRE
WEATHER FORECAST AREA TODAY. MAINLY SCATTERED SNOW SHOWERS ARE EXPECTED
THIS MORNING ALONG AND WEST OF THE CENTRAL MOUNTAIN CHAIN. THIS
AFTERNOON THE BASE OF THE TROUGH WILL BE EXITING...BUT ANOTHER UPPER
TROUGH WILL DROP SOUTHEASTWARD TOWARD NM QUICKLY ON THE HEELS OF THE
FIRST SYSTEM. THIS WILL KEEP ISOLATED RAIN AND SNOW SHOWERS IN THE
FORECAST MAINLY FROM THE CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAIN
CHAIN THROUGH THE AFTERNOON.
BETWEEN THE TWO UPPER TROUGHS A NORTHWESTERLY 700 MB WIND SPEED
MAXIMUM WILL DEVELOP ALONG THE CONTINENTAL DIVIDE AND CENTRAL
MOUNTAIN CHAIN...ESPECIALLY SOUTH OF THE NORTHERN MOUNTAINS...WITH
SPEEDS PEAKING AROUND 30-45 KTS DURING THE EARLY TO MID AFTERNOON.
AT THE SURFACE A 1007 MB SURFACE LOW IN SE CO WILL SINK
SOUTHEASTWARD ACROSS THE TX PANHANDLE TODAY...KEEPING THE SURFACE
PRESSURE GRADIENT TIGHT ALONG AND EAST OF THE CENTRAL MOUNTAINS. NW
WIND GUSTS IN THE 30 TO 40 MPH RANGE WILL BE COMMON IN THE W CENTRAL
AND SW MOUNTAINS TODAY...WITH GUSTS FROM 40 TO 50 MPH ALONG AND EAST
OF THE CENTRAL MOUNTAINS TO THE PECOS RIVER VALLEY. AS A RESULT OF
THE STRONGER WINDS...GOOD TO EXCELLENT VENTILATION ARE EXPECTED
MAINLY SOUTH OF I-40 TODAY WITH BROAD POCKETS OF POOR VENTILATION
ACROSS THE NORTH.
TROUGHING IN NW FLOW ALOFT AND COLD AIR ADVECTION AT THE SURFACE
WILL LINGER OVER NM THROUGH SATURDAY. COOLING THAT BEGINS ACROSS
NORTHERN AND WESTERN AREAS TODAY WILL SPREAD TO INCLUDE SOUTHEAST
AREAS ON SATURDAY. HIGH TEMPERATURES SATURDAY WILL BE A FEW TO 10
DEGREES BELOW TODAYS READINGS. VENT RATES SHOULD PLUMMET IN MOST
LOCATIONS SATURDAY...EXCEPT ACROSS THE FAR EASTERN PLAINS WHERE GOOD
OR BETTER VENTILATION IS EXPECTED DUE TO PERSISTENT NORTH WINDS.
UNDER NW FLOW ALOFT DRY WEATHER IS EXPECTED SATURDAY THROUGH THE
MIDDLE OF THE COMING WORK WEEK WITH HUMIDITIES TRENDING DOWNWARD
EACH DAY THROUGH TUESDAY BEFORE THEY STABILIZE. TEMPERATURES WILL
TREND UPWARD THROUGH TUESDAY AS WELL WITH HIGHS REACHING ABOVE
NORMAL AREAWIDE BEGINNING MONDAY. AFTER GENERALLY POOR VENTILATION
SUNDAY THROUGH WEDNESDAY...VENT RATES SHOULD BEGIN TO IMPROVE ON
THURSDAY AS AN UPPER TROUGH DIGS INTO THE WESTERN US AND SW FLOW
ALOFT BEGINS TO STRENGTHEN OVER NM. SW WINDS SHOULD ALSO BEGIN TO
STRENGTHEN THURSDAY ACROSS WESTERN AND EAST CENTRAL PARTS OF THE
FORECAST AREA.
44
&&
.AVIATION...
06Z TAF CYCLE
STORM CENTER OVER CENTRAL ARIZONA MOVING TO SOUTHERN OKLA BY 00Z
FRI AFTERNOON...AS NEXT INBOUND SYSTEM AMPLIFIES OVER THE FOUR
CORNERS BY 06Z FRIDAY EVENING. MT OBSCURATION AND CIGS DOWN TO
MVFR THRESHOLDS IN SHOWERS AND A FEW EMBEDDED THUNDERSTORMS
ACROSS MUCH OF WESTERN AND CENTRAL NEW MEXICO. THUNDER WILL BE
MOST LIKELY FROM THE CONTINENTAL DIVIDE TO THE ARIZONA LINE FROM
09Z ONWARD...WITH LESS LIKELY ACTIVITY OVER THE RIO GRANDE VALLEY
BY 10Z THIS EVENING. ACTIVITY WILL TAPER OFF RAPIDLY AFTER FRIDAY
SUNRISE...AND END BY 18Z LATE FRIDAY MORNING AS WEATHER SYSTEM
CROSSES OUT OF EASTERN NEW MEXICO INTO THE TX PANHANDLE. SOME
LINGERING CLOUD NEAR THE ARIZONA LINE FOR MT TOP OBSCURATION AND
CIGS AOA BKN/OVC040 CONTG THROUGH 06Z AND BEYOND...WITH CLEAR
SKIES ELSEWHERE. IN TAFS...SCT GROUPS AT IFR AND MVFR LEVELS
SIGNALING MOST LIKELY WINDOW FOR REDUCED FLIGHT
CATEGORIES...WHILE VCSH SET FOR MOST LIKELY ONSET OF RAIN CHANGING
RAPIDLY TO LIGHT SNOW. HAVE SET VCTS AT GUP TO COVER NEARBY
THUNDER THROUGH 09Z THIS EVENING.
SHY
&&
.PRELIMINARY POINT TEMPS/POPS...
FARMINGTON...................... 36 13 35 13 / 5 0 0 0
DULCE........................... 35 4 34 2 / 10 5 0 0
CUBA............................ 38 15 36 14 / 30 5 0 0
GALLUP.......................... 40 11 37 10 / 10 0 0 0
EL MORRO........................ 38 14 37 10 / 30 0 0 0
GRANTS.......................... 43 16 39 13 / 30 0 0 0
QUEMADO......................... 45 20 40 18 / 30 0 0 0
GLENWOOD........................ 54 22 52 19 / 20 0 0 0
CHAMA........................... 34 9 32 9 / 20 10 0 0
LOS ALAMOS...................... 41 18 36 16 / 30 5 0 0
PECOS........................... 38 18 35 20 / 20 5 0 0
CERRO/QUESTA.................... 34 4 30 4 / 30 5 0 0
RED RIVER....................... 34 10 28 8 / 30 10 5 0
ANGEL FIRE...................... 38 9 32 8 / 20 10 5 0
TAOS............................ 37 7 34 5 / 30 5 0 0
MORA............................ 41 16 36 16 / 10 5 0 0
ESPANOLA........................ 43 18 37 16 / 20 0 0 0
SANTA FE........................ 35 19 34 19 / 40 5 0 0
SANTA FE AIRPORT................ 39 17 36 17 / 30 0 0 0
ALBUQUERQUE FOOTHILLS........... 41 24 40 23 / 40 0 0 0
ALBUQUERQUE HEIGHTS............. 43 25 42 22 / 40 0 0 0
ALBUQUERQUE VALLEY.............. 45 23 44 21 / 30 0 0 0
ALBUQUERQUE WEST MESA........... 44 25 44 23 / 40 0 0 0
LOS LUNAS....................... 46 22 44 20 / 40 0 0 0
RIO RANCHO...................... 43 24 43 22 / 30 0 0 0
SOCORRO......................... 55 26 47 23 / 30 0 0 0
SANDIA PARK/CEDAR CREST......... 38 19 38 18 / 50 0 0 0
TIJERAS......................... 40 22 40 21 / 40 0 0 0
MORIARTY/ESTANCIA............... 38 11 37 11 / 20 0 0 0
CLINES CORNERS.................. 36 17 35 18 / 20 0 0 0
GRAN QUIVIRA.................... 44 22 40 21 / 30 0 0 0
CARRIZOZO....................... 47 26 45 22 / 20 0 0 0
RUIDOSO......................... 46 24 41 23 / 20 0 0 0
CAPULIN......................... 42 17 35 17 / 5 5 0 0
RATON........................... 49 18 40 16 / 5 5 0 0
SPRINGER........................ 48 17 41 16 / 5 5 0 0
LAS VEGAS....................... 44 17 37 19 / 10 5 0 0
CLAYTON......................... 52 22 44 26 / 5 5 0 0
ROY............................. 48 22 40 22 / 5 5 0 0
CONCHAS......................... 58 28 47 26 / 0 0 0 0
SANTA ROSA...................... 52 25 47 25 / 5 0 0 0
TUCUMCARI....................... 59 27 49 26 / 0 0 0 0
CLOVIS.......................... 55 25 46 26 / 5 0 0 0
PORTALES........................ 57 26 47 25 / 5 0 0 0
FORT SUMNER..................... 56 27 49 26 / 5 0 0 0
ROSWELL......................... 61 29 50 24 / 5 0 0 0
PICACHO......................... 55 27 45 23 / 5 0 0 0
ELK............................. 52 27 43 25 / 10 0 0 0
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM THIS MORNING TO 4 PM MST THIS AFTERNOON
FOR THE FOLLOWING ZONES...NMZ521>524-526-533-537>539.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
1131 PM CST THU DEC 12 2013
.UPDATE...
ISSUED AT 1131 PM CST THU DEC 12 2013
SNOW BAND CONTINUES FROM THE NORTHWEST CWA INTO THE GFK
AREA...WITH VIS AROUND 2 TO 4 MILES. ACCUMULATIONS SHOULD REMAIN
AROUND AN INCH OR MAYBE TWO. COLD AIR CONTINUES TO MOVE DOWN FROM
THE NORTH AND WIND CHILLS IN THE NORTHERN TIER HAVE STARTED TO
DROP TO CRITERIA. WILL MAINTAIN HEADLINE.
UPDATE ISSUED AT 929 PM CST THU DEC 12 2013
SNOW BAND HAS STARTED TO DEVELOP...BUT HAS BEEN A BIT FURTHER
SOUTH THAN ORIGINALLY EXPECTED AND SOME FLAKES HAVE ALREADY BEEN
REPORTED AT COOPERSTOWN AND VALLEY CITY ALTHOUGH NOT CONSISTENTLY.
BROUGHT POPS A BIT FURTHER SOUTH FOR TONIGHT AND MADE SOME FURTHER
ADJUSTMENTS TO QPF AS NOT MUCH WILL ACCUMULATE BEFORE MIDNIGHT.
TEMPS STILL SEEM ON TRACK TO DROP DOWN SIGNIFICANTLY LATER
TONIGHT...AND WINDS WILL STAY NORTH TO NORTHEASTERLY AT AROUND 10
TO 15 MPH. WILL CONTINUE TO KEEP THE WIND CHILL HEADLINE THAT WE
HAVE GOING.
UPDATE ISSUED AT 635 PM CST THU DEC 12 2013
THERE HAS BEEN A BREAK IN THE SNOW EARLY THIS EVENING...BUT
SHORT RANGE MODELS HAVE THE SNOW BAND REDEVELOPING IN THE DEVILS
LAKE BASIN SOON...SO KEPT POPS THAT RAMP UP IN THE NEXT FEW HOURS
GOING. DID CUT AMOUNTS TOWARDS THE SOUTH AND EAST THOUGH. TEMPS
CONTINUE TO BE ON TRACK SO WILL KEEP LOWS IN THE TEENS BELOW ZERO
UP NORTH TO NEAR ZERO IN THE SOUTH.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 330 PM CST THU DEC 12 2013
MAIN FORECAST CONCERNS IN THE SHORT TERM WILL BE EXTENT OF LIGHT
SNOW WITH PASSING UPPER WAVES AND TEMP TRENDS...WITH COLD AIR
REMAINING FIRMLY ENTRENCHED.
A NARROW BAND OF LIGHT SNOW HAS PROGRESSED FROM THE NORTHERN
VALLEY SOUTHEASTWARD INTO NW MINNESOTA THIS AFTERNOON. THIS WILL
CONTINUE TO SHIFT SOUTHEASTWARD THROUGH THE REST OF THE AFTERNOON.
ANOTHER AREA OF LIGHT SNOW WILL SHIFT INTO THE DEVILS LAKE BASIN
THIS EVENING AND SOUTHEASTWARD OVERNIGHT...IN ASSOCIATION WITH AN
AREA OF MID-LEVEL FRONTOGENESIS AND SYNOPTIC FORCING IN THE RIGHT
ENTRANCE REGION OF A BROAD UPPER JET. AS THE FORCING GRADUALLY
WEAKENS...A DECREASING TREND IN THE SNOWFALL IS EXPECTED WITH TIME
AS THE SNOW SHIFTS SOUTHWARD. RIGHT NOW THE BEST CHANCE FOR 1 TO 3
INCHES OF ACCUMULATION LOOKS TO BE FROM THE DEVILS LAKE AREA INTO
PARTS OF THE NORTHERN AND CENTRAL VALLEY TONIGHT INTO FRIDAY.
TEMPS TONIGHT MAY BE TRICKY. ALTHOUGH LOW-LEVEL COLD ADVECTION
WILL CONTINUE THROUGH THE NIGHT...HOW MUCH TEMPS FALL WILL DEPEND
ON CLOUD COVERAGE. THE RAP BRINGS SOME LOW-LEVEL DRYING INTO PARTS
OF NORTHWEST MINNESOTA OVERNIGHT. TEMPS COULD DROP PRETTY QUICKLY
IF ANY CLEARING DOES OCCUR...AND THUS HAVE THE LOWEST TEMPS IN
THIS AREA OF NW MINNESOTA. HIGHS ON FRIDAY LIKELY WILL BE COLDEST
NORTH...WITH TEMPS REMAINING BELOW ZERO...AND SINGLE DIGITS ABOVE
ZERO FARTHER SOUTH.
AS WINDS ARE EXPECTED TO STAY UP AROUND 10 KTS OVERNIGHT...WILL
ALSO ISSUE A WIND CHILL ADVISORY FOR MUCH OF NE ND EASTWARD INTO
NW MN FROM 06Z TONIGHT THROUGH 03Z SATURDAY. WITH WINDS BRISK FROM
THE NORTHEAST ON FRIDAY AHEAD OF THE SFC HIGH...HELD ONTO THE
ADVISORY UNTIL FRIDAY EVENING...ALTHOUGH WIND CHILLS MAY RISE ABOVE
CRITERIA FOR A BIT DURING THE DAY. AS THE SFC RIDGE AXIS
APPROACHES FRIDAY NIGHT...WINDS MAY GO LIGHT...ALLOWING FOR WIND
CHILLS TO RISE ABOVE ADVISORY THRESHOLD. THIS WILL BE MONITORED
DURING FUTURE SHIFTS THOUGH.
A SERIES OF UPPER IMPULSES EMBEDDED IN NORTHWEST FLOW ALOFT WILL
CONTINUE TO AFFECT THE AREA FRIDAY NIGHT INTO SATURDAY...BRINGING
CONTINUED CHANCES FOR LIGHT SNOW. ALTHOUGH MODEL QPF IS LOW...WITH
HIGH SNOW RATIOS AND MODEL SOUNDINGS INDICATING A FAIRLY DEEP
SATURATED LAYER...A FLUFFY INCH OR TWO OF SNOW IS
POSSIBLE...DEPENDING ON THE EXACT TRACK OF THE IMPULSES.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 330 PM CST THU DEC 12 2013
TEMPS ON SATURDAY WILL RISE INTO THE SINGLE DIGITS EITHER SIDE OF
ZERO WITH LIGHT SNOW REMAINING POSSIBLE AS UPPER LEVEL ENERGY
CASCADES THROUGH THE FLOW. A SFC RIDGE WILL SPREAD OVER THE AREA
ON SATURDAY NIGHT. THE MAIN QUESTION WILL BE TEMPS...WHICH WILL BE
DEPENDENT ON CLOUD COVER. THUS...TEMPS COULD BE A BIT COLDER IF
SKIES DO CLEAR.
ANOTHER ROUND OF LIGHT SNOW IS POSSIBLE SUNDAY AS WARM AIR ADVECTION
DEVELOPS AND THE LOW-LEVEL BAROCLINIC ZONE APPROACHES FROM THE WEST
AHEAD OF THE NEXT UPPER WAVE. HOWEVER...TEMPS WILL REMAIN WELL
BELOW NORMAL.
FOR THE SUNDAY NIGHT THROUGH THURSDAY PERIOD...12Z ECMWF/GFS/GEM SO
ENOUGH DISAGREEMENT IN TIMING AND LOCATION OF SEVERAL 500 MB SHORT
WAVES/SURFACE LOW PRESSURE SYSTEMS TO KEEP CONFIDENCE IN FCST A BIT
LOWER THAN NORMAL. IDEA IS FOR ONE SHORT WAVE MONDAY TO EXIT
FOLLOWED BY SOME COLDER AIR MON NIGHT-TUE THEN THE NEXT ONE DUE WED
NIGHT-THU TIME FRAME. EXACT PLACEMENT OF LOWS WILL MEAN POTENTIAL
TEMP DIFFERENCES WITH OVERALL 12Z EURO AND GEM A BIT WARMER THAN 12Z
GFS ESP FOR MID WEEK SYSTEM. WITH THE DIFFERENCES STUCK WITH ALL
BLEND GUIDANCE. THERAFTER AND BEYOND THIS PERIOD IS WHEN THE NEXT
ARCTIC OUBREAK WILL OCCUR.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z FRIDAY NIGHT)
ISSUED AT 1131 PM CST THU DEC 12 2013
CIGS CONTINUE BETWEEN LOW VFR AND MVFR...WITH THE BAND OF LIGHT
SNOW BRINGING VIS AT KDVL AND KGFK TO 3SM...EVEN 2SM AT TIMES.
THINK THAT THE VIS WILL STAY AT OR ABOVE THESE LEVELS AND
CONDITIONS WILL BE MOSTLY MVFR THROUGH MOST OF THE NIGHT. NORTH TO
NORTHEAST WINDS WILL CONTINUE BETWEEN 10 AND 15 KTS. CONDITIONS
SHOULD IMPROVE TO VFR TOWARDS THE END OF THE PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WIND CHILL ADVISORY UNTIL 9 PM CST FRIDAY FOR NDZ006>008-014>016-
024-026>030-054.
MN...WIND CHILL ADVISORY UNTIL 9 PM CST FRIDAY FOR MNZ001-002-004>009-
013>017-022-023.
&&
$$
UPDATE...JR
SHORT TERM...MAKOWSKI
LONG TERM...RIDDLE
AVIATION...JR
AREA FORECAST DISCUSSION
NWS TULSA OK
1059 PM CST THU DEC 12 2013
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM.
FOR THE 6Z TAFS... LIGHT RAIN WILL MOVE INTO THE AREA BY AS EARLY
AS ABOUT 9Z. TEMPERATURES ARE WARMING OVERNIGHT AND ARE NOW ABOVE
FREEZING AT ALL SITES EXCEPT KXNA AND KFSM. THESE SITES WILL WARM
ABOVE FREEZING BY ABOUT THE TIME RAINFALL BEGINS. WILL NOT INCLUDE
FZRA IN ANY TAFS... BUT IT COULD BE A REMOTE POSSIBILITY FOR A
SHORT TIME AFTER RAINFALL BEGINS. CEILINGS AT ALL SITES ARE
EXPECTED TO GRADUALLY FALL TO MVFR LEVELS DURING THE DAY FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 935 PM CST THU DEC 12 2013/
..UPDATE...
DISCUSSION...
QUIET WEATHER SO FAR ACROSS THE REGION THIS
EVENING...ALTHOUGH RADAR ECHOES ACROSS SW OK
CONTINUE TO ADVANCE SLOWLY ENE. HRRR OUTPUT HAS
BEEN VERY CONSISTENT OVER THE PAST SEVERAL HOURS
BRINGING LIGHT PRECIP INTO ERN TOWARD 06Z...AND
EVENTUALLY INTO NW AR 09-12Z. BASED ON THIS AND
CURRENT TRENDS...HAVE UPPED POPS SOME LATER TONIGHT
AND BROUGHT PRECIP INTO NW AR A BIT QUICKER THAN
PREVIOUSLY THOUGHT.
SURFACE TEMPS ALREADY RUNNING AT OR JUST A BIT
BELOW FREEZING ACROSS FAR ERN OK/NW AR...SO ONSET
OF PRECIP IN THESE AREAS WILL LIKELY BE LIGHT
FREEZING RAIN. TOUGHER CALL ON PRECIP TYPE TOWARD
12Z-15Z AS SOUTH WINDS CONTINUE TO INCREASE ALONG
WITH SLOWLY RISING SFC TEMPS.
UPDATE PRODUCTS WILL BE OUT SHORTLY.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...NONE.
AR...NONE.
&&
$$
AVIATION...06
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1200 AM CST FRI DEC 13 2013
.AVIATION...
CIGS WILL BE SLIGHTLY LOWER THAN EARLIER FORECASTED DURING PARTS
OF THE 13/06Z TAF PERIOD. VFR CIGS BKN-0VC035-050 WILL SPREAD
ACROSS THE REMAINDER OF SOUTH CENTRAL TEXAS IN THE NEXT COUPLE OF
HOURS. MVFR CIGS/VSBYS AND ISOLD SHRA WILL DEVELOP OVER THE HILL
COUNTRY DURING THE OVERNIGHT HOURS AND SPREAD ACROSS THE REMAINDER
OF SOUTH CENTRAL TEXAS FRIDAY MORNING. SHRA WILL BECOME A LITTLE
MORE NUMEROUS EAST OF A KJCT TO KHDO TO KPEZ LINE ON FRIDAY AS AN
UPPER LEVEL TROUGH MOVES ACROSS TEXAS. HAVE MAINTAINED PROB30S FOR
THE I-35 TAF SITES FROM MID MORNING TO MID AFTERNOON. THE TROUGH
ALONG WITH THE SHOWERS AND CLOUDS MOVES OFF TO THE EAST FRIDAY
EVENING LEADING TO VFR SKIES OUT WEST IN LATE AFTERNOON AND IN
THE EAST DURING THE EVENING. S TO SE WINDS 4 TO 10 KTS WILL BECOME
SW FRIDAY EVENING AND W FRIDAY NIGHT.
&&
.PREV DISCUSSION... /ISSUED 600 PM CST THU DEC 12 2013/
AVIATION...
VFR SKIES WILL PREVAIL THROUGH THE 13/00Z TAF PERIOD. CIGS AT
BKN-OVC035-050 DEVELOPING ACROSS THE AREA THIS EVENING WITH ISOLD
SHRA DEVELOPING MAINLY OVER THE HILL COUNTRY OVERNIGHT N-NW OF TAF
SITES AS AN UPPER LEVEL TROUGH APPROACHES. ISOLD TO SCT SHRA CAN
BE EXPECTED FRIDAY AS THE UPPER LEVEL TROUGH MOVES ACROSS THE AREA
WITH TEMPO MVFR CIGS/VSBYS. WILL MAINTAIN MENTION AT THE I-35 TAF
SITES. UPPER LEVEL TROUGH MOVES EAST LEADING TO CLEARING SKIES
FRIDAY AFTERNOON WEST AND EVENING EAST. WINDS WILL BECOME S-SE AT
4 TO 8 KTS AT TAF SITES TONIGHT...THEN TURN TO SW FRIDAY EVENING.
PREV DISCUSSION... /ISSUED 300 PM CST THU DEC 12 2013/
SHORT TERM (TONIGHT THROUGH FRIDAY NIGHT)...
