Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 12/09/13
AREA FORECAST DISCUSSION
NWS TAUNTON MA
1022 PM EST SUN DEC 8 2013
.SYNOPSIS...
LOW PRESSURE LIFTING NORTH FROM THE MID ATLANTIC WILL BRING MIXED
PRECIP LATE TONIGHT INTO MONDAY. MAINLY DRY...BUT UNSEASONABLY
COLD AND BLUSTERY WEATHER IS EXPECTED FOR THE REST OF THE UPCOMING
WORK WEEK. WE WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR A
PERIOD OF LIGHT SNOW ON TUESDAY...MAINLY SOUTH OF THE MASSACHUSETTS
TURNPIKE.
&&
.NEAR TERM /UNTIL 2 AM MONDAY MORNING/...
10 PM UPDATE...
LOW LEVEL DRY AIR IS HOLDING BACK THE PRECIP SO WE DELAYED THE
ONSET OF THE HIGHER POPS...WITH SNOW BEGINNING SOUTH OF THE MASS
PIKE BETWEEN MIDNIGHT AND 2 AM...THEN SPREADING NORTH THROUGH 4
AM. REST OF FORECAST APPEARS ON TRACK.
LATEST NAM STILL INDICATING POTENTIAL FOR MESOSCALE BANDING MOVING
UP ALONG THE S COAST AND CAPE/ISLANDS 06-09Z AS STRONG 850 MB
FRONTOGENESIS DEVELOPS WITHIN TIGHTENING THERMAL GRADIENT AND
DECENT LIFT IN THE SNOW GROWTH REGION. HRRR ALSO SHOWING THIS
POTENTIAL. HOWEVER...THIS IS THE TIME THE WARM NOSE ABOVE 800 MB
MOVES IN SO PRECIP WILL LIKELY BE CHANGING TO SLEET DURING THIS
TIME. IF IT REMAINED SNOW...POTENTIAL EXISTS FOR A QUICK INCH OR
2 THROUGH NEAR S COAST AND CAPE COD...BUT THE MORE LIKELY OUTCOME
IS A COATING TO AN INCH BEFORE A CHANGE TO SLEET.
&&
.SHORT TERM /2 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
AN OPEN-WAVE TROUGH ACROSS THE GREAT LAKES REGION HAS BEGUN TO
INTERACT WITH THE BROADER SUB-TROPICAL FLOW ACROSS THE EASTERN
CONUS. INFLECTION ALONG THE COLLOCATED TIGHT THERMAL GRADIENT HAS
SUBSEQUENTLY RESULTED IN A WEAK AREA OF LOW PRESSURE PRESENTLY OFF
THE MID-ATLANTIC WHICH WILL DRIFT NORTHEASTWARD ACROSS CAPE COD
BRINGING WITH IT A WINTRY MIX OF SNOW...SLEET...AND FREEZING RAIN
FOR SOUTHERN NEW ENGLAND DURING THE TIMEFRAME /ESPECIALLY THE MONDAY
MORNING COMMUTE/.
HAVE GREATER CONFIDENCE WITH COLDER SOLUTIONS. WITH BROAD AGREEMENT
AND RUN-TO-RUN CONTINUITY FROM THE ECMWF...PREFER THE MESO-NAM AND
WRF-MODEL SOLUTIONS WHICH CAPTURE THE COLD-AIR DAMMING PROCESSES
THROUGH THE CONNECTICUT RIVER VALLEY /SEE 1000-850 THICKNESSES/.
TRENDS ARE NOTEWORTHY WITHIN THE LATEST HRRR RUNS. BUT OVERALL THERE
IS STILL PLENTY OF UNCERTAINTY CONCERNING THERMAL PROFILES AND THE
ACCOMPANYING TRANSITION PROCESS OF WINTRY WEATHER TO PLAIN RAIN.
THAT BEING SAID...THERE IS A LOT TO CONSIDER. WITH H975 AGEOSTROPHIC
FLOW OUT OF THE INTERIOR NORTH WITH A WEAK LOW TRACKING ACROSS THE
CAPE...NOT EXPECTING EASTERLY ONSHORE FLOW NORTH OF THE LOW TO SCOUR
OUT INTERIOR SURFACE COLD AIR EFFECTIVELY. EXPECT PREVAILING
NORTHERLY COLD-AIR DRAINAGE FLOW...JAMMING UP THROUGHOUT INTERIOR
VALLEYS /ESPECIALLY THE CT RIVER VALLEY/. 2M FORECASTED TEMPERATURES
TAKEN MAINLY FROM MESO-NAM/WRF-MODEL SOLUTIONS. THOUGH THE EASTERLY
ONSHORE FLOW WILL RESULT IN A FASTER TRANSITION OF PRECIPITATION
TYPES ACROSS EAST COASTAL PLAIN IN THE MORNING...EXPECTING A WINTRY
MIX TO LAST LONGER ACROSS THE INTERIOR INTO THE MIDDAY AND POSSIBLY
THE AFTERNOON HOURS. UPSTREAM TRENDS ACROSS INTERIOR MID-ATLANTIC
SHOW THIS PROCESS ALREADY ONGOING WHICH ADD FURTHER CONFIDENCE THAT
COLD-AIR DAMMING OVER THE INTERIOR WILL BE A BIG ISSUE AS TO WINTER
WEATHER OUTCOMES.
PRECIPITATION AND SNOW/ICE AMOUNTS REMAIN A CHALLENGE...AND LIKELY
THERE ARE ALWAYS SURPRISES IN STORE WITH SYSTEMS SUCH AS THESE.
CONSIDERING THE AFOREMENTIONED SPATIAL AND TEMPORAL CHALLENGES IN THE
PRECIPITATION TRANSITION...IMPACTING ACCUMULATIONS AT THE SURFACE...
ANOTHER POINT OF CONCERN IS UPON PRECIPITATION AMOUNTS. EVALUATING
THE ATMOSPHERE...FORCING IS MAINLY WITHIN LOW-LEVELS WITH LITTLE
INDICATION OF DEEP-LAYER ASCENT ALBEIT SOME BROAD-SCALE DIFFLUENCE
ALOFT. YET SREF V-WIND ANOMALIES AT H85 ARE +2 STANDARD-DEVIATIONS
AND NOTING UPSTREAM TRENDS OVER THE MID-ATLANTIC...THERE IS THE
DISTINCT POSSIBILITY FOR A MESO-SCALE BAND OF SNOW ACROSS SOUTHERN
NEW ENGLAND COLLOCATED WITH THE TIGHT H85 THERMAL GRADIENT WHERE
STRONG LOW-LEVEL CONVERGENCE IS MODELED TO LIFT THROUGH BETTER SNOW-
GROWTH REGIONS. THERE IS SOME SIGNAL WITHIN NEAR-TERM MESOSCALE
SOLUTIONS...ALBEIT CHAOTIC. IT IS ENTIRELY PLAUSIBLE TO SEE AREAS IN
PROXIMITY TO THE SOUTH-COAST OF SEEING A COUPLE OF INCHES OF SNOW IN
A SHORT PERIOD OF TIME DURING THE EARLY ONSET BEFORE TRANSITIONING
TO RAIN.
AS SUCH...WILL TAKE 1-2 INCH ACCUMULATIONS DOWN TO THE SOUTH-COAST.
WILL HAVE 2-4 INCHES FOR PORTIONS OF NORTH AND WEST MA AND SOUTHERN
NH. ICE ACCUMULATIONS UP TO A TENTH OF AN INCH EXPECTED ALONG AND
EAST OF THE EASTERN COASTAL PLAIN...EAST OF THE I-95/I-495 BELTWAY.
TOTAL LIQUID PRECIPITATION AMOUNTS AROUND 0.4 INCHES WITH THE
HEAVIEST AMOUNTS JUST OFF THE SOUTH-COAST.
EXPECT ACCUMULATIONS TO BEGIN THIS EVENING AND CONTINUE THROUGH THE
MORNING COMMUTE. WILL SEE A GRADUAL TRANSITION OF FROZEN P-TYPES
BACK INTO THE INTERIOR BEGINNING AROUND 6-8 AM...WITH LOCATIONS
ACROSS WESTERN AND NORTHERN MA AND SOUTHERN NH SEEING THE LONGEST
PERIOD OF A WINTRY MIX....EAST-COAST TRANSITIONING QUICKEST. HAVE
LENGTHENED THE WINTER- WEATHER ADVISORY FOR HARTFORD COUNTY CT
WITH THE EXPECTATION OF COLD-AIR DRAINAGE PROCESSES. IMPACTS IN
THE WINTER WEATHER ADVISORY...BUT IN BREVITY...EXPECT A MESSY
MONDAY MORNING COMMUTE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* PERIOD OF LIGHT SNOW POSSIBLE SOUTH OF MA PIKE ON TUE
* MAINLY DRY AND UNSEASONABLY COLD WED THROUGH FRI
* LOW CONFIDENCE FORECAST NEXT WEEKEND
DETAILS...
MONDAY NIGHT...
OTHER THAN PERHAPS A LEFT OVER SPOT SHOWER IN THE EARLY EVENING...
DRY WEATHER EXPECTED. A COLD FRONT SWINGS THROUGH THE REGION EARLY
IN THE EVENING. TEMPS WILL ACTUALLY RISE ABOVE FREEZING ACROSS
PORTIONS OF THE INTERIOR THAT HAVE BEEN JAMMED IN SHALLOW COLD AIR
DURING THE DAY MONDAY. THE REASON FOR THIS IS THAT WARMER MID
LEVEL AIR WILL BE TEMPORARILY MIXED DOWN...AS WINDS SHIFT TO THE
WEST. THIS SHOULD ALLOW ANY LEFTOVER ICY CONDITIONS ON ROADWAYS TO
MELT. COLDER AIR WILL FINALLY BEGIN WORKING BACK INTO THE REGION
OVERNIGHT...WITH LOWS BY DAYBREAK BACK INTO THE 20S ACROSS THE
INTERIOR. THE COASTAL PLAIN SHOULD ONLY SEE LOWS REACH THE LOWER
TO MIDDLE 30S.
TUESDAY...
THE MAIN CONCERN IS THE CHANCES FOR A PERIOD OF LIGHT SNOW ON
TUESDAY...MAINLY SOUTH OF THE MA TURNPIKE. A WEAK WAVE OF LOW
PRESSURE WILL BE PASSING WELL TO OUR SOUTH...BUT AN APPROACHING
SHORTWAVE BACKS THE UPPER LEVEL FLOW. IT PLACES US UNDERNEATH A
POTENT JET STREAK WHICH RESULTS IN A PERIOD OF DECENT MID LEVEL
LIFT. WILL BE FIGHTING LOW LEVEL DRY AIR SO NOT EXPECTING A LOT OF
PRECIP...BUT A PERIOD OF LIGHT SNOW IS STILL POSSIBLE SOUTH OF MA
TURNPIKE ESPECIALLY NEAR THE SOUTH COAST. PERHAPS ITS MILD ENOUGH
FOR MIXED PRECIP AT THE ONSET ACROSS CAPE/ISLANDS...BUT SHOULD
TURN OVER TO ALL LIGHT SNOW. A COATING TO PERHAPS 1 INCH OF SNOW IS
POSSIBLE IN A FEW LOCATIONS. THERE ALSO IS A LOW PROBABILITY OF A BIT
MORE SNOW THAN THAT NEAR THE SOUTH COAST...BUT MOST GUIDANCE DOES NOT
SUPPORT THAT AT THIS TIME.
WEDNESDAY THROUGH FRIDAY...
NORTHWEST FLOW ALOFT WILL RESULT IN UNSEASONABLY COLD WEATHER FOR
SOUTHERN NEW ENGLAND. THERE ARE SOME MODEL DISCREPANCIES ON THE
TIMING OF REINFORCING SHOTS OF COLD AIR...HENCE UNCERTAINTIES ON
WHICH DAY WILL BE THE COLDEST. MAINLY DRY WEATHER DOMINATES OVER
THIS TIME PERIOD...BUT CAN/T RULE OUT A BRIEF PASSING FLURRY/SNOW
SHOWER WITH SOME MOISTURE STARVED NORTHERN STREAM ENERGY/FRONTAL
PASSAGES. IT ALSO WILL BE WINDY AT TIMES...SO IT CERTAINLY WILL
FEEL WINTERLIKE.
SATURDAY AND SUNDAY...
FORECAST CONFIDENCE IS VERY LOW OVER THIS TIME. THE ONE THING WILL
HAVE TO WATCH NEXT WEEKEND IS THE TRACK A WAVE OF LOW PRESSURE TO
OUR SOUTH. MOST MODELS SUGGEST THAT THE SYSTEM WILL PASS FAR
ENOUGH SOUTH TO SPARE OUR REGION OF SIGNIFICANT PRECIP.
HOWEVER...SOME MODELS SUGGEST THE LARGE HIGH TO OUR NORTH MAY
EVENTUALLY RESULT IN ONSHORE FLOW...BRINGING THE POTENTIAL FOR
SOME LIGHT WINTRY PRECIPITATION. OTHER GUIDANCE SUGGESTS SOUTHWEST
FLOW ALOFT MAY RESULT IN SOME OVER RUNNING PRECIPITATION. ALL IN
ALL...VERY LOW CONFIDENT FORECAST FOR NEXT WEEKEND.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /THROUGH MONDAY/...
MVFR-IFR CONDITIONS OVERSPREAD THE REGION AFT 04Z. PRECIPITATION
SHOULD WORK IN FROM SOUTH TO NORTH ACROSS THE REST OF THE REGION
BETWEEN 4Z AND 8Z. PTYPE STARTS AS SNOW THEN CHANGES TO SLEET AND
FINALLY RAIN MON MORNING IN THE COASTAL PLAIN. INTERIOR TERMINALS
WILL LIKELY HAVE TO DEAL WITH AN EXTENDED PERIOD OF FREEZING RAIN
INTO THE AFTERNOON.
CONDITIONS BEGIN TO IMPROVE INTO MONDAY NIGHT.
KBOS TAF...MODERATE CONFIDENCE IN TAFS. LOW CONFIDENCE IN
ONSET OF PRECIP AND TIMING OF PTYPE TRANSITIONS.
KBDL TAF...MODERATE CONFIDENCE IN TAFS. LOW CONFIDENCE IN ONSET OF
PRECIP AND TIMING OF PTYPE TRANSITIONS.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. LEFT OVER MVFR-IFR
CONDITIONS EARLY IN THE EVENING IMPROVE TO VFR BEHIND A COLD FRONT.
TUESDAY...LOW CONFIDENCE. A PERIOD OF MVFR-IFR CONDITIONS POSSIBLE
SOUTH OF THE MA TURNPIKE IN A ROUND OF LIGHT SNOW. OTHERWISE...VFR
CONDITIONS FOR THE REST OF THE TIME.
WEDNESDAY THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE. VFR
CONDITIONS DOMINATE WITH GUSTY WNW WINDS AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /THROUGH MONDAY/...HIGH CONFIDENCE.
NORTHERLY WINDS OVER THE WATERS WILL VEER EAST-SOUTHEASTERLY WITH
TIME GUSTING 25 TO 30 KTS DURING THE DAY MONDAY AS AN AREA OF LOW
PRESSURE CROSSES INTO SOUTHERN NEW ENGLAND. WITH THE LOW/S PASSAGE
EXPECT WINDS TO BACK MORE SOUTHERLY.
PROLONGED PERIOD OF FETCH WILL RESULT IN SEAS OF 6 TO 8 FEET
ACROSS THE OUTER WATERS IMPACTING THE EAST- FACING ATLANTIC
BEACHES. SMALL CRAFT ADVISORIES IN EFFECT FOR ALL LOCATIONS EXCEPT
INNER BAYS.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...HIGH CONFIDENCE.
THE GENERAL IDEA IS THAT THE PASSAGE OF A COUPLE OF STRONG COLD
FRONTS WILL RESULT IN PERSISTENT WEST TO NORTHWEST WINDS OVER THIS
TIME. GIVEN THE STRONG COLD ADVECTION OVER THE WATERS...SCA WIND
GUSTS ARE EXPECTED OVER MUCH OF THIS TIME PERIOD OVER THE OPEN
WATERS. WE MAY EVEN SEE A BRIEF GALE FOR A TIME ON WEDNESDAY. THERE
ALSO WILL BE LULLS IN THE WIND...BUT TIMING THAT THIS FAR OUT IS
IMPOSSIBLE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 10 PM EST MONDAY FOR CTZ002.
WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR CTZ003-004.
MA...WINTER WEATHER ADVISORY UNTIL 10 PM EST MONDAY FOR MAZ002>004-
008>011-026.
WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR MAZ005-
012>014-017.
NH...WINTER WEATHER ADVISORY UNTIL 10 PM EST MONDAY FOR NHZ011-012-
015.
RI...WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR RIZ001>004-
006.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 10 PM EST MONDAY FOR
ANZ231>234.
SMALL CRAFT ADVISORY FROM 3 AM MONDAY TO 7 AM EST TUESDAY FOR
ANZ235-237-254>256.
SMALL CRAFT ADVISORY FROM 7 AM MONDAY TO 7 AM EST TUESDAY FOR
ANZ250-251.
&&
$$
SYNOPSIS...FRANK/SIPPRELL
NEAR TERM...KJC/FRANK
SHORT TERM...SIPPRELL
LONG TERM...FRANK
AVIATION...FRANK/SIPPRELL
MARINE...FRANK/SIPPRELL
AREA FORECAST DISCUSSION
NWS TAUNTON MA
739 PM EST SUN DEC 8 2013
.SYNOPSIS...
LOW PRESSURE LIFTING NORTH FROM THE MID ATLANTIC WILL BRING MIXED
PRECIP LATE TONIGHT INTO MONDAY. MAINLY DRY...BUT UNSEASONABLY
COLD AND BLUSTERY WEATHER IS EXPECTED FOR THE REST OF THE UPCOMING
WORK WEEK. WE WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR A
PERIOD OF LIGHT SNOW ON TUESDAY...MAINLY SOUTH OF THE MASSACHUSETTS
TURNPIKE.
&&
.NEAR TERM /UNTIL 4 AM MONDAY MORNING/...
730 PM UPDATE...
PREVIOUS FORECAST IS PRETTY MUCH ON TRACK. WE DID ADD A COATING TO
1 INCH OF SNOW POSSIBLE FOR EVEN THE OUTER-CAPE AND NANTUCKET.
ITS PRETTY COLD RIGHT NOW AND DEWPOINTS ARE IN THE UPPER TEENS TO
LOWER 20S...SO THINK THERE WILL BE SOME SNOW AT THE ONSET IN THIS
REGION AS WELL.
SNOW SHOULD OVERSPREAD THE REGION FROM SOUTH TO NORTH TONIGHT.
EXPECT SNOW TO WORK INTO AREAS SOUTH OF THE MA TURNPIKE BETWEEN 9 PM
AND 1 AM...THEN NORTH OF THAT REGION BETWEEN MIDNIGHT AND 4 AM.
GENERALLY EXPECT AN INCH OR TWO OF SNOW ACROSS MOST OF THE
REGION...BEFORE A CHANGE TO MIXED PRECIP. THE ONE THING WILL HAVE
TO WATCH IS IF THERE IS ANY BANDING. THE LIFT DOES NOT LOOK AS
ORGANIZED/INTENSE AS WHAT BROUGHT THE HEAVY SNOW TO THE MID ATLANTIC
STATES THIS AFTERNOON. HOWEVER...SOME OF THE MESOSCALE MODELS HINT
THERE COULD BE A BRIEF WINDOW FOR PERHAPS A BIT OF BANDING NEAR THE
SOUTH COAST AFTER MIDNIGHT. WE UPDATED OUR SNOWFALL PROBABILITIES
TO INDICATE A LOW PROBABILITY FOR THESE LOCATIONS REACHING OR
EXCEEDING 2 INCHES OF SNOW.
ALSO...A SPECIAL WEATHER STATEMENT WAS ISSUED FOR WHERE THERE IS NOT
A WINTER WEATHER ADVISORY IN EFFECT. STILL EXPECT SLIPPERY TRAVEL
OVERNIGHT INTO THE MON AM RUSH IN THIS REGION.
&&
.SHORT TERM /4 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
AN OPEN-WAVE TROUGH ACROSS THE GREAT LAKES REGION HAS BEGUN TO
INTERACT WITH THE BROADER SUB-TROPICAL FLOW ACROSS THE EASTERN
CONUS. INFLECTION ALONG THE COLLOCATED TIGHT THERMAL GRADIENT HAS
SUBSEQUENTLY RESULTED IN A WEAK AREA OF LOW PRESSURE PRESENTLY OFF
THE MID-ATLANTIC WHICH WILL DRIFT NORTHEASTWARD ACROSS CAPE COD
BRINGING WITH IT A WINTRY MIX OF SNOW...SLEET...AND FREEZING RAIN
FOR SOUTHERN NEW ENGLAND DURING THE TIMEFRAME /ESPECIALLY THE MONDAY
MORNING COMMUTE/.
HAVE GREATER CONFIDENCE WITH COLDER SOLUTIONS. WITH BROAD AGREEMENT
AND RUN-TO-RUN CONTINUITY FROM THE ECMWF...PREFER THE MESO-NAM AND
WRF-MODEL SOLUTIONS WHICH CAPTURE THE COLD-AIR DAMMING PROCESSES
THROUGH THE CONNECTICUT RIVER VALLEY /SEE 1000-850 THICKNESSES/.
TRENDS ARE NOTEWORTHY WITHIN THE LATEST HRRR RUNS. BUT OVERALL THERE
IS STILL PLENTY OF UNCERTAINTY CONCERNING THERMAL PROFILES AND THE
ACCOMPANYING TRANSITION PROCESS OF WINTRY WEATHER TO PLAIN RAIN.
THAT BEING SAID...THERE IS A LOT TO CONSIDER. WITH H975 AGEOSTROPHIC
FLOW OUT OF THE INTERIOR NORTH WITH A WEAK LOW TRACKING ACROSS THE
CAPE...NOT EXPECTING EASTERLY ONSHORE FLOW NORTH OF THE LOW TO SCOUR
OUT INTERIOR SURFACE COLD AIR EFFECTIVELY. EXPECT PREVAILING
NORTHERLY COLD-AIR DRAINAGE FLOW...JAMMING UP THROUGHOUT INTERIOR
VALLEYS /ESPECIALLY THE CT RIVER VALLEY/. 2M FORECASTED TEMPERATURES
TAKEN MAINLY FROM MESO-NAM/WRF-MODEL SOLUTIONS. THOUGH THE EASTERLY
ONSHORE FLOW WILL RESULT IN A FASTER TRANSITION OF PRECIPITATION
TYPES ACROSS EAST COASTAL PLAIN IN THE MORNING...EXPECTING A WINTRY
MIX TO LAST LONGER ACROSS THE INTERIOR INTO THE MIDDAY AND POSSIBLY
THE AFTERNOON HOURS. UPSTREAM TRENDS ACROSS INTERIOR MID-ATLANTIC
SHOW THIS PROCESS ALREADY ONGOING WHICH ADD FURTHER CONFIDENCE THAT
COLD-AIR DAMMING OVER THE INTERIOR WILL BE A BIG ISSUE AS TO WINTER
WEATHER OUTCOMES.
PRECIPITATION AND SNOW/ICE AMOUNTS REMAIN A CHALLENGE...AND LIKELY
THERE ARE ALWAYS SURPRISES IN STORE WITH SYSTEMS SUCH AS THESE.
CONSIDERING THE AFOREMENTIONED SPATIAL AND TEMPORAL CHALLENGES IN THE
PRECIPITATION TRANSITION...IMPACTING ACCUMULATIONS AT THE SURFACE...
ANOTHER POINT OF CONCERN IS UPON PRECIPITATION AMOUNTS. EVALUATING
THE ATMOSPHERE...FORCING IS MAINLY WITHIN LOW-LEVELS WITH LITTLE
INDICATION OF DEEP-LAYER ASCENT ALBEIT SOME BROAD-SCALE DIFFLUENCE
ALOFT. YET SREF V-WIND ANOMALIES AT H85 ARE +2 STANDARD-DEVIATIONS
AND NOTING UPSTREAM TRENDS OVER THE MID-ATLANTIC...THERE IS THE
DISTINCT POSSIBILITY FOR A MESO-SCALE BAND OF SNOW ACROSS SOUTHERN
NEW ENGLAND COLLOCATED WITH THE TIGHT H85 THERMAL GRADIENT WHERE
STRONG LOW-LEVEL CONVERGENCE IS MODELED TO LIFT THROUGH BETTER SNOW-
GROWTH REGIONS. THERE IS SOME SIGNAL WITHIN NEAR-TERM MESOSCALE
SOLUTIONS...ALBEIT CHAOTIC. IT IS ENTIRELY PLAUSIBLE TO SEE AREAS IN
PROXIMITY TO THE SOUTH-COAST OF SEEING A COUPLE OF INCHES OF SNOW IN
A SHORT PERIOD OF TIME DURING THE EARLY ONSET BEFORE TRANSITIONING
TO RAIN.
AS SUCH...WILL TAKE 1-2 INCH ACCUMULATIONS DOWN TO THE SOUTH-COAST.
WILL HAVE 2-4 INCHES FOR PORTIONS OF NORTH AND WEST MA AND SOUTHERN
NH. ICE ACCUMULATIONS UP TO A TENTH OF AN INCH EXPECTED ALONG AND
EAST OF THE EASTERN COASTAL PLAIN...EAST OF THE I-95/I-495 BELTWAY.
TOTAL LIQUID PRECIPITATION AMOUNTS AROUND 0.4 INCHES WITH THE
HEAVIEST AMOUNTS JUST OFF THE SOUTH-COAST.
EXPECT ACCUMULATIONS TO BEGIN THIS EVENING AND CONTINUE THROUGH THE
MORNING COMMUTE. WILL SEE A GRADUAL TRANSITION OF FROZEN P-TYPES
BACK INTO THE INTERIOR BEGINNING AROUND 6-8 AM...WITH LOCATIONS
ACROSS WESTERN AND NORTHERN MA AND SOUTHERN NH SEEING THE LONGEST
PERIOD OF A WINTRY MIX....EAST-COAST TRANSITIONING QUICKEST. HAVE
LENGTHENED THE WINTER- WEATHER ADVISORY FOR HARTFORD COUNTY CT
WITH THE EXPECTATION OF COLD-AIR DRAINAGE PROCESSES. IMPACTS IN
THE WINTER WEATHER ADVISORY...BUT IN BREVITY...EXPECT A MESSY
MONDAY MORNING COMMUTE.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* PERIOD OF LIGHT SNOW POSSIBLE SOUTH OF MA PIKE ON TUE
* MAINLY DRY AND UNSEASONABLY COLD WED THROUGH FRI
* LOW CONFIDENCE FORECAST NEXT WEEKEND
DETAILS...
MONDAY NIGHT...
OTHER THAN PERHAPS A LEFT OVER SPOT SHOWER IN THE EARLY EVENING...
DRY WEATHER EXPECTED. A COLD FRONT SWINGS THROUGH THE REGION EARLY
IN THE EVENING. TEMPS WILL ACTUALLY RISE ABOVE FREEZING ACROSS
PORTIONS OF THE INTERIOR THAT HAVE BEEN JAMMED IN SHALLOW COLD AIR
DURING THE DAY MONDAY. THE REASON FOR THIS IS THAT WARMER MID
LEVEL AIR WILL BE TEMPORARILY MIXED DOWN...AS WINDS SHIFT TO THE
WEST. THIS SHOULD ALLOW ANY LEFTOVER ICY CONDITIONS ON ROADWAYS TO
MELT. COLDER AIR WILL FINALLY BEGIN WORKING BACK INTO THE REGION
OVERNIGHT...WITH LOWS BY DAYBREAK BACK INTO THE 20S ACROSS THE
INTERIOR. THE COASTAL PLAIN SHOULD ONLY SEE LOWS REACH THE LOWER
TO MIDDLE 30S.
TUESDAY...
THE MAIN CONCERN IS THE CHANCES FOR A PERIOD OF LIGHT SNOW ON
TUESDAY...MAINLY SOUTH OF THE MA TURNPIKE. A WEAK WAVE OF LOW
PRESSURE WILL BE PASSING WELL TO OUR SOUTH...BUT AN APPROACHING
SHORTWAVE BACKS THE UPPER LEVEL FLOW. IT PLACES US UNDERNEATH A
POTENT JET STREAK WHICH RESULTS IN A PERIOD OF DECENT MID LEVEL
LIFT. WILL BE FIGHTING LOW LEVEL DRY AIR SO NOT EXPECTING A LOT OF
PRECIP...BUT A PERIOD OF LIGHT SNOW IS STILL POSSIBLE SOUTH OF MA
TURNPIKE ESPECIALLY NEAR THE SOUTH COAST. PERHAPS ITS MILD ENOUGH
FOR MIXED PRECIP AT THE ONSET ACROSS CAPE/ISLANDS...BUT SHOULD
TURN OVER TO ALL LIGHT SNOW. A COATING TO PERHAPS 1 INCH OF SNOW IS
POSSIBLE IN A FEW LOCATIONS. THERE ALSO IS A LOW PROBABILITY OF A BIT
MORE SNOW THAN THAT NEAR THE SOUTH COAST...BUT MOST GUIDANCE DOES NOT
SUPPORT THAT AT THIS TIME.
WEDNESDAY THROUGH FRIDAY...
NORTHWEST FLOW ALOFT WILL RESULT IN UNSEASONABLY COLD WEATHER FOR
SOUTHERN NEW ENGLAND. THERE ARE SOME MODEL DISCREPANCIES ON THE
TIMING OF REINFORCING SHOTS OF COLD AIR...HENCE UNCERTAINTIES ON
WHICH DAY WILL BE THE COLDEST. MAINLY DRY WEATHER DOMINATES OVER
THIS TIME PERIOD...BUT CAN/T RULE OUT A BRIEF PASSING FLURRY/SNOW
SHOWER WITH SOME MOISTURE STARVED NORTHERN STREAM ENERGY/FRONTAL
PASSAGES. IT ALSO WILL BE WINDY AT TIMES...SO IT CERTAINLY WILL
FEEL WINTERLIKE.
SATURDAY AND SUNDAY...
FORECAST CONFIDENCE IS VERY LOW OVER THIS TIME. THE ONE THING WILL
HAVE TO WATCH NEXT WEEKEND IS THE TRACK A WAVE OF LOW PRESSURE TO
OUR SOUTH. MOST MODELS SUGGEST THAT THE SYSTEM WILL PASS FAR
ENOUGH SOUTH TO SPARE OUR REGION OF SIGNIFICANT PRECIP.
HOWEVER...SOME MODELS SUGGEST THE LARGE HIGH TO OUR NORTH MAY
EVENTUALLY RESULT IN ONSHORE FLOW...BRINGING THE POTENTIAL FOR
SOME LIGHT WINTRY PRECIPITATION. OTHER GUIDANCE SUGGESTS SOUTHWEST
FLOW ALOFT MAY RESULT IN SOME OVER RUNNING PRECIPITATION. ALL IN
ALL...VERY LOW CONFIDENT FORECAST FOR NEXT WEEKEND.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
21Z UPDATE...
NEAR-TERM /THROUGH MONDAY/...
MVFR-IFR CONDITIONS OVERSPREAD THE REGION AFTER 2 OR 3Z ALONG SOUTH
COAST. PRECIPITATION SHOULD WORK IN FROM SOUTH TO NORTH ACROSS THE
REST OF THE REGION BETWEEN 4Z AND 8Z. PTYPE STARTS AS SNOW THEN
CHANGES TO SLEET AND FINALLY RAIN MON MORNING IN THE COASTAL PLAIN.
INTERIOR TERMINALS WILL LIKELY HAVE TO DEAL WITH AN EXTENDED PERIOD
OF FREEZING RAIN INTO THE AFTERNOON.
CONDITIONS BEGIN TO IMPROVE INTO MONDAY NIGHT.
KBOS TAF...MODERATE CONFIDENCE IN TAFS. LOW CONFIDENCE IN
ONSET OF PRECIP AND TIMING OF PTYPE TRANSITIONS.
KBDL TAF...MODERATE CONFIDENCE IN TAFS. LOW CONFIDENCE IN ONSET OF
PRECIP AND TIMING OF PTYPE TRANSITIONS.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. LEFT OVER MVFR-IFR
CONDITIONS EARLY IN THE EVENING IMPROVE TO VFR BEHIND A COLD FRONT.
TUESDAY...LOW CONFIDENCE. A PERIOD OF MVFR-IFR CONDITIONS POSSIBLE
SOUTH OF THE MA TURNPIKE IN A ROUND OF LIGHT SNOW. OTHERWISE...VFR
CONDITIONS FOR THE REST OF THE TIME.
WEDNESDAY THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE. VFR
CONDITIONS DOMINATE WITH GUSTY WNW WINDS AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /THROUGH MONDAY/...HIGH CONFIDENCE.
NORTHERLY WINDS OVER THE WATERS WILL VEER EAST-SOUTHEASTERLY WITH
TIME GUSTING 25 TO 30 KTS DURING THE DAY MONDAY AS AN AREA OF LOW
PRESSURE CROSSES INTO SOUTHERN NEW ENGLAND. WITH THE LOW/S PASSAGE
EXPECT WINDS TO BACK MORE SOUTHERLY.
PROLONGED PERIOD OF FETCH WILL RESULT IN SEAS OF 6 TO 8 FEET
ACROSS THE OUTER WATERS IMPACTING THE EAST- FACING ATLANTIC
BEACHES. SMALL CRAFT ADVISORIES IN EFFECT FOR ALL LOCATIONS EXCEPT
INNER BAYS.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...HIGH CONFIDENCE.
THE GENERAL IDEA IS THAT THE PASSAGE OF A COUPLE OF STRONG COLD
FRONTS WILL RESULT IN PERSISTENT WEST TO NORTHWEST WINDS OVER THIS
TIME. GIVEN THE STRONG COLD ADVECTION OVER THE WATERS...SCA WIND
GUSTS ARE EXPECTED OVER MUCH OF THIS TIME PERIOD OVER THE OPEN
WATERS. WE MAY EVEN SEE A BRIEF GALE FOR A TIME ON WEDNESDAY. THERE
ALSO WILL BE LULLS IN THE WIND...BUT TIMING THAT THIS FAR OUT IS
IMPOSSIBLE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 10 PM EST
MONDAY FOR CTZ002.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 1 PM EST
MONDAY FOR CTZ003-004.
MA...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 10 PM EST
MONDAY FOR MAZ002>004-008>011-026.
WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 1 PM EST
MONDAY FOR MAZ005-012>014-017.
NH...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 10 PM EST
MONDAY FOR NHZ011-012-015.
RI...WINTER WEATHER ADVISORY FROM 11 PM THIS EVENING TO 1 PM EST
MONDAY FOR RIZ001>004-006.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM TO 10 PM EST MONDAY FOR
ANZ231>234.
SMALL CRAFT ADVISORY FROM 3 AM MONDAY TO 7 AM EST TUESDAY FOR
ANZ235-237-254>256.
SMALL CRAFT ADVISORY FROM 7 AM MONDAY TO 7 AM EST TUESDAY FOR
ANZ250-251.
&&
$$
SYNOPSIS...SIPPRELL/FRANK
NEAR TERM...FRANK
SHORT TERM...SIPPRELL
LONG TERM...FRANK
AVIATION...FRANK/SIPPRELL
MARINE...SIPPRELL/FRANK
AREA FORECAST DISCUSSION
NWS NEW YORK NY
501 AM EST SAT DEC 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TOWARDS THE REGION TODAY...AND DRIFT INTO
NORTHERN NEW ENGLAND ON SUNDAY. LOW PRESSURE WILL APPROACH SUNDAY
NIGHT AND IMPACT THE NORTHEAST THROUGH THE FIRST HALF OF NEXT
WEEK. HIGH PRESSURE WILL BUILD IN FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN BAND OF PCPN IS NOW OFFSHORE PER RADAR AND STLT. HAVE
CANCELLED THE WINTER WX ADVY AS A RESULT. ONLY SOME RESIDUAL
POCKETS OF LIGHT RAIN AND SNOW SHOWING UP ON RADAR AND VERIFIED BY
OBS. SNOW HAS BEEN REPORTED DOWN TO KFRG AND KISP ON LI.
FOLLOWED THE HRRR TIL 11Z FOR THE RESIDUAL LGT PCPN THIS MRNG.
OTHERWISE...CLEARING SKIES AND NLY FLOW TODAY. EDGE OF THE CLOUD
SHIELD WAS INVOF PORT JERVIS...AND ADVECTING EWD...AT 330 AM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
MODIFYING ARCTIC HI WILL BUILD OVER THE CWA TNGT. MSAS ANALYSIS AT
8Z PLACED THE 1044 CENTER OF THE HI OVER ERN MT. THIS WILL PRODUCE
COLD TEMPS WITH WIDESPREAD TEENS EXPECTED ACROSS THE INTERIOR AND
PINE BARRENS. STRONG SUBSIDENCE BUT A FEW HIGH CLOUDS ARE LIKELY
TO FILTER IN FROM THE SW.
AN INCREASING HIGH OVC CAN BE EXPECTED ON SUN WITH BACKING MID AND
UPR LVL FLOW. CLOUDS WILL LOWER AND THICKEN IN THE AFTN. GFS TIME
HEIGHTS SHOW LIFT IS FAIRLY ROBUST AFT 18Z...SO IT WILL JUST BE A
MATTER OF HOW LONG IT TAKES FOR SATURATION AND PCPN...WHICH BASED
ON THE 00Z SUITE OF DATA WILL BE ALL SNOW WITH PERHAPS SOME RAIN
MIXED IN ON LI AND IN THE CITY. FCST HAS BEEN SPED UP WITH MOST
SPOTS WITH CHCS FOR SNOW BY DARK. BASED ON THE CURRENT TIMING OF
THE SYSTEM...LESS THAN AN INCH OF SNOW IS EXPECTED BY 5 PM.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A WINTRY MIX EXPECTED TO START THE WEEK AND THEN AN ARCTIC AIRMASS
FOR MID TO LATE WEEK.
WEATHER THROUGH THIS TIME PERIOD WILL BE CONTROLLED BY THE POLAR
VORTEX OVER HUDSON BAY...WHICH WILL ROTATE A SERIES OF SHORTWAVES
THROUGH THE NORTHERN US. MODELS IN DECENT AGREEMENT WITH ONE OF THESE
SHORTWAVES PHASING WITH A SHORTWAVE EJECTING OUT OF THE WESTERN
US...RESULTING IN A DEVELOPING LOW PRESSURE SYSTEM AFFECTING THE
REGION WITH A WINTRY MIX OF PRECIP SUNDAY NIGHT INTO MONDAY
MORNING. BASED ON CLOSLEY CLUSTERED CONSENSUS TRACK OF A DOUBLE
BARRELED COASTAL LOW...A TRANSITION TO RAIN WOULD BE EXPECTED
ALONG THE COAST BY MONDAY MORNING. ACROSS INTERIOR
AREAS...PARTICULARLY NW ZONES...A FEW INCHES OF SNOW AND SLEET ARE
POSSIBLE WITH EVEN A BRIEF TRANSITION TO FREEZING RAIN. SREF
PLUMES INDICATING A MEAN OF 3 TO 4 INCHES ACROSS FAR NW
ZONES...WITH GENERALLY AN INCH OR LESS FOR CITY COAST. THIS COULD
MAKE FOR A WINTRY MORNING COMMUTE FOR INTERIOR AREAS...WHILE AT
THE CITY/COAST ROADS SHOULD MAINLY BE WET WITH RAIN AND RISING
TEMPS.
MODELS ARE IN DECENT AGREEMENT WITH A TRAILING COLD FRONT PUSHING
THROUGH THE REGION WITH DRYING CONDITIONS LATE MONDAY...BUT THE
FRONT LINGERS CLOSE ENOUGH TO THE REGION MONDAY NIGHT INTO TUESDAY
FOR ADDITIONAL WAVES OF LOW PRESSURE TO POSSIBLY BRUSH THE REGION
WITH LIGHT WINTRY PRECIP. HAVE MAINTAINED SLIGHT CHANCE/CHANCE POPS
THROUGH THIS TIME BASED ON MODEL SPREAD.
THEN FOR THE MID TO LATE WEEK PERIOD...MODEL INDICATING SEVERAL
PIECES OF AN ARCTIC AIRMASS OVER CANADA SPILLING INTO THE NORTHERN
US. CURRENTLY HAVE TRENDED TEMPS TO STAY BELOW FREEZING FROM
WEDNESDAY THRU FRIDAY BASED ON ANOMALOUSLY COLD AIRMASS...WITH
POTENTIAL FOR TEMPS TO STRUGGLE TO REACH THE UPPER TEEN/LOWER 20S
FOR HIGHS LATE WEEK IF POLAR VORTEX DROPS INTO NORTHERN NEW
ENGLAND/SE CANADA AS DEPICTED BY SOME MODEL GUIDANCE. STAY TUNED.
&&
.AVIATION /10Z SATURDAY THROUGH WEDNESDAY/...
A WEAK WAVE OF LOW PRES WILL CONTINUE TO PUSH WELL OFFSHORE THIS
MORNING WITH HIGH PRESSURE BUILDING INTO THE REGION THIS AFTERNOON
THROUGH TONIGHT.
MAIN PRECIP SHIELD HAS PUSHED OFFSHORE...WITH MAINLY JUST DRIZZLE
AND ISOLATED LIGHT RASN SHOWERS EXPECTED THROUGH AROUND 10-12Z. WITH
TEMPS AT FREEZING AT KSWF POTETNIAL EXISTS FOR -FZDZ THROUGH AROUND
DAYBREAK.
IFR/MVFR CONDS ARE EXPECTED TO GRADUALLY IMPROVE FROM W TO E AFTER
11-13Z...WITH VFR SHOULD RETURN TO ALL TERMINALS BY 15Z.
MODERATE CONFIDENCE IN WIND FORECAST. ISOLD GUSTS AROUND 20 KT
POSSIBLE AT KLGA/KEWR THROUGH EARLY MORNING. WINDS/GUSTS DIMINISH
SAT AFTN/EVE.
.OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.TONIGHT AND SUN...VFR.
.SUN NIGHT...IFR. SNOW...THEN SNOW/SLEET/RAIN NEAR THE COAST AND
SNOW/SLEET ACROSS INTERIOR.
.MON...IFR. RAIN. WINTRY MIX ACROSS INTERIOR EARLY...THEN RAIN.
SE WINDS 10-15 KT...BCMG NW LATE.
.MON NIGHT...WINTRY MIX POSSIBLE. W WINDS AOB 10 KT.
.TUE...VFR. W WINDS AOB 10 KT.
.WED...VFR. W WIND 15-25 KT.
&&
.MARINE...
NLY FLOW WILL RESULT IN SCA CONDITIONS ON THE OCEAN TODAY. WINDS
AND SEAS WILL LINGER A BIT LONGER OFF MONTAUK...SO THE SCA HAS
BEEN EXTENDED THRU THE EVE FOR THE ERN MOST OCEAN ZONE. WINDS AND
SEAS WILL REMAIN BLW SCA LVLS ON SUN WITH HIPRES OVER THE WATERS.
SCA CONDITIONS LIKELY TO RETURN SUNDAY NIGHT INTO MONDAY MORNING
ONTHE OCEAN AND LI SOUND WATERS...POSSIBLE ELSEWHERE...AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. WINDS SHOULD DIMINISH BY MONDAY
AFTERNOON AS THE COMPLEX LOW PRESSURE SYSTEM WORKS THROUGH THE
REGION...BUT OCEAN SEAS SHOULD REMAIN AT SCA LEVELS. MARGINAL SCA
WINDS ARE POSSIBLE IN THE WAKE OF THE LOW MON NIGHT/EARLY
TUE...MAINLY ON THE OCEAN. THE NEXT TIME OF CONCERN WILL BE
TUESDAY NIGHT THROUGH WEDNESDAY WITH GALE CONDITIONS POSSIBLE AS
AN ARCTIC FRONT CROSSES THE WATERS.
&&
.HYDROLOGY...
WIDESPREAD SIGNIFICANT PCPN IS NOT EXPECTED THRU THE DAY ON SUN.
A STORM SYSTEM COULD BRING AROUND HALF INCH TO AN INCH LIQUID
EQUIVALENT TO THE HYDROLOGIC SERVICE AREA...FROM LATE SUNDAY
AFTERNOON THROUGH MONDAY NIGHT.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD
EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS
WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL
WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES
TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ353-
355.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ350.
&&
$$
SYNOPSIS...JMC/NV
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...NV
AVIATION...NV
MARINE...JMC/NV
HYDROLOGY...JMC/NV
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
414 AM EST SAT DEC 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TOWARDS THE REGION TODAY...AND DRIFT INTO
NORTHERN NEW ENGLAND ON SUNDAY. LOW PRESSURE WILL APPROACH SUNDAY
NIGHT AND IMPACT THE NORTHEAST THROUGH THE FIRST HALF OF NEXT
WEEK. HIGH PRESSURE WILL BUILD IN FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN BAND OF PCPN IS NOW OFFSHORE PER RADAR AND STLT. HAVE
CANCELLED THE WINTER WX ADVY AS A RESULT. ONLY SOME RESIDUAL
POCKETS OF LIGHT RAIN AND SNOW SHOWING UP ON RADAR AND VERIFIED BY
OBS. SNOW HAS BEEN REPORTED DOWN TO KFRG AND KISP ON LI.
FOLLOWED THE HRRR TIL 11Z FOR THE RESIDUAL LGT PCPN THIS MRNG.
OTHERWISE...CLEARING SKIES AND NLY FLOW TODAY. EDGE OF THE CLOUD
SHIELD WAS INVOF PORT JERVIS...AND ADVECTING EWD...AT 330 AM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
MODIFYING ARCTIC HI WILL BUILD OVER THE CWA TNGT. MSAS ANALYSIS AT
8Z PLACED THE 1044 CENTER OF THE HI OVER ERN MT. THIS WILL PRODUCE
COLD TEMPS WITH WIDESPREAD TEENS EXPECTED ACROSS THE INTERIOR AND
PINE BARRENS. STRONG SUBSIDENCE BUT A FEW HIGH CLOUDS ARE LIKELY
TO FILTER IN FROM THE SW.
AN INCREASING HIGH OVC CAN BE EXPECTED ON SUN WITH BACKING MID AND
UPR LVL FLOW. CLOUDS WILL LOWER AND THICKEN IN THE AFTN. GFS TIME
HEIGHTS SHOW LIFT IS FAIRLY ROBUST AFT 18Z...SO IT WILL JUST BE A
MATTER OF HOW LONG IT TAKES FOR SATURATION AND PCPN...WHICH BASED
ON THE 00Z SUITE OF DATA WILL BE ALL SNOW WITH PERHAPS SOME RAIN
MIXED IN ON LI AND IN THE CITY. FCST HAS BEEN SPED UP WITH MOST
SPOTS WITH CHCS FOR SNOW BY DARK. BASED ON THE CURRENT TIMING OF
THE SYSTEM...LESS THAN AN INCH OF SNOW IS EXPECTED BY 5 PM.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A WARM FRONT APPROACHES THE AREA INTO MONDAY. AS THE AREA OF LOW
PRESSURE MOVES INTO SOUTHEAST CANADA...IT WILL PUSH A COLD FRONT
ACROSS THE AREA. WITH ENOUGH COLD AIR IN PLACE...PRECIPITATION
WILL POSSIBLY START OUT AS SNOW AND/OR SNOW CHANGING TO A WINTRY
MIX SUNDAY NIGHT INTO EARLY MONDAY. AS WARMER AIR MOVES IN ON
MONDAY...THE PRECIPITATION IS EXPECTED TO CHANGE OVER TO RAIN. THE
FAR NORTHERN ZONES COULD HOLD ON THE WINTRY MIXTURE LONGER INTO
MONDAY MORNING...BEFORE THE WARM AIR PUSHES THROUGH.
AT THIS TIME...LIGHT SNOW/SLEET ACCUMULATIONS WOULD BE
POSSIBLE...BUT PRIMARILY INLAND. WHATEVER LITTLE ACCUMULATION THE
CITY/COAST COULD MANAGE WOULD BE WASHED AWAY FAIRLY QUICKLY BY RAIN
AND WARMING TEMPERATURES.
THE PRECIPITATION SHOULD COME TO AN END...AS THE SYSTEM MOVES
OFFSHORE MONDAY NIGHT WITH A CHANCE OF LINGERING PRECIPITATION
THROUGH TUESDAY MORNING AS A WEAK WAVE OF LOW PRESSURE SLIDES ACROSS
THE AREA. HIGH PRESSURE BUILDS IN FOR TUESDAY NIGHT THROUGH THE END
OF THE EXTENDED PERIOD WITH DRY WEATHER...BUT WITH COLDER THAN
NORMAL TEMPERATURES.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
A WEAK WAVE OF LOW PRES WILL CONTINUE TO PUSH WELL OFFSHORE THIS
MORNING WITH HIGH PRESSURE BUILDING INTO THE REGION THIS AFTERNOON
THROUGH TONIGHT.
MAIN PRECIP SHIELD HAS PUSHED OFFSHORE...WITH MAINLY JUST DRIZZLE
AND ISOLATED LIGHT RASN SHOWERS EXPECTED THROUGH AROUND 10-12Z. WITH
TEMPS AT FREEZING AT KSWF POTETNIAL EXISTS FOR -FZDZ THROUGH AROUND
DAYBREAK.
IFR/MVFR CONDS ARE EXPECTED TO GRADUALLY IMPROVE FROM W TO E AFTER
11-13Z...WITH VFR SHOULD RETURN TO ALL TERMINALS BY 15Z.
MODERATE CONFIDENCE IN WIND FORECAST. ISOLD GUSTS AROUND 20 KT
POSSIBLE AT KLGA/KEWR THROUGH EARLY MORNING. WINDS/GUSTS DIMINISH
SAT AFTN/EVE.
.OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.TONIGHT AND SUN...VFR.
.SUN NIGHT...IFR. SNOW...THEN SNOW/SLEET/RAIN NEAR THE COAST AND
SNOW/SLEET ACROSS INTERIOR.
.MON...IFR. RAIN. WINTRY MIX ACROSS INTERIOR EARLY...THEN RAIN.
SE WINDS 10-15 KT...BCMG NW LATE.
.MON NIGHT...WINTRY MIX POSSIBLE. W WINDS AOB 10 KT.
.TUE...VFR. W WINDS AOB 10 KT.
.WED...VFR. W WIND 15-25 KT.
&&
.MARINE...
NLY FLOW WILL RESULT IN SCA CONDITIONS ON THE OCEAN TODAY. WINDS
AND SEAS WILL LINGER A BIT LONGER OFF MONTAUK...SO THE SCA HAS
BEEN EXTENDED THRU THE EVE FOR THE ERN MOST OCEAN ZONE. WINDS AND
SEAS WILL REMAIN BLW SCA LVLS ON SUN WITH HIPRES OVER THE WATERS.
SCA CONDITIONS LIKELY TO RETURN SUNDAY NIGHT INTO MONDAY MORNING
ONTHE OCEAN AND LI SOUND WATERS...POSSIBLE ELSEWHERE...AHEAD OF AN
APPROACHING LOW PRESSURE SYSTEM. WINDS SHOULD DIMINISH BY MONDAY
AFTERNOON AS THE COMPLEX LOW PRESSURE SYSTEM WORKS THROUGH THE
REGION...BUT OCEAN SEAS SHOULD REMAIN AT SCA LEVELS. MARGINAL SCA
WINDS ARE POSSIBLE IN THE WAKE OF THE LOW MON NIGHT/EARLY
TUE...MAINLY ON THE OCEAN. THE NEXT TIME OF CONCERN WILL BE
TUESDAY NIGHT THROUGH WEDNESDAY WITH GALE CONDITIONS POSSIBLE AS
AN ARCTIC FRONT CROSSES THE WATERS.
&&
.HYDROLOGY...
WIDESPREAD SIGNIFICANT PCPN IS NOT EXPECTED THRU THE DAY ON SUN.
A STORM SYSTEM COULD BRING AROUND HALF INCH TO AN INCH LIQUID
EQUIVALENT TO THE HYDROLOGIC SERVICE AREA...FROM LATE SUNDAY
AFTERNOON THROUGH MONDAY NIGHT.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD
EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS
WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL
WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES
TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ353-
355.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ350.
&&
$$
SYNOPSIS...JMC/NV
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...NV
AVIATION...NV
MARINE...JMC/NV
HYDROLOGY...JMC/NV
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS NEW YORK NY
354 AM EST SAT DEC 7 2013
.SYNOPSIS...
HIGH PRESSURE WILL BUILD TOWARDS THE REGION TODAY...AND DRIFT INTO
NORTHERN NEW ENGLAND ON SUNDAY. LOW PRESSURE WILL APPROACH SUNDAY
NIGHT AND IMPACT THE NORTHEAST THROUGH THE FIRST HALF OF NEXT
WEEK. HIGH PRESSURE WILL BUILD IN FOR THE SECOND HALF OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAIN BAND OF PCPN IS NOW OFFSHORE PER RADAR AND STLT. HAVE
CANCELLED THE WINTER WX ADVY AS A RESULT. ONLY SOME RESIDUAL
POCKETS OF LIGHT RAIN AND SNOW SHOWING UP ON RADAR AND VERIFIED BY
OBS. SNOW HAS BEEN REPORTED DOWN TO KFRG AND KISP ON LI.
FOLLOWED THE HRRR TIL 11Z FOR THE RESIDUAL LGT PCPN THIS MRNG.
OTHERWISE...CLEARING SKIES AND NLY FLOW TODAY. EDGE OF THE CLOUD
SHIELD WAS INVOF PORT JERVIS...AND ADVECTING EWD...AT 330 AM.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SUNDAY/...
MODIFYING ARCTIC HI WILL BUILD OVER THE CWA TNGT. MSAS ANALYSIS AT
8Z PLACED THE 1044 CENTER OF THE HI OVER ERN MT. THIS WILL PRODUCE
COLD TEMPS WITH WIDESPREAD TEENS EXPECTED ACROSS THE INTERIOR AND
PINE BARRENS. STRONG SUBSIDENCE BUT A FEW HIGH CLOUDS ARE LIKELY
TO FILTER IN FROM THE SW.
AN INCREASING HIGH OVC CAN BE EXPECTED ON SUN WITH BACKING MID AND
UPR LVL FLOW. CLOUDS WILL LOWER AND THICKEN IN THE AFTN. GFS TIME
HEIGHTS SHOW LIFT IS FAIRLY ROBUST AFT 18Z...SO IT WILL JUST BE A
MATTER OF HOW LONG IT TAKES FOR SATURATION AND PCPN...WHICH BASED
ON THE 00Z SUITE OF DATA WILL BE ALL SNOW WITH PERHAPS SOME RAIN
MIXED IN ON LI AND IN THE CITY. FCST HAS BEEN SPED UP WITH MOST
SPOTS WITH CHCS FOR SNOW BY DARK. BASED ON THE CURRENT TIMING OF
THE SYSTEM...LESS THAN AN INCH OF SNOW IS EXPECTED BY 5 PM.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
A WARM FRONT APPROACHES THE AREA INTO MONDAY. AS THE AREA OF LOW
PRESSURE MOVES INTO SOUTHEAST CANADA...IT WILL PUSH A COLD FRONT
ACROSS THE AREA. WITH ENOUGH COLD AIR IN PLACE...PRECIPITATION
WILL POSSIBLY START OUT AS SNOW AND/OR SNOW CHANGING TO A WINTRY
MIX SUNDAY NIGHT INTO EARLY MONDAY. AS WARMER AIR MOVES IN ON
MONDAY...THE PRECIPITATION IS EXPECTED TO CHANGE OVER TO RAIN. THE
FAR NORTHERN ZONES COULD HOLD ON THE WINTRY MIXTURE LONGER INTO
MONDAY MORNING...BEFORE THE WARM AIR PUSHES THROUGH.
AT THIS TIME...LIGHT SNOW/SLEET ACCUMULATIONS WOULD BE
POSSIBLE...BUT PRIMARILY INLAND. WHATEVER LITTLE ACCUMULATION THE
CITY/COAST COULD MANAGE WOULD BE WASHED AWAY FAIRLY QUICKLY BY RAIN
AND WARMING TEMPERATURES.
THE PRECIPITATION SHOULD COME TO AN END...AS THE SYSTEM MOVES
OFFSHORE MONDAY NIGHT WITH A CHANCE OF LINGERING PRECIPITATION
THROUGH TUESDAY MORNING AS A WEAK WAVE OF LOW PRESSURE SLIDES ACROSS
THE AREA. HIGH PRESSURE BUILDS IN FOR TUESDAY NIGHT THROUGH THE END
OF THE EXTENDED PERIOD WITH DRY WEATHER...BUT WITH COLDER THAN
NORMAL TEMPERATURES.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS A WEAK WAVE OF LOW PRES EXITS TO THE E OVERNIGHT...PRECIPITATION
WILL COME TO AN END FROM NW TO SE. HIGH PRES BUILDS BACK IN ON
SAT.
P-TYPE IS ON THE VERGE OF CHANGING OVER TO -SN AT KSWF ALTHOUGH
PRECIP IS COMING TO AN END. A DEEP MOIST COLUMN IS STILL EXPECTED
TO PRODUCE DZ AND FZDZ AS TEMPS FALLING BELOW THE FREEZING MARK
LATE. CLOSER TO THE COAST...RAIN WILL GENERALLY PREVAIL...BUT
COULD MIX WITH -SNPL OR COMPLETELY CHANGEOVER TO -SN BRIEFLY BEFORE
DRIER AIR ALOFT WORKS IN RESULTING IN DZ. FZDZ IS POSSIBLE LATE
TONIGHT AT KHPN...BUT CONFIDENCE IN TEMP IS LOW AND THEREFORE HAVE
LEFT AS PLAIN -DZ FOR NOW. THIS WILL BE MONITORED.
GENERALLY EXPECT MVFR TO LOCALLY IFR CONDS THROUGH 10Z OR
SO...THEN IMPROVING CONDS W TO E THEREAFTER. VFR SHOULD RETURN TO
ALL TERMINALS BY 15Z.
MODERATE CONFIDENCE IN WIND FORECAST. ISOLD GUSTS AROUND 20 KT
POSSIBLE AT KLGA/KEWR THROUGH EARLY MORNING. WINDS/GUSTS DIMINISH
SAT AFTN/EVE.
.OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY...
.SAT NIGHT AND SUN...VFR.
.SUN NIGHT...IFR. SNOW...THEN SNOW/SLEET/RAIN NEAR THE COAST AND
SNOW/SLEET ACROSS INTERIOR.
.MON...IFR. RAIN. WINTRY MIX ACROSS INTERIOR EARLY...THEN RAIN.
SE WINDS 10-15 KT...BCMG NW LATE.
.MON NIGHT...WINTRY MIX POSSIBLE. W WINDS AOB 10 KT.
.TUE...VFR. W WINDS AOB 10 KT.
.WED...VFR. W WIND 15-25 KT.
&&
.MARINE...
NLY FLOW WILL RESULT IN SCA CONDITIONS ON THE OCEAN TODAY. WINDS
AND SEAS WILL LINGER A BIT LONGER OFF MONTAUK...SO THE SCA HAS
BEEN EXTENDED THRU THE EVE FOR THE ERN MOST OCEAN ZONE. WINDS AND
SEAS WILL REMAIN BLW SCA LVLS ON SUN WITH HIPRES OVER THE WATERS.
&&
.HYDROLOGY...
WIDESPREAD SIGNIFICANT PCPN IS NOT EXPECTED THRU THE DAY ON SUN.
A STORM SYSTEM COULD BRING AROUND HALF INCH TO AN INCH LIQUID
EQUIVALENT TO THE HYDROLOGIC SERVICE AREA...FROM LATE SUNDAY
AFTERNOON THROUGH MONDAY NIGHT.
&&
.EQUIPMENT...
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD
EMERGENCY BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS
WEATHER RADIO STATION KWO35 REMAINS OUT OF SERVICE. THE NATIONAL
WEATHER SERVICE IS WORKING WITH SEVERAL U.S. GOVERNMENT AGENCIES
TO ISOLATE AND RESOLVE THIS TECHNICAL PROBLEM.
DURING THIS TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TESTS OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR ANZ353-
355.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR ANZ350.
&&
$$
SYNOPSIS...JMC
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...FIG
AVIATION...
MARINE...JMC/NV
HYDROLOGY...JMC/FIG
EQUIPMENT...
AREA FORECAST DISCUSSION...UPDATE
NWS PEACHTREE CITY GA
1012 PM EST SUN DEC 8 2013
.EVENING UPDATE...
CURRENT TEMPS ACROSS THE AREA WILL BE VERY CLOSE TO THE OVERNIGHT
LOWS AS AREA TEMPS REMAIN NEARLY UNCHANGED INTO THE EARLY MONDAY
MORNING HOURS... WHEN TEMPS SHOULD BEGIN TO WARM SLIGHTLY FROM THE
SOUTH AS THE WARM FRONT CREEPS NORTH. RADAR SHOWS AN AREA OF RAIN
CONTINUING TO TRAIN ACROSS NORTH GA... AND ALTHO THIS AREA MAY SAG
SLIGHTLY MORE TO THE SOUTH AND EAST OVERNIGHT... STILL EXPECT THE
GREATER RAIN CHANCES AND QPF TOTALS TO BE MAINLY FOCUSED ACROSS
AREAS GENERALLY ALONG AND NORTH OF A FRANKLIN TO ATLANTA TO
GAINSVILLE LINE. RAINFALL TOTALS SO FAR OVER THE LAST 12 HOURS SHOW
A LARGE SWATH OF 1.00 TO 1.5 INCHES CENTERED NEAR A LINE FROM NEAR
ROME TO ELLIJAY. THIS AREA COULD SEE ANOTHER INCH OVERNIGHT... AND
WILL LIKELY PUSH MOST STREAMS TO NEAR OR ABOVE AT LEAST CAUTION
STAGE BY MORNING...WITH A FEW ISOLATED STREAMS POSSIBLY FLIRTING
WITH MINOR FLOOD. HOWEVER... STILL NOT EXPECTING WIDESPREAD FLOOD
PROBLEMS AS THE RAIN IS GENERALLY LIGHT... AND NOT RESULTING HEAVY
RUNOFF AT THIS TIME. HOWEVER... THE STEADY RAIN WILL WARRANT
MONITORING RIVERS AND STREAMS ACROSS NORTH GA CLOSELY OVERNIGHT.
HAVE TWEAKED TEMPS AND POPS FOR TONIGHT TO MATCH CURRENT TRENDS.
ALTHOUGH CANNOT RULE OUT AN ELEVATED RUMBLE OF THUNDER... HAVE
REMOVED ANY WORDING FOR THUNDER FOR THE REST OF TONIGHT AS EXPECT
THIS GREATER POTENTIAL TO BE OVER CENTRAL AND SOUTH AL FOR THE REST
OF TONIGHT. /39
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
/ISSUED AT 230 PM EST SUN DEC 8 2013/
HIGH PRESSURE WEDGE CONTINUES ACROSS MUCH OF GEORGIA THIS AFTERNOON.
A WARM FRONT IS ALSO SITUATED RIGHT ALONG THE GA/FLORIDA BORDER.
SOME CLEARING HAS OCCURRED ACROSS THE NORTHERN FLORIDA
PANHANDLE/SOUTH GA...AND MAY MAKE IT INTO THE SW CORNER OF THE CWFA.
HAVE TWEAKED THE CLOUD COVER FOR THE NEXT FEW HOURS...BUT THE CLOUDS
ARE EXPECTED TO FILL BACK IN OVERNIGHT.
REGIONAL RADAR PIC DOES SHOW A SHORTWAVE ACROSS SE MS/SW AL
ENHANCING CONVECTION THIS AFTERNOON. THIS FEATURE MAY HELP PRODUCE A
FEW THUNDERSTORMS ACROSS THE NW CWFA LATER THIS EVENING.
MIN/MAX TEMPS FOR OVERNIGHT AND MONDAY WILL DEPEND HEAVILY UPON THE
NORTHWARD PROGRESSION OF THE WARM FRONT. NOT AT ALL CONFIDENT THAT
THE BOUNDARY WILL MOVE MUCH FURTHER NORTH THAN THE SOUTHERN CWFA
OVERNIGHT. BL WINDS ARE NOT CONDUCIVE...PLUS ANY PRECIP FALLING WILL
HELP RE-ENFORCE THE COOLER WEDGE OVERNIGHT.
NORTHWARD PROGRESSION OF THE WARM FRONT/EROSION OF THE WEDGE IS MORE
LIKELY ON MONDAY AS A COLD FRONT APPROACHES FROM THE WEST. MORNING
LOW CLOUDS/FOG/DRIZZLE WILL GIVE WAY TO MORE WIDESPREAD RAINS AS THE
FRONT MOVES THROUGH. OVER THE PAST FEW DAYS...THE MODELS HAVE
CONTINUED TO SHIFT THE HEAVY RAINFALL AXIS NORTHWARD. THIS SEEMS
REASONABLE IN CORRELATION WITH THE CURRENT REGIONAL RADAR PIC. THE
NW CORNER OF THE CWFA SHOULD PICK UP THE MOST RAINFALL...GENERALLY
AROUND 2 INCHES EXPECTED. HOWEVER...ISOLATED SPOTS MAY RECEIVE
HIGHER AMOUNTS. HAVE OPTED NOT TO RAISE A FLOOD WATCH AT THIS TIME.
NLISTEMAA
.LONG TERM /TUESDAY THROUGH SUNDAY/...
/ISSUED AT 230 PM EST SUN DEC 8 2013/
MEDIUM RANGE MODEL TRENDS CONTINUE TO SHOW NO SIGNIFICANT DEPARTURES
FROM THE PREVIOUS RUN WITH THE UPPER-LEVEL PATTERN REMAINING FAIRLY
PROGRESSIVE AND MODERATE IN AMPLITUDE. BEST COLD AIR WITH THIS
PATTERN REMAINS WELL NORTH OF THE STATE...WITH NEAR SEASONALLY NORMAL
TEMPERATURES EXPECTED. NO SUBSTANTIAL CHANGES WERE MADE TO THE
EXISTING EXTENDED FORECAST GRIDS...SEE PREVIOUS LONG TERM FORECAST
DISCUSSION BELOW.
20
PREV LONG TERM DISCUSSION/TUESDAY THROUGH SATURDAY/...
UPPER TROUGH AXIS IS PUSHING THROUGH THE EASTERN THIRD OF THE
COUNTRY AS WE BEGIN THE EXTENDED...WITH MOST PRECIP MOVING OUT OF THE
SOUTHEAST BY LATE TUESDAY. GFS AND ECMWF ARE IN FAIRLY GOOD AGREEMENT
THROUGH THE FIRST PART OF THE PERIOD. ELONGATED FRONT SHOULD STALL
ACROSS SOUTH GEORGIA OR NORTHERN FLORIDA WHICH WILL KEEP SLIGHT
CHANCE POPS ACROSS SOUTHERN ZONES BUT FOR THE MOST PART THE MIDDLE
PART OF THE WEEK SHOULD BE DRY...ALBEIT COOL WITH THE PASSAGE OF THE
FRONT /ALTHOUGH EVEN THAT IS RELATIVE... EXPECTING AVERAGE TO JUST
SLIGHTLY BELOW AVERAGE TEMPS SO NOT PARTICULARLY COOL FOR THIS TIME
OF YEAR...JUST COOLER THAN MONDAY TEMPS/. A REINFORCING WAVE AND
MAINLY DRY COLD FRONT PUSHES THROUGH WEDNESDAY NIGHT WITH A COLDER
SURFACE HIGH SLIDING SOUTHEAST FROM THE NORTHERN PLAINS...SO THURSDAY
TEMPS SHOULD BE JUST A TAD COOLER THAN WEDNESDAY.
WEAK RIDGING BUILDS IN ALOFT THURSDAY NIGHT INTO FRIDAY WITH AN
INCREMENTAL INCREASE IN TEMPS IN ADVANCE OF A STRONG SHORTWAVE
OVER THE DESERT SOUTHWEST. AS THIS MOVES INTO THE SOUTHERN
PLAINS...IT SHOULD INDUCE SURFACE LOW DEVELOPMENT IN THE NORTHWEST
GULF. THIS IS WHERE THE GFS AND ECMWF BEGIN TO REALLY DIVERGE. THE
GFS HAS ONE MAIN SYSTEM AND BEGINS OVERSPREADING PRECIP ACROSS THE
SOUTHEAST FRIDAY NIGHT. THE ECMWF HAS A WEAK SHORTWAVE LIFTING
INTO THE PLAINS FRIDAY NIGHT...BRINGING LIGHT PRECIP TO THE
SOUTHEAST OVER THE WEEKEND...BUT HOLDS OFF ON THE MAIN SYSTEM
UNTIL AFTER THE END OF THE PERIOD. SO...SATURDAY COULD BE REALLY
WET /AS PER THE GFS/...OR IT COULD JUST BE A LITTLE WET /AS PER
THE ECMWF/. AS IS TYPICAL FOR THAT FAR OUT AND PLAYED THE MIDDLE
OF THE ROAD BY PAINTING CHANCE POPS EVERYWHERE. STAY TUNED FOR
LATER FORECASTS.
TDP
&&
.AVIATION...
/ISSUED AT 640 PM EST SUN DEC 8 2013/
00Z UPDATE...
A VERY MOIST AND MODERATELY UNSTABLE SW MID LEVEL FLOW WILL CONTINUE
TO OVERRUN THE COOL RIDGE OF HIGH PRESSURE AT THE SURFACE TO PRODUCE
LIFR CIGS AND 1-3SM -RADZ BR OVERNIGHT. RADAR SHOWS A BAND OF RAIN
SHOWERS SPREADING IN ACROSS NORTH GA AND THE HRRR MODEL SPREADS THIS
AREA OF RAIN INTO ATL BY 09Z TONIGHT...WHILE THE OTHER MODELS HOLD
THE HEAVIEST RAIN TO THE NORTH. WILL SHOW -RADZ OVERNIGHT WITH AREAS
OF -RA EXPECTED TO PERSIST ON MON. THIS WILL HELP HOLD PREVAILING
CIGS DOWN AROUND IFR LEVELS ON MON. CURRENT 10KT EAST WIND WILL VEER
SE AND DIMINISH TO AROUND 5KTS BY 09Z... SSW BY 15-17Z MON...THEN
WNW BY 21Z WITH SPEEDS AROUND 7-8KTS MON AFTERNOON. EXPECT FRONTAL
PASSAGE AT ATL BY 00Z TUE WITH INCREASING NW WINDS.
//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS... EXCEPT MEDIUM CONFIDENCE ON IFR
CIGS PREVAILING MONDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 41 59 49 57 / 70 80 50 60
ATLANTA 46 59 46 53 / 70 80 60 50
BLAIRSVILLE 41 50 41 52 / 100 90 70 60
CARTERSVILLE 46 54 42 50 / 90 90 80 50
COLUMBUS 56 70 56 62 / 40 80 50 50
GAINESVILLE 40 53 46 53 / 80 80 70 60
MACON 50 68 57 63 / 30 50 40 50
ROME 47 51 42 49 / 90 90 80 50
PEACHTREE CITY 48 63 48 55 / 60 80 50 50
VIDALIA 55 73 62 70 / 20 30 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA/39
LONG TERM....20
AVIATION...39
AREA FORECAST DISCUSSION...UPDATE
NWS PEACHTREE CITY GA
640 PM EST SUN DEC 8 2013
.SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/...
/ISSUED AT 230 PM EST SUN DEC 8 2013/
HIGH PRESSURE WEDGE CONTINUES ACROSS MUCH OF GEORGIA THIS AFTERNOON.
A WARM FRONT IS ALSO SITUATED RIGHT ALONG THE GA/FLORIDA BORDER.
SOME CLEARING HAS OCCURRED ACROSS THE NORTHERN FLORIDA
PANHANDLE/SOUTH GA...AND MAY MAKE IT INTO THE SW CORNER OF THE CWFA.
HAVE TWEAKED THE CLOUD COVER FOR THE NEXT FEW HOURS...BUT THE CLOUDS
ARE EXPECTED TO FILL BACK IN OVERNIGHT.
REGIONAL RADAR PIC DOES SHOW A SHORTWAVE ACROSS SE MS/SW AL
ENHANCING CONVECTION THIS AFTERNOON. THIS FEATURE MAY HELP PRODUCE A
FEW THUNDERSTORMS ACROSS THE NW CWFA LATER THIS EVENING.
MIN/MAX TEMPS FOR OVERNIGHT AND MONDAY WILL DEPEND HEAVILY UPON THE
NORTHWARD PROGRESSION OF THE WARM FRONT. NOT AT ALL CONFIDENT THAT
THE BOUNDARY WILL MOVE MUCH FURTHER NORTH THAN THE SOUTHERN CWFA
OVERNIGHT. BL WINDS ARE NOT CONDUCIVE...PLUS ANY PRECIP FALLING WILL
HELP RE-ENFORCE THE COOLER WEDGE OVERNIGHT.
NORTHWARD PROGRESSION OF THE WARM FRONT/EROSION OF THE WEDGE IS MORE
LIKELY ON MONDAY AS A COLD FRONT APPROACHES FROM THE WEST. MORNING
LOW CLOUDS/FOG/DRIZZLE WILL GIVE WAY TO MORE WIDESPREAD RAINS AS THE
FRONT MOVES THROUGH. OVER THE PAST FEW DAYS...THE MODELS HAVE
CONTINUED TO SHIFT THE HEAVY RAINFALL AXIS NORTHWARD. THIS SEEMS
REASONABLE IN CORRELATION WITH THE CURRENT REGIONAL RADAR PIC. THE
NW CORNER OF THE CWFA SHOULD PICK UP THE MOST RAINFALL...GENERALLY
AROUND 2 INCHES EXPECTED. HOWEVER...ISOLATED SPOTS MAY RECEIVE
HIGHER AMOUNTS. HAVE OPTED NOT TO RAISE A FLOOD WATCH AT THIS TIME.
NLISTEMAA
.LONG TERM /TUESDAY THROUGH SUNDAY/...
/ISSUED AT 230 PM EST SUN DEC 8 2013/
MEDIUM RANGE MODEL TRENDS CONTINUE TO SHOW NO SIGNIFICANT DEPARTURES
FROM THE PREVIOUS RUN WITH THE UPPER-LEVEL PATTERN REMAINING FAIRLY
PROGRESSIVE AND MODERATE IN AMPLITUDE. BEST COLD AIR WITH THIS
PATTERN REMAINS WELL NORTH OF THE STATE...WITH NEAR SEASONALLY NORMAL
TEMPERATURES EXPECTED. NO SUBSTANTIAL CHANGES WERE MADE TO THE
EXISTING EXTENDED FORECAST GRIDS...SEE PREVIOUS LONG TERM FORECAST
DISCUSSION BELOW.
20
PREV LONG TERM DISCUSSION/TUESDAY THROUGH SATURDAY/...
UPPER TROUGH AXIS IS PUSHING THROUGH THE EASTERN THIRD OF THE
COUNTRY AS WE BEGIN THE EXTENDED...WITH MOST PRECIP MOVING OUT OF THE
SOUTHEAST BY LATE TUESDAY. GFS AND ECMWF ARE IN FAIRLY GOOD AGREEMENT
THROUGH THE FIRST PART OF THE PERIOD. ELONGATED FRONT SHOULD STALL
ACROSS SOUTH GEORGIA OR NORTHERN FLORIDA WHICH WILL KEEP SLIGHT
CHANCE POPS ACROSS SOUTHERN ZONES BUT FOR THE MOST PART THE MIDDLE
PART OF THE WEEK SHOULD BE DRY...ALBEIT COOL WITH THE PASSAGE OF THE
FRONT /ALTHOUGH EVEN THAT IS RELATIVE... EXPECTING AVERAGE TO JUST
SLIGHTLY BELOW AVERAGE TEMPS SO NOT PARTICULARLY COOL FOR THIS TIME
OF YEAR...JUST COOLER THAN MONDAY TEMPS/. A REINFORCING WAVE AND
MAINLY DRY COLD FRONT PUSHES THROUGH WEDNESDAY NIGHT WITH A COLDER
SURFACE HIGH SLIDING SOUTHEAST FROM THE NORTHERN PLAINS...SO THURSDAY
TEMPS SHOULD BE JUST A TAD COOLER THAN WEDNESDAY.
WEAK RIDGING BUILDS IN ALOFT THURSDAY NIGHT INTO FRIDAY WITH AN
INCREMENTAL INCREASE IN TEMPS IN ADVANCE OF A STRONG SHORTWAVE
OVER THE DESERT SOUTHWEST. AS THIS MOVES INTO THE SOUTHERN
PLAINS...IT SHOULD INDUCE SURFACE LOW DEVELOPMENT IN THE NORTHWEST
GULF. THIS IS WHERE THE GFS AND ECMWF BEGIN TO REALLY DIVERGE. THE
GFS HAS ONE MAIN SYSTEM AND BEGINS OVERSPREADING PRECIP ACROSS THE
SOUTHEAST FRIDAY NIGHT. THE ECMWF HAS A WEAK SHORTWAVE LIFTING
INTO THE PLAINS FRIDAY NIGHT...BRINGING LIGHT PRECIP TO THE
SOUTHEAST OVER THE WEEKEND...BUT HOLDS OFF ON THE MAIN SYSTEM
UNTIL AFTER THE END OF THE PERIOD. SO...SATURDAY COULD BE REALLY
WET /AS PER THE GFS/...OR IT COULD JUST BE A LITTLE WET /AS PER
THE ECMWF/. AS IS TYPICAL FOR THAT FAR OUT AND PLAYED THE MIDDLE
OF THE ROAD BY PAINTING CHANCE POPS EVERYWHERE. STAY TUNED FOR
LATER FORECASTS.
TDP
&&
.AVIATION...
00Z UPDATE...
A VERY MOIST AND MODERATELY UNSTABLE SW MID LEVEL FLOW WILL CONTINUE
TO OVERRUN THE COOL RIDGE OF HIGH PRESSURE AT THE SURFACE TO PRODUCE
LIFR CIGS AND 1-3SM -RADZ BR OVERNIGHT. RADAR SHOWS A BAND OF RAIN
SHOWERS SPREADING IN ACROSS NORTH GA AND THE HRRR MODEL SPREADS THIS
AREA OF RAIN INTO ATL BY 09Z TONIGHT...WHILE THE OTHER MODELS HOLD
THE HEAVIEST RAIN TO THE NORTH. WILL SHOW -RADZ OVERNIGHT WITH AREAS
OF -RA EXPECTED TO PERSIST ON MON. THIS WILL HELP HOLD PREVAILING
CIGS DOWN AROUND IFR LEVELS ON MON. CURRENT 10KT EAST WIND WILL VEER
SE AND DIMINISH TO AROUND 5KTS BY 09Z... SSW BY 15-17Z MON...THEN
WNW BY 21Z WITH SPEEDS AROUND 7-8KTS MON AFTERNOON. EXPECT FRONTAL
PASSAGE AT ATL BY 00Z TUE WITH INCREASING NW WINDS.
//ATL CONFIDENCE...00Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS... EXCEPT MEDIUM CONFIDENCE ON IFR
CIGS PREVAILING MONDAY AFTERNOON.
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 41 59 49 57 / 70 80 50 60
ATLANTA 46 59 46 53 / 70 80 60 50
BLAIRSVILLE 41 50 41 52 / 100 90 70 60
CARTERSVILLE 46 54 42 50 / 90 90 80 50
COLUMBUS 56 70 56 62 / 40 80 50 50
GAINESVILLE 40 53 46 53 / 80 80 70 60
MACON 50 68 57 63 / 30 50 40 50
ROME 47 51 42 49 / 90 90 80 50
PEACHTREE CITY 48 63 48 55 / 60 80 50 50
VIDALIA 55 73 62 70 / 20 30 30 50
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...NLISTEMAA/39
LONG TERM....20
AVIATION...39
AREA FORECAST DISCUSSION
NWS POCATELLO ID
428 AM MST SAT DEC 7 2013
.UPDATE...UPON FURTHER INSPECTION OF TEMPS AND WINDS WE DECIDED TO
ISSUE A WIND CHILL WARNING FOR UPPER SNAKE RIVER PLAIN FOR TONIGHT
THROUGH TOMORROW MORNING. WINDS WILL REMAIN BREEZY AS THIS UPPER
LOW MOVES EAST...AND WITH A NORTHERLY FLOW BEHIND IT TEMPERATURES
WILL BEGIN TO PLUNGE ONCE AGAIN. WIND CHILL VALUES OF -15 TO -25
ARE LIKELY IN THIS AREA. MANY OTHER AREAS IN SE ID WILL LIKELY
REACH WIND CHILL VALUES OF AT LEAST -10.
&&
.PREV DISCUSSION... /ISSUED 254 AM MST SAT DEC 7 2013/
SHORT TERM...TODAY THROUGH SUNDAY.
WATER VAPOR IMAGERY SHOWS AN UPPER LOW POSITIONED OVER CENTRAL
OREGON EARLY THIS MORNING WITH A GOOD PUSH OF MOISTURE STREAMING
NORTH INTO IDAHO. AS THIS LOW MOVES EAST...SE ID WILL SEE SNOW
THROUGH THE DAY TODAY WITH THE CENTRAL MOUNTAINS ALREADY RECEIVING
SNOW. WITH THE COLDER TEMPERATURES THAT HAVE SET IN... SNOW RATIOS
ARE EXPECTED TO BE AROUND 20 TO 1 MEANING WE WILL HAVE VERY LIGHT
FLUFFY SNOW. EXPECTING WINDS TO PICK UP WITH GUSTS AROUND 25 MPH
IN THE EASTERN MAGIC VALLEY... LOWER SNAKE HIGHLANDS... SOUTH
CENTRAL HIGHLANDS AND CARIBOU HIGHLANDS SO MADE MENTION OF SOME
BLOWING SNOW TO GO WITH THE WINTER WEATHER ADVISORY CURRENTLY IN
EFFECT. THE HRRR IS SHOWING THE BIGGEST PUSH OF SNOWFALL AFTER 11
AM TODAY WHICH IS PRETTY IN LINE WITH THE NAM. THROUGH SUNDAY
MORNING... VALLEY SITES COULD SEE 1 TO 4 INCHES AND MOUNTAIN AREAS
COULD SEE 4 TO 8 INCHES WITH SOME HIGHEST PEAKS SEEING 9 INCHES OF
NEW SNOW. SNOWFALL WILL BEGIN TAPERING OFF SUNDAY MORNING. EP
LONG TERM...MONDAY THROUGH SATURDAY.
NORTHERLY FLOW WILL PERSIST INTO MIDWEEK WHEN THE FLOW BECOMES
NORTHWESTERLY. THE EXTREME COLD WILL PERSIST INTO MIDWEEK. TEMPS
WILL WARM WHEN THE FLOW BEGINS TO TURN. SOME WEAK SHORTWAVE TROUGHS
WILL MOVE THROUGH THE REGION WHICH COULD KICK OFF AN ISOLATED SNOW
SHOWER IN THE MOUNTAINS AND HIGHLANDS FOR THE FIRST PART OF THE
WEEK. MODELS HAVE CHANGED DRASTICALLY WITH THE HANDLING OF THE NEXT
SYSTEM ARRIVING LATER IN THE WEEK. GENERALLY...THE MODELS HAVE
WEAKENED THIS SYSTEM SUBSTANTIALLY. HAVE LOWERED PRECIPITATION
CHANCES SOME GIVEN THE CHANGE...BUT STILL CONTINUING TO MENTION SOME
SNOW IN CASE THE MODELS FLIP FLOP. TEMPS WILL CONTINUE TO WARM INTO
LATE WEEK AND COULD BE CLOSER TO NORMAL BY THE END OF THE WEEK.
VALLE
AVIATION...A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE REGION
TODAY. EXPECT WIDESPREAD SNOW ACROSS MUCH OF THE AREA. REDUCED
CEILINGS AND VISIBILITIES ARE A GOOD BET TODAY. CONDITIONS WILL
IMPROVE TONIGHT...ESPECIALLY OVERNIGHT.
VALLE
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING IDZ017-021.
WIND CHILL WARNING FROM 11 PM THIS EVENING TO 11 AM MST SUNDAY
IDZ020.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING IDZ022>025.
&&
$$
AREA FORECAST DISCUSSION
NWS POCATELLO ID
254 AM MST SAT DEC 7 2013
.SHORT TERM...TODAY THROUGH SUNDAY.
WATER VAPOR IMAGERY SHOWS AN UPPER LOW POSITIONED OVER CENTRAL
OREGON EARLY THIS MORNING WITH A GOOD PUSH OF MOISTURE STREAMING
NORTH INTO IDAHO. AS THIS LOW MOVES EAST...SE ID WILL SEE SNOW
THROUGH THE DAY TODAY WITH THE CENTRAL MOUNTAINS ALREADY RECEIVING
SNOW. WITH THE COLDER TEMPERATURES THAT HAVE SET IN... SNOW RATIOS
ARE EXPECTED TO BE AROUND 20 TO 1 MEANING WE WILL HAVE VERY LIGHT
FLUFFY SNOW. EXPECTING WINDS TO PICK UP WITH GUSTS AROUND 25 MPH
IN THE EASTERN MAGIC VALLEY... LOWER SNAKE HIGHLANDS... SOUTH
CENTRAL HIGHLANDS AND CARIBOU HIGHLANDS SO MADE MENTION OF SOME
BLOWING SNOW TO GO WITH THE WINTER WEATHER ADVISORY CURRENTLY IN
EFFECT. THE HRRR IS SHOWING THE BIGGEST PUSH OF SNOWFALL AFTER 11
AM TODAY WHICH IS PRETTY IN LINE WITH THE NAM. THROUGH SUNDAY
MORNING... VALLEY SITES COULD SEE 1 TO 4 INCHES AND MOUNTAIN AREAS
COULD SEE 4 TO 8 INCHES WITH SOME HIGHEST PEAKS SEEING 9 INCHES OF
NEW SNOW. SNOWFALL WILL BEGIN TAPERING OFF SUNDAY MORNING. EP
.LONG TERM...MONDAY THROUGH SATURDAY.
NORTHERLY FLOW WILL PERSIST INTO MIDWEEK WHEN THE FLOW BECOMES
NORTHWESTERLY. THE EXTREME COLD WILL PERSIST INTO MIDWEEK. TEMPS
WILL WARM WHEN THE FLOW BEGINS TO TURN. SOME WEAK SHORTWAVE TROUGHS
WILL MOVE THROUGH THE REGION WHICH COULD KICK OFF AN ISOLATED SNOW
SHOWER IN THE MOUNTAINS AND HIGHLANDS FOR THE FIRST PART OF THE
WEEK. MODELS HAVE CHANGED DRASTICALLY WITH THE HANDLING OF THE NEXT
SYSTEM ARRIVING LATER IN THE WEEK. GENERALLY...THE MODELS HAVE
WEAKENED THIS SYSTEM SUBSTANTIALLY. HAVE LOWERED PRECIPITATION
CHANCES SOME GIVEN THE CHANGE...BUT STILL CONTINUING TO MENTION SOME
SNOW IN CASE THE MODELS FLIP FLOP. TEMPS WILL CONTINUE TO WARM INTO
LATE WEEK AND COULD BE CLOSER TO NORMAL BY THE END OF THE WEEK.
VALLE
&&
.AVIATION...A LOW PRESSURE SYSTEM WILL MOVE THROUGH THE REGION
TODAY. EXPECT WIDESPREAD SNOW ACROSS MUCH OF THE AREA. REDUCED
CEILINGS AND VISIBILITIES ARE A GOOD BET TODAY. CONDITIONS WILL
IMPROVE TONIGHT...ESPECIALLY OVERNIGHT.
VALLE
&&
.PIH WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING IDZ017-021.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING IDZ022>025.
&&
$$
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
111 PM EST SAT DEC 7 2013
.SYNOPSIS...
THE FRONT WILL THEN PUSH FARTHER SOUTH TO OFF THE GEORGIA COAST
LATER TODAY INTO SUNDAY MORNING...AS COLD HIGH PRESSURE BUILDS
FROM THE UPPER MIDWEST TO THE EASTERN GREAT LAKES. ONE AREA OF LOW
PRESSURE WILL MOVE NORTHEAST JUST WEST OF THE APPALACHIANS SUNDAY
INTO MONDAY MORNING...WHILE A SECOND LOW PRESSURE AREA TRACKS
NORTHEAST JUST OFF THE MID ATLANTIC COAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT CONTINUES TO PUSH WELL SOUTH OF THE AREA. THE ONLY RAIN
LEFT IS MAINLY OVER NORTHEAST NORTH CAROLINA. THIS SHOULD PUSH TO
THE SOUTH OF THE AREA IN THE NEXT COUPLE OF AREAS. THIS FOLLOWS
THE HRRR DEPICTION OF THE ECHOS. WITH THE CONTINUED NORTHEAST
EXCEPT ACRS THE FAR NORTH...EXPECT SKIES TO REMAIN CLOUDY/MOSTLY
CLOUDY AS LOW LEVEL N/NE FLOW TENDS TO KEEP IN THE LOW LEVEL
MOISTURE EVEN AS BULK OF THE COLUMN DRIES OUT. LIKE THE GRIDDED
LAMP TEMPS WHICH KEEP TEMPERATURES VERY STEADY THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
N-NE SFC WINDS WILL CONTINUE TO FUNNEL COLDER AIR INTO THE MID ATLC
REGION TONIGHT...SETTING THE THE STAGE FOR THE WINTER PRECIP EVENT
SUN. JUST S CHC FOR LIGHT RAIN ACRS THE FAR SOUTH THIS
EVENING...OTHERWISE PARTLY TO MOSTLY CLOUDY WITH LOWS IN THE MID-
UPPER 20S N TO THE MID-UPPER 30S SE. HEADLINE-WISE...ONLY CHANGE
HAS BEEN TO ADD MECKLENBURG COUNTY TO THE WATCH. PER COORDINATION
W/ SURROUNDING OFFICES AND BASED ON LATEST THINKING...THERE
REMAINS A LOT OF UNCERTAINTY IN QPF AMOUNTS AND SUBSEQUENT ICE
ACCUMULATION ESPECIALLY AREAS SOUTH OF FARMVILLE. ALSO DID RAISE
AN ADVSY YET AS THIS IS MAINLY STILL 3RD PERIOD.
LATEST 00Z MODELS HAVE BEEN FAIRLY CONSISTENT COMPARED TO THE PAST
FEW CYCLES...ALTHOUGH ONE THING OF NOTE ON BOTH THE NAM/GFS BUFKIT
SOUNDINGS IS A FAIRLY SHORT TIME-FRAME WHEN THERE IS SATURATION
THROUGH THE -10C TO -20C LAYER (DENDRITIC GROWTH LAYER). THIS IS
RATHER PRONOUNCED ACRS THE SOUTHERN 1/2 OF THE CWA. AS IS OFTEN
THE CASE IN THESE OVERRUNNING EVENTS THERE IS INITIALLY SOME DRY
AIR IN THE LOW LEVELS...BUT WHAT WILL LIKELY OVERCOME THAT RATHER
QUICKLY IS STRONG FRONTOGENESIS. BOTH THE NAM AND GFS SHOW VERY
STRONG FORCING BY 12Z ACRS SOUTHERN VA...THEN RAPIDLY LIFT THIS OFF
TO THE NORTH FROM 18Z/SUN TO 00Z/MON. THIS OFTEN AIDS THE PRECIP
IN COMING IN FAST...AND THIS IS THE MAIN REASON MECKLENBURG HAS
BEEN ADDED TO THE WATCH (COULD SEE ACCUMULATING ICE HERE PRIOR TO
DAYBREAK SUN). HOWEVER...CONFIDENCE IN RECEIVING 0.25" OF ICE (OR
GREATER) IS NOT HIGH ENOUGH TO TRANSITION TO A WARNING IN THE
SOUTHERN PIEDMONT ZONES SINCE THE PRECIP MAY BECOME RATHER LIGHT
BY LATE MORNING AND BEYOND AS THE -10C TO -20 C RAPIDLY DRIES OUT
AND THE FORCING LIFTS NORTH. CONFIDENCE FOR 0.25" ICE IS HIGHEST
ACRS THE NW ZONES AS THE DRYING IS LESS PRONOUNCED THROUGH THE
AFTN HRS AND THIS IS ALSO WHERE SFC TEMPS WILL STAY THE COLDEST THE
LONGEST...PERHAPS IN THE UPPER 20S IN WESTERN LOUISA/FLUVANNA
THROUGH MOST OF THE DAY. THE MOST DIFFICULT REGION WITH RESPECT TO
ICE ACCUMULATION WILL PROBABLY BE METRO RICHMOND...AND IT IS
LIKELY THAT AN ADVISORY WILL BE NEEDED ALONG A SLIVER OF COUNTIES BORDERING
THE WATCH (AS WELL AS PART OF THE WATCH THAT MAY NOT GET
TRANSITIONED TO A WARNING). THESE AREAS WILL TEND TO HAVE HIGHS
IN THE MID 30S...BUT WILL BE AT OR JUST BELOW 32 F THROUGH MUCH OF
THE AFTN. THE MD ERN SHORE MAY SEE A FEW HRS OF SLEET/SNOW AND
PERHAPS FREEZING RAIN BUT EXPECT THE MARINE LAYER TO QUICKLY CHANGE
P-TYPE TO ALL RAIN NOT MUCH AFTER 18Z. EXPECT TEMPS TO BE WARM
ENOUGH OVER THE VA ERN SHORE...SE VA AND NE NC FOR PCPN TO BE JUST
RAIN FM THE START. HIGHS RANGE FROM AROUND 50 NE NC COAST TO
AROUND 30 F IN LOUISA COUNTY.
WARMER AIR (TEMPS RISING ABV FREEZING) WILL GRADUALLY WORK ITS WAY
NW INTO THE PIEDMONT SUN EVENING...BUT MAY NEVER MAKE IT TO
WESTERN LOUISA/FLUVANNA AND PERHAPS CUMBERLAND/GOOCHLAND. EXTENDED
PORTIONS OF THE WATCH THROUGH 12Z/MON AS NEXT SHORTWAVE PUSHES
INTO THE REGION FROM THE WEST BY 06Z...ENHANCING PRECIP (AND
SHOULD THIS STILL BE FREEZING RAIN THERE WOULD BE ADDITIONAL ICE
ACCUMULATION).
LOWS SUN NGT REMAINING NEARLY STEADY AROUND 30 F NW...TO THE UPPER
40S NC COASTAL AREAS.
STILL MUCH UNCERTAINTY REMAINS WITH THIS SYSTEM...SO ANY
WATCH...WARNING OR ADVISORY HEADLINES FOR COUNTIES COULD CHANGE
DURING THE NEXT 24 HOURS OR SO.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
GFS/NAM DIFFER WRT FRONTAL POSITION MONDAY. NAM IS FURTHER NORTH
WHERE BEST LIFT AND SUPPORT FOR PCPN WILL BE WHILE THE GFS/ECMWF
IS FURTHER SOUTH WITH COPIOUS AMOUNTS OF MOISTURE ACROSS THE REGION.
TSCTNS DO AGREE ON ENOUGH MOISTURE FOR CLOUDY SKIES AND AT LEAST A
GOOD POTENTIAL FOR A FEW HUNDREDTHS OF QPF EVEN IN THE SOUTH.
RAISED POPS TO LIKELY ALL AREAS BUT QPF-WISE THIS TIME PERIOD WILL
FOCUS OVER THE NORTH. THE FRONTAL POSITION ALONG WITH ANY
RESIDUAL ICE ON THE GROUND WILL MAKE FOR A WIDE RANGE IN TEMPS.
KEPT HIGHS IN THE MID 40S IN COUNTIES THAT MAY HAVE SOME MORNING
ICE...RANGING TO AROUND 60 F FAR SOUTHERN AREAS.
ANOTHER WAVE OF LOW PRESSURE PROGGED TO ENHANCE PCPN ALONG THE
FRONT AS IT MOVES SOUTH ACROSS THE FA MONDAY NIGHT. IN ADDITION...
JUST ENOUGH COLD AIR IS PROGGED ACROSS NORTHERN MOST COUNTYS FOR
PCPN TO BECOME MIXED WITH SOME WET SNOW LATE. CHC POPS ALL AREAS
WITH LOWS FROM THE L30S NORTH TO L40S SOUTH.
BOTH GFS/ECMWF CONT TO SHOW A THIRD WAVE OF LOW PRESSURE MOVING NE
ALONG THE BOUNDARY CONTINUING THE PCPN CHCS ACROSS THE AREA TUE.
DESPITE LOWERING THICKNESSES...TEMPS EXPECTED TO BE WARM ENOUGH FOR
RAIN. HIGHS NEAR 40 NORTH TO L50S SOUTH.
HIGH PRESSURE ACROSS THE NATIONS MID SECTION FINALLY PUSHES FRONTAL
BOUNDARY AND ASSOCIATED MOISTURE SOUTH AND EAST OF FA TUESDAY NIGHT.
WILL SHOW DECREASING CLOUDINESS. CAA RESULTS IN TEMPS DROPPING INTO
THE 20S TO L30S SERN COASTAL AREAS.
COLD & DRY FOR THE REST OF THE PERIOD. HIGHS WED & FRI IN THE U30S
TO U40S. THURS TO BE THE COLDEST WITH HIGHS IN THE M30S-L40S. LOWS
20-30...SOME TEENS POSSIBLE IN NORMALLY COLDER SPOTS.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
COLD FRONT HAS PUSHED WELL INTO NC AND STRONG N-NE FLOW WILL
GRADUALLY PUSH COLDER AIR INTO THE REGION. MOST PRECIP HAS
DIMINISHED EXCEPT A LITTLE SCATTERED RAIN OVER NE NC. EXPECT A
PERIOD OF VFR CONDS OVER SBY/RIC/PHF THIS AFTN AND TONIGHT...WITH
MOSTLY MVFR CONDS AT ORF AND ECG AS POST FRONTAL MVFR CLOUDS
LINGER OVER SE VA AND NE NC. A WAVE OF LOW PRES WILL APPROACH THE
MID ATL REGION OVERNIGHT AND BEGIN A PERIOD OF RAIN AND MIXED
WINTRY PRECIP EARLY SUN MORNING INTO THE AFTN AND EVENING. TEMPS
FOR ECG/ORF/PHF ARE EXPECTED TO REMAIN AT OR ABOVE FREEZING SO THE
PRECIP SHOULD BE MOSTLY RAIN FOR THOSE TAF SITES. HOWEVER...CANNOT
NOT RULE OUT THE CHC FOR A BRIEF PERIOD OF SOME SLEET OR FREEZING
RAIN FOR PHF EARLY. RIC IS EXPECTED TO SEE SOME SLEET AND FREEZING
RAIN BEGIN BETWEEN 5 AM AND 7 AM SUNDAY AND THIS COULD LAST INTO
THE EARLY AFTN BEFORE TEMPS RISE ABOVE FREEZING. THE WX SHOULD
BEGIN 1 TO 2 HRS LATER AT SBY PSBLY BEGINNING AS MIX OF
RAIN/SLEET/SNOW BEFORE CHANGING TO SLEET AND SNOW DURING THE MID
MORNING. WINDS WILL CONTINUE TO BE MOSTLY NE DURING THE PERIOD
WITH PSBL GUSTS TO 20-25 KTS. IFR CONDS WILL PREVAIL THRU THE
MORNING AND AFTN FOR MOST AREAS.
OUTLOOK... IFR CEILINGS ARE LIKELY TO PERSIST SUN NIGHT/MON WITH
PERIODS OF RAIN PSBLY LAST INTO TUE AT EACH OF THE TAF SITES.
CONDITIONS IMPROVE BY TUESDAY NIGHT.
&&
.MARINE...
ALL SCA HEADLINES HAVE BEEN PUT INTO EFFECT WITH THIS FORECAST
PACKAGE AS CONDITIONS ARE ALREADY AT SCA THRESHOLDS OR WILL BE THERE
BY LATER THIS MORNG. COLD FRNT CURRENTLY STRETCHED ALONG THE NC/VA
BORDER WILL SLOWLY SLIDE SOUTH TDY...WITH A STRONG CAA SURGE
FOLLOWING THE FROPA LEADING TO 20-25 KT NLY WINDS OVR THE WTRS
(15-20 KT OVR THE RIVERS). WINDS SLOWLY DIMINISH TNGT AS THE FRNT
PUSHES FARTHER SOUTH OF THE AREA...SO WILL DROP HEADLINES FOR THE
RIVERS AT 06Z THEN THE NRN BAY AT 12Z. STILL THINK WINDS WILL STAY
IN THE 15-20 KT RANGE OVR THE SRN BAY INTO SUN SO WILL END THE
HEADLINE THERE AT THE END OF THE THIRD PERIOD. AS FOR SEAS OVR CSTL
WTRS FOR TDY THRU SUN...EXPECT MAINLY 4-5 FT SEAS AND UP TO 6-7 FT
OVR SRN CSTL WTRS.
WINDS SHIFT TO THE SW AND CONDITIONS IMPROVE MON WITH SEAS AROUND 4
FT. ANOTHER COLD FRNT PUSHES THROUGH THE REGION MON NGT/TUE
MORNG...WITH SCA CONDITIONS AGAIN PSBL.
&&
.TIDES/COASTAL FLOODING...
GIVEN THE ASTRONOMICAL TIMING OF THE EVENT...PREDICTED TIDES AND
LEVELS ARE PROGGED TO REMAIN BLO ANY CRITICAL THRESHOLDS THROUGH THE
WEEKEND.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR VAZ048-049-060>064-068-069.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING
FOR VAZ065>067.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR ANZ632-634-650-
652-654-656-658.
SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR ANZ635>638.
SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR ANZ630-631-633.
&&
$$
SYNOPSIS...LKB
NEAR TERM...LKB/JAB
SHORT TERM...LKB/TMG
LONG TERM...MPR
AVIATION...JEF
MARINE...MAS
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
1001 AM EST SAT DEC 7 2013
.SYNOPSIS...
THE FRONT WILL THEN PUSH FARTHER SOUTH TO OFF THE GEORGIA COAST
LATER TODAY INTO SUNDAY MORNING...AS COLD HIGH PRESSURE BUILDS
FROM THE UPPER MIDWEST TO THE EASTERN GREAT LAKES. ONE AREA OF LOW
PRESSURE WILL MOVE NORTHEAST JUST WEST OF THE APPALACHIANS SUNDAY
INTO MONDAY MORNING...WHILE A SECOND LOW PRESSURE AREA TRACKS
NORTHEAST JUST OFF THE MID ATLANTIC COAST.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
COLD FRONT CONTINUES TO PUSH WELL SOUTH OF THE AREA. THE ONLY RAIN
LEFT IS MAINLY OVER NORTHEAST NORTH CAROLINA. THIS SHOULD PUSH TO
THE SOUTH OF THE AREA IN THE NEXT COUPLE OF AREAS. THIS FOLLOWS
THE HRRR DEPICTION OF THE ECHOS. WITH THE CONTINUED NORTHEAST
EXCEPT ACRS THE FAR NORTH...EXPECT SKIES TO REMAIN CLOUDY/MOSTLY
CLOUDY AS LOW LEVEL N/NE FLOW TENDS TO KEEP IN THE LOW LEVEL
MOISTURE EVEN AS BULK OF THE COLUMN DRIES OUT. LIKE THE GRIDDED
LAMP TEMPS WHICH KEEP TEMPERATURES VERY STEADY THROUGH THE DAY.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
N-NE SFC WINDS WILL CONTINUE TO FUNNEL COLDER AIR INTO THE MID ATLC
REGION TONIGHT...SETTING THE THE STAGE FOR THE WINTER PRECIP EVENT
SUN. JUST S CHC FOR LIGHT RAIN ACRS THE FAR SOUTH THIS
EVENING...OTHERWISE PARTLY TO MOSTLY CLOUDY WITH LOWS IN THE MID-
UPPER 20S N TO THE MID-UPPER 30S SE. HEADLINE-WISE...ONLY CHANGE
HAS BEEN TO ADD MECKLENBURG COUNTY TO THE WATCH. PER COORDINATION
W/ SURROUNDING OFFICES AND BASED ON LATEST THINKING...THERE
REMAINS A LOT OF UNCERTAINTY IN QPF AMOUNTS AND SUBSEQUENT ICE
ACCUMULATION ESPECIALLY AREAS SOUTH OF FARMVILLE. ALSO DID RAISE
AN ADVSY YET AS THIS IS MAINLY STILL 3RD PERIOD.
LATEST 00Z MODELS HAVE BEEN FAIRLY CONSISTENT COMPARED TO THE PAST
FEW CYCLES...ALTHOUGH ONE THING OF NOTE ON BOTH THE NAM/GFS BUFKIT
SOUNDINGS IS A FAIRLY SHORT TIME-FRAME WHEN THERE IS SATURATION
THROUGH THE -10C TO -20C LAYER (DENDRITIC GROWTH LAYER). THIS IS
RATHER PRONOUNCED ACRS THE SOUTHERN 1/2 OF THE CWA. AS IS OFTEN
THE CASE IN THESE OVERRUNNING EVENTS THERE IS INITIALLY SOME DRY
AIR IN THE LOW LEVELS...BUT WHAT WILL LIKELY OVERCOME THAT RATHER
QUICKLY IS STRONG FRONTOGENESIS. BOTH THE NAM AND GFS SHOW VERY
STRONG FORCING BY 12Z ACRS SOUTHERN VA...THEN RAPIDLY LIFT THIS OFF
TO THE NORTH FROM 18Z/SUN TO 00Z/MON. THIS OFTEN AIDS THE PRECIP
IN COMING IN FAST...AND THIS IS THE MAIN REASON MECKLENBURG HAS
BEEN ADDED TO THE WATCH (COULD SEE ACCUMULATING ICE HERE PRIOR TO
DAYBREAK SUN). HOWEVER...CONFIDENCE IN RECEIVING 0.25" OF ICE (OR
GREATER) IS NOT HIGH ENOUGH TO TRANSITION TO A WARNING IN THE
SOUTHERN PIEDMONT ZONES SINCE THE PRECIP MAY BECOME RATHER LIGHT
BY LATE MORNING AND BEYOND AS THE -10C TO -20 C RAPIDLY DRIES OUT
AND THE FORCING LIFTS NORTH. CONFIDENCE FOR 0.25" ICE IS HIGHEST
ACRS THE NW ZONES AS THE DRYING IS LESS PRONOUNCED THROUGH THE
AFTN HRS AND THIS IS ALSO WHERE SFC TEMPS WILL STAY THE COLDEST THE
LONGEST...PERHAPS IN THE UPPER 20S IN WESTERN LOUISA/FLUVANNA
THROUGH MOST OF THE DAY. THE MOST DIFFICULT REGION WITH RESPECT TO
ICE ACCUMULATION WILL PROBABLY BE METRO RICHMOND...AND IT IS
LIKELY THAT AN ADVISORY WILL BE NEEDED ALONG A SLIVER OF COUNTIES BORDERING
THE WATCH (AS WELL AS PART OF THE WATCH THAT MAY NOT GET
TRANSITIONED TO A WARNING). THESE AREAS WILL TEND TO HAVE HIGHS
IN THE MID 30S...BUT WILL BE AT OR JUST BELOW 32 F THROUGH MUCH OF
THE AFTN. THE MD ERN SHORE MAY SEE A FEW HRS OF SLEET/SNOW AND
PERHAPS FREEZING RAIN BUT EXPECT THE MARINE LAYER TO QUICKLY CHANGE
P-TYPE TO ALL RAIN NOT MUCH AFTER 18Z. EXPECT TEMPS TO BE WARM
ENOUGH OVER THE VA ERN SHORE...SE VA AND NE NC FOR PCPN TO BE JUST
RAIN FM THE START. HIGHS RANGE FROM AROUND 50 NE NC COAST TO
AROUND 30 F IN LOUISA COUNTY.
WARMER AIR (TEMPS RISING ABV FREEZING) WILL GRADUALLY WORK ITS WAY
NW INTO THE PIEDMONT SUN EVENING...BUT MAY NEVER MAKE IT TO
WESTERN LOUISA/FLUVANNA AND PERHAPS CUMBERLAND/GOOCHLAND. EXTENDED
PORTIONS OF THE WATCH THROUGH 12Z/MON AS NEXT SHORTWAVE PUSHES
INTO THE REGION FROM THE WEST BY 06Z...ENHANCING PRECIP (AND
SHOULD THIS STILL BE FREEZING RAIN THERE WOULD BE ADDITIONAL ICE
ACCUMULATION).
LOWS SUN NGT REMAINING NEARLY STEADY AROUND 30 F NW...TO THE UPPER
40S NC COASTAL AREAS.
STILL MUCH UNCERTAINTY REMAINS WITH THIS SYSTEM...SO ANY
WATCH...WARNING OR ADVISORY HEADLINES FOR COUNTIES COULD CHANGE
DURING THE NEXT 24 HOURS OR SO.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
GFS/NAM DIFFER WRT FRONTAL POSITION MONDAY. NAM IS FURTHER NORTH
WHERE BEST LIFT AND SUPPORT FOR PCPN WILL BE WHILE THE GFS/ECMWF
IS FURTHER SOUTH WITH COPIOUS AMOUNTS OF MOISTURE ACROSS THE REGION.
TSCTNS DO AGREE ON ENOUGH MOISTURE FOR CLOUDY SKIES AND AT LEAST A
GOOD POTENTIAL FOR A FEW HUNDREDTHS OF QPF EVEN IN THE SOUTH.
RAISED POPS TO LIKELY ALL AREAS BUT QPF-WISE THIS TIME PERIOD WILL
FOCUS OVER THE NORTH. THE FRONTAL POSITION ALONG WITH ANY
RESIDUAL ICE ON THE GROUND WILL MAKE FOR A WIDE RANGE IN TEMPS.
KEPT HIGHS IN THE MID 40S IN COUNTIES THAT MAY HAVE SOME MORNING
ICE...RANGING TO AROUND 60 F FAR SOUTHERN AREAS.
ANOTHER WAVE OF LOW PRESSURE PROGGED TO ENHANCE PCPN ALONG THE
FRONT AS IT MOVES SOUTH ACROSS THE FA MONDAY NIGHT. IN ADDITION...
JUST ENOUGH COLD AIR IS PROGGED ACROSS NORTHERN MOST COUNTYS FOR
PCPN TO BECOME MIXED WITH SOME WET SNOW LATE. CHC POPS ALL AREAS
WITH LOWS FROM THE L30S NORTH TO L40S SOUTH.
BOTH GFS/ECMWF CONT TO SHOW A THIRD WAVE OF LOW PRESSURE MOVING NE
ALONG THE BOUNDARY CONTINUING THE PCPN CHCS ACROSS THE AREA TUE.
DESPITE LOWERING THICKNESSES...TEMPS EXPECTED TO BE WARM ENOUGH FOR
RAIN. HIGHS NEAR 40 NORTH TO L50S SOUTH.
HIGH PRESSURE ACROSS THE NATIONS MID SECTION FINALLY PUSHES FRONTAL
BOUNDARY AND ASSOCIATED MOISTURE SOUTH AND EAST OF FA TUESDAY NIGHT.
WILL SHOW DECREASING CLOUDINESS. CAA RESULTS IN TEMPS DROPPING INTO
THE 20S TO L30S SERN COASTAL AREAS.
COLD & DRY FOR THE REST OF THE PERIOD. HIGHS WED & FRI IN THE U30S
TO U40S. THURS TO BE THE COLDEST WITH HIGHS IN THE M30S-L40S. LOWS
20-30...SOME TEENS POSSIBLE IN NORMALLY COLDER SPOTS.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
A COLD FRONT IS PUSHING SOUTH INTO ERN NC ERLY THIS MORNG. WINDS
BEHIND THE FRONT WILL BE GUSTY AT TIMES. PRECIP AND IFR/MVFR CIGS
WILL CONTINUE THRU THE MORNG HRS. CONDITIONS SLOWLY IMPROVE FROM
NORTH TO SOUTH LATER TODAY. THE NRLY WINDS WILL SLOWLY DIMINISH
INTO THE AFTN.
OUTLOOK...NEXT WAVE OF LOW PRESSURE WILL MOVE THROUGH ON SUNDAY WITH
MORE WIDESPREAD IFR CONDITIONS AT ALL SITES. P-TYPE SHOULD BE ALL
RAIN FOR KORF/KECG/KPHF...WITH A GOOD PROBABILITY FOR MIXED WINTER
PRECIP AT KRIC AND KSBY BEFORE A CHANGE TO RAIN. IFR CEILINGS ARE
LIKELY TO PERSIST SUN NIGHT/MON WITH PERIODS OF RAIN AT EACH OF THE
TAF SITES. CONDITIONS IMPROVE TUESDAY WILL VFR/DRY WEATHER BY TUESDAY
NIGHT.
&&
.MARINE...
ALL SCA HEADLINES HAVE BEEN PUT INTO EFFECT WITH THIS FORECAST
PACKAGE AS CONDITIONS ARE ALREADY AT SCA THRESHOLDS OR WILL BE THERE
BY LATER THIS MORNG. COLD FRNT CURRENTLY STRETCHED ALONG THE NC/VA
BORDER WILL SLOWLY SLIDE SOUTH TDY...WITH A STRONG CAA SURGE
FOLLOWING THE FROPA LEADING TO 20-25 KT NLY WINDS OVR THE WTRS
(15-20 KT OVR THE RIVERS). WINDS SLOWLY DIMINISH TNGT AS THE FRNT
PUSHES FARTHER SOUTH OF THE AREA...SO WILL DROP HEADLINES FOR THE
RIVERS AT 06Z THEN THE NRN BAY AT 12Z. STILL THINK WINDS WILL STAY
IN THE 15-20 KT RANGE OVR THE SRN BAY INTO SUN SO WILL END THE
HEADLINE THERE AT THE END OF THE THIRD PERIOD. AS FOR SEAS OVR CSTL
WTRS FOR TDY THRU SUN...EXPECT MAINLY 4-5 FT SEAS AND UP TO 6-7 FT
OVR SRN CSTL WTRS.
WINDS SHIFT TO THE SW AND CONDITIONS IMPROVE MON WITH SEAS AROUND 4
FT. ANOTHER COLD FRNT PUSHES THROUGH THE REGION MON NGT/TUE
MORNG...WITH SCA CONDITIONS AGAIN PSBL.
&&
.TIDES/COASTAL FLOODING...
GIVEN THE ASTRONOMICAL TIMING OF THE EVENT...PREDICTED TIDES AND
LEVELS ARE PROGGED TO REMAIN BLO ANY CRITICAL THRESHOLDS THROUGH THE
WEEKEND.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...WINTER STORM WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING
FOR VAZ048-049-060>064-068-069.
WINTER STORM WATCH FROM LATE TONIGHT THROUGH SUNDAY EVENING
FOR VAZ065>067.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR ANZ632-634-650-
652-654-656-658.
SMALL CRAFT ADVISORY UNTIL 1 AM EST SUNDAY FOR ANZ635>638.
SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR ANZ630-631-633.
&&
$$
SYNOPSIS...LKB
NEAR TERM...LKB/JAB
SHORT TERM...LKB/TMG
LONG TERM...MPR
AVIATION...MAS/LSA
MARINE...MAS
TIDES/COASTAL FLOODING...
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
424 PM EST SAT DEC 7 2013
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS DIGGING FROM NRN
CA INTO NEVADA. AT THE SFC...WRLY WINDS PREVAILED THROUGH THE UPPER
GREAT LAKES TO THE NORTH OF THE ARCTIC RIDGE BUILDING FROM THE NRN
PLAINS AND UPPER MS VALLEY TO THE SRN LAKES. VERY COLD AIR REMAINED
WITH MID AFTERNOON READINGS ONLY CLIMBING INTO THE 5F TO 15F RANGE
THROUGH MID AFTERNOON. VIS SATELLITE INDICATED BACKING WINDS OVER
WRN LAKE SUPERIOR WITH THE LES BANDS BECOMING ALIGNED FROM SW-NE.
TONIGHT...EXPECT LES BANDS INTO THE KEWEENAW TO LIFT SLOWLY
NORTHWARD THIS EVENING. EVEN THOUGH THE HIGHER RES MODELS INDICATED
PERSISTENT LOW LEVEL CONV AND LES FROM AT LEAST CMX
NORTHWARD...CONFIDENCE IS LOWER GIVEN THE SATELLITE TRENDS. SO...THE
ONGOING HEADLINES WERE RETAINED FOR NOW BUT MAY NEED TO BE LIFTED
EARLIER THAN PREVIOUSLY FCST. IF A DOMINANT BAND CAN REDEVELOP AND
BRUSH THE WRN SHORE OF THE KEWEENAW...ADDITIONAL SNOWFALL AMOUNTS OF
3 TO 6 INCHES MAY BE POSSIBLE.
WITH A PERIOD OF FAVORABLE RADIATIONAL COOLING UNTIL LATE TONIGHT...
EXPECT MIN TEMPS NEAR LOWER END OF GUIDANCE WITH LOW TO MID TEENS
BELOW ZERO ACROSS MUCH OF THE WRN INTERIOR RANGING TO AROUND ZERO
OVER THE INTERIOR EAST. WINDS INTO THE 5 T0 10 MPH RANGE TIL LATE
TONIGHT CAUSED WIND CHILL READINGS TO DIP TO NEAR 25 BELOW...SO THE
WIND CHILL ADVISORY WAS RETAINED. THE POTENTIAL FOR INCREASING HIGH
CLOUDS LATE TONIGHT COULD CAUSE TEMPS TO LEVEL OFF A BIT OR RISE
SLIGHTLY TOWARD 12Z SUN.
SUN...ANY REMAINING LES IS EXPECTED TO LIFT TO THE NORTH OF KEWEENAW
AS WINDS BACK IN THE DEVELOPING WAA PATTERN. A BROAD AREA OF
280K-290K ISENTROPIC LIFT WILL BRING LIGHT SNOW FROM MN/WI INTO
UPPER MI DURING THE AFTERNOON. ALTHOUGH...THE VERY DRY LOW LEVELS IN
THE ARCTIC AIRMASS MAY DELAY THE ONSET OF THE PCPN...EXPECT AT LEAST
SOME LIGHT SNOW OVER THE SOUTH IN THE AFTERNOON THAT WILL SPREAD
THROUGH THE REST OF THE CWA BY MID TO LATE AFTERNOON. ACCUMULATIONS
BY 00Z/09 WILL BE RELATIVELY LIGHT...AROUND A HALF INCH OR
LESS...MAINLY OVER THE SOUTH.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 416 PM EST SAT DEC 7 2013
DEEP TROUGHING ORIENTED FROM EASTERN CANADA ACROSS THE GREAT LAKES
AND WEST TO THE SOUTHWEST CONUS IS REINFORCED THROUGHOUT THE UPCOMING
WEEK. COLD AIRMASS MAY FINALLY MAY START TO RELAX BY NEXT WEEKEND AS
FLOW ALOFT BECOMES MORE ZONAL. FLOW PATTERN THIS WEEK REMAINS ACTIVE
ACROSS THE UPPER LAKES. A COUPLE OF SYSTEMS WILL CROSS THE AREA WITH
WIDESPREAD SYSTEM SNOWS. MOST SIGNIFICANT OF THESE WILL OCCUR SUNDAY
NIGHT AS SHORTWAVE/PV ANAMOLY CROSSING NEVADA/UTAH THIS AFTN/EVENING
HEADS OUT INTO CNTRL PLAINS SUNDAY AFTN THEN LIFTS ACROSS UPPER
GREAT LAKES SUNDAY NIGHT. SLIGHT WARM AIR ADVECTION...RELATIVE
TERM IN THIS AIRMASS...OCCURS OVER SOUTH CENTRAL AND EASTERN CWA
SUNDAY EVENING WITH PVA/DEEP LAYER FORCING THROUGH REST OF NIGHT.
CROSS-SECTIONS INDICATE VERY SHALLOW FGEN FORCING BLO H9...MAINLY
SOUTH AND EAST. MINIMAL SLANTWISE INSTABILITY/NEGATIVE EPV TO RESULT
IN HEAVIER BANDED SNOW THOUGH. ENHANCEMENT TO SYSTEM SNOW MAY OCCUR
NEAR BAY OF GREEN BAY AND LK MICHIGAN WITH ESE/E WINDS IN LOW-LEVELS
WITH TEMPS AT INVERSION TOP OF H85 AROUND -10C /LK MICHIGAN WATER
TEMPS ARE AROUND +5C/. TRICK IS HOW LONG FAVORABLE WIND DIRECTION
PERSISTS AND WHETHER THERE IS TOO MUCH SHEAR IN LAKE CONVECTIVE
LAYER TO OFFSET THIS. EXPECT GENERAL 2-4" OF SYNOPTIC SNOW WITH
MIXING RATIOS 1-2G/KG AND WITH 0.15-0.20 AVERAGED MODEL QPF USING
SLR/S 17-19:1. BASED ON SOUNDINGS...HIGHER SLR/S SEEMED TOUGHER TO
ACHIEVE AS BULK OF LIFT WILL BE OCCURRING AT TEMPS LESS THAN -20C.
SLR/S WILL PROBABLY BE EVEN LOWER HEADING FARTHER NORTH INTO UPR
MICHIGAN...SO SNOW AMOUNTS OF AN INCH MAYBE TWO ARE EXPECTED CLOSER
TO LK SUPERIOR SHORE. ISSUED WINTER WEATHER ADVY FOR THE SYSTEM
SNOW. BASED ON SREF PLUMES AND FCST POPS...VALID TIME OF ADVY FAR
SCNTRL WILL START LATE SUNDAY AFTN AND GO THROUGH DAYBREAK ON
MONDAY. ADVY FOR ZONES TO THE EAST WILL START AND END A FEW HOURS
LATER.
LOW PRESSURE SYSTEM LIFTS TO NORTHEAST OF LK SUPERIOR BY 18Z ON
MONDAY AND THIS WILL USHER IN ANOTHER RETURN TO THE COLD AND WINDY
WEATHER THAT OCCURRED LATE THIS LAST WEEK INTO TODAY. AND YES...LAKE
EFFECT SNOWS...HEAVY AT TIMES...WILL RAMP UP AGAIN IN THE AREAS
FAVORED BY WNW-W FLOW. SO...ONCE AGAIN...KEWEEENAW PENINSULA WILL BE
IN LINE FOR HEAVY LK EFFECT SNOWS. SOUNDINGS IN WAKE OF THE LOW
PRESSURE INDICATE MOIST/UNSTABLE PROFILE TO H7 WITH SHARP CONVERGENCE
DEVELOPING ACROSS KEWEENAW BY MID MORNING MONDAY AND CONTINUING
THROUGH AT LEAST LATE EVENING ON MONDAY NIGHT. SIMILAR TO
THURSDAY...IF WESTERLY FLOW CAN PERSIST IN ONE AREA...LEADING TO
STRONG CONVERGENCE...FOOT PLUS AMOUNTS WILL BE POSSIBLE ACROSS CNTRL
HOUGHTON COUNTY... AFFECTING PAINESDALE...ATLANTIC MINE...HOUGHTON
AND HANCOCK AND POSSIBLY AS FAR NORTH AS CALUMET AND MOHAWK. LAKE
EFFECT HEADLINES ARE RUNNING THEIR COURSE CURRENTLY...SO DID NOT
WANT TO PUT UP ANOTHER LK EFFECT SNOW WATCH AT THIS TIME. WILL LET
MID SHIFT ASSESS THIS POTENTIAL. MAIN ISSUE AWAY FM THE INCREASING
LK EFFECT BY MONDAY AFTN WILL BE ANOTHER BLAST OF COLD TEMPS AND
LOWERING WIND CHILL READINGS.