MID TO UPPER LEVEL CLOUDS ARE COVERING ALL OF SOUTH CENTRAL TEXAS
THIS AFTERNOON AS SOUTHWEST FLOW ALOFT PUSHES MOISTURE ACROSS THE
AREA. THESE CLOUDS WILL LINGER AROUND THROUGH FRIDAY AS AN UPPER
LEVEL TROUGH TRAVELS FROM THE DESERT SOUTHWEST INTO THE SOUTHERN
PLAINS. AT LOWER LEVELS...VISIBLE SATELLITE IMAGES ARE DEPICTING
BROKEN TO OVERCAST SKIES PUSHING TO THE NORTH-NORTHEAST ACROSS THE RIO
GRANDE VALLEY WHILE SPREADING NORTHEASTWARD TOWARD THE SAN ANTONIO
AREA. LATEST RUC SOLUTION HAS THIS LOW LEVEL CLOUD DECK SPREADING
ACROSS MOST AREAS OF SOUTH CENTRAL TEXAS BY MIDNIGHT. OVERNIGHT
LOWS WILL RANGE FROM THE MID TO UPPER 30S HILL COUNTRY TO LOWER
40S REST OF THE AREA. LATE TONIGHT INTO FRIDAY...CHANCES OF RAIN
WILL BE INCREASING AS THE UPPER LEVEL TROUGH ABOVE MENTIONED NEARS
THE SOUTHERN PLAINS. EXPECT SHOWERS TO AFFECT THE NORTHWEST AND
NORTHERN SECTIONS OF SOUTH CENTRAL TEXAS OVERNIGHT WITH SHOWERS
SPREADING EASTWARD ON FRIDAY. RAIN CHANCES WILL COME TO AN END
LATE FRIDAY AS THE UPPER TROUGH PUSHES TO THE EAST. RAINFALL
AMOUNTS WILL GENERALLY BE FROM A FEW HUNDREDTHS TO ONE QUARTER
INCH...ESPECIALLY ACROSS THE NORTHEAST PART OF THE HILL COUNTRY.
LONG TERM (SATURDAY THROUGH THURSDAY)...
A DRY COLD FRONT IS EXPECTED TO PUSH ACROSS SOUTH CENTRAL TEXAS
ON SATURDAY WITH SKIES CLEARING FROM WEST TO EAST BY THE AFTERNOON.
MODERATE NORTHWESTERLY WINDS ARE EXPECTED IN THE WAKE OF THE FRONT
WITH WIND SPEEDS DECREASING LATE SATURDAY INTO SUNDAY. SEVERAL
COOL NIGHTS ARE EXPECTED IN THE WAKE OF THE FRONTAL PASSAGE WITH
OVERNIGHT LOWS IN THE LOWER 30S OVER THE HILL COUNTRY AND MID 30S
REST OF THE AREA ON SUNDAY WITH SIMILAR LOWS MONDAY MORNING.
A NORTHWEST TO ZONAL FLOW ALOFT IS ANTICIPATED FOR MUCH OF NEXT
WEEK WITH DRY AND WARMING WEATHER CONDITIONS IN STORE THROUGH
THURSDAY OF NEXT WEEK. LATEST GFS AND ECMWF SOLUTIONS CONTINUE TO
SHOW ANOTHER ARCTIC AIRMASS ARRIVING TO THE LOCAL AREA BETWEEN
SATURDAY AND SUNDAY...DECEMBER 21 AND 22.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 56 44 55 33 / 10 40 20 10 -
AUSTIN BERGSTROM INTL AIRPORT 37 58 42 56 32 / 10 40 20 10 -
NEW BRAUNFELS MUNI AIRPORT 40 58 44 57 33 / 10 30 20 10 -
BURNET MUNI AIRPORT 37 56 40 52 30 / 20 40 10 - -
DEL RIO INTL AIRPORT 40 63 41 60 34 / 10 10 - 0 -
GEORGETOWN MUNI AIRPORT 37 56 42 52 31 / 20 40 20 10 -
HONDO MUNI AIRPORT 40 60 43 61 32 / 10 30 10 - -
SAN MARCOS MUNI AIRPORT 39 59 44 57 33 / 10 40 20 10 -
LA GRANGE - FAYETTE REGIONAL 41 60 47 57 33 / 10 40 30 10 -
SAN ANTONIO INTL AIRPORT 41 58 45 59 34 / 10 30 20 - -
STINSON MUNI AIRPORT 43 60 46 61 35 / 10 30 20 10 -
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS ALBANY NY
628 AM EST FRI DEC 13 2013
.SYNOPSIS...
AN ARCTIC FRONTAL BOUNDARY WILL GRADUALLY SLIDE ACROSS THE REGION
TODAY. IN ITS WAKE...HIGH PRESSURE WILL ATTEMPT TO BUILD OVER
THE NORTHERN HALF OF THE REGION TONIGHT. A WINTER STORM WILL TAKE
SHAPE AND IMPACT THE REGION THIS WEEKEND WITH MODERATE TO
SIGNIFICANT AMOUNTS OF SNOW.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 600 AM EST...
LITTLE CHANGE TO THE ONGOING FORECAST AS LAKE BAND WAS A BIT
DELAYED WITH THE TRACK FURTHER SOUTH BUT WILL DO SO IN A COUPLE OF
HOURS. INLAND EXTENT REMAINS AROUND 60 MILES WHICH IS STILL IN
EXCELLENT AGREEMENT WITH LOCAL EXPERIMENTAL PROGRAM. DID TWEAK
TEMPS AS VALUES HAVE INCREASED A BIT DUE TO THE CLOUD COVER AND
BEFORE THE ARCTIC FRONT FROPA.
AS OF 300 AM EST...
THE INITIAL CONCERN THIS MORNING IS THE ONGOING LAKE EFFECT
ACTIVITY DOWNWIND OF LAKE ONTARIO. KTYX DOPPLER RADAR SUGGESTS THE
INLAND EXTENT OF THE >20DBZ WAS ACROSS NORTH CENTRAL HERKIMER
COUNTY AROUND 60 MILES INLAND FROM THE LAKE. THIS IS IN EXCELLENT
AGREEMENT WITH THE LOCALLY DEVELOPED CSTAR RESEARCH OF LAKE EFFECT
INLAND EXTENT PROGRAM WHICH KEEPS THIS BAND AROUND THAT 60 MILE
INLAND PENETRATION THROUGH THE REMAINDER OF THIS EARLY FRIDAY
MORNING. AFTER SUNRISE...THE ARCTIC FRONTAL BOUNDARY IS EXPECTED
TO SLIDE TOWARD THE I90 CORRIDOR WHICH WILL SHIFT THE BOUNDARY
LAYER WIND TOWARD A WEST-NORTHWEST THEN NORTHWEST WHICH WILL TAKE
THIS BAND SOUTHWARD. MAIN QUESTION WILL BE HOW MUCH THIS FRONT
WILL INTERACT WITH THE MOISTURE AND TRANSPORT IT DOWNSTREAM INTO
THE MOHAWK VALLEY AND THE CAPITAL REGION. LOCALLY DEVELOP HIRESWRF
AND HRRR REFLECTIVITY FORECASTS SUGGEST A FEW SNOW SHOWERS AND
SQUALLS MAY MAKE IT INTO THESE REGIONS AS WE WILL PLACE A LITTLE
HIGHER POPS THROUGH THE MORNING HOURS. AS THE FLOW CONTINUES TO
BACK IN THE WAKE OF THE FROPA...THIS BAND WILL WEAKEN AS FLOW
TRAJECTORY BECOMES LESS THAN FAVORABLE FOR OUR REGION AND LOWERING
SUBSIDENCE INVERSION AS SURFACE HIGH BUILDS NORTH OF THE GREAT
LAKES REGION AND EXTENDS ITS INFLUENCE OVER LAKE ONTARIO.
CLOUDS WILL BE A CHALLENGE TODAY AS 1000-850MB RH VALUES FROM THE
LATEST RUC13 CONTINUE TO SUPPORT RATHER HIGH VALUES FOR THE
SOUTHERN 2/3RDS OF THE CWA. HOWEVER...THE LOW LEVEL AGEOSTROPHIC
FLOW DOES INCREASE A BIT WHICH SHOULD ASSIST WITH THE DRIER AIR
AND EVENTUAL MECHANICAL MIXING FOR SOME BREAKS TO OCCUR INTO THE
CAPITAL REGION LATER THIS AFTERNOON. THE COLD ADVECTION TODAY
ALONG WITH THE CLOUD COVER AND A VERY LOW SUN ANGLE SHOULD KEEP
AFTERNOON HIGHS RATHER CHILLY INTO THE TEENS FOR THE TERRAIN AND
20S ELSEWHERE AS H850 TEMPS DROP BACK WELL INTO THE NEGATIVE TEENS
AND AROUND -20C FOR THE DACKS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
WINTER STORM WATCH FOR THE ENTIRE REGION...
EXTENSIVE COLLABORATION WITH NEIGHBORING WFOS AND WPC THIS MORNING
AS 00Z GUIDANCE IS SLOWLY COMING TO AN AGREEMENT WITH A
SIGNIFICANT IMPACT FROM THIS DEVELOPING WINTER STORM. THIS STORM
IS MORE OF A MILLER TYPE `B` AS REDEVELOPMENT WILL COMMENCE FROM
THE OHIO VALLEY SYSTEM TO THE MID ATLANTIC REGION.
THE MAIN PLAYER WITH THIS UPCOMING EVENT WAS SITUATED OVER THE
FOUR CORNERS REGION PER THE H2O VAPOR LOOP ANALYSIS.
MEANWHILE...PACIFIC MOISTURE WAS ADVANCING AHEAD OF THIS SYSTEM
ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY. A
POTENT UPPER JET WAS DIVING INTO THE NORTHERN TIER OF THE CONUS AS
THESE SYSTEMS WILL ATTEMPT TO PHASE OVER THE MID ATLANTIC INTO THE
NORTHEAST CORRIDOR ON SATURDAY.
THE AFOREMENTIONED ARCTIC FRONTAL BOUNDARY WILL BECOME QUASI-
STATIONARY ALONG OR JUST SOUTH OF THE NY STATE LINE TONIGHT WITH
BROAD ISENTROPIC LIFT EVOLVING OVER WESTERN AND CENTRAL NY. THIS
WILL SPELL OUT LIGHT SNOW DEVELOPING FROM WEST TO EAST AND COULD
EXTEND AS FAR EAST AS THE CATSKILLS OVERNIGHT. FOR THE REMAINDER
OF THE REGION...EXPECTING A MAINLY DRY OVERNIGHT AS THAT ARCTIC
DRY AIRMASS ADVECTS SOUTHWARD THROUGH THE HUDSON RIVER VALLEY.
OVERNIGHT LOWS WILL DROP WELL BELOW ZERO ACROSS THE DACKS WHERE
THE BETTER CHANCE FOR CLEARING SKIES AND TEENS ELSEWHERE AS THE
H850 TEMPS DROP TO BELOW -20C ACROSS THE NORTH AND NEGATIVE MID
TEENS ELSEWHERE.
IN FACT...THIS AGEOSTROPIC LOW LEVEL COMPONENT WHILE WEAK IN
MAGNITUDE IS RATHER PERSISTENT THROUGH THE DAY SATURDAY INTO
SATURDAY EVENING. THIS WILL KEEP THE PRECIP ALL SNOW AS ISENTROPIC
LIFT INCREASES AND LIGHT SNOW SPREADS ACROSS MOST THE REGION FROM
SOUTH TO NORTH THROUGH THE DAY. ACCUMULATIONS DURING SATURDAY WILL
LIKELY RANGE FROM AROUND 1 INCH ACROSS THE NORTHERN PORTIONS OF
THE REGION WITH AROUND 3 INCHES FOR THE SOUTH AND SOUTHWEST
PORTIONS OF THE REGION. HIGH TEMPERATURES WILL STRUGGLE TO GET OUT
OF THE TEENS.
SATURDAY NIGHT...THIS WILL BE THE MAIN EVENT FOR THE REGION AS
INCREASING LOW LEVEL SOUTH-SOUTHEAST JET GREATER THAN 50KTS
DEVELOPS AS SECONDARY DEVELOPMENT OF THE COASTAL LOW TAKES SHAPE.
THERE WILL BE AN ENHANCED REGION OF 2-D FGEN FORCING PER THE NCEP
MODEL SUITE ACROSS THE SOUTHERN AREAS /MAINLY JUST SOUTH OF THE
CAPITAL REGION/ WHERE SNOWFALL RATES COULD BE ENHANCED. THE
COMBINATION OF THIS SNOWFALL BAND AND THOSE WINDS COULD
POTENTIALLY BRING NEAR BLIZZARD CONDITIONS FOR THE HIGHER TERRAIN
FOR A PERIOD OF TIME. THE REMAINDER THE REGION...SNOW WILL BE
ONGOING WITH LATEST PLUME DIAGRAMS POINTING TOWARD 0.90" H2O
EQUIVALENT FROM THE GEFS/SREF. CROSS SECTIONS REVEAL THE BEST LIFT
FOR THE MOST OF THE REGION WILL OCCUR JUST BELOW THE BEST
DENDRITIC ICE GROWTH WHILE CLOSER TO THE 2D FGEN BANDS THAT WE
EFFECTIVELY TAP INTO THAT DENDRITIC ICE GROWTH. HERE...COULD SEE
SNOWFALL RATES APPROACHING UP TO 2 INCHES PER HOUR. THE ONLY SMALL
ISSUE TO THESE SNOWFALL RATES WILL BE THE DEGREE OF WARM AIR
ADVECTING NORTHWARD. SEEMS SOUTHERN PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES COULD SEE A PERIOD OF SLEET/FZRA PER TOP-DOWN
THERMAL APPROACH FROM AN ENSEMBLE TREND OF THE NCEP MODELS.
SUNDAY...THE MAIN STORM CENTER NOW REFORMS AND INTENSIFIES OVER
THE GULF OF MAINE SUNDAY MORNING. THERE COULD BE A PERIOD OF THE
MOHAWK VALLEY CONVERGENCE PER CSTAR RESEARCH WHICH WILL NEED TO BE
MONITORED. OTHERWISE...SNOW WILL GRADUALLY DIMINISH IN COVERAGE
AND INTENSITY THROUGH THE DAY AS WE TRANSITION TO LIGHT SNOW
SHOWERS AND UPSLOPE FAVORED LOCATIONS FOR SOME ADDITIONAL SNOW
ACCUMULATIONS.
AT THE END OF THIS EVENT...COULD SEE VALUES OF 6-12 INCHES ACROSS
THE REGION HENCE THE WINTER STORM WATCH IN EFFECT FOR THE ENTIRE
REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE DEPARTING WINTER STORM WILL CONTINUE TO LIFT NORTHEAST TOWARDS
ATLANTIC CANADA...WITH COLD CYCLONIC FLOW IN PLACE OVER THE
NORTHEASTERN US IN ITS WAKE. SOME LINGERING LAKE ENHANCED SNOW
SHOWERS WILL AFFECT THE WESTERN ADIRONDACKS AND WESTERN MOHAWK
VALLEY ON SUNDAY NIGHT WITH VERY COLD TEMPS...THANKS TO THE FRESH
SNOW COVER AND DIMINISHING WINDS. MOST AREAS LOOK TO DROP INTO THE
SINGLE DIGITS...WITH BELOW ZERO READINGS POSSIBLE OVER THE HIGH
TERRAIN...ESP IN THE ADIRONDACKS.
HIGH PRESSURE WILL PASS OVER THE REGION ON MONDAY...ALLOWING FOR DRY
WEATHER WITH BELOW NORMAL TEMPS. HIGHS WILL ONLY REACH THE TEENS TO
LOW 20S WITH PARTIAL SUNSHINE.
CLOUDS WILL QUICKLY INCREASE FOR MONDAY NIGHT AS A CLIPPER SYSTEM
DIVES FROM SOUTHERN CANADA TOWARDS THE GREAT LAKES. THERE IS GOOD
MODEL AGREEMENT THAT THIS SYSTEM WILL SLIDE ACROSS THE NORTHEAST FOR
LATE MONDAY NIGHT INTO TUESDAY. AS A RESULT...A SEVERAL HOUR PERIOD
OF LIGHT SNOW LOOKS TO MOVE ACROSS THE REGION. MOISTURE WILL BE
LIMITED...AND ANY SNOWFALL LOOKS TO BE LESS THAN ADVISORY LEVEL
AMOUNTS. TEMPS WILL CONTINUE TO BE VERY COLD...WITH SINGLE DIGITS
MONDAY NIGHT...AND MAINLY 20S ON TUESDAY.
BEHIND THIS SYSTEM...ANOTHER ROUND OF LAKE EFFECT SNOW LOOKS TO
IMPACT THE WESTERN ADIRONDACKS FOR TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. MEANWHILE...DRY WEATHER BUT BELOW NORMAL TEMPS WILL CONTINUE
ACROSS THE REMAINDER OF THE FORECAST AREA. MIN TEMPS TUESDAY NIGHT
WILL BE IN THE TEENS TO NEAR 20...WITH 20S TO LOW 30S DURING THE DAY
WEDNESDAY...AND TEENS AGAIN ON WED NIGHT.
THE LAKE EFFECT SHOULD SHUT OFF SOMETIME THURSDAY...AS A LARGE AREA
OF HIGH PRESSURE PASSES OVER THE AREA. SOME MODERATION IN TEMPS
WILL START TO OCCUR...AS A TROUGH BEGINS TO GET CARVED OUT ACROSS
THE WESTERN US AND RIDGING DEVELOPS ACROSS THE SOUTHEASTERN US. THIS
WILL PUT OUR REGION IN A SW FLOW ALOFT. TEMPS ON THURSDAY MAY
FINALLY REACH THE FREEZING MARK IN THE CAPITAL REGION...ALTHOUGH
HIGH TERRAIN AREAS WILL STILL BE IN THE 20S. THE WARMING TREND
APPEARS TO CONTINUE RIGHT INTO THE UPCOMING WEEKEND.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TERMINALS THIS MORNING WITH SOME
SCT-BKN STRATOCU CLOUDS AROUND 4 KFT AND A BKN-OVC MID LEVEL DECK
AROUND 10 KFT.
DURING THE LATE MORNING TO EARLY AFTN HOURS...AN ARCTIC FRONTAL
BOUNDARY...AIDED BY SOME MOISTURE OFF LAKE ONTARIO...WILL PASS
THROUGH THE REGION FROM NORTH TO SOUTH. CONVERGENCE ALONG THIS
BOUNDARY MAY ALLOW FOR SOME SNOW SHOWERS OR SQUALLS ACROSS THE
REGION. THE BEST CHANCE WILL BE FOR KALB/KPSF...AS THE SNOW SHOWERS
MAY PASS DOWN THE MOHAWK VALLEY AND TOWARDS THE CAPITAL
REGION/BERKSHIRES. WE HAVE INCLUDED A TEMPO TO ACCOUNT FOR THIS
POSSIBILITY FOR A BRIEF PERIOD OF IFR CONDITIONS WITHIN SNOW
SHOWERS/SQUALLS DURING THE LATE MORNING/EARLY AFTN. OUTSIDE OF SNOW
SHOWERS...CIGS WILL BE BKN AROUND 4 KFT DURING THE LATE MORNING TO
AFTN HOURS. CLOUDS SHOULD START TO CLEAR BY THIS EVENING WITH JUST
FEW-SCT LOW CLOUDS AND SOME PASSING CIRRUS OVERNIGHT.
WINDS WILL BE S-SW AHEAD OF THE BOUNDARY...BECOMING WESTERLY AT
AROUND 10 KTS THIS MORNING. BEHIND THE BOUNDARY...WINDS WILL BE
W-NW AT 10-15 KTS WITH A FEW HIGHER GUSTS...ESP AT
KALB/KPSF...WHERE WINDS MAY GUST AS HIGH AS 25 KTS. WINDS WILL
DIMINISH THIS EVENING WITH THE LOSS OF DAYTIME HEATING...AND WILL BE
NW OVERNIGHT AT 10 KTS OR LESS.
OUTLOOK...
SATURDAY-SUNDAY: HIGH OPERATIONAL IMPACT. DEFINITE SN.
SUNDAY NIGHT-MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT-TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED THROUGH EARLY NEXT WEEK.
MAINLY SNOW WILL FALL THIS WEEKEND AND TEMPERATURES WILL BE WELL
BELOW NORMAL AND ICE WILL CONTINUE TO FORM ON AREA RIVERS...STREAMS
AND PARTICULARLY LAKES THROUGH EARLY NEXT WEEK.
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...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR CTZ001-013.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ033-038.
LAKE EFFECT SNOW WARNING UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ032.
MA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR MAZ001-025.
VT...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
508 AM CST Fri Dec 13 2013
...Updated for Aviation...
.SYNOPSIS...
ISSUED AT 242 AM CST FRI DEC 13 2013
The center of an upper low was moving across Arizona overnight as
observed on water vapor imagery. Just upstream was a broad area of
positive vorticity advection across new Mexico into the panhandles,
where the leading edge of the upper jet was also located. Very weak
pressure falls were occurring and were widespread from the northern
High Plains region of Wyoming and Nebraska to north central Texas.
METAR objective analysis indicated warm surface frontogenesis was
developing from southeast Colorado into western Oklahoma. An
extremely dry 00 UTC KDDC sounding was likely contributing to a
pronounced lack of radar precipitation echoes advancing any farther
than the Oklahoma/Kansas line near Coldwater and Medicine lodge.
Surface temperatures around 1 am were steady to slowly warming south
and east of Dodge city.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 242 AM CST FRI DEC 13 2013
The last run of the NAM and recent HRRR models appeared to represent
the thermodynamic and precipitation areal coverage very well by
keeping extremely low precipitation/QPF accumulations mainly across
western Oklahoma into areas of western Kansas east of Medicine
Lodge. Even with the advancing upper system from the southern
Rockies, the isentropic fields indicate an increasingly downslope
profile after about 09-12 UTC.
The WRF model is still having problems with ground snow across the
I-70 corridor, which hasn`t existed for a few days. However the
solution is probably not bad farther south and west where it
forecasts temperatures as high as around 50 degrees. As the pressure
falls persist, a surface low will develop southeastward into the
panhandles this afternoon. The local GFS mos products forecast
stronger surface winds behind the attendant surface cold frontal
boundary later into Friday night especially toward midnight. This is
a reasonable solution as the surface low will move rapidly across
the southern plains and the upper trough swings across the region
just in time to add to a deep subsident profile for western
Kansas.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 242 AM CST FRI DEC 13 2013
A significant Arctic outbreak is the offing coming up next Thursday
or Friday time frame. As with many Arctic events, the long range
models struggle with the timing and normally are too slow with these
Arctic fronts. Current long range model trends are suggesting a bit
slower solution to the Arctic fropa, but like mentioned above they
do not normally pan out that way. Current thoughts are a frontal
passage around Thursday afternoon. There may be a strong temperature
contrast by Thursday afternoon from Hays to Medicine Lodge. Current
high temps from the mid 40s around Hays to the low to mid 50s in the
Medicine Lodge area may need significant adjustment downward if a
faster solution bears out. Some light snow is also possible into
next weekend of December 21st and 22nd, however should be light
accumulations.