DOES APPEAR THAT AS STRONGER SHORTWAVE/PRETTY DECENT AREA OF H7-H5
Q-VECTOR CONVERGENCE ARRIVES LATER MONDAY NIGHT...BLYR WINDS BACK SW
ENOUGH TO DISRUPT HEAVIER SNOW ON THE KEWEENAW. THIS MAY PROVIDE A
GOOD BREAK POINT FOR WHATEVER HEADLINE IS ISSUED FOR MONDAY AND
MONDAY EVENING...THOUGH THERE IS A CHANCE THE HEAVIER SNOW BANDS
WILL JUST MAKE INTO KEWEENAW COUNTY BEFORE STALLING OUT. TOUGH TO
SAY AT THIS POINT. SOUNDINGS ELSEHWERE INDICATE ENOUGH MOISTENING
AND LIFT TO INCREASE POPS FOR THE SYSTEM...ESPECIALLY NORTH HALF.
SNOW AMOUNTS FM THE SYSTEM WILL BE ON THE LGT SIDE...LESS THAN AN
INCH MAINLY. OTHER IMPACT FM THE SHORTWAVE WILL BE FOR TEMPS TO TRY
TO RISE SOME LATER MONDAY NIGHT AS THE WINDS INCREASE. THIS MAKES
FOR TRICKY WIND CHILL FORECAST. CURRENT FCST FOR WINDS AND TEMPS
DOES SUGGEST THAT WESTERN HALF OF CWA MAY SEE WIND CHILL CRITERIA
BE MET AT TIMES ON MONDAY NIGHT INTO TUESDAY MORNING. LAST IMPACT
FROM THE SYSTEM WILL BE TO PUSH STRONGER SFC TROUGH SOUTH ACROSS LK
SUPERIOR RESULTING IN MORE OF A NW WIND IN BLYR FOR TUESDAY/TUESDAY
NIGHT. USED LK EFFECT CLIMATOLOGY POPS TO BRING HIGHER POPS TO AREAS
FAVORED BY WNW FLOW SUCH AS ONTONAGON COUTNY AND ALSO IN THE EASTERN
CWA...MAINLY EAST OF MUNISING AND TO THE NORTH OF NEWBERRY.
IN WAKE OF THE TROUGH PASSAGE...COLDEST AIR OF WEEK POURS ACROSS
WITH H85 TEMPS DOWN TO AROUND -25C TUESDAY NIGHT INTO WEDNESDAY.
MAY HAVE MORE WIND CHILL ISSUES TUESDAY NIGHT INTO WEDNESDAY AS
INLAND TEMPS FALL BLO ZERO AND WINDS STAY UP BEHIND THE TROUGH.
COLDEST DAY OF THE WEEK FOR WEDNESDAY WITH MAX TEMPS OVER INLAND
WEST POSSIBLY STAYING AT OR BLO ZERO THE ENTIRE DAY. COLDEST NIGHT
OF THE WEEK LIKELY ON WEDNESDAY NIGHT. AS WINDS GO CALM MAY SEE MINS
LESS THAN 20 BLO ZERO.
SLIGHT WARMING TREND FOR LATE THIS WEEK...BUT STILL QUITE A BIT BLO
NORMAL FOR DAYTIME HIGHS. WEST/SOUTHWEST FLOW LK EFFECT STAYS IN
PLACE ON KEWEENAW THURSDAY BUT THEN SHOULD REORIENT TO MORE NNW-N
FLOW AREAS ON FRIDAY AS ANOTHER SFC TROUGH SWINGS ACROSS. MAY SEE
SOME SYSTEM SNOW THURSDAY NIGHT INTO FRIDAY AHEAD OF THAT TROUGH BUT
THERE ARE SOME TIMING ISSUES THERE STILL...SO WILL JUST HAVE LOW
CHANCE POPS FOR NOW. DID BUMP UP THE CONSENSUS POPS FOR THE LK
EFFECT AREAS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1252 PM EST SAT DEC 7 2013
AT CMX...LAKE EFFECT SNOW WILL CONTINUE AT CMX THROUGH LATE
TONIGHT. SNOWFALL ALONG WITH BLOWING SNOW WILL LIKELY CAUSE
VISIBILITY TO REMAIN AT LIFR/VLIFR CONDITIONS. CEILINGS SHOULD
REMAIN AT OR AROUND 1500FT THROUGH THIS TAF PERIOD. WINDS WILL
REMAIN OUT OF THE WEST NORTHWEST. WITH WINDS BACKING TO THE SW LATE
TONIGHT...EXPECT IMPROVMENT TO VFR CONDITIONS BY SUN MORNING.
AT SAW AND IWD...SW TO W WINDS WILL FAVOR VFR CONDITIONS IN THE DRY
ARCTIC AIRMASS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 416 PM EST SAT DEC 7 2013
EXPECT BRIEF BREAK IN STRONGER WINDS OVER LK SUPERIOR LATER THIS
EVENING THROUGH SUNDAY AS PRESSURE GRADIENT WEAKENS. A LOW PRESSURE
SYSTEM MOVING ACROSS THE AREA ON SUNDAY NIGHT...BUT WINDS WILL REMAIN
LESS THAN 25 KTS. AS THE LOW MOVES OUT OF THE AREA ON MONDAY...EXPECT
THE GRADIENT TO TIGHTEN AND WEST GALES TO DEVELOP THROUGH MONDAY
NIGHT. ANOTHER LOW PRESSURE SYSTEM WILL PASS THROUGH THE UPPER GREAT
LAKES TUESDAY INTO WEDNESDAY...POSSIBLY LEADING TO MORE GALES FROM
THE WEST TO NORTHWEST TUESDAY AFTERNOON THROUGH WEDNESDAY EVENING.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 1 AM EST SUNDAY FOR MIZ003.
WINTER WEATHER ADVISORY FROM 4 PM EST /3 PM CST/ SUNDAY TO 7 AM
EST /6 AM CST/ MONDAY FOR MIZ012-013.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST SUNDAY FOR MIZ001.
WIND CHILL ADVISORY UNTIL 7 AM EST /6 AM CST/ SUNDAY FOR MIZ002-
004-009>011-084.
WINTER WEATHER ADVISORY FROM 7 PM SUNDAY TO 9 AM EST MONDAY FOR
MIZ007-014-085.
LAKE SUPERIOR...
GALE WATCH FROM MONDAY MORNING THROUGH LATE MONDAY NIGHT FOR
LSZ264>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 PM EST /6 PM CST/ THIS
EVENING FOR LSZ162-263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...JLB
MARINE...JLA
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1228 PM EST SAT DEC 7 2013
.AVIATION...
//DISCUSSION...
VFR CONDITIONS EXPECTED THROUGH THE TAF CYCLE AS DRY ARCTIC AIRMASS
DRIFTS ACROSS THE REGION. MBS/FNT HAVE A CHANCE OF MVFR CIGS FOR THE
NEXT HOUR OR TWO AS CURRENT SATELLITE TRENDS SHOW THE LAKE EFFECT
CLOUDS STILL HOLDING ON...BUT SCATTERING OUT. SKIES WILL CLEAR
TONIGHT BUT WILL GRADUALLY FILL BACK IN ON SUNDAY AS THE NEXT SYSTEM
APPROACHES. NON VFR CONDITIONS AND POTENTIAL PRECIP LOOK TO HOLD OFF
TIL AFTER THIS TAF CYCLE. CURRENTLY THERE ARE A FEW GUSTS AROUND 15
KNOTS BUT VERY SPORADIC/ISOLATED AND WILL LEAVE OUT OF THE TAFS.
//DTW THRESHOLD THREATS...
* NONE.
&&
.PREV DISCUSSION...ISSUED 406 AM EST SAT DEC 7 2013
SHORT TERM...TODAY AND TONIGHT
LOCALIZED SURFACE RIDGING THAT HAS BEEN SUSTAINED BY LOW LEVEL COLD
AIR ADVECTION WILL GIVE WAY TONIGHT TO THE CENTER OF A +1035 MB
SURFACE ANTICYCLONE. STRONG SUBSIDENCE SIGNAL IN THE MODEL SOUNDINGS
AS WELL AS MIDLEVEL OMEGA PLAN VIEWS SUGGESTS NO DEGREE OF DYNAMIC
FORCING SUPPORTIVE FOR PRECIPITATION. WHILE MODELS ARE HAVING A
DIFFICULT TIME WITH MOISTURE PROFILES AS IS ALWAYS THE
CASE...SATELLITE TRENDS ON LAKE EFFECT STRATOCUMULUS SUPPORTS A
BUILDING SCT-OVC CLOUD DECK EARLY THIS MORNING. THIS CLOUD DECK MAY
VERY WELL ESTABLISH ITSELF PRIOR TO THE COMMENCEMENT OF DIURNAL
MIXING PROCESSES. THEN THE QUESTION IS WHAT SORT OF PERSISTENCE THE
SC DECK COULD HOLD DESPITE LESS THAN IMPRESSIVE MODEL SOUNDINGS AND
BACKGROUND AMOUNT OF MOISTURE. THE RAP IS A NEW AND SUPPORTIVE
OUTLIER SUGGESTING THAT A GOOD AMOUNT OF SATURATION/CLOUD WILL EXIST
UNDER THE INVERSION BASE AT 3.5 KFT AGL. WILL TAKE THE PESSIMISTIC
CLOUD ROUTE HERE FOR A MEANINGFUL CHUNK OF TODAY. THE FORECAST WILL
READ MOSTLY CLOUDY TRANSITIONING TO PARTLY CLOUDY. TEMPERATURES
TODAY WILL ONLY REACH THE LOWER TO MIDDLE 20S...ROUGHLY 13 TO 15
DEGREES BELOW AVERAGE.
THE FORECAST QUESTION FOR TONIGHT IS WHAT LOWS WILL DROP TO. IT
APPEARS THE STAGE WILL BE SET FOR FAVORABLE RADIATIVE COOLING WITH
THE ONLY MISSING CONDITION...A FRESH SNOWPACK. DON`T HAVE A GOOD
CALIBRATED FEEL YET. SIDED WITH A MIX OF MOS...WHICH GIVES LOW TEENS
OUTSIDE OF THE HEAT ISLAND...WITH MID TEENS IN DETROIT METRO.
LONG TERM...SUNDAY THROUGH FRIDAY
HIGH AMPLITUDE MID LEVEL TROUGHING CURRENTLY CENTERED FROM NORTH
CENTRAL CANADA INTO THE MID SECTION OF THE COUNTRY WILL REMAIN THE
PREDOMINANT LARGE SCALE FEATURE WELL INTO NEXT WEEK AS THE MAIN
HEIGHT FALL CENTER SLOWLY SHIFTS EASTWARD WITH TIME. THIS WILL
PRESENT A SUSTAINABLE CONDUIT FOR MULTIPLE REINFORCING ROUNDS OF
ARCTIC AIR TO INFILTRATE SE MICHIGAN RIGHT THROUGH THE UPCOMING
WORK WEEK. LEAD PUSH OF MODIFIED ARCTIC FIRMLY IN RESIDENCE LOCALLY
TO START SUNDAY LODGED WITHIN A 1035MB LOW LEVEL ANTICYCLONE SLOWLY
SHIFTING THROUGH THE REGION. SUPPRESSED MIXING POTENTIAL WITHIN A
STABLE LOW LEVEL EASTERLY FLOW WILL ENSURE HIGHS AGAIN HOLD IN THE
20S.
ATTENTION FOR THE SUNDAY NIGHT PERIOD REMAINS CENTERED ON THE
DOWNSTREAM EVOLUTION OF THE LEAD SHORTWAVE CURRENTLY ANCHORING THE
BASE OF THE MEAN TROUGH. STRONG HEIGHT FALLS BARRELING SOUTHWARD
OUT OF CENTRAL CANADA THIS WEEKEND WILL SQUEEZE THIS WAVE
NORTHEASTWARD...THE VORTICITY CENTER SHEARING FROM NORTHERN IL/
SOUTHERN WI THROUGH NORTHERN LOWER MI BY SUNDAY NIGHT. ASSESSMENT
OF LATEST 300-200MB POTENTIAL VORTICITY FIELDS SUGGEST ENOUGH
SEPARATION WILL EXIST BETWEEN THESE HEIGHT FALL CORES TO LEAVE THE
LEAD WAVE IN A MORE WEAKENED/LESS PHASED STATE AS THE ATTENDANT
SURFACE WAVE SHIFTS THROUGH THE LOWER PENINSULA. WHILE THE BETTER
MOISTURE ADVECTION WITHIN THE PREVAILING SOUTHWESTERLIES WILL GET
PINCHED OFF TO THE SOUTH/EAST...SOLID DEPTH AND MAGNITUDE TO THE
INBOUND MOIST LAYER (2-4 G/KG OF SPECIFIC HUMIDITY WITHIN THE
850-925 MB LAYER) WILL EXIST AT THE INTERFACE OF THE NORTHWARD
ARCING ELEVATED WARM FRONTAL BOUNDARY. THERE MAY ALSO BE SOME LAKE
MOISTURE CONTRIBUTION GIVEN EASTERLY BOUNDARY LAYER FLOW. GIVEN
THE PROJECTED TRAJECTORY OF THIS SYSTEM...STRONGEST FORCING DOES
REMAIN CENTERED TO THE NORTHWEST...ALTHOUGH THE TRI-CITIES WILL BE
ON THE FRINGE ON THE MAIN AREA OF DCVA AND BETTER CONVERGENCE.
WITH THAT SAID...CERTAINLY ENOUGH BACKGROUND ASCENT WORKING INTO
A SUFFICIENTLY MOIST ENVIRONMENT TO BRING A WIDESPREAD AREA OF
LIGHT SNOW THROUGH SOUTHEAST MICHIGAN SUNDAY NIGHT. THE
COMBINATION OF THE ADDED DEGREE OF FORCING AND LIKELIHOOD OF
SLIGHTLY LONGER RESIDENCE TIME WILL FOCUS THE GREATER ACCUMULATION
POTENTIAL INTO THE TRI-CITIES...WHERE SOME AMOUNTS IN EXCESS OF AN
INCH STILL SEEM PLAUSIBLE. ELSEWHERE AN INCH OR LESS WITH SOME
REDUCTION IN SNOW RATIOS EXPECTED WITH THE LOW LEVEL PROFILE
WARMING WITH TIME.
COLD AIR ADVECTION QUICKLY ENSUES ON THE HEELS OF THIS SYSTEM
THROUGHOUT MONDAY. SHORT LIVED DRY SLOT FOR THE MORNING PERIOD
BEFORE A LAKE ENHANCED MOISTURE PLUME EXPANDS EASTWARD WITHIN THE
BACKGROUND OF COLD/CYCLONIC FLOW. THIS WILL SUPPORT AN EXTENSIVE
STRATUS DECK FOR MUCH OF THE DAY...AND ALLOW FOR SOME LIGHT SNOW
SHOWER/FLURRY PRODUCTION. THE MAIN ARCTIC BLAST WILL ACCOMPANY A
CLIPPER CRUISING THROUGH THE NORTHERN GREAT LAKES ON TUESDAY. A
TRAILING WAVE MAY REINFORCE THIS AIRMASS INTO WEDNESDAY...THE NET
RESULT BEING A STRETCH OF TEMPERATURES A GOOD 15 TO 20 DEGREES
BELOW NORMAL FOR THE 2ND WEEK IN DECEMBER. A SOLID GRADIENT
ATTENDANT TO THESE NORTHERN STREAM WAVES WILL PROVIDE THE
ADDITIVE WIND ELEMENT...RESULTING IN DAYTIME WIND CHILL READINGS
OF SINGLE DIGITS TUESDAY AND WEDNESDAY.
MARINE...
A STRONGER WESTERLY WIND WILL REMAIN IN PLACE TODAY ACROSS NORTHERN
LAKE HURON AS ARCTIC AIR CONTINUES TO FUNNEL ACROSS THE WATERS.
WINDS WILL DECREASE TONIGHT AND SUNDAY AS STRONG HIGH PRESSURE MOVES
THROUGH THE REGION. SOUTHEAST WINDS WILL STRENGTHEN AGAIN SUNDAY
NIGHT AS LOW PRESSURE TRACKS THROUGH LOWER MICHIGAN. WINDS WILL
SHIFT TO SOUTHWESTERLY IN THE WAKE OF THIS SYSTEM ON MONDAY.
INCREASING INSTABILITY AS ARCTIC AIR SPILLS BACK INTO THE REGION
WILL INTRODUCE THE POSSIBILITY FOR GALES MONDAY INTO MONDAY NIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....DRK
SHORT TERM...CB
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
631 AM EST SAT DEC 7 2013
.AVIATION...
//DISCUSSION...
UNSTABLE REGIME OVER THE GREAT LAKES HAS BEEN ALLOWING FOR
STRATOCUMULUS PERSISTENCE OVER THE GREAT LAKES WITH MANY LOCATIONS
THIS MORNING UNDER A HEALTHY STRATOCU DECK. LATEST RAP MOISTURE
PROFILES SUPPORTS TRAPPING SATURATION AND MOISTURE UNDER ACTIVE
850-500MB SUBSIDENCE. WITH A BUILDING SURFACE ANTICYCLONE AND A LOW
BACKGROUND RH SIGNAL...SUSPECT CLOUDS WILL LESSEN SIGNIFICANTLY BY
THE AFTERNOON HOURS. CONDITIONS TONIGHT WILL REMAIN BENIGN AHEAD OF
INCREASING MIDLEVEL MOISTURE TOMORROW.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN DURATION OF CEILINGS BELOW 5000 FEET TODAY.
&&
.PREV DISCUSSION...ISSUED 406 AM EST SAT DEC 7 2013
SHORT TERM...TODAY AND TONIGHT
LOCALIZED SURFACE RIDGING THAT HAS BEEN SUSTAINED BY LOW LEVEL COLD
AIR ADVECTION WILL GIVE WAY TONIGHT TO THE CENTER OF A +1035 MB
SURFACE ANTICYCLONE. STRONG SUBSIDENCE SIGNAL IN THE MODEL SOUNDINGS
AS WELL AS MIDLEVEL OMEGA PLAN VIEWS SUGGESTS NO DEGREE OF DYNAMIC
FORCING SUPPORTIVE FOR PRECIPITATION. WHILE MODELS ARE HAVING A
DIFFICULT TIME WITH MOISTURE PROFILES AS IS ALWAYS THE
CASE...SATELLITE TRENDS ON LAKE EFFECT STRATOCUMULUS SUPPORTS A
BUILDING SCT-OVC CLOUD DECK EARLY THIS MORNING. THIS CLOUD DECK MAY
VERY WELL ESTABLISH ITSELF PRIOR TO THE COMMENCEMENT OF DIURNAL
MIXING PROCESSES. THEN THE QUESTION IS WHAT SORT OF PERSISTENCE THE
SC DECK COULD HOLD DESPITE LESS THAN IMPRESSIVE MODEL SOUNDINGS AND
BACKGROUND AMOUNT OF MOISTURE. THE RAP IS A NEW AND SUPPORTIVE
OUTLIER SUGGESTING THAT A GOOD AMOUNT OF SATURATION/CLOUD WILL EXIST
UNDER THE INVERSION BASE AT 3.5 KFT AGL. WILL TAKE THE PESSIMISTIC
CLOUD ROUTE HERE FOR A MEANINGFUL CHUNK OF TODAY. THE FORECAST WILL
READ MOSTLY CLOUDY TRANSITIONING TO PARTLY CLOUDY. TEMPERATURES
TODAY WILL ONLY REACH THE LOWER TO MIDDLE 20S...ROUGHLY 13 TO 15
DEGREES BELOW AVERAGE.
THE FORECAST QUESTION FOR TONIGHT IS WHAT LOWS WILL DROP TO. IT
APPEARS THE STAGE WILL BE SET FOR FAVORABLE RADIATIVE COOLING WITH
THE ONLY MISSING CONDITION...A FRESH SNOWPACK. DON`T HAVE A GOOD
CALIBRATED FEEL YET. SIDED WITH A MIX OF MOS...WHICH GIVES LOW TEENS
OUTSIDE OF THE HEAT ISLAND...WITH MID TEENS IN DETROIT METRO.
LONG TERM...SUNDAY THROUGH FRIDAY
HIGH AMPLITUDE MID LEVEL TROUGHING CURRENTLY CENTERED FROM NORTH
CENTRAL CANADA INTO THE MID SECTION OF THE COUNTRY WILL REMAIN THE
PREDOMINANT LARGE SCALE FEATURE WELL INTO NEXT WEEK AS THE MAIN
HEIGHT FALL CENTER SLOWLY SHIFTS EASTWARD WITH TIME. THIS WILL
PRESENT A SUSTAINABLE CONDUIT FOR MULTIPLE REINFORCING ROUNDS OF
ARCTIC AIR TO INFILTRATE SE MICHIGAN RIGHT THROUGH THE UPCOMING
WORK WEEK. LEAD PUSH OF MODIFIED ARCTIC FIRMLY IN RESIDENCE LOCALLY
TO START SUNDAY LODGED WITHIN A 1035MB LOW LEVEL ANTICYCLONE SLOWLY
SHIFTING THROUGH THE REGION. SUPPRESSED MIXING POTENTIAL WITHIN A
STABLE LOW LEVEL EASTERLY FLOW WILL ENSURE HIGHS AGAIN HOLD IN THE
20S.
ATTENTION FOR THE SUNDAY NIGHT PERIOD REMAINS CENTERED ON THE
DOWNSTREAM EVOLUTION OF THE LEAD SHORTWAVE CURRENTLY ANCHORING THE
BASE OF THE MEAN TROUGH. STRONG HEIGHT FALLS BARRELING SOUTHWARD
OUT OF CENTRAL CANADA THIS WEEKEND WILL SQUEEZE THIS WAVE
NORTHEASTWARD...THE VORTICITY CENTER SHEARING FROM NORTHERN IL/
SOUTHERN WI THROUGH NORTHERN LOWER MI BY SUNDAY NIGHT. ASSESSMENT
OF LATEST 300-200MB POTENTIAL VORTICITY FIELDS SUGGEST ENOUGH
SEPARATION WILL EXIST BETWEEN THESE HEIGHT FALL CORES TO LEAVE THE
LEAD WAVE IN A MORE WEAKENED/LESS PHASED STATE AS THE ATTENDANT
SURFACE WAVE SHIFTS THROUGH THE LOWER PENINSULA. WHILE THE BETTER
MOISTURE ADVECTION WITHIN THE PREVAILING SOUTHWESTERLIES WILL GET
PINCHED OFF TO THE SOUTH/EAST...SOLID DEPTH AND MAGNITUDE TO THE
INBOUND MOIST LAYER (2-4 G/KG OF SPECIFIC HUMIDITY WITHIN THE
850-925 MB LAYER) WILL EXIST AT THE INTERFACE OF THE NORTHWARD
ARCING ELEVATED WARM FRONTAL BOUNDARY. THERE MAY ALSO BE SOME LAKE
MOISTURE CONTRIBUTION GIVEN EASTERLY BOUNDARY LAYER FLOW. GIVEN
THE PROJECTED TRAJECTORY OF THIS SYSTEM...STRONGEST FORCING DOES
REMAIN CENTERED TO THE NORTHWEST...ALTHOUGH THE TRI-CITIES WILL BE
ON THE FRINGE ON THE MAIN AREA OF DCVA AND BETTER CONVERGENCE.
WITH THAT SAID...CERTAINLY ENOUGH BACKGROUND ASCENT WORKING INTO
A SUFFICIENTLY MOIST ENVIRONMENT TO BRING A WIDESPREAD AREA OF
LIGHT SNOW THROUGH SOUTHEAST MICHIGAN SUNDAY NIGHT. THE
COMBINATION OF THE ADDED DEGREE OF FORCING AND LIKELIHOOD OF
SLIGHTLY LONGER RESIDENCE TIME WILL FOCUS THE GREATER ACCUMULATION
POTENTIAL INTO THE TRI-CITIES...WHERE SOME AMOUNTS IN EXCESS OF AN
INCH STILL SEEM PLAUSIBLE. ELSEWHERE AN INCH OR LESS WITH SOME
REDUCTION IN SNOW RATIOS EXPECTED WITH THE LOW LEVEL PROFILE
WARMING WITH TIME.
COLD AIR ADVECTION QUICKLY ENSUES ON THE HEELS OF THIS SYSTEM
THROUGHOUT MONDAY. SHORT LIVED DRY SLOT FOR THE MORNING PERIOD
BEFORE A LAKE ENHANCED MOISTURE PLUME EXPANDS EASTWARD WITHIN THE
BACKGROUND OF COLD/CYCLONIC FLOW. THIS WILL SUPPORT AN EXTENSIVE
STRATUS DECK FOR MUCH OF THE DAY...AND ALLOW FOR SOME LIGHT SNOW
SHOWER/FLURRY PRODUCTION. THE MAIN ARCTIC BLAST WILL ACCOMPANY A
CLIPPER CRUISING THROUGH THE NORTHERN GREAT LAKES ON TUESDAY. A
TRAILING WAVE MAY REINFORCE THIS AIRMASS INTO WEDNESDAY...THE NET
RESULT BEING A STRETCH OF TEMPERATURES A GOOD 15 TO 20 DEGREES
BELOW NORMAL FOR THE 2ND WEEK IN DECEMBER. A SOLID GRADIENT
ATTENDANT TO THESE NORTHERN STREAM WAVES WILL PROVIDE THE
ADDITIVE WIND ELEMENT...RESULTING IN DAYTIME WIND CHILL READINGS
OF SINGLE DIGITS TUESDAY AND WEDNESDAY.
MARINE...
A STRONGER WESTERLY WIND WILL REMAIN IN PLACE TODAY ACROSS NORTHERN
LAKE HURON AS ARCTIC AIR CONTINUES TO FUNNEL ACROSS THE WATERS.
WINDS WILL DECREASE TONIGHT AND SUNDAY AS STRONG HIGH PRESSURE MOVES
THROUGH THE REGION. SOUTHEAST WINDS WILL STRENGTHEN AGAIN SUNDAY
NIGHT AS LOW PRESSURE TRACKS THROUGH LOWER MICHIGAN. WINDS WILL
SHIFT TO SOUTHWESTERLY IN THE WAKE OF THIS SYSTEM ON MONDAY.
INCREASING INSTABILITY AS ARCTIC AIR SPILLS BACK INTO THE REGION
WILL INTRODUCE THE POSSIBILITY FOR GALES MONDAY INTO MONDAY NIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....CB
SHORT TERM...CB
LONG TERM....MR
MARINE.......MR
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS
ONLINE AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
406 AM EST SAT DEC 7 2013
.SHORT TERM...TODAY AND TONIGHT
LOCALIZED SURFACE RIDGING THAT HAS BEEN SUSTAINED BY LOW LEVEL COLD
AIR ADVECTION WILL GIVE WAY TONIGHT TO THE CENTER OF A +1035 MB
SURFACE ANTICYCLONE. STRONG SUBSIDENCE SIGNAL IN THE MODEL SOUNDINGS
AS WELL AS MIDLEVEL OMEGA PLAN VIEWS SUGGESTS NO DEGREE OF DYNAMIC
FORCING SUPPORTIVE FOR PRECIPITATION. WHILE MODELS ARE HAVING A
DIFFICULT TIME WITH MOISTURE PROFILES AS IS ALWAYS THE
CASE...SATELLITE TRENDS ON LAKE EFFECT STRATOCUMULUS SUPPORTS A
BUILDING SCT-OVC CLOUD DECK EARLY THIS MORNING. THIS CLOUD DECK MAY
VERY WELL ESTABLISH ITSELF PRIOR TO THE COMMENCEMENT OF DIURNAL
MIXING PROCESSES. THEN THE QUESTION IS WHAT SORT OF PERSISTENCE THE
SC DECK COULD HOLD DESPITE LESS THAN IMPRESSIVE MODEL SOUNDINGS AND
BACKGROUND AMOUNT OF MOISTURE. THE RAP IS A NEW AND SUPPORTIVE
OUTLIER SUGGESTING THAT A GOOD AMOUNT OF SATURATION/CLOUD WILL EXIST
UNDER THE INVERSION BASE AT 3.5 KFT AGL. WILL TAKE THE PESSIMISTIC
CLOUD ROUTE HERE FOR A MEANINGFUL CHUNK OF TODAY. THE FORECAST WILL
READ MOSTLY CLOUDY TRANSITIONING TO PARTLY CLOUDY. TEMPERATURES
TODAY WILL ONLY REACH THE LOWER TO MIDDLE 20S...ROUGHLY 13 TO 15
DEGREES BELOW AVERAGE.
THE FORECAST QUESTION FOR TONIGHT IS WHAT LOWS WILL DROP TO. IT
APPEARS THE STAGE WILL BE SET FOR FAVORABLE RADIATIVE COOLING WITH
THE ONLY MISSING CONDITION...A FRESH SNOWPACK. DON`T HAVE A GOOD
CALIBRATED FEEL YET. SIDED WITH A MIX OF MOS...WHICH GIVES LOW TEENS
OUTSIDE OF THE HEAT ISLAND...WITH MID TEENS IN DETROIT METRO.
&&
.LONG TERM...SUNDAY THROUGH FRIDAY
HIGH AMPLITUDE MID LEVEL TROUGHING CURRENTLY CENTERED FROM NORTH
CENTRAL CANADA INTO THE MID SECTION OF THE COUNTRY WILL REMAIN THE
PREDOMINANT LARGE SCALE FEATURE WELL INTO NEXT WEEK AS THE MAIN
HEIGHT FALL CENTER SLOWLY SHIFTS EASTWARD WITH TIME. THIS WILL
PRESENT A SUSTAINABLE CONDUIT FOR MULTIPLE REINFORCING ROUNDS OF
ARCTIC AIR TO INFILTRATE SE MICHIGAN RIGHT THROUGH THE UPCOMING
WORK WEEK. LEAD PUSH OF MODIFIED ARCTIC FIRMLY IN RESIDENCE LOCALLY
TO START SUNDAY LODGED WITHIN A 1035MB LOW LEVEL ANTICYCLONE SLOWLY
SHIFTING THROUGH THE REGION. SUPPRESSED MIXING POTENTIAL WITHIN A
STABLE LOW LEVEL EASTERLY FLOW WILL ENSURE HIGHS AGAIN HOLD IN THE
20S.
ATTENTION FOR THE SUNDAY NIGHT PERIOD REMAINS CENTERED ON THE
DOWNSTREAM EVOLUTION OF THE LEAD SHORTWAVE CURRENTLY ANCHORING THE
BASE OF THE MEAN TROUGH. STRONG HEIGHT FALLS BARRELING SOUTHWARD
OUT OF CENTRAL CANADA THIS WEEKEND WILL SQUEEZE THIS WAVE
NORTHEASTWARD...THE VORTICITY CENTER SHEARING FROM NORTHERN IL/
SOUTHERN WI THROUGH NORTHERN LOWER MI BY SUNDAY NIGHT. ASSESSMENT
OF LATEST 300-200MB POTENTIAL VORTICITY FIELDS SUGGEST ENOUGH
SEPARATION WILL EXIST BETWEEN THESE HEIGHT FALL CORES TO LEAVE THE
LEAD WAVE IN A MORE WEAKENED/LESS PHASED STATE AS THE ATTENDANT
SURFACE WAVE SHIFTS THROUGH THE LOWER PENINSULA. WHILE THE BETTER
MOISTURE ADVECTION WITHIN THE PREVAILING SOUTHWESTERLIES WILL GET
PINCHED OFF TO THE SOUTH/EAST...SOLID DEPTH AND MAGNITUDE TO THE
INBOUND MOIST LAYER (2-4 G/KG OF SPECIFIC HUMIDITY WITHIN THE
850-925 MB LAYER) WILL EXIST AT THE INTERFACE OF THE NORTHWARD
ARCING ELEVATED WARM FRONTAL BOUNDARY. THERE MAY ALSO BE SOME LAKE
MOISTURE CONTRIBUTION GIVEN EASTERLY BOUNDARY LAYER FLOW. GIVEN
THE PROJECTED TRAJECTORY OF THIS SYSTEM...STRONGEST FORCING DOES
REMAIN CENTERED TO THE NORTHWEST...ALTHOUGH THE TRI-CITIES WILL BE
ON THE FRINGE ON THE MAIN AREA OF DCVA AND BETTER CONVERGENCE.
WITH THAT SAID...CERTAINLY ENOUGH BACKGROUND ASCENT WORKING INTO
A SUFFICIENTLY MOIST ENVIRONMENT TO BRING A WIDESPREAD AREA OF
LIGHT SNOW THROUGH SOUTHEAST MICHIGAN SUNDAY NIGHT. THE
COMBINATION OF THE ADDED DEGREE OF FORCING AND LIKELIHOOD OF
SLIGHTLY LONGER RESIDENCE TIME WILL FOCUS THE GREATER ACCUMULATION
POTENTIAL INTO THE TRI-CITIES...WHERE SOME AMOUNTS IN EXCESS OF AN
INCH STILL SEEM PLAUSIBLE. ELSEWHERE AN INCH OR LESS WITH SOME
REDUCTION IN SNOW RATIOS EXPECTED WITH THE LOW LEVEL PROFILE
WARMING WITH TIME.
COLD AIR ADVECTION QUICKLY ENSUES ON THE HEELS OF THIS SYSTEM
THROUGHOUT MONDAY. SHORT LIVED DRY SLOT FOR THE MORNING PERIOD
BEFORE A LAKE ENHANCED MOISTURE PLUME EXPANDS EASTWARD WITHIN THE
BACKGROUND OF COLD/CYCLONIC FLOW. THIS WILL SUPPORT AN EXTENSIVE
STRATUS DECK FOR MUCH OF THE DAY...AND ALLOW FOR SOME LIGHT SNOW
SHOWER/FLURRY PRODUCTION. THE MAIN ARCTIC BLAST WILL ACCOMPANY A
CLIPPER CRUISING THROUGH THE NORTHERN GREAT LAKES ON TUESDAY. A
TRAILING WAVE MAY REINFORCE THIS AIRMASS INTO WEDNESDAY...THE NET
RESULT BEING A STRETCH OF TEMPERATURES A GOOD 15 TO 20 DEGREES
BELOW NORMAL FOR THE 2ND WEEK IN DECEMBER. A SOLID GRADIENT
ATTENDANT TO THESE NORTHERN STREAM WAVES WILL PROVIDE THE
ADDITIVE WIND ELEMENT...RESULTING IN DAYTIME WIND CHILL READINGS
OF SINGLE DIGITS TUESDAY AND WEDNESDAY.
&&
.MARINE...
A STRONGER WESTERLY WIND WILL REMAIN IN PLACE TODAY ACROSS NORTHERN
LAKE HURON AS ARCTIC AIR CONTINUES TO FUNNEL ACROSS THE WATERS.
WINDS WILL DECREASE TONIGHT AND SUNDAY AS STRONG HIGH PRESSURE MOVES
THROUGH THE REGION. SOUTHEAST WINDS WILL STRENGTHEN AGAIN SUNDAY
NIGHT AS LOW PRESSURE TRACKS THROUGH LOWER MICHIGAN. WINDS WILL
SHIFT TO SOUTHWESTERLY IN THE WAKE OF THIS SYSTEM ON MONDAY.
INCREASING INSTABILITY AS ARCTIC AIR SPILLS BACK INTO THE REGION
WILL INTRODUCE THE POSSIBILITY FOR GALES MONDAY INTO MONDAY NIGHT.
&&
.AVIATION...ISSUED 1155 PM EST FRI DEC 6 2013
//DISCUSSION...
LAKE MOISTURE CONTINUES TO BRING IN STRATUS BETWEEN 2500 AND 3500
FEET TONIGHT WITH A WESTERLY FEED AT THE LOW LEVELS. THIS LAKE
MOISTURE HAS BEEN AFFECTING THE TAF SITES ON AN ON DURING THE
EVENING...MAINLY FNT AND MBS...BUT STILL MAKING IT ALL THE WAY TO
PTK AND DET. OVERALL THINKING IS MBS BEING CLOSER TO THE MOISTURE
SOURCE WILL BE MOST AT RISK...WITH LOWER CHANCES AT THE METRO
AIRPORTS. HIGH PRESSURE BUILDING IN ON SATURDAY WILL CLEAR OUT THIS
LAKE MOISTURE...LEAVING MOSTLY CLEAR SKIES FOR MUCH OF THE DAY.
FOR DTW...THINKING IS THAT THE AFOREMENTIONED LAKE MOISTURE WILL
ONLY BRING A FEW-SCT DECK AROUND 3K FT. HOWEVER THERE IS A SMALL
CHANCE FOR A BKN DECK AT THIS LEVEL FOR A PERIOD OF TIME OVERNIGHT
AND EARLY SATURDAY MORNING. AT THIS TIME CONFIDENCE IN A BKN DECK
FOR A LONG PERIOD OF TIME IS LOW ENOUGH TO LEAVE OUT OF THE TAFS.
//DTW THRESHOLD THREATS...
* LOW CONFIDENCE IN CEILINGS BELOW 5000 FEET OVERNIGHT.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LAKE HURON...NONE.
LAKE ST CLAIR...NONE.
MI WATERS OF LAKE ERIE...NONE.
&&
$$
SHORT TERM...CB
LONG TERM....MR
MARINE.......MR
AVIATION.....KURIMSKI
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
734 PM CST SUN DEC 8 2013
.SYNOPSIS...
ISSUED AT 326 PM CST SUN DEC 8 2013
H5 ANALYSIS FROM THIS MORNING HAS A HIGHLY AMPLIFIED
PATTERN ACROSS NOAM THIS MORNING WITH A RIDGE EXTENDING INTO THE
GULF OF ALASKA. A CLOSED LOW WAS OVER WESTERN PORTIONS OF THE HUDSON
BAY WITH A DEEP TROUGH OF LOW PRESSURE EXTENDING SSWD INTO THE
ROCKIES AND SWRN US. NUMEROUS EMBEDDED SHORTWAVES WERE NOTED ACROSS
THE WESTERN CONUS THIS MORNING. THE FIRST OVER SWRN WYOMING...WHICH
IS CROSSING CENTRAL COLORADO AND IS EMERGING ONTO THE FRONT RANGES
JUST SOUTH OF DENVER...PER SATELLITE AND RADAR IMAGERY. ANOTHER
SHORTWAVE WAS LOCATED OVER SWRN SASKATCHEWAN AND SRN ALBERTA...AND A
THIRD WAS NOTED OFF THE NRN CALIFORNIA COAST. AT THE SURFACE...AN
AREA OF SNOW IN ASSOCIATION WITH THE FIRST SHORTWAVE...EXTENDED FROM
AROUND LIMON COLORADO...NEWD TO FAR SOUTHWESTERN NEBRASKA. THE
HEAVIEST SNOW PER RADAR IMAGERY EXTENDED FROM NEAR LIMON COLORADO TO
NEAR IMPERIAL. THIS ACTIVITY HAS BEEN MOVING TO THE EAST NORTHEAST
AND IS EXPECTED TO REMAIN MAINLY SOUTH OF THE FORECAST AREA THIS
AFTERNOON. THE EXCEPTION IS ACROSS THE FAR SOUTHWESTERN COUNTIES
WHERE 1 TO 2 INCHES IS POSSIBLE THIS AFTERNOON. ELSEWHERE...ANY
ACCUMULATIONS ARE EXPECTED TO BE AN INCH OR LESS. AS OF 3 PM
CST...UNDER PARTLY TO MOSTLY CLOUDY SKIES...TEMPERATURES RANGED FROM
11 AT VALENTINE TO 17 AT OGALLALA.
&&
.UPDATE...
ISSUED AT 729 PM CST SUN DEC 8 2013
THE RAP AND HRRR TEMPERATURE AND WIND CHILL FORECASTS APPEAR TO BE
ON TRACK WITH KVTN SHOWING A WIND CHILL OF -26F AT 7 PM CST.
THERE ARE SOME MID CLOUDS MOVING IN FROM WY WHICH WILL LIMIT THE
AMOUNT OF TIME FOR RADIATIONAL COOLING. THUS CONDITIONS ARE NOT
FAVORABLE FOR ROCK BOTTOM LOWS BUT -10F TO -20F SHOULD DEVELOP
ALONG AND WEST OF HIGHWAY 83 TONIGHT.
TEMPS HAVE BEEN LOWERED IN THE NORTH AND A WIND CHILL WARNING IS
IN PLACE FROM VALENTINE WEST TO GORDON.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 326 PM CST SUN DEC 8 2013
SHORT WAVE MOVING ACROSS THE NEB/KS BORDER...WHICH MODELS HAVE
HANDLED FAIRLY WELL. LIGHT SNOW WILL BE TAPERING TO FLURRIES ACROSS
PORTIONS OF SOUTHWEST AND CENTRAL NEBRASKA BEFORE ENDING LATER THIS
EVENING. ADDITIONAL SNOWFALL COULD REACH UP TO THREE QUARTERS OF AN
INCH...HOWEVER MOST AREAS IN THE SE CWA TO SEE A COUPLE OF TENTHS.
CLEARING SKIES ARE ALREADY SEEN ON VISIBLE SAT ACROSS THE PANHANDLE
AND NW NEB. HIGH PRESSURE WILL BEGIN TO NOSE DOWN INTO THE AREA
TONIGHT...WHICH WILL COMBINE WITH THE SNOW PACK TO ALLOW FOR GOOD
RADIATIONAL COOLING. RECENT LOWS HAVE BEEN BELOW GUIDANCE WHEN SKIES
HAVE CLEARED...SO TOOK COOLER MAV GUIDANCE AND DROPPED A COUPLE OF
DEGREES...WHICH MAYBE CONSERVATIVE FOR PORTIONS OF THE NW
CWA...WHERE MORE THAN HALF A FOOT OF SNOW REMAINS ON THE GROUND.
THIS PLACES LOWS IN THE -5 TO -15 DEGREE RANGE. NORTHWEST WINDS
MOVING IN WITH THE CLEARING...ALTHOUGH THEY WILL BE DIMINISHING. THE
COMBINATION OF LIGHT WINDS AND BITTER COLD TEMPS WILL ALLOW FOR WIND
CHILLS TO FALL INTO THE -20 TO -30 RANGE...LOCALLY LOWER ACROSS NW
ZONES. WILL GO WITH A WIND CHILL ADVISORY FOR ENTIRE CWA.
TOMORROW MODELS HOLD 850 MB TEMPS FAIRLY STEADY...AND WITH MOSTLY
SUNNY SKIES EXPECT HIGHS TO REBOUND A LITTLE WARMER THAN
TODAY...HIGHS SHOULD REBOUND INTO THE TEENS TO NEAR 20.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 326 PM CST SUN DEC 8 2013
MONDAY NIGHT THROUGH WEDNESDAY...THE MAIN FORECASTING
CHALLENGES ARE TEMPERATURES...THEN LOW PRECIPITATION CHANCES FOR
TUESDAY NIGHT. ON MONDAY NIGHT...A SURFACE TROUGH OF LOW PRESSURE
WILL TRACK FROM THE CENTRAL PLAINS EAST INTO THE UPPER MIDWEST.
LIMITED CAA WILL ACCOMPANY PASSAGE OF THE TROUGH. HOWEVER...IT WILL
HELP TO KEEP THE LOW LEVEL WINDS MIXED ON MONDAY NIGHT...THUS MILDER
TEMPERATURES ARE EXPECTED. ALBEIT...LOWS WILL STILL BE COLD WITH
READINGS IN THE SINGLE DIGITS. ON TUESDAY...WESTERLY DOWNSLOPE WINDS
WILL CONTINUE INCREASE SOMEWHAT TO 10 TO 15 MPH. DECIDED TO UNDERCUT
GUIDANCE FOR HIGHS TUESDAY...BASED ON SNOW COVER AND LIMITED MIXING
POTENTIAL. THIS LED TO HIGHS MAINLY IN THE 20S...WITH SOME TEMPS
NEAR THE FREEZING MARK ACROSS THE FAR SOUTHWEST. ON TUESDAY
NIGHT...AN ARCTIC COLD FRONT WILL BACK INTO NORTHERN AND
NORTHEASTERN NEBRASKA WITH A NICE PV MAX ARRIVING OVERNIGHT. CROSS
SECTIONS ACROSS NORTHERN NEBRASKA ARE INDICATIVE OF SOME WEAK LIFT
IN THE DENDRITIC LAYER WHICH MAXES OUT AROUND 06Z WEDNESDAY. TOP
DOWN SATURATION WILL HAVE TO OCCUR WITH ANY PCPN WHICH MAY FALL...SO
WILL LIMIT POP MENTION TO SLIGHTS FOR NOW...AND KEEP POPS ACROSS THE
NRN CWA AS CROSS SECTIONS NEVER MOISTEN UP ACROSS THE SRN CWA. ON
WEDNESDAY SURFACE HIGH PRESSURE WILL BUILD INTO THE MID MISSOURI
VALLEY. WINDS WILL SHIFT TO THE SOUTHWEST DURING THE AFTERNOON
HOURS...AND WILL RECYCLE COLD AIR ACROSS THE FORECAST AREA. HIGHS
WILL BE COLD...RANGING FROM THE MIDDLE TEENS IN THE NORTHEAST...TO
THE UPPER 20S IN THE FAR SOUTHWEST.
WEDNESDAY NIGHT THROUGH SUNDAY...THE MID RANGE MODEL SOLUTIONS
CONTINUE TO INDICATE LOW AMPLITUDE WEST NORTHWESTERLY FLOW ACROSS
THE CONUS FOR THE END OF THE WEEK INTO EARLY NEXT WEEK. BOTH THE
ECMWF AND GFS SOLNS ARE TRENDING TOWARD THE DEVELOPMENT OF AN UPPER
LEVEL TROUGH EMBEDDED IN THE SRN STREAM TOWARD FRIDAY. BOTH SOLNS
LIFT THIS ENERGY SOUTH OF THE AREA...SO A DRY FORECAST CONTINUES.
AFTER TEMPERATURES TREND HIGHER FOR THURSDAY AND FRIDAY WITH HIGHS
IN THE 30S...COOLER TEMPERATURES WILL ARRIVE ON FRIDAY NIGHT AS AN
ARCTIC COLD FRONT BACKS INTO THE FORECAST AREA. HIGHS WILL BE COOLER
IN THE 20S AND LOWER 30S SATURDAY...FOLLOWED BY 30S AND LOWER 40S FOR
SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 527 PM CST SUN DEC 8 2013
VFR IS EXPECTED ALL AREAS TONIGHT AND MONDAY. A BATCH OF MID LEVEL
CLOUDS...CURRENTLY OVER NORTHEAST WY...WILL MOVE OVERHEAD TONIGHT
FOLLOWED BY SOME CLEARING MONDAY MORNING AND SCATTERED HIGH CLOUDS THEREAFTER.
NO FOG WAS INDICATED IN THE NAM OR HRRR MODELS TONIGHT.
INDICATIONS ARE THE REINFORCING ARCTIC FRONT MOVING THROUGH THE
FCST AREA WILL SCOUR ALL MOISTURE FROM AREA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST /11 AM MST/ MONDAY FOR NEZ007-
009-010-022>029-035>038-056>059-069>071.
WIND CHILL WARNING UNTIL NOON CST /11 AM MST/ MONDAY FOR
NEZ004>006-008-094.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...MASEK
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
527 PM CST SUN DEC 8 2013
.SYNOPSIS...
ISSUED AT 326 PM CST SUN DEC 8 2013
H5 ANALYSIS FROM THIS MORNING HAS A HIGHLY AMPLIFIED
PATTERN ACROSS NOAM THIS MORNING WITH A RIDGE EXTENDING INTO THE
GULF OF ALASKA. A CLOSED LOW WAS OVER WESTERN PORTIONS OF THE HUDSON
BAY WITH A DEEP TROUGH OF LOW PRESSURE EXTENDING SSWD INTO THE
ROCKIES AND SWRN US. NUMEROUS EMBEDDED SHORTWAVES WERE NOTED ACROSS
THE WESTERN CONUS THIS MORNING. THE FIRST OVER SWRN WYOMING...WHICH
IS CROSSING CENTRAL COLORADO AND IS EMERGING ONTO THE FRONT RANGES
JUST SOUTH OF DENVER...PER SATELLITE AND RADAR IMAGERY. ANOTHER
SHORTWAVE WAS LOCATED OVER SWRN SASKATCHEWAN AND SRN ALBERTA...AND A
THIRD WAS NOTED OFF THE NRN CALIFORNIA COAST. AT THE SURFACE...AN
AREA OF SNOW IN ASSOCIATION WITH THE FIRST SHORTWAVE...EXTENDED FROM
AROUND LIMON COLORADO...NEWD TO FAR SOUTHWESTERN NEBRASKA. THE
HEAVIEST SNOW PER RADAR IMAGERY EXTENDED FROM NEAR LIMON COLORADO TO
NEAR IMPERIAL. THIS ACTIVITY HAS BEEN MOVING TO THE EAST NORTHEAST
AND IS EXPECTED TO REMAIN MAINLY SOUTH OF THE FORECAST AREA THIS
AFTERNOON. THE EXCEPTION IS ACROSS THE FAR SOUTHWESTERN COUNTIES
WHERE 1 TO 2 INCHES IS POSSIBLE THIS AFTERNOON. ELSEWHERE...ANY
ACCUMULATIONS ARE EXPECTED TO BE AN INCH OR LESS. AS OF 3 PM
CST...UNDER PARTLY TO MOSTLY CLOUDY SKIES...TEMPERATURES RANGED FROM
11 AT VALENTINE TO 17 AT OGALLALA.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 326 PM CST SUN DEC 8 2013
SHORT WAVE MOVING ACROSS THE NEB/KS BORDER...WHICH MODELS HAVE
HANDLED FAIRLY WELL. LIGHT SNOW WILL BE TAPERING TO FLURRIES ACROSS
PORTIONS OF SOUTHWEST AND CENTRAL NEBRASKA BEFORE ENDING LATER THIS
EVENING. ADDITIONAL SNOWFALL COULD REACH UP TO THREE QUARTERS OF AN
INCH...HOWEVER MOST AREAS IN THE SE CWA TO SEE A COUPLE OF TENTHS.
CLEARING SKIES ARE ALREADY SEEN ON VISIBLE SAT ACROSS THE PANHANDLE
AND NW NEB. HIGH PRESSURE WILL BEGIN TO NOSE DOWN INTO THE AREA
TONIGHT...WHICH WILL COMBINE WITH THE SNOW PACK TO ALLOW FOR GOOD
RADIATIONAL COOLING. RECENT LOWS HAVE BEEN BELOW GUIDANCE WHEN SKIES
HAVE CLEARED...SO TOOK COOLER MAV GUIDANCE AND DROPPED A COUPLE OF
DEGREES...WHICH MAYBE CONSERVATIVE FOR PORTIONS OF THE NW
CWA...WHERE MORE THAN HALF A FOOT OF SNOW REMAINS ON THE GROUND.
THIS PLACES LOWS IN THE -5 TO -15 DEGREE RANGE. NORTHWEST WINDS
MOVING IN WITH THE CLEARING...ALTHOUGH THEY WILL BE DIMINISHING. THE
COMBINATION OF LIGHT WINDS AND BITTER COLD TEMPS WILL ALLOW FOR WIND
CHILLS TO FALL INTO THE -20 TO -30 RANGE...LOCALLY LOWER ACROSS NW
ZONES. WILL GO WITH A WIND CHILL ADVISORY FOR ENTIRE CWA.
TOMORROW MODELS HOLD 850 MB TEMPS FAIRLY STEADY...AND WITH MOSTLY
SUNNY SKIES EXPECT HIGHS TO REBOUND A LITTLE WARMER THAN
TODAY...HIGHS SHOULD REBOUND INTO THE TEENS TO NEAR 20.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 326 PM CST SUN DEC 8 2013
MONDAY NIGHT THROUGH WEDNESDAY...THE MAIN FORECASTING
CHALLENGES ARE TEMPERATURES...THEN LOW PRECIPITATION CHANCES FOR
TUESDAY NIGHT. ON MONDAY NIGHT...A SURFACE TROUGH OF LOW PRESSURE
WILL TRACK FROM THE CENTRAL PLAINS EAST INTO THE UPPER MIDWEST.
LIMITED CAA WILL ACCOMPANY PASSAGE OF THE TROUGH. HOWEVER...IT WILL
HELP TO KEEP THE LOW LEVEL WINDS MIXED ON MONDAY NIGHT...THUS MILDER
TEMPERATURES ARE EXPECTED. ALBEIT...LOWS WILL STILL BE COLD WITH
READINGS IN THE SINGLE DIGITS. ON TUESDAY...WESTERLY DOWNSLOPE WINDS
WILL CONTINUE INCREASE SOMEWHAT TO 10 TO 15 MPH. DECIDED TO UNDERCUT
GUIDANCE FOR HIGHS TUESDAY...BASED ON SNOW COVER AND LIMITED MIXING
POTENTIAL. THIS LED TO HIGHS MAINLY IN THE 20S...WITH SOME TEMPS
NEAR THE FREEZING MARK ACROSS THE FAR SOUTHWEST. ON TUESDAY
NIGHT...AN ARCTIC COLD FRONT WILL BACK INTO NORTHERN AND
NORTHEASTERN NEBRASKA WITH A NICE PV MAX ARRIVING OVERNIGHT. CROSS
SECTIONS ACROSS NORTHERN NEBRASKA ARE INDICATIVE OF SOME WEAK LIFT
IN THE DENDRITIC LAYER WHICH MAXES OUT AROUND 06Z WEDNESDAY. TOP
DOWN SATURATION WILL HAVE TO OCCUR WITH ANY PCPN WHICH MAY FALL...SO
WILL LIMIT POP MENTION TO SLIGHTS FOR NOW...AND KEEP POPS ACROSS THE
NRN CWA AS CROSS SECTIONS NEVER MOISTEN UP ACROSS THE SRN CWA. ON
WEDNESDAY SURFACE HIGH PRESSURE WILL BUILD INTO THE MID MISSOURI
VALLEY. WINDS WILL SHIFT TO THE SOUTHWEST DURING THE AFTERNOON
HOURS...AND WILL RECYCLE COLD AIR ACROSS THE FORECAST AREA. HIGHS
WILL BE COLD...RANGING FROM THE MIDDLE TEENS IN THE NORTHEAST...TO
THE UPPER 20S IN THE FAR SOUTHWEST.
WEDNESDAY NIGHT THROUGH SUNDAY...THE MID RANGE MODEL SOLUTIONS
CONTINUE TO INDICATE LOW AMPLITUDE WEST NORTHWESTERLY FLOW ACROSS
THE CONUS FOR THE END OF THE WEEK INTO EARLY NEXT WEEK. BOTH THE
ECMWF AND GFS SOLNS ARE TRENDING TOWARD THE DEVELOPMENT OF AN UPPER
LEVEL TROUGH EMBEDDED IN THE SRN STREAM TOWARD FRIDAY. BOTH SOLNS
LIFT THIS ENERGY SOUTH OF THE AREA...SO A DRY FORECAST CONTINUES.
AFTER TEMPERATURES TREND HIGHER FOR THURSDAY AND FRIDAY WITH HIGHS
IN THE 30S...COOLER TEMPERATURES WILL ARRIVE ON FRIDAY NIGHT AS AN
ARCTIC COLD FRONT BACKS INTO THE FORECAST AREA. HIGHS WILL BE COOLER
IN THE 20S AND LOWER 30S SATURDAY...FOLLOWED BY 30S AND LOWER 40S FOR
SUNDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z MONDAY EVENING)
ISSUED AT 527 PM CST SUN DEC 8 2013
VFR IS EXPECTED ALL AREAS TONIGHT AND MONDAY. A BATCH OF MID LEVEL
CLOUDS...CURRENTLY OVER NORTHEAST WY...WILL MOVE OVERHEAD TONIGHT
FOLLOWED BY SOME CLEARING MONDAY MORNING AND SCATTERED HIGH CLOUDS THEREAFTER.
NO FOG WAS INDICATED IN THE NAM OR HRRR MODELS TONIGHT.
INDICATIONS ARE THE REINFORCING ARCTIC FRONT MOVING THROUGH THE
FCST AREA WILL SCOUR ALL MOISTURE FROM AREA.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY FROM 9 PM CST /8 PM MST/ THIS EVENING TO
NOON CST /11 AM MST/ MONDAY FOR NEZ004>010-022>029-035>038-
056>059-069>071-094.
&&
$$
SYNOPSIS...CLB
SHORT TERM...MASEK
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1005 PM EST SUN DEC 8 2013
.SYNOPSIS...
A SYSTEM WILL BRING A ROUND OF LIGHT FREEZING DRIZZLE TONIGHT
THROUGH MORNING. MONDAY NIGHT THROUGH THURSDAY...ARCTIC AIR WILL WORK
INTO THE AREA. THIS WILL INCLUDE DEVELOPING ACCUMULATING LAKE
EFFECT SNOW SHOWERS EAST OF THE GREAT LAKES.
&&
.NEAR TERM /THROUGH MONDAY/...
1005 PM UPDATE...
HV DELAYED PCPN FURTHER BY SVRL HRS AS NEPA IS SEEING VRY LITTLE PCPN
ATTM, THO SRN TIER IS SEEING FLURRIES. KBUF 00Z RAOB STILL SHOWING
DRY AIR IN THE LOWEST 200MB AND THIS IS BEING CONFIRMED BY OBS
ACRS THE REGION. EMPHASIS NOW TURNS TO FRZG PCPN DRG THE OVRNGT
HRS AS SNOW/SLEET DOES NOT APPEAR TO BE THE BIG CONCERN. ATMOS
LOSES MOISTURE IN THE DENDRITE ZONE TONIGHT AS MOISTURE IN THE
AREA IS GETTING THE SQUEEZE PLAY BTWN THE COASTAL LOW AND GREAT
LKS LOW. THUS, HV UPDATED TO GO FRZG DRIZZLE AREAWIDE FOR TONIGHT
WITH A GLAZE OF ICE EXPECTED BY MRNG. THUS WL KEEP THE ADVISORY
GOING AS TEMPS RMN BLO FRZG AND ONLY VRY LGT QPF EXPECTED.
PREV DISCUSSIONS BLO...
630 PM UPDATE...
PRECIP IS TAKING QUITE AWHILE TO MV INTO FA AS IT SLOWLY WORKS ITS
WAY THRU PA. ACRS NEPA, OBS ARE STILL REPORTING CIGS RANGING FM
6-10KFT AND HIGHER ACRS CNTRL NY. 18Z RAOB OUT OF KBUF SHOWING THE
LOWEST 300MB STILL DRY, HELPING TO EVAPORATE QPF AS IT HEADS NWRD.
APPEARS AS THO 18Z GFS BUFKIT SNDGS HV A BETTER HANDLE ON LOW-LVL
DRY AIR WITH BLYR AT KAVP RMNG TOO DRY FOR SNOW THRU 00Z, WHEREAS
NAM, RAP AND ARW SNDGS INDICATING SNOW SHUD HV BEEN FALLING FOR
THE LAST SVRL HRS DOWN ACRS NEPA.
THUS HV BACKED OFF ON POPS FOR EARLY THIS EVNG WITH CHC LIGHT SNOW IN
NEPA NOT MVG IN FOR ANOTHER FEW HRS, SOMEWHERE BTWN 01Z AND 02Z.
THIS AREA OF LIGHT SNOW WL GRADUALLY SPREAD NORTH MVG INTO SRN
TIER BY 03Z AND OVRSPRD RMNDR OF THE AREA BY 06Z. QPF AMNTS
EXPECTED TO BE VRY LGT WITH QPF TOTALS THRU MRNG < 0.10 INCHES.
EXPECT SNOW TO CONT ACRS ENTIRE CWA THRU 06Z (A TAD LATER THAN
PREVIOUSLY THOUGHT) BFR GRADUALLY MIXING WITH SLEET AND EVENTUALLY
-FZRA/-FZDZ TWD DAYBREAK. EXPECT SNOW TO HANG ON LONGEST OVR NRN
ONEIDA CNTY WHERE COLD AIR WL BE DEEPEST. HAVING SAID ALL THIS
EXPECT JUST 1-2 INCHES OF SNOW AND SLEET ACCUMS, HIGHEST OVR EXTRM
ERN SXNS FM MOHAWK VLY DOWN THRU WRN CATS. APPEARS LKLY THAT ALL
AREAS WL SEE A GLAZE OF ICE BY MRNG, MAKING FOR HAZARDOUS TRAVEL
DRG THE MRNG COMMUTE.
315 PM UPDATE...
DOUBLE LOW SYSTEM...YET WE ARE IN BETWEEN...WITH ONE CENTER BY THE
NORTHERN GREAT LAKES AND THE OTHER OFFSHORE OF NEW JERSEY. FORCING
WITH THE SOUTHERN LOW HAS YIELDED A BAND OF HEAVY SNOW IN
SOUTHEAST PA THROUGH NJ...AS ANYONE WATCHING THE PHILADELPHIA
PRO FOOTBALL GAME CAN ATTEST. WE WILL STILL GET A PIECE OF THE
SYSTEM...WITH TOP DOWN MOISTENING YIELDING A BATCH OF SNOW THIS
EVENING SPREADING FROM SOUTHWEST TO NORTHEAST. HOWEVER...SHORTLY
AFTER SNOW ARRIVES...SATURATED LAYER BECOMES SHALLOW TO POINT THAT
TEMPERATURES WITHIN IT BECOME UNSUPPORTIVE OF ICE CRYSTAL
FORMATION...SO QUICK SOUTH-TO-NORTH TRANSITION TO WINTRY MIX OF
LIGHT SLEET AND FREEZING RAIN/DRIZZLE IS FORESEEN OVERNIGHT INTO
EARLY MONDAY...AND EVENTUALLY PLAIN RAIN/DRIZZLE DURING THE DAY
MONDAY.
WINTER WEATHER ADVISORY FOR ENTIRE AREA STILL LOOKS GOOD YET AS
PREVIOUSLY ADVERTISED THIS WILL DEFINITELY BE A LIGHT
PRECIPITATION EVENT. IT HAPPENS TO INCLUDE LIGHT FREEZING
RAIN/FREEZING DRIZZLE AND THUS THE POTENTIAL FOR HAZARDOUS TRAVEL
CONDITIONS ON UNTREATED ROADS...NECESSITATING THE ADVISORY. ONLY
FIGURING ON AN INCH OR LESS OF SNOW- SLEET ACCUMULATION /PERHAPS
CLOSER TO 2 INCHES IN CATSKILLS TO ONEIDA COUNTY/...AND UP TO A
TENTH OF AN INCH OF ICE ACCUMULATION...MOST PLACES LESS.
NON-DIURNAL TEMPERATURES TONIGHT...SLOWLY CLIMBING FROM UPPER 20S
THROUGH LOW 30S INTO MONDAY MORNING...EVENTUALLY REACHING HIGHS OF
MID 30S TO LOW 40S DURING THE DAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
130 PM UPDATE...
COLD AIR ADVECTION WILL DOMINATE THE SHORT TERM PERIOD...AS WELL
AS DEVELOPMENT OF WESTERLY-FLOW LAKE EFFECT SNOW FOR SOME.
DEPARTURE OF SYSTEM WELL TO OUR NORTHEAST...AS WELL AS SHALLOW
MOISTURE PROFILE AND WEST-SOUTHWEST FLOW...WILL KEEP THINGS FAIRLY
QUIET MONDAY NIGHT. INTO TUESDAY THOUGH...850MB TEMPERATURES WILL
DIP INTO THE LOWER TO MID TEENS BELOW ZERO CELSIUS WHILE INVERSION
WILL RISE TO DENDRITIC GROWTH LAYER...BEGINNING TO INITIATE BETTER
LAKE RESPONSES. NOT EXPECTING HEAVY ACCUMULATIONS TUESDAY ITSELF
WITH WSW FLOW KEEPING LAKE ONTARIO BAND MAINLY NORTH...YET PERHAPS
STILL SKIMMING NORTHERN ONEIDA COUNTY. HOWEVER...LAKE ERIE BAND
MAY ACTUALLY STRETCH WELL EAST INTO AT LEAST SOUTHERN TIER-FINGER
LAKES FOR AT LEAST SCATTERED SNOW SHOWERS AND PERHAPS BRIEF
HEAVIER BURSTS.
LAKE EFFECT CONTINUES TO BE FAVORABLE TUESDAY NIGHT INTO
WEDNESDAY...AS 1000-500MB THICKNESSES DROP FURTHER INTO THE MID
510S TO LOWER 520S DECAMETER RANGE. HIGHS WEDNESDAY ONLY 20S
AREAWIDE.
MODEL SOUNDINGS SUGGEST DENDRITIC GROWTH TEMPERATURES
DOMINATING THE 3-7 KFT AGL LAYER. PASSING SHORTWAVES THOUGH WILL
FLUCTUATE LOW LEVEL WINDS...WHICH WILL PUSH THE BANDS AROUND AND
ALSO COULD MIS ALIGN WINDS IN THE LOWEST LEVELS. WE WILL HAVE TO
WATCH NORTHERN ONEIDA COUNTY CLOSELY IN MODEL TRENDS FOR POTENTIAL
OF GETTING INVOLVED IN LAKE PROLIFIC ONTARIO SNOW BAND...WHICH
MUCH IF NOT MOST OF THE TIME WILL REMAIN JUST TO THE NORTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
215 PM EST UPDATE...
A VERY ACTIVE WEATHER PATTERN IS EXPECTED IN THE EXTENDED
FORECAST. MINOR ADJUSTMENTS WERE MADE TO THE PREVIOUS FORECAST AND
LEANED TOWARDS WPC GUIDANCE. VERY BROAD UPPER LEVEL LOW WILL
SLOWLY DRIFT NORTH AND EAST OF THE REGION RESULTING IN A MUCH
COOLER AIR MASS OVER THE REGION... THUS LE SNOW SHOWERS WILL BE
POSSIBLE THROUGH FRIDAY FOR CENTRAL NY. HIGH PRESSURE WILL BUILD
ACROSS NEW ENGLAND THIS WEEKEND WHICH WILL HELP TEMPS CREEP CLOSER
TOWARDS 32. WITH LARGE DIFFERENCE WITHIN GFS/ECMWF INTO THE
WEEKEND KEPT PREVIOUS FORECAST WITH A SLIGHT CHANCE FOR SNOW
SHOWERS.
&&
.AVIATION /03Z MONDAY THROUGH FRIDAY/...
TERMINALS ARE ALL PRESENTLY VFR UNDER MID CLDS AS LIGHT SNOW MOVES
IN FROM THE SW. THE HEAVIEST PRECIPITATION WILL REMAIN E AND S OF
OUR TERMINALS. HOWEVER CIGS AND VSBYS WILL DETERIORATE BETWEEN 00Z
AND 04Z FOR KAVP...KBGM...KELM AND KITH AS LIGHT SNOWS LOWER CIGS
TO MVFR WITH MVFR TO PATCHY IFR VSBYS IN SN INITIALLY. FARTHER N
VFR UNDER LWRG MID DECK THRU 6Z. AFTER 6Z...PTYPE BECOMES AN
ISSUE FOR OUR TERMINALS IN SC NY AND NE PA AS CIGS AVERAGE MVFR
WITH IFR SN. PRECIP WILL TURN OVER TO LIGHT FZDZ AND PL ACRS
KITH...KBGM...KAVP...KELM BETWEEN 6Z AND 10Z. FARTHER N AT KSYR
AND KRME MVFR LIGHT SNOW WILL MOVE IN MAINLY AFTER 6Z WITH THE
CHANGEOVER TO FZDZ OCCURRING BETWEEN 10Z AND 13Z. ALL TERMINALS
WILL TRANSITION TO RADZ BETWEEN 13Z AND 16Z WITH KRME AND KBGM
HOLDING ON TO FZDZ THE LONGEST. AS THE WARMER AIR MOVES IN MON
AM...CIGS WILL LOWER TO IFR AT KBGM/KRME AND KITH WITH MVFR REST
OF TAFS. BY MON PM...CONDITIONS WILL GRADUALLY IMPROVE TO VFR
UNDER SC MOST TAFS. KBGM/KRME LIKELY WILL HOLD ONTO MVFR CIG THRU
THE DAY.
OUTLOOK...
MON NIGHT... CONDITIONS SLOWLY IMPROVING TO VFR AT KBGM/KRME. VFR
REST OF TAFS.
TUE/WED/THU...SCT MVFR SYR/RME IN LAKE EFFECT SNOW SHOWERS. VFR
ELSEWHERE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR PAZ038>040-
043-044-047-048-072.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ015>018-
022>025-044-045-055-056-062.
WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR NYZ009-036-
037-046-057.
&&
$$
SYNOPSIS...MDP/PVN
NEAR TERM...MDP/PVN
SHORT TERM...MDP
LONG TERM...KAH
AVIATION...DJN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
644 PM EST SUN DEC 8 2013
.SYNOPSIS...
A SYSTEM WILL BRING A ROUND OF LIGHT MIXED PRECIPITATION TONIGHT
INTO MONDAY MORNING...STARTING AS LIGHT SNOW THIS EVENING AND
THEN TRANSITIONING TO LIGHT FREEZING RAIN...SLEET...AND FREEZING
DRIZZLE OVERNIGHT. MONDAY NIGHT THROUGH THURSDAY...ARCTIC AIR WILL
WORK INTO THE AREA. THIS WILL INCLUDE DEVELOPING ACCUMULATING
LAKE EFFECT SNOW SHOWERS EAST OF THE GREAT LAKES.
&&
.NEAR TERM /THROUGH MONDAY/...
630 PM UPDATE...
PRECIP IS TAKING QUITE AWHILE TO MV INTO FA AS IT SLOWLY WORKS ITS
WAY THRU PA. ACRS NEPA, OBS ARE STILL REPORTING CIGS RANGING FM
6-10KFT AND HIGHER ACRS CNTRL NY. 18Z RAOB OUT OF KBUF SHOWING THE
LOWEST 300MB STILL DRY, HELPING TO EVAPORATE QPF AS IT HEADS NWRD.
APPEARS AS THO 18Z GFS BUFKIT SNDGS HV A BETTER HANDLE ON LOW-LVL
DRY AIR WITH BLYR AT KAVP RMNG TOO DRY FOR SNOW THRU 00Z, WHEREAS
NAM, RAP AND ARW SNDGS INDICATING SNOW SHUD HV BEEN FALLING FOR
THE LAST SVRL HRS DOWN ACRS NEPA.
THUS HV BACKED OFF ON POPS FOR EARLY THIS EVNG WITH CHC LIGHT SNOW IN
NEPA NOT MVG IN FOR ANOTHER FEW HRS, SOMEWHERE BTWN 01Z AND 02Z.
THIS AREA OF LIGHT SNOW WL GRADUALLY SPREAD NORTH MVG INTO SRN
TIER BY 03Z AND OVRSPRD RMNDR OF THE AREA BY 06Z. QPF AMNTS
EXPECTED TO BE VRY LGT WITH QPF TOTALS THRU MRNG < 0.10 INCHES.
EXPECT SNOW TO CONT ACRS ENTIRE CWA THRU 06Z (A TAD LATER THAN
PREVIOUSLY THOUGHT) BFR GRADUALLY MIXING WITH SLEET AND EVENTUALLY
-FZRA/-FZDZ TWD DAYBREAK. EXPECT SNOW TO HANG ON LONGEST OVR NRN
ONEIDA CNTY WHERE COLD AIR WL BE DEEPEST. HAVING SAID ALL THIS
EXPECT JUST 1-2 INCHES OF SNOW AND SLEET ACCUMS, HIGHEST OVR EXTRM
ERN SXNS FM MOHAWK VLY DOWN THRU WRN CATS. APPEARS LKLY THAT ALL
AREAS WL SEE A GLAZE OF ICE BY MRNG, MAKING FOR HAZARDOUS TRAVEL
DRG THE MRNG COMMUTE.
PREV DISCUSSION BLO...
315 PM UPDATE...
DOUBLE LOW SYSTEM...YET WE ARE IN BETWEEN...WITH ONE CENTER BY THE
NORTHERN GREAT LAKES AND THE OTHER OFFSHORE OF NEW JERSEY. FORCING
WITH THE SOUTHERN LOW HAS YIELDED A BAND OF HEAVY SNOW IN
SOUTHEAST PA THROUGH NJ...AS ANYONE WATCHING THE PHILADELPHIA
PRO FOOTBALL GAME CAN ATTEST. WE WILL STILL GET A PIECE OF THE
SYSTEM...WITH TOP DOWN MOISTENING YIELDING A BATCH OF SNOW THIS
EVENING SPREADING FROM SOUTHWEST TO NORTHEAST. HOWEVER...SHORTLY
AFTER SNOW ARRIVES...SATURATED LAYER BECOMES SHALLOW TO POINT THAT
TEMPERATURES WITHIN IT BECOME UNSUPPORTIVE OF ICE CRYSTAL
FORMATION...SO QUICK SOUTH-TO-NORTH TRANSITION TO WINTRY MIX OF
LIGHT SLEET AND FREEZING RAIN/DRIZZLE IS FORESEEN OVERNIGHT INTO
EARLY MONDAY...AND EVENTUALLY PLAIN RAIN/DRIZZLE DURING THE DAY
MONDAY.
WINTER WEATHER ADVISORY FOR ENTIRE AREA STILL LOOKS GOOD YET AS
PREVIOUSLY ADVERTISED THIS WILL DEFINITELY BE A LIGHT
PRECIPITATION EVENT. IT HAPPENS TO INCLUDE LIGHT FREEZING
RAIN/FREEZING DRIZZLE AND THUS THE POTENTIAL FOR HAZARDOUS TRAVEL
CONDITIONS ON UNTREATED ROADS...NECESSITATING THE ADVISORY. ONLY
FIGURING ON AN INCH OR LESS OF SNOW- SLEET ACCUMULATION /PERHAPS
CLOSER TO 2 INCHES IN CATSKILLS TO ONEIDA COUNTY/...AND UP TO A
TENTH OF AN INCH OF ICE ACCUMULATION...MOST PLACES LESS.
NON-DIURNAL TEMPERATURES TONIGHT...SLOWLY CLIMBING FROM UPPER 20S
THROUGH LOW 30S INTO MONDAY MORNING...EVENTUALLY REACHING HIGHS OF
MID 30S TO LOW 40S DURING THE DAY.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
130 PM UPDATE...
COLD AIR ADVECTION WILL DOMINATE THE SHORT TERM PERIOD...AS WELL
AS DEVELOPMENT OF WESTERLY-FLOW LAKE EFFECT SNOW FOR SOME.
DEPARTURE OF SYSTEM WELL TO OUR NORTHEAST...AS WELL AS SHALLOW
MOISTURE PROFILE AND WEST-SOUTHWEST FLOW...WILL KEEP THINGS FAIRLY
QUIET MONDAY NIGHT. INTO TUESDAY THOUGH...850MB TEMPERATURES WILL
DIP INTO THE LOWER TO MID TEENS BELOW ZERO CELSIUS WHILE INVERSION
WILL RISE TO DENDRITIC GROWTH LAYER...BEGINNING TO INITIATE BETTER
LAKE RESPONSES. NOT EXPECTING HEAVY ACCUMULATIONS TUESDAY ITSELF
WITH WSW FLOW KEEPING LAKE ONTARIO BAND MAINLY NORTH...YET PERHAPS
STILL SKIMMING NORTHERN ONEIDA COUNTY. HOWEVER...LAKE ERIE BAND
MAY ACTUALLY STRETCH WELL EAST INTO AT LEAST SOUTHERN TIER-FINGER
LAKES FOR AT LEAST SCATTERED SNOW SHOWERS AND PERHAPS BRIEF
HEAVIER BURSTS.
LAKE EFFECT CONTINUES TO BE FAVORABLE TUESDAY NIGHT INTO
WEDNESDAY...AS 1000-500MB THICKNESSES DROP FURTHER INTO THE MID
510S TO LOWER 520S DECAMETER RANGE. HIGHS WEDNESDAY ONLY 20S
AREAWIDE.
MODEL SOUNDINGS SUGGEST DENDRITIC GROWTH TEMPERATURES
DOMINATING THE 3-7 KFT AGL LAYER. PASSING SHORTWAVES THOUGH WILL
FLUCTUATE LOW LEVEL WINDS...WHICH WILL PUSH THE BANDS AROUND AND
ALSO COULD MIS ALIGN WINDS IN THE LOWEST LEVELS. WE WILL HAVE TO
WATCH NORTHERN ONEIDA COUNTY CLOSELY IN MODEL TRENDS FOR POTENTIAL
OF GETTING INVOLVED IN LAKE PROLIFIC ONTARIO SNOW BAND...WHICH
MUCH IF NOT MOST OF THE TIME WILL REMAIN JUST TO THE NORTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
215 PM EST UPDATE...
A VERY ACTIVE WEATHER PATTERN IS EXPECTED IN THE EXTENDED
FORECAST. MINOR ADJUSTMENTS WERE MADE TO THE PREVIOUS FORECAST AND
LEANED TOWARDS WPC GUIDANCE. VERY BROAD UPPER LEVEL LOW WILL
SLOWLY DRIFT NORTH AND EAST OF THE REGION RESULTING IN A MUCH
COOLER AIR MASS OVER THE REGION... THUS LE SNOW SHOWERS WILL BE
POSSIBLE THROUGH FRIDAY FOR CENTRAL NY. HIGH PRESSURE WILL BUILD
ACROSS NEW ENGLAND THIS WEEKEND WHICH WILL HELP TEMPS CREEP CLOSER
TOWARDS 32. WITH LARGE DIFFERENCE WITHIN GFS/ECMWF INTO THE
WEEKEND KEPT PREVIOUS FORECAST WITH A SLIGHT CHANCE FOR SNOW
SHOWERS.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
TERMINALS ARE ALL PRESENTLY VFR UNDER MID CLDS AS LIGHT SNOW MOVES
IN FROM THE SW. THE HEAVIEST PRECIPITATION WILL REMAIN E AND S OF
OUR TERMINALS. HOWEVER CIGS AND VSBYS WILL DETERIORATE BETWEEN 00Z
AND 04Z FOR KAVP...KBGM...KELM AND KITH AS LIGHT SNOWS LOWER CIGS
TO MVFR WITH MVFR TO PATCHY IFR VSBYS IN SN INITIALLY. FARTHER N
VFR UNDER LWRG MID DECK THRU 6Z. AFTER 6Z...PTYPE BECOMES AN
ISSUE FOR OUR TERMINALS IN SC NY AND NE PA AS CIGS AVERAGE MVFR
WITH IFR SN. PRECIP WILL TURN OVER TO LIGHT FZDZ AND PL ACRS
KITH...KBGM...KAVP...KELM BETWEEN 6Z AND 10Z. FARTHER N AT KSYR
AND KRME MVFR LIGHT SNOW WILL MOVE IN MAINLY AFTER 6Z WITH THE
CHANGEOVER TO FZDZ OCCURRING BETWEEN 10Z AND 13Z. ALL TERMINALS
WILL TRANSITION TO RADZ BETWEEN 13Z AND 16Z WITH KRME AND KBGM
HOLDING ON TO FZDZ THE LONGEST. AS THE WARMER AIR MOVES IN MON
AM...CIGS WILL LOWER TO IFR AT KBGM/KRME AND KITH WITH MVFR REST
OF TAFS. BY MON PM...CONDITIONS WILL GRADUALLY IMPROVE TO VFR
UNDER SC MOST TAFS. KBGM/KRME LIKELY WILL HOLD ONTO MVFR CIG THRU
THE DAY.
OUTLOOK...
MON NIGHT... CONDITIONS SLOWLY IMPROVING TO VFR AT KBGM/KRME. VFR
REST OF TAFS.
TUE/WED/THU...SCT MVFR SYR/RME IN LAKE EFFECT SNOW SHOWERS. VFR
ELSEWHERE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR PAZ038>040-
043-044-047-048-072.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ015>018-
022>025-044-045-055-056.
WINTER WEATHER ADVISORY UNTIL 10 AM EST MONDAY FOR NYZ062.
WINTER WEATHER ADVISORY UNTIL 1 PM EST MONDAY FOR NYZ009-036-
037-046-057.
&&
$$
SYNOPSIS...MDP
NEAR TERM...MDP/PVN
SHORT TERM...MDP
LONG TERM...KAH
AVIATION...DJN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
118 PM EST SAT DEC 7 2013
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO SUNDAY MORNING EAST
OF LAKE ONTARIO...WHILE THE REMAINDER OF THE AREA WILL SEE
GENERALLY FAIR AND DRY WEATHER. THE NEXT STORM SYSTEM WILL BRING
ANOTHER ROUND OF MIXED PRECIPITATION SUNDAY NIGHT AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
VISIBLE SATELITE IMAGERY SHOWG STRATOCUMULUS ACRS A LARGE PART OF
NRN...CNTRL AND WRN PA AND PARTS OF SW NY AND NRN AND ERN NY. THE
LOW-LEVEL FLOW WILL BE ARND 280-290 DEGREES TODAY AND DIRECT LAKE
EFFECT MOISTURE INTO NC NY FROM LAKE ONTARIO AND INTO SW NY FROM
LAKE ERIE. LAKE ONTARIO WATER TEMPERATURES ARE RUNNING ARND 8C ON
THE WRN END AND WITH 850 MB TEMPS AT -14C OR SO WE HAVE A 22C
DIFFERNTIAL WHICH IS DECENT. HOWEVER...MODELS VARY ON THE AMNT OF
LOW-LEVEL MOISTURE COMING ACRS THE LAKE. THE GFS IS DRIER HAVING
SFC DWPTS ARND 20F WITH THE RAP AND NAM HAVING SFC DWPTS IN THE
MID TO UPPER 20S. THIS LEADS TO VARIATIONS IN THE SOUNDINGS AND
LES POTENTIAL. THE NAM/RAP WUD SUGGEST A POTENTIAL LAKE EFFECT
SNOW BAND AND MAYBE A FEW INCHES ACCUMULATION OR MORE. THE GFS IS
TOO DRY AND WE WUD SEE MAINLY LIGHTER ACC/S. THERE ALSO WAS SOME
SHEAR BELOW THE INVERSION TOO WHICH ALSO GOES AGAINST ADVY AMNTS.
SO FOR NOW WILL KEEP PREVIOUS FCST OF 1-3 INCHES DOWNWIND OF LAKE
ONTARIO WITH THE HIGHEST AMNTS ALONG THE THRUWAY CORRIDOR. WILL
KEEP FLURRIES FOR SW NY COUNTIES OF STEUBEN/YATES AND PARTS OF
CHEMUNG AND EVEN BRADFORD PA THIS PM. OTHERWISE WILL SEE PC TO MC
SKIES INTO TONIGHT.
FOR TONIGHT...THE LES CONTINUES DOWNWIND OF LAKE ONTARIO AND
LIKELY CONTRACTS BACK TWD LAKE ERIE SPARING STUEBEN CO DUE TO
WEAKER WINDS. SO WILL KEEP LES GOING IN NC NY TONIGHT AND TAPER
OFF THE FLURRIES IN SW NY COUNTIES. OTHERWISE PC REST OF AREA.
PREVIOUS DSCN...
3 AM UPDATE...
STEADY PRECIPITATION HAS NOW MOVED WELL SE OF THE AREA INTO SRN
NJ. LIGHT SNOW CONTINUES WITH LITTLE ACCUMULATION EARLY THIS
MORNING ENDING BY 12Z. DRIER AIR QUICKLY COMING EAST INTO NY AND
PA AS SEEN ON THE RADAR MOSAIC. BEHIND THIS COLDER AIR ON A WNW
LOW LEVEL FLOW WILL START THE LAKE EFFECT MACHINE. WITH
TEMPERATURE DIFFERENTIAL MARGINAL AND SYNOPTIC MOISTURE GONE LES
WILL BE WEAK. MOSTLY 1 OR 2 INCHES PER 12 HOURS...DESPITE A SINGLE
BAND ALONG THE THRUWAY IN ONONDAGA...MADISON...AND ONEIDA. TODAY
THE BAND WILL HAVE A GEORGIAN BAY CONNECTION ON A 290 FLOW. MODEL
DIFFERENCES TONIGHT ON WHEN THE BAND WILL SHIFT INTO JUST ONEIDA
AS THE FLOW SHIFTS TO 270. ATTM IT LOOKS LIKE A LULL LATE EVE THEN
WITH THE BAND DOWN THE LENGTH OF LAKE ONTARIO A WEAK RESURGENCE
LATE TONIGHT INTO SUNDAY MORNING. THE BAND WILL BE FIGHTING DRIER
SINKING AIR WITH A LARGE SFC HIGH MOVING EAST TO BE OVER THE NE US
SUN AFTN.
SNOW AMOUNTS WELL BELOW ADVISORY CRITERIA BUT BRIEF BURSTS COULD
PUT DOWN HALF AN INCH PER HOUR.
OUTSIDE OF THE LAKE EFFECT BAND IT SHOULD BE DRY WITH DECREASING
CLOUD COVER TODAY INCREASING LATE TONIGHT. DO NOT EXPECT A LAKE
ERIE SNOW BAND TO MAKE IT INTO STEUBEN COUNTY. SHORT FETCH AND NO
CONNECTION. RADARS UPSTREAM NOT SHOWING MUCH FOR LAKE EFFECT AND
LITTLE INLAND EXTENT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
3 AM UPDATE...
SUNDAY HIGH PRESSURE WILL TAKE CONTROL VERY BREIFLY BEFORE A WEAK
STORM MOVES NORTHEAST INTO THE AREA SUNDAY EVENING. PRECIP WILL
START AS SNOW BUT CHANGEOVER TO SLEET AND FREEZING RAIN QUICKLY
DURING THE OVERNIGHT AND MONDAY MORNING. MODELS KEEP QPF LOW WITH
LESS THAN TWO TENTHS NORTH AND MAYBE A THIRD OF AN INCH IN THE FAR
SOUTH. AT THIS EARLY POINT...SNOWFALL WILL BE MOSTLY UNDER 2
INCHES. MAYBE A LITTLE MORE IN THE SOUTHERN TUG OF ONEIDA COUNTY
CLOSER TO THE COLDER AIR AND OROGRAPHIC LIFT. THE BIGGER PROBLEM
WILL BE FREEZING RAIN FOR MUCH OF THE AREA. LIKE THE LAST EVENT
THE HIGHEST AMOUNTS POSSIBLY UP TO A TENTH OF AN INCH AT HIGHER
ELEVEATIONS IN THE POCONOS. BY NOON MONDAY SFC TEMPS WILL BE ABOVE
FREEZING. ALSO BY THAT TIME STEADY PRECIP WILL HAVE LIFTED NE OUT
OF THE AREA. MON AFTN INTO MON NGT A FEW LINGERING SHOWERS WILL
CHANGE FROM RAIN TO SNOW. CAA TOO COULD SET OFF SOME LAKE EFFECT
BUT FLOW SHOULD KEEP THE HEAVIEST OF THAT NORTH OF THE CWA EAST OF
LAKE ONTARIO.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
THE MED RNG WILL BE DOMINATED BY LAKE EFFECT SNOW...MODULATED BY
PASSING S/WV`S AND ASSCD SFC TROFS. MDLS SHOW ONE PASSING ON
TUE...AND ANOTHER ONE ON THURSDAY. AFTER THIS TIME...MED RNG
GUIDANCE DIVERGES WITH GFS SHOWING RIDGING WHILE THE EURO DROPS
DOWN ANOTHER CDFNT. GIVEN THIS...WE DEFAULTED TO WPC FOR THE
LATTER PDS...BUT MODIFIED CLD/POPS FIELDS TO SHOW LAKE EFFECT
POTNL THRU MID/LATE WEEK. BOTTOM LINE IS COLD TEMPS AND PDS OF
LAKE EFECT SNOW ACRS FAR NRN ZONES...AND PSBLY SOME -SHSN ACRS
THE SRN TIER AND NRN PA DUE TO INFLUENCE OF LAKE ERIE. GFS
PROFILES SUGGEST POTNL FOR SIG LES SNOW ACCUMS ACRS THE FAR NRN
ZONES.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
LAKE EFFECT SNOW SHOWERS TO THE E AND SE OF LAKE ONTARIO WILL BE
THE MAIN WEATHER FOCUS ACRS THE BGM CWA THIS FCST PD. RME WILL BE
THE MOST AFFECTED WITH IFR/MVFR THIS AFTN INTO THE OVRNGT
HRS (AND BRIEF PDS OF BLO ALT MINS)...WITH SOME IMPRVMNT AFTER 06Z AS
WRLY FLOW/SNOW SHOWERS BEGIN TO WEAKEN. SYR SHUD BE ON THE SRN
PERIPHERY OF THIS ACTIVITY THIS AFTN AND EVNG...WITH OCNL MVFR
CONDITIONS. ELSEWHERE ACRS CNTRL NY AND NE PA...VFR WILL PREVAIL
THIS AFTN INTO THE OVRNGT HRS...WITH VFR ALL SITES XPCTD ON SUN.
WINDS THIS AFTN W TO NW 10-15 KTS...DIMINISHING THIS EVNG AND BCMG
L&V ON SUN MRNG.
OUTLOOK...
SUN NGT/MON...WDSPRD IFR/MVFR MIXED PCPN AND SHRA.
TUE/WED/THU...SCT MVFR SYR/RME IN LAKE EFFECT SNOW SHOWERS. VFR
ELSEWHERE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/TAC
NEAR TERM...DJN
SHORT TERM...TAC
LONG TERM...
AVIATION...
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
116 PM EST SAT DEC 7 2013
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO SUNDAY MORNING EAST
OF LAKE ONTARIO...WHILE THE REMAINDER OF THE AREA WILL SEE
GENERALLY FAIR AND DRY WEATHER. THE NEXT STORM SYSTEM WILL BRING
ANOTHER ROUND OF MIXED PRECIPITATION SUNDAY NIGHT AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
VISIBLE SATELITE IMAGERY SHOWG STRATOCUMULUS ACRS A LARGE PART OF
NRN...CNTRL AND WRN PA AND PARTS OF SW NY AND NRN AND ERN NY. THE
LOW-LEVEL FLOW WILL BE ARND 280-290 DEGREES TODAY AND DIRECT LAKE
EFFECT MOISTURE INTO NC NY FROM LAKE ONTARIO AND INTO SW NY FROM
LAKE ERIE. LAKE ONTARIO WATER TEMPERATURES ARE RUNNING ARND 8C ON
THE WRN END AND WITH 850 MB TEMPS AT -14C OR SO WE HAVE A 22C
DIFFERNTIAL WHICH IS DECENT. HOWEVER...MODELS VARY ON THE AMNT OF
LOW-LEVEL MOISTURE COMING ACRS THE LAKE. THE GFS IS DRIER HAVING
SFC DWPTS ARND 20F WITH THE RAP AND NAM HAVING SFC DWPTS IN THE
MID TO UPPER 20S. THIS LEADS TO VARIATIONS IN THE SOUNDINGS AND
LES POTENTIAL. THE NAM/RAP WUD SUGGEST A POTENTIAL LAKE EFFECT
SNOW BAND AND MAYBE A FEW INCHES ACCUMULATION OR MORE. THE GFS IS
TOO DRY AND WE WUD SEE MAINLY LIGHTER ACC/S. THERE ALSO WAS SOME
SHEAR BELOW THE INVERSION TOO WHICH ALSO GOES AGAINST ADVY AMNTS.
SO FOR NOW WILL KEEP PREVIOUS FCST OF 1-3 INCHES DOWNWIND OF LAKE
ONTARIO WITH THE HIGHEST AMNTS ALONG THE THRUWAY CORRIDOR. WILL
KEEP FLURRIES FOR SW NY COUNTIES OF STEUBEN/YATES AND PARTS OF
CHEMUNG AND EVEN BRADFORD PA THIS PM. OTHERWISE WILL SEE PC TO MC
SKIES INTO TONIGHT.
FOR TONIGHT...THE LES CONTINUES DOWNWIND OF LAKE ONTARIO AND
LIKELY CONTRACTS BACK TWD LAKE ERIE SPARING STUEBEN CO DUE TO
WEAKER WINDS. SO WILL KEEP LES GOING IN NC NY TONIGHT AND TAPER
OFF THE FLURRIES IN SW NY COUNTIES. OTHERWISE PC REST OF AREA.
PREVIOUS DSCN...
3 AM UPDATE...
STEADY PRECIPITATION HAS NOW MOVED WELL SE OF THE AREA INTO SRN
NJ. LIGHT SNOW CONTINUES WITH LITTLE ACCUMULATION EARLY THIS
MORNING ENDING BY 12Z. DRIER AIR QUICKLY COMING EAST INTO NY AND
PA AS SEEN ON THE RADAR MOSAIC. BEHIND THIS COLDER AIR ON A WNW
LOW LEVEL FLOW WILL START THE LAKE EFFECT MACHINE. WITH
TEMPERATURE DIFFERENTIAL MARGINAL AND SYNOPTIC MOISTURE GONE LES
WILL BE WEAK. MOSTLY 1 OR 2 INCHES PER 12 HOURS...DESPITE A SINGLE
BAND ALONG THE THRUWAY IN ONONDAGA...MADISON...AND ONEIDA. TODAY
THE BAND WILL HAVE A GEORGIAN BAY CONNECTION ON A 290 FLOW. MODEL
DIFFERENCES TONIGHT ON WHEN THE BAND WILL SHIFT INTO JUST ONEIDA
AS THE FLOW SHIFTS TO 270. ATTM IT LOOKS LIKE A LULL LATE EVE THEN
WITH THE BAND DOWN THE LENGTH OF LAKE ONTARIO A WEAK RESURGENCE
LATE TONIGHT INTO SUNDAY MORNING. THE BAND WILL BE FIGHTING DRIER
SINKING AIR WITH A LARGE SFC HIGH MOVING EAST TO BE OVER THE NE US
SUN AFTN.
SNOW AMOUNTS WELL BELOW ADVISORY CRITERIA BUT BRIEF BURSTS COULD
PUT DOWN HALF AN INCH PER HOUR.
OUTSIDE OF THE LAKE EFFECT BAND IT SHOULD BE DRY WITH DECREASING
CLOUD COVER TODAY INCREASING LATE TONIGHT. DO NOT EXPECT A LAKE
ERIE SNOW BAND TO MAKE IT INTO STEUBEN COUNTY. SHORT FETCH AND NO
CONNECTION. RADARS UPSTREAM NOT SHOWING MUCH FOR LAKE EFFECT AND
LITTLE INLAND EXTENT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
3 AM UPDATE...
SUNDAY HIGH PRESSURE WILL TAKE CONTROL VERY BREIFLY BEFORE A WEAK
STORM MOVES NORTHEAST INTO THE AREA SUNDAY EVENING. PRECIP WILL
START AS SNOW BUT CHANGEOVER TO SLEET AND FREEZING RAIN QUICKLY
DURING THE OVERNIGHT AND MONDAY MORNING. MODELS KEEP QPF LOW WITH
LESS THAN TWO TENTHS NORTH AND MAYBE A THIRD OF AN INCH IN THE FAR
SOUTH. AT THIS EARLY POINT...SNOWFALL WILL BE MOSTLY UNDER 2
INCHES. MAYBE A LITTLE MORE IN THE SOUTHERN TUG OF ONEIDA COUNTY
CLOSER TO THE COLDER AIR AND OROGRAPHIC LIFT. THE BIGGER PROBLEM
WILL BE FREEZING RAIN FOR MUCH OF THE AREA. LIKE THE LAST EVENT
THE HIGHEST AMOUNTS POSSIBLY UP TO A TENTH OF AN INCH AT HIGHER
ELEVEATIONS IN THE POCONOS. BY NOON MONDAY SFC TEMPS WILL BE ABOVE
FREEZING. ALSO BY THAT TIME STEADY PRECIP WILL HAVE LIFTED NE OUT
OF THE AREA. MON AFTN INTO MON NGT A FEW LINGERING SHOWERS WILL
CHANGE FROM RAIN TO SNOW. CAA TOO COULD SET OFF SOME LAKE EFFECT
BUT FLOW SHOULD KEEP THE HEAVIEST OF THAT NORTH OF THE CWA EAST OF
LAKE ONTARIO.
&&
.LONG TERM /TUESDAY THROUGH SATURDAY/...
THE MED RNG WILL BE DOMINATED BY LAKE EFFECT SNOW...MODULATED BY
PASSING S/WV`S AND ASSCD SFC TROFS. MDLS SHOW ONE PASSING ON
TUE...AND ANOTHER ONE ON THURSDAY. AFTER THIS TIME...MED RNG
GUIDANCE DIVERGES WITH GFS SHOWING RIDGING WHILE THE EURO DROPS
DOWN ANOTHER CDFNT. GIVEN THIS...WE DEFAULTED TO WPC FOR THE
LATTER PDS...BUT MODIFIED CLD/POPS FIELDS TO SHOW LAKE EFFECT
POTNL THRU MID/LATE WEEK. BOTTOM LINE IS COLD TEMPS AND PDS OF
LAKE EFECT SNOW ACRS FAR NRN ZONES...AND PSBLY SOME -SHSN ACRS
THE SRN TIER AND NRN PA DUE TO INFLUENCE OF LAKE ERIE. GFS
PROFILES SUGGEST POTNL FOR SIG LES SNOW ACCUMS ACRS THE FAR NRN
ZONES.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
LAKE EFFECT SNOW SHOWERS TO THE E AND SE OF LAKE ONTARIO WILL BE
THE MAIN WEATHER FOCUS ACRS THE BGM CWA THIS FCST PD. RME WILL BE
THE MOST AFFECTED WITH IFR/MVFR THIS AFTN INTO THE OVRNGT
HRS (AND BRIEF PDS OF BLO ALT MINS)...WITH SOME IMPRVMNT AFTER 06Z AS
WRLY FLOW.SNOW SHOWERS BEGIN TO WEAKEN. SYR SHUD BE ON THE SRN
PERIPHERY OF THIS ACTIVITY THIS AFTN AND EVNG...WITH OCNL MVFR
CONDITIONS. ELSEWHERE ACRS CNTRL NY AND NE PA...VFR WILL PREVAIL
THIS AFTN INTO THE OVRNGT HRS...WITH VFR ALL SITES XPCTD ON SUN.
WINDS THIS AFTN W TO NE 10-15 KTS...DIMINISHING THIS EVNG AND BCMG
L&V ON SUN MRNG.
OUTLOOK...
SUN NGT/MON...WDSPRD IFR/MVFR MIXED PCPN AND SHRA.
TUE/WED/THU...SCT MVFR SYR/RME IN LAKE EFFECT SNOW SHOWERS. VFR
ELSEWHERE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/TAC
NEAR TERM...DJN
SHORT TERM...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
944 AM EST SAT DEC 7 2013
.SYNOPSIS...
LAKE EFFECT SNOW SHOWERS WILL CONTINUE INTO SUNDAY MORNING EAST
OF LAKE ONTARIO...WHILE THE REMAINDER OF THE AREA WILL SEE
GENERALLY FAIR AND DRY WEATHER. THE NEXT STORM SYSTEM WILL BRING
ANOTHER ROUND OF MIXED PRECIPITATION SUNDAY NIGHT AND MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
930 AM UPDATE...
VISIBLE SATELITE IMAGERY SHOWG STRATOCUMULUS ACRS A LARGE PART OF
NRN...CNTRL AND WRN PA AND PARTS OF SW NY AND NRN AND ERN NY. THE
LOW-LEVEL FLOW WILL BE ARND 280-290 DEGREES TODAY AND DIRECT LAKE
EFFECT MOISTURE INTO NC NY FROM LAKE ONTARIO AND INTO SW NY FROM
LAKE ERIE. LAKE ONTARIO WATER TEMPERATURES ARE RUNNING ARND 8C ON
THE WRN END AND WITH 850 MB TEMPS AT -14C OR SO WE HAVE A 22C
DIFFERNTIAL WHICH IS DECENT. HOWEVER...MODELS VARY ON THE AMNT OF
LOW-LEVEL MOISTURE COMING ACRS THE LAKE. THE GFS IS DRIER HAVING
SFC DWPTS ARND 20F WITH THE RAP AND NAM HAVING SFC DWPTS IN THE
MID TO UPPER 20S. THIS LEADS TO VARIATIONS IN THE SOUNDINGS AND
LES POTENTIAL. THE NAM/RAP WUD SUGGEST A POTENTIAL LAKE EFFECT
SNOW BAND AND MAYBE A FEW INCHES ACCUMULATION OR MORE. THE GFS IS
TOO DRY AND WE WUD SEE MAINLY LIGHTER ACC/S. THERE ALSO WAS SOME
SHEAR BELOW THE INVERSION TOO WHICH ALSO GOES AGAINST ADVY AMNTS.
SO FOR NOW WILL KEEP PREVIOUS FCST OF 1-3 INCHES DOWNWIND OF LAKE
ONTARIO WITH THE HIGHEST AMNTS ALONG THE THRUWAY CORRIDOR. WILL
KEEP FLURRIES FOR SW NY COUNTIES OF STEUBEN/YATES AND PARTS OF
CHEMUNG AND EVEN BRADFORD PA THIS PM. OTHERWISE WILL SEE PC TO MC
SKIES INTO TONIGHT.
FOR TONIGHT...THE LES CONTINUES DOWNWIND OF LAKE ONTARIO AND
LIKELY CONTRACTS BACK TWD LAKE ERIE SPARING STUEBEN CO DUE TO
WEAKER WINDS. SO WILL KEEP LES GOING IN NC NY TONIGHT AND TAPER
OFF THE FLURRIES IN SW NY COUNTIES. OTHERWISE PC REST OF AREA.
PREVIOUS DSCN...
3 AM UPDATE...
STEADY PRECIPITATION HAS NOW MOVED WELL SE OF THE AREA INTO SRN
NJ. LIGHT SNOW CONTINUES WITH LITTLE ACCUMULATION EARLY THIS
MORNING ENDING BY 12Z. DRIER AIR QUICKLY COMING EAST INTO NY AND
PA AS SEEN ON THE RADAR MOSAIC. BEHIND THIS COLDER AIR ON A WNW
LOW LEVEL FLOW WILL START THE LAKE EFFECT MACHINE. WITH
TEMPERATURE DIFFERENTIAL MARGINAL AND SYNOPTIC MOISTURE GONE LES
WILL BE WEAK. MOSTLY 1 OR 2 INCHES PER 12 HOURS...DESPITE A SINGLE
BAND ALONG THE THRUWAY IN ONONDAGA...MADISON...AND ONEIDA. TODAY
THE BAND WILL HAVE A GEORGIAN BAY CONNECTION ON A 290 FLOW. MODEL
DIFFERENCES TONIGHT ON WHEN THE BAND WILL SHIFT INTO JUST ONEIDA
AS THE FLOW SHIFTS TO 270. ATTM IT LOOKS LIKE A LULL LATE EVE THEN
WITH THE BAND DOWN THE LENGTH OF LAKE ONTARIO A WEAK RESURGENCE
LATE TONIGHT INTO SUNDAY MORNING. THE BAND WILL BE FIGHTING DRIER
SINKING AIR WITH A LARGE SFC HIGH MOVING EAST TO BE OVER THE NE US
SUN AFTN.
SNOW AMOUNTS WELL BELOW ADVISORY CRITERIA BUT BRIEF BURSTS COULD
PUT DOWN HALF AN INCH PER HOUR.
OUTSIDE OF THE LAKE EFFECT BAND IT SHOULD BE DRY WITH DECREASING
CLOUD COVER TODAY INCREASING LATE TONIGHT. DO NOT EXPECT A LAKE
ERIE SNOW BAND TO MAKE IT INTO STEUBEN COUNTY. SHORT FETCH AND NO
CONNECTION. RADARS UPSTREAM NOT SHOWING MUCH FOR LAKE EFFECT AND
LITTLE INLAND EXTENT.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
3 AM UPDATE...
SUNDAY HIGH PRESSURE WILL TAKE CONTROL VERY BREIFLY BEFORE A WEAK
STORM MOVES NORTHEAST INTO THE AREA SUNDAY EVENING. PRECIP WILL
START AS SNOW BUT CHANGEOVER TO SLEET AND FREEZING RAIN QUICKLY
DURING THE OVERNIGHT AND MONDAY MORNING. MODELS KEEP QPF LOW WITH
LESS THAN TWO TENTHS NORTH AND MAYBE A THIRD OF AN INCH IN THE FAR
SOUTH. AT THIS EARLY POINT...SNOWFALL WILL BE MOSTLY UNDER 2
INCHES. MAYBE A LITTLE MORE IN THE SOUTHERN TUG OF ONEIDA COUNTY
CLOSER TO THE COLDER AIR AND OROGRAPHIC LIFT. THE BIGGER PROBLEM
WILL BE FREEZING RAIN FOR MUCH OF THE AREA. LIKE THE LAST EVENT
THE HIGHEST AMOUNTS POSSIBLY UP TO A TENTH OF AN INCH AT HIGHER
ELEVEATIONS IN THE POCONOS. BY NOON MONDAY SFC TEMPS WILL BE ABOVE
FREEZING. ALSO BY THAT TIME STEADY PRECIP WILL HAVE LIFTED NE OUT
OF THE AREA. MON AFTN INTO MON NGT A FEW LINGERING SHOWERS WILL
CHANGE FROM RAIN TO SNOW. CAA TOO COULD SET OFF SOME LAKE EFFECT
BUT FLOW SHOULD KEEP THE HEAVIEST OF THAT NORTH OF THE CWA EAST OF
LAKE ONTARIO.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
3 AM UPDATE...CURRENT EXTENDED IN GOOD SHAPE ONLY CHANGE WAS TO
INCREASE POPS INTO THE LIKELY CATEGORY TUESDAY NIGHT THROUGH
WEDNESDAY NIGHT OVER NRN ONEIDA COUNTY WHEN LAKE EFFECT SNOW LOOKS
MOST PROBABLE DUE TO WELL ALIGNED FLOW.
PREVIOUS DISC...
TUESDAY THROUGH THURSDAY WILL BE DOMINATED BY COLD WESTERLY FLOW
WITH SOME LAKE EFFECT SNOW DOWNSTREAM OF LAKES ONTARIO AND ERIE. A
SHORT WAVE WILL PASS ACROSS THE AREA ON TUESDAY ACCOMPANIED BY
SCATTERED SNOW SHOWERS AND FOLLOWED BY WHAT LOOKS LIKE A WELL-
ORGANIZED AND ALIGNED WESTERLY FLOW LAKE EFFECT SNOW EVENT
WEDNESDAY INTO THURSDAY. TOO EARLY FOR DETAILS BUT A POTENTIALLY
SIGNIFICANT LAKE EFFECT SNOW EVENT DOES APPEAR POSSIBLE. OTHERWISE
THE TUESDAY THROUGH THURSDAY PERIOD WILL BE RATHER QUIET FOR MOST
OF OUR AREA WITH SCATTERED FLURRIES OR LIGHT SNOW SHOWERS AND
UNSEASONABLY COLD TEMPERATURES.
&&
.AVIATION /14Z SATURDAY THROUGH WEDNESDAY/...
COLD NORTHWEST FLOW WILL PRODUCE MVFR/LOW VFR STRATO CU TODAY
ACROSS ALL TERMINALS. AT KSYR, LAKE EFFECT SNOW SHOWERS WILL MAKE
FOR MVFR SNOW SHOWERS THROUGH LATE AFTERNOON WHEN ACTIVITY WILL
LIFT NORTH OF AREA AS LOW LEVEL FLOW BACKS. AT KRME, FLURRIES WITH
MVFR/LOW VFR CIGS WILL PERSIST THROUGH LATE AFTERNOON WHEN FLOW
WILL BECOME MORE FAVORABLE FOR MVFR SNOW SHOWERS THROUGH THE
OVERNIGHT PERIOD.
AT KITH/KELM/KBGM/KAVP, CONDITIONS OVERNIGHT SHOULD BE PRIMARILY
VFR WITH SCATTERED CLOUDS AROUND 4K FT AS LOW LEVEL FLOW BACKS AND
SOME LOW LEVEL DRYING OCCURS.
NORTHWEST WINDS AROUND 10 KNOTS WITH GUSTS AROUND 15-18 KNOTS
DECREASING TO 5 KNOTS THIS EVENING.
OUTLOOK...
SUN...VFR.
SUN NGT/MON...WDSPRD IFR/MVFR IN RAIN AND MIXED PCPN.
TUE/WED...SCT MVFR MAINLY SYR/RME.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN/TAC
NEAR TERM...DJN
SHORT TERM...TAC
LONG TERM...MSE/RRM
AVIATION...RRM
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
644 AM EST SAT DEC 7 2013
.SYNOPSIS...
A STRONG COLD FRONT WILL MOVE THROUGH TODAY. CHILLY HIGH PRESSURE
WILL BRING A DAMP AND COOL COUPLE OF DAYS. MONDAY WILL BRIEFLY TURN
WARMER AGAIN BEFORE ANOTHER COLD FRONT PUSHES THROUGH ON TUESDAY
WITH THE BEST CHANCE OF RAIN. THE REMAINDER OF THE FORECAST WILL
BE COOLER AND DRIER.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM SATURDAY...THE SFC COLD FRONT CURRENTLY EXTENDING
FROM ALLIGATOR RIVER ACROSS RDU TO CLT...WILL DROP TO THE SOUTH
THIS MORNING AND REACH THE NORTHERN PORTIONS OF THE ILM CWA BY
MID-MORNING. THE COLD FRONT WILL CONTINUE TO DROP SOUTH AND CLEAR
THE ILM CWA BY MID TO LATE THIS AFTERNOON...VIA LATEST HRRR MODEL
SFC WIND PLOTS. LOOKING AT LIGHT TO MODERATE RAIN SHOWERS AHEAD
AND IMMEDIATELY ALONG THE COLD FRONT...GIVING WAY TO POST FRONTAL
PCPN IN THE FORM OF STRATIFORM LIGHT RAINS AND DRIZZLE. THE SFC
PRESSURE PATTERN LATER TONIGHT INTO SUNDAY WILL REFLECT A COLD AIR
DAMMING EVENT WITH A NEARLY SATURATED ATMOSPHERE FROM THE SFC TO
700MB KEEPING SKIES CLOUDY AND THE CONTINUED THREAT OF THE
AFOREMENTIONED PCPN.
TODAYS MAX TEMPS WILL LIKELY OCCUR JUST PRIOR TO THE COLD FRONTAL
PASSAGE...FOLLOWED BY DECENT CAA AND A RATHER STEADY DECLINE OF
TEMPS AFTER ITS PASSAGE. THE COLD AIR WILL REMAIN QUITE SHALLOW
AS EVIDENCED WITH MODEL PROGGED 1000-500 MB THICKNESS...IE. FROM
562-567DAM THIS MORNING TO ONLY 558-562DAM BY SUNRISE SUNDAY. AT
THE SAME TIME...SFC TEMPS IN THE 60S TO AROUND 70 THIS MORNING
...WILL DROP INTO THE 50S THIS AFTERNOON...AND THROUGH THE 40S
TONIGHT WITH UPPER 30S POSSIBLE ACROSS THE NW PORTIONS OF THE ILM
CWA.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...THE SHORT TERM FORECAST CONTINUES TO BE
HIGHLIGHTED BY CHANGEABLE CONDITIONS AS A COLD AIR WEDGE SUNDAY
TRANSITIONS TO A WARM AND SOUTHWEST FLOW AHEAD OF A COLD FRONT
MONDAY...ALL OF THIS UNDER A SOUTHWEST FLOW ALOFT.
I HAVE MADE ONLY SMALL ADJUSTMENTS TO POPS TO WALK BACK VALUES FOR
MONDAY AND INCREASE VALUES FOR MONDAY NIGHT AS THE MID LEVEL FORCING
COUPLES WITH THE APPROACHING FRONT. DIDNOT FEEL CONFIDENT ENOUGH TO
MAKE CHANGES TO SUNDAYS VALUES AS WE CONTINUE TO EMPHASIZE LOW QPF
AMOUNTS.
ONCE AGAIN LOW CONFIDENCE WITH REGARDS TO THE TEMPERATURE FORECAST
ALTHOUGH IT IS WORTH NOTING GUIDANCE HAS BEEN QUITE STABLE WITH THE
CHANGEABLE CONDITIONS. LEANED TOWARD THE LOWER MET GUIDANCE THROUGH
THE PERIOD.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 3 AM SATURDAY...THE MAIN FEATURE FOR THE EXTENDED NOW SHIFTS
TO THE FRONT MOVING ACROSS TUESDAY AND THE LATEST MEDIUM RANGE
GUIDANCE AS WELL AS WPC CONTINUES TO ADVERTISE A LATE TUESDAY
ARRIVAL. THE REMAINDER OF THE PERIOD WILL FEATURE HIGH PRESSURE
BUILDING IN FROM THE WEST NORTHWEST AS A MODIFIED VERSION OF THE
BITTER COLD AIRMASS NOW ACROSS THE PLAINS MOVES ACROSS. THE END OF
THE PERIOD WILL SEE A VERY FAMILIAR FEATURE ESPECIALLY AS OF LATE
WITH THE POSSIBLE DEVELOPMENT OF A WEAKLY FORCED COASTAL TROUGH.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 12Z...COLD FRONT MARCHING SOUTHWARD...EXPECTED TO REACH THE
NORTHERN PORTION OF THE CWA SHORTLY AFTER TAF ISSUANCE. UPSTREAM
STATIONS SHOW SPORADIC IFR CONDITIONS. THERE WILL BE A NOTICEABLE
WIND SHIFT TO THE NORTH...TRANSITIONING IN A 1-2 HOUR TIME FRAME.
THERE IS SOME LIFT ALONG THE FRONTAL BOUNDARY...BUT ITS MORE
PARALLEL THAN PERPENDICULAR...SO MOST OF THE RAIN WILL BE
FLEETING...ONLY ISOLATED RAIN/DRIZZLE THIS AFTERNOON. TEMPERATURES
WILL FALL FROM MIDDAY THROUGH THE AFTERNOON HOURS. IFR WEDGE STRATUS
IS EXPECTED THROUGH THE OVERNIGHT HOURS.
EXTENDED OUTLOOK...UNSETTLED WEATHER THROUGH THE EXTENDED WITH
INTERMITTENT IFR/MVFR CONDITIONS DUE TO A NEARLY STATIONARY FRONT.
&&
.MARINE...
NEAR TERM/THROUGH TONIGHT/...
AS OF 345 AM SATURDAY...SCA REMAINS IN EFFECT FOR THE ILM COASTAL
WATERS THROUGH MIDDAY SUNDAY TO ACCOUNT FOR THE POST FRONTAL N-NE
SURGE AND RESULTANT SIGNIFICANT SEAS.
MODELS INDICATE THE COLD FRONT WILL DROP FROM NNW TO SSE TODAY...
WHICH IS NEARLY COMPARABLE TO A BACK-DOOR COLD FRONT.
HOWEVER...AFTER THE PASSAGE OF THIS COLD FRONT...THE AREA WATERS
WILL BE SUBJECT TO A DECENT PUSH OF POST FRONTAL N-NE WINDS FROM
THE COMBINED EFFECTS OF A TIGHTENED SFC PG AND DECENT COLD AIR
ADVECTION. THE LOCAL WATERS WILL BE LOOKING AT POST FRONTAL N-NE
WINDS AT 15 TO 25 KT WITH GUSTS UP TO 30 KT LATE THIS AFTERNOON
THROUGH TONIGHT. SIGNIFICANT SEAS INITIALLY IN THE 2 TO 4 FT RANGE
MAINLY FROM THE EARLIER S-SW WIND WAVE ACTION...WILL BUILD TO A
PEAK OF 4 TO 7 FT TONIGHT. AGAIN...WIND DRIVEN WAVES WILL DOMINATE
THE SIGNIFICANT SEAS WITH AVERAGE PERIODS AROUND 5 SECONDS.
SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
AS OF 3 AM SATURDAY...MOST OF SUNDAY WILL SEE A NORTHEASTERLY FLOW
ACROSS ALL WATERS WITH INITIAL SPEEDS OF 20-25 KNOTS MOSTLY TOWARD
THE LOWER END OF THE RANGE. THE WEDGE WILL WEAKEN OVERNIGHT SUNDAY
INTO MONDAY MORNING AS A SOUTH THEN SOUTHWEST FLOW DEVELOPS. SPEEDS
WILL INCREASE TO 15-20 KNOTS ONCE AGAIN AND CONTINUE INTO TUESDAY
MORNING. SEAS WILL SHOW THE VARIABILITY OF THE WINDS AS A RESIDUAL
RANGE OF 3-5 FEET WILL DROP TO 2-4 FEET EARLY MONDAY INCREASING ONCE
AGAIN BY EARLY TUESDAY.
LONG TERM /TUESDAY THROUGH WEDNESDAY/...
AS OF 3 AM SATURDAY...THE WIND SHIFT WITH THE FRONT WILL BE THE BIG
EVENT FOR THE EXTENDED COASTAL WATERS FORECAST. THE FRONT SHOULD
CROSS THE WATERS IN THE AFTERNOON WITH A NORTHERLY FLOW IN PLACE BY
0000 UTC WEDNESDAY. SPEEDS SHOULD BE 15-20 KNOTS. FOR WEDNESDAY THE
FLOW WILL VEER MORE TO NORTHEAST AND CONTINUE IN A 15-20 KNOT RANGE
PROBABLY EDGING CLOSER TO 15 FOR MOST OF THE AFTERNOON. EXPECT SEAS
OF 2-4 FEET.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL NOON EST SUNDAY FOR AMZ250-252-254-
256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...DCH
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
353 AM EST SAT DEC 7 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE REGION THIS MORNING. THE FRONT WILL STALL
TO THE SOUTH INTO SUNDAY THEN LIFT BACK NORTH THROUGH THE AREA SUNDAY
NIGHT. A STRONGER COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND CROSS
EARLY TUESDAY. COOL HIGH PRESSURE WILL BUILD IN FROM THE WEST WEDNESDAY
THROUGH FRIDAY.
&&
.NEAR TERM /TODAY/...
AS OF 345 AM SATURDAY...PATCHY SHOWERS ARE INDICATED JUST
NORTHWEST OF OUR CWA. PER LATEST 3 KM HRRR AND RAP MODELS...BULK
OF THE PRECIPITATION WILL START TO ARRIVE IN OUR FAR NORTHWESTERN
COUNTIES BETWEEN 10Z AND 12Z. THIS PRECIPITATION WILL OCCUR BEHIND
STRONG COLD FRONT WHICH IS JUST NORTH AND WEST OF OUR CWA. THE
RAIN WILL OVERSPREAD THE AREA THROUGH THE MORNING AND CONTINUE
THROUGH THE DAY AND WILL HAVE LIKELY POPS EVERYWHERE. TEMPERATURES
SHOULD REACH THEIR MAXIMUM THIS MORNING THEN SLOWLY FALL THROUGH
THE DAY AS THE COLD FRONT WORKS ITS WAY OFFSHORE BY THE AFTERNOON.
PER LATEST WATER VAPOR SATELLITE...THIS SYSTEM CONTAINS MOSTLY
PACIFIC MOISTURE AND THINK THE QPF TOTAL WILL BE RATHER LIGHT...ON
THE ORDER OF ONE QUARTER INCH OF LESS FOR THE MOST PART. GUSTY
NORTH WINDS BEHIND THE FRONT WILL MAKE FOR A CHILLY WET AFTERNOON
ACROSS EASTERN NORTH CAROLINA FOLLOWING THE NEAR RECORD-WARMTH OF
THE PAST TWO DAYS.
&&
.SHORT TERM /TONIGHT/...
AS OF 350 AM SATURDAY...A STEADY LIGHT RAIN ACCOMPANIED BY GUSTY
NORTH WINDS WILL CONTINUE OVERNIGHT. MINIMUM TEMPERATURES TONIGHT
WILL RANGE FROM THE UPPER 30S TO LOWER 40S EXCEPT MID TO UPPER 40S
ALONG THE OUTER BANKS. WILL KEEP POPS IN THE LIKELY CATEGORY OVER
MOST OF THE AREA TONIGHT.
&&
.LONG TERM /SUNDAY THROUGH FRIDAY/...
AS OF 330 AM SAT...AN UPPER TROUGH WILL REMAIN CENTERED OVER THE
CENTRAL/WESTERN CONUS AS A STRONG RIDGE ALOFT REMAINS CENTERED
OVER FLORIDA AND THE SE CONUS...PLACING EASTERN NC IN SW FLOW
ALOFT THROUGH EARLY IN THE WEEK. A STRONG FRONTAL INVERSION WILL
BE PRESENT SUN AS WINDS JUST ALOFT REMAIN SW WITH STRONG NLY
SURFACE WINDS DUE TO HIGH PRESSURE AT THE SURFACE RIDGING SOUTH
OVER THE AREA FROM THE MID-ATLANTIC STATES. THIS WILL PRODUCE
WIDESPREAD RAIN AND LOW CLOUDS THROUGH SUN. COOLER TEMPS EXPECTED
ON SUN DUE TO CLOUDS/PRECIP WITH HIGHS STRUGGLING IN THE 40S
INLAND TO 50S ALONG THE COAST. LATEST GUIDANCE CONTINUES TO
INDICATE A COASTAL TROUGH DEVELOPING SUN AFTERNOON...WHICH BECOMES
A WEAK LOW THAT MOVES NNE ALONG THE NC COAST SUN NIGHT. AS THE LOW
MOVES NE OF THE AREA LATE SUN NIGHT/EARLY MON MORNING...COLD AIR
DAMMING SCENARIO WILL SHIFT NW OF THE REGION AS SW RETURN FLOW
TAKES OVER WITH EASTERN NC AGAIN IN THE WARM SECTOR. RAIN CHANCES
WILL END FROM SOUTH TO NORTH ACROSS E NC LATE SUN...WITH ONLY ISO
SHOWERS EXPECTED SUN NIGHT.
UPPER RIDGE WILL STRENGTHEN AGAIN MON WITH HIGH TEMPS EXPECTED
BACK INTO THE UPPER 60S TO LOWER 70S UNDER PARTLY SUNNY SKIES. LOW
LEVEL THICKNESSES BUILD TO THE 1375-1385 METER RANGE...BUT MIXED
CLOUDS MAY INHIBIT FULL INSOLATION SO HELD TEMPS IN THE LOW 70S TO
UPPER 60S...ALTHOUGH GREATER BREAKS IN CLOUD COVER COULD MEAN
TEMPS REACHING A FEW DEGREES HIGHER THAN CURRENTLY FORECAST.
ANOTHER COLD FRONT WILL PASS THROUGH EASTERN NC EARLY TUES MORNING
MEANING ANOTHER NON-DIURNAL TEMP REGIME EXPECTED WITH HIGHS BEING
REALIZED IN THE MORNING WITH TEMPS PLUNGING IN THE AFTERNOON. RAIN
EXPECTED ONCE AGAIN WITH THIS FRONTAL BOUNDARY AS PLENTY OF GULF
OF MEXICO MOISTURE IN SW FLOW ALOFT. BEST CHANCES WILL BE LATE MON
NIGHT ACROSS THE NORTH CWA TRANSITIONING TO THE REST OF THE AREA
TUES. MAINTAINED LIKELY POPS DUE TO STRONG AGREEMENT AMONGST OPER
MODEL RUNS BETWEEN GFS/ECMWF AND ECMWF ENSEMBLE MEAN. RAIN WILL
QUICKLY END BY TUES EVENING FROM NW TO SE AS THE FRONT SWEEPS
OFFSHORE. MUCH COOLER/DRIER AIR WILL FILTER IN BEHIND THE FRONT
WED/THURS WITH HIGHS IN THE UPPER 40S/LOW 50S WITH LOWS BELOW
FREEZING MOST AREAS INLAND. MODEST AGREEMENT THURS AFTERNOON WITH
A WEAK LOW DEVELOPING OFFSHORE OF SC/GA WHICH MAY WRAP AROUND SOME
MOISTURE INTO THE EASTERN HALF OF THE CWA...THUS ADDED SLIGHT
CHANCE POPS THURS. THE LOW WILL SHIFT WELL OFFSHORE THURS NIGHT
WITH A RETURN TO DRY CONDITIONS OVER THE AREA THROUGH FRI...WITH
TEMPS STILL 5-8 F BELOW NORMAL FOR MID DECEMBER.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SAT/...