Ahead of the Arctic front, from Saturday into Wednesday, a warming
trend begins Sunday with temperatures rising from the low to mid 40s
on Saturday behind a cold front, and into the 50s through Wednesday.
A cold upper trough will be moving across the Plains on Saturday
followed by dry northwest flow aloft and downslope and warmer
surface winds. Overnight lows look to gradually warm from the low to
mid 20s on Saturday night into the upper 20s into Wednesday night.
&&
.AVIATION...(For the 12Z TAFS through 12Z Saturday morning)
ISSUED AT 503 AM CST FRI DEC 13 2013
VFR conditions will continue into Saturday. An upper level trough
will swing across the Central Plains today pushing a cold front
across western Kansas. Light and variable winds will become north
with the front around 15-18Z at 10-20kt then as the pressure gradient
increases later tonight with cold air advection, north winds increase to
15-25kt.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 47 21 43 23 / 0 10 0 0
GCK 50 20 46 21 / 0 0 0 0
EHA 49 23 46 24 / 0 0 0 0
LBL 50 22 46 24 / 0 0 0 0
HYS 42 17 39 21 / 10 10 0 0
P28 49 22 40 22 / 10 10 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Kruse
AVIATION...Kruse
AREA FORECAST DISCUSSION
NWS CARIBOU ME
913 AM EST FRI DEC 13 2013
.SYNOPSIS...
LOW PRESSURE WILL CROSS NORTHERN MAINE THIS MORNING AND DRAG AN
ARCTIC COLD FRONT ACROSS THE REGION THIS AFTERNOON. COLD HIGH PRESSURE
WILL THEN BUILD INTO THE AREA SATURDAY. LOW PRESSURE WILL APPROACH
FROM THE SOUTH SATURDAY NIGHT...AND PASS EAST OF THE REGION
SUNDAY.&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 0905L: WEAK CLIPPER NOW E OF THE AREA W/ AREA OF VRY LGT
SNW E INTO NB AS WELL... CAA COMMENCING ONCE AGAIN ACROSS THE AREA
ATTM BEHIND THIS SYSTEM AND THIS WILL REINFORCE THE VRY COLD
AIRMASS WHICH HAS SETTLED OVR THE AREA LAST FEW DYS. BRISK NW FLOW
WILL ALSO LIKELY TOUCH OFF A FEW STREAMERS OFF OF THE ST LAWRENCE
THIS AFTN W/ THE HRRR NICELY DEPICTING THIS ACTIVITY ACROSS N
CENTRAL INTO E CENTRAL AREAS FROM ERLY THRU LATE AFTN. HAVE TRIED
TO REPRESENT THIS EXPECTED SCENARIO IN OUR POP AND WX GRIDS BUT
MAY NEED TO ADJUST AS THIS ACTIVITY DVLPS SINCE THESE STREAMERS
CAN BE QUITE LOCALIZED AND DIFFICULT TO PINPOINT IN ADVANCE...
REMAINDER OF THE FCST ON TRACK ATTM...
PREVIOUS DISCUSSION...
THE WEAK CLIPPER LOW WILL CROSS NORTHERN MAINE THIS MORNING AND
REDEVELOP IN THE CANADIAN MARITIMES THIS AFTERNOON. THE CLIPPER
WILL BRING LIGHT SNOW TO NORTHERN ZONES THIS MORNING...MOSTLY
NORTH OF HOULTON. ACCUMULATIONS COULD REACH AN INCH AND POSSIBLY
UP TO 2 INCHES IN HIGHER TERRAIN WITHIN NORTHERN AROOSTOOK COUNTY. AS
THE LOW MOVES EAST OF THE FORECAST AREA...IT WILL DRAG AN ARCTIC
FRONT THROUGH THE AREA. SOME SNOW SQUALLS ARE POSSIBLE. IT APPEARS
THE SQUALL WILL ORGANIZE FROM HOULTON WEST TO THE KATAHDIN REGION
TOWARDS MIDDAY AND THEN SWEEP SOUTH TOWARDS WASHINGTON COUNTY THIS
AFTERNOON AS IT DISSIPATES. SOUTHERN PORTIONS OF THE FORECAST AREA
SUCH AS BANGOR SHOULD ESCAPE THE SNOW OUTSIDE OF A BRIEF SNOW
SHOWER AS THE ARCTIC FRONT CROSSES. WITH SOME SUN...THE
BANGOR/BREWER AREA SHOULD REACH NEAR 20F TODAY. FURTHER
NORTH...ONLY SINGLE DIGITS ARE FORECAST FOR CARIBOU NORTHWARD INTO
THE SAINT JOHN VALLEY. THE ARCTIC FRONT WILL BRING ANOTHER ROUND
OF BITTER COLD AND WINDS FOR LATER THIS AFTERNOON AND TONIGHT.
WIND CHILLS MAY DROP TO LESS THAN MINUS 30 IN NORTHERN AROOSTOOK
AND HAVE ISSUED A WIND CHILL ADVISORY FOR AROOSTOOK...NORTHERN
PISCATAQUIS AND NORTHERN PENOBSCOT COUNTIES FOR TONIGHT. LOWS WILL
DROP TO MINUS 10 TO MINUS 20 IN THESE AREAS WITH WINDS GUSTING TO
OVER 20 MPH. THE WINDS WILL DECREASE LATER IN THE NIGHT AS HIGH
PRESSURE BUILDS. ELSEWHERE...LOWS OF ZERO TO TEN BELOW ARE
EXPECTED.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
*MAIN ISSUES WILL BE LOW WIND CHILLS SAT MORNING AND A POTENTIAL
SNOWSTORM SUNDAY.
*WINTER STORM WATCHES HAVE BEEN ISSUED FOR THE SOUTHERN HALF OF THE
CWA FOR LATE SAT NIGHT AND SUNDAY.
A COLD HIGH CENTERED JUST WEST OF QUEBEC CITY AT 12Z SAT WILL
GRADUALLY LIFT TO THE NORTH OF THE AREA SAT NIGHT. AS THE CENTER OF
THE HIGH IS WEST OF THE AREA FIRST THING SAT MORNING THERE WILL BE
SOME WIND AND THE POTENTIAL FOR LOW WIND CHILLS SAT MORNING. THE
WIND SPEED LOOKS MARGINAL (AROUND 10 MPH). WIND CHILL ADVISORIES
WERE ISSUED FOR TONIGHT AND EXTENDED INTO SAT MORNING.
LOW PRESSURE ACROSS THE GULF COAST STATES SAT MORNING IS EXPECTED TO
LIFT UP TO NEAR NANTUCKET BY 12Z SUN AND CONTINUE TO DEEPEN AS
THE LOW RACES NE AND PASSES JUST EAST OF NOVA SCOTIA SUN
AFTERNOON AND EVENING. SNOW IS EXPECTED TO DEVELOP FROM THE
SOUTHWEST AFTER MIDNIGHT SAT NIGHT AND SNOW SHOULD BE FALLING
ACROSS MOST IF NOT ALL OF DOWNEAST MAINE BY 12Z SUN. THE SNOW
WILL OVERSPREAD THE REMAINDER OF THE CWA SUN MORNING. GIVEN THE
TRACK OF THE LOW THE HEAVIEST SNOW WILL FALL ACROSS DOWNEAST AREAS
WITH AMOUNTS DROPPING OFF TO THE NORTH OF THE KATAHDIN REGION. AS
THE MODELS HAVE NOW JOGGED BACK A BIT TO THE WEST IT NOW APPEARS
THAT THERE IS A GOOD CHANCE OF 8-14 INCHES OF SNOW ACROSS DOWNEAST
MAINE. THE STORM IS PROGRESSIVE WITH AN INCOMING UPPER TROUGH FROM
THE WEST IT IS UNLIKELY THAT AMOUNTS WILL EXCEED MUCH MORE THAN 14
INCHES. THE LATEST 00Z GFS IS EVEN FURTHER TO THE WEST TAKING THE
LOW RIGHT OVER NOVA SCOTIA AND WOULD BRING WARNING CRITERIA SNOW
ALL THE WAY NORTH AND ACROSS THE CROWN OF MAINE AND MIGHT EVEN
INTRODUCE A BIT OF A MIX ALONG THE IMMEDIATE COAST FOR A BRIEF
TIME SUN AFTERNOON. THE 00Z OPERATIONAL GFS IS FURTHER WEST THAN
ITS ENSEMBLE MEAN AND THERE ARE ONLY A COUPLE OF ENSEMBLE MEMBERS
THAT ARE AS FAR WEST AS THE OPERATIONAL GFS. THE LATEST 00Z ECMWF
IS VERY CONSISTENT WITH ITS PREVIOUS RUN AND IS ALSO VERY CLOSE TO
THE GFS ENSEMBLE MEAN AND CANADIAN GEM. FORECASTER CONFIDENCE IS
HIGH ENOUGH TO ISSUE A WINTER STORM WATCH FOR LATE SAT NIGHT INTO
SUNDAY FOR DOWNEAST AREAS INTO CENTRAL MAINE WITH THE IDEA THAT
LATER SHIFTS CAN REFINE THE AREA AS NEEDED. THE FORECAST AMOUNTS
ARE BASED VERY CLOSELY ON A BLEND OF THE GFS ENSEMBLE
MEAN/OPERATIONAL ECMWF/CANADIAN. THE HEADLINES WERE WELL
COLLABORATED WITH WFO GYX AND DISCUSSED WITH THE WPC.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE SFC LOW PULLS AWAY FROM THE REGION SUN NIGHT AND MON WITH AN
INVERTED TROUGH EXTENDING BACK ACROSS THE AREA. THE MID/UPPER LEVEL
LOW FOLLOWS SUN NIGHT INTO MON MORNING. THIS WILL LIKELY KEEP SOME
LIGHTER SNOW FALLING ACROSS PARTS OF NORTHERN AND EASTERN MAINE
INTO MON MORNING. HIGH PRESSURE THEN BUILDS ACROSS THE REGION MON
NIGHT. AN INTERESTING LOOKING CLIPPER MOVES ACROSS THE AREA
TUE WITH A GOOD CHANCE OF SNOW. THE MODELS ARE HINTING AT A
SECONDARY THAT MAY DEVELOP IN THE GULF OF MAINE AND PRODUCE MORE
SIGNIFICANT SNOWS ACROSS THE AREA TUE NIGHT INTO WED. THU LOOKS
MAINLY DRY AND SEASONABLY COLD AS THE LOW MOVES OUT OF THE AREA
AND IS AT LEAST BRIEFLY REPLACED BY A RIDGE OF HIGH PRESSURE
BUILDING IN FROM THE WEST.
&&
.AVIATION /14Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: MOSTLY IFR THIS MORNING NORTH OF HUL IN SNOW. VFR IS
EXPECTED THROUGH THE PERIOD FOR BGR AND BHB. SNOW SQUALLS MAY SET
UP WITH AN ARCTIC COLD FRONT CROSSING THE REGION LATER THIS
MORNING AND EARLY AFTERNOON...MOST LIKELY AFFECTING HUL. SOME MVFR
CIGS ARE POSSIBLE AT TIMES FROM PQI NORTHWARD THIS AFTERNOON AND
TONIGHT.
SHORT TERM: VFR SAT INTO THE FIRST HALF OF SAT NIGHT. CONDITIONS
WILL DETERIORATE LATE SAT NIGHT WITH IFR AND EVEN SOME VLIFR IN SNOW
SUNDAY...ESPECIALLY AT THE SOUTHERN TERMINALS. MOSTLY IFR/MVFR IN
AREAS OF LIGHT SNOW THAT WILL LIKELY PERSIST INTO MONDAY. ANOTHER
SYSTEM MAY QUICKLY FOLLOW WITH MORE IFR/MVFR IN SNOW TUE.
&&
.MARINE...
NEAR TERM: HAVE UPGRADED THE SCA TO A GALE WARNING FOR TODAY WITH
THE STRONG PRESSURE GRADIENT AHEAD OF AN ARCTIC FRONT AND STRONG
NW WINDS BEHIND THE FRONT BRINGING BITTER COLD AIR OVER THE
RELATIVELY WARM WATERS. WILL GO WITH A SCA FOR THE INTRACOASTAL
THROUGH TONIGHT. WHEN THE GALE ENDS THIS EVENING...AN SCA WILL BE
NEEDED TO REPLACE IT.
SHORT TERM: A GALE IS POSSIBLE FOR A TIME SUNDAY AS LOW PRESSURE
DEEPENS AS IT PASSES EAST OF THE FORECAST WATERS. A GUSTY WIND ON
THE BACKSIDE OF LOW WILL LIKELY KEEP AT LEAST SCA CONDITIONS GOING
INTO MONDAY. THE WIND WILL DIMINISH AND THE SEAS SUBSIDE MON NIGHT
BELOW SCA LEVELS AS HIGH PRESSURE BRIEFLY BUILDS OVER THE WATERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
SATURDAY FOR MEZ001>006-010.
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY
EVENING FOR MEZ011-015>017-029>032.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ052.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ050-051.
&&
$$
NEAR TERM...KHW/MCW
SHORT TERM...CB
LONG TERM...CB
AVIATION...KHW/MCW/CB
MARINE...KHW/MCW/CB
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
453 AM MST FRI DEC 13 2013
.AVIATION...
12Z TAF CYCLE
AN UPPER TROUGH AND SURFACE COLD FRONT CROSSING FROM THE W WILL
CONTINUE TO PRODUCE MVFR AND PATCHY IFR CONDITIONS IN SNOW SHOWERS
OVER CENTRAL AND WESTERN PARTS OF THE FORECAST AREA THROUGH THE
MORNING. MOUNTAIN OBSCURATIONS ARE ALSO EXPECTED. FURTHER...PATCHY
FOG AND LOW CLOUDS WILL CONTINUE TO AFFLICT THE PECOS RIVER
VALLEY UNTIL MID MORNING. WINDS WILL SHIFT OUT OF THE NW AND
BECOME GUSTY AS THE A COLD FRONT CROSSES. THE STRONGEST WINDS
WILL BE FOUND EAST OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS
WHERE GUSTS MAY REACH 45 KT FROM LATE MORNING TO MID AFTN. A
SECONDARY UPPER TROUGH COULD TRIGGER A FEW LIGHT SNOW SHOWERS AND
MOUNTAIN OBSCURATIONS IN THE NORTHERN MOUNTAINS TONIGHT...ESPECIALLY
NEAR THE CO BORDER.
44
&&
.PREV DISCUSSION...259 AM MST FRI DEC 13 2013...
WATER VAPOR LOOP THIS MORNING SHOWING UPPER LOW OPENING UP OVER AZ
AS IT TRAVELS QUICKLY EAST TOWARD NM. PRECIP ACTIVITY WITH FORCING
AHEAD OF THE WAVE IS SHOWERY IN NATURE AND MOVING QUICKLY EAST INTO
THE RIO GRANDE VALLEY. LIGHT SNOW ACCUMS WILL OCCUR IN BRIEF BOUTS
OF CONVECTIVE ACTIVITY. THE EXCEPTION WILL BE WEST FACING SLOPES OF
THE CENTRAL MT CHAIN WHERE ENHANCED UPSLOPE WILL SQUEEZE OUT MORE
STRATIFORM ACTIVITY FOR SEVERAL HOURS THIS MORNING...EQUATING TO
PERHAPS AN INCH OR TWO ABOVE 7500 FT. THE HRRR ENSEMBLE REFLECTIVITY
PRODUCT IS HANDLING THE CURRENT DISTRIBUTION OF PRECIP WELL SO LEFT
POPS THIS MORNING AROUND THE ABQ METRO AREA AND SURROUNDING HIGH
TERRAIN IN THE MODERATE TO HIGH CHANCE RANGE.
THE MAIN STORY TODAY WILL BE WINDS ALONG AND EAST OF THE CENTRAL MT
CHAIN WHERE FAST LAMINAR FLOW WITHIN THE EXITING UPPER TROUGH WILL
COMBINE WITH A DEEPENING SURFACE LOW OVER THE PLAINS. SPC WRF-ARW
INDICATES 850-700MB LAYER WINDS OF 30-35KTS STRETCHING DOWN THE U.S.
285 CORRIDOR FROM CLINES TO VAUGHN...ALONG 54 NEAR CORONA...AND MUCH
OF LINCOLN AND WESTERN CHAVES COUNTIES. WINDS WILL INCREASE THRU THE
MORNING AND PEAK NEAR 2 PM THEN TAPER OFF BY SUNSET.
A RATHER STOUT UPPER WAVE IN NW FLOW WILL SHIFT QUICKLY OVER THE
AREA BEHIND THIS DEPARTING WAVE AND DELIVER ANOTHER PUNCH OF COLDER
AIR FOR SATURDAY. HIGHS WILL BE ROUGHLY 5 TO 10F BLW NORMAL. TEMPS
WILL MODERATE BACK TO NEAR NORMAL SUNDAY AND CONTINUE WARMING THRU
MID WEEK AS UPPER FLOW BACKS MORE ZONAL. MODELS ARE STILL CLOSING IN
ON A WHOPPER OF A STORM FOR LATE IN THE WEEK WITH ANOTHER SURGE OF
BITTER COLD AIR...SNOW...AND STRONG WINDS.
GUYER
.FIRE WEATHER...
AS EXPECTED THE BAJA LOW APPROACHING FROM THE WEST SOUTHWEST IS
WEAKENING INTO AN OPEN TROUGH AND WILL PASS EASTWARD OVER THE FIRE
WEATHER FORECAST AREA TODAY. MAINLY SCATTERED SNOW SHOWERS ARE EXPECTED
THIS MORNING ALONG AND WEST OF THE CENTRAL MOUNTAIN CHAIN. THIS
AFTERNOON THE BASE OF THE TROUGH WILL BE EXITING...BUT ANOTHER UPPER
TROUGH WILL DROP SOUTHEASTWARD TOWARD NM QUICKLY ON THE HEELS OF THE
FIRST SYSTEM. THIS WILL KEEP ISOLATED RAIN AND SNOW SHOWERS IN THE
FORECAST MAINLY FROM THE CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAIN
CHAIN THROUGH THE AFTERNOON.
BETWEEN THE TWO UPPER TROUGHS A NORTHWESTERLY 700 MB WIND SPEED
MAXIMUM WILL DEVELOP ALONG THE CONTINENTAL DIVIDE AND CENTRAL
MOUNTAIN CHAIN...ESPECIALLY SOUTH OF THE NORTHERN MOUNTAINS...WITH
SPEEDS PEAKING AROUND 30-45 KTS DURING THE EARLY TO MID AFTERNOON.
AT THE SURFACE A 1007 MB SURFACE LOW IN SE CO WILL SINK
SOUTHEASTWARD ACROSS THE TX PANHANDLE TODAY...KEEPING THE SURFACE
PRESSURE GRADIENT TIGHT ALONG AND EAST OF THE CENTRAL MOUNTAINS. NW
WIND GUSTS IN THE 30 TO 40 MPH RANGE WILL BE COMMON IN THE W CENTRAL
AND SW MOUNTAINS TODAY...WITH GUSTS FROM 40 TO 50 MPH ALONG AND EAST
OF THE CENTRAL MOUNTAINS TO THE PECOS RIVER VALLEY. AS A RESULT OF
THE STRONGER WINDS...GOOD TO EXCELLENT VENTILATION ARE EXPECTED
MAINLY SOUTH OF I-40 TODAY WITH BROAD POCKETS OF POOR VENTILATION
ACROSS THE NORTH.
TROUGHING IN NW FLOW ALOFT AND COLD AIR ADVECTION AT THE SURFACE
WILL LINGER OVER NM THROUGH SATURDAY. COOLING THAT BEGINS ACROSS
NORTHERN AND WESTERN AREAS TODAY WILL SPREAD TO INCLUDE SOUTHEAST
AREAS ON SATURDAY. HIGH TEMPERATURES SATURDAY WILL BE A FEW TO 10
DEGREES BELOW TODAYS READINGS. VENT RATES SHOULD PLUMMET IN MOST
LOCATIONS SATURDAY...EXCEPT ACROSS THE FAR EASTERN PLAINS WHERE GOOD
OR BETTER VENTILATION IS EXPECTED DUE TO PERSISTENT NORTH WINDS.
UNDER NW FLOW ALOFT DRY WEATHER IS EXPECTED SATURDAY THROUGH THE
MIDDLE OF THE COMING WORK WEEK WITH HUMIDITIES TRENDING DOWNWARD
EACH DAY THROUGH TUESDAY BEFORE THEY STABILIZE. TEMPERATURES WILL
TREND UPWARD THROUGH TUESDAY AS WELL WITH HIGHS REACHING ABOVE
NORMAL AREAWIDE BEGINNING MONDAY. AFTER GENERALLY POOR VENTILATION
SUNDAY THROUGH WEDNESDAY...VENT RATES SHOULD BEGIN TO IMPROVE ON
THURSDAY AS AN UPPER TROUGH DIGS INTO THE WESTERN US AND SW FLOW
ALOFT BEGINS TO STRENGTHEN OVER NM. SW WINDS SHOULD ALSO BEGIN TO
STRENGTHEN THURSDAY ACROSS WESTERN AND EAST CENTRAL PARTS OF THE
FORECAST AREA.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY FROM 10 AM THIS MORNING TO 4 PM MST THIS AFTERNOON
FOR THE FOLLOWING ZONES...NMZ521>524-526-533-537>539.
&&
$$
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1004 AM EST FRI DEC 13 2013
.SYNOPSIS...
LAKE EFFECT SNOW WILL TAPER OFF LATER TODAY AS A STORM APPROACHES
THE AREA FROM THE SOUTH. THIS SYSTEM WILL SPREAD SNOW ACROSS THE
AREA ON SATURDAY...WITH THE CHANCE FOR SOME ICE OVER PARTS OF
NORTHEAST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1000 AM UPDATE...LES BAND EAST OF LAKE ONTARIO NOW MAKING GOOD
PROGRESS SOUTH AS SFC TROF DROPS THROUGH THE LAKE REGION. LOCAL
ARW HANDLING THE CURRENT ORIENTATION WELL AND EXPECT THE BULK OF
ACTIVITY TO BE SOUTH OF NRN ONEIDA COUNTY AROUND MIDDAY. CURRENT
WARNING TIMING HERE LOOKS GOOD. ACTIVITY IS NOW DROPPING SOUTH
INTO THE ADVISORY AREA. BAND WILL WEAKEN AS IT DROPS SOUTH DUE TO
SHORTER FETCH AND GRADUALLY LOWERING INVERSION. LAKE EFFECT SNOW
SHOWERS WILL CONTINUE IN THE ADV AREA UNTIL MID AFTERNOON THEN
WEAKEN. JUST MINOR ADJUSTMENTS TO CURRENT FORECAST.
PREVIOUS DISC...
TRICKY LES FCST AS THE SHRT TERM MODELS ARE IN POOR AGREEMENT.
WRFARW SHOWS THE BAND DROPPING SWRD INTO THE DAYLIGHT HERS BEFORE
DISAPPATING MIDDAY. NAM SHOWS THE BAND PRETTY MUCHH WEAKENING IN
PLACE WITH ONLY A SLGT SWRD DRIFT. CRNTS SHOW THE SFC FLOW OVER
WRN NY BCMG SWLY MAKING ME WONDER IF THE BAND WILL EVER MAKE IT
INTO THE WARNING/ADVISORY AREA. AT THE VERY LEAST...INCRSD LL
SHEAR WILL WEKEN THE SYSTEM. IN ANY CASE...WILL LEAVE THE FLAGS IN
PLACE FOR NOW BUT MAY BE LOOKING A MODIFYING THE FLAGS EARLY ON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
ONLY A BRIEF BRK IN THE ACTION AHD OF THE NEXT SYSTEM. OVERRUNING
PCPN DVLPS LATE FRI NGT AND EARLY SAT UNDER THE RR OF THE UPR JET.
OVERALL THE UPWARD VERTICAL MOTION IS MODERATE AT BEST AND
MOISTURE IS NOT EXACTLY DEEP AS THE INITIAL SOURCE REGION IS THE
UPR PLAINS. THIS SHD RESULT IN LGT SNOWS FOR THE INITIAL HRS OF THE
STORM.
LTR SAT...DEEPER MOSITURE FROM THE GULF ARRIVES AS THE SRN BRANCH
SYSTEM DVLPS A SFC LOW MVG NWRD IN THE TN VLY. SYSTEM HAS DBL SFC
LOWS EARLY ON WITH A LOW OVER OH WHILE A CSTL LOW DEEPENS OVER ERN
NC. LOWS CONSOLIDATE ARND 06Z SUN OVER CSTL NJ AND BEGIN TO DEEPEN
MORE RAPIDLY. GOOD DEEP ELY FLOW DVLPS LATE IN THE GAME AND A PD
OF HEAVIER SNOW SEEMS LIKELY LATE SAT NGT BEFORE THE SNOW TAPERS
OFF SUN MRNG. EVEN SO...BEST UVM IS NOT EXACTLY WELL ALIGNED WITH
THE BEST DENDRITIC GROATH AREA FOR MUCH OF THE STORM. ALSO...
SYSTEM REMAINS AS AN OPEN WV AT THE UPR LVLS SO IS LACKING A GOOD
CHANCE FOR DEFORMATION BANDS DVLPG LATE IN THE EVENT.
EVEN THE NORMALLY ROBUST NAM QPF FCSTS ARE AT HIGH END ADVISORY
LVLS FOR THE STORM LDG ME TO THINK THAT SNOWFALL AMTS WILL BE BLO
WARNING CRITERIA. BEST CHANCE FOR HIER AMTS APPEAR TO BE OVER THE
WRN CATS AND PERHAPS XTTRM NEPA. FURTHER SOUTH...THERE/S STILL THE
RISK OF SOME ICE PELLETS OVER THE POCONOS AND SCRANTON METRO AREA.
FRZG RAIN SEEMS LIKE A MORE REMOTE CHANCE WITH THE NARROW ABV FRZG
LYR AND VERY COLD SFC AIR.
KIND OF HEMMED IN BY WATCHES SO WENT WITH A WATCH FOR THE AREA AS
WELL...BUT MOST LIKELY LOOKING AT A HIGH END ADVISORY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE LONG TERM PERIOD BEGINS WITH A PERSISTENT, COLD TROF PARKED
OVER THER NORTHEASTERN UNITED STATES. THIS PATTERN WILL SLOWLY
WEAKEN AND ERODE THROUGH MID WEEK, AS THE FLOW RELAXES TO A MORE
ZONAL PATTERN. BY THURSDAY A JET WILL BEGIN TO DIVE INTO THE
WESTERN U.S. ALLOWING HEIGHTS TO RISE IN THE EAST. THIS WILL LEAD
TO A TEMPORARY MODERATION IN TEMPERATURE.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
WRFARW MODEL WAS TOO AGGRESSIVE OVERNIGHT IN BRINGING THE LAKE
ONTARIO BAND SOUTHWARD, AND PUSHING THE LAKE ERIE BAND INTO THE
CENTRAL SOUTHERN TIER AND FINGER LAKES. LATEST HRRR LOOKS MORE IN
TUNE WITH REALITY, AND I WILL LEAN IN ITS DIRECTION WITH THE NEW
TAF PACKAGE. IN GENERAL...WILL BE CUTTING BACK ON THE RESTRICTIONS
OVER ELM/ITH/BGM AND DELAYING THE ONSET AT RME UNTIL 12Z-15Z.
OUTLOOK...
SAT/SUN...RESTRICTIONS LIKELY REGION-WIDE IN SNOW AS STORM SYSTEM
MOVES THROUGH THE AREA...WITH EACH TERMINAL EXPERIENCING IFR OR
WORSE AT TIMES.
SUN NGT/MON/TUE...RESTRICTIONS POSSIBLE FROM LAKE EFFECT SNOW SHOWERS
ESPECIALLY KSYR-KRME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ009-015>018-022>025-036-037-044>046-
055>057-062.
LAKE EFFECT SNOW WARNING UNTIL NOON EST TODAY FOR NYZ009.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/RRM
SHORT TERM...DGM/PVN
LONG TERM...DJP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
544 AM EST FRI DEC 13 2013
.SYNOPSIS...
LAKE EFFECT SNOW WILL TAPER OFF LATER TODAY AS A STORM APPROACHES
THE AREA FROMM THE SOUTH. THIS SYSTEM WILL SPREAD SNOW ACROSS THE
AREA DURING SATURDAY...WITH THE CHANCE FOR SOME ICE OVER PARTS OF
NORTHEAST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
TRICKY LES FCST AS THE SHRT TERM MODELS ARE IN POOR AGREEMENT.
WRFARW SHOWS THE BAND DROPPING SWRD INTO THE DAYLIGHT HERS BEFORE
DISAPPATING MIDDAY. NAM SHOWS THE BAND PRETTY MUCHH WEAKENING IN
PLACE WITH ONLY A SLGT SWRD DRIFT. CRNTS SHOW THE SFC FLOW OVER
WRN NY BCMG SWLY MAKING ME WONDER IF THE BAND WILL EVER MAKE IT
INTO THE WARNING/ADVISORY AREA. AT THE VERY LEAST...INCRSD LL
SHEAR WILL WEKEN THE SYSTEM. IN ANY CASE...WILL LEAVE THE FLAGS IN
PLACE FOR NOW BUT MAY BE LOOKING A MODIFYING THE FLAGS EARLY ON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
ONLY A BRIEF BRK IN THE ACTION AHD OF THE NEXT SYSTEM. OVERRUNING
PCPN DVLPS LATE FRI NGT AND EARLY SAT UNDER THE RR OF THE UPR JET.
OVERALL THE UPWARD VERTICAL MOTION IS MODERATE AT BEST AND
MOISTURE IS NOT EXACTLY DEEP AS THE INITIAL SOURCE REGION IS THE
UPR PLAINS. THIS SHD RESULT IN LGT SNOWS FOR THE INITIAL HRS OF THE
STORM.
LTR SAT...DEEPER MOSITURE FROM THE GULF ARRIVES AS THE SRN BRANCH
SYSTEM DVLPS A SFC LOW MVG NWRD IN THE TN VLY. SYSTEM HAS DBL SFC
LOWS EARLY ON WITH A LOW OVER OH WHILE A CSTL LOW DEEPENS OVER ERN
NC. LOWS CONSOLIDATE ARND 06Z SUN OVER CSTL NJ AND BEGIN TO DEEPEN
MORE RAPIDLY. GOOD DEEP ELY FLOW DVLPS LATE IN THE GAME AND A PD
OF HEAVIER SNOW SEEMS LIKELY LATE SAT NGT BEFORE THE SNOW TAPERS
OFF SUN MRNG. EVEN SO...BEST UVM IS NOT EXACTLY WELL ALIGNED WITH
THE BEST DENDRITIC GROATH AREA FOR MUCH OF THE STORM. ALSO...
SYSTEM REMAINS AS AN OPEN WV AT THE UPR LVLS SO IS LACKING A GOOD
CHANCE FOR DEFORMATION BANDS DVLPG LATE IN THE EVENT.
EVEN THE NORMALLY ROBUST NAM QPF FCSTS ARE AT HIGH END ADVISORY
LVLS FOR THE STORM LDG ME TO THINK THAT SNOWFALL AMTS WILL BE BLO
WARNING CRITERIA. BEST CHANCE FOR HIER AMTS APPEAR TO BE OVER THE
WRN CATS AND PERHAPS XTTRM NEPA. FURTHER SOUTH...THERE/S STILL THE
RISK OF SOME ICE PELLETS OVER THE POCONOS AND SCRANTON METRO AREA.
FRZG RAIN SEEMS LIKE A MORE REMOTE CHANCE WITH THE NARROW ABV FRZG
LYR AND VERY COLD SFC AIR.
KIND OF HEMMED IN BY WATCHES SO WENT WITH A WATCH FOR THE AREA AS
WELL...BUT MOST LIKELY LOOKING AT A HIGH END ADVISORY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE LONG TERM PERIOD BEGINS WITH A PERSISTENT, COLD TROF PARKED
OVER THER NORTHEASTERN UNITED STATES. THIS PATTERN WILL SLOWLY
WEAKEN AND ERODE THROUGH MID WEEK, AS THE FLOW RELAXES TO A MORE
ZONAL PATTERN. BY THURSDAY A JET WILL BEGIN TO DIVE INTO THE
WESTERN U.S. ALLOWING HEIGHTS TO RISE IN THE EAST. THIS WILL LEAD
TO A TEMPORARY MODERATION IN TEMPERATURE.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
WRFARW MODEL WAS TOO AGGRESSIVE OVERNIGHT IN BRINGING THE LAKE
ONTARIO BAND SOUTHWARD, AND PUSHING THE LAKE ERIE BAND INTO THE
CENTRAL SOUTHERN TIER AND FINGER LAKES. LATEST HRRR LOOKS MORE IN
TUNE WITH REALITY, AND I WILL LEAN IN ITS DIRECTION WITH THE NEW
TAF PACKAGE. IN GENERAL...WILL BE CUTTING BACK ON THE RESTRICTIONS
OVER ELM/ITH/BGM AND DELAYING THE ONSET AT RME UNTIL 12Z-15Z.
OUTLOOK...
SAT/SUN...RESTRICTIONS LIKELY REGION-WIDE IN SNOW AS STORM SYSTEM
MOVES THROUGH THE AREA...WITH EACH TERMINAL EXPERIENCING IFR OR
WORSE AT TIMES.
SUN NGT/MON/TUE...RESTRICTIONS POSSIBLE FROM LAKE EFFECT SNOW SHOWERS
ESPECIALLY KSYR-KRME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ009-015>018-022>025-036-037-044>046-
055>057-062.
LAKE EFFECT SNOW WARNING UNTIL NOON EST TODAY FOR NYZ009.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM
SHORT TERM...DGM/PVN
LONG TERM...DJP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS ALBANY NY
1135 AM EST FRI DEC 13 2013
.SYNOPSIS...
AN ARCTIC FRONTAL BOUNDARY WILL GRADUALLY SLIDE ACROSS THE REGION
TODAY. IN ITS WAKE...HIGH PRESSURE WILL ATTEMPT TO BUILD OVER
THE NORTHERN HALF OF THE REGION TONIGHT. A WINTER STORM WILL TAKE
SHAPE AND IMPACT THE REGION THIS WEEKEND WITH MODERATE TO
SIGNIFICANT AMOUNTS OF SNOW.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1100 AM...THE LAKE EFFECT BAND EAST OF LAKE ONTARIO HAS
DIMINISHED TO NOTHING MORE THAN FLURRIES WHILE THE LAST REMNANTS OF
MORE SIGNIFICANT SNOW SHOWERS MOVE DONW THE EASTERN MOHAWK
VALLEY...THROUGH THE CAPITAL DISTRICT AND INTO THE TACONICS AND
BERKSHIRES. CURRENT FORECAST HAS THIS COVERED FAIRLY WELL AND HAVE
ONLY MADE ADJUSTMENTS TO THE TEMP GRIDS.
WITH THE SNOWBAND NEARLY DISIPATED EAST OF LAKE ONTARIO HAVE
CANCELLED THE LAKE EFFECT ADVISORIES AND WARNINGS EARLY (THEY WERE
DUE TO EXPIRE AT 100 PM.
.PREVIOUS DISCUSSION...
CLOUDS WILL BE A CHALLENGE TODAY AS 1000-850MB RH VALUES FROM THE
LATEST RUC13 CONTINUE TO SUPPORT RATHER HIGH VALUES FOR THE
SOUTHERN 2/3RDS OF THE CWA. HOWEVER...THE LOW LEVEL AGEOSTROPHIC
FLOW DOES INCREASE A BIT WHICH SHOULD ASSIST WITH THE DRIER AIR
AND EVENTUAL MECHANICAL MIXING FOR SOME BREAKS TO OCCUR INTO THE
CAPITAL REGION LATER THIS AFTERNOON. THE COLD ADVECTION TODAY
ALONG WITH THE CLOUD COVER AND A VERY LOW SUN ANGLE SHOULD KEEP
AFTERNOON HIGHS RATHER CHILLY INTO THE TEENS FOR THE TERRAIN AND
20S ELSEWHERE AS H850 TEMPS DROP BACK WELL INTO THE NEGATIVE TEENS
AND AROUND -20C FOR THE DACKS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
WINTER STORM WATCH FOR THE ENTIRE REGION...
EXTENSIVE COLLABORATION WITH NEIGHBORING WFOS AND WPC THIS MORNING
AS 00Z GUIDANCE IS SLOWLY COMING TO AN AGREEMENT WITH A
SIGNIFICANT IMPACT FROM THIS DEVELOPING WINTER STORM. THIS STORM
IS MORE OF A MILLER TYPE `B` AS REDEVELOPMENT WILL COMMENCE FROM
THE OHIO VALLEY SYSTEM TO THE MID ATLANTIC REGION.
THE MAIN PLAYER WITH THIS UPCOMING EVENT WAS SITUATED OVER THE
FOUR CORNERS REGION PER THE H2O VAPOR LOOP ANALYSIS.
MEANWHILE...PACIFIC MOISTURE WAS ADVANCING AHEAD OF THIS SYSTEM
ACROSS THE SOUTHERN PLAINS AND LOWER MISSISSIPPI RIVER VALLEY. A
POTENT UPPER JET WAS DIVING INTO THE NORTHERN TIER OF THE CONUS AS
THESE SYSTEMS WILL ATTEMPT TO PHASE OVER THE MID ATLANTIC INTO THE
NORTHEAST CORRIDOR ON SATURDAY.
THE AFOREMENTIONED ARCTIC FRONTAL BOUNDARY WILL BECOME QUASI-
STATIONARY ALONG OR JUST SOUTH OF THE NY STATE LINE TONIGHT WITH
BROAD ISENTROPIC LIFT EVOLVING OVER WESTERN AND CENTRAL NY. THIS
WILL SPELL OUT LIGHT SNOW DEVELOPING FROM WEST TO EAST AND COULD
EXTEND AS FAR EAST AS THE CATSKILLS OVERNIGHT. FOR THE REMAINDER
OF THE REGION...EXPECTING A MAINLY DRY OVERNIGHT AS THAT ARCTIC
DRY AIRMASS ADVECTS SOUTHWARD THROUGH THE HUDSON RIVER VALLEY.
OVERNIGHT LOWS WILL DROP WELL BELOW ZERO ACROSS THE DACKS WHERE
THE BETTER CHANCE FOR CLEARING SKIES AND TEENS ELSEWHERE AS THE
H850 TEMPS DROP TO BELOW -20C ACROSS THE NORTH AND NEGATIVE MID
TEENS ELSEWHERE.
IN FACT...THIS AGEOSTROPIC LOW LEVEL COMPONENT WHILE WEAK IN
MAGNITUDE IS RATHER PERSISTENT THROUGH THE DAY SATURDAY INTO
SATURDAY EVENING. THIS WILL KEEP THE PRECIP ALL SNOW AS ISENTROPIC
LIFT INCREASES AND LIGHT SNOW SPREADS ACROSS MOST THE REGION FROM
SOUTH TO NORTH THROUGH THE DAY. ACCUMULATIONS DURING SATURDAY WILL
LIKELY RANGE FROM AROUND 1 INCH ACROSS THE NORTHERN PORTIONS OF
THE REGION WITH AROUND 3 INCHES FOR THE SOUTH AND SOUTHWEST
PORTIONS OF THE REGION. HIGH TEMPERATURES WILL STRUGGLE TO GET OUT
OF THE TEENS.
SATURDAY NIGHT...THIS WILL BE THE MAIN EVENT FOR THE REGION AS
INCREASING LOW LEVEL SOUTH-SOUTHEAST JET GREATER THAN 50KTS
DEVELOPS AS SECONDARY DEVELOPMENT OF THE COASTAL LOW TAKES SHAPE.
THERE WILL BE AN ENHANCED REGION OF 2-D FGEN FORCING PER THE NCEP
MODEL SUITE ACROSS THE SOUTHERN AREAS /MAINLY JUST SOUTH OF THE
CAPITAL REGION/ WHERE SNOWFALL RATES COULD BE ENHANCED. THE
COMBINATION OF THIS SNOWFALL BAND AND THOSE WINDS COULD
POTENTIALLY BRING NEAR BLIZZARD CONDITIONS FOR THE HIGHER TERRAIN
FOR A PERIOD OF TIME. THE REMAINDER THE REGION...SNOW WILL BE
ONGOING WITH LATEST PLUME DIAGRAMS POINTING TOWARD 0.90" H2O
EQUIVALENT FROM THE GEFS/SREF. CROSS SECTIONS REVEAL THE BEST LIFT
FOR THE MOST OF THE REGION WILL OCCUR JUST BELOW THE BEST
DENDRITIC ICE GROWTH WHILE CLOSER TO THE 2D FGEN BANDS THAT WE
EFFECTIVELY TAP INTO THAT DENDRITIC ICE GROWTH. HERE...COULD SEE
SNOWFALL RATES APPROACHING UP TO 2 INCHES PER HOUR. THE ONLY SMALL
ISSUE TO THESE SNOWFALL RATES WILL BE THE DEGREE OF WARM AIR
ADVECTING NORTHWARD. SEEMS SOUTHERN PORTIONS OF DUTCHESS AND
LITCHFIELD COUNTIES COULD SEE A PERIOD OF SLEET/FZRA PER TOP-DOWN
THERMAL APPROACH FROM AN ENSEMBLE TREND OF THE NCEP MODELS.
SUNDAY...THE MAIN STORM CENTER NOW REFORMS AND INTENSIFIES OVER
THE GULF OF MAINE SUNDAY MORNING. THERE COULD BE A PERIOD OF THE
MOHAWK VALLEY CONVERGENCE PER CSTAR RESEARCH WHICH WILL NEED TO BE
MONITORED. OTHERWISE...SNOW WILL GRADUALLY DIMINISH IN COVERAGE
AND INTENSITY THROUGH THE DAY AS WE TRANSITION TO LIGHT SNOW
SHOWERS AND UPSLOPE FAVORED LOCATIONS FOR SOME ADDITIONAL SNOW
ACCUMULATIONS.
AT THE END OF THIS EVENT...COULD SEE VALUES OF 6-12 INCHES ACROSS
THE REGION HENCE THE WINTER STORM WATCH IN EFFECT FOR THE ENTIRE
REGION.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE DEPARTING WINTER STORM WILL CONTINUE TO LIFT NORTHEAST TOWARDS
ATLANTIC CANADA...WITH COLD CYCLONIC FLOW IN PLACE OVER THE
NORTHEASTERN US IN ITS WAKE. SOME LINGERING LAKE ENHANCED SNOW
SHOWERS WILL AFFECT THE WESTERN ADIRONDACKS AND WESTERN MOHAWK
VALLEY ON SUNDAY NIGHT WITH VERY COLD TEMPS...THANKS TO THE FRESH
SNOW COVER AND DIMINISHING WINDS. MOST AREAS LOOK TO DROP INTO THE
SINGLE DIGITS...WITH BELOW ZERO READINGS POSSIBLE OVER THE HIGH
TERRAIN...ESP IN THE ADIRONDACKS.
HIGH PRESSURE WILL PASS OVER THE REGION ON MONDAY...ALLOWING FOR DRY
WEATHER WITH BELOW NORMAL TEMPS. HIGHS WILL ONLY REACH THE TEENS TO
LOW 20S WITH PARTIAL SUNSHINE.
CLOUDS WILL QUICKLY INCREASE FOR MONDAY NIGHT AS A CLIPPER SYSTEM
DIVES FROM SOUTHERN CANADA TOWARDS THE GREAT LAKES. THERE IS GOOD
MODEL AGREEMENT THAT THIS SYSTEM WILL SLIDE ACROSS THE NORTHEAST FOR
LATE MONDAY NIGHT INTO TUESDAY. AS A RESULT...A SEVERAL HOUR PERIOD
OF LIGHT SNOW LOOKS TO MOVE ACROSS THE REGION. MOISTURE WILL BE
LIMITED...AND ANY SNOWFALL LOOKS TO BE LESS THAN ADVISORY LEVEL
AMOUNTS. TEMPS WILL CONTINUE TO BE VERY COLD...WITH SINGLE DIGITS
MONDAY NIGHT...AND MAINLY 20S ON TUESDAY.
BEHIND THIS SYSTEM...ANOTHER ROUND OF LAKE EFFECT SNOW LOOKS TO
IMPACT THE WESTERN ADIRONDACKS FOR TUESDAY NIGHT THROUGH WEDNESDAY
NIGHT. MEANWHILE...DRY WEATHER BUT BELOW NORMAL TEMPS WILL CONTINUE
ACROSS THE REMAINDER OF THE FORECAST AREA. MIN TEMPS TUESDAY NIGHT
WILL BE IN THE TEENS TO NEAR 20...WITH 20S TO LOW 30S DURING THE DAY
WEDNESDAY...AND TEENS AGAIN ON WED NIGHT.
THE LAKE EFFECT SHOULD SHUT OFF SOMETIME THURSDAY...AS A LARGE AREA
OF HIGH PRESSURE PASSES OVER THE AREA. SOME MODERATION IN TEMPS
WILL START TO OCCUR...AS A TROUGH BEGINS TO GET CARVED OUT ACROSS
THE WESTERN US AND RIDGING DEVELOPS ACROSS THE SOUTHEASTERN US. THIS
WILL PUT OUR REGION IN A SW FLOW ALOFT. TEMPS ON THURSDAY MAY
FINALLY REACH THE FREEZING MARK IN THE CAPITAL REGION...ALTHOUGH
HIGH TERRAIN AREAS WILL STILL BE IN THE 20S. THE WARMING TREND
APPEARS TO CONTINUE RIGHT INTO THE UPCOMING WEEKEND.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
VFR CONDITIONS ARE IN PLACE AT ALL TERMINALS THIS MORNING WITH SOME
SCT-BKN STRATOCU CLOUDS AROUND 4 KFT AND A BKN-OVC MID LEVEL DECK
AROUND 10 KFT.