AS OF 1 AM SATURDAY...VFR CONDITIONS CURRENTLY AT ALL OF THE TAF
SITES WITH PRECIPITATION NOT LIKELY TO ARRIVE UNTIL AFTER 12Z.
CEILINGS WILL LOWER TO IFR IN OCCASIONAL RAIN AND SHOULD REMAIN IN
THE IFR THROUGH SUNDAY MORNING. N WINDS WILL BE GUSTY AFTER
FRONTAL PASSAGE LATER THIS MORNING.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SAT...MODEL SOUNDINGS INDICATE A PROLONGED PERIOD OF
MVFR/IFR CONDITIONS THROUGH MUCH OF SUN...WITH WIDESPREAD RAIN. A
WEAK LOW OFF THE COAST WILL PUSH NE THROUGH THE AREA SUN NIGHT
WITH SW FLOW TAKING OVER AND PRECIP CHANCES DIMINISHING WITH LOWER
CIGS LIFTING N OF THE REGION SUN NIGHT INTO MON...THOUGH FOG MAY
BE A POSSIBILITY SUN NIGHT. ANOTHER COLD FRONT CROSS THE TERMINALS
FROM NW TO SE TUES WITH ANOTHER ROUND OF MVFR/IFR CONDITIONS
POSSIBLE IN LOWERED CEILINGS/VSBYS THROUGH TUES. HIGH PRESSURE
BUILDS OVER THE REGION TUES NIGHT THROUGH MID TO LATE WEEK WITH
VFR RETURNING IN MOSTLY SUNNY SKIES.
&&
.MARINE...
SHORT TERM /THROUGH SAT/...
AS OF 355 AM SATURDAY...SOUTHWEST WINDS ARE SLOWLY INCREASING INTO
THE 15 TO 20 KNOT RANGE EARLY THIS MORNING. AS THE COLD FRONT
SLOWLY CROSSES THE AREA BY EARLY AFTERNOON...EXPECT NORTHERLY
WINDS INCREASING TO 20 TO 25 KNOTS WITH 25 TO 30 KNOTS AT TIME NORTH
OF CAPE LOOKOUT. LOCAL NWPS/SWAN MODEL INDICATES SEAS AS HIGH AS 9
TO POSSIBLE 10 FEET LATER TODAY AND TONIGHT WITH THE GUSTY
NORTHERLY WINDS. GRADIENT SLACKENS A BIT BY LATE IN THE DAY SUNDAY
AS SURFACE LOW MOVES ALONG THE NOW OFFSHORE FRONTAL BOUNDARY.
LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 330 AM SAT...SCA CONDITIONS WILL PERSIST OVER THE WATERS
THROUGH SUN MORNING AS N SURGE OF 20-25 KT CONTINUES WITH SEAS
ELEVATED 5-7 FT. MODELS IN AGREEMENT WITH A WEAK INVERTED/COASTAL
TROUGH OVER THE SOUTHERN/CENTRAL WATERS SUN AFTERNOON WHICH
DEVELOPS INTO A WEAK SURFACE LOW AND MOVES NNE ALONG THE NC COAST
SUN NIGHT. SURFACE WINDS WILL BECOME SW ONCE THE WEAK LOW LIFTS
NORTH OF THE WATERS SUN NIGHT. WINDS AND SEAS SUBSIDE BELOW SCA
CRITERIA MON MORNING INTO TUES WITH SW WINDS 10-15 KT AND SEAS 3-5
FT. WINDS SHIFT NW/N AND INCREASE 15-20 KT DUE TO POST-FRONTAL CAA
SURGE ASSOCIATED WITH STRONG HIGH PRESSURE BUILDING OVER THE WATERS
TUES NIGHT INTO WED. SEAS BUILD 4-7 FT LATE TUES/TUES NIGHT. HIGH
PRESSURE BUILDS SE OVER THE WATERS WED WITH SEAS SUBSIDING BELOW 6
FT ALTHOUGH MAY SEE HIGHER SEAS LINGER FOR THE CENTRAL WATERS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 6 PM EST THIS
EVENING FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...CTC
NEAR TERM...CTC
SHORT TERM...CTC
LONG TERM...DAG
AVIATION...CTC/DAG
MARINE...CTC/DAG
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
103 AM EST SAT DEC 7 2013
.SYNOPSIS...
A COLD FRONT WILL APPROACH FROM THE NORTHWEST TONIGHT AND CROSS
THE REGION SATURDAY MORNING. THE FRONT WILL STALL TO THE SOUTH
INTO SUNDAY THEN LIFT BACK NORTH THROUGH THE AREA SUNDAY NIGHT.
A STRONGER COLD FRONT WILL APPROACH FROM THE WEST MONDAY AND CROSS
EARLY TUESDAY. HIGH PRESSURE WILL BUILD IN FROM THE WEST WEDNESDAY
THROUGH FRIDAY.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1255 AM SATURDAY...THE 3 KM HRRR AND RAP MODELS SHOW THE
BULK OF THE PRECIPITATION WILL NOT ARRIVE IN THE MHX CWA UNTIL
AFTER 10Z AND MOSTLY AFTER 12Z. HAVE DROPPED POPS OVER THE NEXT
FEW HOURS TO ACCOUNT FOR THIS DELAY. ANOTHER MILD NIGHT WITH TEMPS
IN THE 65 TO 70 DEGREE RANGE. TEMPERATURES SHOULD REMAIN FAIRLY
STEADY OVER THE NEXT FEW HOURS. COLD FRONT CURRENTLY IN THE
WESTERN PIEDMONT AND WILL ARRIVE IN OUR AREA BY DAYBREAK.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH 6 PM SUNDAY/...
AS OF 215 PM FRIDAY...COLD FRONT OVER NRN TIER EARLY WILL PUSH S
THRU THE REGION SATURDAY MORN. TEMPS WILL NOT FOLLOW TYPICAL
DIURNAL CURVE WITH HIGHS EARLY IN THE DAY WITH TEMPS LOWERING
WITH STRONG CAA IN WAKE OF FRONT. BY LATE AFTN TEMPS WILL BE IN
THE 40S N TO LOWER 50S FAR S. MDLS SIMILAR IN SHOWING DEEP
MOISTURE MAINLY WITH AND BEHIND COLD FRONT AND EXPECT WIDESPREAD
RAIN WITH LIKELY TO CATEGORICAL POPS. RAINFALL WILL NOT BE OVERLY
HEAVY WITH AROUND 1/4 INCH MOST SPOTS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
AS OF 330 PM FRI...UPPER TROUGH WILL REMAIN CENTERED OVER THE
CENTRAL/WESTERN CONUS AS A STRONG RIDGE ALOFT REMAINS CENTERED
OVER FLORIDA AND THE SE CONUS...PLACING EASTERN NC IN SW FLOW
ALOFT THROUGH EARLY IN THE WEEK. A STRONG FRONTAL INVERSION WILL
BE PRESENT SAT NIGHT THROUGH SUN AS WINDS JUST ALOFT REMAIN SW
WITH STRONG NLY SURFACE WINDS. THIS WILL PRODUCE WIDESPREAD RAIN
AND LOW CLOUDS THROUGH SUNDAY. COOLER TEMPS EXPECTED ON SUNDAY
DUE TO CLOUDS/PRECIP WITH HIGHS STRUGGLING IN THE 40S INLAND TO
50S ALONG THE COAST. LATEST GUIDANCE CONTINUES TO INDICATE A
COASTAL TROUGH DEVELOPING SUN AFTERNOON...WHICH BECOMES A WEAK LOW
THAT MOVES NNE ALONG THE NC COAST SUN NIGHT. AS THE LOW MOVES NE
OF THE AREA LATE SUN NIGHT/EARLY MON MORNING...COLD AIR DAMMING
SCENARIO WILL SHIFT NW OF THE REGION AS SW RETURN FLOW TAKES OVER
WITH EASTERN NC AGAIN IN THE WARM SECTOR. RAIN CHANCES WILL END
FROM SOUTH TO NORTH ACROSS E NC LATE SUN...WITH ONLY ISO SHOWERS
EXPECTED BY SUN NIGHT.
UPPER RIDGE WILL STRENGTHEN AGAIN MON WITH HIGH TEMPS EXPECTED
BACK INTO THE UPR 60S TO LOWER 70S UNDER PARTLY SUNNY SKIES. LOW
LEVEL THICKNESSES BUILD TO THE 1380 METER RANGE...BUT MIXED
CLOUDS MAY INHIBIT FULL INSOLATION SO HELD TEMPS IN THE LOW 70S
TO UPPER 60S...ALTHOUGH GREATER BREAKS IN CLOUD COVER COULD MEAN
TEMPS REACHING A FEW DEGREES HIGHER THAN CURRENTLY FORECAST.
ANOTHER COLD FRONT WILL PASS THROUGH EASTERN NC EARLY TUES
MORNING...MEANING ANOTHER NON-DIURNAL TEMP REGIME EXPECTED WITH
HIGHS BEING REALIZED IN THE MORNING WITH TEMPS PLUNGING IN THE
AFTERNOON. RAIN EXPECTED ONCE AGAIN WITH THIS FRONTAL BOUNDARY AS
PLENTY OF GOM MOISTURE WILL BE PRESENT WITH THE STRONG FORCING
EXPECTED. BEST CHANCES WILL BE LATE MON NIGHT ACROSS THE NORTH
TRANSITIONING TO THE REST OF THE FA TUE. HAVE INC POPS TO LIKELY
DUE TO STRONG AGREEMENT AMONGST OPERATIONAL RUNS BETWEEN GFS/ECM
AND ECM ENSEMBLE MEAN. RAIN WILL QUICKLY END BY TUE EVENING AS THE
FRONT SWEEPS OFFSHORE. MUCH COOLER/DRIER AIR WILL FILTER IN BEHIND
THE FRONT WITH HIGHS IN THE UPPER 40S/LOW 50S WED/THUR WITH LOWS
BELOW FREEZING MOST AREAS INLAND.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
SHORT TERM /THROUGH SAT/...
AS OF 1 AM SATURDAY...MVFR CEILINGS LIMITED TO KOAJ WITH VFR
ELSEWHERE CURRENTLY. PRECIPITATION NOT LIKELY TO ARRIVE UNTIL
AFTER 12Z. CEILINGS WILL LOWER TO IFR IN OCCASIONAL RAIN AND
SHOULD REMAIN IN THE IFR THROUGH SUNDAY MORNING. N WINDS WILL BE
GUSTY AFTER FRONTAL PASSAGE LATER THIS MORNING.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 PM FRI...MODEL SOUNDINGS INDICATE A PROLONGED PERIOD OF
MVFR/IFR CONDITIONS THROUGH MUCH OF SUNDAY...WITH WIDESPREAD RAIN
CONTINUING THROUGH SUN. A WEAK LOW OFF THE COAST WILL PUSH NE
THROUGH THE AREA SUN NIGHT WITH SW FLOW TAKING OVER AND PRECIP
CHANCES DIMINISHING WITH LOWER CIGS LIFTING N OF THE REGION...THOUGH
FOG MAY BE A POSSIBILITY SUN NIGHT. ANOTHER COLD FRONT CROSS THE
TERMINALS FROM NW TO SE TUES WITH ANOTHER ROUND OF MVFR/IFR
CONDITIONS POSSIBLE IN LOWERED CEILINGS/VSBYS THROUGH TUES. HIGH
PRESSURE BUILDS OVER THE REGION TUES NIGHT THROUGH MID TO LATE
WEEK WITH VFR RETURNING IN MO SUNNY SKIES.
&&
.MARINE...
SHORT TERM /THROUGH SAT/...
AS OF 1 AM SATURDAY...WINDS WILL CONTINUE TO SLOWLY INCREASE AHEAD
OF A STRONG COLD CURRENTLY OVER THE WESTERN PIEDMONT. SW WINDS ARE
CURRENTLY 15 TO 20 KNOTS OVER THE CENTRAL AND NORTHERN COASTAL
WATERS. SEAS CURRENTLY RANGE FROM 2 TO 4 FEET...BUT THE BUOY 30
MILES SE OF NEW RIVER HAS INCREASED TO 6 FEET AND EXPECT SEAS TO
GRADUALLY INCREASE TOWARD MORNING. AS NRLY WINDS INCREASE SAT
SEAS TO 8 FT OR SO EXPECTED OUTER CNTRL AND NRN WTRS BY AFTN.
LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 330 PM FRI...SCA CONDITIONS WILL PERSIST OVER THE WATERS
THROUGH THE WEEKEND AS N SURGE OF 20-25 KT CONTINUES THROUGH SUN
MORNING. SEAS SHOULD MAX OUT AT 6 TO 8 FT ACROSS THE NORTHERN
WATERS SAT NIGHT INTO SUN MORNING. MODELS IN AGREEMENT WITH A WEAK
INVERTED/COASTAL TROUGH OVER THE SOUTHERN/CENTRAL WATERS SUN
AFTERNOON WHICH DEVELOPS INTO A WEAK SURFACE LOW AND MOVES NNE
ALONG THE NC COAST SUN NIGHT. SURFACE WINDS WILL BECOME SW ONCE
THE WEAK LOW LIFTS NORTH OF THE WATERS SUN NIGHT. WINDS AND SEAS
BRIEFLY SUBSIDE BELOW SCA CRITERIA MON MORNING WITH SW WINDS 10-15
KT AND SEAS 3-5 FT...THEN INCREASE TO 15-20 KT AND SEAS 4-7 FT MON
NIGHT AS THE GRADIENT TIGHTENS BETWEEN SURFACE RIDGE OFF THE
SOUTHEASTERN COAST AND A COLD FRONT APPROACHING FROM THE NW. COLD
FRONT WILL PASS THROUGH THE WATERS TUE WITH WINDS TURNING SHARPLY
NORTHERLY WITH SPEEDS 15 TO 20 KT WITH HIGHER GUSTS. SEAS WILL
BUILD TO 5 TO 7 FEET WITH THE STRONG CAA.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SUNDAY FOR AMZ135.
SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 6 PM EST THIS
EVENING FOR AMZ130.
SMALL CRAFT ADVISORY UNTIL 7 PM EST SUNDAY FOR AMZ150-152-154.
SMALL CRAFT ADVISORY UNTIL 1 PM EST SUNDAY FOR AMZ156-158.
&&
$$
SYNOPSIS...RF
NEAR TERM...CTC
SHORT TERM...RF
LONG TERM...TL
AVIATION...JAC/CTC/TL
MARINE...CTC/TL/LEP
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1153 PM CST FRI DEC 6 2013
.UPDATE...
ISSUED AT 1153 PM CST FRI DEC 6 2013
EXPANDED THE WIND CHILL WARNING TO INCLUDE THE SOUTHWEST WHICH WAS
PREVIOUSLY IN A WIND CHILL ADVISORY. 05-06 UTC OBSERVATIONS
INDICATE WIND CHILLS TO 45 BELOW ARE OCCURRING ACROSS THE
SOUTHWEST...AND ARE FORECAST TO CONTINUE INTO SATURDAY MORNING.
UPDATE ISSUED AT 944 PM CST FRI DEC 6 2013
UPDATE FOR TEMPERATURE TRENDS AND SKY COVER. A BATCH OF STRATUS
HAS EXPANDED AND DRIFTED SOUTH INTO NORTHERN NORTH DAKOTA. THIS
AREA IS MODELED WELL BY THE 13KM RAP AND PERSISTS OVERNIGHT BEFORE
SCATTERING OUT SATURDAY MORNING.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 239 PM CST FRI DEC 6 2013
ARCTIC AIR FIRMLY IN PLACE TODAY THROUGH SATURDAY AS TEMPERATURES
REMAIN BELOW ZERO ACROSS THE WEST AND CENTRAL. DIMINISHED WINDS
DEEP SNOW COVER AND AND THE CENTER OF THE ARCTIC HIGH MOVING
THROUGH SOUTHWEST NORTH DAKOTA TONIGHT SHOULD ALLOW OVERNIGHT LOWS
TO FALL INTO THE 20S BELOW ZERO. EVEN A MODEST AMOUNT OF WIND WILL
RESULT IN WIND CHILLS COLDER THAN 40 BELOW ACROSS THE NORTH
C=SOUTH CENTRAL AND EAST. ISSUED A WIND CHILL WARNING MAINLY ALONG
AND NORTH AND EAST OF LAKE SAKAKAWEA AND THE MISSOURI RIVER
VALLEY. SOME CLOUDS...AND LIGHTER WINDS ACROSS THE SOUTHWEST SHOULD
HOLD THE WIND CHILLS IN THE ADVISORY CATEGORY. THERE WILL PROBABLY
BE FURTHER ADVISORIES SATURDAY NIGHT INTO SUNDAY...ESPECIALLY
NORTH. WILL CONCENTRATE TO ION THE MOST HAZARDOUS ASPECTS OF THE
ARCTIC AIR TONIGHT AND SATURDAY FIRST.
.LONG TERM...(SATURDAY NIGHT THROUGH FRIDAY)
ISSUED AT 239 PM CST FRI DEC 6 2013
THE LONG TERM BEGINS WITH A BRIEF PHASING OF THE NORTHERN/SOUTHERN
STREAMS SUNDAY...FOLLOWED BY THE NORTHERN STREAM TAKING FIRM CONTROL
AGAIN MONDAY THROUGH WEDNESDAY. FOR THURSDAY AND FRIDAY...A NEAR
ZONAL FLOW IS EXPECTED AS THE COLDEST OF THE ARCTIC AIR RETREATS
NORTH.
FOR SATURDAY NIGHT AND SUNDAY...CLOUDS WILL THICKEN AND LOWER ACROSS
THE SOUTH SATURDAY NIGHT WITH LIGHT SNOW FORECAST TO DEVELOP ALONG
AN INVERTED SURFACE TROUGH WHICH EXTENDS FROM COLORADO INTO
SOUTHERN NORTH DAKOTA. QPF AMOUNTS REMAIN LIGHT WITH A COUPLE
HUNDREDTHS. WITH SNOW RATIOS AT 20 TO 1...EXPECT THE POTENTIAL FOR
AROUND A HALF INCH OF SNOW...ALONG AND SOUTH OF INTERSTATE 94
THROUGH SUNDAY AFTERNOON. THE NORTH WILL REMAIN DRY BUT VERY COLD.
EXPECTING A WIND CHILL HEADLINE/ADVISORY FOR THE NORTH INTO SUNDAY
MORNING. THE CENTRAL AND SOUTH WILL BE UNDER THE INFLUENCE OF CLOUDS
AND INCREASING POTENTIAL FOR LIGHT SNOW...THUS WILL NOT SEE WIND
CHILL CRITERIA BEING MET CENTRAL AND SOUTH FOR SATURDAY NIGHT INTO
SUNDAY MORNING.
FOR SUNDAY NIGHT...DRY BUT VERY COLD WITH WIND CHILL VALUES BETWEEN
25 AND 39 BELOW ZERO...WHICH WILL LIKELY NECESSITATE ANOTHER WIND
CHILL ADVISORY FOR ALL OF WESTERN AND CENTRAL NORTH DAKOTA.
FOR MONDAY INTO MONDAY NIGHT...AN ALBERTA CLIPPER REMAINS POISED TO
SWEEP THROUGH MONDAY AFTERNOON INTO MONDAY NIGHT. STRONG H85 WINDS
OF 50KT WILL ACCOMPANY THE CLIPPER. HOW MUCH OF THIS MOMENTUM WILL
TRANSLATE TO THE SURFACE IS STILL UNKNOWN. GFS SOUNDINGS INDICATE AN
ISOTHERMAL LAYER JUST ABOVE THE SURFACE...AND AN ADIABATIC LAPSE
RATE IS NOT SEEN UNTIL FARTHER UP IN THE SOUNDING. THUS THERE MAY BE
A DISCONNECT WITH LINKING UP TO THESE STRONGEST WINDS. CONCUR WE
WILL HAVE WINDS BETWEEN 20 AND 35 MPH WITH GUSTS TO 40 MPH...WHICH
WILL PRODUCE BLOWING AND DRIFTING SNOW...BUT NOT READY TO GO WITH
ANYTHING MUCH HIGHER THAN THAT AT THIS TIME. HAVE COLLABORATED WITH
NEIGHBORING OFFICES AND INCREASED WINDS BUY 5KT OVER THE ALLBLEND.
WILL AWAIT FUTURE RUNS BEFORE MAKING ANY OTHER CHANGES. DO EXPECT
LIGHT SNOW TO DEVELOP IN THE MORNING ACROSS THE NORTHWEST AND THEN
SPREAD SOUTHEAST IN THE AFTERNOON/EVENING. BLOWING/DRIFTING SNOW
WILL COMMENCE MONDAY AFTERNOON THROUGH MONDAY NIGHT. A SPECIAL
WEATHER STATEMENT OR POSSIBLE WINTER WEATHER ADVISORY MAY BE NEEDED
IN THE NEXT DAY OR TWO. THE LIGHT SNOW WILL DIMINISH MONDAY NIGHT.
NEW SNOWFALL ACCUMULATIONS SHOULD RANGE FROM A HALF INCH UP TO ONE
INCH MONDAY INTO MONDAY NIGHT. IN ADDITION...WE WILL LIKELY NEED WIND
CHILL HEADLINES LATE MONDAY NIGHT INTO TUESDAY MORNING FOR THE NORTH
AND EXTENDING INTO THE JAMES RIVER VALLEY WITH READINGS BETWEEN 25
AND 35 BELOW ZERO.
FOR TUESDAY AND WEDNESDAY...NORTHWEST FLOW ALOFT WITH A 1040MB
SURFACE HIGH WILL SLIDE ACROSS NORTH DAKOTA. GENERALLY A DRY AND
COLD PATTERN DURING THIS TIME. WIND CHILL TEMPERATURES OF 25 TO 35
BELOW ZERO ARE FORECAST ACROSS THE NORTH...AND INTO THE JAMES RIVER
VALLEY.
FOR THURSDAY AND FRIDAY...WARM AIR ADVECTION PROCESSES WILL ALLOW FOR THE
POTENTIAL OF LIGHT SNOW MAINLY ACROSS THE NORTH AND INTO THE TURTLE
MOUNTAINS THURSDAY. HIGH TEMPERATURES THURSDAY WILL RANGE BETWEEN 15
AND 28 DEGREES ABOVE ZERO THURSDAY. HOWEVER THIS WILL BE SHORT LIVED
AS ANOTHER SURGE OF COLD AIR ADVECTION FRIDAY...WITH HIGHS FORECAST
FROM ZERO TO 15 ABOVE. NORTHWEST FLOW FRIDAY MAY ALLOW ANOTHER
SYSTEM TO PRODUCE A CHANCE OF SNOW FRIDAY INTO FRIDAY NIGHT. THE GFS
AND ALLBLEND BOTH ADVERTISE THIS...BUT THE ECMWF IS DRY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1153 PM CST FRI DEC 6 2013
AN AREA OF MVFR STRATUS IS DRIFTING SOUTH AND WILL IMPACT KMOT AND
POSSIBLY KISN OVERNIGHT. VERY LIGHT SNOW IS POSSIBLE UNDER THIS
DECK. OTHERWISE...VFR CONDITIONS AT OTHER TAF SITES THROUGH 06 UTC
SATURDAY. LIGHT SNOW POSSIBLE AT KBIS AND KJMS POST 06 UTC.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WIND CHILL WARNING UNTIL 1 PM CST /NOON MST/ SATURDAY FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...AYD
SHORT TERM...WAA
LONG TERM...KS
AVIATION...AYD
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
844 PM CST SUN DEC 8 2013
.DISCUSSION...02 SURFACE ANALYSIS PLACES A WEAK QUASI-STATIONARY
BOUNDARY/SURFACE LOW NEAR THE LOUISIANA/MISSISSIPPI/ALABAMA GULF
COAST THIS EVENING. MEANWHILE...A RIDGE OF HIGH PRESSURE IS
LOCATED ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY INTO
PORTIONS OF THE MID SOUTH. TEMPERATURES AS OF 8 PM CST RANGE FROM
THE MIDDLE 30S TO AROUND 40 DEGREES ACROSS WEST TENNESSEE NEAR THE
TENNESSEE RIVER AND PORTIONS OF NORTHEAST MISSISSIPPI AND UPPER
20S TO LOWER 30S ALONG AND WEST OF THE MISSISSIPPI RIVER.
KNQA/KGWX WSR-88D RADAR TRENDS INDICATE LIGHT RAIN SHOWERS ACROSS
NORTHEAST MISSISSIPPI IN ASSOCIATION WITH A MID LEVEL SHORTWAVE
TROUGH AND AN UPPER LEVEL JET STREAK MOVING ACROSS THE REGION.
LATEST RUC SHORT TERM MODEL SEEMS TO BE HANDLING CURRENT TRENDS
THE BEST WITH RESPECT TO PRECIPITATION. WILL MAKE ADJUSTMENTS TO
LIMIT AND LOWER PRECIPITATION CHANCES OVERNIGHT TO EXTREME
NORTHEAST MISSISSIPPI.
AS OF 8 PM CST...VISIBILITIES ARE CURRENTLY RANGING FROM 4SM TO
P6SM. LIGHT WINDS HAVE KEPT LOW LEVEL MOISTURE LIFTED AS A LOW
STRATUS LAYER THUS FAR. WILL CONTINUE TO MONITOR SHORT TERM TRENDS
FOR THE POSSIBLE DEVELOPMENT OF FOG/FREEZING FOG AND ANY HEADLINES
IF IT BECOMES NECESSARY.
WILL ALSO MAKE MINOR ADJUSTMENTS TO TEMPERATURES AND ALL OTHER
ELEMENTS AS NEEDED TO ACCOUNT FOR LATEST TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
&&
.PREV DISCUSSION... /ISSUED 536 PM CST SUN DEC 8 2013/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 320 PM CST SUN DEC 8 2013/
A SHARP TEMPERATURE GRADIENT IS OCCURRING ACROSS THE MIDSOUTH
THIS EVENING. LOCATIONS SOUTH AND EAST OF A MEMPHIS TO JACKSON
TENNESSEE LINE ARE REPORTING TEMPERATURES IN THE MID 30S TO LOWER
40S. NORTH AND WEST OF THIS LINE TEMPERATURES RANGE FROM 28-32
DEGREES. TEMPERATURES ALSO REMAIN NEAR FREEZING FARTHER SOUTH IN
THE DELTA SUCH AS MARIANNA...TUNICA AND CLARKSDALE. PATCHY DENSE
FREEZING FOG HAS FORMED ALONG THIS GRADIENT BETWEEN THE ARCTIC AIR
AND THE WARMER AIR. WEST
MEMPHIS...MILLINGTON...BLYTHEVILLE...DYERSBURG AND UNION CITY ARE
REPORTING VISIBILITIES FROM A QUARTER MILE TO THREE QUARTERS OF A
MILE. THUS FAR NO ICING HAS OCCURRED AS A RESULT OF THE FOG BUT A
LITTLE WORRIED THAT THIS MAY CHANGE ONCE THE SUN GOES DOWN. WILL
LET EVENING SHIFT MONITOR FOR ANY POTENTIAL ADVISORIES.
MEANWHILE...RAIN CONTINUES TO PUSH NORTHWARD INTO NORTH
MISSISSIPPI WHERE LOCATIONS ARE ABOVE FREEZING. THIS IS DUE TO A
SFC LOW DEVELOPING ALONG A STATIONARY FRONT NEAR THE GULF COAST.
MODELS INDICATE THE NORTHERN EXTENT OF THE PRECIPITATION COULD
REACH INTO LOCATIONS THIS EVENING THAT ARE SITTING JUST ABOVE OR
AT FREEZING CURRENTLY. AS TEMPERATURES DROP THIS EVENING THIS
COULD CHANGE RAIN OVER TO FREEZING RAIN...BUT CONFIDENCE IS LOW
THUS AGAIN WILL LET EVENING SHIFT MONITOR FOR ANY POTENTIAL
ADVISORIES. WILL JUST MENTION A SLIGHT CHANCE OR CHANCE OF
FREEZING RAIN IN THE FORECAST AS BEST CHANCES OF PRECIPITATION
WILL OCCUR ACROSS NORTHEAST MISSISSIPPI WHERE LOCATIONS WILL
REMAIN ABOVE FREEZING.
ANOTHER SFC LOW WILL DEVELOP ALONG THE STATIONARY FRONT LOCATED
ALONG THE GULF COAST BY MONDAY EVENING. THIS WILL BRING ANOTHER
ROUND OF PRECIPITATION THAT WILL SKIRT NORTHEAST MISSISSIPPI.
HOWEVER BY MONDAY EVENING...NORTHWEST WINDS WILL HAVE PUSHED
ARCTIC AIR FURTHER SOUTH AND EAST THUS PRECIPITATION COULD FALL IN
THE FORM OF FREEZING RAIN IF PRECIPITATION MAKES IT AS FAR NORTH
AS NORTHEAST MISSISSIPPI. STAY TUNED.
IN ADDITION...A SHORTWAVE WILL SWING ACROSS SOUTHERN MISSOURI AND
WESTERN KENTUCKY MONDAY NIGHT. THIS COULD BRING A BRIEF SHOT OF LIGHT
SNOW ACROSS PORTIONS OF NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL
AND NORTHWEST TENNESSEE. ANY ACCUMULATIONS THAT WOULD OCCUR WOULD
BE LESS THAN AN INCH.
BY TUESDAY...ARCTIC HIGH PRESSURE SETTLES OVER THE MIDSOUTH.
EXPECT DRY CONDITIONS WITH HIGHS RANGING FROM THE LOWER 30S TO
LOWER 40S. A REINFORCING SHOT OF ARCTIC AIR WILL MOVE INTO THE
AREA ON WEDNESDAY INTO WEDNESDAY NIGHT. LOWS WEDNESDAY NIGHT WILL
RANGE FROM THE MID TEENS TO THE MID 20S.
BY THURSDAY NIGHT...THE HIGH WILL SHIFT EAST TURNING WINDS AROUND TO
THE SOUTH. THE NEXT LOW PRESSURE SYSTEM WILL MOVE INTO THE AREA ON
FRIDAY AND WILL BRING CHANCES FOR PRECIPITATION TO THE MIDSOUTH
OVER THE NEXT WEEKEND. HOW QUICKLY THE ARCTIC AIR DEPARTS WILL
DEPEND ON POSSIBLY PRECIPITATION TYPE FOR PORTIONS OF NEXT
WEEKEND. THE 12Z ECMWF IS COLDER THAN THE 12Z GFS. FOR NOW HAVE
TRIED TO GO WITH AN IN BETWEEN SOLUTION WHICH WOULD HAVE
TEMPERATURES NEAR NORMAL AND WOULD KEEP PRECIPITATION IN THE FORM
OF RAIN.
KRM
&&
.AVIATION...
00Z TAF CYCLE
VIS HAS IMPROVED TO MVFR LEVELS AT ALL SITES BUT CIGS REMAIN IFR.
FEEL LIKE THOSE CIGS WILL CONTINUE MOST OF THE NIGHT POSSIBLY EVEN
LOWERING TO LIFR LEVELS FOR BRIEF PERIODS OF TIME. INCLUDED TEMPO
1-200 FOOT CIGS ALONG WITH 1SM BR AT TUP MKL AND MEM FOR BRIEF
PERIODS THIS EVENING/TONIGHT. SOME MARGINAL IMPROVEMENT TO CIGS IS
EXPECTED BY SUNRISE...BUT NOT ABOVE IFR LEVELS UNTIL AFTER
SUNRISE. GUIDANCE WANTS TO CONTINUE TO LIFT CIGS THROUGH THE DAY
EVEN TO VFR LEVELS...BASED ON EXPERIENCE...FEEL LIKE CLOUDS WILL
LINGER LONGER THAN GUIDANCE SUGGESTS...BUT WILL BRING LEVELS TO
5KFT DURING THE AFTERNOON FOR ALL LOCATIONS EXCEPT TUP. MAY
ACCOMPANY
RAIN AT TUP WILL BE LIGHT...WITH LITTLE TO NO PRECIPITATION
ELSEWHERE. WINDS GENERALLY LIGHT OVERNIGHT...LIGHT FROM THE NORTH
TOMORROW.
JDS
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 28 39 27 38 / 40 10 20 10
MKL 29 38 24 37 / 50 10 20 10
JBR 24 31 24 32 / 10 10 20 10
TUP 36 43 33 42 / 80 30 60 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
922 PM CST SUN DEC 8 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 856 PM CST SUN DEC 8 2013
CANCELLED WINTER WX ADVISORY FOR NORTHWEST PORTION OF FORECAST
AREA AS HAVE HAD GENERALLY LESS THAN AN INCH UP THERE WITH VSBYS
REMAINING IN THE 3 TO 5 MILES RANGE. EXPECT TO SEE AN INCH OR LESS
ADDITONAL ACCUMULATION OVERNIGHT THERE.
AREA OF LIGHT SNOW OVER FOX VALLEY LATE THIS EVENING ASSOCIATED
WITH SHORTWAVE DISTURBANCE MOVING ACROSS SOUTHEAST WISCONSIN.
VSBYS GENERALLY AROUND 2 MILES WITH SNOWFALL RATES A BIT HIGHER
ALONG THE LAKESHORE AS LAKE ENHANCEMENT CONTINUES THERE. VSBYS
FROM KEWAUNEE TO SOUTHEAST BROWN COUNTY...TO EAST OF OSHKOSH
BEWTEEN 1 AND 2 MILES. BACK/WESTERN EDGE OF THIS AREA OF LIGHT
SNOW APPROACHING THE FOX VALLEY THUS EXPECT LIGHT SNOW TO TAPER
OFF FROM SOUTHWEST TO NORTHEAST OVER THE NEXT FEW HOURS...EXCEPT
FOR THE LAKESHORE COUNTIES.
UPSTREAM SHORTWAVE MOVING ACROSS IOWA CONTINUED TO LOOK UNIMPRESSIVE
AS IT APPROACHES THE FORECAST AREA. DO NOT FEEL THIS FEATURE WILL
BE ABLE TO DO MUCH TO FURTHER ENHANCE LIGHT SNOW OVER THE FORECAST
AREA AFTER MIDNIGHT. LATEST RUC...NAM AND HRRR ARE ALL SUGGEST
WEAK LIFT AND VERY MINIMAL QPF AMOUNTS. WILL KEEP ADVISORY GOING
FOR NOW GIVEN LIGHT SNOW STILL FALLING OVER MUCH OF THE FORECAST
AREA. MAY TRIM ADDITIONAL COUNTIES TO THE WEST OF THE FOX VALLEY
FROM ADVISORY BEFORE MIDNIGHT IF RADAR RETURNS AND OBSERVED VSBYS
REMAIN LACKLUSTER.
HIGHEST SNOWFALL AMOUNTS HAVE GENERALLY BEEN AROUND 3 INCHES ALONG
THE LAKESHORE FROM MANITOWOC TO DOOR COUNTY. ABOUT 2 INCHES AT
NWS GREEN BAY AS OF 845 PM. JUST RECEIVED A REPORT OF 1.8 INCHES
SO FAR IN EAST GREEN BAY.
UPDATE
ISSUED AT 644 PM CST SUN DEC 8 2013
SYSTEM AFFECTING THE FORECAST AREA HAS BEEN RATHER DISORGANIZED
AND DISJOINTED THUS FAR. SO FAR...SNOWFALL AMOUNTS HAVE BEEN
AROUND AN INCH OR SO THROUGH 6 PM. HOWEVER...WATER VAPOR IMAGERY
SHOWS SOMEWHAT MORE ROBUST SHORTWAVE DISTURBANCE ENTERING
SOUTHWEST WISCONSIN. THIS FEATURE HAS HELPED TO CREATE A SOMEWHAT
MORE SOLID AND ORGANIZED AREA OF LIGHT SNOW ACROSS SOUTHEAST
WISCONSIN WITH VSBYS GENERALLY BETWEEN ABOUT 1 AND 2 MILES. THIS
AREA OF LIGHT SNOW CONTINUES TO DRIFT NORTHEAST AND WILL LIKELY CLIP
THE SOUTHEAST PORTION OF THE FOX VALLEY GENERALLY SOUTH OF A LINE
FROM OSH TO KEWAUNEE OVER THE NEXT FEW HOURS.
FURTHER AS ANTICIPATED...AN AREA OF LAKE ENHANCED SNOW CONTINUES
TO DEVELOP OVER CENTRAL LAKE MICHIGAN AND IS DRIFTING NORTHWEST.
RADAR REFLECTIVITIES HAVE BEEN GRADUALLY INCREASING AND EXPNADING
IN AREA COVERAGE OVER THE LAST HOUR. APPEARS ACTIVITY AHEAD OF
APPROACHING SHORTWAVE ENTERING SOUTHWEST WISCONSIN CONTRIBUTING TO
LES ENHANCEMENT OVER CENTRAL LAKE MICHIGAN VIA SEEDER-FEEDER
MECHANISM.
THUS...EXPECT TO SEE SOMEWHAT HIGHER SNOWFALL RATES ACROSS THE
FOX VALLEY THIS EVENING IN ASSOCIATION WITH SHORTWAVE MOVING
ACROSS SOUTHEAST WISCONSIN AND LAKE ENHANCEMENT OFF LAKE MICHIGAN.
COULD SEE ANOTHER INCH OR PERHAPS TWO MY MIDNIGHT ESPECIALLY
SOUTHEAST OFF A LINE FROM STURGEON BAY TO GREEN BAY TO OSHKOSH.
LOOKING FURTHER UPSTREAM...PRIMARY SHORTWAVE DISTURBANCE NOW
ENTERING NORTHWEST IOWA. THIS FEATURE IS ALSO FORECAST TO MOVE
ACROSS THE SOUTHERN WISCONSIN AFTER MIDNIGHT AND MAY HELP TO KEEP
SOME LIGHT SNOW GOING AFTER MIDNIGHT ESPECIALLY OVER THE
SOUTHEAST HALF OF THE FORECAST AREA. HOWEVER...LOOKING AT SURFACE
OBSERVATIONS OVER IOWA...VSBYS NOT VERY LOW AND WERE IN THE 2 TO 4
MILE RANGE. IN FACT THE LATEST HRRR AND RUC FORECASTS SEEM TO
SIGNIFICANTLY DISSOLVE THE AREA OF QPF AS THIS FEATURE APPROACHES
WISCONSIN.
FORCING ACROSS THE NORTHWEST THIRD OF THE FORECAST AREA NOT
EXPECTED TO BE VERY STRONG AND THUS FAR SNOWFALL RATES UP THERE
HAVE BEEN QUITE LIGHT WITH VSBYS GENERALLY IN THE 2 TO 4 MILE
RANGE. WILL SEE HOW THE SHORTWAVE MOVING OUT OF IOWA EVOLVES LATER
THIS EVENING...BUT IF CURRENT TRENDS CONTINUE MAY NEED TO CANCEL ADVISORY
UP THERE.
FOR NOW WILL KEEP ADVISORY GOING OVER ENTIRE FORECAST AREA AND
WILL REVIST A BIT LATER THIS EVENING. BOTTOM LINE IS IT APPEARS
MOST SIGNIFICANT SNOWFALL WILL BE FOCUSED OVER THE FOX VALLEY AND
LAKESHORE. APPEARS FINAL SNOWFALL TOTALS WILL BE ON THE LOW END OF
CURRENT FORECAST.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ONE SHORTWAVE
TROUGH MOVING INTO SOUTHWEST WISCONSIN THIS AFTERNOON...WHILE
ANOTHER WAVE NOW ENTERING THE CENTRAL GREAT PLAINS. AHEAD OF THE
FORMER SHORTWAVE...WEAK ISENTROPIC ASCENT IS PRODUCING A WIDESPREAD
SWATH OF LIGHT SNOW ACROSS THE STATE. THE BETTER SNOWS WITH THE
FIRST WAVE ARE STILL ACROSS IOWA AT THE MOMENT...WHERE VSBYS ARE
DOWN TO A HALF MILE AND WIDESPREAD 1-2 INCHES ARE BEING REPORTED SO
FAR. FURTHER CONCERNS RESIDE ALONG THE LAKE SHORE WHERE LAKE
ENHANCEMENT IS OCCURRING OVER CENTRAL AND SOUTHERN PARTS OF THE LAKE
MICHIGAN SHORELINE. EARLIER REPORTS SHOWED 1-1.5 INCH PER HOUR
SNOWFALL RATES IN THOSE LAKE ENHANCED BANDS. ONE OF THESE BANDS IS
APPROACHING MANITOWOC...BUT APPEARS TRANSIENT IN A LOW LEVEL
CONVERGENT ZONE. LOW LEVEL WINDS ARE JUST STARTING TO TURN TO THE
SOUTHEAST SO WILL NEED TO WATCH THESE TRENDS FOR THE REST OF THE
AFTERNOON. AS THE SHORTWAVES MOVE ACROSS THE ARE TONIGHT...SNOWFALL
AMOUNTS AND IMPACTS ARE THE MAIN FORECAST CONCERN.
TONIGHT...SHORTWAVE TROUGH OVER COLORADO WILL QUICKLY EJECT
NORTHEAST A DRIVE A STRENGTHENING...ALTHOUGH STILL RELATIVELY
WEAK...AREA OF LOW PRESSURE FROM THE CENTRAL GREAT PLAINS AND ACROSS
SOUTHEAST WISCONSIN TONIGHT. FORCING AHEAD OF THE SHORTWAVE IN THE
FORM OF -DIVQ...UPPER DIVERGENCE...AND ISENTROPIC ASCENT IS ONLY
MODEST...BUT BUFKIT SOUNDINGS FROM THE NAM/GFS/SREF ALL INDICATE A
150-200MB DEEP DENDRITIC GROWTH ZONE BETWEEN APPROX 850-650MB OVER
CENTRAL AND NORTHEAST WISCONSIN. THIS SUGGESTS THAT WHATEVER WEAK
TO MODERATE LIFT THAT OCCURS...SNOW FLAKE PRODUCTION WILL BE VERY
EFFICIENT AND SNOW TO LIQUID RATIOS WILL BE QUITE HIGH. GENERALLY
WENT WITH A 19-20:1 RATIO...ALTHOUGH A LITTLE LOWER NEAR THE LAKE
MICHIGAN SHORELINE WHERE ONSHORE FLOW WILL LEAD TO SLIGHTLY WARMER
LOW LEVEL THERMAL PROFILES. THE BULK OF THE SNOW LOOKS TO OCCUR IN
A COUPLE WAVES. THE FIRST WILL ARRIVE LATE THIS AFTERNOON INTO EARLY
THIS EVENING FROM THE FIRST AREA OF SNOW OVER IOWA AND SE
MINNESOTA...FOLLOW BY THE MAIN SHORTWAVE AND SURFACE LOW OVER
COLORADO. PLENTY OF 1-3" INCH REPORTS UPSTREAM OVER IOWA...AND FEW
4-6 INCH REPORTS OVER EASTERN NEBRASKA AS WELL. WILL INCREASE
AMOUNTS A LITTLE OVER N-C WISCONSIN TO AROUND 3 INCHES. THE PRIMARY
CONCERN THOUGH WILL BE ALONG THE LAKE SHORE WHERE WINDS WILL BE
TURNING TO THE EAST AND SOUTHEAST THIS EVENING. THE LAKE ENHANCEMENT
OVER SOUTHEAST WISCONSIN APPEARS TO BE FLUCTUATING...AS A CONVERGENT
BAND LIFTS NORTH. BUT EARLIER SNOWFALL RATES WHERE ENHANCEMENT TOOK
PLACE ARE ALARMING. LOOKS LIKE A GOOD 9-12 HOURS OF ENHANCEMENT
POSSIBLE OVER NORTHEAST WISCONSIN. WILL GO WITH WIDESPREAD 2-4
INCHES EXCEPT NEAR THE LAKESHORE WHERE 5-6 INCHES WILL BE POSSIBLE.
HEADLINES WILL REMAIN THE SAME...AND WILL PASS ALONG LAKE
ENHANCEMENT CONCERNS TO THE EVENING SHIFT.
MONDAY...THE SNOW WILL BE ENDING EARLY MONDAY MORNING OVER NORTHEAST
WISCONSIN AS THE SURFACE LOW PULLS AWAY. WEST WINDS WILL BE
STRENGTHENING IN THE WAKE OF THE LOW AND COLD ADVECTING AT THE SAME
TIME. TEMPS WILL REMAIN NEARLY STEADY OR FALL SLIGHTLY DURING THE
DAY...DESPITE CLEARING TAKING PLACE. WITH WINDS GUSTING TO 30
MPH...APPARENT TEMPS WILL BE FALLING TO NEAR 20 BELOW ZERO OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN DURING THE AFTERNOON. WILL
LIKELY NEED WIND CHILL HEADLINES...BUT WITH THE ONGOING SNOW
ADVISORY...WILL NOT ISSUE ANOTHER HEADLINE. MORNING TO MIDDAY HIGHS
IN THE MIDDLE SINGLE DIGITS NORTH TO THE UPPER TEENS NEAR THE LAKE
SHORE.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
VERY COLD AIR WILL REMAIN FIRMLY ENTRENCHED ACROSS THE AREA
MONDAY NIGHT. EXPECT WINDS CHILLS TO DROP TO AROUND 25 BELOW
ACROSS THE NORTH. HOWEVER...TEMPERATURES ARE EXPECTED TO
MODIFY SOME LATE MONDAY NIGHT DUE TO INCREASING CLOUDINESS
AND AHEAD OF APPROACHING SYSTEM. INCREASED CHANCES OF SNOW
ACROSS THE NORTHWEST HALF OF THE FORECAST AREA. INCREASED SNOW
CHANCES SIGNIFICANTLY ON TUESDAY MORNING AS SYSTEM MOVES ACROSS
THE AREA. ALSO...PRECIPITATION TOTALS WILL BE LIGHT...SNOW RATIOS
WOULD SUGGEST LESS THAN AN INCH OF NEW SNOW TUESDAY MORNING. THE
HIGHEST SNOWFALL TOTALS WILL BE ACROSS THE NORTH.
MOST OF THE MODELS NOW BRING CLIPPER SYSTEM SOUTH OF THE AREA
TUESDAY NIGHT. THE ONLY EXCEPTION WAS THE ECMWF...THUS WILL CONTINUE
CHANCES ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. THE GFS MODELS
HAS BEEN WAFFLING ON NORTHWARD EXTENT OF THE PRECIPITATION FIELD. VERY
COLD AIR IS EXPECTED WEDNESDAY MORNING. ANOTHER SYSTEM EXPECTED TO
PASS ACROSS THE NORTH THURSDAY/THURSDAY NIGHT. LOW CONFIDENCE ON WHEN
THIS SYSTEM WOULD BRING A SMALL CHANCE OF LIGHT SNOW DURING THIS PERIOD.
CURRENT FORECAST HAS LIGHT SNOW IN THE FORECAST THURSDAY NIGHT...BUT
LATER SHIFTS MAY NEED TO SPEED UP THE SNOW AND ADD A CHANCE TO THE
THURSDAY PERIOD. THE ARCTIC AIR WILL MODIFY FRIDAY INTO NEXT WEEKEND
WITH HIGHS IN THE UPPER TEENS TO MIDDLE 20S.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 608 PM CST SUN DEC 8 2013
WEAK LOW PRESSURE WILL MOVE NORTHEAST ACROSS SOUTHERN
WISCONSIN INTO LOWER MICHIGAN OVERNIGHT BRINGING LIGHT SNOW TO THE
AREA. SYSTEM OVERALL IS SOMEWHAT DISJOINTED AND DISORGANIZED THUS
SNOWFALL RATES NOT VERY IMPRESSIVE SO FAR THIS EVENING. MAINLY
MVFR CIGS AND VSBYS CAN BE EXPECTED THROUGH 06Z AT CENTRAL AND
NORTHERN WISCONSIN TAFS SITES. SOMEWHAT STRONGER UPPER-LEVEL
FORCING OVER SOUTHEAST WISCONSIN HAS HELPED TO GENERATE SOMEWHAT
MORE ORGANIZED AREA OF LIGHT SNOW THERE WHERE IFR CIGS AND VSBYS
ARE MORE WIDESPREAD. EXPECT THIS AREA OF IFR CIGS AND VSBYS IN
LIGHT SNOW TO DRIFT NORTHEAST TO OSH AND ATW TAF SITES AFTER ABOUT
02Z. LAKE ENHANCED SNOW BANDS OFF OF LAKE MICHIGAN WILL ALSO DRIFT
NORTHWESTWARD AND AFFECT LAKESHORE COUNTIES DURING THE EVENING
RESULTING IN IFR CIGS AND VSBYS FROM TIME TO TIME...WHICH COULD
ALSO AFFECT THE GRB TAF SITE THROUGH ABOUT 08Z.
AS SYSTEM MOVES EAST INTO LAKE MICHIGAN AFTER MIDNIGHT...LIGHT
SNOW SHOULD BEGIN TO DIMINISH...BUT CIGS SHOULD GENERALLY REMAIN
IN THE IFR CATEGORY...ESPECIALLY AT GRB...ATW AND OSH TAF SITES.
WESTERLY WINDS WILL DEVELOP BEHIND THE SYSTEM AND BECOME GUSTY BY
MORNING LATE MORNING MONDAY. THE GUSTY WEST WINDS WILL LIKELY
CREATE SOME BLOWING AND DRIFTING OF THE NEW SNOW PARTICULARLY OVER
THE FOX VALLEY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ013-020>022-
030-031-035>040-045-048>050-073-074.
&&
$$
UPDATE.........ESB
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......ESB
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
917 PM CST SUN DEC 8 2013
.UPDATE...
THE SNOW IS FINALLY WINDING DOWN AS THE MAIN WARM ADVECTION PUSHES
OFF TO THE EAST. THERE IS ANOTHER AREA OF SNOW SHOWING UP ON RADAR
ACROSS IOWA...BUT THE HRRR TAKES THIS MAINLY NORTH OF THE CWA. NOT
SURE ABOUT THAT GIVEN THE RADAR MOVEMENT. FORTUNATELY...THIS STUFF
ISN/T VERY HEAVY. IT/S WITH THE MAIN SHORT WAVE PUSHING THROUGH.
GIVEN THAT IT LOOKS LIKE THE LIGHT SNOW WILL CONTINUE FOR THE NEXT
3 MAYBE 4 HOURS...WILL NOT DO MUCH WITH THE ADVISORY AT THIS
POINT. ROADS ARE STILL IN BAD SHAPE...SO THERE/S THAT TO DEAL
WITH.
WINDS WILL SHIFT TO THE SOUTHWEST THEN WEST SHORTLY AFTER
MIDNIGHT...BUT NOT REALLY GET CRANKED UP UNTIL ABOUT 9 OR 10 AM
MONDAY MORNING. SO THE MORNING COMMUTE MAY BE SPARED FROM THE
WORST DRIFTING DUE TO THE WIND.
&&
.AVIATION/06Z TAFS/...
LOOK FOR GRADUALLY IMPROVING CONDITIONS THROUGH THE OVERNIGHT
HOURS. STILL EXPECT LIGHT SNOW TO CONTINUE THROUGH ABOUT 1 AM
TONIGHT. WINDS WILL BE RATHER LIGHT AND VARIABLE...UNTIL THEY
SHIFT AROUND TO THE SOUTHWEST BY ABOUT 1 AM...THEN WEST BY 4 AM.
THE STRONGEST WINDS WILL HOLD OFF UNTIL LATER MONDAY MORNING.
ANY LINGER IFR CIGS/VSBYS WILL IMPROVE TO MVFR CONDITIONS THROUGH
THE EVENING. SKIES WILL EVENTUALLY SCATTER OUT MONDAY AFTERNOON.
&&
.PREV DISCUSSION... /ISSUED 330 PM CST SUN DEC 8 2013/
TONIGHT AND MONDAY...FORECAST CONFIDENCE IS MEDIUM TO HIGH.
LIGHT TO MODERATE SNOW OCCURRING ACROSS THE AREA...AS FOCUSED LOW
LEVEL WARM AIR ADVECTION SHIFTS INTO THE AREA. GOOD BAND OF MODERATE
SNOW EXTENDING FROM CENTRAL AND EASTERN IOWA INTO NORTHERN
ILLINOIS...AND THIS SHOULD CONTINUE TO SHIFT NORTHEAST INTO THE AREA
OVER THE NEXT FEW HOURS. GOOD UPWARD VERTICAL MOTION IN DENDRITE
SNOW GROWTH ZONE EXPECTED THROUGH THE EVENING...AS POTENT 500MB
VORTICITY MAXIMUM MOVES NORTHEAST THROUGH THE AREA.
BUMPED UP SNOWFALL AMOUNTS A BIT...MAINLY IN THE FAR EAST WHERE THE
STRONG LAKE EFFECT SNOW BAND MOVED THROUGH EARLIER TODAY. GOING WITH
A 3 TO 5 INCH RANGE ACROSS MOST OF THE AREA...WITH A 4 TO 6 INCHES
IN THE FAR EASTERN COUNTIES. AMOUNTS AROUND 6 INCHES ARE POSSIBLE
ACROSS THE FAR NORTHEAST COUNTIES...WHERE LAKE ENHANCEMENT IS
EXPECTED THROUGH THE EVENING. KEPT WINTER WEATHER ADVISORY GOING FOR
THE AREA THROUGH 12Z MONDAY. MAY BE ABLE TO CANCEL THE SOUTHWESTERN
COUNTIES EARLY...IF SNOW ENDS SOONER THAN EXPECTED THERE.
GUSTY WEST WINDS WILL DEVELOP LATE TONIGHT INTO MONDAY...AND CAUSE
SOME BLOWING AND DRIFTING SNOW. THIS MAY HAVE AN IMPACT ON THE
MONDAY MORNING COMMUTE...ESPECIALLY ON NORTH TO SOUTH ROADS. LATER
SHIFTS WILL HAVE TO CONSIDER IF A HEADLINE WILL BE NEEDED FOR THE
MORNING COMMUTE.
TEMPERATURES WILL NOT RISE MUCH MONDAY...WITH COLD AIR ADVECTION
OCCURRING. TEMPERATURES IN THE TEENS ARE EXPECTED...WITH WIND CHILLS
IN THE SINGLE DIGITS ABOVE ZERO.
MONDAY NIGHT AND TUESDAY - CONFIDENCE...MEDIUM
POTENT SHORTWAVE ARRIVES FROM THE NORTHWEST. DIFFERENTIAL
CYCLONIC VORTICITY ADVECTION ARRIVES LATE MONDAY NIGHT AND THEN
SHIFTS QUICKLY EAST ON TUESDAY MORNING. GFS MORE ROBUST ON THE QPF
FIELD INTO THE NORTHERN CWA WHILE THE ECMWF AND NAM ARE FURTHER
NORTH. WITH THE LEADING WAA MOISTENING THINGS UP A BIT MONDAY
NIGHT WILL HAVE FLURRIES IN THE NW CWA AND THEN PUT A SMALL POP
INTO THE NORTHERN CWA ON TUESDAY AS UPPER DYNAMICS AND LOW LEVEL
FRONT MOVE THROUGH. LITTLE IF ANY SNOW ACCUM IN THE NORTHERN CWA.
TUESDAY NIGHT AND WEDNESDAY - CONFIDENCE...MEDIUM
ANOTHER SHORTWAVE DIVES IN ON THE PERSISTENT NORTHWEST FLOW. IN
THIS CASE THE FORCING IS SKEWED A BIT FURTHER SOUTH SO WILL HAVE
AREA WIDE POPS. RENEWED COLD FRONT AND FRONTAL FORCING ARRIVES
WEDNESDAY MORNING. NAM/GFS/GEM HAS PRECIP CONFINED TO THE SOUTHERN
CWA WHILE THE ECMWF SUGGESTS A MORE CWA WIDE COVERAGE OF PRECIP.
WILL KEEP SNOW AMOUNTS WITH THIS QUICK HITTER UNDER AN INCH.
WEDNESDAY NIGHT THROUGH FRIDAY - CONFIDENCE...MEDIUM
THIS IS LOOKING TO BE A DRY PERIOD. DIFFERENCES IN THE MODELS
ARISE WITH REGARDS TO TEMPS. GFS QUICKLY RETURNS WAA WHILE THE
ECMWF HANGS ONTO THE COLD. WILL FOLLOW THE LATTER AT THIS
POINT...KEEPING 925 TEMPS IN THE NEGATIVE TEENS CELSIUS.
FRIDAY NIGHT AND SATURDAY - CONFIDENCE...LOW
WHILE THE UPPER FLOW REMAINS LARGELY NORTHWEST...THE GFS AND GEM
IMPLY SOME PHASING OF SOME SOUTHERN AND NORTHERN STREAM ENERGY
WHILE THE ECMWF KEEPS THE DOMINANT WAVE WELL SOUTH AND KEEPS US
DRY. FOLLOWED ALLBLEND POPS FOR NOW WHICH HAS SOME SMALL CHANCES.
SUNDAY - CONFIDENCE...LOW
THE GFS KEEPS SOME PRECIP LINGERING WHILE THE ECMWF SHIFTS THE
COLD HIGH EAST OF WI WITH MODIFICATION IN THE 925 TEMPS.
AVIATION/00Z TAFS/...THE LIGHT TO MODERATE SNOW WILL CONTINUE
ACROSS TAF SITES THROUGH MOST OF THE EVENING...BEFORE QUICKLY
TAPERING OFF AROUND OR SOON AFTER MIDNIGHT FROM SOUTHWEST TO NORTHEAST.
RATES OF 1/4 TO 1/2 INCH PER HOUR ARE EXPECTED...WITH THE BEST RATES
OCCURRING THROUGH 03Z MONDAY. TOTAL ACCUMULATIONS OF 3 TO 4 INCHES
ARE EXPECTED AT MADISON AND WAUKESHA...TO 4 TO 6 INCH AMOUNTS AT
MILWAUKEE AND KENOSHA.
CEILINGS NEAR ALTERNATE MINIMUMS...AND VISIBILITIES BELOW...ARE
EXPECTED THROUGH THE EVENING. CEILINGS WILL REMAIN MVFR LATER
TONIGHT INTO MONDAY. EAST WINDS WILL WEAKEN THIS EVENING AS THE LOW
MOVES THROUGH THE AREA. GUSTY WEST WINDS BY 12Z MONDAY ARE
EXPECTED...AND LINGER THROUGH THE DAY. THIS WILL CAUSE SOME BLOWING
AND DRIFTING SNOW...ESPECIALLY ON NORTH TO SOUTH RUNWAYS.
MARINE...SMALL CRAFT ADVISORY IS IN EFFECT UNTIL 03Z MONDAY...AS
GUSTY WINDS AND HIGH WAVES LINGER. THERE WILL BE A LULL IN THE WINDS
LATER THIS EVENING INTO THE OVERNIGHT HOURS...WITH THE LOW MOVING
THROUGH THE AREA. WAVES SHOULD REMAIN BELOW THE 4 FOOT LEVEL.
GUSTY WEST WINDS WILL THEN OCCUR MONDAY AND MONDAY EVENING WITH A
TIGHT PRESSURE GRADIENT. HIGH WAVES SHOULD LINGER MAINLY OVER THE
OPEN WATERS WITH THE OFFSHORE FLOW. FREEZING SPRAY IS POSSIBLE IN
THIS AREA.
MAY NEED MORE SMALL CRAFT ADVISORIES OR GALE WATCHES/WARNINGS FOR
TUESDAY INTO WEDNESDAY...WITH GUSTY OFFSHORE WINDS WITHIN A TIGHT
PRESSURE GRADIENT. HIGH WAVES WILL BE TOWARD AND OVER THE OPEN
WATERS. FREEZING SPRAY IS POSSIBLE AS WELL IN THIS AREA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ046-047-051-
052-056>060-062>072.
LM...SMALL CRAFT ADVISORY UNTIL 9 PM CST THIS EVENING FOR LMZ643>646.
SMALL CRAFT ADVISORY FROM 6 AM TO 10 PM CST MONDAY FOR
LMZ643>646.
&&
$$
UPDATE...DAVIS
TONIGHT/MONDAY AND AVIATION/MARINE...WOOD
MONDAY NIGHT THROUGH SUNDAY...COLLAR
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
718 PM CST SUN DEC 8 2013
NEW INFORMATION ADDED TO UPDATE SECTION
.UPDATE...
ISSUED AT 644 PM CST SUN DEC 8 2013
SYSTEM AFFECTING THE FORECAST AREA HAS BEEN RATHER DISORGANIZED
AND DISJOINTED THUS FAR. SO FAR...SNOWFALL AMOUNTS HAVE BEEN
AROUND AN INCH OR SO THROUGH 6 PM. HOWEVER...WATER VAPOR IMAGERY
SHOWS SOMEWHAT MORE ROBUST SHORTWAVE DISTURBANCE ENTERING
SOUTHWEST WISCONSIN. THIS FEATURE HAS HELPED TO CREATE A SOMEWHAT
MORE SOLID AND ORGANIZED AREA OF LIGHT SNOW ACROSS SOUTHEAST
WISCONSIN WITH VSBYS GENERALLY BETWEEN ABOUT 1 AND 2 MILES. THIS
AREA OF LIGHT SNOW CONTINUES TO DRIFT NORTHEAST AND WILL LIKELY CLIP
THE SOUTHEAST PORTION OF THE FOX VALLEY GENERALLY SOUTH OF A LINE
FROM OSH TO KEWAUNEE OVER THE NEXT FEW HOURS.
FURTHER AS ANTICIPATED...AN AREA OF LAKE ENHANCED SNOW CONTINUES
TO DEVELOP OVER CENTRAL LAKE MICHIGAN AND IS DRIFTING NORTHWEST.
RADAR REFLECTIVITIES HAVE BEEN GRADUALLY INCREASING AND EXPNADING
IN AREA COVERAGE OVER THE LAST HOUR. APPEARS ACTIVITY AHEAD OF
APPROACHING SHORTWAVE ENTERING SOUTHWEST WISCONSIN CONTRIBUTING TO
LES ENHANCEMENT OVER CENTRAL LAKE MICHIGAN VIA SEEDER-FEEDER
MECHANISM.
THUS...EXPECT TO SEE SOMEWHAT HIGHER SNOWFALL RATES ACROSS THE
FOX VALLEY THIS EVENING IN ASSOCIATION WITH SHORTWAVE MOVING
ACROSS SOUTHEAST WISCONSIN AND LAKE ENHANCEMENT OFF LAKE MICHIGAN.
COULD SEE ANOTHER INCH OR PERHAPS TWO MY MIDNIGHT ESPECIALLY
SOUTHEAST OFF A LINE FROM STURGEON BAY TO GREEN BAY TO OSHKOSH.
LOOKING FURTHER UPSTREAM...PRIMARY SHORTWAVE DISTURBANCE NOW
ENTERING NORTHWEST IOWA. THIS FEATURE IS ALSO FORECAST TO MOVE
ACROSS THE SOUTHERN WISCONSIN AFTER MIDNIGHT AND MAY HELP TO KEEP
SOME LIGHT SNOW GOING AFTER MIDNIGHT ESPECIALLY OVER THE
SOUTHEAST HALF OF THE FORECAST AREA. HOWEVER...LOOKING AT SURFACE
OBSERVATIONS OVER IOWA...VSBYS NOT VERY LOW AND WERE IN THE 2 TO 4
MILE RANGE. IN FACT THE LATEST HRRR AND RUC FORECASTS SEEM TO
SIGNIFICANTLY DISSOLVE THE AREA OF QPF AS THIS FEATURE APPROACHES
WISCONSIN.
FORCING ACROSS THE NORTHWEST THIRD OF THE FORECAST AREA NOT
EXPECTED TO BE VERY STRONG AND THUS FAR SNOWFALL RATES UP THERE
HAVE BEEN QUITE LIGHT WITH VSBYS GENERALLY IN THE 2 TO 4 MILE
RANGE. WILL SEE HOW THE SHORTWAVE MOVING OUT OF IOWA EVOLVES LATER
THIS EVENING...BUT IF CURRENT TRENDS CONTINUE MAY NEED TO CANCEL ADVISORY
UP THERE.
FOR NOW WILL KEEP ADVISORY GOING OVER ENTIRE FORECAST AREA AND
WILL REVIST A BIT LATER THIS EVENING. BOTTOM LINE IS IT APPEARS
MOST SIGNIFICANT SNOWFALL WILL BE FOCUSED OVER THE FOX VALLEY AND
LAKESHORE. APPEARS FINAL SNOWFALL TOTALS WILL BE ON THE LOW END OF
CURRENT FORECAST.
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ONE SHORTWAVE
TROUGH MOVING INTO SOUTHWEST WISCONSIN THIS AFTERNOON...WHILE
ANOTHER WAVE NOW ENTERING THE CENTRAL GREAT PLAINS. AHEAD OF THE
FORMER SHORTWAVE...WEAK ISENTROPIC ASCENT IS PRODUCING A WIDESPREAD
SWATH OF LIGHT SNOW ACROSS THE STATE. THE BETTER SNOWS WITH THE
FIRST WAVE ARE STILL ACROSS IOWA AT THE MOMENT...WHERE VSBYS ARE
DOWN TO A HALF MILE AND WIDESPREAD 1-2 INCHES ARE BEING REPORTED SO
FAR. FURTHER CONCERNS RESIDE ALONG THE LAKE SHORE WHERE LAKE
ENHANCEMENT IS OCCURRING OVER CENTRAL AND SOUTHERN PARTS OF THE LAKE
MICHIGAN SHORELINE. EARLIER REPORTS SHOWED 1-1.5 INCH PER HOUR
SNOWFALL RATES IN THOSE LAKE ENHANCED BANDS. ONE OF THESE BANDS IS
APPROACHING MANITOWOC...BUT APPEARS TRANSIENT IN A LOW LEVEL
CONVERGENT ZONE. LOW LEVEL WINDS ARE JUST STARTING TO TURN TO THE
SOUTHEAST SO WILL NEED TO WATCH THESE TRENDS FOR THE REST OF THE
AFTERNOON. AS THE SHORTWAVES MOVE ACROSS THE ARE TONIGHT...SNOWFALL
AMOUNTS AND IMPACTS ARE THE MAIN FORECAST CONCERN.
TONIGHT...SHORTWAVE TROUGH OVER COLORADO WILL QUICKLY EJECT
NORTHEAST A DRIVE A STRENGTHENING...ALTHOUGH STILL RELATIVELY
WEAK...AREA OF LOW PRESSURE FROM THE CENTRAL GREAT PLAINS AND ACROSS
SOUTHEAST WISCONSIN TONIGHT. FORCING AHEAD OF THE SHORTWAVE IN THE
FORM OF -DIVQ...UPPER DIVERGENCE...AND ISENTROPIC ASCENT IS ONLY
MODEST...BUT BUFKIT SOUNDINGS FROM THE NAM/GFS/SREF ALL INDICATE A
150-200MB DEEP DENDRITIC GROWTH ZONE BETWEEN APPROX 850-650MB OVER
CENTRAL AND NORTHEAST WISCONSIN. THIS SUGGESTS THAT WHATEVER WEAK
TO MODERATE LIFT THAT OCCURS...SNOW FLAKE PRODUCTION WILL BE VERY
EFFICIENT AND SNOW TO LIQUID RATIOS WILL BE QUITE HIGH. GENERALLY
WENT WITH A 19-20:1 RATIO...ALTHOUGH A LITTLE LOWER NEAR THE LAKE
MICHIGAN SHORELINE WHERE ONSHORE FLOW WILL LEAD TO SLIGHTLY WARMER
LOW LEVEL THERMAL PROFILES. THE BULK OF THE SNOW LOOKS TO OCCUR IN
A COUPLE WAVES. THE FIRST WILL ARRIVE LATE THIS AFTERNOON INTO EARLY
THIS EVENING FROM THE FIRST AREA OF SNOW OVER IOWA AND SE
MINNESOTA...FOLLOW BY THE MAIN SHORTWAVE AND SURFACE LOW OVER
COLORADO. PLENTY OF 1-3" INCH REPORTS UPSTREAM OVER IOWA...AND FEW
4-6 INCH REPORTS OVER EASTERN NEBRASKA AS WELL. WILL INCREASE
AMOUNTS A LITTLE OVER N-C WISCONSIN TO AROUND 3 INCHES. THE PRIMARY
CONCERN THOUGH WILL BE ALONG THE LAKE SHORE WHERE WINDS WILL BE
TURNING TO THE EAST AND SOUTHEAST THIS EVENING. THE LAKE ENHANCEMENT
OVER SOUTHEAST WISCONSIN APPEARS TO BE FLUCTUATING...AS A CONVERGENT
BAND LIFTS NORTH. BUT EARLIER SNOWFALL RATES WHERE ENHANCEMENT TOOK
PLACE ARE ALARMING. LOOKS LIKE A GOOD 9-12 HOURS OF ENHANCEMENT
POSSIBLE OVER NORTHEAST WISCONSIN. WILL GO WITH WIDESPREAD 2-4
INCHES EXCEPT NEAR THE LAKESHORE WHERE 5-6 INCHES WILL BE POSSIBLE.
HEADLINES WILL REMAIN THE SAME...AND WILL PASS ALONG LAKE
ENHANCEMENT CONCERNS TO THE EVENING SHIFT.
MONDAY...THE SNOW WILL BE ENDING EARLY MONDAY MORNING OVER NORTHEAST
WISCONSIN AS THE SURFACE LOW PULLS AWAY. WEST WINDS WILL BE
STRENGTHENING IN THE WAKE OF THE LOW AND COLD ADVECTING AT THE SAME
TIME. TEMPS WILL REMAIN NEARLY STEADY OR FALL SLIGHTLY DURING THE
DAY...DESPITE CLEARING TAKING PLACE. WITH WINDS GUSTING TO 30
MPH...APPARENT TEMPS WILL BE FALLING TO NEAR 20 BELOW ZERO OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN DURING THE AFTERNOON. WILL
LIKELY NEED WIND CHILL HEADLINES...BUT WITH THE ONGOING SNOW
ADVISORY...WILL NOT ISSUE ANOTHER HEADLINE. MORNING TO MIDDAY HIGHS
IN THE MIDDLE SINGLE DIGITS NORTH TO THE UPPER TEENS NEAR THE LAKE
SHORE.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
VERY COLD AIR WILL REMAIN FIRMLY ENTRENCHED ACROSS THE AREA
MONDAY NIGHT. EXPECT WINDS CHILLS TO DROP TO AROUND 25 BELOW
ACROSS THE NORTH. HOWEVER...TEMPERATURES ARE EXPECTED TO
MODIFY SOME LATE MONDAY NIGHT DUE TO INCREASING CLOUDINESS
AND AHEAD OF APPROACHING SYSTEM. INCREASED CHANCES OF SNOW
ACROSS THE NORTHWEST HALF OF THE FORECAST AREA. INCREASED SNOW
CHANCES SIGNIFICANTLY ON TUESDAY MORNING AS SYSTEM MOVES ACROSS
THE AREA. ALSO...PRECIPITATION TOTALS WILL BE LIGHT...SNOW RATIOS
WOULD SUGGEST LESS THAN AN INCH OF NEW SNOW TUESDAY MORNING. THE
HIGHEST SNOWFALL TOTALS WILL BE ACROSS THE NORTH.
MOST OF THE MODELS NOW BRING CLIPPER SYSTEM SOUTH OF THE AREA
TUESDAY NIGHT. THE ONLY EXCEPTION WAS THE ECMWF...THUS WILL CONTINUE
CHANCES ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. THE GFS MODELS
HAS BEEN WAFFLING ON NORTHWARD EXTENT OF THE PRECIPITATION FIELD. VERY
COLD AIR IS EXPECTED WEDNESDAY MORNING. ANOTHER SYSTEM EXPECTED TO
PASS ACROSS THE NORTH THURSDAY/THURSDAY NIGHT. LOW CONFIDENCE ON WHEN
THIS SYSTEM WOULD BRING A SMALL CHANCE OF LIGHT SNOW DURING THIS PERIOD.
CURRENT FORECAST HAS LIGHT SNOW IN THE FORECAST THURSDAY NIGHT...BUT
LATER SHIFTS MAY NEED TO SPEED UP THE SNOW AND ADD A CHANCE TO THE
THURSDAY PERIOD. THE ARCTIC AIR WILL MODIFY FRIDAY INTO NEXT WEEKEND
WITH HIGHS IN THE UPPER TEENS TO MIDDLE 20S.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 608 PM CST SUN DEC 8 2013
WEAK LOW PRESSURE WILL MOVE NORTHEAST ACROSS SOUTHERN
WISCONSIN INTO LOWER MICHIGAN OVERNIGHT BRINGING LIGHT SNOW TO THE
AREA. SYSTEM OVERALL IS SOMEWHAT DISJOINTED AND DISORGANIZED THUS
SNOWFALL RATES NOT VERY IMPRESSIVE SO FAR THIS EVENING. MAINLY
MVFR CIGS AND VSBYS CAN BE EXPECTED THROUGH 06Z AT CENTRAL AND
NORTHERN WISCONSIN TAFS SITES. SOMEWHAT STRONGER UPPER-LEVEL
FORCING OVER SOUTHEAST WISCONSIN HAS HELPED TO GENERATE SOMEWHAT
MORE ORGANIZED AREA OF LIGHT SNOW THERE WHERE IFR CIGS AND VSBYS
ARE MORE WIDESPREAD. EXPECT THIS AREA OF IFR CIGS AND VSBYS IN
LIGHT SNOW TO DRIFT NORTHEAST TO OSH AND ATW TAF SITES AFTER ABOUT
02Z. LAKE ENHANCED SNOW BANDS OFF OF LAKE MICHIGAN WILL ALSO DRIFT
NORTHWESTWARD AND AFFECT LAKESHORE COUNTIES DURING THE EVENING
RESULTING IN IFR CIGS AND VSBYS FROM TIME TO TIME...WHICH COULD
ALSO AFFECT THE GRB TAF SITE THROUGH ABOUT 08Z.
AS SYSTEM MOVES EAST INTO LAKE MICHIGAN AFTER MIDNIGHT...LIGHT
SNOW SHOULD BEGIN TO DIMINISH...BUT CIGS SHOULD GENERALLY REMAIN
IN THE IFR CATEGORY...ESPECIALLY AT GRB...ATW AND OSH TAF SITES.
WESTERLY WINDS WILL DEVELOP BEHIND THE SYSTEM AND BECOME GUSTY BY
MORNING LATE MORNING MONDAY. THE GUSTY WEST WINDS WILL LIKELY
CREATE SOME BLOWING AND DRIFTING OF THE NEW SNOW PARTICULARLY OVER
THE FOX VALLEY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
UPDATE.........ESB
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......ESB
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
611 PM CST SUN DEC 8 2013
UPDATED AVIATION PORTION FOR 00Z TAF ISSUANCE
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ONE SHORTWAVE
TROUGH MOVING INTO SOUTHWEST WISCONSIN THIS AFTERNOON...WHILE
ANOTHER WAVE NOW ENTERING THE CENTRAL GREAT PLAINS. AHEAD OF THE
FORMER SHORTWAVE...WEAK ISENTROPIC ASCENT IS PRODUCING A WIDESPREAD
SWATH OF LIGHT SNOW ACROSS THE STATE. THE BETTER SNOWS WITH THE
FIRST WAVE ARE STILL ACROSS IOWA AT THE MOMENT...WHERE VSBYS ARE
DOWN TO A HALF MILE AND WIDESPREAD 1-2 INCHES ARE BEING REPORTED SO
FAR. FURTHER CONCERNS RESIDE ALONG THE LAKE SHORE WHERE LAKE
ENHANCEMENT IS OCCURRING OVER CENTRAL AND SOUTHERN PARTS OF THE LAKE
MICHIGAN SHORELINE. EARLIER REPORTS SHOWED 1-1.5 INCH PER HOUR
SNOWFALL RATES IN THOSE LAKE ENHANCED BANDS. ONE OF THESE BANDS IS
APPROACHING MANITOWOC...BUT APPEARS TRANSIENT IN A LOW LEVEL
CONVERGENT ZONE. LOW LEVEL WINDS ARE JUST STARTING TO TURN TO THE
SOUTHEAST SO WILL NEED TO WATCH THESE TRENDS FOR THE REST OF THE
AFTERNOON. AS THE SHORTWAVES MOVE ACROSS THE ARE TONIGHT...SNOWFALL
AMOUNTS AND IMPACTS ARE THE MAIN FORECAST CONCERN.
TONIGHT...SHORTWAVE TROUGH OVER COLORADO WILL QUICKLY EJECT
NORTHEAST A DRIVE A STRENGTHENING...ALTHOUGH STILL RELATIVELY
WEAK...AREA OF LOW PRESSURE FROM THE CENTRAL GREAT PLAINS AND ACROSS
SOUTHEAST WISCONSIN TONIGHT. FORCING AHEAD OF THE SHORTWAVE IN THE
FORM OF -DIVQ...UPPER DIVERGENCE...AND ISENTROPIC ASCENT IS ONLY
MODEST...BUT BUFKIT SOUNDINGS FROM THE NAM/GFS/SREF ALL INDICATE A
150-200MB DEEP DENDRITIC GROWTH ZONE BETWEEN APPROX 850-650MB OVER
CENTRAL AND NORTHEAST WISCONSIN. THIS SUGGESTS THAT WHATEVER WEAK
TO MODERATE LIFT THAT OCCURS...SNOW FLAKE PRODUCTION WILL BE VERY
EFFICIENT AND SNOW TO LIQUID RATIOS WILL BE QUITE HIGH. GENERALLY
WENT WITH A 19-20:1 RATIO...ALTHOUGH A LITTLE LOWER NEAR THE LAKE
MICHIGAN SHORELINE WHERE ONSHORE FLOW WILL LEAD TO SLIGHTLY WARMER
LOW LEVEL THERMAL PROFILES. THE BULK OF THE SNOW LOOKS TO OCCUR IN
A COUPLE WAVES. THE FIRST WILL ARRIVE LATE THIS AFTERNOON INTO EARLY
THIS EVENING FROM THE FIRST AREA OF SNOW OVER IOWA AND SE
MINNESOTA...FOLLOW BY THE MAIN SHORTWAVE AND SURFACE LOW OVER
COLORADO. PLENTY OF 1-3" INCH REPORTS UPSTREAM OVER IOWA...AND FEW
4-6 INCH REPORTS OVER EASTERN NEBRASKA AS WELL. WILL INCREASE
AMOUNTS A LITTLE OVER N-C WISCONSIN TO AROUND 3 INCHES. THE PRIMARY
CONCERN THOUGH WILL BE ALONG THE LAKE SHORE WHERE WINDS WILL BE
TURNING TO THE EAST AND SOUTHEAST THIS EVENING. THE LAKE ENHANCEMENT
OVER SOUTHEAST WISCONSIN APPEARS TO BE FLUCTUATING...AS A CONVERGENT
BAND LIFTS NORTH. BUT EARLIER SNOWFALL RATES WHERE ENHANCEMENT TOOK
PLACE ARE ALARMING. LOOKS LIKE A GOOD 9-12 HOURS OF ENHANCEMENT
POSSIBLE OVER NORTHEAST WISCONSIN. WILL GO WITH WIDESPREAD 2-4
INCHES EXCEPT NEAR THE LAKESHORE WHERE 5-6 INCHES WILL BE POSSIBLE.
HEADLINES WILL REMAIN THE SAME...AND WILL PASS ALONG LAKE
ENHANCEMENT CONCERNS TO THE EVENING SHIFT.
MONDAY...THE SNOW WILL BE ENDING EARLY MONDAY MORNING OVER NORTHEAST
WISCONSIN AS THE SURFACE LOW PULLS AWAY. WEST WINDS WILL BE
STRENGTHENING IN THE WAKE OF THE LOW AND COLD ADVECTING AT THE SAME
TIME. TEMPS WILL REMAIN NEARLY STEADY OR FALL SLIGHTLY DURING THE
DAY...DESPITE CLEARING TAKING PLACE. WITH WINDS GUSTING TO 30
MPH...APPARENT TEMPS WILL BE FALLING TO NEAR 20 BELOW ZERO OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN DURING THE AFTERNOON. WILL
LIKELY NEED WIND CHILL HEADLINES...BUT WITH THE ONGOING SNOW
ADVISORY...WILL NOT ISSUE ANOTHER HEADLINE. MORNING TO MIDDAY HIGHS
IN THE MIDDLE SINGLE DIGITS NORTH TO THE UPPER TEENS NEAR THE LAKE
SHORE.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
VERY COLD AIR WILL REMAIN FIRMLY ENTRENCHED ACROSS THE AREA
MONDAY NIGHT. EXPECT WINDS CHILLS TO DROP TO AROUND 25 BELOW
ACROSS THE NORTH. HOWEVER...TEMPERATURES ARE EXPECTED TO
MODIFY SOME LATE MONDAY NIGHT DUE TO INCREASING CLOUDINESS
AND AHEAD OF APPROACHING SYSTEM. INCREASED CHANCES OF SNOW
ACROSS THE NORTHWEST HALF OF THE FORECAST AREA. INCREASED SNOW
CHANCES SIGNIFICANTLY ON TUESDAY MORNING AS SYSTEM MOVES ACROSS
THE AREA. ALSO...PRECIPITATION TOTALS WILL BE LIGHT...SNOW RATIOS
WOULD SUGGEST LESS THAN AN INCH OF NEW SNOW TUESDAY MORNING. THE
HIGHEST SNOWFALL TOTALS WILL BE ACROSS THE NORTH.
MOST OF THE MODELS NOW BRING CLIPPER SYSTEM SOUTH OF THE AREA
TUESDAY NIGHT. THE ONLY EXCEPTION WAS THE ECMWF...THUS WILL CONTINUE
CHANCES ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. THE GFS MODELS
HAS BEEN WAFFLING ON NORTHWARD EXTENT OF THE PRECIPITATION FIELD. VERY
COLD AIR IS EXPECTED WEDNESDAY MORNING. ANOTHER SYSTEM EXPECTED TO
PASS ACROSS THE NORTH THURSDAY/THURSDAY NIGHT. LOW CONFIDENCE ON WHEN
THIS SYSTEM WOULD BRING A SMALL CHANCE OF LIGHT SNOW DURING THIS PERIOD.
CURRENT FORECAST HAS LIGHT SNOW IN THE FORECAST THURSDAY NIGHT...BUT
LATER SHIFTS MAY NEED TO SPEED UP THE SNOW AND ADD A CHANCE TO THE
THURSDAY PERIOD. THE ARCTIC AIR WILL MODIFY FRIDAY INTO NEXT WEEKEND
WITH HIGHS IN THE UPPER TEENS TO MIDDLE 20S.
&&
.AVIATION...FOR 00Z TAF ISSUANCE
ISSUED AT 608 PM CST SUN DEC 8 2013
WEAK LOW PRESSURE WILL MOVE NORTHEAST ACROSS SOUTHERN
WISCONSIN INTO LOWER MICHIGAN OVERNIGHT BRINGING LIGHT SNOW TO THE
AREA. SYSTEM OVERALL IS SOMEWHAT DISJOINTED AND DISORGANIZED THUS
SNOWFALL RATES NOT VERY IMPRESSIVE SO FAR THIS EVENING. MAINLY
MVFR CIGS AND VSBYS CAN BE EXPECTED THROUGH 06Z AT CENTRAL AND
NORTHERN WISCONSIN TAFS SITES. SOMEWHAT STRONGER UPPER-LEVEL
FORCING OVER SOUTHEAST WISCONSIN HAS HELPED TO GENERATE SOMEWHAT
MORE ORGANIZED AREA OF LIGHT SNOW THERE WHERE IFR CIGS AND VSBYS
ARE MORE WIDESPREAD. EXPECT THIS AREA OF IFR CIGS AND VSBYS IN
LIGHT SNOW TO DRIFT NORTHEAST TO OSH AND ATW TAF SITES AFTER ABOUT
02Z. LAKE ENHANCED SNOW BANDS OFF OF LAKE MICHIGAN WILL ALSO DRIFT
NORTHWESTWARD AND AFFECT LAKESHORE COUNTIES DURING THE EVENING
RESULTING IN IFR CIGS AND VSBYS FROM TIME TO TIME...WHICH COULD
ALSO AFFECT THE GRB TAF SITE THROUGH ABOUT 08Z.
AS SYSTEM MOVES EAST INTO LAKE MICHIGAN AFTER MIDNIGHT...LIGHT
SNOW SHOULD BEGIN TO DIMINISH...BUT CIGS SHOULD GENERALLY REMAIN
IN THE IFR CATEGORY...ESPECIALLY AT GRB...ATW AND OSH TAF SITES.
WESTERLY WINDS WILL DEVELOP BEHIND THE SYSTEM AND BECOME GUSTY BY
MORNING LATE MORNING MONDAY. THE GUSTY WEST WINDS WILL LIKELY
CREATE SOME BLOWING AND DRIFTING OF THE NEW SNOW PARTICULARLY OVER
THE FOX VALLEY.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ005-010>013-
018>022-030-031-035>040-045-048>050-073-074.
&&
$$
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......ESB
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
330 PM CST SAT DEC 7 2013
.SHORT TERM...
TONIGHT...FORECAST CONFIDENCE IS HIGH
HIGH PRESSURE WILL SLIDE EAST ACROSS THE REGION TONIGHT. HIGH CLOUDS
WILL STREAM EAST NORTHEASTWARD INTO THE AREA LATER THIS EVENING AND
OVERNIGHT. TEMPERATURES MAY DROP QUICKLY THIS EVENING THROUGH THE
SINGLE DIGITS ABOVE ZERO...AS WINDS DECOUPLE WITH THE PASSING HIGH.
TEMPERATURES SHOULD THEN BECOME STEADY OR SLOWLY RISE LATER
TONIGHT...AS THE CLOUDS MOVE INTO THE AREA.
LAKE EFFECT SNOW SHOWER BAND SHOULD SET UP NORTH TO SOUTH ON THE
EASTERN SIDE OF LAKE MICHIGAN INTO THE SOUTHERN END OF THE LAKE THIS
EVENING. HRRR INDICATING THIS BAND SHOULD GRADUALLY SHIFT TO THE
WEST NORTHWEST LATER TONIGHT...POSSIBLY TRACKING INTO THE FAR
SOUTHEAST COUNTIES NEAR THE LAKE IN THE 09Z TO 12Z SUNDAY PERIOD.
ADDED POPS IN THIS AREA FOR THIS POSSIBILITY. MOST OF THE LAKE
EFFECT SNOW SHOWERS SHOULD HOLD OFF UNTIL AFTER 12Z SUNDAY.
SUNDAY THROUGH TUESDAY...FORECAST CONFIDENCE MEDIUM TO HIGH
THE MODELS ARE VERY SIMILAR WITH A WEAK BUT DEVELOPING LOW
PRESSURE THAT WILL APPROACH FROM THE PLAINS. THE SFC LOW WILL
BECOME CLOSED OFF AT 1015 MB NEAR OR EAST OF KMKE BY 06Z MON AND
CONTINUE TO DEEPEN AS IT MOVES THROUGH THE NORTHERN GREAT LAKES
AND INTO CANADA ON MON. A LARGE SCALE AND FAIRLY IMPRESSIVE LOW TO
MID LEVEL WARM ADVECTION PATTERN WITH WILL OVERSPREAD THE REGION
ON SUN WITH SNOW INTENSIFYING LATER IN THE AFTERNOON AND EVENING
WHEN THE SHORTWAVE TROUGH APPROACHES FROM THE SW.
A CONSENSUS OF THE MODELS ON QPF YIELDS QPF TOTALS OF 0.15-0.22.
THE DEPTH OF THE DENDRITE ZONE VARIES ON MODELS BUT HAS TRENDED
LESS DEEP FROM YESTERDAY. THEREFORE WILL GO WITH A MODEL CONSENSUS
OF SNOW RATIOS CLOSE TO 20 TO 1 VERSUS SOMETHING HIGHER. THIS
YIELDS 3 TO 4 INCHES WITH THE EXCEPTION OF 2-3 NEAR THE IL BORDER.
THERE HAS BEEN A SLIGHT NWD TREND WITH THE SHORTWAVE TROUGH AND
QPF...SO LESSER AMOUNTS NEAR THE IL BORDER IS REASONABLE. LAKE
ENHANCED SNOWS THEN NEED TO BE ADDED IN FOR OZAUKEE AND SHEBOYGAN
COUNTIES GIVEN THE 1000-850 MB SELY FLOW AND LAKE TO 850 MB TEMP
DIFFERENCES OF 14-17C. THE LAKE EFFECT SNOW CHARTS SUGGESTS ADDING
AT LEAST 3 INCHES SO FORECASTING 4-7 INCHES OF SNOW IN SHEBOYGAN
AND NRN OZAUKEE COUNTIES. IF GREATER LAKE ENHANCED SNOW IS EXPECTED
A WINTER STORM WARNING MAY BE NEEDED. A WINTER WX ADVISORY IS IN
EFFECT FOR ALL OF THE CWA FOR THIS SNOW EVENT.
BRISK WESTERLY WINDS AND COLD ADVECTION TO PREVAIL ON MON WITH
THE ARCTIC AIRMASS RETURNING AFTER HIGHS IN THE 20S ON SUN. WIND
GUSTS TO 25 MPH COMBINED WITH A POWDERY SNOW PACK SHOULD RESULT IN
AREAS OF BLOWING AND DRIFTING SNOW THAT WILL LIKELY CAUSE SOME
PROBLEMS THROUGHOUT THE DAY FOR TRAVEL. A SHORTWAVE SFC RIDGE WILL
MOVE ACROSS SRN WI MON NT WITH RADIATIONAL COOLING AND ARCTIC AIR
MAKING FOR ANOTHER VERY COLD NIGHT. SWLY WINDS WILL DEVELOP TOWARD
MORNING AS AN ALBERTA CLIPPER MOVES ACROSS THE NORTHERN GREAT
LAKES. WILL LIKELY ONLY SEE SCT-BKN CLOUD COVER FROM IT ON TUE
WITH THE SNOW REMAINING OVER NRN WI. DESPITE SWLY WINDS...HIGH
TEMPS TO ONLY REACH INTO THE TEENS. THE BRISK WINDS HOWEVER WILL
MAINTAIN VERY COLD WIND CHILLS FOR MON-TUE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE
MEDIUM.
A COUPLE WEAK CLIPPERS WILL BRING ONLY SMALL CHANCES OF LIGHT SNOW
OR FLURRIES FOR TUE NT INTO POSSIBLY WED AND AGAIN FOR THU. ARCTIC
AIR WILL REMAIN OVER THE AREA INTO THU NT. LOW PRESSURE WILL THEN
APPROACH FROM THE NRN PLAINS FOR LATE IN THE WEEK WITH WARM
ADVECTION BRINGING MODERATING TEMPS AND CHANCES OF LGT SNOW.
&&
.AVIATION/00Z TAFS/...
VFR CONDITIONS ARE EXPECTED TONIGHT ACROSS TAF SITES. WEST NORTHWEST
WINDS WILL GRADUALLY WEAKEN AND BECOME LIGHT TO CALM TONIGHT...WITH
HIGH CLOUDS MOVING INTO THE AREA BY LATER TONIGHT.
A LAKE EFFECT SNOW BAND WILL MOVE NORTHWARD TO KENOSHA AROUND 12Z
SUNDAY...AND MILWAUKEE/WAUKESHA BY 15Z SUNDAY. THE LIGHT SNOW
SHOWERS WITH THE BAND WILL LINGER FOR A 3 TO 5 HOUR PERIOD
THEREAFTER...WITH MVFR/IFR CEILINGS AND VISIBILITIES OF 2 TO 3
MILES. LIGHT ACCUMULATIONS OF UP TO 0.5 INCHES IS POSSIBLE. EAST
SOUTHEAST WINDS WILL INCREASE SUNDAY.
THE LIGHT TO MODERATE SNOW WITH THE LOW PRESSURE SYSTEM MOVING
NORTHEAST THROUGH THE REGION WILL REACH MADISON BY 15Z SUNDAY...AND
THE EASTERN SITES BY 18Z SUNDAY. THE SNOW WILL BECOME ALL LIGHT
BETWEEN 04Z AND 06Z MONDAY WEST TO EAST ACROSS TAF SITES...THEN
ENDING BETWEEN 09Z AND 12Z MONDAY SOUTHWEST TO NORTHEAST. WINDS WILL
VEER SOUTHWEST BY 06Z MONDAY...AND WEST BY 12Z MONDAY. WINDS WILL
BECOME GUSTY LATE SUNDAY NIGHT INTO MONDAY...WITH SOME BLOWING AND
DRIFTING SNOW.
CEILINGS/VISIBILITIES AT OR BELOW ALTERNATE MINIMUMS ARE
EXPECTED...WITH SOME 1/2 MILE VISIBILITIES POSSIBLE AT TIMES. THE
SNOW IS EXPECTED TO BE OF THE LIGHT AND FLUFFY VARIETY. SNOWFALL
RATES OF 1/4 TO 1/2 INCH PER HOUR ARE EXPECTED...WITH LOCALLY HIGHER
RATES POSSIBLE. TOTAL SNOW ACCUMULATIONS OF 3 TO 4 INCHES ARE
EXPECTED...HIGHEST AT MADISON/MILWAUKEE AND LOWEST AT KENOSHA.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...WINTER WEATHER ADVISORY FROM NOON SUNDAY TO 6 AM CST MONDAY FOR
WIZ046-047-051-052-056>060-062>072.
LM...NONE.
&&
$$
TONIGHT/SUNDAY AND AVIATION/MARINE...WOOD
SUNDAY NIGHT THROUGH SATURDAY...GEHRING
AREA FORECAST DISCUSSION
NWS TAUNTON MA
100 AM EST MON DEC 9 2013
.SYNOPSIS...
LOW PRESSURE LIFTING NORTH FROM THE MID ATLANTIC WILL BRING MIXED
PRECIP LATE TONIGHT INTO MONDAY. MAINLY DRY...BUT UNSEASONABLY
COLD AND BLUSTERY WEATHER IS EXPECTED FOR THE REST OF THE UPCOMING
WORK WEEK. WE WILL HAVE TO KEEP AN EYE ON THE POTENTIAL FOR A
PERIOD OF LIGHT SNOW ON TUESDAY...MAINLY SOUTH OF THE MASSACHUSETTS
TURNPIKE.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1 AM UPDATE...
AREAS OF LIGHT SNOW AND FREEZING DRIZZLE BREAKING OUT ACROSS SNE.
DRY AIR IN THE SNOW GROWTH REGION AND LIGHT PRECIP RESULTING IN
AREAS OF FZDZ...BUT EXPECT PRECIP TO BECOME SNOW AS STRONGER OMEGA
AND STEADIER PRECIP DEVELOPS. HOWEVER...WARMER AIR ALOFT HAS
ALREADY REACHED THE SW CT COAST WITH FZRA NOW AT BDR. THIS WILL
BE LIFTING NE SO THE SNOW NEAR THE COAST WILL BE SHORT
LIVED...CHANGING TO SLEET/FZRA 08-10Z.
LATEST NAM STILL INDICATING POTENTIAL FOR MESOSCALE BANDING MOVING
UP ALONG THE S COAST AND CAPE/ISLANDS THROUGH 09Z AS STRONG 850
MB FRONTOGENESIS DEVELOPS WITHIN TIGHTENING THERMAL GRADIENT AND
DECENT LIFT IN THE SNOW GROWTH REGION. HOWEVER...THIS IS THE TIME
THE WARM NOSE ABOVE 800 MB MOVES IN SO PRECIP WILL LIKELY BE
CHANGING TO SLEET/FZRA/RA DURING THIS TIME WHICH WILL LIMIT SNOW
ACCUM TO A COATING TO POSSIBLY AN INCH.
&&
.SHORT TERM /2 AM THIS MORNING THROUGH 6 PM TUESDAY/...
AN OPEN-WAVE TROUGH ACROSS THE GREAT LAKES REGION HAS BEGUN TO
INTERACT WITH THE BROADER SUB-TROPICAL FLOW ACROSS THE EASTERN
CONUS. INFLECTION ALONG THE COLLOCATED TIGHT THERMAL GRADIENT HAS
SUBSEQUENTLY RESULTED IN A WEAK AREA OF LOW PRESSURE PRESENTLY OFF
THE MID-ATLANTIC WHICH WILL DRIFT NORTHEASTWARD ACROSS CAPE COD
BRINGING WITH IT A WINTRY MIX OF SNOW...SLEET...AND FREEZING RAIN
FOR SOUTHERN NEW ENGLAND DURING THE TIMEFRAME /ESPECIALLY THE MONDAY
MORNING COMMUTE/.
HAVE GREATER CONFIDENCE WITH COLDER SOLUTIONS. WITH BROAD AGREEMENT
AND RUN-TO-RUN CONTINUITY FROM THE ECMWF...PREFER THE MESO-NAM AND
WRF-MODEL SOLUTIONS WHICH CAPTURE THE COLD-AIR DAMMING PROCESSES
THROUGH THE CONNECTICUT RIVER VALLEY /SEE 1000-850 THICKNESSES/.
TRENDS ARE NOTEWORTHY WITHIN THE LATEST HRRR RUNS. BUT OVERALL THERE
IS STILL PLENTY OF UNCERTAINTY CONCERNING THERMAL PROFILES AND THE
ACCOMPANYING TRANSITION PROCESS OF WINTRY WEATHER TO PLAIN RAIN.
THAT BEING SAID...THERE IS A LOT TO CONSIDER. WITH H975 AGEOSTROPHIC
FLOW OUT OF THE INTERIOR NORTH WITH A WEAK LOW TRACKING ACROSS THE
CAPE...NOT EXPECTING EASTERLY ONSHORE FLOW NORTH OF THE LOW TO SCOUR
OUT INTERIOR SURFACE COLD AIR EFFECTIVELY. EXPECT PREVAILING
NORTHERLY COLD-AIR DRAINAGE FLOW...JAMMING UP THROUGHOUT INTERIOR
VALLEYS /ESPECIALLY THE CT RIVER VALLEY/. 2M FORECASTED TEMPERATURES
TAKEN MAINLY FROM MESO-NAM/WRF-MODEL SOLUTIONS. THOUGH THE EASTERLY
ONSHORE FLOW WILL RESULT IN A FASTER TRANSITION OF PRECIPITATION
TYPES ACROSS EAST COASTAL PLAIN IN THE MORNING...EXPECTING A WINTRY
MIX TO LAST LONGER ACROSS THE INTERIOR INTO THE MIDDAY AND POSSIBLY
THE AFTERNOON HOURS. UPSTREAM TRENDS ACROSS INTERIOR MID-ATLANTIC
SHOW THIS PROCESS ALREADY ONGOING WHICH ADD FURTHER CONFIDENCE THAT
COLD-AIR DAMMING OVER THE INTERIOR WILL BE A BIG ISSUE AS TO WINTER
WEATHER OUTCOMES.
PRECIPITATION AND SNOW/ICE AMOUNTS REMAIN A CHALLENGE...AND LIKELY
THERE ARE ALWAYS SURPRISES IN STORE WITH SYSTEMS SUCH AS THESE.
CONSIDERING THE AFOREMENTIONED SPATIAL AND TEMPORAL CHALLENGES IN THE
PRECIPITATION TRANSITION...IMPACTING ACCUMULATIONS AT THE SURFACE...
ANOTHER POINT OF CONCERN IS UPON PRECIPITATION AMOUNTS. EVALUATING
THE ATMOSPHERE...FORCING IS MAINLY WITHIN LOW-LEVELS WITH LITTLE
INDICATION OF DEEP-LAYER ASCENT ALBEIT SOME BROAD-SCALE DIFFLUENCE
ALOFT. YET SREF V-WIND ANOMALIES AT H85 ARE +2 STANDARD-DEVIATIONS
AND NOTING UPSTREAM TRENDS OVER THE MID-ATLANTIC...THERE IS THE
DISTINCT POSSIBILITY FOR A MESO-SCALE BAND OF SNOW ACROSS SOUTHERN
NEW ENGLAND COLLOCATED WITH THE TIGHT H85 THERMAL GRADIENT WHERE
STRONG LOW-LEVEL CONVERGENCE IS MODELED TO LIFT THROUGH BETTER SNOW-
GROWTH REGIONS. THERE IS SOME SIGNAL WITHIN NEAR-TERM MESOSCALE
SOLUTIONS...ALBEIT CHAOTIC. IT IS ENTIRELY PLAUSIBLE TO SEE AREAS IN
PROXIMITY TO THE SOUTH-COAST OF SEEING A COUPLE OF INCHES OF SNOW IN
A SHORT PERIOD OF TIME DURING THE EARLY ONSET BEFORE TRANSITIONING
TO RAIN.
AS SUCH...WILL TAKE 1-2 INCH ACCUMULATIONS DOWN TO THE SOUTH-COAST.
WILL HAVE 2-4 INCHES FOR PORTIONS OF NORTH AND WEST MA AND SOUTHERN
NH. ICE ACCUMULATIONS UP TO A TENTH OF AN INCH EXPECTED ALONG AND
EAST OF THE EASTERN COASTAL PLAIN...EAST OF THE I-95/I-495 BELTWAY.
TOTAL LIQUID PRECIPITATION AMOUNTS AROUND 0.4 INCHES WITH THE
HEAVIEST AMOUNTS JUST OFF THE SOUTH-COAST.
EXPECT ACCUMULATIONS TO BEGIN THIS EVENING AND CONTINUE THROUGH THE
MORNING COMMUTE. WILL SEE A GRADUAL TRANSITION OF FROZEN P-TYPES
BACK INTO THE INTERIOR BEGINNING AROUND 6-8 AM...WITH LOCATIONS
ACROSS WESTERN AND NORTHERN MA AND SOUTHERN NH SEEING THE LONGEST
PERIOD OF A WINTRY MIX....EAST-COAST TRANSITIONING QUICKEST. HAVE
LENGTHENED THE WINTER- WEATHER ADVISORY FOR HARTFORD COUNTY CT
WITH THE EXPECTATION OF COLD-AIR DRAINAGE PROCESSES. IMPACTS IN
THE WINTER WEATHER ADVISORY...BUT IN BREVITY...EXPECT A MESSY
MONDAY MORNING COMMUTE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
HIGHLIGHTS...
* PERIOD OF LIGHT SNOW POSSIBLE SOUTH OF MA PIKE ON TUE
* MAINLY DRY AND UNSEASONABLY COLD WED THROUGH FRI
* LOW CONFIDENCE FORECAST NEXT WEEKEND
DETAILS...
MONDAY NIGHT...
OTHER THAN PERHAPS A LEFT OVER SPOT SHOWER IN THE EARLY EVENING...
DRY WEATHER EXPECTED. A COLD FRONT SWINGS THROUGH THE REGION EARLY
IN THE EVENING. TEMPS WILL ACTUALLY RISE ABOVE FREEZING ACROSS
PORTIONS OF THE INTERIOR THAT HAVE BEEN JAMMED IN SHALLOW COLD AIR
DURING THE DAY MONDAY. THE REASON FOR THIS IS THAT WARMER MID
LEVEL AIR WILL BE TEMPORARILY MIXED DOWN...AS WINDS SHIFT TO THE
WEST. THIS SHOULD ALLOW ANY LEFTOVER ICY CONDITIONS ON ROADWAYS TO
MELT. COLDER AIR WILL FINALLY BEGIN WORKING BACK INTO THE REGION
OVERNIGHT...WITH LOWS BY DAYBREAK BACK INTO THE 20S ACROSS THE
INTERIOR. THE COASTAL PLAIN SHOULD ONLY SEE LOWS REACH THE LOWER
TO MIDDLE 30S.
TUESDAY...
THE MAIN CONCERN IS THE CHANCES FOR A PERIOD OF LIGHT SNOW ON
TUESDAY...MAINLY SOUTH OF THE MA TURNPIKE. A WEAK WAVE OF LOW
PRESSURE WILL BE PASSING WELL TO OUR SOUTH...BUT AN APPROACHING
SHORTWAVE BACKS THE UPPER LEVEL FLOW. IT PLACES US UNDERNEATH A
POTENT JET STREAK WHICH RESULTS IN A PERIOD OF DECENT MID LEVEL
LIFT. WILL BE FIGHTING LOW LEVEL DRY AIR SO NOT EXPECTING A LOT OF
PRECIP...BUT A PERIOD OF LIGHT SNOW IS STILL POSSIBLE SOUTH OF MA
TURNPIKE ESPECIALLY NEAR THE SOUTH COAST. PERHAPS ITS MILD ENOUGH
FOR MIXED PRECIP AT THE ONSET ACROSS CAPE/ISLANDS...BUT SHOULD
TURN OVER TO ALL LIGHT SNOW. A COATING TO PERHAPS 1 INCH OF SNOW IS
POSSIBLE IN A FEW LOCATIONS. THERE ALSO IS A LOW PROBABILITY OF A BIT
MORE SNOW THAN THAT NEAR THE SOUTH COAST...BUT MOST GUIDANCE DOES NOT
SUPPORT THAT AT THIS TIME.
WEDNESDAY THROUGH FRIDAY...
NORTHWEST FLOW ALOFT WILL RESULT IN UNSEASONABLY COLD WEATHER FOR
SOUTHERN NEW ENGLAND. THERE ARE SOME MODEL DISCREPANCIES ON THE
TIMING OF REINFORCING SHOTS OF COLD AIR...HENCE UNCERTAINTIES ON
WHICH DAY WILL BE THE COLDEST. MAINLY DRY WEATHER DOMINATES OVER
THIS TIME PERIOD...BUT CAN/T RULE OUT A BRIEF PASSING FLURRY/SNOW
SHOWER WITH SOME MOISTURE STARVED NORTHERN STREAM ENERGY/FRONTAL
PASSAGES. IT ALSO WILL BE WINDY AT TIMES...SO IT CERTAINLY WILL
FEEL WINTERLIKE.
SATURDAY AND SUNDAY...
FORECAST CONFIDENCE IS VERY LOW OVER THIS TIME. THE ONE THING WILL
HAVE TO WATCH NEXT WEEKEND IS THE TRACK A WAVE OF LOW PRESSURE TO
OUR SOUTH. MOST MODELS SUGGEST THAT THE SYSTEM WILL PASS FAR
ENOUGH SOUTH TO SPARE OUR REGION OF SIGNIFICANT PRECIP.
HOWEVER...SOME MODELS SUGGEST THE LARGE HIGH TO OUR NORTH MAY
EVENTUALLY RESULT IN ONSHORE FLOW...BRINGING THE POTENTIAL FOR
SOME LIGHT WINTRY PRECIPITATION. OTHER GUIDANCE SUGGESTS SOUTHWEST
FLOW ALOFT MAY RESULT IN SOME OVER RUNNING PRECIPITATION. ALL IN
ALL...VERY LOW CONFIDENT FORECAST FOR NEXT WEEKEND.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /THROUGH TONIGHT/...
HIGH CONFIDENCE IN WIDESPREAD IFR CONDITIONS DEVELOPING AS PRECIP
MOVES ACROSS THE REGION. LOWER CONFIDENCE IN TIMING OF PTYPE
TRANSITIONS. EXPECT SNOW CHANGING TO SLEET/FZRA FROM SOUTH TO
NORTH THIS MORNING AND EVENTUALLY TO PLAIN RAIN IN THE COASTAL
PLAIN. INTERIOR TERMINALS WILL LIKELY HAVE TO DEAL WITH AN
EXTENDED PERIOD OF FREEZING RAIN/DRIZZLE INTO THE AFTERNOON.
MINOR SNOW ACCUM UP TO 2 INCHES POSSIBLE. CONDITIONS EXPECTED TO
IMPROVE TO VFR LATER TONIGHT.
KBOS TAF...HIGH CONFIDENCE IN MVFR/IFR DEVELOPING. LOW CONFIDENCE
IN TIMING OF PTYPE TRANSITIONS.
KBDL TAF...HIGH CONFIDENCE IN MVFR/IFR DEVELOPING. LOW CONFIDENCE
IN TIMING OF PTYPE TRANSITIONS.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
MONDAY NIGHT...MODERATE TO HIGH CONFIDENCE. LEFT OVER MVFR-IFR
CONDITIONS EARLY IN THE EVENING IMPROVE TO VFR BEHIND A COLD FRONT.
TUESDAY...LOW CONFIDENCE. A PERIOD OF MVFR-IFR CONDITIONS POSSIBLE
SOUTH OF THE MA TURNPIKE IN A ROUND OF LIGHT SNOW. OTHERWISE...VFR
CONDITIONS FOR THE REST OF THE TIME.
WEDNESDAY THROUGH FRIDAY...MODERATE TO HIGH CONFIDENCE. VFR
CONDITIONS DOMINATE WITH GUSTY WNW WINDS AT TIMES.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR-TERM /THROUGH MONDAY/...HIGH CONFIDENCE.
NORTHERLY WINDS OVER THE WATERS WILL VEER EAST-SOUTHEASTERLY WITH
TIME GUSTING 25 TO 30 KTS DURING THE DAY MONDAY AS AN AREA OF LOW
PRESSURE CROSSES INTO SOUTHERN NEW ENGLAND. WITH THE LOW/S PASSAGE
EXPECT WINDS TO BACK MORE SOUTHERLY.
PROLONGED PERIOD OF FETCH WILL RESULT IN SEAS OF 6 TO 8 FEET
ACROSS THE OUTER WATERS IMPACTING THE EAST- FACING ATLANTIC
BEACHES. SMALL CRAFT ADVISORIES IN EFFECT FOR ALL LOCATIONS EXCEPT
INNER BAYS.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...HIGH CONFIDENCE.
THE GENERAL IDEA IS THAT THE PASSAGE OF A COUPLE OF STRONG COLD
FRONTS WILL RESULT IN PERSISTENT WEST TO NORTHWEST WINDS OVER THIS
TIME. GIVEN THE STRONG COLD ADVECTION OVER THE WATERS...SCA WIND
GUSTS ARE EXPECTED OVER MUCH OF THIS TIME PERIOD OVER THE OPEN
WATERS. WE MAY EVEN SEE A BRIEF GALE FOR A TIME ON WEDNESDAY. THERE
ALSO WILL BE LULLS IN THE WIND...BUT TIMING THAT THIS FAR OUT IS
IMPOSSIBLE.
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
CTZ002.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
CTZ003-004.
MA...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
MAZ002>004-008>011-026.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MAZ005-012>014-017.
NH...WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR
NHZ011-012-015.
RI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
RIZ001>004-006.
MARINE...SMALL CRAFT ADVISORY FROM 4 AM EARLY THIS MORNING TO 10 PM EST
THIS EVENING FOR ANZ231>234.
SMALL CRAFT ADVISORY UNTIL 7 AM EST TUESDAY FOR ANZ235-237-
254>256.
SMALL CRAFT ADVISORY FROM 7 AM THIS MORNING TO 7 AM EST
TUESDAY FOR ANZ250-251.
&&
$$
SYNOPSIS...FRANK/SIPPRELL
NEAR TERM...KJC
SHORT TERM...SIPPRELL
LONG TERM...FRANK
AVIATION...KJC/FRANK
MARINE...FRANK/SIPPRELL
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1155 PM EST SUN DEC 8 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 400 PM EST SUN DEC 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS MOVING THROUGH
SE CO. AT THE SFC...LIGHT WINDS PREVAILED ACROSS UPPER MICHIGAN AS
ARCTIC HIGH PRES EXTENDED FROM NEW ENGLAND INTO THE NRN GREAT LAKES.
A LOW PRES TROUGH STRETCHED FROM SW KS THROUGH THE OH VALLEY. A
BROAD AREA OF LIGHT SNOW SUPPORTED BY WAA/280K-290K ISENTROPIC
LIFT...HAD SPREAD FROM MN/IA/WI INTO UPPER MI. HOWEVER...SNOW HAS
BEEN VERY LIGHT WITH VSBY TO 2-4SM FROM MNM-ESC AND ABOVE 5SM FROM
IMT-IWD.
LATE THIS AFTERNOON AND TONIGHT...AS THE SHORTWAVE CONTINUES TO LIFT
TOWARD THE GREAT LAKES EXPECT THE SNOW INTENSITY TO SLOWLY INCREASE.
HOWEVER...WITH THE STRONGER 700-300 MB QVECTOR CONV REMAINING SOUTH
OF THE AREA AND ONLY 1-2 G/KG AVAILABLE...GOING QPF VALUES IN THE
0.08-0.20 RANGE REMAIN ON TRACK. EXPECT SLR VALUES FROM NEAR 20/1
SOUTH TO 15/1 NORTH AS THE DGZ IS DEEPER AND EXTENDS MORE FAVORABLY
INTO THE LAYER OF GREATER UPWARD MOTION OVER THE SOUTH COMPARED TO
THE SHALLOW DGZ FARTHER NORTH IN THE COLDER AIR.
SO...FCST SNOWFALL AMOUNTS OF AROUND AN INCH NORTH TO 1 TO 3 INCHES
SOUTH ARE INCLUDED. THE HIGHER RES MODELS SUGGEST THAT AN AREA OF
LOW LEVEL CONV OVER NRN LAKE MI AHEAD OF THE AREA OF STRONGER SE
WINDS MAY PUSH A BAND OF LAKE ENHANCED SNOW INTO LOCATIONS BORDER
THE BAY OF GREEN BAY AND LAKE MICHIGAN LATE THIS EVENING. SINCE THE
BAND IS EXPECTED TO BE TRANSIENT...ADDITIONAL SNOW AMOUNTS OF ONLY
AN INCH OR TWO ARE EXPECTED WITH THIS FEATURE. A PERIOD OF SRLY
WINDS INTO SCHOOLCRAFT COUNTY COULD ALSO BRING A PERIOD OF MODERATE
SNOW LATE TONIGHT.
MONDAY...THE FIRST OF SEVERAL EMBEDDED SHORTWAVE TROUGHS WITHIN THE
DEEP EASTERN CANADIAN TROUGH WILL BE PUSHING THROUGH THE AREA MONDAY
MORNING. THE NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE
WESTERN CWA BEHIND A COLD FRONT AT THE START OF THE PERIOD. 850 MB
TEMPS FALLING TO -21 TO -23C BY THE AFTERNOON COMBINED WITH
INVERSION HEIGHTS RISING TO 8K-10K FT AND UNIDIRECTIONAL WESTERLY
WINDS SHOULD RESULT IN FAVORABLE LOW LEVEL CONV AND POTENTIAL FOR A
DOMINANT LES BAND INTO THE NRN KEWEENAW PENINSULA. WITH THE PASSAGE
OF THE SHRTWV...EXPECT THAT THE WINDS WOULD EVENTUALLY
VEER...PUSHING THE BAND SLOWLY TO THE SOUTH FROM NEAR EAGLE RIVER TO
CALUMET/MOHAWK AND TO HOUGHTON IN THE AFTERNOON. SNOWFALL
ACCUMULATIONS WILL GREATLY DEPEND ON HOW THE HEAVIER BAND LINGERS IN
ANY ONE LOCATION...BUT 12 HOUR ACCUMULATIONS OF AT LEAST 8 INCHES
REMAIN POSSIBLE. IN ADDITION...BLUSTERY WEST WINDS OF 20-30MPH WITH
GUSTS OVER 35 MPH WILL PRODUCE CONSIDERABLE BLOWING AND DRIFTING
SNOW AND VERY LOW VSBY. HOWEVER...SINCE THE HIGHER RES MODELS STILL
SHOW DIFFERENCES IN HANDLING WHERE THE BAND WILL DEVELOP AND HOW
LONG IT WILL LINGER...THE WATCH WAS NOT UPGRADED AT THIS TIME.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 400 PM EST SUN DEC 8 2013
ELOGATED AREA OF UPPER LEVEL TROUGHING STRETCHES FROM SKANDINAVIA
AND FAR NORTHWEST RUSSIA ACROSS THE NORTH POLE AND ACROSS MUCH OF
EASTERN CANADA AND AS FAR SOUTH AS THE WESTERN PORTIONS OF THE
CONUS. CORE OF COLDEST AIR RESIDES FROM NORTHERN GREENLAND ACROSS
CNTRL CANADA AND INTO THE NORTHERN PLAINS. H85 TEMP THIS MORNING
AT KINL WAS -25C WHILE IT WAS -17C AT KGRB. DECENT AGREEMENT THAT
UPCOMING WEEK WILL REMAIN CHILLY AS UPPER TROUGH BECOMES MORE
CENTERED OVER HUDSON BAY ALLOWING MULTIPLE PUSHES OF ARCTIC AIR TO
SWEEP ACROSS NORTHERN PLAINS AND GREAT LAKES IN NW FLOW ALOFT.
STILL INDICATIONS THAT COLD STARTS TO RELAX NEXT WEEKEND AS
TROUGHING REORIENTS FROM NORTH POLE TO DAVIS STRAIT AND GREENLAND
WHICH ALLOWS FOR MORE OF A ZONAL WEST-NORTHWEST FLOW ALOFT ACROSS
THE CONUS BY MIDDLE OF THE MONTH.
FIRST CONCERNING THE LK EFFECT ON MONDAY NIGHT. INITIAL SHORTWAVE IN
NW FLOW CURRENTLY OVER NORTHERN SASKATCHEWAN AND MANITOBA SWEEPS
ACROSS LK SUPERIOR REGION MONDAY AFTN. EXPECT MINIMAL SYNOPTIC
SUPPORT FOR ANY SNOW AS PVA/Q-VECTOR CONVERGENCE AT H7-H5/H85-H7
STAYS OVER LK SUPERIOR AND MAINLY NORTH. SFC LOW MOVING THROUGH ON
MONDAY DEEPENS NORTH OF LK SUPERIOR TOWARD JAMES BAY BY MONDAY
EVENING AS RESULT OF PVA/COLD AIR ADVECTION. RESULT IS INCREASING
UNSTABLE WESTERLY LOW- LEVEL FLOW ACROSS LK SUPERIOR. NAM SOUNDINGS
INDICATE VERY UNSTABLE CONDITIONS AS SHORTWAVE HELPS RAISE INVERSIONS
TO OVER 7KFT WITH LAKE EQL/S OVER 13KFT AT CMX AND P59 AND STDM4.
SFC-925MB STEERING WINDS VARY ENOUGH DURING PERIOD OF MOST FAVORABLE
INSTABILITY/MOSITURE/CONVERGENCE TO PEG WHERE HEAVIEST SNOW WILL
OCCUR. HIGH RES MODELS DO DIFFER HERE SOMEWHAT...WITH THE 12Z
REGIONAL GEM KEEPING THE STRONGEST CONVERGENCE MAINLY ALONG THE
NORTHWEST SHORE OF THE KEWEENAW THROUGH LATE AFTN...WHILE LOCAL WRF
IS MORE ON THE SOUTHERN EDGE...SETTING UP DOMINANT BAND MAINLY TO
SOUTH OF HOUGHTON AND HANCOCK. NAM AND NCEP WRF-ARW/NMM NESTS KIND OF
IN BTWN THOSE IDEAS. GIVEN THE DEGREE OF OVERWATER INSTABILITY...
POTENTIAL CERTAINTY THERE FOR TOTAL SNOW MONDAY AFTN THROUGH MONDAY
EVENING TO EXCEED A FOOT...IF THE BAND CAN PERSIST IN ONE LOCATION
FOR A WHILE. AT THE LEAST...MOST AREAS WILL SEE BURSTS OF HEAVIER
SNOW ALONG WITH STRONG/GUSTY WEST WINDS TO 40 MPH AND A LOT OF
BLOWING SNOW AND POOR VSBY. IN THE HEAVIER SNOW BAND...WHITEOUTS MAY
OCCUR MONDAY AFTN INTO MONDAY EVENING.
COORD WITH SHORT TERM FORECASTER AND DECIDED TO LEAVE GOING LK
EFFECT SNOW WATCH. NOT REALLY A QUESTION IF HEAVY LES/BLSN WILL
OCCUR...BUT MORE ONE OF WHERE THAT STRONG CONVERGENCE BAND WILL
DEVELOP. WILL LET MID SHIFT TAKE ANOTHER CRACK AT PINNING DOWN
LOCATION OF THE HEAVIER SNOW BAND.
ATTN LATER MONDAY NIGHT WILL BE ON SHORTWAVE PUSHING IN ACROSS
NORTHERN PLAINS AND ASSOCIATED SFC TROUGH. FIRST IMPACT FM THIS
WAVE WILL BE TO BACK WINDS SW...ALLOWING MOST OF HEAVIER LK EFFECT
SNOW TO PUSH OUT OVER LK SUPERIOR OFF THE KEWEENAW PENINSULA...THUS
THE ENDING TIME OF LATE MONDAY EVENING FOR LAKE EFFECT SNOW WATCH.
RIGHT AS THE LK EFFECT DIMINISHES FOR A WHILE...STILL APPEARS THAT
LGT SYNOPTIC SNOW WILL IMPACT MUCH OF CWA MAINLY IN THE MORNING.
BRIEF NOTE ABOUT WIND CHILLS FOR MONDAY NIGHT...INCREASING CLOUDS
AHEAD OF THE SYSTEM LATER MONDAY NIGHT SHOULD ALLOW TEMPS TO BEGIN TO
RISE. HAVE MINS WELL BLO ZERO...EVEN LESS THAN 10 BLO THROUGH EARLY
MORNING...THEN WITH THE ARRIVAL OF CLOUDS AND MORE WIND...EXPECT
TEMPS TO RISE TOWARD ZERO BY DAYBREAK ON TUESDAY. WILL BE CLOSE CALL
ON WIND CHILL READINGS NEAR CRITERIA BUT TEMPS MAY WARM JUST ENOUGH
TO KEEP WIND CHILLS GREATER THAN 25 BLO. AT THE LEAST...WIND CHILLS
WILL STILL BE A RATHER CHILLY 10 TO 20 BLO FOR MAJORITY OF WEST HALF
OF UPR MICHIGAN.
AS SFC LOW STRENGTHENS...MOISTURE/TEMPERATURE ADVECTION AHEAD OF
WAVE MIGHT RESULT IN MORE WIDESPREAD SNOW OVER EASTERN CWA LATE
MORNING INTO EARLY AFTN...WHERE A FEW INCHES OF SNOW COULD OCCUR.
OTHERWISE...EXPECT LESS THAN 1 INCH FOR THE CWA FROM THE SYSTEM.
ONCE THE SHORTWAVE AND SFC LOW CROSS THE AREA...SFC TROUGH ELONGATES
ACROSS SOUTHERN HALF OF LK SUPERIOR AND EVENTUALLY INTO NORTHERN
TIER OF UPR MICHIGAN. RESULT WILL BE LK EFFECT...MOSTLY OF MODERATE
INTENSITY...FOR THE WNW-NW FLOW AREAS. MOST CONCENTRATED/HEAVIER
SNOW SHOWERS LIKELY FOR THE SNOWBELTS OF ONTONAGON COUNTY FROM WHITE
PINE TO ROCKLAND AND ALSO TO THE EAST OF MUNISING AND TO THE NORTH
OF NEWBERRY...INCLUDING GRAND MARAIS. PERSISTENT LK EFFECT SETUP
CONTINUES THROUGH MUCH OF WEDNESDAY WITH INVERSIONS 5-8KFT AND
MORE THAN SUFFICIENT OVER-WATER INSTABILITY AS H85 TEMPS ARE NEAR
-25C. GIVEN SUCH COLD TEMPS THOUGH...SNOW WILL BE VERY FINE AND
MAIN ISSUE IN THE LK EFFECT AREAS WILL BE POWDERY SNOW BEING BLOWN
AROUND BY GUSTY WINDS RESULTING IN BLSN/POOR VSBY. AWAY FM THE LK
EFFECT COLD AIRMASS FIRMLY ENTRENCHED. SOME AREAS OF WESTERN CWA MAY
NOT REACH ZERO ON WEDNESDAY AFTN.