DURING THE LATE MORNING TO EARLY AFTN HOURS...AN ARCTIC FRONTAL
BOUNDARY...AIDED BY SOME MOISTURE OFF LAKE ONTARIO...WILL PASS
THROUGH THE REGION FROM NORTH TO SOUTH. CONVERGENCE ALONG THIS
BOUNDARY MAY ALLOW FOR SOME SNOW SHOWERS OR SQUALLS ACROSS THE
REGION. THE BEST CHANCE WILL BE FOR KALB/KPSF...AS THE SNOW SHOWERS
MAY PASS DOWN THE MOHAWK VALLEY AND TOWARDS THE CAPITAL
REGION/BERKSHIRES. WE HAVE INCLUDED A TEMPO TO ACCOUNT FOR THIS
POSSIBILITY FOR A BRIEF PERIOD OF IFR CONDITIONS WITHIN SNOW
SHOWERS/SQUALLS DURING THE LATE MORNING/EARLY AFTN. OUTSIDE OF SNOW
SHOWERS...CIGS WILL BE BKN AROUND 4 KFT DURING THE LATE MORNING TO
AFTN HOURS. CLOUDS SHOULD START TO CLEAR BY THIS EVENING WITH JUST
FEW-SCT LOW CLOUDS AND SOME PASSING CIRRUS OVERNIGHT.
WINDS WILL BE S-SW AHEAD OF THE BOUNDARY...BECOMING WESTERLY AT
AROUND 10 KTS THIS MORNING. BEHIND THE BOUNDARY...WINDS WILL BE
W-NW AT 10-15 KTS WITH A FEW HIGHER GUSTS...ESP AT
KALB/KPSF...WHERE WINDS MAY GUST AS HIGH AS 25 KTS. WINDS WILL
DIMINISH THIS EVENING WITH THE LOSS OF DAYTIME HEATING...AND WILL BE
NW OVERNIGHT AT 10 KTS OR LESS.
OUTLOOK...
SATURDAY-SUNDAY: HIGH OPERATIONAL IMPACT. DEFINITE SN.
SUNDAY NIGHT-MONDAY: NO OPERATIONAL IMPACT. NO SIG WX.
MONDAY NIGHT-TUESDAY: MODERATE OPERATIONAL IMPACT. CHANCE OF SHSN.
&&
.HYDROLOGY...
NO HYDRO RELATED CONCERNS ARE EXPECTED THROUGH EARLY NEXT WEEK.
MAINLY SNOW WILL FALL THIS WEEKEND AND TEMPERATURES WILL BE WELL
BELOW NORMAL AND ICE WILL CONTINUE TO FORM ON AREA RIVERS...STREAMS
AND PARTICULARLY LAKES THROUGH EARLY NEXT WEEK.
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...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR CTZ001-013.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ032-033-038>043-047>054-058>061-063>066-
082>084.
MA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR MAZ001-025.
VT...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR VTZ013>015.
&&
$$
SYNOPSIS...BGM
NEAR TERM...GJM/BGM
SHORT TERM...BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
HYDROLOGY...BGM
FOR THE LATEST UPDATES...PLEASE VISIT OUR WEBPAGE AT
WWW.WEATHER.GOV/ALBANY
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
320 PM CST FRI DEC 13 2013
.DISCUSSION...
319 PM CST
SHORT TERM...TONIGHT THROUGH SATURDAY NIGHT...
NOT MUCH HAS CHANGED WITH THE CURRENT THINKING FOR TONIGHT AND
SATURDAY REGARDING SNOWFALL AMOUNTS AND PLACEMENT. THE CURRENT
WATER VAPOR IMAGERY CONTINUES TO INDICATE A DECENT DISTURBANCE
NEAR THE TEXAS PANHANDLE EARLY THIS AFTERNOON...WITH SEVERAL LEAD
DISTURBANCES ACROSS OK AND INTO WESTERN MO. PROFILER AND VWP DATA
ACROSS THE SOUTHERN PLAINS AND MID MISSISSIPPI VALLEY INDICATES
THAT AROUND 30KT OF SOUTHWESTERLY FLOW AROUND 850 MB HAS DEVELOPED
IN ASSOCIATION WITH THIS SYSTEM. THIS IS ALLOWING FOR SOME DECENT
MOISTURE TRANSPORT AND ISENTROPIC ASCENT ACROSS THE MISSOURI AND
WEST CENTRAL ILLINOIS THIS AFTERNOON. THIS HAS PRODUCED A GOOD
AREA OF PRECIPITATION ACROSS MISSOURI...ESPECIALLY ALONG THE
LEADING EDGE OF THE BETTER MOISTURE TRANSPORT.
I EXPECT THIS AREA OF PRECIP TO CONTINUE TO MOVE NORTHWARD AND TO
OVERSPREAD MOST AREAS ALONG AND SOUTH OF INTERSTATE 80 THROUGH THE
EVENING AS THE BETTER MOISTURE GETS DRAWN NORTHWARD IN ASSOCIATION
WITH THE APPROACHING SOUTHERN STREAM SYSTEM. IT APPEARS LIKELY THAT
A BAND OF MODERATE TO HEAVY SNOW WILL SET UP THIS EVENING ACROSS MY
SOUTHERN COUNTIES...IN ASSOCIATION WITH A DEVELOPING BAND OF
FRONTOGENESIS. THE ENHANCED FORCING FOR ASCENT WITHIN THE
FRONTOGENETIC CIRCULATION WILL ALLOW FOR SOME DECENT ASCENT WITHIN
THE DENDRITIC GROWTH ZONE. THIS ALONG WITH THE FACT THAT STEEP LAPSE
RATES AND -EPV EXITS WITHIN AND ABOVE THIS ZONE ALSO SUGGESTS THAT
THEIR WILL BE SOME FAIRLY EFFICIENT SNOWFALL PRODUCTION WITHIN THIS
BAND OF SNOW. WITH THIS IN MIND...IT APPEARS THAT SNOWFALL RATES
COULD APPROACH 1 INCH PER HOUR FOR A COUPLE HOUR PERIOD THIS
EVENING...ESPECIALLY TO THE SOUTH OF INTERSTATE 80 WITHIN AND NEAR
THE CURRENT WINTER STORM WARNING.
A SECOND AREA OF SNOW WILL BE FAVORED...MAINLY ACROSS SOUTHERN
WISCONSIN THIS EVENING AS A SECONDARY AXIS OF FRONTOGENESIS DEVELOPS
ALONG A BAROCLINIC RIBBON...AND COMBINES WITH INCREASING FLOW AND LOW
LEVEL CONVERGENCE OFF OF LAKE MICHIGAN. HOWEVER...MOST HIGH RES
GUIDANCE CONTINUES TO FAVOR AREAS NORTH OF THE ILLINOIS BOARDER.
THEREFORE...IT APPEARS MOST OF NORTHERN ILLINOIS WILL REMAIN SNOW
FREE...THROUGH AT LEAST MID TO LATE EVENING.
THE SNOW SHOULD BEGIN TO SPREAD NORTHWARD BY LATE THIS EVENING...AND
BEGIN IMPACTING MOST OF NORTHERN ILLINOIS BY OR SHORTLY AFTER
MIDNIGHT AS THE SURFACE INVERTED TROUGH BECOMES ORIENTED NORTH TO
SOUTH ACROSS THE AREA OVERNIGHT. THE SNOW WILL CONTINUE INTO
SATURDAY AS SOME LARGER SCALE SUPPORT FOR ASCENT OVERSPREADS THE
AREA IN ASSOCIATION WITH THE APPROACHING NORTHERN STREAM SHORT WAVE.
THIS COULD EVEN LEAD TO A BIT IN AN UPTICK TO THE SNOWFALL
INTENSITY...PARTICULARLY ACROSS EASTERN ILLINOIS AND NORTHWESTERN
INDIANA...WHERE MID LEVEL DEFORMATION WILL CONTINUE IN ASSOCIATION
WITH THE MID LEVEL CIRCULATION. THE SNOW WILL GRADUALLY END ACROSS
NORTHERN ILLINOIS AS THE FLOW TURNS NORTHWESTERLY. SOME LINGERING
LAKE EFFECT SNOW SHOWERS ARE POSSIBLE ACROSS NORTHWESTERN INDIANA
INTO SATURDAY EVENING.
THERE ARE SOME POSSIBILITIES FOR SOME LAKE ENHANCEMENT FOR AREAS
NEAR THE LAKE LATE TONIGHT AND INTO SATURDAY AS THE FLOW TURNS EAST
NORTHEASTWARD. HOWEVER...THERMODYNAMICS OVER THE LAKE DO NOT APPEAR
TO BE VERY FAVORABLE FOR ANY SIGNIFICANT LAKE ENHANCEMENT POTENTIAL.
DELTA T`S LOOK TO REMAIN AROUND 12 DEGREES CELSIUS AND EQUILIBRIUM
LEVELS NEVER APPEAR TO REACH INTO THE DENDRITIC GROWTH ZONE.
SO...OVERALL...IT STILL APPEARS SNOWFALL AMOUNTS WILL RANGE FROM
ABOUT 5 TO 8 INCHES ACROSS THE WARNING AREA...3 TO 6 INCHES IN THE
ADVISORY AREAS...AND 2 TO 3 INCHES AROUND NORTHEASTERN
ILLINOIS...AND AN INCH OR LESS ACROSS NORTH CENTRAL ILLINOIS.
ONCE THE SNOW ENDS...THE NORTHWESTERLY FLOW WILL ALLOW COLDER AIR
TO SPILL BACK ACROSS THE REGION SETTING UP ANOTHER COLD SUNDAY
MORNING.
KJB
MEDIUM-LONG RANGE...SUNDAY THROUGH NEXT FRIDAY...
HIGHLIGHTS OF THE MEDIUM-LONG RANGE FORECAST PERIOD ARE CONTINUED
NORTHWEST UPPER FLOW WITH A PARADE OF WEAK CLIPPER SYSTEMS INTO
MID-WEEK...THEN A SHIFT TOWARD SOUTHWEST FLOW ALOFT MID/LATE NEXT
WEEK AS UPPER RIDGE BUILDS ACROSS THE EASTERN PACIFIC AND GULF OF
ALASKA AND INDUCES DOWNSTREAM LONG WAVE TROUGH ACROSS WESTERN NORTH
AMERICA. THIS WILL SUPPORT A TRANSITION FROM BELOW NORMAL TEMPS
SUN-WED...WITH THE POTENTIAL FOR A BRIEF WARM-UP THURS-EARLY FRI
AHEAD OF WESTERN TROUGH.
SUNDAY THROUGH WEDNESDAY...
MID-LEVEL SHORT WAVE TROUGH AXIS ASSOCIATED WITH EARLY WEEKEND
WINTER STORM WILL BE WELL EAST OF THE REGION BY SUNDAY MORNING.
MID/UPPER LEVEL LOW OVER DEVELOPS OVER ONTARIO AND THE NORTHERN
LAKES HOWEVER...WITH REGION OF ENHANCED NORTHWEST FLOW ALOFT FROM
THE NORTHERN PLAINS TO THE MIDWEST. SEVERAL MINOR AMPLITUDE RIPPLES
ARE INDICATED IN MODEL GUIDANCE WHICH PROPAGATE ALONG LOW LEVEL
BAROCLINIC ZONE WHICH STRETCHES NORTHWEST-SOUTHEAST ACROSS THE
REGION. SOME TIMING DIFFERENCES WITH THE MORE SUBTLE DISTURBANCES
BETWEEN MODELS...THOUGH IT APPEARS A WEAK WAVE WILL TRAVERSE THE
AREA SUNDAY WITH A SOMEWHAT BETTER DEFINED VORT MOVING OVER THE AREA
SUNDAY NIGHT AND EARLY MONDAY. FORECAST SOUNDINGS AND TIME/HEIGHT
DEPICTIONS INDICATE GENERALLY DRY MOISTURE PROFILES...WITH ONLY A
POCKET OF DEEPER MID-LEVEL MOISTURE SUNDAY NIGHT-EARLY MONDAY WITH
ISENTROPIC FORCING AHEAD OF THE STRONGER WAVE. THUS THE BEST
POTENTIAL FOR A LITTLE LIGHT SNOW APPEARS BE SUNDAY NIGHT...THOUGH
WITH LITTLE ACCUMULATION EXPECTED (A DUSTING TO PERHAPS A HALF INCH)
AS LIFT APPEARS GENERALLY WEAK AND WELL BELOW THE DENDRITIC GROWTH
ZONE. WEAK ASCENT LINGERS INTO MONDAY...ESPECIALLY ACROSS THE
NORTHEAST/EAST PARTS OF THE CWA WITH THE LEFT EXIT REGION OF THE
UPPER JET STREAK HELPING TO MAINTAIN SOME LARGE SCALE SUPPORT DURING
THE DAY. A MORE AMPLIFIED SHORT WAVE IS PROGGED TO DIG ACROSS THE
WESTERN GREAT LAKES REGION ON TUESDAY...THOUGH THE BEST WARM
ADVECTION AND ISENTROPIC UPGLIDE APPEARS TO REMAIN JUST TO THE
NORTH/NORTHEAST OF THE CWA...THOUGH A REINFORCING PUSH OF COLDER AIR
DOES ARRIVE TUESDAY NIGHT WITH A COLD FRONT.
COLDEST CONDITIONS LOOK TO OCCUR SUNDAY BEHIND THE EARLY WEEKEND
WINTER STORM...WITH HIGHS IN THE TEENS AND LOWS IN THE SINGLE DIGITS
TO AROUND 10 ABOVE. SOME MODERATION OCCURS MON-TUE WITH THE WEAK BUT
NEARLY PERSISTENT WARM ADVECTION ASSOCIATED WITH THE AFOREMENTIONED
CLIPPERS. A LITTLE COOLER TUESDAY NIGHT-WEDNESDAY BEHIND TUESDAY
NIGHTS COLD FRONT.
AS INDICATED ABOVE...DEVELOPING UPPER RIDGING OVER THE EAST PACIFIC
AND TROUGH INDUCEMENT OVER THE WESTERN CONUS WEDNESDAY-THURSDAY
RESULTS IN SURFACE LOW PRESSURE DEVELOPMENT OVER THE PLAINS BY EARLY
THURSDAY. FAIRLY DECENT MODEL AGREEMENT IN THIS LOW DEEPENING AND
LIFTING NORTHEAST ACROSS MINNESOTA AND THE NORTHERN GREAT LAKES
THURSDAY AND THURSDAY NIGHT...PLACING WFO LOT CWA IN THE WARM SECTOR
AS WARM FRONT LIFTS NORTH. SHALLOW COLD SURFACE LAYER MAY RESULT IN
A LITTLE MIXED PRECIPITATION THURSDAY MORNING ESPECIALLY NORTH AS
WARMING OCCURS MORE VIGOROUSLY ALOFT...THOUGH GFS/ECMWF RUNS
INDICATE THAT LOW LEVELS WARM ENOUGH TO PRODUCE MAINLY RAIN BY
THURSDAY EVENING/NIGHT. SOME TIMING DIFFERENCES DO ARISE WITH THE
NEW 12Z ECMWF (THE 00Z RUN WAS IN BETTER AGREEMENT WITH THE 00/12Z
GFS AND ENSEMBLE MEMBERS)...WITH THE ECMWF FASTER WITH THE LOW
LIFTING ACROSS THE NORTHERN LAKES EARLY FRIDAY AND BRINGING THE
TRAILING COLD FRONT THROUGH FASTER. CONTINUE TO FAVOR A SLIGHTLY
SLOWER SOLUTION SIMILAR TO THE 00Z EC/12Z GFS AND GEFS RUNS. THIS
WOULD SUPPORT TEMPS POTENTIALLY WARMING INTO THE 35-40 F RANGE
THURSDAY AND POTENTIALLY INTO THE 40S/EVEN 50 ACROSS THE SOUTHEAST
FRIDAY PRIOR TO COLD FRONTAL PASSAGE. PRECIP POTENTIAL APPEARS TO BE
GREATEST ALONG/AHEAD OF THE COLD FRONT INTO FRIDAY. DECREASING
THICKNESSES IN COLDER AIR BEHIND THE FRONT PORTEND A CHANGE BACK TO
SNOW FROM THE WEST FRIDAY.
THINGS LOOK POTENTIALLY INTERESTING JUST BEYOND THE END OF DAY
7...AS SOUTHWEST-NORTHEAST ORIENTED BAROCLINIC ZONE COULD BECOME THE
FOCUS FOR A COUPLE OF ROUNDS OF WINTRY PRECIP SOMEWHERE FROM HERE
INTO THE OHIO VALLEY...WHILE HIGH PRESSURE AND A RETURN TO
SUB-AVERAGE TEMPS BUILD BACK ACROSS THE UPPER MIDWEST.
RATZER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 18Z...
* ONSET TIMING OF SNOW TONIGHT AND PERIOD OF GREATEST INTENSITY
OVERNIGHT ALONG WITH MAGNITUDE OF RESULTING VISIBILITY
RESTRICTION.
* TIMING OF DETERIORATION FROM VFR TO LIFR THIS EVENING AND
IMPROVEMENT BACK TO MVFR SAT AFTERNOON.
* VELOCITY OF E TO NE WIND.
TRS
//DISCUSSION...UPDATED 18Z...
SIGNIFICANT UPPER DISTURBANCE OVER THE SOUTHERN ROCKIES AND
SOUTHERN HIGH PLAINS LATE THIS MORNING IS FORECAST TO CONTINUE TO
MOVE E ACROSS THE PLAINS TO THE CENTRAL AND LOWER MO VALLEY BY
12Z SAT...AND THEN ON TO THE UPPER MIDWEST AND MID MS VALLEY BY
15/00Z. ASSOCIATED SURFACE LOW TO TRACK SE FROM KS TO THE LOWER
MS VALLEY BY SAT MORNING AND THEN E ACROSS THE DEEP S DURING THE
DAY. MEANWHILE...A SECOND LOW IS TO DEVELOP IN THE PLAINS AND
REACH THE MID MS VALLEY BY 12Z...CONTINUING UP THE OH VALLEY
DURING THE DAY.
PER 12Z RAOBS A STRONG BAROCLINIC ZONE WAS FROM THE CANADIAN
ROCKIES ESE ACROSS THE FAR NORTHERN PLAINS AND THE UPPER MIDWEST
AND THROUGH THE GREAT LAKES INTO THE NE STATES /850HPA TEMP OF
-23C AT INL AND +7C AT SGF/. MODELS INDICATE THAT AS THE STORM
SYSTEM MOVES E TODAY AND TONIGHT THAT THE BAROCLINIC ZONE WILL
SHIFT S AS COLD AIR ADVECTION CONTINUES OVER THE GREAT LAKES AND
THE NORTHERN PORTION OF THE UPPER MIDWEST WHILE STRONG WARM AIR
ADVECTION SPREADS FROM THE LOWER MO VALLEY TO THE MID MS VALLEY
AND THEN ACROSS THE OH VALLEY AND MIDWEST.
MID LEVEL MOISTURE AS WELL AS LOWER LEVEL MOISTURE /12Z 700HPA
DEW POINT DEPRESSION OF 1 DEG C AT OUN AND FWD...850HPA
DEPRESSION OF 0-1 DEG C AT CRP AND FWD/ IS PROGGED TO RAPIDLY
STREAM N AND NE FROM THE SOUTHERN PLAINS AHEAD OF THE APPROACHING
SYSTEM. MVFR CEILINGS HAD ALREADY SPREAD AS FAR NE AS IRK AND
QUN AT MIDDAY. AS THIS MOISTURE CONTINUES TO MOVE INTO AND
OVERSPREAD THE LOCAL AREA THIS EVENING CEILINGS ARE ANTICIPATED TO
DROP FROM VFR THROUGH MVFR AND IFR TO LIFR DURING THE MID AND LATE
EVENING.
ALONG WITH THE ARRIVAL OF DEEP MOISTURE WILL BE UPWARD MOTION
INCREASING IN BOTH DEPTH AND STRENGTH THROUGH THE COLUMN AS
INS ENTROPIC UPGLIDE/Q-VECTOR CONVERGENCE/FRONTOGENESIS INCREASES
AND EXPECT LIGHT SNOW TO BEGIN LOCALLY AROUND 03Z AND INTENSIFY BY
06Z WITH A PERIOD OF MODERATE SNOWFALL OCCURRING OVERNIGHT CAUSING
INCREASING REDUCTION IN VISIBILITY. WITH THE SURFACE LOW TO TRACK
FROM CENTRAL MO NE TO NORTHERN IN OVERNIGHT AND SAT MORNING THE
LOCAL AREA LOOKS TO BE MORE ON THE NORTHERN EDGE OF THE SNOWFALL
WITH THE BAND OF HEAVIER SNOW ACROSS CENTRAL IL TO CENTRAL AND
NORTHERN IN.
THERE MAY BE SOME LAKE ENHANCEMENT TO THE SNOWFALL OVERNIGHT
TONIGHT INTO EARLY SAT AFTERNOON BUT ANY SIGNIFICANT LAKE EFFECT
SNOW IS EXPECTED TO BE OCCURRING IN NW IN AS THE LOW LEVEL FLOW
VEERS FROM NE TO N.
CONDITIONS TO IMPROVE SAT DURING THE LATER MORNING AND THE
AFTERNOON AS THE SURFACE AND 850HPA LOWS MOVE E TO OH...AND THE
UPPER TROUGH AXIS REACHES LAKE MI AND LOWER OH VALLEY BY 15/00Z.
WINDS LOCALLY DO NOT LOOK TO BE PARTICULARLY STRONG WITH THIS
SYSTEM...GENERALLY IN THE 8-12KT RANGE REST OF TODAY THROUGH THE
DAY SAT WHILE WINDS BACK FROM OUT OF THE E TO THE NE.
TRS
//ORD AND MDW CONFIDENCE...UPDATED 20Z...
* HIGH CONFIDENCE IN WIND FCST.
* MEDIUM CONFIDENCE IN TIMING OF ONSET...THE PERIOD OF GREATER
INTENSITY...AND ENDING TIME.
* MEDIUM CONFIDENCE IN TIMING OF DETERIORATION FROM VFR TO LIFR.
TRS
//OUTLOOK FOR ORD/MDW FOR 00Z SUNDAY-12Z FRIDAY...UPDATED 12Z...
SATURDAY NIGHT...MAINLY VFR. PERIOD OF MVFR CIGS EARLY EVENING
WITH LIGHT SNOW/FLURRIES ENDING.
SUNDAY-MONDAY...SLIGHT CHC OF SNOW AND MVFR.
TUESDAY-WEDNESDAY...MAINLY VFR
THURSDAY...VFR. POSSIBLE PERIOD OF LGT WINTRY MIX.
BEACHLER
&&
.MARINE...