ANOTHER SYSTEM APPROACHING IN THE ACTIVE NW FLOW ALOFT COMES IN BY
THURSDAY MORNING. WINDS SHOULD BACK ENOUGH SW TO PUSH MOST OF THE LK
EFFECT OFFSHORE EXCEPT OVER THE KEWEENAW. HIGH PRESSURE RIDGE IN
VCNTY FIRST PART OF WED NIGHT WITH SUCH COLD AIRMASS SUGGESTS THAT
MINS COULD BE VERY LOW. LOWERED TEMPS TOWARD COLDER MOS NUMBERS...AND
FURTHER TWEAKED COLD SPOTS IN THE INTERIOR TOWARD 20 BLO ZERO. MAY BE
SIMILAR SETUP TO MONDAY NIGHT/TUESDAY NIGHT WHERE TEMPS RISE LATE.
MAIN CHANGE BESIDES LOWERING TEMPS WAS TO LOWER WIND SPEEDS TOO AS
WINDS MAY TRY TO GO CALM WITH THE RIDGE AROUND TO START THE NIGHT.
THUS...MAY NOT SEE WIND CHILL ISSUES UNLESS THAT INCOMING SYSTEM
TRENDS STRONGER.
IN WAKE OF THAT SYSTEM...SFC TROUGH SINKS ACROSS LK SUPERIOR AND UPR
MICHIGAN WHICH TURNS WINDS MORE NNW/N LATER THURSDAY AND FRIDAY.
KEPT IDEA OF INCREASING POPS FOR LK EFFECT ALONG MUCH OF LK SUPERIOR
COMPARED TO CONSENSUS POPS. MODELS HINT THAT WARMER AIR COULD TRY TO
WORK IN BY NEXT WEEKEND...AT LEAST RELATIVELY WARMER...AS FLOW SHOWS
SIGNS OF TRYING TO BECOME MORE ZONAL. MORE WIDESPREAD AREA OF WARM
AIR ADVECTION SNOW MAY TRY TO DEVELOP CLOSE TO THE REGION ALONG
RETREATING ARCTIC AIRMASS. THOSE TYPE OF DETAILS WILL BE HANDLED BY
LOW CHANCE POPS FOR THE TIME BEING. TEMPS THOUGH WARMER WILL STILL
BE RUNNING BLO NORMAL THROUGH THE END OF THE EXTENDED.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1155 PM EST SUN DEC 8 2013
WIDESPREAD LIGHT SNOW WILL CONTINUE TONIGHT WITH MVFR/IFR CONDITIONS
CONTINUING OVERNIGHT. CONDITIONS SHOULD IMPROVE TO MVFR BY LATE
TONIGHT OR MON MORNING AT IWD AND SAW. LAKE EFFECT SNOW WITH VLIFR
VSBY IS EXPECTED AT CMX BY MID MORNING AS WINDS VEER TO THE WEST AND
BECOME GUSTY AND THIS WILL CONTINUE THROUGH THE REST OF THE TAF
PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES OF GALES. THE FIRST WILL PASS
SOUTHEAST OF UPPER MI MONDAY MORNING. BEHIND THIS TROUGH...WINDS
WILL VEER TO THE WEST AND INCREASE TO GALES TO 35 TO 40 KNOTS ACROSS
LAKE SUPERIOR MONDAY AFTERNOON AND EVENING. AFTER A DECREASE TO 20
TO 30 KNOT SOUTHWEST WINDS TUESDAY MORNING...LOW PRESSURE WILL TRACK
EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND PRODUCE ANOTHER ROUND
OF GALES TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON AND EVENING. THE
WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30 KNOTS FROM LATE
TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE EXTENDING FROM HIGH
PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS INTO THE AREA.
CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE POSSIBLE
THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR ACROSS THE
LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE SOUTHEASTWARD
ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WINDS SHOULD
REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 9 AM EST MONDAY FOR MIZ007-014-085.
LAKE EFFECT SNOW ADVISORY FROM 7 AM MONDAY TO 7 AM EST TUESDAY
FOR MIZ001-003.
WINTER WEATHER ADVISORY UNTIL 7 AM EST /6 AM CST/ MONDAY FOR
MIZ012-013.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM MONDAY TO 7 AM EST
TUESDAY FOR LSZ245-248>251-265>267.
GALE WARNING FROM 1 PM MONDAY TO 5 AM EST TUESDAY FOR LSZ244-245-
265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM EST /NOON CST/ MONDAY TO
7 AM EST /6 AM CST/ TUESDAY FOR LSZ162-240>244-263-264.
GALE WARNING FROM 4 PM MONDAY TO 5 AM EST TUESDAY FOR LSZ264.
GALE WARNING FROM 1 PM MONDAY TO MIDNIGHT EST MONDAY NIGHT FOR
LSZ263.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...JLA
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
1112 PM CST SUN DEC 8 2013
.SYNOPSIS...
ISSUED AT 326 PM CST SUN DEC 8 2013
H5 ANALYSIS FROM THIS MORNING HAS A HIGHLY AMPLIFIED
PATTERN ACROSS NOAM THIS MORNING WITH A RIDGE EXTENDING INTO THE
GULF OF ALASKA. A CLOSED LOW WAS OVER WESTERN PORTIONS OF THE HUDSON
BAY WITH A DEEP TROUGH OF LOW PRESSURE EXTENDING SSWD INTO THE
ROCKIES AND SWRN US. NUMEROUS EMBEDDED SHORTWAVES WERE NOTED ACROSS
THE WESTERN CONUS THIS MORNING. THE FIRST OVER SWRN WYOMING...WHICH
IS CROSSING CENTRAL COLORADO AND IS EMERGING ONTO THE FRONT RANGES
JUST SOUTH OF DENVER...PER SATELLITE AND RADAR IMAGERY. ANOTHER
SHORTWAVE WAS LOCATED OVER SWRN SASKATCHEWAN AND SRN ALBERTA...AND A
THIRD WAS NOTED OFF THE NRN CALIFORNIA COAST. AT THE SURFACE...AN
AREA OF SNOW IN ASSOCIATION WITH THE FIRST SHORTWAVE...EXTENDED FROM
AROUND LIMON COLORADO...NEWD TO FAR SOUTHWESTERN NEBRASKA. THE
HEAVIEST SNOW PER RADAR IMAGERY EXTENDED FROM NEAR LIMON COLORADO TO
NEAR IMPERIAL. THIS ACTIVITY HAS BEEN MOVING TO THE EAST NORTHEAST
AND IS EXPECTED TO REMAIN MAINLY SOUTH OF THE FORECAST AREA THIS
AFTERNOON. THE EXCEPTION IS ACROSS THE FAR SOUTHWESTERN COUNTIES
WHERE 1 TO 2 INCHES IS POSSIBLE THIS AFTERNOON. ELSEWHERE...ANY
ACCUMULATIONS ARE EXPECTED TO BE AN INCH OR LESS. AS OF 3 PM
CST...UNDER PARTLY TO MOSTLY CLOUDY SKIES...TEMPERATURES RANGED FROM
11 AT VALENTINE TO 17 AT OGALLALA.
&&
.UPDATE...
ISSUED AT 729 PM CST SUN DEC 8 2013
THE RAP AND HRRR TEMPERATURE AND WIND CHILL FORECASTS APPEAR TO BE
ON TRACK WITH KVTN SHOWING A WIND CHILL OF -26F AT 7 PM CST.
THERE ARE SOME MID CLOUDS MOVING IN FROM WY WHICH WILL LIMIT THE
AMOUNT OF TIME FOR RADIATIONAL COOLING. THUS CONDITIONS ARE NOT
FAVORABLE FOR ROCK BOTTOM LOWS BUT -10F TO -20F SHOULD DEVELOP
ALONG AND WEST OF HIGHWAY 83 TONIGHT.
TEMPS HAVE BEEN LOWERED IN THE NORTH AND A WIND CHILL WARNING IS
IN PLACE FROM VALENTINE WEST TO GORDON.
&&
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 326 PM CST SUN DEC 8 2013
SHORT WAVE MOVING ACROSS THE NEB/KS BORDER...WHICH MODELS HAVE
HANDLED FAIRLY WELL. LIGHT SNOW WILL BE TAPERING TO FLURRIES ACROSS
PORTIONS OF SOUTHWEST AND CENTRAL NEBRASKA BEFORE ENDING LATER THIS
EVENING. ADDITIONAL SNOWFALL COULD REACH UP TO THREE QUARTERS OF AN
INCH...HOWEVER MOST AREAS IN THE SE CWA TO SEE A COUPLE OF TENTHS.
CLEARING SKIES ARE ALREADY SEEN ON VISIBLE SAT ACROSS THE PANHANDLE
AND NW NEB. HIGH PRESSURE WILL BEGIN TO NOSE DOWN INTO THE AREA
TONIGHT...WHICH WILL COMBINE WITH THE SNOW PACK TO ALLOW FOR GOOD
RADIATIONAL COOLING. RECENT LOWS HAVE BEEN BELOW GUIDANCE WHEN SKIES
HAVE CLEARED...SO TOOK COOLER MAV GUIDANCE AND DROPPED A COUPLE OF
DEGREES...WHICH MAYBE CONSERVATIVE FOR PORTIONS OF THE NW
CWA...WHERE MORE THAN HALF A FOOT OF SNOW REMAINS ON THE GROUND.
THIS PLACES LOWS IN THE -5 TO -15 DEGREE RANGE. NORTHWEST WINDS
MOVING IN WITH THE CLEARING...ALTHOUGH THEY WILL BE DIMINISHING. THE
COMBINATION OF LIGHT WINDS AND BITTER COLD TEMPS WILL ALLOW FOR WIND
CHILLS TO FALL INTO THE -20 TO -30 RANGE...LOCALLY LOWER ACROSS NW
ZONES. WILL GO WITH A WIND CHILL ADVISORY FOR ENTIRE CWA.
TOMORROW MODELS HOLD 850 MB TEMPS FAIRLY STEADY...AND WITH MOSTLY
SUNNY SKIES EXPECT HIGHS TO REBOUND A LITTLE WARMER THAN
TODAY...HIGHS SHOULD REBOUND INTO THE TEENS TO NEAR 20.
.LONG TERM...(MONDAY NIGHT THROUGH SUNDAY)
ISSUED AT 326 PM CST SUN DEC 8 2013
MONDAY NIGHT THROUGH WEDNESDAY...THE MAIN FORECASTING
CHALLENGES ARE TEMPERATURES...THEN LOW PRECIPITATION CHANCES FOR
TUESDAY NIGHT. ON MONDAY NIGHT...A SURFACE TROUGH OF LOW PRESSURE
WILL TRACK FROM THE CENTRAL PLAINS EAST INTO THE UPPER MIDWEST.
LIMITED CAA WILL ACCOMPANY PASSAGE OF THE TROUGH. HOWEVER...IT WILL
HELP TO KEEP THE LOW LEVEL WINDS MIXED ON MONDAY NIGHT...THUS MILDER
TEMPERATURES ARE EXPECTED. ALBEIT...LOWS WILL STILL BE COLD WITH
READINGS IN THE SINGLE DIGITS. ON TUESDAY...WESTERLY DOWNSLOPE WINDS
WILL CONTINUE INCREASE SOMEWHAT TO 10 TO 15 MPH. DECIDED TO UNDERCUT
GUIDANCE FOR HIGHS TUESDAY...BASED ON SNOW COVER AND LIMITED MIXING
POTENTIAL. THIS LED TO HIGHS MAINLY IN THE 20S...WITH SOME TEMPS
NEAR THE FREEZING MARK ACROSS THE FAR SOUTHWEST. ON TUESDAY
NIGHT...AN ARCTIC COLD FRONT WILL BACK INTO NORTHERN AND
NORTHEASTERN NEBRASKA WITH A NICE PV MAX ARRIVING OVERNIGHT. CROSS
SECTIONS ACROSS NORTHERN NEBRASKA ARE INDICATIVE OF SOME WEAK LIFT
IN THE DENDRITIC LAYER WHICH MAXES OUT AROUND 06Z WEDNESDAY. TOP
DOWN SATURATION WILL HAVE TO OCCUR WITH ANY PCPN WHICH MAY FALL...SO
WILL LIMIT POP MENTION TO SLIGHTS FOR NOW...AND KEEP POPS ACROSS THE
NRN CWA AS CROSS SECTIONS NEVER MOISTEN UP ACROSS THE SRN CWA. ON
WEDNESDAY SURFACE HIGH PRESSURE WILL BUILD INTO THE MID MISSOURI
VALLEY. WINDS WILL SHIFT TO THE SOUTHWEST DURING THE AFTERNOON
HOURS...AND WILL RECYCLE COLD AIR ACROSS THE FORECAST AREA. HIGHS
WILL BE COLD...RANGING FROM THE MIDDLE TEENS IN THE NORTHEAST...TO
THE UPPER 20S IN THE FAR SOUTHWEST.
WEDNESDAY NIGHT THROUGH SUNDAY...THE MID RANGE MODEL SOLUTIONS
CONTINUE TO INDICATE LOW AMPLITUDE WEST NORTHWESTERLY FLOW ACROSS
THE CONUS FOR THE END OF THE WEEK INTO EARLY NEXT WEEK. BOTH THE
ECMWF AND GFS SOLNS ARE TRENDING TOWARD THE DEVELOPMENT OF AN UPPER
LEVEL TROUGH EMBEDDED IN THE SRN STREAM TOWARD FRIDAY. BOTH SOLNS
LIFT THIS ENERGY SOUTH OF THE AREA...SO A DRY FORECAST CONTINUES.
AFTER TEMPERATURES TREND HIGHER FOR THURSDAY AND FRIDAY WITH HIGHS
IN THE 30S...COOLER TEMPERATURES WILL ARRIVE ON FRIDAY NIGHT AS AN
ARCTIC COLD FRONT BACKS INTO THE FORECAST AREA. HIGHS WILL BE COOLER
IN THE 20S AND LOWER 30S SATURDAY...FOLLOWED BY 30S AND LOWER 40S FOR
SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1112 PM CST SUN DEC 8 2013
VFR IS EXPECTED ALL AREAS TONIGHT THROUGH MONDAY EVENING. SCATTERED
TO BROKEN COVERAGE OF MID AND HIGH LEVEL CLOUDS WILL CONTINUE
ACROSS THE FCST AREA DURING THIS PERIOD.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL NOON CST /11 AM MST/ MONDAY FOR NEZ007-
009-010-022>029-035>038-056>059-069>071.
WIND CHILL WARNING UNTIL NOON CST /11 AM MST/ MONDAY FOR
NEZ004>006-008-094.
&&
$$
UPDATE...CDC
SYNOPSIS...CLB
SHORT TERM...MASEK
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
116 AM EST MON DEC 9 2013
.SYNOPSIS...
A SYSTEM WILL BRING A ROUND OF LIGHT FREEZING DRIZZLE TONIGHT
THROUGH MORNING. MONDAY NIGHT THROUGH THURSDAY...ARCTIC AIR WILL
WORK INTO THE AREA. THIS WILL INCLUDE DEVELOPING ACCUMULATING
LAKE EFFECT SNOW SHOWERS EAST OF THE GREAT LAKES.
&&
.NEAR TERM /THROUGH TODAY/...
1150 PM UPDATE...A QUICK UPDATE TO WX GRIDS AS FREEZING
PRECIP/SLEET ALREADY OCCURRING ACROSS NE PA AND PARTS OF THE
SOUTHERN TIER. THIS TRANSITION TO LIGHT FREEZING RAIN AND SLEET
WILL RAPIDLY SPREAD NORTH ACROSS THE NRN CWA DURING THE NEXT
SEVERAL HOURS AS MODEL SOUNDINGS CONTINUE TO INDICATE MOISTURE TOO
SHALLOW FOR A DENDRITE ZONE. ALSO, DUE TO A LACK OF SIGNIFICANT
LIFT DYNAMIC COOLING IS ALSO ABSENT. MOST AREAS WILL SEE LITTLE OR
NO SNOWFALL PERHAPS AN INCH OVER NRN/ERN PTN OF FA. ALL AREAS WILL
HAVE ICE ACCUMS UP TO ONE TENTH OF AN INCH WHICH WILL MAKE THE
MORNING COMMUTE DIFFICULT.
1005 PM UPDATE...
HV DELAYED PCPN FURTHER BY SVRL HRS AS NEPA IS SEEING VRY LITTLE
PCPN ATTM, THO SRN TIER IS SEEING FLURRIES. KBUF 00Z RAOB STILL
SHOWING DRY AIR IN THE LOWEST 200MB AND THIS IS BEING CONFIRMED BY
OBS ACRS THE REGION. EMPHASIS NOW TURNS TO FRZG PCPN DRG THE
OVRNGT HRS AS SNOW/SLEET DOES NOT APPEAR TO BE THE BIG CONCERN.
ATMOS LOSES MOISTURE IN THE DENDRITE ZONE TONIGHT AS MOISTURE IN
THE AREA IS GETTING THE SQUEEZE PLAY BTWN THE COASTAL LOW AND
GREAT LKS LOW. THUS, HV UPDATED TO GO FRZG DRIZZLE AREAWIDE FOR
TONIGHT WITH A GLAZE OF ICE EXPECTED BY MRNG. THUS WL KEEP THE
ADVISORY GOING AS TEMPS RMN BLO FRZG AND ONLY VRY LGT QPF
EXPECTED.
PREV DISCUSSIONS BLO...
630 PM UPDATE...
PRECIP IS TAKING QUITE AWHILE TO MV INTO FA AS IT SLOWLY WORKS ITS
WAY THRU PA. ACRS NEPA, OBS ARE STILL REPORTING CIGS RANGING FM
6-10KFT AND HIGHER ACRS CNTRL NY. 18Z RAOB OUT OF KBUF SHOWING THE
LOWEST 300MB STILL DRY, HELPING TO EVAPORATE QPF AS IT HEADS NWRD.
APPEARS AS THO 18Z GFS BUFKIT SNDGS HV A BETTER HANDLE ON LOW-LVL
DRY AIR WITH BLYR AT KAVP RMNG TOO DRY FOR SNOW THRU 00Z, WHEREAS
NAM, RAP AND ARW SNDGS INDICATING SNOW SHUD HV BEEN FALLING FOR
THE LAST SVRL HRS DOWN ACRS NEPA.
THUS HV BACKED OFF ON POPS FOR EARLY THIS EVNG WITH CHC LIGHT SNOW
IN NEPA NOT MVG IN FOR ANOTHER FEW HRS, SOMEWHERE BTWN 01Z AND
02Z. THIS AREA OF LIGHT SNOW WL GRADUALLY SPREAD NORTH MVG INTO
SRN TIER BY 03Z AND OVRSPRD RMNDR OF THE AREA BY 06Z. QPF AMNTS
EXPECTED TO BE VRY LGT WITH QPF TOTALS THRU MRNG < 0.10 INCHES.
EXPECT SNOW TO CONT ACRS ENTIRE CWA THRU 06Z (A TAD LATER THAN
PREVIOUSLY THOUGHT) BFR GRADUALLY MIXING WITH SLEET AND EVENTUALLY
-FZRA/-FZDZ TWD DAYBREAK. EXPECT SNOW TO HANG ON LONGEST OVR NRN
ONEIDA CNTY WHERE COLD AIR WL BE DEEPEST. HAVING SAID ALL THIS
EXPECT JUST 1-2 INCHES OF SNOW AND SLEET ACCUMS, HIGHEST OVR EXTRM
ERN SXNS FM MOHAWK VLY DOWN THRU WRN CATS. APPEARS LKLY THAT ALL
AREAS WL SEE A GLAZE OF ICE BY MRNG, MAKING FOR HAZARDOUS TRAVEL
DRG THE MRNG COMMUTE.
315 PM UPDATE...
DOUBLE LOW SYSTEM...YET WE ARE IN BETWEEN...WITH ONE CENTER BY THE
NORTHERN GREAT LAKES AND THE OTHER OFFSHORE OF NEW JERSEY. FORCING
WITH THE SOUTHERN LOW HAS YIELDED A BAND OF HEAVY SNOW IN
SOUTHEAST PA THROUGH NJ...AS ANYONE WATCHING THE PHILADELPHIA
PRO FOOTBALL GAME CAN ATTEST. WE WILL STILL GET A PIECE OF THE
SYSTEM...WITH TOP DOWN MOISTENING YIELDING A BATCH OF SNOW THIS
EVENING SPREADING FROM SOUTHWEST TO NORTHEAST. HOWEVER...SHORTLY
AFTER SNOW ARRIVES...SATURATED LAYER BECOMES SHALLOW TO POINT THAT
TEMPERATURES WITHIN IT BECOME UNSUPPORTIVE OF ICE CRYSTAL
FORMATION...SO QUICK SOUTH-TO-NORTH TRANSITION TO WINTRY MIX OF
LIGHT SLEET AND FREEZING RAIN/DRIZZLE IS FORESEEN OVERNIGHT INTO
EARLY MONDAY...AND EVENTUALLY PLAIN RAIN/DRIZZLE DURING THE DAY
MONDAY.
WINTER WEATHER ADVISORY FOR ENTIRE AREA STILL LOOKS GOOD YET AS
PREVIOUSLY ADVERTISED THIS WILL DEFINITELY BE A LIGHT
PRECIPITATION EVENT. IT HAPPENS TO INCLUDE LIGHT FREEZING
RAIN/FREEZING DRIZZLE AND THUS THE POTENTIAL FOR HAZARDOUS TRAVEL
CONDITIONS ON UNTREATED ROADS...NECESSITATING THE ADVISORY. ONLY
FIGURING ON AN INCH OR LESS OF SNOW- SLEET ACCUMULATION /PERHAPS
CLOSER TO 2 INCHES IN CATSKILLS TO ONEIDA COUNTY/...AND UP TO A
TENTH OF AN INCH OF ICE ACCUMULATION...MOST PLACES LESS.
NON-DIURNAL TEMPERATURES TONIGHT...SLOWLY CLIMBING FROM UPPER 20S
THROUGH LOW 30S INTO MONDAY MORNING...EVENTUALLY REACHING HIGHS OF
MID 30S TO LOW 40S DURING THE DAY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
130 PM UPDATE...
COLD AIR ADVECTION WILL DOMINATE THE SHORT TERM PERIOD...AS WELL
AS DEVELOPMENT OF WESTERLY-FLOW LAKE EFFECT SNOW FOR SOME.
DEPARTURE OF SYSTEM WELL TO OUR NORTHEAST...AS WELL AS SHALLOW
MOISTURE PROFILE AND WEST-SOUTHWEST FLOW...WILL KEEP THINGS FAIRLY
QUIET MONDAY NIGHT. INTO TUESDAY THOUGH...850MB TEMPERATURES WILL
DIP INTO THE LOWER TO MID TEENS BELOW ZERO CELSIUS WHILE INVERSION
WILL RISE TO DENDRITIC GROWTH LAYER...BEGINNING TO INITIATE BETTER
LAKE RESPONSES. NOT EXPECTING HEAVY ACCUMULATIONS TUESDAY ITSELF
WITH WSW FLOW KEEPING LAKE ONTARIO BAND MAINLY NORTH...YET PERHAPS
STILL SKIMMING NORTHERN ONEIDA COUNTY. HOWEVER...LAKE ERIE BAND
MAY ACTUALLY STRETCH WELL EAST INTO AT LEAST SOUTHERN TIER-FINGER
LAKES FOR AT LEAST SCATTERED SNOW SHOWERS AND PERHAPS BRIEF
HEAVIER BURSTS.
LAKE EFFECT CONTINUES TO BE FAVORABLE TUESDAY NIGHT INTO
WEDNESDAY...AS 1000-500MB THICKNESSES DROP FURTHER INTO THE MID
510S TO LOWER 520S DECAMETER RANGE. HIGHS WEDNESDAY ONLY 20S
AREAWIDE.
MODEL SOUNDINGS SUGGEST DENDRITIC GROWTH TEMPERATURES
DOMINATING THE 3-7 KFT AGL LAYER. PASSING SHORTWAVES THOUGH WILL
FLUCTUATE LOW LEVEL WINDS...WHICH WILL PUSH THE BANDS AROUND AND
ALSO COULD MIS ALIGN WINDS IN THE LOWEST LEVELS. WE WILL HAVE TO
WATCH NORTHERN ONEIDA COUNTY CLOSELY IN MODEL TRENDS FOR POTENTIAL
OF GETTING INVOLVED IN LAKE PROLIFIC ONTARIO SNOW BAND...WHICH
MUCH IF NOT MOST OF THE TIME WILL REMAIN JUST TO THE NORTH.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
215 PM EST UPDATE...
A VERY ACTIVE WEATHER PATTERN IS EXPECTED IN THE EXTENDED
FORECAST. MINOR ADJUSTMENTS WERE MADE TO THE PREVIOUS FORECAST AND
LEANED TOWARDS WPC GUIDANCE. VERY BROAD UPPER LEVEL LOW WILL
SLOWLY DRIFT NORTH AND EAST OF THE REGION RESULTING IN A MUCH
COOLER AIR MASS OVER THE REGION... THUS LE SNOW SHOWERS WILL BE
POSSIBLE THROUGH FRIDAY FOR CENTRAL NY. HIGH PRESSURE WILL BUILD
ACROSS NEW ENGLAND THIS WEEKEND WHICH WILL HELP TEMPS CREEP CLOSER
TOWARDS 32. WITH LARGE DIFFERENCE WITHIN GFS/ECMWF INTO THE
WEEKEND KEPT PREVIOUS FORECAST WITH A SLIGHT CHANCE FOR SNOW
SHOWERS.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
1230 PM UPDATE...
LIGHT PRECIP WILL CONTINUE THIS MORNING. CIGS WILL FALL FROM
MOSTLY MVFR TO IFR AT ALL BUT SYR AND ELM BY 15Z. SOME IFR CIGS
ALREADY AT BGM AND AVP WHICH SHOULD CONTINUE FOR THE MOST PART.
MUCH OF THE SNOW WILL BE LIGHT ENOUGH THAT VSBYS WILL STAY MVFR.
THE SNOW WILL CHANGE TO SLEET THEN TO FREEZING DRIZZLE. AMOUNTS
WILL BE LIGHT WITH QPF PROBABLY UNDER A TENTH OF AN INCH.
TEMPERATURES SLOWLY RISE THIS MORNING SO THAT PLAIN RAIN AND
DRIZZLE BETWEEN 12 AND 16Z. FIRST WILL BE AVP AND LAST RME TO
CHANGE. VSBYS SHOULD IMPROVE TO VFR AS PRECIP ENDS AROUND 16Z BUT
CIGS WILL REMAIN IFR/MVFR UNTIL 19 TO 00Z THEN IMPROVE TO
VFR/MVFR. STAYING THAT WAY THIS EVENING.
SE WINDS AT 5 TO 10 KTS WILL SHIFT TO SSW MIDDAY THEN TO W LATE
AFTN.
OUTLOOK...
MON OVERNIGHT... MVFR/VFR.
TUE/WED/THU...SCT MVFR SYR/RME IN LAKE EFFECT SNOW SHOWERS. VFR
ELSEWHERE.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
PAZ038>040-043-044-047-048-072.
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST THIS MORNING FOR
NYZ015>018-022>025-044-045-055-056-062.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
NYZ009-036-037-046-057.
&&
$$
SYNOPSIS...MDP/PVN
NEAR TERM...MDP/PVN/RRM
SHORT TERM...MDP
LONG TERM...KAH
AVIATION...DJN/TAC
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
504 AM EST MON DEC 9 2013
.SYNOPSIS...
A LOW PRESSURE WAVE CROSSES TODAY. A WEAK SYSTEM CROSSES LATE
TONIGHT INTO TUESDAY WITH SOME SNOW EXPECTED. CHILLY DRY HIGH
PRESSURE FOR WEDNESDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MAINLY ZONAL FLOW WILL PREVAIL TODAY...WITH AREAS OF CLEARING
SPREADING FROM WEST TO EAST. MODELS SHOW AN MID TO UPPER AIR VORT
MAX ASSOCIATED WITH AN H5 SHORTWAVE CROSSING THE AREA BY 18
TUESDAY.
LATEST RADAR IMAGES SHOW A BAND OF RAIN SHOWING SIGNS OF BREAKING
UP WITH RAIN DIMINISHING IN INTENSITY. WITH SATURATED
TERRAIN...KEPT FLOOD WATCH FOR THE WESTERN SLOPES OF WV...SOUTHWEST
VA AND SOUTHERN COAL FIELDS AS SOME DECENT PRECIPITATION AMOUNTS...0.5
TO 0.75 INCHES IN 6 HOURS HAVE BEEN REPORTED.
WINTER WEATHER ADVISORIES REMAIN IN EFFECT FROM RALEIGH...NORTH TO
WEBSTER FOR FREEZING RAIN AND SNOW...WHILE WINTER STORM WARNING
REMAINS IN EFFECT FOR POCAHONTAS AND RANDOLPH COUNTIES THROUGH 12Z
MONDAY.
WARM ADVECTION SHOULD CONTINUE THROUGH THE NIGHT...SO HAVE NON-
DIURNAL TEMPERATURES...BASED HEAVILY ON THE RAP AND WRF GUIDANCE.
WENT WITH THE WRF AND THE GFS GUIDANCE FOR TEMPERATURE THROUGH THE
PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ACTIVE AT THE OUTSET OF THE PERIOD ON TUESDAY MORNING WITH A
QUICK-HITTING SYSTEM PUSHING ACROSS THE AREA. YET ANOTHER WAVE OF
LOW PRESSURE WILL BE RIDING ALONG THE QUASI-STATIONARY FRONT STILL
TO OUR SOUTHEAST WHICH IS PROGGED TO BE LOCATED NEAR THE TN/NC/GA
AREA AT 12Z TUE. MEANWHILE AN UPPER TROUGH WILL BE PROGRESSING
EASTWARD QUICKLY ACROSS THE LOWER/MID OHIO RIVER VALLEY TUE MORNING.
EXPECT TWO DISTINCT AREAS OF PRECIP AT THE OUTSET...ONE ENTERING THE
SE OHIO ZONES AND THE OTHER PUSHING UP FROM THE SW WITH THE SFC LOW.
THESE SHOULD MERGE OVER THE NORTHEAST ZONES BY MID-LATE MORNING ON
IT/S WAY OUT OF OUR AREA. VARIOUS QPF OUTPUT DEPICTING ROUGHLY
0.1-0.2 INCHES IN GENERAL...WITH SOME HIGHER AMOUNTS PARTICULARLY ON
THE FINER RESOLUTION NAM12. TOUGH CALL ON SNOWFALL AMOUNTS WITH SOME
DIFFERENCES IN TIMING OF THE HIGHEST QPF AND WITH THE SYSTEM BEING
SUCH A FAST-MOVER. A GENERAL INCH OR SO APPEARS REASONABLE FOR MUCH
OF THE LOWLANDS LATE MON NIGHT GOING INTO TUE MORNING. THE AREA
HOWEVER COMES UNDER INFLUENCE OF RIGHT ENTRANCE REGION OF STRONG JET
JUST TO OUR NORTHWEST AROUND THE 12Z TUE TIME FRAME WITH GOOD
UNIDIRECTIONAL SPEED SHEAR. A BIT CONCERNED WITH PROGGED EPV AND
THETA-E LAPSE RATE VALS WITH GOOD SATURATION ABOVE THE COLD
DOME...NOT TO MENTION SOME WEAK ELEVATED CAPE...THAT SOME LOCATIONS
MAY SEE SOME ENHANCEMENT OF SNOWFALL RATES/ACCUMULATIONS IN NARROW
MESOSCALE BANDS THROUGH SLANTWISE AND/OR UPRIGHT CONVECTION.
CONSIDERED AN ADVISORY FOR TUE MORNING...BUT AFTER COLLABORATION
WITH SURROUNDING OFFICES DECIDED TO ALLOW DAY SHIFT ONE MORE LOOK AT
LATEST DATA. DID BUMP UP SNOW AMOUNTS...AGAIN...TO AROUND THE 1-2
INCH RANGE WITH SOME 2-3 ACROSS THE NORTHEAST ZONES. SNOWFALL WILL
PRIMARILY BE CONFINED NEAR THE EASTERN MOUNTAINS BY 18Z TUE WITH
ONLY A SLIGHT CHANCE OF LIGHT SNOW REMAINING BY 00Z WED. ALSO NUDGED
MAX TEMPS DOWN A BIT TUESDAY PER LATEST MOS GUIDANCE AND 925MB TEMPS
SUPPORTING. MANY LOCATIONS TUESDAY WILL STRUGGLE TO REACH THE
FREEZING MARK.
HIGH PRESSURE PUSHES IN FROM THE WEST TUESDAY NIGHT AND WEDNESDAY
WITH RAPIDLY CLEARING SKIES TUESDAY NIGHT WITH HIGH PRESSURE CENTER
LOCATED OVER THE SOUTHERN ZONES BY 12Z WED. CLEARING SKIES AND LIGHT
WINDS WILL ALLOW GOOD COOLING WITH TEENS EXPECTED FOR MOST
LOCATIONS...AND EVEN SOME SINGLE DIGITS POSSIBLE OVER SE OHIO AND OF
COURSE THE EASTERN HIGH COUNTRY. AN UPPER TROUGH WILL PASS BY TO THE
NORTH OF THE FORECAST AREA WEDNESDAY RESULTING IN PERHAPS A FEW MORE
CLOUDS NORTH. BUT OTHERWISE A DRY AND SUNNY...BUT COOL...DAY IS ON
TAP FOR WEDNESDAY. MAX TEMPS GENERALLY IN THE LOW/MID 30S FOR THE
LOWLANDS STILL APPEAR ON TRACK WITH VERY LITTLE CHANGE FROM PREV
FCST. SFC WINDS WILL COME AROUND TO THE SOUTHWEST AS SFC HIGH
CONTINUES TO PUSH OFF TO THE EAST. A QUICK MOVING FRONT WILL PUSH
ACROSS THE AREA WED NIGHT...BUT LITTLE MOISTURE WITH IT RESULTS IN
ONLY A BRIEF INCREASE IN CLOUD COVER AND SOME BREEZY POST-FRONTAL
WINDS WED NIGHT...EXCEPT FOR THE FAR NORTHEAST ZONES WHERE JUST
ENOUGH MOISTURE DEPTH MAY BE ENOUGH TO SQUEEZE OUT A LIGHT SNOW
SHOWER. THUS WILL CARRY SLIGHT CHANCE POPS HERE WED NIGHT. SNOW
ACCUMS WILL NOT BE AN ISSUE HOWEVER...WITH ONLY A DUSTING TO A FEW
TENTHS POSSIBLE. MINS AGAIN WILL BE JUST ABOUT IDENTICAL TO TUE
NIGHT/S...WITH TEENS EXPECTED FOR MOST LOWLANDS AND PERHAPS LOWER
20S FOR THE COALFIELDS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
STILL JUST WHAT THE DOCTOR ORDERED. A MOSTLY DRY PATTERN
WEDNESDAY NIGHT INTO SATURDAY. HAVE A SLIGHT CHANCE OF SOME
LIGHT SNOW SHOWERS WEDNESDAY NIGHT ACROSS THE NORTHERN WV
MOUNTAINS.
DRY AIR AND THE LONG DECEMBER NIGHTS YIELDS COLD DAWN TEMPERATURES.
DOWN THE ROAD...MOISTURE INCREASES SATURDAY...HAVE SOME CHANCE POPS
BY SATURDAY FOR RAIN AND SNOW. STILL APPEARS NOT A HEAVY EVENT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
PERHAPS THE LAST BAND OF LIGHT RAIN UNDER 35 DEGREES MOVING
SLOWLY EAST THROUGH AT LEAST 09Z. THEN...AREAS OF RAIN ARE
EXPECTED TO EXIT THE EASTERN MOUNTAINS. HOWEVER...PERIODS OF
IFR/LIFR WILL BE COMMON UNDER AREAS OF RAIN. A LOW LEVEL DECK
AROUND 500 FEET IS EXPECTED TO FORM OR CONTINUE ACROSS MOST SITES
THROUGH THE PREDAWN HOURS.
AREAS OF LIFR CIGS DEVELOPING MAINLY 03Z THROUGH 14Z OVERNIGHT...LIFTING
TO IFR/MVFR FOR REMAINDER OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF IFR/LIFR CIGS MAY VARY FROM CURRENT FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 12/09/13
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H M M M M M H H H H H
HTS CONSISTENCY M M H H H H H M H H H H
BKW CONSISTENCY H H M M M M M M M M M M
EKN CONSISTENCY M M M M M M M M M L L L
PKB CONSISTENCY M H M H H H L L L H H H
CKB CONSISTENCY H H H H H H M M M M M H
AFTER 06Z TUESDAY...
IFR POSSIBLE IN SNOW MONDAY NIGHT INTO TUESDAY.
&&
.EQUIPMENT...
ADDITIONAL PARTS FOR PARKERSBURG ASOS ARE EXPECTED TO ARRIVE MONDAY.
AUTOMATED OBSERVATIONS WILL BE UNAVAILABLE AT TIMES UNTIL THEN.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR WVZ035-
036-046-047.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR WVZ037-
038.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ/50
NEAR TERM...ARJ
SHORT TERM...50
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
419 AM EST MON DEC 9 2013
.SYNOPSIS...
A LOW PRESSURE WAVE CROSSES TODAY. A WEAK SYSTEM CROSSES LATE
TONIGHT INTO TUESDAY. CHILLY DRY HIGH PRESSURE FOR WEDNESDAY INTO
FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MAINLY ZONAL FLOW WILL PREVAIL TODAY...WITH AREAS OF CLEARING
SPREADING FROM WEST TO EAST. MODELS SHOW AN MID TO UPPER AIR VORT
MAX ASSOCIATED WITH AN H5 SHORTWAVE CROSSING THE AREA BY 18
TUESDAY.
LATEST RADAR IMAGES SHOW A BAND OF RAIN SHOWING SIGNS OF BREAKING
UP WITH RAIN DIMINISHING IN INTENSITY. WITH SATURATED
TERRAIN...KEPT FLOOD WATCH FOR THE WESTERN SLOPES OF WV...SOUTHWEST
VA AND SOUTHERN COAL FIELDS AS SOME DECENT PRECIPITATION AMOUNTS...0.5
TO 0.75 INCHES IN 6 HOURS HAVE BEEN REPORTED.
WINTER WEATHER ADVISORIES REMAIN IN EFFECT FROM RALEIGH...NORTH TO
WEBSTER FOR FREEZING RAIN AND SNOW...WHILE WINTER STORM WARNING
REMAINS IN EFFECT FOR POCAHONTAS AND RANDOLPH COUNTIES THROUGH 12Z
MONDAY.
WARM ADVECTION SHOULD CONTINUE THROUGH THE NIGHT...SO HAVE NON-
DIURNAL TEMPERATURES...BASED HEAVILY ON THE RAP AND WRF GUIDANCE.
WENT WITH THE WRF AND THE GFS GUIDANCE FOR TEMPERATURE THROUGH THE
PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
UPPER LEVEL SW FLOW FINALLY FLATTENS...BECOMING MORE ZONAL...IN THE
WAKE OF A S/W TROUGH THAT CROSSES TUE. SYSTEM IN THE NEAR TERM IS
ABOUT EXODUS BY 00Z TUE...THE START OF THE SHORT TERM...WITH PERHAPS
LIGHT UPSLOPE PRECIPITATION WINDING DOWN. WHILE NOT AS MOISTURE
RICH AS PREVIOUS SYSTEMS...JET DYNAMICS AND S/W FORCING IN THE
BAROCLINIC ZONE SHOULD GENERATE A QUICK HITTING BAND OF
PRECIPITATION THROUGH THE MIDDLE OHIO VALLEY EARLY TUE MORNING.
ANOTHER BAND BRUSHES THE CENTRAL APPALACHIANS AS A SFC WAVE MOVES NE
ALONG THE FRONT WHICH WILL BE OVER THE CAROLINAS AT THAT TIME.
COLDER AIR MOVING IN MON NT WILL DRIVE H85 TEMPERATURES TO -6C TO
-10C N BY TUE AFTERNOON...SO THE PRECIPITATION WILL TAKE THE FORM OF
SNOW...SAVE FOR MIXED PRECIPITATION EARLY ON OVER THE CENTRAL
APPALACHIANS.
ANY UPSLOPE PRECIPITATION IN THE WAKE OF THIS EVENT TUE AFTERNOON IS
BRIEF...AND HIGH PRESSURE BUILDS IN FOR A DRY AND COLD TUE NT...AND
THEN HANGS ON FOR A DRY WED.
USED ADJMET AND NAM FOR TEMPERATURES IN COLD ADVECTION MON
NT...BLENDED IN ADJMET FOR HIGHS TUE AND BIAS CORRECTED ADJMET FOR
LOWS TUE NT. BLENDED IN BIAS CORRECTED ADJMEX FOR HIGHS WED.
OVERALL NO MAJOR CHANGES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
STILL JUST WHAT THE DOCTOR ORDERED. A MOSTLY DRY PATTERN
WEDNESDAY NIGHT INTO SATURDAY. HAVE A SLIGHT CHANCE OF SOME
LIGHT SNOW SHOWERS WEDNESDAY NIGHT ACROSS THE NORTHERN WV
MOUNTAINS.
DRY AIR AND THE LONG DECEMBER NIGHTS YIELDS COLD DAWN TEMPERATURES.
DOWN THE ROAD...MOISTURE INCREASES SATURDAY...HAVE SOME CHANCE POPS
BY SATURDAY FOR RAIN AND SNOW. STILL APPEARS NOT A HEAVY EVENT.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
PERHAPS THE LAST BAND OF LIGHT RAIN UNDER 35 DEGREES MOVING
SLOWLY EAST THROUGH AT LEAST 09Z. THEN...AREAS OF RAIN ARE
EXPECTED TO EXIT THE EASTERN MOUNTAINS. HOWEVER...PERIODS OF
IFR/LIFR WILL BE COMMON UNDER AREAS OF RAIN. A LOW LEVEL DECK
AROUND 500 FEET IS EXPECTED TO FORM OR CONTINUE ACROSS MOST SITES
THROUGH THE PREDAWN HOURS.
AREAS OF LIFR CIGS DEVELOPING MAINLY 03Z THROUGH 14Z OVERNIGHT...LIFTING
TO IFR/MVFR FOR REMAINDER OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF IFR/LIFR CIGS MAY VARY FROM CURRENT FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 12/09/13
UTC 1HRLY 08 09 10 11 12 13 14 15 16 17 18 19
EST 1HRLY 03 04 05 06 07 08 09 10 11 12 13 14
CRW CONSISTENCY H H M M M M M H H H H H
HTS CONSISTENCY M M H H H H H M H H H H
BKW CONSISTENCY H H M M M M M M M M M M
EKN CONSISTENCY M M M M M M M M M L L L
PKB CONSISTENCY M H M H H H L L L H H H
CKB CONSISTENCY H H H H H H M M M M M H
AFTER 06Z TUESDAY...
IFR POSSIBLE IN SNOW MONDAY NIGHT INTO TUESDAY.
&&
.HYDROLOGY...
THE LAST OF THE RIVER FLOOD WARNINGS AT BELINGTON ASSOCIATED WITH
THE RAINFALL LAST THURSDAY AND FRIDAY...IS GONE.
HAVE FLOOD WATCH FOR MUCH OF THE WV LOWLANDS AND INTO NE KY AS MORE
RAINFALL IS EXPECTED TONIGHT INTO MONDAY...WHICH MAY CAUSE
ADDITIONAL RISES ON RIVERS. THIS ADDITIONAL RAIN MAY ALSO CAUSE
FLOODING ALONG SMALL CREEKS AND STREAMS. WILL NEED TO MONITOR TRENDS
TONIGHT FOR WHERE THE BAND OF HEAVIEST PRECIPITATION SETS UP...AND
THUS WHERE THE AREA OF HIGHEST CONCERN IS.
&&
.EQUIPMENT...
ADDITIONAL PARTS FOR PARKERSBURG ASOS ARE EXPECTED TO ARRIVE MONDAY.
AUTOMATED OBSERVATIONS WILL BE UNAVAILABLE AT TIMES UNTIL THEN.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR WVZ035-
036-046-047.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR WVZ037-
038.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...KTB/ARJ/TRM/MZ
NEAR TERM...ARJ
SHORT TERM...TRM
LONG TERM...KTB
AVIATION...ARJ
HYDROLOGY...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
107 AM EST MON DEC 9 2013
.SYNOPSIS...
WARM FRONT LIFTS NORTH INTO TONIGHT. A LOW PRESSURE WAVE CROSSES
LATER TONIGHT INTO MONDAY. A WEAK SYSTEM CROSSES LATE MONDAY NIGHT
INTO TUESDAY. CHILLY DRY HIGH PRESSURE FOR WEDNESDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
POPS AND WEATHER GRIDS REMAIN ON TRACK AS THE LAST BAND OF RAIN
GRADUALLY MOVE EAST TOWARDS THE MOUNTAINS. TWEAKED SFC WINDS
FOLLOWING THE LATEST SFC OBS AND THE RUC PROJECTION UP TO 12
HOURS.
A BAND OF RAIN...SHOW SIGNS OF BREAKING UP WITH RAIN DIMINISHING
IN INTENSITY. WITH SATURATED TERRAIN...KEPT FLOOD WATCH FOR THE
WESTERN SLOPES OF WV...SOUTHWEST VA AND SOUTHERN COAL FIELDS AS
SOME DECENT PRECIPITATION AMOUNTS...0.5 TO 0.75 INCHES IN 6 HOURS
HAVE BEEN REPORTED.
WINTER WEATHER ADVISORIES REMAIN IN EFFECT FROM RALEIGH...NORTH TO
WEBSTER FOR FREEZING RAIN AND SNOW...WHILE WINTER STORM WARNING
REMAINS IN EFFECT FOR POCAHONTAS AND RANDOLPH COUNTIES THROUGH 12Z
MONDAY.
WARM ADVECTION SHOULD CONTINUE THROUGH THE NIGHT...SO HAVE NON-
DIURNAL TEMPERATURES...BASED HEAVILY ON THE RAP AND WRF GUIDANCE.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY/...
UPPER LEVEL SW FLOW FINALLY FLATTENS...BECOMING MORE ZONAL...IN THE
WAKE OF A S/W TROUGH THAT CROSSES TUE. SYSTEM IN THE NEAR TERM IS
ABOUT EXODUS BY 00Z TUE...THE START OF THE SHORT TERM...WITH PERHAPS
LIGHT UPSLOPE PRECIPITATION WINDING DOWN. WHILE NOT AS MOISTURE
RICH AS PREVIOUS SYSTEMS...JET DYNAMICS AND S/W FORCING IN THE
BAROCLINIC ZONE SHOULD GENERATE A QUICK HITTING BAND OF
PRECIPITATION THROUGH THE MIDDLE OHIO VALLEY EARLY TUE MORNING.
ANOTHER BAND BRUSHES THE CENTRAL APPALACHIANS AS A SFC WAVE MOVES NE
ALONG THE FRONT WHICH WILL BE OVER THE CAROLINAS AT THAT TIME.
COLDER AIR MOVING IN MON NT WILL DRIVE H85 TEMPERATURES TO -6C TO
-10C N BY TUE AFTERNOON...SO THE PRECIPITATION WILL TAKE THE FORM OF
SNOW...SAVE FOR MIXED PRECIPITATION EARLY ON OVER THE CENTRAL
APPALACHIANS.
ANY UPSLOPE PRECIPITATION IN THE WAKE OF THIS EVENT TUE AFTERNOON IS
BRIEF...AND HIGH PRESSURE BUILDS IN FOR A DRY AND COLD TUE NT...AND
THEN HANGS ON FOR A DRY WED.
USED ADJMET AND NAM FOR TEMPERATURES IN COLD ADVECTION MON
NT...BLENDED IN ADJMET FOR HIGHS TUE AND BIAS CORRECTED ADJMET FOR
LOWS TUE NT. BLENDED IN BIAS CORRECTED ADJMEX FOR HIGHS WED.
OVERALL NO MAJOR CHANGES.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
STILL JUST WHAT THE DOCTOR ORDERED. A MOSTLY DRY PATTERN
WEDNESDAY NIGHT INTO SATURDAY. HAVE A SLIGHT CHANCE OF SOME
LIGHT SNOW SHOWERS WEDNESDAY NIGHT ACROSS THE NORTHERN WV
MOUNTAINS.
DRY AIR AND THE LONG DECEMBER NIGHTS YIELDS COLD DAWN TEMPERATURES.
DOWN THE ROAD...MOISTURE INCREASES SATURDAY...HAVE SOME CHANCE POPS
BY SATURDAY FOR RAIN AND SNOW. STILL APPEARS NOT A HEAVY EVENT.
&&
.AVIATION /06Z MONDAY THROUGH FRIDAY/...
PERHAPS THE LAST BAND OF LIGHT RAIN UNDER 35 DEGREES MOVING
SLOWLY EAST THROUGH AT LEAST 09Z. THEN...AREAS OF RAIN ARE
EXPECTED TO EXIT THE EASTERN MOUNTAINS. HOWEVER...PERIODS OF
IFR/LIFR WILL BE COMMON UNDER AREAS OF RAIN. A LOW LEVEL DECK
AROUND 500 FEET IS EXPECTED TO FORM OR CONTINUE ACROSS MOST SITES
THROUGH THE PREDAWN HOURS.
AREAS OF LIFR CIGS DEVELOPING MAINLY 03Z THROUGH 14Z OVERNIGHT...LIFTING
TO IFR/MVFR FOR REMAINDER OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 06Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF IFR/LIFR CIGS MAY VARY FROM CURRENT FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
DATE MON 12/09/13
UTC 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
EST 1HRLY 01 02 03 04 05 06 07 08 09 10 11 12
CRW CONSISTENCY M M H H M M M M M H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M H H M M M H H M H M
EKN CONSISTENCY M M M M M M M M M M M L
PKB CONSISTENCY H H M H H H H H L L L H
CKB CONSISTENCY M H H M M M M M H M M M
AFTER 06Z TUESDAY...
IFR POSSIBLE IN SNOW MONDAY NIGHT INTO TUESDAY.
&&
.HYDROLOGY...
THE LAST OF THE RIVER FLOOD WARNINGS AT BELINGTON ASSOCIATED WITH
THE RAINFALL LAST THURSDAY AND FRIDAY...IS GONE.
HAVE FLOOD WATCH FOR MUCH OF THE WV LOWLANDS AND INTO NE KY AS MORE
RAINFALL IS EXPECTED TONIGHT INTO MONDAY...WHICH MAY CAUSE
ADDITIONAL RISES ON RIVERS. THIS ADDITIONAL RAIN MAY ALSO CAUSE
FLOODING ALONG SMALL CREEKS AND STREAMS. WILL NEED TO MONITOR TRENDS
TONIGHT FOR WHERE THE BAND OF HEAVIEST PRECIPITATION SETS UP...AND
THUS WHERE THE AREA OF HIGHEST CONCERN IS.
&&
.EQUIPMENT...
ADDITIONAL PARTS FOR PARKERSBURG ASOS ARE EXPECTED TO ARRIVE MONDAY.
AUTOMATED OBSERVATIONS WILL BE UNAVAILABLE AT TIMES UNTIL THEN.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...FLOOD WATCH THROUGH THIS AFTERNOON FOR WVZ005-006-013>016-018-
020-024>040.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR WVZ037-
038.
WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR WVZ035-
036-046-047.
OH...NONE.
KY...FLOOD WATCH THROUGH THIS AFTERNOON FOR KYZ105.
VA...FLOOD WATCH THROUGH THIS AFTERNOON FOR VAZ003-004.
&&
$$
SYNOPSIS...KTB/TRM/MZ
NEAR TERM...ARJ/MZ/SL
SHORT TERM...TRM
LONG TERM...KTB
AVIATION...ARJ
HYDROLOGY...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1125 PM CST SUN DEC 8 2013
.UPDATE...AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 844 PM CST SUN DEC 8 2013/
DISCUSSION...02 SURFACE ANALYSIS PLACES A WEAK QUASI-STATIONARY
BOUNDARY/SURFACE LOW NEAR THE LOUISIANA/MISSISSIPPI/ALABAMA GULF
COAST THIS EVENING. MEANWHILE...A RIDGE OF HIGH PRESSURE IS
LOCATED ACROSS PORTIONS OF THE MIDDLE MISSISSIPPI VALLEY INTO
PORTIONS OF THE MID SOUTH. TEMPERATURES AS OF 8 PM CST RANGE FROM
THE MIDDLE 30S TO AROUND 40 DEGREES ACROSS WEST TENNESSEE NEAR THE
TENNESSEE RIVER AND PORTIONS OF NORTHEAST MISSISSIPPI AND UPPER
20S TO LOWER 30S ALONG AND WEST OF THE MISSISSIPPI RIVER.
KNQA/KGWX WSR-88D RADAR TRENDS INDICATE LIGHT RAIN SHOWERS ACROSS
NORTHEAST MISSISSIPPI IN ASSOCIATION WITH A MID LEVEL SHORTWAVE
TROUGH AND AN UPPER LEVEL JET STREAK MOVING ACROSS THE REGION.
LATEST RUC SHORT TERM MODEL SEEMS TO BE HANDLING CURRENT TRENDS
THE BEST WITH RESPECT TO PRECIPITATION. WILL MAKE ADJUSTMENTS TO
LIMIT AND LOWER PRECIPITATION CHANCES OVERNIGHT TO EXTREME
NORTHEAST MISSISSIPPI.
AS OF 8 PM CST...VISIBILITIES ARE CURRENTLY RANGING FROM 4SM TO
P6SM. LIGHT WINDS HAVE KEPT LOW LEVEL MOISTURE LIFTED AS A LOW
STRATUS LAYER THUS FAR. WILL CONTINUE TO MONITOR SHORT TERM TRENDS
FOR THE POSSIBLE DEVELOPMENT OF FOG/FREEZING FOG AND ANY HEADLINES
IF IT BECOMES NECESSARY.
WILL ALSO MAKE MINOR ADJUSTMENTS TO TEMPERATURES AND ALL OTHER
ELEMENTS AS NEEDED TO ACCOUNT FOR LATEST TRENDS.
UPDATED GRIDS WILL BE AVAILABLE SHORTLY.
CJC
PREV DISCUSSION... /ISSUED 536 PM CST SUN DEC 8 2013/
UPDATE...AVIATION DISCUSSION.
PREV DISCUSSION... /ISSUED 320 PM CST SUN DEC 8 2013/
A SHARP TEMPERATURE GRADIENT IS OCCURRING ACROSS THE MIDSOUTH
THIS EVENING. LOCATIONS SOUTH AND EAST OF A MEMPHIS TO JACKSON
TENNESSEE LINE ARE REPORTING TEMPERATURES IN THE MID 30S TO LOWER
40S. NORTH AND WEST OF THIS LINE TEMPERATURES RANGE FROM 28-32
DEGREES. TEMPERATURES ALSO REMAIN NEAR FREEZING FARTHER SOUTH IN
THE DELTA SUCH AS MARIANNA...TUNICA AND CLARKSDALE. PATCHY DENSE
FREEZING FOG HAS FORMED ALONG THIS GRADIENT BETWEEN THE ARCTIC AIR
AND THE WARMER AIR. WEST
MEMPHIS...MILLINGTON...BLYTHEVILLE...DYERSBURG AND UNION CITY ARE
REPORTING VISIBILITIES FROM A QUARTER MILE TO THREE QUARTERS OF A
MILE. THUS FAR NO ICING HAS OCCURRED AS A RESULT OF THE FOG BUT A
LITTLE WORRIED THAT THIS MAY CHANGE ONCE THE SUN GOES DOWN. WILL
LET EVENING SHIFT MONITOR FOR ANY POTENTIAL ADVISORIES.
MEANWHILE...RAIN CONTINUES TO PUSH NORTHWARD INTO NORTH
MISSISSIPPI WHERE LOCATIONS ARE ABOVE FREEZING. THIS IS DUE TO A
SFC LOW DEVELOPING ALONG A STATIONARY FRONT NEAR THE GULF COAST.
MODELS INDICATE THE NORTHERN EXTENT OF THE PRECIPITATION COULD
REACH INTO LOCATIONS THIS EVENING THAT ARE SITTING JUST ABOVE OR
AT FREEZING CURRENTLY. AS TEMPERATURES DROP THIS EVENING THIS
COULD CHANGE RAIN OVER TO FREEZING RAIN...BUT CONFIDENCE IS LOW
THUS AGAIN WILL LET EVENING SHIFT MONITOR FOR ANY POTENTIAL
ADVISORIES. WILL JUST MENTION A SLIGHT CHANCE OR CHANCE OF
FREEZING RAIN IN THE FORECAST AS BEST CHANCES OF PRECIPITATION
WILL OCCUR ACROSS NORTHEAST MISSISSIPPI WHERE LOCATIONS WILL
REMAIN ABOVE FREEZING.
ANOTHER SFC LOW WILL DEVELOP ALONG THE STATIONARY FRONT LOCATED
ALONG THE GULF COAST BY MONDAY EVENING. THIS WILL BRING ANOTHER
ROUND OF PRECIPITATION THAT WILL SKIRT NORTHEAST MISSISSIPPI.
HOWEVER BY MONDAY EVENING...NORTHWEST WINDS WILL HAVE PUSHED
ARCTIC AIR FURTHER SOUTH AND EAST THUS PRECIPITATION COULD FALL IN
THE FORM OF FREEZING RAIN IF PRECIPITATION MAKES IT AS FAR NORTH
AS NORTHEAST MISSISSIPPI. STAY TUNED.
IN ADDITION...A SHORTWAVE WILL SWING ACROSS SOUTHERN MISSOURI AND
WESTERN KENTUCKY MONDAY NIGHT. THIS COULD BRING A BRIEF SHOT OF LIGHT
SNOW ACROSS PORTIONS OF NORTHEAST ARKANSAS...THE MISSOURI BOOTHEEL
AND NORTHWEST TENNESSEE. ANY ACCUMULATIONS THAT WOULD OCCUR WOULD
BE LESS THAN AN INCH.
BY TUESDAY...ARCTIC HIGH PRESSURE SETTLES OVER THE MIDSOUTH.
EXPECT DRY CONDITIONS WITH HIGHS RANGING FROM THE LOWER 30S TO
LOWER 40S. A REINFORCING SHOT OF ARCTIC AIR WILL MOVE INTO THE
AREA ON WEDNESDAY INTO WEDNESDAY NIGHT. LOWS WEDNESDAY NIGHT WILL
RANGE FROM THE MID TEENS TO THE MID 20S.
BY THURSDAY NIGHT...THE HIGH WILL SHIFT EAST TURNING WINDS AROUND TO
THE SOUTH. THE NEXT LOW PRESSURE SYSTEM WILL MOVE INTO THE AREA ON
FRIDAY AND WILL BRING CHANCES FOR PRECIPITATION TO THE MIDSOUTH
OVER THE NEXT WEEKEND. HOW QUICKLY THE ARCTIC AIR DEPARTS WILL
DEPEND ON POSSIBLY PRECIPITATION TYPE FOR PORTIONS OF NEXT
WEEKEND. THE 12Z ECMWF IS COLDER THAN THE 12Z GFS. FOR NOW HAVE
TRIED TO GO WITH AN IN BETWEEN SOLUTION WHICH WOULD HAVE
TEMPERATURES NEAR NORMAL AND WOULD KEEP PRECIPITATION IN THE FORM
OF RAIN.
KRM
.AVIATION...06Z TAF CYCLE
VIS HAS IMPROVED TO MVFR LEVELS OR HIGHER AT ALL SITES BUT CIGS
REMAIN IFR EVERYWHERE EXCEPT JBR. NOT AS CONFIDENT THAT WE WILL
SEE THE LIFR CIGS WE HAD IN PREVIOUS ISSUANCES. FEEL LIKE WE WILL
SEE OVERALL SLOWLY IMPROVING CIGS WITH NEAR STEADY VIS FOR THE
REMAINDER OF THE NIGHT. GUIDANCE WANTS TO CONTINUE TO LIFT CIGS
THROUGH THE DAY EVEN TO VFR LEVELS...BASED ON EXPERIENCE...FEEL
LIKE CLOUDS WILL LINGER LONGER THAN GUIDANCE SUGGESTS...BUT WILL
BRING LEVELS TO 5KFT DURING THE AFTERNOON FOR ALL LOCATIONS EXCEPT
TUP.
RAIN AT TUP WILL BE LIGHT...WITH LITTLE TO NO PRECIPITATION
ELSEWHERE. SOME PATCHY DRIZZLE MAY DEVELOP...AND MEM IS CURRENTLY
REPORTING -DZ BUT DO NOT FEEL LIKE THIS WILL BE A PREVAILING
CONDITION. WINDS GENERALLY LIGHT OVERNIGHT...LIGHT FROM THE NORTH
TOMORROW. SOME LIGHT RAIN MAY MOVE BACK NEAR TUP LATE TOMORROW.
JDS
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 31 39 27 38 / 40 10 20 10
MKL 31 38 24 37 / 50 10 20 10
JBR 25 31 24 32 / 10 10 20 10
TUP 37 43 33 42 / 80 30 60 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
356 AM CST MON DEC 9 2013
.SHORT TERM...
Today and Tonight
A cold front is currently moving through the Big Country and
should be approaching the Interstate 10 corridor shortly after
sunrise. Winds behind the front will become north and increase to
about 8 to 12 mph, with colder air slowly filtering into West
Central Texas. In addition, areas of freezing fog are evident just
to the east of our area, which has slowly been creeping west. I
expect this freezing fog to expand to a Throckmorton, to Coleman,
to Mason line in the next few hours. A freezing fog advisory is in
effect for parts of the Heartland through 9 AM, and I will
continue to monitor trends for the possibility of expanding it
north into parts of the Big Country and south toward Mason county.
The HRRR is also indicating some post frontal fog across parts of
the Big Country, which will need to be monitored. Stratus should
fill in this morning behind the front, with much of the area
becoming overcast by mid morning. Given the expected cloud cover
and cold air advection, I lowered high temperatures slightly.
Highs will range from the upper 20s north of Interstate 20, to the
mid 40s across the Interstate 10 corridor.
Cloudy skies through much of the overnight period will not
support ideal radiational cooling conditions, but given the cold
airmass that will be filtering into the region, I went ahead and
lowered low temperatures slightly. Tuesday morning low
temperatures will generally be in the teens to lower 20s across
all of West Central Texas.
Daniels
.LONG TERM...
Tuesday through Sunday
As a fast moving shortwave trough moves through the Great Lakes
region Tuesday night into Wednesday, a cold front will move into
Texas, causing another brief cooling for Wednesday into Thursday.
However, no precipitation is expected with the front. Lee
troughing on Thursday will allow winds to quickly turn back to the
south in our area, allowing temperatures to warm back up across
the area Thursday and especially Friday. An upper level low
initially off the coast of California on Monday will move across
the Desert Southwest and into the Texas panhandle by Friday. As
this low approaches, weak shortwaves will move across the area out
ahead of it, interacting with moisture return and low level warm
air advection, resulting in at least a slight chance for showers
mainly Thursday afternoon and Thursday night, with some lingering
showers moving out of the area on Friday.
The upper level low will then move east towards the Mississippi
Valley by Saturday, sending a cold front into the area. And while
the cold front will slow the warming trend, the air mass behind
the front will not be of arctic origin, so while we have gone
cooler than the MOS guidance for Saturday and Sunday, temperatures
should continue to trend closer to normal values through the
weekend.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 26 18 39 27 42 / 10 5 0 0 0
San Angelo 35 19 44 26 46 / 10 5 0 0 0
Junction 46 22 47 24 52 / 10 10 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY until 9 AM CST this morning FOR THE
FOLLOWING ZONES: Brown...Callahan...Coleman...McCulloch...San
Saba.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1100 PM CST SUN DEC 8 2013
.UPDATE...
Areas of dense fog over Central TX continue to build back to the
west this evening and are right on the CWA border near San Saba and
Brownwood. Given extremely low dewpoint depressions, a general east
to southeast flow, and some residual sleet/ice pack on the ground, I
expect this westward trend to continue. BUFKIT hydrolapse analysis
of the NAM and RAP data indicate support this conceptual model.
Thus, I have issued a Freezing Fog Advisory for areas along and east
of a Baird, to Coleman, to Brady through 9 AM Monday. Visibilities
are already down to 1/4 mile at Lampasas and Hamilton and RH values
at Brownwood and Brady are greater than 93% currently. Given
sub-freezing temperatures, any areas of dense fog will likely result
in light ice accumulations on exposed surfaces. For aviation
impacts, see the aviation section below.
The remainder of the forecast package was in good shape. Minor
changes were made to overnight temperatures, with lows across the
Big Country increased by just a few degrees.
Johnson
&&
.AVIATION...
The forecast terminals will begin to the period with benign
conditions but I expected patchy freezing fog to develop overnight
across West Central TX. At this time, the greatest threat appears
to exist from KBWD to KBBD, but freezing fog will be possible at all
terminals later tonight. Visibilities are the lowest at KBBD with
only minor reductions forecast for the remaining forecast terminals.
In addition to the fog, an arctic cold front will move south across
West Central TX overnight, resulting in north to northeast winds of
8-12 kts and low ceilings. IFR ceilings are expected to develop late
tonight and persist through midday, gradually improving into MVFR
range during the afternoon and evening hours. Patchy, post-frontal
freezing drizzle is a concern but low confidence does not warrant a
mention in the current forecast package.
Johnson
&&
.PREV DISCUSSION... /ISSUED 540 PM CST SUN DEC 8 2013/
AVIATION...
Another shallow arctic cold front will move through West Central TX
late tonight and early Monday. Ahead of the cold front, we`ll see
light winds, generally from the south, under clear skies.
Sublimation over the sleet/ice pack will promote the development of
patchy fog (and freezing fog) tonight. Enough spatial uncertainty
exists that it extremely low visibilities will not be included in
the current TAF package. I did, however, reduce visibilities to 3-5
statute miles in most areas, but amendments may be required in areas
where fog does form as the forecast is likely too optimistic. Some
of this fog may lift into an IFR stratus deck as well.
As the front moves through the area, winds will shift to the north
at 8-10 kts and stratus is expected to become more widespread. I
would not rule out some patchy, post-frontal freezing drizzle.
Again, however, the relatively low probability does not warrant
mention in the TAF. I expect slow improvement in ceiling heights on
Monday afternoon as the cold air deepens and lift over the frontal
zone weakens.
Johnson
PREV DISCUSSION... /ISSUED 355 PM CST SUN DEC 8 2013/
SHORT TERM...
Tonight and Monday
Patchy freezing fog tonight and Arctic air Monday
Clearing skies and light winds may allow the development of patchy
freezing fog. This may potentially bring icing to bridges and
overpasses, mainly after midnight, as temperatures fall to the dew
point. Sleet from last week has been finally melting, with the
visible satellite imagery still indicating sleet on the ground from
the Big Country southward to San Angelo, Brady, and Brownwood. The
sleet will help moisten the boundary level tonight, further enhancing
the potential for fog.
An arctic cold front will move into the Big country, moving through
the I-20 corridor around 3 AM, and I-10 corridor around 9 AM. Low
level cloud development and mixing should dissipate the fog as the
arctic front moves through. Temperatures in the Big Country will
likely stay in the 20s Monday with wind chills in the single digits
in the morning. People should dress accordingly.
LONG TERM...
Monday Night through Sunday
Cold temperatures will continue Monday night and Tuesday with a
warming trend Wednesday through next weekend. A short wave trough
will move across the Southern Plains Monday night with surface high
pressure settling into the area into Tuesday. Temperatures will be
very cold Monday night with overnight lows falling into the upper
teens and lower 20s. The cold surface high will be overhead on
Tuesday and despite some sunshine, temperatures will remain well
below normal with afternoon highs ranging from the upper 30s along
and north of the I-20 corridor, to the lower 40s along the I-10
corridor.
By Wednesday, a broad upper level trough will cover much of the
country with a weak upper low developing over the Baja region.
A weak cold front will move across the area again on Wednesday
but the associated surface high and coldest airmass will remain
well northeast of the area through Thursday. Temperatures both
Wednesday and Thursday will continue to be well below normal but
will at least warm into the mid and upper 40s during the afternoon
hours, with a few low 50s possible along the I-10 corridor.
Southerly flow and increasing moisture return Thursday night and
Friday ahead of the approaching upper low over the Desert Southwest.
This system will bring a low chance of rainfall to mainly eastern
sections Thursday night and early Friday. Models show another upper
level trough and possible front affecting the area over the weekend
but this system looks dry. Expect warmer temperature Friday through
Sunday with highs in the 50s and lows in the 30s.
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 20 28 17 38 24 / 0 5 5 0 5
San Angelo 25 37 20 43 24 / 0 5 5 5 5
Junction 28 45 23 45 24 / 5 10 10 5 5
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY until 9 AM CST Monday FOR THE FOLLOWING
ZONES: Brown...Callahan...Coleman...McCulloch...San Saba.
&&
$$
25
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
352 AM CST MON DEC 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 9 2013
MAIN SHORT TERM CONCERNS ARE ON TEMPERATURES...WIND CHILLS AND
POTENTIAL FOR MORE SNOW LATER TONIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A HIGHLY AMPLIFIED RIDGE OVER THE EASTERN PACIFIC...A DEEP
TROUGH FROM CENTRAL CANADA INTO THE FOUR CORNERS...AND RIDGING OVER
THE SOUTHEASTERN U.S.. WITHIN THE DEEP TROUGH THERE WERE 3
SHORTWAVES OF NOTE. THE FIRST WAS OVER SOUTHEAST WISCONSIN WHICH
HELPED BRING THE SNOW TO THE AREA YESTERDAY INTO THE EARLY MORNING
HOURS. MOST OF THE SNOW HAS PUSHED OFF TO THE EAST AS SHOWN BY RADAR
IMAGERY...IN RESPONSE TO SUBSIDENCE AND ISENTROPIC DESCENT IN THE
WAKE OF THE SHORTWAVE. THE SECOND SHORTWAVE OF NOTE WAS OVER THE
DAKOTAS. ALTHOUGH THIS SHORTWAVE WAS ONLY PRODUCING SOME ALTOSTRATUS
AHEAD OF IT...DUE TO DRY AIR SEEN ON THE 00Z BIS SOUNDING...THERE
WAS PLENTY OF COLD AIR WITH IT. 850MB TEMPS ACCORDING TO THE RAP ARE
-25C ACROSS NORTH DAKOTA...OR 2 STANDARD DEVIATIONS BELOW NORMAL.
FINALLY...THE THIRD SHORTWAVE WAS COMING DOWN THE BACK SIDE OF THE
TROUGH THROUGH CENTRAL ALBERTA. IMPRESSIVE 140KT JET AT THE
TROPOPAUSE ACCOMPANYING THE SHORTWAVE. ALREADY SOME LIGHT SNOW
FALLING JUST AHEAD OF THE SHORTWAVE.
A LOT OF RAPID MOTION FORECAST OVER THE NEXT 24 HOURS IN THE UPPER
LEVEL PATTERN...MOSTLY A RESULT FROM THAT STRONG UPPER JET CORE
COMING THROUGH ALBERTA. FIRST OFF...THE SHORTWAVE TROUGH OVER NORTH
DAKOTA IS PROGGED BY MODELS TO SLIDE THROUGH THE FORECAST AREA THIS
AFTERNOON. WE MAY SEE SOME MID OR HIGH CLOUDS PASS THROUGH AHEAD OF
THE SHORTWAVE...BUT THE BULK OF THE CLOUD COVER IS GOING TO BE THE
CURRENT STRATUS AFFECTING THE AREA. ANTICIPATING AS THE SHORTWAVE
PASSES...THE DRY ARCTIC AIR SEEN ACROSS NORTH DAKOTA CURRENTLY WILL
CLEAR OUT THE STRATUS. THIS MAY HAPPEN PRETTY QUICK WITH CLEARING
ALREADY COMING INTO THE FORECAST AREA. IN ADDITION...THAT SAME
ARCTIC AIR IS EXPECTED TO CAUSE TEMPERATURES TO FALL AS 850MB TEMPS
PLUMMET FROM THE CURRENT -14 TO -18C READINGS TO -18 TO -22C BY 21Z.
WINDS LOOK TO CRANK UP TOO AS THAT SHORTWAVE AND ASSOCIATED COLD AIR
COME IN. THESE WINDS...WITH GUSTS UPWARDS OF 20 TO 30 MPH...ARE
LIKELY TO CAUSE SOME BLOWING AND DRIFTING OF THE RECENT SNOW. AS
TEMPERATURES FALL THIS AFTERNOON...WIND CHILLS WILL BECOME MORE OF
AN ISSUE. TAYLOR/CLARK COUNTIES LOOK TO DROP INTO ADVISORY RANGE
AROUND 22Z AND DO NOT GET OUT UNTIL 12Z TUESDAY...THUS HAVE GONE
AHEAD AND ISSUED AN ADVISORY FOR THEM.
THE COLD AIR TONIGHT DOES NOT LAST LONG. MODELS ARE IN GOOD
AGREEMENT SHOWING THE ALBERTA SHORTWAVE DIGGING INTO THE DAKOTAS
THIS EVENING...THEN MOVING INTO THE FORECAST AREA TOWARDS 12Z. AS
THIS SHORTWAVE APPROACHES...WARM ADVECTION ENSUES...WITH 850MB TEMPS
CLIMBING UP TO -13 TO -17C BY 09Z. ALL INDICATIONS ARE THAT THE
ISENTROPIC LIFT AND SOME MOISTURE ADVECTION WILL CAUSE A MID CLOUD
DECK TO SPREAD ACROSS THE FORECAST AREA. THESE CLOUDS AND THE WARM
ADVECTION SHOULD RESULT IN RISING TEMPS LATE THIS EVENING INTO THE
OVERNIGHT...HELPING TO BRING WIND CHILLS UP. ADDITIONALLY...THE BEST
JUXTAPOSITION OF LOW LEVEL SATURATION AND ISENTROPIC LIFT OCCURS
NORTH OF INTERSTATE 90. GIVEN THE ARCTIC AIRMASS IN PLACE PRIOR TO
THE SHORTWAVE ARRIVAL...LIKELY WILL NOT TAKE MUCH TO SNOW. QPF MAY
NOT AMOUNT TO MUCH WITH THE COLD AIRMASS...MAYBE A COUPLE HUNDREDTHS
TOPS...BUT ENOUGH FORCING TO WARRANT HIGH PRECIPITATION CHANCES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 9 2013
MAIN LONG TERM FORECAST CONCERNS ARE ON TEMPERATURES...AS WELL AS
THE OSCILLATING DIURNAL TRENDS WITH THEM...AND POTENTIAL FOR
PRECIPITATION THROUGHOUT.
SHORTWAVE TROUGH COMING INTO THE FORECAST AREA TONIGHT QUICKLY MOVES
THROUGH DURING THE TUESDAY MORNING HOURS. ANY SNOW LOOKS TO DEPART
OFF TO THE EAST PRETTY FAST IN THE MORNING...FOLLOWED BY CLEARING
AND BRISK WEST WINDS. THESE WINDS COULD RESULT IN MORE BLOWING
SNOW...ESPECIALLY IF WE CAN GET A FEW TENTHS OUT OF TONIGHT.
ADDITIONALLY...THE WINDS DRIVE IN A BRIEF SURGE OF ARCTIC AIR WITH
850MB TEMPS FALLING TO -16 TO -20C BY 18Z. 09.00Z
ECMWF/NAM/CANADIAN/GFS THEN ALL DEPICT YET ANOTHER SHORTWAVE TROUGH
DROPPING INTO THE DAKOTAS TUESDAY NIGHT. AHEAD OF THIS
FEATURE...INCREASING ISENTROPIC LIFT AND MID LEVEL FRONTOGENESIS
LOOKS TO DEVELOP A BAND OF SNOW. POSITION OF THIS BAND OF SNOW IS
PROBLEMATIC...WITH THE ECMWF/NAM FARTHER NORTH COMPARED TO THE
GFS/CANADIAN. CONSENSUS WOULD SUGGEST LOCATIONS SOUTH OF I-90 WOULD
STAND TO SEE THE BEST CHANCE OF SEEING SNOW...SO RAISED CHANCES
TOWARDS 60 IN THIS AREA. THE BAND DOES APPEAR TO BE QUICK MOVING...
SUCH THAT BY 12Z WEDNESDAY...ITS ALREADY SOUTHEAST OF THE AREA.
NONETHELESS...WITH SNOW TO WATER RATIOS APPROACH 20 TO 1...WE COULD
SQUEEZE OUT AN INCH OR SO OUT OF THIS BAND.
JUST LIKE IN THE WAKE OF THE EVERY SHORTWAVE TROUGH...ANOTHER SURGE
OF ARCTIC AIR IS PROGGED TO FLOW INTO THE AREA ON WEDNESDAY WHEN THE
TROUGH MOVES THROUGH. 850MB TEMPS DROP TO -20 TO -24C AT 18Z
WEDNESDAY. THUS...DESPITE THAT SKIES SHOULD CLEAR ON WEDNESDAY AS
THE TROUGH COMES IN...IT WILL BE TOUGH TO WARM UP MUCH. MOST
LOCATIONS ARE LIKELY TO NOT GET OUT OF THE SINGLE DIGITS ABOVE
ZERO...AND NORTH OF HIGHWAY 10 MAY NOT EVEN GET TO ZERO. WITH THE
COLD TEMPS AND A NORTHWEST BREEZE...WIND CHILLS ARE YET AGAIN A
FACTOR WITH ANOTHER ADVISORY LIKELY NEEDED. NORTH OF HIGHWAY 10
APPEARS TO BE THE MOST LIKELY AREA FOR AN ADVISORY...STARTING LATE
TUESDAY NIGHT AND RUNNING THROUGH WEDNESDAY NIGHT. WEDNESDAY NIGHT
IS INTERESTING TOO. ALL MODELS ARE SUGGESTING RISING 500MB HEIGHTS
ACROSS THE CENTRAL PART OF THE COUNTRY. WARM ADVECTION ASSOCIATED
WITH THESE RISING HEIGHTS SHOULD CAUSE TEMPERATURES TO RISE...AFTER
A RAPID DROP OFF IN THE EVENING ASSOCIATED WITH A SURFACE RIDGE
PASSAGE. THERE MAY EVEN BE SOME SNOW THAT TRIES TO GET GOING NORTH
OF I-94...AS SUGGESTED BY THE ECMWF/CANADIAN AND HAVE INCLUDED 20
PERCENT CHANCES FOR THIS. THESE CHANCES PERSIST INTO THURSDAY. MUCH
WARMER 850MB TEMPS ON THURSDAY...ON THE ORDER OF -2 TO -8C BY
00Z...WILL RESULT IN HIGHS 15-20 DEGREES WARMER COMPARED TO
WEDNESDAY.
FROM THURSDAY NIGHT THROUGH SUNDAY...09.00Z ECMWF/GFS/CANADIAN
SUGGEST A NORTHWEST FLOW PATTERN IN THE MEAN...STRETCHING FROM
BRITISH COLUMBIA INTO THE GREAT LAKES. AT THE MOMENT THURSDAY NIGHT
LOOKS DRY. AS WE HEAD INTO FRIDAY AND ESPECIALLY FRIDAY
NIGHT...THERE ARE SUGGESTIONS A SOUTHERN STREAM SHORTWAVE TROUGH
COMING OUT OF THE CENTRAL PLAINS AND HEADING INTO THE OHIO VALLEY
COULD SPREAD SOME LIGHT SNOW INTO THE FORECAST AREA. THE CANADIAN IS
THE FARTHEST NORTHWEST AND DID HONOR THE SOLUTION WITH A 20 PERCENT
CHANCE. HOWEVER...THE 09.00Z GFS/ECMWF SUGGEST IT COULD STAY TO THE
SOUTHEAST...THUS SOMETHING TO MONITOR. HEADING INTO THE WEEKEND...
THE ECMWF/GFS SUGGEST A POTENT UPPER TROUGH WILL BE DROPPING SOUTH
INTO MANITOBA AND ONTARIO. THE ECMWF IS VERY AGGRESSIVE DIGGING IT
INTO WISCONSIN ON SUNDAY. FOR NOW STAYED WITH THE CONSENSUS WHICH
YIELDS A GENERALLY DRY SOLUTION WITH TEMPERATURES HOVERING SLIGHTLY
BELOW NORMAL. HOWEVER...SHOULD THE 00Z ECMWF BE CORRECT...
TEMPERATURES MAY NEED SIGNIFICANT LOWERING FOR SUNDAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1100 PM CST SUN DEC 8 2013
SNOW WILL BE EXITING EAST OVER THE NEXT FEW HOURS AS THE RESPONSIBLE
UPPER LEVEL SHORTWAVE HEADS TOWARD THE EASTERN GREAT LAKES. WINDS
WILL PICK UP BY MONDAY MORNING...BECOMING GUSTY FROM THE WEST. THIS
COULD RESULT IN A PERIOD OF DRIFTING/BLOWING OF THE FRESHLY FALLEN
SNOW AT KRST. WITH SNOW AMOUNTS RELATIVELY SMALL THOUGH...IMPACT ON
THE VSBY WILL LIKELY BE MINIMAL.
CIGS WILL BE PROBLEMATIC AS A MIX OF MVFR/VFR CONTINUES PER LATEST
SFC OBS...AND PINPOINTING A REASON FOR THE VARIABILITY IS DIFFICULT.
WILL CONTINUE TO SIDE TOWARD MORE MVFR FOR THE OVERNIGHT
HOURS...CLIMBING TO VFR...AND THEN BREAKING OUT INTO SCT SKIES FOR
MONDAY AFTERNOON. CLOUDS WILL QUICKLY RETURN MONDAY NIGHT AS ANOTHER
SHORTWAVE TROUGH SPINS ACROSS THE REGION. COULD SEE A PERIOD OF MVFR
OVERNIGHT WITH SOME -SN.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM CST TUESDAY
FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION.....RIECK
AREA FORECAST DISCUSSION
NWS GREEN BAY WI
1144 PM CST SUN DEC 8 2013
UPDATED AVIATION PORTION FOR 06Z TAF ISSUANCE
.UPDATE...
ISSUED AT 856 PM CST SUN DEC 8 2013
CANCELLED WINTER WX ADVISORY FOR NORTHWEST PORTION OF FORECAST
AREA AS HAVE HAD GENERALLY LESS THAN AN INCH UP THERE WITH VSBYS
REMAINING IN THE 3 TO 5 MILES RANGE. EXPECT TO SEE AN INCH OR LESS
ADDITONAL ACCUMULATION OVERNIGHT THERE.
AREA OF LIGHT SNOW OVER FOX VALLEY LATE THIS EVENING ASSOCIATED
WITH SHORTWAVE DISTURBANCE MOVING ACROSS SOUTHEAST WISCONSIN.
VSBYS GENERALLY AROUND 2 MILES WITH SNOWFALL RATES A BIT HIGHER
ALONG THE LAKESHORE AS LAKE ENHANCEMENT CONTINUES THERE. VSBYS
FROM KEWAUNEE TO SOUTHEAST BROWN COUNTY...TO EAST OF OSHKOSH
BEWTEEN 1 AND 2 MILES. BACK/WESTERN EDGE OF THIS AREA OF LIGHT
SNOW APPROACHING THE FOX VALLEY THUS EXPECT LIGHT SNOW TO TAPER
OFF FROM SOUTHWEST TO NORTHEAST OVER THE NEXT FEW HOURS...EXCEPT
FOR THE LAKESHORE COUNTIES.
UPSTREAM SHORTWAVE MOVING ACROSS IOWA CONTINUED TO LOOK UNIMPRESSIVE
AS IT APPROACHES THE FORECAST AREA. DO NOT FEEL THIS FEATURE WILL
BE ABLE TO DO MUCH TO FURTHER ENHANCE LIGHT SNOW OVER THE FORECAST
AREA AFTER MIDNIGHT. LATEST RUC...NAM AND HRRR ARE ALL SUGGEST
WEAK LIFT AND VERY MINIMAL QPF AMOUNTS. WILL KEEP ADVISORY GOING
FOR NOW GIVEN LIGHT SNOW STILL FALLING OVER MUCH OF THE FORECAST
AREA. MAY TRIM ADDITIONAL COUNTIES TO THE WEST OF THE FOX VALLEY
FROM ADVISORY BEFORE MIDNIGHT IF RADAR RETURNS AND OBSERVED VSBYS
REMAIN LACKLUSTER.
HIGHEST SNOWFALL AMOUNTS HAVE GENERALLY BEEN AROUND 3 INCHES ALONG
THE LAKESHORE FROM MANITOWOC TO DOOR COUNTY. ABOUT 2 INCHES AT
NWS GREEN BAY AS OF 845 PM. JUST RECEIVED A REPORT OF 1.8 INCHES
SO FAR IN EAST GREEN BAY.
UPDATE
ISSUED AT 644 PM CST SUN DEC 8 2013
SYSTEM AFFECTING THE FORECAST AREA HAS BEEN RATHER DISORGANIZED
AND DISJOINTED THUS FAR. SO FAR...SNOWFALL AMOUNTS HAVE BEEN
AROUND AN INCH OR SO THROUGH 6 PM. HOWEVER...WATER VAPOR IMAGERY
SHOWS SOMEWHAT MORE ROBUST SHORTWAVE DISTURBANCE ENTERING
SOUTHWEST WISCONSIN. THIS FEATURE HAS HELPED TO CREATE A SOMEWHAT
MORE SOLID AND ORGANIZED AREA OF LIGHT SNOW ACROSS SOUTHEAST
WISCONSIN WITH VSBYS GENERALLY BETWEEN ABOUT 1 AND 2 MILES. THIS
AREA OF LIGHT SNOW CONTINUES TO DRIFT NORTHEAST AND WILL LIKELY CLIP
THE SOUTHEAST PORTION OF THE FOX VALLEY GENERALLY SOUTH OF A LINE
FROM OSH TO KEWAUNEE OVER THE NEXT FEW HOURS.
FURTHER AS ANTICIPATED...AN AREA OF LAKE ENHANCED SNOW CONTINUES
TO DEVELOP OVER CENTRAL LAKE MICHIGAN AND IS DRIFTING NORTHWEST.
RADAR REFLECTIVITIES HAVE BEEN GRADUALLY INCREASING AND EXPNADING
IN AREA COVERAGE OVER THE LAST HOUR. APPEARS ACTIVITY AHEAD OF
APPROACHING SHORTWAVE ENTERING SOUTHWEST WISCONSIN CONTRIBUTING TO
LES ENHANCEMENT OVER CENTRAL LAKE MICHIGAN VIA SEEDER-FEEDER
MECHANISM.
THUS...EXPECT TO SEE SOMEWHAT HIGHER SNOWFALL RATES ACROSS THE
FOX VALLEY THIS EVENING IN ASSOCIATION WITH SHORTWAVE MOVING
ACROSS SOUTHEAST WISCONSIN AND LAKE ENHANCEMENT OFF LAKE MICHIGAN.
COULD SEE ANOTHER INCH OR PERHAPS TWO MY MIDNIGHT ESPECIALLY
SOUTHEAST OFF A LINE FROM STURGEON BAY TO GREEN BAY TO OSHKOSH.
LOOKING FURTHER UPSTREAM...PRIMARY SHORTWAVE DISTURBANCE NOW
ENTERING NORTHWEST IOWA. THIS FEATURE IS ALSO FORECAST TO MOVE
ACROSS THE SOUTHERN WISCONSIN AFTER MIDNIGHT AND MAY HELP TO KEEP
SOME LIGHT SNOW GOING AFTER MIDNIGHT ESPECIALLY OVER THE
SOUTHEAST HALF OF THE FORECAST AREA. HOWEVER...LOOKING AT SURFACE
OBSERVATIONS OVER IOWA...VSBYS NOT VERY LOW AND WERE IN THE 2 TO 4
MILE RANGE. IN FACT THE LATEST HRRR AND RUC FORECASTS SEEM TO
SIGNIFICANTLY DISSOLVE THE AREA OF QPF AS THIS FEATURE APPROACHES
WISCONSIN.
FORCING ACROSS THE NORTHWEST THIRD OF THE FORECAST AREA NOT
EXPECTED TO BE VERY STRONG AND THUS FAR SNOWFALL RATES UP THERE
HAVE BEEN QUITE LIGHT WITH VSBYS GENERALLY IN THE 2 TO 4 MILE
RANGE. WILL SEE HOW THE SHORTWAVE MOVING OUT OF IOWA EVOLVES LATER
THIS EVENING...BUT IF CURRENT TRENDS CONTINUE MAY NEED TO CANCEL ADVISORY
UP THERE.
FOR NOW WILL KEEP ADVISORY GOING OVER ENTIRE FORECAST AREA AND
WILL REVIST A BIT LATER THIS EVENING. BOTTOM LINE IS IT APPEARS
MOST SIGNIFICANT SNOWFALL WILL BE FOCUSED OVER THE FOX VALLEY AND
LAKESHORE. APPEARS FINAL SNOWFALL TOTALS WILL BE ON THE LOW END OF
CURRENT FORECAST.
&&
.SHORT TERM...TONIGHT AND MONDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW ONE SHORTWAVE
TROUGH MOVING INTO SOUTHWEST WISCONSIN THIS AFTERNOON...WHILE
ANOTHER WAVE NOW ENTERING THE CENTRAL GREAT PLAINS. AHEAD OF THE
FORMER SHORTWAVE...WEAK ISENTROPIC ASCENT IS PRODUCING A WIDESPREAD
SWATH OF LIGHT SNOW ACROSS THE STATE. THE BETTER SNOWS WITH THE
FIRST WAVE ARE STILL ACROSS IOWA AT THE MOMENT...WHERE VSBYS ARE
DOWN TO A HALF MILE AND WIDESPREAD 1-2 INCHES ARE BEING REPORTED SO
FAR. FURTHER CONCERNS RESIDE ALONG THE LAKE SHORE WHERE LAKE
ENHANCEMENT IS OCCURRING OVER CENTRAL AND SOUTHERN PARTS OF THE LAKE
MICHIGAN SHORELINE. EARLIER REPORTS SHOWED 1-1.5 INCH PER HOUR
SNOWFALL RATES IN THOSE LAKE ENHANCED BANDS. ONE OF THESE BANDS IS
APPROACHING MANITOWOC...BUT APPEARS TRANSIENT IN A LOW LEVEL
CONVERGENT ZONE. LOW LEVEL WINDS ARE JUST STARTING TO TURN TO THE
SOUTHEAST SO WILL NEED TO WATCH THESE TRENDS FOR THE REST OF THE
AFTERNOON. AS THE SHORTWAVES MOVE ACROSS THE ARE TONIGHT...SNOWFALL
AMOUNTS AND IMPACTS ARE THE MAIN FORECAST CONCERN.
TONIGHT...SHORTWAVE TROUGH OVER COLORADO WILL QUICKLY EJECT
NORTHEAST A DRIVE A STRENGTHENING...ALTHOUGH STILL RELATIVELY
WEAK...AREA OF LOW PRESSURE FROM THE CENTRAL GREAT PLAINS AND ACROSS
SOUTHEAST WISCONSIN TONIGHT. FORCING AHEAD OF THE SHORTWAVE IN THE
FORM OF -DIVQ...UPPER DIVERGENCE...AND ISENTROPIC ASCENT IS ONLY
MODEST...BUT BUFKIT SOUNDINGS FROM THE NAM/GFS/SREF ALL INDICATE A
150-200MB DEEP DENDRITIC GROWTH ZONE BETWEEN APPROX 850-650MB OVER
CENTRAL AND NORTHEAST WISCONSIN. THIS SUGGESTS THAT WHATEVER WEAK
TO MODERATE LIFT THAT OCCURS...SNOW FLAKE PRODUCTION WILL BE VERY
EFFICIENT AND SNOW TO LIQUID RATIOS WILL BE QUITE HIGH. GENERALLY
WENT WITH A 19-20:1 RATIO...ALTHOUGH A LITTLE LOWER NEAR THE LAKE
MICHIGAN SHORELINE WHERE ONSHORE FLOW WILL LEAD TO SLIGHTLY WARMER
LOW LEVEL THERMAL PROFILES. THE BULK OF THE SNOW LOOKS TO OCCUR IN
A COUPLE WAVES. THE FIRST WILL ARRIVE LATE THIS AFTERNOON INTO EARLY
THIS EVENING FROM THE FIRST AREA OF SNOW OVER IOWA AND SE
MINNESOTA...FOLLOW BY THE MAIN SHORTWAVE AND SURFACE LOW OVER
COLORADO. PLENTY OF 1-3" INCH REPORTS UPSTREAM OVER IOWA...AND FEW
4-6 INCH REPORTS OVER EASTERN NEBRASKA AS WELL. WILL INCREASE
AMOUNTS A LITTLE OVER N-C WISCONSIN TO AROUND 3 INCHES. THE PRIMARY
CONCERN THOUGH WILL BE ALONG THE LAKE SHORE WHERE WINDS WILL BE
TURNING TO THE EAST AND SOUTHEAST THIS EVENING. THE LAKE ENHANCEMENT
OVER SOUTHEAST WISCONSIN APPEARS TO BE FLUCTUATING...AS A CONVERGENT
BAND LIFTS NORTH. BUT EARLIER SNOWFALL RATES WHERE ENHANCEMENT TOOK
PLACE ARE ALARMING. LOOKS LIKE A GOOD 9-12 HOURS OF ENHANCEMENT
POSSIBLE OVER NORTHEAST WISCONSIN. WILL GO WITH WIDESPREAD 2-4
INCHES EXCEPT NEAR THE LAKESHORE WHERE 5-6 INCHES WILL BE POSSIBLE.
HEADLINES WILL REMAIN THE SAME...AND WILL PASS ALONG LAKE
ENHANCEMENT CONCERNS TO THE EVENING SHIFT.
MONDAY...THE SNOW WILL BE ENDING EARLY MONDAY MORNING OVER NORTHEAST
WISCONSIN AS THE SURFACE LOW PULLS AWAY. WEST WINDS WILL BE
STRENGTHENING IN THE WAKE OF THE LOW AND COLD ADVECTING AT THE SAME
TIME. TEMPS WILL REMAIN NEARLY STEADY OR FALL SLIGHTLY DURING THE
DAY...DESPITE CLEARING TAKING PLACE. WITH WINDS GUSTING TO 30
MPH...APPARENT TEMPS WILL BE FALLING TO NEAR 20 BELOW ZERO OVER
CENTRAL AND NORTH-CENTRAL WISCONSIN DURING THE AFTERNOON. WILL
LIKELY NEED WIND CHILL HEADLINES...BUT WITH THE ONGOING SNOW
ADVISORY...WILL NOT ISSUE ANOTHER HEADLINE. MORNING TO MIDDAY HIGHS
IN THE MIDDLE SINGLE DIGITS NORTH TO THE UPPER TEENS NEAR THE LAKE
SHORE.
.LONG TERM...MONDAY NIGHT THROUGH SUNDAY
ISSUED AT 232 PM CST SUN DEC 8 2013
VERY COLD AIR WILL REMAIN FIRMLY ENTRENCHED ACROSS THE AREA
MONDAY NIGHT. EXPECT WINDS CHILLS TO DROP TO AROUND 25 BELOW
ACROSS THE NORTH. HOWEVER...TEMPERATURES ARE EXPECTED TO
MODIFY SOME LATE MONDAY NIGHT DUE TO INCREASING CLOUDINESS
AND AHEAD OF APPROACHING SYSTEM. INCREASED CHANCES OF SNOW
ACROSS THE NORTHWEST HALF OF THE FORECAST AREA. INCREASED SNOW
CHANCES SIGNIFICANTLY ON TUESDAY MORNING AS SYSTEM MOVES ACROSS
THE AREA. ALSO...PRECIPITATION TOTALS WILL BE LIGHT...SNOW RATIOS
WOULD SUGGEST LESS THAN AN INCH OF NEW SNOW TUESDAY MORNING. THE
HIGHEST SNOWFALL TOTALS WILL BE ACROSS THE NORTH.
MOST OF THE MODELS NOW BRING CLIPPER SYSTEM SOUTH OF THE AREA
TUESDAY NIGHT. THE ONLY EXCEPTION WAS THE ECMWF...THUS WILL CONTINUE
CHANCES ACROSS THE SOUTHERN HALF OF THE FORECAST AREA. THE GFS MODELS
HAS BEEN WAFFLING ON NORTHWARD EXTENT OF THE PRECIPITATION FIELD. VERY
COLD AIR IS EXPECTED WEDNESDAY MORNING. ANOTHER SYSTEM EXPECTED TO
PASS ACROSS THE NORTH THURSDAY/THURSDAY NIGHT. LOW CONFIDENCE ON WHEN
THIS SYSTEM WOULD BRING A SMALL CHANCE OF LIGHT SNOW DURING THIS PERIOD.
CURRENT FORECAST HAS LIGHT SNOW IN THE FORECAST THURSDAY NIGHT...BUT
LATER SHIFTS MAY NEED TO SPEED UP THE SNOW AND ADD A CHANCE TO THE
THURSDAY PERIOD. THE ARCTIC AIR WILL MODIFY FRIDAY INTO NEXT WEEKEND
WITH HIGHS IN THE UPPER TEENS TO MIDDLE 20S.
&&
.AVIATION...FOR 06Z TAF ISSUANCE
ISSUED AT 1144 PM CST SUN DEC 8 2013
WEAK LOW PRESSURE WILL CONTINUE TO MOVE EAST OF THE FORECAST AREA
OVERNIGHT. LIGHT SNOW WITH GENERALLY MVFR CIGS AND VSBYS WILL
PREVAIL OVER MOST OF THE FORECAST AREA THROUGH 12Z MONDAY. FEW
AREAS OF IFR CIGS OVER FOX VALLEY AND LAKESHORE WHERE LIGHT SNOW
WILL BE A BIT HEAVIER THROUGH ABOUT 09Z. MVFR CIGS TO PERSIST
UNTIL ABOUT 18Z MONDAY AND WILL BECOME SCT FROM WEST TO EAST
DURING THE AFTERNOON. WESTERLY BOUNDARY LAYER WINDS WILL INCREASE
SUBSTANTIALLY BY LATE MORNING WITH GUSTS OF 25 TO 30 MPH DURING
THE AFTERNOON.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 6 AM CST MONDAY FOR WIZ013-020>022-
030-031-035>040-045-048>050-073-074.
&&
$$
UPDATE.........ESB
SHORT TERM.....MPC
LONG TERM......ECKBERG
AVIATION.......ESB
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
759 AM EST MON DEC 9 2013
.SYNOPSIS...
SURFACE WEDGE FLOW WILL BEGIN TO BREAK DOWN TODAY AHEAD OF ANOTHER
APPROACHING COLD FRONT. THIS COLD FRONT WILL SLOWLY MOVE THROUGH
LATE TONIGHT AND INTO TUESDAY...AND STALL JUST TO OUR SOUTH
WEDNESDAY. DRY HIGH PRESSURE IS EXPECTED TO RETURN THE MID TO LATE
WEEK...WITH ANOTHER SYSTEM ARRIVING NEXT WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CONFIDENCE IS INCREASING FOR WEDGE TO HOLD ACROSS THE REGION
THROUGH THE DAY. LATEST HOURLY RAP TEMPERATURE DATA SUPPORTS LOCAL
WEDGE SCHEME AND KEEPS COLD AIR IN PLACE. STRONG SOUTH LOW LEVEL
FLOW IN THE BOUNDARY LAYER ISENTROPIC LIFT RESULTING DRIZZLE AT
TIMES...BUT WARM FRONT PROBABLY REMAINS TO THE SOUTH OF THE
REGION. SO LOWERED TEMPERATURES AGAIN SEVERAL DEGREES...
STRONGEST ISENTROPIC LIFT ACROSS PIEDMONT/NORTH MIDLANDS...SO
EXPECT HIGHER CHANCE RAIN IN THAT REGION...LOWER CHANCE SOUTHEAST
MIDLANDS/CSRA.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
CHANCES FOR RAIN WILL INCREASE DURING THE OVERNIGHT PERIOD AS THE
AXIS OF HIGHER PRECIPITABLE WATER VALUES AND MOISTURE TRANSPORT
GRADUALLY SHIFT EASTWARD AHEAD OF AN APPROACHING COLD FRONT. WILL
CONTINUE THE GRADIENT IN POPS FROM LIKELY NORTHWEST TO LOW CHANCE
IN THE SOUTHEASTERN PART OF THE FORECAST AREA.
FAST MOVING SHORTWAVE ENERGY WILL PUSH EASTWARD INTO THE TENNESSEE
AND OHIO VALLEYS LATE TONIGHT INTO TUESDAY WHICH WILL PUSH THE
COLD FRONT ACROSS THE FORECAST AREA LATE TUESDAY MORNING INTO
TUESDAY AFTERNOON. POOLING OF MOISTURE ON THE FRONT IS EXPECTED
WITH PRECIPITABLE WATER VALUES RISING TO AROUND 1.5 INCHES. A
STRONG 50 KT LOW LEVEL JET IS FORECAST TO PRECEDE THE FRONT WHILE
SHIFTING ACROSS THE REGION AND COMBINING WITH INCREASED LOW LEVEL
CONVERGENCE AND INCREASING UPPER FORCING AS THE FORECAST AREA
FALLS WITHIN THE RIGHT ENTRANCE REGION OF THE UPPER JET. THEREFORE
WILL TRANSITION LIKELY POPS ACROSS THE FORECAST AREA TUESDAY FROM
WEST TO EAST WITH A SHARP DECREASE IN POPS LATE TUESDAY AFTERNOON
AS THE UPPER FLOW BECOMES MORE ZONAL WHICH WILL PUSH THE FRONT EAST
OF THE AREA WITH DRIER AIR WORKING IN FROM THE WEST. TEMPERATURES
WILL REBOUND TO ABOVE NORMAL VALUES AHEAD OF THE FRONT WITH STRONG
MIXING OF WARMER AIR ALOFT DOWN TO THE SURFACE.
SKIES WILL CLEAR FROM WEST TO EAST TUESDAY AFTERNOON AND NIGHT AS
LOW LEVEL FLOW BECOMES NORTHWESTERLY AS SURFACE HIGH PRESSURE
BUILDS OVER THE AREA USHERING IN MUCH DRIER AIR TO THE REGION.
COLD ADVECTION TUESDAY NIGHT WILL ALLOW LOW TEMPERATURES TO FALL
INTO THE 30S ACROSS THE REGION.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
MEDIUM RANGE MODELS HAVE COME INTO BETTER AGREEMENT IN KEEPING THE
STALLED FRONTAL BOUNDARY JUST TO OUR SOUTH ON WEDNESDAY AND
CONFINING ANY ADDITIONAL PRECIPITATION ASSOCIATED WITH AN INVERTED
TROUGH OFF THE COAST THROUGH WEDNESDAY NIGHT SOUTH AND EAST OF THE
FORECAST AREA. WILL KEEP DRY FORECAST WEDNESDAY THROUGH FRIDAY AS
PRECIPITABLE WATER VALUES REMAIN BELOW 0.5 INCHES. TEMPERATURES
WILL BE BELOW NORMAL WEDNESDAY THROUGH FRIDAY WITH COOL HIGH
PRESSURE SETTLED OVER THE SOUTHEAST.
UNSETTLED WEATHER IS EXPECTED TO RETURN BY THE WEEKEND WITH GFS
AND ECMWF COMING INTO BETTER AGREEMENT. A CUT OFF UPPER LOW OVER
THE FOUR CORNERS REGION ON FRIDAY WILL OPEN UP AND PHASE WITH A
DIGGING NORTHERN STREAM TROUGH OVER THE CENTRAL PLAINS AND
MISSISSIPPI VALLEY BY FRIDAY NIGHT. MOISTURE WILL INCREASE QUICKLY
AHEAD OF THE APPROACHING SYSTEM FRIDAY NIGHT WITH SOUTHERLY LOW
LEVEL FLOW WITH RAIN EXPECTED TO OVERSPREAD THE REGION BY SATURDAY
AS THE TROUGH MOVES EASTWARD INTO THE MID ATLANTIC REGION. WILL
KEEP CHANCE POPS FRIDAY NIGHT BUT HAVE INCREASED POPS TO LIKELY
FOR SATURDAY...AND HOLD ON TO CHANCE POPS SUNDAY WITH LOW
CONFIDENCE IN THE EVENTUAL SPEED OF THIS SYSTEM. DO NOT EXPECT ANY
PRECIP TYPE ISSUES DESPITE SOME INITIALLY DRY AIR TO OVERCOME.
TEMPERATURES SAT/SUN SHOULD CONTINUE TO BE NEAR OR BELOW NORMAL.
&&
.AVIATION /13Z MONDAY THROUGH FRIDAY/...
STRONG WEDGE CONDITIONS CONTINUE ACROSS THE AREA THIS MORNING.
ALL TAF SITES REMAIN IFR/LIFR DUE TO CEILINGS AND SOME FOG AND
DRIZZLE. MODEL TIME SECTIONS CONTINUE TO SHOW ABUNDANT LOW LEVEL
MOISTURE THROUGH THE TAF PERIOD. MODELS STILL TRY TO HOLD ON TO
THE WEDGE THROUGH MIDDAY. WILL KEEP LOW CONDITIONS IFR/LIFR FOR
MUCH OF THE PERIOD...BECOMING MVFR BY THE AFTERNOON. LATEST
GUIDANCE CONTINUES TO SHOW CONDITIONS DROPPING ONCE AGAIN TO
IFR/POSSIBLE LIFR AFTER 00Z TUESDAY.
EXTENDED AVIATION OUTLOOK..A COLD FRONT WILL SLOWLY MOVE THROUGH
THE AREA TUESDAY. THERE WILL BE A CHANCE OF SHOWERS AND ASSOCIATED
RESTRICTIONS WITH THE FRONT. THE FRONT IS FORECAST TO STALL JUST
TO OUR SOUTH WEDNESDAY WITH HIGH PRESSURE BUILDING EASTWARD TO OUR
NORTH. A RETURN TO VFR CONDITIONS POSSIBLE WEDNESDAY...BUT
CONFIDENCE IS LOW. BY THURSDAY...HIGH PRESSURE BEGINS TO DOMINATE
THE AREA AND VFR CONDITIONS ARE MORE CONFIDENT.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
623 AM EST MON DEC 9 2013
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTH THROUGH THE AREA TODAY...THEN A COLD
FRONT WILL MOVE INTO THE REGION FROM THE NORTHWEST TUESDAY. HIGH
PRESSURE WILL BUILD FROM THE WEST DURING THE MID TO LATE WEEK
PERIOD. ANOTHER FRONTAL SYSTEM WILL IMPACT THE REGION DURING THE
WEEKEND.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR THE SUNRISE UPDATE...DENSE FOG IS SPREADING INLAND SO THE
DENSE FOG ADVISORY WILL BE RETAINED. LATEST RAP AND NAM-WRF DATA
SUGGEST THE CAD WILL BE SLOWER TO ERODE THAN EXPECTED AND SHOWS
HIGHS WELL INLAND STRUGGLING TO REACH THE MID 60S. HAVE OPTED TO
LOWER HIGHS BY A CATEGORY INTO THE UPPER 60S ACROSS THE FAR
INTERIOR ROW OF ZONES AND IF THE H3R PROVES CORRECT...THEN FAR
INLAND AREAS STRETCHING BACK INTO THE CHARLESTON METRO AREA WILL
ONLY PEAK IN THE LOWER-MID 60S. OBVIOUSLY THERE IS A BIG BUST
POTENTIAL FOR THE TEMPERATURE FORECAST FOR TODAY...NOT UNCOMMON
FOR CAD EROSION.
IMPRESSIVE COLD AIR DAMMING /CAD/ REMAINS IN PLACE THIS MORNING
WITH WIDESPREAD FOG...LOW CEILINGS AND INTERMITTENT DRIZZLE.
PRESSURE FALLS ARE BEGINNING TO INCREASE ACROSS THE CORE OF THE
CAD REGION PER 09/09Z ISALLOBARIC ANALYSIS SUGGESTING THE WEDGE
IS BEGINNING TO STEADILY WEAKEN. AREA WEBCAMS AND SURFACE
OBSERVATIONS SHOW STRATUS BUILD DOWN IS OCCURRING WHICH SHOULD
TRANSLATE TO WIDESPREAD DENSE FOG PRIOR TO SUNRISE AS CEILINGS
REACH THE GROUND. THE ONLY CONCERN IS THAT SURFACE WINDS ARE
RUNNING A TAD HIGHER THAN EXPECTED...WHICH MAY LIMIT VISIBILITIES
SOMEWHAT...BUT WINDS ARE FORECAST TO DROP OFF OVER THE NEXT FEW
HOURS. A DENSE FOG ADVISORY REMAINS IN EFFECT FOR ALL ZONES UNTIL
10 AM. FOG MAY LINGER ALONG THE BEACHES A BIT LONGER WITH FOG
LIKELY REMAINING TRAPPED UNDERNEATH A STRONG MARINE INVERSION.
AS COLD AIR DAMMING BREAKS DOWN...A WARM FRONT WILL MOVE STEADILY
NORTH TODAY ALLOWING A SIGNIFICANT RECOVERY IN TEMPERATURES FOR
ALL AREAS. HIGHS IN THE MID-UPPER 70S LOOK QUITE REASONABLE GIVEN
THE AMOUNT OF WARM AIR NOTED ATOP THE COLD AIR WEDGE. ISOLATED TO
SCATTERED SHOWERS LOOK TO INCREASE LATER THIS AFTERNOON AS WARM
AIR ADVECTION AND LOW-LEVEL JETTING INTENSIFY AHEAD OF AN
APPROACHING COLD FRONT. POPS WILL BE LIMITED TO 20-30
PERCENT...HIGHEST ACROSS THE FAR WESTERN AREAS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...ONGOING WARM AIR ADVECTION AND LOW-LEVEL JETTING WILL
KEEP TEMPERATURES RATHER MILD FOR DECEMBER WITH LOWS IN THE
LOWER-MID 60S...EXCEPT UPPER 50S ACROSS PORTIONS OF ALLENDALE-
SCREVEN-JENKINS COUNTIES. RAIN CHANCES WILL REMAIN RATHER STATIC
FOR MUCH OF THE NIGHT...WITH POPS 20-30 PERCENT...BUT WILL BEGIN
TO RAMP UP CLOSER TO 40 PERCENT ACROSS THE FAR WEST JUST BEFORE
SUNRISE TUESDAY. MORE FOG WILL BE POSSIBLE AFTER MIDNIGHT...BUT
CURRENT INDICATIONS ARE THAT THE FOG WILL NOT BE DENSE. THE ONLY
EXCEPTION COULD BE ALONG THE COAST IF SEA FOG IMPACTS COASTAL
COMMUNITIES.
TUESDAY...A COLD FRONT WILL PROGRESS THROUGH THE FORECAST AREA
DURING THE DAYTIME HOURS AND LIKELY BE OFFSHORE BY SUNSET. WILL
CONTINUE TO INDICATE THE BEST RAIN POTENTIAL OF THE PERIOD
TUESDAY...WITH POPS UP TO 50 PERCENT AS THE FRONTAL ZONE CROSSES
SOUTHEAST SOUTH CAROLINA AND SOUTHEAST GEORGIA. CONSIDERING GOOD
AGREEMENT IN NUMERICAL MODEL SOLUTIONS...SUBSEQUENT FORECAST
ISSUANCES MAY BE ABLE TO RAISE RAIN CHANCES EVEN HIGHER INTO THE
LIKELY CATEGORY. THE WARMING EFFECTS OF PRE-FRONTAL COMPRESSION...AS
WELL AS PERSISTENT SOUTHWEST/WEST FLOW THROUGH THE AFTERNOON...WILL
SUPPORT HIGH TEMPERATURES ABOVE SEASONAL NORMALS IN THE UPPER 60S
WEST TO LOWER 70S EAST. SHOWER COVERAGE WILL QUICKLY DIMINISH FROM
WEST TO EAST IN THE WAKE OF THE DEPARTING COLD FRONT AFTER
SUNSET...AND WITH COLD ADVECTION QUICKLY INITIATING...EXPECT
TEMPERATURES TO RAPIDLY FALL DURING THE EVENING AND OVERNIGHT HOURS.
LOW TEMPERATURES WILL RANGE FROM THE UPPER 30S INLAND TO THE MID 40S
NEAR THE COAST AND SOUTH OF INTERSTATE 16.
WEDNESDAY...THE INITIAL AREA OF SURFACE HIGH PRESSURE BUILDING IN
THE WAKE OF THE COLD FRONT WILL ACTUALLY DIMINISH AS THE DAY
PROGRESSES...TO BE REPLACED BY A NOTABLY STRONGER SURFACE HIGH
FOLLOWING SHORTWAVE ENERGY WITHIN BROAD UPPER TROUGHING. NORTHEAST
FLOW WILL STILL CONTINUE WITHIN THIS TRANSITIONING PATTERN AND
SUPPORT A SIGNIFICANT COOLING TREND. EXPECT HIGH TEMPERATURES TO
BE SUPPRESSED IN THE MID 50S NORTH TO THE LOW 60S FAR
SOUTH...WHILE LOW TEMPERATURES REACH SIMILAR VALUES TO THE
PREVIOUS NIGHT. SOME CONVERGENCE OVER THE NEARBY ATLANTIC WATERS
AND ALONG THE PERIPHERY OF THE BUILDING SURFACE HIGH COULD ALSO
SUPPORT ISOLATED TO SCATTERED SHOWER ACTIVITY OVER THE MARINE
ZONES. HAVE MAINTAINED A CORRIDOR OF SLIGHT CHANCE POPS ACROSS THE
EASTERN THIRD OF THE FORECAST AREA TO ACCOUNT FOR A SMALL
POTENTIAL OF SOME INLAND SHOWER INTRUSION.
THURSDAY...THE AMPLIFYING SHORTWAVE TROUGH WILL QUICKLY SLIP OFF
THE EAST COAST...WHILE THE STRONGER DRY HIGH PRESSURE BUILDS OVER
THE MID ATLANTIC STATES AND CAROLINAS. ANOTHER WAVE OF COLD
ADVECTION WILL KEEP TEMPERATURES WELL BELOW SEASONAL NORMALS ONCE
AGAIN...WITH HIGHS PEAKING ONLY IN THE 50S DESPITE SCATTERING SKY
COVER AND IMPROVED INSOLATION. RAIN CHANCES WILL REMAIN BELOW 15
PERCENT THROUGH THE DAY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
SURFACE HIGH PRESSURE WILL STEADILY TRACK OFF THE COAST AND INTO
THE ATLANTIC WATERS THROUGH FRIDAY...AHEAD OF SOUTHERN STREAM
SHORTWAVE ENERGY LIFTING INTO THE TENNESSEE VALLEY. MEDIUM RANGE
MODELS REMAIN IN NOTABLE DISAGREEMENT REGARDING THE STRENGTH AND
TRACK OF SYNOPTIC SCALE FEATURES ON SATURDAY...WITH THE GENERAL
CONSENSUS BEING VARIATIONS OF A FRONTAL SYSTEM CROSSING THE
FORECAST AREA ON SATURDAY. COOL TEMPERATURES AND RAIN-FREE
CONDITIONS WILL CONTINUE FOR THE DAYTIME HOURS ON FRIDAY...BEFORE
RAIN CHANCES QUICKLY INCREASE FROM WEST TO EAST FRIDAY NIGHT AND
PEAK SATURDAY AFTERNOON. TEMPERATURES ON SATURDAY COULD BE A FEW
DEGREES WARMER THAN PREVIOUS DAYS...BUT MUCH DEPENDS ON THE SPEED
WITH WHICH THE FRONT MOVES THROUGH THE FORECAST AREA. ONCE THE
COLD FRONT SHIFTS OFFSHORE BY SUNDAY MORNING...THE ASSOCIATED
SURFACE LOW TO THE NORTH WILL INTENSIFY RAPIDLY OFF THE NEW
ENGLAND COAST. THE SOUTHEAST STATES WILL ONCE AGAIN BECOME LOCATED
WITHIN DRIER HIGH PRESSURE BEHIND THE DEPARTING COLD FRONT...WITH
RAIN CHANCES EXPECTED TO STEADILY DECREASE SUNDAY. TEMPERATURES
WILL UNDERGO ANOTHER COOLING TREND FOR SUNDAY AND MONDAY.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
LIFR CONDITIONS PERSIST AT BOTH TERMINALS WITH CIGS/VSBYS AT
AIRFIELD MINIMUMS. LIFR CONDITIONS WILL PERSIST THROUGH MID-
MORNING BEFORE SLOWLY LIFTING AS COLD AIR DAMMING BREAKS DOWN AND
A WARM FRONT MOVES NORTH. THERE IS MUCH UNCERTAINTY ON THE EXACT
TIMING OF WHEN CONDITIONS WILL RISE ABOVE IFR AND MVFR
THRESHOLDS...BUT CURRENT THINKING FOR KCHS IS 16Z FOR IFR AND
1730Z FOR MVFR. AT KSAV...EXPECT LIFR THROUGH 15Z AND MVFR THROUGH
1630Z. VFR FOR LATE MORNING INTO THE AFTERNOON. LOW CLOUDS AND FOG
ARE POSSIBLE AGAIN TONIGHT. CAPPED CONDITIONS AT LOW-END MVFR FOR
NOW...HOWEVER IFR CONDITIONS ARE A POSSIBILITY.
EXTENDED AVIATION OUTLOOK...LOW TO MODERATE RISK OF OCCASIONAL
FLIGHT RESTRICTIONS WITH A COLD FRONT AND ASSOCIATED SHOWERS
TUESDAY AFTERNOON/EVENING.
&&
.MARINE...
TODAY...RECENTLY EXPANDED THE MARINE DENSE FOG ADVISORY TO INCLUDE
THE REMAINING SOUTH CAROLINA NEARSHORE ZONES AND EXTENDED THE
EXPIRATION TIME TO 10 AM. ITS UNCLEAR EXACTLY FAR OFFSHORE THE
MOST DENSE FOG RESIDES...BUT THERE IS ENOUGH EVIDENCE IN SATELLITE
DATA AND COASTAL WEBCAMS TO JUSTIFY KEEPING THE ADVISORY IN PLACE.
THE FOG WILL LIKELY LINGER FOR MUCH OF THE DAY AND POTENTIALLY
BECOME INTERMINGLED WITH SEA FOG THIS AFTERNOON AS INCREASING
DEWPOINTS ADVECT OVER THE COOLER SHELF WATERS. OTHERWISE...
NORTHEAST WINDS WILL GRADUALLY TURN SOUTHERLY LATER THIS MORNING
AND INCREASE TO 10-15 KT AS A WARM FRONT MOVES NORTH. SEAS WILL BE
2-4 FT.
TONIGHT...SOUTH WINDS 10-15 KT WILL BECOME SOUTHWEST AND INCREASE
TO 15-20 KT AS A COLD FRONT APPROACHES FROM THE WEST. THERE WILL
LIKELY BE A CONTINUED RISK FOR AT LEAST PATCHY SEA FOG...BUT THE
HIGHER WINDS SHOULD KEEP VISIBILITIES ABOVE 1 NM. SEAS WILL BUILD
TO 3-5 FT OFFSHORE WATERS AND CHARLESTON COUNTY NEARSHORE WATERS
TO 2-4 FT ELSEWHERE.
TUESDAY THROUGH FRIDAY...A COLD FRONT WILL MOVE THROUGH THE
FORECAST AREA ON TUESDAY...WITH MODERATE SOUTHERLY FLOW VEERING TO
THE NORTH OVERNIGHT. MARGINAL SMALL CRAFT ADVISORY CONDITIONS ARE
POSSIBLE WITHIN COLD ADVECTION FOLLOWING THE FRONTAL PASSAGE
TUESDAY NIGHT INTO EARLY WEDNESDAY. A BETTER CHANCE FOR ADVISORY
CONDITIONS WILL THEN OCCUR THURSDAY...AS A STRONGER HIGH PRESSURE
CENTER BUILDS INTO THE REGION AND TIGHTENS THE GRADIENT OVER THE
WATERS.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR GAZ087-088-
099>101-114>119-137>141.
SC...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR SCZ040-
042>045-047>052.
MARINE...DENSE FOG ADVISORY UNTIL 10 AM EST THIS MORNING FOR AMZ330-350-
352-354.
&&
$$
ST/WMS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
927 AM EST MON DEC 9 2013
.UPDATE...
THE NEAR TERM AND AVIATION SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 AM EST MON DEC 9 2013
HIGH PRESSURE WILL BRIEFLY MOVE INTO THE AREA TODAY BUT ANOTHER
UPPER DISTURBANCE WILL PROVIDE A CHANCE FOR SNOW FOR PARTS OF
CENTRAL INDIANA TONIGHT AND EARLY TUESDAY. AN AREA OF LOW PRESSURE
WILL THEN BRING A SMALL CHANCE FOR SNOW TO OTHER PARTS OF THE AREA
WEDNESDAY. COLDER AIR WILL THEN FLOW IN FOR THURSDAY.
TEMPERATURES WILL MODERATE BY THE WEEKEND BUT YET ANOTHER SYSTEM
WILL BRING CHANCES FOR PRECIPITATION FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /TODAY/...
ISSUED AT 919 AM EST MON DEC 9 2013
INTRODUCING FLURRIES INTO FORECAST THROUGH MID AFTERNOON GIVEN
WEAK RADAR RETURNS COUPLED WITH SURFACE OBSERVED LIGHT SNOW
OCCURRING. DO NOT EXPECT ACCUMULATION THOUGH GIVEN NO VSBY DROP
ACCOMPANYING CURRENT SNOW AND FLAKES QUITE SMALL.
CLEARING ACROSS WC AND NW IL SHOULD WORK ITS WAY INTO WESTERN
COUNTIES BY LATE AFTERNOON AS HIGH PRESSURE BUILDS IN BUT RETURN
OF HIGH CLOUDS FROM SOUTHERN SYSTEMS APPROACH TO RETURN HIGHER
DECKS BY NIGHTFALL.
TEMPS TO HOLD FAIRLY STEADY THROUGH THE DAY GIVEN CLOUD DECK
HOLDING AND COLD ADVECTION BEGINNING TO TAKE PLACE.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EST MON DEC 9 2013
FOCUS IS ON CHANCES FOR PRECIPITATION THROUGH THE PERIOD. MODELS ARE
IN DECENT AGREEMENT WITH THE BIG PICTURE SO USED A BLEND FOR MOST
PERIODS.
TONIGHT ISENTROPIC LIFT INCREASES ONCE AGAIN IN ADVANCE OF AN UPPER
WAVE. BEST FORCING AND MOISTURE LOOK TO BE CONFINED TO THE SOUTHERN
2/3 OF THE FORECAST AREA. THERE LOOKS TO BE SOME FRONTOGENETICAL
FORCING ACROSS MAINLY THE SOUTHERN HALF OF THE AREA AS WELL.
NAM IS FARTHEST NORTH WITH PRECIPITATION WITH OTHERS A BIT FARTHER
SOUTH. THIS LOOKS TO BE ANOTHER CASE WITH A VERY SHARP CUTOFF OF
POTENTIAL ACCUMULATING SNOW AND NO SNOW AT ALL. THUS CONFIDENCE IS
ONLY LOW TO MEDIUM IN NORTHERN PLACEMENT OF POPS...ESPECIALLY NORTH.