144 PM CST
A LARGE AREA OF HIGH PRESSURE IS SETTLING OVER THE SERN CONUS AS WEAK
LOW PRESSURE MOVING ACROSS NRN NEW ENGLAND DAGS A COLD FRONT DOWN
LAKE MICHIGAN. THE FRONT HAS STALLED OUT OVER THE SOUTHERN TIP OF
THE LAKE LEADING TO LIGHT AND VARIABLE WINDS OVER THE SOUTHERN TIP
OF THE LAKE. NORTH WINDS ARE STRENGTHENING OVER THE NORTHERN
PORTIONS OF THE LAKE AS ANOTHER AREA OF ARCTIC HIGH PRESSURE BUILDS
OUT OF CANADA AND SPREADS ACROSS THE NRN PLAINS AND UPPER GREAT
LAKES. THE FRONT OVER THE SRN PORTIONS OF THE LAKE WILL WASH OUT AS
A DOUBLE BARRELED LOW PRESSURE SYSTEM DEVELOPS OVER THE SRN AND
CNTRL PLAINS. THE COMPLEX LOW PRESSURE SYSTEM WILL TRACK EWD THIS
EVENING WITH ONE CIRCULATION CENTER TRACKING THROUGH CNTRL IL AND
ANOTHER TRACKING THROUGH THE LOWER MISSISSIPPI VALLEY. A WEAK
INVERTED SFC TROUGH AXIS ASSOCIATED WITH THE MORE NORTHERN OF THE
TWO LOWS WILL MOVE ACROSS THE LAKE EARLY TOMORROW. AS THE HIGH
BUILDS ACROSS THE UPPER GREAT LAKES THIS EVENING...WINDS OVER THE
ENTIRE LAKE WILL GRADUALLY TURN EASTERLY...BUT AS THE INVERTED
TROUGH AXIS CROSSES THE LAKE TOMORROW...WINDS OVER THE LAKE WILL
GRADUALLY BACK THROUGH NELY TO NORTHERLY TOMORROW EVENING AND THEN
THEN CONTINUE TO BACK TO NWLY BY LATE SATURDAY NIGHT AND EARLY
SUNDAY MORNING. AS COLDER AIR ASSOCIATED WITH THE ARCTIC HIGH IS
DRAWN OVER THE LAKE...THE STRONG COLD ADVECTION AND STRENGTHENING
PRESSURE GRADIENT WILL LEAD TO WINDS INCREASING TO AROUND 30KT
THROUGH THE DAY ON SUNDAY. WHILE GALES ARE NOT EXPECTED AT THIS
TIME...THE STRONG WINDS AND COLDER AIR WILL LEAD TO A CHANCE FOR
LIGHT TO MODERATE FREEZING SPRAY ON SUNDAY. THE BRISK NWLY WINDS
WILL PERSIST THROUGH SUNDAY NIGHT...AND THEN ANOTHER HIGH WILL BUILD
ACROSS LAKE MICHIGAN ON MONDAY...ALLOWING WINDS TO TEMPORARILY
SUBSIDE. AS THE HIGH MOVES OFF TO THE EAST ON TUESDAY...ANOTHER LOW
WILL TRACK ACROSS SCNTRL CANADA...LEADING TO INCREASING SWLY-WLY
WINDS BY TUESDAY...WHICH SHOULD PERSIST THROUGH THE MIDDLE OF NEXT
WEEK.
KREIN
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...WINTER STORM WARNING...ILZ033-ILZ039 UNTIL NOON SATURDAY.
WINTER WEATHER ADVISORY...ILZ019-ILZ021-ILZ022-ILZ023-ILZ032
UNTIL NOON SATURDAY.
WINTER WEATHER ADVISORY...ILZ014...10 PM FRIDAY TO 6 PM SATURDAY.
IN...WINTER WEATHER ADVISORY...INZ001-INZ002 UNTIL NOON SATURDAY.
WINTER STORM WARNING...INZ010-INZ011-INZ019 UNTIL NOON SATURDAY.
LM...SMALL CRAFT ADVISORY...LMZ740...MIDNIGHT SATURDAY TO 3 PM
SATURDAY.
SMALL CRAFT ADVISORY...LMZ741-LMZ742-LMZ743...3 AM SATURDAY TO 3
PM SATURDAY.
&&
$$
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Area Forecast Discussion
National Weather Service Lincoln IL
216 PM CST Fri Dec 13 2013
.DISCUSSION...
ISSUED 205 PM CST Fri Dec 13 2013
Clouds continue to lower and thicken this afternoon ahead of the winter
storm system expected to affect our area tonight into Saturday. Already
seeing some light rain and sleet pushing into extreme southwest IL early
this afternoon as the upper level wave tracks across the southern Plains.
SHORT TERM...Tonight through Monday
Significant snowfall expected over parts of central through east
central Illinois tonight thru Saturday morning...but not much in
the way of strong winds with this particular storm system.
The main forecast challenge this period will be with snowfall totals
starting tonight thru early Saturday afternoon. Will continue to hold
on to the winter weather advisory with a few locations across central
thru east central Illinois edging close to 6 inches by the time the
snow tapers off to flurries Saturday afternoon. Forecast soundings,
at least for a few hours late this afternoon into early this evening,
continues to suggest a brief period of rain, sleet and possibly some
freezing rain over parts of west central Illinois before we see the
lower layers saturate and cool sufficiently enough to support mostly
snow thru the overnight hours. NAM-WRF time height cross sections
indicate the best forcing coupled with the deeper moisture/and dendritic
growth zone will be mainly tonight thru about 14z Saturday. Using a
13:1 SLR indicates 4 to 6 inches will be common across the area by the
time the snow diminishes on Saturday.
Still a bit concerned about the potential for banding, especially
along the inverted trof, which is expected to push across our area
early Saturday morning. Several of the hi-res models suggest the
threat is there but unfortunately, are not very consistent in depicting
the location. Past few runs of the HRRR have indicated one band to move
north across the area this evening, with a break over parts of central
thru east central IL around midnight, before another band pushes
acrs the area towards morning with the inverted trof. Wouldn`t at all
be surprised to see a few areas with 6 to 8 inches accumulation by late
Saturday morning, but at this time, the threat appears too isolated.
Models are a bit more consistent in showing an increase in snow totals
just to our east as the weak surface low and inverted trof shift off
to our east and we see a better coupled 250mb jet structure and
associated upper level divergence.
The upper level wave and surface reflection should push well off
to our east by late tomorrow afternoon with all of the precip shifting
out of the forecast area. The weather should be on the quiet side for
the rest of the short term period with a brief cool down in the wake
of the winter system Saturday night through Sunday night before we see
milder temperatures move into our area early next week.
LONG TERM...Tuesday through Friday
Medium range models indicate some fast moving waves approaching
our area from the northwest at the start of this forecast period
with little in the way of moisture available to produce much in
the way of precip in our area. The first such wave will move across
the lower Great Lakes on Monday with a hint for some very light
precip during the day, mainly to our north. The next wave moves
quickly southeast along the tight 850 mb baroclinic zone on Tue,
at least according to the latest ECMWF, with again little in the
way of moisture to work with. Will continue to keep the first part
of the week dry but could see some low chance pops added in later
forecasts.
Warmer temperatures expected in the Wed-Fri time frame as a deep
upper level trof drops southeast into the southern Rockies and
brings about a strong southwest flow aloft over our area. This
should result in mild temps, at least compared to what we have
been experiencing, through the end of the week. However, as the
deep upper level trof edges east into the central Plains, a strong
Arctic cold front will approach our area on Friday increasing the
precip chances Thursday night into Friday, followed by much colder
weather for next weekend.
Smith/07
&&
.AVIATION...
ISSUED 1159 AM CST Fri Dec 13 2013
Shield of mixed precipitation moving ne across MO nearing the MS
river at noon and will spread ne to SPI around 20Z/2 pm, DEC by
21Z/3 pm and I-74 TAF sites of PIA, BMI & CMI between 22Z-23Z/4-5 pm.
Precipitation should mainly fall as snow, but will begin as a
period of mixed precipitation with sleet, rain and freezing rain
especially sw TAF sites this afternoon. Moderate to even bands of
heavy snow to set up this evening and continue overnight. VFR
conditions early this afternoon to deteoriate during 2nd half of
afternoon into this evening with LIFR/IFr conditions setting in
with the widespread snow. Snow will diminish from west to east
during 15Z-18Z Sat with MVFR vsbys and IFR-low end MVFR ceilings.
SSE winds 7-10 kts to turn ENE this evening and north Sat morning.
Deepening 1005 mb low pressure along the NM/OK border to weaken to
1010 mb over south central KY by 18Z/noon Sat with an inverted trof
extending into IL/IN.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until Noon CST Saturday FOR ILZ038-
042>046-051>057-061>063-066>068-071>073.
WINTER WEATHER ADVISORY until 6 AM CST Saturday FOR ILZ027>031-
036-037-040-041-047>050.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
1204 PM CST Fri Dec 13 2013
...Updated aviation section...
.SYNOPSIS...
ISSUED AT 242 AM CST FRI DEC 13 2013
The center of an upper low was moving across Arizona overnight as
observed on water vapor imagery. Just upstream was a broad area of
positive vorticity advection across new Mexico into the panhandles,
where the leading edge of the upper jet was also located. Very weak
pressure falls were occurring and were widespread from the northern
High Plains region of Wyoming and Nebraska to north central Texas.
METAR objective analysis indicated warm surface frontogenesis was
developing from southeast Colorado into western Oklahoma. An
extremely dry 00 UTC KDDC sounding was likely contributing to a
pronounced lack of radar precipitation echoes advancing any farther
than the Oklahoma/Kansas line near Coldwater and Medicine lodge.
Surface temperatures around 1 am were steady to slowly warming south
and east of Dodge city.
&&
.SHORT TERM...(Today and tonight)
ISSUED AT 242 AM CST FRI DEC 13 2013
The last run of the NAM and recent HRRR models appeared to represent
the thermodynamic and precipitation areal coverage very well by
keeping extremely low precipitation/QPF accumulations mainly across
western Oklahoma into areas of western Kansas east of Medicine
Lodge. Even with the advancing upper system from the southern
Rockies, the isentropic fields indicate an increasingly downslope
profile after about 09-12 UTC.
The WRF model is still having problems with ground snow across the
I-70 corridor, which hasn`t existed for a few days. However the
solution is probably not bad farther south and west where it
forecasts temperatures as high as around 50 degrees. As the pressure
falls persist, a surface low will develop southeastward into the
panhandles this afternoon. The local GFS mos products forecast
stronger surface winds behind the attendant surface cold frontal
boundary later into Friday night especially toward midnight. This is
a reasonable solution as the surface low will move rapidly across
the southern plains and the upper trough swings across the region
just in time to add to a deep subsident profile for western
Kansas.
.LONG TERM...(Saturday through Thursday)
ISSUED AT 242 AM CST FRI DEC 13 2013
A significant Arctic outbreak is the offing coming up next Thursday
or Friday time frame. As with many Arctic events, the long range
models struggle with the timing and normally are too slow with these
Arctic fronts. Current long range model trends are suggesting a bit
slower solution to the Arctic fropa, but like mentioned above they
do not normally pan out that way. Current thoughts are a frontal
passage around Thursday afternoon. There may be a strong temperature
contrast by Thursday afternoon from Hays to Medicine Lodge. Current
high temps from the mid 40s around Hays to the low to mid 50s in the
Medicine Lodge area may need significant adjustment downward if a
faster solution bears out. Some light snow is also possible into
next weekend of December 21st and 22nd, however should be light
accumulations.
Ahead of the Arctic front, from Saturday into Wednesday, a warming
trend begins Sunday with temperatures rising from the low to mid 40s
on Saturday behind a cold front, and into the 50s through Wednesday.
A cold upper trough will be moving across the Plains on Saturday
followed by dry northwest flow aloft and downslope and warmer
surface winds. Overnight lows look to gradually warm from the low to
mid 20s on Saturday night into the upper 20s into Wednesday night.
&&
.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
ISSUED AT 1200 PM CST FRI DEC 13 2013
North winds will continue in the wake of a departing low pressure
system this afternoon through Saturday. Wind speeds will generally
be in the 12 to 15 knot range tonight given a moderately strong
pressure gradient. VFR conditions will be found as subsidence
prevails across western Kansas.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 21 43 23 54 / 0 0 0 0
GCK 20 46 21 53 / 0 0 0 0
EHA 23 46 24 53 / 0 0 0 0
LBL 22 46 24 54 / 0 0 0 0
HYS 17 39 21 53 / 10 0 0 0
P28 22 40 22 54 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...Russell
SHORT TERM...Russell
LONG TERM...Kruse
AVIATION...Umscheid
AREA FORECAST DISCUSSION
NWS CARIBOU ME
1210 PM EST FRI DEC 13 2013
.SYNOPSIS...
WEAK LOW PRESSURE WILL MOVE EAST OF THE REGION THIS AFTERNOON
ALLOWING A REINFORCING SHOT OF VERY COLD AIR TO FOLLOW FOR TONIGHT
THROUGH SATURDAY. LOW PRESSURE WILL APPROACH FROM THE SOUTH
SATURDAY NIGHT...AND PASS JUST SOUTHEAST OF THE REGION
SUNDAY...POTENTIALLY BRINGING SIGNIFICANT SNOWFALL TO MUCH OF THE
AREA.&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 1200L: RADAR SUGGESTS SOME SNOW STREAMERS BEGINNING TO DVLP
ACROSS NRN MAINE W/ THESE ORIENTED WNW-ESE AS CAA BEGINS BEHIND
THIS MORNING/S WEAK CLIPPER WHICH IS NOW WELL E OF THE AREA. FOCUS
FOR THE REMAINDER OF THIS AFTN WILL BE ON THESE W/ BITTER WND
CHILLS THEN THE ISSUE FOR TNGT AS A BITTER COLD REINFORCING SHOT
OF ARCTIC AIR OVERSPREADS THE AREA. MADE A MINOR ADJUSTMENT TO
POPS TO BETTER FIT CURRENT AND EXPECTED CONDS. OTHERWISE...CURRENT
FCST ON TRACK...
UPDATE 0905L: WEAK CLIPPER NOW E OF THE AREA W/ AREA OF VRY LGT
SNW E INTO NB AS WELL... CAA COMMENCING ONCE AGAIN ACROSS THE AREA
ATTM BEHIND THIS SYSTEM AND THIS WILL REINFORCE THE VRY COLD
AIRMASS WHICH HAS SETTLED OVR THE AREA LAST FEW DYS. BRISK NW FLOW
WILL ALSO LIKELY TOUCH OFF A FEW STREAMERS OFF OF THE ST LAWRENCE
THIS AFTN W/ THE HRRR NICELY DEPICTING THIS ACTIVITY ACROSS N
CENTRAL INTO E CENTRAL AREAS FROM ERLY THRU LATE AFTN. HAVE TRIED
TO REPRESENT THIS EXPECTED SCENARIO IN OUR POP AND WX GRIDS BUT
MAY NEED TO ADJUST AS THIS ACTIVITY DVLPS SINCE THESE STREAMERS
CAN BE QUITE LOCALIZED AND DIFFICULT TO PINPOINT IN ADVANCE...
REMAINDER OF THE FCST ON TRACK ATTM...
PREVIOUS DISCUSSION...
THE WEAK CLIPPER LOW WILL CROSS NORTHERN MAINE THIS MORNING AND
REDEVELOP IN THE CANADIAN MARITIMES THIS AFTERNOON. THE CLIPPER
WILL BRING LIGHT SNOW TO NORTHERN ZONES THIS MORNING...MOSTLY
NORTH OF HOULTON. ACCUMULATIONS COULD REACH AN INCH AND POSSIBLY
UP TO 2 INCHES IN HIGHER TERRAIN WITHIN NORTHERN AROOSTOOK COUNTY. AS
THE LOW MOVES EAST OF THE FORECAST AREA...IT WILL DRAG AN ARCTIC
FRONT THROUGH THE AREA. SOME SNOW SQUALLS ARE POSSIBLE. IT APPEARS
THE SQUALL WILL ORGANIZE FROM HOULTON WEST TO THE KATAHDIN REGION
TOWARDS MIDDAY AND THEN SWEEP SOUTH TOWARDS WASHINGTON COUNTY THIS
AFTERNOON AS IT DISSIPATES. SOUTHERN PORTIONS OF THE FORECAST AREA
SUCH AS BANGOR SHOULD ESCAPE THE SNOW OUTSIDE OF A BRIEF SNOW
SHOWER AS THE ARCTIC FRONT CROSSES. WITH SOME SUN...THE
BANGOR/BREWER AREA SHOULD REACH NEAR 20F TODAY. FURTHER
NORTH...ONLY SINGLE DIGITS ARE FORECAST FOR CARIBOU NORTHWARD INTO
THE SAINT JOHN VALLEY. THE ARCTIC FRONT WILL BRING ANOTHER ROUND
OF BITTER COLD AND WINDS FOR LATER THIS AFTERNOON AND TONIGHT.
WIND CHILLS MAY DROP TO LESS THAN MINUS 30 IN NORTHERN AROOSTOOK
AND HAVE ISSUED A WIND CHILL ADVISORY FOR AROOSTOOK...NORTHERN
PISCATAQUIS AND NORTHERN PENOBSCOT COUNTIES FOR TONIGHT. LOWS WILL
DROP TO MINUS 10 TO MINUS 20 IN THESE AREAS WITH WINDS GUSTING TO
OVER 20 MPH. THE WINDS WILL DECREASE LATER IN THE NIGHT AS HIGH
PRESSURE BUILDS. ELSEWHERE...LOWS OF ZERO TO TEN BELOW ARE
EXPECTED.&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
*MAIN ISSUES WILL BE LOW WIND CHILLS SAT MORNING AND A POTENTIAL
SNOWSTORM SUNDAY.
*WINTER STORM WATCHES HAVE BEEN ISSUED FOR THE SOUTHERN HALF OF THE
CWA FOR LATE SAT NIGHT AND SUNDAY.
A COLD HIGH CENTERED JUST WEST OF QUEBEC CITY AT 12Z SAT WILL
GRADUALLY LIFT TO THE NORTH OF THE AREA SAT NIGHT. AS THE CENTER OF
THE HIGH IS WEST OF THE AREA FIRST THING SAT MORNING THERE WILL BE
SOME WIND AND THE POTENTIAL FOR LOW WIND CHILLS SAT MORNING. THE
WIND SPEED LOOKS MARGINAL (AROUND 10 MPH). WIND CHILL ADVISORIES
WERE ISSUED FOR TONIGHT AND EXTENDED INTO SAT MORNING.
LOW PRESSURE ACROSS THE GULF COAST STATES SAT MORNING IS EXPECTED TO
LIFT UP TO NEAR NANTUCKET BY 12Z SUN AND CONTINUE TO DEEPEN AS
THE LOW RACES NE AND PASSES JUST EAST OF NOVA SCOTIA SUN
AFTERNOON AND EVENING. SNOW IS EXPECTED TO DEVELOP FROM THE
SOUTHWEST AFTER MIDNIGHT SAT NIGHT AND SNOW SHOULD BE FALLING
ACROSS MOST IF NOT ALL OF DOWNEAST MAINE BY 12Z SUN. THE SNOW
WILL OVERSPREAD THE REMAINDER OF THE CWA SUN MORNING. GIVEN THE
TRACK OF THE LOW THE HEAVIEST SNOW WILL FALL ACROSS DOWNEAST AREAS
WITH AMOUNTS DROPPING OFF TO THE NORTH OF THE KATAHDIN REGION. AS
THE MODELS HAVE NOW JOGGED BACK A BIT TO THE WEST IT NOW APPEARS
THAT THERE IS A GOOD CHANCE OF 8-14 INCHES OF SNOW ACROSS DOWNEAST
MAINE. THE STORM IS PROGRESSIVE WITH AN INCOMING UPPER TROUGH FROM
THE WEST IT IS UNLIKELY THAT AMOUNTS WILL EXCEED MUCH MORE THAN 14
INCHES. THE LATEST 00Z GFS IS EVEN FURTHER TO THE WEST TAKING THE
LOW RIGHT OVER NOVA SCOTIA AND WOULD BRING WARNING CRITERIA SNOW
ALL THE WAY NORTH AND ACROSS THE CROWN OF MAINE AND MIGHT EVEN
INTRODUCE A BIT OF A MIX ALONG THE IMMEDIATE COAST FOR A BRIEF
TIME SUN AFTERNOON. THE 00Z OPERATIONAL GFS IS FURTHER WEST THAN
ITS ENSEMBLE MEAN AND THERE ARE ONLY A COUPLE OF ENSEMBLE MEMBERS
THAT ARE AS FAR WEST AS THE OPERATIONAL GFS. THE LATEST 00Z ECMWF
IS VERY CONSISTENT WITH ITS PREVIOUS RUN AND IS ALSO VERY CLOSE TO
THE GFS ENSEMBLE MEAN AND CANADIAN GEM. FORECASTER CONFIDENCE IS
HIGH ENOUGH TO ISSUE A WINTER STORM WATCH FOR LATE SAT NIGHT INTO
SUNDAY FOR DOWNEAST AREAS INTO CENTRAL MAINE WITH THE IDEA THAT
LATER SHIFTS CAN REFINE THE AREA AS NEEDED. THE FORECAST AMOUNTS
ARE BASED VERY CLOSELY ON A BLEND OF THE GFS ENSEMBLE
MEAN/OPERATIONAL ECMWF/CANADIAN. THE HEADLINES WERE WELL
COLLABORATED WITH WFO GYX AND DISCUSSED WITH THE WPC.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
THE SFC LOW PULLS AWAY FROM THE REGION SUN NIGHT AND MON WITH AN
INVERTED TROUGH EXTENDING BACK ACROSS THE AREA. THE MID/UPPER LEVEL
LOW FOLLOWS SUN NIGHT INTO MON MORNING. THIS WILL LIKELY KEEP SOME
LIGHTER SNOW FALLING ACROSS PARTS OF NORTHERN AND EASTERN MAINE
INTO MON MORNING. HIGH PRESSURE THEN BUILDS ACROSS THE REGION MON
NIGHT. AN INTERESTING LOOKING CLIPPER MOVES ACROSS THE AREA
TUE WITH A GOOD CHANCE OF SNOW. THE MODELS ARE HINTING AT A
SECONDARY THAT MAY DEVELOP IN THE GULF OF MAINE AND PRODUCE MORE
SIGNIFICANT SNOWS ACROSS THE AREA TUE NIGHT INTO WED. THU LOOKS
MAINLY DRY AND SEASONABLY COLD AS THE LOW MOVES OUT OF THE AREA
AND IS AT LEAST BRIEFLY REPLACED BY A RIDGE OF HIGH PRESSURE
BUILDING IN FROM THE WEST.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: MOSTLY IFR THIS MORNING NORTH OF HUL IN SNOW. VFR IS
EXPECTED THROUGH THE PERIOD FOR BGR AND BHB. SNOW SQUALLS MAY SET
UP WITH AN ARCTIC COLD FRONT CROSSING THE REGION LATER THIS
MORNING AND EARLY AFTERNOON...MOST LIKELY AFFECTING HUL. SOME MVFR
CIGS ARE POSSIBLE AT TIMES FROM PQI NORTHWARD THIS AFTERNOON AND
TONIGHT.
SHORT TERM: VFR SAT INTO THE FIRST HALF OF SAT NIGHT. CONDITIONS
WILL DETERIORATE LATE SAT NIGHT WITH IFR AND EVEN SOME VLIFR IN SNOW
SUNDAY...ESPECIALLY AT THE SOUTHERN TERMINALS. MOSTLY IFR/MVFR IN
AREAS OF LIGHT SNOW THAT WILL LIKELY PERSIST INTO MONDAY. ANOTHER
SYSTEM MAY QUICKLY FOLLOW WITH MORE IFR/MVFR IN SNOW TUE.