WILL GO DRY IN THE FAR NORTHWEST TONIGHT WITH A QUICK TRANSITION TO
HIGH CHANCE CATEGORY POPS SOUTH. IF NAM IS RIGHT WILL HAVE TO BUMP
TO LIKELY POPS ACROSS THE SOUTH WITH LATER FORECASTS. WILL CONTINUE
TO WATCH CLOSELY. POTENTIAL EXISTS FOR A QUICK INCH OR SO IN SOME
AREAS ACROSS THE SOUTH.
FORCING QUICKLY ENDS LATE TONIGHT INTO EARLY TUESDAY SO ONLY WENT
SLIGHT CHANCE POPS EARLY TUESDAY ACROSS THE FAR SOUTHEAST. OTHERWISE
CLOUDS WILL DECREASE TUESDAY AS SYSTEM EXITS. HOWEVER CLOUDS WILL
INCREASE ACROSS THE NORTH TUESDAY NIGHT AS THE NEXT SYSTEM
APPROACHES.
AN AREA OF LOW PRESSURE WILL MOVE ACROSS THE LOWER GREAT LAKES
WEDNESDAY. BEST FORCING AND MOISTURE REMAIN NORTH OF THE FORECAST
AREA...BUT LOOKS LIKE JUST ENOUGH MIGHT SNEAK INTO THE FAR NORTHERN
FORECAST AREA TO GO SLIGHT CHANCE POPS. DRY CONDITIONS WILL PREVAIL
WEDNESDAY NIGHT AS SYSTEM EXITS.
LOOKING AT TEMPERATURES...MAV LOOKS TOO COLD TONIGHT GIVEN EXPECTED
CLOUD COVER WITH NEXT SYSTEM. WENT CLOSER TO WARMER MET. ON TUESDAY
MAV LOOKS TOO WARM MANY AREAS GIVEN SOME COLD ADVECTION DURING PART
OF THE DAY. WENT CLOSER TO MET. AT OTHER TIMES USED A BLEND.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 333 AM EST MON DEC 9 2013
MODEL ENSEMBLES INDICATE HIGH PRESSURE WILL BE ACROSS THE OHIO
VALLEY THURSDAY WHICH WILL MOVE ON TO THE EAST FRIDAY. A RETURN
FLOW ON THE BACK SIDE OF THE HIGH WILL BRING A SLIGHT MODERATION OF
TEMPERATURES BY FRIDAY. OVERALL ONLY MADE A FEW TWEAKS TO ALL BLEND
TEMPERATURES THURSDAY AND FRIDAY.
MODELS INDICATE A COUPLE OF UPPER DISTURBANCES IN THE SOUTHERN
STREAM WILL AFFECT OUR WEATHER FRIDAY NIGHT AND SATURDAY WITH LOW
PRESSURE DEVELOPING OVER TENNESSEE AND TRACKING TOWARDS THE CENTRAL
APPALACHIANS BY SATURDAY EVENING. MODELS HAVE ALSO TRENDED A LITTLE
WETTER FOR FRIDAY NIGHT AND SATURDAY. 1000-700 MB THICKNESS FAVOR
SNOW OVER THE NORTHERN HALF TO TWO THIRDS OF OUR REGION AND A WINTRY
MIX TO THE SOUTH. THIS SHOULD MOVE OUT SATURDAY NIGHT...BUT SOME
MODELS INDICATE TRACE PRECIP AMOUNTS MAY LINGER INTO SATURDAY
NIGHT...SO WILL ADD 20 PERCENT POPS MOST AREAS. THE GFS REMAINS DRY
ON SUNDAY WHILE THE EURO INDICATES POSSIBLE SNOW SHOWERS SOME AREAS
WITH A STRONGER UPPER LOW MOVING INTO THE GREAT LAKES. WITH POOR
AGREEMENT BETWEEN MODELS WILL KEEP EVERYTHING DRY FOR NOW ON SUNDAY.
IN REGARDS TO TEMPERATURES OVER THE WEEKEND...WENT A LITTLE ABOVE
ALL BLEND TEMPERATURES FRIDAY AND SATURDAY NIGHT DUE TO LOTS OF
CLOUDS AND A LITTLE COLDER SUNDAY TO PARTIALLY MATCH THE COLDER
TREND OF THE NEW EURO. IN MOST CASES THESE WERE ONLY MINOR TWEAK TO
ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 091500Z TAF UPDATE/...
ISSUED AT 921 AM EDT MON DEC 9 2013
CURRENT KIND RADAR SHOWING VERY LIGHT RETURNS WITH A FEW STATIONS
REPORTING FLURRIES. RAP SOUNDINGS INDICATING VERY WEAK INSTABILITY
UNDERNEATH THE INVERSION WHICH IS LIKELY CONTRIBUTING TO THE
FLURRIES. WILL INTRODUCE AT ALL SITES THROUGH 17Z BUT EXPECT NO
VISIBILITY RESTRICTIONS. OTHER CHANGE WAS TO INTRODUCE GUSTS THROUGH
THE AFTERNOON.
12Z DISCUSSION FOLLOWS...
ISSUED AT 605 AM EDT MON DEC 9 2013
MVFR CEILINGS WITH IFR CEILINGS POSSIBLE AT TIMES EARLY THIS MORNING
WILL IMPROVE TO VFR BY LATE AFTERNOON. THEN SOME AREAS MAY BECOME
MVFR CEILINGS SNOW LATE TONIGHT.
LOW PRESSURE OVER THE GREAT LAKES WILL CONTINUE MOVING NORTHEAST AS
HIGH PRESSURE OVER THE CENTRAL PLAINS BUILDS SLOWLY EASTWARD.
LOOK FOR A GRADUAL IMPROVEMENT IN THE CEILINGS BUT REMAINING MVFR
CEILINGS THROUGH MID AFTERNOON. AFTER THAT CEILINGS WILL RISE TO 3
THOUSAND AND LOWER CLOUDS MAY SCATTER OUT TOWARDS EVENING. A
WEATHER DISTURBANCE WILL TRACK INTO THE OHIO VALLEY LATE TONIGHT
BRINGING AN AREA OF SNOW OVER CENTRAL AND SOUTHERN SECTIONS. THIS
MAY RESULT IN MVFR OR POSSIBLY IFR CEILINGS AND SNOW SOME AREAS FROM
INDY AND SOUTHWARD LATE TONIGHT.
WINDS WILL BE FROM THE WEST UP TO 12 KNOTS TODAY AND 8 KNOTS OR LESS
TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...TUCEK
SHORT TERM...50
LONG TERM....JH
AVIATION...JH/RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
921 AM EST MON DEC 9 2013
.UPDATE...
AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 AM EST MON DEC 9 2013
HIGH PRESSURE WILL BRIEFLY MOVE INTO THE AREA TODAY BUT ANOTHER
UPPER DISTURBANCE WILL PROVIDE A CHANCE FOR SNOW FOR PARTS OF
CENTRAL INDIANA TONIGHT AND EARLY TUESDAY. AN AREA OF LOW PRESSURE
WILL THEN BRING A SMALL CHANCE FOR SNOW TO OTHER PARTS OF THE AREA
WEDNESDAY. COLDER AIR WILL THEN FLOW IN FOR THURSDAY.
TEMPERATURES WILL MODERATE BY THE WEEKEND BUT YET ANOTHER SYSTEM
WILL BRING CHANCES FOR PRECIPITATION FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /TODAY/...
ISSUED AT 337 AM EST MON DEC 9 2013
A BAND OF LIGHT SNOW HAS DEVELOPED ALONG A WEAK SURFACE TROUGH
MOVING ACROSS CENTRAL INDIANA. THIS BAND OF SNOW WILL BE OUT OF MUCH
OF THE FORECAST AREA SHORTLY. BEHIND THE SNOW VISIBILITIES GENERALLY
IMPROVE WITH NO MENTION OF FREEZING DRIZZLE SEEN IN OBSERVATIONS.
BASED ON THIS HAVE DECIDED TO END WINTER WEATHER ADVISORY AT
ISSUANCE TIME. WILL CONTINUE WITH A SPECIAL WEATHER STATEMENT THOUGH
MENTIONING SLICK CONDITIONS PERSISTING EVEN THOUGH FREEZING
PRECIPITATION HAS ENDED. WILL KEEP FLURRIES IN THE GRIDS THROUGH 12Z.
OTHERWISE EXPECT A LITTLE DECREASE IN CLOUDS DURING THE DAY...BUT
STILL MOSTLY CLOUDY OVERALL. TEMPERATURES WILL FALL SOME IN COLD
ADVECTION THIS MORNING AND THEN REBOUND A BIT THIS AFTERNOON. BASED
ON EXPECTED TIME OF ARRIVAL OF COLDER AIR MOS HIGHS LOOK PRETTY GOOD
FOR TODAY.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EST MON DEC 9 2013
FOCUS IS ON CHANCES FOR PRECIPITATION THROUGH THE PERIOD. MODELS ARE
IN DECENT AGREEMENT WITH THE BIG PICTURE SO USED A BLEND FOR MOST
PERIODS.
TONIGHT ISENTROPIC LIFT INCREASES ONCE AGAIN IN ADVANCE OF AN UPPER
WAVE. BEST FORCING AND MOISTURE LOOK TO BE CONFINED TO THE SOUTHERN
2/3 OF THE FORECAST AREA. THERE LOOKS TO BE SOME FRONTOGENETICAL
FORCING ACROSS MAINLY THE SOUTHERN HALF OF THE AREA AS WELL.
NAM IS FARTHEST NORTH WITH PRECIPITATION WITH OTHERS A BIT FARTHER
SOUTH. THIS LOOKS TO BE ANOTHER CASE WITH A VERY SHARP CUTOFF OF
POTENTIAL ACCUMULATING SNOW AND NO SNOW AT ALL. THUS CONFIDENCE IS
ONLY LOW TO MEDIUM IN NORTHERN PLACEMENT OF POPS...ESPECIALLY NORTH.
WILL GO DRY IN THE FAR NORTHWEST TONIGHT WITH A QUICK TRANSITION TO
HIGH CHANCE CATEGORY POPS SOUTH. IF NAM IS RIGHT WILL HAVE TO BUMP
TO LIKELY POPS ACROSS THE SOUTH WITH LATER FORECASTS. WILL CONTINUE
TO WATCH CLOSELY. POTENTIAL EXISTS FOR A QUICK INCH OR SO IN SOME
AREAS ACROSS THE SOUTH.
FORCING QUICKLY ENDS LATE TONIGHT INTO EARLY TUESDAY SO ONLY WENT
SLIGHT CHANCE POPS EARLY TUESDAY ACROSS THE FAR SOUTHEAST. OTHERWISE
CLOUDS WILL DECREASE TUESDAY AS SYSTEM EXITS. HOWEVER CLOUDS WILL
INCREASE ACROSS THE NORTH TUESDAY NIGHT AS THE NEXT SYSTEM
APPROACHES.
AN AREA OF LOW PRESSURE WILL MOVE ACROSS THE LOWER GREAT LAKES
WEDNESDAY. BEST FORCING AND MOISTURE REMAIN NORTH OF THE FORECAST
AREA...BUT LOOKS LIKE JUST ENOUGH MIGHT SNEAK INTO THE FAR NORTHERN
FORECAST AREA TO GO SLIGHT CHANCE POPS. DRY CONDITIONS WILL PREVAIL
WEDNESDAY NIGHT AS SYSTEM EXITS.
LOOKING AT TEMPERATURES...MAV LOOKS TOO COLD TONIGHT GIVEN EXPECTED
CLOUD COVER WITH NEXT SYSTEM. WENT CLOSER TO WARMER MET. ON TUESDAY
MAV LOOKS TOO WARM MANY AREAS GIVEN SOME COLD ADVECTION DURING PART
OF THE DAY. WENT CLOSER TO MET. AT OTHER TIMES USED A BLEND.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 333 AM EST MON DEC 9 2013
MODEL ENSEMBLES INDICATE HIGH PRESSURE WILL BE ACROSS THE OHIO
VALLEY THURSDAY WHICH WILL MOVE ON TO THE EAST FRIDAY. A RETURN
FLOW ON THE BACK SIDE OF THE HIGH WILL BRING A SLIGHT MODERATION OF
TEMPERATURES BY FRIDAY. OVERALL ONLY MADE A FEW TWEAKS TO ALL BLEND
TEMPERATURES THURSDAY AND FRIDAY.
MODELS INDICATE A COUPLE OF UPPER DISTURBANCES IN THE SOUTHERN
STREAM WILL AFFECT OUR WEATHER FRIDAY NIGHT AND SATURDAY WITH LOW
PRESSURE DEVELOPING OVER TENNESSEE AND TRACKING TOWARDS THE CENTRAL
APPALACHIANS BY SATURDAY EVENING. MODELS HAVE ALSO TRENDED A LITTLE
WETTER FOR FRIDAY NIGHT AND SATURDAY. 1000-700 MB THICKNESS FAVOR
SNOW OVER THE NORTHERN HALF TO TWO THIRDS OF OUR REGION AND A WINTRY
MIX TO THE SOUTH. THIS SHOULD MOVE OUT SATURDAY NIGHT...BUT SOME
MODELS INDICATE TRACE PRECIP AMOUNTS MAY LINGER INTO SATURDAY
NIGHT...SO WILL ADD 20 PERCENT POPS MOST AREAS. THE GFS REMAINS DRY
ON SUNDAY WHILE THE EURO INDICATES POSSIBLE SNOW SHOWERS SOME AREAS
WITH A STRONGER UPPER LOW MOVING INTO THE GREAT LAKES. WITH POOR
AGREEMENT BETWEEN MODELS WILL KEEP EVERYTHING DRY FOR NOW ON SUNDAY.
IN REGARDS TO TEMPERATURES OVER THE WEEKEND...WENT A LITTLE ABOVE
ALL BLEND TEMPERATURES FRIDAY AND SATURDAY NIGHT DUE TO LOTS OF
CLOUDS AND A LITTLE COLDER SUNDAY TO PARTIALLY MATCH THE COLDER
TREND OF THE NEW EURO. IN MOST CASES THESE WERE ONLY MINOR TWEAK TO
ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR THE 091500Z TAF UPDATE/...
ISSUED AT 921 AM EDT MON DEC 9 2013
CURRENT KIND RADAR SHOWING VERY LIGHT RETURNS WITH A FEW STATIONS
REPORTING FLURRIES. RAP SOUNDINGS INDICATING VERY WEAK INSTABILITY
UNDERNEATH THE INVERSION WHICH IS LIKELY CONTRIBUTING TO THE
FLURRIES. WILL INTRODUCE AT ALL SITES THROUGH 17Z BUT EXPECT NO
VISIBILITY RESTRICTIONS. OTHER CHANGE WAS TO INTRODUCE GUSTS THROUGH
THE AFTERNOON.
12Z DISCUSSION FOLLOWS.
MVFR CEILINGS WITH IFR CEILINGS POSSIBLE AT TIMES EARLY THIS MORNING
WILL IMPROVE TO VFR BY LATE AFTERNOON. THEN SOME AREAS MAY BECOME
MVFR CEILINGS SNOW LATE TONIGHT.
LOW PRESSURE OVER THE GREAT LAKES WILL CONTINUE MOVING NORTHEAST AS
HIGH PRESSURE OVER THE CENTRAL PLAINS BUILDS SLOWLY EASTWARD.
LOOK FOR A GRADUAL IMPROVEMENT IN THE CEILINGS BUT REMAINING MVFR
CEILINGS THROUGH MID AFTERNOON. AFTER THAT CEILINGS WILL RISE TO 3
THOUSAND AND LOWER CLOUDS MAY SCATTER OUT TOWARDS EVENING. A
WEATHER DISTURBANCE WILL TRACK INTO THE OHIO VALLEY LATE TONIGHT
BRINGING AN AREA OF SNOW OVER CENTRAL AND SOUTHERN SECTIONS. THIS
MAY RESULT IN MVFR OR POSSIBLY IFR CEILINGS AND SNOW SOME AREAS FROM
INDY AND SOUTHWARD LATE TONIGHT.
WINDS WILL BE FROM THE WEST UP TO 12 KNOTS TODAY AND 8 KNOTS OR LESS
TONIGHT.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...50
SHORT TERM...50
LONG TERM....JH
AVIATION...JH/RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
749 AM EST MON DEC 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 551 AM EST MON DEC 9 2013
WV IMAGERY AND RUC ANALYSIS STILL SHOWING A BROAD MID/UPPER LEVEL
TROUGH OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO
THE GREAT LAKES. THERE ARE SEVERAL SHORTWAVES OF NOTE FOR THE SHORT
TERM.
ONE SHORTWAVE MOVING ACROSS LAKE MI INTO LOWER MI AND ITS
ASSOC SFC LOW PRODUCED LIGHT SNOW ACROSS THE CWA LAST NIGHT INTO THE
EARLY MORNING. MOST OF THE AREA RECEIVED GENERALLY NO MORE THAN AN
INCH OF SYSTEM SNOW...ALTHOUGH SOME LOCATIONS ALONG LAKE MI LIKELY
RECEIVED 2 TO LOCALLY 4 INCHES OF SNOW DUE TO LAKE ENHANCEMENT OF
SNOW OFF LAKE MI. MQT RADAR WAS SHOWING A MORE PROMINENT BAND OF
LAKE ENHANCED SNOW FROM NEAR COOKS/MANISTIQUE AREA NORTH TO
SHINGLETON IN THE PAST FEW HOURS ALTHOUGH IT LOOKS LIKE THIS BAND
MAY BE WEAKENING NOW AS BEST FORCING FOR ENHANCEMENT APPEARS TO BE
LIFTING EAST WITH THE SHORTWAVE. DUE TO ISOLATED NATURE OF THIS
BAND DECIDED TO ONLY KEEP WINTER WX ADVISORY GOING FOR ONLY
SCHOOLCRAFT COUNTY THRU 14Z AND DROPPED ADVISORY FOR MNM-DELTA AND
LUCE WHERE SNOW HAS BEEN VERY LIGHT AND APPEARS TO BE
DIMINISHING.
TODAY AND TONIGHT...THE MAIN SHORTWAVE OF CONCERN FOR THIS FCST PD
IS IMMEDIATELY UPSTREAM OVER THE NRN PLAINS AND WILL BE PUSHING
THROUGH THE UPPER GREAT LAKES LATE THIS MORNING AND AFTERNOON. THE
NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE WESTERN CWA
BEHIND A COLD FRONT AT THE START OF THE PERIOD. MODELS INDICATE 850
MB TEMPS FALLING TO -20 TO -23C BY THE AFTERNOON COMBINED WITH
INVERSION HEIGHTS RISING TO 8-10KFT AND UNIDIRECTIONAL WESTERLY
WINDS RESULTING IN FAVORABLE LOW LEVEL CONV AND THE LIKELYHOOD OF A
DOMINANT LES BAND IMPACTING THE KEWEENAW PENINSULA. WITH THE PASSAGE
OF THE SHRTWV...EXPECT WINDS WOULD VEER FROM WSW TO MORE DUE
W...PUSHING THE DOMINANT BAND SLOWLY TO THE SOUTH FROM NEAR EAGLE
RIVER TO CALUMET/MOHAWK AND TO HOUGHTON THIS AFTERNOON AND TO POINTS
SOUTH OF HOUGHTON THIS EVENING. SNOWFALL ACCUMULATIONS WILL GREATLY
DEPEND ON HOW LONG THE HEAVIER BAND LINGERS IN ANY ONE
LOCATION...ACCUMULATIONS OF 6-10 INCHES REMAIN VERY LIKELY LATE THIS
MORNING THROUGH TONIGHT. IN ADDITION...BLUSTERY WEST WINDS OF
20-30MPH WITH GUSTS OVER 35 MPH WILL PRODUCE CONSIDERABLE BLOWING
AND DRIFTING SNOW AND NEAR WHITEOUT CONDITIONS WHERE THE DOMINANT
BAND SETS UP. HOWEVER...SINCE MOST OF THE 00Z AND 06Z LOCAL AND
REGIONAL HIGHER RES MODELS STILL INDICATE THAT THE DOMINANT BAND
WILL BE GRADUALLY MOVING SOUTH ACROSS THE KEWEENAW PENINSULA FROM
LATE MORNING THROUGH THE AFTERNOON HRS...FELT RELUCTANT TO UPGRADE
TO A WARNING AS AMOUNTS MAY BE SOMEWHAT LIMITED DUE TO TRANSIENT
NATURE OF BAND. I AM ALSO A LITTLE CONCERNED THAT BEST ENHANCEMENT
POTENTIAL FOR DOMINANT LES BAND WILL ARRIVE AHEAD OF THE SHORTWAVE
AND JUST BEFORE WINDS BEGIN TO VEER FROM WSW TO W SO THERE IS A
CHANCE THAT THE DOMINANT BAND MAY BE STRONGEST OUT OVER THE WATER
BEFORE IT REALLY MOVES ONSHORE TO THE KEWEENAW. DUE TO ABOVE
REASONING...DECIDED TO KEEP THE ADVISORY GOING BUT KEPT IN STRONGER
WORDING OF OCCASIONAL HEAVY SNOW AND CONSIDERABLE BLOWING
SNOW/LOCALIZED WHITEOUT CONDITONS IN WSW STATEMENT UNDER THE DOMINANT
BAND...STRESSING DIFFICULT TRAVEL AT TIMES DUE TO POOR VISIBILITY AND
BLOWING/DRIFTING SNOW. SOME OF THE HIGHER RES MODELS PARTICULARLY THE
LOCAL WRF-ARW INDICATE THAT DOMINANT COULD GET PUSHED SOUTH OF
HOUGHTON FOR A TIME THIS EVENING AND PERHAPS EVEN AFFECT NE ONTONAGON
AND NRN BARAGA COUNTIES BEFORE SHIFTING BACK ACROSS THE NRN PORTION
OF KEWEENAW OVERNIGHT AS WINDS BACK WSW AGAIN IN RESPONSE TO SFC RDG
BUILDING IN FM THE WEST.
THE REST OF THE CWA WILL FEEL THE EFFECT OF THE BITTER COLD AIR
FLOODING THE REGION. MAY FLIRT WITH WIND CHILL ADVISORY CRITERIA OF
25 BLO ZERO OR COLDER TONIGHT OVER THE WEST HALF INTERIOR OF THE CWA
AS ACTUAL TEMPS PLUMMET INTO THE DOUBLE DIGITS BLO ZERO.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 519 AM EST MON DEC 9 2013
CONTINUED NW FLOW ALOFT THROUGH THE WEEK WILL BRING LAKE EFFECT SNOW
FOR W TO NW FAVORED SNOW BELTS OFF AND ON. FOR THE REST OF UPPER
MI...ONLY BRIEF ROUNDS OF LIGHT SYNOPTIC SNOWFALL ARE EXPECTED.
ARCTIC AIR WILL REMAIN ANCHORED ACROSS THE REGION WITH MULTIPLE
REINFORCING SHOTS THROUGH THIS WEEKEND.
TUESDAY...DEEP TROUGHING OVER EASTERN NORTH AMERICA WILL CONTINUE TO
SEND MULTIPLE WEAK TROUGHS THROUGH THE GREAT LAKES REGION. THE FIRST
OF THESE IS PROGGED TO IMPACT THE CWA AT THE BEGINNING OF THE
FORECAST PERIOD. MODEL AGREEMENT HAS BEEN DECENT OVER THE PAST
COUPLE OF DAYS...SO OVERALL CONFIDENCE IS GOOD. THE WEAK SHORTWAVE
TROUGH WILL TRACK EASTWARD ACROSS NORTHERN WI THROUGHOUT THE DAY
TUESDAY. BESIDE MID-LEVEL Q-VECTOR CONV WITH THE TROUGH...THERE WILL
BE LITTLE SYNOPTIC SUPPORT. THOUGH A SECONDARY SFC LOW FORMING OVER
NORTHERN LAKE MI TUESDAY AFTERNOON IN RESPONSE THE TO MID-LEVEL
TROUGH/WARMER LAKE TEMPS COULD BACK SFC WINDS TO THE SW AND BRING
SOME MINOR LAKE ENHANCEMENT TO THE FAR SE CWA...MINIMAL ADDITIONAL
ACCUMULATION IS EXPECTED. OVERALL...CANNOT FIND ANYTHING TO JUSTIFY
THIS BEING MORE THAN A DUSTING OF SNOW FOR MOST AREAS.
EXPECTED WNW LES WILL BE SLOW TO GET GOING TUESDAY AFTERNOON UNTIL
THE MAIN SFC-H8 TROUGHS PASS EARLY TUESDAY EVENING. A BRIEF BOUT OF
SNOW ALONG THESE TROUGHS WILL BE POSSIBLE...SO BROUGHT HIGHER POPS
INLAND ACROSS THE NORTHERN CWA A BIT MORE THAN PREVIOUS FORECAST.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BUMPED UP CLOUD COVER
TUESDAY NIGHT WITH LINGERING LOW-LEVEL MOISTURE AND NO REAL MEANS TO
GET RID OF IT. THIS IMPACTS LOW TEMPS...SO HAVE INCREASED THOSE A
DEGREE OR TWO. CLOUD COVER MAY CREATE SOME DISPARITY IN MIN TEMPS
ACROSS THE CWA...SO WOULD NOT BE SURPRISED IF ONLY PORTIONS OF THE
WEST HALF REACH THEIR FORECAST MIN TEMPS TO -10F.
LES PICKS UP IN INTENSITY WITH COLDER AIR CONTINUING TO ADVECT INTO
THE AREA. MODEL GUIDANCE IS PICKING UP ON CONSIDERABLE SFC
CONVERGENCE ALONG THE EASTERN SHORELINE AS THE DEPARTING SFC TROUGH
HOLDS ON OVER WARMER LAKE WATERS. COULD SEE AN IMPRESSIVE LES BAND
IN FAR NORTHERN LUCE TO NORTHERN CHIPPEWA COUNTIES. LOCATIONS VERY
NEAR LAKE SUPERIOR EAST OF GRAND MARAIS COULD SEE IN EXCESS OF 8
INCHES...WITH SOME LOCATIONS CLOSER TO WHITEFISH POINT POSSIBLY
SURPASSING A FOOT...TUESDAY NIGHT INTO WEDNESDAY MORNING. A LOT HAS
TO BE IRONED OUT WITH BAND PLACEMENT...SO DID NOT ISSUE AN LES WATCH
ATTM.
A WEAK AND BROAD TROUGH AXIS CROSSING THE AREA WEDNESDAY WILL ONLY
ENHANCE SOME LOW-LEVEL CLOUDINESS AND ASSIST IN KEEPING TEMPS EVEN
COLDER FOR THE DAY. WITH H8 TEMPS AT -25C AND CONTINUOUS CAA
THROUGHOUT THE DAY...INTERIOR WEST LOCATIONS...ESPECIALLY ALONG THE
WI BORDER...MAY FAIL TO GET ABOVE ZERO IN THE AFTERNOON. THE SFC
WIND FIELD BECOMES A BIT MUDDLED WEDNESDAY NIGHT AS A WEAK SFC LOW
TRACKS SE ACROSS IA...BUT A WEAK SFC RIDGE SHOULD KEEP WINDS LIGHT
AND ALLOW TEMPS TO PLUMMET ACROSS THE CWA. DID BUMP TEMPS BACK UP A
COUPLE DEGREES THOUGH AS MID-LEVEL CLOUDINESS MAY BE ON THE RISE
LATE IN THE NIGHT WITH THE APPROACH OF AN UPPER JET AND SUBTLE
MID-LEVEL TROUGH. WITH THAT SAID...SOME OF THE COLDEST LOCATIONS
ACROSS THE CENTRAL CWA COULD SEE TEMPS FALL AS LOW AS -20F. THOUGH
WINDS WILL BE LIGHT...WIND CHILLS WILL STILL DROP AS LOW AS -35F FOR
THE COLDEST LOCATIONS.
THURSDAY THROUGH SUNDAY...DID NOT FOCUS HEAVILY ON THIS PERIOD GIVEN
SOME MODEL DISAGREEMENT. USED THE ECMWF HEAVILY AS THE GFS HAS
DEVELOPED SOME CONTINUITY ISSUES OVER THE PAST FEW RUNS. OVERALL
PATTERN BEGINS TO CHANGE SOMEWHAT...THOUGH TEMPS WILL REMAIN WELL
BELOW NORMAL. A WEAK CLIPPER SYSTEM LOOKS TO BRING ANOTHER ROUND OF
VERY LIGHT SNOW THURSDAY...BUT ONCE AGAIN...OVERALL SUPPORT IS
MINIMAL. AN ASSOCIATED SFC TROUGH WILL LAY OUT ACROSS THE UPPER MS
VALLEY THROUGH FRIDAY. COMBINED WITH THE RIGHT ENTRANCE OF THE
PASSING UPPER JET...SOME MINOR SYNOPTIC SNOW IS POSSIBLE
FRIDAY...BUT DID NOT PLACE MORE THAN SLIGHT CHANCE POPS AWAY FROM
LAKE SUPERIOR. PLENTY OF CLOUD COVERED AND CONTINUED LES FOR NW SNOW
BELTS SHOULD LAST INTO SATURDAY...BUT MUCH LOWER INVERSION HEIGHTS
WILL LIKELY PREVENT ANY SIGNIFICANT ACCUMULATIONS. WHAT WAS STARTING
TO LOOK LIKE A WARMING TREND THROUGH THE WEEKEND MAY BE HALTED BY
YET ANOTHER CLIPPER SYSTEM TRACKING SE ACROSS THE AREA ON SUNDAY.
COLDER AIR WILL WRAP AROUND THIS AND KEEP TEMPS DOWN INTO EARLY NEXT
WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 738 AM EST MON DEC 9 2013
KIWD...EXPECT MVFR CIGS AND -SN IN WSW FLOW THROUGH MUCH OF THE DAY.
CONDITIONS SHOULD IMPROVE TO VFR THIS EVENING AS WINDS BACK MORE SW.
MVFR CONDITIONS IN LIGHT SNOW RETURN LATE TONIGHT WITH APPROACH OF
NEXT SYSTEM FROM THE NOTRHERN PLAINS.
KCMX...MVFR CONDITIONS WILL LOWER TO LIFR/VLIFR VSBY IN MODERATE TO
HEAVY LAKE EFFECT SNOW BY MID MORNING AS WINDS VEER TO THE WEST AND
BECOME GUSTY AND THIS WILL CONTINUE INTO THE EVENING HRS. CONDITIONS
WILL IMPROVE AGAIN TO MVFR LATE TONIGHT AS LES BAND SHIFT OF THE
AREA.
KSAW...EXPECT VFR CONDITIONS THROUGH MUCH OF THE PD IN W-SW FLOW. WSW
WINDS WILL LIKELY GUST OVER 20KT FOR A PERIOD THIS AFTERNOON.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 551 AM EST MON DEC 9 2013(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES FOR GALES. THE FIRST TROUGH WILL
PASS ACROSS LAKE SUPERIOR LATE THIS MORNING/AFTERNOON VEERING WINDS
TO THE WEST AND INCREASING THEM TO GALES TO 35 TO 40 KNOTS ACROSS
LAKE SUPERIOR THIS AFTERNOON AND EVENING. AFTER A DECREASE TO 20 TO
30 KNOT SOUTHWEST WINDS TUESDAY MORNING...ANOTHER LOW PRESSURE WILL
TRACK EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND COULD PRODUCE
GALE FORCE WIND GUSTS TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON AND
EVENING. THE WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30 KNOTS
FROM LATE TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE EXTENDING FROM
HIGH PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS INTO THE AREA.
CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE POSSIBLE
THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR ACROSS THE
LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE SOUTHEASTWARD
ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WINDS SHOULD
REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MIZ014-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
TUESDAY FOR LSZ245-248>251-265>267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 5 AM EST TUESDAY FOR
LSZ244-245-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM EST /NOON CST/ THIS
AFTERNOON TO 7 AM EST /6 AM CST/ TUESDAY FOR LSZ162-240>244-
263-264.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 5 AM EST TUESDAY FOR
LSZ264.
GALE WARNING FROM 1 PM EST /NOON CST/ THIS AFTERNOON TO 10 PM
EST /9 PM CST/ THIS EVENING FOR LSZ241>243-246-247.
GALE WARNING FROM 1 PM THIS AFTERNOON TO MIDNIGHT EST TONIGHT
FOR LSZ263.
LAKE MICHIGAN...
GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 PM EST THIS EVENING
FOR LMZ221-248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...KLUBER
AVIATION...VOSS
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
552 AM EST MON DEC 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 551 AM EST MON DEC 9 2013
WV IMAGERY AND RUC ANALYSIS STILL SHOWING A BROAD MID/UPPER LEVEL
TROUGH OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO
THE GREAT LAKES. THERE ARE SEVERAL SHORTWAVES OF NOTE FOR THE SHORT
TERM.
ONE SHORTWAVE MOVING ACROSS LAKE MI INTO LOWER MI AND ITS
ASSOC SFC LOW PRODUCED LIGHT SNOW ACROSS THE CWA LAST NIGHT INTO THE
EARLY MORNING. MOST OF THE AREA RECEIVED GENERALLY NO MORE THAN AN
INCH OF SYSTEM SNOW...ALTHOUGH SOME LOCATIONS ALONG LAKE MI LIKELY
RECEIVED 2 TO LOCALLY 4 INCHES OF SNOW DUE TO LAKE ENHANCEMENT OF
SNOW OFF LAKE MI. MQT RADAR WAS SHOWING A MORE PROMINENT BAND OF
LAKE ENHANCED SNOW FROM NEAR COOKS/MANISTIQUE AREA NORTH TO
SHINGLETON IN THE PAST FEW HOURS ALTHOUGH IT LOOKS LIKE THIS BAND
MAY BE WEAKENING NOW AS BEST FORCING FOR ENHANCEMENT APPEARS TO BE
LIFTING EAST WITH THE SHORTWAVE. DUE TO ISOLATED NATURE OF THIS
BAND DECIDED TO ONLY KEEP WINTER WX ADVISORY GOING FOR ONLY
SCHOOLCRAFT COUNTY THRU 14Z AND DROPPED ADVISORY FOR MNM-DELTA AND
LUCE WHERE SNOW HAS BEEN VERY LIGHT AND APPEARS TO BE
DIMINISHING.
TODAY AND TONIGHT...THE MAIN SHORTWAVE OF CONCERN FOR THIS FCST PD
IS IMMEDIATELY UPSTREAM OVER THE NRN PLAINS AND WILL BE PUSHING
THROUGH THE UPPER GREAT LAKES LATE THIS MORNING AND AFTERNOON. THE
NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE WESTERN CWA
BEHIND A COLD FRONT AT THE START OF THE PERIOD. MODELS INDICATE 850
MB TEMPS FALLING TO -20 TO -23C BY THE AFTERNOON COMBINED WITH
INVERSION HEIGHTS RISING TO 8-10KFT AND UNIDIRECTIONAL WESTERLY
WINDS RESULTING IN FAVORABLE LOW LEVEL CONV AND THE LIKELYHOOD OF A
DOMINANT LES BAND IMPACTING THE KEWEENAW PENINSULA. WITH THE PASSAGE
OF THE SHRTWV...EXPECT WINDS WOULD VEER FROM WSW TO MORE DUE
W...PUSHING THE DOMINANT BAND SLOWLY TO THE SOUTH FROM NEAR EAGLE
RIVER TO CALUMET/MOHAWK AND TO HOUGHTON THIS AFTERNOON AND TO POINTS
SOUTH OF HOUGHTON THIS EVENING. SNOWFALL ACCUMULATIONS WILL GREATLY
DEPEND ON HOW LONG THE HEAVIER BAND LINGERS IN ANY ONE
LOCATION...ACCUMULATIONS OF 6-10 INCHES REMAIN VERY LIKELY LATE THIS
MORNING THROUGH TONIGHT. IN ADDITION...BLUSTERY WEST WINDS OF
20-30MPH WITH GUSTS OVER 35 MPH WILL PRODUCE CONSIDERABLE BLOWING
AND DRIFTING SNOW AND NEAR WHITEOUT CONDITIONS WHERE THE DOMINANT
BAND SETS UP. HOWEVER...SINCE MOST OF THE 00Z AND 06Z LOCAL AND
REGIONAL HIGHER RES MODELS STILL INDICATE THAT THE DOMINANT BAND
WILL BE GRADUALLY MOVING SOUTH ACROSS THE KEWEENAW PENINSULA FROM
LATE MORNING THROUGH THE AFTERNOON HRS...FELT RELUCTANT TO UPGRADE
TO A WARNING AS AMOUNTS MAY BE SOMEWHAT LIMITED DUE TO TRANSIENT
NATURE OF BAND. I AM ALSO A LITTLE CONCERNED THAT BEST ENHANCEMENT
POTENTIAL FOR DOMINANT LES BAND WILL ARRIVE AHEAD OF THE SHORTWAVE
AND JUST BEFORE WINDS BEGIN TO VEER FROM WSW TO W SO THERE IS A
CHANCE THAT THE DOMINANT BAND MAY BE STRONGEST OUT OVER THE WATER
BEFORE IT REALLY MOVES ONSHORE TO THE KEWEENAW. DUE TO ABOVE
REASONING...DECIDED TO KEEP THE ADVISORY GOING BUT KEPT IN STRONGER
WORDING OF OCCASIONAL HEAVY SNOW AND CONSIDERABLE BLOWING
SNOW/LOCALIZED WHITEOUT CONDITONS UNDER THE DOMINANT
BAND...STRESSING DIFFICULT TRAVEL AT TIMES DUE TO POOR VISIBILITY AND
BLOWING/DRIFTING SNOW. SOME OF THE HIGHER RES MODELS PARTICULARLY
THE LOCAL WRF-ARW INDICATE THAT DOMINANT COULD GET PUSHED SOUTH OF
HOUGHTON FOR A TIME THIS EVENING AND PERHAPS EVEN AFFECT NE
ONTONAGON AND NRN BARAGA COUNTIES BEFORE SHIFTING BACK ACROSS THE
NRN PORTION OF KEWEENAW OVERNIGHT AS WINDS BACK WSW AGAIN IN
RESPONSE TO SFC RDG BUILDING IN FM THE WEST.
THE REST OF THE CWA WILL FEEL THE EFFECT OF THE BITTER COLD AIR
FLOODING THE REGION. MAY FLIRT WITH WIND CHILL ADVISORY CRITERIA OF
25 BLO ZERO OR COLDER TONIGHT OVER THE WEST HALF INTERIOR OF THE CWA
AS ACTUAL TEMPS PLUMMET INTO THE DOUBLE DIGITS BLO ZERO.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 519 AM EST MON DEC 9 2013
CONTINUED NW FLOW ALOFT THROUGH THE WEEK WILL BRING LAKE EFFECT SNOW
FOR W TO NW FAVORED SNOW BELTS OFF AND ON. FOR THE REST OF UPPER
MI...ONLY BRIEF ROUNDS OF LIGHT SYNOPTIC SNOWFALL ARE EXPECTED.
ARCTIC AIR WILL REMAIN ANCHORED ACROSS THE REGION WITH MULTIPLE
REINFORCING SHOTS THROUGH THIS WEEKEND.
TUESDAY...DEEP TROUGHING OVER EASTERN NORTH AMERICA WILL CONTINUE TO
SEND MULTIPLE WEAK TROUGHS THROUGH THE GREAT LAKES REGION. THE FIRST
OF THESE IS PROGGED TO IMPACT THE CWA AT THE BEGINNING OF THE
FORECAST PERIOD. MODEL AGREEMENT HAS BEEN DECENT OVER THE PAST
COUPLE OF DAYS...SO OVERALL CONFIDENCE IS GOOD. THE WEAK SHORTWAVE
TROUGH WILL TRACK EASTWARD ACROSS NORTHERN WI THROUGHOUT THE DAY
TUESDAY. BESIDE MID-LEVEL Q-VECTOR CONV WITH THE TROUGH...THERE WILL
BE LITTLE SYNOPTIC SUPPORT. THOUGH A SECONDARY SFC LOW FORMING OVER
NORTHERN LAKE MI TUESDAY AFTERNOON IN RESPONSE THE TO MID-LEVEL
TROUGH/WARMER LAKE TEMPS COULD BACK SFC WINDS TO THE SW AND BRING
SOME MINOR LAKE ENHANCEMENT TO THE FAR SE CWA...MINIMAL ADDITIONAL
ACCUMULATION IS EXPECTED. OVERALL...CANNOT FIND ANYTHING TO JUSTIFY
THIS BEING MORE THAN A DUSTING OF SNOW FOR MOST AREAS.
EXPECTED WNW LES WILL BE SLOW TO GET GOING TUESDAY AFTERNOON UNTIL
THE MAIN SFC-H8 TROUGHS PASS EARLY TUESDAY EVENING. A BRIEF BOUT OF
SNOW ALONG THESE TROUGHS WILL BE POSSIBLE...SO BROUGHT HIGHER POPS
INLAND ACROSS THE NORTHERN CWA A BIT MORE THAN PREVIOUS FORECAST.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BUMPED UP CLOUD COVER
TUESDAY NIGHT WITH LINGERING LOW-LEVEL MOISTURE AND NO REAL MEANS TO
GET RID OF IT. THIS IMPACTS LOW TEMPS...SO HAVE INCREASED THOSE A
DEGREE OR TWO. CLOUD COVER MAY CREATE SOME DISPARITY IN MIN TEMPS
ACROSS THE CWA...SO WOULD NOT BE SURPRISED IF ONLY PORTIONS OF THE
WEST HALF REACH THEIR FORECAST MIN TEMPS TO -10F.
LES PICKS UP IN INTENSITY WITH COLDER AIR CONTINUING TO ADVECT INTO
THE AREA. MODEL GUIDANCE IS PICKING UP ON CONSIDERABLE SFC
CONVERGENCE ALONG THE EASTERN SHORELINE AS THE DEPARTING SFC TROUGH
HOLDS ON OVER WARMER LAKE WATERS. COULD SEE AN IMPRESSIVE LES BAND
IN FAR NORTHERN LUCE TO NORTHERN CHIPPEWA COUNTIES. LOCATIONS VERY
NEAR LAKE SUPERIOR EAST OF GRAND MARAIS COULD SEE IN EXCESS OF 8
INCHES...WITH SOME LOCATIONS CLOSER TO WHITEFISH POINT POSSIBLY
SURPASSING A FOOT...TUESDAY NIGHT INTO WEDNESDAY MORNING. A LOT HAS
TO BE IRONED OUT WITH BAND PLACEMENT...SO DID NOT ISSUE AN LES WATCH
ATTM.
A WEAK AND BROAD TROUGH AXIS CROSSING THE AREA WEDNESDAY WILL ONLY
ENHANCE SOME LOW-LEVEL CLOUDINESS AND ASSIST IN KEEPING TEMPS EVEN
COLDER FOR THE DAY. WITH H8 TEMPS AT -25C AND CONTINUOUS CAA
THROUGHOUT THE DAY...INTERIOR WEST LOCATIONS...ESPECIALLY ALONG THE
WI BORDER...MAY FAIL TO GET ABOVE ZERO IN THE AFTERNOON. THE SFC
WIND FIELD BECOMES A BIT MUDDLED WEDNESDAY NIGHT AS A WEAK SFC LOW
TRACKS SE ACROSS IA...BUT A WEAK SFC RIDGE SHOULD KEEP WINDS LIGHT
AND ALLOW TEMPS TO PLUMMET ACROSS THE CWA. DID BUMP TEMPS BACK UP A
COUPLE DEGREES THOUGH AS MID-LEVEL CLOUDINESS MAY BE ON THE RISE
LATE IN THE NIGHT WITH THE APPROACH OF AN UPPER JET AND SUBTLE
MID-LEVEL TROUGH. WITH THAT SAID...SOME OF THE COLDEST LOCATIONS
ACROSS THE CENTRAL CWA COULD SEE TEMPS FALL AS LOW AS -20F. THOUGH
WINDS WILL BE LIGHT...WIND CHILLS WILL STILL DROP AS LOW AS -35F FOR
THE COLDEST LOCATIONS.
THURSDAY THROUGH SUNDAY...DID NOT FOCUS HEAVILY ON THIS PERIOD GIVEN
SOME MODEL DISAGREEMENT. USED THE ECMWF HEAVILY AS THE GFS HAS
DEVELOPED SOME CONTINUITY ISSUES OVER THE PAST FEW RUNS. OVERALL
PATTERN BEGINS TO CHANGE SOMEWHAT...THOUGH TEMPS WILL REMAIN WELL
BELOW NORMAL. A WEAK CLIPPER SYSTEM LOOKS TO BRING ANOTHER ROUND OF
VERY LIGHT SNOW THURSDAY...BUT ONCE AGAIN...OVERALL SUPPORT IS
MINIMAL. AN ASSOCIATED SFC TROUGH WILL LAY OUT ACROSS THE UPPER MS
VALLEY THROUGH FRIDAY. COMBINED WITH THE RIGHT ENTRANCE OF THE
PASSING UPPER JET...SOME MINOR SYNOPTIC SNOW IS POSSIBLE
FRIDAY...BUT DID NOT PLACE MORE THAN SLIGHT CHANCE POPS AWAY FROM
LAKE SUPERIOR. PLENTY OF CLOUD COVERED AND CONTINUED LES FOR NW SNOW
BELTS SHOULD LAST INTO SATURDAY...BUT MUCH LOWER INVERSION HEIGHTS
WILL LIKELY PREVENT ANY SIGNIFICANT ACCUMULATIONS. WHAT WAS STARTING
TO LOOK LIKE A WARMING TREND THROUGH THE WEEKEND MAY BE HALTED BY
YET ANOTHER CLIPPER SYSTEM TRACKING SE ACROSS THE AREA ON SUNDAY.
COLDER AIR WILL WRAP AROUND THIS AND KEEP TEMPS DOWN INTO EARLY NEXT
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1155 PM EST SUN DEC 8 2013
WIDESPREAD LIGHT SNOW WILL CONTINUE TONIGHT WITH MVFR/IFR CONDITIONS
CONTINUING OVERNIGHT. CONDITIONS SHOULD IMPROVE TO MVFR BY LATE
TONIGHT OR MON MORNING AT IWD AND SAW. LAKE EFFECT SNOW WITH VLIFR
VSBY IS EXPECTED AT CMX BY MID MORNING AS WINDS VEER TO THE WEST AND
BECOME GUSTY AND THIS WILL CONTINUE THROUGH THE REST OF THE TAF
PERIOD.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 551 AM EST MON DEC 9 2013(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES FOR GALES. THE FIRST TROUGH WILL
PASS ACROSS LAKE SUPERIOR LATE THIS MORNING/AFTERNOON VEERING WINDS
TO THE WEST AND INCREASING THEM TO GALES TO 35 TO 40 KNOTS ACROSS
LAKE SUPERIOR THIS AFTERNOON AND EVENING. AFTER A DECREASE TO 20 TO
30 KNOT SOUTHWEST WINDS TUESDAY MORNING...ANOTHER LOW PRESSURE WILL
TRACK EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND COULD PRODUCE
GALE FORCE WIND GUSTS TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON AND
EVENING. THE WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30 KNOTS
FROM LATE TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE EXTENDING FROM
HIGH PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS INTO THE AREA.
CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE POSSIBLE
THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR ACROSS THE
LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE SOUTHEASTWARD
ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WINDS SHOULD
REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MIZ014-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
TUESDAY FOR LSZ245-248>251-265>267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 5 AM EST TUESDAY FOR
LSZ244-245-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM EST /NOON CST/ THIS
AFTERNOON TO 7 AM EST /6 AM CST/ TUESDAY FOR LSZ162-240>244-
263-264.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 5 AM EST TUESDAY FOR
LSZ264.
GALE WARNING FROM 1 PM EST /NOON CST/ THIS AFTERNOON TO 10 PM
EST /9 PM CST/ THIS EVENING FOR LSZ241>243-246-247.
GALE WARNING FROM 1 PM THIS AFTERNOON TO MIDNIGHT EST TONIGHT
FOR LSZ263.
LAKE MICHIGAN...
GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 PM EST THIS EVENING
FOR LMZ221-248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...KLUBER
AVIATION...07
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
520 AM EST MON DEC 9 2013
.SHORT TERM...(THIS EVENING THROUGH MONDAY)
ISSUED AT 400 PM EST SUN DEC 8 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD MID/UPPER LEVEL TROUGH
OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO THE
GREAT LAKES. THE MAIN UPSTREAM SHORTWAVE TROUGH WAS MOVING THROUGH
SE CO. AT THE SFC...LIGHT WINDS PREVAILED ACROSS UPPER MICHIGAN AS
ARCTIC HIGH PRES EXTENDED FROM NEW ENGLAND INTO THE NRN GREAT LAKES.
A LOW PRES TROUGH STRETCHED FROM SW KS THROUGH THE OH VALLEY. A
BROAD AREA OF LIGHT SNOW SUPPORTED BY WAA/280K-290K ISENTROPIC
LIFT...HAD SPREAD FROM MN/IA/WI INTO UPPER MI. HOWEVER...SNOW HAS
BEEN VERY LIGHT WITH VSBY TO 2-4SM FROM MNM-ESC AND ABOVE 5SM FROM
IMT-IWD.
LATE THIS AFTERNOON AND TONIGHT...AS THE SHORTWAVE CONTINUES TO LIFT
TOWARD THE GREAT LAKES EXPECT THE SNOW INTENSITY TO SLOWLY INCREASE.
HOWEVER...WITH THE STRONGER 700-300 MB QVECTOR CONV REMAINING SOUTH
OF THE AREA AND ONLY 1-2 G/KG AVAILABLE...GOING QPF VALUES IN THE
0.08-0.20 RANGE REMAIN ON TRACK. EXPECT SLR VALUES FROM NEAR 20/1
SOUTH TO 15/1 NORTH AS THE DGZ IS DEEPER AND EXTENDS MORE FAVORABLY
INTO THE LAYER OF GREATER UPWARD MOTION OVER THE SOUTH COMPARED TO
THE SHALLOW DGZ FARTHER NORTH IN THE COLDER AIR.
SO...FCST SNOWFALL AMOUNTS OF AROUND AN INCH NORTH TO 1 TO 3 INCHES
SOUTH ARE INCLUDED. THE HIGHER RES MODELS SUGGEST THAT AN AREA OF
LOW LEVEL CONV OVER NRN LAKE MI AHEAD OF THE AREA OF STRONGER SE
WINDS MAY PUSH A BAND OF LAKE ENHANCED SNOW INTO LOCATIONS BORDER
THE BAY OF GREEN BAY AND LAKE MICHIGAN LATE THIS EVENING. SINCE THE
BAND IS EXPECTED TO BE TRANSIENT...ADDITIONAL SNOW AMOUNTS OF ONLY
AN INCH OR TWO ARE EXPECTED WITH THIS FEATURE. A PERIOD OF SRLY
WINDS INTO SCHOOLCRAFT COUNTY COULD ALSO BRING A PERIOD OF MODERATE
SNOW LATE TONIGHT.
MONDAY...THE FIRST OF SEVERAL EMBEDDED SHORTWAVE TROUGHS WITHIN THE
DEEP EASTERN CANADIAN TROUGH WILL BE PUSHING THROUGH THE AREA MONDAY
MORNING. THE NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE
WESTERN CWA BEHIND A COLD FRONT AT THE START OF THE PERIOD. 850 MB
TEMPS FALLING TO -21 TO -23C BY THE AFTERNOON COMBINED WITH
INVERSION HEIGHTS RISING TO 8K-10K FT AND UNIDIRECTIONAL WESTERLY
WINDS SHOULD RESULT IN FAVORABLE LOW LEVEL CONV AND POTENTIAL FOR A
DOMINANT LES BAND INTO THE NRN KEWEENAW PENINSULA. WITH THE PASSAGE
OF THE SHRTWV...EXPECT THAT THE WINDS WOULD EVENTUALLY
VEER...PUSHING THE BAND SLOWLY TO THE SOUTH FROM NEAR EAGLE RIVER TO
CALUMET/MOHAWK AND TO HOUGHTON IN THE AFTERNOON. SNOWFALL
ACCUMULATIONS WILL GREATLY DEPEND ON HOW THE HEAVIER BAND LINGERS IN
ANY ONE LOCATION...BUT 12 HOUR ACCUMULATIONS OF AT LEAST 8 INCHES
REMAIN POSSIBLE. IN ADDITION...BLUSTERY WEST WINDS OF 20-30MPH WITH
GUSTS OVER 35 MPH WILL PRODUCE CONSIDERABLE BLOWING AND DRIFTING
SNOW AND VERY LOW VSBY. HOWEVER...SINCE THE HIGHER RES MODELS STILL
SHOW DIFFERENCES IN HANDLING WHERE THE BAND WILL DEVELOP AND HOW
LONG IT WILL LINGER...THE WATCH WAS NOT UPGRADED AT THIS TIME.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 519 AM EST MON DEC 9 2013
CONTINUED NW FLOW ALOFT THROUGH THE WEEK WILL BRING LAKE EFFECT SNOW
FOR W TO NW FAVORED SNOW BELTS OFF AND ON. FOR THE REST OF UPPER
MI...ONLY BRIEF ROUNDS OF LIGHT SYNOPTIC SNOWFALL ARE EXPECTED.
ARCTIC AIR WILL REMAIN ANCHORED ACROSS THE REGION WITH MULTIPLE
REINFORCING SHOTS THROUGH THIS WEEKEND.
TUESDAY...DEEP TROUGHING OVER EASTERN NORTH AMERICA WILL CONTINUE TO
SEND MULTIPLE WEAK TROUGHS THROUGH THE GREAT LAKES REGION. THE FIRST
OF THESE IS PROGGED TO IMPACT THE CWA AT THE BEGINNING OF THE
FORECAST PERIOD. MODEL AGREEMENT HAS BEEN DECENT OVER THE PAST
COUPLE OF DAYS...SO OVERALL CONFIDENCE IS GOOD. THE WEAK SHORTWAVE
TROUGH WILL TRACK EASTWARD ACROSS NORTHERN WI THROUGHOUT THE DAY
TUESDAY. BESIDE MID-LEVEL Q-VECTOR CONV WITH THE TROUGH...THERE WILL
BE LITTLE SYNOPTIC SUPPORT. THOUGH A SECONDARY SFC LOW FORMING OVER
NORTHERN LAKE MI TUESDAY AFTERNOON IN RESPONSE THE TO MID-LEVEL
TROUGH/WARMER LAKE TEMPS COULD BACK SFC WINDS TO THE SW AND BRING
SOME MINOR LAKE ENHANCEMENT TO THE FAR SE CWA...MINIMAL ADDITIONAL
ACCUMULATION IS EXPECTED. OVERALL...CANNOT FIND ANYTHING TO JUSTIFY
THIS BEING MORE THAN A DUSTING OF SNOW FOR MOST AREAS.
EXPECTED WNW LES WILL BE SLOW TO GET GOING TUESDAY AFTERNOON UNTIL
THE MAIN SFC-H8 TROUGHS PASS EARLY TUESDAY EVENING. A BRIEF BOUT OF
SNOW ALONG THESE TROUGHS WILL BE POSSIBLE...SO BROUGHT HIGHER POPS
INLAND ACROSS THE NORTHERN CWA A BIT MORE THAN PREVIOUS FORECAST.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BUMPED UP CLOUD COVER
TUESDAY NIGHT WITH LINGERING LOW-LEVEL MOISTURE AND NO REAL MEANS TO
GET RID OF IT. THIS IMPACTS LOW TEMPS...SO HAVE INCREASED THOSE A
DEGREE OR TWO. CLOUD COVER MAY CREATE SOME DISPARITY IN MIN TEMPS
ACROSS THE CWA...SO WOULD NOT BE SURPRISED IF ONLY PORTIONS OF THE
WEST HALF REACH THEIR FORECAST MIN TEMPS TO -10F.
LES PICKS UP IN INTENSITY WITH COLDER AIR CONTINUING TO ADVECT INTO
THE AREA. MODEL GUIDANCE IS PICKING UP ON CONSIDERABLE SFC
CONVERGENCE ALONG THE EASTERN SHORELINE AS THE DEPARTING SFC TROUGH
HOLDS ON OVER WARMER LAKE WATERS. COULD SEE AN IMPRESSIVE LES BAND
IN FAR NORTHERN LUCE TO NORTHERN CHIPPEWA COUNTIES. LOCATIONS VERY
NEAR LAKE SUPERIOR EAST OF GRAND MARAIS COULD SEE IN EXCESS OF 8
INCHES...WITH SOME LOCATIONS CLOSER TO WHITEFISH POINT POSSIBLY
SURPASSING A FOOT...TUESDAY NIGHT INTO WEDNESDAY MORNING. A LOT HAS
TO BE IRONED OUT WITH BAND PLACEMENT...SO DID NOT ISSUE AN LES WATCH
ATTM.
A WEAK AND BROAD TROUGH AXIS CROSSING THE AREA WEDNESDAY WILL ONLY
ENHANCE SOME LOW-LEVEL CLOUDINESS AND ASSIST IN KEEPING TEMPS EVEN
COLDER FOR THE DAY. WITH H8 TEMPS AT -25C AND CONTINUOUS CAA
THROUGHOUT THE DAY...INTERIOR WEST LOCATIONS...ESPECIALLY ALONG THE
WI BORDER...MAY FAIL TO GET ABOVE ZERO IN THE AFTERNOON. THE SFC
WIND FIELD BECOMES A BIT MUDDLED WEDNESDAY NIGHT AS A WEAK SFC LOW
TRACKS SE ACROSS IA...BUT A WEAK SFC RIDGE SHOULD KEEP WINDS LIGHT
AND ALLOW TEMPS TO PLUMMET ACROSS THE CWA. DID BUMP TEMPS BACK UP A
COUPLE DEGREES THOUGH AS MID-LEVEL CLOUDINESS MAY BE ON THE RISE
LATE IN THE NIGHT WITH THE APPROACH OF AN UPPER JET AND SUBTLE
MID-LEVEL TROUGH. WITH THAT SAID...SOME OF THE COLDEST LOCATIONS
ACROSS THE CENTRAL CWA COULD SEE TEMPS FALL AS LOW AS -20F. THOUGH
WINDS WILL BE LIGHT...WIND CHILLS WILL STILL DROP AS LOW AS -35F FOR
THE COLDEST LOCATIONS.
THURSDAY THROUGH SUNDAY...DID NOT FOCUS HEAVILY ON THIS PERIOD GIVEN
SOME MODEL DISAGREEMENT. USED THE ECMWF HEAVILY AS THE GFS HAS
DEVELOPED SOME CONTINUITY ISSUES OVER THE PAST FEW RUNS. OVERALL
PATTERN BEGINS TO CHANGE SOMEWHAT...THOUGH TEMPS WILL REMAIN WELL
BELOW NORMAL. A WEAK CLIPPER SYSTEM LOOKS TO BRING ANOTHER ROUND OF
VERY LIGHT SNOW THURSDAY...BUT ONCE AGAIN...OVERALL SUPPORT IS
MINIMAL. AN ASSOCIATED SFC TROUGH WILL LAY OUT ACROSS THE UPPER MS
VALLEY THROUGH FRIDAY. COMBINED WITH THE RIGHT ENTRANCE OF THE
PASSING UPPER JET...SOME MINOR SYNOPTIC SNOW IS POSSIBLE
FRIDAY...BUT DID NOT PLACE MORE THAN SLIGHT CHANCE POPS AWAY FROM
LAKE SUPERIOR. PLENTY OF CLOUD COVERED AND CONTINUED LES FOR NW SNOW
BELTS SHOULD LAST INTO SATURDAY...BUT MUCH LOWER INVERSION HEIGHTS
WILL LIKELY PREVENT ANY SIGNIFICANT ACCUMULATIONS. WHAT WAS STARTING
TO LOOK LIKE A WARMING TREND THROUGH THE WEEKEND MAY BE HALTED BY
YET ANOTHER CLIPPER SYSTEM TRACKING SE ACROSS THE AREA ON SUNDAY.
COLDER AIR WILL WRAP AROUND THIS AND KEEP TEMPS DOWN INTO EARLY NEXT
WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z MONDAY NIGHT)
ISSUED AT 1155 PM EST SUN DEC 8 2013
WIDESPREAD LIGHT SNOW WILL CONTINUE TONIGHT WITH MVFR/IFR CONDITIONS
CONTINUING OVERNIGHT. CONDITIONS SHOULD IMPROVE TO MVFR BY LATE
TONIGHT OR MON MORNING AT IWD AND SAW. LAKE EFFECT SNOW WITH VLIFR
VSBY IS EXPECTED AT CMX BY MID MORNING AS WINDS VEER TO THE WEST AND
BECOME GUSTY AND THIS WILL CONTINUE THROUGH THE REST OF THE TAF
PERIOD.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES OF GALES. THE FIRST WILL PASS
SOUTHEAST OF UPPER MI MONDAY MORNING. BEHIND THIS TROUGH...WINDS
WILL VEER TO THE WEST AND INCREASE TO GALES TO 35 TO 40 KNOTS ACROSS
LAKE SUPERIOR MONDAY AFTERNOON AND EVENING. AFTER A DECREASE TO 20
TO 30 KNOT SOUTHWEST WINDS TUESDAY MORNING...LOW PRESSURE WILL TRACK
EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND PRODUCE ANOTHER ROUND
OF GALES TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON AND EVENING. THE
WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30 KNOTS FROM LATE
TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE EXTENDING FROM HIGH
PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS INTO THE AREA.
CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE POSSIBLE
THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR ACROSS THE
LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE SOUTHEASTWARD
ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WINDS SHOULD
REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 9 AM EST THIS MORNING FOR MIZ014-
085.
LAKE EFFECT SNOW ADVISORY UNTIL 7 AM EST TUESDAY FOR MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
TUESDAY FOR LSZ245-248>251-265>267.
GALE WARNING FROM 1 PM THIS AFTERNOON TO 5 AM EST TUESDAY FOR
LSZ244-245-265>267.
HEAVY FREEZING SPRAY WARNING FROM 1 PM EST /NOON CST/ THIS
AFTERNOON TO 7 AM EST /6 AM CST/ TUESDAY FOR LSZ162-240>244-
263-264.
GALE WARNING FROM 4 PM THIS AFTERNOON TO 5 AM EST TUESDAY FOR
LSZ264.
GALE WARNING FROM 1 PM EST /NOON CST/ THIS AFTERNOON TO 10 PM
EST /9 PM CST/ THIS EVENING FOR LSZ241>243-246-247.
GALE WARNING FROM 1 PM THIS AFTERNOON TO MIDNIGHT EST TONIGHT
FOR LSZ263.
LAKE MICHIGAN...
GALE WARNING FROM 4 PM THIS AFTERNOON TO 10 PM EST THIS EVENING
FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...KLUBER
AVIATION...07
MARINE...JLB
AREA FORECAST DISCUSSION
NWS BILLINGS MT
331 AM MST MON DEC 9 2013
.SHORT TERM...VALID FOR TDY AND TUE...
WIND-RELATED WINTER WEATHER ISSUES TODAY WILL TRANSITION BACK TO A
HIGH PROBABILITY OF 1 TO 2 INCHES OF SNOW IN MANY AREAS TUE AS TWO
SHORT WAVES CROSS THE REGION IN STRONG NORTHWEST FLOW ALOFT. WE DO
STILL EXPECT A SLOW MODERATION IN TEMPERATURES TO CONTINUE THOUGH.
TODAY...LEE-SIDE SURFACE PRESSURE FALLS ON THE ORDER OF 5 HPA/3 HR
CENTERED ACROSS THE CENTRAL ALBERTA-SASKATCHEWAN BORDER EARLY THIS
MORNING WILL REACH NORTHEAST MT AND WESTERN ND BY MIDDAY. THE WIND
SPEEDS IN SOUTH CENTRAL MT WILL CONTINUE RAMPING UP AS THAT OCCURS
AND WILL BE BOOSTED FURTHER BY EXTRA PRESSURE GRADIENT THANKS TO A
FORMIDABLE COLD AIR MASS TRAPPED WEST OF THE LOCAL MOUNTAINS. WIND
SPEEDS IN THE GRIDDED FORECAST WERE HEAVILY WEIGHTED TO RAP OUTPUT
SINCE IT IS HANDLING EARLY-DAY WINDS NEAR BIG TIMBER /WHICH IS THE
FAVORED SPOT FOR THE HIGHEST SPEEDS IN THIS PATTERN/ WELL. WE THUS
HAVE HIGH CONFIDENCE IN SUSTAINED SPEEDS OF 40 TO 50 MPH AND GUSTS
TO 70 MPH FROM LIVINGSTON TO BIG TIMBER TODAY...AND GUSTS UP TO 55
MPH AT HARLOWTON AND 45 MPH AROUND BILLINGS TOO. THE WINDS WILL BE
ON THE INCREASE ON THE PLAINS OF SOUTH CENTRAL AND SOUTHEAST MT BY
21 UTC AS WELL AS MIXING INCREASES AND A MODEST BATCH OF LOW-LEVEL
HEIGHT RISES BEGINS AFFECTING THAT AREA...THOUGH MOMENTUM TRANSFER
WILL BE LACKING AND ONLY SUPPORTS GUSTS TO ABOUT 35 MPH ACROSS THE
SOUTHEAST PART OF MT. ADD IN SNOW SHOWERS WHICH COULD DROP A QUICK
INCH OF SNOW AND REDUCE VISIBILITY ON THEIR OWN TOO OVER SOUTHEAST
MT THOUGH...AND CONDITIONS COULD BE QUITE HAZARDOUS OVER THAT AREA
AS WELL. WE ACTUALLY PUSHED POPS FOR SNOW SHOWER ACTIVITY INTO THE
70-90 PERCENT RANGE OVER SOUTHEAST MT THIS AFTERNOON BASED ON GOOD
AGREEMENT IN 00 UTC GUIDANCE IN NOTABLE QG-FORCING OVER THAT AREA.
NEEDLESS TO SAY...BLOWING AND DRIFTING SNOW IS MENTIONED TODAY AND
INTO THIS EVENING FOR MOST OF THE AREA...THOUGH DEPTH AND PHYSICAL
CHARACTERISTICS OF THE SNOW SUGGEST THE BIGGEST ISSUE COULD END UP
BEING SIGNIFICANT DRIFTING. WE WILL NONETHELESS NEED TO BE WARY OF
THE POSSIBILITY OF BONAFIDE GROUND BLIZZARD CONDITIONS IN THE OPEN
COUNTRY WHERE LOCALLY DEEPER SNOW PACK RESIDES...THOUGH THE CHANCE
OF THAT APPEARS RELATIVELY LOW /SUBJECTIVELY NEAR 30 PERCENT/.
WHERE HEADLINES ARE CONCERNED...WE ADDED ALL OF BIG HORN COUNTY TO
A WINTER WEATHER ADVISORY FROM 18 TO 06 UTC SINCE OUR RAP-WEIGHTED
WIND FORECAST SUPPORTED SPEEDS SUFFICIENT FOR BLOWING AND DRIFTING
SNOW ISSUES THERE TOO. THE REST OF OUR PREVIOUSLY-ISSUED HEADLINES
WERE LEFT IN TACT. WE WILL PROBABLY HIT HIGH WIND CRITERIA FOR THE
SUSTAINED 50 MPH SPEEDS AT BIG TIMBER TODAY...BUT FELT IT WAS BEST
TO COVER THIS WITH ONE PRODUCT...THE WINTER WEATHER ADVISORY. NOTE
THAT IF WINDS IN SOUTH CENTRAL MT /NAMELY IN THE LIVINGSTON TO BIG
TIMBER CORRIDOR/ STAY UP PAST 12 UTC TUE MORNING AS SOME OF THE 00
UTC GUIDANCE SHOWS...PARTS OF THE ADVISORY MAY NEED TO BE EXTENDED
IN TIME WITH A LATER FORECAST RELEASE.
TONIGHT...THE SHORT WAVE WILL EXIT THE AREA...AND WINDS WILL BE ON
A DOWNWARD TREND /ESPECIALLY AFTER 06 UTC/...EVEN THOUGH THEY WILL
STAY GUSTY IN SOUTH CENTRAL MT. WE CAUTIOUSLY FOLLOWED THE LEAD OF
RECENTLY WELL-PERFORMING GUIDANCE THAT SHOWS LOWS ONLY AROUND 10 F
/MUCH WARMER THAN RECENT NIGHTS/ GIVEN EXPECTED LOW-LEVEL MIXING.
TUE...A LIGHT SNOW EVENT IS EXPECTED IN MANY AREAS AS A GOOD BATCH
OF QG-FORCING WITH ANOTHER SHORT WAVE TROUGH RIDES SOUTHEAST ALONG
THE THERMAL BOUNDARY LEFT BEHIND TODAY/S WAVE. IT LOOKS LIKE WINDS
WILL EVEN TURN NORTH OR NORTHEAST IN BILLINGS BY AFTERNOON...SO WE
WILL PROBABLY GET IN ON SOME LIGHT SNOW HERE TOO. WE HAD ENOUGH IN
THE WAY OF CONFIDENCE IN THIS WHOLE SCENARIO TO SIGNIFICANTLY RAMP
UP POPS IN MANY AREAS...GOING AS FAR AS 80 PERCENT FROM MILES CITY
TO HYSHAM AND DOWN TOWARD LAME DEER AND LODGE GRASS. THIS LOOKS TO
BE A GOOD 1 TO 2 INCH SNOW EVENT IN MANY AREAS. SCHULTZ
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
NORTHWEST FLOW ALOFT ON WEDNESDAY SLOWLY BECOMES A MORE WESTERLY
FLOW ON THURSDAY WHICH WILL ALLOW A LEESIDE SURFACE PRESSURE
TROUGH TO BE THE DOMINANT FEATURE EAST OF THE CONTINENTAL DIVIDE.
THIS PATTERN HOLDS UNTIL LATER ON FRIDAY WHEN AN UPPER LEVEL RIDGE
BUILDING INTO THE PACIFIC NORTHWEST TURNS THE FLOW NORTHWESTERLY
OVER MONTANA AND WYOMING. AT SOME POINT COLDER AIR OVER THE
DAKOTAS WILL HAVE A CHANCE TO PUSH A BACKDOOR COLD FRONT INTO
SOUTHERN MONTANA BUT WHEN IS NOT EXACTLY SURE...WHETHER IT WILL BE
FRIDAY NIGHT OR SATURDAY NIGHT. THIS IS THE BEST CHANCE FOR SNOW
IN THE PLAINS DURING THE EXTENDED PERIOD...THOUGH THE MODELS WILL
HAVE CHANCES FOR OROGRAPHIC SHOWERS AS THE FLOW ALOFT CONTINUES TO
BE FAIRLY MOIST.
TEMPERATURES WEDNESDAY THROUGH FRIDAY ARE GOING TO BE GOVERNED BY
A COUPLE OF FACTORS. DOWNSLOPE WINDS WILL BE FAVORED ACROSS THE
WESTERN AND CENTRAL ZONES BUT AIR WEST OF THE DIVIDE IS SO COLD
THAT THE WARMUP WILL BE MUCH SLOWER THAN NORMAL FOEHN WINDS WOULD
CREATE. ALSO...SNOW COVER WILL REGULATE A PART OF THE WARMUP AND
THE POSITION OF THE SURFACE TROUGH WILL SHOW THE EASTWARD EXTENT
OF THE BEST WARMING WITH TEMPERATURES STAYING COOLER EAST OF THE
TROUGH. BY THE WEEKEND THE PUSH WESTWARD OF THE COLD FRONT WILL
SUPPORT A DROP OF TEMPERATURES BUT AGAIN HOW FAR WEST AND HOW
DRAMATIC IS STILL NOT CERTAIN. WITH COLDER AIR POOLED UP WEST OF
THE DIVIDE WIND IS GOING TO BE A OMNIPRESENT FEATURE FOR THE
WESTERN ZONES. BORSUM
&&
.AVIATION...
FAST MOVING COLD FRONT WILL MOVE THROUGH EASTERN AND CENTRAL
MONTANA BRINGING INCREASED WINDS...BLOWING SNOW AND SNOW SHOWERS.
BEST CHANCE FOR SNOW WILL BE FOR EASTERN MONTANA WITH BLOWING SNOW
BEING THE BIGGEST PROBLEM FOR KBIL AND KLVM. VERY STRONG WINDS ARE
POSSIBLE FOR KLVM WITH DRIFTING AND BLOWING SNOW CREATING IFR
CONDITIONS AT TIMES. KBIL WILL SEE WINDS GUSTS TO 45 MPH WITH MVFR
CONDITIONS DUE TO BLOWING SNOW. KMLS WILL SEE LOWER CEILINGS IN
THE SNOW SHOWERS WITH IFR CONDITIONS AT TIMES. KSHR WILL SEE
CONDITIONS STAY MOSTLY VFR BUT WILL APPROACH MVFR CONDITIONS LATER
IN THE AFTERNOON. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 019 014/023 005/029 020/033 018/034 015/034 024/036
1/Q 16/S 51/B 11/B 11/B 11/B 11/B
LVM 016 010/022 007/026 020/032 021/034 019/032 024/033
2/J 24/S 42/J 11/N 12/J 11/B 11/N
HDN 022 012/022 901/027 014/035 015/032 012/032 022/036
2/J 28/S 51/B 11/B 11/E 11/B 12/B
MLS 020 009/016 907/023 010/031 013/026 010/028 020/035
9/J 38/S 21/B 11/B 12/J 11/B 22/B
4BQ 020 011/020 903/022 011/034 017/031 012/032 023/036
8/J 47/S 21/B 00/B 01/B 11/B 22/B
BHK 016 009/013 910/017 009/029 012/022 010/027 018/033
9/J 56/S 11/B 01/B 11/B 11/E 12/B
SHR 023 008/024 901/027 014/036 016/034 014/033 022/038
2/J 25/S 51/B 01/B 12/J 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 AM MST TUESDAY FOR
ZONES 28-29-34-35-39-41-42-56-63-65-66.
WIND CHILL ADVISORY IN EFFECT UNTIL 11 AM MST THIS MORNING
FOR ZONES 30>33-36>38-57-58.
WINTER WEATHER ADVISORY IN EFFECT FROM 11 AM THIS MORNING TO
11 PM MST THIS EVENING FOR ZONES 30>33-36>38-57-58.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1000 AM EST MON DEC 9 2013
.SYNOPSIS... A SLOW-MOVING FRONTAL SYSTEM WEST OF THE APPALACHIANS
THIS MORNING WILL DRIFT ACROSS OUR REGION TONIGHT AND TUESDAY.
CHILLY HIGH PRESSURE WILL BUILD INTO OUR REGION TUESDAY NIGHT AND
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM MONDAY...
NOT A LOT OF CHANGE NEEDED TO THE FORECAST THIS MORNING. THE CAD
AIRMASS IS FAIRLY WELL ENTRENCHED AND WILL STRUGGLE TO ERODE TODAY.
WHILE THE DEPTH OF THE RESIDUAL COLD POOL HAS DECREASED ON THE 12Z
KGSO RAOB...THERE IS STILL A UNIFORM 40KT FLOW AT 850MB AND ENOUGH
WARM ADVECTION TO KEEP STATIC STABILITY STRONG AND THE CAD LOCKED
IN. RAP AND HRR SOUNDINGS KEEP THE ENTIRE CWA MURKY WELL ON INTO
TONIGHT. THE CURRENT TEMP FORECAST IS AT THE LOWEST END OF THE
GUIDANCE SPECTRUM...SHOWING TEMPS RANGING FROM LOWER 40S TO UPPER
50S. THE BIGGEST POTENTIAL FOR ERROR WILL BE BETWEEN THE TRIANGLE
AND THE COASTAL PLAIN AS THE CAD BOUNDARY TRIES TO RETREAT NORTH AND
WESTWARD. REGARDING POPS...THE AXIS OF DEEPEST MOISTURE IS
CURRENTLY OVER WESTERN NC...AHEAD OF THE SLOW MOVING COLD FRONT WEST
OF THE MOUNTAINS. THE NARROW RAIN BAND THAT CURRENTLY EXTENDS FROM
WEST OF KCLT TO KGSO AND AND INTO VA APPEARS TO BE LINKED TO
ISENTROPIC LIFT BETWEEN 295K AND 305K...WHICH WEAKENS THIS AFTERNOON
AS ANOTHER WAVE OF LOW PRESSURE BEGINS TO FORM TO OUR SOUTHWEST
ALONG THE FRONT. EVEN IF A LULL DEVELOPS...DRIZZLE WILL
CONTINUE...SO HIGH POPS WILL BE MAINTAINED....PARTICULARLY WEST OF
HWY 1. -SMITH
TONIGHT: S/W ENERGY OVER THE CENTRAL ROCKIES WILL PUSH EASTWARD
TODAY INTO TONIGHT... HELPING TO PUSH A COLD FRONT EASTWARD TOWARDS
OUR REGION... WITH A SURFACE LOW DEVELOPING ALONG THE WEDGE FRONT
(AHEAD OF THE APPROACHING COLD FRONT) SOMEWHERE ACROSS OUR
SOUTHEAST/JUST TO THE SOUTH OF OUR REGION LATE TONIGHT. THIS SURFACE
LOW AND CONTINUED MID LEVEL S/W ENERGY EMBEDDED IN THE SOUTHWESTERLY
MID LEVEL FLOW WILL HELP SUPPORT A GOOD CHANCE OF RAIN AREAWIDE.
TEMPS MAY ACTUALLY RISE OR HOLD STEADY OVERNIGHT WHERE THE CAD HOLDS
TODAY. WILL GO WITH LOWS RANGING FROM THE LOW TO MID 40S NW TO LOW
TO MID 50S SE. -BSD
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM MONDAY...
TUESDAY...THE SURFACE LOW THAT DEVELOPS ALONG A FRONT SITUATED SW-NE
ACROSS CENTRAL NC WILL AID TO ENHANCE LOW LEVEL CONVERGENCE OVER OUR
REGION. ALOFT...A STRONG JET STREAKING ACROSS THE EASTERN LAKES INTO
SOUTHERN NEW ENGLAND WILL INCREASE UPPER LEVEL DIVERGENCE OVER THE
VIRGINIAS AND NC WHILE THE MID LEVEL S/W RESPONSIBLE FOR GENERATING
THE SURFACE WAVE OVERHEAD WILL QUICKLY SHEAR NEWD ACROSS THE TN AND
MID OH VALLEY. THE COMBINATION OF THE AVAILABLE LIFT AND MOISTURE
SUGGEST RAIN SHOULD BE WIDESPREAD ACROSS THE REGION TO START THE DAY
TUESDAY. MODEL GUIDANCE HAS VARIED AS TO WHERE THE AXIS OF
"HEAVIEST" PRECIP (A QUARTER TO A HALF INCH) WILL SET-UP.
HOWEVER...00Z GFS AND ECMWF HAVE COME INTO BETTER
AGREEMENT...FAVORING THE EASTERN PIEDMONT AND COASTAL PLAIN.
STILL...BETTER DYNAMICS ALOFT WILL RESIDE OVER THE NW PIEDMONT. AT
THIS TIME PLAN TO BROADBRUSH THE PRECIP AMOUNTS ACROSS THE REGION
WITH TWO TO THREE TENTHS EXPECTED IN THE 12Z-18Z TUESDAY TIME FRAME.
MID LEVEL S/W WILL QUICKLY SHEAR OUT TO THE NE TUESDAY
AFTERNOON...PROPELLING THE SURFACE FRONT EASTWARD TO THE COAST BY
TUESDAY AFTERNOON. THUS...SHOULD SEE PRECIP TAPER OFF WEST-TO-EAST
TUESDAY AFTERNOON ACROSS CENTRAL NC. DEVELOPING NW FLOW IN THE LOWER
LEVELS WILL LEAD TO DECREASING CLOUDINESS LATE IN THE DAY.
DEVELOPING DOWNSLOPE FLOW WILL INITIALLY OFFSET COLD AIR ADVECTION.
RESIDUAL CAD AIR MASS ACROSS THE NORTH-NW PIEDMONT SHOULD HOLD TEMPS
IN THE 40S. EXPECT WARMER TEMPS OVER THE SOUTHERN COUNTIES WHERE
TEMPS IN THE 50S (AROUND 60 FAR SE) PROBABLE.
COLDER DRIER AIR WILL OVERSPREAD CENTRAL NC TUESDAY NIGHT AS A
MODIFIED CANADIAN HIGH PRESSURE SYSTEM BUILDS INTO THE REGION.
PARENT HIGH EXPECTED TO BE CENTERED OVER THE CENTRAL APPALACHIANS BY
EARLY WEDNESDAY WITH A SURFACE RIDGE EXTENDING INTO NC. THUS...WHILE
EARLY TUESDAY EVENING WILL BE A BIT BREEZY...LOOKS PLAUSIBLE FOR SFC
WINDS TO DECOUPLE AFTER MIDNIGHT. THIS WILL ALLOW TEMPS TO FALL INTO
THE 20S BY DAYBREAK WEDNESDAY ACROSS THE NORTH...AND NEAR 30 ACROSS
THE SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
WEDNESDAY THROUGH FRIDAY...RELATIVELY TRANQUIL WEATHER PERIOD
ANTICIPATED FROM MID WEEK TO THE END OF THE WEEK AS BROAD UPPER
TROUGH COVERS THE EASTERN TWO-THIRDS OF THE NATION. THE NORTHERN
BRANCH WILL BE DOMINATE IN THE BEGINNING...KEEPING THE STORM TRACK
MAINLY ACROSS THE NORTHERN PLAINS-GREAT LAKES AND NEW ENGLAND. THE
SURFACE HIGH THAT COVERS OUR REGION WEDNESDAY WILL QUICKLY SCOOT EWD
BY LATE WEDNESDAY BUT IS REPLACED BY ANOTHER CHILLY HIGH THAT BUILDS
INTO THE MID ATLANTIC IN THE WAKE OF A MID LEVEL S/W CROSSES THE
GREAT LAKES INTO NEW ENGLAND. THUS OUR CURRENT STRETCH OF BE LOW
NORMAL TEMPS WILL CONTINUE. HIGH TEMPS WED AND THU WILL BE IN THE
40S WHILE MIN TEMPS WILL BE IN THE 20S TO AROUND 30.
SATURDAY INTO SUNDAY...OPERATIONAL GFS AND ECMWF OFFER A SIMILAR
SOLUTION FOR THE UPCOMING WEEKEND WEATHER PATTERN...IN SHARP
CONTRAST TOT E 12Z MODEL RUNS WHICH DEPICTED A SOLUTION VERY SIMILAR
TO OUR CURRENT WEATHER PATTERN. MODEL GUIDANCE NOW ADVERTISING A
RETURN FLOW REGIME BECOMING ESTABLISHED FRIDAY NIGHT INTO
SATURDAY...AHEAD OF A FRONTAL SYSTEM DOMINATED BY A S/W IN THE
NORTHERN STREAM. THIS FRONTAL SYSTEM CROSSES OUR REGION SATURDAY
NIGHT WITH CHILLY HIGH PRESSURE BUILDING INTO OUR REGION SUNDAY. FOR
NOW WILL CONFINE THE BEST CHANCE FOR PRECIP TO SATURDAY AND KEEP IT
ALL LIQUID. IF PRECIP COMES INTO THE REGION EARLY ENOUGH FRIDAY
NIGHT...MAY START OUT AS A WINTRY MIX BEFORE QUICKLY TRANSITIONING
TO ALL RAIN. TEMPS EXPECTED TO REMAIN BELOW NORMAL AND HIGHLY
DEPENDENT UPON PRECIP COVERAGE. HIGHS IN THE 40S TO AROUND 50. LOWS
TEMPS IN THE 30S FRIDAY NIGHT AND 30S TO AROUND 40 SATURDAY NIGHT.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AS OF 730 AM MONDAY...
24-HR TAF PERIOD: ADVERSE AVIATION CONDITIONS WILL PREVAIL THROUGH
THE TAF PERIOD. EXPECT LIFR CEILINGS THIS MORNING TO CONTINUE
THROUGH AT LEAST MID MORNING... WITH VISBYS POSSIBLY DROPPING TO A
MILE OR LESS OVER THE NEXT COUPLE OF HOURS AS WELL (POSSIBLY LASTING
UNTIL MID MORNING TOO). PERIODS OF RAIN AND DRIZZLE WILL BE POSSIBLE
AT KGSO/KINT/KRDU TODAY... WITH MORE PATCHY RAIN AND DRIZZLE AT KRWI
AND KFAY. EXPECT CIGS WILL BE VERY SLOW TO IMPROVE TODAY... AND MAY
ONLY IMPROVE TO IFR CIGS GIVEN THE CAD AIRMASS OVER CENTRAL NC. IN
ADDITION TO THE POOR CIGS/VISBYS AND RAIN/DRIZZLE... SOUTHWESTERLY
WINDS OF AROUND 40-50 KTS ARE EXPECTED AT AROUND 2 KFT ABOVE THE
SURFACE TODAY... CREATING LOW LEVEL WINDS SHEAR CONDITIONS. THUS...
HAVE ADDED LLWS TO THE TAFS FOR TODAY. EXPECT WINDS AT AROUND 2 KFT
TO WEAKEN BETWEEN 21-00Z TODAY.
LIFR CONDITIONS ARE AGAIN EXPECTED TONIGHT... AS CIGS LOWER AND
VISBYS DROP AFTER 00-03Z. CHANCES FOR RAIN/DRIZZLE WILL CONTINUE AS
WELL.
LOOKING AHEAD: ADVERSE CONDITIONS (IFR/MVFR AND PERHAPS LIFR)
ASSOC/W THE COLD AIR DAMMING WEDGE WILL MOST LIKELY LINGER INTO THE
DAY TUESDAY AS A COLD FRONT APPROACHES FROM THE WEST. VFR CONDITIONS
WILL RETURN TUE NIGHT AS DRY HIGH PRESSURE BUILDS INTO THE REGION
FROM THE WEST. VFR/DRY CONDITIONS ARE EXPECTED TO PREVAIL THROUGH
THE REMAINDER OF THE WORK WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...BSD/SMITH
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...BSD/VINCENT
AREA FORECAST DISCUSSION
NWS BISMARCK ND
638 AM CST MON DEC 9 2013
.UPDATE...
ISSUED AT 638 AM CST MON DEC 9 2013
NO CHANGES TO THE EARLY MORNING FORECAST ARE NEEDED AT THIS TIME.
ARCTIC HIGH PRESSURE CENTERED OVER EASTERN MONTANA IS PRODUCING
MOSTLY CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY
THIS MORNING. TEMPERATURES AT 6 AM CST WERE GENERALLY 10 TO 20
BELOW WITH WIND CHILLS OF 20 TO 35 BELOW. THE WIND CHILL ADVISORY
CONTINUES THROUGH NOON TODAY. OUR NEXT WEATHER SYSTEM IS CURRENTLY
TAKING SHAPE OVER ALBERTA. THE 10 UTC HRRR IS INDICATING LIGHT
SNOW MOVING INTO WESTERN NORTH DAKOTA BETWEEN 17 AND 18
UTC...WHICH LINES UP WELL WITH THE LATEST FORECAST POPS. STRONGER
WINDS ARE ALSO PROGGED BY THE HRRR TO MOVE INTO KDIK AND KISN
AROUND 21 UTC WHICH IS WHEN THE BLOWING SNOW ADVISORY BEGINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST MON DEC 9 2013
THE HIGHLIGHTS OF THE SHORT TERM ARE DANGEROUS MORNING WIND
CHILLS...FOLLOWED BY BLOWING SNOW THIS AFTERNOON AND EVENING.
THE WIND CHILL ADVISORY REMAINS IN EFFECT FOR ALL OF WESTERN AND
CENTRAL NORTH DAKOTA THROUGH 18 UTC AS WIND CHILLS TO -35 F WILL
CONTINUE THIS MORNING. WIND CHILLS CLIMB ABOVE THE -25 F THRESHOLD
FOR ALL LOCATIONS EXCEPT POSSIBLY THE TURTLE MOUNTAINS THIS
AFTERNOON.
OTHERWISE...AN ALBERTA CLIPPER WILL PROPAGATE ACROSS NORTH CENTRAL
INTO SOUTHEAST NORTH DAKOTA LATE THIS AFTERNOON AND INTO THE
EVENING. THE AREA OF GREATEST CONCERN IS WEST OF THE SURFACE LOW
ACROSS WESTERN AND PORTIONS OF NORTH CENTRAL NORTH DAKOTA WHERE A
WINTER WEATHER ADVISORY IS IN EFFECT FOR THIS AFTERNOON AND
EVENING. THE 00 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A
BAND OF LIGHT SNOW ALONG AND WEST OF THE SURFACE LOW TRACK...WITH
NEW SNOWFALL AMOUNTS OF GENERALLY ONE INCH OR LESS OF VERY
FLUFFY...DRY SNOW GIVEN THE COLD TEMPERATURES. STRONG NORTHWEST
WINDS ARE ALSO EXPECTED FOR THESE AREAS...GENERALLY AS THE FALLING
SNOW IS ENDING. BASED ON THE 00 UTC NAM/GFS BUFR SOUNDINGS...THE
STRONGEST WINDS ARE EXPECTED ACROSS THE SOUTHWEST WHERE ADIABATIC
LAPSE RATES TO 850-800 MB WITH 45-50 KTS OF WIND AT THE TOP OF THE
MIXED LAYER ARE EXPECTED. THE ONE CAVEAT TO MAXIMIZING WIND GUSTS
WILL BE THE RELATIVE LACK OF STRONG COLD AIR ADVECTION...WITH
PERHAPS VERY WEAK WARM AIR ADVECTION BY EVENING. DID CONSIDER THE
POTENTIAL FOR A GROUND BLIZZARD. HOWEVER...AT THIS TIME COMPACTED
SNOW DEPTHS OF 2 TO 6 INCHES ACROSS MUCH OF WESTERN NORTH DAKOTA
AND THE STRONGEST WINDS NOT OCCURRING AT THE SAME TIME AS THE
HEIGHT OF THE FALLING SNOW SHOULD LIMIT BLIZZARD CRITERIA BEING
MET. THAT SAID...WIDESPREAD BLOWING SNOW AND REDUCED VISIBILITIES
TO ONE HALF MILE ARE EXPECTED...AND CONDITIONS WILL HAVE TO BE
MONITORED CLOSELY SHOULD A BLIZZARD WARNING BE NEEDED. THE AREA
MOST FAVORED FOR THIS POTENTIAL IS THE AMIDON...RHAME AND MARMARTH
AREAS WHERE THE SNOW PACK IS LOCALLY GREATER AND WINDS ARE
EXPECTED TO BE THE STRONGEST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 332 AM CST MON DEC 9 2013
THE MAIN FORECAST CONCERNS IN THE LONG TERM WILL BE POSSIBLE BLOWING
SNOW HIGHLIGHTS ON TUESDAY...THEN TEMPERATURES AND LIGHT SNOW
CHANCES THURSDAY THROUGH SUNDAY NIGHT ALONG AN UNDULATING BAROCLINIC
ZONE OVER THE NORTHERN PLAINS.
CURRENT WINTER WEATHER ADVISORY FOR BLOWING SNOW GOES THROUGH 06 UTC
TUESDAY. IT APPEARS THAT THE STRONGEST BOUNDARY LAYER WINDS WILL BE
MOVING THROUGH CENTRAL NORTH DAKOTA AROUND 06 UTC. WINDS SHOULD
WEAKEN THROUGH 12 UTC TUESDAY AS THE COLD ADVECTION ENDS AND
PRESSURE FALL RISE COUPLET HAS MOVED EAST OF THE AREA. WINDS
INCREASE AGAIN ON TUESDAY AS ANOTHER PIECE OF ARCTIC HIGH PRESSURE
DROPS INTO THE AREA. WINDS WILL NOT BE AS STRONG AS MONDAY AND WE
SHOULD GET A GOOD IDEA ON THE IMPACTS OF THE BLOWING SNOW MONDAY TO
DISCERN WHETHER OR NOT THE ADVISORY WILL NEED TO BE EXTENDED INTO
TUESDAY. THEREFORE WILL NOT ISSUE ANYTHING AT THIS TIME.
COLD AND DRY ON WEDNESDAY AS THE ARCTIC HIGH TRACKS SOUTHEAST ACROSS
THE FORECAST AREA.
THURSDAY THROUGH SUNDAY NIGHT A NORTHWEST FLOW PATTERN TAKES SHAPE.
SHORTWAVES MOVING THROUGH THE MEAN FLOW WILL INDUCE LEE SIDE LOW
PRESSURE SYSTEMS THAT WILL TRACK SOUTHEAST FROM THE NORTHERN HIGH
PLAINS INTO THE CENTRAL AND NORTHERN PLAINS. EACH LOW WILL PRODUCE
AN AREA OF LIGHT WARM ADVECTION SNOWS OVER WESTERN AND CENTRAL NORTH
DAKOTA AS THE RIDE SOUTHEAST ALONG THE BAROCLINIC ZONE. IN
ADDITION...EACH WAVE SHOULD BRING IN A LITTLE WARMER AIR...WITH
HIGHS POSSIBLY CLIMBING ABOVE FREEZING BY SUNDAY OVER THE SOUTHWEST.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 638 AM CST MON DEC 9 2013
ANOTHER MORNING OF SCATTERED STRATUS DECKS WITH FLURRIES THAT ARE
HARD TO SEE ON SATELLITE AND RADAR WILL CONTINUE. ALTHOUGH THE
SATELLITE HAS SHOWN A DECREASING TREND IN STRATUS OVER THE PAST
FEW HOURS AND HAVE STARTED EVERYONE OFF MAINLY CLEAR OR WITH ONLY
A SCATTERED STRATUS DECK AND NO FLURRIES. THEREAFTER...AN ALBERTA
CLIPPER WILL IMPACT WESTERN AND CENTRAL NORTH DAKOTA MONDAY
AFTERNOON AND EVENING. IFR CONDITIONS IN SNOW...BLOWING SNOW AND
STRONG NORTHWEST WINDS ARE EXPECTED.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 PM CST /2 PM MST/ THIS AFTERNOON
TO MIDNIGHT CST /11 PM MST/ TONIGHT FOR NDZ001>004-009>012-
017>019-021-031>033-040-041-043-044.
WIND CHILL ADVISORY UNTIL NOON CST /11 AM MST/ TODAY FOR
NDZ001>005-009>013-017>023-025-031>037-040>048-050-051.
&&
$$
UPDATE...TWH
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...TWH
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
637 AM EST MON DEC 9 2013
.SYNOPSIS...
A LOW PRESSURE WAVE CROSSES TODAY. A WEAK SYSTEM CROSSES LATE
TONIGHT INTO TUESDAY WITH SOME SNOW EXPECTED. CHILLY DRY HIGH
PRESSURE FOR WEDNESDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
630 AM UPDATE...
UPDATE TO CANCEL REMAINING WINTER WX ADVISORY AND WARNING FOR
EASTERN MOUNTAINS. A FEW ISOLATED PATCHES OF MAINLY FREEZING
DRIZZLE WITH VERY LIGHT ACCUMULATIONS MAY STILL BE POSSIBLE FOR
ANOTHER HOUR OR SO THIS MORNING ACROSS THE FAR EASTERN PORTIONS OF
THE EASTERN MOUNTAIN COUNTIES.
PREVIOUS DISCUSSION...
MAINLY ZONAL FLOW WILL PREVAIL TODAY...WITH AREAS OF CLEARING
SPREADING FROM WEST TO EAST. MODELS SHOW AN MID TO UPPER AIR VORT
MAX ASSOCIATED WITH AN H5 SHORTWAVE CROSSING THE AREA BY 18
TUESDAY.
LATEST RADAR IMAGES SHOW A BAND OF RAIN SHOWING SIGNS OF BREAKING
UP WITH RAIN DIMINISHING IN INTENSITY. WITH SATURATED
TERRAIN...KEPT FLOOD WATCH FOR THE WESTERN SLOPES OF WV...SOUTHWEST
VA AND SOUTHERN COAL FIELDS AS SOME DECENT PRECIPITATION AMOUNTS...0.5
TO 0.75 INCHES IN 6 HOURS HAVE BEEN REPORTED.
WINTER WEATHER ADVISORIES REMAIN IN EFFECT FROM RALEIGH...NORTH TO
WEBSTER FOR FREEZING RAIN AND SNOW...WHILE WINTER STORM WARNING
REMAINS IN EFFECT FOR POCAHONTAS AND RANDOLPH COUNTIES THROUGH 12Z
MONDAY.
WARM ADVECTION SHOULD CONTINUE THROUGH THE NIGHT...SO HAVE NON-
DIURNAL TEMPERATURES...BASED HEAVILY ON THE RAP AND WRF GUIDANCE.
WENT WITH THE WRF AND THE GFS GUIDANCE FOR TEMPERATURE THROUGH THE
PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
ACTIVE AT THE OUTSET OF THE PERIOD ON TUESDAY MORNING WITH A
QUICK-HITTING SYSTEM PUSHING ACROSS THE AREA. YET ANOTHER WAVE OF
LOW PRESSURE WILL BE RIDING ALONG THE QUASI-STATIONARY FRONT STILL
TO OUR SOUTHEAST WHICH IS PROGGED TO BE LOCATED NEAR THE TN/NC/GA
AREA AT 12Z TUE. MEANWHILE AN UPPER TROUGH WILL BE PROGRESSING
EASTWARD QUICKLY ACROSS THE LOWER/MID OHIO RIVER VALLEY TUE MORNING.
EXPECT TWO DISTINCT AREAS OF PRECIP AT THE OUTSET...ONE ENTERING THE
SE OHIO ZONES AND THE OTHER PUSHING UP FROM THE SW WITH THE SFC LOW.
THESE SHOULD MERGE OVER THE NORTHEAST ZONES BY MID-LATE MORNING ON
IT/S WAY OUT OF OUR AREA. VARIOUS QPF OUTPUT DEPICTING ROUGHLY
0.1-0.2 INCHES IN GENERAL...WITH SOME HIGHER AMOUNTS PARTICULARLY ON
THE FINER RESOLUTION NAM12. TOUGH CALL ON SNOWFALL AMOUNTS WITH SOME
DIFFERENCES IN TIMING OF THE HIGHEST QPF AND WITH THE SYSTEM BEING
SUCH A FAST-MOVER. A GENERAL INCH OR SO APPEARS REASONABLE FOR MUCH
OF THE LOWLANDS LATE MON NIGHT GOING INTO TUE MORNING. THE AREA
HOWEVER COMES UNDER INFLUENCE OF RIGHT ENTRANCE REGION OF STRONG JET
JUST TO OUR NORTHWEST AROUND THE 12Z TUE TIME FRAME WITH GOOD
UNIDIRECTIONAL SPEED SHEAR. A BIT CONCERNED WITH PROGGED EPV AND
THETA-E LAPSE RATE VALS WITH GOOD SATURATION ABOVE THE COLD
DOME...NOT TO MENTION SOME WEAK ELEVATED CAPE...THAT SOME LOCATIONS
MAY SEE SOME ENHANCEMENT OF SNOWFALL RATES/ACCUMULATIONS IN NARROW
MESOSCALE BANDS THROUGH SLANTWISE AND/OR UPRIGHT CONVECTION.
CONSIDERED AN ADVISORY FOR TUE MORNING...BUT AFTER COLLABORATION
WITH SURROUNDING OFFICES DECIDED TO ALLOW DAY SHIFT ONE MORE LOOK AT
LATEST DATA. DID BUMP UP SNOW AMOUNTS...AGAIN...TO AROUND THE 1-2
INCH RANGE WITH SOME 2-3 ACROSS THE NORTHEAST ZONES. SNOWFALL WILL
PRIMARILY BE CONFINED NEAR THE EASTERN MOUNTAINS BY 18Z TUE WITH
ONLY A SLIGHT CHANCE OF LIGHT SNOW REMAINING BY 00Z WED. ALSO NUDGED
MAX TEMPS DOWN A BIT TUESDAY PER LATEST MOS GUIDANCE AND 925MB TEMPS
SUPPORTING. MANY LOCATIONS TUESDAY WILL STRUGGLE TO REACH THE
FREEZING MARK.
HIGH PRESSURE PUSHES IN FROM THE WEST TUESDAY NIGHT AND WEDNESDAY
WITH RAPIDLY CLEARING SKIES TUESDAY NIGHT WITH HIGH PRESSURE CENTER
LOCATED OVER THE SOUTHERN ZONES BY 12Z WED. CLEARING SKIES AND LIGHT
WINDS WILL ALLOW GOOD COOLING WITH TEENS EXPECTED FOR MOST
LOCATIONS...AND EVEN SOME SINGLE DIGITS POSSIBLE OVER SE OHIO AND OF
COURSE THE EASTERN HIGH COUNTRY. AN UPPER TROUGH WILL PASS BY TO THE
NORTH OF THE FORECAST AREA WEDNESDAY RESULTING IN PERHAPS A FEW MORE
CLOUDS NORTH. BUT OTHERWISE A DRY AND SUNNY...BUT COOL...DAY IS ON
TAP FOR WEDNESDAY. MAX TEMPS GENERALLY IN THE LOW/MID 30S FOR THE
LOWLANDS STILL APPEAR ON TRACK WITH VERY LITTLE CHANGE FROM PREV
FCST. SFC WINDS WILL COME AROUND TO THE SOUTHWEST AS SFC HIGH
CONTINUES TO PUSH OFF TO THE EAST. A QUICK MOVING FRONT WILL PUSH
ACROSS THE AREA WED NIGHT...BUT LITTLE MOISTURE WITH IT RESULTS IN
ONLY A BRIEF INCREASE IN CLOUD COVER AND SOME BREEZY POST-FRONTAL
WINDS WED NIGHT...EXCEPT FOR THE FAR NORTHEAST ZONES WHERE JUST
ENOUGH MOISTURE DEPTH MAY BE ENOUGH TO SQUEEZE OUT A LIGHT SNOW
SHOWER. THUS WILL CARRY SLIGHT CHANCE POPS HERE WED NIGHT. SNOW
ACCUMS WILL NOT BE AN ISSUE HOWEVER...WITH ONLY A DUSTING TO A FEW
TENTHS POSSIBLE. MINS AGAIN WILL BE JUST ABOUT IDENTICAL TO TUE
NIGHT/S...WITH TEENS EXPECTED FOR MOST LOWLANDS AND PERHAPS LOWER
20S FOR THE COALFIELDS.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
STILL JUST WHAT THE DOCTOR ORDERED. A MOSTLY DRY PATTERN
WEDNESDAY NIGHT INTO SATURDAY. HAVE A SLIGHT CHANCE OF SOME
LIGHT SNOW SHOWERS WEDNESDAY NIGHT ACROSS THE NORTHERN WV
MOUNTAINS.
DRY AIR AND THE LONG DECEMBER NIGHTS YIELDS COLD DAWN TEMPERATURES.
DOWN THE ROAD...MOISTURE INCREASES SATURDAY...HAVE SOME CHANCE POPS
BY SATURDAY FOR RAIN AND SNOW. STILL APPEARS NOT A HEAVY EVENT.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LIFR CONDITIONS WILL PREVAIL THIS MORNING AS THE LAST AREAS OF
RAIN ASSOCIATED WITH LAST COLD FRONT EXITS EAST OF THE MOUNTAINS
LATE THIS MORNING. PERIODS OF IFR/LIFR VISIBILITIES ARE POSSIBLE
DURING THE PREDAWN HOURS...PERHAPS LASTING UNTIL 14Z AT SOME
PLACES.
ANOTHER ROUND OF SNOW SHOWERS WILL APPROACH FROM THE NORTHWEST
LATER TONIGHT FOR IFR/LIFR CONDITIONS ALOND THE SHOWER.
AREAS OF LIFR CIGS DEVELOPING MAINLY 03Z THROUGH 14Z OVERNIGHT...LIFTING
TO IFR/MVFR FOR REMAINDER OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF IFR/LIFR CIGS MAY VARY FROM CURRENT FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H M M M H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M M M M M M M H H H H
EKN CONSISTENCY H H H M M M L H H H H H
PKB CONSISTENCY H M H M M H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR POSSIBLE IN SNOW MONDAY NIGHT INTO TUESDAY.
&&
.EQUIPMENT...
ADDITIONAL PARTS FOR PARKERSBURG ASOS ARE EXPECTED TO ARRIVE MONDAY.
AUTOMATED OBSERVATIONS WILL BE UNAVAILABLE AT TIMES UNTIL THEN.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...NONE.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ
NEAR TERM...ARJ/50
SHORT TERM...50
LONG TERM...KTB
AVIATION...ARJ
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
548 AM EST MON DEC 9 2013
.SYNOPSIS...
A LOW PRESSURE WAVE CROSSES TODAY. A WEAK SYSTEM CROSSES LATE
TONIGHT INTO TUESDAY WITH SOME SNOW EXPECTED. CHILLY DRY HIGH
PRESSURE FOR WEDNESDAY INTO FRIDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
MAINLY ZONAL FLOW WILL PREVAIL TODAY...WITH AREAS OF CLEARING
SPREADING FROM WEST TO EAST. MODELS SHOW AN MID TO UPPER AIR VORT
MAX ASSOCIATED WITH AN H5 SHORTWAVE CROSSING THE AREA BY 18
TUESDAY.
LATEST RADAR IMAGES SHOW A BAND OF RAIN SHOWING SIGNS OF BREAKING
UP WITH RAIN DIMINISHING IN INTENSITY. WITH SATURATED
TERRAIN...KEPT FLOOD WATCH FOR THE WESTERN SLOPES OF WV...SOUTHWEST
VA AND SOUTHERN COAL FIELDS AS SOME DECENT PRECIPITATION AMOUNTS...0.5
TO 0.75 INCHES IN 6 HOURS HAVE BEEN REPORTED.
WINTER WEATHER ADVISORIES REMAIN IN EFFECT FROM RALEIGH...NORTH TO
WEBSTER FOR FREEZING RAIN AND SNOW...WHILE WINTER STORM WARNING
REMAINS IN EFFECT FOR POCAHONTAS AND RANDOLPH COUNTIES THROUGH 12Z
MONDAY.
WARM ADVECTION SHOULD CONTINUE THROUGH THE NIGHT...SO HAVE NON-
DIURNAL TEMPERATURES...BASED HEAVILY ON THE RAP AND WRF GUIDANCE.
WENT WITH THE WRF AND THE GFS GUIDANCE FOR TEMPERATURE THROUGH THE
PERIOD.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ACTIVE AT THE OUTSET OF THE PERIOD ON TUESDAY MORNING WITH A
QUICK-HITTING SYSTEM PUSHING ACROSS THE AREA. YET ANOTHER WAVE OF
LOW PRESSURE WILL BE RIDING ALONG THE QUASI-STATIONARY FRONT STILL
TO OUR SOUTHEAST WHICH IS PROGGED TO BE LOCATED NEAR THE TN/NC/GA
AREA AT 12Z TUE. MEANWHILE AN UPPER TROUGH WILL BE PROGRESSING
EASTWARD QUICKLY ACROSS THE LOWER/MID OHIO RIVER VALLEY TUE MORNING.
EXPECT TWO DISTINCT AREAS OF PRECIP AT THE OUTSET...ONE ENTERING THE
SE OHIO ZONES AND THE OTHER PUSHING UP FROM THE SW WITH THE SFC LOW.
THESE SHOULD MERGE OVER THE NORTHEAST ZONES BY MID-LATE MORNING ON
IT/S WAY OUT OF OUR AREA. VARIOUS QPF OUTPUT DEPICTING ROUGHLY
0.1-0.2 INCHES IN GENERAL...WITH SOME HIGHER AMOUNTS PARTICULARLY ON
THE FINER RESOLUTION NAM12. TOUGH CALL ON SNOWFALL AMOUNTS WITH SOME
DIFFERENCES IN TIMING OF THE HIGHEST QPF AND WITH THE SYSTEM BEING
SUCH A FAST-MOVER. A GENERAL INCH OR SO APPEARS REASONABLE FOR MUCH
OF THE LOWLANDS LATE MON NIGHT GOING INTO TUE MORNING. THE AREA
HOWEVER COMES UNDER INFLUENCE OF RIGHT ENTRANCE REGION OF STRONG JET
JUST TO OUR NORTHWEST AROUND THE 12Z TUE TIME FRAME WITH GOOD
UNIDIRECTIONAL SPEED SHEAR. A BIT CONCERNED WITH PROGGED EPV AND
THETA-E LAPSE RATE VALS WITH GOOD SATURATION ABOVE THE COLD
DOME...NOT TO MENTION SOME WEAK ELEVATED CAPE...THAT SOME LOCATIONS
MAY SEE SOME ENHANCEMENT OF SNOWFALL RATES/ACCUMULATIONS IN NARROW
MESOSCALE BANDS THROUGH SLANTWISE AND/OR UPRIGHT CONVECTION.
CONSIDERED AN ADVISORY FOR TUE MORNING...BUT AFTER COLLABORATION
WITH SURROUNDING OFFICES DECIDED TO ALLOW DAY SHIFT ONE MORE LOOK AT
LATEST DATA. DID BUMP UP SNOW AMOUNTS...AGAIN...TO AROUND THE 1-2
INCH RANGE WITH SOME 2-3 ACROSS THE NORTHEAST ZONES. SNOWFALL WILL
PRIMARILY BE CONFINED NEAR THE EASTERN MOUNTAINS BY 18Z TUE WITH
ONLY A SLIGHT CHANCE OF LIGHT SNOW REMAINING BY 00Z WED. ALSO NUDGED
MAX TEMPS DOWN A BIT TUESDAY PER LATEST MOS GUIDANCE AND 925MB TEMPS
SUPPORTING. MANY LOCATIONS TUESDAY WILL STRUGGLE TO REACH THE
FREEZING MARK.
HIGH PRESSURE PUSHES IN FROM THE WEST TUESDAY NIGHT AND WEDNESDAY
WITH RAPIDLY CLEARING SKIES TUESDAY NIGHT WITH HIGH PRESSURE CENTER
LOCATED OVER THE SOUTHERN ZONES BY 12Z WED. CLEARING SKIES AND LIGHT
WINDS WILL ALLOW GOOD COOLING WITH TEENS EXPECTED FOR MOST
LOCATIONS...AND EVEN SOME SINGLE DIGITS POSSIBLE OVER SE OHIO AND OF
COURSE THE EASTERN HIGH COUNTRY. AN UPPER TROUGH WILL PASS BY TO THE
NORTH OF THE FORECAST AREA WEDNESDAY RESULTING IN PERHAPS A FEW MORE
CLOUDS NORTH. BUT OTHERWISE A DRY AND SUNNY...BUT COOL...DAY IS ON
TAP FOR WEDNESDAY. MAX TEMPS GENERALLY IN THE LOW/MID 30S FOR THE
LOWLANDS STILL APPEAR ON TRACK WITH VERY LITTLE CHANGE FROM PREV
FCST. SFC WINDS WILL COME AROUND TO THE SOUTHWEST AS SFC HIGH
CONTINUES TO PUSH OFF TO THE EAST. A QUICK MOVING FRONT WILL PUSH
ACROSS THE AREA WED NIGHT...BUT LITTLE MOISTURE WITH IT RESULTS IN
ONLY A BRIEF INCREASE IN CLOUD COVER AND SOME BREEZY POST-FRONTAL
WINDS WED NIGHT...EXCEPT FOR THE FAR NORTHEAST ZONES WHERE JUST
ENOUGH MOISTURE DEPTH MAY BE ENOUGH TO SQUEEZE OUT A LIGHT SNOW
SHOWER. THUS WILL CARRY SLIGHT CHANCE POPS HERE WED NIGHT. SNOW
ACCUMS WILL NOT BE AN ISSUE HOWEVER...WITH ONLY A DUSTING TO A FEW
TENTHS POSSIBLE. MINS AGAIN WILL BE JUST ABOUT IDENTICAL TO TUE
NIGHT/S...WITH TEENS EXPECTED FOR MOST LOWLANDS AND PERHAPS LOWER
20S FOR THE COALFIELDS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
STILL JUST WHAT THE DOCTOR ORDERED. A MOSTLY DRY PATTERN
WEDNESDAY NIGHT INTO SATURDAY. HAVE A SLIGHT CHANCE OF SOME
LIGHT SNOW SHOWERS WEDNESDAY NIGHT ACROSS THE NORTHERN WV
MOUNTAINS.
DRY AIR AND THE LONG DECEMBER NIGHTS YIELDS COLD DAWN TEMPERATURES.
DOWN THE ROAD...MOISTURE INCREASES SATURDAY...HAVE SOME CHANCE POPS
BY SATURDAY FOR RAIN AND SNOW. STILL APPEARS NOT A HEAVY EVENT.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
LIFR CONDITIONS WILL PREVAIL THIS MORNING AS THE LAST AREAS OF
RAIN ASSOCIATED WITH LAST COLD FRONT EXITS EAST OF THE MOUNTAINS
LATE THIS MORNING. PERIODS OF IFR/LIFR VISIBILITIES ARE POSSIBLE
DURING THE PREDAWN HOURS...PERHAPS LASTING UNTIL 14Z AT SOME
PLACES.
ANOTHER ROUND OF SNOW SHOWERS WILL APPROACH FROM THE NORTHWEST
LATER TONIGHT FOR IFR/LIFR CONDITIONS ALOND THE SHOWER.
AREAS OF LIFR CIGS DEVELOPING MAINLY 03Z THROUGH 14Z OVERNIGHT...LIFTING
TO IFR/MVFR FOR REMAINDER OF TAF PERIOD.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 12Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF IFR/LIFR CIGS MAY VARY FROM CURRENT FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 11 12 13 14 15 16 17 18 19 20 21 22
EST 1HRLY 06 07 08 09 10 11 12 13 14 15 16 17
CRW CONSISTENCY H H H H H H M M M H H H
HTS CONSISTENCY H H H H H H H H H H H H
BKW CONSISTENCY M M M M M M M M H H H H
EKN CONSISTENCY H H H M M M L H H H H H
PKB CONSISTENCY H M H M M H H H H H H H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 12Z TUESDAY...
IFR POSSIBLE IN SNOW MONDAY NIGHT INTO TUESDAY.
&&
&&
.EQUIPMENT...
ADDITIONAL PARTS FOR PARKERSBURG ASOS ARE EXPECTED TO ARRIVE MONDAY.
AUTOMATED OBSERVATIONS WILL BE UNAVAILABLE AT TIMES UNTIL THEN.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER STORM WARNING UNTIL 7 AM EST THIS MORNING FOR WVZ035-
036-046-047.
WINTER WEATHER ADVISORY UNTIL 7 AM EST THIS MORNING FOR WVZ037-
038.
OH...NONE.
KY...NONE.
VA...NONE.
&&
$$
SYNOPSIS...ARJ
NEAR TERM...50
SHORT TERM...TRM
LONG TERM...KTB
AVIATION...ARJ
HYDROLOGY...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS PORTLAND OR
400 AM PST MON DEC 9 2013
.SYNOPSIS...ANOTHER VERY COLD NIGHT AS ARCTIC HIGH PRESSURE REMAINS
DOMINANT OVER THE PACIFIC NORTHWEST. LOWER PRESSURE OFFSHORE
CONTINUES TO DRIVE WEAK EASTERLY FLOW THROUGH THE COLUMBIA GORGE AND
INTO THE PORTLAND AREA. A WEAK CLIPPER SYSTEM WILL PUSH DOWN FROM
THE YUKON LATER TODAY...BRINGING A CHANCE OF SNOW AND OR FREEZING
DRIZZLE MAINLY FOR OUR NORTHERN ZONES INTO TUESDAY. WEDNESDAY SHOULD
REMAIN CHILLY AND DRY...THOUGH A LITTLE WARMER THAN THE PAST COUPLE
DAYS AS OUR AIR MASS SLOWLY MODERATES. THE NEXT SYSTEM LOOKS
STRONGER...AND MAY ENCOUNTER A STUBBORN LOW-LEVEL COLD AIR MASS AS
PRECIPITATION SPREADS ONSHORE. THIS MAY RESULT IN MORE FROZEN OR
FREEZING PRECIPITATION BEFORE A PACIFIC AIR MASS FINALLY TAKES OVER
LATE IN THE WEEK.
&&
.UPDATE...UPDATED HEADLINES BELOW. CONFIDENCE WAS NOT HIGH ENOUGH TO
PUSH BACK THE ADVISORY FOR THE METRO AREA TO AFTER THE EVENING COMMUTE AS
GUIDANCE IS STILL MIXED...SO FOR NOW KEPT THE 4 PM START TIME.
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...
ONE LAST BITTERLY COLD NIGHT OUT THERE TONIGHT BEFORE THE SLOW
PROGRESSION OUT OF THE COLDSNAP BEGINS. SEEING SOME OF THAT WITH THE
COAST REMAINING GENERAALLY IN THE 20S. IT IS A BALMY 3 DEGREES IN
EUGENE AND PLENTY OF TEENS INLAND. TEMPS AND DEWPOINTS ARE UP A
LITTLE FROM LAST NIGHT WHICH SHOULD PREVENT WIDESPREAD SINGLE
DIGITS.
LOWER CLOUDS ARE ROLLING INTO THE COAST THIS MORNING...AND KLGX RADAR
DEPICTS SOME SHOWER ACTIVITY OFFSHORE THAT IS SOMEWHAT DYING OUT ON
THE LEADING EDGE. LATEST HI-RES GUIDANCE SUGGESTS THAT NOT A WHOLE
LOT OF INLAND PROGRESS THIS MORNING AS THE FLOW IS STILL MORE
NORTHERLY ALOFT...BUT LIKELY SOME LIGHT SNOW OR FLURRIES FOR THE S
WA/N OR COAST AND COAST RANGE.
A SOMEWHAT CHALLENGING FORECAST COMING UP THE NEXT FEW DAYS AFTER THE
NEAR TERM AS SEVERAL WEAK WAVES MOVE THROUGH BUT MIXED SIGNALS WITH
REGARDS TO PRECIPITATION. COULD SEE SOME VERY LIGHT SNOW/FLURRIES OR
SOME FREEZING DRIZZLE.AFTER THIS MORNING SEVERAL MODELS BRING LIGHT
PRECIPITATION (0.02" QPF OR LESS) INTO THE INTERIOR THIS AFTERNOON.
CURRENT KLGX DATA WOULD SUGGEST THAT PRECIPITATION WILL CONTINUE
WORKING INLAND...BUT MAY HAVE PROBLEMS WITH THE DRY AIR MASS.
MEANWHILE THE HRRR AND NAM KEEP PRECIPITATION CONFINED TO COAST AND
COAST RANGE WHERE TEMPERATURE PROFILES BEGIN TO WARM GIVEN THE WEAK
ONSHORE FLOW TO THE POINT WHERE PRECIP TYPE WOULD CHANGE TO RAIN OR
MAYBE RAIN-SNOW MIX. MEANWHILE INLAND THE PROFILE WILL REMAIN ALL
BELOW FREEZING. AFTER THAT THERE IS A MORE DISTINCT WAVE OFF THE
COAST OF NORTHERN B.C. THAT WILL DROP S.E. AND PROVIDE A BIT MORE
ORGANIZED LIFT TONIGHT INTO EARLY TUESDAY.
THE MOISTURE LAYER LOOKS TO BE RATHER SHALLOW. THESE SITUATIONS TEND
TO FAVOR FREEZING DRIZZLE...BUT ONLY IF YOU TAKE THEM FOR FACE VALUE
AND DO NOT CONSIDER THE INITIAL AIRMASS THAT THE CLOUD FORMED IN OR
THE AIRMASS THE SATURATED CLOUD IS MOVING INTO. SOUNDINGS SUGGEST THE
TOP OF THE MOIST LAYER AROUND -5 TO -7C. IT IS INCORRECT TO SUGGEST
THAT THERE WILL BE NO ICE CRYSTALS PRESENT IN THE CLOUD EVEN AT THESE
TEMPERATURES...JUST A QUESTION OF IF THERE ARE ENOUGH. CANNOT IGNORE
THE FACT THERE MAY ALSO BE SOME FREEZING DRIZZLE WHICH IF HITTING THE
COLD ROADS WOULD FREEZE LIKE THE SNOW DID THE OTHER DAY. THAT
SAID...AN INVESTIGATION OF DUAL-POLARIZATION DATA FROM KLGX AND
SIMPLY DUE TO THE FACT THAT REFLECTIVITY RETURNS ARE AS HIGH AS 30-40
DBZ SUGGEST THAT P-TYPE...AT LEAST CURRENTLY AND WITH THE FIRST BATCH
COMING IN IS SNOW AND NOT FREEZING DRIZZLE. THE 0Z QUILLAYUTE
SOUNDING DOES SUGGEST A WARM LAYER ABOVE THE MOIST LAYER..
BUT THE POTENTIAL OF FREEZING DRIZZLE CANNOT BE IGNORED AS THE LOWER
LEVEL PROFILE WARMS AND REDUCES ICE CRYSTAL AVAILABILITY ESPECIALLY
TOWARDS TUESDAY. AND ANY ACCUMULATING FREEZING DRIZZLE WOULD WARRANT
AN ADVISORY...ALSO DUE TO THE FACT DEWPOINTS WILL BE MUCH HIGHER
MONDAY NIGHT INTO TUESDAY MORNING...ROADS HAVE THE POTENTIAL TO BE
QUITE HAZARDOUS...REGARDLESS OF THE PRECIP TYPE OR HOW MUCH/HOW
LITTLE SNOW ACTUALLY FALLS. SREF PLUMES KEEP ANYWHERE FROM LIGHT SNOW
ACCUMS TO UP TO AN INCH IN THE METRO. MODELS CONTINUE TO FAVOR THE
KELSO/CASTLE ROCK AREA AND THE I-5 CORRIDOR IN WASHINGTON FOR THE
MOST QPF. THEREFORE SEE NO REASON AT LEAST AT THIS TIME TO CHANGE THE
HEADLINE...BUT WILL FOCUS ON FREEZING DRIZZLE/SNOW POTENTIAL AND ROAD
IMPACTS. SINCE THE CENTRAL VALLEY DOES NOT LOOK TO SEE MUCH SNOW...I
CAN FORESEE A SITUATION WHERE IF FREEZING DRIZZLE DOMINATES AND THE
PRECIP GETS A BIT FARTHER SOUTH...THAT AN ADVISORY WOULD BE
WARRANTED...BUT CONFIDENCE IS LOW. DO STILL THINK THAT 1-2" ARE
POSSIBLE IF THE P-TYPE REMAINS SNOW MAINLY NORTH OF THE COLUMBIA
RIVER AND ALSO TOWARDS ST HELENS/SCAPPOOSE. I HOPE THIS DOES NOT
COME BACK TO HAUNT ME...BUT AM CONTEMPLATING TO REMOVING THE CENTRAL
WILLAMETTE VALLEY FROM THE WINTER WX ADVISORY...AS QPF IN THESE
AREAS DOES NOT SUPPORT AT THAT MUCH IN THE WAY OF SNOW. IF FREEZING
DRIZZLE IS THE MORE DOMINANT P-TYPE...THAN AN ADVISORY WOULD THEN BE
WARRANTED. WILL WORK UP THE WSW HERE WITH REFINED TIMING AND
FINAL DECISIONS SHORTLY AND SEND AN AMENDED AFD WITH THE HEADLINES.
THE MAIN JET ENERGY COMING OUT OF WESTERN CANADA SHOULD SHIFT FARTHER
EAST BY WEDNESDAY...ALLOWING SOME CLEARING AND POSSIBLY ANOTHER CLEAR
CALM AND CHILLY MORNING FOR SOME AREAS WED MORNING. EXPECT THERE TO
THEN BE FOG/FREEZING FOG. AFTER BURN OFF AND WITH SOME
SUNSHINE AND A SOMEWHAT MODERATED AIR MASS...MOST AREAS SHOULD BE
ABLE TO GET ABOVE FREEZING WEDNESDAY. HAVE DRIED OUT THE FORECAST
FOR WEDS AND WEDNESDAY NIGHT WITH THE EXPECTED TREND OF BACKING OFF
THE ARRIVAL OF THE PACIFIC SYSTEM WITH A COLD AND STRONG UPPER RIDGE
IN PLACE. /KMD
LEFT PREVIOUS DISCUSSION IN PLACE FOR THE LATTER PART OF THE SHORT
TERM FROM THE EVENING SHIFT AS MUCH OF THIS SHIFT WAS SPENT FINE
TUNING THE DETAILS THROUGH WEDNESDAY NIGHT.... NO DOUBT THIS IS AN
HISTORIC COLD AIR MASS. WHICH BRINGS US TO OUR NEXT FORECAST
CHALLENGE...THE PRECIPITATION TYPE EXPECTED FROM OUR NEXT EVENT.
CONSIDERING THE MAGNITUDE OF COLD ASSOCIATED WITH THIS AIR MASS...IT
IS VERY HARD TO BELIEVE WEAK CLIPPER SYSTEMS WILL BE SUFFICIENT TO
ERODE THE COLD AIR ENTRENCHED OVER THE PACIFIC NORTHWEST. WE CONTINUE
TO DISAGREE WITH MODEL GUIDANCE THAT SUGGESTS THE COLD AIR WILL SCOUR
OUT QUICKLY...AND OUR TEMPERATURE AND PRECIPITATION TYPE FORECAST
REFLECTS THAT ALL THE WAY INTO THURSDAY. WEAGLE
.LONG TERM...NO CHANGES TO THE GRIDS OTHER THAN TO BACK OFF ON
POPS A BIT TO START THURSDAY SO REST OF THE DISCUSSION REMAINS
UNCHANGED...WILL LET THE DAY SHIFT REVISIT THE CHANGE IN TIMING AND
IMPACTS ON THERMAL PROFILES...WEDNESDAY NIGHT THROUGH
SUNDAY...OVERALL NO CHANGES TO THE THINKING BEHIND THE EXTENDED
FORECAST. DID SOME MANIPULATION OF THE GRIDS TO ATTEMPT TO BETTER
EXPRESS THE MIXED PRECIPITATION POTENTIAL WITH THE LATE WEEK SYSTEM.
WEAGLE
PREVIOUS DISCUSSION FOLLOWS...THE WELL ESTABLISHED COLD ARCTIC AIR
MASS WILL BEGIN TO MODERATE AS FLOW ALOFT BECOMES MORE WESTERLY.
TEMPERATURES LOOK TO TREND BACK TO SEASONAL NORMALS THROUGH THE
SECOND HALF OF NEXT WEEK. THE 12Z GFS AND ECMWF ARE A BIT SLOWER TO
BRING A SYSTEM ONSHORE EARLY THURSDAY SO HAVE ADJUSTED POP GRIDS TO
REFLECT THIS. FORECAST MODELS BRING THE HEAVIEST PRECIP ONSHORE
MIDDAY THURSDAY...WITH THE GFS SOLUTION ABOUT 6 HOURS FASTER. THERE
REMAINS SOME CONCERN THAT THE MODELS ARE TOO QUICK TO WARM THE AIR
MASS AFTER THIS PERIOD OF RECORD-SETTING COLD...SO IT IS POSSIBLE
THAT THIS PRECIPITATION MAY BEGIN IN THE FORM OF SNOW OR FREEZING
RAIN. THIS IS PARTICULARLY THE CASE FOR UPPER HOOD RIVER...THE
COLUMBIA RIVER GORGE..AND THE NORTHERN WILLAMETTE VALLEY. OTHERWISE
RAIN AND CASCADE SNOW IS EXPECTED TO CONTINUE THROUGH FRIDAY NIGHT.
THERE MAY BE A BRIEF DRY PERIOD AT LEAST PART OF THE DAY SATURDAY AS
LOW LEVEL FLOW WILL TURN SOUTHERLY BEFORE THE THE NEXT SYSTEM
ARRIVES SATURDAY AFTERNOON OR EVENING BRINGING RAIN ACROSS THE
FORECAST AREA.CULLEN
&&
.AVIATION...VFR CONDITIONS THIS AM...WITH POCKETS OF FOG IN S
WILLAMETTE VALLEY. CLOUDS INCREASING ALONG OREGON COAST...AND
SHOULD PERSIST THROUGH TUE AM. FLURRIES ON THE COAST THIS AM.
CIGS ON S WASH/N ORE COAST WILL LOWER TO MVFR AFTER 16Z...WITH
OCCASIONAL MVFR VIS WITH BURSTS OF SNOW. NOT MUCH CHANGE ON COAST
FOR TONIGHT...BUT INLAND CIGS WILL DROP TO LOW VFR OR MVFR WITH
MVFR VIS IN OCCASIONAL LIGHT SNOW ACROSS N TAF SITES.
KPDX AND APPROACHES...VFR WITH LIGHT EAST WINDS CONTINUE. WILL
HAVE INCREASING LOW VFR CLOUDS THIS AM...WITH SOME OCCASIONAL
FLURRIES FROM 20Z THROUGH 06Z TUE. CIGS WILL LOWER TO MVFR AFTER
03Z...WITH INCREASING THREAT OF SNOW LATE OVERNIGHT INTO TUE AM.
ROCKEY.
.MARINE...BENIGN WEATHER THROUGH WED. HIGH PRES OVER PAC NW
MAINTAINS LIGHT OFFSHORE FLOW THROUGH WED. WILL WILL TURN MORE W
TO SW TUE AND WED AS HIGH WEAKENS AND LOWER PRES APPROACHES FROM
THE W. SEAS HOLDING AT 2 TO 4 FT TODAY AND TUE...THEN BUILD
SLIGHTLY LATER TUE AND WED.
STRONG COLD FRONT WILL ARRIVE ON THU...WITH S GALES EXPECTED.
SEAS WILL BUILD BACK CLOSER TO 10 FT.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WEATHER WEATHER ADVISORY...
1 PM TODAY TO 1 PM TUE FOR LOWER COLUMBIA.
4 PM TODAY TO 1 PM TUE FOR NORTH WILLAMETTE VALLEY
INCLUDING THE GREATER PORTLAND METRO AREA.
WA...WINTER WEATHER ADVISORY...
7 AM TO 10 PM TODAY FOR SOUTH WASHINGTON COAST.
1 PM TODAY TO 1 PM TUE FOR I-5 CORRIDOR IN COWLITZ CTY.
4 PM TODAY TO 1 PM TUE FOR GREATER VANCOUVER AREA
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS PORTLAND OR
320 AM PST MON DEC 9 2013
.SYNOPSIS...ANOTHER VERY COLD NIGHT AS ARCTIC HIGH PRESSURE REMAINS
DOMINANT OVER THE PACIFIC NORTHWEST. LOWER PRESSURE OFFSHORE
CONTINUES TO DRIVE WEAK EASTERLY FLOW THROUGH THE COLUMBIA GORGE AND
INTO THE PORTLAND AREA. A WEAK CLIPPER SYSTEM WILL PUSH DOWN FROM
THE YUKON LATER TODAY...BRINGING A CHANCE OF SNOW AND OR FREEZING
DRIZZLE MAINLY FOR OUR NORTHERN ZONES INTO TUESDAY. WEDNESDAY SHOULD
REMAIN CHILLY AND DRY...THOUGH A LITTLE WARMER THAN THE PAST COUPLE
DAYS AS OUR AIR MASS SLOWLY MODERATES. THE NEXT SYSTEM LOOKS
STRONGER...AND MAY ENCOUNTER A STUBBORN LOW-LEVEL COLD AIR MASS AS
PRECIPITATION SPREADS ONSHORE. THIS MAY RESULT IN MORE FROZEN OR
FREEZING PRECIPITATION BEFORE A PACIFIC AIR MASS FINALLY TAKES OVER
LATE IN THE WEEK.
&&
.SHORT TERM...TONIGHT THROUGH WEDNESDAY...
ONE LAST BITTERLY COLD NIGHT OUT THERE TONIGHT BEFORE THE SLOW
PROGRESSION OUT OF THE COLDSNAP BEGINS. SEEING SOME OF THAT WITH THE
COAST REMAINING GENERAALLY IN THE 20S. IT IS A BALMY 3 DEGREES IN
EUGENE AND PLENTY OF TEENS INLAND. TEMPS AND DEWPOINTS ARE UP A
LITTLE FROM LAST NIGHT WHICH SHOULD PREVENT WIDESPREAD SINGLE
DIGITS.
LOWER CLOUDS ARE ROLLING INTO THE COAST THIS MORNING...AND KLGX RADAR
DEPICTS SOME SHOWER ACTIVITY OFFSHORE THAT IS SOMEWHAT DYING OUT ON
THE LEADING EDGE. LATEST HI-RES GUIDANCE SUGGESTS THAT NOT A WHOLE
LOT OF INLAND PROGRESS THIS MORNING AS THE FLOW IS STILL MORE
NORTHERLY ALOFT...BUT LIKELY SOME LIGHT SNOW OR FLURRIES FOR THE S
WA/N OR COAST AND COAST RANGE.
A SOMEWHAT CHALLENGING FORECAST COMING UP THE NEXT FEW DAYS AFTER THE
NEAR TERM AS SEVERAL WEAK WAVES MOVE THROUGH BUT MIXED SIGNALS WITH
REGARDS TO PRECIPITATION. COULD SEE SOME VERY LIGHT SNOW/FLURRIES OR
SOME FREEZING DRIZZLE.AFTER THIS MORNING SEVERAL MODELS BRING LIGHT
PRECIPITATION (0.02" QPF OR LESS) INTO THE INTERIOR THIS AFTERNOON.
CURRENT KLGX DATA WOULD SUGGEST THAT PRECIPITATION WILL CONTINUE
WORKING INLAND...BUT MAY HAVE PROBLEMS WITH THE DRY AIR MASS.
MEANWHILE THE HRRR AND NAM KEEP PRECIPITATION CONFINED TO COAST AND
COAST RANGE WHERE TEMPERATURE PROFILES BEGIN TO WARM GIVEN THE WEAK
ONSHORE FLOW TO THE POINT WHERE PRECIP TYPE WOULD CHANGE TO RAIN OR
MAYBE RAIN-SNOW MIX. MEANWHILE INLAND THE PROFILE WILL REMAIN ALL
BELOW FREEZING. AFTER THAT THERE IS A MORE DISTINCT WAVE OFF THE
COAST OF NORTHERN B.C. THAT WILL DROP S.E. AND PROVIDE A BIT MORE
ORGANIZED LIFT TONIGHT INTO EARLY TUESDAY.
THE MOISTURE LAYER LOOKS TO BE RATHER SHALLOW. THESE SITUATIONS TEND
TO FAVOR FREEZING DRIZZLE...BUT ONLY IF YOU TAKE THEM FOR FACE VALUE
AND DO NOT CONSIDER THE INITIAL AIRMASS THAT THE CLOUD FORMED IN OR
THE AIRMASS THE SATURATED CLOUD IS MOVING INTO. SOUNDINGS SUGGEST THE
TOP OF THE MOIST LAYER AROUND -5 TO -7C. IT IS INCORRECT TO SUGGEST
THAT THERE WILL BE NO ICE CRYSTALS PRESENT IN THE CLOUD EVEN AT THESE
TEMPERATURES...JUST A QUESTION OF IF THERE ARE ENOUGH. CANNOT IGNORE
THE FACT THERE MAY ALSO BE SOME FREEZING DRIZZLE WHICH IF HITTING THE
COLD ROADS WOULD FREEZE LIKE THE SNOW DID THE OTHER DAY. THAT
SAID...AN INVESTIGATION OF DUAL-POLARIZATION DATA FROM KLGX AND
SIMPLY DUE TO THE FACT THAT REFLECTIVITY RETURNS ARE AS HIGH AS 30-40
DBZ SUGGEST THAT P-TYPE...AT LEAST CURRENTLY AND WITH THE FIRST BATCH
COMING IN IS SNOW AND NOT FREEZING DRIZZLE. THE 0Z QUILLAYUTE
SOUNDING DOES SUGGEST A WARM LAYER ABOVE THE MOIST LAYER..
BUT THE POTENTIAL OF FREEZING DRIZZLE CANNOT BE IGNORED AS THE LOWER
LEVEL PROFILE WARMS AND REDUCES ICE CRYSTAL AVAILABILITY ESPECIALLY
TOWARDS TUESDAY. AND ANY ACCUMULATING FREEZING DRIZZLE WOULD WARRANT
AN ADVISORY...ALSO DUE TO THE FACT DEWPOINTS WILL BE MUCH HIGHER
MONDAY NIGHT INTO TUESDAY MORNING...ROADS HAVE THE POTENTIAL TO BE
QUITE HAZARDOUS...REGARDLESS OF THE PRECIP TYPE OR HOW MUCH/HOW
LITTLE SNOW ACTUALLY FALLS. SREF PLUMES KEEP ANYWHERE FROM LIGHT SNOW
ACCUMS TO UP TO AN INCH IN THE METRO. MODELS CONTINUE TO FAVOR THE
KELSO/CASTLE ROCK AREA AND THE I-5 CORRIDOR IN WASHINGTON FOR THE
MOST QPF. THEREFORE SEE NO REASON AT LEAST AT THIS TIME TO CHANGE THE
HEADLINE...BUT WILL FOCUS ON FREEZING DRIZZLE/SNOW POTENTIAL AND ROAD
IMPACTS. SINCE THE CENTRAL VALLEY DOES NOT LOOK TO SEE MUCH SNOW...I
CAN FORESEE A SITUATION WHERE IF FREEZING DRIZZLE DOMINATES AND THE
PRECIP GETS A BIT FARTHER SOUTH...THAT AN ADVISORY WOULD BE
WARRANTED...BUT CONFIDENCE IS LOW. DO STILL THINK THAT 1-2" ARE
POSSIBLE IF THE P-TYPE REMAINS SNOW MAINLY NORTH OF THE COLUMBIA
RIVER AND ALSO TOWARDS ST HELENS/SCAPPOOSE. I HOPE THIS DOES NOT
COME BACK TO HAUNT ME...BUT AM CONTEMPLATING TO REMOVING THE CENTRAL
WILLAMETTE VALLEY FROM THE WINTER WX ADVISORY...AS QPF IN THESE
AREAS DOES NOT SUPPORT AT THAT MUCH IN THE WAY OF SNOW. IF FREEZING
DRIZZLE IS THE MORE DOMINANT P-TYPE...THAN AN ADVISORY WOULD THEN BE
WARRANTED. WILL WORK UP THE WSW HERE WITH REFINED TIMING AND
FINAL DECISIONS SHORTLY AND SEND AN AMENDED AFD WITH THE HEADLINES.
THE MAIN JET ENERGY COMING OUT OF WESTERN CANADA SHOULD SHIFT FARTHER
EAST BY WEDNESDAY...ALLOWING SOME CLEARING AND POSSIBLY ANOTHER CLEAR
CALM AND CHILLY MORNING FOR SOME AREAS WED MORNING. EXPECT THERE TO
THEN BE FOG/FREEZING FOG. AFTER BURN OFF AND WITH SOME
SUNSHINE AND A SOMEWHAT MODERATED AIR MASS...MOST AREAS SHOULD BE
ABLE TO GET ABOVE FREEZING WEDNESDAY. HAVE DRIED OUT THE FORECAST
FOR WEDS AND WEDNESDAY NIGHT WITH THE EXPECTED TREND OF BACKING OFF
THE ARRIVAL OF THE PACIFIC SYSTEM WITH A COLD AND STRONG UPPER RIDGE
IN PLACE. /KMD
LEFT PREVIOUS DISCUSSION IN PLACE FOR THE LATTER PART OF THE SHORT
TERM FROM THE EVENING SHIFT AS MUCH OF THIS SHIFT WAS SPENT FINE
TUNING THE DETAILS THROUGH WEDNESDAY NIGHT.... NO DOUBT THIS IS AN
HISTORIC COLD AIR MASS. WHICH BRINGS US TO OUR NEXT FORECAST
CHALLENGE...THE PRECIPITATION TYPE EXPECTED FROM OUR NEXT EVENT.
CONSIDERING THE MAGNITUDE OF COLD ASSOCIATED WITH THIS AIR MASS...IT
IS VERY HARD TO BELIEVE WEAK CLIPPER SYSTEMS WILL BE SUFFICIENT TO
ERODE THE COLD AIR ENTRENCHED OVER THE PACIFIC NORTHWEST. WE CONTINUE
TO DISAGREE WITH MODEL GUIDANCE THAT SUGGESTS THE COLD AIR WILL SCOUR
OUT QUICKLY...AND OUR TEMPERATURE AND PRECIPITATION TYPE FORECAST
REFLECTS THAT ALL THE WAY INTO THURSDAY. WEAGLE
.LONG TERM...NO CHANGES TO THE GRIDS OTHER THAN TO BACK OFF ON
POPS A BIT TO START THURSDAY SO REST OF THE DISCUSSION REMAINS
UNCHANGED...WILL LET THE DAY SHIFT REVISIT THE CHANGE IN TIMING AND
IMPACTS ON THERMAL PROFILES...WEDNESDAY NIGHT THROUGH
SUNDAY...OVERALL NO CHANGES TO THE THINKING BEHIND THE EXTENDED
FORECAST. DID SOME MANIPULATION OF THE GRIDS TO ATTEMPT TO BETTER
EXPRESS THE MIXED PRECIPITATION POTENTIAL WITH THE LATE WEEK SYSTEM.
WEAGLE
PREVIOUS DISCUSSION FOLLOWS...THE WELL ESTABLISHED COLD ARCTIC AIR
MASS WILL BEGIN TO MODERATE AS FLOW ALOFT BECOMES MORE WESTERLY.
TEMPERATURES LOOK TO TREND BACK TO SEASONAL NORMALS THROUGH THE
SECOND HALF OF NEXT WEEK. THE 12Z GFS AND ECMWF ARE A BIT SLOWER TO
BRING A SYSTEM ONSHORE EARLY THURSDAY SO HAVE ADJUSTED POP GRIDS TO
REFLECT THIS. FORECAST MODELS BRING THE HEAVIEST PRECIP ONSHORE
MIDDAY THURSDAY...WITH THE GFS SOLUTION ABOUT 6 HOURS FASTER. THERE
REMAINS SOME CONCERN THAT THE MODELS ARE TOO QUICK TO WARM THE AIR
MASS AFTER THIS PERIOD OF RECORD-SETTING COLD...SO IT IS POSSIBLE
THAT THIS PRECIPITATION MAY BEGIN IN THE FORM OF SNOW OR FREEZING
RAIN. THIS IS PARTICULARLY THE CASE FOR UPPER HOOD RIVER...THE
COLUMBIA RIVER GORGE..AND THE NORTHERN WILLAMETTE VALLEY. OTHERWISE
RAIN AND CASCADE SNOW IS EXPECTED TO CONTINUE THROUGH FRIDAY NIGHT.
THERE MAY BE A BRIEF DRY PERIOD AT LEAST PART OF THE DAY SATURDAY AS
LOW LEVEL FLOW WILL TURN SOUTHERLY BEFORE THE THE NEXT SYSTEM
ARRIVES SATURDAY AFTERNOON OR EVENING BRINGING RAIN ACROSS THE
FORECAST AREA.CULLEN
&&
.AVIATION...VFR CONDITIONS THIS AM...WITH POCKETS OF FOG IN S
WILLAMETTE VALLEY. CLOUDS INCREASING ALONG OREGON COAST...AND
SHOULD PERSIST THROUGH TUE AM. FLURRIES ON THE COAST THIS AM.
CIGS ON S WASH/N ORE COAST WILL LOWER TO MVFR AFTER 16Z...WITH
OCCASIONAL MVFR VIS WITH BURSTS OF SNOW. NOT MUCH CHANGE ON COAST
FOR TONIGHT...BUT INLAND CIGS WILL DROP TO LOW VFR OR MVFR WITH
MVFR VIS IN OCCASIONAL LIGHT SNOW ACROSS N TAF SITES.
KPDX AND APPROACHES...VFR WITH LIGHT EAST WINDS CONTINUE. WILL
HAVE INCREASING LOW VFR CLOUDS THIS AM...WITH SOME OCCASIONAL
FLURRIES FROM 20Z THROUGH 06Z TUE. CIGS WILL LOWER TO MVFR AFTER
03Z...WITH INCREASING THREAT OF SNOW LATE OVERNIGHT INTO TUE AM.
ROCKEY.
.MARINE...BENIGN WEATHER THROUGH WED. HIGH PRES OVER PAC NW
MAINTAINS LIGHT OFFSHORE FLOW THROUGH WED. WILL WILL TURN MORE W
TO SW TUE AND WED AS HIGH WEAKENS AND LOWER PRES APPROACHES FROM
THE W. SEAS HOLDING AT 2 TO 4 FT TODAY AND TUE...THEN BUILD
SLIGHTLY LATER TUE AND WED.
STRONG COLD FRONT WILL ARRIVE ON THU...WITH S GALES EXPECTED.
SEAS WILL BUILD BACK CLOSER TO 10 FT.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WEATHER WEATHER ADVISORY...
10 AM TODAY TO 10 AM TUE FOR LOWER COLUMBIA.
4 PM TODAY TO 4 PM TUE FOR NORTH WILLAMETTE VALLEY
INCLUDING THE GREATER PORTLAND METRO AREA.
4 PM TODAY TO 4 PM TUE FOR CENTRAL WILLAMETTE VALLEY.
WA...WINTER WEATHER ADVISORY...
7 AM TO 10 PM TODAY FOR SOUTH WASHINGTON COAST.
10 AM TODAY TO 10 AM TUE FOR I-5 CORRIDOR IN COWLITZ CTY.
4 PM TODAY TO 4 PM TUE FOR GREATER VANCOUVER AREA
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION...UPDATED
NWS MIDLAND/ODESSA TX
912 AM CST Mon Dec 9 2013
.DISCUSSION...
Have opted to issue a freezing fog advisory for most of the Basin
including Lea County until 18z. Vsbys are being reported as low as
1/8 mile here at MAF and 1/4 mile at Andrews. Also, flurries are
being reported in Midland/Greenwood/Snyder and have mentioned that in
fcst too.
&&
.PREV DISCUSSION... /ISSUED 734 AM CST Mon Dec 9 2013/
UPDATE...
Have sent an update to include mention of Freezing fog across most
of the PB and Lea Co.
DISCUSSION...
Cold air is pushing swd and areas of freezing fog are developing in
the colder air. Big Spring and Snyder are down to 3/4 to 1 1/4 miles
visibility. NAM12 is a little too cool and RUC13 a little too warm
looking at dwpnts upstream IT will still take a few hrs for dwpnts
to decrease and thus fog expected to hang around thru at least mid
morning. Very light ice accumulations possible.
PREV DISCUSSION... /ISSUED 506 AM CST Mon Dec 9 2013/
DISCUSSION...
See aviation discussion below.
AVIATION...
Cold front currently moving southwest through the northern Permian
Basin. Expecting prevailing to tempo MVFR to IFR conditions behind
this front today. A period of VFR conditions is possible this afternoon
at the terminals before MVFR and or IFR conditions return early
this evening and continuing overnight. Generally northeast winds
of 5 to 15 mph are expected through this evening.
12
PREV DISCUSSION... /ISSUED 355 AM CST Mon Dec 9 2013/
DISCUSSION...
Another cold front is moving through the area early this morning
bringing a resurgence of very cold air. We are not seeing any
freezing fog so far either ahead of or behind the front, and
despite mostly clear skies and low T/Td depressions, concern is
dropping for a serious freezing fog threat. It is still possible
for some patchy freezing fog to form especially near the leading
edge of the front with the fog threat diminishing farther behind
the front as drier air filters south. The small T/Td depressions
could allow for some ice condensation to occur on exposed surfaces
despite the lack of fog creating slick spots on local roads.
Models have backed off snow chances in SE NM today and tonight
likely due to limited moisture and a very positively tilted weak
upper trough so have removed PoPs.
We then see slightly warmer temps Tuesday and Wednesday before a
weak front arrives Thursday. A more zonal upper air pattern will
limit the amount of cold air. Shortly following this front will be
an upper level low moving out of the southwestern states. This low
will be weakening as it approaches the area and may even be an
open trough by the time it arrives over west Texas, but there
should be enough moisture and instability for precipitation to
develop Thursday. The amount and extent of precipitation will
depend greatly on the strength of the upper low...the stronger the
low the more likely it is the precip will spread farther west...a
weak low or trough will push moisture and most precip to the
eastern CWA. For now the consensus seems to be that it will be an
open trough and thus will keep precip chances to the eastern
counties. Temperatures at this time indicate the p-type would be
rain so there may not be any travel worries this time. Friday gets
warmer before yet another front arrives Saturday.
Hennig
&&
.PRELIMINARY POINT TEMPS/POPS...
ANDREWS TX 29 18 43 25 / 10 10 0 0
BIG SPRING TX 28 18 44 26 / 10 10 0 0
CARLSBAD NM 42 25 48 27 / 10 10 0 0
DRYDEN TX 51 27 49 30 / 0 0 0 0
FORT STOCKTON TX 46 22 50 29 / 0 10 0 0
GUADALUPE PASS TX 44 22 44 28 / 10 10 0 0
HOBBS NM 32 17 45 24 / 10 10 0 0
MARFA TX 53 22 50 26 / 0 10 0 0
MIDLAND INTL AIRPORT TX 32 18 44 25 / 10 10 0 0
ODESSA TX 32 19 45 26 / 10 10 0 0
WINK TX 39 22 47 25 / 10 10 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...FREEZING FOG ADVISORY until 11 AM MST this morning FOR THE
FOLLOWING ZONES... Central Lea County...Northern Lea
County...Southern Lea County.
TX...FREEZING FOG ADVISORY until Noon CST today FOR THE FOLLOWING
ZONES... Andrews...Borden...Dawson...Ector...Gaines...
Glasscock...Howard...Martin...Midland...Mitchell...Scurry...
Winkler.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
753 AM CST MON DEC 9 2013
.UPDATE...
Expanded the Freezing Fog Advisory another row of counties.
&&
.DISCUSSION...
The fog continues to expand into the Concho Valley, so I have
expanded the Freezing Fog Advisory to include Irion, Tom Green,
Concho, Menard, and Schleicher counties. We will continue to monitor
to progress of the fog.
&&
.PREV DISCUSSION... /ISSUED 554 AM CST MON DEC 9 2013/
UPDATE...
To expand the Freezing Fog Advisory...
DISCUSSION...
Areas of freezing fog across the Big Country, Heartland and
Northwest Hill country continue to expand to the south and west.
Temperatures are below freezing across the entire area and given
the expansion of the fog, I went ahead and expanded the advisory
to include all of the Big Country and the northern Concho Valley.
The freezing fog could approach areas farther south in the next
few hours, including San Angelo, so I will continue to monitor
trends and these counties may need to eventually be added.
Otherwise, the rest of the forecast looks on track.
Please see the aviation discussion below...
AVIATION...
Stratus/fog continues to expand through much of West Central Texas
this morning resulting in IFR to LIFR conditions. KSOA is a bit
more tricky, as the stratus to the south is struggling to expand
northward. For now, I have indicated MVFR ceilings by 14z, and
will continue to monitor. Some improvement in ceilings is forecast
by late morning or early afternoon, with MVFR ceilings returning
to most sites. Winds today will be from the north at 5 to 10 knots
PREV DISCUSSION... /ISSUED 356 AM CST MON DEC 9 2013/
SHORT TERM...
Today and Tonight
A cold front is currently moving through the Big Country and
should be approaching the Interstate 10 corridor shortly after
sunrise. Winds behind the front will become north and increase to
about 8 to 12 mph, with colder air slowly filtering into West
Central Texas. In addition, areas of freezing fog are evident just
to the east of our area, which has slowly been creeping west. I
expect this freezing fog to expand to a Throckmorton, to Coleman,
to Mason line in the next few hours. A freezing fog advisory is in
effect for parts of the Heartland through 9 AM, and I will
continue to monitor trends for the possibility of expanding it
north into parts of the Big Country and south toward Mason county.
The HRRR is also indicating some post frontal fog across parts of
the Big Country, which will need to be monitored. Stratus should
fill in this morning behind the front, with much of the area
becoming overcast by mid morning. Given the expected cloud cover
and cold air advection, I lowered high temperatures slightly.
Highs will range from the upper 20s north of Interstate 20, to the
mid 40s across the Interstate 10 corridor.
Cloudy skies through much of the overnight period will not
support ideal radiational cooling conditions, but given the cold
airmass that will be filtering into the region, I went ahead and
lowered low temperatures slightly. Tuesday morning low
temperatures will generally be in the teens to lower 20s across
all of West Central Texas.
Daniels
LONG TERM...
Tuesday through Sunday
As a fast moving shortwave trough moves through the Great Lakes
region Tuesday night into Wednesday, a cold front will move into
Texas, causing another brief cooling for Wednesday into Thursday.
However, no precipitation is expected with the front. Lee
troughing on Thursday will allow winds to quickly turn back to the
south in our area, allowing temperatures to warm back up across
the area Thursday and especially Friday. An upper level low
initially off the coast of California on Monday will move across
the Desert Southwest and into the Texas panhandle by Friday. As
this low approaches, weak shortwaves will move across the area out
ahead of it, interacting with moisture return and low level warm
air advection, resulting in at least a slight chance for showers
mainly Thursday afternoon and Thursday night, with some lingering
showers moving out of the area on Friday.
The upper level low will then move east towards the Mississippi
Valley by Saturday, sending a cold front into the area. And while
the cold front will slow the warming trend, the air mass behind
the front will not be of arctic origin, so while we have gone
cooler than the MOS guidance for Saturday and Sunday, temperatures
should continue to trend closer to normal values through the
weekend.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 26 18 39 27 42 / 10 5 0 0 0
San Angelo 35 19 44 26 46 / 10 5 0 0 0
Junction 46 22 47 24 52 / 10 10 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY until 10 AM CST this morning FOR THE
FOLLOWING ZONES: Brown...Callahan...Coke...Coleman...Concho...
Fisher...Haskell...Irion...Jones...Kimble...Mason...McCulloch...
Menard...Nolan...Runnels...San Saba...Schleicher...Shackelford...
Sterling...Taylor...Throckmorton...Tom Green.
&&
$$
Reimer
AREA FORECAST DISCUSSION...UPDATE
NWS MIDLAND/ODESSA TX
734 AM CST Mon Dec 9 2013
.UPDATE...
Have sent an update to include mention of Freezing fog across most
of the PB and Lea Co.
&&
.DISCUSSION...
Cold air is pushing swd and areas of freezing fog are developing in
the colder air. Big Spring and Snyder are down to 3/4 to 1 1/4 miles
visibility. NAM12 is a little too cool and RUC13 a little too warm
looking at dwpnts upstream IT will still take a few hrs for dwpnts
to decrease and thus fog expected to hang around thru at least mid
morning. Very light ice accumulations possible.
&&
.PREV DISCUSSION... /ISSUED 506 AM CST Mon Dec 9 2013/
DISCUSSION...
See aviation discussion below.
AVIATION...
Cold front currently moving southwest through the northern Permian
Basin. Expecting prevailing to tempo MVFR to IFR conditions behind
this front today. A period of VFR conditions is possible this afternoon
at the terminals before MVFR and or IFR conditions return early
this evening and continuing overnight. Generally northeast winds
of 5 to 15 mph are expected through this evening.
12
PREV DISCUSSION... /ISSUED 355 AM CST Mon Dec 9 2013/
DISCUSSION...
Another cold front is moving through the area early this morning
bringing a resurgence of very cold air. We are not seeing any
freezing fog so far either ahead of or behind the front, and
despite mostly clear skies and low T/Td depressions, concern is
dropping for a serious freezing fog threat. It is still possible
for some patchy freezing fog to form especially near the leading
edge of the front with the fog threat diminishing farther behind
the front as drier air filters south. The small T/Td depressions
could allow for some ice condensation to occur on exposed surfaces
despite the lack of fog creating slick spots on local roads.
Models have backed off snow chances in SE NM today and tonight
likely due to limited moisture and a very positively tilted weak
upper trough so have removed PoPs.
We then see slightly warmer temps Tuesday and Wednesday before a
weak front arrives Thursday. A more zonal upper air pattern will
limit the amount of cold air. Shortly following this front will be
an upper level low moving out of the southwestern states. This low
will be weakening as it approaches the area and may even be an
open trough by the time it arrives over west Texas, but there
should be enough moisture and instability for precipitation to
develop Thursday. The amount and extent of precipitation will
depend greatly on the strength of the upper low...the stronger the
low the more likely it is the precip will spread farther west...a
weak low or trough will push moisture and most precip to the
eastern CWA. For now the consensus seems to be that it will be an
open trough and thus will keep precip chances to the eastern
counties. Temperatures at this time indicate the p-type would be
rain so there may not be any travel worries this time. Friday gets
warmer before yet another front arrives Saturday.
Hennig
&&
.PRELIMINARY POINT TEMPS/POPS...
ANDREWS TX 29 18 43 25 / 10 10 0 0
BIG SPRING TX 28 18 44 26 / 10 10 0 0
CARLSBAD NM 42 25 48 27 / 10 10 0 0
DRYDEN TX 51 27 49 30 / 0 0 0 0
FORT STOCKTON TX 46 22 50 29 / 0 10 0 0
GUADALUPE PASS TX 44 22 44 28 / 10 10 0 0
HOBBS NM 32 17 45 24 / 10 10 0 0
MARFA TX 53 22 50 26 / 0 10 0 0
MIDLAND INTL AIRPORT TX 32 18 44 25 / 10 10 0 0
ODESSA TX 32 19 45 26 / 10 10 0 0
WINK TX 39 22 47 25 / 10 10 0 0
&&
.MAF WATCHES/WARNINGS/ADVISORIES...
NM...NONE.
TX...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
554 AM CST MON DEC 9 2013
.UPDATE...
To expand the Freezing Fog Advisory...
&&
.DISCUSSION...
Areas of freezing fog across the Big Country, Heartland and
Northwest Hill country continue to expand to the south and west.
Temperatures are below freezing across the entire area and given
the expansion of the fog, I went ahead and expanded the advisory
to include all of the Big Country and the northern Concho Valley.
The freezing fog could approach areas farther south in the next
few hours, including San Angelo, so I will continue to monitor
trends and these counties may need to eventually be added.
Otherwise, the rest of the forecast looks on track.
Please see the aviation discussion below...
&&
.AVIATION...
Stratus/fog continues to expand through much of West Central Texas
this morning resulting in IFR to LIFR conditions. KSOA is a bit
more tricky, as the stratus to the south is struggling to expand
northward. For now, I have indicated MVFR ceilings by 14z, and
will continue to monitor. Some improvement in ceilings is forecast
by late morning or early afternoon, with MVFR ceilings returning
to most sites. Winds today will be from the north at 5 to 10 knots
&&
.PREV DISCUSSION... /ISSUED 356 AM CST MON DEC 9 2013/
SHORT TERM...
Today and Tonight
A cold front is currently moving through the Big Country and
should be approaching the Interstate 10 corridor shortly after
sunrise. Winds behind the front will become north and increase to
about 8 to 12 mph, with colder air slowly filtering into West
Central Texas. In addition, areas of freezing fog are evident just
to the east of our area, which has slowly been creeping west. I
expect this freezing fog to expand to a Throckmorton, to Coleman,
to Mason line in the next few hours. A freezing fog advisory is in
effect for parts of the Heartland through 9 AM, and I will
continue to monitor trends for the possibility of expanding it
north into parts of the Big Country and south toward Mason county.
The HRRR is also indicating some post frontal fog across parts of
the Big Country, which will need to be monitored. Stratus should
fill in this morning behind the front, with much of the area
becoming overcast by mid morning. Given the expected cloud cover
and cold air advection, I lowered high temperatures slightly.
Highs will range from the upper 20s north of Interstate 20, to the
mid 40s across the Interstate 10 corridor.
Cloudy skies through much of the overnight period will not
support ideal radiational cooling conditions, but given the cold
airmass that will be filtering into the region, I went ahead and
lowered low temperatures slightly. Tuesday morning low
temperatures will generally be in the teens to lower 20s across
all of West Central Texas.
Daniels
LONG TERM...
Tuesday through Sunday
As a fast moving shortwave trough moves through the Great Lakes
region Tuesday night into Wednesday, a cold front will move into
Texas, causing another brief cooling for Wednesday into Thursday.
However, no precipitation is expected with the front. Lee
troughing on Thursday will allow winds to quickly turn back to the
south in our area, allowing temperatures to warm back up across
the area Thursday and especially Friday. An upper level low
initially off the coast of California on Monday will move across
the Desert Southwest and into the Texas panhandle by Friday. As
this low approaches, weak shortwaves will move across the area out
ahead of it, interacting with moisture return and low level warm
air advection, resulting in at least a slight chance for showers
mainly Thursday afternoon and Thursday night, with some lingering
showers moving out of the area on Friday.
The upper level low will then move east towards the Mississippi
Valley by Saturday, sending a cold front into the area. And while
the cold front will slow the warming trend, the air mass behind
the front will not be of arctic origin, so while we have gone
cooler than the MOS guidance for Saturday and Sunday, temperatures
should continue to trend closer to normal values through the
weekend.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 18 39 27 42 24 / 5 0 0 0 5
San Angelo 19 44 26 46 26 / 5 0 0 0 5
Junction 22 47 24 52 29 / 10 5 0 0 10
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY until 10 AM CST this morning FOR THE
FOLLOWING ZONES: Brown...Callahan...Coke...Coleman...Fisher...
Haskell...Jones...Kimble...Mason...McCulloch...Nolan...Runnels...
San Saba...Shackelford...Sterling...Taylor...Throckmorton.
&&
$$
Daniels
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
542 AM CST MON DEC 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 9 2013
MAIN SHORT TERM CONCERNS ARE ON TEMPERATURES...WIND CHILLS AND
POTENTIAL FOR MORE SNOW LATER TONIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A HIGHLY AMPLIFIED RIDGE OVER THE EASTERN PACIFIC...A DEEP
TROUGH FROM CENTRAL CANADA INTO THE FOUR CORNERS...AND RIDGING OVER
THE SOUTHEASTERN U.S.. WITHIN THE DEEP TROUGH THERE WERE 3
SHORTWAVES OF NOTE. THE FIRST WAS OVER SOUTHEAST WISCONSIN WHICH
HELPED BRING THE SNOW TO THE AREA YESTERDAY INTO THE EARLY MORNING
HOURS. MOST OF THE SNOW HAS PUSHED OFF TO THE EAST AS SHOWN BY RADAR
IMAGERY...IN RESPONSE TO SUBSIDENCE AND ISENTROPIC DESCENT IN THE
WAKE OF THE SHORTWAVE. THE SECOND SHORTWAVE OF NOTE WAS OVER THE
DAKOTAS. ALTHOUGH THIS SHORTWAVE WAS ONLY PRODUCING SOME ALTOSTRATUS
AHEAD OF IT...DUE TO DRY AIR SEEN ON THE 00Z BIS SOUNDING...THERE
WAS PLENTY OF COLD AIR WITH IT. 850MB TEMPS ACCORDING TO THE RAP ARE
-25C ACROSS NORTH DAKOTA...OR 2 STANDARD DEVIATIONS BELOW NORMAL.
FINALLY...THE THIRD SHORTWAVE WAS COMING DOWN THE BACK SIDE OF THE
TROUGH THROUGH CENTRAL ALBERTA. IMPRESSIVE 140KT JET AT THE
TROPOPAUSE ACCOMPANYING THE SHORTWAVE. ALREADY SOME LIGHT SNOW
FALLING JUST AHEAD OF THE SHORTWAVE.
A LOT OF RAPID MOTION FORECAST OVER THE NEXT 24 HOURS IN THE UPPER
LEVEL PATTERN...MOSTLY A RESULT FROM THAT STRONG UPPER JET CORE
COMING THROUGH ALBERTA. FIRST OFF...THE SHORTWAVE TROUGH OVER NORTH
DAKOTA IS PROGGED BY MODELS TO SLIDE THROUGH THE FORECAST AREA THIS
AFTERNOON. WE MAY SEE SOME MID OR HIGH CLOUDS PASS THROUGH AHEAD OF
THE SHORTWAVE...BUT THE BULK OF THE CLOUD COVER IS GOING TO BE THE
CURRENT STRATUS AFFECTING THE AREA. ANTICIPATING AS THE SHORTWAVE
PASSES...THE DRY ARCTIC AIR SEEN ACROSS NORTH DAKOTA CURRENTLY WILL
CLEAR OUT THE STRATUS. THIS MAY HAPPEN PRETTY QUICK WITH CLEARING
ALREADY COMING INTO THE FORECAST AREA. IN ADDITION...THAT SAME
ARCTIC AIR IS EXPECTED TO CAUSE TEMPERATURES TO FALL AS 850MB TEMPS
PLUMMET FROM THE CURRENT -14 TO -18C READINGS TO -18 TO -22C BY 21Z.
WINDS LOOK TO CRANK UP TOO AS THAT SHORTWAVE AND ASSOCIATED COLD AIR
COME IN. THESE WINDS...WITH GUSTS UPWARDS OF 20 TO 30 MPH...ARE
LIKELY TO CAUSE SOME BLOWING AND DRIFTING OF THE RECENT SNOW. AS
TEMPERATURES FALL THIS AFTERNOON...WIND CHILLS WILL BECOME MORE OF
AN ISSUE. TAYLOR/CLARK COUNTIES LOOK TO DROP INTO ADVISORY RANGE
AROUND 22Z AND DO NOT GET OUT UNTIL 12Z TUESDAY...THUS HAVE GONE
AHEAD AND ISSUED AN ADVISORY FOR THEM.
THE COLD AIR TONIGHT DOES NOT LAST LONG. MODELS ARE IN GOOD
AGREEMENT SHOWING THE ALBERTA SHORTWAVE DIGGING INTO THE DAKOTAS
THIS EVENING...THEN MOVING INTO THE FORECAST AREA TOWARDS 12Z. AS
THIS SHORTWAVE APPROACHES...WARM ADVECTION ENSUES...WITH 850MB TEMPS
CLIMBING UP TO -13 TO -17C BY 09Z. ALL INDICATIONS ARE THAT THE
ISENTROPIC LIFT AND SOME MOISTURE ADVECTION WILL CAUSE A MID CLOUD
DECK TO SPREAD ACROSS THE FORECAST AREA. THESE CLOUDS AND THE WARM
ADVECTION SHOULD RESULT IN RISING TEMPS LATE THIS EVENING INTO THE
OVERNIGHT...HELPING TO BRING WIND CHILLS UP. ADDITIONALLY...THE BEST
JUXTAPOSITION OF LOW LEVEL SATURATION AND ISENTROPIC LIFT OCCURS
NORTH OF INTERSTATE 90. GIVEN THE ARCTIC AIRMASS IN PLACE PRIOR TO
THE SHORTWAVE ARRIVAL...LIKELY WILL NOT TAKE MUCH TO SNOW. QPF MAY
NOT AMOUNT TO MUCH WITH THE COLD AIRMASS...MAYBE A COUPLE HUNDREDTHS
TOPS...BUT ENOUGH FORCING TO WARRANT HIGH PRECIPITATION CHANCES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 9 2013
MAIN LONG TERM FORECAST CONCERNS ARE ON TEMPERATURES...AS WELL AS
THE OSCILLATING DIURNAL TRENDS WITH THEM...AND POTENTIAL FOR
PRECIPITATION THROUGHOUT.
SHORTWAVE TROUGH COMING INTO THE FORECAST AREA TONIGHT QUICKLY MOVES
THROUGH DURING THE TUESDAY MORNING HOURS. ANY SNOW LOOKS TO DEPART
OFF TO THE EAST PRETTY FAST IN THE MORNING...FOLLOWED BY CLEARING
AND BRISK WEST WINDS. THESE WINDS COULD RESULT IN MORE BLOWING
SNOW...ESPECIALLY IF WE CAN GET A FEW TENTHS OUT OF TONIGHT.
ADDITIONALLY...THE WINDS DRIVE IN A BRIEF SURGE OF ARCTIC AIR WITH
850MB TEMPS FALLING TO -16 TO -20C BY 18Z. 09.00Z
ECMWF/NAM/CANADIAN/GFS THEN ALL DEPICT YET ANOTHER SHORTWAVE TROUGH
DROPPING INTO THE DAKOTAS TUESDAY NIGHT. AHEAD OF THIS
FEATURE...INCREASING ISENTROPIC LIFT AND MID LEVEL FRONTOGENESIS
LOOKS TO DEVELOP A BAND OF SNOW. POSITION OF THIS BAND OF SNOW IS
PROBLEMATIC...WITH THE ECMWF/NAM FARTHER NORTH COMPARED TO THE
GFS/CANADIAN. CONSENSUS WOULD SUGGEST LOCATIONS SOUTH OF I-90 WOULD
STAND TO SEE THE BEST CHANCE OF SEEING SNOW...SO RAISED CHANCES
TOWARDS 60 IN THIS AREA. THE BAND DOES APPEAR TO BE QUICK MOVING...
SUCH THAT BY 12Z WEDNESDAY...ITS ALREADY SOUTHEAST OF THE AREA.
NONETHELESS...WITH SNOW TO WATER RATIOS APPROACH 20 TO 1...WE COULD
SQUEEZE OUT AN INCH OR SO OUT OF THIS BAND.
JUST LIKE IN THE WAKE OF THE EVERY SHORTWAVE TROUGH...ANOTHER SURGE
OF ARCTIC AIR IS PROGGED TO FLOW INTO THE AREA ON WEDNESDAY WHEN THE
TROUGH MOVES THROUGH. 850MB TEMPS DROP TO -20 TO -24C AT 18Z
WEDNESDAY. THUS...DESPITE THAT SKIES SHOULD CLEAR ON WEDNESDAY AS
THE TROUGH COMES IN...IT WILL BE TOUGH TO WARM UP MUCH. MOST
LOCATIONS ARE LIKELY TO NOT GET OUT OF THE SINGLE DIGITS ABOVE
ZERO...AND NORTH OF HIGHWAY 10 MAY NOT EVEN GET TO ZERO. WITH THE
COLD TEMPS AND A NORTHWEST BREEZE...WIND CHILLS ARE YET AGAIN A
FACTOR WITH ANOTHER ADVISORY LIKELY NEEDED. NORTH OF HIGHWAY 10
APPEARS TO BE THE MOST LIKELY AREA FOR AN ADVISORY...STARTING LATE
TUESDAY NIGHT AND RUNNING THROUGH WEDNESDAY NIGHT. WEDNESDAY NIGHT
IS INTERESTING TOO. ALL MODELS ARE SUGGESTING RISING 500MB HEIGHTS
ACROSS THE CENTRAL PART OF THE COUNTRY. WARM ADVECTION ASSOCIATED
WITH THESE RISING HEIGHTS SHOULD CAUSE TEMPERATURES TO RISE...AFTER
A RAPID DROP OFF IN THE EVENING ASSOCIATED WITH A SURFACE RIDGE
PASSAGE. THERE MAY EVEN BE SOME SNOW THAT TRIES TO GET GOING NORTH
OF I-94...AS SUGGESTED BY THE ECMWF/CANADIAN AND HAVE INCLUDED 20
PERCENT CHANCES FOR THIS. THESE CHANCES PERSIST INTO THURSDAY. MUCH
WARMER 850MB TEMPS ON THURSDAY...ON THE ORDER OF -2 TO -8C BY
00Z...WILL RESULT IN HIGHS 15-20 DEGREES WARMER COMPARED TO
WEDNESDAY.
FROM THURSDAY NIGHT THROUGH SUNDAY...09.00Z ECMWF/GFS/CANADIAN
SUGGEST A NORTHWEST FLOW PATTERN IN THE MEAN...STRETCHING FROM
BRITISH COLUMBIA INTO THE GREAT LAKES. AT THE MOMENT THURSDAY NIGHT
LOOKS DRY. AS WE HEAD INTO FRIDAY AND ESPECIALLY FRIDAY
NIGHT...THERE ARE SUGGESTIONS A SOUTHERN STREAM SHORTWAVE TROUGH
COMING OUT OF THE CENTRAL PLAINS AND HEADING INTO THE OHIO VALLEY
COULD SPREAD SOME LIGHT SNOW INTO THE FORECAST AREA. THE CANADIAN IS
THE FARTHEST NORTHWEST AND DID HONOR THE SOLUTION WITH A 20 PERCENT
CHANCE. HOWEVER...THE 09.00Z GFS/ECMWF SUGGEST IT COULD STAY TO THE
SOUTHEAST...THUS SOMETHING TO MONITOR. HEADING INTO THE WEEKEND...
THE ECMWF/GFS SUGGEST A POTENT UPPER TROUGH WILL BE DROPPING SOUTH
INTO MANITOBA AND ONTARIO. THE ECMWF IS VERY AGGRESSIVE DIGGING IT
INTO WISCONSIN ON SUNDAY. FOR NOW STAYED WITH THE CONSENSUS WHICH
YIELDS A GENERALLY DRY SOLUTION WITH TEMPERATURES HOVERING SLIGHTLY
BELOW NORMAL. HOWEVER...SHOULD THE 00Z ECMWF BE CORRECT...
TEMPERATURES MAY NEED SIGNIFICANT LOWERING FOR SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 542 AM CST MON DEC 9 2013
VFR TO MVFR CONDITIONS ARE EXPECTED AT THE TAF SITES TODAY. GUSTY
WEST WINDS OF 14 TO 18 KTS WITH GUSTS AROUND 24KTS WILL LEAD TO
SOME PATCHY BLOWING SNOW...POSSIBLY REDUCING VISIBILITIES TO
AROUND 5SM AT TIMES. SOUTH/SOUTHWEST WINDS WILL INCREASE LATE
TONIGHT AHEAD OF A WEAK SYSTEM APPROACHING FROM THE NORTHERN
PLAINS. LOOK FOR WINDS TO INCREASE INTO THE 14 TO 18 KT RANGE
AGAIN WITH GUSTS AROUND 25 KTS POSSIBLE. SOME PATCHY BLOWING SNOW
MAY OCCUR AGAIN LATE TONIGHT AS THE WINDS INCREASE. LIGHT SNOW OR
FLURRIES WILL MOVE ACROSS THE TAF SITES MAINLY AFTER 10Z TONIGHT.
A BRIEF PERIOD OF MVFR OR POSSIBLY IFR CONDITIONS MAY OCCUR AS THE
SNOW MOVES THROUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM CST TUESDAY
FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
338 PM MST MON DEC 9 2013
.SHORT TERM...SUBSIDENCE BEHIND THIS MORNING`S WEAK TROUGH
COMBINED WITH INCREASING PRESSURE GRADIENT FROM GJT TO DEN AND
MIXING TO PRODUCE GUSTY WINDS ACROSS MOUNTAINS AS WELL AS IN AND
NEAR FOOTHILLS. LATEST RAP ANALYSIS SHOWING THE MAIN BATCH OF
SUBSIDENCE NOW MOVING OVERHEAD. MOST GUSTS WERE AROUND 40
MPH...THOUGH THERE WERE GUSTS AROUND 55 MPH IN WIND PRONE AREAS IN
THE FOOTHILLS OF NORTHERN JEFFERSON COUNTY. WINDS WERE LESS
FURTHER AWAY FROM THE FOOTHILLS. THE GUSTY WINDS WERE PRODUCING
SOME BLOWING SNOW...CONFINED TO OPEN AREAS. THE GUSTY WINDS WILL
PERSIST INTO THE EVENING THEN RETREAT INTO THE HIGHER FOOTHILLS BY
MIDNIGHT AS MIXING AND SUBSIDENCE WEAKENS. BUT THESE WINDS SHOULD
ALSO STRENGTHEN AS CROSS MOUNTAIN FLOW INCREASES TO AROUND 40 KTS.
THIS COULD RESULT IN GUSTS AROUND 65 MPH IN WIND PRONE AREAS. NOT
EXPECTING THE GUSTS REACHING HIGH WIND CRITERIA OF 75 MPH AT THIS
TIME. SOME BLOWING SNOW WILL BE POSSIBLE...ESPECIALLY IN OPEN
AREAS. A BIT OF MOISTURE STILL TRAPPED ACROSS THE MOUNTAIN AND
THERE MAY BE A FEW LIGHT SNOW SHOWERS OR FLURRIES. OVERNIGHT
TEMPERATURES EXPECTED TO FALL INTO THE SINGLE DIGITS ACROSS THE
PLAINS WITH BELOW ZERO READINGS IN THE HIGH COUNTRY AND LOW LYING
AREAS NEAR LIMON AND GREELEY. TEMPERATURES TO BE WARMER IN AND
NEAR FOOTHILLS DUE TO THE DOWNSLOPE WINDS. ON TUESDAY...NORTHWEST
FLOW ALOFT TO PREVAIL. THERE WILL BE SOME WARMING DUE TO UPPER
LEVEL RIDGE BUILDING ACROSS THE GREAT BASIN AND DOWNSLOPE WINDS
ALONG FOOTHILLS. TEMPERATURES ACROSS THE PLAINS TO WARM INTO THE
LOWER 30S...WITH UPPER 20S IN THE LOW LYING AREAS. MOUNTAIN AREAS
SHOULD WARM INTO THE TEENS BUT GUSTY WINDS WILL KEEP WIND CHILL
READINGS BELOW ZERO. GUIDANCE VALUES STILL A BIT OPTIMISTIC WITH
THE WARMUP. SOME MOISTURE AND WEAK LIFT MOVES INTO THE NORTHERN
MOUNTAINS...ENOUGH FOR A SLIGHT CHANCE OF LIGHT SNOW. ANY
ACCUMULATIONS TO BE MINIMAL.
.LONG TERM...WEATHER THE NEXT WEEK WILL BE DOMINATED BY A RIDGE
OVER COLORADO. WEAK RIPPLES COMING NORTH OF US IN WESTERLY FLOW
AND A WEAK LOW PASSING WELL SOUTH OF US. ALL OF THESE THINGS
CONTINUE TO GET WEAKER WITH SUBSEQUENT MODEL RUNS AND SHOULD NOT
HAVE MUCH EFFECT ON OUR WEATHER. THERE WILL BE A CHANCE OF LIGHT
SNOW IN THE MOUNTAINS WITH THE TAIL END OF THE NORTHERN SHORT
WAVES...AND WEAK SURGES OF COOL AIR FROM THE NORTH AS WELL. THESE
WILL COME ABOUT FRIDAY AND AGAIN ON SUNDAY OR MONDAY...BRINGING
A LITTLE COOLING...OR DELAYING THE WARMING...EACH DAY. BY THE END
OF THE WEEK THE AIR ALOFT WILL BE QUITE WARM...BUT THE LOW LEVELS
WILL LAG BEHIND. ALL OF THIS IS WELL COVERED IN THE CURRENT
FORECAST AND THE MODEL CONSENSUS LOOKS GOOD.
&&
.AVIATION...WESTERLY WINDS HAVE PUSHED ACROSS THE AREA
AIRPORTS WITH GUSTS AROUND 35 KTS AT KBJC. WINDS MUCH LESS AT KDEN
AND KAPA...AROUND 12 KTS. WINDS AT KDEN AND KAPA WILL TRANSITION
TO DRAINAGE BY 02Z...REMAINING WESTERLY AT KBJC. SOME GUSTS COULD
AGAIN REACH 35 KTS AT KBJC OVERNIGHT. ON TUESDAY...WINDS WILL
WEAKEN AND BECOME NORTHWEST BY 17Z...SPEEDS AROUND 8 KTS. VFR TO
CONTINUE WITH UNLIMITED CEILINGS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....GIMMESTAD
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
603 PM EST MON DEC 9 2013
.SYNOPSIS...
LOW PRESSURE EAST OF LONG ISLAND IS MOVING NORTHEAST WHILE A NEW
AREA OF LOW PRESSURE FORMS IN NORTH CAROLINA TONIGHT. THAT NORTH
CAROLINA LOW ZIPS NORTHEAST OUT TO SEA TUESDAY AFTERNOON YANKING IN
COLDER AIR BEHIND IT TUESDAY NIGHT. HIGH PRESSURE WILL THEN BUILD
INTO THE REGION FROM THE WEST DURING MID AND LATE WEEK BEFORE
SHIFTING INTO THE WESTERN ATLANTIC SATURDAY. LOW PRESSURE AND A NEW
COLD FRONT ARE SLATED TO MOVE ACROSS THE MID ATLANTIC STATES LATE
SATURDAY. CANADIAN HIGH PRESSURE SHOULD FOLLOW...ARRIVING IN THE
NORTHEAST UNITED STATES EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SHORT TERM UPDATE MAINLY ADDRESSED THE MENTION OR LACK THEREOF OF
FOG INTO EARLY THIS EVENING. A WESTERLY GRADIENT OVER OUR CWA HAS
HELPED THIN THE FOG. BASED ON THE LATEST HRRR AND RAP WE PUSHED
BACK THE ONSET OF POPS A COUPLE OF HOURS. WILL TAKE A CLOSER LOOK
AS TO HOW THE MODELS ARE VERIFYING AT 00Z.
WE`LL BE IN A LULL MOST OF TONIGHT, BETWEEN YESTERDAY`S SNOW AND
WHAT`S TO COME TOMORROW. IMPACTS TONIGHT WILL BE ASSOCIATED WITH FOG
AND RESTRICTIVE VISIBILITIES AND SUB-FREEZING TEMPERATURES THAT
COULD REFREEZE WHAT`S CURRENTLY ON THE GROUND.
TEMPERATURES WILL FALL INTO THE LOWER 20S ACROSS THE NORTHWEST ZONES
AND INTO THE UPPER 20S ELSEWHERE.
PRECIPITATION WILL BE REENTERING THE PICTURE TOMORROW MORNING.
THINGS COULD START TO RAMP UP PRIOR TO 6AM. SOUNDINGS SUGGEST ALL
SNOW AT THE ONSET EXCEPT FOR OUR SOUTHERN COUNTIES WHERE SOME
FREEZING RAIN AND SLEET IS POSSIBLE. THE MORNING RUSH COULD BE
IMPACTED, ALTHOUGH IT APPEARS, AT LEAST AT THIS TIME, THAT WHEN YOU
GET NORTH OF DELMARVA, THE ONSET OF PRECIPITATION WILL COMMENCE
DURING THE SECOND HALF OF THE COMMUTE.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH 6 PM TUESDAY/...
WINTER STORM WARNINGS AND WINTER WEATHER ADVISORIES HAVE BEEN
ISSUED. ALTHOUGH BANDING PREDICTABILITY IS FAIRLY LOW, MODELS ARE
POINTING TO THE I95 CORRIDOR AT THIS TIME.
H8-H7 FORCING IS IN PLACE TOMORROW MORNING AS WELL OMEGA. DECENT
SNOW GROWTH IS FORECAST AND WE`RE UNDER THE RIGHT REAR OF THE H3
JET. THE FEELING IS...THERE WILL BE AT LEAST MODERATE SNOW FOR A FEW
HOURS THAT WILL COMPENSATE FOR A DAYTIME SNOWFALL WITH TEMPERATURES
NEAR FREEZING.
WE LIKE 3 TO 5 INCHES ACROSS THE I95 CORRIDOR AND THAT`S WHAT IS IN
THE WSW. OUR GRAPHICS ON THE WEB WILL DISPLAY 4 TO 6 INCHES, WITH 3
TO 5 NOT BEING AN OPTION. LESS AMOUNTS SHOULD FALL ACROSS THE FAR
NORTHWESTERN ZONES, THE FAR SOUTHERN ZONES AND RIGHT ALONG THE COAST.
THE GFS QPF IS ON THE HIGH SIDE OF THE SPECTRUM WHILE THE EURO IS ON
THE LOWER SIDE. WE`RE IN THE MIDDLE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH MONDAY/...
500MB: A BROAD TROUGH IN EASTERN UNITED STATES SHARPENS UP A BIT
THURSDAY AS SHORT WAVES MOVE THROUGH THE BASE OF THE TROUGH. RIDGING
FOLLOWS FRIDAY AND THEN WE WAIT TO SEE HOW THE MID WEEK CLOSED LOW
NEAR BAHA CALIFORNIA INTERACTS WITH THE NORTHERN STREAM FOR NEXT
WEEKEND. LOTS OF UNCERTAINTY IN THE MODELS FOR NEXT WEEKEND WHICH
INCLUDES TEMPS...PTYPE AND STORM TRACK. TROUGHING DEVELOPING IN
THE EASTERN USA MAKES IT PROBABLE THAT SOME SORT OF PRECIPITATION
SHOULD DEVELOP HERE NEXT WEEKEND.
TEMPERATURES: MUCH BELOW NORMAL COLD FOR PORTIONS OF THIS EXTENDED
PERIOD WITH CALENDAR DAY AVERAGE VALUES EXPECTED TO BE 10 DEGREES OR
MORE COLDER THAN NORMAL WEDNESDAY THROUGH FRIDAY AND POSSIBLY AGAIN
NEXT MONDAY WITH FRIDAYS TEMPERATURES POSSIBLY 15 DEGREES BELOW
NORMAL! THE MILDEST DAYS SHOULD BE SATURDAY AND OR SUNDAY.
FORECAST BASIS... TUE NIGHT-WED NIGHT IS A 50 50 BLEND OF THE 12Z/9
GFS/NAM MOS. THURSDAY IS 100 PCT 12Z/9 GFS MOS AND THEN THU NIGHT-
NEXT MONDAY IS THE 1522Z/9 WPC EXTENDED GRIDS. THIS DATA IS CHECKED
AGAINST THE 12Z/9 ECMWF...MODIFIED AND NOTED IN THE DAILIES WHEN
SIGNIFICANT. THE 09Z/9 SREF WAS CHECKED FOR POPS WITHIN ITS FORECAST
RANGE THE 12Z/9 GEFS 6HR POPS FOR .05 WERE CHECKED FOR THE EXTENDED
GRIDS THURSDAY-MONDAY.
THE DAILIES BELOW...
TUE NIGHT...CLEARING AND COLDER WITH FREEZE UP OF THE TUESDAY SNOW
EVENT. WINTRY LOOKING NIGHT-SCAPE. A BIT OF AN ADDED WIND CHILL
TOO!
WEDNESDAY AND THURSDAY...POTENTIAL FOR BURSTS OF SNOW SHOWERS
NEAR AND NORTH OF I80 IN NE PA AND NW NJ AS THE SOUTHERN EXTENT
OF WINDEX EVENTS ARE SUGGESTED BY THE GUIDANCE TO GRAZE THE NORTHERN
PORTION OF OUR FORECAST AREA. THE SHORT WAVES ARE SENDING IN BURSTS
OF COLDER AIR IN GENERAL WNW FLOW AND YOU COULD ARGUE THAT A SECONDARY
COLD FRONTAL PASSAGE CAN OCCUR WEDNESDAY NIGHT. BLUSTERY DAY TIMES.
OVERALL SOUTH OF I80...P/C...POSSIBLY A FLURRY OR 2. THE WCI MAY
DROP TO 10 BELOW ZERO IN THE POCONOS THU NIGHT.
FRIDAY...COLD INTERLUDE WITH INCREASING CLOUDS POSSIBLE?
NEXT WEEKEND...POTENTIAL FOR PERIODS OF WINTRY PCPN...ESPECIALLY
SATURDAY...DEPENDING ON SFC LOW EVOLUTION ON A NEW COLD FRONT
CROSSING EASTWARD FROM THE APPALACHIANS. RIGHT NOW OUR FCST IS
HINGED COMPLETELY ON WPC GUIDANCE. ITS CATEGORICAL THAT IT WILL
PRECIPITATE BUT CONFIDENCE ON DETAILS INCLUDING TEMPS AND PTYPE IS
WELL BELOW AVERAGE.THE FCST DRAWN UP FOCUSES PCPN ON SATURDAY ENDING
SATURDAY EVENING.
NEXT MONDAY...BLUSTERY AND COLD...AT LEAST TO START. THE WCI MAY
DROP TO 10 BELOW IN THE POCONOS EARLY MONDAY BUT CONFIDENCE ON
COLD TEMPS MONDAY IS LESS THAN THE HIGH CONFIDENCE FCST FOR
WEDNESDAY-FRIDAY.
&&
.AVIATION /23Z MONDAY THROUGH SATURDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
LATE-DAY...IFR CONDITIONS WILL CONTINUE THROUGH THE REMAINDER OF THE
AFTERNOON. WEST/NORTHWEST WINDS WILL BE LESS THAN 10 KT.
TONIGHT...IFR IS FORECAST TO TRANSITION TO MVFR BEFORE THE NEXT
ROUND OF PRECIPITATION SETTLES INTO THE REGION. NORTHWEST WINDS WILL
BE LESS THAN 10 KT.
TUESDAY...MVFR WILL QUICKLY TRANSITION INTO IFR AS SNOW SETTLES IN
ACROSS THE TERMINALS. A PERIOD OF LIFR IS POSSIBLE IN SOME HEAVIER
SNOW. SOME IMPROVEMENT, MVFR, CAN BE EXPECTED LATER IN THE DAY.
OUTLOOK...
TUESDAY NIGHT...VFR NW WIND GUST TO 20 KT. CONFIDENCE ABOVE AVG.
WEDNESDAY - THURSDAY...VFR SCT-BKN AOA 3500 FT. CHANCE OF A FLURRY
EXCEPT A FEW PERIODS OF MVFR OR IFR CONDS IN SNOW SHOWERS AR
POSSIBLE IN THE POCONOS. W-NW WIND G 20-25 KT EACH AFTN.
CONFIDENCE ABOVE AVERAGE. I DID RAISE 12Z/9 NCEP MOS GUIDANCE BY
ABOUT 4 DEGREES PRIMARILY BECAUSE OF STILL RELATIVELY MILD 850
TEMPS AND THE 12Z/9 UK AND EC 2M TEMPS.
FRIDAY...VFR CIGS. WIND TURNING WEST OR SOUTHWEST IN THE AFTN.
SATURDAY...MVFR OR IFR CONDS PROBABLE IN PCPN.
&&
.MARINE...
TONIGHT...NO HEADLINES WITH DIMINISHING WINDS AND SEAS IN THE 2 TO 4
FOOT RANGE.
TUESDAY...BOTH NORTHWEST WINDS AND SEAS WILL BEGIN TO BUILD LATER
TOMORROW. GUIDANCE SUGGESTS THAT SCA CONDITIONS WILL BE BACK IN
PLACE LATE TOMORROW AFTERNOON OR EARLY TOMORROW EVENING.
OUTLOOK...
TUESDAY NIGHT - THURSDAY...A FAIRLY TIGHT GRADIENT WILL PERSIST WITH
PERIODS OF GUSTY WINDS TO 25 KT AND END OF WESTERLY FETCH SEAS ON
THE ATLANTIC NEAR 5 FT. WE MAY HAVE NEAR GALE FORCE GUSTS TUESDAY
NIGHT AND WEDNESDAY MORNING, ESPECIALLY ACROSS THE NORTHERN OCEAN
WATERS. SCA HAS BEEN STARTED. AN EXTENSION PROBABLE AND IT MAY
NEED AN UPGRADE TO A MARGINAL GALE IN LATER FCST FOR A PTN OF TUE
NIGHT.
FRIDAY...WINDS AND SEAS SHOULD SUBSIDE BELOW SMALL CRAFT ADVISORY
LEVELS AS HIGH PRESSURE BUILDS ACROSS THE REGION AND REMAIN BELOW
AS WE END THE WORK WEEK.
SATURDAY...AN SCA IS POSSIBLE. THERE IS MODEL SPREAD ON THE
SOLUTIONS BUT ITS EVEN POSSIBLE WE`LL NEED A SLY GALE FOR A PTN
OF THE ATLANTIC WATERS. THIS PART OF THE FCST IS VERY LOW
CONFIDENCE.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY FROM 6 AM TO 5 PM EST TUESDAY FOR
PAZ060>062-101-103-105.
WINTER STORM WARNING FROM 6 AM TO 5 PM EST TUESDAY FOR PAZ070-
071-102-104-106.
NJ...WINTER WEATHER ADVISORY FROM 6 AM TO 5 PM EST TUESDAY FOR
NJZ007>010-012>014-020>027.
WINTER STORM WARNING FROM 6 AM TO 5 PM EST TUESDAY FOR
NJZ015>019.
DE...WINTER WEATHER ADVISORY FROM 6 AM TO 5 PM EST TUESDAY FOR
DEZ002>004.
WINTER STORM WARNING FROM 6 AM TO 5 PM EST TUESDAY FOR DEZ001.
MD...WINTER WEATHER ADVISORY FROM 6 AM TO 5 PM EST TUESDAY FOR
MDZ012-015-019-020.
WINTER STORM WARNING FROM 6 AM TO 5 PM EST TUESDAY FOR MDZ008.
MARINE...SMALL CRAFT ADVISORY FROM 5 PM TUESDAY TO 6 AM EST WEDNESDAY
FOR ANZ430-431-450>455.
&&
$$
SYNOPSIS...DRAG
NEAR TERM...GIGI/KRUZDLO
SHORT TERM...KRUZDLO
LONG TERM...DRAG
AVIATION...DRAG/KRUZDLO
MARINE...DRAG/KRUZDLO
AREA FORECAST DISCUSSION
NWS MIAMI FL
152 PM EST MON DEC 9 2013
.DISCUSSION...
QUIET WEATHER WILL CONTINUE THROUGH TONIGHT, WITH WINDS BECOMING
LIGHT AND VARIABLE TO CALM OVER THE INTERIOR AREAS. THERE COULD BE A
ROUND OF FOG DEVELOPMENT. THE HRRR DOES KEEP IT OUT OF ITS
FORECAST THROUGH 04Z, WHICH IS THE EXTENT OF THE RUN AT THIS TIME.
HOWEVER, BUFKIT IS SHOWING THAT IT DOES FAVOR FOG. SO, HAVE KEPT
PATCHY FOG IN THE FORECAST FROM 06Z THROUGH 12Z.
PATTERN WISE, HIGH PRESSURE WILL WEAKEN THROUGH THE NIGHT. THIS IS
AHEAD OF A COLD FRONT THAT IS CURRENTLY WELL TO THE WEST, OVER NEW
ORLEANS. THIS FRONT WILL APPROACH THE FLORIDA PENINSULA AND WILL
BE ENHANCED BY A 500 MB SHORT WAVE. HOWEVER, AS IT APPROACHES
FLORIDA, THE ASSOCIATED LOW WILL BE QUICKLY MOVING OFF TO THE
NORTHEAST, TAKING MOST OF THE ENERGY AND MOISTURE WITH IT. THIS
WILL CAUSE THE FRONT TO STALL SOMEWHERE OVER NORTH CENTRAL
FLORIDA WEDNESDAY NIGHT.
AHEAD OF THIS FRONT, THERE WILL BE AN AREA OF CLOUDS AND SHOWERS
THAT WILL BEGIN TO AFFECT THE SOUTHERN TIP OF FLORIDA TOMORROW
MORNING. MODELS ARE IN DISAGREEMENT WITH THE EXTENT OF THE
COVERAGE OF THE SHOWERS. THE GFS KEEPS MOST OF THE ACTIVITY TO THE
SOUTH OF I75, BUT IT DOES HAVE SHOWERS OVER THE PENINSULA. THE
ECMWF KEEPS ALL ACTIVITY OFFSHORE, EXCEPT PERHAPS A LIGHT COASTAL
SHOWER. HAVE KEPT A CHANCE OF SHOWERS FOR MOST AREAS SOUTH OF I75
AND A SLIGHT CHANCE NORTH OF THAT FOR THE AFTERNOON HOURS. AFTER
THAT, MOST OF THE ACTIVITY IS EITHER OVER THE COASTAL WATERS, OR
JUST ALONG THE COAST, WITH INLAND AREAS FAIRLY DRY.
BY WEDNESDAY AFTERNOON, THE FRONT LOOKS TO DRIFT FAR ENOUGH SOUTH
TO BRING A CHANCE OF SHOWERS TO AREAS NORTH OF I75. AFTER THAT, A
SECONDARY HIGH BUILDS OVER THE MISSISSIPPI VALLEY, WHICH WILL PUSH
THE FRONT FURTHER SOUTH AND OVER THE FLORIDA STRAIGHTS. AS IT
DOES, IT MAY ENHANCE SHOWER ACTIVITY THURSDAY AFTERNOON AND
EVENING. THEN, EASTERLY FLOW RETURNS AS THE SURFACE HIGH SLIDES
EASTWARD. ALSO, AN UPPER LEVEL RIDGE WILL BE BUILDING OVER THE
AREA FOR THE WEEKEND. THIS WILL PROBABLY BRING MOSTLY DRY
CONDITIONS FOR THE WEEKEND, WITH THE EXCEPTION OF A SLIGHT CHANCE
OF SHOWERS BY SUNDAY.
&&
.AVIATION...
MAINLY VFR CONDITIONS EXPECTED TO PREVAIL THROUGH THE AFTERNOON
AND EVENING HOURS. A MODERATE SOUTHEASTERLY FLOW WILL PREVAIL
ACROSS THE REGION TONIGHT INTO TUESDAY. IN INCREASE IN MOISTURE IS
EXPECTED TUESDAY MORNING WITH A CHANCE OF SHOWERS POSSIBLE LATE
TUESDAY AND NOT INCLUDED IN THIS TAF ISSUANCE.
&&
.MARINE...
HIGH PRESSURE WILL BEGIN TO WEAKEN TONIGHT. THIS WILL BRING WINDS
AROUND TO THE SOUTH TOMORROW AS WELL AS SOME SHOWERS TO THE SOUTH
FLORIDA COASTAL WATERS. A COLD FRONT WILL APPROACH THE AREA
WEDNESDAY NIGHT AND STALL OVER CENTRAL FLORIDA AND ALL BUT
DISSIPATE. HIGH PRESSURE WILL QUICKLY TO THE NORTH, BEHIND THE
FRONT. THIS WILL BRING AN EASTERLY FLOW BACK TO THE SOUTH FLORIDA
WATERS WEDNESDAY. WITH THE WEAK FRONTAL BOUNDARY IN THE AREA, IT
WILL BRING A CHANCE OF SHOWERS FOR THE COASTAL WATERS THROUGH THE
END OF THE WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 71 82 70 82 / 10 20 20 30
FORT LAUDERDALE 72 82 71 82 / 10 40 30 30
MIAMI 72 82 72 83 / 10 40 30 30
NAPLES 67 81 67 82 / 0 20 20 30
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
DISCUSSION/MARINE/FIRE...13/SI
AVIATION/RADAR...60/BD
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
300 PM EST MON DEC 9 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 148 PM EST MON DEC 9 2013
SEVERAL WEAK WEATHER SYSTEMS AFFECT OUR REGION TODAY INTO MIDWEEK
WITH MORE SIGNIFICANT SYSTEM FOR THIS WEEKEND. COLD ARCTIC HIGH
PRESSURE TO RULE IN BETWEEN WITH TEMPERATURES REMAINING WELL BELOW
NORMAL THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 148 PM EST MON DEC 9 2013
CONCERN FOR TONIGHT IS SNOW/NO SNOW BOUNDARY AND HOW MUCH SNOW
WILL OCCUR. WILL NOT ISSUE ADVISORY FOR THIS BUT MAKE MENTION IN
HAZARDOUS WEATHER OUTLOOK AND SPECIAL WEATHER STATEMENT.
AS TAIL END OF FIRST WEAK SHORT WAVE EXITS GREAT LAKES THIS
AFTERNOON THE SECOND ONE OVER THE TX PANHANDLE REGION BEGINS TO
TAKE SHAPE AND AIM ON THE OHIO VALLEY. MODELS IN GOOD AGREEMENT ON
RAPID SPREAD OF NARROW SNOW BAND ENE ACROSS SOUTHERN AND CENTRAL
INDIANA SOUTH OF I-70 LATE EVENING AND OVERNIGHT...QUICKLY EXITING
BEFORE SUNRISE. THOUGH MOISTURE IS SOMEWHAT LIMITED...BRIEF
PERIOD OF DENDRITIC GROWTH MAXES OUT OVER SOUTHERN COUNTIES AND
WITH RATIOS NEAR 15 TO ONE...EXPECT SNOW AMOUNTS OVER ONE INCH BY
DAWN FROM VINCENNES TO BEDFORD-BLOOMINGTON...COLUMBUS AND SEYMOUR.
LOCAL TWO INCH AMOUNTS WILL LIKELY OCCUR. THE CUT-OFF FOR NO SNOW
WILL BE NEARLY PARALLEL AND JUST A BIT NORTH OF I-70 SO SOUTH SIDE
OF INDY METRO COULD SEE HALF INCH WHILE NORTH SIDE GETS JUST A
DUSTING.
CURRENT FORECAST TEMPS NOT BAD BUT WITH BRIEF PERIOD OF PARTIAL
CLEARING THIS EVENING...ESPECIALLY NORTHERN COUNTIES...HAVE
ADJUSTED TEMPS DOWN A COUPLE DEGREES BUT STILL 10-18F RANGE NW TO
SE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 148 PM EST MON DEC 9 2013
TONIGHT/S SYSTEM WILL BE RAPIDLY EXITING TUESDAY MORNING WITH
GUSTY WEST WINDS AND CLEARING SKIES DEVELOPING IN THE MORNING.
CURRENT MAX TEMPS IN LINE WITH LATEST DATA AND DESPITE SUNSHINE
EXPECT NO BETTER THAN MID TO UPPER 20S.
TUESDAY NIGHT...SKIES BEGIN TO CLOUD OVER ACROSS NORTHERN COUNTIES AS
CLIPPER SYSTEM AND ARCTIC FRONT SWEEPS INTO WESTERN GREAT LAKES BY
DAYBREAK WEDNESDAY. SOUTHERN COUNTIES REMAIN UNDER THE INFLUENCE
OF COLD HIGH PRESSURE AND MAINTAIN MOSTLY CLEAR SKIES. EXPECTING
SIMILAR LOWS WITH READINGS IN 10 TO 15F RANGE.
WEDNESDAY...CURRENTLY LOOKS LIKE THE QUICK CLIPPER SYSTEM/S
MEASURABLE SNOWS WOULD REMAIN NORTH OF A LAFAYETTE TO MUNCIE LINE
AND EVEN THERE AMOUNTS SHOULD BE NO MORE THAN A DUSTING TO HALF
INCH. STRONG ARCTIC HIGH PRESSURE RAPIDLY CLEARS SKIES WEDNESDAY
AFTERNOON AND SETS STAGE FOR CLEAR SKY WEDNESDAY NIGHT WITH SINGLE
DIGIT LOWS AFTER SLOWLY FALLING TEMPS WEDNESDAY AFTERNOON.
HIGH PRESSURE SETTLING INTO THE TENNESSEE VALLEY THURSDAY BRINGS
RETURN FLOW TO SOUTHWEST BUT LITTLE MODERATION OF TEMPS UNDER
SUNNY SKIES. FORECAST MAX TEMPS UPPER TEENS TO LOWER 20S STILL
APPEAR LIKELY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 255 PM EST MON DEC 9 2013
MAIN CHALLENGE FOR THE EXTENDED IS THE ARRIVAL AND IMPACT OF ANOTHER
POTENTIALLY MESSY WINTRY SYSTEM INTO THE OHIO VALLEY FRIDAY NIGHT
AND SATURDAY.
UPPER FLOW PATTERN WILL BRIEFLY TRANSITION FROM THE DEEP TROUGH TO
MORE OF A BROAD SOUTHWEST FLOW. AN UPPER WAVE WILL EJECT OUT OF
NORTHERN MEXICO ON FRIDAY AND QUICKLY TRACK INTO THE OHIO VALLEY BY
SATURDAY. A WEAK SURFACE WAVE WILL DEVELOP OVER THE SOUTHERN ROCKIES
AND MOVE INTO THE TENNESSEE VALLEY ON SATURDAY. THE MODEL
DIFFERENCES DEVELOP WITH RESPECT TO THE TIMING OF THE UPPER WAVE AND
THE STRENGTH OF THE SURFACE LOW. OP GFS CONTINUES TO HOLD THE UPPER
WAVE FURTHER WEST AND BRINGS A STRONGER SURFACE WAVE INTO THE REGION
SATURDAY...WHILE THE GLOBAL MODELS ARE MORE PROGRESSIVE ALOFT WITH A
WEAKER SURFACE WAVE TRACKING FURTHER TO THE SOUTH. THE TRACK AND
INTENSITY OF THE SURFACE WAVE WILL DETERMINE HOW MUCH WARM AIR
WITHIN THE BOUNDARY LAYER CAN BE ADVECTED NORTH INTO THE REGION LATE
FRIDAY NIGHT AND SATURDAY.
AT THIS POINT...AM LEANING TOWARDS THE COOLER GLOBAL MODELS WHICH
LIMIT ANY POTENTIAL MIXING OF PRECIP TO FAR SOUTHERN COUNTIES WHERE
CRITICAL LOW LEVEL THICKNESSES RISE TO AROUND 1305M FOR ABOUT 6-12
HOURS. SHOULD THIS COME TO PASS...SOUNDINGS WOULD SUPPORT FREEZING
RAIN AS THE PREDOMINANT TYPE LATE FRIDAY NIGHT INTO SATURDAY FOR
SEVERAL HOURS. WITH STILL PLENTY OF UNCERTAINTY AT THIS EARLY
STAGE...WILL CARRY A RA/SN MIX OVER THE FAR SOUTH WITH SNOW OVER THE
REST OF THE AREA. ENOUGH MOISTURE ACCOMPANYING THIS SYSTEM THAT
COULD SEE A FEW INCHES OF ACCUM FRIDAY NIGHT/SATURDAY IF PRECIP
REMAINS LARGELY IN THE FORM OF SNOW. WILL CERTAINLY BE KEEPING A
CLOSE EYE ON THE EVOLUTION OF THIS SYSTEM IN THE DAYS TO COME.
BEHIND THE SATURDAY STORM...COLDER AIR WILL ONCE AGAIN RETURN AS THE
POLAR VORTEX PINWHEELS THROUGH THE NORTHERN GREAT LAKES. HIGHS IN
THE 30S FRIDAY AND SATURDAY WILL FALL BACK INTO THE LOWER 20S BY
MONDAY WITH SINGLE DIGIT LOWS RETURNING EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 092100Z TAF ISSUANCE/...
ISSUED AT 1220 PM EST MON DEC 9 2013
STRATUS HAS BROKEN UP A BIT FASTER THAN PREVIOUSLY THOUGHT THIS
AFTERNOON. UPDATED TAFS TO REFLECT THAT. NO OTHER CHANGES.
18Z DISCUSSION FOLLOWS.
MVFR CEILINGS WILL CONTINUE THIS AFTERNOON. MVFR/IFR CONDITIONS
POSSIBLE TONIGHT AT ALL SITES EXCEPT KLAF IN LIGHT SNOW.
STUBBORN STRATUS DECK HOLDING WITH MOISTURE TRAPPED UNDERNEATH THE
INVERSION..BUT BREAKS IN THE LOWER DECK ARE TRYING TO EXPAND EAST
INTO THE REGION. EXPECT MORE SUBSTANTIAL DEPARTURE OF THE STRATUS TO
TAKE MUCH OF THE AFTERNOON TO LIFT AND MIX OUT WITH COLD ADVECTION
ONGOING. BOTH THE NAM AND RAP INDICATED DRYING TAKING PLACE WITHIN
THE BOUNDARY LAYER BY LATE AFTERNOON AND EARLY EVENING...WITH THE
PREDOMINANT CEILING SHIFTING UP TO AROUND 10KFT. SPORADIC GUSTS TO
AROUND 20KTS POSSIBLE THROUGH THE AFTERNOON WITH W/NW WINDS.
FAST MOVING UPPER LEVEL WAVE WILL TRACK THROUGH THE OHIO VALLEY
OVERNIGHT...SPREADING LIGHT SNOW ACROSS THE SOUTHERN HALF OF
CENTRAL INDIANA. SUBTLE PLACEMENT DIFFERENCE PRESENT AMONGST ALL
OF THE SHORT RANGE MODEL GUIDANCE...BUT CONFIDENCE IS HIGH IN
LIGHT SNOW IMPACTING KBMG/KHUF/KIND BEGINNING 04-05Z AND
PERSISTING THROUGH AROUND DAYBREAK. GREATEST IMPACT ANTICIPATED AT
KBMG WHERE IFR CONDITIONS ARE POSSIBLE WITHIN HEAVIER SNOWFALL.
SNOWFALL RATES WILL BE LIGHTER ALONG THE I-70 CORRIDOR...WITH
PRIMARILY MVFR CONDITIONS IMPACTING BOTH KHUF AND KIND. LIGHT
NORTHWEST WINDS EXPECTED OVERNIGHT.
LIGHT SNOW WILL MOVE OFF TO THE EAST QUICKLY TUESDAY MORNING WITH
STEADILY IMPROVING CONDITIONS AT ALL TERMINALS. CEILINGS SHOULD
MIX OUT TO A SCATTERED VFR CU/STRATOCU DECK BY EARLY AFTERNOON.
MAIN IMPACT TO TERMINALS ON TUESDAY WILL BE WINDS AS TIGHTENING
SURFACE PRESSURE GRADIENT AND INCREASING FLOW THROUGH THE BOUNDARY
LAYER WILL SUPPORT WINDY CONDITIONS BY LATE MORNING. SOUTHWEST
SUSTAINEDS WILL INCREASE TO 15-20KTS WITH GUSTS AT 25-30KTS FROM
15-16Z CONTINUING INTO THE AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TUCEK
NEAR TERM...TUCEK
SHORT TERM...TUCEK
LONG TERM....RYAN
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
255 PM EST MON DEC 9 2013
.UPDATE...
THE LONG TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 148 PM EST MON DEC 9 2013
SEVERAL WEAK WEATHER SYSTEMS AFFECT OUR REGION TODAY INTO MIDWEEK
WITH MORE SIGNIFICANT SYSTEM FOR THIS WEEKEND. COLD ARCTIC HIGH
PRESSURE TO RULE IN BETWEEN WITH TEMPERATURES REMAINING WELL BELOW
NORMAL THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 148 PM EST MON DEC 9 2013
CONCERN FOR TONIGHT IS SNOW/NO SNOW BOUNDARY AND HOW MUCH SNOW
WILL OCCUR. WILL NOT ISSUE ADVISORY FOR THIS BUT MAKE MENTION IN
HAZARDOUS WEATHER OUTLOOK AND SPECIAL WEATHER STATEMENT.
AS TAIL END OF FIRST WEAK SHORT WAVE EXITS GREAT LAKES THIS
AFTERNOON THE SECOND ONE OVER THE TX PANHANDLE REGION BEGINS TO
TAKE SHAPE AND AIM ON THE OHIO VALLEY. MODELS IN GOOD AGREEMENT ON
RAPID SPREAD OF NARROW SNOW BAND ENE ACROSS SOUTHERN AND CENTRAL
INDIANA SOUTH OF I-70 LATE EVENING AND OVERNIGHT...QUICKLY EXITING
BEFORE SUNRISE. THOUGH MOISTURE IS SOMEWHAT LIMITED...BRIEF
PERIOD OF DENDRITIC GROWTH MAXES OUT OVER SOUTHERN COUNTIES AND
WITH RATIOS NEAR 15 TO ONE...EXPECT SNOW AMOUNTS OVER ONE INCH BY
DAWN FROM VINCENNES TO BEDFORD-BLOOMINGTON...COLUMBUS AND SEYMOUR.
LOCAL TWO INCH AMOUNTS WILL LIKELY OCCUR. THE CUT-OFF FOR NO SNOW
WILL BE NEARLY PARALLEL AND JUST A BIT NORTH OF I-70 SO SOUTH SIDE
OF INDY METRO COULD SEE HALF INCH WHILE NORTH SIDE GETS JUST A
DUSTING.
CURRENT FORECAST TEMPS NOT BAD BUT WITH BRIEF PERIOD OF PARTIAL
CLEARING THIS EVENING...ESPECIALLY NORTHERN COUNTIES...HAVE
ADJUSTED TEMPS DOWN A COUPLE DEGREES BUT STILL 10-18F RANGE NW TO
SE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 148 PM EST MON DEC 9 2013
TONIGHT/S SYSTEM WILL BE RAPIDLY EXITING TUESDAY MORNING WITH
GUSTY WEST WINDS AND CLEARING SKIES DEVELOPING IN THE MORNING.
CURRENT MAX TEMPS IN LINE WITH LATEST DATA AND DESPITE SUNSHINE
EXPECT NO BETTER THAN MID TO UPPER 20S.
TUESDAY NIGHT...SKIES BEGIN TO CLOUD OVER ACROSS NORTHERN COUNTIES AS
CLIPPER SYSTEM AND ARCTIC FRONT SWEEPS INTO WESTERN GREAT LAKES BY
DAYBREAK WEDNESDAY. SOUTHERN COUNTIES REMAIN UNDER THE INFLUENCE
OF COLD HIGH PRESSURE AND MAINTAIN MOSTLY CLEAR SKIES. EXPECTING
SIMILAR LOWS WITH READINGS IN 10 TO 15F RANGE.
WEDNESDAY...CURRENTLY LOOKS LIKE THE QUICK CLIPPER SYSTEM/S
MEASUREABLE SNOWS WOULD REMAIN NORTH OF A LAFAYETTE TO MUNCIE LINE
AND EVEN THERE AMOUNTS SHOULD BE NO MORE THAN A DUSTING TO HALF
INCH. STRONG ARCTIC HIGH PRESSURE RAPIDLY CLEARS SKIES WEDNESDAY
AFTERNOON AND SETS STAGE FOR CLEAR SKY WEDNESDAY NIGHT WITH SINGLE
DIGIT LOWS AFTER SLOWLY FALLING TEMPS WEDNESDAY AFTERNOON.
HIGH PRESSURE SETTLING INTO THE TENNESSEE VALLEY THURSDAY BRINGS
RETURN FLOW TO SOUTHWEST BUT LITTLE MODERATION OF TEMPS UNDER
SUNNY SKIES. FORECAST MAX TEMPS UPPER TEENS TO LOWER 20S STILL
APPEAR LIKELY.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
ISSUED AT 255 PM EST MON DEC 9 2013
MAIN CHALLENGE FOR THE EXTENDED IS THE ARRIVAL AND IMPACT OF ANOTHER
POTENTIALLY MESSY WINTRY SYSTEM INTO THE OHIO VALLEY FRIDAY NIGHT
AND SATURDAY.
UPPER FLOW PATTERN WILL BRIEFLY TRANSITION FROM THE DEEP TROUGH TO
MORE OF A BROAD SOUTHWEST FLOW. AN UPPER WAVE WILL EJECT OUT OF
NORTHERN MEXICO ON FRIDAY AND QUICKLY TRACK INTO THE OHIO VALLEY BY
SATURDAY. A WEAK SURFACE WAVE WILL DEVELOP OVER THE SOUTHERN ROCKIES
AND MOVE INTO THE TENNESSEE VALLEY ON SATURDAY. THE MODEL
DIFFERENCES DEVELOP WITH RESPECT TO THE TIMING OF THE UPPER WAVE AND
THE STRENGTH OF THE SURFACE LOW. OP GFS CONTINUES TO HOLD THE UPPER
WAVE FURTHER WEST AND BRINGS A STRONGER SURFACE WAVE INTO THE REGION
SATURDAY...WHILE THE GLOBAL MODELS ARE MORE PROGRESSIVE ALOFT WITH A
WEAKER SURFACE WAVE TRACKING FURTHER TO THE SOUTH. THE TRACK AND
INTENSITY OF THE SURFACE WAVE WILL DETERMINE HOW MUCH WARM AIR
WITHIN THE BOUNDARY LAYER CAN BE ADVECTED NORTH INTO THE REGION LATE
FRIDAY NIGHT AND SATURDAY.
AT THIS POINT...AM LEANING TOWARDS THE COOLER GLOBAL MODELS WHICH
LIMIT ANY POTENTIAL MIXING OF PRECIP TO FAR SOUTHERN COUNTIES WHERE
CRITICAL LOW LEVEL THICKNESSES RISE TO AROUND 1305M FOR ABOUT 6-12
HOURS. SHOULD THIS COME TO PASS...SOUNDINGS WOULD SUPPORT FREEZING
RAIN AS THE PREDOMINANT TYPE LATE FRIDAY NIGHT INTO SATURDAY FOR
SEVERAL HOURS. WITH STILL PLENTY OF UNCERTAINTY AT THIS EARLY
STAGE...WILL CARRY A RA/SN MIX OVER THE FAR SOUTH WITH SNOW OVER THE
REST OF THE AREA. ENOUGH MOISTURE ACCOMPANYING THIS SYSTEM THAT
COULD SEE A FEW INCHES OF ACCUM FRIDAY NIGHT/SATURDAY IF PRECIP
REMAINS LARGELY IN THE FORM OF SNOW. WILL CERTAINLY BE KEEPING A
CLOSE EYE ON THE EVOLUTION OF THIS SYSTEM IN THE DAYS TO COME.
BEHIND THE SATURDAY STORM...COLDER AIR WILL ONCE AGAIN RETURN AS THE
POLAR VORTEX PINWHEELS THROUGH THE NORTHERN GREAT LAKES. HIGHS IN
THE 30S FRIDAY AND SATURDAY WILL FALL BACK INTO THE LOWER 20S BY
MONDAY WITH SINGLE DIGIT LOWS RETURNING EARLY NEXT WEEK.
&&
.AVIATION /DISCUSSION FOR 091800Z TAF ISSUANCE/...
ISSUED AT 1220 PM EST MON DEC 9 2013
MVFR CEILINGS WILL CONTINUE THIS AFTERNOON. MVFR/IFR CONDITIONS
POSSIBLE TONIGHT AT ALL SITES EXCEPT KLAF IN LIGHT SNOW.
STUBBORN STRATUS DECK HOLDING WITH MOISTURE TRAPPED UNDERNEATH THE
INVERSION..BUT BREAKS IN THE LOWER DECK ARE TRYING TO EXPAND EAST
INTO THE REGION. EXPECT MORE SUBSTANTIAL DEPARTURE OF THE STRATUS TO
TAKE MUCH OF THE AFTERNOON TO LIFT AND MIX OUT WITH COLD ADVECTION
ONGOING. BOTH THE NAM AND RAP INDICATED DRYING TAKING PLACE WITHIN
THE BOUNDARY LAYER BY LATE AFTERNOON AND EARLY EVENING...WITH THE
PREDOMINANT CEILING SHIFTING UP TO AROUND 10KFT. SPORADIC GUSTS TO
AROUND 20KTS POSSIBLE THROUGH THE AFTERNOON WITH W/NW WINDS.
FAST MOVING UPPER LEVEL WAVE WILL TRACK THROUGH THE OHIO VALLEY
OVERNIGHT...SPREADING LIGHT SNOW ACROSS THE SOUTHERN HALF OF
CENTRAL INDIANA. SUBTLE PLACEMENT DIFFERENCE PRESENT AMONGST ALL
OF THE SHORT RANGE MODEL GUIDANCE...BUT CONFIDENCE IS HIGH IN
LIGHT SNOW IMPACTING KBMG/KHUF/KIND BEGINNING 04-05Z AND
PERSISTING THROUGH AROUND DAYBREAK. GREATEST IMPACT ANTICIPATED AT
KBMG WHERE IFR CONDITIONS ARE POSSIBLE WITHIN HEAVIER SNOWFALL.
SNOWFALL RATES WILL BE LIGHTER ALONG THE I-70 CORRIDOR...WITH
PRIMARILY MVFR CONDITIONS IMPACTING BOTH KHUF AND KIND. LIGHT
NORTHWEST WINDS EXPECTED OVERNIGHT.
LIGHT SNOW WILL MOVE OFF TO THE EAST QUICKLY TUESDAY MORNING WITH
STEADILY IMPROVING CONDITIONS AT ALL TERMINALS. CEILINGS SHOULD
MIX OUT TO A SCATTERED VFR CU/STRATOCU DECK BY EARLY AFTERNOON.
MAIN IMPACT TO TERMINALS ON TUESDAY WILL BE WINDS AS TIGHTENING
SURFACE PRESSURE GRADIENT AND INCREASING FLOW THROUGH THE BOUNDARY
LAYER WILL SUPPORT WINDY CONDITIONS BY LATE MORNING. SOUTHWEST
SUSTAINEDS WILL INCREASE TO 15-20KTS WITH GUSTS AT 25-30KTS FROM
15-16Z CONTINUING INTO THE AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...TUCEK
NEAR TERM...TUCEK
SHORT TERM...TUCEK
LONG TERM....RYAN
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
223 PM EST MON DEC 9 2013
.UPDATE...
THE SYNOPSIS...NEAR TERM AND SHORT TERM SECTIONS HAVE BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 148 PM EST MON DEC 9 2013
SEVERAL WEAK WEATHER SYSTEMS AFFECT OUR REGION TODAY INTO MIDWEEK
WITH MORE SIGNIFICANT SYSTEM FOR THIS WEEKEND. COLD ARCTIC HIGH
PRESSURE TO RULE IN BETWEEN WITH TEMPERATURES REMAINING WELL BELOW
NORMAL THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /TONIGHT/...
ISSUED AT 148 PM EST MON DEC 9 2013
CONCERN FOR TONIGHT IS SNOW/NO SNOW BOUNDARY AND HOW MUCH SNOW
WILL OCCUR. WILL NOT ISSUE ADVISORY FOR THIS BUT MAKE MENTION IN
HAZARDOUS WEATHER OUTLOOK AND SPECIAL WEATHER STATEMENT.
AS TAIL END OF FIRST WEAK SHORT WAVE EXITS GREAT LAKES THIS
AFTERNOON THE SECOND ONE OVER THE TX PANHANDLE REGION BEGINS TO
TAKE SHAPE AND AIM ON THE OHIO VALLEY. MODELS IN GOOD AGREEMENT ON
RAPID SPREAD OF NARROW SNOW BAND ENE ACROSS SOUTHERN AND CENTRAL
INDIANA SOUTH OF I-70 LATE EVENING AND OVERNIGHT...QUICKLY EXITING
BEFORE SUNRISE. THOUGH MOISTURE IS SOMEWHAT LIMITED...BRIEF
PERIOD OF DENDRITIC GROWTH MAXES OUT OVER SOUTHERN COUNTIES AND
WITH RATIOS NEAR 15 TO ONE...EXPECT SNOW AMOUNTS OVER ONE INCH BY
DAWN FROM VINCENNES TO BEDFORD-BLOOMINGTON...COLUMBUS AND SEYMOUR.
LOCAL TWO INCH AMOUNTS WILL LIKELY OCCUR. THE CUT-OFF FOR NO SNOW
WILL BE NEARLY PARALLEL AND JUST A BIT NORTH OF I-70 SO SOUTH SIDE
OF INDY METRO COULD SEE HALF INCH WHILE NORTH SIDE GETS JUST A
DUSTING.
CURRENT FORECAST TEMPS NOT BAD BUT WITH BRIEF PERIOD OF PARTIAL
CLEARING THIS EVENING...ESPECIALLY NORTHERN COUNTIES...HAVE
ADJUSTED TEMPS DOWN A COUPLE DEGREES BUT STILL 10-18F RANGE NW TO
SE.
&&
.SHORT TERM /TUESDAY THROUGH THURSDAY/...
ISSUED AT 148 PM EST MON DEC 9 2013
TONIGHT/S SYSTEM WILL BE RAPIDLY EXITING TUESDAY MORNING WITH
GUSTY WEST WINDS AND CLEARING SKIES DEVELOPING IN THE MORNING.
CURRENT MAX TEMPS IN LINE WITH LATEST DATA AND DESPITE SUNSHINE
EXPECT NO BETTER THAN MID TO UPPER 20S.
TUESDAY NIGHT...SKIES BEGIN TO CLOUD OVER ACROSS NORTHERN COUNTIES AS
CLIPPER SYSTEM AND ARCTIC FRONT SWEEPS INTO WESTERN GREAT LAKES BY
DAYBREAK WEDNESDAY. SOUTHERN COUNTIES REMAIN UNDER THE INFLUENCE
OF COLD HIGH PRESSURE AND MAINTAIN MOSTLY CLEAR SKIES. EXPECTING
SIMILAR LOWS WITH READINGS IN 10 TO 15F RANGE.
WEDNESDAY...CURRENTLY LOOKS LIKE THE QUICK CLIPPER SYSTEM/S
MEASUREABLE SNOWS WOULD REMAIN NORTH OF A LAFAYETTE TO MUNCIE LINE
AND EVEN THERE AMOUNTS SHOULD BE NO MORE THAN A DUSTING TO HALF
INCH. STRONG ARCTIC HIGH PRESSURE RAPIDLY CLEARS SKIES WEDNESDAY
AFTERNOON AND SETS STAGE FOR CLEAR SKY WEDNESDAY NIGHT WITH SINGLE
DIGIT LOWS AFTER SLOWLY FALLING TEMPS WEDNESDAY AFTERNOON.
HIGH PRESSURE SETTLING INTO THE TENNESSEE VALLEY THURSDAY BRINGS
RETURN FLOW TO SOUTHWEST BUT LITTLE MODERATION OF TEMPS UNDER
SUNNY SKIES. FORECAST MAX TEMPS UPPER TEENS TO LOWER 20S STILL
APPEAR LIKELY.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 333 AM EST MON DEC 9 2013
MODEL ENSEMBLES INDICATE HIGH PRESSURE WILL BE ACROSS THE OHIO
VALLEY THURSDAY WHICH WILL MOVE ON TO THE EAST FRIDAY. A RETURN
FLOW ON THE BACK SIDE OF THE HIGH WILL BRING A SLIGHT MODERATION OF
TEMPERATURES BY FRIDAY. OVERALL ONLY MADE A FEW TWEAKS TO ALL BLEND
TEMPERATURES THURSDAY AND FRIDAY.
MODELS INDICATE A COUPLE OF UPPER DISTURBANCES IN THE SOUTHERN
STREAM WILL AFFECT OUR WEATHER FRIDAY NIGHT AND SATURDAY WITH LOW
PRESSURE DEVELOPING OVER TENNESSEE AND TRACKING TOWARDS THE CENTRAL
APPALACHIANS BY SATURDAY EVENING. MODELS HAVE ALSO TRENDED A LITTLE
WETTER FOR FRIDAY NIGHT AND SATURDAY. 1000-700 MB THICKNESS FAVOR
SNOW OVER THE NORTHERN HALF TO TWO THIRDS OF OUR REGION AND A WINTRY
MIX TO THE SOUTH. THIS SHOULD MOVE OUT SATURDAY NIGHT...BUT SOME
MODELS INDICATE TRACE PRECIP AMOUNTS MAY LINGER INTO SATURDAY
NIGHT...SO WILL ADD 20 PERCENT POPS MOST AREAS. THE GFS REMAINS DRY
ON SUNDAY WHILE THE EURO INDICATES POSSIBLE SNOW SHOWERS SOME AREAS
WITH A STRONGER UPPER LOW MOVING INTO THE GREAT LAKES. WITH POOR
AGREEMENT BETWEEN MODELS WILL KEEP EVERYTHING DRY FOR NOW ON SUNDAY.
IN REGARDS TO TEMPERATURES OVER THE WEEKEND...WENT A LITTLE ABOVE
ALL BLEND TEMPERATURES FRIDAY AND SATURDAY NIGHT DUE TO LOTS OF
CLOUDS AND A LITTLE COLDER SUNDAY TO PARTIALLY MATCH THE COLDER
TREND OF THE NEW EURO. IN MOST CASES THESE WERE ONLY MINOR TWEAK TO
ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR 091800Z TAF ISSUANCE/...
ISSUED AT 1220 PM EST MON DEC 9 2013
MVFR CEILINGS WILL CONTINUE THIS AFTERNOON. MVFR/IFR CONDITIONS
POSSIBLE TONIGHT AT ALL SITES EXCEPT KLAF IN LIGHT SNOW.
STUBBORN STRATUS DECK HOLDING WITH MOISTURE TRAPPED UNDERNEATH THE
INVERSION..BUT BREAKS IN THE LOWER DECK ARE TRYING TO EXPAND EAST
INTO THE REGION. EXPECT MORE SUBSTANTIAL DEPARTURE OF THE STRATUS TO
TAKE MUCH OF THE AFTERNOON TO LIFT AND MIX OUT WITH COLD ADVECTION
ONGOING. BOTH THE NAM AND RAP INDICATED DRYING TAKING PLACE WITHIN
THE BOUNDARY LAYER BY LATE AFTERNOON AND EARLY EVENING...WITH THE
PREDOMINANT CEILING SHIFTING UP TO AROUND 10KFT. SPORADIC GUSTS TO
AROUND 20KTS POSSIBLE THROUGH THE AFTERNOON WITH W/NW WINDS.
FAST MOVING UPPER LEVEL WAVE WILL TRACK THROUGH THE OHIO VALLEY
OVERNIGHT...SPREADING LIGHT SNOW ACROSS THE SOUTHERN HALF OF
CENTRAL INDIANA. SUBTLE PLACEMENT DIFFERENCE PRESENT AMONGST ALL
OF THE SHORT RANGE MODEL GUIDANCE...BUT CONFIDENCE IS HIGH IN
LIGHT SNOW IMPACTING KBMG/KHUF/KIND BEGINNING 04-05Z AND
PERSISTING THROUGH AROUND DAYBREAK. GREATEST IMPACT ANTICIPATED AT
KBMG WHERE IFR CONDITIONS ARE POSSIBLE WITHIN HEAVIER SNOWFALL.
SNOWFALL RATES WILL BE LIGHTER ALONG THE I-70 CORRIDOR...WITH
PRIMARILY MVFR CONDITIONS IMPACTING BOTH KHUF AND KIND. LIGHT
NORTHWEST WINDS EXPECTED OVERNIGHT.
LIGHT SNOW WILL MOVE OFF TO THE EAST QUICKLY TUESDAY MORNING WITH
STEADILY IMPROVING CONDITIONS AT ALL TERMINALS. CEILINGS SHOULD
MIX OUT TO A SCATTERED VFR CU/STRATOCU DECK BY EARLY AFTERNOON.
MAIN IMPACT TO TERMINALS ON TUESDAY WILL BE WINDS AS TIGHTENING
SURFACE PRESSURE GRADIENT AND INCREASING FLOW THROUGH THE BOUNDARY
LAYER WILL SUPPORT WINDY CONDITIONS BY LATE MORNING. SOUTHWEST
SUSTAINEDS WILL INCREASE TO 15-20KTS WITH GUSTS AT 25-30KTS FROM
15-16Z CONTINUING INTO THE AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...TUCEK
NEAR TERM...TUCEK
SHORT TERM...TUCEK
LONG TERM....JH
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1226 PM EST MON DEC 9 2013
.UPDATE...
THE NEAR TERM SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 AM EST MON DEC 9 2013
HIGH PRESSURE WILL BRIEFLY MOVE INTO THE AREA TODAY BUT ANOTHER
UPPER DISTURBANCE WILL PROVIDE A CHANCE FOR SNOW FOR PARTS OF
CENTRAL INDIANA TONIGHT AND EARLY TUESDAY. AN AREA OF LOW PRESSURE
WILL THEN BRING A SMALL CHANCE FOR SNOW TO OTHER PARTS OF THE AREA
WEDNESDAY. COLDER AIR WILL THEN FLOW IN FOR THURSDAY.
TEMPERATURES WILL MODERATE BY THE WEEKEND BUT YET ANOTHER SYSTEM
WILL BRING CHANCES FOR PRECIPITATION FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /THIS AFTERNOON/...
ISSUED AT 1221 PM EST MON DEC 9 2013
LOOKS LIKE BANDED LOW LEVEL CLOUDS THAT HAVE BEEN PRODUCING LIGHT
SNOW SHOWERS HAS DIMINISHED OVER CENTRAL INDIANA AND CURRENTLY
CONFINED TO NORTHERN INDIANA NE IL SO WILL END MENTION OF FLURRIES HERE.
SOME BREAKS IN CLOUDS AND BRIGHTENING OF SKY EXPECTED BUT OVERALL
MOSTLY CLOUDY WORDING STILL WORKS AND DESPITE BRIGHTER
SKIES...STRENGTH OF COLD ACROSS ILLINOIS SUGGESTS NO REAL WARMING
TO OCCUR. HAVE BUMPED WIND SPEEDS UP A TAD TO MATCH CURRENT OBS.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EST MON DEC 9 2013
FOCUS IS ON CHANCES FOR PRECIPITATION THROUGH THE PERIOD. MODELS ARE
IN DECENT AGREEMENT WITH THE BIG PICTURE SO USED A BLEND FOR MOST
PERIODS.
TONIGHT ISENTROPIC LIFT INCREASES ONCE AGAIN IN ADVANCE OF AN UPPER
WAVE. BEST FORCING AND MOISTURE LOOK TO BE CONFINED TO THE SOUTHERN
2/3 OF THE FORECAST AREA. THERE LOOKS TO BE SOME FRONTOGENETICAL
FORCING ACROSS MAINLY THE SOUTHERN HALF OF THE AREA AS WELL.
NAM IS FARTHEST NORTH WITH PRECIPITATION WITH OTHERS A BIT FARTHER
SOUTH. THIS LOOKS TO BE ANOTHER CASE WITH A VERY SHARP CUTOFF OF
POTENTIAL ACCUMULATING SNOW AND NO SNOW AT ALL. THUS CONFIDENCE IS
ONLY LOW TO MEDIUM IN NORTHERN PLACEMENT OF POPS...ESPECIALLY NORTH.
WILL GO DRY IN THE FAR NORTHWEST TONIGHT WITH A QUICK TRANSITION TO
HIGH CHANCE CATEGORY POPS SOUTH. IF NAM IS RIGHT WILL HAVE TO BUMP
TO LIKELY POPS ACROSS THE SOUTH WITH LATER FORECASTS. WILL CONTINUE
TO WATCH CLOSELY. POTENTIAL EXISTS FOR A QUICK INCH OR SO IN SOME
AREAS ACROSS THE SOUTH.
FORCING QUICKLY ENDS LATE TONIGHT INTO EARLY TUESDAY SO ONLY WENT
SLIGHT CHANCE POPS EARLY TUESDAY ACROSS THE FAR SOUTHEAST. OTHERWISE
CLOUDS WILL DECREASE TUESDAY AS SYSTEM EXITS. HOWEVER CLOUDS WILL
INCREASE ACROSS THE NORTH TUESDAY NIGHT AS THE NEXT SYSTEM
APPROACHES.
AN AREA OF LOW PRESSURE WILL MOVE ACROSS THE LOWER GREAT LAKES
WEDNESDAY. BEST FORCING AND MOISTURE REMAIN NORTH OF THE FORECAST
AREA...BUT LOOKS LIKE JUST ENOUGH MIGHT SNEAK INTO THE FAR NORTHERN
FORECAST AREA TO GO SLIGHT CHANCE POPS. DRY CONDITIONS WILL PREVAIL
WEDNESDAY NIGHT AS SYSTEM EXITS.
LOOKING AT TEMPERATURES...MAV LOOKS TOO COLD TONIGHT GIVEN EXPECTED
CLOUD COVER WITH NEXT SYSTEM. WENT CLOSER TO WARMER MET. ON TUESDAY
MAV LOOKS TOO WARM MANY AREAS GIVEN SOME COLD ADVECTION DURING PART
OF THE DAY. WENT CLOSER TO MET. AT OTHER TIMES USED A BLEND.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 333 AM EST MON DEC 9 2013
MODEL ENSEMBLES INDICATE HIGH PRESSURE WILL BE ACROSS THE OHIO
VALLEY THURSDAY WHICH WILL MOVE ON TO THE EAST FRIDAY. A RETURN
FLOW ON THE BACK SIDE OF THE HIGH WILL BRING A SLIGHT MODERATION OF
TEMPERATURES BY FRIDAY. OVERALL ONLY MADE A FEW TWEAKS TO ALL BLEND
TEMPERATURES THURSDAY AND FRIDAY.
MODELS INDICATE A COUPLE OF UPPER DISTURBANCES IN THE SOUTHERN
STREAM WILL AFFECT OUR WEATHER FRIDAY NIGHT AND SATURDAY WITH LOW
PRESSURE DEVELOPING OVER TENNESSEE AND TRACKING TOWARDS THE CENTRAL
APPALACHIANS BY SATURDAY EVENING. MODELS HAVE ALSO TRENDED A LITTLE
WETTER FOR FRIDAY NIGHT AND SATURDAY. 1000-700 MB THICKNESS FAVOR
SNOW OVER THE NORTHERN HALF TO TWO THIRDS OF OUR REGION AND A WINTRY
MIX TO THE SOUTH. THIS SHOULD MOVE OUT SATURDAY NIGHT...BUT SOME
MODELS INDICATE TRACE PRECIP AMOUNTS MAY LINGER INTO SATURDAY
NIGHT...SO WILL ADD 20 PERCENT POPS MOST AREAS. THE GFS REMAINS DRY
ON SUNDAY WHILE THE EURO INDICATES POSSIBLE SNOW SHOWERS SOME AREAS
WITH A STRONGER UPPER LOW MOVING INTO THE GREAT LAKES. WITH POOR
AGREEMENT BETWEEN MODELS WILL KEEP EVERYTHING DRY FOR NOW ON SUNDAY.
IN REGARDS TO TEMPERATURES OVER THE WEEKEND...WENT A LITTLE ABOVE
ALL BLEND TEMPERATURES FRIDAY AND SATURDAY NIGHT DUE TO LOTS OF
CLOUDS AND A LITTLE COLDER SUNDAY TO PARTIALLY MATCH THE COLDER
TREND OF THE NEW EURO. IN MOST CASES THESE WERE ONLY MINOR TWEAK TO
ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR 091800Z TAF ISSUANCE/...
ISSUED AT 1220 PM EST MON DEC 9 2013
MVFR CEILINGS WILL CONTINUE THIS AFTERNOON. MVFR/IFR CONDITIONS
POSSIBLE TONIGHT AT ALL SITES EXCEPT KLAF IN LIGHT SNOW.
STUBBORN STRATUS DECK HOLDING WITH MOISTURE TRAPPED UNDERNEATH THE
INVERSION..BUT BREAKS IN THE LOWER DECK ARE TRYING TO EXPAND EAST
INTO THE REGION. EXPECT MORE SUBSTANTIAL DEPARTURE OF THE STRATUS TO
TAKE MUCH OF THE AFTERNOON TO LIFT AND MIX OUT WITH COLD ADVECTION
ONGOING. BOTH THE NAM AND RAP INDICATED DRYING TAKING PLACE WITHIN
THE BOUNDARY LAYER BY LATE AFTERNOON AND EARLY EVENING...WITH THE
PREDOMINANT CEILING SHIFTING UP TO AROUND 10KFT. SPORADIC GUSTS TO
AROUND 20KTS POSSIBLE THROUGH THE AFTERNOON WITH W/NW WINDS.
FAST MOVING UPPER LEVEL WAVE WILL TRACK THROUGH THE OHIO VALLEY
OVERNIGHT...SPREADING LIGHT SNOW ACROSS THE SOUTHERN HALF OF
CENTRAL INDIANA. SUBTLE PLACEMENT DIFFERENCE PRESENT AMONGST ALL
OF THE SHORT RANGE MODEL GUIDANCE...BUT CONFIDENCE IS HIGH IN
LIGHT SNOW IMPACTING KBMG/KHUF/KIND BEGINNING 04-05Z AND
PERSISTING THROUGH AROUND DAYBREAK. GREATEST IMPACT ANTICIPATED AT
KBMG WHERE IFR CONDITIONS ARE POSSIBLE WITHIN HEAVIER SNOWFALL.
SNOWFALL RATES WILL BE LIGHTER ALONG THE I-70 CORRIDOR...WITH
PRIMARILY MVFR CONDITIONS IMPACTING BOTH KHUF AND KIND. LIGHT
NORTHWEST WINDS EXPECTED OVERNIGHT.
LIGHT SNOW WILL MOVE OFF TO THE EAST QUICKLY TUESDAY MORNING WITH
STEADILY IMPROVING CONDITIONS AT ALL TERMINALS. CEILINGS SHOULD
MIX OUT TO A SCATTERED VFR CU/STRATOCU DECK BY EARLY AFTERNOON.
MAIN IMPACT TO TERMINALS ON TUESDAY WILL BE WINDS AS TIGHTENING
SURFACE PRESSURE GRADIENT AND INCREASING FLOW THROUGH THE BOUNDARY
LAYER WILL SUPPORT WINDY CONDITIONS BY LATE MORNING. SOUTHWEST
SUSTAINEDS WILL INCREASE TO 15-20KTS WITH GUSTS AT 25-30KTS FROM
15-16Z CONTINUING INTO THE AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...TUCEK
SHORT TERM...50
LONG TERM....JH
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
WWW.TWITTER.COM/NWSINDIANAPOLIS
WWW.YOUTUBE.COM/NWSINDIANAPOLIS
AREA FORECAST DISCUSSION
NWS INDIANAPOLIS IN
1220 PM EST MON DEC 9 2013
.UPDATE...
THE AVIATION SECTION HAS BEEN UPDATED BELOW.
&&
.SYNOPSIS...
ISSUED AT 337 AM EST MON DEC 9 2013
HIGH PRESSURE WILL BRIEFLY MOVE INTO THE AREA TODAY BUT ANOTHER
UPPER DISTURBANCE WILL PROVIDE A CHANCE FOR SNOW FOR PARTS OF
CENTRAL INDIANA TONIGHT AND EARLY TUESDAY. AN AREA OF LOW PRESSURE
WILL THEN BRING A SMALL CHANCE FOR SNOW TO OTHER PARTS OF THE AREA
WEDNESDAY. COLDER AIR WILL THEN FLOW IN FOR THURSDAY.
TEMPERATURES WILL MODERATE BY THE WEEKEND BUT YET ANOTHER SYSTEM
WILL BRING CHANCES FOR PRECIPITATION FRIDAY NIGHT INTO SATURDAY.
&&
.NEAR TERM /TODAY/...
ISSUED AT 919 AM EST MON DEC 9 2013
INTRODUCING FLURRIES INTO FORECAST THROUGH MID AFTERNOON GIVEN
WEAK RADAR RETURNS COUPLED WITH SURFACE OBSERVED LIGHT SNOW
OCCURRING. DO NOT EXPECT ACCUMULATION THOUGH GIVEN NO VSBY DROP
ACCOMPANYING CURRENT SNOW AND FLAKES QUITE SMALL.
CLEARING ACROSS WC AND NW IL SHOULD WORK ITS WAY INTO WESTERN
COUNTIES BY LATE AFTERNOON AS HIGH PRESSURE BUILDS IN BUT RETURN
OF HIGH CLOUDS FROM SOUTHERN SYSTEMS APPROACH TO RETURN HIGHER
DECKS BY NIGHTFALL.
TEMPS TO HOLD FAIRLY STEADY THROUGH THE DAY GIVEN CLOUD DECK
HOLDING AND COLD ADVECTION BEGINNING TO TAKE PLACE.
&&
.SHORT TERM /TONIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 337 AM EST MON DEC 9 2013
FOCUS IS ON CHANCES FOR PRECIPITATION THROUGH THE PERIOD. MODELS ARE
IN DECENT AGREEMENT WITH THE BIG PICTURE SO USED A BLEND FOR MOST
PERIODS.
TONIGHT ISENTROPIC LIFT INCREASES ONCE AGAIN IN ADVANCE OF AN UPPER
WAVE. BEST FORCING AND MOISTURE LOOK TO BE CONFINED TO THE SOUTHERN
2/3 OF THE FORECAST AREA. THERE LOOKS TO BE SOME FRONTOGENETICAL
FORCING ACROSS MAINLY THE SOUTHERN HALF OF THE AREA AS WELL.
NAM IS FARTHEST NORTH WITH PRECIPITATION WITH OTHERS A BIT FARTHER
SOUTH. THIS LOOKS TO BE ANOTHER CASE WITH A VERY SHARP CUTOFF OF
POTENTIAL ACCUMULATING SNOW AND NO SNOW AT ALL. THUS CONFIDENCE IS
ONLY LOW TO MEDIUM IN NORTHERN PLACEMENT OF POPS...ESPECIALLY NORTH.
WILL GO DRY IN THE FAR NORTHWEST TONIGHT WITH A QUICK TRANSITION TO
HIGH CHANCE CATEGORY POPS SOUTH. IF NAM IS RIGHT WILL HAVE TO BUMP
TO LIKELY POPS ACROSS THE SOUTH WITH LATER FORECASTS. WILL CONTINUE
TO WATCH CLOSELY. POTENTIAL EXISTS FOR A QUICK INCH OR SO IN SOME
AREAS ACROSS THE SOUTH.
FORCING QUICKLY ENDS LATE TONIGHT INTO EARLY TUESDAY SO ONLY WENT
SLIGHT CHANCE POPS EARLY TUESDAY ACROSS THE FAR SOUTHEAST. OTHERWISE
CLOUDS WILL DECREASE TUESDAY AS SYSTEM EXITS. HOWEVER CLOUDS WILL
INCREASE ACROSS THE NORTH TUESDAY NIGHT AS THE NEXT SYSTEM
APPROACHES.
AN AREA OF LOW PRESSURE WILL MOVE ACROSS THE LOWER GREAT LAKES
WEDNESDAY. BEST FORCING AND MOISTURE REMAIN NORTH OF THE FORECAST
AREA...BUT LOOKS LIKE JUST ENOUGH MIGHT SNEAK INTO THE FAR NORTHERN
FORECAST AREA TO GO SLIGHT CHANCE POPS. DRY CONDITIONS WILL PREVAIL
WEDNESDAY NIGHT AS SYSTEM EXITS.
LOOKING AT TEMPERATURES...MAV LOOKS TOO COLD TONIGHT GIVEN EXPECTED
CLOUD COVER WITH NEXT SYSTEM. WENT CLOSER TO WARMER MET. ON TUESDAY
MAV LOOKS TOO WARM MANY AREAS GIVEN SOME COLD ADVECTION DURING PART
OF THE DAY. WENT CLOSER TO MET. AT OTHER TIMES USED A BLEND.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
ISSUED AT 333 AM EST MON DEC 9 2013
MODEL ENSEMBLES INDICATE HIGH PRESSURE WILL BE ACROSS THE OHIO
VALLEY THURSDAY WHICH WILL MOVE ON TO THE EAST FRIDAY. A RETURN
FLOW ON THE BACK SIDE OF THE HIGH WILL BRING A SLIGHT MODERATION OF
TEMPERATURES BY FRIDAY. OVERALL ONLY MADE A FEW TWEAKS TO ALL BLEND
TEMPERATURES THURSDAY AND FRIDAY.
MODELS INDICATE A COUPLE OF UPPER DISTURBANCES IN THE SOUTHERN
STREAM WILL AFFECT OUR WEATHER FRIDAY NIGHT AND SATURDAY WITH LOW
PRESSURE DEVELOPING OVER TENNESSEE AND TRACKING TOWARDS THE CENTRAL
APPALACHIANS BY SATURDAY EVENING. MODELS HAVE ALSO TRENDED A LITTLE
WETTER FOR FRIDAY NIGHT AND SATURDAY. 1000-700 MB THICKNESS FAVOR
SNOW OVER THE NORTHERN HALF TO TWO THIRDS OF OUR REGION AND A WINTRY
MIX TO THE SOUTH. THIS SHOULD MOVE OUT SATURDAY NIGHT...BUT SOME
MODELS INDICATE TRACE PRECIP AMOUNTS MAY LINGER INTO SATURDAY
NIGHT...SO WILL ADD 20 PERCENT POPS MOST AREAS. THE GFS REMAINS DRY
ON SUNDAY WHILE THE EURO INDICATES POSSIBLE SNOW SHOWERS SOME AREAS
WITH A STRONGER UPPER LOW MOVING INTO THE GREAT LAKES. WITH POOR
AGREEMENT BETWEEN MODELS WILL KEEP EVERYTHING DRY FOR NOW ON SUNDAY.