&&
.MARINE...
NEAR TERM: HAVE UPGRADED THE SCA TO A GALE WARNING FOR TODAY WITH
THE STRONG PRESSURE GRADIENT AHEAD OF AN ARCTIC FRONT AND STRONG
NW WINDS BEHIND THE FRONT BRINGING BITTER COLD AIR OVER THE
RELATIVELY WARM WATERS. WILL GO WITH A SCA FOR THE INTRACOASTAL
THROUGH TONIGHT. WHEN THE GALE ENDS THIS EVENING...AN SCA WILL BE
NEEDED TO REPLACE IT.
SHORT TERM: A GALE IS POSSIBLE FOR A TIME SUNDAY AS LOW PRESSURE
DEEPENS AS IT PASSES EAST OF THE FORECAST WATERS. A GUSTY WIND ON
THE BACKSIDE OF LOW WILL LIKELY KEEP AT LEAST SCA CONDITIONS GOING
INTO MONDAY. THE WIND WILL DIMINISH AND THE SEAS SUBSIDE MON NIGHT
BELOW SCA LEVELS AS HIGH PRESSURE BRIEFLY BUILDS OVER THE WATERS.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...WIND CHILL ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
SATURDAY FOR MEZ001>006-010.
WINTER STORM WATCH FROM LATE SATURDAY NIGHT THROUGH SUNDAY
EVENING FOR MEZ011-015>017-029>032.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ052.
GALE WARNING UNTIL 7 PM EST THIS EVENING FOR ANZ050-051.
&&
$$
NEAR TERM...KHW/MCW
SHORT TERM...CB
LONG TERM...CB
AVIATION...KHW/MCW/CB
MARINE...KHW/MCW/CB
AREA FORECAST DISCUSSION...UPDATED
NWS ALBUQUERQUE NM
1133 AM MST FRI DEC 13 2013
.AVIATION...
18Z TAF CYCLE
THE UPPER LEVEL LOW WHICH HAS IMPACTED THE STATE OVERNIGHT WILL
PROGRESS EASTWARD. THIS WILL ALLOW CURRENT MVFR CIGS/VIS
RESTRICTIONS TO IMPROVE DRAMATICALLY THIS AFTERNOON. ANOTHER
SYSTEM WILL BE ON THE HEALS OF THE CURRENT ONE AND WILL SPREAD MID
AND HIGH LEVEL CLOUDS OVER NORTHERN AND EASTERN AREAS TONIGHT.
A TRICKY FORECAST LIES AHEAD FOR KFMN...KGUP...AND
KROW BECAUSE BRIEF CLEARING BETWEEN THE SYSTEMS COMBINED WITH LOW
LEVEL RESIDUAL MOISTURE COULD LEAD TO VERY LOW CIGS AND FG
DVLPMENT. HEDGED FORECAST WORDING AT GUP/FMN AND LEFT IT OUT OF
THE FMN FORECAST AT THIS TIME. THE INCREASED MID/HIGH LVL CLOUDS
COULD IMPEDE THIS LOW CIG DVLPMENT TONIGHT. WILL BE MONITORING
OBSERVATION AND MODEL TRENDS CLOSELY. WINDS THROUGH 0Z WILL ALSO
PICKUP TODAY ALONG THE CENTRAL MTNS WITH GUSTS REACHING AS HIGH AS
40 KT ACROSS THE EASTERN PLAINS. BTWN 25 TO 30 KT AT ROW/TCC.
CML/JBW
&&
.PREV DISCUSSION...1025 AM MST FRI DEC 13 2013...
QUICK UPDATE TO REMOVE POPS FOR THE REST OF THE DAY. SOME FLURRIES
AND/OR SPRINKLES MAY OCCUR...BUT GIVEN RADAR TRENDS AND THE FACT
THAT THE SYSTEM IS PULLING AWAY FROM THE AREA...ADDITIONAL
MEASURABLE PRECIPITATION IS NOT EXPECTED. FOG ALSO APPEARS TO BE
LIFTING ALONG THE PECOS RIVER VALLEY AND ACROSS PORTIONS OF THE
LOWER RIO GRANDE VALLEY...THOUGH MUCH SLOWER IN THIS LATTER AREA.
MEANWHILE...UP AT CLAYTON...DOWNSLOPING OFF THE RATON
RIDGE/JOHNSON MESA HAS ALLOWED TEMPS TO CLIMB ABOVE FORECAST HIGHS
ALREADY. THUS...HAVE RAISED CLAYTONS HIGH TEMP A FEW DEGREES.
HOWEVER...A BACK DOOR COLD FRONT SHOULD TAPER THE WARMING THERE
SHORTLY.
WILL ALSO ADD SOUTHWEST CHAVES COUNTY TO THE WIND ADVISORY THIS
AFTERNOON AS 35-40KT H7 FLOW WILL BE OVERHEAD AND THERE COULD BE
SOME MOUNTAIN WAVE ACTIVITY...ESPECIALLY IF CLOUDS JUST EAST OF
THE SANDIA/MANZANO MTNS ARE ANY INDICATION.
UPDATES OUT SHORTLY.
34
.PREV DISCUSSION...259 AM MST FRI DEC 13 2013...
WATER VAPOR LOOP THIS MORNING SHOWING UPPER LOW OPENING UP OVER AZ
AS IT TRAVELS QUICKLY EAST TOWARD NM. PRECIP ACTIVITY WITH FORCING
AHEAD OF THE WAVE IS SHOWERY IN NATURE AND MOVING QUICKLY EAST INTO
THE RIO GRANDE VALLEY. LIGHT SNOW ACCUMS WILL OCCUR IN BRIEF BOUTS
OF CONVECTIVE ACTIVITY. THE EXCEPTION WILL BE WEST FACING SLOPES OF
THE CENTRAL MT CHAIN WHERE ENHANCED UPSLOPE WILL SQUEEZE OUT MORE
STRATIFORM ACTIVITY FOR SEVERAL HOURS THIS MORNING...EQUATING TO
PERHAPS AN INCH OR TWO ABOVE 7500 FT. THE HRRR ENSEMBLE REFLECTIVITY
PRODUCT IS HANDLING THE CURRENT DISTRIBUTION OF PRECIP WELL SO LEFT
POPS THIS MORNING AROUND THE ABQ METRO AREA AND SURROUNDING HIGH
TERRAIN IN THE MODERATE TO HIGH CHANCE RANGE.
THE MAIN STORY TODAY WILL BE WINDS ALONG AND EAST OF THE CENTRAL MT
CHAIN WHERE FAST LAMINAR FLOW WITHIN THE EXITING UPPER TROUGH WILL
COMBINE WITH A DEEPENING SURFACE LOW OVER THE PLAINS. SPC WRF-ARW
INDICATES 850-700MB LAYER WINDS OF 30-35KTS STRETCHING DOWN THE U.S.
285 CORRIDOR FROM CLINES TO VAUGHN...ALONG 54 NEAR CORONA...AND MUCH
OF LINCOLN AND WESTERN CHAVES COUNTIES. WINDS WILL INCREASE THRU THE
MORNING AND PEAK NEAR 2 PM THEN TAPER OFF BY SUNSET.
A RATHER STOUT UPPER WAVE IN NW FLOW WILL SHIFT QUICKLY OVER THE
AREA BEHIND THIS DEPARTING WAVE AND DELIVER ANOTHER PUNCH OF COLDER
AIR FOR SATURDAY. HIGHS WILL BE ROUGHLY 5 TO 10F BLW NORMAL. TEMPS
WILL MODERATE BACK TO NEAR NORMAL SUNDAY AND CONTINUE WARMING THRU
MID WEEK AS UPPER FLOW BACKS MORE ZONAL. MODELS ARE STILL CLOSING IN
ON A WHOPPER OF A STORM FOR LATE IN THE WEEK WITH ANOTHER SURGE OF
BITTER COLD AIR...SNOW...AND STRONG WINDS.
GUYER
.FIRE WEATHER...
AS EXPECTED THE BAJA LOW APPROACHING FROM THE WEST SOUTHWEST IS
WEAKENING INTO AN OPEN TROUGH AND WILL PASS EASTWARD OVER THE FIRE
WEATHER FORECAST AREA TODAY. MAINLY SCATTERED SNOW SHOWERS ARE EXPECTED
THIS MORNING ALONG AND WEST OF THE CENTRAL MOUNTAIN CHAIN. THIS
AFTERNOON THE BASE OF THE TROUGH WILL BE EXITING...BUT ANOTHER UPPER
TROUGH WILL DROP SOUTHEASTWARD TOWARD NM QUICKLY ON THE HEELS OF THE
FIRST SYSTEM. THIS WILL KEEP ISOLATED RAIN AND SNOW SHOWERS IN THE
FORECAST MAINLY FROM THE CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAIN
CHAIN THROUGH THE AFTERNOON.
BETWEEN THE TWO UPPER TROUGHS A NORTHWESTERLY 700 MB WIND SPEED
MAXIMUM WILL DEVELOP ALONG THE CONTINENTAL DIVIDE AND CENTRAL
MOUNTAIN CHAIN...ESPECIALLY SOUTH OF THE NORTHERN MOUNTAINS...WITH
SPEEDS PEAKING AROUND 30-45 KTS DURING THE EARLY TO MID AFTERNOON.
AT THE SURFACE A 1007 MB SURFACE LOW IN SE CO WILL SINK
SOUTHEASTWARD ACROSS THE TX PANHANDLE TODAY...KEEPING THE SURFACE
PRESSURE GRADIENT TIGHT ALONG AND EAST OF THE CENTRAL MOUNTAINS. NW
WIND GUSTS IN THE 30 TO 40 MPH RANGE WILL BE COMMON IN THE W CENTRAL
AND SW MOUNTAINS TODAY...WITH GUSTS FROM 40 TO 50 MPH ALONG AND EAST
OF THE CENTRAL MOUNTAINS TO THE PECOS RIVER VALLEY. AS A RESULT OF
THE STRONGER WINDS...GOOD TO EXCELLENT VENTILATION ARE EXPECTED
MAINLY SOUTH OF I-40 TODAY WITH BROAD POCKETS OF POOR VENTILATION
ACROSS THE NORTH.
TROUGHING IN NW FLOW ALOFT AND COLD AIR ADVECTION AT THE SURFACE
WILL LINGER OVER NM THROUGH SATURDAY. COOLING THAT BEGINS ACROSS
NORTHERN AND WESTERN AREAS TODAY WILL SPREAD TO INCLUDE SOUTHEAST
AREAS ON SATURDAY. HIGH TEMPERATURES SATURDAY WILL BE A FEW TO 10
DEGREES BELOW TODAYS READINGS. VENT RATES SHOULD PLUMMET IN MOST
LOCATIONS SATURDAY...EXCEPT ACROSS THE FAR EASTERN PLAINS WHERE GOOD
OR BETTER VENTILATION IS EXPECTED DUE TO PERSISTENT NORTH WINDS.
UNDER NW FLOW ALOFT DRY WEATHER IS EXPECTED SATURDAY THROUGH THE
MIDDLE OF THE COMING WORK WEEK WITH HUMIDITIES TRENDING DOWNWARD
EACH DAY THROUGH TUESDAY BEFORE THEY STABILIZE. TEMPERATURES WILL
TREND UPWARD THROUGH TUESDAY AS WELL WITH HIGHS REACHING ABOVE
NORMAL AREAWIDE BEGINNING MONDAY. AFTER GENERALLY POOR VENTILATION
SUNDAY THROUGH WEDNESDAY...VENT RATES SHOULD BEGIN TO IMPROVE ON
THURSDAY AS AN UPPER TROUGH DIGS INTO THE WESTERN US AND SW FLOW
ALOFT BEGINS TO STRENGTHEN OVER NM. SW WINDS SHOULD ALSO BEGIN TO
STRENGTHEN THURSDAY ACROSS WESTERN AND EAST CENTRAL PARTS OF THE
FORECAST AREA.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ521>524-526-533-537>540.
&&
$$
AREA FORECAST DISCUSSION
NWS ALBUQUERQUE NM
1025 AM MST FRI DEC 13 2013
.UPDATE...
QUICK UPDATE TO REMOVE POPS FOR THE REST OF THE DAY. SOME FLURRIES
AND/OR SPRINKLES MAY OCCUR...BUT GIVEN RADAR TRENDS AND THE FACT
THAT THE SYSTEM IS PULLING AWAY FROM THE AREA...ADDITIONAL
MEASURABLE PRECIPITATION IS NOT EXPECTED. FOG ALSO APPEARS TO BE
LIFTING ALONG THE PECOS RIVER VALLEY AND ACROSS PORTIONS OF THE
LOWER RIO GRANDE VALLEY...THOUGH MUCH SLOWER IN THIS LATTER AREA.
MEANWHILE...UP AT CLAYTON...DOWNSLOPING OFF THE RATON
RIDGE/JOHNSON MESA HAS ALLOWED TEMPS TO CLIMB ABOVE FORECAST HIGHS
ALREADY. THUS...HAVE RAISED CLAYTONS HIGH TEMP A FEW DEGREES.
HOWEVER...A BACK DOOR COLD FRONT SHOULD TAPER THE WARMING THERE
SHORTLY.
WILL ALSO ADD SOUTHWEST CHAVES COUNTY TO THE WIND ADVISORY THIS
AFTERNOON AS 35-40KT H7 FLOW WILL BE OVERHEAD AND THERE COULD BE
SOME MOUNTAIN WAVE ACTIVITY...ESPECIALLY IF CLOUDS JUST EAST OF
THE SANDIA/MANZANO MTNS ARE ANY INDICATION.
UPDATES OUT SHORTLY.
34
&&
.PREV DISCUSSION...453 AM MST FRI DEC 13 2013...
.AVIATION...
12Z TAF CYCLE
AN UPPER TROUGH AND SURFACE COLD FRONT CROSSING FROM THE W WILL
CONTINUE TO PRODUCE MVFR AND PATCHY IFR CONDITIONS IN SNOW SHOWERS
OVER CENTRAL AND WESTERN PARTS OF THE FORECAST AREA THROUGH THE
MORNING. MOUNTAIN OBSCURATIONS ARE ALSO EXPECTED. FURTHER...PATCHY
FOG AND LOW CLOUDS WILL CONTINUE TO AFFLICT THE PECOS RIVER
VALLEY UNTIL MID MORNING. WINDS WILL SHIFT OUT OF THE NW AND
BECOME GUSTY AS THE A COLD FRONT CROSSES. THE STRONGEST WINDS
WILL BE FOUND EAST OF THE CENTRAL AND SOUTH CENTRAL MOUNTAINS
WHERE GUSTS MAY REACH 45 KT FROM LATE MORNING TO MID AFTN. A
SECONDARY UPPER TROUGH COULD TRIGGER A FEW LIGHT SNOW SHOWERS AND
MOUNTAIN OBSCURATIONS IN THE NORTHERN MOUNTAINS TONIGHT...ESPECIALLY
NEAR THE CO BORDER.
44
.PREV DISCUSSION...259 AM MST FRI DEC 13 2013...
WATER VAPOR LOOP THIS MORNING SHOWING UPPER LOW OPENING UP OVER AZ
AS IT TRAVELS QUICKLY EAST TOWARD NM. PRECIP ACTIVITY WITH FORCING
AHEAD OF THE WAVE IS SHOWERY IN NATURE AND MOVING QUICKLY EAST INTO
THE RIO GRANDE VALLEY. LIGHT SNOW ACCUMS WILL OCCUR IN BRIEF BOUTS
OF CONVECTIVE ACTIVITY. THE EXCEPTION WILL BE WEST FACING SLOPES OF
THE CENTRAL MT CHAIN WHERE ENHANCED UPSLOPE WILL SQUEEZE OUT MORE
STRATIFORM ACTIVITY FOR SEVERAL HOURS THIS MORNING...EQUATING TO
PERHAPS AN INCH OR TWO ABOVE 7500 FT. THE HRRR ENSEMBLE REFLECTIVITY
PRODUCT IS HANDLING THE CURRENT DISTRIBUTION OF PRECIP WELL SO LEFT
POPS THIS MORNING AROUND THE ABQ METRO AREA AND SURROUNDING HIGH
TERRAIN IN THE MODERATE TO HIGH CHANCE RANGE.
THE MAIN STORY TODAY WILL BE WINDS ALONG AND EAST OF THE CENTRAL MT
CHAIN WHERE FAST LAMINAR FLOW WITHIN THE EXITING UPPER TROUGH WILL
COMBINE WITH A DEEPENING SURFACE LOW OVER THE PLAINS. SPC WRF-ARW
INDICATES 850-700MB LAYER WINDS OF 30-35KTS STRETCHING DOWN THE U.S.
285 CORRIDOR FROM CLINES TO VAUGHN...ALONG 54 NEAR CORONA...AND MUCH
OF LINCOLN AND WESTERN CHAVES COUNTIES. WINDS WILL INCREASE THRU THE
MORNING AND PEAK NEAR 2 PM THEN TAPER OFF BY SUNSET.
A RATHER STOUT UPPER WAVE IN NW FLOW WILL SHIFT QUICKLY OVER THE
AREA BEHIND THIS DEPARTING WAVE AND DELIVER ANOTHER PUNCH OF COLDER
AIR FOR SATURDAY. HIGHS WILL BE ROUGHLY 5 TO 10F BLW NORMAL. TEMPS
WILL MODERATE BACK TO NEAR NORMAL SUNDAY AND CONTINUE WARMING THRU
MID WEEK AS UPPER FLOW BACKS MORE ZONAL. MODELS ARE STILL CLOSING IN
ON A WHOPPER OF A STORM FOR LATE IN THE WEEK WITH ANOTHER SURGE OF
BITTER COLD AIR...SNOW...AND STRONG WINDS.
GUYER
.FIRE WEATHER...
AS EXPECTED THE BAJA LOW APPROACHING FROM THE WEST SOUTHWEST IS
WEAKENING INTO AN OPEN TROUGH AND WILL PASS EASTWARD OVER THE FIRE
WEATHER FORECAST AREA TODAY. MAINLY SCATTERED SNOW SHOWERS ARE EXPECTED
THIS MORNING ALONG AND WEST OF THE CENTRAL MOUNTAIN CHAIN. THIS
AFTERNOON THE BASE OF THE TROUGH WILL BE EXITING...BUT ANOTHER UPPER
TROUGH WILL DROP SOUTHEASTWARD TOWARD NM QUICKLY ON THE HEELS OF THE
FIRST SYSTEM. THIS WILL KEEP ISOLATED RAIN AND SNOW SHOWERS IN THE
FORECAST MAINLY FROM THE CONTINENTAL DIVIDE TO THE CENTRAL MOUNTAIN
CHAIN THROUGH THE AFTERNOON.
BETWEEN THE TWO UPPER TROUGHS A NORTHWESTERLY 700 MB WIND SPEED
MAXIMUM WILL DEVELOP ALONG THE CONTINENTAL DIVIDE AND CENTRAL
MOUNTAIN CHAIN...ESPECIALLY SOUTH OF THE NORTHERN MOUNTAINS...WITH
SPEEDS PEAKING AROUND 30-45 KTS DURING THE EARLY TO MID AFTERNOON.
AT THE SURFACE A 1007 MB SURFACE LOW IN SE CO WILL SINK
SOUTHEASTWARD ACROSS THE TX PANHANDLE TODAY...KEEPING THE SURFACE
PRESSURE GRADIENT TIGHT ALONG AND EAST OF THE CENTRAL MOUNTAINS. NW
WIND GUSTS IN THE 30 TO 40 MPH RANGE WILL BE COMMON IN THE W CENTRAL
AND SW MOUNTAINS TODAY...WITH GUSTS FROM 40 TO 50 MPH ALONG AND EAST
OF THE CENTRAL MOUNTAINS TO THE PECOS RIVER VALLEY. AS A RESULT OF
THE STRONGER WINDS...GOOD TO EXCELLENT VENTILATION ARE EXPECTED
MAINLY SOUTH OF I-40 TODAY WITH BROAD POCKETS OF POOR VENTILATION
ACROSS THE NORTH.
TROUGHING IN NW FLOW ALOFT AND COLD AIR ADVECTION AT THE SURFACE
WILL LINGER OVER NM THROUGH SATURDAY. COOLING THAT BEGINS ACROSS
NORTHERN AND WESTERN AREAS TODAY WILL SPREAD TO INCLUDE SOUTHEAST
AREAS ON SATURDAY. HIGH TEMPERATURES SATURDAY WILL BE A FEW TO 10
DEGREES BELOW TODAYS READINGS. VENT RATES SHOULD PLUMMET IN MOST
LOCATIONS SATURDAY...EXCEPT ACROSS THE FAR EASTERN PLAINS WHERE GOOD
OR BETTER VENTILATION IS EXPECTED DUE TO PERSISTENT NORTH WINDS.
UNDER NW FLOW ALOFT DRY WEATHER IS EXPECTED SATURDAY THROUGH THE
MIDDLE OF THE COMING WORK WEEK WITH HUMIDITIES TRENDING DOWNWARD
EACH DAY THROUGH TUESDAY BEFORE THEY STABILIZE. TEMPERATURES WILL
TREND UPWARD THROUGH TUESDAY AS WELL WITH HIGHS REACHING ABOVE
NORMAL AREAWIDE BEGINNING MONDAY. AFTER GENERALLY POOR VENTILATION
SUNDAY THROUGH WEDNESDAY...VENT RATES SHOULD BEGIN TO IMPROVE ON
THURSDAY AS AN UPPER TROUGH DIGS INTO THE WESTERN US AND SW FLOW
ALOFT BEGINS TO STRENGTHEN OVER NM. SW WINDS SHOULD ALSO BEGIN TO
STRENGTHEN THURSDAY ACROSS WESTERN AND EAST CENTRAL PARTS OF THE
FORECAST AREA.
44
&&
.ABQ WATCHES/WARNINGS/ADVISORIES...
WIND ADVISORY UNTIL 4 PM MST THIS AFTERNOON FOR THE FOLLOWING
ZONES...NMZ521>524-526-533-537>540.
&&
$$
34
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
137 PM EST FRI DEC 13 2013
.SYNOPSIS...
LAKE EFFECT SNOW WILL TAPER OFF LATER TODAY AS A STORM APPROACHES
THE AREA FROM THE SOUTH. THIS SYSTEM WILL SPREAD SNOW ACROSS THE
AREA ON SATURDAY...WITH THE CHANCE FOR SOME ICE OVER PARTS OF
NORTHEAST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12 PM UPDATE...LES BAND HAS NOW BEEN STRIPPED OFF THE LONG AXIS OF
LAKE ONTARIO AS WINDS ARE NOW NORTHERLY. ALLOWED WARNING FOR NRN
ONEIDA COUNTY TO EXPIRE WILL CONTINUE WITH ADV UNTIL MID AFTERNOON
FOR AREAS SE OF LAKE.
1000 AM UPDATE...LES BAND EAST OF LAKE ONTARIO NOW MAKING GOOD
PROGRESS SOUTH AS SFC TROF DROPS THROUGH THE LAKE REGION. LOCAL
ARW HANDLING THE CURRENT ORIENTATION WELL AND EXPECT THE BULK OF
ACTIVITY TO BE SOUTH OF NRN ONEIDA COUNTY AROUND MIDDAY. CURRENT
WARNING TIMING HERE LOOKS GOOD. ACTIVITY IS NOW DROPPING SOUTH
INTO THE ADVISORY AREA. BAND WILL WEAKEN AS IT DROPS SOUTH DUE TO
SHORTER FETCH AND GRADUALLY LOWERING INVERSION. LAKE EFFECT SNOW
SHOWERS WILL CONTINUE IN THE ADV AREA UNTIL MID AFTERNOON THEN
WEAKEN. JUST MINOR ADJUSTMENTS TO CURRENT FORECAST.
PREVIOUS DISC...
TRICKY LES FCST AS THE SHRT TERM MODELS ARE IN POOR AGREEMENT.
WRFARW SHOWS THE BAND DROPPING SWRD INTO THE DAYLIGHT HERS BEFORE
DISSIPATING MIDDAY. NAM SHOWS THE BAND PRETTY MUCH WEAKENING IN
PLACE WITH ONLY A SLGT SWRD DRIFT. CRNTS SHOW THE SFC FLOW OVER
WRN NY BCMG SWLY MAKING ME WONDER IF THE BAND WILL EVER MAKE IT
INTO THE WARNING/ADVISORY AREA. AT THE VERY LEAST...INCRSD LL
SHEAR WILL WEKEN THE SYSTEM. IN ANY CASE...WILL LEAVE THE FLAGS IN
PLACE FOR NOW BUT MAY BE LOOKING A MODIFYING THE FLAGS EARLY ON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/...
ONLY A BRIEF BRK IN THE ACTION AHD OF THE NEXT SYSTEM. OVERRUNING
PCPN DVLPS LATE FRI NGT AND EARLY SAT UNDER THE RR OF THE UPR JET.
OVERALL THE UPWARD VERTICAL MOTION IS MODERATE AT BEST AND
MOISTURE IS NOT EXACTLY DEEP AS THE INITIAL SOURCE REGION IS THE
UPR PLAINS. THIS SHD RESULT IN LGT SNOWS FOR THE INITIAL HRS OF THE
STORM.
LTR SAT...DEEPER MOSITURE FROM THE GULF ARRIVES AS THE SRN BRANCH
SYSTEM DVLPS A SFC LOW MVG NWRD IN THE TN VLY. SYSTEM HAS DBL SFC
LOWS EARLY ON WITH A LOW OVER OH WHILE A CSTL LOW DEEPENS OVER ERN
NC. LOWS CONSOLIDATE ARND 06Z SUN OVER CSTL NJ AND BEGIN TO DEEPEN
MORE RAPIDLY. GOOD DEEP ELY FLOW DVLPS LATE IN THE GAME AND A PD
OF HEAVIER SNOW SEEMS LIKELY LATE SAT NGT BEFORE THE SNOW TAPERS
OFF SUN MRNG. EVEN SO...BEST UVM IS NOT EXACTLY WELL ALIGNED WITH
THE BEST DENDRITIC GROWTH AREA FOR MUCH OF THE STORM. ALSO...
SYSTEM REMAINS AS AN OPEN WV AT THE UPR LVLS SO IS LACKING A GOOD
CHANCE FOR DEFORMATION BANDS DVLPG LATE IN THE EVENT.
EVEN THE NORMALLY ROBUST NAM QPF FCSTS ARE AT HIGH END ADVISORY
LVLS FOR THE STORM LDG ME TO THINK THAT SNOWFALL AMTS WILL BE BLO
WARNING CRITERIA. BEST CHANCE FOR HIER AMTS APPEAR TO BE OVER THE
WRN CATS AND PERHAPS XTTRM NEPA. FURTHER SOUTH...THERE/S STILL THE
RISK OF SOME ICE PELLETS OVER THE POCONOS AND SCRANTON METRO AREA.
FRZG RAIN SEEMS LIKE A MORE REMOTE CHANCE WITH THE NARROW ABV FRZG
LYR AND VERY COLD SFC AIR.
KIND OF HEMMED IN BY WATCHES SO WENT WITH A WATCH FOR THE AREA AS
WELL...BUT MOST LIKELY LOOKING AT A HIGH END ADVISORY.
&&
.LONG TERM /TUESDAY THROUGH THURSDAY/...
115 PM UPDATE...
WITH A SNOW EVENT TOMORROW I WENT WITH WPC GUIDANCE FOR THE LONG
TERM PERIOD WITH A FEW MINOR TWEAKS. OVERALL A FAIRLY QUIET
PATTERN WITH NO HUGE STORMS. WE WILL SEE A SERIES OF WEAK
WAVES...ONE COMING MONDAY NIGHT INTO TUESDAY AND AGAIN TUESDAY
NIGHT INTO WEDNESDAY...WHICH WILL KEEP SNOW SHOWERS AROUND. IN
ADDITION SOME PERIODS OF LAKE EFFECT ARE POSSIBLE. TOWARD
THURSDAY HEIGHTS WILL RISE AND DRIER WEATHER IS EXPECTED. ALTHOUGH
BEYOND OUR CURRENT EXTENDED...BOTH THE GFS AND EURO POINT TO OUR
NEXT SYSTEM BEING AN INLAND RUNNER WITH MUCH WARMER AIR AND RAIN
BY THE END OF NEXT WEEK.
&&
.AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
115 PM UPDATE...
TWO PERIODS OF CONCERN FOR THE TAFS. THE FIRST WILL BE THROUGH
EARLY EVENING WITH ONGOING LAKE SNOWS...THEN A BREAK...WITH A MORE
WIDESPREAD SNOW DEVELOPING DURING THE DAY SATURDAY.
FOR NOW IFR VSBYS WILL REMAIN POSSIBLE AT KSYR/KITH AND KBGM
THROUGH 21Z IN LAKE EFFECT SNOW. OUTSIDE OF THESE AREAS VFR TO
MVFR CIGS ARE LIKELY THROUGH EARLY EVENING WITH A FEW FLURRIES OR
A BRIEF SNOW SHOWER. AFTER EARLY TONIGHT MOST TERMINALS WILL GO TO
VFR WITH LAKE INFLUENCES NOT BEING AN ISSUE ANYMORE.
TOWARD DAYBREAK SATURDAY SNOW WILL SPREAD FROM SOUTHWEST TO
NORTHEAST ACROSS THE TERMINALS. ONCE THE SNOW ARRIVES IFR VSBYS
WILL BE LIKELY THROUGH THE REST OF THE DAY WITH LOW END MVFR CIGS
TO PERHAPS SOME IFR ESPECIALLY ON THE ELEVATED SITES. ARRIVAL TIME
LOOKS TO BE BETWEEN 12Z AND 15Z SOUTHERN TERMINALS AFTER 17Z UP
NORTH.
OUTLOOK...
SAT NIGHT/SUN...RESTRICTIONS LIKELY REGION-WIDE IN SNOW AS STORM SYSTEM
MOVES THROUGH THE AREA...WITH EACH TERMINAL EXPERIENCING IFR OR
WORSE AT TIMES. SOME IMPROVEMENT TOWARD SUNDAY AFTERNOON.
SUN NGT/MON/TUE/WED...RESTRICTIONS POSSIBLE FROM LAKE EFFECT SNOW SHOWERS
ESPECIALLY KSYR-KRME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ009-015>018-022>025-036-037-044>046-
055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/RRM
SHORT TERM...DGM/PVN
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1215 PM EST FRI DEC 13 2013
.SYNOPSIS...
LAKE EFFECT SNOW WILL TAPER OFF LATER TODAY AS A STORM APPROACHES
THE AREA FROM THE SOUTH. THIS SYSTEM WILL SPREAD SNOW ACROSS THE
AREA ON SATURDAY...WITH THE CHANCE FOR SOME ICE OVER PARTS OF
NORTHEAST PENNSYLVANIA.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
12 PM UPDATE...LES BAND HAS NOW BEEN STRIPPED OFF THE LONG AXIS OF
LAKE ONTARIO AS WINDS ARE NOW NORTHERLY. ALLOWED WARNING FOR NRN
ONEIDA COUNTY TO EXPIRE WILL CONTINUE WITH ADV UNTIL MID AFTERNOON
FOR AREAS SE OF LAKE.
1000 AM UPDATE...LES BAND EAST OF LAKE ONTARIO NOW MAKING GOOD
PROGRESS SOUTH AS SFC TROF DROPS THROUGH THE LAKE REGION. LOCAL
ARW HANDLING THE CURRENT ORIENTATION WELL AND EXPECT THE BULK OF
ACTIVITY TO BE SOUTH OF NRN ONEIDA COUNTY AROUND MIDDAY. CURRENT
WARNING TIMING HERE LOOKS GOOD. ACTIVITY IS NOW DROPPING SOUTH
INTO THE ADVISORY AREA. BAND WILL WEAKEN AS IT DROPS SOUTH DUE TO
SHORTER FETCH AND GRADUALLY LOWERING INVERSION. LAKE EFFECT SNOW
SHOWERS WILL CONTINUE IN THE ADV AREA UNTIL MID AFTERNOON THEN
WEAKEN. JUST MINOR ADJUSTMENTS TO CURRENT FORECAST.
PREVIOUS DISC...
TRICKY LES FCST AS THE SHRT TERM MODELS ARE IN POOR AGREEMENT.
WRFARW SHOWS THE BAND DROPPING SWRD INTO THE DAYLIGHT HERS BEFORE
DISAPPATING MIDDAY. NAM SHOWS THE BAND PRETTY MUCHH WEAKENING IN
PLACE WITH ONLY A SLGT SWRD DRIFT. CRNTS SHOW THE SFC FLOW OVER
WRN NY BCMG SWLY MAKING ME WONDER IF THE BAND WILL EVER MAKE IT
INTO THE WARNING/ADVISORY AREA. AT THE VERY LEAST...INCRSD LL
SHEAR WILL WEKEN THE SYSTEM. IN ANY CASE...WILL LEAVE THE FLAGS IN
PLACE FOR NOW BUT MAY BE LOOKING A MODIFYING THE FLAGS EARLY ON.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
ONLY A BRIEF BRK IN THE ACTION AHD OF THE NEXT SYSTEM. OVERRUNING
PCPN DVLPS LATE FRI NGT AND EARLY SAT UNDER THE RR OF THE UPR JET.
OVERALL THE UPWARD VERTICAL MOTION IS MODERATE AT BEST AND
MOISTURE IS NOT EXACTLY DEEP AS THE INITIAL SOURCE REGION IS THE
UPR PLAINS. THIS SHD RESULT IN LGT SNOWS FOR THE INITIAL HRS OF THE
STORM.
LTR SAT...DEEPER MOSITURE FROM THE GULF ARRIVES AS THE SRN BRANCH
SYSTEM DVLPS A SFC LOW MVG NWRD IN THE TN VLY. SYSTEM HAS DBL SFC
LOWS EARLY ON WITH A LOW OVER OH WHILE A CSTL LOW DEEPENS OVER ERN
NC. LOWS CONSOLIDATE ARND 06Z SUN OVER CSTL NJ AND BEGIN TO DEEPEN
MORE RAPIDLY. GOOD DEEP ELY FLOW DVLPS LATE IN THE GAME AND A PD
OF HEAVIER SNOW SEEMS LIKELY LATE SAT NGT BEFORE THE SNOW TAPERS
OFF SUN MRNG. EVEN SO...BEST UVM IS NOT EXACTLY WELL ALIGNED WITH
THE BEST DENDRITIC GROATH AREA FOR MUCH OF THE STORM. ALSO...
SYSTEM REMAINS AS AN OPEN WV AT THE UPR LVLS SO IS LACKING A GOOD
CHANCE FOR DEFORMATION BANDS DVLPG LATE IN THE EVENT.
EVEN THE NORMALLY ROBUST NAM QPF FCSTS ARE AT HIGH END ADVISORY
LVLS FOR THE STORM LDG ME TO THINK THAT SNOWFALL AMTS WILL BE BLO
WARNING CRITERIA. BEST CHANCE FOR HIER AMTS APPEAR TO BE OVER THE
WRN CATS AND PERHAPS XTTRM NEPA. FURTHER SOUTH...THERE/S STILL THE
RISK OF SOME ICE PELLETS OVER THE POCONOS AND SCRANTON METRO AREA.
FRZG RAIN SEEMS LIKE A MORE REMOTE CHANCE WITH THE NARROW ABV FRZG
LYR AND VERY COLD SFC AIR.
KIND OF HEMMED IN BY WATCHES SO WENT WITH A WATCH FOR THE AREA AS
WELL...BUT MOST LIKELY LOOKING AT A HIGH END ADVISORY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
THE LONG TERM PERIOD BEGINS WITH A PERSISTENT, COLD TROF PARKED
OVER THER NORTHEASTERN UNITED STATES. THIS PATTERN WILL SLOWLY
WEAKEN AND ERODE THROUGH MID WEEK, AS THE FLOW RELAXES TO A MORE
ZONAL PATTERN. BY THURSDAY A JET WILL BEGIN TO DIVE INTO THE
WESTERN U.S. ALLOWING HEIGHTS TO RISE IN THE EAST. THIS WILL LEAD
TO A TEMPORARY MODERATION IN TEMPERATURE.
&&
.AVIATION /17Z FRIDAY THROUGH TUESDAY/...
WRFARW MODEL WAS TOO AGGRESSIVE OVERNIGHT IN BRINGING THE LAKE
ONTARIO BAND SOUTHWARD, AND PUSHING THE LAKE ERIE BAND INTO THE
CENTRAL SOUTHERN TIER AND FINGER LAKES. LATEST HRRR LOOKS MORE IN
TUNE WITH REALITY, AND I WILL LEAN IN ITS DIRECTION WITH THE NEW
TAF PACKAGE. IN GENERAL...WILL BE CUTTING BACK ON THE RESTRICTIONS
OVER ELM/ITH/BGM AND DELAYING THE ONSET AT RME UNTIL 12Z-15Z.
OUTLOOK...
SAT/SUN...RESTRICTIONS LIKELY REGION-WIDE IN SNOW AS STORM SYSTEM
MOVES THROUGH THE AREA...WITH EACH TERMINAL EXPERIENCING IFR OR
WORSE AT TIMES.
SUN NGT/MON/TUE...RESTRICTIONS POSSIBLE FROM LAKE EFFECT SNOW SHOWERS
ESPECIALLY KSYR-KRME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR PAZ038>040-043-044-047-048-072.
NY...WINTER STORM WATCH FROM SATURDAY MORNING THROUGH SUNDAY
MORNING FOR NYZ009-015>018-022>025-036-037-044>046-
055>057-062.
LAKE EFFECT SNOW ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ018-036-037.
&&
$$
SYNOPSIS...DGM
NEAR TERM...DGM/RRM
SHORT TERM...DGM/PVN
LONG TERM...DJP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
205 PM CST FRI DEC 13 2013
.SHORT TERM...(TONIGHT THROUGH SATURDAY NIGHT)
ISSUED AT 205 PM CST FRI DEC 13 2013
WATER VAPOR LOOP/LATEST RUC 500MB ANALYSIS SHOWS A BROAD LONG WAVE
TROUGH ENCOMPASSING THE ENTIRE CONUS. WITHIN THIS LONG WAVE TROUGH
THERE ARE TWO MID-LEVEL SHORTWAVE TROUGHS THAT WILL EVENTUALLY
IMPACT THE AREA TONIGHT THROUGH SATURDAY EVENING. TROUGH NUMBER ONE
WAS MOVING EAST OUT OF MT/WY TOWARD THE NORTHERN PLAINS WHILE A MORE
POTENT TROUGH NUMBER TWO WAS MOVING EAST OUT OF CO/NM INTO THE
SOUTHERN PLAINS. AT THE SURFACE...THIS TRANSLATED TO AN AREA OF
CYCLOGENESIS OVER WESTERN KS WITH A WARM FRONT EXTENDING ALONG THE
IA/MO BORDER INTO CENTRAL IL. CURRENTLY...OUR LOCAL FORECAST AREA
WAS IN BETWEEN THE INFLUENCES OF THE SOUTHERN PLAINS LOW AND HIGH
PRESSURE OVER SOUTHERN MANITOBA CANADA WITH EAST WINDS AND MOSTLY
CLOUDY CONDITIONS RESULTING. TEMPERATURES THIS AFTERNOON RANGED FROM
THE TEENS ACROSS NORTH CENTRAL WI...TO THE LOWER AND MIDDLE 20S
ELSEWHERE.
WILL BE WATCHING THE SOUTHERN PLAINS AND NORTHERN PLAINS TROUGHS
CONVERGE ON THE AREA LATE TONIGHT INTO SATURDAY. NOT PARTICULARLY
STRONG DYNAMICS ASSOCIATED WITH THESE WAVES. HOWEVER...THE AREA WILL
BE IN LONG-LIVED RIGHT ENTRANCE REGION OF 300MB JET WHILE THERE IS
SOME WEAK ISENTROPIC UPGLIDE NOTED ON THE NAM 275K SURFACE.
ALSO...THERE IS A DECENT PASSING LOBE OF 700-300 PV-ADVECTION FROM
ABOUT 12Z-18Z SATURDAY. ALL THIS IS EXPECTED TO COME TOGETHER TO
PRODUCE A FAIRLY WIDESPREAD AREA OF LIGHT SNOW WITH THE PEAK
CENTERED FROM ABOUT 09Z-15Z...THEN TAPERING OFF IN THE
AFTERNOON/SATURDAY EVENING AS THE TROUGH AXIS PASSES AND SUBSIDENCE
TAKES OVER. SOME VERY LIGHT SNOW/FLURRIES WILL BE POSSIBLE THROUGH
MIDNIGHT SATURDAY NIGHT BEFORE FULL SUBSIDENCE KICKS IN...DRYING
THINGS OUT. APPEARS AT THIS TIME THERE IS THE POTENTIAL FOR 1/2 UP
TO 2 INCHES OF SNOWFALL OUT OF THIS FROM TONIGHT THROUGH SATURDAY
EVENING. TEMPERATURE-WISE... LOOK FOR LOWS TONIGHT IN THE SINGLE
DIGITS AND TEENS...HIGHS ON SATURDAY IN THE UPPER TEENS TO MIDDLE
20S...AND LOWS SATURDAY NIGHT DROPPING INTO THE SINGLE DIGITS ABOVE
AND BELOW ZERO.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 205 PM CST FRI DEC 13 2013
SUNDAY LOOKS DRY AT THIS TIME BUT CLOUDS WILL BE THICKENING ONCE
AGAIN IN ADVANCE OF THE NEXT MID-LEVEL SHORTWAVE TO IMPACT THE AREA.
FOR SUNDAY NIGHT INTO MONDAY...WARM AIR ADVECTION WING OF THIS WAVE
MOVES IN WITH A GOOD CHANCE FOR LIGHT SNOW TO OVERSPREAD THE AREA.
WILL HAVE TO WATCH CLOSELY AS MODEL BUFKIT SOUNDINGS HINT AT THE
POTENTIAL FOR SOME LOSS OF ICE IN THE COLUMN. THIS COULD LEAD TO
SOME FREEZING DRIZZLE ISSUES. KEPT PRECIPITATION AS ALL SNOW FOR NOW
AFTER COORDINATION/COLLABORATION WITH OTHER OFFICES...BUT WILL
REMAIN LEARY AND KEEP A CLOSE EYE ON LATER MODEL RUNS FOR FREEZING
DRIZZLE POTENTIAL. OTHERWISE...SNOWFALL LOOKS TO BE VERY LIGHT WITH
LESS THAN AN INCH EXPECTED.
TUESDAY THROUGH WEDNESDAY LOOK TO BE DRY FOR NOW AS NORTHWEST FLOW
ALOFT PERSISTS ACROSS THE EASTERN HALF OF THE CONUS.
ECMWF/GFS COMING INTO BETTER AGREEMENT WITH THE LOW PRESSURE SYSTEM
AFFECTING THE AREA ON THURSDAY. APPEARS THERE WILL BE ENOUGH WARM
AIR DRAWN IN WITH THIS SYSTEM TO PRODUCE A RAIN/SNOW MIX FOR
PORTIONS OF THE AREA AS TEMPERATURES WARM INTO THE LOWER/MIDDLE 30S
ALONG AND SOUTH OF I-90. LOOK FOR THE PRECIPITATION TO SWITCH BACK
TO ALL SNOW AS COLD AIR SWEEPS IN BEHIND THE DEPARTING LOW THURSDAY
NIGHT.
THERE WILL BE A LINGERING CHANCE FOR LIGHT SNOW ON FRIDAY AS A
POTENT/COLD MID-LEVEL TROUGH MOVES TOWARD THE UPPER MISSISSIPPI
RIVER FROM THE NORTHERN PLAINS. OTHERWISE...MUCH COLDER TEMPERATURES
LOOK TO INVADE THE AREA WITH HIGHS DROPPING BACK INTO THE TEENS/20S.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SATURDAY AFTERNOON)
ISSUED AT 1222 PM CST FRI DEC 13 2013
LOWER CONFIDENCE TAF FORECAST THIS PERIOD. BIG PICTURE BELIEF IS
THAT THERE WILL BE SOME SNOW AT THE TAF SITES FOR A PERIOD OF TIME
FROM 06-18Z...BUT THE QUESTION REMAINS OF HOW LOW THE CIGS/VSBYS
WILL GET WITH THIS SYSTEM MOVING THROUGH.
CURRENTLY AN MVFR CLOUD DECK RESIDES JUST NORTH OF THE TAF SITES AND
THIS IS SLOWLY MOVING SOUTHWEST TOWARD THE AIRFIELDS AND WILL ARRIVE
AS THE AFTERNOON PROGRESSES. THIS IS A STABLE CLOUD FIELD AND LOWER
CONDITIONS THAN MVFR ARE NOT EXPECTED. AT 18Z...THE LEADING EDGE TO
THE CLOUDS WERE ALONG A KCMY-KONA-KSYN LINE.
TWO SYSTEMS WILL AFFECT THE AREA OVERNIGHT AND SATURDAY...ONE COMING
FROM THE NW AND ANOTHER MOVING BY TO THE SOUTH. THE NW SYSTEM SHOULD
BRING SOME LIGHT SNOW INTO THE TAFS BY LATE TONIGHT HOWEVER THE LOW-
LEVEL LIFT IS SOMEWHAT WEAK...WHILE THE MID-UPPER LEVELS ARE A BIT
MORE FAVORABLE. WHILE THE MVFR CLOUD DECK WILL BE IN PLACE...JUST
HOW MUCH SATURATION AND LIFT WILL OCCUR DETERMINES THE VSBY
REDUCTION IN THE TAFS. HAVE PROVIDED A MORE CONSERVATIVE TAF WITH
IFR VSBYS FOR NOW. HOWEVER...CUSTOMERS SHOULD MONITOR LATER
FORECASTS IF FLYING SATURDAY MORNING. IMPROVING TRENDS ARE EXPECTED
FOR SATURDAY AFTERNOON AS THE SYSTEMS SHIFT EAST OF THE AREA.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...DAS
LONG TERM....DAS
AVIATION.....BAUMGARDT