IN REGARDS TO TEMPERATURES OVER THE WEEKEND...WENT A LITTLE ABOVE
ALL BLEND TEMPERATURES FRIDAY AND SATURDAY NIGHT DUE TO LOTS OF
CLOUDS AND A LITTLE COLDER SUNDAY TO PARTIALLY MATCH THE COLDER
TREND OF THE NEW EURO. IN MOST CASES THESE WERE ONLY MINOR TWEAK TO
ALL BLEND TEMPERATURES.
&&
.AVIATION /DISCUSSION FOR 091800Z TAF ISSUANCE/...
ISSUED AT 1220 PM EST MON DEC 9 2013
MVFR CEILINGS WILL CONTINUE THIS AFTERNOON. MVFR/IFR CONDITIONS
POSSIBLE TONIGHT AT ALL SITES EXCEPT KLAF IN LIGHT SNOW.
STUBBORN STRATUS DECK HOLDING WITH MOISTURE TRAPPED UNDERNEATH THE
INVERSION..BUT BREAKS IN THE LOWER DECK ARE TRYING TO EXPAND EAST
INTO THE REGION. EXPECT MORE SUBSTANTIAL DEPARTURE OF THE STRATUS TO
TAKE MUCH OF THE AFTERNOON TO LIFT AND MIX OUT WITH COLD ADVECTION
ONGOING. BOTH THE NAM AND RAP INDICATED DRYING TAKING PLACE WITHIN
THE BOUNDARY LAYER BY LATE AFTERNOON AND EARLY EVENING...WITH THE
PREDOMINANT CEILING SHIFTING UP TO AROUND 10KFT. SPORADIC GUSTS TO
AROUND 20KTS POSSIBLE THROUGH THE AFTERNOON WITH W/NW WINDS.
FAST MOVING UPPER LEVEL WAVE WILL TRACK THROUGH THE OHIO VALLEY
OVERNIGHT...SPREADING LIGHT SNOW ACROSS THE SOUTHERN HALF OF
CENTRAL INDIANA. SUBTLE PLACEMENT DIFFERENCE PRESENT AMONGST ALL
OF THE SHORT RANGE MODEL GUIDANCE...BUT CONFIDENCE IS HIGH IN
LIGHT SNOW IMPACTING KBMG/KHUF/KIND BEGINNING 04-05Z AND
PERSISTING THROUGH AROUND DAYBREAK. GREATEST IMPACT ANTICIPATED AT
KBMG WHERE IFR CONDITIONS ARE POSSIBLE WITHIN HEAVIER SNOWFALL.
SNOWFALL RATES WILL BE LIGHTER ALONG THE I-70 CORRIDOR...WITH
PRIMARILY MVFR CONDITIONS IMPACTING BOTH KHUF AND KIND. LIGHT
NORTHWEST WINDS EXPECTED OVERNIGHT.
LIGHT SNOW WILL MOVE OFF TO THE EAST QUICKLY TUESDAY MORNING WITH
STEADILY IMPROVING CONDITIONS AT ALL TERMINALS. CEILINGS SHOULD
MIX OUT TO A SCATTERED VFR CU/STRATOCU DECK BY EARLY AFTERNOON.
MAIN IMPACT TO TERMINALS ON TUESDAY WILL BE WINDS AS TIGHTENING
SURFACE PRESSURE GRADIENT AND INCREASING FLOW THROUGH THE BOUNDARY
LAYER WILL SUPPORT WINDY CONDITIONS BY LATE MORNING. SOUTHWEST
SUSTAINEDS WILL INCREASE TO 15-20KTS WITH GUSTS AT 25-30KTS FROM
15-16Z CONTINUING INTO THE AFTERNOON.
&&
.IND WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SYNOPSIS...50
NEAR TERM...TUCEK
SHORT TERM...50
LONG TERM....JH
AVIATION...RYAN
VISIT US AT HTTP://WWW.WEATHER.GOV/IND
FOLLOW US ON TWITTER AND YOUTUBE AT:
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AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
435 PM EST MON DEC 9 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY NIGHT)
ISSUED AT 435 PM EST MON DEC 9 2013
20Z SFC ANALYSIS SHOWS THE ARCTIC BOUNDARY HOLDING ON JUST TO OUR
SOUTHEAST AWAITING THE NEXT WAVE OF PCPN TO MOVE UP ALONG IT FROM THE
SOUTH. LOW CLOUDS ARE FOUND THROUGH MOST OF EAST KENTUCKY WITH JUST
SOME SMALL BREAKS RIGHT ALONG THE SPINE OF THE APPALACHIANS. UNDER
THESE AND CLOSER TO THE FRONT...TEMPERATURES ARE SIGNIFICANTLY
MILDER THAN THE REST OF THE AREA. AS A RESULT...READINGS RANGE FROM
THE MID AND UPPER 40S NEAR VIRGINIA TO THE LOW 30S NORTH OF
INTERSTATE 64. DEWPOINTS...MEANWHILE...ARE IN THE UPPER 20S
NORTHWEST TO LOWER 40S IN THE FAR SOUTHEAST.
THE MODELS REMAIN IN SOME FLUX...STILL AT THIS LATE HOUR...REGARDING
THE TANDEM MID LEVEL WAVES THAT WILL CROSS THE OHIO VALLEY ON
TUESDAY. THE SOUTHERN ONE WILL HAVE THE MOST IMPACT ON THE AREA LATER
TONIGHT BUT MAY NOT COMPLETELY PHASE WITH THE CLIPPER COMING IN FROM
THE NORTH. BECAUSE OF THIS...THE RESULTING WEATHER HAS BEEN SHIFTING
IN THE MODEL SOLUTIONS WITH EACH RUN. REGARDLESS...THE COMBINED
TROUGH WILL SWEEP THROUGH THE OHIO VALLEY AND CENTRAL APPALACHIANS BY
00Z WEDNESDAY WITH FAST...FLAT FLOW TO FOLLOW. A GENERAL MODEL BLEND
WAS USED FOR THE FORECAST WITH THE 12Z NAM AND GFS TAKING THE LEAD...
ALTHOUGH THE HRRR WAS ALSO INCLUDED FOR THE PCPN ONSET AND TYPE
EARLY.
SENSIBLE WEATHER WILL FEATURE A QUICK HIT OF PCPN AS THE LAST SFC
WAVE MOVES NORTHEAST ALONG THE TIGHTENING ARCTIC BOUNDARY JUST TO
OUR SOUTHEAST. EXPECT THE PCPN TO MOVE BACK IN AROUND MIDNIGHT
STARTING ALONG THE TENNESSEE BORDER IN THE FAR SOUTHWEST AND QUICKLY
SPREADING NORTHEAST WITH TIME. THE LATEST MODELS ARE TARGETING THE
SOUTHEAST 2/3RDS OF THE CWA FOR A QUARTER INCH OR SO OF QPF AND
LIGHTER AMOUNTS TAPERING QUICKLY TO THE NORTHWEST. THE NORTHERN
PORTION OF THIS HYBRID CLIPPER/WAVE WILL LIKELY HAVE HIGHER SNOW
RATIOS TO COMPENSATE FOR THE LESSER QPF THERE. ACROSS THE FAR
SOUTHEAST...THERE WILL BE A BETTER CHANCE OF SLEET MIXING IN WITH THE
SNOW AT THE ONSET SO HAVE CUT THE SNOW AMOUNTS IN THIS AREA. THE SNOW
WILL LIKELY COME DOWN QUICK FOR SEVERAL HOURS ACROSS THE AREA RIGHT
BEFORE THE MORNING-SCHOOL COMMUTE. ACCORDINGLY...WE HAVE HOISTED A
WSW FROM MIDNIGHT THROUGH THE MORNING ACROSS THE AREA...LINGERING THE
ADVISORY IN THE FAR SOUTHEAST THROUGH MID AFTERNOON TUESDAY. THE SNOW
PULLS AWAY QUICKLY AND DRIER AIR BEHIND THE FINALLY DEPARTING ARCTIC
BOUNDARY WILL CLEAR THE SKY AND POPS SETTING THE STAGE FOR A VERY
COLD NIGHT INTO WEDNESDAY MORNING.
USED THE CONSSHORT TO BASE THE TEMPS AND TD ON THROUGH 18Z TUESDAY...
CONSALL THEREAFTER...WHILE ALLOWING THE DIURNAL FROM THE NAM12 TO
GUIDE THE HOURLY TEMPS THROUGH THE SHORT TERM...TOO. BCCONSSHORT WAS
USED AS A STARTING POINT FOR WINDS THROUGH 18Z AND THE BCCONSALL
AFTER THAT. AS FOR POPS...ENDED UP CLOSEST TO THE SLIGHTLY HIGHER MET
NUMBERS ACROSS THE AREA TONIGHT INTO TUESDAY AND BASICALLY KEPT
THINGS DRY ON TUESDAY NIGHT.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 257 PM EST MON DEC 9 2013
MODELS ARE IN REASONABLE AGREEMENT THROUGH THE WEEK AND INTO THE
UPCOMING WEEKEND WITH ONLY SOME SMALL DIFFERENCES. CONFIDENCE IS
INCREASING AROUND THE UPCOMING STORM FOR FRIDAY NIGHT AND SATURDAY.
HIGH PRESSURE WILL FINALLY MAKE A RETURN FOR WEDNESDAY WITH A FULL
DAY OF SUNSHINE. A FAST MOVING VORT MAX WILL TEMPORARILY SUPPRESS
THE HIGH TO THE SOUTH AS IT PUSHES A COLD FRONT ACROSS EASTERN
KENTUCKY. MOISTURE REMAINS VERY LIMITED WITH THIS FEATURE AND AT
BEST A PERIOD OF FLURRIES COULD OCCUR. HIGH PRESSURE WILL REBUILD
OVER THE AREA FROM THURSDAY INTO FRIDAY. A SHARP MID LEVEL TROUGH
WILL EJECT OUT OF THE SOUTHWEST FRIDAY NIGHT INTO SATURDAY...WITH A
SURFACE LOW TRACKING ACROSS THE REGION. RIGHT NOW IT LOOKS LIKE THE
TRACK SHOULD TAKE IT RIGHT OVER SOUTHEAST KENTUCKY WITH THE WARM
SECTOR SURGING INTO THE AREA LATE FRIDAY NIGHT. WHILE A PERIOD OF
SNOW/SLEET MAY BE POSSIBLE AT THE ONSET...ESPECIALLY ACROSS THE
NORTH...WE SHOULD SEE A QUICK TRANSITION OVER TO ALL RAIN. RAIN WILL
CONTINUE INTO SATURDAY. AS THE SYSTEM DEPARTS...COLD AIR WILL WRAP
BACK INTO EASTERN KENTUCKY WITH PRECIPITATION CHANGING OVER TO SNOW
SATURDAY NIGHT. AT THIS TIME...MOISTURE AND LIFT APPEARS TO BE
FAIRLY LIMITED WITH UPSLOPE FLOW...SO ANY ACCUMULATIONS WILL LIKELY
BE SMALL AND MAYBE CONFINED TO JUST THE HIGHER ELEVATIONS.
DRIER...BUT COLDER WEATHER WILL THEN BE SEEN INTO EARLY NEXT WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 205 PM EST MON DEC 9 2013
ALTHOUGH DRIER AIR IS FILTERING INTO THE AREA CIGS ARE STILL QUITE
LOW. HAVE LIMITED THEIR RECOVER TO LATE THIS AFTERNOON AND EARLY THIS
EVENING. CONFIDENCE IN THE DETAILS OF SNOW DEVELOPING ACROSS THE
AREA OVERNIGHT HAS INCREASED WITH BETTER MODEL AGREEMENT.
ACCORDINGLY...HAVE HIT ALL THE TAFS WITH A PERIOD OF SNOW...LOW
CIGS...AND VIS FROM SOMETIME AFTER MIDNIGHT UNTIL JUST AFTER DAWN ON
TUESDAY. EXPECT CONDITIONS TO IMPROVE BUT CIGS WILL PROBABLY BE
MVFR INTO THE FIRST PART OF THE AFTERNOON. WINDS WILL BE WEST TO
NORTHWEST THROUGH THE PERIOD AT 5 TO 10 KTS...BUT DURING ANY HEAVIER
BOUTS OF SNOW THERE MAY BE A BRIEF PICK UP WITH GUSTS TO 15 KTS OR
SO.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON EST
TUESDAY FOR KYZ044-050>052.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM EST
TUESDAY FOR KYZ058>060-068-069-079-080-083-084-104-106>109-111-
112-114.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EST
TUESDAY FOR KYZ085>088-110-113-115>120.
&&
$$
SHORT TERM...GREIF
LONG TERM...KAS
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
427 PM EST MON DEC 9 2013
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 426 PM EST MON DEC 9 2013
WV IMAGERY AND RUC ANALYSIS INDICATED A BROAD TROUGH ACROSS NOAM.
ONE SHORTWAVE TROUGH EXTENDED FROM NW ONTARIO THROUGH WRN LAKE
SUPERIOR WHILE ANOTHER UPSTREAM SHRTWV WAS MOVING FROM SE SASK
TOWARD THE NRN PLAINS. AT THE SFC...A WEAK RIDGE OVER WRN MN
SEPARATED LOWS NE OF LAKE SUPERIOR AND OVER NE MONTANA. WSW WINDS
ACROSS WRN LAKE SUPERIOR WERE SLOWLY VEERING AS THE SHRTWV ADVANCES
THROUGH THE AREA. THE INITIAL DOMINANT BAND THROUGH THE NRN KEWEENAW
EARLY THIS AFTERNOON HAD LIFTED BACK TO THE NORTH.
HOWEVER...MULTIPLE WIND PARALLEL BANDS INTO THE NRN HALF OF THE
KEWEENAW HAVE INTENSIFIED THIS AFTERNOON...AIDED BY THE SHRTWV WHICH
HAS BOOSTED INVERSION HEIGHTS TO AROUND 9K FT AS 850 MB TEMPS DROP
INTO THE -18C TO -21C RANGE.
TONIGHT...
THE HIGH RES MODELS WERE IN GOOD AGREEMENT AND SUPPORT
UPSTREAM TRENDS OF LOW LEVEL WINDS VEERING THIS EVENING WHICH SHOULD
PUSH HEAVY LES BANDS OVER THE KEWEENAW GRADUALLY TO THE SOUTH.
HOWEVER...THE SRN EXTENT OF THE LES IS EXPECTED TO REMAIN MAINLY
NORTH OF M-38. SLR VALUES MAY BE LIMITED BY THE VERY COLD INCOMING
ARCTIC AIRMASS WHICH WILL KEEP THE DGZ BELOW 2K FT. GIVEN THE
FAVORABLE LOW LEVEL CONV PERSISTING THROUGH MUCH OF THE EVENING
BEFORE WINDS BACK AHEAD OF THE NEXT SHORTWAVE...ADDITIONAL
ACCUMULATIONS IN THE 3 TO 6 INCH RANGE ARE LIKELY. BY 12Z...EXPECT
THAT THE HEAVIER LES SHOULD LIFT TOWARD EAGLE RIVER AND COPPER
HARBOR BEFORE MOVING OFFHSORE TUE MORNING. STRONG WRLY GUSTING TO 35
MPH WILL ALSO CAUSE SIGNIFICANT BLOWING AND DRIFTING IN OPEN AREAS
WITH VSBY AOB 1/4SM IN THE HEAVIER LES BANDS BEFORE TAPER OFF AFTER
03Z/TUE.
TEMPERATURES DROPPING INTO THE ZERO TO 10 BELOW RANGE WITH WINDS OF
10 TO 15 MPH MAY DROP WIND CHILL VALUES TO 15 BELOW TO 25 BELOW THIS
EVENING. HOWEVER...WINDS ARE EXPECTED TO DIMINISH TO 7 MPH OR LESS
OVER THE COLDER INLAND AREAS...KEEPING WIND CHILLS FROM REACHING
ADVISORY THRESHOLD. IN ADDITION...CLOUDS WILL THICKEN LATE AS THE
SHRTWV APPROACHES BRINGING SLOWLY CLIMBING TEMPS LATE.
TUESDAY...
THE SASK SHRTWV WILL MOVE THROUGH THE REGION WITH MODERATE TO STRONG
700-300 MB QVECTOR CONV. EVEN THOUGH THE STRONGEST FORCING IS
EXPECTED JUST TO THE SOUTH OF UPPER MICHIGAN...IT SHOULD STILL BE
STRONG ENOUGH OVER UPPER MI TO SQUEEZE OUT SOME LIGHT SNOW WITH A
FEW HUNDREDTHS QPF IN THE VERY DRY AIRMASS. OVERALL ACCUMULATIONS
SHOULD REMAIN BELOW A HALF INCH BUT SHOULD BE WIDESPREAD ENOUGH TO
INCLUDE LIKELY POPS. VEERING WINDS IN THE WAKE OF THE SHRTWV SHOULD
BRING ANOTHER STRONG AREA OF LOW LEVEL CONV INTO NW UPPER MI AS THE
SFC TROUGH MOVES THROUGH AROUND 18Z. ANOTHER PERIOD OF HEAVIER LES
IS EXPECTED WITH THIS FEATURE THAT COULD PRODUCE 2 TO 4 INCHES OF
SNOW. SINCE THERE IS A GAP BETWEEN THE MON NIGHT LES AND THE NEXT
BATCH THE HEADLINE WAS NOT EXTENDED AT THIS TIME.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 416 PM EST MON DEC 9 2013
COLD TEMPERATURES AND LAKE EFFECT SNOW WILL DOMINATE MUCH OF THE
LONG TERM FORECAST.
A SHORTWAVE AND WEAK LOW PRESSURE SYSTEM SLIDING ACROSS NORTHERN
WISCONSIN AND SOUTHERN UPPER MICHIGAN TONIGHT INTO TUESDAY MORNING
WILL PROVIDE A REINFORCING SHOT OF COLD AIR TO THE AREA FOR TUESDAY
NIGHT INTO WEDNESDAY. MEANWHILE...HIGH PRESSURE WILL BEGIN TO BUILD
INTO THE NORTHERN PLAINS BEFORE SINKING SOUTHEAST INTO THE MID
MISSISSIPPI VALLEY FOR WEDNESDAY NIGHT. MODELS ARE FAIRLY
CONSISTENT ON A SURFACE TROUGH LINGERING OVER CENTRAL/EASTERN LAKE
SUPERIOR ON THE BACK SIDE OF THE LOW TUESDAY EVENING AND THEN
SHIFTING SOUTHEAST WEDNESDAY MORNING. THIS LINGERING TROUGH WILL
LIKELY LEAD TO A LAKE INDUCED LOW DEVELOPING OVER THE FAR EASTERN
LAKE WEDNESDAY NIGHT AND REMAINING INTO THURSDAY AS A HIGH
PRESSURE RIDGE MOVES OVER SOUTHERN UPPER MICHIGAN.
OVERALL...CONDITIONS CONTINUE TO BE VERY FAVORABLE FOR LAKE EFFECT
SNOWFALL INTO THURSDAY...WITH 850MB TEMPS FALLING FROM AROUND -21C
AT 00Z WEDNESDAY TO -24C ON WEDNESDAY AFTERNOON. THIS STRONG OVER
LAKE INSTABILITY (LAKE TEMPS AROUND 2-3C) WILL LEAD TO FAIRLY HIGH
EQUILIBRIUM LEVELS (12/15KFT WEST/EAST) AND LAKE INDUCED CAPE
VALUES EXCEEDING 800-1000J/KG FOR TUESDAY NIGHT INTO WEDNESDAY. LES
WILL BE AIDED ON TUESDAY NIGHT BY LINGERING MOISTURE FROM THE
CLIPPER SYSTEM...ALLOWING THE STRONGER BANDS TO REALIZE THE HIGHER
INVERSION HEIGHTS. BUT AS THAT DEEPER MOISTURE DEPARTS THROUGH THE
NIGHT AND INTO WEDNESDAY MORNING...EXPECT A TRANSITION TO PURE LAKE
EFFECT AND THE LOSS OF THE DEEPER MOISTURE MAY LIMIT THE WEAKER
BANDS FROM REACHING THE HIGHER INVERSION HEIGHTS. LAKE EFFECT SNOW
PARAMETER REALLY HIGHLIGHTS LUCE COUNTY FOR TUESDAY NIGHT INTO
WEDNESDAY MORNING...BEFORE VALUES BEGIN TO FALL TO MORE MODERATE
LAKE EFFECT VALUES DURING THE DAY AS THE 850MB TEMPERATURES COOL.
THE REST OF THE AREA LOOKS TO SEE LOW END MODERATE VALUES DUE TO THE
AMOUNT OF COLD AIR. AS FOR SNOW RATIOS...HAVE GENERALLY KEPT VALUES
AROUND 20-1 AT THIS POINT...SINCE MUCH OF THE FORCING WILL BE AT
THE HIGH END OR ABOVE THE DGZ. THINK THE HIGHEST RATIOS WILL BE
INITIALLY TUESDAY NIGHT BEFORE THE COLDER AIR ARRIVES AND SHOVES
THE DGZ TOWARDS THE SURFACE. THOSE HIGHER RATIOS MAY BE LIMITED
SOMEWHAT BY STRONGER WINDS RIGHT BEHIND THE FRONT LEADING TO
FRACTURING OF THE DENDRITES TO GO ALONG WITH MAINLY COLUMNS. BUT
THOSE WINDS SHOULD WEAKEN SLIGHTLY INTO WEDNESDAY AND ALLOW THE
LIMITED DENDRITES TO REMAIN TOGETHER.
WITH CONDITIONS APPEARING GOOD FOR LES...WINDS WILL DETERMINE THE
BAND PLACEMENT. EXPECT THE LAKE EFFECT TO BE IN THE WESTERLY FLOW
AREAS TO START THE LONG TERM PERIOD...BUT AS THE SURFACE TROUGH
DIVES SOUTHEAST...EXPECT BANDS TO SHIFT SOUTH AND SETUP IN THE MORE
WEST-NORTHWEST TO NORTHWEST WIND LOCATIONS BY WEDNESDAY MORNING.
EXPECT THE HEAVIEST SNOW OVER NORTHERN LUCE COUNTY WHERE THERE WILL
BE INCREASED CONVERGENCE FROM THE TROUGH AND HAVE THE LONGEST FETCH
ACROSS THE LAKE. SOME DIFFERENCES IN THE TIMING THAT THE DOMINATE
BAND MOVES SOUTH INTO NORTHERN LUCE COUNTY...BUT LOOKS TO BE
THROUGH THE EVENING HOURS AND THEN REMAINING THROUGH MUCH OF
WEDNESDAY AND WEDNESDAY NIGHT BEFORE FINALLY SHIFTING NORTH ON
THURSDAY DUE TO A RIDGE MOVING INTO THE SOUTHERN U.P. WITH THE
POTENTIAL FOR HEAVY SNOW AND A PROLONGED EVENT (CURRENT FORECAST OF
1-2FT IN FAR NE LUCE COUNTY BY THURSDAY MORNING)...OPTED TO ISSUE A
LAKE EFFECT SNOW WATCH FOR LUCE COUNTY. ALGER COUNTY IS A LITTLE
MORE UNCERTAIN...AS IT DEPENDS ON HOW FAR SOUTHWEST THE BAND SINKS.
BEST OPPORTUNITY WOULD BE NEAR GRAND MARAIS. NAM IS MOST AGGRESSIVE
WITH THE SOUTHWEST PUSH...WHILE MOST OF THE OTHER MODELS KEEP WINDS
OUT OF THE WNW TO WESTERLY DIRECTION. THUS...HAVE LEFT THEM OUT OF
ANY PRODUCTS AT THIS TIME AND HOPEFULLY WE/LL BE ABLE TO PIN DOWN
THE SOUTHWEST EXTENT IN THE NEXT 24HRS.
FARTHER WEST...EXPECT THE HEAVIEST SNOW IN THE WNW FAVORED AREAS
FROM ONTONAGON THROUGH THE KEWEENAW. WITH HE SURFACE TROUGH LIKELY
SETUP ACROSS ONTONAGON COUNTY...WOULD EXPECT THERE TO BE SOME SORT
OF DOMINATE BAND AND THE HIGHEST SNOWFALL AMOUNTS THERE. AT THIS
POINT...HAVE AMOUNTS AN INCH OR TWO UNDER WARNING CRITERIA AND WILL
NOT ISSUE A WATCH. SHOULD BE A SOLID ADVISORY AND THERE IS THE
POTENTIAL FOR SOME LOCATIONS TO REACH WARNING AMOUNTS.
OTHERWISE...EXPECT GENERAL MODERATE LAKE EFFECT SNOW NORTH OF THE
TROUGH OVER THE KEWEENAW WITH ADVISORY CRITERIA ACCUMULATIONS. SINCE
THERE IS A WARNING OUT FOR THOSE AREAS...WILL HOLD OFF NOW AND
LET MID SHIFT PUT UP ADVISORIES ALL AT ONCE.
WITH THE HIGH MOVING INTO THE MID MISSISSIPPI VALLEY AND A RIDGE
SLIDING INTO SOUTHERN UPPER MICHIGAN LATE WEDNESDAY AFTERNOON
AND THROUGH THE NIGHT...EXPECT WINDS TO BACK TO MORE OF A WESTERLY
(OR EVEN SOUTHWESTERLY DIRECTION OVER WESTERN LAKE SUPERIOR). THIS
WILL PUSH THE LAKE EFFECT SNOW BACK TO THE NORTH THROUGH THE NIGHT
AND INTO THURSDAY. THE FOCUS WILL REMAIN OVER THE KEWEENAW AND THE
FAR NORTHEAST PART OF LUCE COUNTY DURING THAT TIME. INVERSION
HEIGHTS DO LOOK TO LOWER DURING THIS PERIOD TO 5-7KFT...SO
WOULD EXPECT THE INTENSITY AND AMOUNTS TO DIMINISH AS THE DGZ
LOWERS TO THE SURFACE. FINALLY...ANOTHER WEAK CLIPPER LOOKS TO
MOVE THROUGH LATE WEDNESDAY NIGHT INTO THURSDAY MORNING BUT WILL
LIKELY BE SOUTH THAN THE ONE TONIGHT AND MOVE THROUGH
CENTRAL/SOUTHERN WISCONSIN.
IN ADDITION TO THE LAKE EFFECT SNOW...COLD TEMPERATURES WILL REMAIN
OVER THE AREA THROUGH THURSDAY...WHICH WILL LEAD TO SOME CONCERNS
FOR WIND CHILL ADVISORIES ON TUESDAY/WEDNESDAY NIGHT. OVERNIGHT
LOWS WILL BE IN THE SINGLE DIGITS BELOW ZERO ON TUESDAY NIGHT AND
THEN POTENTIALLY 10 DEGREES COLDER ON WEDNESDAY NIGHT. THERE IS
SOME CONCERN FOR CLOUDS AHEAD OF THE CLIPPER SYSTEM ON WEDNESDAY
NIGHT...WHICH COULD LEAD TO SOME RISING TEMPERATURES TOWARDS
MORNING. WIND CHILLS WILL DEPEND ON HOW MUCH DECOUPLING WILL OCCUR
AND TUESDAY NIGHT WILL LIKELY SEE WINDS STAYING UP MORE WITH THE
TIGHT GRADIENT BETWEEN THE HIGH MOVING INTO THE NORTHERN PLAINS AND
THE TROUGH OVER EASTERN LAKE SUPERIOR. THIS WILL PRODUCE
WIND CHILL VALUES IN THE -20S OVER THE INTERIOR WEST AND A
DECENT CHANCE OF A WIND CHILL ADVISORY. ON WEDNESDAY NIGHT THE
SURFACE RIDGE WILL BE MOVING IN AND LEADING TO LIGHT WINDS
OVERNIGHT. THESE LIGHT WINDS WILL ALLOW FOR LOWER TEMPS (IF THE
CLOUDS STAY TO THE SOUTHWEST) BUT ALSO LIMIT WIND CHILL VALUES...BUT
STILL EXPECT THEM IN THE -25 TO -34 DEGREE F RANGE.
FOR FRIDAY TO NEXT MONDAY...THE GENERAL TREND IN THE MODELS IS FOR
THE UPPER TROUGH TO SHIFT EAST THURSDAY NIGHT AND FRIDAY...LEADING
TO SOME MODERATION OF THE COLDER AIR AS THE FLOW ALOFT BECOMES
WESTERLY. THEN...AS THE SOUTHERN STREAM TROUGH MOVES INTO THE
SOUTHEAST CONUS THIS WEEKEND...ANOTHER STRONG SHORTWAVE WILL DIVE
SOUTHEAST IN THE NORTHERN STREAM AND LEAD TO ANOTHER PERIOD OF COLD
WEATHER FOR SUNDAY AND THE START OF NEXT WEEK. MODELS STILL VARY ON
THE EXACT SOLUTION AND TIMING AS THE DISTURBANCES PHASE OVER THE
EASTERN CONUS...BUT THE GENERAL IDEA IS A SURFACE TROUGH
SETTING UP OVER THE UPPER GREAT LAKES (STRETCHING NORTHWEST
FROM THE LOW MOVING UP THE EAST COAST) FOR MUCH OF THE WEEKEND
BEFORE DIVING SOUTHEAST ON SUNDAY NIGHT AND MONDAY WITH THE
NORTHERN STREAM SHORTWAVE. MOISTURE ASSOCIATED WITH THE TROUGH...
850MB TEMPS AROUND -22C AND LIKELY LIGHT NORTHERLY WINDS
SUPPORTS HAVING SLIGHT/CHANCE POPS OVER MUCH OF THE
AREA...ESPECIALLY IN THE NORTH TO NORTHEAST FAVORED LOCATIONS NEAR
LAKE SUPERIOR. THIS NORTHERLY FLOW WILL LIKELY LEAD TO SOME LES FOR
AREAS THAT HAVE BEEN MISSED BY THE LES AT THE END OF LAST WEEK AND
THIS WEEK. SINCE THERE IS CONSISTENCY IN THE MODELS THIS
WEEKEND...WILL TREND POPS UP IN THE NORTHERLY WIND AREAS FRIDAY
NIGHT INTO SUNDAY AND BEGIN TO HIGHLIGHT IN THE HWO/EHWO.
HIGH PRESSURE WILL LIKELY BUILD INTO THE UPPER GREAT LAKES ON
MONDAY AFTERNOON...ALTHOUGH THERE ARE HINTS OF ANOTHER SHORTWAVE
DIVING INTO THE UPPER MISSISSIPPI VALLEY FOR MONDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 117 PM EST MON DEC 9 2013
KIWD...EXPECT MVFR CIGS AND -SN IN WSW FLOW THROUGH MUCH OF THIS AFTERNOON.
CONDITIONS SHOULD IMPROVE TO VFR THIS EVENING AS WINDS BACK MORE SW.
MVFR CONDITIONS IN LIGHT SNOW RETURN LATE TONIGHT WITH APPROACH OF
NEXT DISTURBANCE THE NOTRHERN PLAINS.
KCMX...IFR CONDITIONS WILL LOWER TO LIFR/VLIFR VSBY IN MODERATE TO
HEAVY LAKE EFFECT SNOW THIS AFTERNOON AS WSW WINDS VEER TO THE W AND
BECOME GUSTY. THIS WILL CONTINUE INTO THE EVENING HOURS BUT SHOULD
IMPROVE BY LATE EVENING. CONDITIONS WILL IMPROVE AGAIN TO MVFR LATE
TONIGHT AS THE HEAVIER LES BANDS SHIFT NORTH OF THE AREA.
KSAW...MVFR CIGS THIS AFTERNOON ARE EXPECTED THAT WILL LIFT BACK TO
VFR AS A DISTUBANCE MOVES TO THE EAST OF THE AREA. THE NEXT
SHORTWAVE TROUGH MOVING INTO THE AREA TUE MORNING WILL BRING ANOTHER
PERIOD OF MVFR CIGS WITH SOME LIGHT SNOW SHOWERS OR FLURRIES.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 426 PM EST MON DEC 9 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES FOR GALES. THE FIRST TROUGH MOVING
THROUGH LATE THIS AFTERNOON WILL BRING WRLY GALES OF
35 TO 40 KNOTS ACROSS LAKE SUPERIOR LATE THIS AFTERNOON AND EVENING.
AFTER A DECREASE TO 20 TO 30 KNOT SOUTHWEST WINDS TUESDAY
MORNING...ANOTHER LOW PRESSURE WILL TRACK EASTWARD ACROSS LAKE
SUPERIOR ON TUESDAY AND COULD PRODUCE GALE FORCE WIND GUSTS TO 35
KNOTS BEHIND IT TUESDAY AFTERNOON AND EVENING. THE WESTERLY WINDS
WILL WEAKEN SLIGHTLY TO 20 TO 30 KNOTS FROM LATE TUESDAY NIGHT INTO
THURSDAY AS A WEAK RIDGE EXTENDING FROM HIGH PRESSURE IN THE CENTRAL
PLAINS SLOWLY BUILDS INTO THE AREA. CONTINUED MODERATE TO HEAVY
FREEZING SPRAY WILL BE POSSIBLE THROUGHOUT THE PERIOD WITH SEVERAL
PUSHES OF ARCTIC AIR ACROSS THE LAKE. ANOTHER WEAK LOW PRESSURE
SYSTEM WILL MOVE SOUTHEASTWARD ACROSS LAKE SUPERIOR THURSDAY NIGHT
INTO FRIDAY...BUT WINDS SHOULD REMAIN UNDER 20 KNOTS THROUGH
SATURDAY BEHIND THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR MIZ001-003.
LAKE EFFECT SNOW WATCH FROM TUESDAY EVENING THROUGH THURSDAY
MORNING FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 10 AM EST TUESDAY FOR LSZ245-
248>251-265>267.
GALE WARNING UNTIL 1 AM EST TUESDAY FOR LSZ244-245-248>251-
264>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ TUESDAY
FOR LSZ162-240>244-263-264.
GALE WARNING UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR
LSZ241>243-246-247.
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR LSZ263.
LAKE MICHIGAN...
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LMZ221-248-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...JLB
MARINE...JLB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
417 PM EST MON DEC 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 551 AM EST MON DEC 9 2013
WV IMAGERY AND RUC ANALYSIS STILL SHOWING A BROAD MID/UPPER LEVEL
TROUGH OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO
THE GREAT LAKES. THERE ARE SEVERAL SHORTWAVES OF NOTE FOR THE SHORT
TERM.
ONE SHORTWAVE MOVING ACROSS LAKE MI INTO LOWER MI AND ITS
ASSOC SFC LOW PRODUCED LIGHT SNOW ACROSS THE CWA LAST NIGHT INTO THE
EARLY MORNING. MOST OF THE AREA RECEIVED GENERALLY NO MORE THAN AN
INCH OF SYSTEM SNOW...ALTHOUGH SOME LOCATIONS ALONG LAKE MI LIKELY
RECEIVED 2 TO LOCALLY 4 INCHES OF SNOW DUE TO LAKE ENHANCEMENT OF
SNOW OFF LAKE MI. MQT RADAR WAS SHOWING A MORE PROMINENT BAND OF
LAKE ENHANCED SNOW FROM NEAR COOKS/MANISTIQUE AREA NORTH TO
SHINGLETON IN THE PAST FEW HOURS ALTHOUGH IT LOOKS LIKE THIS BAND
MAY BE WEAKENING NOW AS BEST FORCING FOR ENHANCEMENT APPEARS TO BE
LIFTING EAST WITH THE SHORTWAVE. DUE TO ISOLATED NATURE OF THIS
BAND DECIDED TO ONLY KEEP WINTER WX ADVISORY GOING FOR ONLY
SCHOOLCRAFT COUNTY THRU 14Z AND DROPPED ADVISORY FOR MNM-DELTA AND
LUCE WHERE SNOW HAS BEEN VERY LIGHT AND APPEARS TO BE
DIMINISHING.
TODAY AND TONIGHT...THE MAIN SHORTWAVE OF CONCERN FOR THIS FCST PD
IS IMMEDIATELY UPSTREAM OVER THE NRN PLAINS AND WILL BE PUSHING
THROUGH THE UPPER GREAT LAKES LATE THIS MORNING AND AFTERNOON. THE
NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE WESTERN CWA
BEHIND A COLD FRONT AT THE START OF THE PERIOD. MODELS INDICATE 850
MB TEMPS FALLING TO -20 TO -23C BY THE AFTERNOON COMBINED WITH
INVERSION HEIGHTS RISING TO 8-10KFT AND UNIDIRECTIONAL WESTERLY
WINDS RESULTING IN FAVORABLE LOW LEVEL CONV AND THE LIKELYHOOD OF A
DOMINANT LES BAND IMPACTING THE KEWEENAW PENINSULA. WITH THE PASSAGE
OF THE SHRTWV...EXPECT WINDS WOULD VEER FROM WSW TO MORE DUE
W...PUSHING THE DOMINANT BAND SLOWLY TO THE SOUTH FROM NEAR EAGLE
RIVER TO CALUMET/MOHAWK AND TO HOUGHTON THIS AFTERNOON AND TO POINTS
SOUTH OF HOUGHTON THIS EVENING. SNOWFALL ACCUMULATIONS WILL GREATLY
DEPEND ON HOW LONG THE HEAVIER BAND LINGERS IN ANY ONE
LOCATION...ACCUMULATIONS OF 6-10 INCHES REMAIN VERY LIKELY LATE THIS
MORNING THROUGH TONIGHT. IN ADDITION...BLUSTERY WEST WINDS OF
20-30MPH WITH GUSTS OVER 35 MPH WILL PRODUCE CONSIDERABLE BLOWING
AND DRIFTING SNOW AND NEAR WHITEOUT CONDITIONS WHERE THE DOMINANT
BAND SETS UP. HOWEVER...SINCE MOST OF THE 00Z AND 06Z LOCAL AND
REGIONAL HIGHER RES MODELS STILL INDICATE THAT THE DOMINANT BAND
WILL BE GRADUALLY MOVING SOUTH ACROSS THE KEWEENAW PENINSULA FROM
LATE MORNING THROUGH THE AFTERNOON HRS...FELT RELUCTANT TO UPGRADE
TO A WARNING AS AMOUNTS MAY BE SOMEWHAT LIMITED DUE TO TRANSIENT
NATURE OF BAND. I AM ALSO A LITTLE CONCERNED THAT BEST ENHANCEMENT
POTENTIAL FOR DOMINANT LES BAND WILL ARRIVE AHEAD OF THE SHORTWAVE
AND JUST BEFORE WINDS BEGIN TO VEER FROM WSW TO W SO THERE IS A
CHANCE THAT THE DOMINANT BAND MAY BE STRONGEST OUT OVER THE WATER
BEFORE IT REALLY MOVES ONSHORE TO THE KEWEENAW. DUE TO ABOVE
REASONING...DECIDED TO KEEP THE ADVISORY GOING BUT KEPT IN STRONGER
WORDING OF OCCASIONAL HEAVY SNOW AND CONSIDERABLE BLOWING
SNOW/LOCALIZED WHITEOUT CONDITONS IN WSW STATEMENT UNDER THE DOMINANT
BAND...STRESSING DIFFICULT TRAVEL AT TIMES DUE TO POOR VISIBILITY AND
BLOWING/DRIFTING SNOW. SOME OF THE HIGHER RES MODELS PARTICULARLY THE
LOCAL WRF-ARW INDICATE THAT DOMINANT COULD GET PUSHED SOUTH OF
HOUGHTON FOR A TIME THIS EVENING AND PERHAPS EVEN AFFECT NE ONTONAGON
AND NRN BARAGA COUNTIES BEFORE SHIFTING BACK ACROSS THE NRN PORTION
OF KEWEENAW OVERNIGHT AS WINDS BACK WSW AGAIN IN RESPONSE TO SFC RDG
BUILDING IN FM THE WEST.
THE REST OF THE CWA WILL FEEL THE EFFECT OF THE BITTER COLD AIR
FLOODING THE REGION. MAY FLIRT WITH WIND CHILL ADVISORY CRITERIA OF
25 BLO ZERO OR COLDER TONIGHT OVER THE WEST HALF INTERIOR OF THE CWA
AS ACTUAL TEMPS PLUMMET INTO THE DOUBLE DIGITS BLO ZERO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 416 PM EST MON DEC 9 2013
COLD TEMPERATURES AND LAKE EFFECT SNOW WILL DOMINATE MUCH OF THE
LONG TERM FORECAST.
A SHORTWAVE AND WEAK LOW PRESSURE SYSTEM SLIDING ACROSS NORTHERN
WISCONSIN AND SOUTHERN UPPER MICHIGAN TONIGHT INTO TUESDAY MORNING
WILL PROVIDE A REINFORCING SHOT OF COLD AIR TO THE AREA FOR TUESDAY
NIGHT INTO WEDNESDAY. MEANWHILE...HIGH PRESSURE WILL BEGIN TO BUILD
INTO THE NORTHERN PLAINS BEFORE SINKING SOUTHEAST INTO THE MID
MISSISSIPPI VALLEY FOR WEDNESDAY NIGHT. MODELS ARE FAIRLY
CONSISTENT ON A SURFACE TROUGH LINGERING OVER CENTRAL/EASTERN LAKE
SUPERIOR ON THE BACK SIDE OF THE LOW TUESDAY EVENING AND THEN
SHIFTING SOUTHEAST WEDNESDAY MORNING. THIS LINGERING TROUGH WILL
LIKELY LEAD TO A LAKE INDUCED LOW DEVELOPING OVER THE FAR EASTERN
LAKE WEDNESDAY NIGHT AND REMAINING INTO THURSDAY AS A HIGH
PRESSURE RIDGE MOVES OVER SOUTHERN UPPER MICHIGAN.
OVERALL...CONDITIONS CONTINUE TO BE VERY FAVORABLE FOR LAKE EFFECT
SNOWFALL INTO THURSDAY...WITH 850MB TEMPS FALLING FROM AROUND -21C
AT 00Z WEDNESDAY TO -24C ON WEDNESDAY AFTERNOON. THIS STRONG OVER
LAKE INSTABILITY (LAKE TEMPS AROUND 2-3C) WILL LEAD TO FAIRLY HIGH
EQUILIBRIUM LEVELS (12/15KFT WEST/EAST) AND LAKE INDUCED CAPE
VALUES EXCEEDING 800-1000J/KG FOR TUESDAY NIGHT INTO WEDNESDAY. LES
WILL BE AIDED ON TUESDAY NIGHT BY LINGERING MOISTURE FROM THE
CLIPPER SYSTEM...ALLOWING THE STRONGER BANDS TO REALIZE THE HIGHER
INVERSION HEIGHTS. BUT AS THAT DEEPER MOISTURE DEPARTS THROUGH THE
NIGHT AND INTO WEDNESDAY MORNING...EXPECT A TRANSITION TO PURE LAKE
EFFECT AND THE LOSS OF THE DEEPER MOISTURE MAY LIMIT THE WEAKER
BANDS FROM REACHING THE HIGHER INVERSION HEIGHTS. LAKE EFFECT SNOW
PARAMETER REALLY HIGHLIGHTS LUCE COUNTY FOR TUESDAY NIGHT INTO
WEDNESDAY MORNING...BEFORE VALUES BEGIN TO FALL TO MORE MODERATE
LAKE EFFECT VALUES DURING THE DAY AS THE 850MB TEMPERATURES COOL.
THE REST OF THE AREA LOOKS TO SEE LOW END MODERATE VALUES DUE TO THE
AMOUNT OF COLD AIR. AS FOR SNOW RATIOS...HAVE GENERALLY KEPT VALUES
AROUND 20-1 AT THIS POINT...SINCE MUCH OF THE FORCING WILL BE AT
THE HIGH END OR ABOVE THE DGZ. THINK THE HIGHEST RATIOS WILL BE
INITIALLY TUESDAY NIGHT BEFORE THE COLDER AIR ARRIVES AND SHOVES
THE DGZ TOWARDS THE SURFACE. THOSE HIGHER RATIOS MAY BE LIMITED
SOMEWHAT BY STRONGER WINDS RIGHT BEHIND THE FRONT LEADING TO
FRACTURING OF THE DENDRITES TO GO ALONG WITH MAINLY COLUMNS. BUT
THOSE WINDS SHOULD WEAKEN SLIGHTLY INTO WEDNESDAY AND ALLOW THE
LIMITED DENDRITES TO REMAIN TOGETHER.
WITH CONDITIONS APPEARING GOOD FOR LES...WINDS WILL DETERMINE THE
BAND PLACEMENT. EXPECT THE LAKE EFFECT TO BE IN THE WESTERLY FLOW
AREAS TO START THE LONG TERM PERIOD...BUT AS THE SURFACE TROUGH
DIVES SOUTHEAST...EXPECT BANDS TO SHIFT SOUTH AND SETUP IN THE MORE
WEST-NORTHWEST TO NORTHWEST WIND LOCATIONS BY WEDNESDAY MORNING.
EXPECT THE HEAVIEST SNOW OVER NORTHERN LUCE COUNTY WHERE THERE WILL
BE INCREASED CONVERGENCE FROM THE TROUGH AND HAVE THE LONGEST FETCH
ACROSS THE LAKE. SOME DIFFERENCES IN THE TIMING THAT THE DOMINATE
BAND MOVES SOUTH INTO NORTHERN LUCE COUNTY...BUT LOOKS TO BE
THROUGH THE EVENING HOURS AND THEN REMAINING THROUGH MUCH OF
WEDNESDAY AND WEDNESDAY NIGHT BEFORE FINALLY SHIFTING NORTH ON
THURSDAY DUE TO A RIDGE MOVING INTO THE SOUTHERN U.P. WITH THE
POTENTIAL FOR HEAVY SNOW AND A PROLONGED EVENT (CURRENT FORECAST OF
1-2FT IN FAR NE LUCE COUNTY BY THURSDAY MORNING)...OPTED TO ISSUE A
LAKE EFFECT SNOW WATCH FOR LUCE COUNTY. ALGER COUNTY IS A LITTLE
MORE UNCERTAIN...AS IT DEPENDS ON HOW FAR SOUTHWEST THE BAND SINKS.
BEST OPPORTUNITY WOULD BE NEAR GRAND MARAIS. NAM IS MOST AGGRESSIVE
WITH THE SOUTHWEST PUSH...WHILE MOST OF THE OTHER MODELS KEEP WINDS
OUT OF THE WNW TO WESTERLY DIRECTION. THUS...HAVE LEFT THEM OUT OF
ANY PRODUCTS AT THIS TIME AND HOPEFULLY WE/LL BE ABLE TO PIN DOWN
THE SOUTHWEST EXTENT IN THE NEXT 24HRS.
FARTHER WEST...EXPECT THE HEAVIEST SNOW IN THE WNW FAVORED AREAS
FROM ONTONAGON THROUGH THE KEWEENAW. WITH HE SURFACE TROUGH LIKELY
SETUP ACROSS ONTONAGON COUNTY...WOULD EXPECT THERE TO BE SOME SORT
OF DOMINATE BAND AND THE HIGHEST SNOWFALL AMOUNTS THERE. AT THIS
POINT...HAVE AMOUNTS AN INCH OR TWO UNDER WARNING CRITERIA AND WILL
NOT ISSUE A WATCH. SHOULD BE A SOLID ADVISORY AND THERE IS THE
POTENTIAL FOR SOME LOCATIONS TO REACH WARNING AMOUNTS.
OTHERWISE...EXPECT GENERAL MODERATE LAKE EFFECT SNOW NORTH OF THE
TROUGH OVER THE KEWEENAW WITH ADVISORY CRITERIA ACCUMULATIONS. SINCE
THERE IS A WARNING OUT FOR THOSE AREAS...WILL HOLD OFF NOW AND
LET MID SHIFT PUT UP ADVISORIES ALL AT ONCE.
WITH THE HIGH MOVING INTO THE MID MISSISSIPPI VALLEY AND A RIDGE
SLIDING INTO SOUTHERN UPPER MICHIGAN LATE WEDNESDAY AFTERNOON
AND THROUGH THE NIGHT...EXPECT WINDS TO BACK TO MORE OF A WESTERLY
(OR EVEN SOUTHWESTERLY DIRECTION OVER WESTERN LAKE SUPERIOR). THIS
WILL PUSH THE LAKE EFFECT SNOW BACK TO THE NORTH THROUGH THE NIGHT
AND INTO THURSDAY. THE FOCUS WILL REMAIN OVER THE KEWEENAW AND THE
FAR NORTHEAST PART OF LUCE COUNTY DURING THAT TIME. INVERSION
HEIGHTS DO LOOK TO LOWER DURING THIS PERIOD TO 5-7KFT...SO
WOULD EXPECT THE INTENSITY AND AMOUNTS TO DIMINISH AS THE DGZ
LOWERS TO THE SURFACE. FINALLY...ANOTHER WEAK CLIPPER LOOKS TO
MOVE THROUGH LATE WEDNESDAY NIGHT INTO THURSDAY MORNING BUT WILL
LIKELY BE SOUTH THAN THE ONE TONIGHT AND MOVE THROUGH
CENTRAL/SOUTHERN WISCONSIN.
IN ADDITION TO THE LAKE EFFECT SNOW...COLD TEMPERATURES WILL REMAIN
OVER THE AREA THROUGH THURSDAY...WHICH WILL LEAD TO SOME CONCERNS
FOR WIND CHILL ADVISORIES ON TUESDAY/WEDNESDAY NIGHT. OVERNIGHT
LOWS WILL BE IN THE SINGLE DIGITS BELOW ZERO ON TUESDAY NIGHT AND
THEN POTENTIALLY 10 DEGREES COLDER ON WEDNESDAY NIGHT. THERE IS
SOME CONCERN FOR CLOUDS AHEAD OF THE CLIPPER SYSTEM ON WEDNESDAY
NIGHT...WHICH COULD LEAD TO SOME RISING TEMPERATURES TOWARDS
MORNING. WIND CHILLS WILL DEPEND ON HOW MUCH DECOUPLING WILL OCCUR
AND TUESDAY NIGHT WILL LIKELY SEE WINDS STAYING UP MORE WITH THE
TIGHT GRADIENT BETWEEN THE HIGH MOVING INTO THE NORTHERN PLAINS AND
THE TROUGH OVER EASTERN LAKE SUPERIOR. THIS WILL PRODUCE
WIND CHILL VALUES IN THE -20S OVER THE INTERIOR WEST AND A
DECENT CHANCE OF A WIND CHILL ADVISORY. ON WEDNESDAY NIGHT THE
SURFACE RIDGE WILL BE MOVING IN AND LEADING TO LIGHT WINDS
OVERNIGHT. THESE LIGHT WINDS WILL ALLOW FOR LOWER TEMPS (IF THE
CLOUDS STAY TO THE SOUTHWEST) BUT ALSO LIMIT WIND CHILL VALUES...BUT
STILL EXPECT THEM IN THE -25 TO -34 DEGREE F RANGE.
FOR FRIDAY TO NEXT MONDAY...THE GENERAL TREND IN THE MODELS IS FOR
THE UPPER TROUGH TO SHIFT EAST THURSDAY NIGHT AND FRIDAY...LEADING
TO SOME MODERATION OF THE COLDER AIR AS THE FLOW ALOFT BECOMES
WESTERLY. THEN...AS THE SOUTHERN STREAM TROUGH MOVES INTO THE
SOUTHEAST CONUS THIS WEEKEND...ANOTHER STRONG SHORTWAVE WILL DIVE
SOUTHEAST IN THE NORTHERN STREAM AND LEAD TO ANOTHER PERIOD OF COLD
WEATHER FOR SUNDAY AND THE START OF NEXT WEEK. MODELS STILL VARY ON
THE EXACT SOLUTION AND TIMING AS THE DISTURBANCES PHASE OVER THE
EASTERN CONUS...BUT THE GENERAL IDEA IS A SURFACE TROUGH
SETTING UP OVER THE UPPER GREAT LAKES (STRETCHING NORTHWEST
FROM THE LOW MOVING UP THE EAST COAST) FOR MUCH OF THE WEEKEND
BEFORE DIVING SOUTHEAST ON SUNDAY NIGHT AND MONDAY WITH THE
NORTHERN STREAM SHORTWAVE. MOISTURE ASSOCIATED WITH THE TROUGH...
850MB TEMPS AROUND -22C AND LIKELY LIGHT NORTHERLY WINDS
SUPPORTS HAVING SLIGHT/CHANCE POPS OVER MUCH OF THE
AREA...ESPECIALLY IN THE NORTH TO NORTHEAST FAVORED LOCATIONS NEAR
LAKE SUPERIOR. THIS NORTHERLY FLOW WILL LIKELY LEAD TO SOME LES FOR
AREAS THAT HAVE BEEN MISSED BY THE LES AT THE END OF LAST WEEK AND
THIS WEEK. SINCE THERE IS CONSISTENCY IN THE MODELS THIS
WEEKEND...WILL TREND POPS UP IN THE NORTHERLY WIND AREAS FRIDAY
NIGHT INTO SUNDAY AND BEGIN TO HIGHLIGHT IN THE HWO/EHWO.
HIGH PRESSURE WILL LIKELY BUILD INTO THE UPPER GREAT LAKES ON
MONDAY AFTERNOON...ALTHOUGH THERE ARE HINTS OF ANOTHER SHORTWAVE
DIVING INTO THE UPPER MISSISSIPPI VALLEY FOR MONDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 117 PM EST MON DEC 9 2013
KIWD...EXPECT MVFR CIGS AND -SN IN WSW FLOW THROUGH MUCH OF THIS AFTERNOON.
CONDITIONS SHOULD IMPROVE TO VFR THIS EVENING AS WINDS BACK MORE SW.
MVFR CONDITIONS IN LIGHT SNOW RETURN LATE TONIGHT WITH APPROACH OF
NEXT DISTURBANCE THE NOTRHERN PLAINS.
KCMX...IFR CONDITIONS WILL LOWER TO LIFR/VLIFR VSBY IN MODERATE TO
HEAVY LAKE EFFECT SNOW THIS AFTERNOON AS WSW WINDS VEER TO THE W AND
BECOME GUSTY. THIS WILL CONTINUE INTO THE EVENING HOURS BUT SHOULD
IMPROVE BY LATE EVENING. CONDITIONS WILL IMPROVE AGAIN TO MVFR LATE
TONIGHT AS THE HEAVIER LES BANDS SHIFT NORTH OF THE AREA.
KSAW...MVFR CIGS THIS AFTERNOON ARE EXPECTED THAT WILL LIFT BACK TO
VFR AS A DISTUBANCE MOVES TO THE EAST OF THE AREA. THE NEXT
SHORTWAVE TROUGH MOVING INTO THE AREA TUE MORNING WILL BRING ANOTHER
PERIOD OF MVFR CIGS WITH SOME LIGHT SNOW SHOWERS OR FLURRIES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 551 AM EST MON DEC 9 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES FOR GALES. THE FIRST TROUGH WILL
PASS ACROSS LAKE SUPERIOR LATE THIS MORNING/AFTERNOON VEERING WINDS
TO THE WEST AND INCREASING THEM TO GALES TO 35 TO 40 KNOTS ACROSS
LAKE SUPERIOR THIS AFTERNOON AND EVENING. AFTER A DECREASE TO 20 TO
30 KNOT SOUTHWEST WINDS TUESDAY MORNING...ANOTHER LOW PRESSURE WILL
TRACK EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND COULD PRODUCE
GALE FORCE WIND GUSTS TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON AND
EVENING. THE WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30 KNOTS
FROM LATE TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE EXTENDING FROM
HIGH PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS INTO THE AREA.
CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE POSSIBLE
THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR ACROSS THE
LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE SOUTHEASTWARD
ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WINDS SHOULD
REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR MIZ001-003.
LAKE EFFECT SNOW WATCH FROM TUESDAY EVENING THROUGH THURSDAY
MORNING FOR MIZ007.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 10 AM EST TUESDAY FOR LSZ245-
248>251-265>267.
GALE WARNING UNTIL 1 AM EST TUESDAY FOR LSZ244-245-248>251-
264>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ TUESDAY
FOR LSZ162-240>244-263-264.
GALE WARNING UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR
LSZ241>243-246-247.
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR LSZ263.
LAKE MICHIGAN...
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LMZ221-248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...SRF
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
118 PM EST MON DEC 9 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 551 AM EST MON DEC 9 2013
WV IMAGERY AND RUC ANALYSIS STILL SHOWING A BROAD MID/UPPER LEVEL
TROUGH OVER THE WRN CONUS RESULTING IN WSW FLOW FROM THE PLAINS INTO
THE GREAT LAKES. THERE ARE SEVERAL SHORTWAVES OF NOTE FOR THE SHORT
TERM.
ONE SHORTWAVE MOVING ACROSS LAKE MI INTO LOWER MI AND ITS
ASSOC SFC LOW PRODUCED LIGHT SNOW ACROSS THE CWA LAST NIGHT INTO THE
EARLY MORNING. MOST OF THE AREA RECEIVED GENERALLY NO MORE THAN AN
INCH OF SYSTEM SNOW...ALTHOUGH SOME LOCATIONS ALONG LAKE MI LIKELY
RECEIVED 2 TO LOCALLY 4 INCHES OF SNOW DUE TO LAKE ENHANCEMENT OF
SNOW OFF LAKE MI. MQT RADAR WAS SHOWING A MORE PROMINENT BAND OF
LAKE ENHANCED SNOW FROM NEAR COOKS/MANISTIQUE AREA NORTH TO
SHINGLETON IN THE PAST FEW HOURS ALTHOUGH IT LOOKS LIKE THIS BAND
MAY BE WEAKENING NOW AS BEST FORCING FOR ENHANCEMENT APPEARS TO BE
LIFTING EAST WITH THE SHORTWAVE. DUE TO ISOLATED NATURE OF THIS
BAND DECIDED TO ONLY KEEP WINTER WX ADVISORY GOING FOR ONLY
SCHOOLCRAFT COUNTY THRU 14Z AND DROPPED ADVISORY FOR MNM-DELTA AND
LUCE WHERE SNOW HAS BEEN VERY LIGHT AND APPEARS TO BE
DIMINISHING.
TODAY AND TONIGHT...THE MAIN SHORTWAVE OF CONCERN FOR THIS FCST PD
IS IMMEDIATELY UPSTREAM OVER THE NRN PLAINS AND WILL BE PUSHING
THROUGH THE UPPER GREAT LAKES LATE THIS MORNING AND AFTERNOON. THE
NEXT INTRUSION OF ARCTIC AIR WILL BE PUSHING INTO THE WESTERN CWA
BEHIND A COLD FRONT AT THE START OF THE PERIOD. MODELS INDICATE 850
MB TEMPS FALLING TO -20 TO -23C BY THE AFTERNOON COMBINED WITH
INVERSION HEIGHTS RISING TO 8-10KFT AND UNIDIRECTIONAL WESTERLY
WINDS RESULTING IN FAVORABLE LOW LEVEL CONV AND THE LIKELYHOOD OF A
DOMINANT LES BAND IMPACTING THE KEWEENAW PENINSULA. WITH THE PASSAGE
OF THE SHRTWV...EXPECT WINDS WOULD VEER FROM WSW TO MORE DUE
W...PUSHING THE DOMINANT BAND SLOWLY TO THE SOUTH FROM NEAR EAGLE
RIVER TO CALUMET/MOHAWK AND TO HOUGHTON THIS AFTERNOON AND TO POINTS
SOUTH OF HOUGHTON THIS EVENING. SNOWFALL ACCUMULATIONS WILL GREATLY
DEPEND ON HOW LONG THE HEAVIER BAND LINGERS IN ANY ONE
LOCATION...ACCUMULATIONS OF 6-10 INCHES REMAIN VERY LIKELY LATE THIS
MORNING THROUGH TONIGHT. IN ADDITION...BLUSTERY WEST WINDS OF
20-30MPH WITH GUSTS OVER 35 MPH WILL PRODUCE CONSIDERABLE BLOWING
AND DRIFTING SNOW AND NEAR WHITEOUT CONDITIONS WHERE THE DOMINANT
BAND SETS UP. HOWEVER...SINCE MOST OF THE 00Z AND 06Z LOCAL AND
REGIONAL HIGHER RES MODELS STILL INDICATE THAT THE DOMINANT BAND
WILL BE GRADUALLY MOVING SOUTH ACROSS THE KEWEENAW PENINSULA FROM
LATE MORNING THROUGH THE AFTERNOON HRS...FELT RELUCTANT TO UPGRADE
TO A WARNING AS AMOUNTS MAY BE SOMEWHAT LIMITED DUE TO TRANSIENT
NATURE OF BAND. I AM ALSO A LITTLE CONCERNED THAT BEST ENHANCEMENT
POTENTIAL FOR DOMINANT LES BAND WILL ARRIVE AHEAD OF THE SHORTWAVE
AND JUST BEFORE WINDS BEGIN TO VEER FROM WSW TO W SO THERE IS A
CHANCE THAT THE DOMINANT BAND MAY BE STRONGEST OUT OVER THE WATER
BEFORE IT REALLY MOVES ONSHORE TO THE KEWEENAW. DUE TO ABOVE
REASONING...DECIDED TO KEEP THE ADVISORY GOING BUT KEPT IN STRONGER
WORDING OF OCCASIONAL HEAVY SNOW AND CONSIDERABLE BLOWING
SNOW/LOCALIZED WHITEOUT CONDITONS IN WSW STATEMENT UNDER THE DOMINANT
BAND...STRESSING DIFFICULT TRAVEL AT TIMES DUE TO POOR VISIBILITY AND
BLOWING/DRIFTING SNOW. SOME OF THE HIGHER RES MODELS PARTICULARLY THE
LOCAL WRF-ARW INDICATE THAT DOMINANT COULD GET PUSHED SOUTH OF
HOUGHTON FOR A TIME THIS EVENING AND PERHAPS EVEN AFFECT NE ONTONAGON
AND NRN BARAGA COUNTIES BEFORE SHIFTING BACK ACROSS THE NRN PORTION
OF KEWEENAW OVERNIGHT AS WINDS BACK WSW AGAIN IN RESPONSE TO SFC RDG
BUILDING IN FM THE WEST.
THE REST OF THE CWA WILL FEEL THE EFFECT OF THE BITTER COLD AIR
FLOODING THE REGION. MAY FLIRT WITH WIND CHILL ADVISORY CRITERIA OF
25 BLO ZERO OR COLDER TONIGHT OVER THE WEST HALF INTERIOR OF THE CWA
AS ACTUAL TEMPS PLUMMET INTO THE DOUBLE DIGITS BLO ZERO.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 519 AM EST MON DEC 9 2013
CONTINUED NW FLOW ALOFT THROUGH THE WEEK WILL BRING LAKE EFFECT SNOW
FOR W TO NW FAVORED SNOW BELTS OFF AND ON. FOR THE REST OF UPPER
MI...ONLY BRIEF ROUNDS OF LIGHT SYNOPTIC SNOWFALL ARE EXPECTED.
ARCTIC AIR WILL REMAIN ANCHORED ACROSS THE REGION WITH MULTIPLE
REINFORCING SHOTS THROUGH THIS WEEKEND.
TUESDAY...DEEP TROUGHING OVER EASTERN NORTH AMERICA WILL CONTINUE TO
SEND MULTIPLE WEAK TROUGHS THROUGH THE GREAT LAKES REGION. THE FIRST
OF THESE IS PROGGED TO IMPACT THE CWA AT THE BEGINNING OF THE
FORECAST PERIOD. MODEL AGREEMENT HAS BEEN DECENT OVER THE PAST
COUPLE OF DAYS...SO OVERALL CONFIDENCE IS GOOD. THE WEAK SHORTWAVE
TROUGH WILL TRACK EASTWARD ACROSS NORTHERN WI THROUGHOUT THE DAY
TUESDAY. BESIDE MID-LEVEL Q-VECTOR CONV WITH THE TROUGH...THERE WILL
BE LITTLE SYNOPTIC SUPPORT. THOUGH A SECONDARY SFC LOW FORMING OVER
NORTHERN LAKE MI TUESDAY AFTERNOON IN RESPONSE THE TO MID-LEVEL
TROUGH/WARMER LAKE TEMPS COULD BACK SFC WINDS TO THE SW AND BRING
SOME MINOR LAKE ENHANCEMENT TO THE FAR SE CWA...MINIMAL ADDITIONAL
ACCUMULATION IS EXPECTED. OVERALL...CANNOT FIND ANYTHING TO JUSTIFY
THIS BEING MORE THAN A DUSTING OF SNOW FOR MOST AREAS.
EXPECTED WNW LES WILL BE SLOW TO GET GOING TUESDAY AFTERNOON UNTIL
THE MAIN SFC-H8 TROUGHS PASS EARLY TUESDAY EVENING. A BRIEF BOUT OF
SNOW ALONG THESE TROUGHS WILL BE POSSIBLE...SO BROUGHT HIGHER POPS
INLAND ACROSS THE NORTHERN CWA A BIT MORE THAN PREVIOUS FORECAST.
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT...BUMPED UP CLOUD COVER
TUESDAY NIGHT WITH LINGERING LOW-LEVEL MOISTURE AND NO REAL MEANS TO
GET RID OF IT. THIS IMPACTS LOW TEMPS...SO HAVE INCREASED THOSE A
DEGREE OR TWO. CLOUD COVER MAY CREATE SOME DISPARITY IN MIN TEMPS
ACROSS THE CWA...SO WOULD NOT BE SURPRISED IF ONLY PORTIONS OF THE
WEST HALF REACH THEIR FORECAST MIN TEMPS TO -10F.
LES PICKS UP IN INTENSITY WITH COLDER AIR CONTINUING TO ADVECT INTO
THE AREA. MODEL GUIDANCE IS PICKING UP ON CONSIDERABLE SFC
CONVERGENCE ALONG THE EASTERN SHORELINE AS THE DEPARTING SFC TROUGH
HOLDS ON OVER WARMER LAKE WATERS. COULD SEE AN IMPRESSIVE LES BAND
IN FAR NORTHERN LUCE TO NORTHERN CHIPPEWA COUNTIES. LOCATIONS VERY
NEAR LAKE SUPERIOR EAST OF GRAND MARAIS COULD SEE IN EXCESS OF 8
INCHES...WITH SOME LOCATIONS CLOSER TO WHITEFISH POINT POSSIBLY
SURPASSING A FOOT...TUESDAY NIGHT INTO WEDNESDAY MORNING. A LOT HAS
TO BE IRONED OUT WITH BAND PLACEMENT...SO DID NOT ISSUE AN LES WATCH
ATTM.
A WEAK AND BROAD TROUGH AXIS CROSSING THE AREA WEDNESDAY WILL ONLY
ENHANCE SOME LOW-LEVEL CLOUDINESS AND ASSIST IN KEEPING TEMPS EVEN
COLDER FOR THE DAY. WITH H8 TEMPS AT -25C AND CONTINUOUS CAA
THROUGHOUT THE DAY...INTERIOR WEST LOCATIONS...ESPECIALLY ALONG THE
WI BORDER...MAY FAIL TO GET ABOVE ZERO IN THE AFTERNOON. THE SFC
WIND FIELD BECOMES A BIT MUDDLED WEDNESDAY NIGHT AS A WEAK SFC LOW
TRACKS SE ACROSS IA...BUT A WEAK SFC RIDGE SHOULD KEEP WINDS LIGHT
AND ALLOW TEMPS TO PLUMMET ACROSS THE CWA. DID BUMP TEMPS BACK UP A
COUPLE DEGREES THOUGH AS MID-LEVEL CLOUDINESS MAY BE ON THE RISE
LATE IN THE NIGHT WITH THE APPROACH OF AN UPPER JET AND SUBTLE
MID-LEVEL TROUGH. WITH THAT SAID...SOME OF THE COLDEST LOCATIONS
ACROSS THE CENTRAL CWA COULD SEE TEMPS FALL AS LOW AS -20F. THOUGH
WINDS WILL BE LIGHT...WIND CHILLS WILL STILL DROP AS LOW AS -35F FOR
THE COLDEST LOCATIONS.
THURSDAY THROUGH SUNDAY...DID NOT FOCUS HEAVILY ON THIS PERIOD GIVEN
SOME MODEL DISAGREEMENT. USED THE ECMWF HEAVILY AS THE GFS HAS
DEVELOPED SOME CONTINUITY ISSUES OVER THE PAST FEW RUNS. OVERALL
PATTERN BEGINS TO CHANGE SOMEWHAT...THOUGH TEMPS WILL REMAIN WELL
BELOW NORMAL. A WEAK CLIPPER SYSTEM LOOKS TO BRING ANOTHER ROUND OF
VERY LIGHT SNOW THURSDAY...BUT ONCE AGAIN...OVERALL SUPPORT IS
MINIMAL. AN ASSOCIATED SFC TROUGH WILL LAY OUT ACROSS THE UPPER MS
VALLEY THROUGH FRIDAY. COMBINED WITH THE RIGHT ENTRANCE OF THE
PASSING UPPER JET...SOME MINOR SYNOPTIC SNOW IS POSSIBLE
FRIDAY...BUT DID NOT PLACE MORE THAN SLIGHT CHANCE POPS AWAY FROM
LAKE SUPERIOR. PLENTY OF CLOUD COVERED AND CONTINUED LES FOR NW SNOW
BELTS SHOULD LAST INTO SATURDAY...BUT MUCH LOWER INVERSION HEIGHTS
WILL LIKELY PREVENT ANY SIGNIFICANT ACCUMULATIONS. WHAT WAS STARTING
TO LOOK LIKE A WARMING TREND THROUGH THE WEEKEND MAY BE HALTED BY
YET ANOTHER CLIPPER SYSTEM TRACKING SE ACROSS THE AREA ON SUNDAY.
COLDER AIR WILL WRAP AROUND THIS AND KEEP TEMPS DOWN INTO EARLY NEXT
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 117 PM EST MON DEC 9 2013
KIWD...EXPECT MVFR CIGS AND -SN IN WSW FLOW THROUGH MUCH OF THIS AFTERNOON.
CONDITIONS SHOULD IMPROVE TO VFR THIS EVENING AS WINDS BACK MORE SW.
MVFR CONDITIONS IN LIGHT SNOW RETURN LATE TONIGHT WITH APPROACH OF
NEXT DISTURBANCE THE NOTRHERN PLAINS.
KCMX...IFR CONDITIONS WILL LOWER TO LIFR/VLIFR VSBY IN MODERATE TO
HEAVY LAKE EFFECT SNOW THIS AFTERNOON AS WSW WINDS VEER TO THE W AND
BECOME GUSTY. THIS WILL CONTINUE INTO THE EVENING HOURS BUT SHOULD
IMPROVE BY LATE EVENING. CONDITIONS WILL IMPROVE AGAIN TO MVFR LATE
TONIGHT AS THE HEAVIER LES BANDS SHIFT NORTH OF THE AREA.
KSAW...MVFR CIGS THIS AFTERNOON ARE EXPECTED THAT WILL LIFT BACK TO
VFR AS A DISTUBANCE MOVES TO THE EAST OF THE AREA. THE NEXT
SHORTWAVE TROUGH MOVING INTO THE AREA TUE MORNING WILL BRING ANOTHER
PERIOD OF MVFR CIGS WITH SOME LIGHT SNOW SHOWERS OR FLURRIES.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 551 AM EST MON DEC 9 2013(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 400 PM EST SUN DEC 8 2013
A SERIES OF TROUGHS WILL CROSS LAKE SUPERIOR THROUGH THE UPCOMING
WEEK AND BRING MULTIPLE CHANCES FOR GALES. THE FIRST TROUGH WILL
PASS ACROSS LAKE SUPERIOR LATE THIS MORNING/AFTERNOON VEERING WINDS
TO THE WEST AND INCREASING THEM TO GALES TO 35 TO 40 KNOTS ACROSS
LAKE SUPERIOR THIS AFTERNOON AND EVENING. AFTER A DECREASE TO 20 TO
30 KNOT SOUTHWEST WINDS TUESDAY MORNING...ANOTHER LOW PRESSURE WILL
TRACK EASTWARD ACROSS LAKE SUPERIOR ON TUESDAY AND COULD PRODUCE
GALE FORCE WIND GUSTS TO 35 KNOTS BEHIND IT TUESDAY AFTERNOON AND
EVENING. THE WESTERLY WINDS WILL WEAKEN SLIGHTLY TO 20 TO 30 KNOTS
FROM LATE TUESDAY NIGHT INTO THURSDAY AS A WEAK RIDGE EXTENDING FROM
HIGH PRESSURE IN THE CENTRAL PLAINS SLOWLY BUILDS INTO THE AREA.
CONTINUED MODERATE TO HEAVY FREEZING SPRAY WILL BE POSSIBLE
THROUGHOUT THE PERIOD WITH SEVERAL PUSHES OF ARCTIC AIR ACROSS THE
LAKE. ANOTHER WEAK LOW PRESSURE SYSTEM WILL MOVE SOUTHEASTWARD
ACROSS LAKE SUPERIOR THURSDAY NIGHT INTO FRIDAY...BUT WINDS SHOULD
REMAIN UNDER 20 KNOTS THROUGH SATURDAY BEHIND THIS SYSTEM.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST TUESDAY FOR MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
TUESDAY FOR LSZ245-248>251-265>267.
GALE WARNING UNTIL 5 AM EST TUESDAY FOR LSZ244-245-265>267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ TUESDAY
FOR LSZ162-240>244-263-264.
GALE WARNING UNTIL 5 AM EST TUESDAY FOR LSZ264.
GALE WARNING UNTIL 10 PM EST /9 PM CST/ THIS EVENING FOR
LSZ241>243-246-247.
GALE WARNING UNTIL MIDNIGHT EST TONIGHT FOR LSZ263.
LAKE MICHIGAN...
GALE WARNING UNTIL 10 PM EST THIS EVENING FOR LMZ221-248-250.
&&
$$
SHORT TERM...VOSS
LONG TERM...KLUBER
AVIATION...JLB
MARINE...VOSS
AREA FORECAST DISCUSSION...UPDATED
NWS BILLINGS MT
1244 PM MST MON DEC 9 2013
.UPDATE...
MAKING ANOTHER QUICK UPDATE THIS MORNING TO ACCOUNT FOR THE
EXPIRATION OF THE WIND CHILL ADVISORY THAT IS REPLACED WITH A
WINTER WEATHER ADVISORY. OTHERWISE...THE GOING FORECAST APPEARS
TO BE IN GOOD SHAPE. AAG
&&
.SHORT TERM...VALID FOR TDY AND TUE...
WIND-RELATED WINTER WEATHER ISSUES TODAY WILL TRANSITION BACK TO A
HIGH PROBABILITY OF 1 TO 2 INCHES OF SNOW IN MANY AREAS TUE AS TWO
SHORT WAVES CROSS THE REGION IN STRONG NORTHWEST FLOW ALOFT. WE DO
STILL EXPECT A SLOW MODERATION IN TEMPERATURES TO CONTINUE THOUGH.
TODAY...LEE-SIDE SURFACE PRESSURE FALLS ON THE ORDER OF 5 HPA/3 HR
CENTERED ACROSS THE CENTRAL ALBERTA-SASKATCHEWAN BORDER EARLY THIS
MORNING WILL REACH NORTHEAST MT AND WESTERN ND BY MIDDAY. THE WIND
SPEEDS IN SOUTH CENTRAL MT WILL CONTINUE RAMPING UP AS THAT OCCURS
AND WILL BE BOOSTED FURTHER BY EXTRA PRESSURE GRADIENT THANKS TO A
FORMIDABLE COLD AIR MASS TRAPPED WEST OF THE LOCAL MOUNTAINS. WIND
SPEEDS IN THE GRIDDED FORECAST WERE HEAVILY WEIGHTED TO RAP OUTPUT
SINCE IT IS HANDLING EARLY-DAY WINDS NEAR BIG TIMBER /WHICH IS THE
FAVORED SPOT FOR THE HIGHEST SPEEDS IN THIS PATTERN/ WELL. WE THUS
HAVE HIGH CONFIDENCE IN SUSTAINED SPEEDS OF 40 TO 50 MPH AND GUSTS
TO 70 MPH FROM LIVINGSTON TO BIG TIMBER TODAY...AND GUSTS UP TO 55
MPH AT HARLOWTON AND 45 MPH AROUND BILLINGS TOO. THE WINDS WILL BE
ON THE INCREASE ON THE PLAINS OF SOUTH CENTRAL AND SOUTHEAST MT BY
21 UTC AS WELL AS MIXING INCREASES AND A MODEST BATCH OF LOW-LEVEL
HEIGHT RISES BEGINS AFFECTING THAT AREA...THOUGH MOMENTUM TRANSFER
WILL BE LACKING AND ONLY SUPPORTS GUSTS TO ABOUT 35 MPH ACROSS THE
SOUTHEAST PART OF MT. ADD IN SNOW SHOWERS WHICH COULD DROP A QUICK
INCH OF SNOW AND REDUCE VISIBILITY ON THEIR OWN TOO OVER SOUTHEAST
MT THOUGH...AND CONDITIONS COULD BE QUITE HAZARDOUS OVER THAT AREA
AS WELL. WE ACTUALLY PUSHED POPS FOR SNOW SHOWER ACTIVITY INTO THE
70-90 PERCENT RANGE OVER SOUTHEAST MT THIS AFTERNOON BASED ON GOOD
AGREEMENT IN 00 UTC GUIDANCE IN NOTABLE QG-FORCING OVER THAT AREA.
NEEDLESS TO SAY...BLOWING AND DRIFTING SNOW IS MENTIONED TODAY AND
INTO THIS EVENING FOR MOST OF THE AREA...THOUGH DEPTH AND PHYSICAL
CHARACTERISTICS OF THE SNOW SUGGEST THE BIGGEST ISSUE COULD END UP
BEING SIGNIFICANT DRIFTING. WE WILL NONETHELESS NEED TO BE WARY OF
THE POSSIBILITY OF BONAFIDE GROUND BLIZZARD CONDITIONS IN THE OPEN
COUNTRY WHERE LOCALLY DEEPER SNOW PACK RESIDES...THOUGH THE CHANCE
OF THAT APPEARS RELATIVELY LOW /SUBJECTIVELY NEAR 30 PERCENT/.
WHERE HEADLINES ARE CONCERNED...WE ADDED ALL OF BIG HORN COUNTY TO
A WINTER WEATHER ADVISORY FROM 18 TO 06 UTC SINCE OUR RAP-WEIGHTED
WIND FORECAST SUPPORTED SPEEDS SUFFICIENT FOR BLOWING AND DRIFTING
SNOW ISSUES THERE TOO. THE REST OF OUR PREVIOUSLY-ISSUED HEADLINES
WERE LEFT IN TACT. WE WILL PROBABLY HIT HIGH WIND CRITERIA FOR THE
SUSTAINED 50 MPH SPEEDS AT BIG TIMBER TODAY...BUT FELT IT WAS BEST
TO COVER THIS WITH ONE PRODUCT...THE WINTER WEATHER ADVISORY. NOTE
THAT IF WINDS IN SOUTH CENTRAL MT /NAMELY IN THE LIVINGSTON TO BIG
TIMBER CORRIDOR/ STAY UP PAST 12 UTC TUE MORNING AS SOME OF THE 00
UTC GUIDANCE SHOWS...PARTS OF THE ADVISORY MAY NEED TO BE EXTENDED
IN TIME WITH A LATER FORECAST RELEASE.
TONIGHT...THE SHORT WAVE WILL EXIT THE AREA...AND WINDS WILL BE ON
A DOWNWARD TREND /ESPECIALLY AFTER 06 UTC/...EVEN THOUGH THEY WILL
STAY GUSTY IN SOUTH CENTRAL MT. WE CAUTIOUSLY FOLLOWED THE LEAD OF
RECENTLY WELL-PERFORMING GUIDANCE THAT SHOWS LOWS ONLY AROUND 10 F
/MUCH WARMER THAN RECENT NIGHTS/ GIVEN EXPECTED LOW-LEVEL MIXING.
TUE...A LIGHT SNOW EVENT IS EXPECTED IN MANY AREAS AS A GOOD BATCH
OF QG-FORCING WITH ANOTHER SHORT WAVE TROUGH RIDES SOUTHEAST ALONG
THE THERMAL BOUNDARY LEFT BEHIND TODAY/S WAVE. IT LOOKS LIKE WINDS
WILL EVEN TURN NORTH OR NORTHEAST IN BILLINGS BY AFTERNOON...SO WE
WILL PROBABLY GET IN ON SOME LIGHT SNOW HERE TOO. WE HAD ENOUGH IN
THE WAY OF CONFIDENCE IN THIS WHOLE SCENARIO TO SIGNIFICANTLY RAMP
UP POPS IN MANY AREAS...GOING AS FAR AS 80 PERCENT FROM MILES CITY
TO HYSHAM AND DOWN TOWARD LAME DEER AND LODGE GRASS. THIS LOOKS TO
BE A GOOD 1 TO 2 INCH SNOW EVENT IN MANY AREAS. SCHULTZ
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
NORTHWEST FLOW ALOFT ON WEDNESDAY SLOWLY BECOMES A MORE WESTERLY
FLOW ON THURSDAY WHICH WILL ALLOW A LEESIDE SURFACE PRESSURE
TROUGH TO BE THE DOMINANT FEATURE EAST OF THE CONTINENTAL DIVIDE.
THIS PATTERN HOLDS UNTIL LATER ON FRIDAY WHEN AN UPPER LEVEL RIDGE
BUILDING INTO THE PACIFIC NORTHWEST TURNS THE FLOW NORTHWESTERLY
OVER MONTANA AND WYOMING. AT SOME POINT COLDER AIR OVER THE
DAKOTAS WILL HAVE A CHANCE TO PUSH A BACKDOOR COLD FRONT INTO
SOUTHERN MONTANA BUT WHEN IS NOT EXACTLY SURE...WHETHER IT WILL BE
FRIDAY NIGHT OR SATURDAY NIGHT. THIS IS THE BEST CHANCE FOR SNOW
IN THE PLAINS DURING THE EXTENDED PERIOD...THOUGH THE MODELS WILL
HAVE CHANCES FOR OROGRAPHIC SHOWERS AS THE FLOW ALOFT CONTINUES TO
BE FAIRLY MOIST.
TEMPERATURES WEDNESDAY THROUGH FRIDAY ARE GOING TO BE GOVERNED BY
A COUPLE OF FACTORS. DOWNSLOPE WINDS WILL BE FAVORED ACROSS THE
WESTERN AND CENTRAL ZONES BUT AIR WEST OF THE DIVIDE IS SO COLD
THAT THE WARMUP WILL BE MUCH SLOWER THAN NORMAL FOEHN WINDS WOULD
CREATE. ALSO...SNOW COVER WILL REGULATE A PART OF THE WARMUP AND
THE POSITION OF THE SURFACE TROUGH WILL SHOW THE EASTWARD EXTENT
OF THE BEST WARMING WITH TEMPERATURES STAYING COOLER EAST OF THE
TROUGH. BY THE WEEKEND THE PUSH WESTWARD OF THE COLD FRONT WILL
SUPPORT A DROP OF TEMPERATURES BUT AGAIN HOW FAR WEST AND HOW
DRAMATIC IS STILL NOT CERTAIN. WITH COLDER AIR POOLED UP WEST OF
THE DIVIDE WIND IS GOING TO BE A OMNIPRESENT FEATURE FOR THE
WESTERN ZONES. BORSUM
&&
.AVIATION...
QUICK UPDATE FOR AVIATION CONDITIONS THIS AFTERNOON...A BAND OF
FAIRLY HEAVY SNOWFALL HAS CAUSED VISIBILITIES TO DETERIORATE RAPIDLY
AT KMLS AND KBHK. THIS COMBINED WITH VERY GUSTY WINDS AND PREVIOUS
SNOWFALL ON THE GROUND...WILL BRING WITH IT IFR CONDITIONS. THE
SNOW SHOWERS SHOULD END IN THE NEXT FEW HOURS... BUT THE GUSTY
WINDS WILL PERSIST INTO THE EVENING. SINGER
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 019 014/023 005/029 020/033 018/034 015/034 024/036
1/Q 16/S 51/B 11/B 11/B 11/B 11/B
LVM 016 010/022 007/026 020/032 021/034 019/032 024/033
2/J 24/S 42/J 11/N 12/J 11/B 11/N
HDN 022 012/022 901/027 014/035 015/032 012/032 022/036
2/J 28/S 51/B 11/B 11/E 11/B 12/B
MLS 020 009/016 907/023 010/031 013/026 010/028 020/035
9/J 38/S 21/B 11/B 12/J 11/B 22/B
4BQ 020 011/020 903/022 011/034 017/031 012/032 023/036
8/J 47/S 21/B 00/B 01/B 11/B 22/B
BHK 016 009/013 910/017 009/029 012/022 010/027 018/033
9/J 56/S 11/B 01/B 11/B 11/E 12/B
SHR 023 008/024 901/027 014/036 016/034 014/033 022/038
2/J 25/S 51/B 01/B 12/J 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 AM MST TUESDAY FOR
ZONES 28-29-34-35-39-41-42-56-63-65-66.
WINTER WEATHER ADVISORY IN EFFECT UNTIL 11 PM MST THIS
EVENING FOR ZONES 30>33-36>38-57-58.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1127 AM MST MON DEC 9 2013
.UPDATE...
MAKING ANOTHER QUICK UPDATE THIS MORNING TO ACCOUNT FOR THE
EXPIRATION OF THE WIND CHILL ADVISORY THAT IS REPLACED WITH A
WINTER WEATHER ADVISORY. OTHERWISE...THE GOING FORECAST APPEARS
TO BE IN GOOD SHAPE. AAG
&&
.SHORT TERM...VALID FOR TDY AND TUE...
WIND-RELATED WINTER WEATHER ISSUES TODAY WILL TRANSITION BACK TO A
HIGH PROBABILITY OF 1 TO 2 INCHES OF SNOW IN MANY AREAS TUE AS TWO
SHORT WAVES CROSS THE REGION IN STRONG NORTHWEST FLOW ALOFT. WE DO
STILL EXPECT A SLOW MODERATION IN TEMPERATURES TO CONTINUE THOUGH.
TODAY...LEE-SIDE SURFACE PRESSURE FALLS ON THE ORDER OF 5 HPA/3 HR
CENTERED ACROSS THE CENTRAL ALBERTA-SASKATCHEWAN BORDER EARLY THIS
MORNING WILL REACH NORTHEAST MT AND WESTERN ND BY MIDDAY. THE WIND
SPEEDS IN SOUTH CENTRAL MT WILL CONTINUE RAMPING UP AS THAT OCCURS
AND WILL BE BOOSTED FURTHER BY EXTRA PRESSURE GRADIENT THANKS TO A
FORMIDABLE COLD AIR MASS TRAPPED WEST OF THE LOCAL MOUNTAINS. WIND
SPEEDS IN THE GRIDDED FORECAST WERE HEAVILY WEIGHTED TO RAP OUTPUT
SINCE IT IS HANDLING EARLY-DAY WINDS NEAR BIG TIMBER /WHICH IS THE
FAVORED SPOT FOR THE HIGHEST SPEEDS IN THIS PATTERN/ WELL. WE THUS
HAVE HIGH CONFIDENCE IN SUSTAINED SPEEDS OF 40 TO 50 MPH AND GUSTS
TO 70 MPH FROM LIVINGSTON TO BIG TIMBER TODAY...AND GUSTS UP TO 55
MPH AT HARLOWTON AND 45 MPH AROUND BILLINGS TOO. THE WINDS WILL BE
ON THE INCREASE ON THE PLAINS OF SOUTH CENTRAL AND SOUTHEAST MT BY
21 UTC AS WELL AS MIXING INCREASES AND A MODEST BATCH OF LOW-LEVEL
HEIGHT RISES BEGINS AFFECTING THAT AREA...THOUGH MOMENTUM TRANSFER
WILL BE LACKING AND ONLY SUPPORTS GUSTS TO ABOUT 35 MPH ACROSS THE
SOUTHEAST PART OF MT. ADD IN SNOW SHOWERS WHICH COULD DROP A QUICK
INCH OF SNOW AND REDUCE VISIBILITY ON THEIR OWN TOO OVER SOUTHEAST
MT THOUGH...AND CONDITIONS COULD BE QUITE HAZARDOUS OVER THAT AREA
AS WELL. WE ACTUALLY PUSHED POPS FOR SNOW SHOWER ACTIVITY INTO THE
70-90 PERCENT RANGE OVER SOUTHEAST MT THIS AFTERNOON BASED ON GOOD
AGREEMENT IN 00 UTC GUIDANCE IN NOTABLE QG-FORCING OVER THAT AREA.
NEEDLESS TO SAY...BLOWING AND DRIFTING SNOW IS MENTIONED TODAY AND
INTO THIS EVENING FOR MOST OF THE AREA...THOUGH DEPTH AND PHYSICAL
CHARACTERISTICS OF THE SNOW SUGGEST THE BIGGEST ISSUE COULD END UP
BEING SIGNIFICANT DRIFTING. WE WILL NONETHELESS NEED TO BE WARY OF
THE POSSIBILITY OF BONAFIDE GROUND BLIZZARD CONDITIONS IN THE OPEN
COUNTRY WHERE LOCALLY DEEPER SNOW PACK RESIDES...THOUGH THE CHANCE
OF THAT APPEARS RELATIVELY LOW /SUBJECTIVELY NEAR 30 PERCENT/.
WHERE HEADLINES ARE CONCERNED...WE ADDED ALL OF BIG HORN COUNTY TO
A WINTER WEATHER ADVISORY FROM 18 TO 06 UTC SINCE OUR RAP-WEIGHTED
WIND FORECAST SUPPORTED SPEEDS SUFFICIENT FOR BLOWING AND DRIFTING
SNOW ISSUES THERE TOO. THE REST OF OUR PREVIOUSLY-ISSUED HEADLINES
WERE LEFT IN TACT. WE WILL PROBABLY HIT HIGH WIND CRITERIA FOR THE
SUSTAINED 50 MPH SPEEDS AT BIG TIMBER TODAY...BUT FELT IT WAS BEST
TO COVER THIS WITH ONE PRODUCT...THE WINTER WEATHER ADVISORY. NOTE
THAT IF WINDS IN SOUTH CENTRAL MT /NAMELY IN THE LIVINGSTON TO BIG
TIMBER CORRIDOR/ STAY UP PAST 12 UTC TUE MORNING AS SOME OF THE 00
UTC GUIDANCE SHOWS...PARTS OF THE ADVISORY MAY NEED TO BE EXTENDED
IN TIME WITH A LATER FORECAST RELEASE.
TONIGHT...THE SHORT WAVE WILL EXIT THE AREA...AND WINDS WILL BE ON
A DOWNWARD TREND /ESPECIALLY AFTER 06 UTC/...EVEN THOUGH THEY WILL
STAY GUSTY IN SOUTH CENTRAL MT. WE CAUTIOUSLY FOLLOWED THE LEAD OF
RECENTLY WELL-PERFORMING GUIDANCE THAT SHOWS LOWS ONLY AROUND 10 F
/MUCH WARMER THAN RECENT NIGHTS/ GIVEN EXPECTED LOW-LEVEL MIXING.
TUE...A LIGHT SNOW EVENT IS EXPECTED IN MANY AREAS AS A GOOD BATCH
OF QG-FORCING WITH ANOTHER SHORT WAVE TROUGH RIDES SOUTHEAST ALONG
THE THERMAL BOUNDARY LEFT BEHIND TODAY/S WAVE. IT LOOKS LIKE WINDS
WILL EVEN TURN NORTH OR NORTHEAST IN BILLINGS BY AFTERNOON...SO WE
WILL PROBABLY GET IN ON SOME LIGHT SNOW HERE TOO. WE HAD ENOUGH IN
THE WAY OF CONFIDENCE IN THIS WHOLE SCENARIO TO SIGNIFICANTLY RAMP
UP POPS IN MANY AREAS...GOING AS FAR AS 80 PERCENT FROM MILES CITY
TO HYSHAM AND DOWN TOWARD LAME DEER AND LODGE GRASS. THIS LOOKS TO
BE A GOOD 1 TO 2 INCH SNOW EVENT IN MANY AREAS. SCHULTZ
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
NORTHWEST FLOW ALOFT ON WEDNESDAY SLOWLY BECOMES A MORE WESTERLY
FLOW ON THURSDAY WHICH WILL ALLOW A LEESIDE SURFACE PRESSURE
TROUGH TO BE THE DOMINANT FEATURE EAST OF THE CONTINENTAL DIVIDE.
THIS PATTERN HOLDS UNTIL LATER ON FRIDAY WHEN AN UPPER LEVEL RIDGE
BUILDING INTO THE PACIFIC NORTHWEST TURNS THE FLOW NORTHWESTERLY
OVER MONTANA AND WYOMING. AT SOME POINT COLDER AIR OVER THE
DAKOTAS WILL HAVE A CHANCE TO PUSH A BACKDOOR COLD FRONT INTO
SOUTHERN MONTANA BUT WHEN IS NOT EXACTLY SURE...WHETHER IT WILL BE
FRIDAY NIGHT OR SATURDAY NIGHT. THIS IS THE BEST CHANCE FOR SNOW
IN THE PLAINS DURING THE EXTENDED PERIOD...THOUGH THE MODELS WILL
HAVE CHANCES FOR OROGRAPHIC SHOWERS AS THE FLOW ALOFT CONTINUES TO
BE FAIRLY MOIST.
TEMPERATURES WEDNESDAY THROUGH FRIDAY ARE GOING TO BE GOVERNED BY
A COUPLE OF FACTORS. DOWNSLOPE WINDS WILL BE FAVORED ACROSS THE
WESTERN AND CENTRAL ZONES BUT AIR WEST OF THE DIVIDE IS SO COLD
THAT THE WARMUP WILL BE MUCH SLOWER THAN NORMAL FOEHN WINDS WOULD
CREATE. ALSO...SNOW COVER WILL REGULATE A PART OF THE WARMUP AND
THE POSITION OF THE SURFACE TROUGH WILL SHOW THE EASTWARD EXTENT
OF THE BEST WARMING WITH TEMPERATURES STAYING COOLER EAST OF THE
TROUGH. BY THE WEEKEND THE PUSH WESTWARD OF THE COLD FRONT WILL
SUPPORT A DROP OF TEMPERATURES BUT AGAIN HOW FAR WEST AND HOW
DRAMATIC IS STILL NOT CERTAIN. WITH COLDER AIR POOLED UP WEST OF
THE DIVIDE WIND IS GOING TO BE A OMNIPRESENT FEATURE FOR THE
WESTERN ZONES. BORSUM
&&
.AVIATION...
FAST MOVING COLD FRONT WILL MOVE THROUGH EASTERN AND CENTRAL
MONTANA BRINGING INCREASED WINDS...BLOWING SNOW AND SNOW SHOWERS.
BEST CHANCE FOR SNOW WILL BE FOR EASTERN MONTANA WITH BLOWING SNOW
BEING THE BIGGEST PROBLEM FOR KBIL AND KLVM. VERY STRONG WINDS ARE
POSSIBLE FOR KLVM WITH DRIFTING AND BLOWING SNOW CREATING IFR
CONDITIONS AT TIMES. KBIL WILL SEE WINDS GUSTS TO 45 MPH WITH MVFR
CONDITIONS DUE TO BLOWING SNOW. KMLS WILL SEE LOWER CEILINGS IN
THE SNOW SHOWERS WITH IFR CONDITIONS AT TIMES. KSHR WILL SEE
CONDITIONS STAY MOSTLY VFR BUT WILL APPROACH MVFR CONDITIONS LATER
IN THE AFTERNOON. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 019 014/023 005/029 020/033 018/034 015/034 024/036
1/Q 16/S 51/B 11/B 11/B 11/B 11/B
LVM 016 010/022 007/026 020/032 021/034 019/032 024/033
2/J 24/S 42/J 11/N 12/J 11/B 11/N
HDN 022 012/022 901/027 014/035 015/032 012/032 022/036
2/J 28/S 51/B 11/B 11/E 11/B 12/B
MLS 020 009/016 907/023 010/031 013/026 010/028 020/035
9/J 38/S 21/B 11/B 12/J 11/B 22/B
4BQ 020 011/020 903/022 011/034 017/031 012/032 023/036
8/J 47/S 21/B 00/B 01/B 11/B 22/B
BHK 016 009/013 910/017 009/029 012/022 010/027 018/033
9/J 56/S 11/B 01/B 11/B 11/E 12/B
SHR 023 008/024 901/027 014/036 016/034 014/033 022/038
2/J 25/S 51/B 01/B 12/J 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 AM MST TUESDAY FOR
ZONES 28-29-34-35-39-41-42-56-63-65-66.
WINTER WEATHER ADVISORY IN EFFECT UNTIL 11 PM MST THIS
EVENING FOR ZONES 30>33-36>38-57-58.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
916 AM MST MON DEC 9 2013
.UPDATE...
NO CHANGES MADE TO INHERITED FORECAST. THE SHORT TERM FORECAST
APPEARS IN GOOD SHAPE...WITH STRONG AND GUSTY WINDS IMPACTING
AREAS FROM BILLINGS TO THE WEST. STRONGEST WINDS ARE IN BIG TIMBER
AND LIVINGSTON...WHERE GUSTS ARE APPROACHING 60 MPH AND ARE
EXPECTED TO INCREASE INTO THIS AFTERNOON. VISIBILITIES HAVE BEEN
REDUCED TO LESS THAN A QUARTER MILE IN BIG TIMBER AND TO AROUND 1
MILE IN LIVINGSTON...WITH LOCALIZED WHITE OUT CONDITIONS. THESE
LOCALIZED WHITE OUT CONDITIONS ARE EXPECTED TO CONTINUE THROUGH
TODAY...AND POSSIBLY INTO TONIGHT.
ADDITIONALLY...SLIDE OFFS HAVE BEEN REPORTED IN SEVERAL LOCATIONS
INCLUDING MUSSELSHELL...STILLWATER...AND SWEET GRASS COUNTIES.
BLOWING AND DRIFTING SNOW MAY HAVE BEEN A CONTRIBUTING FACTOR IN
CONJUNCTION WITH ALREADY ICY ROADWAYS. AAG
&&
.SHORT TERM...VALID FOR TDY AND TUE...
WIND-RELATED WINTER WEATHER ISSUES TODAY WILL TRANSITION BACK TO A
HIGH PROBABILITY OF 1 TO 2 INCHES OF SNOW IN MANY AREAS TUE AS TWO
SHORT WAVES CROSS THE REGION IN STRONG NORTHWEST FLOW ALOFT. WE DO
STILL EXPECT A SLOW MODERATION IN TEMPERATURES TO CONTINUE THOUGH.
TODAY...LEE-SIDE SURFACE PRESSURE FALLS ON THE ORDER OF 5 HPA/3 HR
CENTERED ACROSS THE CENTRAL ALBERTA-SASKATCHEWAN BORDER EARLY THIS
MORNING WILL REACH NORTHEAST MT AND WESTERN ND BY MIDDAY. THE WIND
SPEEDS IN SOUTH CENTRAL MT WILL CONTINUE RAMPING UP AS THAT OCCURS
AND WILL BE BOOSTED FURTHER BY EXTRA PRESSURE GRADIENT THANKS TO A
FORMIDABLE COLD AIR MASS TRAPPED WEST OF THE LOCAL MOUNTAINS. WIND
SPEEDS IN THE GRIDDED FORECAST WERE HEAVILY WEIGHTED TO RAP OUTPUT
SINCE IT IS HANDLING EARLY-DAY WINDS NEAR BIG TIMBER /WHICH IS THE
FAVORED SPOT FOR THE HIGHEST SPEEDS IN THIS PATTERN/ WELL. WE THUS
HAVE HIGH CONFIDENCE IN SUSTAINED SPEEDS OF 40 TO 50 MPH AND GUSTS
TO 70 MPH FROM LIVINGSTON TO BIG TIMBER TODAY...AND GUSTS UP TO 55
MPH AT HARLOWTON AND 45 MPH AROUND BILLINGS TOO. THE WINDS WILL BE
ON THE INCREASE ON THE PLAINS OF SOUTH CENTRAL AND SOUTHEAST MT BY
21 UTC AS WELL AS MIXING INCREASES AND A MODEST BATCH OF LOW-LEVEL
HEIGHT RISES BEGINS AFFECTING THAT AREA...THOUGH MOMENTUM TRANSFER
WILL BE LACKING AND ONLY SUPPORTS GUSTS TO ABOUT 35 MPH ACROSS THE
SOUTHEAST PART OF MT. ADD IN SNOW SHOWERS WHICH COULD DROP A QUICK
INCH OF SNOW AND REDUCE VISIBILITY ON THEIR OWN TOO OVER SOUTHEAST
MT THOUGH...AND CONDITIONS COULD BE QUITE HAZARDOUS OVER THAT AREA
AS WELL. WE ACTUALLY PUSHED POPS FOR SNOW SHOWER ACTIVITY INTO THE
70-90 PERCENT RANGE OVER SOUTHEAST MT THIS AFTERNOON BASED ON GOOD
AGREEMENT IN 00 UTC GUIDANCE IN NOTABLE QG-FORCING OVER THAT AREA.
NEEDLESS TO SAY...BLOWING AND DRIFTING SNOW IS MENTIONED TODAY AND
INTO THIS EVENING FOR MOST OF THE AREA...THOUGH DEPTH AND PHYSICAL
CHARACTERISTICS OF THE SNOW SUGGEST THE BIGGEST ISSUE COULD END UP
BEING SIGNIFICANT DRIFTING. WE WILL NONETHELESS NEED TO BE WARY OF
THE POSSIBILITY OF BONAFIDE GROUND BLIZZARD CONDITIONS IN THE OPEN
COUNTRY WHERE LOCALLY DEEPER SNOW PACK RESIDES...THOUGH THE CHANCE
OF THAT APPEARS RELATIVELY LOW /SUBJECTIVELY NEAR 30 PERCENT/.
WHERE HEADLINES ARE CONCERNED...WE ADDED ALL OF BIG HORN COUNTY TO
A WINTER WEATHER ADVISORY FROM 18 TO 06 UTC SINCE OUR RAP-WEIGHTED
WIND FORECAST SUPPORTED SPEEDS SUFFICIENT FOR BLOWING AND DRIFTING
SNOW ISSUES THERE TOO. THE REST OF OUR PREVIOUSLY-ISSUED HEADLINES
WERE LEFT IN TACT. WE WILL PROBABLY HIT HIGH WIND CRITERIA FOR THE
SUSTAINED 50 MPH SPEEDS AT BIG TIMBER TODAY...BUT FELT IT WAS BEST
TO COVER THIS WITH ONE PRODUCT...THE WINTER WEATHER ADVISORY. NOTE
THAT IF WINDS IN SOUTH CENTRAL MT /NAMELY IN THE LIVINGSTON TO BIG
TIMBER CORRIDOR/ STAY UP PAST 12 UTC TUE MORNING AS SOME OF THE 00
UTC GUIDANCE SHOWS...PARTS OF THE ADVISORY MAY NEED TO BE EXTENDED
IN TIME WITH A LATER FORECAST RELEASE.
TONIGHT...THE SHORT WAVE WILL EXIT THE AREA...AND WINDS WILL BE ON
A DOWNWARD TREND /ESPECIALLY AFTER 06 UTC/...EVEN THOUGH THEY WILL
STAY GUSTY IN SOUTH CENTRAL MT. WE CAUTIOUSLY FOLLOWED THE LEAD OF
RECENTLY WELL-PERFORMING GUIDANCE THAT SHOWS LOWS ONLY AROUND 10 F
/MUCH WARMER THAN RECENT NIGHTS/ GIVEN EXPECTED LOW-LEVEL MIXING.
TUE...A LIGHT SNOW EVENT IS EXPECTED IN MANY AREAS AS A GOOD BATCH
OF QG-FORCING WITH ANOTHER SHORT WAVE TROUGH RIDES SOUTHEAST ALONG
THE THERMAL BOUNDARY LEFT BEHIND TODAY/S WAVE. IT LOOKS LIKE WINDS
WILL EVEN TURN NORTH OR NORTHEAST IN BILLINGS BY AFTERNOON...SO WE
WILL PROBABLY GET IN ON SOME LIGHT SNOW HERE TOO. WE HAD ENOUGH IN
THE WAY OF CONFIDENCE IN THIS WHOLE SCENARIO TO SIGNIFICANTLY RAMP
UP POPS IN MANY AREAS...GOING AS FAR AS 80 PERCENT FROM MILES CITY
TO HYSHAM AND DOWN TOWARD LAME DEER AND LODGE GRASS. THIS LOOKS TO
BE A GOOD 1 TO 2 INCH SNOW EVENT IN MANY AREAS. SCHULTZ
.LONG TERM...VALID FOR WED...THU...FRI...SAT...SUN...
NORTHWEST FLOW ALOFT ON WEDNESDAY SLOWLY BECOMES A MORE WESTERLY
FLOW ON THURSDAY WHICH WILL ALLOW A LEESIDE SURFACE PRESSURE
TROUGH TO BE THE DOMINANT FEATURE EAST OF THE CONTINENTAL DIVIDE.
THIS PATTERN HOLDS UNTIL LATER ON FRIDAY WHEN AN UPPER LEVEL RIDGE
BUILDING INTO THE PACIFIC NORTHWEST TURNS THE FLOW NORTHWESTERLY
OVER MONTANA AND WYOMING. AT SOME POINT COLDER AIR OVER THE
DAKOTAS WILL HAVE A CHANCE TO PUSH A BACKDOOR COLD FRONT INTO
SOUTHERN MONTANA BUT WHEN IS NOT EXACTLY SURE...WHETHER IT WILL BE
FRIDAY NIGHT OR SATURDAY NIGHT. THIS IS THE BEST CHANCE FOR SNOW
IN THE PLAINS DURING THE EXTENDED PERIOD...THOUGH THE MODELS WILL
HAVE CHANCES FOR OROGRAPHIC SHOWERS AS THE FLOW ALOFT CONTINUES TO
BE FAIRLY MOIST.
TEMPERATURES WEDNESDAY THROUGH FRIDAY ARE GOING TO BE GOVERNED BY
A COUPLE OF FACTORS. DOWNSLOPE WINDS WILL BE FAVORED ACROSS THE
WESTERN AND CENTRAL ZONES BUT AIR WEST OF THE DIVIDE IS SO COLD
THAT THE WARMUP WILL BE MUCH SLOWER THAN NORMAL FOEHN WINDS WOULD
CREATE. ALSO...SNOW COVER WILL REGULATE A PART OF THE WARMUP AND
THE POSITION OF THE SURFACE TROUGH WILL SHOW THE EASTWARD EXTENT
OF THE BEST WARMING WITH TEMPERATURES STAYING COOLER EAST OF THE
TROUGH. BY THE WEEKEND THE PUSH WESTWARD OF THE COLD FRONT WILL
SUPPORT A DROP OF TEMPERATURES BUT AGAIN HOW FAR WEST AND HOW
DRAMATIC IS STILL NOT CERTAIN. WITH COLDER AIR POOLED UP WEST OF
THE DIVIDE WIND IS GOING TO BE A OMNIPRESENT FEATURE FOR THE
WESTERN ZONES. BORSUM
&&
.AVIATION...
FAST MOVING COLD FRONT WILL MOVE THROUGH EASTERN AND CENTRAL
MONTANA BRINGING INCREASED WINDS...BLOWING SNOW AND SNOW SHOWERS.
BEST CHANCE FOR SNOW WILL BE FOR EASTERN MONTANA WITH BLOWING SNOW
BEING THE BIGGEST PROBLEM FOR KBIL AND KLVM. VERY STRONG WINDS ARE
POSSIBLE FOR KLVM WITH DRIFTING AND BLOWING SNOW CREATING IFR
CONDITIONS AT TIMES. KBIL WILL SEE WINDS GUSTS TO 45 MPH WITH MVFR
CONDITIONS DUE TO BLOWING SNOW. KMLS WILL SEE LOWER CEILINGS IN
THE SNOW SHOWERS WITH IFR CONDITIONS AT TIMES. KSHR WILL SEE
CONDITIONS STAY MOSTLY VFR BUT WILL APPROACH MVFR CONDITIONS LATER
IN THE AFTERNOON. BORSUM
&&
.PRELIMINARY POINT TEMP/POPS...
TDY TUE WED THU FRI SAT SUN
-------------------------------------------------------
BIL 019 014/023 005/029 020/033 018/034 015/034 024/036
1/Q 16/S 51/B 11/B 11/B 11/B 11/B
LVM 016 010/022 007/026 020/032 021/034 019/032 024/033
2/J 24/S 42/J 11/N 12/J 11/B 11/N
HDN 022 012/022 901/027 014/035 015/032 012/032 022/036
2/J 28/S 51/B 11/B 11/E 11/B 12/B
MLS 020 009/016 907/023 010/031 013/026 010/028 020/035
9/J 38/S 21/B 11/B 12/J 11/B 22/B
4BQ 020 011/020 903/022 011/034 017/031 012/032 023/036
8/J 47/S 21/B 00/B 01/B 11/B 22/B
BHK 016 009/013 910/017 009/029 012/022 010/027 018/033
9/J 56/S 11/B 01/B 11/B 11/E 12/B
SHR 023 008/024 901/027 014/036 016/034 014/033 022/038
2/J 25/S 51/B 01/B 12/J 11/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 AM MST TUESDAY FOR
ZONES 28-29-34-35-39-41-42-56-63-65-66.
WIND CHILL ADVISORY IN EFFECT UNTIL 11 AM MST THIS MORNING
FOR ZONES 30>33-36>38-57-58.
WINTER WEATHER ADVISORY IN EFFECT UNTIL 11 PM MST THIS
EVENING FOR ZONES 30>33-36>38-57-58.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS RALEIGH NC
1250 PM EST MON DEC 9 2013
.SYNOPSIS... A SLOW-MOVING FRONTAL SYSTEM WEST OF THE APPALACHIANS
THIS MORNING WILL DRIFT ACROSS OUR REGION TONIGHT AND TUESDAY.
CHILLY HIGH PRESSURE WILL BUILD INTO OUR REGION TUESDAY NIGHT AND
WEDNESDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1000 AM MONDAY...
NOT A LOT OF CHANGE NEEDED TO THE FORECAST THIS MORNING. THE CAD
AIRMASS IS FAIRLY WELL ENTRENCHED AND WILL STRUGGLE TO ERODE TODAY.
WHILE THE DEPTH OF THE RESIDUAL COLD POOL HAS DECREASED ON THE 12Z
KGSO RAOB...THERE IS STILL A UNIFORM 40KT FLOW AT 850MB AND ENOUGH
WARM ADVECTION TO KEEP STATIC STABILITY STRONG AND THE CAD LOCKED
IN. RAP AND HRR SOUNDINGS KEEP THE ENTIRE CWA MURKY WELL ON INTO
TONIGHT. THE CURRENT TEMP FORECAST IS AT THE LOWEST END OF THE
GUIDANCE SPECTRUM...SHOWING TEMPS RANGING FROM LOWER 40S TO UPPER
50S. THE BIGGEST POTENTIAL FOR ERROR WILL BE BETWEEN THE TRIANGLE
AND THE COASTAL PLAIN AS THE CAD BOUNDARY TRIES TO RETREAT NORTH AND
WESTWARD. REGARDING POPS...THE AXIS OF DEEPEST MOISTURE IS
CURRENTLY OVER WESTERN NC...AHEAD OF THE SLOW MOVING COLD FRONT WEST
OF THE MOUNTAINS. THE NARROW RAIN BAND THAT CURRENTLY EXTENDS FROM
WEST OF KCLT TO KGSO AND AND INTO VA APPEARS TO BE LINKED TO
ISENTROPIC LIFT BETWEEN 295K AND 305K...WHICH WEAKENS THIS AFTERNOON
AS ANOTHER WAVE OF LOW PRESSURE BEGINS TO FORM TO OUR SOUTHWEST
ALONG THE FRONT. EVEN IF A LULL DEVELOPS...DRIZZLE WILL
CONTINUE...SO HIGH POPS WILL BE MAINTAINED....PARTICULARLY WEST OF
HWY 1. -SMITH
TONIGHT: S/W ENERGY OVER THE CENTRAL ROCKIES WILL PUSH EASTWARD
TODAY INTO TONIGHT... HELPING TO PUSH A COLD FRONT EASTWARD TOWARDS
OUR REGION... WITH A SURFACE LOW DEVELOPING ALONG THE WEDGE FRONT
(AHEAD OF THE APPROACHING COLD FRONT) SOMEWHERE ACROSS OUR
SOUTHEAST/JUST TO THE SOUTH OF OUR REGION LATE TONIGHT. THIS SURFACE
LOW AND CONTINUED MID LEVEL S/W ENERGY EMBEDDED IN THE SOUTHWESTERLY
MID LEVEL FLOW WILL HELP SUPPORT A GOOD CHANCE OF RAIN AREAWIDE.
TEMPS MAY ACTUALLY RISE OR HOLD STEADY OVERNIGHT WHERE THE CAD HOLDS
TODAY. WILL GO WITH LOWS RANGING FROM THE LOW TO MID 40S NW TO LOW
TO MID 50S SE. -BSD
&&
.SHORT TERM /TUESDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM MONDAY...
TUESDAY...THE SURFACE LOW THAT DEVELOPS ALONG A FRONT SITUATED SW-NE
ACROSS CENTRAL NC WILL AID TO ENHANCE LOW LEVEL CONVERGENCE OVER OUR
REGION. ALOFT...A STRONG JET STREAKING ACROSS THE EASTERN LAKES INTO
SOUTHERN NEW ENGLAND WILL INCREASE UPPER LEVEL DIVERGENCE OVER THE
VIRGINIAS AND NC WHILE THE MID LEVEL S/W RESPONSIBLE FOR GENERATING
THE SURFACE WAVE OVERHEAD WILL QUICKLY SHEAR NEWD ACROSS THE TN AND
MID OH VALLEY. THE COMBINATION OF THE AVAILABLE LIFT AND MOISTURE
SUGGEST RAIN SHOULD BE WIDESPREAD ACROSS THE REGION TO START THE DAY
TUESDAY. MODEL GUIDANCE HAS VARIED AS TO WHERE THE AXIS OF
"HEAVIEST" PRECIP (A QUARTER TO A HALF INCH) WILL SET-UP.
HOWEVER...00Z GFS AND ECMWF HAVE COME INTO BETTER
AGREEMENT...FAVORING THE EASTERN PIEDMONT AND COASTAL PLAIN.
STILL...BETTER DYNAMICS ALOFT WILL RESIDE OVER THE NW PIEDMONT. AT
THIS TIME PLAN TO BROADBRUSH THE PRECIP AMOUNTS ACROSS THE REGION
WITH TWO TO THREE TENTHS EXPECTED IN THE 12Z-18Z TUESDAY TIME FRAME.
MID LEVEL S/W WILL QUICKLY SHEAR OUT TO THE NE TUESDAY
AFTERNOON...PROPELLING THE SURFACE FRONT EASTWARD TO THE COAST BY
TUESDAY AFTERNOON. THUS...SHOULD SEE PRECIP TAPER OFF WEST-TO-EAST
TUESDAY AFTERNOON ACROSS CENTRAL NC. DEVELOPING NW FLOW IN THE LOWER
LEVELS WILL LEAD TO DECREASING CLOUDINESS LATE IN THE DAY.
DEVELOPING DOWNSLOPE FLOW WILL INITIALLY OFFSET COLD AIR ADVECTION.
RESIDUAL CAD AIR MASS ACROSS THE NORTH-NW PIEDMONT SHOULD HOLD TEMPS
IN THE 40S. EXPECT WARMER TEMPS OVER THE SOUTHERN COUNTIES WHERE
TEMPS IN THE 50S (AROUND 60 FAR SE) PROBABLE.
COLDER DRIER AIR WILL OVERSPREAD CENTRAL NC TUESDAY NIGHT AS A
MODIFIED CANADIAN HIGH PRESSURE SYSTEM BUILDS INTO THE REGION.
PARENT HIGH EXPECTED TO BE CENTERED OVER THE CENTRAL APPALACHIANS BY
EARLY WEDNESDAY WITH A SURFACE RIDGE EXTENDING INTO NC. THUS...WHILE
EARLY TUESDAY EVENING WILL BE A BIT BREEZY...LOOKS PLAUSIBLE FOR SFC
WINDS TO DECOUPLE AFTER MIDNIGHT. THIS WILL ALLOW TEMPS TO FALL INTO
THE 20S BY DAYBREAK WEDNESDAY ACROSS THE NORTH...AND NEAR 30 ACROSS
THE SOUTH.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 330 AM MONDAY...
WEDNESDAY THROUGH FRIDAY...RELATIVELY TRANQUIL WEATHER PERIOD
ANTICIPATED FROM MID WEEK TO THE END OF THE WEEK AS BROAD UPPER
TROUGH COVERS THE EASTERN TWO-THIRDS OF THE NATION. THE NORTHERN
BRANCH WILL BE DOMINATE IN THE BEGINNING...KEEPING THE STORM TRACK
MAINLY ACROSS THE NORTHERN PLAINS-GREAT LAKES AND NEW ENGLAND. THE
SURFACE HIGH THAT COVERS OUR REGION WEDNESDAY WILL QUICKLY SCOOT EWD
BY LATE WEDNESDAY BUT IS REPLACED BY ANOTHER CHILLY HIGH THAT BUILDS
INTO THE MID ATLANTIC IN THE WAKE OF A MID LEVEL S/W CROSSES THE
GREAT LAKES INTO NEW ENGLAND. THUS OUR CURRENT STRETCH OF BE LOW
NORMAL TEMPS WILL CONTINUE. HIGH TEMPS WED AND THU WILL BE IN THE
40S WHILE MIN TEMPS WILL BE IN THE 20S TO AROUND 30.
SATURDAY INTO SUNDAY...OPERATIONAL GFS AND ECMWF OFFER A SIMILAR
SOLUTION FOR THE UPCOMING WEEKEND WEATHER PATTERN...IN SHARP
CONTRAST TOT E 12Z MODEL RUNS WHICH DEPICTED A SOLUTION VERY SIMILAR
TO OUR CURRENT WEATHER PATTERN. MODEL GUIDANCE NOW ADVERTISING A
RETURN FLOW REGIME BECOMING ESTABLISHED FRIDAY NIGHT INTO
SATURDAY...AHEAD OF A FRONTAL SYSTEM DOMINATED BY A S/W IN THE
NORTHERN STREAM. THIS FRONTAL SYSTEM CROSSES OUR REGION SATURDAY
NIGHT WITH CHILLY HIGH PRESSURE BUILDING INTO OUR REGION SUNDAY. FOR
NOW WILL CONFINE THE BEST CHANCE FOR PRECIP TO SATURDAY AND KEEP IT
ALL LIQUID. IF PRECIP COMES INTO THE REGION EARLY ENOUGH FRIDAY
NIGHT...MAY START OUT AS A WINTRY MIX BEFORE QUICKLY TRANSITIONING
TO ALL RAIN. TEMPS EXPECTED TO REMAIN BELOW NORMAL AND HIGHLY
DEPENDENT UPON PRECIP COVERAGE. HIGHS IN THE 40S TO AROUND 50. LOWS
TEMPS IN THE 30S FRIDAY NIGHT AND 30S TO AROUND 40 SATURDAY NIGHT.
&&
.AVIATION /18Z MONDAY THROUGH FRIDAY/...
AS OF 1250 PM MONDAY...
WITH A PERSISTENT MOIST SOUTHWESTERLY FLOW IN PLACE...LOW CLOUDS
CONTINUE TO CAUSE LIFR CONDITIONS THIS AFTERNOON WITH POCKETS OF
RAIN...DRIZZLE AND LOW VSBYS. THERE IS HIGH CONFIDENCE THAT AT
LEAST IFR CONDITIONS WILL CONTINUE...AND IT IS VERY POSSIBLE THAT
LIFR CONDITIONS MAY PERSIST THROUGH THE NIGHT. A COLD FRONT WILL
SLIP INTO NC FROM THE NORTH-NORTHWESTER LATE TONIGHT...WITH WINDS
TURNING TO NORTHERLY BEHIND THE FRONT. MEANWHILE...A 40-50KT LOW
LEVEL JET WILL SURGE BACK ACROSS THE AREA..CAUSING PRECIP TO
CONTINUE BEHIND THE FRONT. IMPROVEMENT IN CEILINGS AND VSBYS WONT
BEGIN UNTIL AFTER AROUND 18Z TUESDAY OR THEREAFTER. LOW LEVEL WIND
SHEAR SHOULD DIMINISH THIS EVENING AS WINDS ABOVE THE SURFACE
RELAX...BUT WILL REDEVELOP TONIGHT WITH THE ARRIVAL OF THE LOW-LEVEL
JET ATOP WEAK SURFACE WINDS.
LOOKING AHEAD: VFR CONDITIONS WILL RETURN TUE NIGHT AS DRY HIGH
PRESSURE BUILDS INTO THE REGION FROM THE WEST. VFR/DRY CONDITIONS
ARE EXPECTED TO PREVAIL THROUGH THE REMAINDER OF THE WORK WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...BSD/SMITH
SHORT TERM...WSS
LONG TERM...WSS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS BISMARCK ND
128 PM CST MON DEC 9 2013
.UPDATE...
ISSUED AT 121 PM CST MON DEC 9 2013
BLIZZARD WARNING AND WINTER WEATHER ADVISORIES WILL BE IN EFFECT
AT 3 PM CST THIS AFTERNOON. WAITING FOR THE SUBSIDENCE TO SWEEP
ACROSS THE REGION AND CREATE BLOWING SNOW. SATELLITE PICTURES
DEPICT THIS SUBSIDENCE FROM SASKATCHEWAN INTO NORTHEAST MONTANA.
THE CENTER OF LOW PRESSURE NOW CLOSE TO THE NORTHWEST CORNER OF
ND. THE LOW WILL TRACK SOUTHEAST TO NEAR MAX BY 5 PM BASED ON 18Z
RUC THEN TO NORTHERN STUTSMAN COUNTY BY 7 PM CST. THIS WILL PUT THE
WEST CENTRAL AND SOUTHWEST IN THE STRONG PRESSURE GRADIENT WITH
ADDED PRESSURE RISE TO RAISE WIND GUSTS.
CANCELLED THE WIND CHILL ADVISORY FOR THE AFTERNOON. THOUGH THE
WIND CHILLS WOULD REMAIN COOLER FOR A FEW HOURS BUT THEY ARE NOW
MOVING ABOVE -25 MOST AREAS.
UPDATE ISSUED AT 1047 AM CST MON DEC 9 2013
WILL UPGRADE THE ADVISORY TO A BLIZZARD WARNING FOR THE WEST
CENTRAL...SOUTHWEST AND FAR SOUTH CENTRAL. ALSO ADDING ANOTHER
TIER OF COUNTIES INTO THE WINTER WEATHER ADVISORY...INCLUDING
EMMONS BURLEIGH AND SHERIDAN. EXAMINED MODEL SOUNDINGS AND SEE
STRONG POTENTIAL FOR 45 MPH WIND GUSTS WITH THE ALBERTA CLIPPER
ACROSS THE SOUTHWEST. ALSO...SUPERSATURATED WITH RESPECT TO ICE IN
THE DENDRITIC GROWTH ZONE FROM THE BOUNDARY LAYER TO 700 MB. WITH
THAT IN MINE SEE POTENTIAL TO GENERATE A BURST OF SNOWFALL WITH
THE SYSTEM. NOT MUCH MORE THAN 1 TO 2 INCHES BUT ADDING THE SNOW TO
THE WINDS AND SNOW ON GROUND SHOULD LOWER VISIBILITIES TO LESS THAN
A QUARTER MILE. THE ONLY NEGATIVE I SEE IS THE FACT THAT COLD
DENSE AIR IS IN PLACE..AND THIS COULD LIMIT THE TRANSFER OF
MOMENTUM. OTHERWISE...MOST INGREDIENTS ARE IN PLACE FOR A 3 TO 5
HOUR PERIOD OF BLIZZARD CONDITIONS ACROSS THE WEST CENTRAL AND
SOUTHWEST BEGINNING AROUND 3 AND EXTENDING INTO THE MID EVENING.
BLIZZARD CONDITIONS MAY TAKE A FEW MORE HOURS...AROUND 5 PM OR SO
TO REACH SIOUX COUNTY.
UPDATE ISSUED AT 638 AM CST MON DEC 9 2013
NO CHANGES TO THE EARLY MORNING FORECAST ARE NEEDED AT THIS TIME.
ARCTIC HIGH PRESSURE CENTERED OVER EASTERN MONTANA IS PRODUCING
MOSTLY CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY
THIS MORNING. TEMPERATURES AT 6 AM CST WERE GENERALLY 10 TO 20
BELOW WITH WIND CHILLS OF 20 TO 35 BELOW. THE WIND CHILL ADVISORY
CONTINUES THROUGH NOON TODAY. OUR NEXT WEATHER SYSTEM IS CURRENTLY
TAKING SHAPE OVER ALBERTA. THE 10 UTC HRRR IS INDICATING LIGHT
SNOW MOVING INTO WESTERN NORTH DAKOTA BETWEEN 17 AND 18
UTC...WHICH LINES UP WELL WITH THE LATEST FORECAST POPS. STRONGER
WINDS ARE ALSO PROGGED BY THE HRRR TO MOVE INTO KDIK AND KISN
AROUND 21 UTC WHICH IS WHEN THE BLOWING SNOW ADVISORY BEGINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST MON DEC 9 2013
THE HIGHLIGHTS OF THE SHORT TERM ARE DANGEROUS MORNING WIND
CHILLS...FOLLOWED BY BLOWING SNOW THIS AFTERNOON AND EVENING.
THE WIND CHILL ADVISORY REMAINS IN EFFECT FOR ALL OF WESTERN AND
CENTRAL NORTH DAKOTA THROUGH 18 UTC AS WIND CHILLS TO -35 F WILL
CONTINUE THIS MORNING. WIND CHILLS CLIMB ABOVE THE -25 F THRESHOLD
FOR ALL LOCATIONS EXCEPT POSSIBLY THE TURTLE MOUNTAINS THIS
AFTERNOON.
OTHERWISE...AN ALBERTA CLIPPER WILL PROPAGATE ACROSS NORTH CENTRAL
INTO SOUTHEAST NORTH DAKOTA LATE THIS AFTERNOON AND INTO THE
EVENING. THE AREA OF GREATEST CONCERN IS WEST OF THE SURFACE LOW
ACROSS WESTERN AND PORTIONS OF NORTH CENTRAL NORTH DAKOTA WHERE A
WINTER WEATHER ADVISORY IS IN EFFECT FOR THIS AFTERNOON AND
EVENING. THE 00 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A
BAND OF LIGHT SNOW ALONG AND WEST OF THE SURFACE LOW TRACK...WITH
NEW SNOWFALL AMOUNTS OF GENERALLY ONE INCH OR LESS OF VERY
FLUFFY...DRY SNOW GIVEN THE COLD TEMPERATURES. STRONG NORTHWEST
WINDS ARE ALSO EXPECTED FOR THESE AREAS...GENERALLY AS THE FALLING
SNOW IS ENDING. BASED ON THE 00 UTC NAM/GFS BUFR SOUNDINGS...THE
STRONGEST WINDS ARE EXPECTED ACROSS THE SOUTHWEST WHERE ADIABATIC
LAPSE RATES TO 850-800 MB WITH 45-50 KTS OF WIND AT THE TOP OF THE
MIXED LAYER ARE EXPECTED. THE ONE CAVEAT TO MAXIMIZING WIND GUSTS
WILL BE THE RELATIVE LACK OF STRONG COLD AIR ADVECTION...WITH
PERHAPS VERY WEAK WARM AIR ADVECTION BY EVENING. DID CONSIDER THE
POTENTIAL FOR A GROUND BLIZZARD. HOWEVER...AT THIS TIME COMPACTED
SNOW DEPTHS OF 2 TO 6 INCHES ACROSS MUCH OF WESTERN NORTH DAKOTA
AND THE STRONGEST WINDS NOT OCCURRING AT THE SAME TIME AS THE
HEIGHT OF THE FALLING SNOW SHOULD LIMIT BLIZZARD CRITERIA BEING
MET. THAT SAID...WIDESPREAD BLOWING SNOW AND REDUCED VISIBILITIES
TO ONE HALF MILE ARE EXPECTED...AND CONDITIONS WILL HAVE TO BE
MONITORED CLOSELY SHOULD A BLIZZARD WARNING BE NEEDED. THE AREA
MOST FAVORED FOR THIS POTENTIAL IS THE AMIDON...RHAME AND MARMARTH
AREAS WHERE THE SNOW PACK IS LOCALLY GREATER AND WINDS ARE
EXPECTED TO BE THE STRONGEST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 332 AM CST MON DEC 9 2013
THE MAIN FORECAST CONCERNS IN THE LONG TERM WILL BE POSSIBLE BLOWING
SNOW HIGHLIGHTS ON TUESDAY...THEN TEMPERATURES AND LIGHT SNOW
CHANCES THURSDAY THROUGH SUNDAY NIGHT ALONG AN UNDULATING BAROCLINIC
ZONE OVER THE NORTHERN PLAINS.
CURRENT WINTER WEATHER ADVISORY FOR BLOWING SNOW GOES THROUGH 06 UTC
TUESDAY. IT APPEARS THAT THE STRONGEST BOUNDARY LAYER WINDS WILL BE
MOVING THROUGH CENTRAL NORTH DAKOTA AROUND 06 UTC. WINDS SHOULD
WEAKEN THROUGH 12 UTC TUESDAY AS THE COLD ADVECTION ENDS AND
PRESSURE FALL RISE COUPLET HAS MOVED EAST OF THE AREA. WINDS
INCREASE AGAIN ON TUESDAY AS ANOTHER PIECE OF ARCTIC HIGH PRESSURE
DROPS INTO THE AREA. WINDS WILL NOT BE AS STRONG AS MONDAY AND WE
SHOULD GET A GOOD IDEA ON THE IMPACTS OF THE BLOWING SNOW MONDAY TO
DISCERN WHETHER OR NOT THE ADVISORY WILL NEED TO BE EXTENDED INTO
TUESDAY. THEREFORE WILL NOT ISSUE ANYTHING AT THIS TIME.
COLD AND DRY ON WEDNESDAY AS THE ARCTIC HIGH TRACKS SOUTHEAST ACROSS
THE FORECAST AREA.
THURSDAY THROUGH SUNDAY NIGHT A NORTHWEST FLOW PATTERN TAKES SHAPE.
SHORTWAVES MOVING THROUGH THE MEAN FLOW WILL INDUCE LEE SIDE LOW
PRESSURE SYSTEMS THAT WILL TRACK SOUTHEAST FROM THE NORTHERN HIGH
PLAINS INTO THE CENTRAL AND NORTHERN PLAINS. EACH LOW WILL PRODUCE
AN AREA OF LIGHT WARM ADVECTION SNOWS OVER WESTERN AND CENTRAL NORTH
DAKOTA AS THE RIDE SOUTHEAST ALONG THE BAROCLINIC ZONE. IN
ADDITION...EACH WAVE SHOULD BRING IN A LITTLE WARMER AIR...WITH
HIGHS POSSIBLY CLIMBING ABOVE FREEZING BY SUNDAY OVER THE SOUTHWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 121 PM CST MON DEC 9 2013
MAIN HAZARD TO AVIATION WILL BE STRONG WINDS...AND BLIZZARD
CONDITIONS ACROSS THE SOUTHWEST AND WEST CENTRAL...IMPACTING
PRIMARILY KDIK...BUT KISN-KBIS WILL BE IN THE PERIPHERY. MAIN
TIMING WILL BE BETWEEN 3 PM AND MIDNIGHT. OUTSIDE OF THIS
AREA...MVFR TO OCNLY IFR CONDITIONS AFTER 21Z WILL BE FOUND IN
AREAS OF SNOW AND BLOWING SNOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR
NDZ001>004-009>012-019>022-034-035-046.
BLIZZARD WARNING UNTIL MIDNIGHT CST /11 PM MST/ TONIGHT FOR
NDZ017-018-031>033-040>045.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS BISMARCK ND
1102 AM CST MON DEC 9 2013
.UPDATE...
ISSUED AT 1047 AM CST MON DEC 9 2013
WILL UPGRADE THE ADVISORY TO A BLIZZARD WARNING FOR THE WEST
CENTRAL...SOUTHWEST AND FAR SOUTH CENTRAL. ALSO ADDING ANOTHER
TIER OF COUNTIES INTO THE WINTER WEATHER ADVISORY...INCLUDING
EMMONS BURLEIGH AND SHERIDAN. EXAMINED MODEL SOUNDINGS AND SEE
STRONG POTENTIAL FOR 45 MPH WIND GUSTS WITH THE ALBERTA CLIPPER
ACROSS THE SOUTHWEST. ALSO...SUPERSATURATED WITH RESPECT TO ICE IN
THE DENDRITIC GROWTH ZONE FROM THE BOUNDARY LAYER TO 700 MB. WITH
THAT IN MINE SEE POTENTIAL TO GENERATE A BURST OF SNOWFALL WITH
THE SYSTEM. NOT MUCH MORE THAN 1 TO 2 INCHES BUT ADDING THE SNOW TO
THE WINDS AND SNOW ON GROUND SHOULD LOWER VISIBILITIES TO LESS THAN
A QUARTER MILE. THE ONLY NEGATIVE I SEE IS THE FACT THAT COLD
DENSE AIR IS IN PLACE..AND THIS COULD LIMIT THE TRANSFER OF
MOMENTUM. OTHERWISE...MOST INGREDIENTS ARE IN PLACE FOR A 3 TO 5
HOUR PERIOD OF BLIZZARD CONDITIONS ACROSS THE WEST CENTRAL AND
SOUTHWEST BEGINNING AROUND 3 AND EXTENDING INTO THE MID EVENING.
BLIZZARD CONDITIONS MAY TAKE A FEW MORE HOURS...AROUND 5 PM OR SO
TO REACH SIOUX COUNTY.
UPDATE ISSUED AT 638 AM CST MON DEC 9 2013
NO CHANGES TO THE EARLY MORNING FORECAST ARE NEEDED AT THIS TIME.
ARCTIC HIGH PRESSURE CENTERED OVER EASTERN MONTANA IS PRODUCING
MOSTLY CLEAR SKIES ACROSS WESTERN AND CENTRAL NORTH DAKOTA EARLY
THIS MORNING. TEMPERATURES AT 6 AM CST WERE GENERALLY 10 TO 20
BELOW WITH WIND CHILLS OF 20 TO 35 BELOW. THE WIND CHILL ADVISORY
CONTINUES THROUGH NOON TODAY. OUR NEXT WEATHER SYSTEM IS CURRENTLY
TAKING SHAPE OVER ALBERTA. THE 10 UTC HRRR IS INDICATING LIGHT
SNOW MOVING INTO WESTERN NORTH DAKOTA BETWEEN 17 AND 18
UTC...WHICH LINES UP WELL WITH THE LATEST FORECAST POPS. STRONGER
WINDS ARE ALSO PROGGED BY THE HRRR TO MOVE INTO KDIK AND KISN
AROUND 21 UTC WHICH IS WHEN THE BLOWING SNOW ADVISORY BEGINS.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 332 AM CST MON DEC 9 2013
THE HIGHLIGHTS OF THE SHORT TERM ARE DANGEROUS MORNING WIND
CHILLS...FOLLOWED BY BLOWING SNOW THIS AFTERNOON AND EVENING.
THE WIND CHILL ADVISORY REMAINS IN EFFECT FOR ALL OF WESTERN AND
CENTRAL NORTH DAKOTA THROUGH 18 UTC AS WIND CHILLS TO -35 F WILL
CONTINUE THIS MORNING. WIND CHILLS CLIMB ABOVE THE -25 F THRESHOLD
FOR ALL LOCATIONS EXCEPT POSSIBLY THE TURTLE MOUNTAINS THIS
AFTERNOON.
OTHERWISE...AN ALBERTA CLIPPER WILL PROPAGATE ACROSS NORTH CENTRAL
INTO SOUTHEAST NORTH DAKOTA LATE THIS AFTERNOON AND INTO THE
EVENING. THE AREA OF GREATEST CONCERN IS WEST OF THE SURFACE LOW
ACROSS WESTERN AND PORTIONS OF NORTH CENTRAL NORTH DAKOTA WHERE A
WINTER WEATHER ADVISORY IS IN EFFECT FOR THIS AFTERNOON AND
EVENING. THE 00 UTC DETERMINISTIC SUITE IS IN GOOD AGREEMENT ON A
BAND OF LIGHT SNOW ALONG AND WEST OF THE SURFACE LOW TRACK...WITH
NEW SNOWFALL AMOUNTS OF GENERALLY ONE INCH OR LESS OF VERY
FLUFFY...DRY SNOW GIVEN THE COLD TEMPERATURES. STRONG NORTHWEST
WINDS ARE ALSO EXPECTED FOR THESE AREAS...GENERALLY AS THE FALLING
SNOW IS ENDING. BASED ON THE 00 UTC NAM/GFS BUFR SOUNDINGS...THE
STRONGEST WINDS ARE EXPECTED ACROSS THE SOUTHWEST WHERE ADIABATIC
LAPSE RATES TO 850-800 MB WITH 45-50 KTS OF WIND AT THE TOP OF THE
MIXED LAYER ARE EXPECTED. THE ONE CAVEAT TO MAXIMIZING WIND GUSTS
WILL BE THE RELATIVE LACK OF STRONG COLD AIR ADVECTION...WITH
PERHAPS VERY WEAK WARM AIR ADVECTION BY EVENING. DID CONSIDER THE
POTENTIAL FOR A GROUND BLIZZARD. HOWEVER...AT THIS TIME COMPACTED
SNOW DEPTHS OF 2 TO 6 INCHES ACROSS MUCH OF WESTERN NORTH DAKOTA
AND THE STRONGEST WINDS NOT OCCURRING AT THE SAME TIME AS THE
HEIGHT OF THE FALLING SNOW SHOULD LIMIT BLIZZARD CRITERIA BEING
MET. THAT SAID...WIDESPREAD BLOWING SNOW AND REDUCED VISIBILITIES
TO ONE HALF MILE ARE EXPECTED...AND CONDITIONS WILL HAVE TO BE
MONITORED CLOSELY SHOULD A BLIZZARD WARNING BE NEEDED. THE AREA
MOST FAVORED FOR THIS POTENTIAL IS THE AMIDON...RHAME AND MARMARTH
AREAS WHERE THE SNOW PACK IS LOCALLY GREATER AND WINDS ARE
EXPECTED TO BE THE STRONGEST.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 332 AM CST MON DEC 9 2013
THE MAIN FORECAST CONCERNS IN THE LONG TERM WILL BE POSSIBLE BLOWING
SNOW HIGHLIGHTS ON TUESDAY...THEN TEMPERATURES AND LIGHT SNOW
CHANCES THURSDAY THROUGH SUNDAY NIGHT ALONG AN UNDULATING BAROCLINIC
ZONE OVER THE NORTHERN PLAINS.
CURRENT WINTER WEATHER ADVISORY FOR BLOWING SNOW GOES THROUGH 06 UTC
TUESDAY. IT APPEARS THAT THE STRONGEST BOUNDARY LAYER WINDS WILL BE
MOVING THROUGH CENTRAL NORTH DAKOTA AROUND 06 UTC. WINDS SHOULD
WEAKEN THROUGH 12 UTC TUESDAY AS THE COLD ADVECTION ENDS AND
PRESSURE FALL RISE COUPLET HAS MOVED EAST OF THE AREA. WINDS
INCREASE AGAIN ON TUESDAY AS ANOTHER PIECE OF ARCTIC HIGH PRESSURE
DROPS INTO THE AREA. WINDS WILL NOT BE AS STRONG AS MONDAY AND WE
SHOULD GET A GOOD IDEA ON THE IMPACTS OF THE BLOWING SNOW MONDAY TO
DISCERN WHETHER OR NOT THE ADVISORY WILL NEED TO BE EXTENDED INTO
TUESDAY. THEREFORE WILL NOT ISSUE ANYTHING AT THIS TIME.
COLD AND DRY ON WEDNESDAY AS THE ARCTIC HIGH TRACKS SOUTHEAST ACROSS
THE FORECAST AREA.
THURSDAY THROUGH SUNDAY NIGHT A NORTHWEST FLOW PATTERN TAKES SHAPE.
SHORTWAVES MOVING THROUGH THE MEAN FLOW WILL INDUCE LEE SIDE LOW
PRESSURE SYSTEMS THAT WILL TRACK SOUTHEAST FROM THE NORTHERN HIGH
PLAINS INTO THE CENTRAL AND NORTHERN PLAINS. EACH LOW WILL PRODUCE
AN AREA OF LIGHT WARM ADVECTION SNOWS OVER WESTERN AND CENTRAL NORTH
DAKOTA AS THE RIDE SOUTHEAST ALONG THE BAROCLINIC ZONE. IN
ADDITION...EACH WAVE SHOULD BRING IN A LITTLE WARMER AIR...WITH
HIGHS POSSIBLY CLIMBING ABOVE FREEZING BY SUNDAY OVER THE SOUTHWEST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1047 AM CST MON DEC 9 2013
MAIN HAZARD TO AVIATION WILL BE STRONG WINDS...AND BLIZZARD
CONDITIONS ACROSS THE SOUTHWEST AND WEST CENTRAL...IMPACTING
PRIMARILY KDIK...BUT KISN-KBIS WILL BE ION THE PERIPHERY. MAIN
TIMING WILL BE BETWEEN 3 PM AND MIDNIGHT. OUTSIDE OF THIS
AREA...MVFR TO OCNLY IFR CONDITIONS AFTER 21Z WILL BE FOUND IN
AREAS OF SNOW AND BLOWING SNOW.
&&
.BIS WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 3 PM THIS AFTERNOON TO MIDNIGHT CST
TONIGHT FOR NDZ001>004-009>012-019>022-034-035-046.
BLIZZARD WARNING FROM 3 PM CST /2 PM MST/ THIS AFTERNOON TO
MIDNIGHT CST /11 PM MST/ TONIGHT FOR NDZ017-018-031>033-040>045.
WIND CHILL ADVISORY UNTIL 3 PM CST THIS AFTERNOON FOR NDZ003>005-
011>013-022-023-025-036-037-047-048-050-051.
&&
$$
UPDATE...WAA
SHORT TERM...AYD
LONG TERM...TWH
AVIATION...WAA
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
415 PM EST MON DEC 9 2013
.SYNOPSIS...
WEAK SYSTEM LATE TONIGHT INTO TUESDAY WITH SOME SNOW. CHILLY DRY
HIGH PRESSURE WEDNESDAY. ARCTIC FRONT WEDNESDAY NIGHT. ARCTIC HIGH
PRESSURE THURSDAY EXITS FRIDAY. ANOTHER SYSTEM THIS WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
KEPT SOME DZ IN WX GRIDS A FEW MORE HRS THIS AFTN ALONG AND E OF I79
CORRIDOR. THINK THE LOW CRUD STRATUS HOLDS INTO THE OVERNIGHT ACROSS
THE LOWLANDS AND PORTIONS OF THE MTNS. MAY SEE SOME BREAKS ACROSS NE
KY/SE OH AND W LOWLANDS BEFORE FILLING BACK IN LATE AHEAD OF THE
NEXT SYSTEM. TEMPS WILL GRADUALLY FALL TONIGHT WITH POTENTIAL FOR
SOME PATCHY BLACK ICE FOR ANY UNTREATED SURFACES THAT HAVE LINGERING
MOISTURE.
NOW FOR UPCOMING SYSTEM. GFS...NAM AND 00Z RUNS OF HI RESOLUTION
WRFS DEPICT A BAND OF ADVISORY LEVEL SNOW FROM NEAR MT STERLING TO
HUNTINGTON...NE THRU CHARLESTON...CLARKSBURG AND N MTNS. THE
SREF...GEM...AND RUC WOULD HAVE THE HIGHER QPF FURTHER E...CLOSER TO
THE BAROCLINIC ZONE. THIS CREATES TWO CAMPS REGARDING SNOW ACCUMS
WITH ADVISORY LEVEL SNOW FROM THE LATTER GROUP PRIMARILY ACROSS THE
MOUNTAINS. HPC WWD ALSO NOTED THIS SPLIT IN THEIR WINTER QPF GRIDS.
WILL TRY TO TAKE A BLEND WITH THIS WHICH WOULD WARRANT ADVISORIES
FOR ALL OF WV COUNTIES ALONG WITH SW VA AND PORTIONS OF NE KY. THERE
IS ENOUGH AGREEMENT TO LEAVE OUT SE OH AS THIS AREA MAY BE BETWEEN
SFC WAVE AND BAND FROM UPPER LEVEL TROF AS WELL AS GREENUP AND
CARTER AND NEW 18Z NAM ROLLING HAS SHIFTED E MORE IN LINE WITH
SREF/CMC/RUC. NONETHELESS HAVE ISSUED HEADLINES RUNNING FROM 06Z TO
20Z ALTHOUGH THE END TIME MAY BE ABLE TO DROP EARLY.
APPEARS HIGHER AMOUNTS WOULD BE ACROSS THE N LOWLANDS AND N MTNS AS
THE UPPER TROF APPROACHES TO HELP IN SOME MESOSCALE BANDING VIA SOME
SLANTWISE INSTABILITY AND JET DYNAMICS. THIS IS WHERE SOME 2 TO 4
WAS CODED UP FOR C AND N LOWLANDS WITH 3 TO 6 FOR N MOUNTAINS. 1 TO
3 S WV/SW VA WITH LESS THAN AN INCH SE OH TO OH RIVR. BAND WITH THE
UPPER TROF LOOKS TO AFFECT N REACHES OF SE OH COUNTIES...IE
PERRY/MORGAN. ALSO SE WV/BKW...AND SW VA...THERMAL PROFILES INDICATE
POTENTIAL FOR A MIX.
UPPER SYS AND SFC WAVE QUICKLY PULLS E BY 18Z WITH SOME PARTIAL
CLEARING ACROSS SE OH INTO NE KY. HAVE KEPT TEMPS BELOW FREEZING ALL
LOCATIONS TOMORROW WITH ONLY A MODEST REBOUND AFTER THE SNOW MOVES
OUT.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
HAVING TRANSITIONED TO ZONAL UPPER LEVEL FLOW FROM SW JUST PRIOR TO
THE START OF THIS PERIOD...THE FLOW TRANSITIONS FARTHER...TO WNW TO
NW...AS L/W TROUGHING MOVES FROM THE CENTER OF THE CONTINENT TO THE
EASTERN HALF.
FLURRIES IN THE COLD ADVECTION UPSLOPE WNW LOW LEVEL FLOW RIGHT AT
THE START OPF THE PERIOD...WIND DOWN OVERNIGHT...AS HIGH PRESSURE
BUILDS INTO THE S. A CLIPPER SYSTEM / ARCTIC FRONT MOVES THROUGH
LATE WED NT...REINFORCING THE COLD AIR. SNOW SHOWERS WITH THIS
MOISTURE STARVED SYSTEM WILL BE LIMITED TO UPSLOPE IN THE MOUNTAINS
MAINLY IN THE COLD ADVECTION WNW FLOW ONCE THE FRONT PASSES
OVERNIGHT WED NT. ARCTIC HIGH PRESSURE BUILDS IN ON THU.
TEMPERATURES TEN TO FIFTEEN DEGREES BELOW NORMAL THIS PERIOD.
LOWS TUE NT LOOKED GOOD WITH MINOR CHANGES ONLY. BLENDED IN BIAS
CORRECTED ADJMET FOR HIGHS WED...A LITTLE LOWER IN THE N. BLENDED
IN BIAS CORRECTED CONSENSUS MOS FOR LOWS WED NT...A LITTLE HIGHER
WITH CLIPPER COMING THROUGH EXCEPT LITTLE OR NO CHANGE NW IN THE
WAKE OF THE CLIPPER. BLENDED IN ADJMEX AND BIAS CORRECTED
ECMWFHIRES FOR LOWER HIGHS IN THE ARCTIC AIR ON THU.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS SHOWING AN INTERESTING SYSTEM FOR SATURDAY INTO SUNDAY...WITH
POTENTIAL WINTER WEATHER ON THE ONSET. STILL LOTS OF SPREAD IN THE
MODELS HOWEVER...SO WOULD NOT PUT MUCH STOCK IN THE DETAILS AT THIS
TIME. USED A BLEND OF THE GEFS MEAN/ECMWF MEAN/GFS AND ECMWF.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
PRIMARILY MVFR STRATUS INTO TONIGHT WITH SOME IFR CIGS/VSBY IN THE
MOUNTAINS AMID PATCHY DZ. SOME BREAKS POSSIBLE ACROSS SE OH AND NE
KY TONIGHT.
AN UPPER LEVEL TROF WILL APPROACH LATE TONIGHT AND COMBINED WITH A
SURFACE WAVE TO THE SE WILL ALLOW SN OVERSPREAD MUCH OF THE
AREA...HEAVIEST ACROSS THE LOWLANDS AND MOUNTAINS. CIGS WILL LOWER
INTO IFR/LIFR ALONG WITH VSBY AS THE SN MOVES IN 09 TO 15Z. SOME
IMPROVEMENT AFTER 15Z AS CIGS/VSBY RISE INTO MVFR AND TRYING TO
SCT OU ACROSS SE OH/NE KY/W WV IN AFTERNOON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF IFR/LIFR CIGS MAY VARY FROM CURRENT
FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H M M M M M H
BKW CONSISTENCY H H H H L L L L L M H H
EKN CONSISTENCY H H H H H L L L L L L L
PKB CONSISTENCY H H H H H H H H H M M H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z TUESDAY...
IFR POSSIBLE IN SNOW...SLEET...FREEZING RAIN AND RAIN SATURDAY.
&&
.EQUIPMENT...
ADDITIONAL PARTS FOR PARKERSBURG ASOS ARE EXPECTED TO ARRIVE BY TUE
MORNING. AUTOMATED OBSERVATIONS WILL BE UNAVAILABLE UNTIL AT LEAST
TUE.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY FROM 1 AM TO 3 PM EST TUESDAY FOR
WVZ005>011-013>020-024>040-046-047.
OH...NONE.
KY...WINTER WEATHER ADVISORY FROM 1 AM TO 3 PM EST TUESDAY FOR
KYZ103-105.
VA...WINTER WEATHER ADVISORY FROM 1 AM TO 3 PM EST TUESDAY FOR
VAZ003-004.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...30
SHORT TERM...TRM
LONG TERM...RPY
AVIATION...30
EQUIPMENT...TRM
AREA FORECAST DISCUSSION
NWS CHARLESTON WV
305 PM EST MON DEC 9 2013
.SYNOPSIS...
A WEAK SYSTEM CROSSES LATE TONIGHT INTO TUESDAY WITH SOME SNOW
EXPECTED. CHILLY DRY HIGH PRESSURE FOR WEDNESDAY INTO FRIDAY.
ANOTHER SYSTEM THIS WEEKEND.
&&
.NEAR TERM /THROUGH TUESDAY/...
KEPT SOME DZ IN WX GRIDS A FEW MORE HRS THIS AFTN ALONG AND E OF I79
CORRIDOR. THINK THE LOW CRUD STRATUS HOLDS INTO THE OVERNIGHT ACROSS
THE LOWLANDS AND PORTIONS OF THE MTNS. MAY SEE SOME BREAKS ACROSS NE
KY/SE OH AND W LOWLANDS BEFORE FILLING BACK IN LATE AHEAD OF THE
NEXT SYSTEM. TEMPS WILL GRADUALLY FALL TONIGHT WITH POTENTIAL FOR
SOME PATCHY BLACK ICE FOR ANY UNTREATED SURFACES THAT HAVE LINGERING
MOISTURE.
NOW FOR UPCOMING SYSTEM. GFS...NAM AND 00Z RUNS OF HI RESOLUTION
WRFS DEPICT A BAND OF ADVISORY LEVEL SNOW FROM NEAR MT STERLING TO
HUNTINGTON...NE THRU CHARLESTON...CLARKSBURG AND N MTNS. THE
SREF...GEM...AND RUC WOULD HAVE THE HIGHER QPF FURTHER E...CLOSER TO
THE BAROCLINIC ZONE. THIS CREATES TWO CAMPS REGARDING SNOW ACCUMS
WITH ADVISORY LEVEL SNOW FROM THE LATTER GROUP PRIMARILY ACROSS THE
MOUNTAINS. HPC WWD ALSO NOTED THIS SPLIT IN THEIR WINTER QPF GRIDS.
WILL TRY TO TAKE A BLEND WITH THIS WHICH WOULD WARRANT ADVISORIES
FOR ALL OF WV COUNTIES ALONG WITH SW VA AND PORTIONS OF NE KY. THERE
IS ENOUGH AGREEMENT TO LEAVE OUT SE OH AS THIS AREA MAY BE BETWEEN
SFC WAVE AND BAND FROM UPPER LEVEL TROF AS WELL AS GREENUP AND
CARTER AND NEW 18Z NAM ROLLING HAS SHIFTED E MORE IN LINE WITH
SREF/CMC/RUC. NONETHELESS HAVE ISSUED HEADLINES RUNNING FROM 06Z TO
20Z ALTHOUGH THE END TIME MAY BE ABLE TO DROP EARLY.
APPEARS HIGHER AMOUNTS WOULD BE ACROSS THE N LOWLANDS AND N MTNS AS
THE UPPER TROF APPROACHES TO HELP IN SOME MESOSCALE BANDING VIA SOME
SLANTWISE INSTABILITY AND JET DYNAMICS. THIS IS WHERE SOME 2 TO 4
WAS CODED UP FOR C AND N LOWLANDS WITH 3 TO 6 FOR N MOUNTAINS. 1 TO
3 S WV/SW VA WITH LESS THAN AN INCH SE OH TO OH RIVR. BAND WITH THE
UPPER TROF LOOKS TO AFFECT N REACHES OF SE OH COUNTIES...IE
PERRY/MORGAN. ALSO SE WV/BKW...AND SW VA...THERMAL PROFILES INDICATE
POTENTIAL FOR A MIX.
UPPER SYS AND SFC WAVE QUICKLY PULLS E BY 18Z WITH SOME PARTIAL
CLEARING ACROSS SE OH INTO NE KY. HAVE KEPT TEMPS BELOW FREEZING ALL
LOCATIONS TOMORROW WITH ONLY A MODEST REBOUND AFTER THE SNOW MOVES
OUT.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH THURSDAY/...
ACTIVE AT THE OUTSET OF THE PERIOD ON TUESDAY MORNING WITH A
QUICK-HITTING SYSTEM PUSHING ACROSS THE AREA. YET ANOTHER WAVE OF
LOW PRESSURE WILL BE RIDING ALONG THE QUASI-STATIONARY FRONT STILL
TO OUR SOUTHEAST WHICH IS PROGGED TO BE LOCATED NEAR THE TN/NC/GA
AREA AT 12Z TUE. MEANWHILE AN UPPER TROUGH WILL BE PROGRESSING
EASTWARD QUICKLY ACROSS THE LOWER/MID OHIO RIVER VALLEY TUE MORNING.
EXPECT TWO DISTINCT AREAS OF PRECIP AT THE OUTSET...ONE ENTERING THE
SE OHIO ZONES AND THE OTHER PUSHING UP FROM THE SW WITH THE SFC LOW.
THESE SHOULD MERGE OVER THE NORTHEAST ZONES BY MID-LATE MORNING ON
IT/S WAY OUT OF OUR AREA. VARIOUS QPF OUTPUT DEPICTING ROUGHLY
0.1-0.2 INCHES IN GENERAL...WITH SOME HIGHER AMOUNTS PARTICULARLY ON
THE FINER RESOLUTION NAM12. TOUGH CALL ON SNOWFALL AMOUNTS WITH SOME
DIFFERENCES IN TIMING OF THE HIGHEST QPF AND WITH THE SYSTEM BEING
SUCH A FAST-MOVER. A GENERAL INCH OR SO APPEARS REASONABLE FOR MUCH
OF THE LOWLANDS LATE MON NIGHT GOING INTO TUE MORNING. THE AREA
HOWEVER COMES UNDER INFLUENCE OF RIGHT ENTRANCE REGION OF STRONG JET
JUST TO OUR NORTHWEST AROUND THE 12Z TUE TIME FRAME WITH GOOD
UNIDIRECTIONAL SPEED SHEAR. A BIT CONCERNED WITH PROGGED EPV AND
THETA-E LAPSE RATE VALS WITH GOOD SATURATION ABOVE THE COLD
DOME...NOT TO MENTION SOME WEAK ELEVATED CAPE...THAT SOME LOCATIONS
MAY SEE SOME ENHANCEMENT OF SNOWFALL RATES/ACCUMULATIONS IN NARROW
MESOSCALE BANDS THROUGH SLANTWISE AND/OR UPRIGHT CONVECTION.
CONSIDERED AN ADVISORY FOR TUE MORNING...BUT AFTER COLLABORATION
WITH SURROUNDING OFFICES DECIDED TO ALLOW DAY SHIFT ONE MORE LOOK AT
LATEST DATA. DID BUMP UP SNOW AMOUNTS...AGAIN...TO AROUND THE 1-2
INCH RANGE WITH SOME 2-3 ACROSS THE NORTHEAST ZONES. SNOWFALL WILL
PRIMARILY BE CONFINED NEAR THE EASTERN MOUNTAINS BY 18Z TUE WITH
ONLY A SLIGHT CHANCE OF LIGHT SNOW REMAINING BY 00Z WED. ALSO NUDGED
MAX TEMPS DOWN A BIT TUESDAY PER LATEST MOS GUIDANCE AND 925MB TEMPS
SUPPORTING. MANY LOCATIONS TUESDAY WILL STRUGGLE TO REACH THE
FREEZING MARK.
HIGH PRESSURE PUSHES IN FROM THE WEST TUESDAY NIGHT AND WEDNESDAY
WITH RAPIDLY CLEARING SKIES TUESDAY NIGHT WITH HIGH PRESSURE CENTER
LOCATED OVER THE SOUTHERN ZONES BY 12Z WED. CLEARING SKIES AND LIGHT
WINDS WILL ALLOW GOOD COOLING WITH TEENS EXPECTED FOR MOST
LOCATIONS...AND EVEN SOME SINGLE DIGITS POSSIBLE OVER SE OHIO AND OF
COURSE THE EASTERN HIGH COUNTRY. AN UPPER TROUGH WILL PASS BY TO THE
NORTH OF THE FORECAST AREA WEDNESDAY RESULTING IN PERHAPS A FEW MORE
CLOUDS NORTH. BUT OTHERWISE A DRY AND SUNNY...BUT COOL...DAY IS ON
TAP FOR WEDNESDAY. MAX TEMPS GENERALLY IN THE LOW/MID 30S FOR THE
LOWLANDS STILL APPEAR ON TRACK WITH VERY LITTLE CHANGE FROM PREV
FCST. SFC WINDS WILL COME AROUND TO THE SOUTHWEST AS SFC HIGH
CONTINUES TO PUSH OFF TO THE EAST. A QUICK MOVING FRONT WILL PUSH
ACROSS THE AREA WED NIGHT...BUT LITTLE MOISTURE WITH IT RESULTS IN
ONLY A BRIEF INCREASE IN CLOUD COVER AND SOME BREEZY POST-FRONTAL
WINDS WED NIGHT...EXCEPT FOR THE FAR NORTHEAST ZONES WHERE JUST
ENOUGH MOISTURE DEPTH MAY BE ENOUGH TO SQUEEZE OUT A LIGHT SNOW
SHOWER. THUS WILL CARRY SLIGHT CHANCE POPS HERE WED NIGHT. SNOW
ACCUMS WILL NOT BE AN ISSUE HOWEVER...WITH ONLY A DUSTING TO A FEW
TENTHS POSSIBLE. MINS AGAIN WILL BE JUST ABOUT IDENTICAL TO TUE
NIGHT/S...WITH TEENS EXPECTED FOR MOST LOWLANDS AND PERHAPS LOWER
20S FOR THE COALFIELDS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
MODELS SHOWING AN INTERESTING SYSTEM FOR SATURDAY INTO SUNDAY...WITH
POTENTIAL WINTER WEATHER ON THE ONSET. STILL LOTS OF SPREAD IN THE
MODELS HOWEVER...SO WOULD NOT PUT MUCH STOCK IN THE DETAILS AT THIS
TIME. USED A BLEND OF THE GEFS MEAN/ECMWF MEAN/GFS AND ECMWF.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
PRIMARILY MVFR STRATUS INTO TONIGHT WITH SOME IFR CIGS/VSBY IN THE
MOUNTAINS AMID PATCHY DZ. SOME BREAKS POSSIBLE ACROSS SE OH AND NE
KY TONIGHT.
AN UPPER LEVEL TROF WILL APPROACH LATE TONIGHT AND COMBINED WITH A
SURFACE WAVE TO THE SE WILL ALLOW SN OVERSPREAD MUCH OF THE
AREA...HEAVIEST ACROSS THE LOWLANDS AND MOUNTAINS. CIGS WILL LOWER
INTO IFR/LIFR ALONG WITH VSBY AS THE SN MOVES IN 09 TO 15Z. SOME
IMPROVEMENT AFTER 15Z AS CIGS/VSBY RISE INTO MVFR AND TRYING TO
SCT OU ACROSS SE OH/NE KY/W WV IN AFTERNOON.
FORECAST CONFIDENCE AND ALTERNATE SCENARIOS THROUGH 18Z
TUESDAY...
FORECAST CONFIDENCE: MEDIUM.
ALTERNATE SCENARIOS: TIMING OF IFR/LIFR CIGS MAY VARY FROM CURRENT FORECAST.
EXPERIMENTAL TABLE OF FLIGHT CATEGORY OBJECTIVELY SHOWS CONSISTENCY
OF WFO FORECAST TO AVAILABLE MODEL INFORMATION:
H = HIGH: TAF CONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
M = MEDIUM: TAF HAS VARYING LEVEL OF CONSISTENCY WITH MODELS.
L = LOW: TAF INCONSISTENT WITH ALL MODELS OR ALL BUT ONE MODEL.
UTC 1HRLY 20 21 22 23 00 01 02 03 04 05 06 07
EST 1HRLY 15 16 17 18 19 20 21 22 23 00 01 02
CRW CONSISTENCY H H H H H H H H H H H H
HTS CONSISTENCY H H H H H H M M M M M H
BKW CONSISTENCY H H H H L L L L L M H H
EKN CONSISTENCY H H H H H L L L L L L L
PKB CONSISTENCY H H H H H H H H H M M H
CKB CONSISTENCY H H H H H H H H H H H H
AFTER 18Z TUESDAY...
IFR POSSIBLE IN SNOW MONDAY NIGHT INTO TUESDAY.
&&
.RLX WATCHES/WARNINGS/ADVISORIES...
WV...WINTER WEATHER ADVISORY FROM 1 AM TO 3 PM EST TUESDAY FOR
WVZ005>011-013>020-024>040-046-047.
OH...NONE.
KY...WINTER WEATHER ADVISORY FROM 1 AM TO 3 PM EST TUESDAY FOR
KYZ103-105.
VA...WINTER WEATHER ADVISORY FROM 1 AM TO 3 PM EST TUESDAY FOR
VAZ003-004.
&&
$$
SYNOPSIS...TRM/RPY/30
NEAR TERM...30
SHORT TERM...50
LONG TERM...RPY
AVIATION...30
AREA FORECAST DISCUSSION
NWS PORTLAND OR
1005 AM PST MON DEC 9 2013
.SYNOPSIS...LOWER PRESSURE OFFSHORE CONTINUES TO DRIVE WEAK EASTERLY
FLOW THROUGH THE COLUMBIA GORGE AND INTO THE PORTLAND AREA. A WEAK
CLIPPER SYSTEM WILL PUSH DOWN FROM THE YUKON BRINGING A CHANCE OF
SNOW AND OR FREEZING DRIZZLE MAINLY FOR OUR NORTHERN ZONES INTO
TUESDAY. WEDNESDAY SHOULD REMAIN CHILLY AND DRY...THOUGH A LITTLE
WARMER THAN THE PAST COUPLE DAYS AS OUR AIR MASS SLOWLY MODERATES.
THE NEXT SYSTEM LOOKS STRONGER...AND MAY ENCOUNTER A STUBBORN LOW-
LEVEL COLD AIR MASS AS PRECIPITATION SPREADS ONSHORE. THIS MAY
RESULT IN MORE FROZEN OR FREEZING PRECIPITATION BEFORE A PACIFIC AIR
MASS FINALLY TAKES OVER LATE IN THE WEEK.
&&
.UPDATE...WEAK LOW JUST OFF THE COAST HAVE DEVELOP A BIT OF HYBRID
FREEZING RAIN AND DRIZZLE. A QUICK ANALYSIS OF MODEL SOUNDINGS AND
VERTICAL TEMPERATURE PROFILE ESTIMATED OBSERVATIONS SHOW THE UPPER
LAYER OF THE PRECIP GENERATION REGION (AROUND 850MB) IS SOMEWHERE
AROUND -5 TO -6 DEGREES C...NOT QUITE COLD ENOUGH TO PRODUCE ALL
SNOW AND STILL CLEARLY CAPABLE OF CREATING THE SUPERCOOLED WATER
DROPS. REPORT FROM LONG BEACH IS A LIGHT GLAZE BUT ENOUGH TO IMPACT
TRAVEL. HAVE ADDED A FREEZING DRIZZLE MENTION TO THE ADVISORY PLUS
ADDED THE NORTH OREGON COAST, THE WILLIPA HILLS, AND THE NORTH COAST
RANGE. PRESSURE GRADIENTS ARE STILL INDICATING OFFSHORE FLOW WHICH
WILL LIMIT TEMPERATURES RISES. HAVE DECIDED TO ALSO PULL ALL RAIN
MIX FROM THE FORECAST AS WINDS DO NOT APPEAR TO FAVOR SIGNIFICANT
WARMING. FAIRLY SOLID CLOUD COVER WILL ALSO INHIBIT WARMING.
SEEMS LIKE THIS INITIAL BAND WILL STILL ENCOUNTER DRIER INLAND AIR AS
IT CROSSES THE COAST RANGES LEAVING SOME LIGHT FLURRIES ACROSS THE
METRO AREA. LEFT THE ADVISORY ALONE FOR NOW COVERING THE METRO BUT
DO HAVE CONCERNS FOR A LIGHT FREEZING DRIZZLE TO OCCUR FOR THE
EVENING COMMUTE. LEAVING EARLY FROM WORK WOULD PROBABLY BE A GOOD
IDEA. DONT EXPECT A WIDESPREAD ICING EVENT THIS AFTERNOON/EVENING
BUT WOULD NOT BE SURPRISED TO SEE POCKETS OF LIGHT ICING UNDER
OCCASIONAL FREEZING DRIZZLE MIXED IN WITH THE SHOW SHOWERS.
AM STILL CONSIDERING WHAT TO MAKE OF THE OVERNIGHT CONDITIONS
TONIGHT. A QUICK ANALYSIS SHOWS ANY MIXED FREEZING DRIZZLE WILL
CONVERT BACK TO ALL SNOW AS THE MIDLEVELS COOL OVERNIGHT...EXCEPT
FOR POSSIBLY THE COAST. PRECIP TYPING COULD BECOME MORE COMPLICATED
OVERNIGHT AND EARLY DAYLIGHT TUESDAY FOR THE INLAND AREAS. WILL NEED
TO SPEND MORE TIME WITH ANALYSIS THOUGH. UPDATED ZONES AND GRIDS ARE
ON THEIR WAY. /JBONK
&&
.PREV DISC... /ISSUED 400 AM PST MON DEC 9 2013/
SHORT TERM...TONIGHT THROUGH WEDNESDAY... ONE LAST BITTERLY COLD
NIGHT OUT THERE TONIGHT BEFORE THE SLOW PROGRESSION OUT OF THE
COLD SNAP BEGINS. SEEING SOME OF THAT WITH THE COAST REMAINING
GENERALLY IN THE 20S. IT IS A BALMY 3 DEGREES IN EUGENE AND PLENTY
OF TEENS INLAND. TEMPS AND DEW POINTS ARE UP A LITTLE FROM LAST NIGHT
WHICH SHOULD PREVENT WIDESPREAD SINGLE DIGITS.
LOWER CLOUDS ARE ROLLING INTO THE COAST THIS MORNING...AND KLGX RADAR
DEPICTS SOME SHOWER ACTIVITY OFFSHORE THAT IS SOMEWHAT DYING OUT ON
THE LEADING EDGE. LATEST HI-RES GUIDANCE SUGGESTS THAT NOT A WHOLE
LOT OF INLAND PROGRESS THIS MORNING AS THE FLOW IS STILL MORE
NORTHERLY ALOFT...BUT LIKELY SOME LIGHT SNOW OR FLURRIES FOR THE S
WA/N OR COAST AND COAST RANGE.
A SOMEWHAT CHALLENGING FORECAST COMING UP THE NEXT FEW DAYS AFTER THE
NEAR TERM AS SEVERAL WEAK WAVES MOVE THROUGH BUT MIXED SIGNALS WITH
REGARDS TO PRECIPITATION. COULD SEE SOME VERY LIGHT SNOW/FLURRIES OR
SOME FREEZING DRIZZLE.AFTER THIS MORNING SEVERAL MODELS BRING LIGHT
PRECIPITATION (0.02" QPF OR LESS) INTO THE INTERIOR THIS AFTERNOON.
CURRENT KLGX DATA WOULD SUGGEST THAT PRECIPITATION WILL CONTINUE
WORKING INLAND...BUT MAY HAVE PROBLEMS WITH THE DRY AIR MASS.
MEANWHILE THE HRRR AND NAM KEEP PRECIPITATION CONFINED TO COAST AND
COAST RANGE WHERE TEMPERATURE PROFILES BEGIN TO WARM GIVEN THE WEAK
ONSHORE FLOW TO THE POINT WHERE PRECIP TYPE WOULD CHANGE TO RAIN OR
MAYBE RAIN-SNOW MIX. MEANWHILE INLAND THE PROFILE WILL REMAIN ALL
BELOW FREEZING. AFTER THAT THERE IS A MORE DISTINCT WAVE OFF THE
COAST OF NORTHERN B.C. THAT WILL DROP S.E. AND PROVIDE A BIT MORE
ORGANIZED LIFT TONIGHT INTO EARLY TUESDAY.
THE MOISTURE LAYER LOOKS TO BE RATHER SHALLOW. THESE SITUATIONS TEND
TO FAVOR FREEZING DRIZZLE...BUT ONLY IF YOU TAKE THEM FOR FACE VALUE
AND DO NOT CONSIDER THE INITIAL AIR MASS THAT THE CLOUD FORMED IN OR
THE ARMS THE SATURATED CLOUD IS MOVING INTO. SOUNDINGS SUGGEST THE
TOP OF THE MOIST LAYER AROUND -5 TO -7C. IT IS INCORRECT TO SUGGEST
THAT THERE WILL BE NO ICE CRYSTALS PRESENT IN THE CLOUD EVEN AT THESE
TEMPERATURES...JUST A QUESTION OF IF THERE ARE ENOUGH. CANNOT IGNORE
THE FACT THERE MAY ALSO BE SOME FREEZING DRIZZLE WHICH IF HITTING THE
COLD ROADS WOULD FREEZE LIKE THE SNOW DID THE OTHER DAY. THAT
SAID...AN INVESTIGATION OF DUAL-POLARIZATION DATA FROM KLGX AND
SIMPLY DUE TO THE FACT THAT REFLECTIVITY RETURNS ARE AS HIGH AS 30-40
DBZ SUGGEST THAT P-TYPE...AT LEAST CURRENTLY AND WITH THE FIRST BATCH
COMING IN IS SNOW AND NOT FREEZING DRIZZLE. THE 0Z QUILLAYUTE
SOUNDING DOES SUGGEST A WARM LAYER ABOVE THE MOIST LAYER..
BUT THE POTENTIAL OF FREEZING DRIZZLE CANNOT BE IGNORED AS THE LOWER
LEVEL PROFILE WARMS AND REDUCES ICE CRYSTAL AVAILABILITY ESPECIALLY
TOWARDS TUESDAY. AND ANY ACCUMULATING FREEZING DRIZZLE WOULD WARRANT
AN ADVISORY...ALSO DUE TO THE FACT DEW POINTS WILL BE MUCH HIGHER
MONDAY NIGHT INTO TUESDAY MORNING...ROADS HAVE THE POTENTIAL TO BE
QUITE HAZARDOUS...REGARDLESS OF THE PRECIP TYPE OR HOW MUCH/HOW
LITTLE SNOW ACTUALLY FALLS. SREF PLUMES KEEP ANYWHERE FROM LIGHT SNOW
ACCUMS TO UP TO AN INCH IN THE METRO. MODELS CONTINUE TO FAVOR THE
KELSO/CASTLE ROCK AREA AND THE I-5 CORRIDOR IN WASHINGTON FOR THE
MOST QPF. THEREFORE SEE NO REASON AT LEAST AT THIS TIME TO CHANGE THE
HEADLINE...BUT WILL FOCUS ON FREEZING DRIZZLE/SNOW POTENTIAL AND ROAD
IMPACTS. SINCE THE CENTRAL VALLEY DOES NOT LOOK TO SEE MUCH SNOW...I
CAN FORESEE A SITUATION WHERE IF FREEZING DRIZZLE DOMINATES AND THE
PRECIP GETS A BIT FARTHER SOUTH...THAT AN ADVISORY WOULD BE
WARRANTED...BUT CONFIDENCE IS LOW. DO STILL THINK THAT 1-2" ARE
POSSIBLE IF THE P-TYPE REMAINS SNOW MAINLY NORTH OF THE COLUMBIA
RIVER AND ALSO TOWARDS ST HELENS/SCAPPOOSE. I HOPE THIS DOES NOT
COME BACK TO HAUNT ME...BUT AM CONTEMPLATING TO REMOVING THE CENTRAL
WILLAMETTE VALLEY FROM THE WINTER WX ADVISORY...AS QPF IN THESE
AREAS DOES NOT SUPPORT AT THAT MUCH IN THE WAY OF SNOW. IF FREEZING
DRIZZLE IS THE MORE DOMINANT P-TYPE...THAN AN ADVISORY WOULD THEN BE
WARRANTED. WILL WORK UP THE WSW HERE WITH REFINED TIMING AND
FINAL DECISIONS SHORTLY AND SEND AN AMENDED AFD WITH THE HEADLINES.
THE MAIN JET ENERGY COMING OUT OF WESTERN CANADA SHOULD SHIFT FARTHER
EAST BY WEDNESDAY...ALLOWING SOME CLEARING AND POSSIBLY ANOTHER CLEAR
CALM AND CHILLY MORNING FOR SOME AREAS WED MORNING. EXPECT THERE TO
THEN BE FOG/FREEZING FOG. AFTER BURN OFF AND WITH SOME
SUNSHINE AND A SOMEWHAT MODERATED AIR MASS...MOST AREAS SHOULD BE
ABLE TO GET ABOVE FREEZING WEDNESDAY. HAVE DRIED OUT THE FORECAST
FOR WEDS AND WEDNESDAY NIGHT WITH THE EXPECTED TREND OF BACKING OFF
THE ARRIVAL OF THE PACIFIC SYSTEM WITH A COLD AND STRONG UPPER RIDGE
IN PLACE. /KMD
LEFT PREVIOUS DISCUSSION IN PLACE FOR THE LATTER PART OF THE SHORT
TERM FROM THE EVENING SHIFT AS MUCH OF THIS SHIFT WAS SPENT FINE
TUNING THE DETAILS THROUGH WEDNESDAY NIGHT.... NO DOUBT THIS IS AN
HISTORIC COLD AIR MASS. WHICH BRINGS US TO OUR NEXT FORECAST
CHALLENGE...THE PRECIPITATION TYPE EXPECTED FROM OUR NEXT EVENT.
CONSIDERING THE MAGNITUDE OF COLD ASSOCIATED WITH THIS AIR MASS...IT
IS VERY HARD TO BELIEVE WEAK CLIPPER SYSTEMS WILL BE SUFFICIENT TO
ERODE THE COLD AIR ENTRENCHED OVER THE PACIFIC NORTHWEST. WE CONTINUE
TO DISAGREE WITH MODEL GUIDANCE THAT SUGGESTS THE COLD AIR WILL SCOUR
OUT QUICKLY...AND OUR TEMPERATURE AND PRECIPITATION TYPE FORECAST
REFLECTS THAT ALL THE WAY INTO THURSDAY. WEAGLE
LONG TERM...NO CHANGES TO THE GRIDS OTHER THAN TO BACK OFF ON POPS A
BIT TO START THURSDAY SO REST OF THE DISCUSSION REMAINS
UNCHANGED...WILL LET THE DAY SHIFT REVISIT THE CHANGE IN TIMING AND
IMPACTS ON THERMAL PROFILES...WEDNESDAY NIGHT THROUGH
SUNDAY...OVERALL NO CHANGES TO THE THINKING BEHIND THE EXTENDED
FORECAST. DID SOME MANIPULATION OF THE GRIDS TO ATTEMPT TO BETTER
EXPRESS THE MIXED PRECIPITATION POTENTIAL WITH THE LATE WEEK SYSTEM.
WEAGLE
PREVIOUS DISCUSSION FOLLOWS...THE WELL ESTABLISHED COLD ARCTIC AIR
MASS WILL BEGIN TO MODERATE AS FLOW ALOFT BECOMES MORE WESTERLY.
TEMPERATURES LOOK TO TREND BACK TO SEASONAL NORMALS THROUGH THE
SECOND HALF OF NEXT WEEK. THE 12Z GFS AND ECMWF ARE A BIT SLOWER TO
BRING A SYSTEM ONSHORE EARLY THURSDAY SO HAVE ADJUSTED POP GRIDS TO
REFLECT THIS. FORECAST MODELS BRING THE HEAVIEST PRECIP ONSHORE
MIDDAY THURSDAY...WITH THE GFS SOLUTION ABOUT 6 HOURS FASTER. THERE
REMAINS SOME CONCERN THAT THE MODELS ARE TOO QUICK TO WARM THE AIR
MASS AFTER THIS PERIOD OF RECORD-SETTING COLD...SO IT IS POSSIBLE
THAT THIS PRECIPITATION MAY BEGIN IN THE FORM OF SNOW OR FREEZING
RAIN. THIS IS PARTICULARLY THE CASE FOR UPPER HOOD RIVER...THE
COLUMBIA RIVER GORGE..AND THE NORTHERN WILLAMETTE VALLEY. OTHERWISE
RAIN AND CASCADE SNOW IS EXPECTED TO CONTINUE THROUGH FRIDAY NIGHT.
THERE MAY BE A BRIEF DRY PERIOD AT LEAST PART OF THE DAY SATURDAY AS
LOW LEVEL FLOW WILL TURN SOUTHERLY BEFORE THE THE NEXT SYSTEM
ARRIVES SATURDAY AFTERNOON OR EVENING BRINGING RAIN ACROSS THE
FORECAST AREA.CULLEN
&&
.AVIATION...MAINLY VFR THROUGH 18Z...WITH POCKETS OF IFR IN FOG IN S
WILLAMETTE VALLEY. COAST WILL BE PREDOMINANTLY MVFR IN LIGHT
SNOW...WITH OCCASIONAL IFR IN SNOW POSSIBLE THROUGH EARLY TUESDAY.
FREEZING DRIZZLE IS ALSO POSSIBLE NEAR THE COAST. INLAND FROM KSLE
NORTH EXPECT MVFR IN OCCASIONAL LIGHT SNOW...PRIMARILY AFTER
18Z...WITH IFR IN SNOW POSSIBLE AFTER 03Z. SOUTH OF KSLE WILL BE VFR
THROUGH 00Z.
KPDX AND APPROACHES...VFR WITH LIGHT EAST WINDS. OCCASIONAL MVFR IN
FLURRIES OR LIGHT SNOW TODAY...ESPECIALLY AFTER 18Z. IFR IN SNOW
POSSIBLE LATE TONIGHT AFTER 03Z.
&&
.MARINE...NO UPDATES. PREVIOUS DISCUSSION FOLLOWS. BENIGN WEATHER
THROUGH WED. HIGH PRES OVER PAC NW MAINTAINS LIGHT OFFSHORE FLOW
THROUGH WED. WILL WILL TURN MORE W TO SW TUE AND WED AS HIGH WEAKENS
AND LOWER PRES APPROACHES FROM THE W. SEAS HOLDING AT 2 TO 4 FT
TODAY AND TUE...THEN BUILD SLIGHTLY LATER TUE AND WED.
STRONG COLD FRONT WILL ARRIVE ON THU...WITH S GALES EXPECTED. SEAS
WILL BUILD BACK CLOSER TO 10 FT.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM PST
TUESDAY FOR LOWER COLUMBIA.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR COAST
RANGE OF NORTHWEST OREGON-NORTH OREGON COAST.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 1 PM PST
TUESDAY FOR GREATER PORTLAND METRO AREA.
WA...WINTER WEATHER ADVISORY FROM 1 PM THIS AFTERNOON TO 1 PM PST
TUESDAY FOR I-5 CORRIDOR IN COWLITZ COUNTY.
WINTER WEATHER ADVISORY UNTIL 10 PM PST THIS EVENING FOR SOUTH
WASHINGTON COAST-WILLAPA HILLS.
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO 1 PM PST
TUESDAY FOR GREATER VANCOUVER AREA.
PZ...NONE.
&&
$$
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1124 AM CST MON DEC 9 2013
.UPDATE...
UPDATED FOR 18Z AVIATION DISCUSSION.
&&
.PREV DISCUSSION... /ISSUED 1027 AM CST MON DEC 9 2013/
DISCUSSION...
ANOTHER COLD DAY ON TAP ACROSS THE MIDSOUTH. CLOUDS ARE HANGING
TOUGH AND LATEST RAP SOUNDINGS INDICATE THAT THEY WILL REMAIN FOR
THE REST OF THE DAY. THE LACK OF SUN WILL MAKE IT TOUGH FOR TEMPS
TO CLIMB MUCH SO KNOCKED A COUPLE OF DEGREES OFF SOUTH OF I-40.
UPDATE OUT.
SJM
&&
.PREV DISCUSSION... /ISSUED 442 AM CST MON DEC 9 2013/
WEATHER CONDITIONS WERE CLOUDY AND COLD ACROSS THE MIDSOUTH EARLY
THIS MORNING. PRECIPITATION HAD MOVED OUT OF THE AREA AND ONLY
LIGHT FOG WAS BEING REPORTED IN A FEW SPOTS. THUS A MUCH QUIETER
NIGHT WEATHERWISE THAN LAST NIGHT.
MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE UPCOMING WEEK. THE
BIGGEST DISAGREEMENT IS THAT THE NAM SHOWS A LITTLE MORE
PRECIPITATION AND IS FURTHER NORTH WITH THE PRECIPITATION TONIGHT
THAN THE GFS AND ECMWF. VERY COLD WEATHER WILL CONTINUE THROUGH MUCH
OF THE WORK WEEK WITH ONE MORE THREAT OF FREEZING RAIN AND SLEET
TONIGHT.
FOR TODAY...CLOUDS ARE EXPECTED TO GRADUALLY BREAK UP THIS MORNING
LEAVING PARTIAL SUNSHINE ACROSS THE AREA BY THIS AFTERNOON. ANOTHER
PUSH OF MODIFIED POLAR AIR WILL MOVE INTO THE MIDSOUTH KEEPING IT
VERY COLD ACROSS MOST OF THE REGION. LEFT IN A SLIGHT CHANCE OF RAIN
IN ADVANCE OF THE NEXT SYSTEM ACROSS EXTREME SOUTHERN PORTIONS OF
NORTH MS THIS AFTERNOON...OTHERWISE IT WILL BE A DRY DAY ACROSS THE
MIDSOUTH.
FOR TONIGHT...WEAK SURFACE LOW PRESSURE WILL TRACK TO THE SOUTHEAST
OF THE MIDSOUTH. THIS PLACES THE MIDSOUTH ON THE NORTHWESTERN FRINGE
OF MOST OF THE PRECIPITATION WITH THE HIGHEST POPS AND AMOUNTS
FORECAST THROUGH NORTH MS. GENERALLY TOOK A COMPROMISE BETWEEN THE
VARIOUS MODELS. COLDER AIR WILL CONTINUE TO ADVECT INTO THE AREA
FROM THE NORTHWEST. AS A RESULT...PRECIPITATION WILL BE CHANGING TO
FREEZING RAIN AND SLEET FROM THE NORTHWEST. THERE IS A SLIGHT CHANCE
OF LIGHT SNOW NORTH OF INTERSTATE 40 MAINLY DUE TO AN UPPER LEVEL
TROUGH APPROACHING FROM THE WEST...LITTLE IF ANY ACCUMULATION OF
SNOW IS EXPECTED. ATTM...THINK THE BEST CHANCE FOR ANY ICE
ACCUMULATION FROM FREEZING RAIN AND SLEET WILL BE ALONG AND SOUTH OF
INTERSTATE 40 ACROSS PORTIONS OF WEST TENNESSEE...EAST CENTRAL
ARKANSAS AND NORTH MISSISSIPPI. A WINTER WEATHER ADVISORY MAY NEED
TO BE ISSUED FOR PORTIONS OF THIS AREA LATER TODAY...CONFIDENCE IS
NOT HIGH ENOUGH TO ISSUE AT THIS TIME. ANY ICE ACCUMULATIONS ARE
FORECAST TO BE LIGHT AND LESS THAN 1/10 OF AN INCH. PRECIPITATION
ACROSS MUCH OF NORTH MISSISSIPPI WILL BEGIN AS RAIN MIXED WITH
FREEZING RAIN IN SOME LOCATIONS...GRADUALLY BECOMING FREEZING RAIN
AND SLEET AS COLDER AIR PUSHES IN FROM THE NORTHWEST. ONLY MINOR
IF ANY ACCUMULATIONS OF SLEET ARE EXPECTED.
THE PRECIPITATION WILL MOVE EAST OF THE MIDSOUTH EARLY TUESDAY WITH
STRONG COLD HIGH PRESSURE SETTLING OVER THE MIDSOUTH. THE GOOD NEWS
IS THAT NO MORE PRECIPITATION IS FORECAST UNTIL FRIDAY. QUITE COLD
CONDITIONS ARE FORECAST WEDNESDAY MORNING UNDER MOSTLY CLEAR SKIES
WITH LOWS IN THE TEENS ACROSS A LARGE SECTION OF THE AREA. THE HIGH
PRESSURE SYSTEM WILL MOVE TO THE EAST DURING THE DAY WEDNESDAY WITH
SLIGHTLY LESS COLD TEMPERATURES...BUT DID NOT GO AS WARM AS THE MEX
GUIDANCE INDICATES. ANOTHER SURGE OF MODIFIED ARCTIC AIR WILL PUSH
INTO THE REGION WEDNESDAY NIGHT WITH THURSDAY MORNING FORECAST TO BE
THE COLDEST OF THE WEEK. LOW TEMPERATURES WILL DROP INTO THE TEENS
ACROSS MUCH OF THE AREA WITH LOWER TEENS FOR SOME AREAS. WILL NEED
TO MONITOR WIND CHILL READINGS AS THEY MAY DROP TO NEAR ZERO ACROSS
PORTIONS OF NORTHWEST TN.
A LARGE SCALE UPPER LEVEL TROUGH WILL APPROACH THE MIDSOUTH FROM THE
WEST FRIDAY BRINGING OUR NEXT CHANCE OF PRECIPITATION. AT THIS
TIME...INDICATIONS ARE THAT MOST IF NOT ALL OF THE PRECIPITATION
WILL BE RAIN BUT WILL NEED TO KEEP AN EYE ON THIS IN CASE IT DOES
NOT WARM UP AS QUICKLY AS EXPECTED...ESPECIALLY ACROSS NORTHERN
AREAS. THE UPPER LEVEL TROUGH WILL MOVE ACROSS THE REGION FRIDAY
NIGHT AND EARLY SATURDAY WITH WIDESPREAD RAIN. POPS WILL NEED TO BE
INCREASED IN LATER FORECASTS IF THESE MODEL TRENDS PERSIST. DRY AND
COOLER WEATHER IS FORECAST SUNDAY NIGHT AND MONDAY AS THE TROUGH
MOVES OFF TO THE EAST.
JCL
&&
.AVIATION...
18Z TAF CYCLE
CONFIDENCE INCREASING IN RESPECT TO A BRIEF WINTER WEATHER EVENT
MOVING UP FROM THE SOUTHWEST TONIGHT...AFFECTING MEM...TUP...AND
MKL. A LIGHT SNOW AND SLEET MIX WILL OCCASIONALLY FALL AT MEM AND
MKL STARTING THIS EVENING...AND AT THE SAME TIME PRECIPITATION
WILL START OUT AS A COLD RAIN AT TUP. THEN SOMETIME AFTER MIDNIGHT
FEEL PRECIPITATION WILL START TAPERING OFF WITH THE POSSIBILITY OF
PATCHY FREEZING DRIZZLE FORMING. CIGS WILL BE MAINLY MVFR...WITH
OCCASIONAL IFR CONDITIONS AT TUP. JBR MAY SEE OCCASIONAL VFR
CONDITIONS NEAR SUNSET. WINDS WILL BE NORTHERLY AT 8-12 KTS
BACKING NORTHWESTERLY LATE.
JAB
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 36 24 36 23 / 10 40 10 10
MKL 36 22 35 18 / 10 40 10 10
JBR 32 20 31 19 / 10 20 10 10
TUP 40 29 40 23 / 10 80 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MEMPHIS TN
1027 AM CST MON DEC 9 2013
.DISCUSSION...
ANOTHER COLD DAY ON TAP ACROSS THE MIDSOUTH. CLOUDS ARE HANGING
TOUGH AND LATEST RAP SOUNDINGS INDICATE THAT THEY WILL REMAIN FOR
THE REST OF THE DAY. THE LACK OF SUN WILL MAKE IT TOUGH FOR TEMPS
TO CLIMB MUCH SO KNOCKED A COUPLE OF DEGREES OFF SOUTH OF I-40.
UPDATE OUT.
SJM
&&
PREV DISCUSSION... /ISSUED 442 AM CST MON DEC 9 2013/
WEATHER CONDITIONS WERE CLOUDY AND COLD ACROSS THE MIDSOUTH EARLY
THIS MORNING. PRECIPITATION HAD MOVED OUT OF THE AREA AND ONLY
LIGHT FOG WAS BEING REPORTED IN A FEW SPOTS. THUS A MUCH QUIETER
NIGHT WEATHERWISE THAN LAST NIGHT.
MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE UPCOMING WEEK. THE
BIGGEST DISAGREEMENT IS THAT THE NAM SHOWS A LITTLE MORE
PRECIPITATION AND IS FURTHER NORTH WITH THE PRECIPITATION TONIGHT
THAN THE GFS AND ECMWF. VERY COLD WEATHER WILL CONTINUE THROUGH MUCH
OF THE WORK WEEK WITH ONE MORE THREAT OF FREEZING RAIN AND SLEET
TONIGHT.
FOR TODAY...CLOUDS ARE EXPECTED TO GRADUALLY BREAK UP THIS MORNING
LEAVING PARTIAL SUNSHINE ACROSS THE AREA BY THIS AFTERNOON. ANOTHER
PUSH OF MODIFIED POLAR AIR WILL MOVE INTO THE MIDSOUTH KEEPING IT
VERY COLD ACROSS MOST OF THE REGION. LEFT IN A SLIGHT CHANCE OF RAIN
IN ADVANCE OF THE NEXT SYSTEM ACROSS EXTREME SOUTHERN PORTIONS OF
NORTH MS THIS AFTERNOON...OTHERWISE IT WILL BE A DRY DAY ACROSS THE
MIDSOUTH.
FOR TONIGHT...WEAK SURFACE LOW PRESSURE WILL TRACK TO THE SOUTHEAST
OF THE MIDSOUTH. THIS PLACES THE MIDSOUTH ON THE NORTHWESTERN FRINGE
OF MOST OF THE PRECIPITATION WITH THE HIGHEST POPS AND AMOUNTS
FORECAST THROUGH NORTH MS. GENERALLY TOOK A COMPROMISE BETWEEN THE
VARIOUS MODELS. COLDER AIR WILL CONTINUE TO ADVECT INTO THE AREA
FROM THE NORTHWEST. AS A RESULT...PRECIPITATION WILL BE CHANGING TO
FREEZING RAIN AND SLEET FROM THE NORTHWEST. THERE IS A SLIGHT CHANCE
OF LIGHT SNOW NORTH OF INTERSTATE 40 MAINLY DUE TO AN UPPER LEVEL
TROUGH APPROACHING FROM THE WEST...LITTLE IF ANY ACCUMULATION OF
SNOW IS EXPECTED. ATTM...THINK THE BEST CHANCE FOR ANY ICE
ACCUMULATION FROM FREEZING RAIN AND SLEET WILL BE ALONG AND SOUTH OF
INTERSTATE 40 ACROSS PORTIONS OF WEST TENNESSEE...EAST CENTRAL
ARKANSAS AND NORTH MISSISSIPPI. A WINTER WEATHER ADVISORY MAY NEED
TO BE ISSUED FOR PORTIONS OF THIS AREA LATER TODAY...CONFIDENCE IS
NOT HIGH ENOUGH TO ISSUE AT THIS TIME. ANY ICE ACCUMULATIONS ARE
FORECAST TO BE LIGHT AND LESS THAN 1/10 OF AN INCH. PRECIPITATION
ACROSS MUCH OF NORTH MISSISSIPPI WILL BEGIN AS RAIN MIXED WITH
FREEZING RAIN IN SOME LOCATIONS...GRADUALLY BECOMING FREEZING RAIN
AND SLEET AS COLDER AIR PUSHES IN FROM THE NORTHWEST. ONLY MINOR
IF ANY ACCUMULATIONS OF SLEET ARE EXPECTED.
THE PRECIPITATION WILL MOVE EAST OF THE MIDSOUTH EARLY TUESDAY WITH
STRONG COLD HIGH PRESSURE SETTLING OVER THE MIDSOUTH. THE GOOD NEWS
IS THAT NO MORE PRECIPITATION IS FORECAST UNTIL FRIDAY. QUITE COLD
CONDITIONS ARE FORECAST WEDNESDAY MORNING UNDER MOSTLY CLEAR SKIES
WITH LOWS IN THE TEENS ACROSS A LARGE SECTION OF THE AREA. THE HIGH
PRESSURE SYSTEM WILL MOVE TO THE EAST DURING THE DAY WEDNESDAY WITH
SLIGHTLY LESS COLD TEMPERATURES...BUT DID NOT GO AS WARM AS THE MEX
GUIDANCE INDICATES. ANOTHER SURGE OF MODIFIED ARCTIC AIR WILL PUSH
INTO THE REGION WEDNESDAY NIGHT WITH THURSDAY MORNING FORECAST TO BE
THE COLDEST OF THE WEEK. LOW TEMPERATURES WILL DROP INTO THE TEENS
ACROSS MUCH OF THE AREA WITH LOWER TEENS FOR SOME AREAS. WILL NEED
TO MONITOR WIND CHILL READINGS AS THEY MAY DROP TO NEAR ZERO ACROSS
PORTIONS OF NORTHWEST TN.
A LARGE SCALE UPPER LEVEL TROUGH WILL APPROACH THE MIDSOUTH FROM THE
WEST FRIDAY BRINGING OUR NEXT CHANCE OF PRECIPITATION. AT THIS
TIME...INDICATIONS ARE THAT MOST IF NOT ALL OF THE PRECIPITATION
WILL BE RAIN BUT WILL NEED TO KEEP AN EYE ON THIS IN CASE IT DOES
NOT WARM UP AS QUICKLY AS EXPECTED...ESPECIALLY ACROSS NORTHERN
AREAS. THE UPPER LEVEL TROUGH WILL MOVE ACROSS THE REGION FRIDAY
NIGHT AND EARLY SATURDAY WITH WIDESPREAD RAIN. POPS WILL NEED TO BE
INCREASED IN LATER FORECASTS IF THESE MODEL TRENDS PERSIST. DRY AND
COOLER WEATHER IS FORECAST SUNDAY NIGHT AND MONDAY AS THE TROUGH
MOVES OFF TO THE EAST.
JCL
&&
.AVIATION...
12Z TAF CYCLE
LOW CONFIDENCE TAF FORECAST OVER THE NEXT 24 HOURS. MVFR CEILINGS
SHOULD GRADUALLY LIFT TO VFR CONDS THIS AFTERNOON...EXCEPT FOR TUP
WHERE MVFR CIGS WILL PREVAIL FOR MOST OF THE DAY. LOW AND MID
LEVEL MOISTURE WILL ADVANCE AHEAD OF A SURFACE LOW PRESSURE SYSTEM
THROUGHOUT THE DAY. EVENTUALLY RAIN WILL GRADUALLY SPREAD
NORTHWARD AND OVERRIDE COLD DRY AIR THAT IS MOVING SOUTHEASTWARD.
THIS WILL LEAD TO A CHANCE OF RA CHANGING OVER TO FZRA AND PL AT
MKL...MEM...AND TUP SOMETIME AFTER 03Z. WINDS WILL REMAIN FROM THE
NORTH 8-10 KTS THROUGH THE END OF THE TAF PERIOD. ALL TYPES OF
PRECIPITATION WILL COME TO AN END FOLLOWING THE END OF THIS CYCLE.
AC3
&&
.AVIATION...
&&
.PRELIMINARY POINT TEMPS/POPS...
MEM 36 24 36 23 / 10 40 10 10
MKL 36 22 35 18 / 10 40 10 10
JBR 32 20 31 19 / 10 20 10 10
TUP 40 29 40 23 / 10 80 10 10
&&
.MEG WATCHES/WARNINGS/ADVISORIES...
AR...NONE.
MO...NONE.
MS...NONE.
TN...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS SAN ANGELO TX
137 PM CST Mon Dec 9 2013
.UPDATE...
Quick update to continue patchy freezing fog for portions of the
Big Country this afternoon. Visibilities for the most part have
been improving but Abilene continues to see visibilities between
1/4 and 1/2 miles. Should see visibilities across this area
improve to around 2 miles within the next couple of hours.
Temperatures currently range from the upper 20s and and lower 30s
north of a San Angelo to San Saba line, with upper 30s generally
south of this line. Temperatures should remain nearly steady
through the rest of this afternoon and made adjustments to hourly
temperatures to account for this. No other changes needed at this
time.
&&
.PREV DISCUSSION... /ISSUED 1157 AM CST MON DEC 9 2013/
AVIATION...
/18Z TAFS/
Widespread stratus and FG/FZFG will persist across the terminals
this afternoon. Visibilities are beginning to improve late this
morning but latest guidance indicates IFR/LIFR CIGS persisting for
the remainder of the afternoon hours. The exception will be KSOA
where CIGS should remain mainly MVFR. Not much improvement expected
across the remaining terminals this evening with IFR CIGS continuing
through late evening. KABI will likely hold onto some MVFR
visibilities as well through the evening hours. Drier air filters
into the region overnight with skies clearing across the terminals
after 09Z.
PREV DISCUSSION... /ISSUED 753 AM CST MON DEC 9 2013/
UPDATE...
Expanded the Freezing Fog Advisory another row of counties.
DISCUSSION...
The fog continues to expand into the Concho Valley, so I have
expanded the Freezing Fog Advisory to include Irion, Tom Green,
Concho, Menard, and Schleicher counties. We will continue to monitor
to progress of the fog.
PREV DISCUSSION... /ISSUED 554 AM CST MON DEC 9 2013/
UPDATE...
To expand the Freezing Fog Advisory...
DISCUSSION...
Areas of freezing fog across the Big Country, Heartland and
Northwest Hill country continue to expand to the south and west.
Temperatures are below freezing across the entire area and given
the expansion of the fog, I went ahead and expanded the advisory
to include all of the Big Country and the northern Concho Valley.
The freezing fog could approach areas farther south in the next
few hours, including San Angelo, so I will continue to monitor
trends and these counties may need to eventually be added.
Otherwise, the rest of the forecast looks on track.
Please see the aviation discussion below...
AVIATION...
Stratus/fog continues to expand through much of West Central Texas
this morning resulting in IFR to LIFR conditions. KSOA is a bit
more tricky, as the stratus to the south is struggling to expand
northward. For now, I have indicated MVFR ceilings by 14z, and
will continue to monitor. Some improvement in ceilings is forecast
by late morning or early afternoon, with MVFR ceilings returning
to most sites. Winds today will be from the north at 5 to 10 knots
PREV DISCUSSION... /ISSUED 356 AM CST MON DEC 9 2013/
SHORT TERM...
Today and Tonight
A cold front is currently moving through the Big Country and
should be approaching the Interstate 10 corridor shortly after
sunrise. Winds behind the front will become north and increase to
about 8 to 12 mph, with colder air slowly filtering into West
Central Texas. In addition, areas of freezing fog are evident just
to the east of our area, which has slowly been creeping west. I
expect this freezing fog to expand to a Throckmorton, to Coleman,
to Mason line in the next few hours. A freezing fog advisory is in
effect for parts of the Heartland through 9 AM, and I will
continue to monitor trends for the possibility of expanding it
north into parts of the Big Country and south toward Mason county.
The HRRR is also indicating some post frontal fog across parts of
the Big Country, which will need to be monitored. Stratus should
fill in this morning behind the front, with much of the area
becoming overcast by mid morning. Given the expected cloud cover
and cold air advection, I lowered high temperatures slightly.
Highs will range from the upper 20s north of Interstate 20, to the
mid 40s across the Interstate 10 corridor.
Cloudy skies through much of the overnight period will not
support ideal radiational cooling conditions, but given the cold
airmass that will be filtering into the region, I went ahead and
lowered low temperatures slightly. Tuesday morning low
temperatures will generally be in the teens to lower 20s across
all of West Central Texas.
Daniels
LONG TERM...
Tuesday through Sunday
As a fast moving shortwave trough moves through the Great Lakes
region Tuesday night into Wednesday, a cold front will move into
Texas, causing another brief cooling for Wednesday into Thursday.
However, no precipitation is expected with the front. Lee
troughing on Thursday will allow winds to quickly turn back to the
south in our area, allowing temperatures to warm back up across
the area Thursday and especially Friday. An upper level low
initially off the coast of California on Monday will move across
the Desert Southwest and into the Texas panhandle by Friday. As
this low approaches, weak shortwaves will move across the area out
ahead of it, interacting with moisture return and low level warm
air advection, resulting in at least a slight chance for showers
mainly Thursday afternoon and Thursday night, with some lingering
showers moving out of the area on Friday.
The upper level low will then move east towards the Mississippi
Valley by Saturday, sending a cold front into the area. And while
the cold front will slow the warming trend, the air mass behind
the front will not be of arctic origin, so while we have gone
cooler than the MOS guidance for Saturday and Sunday, temperatures
should continue to trend closer to normal values through the
weekend.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 29 17 40 27 41 / 10 5 0 0 0
San Angelo 33 21 44 26 47 / 10 5 0 0 0
Junction 41 23 47 24 53 / 10 5 0 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
99/99
AREA FORECAST DISCUSSION
NWS SAN ANGELO TX
1157 AM CST MON DEC 9 2013
.AVIATION...
/18Z TAFS/
Widespread stratus and FG/FZFG will persist across the terminals
this afternoon. Visibilities are beginning to improve late this
morning but latest guidance indicates IFR/LIFR CIGS persisting for
the remainder of the afternoon hours. The exception will be KSOA
where CIGS should remain mainly MVFR. Not much improvement expected
across the remaining terminals this evening with IFR CIGS continuing
through late evening. KABI will likely hold onto some MVFR
visibilities as well through the evening hours. Drier air filters
into the region overnight with skies clearing across the terminals
after 09Z.
&&
.PREV DISCUSSION... /ISSUED 753 AM CST MON DEC 9 2013/
UPDATE...
Expanded the Freezing Fog Advisory another row of counties.
DISCUSSION...
The fog continues to expand into the Concho Valley, so I have
expanded the Freezing Fog Advisory to include Irion, Tom Green,
Concho, Menard, and Schleicher counties. We will continue to monitor
to progress of the fog.
PREV DISCUSSION... /ISSUED 554 AM CST MON DEC 9 2013/
UPDATE...
To expand the Freezing Fog Advisory...
DISCUSSION...
Areas of freezing fog across the Big Country, Heartland and
Northwest Hill country continue to expand to the south and west.
Temperatures are below freezing across the entire area and given
the expansion of the fog, I went ahead and expanded the advisory
to include all of the Big Country and the northern Concho Valley.
The freezing fog could approach areas farther south in the next
few hours, including San Angelo, so I will continue to monitor
trends and these counties may need to eventually be added.
Otherwise, the rest of the forecast looks on track.
Please see the aviation discussion below...
AVIATION...
Stratus/fog continues to expand through much of West Central Texas
this morning resulting in IFR to LIFR conditions. KSOA is a bit
more tricky, as the stratus to the south is struggling to expand
northward. For now, I have indicated MVFR ceilings by 14z, and
will continue to monitor. Some improvement in ceilings is forecast
by late morning or early afternoon, with MVFR ceilings returning
to most sites. Winds today will be from the north at 5 to 10 knots
PREV DISCUSSION... /ISSUED 356 AM CST MON DEC 9 2013/
SHORT TERM...
Today and Tonight
A cold front is currently moving through the Big Country and
should be approaching the Interstate 10 corridor shortly after
sunrise. Winds behind the front will become north and increase to
about 8 to 12 mph, with colder air slowly filtering into West
Central Texas. In addition, areas of freezing fog are evident just
to the east of our area, which has slowly been creeping west. I
expect this freezing fog to expand to a Throckmorton, to Coleman,
to Mason line in the next few hours. A freezing fog advisory is in
effect for parts of the Heartland through 9 AM, and I will
continue to monitor trends for the possibility of expanding it
north into parts of the Big Country and south toward Mason county.
The HRRR is also indicating some post frontal fog across parts of
the Big Country, which will need to be monitored. Stratus should
fill in this morning behind the front, with much of the area
becoming overcast by mid morning. Given the expected cloud cover
and cold air advection, I lowered high temperatures slightly.
Highs will range from the upper 20s north of Interstate 20, to the
mid 40s across the Interstate 10 corridor.
Cloudy skies through much of the overnight period will not
support ideal radiational cooling conditions, but given the cold
airmass that will be filtering into the region, I went ahead and
lowered low temperatures slightly. Tuesday morning low
temperatures will generally be in the teens to lower 20s across
all of West Central Texas.
Daniels
LONG TERM...
Tuesday through Sunday
As a fast moving shortwave trough moves through the Great Lakes
region Tuesday night into Wednesday, a cold front will move into
Texas, causing another brief cooling for Wednesday into Thursday.
However, no precipitation is expected with the front. Lee
troughing on Thursday will allow winds to quickly turn back to the
south in our area, allowing temperatures to warm back up across
the area Thursday and especially Friday. An upper level low
initially off the coast of California on Monday will move across
the Desert Southwest and into the Texas panhandle by Friday. As
this low approaches, weak shortwaves will move across the area out
ahead of it, interacting with moisture return and low level warm
air advection, resulting in at least a slight chance for showers
mainly Thursday afternoon and Thursday night, with some lingering
showers moving out of the area on Friday.
The upper level low will then move east towards the Mississippi
Valley by Saturday, sending a cold front into the area. And while
the cold front will slow the warming trend, the air mass behind
the front will not be of arctic origin, so while we have gone
cooler than the MOS guidance for Saturday and Sunday, temperatures
should continue to trend closer to normal values through the
weekend.
20
&&
.PRELIMINARY POINT TEMPS/POPS...
Abilene 26 18 39 27 42 / 10 5 0 0 0
San Angelo 35 19 44 26 46 / 10 5 0 0 0
Junction 46 22 47 24 52 / 10 10 5 0 0
&&
.SJT WATCHES/WARNINGS/ADVISORIES...
FREEZING FOG ADVISORY until Noon CST today FOR THE FOLLOWING
ZONES: Brown...Callahan...Coke...Coleman...Concho...Fisher...
Haskell...Irion...Jones...Kimble...Mason...McCulloch...Menard...
Nolan...Runnels...San Saba...Schleicher...Shackelford...
Sterling...Taylor...Throckmorton...Tom Green.
&&
$$
24
FORECAST DISCUSSION FOR ROUTINE AFTERNOON FORECAST ISSUANCE
.SHORT TERM...TONIGHT AND TUESDAY
ISSUED AT 247 PM CST MON DEC 9 2013
LATEST RUC ANALYSIS AND SATELLITE/RADAR IMAGERY SHOW A BROAD AREA OF
LOW PRESSURE MOVING NORTHEAST OVER NORTHERN ONTARIO AND A SURFACE
RIDGE AXIS SHIFTING EAST OVER THE NORTHERN PLAINS. BETWEEN THE TWO
SYSTEMS...WEST WINDS IS DRIVING ARCTIC AIR ACROSS THE STATE...AND
TEMPERATURES ARE DROPPING ACROSS CENTRAL AND NORTH-CENTRAL
WISCONSIN. NO CHANGE IN THE START OF TIME OF WIND CHILL
HEADLINES...AS THEY ARE ALREADY APPROACHING CRITERIA AT RHINELANDER.
THE LEADING EDGE OF THIS ARCTIC AIR IS MARKED BY A BAND OF STRATO-CU
AND ACCOMPANYING LIGHT SNOW SHOWERS/FLURRIES...WHICH IS NOW ENTERING
NORTHEAST WISCONSIN. ANTICIPATE THE SNOW SHOWERS/FLURRIES TO
DIMINISH LATER THIS AFTERNOON ONCE THE SUN GOES DOWN AND ANY DIURNAL
INSTABILITY IS LOST. ATTENTION THEN TURNS TO A FAST MOVING CLIPPER
SYSTEM WHICH IS DIVING SE OVER SOUTHERN SASKATCHEWAN THIS
AFTERNOON. THE CLIPPER LOOKS DECENT ON SATELLITE IMAGERY AND THERE
ARE PLENTY OF OBS OVER WESTERN NORTH DAKOTA AND EASTERN MONTANA
SHOWING LIGHT TO MODERATE SNOW. SO THE FORECAST CONCERNS START OUT
WITH WIND CHILLS TONIGHT...AND SNOW POTENTIAL WITH THE CLIPPER LATE
TONIGHT INTO TUESDAY MORNING.
TONIGHT...HIGH PRESSURE RIDGE AXIS WILL MOVE EAST INTO CENTRAL
WISCONSIN THIS EVENING AND ACROSS EASTERN WISCONSIN OVERNIGHT.
ALONG WITH THE LOSS OF DAYTIME HEATING...THIS WILL HELP SKIES CLEAR
AND LIGHT SNOW/FLURRIES COME TO AN END LATE IN THE AFTERNOON OR
EARLY THIS EVENING. ARCTIC AIR WILL CONTINUE TO POUR ACROSS THE
REGION DURING THE EVENING...AND THE CLEARING SKIES WILL PROMOTE
TEMPS FALLING QUICKLY WITH LOWS OCCURRING NEAR OR SHORTLY AFTER
MIDNIGHT. THEN ALL EYES WILL BE ON A FAST MOVING CLIPPER PROGGED TO
ENTER THE STATE LATE TONIGHT. THE LATEST MODEL RUNS HAVE TRENDED A
FEW HOURS SLOWER...AND NOW START BRINGING IT INTO THE STATE AFTER
09Z. THE VORT WILL BRING EXCELLENT MID-LEVEL FORCING...SO WILL
INCREASE POPS BY 12Z DESPITE A SEVERE LACK OF MOISTURE. WITH THE
LATER ARRIVAL OF THE CLIPPER...WIND CHILL READINGS WILL REMAIN NEAR
THE 20 BELOW CRITERIA OVER CENTRAL AND NORTH-CENTRAL WISCONSIN
THROUGH THE 12Z HOUR SO NO CHANGE IN HEADLINES ANTICIPATED. TEMPS
WILL REBOUND SOMEWHAT WITH THE INCREASING CLOUDS OVERNIGHT.
TUESDAY...THE CLIPPER WILL QUICKLY ADVANCE EAST ACROSS THE AREA
TUESDAY MORNING. THE STRONG FORCING AND POCKET OF INSTABILITY IN
THE MID-LEVELS SHOULD BRING A FEW TENTHS OF DRY FLUFFY SNOW ACROSS
THE ENTIRE FORECAST AREA BEFORE IT RAPIDLY PULLS OUT BY LATE IN THE
MORNING OR EARLY AFTERNOON. ANOTHER SURGE OF ARCTIC AIR WILL FOLLOW
IN THE WAKE OF THE CLIPPER...WITH STEEPENING LOW LEVEL LAPSE RATES
AND ENHANCED LOW LEVEL RH. WOULDNT BE SURPRISED TO SEE INSTABILITY
SNOW SHOWERS/FLURRIES REDEVELOP IN THE AFTERNOON...SIMILAR TO THE
SNOW SHOWERS ONGOING TODAY. WILL LET THE NEXT SHIFT EVALUATE BEFORE
ADDING THEM TO THE FORECAST. HIGHS FROM THE MIDDLE SINGLE DIGITS
NORTH TO THE MIDDLE TEENS EAST.
.LONG TERM...TUESDAY NIGHT THROUGH MONDAY
ISSUED AT 247 PM CST MON DEC 9 2013
COLD TEMPERATURES/WIND CHILLS AND PCPN CHANCES ARE THE MAIN FCST
CONCERNS.
A REINFORCING SHOT OF ARCTIC AIR WILL BE IN PLACE TUES NGT INTO
WEDS...WITH H8 TEMPS OF -20 TO -25 C OVER THE FORECAST AREA. LOW-
LEVEL WINDS WILL BE WEST-NORTHWEST...SO LAKE EFFECT IMPACT WILL BE
MINIMAL...WITH JUST A FEW SNOW SHOWERS OR FLURRIES EXPECTED OVER
VILAS COUNTY. A S/W TROF AND THE RRQ OF A JET STREAK WILL QUICKLY
SWEEP THROUGH THE SOUTHERN PART OF GRB CWA ON TUES NGT...SO KEPT
CHC POPS OVER C/EC WI. CLOUDS ASSOCIATED WITH THIS SYSTEM AND ANY
LAKE-INDUCED CLOUDS OVER THE FAR NORTH COULD HAVE A BIG IMPACT ON
MIN TEMPS. USED A BLEND OF THE PREV FCST...ECMWF AND A FEW OTHER
TOP PERFORMING GUIDANCE SETS...AND MADE A FEW TWEEKS TO ACCOUNT
FOR CLOUD TRENDS. WILL HAVE COLDEST MIN TEMPS (-15 TO -17 F) IN
THE TOMAHAWK/RHINELANDER/CRANDON REGION...WITH SINGLE DIGITS
BELOW ZERO OVER OUR SOUTHERN/EASTERN COUNTIES...EXCEPT SINGLE
DIGITS ABOVE ZERO ALONG THE LKSHR. HIGH TEMPS ON WEDS WILL BE IN
THE 5 BELOW TO 5 ABOVE RANGE IN MOST AREAS...COLDEST OVER NC WI.
WIND CHILLS LOOK LIKE THEY WILL DROP INTO THE -20 TO -30 RANGE
NORTHWEST OF A LINE FROM ISW-IMT TUES NGT INTO WEDS...AND OVER
MOST OF THE CWA ON WED NGT...SO ADDITIONAL WIND CHILL ADVISORIES
MAY BE NEEDED.
WAA WILL DEVELOP LATE WEDS NGT INTO THURSDAY...AND WILL PROBABLY
GENERATE SOME LIGHT SNOW OR FLURRIES. SOME MODERATION IN TEMPS
IS ANTICIPATED...WITH HIGHS REACHING THE UPPER SINGLE DIGITS
AND TEENS.
THE ARCTIC BAROCLINIC ZONE WILL RESIDE OVER THE REGION THROUGH
MUCH...IF NOT ALL...OF THE EXTENDED FORECAST. TEMPERATURES
WILL REMAIN BLO NORMAL. WITH STRONG WEST-NORTHWEST FLOW ALOFT
IN PLACE DURING THE PERIOD...SEVERAL JET STREAKS/SHORT-WAVE TROFS
WILL PASS THROUGH THE GREAT LAKES REGION. THE RRQ OF A JET STREAK
WILL PASS THROUGH THE REGION THU NGT AND FRI...AND MODELS ARE
HINTING AT AN INVERTED SFC TROF AFFECTING THE REGION FRI NGT/SAT...
AND POSSIBLY LINGERING OVER THE RGN INTO SUNDAY. ANY OF THESE
DISTURBANCES COULD PRODUCE LIGHT SNOW OR FLURRIES...SO ALMOST
EVERY PERIOD OF THE FCST HAS SLGT CHC/CHC POPS. HOPEFULLY IN THE
NEXT FEW DAYS WE WILL BE ABLE TO BETTER DEFINE WHICH OF THESE
SYSTEMS WILL HAVE THE MOST IMPACT ACROSS THE REGION.
&&
.AVIATION...FOR 18Z TAF ISSUANCE
ISSUED AT 1128 AM CST MON DEC 9 2013
LIGHT SNOW AND FLURRIES ARE STUBBORNLY STICKING AROUND
CENTRAL AND NORTH-CENTRAL WISCONSIN AT MIDDAY...AND HAVE TO EXTEND
LOWER VSBYS IN LIGHT SNOW INTO MID-AFTERNOON. WEST WINDS WILL ALSO
REMAIN GUSTY THROUGH THE AFTERNOON BEFORE THE GUSTINESS SUBSIDES BY
EARLY THIS EVENING. A PERIOD OF VFR CONDITIONS WILL THEN FOLLOW
UNTIL LATE TONIGHT...AND THEN A FAST MOVING CLIPPER TYPE SYSTEM WILL
BRING A QUICK ROUND OF SNOW AND LOWERING CIGS LATE TONIGHT INTO
TUESDAY MORNING. VSBYS IN THE SNOW TO AT LEAST FALL INTO THE IFR
RANGE...AND POSSIBLY LOWER BASED ON OBSERVATIONS OVER MONTANA.
&&
.GRB WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY UNTIL 6 AM CST TUESDAY FOR WIZ005-010>013-
018>021-030-031-035>037.
&&
$$
SHORT TERM.....MPC
LONG TERM......KIECKBUSCH
AVIATION.......MPC
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1151 AM CST MON DEC 9 2013
.UPDATE...
ISSUED AT 1044 AM CST MON DEC 9 2013
TEMPERATURES HAVE NOT RISEN ACROSS PORTIONS OF SOUTHEAST MINNESOTA
AND NORTHEAST IOWA THIS MORNING WHILE WINDS HAVE CONTINUED TO
INCREASE TO AROUND 20 TO 30 MPH. THIS HAS LEAD TO WIND CHILLS
DROPPING INTO THE 20 TO 30 DEGREES BELOW ZERO RANGE. WITH
TEMPERATURES NOT EXPECTED TO CLIMB MUCH AT ALL...WILL BE ISSUING A
WIND CHILL ADVISORY FOR PORTIONS OF SE MN/NE IA THROUGH THIS
AFTERNOON. HAVE ALSO ADDED A FEW COUNTIES IN NORTHWEST WISCONSIN
TO THE ADVISORY AND STARTED THE NORTH CENTRAL COUNTIES RIGHT NOW
AS WELL SINCE TEMPERATURES ARE GOING TO CONTINUE TO DROP THERE AS
WELL. EXACT COUNTIES/TIMING IS CURRENTLY BEING WORKED ON WITH
NEIGHBORING OFFICES AND THE ADVISORY SHOULD BE POSTED SHORTLY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 9 2013
MAIN SHORT TERM CONCERNS ARE ON TEMPERATURES...WIND CHILLS AND
POTENTIAL FOR MORE SNOW LATER TONIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A HIGHLY AMPLIFIED RIDGE OVER THE EASTERN PACIFIC...A DEEP
TROUGH FROM CENTRAL CANADA INTO THE FOUR CORNERS...AND RIDGING OVER
THE SOUTHEASTERN U.S.. WITHIN THE DEEP TROUGH THERE WERE 3
SHORTWAVES OF NOTE. THE FIRST WAS OVER SOUTHEAST WISCONSIN WHICH
HELPED BRING THE SNOW TO THE AREA YESTERDAY INTO THE EARLY MORNING
HOURS. MOST OF THE SNOW HAS PUSHED OFF TO THE EAST AS SHOWN BY RADAR
IMAGERY...IN RESPONSE TO SUBSIDENCE AND ISENTROPIC DESCENT IN THE
WAKE OF THE SHORTWAVE. THE SECOND SHORTWAVE OF NOTE WAS OVER THE
DAKOTAS. ALTHOUGH THIS SHORTWAVE WAS ONLY PRODUCING SOME ALTOSTRATUS
AHEAD OF IT...DUE TO DRY AIR SEEN ON THE 00Z BIS SOUNDING...THERE
WAS PLENTY OF COLD AIR WITH IT. 850MB TEMPS ACCORDING TO THE RAP ARE
-25C ACROSS NORTH DAKOTA...OR 2 STANDARD DEVIATIONS BELOW NORMAL.
FINALLY...THE THIRD SHORTWAVE WAS COMING DOWN THE BACK SIDE OF THE
TROUGH THROUGH CENTRAL ALBERTA. IMPRESSIVE 140KT JET AT THE
TROPOPAUSE ACCOMPANYING THE SHORTWAVE. ALREADY SOME LIGHT SNOW
FALLING JUST AHEAD OF THE SHORTWAVE.
A LOT OF RAPID MOTION FORECAST OVER THE NEXT 24 HOURS IN THE UPPER
LEVEL PATTERN...MOSTLY A RESULT FROM THAT STRONG UPPER JET CORE
COMING THROUGH ALBERTA. FIRST OFF...THE SHORTWAVE TROUGH OVER NORTH
DAKOTA IS PROGGED BY MODELS TO SLIDE THROUGH THE FORECAST AREA THIS
AFTERNOON. WE MAY SEE SOME MID OR HIGH CLOUDS PASS THROUGH AHEAD OF
THE SHORTWAVE...BUT THE BULK OF THE CLOUD COVER IS GOING TO BE THE
CURRENT STRATUS AFFECTING THE AREA. ANTICIPATING AS THE SHORTWAVE
PASSES...THE DRY ARCTIC AIR SEEN ACROSS NORTH DAKOTA CURRENTLY WILL
CLEAR OUT THE STRATUS. THIS MAY HAPPEN PRETTY QUICK WITH CLEARING
ALREADY COMING INTO THE FORECAST AREA. IN ADDITION...THAT SAME
ARCTIC AIR IS EXPECTED TO CAUSE TEMPERATURES TO FALL AS 850MB TEMPS
PLUMMET FROM THE CURRENT -14 TO -18C READINGS TO -18 TO -22C BY 21Z.
WINDS LOOK TO CRANK UP TOO AS THAT SHORTWAVE AND ASSOCIATED COLD AIR
COME IN. THESE WINDS...WITH GUSTS UPWARDS OF 20 TO 30 MPH...ARE
LIKELY TO CAUSE SOME BLOWING AND DRIFTING OF THE RECENT SNOW. AS
TEMPERATURES FALL THIS AFTERNOON...WIND CHILLS WILL BECOME MORE OF
AN ISSUE. TAYLOR/CLARK COUNTIES LOOK TO DROP INTO ADVISORY RANGE
AROUND 22Z AND DO NOT GET OUT UNTIL 12Z TUESDAY...THUS HAVE GONE
AHEAD AND ISSUED AN ADVISORY FOR THEM.
THE COLD AIR TONIGHT DOES NOT LAST LONG. MODELS ARE IN GOOD
AGREEMENT SHOWING THE ALBERTA SHORTWAVE DIGGING INTO THE DAKOTAS
THIS EVENING...THEN MOVING INTO THE FORECAST AREA TOWARDS 12Z. AS
THIS SHORTWAVE APPROACHES...WARM ADVECTION ENSUES...WITH 850MB TEMPS
CLIMBING UP TO -13 TO -17C BY 09Z. ALL INDICATIONS ARE THAT THE
ISENTROPIC LIFT AND SOME MOISTURE ADVECTION WILL CAUSE A MID CLOUD
DECK TO SPREAD ACROSS THE FORECAST AREA. THESE CLOUDS AND THE WARM
ADVECTION SHOULD RESULT IN RISING TEMPS LATE THIS EVENING INTO THE
OVERNIGHT...HELPING TO BRING WIND CHILLS UP. ADDITIONALLY...THE BEST
JUXTAPOSITION OF LOW LEVEL SATURATION AND ISENTROPIC LIFT OCCURS
NORTH OF INTERSTATE 90. GIVEN THE ARCTIC AIRMASS IN PLACE PRIOR TO
THE SHORTWAVE ARRIVAL...LIKELY WILL NOT TAKE MUCH TO SNOW. QPF MAY
NOT AMOUNT TO MUCH WITH THE COLD AIRMASS...MAYBE A COUPLE HUNDREDTHS
TOPS...BUT ENOUGH FORCING TO WARRANT HIGH PRECIPITATION CHANCES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 9 2013
MAIN LONG TERM FORECAST CONCERNS ARE ON TEMPERATURES...AS WELL AS
THE OSCILLATING DIURNAL TRENDS WITH THEM...AND POTENTIAL FOR
PRECIPITATION THROUGHOUT.
SHORTWAVE TROUGH COMING INTO THE FORECAST AREA TONIGHT QUICKLY MOVES
THROUGH DURING THE TUESDAY MORNING HOURS. ANY SNOW LOOKS TO DEPART
OFF TO THE EAST PRETTY FAST IN THE MORNING...FOLLOWED BY CLEARING
AND BRISK WEST WINDS. THESE WINDS COULD RESULT IN MORE BLOWING
SNOW...ESPECIALLY IF WE CAN GET A FEW TENTHS OUT OF TONIGHT.
ADDITIONALLY...THE WINDS DRIVE IN A BRIEF SURGE OF ARCTIC AIR WITH
850MB TEMPS FALLING TO -16 TO -20C BY 18Z. 09.00Z
ECMWF/NAM/CANADIAN/GFS THEN ALL DEPICT YET ANOTHER SHORTWAVE TROUGH
DROPPING INTO THE DAKOTAS TUESDAY NIGHT. AHEAD OF THIS
FEATURE...INCREASING ISENTROPIC LIFT AND MID LEVEL FRONTOGENESIS
LOOKS TO DEVELOP A BAND OF SNOW. POSITION OF THIS BAND OF SNOW IS
PROBLEMATIC...WITH THE ECMWF/NAM FARTHER NORTH COMPARED TO THE
GFS/CANADIAN. CONSENSUS WOULD SUGGEST LOCATIONS SOUTH OF I-90 WOULD
STAND TO SEE THE BEST CHANCE OF SEEING SNOW...SO RAISED CHANCES
TOWARDS 60 IN THIS AREA. THE BAND DOES APPEAR TO BE QUICK MOVING...
SUCH THAT BY 12Z WEDNESDAY...ITS ALREADY SOUTHEAST OF THE AREA.
NONETHELESS...WITH SNOW TO WATER RATIOS APPROACH 20 TO 1...WE COULD
SQUEEZE OUT AN INCH OR SO OUT OF THIS BAND.
JUST LIKE IN THE WAKE OF THE EVERY SHORTWAVE TROUGH...ANOTHER SURGE
OF ARCTIC AIR IS PROGGED TO FLOW INTO THE AREA ON WEDNESDAY WHEN THE
TROUGH MOVES THROUGH. 850MB TEMPS DROP TO -20 TO -24C AT 18Z
WEDNESDAY. THUS...DESPITE THAT SKIES SHOULD CLEAR ON WEDNESDAY AS
THE TROUGH COMES IN...IT WILL BE TOUGH TO WARM UP MUCH. MOST
LOCATIONS ARE LIKELY TO NOT GET OUT OF THE SINGLE DIGITS ABOVE
ZERO...AND NORTH OF HIGHWAY 10 MAY NOT EVEN GET TO ZERO. WITH THE
COLD TEMPS AND A NORTHWEST BREEZE...WIND CHILLS ARE YET AGAIN A
FACTOR WITH ANOTHER ADVISORY LIKELY NEEDED. NORTH OF HIGHWAY 10
APPEARS TO BE THE MOST LIKELY AREA FOR AN ADVISORY...STARTING LATE
TUESDAY NIGHT AND RUNNING THROUGH WEDNESDAY NIGHT. WEDNESDAY NIGHT
IS INTERESTING TOO. ALL MODELS ARE SUGGESTING RISING 500MB HEIGHTS
ACROSS THE CENTRAL PART OF THE COUNTRY. WARM ADVECTION ASSOCIATED
WITH THESE RISING HEIGHTS SHOULD CAUSE TEMPERATURES TO RISE...AFTER
A RAPID DROP OFF IN THE EVENING ASSOCIATED WITH A SURFACE RIDGE
PASSAGE. THERE MAY EVEN BE SOME SNOW THAT TRIES TO GET GOING NORTH
OF I-94...AS SUGGESTED BY THE ECMWF/CANADIAN AND HAVE INCLUDED 20
PERCENT CHANCES FOR THIS. THESE CHANCES PERSIST INTO THURSDAY. MUCH
WARMER 850MB TEMPS ON THURSDAY...ON THE ORDER OF -2 TO -8C BY
00Z...WILL RESULT IN HIGHS 15-20 DEGREES WARMER COMPARED TO
WEDNESDAY.
FROM THURSDAY NIGHT THROUGH SUNDAY...09.00Z ECMWF/GFS/CANADIAN
SUGGEST A NORTHWEST FLOW PATTERN IN THE MEAN...STRETCHING FROM
BRITISH COLUMBIA INTO THE GREAT LAKES. AT THE MOMENT THURSDAY NIGHT
LOOKS DRY. AS WE HEAD INTO FRIDAY AND ESPECIALLY FRIDAY
NIGHT...THERE ARE SUGGESTIONS A SOUTHERN STREAM SHORTWAVE TROUGH
COMING OUT OF THE CENTRAL PLAINS AND HEADING INTO THE OHIO VALLEY
COULD SPREAD SOME LIGHT SNOW INTO THE FORECAST AREA. THE CANADIAN IS
THE FARTHEST NORTHWEST AND DID HONOR THE SOLUTION WITH A 20 PERCENT
CHANCE. HOWEVER...THE 09.00Z GFS/ECMWF SUGGEST IT COULD STAY TO THE
SOUTHEAST...THUS SOMETHING TO MONITOR. HEADING INTO THE WEEKEND...
THE ECMWF/GFS SUGGEST A POTENT UPPER TROUGH WILL BE DROPPING SOUTH
INTO MANITOBA AND ONTARIO. THE ECMWF IS VERY AGGRESSIVE DIGGING IT
INTO WISCONSIN ON SUNDAY. FOR NOW STAYED WITH THE CONSENSUS WHICH
YIELDS A GENERALLY DRY SOLUTION WITH TEMPERATURES HOVERING SLIGHTLY
BELOW NORMAL. HOWEVER...SHOULD THE 00Z ECMWF BE CORRECT...
TEMPERATURES MAY NEED SIGNIFICANT LOWERING FOR SUNDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z TUESDAY AFTERNOON)
ISSUED AT 1151 AM CST MON DEC 9 2013
THE COMBINATION OF GUSTY WINDS AND A FRESH SNOW PACK HAS RESULTED
IN SOME BLOWING SNOW IN SOUTHEAST MINNESOTA. THIS HAS CAUSED
VISIBILITIES TO DROP AT RST TO 2-3SM THIS MORNING AND THAT WILL
LIKELY CONTINUE INTO THE AFTERNOON BEFORE WINDS DROP OFF AROUND
SUNSET. SOME SCT-BKN MVFR CEILINGS HAVE BEEN OCCURRING ACROSS
WESTERN WISCONSIN AS TIMES AS WELL WITH LSE SEEMING TO BE ON THE
WESTERN EDGE OF IT.
WINDS WILL START TO COME AROUND TO THE SOUTHWEST THIS EVENING AS
THE NEXT SYSTEM APPROACHES FROM THE WEST. CEILINGS AND VISIBILITY
WILL DROP TO MVFR/IFR AS THE NEXT SNOW BAND COMES IN OVERNIGHT.
THE BEST TIMING FOR THIS SNOW APPEARS TO BE AROUND 9Z AT RST AND
11Z AT LSE AND SHOULD ONLY LAST FOR 2-4 HOURS AS THIS SYSTEM
QUICKLY MOVES THROUGH. WINDS WILL SHIFT BACK AROUND TO THE WEST
NORTHWEST AND BECOME GUSTY AGAIN AT 20-30KTS. THIS WILL LIKELY
LEAD TO SOME MORE BLOWING SNOW AND VISIBILITY REDUCTIONS AT RST
TOMORROW MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR WIZ032>034.
WIND CHILL ADVISORY UNTIL 6 AM CST TUESDAY FOR WIZ017-029.
MN...WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR MNZ079-
086>088-094-095.
IA...WIND CHILL ADVISORY UNTIL 6 PM CST THIS EVENING FOR IAZ008-009-
018-019.
&&
$$
UPDATE...HALBACH
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...HALBACH
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1044 AM CST MON DEC 9 2013
.UPDATE...
ISSUED AT 1044 AM CST MON DEC 9 2013
TEMPERATURES HAVE NOT RISEN ACROSS PORTIONS OF SOUTHEAST MINNESOTA
AND NORTHEAST IOWA THIS MORNING WHILE WINDS HAVE CONTINUED TO
INCREASE TO AROUND 20 TO 30 MPH. THIS HAS LEAD TO WIND CHILLS
DROPPING INTO THE 20 TO 30 DEGREES BELOW ZERO RANGE. WITH
TEMPERATURES NOT EXPECTED TO CLIMB MUCH AT ALL...WILL BE ISSUING A
WIND CHILL ADVISORY FOR PORTIONS OF SE MN/NE IA THROUGH THIS
AFTERNOON. HAVE ALSO ADDED A FEW COUNTIES IN NORTHWEST WISCONSIN
TO THE ADVISORY AND STARTED THE NORTH CENTRAL COUNTIES RIGHT NOW
AS WELL SINCE TEMPERATURES ARE GOING TO CONTINUE TO DROP THERE AS
WELL. EXACT COUNTIES/TIMING IS CURRENTLY BEING WORKED ON WITH
NEIGHBORING OFFICES AND THE ADVISORY SHOULD BE POSTED SHORTLY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 352 AM CST MON DEC 9 2013
MAIN SHORT TERM CONCERNS ARE ON TEMPERATURES...WIND CHILLS AND
POTENTIAL FOR MORE SNOW LATER TONIGHT.
CURRENTLY AS OF 08Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED A HIGHLY AMPLIFIED RIDGE OVER THE EASTERN PACIFIC...A DEEP
TROUGH FROM CENTRAL CANADA INTO THE FOUR CORNERS...AND RIDGING OVER
THE SOUTHEASTERN U.S.. WITHIN THE DEEP TROUGH THERE WERE 3
SHORTWAVES OF NOTE. THE FIRST WAS OVER SOUTHEAST WISCONSIN WHICH
HELPED BRING THE SNOW TO THE AREA YESTERDAY INTO THE EARLY MORNING
HOURS. MOST OF THE SNOW HAS PUSHED OFF TO THE EAST AS SHOWN BY RADAR
IMAGERY...IN RESPONSE TO SUBSIDENCE AND ISENTROPIC DESCENT IN THE
WAKE OF THE SHORTWAVE. THE SECOND SHORTWAVE OF NOTE WAS OVER THE
DAKOTAS. ALTHOUGH THIS SHORTWAVE WAS ONLY PRODUCING SOME ALTOSTRATUS
AHEAD OF IT...DUE TO DRY AIR SEEN ON THE 00Z BIS SOUNDING...THERE
WAS PLENTY OF COLD AIR WITH IT. 850MB TEMPS ACCORDING TO THE RAP ARE
-25C ACROSS NORTH DAKOTA...OR 2 STANDARD DEVIATIONS BELOW NORMAL.
FINALLY...THE THIRD SHORTWAVE WAS COMING DOWN THE BACK SIDE OF THE
TROUGH THROUGH CENTRAL ALBERTA. IMPRESSIVE 140KT JET AT THE
TROPOPAUSE ACCOMPANYING THE SHORTWAVE. ALREADY SOME LIGHT SNOW
FALLING JUST AHEAD OF THE SHORTWAVE.
A LOT OF RAPID MOTION FORECAST OVER THE NEXT 24 HOURS IN THE UPPER
LEVEL PATTERN...MOSTLY A RESULT FROM THAT STRONG UPPER JET CORE
COMING THROUGH ALBERTA. FIRST OFF...THE SHORTWAVE TROUGH OVER NORTH
DAKOTA IS PROGGED BY MODELS TO SLIDE THROUGH THE FORECAST AREA THIS
AFTERNOON. WE MAY SEE SOME MID OR HIGH CLOUDS PASS THROUGH AHEAD OF
THE SHORTWAVE...BUT THE BULK OF THE CLOUD COVER IS GOING TO BE THE
CURRENT STRATUS AFFECTING THE AREA. ANTICIPATING AS THE SHORTWAVE
PASSES...THE DRY ARCTIC AIR SEEN ACROSS NORTH DAKOTA CURRENTLY WILL
CLEAR OUT THE STRATUS. THIS MAY HAPPEN PRETTY QUICK WITH CLEARING
ALREADY COMING INTO THE FORECAST AREA. IN ADDITION...THAT SAME
ARCTIC AIR IS EXPECTED TO CAUSE TEMPERATURES TO FALL AS 850MB TEMPS
PLUMMET FROM THE CURRENT -14 TO -18C READINGS TO -18 TO -22C BY 21Z.
WINDS LOOK TO CRANK UP TOO AS THAT SHORTWAVE AND ASSOCIATED COLD AIR
COME IN. THESE WINDS...WITH GUSTS UPWARDS OF 20 TO 30 MPH...ARE
LIKELY TO CAUSE SOME BLOWING AND DRIFTING OF THE RECENT SNOW. AS
TEMPERATURES FALL THIS AFTERNOON...WIND CHILLS WILL BECOME MORE OF
AN ISSUE. TAYLOR/CLARK COUNTIES LOOK TO DROP INTO ADVISORY RANGE
AROUND 22Z AND DO NOT GET OUT UNTIL 12Z TUESDAY...THUS HAVE GONE
AHEAD AND ISSUED AN ADVISORY FOR THEM.
THE COLD AIR TONIGHT DOES NOT LAST LONG. MODELS ARE IN GOOD
AGREEMENT SHOWING THE ALBERTA SHORTWAVE DIGGING INTO THE DAKOTAS
THIS EVENING...THEN MOVING INTO THE FORECAST AREA TOWARDS 12Z. AS
THIS SHORTWAVE APPROACHES...WARM ADVECTION ENSUES...WITH 850MB TEMPS
CLIMBING UP TO -13 TO -17C BY 09Z. ALL INDICATIONS ARE THAT THE
ISENTROPIC LIFT AND SOME MOISTURE ADVECTION WILL CAUSE A MID CLOUD
DECK TO SPREAD ACROSS THE FORECAST AREA. THESE CLOUDS AND THE WARM
ADVECTION SHOULD RESULT IN RISING TEMPS LATE THIS EVENING INTO THE
OVERNIGHT...HELPING TO BRING WIND CHILLS UP. ADDITIONALLY...THE BEST
JUXTAPOSITION OF LOW LEVEL SATURATION AND ISENTROPIC LIFT OCCURS
NORTH OF INTERSTATE 90. GIVEN THE ARCTIC AIRMASS IN PLACE PRIOR TO
THE SHORTWAVE ARRIVAL...LIKELY WILL NOT TAKE MUCH TO SNOW. QPF MAY
NOT AMOUNT TO MUCH WITH THE COLD AIRMASS...MAYBE A COUPLE HUNDREDTHS
TOPS...BUT ENOUGH FORCING TO WARRANT HIGH PRECIPITATION CHANCES.
.LONG TERM...(TUESDAY THROUGH SUNDAY)
ISSUED AT 352 AM CST MON DEC 9 2013
MAIN LONG TERM FORECAST CONCERNS ARE ON TEMPERATURES...AS WELL AS
THE OSCILLATING DIURNAL TRENDS WITH THEM...AND POTENTIAL FOR
PRECIPITATION THROUGHOUT.
SHORTWAVE TROUGH COMING INTO THE FORECAST AREA TONIGHT QUICKLY MOVES
THROUGH DURING THE TUESDAY MORNING HOURS. ANY SNOW LOOKS TO DEPART
OFF TO THE EAST PRETTY FAST IN THE MORNING...FOLLOWED BY CLEARING
AND BRISK WEST WINDS. THESE WINDS COULD RESULT IN MORE BLOWING
SNOW...ESPECIALLY IF WE CAN GET A FEW TENTHS OUT OF TONIGHT.
ADDITIONALLY...THE WINDS DRIVE IN A BRIEF SURGE OF ARCTIC AIR WITH
850MB TEMPS FALLING TO -16 TO -20C BY 18Z. 09.00Z
ECMWF/NAM/CANADIAN/GFS THEN ALL DEPICT YET ANOTHER SHORTWAVE TROUGH
DROPPING INTO THE DAKOTAS TUESDAY NIGHT. AHEAD OF THIS
FEATURE...INCREASING ISENTROPIC LIFT AND MID LEVEL FRONTOGENESIS
LOOKS TO DEVELOP A BAND OF SNOW. POSITION OF THIS BAND OF SNOW IS
PROBLEMATIC...WITH THE ECMWF/NAM FARTHER NORTH COMPARED TO THE
GFS/CANADIAN. CONSENSUS WOULD SUGGEST LOCATIONS SOUTH OF I-90 WOULD
STAND TO SEE THE BEST CHANCE OF SEEING SNOW...SO RAISED CHANCES
TOWARDS 60 IN THIS AREA. THE BAND DOES APPEAR TO BE QUICK MOVING...
SUCH THAT BY 12Z WEDNESDAY...ITS ALREADY SOUTHEAST OF THE AREA.
NONETHELESS...WITH SNOW TO WATER RATIOS APPROACH 20 TO 1...WE COULD
SQUEEZE OUT AN INCH OR SO OUT OF THIS BAND.
JUST LIKE IN THE WAKE OF THE EVERY SHORTWAVE TROUGH...ANOTHER SURGE
OF ARCTIC AIR IS PROGGED TO FLOW INTO THE AREA ON WEDNESDAY WHEN THE
TROUGH MOVES THROUGH. 850MB TEMPS DROP TO -20 TO -24C AT 18Z
WEDNESDAY. THUS...DESPITE THAT SKIES SHOULD CLEAR ON WEDNESDAY AS
THE TROUGH COMES IN...IT WILL BE TOUGH TO WARM UP MUCH. MOST
LOCATIONS ARE LIKELY TO NOT GET OUT OF THE SINGLE DIGITS ABOVE
ZERO...AND NORTH OF HIGHWAY 10 MAY NOT EVEN GET TO ZERO. WITH THE
COLD TEMPS AND A NORTHWEST BREEZE...WIND CHILLS ARE YET AGAIN A
FACTOR WITH ANOTHER ADVISORY LIKELY NEEDED. NORTH OF HIGHWAY 10
APPEARS TO BE THE MOST LIKELY AREA FOR AN ADVISORY...STARTING LATE
TUESDAY NIGHT AND RUNNING THROUGH WEDNESDAY NIGHT. WEDNESDAY NIGHT
IS INTERESTING TOO. ALL MODELS ARE SUGGESTING RISING 500MB HEIGHTS
ACROSS THE CENTRAL PART OF THE COUNTRY. WARM ADVECTION ASSOCIATED
WITH THESE RISING HEIGHTS SHOULD CAUSE TEMPERATURES TO RISE...AFTER
A RAPID DROP OFF IN THE EVENING ASSOCIATED WITH A SURFACE RIDGE
PASSAGE. THERE MAY EVEN BE SOME SNOW THAT TRIES TO GET GOING NORTH
OF I-94...AS SUGGESTED BY THE ECMWF/CANADIAN AND HAVE INCLUDED 20
PERCENT CHANCES FOR THIS. THESE CHANCES PERSIST INTO THURSDAY. MUCH
WARMER 850MB TEMPS ON THURSDAY...ON THE ORDER OF -2 TO -8C BY
00Z...WILL RESULT IN HIGHS 15-20 DEGREES WARMER COMPARED TO
WEDNESDAY.
FROM THURSDAY NIGHT THROUGH SUNDAY...09.00Z ECMWF/GFS/CANADIAN
SUGGEST A NORTHWEST FLOW PATTERN IN THE MEAN...STRETCHING FROM
BRITISH COLUMBIA INTO THE GREAT LAKES. AT THE MOMENT THURSDAY NIGHT
LOOKS DRY. AS WE HEAD INTO FRIDAY AND ESPECIALLY FRIDAY
NIGHT...THERE ARE SUGGESTIONS A SOUTHERN STREAM SHORTWAVE TROUGH
COMING OUT OF THE CENTRAL PLAINS AND HEADING INTO THE OHIO VALLEY
COULD SPREAD SOME LIGHT SNOW INTO THE FORECAST AREA. THE CANADIAN IS
THE FARTHEST NORTHWEST AND DID HONOR THE SOLUTION WITH A 20 PERCENT
CHANCE. HOWEVER...THE 09.00Z GFS/ECMWF SUGGEST IT COULD STAY TO THE
SOUTHEAST...THUS SOMETHING TO MONITOR. HEADING INTO THE WEEKEND...
THE ECMWF/GFS SUGGEST A POTENT UPPER TROUGH WILL BE DROPPING SOUTH
INTO MANITOBA AND ONTARIO. THE ECMWF IS VERY AGGRESSIVE DIGGING IT
INTO WISCONSIN ON SUNDAY. FOR NOW STAYED WITH THE CONSENSUS WHICH
YIELDS A GENERALLY DRY SOLUTION WITH TEMPERATURES HOVERING SLIGHTLY
BELOW NORMAL. HOWEVER...SHOULD THE 00Z ECMWF BE CORRECT...
TEMPERATURES MAY NEED SIGNIFICANT LOWERING FOR SUNDAY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z TUESDAY MORNING)
ISSUED AT 542 AM CST MON DEC 9 2013
VFR TO MVFR CONDITIONS ARE EXPECTED AT THE TAF SITES TODAY. GUSTY
WEST WINDS OF 14 TO 18 KTS WITH GUSTS AROUND 24KTS WILL LEAD TO
SOME PATCHY BLOWING SNOW...POSSIBLY REDUCING VISIBILITIES TO
AROUND 5SM AT TIMES. SOUTH/SOUTHWEST WINDS WILL INCREASE LATE
TONIGHT AHEAD OF A WEAK SYSTEM APPROACHING FROM THE NORTHERN
PLAINS. LOOK FOR WINDS TO INCREASE INTO THE 14 TO 18 KT RANGE
AGAIN WITH GUSTS AROUND 25 KTS POSSIBLE. SOME PATCHY BLOWING SNOW
MAY OCCUR AGAIN LATE TONIGHT AS THE WINDS INCREASE. LIGHT SNOW OR
FLURRIES WILL MOVE ACROSS THE TAF SITES MAINLY AFTER 10Z TONIGHT.
A BRIEF PERIOD OF MVFR OR POSSIBLY IFR CONDITIONS MAY OCCUR AS THE
SNOW MOVES THROUGH.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...WIND CHILL ADVISORY FROM 4 PM THIS AFTERNOON TO 6 AM CST TUESDAY
FOR WIZ017-029.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...HALBACH
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP