Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/02/14
AREA FORECAST DISCUSSION
NWS RENO NV
123 PM PST TUE DEC 31 2013
.SYNOPSIS...
HIGH PRESSURE WILL MAINTAIN LIGHT WINDS AND VALLEY INVERSIONS
OVER THE REGION THROUGH THURSDAY WITH REDUCED AIR QUALITY. PERIODS
OF HIGH CLOUDS WILL STREAM OVERHEAD. A STORM PASSING TO THE NORTH
MAY HELP ERODE THE INVERSIONS FRIDAY. THE WEATHER PATTERN OVER THE
WEST MAY CHANGE NEXT WEEK BUT THERE ARE STILL NO SIGNIFICANT
STORMS ON THE HORIZON.
&&
.SHORT TERM...
WELL THE METEOROLOGICAL EXCITEMENT OF WINTER 2013-14 JUST KEEPS
ON GOING - SAID NO ONE AT NWS RENO. HIGH PRESSURE WILL BUILD BACK
INTO THE REGION THROUGH THURSDAY. THIS ALONG WITH LIGHT WINDS WILL
MAINTAIN INVERSIONS IN THE LOWER VALLEYS, PER NAM FORECAST
SOUNDINGS. WE MAY SEE SOME MIXING BUT ONLY TO 500-1000 FT AGL,
WHICH WILL PROMOTE REDUCED AIR QUALITY. SLIGHTLY HIGHER LOW LEVEL
RH AND CLEAR SKIES MAY HELP FZFG REDEVELOP AROUND FALLON/TRUCKEE
LATE TONIGHT. HRRR GUIDANCE DOES DEVELOP FOG NEAR NFL AFTER
MIDNIGHT BUT IT`S QUITE LOCALIZED IN THE WETLANDS AREA NE OF TOWN.
QUICK MOVING TROF FORECAST TO DROP INTO THE EASTERN GREAT BASIN
FRIDAY. WHILE ENSEMBLE SPREADS ARE ABOVE NORMAL FOR THIS SYSTEM,
THERE`S BEEN AN EASTWARD TREND IN THE TROF TRAJECTORY. THEREFORE
WE`VE REMOVED POPS FOR FRI-FRI NIGHT. THIS SYSTEM MAY BRING ENOUGH
WIND AND COOLING ALOFT TO YIELD BETTER MIXING FRIDAY AND CLEAR OUT
INVERSIONS IN ALL BUT THE LOWEST VALLEYS. CONFIDENCE IN THIS IS
ADMITTEDLY ONLY MEDIUM BASED ON UNCERTAINTIES IN THE TROF PATH AND
HOW INCREASED THE WINDS/MIXING WILL END UP BEING. SHOULD MIXING BE
BETTER THAN EXPECTED - HIGHS FRIDAY MAY BE A GOOD 5-7 DEGREES
WARMER THAN CURRENTLY FORECAST. CS
.LONG TERM...SATURDAY THROUGH TUESDAY...
TROUGH WILL BE EXITING TO THE EAST OVER THE WEEKEND WITH A LIGHT
NORTHEAST FLOW COOLING TEMPERATURES DOWN A BIT AS SURFACE HIGH
BUILDS ACROSS THE GREAT BASIN. WARMING ALOFT WILL HELP ESTABLISH
INVERSIONS AGAIN, AND AFTER A POSSIBLE BREAK FRIDAY, MIXING AND
TRANSPORT WILL BECOME POOR, ESPECIALLY SUN-MON. MODELS ARE
BEGINNING TO CONVERGE ON A WEAK SYSTEM UNDERCUTTING THE EAST
PACIFIC RIDGE AND POSSIBLY BRINGING SOME LIGHT PRECIPITATION TO
THE REGION BY TUE. DID NOT INCREASE POPS BUT DID SPREAD THE SLIGHT
CHANCES FURTHER EAST AND SOUTH. MODEL RUNS OVER THE WEST PACIFIC
INDICATE UPPER JET PUSHING FURTHER EASTWARD INTO THE CENTRAL
PACIFIC BY THE SECOND WEEK OF JANUARY. GEFS/GEFSBC FORECAST A
MODERATE MJO IN THE WEST PACIFIC BY JAN 14TH SUPPORTING THIS
EASTWARD EXPANSION. UNFORTUNATELY, AT LEAST FOR THE INTERIM, THIS
WOULD ONLY ACT TO PUMP THE RIDGE BACK UP NEAR THE WEST COAST OR
JUST OFFSHORE. NO MAJOR SYSTEMS ARE ON THE HORIZON JUST YET. WE
WAIT. HOHMANN
&&
.AVIATION...
SKIES WILL BE CLEAR OVERNIGHT WITH SOME PATCHY FREEZING FOG
AROUND KNFL AND ALSO IN THE MARTIS AND SIERRA VALLEYS LATE TONIGHT
AND NEW YEARS DAY MORNING. HAZY CONDITIONS IN THE RENO-SPARKS-
CARSON CITY AREA BUT OTHERWISE VFR. LIGHT WINDS. HOHMANN
&&
.REV WATCHES/WARNINGS/ADVISORIES...
NV...NONE.
CA...NONE.
&&
$$
FOR MORE INFORMATION FROM THE NATIONAL WEATHER SERVICE VISIT...
HTTP://WEATHER.GOV/RENO (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1027 AM MST TUE DEC 31 2013
.UPDATE...
ISSUED AT 940 AM MST TUE DEC 31 2013
UPDATED GRIDS/ZONES TO INCREASE POPS A BIT OVER LAKE COUNTY...WHERE
PERSISTENT SHSN CONTINUE...AND ADJUST AREAL SKY COVERAGE. ROSE
UPDATE ISSUED AT 746 AM MST TUE DEC 31 2013
BASED ON LATEST OBS EXTENDED THE LIFR FOG IN KALS UNTIL 16Z. VIS
SHOULD IMPROVE AFTER 16Z WITH LIFR CIGS BREAKING BY 17Z. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM MST TUE DEC 31 2013
NEXT SHORTWAVE WILL BE RIDING THROUGH NORTHWEST FLOW ALOFT INTO
NORTHWEST COLORADO LATE TONIGHT. AHEAD OF THIS SYSTEM TODAY SHOULD
BE A WARM DAY WITH TEMPERATURES CLIMBING INTO THE 50S. ALREADY
STARTING TO SEE SOME WAVE CLOUDINESS AND THESE WILL CONTINUE TO
THICKEN AND SPREAD EASTWARD AS MORE MOISTURE EVIDENT IN WV PICS
CONTINUES TO STREAM IN FROM THE NORTHWEST THIS MORNING. THIS WILL
SERVE TO CUT BACK ON MAX TEMPS A BIT THIS AFTERNOON IN SOME
PLACES...ESPECIALLY ALONG THE ARKANSAS RIVER VALLEY WHERE WINDS MAY
HAVE A HARDER TIME MIXING DOWN. HRRR DEPICTS THIS IN SFC T FIELDS
NICELY. OTHER AREA WHERE TEMPS WILL REALLY STRUGGLE WILL BE ACROSS
THE SAN LUIS VALLEY WHERE SNOW COVER HAS ALREADY DROPPED MAX TEMPS
DOWN TO AROUND 10 BELOW ZERO THIS MORNING. DEPENDING ON HOW QUICKLY
AND THICKLY HIGH CLOUDS SPREAD IN LATER THIS MORNING...TEMPERATURES
MAY STRUGGLE TO GET INTO THE MID/UPPER TEENS. HAVE CUT BACK ON MAX
TEMPS THERE CONSIDERABLY OVER GUIDANCE. MEANWHILE FOG IN THE SAN
LUIS VALLEY SHOULD THIN SOME AS HIGH CLOUDINESS MOVES IN THROUGH THE
MORNING...THEN DISSIPATE ENTIRELY BY 16Z. MEANWHILE...CENTRAL
MOUNTAINS WILL SEE OROGRAPHIC SNOW SHOWERS SPREAD IN DURING THE
MORNING...THEN DECREASE A BIT TOWARDS AFTERNOON. ANY ACCUMULATIONS LOOK
LIGHT AT THIS POINT...AND CONFINED MOSTLY TO THE HIGHER ELEVATIONS
OF THE SAWATCH AND MOSQUITO RANGES.
TONIGHT...SNOW SHOULD START TO RAMP UP ALONG THE CONTINENTAL DIVIDE
TOWARDS 06Z...WITH A FEW SNOW SHOWERS POSSIBLY SPREADING INTO THE
HIGHER PEAKS OF THE SANGRES TOWARDS 12Z. HEAVIEST ACCUMULATIONS
WILL STAY CONFINED TO THE CENTRAL MOUNTAINS WHERE ANOTHER 1 TO 3
INCHES WILL BE POSSIBLE OVERNIGHT. WESTERLY WINDS INTO THE LEE SIDE
SFC LOW WILL KEEP MIN TEMPS WARM ALONG THE LOWER EASTERN SLOPES OF
THE SE MTS. A COLD FRONT WILL DROP THROUGH THE SOUTHEAST PLAINS
AFTER 09Z BRINGING AN INCREASE IN NORTH WINDS TOWARDS DAWN. GFS AND
ECMWF APPEAR TO HAVE TRENDED TOWARDS A MORE AMPLIFIED SOLN WITH THE
UPPER TROF AS IT MOVES ACROSS SE CO TOWARDS MORNING...BUT FOR NOW
THINK ANY LIGHT PRECIP WILL HOLD OFF UNTIL AFTER 12Z. -KT
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 516 AM MST TUE DEC 31 2013
NOT MANY METEOROLOGICAL ADJUSTMENTS NEEDED DURING THE LONGER TERM
WITH PRIMARY CONCERNS CONTINUING TO BE POPS...GUSTY WINDS AT TIMES
AND TEMPERATURES.
RECENT LONGER TERM COMPUTER SIMULATIONS INDICATES THAT A COUPLE
OF UPPER DISTURBANCES WILL CROSS THE FORECAST DISTRICT DURING THE
LONGER TERM WITH THE INITIAL SYSTEM IMPACTING THE CWFA NEW YEARS
DAYS AND ANOTHER SYSTEM IMPACTING SOUTHERN COLORADO DURING THE
WEEKEND.
THEN GENERALLY DRY AND MILD TO WARM CONDITIONS SHOULD DEVELOP
OVER THE FORECAST DISTRICT FROM THURSDAY INTO FRIDAY AS DRY
NORTHWESTERLY UPPER FLOW IMPACTS SOUTHERN COLORADO.
A RETURN TO COOLER AND UNSETTLED CONDITIONS IS THEN ANTICIPATED
THIS WEEKEND AS ANOTHER UPPER DISTURBANCE IMPACTS THE FORECAST
DISTRICT. FINALLY...GUSTY WINDS WILL BE POSSIBLE OF MANY LOCATIONS
FROM WEDNESDAY INTO WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1011 AM MST TUE DEC 31 2013
AVN FORECAST FOR THE NEXT 24-36 HOURS IS A BIT OF A CHALLENGE.
FIRST CONCERN WILL BE FG PROBABILITIES FOR KALS TONIGHT. A WEAK
DISTURBANCE NOW COMING ONSHORE OVER OR WILL CROSS CO WED AM. THIS
WILL BRING INCREASED CLOUDS AND WINDS ALOFT...WHICH WILL MITIGATE
FG FORMATION. HOWEVER...AT THIS POINT IT LOOKS LIKE THE DISTURBANCE
WILL BE TOO WEAK TO COUNTER THE LIGHT WINDS...SNOW COVER...AND
COLD AIR TRAPPED IN THE SAN LUIS VALLEY. HAVE ADDED A CONSERVATIVE
PERIOD OF FG TO THE KALS TAF FOR LATE TONIGHT...BUT THERE IS A
GREAT DEAL OF UNCERTAINTY ON THE EXTENT AND TIMING OF FG COVERAGE
FOR THE VALLEY. PERSISTENCE LOOKS LIKE THE BEST BET FOR THE
CURRENT FORECAST...SO WILL GO WITH CONTINUED FG FOR NOW.
NEXT CHALLENGE IS THE CHANCES FOR PRECIP AT KPUB AND KCOS TOMORROW.
A COLD FRONT WILL DROP THROUGH WED AM AFTER 12Z...AND BRING LOW
CHANCES OF PRECIP TO THE CO PLAINS AND I-25 CORRIDOR. THE CHANCES
FOR -SN OR -SNRA WILL BE GREATEST LATE MORNING AND EARLY
AFTERNOON...BUT AT THIS TIME WITH THE PROB LESS THAN 20 PERCENT
WILL LEAVE EXPLICIT MENTION OF PRECIP OUT OF THE FORECAST. ANY
PRECIP WILL BE LIGHT...WITH NO SN ACCUMS EXPECTED. SHOWERS SHOULD
END FROM N TO S BY LATE WED AFTERNOON OR 00Z.
ONLY SURE BET WILL BE PERSISTENT LIGHT SHSN OVER THE SAWATCH
RANGE...ESPECIALLY N OF COTTONWOOD PASS AND VC KLXV THROUGH
WED MORNING. WINDS WILL INCREASE AGAIN AFTER 06Z TONIGHT FOR
THE RIDGE TOPS...AND LIGHT TO MDT MT WAVE ACTIVITY IS AGAIN A
POSSIBILITY WED AM JUST E OF THE RANGES. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ROSE
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
941 AM MST TUE DEC 31 2013
.UPDATE...
ISSUED AT 940 AM MST TUE DEC 31 2013
UPDATED GRIDS/ZONES TO INCREASE POPS A BIT OVER LAKE COUNTY...WHERE
PERSISTENT SHSN CONTINUE...AND ADJUST AREAL SKY COVERAGE. ROSE
UPDATE ISSUED AT 746 AM MST TUE DEC 31 2013
BASED ON LATEST OBS EXTENDED THE LIFR FOG IN KALS UNTIL 16Z. VIS
SHOULD IMPROVE AFTER 16Z WITH LIFR CIGS BREAKING BY 17Z. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM MST TUE DEC 31 2013
NEXT SHORTWAVE WILL BE RIDING THROUGH NORTHWEST FLOW ALOFT INTO
NORTHWEST COLORADO LATE TONIGHT. AHEAD OF THIS SYSTEM TODAY SHOULD
BE A WARM DAY WITH TEMPERATURES CLIMBING INTO THE 50S. ALREADY
STARTING TO SEE SOME WAVE CLOUDINESS AND THESE WILL CONTINUE TO
THICKEN AND SPREAD EASTWARD AS MORE MOISTURE EVIDENT IN WV PICS
CONTINUES TO STREAM IN FROM THE NORTHWEST THIS MORNING. THIS WILL
SERVE TO CUT BACK ON MAX TEMPS A BIT THIS AFTERNOON IN SOME
PLACES...ESPECIALLY ALONG THE ARKANSAS RIVER VALLEY WHERE WINDS MAY
HAVE A HARDER TIME MIXING DOWN. HRRR DEPICTS THIS IN SFC T FIELDS
NICELY. OTHER AREA WHERE TEMPS WILL REALLY STRUGGLE WILL BE ACROSS
THE SAN LUIS VALLEY WHERE SNOW COVER HAS ALREADY DROPPED MAX TEMPS
DOWN TO AROUND 10 BELOW ZERO THIS MORNING. DEPENDING ON HOW QUICKLY
AND THICKLY HIGH CLOUDS SPREAD IN LATER THIS MORNING...TEMPERATURES
MAY STRUGGLE TO GET INTO THE MID/UPPER TEENS. HAVE CUT BACK ON MAX
TEMPS THERE CONSIDERABLY OVER GUIDANCE. MEANWHILE FOG IN THE SAN
LUIS VALLEY SHOULD THIN SOME AS HIGH CLOUDINESS MOVES IN THROUGH THE
MORNING...THEN DISSIPATE ENTIRELY BY 16Z. MEANWHILE...CENTRAL
MOUNTAINS WILL SEE OROGRAPHIC SNOW SHOWERS SPREAD IN DURING THE
MORNING...THEN DECREASE A BIT TOWARDS AFTERNOON. ANY ACCUMULATIONS LOOK
LIGHT AT THIS POINT...AND CONFINED MOSTLY TO THE HIGHER ELEVATIONS
OF THE SAWATCH AND MOSQUITO RANGES.
TONIGHT...SNOW SHOULD START TO RAMP UP ALONG THE CONTINENTAL DIVIDE
TOWARDS 06Z...WITH A FEW SNOW SHOWERS POSSIBLY SPREADING INTO THE
HIGHER PEAKS OF THE SANGRES TOWARDS 12Z. HEAVIEST ACCUMULATIONS
WILL STAY CONFINED TO THE CENTRAL MOUNTAINS WHERE ANOTHER 1 TO 3
INCHES WILL BE POSSIBLE OVERNIGHT. WESTERLY WINDS INTO THE LEE SIDE
SFC LOW WILL KEEP MIN TEMPS WARM ALONG THE LOWER EASTERN SLOPES OF
THE SE MTS. A COLD FRONT WILL DROP THROUGH THE SOUTHEAST PLAINS
AFTER 09Z BRINGING AN INCREASE IN NORTH WINDS TOWARDS DAWN. GFS AND
ECMWF APPEAR TO HAVE TRENDED TOWARDS A MORE AMPLIFIED SOLN WITH THE
UPPER TROF AS IT MOVES ACROSS SE CO TOWARDS MORNING...BUT FOR NOW
THINK ANY LIGHT PRECIP WILL HOLD OFF UNTIL AFTER 12Z. -KT
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 516 AM MST TUE DEC 31 2013
NOT MANY METEOROLOGICAL ADJUSTMENTS NEEDED DURING THE LONGER TERM
WITH PRIMARY CONCERNS CONTINUING TO BE POPS...GUSTY WINDS AT TIMES
AND TEMPERATURES.
RECENT LONGER TERM COMPUTER SIMULATIONS INDICATES THAT A COUPLE
OF UPPER DISTURBANCES WILL CROSS THE FORECAST DISTRICT DURING THE
LONGER TERM WITH THE INITIAL SYSTEM IMPACTING THE CWFA NEW YEARS
DAYS AND ANOTHER SYSTEM IMPACTING SOUTHERN COLORADO DURING THE
WEEKEND.
THEN GENERALLY DRY AND MILD TO WARM CONDITIONS SHOULD DEVELOP
OVER THE FORECAST DISTRICT FROM THURSDAY INTO FRIDAY AS DRY
NORTHWESTERLY UPPER FLOW IMPACTS SOUTHERN COLORADO.
A RETURN TO COOLER AND UNSETTLED CONDITIONS IS THEN ANTICIPATED
THIS WEEKEND AS ANOTHER UPPER DISTURBANCE IMPACTS THE FORECAST
DISTRICT. FINALLY...GUSTY WINDS WILL BE POSSIBLE OF MANY LOCATIONS
FROM WEDNESDAY INTO WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 516 AM MST TUE DEC 31 2013
LIFR CONDITIONS IN STRATUS/FOG WILL CONTINUE AT KALS (EVIDENT IN NOT
ONLY THE KALS SFC OB...BUT ALSO IN THE CDOT WEB CAMS AT ALAMOSA AND
VILLA GROVE) THIS MORNING. HOWEVER...AS HIGH CLOUDS SPREAD IN
TOWARDS 12-14Z...SUSPECT THAT VISIBILITIES WILL INCREASE AROUND THAT
TIME...WITH LIFR CONDITIONS COMING TO AN END BETWEEN 14-15Z. MAY
HAVE TO TWEAK THE KALS TAF FOR TIMING AS NEEDED THIS MORNING.
OTHERWISE...VFR CONDITIONS EXPECTED...WITH BOUTS OF MID-HIGH LEVEL
WAVE CLOUDINESS SPREADING IN ACROSS THE TAF SITES THROUGH THE DAY.
THE CENTRAL MOUNTAINS WILL SEE SOME SCATTERED SNOW SHOWERS WITH MTN
OBSCURATIONS AT TIMES TODAY. TONIGHT...A COLD FRONT WILL DROP
THROUGH KCOS AND KPUB BETWEEN 09Z-12Z BRINGING A WIND SHIFT FROM THE
NORTH TO NORTHWEST AT AROUND 10-20 KTS. MEANWHILE...INCREASING
CLOUDINESS AHEAD OF THE NEXT SYSTEM MOVING IN TONIGHT SHOULD PREVENT
FOG FROM REDEVELOPING ACROSS THE SAN LUIS VALLEY. CIGS AT THE TAF
SITES WILL LIKELY REMAIN VFR. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...ROSE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
750 AM MST TUE DEC 31 2013
.UPDATE...
ISSUED AT 746 AM MST TUE DEC 31 2013
BASED ON LATEST OBS EXTENDED THE LIFR FOG IN KALS UNTIL 16Z. VIS
SHOULD IMPROVE AFTER 16Z WITH LIFR CIGS BREAKING BY 17Z. -KT
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM MST TUE DEC 31 2013
NEXT SHORTWAVE WILL BE RIDING THROUGH NORTHWEST FLOW ALOFT INTO
NORTHWEST COLORADO LATE TONIGHT. AHEAD OF THIS SYSTEM TODAY SHOULD
BE A WARM DAY WITH TEMPERATURES CLIMBING INTO THE 50S. ALREADY
STARTING TO SEE SOME WAVE CLOUDINESS AND THESE WILL CONTINUE TO
THICKEN AND SPREAD EASTWARD AS MORE MOISTURE EVIDENT IN WV PICS
CONTINUES TO STREAM IN FROM THE NORTHWEST THIS MORNING. THIS WILL
SERVE TO CUT BACK ON MAX TEMPS A BIT THIS AFTERNOON IN SOME
PLACES...ESPECIALLY ALONG THE ARKANSAS RIVER VALLEY WHERE WINDS MAY
HAVE A HARDER TIME MIXING DOWN. HRRR DEPICTS THIS IN SFC T FIELDS
NICELY. OTHER AREA WHERE TEMPS WILL REALLY STRUGGLE WILL BE ACROSS
THE SAN LUIS VALLEY WHERE SNOW COVER HAS ALREADY DROPPED MAX TEMPS
DOWN TO AROUND 10 BELOW ZERO THIS MORNING. DEPENDING ON HOW QUICKLY
AND THICKLY HIGH CLOUDS SPREAD IN LATER THIS MORNING...TEMPERATURES
MAY STRUGGLE TO GET INTO THE MID/UPPER TEENS. HAVE CUT BACK ON MAX
TEMPS THERE CONSIDERABLY OVER GUIDANCE. MEANWHILE FOG IN THE SAN
LUIS VALLEY SHOULD THIN SOME AS HIGH CLOUDINESS MOVES IN THROUGH THE
MORNING...THEN DISSIPATE ENTIRELY BY 16Z. MEANWHILE...CENTRAL
MOUNTAINS WILL SEE OROGRAPHIC SNOW SHOWERS SPREAD IN DURING THE
MORNING...THEN DECREASE A BIT TOWARDS AFTERNOON. ANY ACCUMULATIONS LOOK
LIGHT AT THIS POINT...AND CONFINED MOSTLY TO THE HIGHER ELEVATIONS
OF THE SAWATCH AND MOSQUITO RANGES.
TONIGHT...SNOW SHOULD START TO RAMP UP ALONG THE CONTINENTAL DIVIDE
TOWARDS 06Z...WITH A FEW SNOW SHOWERS POSSIBLY SPREADING INTO THE
HIGHER PEAKS OF THE SANGRES TOWARDS 12Z. HEAVIEST ACCUMULATIONS
WILL STAY CONFINED TO THE CENTRAL MOUNTAINS WHERE ANOTHER 1 TO 3
INCHES WILL BE POSSIBLE OVERNIGHT. WESTERLY WINDS INTO THE LEE SIDE
SFC LOW WILL KEEP MIN TEMPS WARM ALONG THE LOWER EASTERN SLOPES OF
THE SE MTS. A COLD FRONT WILL DROP THROUGH THE SOUTHEAST PLAINS
AFTER 09Z BRINGING AN INCREASE IN NORTH WINDS TOWARDS DAWN. GFS AND
ECMWF APPEAR TO HAVE TRENDED TOWARDS A MORE AMPLIFIED SOLN WITH THE
UPPER TROF AS IT MOVES ACROSS SE CO TOWARDS MORNING...BUT FOR NOW
THINK ANY LIGHT PRECIP WILL HOLD OFF UNTIL AFTER 12Z. -KT
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 516 AM MST TUE DEC 31 2013
NOT MANY METEOROLOGICAL ADJUSTMENTS NEEDED DURING THE LONGER TERM
WITH PRIMARY CONCERNS CONTINUING TO BE POPS...GUSTY WINDS AT TIMES
AND TEMPERATURES.
RECENT LONGER TERM COMPUTER SIMULATIONS INDICATES THAT A COUPLE
OF UPPER DISTURBANCES WILL CROSS THE FORECAST DISTRICT DURING THE
LONGER TERM WITH THE INITIAL SYSTEM IMPACTING THE CWFA NEW YEARS
DAYS AND ANOTHER SYSTEM IMPACTING SOUTHERN COLORADO DURING THE
WEEKEND.
THEN GENERALLY DRY AND MILD TO WARM CONDITIONS SHOULD DEVELOP
OVER THE FORECAST DISTRICT FROM THURSDAY INTO FRIDAY AS DRY
NORTHWESTERLY UPPER FLOW IMPACTS SOUTHERN COLORADO.
A RETURN TO COOLER AND UNSETTLED CONDITIONS IS THEN ANTICIPATED
THIS WEEKEND AS ANOTHER UPPER DISTURBANCE IMPACTS THE FORECAST
DISTRICT. FINALLY...GUSTY WINDS WILL BE POSSIBLE OF MANY LOCATIONS
FROM WEDNESDAY INTO WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 516 AM MST TUE DEC 31 2013
LIFR CONDITIONS IN STRATUS/FOG WILL CONTINUE AT KALS (EVIDENT IN NOT
ONLY THE KALS SFC OB...BUT ALSO IN THE CDOT WEB CAMS AT ALAMOSA AND
VILLA GROVE) THIS MORNING. HOWEVER...AS HIGH CLOUDS SPREAD IN
TOWARDS 12-14Z...SUSPECT THAT VISIBILITIES WILL INCREASE AROUND THAT
TIME...WITH LIFR CONDITIONS COMING TO AN END BETWEEN 14-15Z. MAY
HAVE TO TWEAK THE KALS TAF FOR TIMING AS NEEDED THIS MORNING.
OTHERWISE...VFR CONDITIONS EXPECTED...WITH BOUTS OF MID-HIGH LEVEL
WAVE CLOUDINESS SPREADING IN ACROSS THE TAF SITES THROUGH THE DAY.
THE CENTRAL MOUNTAINS WILL SEE SOME SCATTERED SNOW SHOWERS WITH MTN
OBSCURATIONS AT TIMES TODAY. TONIGHT...A COLD FRONT WILL DROP
THROUGH KCOS AND KPUB BETWEEN 09Z-12Z BRINGING A WIND SHIFT FROM THE
NORTH TO NORTHWEST AT AROUND 10-20 KTS. MEANWHILE...INCREASING
CLOUDINESS AHEAD OF THE NEXT SYSTEM MOVING IN TONIGHT SHOULD PREVENT
FOG FROM REDEVELOPING ACROSS THE SAN LUIS VALLEY. CIGS AT THE TAF
SITES WILL LIKELY REMAIN VFR. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KT
AREA FORECAST DISCUSSION
NWS PUEBLO CO
517 AM MST TUE DEC 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 516 AM MST TUE DEC 31 2013
NEXT SHORTWAVE WILL BE RIDING THROUGH NORTHWEST FLOW ALOFT INTO
NORTHWEST COLORADO LATE TONIGHT. AHEAD OF THIS SYSTEM TODAY SHOULD
BE A WARM DAY WITH TEMPERATURES CLIMBING INTO THE 50S. ALREADY
STARTING TO SEE SOME WAVE CLOUDINESS AND THESE WILL CONTINUE TO
THICKEN AND SPREAD EASTWARD AS MORE MOISTURE EVIDENT IN WV PICS
CONTINUES TO STREAM IN FROM THE NORTHWEST THIS MORNING. THIS WILL
SERVE TO CUT BACK ON MAX TEMPS A BIT THIS AFTERNOON IN SOME
PLACES...ESPECIALLY ALONG THE ARKANSAS RIVER VALLEY WHERE WINDS MAY
HAVE A HARDER TIME MIXING DOWN. HRRR DEPICTS THIS IN SFC T FIELDS
NICELY. OTHER AREA WHERE TEMPS WILL REALLY STRUGGLE WILL BE ACROSS
THE SAN LUIS VALLEY WHERE SNOW COVER HAS ALREADY DROPPED MAX TEMPS
DOWN TO AROUND 10 BELOW ZERO THIS MORNING. DEPENDING ON HOW QUICKLY
AND THICKLY HIGH CLOUDS SPREAD IN LATER THIS MORNING...TEMPERATURES
MAY STRUGGLE TO GET INTO THE MID/UPPER TEENS. HAVE CUT BACK ON MAX
TEMPS THERE CONSIDERABLY OVER GUIDANCE. MEANWHILE FOG IN THE SAN
LUIS VALLEY SHOULD THIN SOME AS HIGH CLOUDINESS MOVES IN THROUGH THE
MORNING...THEN DISSIPATE ENTIRELY BY 16Z. MEANWHILE...CENTRAL
MOUNTAINS WILL SEE OROGRAPHIC SNOW SHOWERS SPREAD IN DURING THE
MORNING...THEN DECREASE A BIT TOWARDS AFTERNOON. ANY ACCUMULATIONS LOOK
LIGHT AT THIS POINT...AND CONFINED MOSTLY TO THE HIGHER ELEVATIONS
OF THE SAWATCH AND MOSQUITO RANGES.
TONIGHT...SNOW SHOULD START TO RAMP UP ALONG THE CONTINENTAL DIVIDE
TOWARDS 06Z...WITH A FEW SNOW SHOWERS POSSIBLY SPREADING INTO THE
HIGHER PEAKS OF THE SANGRES TOWARDS 12Z. HEAVIEST ACCUMULATIONS
WILL STAY CONFINED TO THE CENTRAL MOUNTAINS WHERE ANOTHER 1 TO 3
INCHES WILL BE POSSIBLE OVERNIGHT. WESTERLY WINDS INTO THE LEE SIDE
SFC LOW WILL KEEP MIN TEMPS WARM ALONG THE LOWER EASTERN SLOPES OF
THE SE MTS. A COLD FRONT WILL DROP THROUGH THE SOUTHEAST PLAINS
AFTER 09Z BRINGING AN INCREASE IN NORTH WINDS TOWARDS DAWN. GFS AND
ECMWF APPEAR TO HAVE TRENDED TOWARDS A MORE AMPLIFIED SOLN WITH THE
UPPER TROF AS IT MOVES ACROSS SE CO TOWARDS MORNING...BUT FOR NOW
THINK ANY LIGHT PRECIP WILL HOLD OFF UNTIL AFTER 12Z. -KT
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 516 AM MST TUE DEC 31 2013
NOT MANY METEOROLOGICAL ADJUSTMENTS NEEDED DURING THE LONGER TERM
WITH PRIMARY CONCERNS CONTINUING TO BE POPS...GUSTY WINDS AT TIMES
AND TEMPERATURES.
RECENT LONGER TERM COMPUTER SIMULATIONS INDICATES THAT A COUPLE
OF UPPER DISTURBANCES WILL CROSS THE FORECAST DISTRICT DURING THE
LONGER TERM WITH THE INITIAL SYSTEM IMPACTING THE CWFA NEW YEARS
DAYS AND ANOTHER SYSTEM IMPACTING SOUTHERN COLORADO DURING THE
WEEKEND.
THEN GENERALLY DRY AND MILD TO WARM CONDITIONS SHOULD DEVELOP
OVER THE FORECAST DISTRICT FROM THURSDAY INTO FRIDAY AS DRY
NORTHWESTERLY UPPER FLOW IMPACTS SOUTHERN COLORADO.
A RETURN TO COOLER AND UNSETTLED CONDITIONS IS THEN ANTICIPATED
THIS WEEKEND AS ANOTHER UPPER DISTURBANCE IMPACTS THE FORECAST
DISTRICT. FINALLY...GUSTY WINDS WILL BE POSSIBLE OF MANY LOCATIONS
FROM WEDNESDAY INTO WEDNESDAY NIGHT.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 516 AM MST TUE DEC 31 2013
LIFR CONDITIONS IN STRATUS/FOG WILL CONTINUE AT KALS (EVIDENT IN NOT
ONLY THE KALS SFC OB...BUT ALSO IN THE CDOT WEB CAMS AT ALAMOSA AND
VILLA GROVE) THIS MORNING. HOWEVER...AS HIGH CLOUDS SPREAD IN
TOWARDS 12-14Z...SUSPECT THAT VISIBILITIES WILL INCREASE AROUND THAT
TIME...WITH LIFR CONDITIONS COMING TO AN END BETWEEN 14-15Z. MAY
HAVE TO TWEAK THE KALS TAF FOR TIMING AS NEEDED THIS MORNING.
OTHERWISE...VFR CONDITIONS EXPECTED...WITH BOUTS OF MID-HIGH LEVEL
WAVE CLOUDINESS SPREADING IN ACROSS THE TAF SITES THROUGH THE DAY.
THE CENTRAL MOUNTAINS WILL SEE SOME SCATTERED SNOW SHOWERS WITH MTN
OBSCURATIONS AT TIMES TODAY. TONIGHT...A COLD FRONT WILL DROP
THROUGH KCOS AND KPUB BETWEEN 09Z-12Z BRINGING A WIND SHIFT FROM THE
NORTH TO NORTHWEST AT AROUND 10-20 KTS. MEANWHILE...INCREASING
CLOUDINESS AHEAD OF THE NEXT SYSTEM MOVING IN TONIGHT SHOULD PREVENT
FOG FROM REDEVELOPING ACROSS THE SAN LUIS VALLEY. CIGS AT THE TAF
SITES WILL LIKELY REMAIN VFR. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TAUNTON MA
523 PM EST TUE DEC 31 2013
.SYNOPSIS...
ARCTIC AIR WILL BE IN CONTROL FOR MOST OF THE WEEK...ESPECIALLY
FRIDAY INTO SATURDAY WITH THE POTENTIAL FOR BITTERLY COLD
TEMPERATURES. CONCERN CONTINUES FOR A DEVELOPING STORM OFF THE
EASTERN SEABOARD THURSDAY INTO FRIDAY...WITH THE POTENTIAL FOR
PLOWABLE SNOW AND STRONG WINDS FOR PORTIONS OF THE REGION ALONG
WITH POSSIBLE COASTAL FLOODING.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AFTERNOON UPDATE...
REGIONAL RADAR MOSAICS SHOWING NEXT AREA OF SNOW SHOWERS ACROSS
NY STATE. THESE SHOWERS HAD SOME LAKE ENHANCEMENT. WHILE THE
CLOUDS ASSOCIATED WITH A CLIPPER MOVING THROUGH THE GREAT LAKES
WERE ALREADY SPILLING OVER THE BERKSHIRES...IT IS EXPECTED THAT
LOW- LEVEL MOISTURE WILL BE VERY TOUGH TO COME BY EAST OF THE
BERKSHIRES. THUS THE SNOW SHOWERS SHOULD WEAKEN AS THEY MOVE
FARTHER EAST. LATEST RUNS OF THE HRRR AND RAP SEEM TO BE HANDLING
THIS WELL...SO WILL USE THEM TO HANDLE THE REST OF THIS AFTERNOON.
FOR THE REST OF TONIGHT...A COLD FRONT WILL BE FOLLOWED BY A
REINFORCING SHOT OF VERY COLD AIR. ONCE ALL THE SNOW SHOWERS END
THIS EVENING...DRY AND COLD WEATHER PREVAILS FOR THE REST OF
TONIGHT. EXPECTING A FEW MORE CLOUDS TONIGHT THAN LAST NIGHT...SO
HAVE MINIMUM TEMPERATURES SLIGHTLY HIGHER THAN WHAT WE SAW TUESDAY
MORNING. WINDS WILL BE SLIGHTLY HIGHER TONIGHT...RESULTING IN
WIND CHILL VALUES SIMILAR TO LAST NIGHT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
CLOUDS INCREASE DURING THE DAY WEDNESDAY...WITH PREDOMINANTLY
OVERCAST SKIES EXPECTED FOR WEDNESDAY NIGHT. WITH A HIGH PRESSURE
CORE OVER SOUTHERN ONTARIO AND QUEBEC...THINKING WEDNESDAY WILL
REMAIN DRY.
DECENT OVERRUNNING COMBINED WITH A WEAK MID-LEVEL SHORTWAVE AND
SOME FRONTOGENESIS IN THE 925-850 MB LAYER SHOULD BE ENOUGH TO
GENERATE SOME LIGHT SNOW. ONSET TIMING COULD USE SOME
REFINEMENT...BUT CURRENTLY THINKING THE MAJORITY OF ANY SNOW
WEDNESDAY NIGHT WILL BE AFTER MIDNIGHT...AND POSSIBLY QUITE LATE
WEDNESDAY NIGHT ACROSS RI AND EASTERN MA.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* COASTAL STORM WITH SNOW...STRONG WINDS AND POSSIBLE COASTAL
EFFECTS THURSDAY INTO FRIDAY
* WELL BELOW NORMAL TEMPERATURES FOR FRIDAY AND SATURDAY
* ANOTHER POSSIBLE SYSTEM IMPACTING THE REGION SUNDAY NIGHT INTO
MONDAY
CONFIDENCE LEVEL...
MODERATE TO HIGH CONFIDENCE IN THE OVERALL FORECAST TREND WITH
THE SYSTEM THU INTO FRI...THEN HIGH PRES AND VERY COLD TEMPS INTO
THE WEEKEND. FURTHER OUT...CHANGING UPPER LEVEL PATTERN OVER THE
CENTRAL U.S. CAUSES TIMING ISSUES FOR ANOTHER LOW FROM SUN NIGHT
INTO TUE YIELDING LOW CONFIDENCE.
DETAILS...
THURSDAY INTO FRIDAY...
NOTING TWO PIECES OF UPPER LEVEL ENERGY...ONE MOVING OUT OF THE
CANADIAN ROCKIES AND A SECOND EXPECTED TO GATHER STRENGTH OVER THE
NORTHERN GULF OF MEXICO. EXPECT THESE TO DEVELOP LOW PRES MOVING
OFF THE OUTER BANKS OF NC LATE THU/THU NIGHT...THEN WILL TRACK
ABOUT 200 MILES S-SE OF NANTUCKET /SOUTH OF THE 40N/70W
BENCHMARK/. EVEN WITH THE LOW PASSING WELL S...STILL EXPECTING
QUITE A FEW HAZARDS DUE TO LONG E-NE FETCH BRINGING LL MOISTURE
WITH THE ARCTIC AIRMASS IN PLACE. EXPECTING AT LEAST MODERATE
SNOWFALL FOR MOST AREAS...STRONG WINDS CAUSING BLOWING AND
DRIFTING SNOW ALONG WITH BITTER COLD TEMPS. ALONG E FACING
BEACHES...WILL LIKELY SEE WIDESPREAD MINOR WITH POCKETS OF
MODERATE COASTAL FLOODING. DETAILS BELOW...
* MODELS...MOST OF THE MODEL SUITE IN RATHER GOOD AGREEMENT WITH THE
DEVELOPMENT OF THE LOW...OR EVEN SEVERAL WAVES OF LOW PRES WELL S
OF NEW ENGLAND...KEEPING SOME W-E PROGRESSION BUT HOLDING IN PLACE
THROUGH THIS TIMEFRAME. WITH THE HIGH SET UP OVER QUEBEC/N
MAINE...THIS KICKS UP THE ONSHORE FETCH OF LL MOISTURE. 00Z
ECMWF/12Z GFS ALONG WITH THEIR ENSEMBLES AND NOW...EVEN THE 12Z
UKMET...SETTING UP E-W SURFACE TROUGH. ALSO NOTING EXCELLENT 925-
850 HPA FGEN FORCING SETTING UP THU NIGHT ACROSS NE CT/RI/SE MA
WHICH WILL ONLY ENHANCE LIFT. STILL SOME SPREAD AMONGST THE GEFS
ENSEMBLE MEMBERS...THOUGH NOT QUITE AS MUCH AS SEEN IN EARLIER
RUNS. BEST AGREEMENT AND CONSISTENCY REMAINS WITH THE 00Z ECMWF/
12Z GFS AND THEIR ENSEMBLES. AVERAGE CONFIDENCE FORECAST.
* TEMPS...THERMAL PROFILES REMAIN MAINLY BELOW 0C. TEMPS START IN
THE LOWER-MID 30S ACROSS THE CAPE AND ISLANDS...BUT WILL DROP THU
NIGHT AND REMAIN COLD ON FRIDAY. TEMPS WILL RUN AT LEAST 10 TO 15
DEGREES BELOW NORMAL THROUGHOUT THIS EVENT...THEN WILL DROP EVEN
LOWER AS ANOTHER SHOT OF EVEN COLDER AIR WORKS IN DIRECTLY FROM
THE NORTH POLE. GUSTY N WINDS WILL CAUSE WIND CHILL VALUES TO
DROP BELOW -15F...SO WIND CHILL ADVISORIES MAY BE NEEDED FOR
CENTRAL AND WESTERN AREAS.
* SNOW...EXPECTING ALL SNOW FOR PTYPE WITH ARCTIC AIR IN PLACE ONLY
TURNING COLDER THU NIGHT AND FRI. H925 TEMPS RANGING BETWEEN -8C
TO -13C ACROSS THE AREA THU NIGHT THEN WILL DROP FURTHER FRI.
WITH DEEP LOW AND MID LEVEL MOISTURE ALONG WITH THE DEEP COLD
AIRMASS OVER THE REGION...EXPECTING HIGH SNOW TO WATER RATIOS ON
ORDER OF 15-20 TO ONE...YIELDING A POWDERY SNOW FOR MOST AREAS.
MAY BE A BIT LOWER ALONG THE IMMEDIATE E COAST WITH THE ONSHORE
WINDS. USED A BLEND OF THE PREVIOUS FORECAST AND GFS FOR QPF
FORECAST. LOOKS TO BE AROUND 0.3 TO 0.4 INCHES FOR MOST AREAS THU
NIGHT INTO EARLY FRI ALONE...WITH TOTAL OF 0.6 TO 0.8 INCHES
THROUGH THE EVENT. THEN...WITH THE NE WINDS BECOMING N...COULD SEE
MORE OCEAN EFFECT SNOWS LINGERING ALONG THE IMMEDIATE COAST MAINLY
OVER THE CAPE AND ISLANDS DURING FRIDAY. A BIT MORE CONFIDENCE ON
QPF AND SNOW TOTALS BUT STILL SOME TIME FOR ADJUSTMENTS IN TRACK
AND AMOUNTS.
* WIND...LARGE PRES GRADIENT DEVELOPS BETWEEN 1033 HPA HIGH OVER S
QUEBEC AND DEVELOPING LOW PRES WILL BRING INCREASING NE WINDS
ESPECIALLY ALONG THE E COAST. H925 JET AT 40-45 KT MOVES INTO SE
MA THU NIGHT INTO EARLY FRI...THEN BACKS TO N AS THE LOW PUSHES
OFFSHORE. EXPECT GUSTS TO REACH 35-40 KT...HIGHEST ON THE OUTER
CAPE AND NANTUCKET. WILL SEE CONSIDERABLE BLOWING AND DRIFTING
SNOW WITH THESE GUSTS WHICH WILL REDUCE VSBYS...ESPECIALLY ACROSS
COASTAL AREAS.
* COASTAL FLOODING...SEE DISCUSSION BELOW.
FRIDAY NIGHT THROUGH SUNDAY...
N-S ELONGATED HIGH PRES WILL BUILD OUT OF THE GREAT LAKES TO THE
SE U.S. WITH N-NW WINDS IN PLACE BRINGING ANOTHER SHOT OF ARCTIC
AIR TO THE REGION. COULD STILL SEE OCEAN EFFECT SNOWFALL OVER THE
MID AND OUTER CAPE AS WELL AS NANTUCKET FOR AT LEAST THE EARLY
PORTION OF FRI NIGHT. AS THE HIGH SETTLES OVER THE REGION...WINDS
WILL DIMINISH BUT IT WILL BE BITTERLY COLD. THE RELATIVELY MILDER
SPOTS WILL BE CAPE COD AND THE ISLANDS DUE TO THE WARMER OCEAN
WATERS. EXPECTING OVERNIGHT LOWS FRI NIGHT MAINLY FROM ZERO TO 10
BELOW FOR MOST INLAND AREAS EVEN INTO INTERIOR SE MA/NW RI AND N
CT...POSSIBLY EVEN LOWER ACROSS THE HIGHER TERRAIN OF SW NH/NW MA.
IT MIGHT EVEN TOUCH ZERO IN BOSTON...WHICH LAST OCCURRED JANUARY
24 2011 WHEN IT DROPPED TO -2. EVEN WITH LIGHT WINDS...THERE WILL
BE ENOUGH FOR WIND CHILL VALUES TO DROP TO -15F TO -20F /S TO N/.
MAY NEED A WIND CHILL ADVISORY FRIDAY NIGHT...INCLUDING THE CITY
OF BOSTON.
RIDGE MOVES OFFSHORE DURING SAT SO EXPECT DRY CONDITIONS WITH HIGHS
IN THE MID TEENS AND 20S INLAND TO AROUND 30 ACROSS CAPE COD AND THE
ISLANDS.
EXPECT RETURN SW FLOW TO KICK IN FOR SUNDAY BRINGING STRONG WARM AIR
ADVECTION TO THE REGION. HIGHS WILL RANGE FROM 30-35 ACROSS S NH TO
THE MID 40S ON THE CAPE AND ISLANDS. MODELS SIGNALING SOME POSSIBLE
PRECIP WORKING IN WITH THIS FLOW DURING THE AFTERNOON WITH A MIX OF
RAIN AND/OR SNOW SHOWERS.
SUNDAY NIGHT INTO TUESDAY...
LARGE MODEL DIFFERENCES CONTINUE DURING THIS TIMEFRAME. WEAK LOW
PRES MOVES NE ACROSS THE OHIO VALLEY TOWARD THE REGION SUN NIGHT
INTO MONDAY. HOWEVER...TIMING DIFFERENCES WITH THE MOVEMENT OF
THIS LOW BRINGS A LOT OF UNCERTAINTY AS TO PRECIP AMOUNT AND
TYPES. FOR NOW...LOOKS LIKE LOW SHOULD MOVE EITHER RIGHT ACROSS OR
TO THE W OF THE REGION...WHICH COULD MEAN SOME MIXED PRECIP WELL
INLAND AS COLD AIR TRIES TO HOLD IN PLACE. KEPT CHANCE POPS GOING
THROUGH MONDAY... THEN SHOULD START TAPERING OFF MON NIGHT.
FOR NOW...CARRIED MAINLY DRY POPS FOR TUESDAY...EXCEPT FOR SOME
POSSIBLE SNOW SHOWERS OVER THE CAPE AND ISLANDS WITH YET ANOTHER
SHOT OF COLD AIR.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR TERM /TODAY THROUGH WEDNESDAY AFTERNOON/...
THROUGH TONIGHT...HIGH CONFIDENCE VFR CONDITIONS MOST LOCATIONS.
THE EXCEPTION WILL BE BRIEFLY SCATTERED MVFR CIGS/VSBYS LATE THIS
AFTERNOON AND EARLY EVENING ACROSS THE WESTERN HALF OF SOUTHERN
NEW ENGLAND IN SNOW SHOWERS.
WEDNESDAY...HIGH CONFIDENCE VFR.
WEDNESDAY NIGHT...HIGH CONFIDENCE IN TRENDS...MODERATE CONFIDENCE
IN TIMING. CONDITIONS LOWERING TO MVFR IN SNOW...MAINLY AFTER
MIDNIGHT.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF. LOW PROBABILITY OF BRIEF MVFR
CONDITIONS LATE THIS AFTERNOON/EARLY EVENING.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY...IFR CIGS/VSBYS IN SNOW. LOCAL LIFR CONDITIONS LIKELY.
EAST TO NORTHEAST WINDS WITH GUSTS 30 TO 40 KT ALONG THE
COAST...HIGHEST ACROSS CAPE COD AND THE ISLANDS. SIGNIFICANT SNOW
ACCUMULATIONS LIKELY.
FRIDAY...IFR CONDITIONS IN SNOW FOR MOST AREAS THROUGH THE DAY.
CONDITIONS IMPROVE TO VFR FRIDAY AFTERNOON ACROSS WESTERN NEW
ENGLAND. BRIEF WIND GUSTS UP TO 40 KT POSSIBLE WITH THE INITIAL
SURGE OF ARCTIC AIR BEHIND DEPARTING LOW PRESSURE. EXPECT VFR FRIDAY
NIGHT...THOUGH COULD SEE MVFR-IFR IN THE EVENING ACROSS CAPE COD AND
NANTUCKET.
SATURDAY...VFR.
SUNDAY...VFR TO START...THEN AREAS OF MVFR FROM SW-NE DURING THE
AFTERNOON/NIGHT WITH RAIN AND/OR SNOW BY NIGHTFALL.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR TERM /TODAY THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
TONIGHT...A COLD FRONT CROSSES THE WATERS WITH A ROUND OF STRONG
WESTERLY WIND GUSTS UP TO 30 KT. SMALL CRAFT ADVISORIES POSTED
FOR MOST WATERS ALONG WITH POTENTIAL FOR LIGHT FREEZING SPRAY.
THERE COULD BE A BRIEF PERIOD OF GALE FORCE GUSTS BETWEEN 4 PM AND
9 PM. DECIDED TO NOT ISSUE A GALE WARNING AS GUSTS ARE MARGINAL
AND IT IS FOR A RELATIVELY SHORT PERIOD OF TIME.
WEDNESDAY...SMALL CRAFT ADVISORY WINDS/SEAS EARLY SHOULD
TEMPORARILY DIMINISH BELOW CRITERIA ACROSS ALL WATERS BY MID
AFTERNOON AS HIGH PRESSURE MOVES ACROSS THE WATERS.
WEDNESDAY NIGHT...RELATIVELY LIGHT WINDS AND SEAS EXPECTED. WINDS
TURN EAST AHEAD OF A NOREASTER MOVING SOUTH OF THE WATERS. SEAS
BEGIN TO REBUILD LATE WEDNESDAY NIGHT.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY...E-NE WINDS INCREASE DURING THE DAY...WITH GUSTS TO 35-40
KT DEVELOPING IN THE EVENING. SEAS BUILDING UP TO 10-18 FT HIGHEST
ON THE OUTER WATERS THU NIGHT. GALE WARNINGS WILL BE NEEDED.
FRIDAY...NE WINDS SHIFT TO N DURING THE DAY...WITH GUSTS OF 30-45
KNOTS. NW WINDS DIMINISH FRI NIGHT. SEAS WILL BE 15 TO 20 FEET ON
THE EASTERN WATERS AND 10 TO 15 FEET ON THE SOUTHERN WATERS.
SATURDAY...EXPECT WINDS AND SEAS DIMINISH...THOUGH WILL REMAIN IN
SMALL CRAFT CRITERIA.
SUNDAY...WINDS AND SEAS BELOW SMALL CRAFT CRITERIA.
&&
.TIDES/COASTAL FLOODING...
ECMWF AND GFS MODELS ALONG WITH THEIR ENSEMBLE MEMBERS HAVE TRENDED
TOWARD A MORE PROGRESSIVE/FURTHER SOUTHEAST TRACK WITH THE COASTAL
STORM THU-FRI. THIS REDUCES THE RISK OF MAJOR COASTAL FLOODING FOR
THE FRIDAY MIDDAY HIGH TIDE ALONG THE MA E COAST. NEVERTHELESS...THE
COMBINATION OF HIGH ASTRONOMICAL TIDES AND RELATIVELY LONG
DURATION AND FETCH OF NORTHEASTERLY WINDS SETS THE STAGE FOR
MINOR TO MODERATE COASTAL FLOODING FOR MULTIPLE HIGH TIDE CYCLES.
USING BOSTON AS AN INDEX...NOTE THAT ASTRONOMICAL HIGH TIDES ARE
VERY HIGH WITH 12.2 FEET MEAN LOWER LOW WATER AT BOSTON THU AND
FRI...AT 11:22 AM AND 12:15 PM RESPECTFULLY. THERE ALSO IS A 10.9
FOOT HIGH TIDE AT BOSTON THU NIGHT AROUND MIDNIGHT. AS USUAL IN
THESE SITUATIONS...HAVE GONE ABOVE BOTH THE ETSS AND ESTOFS
GUIDANCE BASED ON SYNOPTIC PATTERN RECOGNITION. BELIEVE ENOUGH
GRADIENT AND FETCH TO SUPPORT A STORM SURGE OF .5 TO
.75 FT THU MIDDAY...INCREASING TO 1.0 TO 2.0 FT FOR BOTH THE THU
NIGHT AND FRI MIDDAY TIDES...HIGHEST S OF BOSTON. THE SURGE MAY
ACTUALLY MAX OUT 2 TO 3 FT S OF BOSTON FRI MORNING...BUT DURING
THE LOW TIDE CYCLE. SEAS JUST OFFSHORE ARE EXPECTED TO REACH ABOUT
15 FT DURING THE THU NIGHT HIGH TIDE AND 15 TO 20 FT AT THE TIME
OF THE FRI MIDDAY HIGH TIDE. THE FRIDAY MIDDAY SEAS WILL CONTAIN
LONGER PERIOD SWELLS THAT BRING MORE ENERGY TO THE SHORE.
THIS IS ALL LIKELY TO RESULT IN MINOR COASTAL FLOODING FOR THE THU
MIDDAY HIGH TIDE AND MINOR TO MODERATE COASTAL FLOODING FOR THE
THU NIGHT HIGH TIDE. AT THIS TIME FOR THE FRI MIDDAY HIGH
TIDE...WE ARE PROJECTING MINOR TO ISOLATED MODERATE COASTAL
FLOODING N OF BOSTON AND AREAS OF MODERATE COASTAL FLOODING S OF
BOSTON. THERE REMAINS A RISK...ALBEIT LOOKING LOWER THAN 24 HOURS
AGO...OF POCKETS OF MODERATE TO MAJOR COASTAL FLOODING HULL THROUGH
SANDWICH AND NANTUCKET...ESPECIALLY IF THE STORM SHOULD END UP
BEING JUST A TAD SLOWER PULLING AWAY FROM OUR COASTLINE.
ALL VULNERABLE MA E FACING SHORELINES WILL HAVE A RISK OF SOME
BEACH EROSION GIVEN THE HIGH WATER LEVELS AND WAVE ACTION OVER
SUCCESSIVE TIDES. THE AREAS OF COASTLINE PRONE TO MORE SIGNIFICANT
BEACH EROSION INCLUDE THE PLYMOUTH COUNTY COAST...N SIDE OF THE
CAPE INCLUDING SANDWICH...THE OUTER CAPE OCEAN SIDE AND THE E SIDE
OF NANTUCKET.
NOT EXPECTING ANY COASTAL FLOODING PROBLEMS ALONG THE SOUTH COAST
GIVEN WIND DIRECTION AND EXPECTED TRACK OF THE STORM.
&&
.CLIMATE...
RECORD MINIMUM HIGH TEMPERATURES FOR JANUARY 3RD...
BOSTON 7 /1904/
HARTFORD 7 /1981/
PROVIDENCE 10 /1918/
WORCESTER 4 /1904/
RECORD LOW TEMPERATURES FOR JANUARY 4TH...
BOSTON -4 /1981/
HARTFORD -7 /1981/
PROVIDENCE -9 /1981/
WORCESTER -8 /1981/
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR ANZ231>235-
237.
SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR ANZ250-251.
SMALL CRAFT ADVISORY UNTIL 4 PM EST WEDNESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...BELK/EVT
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...EVT
AVIATION...BELK/EVT
MARINE...BELK/EVT
TIDES/COASTAL FLOODING...THOMPSON
CLIMATE...
AREA FORECAST DISCUSSION
NWS TAUNTON MA
453 PM EST TUE DEC 31 2013
.SYNOPSIS...
ARCTIC AIR WILL BE IN CONTROL FOR MOST OF THE WEEK...ESPECIALLY
FRIDAY INTO SATURDAY WITH THE POTENTIAL FOR BITTERLY COLD
TEMPERATURES. CONCERN CONTINUES FOR A DEVELOPING STORM OFF THE
EASTERN SEABOARD THURSDAY INTO FRIDAY...WITH THE POTENTIAL FOR
PLOWABLE SNOW AND STRONG WINDS FOR PORTIONS OF THE REGION ALONG
WITH POSSIBLE COASTAL FLOODING.
&&
.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
AFTERNOON UPDATE...
REGIONAL RADAR MOSAICS SHOWING NEXT AREA OF SNOW SHOWERS ACROSS
NY STATE. THESE SHOWERS HAD SOME LAKE ENHANCEMENT. WHILE THE
CLOUDS ASSOCIATED WITH A CLIPPER MOVING THROUGH THE GREAT LAKES
WERE ALREADY SPILLING OVER THE BERKSHIRES...IT IS EXPECTED THAT
LOW- LEVEL MOISTURE WILL BE VERY TOUGH TO COME BY EAST OF THE
BERKSHIRES. THUS THE SNOW SHOWERS SHOULD WEAKEN AS THEY MOVE
FARTHER EAST. LATEST RUNS OF THE HRRR AND RAP SEEM TO BE HANDLING
THIS WELL...SO WILL USE THEM TO HANDLE THE REST OF THIS AFTERNOON.
FOR THE REST OF TONIGHT...A COLD FRONT WILL BE FOLLOWED BY A
REINFORCING SHOT OF VERY COLD AIR. ONCE ALL THE SNOW SHOWERS END
THIS EVENING...DRY AND COLD WEATHER PREVAILS FOR THE REST OF
TONIGHT. EXPECTING A FEW MORE CLOUDS TONIGHT THAN LAST NIGHT...SO
HAVE MINIMUM TEMPERATURES SLIGHTLY HIGHER THAN WHAT WE SAW TUESDAY
MORNING. WINDS WILL BE SLIGHTLY HIGHER TONIGHT...RESULTING IN
WIND CHILL VALUES SIMILAR TO LAST NIGHT.
&&
.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
CLOUDS INCREASE DURING THE DAY WEDNESDAY...WITH PREDOMINANTLY
OVERCAST SKIES EXPECTED FOR WEDNESDAY NIGHT. WITH A HIGH PRESSURE
CORE OVER SOUTHERN ONTARIO AND QUEBEC...THINKING WEDNESDAY WILL
REMAIN DRY.
DECENT OVERRUNNING COMBINED WITH A WEAK MID-LEVEL SHORTWAVE AND
SOME FRONTOGENESIS IN THE 925-850 MB LAYER SHOULD BE ENOUGH TO
GENERATE SOME LIGHT SNOW. ONSET TIMING COULD USE SOME
REFINEMENT...BUT CURRENTLY THINKING THE MAJORITY OF ANY SNOW
WEDNESDAY NIGHT WILL BE AFTER MIDNIGHT...AND POSSIBLY QUITE LATE
WEDNESDAY NIGHT ACROSS RI AND EASTERN MA.
&&
.LONG TERM /THURSDAY THROUGH TUESDAY/...
HIGHLIGHTS...
* COASTAL STORM WITH SNOW...STRONG WINDS AND POSSIBLE COASTAL
EFFECTS THURSDAY INTO FRIDAY
* WELL BELOW NORMAL TEMPERATURES FOR FRIDAY AND SATURDAY
* ANOTHER POSSIBLE SYSTEM IMPACTING THE REGION SUNDAY NIGHT INTO
MONDAY
CONFIDENCE LEVEL...
MODERATE TO HIGH CONFIDENCE IN THE OVERALL FORECAST TREND WITH
THE SYSTEM THU INTO FRI...THEN HIGH PRES AND VERY COLD TEMPS INTO
THE WEEKEND. FURTHER OUT...CHANGING UPPER LEVEL PATTERN OVER THE
CENTRAL U.S. CAUSES TIMING ISSUES FOR ANOTHER LOW FROM SUN NIGHT
INTO TUE YIELDING LOW CONFIDENCE.
DETAILS...
THURSDAY INTO FRIDAY...
NOTING TWO PIECES OF UPPER LEVEL ENERGY...ONE MOVING OUT OF THE
CANADIAN ROCKIES AND A SECOND EXPECTED TO GATHER STRENGTH OVER THE
NORTHERN GULF OF MEXICO. EXPECT THESE TO DEVELOP LOW PRES MOVING
OFF THE OUTER BANKS OF NC LATE THU/THU NIGHT...THEN WILL TRACK
ABOUT 200 MILES S-SE OF NANTUCKET /SOUTH OF THE 40N/70W
BENCHMARK/. EVEN WITH THE LOW PASSING WELL S...STILL EXPECTING
QUITE A FEW HAZARDS DUE TO LONG E-NE FETCH BRINGING LL MOISTURE
WITH THE ARCTIC AIRMASS IN PLACE. EXPECTING AT LEAST MODERATE
SNOWFALL FOR MOST AREAS...STRONG WINDS CAUSING BLOWING AND
DRIFTING SNOW ALONG WITH BITTER COLD TEMPS. ALONG E FACING
BEACHES...WILL LIKELY SEE WIDESPREAD MINOR WITH POCKETS OF
MODERATE COASTAL FLOODING. DETAILS BELOW...
* MODELS...MOST OF THE MODEL SUITE IN RATHER GOOD AGREEMENT WITH THE
DEVELOPMENT OF THE LOW...OR EVEN SEVERAL WAVES OF LOW PRES WELL S
OF NEW ENGLAND...KEEPING SOME W-E PROGRESSION BUT HOLDING IN PLACE
THROUGH THIS TIMEFRAME. WITH THE HIGH SET UP OVER QUEBEC/N
MAINE...THIS KICKS UP THE ONSHORE FETCH OF LL MOISTURE. 00Z
ECMWF/12Z GFS ALONG WITH THEIR ENSEMBLES AND NOW...EVEN THE 12Z
UKMET...SETTING UP E-W SURFACE TROUGH. ALSO NOTING EXCELLENT 925-
850 HPA FGEN FORCING SETTING UP THU NIGHT ACROSS NE CT/RI/SE MA
WHICH WILL ONLY ENHANCE LIFT. STILL SOME SPREAD AMONGST THE GEFS
ENSEMBLE MEMBERS...THOUGH NOT QUITE AS MUCH AS SEEN IN EARLIER
RUNS. BEST AGREEMENT AND CONSISTENCY REMAINS WITH THE 00Z ECMWF/
12Z GFS AND THEIR ENSEMBLES. AVERAGE CONFIDENCE FORECAST.
* TEMPS...THERMAL PROFILES REMAIN MAINLY BELOW 0C. TEMPS START IN
THE LOWER-MID 30S ACROSS THE CAPE AND ISLANDS...BUT WILL DROP THU
NIGHT AND REMAIN COLD ON FRIDAY. TEMPS WILL RUN AT LEAST 10 TO 15
DEGREES BELOW NORMAL THROUGHOUT THIS EVENT...THEN WILL DROP EVEN
LOWER AS ANOTHER SHOT OF EVEN COLDER AIR WORKS IN DIRECTLY FROM
THE NORTH POLE. GUSTY N WINDS WILL CAUSE WIND CHILL VALUES TO
DROP BELOW -15F...SO WIND CHILL ADVISORIES MAY BE NEEDED FOR
CENTRAL AND WESTERN AREAS.
* SNOW...EXPECTING ALL SNOW FOR PTYPE WITH ARCTIC AIR IN PLACE ONLY
TURNING COLDER THU NIGHT AND FRI. H925 TEMPS RANGING BETWEEN -8C
TO -13C ACROSS THE AREA THU NIGHT THEN WILL DROP FURTHER FRI.
WITH DEEP LOW AND MID LEVEL MOISTURE ALONG WITH THE DEEP COLD
AIRMASS OVER THE REGION...EXPECTING HIGH SNOW TO WATER RATIOS ON
ORDER OF 15-20 TO ONE...YIELDING A POWDERY SNOW FOR MOST AREAS.
MAY BE A BIT LOWER ALONG THE IMMEDIATE E COAST WITH THE ONSHORE
WINDS. USED A BLEND OF THE PREVIOUS FORECAST AND GFS FOR QPF
FORECAST. LOOKS TO BE AROUND 0.3 TO 0.4 INCHES FOR MOST AREAS THU
NIGHT INTO EARLY FRI ALONE...WITH TOTAL OF 0.6 TO 0.8 INCHES
THROUGH THE EVENT. THEN...WITH THE NE WINDS BECOMING N...COULD SEE
MORE OCEAN EFFECT SNOWS LINGERING ALONG THE IMMEDIATE COAST MAINLY
OVER THE CAPE AND ISLANDS DURING FRIDAY. A BIT MORE CONFIDENCE ON
QPF AND SNOW TOTALS BUT STILL SOME TIME FOR ADJUSTMENTS IN TRACK
AND AMOUNTS.
* WIND...LARGE PRES GRADIENT DEVELOPS BETWEEN 1033 HPA HIGH OVER S
QUEBEC AND DEVELOPING LOW PRES WILL BRING INCREASING NE WINDS
ESPECIALLY ALONG THE E COAST. H925 JET AT 40-45 KT MOVES INTO SE
MA THU NIGHT INTO EARLY FRI...THEN BACKS TO N AS THE LOW PUSHES
OFFSHORE. EXPECT GUSTS TO REACH 35-40 KT...HIGHEST ON THE OUTER
CAPE AND NANTUCKET. WILL SEE CONSIDERABLE BLOWING AND DRIFTING
SNOW WITH THESE GUSTS WHICH WILL REDUCE VSBYS...ESPECIALLY ACROSS
COASTAL AREAS.
* COASTAL FLOODING...SEE DISCUSSION BELOW.
FRIDAY NIGHT THROUGH SUNDAY...
N-S ELONGATED HIGH PRES WILL BUILD OUT OF THE GREAT LAKES TO THE
SE U.S. WITH N-NW WINDS IN PLACE BRINGING ANOTHER SHOT OF ARCTIC
AIR TO THE REGION. COULD STILL SEE OCEAN EFFECT SNOWFALL OVER THE
MID AND OUTER CAPE AS WELL AS NANTUCKET FOR AT LEAST THE EARLY
PORTION OF FRI NIGHT. AS THE HIGH SETTLES OVER THE REGION...WINDS
WILL DIMINISH BUT IT WILL BE BITTERLY COLD. THE RELATIVELY MILDER
SPOTS WILL BE CAPE COD AND THE ISLANDS DUE TO THE WARMER OCEAN
WATERS. EXPECTING OVERNIGHT LOWS FRI NIGHT MAINLY FROM ZERO TO 10
BELOW FOR MOST INLAND AREAS EVEN INTO INTERIOR SE MA/NW RI AND N
CT...POSSIBLY EVEN LOWER ACROSS THE HIGHER TERRAIN OF SW NH/NW MA.
IT MIGHT EVEN TOUCH ZERO IN BOSTON...WHICH LAST OCCURRED JANUARY
24 2011 WHEN IT DROPPED TO -2. EVEN WITH LIGHT WINDS...THERE WILL
BE ENOUGH FOR WIND CHILL VALUES TO DROP TO -15F TO -20F /S TO N/.
MAY NEED A WIND CHILL ADVISORY FRIDAY NIGHT...INCLUDING THE CITY
OF BOSTON.
RIDGE MOVES OFFSHORE DURING SAT SO EXPECT DRY CONDITIONS WITH HIGHS
IN THE MID TEENS AND 20S INLAND TO AROUND 30 ACROSS CAPE COD AND THE
ISLANDS.
EXPECT RETURN SW FLOW TO KICK IN FOR SUNDAY BRINGING STRONG WARM AIR
ADVECTION TO THE REGION. HIGHS WILL RANGE FROM 30-35 ACROSS S NH TO
THE MID 40S ON THE CAPE AND ISLANDS. MODELS SIGNALING SOME POSSIBLE
PRECIP WORKING IN WITH THIS FLOW DURING THE AFTERNOON WITH A MIX OF
RAIN AND/OR SNOW SHOWERS.
SUNDAY NIGHT INTO TUESDAY...
LARGE MODEL DIFFERENCES CONTINUE DURING THIS TIMEFRAME. WEAK LOW
PRES MOVES NE ACROSS THE OHIO VALLEY TOWARD THE REGION SUN NIGHT
INTO MONDAY. HOWEVER...TIMING DIFFERENCES WITH THE MOVEMENT OF
THIS LOW BRINGS A LOT OF UNCERTAINTY AS TO PRECIP AMOUNT AND
TYPES. FOR NOW...LOOKS LIKE LOW SHOULD MOVE EITHER RIGHT ACROSS OR
TO THE W OF THE REGION...WHICH COULD MEAN SOME MIXED PRECIP WELL
INLAND AS COLD AIR TRIES TO HOLD IN PLACE. KEPT CHANCE POPS GOING
THROUGH MONDAY... THEN SHOULD START TAPERING OFF MON NIGHT.
FOR NOW...CARRIED MAINLY DRY POPS FOR TUESDAY...EXCEPT FOR SOME
POSSIBLE SNOW SHOWERS OVER THE CAPE AND ISLANDS WITH YET ANOTHER
SHOT OF COLD AIR.
&&
.AVIATION /22Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR TERM /TODAY THROUGH WEDNESDAY AFTERNOON/...
THROUGH TONIGHT...HIGH CONFIDENCE VFR CONDITIONS MOST LOCATIONS.
THE EXCEPTION WILL BE BRIEFLY SCATTERED MVFR CIGS/VSBYS LATE THIS
AFTERNOON AND EARLY EVENING ACROSS THE WESTERN HALF OF SOUTHERN
NEW ENGLAND IN SNOW SHOWERS.
WEDNESDAY...HIGH CONFIDENCE VFR.
WEDNESDAY NIGHT...HIGH CONFIDENCE IN TRENDS...MODERATE CONFIDENCE
IN TIMING. CONDITIONS LOWERING TO MVFR IN SNOW...MAINLY AFTER
MIDNIGHT.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF. LOW PROBABILITY OF BRIEF MVFR
CONDITIONS LATE THIS AFTERNOON/EARLY EVENING.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY...IFR CIGS/VSBYS IN SNOW. LOCAL LIFR CONDITIONS LIKELY.
EAST TO NORTHEAST WINDS WITH GUSTS 30 TO 40 KT ALONG THE
COAST...HIGHEST ACROSS CAPE COD AND THE ISLANDS. SIGNIFICANT SNOW
ACCUMULATIONS LIKELY.
FRIDAY...IFR CONDITIONS IN SNOW FOR MOST AREAS THROUGH THE DAY.
CONDITIONS IMPROVE TO VFR FRIDAY AFTERNOON ACROSS WESTERN NEW
ENGLAND. BRIEF WIND GUSTS UP TO 40 KT POSSIBLE WITH THE INITIAL
SURGE OF ARCTIC AIR BEHIND DEPARTING LOW PRESSURE. EXPECT VFR FRIDAY
NIGHT...THOUGH COULD SEE MVFR-IFR IN THE EVENING ACROSS CAPE COD AND
NANTUCKET.
SATURDAY...VFR.
SUNDAY...VFR TO START...THEN AREAS OF MVFR FROM SW-NE DURING THE
AFTERNOON/NIGHT WITH RAIN AND/OR SNOW BY NIGHTFALL.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR TERM /TODAY THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
TONIGHT...A COLD FRONT CROSSES THE WATERS WITH A ROUND OF STRONG
WESTERLY WIND GUSTS UP TO 30 KT. SMALL CRAFT ADVISORIES POSTED
FOR MOST WATERS ALONG WITH POTENTIAL FOR LIGHT FREEZING SPRAY.
THERE COULD BE A BRIEF PERIOD OF GALE FORCE GUSTS BETWEEN 4 PM AND
9 PM. DECIDED TO NOT ISSUE A GALE WARNING AS GUSTS ARE MARGINAL
AND IT IS FOR A RELATIVELY SHORT PERIOD OF TIME.
WEDNESDAY...SMALL CRAFT ADVISORY WINDS/SEAS EARLY SHOULD
TEMPORARILY DIMINISH BELOW CRITERIA ACROSS ALL WATERS BY MID
AFTERNOON AS HIGH PRESSURE MOVES ACROSS THE WATERS.
WEDNESDAY NIGHT...RELATIVELY LIGHT WINDS AND SEAS EXPECTED. WINDS
TURN EAST AHEAD OF A NOREASTER MOVING SOUTH OF THE WATERS. SEAS
BEGIN TO REBUILD LATE WEDNESDAY NIGHT.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY...E-NE WINDS INCREASE DURING THE DAY...WITH GUSTS TO 35-40
KT DEVELOPING IN THE EVENING. SEAS BUILDING UP TO 10-18 FT HIGHEST
ON THE OUTER WATERS THU NIGHT. GALE WARNINGS WILL BE NEEDED.
FRIDAY...NE WINDS SHIFT TO N DURING THE DAY...WITH GUSTS OF 30-45
KNOTS. NW WINDS DIMINISH FRI NIGHT. SEAS WILL BE 15 TO 20 FEET ON
THE EASTERN WATERS AND 10 TO 15 FEET ON THE SOUTHERN WATERS.
SATURDAY...EXPECT WINDS AND SEAS DIMINISH...THOUGH WILL REMAIN IN
SMALL CRAFT CRITERIA.
SUNDAY...WINDS AND SEAS BELOW SMALL CRAFT CRITERIA.
&&
.TIDES/COASTAL FLOODING...
LATEST ECMWF MODEL AND ITS ENSEMBLES HAS TRENDED MORE TOWARDS OTHER
GUIDANCE IN SHOWING A MORE PROGRESSIVE/FURTHER SOUTHEAST TRACK WITH
COASTAL STORM THU-FRI.
NONETHELESS...ASTRONOMICAL HIGH TIDES ARE VERY HIGH WITH 12.2 FEET
AT BOSTON THU AND FRI...AT 11:22 AM AND 12:15 PM RESPECTFULLY.
THERE ALSO IS A 10.9 FOOT HIGH TIDE THU NIGHT AROUND MIDNIGHT.
THEREFORE...EXPECT WIDESPREAD MINOR WITH THE POTENTIAL FOR POCKETS
OF MODERATE COASTAL FLOODING DURING THESE 3 HIGH TIDE CYCLES ALONG
THE EASTERN MA COAST. ANOTHER CONCERN WILL BE FOR BEACH EROSION IN
THIS REGION.
NOT EXPECTING ANY COASTAL FLOODING PROBLEMS ALONG THE SOUTH COAST
GIVEN WIND DIRECTION AND EXPECTED TRACK OF THE STORM.
&&
.CLIMATE...
RECORD MINIMUM HIGH TEMPERATURES FOR JANUARY 3RD...
BOSTON 7 /1904/
HARTFORD 7 /1981/
PROVIDENCE 10 /1918/
WORCESTER 4 /1904/
RECORD LOW TEMPERATURES FOR JANUARY 4TH...
BOSTON -4 /1981/
HARTFORD -7 /1981/
PROVIDENCE -9 /1981/
WORCESTER -8 /1981/
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR ANZ231>235-
237.
SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 10 AM EST WEDNESDAY FOR ANZ250-251.
SMALL CRAFT ADVISORY UNTIL 4 PM EST WEDNESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...BELK/EVT
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...EVT
AVIATION...BELK/EVT
MARINE...BELK/EVT
TIDES/COASTAL FLOODING...STAFF
CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS TAUNTON MA
226 PM EST TUE DEC 31 2013
.SYNOPSIS...
ARCTIC AIR WILL BE IN CONTROL FOR MOST OF THE WEEK...ESPECIALLY
FRI INTO SAT WITH THE POTENTIAL FOR BITTERLY COLD TEMPS. THE OTHER
MAIN CONCERN WILL BE A DEVELOPING COASTAL STORM THAT WILL BRING
THE POTENTIAL FOR SIGNIFICANT SNOW/STRONG WINDS AND COASTAL
FLOODING TO PORTIONS OF THE REGION THU INTO FRI.
&&
.NEAR TERM /THROUGH TONIGHT/...
230 PM UPDATE...REGIONAL RADAR MOSAICS SHOWING NEXT AREA OF SNOW
SHOWERS ACROSS NY STATE. THESE SHOWERS HAD SOME LAKE ENHANCEMENT.
WHILE THE CLOUDS ASSOCIATED WITH A CLIPPER MOVING THROUGH THE
GREAT LAKES WERE ALREADY SPILLING OVER THE BERKSHIRES...IT IS
EXPECTED THAT LOW-LEVEL MOISTURE WILL BE VERY TOUGH TO COME BY
EAST OF THE BERKSHIRES. THUS THE SNOW SHOWERS SHOULD WEAKEN AS
THEY MOVE FARTHER EAST. LATEST RUNS OF THE HRRR AND RAP SEEM TO BE
HANDLING THIS WELL...SO WILL USE THEM TO HANDLE THE REST OF THIS
AFTERNOON.
FOR THE REST OF TONIGHT...A COLD FRONT WILL BE FOLLOWED BY A
REINFORCING SHOT OF VERY COLD AIR. ONCE ALL THE SNOW SHOWERS END
THIS EVENING...DRY AND COLD WEATHER PREVAILS FOR THE REST OF
TONIGHT. EXPECTING A FEW MORE CLOUDS TONIGHT THAN LAST NIGHT...SO
HAVE MINIMUM TEMPERATURES SLIGHTLY HIGHER THAN WHAT WE SAW
TUESDAY MORNING. WINDS WILL BE SLIGHTLY HIGHER TONIGHT...RESULTING
IN WIND CHILL VALUES SIMILAR TO LAST NIGHT.
&&
.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
CLOUDS INCREASE DURING THE DAY WEDNESDAY...WITH PREDOMINANTLY
OVERCAST SKIES EXPECTED FOR WEDNESDAY NIGHT. WITH A HIGH PRESSURE
CORE OVER SOUTHERN ONTARIO AND QUEBEC...THINKING WEDNESDAY WILL
REMAIN DRY.
DECENT OVERRUNNING COMBINED WITH A WEAK MID-LEVEL SHORTWAVE AND
SOME FRONTOGENESIS IN THE 925-850 MB LAYER SHOULD BE ENOUGH TO
GENERATE SOME LIGHT SNOW. ONSET TIMING COULD USE SOME
REFINEMENT...BUT CURRENTLY THINKING THE MAJORITY OF ANY SNOW
WEDNESDAY NIGHT WILL BE AFTER MIDNIGHT...AND POSSIBLY QUITE LATE
WEDNESDAY NIGHT ACROSS RI AND EASTERN MA.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
HIGHLIGHTS...
* COASTAL STORM WITH A VARIETY OF HAZARDS THURS INTO FRIDAY
* WELL BELOW AVG TEMPERATURES FOR FRI AND SAT
* ANOTHER POSSIBLE SYSTEM IMPACTING THE REGION SUN NIGHT INTO MON
CONFIDENCE LEVEL...MODERATE CONFIDENCE IN THE OVERALL TREND OF
THE FORECAST WITH A LOW CONFIDENCE IN SPECIFICS OF THE FORECAST.
HIGH CONFIDENCE IN PRECIPITATION ON THURSDAY INTO FRIDAY AS WELL
AS EXTREMELY COLD TEMPS FOR FRIDAY INTO SATURDAY. BEYOND THAT DUE
TO SIGNIFICANT MODEL DIVERGENCE...HAVE A LOW CONFIDENCE.
DETAILS...
THURSDAY INTO FRIDAY...
PIECE OF ENERGY FOR A SIGNIFICANT COASTAL SYSTEM IS STILL
OFFSHORE OF BRITISH COLUMBIA BUT WILL EVENTUALLY DIVE INTO THE
SOUTHERN PLAINS BY DAY 2. THIS ENERGY WILL DEVELOP A LOW PRESSURE
OFF THE COAST OF NC AND EVENTUALLY TRACK JUST SOUTHEAST OF THE
40N/70W BENCHMARK. ALTHOUGH NOT A TRUE BENCHMARK STORM...THIS
PROGRESSIVE SYSTEM IS STILL PACKING A LOT OF PUNCH THAT WILL
INVOLVE WIDESPREAD MINOR WITH POCKETS OF MODERATE COASTAL
FLOODING...MODERATE SNOWFALL ACCUMULATIONS...STRONG WINDS CAUSING
BLOWING AND DRIFTING SNOW AND BITTER COLD TEMPS. DETAILS BELOW.
* MODELS...MODELS ARE STARTING TO COME MORE ALIGN AMONGST ONE
ANOTHER AS BOTH DETERMINISTIC AND THEIR ENSEMBLES HAVE TRENDED
TO BE MORE PROGRESSIVE. THE CANADIAN AND UKMET STILL SEEM TO BE
OUTLIERS BEING THE FURTHEREST OUT TO SEA. THE 00Z EC HAS SPED UP
AND IS MORE PROGRESSIVE THEN ITS 12Z COUNTERPART. THE EC
ENSEMBLES ARE ALSO MORE PROGRESSIVE AND LINE UP WITH THE GEFS.
THEREFORE TRENDED THE FORECAST TOWARDS A GFS/EC/PREV FORECAST
COMPROMISE. ONE THING TO NOTE IS THAT THERE IS STILL SIGNIFICANT
SPREAD AMONGST THE INDIVIDUAL GEFS MEMBERS AS WELL AS A
SIGNIFICANT TRACK SHIFT/ERROR IS STILL POSSIBLE AS WE ARE STILL
72 HOURS OUT. SO CONTINUED WITH A BELOW CONFIDENCE FORECAST.
* TEMPS...NO ISSUES WITH P-TYPE AS THERMAL PROFILES WILL ALL BE
BELOW 0C. SURFACE TEMPERATURES WILL BE BELOW AVERAGE AT THE ONSET
OF THIS SYSTEM BUT WILL QUICKLY PLUMMET INTO THE SINGLE DIGITS ONCE
WHEN THE WINDS SWITCH TO A NORTHERLY DIRECTION. THIS WILL ALLOW
FOR A MORE POWDERY SNOW. THE EXPECTED GUSTY WINDS COMBINED WITH
THE VERY COLD TEMPERATURES...WIND CHILL ADV MAY BE NEEDED FOR
CENTRAL AND WESTERN MA AS WIND CHILL VALUES DROP BELOW -15F.
* SNOW...HIGH CONFIDENCE THAT P-TYPE WILL BE ALL SNOW THANKS TO
THE REINFORCING ARCTIC AIR MOVING INTO SOUTHERN NEW ENGLAND
DURING THE EVENT. FOR EXAMPLE...925MB TEMPS RANGE BETWEEN -18C
TO -6C ACROSS THE AREA FROM THURSDAY INTO FRIDAY. SOUNDING AND
MODELS SHOW DEEP SATURATION THROUGHOUT THE SNOW GROWTH REGION SO
HAVE LITTLE DOUBT THAT MOISTURE WILL BE AN ISSUE. TRENDED QPF AS
A COMBO OF THE GFS/EC AS IT IS IN GOOD JUNCTION WITH ITS
ENSEMBLES. OVERALL APPEARS THAT AT LEAST 0.5 INCHES OF QPF WILL
FALL THROUGHOUT THE EVENT WITH HIGHER AMOUNTS LIKELY NEAR THE
EAST COASTLINE. FINALLY WITH PERSISTENT NORTHEAST WIND...THERE
IS A POSSIBILITY OF OCEAN EFFECT SNOW SHOWERS. LOOKING AT ALL OF
THESE FACTORS...THERE IS INCREASING CONFIDENCE THAT AT LEAST 6
INCHES OF SNOW WILL OCCUR WITH POSSIBLE HIGHER AMOUNTS CLOSER TO
THE EAST AND SE COASTLINES. THE REGION OF HIGHEST UNCERTAINTY IS
ACROSS S NH AND NW MA WHERE A SHIFT IN THE TRACK COULD REDUCE
THEIR AMOUNTS. AS MENTIONED BEFORE THERE IS STILL A LOT OF
UNCERTAINTY AND THESE AMOUNTS AND PROJECTIONS COULD SHIFT A FEW
MORE TIMES.
* WIND...SIGNIFICANT PRESSURE GRADIENT WITH THIS SYSTEM AS IT MOVES
SOUTH AND EAST OF THE BENCHMARK. THIS WILL CREATE VERY GUSTY WINDS
ACROSS THE AREA. 925 MB WIND SPEEDS SHOW A JET BETWEEN 40-55 KTS
LATE THURSDAY INTO FRIDAY MORNING OVER THE SOUTHERN COASTAL PLAIN
INCLUDING RI COAST...THE CAPE AND THE ISLANDS. THIS MAY ALLOW FOR
SURFACE WINDS TO SUSTAIN AROUND 20 TO 30MPH ACROSS THE MENTIONED
REGION WITH GUSTS BETWEEN 35 TO 45MPH. WITH THESE KIND OF
GUSTS...EXPECT SIGNIFICANT BLOWING AND DRIFTING SNOW...REDUCING
VSBYS. AGAIN THE MAIN REGION OF CONCERN FOR THE STRONG WIND GUSTS
IS ACROSS THE SE COASTAL PLAIN INCLUDING THE RI COAST...CAPE AND
THE ISLANDS.
* COASTAL FLOODING...SEE DISCUSSION BELOW.
FRIDAY NIGHT INTO SUNDAY...STORM SYSTEM WILL EJECT INTO THE GULF
OF MAINE BY FRIDAY NIGHT ALLOWING FOR HIGH PRESSURE TO BUILD IN
ACROSS THE REGION. THIS ARCTIC HIGH PRESSURE WILL ALLOW FOR
SIGNIFICANT RADIATIONAL COOLING ON FRIDAY NIGHT. TEMPS WILL BE
WELL BELOW AVERAGE WITH SURFACE TEMPERATURES AT LEAST 2 TO 3
STANDARD DEVIATIONS AWAY. TEMPS WILL DROP BELOW ZERO INCLUDING THE
METRO REGIONS. WARM SPOTS WILL BE THE CAPE AND THE ISLANDS THANKS
TO THE WARMER OCEAN WATERS. THESE BITTER COLD TEMPS MAY WARRANT A
WIND CHILL ADVISORY FRIDAY NIGHT AS WIND CHILLS DROP TO BELOW -20F
NORTH OF THE MASS PIKE...WITH -15F NORTH OF I-95...INCLUDING THE
CITY OF BOSTON.
SLIGHT RIDGING ALOFT WILL ALLOW FOR A WARMUP ON SATURDAY AND INTO
SUNDAY. SAT HIGHS WILL ONLY REACH THE MID TEENS TO LOW 20S WHILE
HIGHS SUNDAY WILL BE ABOVE FREEZING THANKS TO SIGNIFICANT WAA AT
850MB.
SUNDAY NIGHT INTO MONDAY...
MODELS GREATLY DIVERGE FOR THIS TIMEFRAME. APPEARS ANOTHER SYSTEM
WILL APPROACH THE REGION DURING THE SUNDAY NIGHT INTO MONDAY
TIMEFRAME. STILL A LOT OF UNCERTAINTY AS THE GFS BRINGS A COLD
FRONT ACROSS THE REGION WHILE THE LATEST EC TRIES TO DEVELOP AN
INLAND RUNNER. FOR NOW FOLLOWED WPC AND KEPT CHANCE POPS IN FOR
THIS TIME FAME AND WILL HASH OUT THE DETAILS LATER THIS WEEK.
&&
.AVIATION /19Z TUESDAY THROUGH SUNDAY/...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR TERM /TODAY THROUGH WEDNESDAY AFTERNOON/...
THROUGH TONIGHT...HIGH CONFIDENCE VFR CONDITIONS MOST LOCATIONS.
THE EXCEPTION WILL BE BRIEFLY SCATTERED MVFR CIGS/VSBYS LATE THIS
AFTERNOON AND EARLY EVENING ACROSS THE WESTERN HALF OF SOUTHERN
NEW ENGLAND IN SNOW SHOWERS.
WEDNESDAY...HIGH CONFIDENCE VFR.
WEDNESDAY NIGHT...HIGH CONFIDENCE IN TRENDS...MODERATE CONFIDENCE
IN TIMING. CONDITIONS LOWERING TO MVFR IN SNOW...MAINLY AFTER
MIDNIGHT.
KBOS TAF...HIGH CONFIDENCE IN TAF.
KBDL TAF...HIGH CONFIDENCE IN TAF. LOW PROBABILITY OF BRIEF MVFR
CONDITIONS LATE THIS AFTERNOON/EARLY EVENING.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY...IFR CIGS/VSBYS IN SNOW. THIS MAY LEAD TO SIGNIFICANT
ACCUMULATIONS...ESPECIALLY IN THE LATE AFTERNOON AND AT NIGHT.
EAST TO NORTHEAST WINDS WITH GUSTS 30 TO 45 KT ALONG THE COAST.
FRIDAY...IFR CONDITIONS IN SNOW TO START THE DAY. CONDITIONS
IMPROVING TO VFR FRIDAY AFTERNOON ACROSS WESTERN NEW ENGLAND. BRIEF
WIND GUSTS UP TO 40 KT POSSIBLE WITH THE INITIAL SURGE OF ARCTIC AIR
BEHIND DEPARTING LOW PRESSURE.
SATURDAY...VFR WITH SOME GUSTY WINDS NEAR THE COAST.
&&
.MARINE...
FORECASTER CONFIDENCE LEVELS...
LOW...LESS THAN 30 PERCENT.
MODERATE...30 TO 60 PERCENT.
HIGH...GREATER THAN 60 PERCENT.
NEAR TERM /TODAY THROUGH WEDNESDAY NIGHT/...HIGH CONFIDENCE.
TONIGHT...A COLD FRONT CROSSES THE WATERS WITH A ROUND OF STRONG
WESTERLY WIND GUSTS UP TO 30 KT. SMALL CRAFT ADVISORIES POSTED
FOR MOST WATERS ALONG WITH POTENTIAL FOR LIGHT FREEZING SPRAY.
THERE COULD BE A BRIEF PERIOD OF GALE FORCE GUSTS BETWEEN 4 PM AND
9 PM. DECIDED TO NOT ISSUE A GALE WARNING AS GUSTS ARE MARGINAL
AND IT IS FOR A RELATIVELY SHORT PERIOD OF TIME.
WEDNESDAY...SMALL CRAFT ADVISORY WINDS/SEAS EARLY SHOULD
TEMPORARILY DIMINISH BELOW CRITERIA ACROSS ALL WATERS BY MID
AFTERNOON AS HIGH PRESSURE MOVES ACROSS THE WATERS.
WEDNESDAY NIGHT...RELATIVELY LIGHT WINDS AND SEAS EXPECTED. WINDS
TURN EAST AHEAD OF A NOREASTER MOVING SOUTH OF THE WATERS. SEAS
BEGIN TO REBUILD LATE WEDNESDAY NIGHT.
OUTLOOK...THURSDAY THROUGH SUNDAY...MODERATE CONFIDENCE.
THURSDAY...WINDS INCREASE OUT OF THE EAST IN THE MORNING WITH
EAST TO NORTHEAST GUSTS TO 40 KNOTS DEVELOPING IN THE EVENING.
SEAS BUILD ABOVE 5 FEET BY AFTERNOON. THE EASTERN MASSACHUSETTS
WATERS MAY HAVE SEAS BUILD TO 15 FEET OVERNIGHT. GALE WARNINGS
WILL BE NEEDED.
FRIDAY...NORTH WINDS WITH GUSTS OF 30-45 KNOTS. EASTERN SEA
HEIGHTS WILL BE 10 TO 20 FEET...SOUTHERN OCEAN WATERS WILL BE 10
TO 15 FEET. GALE WARNINGS WILL WILL BE NEEDED.
SATURDAY...WINDS AND SEAS DIMINISH AS A HIGH PRESSURE BUILDS OVER
THE WATERS. SMALL CRAFT ADVISORIES LIKELY TO CONTINUE...AT LEAST
ACROSS THE OUTER COASTAL WATERS.
&&
.TIDES/COASTAL FLOODING...
LATEST ECMWF MODEL AND ITS ENSEMBLES HAS TRENDED MORE TOWARDS OTHER
GUIDANCE IN SHOWING A MORE PROGRESSIVE/FURTHER SOUTHEAST TRACK WITH
COASTAL STORM THU-FRI.
NONETHELESS...ASTRONOMICAL HIGH TIDES ARE VERY HIGH WITH 12.2 FEET
AT BOSTON THU AND FRI...AT 11:22 AM AND 12:15 PM RESPECTFULLY.
THERE ALSO IS A 10.9 FOOT HIGH TIDE THU NIGHT AROUND MIDNIGHT.
THEREFORE...EXPECT WIDESPREAD MINOR WITH THE POTENTIAL FOR POCKETS
OF MODERATE COASTAL FLOODING DURING THESE 3 HIGH TIDE CYCLES ALONG
THE EASTERN MA COAST. ANOTHER CONCERN WILL BE FOR BEACH EROSION IN
THIS REGION.
NOT EXPECTING ANY COASTAL FLOODING PROBLEMS ALONG THE SOUTH COAST
GIVEN WIND DIRECTION AND EXPECTED TRACK OF THE STORM.
&&
.CLIMATE...
RECORD MINIMUM HIGH TEMPERATURES FOR JANUARY 3RD...
BOSTON 7 /1904/
HARTFORD 7 /1981/
PROVIDENCE 10 /1918/
WORCESTER 4 /1904/
RECORD LOW TEMPERATURES FOR JANUARY 4TH...
BOSTON -4 /1981/
HARTFORD -7 /1981/
PROVIDENCE -9 /1981/
WORCESTER -8 /1981/
&&
.BOX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
MA...NONE.
NH...NONE.
RI...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THIS EVENING TO 10 AM EST
WEDNESDAY FOR ANZ231>235-237-250-251.
SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 4 AM EST
WEDNESDAY FOR ANZ230.
SMALL CRAFT ADVISORY UNTIL 4 PM EST WEDNESDAY FOR ANZ254>256.
&&
$$
SYNOPSIS...BELK/DUNTEN
NEAR TERM...BELK
SHORT TERM...BELK
LONG TERM...DUNTEN
AVIATION...BELK/DUNTEN
MARINE...BELK/DUNTEN
TIDES/COASTAL FLOODING...STAFF
CLIMATE...STAFF
AREA FORECAST DISCUSSION
NWS NEW YORK NY
100 PM EST TUE DEC 31 2013
.SYNOPSIS...
A COLD FRONT WILL MOVE THROUGH THE REGION LATE TODAY. ARCTIC HIGH
PRESSURE BUILDS TO THE NORTH OF THE REGION THROUGH MIDWEEK. A
STALLED FRONTAL BOUNDARY DEVELOPS NEAR THE AREA WED NIGHT WITH
WEAK LOW PRESSURE APPROACHING FROM THE OHIO VALLEY. A STRONGER LOW
PRESSURE SYSTEM WILL DEVELOP OFF THE CAROLINA COAST ON THURSDAY
AND TRACK NORTHEAST PASSING SOUTHEAST OF LONG ISLAND THURSDAY
NIGHT INTO FRIDAY. HIGH PRESSURE RETURNS FOR THE WEEKEND WITH A
FRONTAL SYSTEM MOVING THROUGH SUN NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MAX TEMPS WERE LOWERED SLIGHTLY BY A FEW DEGREES TO MATCH OBSERVED
TRENDS WITH TEMPERATURES. LOOKING AT PARAMETERS OF
FRONTOGENESIS...SURFACE BASED CAPE...POTENTIAL INSTABILITY...THE
INCREASE IN FRONTOGENESIS COMBINED WITH LESS THAN 50 J/KG OF CAPE
AS WELL AS A LITTLE POTENTIAL INSTABILITY FROM NEGATIVE TREND OF
THETA-E WITH HEIGHT...POTENTIAL IS THERE FOR SNOW SHOWERS AND SNOW
SQUALLS AS WELL. HRRR AND HIRES NMM BOTH SHOW DISCRETE CELLS OF
20-30 DBZ MOVING ACROSS IN THE 21Z-00Z TIMEFRAME. THEREFORE THAT
PORTION OF THE FORECAST REMAINS NEARLY THE SAME AS BEFORE. A
SLIGHT ADJUSTMENT UP WAS MADE WITH SNOW ACROSS INTERIOR SECTIONS
WHERE HIGHER OMEGA WAS SEEN WITHIN THE DENDRITIC SNOW GROWTH ZONE
COMPARED TO FARTHER SOUTH WHERE LESS OMEGA WAS SEEN IN THIS ZONE.
THIS ANALYSIS WAS DONE LOOKING AT BUFKIT SOUNDINGS.
POTENTIAL FOR LOCALIZED SNOW SQUALLS WITH FLASH FREEZE CONDITIONS
DURING EVENING COMMUTE...
MODELS IN GOOD AGREEMENT WITH NORTHERN STREAM SHORTWAVE AND
ACCOMPANYING CLIPPER OVER THE GREAT LAKES EARLY THIS
MORNING...SWINGING INTO THE NORTHEAST THIS AFTERNOON. MODELS
CONTINUE TO SHOW SOUTHERN STREAM ENERGY STAYING UNPHASED...WITH
ANY COASTAL DEVELOPMENT STAYING WELL SOUTH OF THE REGION.
SHORTWAVE APPROACHES THIS MORNING WITH INCREASING CLOUD COVER
ACROSS THE AREA...AND PIVOTS THROUGH THIS AFTERNOON. CLIPPER LOW
STAYS WELL TO THE NORTH BUT TRAILING COLD FRONT PUSHES THROUGH
LATE TODAY/THIS EVENING.
COMBINATION OF MODEST SHORTWAVE LIFT AND MOISTURE CONVERGENCE
AHEAD OF COLD FRONT...WITH A BIT OF LOW-LEVEL INSTABILITY...POINTS
TOWARDS SCATTERED SNOW SHOWER ACTIVITY WORKING INTO WESTERN
PORTIONS OF THE REGION LATE THIS AFTERNOON AHEAD OF THE COLD
FRONT...AND THEN TRAVERSING EAST THROUGH EARLY EVENING. COVERAGE
LIKELY IN THE 25 TO 35 PERCENT RANGE. BASED ON ABOVE AND HIGH RES
MODEL OUTPUT...ISOLATED SNOW SQUALLS (15-20 PERCENT PROBABILITY) WITH
BRIEF WHITE OUT CONDITIONS AND A QUICK COATING OF SNOW ARE
POSSIBLE. ANY AREA EXPERIENCING A SNOW SQUALL WILL HAVE POTENTIAL
FOR FLASH FREEZE CONDITIONS AS TEMPS START OUT AROUND OR JUST
ABOVE FREEZING AND THEN DROP INTO THE 20S IN THE WAKE OF COLD
PASSAGE.
ANY SNOW SHOWER/SNOW SQUALL ACTIVITY WILL QUICKLY COME TO AN END
BEHIND FRONTAL PASSAGE...WITH A BRIEF PERIOD OF STRONG WINDS GUSTS
LIKELY IMMEDIATELY BEHIND COLD FRONTAL PASSAGE LATE THIS
AFTERNOON/EARLY EVENING. GUSTS TO 35 MPH LIKELY AND TO 40 MPH
POSSIBLE DURING THE LATE AFTERNOON/EARLY EVENING WITH DEEP MIXING
AND WIND PROFILE SUPPORTING GOOD MOMENTUM TRANSFER.
TEMPS LIKELY A COUPLE OF DEGREES BELOW SEASONABLE TODAY
PARTICULARLY ACROSS INTERIOR WITH INCREASING CLOUD COVER AND
ARCTIC AIRMASS IN PLACE. WILL LEAN TOWARDS COLDER MET GUIDANCE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
SHORTWAVE ENERGY PIVOTS WELL NORTH OF THE REGION THIS EVENING...WITH
COLD FRONT PASSING TO THE EAST.
MODERATELY STRONG WINDS AND GUSTS SHOULD GRADUALLY WEAKEN THROUGH
THE OVERNIGHT AS HIGH PRESSURE BUILDS IN.
BAND OF STRATO-CU AND A FEW FLURRIES MAY LINGER ACROSS FAR NW ZONES
IN THE EVENING AT TAIL END OF LAKE STREAMERS...OTHERWISE
SKIES CLEAR IN WAKE OF THE FRONT THIS EVENING.
ZONAL UPPER FLOW ON WEDNESDAY AROUND POLAR VORTEX DRIFTING EAST
THROUGH CENTRAL QUEBEC...WITH ARCTIC HIGH PRESSURE BUILDS INTO
NORTHERN NEW ENGLAND. MOISTURE WILL LIKELY BE STREAMING EASTWARD ON
WEDNESDAY AS AN OVERRUNNING PATTERN DEVELOPS OVER THE ARCTIC
AIRMASS...BUT SOME UNCERTAINTY EXITS ON WHERE MAIN AXIS OF MOISTURE
WILL LIE. BUT OVERALL PATTERN SUGGEST INCREASING CLOUD COVER AND
POTENTIAL FOR LIGHT SNOW DEVELOPMENT ACROSS FAR NW ZONES TOWARDS
EVENING.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
POTENTIAL FOR A SIGNIFICANT COASTAL STORM LATE THIS
WEEK...FOLLOWED BY BITTERLY COLD TEMPERATURES...
00Z DETERMINISTIC MODELS HAVE COME INTO BETTER ALIGNMENT YIELDING
HIGHER CONFIDENCE FOR A SIGNIFICANT COASTAL STORM TO IMPACT THE AREA
LATE THIS WEEK. HOWEVER...WOULD LIKE TO SEE ANOTHER CONSISTENT SET
OF DATA BEFORE ISSUING ANY WATCHES.
H5 FLOW ACROSS THE CONUS BEGINS WITH RIDGING IN THE WEST...A DIGGING
TROUGH IN THE PLAINS AND ZONAL FLOW IN THE EAST. THE TROUGH WILL
AMPLIFY AS IT CONTINUES TO DEEPEN THU AND FRI AND MOVES TOWARDS THE
EASTERN SEABOARD.
AT THE SFC...A STALLED FRONTAL BOUNDARY WILL STRETCH FROM THE UPPER
MID WEST TO SOUTHERN NEW ENGLAND ON THU WITH A WEAK AREA OF LOW PRES
DEVELOPING ALONG IT. THE COMBINATION OF A 130 KT RRQ UPPER JET AND
INCREASING ISENTROPIC LIFT BETWEEN THE 275K TO 290K PLANES WILL
RESULT IN LIGHT PRECIPITATION TO DEVELOP ACROSS INTERIOR PORTIONS OF
THE LOWER HUDSON VALLEY AND SW CT WED EVE WITH CHANCES INCREASING
ACROSS THE ENTIRE AREA OVERNIGHT. TEMPS WILL BE COLD ENOUGH FOR SNOW
ALTHOUGH IT WILL BE LIGHT.
ATTENTION THEN TURNS TO CYCLOGENESIS OCCURRING OFF THE CAROLINA COAST
AS SHORTWAVE ENERGY WITHIN THE DIGGING UPPER TROUGH CONSOLIDATES
WITH SOUTHERN STREAM ENERGY OVER THE GULF OF MEXICO AND SOUTHEAST
STATES ON THU. THE LOW WILL DEEPEN AS IT TRACK NE THU NIGHT AND ALL
MODELS ARE INDICATING IT PASSES WELL OUTSIDE OF THE 40N 70W
BENCHMARK. HOWEVER...CONFIDENCE IS INCREASING FOR A SIGNIFICANT
SNOWFALL EVENT ACROSS THE ENTIRE AREA. THERE IS THE POTENTIAL THAT
SOUTHERN LONG ISLAND/NYC COULD SEE A MIX OR CHANGEOVER...BUT CURRENT
THINKING IS THAT IT REMAINS COLD ENOUGH FOR SNOW. HEAVIEST SNOWFALL
WILL BE THU NIGHT INTO FRI MORNING WHERE 4-6 INCHES COULD FALL. OF
COURSE AMOUNTS WILL BE HIGHER WHERE ANY MESOSCALE BANDS OCCUR...SO
CURRENT THINKING IS 5 TO 9 INCHES ACROSS THE ENTIRE CWA...HIGHEST
AMOUNTS ACROSS INTERIOR LOCATIONS.
IN ADDITION TO THE SNOW WILL BE STRONG NLY WINDS. AS THE STORM
DEEPENS THE GRADIENT WILL TIGHTEN WITH WINDS RANGING FROM 20 TO 30
MPH AND GUSTS BETWEEN 30 AND 45 MPH. THE STRONGEST WINDS WILL BE
ACROSS THE TWIN FORKS OF LONG ISLAND.
THE UPPER TROUGH AXIS PUSHES E OF THE AREA ON FRI WITH A DEEP NW
FLOW FLATTENING AND A RIDGE OF HIGH PRES MOVING ACROSS ON SAT. A
BITTERLY COLD AIRMASS...THE COLDEST OF THE SEASON...WILL THEN BE
UPON US FRI/FRI NIGHT. HIGHS WILL STRUGGLE TO GET OUT OF THE TEENS
EXCEPT PERHAPS IN NYC AND ON LONG ISLAND WHERE THEY WILL TOP OUT IN
THE LOWER 20S. FRI NIGHT WILL DROP INTO THE SINGLE DIGITS AT THE
COAST AND FALL BELOW ZERO INLAND. WIND CHILLS WILL BE IN THE SINGLE
DIGITS AT THE COAST TO A FEW DEGREES BELOW ZERO INLAND DURING THE
DAY AND GENERALLY FROM AROUND -2F TO -10F RESPECTIVELY FRI NIGHT.
FOCUS HAS BEEN ON THE UPCOMING STORM AND THEREFORE HAVE NOT MADE
MANY CHANGES TO THE REMAINDER OF THE FORECAST BEYOND FRI. THERE ARE
SIGNIFICANT DIFFERENCES IN THE GUIDANCE FOR EARLY NEXT WEEK AND FELT
IT WAS PRUDENT TO CONTINUE WITH PERSISTENCE ATTM. OVERALL...A
NORTHERN CANADIAN VORTEX WILL DROP INTO CENTRAL CANADA THIS WEEKEND
WITH A BROAD LONGWAVE TROUGH ENCOMPASSING THE LOWER 48 INTO EARLY
NEXT WEEK. THE EC BRINGS THIS VORTEX INTO THE GREAT LAKES REGION
BEFORE LIFTING IT BACK N WHILE THE GFS KEEPS IT NEAR HUDSON BAY.
THIS DIFFERENCES LEAD TO LARGE VARIATIONS IN OUR LOCAL WEATHER.
&&
.AVIATION /18Z TUESDAY THROUGH SUNDAY/...
LOW PRESSURE OVER THE EASTERN GREAT LAKES WILL MOVE EAST ACROSS
NORTHERN NEW ENGLAND AS ITS TRAILING FRONT MOVES EAST ACROSS THE
REGION THIS AFTERNOON. HIGH PRESSURE WILL FOLLOW THROUGH WEDNESDAY.
VFR WEATHER WILL PREVAIL OUTSIDE OF SNOW SHOWERS. THERE IS A CHC OF
MVFR CIGS AND VSBYS IN HEAVIER SNOW SHOWERS UNTIL 22Z. ALL UPDATED
TAFS INCLUDE SNOW SHOWERS IN VCNTY.
WINDS TODAY...SW 230-250 DEGS WILL INCREASE TO 15-20 KT AHEAD OF
APPROACHING FRONT THEN SHIFT FROM THE W 270-290 DEGS NEAR 20 KT WITH
GUSTS TO 30 KT MAINLY 21Z - 02Z.
WINDS TONIGHT...GUSTS WILL DISSIPATE BY MIDNIGHT...05Z AND
SUSTAINED W WINDS WILL DECREASE TO 10 KT OR LESS.
WINDS NEW YEARS DAY...W ARND 10 KT BECOMING SW DURING THE AFTN.
...NY METRO ENHANCED AVIATION WEATHER SUPPORT...
DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT: HTTP://WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)
KEWR FCSTER COMMENTS: CHC TEMPO CIGS 2000-3000FT AND REDUCED VSBYS
IN -SHSN FROM 18-22Z.
THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS GREEN...WHICH IMPLIES
SLANT RANGE VISIBILITY 7SM OR GREATER OUTSIDE OF CLOUD.
KJFK FCSTER COMMENTS: CHC TEMPO CIGS 2000-3000FT AND REDUCED VSBYS
IN -SHSN FROM 18-22Z.
KLGA FCSTER COMMENTS: CHC TEMPO CIGS 2000-3000FT AND REDUCED VSBYS
IN -SHSN FROM 18-22Z.
KTEB FCSTER COMMENTS: CHC TEMPO CIGS 2000-3000FT AND REDUCED VSBYS
IN -SHSN FROM 18-22Z.
KHPN FCSTER COMMENTS: CHC TEMPO OR PREVAILING CIGS 2000-3000FT AND
REDUCED VSBYS IN -SHSN FROM 18-22Z.
KISP FCSTER COMMENTS: CHC TEMPO OR PREVAILING CIGS 2000-3000FT AND
REDUCED VSBYS IN -SHSN FROM 20-23Z.
.OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
.WEDNESDAY...VFR.
.WEDNESDAY NIGHT...MVFR OR LOWER POSSIBLE LATE IF SNOW DEVELOPS. E
GUSTS AROUND 20 KT POSSIBLE LATE AS WELL.
.THURSDAY-FRIDAY...SNOW LIKELY WITH IFR AND LOWER CONDITIONS.
SIGNIFICANT ACCUMULATION POSSIBLE. GUSTS 30-40 KT POSSIBLE. WINDS
BACK FROM E-NE THURSDAY TO NW FRIDAY. SNOW ENDS FRIDAY MORNING. BCMG
VFR BY DAY`S END.
.FRIDAY NIGHT...VFR. NW GUSTS 20-30 KT DURING THE EVENING.
.SATURDAY AND EARLY SUNDAY...VFR. MVFR CIGS POSSIBLY DEVELOPING
SUNDAY AFTN AND EVENING.
&&
.MARINE...
FORECAST ON TRACK SEEING SOME INCREASE IN WINDS ACROSS THE WATERS
FOR EARLY THIS AFTERNOON.
WINDS THEN PICK UP TO SCA LEVELS LATE THIS AFTERNOON AND CONTINUE
THROUGH TONIGHT IN THE WAKE OF A COLD FRONTAL PASSAGE. A BRIEF
PERIOD OF GALE FORCE ARE POSSIBLE MAINLY BETWEEN 21Z-
03Z...PARTICULARLY ON THE OCEAN WATERS WITH AGREEMENT IN THE NAM
AND GFS BUFKIT PROFILES. SEAS LIKELY BUILD TO 6 TO 8 FT ON
EASTERN OCEAN IN RESPONSE TO STRONG WNW FLOW...WITH 5 FT SEAS ON
CENTRAL AND EASTERN SOUND.
SUB SCA WINDS LIKELY RETURN BY WED MORNING AS HIGH PRESSURE
BRIEFLY BUILDS OVER THE WATERS.
SUB-ADVSY CONDS WILL CONTINUE THROUGH WED NIGHT...BUT SCA CONDS WILL
RETURN ON THU ON ALL WATERS...WITH GALES BECOMING MORE LIKELY ON
MOST OF THE WATERS THU NIGHT AND FRI AS A COASTAL STORM PASSES TO
THE S AND E. CONDS IMPROVE FRI NIGHT...ALTHOUGH SCA CONDS WILL
LIKELY BE NEEDED WITH ADVSY LEVEL SEAS LINGERING ON THE OCEAN WATERS
INTO SAT MORNING. SUB-ADVSY CONDS ARE THEN EXPECTED THROUGH THE
REMAINDER OF THE FORECAST PERIOD WITH HIGH PRES BUILDING TOWARDS THE
AREA.
&&
.HYDROLOGY...
A COASTAL STORM IMPACTING THE AREA FROM WED NIGHT INTO FRI HAS THE
POTENTIAL TO PRODUCE BETWEEN 1/2 AND 1 INCH OF LIQUID EQUIVALENT
PRECIPITATION AMOUNT. CURRENTLY...IT APPEARS THAT ALL AREAS WILL
RECEIVE THIS IN SOLID FORM...THEREFORE NO HYDROLOGIC IMPACTS ARE
EXPECTED.
&&
.TIDES/COASTAL FLOODING...
INCREASING LIKELIHOOD FOR MINOR COASTAL FLOODING DURING THE THURSDAY
MORNING HIGH TIDE CYCLE WITH STRENGTHENING E/NE WINDS AND
ASTRONOMICALLY HIGH TIDES. POTENTIAL EXITS FOR LOW END MODERATE
COASTAL FLOODING ALONG WESTERN LONG ISLAND SOUND AND EASTERN
BAYS...AND POSSIBLY WESTERN GREAT SOUTH BAY. THE MODERATE COASTAL
FLOOD THREAT SHOULD BECOME CLEARER OVER THE NEXT 24 HOURS.
THU NIGHT HIGH TIDAL CYCLES IS LOWER OF THE TWO AND LATEST THINKING
IS THAT SOLID GALES WILL BE TURNING NORTH DURING THIS TIDAL
CYCLE...WHICH SHOULD LIMIT COASTAL FLOODING IMPACTS MAINLY TO MINOR.
NORTH FACING SHORELINES WOULD BE MOST VULNERABLE...AND IT SHOULD BE
NOTED THAT THESE NORTHERLY GALE EVENTS ARE KNOWN TO CAUSE MORE
SERIOUS COASTAL IMPACTS ALONG THE NORTH FACING PORTIONS OF THE TWIN
FORKS OF LONG ISLAND DUE TO COMBINED STORM TIDE AND WAVE ACTION.
WITH OFFSHORE GALES DEVELOPING FOR FRI MORNING HIGH TIDE
CYCLE...MINOR COASTAL FLOODING SHOULD BECOME MORE LOCALIZED...MAINLY
IN BACK BAY AREAS DUE TO LIMITED TIDAL DRAINAGE.
IN ADDITION...HIGH SURF OF 7 TO 10 FT WITH ENE TO WSW SWEEP LATE
THURSDAY INTO FRIDAY WILL LIKELY RESULT IN MINOR BEACH EROSION
ISSUES ALONG ATLANTIC OCEAN FACING BEACHES OF LONG ISLAND AND
PARTICULARLY THE SOUTH FORK OF LI.
SOME UNCERTAINTY STILL EXISTS IN THE TRACK AND TIMING OF THIS
COASTAL STORM WHICH WOULD CAUSE SOME MODIFICATION TO ABOVE
FORECAST...SO MONITOR SUBSEQUENT FORECAST FOR THE LATEST.
&&
.EQUIPMENT...
THE NEW YORK CITY NOAA ALL HAZARDS WEATHER RADIO STATION KWO35 IS
OUT OF SERVICE.
DUE TO INTERFERENCE ISSUES WITH THE U.S. COAST GUARD EMERGENCY
BROADCAST CHANNEL...THE NEW YORK CITY NOAA ALL HAZARDS WEATHER
RADIO STATION KWO35 IS OUT OF SERVICE.
DURING THE TIME...THE TRANSMITTER MAY BE RETURNED TO SERVICE
INTERMITTENTLY FOR USE OF THE NOAA ALL HAZARDS WEATHER RADIO
DURING POTENTIALLY DANGEROUS WEATHER SITUATIONS...FOR ROUTINE
WEEKLY TEST OF THE WARNING SYSTEM...AND TO DETERMINE IF THE
INTERFERENCE ISSUE HAS BEEN RESOLVED.
&&
.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST WEDNESDAY FOR ANZ330-335-
338-340-345-350-353-355.
&&
$$
SYNOPSIS...24/NV
NEAR TERM...JM/NV
SHORT TERM...NV
LONG TERM...24
AVIATION...GC
MARINE...24/JM/NV
HYDROLOGY...24/NV
TIDES/COASTAL FLOODING...
EQUIPMENT...
AREA FORECAST DISCUSSION
NWS MOUNT HOLLY NJ
623 PM EST WED JAN 1 2014
.SYNOPSIS...
AN ARCTIC COLD FRONT STRETCHED FROM NORTHERN NEW ENGLAND TO
THE OHIO VALLEY WILL MOVE SOUTHWARD TONIGHT. TWO LOW PRESSURE SYSTEMS
WILL DEVELOP BY THURSDAY, ONE ACROSS THE APPALACHIANS AND A
SECONDARY LOW OFF OF THE CAROLINA COAST. THESE WILL MERGE INTO ONE
LOW OFFSHORE ON FRIDAY AND INTENSIFY AS IT MOVES AWAY FROM OUR
REGION. ARCTIC HIGH PRESSURE WILL THEN BUILD IN FOR FRIDAY, BEFORE
MOVING OFFSHORE SATURDAY AND SUNDAY. BY LATER SUNDAY INTO MONDAY,
ANOTHER AREA OF LOW PRESSURE MAY IMPACT THE REGION FROM THE WEST.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
NO BIG CHANGES WITH THIS UPDATE. THE HRRR IS GENERATING SOME PCPN
OFF THE OCEAN, SO WE ARE KEEPING THE POPS FOR NOW FOR LATER THIS
EVENING. FNTL BOUNDARY APPROX KUNV TO KBOS WITH LIGHT SNOW NORTH
OF THE BOUNDARY.
TONIGHT...THE SPC WRF AND SOME OTHER MODELS ARE BREAKING OUT PCPN
FROM COASTAL NNJ THROUGH NW NJ. THIS SHALLOW WAA AT THE TOP OF THE
MOISTENING BOUNDARY LAYER SHOWS WEAK 3MB/SEC UVM PULSES NEAR 4000
FT. WHAT EVER HAPPENS TONIGHT IS RELATIVELY MINOR AND MOSTLY
CONFINED TO A CORRIDOR FROM NE NJ NWWD THRU FAR NNJ.
OTRW THE FCST IS A 50 50 BLEND OF THE 12Z GFS/NAM MOS AND WPC QPF
GUIDANCE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
THURSDAY...CONSIDERABLE DOUBT AS TO HOW MUCH SNOW CAN OCCUR ON
THURSDAY DURING THE DAY IN NE PA AND NNJ WITH A DRY SLOT ALOFT
ROUGHLY BETWEEN 850-700MB MINIMIZING THE LOW LVL ESE INFLOW WAA
PATTERN. SO DESPITE THE WARNING FOR AFTN THURSDAY NEAR AND N OF
80...AM NOT YET CONVINCED HOW MUCH WILL OCCUR.
S NJ AND THE DELMARVA...MAYBE SOME SUNSHINE IN THE MORNING AND TEMPS
RISING TO 40-45F WITH NO PCPN EXPECTED.
STRENGTHENING NE WIND DRIVES A SHIELD OF LOW CLOUDS SWWD DURING
MIDDAY INTO S NJ AND SE PA.
12Z/2 50 50 BLENDED NCEP MOS GUIDANCE BLENDED WITH A SMALL PERCENTAGE
OF 12 NAM RAW 2M TEMPS AND 10M WINDS.
THURSDAY NIGHT...THE EVENT. WE`VE LET THE BOX SNOW TOOL DRIVE THE
AMOUNTS WITH LARGE SNOW WATER RATIOS. COMBINATION OF ONCOMING SHORT
WAVE AND THE ARCTIC FRONT SIFTING SOUTHWARD INCREASES FGEN AND
PROBABLE PERIOD OF 1/4 TO 1/2 MI MDT TO HEAVY SNOW. THE WATCH
INCORPORATED 12Z WPC QPF GUIDANCE. ITS A WATCH AND PUBLIC IMPACT MAY
BE SUBSTANTIAL DUE TO THE INFUSION OF BITTERLY COLD NW WIND GUSTS 30
TO 45 MPH WITH SUBZERO WIND CHILL AT DAYBREAK FRIDAY...DESPITE THE
SNOW TAPERING TO FLURRIES BETWEEN 6AM AND 10 AM.
AS YOU KNOW...THE MORE RELIABLE MODELS ARE SLOWLY CONVERGING ON
QPF WITH THE 12Z/2 EC HAVING MARKEDLY INCREASED QPF IN NJ.
THERE IS A SMALL CHC WE MAY EVENTUALLY NEED TO CONSIDER A BLIZZARD
WARNING FOR MONMOUTH AND OCEAN COUNTIES BUT FOR NOW...ITS ONLY A 20
PCT CHANCE IN OUR MINDS.
LETS JUST FOCUS ON VERY SLIPPERY TRAVEL THURSDAY NIGHT WITH
BITTERLY COLD WIND CHILL TO FOLLOW FRIDAY MORNING.
WHERE ITS WELL ABOVE FREEZING THURSDAY SOUTHERN NJ AND THE
DELMARVA... THE COMBINATION OF SNOW AND RAPIDLY FALLING TEMPS IS
GOING TO DEVELOP TREACHEROUS TRAVEL CONDITIONS BETWEEN 7PM AND
MIDNIGHT. THIS TRANSITION TO ICY ROADS MAY FORECAST 3 HOURS TOO
FAST AND WILL NEED REFINEMENT IN FUTURE FCSTS. IF I HAD TO DO IT
AGAIN...I`D DELAY THE TRANSITION TO SNOW IN SE NJ-DELMARVA A FEW
HOURS FROM WHAT WE HAVE FCST AT 330 PM.
FLUFFY DRY SNOW LATE AT NIGHT WILL BE BLOWING AND DRIFTING.
THE WARNING ISSUANCE IS WHERE WE ARE CONFIDENT FOR COMBINED PUBLIC
IMPACT AND SNOW FALL.
THE WATCH WAS ISSUED WHERE WE ARE CONFIDENT OF AT LEAST ADVY CONDITIONS
THURSDAY NIGHT AND EARLY FRI BUT UNSURE WHETHER WE CAN EXCEED 4 INCHES.
THE MID SHIFT CAN RESOLVE THIS UNCERTAINTY.
ADDITIONALLY...WE ANTICIPATE THE NEED FOR ADVISORIES FOR SNOW ON THE
DELMARVA LATE THURSDAY NIGHT BUT THAT CAN BE ADDRESSED THURSDAY.
PLEASE MONITOR FUTURE PRODUCT ISSUANCES.
&&
.LONG TERM /FRIDAY THROUGH WEDNESDAY/...
THE AFOREMENTIONED LOW PRESSURE SYSTEM WILL BE DEPARTING EARLY THU
BUT THERE COULD BE LINGERING SNOW FOR AT LEAST THE MORNING HOURS,
ESPECIALLY OVER NERN AREAS. INTENSITY AND AMOUNTS SHOULD BE LIGHT,
WITH MOST, IF NOT ALL PRECIP OVER BY LATE MORNING, EARLY AFTN.
THEN, A VERY LARGE AREA OF HIGH PRESSURE BUILD IN AND WE ARE IN
FOR THE COLDEST AIR OF THE SEASON. HIGH TEMPS WILL NOT GET OUT OF
THE TEENS IN MOST LOCATIONS AND WITH THE A GUSTY NW WIND IN THE
20-30 MPH RANGE, WIND CHILL TEMPS WILL BE AOB ZERO. THE GOOD NEWS,
IF THERE IS ANY WILL BE DRY. FRI NIGHT WILL BE VERY COLD AS WELL,
ESPECIALLY WITH THE NEW SNOW COVER. TEMPS WILL BEING THE SINGLE
DIGITS AND BELOW ZERO.
SAT INTO EARLY SUN WILL BE DRY AND A BIT WARMER AS THE HIGH MOVES
EWD.
BY LATER SUN, THE MDLS HAVE SOME DISAGREEMENT WITH THE NEXT SYS.
AN AREA OF LOW PRESSURE WILL EJECT OUT OF THE GLFMEX AND MOVE NEWD
INTO THE OH VLY SUN NIGHT. THE GFS IS MUCH MORE PROGRESSIVE WITH
THIS SYS THAN THE OTHER MDLS AND BRINGS THE LOW THRU LATE SUN
NIGHT AND INTO NEW ENG MON MRNG FOLLOWED BY A STRONG CDFNT AND
ANOTHER HUGE ARCTIC HIGH FROM CANADA. IT KEEPS MOST OF MON AND TUE
COLD AND DRY.
THE ECMWF HAS A MUCH SLOWER AND STRONGER SYS. IT BRINGS THE LOW
AND CDFNT THRU DURG THE DAY ON MON, BUT AS A RESULT, AT LEAST
LATER SUN INTO THE FIRST HALF OF MON IS QUITE WET. IT THEN BRINGS
THE STRONG HIGH IN FOR TUE AND WED. THE CMC IS IN THE MIDDLE OF
THE TWO SOLNS BUT A TAD MORE AMPLIFIED THAN THE GFS AND THE UKMET
IS SUPPORTIVE OF THE SLOWER AND STRONGER SOLN AS WELL. SO FOR NOW
WILL TREND TWD THE ECMWF SOLN. TEMPS LOOK TO BE WARM ENOUGH WITH
THIS NEXT SYS FOR A PREDOMINANTLY RAIN EVENT AFTER SOME ERLY MRNG
MIXED PRECIP.
TEMPS ARE ON A CLASSIC ROLLER COASTER RIDE THRU THE PD. SOME OF
THE COLDEST WX OF THE SEASON WILL BE OVER THE REGION ON FRI. A
WARM UP WILL THEN OCCUR ON FRI AND AN EVEN BIGGER ONE ON SUN AND
INTO MON. THEN TEMPS WILL CRASH AGAIN BEHIND THE SECOND FRONT INTO
TUE. HAVE GONE BELOW GUID SAT AND A TAD BELOW ON SUN DUE TO THE
UNCERTAINTY WITH THE LOW AND THE SNOW COVER, BUT STILL SHUD SEE A
WARMING TREND.
&&
.AVIATION /23Z WEDNESDAY THROUGH MONDAY/...
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG, KILG,
KMIV, KACY AND SURROUNDING AREAS.
THE 00Z TAFS HAVE VFR CONDITIONS FOR THIS EVENING WITH A MID LEVEL
CIG EXPECTED TO PREVAIL NORTHERN TERMINALS AND OR DEVELOP AT
SOUTHERN TERMINALS. WINDS WILL BE LIGHT FROM THE EAST TO
NORTHEAST.
OVERNIGHT A MVFR CIG WITH POSSIBLY SOME MVFR VSBYS (AT THE MORE
RURAL TERMINALS) ARE FORECAST TO DEVELOP NORTH OF THE PHILADELPHIA
AIRPORTS. WINDS WILL REMAIN LIGHT FROM THE NORTHEAST TO EAST.
ON THURSDAY MORNING WE ARE EXPECTING VFR STRATOCU LEVEL CIGS TO
PREVAIL, EVEN AT NORTHERN AIRPORTS. WINDS SHOULD BE MORE FROM THE
NORTHEAST AT 5 TO 10 KTS.
ON THURSDAY AFTERNOON/EARLY EVENING PRECIPITATION IS FORECAST TO
DEVELOP AND MOVE IN. FROM AROUND KPHL AND TERMINALS SOUTHEAST
RAIN, POSSIBLY MIXED WITH SNOW, WHICH SHOULD KEEP VSBYS AND CIGS
AT MVFR. FARTHER NORTH, ALL SNOW IS FORECAST AND WE BRING THE
TERMINALS TO IFR. IN THE 30HR KPHL TAF, WE CHANGE THE MIXED TO ALL
SNOW QUICKLY THURSDAY EVENING AND BRING IFR CONDITIONS.
OUTLOOK...
THURSDAY NIGHT...IFR OR LIFR CONDITIONS DEVELOP IN SNOW EXCEPT
RAIN CHANGE TO SNOW VCNTY KMIV KACY KILG. NORTH WINDS INCREASE
WITH GUSTS 25 TO 35 KT LATE. BLOWING AND DRIFTING SNOW LATE AS
TEMPS PLUMMET INTO THE TEENS. PLOWING ANTICIPATED MOST TAF SITES.
FRI...AFTER SOME ERLY LINGERING SNOW, ESPECIALLY N AND E, CONDS
WILL IMPROVE TO VFR. STRONG NORTHWEST WINDS GUSTING 25-30 KT.
HIGH CONFIDENCE.
FRI NIGHT THROUGH SAT NIGHT...VFR. HIGH PRESSURE. HIGH CONFIDENCE
SUN THROUGH MON...POSSIBLE MVFR WITH LIGHT RAIN AND SNOW EARLY SUN
THEN BECOMING ALL RAIN. POSSIBLE IFR AT NIGHT WITH HEAVIER RAIN.
STILL SOME QUESTIONS WRT TRACK, STRENGTH OF TIMING OF SYS. LOW TO
MDT CONFIDENCE.
&&
.MARINE...
TONIGHT...SUB-ADVISORY LIGHT WINDS.
THURSDAY...WHILE SCA CONDITIONS ARE EXPECTED TO DEVELOP WITH
STRENGTHENING LOW PRESSURE TRACKING CLOSER TO THE REGION WE ISSUED A
GLW LATE IN THE DAY FOR THE NNJ WATERS.
THURSDAY NIGHT...GLW COND DEVELOP ALL WATERS BY 06Z FRIDAY. NLY
GUSTS TO 45 KT POSSIBLE LATE THURSDAY NIGHT. FREEZING SPRAY
DEVELOPS LATE AT NIGHT ALL WATERS.
OUTLOOK...
FRI...GALE FORCE WIND GUSTS ARE LIKELY ALONG WITH INCREASING
SEAS. LIGHT FREEZING SPRAY IS ALSO EXPECTED... ESPECIALLY THE
NORTHERN NEW JERSEY WATERS FRIDAY MORNING. GALE WARNING HAS BEEN
EXTENDED THRU 00Z.
FRI...SCA CONDITIONS ARE EXPECTED ARE EXPECTED ON THE BACK END OF
THE GALE.
SAT AND SUN...SUB-ADVISORY CONDITIONS ARE EXPECTED.
&&
.TIDES/COASTAL FLOODING...
CFA ISSUED FOR FRIDAY...THE PRIMARY RISK DATE. ANY COASTAL FLOODING
WITH THE THURSDAY MORNING HIGH TIDE WILL BE MINOR AT WORST AND
PALE IN COMPARISON TO FRIDAY MORNING.
LOW PRESSURE IS EXPECTED TO EXPLOSIVELY STRENGTHEN (1 TO 2MB/HOUR
THURSDAY NIGHT) AS IT TRACKS NORTHEAST OFF THE EASTERN SEABOARD
THURSDAY INTO FRIDAY. THIS LOW, IN CONJUNCTION WITH THE NEW MOON
HAVING JUST OCCURRED ON WEDNESDAY WILL LEAD TO AN INCREASE IN
TOTAL TIDE LEVELS. THE THURSDAY MORNING AND FRIDAY MORNING HIGH
TIDE CYCLES WILL CONTINUE TO BE MONITORED. MINOR TIDAL FLOODING
MAY BE APPROACHED WITH THE THURSDAY MORNING HIGH TIDE FROM SANDY
HOOK TO CAPE MAY AND ALSO AT LEWES, DELAWARE. THE FRIDAY MORNING
HIGH TIDE CYCLE IS OF MUCH GREATER CONCERN AS CURRENT GUIDANCE
INDICATES THE POTENTIAL FOR SOLID MODERATE COASTAL FLOODING IN NNJ
AND MARGINAL MODERATE FURTHER SOUTH. THE NORTHERN COAST OF NJ
HAVING THE HIGHEST DEPARTURES, INCLUDING THE COASTS OF MONMOUTH
AND OCEAN COUNTIES INTO RARITAN BAY MAY SEE MARGINALLY MAJOR FLOODING.
IN ADDITION, LOWER DELAWARE BAY WOULD ALSO BE AT RISK FOR MODERATE
COASTAL FLOODING WITH THE FRIDAY MORNING HIGH TIDE BUT WE THINK
MORE SO ON THE DELAWARE SIDE OF THE BAY DUE TO THE STRONG NNW WIND
EXPECTED AT THE TIME OF THE FRIDAY MORNING HIGH TIDE.
ELSEWHERE, TIDAL FLOODING IS NOT EXPECTED AT THIS TIME
INTO THE TIDAL DELAWARE RIVER OR ALONG THE EASTERN SHORE OF
CHESAPEAKE BAY, BUT MODEL GUIDANCE WILL CONTINUE TO BE MONITORED.
&&
.CLIMATE...
FOR A PERSPECTIVE AT THIS FORECAST JUNCTURE...
THE COLD TEMPERATURES FORECAST SATURDAY MORNING WILL BE THE
COLDEST AT LEAST DATING BACK AS FOLLOWS:
OUR LATEST FORECAST FOR SATURDAY MORNING JANUARY 4, 2014:
KILG AROUND 7F. LAST TIME WAS 1/16-17/2009 AT 7 AND 5 RESPECTIVELY.
KPHL AROUND 7F. LAST TIME WAS JAN 17, 2009.
KABE AROUND 0F. LAST TIME THIS COLD WAS JAN 24, 2011.
FOR THOSE LOOKING AT RECORDS WITH A PROBABLE FRESH SNOW COVER TO
ASSIST MAGNIFYING THE INCOMING LATE WEEK COLD AIRMASS...
1/3 1/4
KACY...-2 1879 0 1918 POR 1874
KPHL...-3 1879 2 1918 POR 1872
KILG...+4 1918 -1 1918 POR 1894
KABE...+6 1945 -4 1981 POR 1922
KTTN...-4 1879 -1 1918 POR 1865
KGED...+8 1962 4 1979 POR 1948
KRDG...+1 1918 -5 1981 POR 1869
KMPO...-7 1904 -23 1981 POR 1901
POR = PERIOD OF RECORD.
&&
.PHI WATCHES/WARNINGS/ADVISORIES...
PA...WINTER STORM WARNING FROM 1 PM THURSDAY TO 10 AM EST FRIDAY
FOR PAZ054-055-061-062.
WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY
MORNING FOR PAZ060-070-071-101>106.
NJ...WINTER STORM WARNING FROM 1 PM THURSDAY TO 10 AM EST FRIDAY
FOR NJZ001-007-008.
WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY
MORNING FOR NJZ009-010-012>022-025>027.
COASTAL FLOOD WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON FOR NJZ012>014-020>027.
DE...WINTER STORM WATCH FROM THURSDAY EVENING THROUGH FRIDAY
MORNING FOR DEZ001.
COASTAL FLOOD WATCH FROM LATE THURSDAY NIGHT THROUGH FRIDAY
AFTERNOON FOR DEZ002>004.
MD...NONE.
MARINE...GALE WARNING FROM 1 AM TO 7 PM EST FRIDAY FOR ANZ430-431-
452>455.
GALE WARNING FROM 4 PM THURSDAY TO 7 PM EST FRIDAY FOR ANZ450-
451.
&&
$$
SYNOPSIS...NIERENBERG
NEAR TERM...DRAG
SHORT TERM...DRAG
LONG TERM...NIERENBERG
AVIATION...DRAG/NIERENBERG
MARINE...DRAG/NIERENBERG
TIDES/COASTAL FLOODING...
CLIMATE...DRAG
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1047 PM EST WED JAN 1 2014
.SYNOPSIS...
A DEVELOPING LOW PRESSURE SYSTEM WILL BRING RAIN TO THE REGION
TONIGHT AND THURSDAY. A COLD FRONT WILL CROSS THE REGION THURSDAY
NIGHT WITH COLD DRY CANADIAN HIGH PRESSURE RETURNING FRIDAY AND
SATURDAY. THE NEXT SYSTEM IS EXPECTED TO BRING SHOWERS BACK INTO
THE REGION LATE SATURDAY NIGHT THROUGH EARLY MONDAY... FOLLOWED BY
COLD HIGH PRESSURE BUILDING IN THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
UPDATE...WSR-88D NETWORK SHOWS RAIN INCREASING FROM EASTERN GA INTO
THE CSRA AND SOUTHERN MIDLANDS. SURFACE OBSERVATIONS REPORTING
RAIN INDICATE INTENSITY IS VERY LIGHT WITH ONLY A HUNDREDTH OR TWO
PER HOUR. RAIN COVERAGE WILL CONTINUE EXPANDING NORTHWARD
OVERNIGHT WITH LIKELY POPS IN THE NORTHERN MIDLANDS BY DAYBREAK.
OVERNIGHT LOWS REMAIN ON TRACK FOR LOWER 40S MOST AREAS AND MID 40
IN THE EASTERN MIDLANDS.
PREVIOUS DISCUSSION...IR SATELLITE IMAGERY SHOWS EXTENSIVE
CLOUDINESS ACROSS THE SOUTHEAST WITH AREA WSR-88D NETWORK SHOWING
LIGHT RAIN ACROSS CENTRAL SC AND GA WITH A HEAVIER BAND ALONG THE
COAST. OVERNIGHT LOW PRESSURE WILL EJECT FROM THE SOUTHERN PLAINS
AND TRACK NORTHEASTWARD PUSHING GULF MOISTURE BACK INTO THE
FORECAST AREA. EXPECT THE RAIN SHOWERS TO INCREASE IN COVERAGE
OVERNIGHT WITH MOST OF THE AREA SEEING RAIN BY DAYBREAK. WITH PWAT
VALUES CURRENTLY AROUND ONE INCH FOR THE NEXT SEVERAL HOURS
RAINFALL AMOUNTS WILL GENERALLY BE UNDER ONE QUARTER INCH THROUGH
DAYBREAK...WITH SLIGHTLY HIGHER AMOUNTS POSSIBLE IN THE FAR
EASTERN MIDLANDS AND SOUTHERN CSRA. TEMPERATURES HAVE ALREADY
FALLEN INTO THE MID 40S AT MOST LOCATIONS AND WILL BOTTOM OUT IN
THE LOWER 40S FOR MOST AREAS WITH MID 40S IN THE EASTERN MIDLANDS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
A FULL LATITUDE TROUGH WILL CROSS THE FORECAST AREA THURSDAY AND
THURSDAY NIGHT. ISENTROPIC LIFT WILL BE ONGOING THURSDAY MORNING
ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA AND THIS WILL
SPREAD NORTHWESTWARD THROUGH THE MORNING INTO EARLY AFTERNOON
HOURS. PRECIPITABLE WATER VALUES WILL NOT BE AS HIGH AS THE PAST
COUPLE OF EVENTS BUT WILL SHOW A GRADIENT FROM AROUND AN INCH IN
THE NORTHWEST COUNTIES TO AROUND 1.3 INCHES IN THE SOUTHEASTERN
COUNTIES AND THE REGION WILL FALL WITHIN THE RIGHT ENTRANCE REGION
OF A 150 KT UPPER JET FURTHER SUPPORTING WIDESPREAD OMEGA OVER THE
REGION.
HAVE INCREASED POPS THURSDAY TO CATEGORICAL FOR ALL BUT THE WESTERN
MIDLANDS WHERE HIGH LIKELY POPS WILL BE HELD. LITTLE TO NO
INSTABILITY SO DO NOT EXPECT ANY THUNDER WITH THIS EVENT. QPF
AMOUNTS WILL BE LIMITED BY MODEST PRECIPITABLE WATER VALUES AND THE
SPEED OF THE SYSTEM. GENERALLY EXPECT AMOUNTS TO RANGE FROM A
QUARTER TO HALF INCH ACROSS THE WESTERN HALF OF THE FORECAST AREA
WITH A HALF TO THREE QUARTERS OF AN INCH POSSIBLE IN THE EAST.
THE TROUGH WILL BE QUICK TO MOVE THROUGH THE REGION AS SURFACE LOW
PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST BY THURSDAY EVENING
DRAWING AN ARCTIC COLD FRONT ACROSS THE FORECAST AREA THURSDAY
EVENING. RAIN SHOULD COME TO AN END QUICKLY FROM WEST TO EAST
THURSDAY EVENING WHILE STRONG COLD ADVECTION TAKES PLACE THROUGH
FRIDAY IN THE WAKE OF THE FRONT...WITH 850MB TEMPERATURES FALLING INTO
THE -5C TO -10C RANGE FRIDAY. WINDS WILL BE STRONG THURSDAY NIGHT
INTO FRIDAY MORNING. RIGHT NOW HAVE SUSTAINED WINDS IN THE 15 TO
20 MPH RANGE WITH GUSTS UP TO 30 MPH. WILL HOLD OFF ON LAKE WIND
ADVISORY UNTIL MID SHIFT TONIGHT OR MORNING UPDATE THURSDAY.
TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL IN THE 50S WITH
PRECIPITATION THURSDAY THEN FALL WELL BELOW NORMAL BY FRIDAY WITH
HIGHS STRUGGLING THROUGH THE LOWER TO MID 40S FRIDAY AND THEN A
COLD NIGHT FRIDAY NIGHT UNDER REASONABLE RADIATIONAL COOLING WITH
A VERY DRY AIR MASS IN PLACE WITH LOWS IN THE LOWER 20S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LATEST WPC GUIDANCE TRENDS TOWARD THE ECMWF WHICH IS MORE
AGGRESSIVE WITH RAIN CHANCES SAT NIGHT INTO SUNDAY NIGHT WITH THE
PASSAGE OF THE NEXT ARCTIC FRONT. EXISTING FORECAST WAS DRIER AND I
HAVE STARTED TRENDING TOWARD THE WPC GUIDANCE AS THE ECMWF HAS
GENERALLY PERFORMED BETTER FOR OUR AREA WITH PRECIP OVER THE PAST
WEEK OR TWO...ESPECIALLY IN THE LONGER TERM RANGES.
COLD HIGH PRESSURE BEGINS TO MOVE EAST OF THE AREA ON SATURDAY
BRINGING A RETURN FLOW WITH INCREASING MOISTURE. HIGHS WILL
CONTINUE BELOW NORMAL IN THE 40S. YET ANOTHER TROUGH WILL DIG
ACROSS THE MIDDLE PART OF THE COUNTRY SATURDAY NIGHT AND SUNDAY
INDUCING SURFACE LOW PRESSURE DEVELOPMENT OVER THE OHIO VALLEY ON
SUNDAY. ECMWF HAS DEEP POLAR VORTEX DROPPING INTO THE GREAT LAKES
REGION. AS SURFACE LOW MOVES NORTHEAST THE NEXT COLD/ARCTIC FRONT
WILL CROSS THE REGION.
WILL INCREASE POP INTO THE 40 TO 50 PERCENT RANGE SUNDAY. BEST
CHANCES FOR RAIN APPEARS TO BE SUNDAY NIGHT AND WILL RAISE POPS
INTO THE 50 TO 65 PERCENT RANGE. A VERY COLD ARCTIC AIR MASS WILL
BUILD OVER THE AREA BEHIND THE FRONT WITH STRONG COLD ADVECTION
MONDAY AND MONDAY NIGHT.
AHEAD OF THE FRONT SUNDAY...HIGH TEMPERATURES WILL MODERATE INTO
THE UPPER 50S AND LOWER 60S. THE COLD DRY AIR DOES NOT ARRIVE IN
EARNEST UNTIL MONDAY NIGHT WHEN TEMPERATURES WILL FALL INTO THE
MID 20S. HIGHS TUESDAY WILL STRUGGLE TO AROUND 40 DEGREES. WITH
HIGH PRESSURE OVER THE AREA TUESDAY NIGHT TEMPERATURES WILL FALL
TO AROUND 20 WITH HIGHS ON WEDNESDAY WARMING ONLY INTO THE LOWER
TO MID 40S.
&&
.AVIATION /04Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE ALONG THE COAST WILL BRING INCREASING MOISTURE.
WIDESPREAD RAIN WITH LOWERING CEILINGS AND VISIBILITIES WILL OCCUR.
IFR CONDITIONS WILL DEVELOP. THE 00Z HRRR AND GFS LAMP SHOWED VFR
OR MVFR CONDITIONS THROUGH 08Z. THE HRRR INDICATED IFR CONDITIONS
DEVELOPING BETWEEN 10Z AND 12Z. THE GFS LAMP WAS A LITTLE FASTER
WITH THE TIMING. LEANED TOWARD THE LAMP GUIDANCE AND FORECASTED IFR
BEGINNING 08Z TO 10Z. IT WILL BECOME BREEZY TOWARD THE END OF THE TAF
PERIOD BEHIND A STRONG COLD FRONT. THE GFS LAMP SUPPORTED GUSTS
AROUND 20 KNOTS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR LOWER CONDITIONS
MAY LINGER INTO THURSDAY EVENING AS LOW PRESSURE DEEPENS OFF THE
NORTH CAROLINA AND VIRGINIA COAST. A STRONG COLD FRONT WILL CROSS
THE AREA THURSDAY EVENING WITH CLEARING SKIES AND BREEZY
CONDITIONS IN ITS WAKE. ANOTHER LOW PRESSURE SYSTEM MAY BRING
FLIGHT RESTRICTIONS SATURDAY NIGHT AND SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
1018 PM EST WED JAN 1 2014
.SYNOPSIS...
A DEVELOPING LOW PRESSURE SYSTEM WILL BRING RAIN TO THE REGION
TONIGHT AND THURSDAY. A COLD FRONT WILL CROSS THE REGION THURSDAY
NIGHT WITH COLD DRY CANADIAN HIGH PRESSURE RETURNING FRIDAY AND
SATURDAY. THE NEXT SYSTEM IS EXPECTED TO BRING SHOWERS BACK INTO
THE REGION LATE SATURDAY NIGHT THROUGH EARLY MONDAY... FOLLOWED BY
COLD HIGH PRESSURE BUILDING IN THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
IR SATELLITE IMAGERY SHOWS EXTENSIVE CLOUDINESS ACROSS THE
SOUTHEAST WITH AREA WSR-88D NETWORK SHOWING LIGHT RAIN ACROSS
CENTRAL SC AND GA WITH A HEAVIER BAND ALONG THE COAST. OVERNIGHT
LOW PRESSURE WILL EJECT FROM THE SOUTHERN PLAINS AND TRACK
NORTHEASTWARD PUSHING GULF MOISTURE BACK INTO THE FORECAST AREA.
EXPECT THE RAIN SHOWERS TO INCREASE IN COVERAGE OVERNIGHT WITH
MOST OF THE AREA SEEING RAIN BY DAYBREAK. WITH PWAT VALUES
CURRENTLY AROUND ONE INCH FOR THE NEXT SEVERAL HOURS RAINFALL
AMOUNTS WILL GENERALLY BE UNDER ONE QUARTER INCH THROUGH
DAYBREAK...WITH SLIGHTLY HIGHER AMOUNTS POSSIBLE IN THE FAR
EASTERN MIDLANDS AND SOUTHERN CSRA. TEMPERATURES HAVE ALREADY
FALLEN INTO THE MID 40S AT MOST LOCATIONS AND WILL BOTTOM OUT IN
THE LOWER 40S FOR MOST AREAS WITH MID 40S IN THE EASTERN MIDLANDS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
A FULL LATITUDE TROUGH WILL CROSS THE FORECAST AREA THURSDAY AND
THURSDAY NIGHT. ISENTROPIC LIFT WILL BE ONGOING THURSDAY MORNING
ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA AND THIS WILL
SPREAD NORTHWESTWARD THROUGH THE MORNING INTO EARLY AFTERNOON
HOURS. PRECIPITABLE WATER VALUES WILL NOT BE AS HIGH AS THE PAST
COUPLE OF EVENTS BUT WILL SHOW A GRADIENT FROM AROUND AN INCH IN
THE NORTHWEST COUNTIES TO AROUND 1.3 INCHES IN THE SOUTHEASTERN
COUNTIES AND THE REGION WILL FALL WITHIN THE RIGHT ENTRANCE REGION
OF A 150 KT UPPER JET FURTHER SUPPORTING WIDESPREAD OMEGA OVER THE
REGION.
HAVE INCREASED POPS THURSDAY TO CATEGORICAL FOR ALL BUT THE WESTERN
MIDLANDS WHERE HIGH LIKELY POPS WILL BE HELD. LITTLE TO NO
INSTABILITY SO DO NOT EXPECT ANY THUNDER WITH THIS EVENT. QPF
AMOUNTS WILL BE LIMITED BY MODEST PRECIPITABLE WATER VALUES AND THE
SPEED OF THE SYSTEM. GENERALLY EXPECT AMOUNTS TO RANGE FROM A
QUARTER TO HALF INCH ACROSS THE WESTERN HALF OF THE FORECAST AREA
WITH A HALF TO THREE QUARTERS OF AN INCH POSSIBLE IN THE EAST.
THE TROUGH WILL BE QUICK TO MOVE THROUGH THE REGION AS SURFACE LOW
PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST BY THURSDAY EVENING
DRAWING AN ARCTIC COLD FRONT ACROSS THE FORECAST AREA THURSDAY
EVENING. RAIN SHOULD COME TO AN END QUICKLY FROM WEST TO EAST
THURSDAY EVENING WHILE STRONG COLD ADVECTION TAKES PLACE THROUGH
FRIDAY IN THE WAKE OF THE FRONT...WITH 850MB TEMPERATURES FALLING INTO
THE -5C TO -10C RANGE FRIDAY. WINDS WILL BE STRONG THURSDAY NIGHT
INTO FRIDAY MORNING. RIGHT NOW HAVE SUSTAINED WINDS IN THE 15 TO
20 MPH RANGE WITH GUSTS UP TO 30 MPH. WILL HOLD OFF ON LAKE WIND
ADVISORY UNTIL MID SHIFT TONIGHT OR MORNING UPDATE THURSDAY.
TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL IN THE 50S WITH
PRECIPITATION THURSDAY THEN FALL WELL BELOW NORMAL BY FRIDAY WITH
HIGHS STRUGGLING THROUGH THE LOWER TO MID 40S FRIDAY AND THEN A
COLD NIGHT FRIDAY NIGHT UNDER REASONABLE RADIATIONAL COOLING WITH
A VERY DRY AIR MASS IN PLACE WITH LOWS IN THE LOWER 20S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LATEST WPC GUIDANCE TRENDS TOWARD THE ECMWF WHICH IS MORE
AGGRESSIVE WITH RAIN CHANCES SAT NIGHT INTO SUNDAY NIGHT WITH THE
PASSAGE OF THE NEXT ARCTIC FRONT. EXISTING FORECAST WAS DRIER AND I
HAVE STARTED TRENDING TOWARD THE WPC GUIDANCE AS THE ECMWF HAS
GENERALLY PERFORMED BETTER FOR OUR AREA WITH PRECIP OVER THE PAST
WEEK OR TWO...ESPECIALLY IN THE LONGER TERM RANGES.
COLD HIGH PRESSURE BEGINS TO MOVE EAST OF THE AREA ON SATURDAY
BRINGING A RETURN FLOW WITH INCREASING MOISTURE. HIGHS WILL
CONTINUE BELOW NORMAL IN THE 40S. YET ANOTHER TROUGH WILL DIG
ACROSS THE MIDDLE PART OF THE COUNTRY SATURDAY NIGHT AND SUNDAY
INDUCING SURFACE LOW PRESSURE DEVELOPMENT OVER THE OHIO VALLEY ON
SUNDAY. ECMWF HAS DEEP POLAR VORTEX DROPPING INTO THE GREAT LAKES
REGION. AS SURFACE LOW MOVES NORTHEAST THE NEXT COLD/ARCTIC FRONT
WILL CROSS THE REGION.
WILL INCREASE POP INTO THE 40 TO 50 PERCENT RANGE SUNDAY. BEST
CHANCES FOR RAIN APPEARS TO BE SUNDAY NIGHT AND WILL RAISE POPS
INTO THE 50 TO 65 PERCENT RANGE. A VERY COLD ARCTIC AIR MASS WILL
BUILD OVER THE AREA BEHIND THE FRONT WITH STRONG COLD ADVECTION
MONDAY AND MONDAY NIGHT.
AHEAD OF THE FRONT SUNDAY...HIGH TEMPERATURES WILL MODERATE INTO
THE UPPER 50S AND LOWER 60S. THE COLD DRY AIR DOES NOT ARRIVE IN
EARNEST UNTIL MONDAY NIGHT WHEN TEMPERATURES WILL FALL INTO THE
MID 20S. HIGHS TUESDAY WILL STRUGGLE TO AROUND 40 DEGREES. WITH
HIGH PRESSURE OVER THE AREA TUESDAY NIGHT TEMPERATURES WILL FALL
TO AROUND 20 WITH HIGHS ON WEDNESDAY WARMING ONLY INTO THE LOWER
TO MID 40S.
&&
.AVIATION /03Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE ALONG THE COAST WILL BRING INCREASING MOISTURE.
WIDESPREAD RAIN WITH LOWERING CEILINGS AND VISIBILITIES WILL OCCUR.
IFR CONDITIONS WILL DEVELOP. THE 00Z HRRR AND GFS LAMP SHOWED VFR
OR MVFR CONDITIONS THROUGH 08Z. THE HRRR INDICATED IFR CONDITIONS
DEVELOPING BETWEEN 10Z AND 12Z. THE GFS LAMP WAS A LITTLE FASTER
WITH THE TIMING. LEANED TOWARD THE LAMP GUIDANCE AND FORECASTED IFR
BEGINNING 08Z TO 10Z. IT WILL BECOME BREEZY TOWARD THE END OF THE TAF
PERIOD BEHIND A STRONG COLD FRONT. THE GFS LAMP SUPPORTED GUSTS
AROUND 20 KNOTS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR LOWER CONDITIONS
MAY LINGER INTO THURSDAY EVENING AS LOW PRESSURE DEEPENS OFF THE
NORTH CAROLINA AND VIRGINIA COAST. A STRONG COLD FRONT WILL CROSS
THE AREA THURSDAY EVENING WITH CLEARING SKIES AND BREEZY
CONDITIONS IN ITS WAKE. ANOTHER LOW PRESSURE SYSTEM MAY BRING
FLIGHT RESTRICTIONS SATURDAY NIGHT AND SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
914 PM EST WED JAN 1 2014
.SYNOPSIS...
A DEVELOPING LOW PRESSURE SYSTEM WILL BRING RAIN TO THE REGION
TONIGHT AND THURSDAY. A COLD FRONT WILL CROSS THE REGION THURSDAY
NIGHT WITH COLD DRY CANADIAN HIGH PRESSURE RETURNING FRIDAY AND
SATURDAY. THE NEXT SYSTEM IS EXPECTED TO BRING SHOWERS BACK INTO
THE REGION LATE SATURDAY NIGHT THROUGH EARLY MONDAY... FOLLOWED BY
COLD HIGH PRESSURE BUILDING IN THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
IR SATELLITE IMAGERY SHOWS EXTENSIVE CLOUDINESS ACROSS THE
SOUTHEAST WITH AREA WSR-88D NETWORK SHOWING LIGHT RAIN ACROSS
CENTRAL SC AND GA WITH A HEAVIER BAND ALONG THE COAST. OVERNIGHT
LOW PRESSURE WILL EJECT FROM THE SOUTHERN PLAINS AND TRACK
NORTHEASTWARD PUSHING GULF MOISTURE BACK INTO THE FORECAST AREA.
EXPECT THE RAIN SHOWERS TO INCREASE IN COVERAGE OVERNIGHT WITH
MOST OF THE AREA SEEING RAIN BY DAYBREAK. WITH PWAT VALUES
CURRENTLY AROUND ONE INCH FOR THE NEXT SEVERAL HOURS RAINFALL
AMOUNTS WILL GENERALLY BE UNDER ONE QUARTER INCH THROUGH
DAYBREAK...WITH SLIGHTLY HIGHER AMOUNTS POSSIBLE IN THE FAR
EASTERN MIDLANDS AND SOUTHERN CSRA. TEMPERATURES HAVE ALREADY
FALLEN INTO THE MID 40S AT MOST LOCATIONS AND WILL BOTTOM OUT IN
THE LOWER 40S FOR MOST AREAS WITH MID 40S IN THE EASTERN MIDLANDS.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
A FULL LATITUDE TROUGH WILL CROSS THE FORECAST AREA THURSDAY AND
THURSDAY NIGHT. ISENTROPIC LIFT WILL BE ONGOING THURSDAY MORNING
ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA AND THIS WILL
SPREAD NORTHWESTWARD THROUGH THE MORNING INTO EARLY AFTERNOON
HOURS. PRECIPITABLE WATER VALUES WILL NOT BE AS HIGH AS THE PAST
COUPLE OF EVENTS BUT WILL SHOW A GRADIENT FROM AROUND AN INCH IN
THE NORTHWEST COUNTIES TO AROUND 1.3 INCHES IN THE SOUTHEASTERN
COUNTIES AND THE REGION WILL FALL WITHIN THE RIGHT ENTRANCE REGION
OF A 150 KT UPPER JET FURTHER SUPPORTING WIDESPREAD OMEGA OVER THE
REGION.
HAVE INCREASED POPS THURSDAY TO CATEGORICAL FOR ALL BUT THE WESTERN
MIDLANDS WHERE HIGH LIKELY POPS WILL BE HELD. LITTLE TO NO
INSTABILITY SO DO NOT EXPECT ANY THUNDER WITH THIS EVENT. QPF
AMOUNTS WILL BE LIMITED BY MODEST PRECIPITABLE WATER VALUES AND THE
SPEED OF THE SYSTEM. GENERALLY EXPECT AMOUNTS TO RANGE FROM A
QUARTER TO HALF INCH ACROSS THE WESTERN HALF OF THE FORECAST AREA
WITH A HALF TO THREE QUARTERS OF AN INCH POSSIBLE IN THE EAST.
THE TROUGH WILL BE QUICK TO MOVE THROUGH THE REGION AS SURFACE LOW
PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST BY THURSDAY EVENING
DRAWING AN ARCTIC COLD FRONT ACROSS THE FORECAST AREA THURSDAY
EVENING. RAIN SHOULD COME TO AN END QUICKLY FROM WEST TO EAST
THURSDAY EVENING WHILE STRONG COLD ADVECTION TAKES PLACE THROUGH
FRIDAY IN THE WAKE OF THE FRONT...WITH 850MB TEMPERATURES FALLING INTO
THE -5C TO -10C RANGE FRIDAY. WINDS WILL BE STRONG THURSDAY NIGHT
INTO FRIDAY MORNING. RIGHT NOW HAVE SUSTAINED WINDS IN THE 15 TO
20 MPH RANGE WITH GUSTS UP TO 30 MPH. WILL HOLD OFF ON LAKE WIND
ADVISORY UNTIL MID SHIFT TONIGHT OR MORNING UPDATE THURSDAY.
TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL IN THE 50S WITH
PRECIPITATION THURSDAY THEN FALL WELL BELOW NORMAL BY FRIDAY WITH
HIGHS STRUGGLING THROUGH THE LOWER TO MID 40S FRIDAY AND THEN A
COLD NIGHT FRIDAY NIGHT UNDER REASONABLE RADIATIONAL COOLING WITH
A VERY DRY AIR MASS IN PLACE WITH LOWS IN THE LOWER 20S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LATEST WPC GUIDANCE TRENDS TOWARD THE ECMWF WHICH IS MORE
AGGRESSIVE WITH RAIN CHANCES SAT NIGHT INTO SUNDAY NIGHT WITH THE
PASSAGE OF THE NEXT ARCTIC FRONT. EXISTING FORECAST WAS DRIER AND I
HAVE STARTED TRENDING TOWARD THE WPC GUIDANCE AS THE ECMWF HAS
GENERALLY PERFORMED BETTER FOR OUR AREA WITH PRECIP OVER THE PAST
WEEK OR TWO...ESPECIALLY IN THE LONGER TERM RANGES.
COLD HIGH PRESSURE BEGINS TO MOVE EAST OF THE AREA ON SATURDAY
BRINGING A RETURN FLOW WITH INCREASING MOISTURE. HIGHS WILL
CONTINUE BELOW NORMAL IN THE 40S. YET ANOTHER TROUGH WILL DIG
ACROSS THE MIDDLE PART OF THE COUNTRY SATURDAY NIGHT AND SUNDAY
INDUCING SURFACE LOW PRESSURE DEVELOPMENT OVER THE OHIO VALLEY ON
SUNDAY. ECMWF HAS DEEP POLAR VORTEX DROPPING INTO THE GREAT LAKES
REGION. AS SURFACE LOW MOVES NORTHEAST THE NEXT COLD/ARCTIC FRONT
WILL CROSS THE REGION.
WILL INCREASE POP INTO THE 40 TO 50 PERCENT RANGE SUNDAY. BEST
CHANCES FOR RAIN APPEARS TO BE SUNDAY NIGHT AND WILL RAISE POPS
INTO THE 50 TO 65 PERCENT RANGE. A VERY COLD ARCTIC AIR MASS WILL
BUILD OVER THE AREA BEHIND THE FRONT WITH STRONG COLD ADVECTION
MONDAY AND MONDAY NIGHT.
AHEAD OF THE FRONT SUNDAY...HIGH TEMPERATURES WILL MODERATE INTO
THE UPPER 50S AND LOWER 60S. THE COLD DRY AIR DOES NOT ARRIVE IN
EARNEST UNTIL MONDAY NIGHT WHEN TEMPERATURES WILL FALL INTO THE
MID 20S. HIGHS TUESDAY WILL STRUGGLE TO AROUND 40 DEGREES. WITH
HIGH PRESSURE OVER THE AREA TUESDAY NIGHT TEMPERATURES WILL FALL
TO AROUND 20 WITH HIGHS ON WEDNESDAY WARMING ONLY INTO THE LOWER
TO MID 40S.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE ALONG THE COAST WILL BRING INCREASING MOISTURE.
WIDESPREAD RAIN WITH LOWERING CEILINGS AND VISIBILITIES WILL OCCUR.
IFR CONDITIONS WILL DEVELOP. THE 20Z HRRR AND GFS LAMP SHOWED VFR
OR MVFR CONDITIONS THROUGH 08Z. THE GFS LAMP AND SREF GUIDANCE
INDICATED IFR CONDITIONS DEVELOPING 08Z TO 12Z.
EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR LOWER CONDITIONS
MAY LINGER INTO THURSDAY EVENING AS LOW PRESSURE DEEPENS OFF THE
NORTH CAROLINA AND VIRGINIA COAST. A STRONG COLD FRONT WILL CROSS
THE AREA THURSDAY EVENING WITH CLEARING SKIES AND BREEZY
CONDITIONS IN ITS WAKE. ANOTHER LOW PRESSURE SYSTEM MAY BRING
FLIGHT RESTRICTIONS SATURDAY NIGHT AND SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
907 PM EST WED JAN 1 2014
.SYNOPSIS...
LOW PRESSURE WILL FORM ON A NEARBY COASTAL TROUGH TONIGHT...BEFORE
MOVING AWAY TO THE NORTHEAST AHEAD OF AN ARCTIC COLD FRONT LATE
THURSDAY. COLDER...CANADIAN HIGH PRESSURE WILL BUILD THROUGH
SATURDAY. ANOTHER ARCTIC COLD FRONT WILL THEN APPROACH EARLY NEXT
WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
MAINLY LIGHT BUT MEASURABLE RAIN WITH A FEW EMBEDDED HEAVIER
POCKETS CONTINUE TO AFFECT MAINLY THE COASTAL COUNTIES THIS
EVENING. THIS SHOULD ONLY BE TEMPORARY AS SATELLITE ALREADY SHOWS
CLOUD TOPS COOLING OVER GEORGIA AND ALABAMA SUGGESTING THE MUCH
ANTICIPATED INCREASE IN FORCING FOR ASSENT WILL BE SPREADING EAST
OVER THE NEXT FEW HOURS. THIS SHOULD RESULT IN A GRADUAL INCREASE
IN RAIN COVERAGE AND INTENSITY AS THE STRENGTHENING UPPER JET
BECOMES JUXTAPOSED WITH A RIBBON OF PWATS OVER 1.25 INCHES SURGING
NORTHEAST FROM THE GULF OF MEXICO. THE 02/00Z CHS/TLH/JAX RAOBS
SAMPLED THE TROPICAL MOISTURE AXIS WELL WITH A MEASURED PWAT VALUE
OF 1.33 INCHES...1.46 INCHES AND 1.59 INCHES RESPECTIVELY.
CATEGORICAL POPS OF 90-100 PERCENT BE MAINTAINED WITH RAINFALL
AMOUNTS AVERAGING 0.50-1.00 INCH THROUGH SUNRISE...HIGHEST NEAR
THE COAST.
LIGHT NORTH WINDS ARE ADVECTING SLIGHTLY DRIER AIR INTO THE
CHARLESTON TRI-COUNTY AREA THIS EVENING WHERE TEMPERATURES ARE
STILL DROPPING EVER SO SLOWLY WHERE DIABATIC PROCESSES ARE STILL
DOMINATING. DEWPOINT DEPRESSIONS ARE SLOWLY DIMINISHING WITH
TIME...SO DO NOT ANTICIPATE TEMPERATURES IN THIS AREA WILL FALL
TOO MUCH MORE. IN FACT...ONCE THE BOUNDARY LAYER FULLY SATURATES...
TEMPERATURES MAY ACTUALLY RISE 1-2 DEGREES LATE...WHICH IS WHAT IS
SHOWN IN THE LATEST H3R AND RAP TEMPERATURE PROGNOSTICATIONS.
HAVE ONCE AGAIN LOWERED ADJUSTED OVERNIGHT LOWS DOWN A DEGREE OR
TWO OVER THE CHARLESTON TRI-COUNTY AREA. ELSEWHERE...THE
TEMPERATURE FORECASTS LOOK ON TRACK.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH SATURDAY/...
THURSDAY AND THURSDAY NIGHT...POTENT SHORTWAVE ENERGY ALONG THE
LEADING EDGE OF A MID/UPPER LEVEL TROUGH OVER THE MISSISSIPPI VALLEY
THURSDAY MORNING WILL SHIFT ACROSS THE APPALACHIANS DURING THE LATE
AFTERNOON/EARLY EVENING BEFORE MOVING OFF THE MID-ATLANTIC COAST
THURSDAY NIGHT. AS THIS OCCURS...CYCLOGENESIS WILL INITIATE ALONG
AND EAST OF THE CENTRAL APPALACHIANS AND ALONG A BAROCLINIC ZONE OFF
THE SOUTHEAST U.S. COAST CAUSING WAVES OF LOW PRESSURE TO DEVELOP.
THESE LOW PRESSURE CENTERS WILL THEN PHASE OFF THE MID-ATLANTIC
COAST...DRAGGING AN ARCTIC COLD FRONT THROUGH THE AREA LATE THURSDAY
EVENING. RAINFALL WILL BE WIDESPREAD TO START THE DAY...DUE TO A
COMBINATION OF DEEP LAYERED MOISTURE AND STRONG FORCING FOR ASCENT
WITHIN THE RIGHT ENTRANCE REGION OF A 170+ KT UPPER LEVEL JET. THE
RAIN WILL PERSIST...MODERATE AT TIMES...THROUGH MUCH OF THE
AFTERNOON BEFORE TAPING OFF FROM THE WEST LATE IN THE DAY AND DURING
THE EARLY EVENING AS THE DEEP MOISTURE SHIFTS OFFSHORE AHEAD OF THE
FRONT. STRONG COLD AIR ADVECTION WILL ENSUE BEHIND THE
FRONT...RESULTING IN BREEZY WEST-NORTHWEST WINDS THURSDAY NIGHT WITH
GUSTS UPWARDS OF 25-30 MPH AT TIMES. WIDESPREAD CLOUDS AND RAIN WILL
LIMIT HIGHS TO THE MID AND UPPER 50S ON THURSDAY. TEMPERATURES WILL
BE SLOW TO FALL THURSDAY EVENING AHEAD OF THE FRONT...BUT SHOULD
DROP OFF QUICKLY OVERNIGHT REACHING LOWS IN THE LOWER TO MID 30S IN
MOST AREAS AWAY FROM THE IMMEDIATE COAST.
FRIDAY AND FRIDAY NIGHT...THE MID/UPPER LEVEL TROUGH WILL MOVE AWAY
TO THE NORTHEAST...CAUSING A CONFLUENT FLOW ALOFT TO BECOME ZONAL
FRIDAY NIGHT. AT THE SURFACE...ARCTIC HIGH PRESSURE WILL BUILD FROM
THE NORTHWEST DURING THE DAY...BEFORE SETTLING NORTH OF THE REGION
FRIDAY NIGHT AND ALLOWING A COASTAL TROUGH TO BEGIN DEVELOPING JUST
OFFSHORE LATE. PERSISTENT COLD AIR ADVECTION WITHIN A NORTHERLY FLOW
WILL RESULT IN VERY COOL TEMPERATURES FRIDAY...WITH THICKNESS VALUES
SUGGESTING HIGHS ONLY IN THE LOWER TO MID 40S. WHILE THIS IS A
POSSIBILITY...THE FORECAST FACTORS IN ABUNDANT SUNSHINE AND
INDICATES HIGHS IN THE MID 40S WITH SOME UPPER 40S NEAR THE ALTAMAHA
RIVER...WHICH IS STILL A BIT BELOW GUIDANCE. FRIDAY NIGHT WILL BE
COLD WITH LOWS IN THE MID TO UPPER 20S AWAY FROM THE COAST...BUT IF
WINDS MANAGE TO FULLY DECOUPLE THAN TEMPERATURES COULD FALL FURTHER.
SATURDAY...THE MID/UPPER LEVEL FLOW WILL BECOME MORE CYCLONIC IN
RESPONSE TO A BUILDING TROUGH OVER THE NORTHERLY PLAINS.
MEANWHILE...SURFACE HIGH PRESSURE WILL SHIFT INTO THE WESTERN
ATLANTIC CAUSING THE COASTAL TROUGH TO TIGHTEN JUST OFF THE COASTS
OF GEORGIA AND SOUTH CAROLINA. WEAK LOW LEVEL CONVERGENCE IN
VICINITY OF THE TROUGH AND FAVORABLE ONSHORE TRAJECTORIES COULD
RESULT IN AN ISOLATED SHOWER ADVECTING INTO NORTH COASTAL
GEORGIA...OTHERWISE SUBSIDENCE AND A LACK OF DEEP MOISTURE WILL KEEP
THE REST OF THE AREA RAIN FREE. TEMPERATURES WILL SLOWLY
MODERATE...WITH HIGHS IN THE LOWER TO MID 50S.
LAKE WINDS...A STRONG COLD FRONT WILL CROSS THE REGION THURSDAY
NIGHT. COLD AIR WILL SPREAD ACROSS THE RELATIVELY WARMER LAKE
WATERS...RESULTING IN IMPROVED MIXING PROFILES. LOW LEVEL WINDS WILL
BE STRENGTHENING...AND NORTHWEST GUSTS TO 25 KNOTS APPEAR LIKELY. AS
A RESULT...A LAKE WIND ADVISORY HAS BEEN ISSUED FOR LAKE MOULTRIE
THURSDAY NIGHT THROUGH FRIDAY MORNING.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
OVERALL...MODEL TRENDS SEEM TO BE CONVERGING ON A SIMILAR SOLUTION
IN THE LONG TERM PERIOD. THE MAIN STORY WILL REVOLVE AROUND ANOTHER
VIGOROUS SHORTWAVE DIGGING ACROSS THE CENTRAL AND EASTERN
CONUS...RESULTING IN A DEEP LONG WAVE TROUGH INTO THE MIDDLE PART OF
NEXT WEEK. HIGH PRESSURE WILL BEGIN TO LOSE ITS IMPACT ON THE REGION
AS AN AREA OF LOW PRESSURE ORGANIZES AHEAD OF THE AFOREMENTIONED
SHORTWAVE. THERE ARE STILL SOME SIGNIFICANT DIFFERENCES BETWEEN THE
ECMWF AND GFS CONCERNING THE STRENGTH OF THE SURFACE LOW AND THE
AMOUNT OF PRECIP ALONG THE COLD FRONT THAT IS PROGGED TO SWEEP
THROUGH LATE SUNDAY NIGHT. THE ECMWF IS CONSIDERABLY DEEPER WITH THE
LOW AND DEPICTS MUCH MORE PRECIP. GIVEN THE LACK OF CONFIDENCE IN
THE PRECIP COVERAGE...HAVE GONE WITH CHANCE POPS FOR SUNDAY AND
SUNDAY NIGHT. THE COLD FRONT WILL RIP THROUGH THE AREA EARLY MONDAY
AS A VERY STRONG 1055 MB CANADIAN HIGH PRESSURE HELPS PUSH THROUGH
ANOTHER ARCTIC COLD FRONT. THIS AIRMASS APPEARS TO BE EVEN COLDER
THAN THE ONE EXPECTED LATE THIS WEEK WITH 850 MB TEMPS PLUMMETING TO
AROUND -10 C IN THE NORTHERN REACHES OF THE FORECAST AREA. LOW LEVEL
THICKNESSES ONLY SUPPORT HIGHS IN THE UPPER 30S FOR TUESDAY. I HAVE
TRENDED THE FORECAST DOWN SIGNIFICANTLY INTO THE MID/UPPER 40S...AND
IF MODEL TRENDS CONTINUE THE DOWNWARD TRENDING WILL CONTINUE WITH
SUBSEQUENT FORECASTS. THE COLD HIGH PRESSURE WILL CONTINUE BUILDING
INTO THE AREA THROUGH THE MIDDLE OF NEXT WEEK.
&&
.AVIATION /02Z THURSDAY THROUGH MONDAY/...
CONDITIONS WILL STEADILY DETERIORATE AT KCHS/KSAV THIS EVENING AS
CIGS/VSBYS LOWER AS RAIN INTENSIFIES. THERE IS A HIGH CHANCE THAT
IFR CONDITIONS WILL OCCUR BY MID-LATE EVENING WITH LIFR CIGS
PREVAILING BETWEEN MIDNIGHT AND SUNRISE THURSDAY. ALL GUIDANCE IS
QUITE PESSIMISTIC WITH CONDITIONS OVERNIGHT AND THE 00Z TAFS HAVE
BEEN TRENDED LOWER FROM THE 18Z TAF CYCLE. LIGHT RAIN COULD
MITIGATE CONDITIONS SOMEWHAT...BUT STRATUS BUILD-DOWN PROCESSES
SHOULD ALLOW CIGS TO DROP BELOW 500 FT AND POSSIBLY AS LOW AS
AIRFIELD MINIMUMS OF 200 FT. CIGS WILL NOT RECOVER MUCH AFTER
SUNRISE AS ONGOING LIFT/LIGHT RAIN WILL PREVENT CIGS FROM RISING
ABOVE IFR THRESHOLDS.
EXTENDED AVIATION OUTLOOK...WIDESPREAD FLIGHT RESTRICTIONS ARE
EXPECTED INTO THURSDAY EVENING BEFORE A STRONG COLD FRONT MOVES
THROUGH THURSDAY NIGHT. GUSTY WINDS ARE EXPECTED ALONG AND BEHIND
THE FRONT...CONTINUING THROUGH THE DAY ON FRIDAY.
&&
.MARINE...
TONIGHT...NO HIGHLIGHTS EXPECTED. GENERALLY NE WINDS LESS THAN 15
KTS BECOMING VARIABLE LATER TONIGHT AS A WEAK SURFACE LOW PRESSURE
CENTER TRIES TO FORM JUST EAST OF THE OUTER WATERS. VERY LOW
CLOUDS...ESPECIALLY CLOSER TO THE COAST WILL LIKELY FORM...WHICH
MAY REDUCE VSBYS DOWN TO 1 TO 2SM AT TIMES. HOWEVER...CONFIDENCE
WAS NOT HIGH ENOUGH TO PUT FOG IN THE FORECAST.
THURSDAY THROUGH SUNDAY...A STRENGTHENING AREA OF LOW PRESSURE WILL
PULL AWAY FROM THE REGION LATE ON THURSDAY FOLLOWED BY A STRONG COLD
FRONT THURSDAY NIGHT. CONDITIONS WILL BE PRETTY QUIET OTHER THAN
WIDESPREAD PRECIPITATION AHEAD OF THE STRONG COLD FRONT ON THURSDAY.
WHEN THE FRONT PUSHES THROUGH AND STRONG COLD ADVECTION
COMMENCES...CONDITIONS WILL RAPIDLY DETERIORATE WITH INCREASING
NORTHWEST WINDS. SUSTAINED WINDS OF 20 TO 30 KT WITH GUSTS INTO THE
30 TO 35 KT RANGE ARE EXPECTED ACROSS THE NEAR SHORE WATERS WITH
SUSTAINED WINDS OF 25 TO 35 KT WITH GUSTS UPWARDS OF 40 KT EXPECTED
OVER THE OUTER GEORGIA WATERS. IT STILL APPEARS THAT THERE IS A LOW
CHANCE FOR A BRIEF PERIOD OF WINDS REACHING GALE FORCE FOR THE
NEARSHORE WATERS BUT FOR NOW A SMALL CRAFT ADVISORY HAS BEEN ISSUED.
THERE IS MUCH HIGHER CONFIDENCE OF GALE FORCE WINDS OCCURRING OVER
THE OUTER GEORGIA WATERS AND A GALE WATCH HAS BEEN ISSUED. ELEVATED
WINDS/SEAS WILL PERSIST THROUGH FRIDAY MORNING...WITH CONDITIONS
IMPROVING FRIDAY AFTERNOON AND FRIDAY NIGHT. HIGH PRESSURE WILL
BUILD IN SATURDAY WITH A COASTAL TROUGH ACROSS THE WATERS. THE
TROUGH MAY THEN WASH OUT A BIT THROUGH SUNDAY. LOCAL PINCHING OF THE
PRESSURE GRADIENT WITH IN THE COASTAL TROUGH WILL RESULT IN SOME
ELEVATED WINDS/SEAS...AND MAY NECESSITATE ADDITIONAL ADVISORIES OVER
THE WEEKEND.
&&
.TIDES/COASTAL FLOODING...
ASTRONOMICAL INFLUENCES INCLUDING THE PERIGEE AND NEW MOON CYCLE
WILL RESULT IN ELEVATED TIDES THURSDAY AND FRIDAY. THE THURSDAY
MORNING HIGH TIDE MAY REACH SHALLOW COASTAL FLOODING CRITERIA
THANKS TO LIGHT FLOW AND A GENERAL AREA OF LOW PRESSURE ACROSS THE
REGION. HOWEVER...THE ASTRONOMICAL INFLUENCES WILL LIKELY BE
NEGATED FRIDAY MORNING THANKS TO STRONG OFFSHORE FLOW. SHALLOW
COASTAL FLOODING APPEARS UNLIKELY FOR FRIDAY.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...LAKE WIND ADVISORY FROM 9 PM THURSDAY TO NOON EST FRIDAY FOR
SCZ045.
MARINE...SMALL CRAFT ADVISORY FROM 7 PM THURSDAY TO NOON EST FRIDAY FOR
AMZ352-354.
SMALL CRAFT ADVISORY FROM 9 PM THURSDAY TO 5 PM EST FRIDAY FOR
AMZ350.
GALE WATCH FROM THURSDAY EVENING THROUGH FRIDAY MORNING FOR
AMZ374.
SMALL CRAFT ADVISORY FROM 9 PM THURSDAY TO NOON EST FRIDAY FOR
AMZ330.
&&
$$
ST
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
647 PM EST WED JAN 1 2014
.SYNOPSIS...
A DEVELOPING LOW PRESSURE SYSTEM WILL BRING RAIN TO THE REGION
TONIGHT AND THURSDAY. A COLD FRONT WILL CROSS THE REGION THURSDAY
NIGHT WITH COLD DRY CANADIAN HIGH PRESSURE RETURNING FRIDAY AND
SATURDAY. THE NEXT SYSTEM IS EXPECTED TO BRING SHOWERS BACK INTO
THE REGION LATE SATURDAY NIGHT THROUGH EARLY MONDAY... FOLLOWED BY
COLD HIGH PRESSURE BUILDING IN THROUGH EARLY NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
HIGH AND MID LEVEL CLOUDS WILL CONTINUE TO BLANKET THE AREA IN
SOUTHWEST FLOW ALOFT. CURRENT RADAR INDICATING PATCHES OF LIGHT
RAIN CROSSING THE CSRA AND SOUTHERN MIDLANDS.
HIGH PRESSURE CENTERED OFF THE MID-ATLANTIC COAST WAS RIDGING
INTO THE CAROLINAS AND GEORGIA. PWAT RANGING FROM LESS THAN HALF
AN INCH NORTH TO AROUND ONE INCH SOUTH IS FORECAST TO AROUND ONE
INCH NORTH TO 1.30 INCHES SOUTH TONIGHT. ALL MODELS INDICATE
ISENTROPIC LIFT INCREASING.
FORECAST MODELS CONTINUE THE CHANCE FOR RAIN IN THE SOUTHERN AND
EASTERN CWA THROUGH MIDNIGHT...THEN PUSH RAINFALL NORTH THE
REMAINDER OF THE NIGHT. HAVE CONTINUED WITH LIKELY/CATEGORICAL
POPS SOUTH/EAST...AND CHANCE POPS ACROSS THE EXTREME NORTH GIVEN
INCREASING ISENTROPIC LIFT. OVERNIGHT LOWS IN THE LOW/MID 40S ARE
CONSISTENT WITH MOS GUIDANCE.
&&
.SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/...
A FULL LATITUDE TROUGH WILL CROSS THE FORECAST AREA THURSDAY AND
THURSDAY NIGHT. ISENTROPIC LIFT WILL BE ONGOING THURSDAY MORNING
ACROSS THE SOUTHEASTERN HALF OF THE FORECAST AREA AND THIS WILL
SPREAD NORTHWESTWARD THROUGH THE MORNING INTO EARLY AFTERNOON
HOURS. PRECIPITABLE WATER VALUES WILL NOT BE AS HIGH AS THE PAST
COUPLE OF EVENTS BUT WILL SHOW A GRADIENT FROM AROUND AN INCH IN
THE NORTHWEST COUNTIES TO AROUND 1.3 INCHES IN THE SOUTHEASTERN
COUNTIES AND THE REGION WILL FALL WITHIN THE RIGHT ENTRANCE REGION
OF A 150 KT UPPER JET FURTHER SUPPORTING WIDESPREAD OMEGA OVER THE
REGION.
HAVE INCREASED POPS THURSDAY TO CATEGORICAL FOR ALL BUT THE WESTERN
MIDLANDS WHERE HIGH LIKELY POPS WILL BE HELD. LITTLE TO NO
INSTABILITY SO DO NOT EXPECT ANY THUNDER WITH THIS EVENT. QPF
AMOUNTS WILL BE LIMITED BY MODEST PRECIPITABLE WATER VALUES AND THE
SPEED OF THE SYSTEM. GENERALLY EXPECT AMOUNTS TO RANGE FROM A
QUARTER TO HALF INCH ACROSS THE WESTERN HALF OF THE FORECAST AREA
WITH A HALF TO THREE QUARTERS OF AN INCH POSSIBLE IN THE EAST.
THE TROUGH WILL BE QUICK TO MOVE THROUGH THE REGION AS SURFACE LOW
PRESSURE DEVELOPS OFF THE MID ATLANTIC COAST BY THURSDAY EVENING
DRAWING AN ARCTIC COLD FRONT ACROSS THE FORECAST AREA THURSDAY
EVENING. RAIN SHOULD COME TO AN END QUICKLY FROM WEST TO EAST
THURSDAY EVENING WHILE STRONG COLD ADVECTION TAKES PLACE THROUGH
FRIDAY IN THE WAKE OF THE FRONT...WITH 850MB TEMPERATURES FALLING INTO
THE -5C TO -10C RANGE FRIDAY. WINDS WILL BE STRONG THURSDAY NIGHT
INTO FRIDAY MORNING. RIGHT NOW HAVE SUSTAINED WINDS IN THE 15 TO
20 MPH RANGE WITH GUSTS UP TO 30 MPH. WILL HOLD OFF ON LAKE WIND
ADVISORY UNTIL MID SHIFT TONIGHT OR MORNING UPDATE THURSDAY.
TEMPERATURES ARE EXPECTED TO BE NEAR NORMAL IN THE 50S WITH
PRECIPITATION THURSDAY THEN FALL WELL BELOW NORMAL BY FRIDAY WITH
HIGHS STRUGGLING THROUGH THE LOWER TO MID 40S FRIDAY AND THEN A
COLD NIGHT FRIDAY NIGHT UNDER REASONABLE RADIATIONAL COOLING WITH
A VERY DRY AIR MASS IN PLACE WITH LOWS IN THE LOWER 20S.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
LATEST WPC GUIDANCE TRENDS TOWARD THE ECMWF WHICH IS MORE
AGGRESSIVE WITH RAIN CHANCES SAT NIGHT INTO SUNDAY NIGHT WITH THE
PASSAGE OF THE NEXT ARCTIC FRONT. EXISTING FORECAST WAS DRIER AND I
HAVE STARTED TRENDING TOWARD THE WPC GUIDANCE AS THE ECMWF HAS
GENERALLY PERFORMED BETTER FOR OUR AREA WITH PRECIP OVER THE PAST
WEEK OR TWO...ESPECIALLY IN THE LONGER TERM RANGES.
COLD HIGH PRESSURE BEGINS TO MOVE EAST OF THE AREA ON SATURDAY
BRINGING A RETURN FLOW WITH INCREASING MOISTURE. HIGHS WILL
CONTINUE BELOW NORMAL IN THE 40S. YET ANOTHER TROUGH WILL DIG
ACROSS THE MIDDLE PART OF THE COUNTRY SATURDAY NIGHT AND SUNDAY
INDUCING SURFACE LOW PRESSURE DEVELOPMENT OVER THE OHIO VALLEY ON
SUNDAY. ECMWF HAS DEEP POLAR VORTEX DROPPING INTO THE GREAT LAKES
REGION. AS SURFACE LOW MOVES NORTHEAST THE NEXT COLD/ARCTIC FRONT
WILL CROSS THE REGION.
WILL INCREASE POP INTO THE 40 TO 50 PERCENT RANGE SUNDAY. BEST
CHANCES FOR RAIN APPEARS TO BE SUNDAY NIGHT AND WILL RAISE POPS
INTO THE 50 TO 65 PERCENT RANGE. A VERY COLD ARCTIC AIR MASS WILL
BUILD OVER THE AREA BEHIND THE FRONT WITH STRONG COLD ADVECTION
MONDAY AND MONDAY NIGHT.
AHEAD OF THE FRONT SUNDAY...HIGH TEMPERATURES WILL MODERATE INTO
THE UPPER 50S AND LOWER 60S. THE COLD DRY AIR DOES NOT ARRIVE IN
EARNEST UNTIL MONDAY NIGHT WHEN TEMPERATURES WILL FALL INTO THE
MID 20S. HIGHS TUESDAY WILL STRUGGLE TO AROUND 40 DEGREES. WITH
HIGH PRESSURE OVER THE AREA TUESDAY NIGHT TEMPERATURES WILL FALL
TO AROUND 20 WITH HIGHS ON WEDNESDAY WARMING ONLY INTO THE LOWER
TO MID 40S.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
LOW PRESSURE ALONG THE COAST WILL BRING INCREASING MOISTURE.
WIDESPREAD RAIN WITH LOWERING CEILINGS AND VISIBILITIES WILL OCCUR.
IFR CONDITIONS WILL DEVELOP. THE 20Z HRRR AND GFS LAMP SHOWED VFR
OR MVFR CONDITIONS THROUGH 08Z. THE GFS LAMP AND SREF GUIDANCE
INDICATED IFR CONDITIONS DEVELOPING 08Z TO 12Z.
EXTENDED AVIATION OUTLOOK...WIDESPREAD MVFR OR LOWER CONDITIONS
MAY LINGER INTO THURSDAY EVENING AS LOW PRESSURE DEEPENS OFF THE
NORTH CAROLINA AND VIRGINIA COAST. A STRONG COLD FRONT WILL CROSS
THE AREA THURSDAY EVENING WITH CLEARING SKIES AND BREEZY
CONDITIONS IN ITS WAKE. ANOTHER LOW PRESSURE SYSTEM MAY BRING
FLIGHT RESTRICTIONS SATURDAY NIGHT AND SUNDAY.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
835 PM CST WED JAN 1 2014
.UPDATE...
ISSUED AT 833 PM CST WED JAN 1 2014
ANOTHER ROW OF COUNTIES HAS BEEN DROPPED FROM THE NORTHERN EDGE OF
THE WINTER WEATHER ADVISORY AS THE AREA OF SNOW CONTINUES TO MOVE
SOUTHEAST.
UPDATE ISSUED AT 623 PM CST WED JAN 1 2014
TRENDS PER REGIONAL RADAR COMPOSITE SHOW THE BACK EDGE OF THE
ACCUMULATING SNOW FROM NEAR STERLING/ROCKFALLS THROUGH MOLINE AND
WASHINGTON IA AND MOVING STEADILY SOUTHEAST. THIS IS IN GOOD
AGREEMENT WITH THE 22Z RUN OF THE HRRR PRECIP FIELD. THE HRRR
SHOWS THE MEASURABLE SNOW CONTINUING TO PUSH STEADILY SOUTHEAST
THIS EVENING. WITH THESE TRENDS IN MIND THE PORTION OF THE WSW
THAT RAN UNTIL 6 PM WAS ALLOWED TO EXPIRE. SOME AREAS WHERE THE
WSW EXPIRED MAY SEE ANOTHER HOUR OR 2 OF LIGHT SNOW BUT ADDITIONAL
ACCUMULATIONS SHOULD BE WELL UNDER AN INCH. OTHERWISE NO CHANGES
WERE MADE TO THE REST OF THE FORECAST. WILL CONTINUE TO CHIP AWAY AT
THE NORTH EDGE OF THE REMAINING WINTER WX ADVISORY AS THE SNOW
CONTINUES TO MOVE SOUTHEAST.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 315 PM CST WED JAN 1 2014
WILL LEAVE ONGOING WINTER WX ADVISORIES GO WITH THE NORTHERN HALF
OF THE ADVISORY SECTION PROBABLY GETTING UP TO ANOTHER INCH
THROUGH 00Z...AND FRONTOGENESIS BAND OF SNOW JUST STARTING TO MAKE
IT ACRS THE SOUTHERN CWA AND THE SOUTHERN SECTION OF THE ADVISORY
WHICH GOES THROUGH 06Z TONIGHT. ALL IN ALL MOST SITES IN THE
ADVISORIES TO GET FROM 2-3 INCHES FROM 12Z THIS MORNING THOUGH
THIS EVENING...BUT BRISK NORTH TO NORTHEAST WINDS OF 10-20 MPH PRODUCING
DRIFTING OF POWDERY SNOW AND REDUCED VSBYS IN BOUTS OF HEAVIER
SNOW WITH FOG MAKING FOR HAZARDOUS TRAVEL SUPPORTING THE NEED OF
HEADLINES. PLUS STILL FEEL WITH UPTICK IN ELEVATED FRONTOGENETICAL
FORCING THIS EVENING...AREAS ALONG AND SOUTH OF A LINE FROM
FAIRFIELD IA TO NORTHEAST OF MONMOUTH WILL SEE AMOUNTS MORE IN THE
LINE OF 2-4 INCHES WITH SOME ISOLATED 5 INCH AMOUNTS POSSIBLE BY MIDNIGHT.
THEN AS NORTHEASTERLY SFC WINDS BACK TO THE NORTH...MORE OF A COLD
FETCH/CAA WILL OCCUR LATER TONIGHT AND MAKE FOR LOWS IN THE LOW
TO MID SINGLE DIGITS ABOVE ZERO EAST OF THE MS RVR INTO NORTHEASTERN
MO...AND SUBZERO LOWS GENERALLY ACRS THE NORTHWESTERN HALF OF THE
DVN CWA...-5 TO -10F IN DEEPER SNOWPACK AREAS AND RVR VALLEYS OF THE
NORTHWESTERN THIRD...AND WAPSI VALLEY TO THE MS RVR. COMBINED
WITH IN-BUILDING PRESSURE GRADIENT OFF NORTHERN PLAINS ARCTIC
RIDGE AND SUSTAINED 8-12 MPH WINDS...THESE TEMPS WILL PRODUCE WIND
CHILL ADVISORY CRITERIA FROM JUST AFTER MIDNIGHT THROUGH 11 AM CST OR
NOON THU FOR AREAS GENERALLY ALONG AND NORTHWEST OF A LINE FROM
STOCKTON IN FAR NW IL...TO TIPTON IA...AND TO FAIRFIELD IA. WILL
ISSUE THE WIND CHILL ADVISORY FOR THESE AREAS WITH THE POTENTIAL
TO EXPAND A TIER OF COUNTIES EASTWARD IF THE COLD SEEPAGE CREEPS
FURTHER TO THE EAST THAN CURRENTLY EXPECTED. CLOUDY TO MOSTLY
CLOUDY SKIES CONTINUE THROUGH TONIGHT,,,WITH THE POSSIBILITY OF
SOME NEWLY PRODUCED FLURRIES MOVING ACRS THE CWA FROM NORTH TO SOUTH
AFTER THE MAIN BAND OF SNOW SLIPS OFF TO THE SOUTHEAST.
ARCTIC HIGH BARRELS IT/S WAY ACRS IA INTO NORTHWESTERN IL AS DAY
PROGRESSES WITH ONGOING STOUT CAA. DESPITE THIS RIDGE CLEARING
THINGS OUT/EXCEPT MAYBE SOME BRIEF WDLY SCTRD INSTABILITY FLURRIES
OR SHOWERS/...TEMPS WILL HAVE A HARD TIME RECOVERING MUCH FROM
MORNING LOWS...SINGLE DIGITS ABOVE ZERO EXCEPT THE FAR EAST AND
SOUTHEAST WHICH MAY HIT +10 OR A FEW DEGREES WARMER. ..12..
.LONG TERM...(THURSDAY NIGHT THROUGH NEXT WEDNESDAY)
ISSUED AT 315 PM CST WED JAN 1 2014
THE MAIN FORECAST THIS PERIOD WILL BE TEMPERATURES THROUGH THE
PERIOD. MODELS ARE IN GOOD OVERALL AGREEMENT WITH THE LARGE SCALE
PATTERN BUT THERE IS SOME DISAGREEMENT IN THE TIMING AND PLACEMENT
OF FEATURES BY THIS WEEKEND.
THE CURRENT ACTIVE WEATHER REGIME IS FORECAST TO CONTINUE INTO AT
LEAST EARLY NEXT WEEK AS SEVERAL REINFORCING SHOTS OF COLD AIR DROP
INTO THE GREAT PLAINS. SHORTWAVE RIDGING WILL BUILD INTO THE REGION
BY THURSDAY NIGHT INTO FRIDAY MORNING WITH SKIES CLEARING
OVERNIGHT. 850 TEMPERATURES OF -15*C TO -20*C ACROSS THE REGION
WILL LEAD TO POTENTIAL NEAR RECORD LOWS ON FRIDAY MORNING. PLEASE
SEE THE CLIMATE SECTION BELOW.
HIGH PRESSURE WILL SHIFT EASTWARD ON FRIDAY MORNING ALLOWING FOR
WINDS TO VEER TO THE SOUTH AND BEGIN WARM ADVECTING INTO THE REGION ON
FRIDAY AND SATURDAY AHEAD OF THE NEXT ALBERTA CLIPPER. A TIGHTENING
PRESSURE GRADIENT ON FRIDAY WILL LEAD TO BREEZY CONDITIONS INTO
SATURDAY. SATURDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH
TEMPERATURES CLOSER TO NORMALS IN THE UPPER 20S TO LOWER 30S.
CLOUDS WILL BEGIN OVERSPREADING THE REGION ON SATURDAY AHEAD OF A
CLIPPER THAT WILL DRAG A STRONG COLD FRONT ACROSS THE REGION
SATURDAY AFTERNOON INTO THE EVENING. THE BETTER DYNAMICS AND
MOISTURE WITH THIS SYSTEM WILL BE ALONG AND BEHIND THE FRONT. THE
GFS IS QUICKER WITH THE SYSTEM AND ENDS PRECIPITATION BY 06 UTC ON
SUNDAY WHILE THE ECMWF IS WETTER AND CONTINUES THE PRECIPITATION
THROUGH 18 UTC ON SUNDAY. HAVE A COMBINATION OF THE TWO SOLUTIONS
GOING INTO SUNDAY WITH SOME LINGERING SNOW THROUGH 18 UTC.
VERY STRONG COLD ADVECTION WILL BE ONGOING SUNDAY NIGHT INTO MONDAY
WITH A STRONG 1040 TO 1050 MB SURFACE HIGH BUILDING SOUTHEASTWARD
INTO MONTANA. THE GFS AND ECMWF SHOW THE SURFACE HIGH MODERATING TO
BETWEEN 1030 TO 1040 MB BY TUESDAY MORNING ACROSS IOWA. 850
TEMPERATURES WILL HAVE COOLED TO -20*C TO -30*C BY 12 UTC ON MONDAY
AND FURTHER COOLING TO -24*C TO -30*C BY 12 UTC ON TUESDAY. THESE
TEMPERATURES ARE 2 TO 3 STANDARD DEVIATIONS BELOW THE MEAN FOR
JANUARY SO THIS WILL BE AN UNUSUALLY COLD AIRMASS BUILDING INTO THE
REGION EARLY NEXT WEEK. SURFACE TEMPERATURES MAY REMAIN BELOW ZERO
SUNDAY NIGHT THROUGH TUESDAY. SOME OF THIS COLD AIR MAY BE HIGHLY
DEPENDENT ON THE SNOWPACK TO OUR NORTH. AFTER TUESDAY...HIGH
PRESSURE WILL SHIFT EASTWARD ALLOWING FOR A RETURN TO MORE MODERATE
AIR FOR THE MIDDLE OF NEXT WEEK. IN ADDITION TO THE COLD AIR THE
PRESSURE GRADIENT WILL BE TIGHT ACROSS THE REGION ON MONDAY SO
ANOTHER BREEZY OVERNIGHT WHICH WILL MAKE TEMPERATURES FEEL MUCH
COLDER THAN THE AIR. COUSINS
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 623 PM CST WED JAN 1 2014
CONDITIONS WILL CONTINUE TO IMPROVE SOUTH OF I80 AS THE SNOW
PUSHES SOUTHEAST. BY LATE THIS EVENING EXPECT VFR CONDITIONS AT
ALL OF THE TAF SITES. MODELS ARE SHOWING SOME LOW LEVEL MOISTURE
REMAINING OVER THE AREA THROUGH MID-DAY THURSDAY SO SOME PATCHY
MVFR CIGS CANNOT BE RULED OUT TONIGHT AND THURSDAY MORNING.
&&
.CLIMATE...
ISSUED AT 315 PM CST WED JAN 1 2014
RECORD LOWS FOR JANUARY 2...
MOLINE.........-27 IN 1979
CEDAR RAPIDS...-19 IN 1979
DUBUQUE........-22 IN 1879
BURLINGTON.....-15 IN 1979
RECORD LOWS FOR JANUARY 3...
MOLINE.........-16 IN 1887
CEDAR RAPIDS...-15 IN 1919
DUBUQUE........-24 IN 1887
BURLINGTON.....-16 IN 1919
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR BENTON-BUCHANAN-CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LINN-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR DES
MOINES-LEE-VAN BUREN.
IL...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR JO DAVIESS.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR HANCOCK-
HENDERSON-MCDONOUGH-WARREN.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
SCOTLAND.
&&
$$
UPDATE...DLF
SHORT TERM...12
LONG TERM...COUSINS
AVIATION...DLF
CLIMATE...COUSINS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
634 PM CST WED JAN 1 2014
.UPDATE...
ISSUED AT 623 PM CST WED JAN 1 2014
TRENDS PER REGIONAL RADAR COMPOSITE SHOW THE BACK EDGE OF THE
ACCUMULATING SNOW FROM NEAR STERLING/ROCKFALLS THROUGH MOLINE AND
WASHINGTON IA AND MOVING STEADILY SOUTHEAST. THIS IS IN GOOD
AGREEMENT WITH THE 22Z RUN OF THE HRRR PRECIP FIELD. THE HRRR
SHOWS THE MEASURABLE SNOW CONTINUING TO PUSH STEADILY SOUTHEAST
THIS EVENING. WITH THESE TRENDS IN MIND THE PORTION OF THE WSW
THAT RAN UNTIL 6 PM WAS ALLOWED TO EXPIRE. SOME AREAS WHERE THE
WSW EXPIRED MAY SEE ANOTHER HOUR OR 2 OF LIGHT SNOW BUT ADDITIONAL
ACCUMULATIONS SHOULD BE WELL UNDER AN INCH. OTHERWISE NO CHANGES
WERE MADE TO THE REST OF THE FORECAST. WILL CONTINUE TO CHIP AWAY AT
THE NORTH EDGE OF THE REMAINING WINTER WX ADVISORY AS THE SNOW
CONTINUES TO MOVE SOUTHEAST.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 315 PM CST WED JAN 1 2014
WILL LEAVE ONGOING WINTER WX ADVISORIES GO WITH THE NORTHERN HALF
OF THE ADVISORY SECTION PROBABLY GETTING UP TO ANOTHER INCH
THROUGH 00Z...AND FRONTOGENESIS BAND OF SNOW JUST STARTING TO MAKE
IT ACRS THE SOUTHERN CWA AND THE SOUTHERN SECTION OF THE ADVISORY
WHICH GOES THROUGH 06Z TONIGHT. ALL IN ALL MOST SITES IN THE
ADVISORIES TO GET FROM 2-3 INCHES FROM 12Z THIS MORNING THOUGH
THIS EVENING...BUT BRISK NORTH TO NORTHEAST WINDS OF 10-20 MPH PRODUCING
DRIFTING OF POWDERY SNOW AND REDUCED VSBYS IN BOUTS OF HEAVIER
SNOW WITH FOG MAKING FOR HAZARDOUS TRAVEL SUPPORTING THE NEED OF
HEADLINES. PLUS STILL FEEL WITH UPTICK IN ELEVATED FRONTOGENETICAL
FORCING THIS EVENING...AREAS ALONG AND SOUTH OF A LINE FROM
FAIRFIELD IA TO NORTHEAST OF MONMOUTH WILL SEE AMOUNTS MORE IN THE
LINE OF 2-4 INCHES WITH SOME ISOLATED 5 INCH AMOUNTS POSSIBLE BY MIDNIGHT.
THEN AS NORTHEASTERLY SFC WINDS BACK TO THE NORTH...MORE OF A COLD
FETCH/CAA WILL OCCUR LATER TONIGHT AND MAKE FOR LOWS IN THE LOW
TO MID SINGLE DIGITS ABOVE ZERO EAST OF THE MS RVR INTO NORTHEASTERN
MO...AND SUBZERO LOWS GENERALLY ACRS THE NORTHWESTERN HALF OF THE
DVN CWA...-5 TO -10F IN DEEPER SNOWPACK AREAS AND RVR VALLEYS OF THE
NORTHWESTERN THIRD...AND WAPSI VALLEY TO THE MS RVR. COMBINED
WITH IN-BUILDING PRESSURE GRADIENT OFF NORTHERN PLAINS ARCTIC
RIDGE AND SUSTAINED 8-12 MPH WINDS...THESE TEMPS WILL PRODUCE WIND
CHILL ADVISORY CRITERIA FROM JUST AFTER MIDNIGHT THROUGH 11 AM CST OR
NOON THU FOR AREAS GENERALLY ALONG AND NORTHWEST OF A LINE FROM
STOCKTON IN FAR NW IL...TO TIPTON IA...AND TO FAIRFIELD IA. WILL
ISSUE THE WIND CHILL ADVISORY FOR THESE AREAS WITH THE POTENTIAL
TO EXPAND A TIER OF COUNTIES EASTWARD IF THE COLD SEEPAGE CREEPS
FURTHER TO THE EAST THAN CURRENTLY EXPECTED. CLOUDY TO MOSTLY
CLOUDY SKIES CONTINUE THROUGH TONIGHT,,,WITH THE POSSIBILITY OF
SOME NEWLY PRODUCED FLURRIES MOVING ACRS THE CWA FROM NORTH TO SOUTH
AFTER THE MAIN BAND OF SNOW SLIPS OFF TO THE SOUTHEAST.
ARCTIC HIGH BARRELS IT/S WAY ACRS IA INTO NORTHWESTERN IL AS DAY
PROGRESSES WITH ONGOING STOUT CAA. DESPITE THIS RIDGE CLEARING
THINGS OUT/EXCEPT MAYBE SOME BRIEF WDLY SCTRD INSTABILITY FLURRIES
OR SHOWERS/...TEMPS WILL HAVE A HARD TIME RECOVERING MUCH FROM
MORNING LOWS...SINGLE DIGITS ABOVE ZERO EXCEPT THE FAR EAST AND
SOUTHEAST WHICH MAY HIT +10 OR A FEW DEGREES WARMER. ..12..
.LONG TERM...(THURSDAY NIGHT THROUGH NEXT WEDNESDAY)
ISSUED AT 315 PM CST WED JAN 1 2014
THE MAIN FORECAST THIS PERIOD WILL BE TEMPERATURES THROUGH THE
PERIOD. MODELS ARE IN GOOD OVERALL AGREEMENT WITH THE LARGE SCALE
PATTERN BUT THERE IS SOME DISAGREEMENT IN THE TIMING AND PLACEMENT
OF FEATURES BY THIS WEEKEND.
THE CURRENT ACTIVE WEATHER REGIME IS FORECAST TO CONTINUE INTO AT
LEAST EARLY NEXT WEEK AS SEVERAL REINFORCING SHOTS OF COLD AIR DROP
INTO THE GREAT PLAINS. SHORTWAVE RIDGING WILL BUILD INTO THE REGION
BY THURSDAY NIGHT INTO FRIDAY MORNING WITH SKIES CLEARING
OVERNIGHT. 850 TEMPERATURES OF -15*C TO -20*C ACROSS THE REGION
WILL LEAD TO POTENTIAL NEAR RECORD LOWS ON FRIDAY MORNING. PLEASE
SEE THE CLIMATE SECTION BELOW.
HIGH PRESSURE WILL SHIFT EASTWARD ON FRIDAY MORNING ALLOWING FOR
WINDS TO VEER TO THE SOUTH AND BEGIN WARM ADVECTING INTO THE REGION ON
FRIDAY AND SATURDAY AHEAD OF THE NEXT ALBERTA CLIPPER. A TIGHTENING
PRESSURE GRADIENT ON FRIDAY WILL LEAD TO BREEZY CONDITIONS INTO
SATURDAY. SATURDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH
TEMPERATURES CLOSER TO NORMALS IN THE UPPER 20S TO LOWER 30S.
CLOUDS WILL BEGIN OVERSPREADING THE REGION ON SATURDAY AHEAD OF A
CLIPPER THAT WILL DRAG A STRONG COLD FRONT ACROSS THE REGION
SATURDAY AFTERNOON INTO THE EVENING. THE BETTER DYNAMICS AND
MOISTURE WITH THIS SYSTEM WILL BE ALONG AND BEHIND THE FRONT. THE
GFS IS QUICKER WITH THE SYSTEM AND ENDS PRECIPITATION BY 06 UTC ON
SUNDAY WHILE THE ECMWF IS WETTER AND CONTINUES THE PRECIPITATION
THROUGH 18 UTC ON SUNDAY. HAVE A COMBINATION OF THE TWO SOLUTIONS
GOING INTO SUNDAY WITH SOME LINGERING SNOW THROUGH 18 UTC.
VERY STRONG COLD ADVECTION WILL BE ONGOING SUNDAY NIGHT INTO MONDAY
WITH A STRONG 1040 TO 1050 MB SURFACE HIGH BUILDING SOUTHEASTWARD
INTO MONTANA. THE GFS AND ECMWF SHOW THE SURFACE HIGH MODERATING TO
BETWEEN 1030 TO 1040 MB BY TUESDAY MORNING ACROSS IOWA. 850
TEMPERATURES WILL HAVE COOLED TO -20*C TO -30*C BY 12 UTC ON MONDAY
AND FURTHER COOLING TO -24*C TO -30*C BY 12 UTC ON TUESDAY. THESE
TEMPERATURES ARE 2 TO 3 STANDARD DEVIATIONS BELOW THE MEAN FOR
JANUARY SO THIS WILL BE AN UNUSUALLY COLD AIRMASS BUILDING INTO THE
REGION EARLY NEXT WEEK. SURFACE TEMPERATURES MAY REMAIN BELOW ZERO
SUNDAY NIGHT THROUGH TUESDAY. SOME OF THIS COLD AIR MAY BE HIGHLY
DEPENDENT ON THE SNOWPACK TO OUR NORTH. AFTER TUESDAY...HIGH
PRESSURE WILL SHIFT EASTWARD ALLOWING FOR A RETURN TO MORE MODERATE
AIR FOR THE MIDDLE OF NEXT WEEK. IN ADDITION TO THE COLD AIR THE
PRESSURE GRADIENT WILL BE TIGHT ACROSS THE REGION ON MONDAY SO
ANOTHER BREEZY OVERNIGHT WHICH WILL MAKE TEMPERATURES FEEL MUCH
COLDER THAN THE AIR. COUSINS
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 623 PM CST WED JAN 1 2014
CONDITIONS WILL CONTINUE TO IMPROVE SOUTH OF I80 AS THE SNOW
PUSHES SOUTHEAST. BY LATE THIS EVENING EXPECT VFR CONDITIONS AT
ALL OF THE TAF SITES. MODELS ARE SHOWING SOME LOW LEVEL MOISTURE
REMAINING OVER THE AREA THROUGH MID-DAY THURSDAY SO SOME PATCHY
MVFR CIGS CANNOT BE RULED OUT TONIGHT AND THURSDAY MORNING.
&&
.CLIMATE...
ISSUED AT 315 PM CST WED JAN 1 2014
RECORD LOWS FOR JANUARY 2...
MOLINE.........-27 IN 1979
CEDAR RAPIDS...-19 IN 1979
DUBUQUE........-22 IN 1879
BURLINGTON.....-15 IN 1979
RECORD LOWS FOR JANUARY 3...
MOLINE.........-16 IN 1887
CEDAR RAPIDS...-15 IN 1919
DUBUQUE........-24 IN 1887
BURLINGTON.....-16 IN 1919
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR BENTON-BUCHANAN-CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-
JACKSON-JEFFERSON-JOHNSON-JONES-KEOKUK-LINN-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR DES
MOINES-HENRY IA-JEFFERSON-LEE-VAN BUREN.
IL...WIND CHILL ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST THURSDAY
FOR JO DAVIESS.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR BUREAU-
HANCOCK-HENDERSON-HENRY IL-MCDONOUGH-MERCER-PUTNAM-WARREN.
MO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR CLARK-
SCOTLAND.
&&
$$
UPDATE...DLF
SHORT TERM...12
LONG TERM...COUSINS
AVIATION...DLF
CLIMATE...COUSINS
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
306 PM CST TUE DEC 31 2013
.SYNOPSIS...
ISSUED AT 304 PM CST TUE DEC 31 2013
THE NARROW AXIS OF MODERATE SNOW IS POSITIONED IN THE NORTHERN 1/4
OF THE CWA BY MID AFTERNOON. BY OBSERVATIONS...WEBCAMS AND
CALLS...THERE HAS BEEN ROUGHLY 1 INCH PER HOUR FALLING IN THIS AREA
SINCE AROUND NOON. FARTHER SOUTH...A STRONG STATIONARY FRONT IS
LOCATED NEAR THE IOWA/MISSOURI BORDER...EASILY SEEN IN OBS THAT
RANGE FROM THE MID 30S TO THE MID TEENS IN A FEW TENS OF MILES IN
OUR SOUTH. STRONG FRONTOGENESIS IS CAUSING THE SNOW TO THE NORTH OF
THE FRONT...AND THIS TYPE OF FORCING WILL ALSO DOMINATE TOMORROW.
&&
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 304 PM CST TUE DEC 31 2013
FRONTOGENESIS WILL CONTINUE THROUGH AROUND 9 PM IN THE NORTH...THEN
WILL SLOWLY SETTLE SOUTH IN A WEAKENING FASHION. THIS SHOULD LEAD TO
LIGHTER SNOWS AFTER MID EVENING...BUT WITH 3 TO 5 ALREADY ON THE
GROUND IN THE NORTH...WILL CONTINUE THE ADVISORY THROUGH 12Z.
FARTHER SOUTH ALONG THE HIGHWAY 30 TO INTERSTATE 80 CORRIDORS...THE
BEST CHANCE FOR MEASUREABLE SNOW WILL HOLD OFF UNTIL THIS FORCING
ARRIVES FROM THE NORTH MID EVENING. OVERNIGHT SNOW TOTALS SHOULD BE
1 TO 2 INCHES NORTHEAST TO AN INCH OR INTO THE CENTRAL CWA.
ANOTHER...ARGUABLY STRONGER ROUND OF FRONTOGENESIS ARRIVES EARLY
WEDNESDAY MORNING...LIKELY CONTINUING ALL DAY AS IS GRADUALLY
SETTLES SOUTH. THIS TOO SHOULD HAVE SNOW RATIOS OF 15 TO 20:1...AND
AMOUNTS OF SNOW WILL BE RATHER FLUFFY. THE NAM AND GEM BOTH CARRIED
THIS IDEA IN PAST RUNS AND CURRENT...BUT IS NOW SUPPORTED BY THE 12Z
GFS...12Z ECMWF...12Z UKMET...NMM EAST...SPC WRF AND LAST HOURS OF
THE RAP RUNS. THUS...WE HAVE HIGH ENOUGH CONFIDENCE ISSUE A WINTER
WEATHER ADVISORY SNOW OVER CENTRAL CWA FROM 6 AM WEDNESDAY TO 6 PM
WEDNESDAY. WE ARE GENERALLY LOOKING FOR 3 TO 4 INCHES OF SNOW IN A 6
HOUR WINDOW OF TIME. THIS SUPPORTS ADVISORY ISSUANCE. SHOULD THE
MESOCALE MODELS BE CORRECT ON THE STRENGTH OF FORCING...WE COULD BE
LOOKING AT AMOUNTS WITHIN THE BAND FROM OTTUMWA TO THE QUAD CITIES
IN THE 4 TO 7 INCH RANGE. HOWEVER...CONFIDENCE IS HIGHER FOR TOTALS
IN THE 3 TO 4 INCH RANGE. TEMPERATURES WILL BE VERY COLD AGAIN
TONIGHT AND WEDNESDAY...AS WINDS FROM THE NORTHEAST DRAW IN THE SAME
AIRMASS WE HAD YESTERDAY. THE WARMTH IN THE FAR SOUTH JUST IS NOT
COMING OUR WAY IN THIS FORECAST.
ERVIN
.LONG TERM...(WEDNESDAY NIGHT THROUGH NEXT TUESDAY)
ISSUED AT 304 PM CST TUE DEC 31 2013
WEDNESDAY NIGHT AND THURSDAY...LATEST 12Z RUN MODELS HAVE COME
AROUND WITH RESPECT TO EXTENT OF FORCING ACRS AND SOUTH OF THE CWA
WED EVENING AS UPPER VORT PIVOTS IN TROF BASE ACRS SOUTHEAST IA.
DECENT ELEVATED FRONTOGENESIS RIBBON ALONG AND NORTH OF CENTRAL IL
INTO SOUTHEASTERN PLAINS SFC FRONT...ALONG WITH ISENTROPIC LIFT
ANALYSIS ON 285K SFC SHOULD LAY DOWN AN ADDITIONAL 0.5 UP TO OVER AN
INCH IN THE SOUTHEASTERN QUARTER OF THE DVN CWA FROM 00Z-03Z OR SO
AND WORRIED IT MAY BE MORE TAKING INTO ACCOUNT USED 17:1 OR
HIGHER LSR/S. BUT FOR NOW WILL ALLOW THE ADVISORY END AT 00Z
COORDINATING WITH THE ABOVE SHORT TERM DISCUSSION. THUS EVEN THE
HWY 34 CORRIDOR AND AREAS TO THE SOUTH MAY END UP WITH 1-3 INCHES BY
MIDNIGHT THU NIGHT TAKING INTO ACCOUNT SNOWFALL LATE WED AFTERNOON
AND INTO THE EVENING. THEN AS L/W PHASING PROCESS SHIFTS OFF TO THE
EAST/SOUTHEAST OF THE REGION...ANOTHER BOUT OR INCOMING ARCTIC
HIGH PRESSURE TO DEAL WITH...WITH THE PRESSURE GRADIENT INDUCING OR
MAINTAINING 7-11KT WINDS INTO THU MORNING. SIDING WITH THE COOLER
MAV BUT GOING ABOVE IT TAKING INTO ACCOUNT MIXING WINDS AND
LINGERING CLOUD COVER...STILL MANY SUBZERO READINGS WILL OCCUR OVER
THE NORTHWESTERN THIRD OF THE CWA IN DEEPER SNOWPACK...MAY NOT BE
GOING COLD ENOUGH ALONG THE I80 CORRIDOR. THESE COLD AMBIENT TEMPS
WHEN COMBINED WITH THE WINDS WILL PROBABLY MAKE FOR WIND CHILL
ADVISORY CRITERIA EARLY THU MORNING. BOTH THE 12Z GFS AND ECMWF
SLIDE MAIN SFC RIDGE AXIS ACRS CENTRAL INTO EASTERN IA BY 00Z FRI
MAKING FOR SOME CLOUD CLEAR OUT AS THU PROGRESSES. HIGHS ONLY TO
RECOVER INTO THE SINGLE DIGITS ABOVE ZERO IN MUCH OF THE CWA. THEN
THE STAGE WILL BE SET FOR A NEAR RECORD COLD ARCTIC NIGHT THU NIGHT
INTO FRI MORNING AND AGAIN WILL SIDE WITH THE MUCH COLDER MAV MOS
GUIDANCE VALUES. CID MAY HAVE THE BEST CHC OF BREAKING IT/S RECORD
FOR THE 3RD OF JAN BEING -15F. ALTHOUGH THE WINDS SHOULD BE
DECOUPLING...EVEN 5 KT WINDS WILL PRODUCE SOLID WIND CHILL ADVISORY
AND POSSIBLE EVEN SOME WIND CHILL WARNING CRITERIA LATE THU NIGHT
AFTER 06Z INTO MID FRI MORNING.
FRIDAY THROUGH SUNDAY...ARCTIC RIDGE PROGGED TO MIGRATE OFF TO THE
EAST ON FRI WHICH WILL ALLOW RATHER ROBUST LLVL SOUTHERLY RETURN FLOW
TO BRING ABOUT A SUBSTANTIAL SFC TEMP MODERATION. AFTER SUCH A
FRIGID START TO THE MORNING...12 HR HIGHS WILL OCCUR AT AROUND 00Z
SAT...AND 24 HR HIGHS PROBABLY THROUGH MIDNIGHT FRI NIGHT. THE
LATEST RUN MEDIUM RANGE SOLUTIONS THEN SUGGEST TEMPORARY
FLATTENING FLOW PATTERN TO USHER A MORE VIGOROUS WAVE ACRS THE
NORTHERN PLAINS INTO THE NORTHWESTERN GRT LKS INTO SAT MORNING. WAA
SHIELD OF PRECIP ASSOCIATED WITH THIS FEATURE SHOULD STAY TO THE
NORTH OF THE CWA FRI NIGHT. DISCREPANCIES POP UP WITH THIS SYSTEM/S
SFC FROPA THROUGH THE CWA BY SAT AFTERNOON. THE 12Z ECMWF MAINTAINS
A DRY FROPA...WHILE THE 12Z GFS HAS TRENDED WETTER WITH POST FRONTAL
BAN OF SNOWS ACRS AT LEAST THE NORTHWESTERN THIRD OF THE CWA SAT
AFTERNOON...POSSIBLY 1-3 INCHES OF SNOW ACCUM BY EARLY SAT
EVENING. WILL KEEP SLIGHT CHC TO CHC POPS GOING FOE EXPECTING THE
ECMWF TO TREND WETTER AND PRODUCE SOME PRECIP IN THE CWA. BEFORE
FROPA...MILDEST DAY IN THE PERIOD SAT WITH HIGHS IN THE MID 20S IN
THE NORTH...TO THE LOWER 30S IN THE SOUTH. WOULD BE WARMER IF IT
WERE NOT FOR THE SNOWPACK. RE-ESTABLISHING L/W TROF BASE SOMEWHERE
ACRS THE MID CONUS AND PROBABLY WEST OF OF THE MS RVR VALLEY...AND
WAVE ENERGY EJECTING OUT OF THE DEEP PLAINS LATE SAT NIGHT AND INTO
SUNDAY WILL BE A WINDOW TO WATCH FOR FURTHER NORTHWEST PULL OUT
PATHWAY. RIGHT NOW THE LATEST GFS/ECMWF AND ENSEMBLES JUST CLIP THE
FAR SOUTHERN AND SOUTHEASTERN CWA WITH 1-2+ INCHES BY SUNDAY
AFTERNOON. NORTHERLY LLVL COLD CONVEYOR WRAPPING IN AROUND THIS
FEATURE TO BRING ABOUT COLDER TEMPS AGAIN SAT NIGHT AND SUNDAY.
THEN BULK OF THE MEDIUM RANGE MODELS CONTINUE TO ADVERTISE A HUGELY
NEGATIVE ANOMALY IN THEIR L/W TROF FORMATION ACRS THE UPPER AND MID
MS RVR VALLEY BY 12Z MON. SEEMS THE POLAR VORTEX GYRATING ACRS THE
SOUTHERN HUDSON BAY REGION REMAINS TRAPPED AND ACTING AS A TYPE OF
BLOCK FOR RIDGING OFF THE COASTS.
NEXT MONDAY AND TUESDAY...THE 12Z GFS HAD AN INCREDIBLY INTENSE SFC
HIGH OF 1058 MB INTO NORTH CENTRAL MT BY 12Z MON...WITH THE RIDGE
CENTER THEN MODERATING TO THE LOWER 1040S AS IT SLIDES SOUTHEASTWARD
ACRS THE REGION FOR MON NIGHT INTO TUE MORNING. THE EURO NOT QUITE
SO STRONG WITH A 1045 MB HIGH...BUT THEY BOTH ADVERTISE ARCTIC DOME
OF AIR TO SURGE ACRS THE CWA/FROPA AS MONDAY PROGRESSES. SHARPLY
DROPPING TEMPS...AND IF THE MODEL PROGGED -26C TO -28C H85 MB
AIRMASS VERIFIES AND MAKE IT ACRS THE CWA...COULD BE SOME -15 TO
-25F LOW TEMPS BY TUE MORNING IN PORTIONS OF THE DVN CWA. INCREDIBLE
COLD. WILL IT MODERATE THEN MID TO LATE NEXT WEEK AS BULK OF THE
MEDIUM RANGE SOLUTIONS SUGGEST...OR THEY CONTINUE TO MISHANDLE SUCH
A NEG ANOMALY REGIME AND OPEN THE REGION/MIDWEST BACK TO MORE ARCTIC
DUMPS AFTER NEXT WED. ..12..
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1140 AM CST TUE DEC 31 2013
A CHALLENGING WINTER STORM WILL BRING SNOW TO NORTHERN IOWA AND
NORTHERN ILLINOIS THIS AFTERNOON THROUGH WEDNESDAY AFTERNOON...AND
TO THE REMAINDER OF THE AREA LATE THIS EVENING THROUGH WEDNESDAY
EVENING. THIS WILL BE DOMINATED BY MVFR CIGS AROUND 1200 TO 2500
FT...AND IFR VISIBILITY AROUND 1 TO 3 MILES IN SNOW AND FOG. SOME
PERIODS OF LIFR ARE POSSIBLE TODAY AND THIS EVENING AT DBQ WHERE
THE HEAVIEST SNOW SHOULD OCCUR. ANOTHER PERIOD OF MODERATE SNOW IS
POSSIBLE AT CID AND MLI WEDNESDAY DURING THE DAY...AND THEN AT
BURLINGTON WEDNESDAY LATE MORNING AND AFTERNOON. THIS WILL BE
BETTER DEFINED IN FUTURE TAFS AS WE APPROACH THIS EVENT. WINDS
WILL BE LIGHT INITIALLY...BUT SHOULD BECOME NORTHEASTERLY AT ALL
SITES LATE THIS AFTERNOON THROUGH WEDNESDAY.
ERVIN
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WINTER WEATHER ADVISORY UNTIL 6 AM CST WEDNESDAY FOR BENTON-
BUCHANAN-DELAWARE-DUBUQUE-JACKSON-JONES-LINN.
WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST WEDNESDAY FOR
CEDAR-DES MOINES-HENRY IA-IOWA-JEFFERSON-JOHNSON-KEOKUK-
LOUISA-MUSCATINE-SCOTT-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR CLINTON.
IL...WINTER WEATHER ADVISORY UNTIL 6 AM CST WEDNESDAY FOR JO DAVIESS-
STEPHENSON.
WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM CST WEDNESDAY FOR
BUREAU-HENRY IL-MERCER-PUTNAM-ROCK ISLAND.
WINTER WEATHER ADVISORY UNTIL 6 PM CST WEDNESDAY FOR CARROLL-
WHITESIDE.
MO...NONE.
&&
$$
SYNOPSIS...ERVIN
SHORT TERM...ERVIN
LONG TERM...12
AVIATION...ERVIN
AREA FORECAST DISCUSSION
NWS GRAY ME
1023 AM EST TUE DEC 31 2013
.SYNOPSIS...
A COLD FRONT WILL CROSS THE CROSS THE AREA EARLY TONIGHT AND
REINFORCE THE ARCTIC AIR IN THE THE REGION THROUGH NEW YEARS DAY.
LOW PRESSURE WILL PASS TO THE SOUTH OF NEW ENGLAND THURSDAY AND
WILL LIKELY DELIVER ACCUMULATING SNOWFALL TO THE AREA THURSDAY AND
THURSDAY NIGHT. VERY COLD TEMPERATURES ARE EXPECTED TO BE A BIG
THEME FOR THE REST OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1015 AM...A QUICK UPDATE TO INTRODUCE SOME FLURRIES ALONG THE
ME COAST TODAY...AS WEAK OCEAN EFFECT IS PRODUCING SOME LIGHT
ECHOES INTO YORK AND CUMBERLAND COUNTIES. STILL NO REPORTS OF ANY
SNOW...BUT WILL LKLY SEE SOME SNOW FLAKES IN THE AIR AT THE VERY
LEAST. BOTH RAP AND LOCAL WRF PICKING UP ON THIS...AND SHIFT THIS
FEATURE EWD THIS AFTERNOON AS THE SW FLOW AHEAD OF APPROACHING
COLD FRONT PICKS UP AND MOVES EWD AS WELL. PREV FORECAST OF COLD
FROPA LATE TODAY INTO THIS EVENING STILL ON TRACK...WITH SOME SCT
SHSN DEVELOPING...MAINLY IN THE MTNS...AND PERHAPS A DUSTING TO AN
INCH OF LIGHT FLUFFY SNOW IN SOME SPOTS OF THE WRN ME MTNS AND
HIGHER TERRAIN OF NH.
PREV DISC...
1025 MILLIBAR HIGH WILL BUILD EAST ACROSS THE AREA THIS MORNING. A
1014 MILLIBAR LOW OVER THE UPPER GREAT LAKES AND ASSOCIATED UPPER
IMPULSE WILL RACE EAST AND SPREAD SOME CLOUDS AND SCATTERED SNOW
SHOWERS INTO WESTERN AND NORTHERN SECTIONS TOWARDS DUSK. AFTER A
VERY CHILLY START...TEMPERATURES WILL STRUGGLE TO 5 TO 10 ABOVE
ACROSS THE MOUNTAINS WITH ONLY TEENS FOR THE REMAINDER...CLOSE TO
15 DEGREES BELOW AVERAGE FOR THE DATE. CHILL WILL NOT BE AS BIG A
FACTOR TODAY AS THE WINDS CONTINUE TO DIMINISH UNDER BUILDING HIGH
WITH WIND CHILL ADVISORY BEING ALLOWED TO EXPIRE ON SCHEDULE AT 12Z,
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
THE WEAK LOW TRAVERSES THE AREA EARLY TONIGHT WITH TRAILING COLD
FRONT PRESSING SOUTHWARD ACROSS THE REGION. WE`LL SEE A FEW CLOUDS
AS WELL AS SNOW SHOWERS WITH THIS SYSTEM WITH SOME LIGHT SNOW
ACCUMULATION POSSIBLE FOR THE HIGHER TERRAIN. LOW TEMPERATURES
SHOULD BE A FEW DEGREES WARMER THEN TONIGHT GIVEN THE EXPECTED
CLOUD COVER. A MOSTLY SUNNY AND COLD START FOR THE NEW YEAR AS
ARCTIC HIGH PRESSURE NOSES SOUTHEASTWARD INTO THE REGION.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE MAIN WEATHER CONCERNS DURING THIS PERIOD WILL BE THE
COMBINATION OF SNOW AND VERY COLD TEMPERATURES THURSDAY AND
FRIDAY. A STRONG NORTHERN STREAM SHORT WAVE TROUGH WILL MOVE
EASTWARD FROM THE MIDWEST TO THE GREAT LAKES WEDNESDAY NIGHT AND
THURSDAY. MOISTURE STREAMING EASTWARD WELL IN ADVANCE OF THE
POSITIVELY TILTED TROUGH AXIS WILL MOVE INTO OUR REGION LATE WED
NIGHT AND EARLY ON THURSDAY. THIS COUPLED WITH A BROAD AREA OF
ISENTROPIC LIFT WILL AID IN LIGHT SNOW BREAKING OUT ACROSS
SOUTHERN ZONES LATER WED NIGHT OR EARLY THURS MORNING...WHICH
SHOULD THEN SPREAD NORTHWARD AS THE DAY PROGRESSES.
AT THIS TIME IT DOES NOT LOOK LIKE THE TROUGH WILL AMPLIFY FAST
ENOUGH AND LINK UP WITH A GOOD AMOUNT OF SOUTHERN STREAM MOISTURE
TO ALLOW FOR A SIGNIFICANT SNOWSTORM FOR OUR AREA. AT THIS TIME IT
LOOKS LIKE WE/LL BE DEALING WITH OCCASIONAL LIGHT SNOW THAT WILL
ADD UP OVER THE COURSE OF 24-36 HOURS OR SO. THE BEST FORCING FOR
ASCENT WILL BE ACROSS SOUTHERNMOST ZONES...SO WE EXPECT SOUTHERN
NH AND PERHAPS SOUTHERNMOST MAINE TO PICK UP THE MOST SNOW OUT OF
THIS...WHICH MAY ADD UP TO 5 TO 10 INCHES OVER THAT RELATIVELY
LONG DURATION. SNOWFALL AMOUNTS WILL TAPER OFF RATHER QUICKLY AS
ONE HEADS FURTHER NORTH...WITH THE WESTERN ME MOUNTAINS AND
ADJACENT NORTHERNMOST NH LIKELY NOT PICKING UP MUCH IN THE WAY OF
ACCUMS. IN FACT...IT/S POSSIBLE THAT LOCATIONS IN THE PITTSBURG NH
TO JACKMAN ME CORRIDOR DON/T SEE MORE THAN A FEW FLURRIES. THE
SYSTEM LOOKS TO MOVE AWAY LATE THURSDAY NIGHT OR EARLY
FRIDAY...AND THIS WILL END THE THREAT OF SNOW FROM WEST TO EAST THEN.
THE MAIN ISSUE FOR THURS AND FRI WILL BE THE COLD TEMPERATURES AND
WIND CHILL VALUES. HIGHS THURS WILL RANGE FROM THE SINGLE NUMBERS
BELOW ZERO IN THE MOUNTAINS...TO SINGLE DIGITS ABOVE ZERO CLOSER TO
THE COAST. THE WARMEST READINGS WILL BE IN SOUTHERN NH WHERE HIGHS
MAY TOP OUT IN THE MID TEENS. STRONG HIGH PRESSURE WILL BE
SITUATED ACROSS SOUTHERN QUEBEC THURSDAY...AND THIS COUPLED WITH
THE LOW PRESSURE SYSTEM PASSING TO OUR SOUTH WILL RESULT IN A
TIGHTENING PRESSURE GRADIENT. WINDS SHOULD INCREASE AS THURS
PROGRESSES...WITH MOST MOMENTUM TRANSFER TOOLS YIELDING GUSTS
20-30 MPH THURS AFTERNOON AND NIGHT. THEREFORE...WE ARE LOOKING AT
VERY LOW WIND CHILL VALUES THURS THROUGH FRIDAY...WHICH MAY DROP
TO DANGEROUS LEVELS AT TIMES. WOULD NOT BE SURPRISED IF FORECAST
TEMPS THURS AFTN WILL HAVE TO BE DROPPED A COUPLE OF DEGREES
FURTHER BASED ON THE STRENGTH OF THE HIGH TO THE NORTH. SO IN A
NUTSHELL...REALLY COLD STUFF THURS AND FRI.
THEREAFTER...MODEL SOLUTIONS DIFFER WILDLY FOR EARLY NEXT
WEEK...WITH THE 00Z ECMWF STILL BRINGING AN INTENSE LOW PRESSURE
SYSTEM NORTHWARD THROUGH UPSTATE NY AND INTO QUEBEC MONDAY. THIS
SOLUTION IS AN OUTLIER AT THIS POINT...BUT THERE/S SOME
CONSISTENCY THERE...SO WE/LL HAVE TO CONTINUE TO MONITOR.
&&
.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
SHORT TERM...VFR CONDITIONS EXPECTED TO PREVAIL INTO WED. A WEAK
LOW CROSSING THE AREA THIS AFTERNOON AND EVENING MAY BRING AREAS
OF MVFR OR LOWER CONDITIONS...ESPECIALLY ACROSS THE N/MT AREAS AND
OVER WRN NH...IMPACTING HIE AND LEB TAF SITES.
LONG TERM...FLIGHT RESTRICTIONS EXPECTED THU INTO FRI IN SNOW AND
BLOWING SNOW...WITH THE BETTER FOR LOWER RESTRICTIONS ALONG THE
COAST.
&&
.MARINE...
SHORT TERM /TONIGHT THROUGH WEDNESDAY/...WILL ALLOW SCA TO EXPIRE
WITH NEW MARINE PACKAGE AT 3 AM. WINDS AND SEAS WILL REMAIN BELOW
SCA UNTIL WEDNESDAY MORNING...WHEN I EXPECT THEY`LL INCREASE
QUICKLY TO SCA THRESHOLD FOLLOWING PASSAGE OF ARCTIC COLD FRONT.
LONG TERM...GALES POSSIBLE...IF NOT LIKELY...ON THE WATERS LATE
THURS AND FRI AS LOW PRESSURE PASSING TO THE SOUTH OF NEW ENGLAND
COUPLES WITH STRONG HIGH PRESSURE OVER QUEBEC. FREEZING SPRAY WILL
BE LIKELY AS WELL AS VERY COLD TEMPERATURES ADVECT OVER THE WATERS.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM EST
WEDNESDAY FOR ANZ150>152-154.
&&
$$
SYNOPSIS...
NEAR TERM...CEMPA
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
235 AM EST TUE DEC 31 2013
.SYNOPSIS...
WEAK LOW PRESSURE MOVES EAST ACROSS THE CAROLINAS TONIGHT...THEN
PUSHES OFFSHORE TUESDAY MORNING. HIGH PRESSURE BUILDS BACK OVER
THE AREA TUESDAY AFTERNOON THROUGH WEDNESDAY. LOW PRESSURE MOVES
THROUGH THE OHIO AND TENNESSEE VALLEYS WEDNESDAY NIGHT AND
THURSDAY...BEFORE CROSSING THE REGION THURSDAY NIGHT AND FRIDAY.
&&
.NEAR TERM /THROUGH TODAY/...
QUICK LOOK AT THE 00Z NAM / HRRR AND 21Z SREF ALL SUGGEST PCPN WILL
HAVE A TUFF TIME GETTING TO FAR NORTH OVERNIGHT AS THE WEAK S/W
MOVES EAST ACROSS THE CAROLINAS. IN ADDITION...2M TEMPS SUGGEST
READINGS HOVER JUST ABOVE FREEZING OVER MOST OF SRN VA/NE NC. SO
MADE SOME ADDITIONAL CHANGES TO OVERNIGHT GRIDS BASED ON THE LATEST
DATA. KEPT A NARROW BAND OF A RAIN/SNOW SHOWER MIX ON NORTHERN
FRINGES OF THE PCPN SHIELD (FVX-PTB-JGG-MVF LINE) WITH JUST RAIN
OVER SOUTHERN / SERN VA AND NE NC COUNTIES. BUMPED UP POPS A BIT
ACROSS THE SOUTHERN AREAS TO 30% WITH .01 QPF AT THE MOST. CAA
ACROSS NRN MOST COUNTIES WILL ALLOW TEMPS TO DROP INTO THE U20S BY
12Z...RANGING INTO THE L-M30S SOUTHERN HALF OF FA.
PVS DSCN:
RAPIDLY DECREASING CLOUDS EXPECTED TUESDAY BEHIND SHORTWAVE WILL
ALLOW FOR A SUNNY/MOSTLY SUNNY DAY...AS HIGH PRESSURE BUILDS INTO
THE AREA. MAX TEMPS WILL BE SLIGHTLY COOLER THAN TODAY. HIGH TEMPS
IN THE MID TO UPR 40S NORTH...LOWER 50S NE NC/ EXTREME SRN VA.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
MOSTLY CLR AND SEASONABLY COLD TUESDAY NIGHT...WITH MIN TEMPS MOSTLY
IN THE 20S. SUNNY/MOSTLY SUNNY WEDNESDAY...WITH MAX TEMPS MID 40S
FAR NORTH...LOWER 50S SOUTH THIRD.
HIGH PRESSURE MOVES OFFSHORE WEDNESDAY NIGHT/THU...AS COMPLEX LOW
PRESSURE BEGINS DEVELOPING ACROSS MS VLY. THIS SYSTEM CONTINUES
ORGANIZING...AND MOVING ENEWD TOWARD THE REGION THU. GFS/ECMWF NOW
SUGGEST MORE WIDESPREAD PRECIP ACROSS THE AREA THU AFTERNOON...
CONTINUING INTO THU NIGHT. NAM MUCH DRIER/WEAKER WITH THIS
SYSTEM...AS IT DELAYS ANY SIFNIFICANT DEEPENING OF THE LOW UNTIL
AFTER 00Z FRIDAY. TEMPS ON THURSDAY IN THE 40S NORTH HALF TO THE
50-55 RANGE SE WILL KEEP ALL PRECIP LIQUID THROUGH 00Z FRI.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THE LONG TERM PERIOD BEGINS THURSDAY EVENING WITH A COMPLEX LOW
PRESSURE SYSTEM IN VICINITY OF THE MID ATLANTIC STATES. MODELS ARE
BEGINNING TO CONVERGE ON A SOLUTION WHICH HAS THE MAIN LOW PRESSURE
DEVELOPING OVER THE TENNESSEE VALLEY AND MOVING THROUGH THE
CAROLINAS. THIS WOULD BRING THE POTENTIAL FOR WIDESPREAD PCPN
ACROSS THE AREA ON THURSDAY NIGHT. KEPT POPS IN THE CHC RANGE FOR
NOW UNTIL MODELS BECOME MORE CONSISTENT.
AFTER ABOVE NORMAL TEMPERATURES THURSDAY...TEMPERATURES FALL ON
THURSDAY NIGHT...WHICH WOULD CHANGE PCPN FROM RAIN TO SNOW FROM
NORTH TO SOUTH. PCPN MAY CHANGE TO ALL SNOW BY SHORTLY AFTER
MIDNIGHT N OF A LINE FROM EMPORIA TO WAKEFIELD TO WALLOPS ISLAND. BY
THAT TIME...DRYING MAY END OR DIMINISH PCPN ACROSS SOUTHERN AND
WESTERN PORTIONS OF THE AREA. IT APPEARS THAT THE GREATEST POTENTIAL
FOR ACCUMULATING SNOWFALL WILL BE ON THE LOWER MD EASTERN SHORE.
PCPN SHOULD END FROM W TO E EARLY FRIDAY BUT MAY CONTINUE INTO THE
AFTN ON THE EASTERN SHORE. IT IS TOO EARLY TO SPECULATE ON
ADDITIONAL DETAILS THIS FAR OUT.
THE LOW PRESSURE SYSTEM MOVES QUICKLY OUT TO SEA ON FRIDAY AND
INTENSIFIES RAPIDLY (BOMBS) SOUTHEAST OF NEW ENGLAND. THIS WILL
DRIVE ARCTIC AIR INTO THE AREA LATE FRIDAY AND FRIDAY NIGHT.
TEMPERATURES SATURDAY MORNING ON THE LOWER EASTERN SHORE AND
NORTHERN PORTIONS OF CENTRAL VIRGINIA MAY DROP INTO THE MID TO UPR
TEENS... ESPECIALLY WHERE THERE IS SNOW COVER.
HIGH PRESSURE SETTLES OVER THE AREA SATURDAY BEFORE MOVING OFF TO
THE EAST. TEMPERATURES GO BACK TO ABOVE NORMAL LEVELS BY SUNDAY
AHEAD OF THE NEXT COLD FRONT WHICH IS CURRENTLY PROGGED TO MOVE
THROUGH EARLY MONDAY WITH A CHC FOR SCATTERED SHOWERS. TEMPERATURES
DROP ONCE AGAIN EARLY NEXT WEEK AS A STRONG ARCTIC HIGH PRESSURE
OVER THE PLAINS STATES BEGINS TO BUILD TOWARD THE MID ATLANTIC
STATES.
HIGH TEMPERATURES MAINLY IN THE 30S FRIDAY AND SATURDAY WARM TO THE
UPR 40S NORTH TO 50S SOUTH SUNDAY AND MAINLY 50S MONDAY. LOWS FRIDAY
MORNING MID 20S TO LWR 30S LOWER TO MID TEENS TO LWR 20S SATURDAY
MORNING AND BY MONDAY MORNING IN THE 40S.
&&
.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
VFR CONDS CONT TO PREVAIL AT THE TAF SITES ALTHOUGH WITH CIGS
AROUND 035-060 FT. WINDS ARE MOSTLY N-NE LESS THAN 10 KT. A WEAK
DISTURBANCE WILL MOVE NE ALONG A STRNY FRONT ACROSS NC TOWARDS
THE SE VA COAST EARLY THIS MORNING. THIS SYS IS EXPECTED TO
PRODUCE SOME -RA AND PSBL MVFR CIGS FOR ECG AND ORF. THE SYS WILL
CLEAR THE COAST BY SUNRISE AND SKIES WILL BECOME MOSTLY CLR BY
MID TO LATE MORNING.
HIGH PRESSURE BUILDS BACK IN LATE TODAY AND WEDNESDAY. THE NEXT
WEATHER SYSTEM AFFECTS THE AREA LATE THURSDAY INTO FRIDAY. EXPECT
AREAS OF RAIN...POSSIBLY TURNING TO LIGHT SNOW THURSDAY NIGHT
BEFORE ENDING. THERE IS UNCERTAINTY IN THE DETAILS BUT FOR NOW
HAVE A CHC FOR SNOW FRIDAY AT SBY. PERIODS OF MVFR/IFR CAN BE
EXPECTED DURING THIS PERIOD.
ARCTIC HIGH PRESSURE BUILDS INTO THE REGION LATE FRIDAY AND SATURDAY
WITH MAINLY CLEAR SKIES.
&&
.MARINE...
CDFNT POISED TO BE S AND E OF THE WTRS THIS EVE. INCRSD WINDSPEEDS
FM THE NNW MAKING THEIR WAY DN FM THE NRN PORTION OF THE
BAY...WHERE AT LEAST GUSTS TO LO END SCA HAVE BEEN NOTED. WILL
GIVE IT SOME TIME FOR SPEEDS TO INCRS HERE AS SFC HI PRES BEHIND
THE FNT MOVES BY JUST N OF THE WTRS THROUGH THIS EVE/ERY OVRNGT
PDS. WILL HOLD ONTO SCAS FOR THE BAY/LWR JAMES RVR BEFORE/THROUGH
MDNGT. LO LVL CAA WANES AFT MDNGT. SFC HI PRES WEAKENS OVR THE NE
CONUS BY TUE AFTN...RESULTING IN WNDS BECOMING MSTLY W. A SECOND
SURGE IN SPEEDS (SHORTLIVED) XPCD LT TUE AFTN/EVE BUT WILL KEEP
CONDS BLO SCA FOR NOW.
SFC HI PRES SLIDES ACRS THE WTRS WED...THEN OFFSHORE BY WED
NGT...W/ WNDS BECOMING MSTLY S (SPDS STAYING BLO 15 KT). MODEL
UNCERTAINTY AFFECTS THE CONFIDENCE OF THE FORECAST LT IN THE WK.
ANOTHER COASTAL STORM APPEARS TO IMPACT THE WATERS IN THE THURS-
FRI MORNING TIMEFRAME. 12Z/30 GFS/ECMWF BOTH DVLPG SGFNT CSTL LO
PRES E OF THE DELMARVA BY FRI MRNG. WILL HOLD OFF ON STRONG CAA
(AND SHARP INCRS IN WINDSPEEDS AND SEA/WAVE HGTS) POST STORM DVLPG
DURG FRI (PSBL GALES?)...WHICH WANES OVR THE WKND.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...MPR
NEAR TERM...MPR
SHORT TERM...WRS
LONG TERM...LSA
AVIATION...MAS/JEF/LSA
MARINE...ALB
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1226 PM EST TUE DEC 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EST TUE DEC 31 2013
WV IMAGERY AND RUC ANALYSIS INDICATED CYCLONIC WNW MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES AROUND THE POLAR VORTEX LOCATED OVER
SRN HUDSON BAY. A SHORTWAVE TROUGH EXTENDING FROM LAKE SUPERIOR TO
INDIANA WAS SLIDING QUICKLY TO THE EAST AS A SFC RIDGE OR ARCTIC
HIGH PRES BUILDS FROM SASK AND THE NRN PLAINS INTO THE UPPER MS
VALLEY. VEERING LOW LEVEL WINDS TO WNW AND VERY COLD AIR WITH 850 MB
TEMPS FROM -21C TO -25C SUPPORTED LES BANDS INTO THE KEWEENAW AND
THE NE CWA. KMQT AND MONTREAL RIVER RADARS INDICATED THAT THE
HEAVIEST LES ASOCIATED WITH A TROUGH OR WEAK MESO LOW OVER SE LAKE
SUPERIOR HAD SHIFTED INTO NW LUCE COUNTY. SATELLITE AND WEB CAMS
OVER THE KEWEENAW SUGGEST THAT THE HEAVIER LES FROM MON AFTERNOON
AND EVENING HAD DIMINISHED AS LES TRANSITIONS TOWARD MULTIPLE WEAKER
BANDS. CLEARING OVER INLAND LOCATIONS HAS ALLOWED TEMPS TO DROP TO
AROUND -25F AT WAKEFIELD AND LANDOLAKES WHERE WINDS WERE CALM. WINDS
IN THE TO 10 MPH RANGE MOST LOCATIONS IN THE INTERIOR WEST COMBINED
WITH TEMPS IN THE -8 TO -15 RANGE HAS PUSHED WIND CHILLS INTO THE
-20 TO -30 RANGE.
TODAY...THE HIGH RES MODELS SUGGEST THAT THE STRONGEST LOW LEVEL
CONV SUPPORTED BY THE LAKE INDUCED TROUGHING OVER SE LAKE SUPERIOR
WILL GRADUALLY SHIFT TO THE EAST AS NW WINDS INCREASE ACROSS LAKE
SUPERIOR. WITH ENOUGH OF THE DGZ IN THE CONVECTIVE LAYER...SLR
VALUES SHOULD BE HIGH ENOUGH TO SUPPORT OVERALL SNOWFALL TOTALS IN
THE 4 TO 8 INCH RANGE...WITH SOME ISOLATED GREATER AMOUNTS POSSIBLE
WITH THE GREATEST AMOUNTS FROM GRAND MARAIS TO PINE STUMP JCT AND
CRISP POINT. OVER THE WEST...THE GREATEST LOW LEVEL CONV BETWEEN
HOUGHTON AND TWIN LAKES IS EXPECTED TO WEAKEN WITH NW FLOW ACROSS
THE SHORT AXIS OF THE WRN LAKE. ADDITIONAL AMOUNTS IN THE 1 TO 3
INCH RANGE ARE EXPECTED WITH THE GREATEST AMOUNTS THIS MORNING.
TONIGHT...AS THE ARCTIC RIDGE BUILDS INTO NRN ONTARIO...MODELS
SUGGEST THAT THE LOW LEVEL WINDS WILL CONTINUE TO VEER AND WEAKEN.
AS A RESULT THE LAKE INDUCED TROUGH OVER THE ERN LAKE AND BEST LOW
LEVEL CONV IS EXPECTED TO SHIFT BACK TO THE WEST. HOWEVER...THE
LOCATION OF ANY HEAVIER SNOWBANDS IS LESS CERTAIN. SO...2 TO 5 INCH
AMOUNTS MAY BE POSSIBLE BETWEEN MUUNSING AND NRN LUCE COUNTY. WITH
MORE ACYC FLOW OVER THE WEST AND INVERSION HEIGHTS DROPPING TO
AROUND 4K FT...MAINLY 1 TO 2 INCH AMOUNTS ARE EXPECTED. EVEN THOUGH
TEMPS WILL DROP OFF AGAIN TO -15 TO -20 OVER THE INLAND WEST...LIGHTER
WINDS AT OR BELOW 5 MPH SHOULD REDUCE THE SEVERITY OF WIND
CHILLS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 539 AM EST TUE DEC 31 2013
WILL START OFF WEDNESDAY MORNING WHERE WE ARE ALL TOO FAMILIAR
WITH...UNDER A BROAD 500MB TROUGH. THE CENTER OF THE LOW WILL BE
OVER CENTRAL QUEBEC...WITH A TROUGH EXTENDING SE ACROSS THE N PLAINS
AND INTO THE 4-CORNERS REGION. A DISTURBANCE TRACKING TO OUR S LOOKS
TO BE TOO FAR AWAY TO DO MUCH FOR OUR WX UP N...SO GOT RID OF THE
SLIGHT CHANCE POPS THAT WERE BLANKETING S CENTRAL UPPER MI WEDNESDAY.
THE COLD SNAP WILL LINGER THROUGH THURSDAY...BEFORE SLOWLY
MODERATING FRIDAY AND SATURDAY. WILL WILL CONTINUE TO BE IN A
DIFFICULT POSITION...WHERE TEMPERATURES WILL BE VERY COLD...BUT
WINDS WILL BE BORDERLINE OR WELL BELOW WIND CHILL ADVISORY CRITERIA
/10MPH/.
MUCH OF OUR WX IN THE MID RANGE OF THE FCST PERIOD WILL BE DOMINATED
BY THE WEAKENING BY STILL PERSISTENT SFC LOW/TROUGH WEAKENING ACROSS
E LAKE SUPERIOR AND E UPPER MI. WHILE THE STRONG HIGH OVER MN IS
ABLE TO TO DISRUPT THE LES OVER FAR W UPPER MI WEDNESDAY AND
WEDNESDAY NIGHT...PERSISTENT N TO NW FLOW SHOULD KEEP A HEALTHY BAND
OR MORE LIKELY MULTI-BAND LES GOING E OF MARQUETTE THROUGH
MUNISING...AND E OF MUNISING NEAR LAKE SUPERIOR.
FOR LATE THURSDAY AFTERNOON THROUGH THURSDAY NIGHT...THE EVER
WEAKENING SFC TROUGH OUT E WILL FINALLY LOSE OUT...WITH THE 500MB
TROUGH EXITING E TO THE LOWER GREAT LAKES. LIGHT AND MORE VARIABLE
NEAR-SFC WINDS SHOULD PUSH LIGHT/MODERATE LES BANDS OFF INTO LAKE
SUPERIOR.
CONTINUED AN ATTEMPT TO ADD SOME BETTER TIMING TO THE LONGER TERM
POPS/WX FOR FRIDAY ON. MODELS ARE CONSISTENT ON BRINGING THE 500MB
RIDGE ACROSS THE UPPER GREAT LAKES FRIDAY...WITH THE NEXT LOW OVER
CENTRAL CANADA POISED TO SINK SE AND DOMINATE OUR WX FOR THROUGH AT
LEAST EARLY NEXT WEEK.
BROUGHT THE STRONG SW WINDS MORE TO THE GREAT LAKES SHORELINES
FRIDAY/SATURDAY...AS THE LARGER SCALE MODELS TYPICALLY HAVE A
DIFFICULT TIME WITH THIS. GALES WILL BE POSSIBLE OVER LAKE MI...AND
E LAKE SUPERIOR LATE FRIDAY AFTERNOON THROUGH EARLY SATURDAY
MORNING. BLOWING SNOW WAS ALSO INTRODUCED...MAINLY CENTRAL AND E
NEAR THE GREAT LAKES. 45-55KT WINDS AT 850MB ARE STILL BEING SHOWN
18Z FRIDAY TO AROUND 12Z SATURDAY. MODEL DISCREPANCIES REMAIN IN THE
TIMING OF THE SFC LOW AND ITS ASSOCIATED COLD FRONT...ALTHOUGH MUCH
MORE IN LINE THAN 24HRS AGO. EXPECT THE
A BURST OF HEAVY WET SNOW WILL BE POSSIBLE ACROSS MUCH OF THE CWA IF
THE GFS IS CORRECT. WILL GO CLOSER TO THE 31/00Z ECMWF AT THIS POINT
WITH THE BULK OF THE ENERGY SLIDING ACROSS THE N HALF OF THE
AREA...WITH LES COMING BACK IN BEHIND THE PASSAGE OF THE COLD FRONT
SATURDAY MORNING. WITH THE COLD AIR RAPIDLY SWINGING BACK IN ON W TO
NW WINDS SATURDAY AFTERNOON INTO EARLY SUNDAY...EXPECT A BRIEF
MOMENT OF LAKE ENHANCED SNOW ACROSS THE KEWEENAW PENINSULA.
HIGHLIGHTED THE POTENTIAL IN THE HWO/EHWO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1226 PM EST TUE DEC 31 2013
KIWD...AS WINDS GO TO THE WNW...EXPECT SOME LAKE EFFECT CLOUDS AND
LIGHT SNOW SHOWERS WILL CONTINUE THIS AFTERNOON THROUGH THE PERIOD
WITH MVFR CONDITIONS EXPECTED.
KCMX...WITH STRONG GUSTY WINDS THIS AFTERNOON...BLOWING SNOW WILL
CONTINUE TO CAUSE VLIFR CONDITIONS. AS THE WINDS DIE DOWN BY THIS
EVENING...CONDITIONS WILL IMPROVE FROM IFR TO MVFR.
SAW...VFR CONDITIONS WILL CONTINUE THROUGH TONIGHT WITH DOWNSLOPE
WINDS. AS WINDS GO NORTHERLY WED MORNING...LAKE EFFECT SNOW SHOWERS
WILL MOVE BACK IN WITH MVFR CONDITIONS EXPECTED.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 AM EST TUE DEC 31 2013
HEAVY FREEZING SPRAY WILL REMAIN A CONCERN FOR MAINLY CENTRAL AND
EASTERN LAKE SUPERIOR THROUGH EARLY WEDESDAY...AS AIR TEMPS CONTINUE TO
BE IN THE TEENS ABOVE ZERO TO THE SINGLE DIGITS BELOW ZERO...AND NW
TO N WINDS IN THE 20-30KT RANGE.
STRONG HIGH PRESSURE OVER SASKATCHEWAN WILL BUILD INTO MINNESOTA
TONIGHT...AND REMAIN NEARLY STATIONARY THROUGH THURSDAY.
OTHERWISE...THE PESKY LOW/TROUGH STRETCHING FROM EASTERN LAKE
SUPERIOR TO ALL OF SOUTHEASTERN ONTARIO WILL EXIT EASTWARD
TODAY...LEAVING A WEAKENING TROUGH ACROSS LAKE SUPERIOR THAT WILL
LINGER THROUGH THURSDAY...AS THE HIGH PRESSURE SYSTEM TO OUR WEST
SINKS INTO THE MID MISSISSIPPI VALLEY. EXPECT LOW PRESSURE ALONG THE
CENTRAL U.S./CANADIAN BORDER FRIDAY TO CROSS LAKE SUPERIOR AND
ONTARIO ON SATURDAY. AHEAD OF THIS LOW...S GUSTS OF 25-30KTS LATE
FRIDAY AFTERNOON INTO SATURDAY MORNING MAY JUMP UP TO GALES
/PARTICULARLY ACROSS E LAKE SUPERIOR FRIDAY NIGHT/.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ001-
003-006-007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING UNTIL 9 AM EST WEDNESDAY FOR LSZ243-
244-264-266.
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST WEDNESDAY FOR LSZ248-
265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
WEDNESDAY FOR LSZ241-242-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ249-
250.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...07
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
707 AM EST TUE DEC 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EST TUE DEC 31 2013
WV IMAGERY AND RUC ANALYSIS INDICATED CYCLONIC WNW MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES AROUND THE POLAR VORTEX LOCATED OVER
SRN HUDSON BAY. A SHORTWAVE TROUGH EXTENDING FROM LAKE SUPERIOR TO
INDIANA WAS SLIDING QUICKLY TO THE EAST AS A SFC RIDGE OR ARCTIC
HIGH PRES BUILDS FROM SASK AND THE NRN PLAINS INTO THE UPPER MS
VALLEY. VEERING LOW LEVEL WINDS TO WNW AND VERY COLD AIR WITH 850 MB
TEMPS FROM -21C TO -25C SUPPORTED LES BANDS INTO THE KEWEENAW AND
THE NE CWA. KMQT AND MONTREAL RIVER RADARS INDICATED THAT THE
HEAVIEST LES ASOCIATED WITH A TROUGH OR WEAK MESO LOW OVER SE LAKE
SUPERIOR HAD SHIFTED INTO NW LUCE COUNTY. SATELLITE AND WEB CAMS
OVER THE KEWEENAW SUGGEST THAT THE HEAVIER LES FROM MON AFTERNOON
AND EVENING HAD DIMINISHED AS LES TRANSITIONS TOWARD MULTIPLE WEAKER
BANDS. CLEARING OVER INLAND LOCATIONS HAS ALLOWED TEMPS TO DROP TO
AROUND -25F AT WAKEFIELD AND LANDOLAKES WHERE WINDS WERE CALM. WINDS
IN THE TO 10 MPH RANGE MOST LOCATIONS IN THE INTERIOR WEST COMBINED
WITH TEMPS IN THE -8 TO -15 RANGE HAS PUSHED WIND CHILLS INTO THE
-20 TO -30 RANGE.
TODAY...THE HIGH RES MODELS SUGGEST THAT THE STRONGEST LOW LEVEL
CONV SUPPORTED BY THE LAKE INDUCED TROUGHING OVER SE LAKE SUPERIOR
WILL GRADUALLY SHIFT TO THE EAST AS NW WINDS INCREASE ACROSS LAKE
SUPERIOR. WITH ENOUGH OF THE DGZ IN THE CONVECTIVE LAYER...SLR
VALUES SHOULD BE HIGH ENOUGH TO SUPPORT OVERALL SNOWFALL TOTALS IN
THE 4 TO 8 INCH RANGE...WITH SOME ISOLATED GREATER AMOUNTS POSSIBLE
WITH THE GREATEST AMOUNTS FROM GRAND MARAIS TO PINE STUMP JCT AND
CRISP POINT. OVER THE WEST...THE GREATEST LOW LEVEL CONV BETWEEN
HOUGHTON AND TWIN LAKES IS EXPECTED TO WEAKEN WITH NW FLOW ACROSS
THE SHORT AXIS OF THE WRN LAKE. ADDITIONAL AMOUNTS IN THE 1 TO 3
INCH RANGE ARE EXPECTED WITH THE GREATEST AMOUNTS THIS MORNING.
TONIGHT...AS THE ARCTIC RIDGE BUILDS INTO NRN ONTARIO...MODELS
SUGGEST THAT THE LOW LEVEL WINDS WILL CONTINUE TO VEER AND WEAKEN.
AS A RESULT THE LAKE INDUCED TROUGH OVER THE ERN LAKE AND BEST LOW
LEVEL CONV IS EXPECTED TO SHIFT BACK TO THE WEST. HOWEVER...THE
LOCATION OF ANY HEAVIER SNOWBANDS IS LESS CERTAIN. SO...2 TO 5 INCH
AMOUNTS MAY BE POSSIBLE BETWEEN MUUNSING AND NRN LUCE COUNTY. WITH
MORE ACYC FLOW OVER THE WEST AND INVERSION HEIGHTS DROPPING TO
AROUND 4K FT...MAINLY 1 TO 2 INCH AMOUNTS ARE EXPECTED. EVEN THOUGH
TEMPS WILL DROP OFF AGAIN TO -15 TO -20 OVER THE INLAND WEST...LIGHTER
WINDS AT OR BELOW 5 MPH SHOULD REDUCE THE SEVERITY OF WIND
CHILLS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 539 AM EST TUE DEC 31 2013
WILL START OFF WEDNESDAY MORNING WHERE WE ARE ALL TOO FAMILIAR
WITH...UNDER A BROAD 500MB TROUGH. THE CENTER OF THE LOW WILL BE
OVER CENTRAL QUEBEC...WITH A TROUGH EXTENDING SE ACROSS THE N PLAINS
AND INTO THE 4-CORNERS REGION. A DISTURBANCE TRACKING TO OUR S LOOKS
TO BE TOO FAR AWAY TO DO MUCH FOR OUR WX UP N...SO GOT RID OF THE
SLIGHT CHANCE POPS THAT WERE BLANKETING S CENTRAL UPPER MI WEDNESDAY.
THE COLD SNAP WILL LINGER THROUGH THURSDAY...BEFORE SLOWLY
MODERATING FRIDAY AND SATURDAY. WILL WILL CONTINUE TO BE IN A
DIFFICULT POSITION...WHERE TEMPERATURES WILL BE VERY COLD...BUT
WINDS WILL BE BORDERLINE OR WELL BELOW WIND CHILL ADVISORY CRITERIA
/10MPH/.
MUCH OF OUR WX IN THE MID RANGE OF THE FCST PERIOD WILL BE DOMINATED
BY THE WEAKENING BY STILL PERSISTENT SFC LOW/TROUGH WEAKENING ACROSS
E LAKE SUPERIOR AND E UPPER MI. WHILE THE STRONG HIGH OVER MN IS
ABLE TO TO DISRUPT THE LES OVER FAR W UPPER MI WEDNESDAY AND
WEDNESDAY NIGHT...PERSISTENT N TO NW FLOW SHOULD KEEP A HEALTHY BAND
OR MORE LIKELY MULTI-BAND LES GOING E OF MARQUETTE THROUGH
MUNISING...AND E OF MUNISING NEAR LAKE SUPERIOR.
FOR LATE THURSDAY AFTERNOON THROUGH THURSDAY NIGHT...THE EVER
WEAKENING SFC TROUGH OUT E WILL FINALLY LOSE OUT...WITH THE 500MB
TROUGH EXITING E TO THE LOWER GREAT LAKES. LIGHT AND MORE VARIABLE
NEAR-SFC WINDS SHOULD PUSH LIGHT/MODERATE LES BANDS OFF INTO LAKE
SUPERIOR.
CONTINUED AN ATTEMPT TO ADD SOME BETTER TIMING TO THE LONGER TERM
POPS/WX FOR FRIDAY ON. MODELS ARE CONSISTENT ON BRINGING THE 500MB
RIDGE ACROSS THE UPPER GREAT LAKES FRIDAY...WITH THE NEXT LOW OVER
CENTRAL CANADA POISED TO SINK SE AND DOMINATE OUR WX FOR THROUGH AT
LEAST EARLY NEXT WEEK.
BROUGHT THE STRONG SW WINDS MORE TO THE GREAT LAKES SHORELINES
FRIDAY/SATURDAY...AS THE LARGER SCALE MODELS TYPICALLY HAVE A
DIFFICULT TIME WITH THIS. GALES WILL BE POSSIBLE OVER LAKE MI...AND
E LAKE SUPERIOR LATE FRIDAY AFTERNOON THROUGH EARLY SATURDAY
MORNING. BLOWING SNOW WAS ALSO INTRODUCED...MAINLY CENTRAL AND E
NEAR THE GREAT LAKES. 45-55KT WINDS AT 850MB ARE STILL BEING SHOWN
18Z FRIDAY TO AROUND 12Z SATURDAY. MODEL DISCREPANCIES REMAIN IN THE
TIMING OF THE SFC LOW AND ITS ASSOCIATED COLD FRONT...ALTHOUGH MUCH
MORE IN LINE THAN 24HRS AGO. EXPECT THE
A BURST OF HEAVY WET SNOW WILL BE POSSIBLE ACROSS MUCH OF THE CWA IF
THE GFS IS CORRECT. WILL GO CLOSER TO THE 31/00Z ECMWF AT THIS POINT
WITH THE BULK OF THE ENERGY SLIDING ACROSS THE N HALF OF THE
AREA...WITH LES COMING BACK IN BEHIND THE PASSAGE OF THE COLD FRONT
SATURDAY MORNING. WITH THE COLD AIR RAPIDLY SWINGING BACK IN ON W TO
NW WINDS SATURDAY AFTERNOON INTO EARLY SUNDAY...EXPECT A BRIEF
MOMENT OF LAKE ENHANCED SNOW ACROSS THE KEWEENAW PENINSULA.
HIGHLIGHTED THE POTENTIAL IN THE HWO/EHWO.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 654 AM EST TUE DEC 31 2013
KIWD...AS WINDS VEER FROMM SW TO WNW IN THE WAKE OF A DISTURBANCE
PASSING TO THE SOUTH OF UPPER MI...EXPECT SOME LAKE EFFECT CLOUDS
AND LIGHT SNOW SHOWERS TO MOVE BACK IN THIS MORNING. CONDITIONS
SHOULD GRADUALLY DROP FROM VFR TO MVFR. IFR VSBYS ARE POSSIBLE LATER
IN THE DAY IF THE FLOW VEERS FAR ENOUGH TO THE NW.
KCMX...VEERING W TO NW FLOW OF ARCTIC AIR WILL KEEP LES GOING
DURING THE FORECAST PERIOD. ALTHOUGH THERE COULD BE SOME IMPROVEMENT
IN VSBY BETWEEN THE LES BANDS...IFR CONDITIONS SHOULD PREDOMINATE.
SAW...WITH A DOWNSLOPE WSW FLOW OF DRY ARCTIC AIR VEERING TO WNW...
EXPECT VFR CONDITIONS TO PREDOMINATE THIS FCST PERIOD EVEN THOUGH
OCNL FLURRIES/MVFR CIGS WL BE POSSIBLE THIS AFTN/EVNG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 AM EST TUE DEC 31 2013
HEAVY FREEZING SPRAY WILL REMAIN A CONCERN FOR MAINLY CENTRAL AND
EASTERN LAKE SUPERIOR THROUGH EARLY WEDESDAY...AS AIR TEMPS CONTINUE TO
BE IN THE TEENS ABOVE ZERO TO THE SINGLE DIGITS BELOW ZERO...AND NW
TO N WINDS IN THE 20-30KT RANGE.
STRONG HIGH PRESSURE OVER SASKATCHEWAN WILL BUILD INTO MINNESOTA
TONIGHT...AND REMAIN NEARLY STATIONARY THROUGH THURSDAY.
OTHERWISE...THE PESKY LOW/TROUGH STRETCHING FROM EASTERN LAKE
SUPERIOR TO ALL OF SOUTHEASTERN ONTARIO WILL EXIT EASTWARD
TODAY...LEAVING A WEAKENING TROUGH ACROSS LAKE SUPERIOR THAT WILL
LINGER THROUGH THURSDAY...AS THE HIGH PRESSURE SYSTEM TO OUR WEST
SINKS INTO THE MID MISSISSIPPI VALLEY. EXPECT LOW PRESSURE ALONG THE
CENTRAL U.S./CANADIAN BORDER FRIDAY TO CROSS LAKE SUPERIOR AND
ONTARIO ON SATURDAY. AHEAD OF THIS LOW...S GUSTS OF 25-30KTS LATE
FRIDAY AFTERNOON INTO SATURDAY MORNING MAY JUMP UP TO GALES
/PARTICULARLY ACROSS E LAKE SUPERIOR FRIDAY NIGHT/.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ002-004-005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006-
007-085.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING UNTIL 9 AM EST WEDNESDAY FOR LSZ243-
244-264-266.
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST WEDNESDAY FOR LSZ248-
265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
WEDNESDAY FOR LSZ241-242-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ249-
250.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...JLB
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
541 AM EST TUE DEC 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EST TUE DEC 31 2013
WV IMAGERY AND RUC ANALYSIS INDICATED CYCLONIC WNW MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES AROUND THE POLAR VORTEX LOCATED OVER
SRN HUDSON BAY. A SHORTWAVE TROUGH EXTENDING FROM LAKE SUPERIOR TO
INDIANA WAS SLIDING QUICKLY TO THE EAST AS A SFC RIDGE OR ARCTIC
HIGH PRES BUILDS FROM SASK AND THE NRN PLAINS INTO THE UPPER MS
VALLEY. VEERING LOW LEVEL WINDS TO WNW AND VERY COLD AIR WITH 850 MB
TEMPS FROM -21C TO -25C SUPPORTED LES BANDS INTO THE KEWEENAW AND
THE NE CWA. KMQT AND MONTREAL RIVER RADARS INDICATED THAT THE
HEAVIEST LES ASOCIATED WITH A TROUGH OR WEAK MESO LOW OVER SE LAKE
SUPERIOR HAD SHIFTED INTO NW LUCE COUNTY. SATELLITE AND WEB CAMS
OVER THE KEWEENAW SUGGEST THAT THE HEAVIER LES FROM MON AFTERNOON
AND EVENING HAD DIMINISHED AS LES TRANSITIONS TOWARD MULTIPLE WEAKER
BANDS. CLEARING OVER INLAND LOCATIONS HAS ALLOWED TEMPS TO DROP TO
AROUND -25F AT WAKEFIELD AND LANDOLAKES WHERE WINDS WERE CALM. WINDS
IN THE TO 10 MPH RANGE MOST LOCATIONS IN THE INTERIOR WEST COMBINED
WITH TEMPS IN THE -8 TO -15 RANGE HAS PUSHED WIND CHILLS INTO THE
-20 TO -30 RANGE.
TODAY...THE HIGH RES MODELS SUGGEST THAT THE STRONGEST LOW LEVEL
CONV SUPPORTED BY THE LAKE INDUCED TROUGHING OVER SE LAKE SUPERIOR
WILL GRADUALLY SHIFT TO THE EAST AS NW WINDS INCREASE ACROSS LAKE
SUPERIOR. WITH ENOUGH OF THE DGZ IN THE CONVECTIVE LAYER...SLR
VALUES SHOULD BE HIGH ENOUGH TO SUPPORT OVERALL SNOWFALL TOTALS IN
THE 4 TO 8 INCH RANGE...WITH SOME ISOLATED GREATER AMOUNTS POSSIBLE
WITH THE GREATEST AMOUNTS FROM GRAND MARAIS TO PINE STUMP JCT AND
CRISP POINT. OVER THE WEST...THE GREATEST LOW LEVEL CONV BETWEEN
HOUGHTON AND TWIN LAKES IS EXPECTED TO WEAKEN WITH NW FLOW ACROSS
THE SHORT AXIS OF THE WRN LAKE. ADDITIONAL AMOUNTS IN THE 1 TO 3
INCH RANGE ARE EXPECTED WITH THE GREATEST AMOUNTS THIS MORNING.
TONIGHT...AS THE ARCTIC RIDGE BUILDS INTO NRN ONTARIO...MODELS
SUGGEST THAT THE LOW LEVEL WINDS WILL CONTINUE TO VEER AND WEAKEN.
AS A RESULT THE LAKE INDUCED TROUGH OVER THE ERN LAKE AND BEST LOW
LEVEL CONV IS EXPECTED TO SHIFT BACK TO THE WEST. HOWEVER...THE
LOCATION OF ANY HEAVIER SNOWBANDS IS LESS CERTAIN. SO...2 TO 5 INCH
AMOUNTS MAY BE POSSIBLE BETWEEN MUUNSING AND NRN LUCE COUNTY. WITH
MORE ACYC FLOW OVER THE WEST AND INVERSION HEIGHTS DROPPING TO
AROUND 4K FT...MAINLY 1 TO 2 INCH AMOUNTS ARE EXPECTED. EVEN THOUGH
TEMPS WILL DROP OFF AGAIN TO -15 TO -20 OVER THE INLAND WEST...LIGHTER
WINDS AT OR BELOW 5 MPH SHOULD REDUCE THE SEVERITY OF WIND
CHILLS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 539 AM EST TUE DEC 31 2013
WILL START OFF WEDNESDAY MORNING WHERE WE ARE ALL TOO FAMILIAR
WITH...UNDER A BROAD 500MB TROUGH. THE CENTER OF THE LOW WILL BE
OVER CENTRAL QUEBEC...WITH A TROUGH EXTENDING SE ACROSS THE N PLAINS
AND INTO THE 4-CORNERS REGION. A DISTURBANCE TRACKING TO OUR S LOOKS
TO BE TOO FAR AWAY TO DO MUCH FOR OUR WX UP N...SO GOT RID OF THE
SLIGHT CHANCE POPS THAT WERE BLANKETING S CENTRAL UPPER MI WEDNESDAY.
THE COLD SNAP WILL LINGER THROUGH THURSDAY...BEFORE SLOWLY
MODERATING FRIDAY AND SATURDAY. WILL WILL CONTINUE TO BE IN A
DIFFICULT POSITION...WHERE TEMPERATURES WILL BE VERY COLD...BUT
WINDS WILL BE BORDERLINE OR WELL BELOW WIND CHILL ADVISORY CRITERIA
/10MPH/.
MUCH OF OUR WX IN THE MID RANGE OF THE FCST PERIOD WILL BE DOMINATED
BY THE WEAKENING BY STILL PERSISTENT SFC LOW/TROUGH WEAKENING ACROSS
E LAKE SUPERIOR AND E UPPER MI. WHILE THE STRONG HIGH OVER MN IS
ABLE TO TO DISRUPT THE LES OVER FAR W UPPER MI WEDNESDAY AND
WEDNESDAY NIGHT...PERSISTENT N TO NW FLOW SHOULD KEEP A HEALTHY BAND
OR MORE LIKELY MULTI-BAND LES GOING E OF MARQUETTE THROUGH
MUNISING...AND E OF MUNISING NEAR LAKE SUPERIOR.
FOR LATE THURSDAY AFTERNOON THROUGH THURSDAY NIGHT...THE EVER
WEAKENING SFC TROUGH OUT E WILL FINALLY LOSE OUT...WITH THE 500MB
TROUGH EXITING E TO THE LOWER GREAT LAKES. LIGHT AND MORE VARIABLE
NEAR-SFC WINDS SHOULD PUSH LIGHT/MODERATE LES BANDS OFF INTO LAKE
SUPERIOR.
CONTINUED AN ATTEMPT TO ADD SOME BETTER TIMING TO THE LONGER TERM
POPS/WX FOR FRIDAY ON. MODELS ARE CONSISTENT ON BRINGING THE 500MB
RIDGE ACROSS THE UPPER GREAT LAKES FRIDAY...WITH THE NEXT LOW OVER
CENTRAL CANADA POISED TO SINK SE AND DOMINATE OUR WX FOR THROUGH AT
LEAST EARLY NEXT WEEK.
BROUGHT THE STRONG SW WINDS MORE TO THE GREAT LAKES SHORELINES
FRIDAY/SATURDAY...AS THE LARGER SCALE MODELS TYPICALLY HAVE A
DIFFICULT TIME WITH THIS. GALES WILL BE POSSIBLE OVER LAKE MI...AND
E LAKE SUPERIOR LATE FRIDAY AFTERNOON THROUGH EARLY SATURDAY
MORNING. BLOWING SNOW WAS ALSO INTRODUCED...MAINLY CENTRAL AND E
NEAR THE GREAT LAKES. 45-55KT WINDS AT 850MB ARE STILL BEING SHOWN
18Z FRIDAY TO AROUND 12Z SATURDAY. MODEL DISCREPANCIES REMAIN IN THE
TIMING OF THE SFC LOW AND ITS ASSOCIATED COLD FRONT...ALTHOUGH MUCH
MORE IN LINE THAN 24HRS AGO. EXPECT THE
A BURST OF HEAVY WET SNOW WILL BE POSSIBLE ACROSS MUCH OF THE CWA IF
THE GFS IS CORRECT. WILL GO CLOSER TO THE 31/00Z ECMWF AT THIS POINT
WITH THE BULK OF THE ENERGY SLIDING ACROSS THE N HALF OF THE
AREA...WITH LES COMING BACK IN BEHIND THE PASSAGE OF THE COLD FRONT
SATURDAY MORNING. WITH THE COLD AIR RAPIDLY SWINGING BACK IN ON W TO
NW WINDS SATURDAY AFTERNOON INTO EARLY SUNDAY...EXPECT A BRIEF
MOMENT OF LAKE ENHANCED SNOW ACROSS THE KEWEENAW PENINSULA.
HIGHLIGHTED THE POTENTIAL IN THE HWO/EHWO.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1223 AM EST TUE DEC 31 2013
KIWD...AS WINDS VEER FM SW TO WNW IN THE WAKE OF A DISTURBANCE
PASSING TO THE S OF UPR MI...EXPECT SOME LK EFFECT CLDS/-SHSN TO
SPREAD BACK OVER THIS SITE BY SUNRISE. CONDITIONS SHOULD GRDLY
DETERIORATE FM VFR TO MVFR. IFR VSBYS ARE PSBL LATER IN THE DAY IF
THE FLOW VEERS FAR ENUF TO THE NW.
KCMX...VEERING W TO NW FLOW OF ARCTIC AIR WL ALLOW LK EFFECT -SHSN
TO IMPACT THIS LOCATION THIS FCST PERIOD. ALTHOUGH THERE COULD BE
SOME IMPROVEMENT IN VSBYS BTWN THE BANDS...IFR CONDITIONS SHOULD
PREDOMINATE.
SAW...WITH A DOWNSLOPE WSW FLOW OF DRY ARCTIC AIR VEERING TO WNW...
EXPECT VFR CONDITIONS TO PREDOMINATE THIS FCST PERIOD EVEN THOUGH
OCNL FLURRIES/MVFR CIGS WL BE POSSIBLE THIS AFTN/EVNG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 AM EST TUE DEC 31 2013
HEAVY FREEZING SPRAY WILL REMAIN A CONCERN FOR MAINLY CENTRAL AND
EASTERN LAKE SUPERIOR THROUGH EARLY WEDESDAY...AS AIR TEMPS CONTINUE TO
BE IN THE TEENS ABOVE ZERO TO THE SINGLE DIGITS BELOW ZERO...AND NW
TO N WINDS IN THE 20-30KT RANGE.
STRONG HIGH PRESSURE OVER SASKATCHEWAN WILL BUILD INTO MINNESOTA
TONIGHT...AND REMAIN NEARLY STATIONARY THROUGH THURSDAY.
OTHERWISE...THE PESKY LOW/TROUGH STRETCHING FROM EASTERN LAKE
SUPERIOR TO ALL OF SOUTHEASTERN ONTARIO WILL EXIT EASTWARD
TODAY...LEAVING A WEAKENING TROUGH ACROSS LAKE SUPERIOR THAT WILL
LINGER THROUGH THURSDAY...AS THE HIGH PRESSURE SYSTEM TO OUR WEST
SINKS INTO THE MID MISSISSIPPI VALLEY. EXPECT LOW PRESSURE ALONG THE
CENTRAL U.S./CANADIAN BORDER FRIDAY TO CROSS LAKE SUPERIOR AND
ONTARIO ON SATURDAY. AHEAD OF THIS LOW...S GUSTS OF 25-30KTS LATE
FRIDAY AFTERNOON INTO SATURDAY MORNING MAY JUMP UP TO GALES
/PARTICULARLY ACROSS E LAKE SUPERIOR FRIDAY NIGHT/.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ002-004-005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006-
007-085.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING UNTIL 9 AM EST WEDNESDAY FOR LSZ243-
244-264-266.
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST WEDNESDAY FOR LSZ248-
265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
WEDNESDAY FOR LSZ241-242-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ249-
250.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...KF
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
519 AM EST TUE DEC 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 518 AM EST TUE DEC 31 2013
WV IMAGERY AND RUC ANALYSIS INDICATED CYCLONIC WNW MID/UPPER LEVEL
FLOW INTO THE NRN GREAT LAKES AROUND THE POLAR VORTEX LOCATED OVER
SRN HUDSON BAY. A SHORTWAVE TROUGH EXTENDING FROM LAKE SUPERIOR TO
INDIANA WAS SLIDING QUICKLY TO THE EAST AS A SFC RIDGE OR ARCTIC
HIGH PRES BUILDS FROM SASK AND THE NRN PLAINS INTO THE UPPER MS
VALLEY. VEERING LOW LEVEL WINDS TO WNW AND VERY COLD AIR WITH 850 MB
TEMPS FROM -21C TO -25C SUPPORTED LES BANDS INTO THE KEWEENAW AND
THE NE CWA. KMQT AND MONTREAL RIVER RADARS INDICATED THAT THE
HEAVIEST LES ASOCIATED WITH A TROUGH OR WEAK MESO LOW OVER SE LAKE
SUPERIOR HAD SHIFTED INTO NW LUCE COUNTY. SATELLITE AND WEB CAMS
OVER THE KEWEENAW SUGGEST THAT THE HEAVIER LES FROM MON AFTERNOON
AND EVENING HAD DIMINISHED AS LES TRANSITIONS TOWARD MULTIPLE WEAKER
BANDS. CLEARING OVER INLAND LOCATIONS HAS ALLOWED TEMPS TO DROP TO
AROUND -25F AT WAKEFIELD AND LANDOLAKES WHERE WINDS WERE CALM. WINDS
IN THE TO 10 MPH RANGE MOST LOCATIONS IN THE INTERIOR WEST COMBINED
WITH TEMPS IN THE -8 TO -15 RANGE HAS PUSHED WIND CHILLS INTO THE
-20 TO -30 RANGE.
TODAY...THE HIGH RES MODELS SUGGEST THAT THE STRONGEST LOW LEVEL
CONV SUPPORTED BY THE LAKE INDUCED TROUGHING OVER SE LAKE SUPERIOR
WILL GRADUALLY SHIFT TO THE EAST AS NW WINDS INCREASE ACROSS LAKE
SUPERIOR. WITH ENOUGH OF THE DGZ IN THE CONVECTIVE LAYER...SLR
VALUES SHOULD BE HIGH ENOUGH TO SUPPORT OVERALL SNOWFALL TOTALS IN
THE 4 TO 8 INCH RANGE...WITH SOME ISOLATED GREATER AMOUNTS POSSIBLE
WITH THE GREATEST AMOUNTS FROM GRAND MARAIS TO PINE STUMP JCT AND
CRISP POINT. OVER THE WEST...THE GREATEST LOW LEVEL CONV BETWEEN
HOUGHTON AND TWIN LAKES IS EXPECTED TO WEAKEN WITH NW FLOW ACROSS
THE SHORT AXIS OF THE WRN LAKE. ADDITIONAL AMOUNTS IN THE 1 TO 3
INCH RANGE ARE EXPECTED WITH THE GREATEST AMOUNTS THIS MORNING.
TONIGHT...AS THE ARCTIC RIDGE BUILDS INTO NRN ONTARIO...MODELS
SUGGEST THAT THE LOW LEVEL WINDS WILL CONTINUE TO VEER AND WEAKEN.
AS A RESULT THE LAKE INDUCED TROUGH OVER THE ERN LAKE AND BEST LOW
LEVEL CONV IS EXPECTED TO SHIFT BACK TO THE WEST. HOWEVER...THE
LOCATION OF ANY HEAVIER SNOWBANDS IS LESS CERTAIN. SO...2 TO 5 INCH
AMOUNTS MAY BE POSSIBLE BETWEEN MUUNSING AND NRN LUCE COUNTY. WITH
MORE ACYC FLOW OVER THE WEST AND INVERSION HEIGHTS DROPPING TO
AROUND 4K FT...MAINLY 1 TO 2 INCH AMOUNTS ARE EXPECTED. EVEN THOUGH
TEMPS WILL DROP OFF AGAIN TO -15 TO -20 OVER THE INLAND WEST...LIGHTER
WINDS AT OR BELOW 5 MPH SHOULD REDUCE THE SEVERITY OF WIND
CHILLS.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 430 PM EST MON DEC 30 2013
MODELS ARE CONSISTENT IN SHOWING THE 500MB CLOSED LOW OVER QUEBEC
WEDNESDAY MOVING OFF INTO THE ATLANTIC THURSDAY. THE GFS /AS USUAL/
IS MORE PROGRESSIVE THAN THE ECWMF WITH THE LONGWAVE TROUGH IN THE
WAKE OF THE LOW...BRINGING THE TROUGH THROUGH THE GREAT LAKES ON
THURSDAY AFTERNOON. THE ECMWF IS SLOWER AND DEEPER WITH THIS
TROUGH...WITH IT BEING MAINLY OVER WI ON THURSDAY AFTERNOON.
GUIDANCE SUGGESTS THAT THE ECMWF HAS BEEN ERRING ON THE DEEPER AND
MORE AMPLIFIED SIDE LATELY...HOWEVER...AND THIS MAY BE THE CASE.
OVERALL WENT MIDDLE OF THE ROAD FOR THE FORECAST AT THIS
POINT...LEANING MORE TOWARDS THE ECMWF. AS FAR AS WHAT THIS MEANS
FOR THE SURFACE...LOW PRESSURE DEVELOPS IN THE CENTRAL PLAINS AND
RIDES NORTHEASTWARD ALONG THE TROUGH...WHICH BRINGS AN INVERTED
SURFACE TROUGH INTO UPPER MI FOR WEDNESDAY NIGHT-THURSDAY AFTERNOON.
TUESDAY NIGHT WINDS REMAIN OUT OF THE WEST NORTHWEST THROUGH
MIDNIGHT...BEFORE GRADUALLY VEERING TO THE NORTH AND EVEN NORTHEAST
AS THE INVERTED TROUGH SHIFTS WESTWARD. THIS MOVES THE HIGHEST POPS
FROM THE FAR NORTHEASTERN PORTIONS OF THE COUNTY TOWARDS MUNISING
THROUGH THE NIGHT. BY WEDNESDAY AFTERNOON...CONVERGENCE FOCUSES
BETWEEN MARQUETTE AND MUNISING...WHICH IS WHERE HIGHEST POPS ARE
SITUATED IN THE GRIDS. WHILE THIS REMAINS THE CASE THROUGH THURSDAY
AFTERNOON...TOTAL ACCUMULATIONS ARE GENERALLY EXPECTED TO BE ON THE
ORDER OF 2 TO 4 INCHES BETWEEN SHOT POINT AND MUNISING. GIVEN THAT
MOST OF THE BANDS ARE SHIFTING FROM WEST-NORTHWEST INTO A MORE
NORTH-NORTHEAST PATTERN THROUGH THE PERIOD...NOT REALLY EXPECTING
ANY ONE LOCATION TO RECEIVE TOO MUCH ACCUMULATION. ALSO...BEYOND
WEDNESDAY MORNING...WINDS AT 850-925MB BECOME SOMEWHAT MISALIGNED
WITH THE SURFACE WINDS...WHICH IS TYPICALLY LESS SUITABLE FOR MORE
STRUCTURED BANDS. THOUGH INVERSION HEIGHTS ARE HIGHER WITH COLDER
850MB TEMPS...GENERALLY UP TO 6-8KFT...THE DGZ IS LOW AND SO EXPECT
THE SAME SMALL SIZED FLAKES-AND LOW ACCUMULATIONS LIKE THOSE
OBSERVED ACROSS UPPER MI ALL WEEK/DESPITE SIMILAR INVERSION HEIGHTS.
THE NAM HINTS AT SOME HIGHER SNOW RATIOS OCCURRING IN THE
EAST...HOWEVER...THE NAM HAS BEEN TRENDING HIGHER THROUGH THIS PAST
WEEK THAN WHAT IS BEING OBSERVED. OVERALL...WEVE SEEN AROUND 18-20:1
RATIOS...AND THIS IS WHAT WAS USED FOR THE FORECAST. USING THE
NAM...THE BEST LIFT COLLOCATED WITH THE DGZ IS BETWEEN 6Z AND 15Z
WEDNESDAY AROUND MUNISING...AND SOME BIGGER FLAKES MAY BE SEEN
DURING THIS TIME. OTHERWISE...EXPECT ACCUMULATIONS TO RANGE FROM 1-3
INCHES NEAR THE LAKE FROM 6Z WEDNESDAY TO 12Z THURSDAY.
FRIDAY INTO SATURDAY LOW PRESSURE SLIDING OVER THE CANADIAN PRAIRIE
WILL SWING WINDS AROUND TO THE SOUTH ACROSS UPPER MI...PUSHING ALL
LAKE EFFECT SNOW BANDS OFF INTO LAKE SUPERIOR. 850MB TEMPS WARM AS
WELL...WITH THE ECMWF HINTING AT -8C TO -10C FOR BOTH DAYS. THE COLD
FRONT PASSES ON SATURDAY NIGHT. THE ARCTIC PUSH BEHIND THIS TROUGH
IS NOT TOO BAD...AS TEMPS 850MB TEMPS ARE SOMEWHAT RESCUED BY A
BRIEF RIDGE MOVING FROM THE NORTHERN PLAINS INTO THE GREAT LAKES
THROUGH SUNDAY AFTERNOON. KEPT BROAD CHANCE POPS ACROSS THE CWA FOR
MUCH OF THE FORECAST AREA THROUGH SATURDAY NIGHT. ON SUNDAY...TEMPS
ARE COLD ENOUGH AND WINDS OUT OF THE WEST-NORTHWEST...SO KEPT CHANCE
POPS CONFINED TO LAKE SUPERIOR.
THE MAIN DIFFERENCES BETWEEN MODELS LIE ON MONDAY...WITH THE ECMWF
AND THE GFS BOTH HINTING AT A VERY COLD ARCTIC PUSH OF AIR SLIDING
THROUGH...WITH 850MB TEMPS AS LOW AS -35C OVER UPPER MI. THOUGH THE
GFS IS NOT QUITE AS LOW...IT HAS 850MB TEMPS AT -25C TO -30C FOR THE
AREA. WILL TREND LOWER WITH TEMPS DURING THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1223 AM EST TUE DEC 31 2013
KIWD...AS WINDS VEER FM SW TO WNW IN THE WAKE OF A DISTURBANCE
PASSING TO THE S OF UPR MI...EXPECT SOME LK EFFECT CLDS/-SHSN TO
SPREAD BACK OVER THIS SITE BY SUNRISE. CONDITIONS SHOULD GRDLY
DETERIORATE FM VFR TO MVFR. IFR VSBYS ARE PSBL LATER IN THE DAY IF
THE FLOW VEERS FAR ENUF TO THE NW.
KCMX...VEERING W TO NW FLOW OF ARCTIC AIR WL ALLOW LK EFFECT -SHSN
TO IMPACT THIS LOCATION THIS FCST PERIOD. ALTHOUGH THERE COULD BE
SOME IMPROVEMENT IN VSBYS BTWN THE BANDS...IFR CONDITIONS SHOULD
PREDOMINATE.
SAW...WITH A DOWNSLOPE WSW FLOW OF DRY ARCTIC AIR VEERING TO WNW...
EXPECT VFR CONDITIONS TO PREDOMINATE THIS FCST PERIOD EVEN THOUGH
OCNL FLURRIES/MVFR CIGS WL BE POSSIBLE THIS AFTN/EVNG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 AM EST TUE DEC 31 2013
HEAVY FREEZING SPRAY WILL REMAIN A CONCERN FOR MAINLY CENTRAL AND
EASTERN LAKE SUPERIOR THROUGH EARLY WEDESDAY...AS AIR TEMPS CONTINUE TO
BE IN THE TEENS ABOVE ZERO TO THE SINGLE DIGITS BELOW ZERO...AND NW
TO N WINDS IN THE 20-30KT RANGE.
STRONG HIGH PRESSURE OVER SASKATCHEWAN WILL BUILD INTO MINNESOTA
TONIGHT...AND REMAIN NEARLY STATIONARY THROUGH THURSDAY.
OTHERWISE...THE PESKY LOW/TROUGH STRETCHING FROM EASTERN LAKE
SUPERIOR TO ALL OF SOUTHEASTERN ONTARIO WILL EXIT EASTWARD
TODAY...LEAVING A WEAKENING TROUGH ACROSS LAKE SUPERIOR THAT WILL
LINGER THROUGH THURSDAY...AS THE HIGH PRESSURE SYSTEM TO OUR WEST
SINKS INTO THE MID MISSISSIPPI VALLEY. EXPECT LOW PRESSURE ALONG THE
CENTRAL U.S./CANADIAN BORDER FRIDAY TO CROSS LAKE SUPERIOR AND
ONTARIO ON SATURDAY. AHEAD OF THIS LOW...S GUSTS OF 25-30KTS LATE
FRIDAY AFTERNOON INTO SATURDAY MORNING MAY JUMP UP TO GALES
/PARTICULARLY ACROSS E LAKE SUPERIOR FRIDAY NIGHT/.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ002-004-005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006-
007-085.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING UNTIL 9 AM EST WEDNESDAY FOR LSZ243-
244-264-266.
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST WEDNESDAY FOR LSZ248-
265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
WEDNESDAY FOR LSZ241-242-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ249-
250.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...MCD
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
350 AM EST TUE DEC 31 2013
.UPDATE...
ISSUED AT 905 PM EST MON DEC 30 2013
HEAVY LES BAND STILL APPEARS TO BE IMPACTING THE N 1/3 OF HOUGHTON
COUNTY AND FAR SOUTHERN KEWEENAW COUNTY. ISSUED A SPECIAL WX
STATEMENT FOR SOME MDT SN TOTALS OVER SRN KEWEENAW COUNTY.
CONSIDERED AN ADVY BASED ON RECENT REPORT OF SN ACCUMULATING AN
INCH/HR AT MOHAWK...BUT SUSPECT THE RESIDENCE TIME OF THE HEAVIER SN
THERE WL BE MORE LIMITED AS THE LLVL WINDS ARE FCST TO VEER MORE TO
THE NW LATER THIS EVNG. IN HOUGHTON COUNTY...THE HEAVY SN SHOULD
GRDLY SHIFT TO THE S AS THE LLVL FLOW VEERS.
ALSO EXPANDED THE WIND CHILL ADVY INTO MENOMINEE/DELTA COUNTIES
GIVEN EXPECTATION FOR CLRG/LOWER MIN TEMPS THERE FOLLOWING DEPARTURE
OF MID CLDS ASSOCIATED WITH DISTURBANCE PASSING TO THE S. LLVL WINDS
ARE FCST TO INCRS LATER TNGT WITH THE STRONGER CAD BEHIND THIS SYS.
ANY INCRS IN MIXING WL BE COUNTERED BY STRONGER ADVECTION OF THE
BITTERLY COLD AIRMASS UPSTREAM...WHERE TEMPS HAVE ALREADY FALLEN AOB
-30F AT SOME PLACES IN NRN MN.
OVER THE E...LES BANDS ARE STILL OFFSHORE. LATEST HI RES MODEL
GUIDANCE STILL SHOWS THESE BANDS COMING ONSHORE TOWARD LATE EVNG FM
GRAND MARAIS TO CRISP POINT...SO MAINTAINED GOING HEADLINES IN THIS
AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 430 PM EST MON DEC 30 2013
MOST OF UPPER MICHIGAN IS QUIET BUT COLD THIS AFTERNOON...AS THE
AREA IS UNDER LINGERING AFFECTS OF THE HIGH PRESSURE RIDGE THAT
MOVED THROUGH LAST NIGHT INTO THIS MORNING. THIS HAS LED TO WINDS
BACKING TO THE WEST-SOUTHWEST IN THE BOUNDARY LAYER AND FOCUSED THE
REMAINING LAKE EFFECT OVER THE KEWEENAW AND RIGHT ALONG THE
SHORELINE NEAR GRAND MARAIS. CALLS TO THE KEWEENAW THIS AFTERNOON
INDICATE THAT THE FINE FLAKE LES IS STILL IN PLACE. WHILE THIS IS
GOOD AT REDUCING VISIBILITIES...ACCUMULATIONS HAVE BEEN LIGHT AND
UNDER A COUPLE INCHES. OVER THE WEST...TEMPERATURES HAVE STRUGGLE
TO EVEN REACH ZERO DEGREES THIS AFTERNOON...WHICH WILL PAVE THE WAY
FOR ANOTHER NIGHT WILL COLD WIND CHILLS. FARTHER TO THE
SOUTHWEST...A SHORTWAVE IS SLIDING EAST-SOUTHEAST THROUGH MINNESOTA
AT THIS TIME AND IS LEADING TO LIGHT SNOW SHOWERS. THESE -SHSN
SHOULD MISS MUCH OF THE AREA...BUT COULD LEAD TO A FEW FLURRIES
ALONG THE WISCONSIN BORDER.
A WEAK SURFACE TROUGH OVER CENTRAL/SOUTHERN LAKE SUPERIOR AT THIS
TIME WILL BE THE FOCUS FOR THE LAKE EFFECT TONIGHT INTO TUESDAY
MORNING. ALL THE HIGH RESOLUTION MODELS SHOW A MESO-LOW DEVELOPING
OVER THE SOUTHEASTERN LAKE THIS EVENING. A LOOK AT THE MONTREAL
RIVER RADAR THIS AFTERNOON DOESN/T INDICATE ANY CIRCULATION AT THIS
POINT...BUT IT SHOULD BE DEVELOPING THIS EVENING. IN ADDITION...THE
LAKE EFFECT SNOW WILL BE ENHANCED BY A SHORTWAVE MOVING THROUGH THIS
EVENING. THIS WAVE PROVIDES A LITTLE MORE MOISTURE AND MID LEVEL
UPWARD MOTION...ALONG WITH COOLING ALOFT TO WEAKEN THE INVERSION
CURRENTLY AROUND 6-8KFT AND ALLOWS IT TO RISE TO 10-12KFT OVER THE
EASTERN CWA. ALSO...IT HELPS INTENSIFY THE SURFACE TROUGH OR
MESO-LOW OVER THE EASTERN LAKE BEFORE IT SLIDES SOUTHEAST LATE
TONIGHT INTO TUESDAY MORNING (BUT STILL LEAVES A TROUGH OVER THE
EASTERN LAKE). SINCE THIS HAS BEEN SHOWN FOR SEVERAL DAYS
NOW...FAIRLY CONFIDENT ON ITS OCCURRENCE...THE QUESTION COMES DOWN
TO EXACT LOCATION OF THE HEAVIEST BAND AND WHAT THE SNOW RATIOS WILL
BE. LATEST TRENDS IN THE MODELS SHOW A SLIGHTLY LATER ARRIVAL OF
THE STRONG LES BAND ON THE WEST SIDE OF THE MESO-LOW...LIKELY
CLOSER TO 04-06Z. UNFORTUNATELY THE LOCATION IS ALL OVER
THE MAP...WITH SOME HAVE IT HITTING PICTURED ROCKS (AND
NEARLY MUNISING - RAP AND A COUPLE 15Z HOPWRF MEMBERS) WHILE OTHERS
THE FAR NORTHEAST PART OF LUCE COUNTY (2.5 AND 10KM REGIONAL GEMS).
OPTED TO FOCUS ON THE MIDDLE GROUND WHICH WAS SIMILAR TO THE
PREVIOUS FORECAST AND HAVE THE STRONG BAND COME ONSHORE AROUND THE
GRAND MARAIS AREA. PINNING DOWN THIS LOCATION WILL MAKE OR BREAK
SNOWFALL AMOUNTS AND THE POTENTIAL OF REACHING WARNING SNOWFALL
AMOUNTS. ONCE THIS BAND COMES ON SHORE EXPECT A TRANSITION TO A
GENERAL NORTHWEST FLOW LES THROUGH THE DAY ON TUESDAY. WITH A
WEAK SURFACE TROUGH LINGERING OVER THE FAR EASTERN LAKE...MODELS
ARE INDICATING SOME ENHANCED CONVERGENCE TO LEAD TO A STRONGER BAND
AFFECTING NORTHERN LUCE COUNTY...ALTHOUGH THERE WILL BE SOME
WAVERING EXPECTED.
AS FOR SNOW RATIOS AND AMOUNTS...ARCTIC AIR MASS WILL LIKELY BE
MODIFIED SOMEWHAT FROM THE CIRCULATION AND MOISTURE/HEAT FLUX OFF
THE LAKE...WHICH WILL TRY TO PUT SOME OF THE CLOUD INTO THE DGZ.
THUS...WOULD EXPECT SOME HIGHER RATIOS TONIGHT AS THE BAND
COMES ON SHORE AND BEFORE SLIGHTLY COOLER AIR ARRIVES ON
TUESDAY AND TRANSITION BACK TO MORE OF A FINER FLAKE SNOW THAT
WE HAVE SEEN THE LAST 24-48HRS. ON TO AMOUNTS...PREVIOUS FORECAST
WAS RIGHT ON THE EDGE OF BOTH 12/24HR AMOUNTS AND HAVE SIMILAR IF
NOT SLIGHTLY LOWER VALUES FOR THIS FORECAST. THINK THERE WILL BE A
GOOD BURST WITH THAT STRONG BAND TONIGHT INTO TUESDAY MORNING OF 3
TO 7 INCHES. THEN THE TRANSITION TO MORE NORTHWEST WINDS AND
SLIGHTLY LOWER RATIOS SHOULD LEAD TO ANOTHER PERIOD OF 2-6 INCHES
FROM MID MORNING INTO THE EARLY EVENING (BUT LIKELY FOCUSED FARTHER
EAST INTO LUCE COUNTY). THIS IS JUST PUTS THE FORECAST JUST UNDER
BOTH THE 12/24HR WARNING AMOUNTS AND WITH THE UNCERTAINTY IN THE
EXACT LOCATION OF THE HEAVIEST SNOW...WILL ISSUE A STRONGLY WORDED
ADVISORY FOR ALGER/LUCE AND NORTHERN SCHOOLCRAFT FOR TONIGHT INTO
TUESDAY. THAT WAY WE CAN HOPEFULLY GET ONE MORE LOOK AT HIGH RES
RUNS AND IF THERE IS A BETTER HANDLE ON LOCATION AND CONFIDENCE
GROWS ON WARNING AMOUNTS...CAN UPGRADE THIS EVENING OR TONIGHT FOR
THE MORE SPECIFIC LOCATION. WITH ALL OF THE LOCATION
DIFFERENCES...WOULD HATE TO ISSUE A WARNING FOR LUCE AND THEN HAVE
IT STAY MAINLY IN ALGER OR VICE-VERSA.
OVER THE WEST...A SURFACE TROUGH STRETCHED WEST ACROSS SOUTHERN
LAKE SUPERIOR WILL SLOWLY PUSH THE MAIN BAND AFFECTING THE KEWEENAW
SOUTH TONIGHT INTO THE ONTONAGON AND SOUTHERN PORTIONS OF HOUGHTON
COUNTY AREA TONIGHT. AS THIS OCCURS...THE REST OF THE KEWEENAW WILL
TRANSITION TO MORE OF A NW FLOW LAKE EFFECT SCENARIO WHICH WILL
CONTINUE INTO TUESDAY. LESS RESIDENCE TIME OVER WESTERN LAKE
SUPERIOR WILL LIMIT THE ARCTIC AIR MASS MODERATION AND SHOULD KEEP
MOST OF THE CLOUD LAYER ABOVE THE DGZ. THUS...WOULD EXPECT THE
SMALLER SNOW FLAKES AND RATIOS TO CONTINUE THERE AND LIMIT
ACCUMULATIONS. INVERSION HEIGHTS ARE GREATER THAN THE PAST 24HRS
(7-9KFT) WHICH WILL LEAD TO SLIGHTLY STRONGER SHOWERS...BUT ALL OF
THAT CLOUD LAYER WILL BE WELL ABOVE THE DGZ. CURRENT THOUGHT IS
THERE BEING AN INCREASE IN SNOW ACCUMULATION THIS EVENING...BEFORE
COLDER 850MB TEMPS MOVE IN BEHIND THE SHORTWAVE (FALLING TO ALMOST
-26C BY 12Z TUESDAY) AND PUSH ALL OF THE CLOUD ABOVE THE DGZ.
ALTHOUGH TOTAL AMOUNTS OVER THE 24 HOUR PERIOD MAY REACH THE 3-6INCH
RANGE...THINK 12HR AMOUNTS WILL BE HARD PRESSED TO REACH THE 4 INCH
AMOUNT NEEDED FOR A LES ADVISORY.
A COLD START TO THE DAY AND A TIGHTENING SURFACE GRADIENT WITH THE
SURFACE DROPPING SOUTH INTO NORTHERN UPPER MICHIGAN TONIGHT WILL
LEAD TO ANOTHER NIGHT OF VERY COLD WIND CHILLS. THINK THE SCATTERED
HIGH CLOUDS AND SLIGHTLY HIGHER WINDS WILL KEEP TEMPS SLIGHTLY
WARMER THAN LAST NIGHT. BUT THIS WILL ALSO KEEP WIND CHILLS LOW AND
SIMILAR TO LAST NIGHT. THEREFORE...HAVE ISSUED A WIND CHILL
ADVISORY FOR THE SAME LOCATIONS AS LAST NIGHT AND HAVE IT RUNNING
THROUGH LATE TUESDAY MORNING. ONCE AGAIN...TEMPERATURES WILL
STRUGGLE TO REBOUND TOMORROW AND SOME LOCATIONS OUT WEST WILL STAY
IN THE SINGLE DIGITS BELOW ZERO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 430 PM EST MON DEC 30 2013
MODELS ARE CONSISTENT IN SHOWING THE 500MB CLOSED LOW OVER QUEBEC
WEDNESDAY MOVING OFF INTO THE ATLANTIC THURSDAY. THE GFS /AS USUAL/
IS MORE PROGRESSIVE THAN THE ECWMF WITH THE LONGWAVE TROUGH IN THE
WAKE OF THE LOW...BRINGING THE TROUGH THROUGH THE GREAT LAKES ON
THURSDAY AFTERNOON. THE ECMWF IS SLOWER AND DEEPER WITH THIS
TROUGH...WITH IT BEING MAINLY OVER WI ON THURSDAY AFTERNOON.
GUIDANCE SUGGESTS THAT THE ECMWF HAS BEEN ERRING ON THE DEEPER AND
MORE AMPLIFIED SIDE LATELY...HOWEVER...AND THIS MAY BE THE CASE.
OVERALL WENT MIDDLE OF THE ROAD FOR THE FORECAST AT THIS
POINT...LEANING MORE TOWARDS THE ECMWF. AS FAR AS WHAT THIS MEANS
FOR THE SURFACE...LOW PRESSURE DEVELOPS IN THE CENTRAL PLAINS AND
RIDES NORTHEASTWARD ALONG THE TROUGH...WHICH BRINGS AN INVERTED
SURFACE TROUGH INTO UPPER MI FOR WEDNESDAY NIGHT-THURSDAY AFTERNOON.
TUESDAY NIGHT WINDS REMAIN OUT OF THE WEST NORTHWEST THROUGH
MIDNIGHT...BEFORE GRADUALLY VEERING TO THE NORTH AND EVEN NORTHEAST
AS THE INVERTED TROUGH SHIFTS WESTWARD. THIS MOVES THE HIGHEST POPS
FROM THE FAR NORTHEASTERN PORTIONS OF THE COUNTY TOWARDS MUNISING
THROUGH THE NIGHT. BY WEDNESDAY AFTERNOON...CONVERGENCE FOCUSES
BETWEEN MARQUETTE AND MUNISING...WHICH IS WHERE HIGHEST POPS ARE
SITUATED IN THE GRIDS. WHILE THIS REMAINS THE CASE THROUGH THURSDAY
AFTERNOON...TOTAL ACCUMULATIONS ARE GENERALLY EXPECTED TO BE ON THE
ORDER OF 2 TO 4 INCHES BETWEEN SHOT POINT AND MUNISING. GIVEN THAT
MOST OF THE BANDS ARE SHIFTING FROM WEST-NORTHWEST INTO A MORE
NORTH-NORTHEAST PATTERN THROUGH THE PERIOD...NOT REALLY EXPECTING
ANY ONE LOCATION TO RECEIVE TOO MUCH ACCUMULATION. ALSO...BEYOND
WEDNESDAY MORNING...WINDS AT 850-925MB BECOME SOMEWHAT MISALIGNED
WITH THE SURFACE WINDS...WHICH IS TYPICALLY LESS SUITABLE FOR MORE
STRUCTURED BANDS. THOUGH INVERSION HEIGHTS ARE HIGHER WITH COLDER
850MB TEMPS...GENERALLY UP TO 6-8KFT...THE DGZ IS LOW AND SO EXPECT
THE SAME SMALL SIZED FLAKES-AND LOW ACCUMULATIONS LIKE THOSE
OBSERVED ACROSS UPPER MI ALL WEEK/DESPITE SIMILAR INVERSION HEIGHTS.
THE NAM HINTS AT SOME HIGHER SNOW RATIOS OCCURRING IN THE
EAST...HOWEVER...THE NAM HAS BEEN TRENDING HIGHER THROUGH THIS PAST
WEEK THAN WHAT IS BEING OBSERVED. OVERALL...WEVE SEEN AROUND 18-20:1
RATIOS...AND THIS IS WHAT WAS USED FOR THE FORECAST. USING THE
NAM...THE BEST LIFT COLLOCATED WITH THE DGZ IS BETWEEN 6Z AND 15Z
WEDNESDAY AROUND MUNISING...AND SOME BIGGER FLAKES MAY BE SEEN
DURING THIS TIME. OTHERWISE...EXPECT ACCUMULATIONS TO RANGE FROM 1-3
INCHES NEAR THE LAKE FROM 6Z WEDNESDAY TO 12Z THURSDAY.
FRIDAY INTO SATURDAY LOW PRESSURE SLIDING OVER THE CANADIAN PRAIRIE
WILL SWING WINDS AROUND TO THE SOUTH ACROSS UPPER MI...PUSHING ALL
LAKE EFFECT SNOW BANDS OFF INTO LAKE SUPERIOR. 850MB TEMPS WARM AS
WELL...WITH THE ECMWF HINTING AT -8C TO -10C FOR BOTH DAYS. THE COLD
FRONT PASSES ON SATURDAY NIGHT. THE ARCTIC PUSH BEHIND THIS TROUGH
IS NOT TOO BAD...AS TEMPS 850MB TEMPS ARE SOMEWHAT RESCUED BY A
BRIEF RIDGE MOVING FROM THE NORTHERN PLAINS INTO THE GREAT LAKES
THROUGH SUNDAY AFTERNOON. KEPT BROAD CHANCE POPS ACROSS THE CWA FOR
MUCH OF THE FORECAST AREA THROUGH SATURDAY NIGHT. ON SUNDAY...TEMPS
ARE COLD ENOUGH AND WINDS OUT OF THE WEST-NORTHWEST...SO KEPT CHANCE
POPS CONFINED TO LAKE SUPERIOR.
THE MAIN DIFFERENCES BETWEEN MODELS LIE ON MONDAY...WITH THE ECMWF
AND THE GFS BOTH HINTING AT A VERY COLD ARCTIC PUSH OF AIR SLIDING
THROUGH...WITH 850MB TEMPS AS LOW AS -35C OVER UPPER MI. THOUGH THE
GFS IS NOT QUITE AS LOW...IT HAS 850MB TEMPS AT -25C TO -30C FOR THE
AREA. WILL TREND LOWER WITH TEMPS DURING THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1223 AM EST TUE DEC 31 2013
KIWD...AS WINDS VEER FM SW TO WNW IN THE WAKE OF A DISTURBANCE
PASSING TO THE S OF UPR MI...EXPECT SOME LK EFFECT CLDS/-SHSN TO
SPREAD BACK OVER THIS SITE BY SUNRISE. CONDITIONS SHOULD GRDLY
DETERIORATE FM VFR TO MVFR. IFR VSBYS ARE PSBL LATER IN THE DAY IF
THE FLOW VEERS FAR ENUF TO THE NW.
KCMX...VEERING W TO NW FLOW OF ARCTIC AIR WL ALLOW LK EFFECT -SHSN
TO IMPACT THIS LOCATION THIS FCST PERIOD. ALTHOUGH THERE COULD BE
SOME IMPROVEMENT IN VSBYS BTWN THE BANDS...IFR CONDITIONS SHOULD
PREDOMINATE.
SAW...WITH A DOWNSLOPE WSW FLOW OF DRY ARCTIC AIR VEERING TO WNW...
EXPECT VFR CONDITIONS TO PREDOMINATE THIS FCST PERIOD EVEN THOUGH
OCNL FLURRIES/MVFR CIGS WL BE POSSIBLE THIS AFTN/EVNG.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 349 AM EST TUE DEC 31 2013
HEAVY FREEZING SPRAY WILL REMAIN A CONCERN FOR MAINLY CENTRAL AND
EASTERN LAKE SUPERIOR THROUGH EARLY WEDESDAY...AS AIR TEMPS CONTINUE TO
BE IN THE TEENS ABOVE ZERO TO THE SINGLE DIGITS BELOW ZERO...AND NW
TO N WINDS IN THE 20-30KT RANGE.
STRONG HIGH PRESSURE OVER SASKATCHEWAN WILL BUILD INTO MINNESOTA
TONIGHT...AND REMAIN NEARLY STATIONARY THROUGH THURSDAY.
OTHERWISE...THE PESKY LOW/TROUGH STRETCHING FROM EASTERN LAKE
SUPERIOR TO ALL OF SOUTHEASTERN ONTARIO WILL EXIT EASTWARD
TODAY...LEAVING A WEAKENING TROUGH ACROSS LAKE SUPERIOR THAT WILL
LINGER THROUGH THURSDAY...AS THE HIGH PRESSURE SYSTEM TO OUR WEST
SINKS INTO THE MID MISSISSIPPI VALLEY. EXPECT LOW PRESSURE ALONG THE
CENTRAL U.S./CANADIAN BORDER FRIDAY TO CROSS LAKE SUPERIOR AND
ONTARIO ON SATURDAY. AHEAD OF THIS LOW...S GUSTS OF 25-30KTS LATE
FRIDAY AFTERNOON INTO SATURDAY MORNING MAY JUMP UP TO GALES
/PARTICULARLY ACROSS E LAKE SUPERIOR FRIDAY NIGHT/.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ002-004-005-009>013-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006-
007-085.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM THIS EVENING TO 7 AM EST
WEDNESDAY FOR LSZ267.
HEAVY FREEZING SPRAY WARNING UNTIL 9 AM EST WEDNESDAY FOR LSZ243-
244-264-266.
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST WEDNESDAY FOR LSZ248-
265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST /MIDNIGHT CST/
WEDNESDAY FOR LSZ241-242-263.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ249-
250.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...SRF
LONG TERM...MCD
AVIATION...KC
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1223 AM EST TUE DEC 31 2013
.UPDATE...
ISSUED AT 905 PM EST MON DEC 30 2013
HEAVY LES BAND STILL APPEARS TO BE IMPACTING THE N 1/3 OF HOUGHTON
COUNTY AND FAR SOUTHERN KEWEENAW COUNTY. ISSUED A SPECIAL WX
STATEMENT FOR SOME MDT SN TOTALS OVER SRN KEWEENAW COUNTY.
CONSIDERED AN ADVY BASED ON RECENT REPORT OF SN ACCUMULATING AN
INCH/HR AT MOHAWK...BUT SUSPECT THE RESIDENCE TIME OF THE HEAVIER SN
THERE WL BE MORE LIMITED AS THE LLVL WINDS ARE FCST TO VEER MORE TO
THE NW LATER THIS EVNG. IN HOUGHTON COUNTY...THE HEAVY SN SHOULD
GRDLY SHIFT TO THE S AS THE LLVL FLOW VEERS.
ALSO EXPANDED THE WIND CHILL ADVY INTO MENOMINEE/DELTA COUNTIES
GIVEN EXPECTATION FOR CLRG/LOWER MIN TEMPS THERE FOLLOWING DEPARTURE
OF MID CLDS ASSOCIATED WITH DISTURBANCE PASSING TO THE S. LLVL WINDS
ARE FCST TO INCRS LATER TNGT WITH THE STRONGER CAD BEHIND THIS SYS.
ANY INCRS IN MIXING WL BE COUNTERED BY STRONGER ADVECTION OF THE
BITTERLY COLD AIRMASS UPSTREAM...WHERE TEMPS HAVE ALREADY FALLEN AOB
-30F AT SOME PLACES IN NRN MN.
OVER THE E...LES BANDS ARE STILL OFFSHORE. LATEST HI RES MODEL
GUIDANCE STILL SHOWS THESE BANDS COMING ONSHORE TOWARD LATE EVNG FM
GRAND MARAIS TO CRISP POINT...SO MAINTAINED GOING HEADLINES IN THIS
AREA.
&&
.SHORT TERM...(THIS EVENING THROUGH TUESDAY)
ISSUED AT 430 PM EST MON DEC 30 2013
MOST OF UPPER MICHIGAN IS QUIET BUT COLD THIS AFTERNOON...AS THE
AREA IS UNDER LINGERING AFFECTS OF THE HIGH PRESSURE RIDGE THAT
MOVED THROUGH LAST NIGHT INTO THIS MORNING. THIS HAS LED TO WINDS
BACKING TO THE WEST-SOUTHWEST IN THE BOUNDARY LAYER AND FOCUSED THE
REMAINING LAKE EFFECT OVER THE KEWEENAW AND RIGHT ALONG THE
SHORELINE NEAR GRAND MARAIS. CALLS TO THE KEWEENAW THIS AFTERNOON
INDICATE THAT THE FINE FLAKE LES IS STILL IN PLACE. WHILE THIS IS
GOOD AT REDUCING VISIBILITIES...ACCUMULATIONS HAVE BEEN LIGHT AND
UNDER A COUPLE INCHES. OVER THE WEST...TEMPERATURES HAVE STRUGGLE
TO EVEN REACH ZERO DEGREES THIS AFTERNOON...WHICH WILL PAVE THE WAY
FOR ANOTHER NIGHT WILL COLD WIND CHILLS. FARTHER TO THE
SOUTHWEST...A SHORTWAVE IS SLIDING EAST-SOUTHEAST THROUGH MINNESOTA
AT THIS TIME AND IS LEADING TO LIGHT SNOW SHOWERS. THESE -SHSN
SHOULD MISS MUCH OF THE AREA...BUT COULD LEAD TO A FEW FLURRIES
ALONG THE WISCONSIN BORDER.
A WEAK SURFACE TROUGH OVER CENTRAL/SOUTHERN LAKE SUPERIOR AT THIS
TIME WILL BE THE FOCUS FOR THE LAKE EFFECT TONIGHT INTO TUESDAY
MORNING. ALL THE HIGH RESOLUTION MODELS SHOW A MESO-LOW DEVELOPING
OVER THE SOUTHEASTERN LAKE THIS EVENING. A LOOK AT THE MONTREAL
RIVER RADAR THIS AFTERNOON DOESN/T INDICATE ANY CIRCULATION AT THIS
POINT...BUT IT SHOULD BE DEVELOPING THIS EVENING. IN ADDITION...THE
LAKE EFFECT SNOW WILL BE ENHANCED BY A SHORTWAVE MOVING THROUGH THIS
EVENING. THIS WAVE PROVIDES A LITTLE MORE MOISTURE AND MID LEVEL
UPWARD MOTION...ALONG WITH COOLING ALOFT TO WEAKEN THE INVERSION
CURRENTLY AROUND 6-8KFT AND ALLOWS IT TO RISE TO 10-12KFT OVER THE
EASTERN CWA. ALSO...IT HELPS INTENSIFY THE SURFACE TROUGH OR
MESO-LOW OVER THE EASTERN LAKE BEFORE IT SLIDES SOUTHEAST LATE
TONIGHT INTO TUESDAY MORNING (BUT STILL LEAVES A TROUGH OVER THE
EASTERN LAKE). SINCE THIS HAS BEEN SHOWN FOR SEVERAL DAYS
NOW...FAIRLY CONFIDENT ON ITS OCCURRENCE...THE QUESTION COMES DOWN
TO EXACT LOCATION OF THE HEAVIEST BAND AND WHAT THE SNOW RATIOS WILL
BE. LATEST TRENDS IN THE MODELS SHOW A SLIGHTLY LATER ARRIVAL OF
THE STRONG LES BAND ON THE WEST SIDE OF THE MESO-LOW...LIKELY
CLOSER TO 04-06Z. UNFORTUNATELY THE LOCATION IS ALL OVER
THE MAP...WITH SOME HAVE IT HITTING PICTURED ROCKS (AND
NEARLY MUNISING - RAP AND A COUPLE 15Z HOPWRF MEMBERS) WHILE OTHERS
THE FAR NORTHEAST PART OF LUCE COUNTY (2.5 AND 10KM REGIONAL GEMS).
OPTED TO FOCUS ON THE MIDDLE GROUND WHICH WAS SIMILAR TO THE
PREVIOUS FORECAST AND HAVE THE STRONG BAND COME ONSHORE AROUND THE
GRAND MARAIS AREA. PINNING DOWN THIS LOCATION WILL MAKE OR BREAK
SNOWFALL AMOUNTS AND THE POTENTIAL OF REACHING WARNING SNOWFALL
AMOUNTS. ONCE THIS BAND COMES ON SHORE EXPECT A TRANSITION TO A
GENERAL NORTHWEST FLOW LES THROUGH THE DAY ON TUESDAY. WITH A
WEAK SURFACE TROUGH LINGERING OVER THE FAR EASTERN LAKE...MODELS
ARE INDICATING SOME ENHANCED CONVERGENCE TO LEAD TO A STRONGER BAND
AFFECTING NORTHERN LUCE COUNTY...ALTHOUGH THERE WILL BE SOME
WAVERING EXPECTED.
AS FOR SNOW RATIOS AND AMOUNTS...ARCTIC AIR MASS WILL LIKELY BE
MODIFIED SOMEWHAT FROM THE CIRCULATION AND MOISTURE/HEAT FLUX OFF
THE LAKE...WHICH WILL TRY TO PUT SOME OF THE CLOUD INTO THE DGZ.
THUS...WOULD EXPECT SOME HIGHER RATIOS TONIGHT AS THE BAND
COMES ON SHORE AND BEFORE SLIGHTLY COOLER AIR ARRIVES ON
TUESDAY AND TRANSITION BACK TO MORE OF A FINER FLAKE SNOW THAT
WE HAVE SEEN THE LAST 24-48HRS. ON TO AMOUNTS...PREVIOUS FORECAST
WAS RIGHT ON THE EDGE OF BOTH 12/24HR AMOUNTS AND HAVE SIMILAR IF
NOT SLIGHTLY LOWER VALUES FOR THIS FORECAST. THINK THERE WILL BE A
GOOD BURST WITH THAT STRONG BAND TONIGHT INTO TUESDAY MORNING OF 3
TO 7 INCHES. THEN THE TRANSITION TO MORE NORTHWEST WINDS AND
SLIGHTLY LOWER RATIOS SHOULD LEAD TO ANOTHER PERIOD OF 2-6 INCHES
FROM MID MORNING INTO THE EARLY EVENING (BUT LIKELY FOCUSED FARTHER
EAST INTO LUCE COUNTY). THIS IS JUST PUTS THE FORECAST JUST UNDER
BOTH THE 12/24HR WARNING AMOUNTS AND WITH THE UNCERTAINTY IN THE
EXACT LOCATION OF THE HEAVIEST SNOW...WILL ISSUE A STRONGLY WORDED
ADVISORY FOR ALGER/LUCE AND NORTHERN SCHOOLCRAFT FOR TONIGHT INTO
TUESDAY. THAT WAY WE CAN HOPEFULLY GET ONE MORE LOOK AT HIGH RES
RUNS AND IF THERE IS A BETTER HANDLE ON LOCATION AND CONFIDENCE
GROWS ON WARNING AMOUNTS...CAN UPGRADE THIS EVENING OR TONIGHT FOR
THE MORE SPECIFIC LOCATION. WITH ALL OF THE LOCATION
DIFFERENCES...WOULD HATE TO ISSUE A WARNING FOR LUCE AND THEN HAVE
IT STAY MAINLY IN ALGER OR VICE-VERSA.
OVER THE WEST...A SURFACE TROUGH STRETCHED WEST ACROSS SOUTHERN
LAKE SUPERIOR WILL SLOWLY PUSH THE MAIN BAND AFFECTING THE KEWEENAW
SOUTH TONIGHT INTO THE ONTONAGON AND SOUTHERN PORTIONS OF HOUGHTON
COUNTY AREA TONIGHT. AS THIS OCCURS...THE REST OF THE KEWEENAW WILL
TRANSITION TO MORE OF A NW FLOW LAKE EFFECT SCENARIO WHICH WILL
CONTINUE INTO TUESDAY. LESS RESIDENCE TIME OVER WESTERN LAKE
SUPERIOR WILL LIMIT THE ARCTIC AIR MASS MODERATION AND SHOULD KEEP
MOST OF THE CLOUD LAYER ABOVE THE DGZ. THUS...WOULD EXPECT THE
SMALLER SNOW FLAKES AND RATIOS TO CONTINUE THERE AND LIMIT
ACCUMULATIONS. INVERSION HEIGHTS ARE GREATER THAN THE PAST 24HRS
(7-9KFT) WHICH WILL LEAD TO SLIGHTLY STRONGER SHOWERS...BUT ALL OF
THAT CLOUD LAYER WILL BE WELL ABOVE THE DGZ. CURRENT THOUGHT IS
THERE BEING AN INCREASE IN SNOW ACCUMULATION THIS EVENING...BEFORE
COLDER 850MB TEMPS MOVE IN BEHIND THE SHORTWAVE (FALLING TO ALMOST
-26C BY 12Z TUESDAY) AND PUSH ALL OF THE CLOUD ABOVE THE DGZ.
ALTHOUGH TOTAL AMOUNTS OVER THE 24 HOUR PERIOD MAY REACH THE 3-6INCH
RANGE...THINK 12HR AMOUNTS WILL BE HARD PRESSED TO REACH THE 4 INCH
AMOUNT NEEDED FOR A LES ADVISORY.
A COLD START TO THE DAY AND A TIGHTENING SURFACE GRADIENT WITH THE
SURFACE DROPPING SOUTH INTO NORTHERN UPPER MICHIGAN TONIGHT WILL
LEAD TO ANOTHER NIGHT OF VERY COLD WIND CHILLS. THINK THE SCATTERED
HIGH CLOUDS AND SLIGHTLY HIGHER WINDS WILL KEEP TEMPS SLIGHTLY
WARMER THAN LAST NIGHT. BUT THIS WILL ALSO KEEP WIND CHILLS LOW AND
SIMILAR TO LAST NIGHT. THEREFORE...HAVE ISSUED A WIND CHILL
ADVISORY FOR THE SAME LOCATIONS AS LAST NIGHT AND HAVE IT RUNNING
THROUGH LATE TUESDAY MORNING. ONCE AGAIN...TEMPERATURES WILL
STRUGGLE TO REBOUND TOMORROW AND SOME LOCATIONS OUT WEST WILL STAY
IN THE SINGLE DIGITS BELOW ZERO.
.LONG TERM...(TUESDAY NIGHT THROUGH MONDAY)
ISSUED AT 430 PM EST MON DEC 30 2013
MODELS ARE CONSISTENT IN SHOWING THE 500MB CLOSED LOW OVER QUEBEC
WEDNESDAY MOVING OFF INTO THE ATLANTIC THURSDAY. THE GFS /AS USUAL/
IS MORE PROGRESSIVE THAN THE ECWMF WITH THE LONGWAVE TROUGH IN THE
WAKE OF THE LOW...BRINGING THE TROUGH THROUGH THE GREAT LAKES ON
THURSDAY AFTERNOON. THE ECMWF IS SLOWER AND DEEPER WITH THIS
TROUGH...WITH IT BEING MAINLY OVER WI ON THURSDAY AFTERNOON.
GUIDANCE SUGGESTS THAT THE ECMWF HAS BEEN ERRING ON THE DEEPER AND
MORE AMPLIFIED SIDE LATELY...HOWEVER...AND THIS MAY BE THE CASE.
OVERALL WENT MIDDLE OF THE ROAD FOR THE FORECAST AT THIS
POINT...LEANING MORE TOWARDS THE ECMWF. AS FAR AS WHAT THIS MEANS
FOR THE SURFACE...LOW PRESSURE DEVELOPS IN THE CENTRAL PLAINS AND
RIDES NORTHEASTWARD ALONG THE TROUGH...WHICH BRINGS AN INVERTED
SURFACE TROUGH INTO UPPER MI FOR WEDNESDAY NIGHT-THURSDAY AFTERNOON.
TUESDAY NIGHT WINDS REMAIN OUT OF THE WEST NORTHWEST THROUGH
MIDNIGHT...BEFORE GRADUALLY VEERING TO THE NORTH AND EVEN NORTHEAST
AS THE INVERTED TROUGH SHIFTS WESTWARD. THIS MOVES THE HIGHEST POPS
FROM THE FAR NORTHEASTERN PORTIONS OF THE COUNTY TOWARDS MUNISING
THROUGH THE NIGHT. BY WEDNESDAY AFTERNOON...CONVERGENCE FOCUSES
BETWEEN MARQUETTE AND MUNISING...WHICH IS WHERE HIGHEST POPS ARE
SITUATED IN THE GRIDS. WHILE THIS REMAINS THE CASE THROUGH THURSDAY
AFTERNOON...TOTAL ACCUMULATIONS ARE GENERALLY EXPECTED TO BE ON THE
ORDER OF 2 TO 4 INCHES BETWEEN SHOT POINT AND MUNISING. GIVEN THAT
MOST OF THE BANDS ARE SHIFTING FROM WEST-NORTHWEST INTO A MORE
NORTH-NORTHEAST PATTERN THROUGH THE PERIOD...NOT REALLY EXPECTING
ANY ONE LOCATION TO RECEIVE TOO MUCH ACCUMULATION. ALSO...BEYOND
WEDNESDAY MORNING...WINDS AT 850-925MB BECOME SOMEWHAT MISALIGNED
WITH THE SURFACE WINDS...WHICH IS TYPICALLY LESS SUITABLE FOR MORE
STRUCTURED BANDS. THOUGH INVERSION HEIGHTS ARE HIGHER WITH COLDER
850MB TEMPS...GENERALLY UP TO 6-8KFT...THE DGZ IS LOW AND SO EXPECT
THE SAME SMALL SIZED FLAKES-AND LOW ACCUMULATIONS LIKE THOSE
OBSERVED ACROSS UPPER MI ALL WEEK/DESPITE SIMILAR INVERSION HEIGHTS.
THE NAM HINTS AT SOME HIGHER SNOW RATIOS OCCURRING IN THE
EAST...HOWEVER...THE NAM HAS BEEN TRENDING HIGHER THROUGH THIS PAST
WEEK THAN WHAT IS BEING OBSERVED. OVERALL...WEVE SEEN AROUND 18-20:1
RATIOS...AND THIS IS WHAT WAS USED FOR THE FORECAST. USING THE
NAM...THE BEST LIFT COLLOCATED WITH THE DGZ IS BETWEEN 6Z AND 15Z
WEDNESDAY AROUND MUNISING...AND SOME BIGGER FLAKES MAY BE SEEN
DURING THIS TIME. OTHERWISE...EXPECT ACCUMULATIONS TO RANGE FROM 1-3
INCHES NEAR THE LAKE FROM 6Z WEDNESDAY TO 12Z THURSDAY.
FRIDAY INTO SATURDAY LOW PRESSURE SLIDING OVER THE CANADIAN PRAIRIE
WILL SWING WINDS AROUND TO THE SOUTH ACROSS UPPER MI...PUSHING ALL
LAKE EFFECT SNOW BANDS OFF INTO LAKE SUPERIOR. 850MB TEMPS WARM AS
WELL...WITH THE ECMWF HINTING AT -8C TO -10C FOR BOTH DAYS. THE COLD
FRONT PASSES ON SATURDAY NIGHT. THE ARCTIC PUSH BEHIND THIS TROUGH
IS NOT TOO BAD...AS TEMPS 850MB TEMPS ARE SOMEWHAT RESCUED BY A
BRIEF RIDGE MOVING FROM THE NORTHERN PLAINS INTO THE GREAT LAKES
THROUGH SUNDAY AFTERNOON. KEPT BROAD CHANCE POPS ACROSS THE CWA FOR
MUCH OF THE FORECAST AREA THROUGH SATURDAY NIGHT. ON SUNDAY...TEMPS
ARE COLD ENOUGH AND WINDS OUT OF THE WEST-NORTHWEST...SO KEPT CHANCE
POPS CONFINED TO LAKE SUPERIOR.
THE MAIN DIFFERENCES BETWEEN MODELS LIE ON MONDAY...WITH THE ECMWF
AND THE GFS BOTH HINTING AT A VERY COLD ARCTIC PUSH OF AIR SLIDING
THROUGH...WITH 850MB TEMPS AS LOW AS -35C OVER UPPER MI. THOUGH THE
GFS IS NOT QUITE AS LOW...IT HAS 850MB TEMPS AT -25C TO -30C FOR THE
AREA. WILL TREND LOWER WITH TEMPS DURING THIS TIME PERIOD.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z TUESDAY NIGHT)
ISSUED AT 1223 AM EST TUE DEC 31 2013
KIWD...AS WINDS VEER FM SW TO WNW IN THE WAKE OF A DISTURBANCE
PASSING TO THE S OF UPR MI...EXPECT SOME LK EFFECT CLDS/-SHSN TO
SPREAD BACK OVER THIS SITE BY SUNRISE. CONDITIONS SHOULD GRDLY
DETERIORATE FM VFR TO MVFR. IFR VSBYS ARE PSBL LATER IN THE DAY IF
THE FLOW VEERS FAR ENUF TO THE NW.
KCMX...VEERING W TO NW FLOW OF ARCTIC AIR WL ALLOW LK EFFECT -SHSN
TO IMPACT THIS LOCATION THIS FCST PERIOD. ALTHOUGH THERE COULD BE
SOME IMPROVEMENT IN VSBYS BTWN THE BANDS...IFR CONDITIONS SHOULD
PREDOMINATE.
SAW...WITH A DOWNSLOPE WSW FLOW OF DRY ARCTIC AIR VEERING TO WNW...
EXPECT VFR CONDITIONS TO PREDOMINATE THIS FCST PERIOD EVEN THOUGH
OCNL FLURRIES/MVFR CIGS WL BE POSSIBLE THIS AFTN/EVNG.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 430 PM EST MON DEC 30 2013
WEST-NORTHWEST WINDS WILL VEER TO THE NORTHWEST TONIGHT AND BE IN
THE 15-25KT RANGE. THERE COULD BE SOME GUSTS TO 30KTS OVER THE
EASTERN LAKE AS A MESO-LOW DEVELOPS. THESE WINDS WILL CONTINUE TO
PRODUCE SOME AREAS OF HEAVY FREEZING SPRAY AND WILL CONTINUE THE
HEAVY FREEZING SPRAY WARNING INTO WEDNESDAY MORNING OVER THE EAST.
OTHERWISE...LIGHTER WINDS ARE EXPECTED WEDNESDAY AND THURSDAY
BEFORE AN INCREASE OUT OF THE SOUTHWEST ON FRIDAY AND FRIDAY NIGHT.
THERE COULD BE A FEW GALE FORCE GUSTS TO 35KTS WHEN THIS OCCURS.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WIND CHILL ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ002-004-005-009>011-084.
LAKE EFFECT SNOW ADVISORY UNTIL 7 PM EST THIS EVENING FOR MIZ006-
007-085.
LAKE EFFECT SNOW WARNING UNTIL 7 AM EST THIS MORNING FOR MIZ003.
WIND CHILL ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING FOR
MIZ012-013.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST WEDNESDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING FROM 6 AM THIS MORNING TO 4 AM EST
WEDNESDAY FOR LSZ248-265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST WEDNESDAY FOR LSZ243-
244-264.
HEAVY FREEZING SPRAY WARNING UNTIL 10 PM EST /9 PM CST/ THIS
EVENING FOR LSZ241-242-263.
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST WEDNESDAY FOR LSZ249-
250.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...SRF
LONG TERM...MCD
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS BILLINGS MT
1230 PM MST TUE DEC 31 2013
.UPDATE...
ISSUING A QUICK UPDATE THIS AFTERNOON TO ISSUE A WINTER WEATHER
ADVISORY FOR SNOW...FREEZING RAIN...AND VERY SLICK ROADS FOR MUCH
OF THE CWA. HAVE ALREADY GOTTEN REPORTS OF RAINFALL...AND
ACCUMULATING SNOWS...WHICH IS BOUND TO CREATE VERY SLICK ROADS
ACROSS MUCH OF THE REGION. HAVE OPTED TO START INHERITED
ADVISORIES EARLY AND EXTEND THE ENDING TIME THROUGH WEDNESDAY
EVENING TO COVER LINGERING SNOWS ON ALREADY SLICK ROAD CONDITIONS.
CHANGES TO GRIDS CENTERED AROUND INCREASING SNOW AMOUNTS ACROSS
THE REGION. AAG
&&
.SHORT TERM...VALID FOR TDY AND WED...
ACTIVE WEATHER COMING IN THE SHORT TERM WITH BOTH
WIND AND SNOW CONCERNS.
FIRST WIND. LIVINGSTON HAS BEEN HITTING ADVISORY GUSTS FOR SEVERAL
HOURS AND WILL MAKE NO CHANGE TO THE HIGHLIGHT IN PLACE. LEE SIDE
PRESSURE RISES ARE BEGINNING TO REDUCE THE GRADIENT SLOWLY...BUT
WOULD EXPECT HIGH GUSTS TO CONTINUE FOR MUCH OF THE DAY AS SFC
TROF REMAINS IN CENTRAL MT. COULD SEE GUSTS AS HIGH AS 50 MPH AT
BIG TIMBER AND THE BEARTOOTH FOOTHILLS BUT ORIENTATION OF GRADIENT
SHOULD FAVOR LVM MOST TODAY. COLD ADVECTION FROM THE NW SHOULD END
THE HIGHER GAP FLOW GUSTS BY THIS EVENING.
NOW SNOW. SHORTWAVE EMBEDDED IN NW FLOW ALOFT PUSHING INTO
EASTERN MT IS PRODUCING SOME SNOW ACROSS OUR EAST. MOST
INTERESTING FEATURE IS HEAVIER BAND DROPPING INTO NORTHERN
ROSEBUD AND CUSTER COUNTIES AT 10Z...WHICH IS IN REGION OF STRONG
850MB FRONTOGENESIS. EXPECT A BURST OF FAIRLY HEAVY SNOW OVER THE
NEXT FEW HOURS FROM MILES CITY TO BAKER AND EKALAKA...WITH 1 TO 2
INCHES LIKELY BEFORE THE PCPN DIMINISHES BY AROUND SUNRISE.
FURTHER WEST...STRONG DOWNSLOPE WINDS WILL KEEP LOCATIONS FROM
BILLINGS WEST DRY THIS MORNING. CURRENT TEMPERATURE GRADIENT
ACROSS OUR CWA IS IMPRESSIVE WITH BALMY TEMPS AROUND 40F TO OUR
WEST AND ONLY THE LOW TEENS IN OUR EAST.
STRONGER SHORTWAVE ALONG THE NORTHWEST BC COAST WILL PUSH TOWARD
OUR REGION LATER TODAY...WITH FAIRLY STRONG Q-VECTOR CONVERGENCE
EXPECTED TO BEGIN AROUND 00Z. INTERACTION WITH LOW LEVEL SFC
FRONT IS CRITICAL FOR THE PCPN FORECAST FOR TONIGHT. GFS/ECMWF ARE
CONSISTENT IN BRINGING THIS BOUNDARY AS FAR WEST AS BILLINGS AND
SHERIDAN BY 00Z...WHEREAS THE NAM AND RAP ARE SLOWER. UPSTREAM...
NOTE THAT CUT BANK HAS SHIFTED TO THE NE OVER THE PAST COUPLE
HOURS IN RESPONSE TO SLIGHT PRESSURE RISES BUILDING INTO NORTH
CENTRAL MT. GIVEN THIS IN ADDITION TO EAST WINDS AROUND 20 MPH AT
MLS AND BHK ARE STRONGER THAN ANY GUIDANCE SUGGESTS...BELIEVE THE
GFS/EC ARE CORRECT WITH THE FASTER SOUTHWESTWARD EVOLUTION OF
THIS BOUNDARY TODAY. THAT BEING SAID...AFTER THE MORNING SNOW IN
OUR EAST...PCPN SHOULD INCREASE AGAIN THIS AFTERNOON IN RESPONSE
TO INCREASING DEEP LAYER ASCENT...WITH FOCUS OF LOW LEVEL
FRONTOGENESIS AND PCPN SHIFTING TO THE WEST OVER TIME...AND LIKELY
GETTING TO AS FAR WEST AS BILLINGS AND SHERIDAN BY LATE
AFTERNOON. HAVE ADDED THIS DETAIL IN THE WIND AND POP GRIDS.
OUR CENTRAL PARTS SEEM POISED FOR A SNOW EVENT TONIGHT AS NW WAVE
COMES THROUGH. MUST NOTE THAT MID LEVEL LAPSE RATES EXPECTED TO BE
QUITE STEEP...ABOVE 7C/KM FROM 700-500MB...SO EXPECT SOME HEAVY
SNOW ALONG A FRONTOGENETIC BAND...WHICH MAY BE ADDITIONALLY
ENHANCED BY CONVERGENCE IN THE LEE OF THE SNOWIES. TOUGH TO
FIGURE WHERE EXACTLY THIS MIGHT SET UP...BUT BILLINGS IS A
POSSIBILITY. GREATEST CONFIDENCE FOR SEVERAL INCHES OF SNOW IS IN
OUR NW UPSLOPE AREAS TO THE SE OF BILLINGS...IE BIG HORN AND
SHERIDAN COUNTIES. WILL ISSUE ADVISORIES FROM TONIGHT INTO
WEDNESDAY FOR THIS AREA. SFC BOUNDARY SHOULD HANG UP ALONG THE
EAST SIDE OF THE BIG HORN MTNS TONIGHT...SO EXPECT FAIRLY LIGHT
WINDS IN SHERIDAN ITSELF SO COULD BE A GOOD SNOW EVENT THERE.
OVERALL AM THINKING 3-6 INCHES FOR THE FOOTHILLS AND 6-12 OVER THE
BIG HORNS...WHICH ARE OBVIOUSLY FAVORED IN THE MOIST AND UNSTABLE
NW FLOW. SECONDARY PV MAX ROTATES SOUTH INTO EARLY WEDNESDAY SO
WILL TAKE ADVISORY ALL THE WAY TO NOON TOMORROW.
OUR WESTERN LOWER ELEVATIONS WILL SEE VERY LITTLE SNOW DUE TO
PERSISTENT DOWNSLOPE WINDS. WESTERN SLOPES OF THE BEARTOOTH
ABSAROKA AND CRAZY MTNS WILL DO QUITE WELL THOUGH...ON THE ORDER
OF 6-12 INCHES...THOUGH DO NOT SEE A LONG ENOUGH DURATION EVENT TO
WARRANT A WARNING...ESPECIALLY CONSIDERING THE MID LEVEL WINDS
WILL VEER FROM WEST TO NORTHWEST OVER TIME THUS SHIFTING THE
ASPECTS ON WHICH THE HEAVIEST AMTS WILL FALL.
TEMPS TODAY AND TOMORROW WILL CONTINUE TO BE WARMEST IN OUR WEST
AND COLDEST IN OUR EAST...WITH 30 DEGREES OR MORE OF DIFFERENCE.
AS WEDNESDAY SYSTEM DEPARTS WE WILL SEE A RETURN OF ANTICYCLONIC
FLOW ALOFT AND LEE SIDE SFC TROFFING BY WEDNESDAY NIGHT. LOOKS
LIKE POTENTIAL ADVISORY GUSTS ONCE AGAIN AT LIVINGSTON BY LATE
WEDNESDAY NIGHT.
JKL
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
SOME SIGNIFICANT CHANGES TO THE EXTENDED FOR THIS PACKAGE REVOLVE
AROUND THE POTENTIAL ARCTIC SURGE WE WERE LOOKING AT EARLY NEXT
WEEK. THE ECMWF HAS COMPLETELY GONE AWAY FROM THIS SCENARIO
BY BRINGING THE PACIFIC RIDGE FURTHER INLAND THAN THE GFS THEREBY
DEFLECTING THE ARCTIC AIR EASTWARD TO THE DAKOTAS...WHILE THE GFS
HAS THE COLD AIR ENTRENCHED UP AGAINST THE DIVIDE. THE 12Z ECMWF
STARTED HINTING AT THIS TREND SO THE 00Z ECMWF IS NOT A SURPRISE.
ENSEMBLE SPREADS ARE NOT QUITE AS WIDE AS THE 12Z RUN OF THE
ECMWF. OUR EXTREME FORECAST INDEX POINTS TO THE DAKOTAS AS WHERE
THE BULK OF THE COLDEST AIR WILL GO AS WELL. IN ORDER TO REMOVE
THE RISK OF LARGE FORECAST ERRORS WE WILL TREND THE FORECAST TO A
BLEND DOMINATED BY THE ECMWF...THUS INCREASING OUR TEMPERATURE
FORECASTS QUITE A BIT FOR EARLY NEXT WEEK ACROSS MAINLY OUR
WESTERN ZONES. HOWEVER...WE WILL REMAIN LEARY OF A POTENTIAL
SWITCH IN THE ECMWF. CHANGES WILL ALSO BE REFLECTED BY LOWERING
POPS A BIT FOR EARLY NEXT WEEK. BT
&&
.AVIATION...
STRONG SOUTHWEST WINDS WILL CONTINUE AT LIVINGSTON THIS MORNING
WITH GUSTS OVER 50 KNOTS AT TIMES. THESE WINDS WILL DECREASE BY
18Z. AREAS OF LIGHT SNOW CAUSING MVFR TO IFR CONDITIONS WILL
CONTINUE FROM MILES CITY EASTWARD BEFORE IMPROVING BY 00Z. SOUTH
CENTRAL MONTANA FROM BILLINGS WEST WILL HAVE LOWERING CEILINGS AND
AREAS OF SNOW DEVELOPING AFTER 18Z TODAY. THESE CONDITIONS WILL
SPREAD INTO LIVINGSTON AND SHERIDAN THIS EVENING. MVFR TO LOCAL
LIFR CONDITIONS WILL BE POSSIBLE AS WELL AS MOUNTAIN OBSCURATIONS.
RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 040 021/032 020/042 030/048 020/029 017/016 904/014
7/W 95/J 00/B 03/W 31/B 13/S 32/J
LVM 041 027/036 028/043 033/046 017/029 012/021 901/019
5/W 62/J 01/N 03/W 31/B 23/S 22/J
HDN 039 017/030 014/035 024/046 014/028 011/016 908/012
7/S 96/S 00/B 03/W 31/B 23/S 32/J
MLS 014 005/019 006/028 020/042 012/022 008/008 915/004
8/S 74/S 10/B 04/W 42/B 34/S 21/B
4BQ 032 013/026 005/032 021/046 015/024 011/014 911/010
8/S 85/S 10/B 03/W 41/B 24/S 32/J
BHK 011 000/013 903/026 018/043 012/019 003/005 916/000
8/S 74/S 10/B 04/W 51/B 23/S 21/B
SHR 041 018/030 011/040 022/049 015/027 011/019 906/016
5/W 97/S 00/B 02/W 32/B 24/S 32/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MST WEDNESDAY
FOR ZONES 28>38-41-42-57-58-63.
WIND ADVISORY IN EFFECT UNTIL 5 PM MST THIS AFTERNOON FOR
ZONE 65.
WY...WINTER WEATHER ADVISORY IN EFFECT UNTIL 6 PM MST WEDNESDAY
FOR ZONES 98-99.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
916 AM MST TUE DEC 31 2013
.UPDATE...
MINOR UPDATE THIS MORNING TO ADJUST SOME OF THE TEMPERATURES IN
THE EAST DOWNWARD. WE HAVE ALREADY HIT THE HIGH TEMPERATURE FOR
THE DAY ACROSS MUCH OF THE REGION...AS A BACKDOOR COLD FRONT SAGS
INTO THE REGION. WE ARE CURRENTLY WATCHING VERY CLOSELY WHERE THE
FRONT MANAGES TO BACK INTO...AS THIS WILL LIKELY BE THE BEST
POTENTIAL FOR AN AREA OF HEAVIER SNOW TONIGHT. AAG
&&
.SHORT TERM...VALID FOR TDY AND WED...
ACTIVE WEATHER COMING IN THE SHORT TERM WITH BOTH WIND AND SNOW
CONCERNS.
FIRST WIND. LIVINGSTON HAS BEEN HITTING ADVISORY GUSTS FOR SEVERAL
HOURS AND WILL MAKE NO CHANGE TO THE HIGHLIGHT IN PLACE. LEE SIDE
PRESSURE RISES ARE BEGINNING TO REDUCE THE GRADIENT SLOWLY...BUT
WOULD EXPECT HIGH GUSTS TO CONTINUE FOR MUCH OF THE DAY AS SFC
TROF REMAINS IN CENTRAL MT. COULD SEE GUSTS AS HIGH AS 50 MPH AT
BIG TIMBER AND THE BEARTOOTH FOOTHILLS BUT ORIENTATION OF GRADIENT
SHOULD FAVOR LVM MOST TODAY. COLD ADVECTION FROM THE NW SHOULD END
THE HIGHER GAP FLOW GUSTS BY THIS EVENING.
NOW SNOW. SHORTWAVE EMBEDDED IN NW FLOW ALOFT PUSHING INTO
EASTERN MT IS PRODUCING SOME SNOW ACROSS OUR EAST. MOST
INTERESTING FEATURE IS HEAVIER BAND DROPPING INTO NORTHERN
ROSEBUD AND CUSTER COUNTIES AT 10Z...WHICH IS IN REGION OF STRONG
850MB FRONTOGENESIS. EXPECT A BURST OF FAIRLY HEAVY SNOW OVER THE
NEXT FEW HOURS FROM MILES CITY TO BAKER AND EKALAKA...WITH 1 TO 2
INCHES LIKELY BEFORE THE PCPN DIMINISHES BY AROUND SUNRISE.
FURTHER WEST...STRONG DOWNSLOPE WINDS WILL KEEP LOCATIONS FROM
BILLINGS WEST DRY THIS MORNING. CURRENT TEMPERATURE GRADIENT
ACROSS OUR CWA IS IMPRESSIVE WITH BALMY TEMPS AROUND 40F TO OUR
WEST AND ONLY THE LOW TEENS IN OUR EAST.
STRONGER SHORTWAVE ALONG THE NORTHWEST BC COAST WILL PUSH TOWARD
OUR REGION LATER TODAY...WITH FAIRLY STRONG Q-VECTOR CONVERGENCE
EXPECTED TO BEGIN AROUND 00Z. INTERACTION WITH LOW LEVEL SFC
FRONT IS CRITICAL FOR THE PCPN FORECAST FOR TONIGHT. GFS/ECMWF ARE
CONSISTENT IN BRINGING THIS BOUNDARY AS FAR WEST AS BILLINGS AND
SHERIDAN BY 00Z...WHEREAS THE NAM AND RAP ARE SLOWER. UPSTREAM...
NOTE THAT CUT BANK HAS SHIFTED TO THE NE OVER THE PAST COUPLE
HOURS IN RESPONSE TO SLIGHT PRESSURE RISES BUILDING INTO NORTH
CENTRAL MT. GIVEN THIS IN ADDITION TO EAST WINDS AROUND 20 MPH AT
MLS AND BHK ARE STRONGER THAN ANY GUIDANCE SUGGESTS...BELIEVE THE
GFS/EC ARE CORRECT WITH THE FASTER SOUTHWESTWARD EVOLUTION OF
THIS BOUNDARY TODAY. THAT BEING SAID...AFTER THE MORNING SNOW IN
OUR EAST...PCPN SHOULD INCREASE AGAIN THIS AFTERNOON IN RESPONSE
TO INCREASING DEEP LAYER ASCENT...WITH FOCUS OF LOW LEVEL
FRONTOGENESIS AND PCPN SHIFTING TO THE WEST OVER TIME...AND LIKELY
GETTING TO AS FAR WEST AS BILLINGS AND SHERIDAN BY LATE
AFTERNOON. HAVE ADDED THIS DETAIL IN THE WIND AND POP GRIDS.
OUR CENTRAL PARTS SEEM POISED FOR A SNOW EVENT TONIGHT AS NW WAVE
COMES THROUGH. MUST NOTE THAT MID LEVEL LAPSE RATES EXPECTED TO BE
QUITE STEEP...ABOVE 7C/KM FROM 700-500MB...SO EXPECT SOME HEAVY
SNOW ALONG A FRONTOGENETIC BAND...WHICH MAY BE ADDITIONALLY
ENHANCED BY CONVERGENCE IN THE LEE OF THE SNOWIES. TOUGH TO
FIGURE WHERE EXACTLY THIS MIGHT SET UP...BUT BILLINGS IS A
POSSIBILITY. GREATEST CONFIDENCE FOR SEVERAL INCHES OF SNOW IS IN
OUR NW UPSLOPE AREAS TO THE SE OF BILLINGS...IE BIG HORN AND
SHERIDAN COUNTIES. WILL ISSUE ADVISORIES FROM TONIGHT INTO
WEDNESDAY FOR THIS AREA. SFC BOUNDARY SHOULD HANG UP ALONG THE
EAST SIDE OF THE BIG HORN MTNS TONIGHT...SO EXPECT FAIRLY LIGHT
WINDS IN SHERIDAN ITSELF SO COULD BE A GOOD SNOW EVENT THERE.
OVERALL AM THINKING 3-6 INCHES FOR THE FOOTHILLS AND 6-12 OVER THE
BIG HORNS...WHICH ARE OBVIOUSLY FAVORED IN THE MOIST AND UNSTABLE
NW FLOW. SECONDARY PV MAX ROTATES SOUTH INTO EARLY WEDNESDAY SO
WILL TAKE ADVISORY ALL THE WAY TO NOON TOMORROW.
OUR WESTERN LOWER ELEVATIONS WILL SEE VERY LITTLE SNOW DUE TO
PERSISTENT DOWNSLOPE WINDS. WESTERN SLOPES OF THE BEARTOOTH
ABSAROKA AND CRAZY MTNS WILL DO QUITE WELL THOUGH...ON THE ORDER
OF 6-12 INCHES...THOUGH DO NOT SEE A LONG ENOUGH DURATION EVENT TO
WARRANT A WARNING...ESPECIALLY CONSIDERING THE MID LEVEL WINDS
WILL VEER FROM WEST TO NORTHWEST OVER TIME THUS SHIFTING THE
ASPECTS ON WHICH THE HEAVIEST AMTS WILL FALL.
TEMPS TODAY AND TOMORROW WILL CONTINUE TO BE WARMEST IN OUR WEST
AND COLDEST IN OUR EAST...WITH 30 DEGREES OR MORE OF DIFFERENCE.
AS WEDNESDAY SYSTEM DEPARTS WE WILL SEE A RETURN OF ANTICYCLONIC
FLOW ALOFT AND LEE SIDE SFC TROFFING BY WEDNESDAY NIGHT. LOOKS
LIKE POTENTIAL ADVISORY GUSTS ONCE AGAIN AT LIVINGSTON BY LATE
WEDNESDAY NIGHT.
JKL
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
SOME SIGNIFICANT CHANGES TO THE EXTENDED FOR THIS PACKAGE REVOLVE
AROUND THE POTENTIAL ARCTIC SURGE WE WERE LOOKING AT EARLY NEXT
WEEK. THE ECMWF HAS COMPLETELY GONE AWAY FROM THIS SCENARIO
BY BRINGING THE PACIFIC RIDGE FURTHER INLAND THAN THE GFS THEREBY
DEFLECTING THE ARCTIC AIR EASTWARD TO THE DAKOTAS...WHILE THE GFS
HAS THE COLD AIR ENTRENCHED UP AGAINST THE DIVIDE. THE 12Z ECMWF
STARTED HINTING AT THIS TREND SO THE 00Z ECMWF IS NOT A SURPRISE.
ENSEMBLE SPREADS ARE NOT QUITE AS WIDE AS THE 12Z RUN OF THE
ECMWF. OUR EXTREME FORECAST INDEX POINTS TO THE DAKOTAS AS WHERE
THE BULK OF THE COLDEST AIR WILL GO AS WELL. IN ORDER TO REMOVE
THE RISK OF LARGE FORECAST ERRORS WE WILL TREND THE FORECAST TO A
BLEND DOMINATED BY THE ECMWF...THUS INCREASING OUR TEMPERATURE
FORECASTS QUITE A BIT FOR EARLY NEXT WEEK ACROSS MAINLY OUR
WESTERN ZONES. HOWEVER...WE WILL REMAIN LEARY OF A POTENTIAL
SWITCH IN THE ECMWF. CHANGES WILL ALSO BE REFLECTED BY LOWERING
POPS A BIT FOR EARLY NEXT WEEK. BT
&&
.AVIATION...
STRONG SOUTHWEST WINDS WILL CONTINUE AT LIVINGSTON THIS MORNING
WITH GUSTS OVER 50 KNOTS AT TIMES. THESE WINDS WILL DECREASE BY
18Z. AREAS OF LIGHT SNOW CAUSING MVFR TO IFR CONDITIONS WILL
CONTINUE FROM MILES CITY EASTWARD BEFORE IMPROVING BY 00Z. SOUTH
CENTRAL MONTANA FROM BILLINGS WEST WILL HAVE LOWERING CEILINGS AND
AREAS OF SNOW DEVELOPING AFTER 18Z TODAY. THESE CONDITIONS WILL
SPREAD INTO LIVINGSTON AND SHERIDAN THIS EVENING. MVFR TO LOCAL
LIFR CONDITIONS WILL BE POSSIBLE AS WELL AS MOUNTAIN OBSCURATIONS.
RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 040 021/032 020/042 030/047 020/029 017/020 902/015
7/W 95/S 00/B 03/W 30/B 13/S 32/J
LVM 041 027/036 028/043 033/044 017/030 012/024 001/020
5/W 62/S 01/N 03/W 31/B 23/S 22/J
HDN 039 017/030 014/035 024/046 014/027 011/020 906/013
7/S 95/S 00/B 03/W 31/B 23/S 32/J
MLS 014 005/019 006/028 020/041 012/023 008/011 912/007
9/S 54/S 10/B 04/W 41/B 24/S 21/B
4BQ 032 013/026 005/032 021/047 015/024 011/018 909/012
9/S 85/S 10/B 03/W 41/B 24/S 32/J
BHK 011 000/013 903/026 018/041 012/019 003/006 914/003
+/S 43/S 10/B 04/W 51/B 23/S 21/B
SHR 041 018/030 011/040 022/051 015/028 011/022 904/016
5/W 96/S 00/B 02/W 31/B 24/S 32/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
NOON MST WEDNESDAY FOR ZONE 38.
WIND ADVISORY IN EFFECT UNTIL 5 PM MST THIS AFTERNOON FOR
ZONE 65.
WY...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
NOON MST WEDNESDAY FOR ZONE 99.
WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO
NOON MST WEDNESDAY FOR ZONE 98.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
317 AM MST TUE DEC 31 2013
.SHORT TERM...VALID FOR TDY AND WED...
ACTIVE WEATHER COMING IN THE SHORT TERM WITH BOTH WIND AND SNOW
CONCERNS.
FIRST WIND. LIVINGSTON HAS BEEN HITTING ADVISORY GUSTS FOR SEVERAL
HOURS AND WILL MAKE NO CHANGE TO THE HIGHLIGHT IN PLACE. LEE SIDE
PRESSURE RISES ARE BEGINNING TO REDUCE THE GRADIENT SLOWLY...BUT
WOULD EXPECT HIGH GUSTS TO CONTINUE FOR MUCH OF THE DAY AS SFC
TROF REMAINS IN CENTRAL MT. COULD SEE GUSTS AS HIGH AS 50 MPH AT
BIG TIMBER AND THE BEARTOOTH FOOTHILLS BUT ORIENTATION OF GRADIENT
SHOULD FAVOR LVM MOST TODAY. COLD ADVECTION FROM THE NW SHOULD END
THE HIGHER GAP FLOW GUSTS BY THIS EVENING.
NOW SNOW. SHORTWAVE EMBEDDED IN NW FLOW ALOFT PUSHING INTO
EASTERN MT IS PRODUCING SOME SNOW ACROSS OUR EAST. MOST
INTERESTING FEATURE IS HEAVIER BAND DROPPING INTO NORTHERN
ROSEBUD AND CUSTER COUNTIES AT 10Z...WHICH IS IN REGION OF STRONG
850MB FRONTOGENESIS. EXPECT A BURST OF FAIRLY HEAVY SNOW OVER THE
NEXT FEW HOURS FROM MILES CITY TO BAKER AND EKALAKA...WITH 1 TO 2
INCHES LIKELY BEFORE THE PCPN DIMINISHES BY AROUND SUNRISE.
FURTHER WEST...STRONG DOWNSLOPE WINDS WILL KEEP LOCATIONS FROM
BILLINGS WEST DRY THIS MORNING. CURRENT TEMPERATURE GRADIENT
ACROSS OUR CWA IS IMPRESSIVE WITH BALMY TEMPS AROUND 40F TO OUR
WEST AND ONLY THE LOW TEENS IN OUR EAST.
STRONGER SHORTWAVE ALONG THE NORTHWEST BC COAST WILL PUSH TOWARD
OUR REGION LATER TODAY...WITH FAIRLY STRONG Q-VECTOR CONVERGENCE
EXPECTED TO BEGIN AROUND 00Z. INTERACTION WITH LOW LEVEL SFC
FRONT IS CRITICAL FOR THE PCPN FORECAST FOR TONIGHT. GFS/ECMWF ARE
CONSISTENT IN BRINGING THIS BOUNDARY AS FAR WEST AS BILLINGS AND
SHERIDAN BY 00Z...WHEREAS THE NAM AND RAP ARE SLOWER. UPSTREAM...
NOTE THAT CUT BANK HAS SHIFTED TO THE NE OVER THE PAST COUPLE
HOURS IN RESPONSE TO SLIGHT PRESSURE RISES BUILDING INTO NORTH
CENTRAL MT. GIVEN THIS IN ADDITION TO EAST WINDS AROUND 20 MPH AT
MLS AND BHK ARE STRONGER THAN ANY GUIDANCE SUGGESTS...BELIEVE THE
GFS/EC ARE CORRECT WITH THE FASTER SOUTHWESTWARD EVOLUTION OF
THIS BOUNDARY TODAY. THAT BEING SAID...AFTER THE MORNING SNOW IN
OUR EAST...PCPN SHOULD INCREASE AGAIN THIS AFTERNOON IN RESPONSE
TO INCREASING DEEP LAYER ASCENT...WITH FOCUS OF LOW LEVEL
FRONTOGENESIS AND PCPN SHIFTING TO THE WEST OVER TIME...AND LIKELY
GETTING TO AS FAR WEST AS BILLINGS AND SHERIDAN BY LATE
AFTERNOON. HAVE ADDED THIS DETAIL IN THE WIND AND POP GRIDS.
OUR CENTRAL PARTS SEEM POISED FOR A SNOW EVENT TONIGHT AS NW WAVE
COMES THROUGH. MUST NOTE THAT MID LEVEL LAPSE RATES EXPECTED TO BE
QUITE STEEP...ABOVE 7C/KM FROM 700-500MB...SO EXPECT SOME HEAVY
SNOW ALONG A FRONTOGENETIC BAND...WHICH MAY BE ADDITIONALLY
ENHANCED BY CONVERGENCE IN THE LEE OF THE SNOWIES. TOUGH TO
FIGURE WHERE EXACTLY THIS MIGHT SET UP...BUT BILLINGS IS A
POSSIBILITY. GREATEST CONFIDENCE FOR SEVERAL INCHES OF SNOW IS IN
OUR NW UPSLOPE AREAS TO THE SE OF BILLINGS...IE BIG HORN AND
SHERIDAN COUNTIES. WILL ISSUE ADVISORIES FROM TONIGHT INTO
WEDNESDAY FOR THIS AREA. SFC BOUNDARY SHOULD HANG UP ALONG THE
EAST SIDE OF THE BIG HORN MTNS TONIGHT...SO EXPECT FAIRLY LIGHT
WINDS IN SHERIDAN ITSELF SO COULD BE A GOOD SNOW EVENT THERE.
OVERALL AM THINKING 3-6 INCHES FOR THE FOOTHILLS AND 6-12 OVER THE
BIG HORNS...WHICH ARE OBVIOUSLY FAVORED IN THE MOIST AND UNSTABLE
NW FLOW. SECONDARY PV MAX ROTATES SOUTH INTO EARLY WEDNESDAY SO
WILL TAKE ADVISORY ALL THE WAY TO NOON TOMORROW.
OUR WESTERN LOWER ELEVATIONS WILL SEE VERY LITTLE SNOW DUE TO
PERSISTENT DOWNSLOPE WINDS. WESTERN SLOPES OF THE BEARTOOTH
ABSAROKA AND CRAZY MTNS WILL DO QUITE WELL THOUGH...ON THE ORDER
OF 6-12 INCHES...THOUGH DO NOT SEE A LONG ENOUGH DURATION EVENT TO
WARRANT A WARNING...ESPECIALLY CONSIDERING THE MID LEVEL WINDS
WILL VEER FROM WEST TO NORTHWEST OVER TIME THUS SHIFTING THE
ASPECTS ON WHICH THE HEAVIEST AMTS WILL FALL.
TEMPS TODAY AND TOMORROW WILL CONTINUE TO BE WARMEST IN OUR WEST
AND COLDEST IN OUR EAST...WITH 30 DEGREES OR MORE OF DIFFERENCE.
AS WEDNESDAY SYSTEM DEPARTS WE WILL SEE A RETURN OF ANTICYCLONIC
FLOW ALOFT AND LEE SIDE SFC TROFFING BY WEDNESDAY NIGHT. LOOKS
LIKE POTENTIAL ADVISORY GUSTS ONCE AGAIN AT LIVINGSTON BY LATE
WEDNESDAY NIGHT.
JKL
.LONG TERM...VALID FOR THU...FRI...SAT...SUN...MON...
SOME SIGNIFICANT CHANGES TO THE EXTENDED FOR THIS PACKAGE REVOLVE
AROUND THE POTENTIAL ARCTIC SURGE WE WERE LOOKING AT EARLY NEXT
WEEK. THE ECMWF HAS COMPLETELY GONE AWAY FROM THIS SCENARIO
BY BRINGING THE PACIFIC RIDGE FURTHER INLAND THAN THE GFS THEREBY
DEFLECTING THE ARCTIC AIR EASTWARD TO THE DAKOTAS...WHILE THE GFS
HAS THE COLD AIR ENTRENCHED UP AGAINST THE DIVIDE. THE 12Z ECMWF
STARTED HINTING AT THIS TREND SO THE 00Z ECMWF IS NOT A SURPRISE.
ENSEMBLE SPREADS ARE NOT QUITE AS WIDE AS THE 12Z RUN OF THE
ECMWF. OUR EXTREME FORECAST INDEX POINTS TO THE DAKOTAS AS WHERE
THE BULK OF THE COLDEST AIR WILL GO AS WELL. IN ORDER TO REMOVE
THE RISK OF LARGE FORECAST ERRORS WE WILL TREND THE FORECAST TO A
BLEND DOMINATED BY THE ECMWF...THUS INCREASING OUR TEMPERATURE
FORECASTS QUITE A BIT FOR EARLY NEXT WEEK ACROSS MAINLY OUR
WESTERN ZONES. HOWEVER...WE WILL REMAIN LEARY OF A POTENTIAL
SWITCH IN THE ECMWF. CHANGES WILL ALSO BE REFLECTED BY LOWERING
POPS A BIT FOR EARLY NEXT WEEK. BT
&&
.AVIATION...
STRONG SW WINDS WILL CONTINUE AT KLVM THIS MORNING WITH GUSTS
OVER 50 KNOTS AT TIMES. THESE WINDS WILL DECREASE BY 18Z. AREAS OF
LIGHT SNOW AND LOCAL CONDITIONS DOWN TO IFR WILL CONTINUE FROM
KMLS EASTWARD BEFORE IMPROVING BY 00Z. A LITTLE FURTHER WEST...LOWERING
CEILINGS AND AREAS OF SNOW ARE EXPECTED TO INCREASE OVER SOUTH
CENTRAL MONTANA THIS AFTERNOON AND INTO THE EVENING AFFECTING KLVM
AND KBIL AS WELL AS KSHR AND THE BIG HORN MOUNTAINS REGION. MVFR
TO LOCAL LIFR SHOULD BE EXPECTED WITH MOUNTAIN OBSCURATIONS. BT
&&
.PRELIMINARY POINT TEMP/POPS...
TDY WED THU FRI SAT SUN MON
-------------------------------------------------------
BIL 040 021/032 020/042 030/047 020/029 017/020 902/015
7/W 95/S 00/B 03/W 30/B 13/S 32/J
LVM 041 027/036 028/043 033/044 017/030 012/024 001/020
5/W 62/S 01/N 03/W 31/B 23/S 22/J
HDN 039 017/030 014/035 024/046 014/027 011/020 906/013
7/S 95/S 00/B 03/W 31/B 23/S 32/J
MLS 017 005/019 006/028 020/041 012/023 008/011 912/007
8/S 54/S 10/B 04/W 41/B 24/S 21/B
4BQ 032 013/026 005/032 021/047 015/024 011/018 909/012
8/S 85/S 10/B 03/W 41/B 24/S 32/J
BHK 015 000/013 903/026 018/041 012/019 003/006 914/003
+/S 43/S 10/B 04/W 51/B 23/S 21/B
SHR 041 018/030 011/040 022/051 015/028 011/022 904/016
5/W 96/S 00/B 02/W 31/B 24/S 32/J
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
NOON MST WEDNESDAY FOR ZONE 38.
WIND ADVISORY IN EFFECT UNTIL 5 PM MST THIS AFTERNOON FOR
ZONE 65.
WY...WINTER WEATHER ADVISORY IN EFFECT FROM 5 PM THIS AFTERNOON TO
NOON MST WEDNESDAY FOR ZONE 99.
WINTER WEATHER ADVISORY IN EFFECT FROM 3 PM THIS AFTERNOON TO
NOON MST WEDNESDAY FOR ZONE 98.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION...UPDATED
NWS NORTH PLATTE NE
532 PM CST WED JAN 1 2014
.SYNOPSIS...
ISSUED AT 328 PM CST WED JAN 1 2014
H5 HAND ANALYSIS THIS MORNING...HAS A LONGWAVE TROUGH
ACROSS THE ENTIRE CONUS...WITH LOW PRESSURE NOTED OVER CENTRAL
QUEBEC. LOW PRESSURE WAS PRESENT OVER THE BERING SEA WITH A RIDGE
EXTENDING INTO THE YUKON. ACROSS THE CENTRAL ROCKIES AND HIGH PLAINS
OF NEBRASKA AND KANSAS...HT FALLS OF 50 TO 80 METERS WERE NOTED THIS
MORNING WITH A SHORTWAVE TROUGH OVER EASTERN COLORADO. A JET STREAK
EXTENDED FROM SOUTH DAKOTA EAST INTO THE MID ATLANTIC STATES. TWO
AREAS OF SNOW WERE IMPACTING THE CENTRAL PLAINS THIS AFTERNOON. THE
FIRST OVER KANSAS IN ASSOCIATION WITH THE SHORTWAVE...AND THE SECOND
AREA OVER THE NEBRASKA PANHANDLE...EASTERN WYOMING AND NERN COLORADO
IN ASSOCIATION WITH THE MID LEVEL JET STREAK. AT THE SURFACE...AN
ARCTIC COLD FRONT EXTENDED FROM NORTHWESTERN TEXAS INTO THE OZARKS
AND WEST ALONG THE SOUTHERN AND CENTRAL ROCKIES. UNDER CLOUDY
SKIES...TEMPERATURES AS OF 2 PM CST RANGED FROM 7 AT O`NEILL...TO 31
AT OGALLALA.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 328 PM CST WED JAN 1 2014
SHORTWAVE ENERGY NOW OVER WYOMING AND COLORADO WILL DIVE INTO
KANSAS/OKLAHOMA THROUGH THIS EVENING. AS OF 20Z...THE SNOW ACROSS
THE LOCAL AREA HAS MOVED OUT WITH THE EXCEPTION OF THE SOUTHERN
PANHANDLE...WITH MORE WIDESPREAD SNOW FURTHER WEST INTO WYOMING AND
COLORADO. AS THE SHORTWAVE DIGS SOUTH...THE UPPER LEVEL JET STREAK
OVER WYOMING WILL TRANSITION EAST AND WEAKEN. THIS WILL CAUSE A
DECREASE IN THE LARGE SCALE OMEGA. ALSO...THE DEEPER MOISTURE WILL
GET PUSHED OUT OF THE AREA...WHICH WILL LEAD TO A DIMINISHING TREND
IN THE SNOW INTO THIS EVENING. THE UPPER LEVEL JET WILL STRENGTHEN
OVER WESTERN SOUTH DAKOTA TONIGHT AS ANOTHER SHORTWAVE TROUGH DIGS
SOUTH INTO THE PLAINS FROM WESTERN SASKATCHEWAN. ENHANCED LIFT WILL
OCCUR AHEAD OF THIS NEXT SYSTEM...WHICH WILL LIKELY CAUSE SOME LIGHT
SNOW TO DEVELOP OVER SOUTH DAKOTA AND INTO NORTH CENTRAL NEBRASKA.
THE FORCING INTO NEBRASKA IS QUITE LIGHT SO DON/T THINK THERE WILL
BE MUCH/IF ANY ACCUMULATING SNOW SO KEPT CHANCES LOW OR JUST PUT
FLURRIES IN THE FORECAST. ANY SNOW WITH THIS FEATURE TONIGHT SHOULD
BE CONFINED TO LOCATIONS EAST OF A LINE FROM CODY TO BURWELL.
LOCATIONS TO THE SOUTH AND WEST WILL SEE SKIES CLEAR TONIGHT AND
WITH LIGHT WINDS WILL GET DECENT RADIATIONAL COOLING TO ASSIST WITH
THE TEMPERATURE DROP TONIGHT. THE SURFACE FRONT TO THE WEST OF THE
FORECAST AREA THIS AFTERNOON WILL PUSH EAST TONIGHT AND BY 12Z
THURSDAY SHOULD ROUGHLY BE FROM KVTN TO KBBW. THE WARMER AIR MOVING
IN BEHIND THE FRONT WILL KEEP THE TEMPERATURES FROM COOLING TOO MUCH
OVERNIGHT...YET WITH THE COOLING WILL STILL DROP DOWN INTO THE
SINGLE DIGITS AND LOW TEENS. TO THE EAST OF THE FRONT...THE ARCTIC
AIR WILL HOLD STEADY AND EXPECT LOWS IN THE LOW SINGLE DIGITS...AS
CLOUD COVER WILL HELP KEEP THEM FROM A SIGNIFICANT DROP.
ON THURSDAY...THE FORECAST AREA WILL AGAIN BE SPLIT BY AIRMASSES.
WARM AIR ADVECTION AT 850MB WILL BE ONGOING THROUGH THE DAY...AND
WITH THE BOUNDARY LAYER ABLE TO MIX SHOULD GET HIGHS IN THE 30S AND
40S FROM CODY TO THEDFORD TO BRADY AND WEST. TO THE EAST...ARCTIC
AIR WILL STILL HAVE AN INFLUENCE...AND WITH CLOUDS REMAINING IN THE
MORNING HOURS...MAY ONLY SEE HIGHS IN THE TEENS AND 20S.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 324 PM CST WED JAN 1 2014
THURSDAY NIGHT THROUGH SATURDAY...THE MAIN FORECAST
CHALLENGES IN THE NEAR TERM ARE TEMPERATURES FRIDAY AND THE THREAT
FOR LIGHT SNOW FRIDAY NIGHT AND SATURDAY IN ASSOCIATION WITH A COLD
FRONT. ARCTIC HIGH PRESSURE WILL DROP SOUTH INTO THE OZARKS THURSDAY
NIGHT...WITH A LEE SIDE TROUGH OF LOW PRESSURE DEEPENING ACROSS THE
HIGH PLAINS OF COLORADO AND WYOMING. SWRLY WINDS WILL DEVELOP
OVERNIGHT...PUSHING A WARM FRONT THROUGH THE FORECAST AREA BY FRIDAY
MORNING. H85 TEMPS BEHIND THE FRONT WILL RANGE FROM 7 TO 10C BY
FRIDAY AFTERNOON. WITH GOOD MIXING EXPECTED FRIDAY AFTERNOON...HIGHS
WILL EASILY REACH THE 40S TO 50S ACROSS THE FORECAST AREA. I DID
LIMIT HIGHS TO THE MID 40S IN THE NORTHWEST AS INCREASED CLOUD COVER
IS EXPECTED FRIDAY AFTERNOON IN ADVANCE OF THE ARCTIC FRONT. WITH
THE ARRIVAL OF THE FRONT FRIDAY NIGHT AND SATURDAY...SOME LOW POPS
WERE INHERITED IN THE ONGOING FCST. THE MODELS CONTINUE TO TREND
DRIER WITH THIS FRONT...ESPECIALLY ACROSS THE SRN CWA...AND HAVE
TAKEN OUT PRECIP CHANCES FRIDAY NIGHT INTO SATURDAY AND LIMITED POPS
TO SLIGHT CHANCES IN THE NORTH. CROSS SECTIONS CONTINUE TO INDICATE
DECENT MID LEVEL MOISTURE WITH THE FRONT...HOWEVER LOW LEVEL
MOISTURE CONTINUES TO LACK WITH THIS FRONT AND DECREASES QUICKLY
FROM NORTH TO SOUTH ACROSS THE FORECAST AREA.
SATURDAY NIGHT THROUGH WEDNESDAY...THE INITIAL SURGE OF ARCTIC AIR
FRIDAY NIGHT AND SATURDAY WILL BE FOLLOWED BY A SECONDARY...MUCH
COLDER SHOT OF ARCTIC AIR SUNDAY NIGHT INTO MONDAY. BOTH THE GFS AND
ECMWF SOLNS THIS MORNING HAVE H85 TEMPS RANGING FROM -20C TO -30C
MONDAY MORNING ALONG WITH GUSTY NORTHWESTERLY WINDS OF 15 TO 30 MPH.
THE COMBINATION OF THE COLD TEMPERATURES AND ARCTIC AIR...WILL
PRODUCE BITTERLY COLD WIND CHILLS SUNDAY NIGHT AND EARLY MONDAY. AT
THIS POINT...DECENT CONFIDENCE EXISTS IN SOME SORT OF WIND CHILL
HEADLINE PRODUCT BEING NEEDED. WITH INCREASED CONFIDENCE...WILL HIT
THIS IN THE HWO AS IT WILL BE SOME OF THE COLDEST AIR OF THE SEASON.
FORTUNATELY...WE SHOULD BE SNOW FREE FOR THE MOST PART...AND WILL
LIMIT LOWS SUNDAY NIGHT TO 5 TO -10 BELOW ZERO. ARCTIC AIR WILL
SHIFT QUICKLY EAST MONDAY NIGHT...WITH TEMPERATURES WARMING BACK TO
THE 20S AND LOWER 30S TUESDAY AND WEDNESDAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING)
ISSUED AT 526 PM CST WED JAN 1 2014
MVFR...WIDESPREAD THIS EVENING...WILL BECOME VFR WEST OF HIGHWAY
83 BETWEEN 06Z-09Z. MVFR IS EXPECTED TO CONTINUE THURSDAY EAST OF
HIGHWAY 83 WITH A GRADUALLY IMPROVEMENT TO VFR FROM WEST TO EAST
THURSDAY AFTERNOON.
THIS THEN PRODUCES UNCERTAIN VFR ARRIVAL TIMES AT KLBF AND KVTN.
SOME MODEL DATA SUCH AS THE RAP MODEL SUGGEST KLBF MAY SCATTERED
OUT THIS EVENING. THE FORECAST FOLLOWS THE MODEL CONSENSUS FOR
CLEARING AT KLBF AROUND 12Z. KVTN CLEARS OUT EARLY AFTN. A
DISTURBANCE...CURRENTLY ACROSS NERN MT...WILL DROP THROUGH KVTN
OVERNIGHT AND PRODUCE SOME LIGHT SNOW.
&&
.LBF WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...CLB
SHORT TERM...BROOKS
LONG TERM...CLB
AVIATION...CDC
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1159 AM CST TUE DEC 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 513 AM CST TUE DEC 31 2013
UPPER AIR DATA CONTINUES TO SHOW THE REGION UNDER THE INFLUENCE
OF NORTHWESTERLY FLOW...WITH LOW PRESSURE CONTINUING TO SPIN OVER
THE HUDSON BAY REGION AND THE MAIN ASSOCIATED TROUGH EXTENDING
SOUTH THROUGH THE MIDWEST TOWARD THE GULF COAST...WHILE HIGH
PRESSURE REMAINS ANCHORED OFF THE SRN COAST OF CA. BEEN A QUIET
NIGHT WITH NO NOTABLE DISTURBANCES MOVING THROUGH...AND OUTSIDE OF
A BIT OF CIRRUS SLIDING IN FROM THE NORTHWEST ASSOCIATED WITH AN
UPPER LEVEL STREAK TO THE N/NE OF THE CWA...SKIES ARE MOSTLY
CLEAR. AT THE SURFACE...HIGH PRESSURE CONTINUES TO GRADUALLY SLIDE
OFF TO THE EAST...BUT WINDS FOR MUCH OF THE CWA REMAIN ON THE
LIGHT AND VARIABLE SIDE. WITH TIME...WINDS WILL BECOME MORE
SOUTHERLY AS THE CWA COMES UNDER MORE INFLUENCE OF LOW PRESSURE TO
THE WEST.
LOOKING TO THE REST OF TODAY...THE FORECAST REMAINS A DRY
ONE...WITH A SWITCH IN WINDS EXPECTED AND ABOVE AVERAGE HIGHS FOR
MOST LOCATIONS. SOUTHERLY WINDS ARE EXPECTED TO REMAIN THROUGH
MOST OF THE MORNING HOURS...BUT AN FRONTAL BOUNDARY APPROACHING
FROM THE WEST WILL BRING A GRADUAL SWITCH TO THE WEST. THIS FRONT
WILL CONTINUE TO MAKE ITS WAY THROUGH THE CWA DURING THE AFTERNOON
HOURS...AND BY 00Z THIS EVENING...MODELS ARE IN PRETTY GOOD
AGREEMENT SHOWING THE FRONT IN THE VICINITY OF THE NEB/KS STATE
LINE...USHERING IN N/NERLY WINDS. MAIN UNCERTAINTY FOR TODAY LIES
WITH HIGH TEMPERATURES. THE RAP DIDNT DO TOO BAD YESTERDAY AND
HAVE TEMPS TODAY AGAIN TRENDED THAT WAY...WHICH IS WARMER THAN
OTHER MODELS/GUIDANCE...BUT THIS FRONT REALLY DOESNT HAVE A COOLER
AIR PUSH WITH IT...AND INCREASED MIXING AHEAD/ALONG THE FRONT
LOOKS TO BRING 40S/50S AGAIN TO MOST OF THE CWA. GOING WITH
STRAIGHT RAP/HRRR WOULD SUGGEST FORECAST HIGHS ARE NOT HIGH ENOUGH
FOR SOME...BUT AM CONCERNED ABOUT THE AMOUNT OF UPPER LEVEL CLOUD
COVER THAT LOOKS TO AFFECT THE CWA FOR AT LEAST THE FIRST HALF OF
THE DAY. TEMP/CLOUD TRENDS WILL BE THE MAIN THING FOR THE DAY
SHIFT TO MONITOR FOR TODAY.
AS WE GET INTO THIS EVENING/OVERNIGHT...PRECIPITATION CHANCES MAKE
A RETURN. ANOTHER UPPER LEVEL SHORTWAVE DISTURBANCE WILL STARTING
MAKING ITS WAY SOUTHEAST OUT OF THE NRN ROCKIES OVERNIGHT...BUT BY
12Z WEDNESDAY THE BULK IS STILL JUST OFF TO THE NW OF THE CWA.
EXPECTING DRY CONDITIONS THROUGH AT LEAST MIDNIGHT...IT MAY EVEN
BE A FEW HOURS BEYOND THAT BEFORE SNOW CHANCES BEGIN MOVING INTO
NRN PORTIONS OF THE CWA. THROUGH THE EARLY MORNING HOURS...KEPT
ANY POPS CONFINED TO LOCATIONS NORTH OF HIGHWAY 6...WITH 40-50
POPS ALONG/NORTH OF HIGHWAY 92. SOME ACCUMULATION WILL BE
POSSIBLE...POTENTIALLY NEAR A HALF INCH THOSE FAR NRN LOCATIONS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 513 AM CST TUE DEC 31 2013
THE BIGGEST CONCERN WILL BE DETERMINING TIMING OF SNOW FOR
WEDNESDAY.
WE BEGIN THE LONG TERM ON WEDNESDAY AS A LOW-AMPLITUDE SHORTWAVE
TROUGH MOVES IN WITHIN NORTHWEST FLOW AND BEGINS TO DEEPEN OVER
OUR AREA AND CONTINUE TO DO SO AS IT TRAVERSES EAST. THIS WILL BE
A QUICK HITTER...AND MODEL SOLUTIONS GENERALLY AGREE THAT THE AXIS
OF THIS WAVE IS TRENDING A SOONER DEPARTURE. THIS QUICK HIT MEANS
THAT SNOW AMOUNTS WILL NOT AMOUNT TO MUCH AND I HAVE KEPT TOTAL
SNOW ACCUMULATIONS LESS THAN 2 INCHES AS THE PREVIOUS FORECAST
DID...WITH THE HIGHER AMOUNTS NORTH/NORTHEAST. MODELS/ENSEMBLES
SUCH AS NAM...SREF...AND NMM WRF INDICATE THAT THERE COULD BE SOME
LINGERING FLURRIES IN THE EVENING. ENSEMBLES CONTINUE TO TREND
COLDER FOR HIGHS AND I HAVE LOWERED THEM FROM PREVIOUS
FORECASTS...STRUGGLING TO GET INTO THE TEENS TO LOWER 20S FOR THE
MOST PART. WITH THE QUICKER DEPARTURE OF THE WAVE...I BACKED OFF
WIND SPEEDS. MILDER WEATHER WILL TRY TO RETURN BY FRIDAY WITH A
QUICK MOVING RIDGE...BUT ANOTHER SHOT OF MUCH COLDER AIR IS ON ITS
WAY FOR THE WEEKEND...REINFORCED EVEN FURTHER BY A MUCH COLDER
ARCTIC AIR MASS. HIGHS ON MONDAY MAY NOT MAKE IT OUT OF THE SINGLE
DIGITS...AND WITH SUCH STRONG COLD AIR ADVECTION...WIND SPEEDS
SHOULD BE STRONGER. THIS COULD SET US UP FOR WIND CHILLS LOW
ENOUGH TO MENTION IN THE HWO FOR MONDAY. WITH THE REINFORCING SHOT
OF VERY COLD AIR WILL LIKELY COME SOME STRATUS AND PERHAPS SOME
LIGHT SNOW. IT DOES NOT APPEAR THAT THIS WOULD BE A SCENARIO THAT
WOULD GIVE US SERIOUS SNOW ACCUMULATIONS.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z WEDNESDAY
AFTERNOON) ISSUED AT 1150 AM CST TUE DEC 31 2013
VFR CONDITIONS WILL CONTINUE THROUGH THE AFTERNOON HOURS AS MOSTLY
CLEAR SKIES ARE EVIDENT IN SATELLITE IMAGERY UPSTREAM OF THE
TERMINAL. EXPECT THE ANTICIPATED COLD FRONT TO REACH THE TERMINAL
AROUND OR JUST BEFORE 01/00Z...WITH WINDS SHIFTING AND BECOMING
NORTHERLY AS A RESULT. OVERNIGHT...EXPECT CIGS TO EVENTUALLY LOWER
AND FOR MVFR CIGS TO DEVELOP...ALONG WITH SOME LIGHT SNOW...AFT
01/12Z. COULD ALSO SEE SOME MVFR VSBYS AFT 01/12Z...BUT KEPT OUT
OF THE TAF FOR THE TIME BEING UNTIL TIMING OF SNOW BANDS BECOMES
A BIT MORE CERTAIN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADO
LONG TERM...HEINLEIN
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS HASTINGS NE
520 AM CST TUE DEC 31 2013
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 513 AM CST TUE DEC 31 2013
UPPER AIR DATA CONTINUES TO SHOW THE REGION UNDER THE INFLUENCE
OF NORTHWESTERLY FLOW...WITH LOW PRESSURE CONTINUING TO SPIN OVER
THE HUDSON BAY REGION AND THE MAIN ASSOCIATED TROUGH EXTENDING
SOUTH THROUGH THE MIDWEST TOWARD THE GULF COAST...WHILE HIGH
PRESSURE REMAINS ANCHORED OFF THE SRN COAST OF CA. BEEN A QUIET
NIGHT WITH NO NOTABLE DISTURBANCES MOVING THROUGH...AND OUTSIDE OF
A BIT OF CIRRUS SLIDING IN FROM THE NORTHWEST ASSOCIATED WITH AN
UPPER LEVEL STREAK TO THE N/NE OF THE CWA...SKIES ARE MOSTLY
CLEAR. AT THE SURFACE...HIGH PRESSURE CONTINUES TO GRADUALLY SLIDE
OFF TO THE EAST...BUT WINDS FOR MUCH OF THE CWA REMAIN ON THE
LIGHT AND VARIABLE SIDE. WITH TIME...WINDS WILL BECOME MORE
SOUTHERLY AS THE CWA COMES UNDER MORE INFLUENCE OF LOW PRESSURE TO
THE WEST.
LOOKING TO THE REST OF TODAY...THE FORECAST REMAINS A DRY
ONE...WITH A SWITCH IN WINDS EXPECTED AND ABOVE AVERAGE HIGHS FOR
MOST LOCATIONS. SOUTHERLY WINDS ARE EXPECTED TO REMAIN THROUGH
MOST OF THE MORNING HOURS...BUT AN FRONTAL BOUNDARY APPROACHING
FROM THE WEST WILL BRING A GRADUAL SWITCH TO THE WEST. THIS FRONT
WILL CONTINUE TO MAKE ITS WAY THROUGH THE CWA DURING THE AFTERNOON
HOURS...AND BY 00Z THIS EVENING...MODELS ARE IN PRETTY GOOD
AGREEMENT SHOWING THE FRONT IN THE VICINITY OF THE NEB/KS STATE
LINE...USHERING IN N/NERLY WINDS. MAIN UNCERTAINTY FOR TODAY LIES
WITH HIGH TEMPERATURES. THE RAP DIDNT DO TOO BAD YESTERDAY AND
HAVE TEMPS TODAY AGAIN TRENDED THAT WAY...WHICH IS WARMER THAN
OTHER MODELS/GUIDANCE...BUT THIS FRONT REALLY DOESNT HAVE A COOLER
AIR PUSH WITH IT...AND INCREASED MIXING AHEAD/ALONG THE FRONT
LOOKS TO BRING 40S/50S AGAIN TO MOST OF THE CWA. GOING WITH
STRAIGHT RAP/HRRR WOULD SUGGEST FORECAST HIGHS ARE NOT HIGH ENOUGH
FOR SOME...BUT AM CONCERNED ABOUT THE AMOUNT OF UPPER LEVEL CLOUD
COVER THAT LOOKS TO AFFECT THE CWA FOR AT LEAST THE FIRST HALF OF
THE DAY. TEMP/CLOUD TRENDS WILL BE THE MAIN THING FOR THE DAY
SHIFT TO MONITOR FOR TODAY.
AS WE GET INTO THIS EVENING/OVERNIGHT...PRECIPITATION CHANCES MAKE
A RETURN. ANOTHER UPPER LEVEL SHORTWAVE DISTURBANCE WILL STARTING
MAKING ITS WAY SOUTHEAST OUT OF THE NRN ROCKIES OVERNIGHT...BUT BY
12Z WEDNESDAY THE BULK IS STILL JUST OFF TO THE NW OF THE CWA.
EXPECTING DRY CONDITIONS THROUGH AT LEAST MIDNIGHT...IT MAY EVEN
BE A FEW HOURS BEYOND THAT BEFORE SNOW CHANCES BEGIN MOVING INTO
NRN PORTIONS OF THE CWA. THROUGH THE EARLY MORNING HOURS...KEPT
ANY POPS CONFINED TO LOCATIONS NORTH OF HIGHWAY 6...WITH 40-50
POPS ALONG/NORTH OF HIGHWAY 92. SOME ACCUMULATION WILL BE
POSSIBLE...POTENTIALLY NEAR A HALF INCH THOSE FAR NRN LOCATIONS.
.LONG TERM...(WEDNESDAY THROUGH MONDAY)
ISSUED AT 513 AM CST TUE DEC 31 2013
THE BIGGEST CONCERN WILL BE DETERMINING TIMING OF SNOW FOR
WEDNESDAY.
WE BEGIN THE LONG TERM ON WEDNESDAY AS A LOW-AMPLITUDE SHORTWAVE
TROUGH MOVES IN WITHIN NORTHWEST FLOW AND BEGINS TO DEEPEN OVER
OUR AREA AND CONTINUE TO DO SO AS IT TRAVERSES EAST. THIS WILL BE
A QUICK HITTER...AND MODEL SOLUTIONS GENERALLY AGREE THAT THE AXIS
OF THIS WAVE IS TRENDING A SOONER DEPARTURE. THIS QUICK HIT MEANS
THAT SNOW AMOUNTS WILL NOT AMOUNT TO MUCH AND I HAVE KEPT TOTAL
SNOW ACCUMULATIONS LESS THAN 2 INCHES AS THE PREVIOUS FORECAST
DID...WITH THE HIGHER AMOUNTS NORTH/NORTHEAST. MODELS/ENSEMBLES
SUCH AS NAM...SREF...AND NMM WRF INDICATE THAT THERE COULD BE SOME
LINGERING FLURRIES IN THE EVENING. ENSEMBLES CONTINUE TO TREND
COLDER FOR HIGHS AND I HAVE LOWERED THEM FROM PREVIOUS
FORECASTS...STRUGGLING TO GET INTO THE TEENS TO LOWER 20S FOR THE
MOST PART. WITH THE QUICKER DEPARTURE OF THE WAVE...I BACKED OFF
WIND SPEEDS. MILDER WEATHER WILL TRY TO RETURN BY FRIDAY WITH A
QUICK MOVING RIDGE...BUT ANOTHER SHOT OF MUCH COLDER AIR IS ON ITS
WAY FOR THE WEEKEND...REINFORCED EVEN FURTHER BY A MUCH COLDER
ARCTIC AIR MASS. HIGHS ON MONDAY MAY NOT MAKE IT OUT OF THE SINGLE
DIGITS...AND WITH SUCH STRONG COLD AIR ADVECTION...WIND SPEEDS
SHOULD BE STRONGER. THIS COULD SET US UP FOR WIND CHILLS LOW
ENOUGH TO MENTION IN THE HWO FOR MONDAY. WITH THE REINFORCING SHOT
OF VERY COLD AIR WILL LIKELY COME SOME STRATUS AND PERHAPS SOME
LIGHT SNOW. IT DOES NOT APPEAR THAT THIS WOULD BE A SCENARIO THAT
WOULD GIVE US SERIOUS SNOW ACCUMULATIONS.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z WEDNESDAY MORNING)
ISSUED AT 513 AM CST TUE DEC 31 2013
MAIN FORECAST CONCERNS FOR THIS TAF PERIOD LIE WITH CHANGING WIND
DIRECTION THROUGH THE DAY...THEN PRECIP CHANCES LATE IN THE
PERIOD. THE DAY WILL START OUT WITH SOUTHERLY WINDS...BUT ANOTHER
SURFACE FRONTAL BOUNDARY IS EXPECTED TO PUSH THROUGH THE
REGION...BRINGING MORE OF A WESTERLY COMPONENT THROUGH THE
MID/LATE MORNING HOURS...WITH THE AFTERNOON BECOMING MORE
NORTHERLY WITH TIME. SPEEDS ARE EXPECTED TO TOP OUT BETWEEN 10 AND
15 MPH OUT AHEAD OF THE FRONT. AT THIS TIME KEPT CONDITIONS VFR
THROUGH THE PERIOD...BUT CONFIDENCE IN THAT FOR THE LAST FEW HOURS
OF THIS PERIOD IS ON THE LOW SIDE...AS AN UPPER LEVEL DISTURBANCE
BEGINS TO SLIDE INTO THE REGION. THE CHANCE FOR SOME LIGHT SNOW
HAS BEEN ADDED...AND ITS POSSIBLE UPCOMING TAF FORECASTS MAY NEED
TO LOWER CEILINGS.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADO
LONG TERM...HEINLEIN
AVIATION...ADO
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1252 AM EST TUE DEC 31 2013
.SYNOPSIS...
HIGH PRESSURE WILL BRING PARTLY CLOUDY SKIES AND COLD TEMPERATURES
TO THE REGION TONIGHT. WEAK LOW PRESSURE TRACKING ACROSS LOWER
ONTARIO WILL BRING SOME LIGHT SNOW TO THE AREA ON TUESDAY...WITH
LAKE EFFECT SNOWS DEVELOPING BEHIND THIS SYSTEM FOR TUESDAY NIGHT
AND WEDNESDAY MORNING. MORE WIDESPREAD SNOW IS EXPECTED TO DEVELOP
ON WEDNESDAY NIGHT AND THURSDAY...WITH THE POTENTIAL FOR MODERATE
ACCUMULATIONS.
&&
.NEAR TERM /THROUGH TODAY/...
LAKE EFFECT MOISTURE CONTS TO LINGER IN THE CENTRAL SOUTHERN TIER
OF NY AND NC PA. THERE LOOKS LIKE THERE WAS EVEN FINGER LAKES
MOISTURE GETTING DRAWN IN AS WELL. CONTINUING SUBSC AND WEAKENING
WINDS OVERNIGHT SHUD CUT OFF ALL THE LAKE EFFECT FLURRIES. BY 6Z
THE LATEST RAP MODEL HAS 925 MB WINDS GOING CALM SO HAVE FLURRIES
ENDING AT THIS TIME. OTHERWISE CLOUDS WILL STREAM IN OVERHEAD AS
UVV INCREASES AHEAD OF NEXT SMALL CLIPPER SYSTEM. ALL SYNOPTIC
MODELS SHOW THIS SYSTEM WORKING ACRS NY AND PA TUESDAY DURING THE
DAY. THE MAIN DYNAMICAL FEATURE ASSCTD WITH THIS WAVE WAS JET
STREAK WHICH WAS DROPPING INTO THE BASE OF THE UPPER TROF OVER THE
ERN LAKES BY 18Z TUE. NRN PA AND C NY ARE IN THE LEFT FRONT QUAD
OF THIS UPPER LEVEL JET AND THERE WAS SIGNIFICANT LIFTG.
HOWEVER...TYPICAL OF NRN BRANCH WAVES THERE WAS LITTLE MOISTURE.
SO NOT LOOKING AT MUCH SNOW ACC/S...MAYBE AN INCH AT BEST. MODELS
AGREE THAT LIGHT SNOW ARRIVES FROM W TO E BWTN 10 AND 13Z AND
EXITS IN THE AFTERNOON. AFTER THIS WAVE PASSES BY A COLD STRONG
WESTERLY FLOW OF AIR SETS UP IN THE LOW-LEVELS TRIGGERING MORE
LAKE EFFECT SNOWS. H85 TEMPS DROP TO -18C OR SO WITH DECENT
INSTABILITY. KEPT LES WATCH GOING FOR NRN ONEIDA CO AS EXACT PLACEMENT
OF THE LAKE ONTARIO SNOWBAND STILL IS UNCERTAIN. IN ADDTN...925 MB
AND 850 MB WINDS ARE QUITE STRG RUNNING OVER 30 KNOTS...MESOSCALE
AND EVEN SYNOPTIC MODELS ARE HINTING AT A LAKE ERIE BAND THAT CUD
EXTEND WELL INLAND ACRS THE SRN TIER OF NY AND INTO NE PA. I HAVE
CHC POPS FOR SNOW SHOWERS IN THESE AREAS TO COVER THIS BEGINNING
TUE PM.
&&
.SHORT TERM /TONIGHT THROUGH THURSDAY/...
LES BAND SHUD BE GOING STRONG TMRW EVNG ACRS NRN SXNS OF THE FCST
AREA. PROFILES ARE PRETTY IMPRSV WITH HIGH INVERSION LVL AND GOOD
SIGS FOR SNOW GROWTH. UNCERTAINTY AS TO HOW FAR SOUTH THIS BAND
WILL GET...WITH SOME MDLS KEEPING ACTIVITY OVER FAR NRN ZONES OF
THE BGM CWA...WHILE OTHERS DROP THE BAND SEWD INTO ONON/MAD/SRN
ONEIDA. FOR NOW ISSUED THE LES WATCH FOR NRN ONEIDA WHERE OUR
CONFIDENCE IS GREATEST...AND MENTIONED THE POTENTIAL (IF THE BAND
DROPS SOUTH) IN THE HWO FOR THE AFOREMENTIONED COUNTIES.
OPERATIONAL MDLS ARE TRENDING SLOWER AND DEEPER WITH THE UPR LVL
TROF DIGGING INTO THE ERN U.S. ON THURSDAY...AND ISENTROPIC LIFT
DVLPNG N OF THE ARCTIC FNTL BNDRY. STRONG HIGH PRES OVER QUEBEC
WILL KEEP THE COLD AIR LOCKED IN PLACE. A RATHER PROLONGED PD OF
SNOW LOOKS LIKELY TO BEGIN ON WED AND CONTINUE INTO THU...PRBLY INCRSNG
IN INTENSITY ON THU. NICE SIGS IN THE QVEC AND FGEN FIELDS...WITH
PROFILES LOOKING GOOD FOR SNOW GROWTH. SNOW RATIOS SHUD ALSO BE
RATHER HIGH GIVEN THE COLD AIR MASS. AT THIS POINT WILL CONTINUE
TO MENTION POTNL IN THE HWO.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
3 PM MON UPDATE... SYNOPTIC SNOWFALL EVENT SHOULD BE ONGOING THU
NGT...PERHAPS LINGERING INTO FRI. THERE ARE STILL PLENTY OF MODEL
DISCREPANCIES WITH THIS STORM...AS THE 12Z EC REMAINS THE MOST
AMPLIFIED AND SLOWEST WITH THE MAIN UPPER-LVL TROUGH AXIS...WHILE
THE GFS/CAN GEM ARE MORE PROGRESSIVE. ATTM...WPC IS LEANING TWDS
THE MORE PROGRESSIVE SOLNS...GIVEN THE PROGGED CANADIAN MARITIME
UPPER-LVL LOW...AND THE CONFLUENT PATN UNDERNEATH IT...WHICH SEEMS
REASONABLE AT THIS EARLY VANTAGE PT. EVEN SO...NICE WAA/FGEN FORCING
INTO THU NGT...FOLLOWED BY BRIEF DEFORMATION BAND MECHANICS INTO
EARLY FRI...LIKELY TRANSLATES TO AT LEAST WIDESPREAD ADVSY LVL
SNOW ACCUMS. STAY TUNED...AS MANY DETAILS ARE YET BE IRONED OUT.
THE OTHER MAIN STORY THIS PD IS THE ARCTIC AMS EXPECTED TO PLUNGE
SWD INTO CNY/NE PA FRI INTO SAT. IF ANYTHING...THE MODELS HAVE
TRENDED EVEN COLDER IN RECENT RUNS...WITH BOTH THE GFS/EC SHOWING
TEMPS NOT MUCH ABV ZERO FRI...THEN WELL BLO ZERO FRI NGT/EARLY
SAT. WE`VE BEEN ADVERTISING SINGLE DIGIT HIGHS ON FRI...WITH WELL
BLO ZERO READINGS FRI NGT/SAT MRNG...SO WE DIDN`T MAKE MANY CHGS
HERE. WE DID NUDGE TEMPS LWR LTR IN THE WEEKEND INTO EARLY NEXT
WEEK...TO BETTER MATCH THE LATEST STATISTICAL GUIDANCE.
MAINLY DRY WX IS STILL FORESEEN AT THE BEGINNING OF THE
WEEKEND...WHEN THE DEEPEST COLD WILL LIKELY BE IN PLACE. FROM SUN
INTO EARLY NEXT WEEK...ADDITIONAL NRN STREAM SHRT WV/FRNTL
PASSAGES ARE LIKELY...SO WE`VE JUST GONE WITH A GENERIC CHC OF
SHSN/FLRYS FOR NOW. AS WE DRAW CLOSER IN TIME...HOPEFULLY WE`LL
GET A BETTER FEEL FOR WHERE THE MOST PERSISTENT LES BANDS MAY SET
UP.
&&
.AVIATION /06Z TUESDAY THROUGH SATURDAY/...
06Z UPDATE...
CLOUDY SKIES WILL PERSIST THROUGH THIS MORNING WITH MOSTLY VFR
CIGS FROM 3-5 KFT. MVFR TO VFR CIGS WILL CONTINUE THROUGH TUESDAY
AFTERNOON WITH SNOW SHOWERS DEVELOPING. A FEW HEAVIER SNOW
SHOWERS WILL BRIEFLY LOWER CONDITIONS TO IFR BETWEEN 18Z AND 22Z.
LAKE EFFECT SNOW WILL DEVELOP NEAR AND NORTH OF THE THRUWAY LATE
TUESDAY AFTERNOON AND TUESDAY EVENING POSSIBLY BRINGING SOME HEAVY
SNOW TO THE RME TAF SITE... OTHERWISE THIS SNOW WILL REMAIN NORTH
OF THE REST OF THE TAF SITES THROUGH TUESDAY NIGHT.
WINDS WILL BE LIGHT AND VARIABLE EARLY THIS MORNING... THE WEST-
SOUTHWEST AT 10 TO 15 KTS WITH GUSTS TO 20 KTS THIS AFTERNOON INTO
THIS EVENING. WEST WINDS WILL CONTINUE AROUND 10 KTS LATE TUESDAY
NIGHT.
OUTLOOK...
WED...MVFR/IFR SHSN IN KSYR/KRME...WITH MAINLY VFR ELSEWHERE.
WED NGT-THU NGT...IFR SNOW LIKELY AREA-WIDE.
FRI...LINGERING RESTRICTIONS PSBL IN SHSN.
FRI NGT/SAT...MAINLY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...LAKE EFFECT SNOW WATCH FROM THIS AFTERNOON THROUGH WEDNESDAY
MORNING FOR NYZ009.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...
LONG TERM...MLJ
AVIATION...MSE/PVN
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
637 PM EST WED JAN 1 2014
.SYNOPSIS...
A MOIST SOUTHWEST FLOW WILL BRING RAINFALL TO THE REGION TONIGHT
THROUGH THURSDAY. MUCH COLDER AND DRIER CONDITIONS WILL DEVELOP
FRIDAY AND PERSIST INTO THE WEEKEND. TEMPERATURES MAY SLOWLY
MODERATE NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM WEDNESDAY...THIS NEAR-TERM UPDATED FOCUSES ON
TEMPERATURES AND COASTAL WATERS WINDS. 6 PM OBSERVATIONS SHOWED
TEMPERATURES ALREADY AT OR BELOW FORECAST LOWS...THEREFORE I HAVE
LOWERED FORECASTS UP TO 6 DEGREES IN SPOTS WITH LOWER 40S NOW
EXPECTED MOST AREAS. LIGHT RAIN ALONG THE COAST IS CREATING
EVAPORATIONAL COOLING...BUT THIS DIABATIC PROCESS SHOULD END SHORTLY
AS TEMPERATURES AND DEWPOINTS CONVERGE TOGETHER. FARTHER INLAND
DEWPOINTS ARE STILL IN THE UPPER 30S AND WE SHOULD SEE TEMPERATURES
FALL THERE AS WELL WHEN BETTER PRECIPITATION DEVELOPS AFTER
MIDNIGHT. HOURLY RAIN CHANCES HAVE BEEN ADJUSTED SLIGHTLY AS WELL TO
REFLECT TRENDS IN THE LATEST FEW HRRR RUNS OF CURRENTLY OBSERVED
PRECIPITATION WANING OVER THE NEXT FEW HOURS...BUT THEN REDEVELOPING
EVEN WEST OF THE I-95 CORRIDOR AFTER 2-3 AM THURSDAY MORNING WITH A
RENEWED SHOT OF ISENTROPIC LIFT ALONG THE 300-305K THETA SURFACES.
PREVIOUS DISCUSSION FROM 230 PM FOLLOWS...
A DEEPENING UPPER LEVEL TROUGH WILL BOTTOM OUT ACROSS THE SOUTHEAST
ON THU AND THEN LIFT OUT ACROSS THE REGION THROUGH FRI MORNING. A
COASTAL TROUGH WILL CONTINUE TO SLOWLY SHARPEN AS IT DEVELOPS
NORTHWARD THROUGH THIS EVE. LOW PRESSURE IS EXPECTED TO DEVELOP
ALONG THIS BOUNDARY...ABOUT 150 MILES SSE OF THE MOUTH OF THE CAPE
FEAR RIVER OVERNIGHT.
RADAR ECHOES CONTINUED TO STREAK ACROSS THE FORECAST AREA AND
ESPECIALLY TO OUR S AND OFFSHORE. WEAKENING HIGH PRESSURE WAS
CENTERED OFF THE MID ATLANTIC COAST AND ITS RESIDUAL DRY AIR WAS
STILL ONLY ALLOWING FOR SPRINKLES AT MID AFTERNOON. HOWEVER...AS
ISENTROPIC UPGLIDE STRENGTHENS AND HIGH PRESSURE RETREATS...MORE AND
MORE OF THE PRECIPITATION SHOULD REACH THE GROUND THROUGH THIS EVE
AS THE COLUMN BEGINS TO SATURATE IN THE LOW-LEVELS.
RICH GULF OF MEXICO MOISTURE WILL BE TAPPED AHEAD OF THE UPSTREAM
TROUGH. PRECIPITABLE WATER VALUES WILL CLIMB TO JUST UNDER AN INCH
AND A HALF AT THE COAST AND TO AROUND AN INCH FURTHEST INLAND AS A
DEEP AND STRENGTHENING SW FLOW ENVELOPS THE EASTERN CAROLINAS.
ISENTROPIC LIFT AND THE EVENTUAL ARRIVAL OF UPPER LEVEL FORCING WILL
ALLOW FOR A SIGNIFICANT STRATIFORM RAIN EVENT. THE BEST MOISTURE
FEED AND THUS THE DEEPEST AND MOST PROLONGED PERIOD OF COLUMNAR
SATURATION IS EXPECTED ALONG THE COAST WHERE QPF AMOUNTS MAY REACH
AROUND AN INCH AND A QUARTER TONIGHT THROUGH THU. RAINFALL AMOUNTS
ARE EXPECTED TO DROP OFF AS YOU MOVE PROGRESSIVELY INLAND...TO
AROUND A THIRD OF AN INCH W OF INTERSTATE 95.
TEMPS WILL NOT DROP OFF MUCH OVERNIGHT...JUST A HANDFUL OF DEGREES.
WE ARE EXPECTING LOWS IN THE UPPER 40S TO LOWER 50S WITH MID 40S
ALONG AND W OF INTERSTATE 95. THE PRECIPITATION WILL REMAIN ALL
LIQUID THROUGH THE EVENT.
&&
.SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...SIGNIFICANT RAIN EVENT WILL BE WELL UNDERWAY
AT THE BEGINNING OF THE PERIOD AS THE MID LEVEL TROUGH MOVING
THROUGH THE CENTRAL U.S. WORKS IN TANDEM WITH THE EXTENSIVE
ATMOSPHERIC RIVER FROM THE SUB TROPICAL JET STREAM. THE 1200 UTC
MODEL CYCLES HAVE BACKED OFF FORCING EVER SO SLIGHTLY WITH THE
RESULT BEING QPF AMOUNTS A LITTLE LESS BUT STILL EXPECT ALL AREAS
TO RECEIVE RAINFALL AND I HAVE RAISED POPS TO 100 ACROSS THE BOARD
FOR THURSDAY. THE FOCUS THEN TRANSITIONS TO THE COLD AIR WORKING
IN BEHIND THE SYSTEM.
THE 850MB TEMPERATURES FROM THE OPERATIONAL GFS ARE NOT THE COLDEST
I HAVE SEEN...MINUS 4-5 DEGREES C FOR FRIDAY SO THEREFORE A LITTLE
INCREASE THROUGHOUT THE DAY FRIDAY IS ANTICIPATED AND MOST AREAS
SHOULD ECLIPSE THE 40 DEGREE THRESHOLD. FOR SATURDAY MORNING
LOWS...GUIDANCE IS STILL IN GOOD AGREEMENT WITH IDEAL RADIATIONAL
CONDITIONS AND LOWER 20S ACROSS THE BOARD. SEE NO REASON TO DEVIATE
FROM THESE NUMBERS SO A VERY COLD MORNING SEEMS TO BE IN STORE.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
AS OF 230 PM WEDNESDAY...CHILLY AIRMASS LOSING ITS GRIP ON THE
REGION ON SATURDAY BUT STILL ENOUGH TO KEEP HIGHS BELOW CLIMO. AS
THE MAIN HIGH SHIFTS WELL OFFSHORE AND A COASTAL TROUGH DEVELOPS LOW
LEVEL ATLANTIC MOISTURE PAIRED WITH WARM ADVECTION TO BRING PLENTY
OF CLOUD AND PERHAPS A FEW SPRINKLES. THE HIGH QUICKLY BREAKS DOWN
BY SUNDAY AND A PREFRONTAL SOUTHWESTERLY FLOW WILL ALLOW THE
AFTERNOON TO WARM NICELY INTO THE 60S. NEXT FRONT LOOKS A LITTLE
FASTER AND MAY ARRIVE SUNDAY NIGHT. WITH ONLY A BRIEF PERIOD OF DEEP
MOISTURE FLUX AHEAD OF THE BOUNDARY RAINFALL CHANCES/AMOUNTS NOT
LOOKING SO HOT. THE UPPER SYSTEM DRIVING THIS BOUNDARY WILL BE A
DEEP GREAT LAKES VORTEX CHARACTERISTIC OF U.S. ARCTIC INTRUSIONS.
TROUBLE IS MODELS HAVING TROUBLE RESOLVING THE DEPTH AND LATITUDE OF
THE SYSTEM. THIS WILL DICTATE HOW DEEP INTO THE TRULY COLD AIR WE
GET. GFS HAS BACKED OFF ON THE MAGNITUDE OF THE COLD AND SO TEMPS
LATE IN THE PERIOD MAY NEED TO BE RAISED SLIGHTLY. THE ECWMF STILL
HAS SOME IMPRESSIVE COLD BY TUESDAY HOWEVER SO NO REAL CHANGES WILL
BE MADE AT THIS TIME.
&&
.AVIATION /00Z THURSDAY THROUGH MONDAY/...
AS OF 00Z...LOW VFR CIGS HAVE DEVELOPED ACROSS THE TERMINALS THIS
EVENING. RADAR INDICATES RAINFALL OCCURRING MAINLY AT THE COASTAL
TERMINALS WITH SPRINKLES AT KFLO/KLBT.
RAINFALL WILL GRADUALLY INCREASE AND SPREAD SOUTH TO NORTH THIS TAF
VALID PERIOD AS AN APPROACHING UPPER TROUGH INCREASES MOIST
ISENTROPIC LIFT. A SERIES OF SURFACE LOWS WILL ALSO MOVE NE JUST
OFFSHORE THURSDAY. CONFIDENCE IS MODERATE TO HIGH FLIGHT CONDITIONS
WILL GRADUALLY DETERIORATE TO IFR/LIFR AFTER MIDNIGHT...BEGINNING AT
THE COASTAL SITES WHERE MORE PERSISTENT RAINFALL IS EXPECTED.
CONFIDENCE IN TIMING IS LOW HOWEVER. THE GFS/NAM GUIDANCE ARE IN
GENERAL AGREEMENT FOR THE COASTAL TERMINALS...BUT DIFFER IN THE
AMOUNT AND TIMING OF IFR AT KLBT/KFLO...THUS CONFIDENCE IS LOWEST
FOR THESE SITES. IFR/LIFR CIGS WILL LIKELY PERSIST THROUGH THE
AFTERNOON HOURS AS RAIN CONTINUES TO FALL...ESPECIALLY ALONG THE
COASTAL TERMINALS.
EXTENDED OUTLOOK...VFR FRIDAY. MVFR CIGS POSSIBLE ON SATURDAY.
SLIGHT CHANCE OF RAIN ON SUNDAY AND MONDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 PM WEDNESDAY...THE COASTAL TROUGH IS WEST OF THE FRYING
PAN SHOALS BUOY WHERE SOUTHERLY WINDS AND MID 60S AIR TEMPERATURES
ARE OBSERVED. WEST OF THE TROUGH WINDS ARE MORE NORTHERLY WITH AIR
TEMPERATURES IN THE UPPER 40S AND 50S. THE TROUGH SHOULD MAKE LITTLE
ADDITIONAL PROGRESS WESTWARD AND SHOULD ACTUALLY RETREAT OFFSHORE
OVERNIGHT AS LOW PRESSURE DEVELOPS OUT TO SEA...DRAGGING THE TROUGH
ALONG WITH IT. THE LATEST FEW RUNS OF THE HRRR MODEL SUGGEST THIS AS
DOES THE 12Z CANADIAN MODEL. THESE ARE THE BASIS FOR THIS NEAR-TERM
UPDATE. PREVIOUS DISCUSSION FROM 230 PM FOLLOWS...
UNTIL LOW PRESSURE DEVELOPS AND THEN DEEPENS...WINDS WILL BE RATHER
LIGHT ACROSS THE WATERS. A COASTAL TROUGH WILL SHARPEN AS IT
DEVELOPS NORTHWARD THROUGH TONIGHT WITH LOW PRESSURE DEVELOPING
ALONG THIS BOUNDARY...ABOUT 150 MILES SSE OF THE MOUTH OF THE CAPE
FEAR RIVER LATE TONIGHT.
EXPECT WINDS OF AROUND 10 KT THROUGH TONIGHT WITH WINDS INCREASING
SHARPLY...LIKELY TO GALE FORCE FOR A TIME THU NIGHT AND FRI MORNING
AS THE PRESSURE GRADIENT SEVERELY TIGHTENS. THE WIND DIRECTION WILL
BE E OR ESE BEFORE SETTLING ON NORTHERLY TONIGHT...LASTLY ACROSS THE
NORTHERN WATERS AS LOW PRESSURE DEVELOPS OFFSHORE AND TO OUR S.
SEAS WILL BEGIN TO BUILD THU...REACHING DANGEROUS LEVELS DURING THU
NIGHT. HOWEVER...THROUGH TONIGHT...SEAS WILL BE 3 FT OR LESS WITH
SOME 4 FT SEAS POSSIBLE BY EARLY THU MORNING. RAIN WILL BECOME
WIDESPREAD TONIGHT...RESTRICTING VISIBILITIES TO 1 NM OR LESS AT
TIMES.
SHORT TERM /THURSDAY THROUGH FRIDAY NIGHT/...
AS OF 230 PM WEDNESDAY...THE BIG STORY WILL BE THE WINDS IN THE WAKE
OF THE SYSTEM THURSDAY. EXPECT ABOUT A 12 HOUR PERIOD OF STRONG COLD
AIR ADVECTION WITH WIND SUSTAINED WIND SPEEDS 25-30 KNOTS. FOR
GUSTS...THERE SHOULD BE NUMEROUS ONES EXCEEDING THE 34 KNOT
THRESHOLD FOR GALES. THEREFORE...I HAVE HOISTED A GALE WARNING FOR
LATE THURSDAY INTO THE DAY FRIDAY.
FOR THURSDAY ESSENTIALLY LIGHT AND VARIABLE WINDS WILL CONTINUE AS
THE RAIN MAKER IS BASICALLY DUE TO MID AND UPPER LEVEL FORCING. FOR
LATER FRIDAY INTO SATURDAY MORNING WIND SPEEDS SHOULD GRADUALLY
DIMINISH FROM THE AFOREMENTIONED 25-30 KNOT SUSTAINED TO 15-20 BY
SATURDAY MORNING. THE LATEST RUN OF SWAN LOOKS GOOD WITH BENIGN SEAS
FOR MOST OF THURSDAY RAMMING UP QUICKLY EARLY FRIDAY WITH THE WINDS
THEN SHIFTING THE HIGHER SEAS OFFSHORE LATER FRIDAY WITH THE FETCH.
LONG TERM /SATURDAY THROUGH MONDAY/...
AS OF 230 PM WEDNESDAY...WEAKENING GRADIENT ON SATURDAY AS HIGH
PRESSURE MOVES WELL OFFSHORE WHILE A COASTAL TROUGH ALSO DEVELOPS.
BOTH WILL ACT TO VEER THE FLOW AND ALLOW SEAS TO SETTLE TO WHERE NO
ADVISORIES OR CAUTIONARY HEADLINES WILL BE NEEDED. THIS VEERING
CONTINUES ON SUNDAY AND A SOUTHERLY COMPONENT DEVELOPS AHEAD OF AN
APPROACHING COLD FRONT. LATER SUNDAY WILL ALSO FEATURE A TIGHTENING
OF THE GRADIENT DUE TO THE APPROACH OF SAID BOUNDARY AND CONDITIONS
MAY FLIRT WITH CAUTIONARY HEADLINES. STRONG FRONTAL VEER SUNDAY
NIGHT WITH A COLD SURGE POSSIBLY GETTING CLOSE TO SMALL CRAFT
ADVISORY.
&&
.TIDES/COASTAL FLOODING...
AS OF 230 PM WEDNESDAY...TIDES WILL SHOW AN UNUSUALLY LARGE RANGE
BETWEEN CREST AND TROUGH OVER THE NEXT FEW DAYS AS HIGH
ASTRONOMICAL TIDES COINCIDE WITH A DEVELOPING AND DEEPENING
COASTAL STORM. THE CAPE FEAR RIVER IN DOWNTOWN WILMINGTON IS
EXPECTED TO BE NEAR COASTAL FLOOD ADVISORY LEVELS THU MORNING.
ALONG THE COAST...WATER LEVELS AROUND THE TIME OF HIGH TIDE WERE
ELEVATED EARLIER THIS MORNING AND WE EXPECT THE WATER LEVELS WILL
REACH SIMILAR LEVELS WITH EACH HIGH TIDE THROUGH THU. WATER LEVELS
WILL BE UNUSUALLY LOW AROUND THE TIME OF LOW TIDE THROUGH THU
NIGHT. A MARINE WEATHER STATEMENT HAS BEEN ISSUED TO ADDRESS THIS
HAZARD TO MARINERS. WATER LEVELS AT LOW TIDE ARE EXPECTED TO BE
NEAR MINUS 1 FT MLLW TO AS LOW AS MINUS 1.75 FT MLLW WITH THE
LOWEST LEVELS LIKELY BEING REALIZED IN OFFSHORE FLOW ON THE BACK
SIDE OF DEEPENING LOW PRESSURE THU NIGHT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...GALE WARNING FROM 1 AM TO 1 PM EST FRIDAY FOR
AMZ250-252-254- 256.
&&
$$
SYNOPSIS...SHK
NEAR TERM...RJD/TRA
SHORT TERM...SHK
LONG TERM...MBB
AVIATION...MRR
TIDES/COASTAL FLOODING...RJD
AREA FORECAST DISCUSSION
NWS PORTLAND OR
746 AM PST TUE DEC 31 2013
.SYNOPSIS...A WEAK COLD FRONT WILL MOVE THROUGH MAINLY THE
NORTHERN PART OF SOUTHWEST WASHINGTON AND NORTHWEST OREGON TUESDAY
FOR MORE AREAS OF LIGHT RAIN. THE UPPER RIDGE WILL BECOME
REESTABLISHED TUESDAY NIGHT AND WEDNESDAY FOR DRYING BUT WITH MORE
AREAS OF FOG AND LOW CLOUDS...WHICH WILL CONTINUE INTO THURSDAY. THE
NEXT STRONGER FRONT WILL SPREAD IN LATER THURSDAY AND THURSDAY NIGHT
FOR A DECENT RAIN. SNOW LEVELS WILL FALL TO NEAR OR BELOW PASS
ELEVATIONS LATE THURSDAY NIGHT AND FRIDAY BUT PRECIPITATION WILL BE
WANING AT THAT POINT...SO ONLY LIGHT SNOW IS EXPECTED IN THE
CASCADES. THE MOST LIKELY SCENARIO FOR THIS WEEKEND AND EARLY NEXT
WEEK IS A RETURN TO THE UPPER RIDGE AND DRY WEATHER.
&&
.QUICK MORNING UPDATE...INCREASED POPS SUBSTANTIALLY IN AN EAST TO
WEST BAND EXTENDING ACROSS THE CWA...WITH ITS NORTHERN BOUNDARY NEAR
VANCOUVER AND SOUTHERN BOUNDARY NEAR SALEM. ISENTROPIC LIFT NEAR
290K AHEAD OF A WEAK FRONT IS LIKELY AIDING IN LIGHT RAIN DEVELOPING
ACROSS THIS REGION. HOWEVER...NO MODEL SEEMS TO HAVE A GREAT HANDLE
ON THE CURRENT PRECIPITATION LAYOUT INCLUDING THE HRRR SO WILL
EXAMINE POPS FURTHER TO SEE IF THEY NEED TO BE ADJUSTED FOR THIS
AFTERNOON AS WELL.
ALSO...CANCELED THE AIR STAGNATION ADVISORY FOR THE PORTLAND METRO
AREA WHERE RAIN SHOULD EASE POLLUTION LEVELS AS A RESULT OF WET
DEPOSITION. THIS COUPLED WITH EASTERLY FLOW COMING OUT OF THE GORGE
WEDNESDAY AND A COMPLETE MIX OUT EXPECTED THURSDAY
AFTERNOON/EVENING...72 HOURS OF STAGNANT CONDITIONS SEEM UNLIKELY TO
BE MET FROM THIS POINT FORWARD. GIVEN THE RAIN IN MCMINNVILLE AND
SALEM...THE CENTRAL VALLEY COULD ARGUABLY BE DROPPED...BUT WILL LET
IT RIDE FOR NOW AND REEVALUATE LATER TODAY. /NEUMAN
.SHORT TERM...TUESDAY THROUGH THURSDAY NIGHT...
WEAK COLD FRONT IS MAKING ITS WAY CLOSER TO SHORE EARLY THIS MORNING
BASED ON SATELLITE OBSERVATIONS. NOTE THAT KLGX (COASTAL WASHINGTON)
RADAR IS DOWN. SATELLITE SHOWS A SEMI ORGANIZED BAND OFF THE S WA
COAST...WITH ADDITIONAL MOISTURE LOCATED JUST ON THE BACK SIDE OF
THE FRONT WELL BACK BEHIND MORE LOOSELY ORGANIZED MOISTURE. HOQUIAM
HAS BEEN SHOWING ON AND OFF LIGHT RAIN TO THIS POINT...BUT NOTHING
THIS FAR SOUTH. THE FRONT IS PROGGED TO MOVE INTO OUR NORTH COASTAL
AREAS LATER THIS MORNING THAN STALL OUT AS A WEAK WAVE IN WNW FLOW
RIDES OVER IT. NOT EXPECTING A WHOLE LOT OF PRECIPITATION...BUT
STILL A BETTER CHANCE THAN YESTERDAY. AREAS FROM ABOUT SALEM
SOUTHWARD PROBABLY WILL NOT SEE MUCH AS HIGHER PRESSURE LIMITS
SOUTHWARD MOVEMENT OF THE FRONT...WHILE AREAS TO THE NORTH HAVE A
MUCH BETTER CHANCE LATER THIS MORNING INTO EARLY AFTERNOON.
MODELS REMAIN IN GOOD AGREEMENT THAT SURFACE HIGH PRESSURE AHEAD F
THE UPPER RIDGE OFFSHORE WILL ALLOW FOR RAPID DRYING TUESDAY NIGHT
AND WEDNESDAY. HOWEVER...THIS WILL MAKE IT MORE CONDUCIVE
TO FORMING MORE FOG AND LOW CLOUDS...WHICH WILL LIKELY NOT CLEAR IN
THE AFTERNOONS. CONTINUE TO UNDERCUT GUIDANCE WHICH HAS BEEN TOO HIGH
FOR THE DURATION OF THIS STAGNANT COOL VALLEY LOW LEVEL AIR MASS. THE
NAM SUGGEST A BIT OF AN OFFSHORE GRADIENT DEVELOPING...SO BEST BET
FOR CLEARING WILL BE NEAR THE GORGE.
THERE AN UPPER LEVEL CIRCULATION CURRENTLY NEAR 38N/143W THAT WILL
MOVE THROUGH THE PACIFIC NORTHWEST WEDNESDAY EVENING. MODELS TO THIS
POINT HAVE WAVERED CONSIDERABLY IN HANDLING THIS WAVE...SOME EARLIER
THIS WEEK SUGGESTING IT WOULD SLIDE SOUTH...WITH THE MODEL CONSENSUS
OF LATE SUGGESTING IT WOULD RIDE NORTH...WHICH MAKES SENSE WITH THE
BUILDING OFFSHORE UPPER RIDGE. 0Z NAM AND ECMWF AND CANADIAN NOW CAME
IN WITH A WAVE THAT EVENTUALLY SKIRTS THROUGH THE NORTHERN TIER OF
OUR AREA AND RIDES OVER THE LINGERING FRONTAL BOUNDARY FOR SOME VERY
LIGHT RAIN ALONG AND NORTH OF THE COLUMBIA RIVER. NOT A VERY HIGH
IMPACT SITUATION...BUT WILL KEEP SOME VERY LOW POPS FOR THESE AREAS
BUT DO NOT EXPECT IT TO AMOUNT TO MUCH WITH SURFACE HIGH PRESSURE IN
PLACE AND A NORTHWARD MOVING WARM FRONT. EVEN THESE AREAS DRY OUT
INTO THURSDAY MORNING.
THERE IS ANOTHER STRONGER FRONT THAT WILL APPROACH THE AREA EARLY
THURSDAY AND MOVE INTO SOUTHWEST WASHINGTON AND NORTHWEST OREGON
LATER THURSDAY AND THURSDAY NIGHT. THIS LOOKS LIKE THE BEST FRONT WE
HAVE SEEN IN QUITE A WHILE...AND WE SHOULD SEE A DECENT DOSE OF RAIN
ACROSS OUR FORECAST AREA. SNOW LEVELS WILL REMAIN RATHER HIGH
THROUGHOUT MOST OF THIS EVENT...FINALLY DROPPING TO NEAR OR BELOW THE
CASCADE PASSES LATE THURSDAY NIGHT OR FRIDAY. BUT PRECIPITATION WILL
BE WANING AT THAT POINT...SO SNOW AMOUNTS WILL BE RATHER LIGHT IN THE
CASCADES. HAVE FOLLOWED THE 00Z NAM/ECMWF FOR TIMING BASED ON WPC`S
MODEL DIAGNOSTIC DISCUSSION. THE GFS CONSIDERABLY SLOWER. THE MAIN
UPPER LEVEL FORCING STILL PASSES BY TO THE NORTH AND THUS THE
PRECIPITATION WILL BE ON THE LIGHTER SIDE INITIALLY FOR THE VALLEYS
AND BETTER FOR ELEVATED TERRAIN...BUT THERE IS A DECENT
FRONTOGENETICAL SIGNATURE IN THE 850-700 MB LAYER AND MODEST PW
VALUES TO SUGGEST SOME DECENT RAIN BANDS EVEN FOR THE LOWLANDS
THURSDAY EVENING RIGHT WITH THE FRONT.THURSDAY WILL BE THE WARMEST
DAY AND YOU MAY ACTUALLY SEE THE SOUTH WIND BLOWING WHICH WILL BE THE
FIRST SIGNS OF A CHANGING AIR MASS...ALBEIT TEMPORARY.
WE MAY FINALLY GET OUT OF THESE RATHER STAGNANT CONDITIONS WITH THIS
FRONT...BUT THIS TRANSITION MAY NOT OCCUR UNTIL LATE THURSDAY OR
THURSDAY NIGHT. THE ONLY PROBLEM IS THAT THE WEEKEND LOOKS TO BE
SOMEWHAT STAGNANT UNDER A RETURNING RIDGE. KMD
.HYDROLOGY...THE HIGHEST TIDE OF THE 13/14 WINTER WILL BE ON NEW
YEARS DAY. WHILE RIVERS ARE LOW FOR THIS TIME OF YEAR AND TIDAL
ANOMALIES ARE NOTHING TO WRITE HOME ABOUT...THERE IS A CHANCE A FEW
ROADS ALONG THE COAST MAY HAVE AN ISSUE WITH FLOODING. THE MAIN AREA
OF CONCERN IS AROUND TILLAMOOK WHERE TILLAMOOK RIVER...FRASIER AND
BROUTON ROADS MAY BE VULNERABLE TO BRIEF FLOODING DURING HIGH TIDE ON
NEW YEARS DAY. /NEUMAN
.LONG TERM...MINOR CHANGES. PREVIOUS DISCUSSION GENERALLY FOLLOWS...
FRIDAY THROUGH MONDAY...THE FCST MODELS TRENDING
TOWARDS DRIER WEATHER LATE FRI THROUGH THE WEEKEND AS UPPER LEVEL
RIDGING RESTRENGTHENS OVER THE NE PAC. REMOVED ALL PRECIP CHANCES OUT
OF THE FCST OVER THE WEEKEND BASED ON THE PRETTY GOOD AGREEMENT OF
THE FCST ENSEMBLES FOR NEXT WEEKEND. THE NEXT CHANCE FOR
PRECIPITATION APPEARS TO BE A SYSTEM THAT WILL ATTEMPT TO PUSH
THROUGH THE TOP OF THE RIDGE EARLY NEXT WEEK. PYLE
&&
.AVIATION...MOSTLY VFR CONDITIONS EARLY THIS MORNING EXCEPT FOR
PARTS OF THE NORTHERN AND CENTRAL WILLAMETTE VALLEY WHERE THERE
HAS BEEN PERIODS OF LOCALIZED MVFR/IFR CONDITIONS. CIGS ALONG THE
NORTH COAST WILL LOWER TO MVFR WITHIN THE NEXT FEW HOURS AS A WARM
FRONT APPROACHES. THIS FRONT WILL SPREAD WIDESPREAD IFR CIGS
ACROSS THE NORTH LATER THIS MORNING WITH OCCASIONAL MVFR VSBYS IN
DRIZZLE. SOUTHERN AREAS SHOULD REMAIN MOSTLY VFR WITH A BRIEF
PERIOD OF MVFR LATER THIS MORNING. HIGHER TERRAIN TO REMAIN
OBSCURED IN CLOUDS INTO THE AFTERNOON. CONDITIONS SHOULD IMPROVE
INLAND AFTER 20Z WITH MVFR/VFR CONDITIONS INTO THE EVENING.
HARTLEY
KPDX AND APPROACHES...VFR FOR NEXT FEW HOURS...BUT AREAS OF IFR
STRATUS AND FOG ARE DEVELOPING AND SHOULD OVERTAKE THE KPDX OPS
AREA BY 13Z. CIGS WILL LIFT IN THE AFTERNOON AND EXPECT VFR
CONDITIONS AFT 21Z. HARTLEY
&&
.MARINE...ONLY CHANGE MADE TO THE MARINE FORECAST WAS TO ADD A
SMALL CRAFT ADVISORY FOR THE COLUMBIA RIVER BAR THIS AFTERNOON
DURING THE VERY STRONG EBB CURRENT. PREVIOUS DISCUSSION
FOLLOWS...LITTLE CHANGE FOR NEXT SEVERAL DAYS. SEAS HOLDING AT 7
TO 8 FT TONIGHT...BUT WILL SLOWLY SUBSIDE ON TUE AND TUE NIGHT.
NEXT THREAT OF ENHANCED WINDS NOT UNTIL LATER THU NIGHT AND FRI
WHEN A FRONT WILL PUSH ACROSS THE REGION. THIS FRONT LIKELY TO POP
20 TO 25 KT S WINDS...WITH SEAS BUILDING BACK TO 10 FT ON FRI.
THEN HIGH PRESSURE IS EXPECTED TO REDEVELOP...KEEPING CONDITIONS
RATHER BENIGN ON SAT AND SUN. ROCKEY/HARTLEY
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...AIR STAGNATION ADVISORY UNTIL 4 PM PST THURSDAY FOR CENTRAL
WILLAMETTE VALLEY-SOUTH WILLAMETTE VALLEY.
WA...NONE
PZ...SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR UNTIL 6 AM
PST EARLY THIS MORNING.
SMALL CRAFT ADVISORY FOR ROUGH COLUMBIA RIVER BAR FROM 2 PM
THIS AFTERNOON TO 6 PM PST THIS EVENING.
&&
$$
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 FOR WESTERN SD AND NORTHEASTERN WY
NWS RAPID CITY SD
358 PM MST TUE DEC 31 2013
.UPDATE...
ISSUED AT 353 PM MST TUE DEC 31 2013
CALL TO AREA SPOTTERS SHOWED A BAND OF SLEET/FREEZING RAIN FROM
SOUTHEAST MT INTO WESTERN MEADE COUNTY...INCLUDING THE I-90
CORRIDOR FROM STURGIS TO SPEARFISH TO MOORCROFT. 21Z RAP SHOWED
NARROW BAND OF MIXED PRECIPITATION POTENTIAL FOR THESE AREAS
THROUGH ABOUT 04Z...WHEN EVERYTHING SHOULD SHIFT TO -SN. HAVE
INTRODUCED THESE ELEMENTS TO FORECAST AND ISSUED HEADLINES FOR THE
APPROPRIATE AREAS.
&&
.SHORT TERM...THIS EVENING THROUGH WEDNESDAY NIGHT
ISSUED AT 208 PM MST TUE DEC 31 2013
UPPER LEVEL ANALYSIS SHOWS NORTHWEST FLOW OVER THE
NORTHERN PLAINS. SURFACE MAP HAS AN ARCTIC BOUNDARY STRETCHING FROM
MONTANA THROUGH THE CWA INTO NEBRASKA. WARMER TEMPS TO THE SOUTH OF
THE BOUNDARY ARE IN THE 30S...WITH TEMPS TO THE NORTH IN THE SINGLE
DIGITS. LOW STRATUS COVERS MUCH OF THE REGION...WITH RADAR
DISPLAYING SOME LIGHT SNOW SHOWERS. WINDS ARE LIGHT AND VARIABLE.
AS THE ARCTIC BOUNDARY SPREADS SOUTH TONIGHT AND A SHORTWAVE
APPROACHES FROM THE WEST...LIGHT SNOW WILL TRANSITION SOUTH WITH THE
BEST FRONTOGENESIS. GENERALLY A COUPLE ADDITIONAL INCHES OR LESS OF
SNOW IS EXPECTED TONIGHT...WITH THE GREATER AMOUNTS OVER PARTS OF
NORTHEAST WYOMING AND THE NORTHERN BLACK HILLS. LOWS WILL RANGE FROM
AROUND 5 BELOW ZERO ACROSS CENTRAL SD TO ABOUT 20 ABOVE ZERO FARTHER
WEST.
SURFACE HIGH PRESSURE WILL SLIDE ACROSS ND ON NEW YEAR`S DAY...AND THE
PRESSURE GRADIENT WILL TIGHTEN A LITTLE...CAUSING BREEZY NORTHWEST
WINDS ACROSS NORTHWEST SD. LIGHT SNOW WILL CONTINUE THROUGH MUCH OF
THE DAY...WITH MINIMAL ACCUMULATIONS MOST PLACES. THE FROUDE NUMBER
AROUND 1.5 INDICATES THE POSSIBILITY FOR UPSLOPE-ENHANCED SNOW OVER
THE NORTHERN HILLS...ACCUMULATING ANOTHER INCH OR TWO THERE. HIGHS
WILL RANGE FROM THE TEENS ACROSS CENTRAL SD TO THE LOWER 30S IN
SOUTHWEST SD AND NORTHEAST WY.
SNOW WILL DIMINISH AND SKIES WILL BEGIN TO CLEAR WEDNESDAY NIGHT.
LOWS WILL BE AROUND 10 BELOW TO 15 ABOVE ZERO.
&&
.LONG TERM...THURSDAY THROUGH TUESDAY
ISSUED AT 208 PM MST TUE DEC 31 2013
POWERFUL NORTHERN STREAM WILL CONTINUE TO DOMINATE THE
WEATHER IN THE PERIOD. MEAN CENTRAL CANADIAN POLAR VORTEX
WILL DRIVE ANOTHER SURGE OF ARCTIC AIR INTO THE REGION BY
SUNDAY...AS A LONG WAVE TROUGH ADVECTS ACROSS THE NW CONUS AND
PHASES WITH A PORTION OF THE POLAR LOW. PROGRESSIVE FLOW OVER THE
WESTERN ATLANTIC WILL SUPPORT ONLY A BRIEF STAY OF ARCTIC AIR
LOCALLY AS SEMI-ZONAL FLOW DEVELOPS ONCE AGAIN EARLY NEXT WEEK. MEAN
MODEL SOLUTIONS ARE SUGGESTING A POTENTIAL PATTERN CHANGE BY THE
MIDDLE OF NEXT WEEK WITH BREAKDOWN OF THE EASTERN PAC UPPER
RIDGE...ALLOWING A RETURN TO PROGRESSIVE FLOW OVER MUCH OF
NOAM...WITH THE POTENTIAL FOR A WARMER PATTERN AFTERWARD.
THUR-FRI...DEEP LAYER RIDGING AHEAD OF THE ADVECTING UPPER TROUGH
WILL SUPPORT STAUNCH WAA WITH WESTERLY FLOW SPREADING OVER THE
REGION. HAVE ADJUSTED TEMPS BOTH DAYS...WITH MILD CONDITIONS
EXPECTED OVER NE WY AND BH THUR...ALL PLACES FRIDAY AS FLOW
INCREASES AND MIXING SPREADS ACROSS THE SD PLAINS. 40S WILL BE
COMMON FRI...WITH 50S EXPECTED IN THE LEE OF THE BLACK
HILLS...INCLUDING RAPID CITY. THE RIDGE WILL SHIFT EAST FRIDAY
AFTERNOON...WITH A STRONG UPPER IMPULSE EXPECTED INTO THE
REGION...BRINGING INCREASING CHANCES FOR PRECIP...RAIN POSSIBLY AT
FIRST THEN TRANSITIONING TO SNOW FRIDAY EVENING. CONTINUED POP
MENTION IN THE PERIOD...OPTING FOR A MORNING MENTION OVER WY. ARCTIC
FRONT AND ASSOCIATED IMPULSE WILL ARRIVE SUN...WITH A CONTINUED POP
MENTION THEN. ALTHOUGH MOISTURE WILL BE SIGNIFICANTLY LACKING WITH
THIS SYSTEM...BEST CHANCES FOR ANY SNOW ACCUMS WILL BE OVER NE WY
AND THE NORTHERN BH. ARCTIC AIR WILL SURGE SOUTH ACROSS THE REGION
SUNDAY INTO MONDAY WITH VERY COLD TEMPS EXPECTED. MADE A SLIGHT DOWN
ADJUSTMENT TO TEMPS GIVEN BETTER MODEL AGREEMENT...ALTHOUGH CONCERNS
LINGER ON THE DEGREE OF CAA. WAA LOOKS TO ENSUE AS EARLY AS MON
AFTERNOON PER THE ECMWF...WITH A SLOW WARMUP ON TRACK THROUGH THE
MIDDLE OF NEXT WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z WEDNESDAY EVENING)
ISSUED AT 353 PM MST TUE DEC 31 2013
PRECIPITATION WILL OVERSPREAD THE AREA TONIGHT LEADING TO IFR
CIGS/VSBYS IN -SN...LIFR CONDITIONS LIKELY IN THE STRONGEST AREAS
OF -SN AND BLACK HILLS AREA. -FZRA/PL POSSIBLE THIS EVENING FROM
NORTHEAST WY INTO WEST CENTRAL SD.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY FOR SDZ012-024-
025-072.
WY...WINTER WEATHER ADVISORY UNTIL 5 AM MST WEDNESDAY FOR WYZ056-057-
071.
&&
$$
UPDATE...HELGESON
SHORT TERM...POJORLIE
LONG TERM...JC
AVIATION...HELGESON
AREA FORECAST DISCUSSION
NWS SIOUX FALLS SD
352 PM CST TUE DEC 31 2013
.SHORT TERM...(THIS EVENING THROUGH WEDNESDAY)
ISSUED AT 339 PM CST TUE DEC 31 2013
SNOW ASSOCIATED WITH TODAYS WAVE IS EXITING THE AREA...WITH JUST
SOME ISOLATED TO SCATTERED FLURRIES LINGERING. ANOTHER WAVE WILL RIDE
SOUTHEAST ALONG THE THERMAL GRADIENT TONIGHT. MODELS HAVE HAD GREAT
DIFFICULTY PINPOINTING WHERE THE BEST SNOW POTENTIAL WILL BE WITH
THIS WAVE...AND HOW MUCH QPF WILL FALL. THUS NEEDLESS TO SAY A LOW
CONFIDENCE FORECAST. BEST LARGE SCALE FORCING FROM THE WAVE SEEMS TO
GO TO OUR SOUTH. HOWEVER THE MID LEVEL FRONTAL BOUNDARY SHOULD BE
FURTHER NORTH...IN THE VICINITY OF THE MISSOURI RIVER VALLEY. LATEST
MODELS ARE TRENDING THE AREA OF SNOW FURTHER NORTH...CLOSER TO THE
REGION WHERE ISENTROPIC LIFT OVER THE MID LEVEL FRONT INTERACTS WITH
SOME OF THE LARGE SCALE FORCING. MODELS ALSO SHOWING SOME WEAK
INSTABILITY ABOVE THE FRONT...SUGGESTING WE COULD SEE SOME ENHANCED
BANDING. THE THERMAL PROFILE DOES FEATURE A DECENT SIZED AREA IN THE
DENDRITIC SNOW GROWTH ZONE...SUGGESTING RATIOS COULD END UP AROUND
15 TO 1. A CONSENSUS OF MODEL QPF VALUES SUGGEST 1 TO 2 INCHES IN
THE SNOW BAND...WITH ISOLATED AMOUNTS UP TO 3 INCHES IF RATIOS END
UP A BIT HIGHER. HOWEVER THE RUC...HRRR AND 18Z NAM ARE ALL MUCH
MORE AGGRESSIVE WITH QPF VALUES. THESE THREE WOULD SUGGEST A BAND OF
3 TO 5 INCHES. GIVEN THE LARGE SCALE FORCING...POTENTIAL BANDING AND
MODELS TRENDING UPWARD IN QPF...THIS CAN NOT BE COMPLETELY RULED
OUT. HOWEVER DO NOT WANT TO JUMP ON THIS AT THIS POINT GIVEN THE
REST OF THE GUIDANCE SUGGESTING LOWER AND THE MODEL INCONSISTENCY
FROM RUN TO RUN. THUS...TRENDED AMOUNTS UP...BUT ONLY TOWARDS MODEL
CONSENSUS...WHICH AT THIS TIME STILL SEEMS LIKE THE MORE LIKELY
SOLUTION.
THE NEXT QUESTION IS EXACTLY WHERE THIS BAND SETS UP. RIGHT
NOW ALMOST ALL GUIDANCE SUGGESTS THE MISSOURI RIVER VALLEY IS THE
MOST LIKELY LOCATION...WITH DECREASING AMOUNTS AS YOU GET TOWARDS
INTERSTATE 90. HOWEVER THE GEM AND HRRR ARE FURTHER NORTH...PUTTING
THE HIGHER AMOUNTS CLOSER TO OR JUST SOUTH OF INTERSTATE 90. FOR
THIS FORECAST PACKAGE WILL GO WITH THE MORE LIKELY SOLUTION ALONG
THE MISSOURI RIVER...BUT GIVEN THE RECENT NORTHWARD TRENDS CAN NOT
COMPLETELY RULE OUT THE HRRR AND GEM SOLUTION. SO FOR NOW...WILL
STICK WITH THE 1 TO 3 INCHES ALONG THE MISSOURI RIVER...DECREASING
TO AROUND AN INCH IN SIOUX FALLS AND LESS TO THE NORTH...BUT AS
MENTIONED ABOVE...EVENING SHIFT WILL NEED TO MONITOR TRENDS AND SEE
IF ADJUSTMENTS ARE NEEDED. EXPECT SNOW TO START AROUND 10 PM IN OUR
WEST...APPROACH SIOUX FALLS AND SIOUX CITY CLOSER TO MIDNIGHT...AND
SPENCER TO STORM LAKE AROUND 2 AM.
IT WILL BE A COLD ONE TONIGHT AS WELL WITH LOWS IN THE SINGLE DIGITS
BELOW ZERO NORTH OF INTERSTATE 90 AND SINGLE DIGITS ABOVE TO THE
SOUTH. KEPT THE TREND OF STAYING ON THE WARMER SIDE OF GUIDANCE
THOUGH...GIVEN THE CLOUD COVER AND AT LEAST A WEAKLY MIXED BOUNDARY
LAYER. WIND CHILLS WILL BE AROUND THE 20 BELOW ZERO ADVISORY CRITERIA
IN OUR NORTH. HOWEVER DECIDED TO HOLD OFF ON ONE AT THIS TIME...AS
WINDS SHOULD DROP OFF AFTER SUNSET AND GENERALLY BE UNDER 10
MPH...AND IF WINDS STAY UP MORE...TEMPERATURES WILL PROBABLY STAY A
BIT WARMER THAN FORECAST. THUS FEEL LIKE WIND CHILLS WILL HOVER A
FEW DEGREES EITHER SIDE OF 20 BELOW...AND GIVEN OUR COLD WINTER THUS
FAR...WILL NOT ISSUE ANOTHER ADVISORY AT THIS TIME. SNOW SHOULD EXIT
THE AREA FROM NORTHWEST TO SOUTHEAST ON WEDNESDAY MORNING...GIVING
WAY TO A MOSTLY CLOUDY DAY WITH JUST SOME SCATTERED FLURRIES. HIGHS
WILL WILL ONLY BE IN THE SINGLE DIGITS ABOVE AND BELOW ZERO WITH
WIND CHILLS LIKELY STAYING BELOW ZERO THROUGH THE DAY.
.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)
ISSUED AT 339 PM CST TUE DEC 31 2013
CONTINUED COLD WEATHER PATTERN LOCKED IN PLACE FOR THE MAJORITY OF
THE MID AND LONG RANGE FORECAST. PREDOMINATE NORTHWEST UPPER LEVEL
FLOW WILL USHER IN SEVERAL WAVES THROUGH THE PERIOD WHICH WILL
PROVIDE REINFORCING SHOTS OF ARCTIC AIR. THE FIRST BLAST OF COLD AIR
CONTINUES TO SPREAD ACROSS THE REGION WEDNESDAY NIGHT. LIGHT
NORTHERLY WINDS AND DECREASING CLOUDS WILL LEAD TO EXTREMELY COLD
LOWS IN THE TEENS BELOW ZERO ACROSS THE BULK OF THE FORECAST
AREA...WITH THE SINGLE DIGITS BELOW CLOSER TO THE MISSOURI RIVER.
WIND CHILLS WILL BE BRUTALLY COLD AROUND 20 TO 30 BELOW FOR A LARGE
AREA...BUT WINDS SHOULD REMAIN WELL BELOW THE 10 MPH THRESHOLD FOR A
WIND CHILL HEADLINE.
THURSDAY WILL AGAIN BE VERY COLD WITH LIGHT WINDS TURNING A LITTLE
MORE SOUTHERLY IN THE AFTERNOON AS SURFACE HIGH PRESSURE SLIPS OFF
TO OUR EAST. MOSTLY CLEAR SKIES IN THE MORNING WILL SEE AN INCREASE
IN CLOUD COVER FROM THE WEST LATER IN THE DAY AHEAD OF THE NEXT
INCOMING SHORTWAVE. TEMPERATURES WILL NOT WARM MUCH...WITH MANY
LOCATIONS ONLY REACHING HIGHS AROUND ZERO. RETURN FLOW INCREASES
THURSDAY NIGHT AND FRIDAY...LEADING INTO THE ONLY MILD DAY OF THE
PERIOD. AFTER A SLIGHT DIP IN TEMPERATURES THURSDAY EVENING...
TEMPERATURES SHOULD BEGIN RISING OVERNIGHT WHILE CLOUDS INCREASE.
SOUTHERLY WINDS BECOME BREEZY ON FRIDAY...ESPECIALLY ACROSS OUR
EASTERN HALF...HOWEVER HIGHS ARE EXPECTED TO IMPROVE SOME 20 DEGREES
OR MORE FROM THURSDAY HIGHS. BLOWING AND DRIFTING OF THE RECENT
SNOWFALL COULD BE A CONCERN AS THE WINDS INCREASE ON FRIDAY.
STRONG COLD FRONT DIVES ACROSS THE REGION ON FRIDAY NIGHT...BRINGING
THE NEXT CHANCE OF SOME LIGHT SNOW ALONG AND BEHIND THE FRONT. UPPER
LEVEL TROUGH SINKS SOUTH OF THE FORECAST AREA LATE SATURDAY
NIGHT...USHERING IN ANOTHER ARCTIC BLAST FOLLOWED BY A REINFORCING
SHOT OF COLD AIR LATE SUNDAY AND SUNDAY NIGHT. LOW TEMPERATURES WILL
BE BACK INTO THE TEENS BELOW ZERO SUNDAY NIGHT AND MONDAY
NIGHT...WITH HIGHS EXPECTED TO BE BELOW ZERO FOR THE MAJORITY OF THE
FORECAST AREA. NORTHWEST WINDS ARE EXPECTED TO BE BREEZY SUNDAY
NIGHT INTO MONDAY WHICH PLACES NEARLY THE ENTIRE FORECAST AREA
SQUARELY INTO WIND CHILL WARNING TERRITORY AND AS COLD AS 35 TO 45
BELOW ZERO.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z WEDNESDAY AFTERNOON)
ISSUED AT 1138 AM CST TUE DEC 31 2013
AREA OF LIGHT TO MODERATE SNOW WILL CONTINUE TO PUSH EAST ACROSS THE
AREA EARLY THIS AFTERNOON. VISIBILITY REDUCTIONS TO IFR ARE COMMON IN
THIS SNOW...MAINLY NORTH OF INTERSTATE 90. EXPECT THE SNOW TO COME TO
AN END FROM WEST TO EAST THROUGH THE AFTERNOON HOURS. A SECOND WAVE
SLIDING SOUTHEAST SHOULD BRING ANOTHER ROUND OF MAINLY LIGHT SNOW TO
THE AREA LATER TONIGHT INTO EARLY WEDNESDAY. LOOKS LIKE WE COULD SEE
VISIBILITY BACK INTO THE MVFR RANGE AFTER MIDNIGHT OVER A GOOD
PORTION OF THE AREA. THE STEADIEST SNOW IS CURRENTLY EXPECTED TO BE
SOUTH OF INTERSTATE 90...WHERE PERIODS OF IFR VISIBILITY ARE
POSSIBLE...THUS INTRODUCED A TEMPO INTO THE SUX TAF. CONFIDENCE OF
DROOPING BELOW 3SM IS LESS FURTHER NORTH...AND THUS KEPT THE FSD AND
HON TAF MVFR. SNOW SHOULD END FROM NORTHWEST TO SOUTHEAST THROUGH THE
EARLY MORNING. CIGS ARE TOUGH TO DETERMINE IN THESE ARCTIC AIR
MASSES. BASED ON WHAT IS OUT THERE NOW...DECIDED TO KEEP THE STRATUS
IN THE VFR RANGE WHEN IT IS NOT SNOWING...BUT THESE CLOUDS COULD END
UP LOWER BASED...SO SOMETHING TO KEEP AN EYE ON.
&&
.FSD WATCHES/WARNINGS/ADVISORIES...
SD...NONE.
MN...NONE.
IA...NONE.
NE...NONE.
&&
$$
SHORT TERM...CHENARD
LONG TERM...
AVIATION...CHENARD
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
849 PM CST WED JAN 1 2014
.UPDATE...
LATEST MOSAIC AND OHX RADAR IMAGERY SHOW LIGHT RAIN HAS ALREADY
DEVELOPED ACROSS WESTERN TN WITH ECHOES NOW SPREADING INTO
WESTERN ZONES. BASED ON THIS ADJUSTED POPS UPWARD FOR THE
REMAINDER OF THE NIGHT FOR ALL ZONES...WITH PRECIP CHANCES NOW
MORE IN LINE WITH 18Z/00Z RUNS. TEMPS SEEM REASONABLE AND WERE NOT
CHANGED...WITH TEMPS LIKELY FALLING SOME MORE THIS EVENING BEFORE
BECOMING STEADY OR RISING OVERNIGHT AS WAA INCREASES.
FOR THURSDAY...THE JUST IN 00Z NAM CONTINUES TO SHOW STRONG COLD
FRONT RACING ACROSS THE AREA DURING THE MORNING HOURS WITH
PRECIPITATION EXITING RIGHT ON ITS HEELS. AS WITH THE
GFS/ECMWF...NAM SHOWS MOISTURE MOVING OUT AT SAME TIME AS COLD AIR
RUSHES IN WITH ONLY A BRIEF WINDOW FOR A MIX/CHANGEOVER TO SNOW
DURING THE MORNING AND EARLY AFTERNOON HOURS FOR LOCATIONS WEST OF
THE PLATEAU. 01Z RAP AGREES WITH THIS SCENARIO...WHILE 18Z
GFS/12Z ECMWF ARE COLDER WITH PRECIPITATION LINGERING LONGER
BEHIND THE FRONT. THUS APPEARS BEST CHANCE FOR ANY SNOW ACCUMS
WEST OF THE PLATEAU ON THURSDAY WILL BE ACROSS NORTHWEST ZONES
WHERE WAA WILL HAVE LESS IMPACT AND CAA ARRIVES QUICKEST...AND A
DUSTING TO HALF INCH OF SNOW SEEMS POSSIBLE THERE. REST OF THE
CWA OFF THE PLATEAU MAY STAY TOO WARM BEFORE PRECIP EXITS WITH
LITTLE IF ANY SNOW ACCUMS. ON THE PLATEAU...WEST TO NORTHWEST
FLOW WILL FORCE MOISTURE UP THE HIGHER TERRAIN AND CHANGE RAIN
OVER TO SNOW DURING THE AFTERNOON...WITH LIGHT SNOW CONTINUING
INTO AT LEAST THE EVENING HOURS. APPEARS AREAS FROM MONTEREY TO
CROSSVILLE TO JAMESTOWN COULD EASILY SEE AROUND 1 INCH OF SNOW
ACCUM...POSSIBLY HIGHER...AND A WINTER WEATHER ADVISORY MAY BE
NEEDED FOR THE NORTHERN PLATEAU COUNTIES MAINLY DUE TO TRAVEL
IMPACTS AS TEMPERATURES FALL INTO THE 20S AND 10S BEFORE SNOW
COMES TO AN END. WILL LET MID SHIFT TAKE A LOOK AT THE FULL 00Z
MODEL SUITE BEFORE DECIDING ON WHETHER A WWA IS NEEDED.
SHAMBURGER
&&
.PREV DISCUSSION... /ISSUED 531 PM CST WED JAN 1 2014/
UPDATE...FOR 00Z AVIATION FORECAST
AVIATION...
LOW PRESSURE OVER TX WILL PUSH EAST TOWARDS MIDDLE TN OVERNIGHT.
CLOUDS AND PRECIP WILL BE ON THE INCREASE...WITH MVFR CONDITIONS
FROM LOWER CIGS AND VSBYS DUE TO LIGHT RAIN PRIOR TO 12Z THURS AT
CKV/BNA AND POSSIBLY CSV. COLDER AIR WILL ACCOMPANY THE LOW/S
COLD FRONTAL PASSAGE WHERE RAIN SHOULD CHANGEOVER TO A RASN MIX
AND THEN ALL SNOW BEFORE EXITING. WITH THE FROPA...CIGS COULD DROP
TO IFR AS WINDS SHIFT AROUND TO THE NW AND BECOME QUITE
GUSTY...ROUGHLY GUSTING UP TO 25-35KTS AT THE TERMINALS THURSDAY
AFTERNOON. THE FROPA SHOULD PASS THROUGH CKV BY 14Z...BY 15Z AT
BNA AND BY 20Z AT CSV...WITH SN LASTING A FEW HOURS THEREAFTER.
PREV DISCUSSION... /ISSUED 139 PM CST WED JAN 1 2014/
DISCUSSION...SURFACE MAP AT 18Z SHOWS A WARM FRONT SITUATED NORTH
OF THE OHIO VALLEY ATTACHED TO A LOW CENTERED ALONG THE TX/OK
BORDER. SUNNY SKIES COVER MOST OF MIDDLE TENNESSEE, WITH DEW
POINTS MAINLY IN THE 20`S. WITH TEMPERATURES THIS HOUR RUNNING
45-50 DEGREES, THIS IS THE WARMEST WEATHER WE`LL SEE FOR QUITE A
WHILE. THE AFOREMENTIONED LOW CENTER WILL MOVE ENEWD OVERNIGHT AND
WILL COMBINE WITH ENOUGH GULF MOISTURE TO PRODUCE WIDESPREAD,
MAINLY LIGHT PRECIPITATION TONIGHT AND TOMORROW. NAM BRINGS THE
SURFACE LOW DIRECTLY ACROSS NORTHERN MIDDLE TENNESSEE, WITH ENOUGH
WRAP- AROUND MOISTURE TO PRODUCE EITHER SNOW, OR A RAIN/SNOW
MOISTURE LATE TONIGHT AND MUCH OF THE DAY TOMORROW, AND SOME
ACCUMULATION (GENERALLY <1") MAINLY ACROSS OUR NORTH WHERE
TEMPERATURES WILL BE COLDEST. THE UPPER TROUGH SHOULD MOVE ACROSS
THE MID STATE BY 00Z FRIDAY, WITH STRONG HIGH PRESSURE OVER THE
UPPER MIDWEST BRINGING FRIGID TEMPERATURES TO THE AREA. A SECOND
SYSTEM ON SUNDAY/SUNDAY NIGHT WILL TAKE A SIMILAR TRACK, WITH SNOW
POSSIBLE WITH THE OCCLUDED FRONT. AT THIS TIME, THE ECMWF IS THE
SLOWER, COLDER MODEL, WITH THE GFS BRINGING THIS SYSTEM THROUGH
MUCH MORE QUICKLY. STILL, TEMPERATURES BEHIND THIS SYSTEM WILL BE
THE COLDEST OF THE SEASON THUS FAR, WITH SINGLE DIGIT READINGS
POSSIBLE EARLY NEXT WEEK, AND SUB-ZERO WIND CHILLS AT TIMES.
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
544 PM CST WED JAN 1 2014
.AVIATION...
MVFR CIGS SHOULD HANG IN FOR THE SAT/SSF SITES AND AREAS EAST OF
AUS WHILE AUS ITSELF SHOULD BREAK OUT TO VFR BY MID EVENING. THERE
COULD BE A FEW POCKETS OF LOW CIGS TO POOL AROUND AUS NEAR THE
TIME OF A FRONTAL PASSAGE EXPECTED AROUND 05Z. BASED ON THE RUC
MODEL...THE TIMING OF THE FRONT WAS LEFT FROM THE PREVIOUS SHIFT
FOR AUS AND DRT...BUT SLOWED DOWN TO 0630-07Z FOR SAT/SSF. GUSTY
N WINDS TO AROUND 25 KNOTS SHOULD RELAX AFTER 18Z THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 305 PM CST WED JAN 1 2014/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
THIS AFTERNOON A PERSISTENT STRATOCU DECK WAS LOCATED EAST OF A LINE
FROM CARRIZO SPRINGS TO FREDERICKSBURG TO GEORGETOWN. THIS CLOUD DECK
WILL SLOWLY ERODE FROM WEST TO EAST THIS EVENING IN ADVANCE OF THE
COLD FRONT. AT 21Z THE COLD FRONT WAS LOCATED OVER THE TEXAS SOUTH
PLAINS MOVING SOUTHWARD. THE FRONT WILL ENTER THE HILL COUNTRY
BETWEEN 10 AND 11 PM THIS EVENING BASED ON THE LATEST RUC13 MODEL
SOLUTION. THIS WILL BE A DRY FROPA...HOWEVER A BRIEF PERIOD OF
PRE-FRONTAL PATCHY FOG IS POSSIBLE SOUTH AND EAST OF THE I-35
CORRIDOR WITH MORE WIDESPREAD FOG POSSIBLE ACROSS DIMMIT AND
SOUTHERN MAVERICK COUNTIES. POST-FRONTAL WINDS TONIGHT WILL BE
NORTHERLY AT 10 TO 20 MPH WITH GUSTS OF 30 MPH. LOWS THURSDAY
MORNING WILL RANGE FROM AROUND 30 ACROSS THE HILL COUNTRY TO NEAR
40 SOUTHWEST. THURSDAY WILL BE SUNNY AND COOLER AS CAA CONTINUES
THROUGHOUT THE DAY. HIGHS THURSDAY WILL BE 8 TO 12 DEGREES BELOW
NORMAL. GUSTY NORTHERLY WINDS WILL DIMINISH BY EVENING WITH THE
WEAKENING PRESSURE GRADIENT. GOOD RADIATIONAL COOLING WILL OCCUR
THURSDAY NIGHT INTO FRIDAY MORNING. THIS WILL RESULT IN A HARD
FREEZE FOR MUCH OF SOUTH CENTRAL TEXAS. THE LOW TEMP FCST FOR
THURSDAY NIGHT WILL BE A BLEND OF THE MET/MAV/ECMWF MOS GUIDANCE.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
BELOW NORMAL TEMPERATURES WILL CONTINUE NEXT WEEK DUE TO A SERIES
OF FROPAS. HOWEVER A BRIEF WARMING TREND WILL OCCUR FRIDAY AND
SATURDAY. HIGHS ON SATURDAY WILL BE IN LOWER 60S ACROSS THE HILL
COUNTRY WITH MID 60S ACROSS THE REMAINDER OF SOUTH CENTRAL TEXAS.
THE NEXT COLD FRONT WILL MOVE ACROSS THE REGION ON SUNDAY. ONCE
AGAIN AFTERNOON HIGHS WILL BE 5 TO 8 DEGREES BELOW NORMAL...RANGING
FROM THE UPPER 40S HILL COUNTRY TO NEAR 60 SOUTHWEST. LOW LEVEL
MOISTURE WILL BE LIMITED...WITH ONLY A SLIGHT CHANCE OF SHOWERS
FOR OUR EXTREME EASTERN COUNTIES. A RE-ENFORCEMENT OF THE COLD
AIRMASS WILL OCCUR ON TUESDAY WITH THE PASSAGE OF ANOTHER COLD
FRONT. WAA/OVERRUNNING/ISENTROPIC LIFT ON WEDNESDAY WILL LEAD TO
A SLIGHT CHANCE OF SHOWERS FOR MUCH OF THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 36 52 29 53 40 / 0 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 33 51 24 52 35 / - 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 35 54 26 54 37 / 0 0 0 0 0
BURNET MUNI AIRPORT 31 49 24 52 37 / 0 0 0 0 0
DEL RIO INTL AIRPORT 36 55 30 55 38 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 31 50 24 52 39 / 0 0 0 0 0
HONDO MUNI AIRPORT 37 57 25 55 38 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 35 52 26 54 37 / 0 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 36 51 28 53 41 / 10 0 0 0 0
SAN ANTONIO INTL AIRPORT 37 56 28 55 40 / 0 0 0 0 0
STINSON MUNI AIRPORT 39 57 29 56 41 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...02
PUBLIC SERVICE/DATA COLLECTION...33
AREA FORECAST DISCUSSION
NWS SPOKANE WA
901 AM PST Tue Dec 31 2013
.SYNOPSIS...
Weak storm systems will transit the region through this evening bringing
a mixed bag of light wintry precipitation. A stronger storm system
will pass through Thursday night bringing mainly rain in the
valleys and snow in the mountains. A cooler and drier pattern is
expected through the weekend.
&&
.DISCUSSION...
Minor morning updates to the forecast primarily include expanding
the intensity/mention of fog in the Basin/Moses Lake vicinity
today, otherwise no other significant change was made as long-wave
ridge axis positioning is off the coast and keeps a weak northwest
to southeast path over Eastern Washington and Northern Idaho for
disturbances to pass through with the most recent HRRR model runs
hinting of such a weak disturbance doing just that, so pops remain
in moderate shape form along with generally light QPF/snow
amount assigned. /Pelatti
&&
.AVIATION...
18Z TAFS: Weak weather disturbance dropping down in a northwest to
southeast trajectory allows the minor mention of precipitation,
including rain,snow, or even freezing rain given the persistent
inversion keeping a warm layer of air aloft which would support
melting of precipitation as it falls through it. Otherwise low
level clouds and fog remain and may stubbornly do so for a good
portion of the TAF interval thus IFR/LIFR ceilings and
visibilities remain depicted primarily in the overnight and
morning hours. /Pelatti
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 37 26 36 28 38 31 / 20 10 10 20 30 60
Coeur d`Alene 37 29 38 30 40 31 / 30 20 10 20 30 80
Pullman 41 30 40 31 41 33 / 50 10 10 10 10 60
Lewiston 44 31 41 32 45 35 / 40 20 10 10 10 60
Colville 32 25 33 27 33 29 / 20 10 20 30 30 60
Sandpoint 36 28 36 29 37 30 / 40 20 20 30 30 80
Kellogg 37 31 37 31 37 31 / 70 40 20 20 30 90
Moses Lake 39 22 35 23 36 30 / 10 0 0 10 10 20
Wenatchee 41 26 36 27 37 30 / 10 0 0 10 20 20
Omak 34 22 32 23 33 26 / 10 0 10 10 20 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...Air Stagnation Advisory until Noon PST Friday for East Slopes
Northern Cascades-Moses Lake Area-Northeast Mountains-
Okanogan Highlands-Okanogan Valley-Spokane Area-Upper
Columbia Basin-Waterville Plateau-Wenatchee Area.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
352 AM CST THU JAN 2 2014
.DISCUSSION...
212 AM CST
SHORT TERM FORECAST WILL BE ARRIVING SHORTLY...
MONDAY THROUGH WEDNESDAY...
MAJOR ARCTIC BLAST ARRIVES EARLY MONDAY MORNING...WITH THE LATEST
GUIDANCE SHOWING NO SIGNS OF BACKING OFF ON THE DANGEROUSLY COLD
LOWS AND HIGH TEMPS FOR THE THE MON/TUE TIMEFRAME.
ENSEMBLES FOR OVER A WEEK NOW HAVE INDICATED AN ARCTIC BLAST
ARRIVING FOR THE START OF NEXT WEEK...AND THIS CONTINUES TO BE THE
THEME. THE 500MB TROUGH AXIS ARRIVES OVER THE GREAT LAKES REGION
MON...AND WITH WEAK RIDGING OVER THE WESTERN ATLANTIC OCEAN
STRETCHING NORTH THROUGH THE CANADIAN MARITIME. THIS RIDGING WILL
LIKELY SLOW THE FORWARD PROGRESSION TO THE TROUGH AXIS...ALLOWING IT
TO LINGER LONGER OVER THE GREAT LAKES INTO TUE. THEN HEADING INTO
WED THE RIDGING OVER THE WESTERN ATLANTIC BEGINS TO PUSH
EAST...WHICH WILL ALLOW FOR A RELATIVELY MORE FLUID ATMOSPHERE AND
THE TROUGH AXIS WILL DRIFT EAST/NORTHEAST TOWARDS NEW ENGLAND.
AS PREVIOUSLY NOTED ABOUT THE COLD AIR...ENSEMBLES FOR NUMEROUS DAYS
HAVE BEEN PAINTING A HIGH CONFIDENCE THAT AT 850MB TEMPS BY EARLY
MON WILL BE ARND -24 TO -28 DEG C...WITH A POCKET OF -30 DEG C JUST
NORTH OF THE FORECAST AREA INTO CENTRAL/NORTHERN WISC. WITH THE SLOW
FORWARD PROPAGATION TO THE MID-LVL TROUGH...THIS WILL LIKELY KEEP
THE POTENT THERMAL TROUGH OVERHEAD INTO TUE. CLOSER TO THE SFC
RIDGING IS EXPECTED TO PUSH IN BEHIND THE ARCTIC FRONTAL BOUNDARY
AND PROVIDE RELATIVELY LITTLE IN THE WAY OF PRECIP TO THE FORECAST
AREA MON/TUE. UNFORTUNATELY WITH HOW COLD TEMPS WILL BE ALOFT AND A
THICK BLANKET OF SNOW...SFC TEMPS WILL EASILY HOLD WELL BELOW ZERO
FOR HIGHS BOTH MON/TUE. AT THIS TIME HIGH TEMPS MAY STRUGGLE ON BOTH
DAYS TO REACH -5 DEG F...WITH POSSIBLY A FEW LOCATIONS IN OUR
WESTERN CWFA STRUGGLING TO REACH -10 DEG C MON AFTN.
DEPENDING ON CLOUD COVER...OVERNIGHT LOWS COULD EASILY APPROACH
RECORD LOWS AT -15 TO -20 DEG F IN THIS TIMEFRAME. THE COMBINATION
OF DANGEROUSLY COLD SFC TEMPS...AND A GRADIENT PRODUCING BREEZY
CONDITIONS...WILL SET THE STAGE FOR WIND CHILL VALUES LIKELY TO
EXCEED -30 BELOW AND POSSIBLY APPROACH -40 DEG MON NGT. THE
GRADIENT SLACKENS FOR TUE NGT...HOWEVER WIND CHILL VALUES WILL ONCE
AGAIN APPROACH -20 TO -30 DEG F.
THEN TOWARDS THE MIDDLE OF NEXT WEEK THE TROUGH AXIS PIVOTS
EAST...WITH FLOW TURNING SOUTH/SOUTHWEST AND ADVECTING MUCH WARMER
AIR INTO THE REGION. ENSEMBLES HAVE CONTINUED TO INDICATE RELATIVELY
HIGH CONFIDENCE IN THE LONGER TERM PERIODS...WITH A MID-LVL TROUGH
DIGGING INTO THE SOUTHERN PLAINS AND POSSIBLY LEADING TO YET ANOTHER
ACTIVE PERIOD OF WEATHER FOR THE MIDDLE OF NEXT WEEK.
CONFIDENCE IN TEMPS MON/TUE...HIGH.
CONFIDENCE IN WIND CHILL VALUES MON/TUE...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 09Z...
* LIGHT TO MODERATE LAKE EFFECT SNOW INTO THE AFTERNOON WITH BRIEF
PERIODS OF HEAVIER SNOW AND IFR CIGS/VSBYS.
* NORTHEAST WINDS BECOMING NORTH-NORTHEAST BY MORNING THEN NORTH-
NORTHWEST BY AFTERNOON.
LENNING
//DISCUSSION...UPDATED 06Z...
LARGER SCALE SWATH OF SNOW HAS MOSTLY SLID SOUTH OF THE ORD/MDW
AREA BUT A BROAD LAKE EFFECT BAND IS SUPPORTING CONTINUED LIGHT
SNOW WITH BLOWING SNOW. EXPECT THIS BAND TO PERSIST INTO THE
MORNING AND LIKELY INTENSIFY AT TIMES WHILE GRADUALLY SHIFTING
FROM THE ILLINOIS SIDE TO THE INDIANA END AS WINDS BACK FROM
NORTHEAST TO NORTH NORTHEAST. THE PEAK PERIOD FOR MORE INTENSE
SNOWFALL AT THE ORD/MDW TERMINALS STILL APPEARS TO BE TOWARD
DAYBREAK INTO THE MORNING HOURS BEFORE ACTIVITY DROPS SOUTH.
AS PER THE PREVIOUS DISCUSSION...MODERATE TO HEAVY SNOW IS
POSSIBLE WITH 1/2 TO POTENTIALLY 1/4SM VSBY AT TIMES...WITH
SEVERAL INCHES OF ACCUMULATION DEPENDING ON HOW LONG THE BAND IS
OVERHEAD.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 09Z...
* HIGH CONFIDENCE OF ACCUMULATING LAKE EFFECT SNOW PERSISTING INTO
THE AFTERNOON. MEDIUM CONFIDENCE ON ENDING TIME AROUND 21-22Z.
* MEDIUM TO HIGH CONFIDENCE OF SEEING PERIODS OF IFR VSBYS. LOWER
CONFIDENCE OF LIFR TODAY.
* HIGH CONFIDENCE IN WIND TRENDS BECOMING NORTHWEST THIS AFTERNOON.
LENNING
//OUTLOOK FOR ORD/MDW FOR 12Z FRIDAY-12Z WEDNESDAY...UPDATED 00Z...
FRIDAY...VFR.
SATURDAY...SNOW SHOWERS ARRIVE AFTERNOON...MVFR/IFR LIKELY.
SUNDAY...CHANCE SNOW SHOWERS AND MVFR/IFR.
MONDAY AND TUESDAY...BREEZY AND VFR...SOME MVFR POSSIBLE MONDAY.
MDB
&&
.MARINE...
326 AM CST
MAIN CONCERN IS STRONG LOW PRESSURE PASSING NORTH OF THE LAKES
FRIDAY NIGHT. LATEST MODELS CONTINUE THE TREND OF INCREASING WINDS
AND GUSTS FRIDAY NIGHT...SO ELECTED TO REPLACE THE GALE WATCH WITH
A STORM WATCH. REGARDLESS OF THE EXACT TRACK AND STRENGTH OF THE
LOW...FEEL FAIRLY CONFIDENT OF SEEING AT LEAST A PERIOD OF STORM
FORCE GUSTS...BUT NOT QUITE CONFIDENT ENOUGH YET TO GO WITH THE
WARNING. THESE STORM FORCE WINDS WOULD BE PRECEEDED BY GALES
FRIDAY AFTERNOON AND FOLLOWED BY GALES SATURDAY...BUT WILL CARRY
JUST A STORM WATCH FOR THE ENTIRE PERIOD TO AVOID COMPLICATING THE
HEADLINES.
IN THE NEARSHORE...GALES LIKELY WILL DEVELOP LATE FRIDAY INTO
SATURDAY DURING THE SAME PERIOD AS THE STORM FORCE WINDS IN THE
OPEN WATERS. SMALL CRAFT ADVISORIES CURRENTLY IN EFFECT DO LOOK
LIKE THEY CAN BE DROPPED FOR A SHORT TIME EARLY ON FRIDAY BEFORE
CONDITIONS RAPIDLY INCREASE AGAIN. TO DRAW ATTENTION TO THE SHORT
BREAK BEFORE THE NEW SYSTEM APPROACHING FRIDAY...AND TO AVOID
RUNNING THE HEADLINES TOGETHER...ELECTED TO HOLD OFF ON ISSUING A
GALE WATCH AT THIS TIME BUT DID MENTION IT IN THE FORECAST TEXT.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...LAKE EFFECT SNOW WARNING...ILZ006 UNTIL 3 PM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY
TO 10 AM FRIDAY.
LAKE EFFECT SNOW WARNING...ILZ014 UNTIL 6 PM THURSDAY.
WINTER WEATHER ADVISORY...ILZ013-ILZ022-ILZ023-ILZ032-ILZ033-
ILZ039 UNTIL 6 AM THURSDAY.
LAKE EFFECT SNOW ADVISORY...ILZ013-ILZ022 UNTIL 6 PM THURSDAY.
IN...LAKE EFFECT SNOW WARNING...INZ001 UNTIL MIDNIGHT FRIDAY.
WINTER WEATHER ADVISORY...INZ001-INZ002-INZ010-INZ011-INZ019
UNTIL 6 AM THURSDAY.
LAKE EFFECT SNOW ADVISORY...INZ002...3 PM THURSDAY TO 4 AM
FRIDAY.
LM...STORM WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON FRIDAY TO 4 PM
SATURDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 4 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 9 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
[top]
Area Forecast Discussion
National Weather Service Lincoln IL
330 AM CST Thu Jan 2 2014
.DISCUSSION...
ISSUED 330 AM CST Thu Jan 2 2014
SHORT TERM...Today through Sunday night
Winter will keep a tight grip over central and southeast IL during
the next week with arctic airmasses visiting the region into the
middle of next week along with a couple of weather systems
bringing more snow. Will expire the winter weather advisory along
and northwest of I-55 with forecast package at 4 am and continue
the winter wx advisory until 9 am for eastcentral and southeast IL.
Snowfall total have generally averaged 2-3 inches acorss central
IL with lesser amounts in our far southeast counties where mixed
precipitation occurred since it begin late Wed evening, plus a dry
slot in that area too keeping precipitation lighter. Still have
band of light snow from I-55 southeast which HRRR diminishes from
nw to se through 15Z/9 am. Up to another inch of snow possible
east of I-55 with 1-2 inches more snow east of I-57. Gusty nnw
winds today to cause some low drifting across east-west roads.
Elongated 1013 mb low pressure from southern Indiana into NW TN
early this morning to eject quickly to the mid Atlantic coast by
sunset and produce a winter storm over the Northeast States into
Friday. Scattered flurries over even a few light snow showers
possible over eastern IL this afternoon especially over east
central IL but any additional snow accumulations should be
confined ne of our area closer to the Great Lakes region. Highs
today range from 10-15F over the IL river valley, to the low to
mid 20s in southeast IL.
Will issue a wind chill advisory along and nw of a Rushville to
Bloomington/Normal line tonight and Friday morning for wind chills
getting down to 15-20 below zero. 1037 mb arctic high pressure
over the eastern Dakotas and nw MN to settle into the mid MS
valley Friday morning and bring very cold temps back into the
region. Clouds to decrease from west to east during tonight and
winds to also diminish allowing temps to drop into the single
digits below zero over central IL with Galesburg 10 below or even
colder. High pressure drifts east into the mid Atlantic states by
Friday evening with increaing south winds and fair amount of
sunshine but still cold highs in the upper teens and lower 20s
with fresh snow cover. Breezy south winds continue Sat with milder
temps in the low to mid 30s. Also have 20-40% chance of light snow
from I-55 nw during Sat afternoon with next wx system approaching.
Strong upper level trof to dig into the Midwest by Sunday with low
pressure ejecting ne from the southern plains into the eastern
great lakes region as it deepens. Snow to develop across central
IL Sat night and continue Sunday with be heaviest in southeast IL
where several inches of snow possible. Areas nw by the IL river
valley appear to be on nw fringe of this storm system with ligher
snow amounts. Snow to diminish during Sunday night as storm system
pulls away.
LONG TERM...Monday through Wednesday night
The coldest air of the season still slated to arrive early next
work with from Sunday night through Tue night with subzero lows
returning to central and even southeast IL by Monday night with
northern areas 10-15 below zero. Wind chills Monday night into Tue
morning to get to 20-35 below zero and coldest from I-74 north.
Flurries possible over eastern IL monday with deep upper level
trof in place. Then next weather system appears to arrive by Wed
afternoon into Thu with next chance of snow with light snow
accumulations possible then. Models trending upward with temps
later next week as upper level heights rise, but skeptical about
too fast of warmup with snow pack in place.
07
&&
.AVIATION...
ISSUED 1137 PM CST Wed Jan 1 2014
Snow is beginning to taper off some in the northwest and should
affect PIA first, then BMI and SPI, followed by DEC and then
lastly CMI. IFR conditions still continue at all sites, but think
conditions will improve overnight in next 2-3 hours. So expecting
MVFR conditions at PIA at onset, at 08z for SPI and BMI, 09z at
DEC and 10z for CMI. Then VFR conditions a couple hours after
that, respectively. However, NAM model hangs on to some low level
moisture and flurries/light snow tomorrow from late morning into
the afternoon/evening in the east. So have added mention of light
snow or flurries at TAF sites, with lowest vis/cigs in east, and
longest as well. Then expecting clouds to scatter out as high
pressure area moves into the region for late tomorrow night. Winds
will be out of the north and increasing in wind speed as gradient
tightens overnight. North to northwest winds will continue through
tomorrow and be gusty. Gusty winds will decrease tomorrow evening
as gradient loosens, which will be around same time as clouds
scattering out.
Auten
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 9 AM CST this morning FOR
ILZ044>046-054>057-061>063-066>068-071>073.
WIND CHILL ADVISORY from 6 PM this evening to Noon CST Friday
FOR ILZ027>031-036>038-040-041.
WINTER WEATHER ADVISORY until 6 AM CST early this morning FOR
ILZ043-052-053.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1157 PM CST WED JAN 1 2014
.UPDATE...
ISSUED AT 1144 PM CST WED JAN 1 2014
THE WINTER WEATHER ADVISORY FOR THE SOUTHERN COUNTIES WILL BE
ALLOWED TO EXPIRE AT MIDNIGHT. THE REGIONAL RADAR COMPOSITES SHOW
THE BACK EDGE OF THE SNOW OVER THE FAR SOUTHEAST CORNER OF THE
CWFA WITH VSBYS AT MACOMB KMQB AT 7SM AS OF 1135 PM. THE SNOW CONTINUED
TO MOVE SOUTHEAST AND SHOULD BE OUT OF THE CWFA BY OR SHORTLY
AFTER MIDNIGHT. THE WIND CHILL ADVISORY FOR THE NORTHWEST HALF
REMAINS IN EFFECT.
UPDATE ISSUED AT 833 PM CST WED JAN 1 2014
ANOTHER ROW OF COUNTIES HAS BEEN DROPPED FROM THE NORTHERN EDGE OF
THE WINTER WEATHER ADVISORY AS THE AREA OF SNOW CONTINUES TO MOVE
SOUTHEAST.
UPDATE ISSUED AT 623 PM CST WED JAN 1 2014
TRENDS PER REGIONAL RADAR COMPOSITE SHOW THE BACK EDGE OF THE
ACCUMULATING SNOW FROM NEAR STERLING/ROCKFALLS THROUGH MOLINE AND
WASHINGTON IA AND MOVING STEADILY SOUTHEAST. THIS IS IN GOOD
AGREEMENT WITH THE 22Z RUN OF THE HRRR PRECIP FIELD. THE HRRR
SHOWS THE MEASURABLE SNOW CONTINUING TO PUSH STEADILY SOUTHEAST
THIS EVENING. WITH THESE TRENDS IN MIND THE PORTION OF THE WSW
THAT RAN UNTIL 6 PM WAS ALLOWED TO EXPIRE. SOME AREAS WHERE THE
WSW EXPIRED MAY SEE ANOTHER HOUR OR 2 OF LIGHT SNOW BUT ADDITIONAL
ACCUMULATIONS SHOULD BE WELL UNDER AN INCH. OTHERWISE NO CHANGES
WERE MADE TO THE REST OF THE FORECAST. WILL CONTINUE TO CHIP AWAY AT
THE NORTH EDGE OF THE REMAINING WINTER WX ADVISORY AS THE SNOW
CONTINUES TO MOVE SOUTHEAST.
&&
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 315 PM CST WED JAN 1 2014
WILL LEAVE ONGOING WINTER WX ADVISORIES GO WITH THE NORTHERN HALF
OF THE ADVISORY SECTION PROBABLY GETTING UP TO ANOTHER INCH
THROUGH 00Z...AND FRONTOGENESIS BAND OF SNOW JUST STARTING TO MAKE
IT ACRS THE SOUTHERN CWA AND THE SOUTHERN SECTION OF THE ADVISORY
WHICH GOES THROUGH 06Z TONIGHT. ALL IN ALL MOST SITES IN THE
ADVISORIES TO GET FROM 2-3 INCHES FROM 12Z THIS MORNING THOUGH
THIS EVENING...BUT BRISK NORTH TO NORTHEAST WINDS OF 10-20 MPH PRODUCING
DRIFTING OF POWDERY SNOW AND REDUCED VSBYS IN BOUTS OF HEAVIER
SNOW WITH FOG MAKING FOR HAZARDOUS TRAVEL SUPPORTING THE NEED OF
HEADLINES. PLUS STILL FEEL WITH UPTICK IN ELEVATED FRONTOGENETICAL
FORCING THIS EVENING...AREAS ALONG AND SOUTH OF A LINE FROM
FAIRFIELD IA TO NORTHEAST OF MONMOUTH WILL SEE AMOUNTS MORE IN THE
LINE OF 2-4 INCHES WITH SOME ISOLATED 5 INCH AMOUNTS POSSIBLE BY MIDNIGHT.
THEN AS NORTHEASTERLY SFC WINDS BACK TO THE NORTH...MORE OF A COLD
FETCH/CAA WILL OCCUR LATER TONIGHT AND MAKE FOR LOWS IN THE LOW
TO MID SINGLE DIGITS ABOVE ZERO EAST OF THE MS RVR INTO NORTHEASTERN
MO...AND SUBZERO LOWS GENERALLY ACRS THE NORTHWESTERN HALF OF THE
DVN CWA...-5 TO -10F IN DEEPER SNOWPACK AREAS AND RVR VALLEYS OF THE
NORTHWESTERN THIRD...AND WAPSI VALLEY TO THE MS RVR. COMBINED
WITH IN-BUILDING PRESSURE GRADIENT OFF NORTHERN PLAINS ARCTIC
RIDGE AND SUSTAINED 8-12 MPH WINDS...THESE TEMPS WILL PRODUCE WIND
CHILL ADVISORY CRITERIA FROM JUST AFTER MIDNIGHT THROUGH 11 AM CST OR
NOON THU FOR AREAS GENERALLY ALONG AND NORTHWEST OF A LINE FROM
STOCKTON IN FAR NW IL...TO TIPTON IA...AND TO FAIRFIELD IA. WILL
ISSUE THE WIND CHILL ADVISORY FOR THESE AREAS WITH THE POTENTIAL
TO EXPAND A TIER OF COUNTIES EASTWARD IF THE COLD SEEPAGE CREEPS
FURTHER TO THE EAST THAN CURRENTLY EXPECTED. CLOUDY TO MOSTLY
CLOUDY SKIES CONTINUE THROUGH TONIGHT,,,WITH THE POSSIBILITY OF
SOME NEWLY PRODUCED FLURRIES MOVING ACRS THE CWA FROM NORTH TO SOUTH
AFTER THE MAIN BAND OF SNOW SLIPS OFF TO THE SOUTHEAST.
ARCTIC HIGH BARRELS IT/S WAY ACRS IA INTO NORTHWESTERN IL AS DAY
PROGRESSES WITH ONGOING STOUT CAA. DESPITE THIS RIDGE CLEARING
THINGS OUT/EXCEPT MAYBE SOME BRIEF WDLY SCTRD INSTABILITY FLURRIES
OR SHOWERS/...TEMPS WILL HAVE A HARD TIME RECOVERING MUCH FROM
MORNING LOWS...SINGLE DIGITS ABOVE ZERO EXCEPT THE FAR EAST AND
SOUTHEAST WHICH MAY HIT +10 OR A FEW DEGREES WARMER. ..12..
.LONG TERM...(THURSDAY NIGHT THROUGH NEXT WEDNESDAY)
ISSUED AT 315 PM CST WED JAN 1 2014
THE MAIN FORECAST THIS PERIOD WILL BE TEMPERATURES THROUGH THE
PERIOD. MODELS ARE IN GOOD OVERALL AGREEMENT WITH THE LARGE SCALE
PATTERN BUT THERE IS SOME DISAGREEMENT IN THE TIMING AND PLACEMENT
OF FEATURES BY THIS WEEKEND.
THE CURRENT ACTIVE WEATHER REGIME IS FORECAST TO CONTINUE INTO AT
LEAST EARLY NEXT WEEK AS SEVERAL REINFORCING SHOTS OF COLD AIR DROP
INTO THE GREAT PLAINS. SHORTWAVE RIDGING WILL BUILD INTO THE REGION
BY THURSDAY NIGHT INTO FRIDAY MORNING WITH SKIES CLEARING
OVERNIGHT. 850 TEMPERATURES OF -15*C TO -20*C ACROSS THE REGION
WILL LEAD TO POTENTIAL NEAR RECORD LOWS ON FRIDAY MORNING. PLEASE
SEE THE CLIMATE SECTION BELOW.
HIGH PRESSURE WILL SHIFT EASTWARD ON FRIDAY MORNING ALLOWING FOR
WINDS TO VEER TO THE SOUTH AND BEGIN WARM ADVECTING INTO THE REGION ON
FRIDAY AND SATURDAY AHEAD OF THE NEXT ALBERTA CLIPPER. A TIGHTENING
PRESSURE GRADIENT ON FRIDAY WILL LEAD TO BREEZY CONDITIONS INTO
SATURDAY. SATURDAY WILL BE THE WARMEST DAY OF THE PERIOD WITH
TEMPERATURES CLOSER TO NORMALS IN THE UPPER 20S TO LOWER 30S.
CLOUDS WILL BEGIN OVERSPREADING THE REGION ON SATURDAY AHEAD OF A
CLIPPER THAT WILL DRAG A STRONG COLD FRONT ACROSS THE REGION
SATURDAY AFTERNOON INTO THE EVENING. THE BETTER DYNAMICS AND
MOISTURE WITH THIS SYSTEM WILL BE ALONG AND BEHIND THE FRONT. THE
GFS IS QUICKER WITH THE SYSTEM AND ENDS PRECIPITATION BY 06 UTC ON
SUNDAY WHILE THE ECMWF IS WETTER AND CONTINUES THE PRECIPITATION
THROUGH 18 UTC ON SUNDAY. HAVE A COMBINATION OF THE TWO SOLUTIONS
GOING INTO SUNDAY WITH SOME LINGERING SNOW THROUGH 18 UTC.
VERY STRONG COLD ADVECTION WILL BE ONGOING SUNDAY NIGHT INTO MONDAY
WITH A STRONG 1040 TO 1050 MB SURFACE HIGH BUILDING SOUTHEASTWARD
INTO MONTANA. THE GFS AND ECMWF SHOW THE SURFACE HIGH MODERATING TO
BETWEEN 1030 TO 1040 MB BY TUESDAY MORNING ACROSS IOWA. 850
TEMPERATURES WILL HAVE COOLED TO -20*C TO -30*C BY 12 UTC ON MONDAY
AND FURTHER COOLING TO -24*C TO -30*C BY 12 UTC ON TUESDAY. THESE
TEMPERATURES ARE 2 TO 3 STANDARD DEVIATIONS BELOW THE MEAN FOR
JANUARY SO THIS WILL BE AN UNUSUALLY COLD AIRMASS BUILDING INTO THE
REGION EARLY NEXT WEEK. SURFACE TEMPERATURES MAY REMAIN BELOW ZERO
SUNDAY NIGHT THROUGH TUESDAY. SOME OF THIS COLD AIR MAY BE HIGHLY
DEPENDENT ON THE SNOWPACK TO OUR NORTH. AFTER TUESDAY...HIGH
PRESSURE WILL SHIFT EASTWARD ALLOWING FOR A RETURN TO MORE MODERATE
AIR FOR THE MIDDLE OF NEXT WEEK. IN ADDITION TO THE COLD AIR THE
PRESSURE GRADIENT WILL BE TIGHT ACROSS THE REGION ON MONDAY SO
ANOTHER BREEZY OVERNIGHT WHICH WILL MAKE TEMPERATURES FEEL MUCH
COLDER THAN THE AIR. COUSINS
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1144 PM CST WED JAN 1 2014
MOIST NORTHERLY LOW LEVEL FLOW WILL BE VFR CIGS IN THE 4 TO 6KFT
RANGE INTO THURSDAY MORNING. THERE WILL BE SOME PATCHY MVFR CIGS
AROUND 2 KFT ESPECIALLY NEAR THE MISSISSIPPI RIVER OVER NIGHT.
VFR CONDITIONS ARE EXPECTED FOR MOST OF THURSDAY AFTERNOON AND
EVENING WITH CLEARING SKIES EXPECTED.
&&
.CLIMATE...
ISSUED AT 315 PM CST WED JAN 1 2014
RECORD LOWS FOR JANUARY 2...
MOLINE.........-27 IN 1979
CEDAR RAPIDS...-19 IN 1979
DUBUQUE........-22 IN 1879
BURLINGTON.....-15 IN 1979
RECORD LOWS FOR JANUARY 3...
MOLINE.........-16 IN 1887
CEDAR RAPIDS...-15 IN 1919
DUBUQUE........-24 IN 1887
BURLINGTON.....-16 IN 1919
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR BENTON-BUCHANAN-
CEDAR-CLINTON-DELAWARE-DUBUQUE-IOWA-JACKSON-JEFFERSON-
JOHNSON-JONES-KEOKUK-LINN-WASHINGTON.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR LEE.
IL...WIND CHILL ADVISORY UNTIL NOON CST THURSDAY FOR JO DAVIESS.
WINTER WEATHER ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR HANCOCK-
MCDONOUGH.
MO...NONE.
&&
$$
UPDATE...DLF
SHORT TERM...12
LONG TERM...COUSINS
AVIATION...DLF
CLIMATE...COUSINS
AREA FORECAST DISCUSSION
NWS PADUCAH KY
350 AM CST Thu Jan 2 2014
.SHORT TERM /TODAY THROUGH SATURDAY/...
ISSUED AT 350 AM CST THU JAN 2 2014
In the near term...the minor snow event appears to be on track to
occur in the next several hours. The rain/snow line was located
roughly from Mt. Carmel to Marion IL...southwest to Poplar Bluff
MO at 09z. This transition line will move southeast across all but
the khop area by around 13z. Radar indicates a swath of steady
snow /20 to 25 dbz echoes/ from just se of kstl to kuno as of 09z.
Based on HRRR simulated reflectivity and RAP 1000/500 mb mean
rh fields...this area of steadier snow is likely to lift
east/northeast across the existing winter weather advisory area
this morning. Forecast snowfall amounts appear on track...though
they have been tweaked slightly downward in some areas. Any two
inch amounts would be rather isolated.
Forecast model soundings indicate a very well mixed boundary layer
this afternoon as the arctic air mass settles in. This may
translate to considerable cold air stratocu and flurries. Gusty
winds are also anticipated...with bufkit momentum transfer
algorithm suggesting gusts around 30 mph. Guidance is in
agreement that temperatures will remain steady in the 20s this
afternoon.
The remainder of the forecast is dry...so the main issue is temps.
A 1035 mb surface high will be centered almost directly over the
kstl area at 12z Friday. With clear skies and light
winds...conditions would suggest low temps near zero over snow
cover. The main concern is where the significant snow cover will
exist. Will tweak lows further downward over anticipated snow
cover along and northwest of a line from kmdh to the Wabash
Valley. Elsewhere...model guidance appears reasonable.
Southerly return flow will develop on the back side of the high
Friday. Due to the cold start to the day...highs will still not
reach freezing despite abundant sunshine. Increasing southwest
low level flow Friday night and Saturday will eventually bring
temps close to climo ahead of the next arctic front.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 350 AM CST THU JAN 2 2014
The good news is that the medium range models are in very good
agreement throughout this extended forecast period. The bad news is
that they are advertising what could be a significant winter storm
over much of the area Saturday night and Sunday, followed by an
Arctic outbreak of an insane magnitude. Much of the area could see
some of the coldest air ever recorded, and that includes Evansville
with its longer period of record.
By 12Z Monday morning, the 00Z ECWMF and GFS have a 4950M 500mb low
near the east side of Lake Superior with an intense trough running
from the east slope of the Rockies through the northern Gulf Coast
States and then up the entire east coast. This will bring 850mb
temperatures in the -20F to -30F range to our region, which will
likely lead to surface temperatures that do not climb above zero in
the north Monday. The coldest high temperature ever recorded for any
day at Evansville has been -3F, so all time records will be in
jeopardy. The other concern is that winds will not be light, so wind
chills will be -10F to -20F for portions if not all of the area
Sunday night into Tuesday.
As the flow aloft begins to amplify, the models bring a lead
short-wave trough eastward through the area with a significant
surface system Saturday night through Sunday. QPF with this system
is near three quarters of an inch, and portions of southeast
Missouri, southern Illinois and possibly southwest Indiana may see
most of that as snow. Of course it will depend on the location, and
movement of the surface freezing line, which the ECMWF and GEM try
to hold up over west Kentucky and southwest Indiana well into
Sunday. The GFS is a bit faster with the entire system, and is most
agressive with the cold air. The potential exists for significant
accumulations of snow over much of the area. And with the Arctic
surge occurring late Sunday and Sunday night, any ice or snow will
be difficult to remove.
The combination of the initial winter storm and the eventual Arctic
airmass could snarl the region for much of next week. Will not issue
a Special Weather Statement for this extreme winter weather outbreak
at this time due to the ongoing Winter Weather Advisory event.
However, would expect one from the day shift after this morning`s
system has passed.
Some moderation will occur heading into Wednesday of next week,
according to the GFS and ECMWF, but warm advection on the back side
of the departing Arctic surface high will result in a good chance of
wintry precipitation. Added small pops for most of the area
Wednesday, and good chances for Wednesday night. This will be more
of a warm frontal evolution with snow becoming sleet and then
possibly rain/freezing rain through the event. For now just kept it
as a snow/sleet mix given the extremely cold airmass the system will
have to erode. The models keep southwest flow aloft through the end
of the week and there does not seem to be any fresh cold airmass to
move into the region, so the cold spell should be over by the end of
next week.
&&
.AVIATION...
ISSUED AT 350 AM CST THU JAN 2 2014
Strong cold front roughly along a KEVV to KPAH line at 09z will
sweep southeast...quickly followed by northwest winds gusting to
30 knots. Areas of ifr cigs behind the front appear rather
localized and should not persist more than a couple hours. By
late this morning...mvfr cigs are anticipated at all sites. A
period of snow early this morning will result in mvfr vsbys for a
few hours...with some brief ifr vsbys possible in kevv/kowb area.
Otherwise...vfr vsbys are expected through the period. Clearing
skies and diminishing winds are expected tonight as high pressure
builds into the Mississippi Valley.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
KY...WINTER WEATHER ADVISORY until Noon CST today FOR KYZ014-018-019.
MO...WINTER WEATHER ADVISORY until 8 AM CST this morning FOR MOZ076.
IL...WINTER WEATHER ADVISORY until 8 AM CST this morning FOR ILZ075-
076-080>087.
WINTER WEATHER ADVISORY until Noon CST today FOR ILZ077-078.
IN...WINTER WEATHER ADVISORY until Noon CST today FOR INZ081-082-
085>088.
&&
$$
SHORT TERM...MY
LONG TERM....DRS
AVIATION...MY
AREA FORECAST DISCUSSION
NWS BUFFALO NY
141 AM EST THU JAN 2 2014
.SYNOPSIS...
A BITTERLY COLD AIRMASS WILL DROP ACROSS THE REGION TONIGHT AND
LINGER THROUGH FRIDAY. A WIDESPREAD AND PROLONGED SNOW EVENT WILL
DEVELOP TONIGHT THROUGH EARLY FRIDAY...ONE THAT WILL BRING
ACCUMULATING SNOWS HEAVIEST TO THE GENESEE VALLEY AND NORTHERN
FINGER LAKES REGION. A NORTHEAST WIND WILL LOWER WIND CHILLS TO
DANGEROUS LEVELS...ESPECIALLY ACROSS THE NORTH COUNTRY WHERE BRUTAL
WIND CHILLS WILL DEVELOP TONIGHT AND TOMORROW NIGHT. A WARMING TREND
IS EXPECTED FOR THE COMING WEEKEND.
&&
.NEAR TERM /THROUGH TODAY/...
LATEST REGIONAL RADAR IMAGERY IS SHOWING CONSOLIDATION OF THE WARM
FRONTAL SNOW BAND ACROSS THE NIAGARA FRONTIER LATE THIS EVENING EVEN
AS THE SNOW IS TEMPORARILY TAPERING OFF ACROSS THE SOUTHERN TIER.
THE CULPRIT THERE IS LIKELY A DRY SLOT INDUCED BY WEAK SUBSIDENCE
ALOFT...HOWEVER SATELLITE OBS INDICATE ANOTHER SHOT OF MOISTURE
LURKING UPSTREAM ACROSS WESTERN LAKE ERIE THAT SHOULD BRING SNOW
BACK INTO THE WESTERN SOUTHERN TIER A LITTLE AFTER MIDNIGHT...AS
SUPPORTED BY THE LATEST HRRR GUIDANCE.
WITH DEEPENING MOISTURE ACROSS THE REGION...EXPECT LIGHT SNOW TO
PERSIST OVERNIGHT AS A MID-LEVEL CYCLONE MOVES INTO THE OHIO VALLEY
AND IT/S ASSOCIATED WARM FRONTAL BAND REMAINS NEARLY STATIONARY
ACROSS WESTERN/CENTRAL NEW YORK. SNOWFALL RATES GENERALLY IN THE
NEIGHBORHOOD OF A A QUARTER TO A FEW TENTHS PER HOUR SHOULD RESULT
IN A GENERAL 1 TO 3 INCHES ACROSS THE BULK OF THE FORECAST AREA WITH
THE EXCEPTION OF THE NORTH COUNTRY WHERE THE FRONTAL BAND IS NOT
EXPECTED TO ARRIVE UNTIL NEAR DAYBREAK.
THE AFOREMENTIONED WARM FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS
THE FORECAST AREA THROUGHOUT THE DAY ON THURSDAY AS LOW PRESSURE
SLIDES BY TO OUR SOUTH ACROSS PENNSYLVANIA. THIS WILL ALLOW FOR
LIGHT SNOW TO PERSIST ACROSS THE REGION THROUGHOUT THE
DAY...RESULTING IN WIDESPREAD ACCUMULATIONS IN THE 2 TO 4 INCH RANGE
WITH AS MUCH AS SIX INCHES POSSIBLE ACROSS THE HIGHER TERRAIN OF THE
FINGER LAKES AND ALLEGANY COUNTY...CLOSER TO THE EXPECTED LOCATION
OF THE TIGHTEST THERMAL GRADIENT ALOFT. AS THE LOW PASSES TO OUR
SOUTH...NORTHEASTERLY WINDS WILL STRENGTHEN INTO THE 15 TO 20 MPH
RANGE WITH GUSTS AS HIGH AS 35 MPH POSSIBLE NEAR THE LAKE ONTARIO
SHORELINE. THIS WILL RESULT IN THE ADDED DIFFICULTY OF
BLOWING/DRIFTING SNOW...PARTICULARLY TOWARDS LAKE ONTARIO. IN
ADDITION...THE INCREASING WINDS COUPLED WITH INCREASING COLD
ADVECTION THAT WILL KEEP AFTERNOON HIGHS DEPRESSED INTO THE LOW
TEENS TO SINGLE DIGITS WILL PRODUCE DANGEROUS WIND CHILLS IN THAT
COULD DIP AS LOW AS 10 BELOW ZERO AND AS MUCH AS 25 BELOW ZERO
ACROSS THE NORTH COUNTRY.
&&
.SHORT TERM /TONIGHT THROUGH FRIDAY NIGHT/...
THURSDAY EVENING WILL START OFF WITH A MID LEVEL FRONTAL BOUNDARY
ACROSS SOUTHERN NEW YORK. MEANWHILE A SHARP 500 MB TROF APPROACHING
FROM THE UPPER LAKES WILL ENERGIZE A COASTAL LOW FORECAST TO DEVELOP
OFF THE MID ATLANTIC COAST. THE APPROACHING TROF WILL HELP ENHANCE
LIFT...HOWEVER THE FRONTAL BOUNDARY WILL SLIDE SOUTHEAST AT IT GETS
WRAPPED UP IN THE DEVELOPING COASTAL LOW. SYNOPTIC SCALE LIFT WITH
THE UPPER TROF ALONE WILL BE FAIRLY MODEST...WITH MOST LOWER
RESOLUTION GUIDANCE FORECASTING ONLY A TENTH OF AN INCH OF QPF FOR
THURSDAY NIGHT. HOWEVER...A DEEPENING NORTHEAST SURFACE FLOW WILL
LIKELY RESULT IN SOME LAKE ENHANCEMENT. THE NORTHEAST FLOW WOULD
FAVOR AREAS ALONG THE SOUTH SHORE OF LAKE ONTARIO...ESPECIALLY
MONROE AND WAYNE COUNTIES WHERE THERE WILL BE A LONGER FETCH AND A
BIT MORE SYNOPTIC MOISTURE. OFF LAKE ERIE SOME ENHANCEMENT IS
POSSIBLE IN CHAUTAUQUA COUNTY. ALSO...COLDER AIR WITH THE UPPER TROF
WILL PLACE THE BEST LIFT IN A MORE FAVORABLE TEMPERATURE FOR
DENDRITIC CRYSTAL GROWTH. 06Z/12Z RUNS OF THE NAM SUGGEST AMPLE
MOISTURE IN THIS LAYER THROUGH THURSDAY NIGHT...WITH A TEMPORARY
INCREASE IN FLUFF FACTOR LIKELY.
MEANWHILE...WIND CHILLS WILL DROP WELL BELOW ZERO ON THURSDAY NIGHT
AND LAST INTO FRIDAY MORNING. THIS WILL BE DUE TO A BRISK 10 TO 20
MPH NNE FLOW. EVEN WITH LITTLE RADIATIONAL COOLING...OVERNIGHT
TEMPERATURES WILL EASILY DROP TO NEAR ZERO IN MOST LOCATIONS...WITH
10 TO 15 BELOW LIKELY ACROSS THE NORTH COUNTRY. THIS WILL RESULT IN
BITTERLY COLD WIND CHILLS DOWN TO 20 BELOW SOUTH OF LAKE
ONTARIO...AND 30 BELOW ACROSS THE NORTH COUNTRY.
THE COMBINATION OF COLD TEMPERATURES...WIND...AND SNOW WILL HAVE A
SIGNIFICANT IMPACT ON TRAVEL...ESPECIALLY ACROSS EASTERN PORTIONS OF
THE CWA. VERY COLD TEMPERATURES WILL MAKE IT DIFFICULT FOR SALT TO
WORK ON ROADS... LEADING TO DIFFICULT AND VERY SLIPPERY TRAVEL.
THE TROF WILL MOVE EAST OF THE REGION FRIDAY...ALLOWING SURFACE HIGH
PRESSURE TO BUILD IN FROM THE WEST. THIS WILL BRING IN PROGRESSIVELY
DRIER AIR WITH ONLY A SHALLOW LAYER OF MOISTURE. 850MB TEMPERATURES
BELOW -20C WILL LIKELY BE TOO COLD FOR DENDRITES...WITH THE
RESULTING LAKE EFFECT SNOW LIKELY TO HAVE POOR SNOW TO WATER RATIOS.
THESE FACTORS SHOULD LEAD TO GENERALLY LIGHT ADDITIONAL ACCUMULATION
ON FRIDAY. TEMPERATURES WILL ONLY REBOUND SOME...WITH HIGHS IN THE
SINGLE DIGITS SOUTH OF LAKE ONTARIO...AND BELOW ZERO ACROSS THE
NORTH COUNTRY.
ON FRIDAY NIGHT...ANY LINGERING LAKE SNOWS WILL END AS HIGH PRESSURE
CRESTS ACROSS THE REGION. THIS WILL LIKELY BRING THE COLDEST
NON-WIND CHILL TEMPERATURES...WITH LOWS OF MINUS 20 A GOOD
POSSIBILITY IN THE NORTH COUNTRY AND ZERO TO 5 BELOW ELSEWHERE.
SOUTHERLY WINDS WILL PICK UP OVERNIGHT...WHICH WILL LIMIT
RADIATIONAL COOLING AND EVENTUALLY CAUSE TEMPERATURES TO RISE
OVERNIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL SLIDE TO THE EAST OF THE REGION ON SATURDAY...
BRINGING FAIR WEATHER AND WARMER TEMPERATURES TO WESTERN NEW YORK
FOR SATURDAY. A COLD FRONT WILL APPROACH FROM THE WEST ON
SATURDAY...WITH A CHANCE OF SNOW SHOWERS...ESPECIALLY TO THE WEST.
THINGS GET A BIT MORE INTERESTING IN THE SUNDAY AND MONDAY
TIMEFRAME. THERE HAS BEEN A WIDE SPREAD IN MODEL SOLUTIONS...WITH
12Z RUNS OF GFS/GGEM/ECMWF COMING INTO A BIT BETTER AGREEMENT. ALL
THREE NOW FORECAST A SIGNIFICANT WAVE OF LOW PRESSURE RIDING ALONG
THE FRONTAL BOUNDARY. THE GFS IS STILL THE WEAKEST AND
COLDEST...WITH THE ECMWF STRONGEST AND WARM ENOUGH O CHANGE
PRECIPITATION TO RAIN EAST OF ROCHESTER. TAKING A CONSENSUS...EXPECT
SNOW IS THE MORE LIKELY FORM OF PRECIPITATION...WITH THE BEST CHANCE
FOR IT STILL COMING SUNDAY NIGHT INTO MONDAY. DEPENDING ON THE
STRENGTH AND TRACK OF THE LOW...SNOW ACCUMULATIONS COULD BE
SIGNIFICANT. IT IS STILL TOO EARLY TO DETERMINE SPECIFICS...WITH
PLENTY OF OPPORTUNITY FOR FUTURE SHIFTS IN MODEL GUIDANCE.
AFTER THIS...THERE IS GOOD MODEL AGREEMENT THAT ANOTHER SHOT OF VERY
COULD AIR WILL BUILD IN BEHIND WHATEVER LOW DOES DEVELOP. EXPECT
BELOW NORMAL TEMPERATURES AND FAIRLY WINDY CONDITIONS TUESDAY AND
WEDNESDAY. THIS ALSO IS LIKELY TO BRING MORE LAKE EFFECT SNOWS EAST
AND POSSIBLY NORTHEAST OF THE LAKES.
&&
.AVIATION /07Z THURSDAY THROUGH MONDAY/...
REGIONAL RADAR CURRENTLY SHOWS A BAND OF LIGHT SNOW CONSOLIDATING
ACROSS THE NIAGARA FRONTIER AND EXTENDING EAST ALONG/NORTH OF THE NYS
THRUWAY. VSBYS WITHIN THIS BAND..THAT ENCOMPASSES
KBUF/KIAG/KROC...WILL REMAIN IFR WITH MVFR CIGS EXPECTED FOR MUCH OF
THE NIGHT AS THE BAND WILL REMAIN NEARLY STATIONARY. MEANWHILE...A
DRY SLOT HAS MOVED OVER THE WESTERN SOUTHERN TIER...BRINGING A BREAK
IN THE SNOWFALL. MESOSCALE MODEL GUIDANCE INDICATES THAT THIS BREAK
AT KJHW MAY LAST AS LATE AS 06-07Z BEFORE ANOTHER SHOT OF MOISTURE
BRINGS LIGHT SNOW BACK ACROSS THE TERMINAL.
MEANWHILE...KART IS STILL VFR AND SHOULD REMAIN SO UNTIL 11Z WHEN
THE BAND PIVOTS NORTHWARDS INTO THE NORTH COUNTRY...BRINGING
MVFR/IFR CONDITIONS. THESE CONDITIONS ARE EXPECTED TO PERSIST FOR
THE BALANCE OF THE TAF PERIOD.
IN ADDITION TO REDUCED VSBYS/CIGS DUE TO THE PRESENCE OF LIGHT
SNOW...FURTHER REDUCTIONS IN VSBYS WILL BE POSSIBLE DURING THE DAY
ON FRIDAY AS NORTHEASTERLY WINDS WILL INCREASE INTO THE 20KT
RANGE...MAKING BLOWING SNOW AN ISSUE ACROSS THE FORECAST AREA.
OUTLOOK...
THURSDAY AND THURSDAY NIGHT...IFR/MVFR WITH SNOW LIKELY.
FRIDAY...IFR/MVFR IN LAKE EFFECT SNOW SHOWERS SOUTHEAST OF THE
LAKES. OTHERWISE MAINLY VFR.
SATURDAY...VFR.
SATURDAY NIGHT AND SUNDAY...MVFR/IFR IN SNOW SHOWERS.
MONDAY...MVFR IN A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
NORTHEASTERLY WINDS WILL FRESHEN TONIGHT AND THURSDAY AND BRING
SMALL CRAFT ADVISORY LEVEL CONDITIONS TO THE LAKES AS WELL AS THE
LOWER NIAGARA RIVER AS LOW PRESSURE APPROACHES THE REGION FROM THE
LOWER OHIO VALLEY. THESE WINDS WILL CONTINUE TO STRENGTHEN THURSDAY
AS THE LOW SLIDES BY TO OUR SOUTH ACROSS PENNSYLVANIA AND EVEN
COLDER AIR WRAPS IN BEHIND THIS LOW. THIS COLD ADVECTION WILL AID IN
KEEPING CONDITIONS ROUGH ON THE LAKES INTO FRIDAY MORNING BEFORE
HIGH PRESSURE MOVES ACROSS THE REGION LATER IN THE DAY...BRINGING A
BRIEF RESPITE BEFORE SOUTHWESTERLIES THEN FRESHEN SATURDAY AS
ANOTHER LOW PRESSURE SYSTEM APPROACHES THE REGION...THIS TIME FROM
NORTHERN ONTARIO. HEAVY FREEZING SPRAY IS LIKELY GIVEN THE
CONDITIONS ON VERY COLD TEMPERATURES...STRONG WINDS AND HIGH
WAVES. A FREEZING SPRAY WARNING WILL REMAIN IN EFFECT THROUGH MID
DAY ON FRIDAY FOR NEARSHORE AND OPEN WATERS OF LAKE ONTARIO AND
NEARSHORE WATERS OF LAKE ERIE.
&&
.CLIMATE...
VERY COLD AIR IS ON THE WAY FOR THE REGION THIS WEEK...WITH THE
COLD AIR PEAKING THURSDAY AND FRIDAY. HIGH TEMPERATURES ON FRIDAY
WILL LIKELY NOT GET OUT OF THE SINGLE NUMBERS ACROSS THE ENTIRE
REGION...AND NOT ABOVE ZERO EAST OF LAKE ONTARIO.
THE LAST TIME BUFFALO DID NOT GET TO 10 DEGREES FOR A DAYTIME HIGH
WAS 1/16/09...AND FOR ROCHESTER 3/6/07. AT WATERTOWN THE LAST TIME
THE HIGH DID NOT GET ABOVE ZERO WAS 1/22/2005.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR NYZ001-002-
006-010>012-019-020-085.
WIND CHILL ADVISORY FROM 4 PM THIS AFTERNOON TO NOON EST
FRIDAY FOR NYZ001>006-010>014-019>021-085.
WIND CHILL WARNING FROM 4 PM THIS AFTERNOON TO NOON EST FRIDAY
FOR NYZ007-008.
WIND CHILL ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR NYZ007-
008.
WINTER STORM WARNING UNTIL 6 AM EST FRIDAY FOR NYZ003>005-013-
014-021.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR LEZ040-041.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST FRIDAY FOR
LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR LOZ030.
HEAVY FREEZING SPRAY WARNING UNTIL 1 PM EST FRIDAY FOR
LOZ042>045-062>065.
SMALL CRAFT ADVISORY UNTIL 10 AM EST FRIDAY FOR LOZ042>045.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...WOOD
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...WOOD
MARINE...THOMAS/WCH/WOOD
CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1139 PM EST WED JAN 1 2014
.SYNOPSIS...
A BITTERLY COLD AIRMASS WILL DROP ACROSS THE REGION TONIGHT AND
LINGER THROUGH FRIDAY. A WIDESPREAD AND PROLONGED SNOW EVENT WILL
DEVELOP TONIGHT THROUGH EARLY FRIDAY...ONE THAT WILL BRING
ACCUMULATING SNOWS HEAVIEST TO THE GENESEE VALLEY AND NORTHERN
FINGER LAKES REGION. A NORTHEAST WIND WILL LOWER WIND CHILLS TO
DANGEROUS LEVELS...ESPECIALLY ACROSS THE NORTH COUNTRY WHERE BRUTAL
WIND CHILLS WILL DEVELOP TONIGHT AND TOMORROW NIGHT. A WARMING TREND
IS EXPECTED FOR THE COMING WEEKEND.
&&
.NEAR TERM /THROUGH THURSDAY/...
LATEST REGIONAL RADAR IMAGERY IS SHOWING CONSOLIDATION OF THE WARM
FRONTAL SNOW BAND ACROSS THE NIAGARA FRONTIER LATE THIS EVENING EVEN
AS THE SNOW IS TEMPORARILY TAPERING OFF ACROSS THE SOUTHERN TIER.
THE CULPRIT THERE IS LIKELY A DRY SLOT INDUCED BY WEAK SUBSIDENCE
ALOFT...HOWEVER SATELLITE OBS INDICATE ANOTHER SHOT OF MOISTURE
LURKING UPSTREAM ACROSS WESTERN LAKE ERIE THAT SHOULD BRING SNOW
BACK INTO THE WESTERN SOUTHERN TIER A LITTLE AFTER MIDNIGHT...AS
SUPPORTED BY THE LATEST HRRR GUIDANCE.
WITH DEEPENING MOISTURE ACROSS THE REGION...EXPECT LIGHT SNOW TO
PERSIST OVERNIGHT AS A MID-LEVEL CYCLONE MOVES INTO THE OHIO VALLEY
AND IT/S ASSOCIATED WARM FRONTAL BAND REMAINS NEARLY STATIONARY
ACROSS WESTERN/CENTRAL NEW YORK. SNOWFALL RATES GENERALLY IN THE
NEIGHBORHOOD OF A A QUARTER TO A FEW TENTHS PER HOUR SHOULD RESULT
IN A GENERAL 1 TO 3 INCHES ACROSS THE BULK OF THE FORECAST AREA WITH
THE EXCEPTION OF THE NORTH COUNTRY WHERE THE FRONTAL BAND IS NOT
EXPECTED TO ARRIVE UNTIL NEAR DAYBREAK.
THE AFOREMENTIONED WARM FRONTAL BOUNDARY WILL REMAIN STALLED ACROSS
THE FORECAST AREA THROUGHOUT THE DAY ON THURSDAY AS LOW PRESSURE
SLIDES BY TO OUR SOUTH ACROSS PENNSYLVANIA. THIS WILL ALLOW FOR
LIGHT SNOW TO PERSIST ACROSS THE REGION THROUGHOUT THE
DAY...RESULTING IN WIDESPREAD ACCUMULATIONS IN THE 2 TO 4 INCH RANGE
WITH AS MUCH AS SIX INCHES POSSIBLE ACROSS THE HIGHER TERRAIN OF THE
FINGER LAKES AND ALLEGANY COUNTY...CLOSER TO THE EXPECTED LOCATION
OF THE TIGHTEST THERMAL GRADIENT ALOFT. AS THE LOW PASSES TO OUR
SOUTH...NORTHEASTERLY WINDS WILL STRENGTHEN INTO THE 15 TO 20 MPH
RANGE WITH GUSTS AS HIGH AS 35 MPH POSSIBLE NEAR THE LAKE ONTARIO
SHORELINE. THIS WILL RESULT IN THE ADDED DIFFICULTY OF
BLOWING/DRIFTING SNOW...PARTICULARLY TOWARDS LAKE ONTARIO. IN
ADDITION...THE INCREASING WINDS COUPLED WITH INCREASING COLD
ADVECTION THAT WILL KEEP AFTERNOON HIGHS DEPRESSED INTO THE LOW
TEENS TO SINGLE DIGITS WILL PRODUCE DANGEROUS WIND CHILLS IN THAT
COULD DIP AS LOW AS 10 BELOW ZERO AND AS MUCH AS 25 BELOW ZERO
ACROSS THE NORTH COUNTRY.
&&
.SHORT TERM /THURSDAY NIGHT THROUGH FRIDAY NIGHT/...
THURSDAY EVENING WILL START OFF WITH A MID LEVEL FRONTAL BOUNDARY
ACROSS SOUTHERN NEW YORK. MEANWHILE A SHARP 500 MB TROF APPROACHING
FROM THE UPPER LAKES WILL ENERGIZE A COASTAL LOW FORECAST TO DEVELOP
OFF THE MID ATLANTIC COAST. THE APPROACHING TROF WILL HELP ENHANCE
LIFT...HOWEVER THE FRONTAL BOUNDARY WILL SLIDE SOUTHEAST AT IT GETS
WRAPPED UP IN THE DEVELOPING COASTAL LOW. SYNOPTIC SCALE LIFT WITH
THE UPPER TROF ALONE WILL BE FAIRLY MODEST...WITH MOST LOWER
RESOLUTION GUIDANCE FORECASTING ONLY A TENTH OF AN INCH OF QPF FOR
THURSDAY NIGHT. HOWEVER...A DEEPENING NORTHEAST SURFACE FLOW WILL
LIKELY RESULT IN SOME LAKE ENHANCEMENT. THE NORTHEAST FLOW WOULD
FAVOR AREAS ALONG THE SOUTH SHORE OF LAKE ONTARIO...ESPECIALLY
MONROE AND WAYNE COUNTIES WHERE THERE WILL BE A LONGER FETCH AND A
BIT MORE SYNOPTIC MOISTURE. OFF LAKE ERIE SOME ENHANCEMENT IS
POSSIBLE IN CHAUTAUQUA COUNTY. ALSO...COLDER AIR WITH THE UPPER TROF
WILL PLACE THE BEST LIFT IN A MORE FAVORABLE TEMPERATURE FOR
DENDRITIC CRYSTAL GROWTH. 06Z/12Z RUNS OF THE NAM SUGGEST AMPLE
MOISTURE IN THIS LAYER THROUGH THURSDAY NIGHT...WITH A TEMPORARY
INCREASE IN FLUFF FACTOR LIKELY.
MEANWHILE...WIND CHILLS WILL DROP WELL BELOW ZERO ON THURSDAY NIGHT
AND LAST INTO FRIDAY MORNING. THIS WILL BE DUE TO A BRISK 10 TO 20
MPH NNE FLOW. EVEN WITH LITTLE RADIATIONAL COOLING...OVERNIGHT
TEMPERATURES WILL EASILY DROP TO NEAR ZERO IN MOST LOCATIONS...WITH
10 TO 15 BELOW LIKELY ACROSS THE NORTH COUNTRY. THIS WILL RESULT IN
BITTERLY COLD WIND CHILLS DOWN TO 20 BELOW SOUTH OF LAKE
ONTARIO...AND 30 BELOW ACROSS THE NORTH COUNTRY.
THE COMBINATION OF COLD TEMPERATURES...WIND...AND SNOW WILL HAVE A
SIGNIFICANT IMPACT ON TRAVEL...ESPECIALLY ACROSS EASTERN PORTIONS OF
THE CWA. VERY COLD TEMPERATURES WILL MAKE IT DIFFICULT FOR SALT TO
WORK ON ROADS... LEADING TO DIFFICULT AND VERY SLIPPERY TRAVEL.
THE TROF WILL MOVE EAST OF THE REGION FRIDAY...ALLOWING SURFACE HIGH
PRESSURE TO BUILD IN FROM THE WEST. THIS WILL BRING IN PROGRESSIVELY
DRIER AIR WITH ONLY A SHALLOW LAYER OF MOISTURE. 850MB TEMPERATURES
BELOW -20C WILL LIKELY BE TOO COLD FOR DENDRITES...WITH THE
RESULTING LAKE EFFECT SNOW LIKELY TO HAVE POOR SNOW TO WATER RATIOS.
THESE FACTORS SHOULD LEAD TO GENERALLY LIGHT ADDITIONAL ACCUMULATION
ON FRIDAY. TEMPERATURES WILL ONLY REBOUND SOME...WITH HIGHS IN THE
SINGLE DIGITS SOUTH OF LAKE ONTARIO...AND BELOW ZERO ACROSS THE
NORTH COUNTRY.
ON FRIDAY NIGHT...ANY LINGERING LAKE SNOWS WILL END AS HIGH PRESSURE
CRESTS ACROSS THE REGION. THIS WILL LIKELY BRING THE COLDEST
NON-WIND CHILL TEMPERATURES...WITH LOWS OF MINUS 20 A GOOD
POSSIBILITY IN THE NORTH COUNTRY AND ZERO TO 5 BELOW ELSEWHERE.
SOUTHERLY WINDS WILL PICK UP OVERNIGHT...WHICH WILL LIMIT
RADIATIONAL COOLING AND EVENTUALLY CAUSE TEMPERATURES TO RISE
OVERNIGHT.
&&
.LONG TERM /SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE WILL SLIDE TO THE EAST OF THE REGION ON SATURDAY...
BRINGING FAIR WEATHER AND WARMER TEMPERATURES TO WESTERN NEW YORK
FOR SATURDAY. A COLD FRONT WILL APPROACH FROM THE WEST ON
SATURDAY...WITH A CHANCE OF SNOW SHOWERS...ESPECIALLY TO THE WEST.
THINGS GET A BIT MORE INTERESTING IN THE SUNDAY AND MONDAY
TIMEFRAME. THERE HAS BEEN A WIDE SPREAD IN MODEL SOLUTIONS...WITH
12Z RUNS OF GFS/GGEM/ECMWF COMING INTO A BIT BETTER AGREEMENT. ALL
THREE NOW FORECAST A SIGNIFICANT WAVE OF LOW PRESSURE RIDING ALONG
THE FRONTAL BOUNDARY. THE GFS IS STILL THE WEAKEST AND
COLDEST...WITH THE ECMWF STRONGEST AND WARM ENOUGH O CHANGE
PRECIPITATION TO RAIN EAST OF ROCHESTER. TAKING A CONSENSUS...EXPECT
SNOW IS THE MORE LIKELY FORM OF PRECIPITATION...WITH THE BEST CHANCE
FOR IT STILL COMING SUNDAY NIGHT INTO MONDAY. DEPENDING ON THE
STRENGTH AND TRACK OF THE LOW...SNOW ACCUMULATIONS COULD BE
SIGNIFICANT. IT IS STILL TOO EARLY TO DETERMINE SPECIFICS...WITH
PLENTY OF OPPORTUNITY FOR FUTURE SHIFTS IN MODEL GUIDANCE.
AFTER THIS...THERE IS GOOD MODEL AGREEMENT THAT ANOTHER SHOT OF VERY
COULD AIR WILL BUILD IN BEHIND WHATEVER LOW DOES DEVELOP. EXPECT
BELOW NORMAL TEMPERATURES AND FAIRLY WINDY CONDITIONS TUESDAY AND
WEDNESDAY. THIS ALSO IS LIKELY TO BRING MORE LAKE EFFECT SNOWS EAST
AND POSSIBLY NORTHEAST OF THE LAKES.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
REGIONAL RADAR CURRENTLY SHOWS A BAND OF LIGHT SNOW CONSOLIDATING
ACROSS THE NIAGARA FRONTIER AND EXTENDING EAST ALONG/NORTH OF THE NYS
THRUWAY. VSBYS WITHIN THIS BAND..THAT ENCOMPASSES
KBUF/KIAG/KROC...WILL REMAIN IFR WITH MVFR CIGS EXPECTED FOR MUCH OF
THE NIGHT AS THE BAND WILL REMAIN NEARLY STATIONARY. MEANWHILE...A
DRY SLOT HAS MOVED OVER THE WESTERN SOUTHERN TIER...BRINGING A BREAK
IN THE SNOWFALL. MESOSCALE MODEL GUIDANCE INDICATES THAT THIS BREAK
AT KJHW MAY LAST AS LATE AS 06-07Z BEFORE ANOTHER SHOT OF MOISTURE
BRINGS LIGHT SNOW BACK ACROSS THE TERMINAL.
MEANWHILE...KART IS STILL VFR AND SHOULD REMAIN SO UNTIL 11Z WHEN
THE BAND PIVOTS NORTHWARDS INTO THE NORTH COUNTRY...BRINGING
MVFR/IFR CONDITIONS. THESE CONDITIONS ARE EXPECTED TO PERSIST FOR
THE BALANCE OF THE TAF PERIOD.
IN ADDITION TO REDUCED VSBYS/CIGS DUE TO THE PRESENCE OF LIGHT
SNOW...FURTHER REDUCTIONS IN VSBYS WILL BE POSSIBLE DURING THE DAY
ON FRIDAY AS NORTHEASTERLY WINDS WILL INCREASE INTO THE 20KT
RANGE...MAKING BLOWING SNOW AN ISSUE ACROSS THE FORECAST AREA.
OUTLOOK...
THURSDAY AND THURSDAY NIGHT...IFR/MVFR WITH SNOW LIKELY.
FRIDAY...IFR/MVFR IN LAKE EFFECT SNOW SHOWERS SOUTHEAST OF THE
LAKES. OTHERWISE MAINLY VFR.
SATURDAY...VFR.
SATURDAY NIGHT AND SUNDAY...MVFR/IFR IN SNOW SHOWERS.
MONDAY...MVFR IN A CHANCE OF SNOW SHOWERS.
&&
.MARINE...
NORTHEASTERLY WINDS WILL FRESHEN TONIGHT AND THURSDAY AND BRING
SMALL CRAFT ADVISORY LEVEL CONDITIONS TO THE LAKES AS WELL AS THE
LOWER NIAGARA RIVER AS LOW PRESSURE APPROACHES THE REGION FROM THE
LOWER OHIO VALLEY. THESE WINDS WILL CONTINUE TO STRENGTHEN THURSDAY
AS THE LOW SLIDES BY TO OUR SOUTH ACROSS PENNSYLVANIA AND EVEN
COLDER AIR WRAPS IN BEHIND THIS LOW. THIS COLD ADVECTION WILL AID IN
KEEPING CONDITIONS ROUGH ON THE LAKES INTO FRIDAY MORNING BEFORE
HIGH PRESSURE MOVES ACROSS THE REGION LATER IN THE DAY...BRINGING A
BRIEF RESPITE BEFORE SOUTHWESTERLIES THEN FRESHEN SATURDAY AS
ANOTHER LOW PRESSURE SYSTEM APPROACHES THE REGION...THIS TIME FROM
NORTHERN ONTARIO.
&&
.CLIMATE...
VERY COLD AIR IS ON THE WAY FOR THE REGION THIS WEEK...WITH THE
COLD AIR PEAKING THURSDAY AND FRIDAY. HIGH TEMPERATURES ON FRIDAY
WILL LIKELY NOT GET OUT OF THE SINGLE NUMBERS ACROSS THE ENTIRE
REGION...AND NOT ABOVE ZERO EAST OF LAKE ONTARIO.
THE LAST TIME BUFFALO DID NOT GET TO 10 DEGREES FOR A DAYTIME HIGH
WAS 1/16/09...AND FOR ROCHESTER 3/6/07. AT WATERTOWN THE LAST TIME
THE HIGH DID NOT GET ABOVE ZERO WAS 1/22/2005.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...WIND CHILL WARNING FROM 4 PM THURSDAY TO NOON EST FRIDAY FOR
NYZ007-008.
WIND CHILL ADVISORY UNTIL 4 PM EST THURSDAY FOR NYZ007-008.
WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR NYZ001-002-
006-010>012-019-020-085.
WIND CHILL ADVISORY FROM 4 PM THURSDAY TO NOON EST FRIDAY FOR
NYZ001>006-010>014-019>021-085.
WINTER STORM WARNING UNTIL 6 AM EST FRIDAY FOR NYZ003>005-013-
014-021.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 6 AM EST FRIDAY FOR LOZ030.
SMALL CRAFT ADVISORY UNTIL 10 AM EST FRIDAY FOR LOZ042>045.
&&
$$
SYNOPSIS...THOMAS
NEAR TERM...WOOD
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...WOOD
MARINE...THOMAS/WOOD
CLIMATE...HITCHCOCK
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
1141 PM CST WED JAN 1 2014
.UPDATE...FOR 06Z AVIATION FORECAST
&&
.AVIATION...
SFC LOW PRESSURE FROM SW ARKANSAS TO NEAR PAH WILL CONTINUE TO
QUICKLY MOVE EASTWARD. MOISTURE POOLING AHEAD OF THIS LOW/S COLD
FRONT WILL HELP DETERIORATE CONDITIONS AT THE TERMINALS. HAVE
VCSH/TEMPOS FOR LIGHT RAIN NEARING 12Z THOUGH THERE COULD BE
BREAKS IN THE PRECIP. THEREAFTER...WITH THE COLD FRONTAL PASSAGE
ANY RAIN MAY CHANGEOVER TO A RASN MIX OR JUST SN AT THE TAF SITES
AS WINDS SHIFT AROUND TO THE NW AND BECOME QUITE GUSTY FROM LATE
THURS MORNING THROUGH THE REST OF THE TAF PERIOD. IFR TO LOW MVFR
CONDITIONS ARE EXPECTED WITH THE FROPA UNTIL ROUGHLY 00Z FRI.
&&
.PREV DISCUSSION... /ISSUED 849 PM CST WED JAN 1 2014/
UPDATE...
LATEST MOSAIC AND OHX RADAR IMAGERY SHOW LIGHT RAIN HAS ALREADY
DEVELOPED ACROSS WESTERN TN WITH ECHOES NOW SPREADING INTO
WESTERN ZONES. BASED ON THIS ADJUSTED POPS UPWARD FOR THE
REMAINDER OF THE NIGHT FOR ALL ZONES...WITH PRECIP CHANCES NOW
MORE IN LINE WITH 18Z/00Z RUNS. TEMPS SEEM REASONABLE AND WERE NOT
CHANGED...WITH TEMPS LIKELY FALLING SOME MORE THIS EVENING BEFORE
BECOMING STEADY OR RISING OVERNIGHT AS WAA INCREASES.
FOR THURSDAY...THE JUST IN 00Z NAM CONTINUES TO SHOW STRONG COLD
FRONT RACING ACROSS THE AREA DURING THE MORNING HOURS WITH
PRECIPITATION EXITING RIGHT ON ITS HEELS. AS WITH THE
GFS/ECMWF...NAM SHOWS MOISTURE MOVING OUT AT SAME TIME AS COLD AIR
RUSHES IN WITH ONLY A BRIEF WINDOW FOR A MIX/CHANGEOVER TO SNOW
DURING THE MORNING AND EARLY AFTERNOON HOURS FOR LOCATIONS WEST OF
THE PLATEAU. 01Z RAP AGREES WITH THIS SCENARIO...WHILE 18Z
GFS/12Z ECMWF ARE COLDER WITH PRECIPITATION LINGERING LONGER
BEHIND THE FRONT. THUS APPEARS BEST CHANCE FOR ANY SNOW ACCUMS
WEST OF THE PLATEAU ON THURSDAY WILL BE ACROSS NORTHWEST ZONES
WHERE WAA WILL HAVE LESS IMPACT AND CAA ARRIVES QUICKEST...AND A
DUSTING TO HALF INCH OF SNOW SEEMS POSSIBLE THERE. REST OF THE
CWA OFF THE PLATEAU MAY STAY TOO WARM BEFORE PRECIP EXITS WITH
LITTLE IF ANY SNOW ACCUMS. ON THE PLATEAU...WEST TO NORTHWEST
FLOW WILL FORCE MOISTURE UP THE HIGHER TERRAIN AND CHANGE RAIN
OVER TO SNOW DURING THE AFTERNOON...WITH LIGHT SNOW CONTINUING
INTO AT LEAST THE EVENING HOURS. APPEARS AREAS FROM MONTEREY TO
CROSSVILLE TO JAMESTOWN COULD EASILY SEE AROUND 1 INCH OF SNOW
ACCUM...POSSIBLY HIGHER...AND A WINTER WEATHER ADVISORY MAY BE
NEEDED FOR THE NORTHERN PLATEAU COUNTIES MAINLY DUE TO TRAVEL
IMPACTS AS TEMPERATURES FALL INTO THE 20S AND 10S BEFORE SNOW
COMES TO AN END. WILL LET MID SHIFT TAKE A LOOK AT THE FULL 00Z
MODEL SUITE BEFORE DECIDING ON WHETHER A WWA IS NEEDED.
SHAMBURGER
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AL
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1132 PM CST WED JAN 1 2014
.AVIATION... /00Z TAF UPDATE/
MVFR CIGS OVER CENTRAL TX ARE DECREASING ALONG AND AHEAD OF THE
FRONT...WITH THE EARLY EVENING PRE-FRONTAL LOW CLOUDS RETREATING TO
THE SOUTHEAST. FRONTAL TIMING HAS SLOWED DOWN TO BE MORE ON TRACK
FOR A 7-830Z PASSAGE FOR THE TAF SITES. GUSTY N WINDS TO AROUND
25 KNOTS SHOULD RELAX AFTER 18Z THURSDAY.
&&
.PREV DISCUSSION... /ISSUED 305 PM CST WED JAN 1 2014/
SHORT TERM (TONIGHT THROUGH THURSDAY NIGHT)...
THIS AFTERNOON A PERSISTENT STRATOCU DECK WAS LOCATED EAST OF A LINE
FROM CARRIZO SPRINGS TO FREDERICKSBURG TO GEORGETOWN. THIS CLOUD DECK
WILL SLOWLY ERODE FROM WEST TO EAST THIS EVENING IN ADVANCE OF THE
COLD FRONT. AT 21Z THE COLD FRONT WAS LOCATED OVER THE TEXAS SOUTH
PLAINS MOVING SOUTHWARD. THE FRONT WILL ENTER THE HILL COUNTRY
BETWEEN 10 AND 11 PM THIS EVENING BASED ON THE LATEST RUC13 MODEL
SOLUTION. THIS WILL BE A DRY FROPA...HOWEVER A BRIEF PERIOD OF
PRE-FRONTAL PATCHY FOG IS POSSIBLE SOUTH AND EAST OF THE I-35
CORRIDOR WITH MORE WIDESPREAD FOG POSSIBLE ACROSS DIMMIT AND
SOUTHERN MAVERICK COUNTIES. POST-FRONTAL WINDS TONIGHT WILL BE
NORTHERLY AT 10 TO 20 MPH WITH GUSTS OF 30 MPH. LOWS THURSDAY
MORNING WILL RANGE FROM AROUND 30 ACROSS THE HILL COUNTRY TO NEAR
40 SOUTHWEST. THURSDAY WILL BE SUNNY AND COOLER AS CAA CONTINUES
THROUGHOUT THE DAY. HIGHS THURSDAY WILL BE 8 TO 12 DEGREES BELOW
NORMAL. GUSTY NORTHERLY WINDS WILL DIMINISH BY EVENING WITH THE
WEAKENING PRESSURE GRADIENT. GOOD RADIATIONAL COOLING WILL OCCUR
THURSDAY NIGHT INTO FRIDAY MORNING. THIS WILL RESULT IN A HARD
FREEZE FOR MUCH OF SOUTH CENTRAL TEXAS. THE LOW TEMP FCST FOR
THURSDAY NIGHT WILL BE A BLEND OF THE MET/MAV/ECMWF MOS GUIDANCE.
LONG TERM (FRIDAY THROUGH WEDNESDAY)...
BELOW NORMAL TEMPERATURES WILL CONTINUE NEXT WEEK DUE TO A SERIES
OF FROPAS. HOWEVER A BRIEF WARMING TREND WILL OCCUR FRIDAY AND
SATURDAY. HIGHS ON SATURDAY WILL BE IN LOWER 60S ACROSS THE HILL
COUNTRY WITH MID 60S ACROSS THE REMAINDER OF SOUTH CENTRAL TEXAS.
THE NEXT COLD FRONT WILL MOVE ACROSS THE REGION ON SUNDAY. ONCE
AGAIN AFTERNOON HIGHS WILL BE 5 TO 8 DEGREES BELOW NORMAL...RANGING
FROM THE UPPER 40S HILL COUNTRY TO NEAR 60 SOUTHWEST. LOW LEVEL
MOISTURE WILL BE LIMITED...WITH ONLY A SLIGHT CHANCE OF SHOWERS
FOR OUR EXTREME EASTERN COUNTIES. A RE-ENFORCEMENT OF THE COLD
AIRMASS WILL OCCUR ON TUESDAY WITH THE PASSAGE OF ANOTHER COLD
FRONT. WAA/OVERRUNNING/ISENTROPIC LIFT ON WEDNESDAY WILL LEAD TO
A SLIGHT CHANCE OF SHOWERS FOR MUCH OF THE REGION.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 36 52 29 53 40 / 0 0 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 33 51 24 52 35 / - 0 0 0 0
NEW BRAUNFELS MUNI AIRPORT 35 54 26 54 37 / 0 0 0 0 0
BURNET MUNI AIRPORT 31 49 24 52 37 / 0 0 0 0 0
DEL RIO INTL AIRPORT 36 55 30 55 38 / 0 0 0 0 0
GEORGETOWN MUNI AIRPORT 31 50 24 52 39 / 0 0 0 0 0
HONDO MUNI AIRPORT 37 57 25 55 38 / 0 0 0 0 0
SAN MARCOS MUNI AIRPORT 35 52 26 54 37 / 0 0 0 0 0
LA GRANGE - FAYETTE REGIONAL 36 51 28 53 41 / 10 0 0 0 0
SAN ANTONIO INTL AIRPORT 37 56 28 55 40 / 0 0 0 0 0
STINSON MUNI AIRPORT 39 57 29 56 41 / 0 0 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...02
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
952 PM MST WED JAN 1 2014
.UPDATE...
ISSUED AT 942 PM MST WED JAN 1 2014
LATEST 00Z MODEL GUIDANCE SHOWING THE RETURN OF STRONG WINDS...AT
LEAST FOR OUR WIND PRONE AREAS AND POSSIBLY A LITTLE MORE
WIDESPREAD TOMORROW NIGHT. LATEST WRKHGT PRODUCT SHOWING CRAIG TO
CASPER 850/700MB HEIGHT GRADIENTS INCREASING TO TO 57/53 MTRS BY
06Z TOMORROW NIGHT...LASTING THROUGH AT LEAST 00Z SATURDAY. LATEST
00Z 700MB WINDS OVER SOUTHEAST WYOMING INCREASING TO 50KTS
TOMORROW NIGHT...UP TO 70KTS FRIDAY AFTERNOON. WENT AHEAD AND
ISSUED A HIGH WIND WATCH FOR THE WIND PRONE AREAS TOMORROW NIGHT.
LATEST MAV MOS WINDS FOR CHEYENNE...LARAMIE AND RAWLINS ALSO
HINTING THAT THIS COULD BE A MORE WIDESPREAD HIGH WIND EVENT.
RAWLINS INCREASES TO 30KTS FRIDAY AFTERNOON...LARAMIE 29KTS AND
CHEYENNE...27KTS. UPDATES HAVE BEEN SENT.
&&
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 300 PM MST WED JAN 1 2014
AREA OF COOLER CLOUD TOPS WITH ASSOCIATED LIGHT SNOW PROGRESSING
SOUTH OVER THE SOUTHERN PORTION OF THE CWA EARLY THIS AFTERNOON.
EXPECT THIS AREA TO MOVE SOUTH OUT OF THE CWA BY EARLY THIS
EVENING WITH SOME CLEARING ACROSS THE CWA OVERNIGHT. NNW UPPER
FLOW WILL HOLD OVER THE CWA INTO THURSDAY THEN GRADUALLY BACK TO
NWLY THEN WESTERLY THURSDAY NIGHT THROUGH FRIDAY AHEAD OF THE NEXT
UPPER TROF WHICH WILL MOVE INTO THE NRN ROCKYS BY LATE FRIDAY. AS
THIS OCCURS LEE TROFFING WILL DEVELOP AND DEEPEN OVER THE HIGH
PLAINS THURSDAY AND HOLD THROUGH FRIDAY WITH RESULTANT DOWNSLOPE
FLOW ALLOWING FOR MILDER TEMPERATURES. WILL UNDERCUT GUIDANCE SOME
FOR TEMPS ESPECIALLY THURSDAY DUE TO SNOW COVER DEPOSITED TODAY.
OTHER CONCERN WILL BE FOR POTENTIAL STRONG WINDS OVER THE WIND
PRONE AREAS FRIDAY AHEAD OF THE APPROACHING UPPER SYSTEM. 700MB
WINDS LOOK TO INCREASE TO OVER 50KTS BY FRIDAY AFTERNOON AND
PERSIST INTO EARLY EVENING BEFORE DIMINISHING. MAY NEED A HILITE
BUT WILL SEE WHAT LATER PROGS DEPICT. OTHERWISE MAINLY DRY ACROSS
THE CWA THOUGH SOME SNOW SHOWERS SHOULD INCREASE OVER THE HIGHER
MTNS BY LATE FRIDAY AS MOISTURE INCREASES AND RIDES UP THE WEST SLOPES.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 300 PM MST WED JAN 1 2014
FRIDAY NIGHT/SATURDAY...NEXT POSITIVELY TILTED SHORTWAVE TROUGH
ALOFT MOVES ACROSS WYOMING AND COLORADO...SPREADING LIGHT TO
MODERATE...AND OCCASIONALLY HEAVY SNOW ACROSS OUR COUNTIES. BASED ON
PROJECTED MOISTURE DEPTH ALONG WITH LIFT PROVIDED BY
DYNAMICS...OROGRAPHICS...UPSLOPE AND CYCLONIC CURVATURE
ALOFT...EXPECT MOST AREAS TO AT LEAST SEE A DUSTING OF SNOW...WITH
50 TO 100 PERCENT POPS AT MOST LOCATIONS...ESPECIALLY THE TERRAIN
FAVORED UPSLOPE LOCATIONS SUCH AS THE EASTERN SLOPES OF THE
LARAMIE RANGE FROM WHEATLAND TO CHEYENNE. BY LATE SATURDAY
AFTERNOON...THE BULK OF THE AREAL SNOW COVERAGE WILL HAVE MOVED
INTO COLORADO ALONG WITH THE PRIMARY DYNAMICS OF THE SHORTWAVE
TROUGH ALOFT.
SUNDAY...NEXT POLAR EXPRESS ARRIVES WITH ALL MODELS SHOWING STRONG
ARCTIC AIR INTRUSION...WHICH WILL QUITE LIKELY SPREAD LIGHT SNOW
ACROSS OUR COUNTIES WITH MINIMAL ACCUMULATION DUE TO THE LIMITED
MOISTURE WITH THESE TYPES OF ARCTIC INTRUSIONS. WOULD NOT BE
SURPRISED TO SEE MAXIMUM TEMPERATURES ONLY IN THE SINGLE DIGITS AND
TEENS BASED ON THE PROJECTED THICKNESSES AND 700 MB TEMPERATURES
NEAR -24 CELSIUS...THUS LATER SHIFTS MAY NEED TO LOWER OUR HIGH
TEMPERATURES.
MONDAY...ARCTIC COLD AIR PROGGED TO REMAIN ENTRENCHED UNDER BRISK
NORTH NORTHWEST FLOW ALOFT. MAXIMUM TEMPERATURES IN THE SINGLE
DIGITS AND MOSTLY TEENS BASED ON 700 MB TEMPERATURES STILL NEAR -16
CELSIUS. NO SNOWFALL DUE TO MINIMAL LOW AND MID LEVEL MOISTURE
AVAILABILITY AND MINIMAL LIFT.
TUESDAY...FLOW ALOFT BACKS TO WEST AND WEAKENS. WITH THE DENSE AND
COLD ARCTIC AIRMASS ENTRENCHED...AND WITH RELATIVELY WEAK WEST FLOW
ALOFT...BELIEVE ARCTIC AIR WILL BUDGE VERY LITTLE...THUS MAXIMUM
TEMPERATURES STILL BELOW FREEZING AT MOST LOCALES...THOUGH WITH
TEMPERATURES MODERATING AS 700 MB TEMPERATURES WARM TO NEAR -6
CELSIUS.
WEDNESDAY...MODELS SIMILAR IN DEPICTION OF A WEAK...LOW AMPLITUDE
SHORTWAVE TROUGH ALOFT MOVING ACROSS OUR COUNTIES WITH THE BULK OF
THE SNOW REMAINING TO OUR SOUTH OVER COLORADO...THOUGH WILL PAINT
SOME LOW OROGRAPHIC SNOWS ACROSS OUR NORTHERN LARAMIE...SNOWY AND
SIERRA MADRE RANGES...AND DRY ELSEWHERE. ARCTIC AIR WILL RETREAT TO
OUR EAST...ALLOWING DOWNSLOPE CHINOOK WINDS TO MODERATE TEMPERATURES
WITH MAXIMUMS ABOVE FREEZING AT MOST LOCATIONS.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 942 PM MST WED JAN 1 2014
LATEST 11-3.9U SATELLITE IMAGERY SHOWING MOST OF SOUTHEAST WYOMING
FREE OF CLOUDS...BUT THERE IS SOME STRATUS BEING REPORTED UP BY
DOUGLAS. WITH A WESTERLY DOWNSLOPE WIND THOUGH...THINK CHANCES FOR
LOW CLOUDS/FOG WILL BE VERY LOCALIZED AND KEPT ALL AIRPORTS VFR
THROUGH THE NEXT 24 HOURS. LATEST HRRR MODEL RUN SUPPORTS THIS
DECISION AS WELL.
&&
.FIRE WEATHER...
ISSUED AT 300 PM MST WED JAN 1 2014
NO SIGNIFICANT CONCERNS SEEN THROUGH THE WEEKEND WITH MAINLY NON-
CRITICAL CONDITIONS. AREAS OF GUSTY WINDS WILL RETURN BY LATE
THURSDAY AND CONTINUE INTO FRIDAY AHEAD OF NEXT COLD FRONT WHICH
SHOULD PASS ACROSS THE REGION SATURDAY BRINGING MUCH COLDER
TEMPERATURES. LINGERING LIGHT SNOW NEAR THE COLORADO BORDER THIS
EVENING THEN MAINLY DRY UNTIL SATURDAY WHEN SOME LIGHT SNOWS
EXPECTED AGAIN BEHIND THE COLD FRONT.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...HIGH WIND WATCH FROM THURSDAY EVENING THROUGH FRIDAY EVENING FOR
WYZ106-110-116-117.
NE...NONE.
&&
$$
UPDATE...CLAYCOMB
SHORT TERM...RE
LONG TERM...RUBIN
AVIATION...CLAYCOMB
FIRE WEATHER...RE
AREA FORECAST DISCUSSION
NWS PUEBLO CO
419 AM MST THU JAN 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 419 AM MST THU JAN 2 2014
QUIET WEATHER IS EXPECTED IN THE SHORT TERM ASIDE FROM SOME VEXING
STRATUS THIS MORNING ALONG THE SOUTHERN SLOPES OF THE PALMER DIVIDE
WHERE LIGHT UPSLOPE IS WORKING ON SOME SHALLOW LOW LEVEL MOISTURE.
WINDS ALOFT ARE PROGGED TO INCREASE OUT OF THE NORTHWEST LATER THIS
MORNING WHICH SHOULD ERODE THE LOW CLOUDS EASTWARD AND DISSIPATE
THEM ENTIRELY BY MID MORNING. OTHERWISE DRY WEATHER IS EXPECTED
TODAY WITH SOME INCREASING HIGH CLOUDINESS INVADING IN THE AFTERNOON
AS WEAK SHORTWAVE CURRENTLY OVER ID DROPS TO THE SOUTHEAST ACROSS CO
THIS EVENING. HIGH TEMPERATURES TODAY SHOULD WARM OVER THOSE OF
YESTERDAY FOR THE PLAINS...EXCEPT IN THE SNOW COVERED SAN LUIS
VALLEY WHERE LIGHT WINDS SHOULD KEEP TEMPERATURES IN THE 20S
AGAIN.
FOR TONIGHT...LEE TROF SHOULD KEEP TEMPS IN THE LOWER 30S FOR
OVERNIGHT LOWS ALONG THE LOWER EASTERN SLOPES OF THE SE MTS/ADJACENT
PLAINS. ELSEWHERE CLEARING SKIES SHOULD ALLOW TEMPERATURES TO DROP
INTO THE TEENS AND 20S WITH NEGATIVE SINGLE DIGITS ACROSS THE SAN
LUIS VALLEY. -KT
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 419 AM MST THU JAN 2 2014
.FRIDAY...WARMING ALOFT CONTINUES AHEAD OF THE SHORTWAVE
APPROACHING FROM THE NORTHWEST. TEMPERATURES AT 700MB ARE FORECAST
TO BE AROUND +2C. SUSPECT THERE WILL BE ENOUGH MIXING FOR HIGHS TO
BE AROUND 60F OVER MUCH OF THE PLAINS. TEMPERATURES WILL ALSO BE
RELATIVELY MILD FOR THE MOUNTAINS. IN THE SAN LUIS
VALLEY...BELIEVE THAT APPROACHING TROUGH WILL NOT ALLOW FOR MIXING
DURING THE DAY...AND HAVE TEMPERATURES BELOW GUIDANCE...WHICH HAS
FREQUENTLY OCCURRED ON DAYS WITH LITTLE MIXING.
.SATURDAY...UPPER TROUGH MOVES INTO THE STATE FROM THE
NORTHWEST...WITH A COLD FRONT MOVING IN FROM THE NORTH OVER THE
PLAINS AND EASTERN MOUNTAINS. TRENDED TOWARDS THE MORE MOIST GFS
AND EC AS THE NAM HAS TENDED TO BE TOO DRY IN THE PAST FEW WEEKS.
NORTHWEST FLOW ALOFT FAVORS SNOWFALL OVER THE MOUNTAINS OF LAKE
AND CHAFFEE COUNTIES. CURRENT GRIDS HAVE SNOWFALL AMOUNTS
APPROACHING ADVISORY CRITERIA...AND WOULD NOT BE TOO SURPRISED IF
AN ADVISORY IS NEEDED FOR SATURDAY. FURTHER EAST...MODELS
CONSENSUS IS TO HAVE THE FRONTAL PASSAGE SOMETIME DURING THE
MORNING. GFS AND EC CONTINUE TO SUGGEST THE POTENTIAL FOR SOME
LIGHT SNOW DURING THE AFTERNOON WHILE THE NAM IS MUCH DRIER.
LEANED SLIGHTLY TOWARDS THE WETTER GFS/EC SOLUTION WHICH HAS THE
TROUGH SLIGHTLY FURTHER SOUTH. THERE COULD BE A BRIEF PERIOD OF
UPGLIDE AROUND 600MB OVER THE LOWER LEVEL COLD AIR. TEMPERATURES
AT THE UPGLIDE LEVEL WILL BE AROUND -15C...WHICH IS IN THE PRIME
REGION FOR DENDRITIC GROWTH. SUSPECT ANY ACCUMULATIONS WILL BE ON
THE LIGHT SIDE...MAYBE AN INCH OR TWO AT MOST. CURRENT GRIDS ONLY
HAVE SCATTERED TO HIGH SCATTERED POPS. IN THE SAN LUIS
VALLEY...DISTURBANCE COULD RESULT IN MIXING IN THE VALLEY...BUT
AIR ALOFT WILL BE COLD WHICH WOULD MINIMIZE THE AMOUNT OF WARMING.
.SUNDAY AND MONDAY...NEXT DISTURBANCE APPROACHES THE REGION FROM
THE NORTHWEST ON SUNDAY. TROUGH WILL BE FURTHER EAST THAN THE TROUGH
ON SATURDAY...SO ANTICIPATE LESS SNOWFALL. ANOTHER COLD FRONT WILL
MOVE ACROSS THE PLAINS AND EASTERN MOUNTAINS DURING THE DAY ON
SUNDAY. MAIN QUESTION IS HOW COLD IT WILL BE SUNDAY NIGHT AND
MONDAY. THE COLDEST AIR WILL STAY TO THE NORTHEAST OF THE
REGION...AND THE EC HAS THE COLD AIR MOVING SLIGHTLY FURTHER WEST
THAN THE GFS. GRIDS HAVE A COMPROMISE BETWEEN THE GFS AND EC WITH
HIGHS IN THE 20S OVER THE PLAINS. OVER THE MOUNTAINS...SOME
WARMING COULD OCCUR DURING MONDAY AFTERNOON AS THE LOW LEVEL COLD
AIR WILL BECOME SHALLOWER.
.TUESDAY AND WEDNESDAY....COLD AIR WILL MOVE EAST ON TUESDAY...AND FLOW
ALOFT WILL BECOME WESTERLY WITH WARMING ALOFT. ANTICIPATE A
WARMING TREND TO DEVELOP ON TUESDAY WITH THE GREATEST AMOUNT OF
WARMING OVER AND NEAR THE MOUNTAINS. BY WEDNESDAY...THE NEXT
DISTURBANCE WILL MOVE INTO THE REGION. CURRENTLY...THE TROUGH
APPEARS TO BE WEAK...AND ONLY HAVE ISOLATED TO SCATTERED POPS IN
THE GRIDS. --PGW--
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 419 AM MST THU JAN 2 2014
IFR TO LIFR STRATUS HAS DEVELOPED OVER KCOS AND KPUB...WITH VIS
DROPPING TO AROUND 1 1/2 SM AT KPUB AT TIMES IN FOG IN THE PAST
HOUR. THIS IS DUE TO LIGHT UPSLOPE WINDS BEHIND YESTERDAY`S COLD
FRONT. FORECAST MODELS HAVE DRY WESTERLY WINDS ALOFT INCREASING
LATER THIS MORNING WITH STRATUS AND FOG PUSHING EASTWARD THOUGH
TIMING IN MODELS VARIES SIGNIFICANTLY...PUTTING UNCERTAINTY HIGH AS
TO TIMING THE STRATUS OUT OF BOTH TERMINALS. LATEST RUC13 SUGGESTS
AROUND 14-15Z WITH KCOS BREAKING OUT FIRST...WHICH SEEMS
REASONABLE...BUT WILL NEED TO MONITOR FOR POTENTIAL CHANGES.
MEANWHILE DRY AIR ALOFT HAS KEPT FOG FROM FORMING AT KALS THUS FAR.
AFTER 15Z...EXPECT VFR CONDITIONS TO PREVAIL AT THE TERMINALS THOUGH
SOME IFR TO LIFR STRATUS COULD LINGER TO 17Z TO THE EAST OF KCOS AND
KPUB. OTHERWISE WINDS SHOULD REMAIN LIGHT WITH SPEEDS UNDER 12 KTS.
SOME HIGH CLOUDINESS WILL INCREASE OVER THE AREA DURING THE
AFTERNOON. DO NOT ANTICIPATE THE RETURN OF STRATUS OR FOG TONIGHT
AT THE TERMINALS THOUGH KALS ALWAYS CARRIES A LOW PROBABILITY OVER
THE PERSISTENT SNOW COVER. FOR NOW THREAT APPEARS TOO LOW AT THIS
POINT TO WARRANT MENTION IN THE KALS TAF. -KT
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...KT
LONG TERM...PGW
AVIATION...KT
AREA FORECAST DISCUSSION
NWS ALBANY NY
859 AM EST THU JAN 2 2014
.SYNOPSIS...
LOW PRESSURE MOVING ACROSS THE OHIO VALLEY TODAY WILL
REFORM OFF THE MID ATLANTIC COAST THIS EVENING...AND MOVE OFF THE
NORTHEAST COAST TONIGHT INTO TOMORROW. THIS WILL ALLOW FOR A
PROLONGED PERIOD OF SNOW ACROSS THE REGION THROUGH TOMORROW
MORNING. VERY COLD AIR WILL ACCOMPANY THIS SNOW...ESPECIALLY ACROSS
NORTHERN AND HIGH TERRAIN AREAS...WITH DANGEROUSLY COLD WIND CHILL
VALUES. DRY...BUT CONTINUED COLD WEATHER WILL BE IN PLACE ON
SATURDAY...BEFORE ANOTHER STORM THREATENS THE REGION FOR SUNDAY
INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 845 AM EST...A BAND OF MODERATE SNOW HAS SET UP ACROSS THE
CAPITAL REGION...MOHAWK VALLEY REGION...EXTENDING INTO THE
SCHOHARIE VALLEY AND NE CATSKILLS...AND ALSO INTO SOUTHERN VT AND
THE NORTHERN BERKSHIRES. THIS BAND APPEARS TO BE IN ASSOCIATION
WITH STRONG 850-700 MB FRONTOGENETICAL FORCING...COMBINED WITH
ISENTROPIC LIFT. THE LATEST RUC13 SUGGESTS THAT THIS BAND OF MID
LEVEL FORCING...AND HEAVIER SNOWFALL...SHOULD SLOWLY LIFT
NORTHWARD LATER THIS MORNING INTO THE AFTERNOON HOURS...WITH THE
STEADIEST SNOWFALL SHIFTING INTO THE NORTH SIDE OF THE MOHAWK
VALLEY...THE LAKE GEORGE/SARATOGA REGION...AND SOUTHERN VT. IT IS
POSSIBLE THAT AREAS TO THE SOUTH...INCLUDING THE CAPITAL
REGION...EXPERIENCE A BREAK...OR AT LEAST SOME PERIODS OF LIGHTER
SNOWFALL...FOR MUCH OF THE AFTERNOON. WHERE THE BAND SETS UP...AN
ADDITIONAL 3-6 INCHES ARE EXPECTED THROUGH LATE AFTERNOON. FURTHER
SOUTH...GENERALLY 1-3 INCHES ARE EXPECTED...WITH EVEN LESS
POSSIBLE ACROSS PORTIONS OF THE MID HUDSON VALLEY AND NW CT REGION.
TEMPS HAVE FALLEN MUCH LOWER THAN ANY GUIDANCE SUGGESTED...WITH
CURRENT TEMPS GENERALLY RANGING FROM ZERO TO 5 ABOVE IN VALLEY
AREAS AND POINTS NORTH AND WEST...WITH SOME SINGLE DIGITS BELOW
ZERO ACROSS THE SOUTHERN ADIRONDACKS. FURTHER SOUTH AND
EAST...TEMPS RANGE FROM THE SINGLE DIGITS TO MID TEENS. WE EXPECT
TEMPS TO HOLD NEARLY STEADY THROUGH THIS AFTERNOON...ALTHOUGH
SHOULD FALL SEVERAL MORE DEGREES ACROSS PORTIONS OF THE MID HUDSON
VALLEY REGION AS THE COLD DENSE AIR CONTINUES TO SETTLE SOUTHWARD.
SO...EXPECT MOST VALLEY AREAS TO RANGE BETWEEN ZERO AND 10
ABOVE...WITH THE SOUTHERN ADIRONDACKS AND HIGHER ELEVATIONS ACROSS
WESTERN NEW ENGLAND POSSIBLY HOLDING AROUND ZERO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
BY THIS EVENING...PRESSURE FALLS WILL BEGIN OCCURRING OFF THE MID
ATLANTIC COAST...AS A NEW AREA OF LOW PRESSURE FORMS OFF THE COAST
OF VIRGINA. THIS SURFACE LOW WILL THEN TRACK NORTHEASTWARD WELL
OFF THE COAST OF THE NORTHEASTERN US. ALTHOUGH THE SURFACE LOW
WON/T BE TOO CLOSE TO OUR REGION...IT WILL STILL BE ABLE TO THROW
SOME ADDITIONAL ATLANTIC MOISTURE BACK OUR WAY. WITH THE STRONG
UPPER TROUGH PASSING OVERHEAD...STEADY SNOWFALL LOOKS TO OCCUR
ACROSS THE ENTIRE REGION...WITH THE HEAVIEST AMOUNTS ACROSS HIGH
TERRAIN AREAS OF THE SOUTHERN AND EASTERN PARTS OF THE CWA.
WITH CONTINUED VERY HIGH SNOW TO LIQUID RATIOS...ADDITIONAL LIGHT TO
MODERATE SNOW ACCUMULATIONS ARE EXPECTED OVERNIGHT...ALLOWING FOR
STORM TOTAL ACCUMULATION OF 6 TO 12 INCHES OVER MUCH OF THE REGION
BY TOMORROW MORNING. SLIGHTLY LOWER AMOUNTS ARE EXPECTED OVER THE
WESTERN ADIRONDACKS WHERE LESS QPF IS EXPECTED...AND A FEW SPOTS
IN THE HIGH TERRAIN OF THE CATSKILLS...GREENS...AND BERKSHIRES MAY
SEE CLOSE 15 INCHES IN TOTAL. STEADY SNOW LOOKS TO TAPER OFF
AROUND SUNRISE TOMORROW.
WITH THE INCREASING PRESSURE GRADIENT DUE TO THE DEVELOPING LOW
PRESSURE...N-NE WINDS WILL PICK UP LATE TONIGHT INTO TOMORROW
MORNING. DUE TO THE VERY LIGHT AND FLUFFY SNOW...THIS WILL ALLOW
FOR BLOWING AND DRIFTING OF SNOWFALL. TEMPS WILL BE VERY COLD
TONIGHT WITH TEMPS RANGING FROM 25 BELOW ZERO OVER THE ADIRONDACKS
TO 10 ABOVE OVER THE MID HUDSON VALLEY AND NW CT. WITH THE GUSTY
WINDS...WIND CHILL VALUES WILL BE AS LOW AS -25 TO -40 OVER THE
ADIRONDACKS...AND -10 TO -25 ELSEWHERE. BECAUSE OF THIS...A WIND
CHILL WARNING HAS BEEN ISSUED FOR THE ADIRONDACKS...AND WIND CHILL
INFORMATION HAS BEEN POSTED IN OUR WINTER STORM WARNING /WSW/ FOR
THE REMAINDER OF THE REGION.
A FEW LINGERING SNOW SHOWERS MAY AFFECT EASTERN AREAS FOR TOMORROW
MORNING...OTHERWISE SOME SUNSHINE SHOULD RETURN BY AFTN. DESPITE
THE SUN RETURNING...IT WILL REMAIN VERY COLD WITH TEMPS IN THE
SINGLE DIGITS. SOME AREAS IN THE ADIRONDACKS AND WESTERN MOHAWK
VALLEY MAY NOT EVEN RISE ABOVE ZERO DURING THE DAY FRIDAY.
HIGH PRESSURE WILL MOVE OVER THE REGION FRIDAY NIGHT...ALLOWING
SKIES TO BE MAINLY CLEAR FOR MUCH OF THE REGION. WINDS WILL
LIGHTEN UP...AND WITH THE FRESH DEEP SNOW PACK...A VERY COLD NIGHT
IS IN STORE FOR FRIDAY NIGHT. THE ENTIRE CWA LOOKS TO DROP BELOW
ZERO...WITH TEMPS IN THE CAPITAL REGION DOWN AROUND -8 TO -15.
TEMPS AROUND GLENS FALLS AND IN THE ADIRONDACKS WILL BE -20 TO
-25. BEFORE WINDS LIGHTEN UP...ADDITIONAL WIND CHILL HEADLINES MAY
BE NEEDED FOR FRI NIGHT/EARLY SAT...AND THIS WILL BE MENTIONED IN
THE HWO. EVEN WITHOUT WIND...IT WILL BE BRUTALLY COLD ACROSS THE
WHOLE AREA...AND PRECAUTIONS WILL NEED TO BE TAKEN TO PREVENT
DAMAGE TO HOMES...BUSINESSES...AND LIVESTOCK.
HIGH PRESSURE WILL CONTINUE TO ALLOW FOR QUIET AND DRY WEATHER ON
SATURDAY. TEMPS WILL REMAIN BELOW NORMAL...BUT WILL MODERATE
SOMEWHAT FROM THE BRUTALLY COLD LEVELS OF FRI/FRI NIGHT...AS THE
HIGH PRESSURE AREA BEGINS TO SHIFT EASTWARD. MAX TEMPS ON SAT AFTN
LOOK TO REACH THE TEENS TO MID 20S ACROSS THE AREA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ANOTHER STORM SYSTEM FOR SUNDAY NIGHT INTO MONDAY WHICH SHOULD BRING
SNOW...SLEET...FREEZING RAIN AND RAIN TO THE AREA.
WE START OUT THE PERIOD A WITH A DEEP TROUGH DIGGING IN ACROSS THE
CENTRAL CONUS WHILE A STRONG UPPER LOW DROPS SOUTHWARD TOWARD THE
GREAT LAKES REGION. AT THE SURFACE...A LOW PRESSURE SYSTEM OVER THE
GREAT LAKES REGION WILL MOVE NORTHEASTWARD TOWARD HUDSON BAY CANADA
WITH ITS COLD FRONT TRAILING OFF TO THE SOUTHWEST ACROSS THE PLAINS
INTO THE DEEP SOUTH. THIS SYSTEM WILL NOT DIRECTLY IMPACT OUR
REGION. HOWEVER AS A POTENT SHORT WAVE ROTATING THROUGH THE BASE OF
THE DEEP TROUGH SURFACE LOW WILL SPIN UP ON THE COLD FRONTAL
BOUNDARY. IT IS THIS SYSTEM THAT WILL BRING A WINTRY MESS TO THE OUR
REGION TO CLOSE OUT THE WEEK AND START THE NEW WORK WEEK.
THERE IS MUCH UNCERTAINTY IN THE FORECAST AS MODEL DIFFERENCES
CONTINUE...HOWEVER THE ECMWF AND GFS HAVE TRENDED TOWARD EACH OTHER.
THE ECMWF IS STILL TRACKING THE LOW ACROSS THE OHIO VALLEY THEN
SAINT LAWRENCE VALLEY WHILE THE GFS TAKES THE LOW ACROSS NEW YORK
AND NEW ENGLAND SUNDAY NIGHT INTO MONDAY. THERE IS A WIDE SPREAD IN
THE GFSENSEMBLE TRACKS WITH THE OPERATIONAL GFS ON THE WEST SIDE OF
THE SOLUTIONS AND THE ECMWF MORE IN LINE WITH THE MOST WESTERN
MEMBERS. THE EXACT TRACK OF THE LOW WILL DETERMINE THE THERMAL
PROFILE AND THEREFORE P-TYPES AS WARMER AIR SURGES IN AHEAD OF THE
SYSTEM. HAVE FOLLOWED GUIDANCE FROM THE WEATHER PREDICTION CENTER
WHICH USED A BLENDED MODEL APPROACH.
BASED ON THIS TRACK AND TIMING TEMPERATURES SHOULD PEAK IN THE
MONDAY MORNING THEN FALL DURING THE AFTERNOON WITH THE PASSAGE OF
THE SYSTEM. DID UNDERCUT TEMPERATURES AS IT WILL BE HARD TO WARM UP
WITH WIDESPREAD DEEP FRESH SNOWPACK ACROSS AREA. AREAS MAINLY TO THE
EAST OF THE HUDSON RIVER VALLEY SHOULD WARM INTO THE LOWER/MID 40S.
A STRONG 850 MB JET OF 40 TO 60 KNOTS WILL BRING WARMER AIR IN ALOFT
AND THE STAGE WILL BE SET FOR SNOW...SLEET...FREEZING RAIN AND RAIN
ESPECIALLY LATE SUNDAY NIGHT INTO MONDAY MORNING. WILL MENTION STORM
IN OUR HAZARDOUS WEATHER OUTLOOK. THE PRECIPITATION SHOULD TAPER OFF
BY MONDAY EVENING WITH IT CHANGING BACK TO SNOW POSSIBLY BEFORE
ENDING AS COLD AIR IS USHERING IN. CONDITIONS WILL BECOME FAVORABLE
FOR LAKE EFFECT SNOWS IN THE WAKE OF THE SYSTEM.
COLDER AIR WILL SURGE IN BY 12Z/TUESDAY 850 MB TEMPERATURES ARE
EXPECTED TO DROP TO AROUND -25C...WITH SURFACE TEMPERATURES
BOTTOMING OUT INTO THE SINGLE DIGITS BY SUNRISE TUESDAY. DAYTIME
HIGHS TUESDAY AND WEDNESDAY WILL BE SIMILAR TO WHAT OUR NORMAL LOWS
SHOULD BE. WINDS WILL BE BRISK TUESDAY ONLY MAKING IT COLDER. COULD
HAVE ISSUES WITH WIND CHILLS AGAIN TUESDAY NIGHT INTO WEDNESDAY
MORNING.
&&
.AVIATION /14Z THURSDAY THROUGH MONDAY/...
SNOW WILL CONTINUE THROUGH THE TAF PERIOD...12Z/FRIDAY. THE SNOW
WILL COME DOWN HEAVIEST THIS EVENING AS AREA OF LOW PRESSURE MOVES
OFF THE MID ATLANTIC COAST AND STRENGTHENS TONIGHT. IFR CONDITIONS
WILL LOWER TO LIFR FOR THE EVENING WITH THE HEAVIER SNOW. AN
IMPROVEMENT TO MVFR IS EXPECTED TO LATE IN THE PERIOD AS THE SNOW
LIGHTENS UP.
NORTH TO NORTHEAST WINDS AROUND 10 KNOTS WILL SHIFT MORE TO THE
NORTH AS THE DAY PROGRESSES AND INCREASE IN SPEED AS LOW MOVES OFF
THE MID ATLANTIC COAST AND STRENGTHENS. GUSTS TO AROUND 20 KNOTS ARE
EXPECTED.
OUTLOOK...
FRI NIGHT-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN...SLEET. SUN
NIGHT-MON: HIGH OPERATIONAL IMPACT. LIKELY RA...SN...FZRA...SLEET.
MON NIGHT-TUE: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC PROBLEMS ARE EXPECTED OVER THE NEXT FIVE
DAYS.
A STORM SYSTEM WILL BRING SNOW TO THE REGION TODAY THROUGH
TOMORROW MORNING. VERY COLD TEMPERATURES ARE EXPECTED LATE THIS
WEEK...WHICH WILL CONTINUE TO ALLOW RIVER AND LAKE ICE TO FORM AND
THICKEN.
ANOTHER STORM SYSTEM WILL BRING PRECIPITATION TO THE REGION LATE
SUNDAY INTO MONDAY. WITH WARMER AIR EXPECTED ALOFT...PRECIPITATION
WITH THIS SYSTEM WILL BEGIN AS SNOW OR A WINTRY MIX...AND PERHAPS CHANGING
TO RAIN IN SOME AREAS. PRECIPITATION AMOUNTS ARE STILL UNCERTAIN
WITH THIS SYSTEM.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WARNING UNTIL 10 AM EST FRIDAY FOR CTZ001-013.
NY...WINTER STORM WARNING UNTIL 10 AM EST FRIDAY FOR NYZ038>041-043-
047>054-058>061-063>066-082>084.
WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR NYZ032-033-
042.
WIND CHILL WARNING FROM 7 PM THIS EVENING TO 11 AM EST FRIDAY
FOR NYZ032-033-042.
MA...WINTER STORM WARNING UNTIL 10 AM EST FRIDAY FOR MAZ001-025.
VT...WINTER STORM WARNING UNTIL 10 AM EST FRIDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...KL/FRUGIS
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA
HYDROLOGY...FRUGIS
Area Forecast Discussion
National Weather Service Lincoln IL
958 AM CST Thu Jan 2 2014
.DISCUSSION...
ISSUED 956 AM CST Thu Jan 2 2014
Have allowed the winter weather advisory to expire across eastern
Illinois. Still seeing some visibilities from 1 to 2 miles at
times, but several reports of unknown precipitation on automated
observations are likely implying areas of blowing snow.
Main concern the remainder of the day will be with lake effect
snow. Radar returns over central Illinois have been increasing the
last few hours as moisture is advected in from southern Lake
Michigan. Latest RAP model shows the broader stream of lake effect
snow in northeast Illinois becoming more focused this afternoon
and pushing southward toward Champaign and Danville as the wind
over the lake become more north-northeast. Have maintained 30-40
percent PoP`s in the far northeast CWA into the afternoon, but
will have to watch this closely as the RAP suggests another 1-2
inches may not be out of the question in those areas with this
type of fetch. Over the remainder of the forecast area,
precipitation should start taping off to flurries and end from
west to east.
Geelhart
&&
.AVIATION...
ISSUED 521 AM CST Thu Jan 2 2014
Snow in process of ending at KDEC and will likely end at KCMI by
14z as low pressure over southern Indiana continues moving away
from central Illinois. MVFR and occasional IFR Cigs will likely
persist even though associated mid-level trough moves across
Illinois around midday. Northeast flow will likely produce lake
effect snows over northeast Illinois and the moisture along with
occasional reductions in visibilities will likely reach as far
south as KBMI, KDEC, and of course KCMI. Will keep MVFR Cigs at
KPIA and KSPI without the snow shower threat.
Clearing is finally expected in the 02-05z window from west to
east as the surface high reaches central Illinois. Gusty north
winds today should diminish this evening.
Barker
&&
.PREV DISCUSSION...
ISSUED 330 AM CST Thu Jan 2 2014
SHORT TERM...Today through Sunday night
Winter will keep a tight grip over central and southeast IL during
the next week with arctic air masses visiting the region into the
middle of next week along with a couple of weather systems
bringing more snow. Will expire the winter weather advisory along
and northwest of I-55 with forecast package at 4 am and continue
the winter wx advisory until 9 am for east central and southeast IL.
Snowfall total have generally averaged 2-3 inches across central
IL with lesser amounts in our far southeast counties where mixed
precipitation occurred since it begin late Wed evening, plus a dry
slot in that area too keeping precipitation lighter. Still have
band of light snow from I-55 southeast which HRRR diminishes from
NW to SE through 15Z/9 am. Up to another inch of snow possible
east of I-55 with 1-2 inches more snow east of I-57. Gusty NNW
winds today to cause some low drifting across east-west roads.
Elongated 1013 mb low pressure from southern Indiana into NW TN
early this morning to eject quickly to the mid Atlantic coast by
sunset and produce a winter storm over the Northeast States into
Friday. Scattered flurries over even a few light snow showers
possible over eastern IL this afternoon especially over east
central IL but any additional snow accumulations should be
confined NE of our area closer to the Great Lakes region. Highs
today range from 10-15F over the IL river valley, to the low to
mid 20s in southeast IL.
Will issue a wind chill advisory along and NW of a Rushville to
Bloomington/Normal line tonight and Friday morning for wind chills
getting down to 15-20 below zero. 1037 mb arctic high pressure
over the eastern Dakotas and NW MN to settle into the mid MS
valley Friday morning and bring very cold temps back into the
region. Clouds to decrease from west to east during tonight and
winds to also diminish allowing temps to drop into the single
digits below zero over central IL with Galesburg 10 below or even
colder. High pressure drifts east into the mid Atlantic states by
Friday evening with increasing south winds and fair amount of
sunshine but still cold highs in the upper teens and lower 20s
with fresh snow cover. Breezy south winds continue Sat with milder
temps in the low to mid 30s. Also have 20-40% chance of light snow
from I-55 NW during Sat afternoon with next wx system approaching.
Strong upper level trof to dig into the Midwest by Sunday with low
pressure ejecting NE from the southern plains into the eastern
great lakes region as it deepens. Snow to develop across central
IL Sat night and continue Sunday with be heaviest in southeast IL
where several inches of snow possible. Areas NW by the IL river
valley appear to be on NW fringe of this storm system with lighter
snow amounts. Snow to diminish during Sunday night as storm system
pulls away.
LONG TERM...Monday through Wednesday night
The coldest air of the season still slated to arrive early next
work with from Sunday night through Tue night with subzero lows
returning to central and even southeast IL by Monday night with
northern areas 10-15 below zero. Wind chills Monday night into Tue
morning to get to 20-35 below zero and coldest from I-74 north.
Flurries possible over eastern IL Monday with deep upper level
trof in place. Then next weather system appears to arrive by Wed
afternoon into Thu with next chance of snow with light snow
accumulations possible then. Models trending upward with temps
later next week as upper level heights rise, but skeptical about
too fast of warmup with snow pack in place.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY from 6 PM this evening to Noon CST Friday
FOR ILZ027>031-036>038-040-041.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
600 AM CST THU JAN 2 2014
.DISCUSSION...
352 AM CST
SNOW AND COLD ONCE AGAIN ARE THE REPETITIVE HEADLINES TO THIS
FORECAST...AND IN FACT ARE THE HEADLINES THAT WE HAVE IN EFFECT.
THERE ARE LAKE EFFECT SNOW HEADLINES FOR TODAY ACROSS NORTHEAST IL
AND INTO NORTHWEST INDIANA TONIGHT...WITH SOME ADJUSTMENTS DONE FOR
TIMING AS WELL AS ADDING COUNTIES FOR AN ADVISORY. A WIND CHILL
ADVISORY HAS BEEN ISSUED FOR TONIGHT INTO FRIDAY MORNING FOR MUCH OF
NORTH CENTRAL AND PARTS OF NORTHEAST IL.
THE MASSIVE UPPER LEVEL TROUGH AND ITS EXPANSIVE COLD DEEP AIR
/500MB TEMPS NEARING -40C IN THE GREAT LAKES REGION/ REMAIN
ESTABLISHED OVER THE AREA. THIS IS EVEN SEEN ON THE HEMISPHERIC
WATER VAPOR IMAGERY THIS MORNING WITH A VERY EVIDENT DEEP ROSBY WAVE
CENTERED FROM HUDSON BAY TO GREENLAND AND EXTENDING ACROSS
CENTRAL/EASTERN NORTH AMERICA. PRONOUNCED JET AND UPPER SHORT WAVE
IS ROUNDING THE BASE OF THIS TROUGH ACROSS THE LOWER OHIO VALLEY
EARLY THIS MORNING. THIS WAS THE MAIN CAUSE OF OUR SNOW YESTERDAY
AND THAT HAS ALL BUT SHIFTED EAST OUT OF THE AREA EARLY THIS
MORNING...SO WILL BE ABLE TO LET THE WINTER WEATHER ADVISORY END AT
6 AM.
LOW PRESSURE OF 1013MB IS DEEPENING ACROSS TENNESSEE EARLY THIS
MORNING AND THAT WILL FURTHER DO SUCH INTO THE MID-ATLANTIC BY EARLY
EVE. WITH THE STRONG ARCTIC HIGH BUILDING INTO THE PLAINS...THIS
OVERALL PRESSURE EVOLUTION WILL FAVOR GRADUALLY VEERING WINDS ACROSS
THE LAKE. THIS SLOW VEERING WILL LIKELY HELP TO KEEP A MESOSCALE LOW
PRESSURE TROUGH/CONVERGENCE AXIS INTACT ACROSS THE FAR WESTERN PART
OF THE LAKE THROUGH THE MORNING. THIS AXIS EARLY THIS MORNING IS
ABOUT 35 MILES INLAND ACROSS NORTHEAST IL...BUT WILL SHIFT BACK OUT
TOWARD THE LAKE SHORE...LIKELY TOWARD MIDDAY AND BE THE FOCUS FOR
THE HEAVIEST LAKE EFFECT SNOW AND A LIKELY COUPLE/FEW HOUR PERIOD OF
VERY HEAVY RATES GIVEN THE VERY FAVORABLE PARAMETERS. THESE INCLUDE
STRONG LAKE-INDUCED INSTABILITY IN EXCESS OF 500 J/KG...THIS
INSTABILITY MAINLY COLLOCATED WITH SUPERSATURATION WITH RESPECT TO
ICE AND WITHIN THE DENDRITIC GROWTH AREA...AND CLOUD DEPTHS OF
9-10KFT. ALL THIS HAS BEEN CONSISTENTLY SHOWN BY THE NAM AND LOCAL
ARW.
PRIOR TO THIS AXIS...GENERAL ONSHORE FLOW INTO NORTHEAST IL HAS
ENOUGH INSTABILITY WITH IT TO BE DEVELOPING WIDESPREAD LAKE EFFECT
SNOW SHOWERS THIS MORNING...AND THESE ACTUALLY EXTEND AS FAR WEST IN
ILLINOIS AS ROCHELLE AND MENDOTA! A LONGER FETCH OF INSTABILITY IS
GRADUALLY WORKING INTO LAKE COUNTY IL FROM THE NORTH AND BASED ON
OBSERVATIONS OF LOWERING VISIBILITIES TO AT OR UNDER A
MILE...ACCUMULATIONS OF AROUND ONE HALF INCH PER HOUR WILL SLOWLY
SPREAD SOUTH. SO GIVEN THAT SNOW SHOWERS ARE ALREADY ONGOING WITH
PARAMETERS ONLY BETTERING...SEE NO REASON SNOW SHOWERS WILL NOT STOP
FOR NORTHEAST IL UNTIL THE FLOW TURNS OFFSHORE. THE HEAVIEST SNOW
AGAIN WILL BE CONFINED TO NEAR THAT CONVERGENT AXIS AND USING OUR
LOCAL 8KM ARW...THAT LOOKS TO LINE ITSELF INTO DOWNTOWN CHICAGO
DURING THE EARLY TO MID AFTERNOON...BEFORE SHIFTING EASTWARD INTO
NORTHWEST IN. THIS TIMING OF THE PROBABLE HEAVIEST RATES AND
DURATION IN WHICH THEY LAST...WILL LIKELY BE DEPENDENT ON IF A
MESOSCALE CIRCULATION CAN REMAIN INTACT OVER THE FAR SOUTHERN PART OF
THE LAKE TOO...BASICALLY SLOWLY THAT EASTWARD PROGRESSION. THE
LONGER THAT DOES SUCH...THE MORE PROBABLE THAT SOME CORRIDOR OF THE
LAKE EFFECT WARNING WILL REALIZE 6 OR MORE...POSSIBLY EVEN 8-10
INCHES OF SNOW. THE CONVERGENCE BEGINS TO WEAKEN LATE THIS EVENING
INTO NORTHWEST INDIANA AS IT CONTINUES TO PIVOT EAST...SO THAT
RESULTS IN SNOW ENDING FROM WEST TO EAST ACROSS ADJACENT COUNTIES TO
SOUTHERN LAKE MICHIGAN.
MODEL GUIDANCE REMAINS IN STRONG AGREEMENT WITH ANTICYCLONIC FLOW IN
THE LOW-LEVELS AND SUPPRESSION ALOFT DISSIPATING CLOUDS QUICKLY FROM
WEST TO EAST ACROSS NORTHERN IL LATE THIS AFTERNOON AND THIS EVE.
RADIATIONAL COOLING...HIGHLY ANOMALOUS COLD ATMOSPHERIC AIR...SLOWLY
DECREASING FLOW...AND A FRESH SNOWPACK ALL LOOK TO STILL COLLOCATE
FOR A VERY CHILLY NIGHT. HAVE MINS STILL IN THE -11 TO -18 ARENA
ACROSS ALL OF NORTH CENTRAL IL. HAVE HOISTED A WIND CHILL ADVISORY
AS WINDS WILL MAINTAIN ENOUGH FLOW TO MAKE IT DANGEROUS FOR ANY
PROLONGED EXPOSE SKIN.
FOR THIS WEEKEND WE CONTINUE TO WATCH A SYSTEM OF INTEREST. THE NEXT
IN A SERIES OF COLD FRONTS IS EXPECTED TO PASS SATURDAY AFTERNOON
WITH THE CHANCE FOR LIGHT SNOW. THE SLOWER EC HAS BEEN FOLLOWED
WHICH KEEPS THIS CHANCE OF SNOW AREAWIDE MAINLY DURING THE LATE
AFTERNOON AND NIGHT. AS THE NEXT UPPER TROUGH DEEPENS TO OUR
WEST...MUCH LIKE YESTERDAY...THAT WILL ENHANCE THE BAROCLINIC ZONE
OVER THE REGION POTENTIALLY PROVIDING FOR A FOCUS FOR SNOW LATER
SATURDAY NIGHT INTO SUNDAY. DO HAVE SOME LIKELY POPS IN THE
SOUTHEAST FORECAST AREA...BUT KNOWING THAT SHIFTS ARE INEVITABLE
WITH THIS HAVE NOT TRIED TO GET TOO FANCY. AT THIS TIME IT APPEARS
CHICAGO MAY BE GRAZED WITH THIS.
MTF
MONDAY THROUGH WEDNESDAY...
MAJOR ARCTIC BLAST ARRIVES EARLY MONDAY MORNING...WITH THE LATEST
GUIDANCE SHOWING NO SIGNS OF BACKING OFF ON THE DANGEROUSLY COLD
LOWS AND HIGH TEMPS FOR THE THE MON/TUE TIME FRAME.
ENSEMBLES FOR OVER A WEEK NOW HAVE INDICATED AN ARCTIC BLAST
ARRIVING FOR THE START OF NEXT WEEK...AND THIS CONTINUES TO BE THE
THEME. THE 500MB TROUGH AXIS ARRIVES OVER THE GREAT LAKES REGION
MON...AND WITH WEAK RIDGING OVER THE WESTERN ATLANTIC OCEAN
STRETCHING NORTH THROUGH THE CANADIAN MARITIME. THIS RIDGING WILL
LIKELY SLOW THE FORWARD PROGRESSION TO THE TROUGH AXIS...ALLOWING IT
TO LINGER LONGER OVER THE GREAT LAKES INTO TUE. THEN HEADING INTO
WED THE RIDGING OVER THE WESTERN ATLANTIC BEGINS TO PUSH
EAST...WHICH WILL ALLOW FOR A RELATIVELY MORE FLUID ATMOSPHERE AND
THE TROUGH AXIS WILL DRIFT EAST/NORTHEAST TOWARDS NEW ENGLAND.
AS PREVIOUSLY NOTED ABOUT THE COLD AIR...ENSEMBLES FOR NUMEROUS DAYS
HAVE BEEN PAINTING A HIGH CONFIDENCE THAT AT 850MB TEMPS BY EARLY
MON WILL BE ARND -24 TO -28 DEG C...WITH A POCKET OF -30 DEG C JUST
NORTH OF THE FORECAST AREA INTO CENTRAL/NORTHERN WISC. WITH THE SLOW
FORWARD PROPAGATION TO THE MID-LVL TROUGH...THIS WILL LIKELY KEEP
THE POTENT THERMAL TROUGH OVERHEAD INTO TUE. CLOSER TO THE SFC
RIDGING IS EXPECTED TO PUSH IN BEHIND THE ARCTIC FRONTAL BOUNDARY
AND PROVIDE RELATIVELY LITTLE IN THE WAY OF PRECIP TO THE FORECAST
AREA MON/TUE. UNFORTUNATELY WITH HOW COLD TEMPS WILL BE ALOFT AND A
THICK BLANKET OF SNOW...SFC TEMPS WILL EASILY HOLD WELL BELOW ZERO
FOR HIGHS BOTH MON/TUE. AT THIS TIME HIGH TEMPS MAY STRUGGLE ON BOTH
DAYS TO REACH -5 DEG F...WITH POSSIBLY A FEW LOCATIONS IN OUR
WESTERN CWFA STRUGGLING TO REACH -10 DEG C MON AFTN.
DEPENDING ON CLOUD COVER...OVERNIGHT LOWS COULD EASILY APPROACH
RECORD LOWS AT -15 TO -20 DEG F IN THIS TIMEFRAME. THE COMBINATION
OF DANGEROUSLY COLD SFC TEMPS...AND A GRADIENT PRODUCING BREEZY
CONDITIONS...WILL SET THE STAGE FOR WIND CHILL VALUES LIKELY TO
EXCEED -30 BELOW AND POSSIBLY APPROACH -40 DEG MON NGT. THE
GRADIENT SLACKENS FOR TUE NGT...HOWEVER WIND CHILL VALUES WILL ONCE
AGAIN APPROACH -20 TO -30 DEG F.
THEN TOWARDS THE MIDDLE OF NEXT WEEK THE TROUGH AXIS PIVOTS
EAST...WITH FLOW TURNING SOUTH/SOUTHWEST AND ADVECTING MUCH WARMER
AIR INTO THE REGION. ENSEMBLES HAVE CONTINUED TO INDICATE RELATIVELY
HIGH CONFIDENCE IN THE LONGER TERM PERIODS...WITH A MID-LVL TROUGH
DIGGING INTO THE SOUTHERN PLAINS AND POSSIBLY LEADING TO YET ANOTHER
ACTIVE PERIOD OF WEATHER FOR THE MIDDLE OF NEXT WEEK.
CONFIDENCE IN TEMPS MON/TUE...HIGH.
CONFIDENCE IN WIND CHILL VALUES MON/TUE...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 12Z...
* CIG AND VSBY TRENDS AND SNOW AMOUNTS RELATED TO LAKE EFFECT
SNOW BAND.
* WINDS TURNING FROM NORTHEAST TO NORTH NORTHWEST.
LENNING
//DISCUSSION...UPDATED 12Z...
A PRONOUNCED BAND OF LAKE EFFECT SNOW DEVELOPED DURING THE
PREDAWN HOURS AND WAS POSITIONED OVER THE CHICAGO METRO AREA
AROUND DAYBREAK. FLIGHT CONDITIONS WILL LIKELY REMAIN IFR THIS
MORNING DUE MAINLY TO VSBY RESTRICTIONS BUT PERIODS OF IFR CIGS
ARE ALSO POSSIBLE. DESPITE THE PERSISTENCE OF THIS BAND...HAVE
MOSTLY BEEN SEEING MVFR VSBYS WITH OCCASIONAL IFR...SO ELECTED TO
LEAN TOWARD THAT TREND IN LATEST UPDATES RATHER THAN MAINTAINING
THE LIFR FROM EARLIER FORECASTS. THIS DOES NOT MEAN LIFR IS
COMPLETELY OUT OF THE QUESTION...JUST THAT IT IS NOT EXPECTED TO
BE THE PREVAILING CONDITION FOR AN EXTENDED PERIOD OF TIME.
ACCUMULATING SNOW STILL IS EXPECTED TO WRAP UP BY MID AFTERNOON AT
THE ORD/MDW TERMINALS AS WINDS TURN NORTHWEST AND THE BAND SLIDES
SOUTH. FLURRIES ARE POSSIBLE INTO THE EVENING...THEN HIGH
PRESSURE MOVES INTO THE AREA TONIGHT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 12Z...
* HIGH CONFIDENCE OF IFR VSBYS THIS MORNING. MEDIUM CONFIDENCE OF
SEEING MORE MVFR THAN LIFR.
* MEDIUM CONFIDENCE IN CEILING TRENDS...AGAIN MAINLY MVFR.
* MEDIUM TO HIGH CONFIDENCE IN WIND TRENDS.
LENNING
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW SHOWERS ARRIVE AFTERNOON...MVFR/IFR LIKELY.
SUNDAY...CHANCE SNOW SHOWERS AND MVFR/IFR.
MONDAY AND TUESDAY...BREEZY AND VFR...SOME MVFR POSSIBLE MONDAY.
WEDNESDAY...SNOW AND IFR POSSIBLE.
LENNING
&&
.MARINE...
326 AM CST
MAIN CONCERN IS STRONG LOW PRESSURE PASSING NORTH OF THE LAKES
FRIDAY NIGHT. LATEST MODELS CONTINUE THE TREND OF INCREASING WINDS
AND GUSTS FRIDAY NIGHT...SO ELECTED TO REPLACE THE GALE WATCH WITH
A STORM WATCH. REGARDLESS OF THE EXACT TRACK AND STRENGTH OF THE
LOW...FEEL FAIRLY CONFIDENT OF SEEING AT LEAST A PERIOD OF STORM
FORCE GUSTS...BUT NOT QUITE CONFIDENT ENOUGH YET TO GO WITH THE
WARNING. THESE STORM FORCE WINDS WOULD BE PRECEEDED BY GALES
FRIDAY AFTERNOON AND FOLLOWED BY GALES SATURDAY...BUT WILL CARRY
JUST A STORM WATCH FOR THE ENTIRE PERIOD TO AVOID COMPLICATING THE
HEADLINES.
IN THE NEARSHORE...GALES LIKELY WILL DEVELOP LATE FRIDAY INTO
SATURDAY DURING THE SAME PERIOD AS THE STORM FORCE WINDS IN THE
OPEN WATERS. SMALL CRAFT ADVISORIES CURRENTLY IN EFFECT DO LOOK
LIKE THEY CAN BE DROPPED FOR A SHORT TIME EARLY ON FRIDAY BEFORE
CONDITIONS RAPIDLY INCREASE AGAIN. TO DRAW ATTENTION TO THE SHORT
BREAK BEFORE THE NEW SYSTEM APPROACHING FRIDAY...AND TO AVOID
RUNNING THE HEADLINES TOGETHER...ELECTED TO HOLD OFF ON ISSUING A
GALE WATCH AT THIS TIME BUT DID MENTION IT IN THE FORECAST TEXT.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...LAKE EFFECT SNOW WARNING...ILZ006 UNTIL 3 PM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY
TO 10 AM FRIDAY.
LAKE EFFECT SNOW WARNING...ILZ014 UNTIL 6 PM THURSDAY.
LAKE EFFECT SNOW ADVISORY...ILZ013-ILZ022 UNTIL 6 PM THURSDAY.
IN...LAKE EFFECT SNOW WARNING...INZ001 UNTIL MIDNIGHT FRIDAY.
LAKE EFFECT SNOW ADVISORY...INZ002...3 PM THURSDAY TO 4 AM
FRIDAY.
LM...STORM WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON FRIDAY TO 4 PM
SATURDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 4 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 9 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
527 AM CST Thu Jan 2 2014
.DISCUSSION...
ISSUED 330 AM CST Thu Jan 2 2014
SHORT TERM...Today through Sunday night
Winter will keep a tight grip over central and southeast IL during
the next week with arctic airmasses visiting the region into the
middle of next week along with a couple of weather systems
bringing more snow. Will expire the winter weather advisory along
and northwest of I-55 with forecast package at 4 am and continue
the winter wx advisory until 9 am for eastcentral and southeast IL.
Snowfall total have generally averaged 2-3 inches acorss central
IL with lesser amounts in our far southeast counties where mixed
precipitation occurred since it begin late Wed evening, plus a dry
slot in that area too keeping precipitation lighter. Still have
band of light snow from I-55 southeast which HRRR diminishes from
nw to se through 15Z/9 am. Up to another inch of snow possible
east of I-55 with 1-2 inches more snow east of I-57. Gusty nnw
winds today to cause some low drifting across east-west roads.
Elongated 1013 mb low pressure from southern Indiana into NW TN
early this morning to eject quickly to the mid Atlantic coast by
sunset and produce a winter storm over the Northeast States into
Friday. Scattered flurries over even a few light snow showers
possible over eastern IL this afternoon especially over east
central IL but any additional snow accumulations should be
confined ne of our area closer to the Great Lakes region. Highs
today range from 10-15F over the IL river valley, to the low to
mid 20s in southeast IL.
Will issue a wind chill advisory along and nw of a Rushville to
Bloomington/Normal line tonight and Friday morning for wind chills
getting down to 15-20 below zero. 1037 mb arctic high pressure
over the eastern Dakotas and nw MN to settle into the mid MS
valley Friday morning and bring very cold temps back into the
region. Clouds to decrease from west to east during tonight and
winds to also diminish allowing temps to drop into the single
digits below zero over central IL with Galesburg 10 below or even
colder. High pressure drifts east into the mid Atlantic states by
Friday evening with increaing south winds and fair amount of
sunshine but still cold highs in the upper teens and lower 20s
with fresh snow cover. Breezy south winds continue Sat with milder
temps in the low to mid 30s. Also have 20-40% chance of light snow
from I-55 nw during Sat afternoon with next wx system approaching.
Strong upper level trof to dig into the Midwest by Sunday with low
pressure ejecting ne from the southern plains into the eastern
great lakes region as it deepens. Snow to develop across central
IL Sat night and continue Sunday with be heaviest in southeast IL
where several inches of snow possible. Areas nw by the IL river
valley appear to be on nw fringe of this storm system with ligher
snow amounts. Snow to diminish during Sunday night as storm system
pulls away.
LONG TERM...Monday through Wednesday night
The coldest air of the season still slated to arrive early next
work with from Sunday night through Tue night with subzero lows
returning to central and even southeast IL by Monday night with
northern areas 10-15 below zero. Wind chills Monday night into Tue
morning to get to 20-35 below zero and coldest from I-74 north.
Flurries possible over eastern IL monday with deep upper level
trof in place. Then next weather system appears to arrive by Wed
afternoon into Thu with next chance of snow with light snow
accumulations possible then. Models trending upward with temps
later next week as upper level heights rise, but skeptical about
too fast of warmup with snow pack in place.
07
&&
.AVIATION...
ISSUED 521 AM CST Thu Jan 2 2014
Snow in process of ending at KDEC and will likely end at KCMI by
14z as low pressure over southern Indiana continues moving away
from central Illinois. MVFR and occasional IFR Cigs will likely
persist even though associated mid-level trough moves across
Illinois around midday. Northeast flow will likely produce lake
effect snows over northeast Illinois and the moisture along with
occasional reductions in visibilities will likely reach as far
south as KBMI, KDEC, and of course KCMI. Will keep MVFR Cigs at
KPIA and KSPI without the snow shower threat.
Clearing is finally expected in the 02-05z window from west to
east as the surface high reaches central Illinois. Gusty north
winds today should diminish this evening.
Barker
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY until 9 AM CST this morning FOR
ILZ044>046-054>057-061>063-066>068-071>073.
WIND CHILL ADVISORY from 6 PM this evening to Noon CST Friday
FOR ILZ027>031-036>038-040-041.
WINTER WEATHER ADVISORY until 6 AM CST early this morning FOR
ILZ043-052-053.
&&
$$
AREA FORECAST DISCUSSION
NWS PADUCAH KY
532 AM CST Thu Jan 2 2014
.UPDATE...
UPDATED AVIATION SECTION FOR 12Z TAFS
&&
.SHORT TERM /TODAY THROUGH SATURDAY/...
ISSUED AT 350 AM CST THU JAN 2 2014
In the near term...the minor snow event appears to be on track to
occur in the next several hours. The rain/snow line was located
roughly from Mt. Carmel to Marion IL...southwest to Poplar Bluff
MO at 09z. This transition line will move southeast across all but
the khop area by around 13z. Radar indicates a swath of steady
snow /20 to 25 dbz echoes/ from just se of kstl to kuno as of 09z.
Based on HRRR simulated reflectivity and RAP 1000/500 mb mean
rh fields...this area of steadier snow is likely to lift
east/northeast across the existing winter weather advisory area
this morning. Forecast snowfall amounts appear on track...though
they have been tweaked slightly downward in some areas. Any two
inch amounts would be rather isolated.
Forecast model soundings indicate a very well mixed boundary layer
this afternoon as the arctic air mass settles in. This may
translate to considerable cold air stratocu and flurries. Gusty
winds are also anticipated...with bufkit momentum transfer
algorithm suggesting gusts around 30 mph. Guidance is in
agreement that temperatures will remain steady in the 20s this
afternoon.
The remainder of the forecast is dry...so the main issue is temps.
A 1035 mb surface high will be centered almost directly over the
kstl area at 12z Friday. With clear skies and light
winds...conditions would suggest low temps near zero over snow
cover. The main concern is where the significant snow cover will
exist. Will tweak lows further downward over anticipated snow
cover along and northwest of a line from kmdh to the Wabash
Valley. Elsewhere...model guidance appears reasonable.
Southerly return flow will develop on the back side of the high
Friday. Due to the cold start to the day...highs will still not
reach freezing despite abundant sunshine. Increasing southwest
low level flow Friday night and Saturday will eventually bring
temps close to climo ahead of the next arctic front.
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY NIGHT/...
ISSUED AT 350 AM CST THU JAN 2 2014
The good news is that the medium range models are in very good
agreement throughout this extended forecast period. The bad news is
that they are advertising what could be a significant winter storm
over much of the area Saturday night and Sunday, followed by an
Arctic outbreak of an insane magnitude. Much of the area could see
some of the coldest air ever recorded, and that includes Evansville
with its longer period of record.
By 12Z Monday morning, the 00Z ECWMF and GFS have a 4950M 500mb low
near the east side of Lake Superior with an intense trough running
from the east slope of the Rockies through the northern Gulf Coast
States and then up the entire east coast. This will bring 850mb
temperatures in the -20F to -30F range to our region, which will
likely lead to surface temperatures that do not climb above zero in
the north Monday. The coldest high temperature ever recorded for any
day at Evansville has been -3F, so all time records will be in
jeopardy. The other concern is that winds will not be light, so wind
chills will be -10F to -20F for portions if not all of the area
Sunday night into Tuesday.
As the flow aloft begins to amplify, the models bring a lead
short-wave trough eastward through the area with a significant
surface system Saturday night through Sunday. QPF with this system
is near three quarters of an inch, and portions of southeast
Missouri, southern Illinois and possibly southwest Indiana may see
most of that as snow. Of course it will depend on the location, and
movement of the surface freezing line, which the ECMWF and GEM try
to hold up over west Kentucky and southwest Indiana well into
Sunday. The GFS is a bit faster with the entire system, and is most
agressive with the cold air. The potential exists for significant
accumulations of snow over much of the area. And with the Arctic
surge occurring late Sunday and Sunday night, any ice or snow will
be difficult to remove.
The combination of the initial winter storm and the eventual Arctic
airmass could snarl the region for much of next week. Will not issue
a Special Weather Statement for this extreme winter weather outbreak
at this time due to the ongoing Winter Weather Advisory event.
However, would expect one from the day shift after this morning`s
system has passed.
Some moderation will occur heading into Wednesday of next week,
according to the GFS and ECMWF, but warm advection on the back side
of the departing Arctic surface high will result in a good chance of
wintry precipitation. Added small pops for most of the area
Wednesday, and good chances for Wednesday night. This will be more
of a warm frontal evolution with snow becoming sleet and then
possibly rain/freezing rain through the event. For now just kept it
as a snow/sleet mix given the extremely cold airmass the system will
have to erode. The models keep southwest flow aloft through the end
of the week and there does not seem to be any fresh cold airmass to
move into the region, so the cold spell should be over by the end of
next week.
&&
.AVIATION...
ISSUED AT 532 AM CST THU JAN 2 2014
Strong cold front roughly along a KOWB to KCEY /Murray KY/ line at
11z will sweep southeast...quickly followed by northwest winds
gusting to 30 knots. An area of snow behind the front contains a
narrow band of ifr vsbys from KPAH to the Wabash Valley. There are
also ifr cigs along and immediately behind the front. By late this
morning...mvfr cigs are anticipated at all sites. There may be some
lingering patches of mvfr vsbys as late as 18z in KEVV/KOWB
areas...then vfr vsbys are expected at all sites for the remainder
of the taf period. Clearing skies and diminishing winds are expected
by 06z tonight as high pressure builds into the Mississippi Valley.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
KY...WINTER WEATHER ADVISORY until Noon CST today FOR KYZ014-018-019.
MO...WINTER WEATHER ADVISORY until 8 AM CST this morning FOR MOZ076.
IL...WINTER WEATHER ADVISORY until 8 AM CST this morning FOR ILZ075-
076-080>087.
WINTER WEATHER ADVISORY until Noon CST today FOR ILZ077-078.
IN...WINTER WEATHER ADVISORY until Noon CST today FOR INZ081-082-
085>088.
&&
$$
SHORT TERM...MY
LONG TERM....DRS
AVIATION...MY
AREA FORECAST DISCUSSION
NWS BILLINGS MT
901 AM MST THU JAN 2 2014
.UPDATE...
SOMEWHAT EXTENSIVE UPDATE THIS MORNING. ISSUED A WIND ADVISORY FOR
THE BIG TIMBER AREA...WITH SUSTAINED WINDS AROUND 40 MPH...AND
OCCASIONAL GUSTS NEAR 60 MPH INTO FRIDAY....AND INCREASED
ASSOCIATED WINDS TO CORRESPOND TO ADVISORY.
ALSO EXTENDED THE DENSE FOG ADVISORY UNTIL 18Z FOR NORTHERN
ROSEBUD AND CUSTER COUNTIES. OBSERVATION IN MILES CITY ARE STILL
REPORTING 1/4 MILE VISIBILITY...AND SOUNDINGS INDICATE NO
IMPROVEMENT UNTIL LATER THIS MORNING AS WINDS STAY VERY LIGHT.
FINALLY...INCREASED MOUNTAIN POPS SLIGHTLY FOR WESTERN
MOUNTAINS...AS SHORTWAVE THE CROSSING THE REGION IS BRINGING A
BIT MORE PRECIP THERE THAN EXPECTED. CONSIDERED SPREADING SLIGHT
POPS ACROSS THE PLAINS WITH THIS WAVE AS WELL...BUT ANY PRECIP
THAT IS OCCURRING DOES NOT APPEAR TO BE REACHING THE GROUND...AND
SHOULD BE MAINLY FLURRIES AT BEST IF IT WERE TO REACH THE GROUND.
OTHERWISE THE GOING FORECAST APPEARS IN GOOD SHAPE OVERALL. AAG
&&
.SHORT TERM...VALID FOR TDY AND FRI...
WE ISSUED A DENSE FOG ADVISORY FOR PORTIONS OF CUSTER AND ROSEBUD
COUNTIES EARLIER TONIGHT. THE MLS ASOS HAS BEEN CONSISTENTLY AT
1/4 MILE VISIBILITY AND OBSERVATIONS SUGGEST NEAR 100 PERCENT
HUMIDITY ACROSS THE NORTHERN SECTIONS OF EACH COUNTY. SPOTTER
REPORTS WERE THAT THE FOG IS WIDESPREAD AND QUITE DENSE. THIS
ADVISORY WILL GO UNTIL 9 AM AS HRRR REDUCES THE HUMIDITY IN THIS
AREA A COUPLE OF HOURS AFTER SUNRISE.
THE NEXT FORECAST ISSUE TO ADDRESS IS THE WIND IN THE GAP FLOW
LOCATIONS OF LIVINGSTON...NYE AND NEARBY AREAS. PRESSURE
GRADIENTS ARE ALREADY INCREASING ACROSS THIS REGION AND ARE
PROGGED TO CONTINUE THROUGH TONIGHT. WINDS AT LIVINGSTON HAVE BEEN
GUSTING TO NEAR 50 MPH OVERNIGHT ALREADY. DOWNWARD MOMENTUM PEAKS
LATE TONIGHT OVER A VERY IMPRESSIVE PRESSURE GRADIENT. AS COLD
FRONT HITS AREA FROM NW FRIDAY MORNING WE COULD SEE SOME EXCESSIVE
HYBRID TYPE GUSTS AS 55 TO 60 KTS WILL BE JUST OFF THE
GROUND...AND UP TO 70 KTS AT 700MB ACCORDING TO THE WRF. SO
DESPITE THE PRESSURE GRADIENT GOING TO WESTERLY FOR GAP FLOW BY 11
AM FRIDAY...THE THREAT OF HIGH WIND MAY NOT COMPLETELY END.
THEREFORE...WILL UPGRADE HIGH WIND WATCH TO A WARNING FROM 6 AM
TODAY THROUGH 5 PM FRIDAY. THE STRONGEST WINDS SHOULD OCCUR
BETWEEN 6 PM THIS EVENING TO ABOUT 8 AM FRIDAY MORNING.
I AM CONCERNED WE MAY NEED HIGHLIGHTS FOR HARLOWTON/BIG TIMBER
LOCATIONS AS WELL DUE TO INCREASING 700MB WIND SPEEDS BY FRIDAY.
ANY PERIOD OF STRONG WIND LOOKS SHORTLIVED AT BEST AT HARLOWTON.
I HAVE RAISED WINDS SPEEDS IN THESE AREAS AND WILL LET NEXT
ANALYZE ANOTHER ROUND OF DATA...AS MODELS OFTEN FLIP FLOP ON MID
LEVEL WIND SPEEDS CLOSE TO AN EVENT.
TEMPERATURES WILL BE RELATIVELY MILD FRIDAY...BUT HAVE LOWERED
THEM A NOTCH DUE TO CLOUD COVER AND SOME PRECIPITATION FRIDAY
AFTERNOON. I EXPECT A BLUSTERY FRONTAL PASSAGE FOR THE LATTER HALF
OF FRIDAY TO PRODUCE SCATTERED RAIN AND SNOW SHOWERS. WIND WILL BE
WESTERLY AND BRISK AT FIRST PRODUCING A DOWNSLOPE EFFECT IN MANY
AREAS...BUT DECREASE BY EVENING. IN THE MEANTIME...SOME DECENT Q
VECTOR FORCING WILL CONTINUE OVER THE AREA FRIDAY EVENING...SO
THIS MAY BE BEST CHANCE FOR MEASURABLE PRECIPITATION IN THE SHORT
TERM PERIOD. BT
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MODELS CONTINUE TO LINE UP WELL...FORECASTING AN UPPER LEVEL
RIDGE JUST OFF THE PACIFIC COAST ON SATURDAY...WHICH MOVES OVER
THE PACIFIC COAST DURING THE DAY SUNDAY. THIS SETS US UP FOR
HIGHLY AMPLIFIED NW FLOW IN THE WAKE OF THE FRIDAY FROPA AND
ALLOWS A COUPLE OF STRONG SURGES OF ARCTIC AIR TO MOVE INTO THE
REGION OVER THE WEEKEND. EACH OF THESE SURGES WILL INCREASE LOW-
LEVEL FRONTOGENESIS AND STRENGTHEN A LOW LEVEL BAROCLINIC ZONE
ACROSS WESTERN AND CENTRAL AREAS. AT THE SAME TIME...A SERIES OF
SHORTWAVES IS EXPECTED TO MOVE THROUGH THE REGION...HELPING TO
INCREASE PVA AND MID- LEVEL FRONTOGENESIS...AND THE REGION WILL BE
INFLUENCED BY STRONG 300 MB JET ENERGY. THESE FACTORS WILL LEAD TO
ENHANCED LIFT THROUGH THE DENDRITIC GROWTH ZONE...SO PERIODS OF
SNOW ARE LIKELY ACROSS THE REGION...PARTICULARLY WESTERN AND
CENTRAL AREAS...DURING THE DAY SATURDAY...AND AGAIN LATE SATURDAY
NIGHT INTO SUNDAY MORNING. INCREASED PRECIP CHANCES AND SNOW
AMOUNTS TO REFLECT THIS. SIMILAR SCENARIOS IN THE PREVIOUS FEW
WEEKS RESULTED IN SEVERAL INCHES OF SNOW ACROSS WESTERN AND
CENTRAL AREAS. AVERAGE SNOWFALL FROM CURRENT SREF PLUMES IS JUST
OVER 3 INCHES IN THE BILLINGS REGION SATURDAY INTO SUNDAY. THERE
IS GOOD CLUSTERING IN THE 3 TO 5 INCH RANGE...WHICH SEEMS
REASONABLE.
BESIDES THE SNOW...THE OTHER BIG FACTOR WILL BE THE VERY COLD AIR
THAT MOVES BACK INTO THE REGION. BOTH THE GFS AND ECMWF DROP 850
MB TEMPS TO TO -30C TO -33C RANGE FROM MILES CITY AND BROADUS EAST
DURING THE DAY SUNDAY...SO HIGH TEMPS MAY BE WELL BELOW ZERO ACROSS
THE EAST BY SUNDAY...WITH LOWS COLDER THAN -20F SUNDAY NIGHT.
NW WINDS MAY DROP WIND CHILL VALUES TO BELOW -45F SUNDAY NIGHT IN
PLACES LIKE MILES CITY...BAKER AND EKALAKA.
ECMWF/GFS ARE ALSO VERY SIMILAR IN STARTING TO ERODE THE COLD AIR
OUT OF THE AREA LATE MONDAY AS THE UPPER LEVEL RIDGE CONTINUES TO
MOVE EAST. INCREASING HEIGHTS WILL BRING MODERATING
TEMPERATURES...WITH HIGHS CLIMBING BACK INTO THE 20S AND 30S AGAIN
BY TUESDAY. SOME WEAK SHORTWAVE ACTIVITY MAY BRING THE THREAT OF
SNOW SHOWERS TO THE WESTERN MOUNTAINS LATE TUESDAY INTO
WEDNESDAY...BUT MODELS DIFFER ON TIMING AND STRENGTH OF THE
SHORTWAVES. STC
&&
.AVIATION...
AREAS OF FOG AND LOW CEILINGS WILL CONTINUE TO PRODUCE VLIFR TO
IFR CONDITIONS INTO LATE MORNING ACROSS THE EASTERN HALF OF THE
REGION. EXPECT CONDITIONS TO BE AT OR BELOW AIRPORT MINIMUMS AT
MILES CITY THROUGH 17Z. FLIGHT CONDITIONS ACROSS THE EAST ARE
EXPECTED TO GRADUALLY IMPROVE TO VFR BY 18Z. STRONG SW WINDS WILL
CONTINUE ACROSS THE WEST TODAY...WITH GUSTS OVER 50 KTS AT TIMES
IN THE LIVINGSTON AREA BEGINNING BY MID MORNING AND GUSTS OVER 40
KTS AT TIMES NEAR BIG TIMBER. RICHMOND
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 042 037/043 017/024 007/009 912/009 005/034 017/035
0/N 03/W 44/S 44/S 11/B 12/J 21/B
LVM 046 042/044 015/022 006/013 906/018 010/035 019/035
0/N 03/W 44/S 43/S 11/B 12/J 21/B
HDN 039 024/042 012/022 003/007 916/007 002/028 015/033
0/B 04/W 54/S 44/S 11/B 12/J 21/E
MLS 032 025/039 005/015 904/903 921/903 908/016 007/025
0/B 04/W 43/S 43/S 11/I 12/J 11/E
4BQ 035 025/042 011/017 000/002 918/002 905/022 011/030
0/B 04/W 52/S 44/S 11/B 10/B 11/E
BHK 029 023/040 006/012 908/906 922/906 913/014 001/023
0/E 04/W 52/S 42/S 11/I 11/B 11/E
SHR 040 025/045 012/021 004/009 915/010 003/031 013/032
0/B 02/W 53/S 44/S 11/B 10/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...DENSE FOG ADVISORY IN EFFECT UNTIL 11 AM MST THIS MORNING FOR
ZONES 31-32.
WIND ADVISORY IN EFFECT UNTIL 5 PM MST FRIDAY FOR ZONE 41.
HIGH WIND WARNING IN EFFECT UNTIL 5 PM MST FRIDAY FOR ZONES
65-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS BILLINGS MT
312 AM MST THU JAN 2 2014
.SHORT TERM...VALID FOR TDY AND FRI...
WE ISSUED A DENSE FOG ADVISORY FOR PORTIONS OF CUSTER AND ROSEBUD
COUNTIES EARLIER TONIGHT. THE MLS ASOS HAS BEEN CONSISTENTLY AT
1/4 MILE VISIBILITY AND OBSERVATIONS SUGGEST NEAR 100 PERCENT
HUMIDITY ACROSS THE NORTHERN SECTIONS OF EACH COUNTY. SPOTTER
REPORTS WERE THAT THE FOG IS WIDESPREAD AND QUITE DENSE. THIS
ADVISORY WILL GO UNTIL 9 AM AS HRRR REDUCES THE HUMIDITY IN THIS
AREA A COUPLE OF HOURS AFTER SUNRISE.
THE NEXT FORECAST ISSUE TO ADDRESS IS THE WIND IN THE GAP FLOW
LOCATIONS OF LIVINGSTON...NYE AND NEARBY AREAS. PRESSURE
GRADIENTS ARE ALREADY INCREASING ACROSS THIS REGION AND ARE
PROGGED TO CONTINUE THROUGH TONIGHT. WINDS AT LIVINGSTON HAVE BEEN
GUSTING TO NEAR 50 MPH OVERNIGHT ALREADY. DOWNWARD MOMENTUM PEAKS
LATE TONIGHT OVER A VERY IMPRESSIVE PRESSURE GRADIENT. AS COLD
FRONT HITS AREA FROM NW FRIDAY MORNING WE COULD SEE SOME EXCESSIVE
HYBRID TYPE GUSTS AS 55 TO 60 KTS WILL BE JUST OFF THE
GROUND...AND UP TO 70 KTS AT 700MB ACCORDING TO THE WRF. SO
DESPITE THE PRESSURE GRADIENT BECOMING TO WESTERLY FOR GAP FLOW
BY 11 AM FRIDAY...THE THREAT OF HIGH WIND MAY NOT COMPLETELY END.
THEREFORE...WILL UPGRADE HIGH WIND WATCH TO A WARNING FROM 6 AM
TODAY THROUGH 5 PM FRIDAY. THE STRONGEST WINDS SHOULD OCCUR
BETWEEN 6 PM THIS EVENING TO ABOUT 8 AM FRIDAY MORNING.
I AM CONCERNED WE MAY NEED HIGHLIGHTS FOR HARLOWTON/BIG TIMBER
LOCATIONS AS WELL DUE TO INCREASING 700MB WIND SPEEDS. BUT...ANY
PERIOD OF STRONG WIND LOOKS SHORTLIVED AT BEST AT HARLOWTON. I
HAVE RAISED WINDS SPEEDS IN THESE AREAS AND WILL LET NEXT ANALYZE
ANOTHER ROUND OF DATA...AS MODELS OFTEN FLIP FLOP ON MID LEVEL
WIND SPEEDS CLOSE TO AN EVENT.
TEMPERATURES WILL BE RELATIVELY MILD THE NEXT COUPLE OF
DAYS...BUT HAVE LOWERED THEM A NOTCH FRIDAY DUE TO CLOUD COVER AND
SOME PRECIPITATION FRIDAY AFTERNOON. I EXPECT A BLUSTERY FRONTAL
PASSAGE FOR THE LATTER HALF OF FRIDAY TO PRODUCE SCATTERED RAIN
AND SNOW SHOWERS. WIND WILL BE WESTERLY AND BRISK AT FIRST
PRODUCING A DOWNSLOPE EFFECT IN MANY AREAS...BUT DECREASE BY
EVENING. IN THE MEANTIME...SOME DECENT Q VECTOR FORCING WILL
CONTINUE OVER THE AREA FRIDAY EVENING...SO THIS MAY BE BEST CHANCE
FOR MEASURABLE PRECIPITATION IN THE SHORT TERM PERIOD. BT
.LONG TERM...VALID FOR SAT...SUN...MON...TUE...WED...
MODELS CONTINUE TO LINE UP WELL...FORECASTING AN UPPER LEVEL
RIDGE JUST OFF THE PACIFIC COAST ON SATURDAY...WHICH MOVES OVER
THE PACIFIC COAST DURING THE DAY SUNDAY. THIS SETS US UP FOR
HIGHLY AMPLIFIED NW FLOW IN THE WAKE OF THE FRIDAY FROPA AND
ALLOWS A COUPLE OF STRONG SURGES OF ARCTIC AIR TO MOVE INTO THE
REGION OVER THE WEEKEND. EACH OF THESE SURGES WILL INCREASE LOW-
LEVEL FRONTOGENESIS AND STRENGTHEN A LOW LEVEL BAROCLINIC ZONE
ACROSS WESTERN AND CENTRAL AREAS. AT THE SAME TIME...A SERIES OF
SHORTWAVES IS EXPECTED TO MOVE THROUGH THE REGION...HELPING TO
INCREASE PVA AND MID- LEVEL FRONTOGENESIS...AND THE REGION WILL BE
INFLUENCED BY STRONG 300 MB JET ENERGY. THESE FACTORS WILL LEAD TO
ENHANCED LIFT THROUGH THE DENDRITIC GROWTH ZONE...SO PERIODS OF
SNOW ARE LIKELY ACROSS THE REGION...PARTICULARLY WESTERN AND
CENTRAL AREAS...DURING THE DAY SATURDAY...AND AGAIN LATE SATURDAY
NIGHT INTO SUNDAY MORNING. INCREASED PRECIP CHANCES AND SNOW
AMOUNTS TO REFLECT THIS. SIMILAR SCENARIOS IN THE PREVIOUS FEW
WEEKS RESULTED IN SEVERAL INCHES OF SNOW ACROSS WESTERN AND
CENTRAL AREAS. AVERAGE SNOWFALL FROM CURRENT SREF PLUMES IS JUST
OVER 3 INCHES IN THE BILLINGS REGION SATURDAY INTO SUNDAY. THERE
IS GOOD CLUSTERING IN THE 3 TO 5 INCH RANGE...WHICH SEEMS
REASONABLE.
BESIDES THE SNOW...THE OTHER BIG FACTOR WILL BE THE VERY COLD AIR
THAT MOVES BACK INTO THE REGION. BOTH THE GFS AND ECMWF DROP 850
MB TEMPS TO TO -30C TO -33C RANGE FROM MILES CITY AND BROADUS EAST
DURING THE DAY SUNDAY...SO HIGH TEMPS MAY BE WELL BELOW ZERO ACROSS
THE EAST BY SUNDAY...WITH LOWS COLDER THAN -20F SUNDAY NIGHT.
NW WINDS MAY DROP WIND CHILL VALUES TO BELOW -45F SUNDAY NIGHT IN
PLACES LIKE MILES CITY...BAKER AND EKALAKA.
ECMWF/GFS ARE ALSO VERY SIMILAR IN STARTING TO ERODE THE COLD AIR
OUT OF THE AREA LATE MONDAY AS THE UPPER LEVEL RIDGE CONTINUES TO
MOVE EAST. INCREASING HEIGHTS WILL BRING MODERATING
TEMPERATURES...WITH HIGHS CLIMBING BACK INTO THE 20S AND 30S AGAIN
BY TUESDAY. SOME WEAK SHORTWAVE ACTIVITY MAY BRING THE THREAT OF
SNOW SHOWERS TO THE WESTERN MOUNTAINS LATE TUESDAY INTO
WEDNESDAY...BUT MODELS DIFFER ON TIMING AND STRENGTH OF THE
SHORTWAVES. STC
&&
.AVIATION...
AREAS OF FOG AND LOW CEILINGS WILL CONTINUE TO PRODUCE VLIFR TO
IFR CONDITIONS INTO LATE THIS MORNING ACROSS THE EASTERN HALF OF
THE REGION. EXPECT CONDITIONS TO BE AT OR BELOW AIRPORT MINIMUMS
AT KMLS THROUGH 15Z. FLIGHT CONDITIONS ACROSS THE EAST ARE
EXPECTED TO GRADUALLY IMPROVE TO VFR BY 18Z. STRONG SW WINDS WILL
CONTINUE ACROSS THE WEST TODAY...WITH GUSTS OVER 50 KTS AT TIMES
IN THE KLVM REGION BEGINNING BY MID MORNING AND GUSTS OVER 40 KTS
AT TIMES NEAR 6S0. STC
&&
.PRELIMINARY POINT TEMP/POPS...
TDY FRI SAT SUN MON TUE WED
-------------------------------------------------------
BIL 042 037/043 017/024 007/009 912/009 005/034 017/035
0/N 03/W 44/J 44/J 11/B 12/J 21/B
LVM 046 042/044 015/022 006/013 906/018 010/035 019/035
0/N 03/W 44/J 43/J 11/B 12/J 21/B
HDN 039 024/042 012/022 003/007 916/007 002/028 015/033
0/B 04/W 54/J 44/J 11/B 12/J 21/E
MLS 032 025/039 005/015 904/903 921/903 908/016 007/025
0/B 04/W 42/J 43/J 11/I 12/J 11/E
4BQ 035 025/042 011/017 000/002 918/002 905/022 011/030
0/B 04/W 52/J 44/J 11/B 10/B 11/E
BHK 029 023/040 006/012 908/906 922/906 913/014 001/023
0/E 04/W 51/E 42/J 11/I 11/B 11/E
SHR 040 025/045 012/021 004/009 915/010 003/031 013/032
0/B 02/W 53/J 44/J 11/B 10/B 11/B
&&
.BYZ WATCHES/WARNINGS/ADVISORIES...
MT...DENSE FOG ADVISORY IN EFFECT UNTIL 9 AM MST THIS MORNING FOR
ZONES 31-32.
HIGH WIND WARNING IN EFFECT UNTIL 5 PM MST FRIDAY FOR ZONES
65-66.
WY...NONE.
&&
$$
WEATHER.GOV/BILLINGS
AREA FORECAST DISCUSSION
NWS HASTINGS NE
546 AM CST THU JAN 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CST THU JAN 2 2014
MAIN FORECAST CONCERN FOR THE SHORT TERM PERIOD LIES WITH SOME
LIGHT SNOW CHANCES AND TRICKY HIGH TEMPERATURES FOR TODAY.
QUIET CONDITIONS REMAIN IN PLACE ACROSS THE CWA EARLY THIS
MORNING...AND WE CONTINUE TO SIT UNDER NORTHWESTERLY FLOW IN THE
UPPER LEVELS AS A LARGE AREA OF LOW PRESSURE CONTINUES TO SPIN
OVER ERN CANADA...WITH YESTERDAYS SNOW-PRODUCING DISTURBANCE
MOVING INTO THE MIDWEST...WHILE RIDGING REMAINS OFF THE WEST
COAST. A STOUT ~130KT UPPER LEVEL JET STREAK NOSING IN FROM THE
NORTH BEHIND THE TROUGH AXIS...HELPING DRIVE SOME LIGHT
SNOW/FLURRIES...WITH INCREASED RADAR RETURNS JUST NORTH OF THE
CWA. SKIES ACROSS THE CWA CURRENTLY MOSTLY CLOUDY/OVERCAST THANKS
TO A BAND OF MAINLY LOWER LEVEL STRATUS STRETCHED FROM THE NRN
ROCKIES INTO CENTRAL KS. AT THE SURFACE...HIGH PRESSURE DRAPED
GENERALLY THROUGH THE ERN PORTIONS OF THE CENTRAL PLAINS IS
KEEPING WINDS ON THE LIGHT/VARIABLE SIDE...WITH MORE OF A WESTERLY
COMPONENT DEVELOPING ACROSS WRN LOCATIONS.
THIS MORNING...THAT UPPER LEVEL JET STREAK REMAINS IN THE
AREA...AND WILL CONTINUE TO BRING THE POTENTIAL FOR SOME LIGHT
SNOW/FLURRIES TO MAINLY THE NORTHEASTERN HALF OF THE CWA. WITH
UPSTREAM OBS SHOWING VISIBILITIES DROPPING AT TIMES INTO THE 2-3
MILE RANGE...PERHAPS A FEW AREAS COULD MAYBE PICK UP A TENTH OF AN
INCH OR SO OF SNOW ACCUMULATION...SO HAVE SOME LOW POPS GOING.
OTHERWISE THE REST OF THE SHORT TERM REMAINS DRY. KEPT HIGH SKY
COVER VALUES GOING THIS MORNING...BUT SATELLITE IMAGERY SUGGESTS
THE WRN EDGE OF THAT BAND OF CLOUD COVER ISNT FAR OUTSIDE THE WRN
EDGE OF THE CWA...AND MODELS ARENT IN TOO BAD OF AGREEMENT SHOWING
THE HIGHER CLOUD COVER TRANSITIONING TO MAINLY AFFECT THE
NORTHEASTERN HALF OF THE CWA...WITH MORE SUN POTENTIAL FURTHER
SOUTHWEST.
LOOKING AT TEMPERATURES...HIGHS FOR TODAY ARE TRICKY...AND
CONFIDENCE IS NOT HIGH. WHILE WINDS ARE MAINLY ON THE
LIGHT/VARIABLE TO WESTERLY SIDE CURRENTLY...MODELS SHOW THE CWA
BEING AFFECTED BY A BACKDOOR COLD FRONT SLIDING IN FROM THE
NORTH/NORTHEAST THIS MORNING...AND THE POSITION OF THIS FRONT
THROUGH THE DAY WILL HAVE A BIG IMPACT ON WHAT TEMPS GET TO TODAY.
THERE ARE DIFFERENCES BETWEEN MODELS WITH TIMING/LOCATION. LOOKING
AT MIDDAY...THE 07Z HRRR AND 09Z RAP /THE RAP HAS DONE FAIRLY
WELL THE LAST FEW DAYS WITH HIGHS/ SHOW THE FRONT ROUGHLY ALONG A
BBW TO CNK LINE THROUGH THE CWA...VS OTHER MODELS WHICH FURTHER
WEST BY THEN...CLOSER TO A LBF TO RSL LINE. MAYBE NOT A HUGE
DIFFERENCE...BUT THE SLOWER PROGRESS OF THE BOUNDARY...WITH THE
WESTERLY WINDS AHEAD OF THE FRONT...WOULD ALLOW WRN AND POSSIBLY
CENTRAL PORTIONS OF THE CWA /INCLUDING THE TRI CITIES/ TO REACH
HIGHER TEMPS BEFORE THE EASTERLY WINDS ACCOMPANYING THE FRONT TAKE
OVER AND TEMPS DONT REALLY GO ANYWHERE. THIS LOOKS TO BE THE STORY
WITH NERN PORTIONS OF THE CWA...WHICH WILL COME UNDER THE
INFLUENCE OF THOSE E/NERLY WINDS EARLY ON IN THE DAY. DONT WANT TO
COMPLETELY DISCOUNT OR BUY FULLY INTO WHAT THE RAP/HRRR
SUGGEST...SO HIGHS ARE A BLEND...RANGING FROM ARND 10 DEGREES IN
THE NORTHEAST...TO MID 30S IN THE SW. OVERNIGHT LOWS TONIGHT LOOK
TO FALL BACK INTO THE LOW SINGLE DIGITS EAST TO MID TEENS WEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 409 AM CST THU JAN 2 2014
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL
SUGGEST A MID LEVEL SHORT WAVE WILL MOVE FROM THE NORTHWESTERN
CONUS...SOUTHEAST INTO PORTIONS OF THE CENTRAL PLAINS FRIDAY INTO
SATURDAY. THE NAM SUGGESTS A NEARLY CONTINUOUS ~70KT MID LEVEL JET
STREAM AXIS WILL EXTEND FROM COLORADO TO THE GREAT LAKES REGION AT
18Z SATURDAY. THE OPERATIONAL GFS AND EC ON THE OTHER HAND BOTH
SUGGEST A BREAK IN THIS MID LEVEL JET AXIS OVER THE CENTRAL PLAINS
WILL ALLOW THE RIGHT-REAR QUADRANT OF A DEPARTING JET STREAK...AND
THE LEFT-FRONT QUADRANT OF AN INCOMING JET STREAK...TO SET UP FROM
WESTERN KANSAS INTO SOUTHEASTERN NEBRASKA AT 18Z SATURDAY. DPVA
AND MID LEVEL THERMAL ADVECTION AHEAD OF THE INCOMING MID LEVEL
SHORTWAVE DO NOT APPEAR OVERLY STRONG AND THE NAM RESPONDS BY
KEEPING OUR AREA DRY THROUGH THE WEEKEND. THE OPERATIONAL GFS AND
EC ON THE OTHER HAND BOTH SUGGEST ENHANCED OMEGA DUE TO DIRECT AND
INDIRECT THERMAL CIRCULATIONS FROM THE AFOREMENTIONED JET STREAKS
WILL PROMOTE A PERIOD OF LIGHT PRECIPITATION OVER PORTIONS OF OUR
AREA SATURDAY INTO SATURDAY EVENING...PRIMARILY ACROSS OUR SOUTH.
GIVEN THIS...WENT AHEAD WITH LOW POPS ACROSS OUR SOUTH 18Z
SATURDAY THROUGH 06Z SUNDAY ACROSS OUR SOUTH. A SECONDARY MID
LEVEL SHORTWAVE IS THEN EXPECTED TO SWEEP SOUTH/SOUTHEAST ACROSS
PORTIONS OF THE NORTHERN AND CENTRAL PLAINS SUNDAY INTO SUNDAY
NIGHT...WITH ENOUGH DPVA AND MID LEVEL THERMAL ADVECTION FOR LIGHT
PRECIPITATION ACROSS OUR AREA. ALLBLEND RESPONDED BY PRESENTING
~20% POPS TO MUCH OF THE AREA AND THESE POPS WERE LEFT UNCHANGED
FOR THE MOST PART. AN OVERALL LACK IN OMEGA SHOULD THEN PROVIDE
DRY CONDITIONS THROUGH THE REMAINDER OF THE LONG TERM FORECAST
PERIOD.
INCORPORATING THE DRY NAM FORECAST FOR SATURDAY AFTERNOON AND
SATURDAY EVENING...AS WELL AS A BLEND OF THE OPERATIONAL GFS AND
EC...PROVIDES LIQUID PRECIPITATION GENERALLY IN THE 0.01-0.04"
RANGE. SURFACE TEMPERATURES DURING THIS EVENT ARE CURRENTLY
EXPECTED TO RANGE FROM THE UPPER 20S TO AROUND 15...WHICH SUGGESTS
SNOW-WATER RATIOS GENERALLY IN THE 10-20:1 RANGE. THIS PROVIDES
SNOWFALL ACCUMULATION FROM A COUPLE TENTHS OF AN INCH TO PERHAPS
ONE INCH ACROSS OUR SOUTH 18Z SATURDAY THROUGH 06Z SUNDAY.
SNOWFALL RATES ALSO DO NOT LOOK OVERLY IMPRESSIVE SUNDAY INTO
SUNDAY NIGHT WITH PERHAPS ANOTHER INCH OF SNOWFALL ACCUMULATION
POSSIBLE ACROSS MUCH OF THE CWA.
BY FAR THE BIGGEST STORY OF THE LONG TERM FORECAST PERIOD WILL BE
THE VERY COLD TEMPERATURES WHICH LOOK TO INFILTRATE OUR AREA DURING
THE EARLY PART OF NEXT WEEK. WHILE THE COLDEST LOW LEVEL AIRMASS IS
EXPECTED TO RESIDE OVER PORTIONS OF THE UPPER MISSISSIPPI VALLEY
SUNDAY THROUGH TUESDAY...OUR AREA WILL NOT BE SPARED THE AFFECTS
OF THIS FRIGID AIR MASS AS GUIDANCE SUGGESTS SUB-ZERO READINGS
WILL BE REALIZED SUNDAY NIGHT AND MONDAY NIGHT. IN
ADDITION...STRONG LOW LEVEL COLD AIR ADVECTION ON MONDAY WILL
LIKELY KEEP HIGHS IN THE SINGLE DIGITS FOR MOST LOCATIONS ACROSS
THE CWA. THESE COLD TEMPERATURES WILL HELP PROMOTE WIND CHILL
READINGS GENERALLY IN THE -15 TO -25 DEGREE RANGE ACROSS MUCH OF
THE CWA EARLY MONDAY MORNING...WITH WIND CHILL VALUES PERHAPS
APPROACHING -30 ACROSS OUR EXTREME NORTHEAST. WILL GO AHEAD AND
MAINTAIN THE WIND CHILL WORDING IN THE HWO FOR MONDAY MORNING. THE
LOW LEVEL WIND FIELD APPEARS AS THOUGH IT WILL WEAKEN CONSIDERABLY
BY TUESDAY MORNING SO EVEN THOUGH EARLY TUESDAY MORNING LOWS WILL
BE COMPARABLE TO MONDAY...WIND CHILL VALUES ON TUESDAY MORNING DO
NOT APPEAR AS THROUGH THEY WILL DROP BELOW -10 DEGREES.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 538 AM CST THU JAN 2 2014
AN UPPER LEVEL JET STREAK NOSING IN FROM THE NORTH IS BRINGING
SOME LIGHT SNOW/FLURRIES TO THE REGION...BUT AT THIS POINT ANY
ACTIVITY IS EXPECTED TO REMAIN NORTH OF THE TERMINAL AND KEPT ANY
MENTION OUT. MAIN UNCERTAINTY FOR THE PERIOD LIES WITH CLOUD COVER
AND POTENTIAL CEILING RESTRICTIONS. THE TERMINAL IS CURRENTLY
ON THE WRN EDGE OF A BAND OF LOWER LEVEL STRATUS...DECIDED TO KEEP
THE PREVAILING CONDITIONS THROUGH MID MORNING VFR...BUT CANT RULE
OUT CEILINGS ARND 2500FT MOVING BACK IN AND HAVE A TEMPO GROUP
GOING. WHILE WINDS ARE CURRENTLY ON THE LIGHT/VARIABLE SIDE...A
FRONTAL BOUNDARY WILL SLIDE THROUGH THE TERMINAL AREA LATER THIS
MORNING...USHERING IN NORTHEASTERLY WINDS...AND THE POTENTIAL FOR
ANOTHER SHOT OF THAT LOWER LEVEL STRATUS. THIS AFTERNOON AND
THROUGH THE END OF THE PERIOD...CEILINGS ARE EXPECTED TO LIFT AND
CLOUD COVER MAY DIMINISH A BIT...SO HAVE VFR CONDITIONS
GOING...BUT CONFIDENCE REMAINS LOW WITH TIMING.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADO
LONG TERM...BRYANT
AVIATION...ADO
AREA FORECAST DISCUSSION
NWS HASTINGS NE
412 AM CST THU JAN 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CST THU JAN 2 2014
MAIN FORECAST CONCERN FOR THE SHORT TERM PERIOD LIES WITH SOME
LIGHT SNOW CHANCES AND TRICKY HIGH TEMPERATURES FOR TODAY.
QUIET CONDITIONS REMAIN IN PLACE ACROSS THE CWA EARLY THIS
MORNING...AND WE CONTINUE TO SIT UNDER NORTHWESTERLY FLOW IN THE
UPPER LEVELS AS A LARGE AREA OF LOW PRESSURE CONTINUES TO SPIN
OVER ERN CANADA...WITH YESTERDAYS SNOW-PRODUCING DISTURBANCE
MOVING INTO THE MIDWEST...WHILE RIDGING REMAINS OFF THE WEST
COAST. A STOUT ~130KT UPPER LEVEL JET STREAK NOSING IN FROM THE
NORTH BEHIND THE TROUGH AXIS...HELPING DRIVE SOME LIGHT
SNOW/FLURRIES...WITH INCREASED RADAR RETURNS JUST NORTH OF THE
CWA. SKIES ACROSS THE CWA CURRENTLY MOSTLY CLOUDY/OVERCAST THANKS
TO A BAND OF MAINLY LOWER LEVEL STRATUS STRETCHED FROM THE NRN
ROCKIES INTO CENTRAL KS. AT THE SURFACE...HIGH PRESSURE DRAPED
GENERALLY THROUGH THE ERN PORTIONS OF THE CENTRAL PLAINS IS
KEEPING WINDS ON THE LIGHT/VARIABLE SIDE...WITH MORE OF A WESTERLY
COMPONENT DEVELOPING ACROSS WRN LOCATIONS.
THIS MORNING...THAT UPPER LEVEL JET STREAK REMAINS IN THE
AREA...AND WILL CONTINUE TO BRING THE POTENTIAL FOR SOME LIGHT
SNOW/FLURRIES TO MAINLY THE NORTHEASTERN HALF OF THE CWA. WITH
UPSTREAM OBS SHOWING VISIBILITIES DROPPING AT TIMES INTO THE 2-3
MILE RANGE...PERHAPS A FEW AREAS COULD MAYBE PICK UP A TENTH OF AN
INCH OR SO OF SNOW ACCUMULATION...SO HAVE SOME LOW POPS GOING.
OTHERWISE THE REST OF THE SHORT TERM REMAINS DRY. KEPT HIGH SKY
COVER VALUES GOING THIS MORNING...BUT SATELLITE IMAGERY SUGGESTS
THE WRN EDGE OF THAT BAND OF CLOUD COVER ISNT FAR OUTSIDE THE WRN
EDGE OF THE CWA...AND MODELS ARENT IN TOO BAD OF AGREEMENT SHOWING
THE HIGHER CLOUD COVER TRANSITIONING TO MAINLY AFFECT THE
NORTHEASTERN HALF OF THE CWA...WITH MORE SUN POTENTIAL FURTHER
SOUTHWEST.
LOOKING AT TEMPERATURES...HIGHS FOR TODAY ARE TRICKY...AND
CONFIDENCE IS NOT HIGH. WHILE WINDS ARE MAINLY ON THE
LIGHT/VARIABLE TO WESTERLY SIDE CURRENTLY...MODELS SHOW THE CWA
BEING AFFECTED BY A BACKDOOR COLD FRONT SLIDING IN FROM THE
NORTH/NORTHEAST THIS MORNING...AND THE POSITION OF THIS FRONT
THROUGH THE DAY WILL HAVE A BIG IMPACT ON WHAT TEMPS GET TO TODAY.
THERE ARE DIFFERENCES BETWEEN MODELS WITH TIMING/LOCATION. LOOKING
AT MIDDAY...THE 07Z HRRR AND 09Z RAP /THE RAP HAS DONE FAIRLY
WELL THE LAST FEW DAYS WITH HIGHS/ SHOW THE FRONT ROUGHLY ALONG A
BBW TO CNK LINE THROUGH THE CWA...VS OTHER MODELS WHICH FURTHER
WEST BY THEN...CLOSER TO A LBF TO RSL LINE. MAYBE NOT A HUGE
DIFFERENCE...BUT THE SLOWER PROGRESS OF THE BOUNDARY...WITH THE
WESTERLY WINDS AHEAD OF THE FRONT...WOULD ALLOW WRN AND POSSIBLY
CENTRAL PORTIONS OF THE CWA /INCLUDING THE TRI CITIES/ TO REACH
HIGHER TEMPS BEFORE THE EASTERLY WINDS ACCOMPANYING THE FRONT TAKE
OVER AND TEMPS DONT REALLY GO ANYWHERE. THIS LOOKS TO BE THE STORY
WITH NERN PORTIONS OF THE CWA...WHICH WILL COME UNDER THE
INFLUENCE OF THOSE E/NERLY WINDS EARLY ON IN THE DAY. DONT WANT TO
COMPLETELY DISCOUNT OR BUY FULLY INTO WHAT THE RAP/HRRR
SUGGEST...SO HIGHS ARE A BLEND...RANGING FROM ARND 10 DEGREES IN
THE NORTHEAST...TO MID 30S IN THE SW. OVERNIGHT LOWS TONIGHT LOOK
TO FALL BACK INTO THE LOW SINGLE DIGITS EAST TO MID TEENS WEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 409 AM CST THU JAN 2 2014
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL
SUGGEST A MID LEVEL SHORT WAVE WILL MOVE FROM THE NORTHWESTERN
CONUS...SOUTHEAST INTO PORTIONS OF THE CENTRAL PLAINS FRIDAY INTO
SATURDAY. THE NAM SUGGESTS A NEARLY CONTINUOUS ~70KT MID LEVEL JET
STREAM AXIS WILL EXTEND FROM COLORADO TO THE GREAT LAKES REGION AT
18Z SATURDAY. THE OPERATIONAL GFS AND EC ON THE OTHER HAND BOTH
SUGGEST A BREAK IN THIS MID LEVEL JET AXIS OVER THE CENTRAL PLAINS
WILL ALLOW THE RIGHT-REAR QUADRANT OF A DEPARTING JET STREAK...AND
THE LEFT-FRONT QUADRANT OF AN INCOMING JET STREAK...TO SET UP FROM
WESTERN KANSAS INTO SOUTHEASTERN NEBRASKA AT 18Z SATURDAY. DPVA
AND MID LEVEL THERMAL ADVECTION AHEAD OF THE INCOMING MID LEVEL
SHORTWAVE DO NOT APPEAR OVERLY STRONG AND THE NAM RESPONDS BY
KEEPING OUR AREA DRY THROUGH THE WEEKEND. THE OPERATIONAL GFS AND
EC ON THE OTHER HAND BOTH SUGGEST ENHANCED OMEGA DUE TO DIRECT AND
INDIRECT THERMAL CIRCULATIONS FROM THE AFOREMENTIONED JET STREAKS
WILL PROMOTE A PERIOD OF LIGHT PRECIPITATION OVER PORTIONS OF OUR
AREA SATURDAY INTO SATURDAY EVENING...PRIMARILY ACROSS OUR SOUTH.
GIVEN THIS...WENT AHEAD WITH LOW POPS ACROSS OUR SOUTH 18Z
SATURDAY THROUGH 06Z SUNDAY ACROSS OUR SOUTH. A SECONDARY MID
LEVEL SHORTWAVE IS THEN EXPECTED TO SWEEP SOUTH/SOUTHEAST ACROSS
PORTIONS OF THE NORTHERN AND CENTRAL PLAINS SUNDAY INTO SUNDAY
NIGHT...WITH ENOUGH DPVA AND MID LEVEL THERMAL ADVECTION FOR LIGHT
PRECIPITATION ACROSS OUR AREA. ALLBLEND RESPONDED BY PRESENTING
~20% POPS TO MUCH OF THE AREA AND THESE POPS WERE LEFT UNCHANGED
FOR THE MOST PART. AN OVERALL LACK IN OMEGA SHOULD THEN PROVIDE
DRY CONDITIONS THROUGH THE REMAINDER OF THE LONG TERM FORECAST
PERIOD.
INCORPORATING THE DRY NAM FORECAST FOR SATURDAY AFTERNOON AND
SATURDAY EVENING...AS WELL AS A BLEND OF THE OPERATIONAL GFS AND
EC...PROVIDES LIQUID PRECIPITATION GENERALLY IN THE 0.01-0.04"
RANGE. SURFACE TEMPERATURES DURING THIS EVENT ARE CURRENTLY
EXPECTED TO RANGE FROM THE UPPER 20S TO AROUND 15...WHICH SUGGESTS
SNOW-WATER RATIOS GENERALLY IN THE 10-20:1 RANGE. THIS PROVIDES
SNOWFALL ACCUMULATION FROM A COUPLE TENTHS OF AN INCH TO PERHAPS
ONE INCH ACROSS OUR SOUTH 18Z SATURDAY THROUGH 06Z SUNDAY.
SNOWFALL RATES ALSO DO NOT LOOK OVERLY IMPRESSIVE SUNDAY INTO
SUNDAY NIGHT WITH PERHAPS ANOTHER INCH OF SNOWFALL ACCUMULATION
POSSIBLE ACROSS MUCH OF THE CWA.
BY FAR THE BIGGEST STORY OF THE LONG TERM FORECAST PERIOD WILL BE
THE VERY COLD TEMPERATURES WHICH LOOK TO INFILTRATE OUR AREA DURING
THE EARLY PART OF NEXT WEEK. WHILE THE COLDEST LOW LEVEL AIRMASS IS
EXPECTED TO RESIDE OVER PORTIONS OF THE UPPER MISSISSIPPI VALLEY
SUNDAY THROUGH TUESDAY...OUR AREA WILL NOT BE SPARED THE AFFECTS
OF THIS FRIGID AIR MASS AS GUIDANCE SUGGESTS SUB-ZERO READINGS
WILL BE REALIZED SUNDAY NIGHT AND MONDAY NIGHT. IN
ADDITION...STRONG LOW LEVEL COLD AIR ADVECTION ON MONDAY WILL
LIKELY KEEP HIGHS IN THE SINGLE DIGITS FOR MOST LOCATIONS ACROSS
THE CWA. THESE COLD TEMPERATURES WILL HELP PROMOTE WIND CHILL
READINGS GENERALLY IN THE -15 TO -25 DEGREE RANGE ACROSS MUCH OF
THE CWA EARLY MONDAY MORNING...WITH WIND CHILL VALUES PERHAPS
APPROACHING -30 ACROSS OUR EXTREME NORTHEAST. WILL GO AHEAD AND
MAINTAIN THE WIND CHILL WORDING IN THE HWO FOR MONDAY MORNING. THE
LOW LEVEL WIND FIELD APPEARS AS THOUGH IT WILL WEAKEN CONSIDERABLY
BY TUESDAY MORNING SO EVEN THOUGH EARLY TUESDAY MORNING LOWS WILL
BE COMPARABLE TO MONDAY...WIND CHILL VALUES ON TUESDAY MORNING DO
NOT APPEAR AS THROUGH THEY WILL DROP BELOW -10 DEGREES.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1134 PM CST WED JAN 1 2014
PRIMARY FORECAST CONCERN FOR THIS TAF PERIOD LIES WITH CLOUD
COVER. THE NEXT BATCH OF LOWER LEVEL STRATUS HAS MOVED INTO THE
TERMINAL AREA...WITH MODELS SHOWING IT STICKING AROUND FOR A
WHILE. HAVE MVFR CEILINGS GOING INTO THIS AFTERNOON...BUT
CONFIDENCE IN WHEN THOSE CEILINGS WILL LIFT IS NOT HIGH. LOOKING
AT WINDS...SURFACE HIGH PRESSURE SETTLED INTO THE AREA WILL KEEP
WINDS ON THE LIGHT/VARIABLE SIDE THROUGH MID AFTERNOON...BEFORE
E/SERLY WINDS MAKE A RETURN.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADO
LONG TERM...BRYANT
AVIATION...ADO
AREA FORECAST DISCUSSION
NWS RALEIGH NC
940 AM EST THU JAN 02 2014
.SYNOPSIS...A POTENT UPPER LEVEL TROUGH AND ATTENDANT SURFACE LOW
PRESSURE SYSTEM WILL APPROACH THE CAROLINAS FROM THE WEST TODAY. A
STRONG COLD FRONT WILL CROSS CENTRAL NC THIS EVENING. COLD HIGH
PRESSURE WILL BUILD INTO THE REGION IN THE WAKE OF THE FRONT ON
FRIDAY AND FRIDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM THURSDAY...
LIGHT...ISENTROPICALLY DRIVEN PRECIP INLAND OF AN INVERTED COASTAL
TROUGH IS MOSTLY EAST OF I-95 THIS MORNING. BASED ON RAP 295-305K
LAYER ISENTROPIC ANALYSIS...THIS SHOULD GENERALLY BE THE CASE
THROUGH MIDDAY... PRIOR TO THE ARRIVAL OF A STRONGER SHORTWAVE AND
QG FORCING APPROACHING FROM THE WEST. THE HRRR SHOWS PRECIP
BEGINNING TO FILL IN OVER THE SOUTHERN AND WESTERN CWA AFTER
17Z...ALBEIT MOSTLY LIGHT QPF AMOUNTS OF LESS THAN 0.20" WITH LOWER
PW VALUES TO THE WEST AND LIMITED MOISTURE ABOVE -10C. CATEGORICAL
POPS IN THE CURRENT FORECAST LOOK GOOD...SO THE MAIN CHANGES TO THE
FORECAST WILL JUST BE TO ADJUST TEMPS BASED ON CURRENT TRENDS.
THINNER OVERCAST AND LACK OF PRECIP OVER THE WESTERN PIEDMONT HAS
ALLOWED FOR A LITTLE QUICKER CLIMB THIS MORNING...BUT STRATUS IS
THICKENING FROM THE SOUTHWEST AND ADDITIONAL WARM SHOULD BE VERY
SLOW TO OCCUR. HAVE LOWERED HIGHS A COUPLE DEGREES IN THE NORTHWEST
PIEDMONT...YIELDING 45-50 NORTHWEST TO SOUTHEAST. -SMITH
TONIGHT...A STRONG COLD FRONT ASSOCIATED WITH THE MID-UPPER LEVEL
S/W WILL SWEEP ACROSS CENTRAL NC DURING THE EVENING HOURS. THE
PASSAGE OF THE FRONT WILL BE NOTED BY THE SFC WINDS VEERING TOT HE
NW AND INCREASING TO AROUND 15KTS WITH FREQUENT GUSTS AROUND 25KTS.
THIS NW WIND WILL ADVECT MUCH COLDER AND DRIER AIR INTO CENTRAL NC.
THIS WILL LEAD TO A RAPID DISSIPATION OF THE PRECIPITATION FROM WEST-
TO-EAST IN THE EARLY EVENING WITH CLEARING SKIES OCCURRING SHORTLY
THEREAFTER. MODEL TEMP GUIDANCE HAS BEEN TRENDING COOLER WHICH SEEMS
REASONABLE CONSIDERING UPSTREAM CONDITIONS...SO HAVE FOLLOWED SUIT.
MIN TEMPS BY EARLY FRIDAY IN THE MID 20S NW TO THE LOWER 30S SE.
THESE COLD TEMPS ALONG WITH A BLUSTERY NW WIND WILL SEND WIND CHILL
VALUES DOWN INTO THE TEENS ACROSS THE PIEDMONT BY EARLY FRIDAY
MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 315 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT...ARCTIC-LIKE AIR MASS WILL SETTLE OVER
CENTRAL NC AS THE PARENT HIGH PRESSURE SYSTEM BUILDS INTO AND
SETTLES OVERHEAD BY FRIDAY NIGHT. SUSTAINED WINDS NEAR 20 MPH WITH
GUSTS 30-35 MPH WILL BE COMMON FRIDAY MORNING AFTERWHICH THE WINDS
WILL GRADUALLY SUBSIDE IN THE AFTERNOON. COULD SEE A FEW GUSTS
BETWEEN 40-45 MPH BUT BELIEVE THIS OCCURRENCE WILL BE LIMITED/FAIRLY
RANDOM. THUS...WILL NOT ISSUE A WIND ADVISORY WITH THIS PACKAGE BUT
LATER FORECAST ISSUANCES MAY NEED TO CONSIDER ONE. MAX TEMPS FRIDAY
WILL BE CLOSE TO 20 DEGREES BELOW NORMAL AS MAX TEMPS SHOULD RANGE
FROM THE LOW-MID 30S NORTH TO UPPER 30S TO NEAR 40 SOUTH.
UNDER CLEAR SKIES AND A SUBSIDING WIND REGIME...TEMPS WILL PLUMMET
AFTER SUNSET. AGAIN...MOS GUIDANCE HAS COME IN A LITTLE COLDER AND
PLAN TO ADJUST MIN TEMPS IN A SIMILAR FASHION. MIN TEMPS SHOULD
RANGE FROM THE MIDDLE TEENS IN THE OUTLYING AREAS...TO THE UPPER
TEENS AROUND 20 IN THE MORE URBANIZED LOCATIONS. -WSS
SATURDAY: ARCTIC HIGH PRESSURE OVER THE AREA TO START THE DAY ON
SATURDAY COUPLED WITH ONLY SHALLOW AFTERNOON MIXING WILL LEAD TO
WELL BELOW NORMAL TEMPS FOR SATURDAY... DESPITE THE HIGH MOVING
OFFSHORE ALLOWING FOR RETURN FLOW TO DEVELOP. GIVEN THIS AND BRIEF
MID LEVEL RIDGING ACROSS THE AREA EXPECT WE WILL SEE MOSTLY SUNNY
SKIES WITH HIGH TEMPS IN THE LOWER TO MID 40S. -BSD
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 320 AM THURSDAY...
SATURDAY NIGHT THROUGH MONDAY: A MID/UPPER LEVEL TROUGH WILL DEEPEN
SATURDAY INTO SUNDAY ACROSS THE CENTRAL U.S. AND BEGIN TO MOVE
EASTWARD ALLOWING ARCTIC AIR TO FLOOD INTO THE CENTRAL AND
EVENTUALLY EASTERN U.S. BEHIND AN ASSOCIATED ARCTIC COLD FRONT.
AHEAD OF THE FRONT ACROSS OUR AREA ON SATURDAY NIGHT INTO SUNDAY
EXPECT WE WILL SEE ISENTROPIC LIFT INCREASE AS 850 MB WINDS ACROSS
OUR WESTERN PIEDMONT INCREASE INTO THE 30 TO 40 KT RANGE SATURDAY
NIGHT INTO SUNDAY. WITH THE INCREASE MOISTURE AND SHALLOW ISENTROPIC
LIFT NWP GUIDANCE IS SHOWING SOME PRECIP DEVELOPING ACROSS OUR
WESTERN /NORTHWESTERN PIEDMONT VERY LATE SATURDAY INTO SUNDAY
MORNING. BOTH THE NAM AND GFS BUFR SOUNDING SHOW THE MOISTURE WILL
BE QUITE SHALLOW... WITH SATURATION NOT EVEN REACHING -10 DEGREES
CELSIUS. HOWEVER... FORECAST WETBULB TEMPS ARE EXPECTED TO BE BELOW
FREEZING ACROSS THE WESTERN AND NORTHWESTERN PIEDMONT WHEN PRECIP
MAY BEGIN TO MOVE INTO THE AREA EARLY SUNDAY MORNING... GIVEN THE
DRY AIR DEPOSITED BY THE ARCTIC SURFACE HIGH. THUS... EXPECT WE
COULD SEE A IN-SITU CAD AIRMASS DEVELOP... WITH POSSIBLY A FEW HOURS
OF FREEZING RAIN IN THE IN THE FAVORED NORTHWEST/WESTERN PIEDMONT.
THUS... HAVE ADDED RAIN AND/OR FREEZING RAIN WORDING TO THE FORECAST
WHEN TEMPS ARE EXPECTED TO BE 32 F OR LESS AND PRECIP IS IN THE
FORECAST FOR SUNDAY MORNING. GIVEN THE LATENT HEAT RELEASE FROM
PHASE CHANGE AND NO CONTINUED SOURCE OF DRY COLD AIR EXPECTED...
FREEZING RAIN SHOULD NOT LAST LONG AND ONLY BE A "NUISANCE" TYPE
EVENT... WITH ALL RAIN EXPECTED BY 15Z SUNDAY (GIVEN CURRENT TIMING
OF THE PRECIP AND ONLY A COUPLE TENTHS OF AN INCH AT BEST OF LIQUID
). WILL SHOW THE HIGHEST POPS IN THE NORTHWEST/WEST WHERE MOISTURE
AND LIFT APPEAR TO BE MAXIMIZED.
THIS FIRST AREA OF PRECIP WILL BEGIN TO LIFT OFF TO THE NORTHEAST OF
THE AREA ON SUNDAY AFTERNOON AS THE ARCTIC SURFACE FRONT APPROACHES
THE CENTRAL AND SOUTHERN APPALACHIAN MOUNTAINS. THIS CREATES A
DIFFICULT TEMP FORECAST... WITH THE POSSIBLE LINGERING CAD AIRMASS.
FOR NOW WILL LOWER HIGHS IN THE NORTHWEST AND RAISE HIGHS A BIT IN
THE SOUTHEAST. THIS YIELDS HIGH TEMP RANGING FROM THE MID 40S NW
(WHICH MAY BE TOO WARM) TO LOWER TO MID 60S SE.
THE ARCTIC FRONT IS EXPECTED TO MOVE THROUGH THE AREA EARLY MONDAY
MORNING... WITH THE BULK OF THE COLD AIR POSSIBLY DELAYED A BIT...
AS THE GFS AND ECMWF DIFFER IN HOW FAST THE LOW LEVEL THICKNESS
VALUES WILL PLUNGE AND THE COLD AIR ROARS IN HERE. FOR NOW WILL SHOW
TEMPS RANGING FROM THE LOWER 40S NW TO THE MID 50S E... WITH LOWS
MONDAY MORNING IN THE MID 30S TO THE LOWER 40S... WITH POSSIBLY A
FEW SHOWERS ACCOMPANYING THE FRONT AND MAYBE EVEN A FEW SNOW SHOWERS
ACROSS THE FAR NORTH/NORTHWEST (STILL TOO EARLY TO TELL IF THE COLD
AIR WILL BE ABLE TO CAUGHT UP WITH THE PRECIP).
MONDAY NIGHT THROUGH WEDNESDAY: ARCTIC HIGH PRESSURE WILL BUILD
ACROSS THE AREA DURING THIS TIME FRAME WITH SOME THE COLDEST AIR OF
THE SEASON... WITH HIGHS ON TUESDAY STRUGGLING TO REACH 30 DEGREES
FOR SOME LOCATIONS. THUS... EXPECT DRY BUT COLD CONDITIONS DURING
THIS TIME FRAME WITH WELL BELOW NORMAL TEMPS.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 640 AM THURSDAY...
A STRONG MID-UPPER LEVEL TROUGH APPROACHING FROM THE WEST
INTERACTING WITH AVAILABLE MOISTURE OVER THE CAROLINAS WILL CAUSE
AREAS OF RAIN TO GRADUALLY EXPAND NORTHWARD ACROSS CENTRAL NC THIS
MORNING. THE RAIN FALLING THROUGH THE RELATIVELY DRY SUB-CLOUD LAYER
WILL MOISTEN THE NEAR SURFACE AIR MASS LEADING TO THE DEVELOPMENT OF
WIDESPREAD IFR/LOW END MVFR CEILINGS LATER THIS MORNING (MAINLY
AFTER 15Z). THE AREAS OF RAIN LATE THIS MORNING INTO THE AFTERNOON
WILL LIMIT THE VISIBILITY BETWEEN 3-5SM WITH POCKETS OF 2SM
POSSIBLE.
BETWEEN 00Z-04Z FRIDAY...A STRONG COLD FRONT WILL SWEEP ACROSS THE
REGION. SFC WINDS WILL VEER TO THE NW AND INCREASE TO AROUND 15KTS
WITH FREQUENT GUSTS 25-30KTS. THIS WIND WILL ADVECT MUCH DRIER AND
COLDER AIR INTO CENTRAL NC...CAUSING THE LIGHT RAIN AND CLOUD COVER
TO QUICKLY DISSIPATE. EXPECT VFR CONDITIONS IN THE TRIAD REGION
SHORTLY AFTER 00Z...AND IN THE KRWI AND KFAY VICINITIES BY 03Z-04Z.
THE WINDY CONDITIONS WILL PERSIST OVERNIGHT INTO FRIDAY WITH
FREQUENT GUSTS AROUND 30KTS THROUGH 18Z FRIDAY. WINDS WILL BEGIN TO
SUBSIDE FRIDAY AFTERNOON AS A HIGH PRESSURE SYSTEM SETTLES OVERHEAD.
THIS WEATHER SYSTEM WILL MAINTAIN VFR CONDITIONS FRIDAY THROUGH
SATURDAY AFTERNOON.
THE NEXT THREAT FOR SUB-VFR CONDITIONS WILL OCCUR SATURDAY NIGHT
INTO SUNDAY AS ANOTHER MID-UPPER LEVEL TROUGH APPROACHES FROM THE
WEST. THIS WEATHER SYSTEM MAY CAUSE AREAS OF LIGHT PRECIPITATION TO
BREAK OUT LATE SATURDAY NIGHT INTO SUNDAY...LEADING TO MVFR
CEILINGS. A RETURN TO VFR CONDITIONS ANTICIPATED FOR MONDAY.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS/BSD
LONG TERM...BSD
AVIATION...WSS
AREA FORECAST DISCUSSION
NWS CHEYENNE WY
429 AM MST THU JAN 2 2014
.SHORT TERM...(TODAY THROUGH SATURDAY)
ISSUED AT 427 AM MST THU JAN 2 2014
THE REGION WILL BE IN BETWEEN SYSTEMS TODAY AS A TRANSITORY RIDGE
MOVES OVERHEAD. STEEP INVERSION COURTESY OF A FRESH SNOWPACK HAVE
LED TO POCKETS OF FOG EARLY THIS MORNING. IN FACT A FEW SITES AT
DOUGLAS AND CHEYENNE HAVE SEEN VISIBILITIES FALL TO ONE QUARTER
MILE FOR A BRIEF TIME. 11-3.9 FOG PRODUCT OFF THE SATELLITE SHOWS
THESE AREA DIMINISHING...SO EXPECT THEIR DISSIPATION BY DAYBREAK.
MEANWHILE NEAR ARLINGTON...WINDS HAVE FLARED UP TO NEAR HIGH WIND
CRITERIA. A DESCENDING STABLE LAYER CONTRIBUTED TO THE SURFACING
OF STRONGER WINDS ALOFT. MODELS PROG THIS STABLE LAYER TO REACH
THE SURFACE THIS MORNING . SO ALTHOUGH WINDS WILL BREEZY IN
ARLINGTON TODAY...EXPECT THEM TO HAVE PEAKED EARLY THIS MORNING
AND REMAIN BELOW CRITERIA THROUGH THE REST OF THE DAYLIGHT HOURS.
OTHERWISE FLOW WILL BEGIN TO FLATTEN TODAY AHEAD OF THE NEXT
MODERATELY AMPLIFIED SHORTWAVE APPROACHING THE PACNW. EXPECT SKIES
TO BE PARTLY/MOSTLY SUNNY EARLY GIVING WAY TO INCREASING CLOUDS
FROM WEST TO EAST TOWARDS EVENING. AS FOR TEMPERATURES FAVORED THE
LOW SIDE OF GUIDANCE GIVEN YESTERDAYS SNOWFALL. LLVL WAA WILL
STILL BE ABLE TO BOOST TEMPS INTO THE 30S AND LOW 40S AREA WIDE
TODAY.
BY TONIGHT...LLVL GRADIENT BEGINS TO TIGHTEN ONCE AGAIN AHEAD OF
THE PACNW SHORTWAVE. H85/H7 KCAG-KCPR GRADIENTS CLIMB BETWEEN 60
AND 70 METERS LATE THIS EVENING AND CONTINUE THROUGH THE DAY ON
FRIDAY. H7 PROGS SHOW 70 KNOTS THROUGH THE PERIOD AS WELL. ONE
INHIBITING FACTOR WILL BE THE LACK OF APPRECIABLE UPPER-LEVEL
SUBSIDENT JET SUPPORT. EVEN SO...AM CONFIDENT ENOUGH WITH THE
GRADIENT LEVELS AND PROGD H7 WINDS TO UPGRADE THE INHERITED HIGH
WIND WATCH TO A WARNING AT WIND PRONE LOCATIONS. ALTHOUGH WINDS
WILL BE STRONG ALOFT AT ADJACENT LOCATIONS AS WELL...AM NOT
CONFIDENT THAT THESE WILL REACH THE SFC IN THE ABSENCE OF
SUBSIDENCE.
ANOTHER MOSTLY DRY DAY FOR FRIDAY. THE EXCEPTION WILL BE OVER
OROGRAPHICALLY FAVORED AREAS OF THE SNOWY AND SIERRA MADRE RANGES
WHERE MOISTURE WILL BEGIN ADVECTING IN AHEAD OF THE NEXT
APPROACHING SHORTWAVE. OTHERWISE...WILL JUST SEE A THICKER CLOUD
CANOPY MOVING INTO THE AREA. WILL BE A CHINOOK DAY EAST OF THE
LARAMIE RANGE AS ADIABATIC WARMING AND DRYING PRODUCES HIGH
TEMPERATURES THAT WILL CLIMB INTO THE 50S.
CHANGES BEGIN FRIDAY NIGHT AND SATURDAY...A SOUTHWARD MOVING COLD
FRONT WILL SPREAD SNOW OUT ONTO THE PLAINS AND INCREASES RATES
OVER THE HIER TERRAIN. CONFIDENCE IS GROWING FOR THE POTENTIAL FOR
A LOW-END WARNING EVENT OVER THE SNOWY/SIERRA MADRE RANGES FOR THE
LATE FRIDAY THROUGH SATURDAY TIMEFRAME. MODELS HAVE UNDERDONE
PRECIPITATION IN RECENT EVENTS IN THIS AREA AND WITH THIS
SHORTWAVE STRONGER IN COMPARISON...CAN FIND LITTLE REASON TO ARGUE
WITH BEING GENEROUS WITH MODEL OUTPUT. SO...HAVE ISSUED A WINTER
STORM WATCH FOR THE SNOWY/SIERRA MADRE RANGES FOR THIS PERIOD.
ADJACENT LOWER ELEVATIONS WILL LIKELY SEE ANOTHER 1 TO 3 INCHES
DURING THIS PERIOD. THE EXCEPTION WILL BE OVER THE WESTERN
NEBRASKA PANHANDLE WHERE ACCUMULATIONS WILL REMAIN BELOW AN INCH.
H7 TEMPERATURES WILL FALL TO AROUND -15C FOR SATURDAY. SO HIGHS
WILL ONLY REACH GENERALLY INTO THE 20S.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 427 AM MST THU JAN 2 2014
OROGRAPHIC SNOW WILL CONTINUE ACROSS THE SIERRA MADRE AND SNOWY
RANGES ON SAT NIGHT IN MOIST NORTHWESTERLY FLOW ALOFT. THE UPPER
LEVEL JET ACROSS WESTERN WY WILL ALSO PROVIDE SOME LARGE SCALE
LIFT. THE MTN SNOW WILL LARGELY COME TO AN END BY SUN MORNING AS
THE JET SHIFTS EASTWARD. HIGHS ON SUN WILL BE COLD AS 700MB TEMPS
ARE AROUND -15C WITH WIDESPREAD CLOUD COVER ALSO. A STRONG
SHORTWAVE MOVING SOUTHWARD ACROSS THE DAKOTAS ON SUN WILL BRING A
FRONTAL SURGE AND REINFORCING SHOT OF VERY COLD AIR ACROSS THE
REGION BY THE AFTN AND NIGHT. THERE WILL BE A GOOD TEMP GRADIENT
OVER THE CWA BY SUN EVENING WITH 700MB TEMPS AT -15C IN RAWLINS AND
THE COLDEST AIR (700MB TEMPS OF -25C) OVER THE PANHANDLE. WIND
CHILL VALUES WILL APPROACH -30F OVER THE PANHANDLE ON SUN NIGHT.
STRONG SFC HIGH SLIDES EASTWARD OVER THE PLAINS ON MON WITH WINDS
BECOMING LIGHT SOUTHERLY BY THE AFTN. NOT EXPECTING A REAL
MODERATION IN TEMPS UNTIL TUES WHEN FLOW ALOFT BECOMES ZONAL AND A
LEE TROUGH DEVELOPS ACROSS THE PLAINS. THE MODELS HAVE A WEAK UPPER
LEVEL DISTURBANCE MOVING THROUGH UTAH/COLORADO BY LATE TUES AND WED
WHICH WILL INCREASE THE CHANCES OF OROGRAPHIC SNOW IN THE MTNS ONCE
AGAIN. NOT MUCH UPSLOPE OR LARGE SCALE SUPPORT FOR PRECIP SPREADING
OVER THE PLAINS. TEMPS WILL BE SEASONAL TO SLIGHTLY BELOW NORMAL
AFTER MON.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY EVENING)
ISSUED AT 942 PM MST WED JAN 1 2014
LATEST 11-3.9U SATELLITE IMAGERY SHOWING MOST OF SOUTHEAST WYOMING
FREE OF CLOUDS...BUT THERE IS SOME STRATUS BEING REPORTED UP BY
DOUGLAS. WITH A WESTERLY DOWNSLOPE WIND THOUGH...THINK CHANCES FOR
LOW CLOUDS/FOG WILL BE VERY LOCALIZED AND KEPT ALL AIRPORTS VFR
THROUGH THE NEXT 24 HOURS. LATEST HRRR MODEL RUN SUPPORTS THIS
DECISION AS WELL.
&&
.FIRE WEATHER...
ISSUED AT 427 AM MST THU JAN 2 2014
FIRE WEATHER CONCERNS WILL BE MINIMAL FOR THE FORESEEABLE FUTURE.
A DRIER AND WARMER PERIOD TAKING SHAPE FOR TODAY AND TOMORROW...AS
HIGH TEMPERATURES RETURN INTO THE 50S FOR SOME AREAS EAST OF THE
LARAMIE RANGE. STRONG WINDS WILL MAKE A RETURN TO PORTIONS OF
SOUTHEAST WYOMING TONIGHT AND FRIDAY. A HIGH WIND WARNING HAS BEEN
ISSUED FOR AREAS AROUND THE SOUTHERN LARAMIE RANGE AND NEAR
ARLINGTON. THE NEXT FRONT WILL BRING ANOTHER ROUND OF ACCUMULATING
SNOW LATE FRIDAY THROUGH SATURDAY. MOUNTAINS ARE EXPECTED TO
RECEIVE ANOTHER FOOT OF ACCUMULATION WITH THIS SYSTEM. MEANWHILE
LOWER ELEVATIONS WILL LIKELY ONLY SEE A COUPLE OF INCHES. A COLDER
WEEKEND AHEAD AS HIGHS ONLY REACH INTO THE TEENS AND 20S.
&&
.CYS WATCHES/WARNINGS/ADVISORIES...
WY...WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR WYZ112-114.
HIGH WIND WARNING FROM 6 PM THIS EVENING TO MIDNIGHT MST FRIDAY
NIGHT FOR WYZ106-110-116-117.
NE...NONE.
&&
$$
SHORT TERM...HAHN
LONG TERM...FINCH
AVIATION...CLAYCOMB
FIRE WEATHER...HAHN
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
951 AM MST THU JAN 2 2014
.UPDATE...
&&
.SHORT TERM...OVERALL...CURRENT FORECASTS LOOK ON TRACK. SHORT
WAVE RIDGE TO BUILD ACROSS REGION TODAY WITH WEAKENING NORTHWEST
FLOW ALOFT. WEAK MID LEVEL DISTURBANCE MOVING ACROSS NORTHERN
WYOMING SPREADING SOME MID LEVEL MOISTURE INTO NORTHWEST COLORADO
AT THIS TIME. LATEST SPATIAL CROSS SECTIONS SHOW THIS MOISTURE
MOVING INTO MOUNTAINS DURING THE AFTERNOON AND EVENING. WILL ADD A
BIT MORE CLOUD TO THE SKY GRIDS. NO OTHER CHANGES AT THIS TIME.
.AVIATION...CURRENT TAF TRENDS LOOK ON TRACK. WEAK SOUTHERLY
GRADIENT ACROSS AREA. WINDS A BIT MORE SOUTHWEST AT KDEN...BUT LESS
THAN 8 KTS. LATEST MODELS...INCLUDING THE RAP AND HRRR...STILL
SHOWING A COUNTERCLOCKWISE SHIFT IN THE WINDS ACROSS THE AREA
AIRPORTS THROUGH THE MORNING...WITH SOUTHEAST WINDS THROUGH 00Z.
THEN A RETURN TO SOUTHERLY DURING EVENING AS DRAINAGE DEVELOPS.
VFR TO CONTINUE THROUGH FRIDAY WITH INCREASING MID AND HIGH LEVEL
MOISTURE AFTER 15Z. WAVE CLOUD COULD DEVELOP ALONG FOOTHILLS WITH
CEILINGS AROUND 12000 FEET AT KBJC.
&&
.PREV DISCUSSION... /ISSUED 325 AM MST THU JAN 2 2014/
SHORT TERM...DRY AIR HAS MOVED OVER THE STATE AS NORTHWEST FLOW
ALOFT CONTINUES ALONG WITH SOME SHORT WAVE RIDGING EXPECTED. WINDS
ALOFT SHOULD BE DECREASING THROUGH TODAY AS THEY TRANSITION TO A
LITTLE MORE WESTERLY LATE IN THE AFTERNOON. AT THE SURFACE...
PRESSURE GRADIENTS WILL BE RELAXING THROUGH THE DAY AS A WEAK LEE
TROUGH OF LOW PRESSURE REMAINS OVER THE I-25 CORRIDOR. SKIES WILL
BE SUNNY THROUGH MOST OF THE DAY WITH LOW AND MID LEVEL
TEMPERATURES SUPPORTIVE OF AFTERNOON HIGHS IN THE MID 40S TO LOWER
50S. SOME HIGH LEVEL CLOUDINESS WILL MOVE OVERHEAD TONIGHT WHICH
WILL HELP TO KEEP LOW TEMPERATURES A BIT WARMER THAN WHAT WE SAW
THIS MORNING. ALL IN ALL A RATHER BENIGN DAY...WEATHERWISE.
LONG TERM...INCREASING WNW FLOW ALOFT WILL BE OVER THE AREA ON FRI
IN ADVANCE OF AN UPPER LEVEL TROUGH WHICH WILL AFFECT THE RGN
LATE FRI NIGHT INTO SAT. GUSTY WINDS WILL OCCUR IN THE MTNS AND
FOOTHILLS THRU THE DAY WITH SOME POTENTIAL FOR HIGH WINDS LATE FRI
AFTN INTO FRI EVENING AS MTN WAVE DEVELOPS AND AXIS OF STRONGER
UPPER LEVEL WINDS MOVES INTO THE AREA. MEANWHILE WITH WNW LOW LVL
WINDS DOWNSLOPE COMPONENT WILL ALLOW FOR HIGHS TO RISE INTO THE
50S OVER NERN CO WITH LOWER 60S IN THE DENVER AREA.
FOR LATE FRI NIGHT INTO SAT THE UPPER LEVEL TROUGH WILL MOVE
ACROSS THE AREA ALONG WITH A STG CDFNT. WITH INCREASING MOISTURE
IN THE MTNS AND FAVORABLE OROGRAPHICS SNOW SHOULD DEVELOP FRI
NIGHT AND CONTINUE THRU SAT WITH ADVISORY AMOUNTS LIKELY. AT
LOWER ELEVATIONS UPSLOPE FLOW WILL DEVELOP LATE FRI NIGHT INTO SAT
BEHIND THE STG CDFNT. AS THE UPPER LEVEL TROUGH MOVES ACROSS
ALONG WITH SOME MID LVL QG ASCENT SHOULD SEE A GOOD CHANCE OF SNOW
ESPECIALLY IN THE 12Z-18Z TIMEFRAME. WITH PLACEMENT OF UPPER LEVEL
JET MAY SEE SOME BANDED PCPN AS WELL. HIGHS ON SAT WILL OCCUR
EARLY IN THE DAY WITH READINGS STEADY IN THE 20S MUCH OF THE DAY
OVER THE PLAINS.
BY SAT NIGHT INTO SUN STG NWLY FLOW ALOFT WILL BE OVER THE AREA WITH
A DECREASE IN MOISTURE AND WEAK UPSLOPE FLOW. WILL LIKELY SEE SOME
ADDITIONAL LIGHT SNOW IN THE MTNS WITH GUSTY WINDS. OVER NERN CO IT
LOOKS MAINLY DRY ON SUN WITH HIGHS IN THE 25 TO 30 DEGREE RANGE. BY
LATE IN THE AFTN INTO SUN EVENING ANOTHER SHOT OF COLD AIR WILL MOVE
INTO NERN CO WITH SOME UPSLOPE FLOW WHICH COULD LEAD TO A CHC OF
LIGHT SNOW ESPECIALLY OVER THE PLAINS.
ON MON CROSS-SECTIONS SHOW A DRY AND COLD AIRMASS OVER THE RGN.
HIGHS ON MON OVER NERN CO LOOK TO BE IN THE UPPER TEENS TO MID 20S.
BY TUE THE FLOW ALOFT WILL BECOME MORE WLY WITH SOME MODERATION IN
TEMPS AS HIGHS RISE BACK INTO THE 30S ACROSS NERN CO. OUTSIDE OF A
SLIGHT CHC OF SNOW IN THE MTNS IT LOOKS DRY. BY WED A WEAK UPPER
LEVEL TROUGH MAY MOVE ACROSS THE AREA BRINGING A CHC OF SNOW TO THE
MTNS. OVER NERN CO WILL KEEP IT DRY WITH TEMPS NEAR SEASONAL
NORMALS.
AVIATION...NO AVIATION IMPACTS EXPECTED OVER THE NEXT 24 HOURS.
CEILINGS AND VISIBILITIES WILL BE UNRESTRICTED. SURFACE WINDS WILL
BE OUT OF THE SOUTH TO SOUTHEAST AT 10-14 KNOTS OR LESS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...D-L
LONG TERM....RPK
AVIATION...D-L
AREA FORECAST DISCUSSION
NWS ALBANY NY
1224 PM EST THU JAN 2 2014
.SYNOPSIS...
LOW PRESSURE MOVING ACROSS THE OHIO VALLEY TODAY WILL
REFORM OFF THE MID ATLANTIC COAST THIS EVENING...AND MOVE OFF THE
NORTHEAST COAST TONIGHT INTO TOMORROW. THIS WILL ALLOW FOR A
PROLONGED PERIOD OF SNOW ACROSS THE REGION THROUGH TOMORROW
MORNING. VERY COLD AIR WILL ACCOMPANY THIS SNOW...ESPECIALLY ACROSS
NORTHERN AND HIGH TERRAIN AREAS...WITH DANGEROUSLY COLD WIND CHILL
VALUES. DRY...BUT CONTINUED COLD WEATHER WILL BE IN PLACE ON
SATURDAY...BEFORE ANOTHER STORM THREATENS THE REGION FOR SUNDAY
INTO MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 845 AM EST...A BAND OF MODERATE SNOW HAS SET UP ACROSS THE
CAPITAL REGION...MOHAWK VALLEY REGION...EXTENDING INTO THE
SCHOHARIE VALLEY AND NE CATSKILLS...AND ALSO INTO SOUTHERN VT AND
THE NORTHERN BERKSHIRES. THIS BAND APPEARS TO BE IN ASSOCIATION
WITH STRONG 850-700 MB FRONTOGENETICAL FORCING...COMBINED WITH
ISENTROPIC LIFT. THE LATEST RUC13 SUGGESTS THAT THIS BAND OF MID
LEVEL FORCING...AND HEAVIER SNOWFALL...SHOULD SLOWLY LIFT
NORTHWARD LATER THIS MORNING INTO THE AFTERNOON HOURS...WITH THE
STEADIEST SNOWFALL SHIFTING INTO THE NORTH SIDE OF THE MOHAWK
VALLEY...THE LAKE GEORGE/SARATOGA REGION...AND SOUTHERN VT. IT IS
POSSIBLE THAT AREAS TO THE SOUTH...INCLUDING THE CAPITAL
REGION...EXPERIENCE A BREAK...OR AT LEAST SOME PERIODS OF LIGHTER
SNOWFALL...FOR MUCH OF THE AFTERNOON. WHERE THE BAND SETS UP...AN
ADDITIONAL 3-6 INCHES ARE EXPECTED THROUGH LATE AFTERNOON. FURTHER
SOUTH...GENERALLY 1-3 INCHES ARE EXPECTED...WITH EVEN LESS
POSSIBLE ACROSS PORTIONS OF THE MID HUDSON VALLEY AND NW CT REGION.
TEMPS HAVE FALLEN MUCH LOWER THAN ANY GUIDANCE SUGGESTED...WITH
CURRENT TEMPS GENERALLY RANGING FROM ZERO TO 5 ABOVE IN VALLEY
AREAS AND POINTS NORTH AND WEST...WITH SOME SINGLE DIGITS BELOW
ZERO ACROSS THE SOUTHERN ADIRONDACKS. FURTHER SOUTH AND
EAST...TEMPS RANGE FROM THE SINGLE DIGITS TO MID TEENS. WE EXPECT
TEMPS TO HOLD NEARLY STEADY THROUGH THIS AFTERNOON...ALTHOUGH
SHOULD FALL SEVERAL MORE DEGREES ACROSS PORTIONS OF THE MID HUDSON
VALLEY REGION AS THE COLD DENSE AIR CONTINUES TO SETTLE SOUTHWARD.
SO...EXPECT MOST VALLEY AREAS TO RANGE BETWEEN ZERO AND 10
ABOVE...WITH THE SOUTHERN ADIRONDACKS AND HIGHER ELEVATIONS ACROSS
WESTERN NEW ENGLAND POSSIBLY HOLDING AROUND ZERO.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SATURDAY/...
BY THIS EVENING...PRESSURE FALLS WILL BEGIN OCCURRING OFF THE MID
ATLANTIC COAST...AS A NEW AREA OF LOW PRESSURE FORMS OFF THE COAST
OF VIRGINA. THIS SURFACE LOW WILL THEN TRACK NORTHEASTWARD WELL
OFF THE COAST OF THE NORTHEASTERN US. ALTHOUGH THE SURFACE LOW
WON/T BE TOO CLOSE TO OUR REGION...IT WILL STILL BE ABLE TO THROW
SOME ADDITIONAL ATLANTIC MOISTURE BACK OUR WAY. WITH THE STRONG
UPPER TROUGH PASSING OVERHEAD...STEADY SNOWFALL LOOKS TO OCCUR
ACROSS THE ENTIRE REGION...WITH THE HEAVIEST AMOUNTS ACROSS HIGH
TERRAIN AREAS OF THE SOUTHERN AND EASTERN PARTS OF THE CWA.
WITH CONTINUED VERY HIGH SNOW TO LIQUID RATIOS...ADDITIONAL LIGHT TO
MODERATE SNOW ACCUMULATIONS ARE EXPECTED OVERNIGHT...ALLOWING FOR
STORM TOTAL ACCUMULATION OF 6 TO 12 INCHES OVER MUCH OF THE REGION
BY TOMORROW MORNING. SLIGHTLY LOWER AMOUNTS ARE EXPECTED OVER THE
WESTERN ADIRONDACKS WHERE LESS QPF IS EXPECTED...AND A FEW SPOTS
IN THE HIGH TERRAIN OF THE CATSKILLS...GREENS...AND BERKSHIRES MAY
SEE CLOSE 15 INCHES IN TOTAL. STEADY SNOW LOOKS TO TAPER OFF
AROUND SUNRISE TOMORROW.
WITH THE INCREASING PRESSURE GRADIENT DUE TO THE DEVELOPING LOW
PRESSURE...N-NE WINDS WILL PICK UP LATE TONIGHT INTO TOMORROW
MORNING. DUE TO THE VERY LIGHT AND FLUFFY SNOW...THIS WILL ALLOW
FOR BLOWING AND DRIFTING OF SNOWFALL. TEMPS WILL BE VERY COLD
TONIGHT WITH TEMPS RANGING FROM 25 BELOW ZERO OVER THE ADIRONDACKS
TO 10 ABOVE OVER THE MID HUDSON VALLEY AND NW CT. WITH THE GUSTY
WINDS...WIND CHILL VALUES WILL BE AS LOW AS -25 TO -40 OVER THE
ADIRONDACKS...AND -10 TO -25 ELSEWHERE. BECAUSE OF THIS...A WIND
CHILL WARNING HAS BEEN ISSUED FOR THE ADIRONDACKS...AND WIND CHILL
INFORMATION HAS BEEN POSTED IN OUR WINTER STORM WARNING /WSW/ FOR
THE REMAINDER OF THE REGION.
A FEW LINGERING SNOW SHOWERS MAY AFFECT EASTERN AREAS FOR TOMORROW
MORNING...OTHERWISE SOME SUNSHINE SHOULD RETURN BY AFTN. DESPITE
THE SUN RETURNING...IT WILL REMAIN VERY COLD WITH TEMPS IN THE
SINGLE DIGITS. SOME AREAS IN THE ADIRONDACKS AND WESTERN MOHAWK
VALLEY MAY NOT EVEN RISE ABOVE ZERO DURING THE DAY FRIDAY.
HIGH PRESSURE WILL MOVE OVER THE REGION FRIDAY NIGHT...ALLOWING
SKIES TO BE MAINLY CLEAR FOR MUCH OF THE REGION. WINDS WILL
LIGHTEN UP...AND WITH THE FRESH DEEP SNOW PACK...A VERY COLD NIGHT
IS IN STORE FOR FRIDAY NIGHT. THE ENTIRE CWA LOOKS TO DROP BELOW
ZERO...WITH TEMPS IN THE CAPITAL REGION DOWN AROUND -8 TO -15.
TEMPS AROUND GLENS FALLS AND IN THE ADIRONDACKS WILL BE -20 TO
-25. BEFORE WINDS LIGHTEN UP...ADDITIONAL WIND CHILL HEADLINES MAY
BE NEEDED FOR FRI NIGHT/EARLY SAT...AND THIS WILL BE MENTIONED IN
THE HWO. EVEN WITHOUT WIND...IT WILL BE BRUTALLY COLD ACROSS THE
WHOLE AREA...AND PRECAUTIONS WILL NEED TO BE TAKEN TO PREVENT
DAMAGE TO HOMES...BUSINESSES...AND LIVESTOCK.
HIGH PRESSURE WILL CONTINUE TO ALLOW FOR QUIET AND DRY WEATHER ON
SATURDAY. TEMPS WILL REMAIN BELOW NORMAL...BUT WILL MODERATE
SOMEWHAT FROM THE BRUTALLY COLD LEVELS OF FRI/FRI NIGHT...AS THE
HIGH PRESSURE AREA BEGINS TO SHIFT EASTWARD. MAX TEMPS ON SAT AFTN
LOOK TO REACH THE TEENS TO MID 20S ACROSS THE AREA.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
ANOTHER STORM SYSTEM FOR SUNDAY NIGHT INTO MONDAY WHICH SHOULD BRING
SNOW...SLEET...FREEZING RAIN AND RAIN TO THE AREA.
WE START OUT THE PERIOD A WITH A DEEP TROUGH DIGGING IN ACROSS THE
CENTRAL CONUS WHILE A STRONG UPPER LOW DROPS SOUTHWARD TOWARD THE
GREAT LAKES REGION. AT THE SURFACE...A LOW PRESSURE SYSTEM OVER THE
GREAT LAKES REGION WILL MOVE NORTHEASTWARD TOWARD HUDSON BAY CANADA
WITH ITS COLD FRONT TRAILING OFF TO THE SOUTHWEST ACROSS THE PLAINS
INTO THE DEEP SOUTH. THIS SYSTEM WILL NOT DIRECTLY IMPACT OUR
REGION. HOWEVER AS A POTENT SHORT WAVE ROTATING THROUGH THE BASE OF
THE DEEP TROUGH SURFACE LOW WILL SPIN UP ON THE COLD FRONTAL
BOUNDARY. IT IS THIS SYSTEM THAT WILL BRING A WINTRY MESS TO THE OUR
REGION TO CLOSE OUT THE WEEK AND START THE NEW WORK WEEK.
THERE IS MUCH UNCERTAINTY IN THE FORECAST AS MODEL DIFFERENCES
CONTINUE...HOWEVER THE ECMWF AND GFS HAVE TRENDED TOWARD EACH OTHER.
THE ECMWF IS STILL TRACKING THE LOW ACROSS THE OHIO VALLEY THEN
SAINT LAWRENCE VALLEY WHILE THE GFS TAKES THE LOW ACROSS NEW YORK
AND NEW ENGLAND SUNDAY NIGHT INTO MONDAY. THERE IS A WIDE SPREAD IN
THE GFSENSEMBLE TRACKS WITH THE OPERATIONAL GFS ON THE WEST SIDE OF
THE SOLUTIONS AND THE ECMWF MORE IN LINE WITH THE MOST WESTERN
MEMBERS. THE EXACT TRACK OF THE LOW WILL DETERMINE THE THERMAL
PROFILE AND THEREFORE P-TYPES AS WARMER AIR SURGES IN AHEAD OF THE
SYSTEM. HAVE FOLLOWED GUIDANCE FROM THE WEATHER PREDICTION CENTER
WHICH USED A BLENDED MODEL APPROACH.
BASED ON THIS TRACK AND TIMING TEMPERATURES SHOULD PEAK IN THE
MONDAY MORNING THEN FALL DURING THE AFTERNOON WITH THE PASSAGE OF
THE SYSTEM. DID UNDERCUT TEMPERATURES AS IT WILL BE HARD TO WARM UP
WITH WIDESPREAD DEEP FRESH SNOWPACK ACROSS AREA. AREAS MAINLY TO THE
EAST OF THE HUDSON RIVER VALLEY SHOULD WARM INTO THE LOWER/MID 40S.
A STRONG 850 MB JET OF 40 TO 60 KNOTS WILL BRING WARMER AIR IN ALOFT
AND THE STAGE WILL BE SET FOR SNOW...SLEET...FREEZING RAIN AND RAIN
ESPECIALLY LATE SUNDAY NIGHT INTO MONDAY MORNING. WILL MENTION STORM
IN OUR HAZARDOUS WEATHER OUTLOOK. THE PRECIPITATION SHOULD TAPER OFF
BY MONDAY EVENING WITH IT CHANGING BACK TO SNOW POSSIBLY BEFORE
ENDING AS COLD AIR IS USHERING IN. CONDITIONS WILL BECOME FAVORABLE
FOR LAKE EFFECT SNOWS IN THE WAKE OF THE SYSTEM.
COLDER AIR WILL SURGE IN BY 12Z/TUESDAY 850 MB TEMPERATURES ARE
EXPECTED TO DROP TO AROUND -25C...WITH SURFACE TEMPERATURES
BOTTOMING OUT INTO THE SINGLE DIGITS BY SUNRISE TUESDAY. DAYTIME
HIGHS TUESDAY AND WEDNESDAY WILL BE SIMILAR TO WHAT OUR NORMAL LOWS
SHOULD BE. WINDS WILL BE BRISK TUESDAY ONLY MAKING IT COLDER. COULD
HAVE ISSUES WITH WIND CHILLS AGAIN TUESDAY NIGHT INTO WEDNESDAY
MORNING.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
SNOW WILL CONTINUE THROUGH MUCH OF THE TAF PERIOD WNDING AT 18Z FRIDAY.
THE SNOW WILL COME DOWN HEAVIEST THIS EVENING AS AREA OF LOW
PRESSURE MOVES OFF THE MID ATLANTIC COAST AND STRENGTHENS TONIGHT.
IFR CONDITIONS WILL LOWER TO LIFR FOR THE EVENING WITH THE HEAVIER
SNOW. AN IMPROVEMENT TO MVFR IS EXPECTED TO OCCUR LATE IN THE
PERIOD AS THE SNOW LIGHTENS UP.
NORTH TO NORTHEAST WINDS AROUND 10 KNOTS WILL SHIFT MORE TO THE
NORTH AS THE DAY PROGRESSES AND INCREASE IN SPEED AS LOW MOVES OFF
THE MID ATLANTIC COAST AND STRENGTHENS. GUSTS TO AROUND 20 KNOTS ARE
EXPECTED.
OUTLOOK...
FRI NIGHT-SAT NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
SUN: MODERATE OPERATIONAL IMPACT. CHANCE OF RA...SN...SLEET.
SUN NIGHT-MON: HIGH OPERATIONAL IMPACT. LIKELY
RA...SN...FZRA...SLEET.
MON NIGHT-TUE: NO OPERATIONAL IMPACT. NO SIG WX.
&&
.HYDROLOGY...
NO WIDESPREAD HYDROLOGIC PROBLEMS ARE EXPECTED OVER THE NEXT FIVE
DAYS.
A STORM SYSTEM WILL BRING SNOW TO THE REGION TODAY THROUGH
TOMORROW MORNING. VERY COLD TEMPERATURES ARE EXPECTED LATE THIS
WEEK...WHICH WILL CONTINUE TO ALLOW RIVER AND LAKE ICE TO FORM AND
THICKEN.
ANOTHER STORM SYSTEM WILL BRING PRECIPITATION TO THE REGION LATE
SUNDAY INTO MONDAY. WITH WARMER AIR EXPECTED ALOFT...PRECIPITATION
WITH THIS SYSTEM WILL BEGIN AS SNOW OR A WINTRY MIX...AND PERHAPS CHANGING
TO RAIN IN SOME AREAS. PRECIPITATION AMOUNTS ARE STILL UNCERTAIN
WITH THIS SYSTEM.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING
OBSERVED AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE
VISIT THE ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON
OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...WINTER STORM WARNING UNTIL 10 AM EST FRIDAY FOR CTZ001-013.
NY...WINTER STORM WARNING UNTIL 10 AM EST FRIDAY FOR NYZ038>041-043-
047>054-058>061-063>066-082>084.
WINTER WEATHER ADVISORY UNTIL 10 AM EST FRIDAY FOR NYZ032-033-
042.
WIND CHILL WARNING FROM 7 PM THIS EVENING TO 11 AM EST FRIDAY
FOR NYZ032-033-042.
MA...WINTER STORM WARNING UNTIL 10 AM EST FRIDAY FOR MAZ001-025.
VT...WINTER STORM WARNING UNTIL 10 AM EST FRIDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...FRUGIS
NEAR TERM...FRUGIS/KL
SHORT TERM...FRUGIS
LONG TERM...IAA
AVIATION...IAA/11
HYDROLOGY...FRUGIS
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1200 PM CST THU JAN 2 2014
.MESOSCALE DISCUSSION...
1159 AM CST
THE LAKE EFFECT SNOW SHOWERS ACROSS NORTHEASTERN ILLINOIS CONTINUE
TO REMAIN CELLULAR AND IN MULTI BAND CLUSTERS. THESE SHOWERS ARE
PRODUCING PERIODS OF LOCALIZED HEAVY SNOW...WITH VIS DROPPING UNDER
A HALF MILE. HOWEVER...OUTSIDE OF THESE SHOWERS ONLY VERY LIGHT SNOW
IS OCCURRING ACROSS PORTIONS OF THE WARNED AREA. THIS APPEARS TO BE
SHORT LIVED.
ATTENTION FOR THIS AFTERNOONS ACTIVITY IS FOCUSED ON A WELL
DEVELOPED BAND OF HEAVY LAKE EFFECT SNOW...WHICH HAS DEVELOPED ALONG
A WELL DEFINED BOUNDARY LAYER CONVERGENCE ZONE ACROSS WESTERN LAKE
MICHIGAN...JUST OFF THE MKE SHORES. THIS BAND OF SNOW WILL SHIFT
SOUTHWARD ACROSS PORTIONS OF THE WARNED AREA OVER THE HOUR OR TWO.
IT APPEARS THAT THIS WILL SET UP ABOUT A 3 TO 5 HOUR PERIOD OF HEAVY
SNOW ACROSS EASTERN LAKE...AND COOK COUNTIES IN ILLINOIS THROUGH
THIS AFTERNOON...BEFORE THE WINDS BACK NORTHWESTERLY AND DRIVE THE
BAND INTO NORTHWESTERN INDIANA. DURING THIS TIME IT STILL APPEARS
THAT SNOW RATES OF 1 TO 2 INCHES PER HOUR COULD LEAD TO UP TO 4 TO 8
INCHES OF ADDITIONAL ACCUMULATIONS ACROSS ISOLATED PORTIONS OF THE
WARNED AREA. THIS PLUMB OF SNOW ALSO APPEARS THAT IT WILL PRODUCE
DECENT ACCUMULATIONS FAIRLY FAR INLAND ACROSS EASTERN SECTIONS OF
WILL...KANKEE AND POSSIBLY INTO PORTIONS OF IROQUO COUNTY AS WELL
DUE TO EHANCED BOUNDARY LAYER MOISTURE CONVERGENCE EXTENDING
SOUTHWARD WITHIN THE INVERTED SYNOPTIC SCALE TROUGH OF LOW
PRESSURE.
NORTHWESTERN INDIANA WILL SEE PERIODS OF LAKE EFFECT SNOW LATER THIS
AFTERNOON AND THIS EVENING. IT APPERS SNOWFALL AMOUNTS HERE WILL
ALSO EXCEED 6 INCHES ACROSS PORTIONS OF LAKE AND PORTER COUNTIES
THROUGH THIS EVENING BEFORE IT WINDS DOWN OVERNIGHT.
KJB
&&
.DISCUSSION...
854 AM CST
WE ARE MAKING SOME QUICK UPDATES TO THE HEADLINES THIS MORNING BASED
ON CURRENT TRENDS. WE WILL BE UPGRADING DUPAGE AND WILL COUNTIES IN
ILLINOIS TO LAKE EFFECT SNOW WARNINGS AND ADDING KANKAKEE COUNTY
INTO A LAKE EFFECT SNOW ADVISORY. WE ARE ALSO ADDING JASPER AND
NEWTON COUNTIES IN INDIANA TO THE ADVISORY AND UPGRADING PORTER TO A
WARNING.
AREA OBSERVATIONS AND RADAR IMAGERY INDICATES THAT THE MAIN
CONVERGENCE AXIS IS BEGINNING TO ORIENT ITSELF RIGHT ACROSS
NORTHEASTERN ILLINOIS. CURRENT INDICATIONS BASED ON OBSERVATIONS
INDICATES THAT THE CURRENT SHOWERY NATURE TO THE SNOW...WILL
ORGANIZE INTO A SINGLE BAND OF HEAVY LAKE EFFECT SNOW BY EARLY
AFTERNOON...AND THIS LOOKS TO SET UP RIGHT ACROSS PORTIONS OF LAKE
ILLINOIS...SOUTHWARD THROUGH COOK...FAR EASTERN DUPAGE...THROUGH
WILL AND KANKAKEE COUNTIES IN ILLINOIS THROUGH AT LEAST MID TO LATE
AFTERNOON. THIS BAND WILL THEN SHIFT EASTWARD ACROSS NORTHWESTERN
INDIANA THROUGH THE EVENING. SNOWFALL RATES HAVE ALREADY BEEN AROUND
OR JUST ABOVE AN INCH PER HOUR IN THE HEAVIER SNOW SHOWERS...AND
THESE RATES COULD EVEN INCREASE SOME AS THE BAND BECOME BETTER
ORGANIZED BY EARLY THIS AFTERNOON. SOME SNOW RATES COULD EXCEED 2"
PER HOUR. AS SUCH...SOME AREAS ACROSS THE WARNING AREA COULD GET IN
EXCESS OF 10 INCHES OF SNOW BEFORE THE SNOW TAPPERS LATE THIS
AFTERNOON.
THE NATURE OF THE SYNOPTIC SCALE INVERTED SURFACE TROUGH WILL ALLOW
THE LAKE EFFECT SNOW SHOWERS TO REACH WELL INLAND ACROSS PORTIONS OF
EAST CENTRAL ILLINOIS. THIS IS THE REASON FOR THE EXPANSION OF THE
ADVISORY INTO KANKAKEE IN ILLINOIS AND JASPER AND NEWTON COUNTIES IN
INDIANA.
IN ADDITION TO THE HEAVY SNOW...NORTHEAST WINDS OFF OF LAKE
MICHIGAN COULD GUST UP AROUND 30 KT...AND THIS WILL PRODUCE
BLOWING AND DRIFTING SNOW...ESPECIALLY NEAR THE LAKE. ALL AND
ALL...BLIZZARD LIKE CONDITIONS COULD DEVELOP UNDER THE HEAVIER
SNOW SHOWERS...WITH NEAR ZERO VIS POSSIBLE AT TIMES THIS
AFTERNOON.
KJB
//PREV DISCUSSION...
352 AM CST
SNOW AND COLD ONCE AGAIN ARE THE REPETITIVE HEADLINES TO THIS
FORECAST...AND IN FACT ARE THE HEADLINES THAT WE HAVE IN EFFECT.
THERE ARE LAKE EFFECT SNOW HEADLINES FOR TODAY ACROSS NORTHEAST IL
AND INTO NORTHWEST INDIANA TONIGHT...WITH SOME ADJUSTMENTS DONE FOR
TIMING AS WELL AS ADDING COUNTIES FOR AN ADVISORY. A WIND CHILL
ADVISORY HAS BEEN ISSUED FOR TONIGHT INTO FRIDAY MORNING FOR MUCH OF
NORTH CENTRAL AND PARTS OF NORTHEAST IL.
THE MASSIVE UPPER LEVEL TROUGH AND ITS EXPANSIVE COLD DEEP AIR
/500MB TEMPS NEARING -40C IN THE GREAT LAKES REGION/ REMAIN
ESTABLISHED OVER THE AREA. THIS IS EVEN SEEN ON THE HEMISPHERIC
WATER VAPOR IMAGERY THIS MORNING WITH A VERY EVIDENT DEEP ROSBY WAVE
CENTERED FROM HUDSON BAY TO GREENLAND AND EXTENDING ACROSS
CENTRAL/EASTERN NORTH AMERICA. PRONOUNCED JET AND UPPER SHORT WAVE
IS ROUNDING THE BASE OF THIS TROUGH ACROSS THE LOWER OHIO VALLEY
EARLY THIS MORNING. THIS WAS THE MAIN CAUSE OF OUR SNOW YESTERDAY
AND THAT HAS ALL BUT SHIFTED EAST OUT OF THE AREA EARLY THIS
MORNING...SO WILL BE ABLE TO LET THE WINTER WEATHER ADVISORY END AT
6 AM.
LOW PRESSURE OF 1013MB IS DEEPENING ACROSS TENNESSEE EARLY THIS
MORNING AND THAT WILL FURTHER DO SUCH INTO THE MID-ATLANTIC BY EARLY
EVE. WITH THE STRONG ARCTIC HIGH BUILDING INTO THE PLAINS...THIS
OVERALL PRESSURE EVOLUTION WILL FAVOR GRADUALLY VEERING WINDS ACROSS
THE LAKE. THIS SLOW VEERING WILL LIKELY HELP TO KEEP A MESOSCALE LOW
PRESSURE TROUGH/CONVERGENCE AXIS INTACT ACROSS THE FAR WESTERN PART
OF THE LAKE THROUGH THE MORNING. THIS AXIS EARLY THIS MORNING IS
ABOUT 35 MILES INLAND ACROSS NORTHEAST IL...BUT WILL SHIFT BACK OUT
TOWARD THE LAKE SHORE...LIKELY TOWARD MIDDAY AND BE THE FOCUS FOR
THE HEAVIEST LAKE EFFECT SNOW AND A LIKELY COUPLE/FEW HOUR PERIOD OF
VERY HEAVY RATES GIVEN THE VERY FAVORABLE PARAMETERS. THESE INCLUDE
STRONG LAKE-INDUCED INSTABILITY IN EXCESS OF 500 J/KG...THIS
INSTABILITY MAINLY COLLOCATED WITH SUPERSATURATION WITH RESPECT TO
ICE AND WITHIN THE DENDRITIC GROWTH AREA...AND CLOUD DEPTHS OF
9-10KFT. ALL THIS HAS BEEN CONSISTENTLY SHOWN BY THE NAM AND LOCAL
ARW.
PRIOR TO THIS AXIS...GENERAL ONSHORE FLOW INTO NORTHEAST IL HAS
ENOUGH INSTABILITY WITH IT TO BE DEVELOPING WIDESPREAD LAKE EFFECT
SNOW SHOWERS THIS MORNING...AND THESE ACTUALLY EXTEND AS FAR WEST IN
ILLINOIS AS ROCHELLE AND MENDOTA! A LONGER FETCH OF INSTABILITY IS
GRADUALLY WORKING INTO LAKE COUNTY IL FROM THE NORTH AND BASED ON
OBSERVATIONS OF LOWERING VISIBILITIES TO AT OR UNDER A
MILE...ACCUMULATIONS OF AROUND ONE HALF INCH PER HOUR WILL SLOWLY
SPREAD SOUTH. SO GIVEN THAT SNOW SHOWERS ARE ALREADY ONGOING WITH
PARAMETERS ONLY BETTERING...SEE NO REASON SNOW SHOWERS WILL NOT STOP
FOR NORTHEAST IL UNTIL THE FLOW TURNS OFFSHORE. THE HEAVIEST SNOW
AGAIN WILL BE CONFINED TO NEAR THAT CONVERGENT AXIS AND USING OUR
LOCAL 8KM ARW...THAT LOOKS TO LINE ITSELF INTO DOWNTOWN CHICAGO
DURING THE EARLY TO MID AFTERNOON...BEFORE SHIFTING EASTWARD INTO
NORTHWEST IN. THIS TIMING OF THE PROBABLE HEAVIEST RATES AND
DURATION IN WHICH THEY LAST...WILL LIKELY BE DEPENDENT ON IF A
MESOSCALE CIRCULATION CAN REMAIN INTACT OVER THE FAR SOUTHERN PART OF
THE LAKE TOO...BASICALLY SLOWLY THAT EASTWARD PROGRESSION. THE
LONGER THAT DOES SUCH...THE MORE PROBABLE THAT SOME CORRIDOR OF THE
LAKE EFFECT WARNING WILL REALIZE 6 OR MORE...POSSIBLY EVEN 8-10
INCHES OF SNOW. THE CONVERGENCE BEGINS TO WEAKEN LATE THIS EVENING
INTO NORTHWEST INDIANA AS IT CONTINUES TO PIVOT EAST...SO THAT
RESULTS IN SNOW ENDING FROM WEST TO EAST ACROSS ADJACENT COUNTIES TO
SOUTHERN LAKE MICHIGAN.
MODEL GUIDANCE REMAINS IN STRONG AGREEMENT WITH ANTICYCLONIC FLOW IN
THE LOW-LEVELS AND SUPPRESSION ALOFT DISSIPATING CLOUDS QUICKLY FROM
WEST TO EAST ACROSS NORTHERN IL LATE THIS AFTERNOON AND THIS EVE.
RADIATIONAL COOLING...HIGHLY ANOMALOUS COLD ATMOSPHERIC AIR...SLOWLY
DECREASING FLOW...AND A FRESH SNOWPACK ALL LOOK TO STILL COLLOCATE
FOR A VERY CHILLY NIGHT. HAVE MINS STILL IN THE -11 TO -18 ARENA
ACROSS ALL OF NORTH CENTRAL IL. HAVE HOISTED A WIND CHILL ADVISORY
AS WINDS WILL MAINTAIN ENOUGH FLOW TO MAKE IT DANGEROUS FOR ANY
PROLONGED EXPOSE SKIN.
FOR THIS WEEKEND WE CONTINUE TO WATCH A SYSTEM OF INTEREST. THE NEXT
IN A SERIES OF COLD FRONTS IS EXPECTED TO PASS SATURDAY AFTERNOON
WITH THE CHANCE FOR LIGHT SNOW. THE SLOWER EC HAS BEEN FOLLOWED
WHICH KEEPS THIS CHANCE OF SNOW AREAWIDE MAINLY DURING THE LATE
AFTERNOON AND NIGHT. AS THE NEXT UPPER TROUGH DEEPENS TO OUR
WEST...MUCH LIKE YESTERDAY...THAT WILL ENHANCE THE BAROCLINIC ZONE
OVER THE REGION POTENTIALLY PROVIDING FOR A FOCUS FOR SNOW LATER
SATURDAY NIGHT INTO SUNDAY. DO HAVE SOME LIKELY POPS IN THE
SOUTHEAST FORECAST AREA...BUT KNOWING THAT SHIFTS ARE INEVITABLE
WITH THIS HAVE NOT TRIED TO GET TOO FANCY. AT THIS TIME IT APPEARS
CHICAGO MAY BE GRAZED WITH THIS.
MTF
MONDAY THROUGH WEDNESDAY...
MAJOR ARCTIC BLAST ARRIVES EARLY MONDAY MORNING...WITH THE LATEST
GUIDANCE SHOWING NO SIGNS OF BACKING OFF ON THE DANGEROUSLY COLD
LOWS AND HIGH TEMPS FOR THE THE MON/TUE TIME FRAME.
ENSEMBLES FOR OVER A WEEK NOW HAVE INDICATED AN ARCTIC BLAST
ARRIVING FOR THE START OF NEXT WEEK...AND THIS CONTINUES TO BE THE
THEME. THE 500MB TROUGH AXIS ARRIVES OVER THE GREAT LAKES REGION
MON...AND WITH WEAK RIDGING OVER THE WESTERN ATLANTIC OCEAN
STRETCHING NORTH THROUGH THE CANADIAN MARITIME. THIS RIDGING WILL
LIKELY SLOW THE FORWARD PROGRESSION TO THE TROUGH AXIS...ALLOWING IT
TO LINGER LONGER OVER THE GREAT LAKES INTO TUE. THEN HEADING INTO
WED THE RIDGING OVER THE WESTERN ATLANTIC BEGINS TO PUSH
EAST...WHICH WILL ALLOW FOR A RELATIVELY MORE FLUID ATMOSPHERE AND
THE TROUGH AXIS WILL DRIFT EAST/NORTHEAST TOWARDS NEW ENGLAND.
AS PREVIOUSLY NOTED ABOUT THE COLD AIR...ENSEMBLES FOR NUMEROUS DAYS
HAVE BEEN PAINTING A HIGH CONFIDENCE THAT AT 850MB TEMPS BY EARLY
MON WILL BE ARND -24 TO -28 DEG C...WITH A POCKET OF -30 DEG C JUST
NORTH OF THE FORECAST AREA INTO CENTRAL/NORTHERN WISC. WITH THE SLOW
FORWARD PROPAGATION TO THE MID-LVL TROUGH...THIS WILL LIKELY KEEP
THE POTENT THERMAL TROUGH OVERHEAD INTO TUE. CLOSER TO THE SFC
RIDGING IS EXPECTED TO PUSH IN BEHIND THE ARCTIC FRONTAL BOUNDARY
AND PROVIDE RELATIVELY LITTLE IN THE WAY OF PRECIP TO THE FORECAST
AREA MON/TUE. UNFORTUNATELY WITH HOW COLD TEMPS WILL BE ALOFT AND A
THICK BLANKET OF SNOW...SFC TEMPS WILL EASILY HOLD WELL BELOW ZERO
FOR HIGHS BOTH MON/TUE. AT THIS TIME HIGH TEMPS MAY STRUGGLE ON BOTH
DAYS TO REACH -5 DEG F...WITH POSSIBLY A FEW LOCATIONS IN OUR
WESTERN CWFA STRUGGLING TO REACH -10 DEG C MON AFTN.
DEPENDING ON CLOUD COVER...OVERNIGHT LOWS COULD EASILY APPROACH
RECORD LOWS AT -15 TO -20 DEG F IN THIS TIMEFRAME. THE COMBINATION
OF DANGEROUSLY COLD SFC TEMPS...AND A GRADIENT PRODUCING BREEZY
CONDITIONS...WILL SET THE STAGE FOR WIND CHILL VALUES LIKELY TO
EXCEED -30 BELOW AND POSSIBLY APPROACH -40 DEG MON NGT. THE
GRADIENT SLACKENS FOR TUE NGT...HOWEVER WIND CHILL VALUES WILL ONCE
AGAIN APPROACH -20 TO -30 DEG F.
THEN TOWARDS THE MIDDLE OF NEXT WEEK THE TROUGH AXIS PIVOTS
EAST...WITH FLOW TURNING SOUTH/SOUTHWEST AND ADVECTING MUCH WARMER
AIR INTO THE REGION. ENSEMBLES HAVE CONTINUED TO INDICATE RELATIVELY
HIGH CONFIDENCE IN THE LONGER TERM PERIODS...WITH A MID-LVL TROUGH
DIGGING INTO THE SOUTHERN PLAINS AND POSSIBLY LEADING TO YET ANOTHER
ACTIVE PERIOD OF WEATHER FOR THE MIDDLE OF NEXT WEEK.
CONFIDENCE IN TEMPS MON/TUE...HIGH.
CONFIDENCE IN WIND CHILL VALUES MON/TUE...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIG/VSBY TRENDS THROUGH EARLY AFTERNOON WITH LAKE EFFECT SNOW.
* VARIABLE NORTH-NORTHWEST TO NORTH-NORTHEAST WINDS TRENDING
NORTH-NORTHWEST LATE THIS MORNING AT ORD...AND THIS AFTERNOON
AT MDW.
MDB/BMD
//DISCUSSION...UPDATED 14Z...
LAKE EFFECT SNOW CONTINUES TO EVOLVE WITH THE STEADIER WIDESPREAD
SNOW OF THE PAST FEW HOURS BEGINNING TO TRANSITION TO A MORE
CELLULAR AND NARROW BAND. 14Z RADAR IMAGERY SHOWS THE
BROADER/STEADIER SNOW BAND PIVOTING EASTWARD TOWARD THE GYY AREA
WITH THE NEWLY DEVELOPING NARROW/CELLULAR BAND SETTING UP FROM THE
WISCONSIN SHORELINE SOUTHWARD TO BETWEEN ORD/DPA DOWN TO JOT. AM
THINKING THAT THIS BAND MAY BECOME MORE FOCUSED IN THIS GENERAL
AREA THEN GRADUALLY PIVOT EASTWARD. THIS MORE FOCUSED BAND MAY BE
SURROUNDED BY A LARGER AREA OF LESS FOCUSED SNOW KEEPING SNOW
SHOWERS ACROSS A LARGER AREA. THE MAIN CHALLENGE WILL BE
DETERMINING HOW LONG IT WILL TAKE FOR THE MORE INTENSE SNOW TO
SHIFT EAST OF ORD/MDW...WITH DPA APPEARING TO BE JUST TO THE WEST
OF THE MAIN ACTIVITY. MAY NEED TO LOWER VSBY INTO THE 1/2SM RANGE
FOR A TIME DURING THE LATE MORNING AT ORD/MDW. GYY SHOULD START
TO SEE STEADIER SNOW WITH THE MAIN BAND ARRIVING MIDDAY/EARLY
AFTERNOON.
MDB
FROM 12Z...
A PRONOUNCED BAND OF LAKE EFFECT SNOW DEVELOPED DURING THE
PREDAWN HOURS AND WAS POSITIONED OVER THE CHICAGO METRO AREA
AROUND DAYBREAK. FLIGHT CONDITIONS WILL LIKELY REMAIN IFR THIS
MORNING DUE MAINLY TO VSBY RESTRICTIONS BUT PERIODS OF IFR CIGS
ARE ALSO POSSIBLE. DESPITE THE PERSISTENCE OF THIS BAND...HAVE
MOSTLY BEEN SEEING MVFR VSBYS WITH OCCASIONAL IFR...SO ELECTED TO
LEAN TOWARD THAT TREND IN LATEST UPDATES RATHER THAN MAINTAINING
THE LIFR FROM EARLIER FORECASTS. THIS DOES NOT MEAN LIFR IS
COMPLETELY OUT OF THE QUESTION...JUST THAT IT IS NOT EXPECTED TO
BE THE PREVAILING CONDITION FOR AN EXTENDED PERIOD OF TIME.
ACCUMULATING SNOW STILL IS EXPECTED TO WRAP UP BY MID AFTERNOON AT
THE ORD/MDW TERMINALS AS WINDS TURN NORTHWEST AND THE BAND SLIDES
SOUTH. FLURRIES ARE POSSIBLE INTO THE EVENING...THEN HIGH
PRESSURE MOVES INTO THE AREA TONIGHT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IN SOME IMPROVEMENT AT ORD IN NEXT COUPLE
HOURS...LOW CONFIDENCE ON VSBY TRENDS AT MDW.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS.
MDB/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW SHOWERS ARRIVE AFTERNOON...MVFR/IFR LIKELY.
SUNDAY...CHANCE SNOW SHOWERS AND MVFR/IFR.
MONDAY AND TUESDAY...BREEZY AND VFR...SOME MVFR POSSIBLE MONDAY.
WEDNESDAY...SNOW AND IFR POSSIBLE.
LENNING
&&
.MARINE...
326 AM CST
MAIN CONCERN IS STRONG LOW PRESSURE PASSING NORTH OF THE LAKES
FRIDAY NIGHT. LATEST MODELS CONTINUE THE TREND OF INCREASING WINDS
AND GUSTS FRIDAY NIGHT...SO ELECTED TO REPLACE THE GALE WATCH WITH
A STORM WATCH. REGARDLESS OF THE EXACT TRACK AND STRENGTH OF THE
LOW...FEEL FAIRLY CONFIDENT OF SEEING AT LEAST A PERIOD OF STORM
FORCE GUSTS...BUT NOT QUITE CONFIDENT ENOUGH YET TO GO WITH THE
WARNING. THESE STORM FORCE WINDS WOULD BE PRECEEDED BY GALES
FRIDAY AFTERNOON AND FOLLOWED BY GALES SATURDAY...BUT WILL CARRY
JUST A STORM WATCH FOR THE ENTIRE PERIOD TO AVOID COMPLICATING THE
HEADLINES.
IN THE NEARSHORE...GALES LIKELY WILL DEVELOP LATE FRIDAY INTO
SATURDAY DURING THE SAME PERIOD AS THE STORM FORCE WINDS IN THE
OPEN WATERS. SMALL CRAFT ADVISORIES CURRENTLY IN EFFECT DO LOOK
LIKE THEY CAN BE DROPPED FOR A SHORT TIME EARLY ON FRIDAY BEFORE
CONDITIONS RAPIDLY INCREASE AGAIN. TO DRAW ATTENTION TO THE SHORT
BREAK BEFORE THE NEW SYSTEM APPROACHING FRIDAY...AND TO AVOID
RUNNING THE HEADLINES TOGETHER...ELECTED TO HOLD OFF ON ISSUING A
GALE WATCH AT THIS TIME BUT DID MENTION IT IN THE FORECAST TEXT.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...LAKE EFFECT SNOW WARNING...ILZ006 UNTIL 3 PM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY
TO 10 AM FRIDAY.
LAKE EFFECT SNOW WARNING...ILZ013-ILZ014-ILZ022 UNTIL 6 PM
THURSDAY.
LAKE EFFECT SNOW ADVISORY...ILZ023 UNTIL 6 PM THURSDAY.
IN...LAKE EFFECT SNOW WARNING...INZ001-INZ002 UNTIL MIDNIGHT FRIDAY.
LAKE EFFECT SNOW ADVISORY...INZ010-INZ011 UNTIL MIDNIGHT FRIDAY.
LM...STORM WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON FRIDAY TO 4 PM
SATURDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 4 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 9 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
1126 AM CST Thu Jan 2 2014
.DISCUSSION...
ISSUED 956 AM CST Thu Jan 2 2014
Have allowed the winter weather advisory to expire across eastern
Illinois. Still seeing some visibilities from 1 to 2 miles at
times, but several reports of unknown precipitation on automated
observations are likely implying areas of blowing snow.
Main concern the remainder of the day will be with lake effect
snow. Radar returns over central Illinois have been increasing the
last few hours as moisture is advected in from southern Lake
Michigan. Latest RAP model shows the broader stream of lake effect
snow in northeast Illinois becoming more focused this afternoon
and pushing southward toward Champaign and Danville as the wind
over the lake become more north-northeast. Have maintained 30-40
percent PoP`s in the far northeast CWA into the afternoon, but
will have to watch this closely as the RAP suggests another 1-2
inches may not be out of the question in those areas with this
type of fetch. Over the remainder of the forecast area,
precipitation should start taping off to flurries and end from
west to east.
Geelhart
&&
.AVIATION...
ISSUED 1125 AM CST Thu Jan 2 2014
IFR conditions continuing at KBMI/KCMI as lake effect snow showers
spread southwest. The northeast flow causing these showers will
shift more toward the north-northeast, causing the snow axis to
swing more toward the Indiana border, but these may still affect
KCMI into mid afternoon, so will keep the lower visibilities in
the upcoming TAF issuance. Ceilings expected into improve to VFR
elsewhere over the next few hours, with the back edge of the lower
clouds currently from around KIJX-KGBG per visible satellite
imagery. Gusty northwest winds should begin to subside as high
pressure builds toward the mid-Mississippi Valley. Expect the
northwest winds to swing to the south as the high moves into
southern Illinois early Friday morning.
Geelhart
&&
.PREV DISCUSSION...
ISSUED 330 AM CST Thu Jan 2 2014
SHORT TERM...Today through Sunday night
Winter will keep a tight grip over central and southeast IL during
the next week with arctic air masses visiting the region into the
middle of next week along with a couple of weather systems
bringing more snow. Will expire the winter weather advisory along
and northwest of I-55 with forecast package at 4 am and continue
the winter wx advisory until 9 am for east central and southeast IL.
Snowfall total have generally averaged 2-3 inches across central
IL with lesser amounts in our far southeast counties where mixed
precipitation occurred since it begin late Wed evening, plus a dry
slot in that area too keeping precipitation lighter. Still have
band of light snow from I-55 southeast which HRRR diminishes from
NW to SE through 15Z/9 am. Up to another inch of snow possible
east of I-55 with 1-2 inches more snow east of I-57. Gusty NNW
winds today to cause some low drifting across east-west roads.
Elongated 1013 mb low pressure from southern Indiana into NW TN
early this morning to eject quickly to the mid Atlantic coast by
sunset and produce a winter storm over the Northeast States into
Friday. Scattered flurries over even a few light snow showers
possible over eastern IL this afternoon especially over east
central IL but any additional snow accumulations should be
confined NE of our area closer to the Great Lakes region. Highs
today range from 10-15F over the IL river valley, to the low to
mid 20s in southeast IL.
Will issue a wind chill advisory along and NW of a Rushville to
Bloomington/Normal line tonight and Friday morning for wind chills
getting down to 15-20 below zero. 1037 mb arctic high pressure
over the eastern Dakotas and NW MN to settle into the mid MS
valley Friday morning and bring very cold temps back into the
region. Clouds to decrease from west to east during tonight and
winds to also diminish allowing temps to drop into the single
digits below zero over central IL with Galesburg 10 below or even
colder. High pressure drifts east into the mid Atlantic states by
Friday evening with increasing south winds and fair amount of
sunshine but still cold highs in the upper teens and lower 20s
with fresh snow cover. Breezy south winds continue Sat with milder
temps in the low to mid 30s. Also have 20-40% chance of light snow
from I-55 NW during Sat afternoon with next wx system approaching.
Strong upper level trof to dig into the Midwest by Sunday with low
pressure ejecting NE from the southern plains into the eastern
great lakes region as it deepens. Snow to develop across central
IL Sat night and continue Sunday with be heaviest in southeast IL
where several inches of snow possible. Areas NW by the IL river
valley appear to be on NW fringe of this storm system with lighter
snow amounts. Snow to diminish during Sunday night as storm system
pulls away.
LONG TERM...Monday through Wednesday night
The coldest air of the season still slated to arrive early next
work with from Sunday night through Tue night with subzero lows
returning to central and even southeast IL by Monday night with
northern areas 10-15 below zero. Wind chills Monday night into Tue
morning to get to 20-35 below zero and coldest from I-74 north.
Flurries possible over eastern IL Monday with deep upper level
trof in place. Then next weather system appears to arrive by Wed
afternoon into Thu with next chance of snow with light snow
accumulations possible then. Models trending upward with temps
later next week as upper level heights rise, but skeptical about
too fast of warmup with snow pack in place.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY from 6 PM this evening to Noon CST Friday
FOR ILZ027>031-036>038-040-041.
&&
$$
AREA FORECAST DISCUSSION
NWS CHICAGO/ROMEOVILLE IL
1016 AM CST THU JAN 2 2014
.DISCUSSION...
854 AM CST
WE ARE MAKING SOME QUICK UPDATES TO THE HEADLINES THIS MORNING BASED
ON CURRENT TRENDS. WE WILL BE UPGRADING DUPAGE AND WILL COUNTIES IN
ILLINOIS TO LAKE EFFECT SNOW WARNINGS AND ADDING KANKAKEE COUNTY
INTO A LAKE EFFECT SNOW ADVISORY. WE ARE ALSO ADDING JASPER AND
NEWTON COUNTIES IN INDIANA TO THE ADVISORY AND UPGRADING PORTER TO A
WARNING.
AREA OBSERVATIONS AND RADAR IMAGERY INDICATES THAT THE MAIN
CONVERGENCE AXIS IS BEGINNING TO ORIENT ITSELF RIGHT ACROSS
NORTHEASTERN ILLINOIS. CURRENT INDICATIONS BASED ON OBSERVATIONS
INDICATES THAT THE CURRENT SHOWERY NATURE TO THE SNOW...WILL
ORGANIZE INTO A SINGLE BAND OF HEAVY LAKE EFFECT SNOW BY EARLY
AFTERNOON...AND THIS LOOKS TO SET UP RIGHT ACROSS PORTIONS OF LAKE
ILLINOIS...SOUTHWARD THROUGH COOK...FAR EASTERN DUPAGE...THROUGH
WILL AND KANKAKEE COUNTIES IN ILLINOIS THROUGH AT LEAST MID TO LATE
AFTERNOON. THIS BAND WILL THEN SHIFT EASTWARD ACROSS NORTHWESTERN
INDIANA THROUGH THE EVENING. SNOWFALL RATES HAVE ALREADY BEEN AROUND
OR JUST ABOVE AN INCH PER HOUR IN THE HEAVIER SNOW SHOWERS...AND
THESE RATES COULD EVEN INCREASE SOME AS THE BAND BECOME BETTER
ORGANIZED BY EARLY THIS AFTERNOON. SOME SNOW RATES COULD EXCEED 2"
PER HOUR. AS SUCH...SOME AREAS ACROSS THE WARNING AREA COULD GET IN
EXCESS OF 10 INCHES OF SNOW BEFORE THE SNOW TAPPERS LATE THIS
AFTERNOON.
THE NATURE OF THE SYNOPTIC SCALE INVERTED SURFACE TROUGH WILL ALLOW
THE LAKE EFFECT SNOW SHOWERS TO REACH WELL INLAND ACROSS PORTIONS OF
EAST CENTRAL ILLINOIS. THIS IS THE REASON FOR THE EXPANSION OF THE
ADVISORY INTO KANKAKEE IN ILLINOIS AND JASPER AND NEWTON COUNTIES IN
INDIANA.
IN ADDITION TO THE HEAVY SNOW...NORTHEAST WINDS OFF OF LAKE
MICHIGAN COULD GUST UP AROUND 30 KT...AND THIS WILL PRODUCE
BLOWING AND DRIFTING SNOW...ESPECIALLY NEAR THE LAKE. ALL AND
ALL...BLIZZARD LIKE CONDITIONS COULD DEVELOP UNDER THE HEAVIER
SNOW SHOWERS...WITH NEAR ZERO VIS POSSIBLE AT TIMES THIS
AFTERNOON.
KJB
//PREV DISCUSSION...
352 AM CST
SNOW AND COLD ONCE AGAIN ARE THE REPETITIVE HEADLINES TO THIS
FORECAST...AND IN FACT ARE THE HEADLINES THAT WE HAVE IN EFFECT.
THERE ARE LAKE EFFECT SNOW HEADLINES FOR TODAY ACROSS NORTHEAST IL
AND INTO NORTHWEST INDIANA TONIGHT...WITH SOME ADJUSTMENTS DONE FOR
TIMING AS WELL AS ADDING COUNTIES FOR AN ADVISORY. A WIND CHILL
ADVISORY HAS BEEN ISSUED FOR TONIGHT INTO FRIDAY MORNING FOR MUCH OF
NORTH CENTRAL AND PARTS OF NORTHEAST IL.
THE MASSIVE UPPER LEVEL TROUGH AND ITS EXPANSIVE COLD DEEP AIR
/500MB TEMPS NEARING -40C IN THE GREAT LAKES REGION/ REMAIN
ESTABLISHED OVER THE AREA. THIS IS EVEN SEEN ON THE HEMISPHERIC
WATER VAPOR IMAGERY THIS MORNING WITH A VERY EVIDENT DEEP ROSBY WAVE
CENTERED FROM HUDSON BAY TO GREENLAND AND EXTENDING ACROSS
CENTRAL/EASTERN NORTH AMERICA. PRONOUNCED JET AND UPPER SHORT WAVE
IS ROUNDING THE BASE OF THIS TROUGH ACROSS THE LOWER OHIO VALLEY
EARLY THIS MORNING. THIS WAS THE MAIN CAUSE OF OUR SNOW YESTERDAY
AND THAT HAS ALL BUT SHIFTED EAST OUT OF THE AREA EARLY THIS
MORNING...SO WILL BE ABLE TO LET THE WINTER WEATHER ADVISORY END AT
6 AM.
LOW PRESSURE OF 1013MB IS DEEPENING ACROSS TENNESSEE EARLY THIS
MORNING AND THAT WILL FURTHER DO SUCH INTO THE MID-ATLANTIC BY EARLY
EVE. WITH THE STRONG ARCTIC HIGH BUILDING INTO THE PLAINS...THIS
OVERALL PRESSURE EVOLUTION WILL FAVOR GRADUALLY VEERING WINDS ACROSS
THE LAKE. THIS SLOW VEERING WILL LIKELY HELP TO KEEP A MESOSCALE LOW
PRESSURE TROUGH/CONVERGENCE AXIS INTACT ACROSS THE FAR WESTERN PART
OF THE LAKE THROUGH THE MORNING. THIS AXIS EARLY THIS MORNING IS
ABOUT 35 MILES INLAND ACROSS NORTHEAST IL...BUT WILL SHIFT BACK OUT
TOWARD THE LAKE SHORE...LIKELY TOWARD MIDDAY AND BE THE FOCUS FOR
THE HEAVIEST LAKE EFFECT SNOW AND A LIKELY COUPLE/FEW HOUR PERIOD OF
VERY HEAVY RATES GIVEN THE VERY FAVORABLE PARAMETERS. THESE INCLUDE
STRONG LAKE-INDUCED INSTABILITY IN EXCESS OF 500 J/KG...THIS
INSTABILITY MAINLY COLLOCATED WITH SUPERSATURATION WITH RESPECT TO
ICE AND WITHIN THE DENDRITIC GROWTH AREA...AND CLOUD DEPTHS OF
9-10KFT. ALL THIS HAS BEEN CONSISTENTLY SHOWN BY THE NAM AND LOCAL
ARW.
PRIOR TO THIS AXIS...GENERAL ONSHORE FLOW INTO NORTHEAST IL HAS
ENOUGH INSTABILITY WITH IT TO BE DEVELOPING WIDESPREAD LAKE EFFECT
SNOW SHOWERS THIS MORNING...AND THESE ACTUALLY EXTEND AS FAR WEST IN
ILLINOIS AS ROCHELLE AND MENDOTA! A LONGER FETCH OF INSTABILITY IS
GRADUALLY WORKING INTO LAKE COUNTY IL FROM THE NORTH AND BASED ON
OBSERVATIONS OF LOWERING VISIBILITIES TO AT OR UNDER A
MILE...ACCUMULATIONS OF AROUND ONE HALF INCH PER HOUR WILL SLOWLY
SPREAD SOUTH. SO GIVEN THAT SNOW SHOWERS ARE ALREADY ONGOING WITH
PARAMETERS ONLY BETTERING...SEE NO REASON SNOW SHOWERS WILL NOT STOP
FOR NORTHEAST IL UNTIL THE FLOW TURNS OFFSHORE. THE HEAVIEST SNOW
AGAIN WILL BE CONFINED TO NEAR THAT CONVERGENT AXIS AND USING OUR
LOCAL 8KM ARW...THAT LOOKS TO LINE ITSELF INTO DOWNTOWN CHICAGO
DURING THE EARLY TO MID AFTERNOON...BEFORE SHIFTING EASTWARD INTO
NORTHWEST IN. THIS TIMING OF THE PROBABLE HEAVIEST RATES AND
DURATION IN WHICH THEY LAST...WILL LIKELY BE DEPENDENT ON IF A
MESOSCALE CIRCULATION CAN REMAIN INTACT OVER THE FAR SOUTHERN PART OF
THE LAKE TOO...BASICALLY SLOWLY THAT EASTWARD PROGRESSION. THE
LONGER THAT DOES SUCH...THE MORE PROBABLE THAT SOME CORRIDOR OF THE
LAKE EFFECT WARNING WILL REALIZE 6 OR MORE...POSSIBLY EVEN 8-10
INCHES OF SNOW. THE CONVERGENCE BEGINS TO WEAKEN LATE THIS EVENING
INTO NORTHWEST INDIANA AS IT CONTINUES TO PIVOT EAST...SO THAT
RESULTS IN SNOW ENDING FROM WEST TO EAST ACROSS ADJACENT COUNTIES TO
SOUTHERN LAKE MICHIGAN.
MODEL GUIDANCE REMAINS IN STRONG AGREEMENT WITH ANTICYCLONIC FLOW IN
THE LOW-LEVELS AND SUPPRESSION ALOFT DISSIPATING CLOUDS QUICKLY FROM
WEST TO EAST ACROSS NORTHERN IL LATE THIS AFTERNOON AND THIS EVE.
RADIATIONAL COOLING...HIGHLY ANOMALOUS COLD ATMOSPHERIC AIR...SLOWLY
DECREASING FLOW...AND A FRESH SNOWPACK ALL LOOK TO STILL COLLOCATE
FOR A VERY CHILLY NIGHT. HAVE MINS STILL IN THE -11 TO -18 ARENA
ACROSS ALL OF NORTH CENTRAL IL. HAVE HOISTED A WIND CHILL ADVISORY
AS WINDS WILL MAINTAIN ENOUGH FLOW TO MAKE IT DANGEROUS FOR ANY
PROLONGED EXPOSE SKIN.
FOR THIS WEEKEND WE CONTINUE TO WATCH A SYSTEM OF INTEREST. THE NEXT
IN A SERIES OF COLD FRONTS IS EXPECTED TO PASS SATURDAY AFTERNOON
WITH THE CHANCE FOR LIGHT SNOW. THE SLOWER EC HAS BEEN FOLLOWED
WHICH KEEPS THIS CHANCE OF SNOW AREAWIDE MAINLY DURING THE LATE
AFTERNOON AND NIGHT. AS THE NEXT UPPER TROUGH DEEPENS TO OUR
WEST...MUCH LIKE YESTERDAY...THAT WILL ENHANCE THE BAROCLINIC ZONE
OVER THE REGION POTENTIALLY PROVIDING FOR A FOCUS FOR SNOW LATER
SATURDAY NIGHT INTO SUNDAY. DO HAVE SOME LIKELY POPS IN THE
SOUTHEAST FORECAST AREA...BUT KNOWING THAT SHIFTS ARE INEVITABLE
WITH THIS HAVE NOT TRIED TO GET TOO FANCY. AT THIS TIME IT APPEARS
CHICAGO MAY BE GRAZED WITH THIS.
MTF
MONDAY THROUGH WEDNESDAY...
MAJOR ARCTIC BLAST ARRIVES EARLY MONDAY MORNING...WITH THE LATEST
GUIDANCE SHOWING NO SIGNS OF BACKING OFF ON THE DANGEROUSLY COLD
LOWS AND HIGH TEMPS FOR THE THE MON/TUE TIME FRAME.
ENSEMBLES FOR OVER A WEEK NOW HAVE INDICATED AN ARCTIC BLAST
ARRIVING FOR THE START OF NEXT WEEK...AND THIS CONTINUES TO BE THE
THEME. THE 500MB TROUGH AXIS ARRIVES OVER THE GREAT LAKES REGION
MON...AND WITH WEAK RIDGING OVER THE WESTERN ATLANTIC OCEAN
STRETCHING NORTH THROUGH THE CANADIAN MARITIME. THIS RIDGING WILL
LIKELY SLOW THE FORWARD PROGRESSION TO THE TROUGH AXIS...ALLOWING IT
TO LINGER LONGER OVER THE GREAT LAKES INTO TUE. THEN HEADING INTO
WED THE RIDGING OVER THE WESTERN ATLANTIC BEGINS TO PUSH
EAST...WHICH WILL ALLOW FOR A RELATIVELY MORE FLUID ATMOSPHERE AND
THE TROUGH AXIS WILL DRIFT EAST/NORTHEAST TOWARDS NEW ENGLAND.
AS PREVIOUSLY NOTED ABOUT THE COLD AIR...ENSEMBLES FOR NUMEROUS DAYS
HAVE BEEN PAINTING A HIGH CONFIDENCE THAT AT 850MB TEMPS BY EARLY
MON WILL BE ARND -24 TO -28 DEG C...WITH A POCKET OF -30 DEG C JUST
NORTH OF THE FORECAST AREA INTO CENTRAL/NORTHERN WISC. WITH THE SLOW
FORWARD PROPAGATION TO THE MID-LVL TROUGH...THIS WILL LIKELY KEEP
THE POTENT THERMAL TROUGH OVERHEAD INTO TUE. CLOSER TO THE SFC
RIDGING IS EXPECTED TO PUSH IN BEHIND THE ARCTIC FRONTAL BOUNDARY
AND PROVIDE RELATIVELY LITTLE IN THE WAY OF PRECIP TO THE FORECAST
AREA MON/TUE. UNFORTUNATELY WITH HOW COLD TEMPS WILL BE ALOFT AND A
THICK BLANKET OF SNOW...SFC TEMPS WILL EASILY HOLD WELL BELOW ZERO
FOR HIGHS BOTH MON/TUE. AT THIS TIME HIGH TEMPS MAY STRUGGLE ON BOTH
DAYS TO REACH -5 DEG F...WITH POSSIBLY A FEW LOCATIONS IN OUR
WESTERN CWFA STRUGGLING TO REACH -10 DEG C MON AFTN.
DEPENDING ON CLOUD COVER...OVERNIGHT LOWS COULD EASILY APPROACH
RECORD LOWS AT -15 TO -20 DEG F IN THIS TIMEFRAME. THE COMBINATION
OF DANGEROUSLY COLD SFC TEMPS...AND A GRADIENT PRODUCING BREEZY
CONDITIONS...WILL SET THE STAGE FOR WIND CHILL VALUES LIKELY TO
EXCEED -30 BELOW AND POSSIBLY APPROACH -40 DEG MON NGT. THE
GRADIENT SLACKENS FOR TUE NGT...HOWEVER WIND CHILL VALUES WILL ONCE
AGAIN APPROACH -20 TO -30 DEG F.
THEN TOWARDS THE MIDDLE OF NEXT WEEK THE TROUGH AXIS PIVOTS
EAST...WITH FLOW TURNING SOUTH/SOUTHWEST AND ADVECTING MUCH WARMER
AIR INTO THE REGION. ENSEMBLES HAVE CONTINUED TO INDICATE RELATIVELY
HIGH CONFIDENCE IN THE LONGER TERM PERIODS...WITH A MID-LVL TROUGH
DIGGING INTO THE SOUTHERN PLAINS AND POSSIBLY LEADING TO YET ANOTHER
ACTIVE PERIOD OF WEATHER FOR THE MIDDLE OF NEXT WEEK.
CONFIDENCE IN TEMPS MON/TUE...HIGH.
CONFIDENCE IN WIND CHILL VALUES MON/TUE...HIGH.
BEACHLER
&&
.AVIATION...
//ORD AND MDW CONCERNS...UPDATED 16Z...
* CIG/VSBY TRENDS THROUGH EARLY AFTERNOON WITH LAKE EFFECT SNOW.
* VARIABLE NORTH-NORTHWEST TO NORTH-NORTHEAST WINDS TRENDING
NORTH-NORTHWEST LATE THIS MORNING AT ORD...AND THIS AFTERNOON
AT MDW.
MDB/BMD
//DISCUSSION...UPDATED 14Z...
LAKE EFFECT SNOW CONTINUES TO EVOLVE WITH THE STEADIER WIDESPREAD
SNOW OF THE PAST FEW HOURS BEGINNING TO TRANSITION TO A MORE
CELLULAR AND NARROW BAND. 14Z RADAR IMAGERY SHOWS THE
BROADER/STEADIER SNOW BAND PIVOTING EASTWARD TOWARD THE GYY AREA
WITH THE NEWLY DEVELOPING NARROW/CELLULAR BAND SETTING UP FROM THE
WISCONSIN SHORELINE SOUTHWARD TO BETWEEN ORD/DPA DOWN TO JOT. AM
THINKING THAT THIS BAND MAY BECOME MORE FOCUSED IN THIS GENERAL
AREA THEN GRADUALLY PIVOT EASTWARD. THIS MORE FOCUSED BAND MAY BE
SURROUNDED BY A LARGER AREA OF LESS FOCUSED SNOW KEEPING SNOW
SHOWERS ACROSS A LARGER AREA. THE MAIN CHALLENGE WILL BE
DETERMINING HOW LONG IT WILL TAKE FOR THE MORE INTENSE SNOW TO
SHIFT EAST OF ORD/MDW...WITH DPA APPEARING TO BE JUST TO THE WEST
OF THE MAIN ACTIVITY. MAY NEED TO LOWER VSBY INTO THE 1/2SM RANGE
FOR A TIME DURING THE LATE MORNING AT ORD/MDW. GYY SHOULD START
TO SEE STEADIER SNOW WITH THE MAIN BAND ARRIVING MIDDAY/EARLY
AFTERNOON.
MDB
FROM 12Z...
A PRONOUNCED BAND OF LAKE EFFECT SNOW DEVELOPED DURING THE
PREDAWN HOURS AND WAS POSITIONED OVER THE CHICAGO METRO AREA
AROUND DAYBREAK. FLIGHT CONDITIONS WILL LIKELY REMAIN IFR THIS
MORNING DUE MAINLY TO VSBY RESTRICTIONS BUT PERIODS OF IFR CIGS
ARE ALSO POSSIBLE. DESPITE THE PERSISTENCE OF THIS BAND...HAVE
MOSTLY BEEN SEEING MVFR VSBYS WITH OCCASIONAL IFR...SO ELECTED TO
LEAN TOWARD THAT TREND IN LATEST UPDATES RATHER THAN MAINTAINING
THE LIFR FROM EARLIER FORECASTS. THIS DOES NOT MEAN LIFR IS
COMPLETELY OUT OF THE QUESTION...JUST THAT IT IS NOT EXPECTED TO
BE THE PREVAILING CONDITION FOR AN EXTENDED PERIOD OF TIME.
ACCUMULATING SNOW STILL IS EXPECTED TO WRAP UP BY MID AFTERNOON AT
THE ORD/MDW TERMINALS AS WINDS TURN NORTHWEST AND THE BAND SLIDES
SOUTH. FLURRIES ARE POSSIBLE INTO THE EVENING...THEN HIGH
PRESSURE MOVES INTO THE AREA TONIGHT.
LENNING
//ORD AND MDW CONFIDENCE...UPDATED 16Z...
* MEDIUM CONFIDENCE IN SOME IMPROVEMENT AT ORD IN NEXT COUPLE
HOURS...LOW CONFIDENCE ON VSBY TRENDS AT MDW.
* MEDIUM-HIGH CONFIDENCE IN WIND TRENDS.
MDB/BMD
//OUTLOOK FOR ORD/MDW FOR 00Z SATURDAY-12Z THURSDAY...UPDATED 12Z...
FRIDAY NIGHT...VFR.
SATURDAY...SNOW SHOWERS ARRIVE AFTERNOON...MVFR/IFR LIKELY.
SUNDAY...CHANCE SNOW SHOWERS AND MVFR/IFR.
MONDAY AND TUESDAY...BREEZY AND VFR...SOME MVFR POSSIBLE MONDAY.
WEDNESDAY...SNOW AND IFR POSSIBLE.
LENNING
&&
.MARINE...
326 AM CST
MAIN CONCERN IS STRONG LOW PRESSURE PASSING NORTH OF THE LAKES
FRIDAY NIGHT. LATEST MODELS CONTINUE THE TREND OF INCREASING WINDS
AND GUSTS FRIDAY NIGHT...SO ELECTED TO REPLACE THE GALE WATCH WITH
A STORM WATCH. REGARDLESS OF THE EXACT TRACK AND STRENGTH OF THE
LOW...FEEL FAIRLY CONFIDENT OF SEEING AT LEAST A PERIOD OF STORM
FORCE GUSTS...BUT NOT QUITE CONFIDENT ENOUGH YET TO GO WITH THE
WARNING. THESE STORM FORCE WINDS WOULD BE PRECEEDED BY GALES
FRIDAY AFTERNOON AND FOLLOWED BY GALES SATURDAY...BUT WILL CARRY
JUST A STORM WATCH FOR THE ENTIRE PERIOD TO AVOID COMPLICATING THE
HEADLINES.
IN THE NEARSHORE...GALES LIKELY WILL DEVELOP LATE FRIDAY INTO
SATURDAY DURING THE SAME PERIOD AS THE STORM FORCE WINDS IN THE
OPEN WATERS. SMALL CRAFT ADVISORIES CURRENTLY IN EFFECT DO LOOK
LIKE THEY CAN BE DROPPED FOR A SHORT TIME EARLY ON FRIDAY BEFORE
CONDITIONS RAPIDLY INCREASE AGAIN. TO DRAW ATTENTION TO THE SHORT
BREAK BEFORE THE NEW SYSTEM APPROACHING FRIDAY...AND TO AVOID
RUNNING THE HEADLINES TOGETHER...ELECTED TO HOLD OFF ON ISSUING A
GALE WATCH AT THIS TIME BUT DID MENTION IT IN THE FORECAST TEXT.
LENNING
&&
.LOT WATCHES/WARNINGS/ADVISORIES...
IL...LAKE EFFECT SNOW WARNING...ILZ006 UNTIL 3 PM THURSDAY.
WIND CHILL ADVISORY...ILZ003-ILZ004-ILZ005-ILZ006-ILZ008-ILZ010-
ILZ011-ILZ012-ILZ019-ILZ020-ILZ021-ILZ032...9 PM THURSDAY
TO 10 AM FRIDAY.
LAKE EFFECT SNOW WARNING...ILZ013-ILZ014-ILZ022 UNTIL 6 PM
THURSDAY.
LAKE EFFECT SNOW ADVISORY...ILZ023 UNTIL 6 PM THURSDAY.
IN...LAKE EFFECT SNOW WARNING...INZ001-INZ002 UNTIL MIDNIGHT FRIDAY.
LAKE EFFECT SNOW ADVISORY...INZ010-INZ011 UNTIL MIDNIGHT FRIDAY.
LM...STORM WATCH...LMZ080-LMZ261-LMZ362-LMZ364-LMZ366-LMZ563-LMZ565-
LMZ567-LMZ669-LMZ671-LMZ673-LMZ675-LMZ777-LMZ779-LMZ868-
LMZ870-LMZ872-LMZ874-LMZ876-LMZ878...NOON FRIDAY TO 4 PM
SATURDAY.
SMALL CRAFT ADVISORY...NEARSHORE WINTHROP HARBOR TO GARY IN UNTIL 4 AM
FRIDAY.
SMALL CRAFT ADVISORY...NEARSHORE GARY TO MICHIGAN CITY IN UNTIL 9 AM FRIDAY.
&&
$$
VISIT US AT HTTP://WEATHER.GOV/CHICAGO (ALL LOWERCASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.CHICAGO.GOV
WWW.TWITTER.COM/NWSCHICAGO
WWW.YOUTUBE.COM/NWSCHICAGO
Area Forecast Discussion
National Weather Service Lincoln IL
958 AM CST Thu Jan 2 2014
.DISCUSSION...
ISSUED 956 AM CST Thu Jan 2 2014
Have allowed the winter weather advisory to expire across eastern
Illinois. Still seeing some visibilities from 1 to 2 miles at
times, but several reports of unknown precipitation on automated
observations are likely implying areas of blowing snow.
Main concern the remainder of the day will be with lake effect
snow. Radar returns over central Illinois have been increasing the
last few hours as moisture is advected in from southern Lake
Michigan. Latest RAP model shows the broader stream of lake effect
snow in northeast Illinois becoming more focused this afternoon
and pushing southward toward Champaign and Danville as the wind
over the lake become more north-northeast. Have maintained 30-40
percent PoP`s in the far northeast CWA into the afternoon, but
will have to watch this closely as the RAP suggests another 1-2
inches may not be out of the question in those areas with this
type of fetch. Over the remainder of the forecast area,
precipitation should start taping off to flurries and end from
west to east.
Geelhart
&&
.AVIATION...
ISSUED 521 AM CST Thu Jan 2 2014
Snow in process of ending at KDEC and will likely end at KCMI by
14z as low pressure over southern Indiana continues moving away
from central Illinois. MVFR and occasional IFR Cigs will likely
persist even though associated mid-level trough moves across
Illinois around midday. Northeast flow will likely produce lake
effect snows over northeast Illinois and the moisture along with
occasional reductions in visibilities will likely reach as far
south as KBMI, KDEC, and of course KCMI. Will keep MVFR Cigs at
KPIA and KSPI without the snow shower threat.
Clearing is finally expected in the 02-05z window from west to
east as the surface high reaches central Illinois. Gusty north
winds today should diminish this evening.
Barker
&&
.PREV DISCUSSION...
ISSUED 330 AM CST Thu Jan 2 2014
SHORT TERM...Today through Sunday night
Winter will keep a tight grip over central and southeast IL during
the next week with arctic air masses visiting the region into the
middle of next week along with a couple of weather systems
bringing more snow. Will expire the winter weather advisory along
and northwest of I-55 with forecast package at 4 am and continue
the winter wx advisory until 9 am for east central and southeast IL.
Snowfall total have generally averaged 2-3 inches across central
IL with lesser amounts in our far southeast counties where mixed
precipitation occurred since it begin late Wed evening, plus a dry
slot in that area too keeping precipitation lighter. Still have
band of light snow from I-55 southeast which HRRR diminishes from
NW to SE through 15Z/9 am. Up to another inch of snow possible
east of I-55 with 1-2 inches more snow east of I-57. Gusty NNW
winds today to cause some low drifting across east-west roads.
Elongated 1013 mb low pressure from southern Indiana into NW TN
early this morning to eject quickly to the mid Atlantic coast by
sunset and produce a winter storm over the Northeast States into
Friday. Scattered flurries over even a few light snow showers
possible over eastern IL this afternoon especially over east
central IL but any additional snow accumulations should be
confined NE of our area closer to the Great Lakes region. Highs
today range from 10-15F over the IL river valley, to the low to
mid 20s in southeast IL.
Will issue a wind chill advisory along and NW of a Rushville to
Bloomington/Normal line tonight and Friday morning for wind chills
getting down to 15-20 below zero. 1037 mb arctic high pressure
over the eastern Dakotas and NW MN to settle into the mid MS
valley Friday morning and bring very cold temps back into the
region. Clouds to decrease from west to east during tonight and
winds to also diminish allowing temps to drop into the single
digits below zero over central IL with Galesburg 10 below or even
colder. High pressure drifts east into the mid Atlantic states by
Friday evening with increasing south winds and fair amount of
sunshine but still cold highs in the upper teens and lower 20s
with fresh snow cover. Breezy south winds continue Sat with milder
temps in the low to mid 30s. Also have 20-40% chance of light snow
from I-55 NW during Sat afternoon with next wx system approaching.
Strong upper level trof to dig into the Midwest by Sunday with low
pressure ejecting NE from the southern plains into the eastern
great lakes region as it deepens. Snow to develop across central
IL Sat night and continue Sunday with be heaviest in southeast IL
where several inches of snow possible. Areas NW by the IL river
valley appear to be on NW fringe of this storm system with lighter
snow amounts. Snow to diminish during Sunday night as storm system
pulls away.
LONG TERM...Monday through Wednesday night
The coldest air of the season still slated to arrive early next
work with from Sunday night through Tue night with subzero lows
returning to central and even southeast IL by Monday night with
northern areas 10-15 below zero. Wind chills Monday night into Tue
morning to get to 20-35 below zero and coldest from I-74 north.
Flurries possible over eastern IL Monday with deep upper level
trof in place. Then next weather system appears to arrive by Wed
afternoon into Thu with next chance of snow with light snow
accumulations possible then. Models trending upward with temps
later next week as upper level heights rise, but skeptical about
too fast of warmup with snow pack in place.
07
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
WIND CHILL ADVISORY from 6 PM this evening to Noon CST Friday
FOR ILZ027>031-036>038-040-041.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
310 PM EST THU JAN 2 2014
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 310 PM EST THU JAN 2 2014
19Z SFC ANALYSIS SHOWS THE NOW DEEPER LOW JUST EAST OF KENTUCKY WITH
THE TIGHT ISOBARS CROSSING INTO EAST KENTUCKY. THIS IS RESULTING IN
STIFF NORTHWEST WINDS WITH GUSTS TO 30 MPH BRINGING IN THE MUCH
COLDER AIR. RAIN HAS CHANGED TO SNOW ACROSS WESTERN PARTS OF THE
AREA AND NOW HERE AT JKL. ANOTHER HOUR OR SO IT WILL BE SNOW
EVERYWHERE...IN PLACES THAT STILL ARE PRECIPITATING. THERE IS
CURRENTLY A DISTINCT BACK EDGE TO THIS POST FRONTAL SNOW AREA.
HOWEVER...ANOTHER DECENT BATCH OF SNOW IS DROPPING THROUGH SOUTHERN
INDIANA ON RADAR AND THIS SHOULD MOVE OVER OUR CWA THIS EVENING.
TEMPERATURES CURRENTLY VARY FROM THE LOW 40S NEAR MIDDLESBORO TO
AROUND FREEZING OVER OUR WESTERN COUNTIES. DEWPOINTS ARE PEGGED TO
THE TEMPERATURE IN MOST SPOTS WITH THE GUSTY NORTHWEST WINDS NOW
REPORTED AT MOST OBS SITES IN THE AREA.
THE MODELS ARE IN GOOD AGREEMENT ALOFT WITH THE SHARP AND DEEP TROUGH
CURRENTLY SWINGING THROUGH THE AREA. HEIGHTS WILL THEN QUICKLY CLIMB
LATE TONIGHT INTO FRIDAY IN THE WAKE OF THE DEPARTING WAVE. FAST...
MOSTLY ZONAL...FLOW FOLLOWS INTO SATURDAY MORNING WITH ONLY VERY
MINOR BITS OF ENERGY FLOATING BY IN THE AIR STREAM AT MID LEVELS.
WITH NO GREAT DISTINCTION IN THE MODELS HAVE FAVORED A BLEND WITH A
LEAN TOWARD THE HRRR AND NAM12 FOR NEAR TERM SPECIFICS.
SENSIBLE WEATHER WILL FEATURE A BAND OF SNOW MOVING THROUGH EAST
KENTUCKY ASSOCIATED WITH THE RETURN OF AN ARCTIC AIR MASS. SOME
PLACES...PARTICULARLY IN THE SOUTHWEST...WILL SEE A LULL IN THE SNOW
FOR SEVERAL HOURS INTO THE EVENING WITH A POSSIBLE RESURGENCE AROUND
00Z AS THAT SNOW OVER INDIANA MOVES INTO OUR CWA. EVEN IN THOSE
PLACES...HAZARDOUS CONDITIONS WILL EXIST AS WET ROADS A THREAT TO
ICE OVER SINCE THE ARCTIC AIR QUICKLY DROPS TEMPERATURES INTO THE 20S
FROM WEST TO EAST LATE THIS AFTERNOON AND EARLY EVENING.
ACCORDINGLY...WILL MAINTAIN THE CURRENT ADVISORY STRUCTURE AND FOCUS
ON THE REFREEZE FOR WESTERN MOST PLACES THAT WILL NOT GET MUCH OF THE
UPSLOPE. OTHERWISE...UPSLOPE SNOW SHOWERS/ SQUALLS...COLD TEMPS...
AND LOSS OF SOLAR INSOLATION SHOULD HELP THE EASTERN PORTION OF THE
ADVISORIES PICK UP SNOW TOTALS THROUGH THE EVENING. THE SNOWS WILL
TAPER OFF FROM WEST TO EAST LATER TONIGHT...ENDING LAST IN LOCATIONS
NEAR THE VIRGINIA AND WEST VIRGINIA BORDERS TOWARD DAWN. BY THAT TIME
READINGS WILL BE DOWN IN THE TEENS FOR MOST LOCATIONS WITH SOME
SINGLE DIGITS POSSIBLE IN THE FAR NORTHWESTERN PARTS OF THE CWA.
WINDS RUNNING IN THE 5 TO 10 MPH RANGE INTO EARLY FRIDAY MORNING
WILL YIELD WIND CHILLS IN MANY SPOTS DOWN NEAR ZERO. THE QUICK EXIT
OF THE WEATHER MAKER WILL RETURN SUNNY SKIES TO THE AREA ON FRIDAY...
BUT CAA AND THE ARCTIC AIR IN PLACE WILL KEEP TEMPERATURES FROM
GETTING ANY HIGHER THAN THE LOW TO MID 20S. THIS WILL SET THE STAGE
FOR ANOTHER BITTERLY COLD NIGHT WITH READINGS FALLING INTO THE TEENS
AGAIN ALONG WITH NOTICEABLE RIDGE AND VALLEY DIFFERENCES.
AGAIN LEANED ON THE SOLID CONSSHORT OR BC VERSION FOR HOURLY TEMPS...
DEWS...AND WINDS THROUGH 12Z FRIDAY WITH CONSALL AFTER THAT. AS FOR
POPS...WENT HIGHER THAN GUIDANCE TONIGHT DUE TO IT NOT PICKING UP ON
UPSLOPE SNOWS VERY WELL...DRY AFTER THAT.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 250 PM EST THU JAN 2 2014
PRETTY GOOD AGREEMENT AMONGST THE MODELS FOR THE EXTENDED PERIOD.
THE ECMWF MODEL IS A BIT MORE ROBUST WITH ITS QPF THAN THE GFS FOR
THE SUNDAY NIGHT THROUGH MONDAY NIGHT WEATHER SYSTEM...AND THE
WEATHER SYSTEM FOR THE END OF THE WEEK. HOWEVER...THE OVERALL LARGE
SCALE WEATHER PATTERN...BOTH ALOFT AND AT THE SURFACE...IS SIMILAR
IN BOTH MODELS. THAT BEING SAID...WENT MORE TOWARD THE ECMWF
SOLUTION THIS TIME AROUND. TOOK DOWN SNOWFALL TOTALS
SLIGHTLY...HOWEVER...AS THE MODELS HAVE MORE WESTERLY...AS OPPOSED
TO NORTHWESTERLY...FLOW FORECAST...WHICH WOULD BE MUCH LESS
FAVORABLE FOR UPSLOPE SNOW SHOWERS. THE DYNAMICS WITH THE SYSTEM TO
BEGIN THE WEEK ARE STILL EXPECTED TO BE QUITE STRONG...WITH A WELL
DEVELOPED AREA OF LOW PRESSURE MOVING OUT OF THE MID MISSISSIPPI
VALLEY THROUGH THE OHIO VALLEY AND THEN INTO THE EASTERN GREAT LAKES
REGION. A 50 TO 60KT LOW LEVEL JET WOULD BRING AMPLE GULF MOISTURE
INTO THE REGION ALOFT TO AID IN ICE CRYSTAL AND THEREFORE SNOWFLAKE
FORMATION SUNDAY NIGHT AND MONDAY. SNOWFALL TOTALS...DUE TO THE GOOD
DYNAMICS...COULD STILL RANGE BETWEEN 2 AND 3 INCHES FOR MOST OF THE
AREA DURING THE INITIAL EVENT. BITTERLY COLD ARCTIC AIR WILL SPILL
INTO THE AREA TO BEING THE WEEK. THE COLDEST NIGHT OF THE UPCOMING
WORK WEEK LOOKS TO BE MONDAY NIGHT...WHEN LOWS COULD CONCEIVABLE
DROP TO ZERO OR BELOW ZERO FOR THE ENTIRE AREA. WITH THE MODEL
SOUNDINGS DEPICTING 850 HPA TEMPERATURES IN THE MINUS 24 TO MINUS 30
RANGE...SUBZERO LOWS MONDAY NIGHT WOULD NOT BE ALL THAT SURPRISING.
THE COLD AIR MASS WILL MODIFY ONLY SLIGHT TUESDAY WITH HIGHS PEAKING
IN THE TEENS FOR MOST OF THE AREA...WITH HIGHS BARELY TOPPING OUT
AROUND 10 DEGREES NORTH OF I-64. LOWS IN THE SINGLE DIGITS ARE
LIKELY TUESDAY NIGHT...AS WINDS GO NEARLY CALM BENEATH PARTLY CLOUDY
SKIES. HIGHS AND LOWS WEDNESDAY THROUGH THURSDAY WILL BE WELL BELOW
AS WELL...AS THE COLD AIR MASS MAINTAINS ITS GRIP ON THE AREA. A
SECOND WEATHER SYSTEM IS THEN PROGGED TO MOVE ACROSS THE TENNESSEE
AND OHIO VALLEY REGIONS TO END THE WEEK...WITH MORE POTENTIAL FOR
ACCUMULATING SNOW WEDNESDAY NIGHT INTO EARLY THURSDAY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1245 PM EST THU JAN 2 2014
CEILINGS WILL BE RATHER LOW...DOWN TO LIFR AT TIMES...THROUGH THE
REST OF THE AFTERNOON AND EVENING AS RAIN AND DRIZZLE TRANSITIONS TO
SNOW. WINDS WILL INCREASE TO BETWEEN 10 TO 15 KTS WITH GUSTS OVER 20
KTS AS THEY SWITCH TO THE NORTHWEST BY MID AFTERNOON. EXPECT GRADUAL
IMPROVEMENTS TO CIGS AND VIS FOR THE LATTER PART OF THE TAF PERIOD
WHILE THE WINDS ALSO SETTLE TO BETWEEN 5 AND 10 KTS FROM THE
NORTHWEST FOR THE FIRST PART OF FRIDAY.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR KYZ052-
058>060-104-106-108.
WINTER WEATHER ADVISORY UNTIL 10 PM EST THIS EVENING FOR KYZ044-
050-051-068-069-079-080-083-084.
WINTER WEATHER ADVISORY UNTIL 8 AM EST FRIDAY FOR KYZ088-118-120.
WINTER WEATHER ADVISORY UNTIL 6 AM EST FRIDAY FOR KYZ085>087-107-
109>117-119.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PADUCAH KY
204 PM CST Thu Jan 2 2014
.SHORT TERM /TODAY THROUGH SATURDAY/...
ISSUED AT 350 AM CST THU JAN 2 2014
In the near term...the minor snow event appears to be on track to
occur in the next several hours. The rain/snow line was located
roughly from Mt. Carmel to Marion IL...southwest to Poplar Bluff
MO at 09z. This transition line will move southeast across all but
the khop area by around 13z. Radar indicates a swath of steady
snow /20 to 25 dbz echoes/ from just se of kstl to kuno as of 09z.
Based on HRRR simulated reflectivity and RAP 1000/500 mb mean
rh fields...this area of steadier snow is likely to lift
east/northeast across the existing winter weather advisory area
this morning. Forecast snowfall amounts appear on track...though
they have been tweaked slightly downward in some areas. Any two
inch amounts would be rather isolated.
Forecast model soundings indicate a very well mixed boundary layer
this afternoon as the arctic air mass settles in. This may
translate to considerable cold air stratocu and flurries. Gusty
winds are also anticipated...with bufkit momentum transfer
algorithm suggesting gusts around 30 mph. Guidance is in
agreement that temperatures will remain steady in the 20s this
afternoon.
The remainder of the forecast is dry...so the main issue is temps.
A 1035 mb surface high will be centered almost directly over the
kstl area at 12z Friday. With clear skies and light
winds...conditions would suggest low temps near zero over snow
cover. The main concern is where the significant snow cover will
exist. Will tweak lows further downward over anticipated snow
cover along and northwest of a line from kmdh to the Wabash
Valley. Elsewhere...model guidance appears reasonable.
Southerly return flow will develop on the back side of the high
Friday. Due to the cold start to the day...highs will still not
reach freezing despite abundant sunshine. Increasing southwest
low level flow Friday night and Saturday will eventually bring
temps close to climo ahead of the next arctic front.
.LONG TERM...(Saturday Night through Thursday)
ISSUED AT 150 PM CST THU JAN 2 2014
The long term event begins Saturday night. This is packing the
potential to be a major hazardous weather event for our region. It
is a near certainty that brutal arctic cold not seen since the mid
90s will hit the region for Monday and Tuesday. We see single
digit to teens for Highs, and near zero or even negative digits
for Lows. With a little wind, chills bottom out at -10 to -20 late
Monday night and Tuesday. Looking at Local Storm Reports for the
last such event, we highlighted the impacts from said event in a
headlined Special Weather Statement, and hit hard in social media,
to get the word out early on this coming impact of brutal arctic cold.
The precip with the event may also be signficant, if but for parts
of the area. Factors in favor of a signficant impact event include
the new model solutions for a closed surface low passing near or
just south/east of the FA. Some of the modeling includes a 925 mb
and/or 850 mb low passing along a similar track, and this would
enhance the potential for heavy snow bands. Excellent thermo-
dynamics exist for a potential heavy snow or embedded snow bands
within a 6 to 9 hour time frame from late Saturday night into
Sunday. It is still a tad too far out in time to pinpoint, but
preliminary estimated totals via allblend qpf amounts suggest
generally a range from trace/inch or less along our southern
border, to about an inch or two across the heart of the FA, to
potentially warning criteria across our north. This will be
monitored closely over the next 24 hours in case a headline
becomes warranted.
After the brutal early week cold, we do remain below freezing
through the mid week, then have a chance at moderating back to
above the freezing mark by the end of the week. However, snow
cover could impact this negatively, and another system is shaping
up for the days 7-8 time frame that may negate it as well.
&&
.AVIATION...
ISSUED AT 150 PM CST THU JAN 2 2014
MVFR cigs continue in bands, most dense east (KEVV/KOWB) to
scattering west (KCGI). This trend will continue thru the pm
hours, then we should start to see some improvement in overall sky
condition through the overnight hours. Anticipate a return to VFR
by the planning period as we transition to a more tranquil pattern
for the ensuing 24-48 hours.
&&
.PAH WATCHES/WARNINGS/ADVISORIES...
IL...NONE.
MO...NONE.
IN...NONE.
KY...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
421 PM EST THU JAN 2 2014
LATEST UPDATE...
MARINE
.SYNOPSIS...
ISSUED AT 236 PM EST THU JAN 2 2014
THE BIG WEATHER STORY IS THE COLD OUTBREAK EXPECTED EARLY NEXT WEEK.
HIGHS IN THE SINGLE DIGITS AND LOWS IN THE 0 TO 10 BELOW RANGE ARE
EXPECTED. WIND CHILLS COULD DROP AS LOW AS 25 BELOW ON MONDAY AND
TUESDAY. WIND GUSTS ARE FORECAST TO BE AROUND 20 TO 30 MPH.
ANOTHER VERY COLD NIGHT IS IN STORE TONIGHT WITH LOWS IN THE 0 TO
5 BELOW RANGE. SOME LIGHT SNOW NEAR THE LAKESHORE IS POSSIBLE
FRIDAY. WIDESPREAD HEAVIER SNOW WILL MOVE IN SUNDAY AND SUNDAY
NIGHT. SIGNIFICANT ACCUMULATIONS APPEAR LIKELY AT THIS
TIME...ESPECIALLY SOUTH AND EAST OF GRAND RAPIDS.
TEMPERATURES WILL MODERATE CONSIDERABLY ON SATURDAY BEFORE THE
ARCTIC AIR PLUNGES BACK IN. HIGHS ON SATURDAY WILL BE NEAR 30
DEGREES.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 303 PM EST THU JAN 2 2014
MAIN CHALLENGE IN THE VERY SHORT TERM IS ASSESSING SNOW POTENTIAL
NEAR THE LAKESHORE...PARTICULARLY AROUND THE SABLE POINTS OF MASON
AND OCEANA COUNTIES. A DOMINANT LAKE SNOW BAND NEAR THE WESTERN LAKE
MICHIGAN SHORELINE THIS MORNING IS SLOWLY DRIFTING EAST. THE LAST
SEVERAL HRRR MODEL RUNS...AS WELL AS THE NAM...APPEAR TO BE PLACING
OR MOVING THIS FEATURE TOO FAR EAST TOWARDS THE POINTS.
IT IS LOOKING MORE LIKELY THAT WE WILL CLEAR OUT OVER INLAND ZONES
TONIGHT...ALLOWING FOR VERY COLD INLAND TEMPERATURES FRIDAY MORNING
AND A LAND BREEZE THAT HAS A GOOD CHANCE OF KEEPING THE SNOW BAND
OFFSHORE. DISCUSSED THIS WITH THE GAYLORD OFFICE AND WE BOTH CONCUR
THAT THIS IS THE MOST LIKELY SCENARIO AT THIS POINT. HAVE THEREFORE
TRIMMED POPS AND ACCUMULATIONS EXCEPT FOR THE IMMEDIATE COAST.
STILL LOOKING FAVORABLE FOR LIGHT LAKE ENHANCED SNOW FRIDAY AHEAD OF
THE NEXT CLIPPER. DID NOT CHANGE THE INHERITED FORECAST
SIGNIFICANTLY. FROM FRIDAY NIGHT THROUGH SATURDAY POPS INCREASE FROM
NORTHWEST TO SOUTHEAST AHEAD OF THE CLIPPER AND ASSOCIATED COLD
FRONT WHICH SHOULD BE ENTERING THE FORECAST AREA BY SATURDAY EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM EST THU JAN 2 2014
THE MEDIUM RANGE MODELS CONTINUE IN GOOD AGREEMENT ON THE LARGE
SCALE FLOW WITH MINOR DIFFERENCES IN THE SMALLER SCALE FEATURES.
CONFIDENCE IS HIGH DUE TO CONTINUITY IN TIME AND SPACE. WIND CHILL
VALUES AND SNOWFALL ARE THE CHALLENGES WITH THIS FORECAST PACKAGE.
TEMPERATURES WILL FALL TO 0-5 DEGREES SUNDAY NIGHT AND ON MONDAY THE
HIGHS WILL BE AROUND 5 DEGREES ABOVE ZERO. THE LOWS MONDAY NIGHT
WILL BE BELOW ZERO. VALUES THIS LOW HAVE NOT BEEN SEEN IN THIS AREA
SINCE FEB 2007. THE TEMPERATURES WILL BEGIN TO RECOVER WEDNESDAY.
ALONG WITH THE COLD AIR... STRONG GUSTY WINDS OUT OF THE WEST AND
NORTHWEST WILL PRODUCE LOW WIND CHILL VALUES. THE COLDEST WIND
CHILLS... BETWEEN 20 AND 30 DEGREES BELOW ZERO ARE POSSIBLE MONDAY
EVENING INTO TUESDAY MORNING. A WIND CHILL ADVISORY AND MAYBE A WIND
CHILL WARNING WILL BE NEEDED MONDAY AFTERNOON THROUGH TUESDAY
AFTERNOON.
THIS ALSO SEEMS TO BE A SNOWY PERIOD OF TIME. AN UPPER LOW WILL DROP
SOUTH FROM NEAR THE POLE AND MOVE EAST ACROSS SOTHERN CANADA THROUGH
THE LONG TERM. THIS AND SHORTWAVES MOVING THROUGH THE FLOW AROUND
THE LOW WILL BRING THE COLD AIR... CYCLONIC FLOW AND SNOW. A FEW
SHORTWAVES SHOULD PASS CLOSE ENOUGH TO THE AREA TO RESULT IN SNOW
SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE UPPER LOW WILL HELP TO BUMP
UP THE LAKE EFFECT SNOW MONDAY INTO WEDNESDAY AS THE SYSTEM PULLS
AWAY. WITH THE COLD TEMPERATURES... THE LAKE EFFECT SNOW IS EXPECTED
TO BE IN THE FORM OF SMALL ICE CRYSTALS. THEREFORE THE SNOW WILL NOT
STACK UP... BUT THE STRONG WINDS WILL BLOW THIS SNOW AROUND. THIS
WILL RESULT IN GREATLY REDUCED VISIBILITIES. THIS WILL ESPECIALLY BE
TRUE NEAR LAKE MICHIGAN.
A MORE ZONAL FLOW PATTERN WILL ENSUE WEDNESDAY... AS A LOW PRESSURE
SYSTEM BEGINS MOVING BY TO THE SOUTH OF THE REGION. THIS HAS THE
POTENTIAL FOR ADDITIONAL SNOWFALL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1254 PM EST THU JAN 2 2014
THE BAND OF SNOW IS FINALLY DIMINISHING AND PULLING OUT OF THE
FORECAST AREA. IFR VISIBILITIES CONTINUE FOR THE SOUTHERN TAF SITES
AND LANSING. RADAR INDICATES LANSING SHOULD BE CLEAR OF THE BAND IN
AN HOUR... WITH KALAMAZOO AND BATTLE CREEK IMPROVING IN ONE TO TWO
HOURS. JACKSON SHOULD CONTINUE IN THE SNOW FOR MAYBE THREE HOURS.
MVFR/VFR CEILINGS WILL IMPROVE TO VFR TONIGHT. THERE IS A CHANCE OF
SOME LAKE EFFECT SNOW MOVING OVER MUSKEGON EARLY FRIDAY WITH MVFR
CONDITIONS POSSIBLE.
WINDS OUT OF THE NORTH AND NORTHEAST AT 10 TO 15 KNOTS WITH GUSTS TO
20 KNOTS WILL FALL TO UNDER 10 KNOTS TONIGHT.
&&
.MARINE...
ISSUED AT 421 PM EST THU JAN 2 2014
THERE MAY BE A BRIEF LULL IN WAVES OVERNIGHT IN SPOTS DUE TO
LIGHT WINDS IN THE VICINITY OF A SNOW BAND THAT SHOULD PERSIST
JUST OFF THE COAST. WINDS AND WAVES WILL INCREASE TO SOLID SMALL
CRAFT CRITERIA DURING FRIDAY WITH GALES POSSIBLE BEGINNING LATE IN
THE DAY.
&&
.HYDROLOGY...
ISSUED AT 236 PM EST THU JAN 2 2014
A FLOOD ADVISORY IS IN EFFECT FOR THE FLAT RIVER AT SMYRNA. A
SUSPECTED ICE JAM UPSTREAM IS CAUSING A SHARP RISE AT THE SMYRNA
RIVER GAUGE. THE ICE JAM ON THE MUSKEGON RIVER THAT HAS IMPACTED
EVART SEEMS TO HAVE STABILIZED. THE MUSKEGON RIVER AT EVART IS NOW
ON A GRADUAL DECLINE. THE FLOOD ADVISORIES FOR THE MUSKEGON RIVER AT
EVART AND THE PERE MARQUETTE RIVER AT SCOTTVILLE HAVE BEEN CANCELED.
RIVERS WILL CONTINUE GAINING ICE COVERAGE AND THICKNESS FOR THE
FORESEEABLE FUTURE. THOSE RIVERS THAT ICE OVER COMPLETELY WILL HAVE
A MINIMAL ICE JAM THREAT. RIVERS WITH JAGGED ICE BUILDUP ARE IN
DANGER OF EXPERIENCING JAMMING AND RAPID FLUCTUATIONS. WIDESPREAD
HEAVIER SNOW IS LIKELY SUNDAY AND SUNDAY NIGHT...FOLLOWED
IMMEDIATELY BY A BLAST OF EXTREMELY COLD AIR. HOPEFULLY RIVER LEVELS
WILL LOCK IN SOMEWHAT WITH THE COLD AIR IN PLACE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR
LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...EBW
SHORT TERM...TJT
LONG TERM...63
AVIATION...63
HYDROLOGY...EBW
MARINE...TJT
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
329 PM EST THU JAN 2 2014
LATEST UPDATE...
LONG TERM
.SYNOPSIS...
ISSUED AT 236 PM EST THU JAN 2 2014
THE BIG WEATHER STORY IS THE COLD OUTBREAK EXPECTED EARLY NEXT WEEK.
HIGHS IN THE SINGLE DIGITS AND LOWS IN THE 0 TO 10 BELOW RANGE ARE
EXPECTED. WIND CHILLS COULD DROP AS LOW AS 25 BELOW ON MONDAY AND
TUESDAY. WIND GUSTS ARE FORECAST TO BE AROUND 20 TO 30 MPH.
ANOTHER VERY COLD NIGHT IS IN STORE WITH LOWS IN THE 0 TO 5 BELOW
RANGE. SOME LIGHT SNOW NEAR THE LAKESHORE IS POSSIBLE FRIDAY.
WIDESPREAD HEAVIER SNOW WILL MOVE IN SUNDAY AND SUNDAY NIGHT.
SIGNIFICANT ACCUMULATIONS APPEAR LIKELY AT THIS TIME...ESPECIALLY
SOUTH AND EAST OF GRAND RAPIDS.
TEMPERATURES WILL MODERATE CONSIDERABLY ON SATURDAY BEFORE THE
ARCTIC AIR PLUNGES BACK IN. HIGHS ON SATURDAY WILL BE NEAR 30
DEGREES.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 303 PM EST THU JAN 2 2014
MAIN CHALLENGE IN THE VERY SHORT TERM IS ASSESSING SNOW POTENTIAL
NEAR THE LAKESHORE...PARTICULARLY AROUND THE SABLE POINTS OF MASON
AND OCEANA COUNTIES. A DOMINANT LAKE SNOW BAND NEAR THE WESTERN LAKE
MICHIGAN SHORELINE THIS MORNING IS SLOWLY DRIFTING EAST. THE LAST
SEVERAL HRRR MODEL RUNS...AS WELL AS THE NAM...APPEAR TO BE PLACING
OR MOVING THIS FEATURE TOO FAR EAST TOWARDS THE POINTS.
IT IS LOOKING MORE LIKELY THAT WE WILL CLEAR OUT OVER INLAND ZONES
TONIGHT...ALLOWING FOR VERY COLD INLAND TEMPERATURES FRIDAY MORNING
AND A LAND BREEZE THAT HAS A GOOD CHANCE OF KEEPING THE SNOW BAND
OFFSHORE. DISCUSSED THIS WITH THE GAYLORD OFFICE AND WE BOTH CONCUR
THAT THIS IS THE MOST LIKELY SCENARIO AT THIS POINT. HAVE THEREFORE
TRIMMED POPS AND ACCUMULATIONS EXCEPT FOR THE IMMEDIATE COAST.
STILL LOOKING FAVORABLE FOR LIGHT LAKE ENHANCED SNOW FRIDAY AHEAD OF
THE NEXT CLIPPER. DID NOT CHANGE THE INHERITED FORECAST
SIGNIFICANTLY. FROM FRIDAY NIGHT THROUGH SATURDAY POPS INCREASE FROM
NORTHWEST TO SOUTHEAST AHEAD OF THE CLIPPER AND ASSOCIATED COLD
FRONT WHICH SHOULD BE ENTERING THE FORECAST AREA BY SATURDAY EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH THURSDAY)
ISSUED AT 328 PM EST THU JAN 2 2014
THE MEDIUM RANGE MODELS CONTINUE IN GOOD AGREEMENT ON THE LARGE
SCALE FLOW WITH MINOR DIFFERENCES IN THE SMALLER SCALE FEATURES.
CONFIDENCE IS HIGH DUE TO CONTINUITY IN TIME AND SPACE. WIND CHILL
VALUES AND SNOWFALL ARE THE CHALLENGES WITH THIS FORECAST PACKAGE.
TEMPERATURES WILL FALL TO 0-5 DEGREES SUNDAY NIGHT AND ON MONDAY THE
HIGHS WILL BE AROUND 5 DEGREES ABOVE ZERO. THE LOWS MONDAY NIGHT
WILL BE BELOW ZERO. VALUES THIS LOW HAVE NOT BEEN SEEN IN THIS AREA
SINCE FEB 2007. THE TEMPERATURES WILL BEGIN TO RECOVER WEDNESDAY.
ALONG WITH THE COLD AIR... STRONG GUSTY WINDS OUT OF THE WEST AND
NORTHWEST WILL PRODUCE LOW WIND CHILL VALUES. THE COLDEST WIND
CHILLS... BETWEEN 20 AND 30 DEGREES BELOW ZERO ARE POSSIBLE MONDAY
EVENING INTO TUESDAY MORNING. A WIND CHILL ADVISORY AND MAYBE A WIND
CHILL WARNING WILL BE NEEDED MONDAY AFTERNOON THROUGH TUESDAY
AFTERNOON.
THIS ALSO SEEMS TO BE A SNOWY PERIOD OF TIME. AN UPPER LOW WILL DROP
SOUTH FROM NEAR THE POLE AND MOVE EAST ACROSS SOTHERN CANADA THROUGH
THE LONG TERM. THIS AND SHORTWAVES MOVING THROUGH THE FLOW AROUND
THE LOW WILL BRING THE COLD AIR... CYCLONIC FLOW AND SNOW. A FEW
SHORTWAVES SHOULD PASS CLOSE ENOUGH TO THE AREA TO RESULT IN SNOW
SATURDAY NIGHT THROUGH SUNDAY NIGHT. THE UPPER LOW WILL HELP TO BUMP
UP THE LAKE EFFECT SNOW MONDAY INTO WEDNESDAY AS THE SYSTEM PULLS
AWAY. WITH THE COLD TEMPERATURES... THE LAKE EFFECT SNOW IS EXPECTED
TO BE IN THE FORM OF SMALL ICE CRYSTALS. THEREFORE THE SNOW WILL NOT
STACK UP... BUT THE STRONG WINDS WILL BLOW THIS SNOW AROUND. THIS
WILL RESULT IN GREATLY REDUCED VISIBILITIES. THIS WILL ESPECIALLY BE
TRUE NEAR LAKE MICHIGAN.
A MORE ZONAL FLOW PATTERN WILL ENSUE WEDNESDAY... AS A LOW PRESSURE
SYSTEM BEGINS MOVING BY TO THE SOUTH OF THE REGION. THIS HAS THE
POTENTIAL FOR ADDITIONAL SNOWFALL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1254 PM EST THU JAN 2 2014
THE BAND OF SNOW IS FINALLY DIMINISHING AND PULLING OUT OF THE
FORECAST AREA. IFR VISIBILITIES CONTINUE FOR THE SOUTHERN TAF SITES
AND LANSING. RADAR INDICATES LANSING SHOULD BE CLEAR OF THE BAND IN
AN HOUR... WITH KALAMAZOO AND BATTLE CREEK IMPROVING IN ONE TO TWO
HOURS. JACKSON SHOULD CONTINUE IN THE SNOW FOR MAYBE THREE HOURS.
MVFR/VFR CEILINGS WILL IMPROVE TO VFR TONIGHT. THERE IS A CHANCE OF
SOME LAKE EFFECT SNOW MOVING OVER MUSKEGON EARLY FRIDAY WITH MVFR
CONDITIONS POSSIBLE.
WINDS OUT OF THE NORTH AND NORTHEAST AT 10 TO 15 KNOTS WITH GUSTS TO
20 KNOTS WILL FALL TO UNDER 10 KNOTS TONIGHT.
&&
.MARINE...
ISSUED AT 330 AM EST THU JAN 2 2014
ISSUED A SMALL CRAFT ADVISORY FROM 18Z TODAY THROUGH 18Z FRIDAY.
SOUTHWEST WINDS WILL PICK UP IN ADVANCE OF THE NEXT CLIPPER. ALSO
ISSUED A GALE WATCH FOR FRIDAY NIGHT AND SATURDAY. WINDS BEHIND THE
ARCTIC FRONT WILL BE RATHER GUSTY.
&&
.HYDROLOGY...
ISSUED AT 236 PM EST THU JAN 2 2014
A FLOOD ADVISORY IS IN EFFECT FOR THE FLAT RIVER AT SMYRNA. A
SUSPECTED ICE JAM UPSTREAM IS CAUSING A SHARP RISE AT THE SMYRNA
RIVER GAUGE. THE ICE JAM ON THE MUSKEGON RIVER THAT HAS IMPACTED
EVART SEEMS TO HAVE STABILIZED. THE MUSKEGON RIVER AT EVART IS NOW
ON A GRADUAL DECLINE. THE FLOOD ADVISORIES FOR THE MUSKEGON RIVER AT
EVART AND THE PERE MARQUETTE RIVER AT SCOTTVILLE HAVE BEEN CANCELED.
RIVERS WILL CONTINUE GAINING ICE COVERAGE AND THICKNESS FOR THE
FORESEEABLE FUTURE. THOSE RIVERS THAT ICE OVER COMPLETELY WILL HAVE
A MINIMAL ICE JAM THREAT. RIVERS WITH JAGGED ICE BUILDUP ARE IN
DANGER OF EXPERIENCING JAMMING AND RAPID FLUCTUATIONS. WIDESPREAD
HEAVIER SNOW IS LIKELY SUNDAY AND SUNDAY NIGHT...FOLLOWED
IMMEDIATELY BY A BLAST OF EXTREMELY COLD AIR. HOPEFULLY RIVER LEVELS
WILL LOCK IN SOMEWHAT WITH THE COLD AIR IN PLACE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR
LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...EBW
SHORT TERM...TJT
LONG TERM...63
AVIATION...63
HYDROLOGY...EBW
MARINE...93
AREA FORECAST DISCUSSION
NWS GRAND RAPIDS MI
305 PM EST THU JAN 2 2014
LATEST UPDATE...
SHORT TERM
.SYNOPSIS...
ISSUED AT 236 PM EST THU JAN 2 2014
THE BIG WEATHER STORY IS THE COLD OUTBREAK EXPECTED EARLY NEXT WEEK.
HIGHS IN THE SINGLE DIGITS AND LOWS IN THE 0 TO 10 BELOW RANGE ARE
EXPECTED. WIND CHILLS COULD DROP AS LOW AS 25 BELOW ON MONDAY AND
TUESDAY. WIND GUSTS ARE FORECAST TO BE AROUND 20 TO 30 MPH.
ANOTHER VERY COLD NIGHT IS IN STORE WITH LOWS IN THE 0 TO 5 BELOW
RANGE. SOME LIGHT SNOW NEAR THE LAKESHORE IS POSSIBLE FRIDAY.
WIDESPREAD HEAVIER SNOW WILL MOVE IN SUNDAY AND SUNDAY NIGHT.
SIGNIFICANT ACCUMULATIONS APPEAR LIKELY AT THIS TIME...ESPECIALLY
SOUTH AND EAST OF GRAND RAPIDS.
TEMPERATURES WILL MODERATE CONSIDERABLY ON SATURDAY BEFORE THE
ARCTIC AIR PLUNGES BACK IN. HIGHS ON SATURDAY WILL BE NEAR 30
DEGREES.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 303 PM EST THU JAN 2 2014
MAIN CHALLENGE IN THE VERY SHORT TERM IS ASSESSING SNOW POTENTIAL
NEAR THE LAKESHORE...PARTICULARLY AROUND THE SABLE POINTS OF MASON
AND OCEANA COUNTIES. A DOMINANT LAKE SNOW BAND NEAR THE WESTERN LAKE
MICHIGAN SHORELINE THIS MORNING IS SLOWLY DRIFTING EAST. THE LAST
SEVERAL HRRR MODEL RUNS...AS WELL AS THE NAM...APPEAR TO BE PLACING
OR MOVING THIS FEATURE TOO FAR EAST TOWARDS THE POINTS.
IT IS LOOKING MORE LIKELY THAT WE WILL CLEAR OUT OVER INLAND ZONES
TONIGHT...ALLOWING FOR VERY COLD INLAND TEMPERATURES FRIDAY MORNING
AND A LAND BREEZE THAT HAS A GOOD CHANCE OF KEEPING THE SNOW BAND
OFFSHORE. DISCUSSED THIS WITH THE GAYLORD OFFICE AND WE BOTH CONCUR
THAT THIS IS THE MOST LIKELY SCENARIO AT THIS POINT. HAVE THEREFORE
TRIMMED POPS AND ACCUMULATIONS EXCEPT FOR THE IMMEDIATE COAST.
STILL LOOKING FAVORABLE FOR LIGHT LAKE ENHANCED SNOW FRIDAY AHEAD OF
THE NEXT CLIPPER. DID NOT CHANGE THE INHERITED FORECAST
SIGNIFICANTLY. FROM FRIDAY NIGHT THROUGH SATURDAY POPS INCREASE FROM
NORTHWEST TO SOUTHEAST AHEAD OF THE CLIPPER AND ASSOCIATED COLD
FRONT WHICH SHOULD BE ENTERING THE FORECAST AREA BY SATURDAY EVENING.
.LONG TERM...(SATURDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 330 AM EST THU JAN 2 2014
DANGEROUSLY COLD AIR... THAT WE HAVE NOT SEEN SINCE FEB 2007... WILL
SWEEP INTO MICHIGAN ON MONDAY WITH WIND CHILLS FALLING TO AS LOW AS
-25 BY THE END OF THE DAY. THIS COULD HAVE SIGNIFICANT IMPACT
ESPECIALLY SINCE IT IS THE FIRST DAY BACK TO SCHOOL OR WORK FOR
MANY.
PRIOR TO THE ARRIVAL OF THE COLD AIR... WE MAY SEE A DECENT ROUND OF
SYNOPTIC SNOW ON SUNDAY AND SUNDAY NIGHT AS A SFC LOW PASSES THROUGH
THE OHIO VALLEY REGION. SEVERAL INCHES APPEAR POSSIBLE MAINLY FOR
AREAS SOUTH AND EAST OF GRR... BUT THE EXACT TRACK OF THE SYSTEM IS
STILL UNCLEAR.
LAKE EFFECT SNOW SHOWERS WILL ACCOMPANY THE BITTERLY COLD AIR ON
MONDAY AND MONDAY NIGHT ALTHOUGH LITTLE ACCUMULATION IS EXPECTED
DURING THIS TIME SINCE THE VERY COLD AIR WILL LEAD TO VERY
SMALL/FINE FLAKE SIZE. HOWEVER SOME BLOWING SNOW IS LIKELY AT LEAST
ALONG THE LAKESHORE WHERE WINDS SHOULD BE QUITE STRONG WITH GUSTS TO
40-45 MPH. THIS WILL LIMIT VISIBILITIES AND PROBABLY CREATE SOME
TRAVEL ISSUES DESPITE THE LIMITED ACCUMULATIONS.
THE REALLY COLD -30C H8 AIR LINGERS INTO TUESDAY THEN LIFTS OUT BY
MID WEEK. LAKE EFFECT SNOWS COULD INCREASE DURING THIS TIME AS THE
DGZ LIFTS BACK INTO THE CLOUD LAYER.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1254 PM EST THU JAN 2 2014
THE BAND OF SNOW IS FINALLY DIMINISHING AND PULLING OUT OF THE
FORECAST AREA. IFR VISIBILITIES CONTINUE FOR THE SOUTHERN TAF SITES
AND LANSING. RADAR INDICATES LANSING SHOULD BE CLEAR OF THE BAND IN
AN HOUR... WITH KALAMAZOO AND BATTLE CREEK IMPROVING IN ONE TO TWO
HOURS. JACKSON SHOULD CONTINUE IN THE SNOW FOR MAYBE THREE HOURS.
MVFR/VFR CEILINGS WILL IMPROVE TO VFR TONIGHT. THERE IS A CHANCE OF
SOME LAKE EFFECT SNOW MOVING OVER MUSKEGON EARLY FRIDAY WITH MVFR
CONDITIONS POSSIBLE.
WINDS OUT OF THE NORTH AND NORTHEAST AT 10 TO 15 KNOTS WITH GUSTS TO
20 KNOTS WILL FALL TO UNDER 10 KNOTS TONIGHT.
&&
.MARINE...
ISSUED AT 330 AM EST THU JAN 2 2014
ISSUED A SMALL CRAFT ADVISORY FROM 18Z TODAY THROUGH 18Z FRIDAY.
SOUTHWEST WINDS WILL PICK UP IN ADVANCE OF THE NEXT CLIPPER. ALSO
ISSUED A GALE WATCH FOR FRIDAY NIGHT AND SATURDAY. WINDS BEHIND THE
ARCTIC FRONT WILL BE RATHER GUSTY.
&&
.HYDROLOGY...
ISSUED AT 236 PM EST THU JAN 2 2014
A FLOOD ADVISORY IS IN EFFECT FOR THE FLAT RIVER AT SMYRNA. A
SUSPECTED ICE JAM UPSTREAM IS CAUSING A SHARP RISE AT THE SMYRNA
RIVER GAUGE. THE ICE JAM ON THE MUSKEGON RIVER THAT HAS IMPACTED
EVART SEEMS TO HAVE STABILIZED. THE MUSKEGON RIVER AT EVART IS NOW
ON A GRADUAL DECLINE. THE FLOOD ADVISORIES FOR THE MUSKEGON RIVER AT
EVART AND THE PERE MARQUETTE RIVER AT SCOTTVILLE HAVE BEEN CANCELED.
RIVERS WILL CONTINUE GAINING ICE COVERAGE AND THICKNESS FOR THE
FORESEEABLE FUTURE. THOSE RIVERS THAT ICE OVER COMPLETELY WILL HAVE
A MINIMAL ICE JAM THREAT. RIVERS WITH JAGGED ICE BUILDUP ARE IN
DANGER OF EXPERIENCING JAMMING AND RAPID FLUCTUATIONS. WIDESPREAD
HEAVIER SNOW IS LIKELY SUNDAY AND SUNDAY NIGHT...FOLLOWED
IMMEDIATELY BY A BLAST OF EXTREMELY COLD AIR. HOPEFULLY RIVER LEVELS
WILL LOCK IN SOMEWHAT WITH THE COLD AIR IN PLACE.
&&
.GRR WATCHES/WARNINGS/ADVISORIES...
MI...NONE.
LM...GALE WATCH FROM FRIDAY EVENING THROUGH SATURDAY AFTERNOON FOR
LMZ844>849.
SMALL CRAFT ADVISORY UNTIL 1 PM EST FRIDAY FOR LMZ844>849.
&&
$$
SYNOPSIS...EBW
SHORT TERM...TJT
LONG TERM...MEADE
AVIATION...63
HYDROLOGY...EBW
MARINE...93
AREA FORECAST DISCUSSION
NWS HASTINGS NE
1209 PM CST THU JAN 2 2014
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 409 AM CST THU JAN 2 2014
MAIN FORECAST CONCERN FOR THE SHORT TERM PERIOD LIES WITH SOME
LIGHT SNOW CHANCES AND TRICKY HIGH TEMPERATURES FOR TODAY.
QUIET CONDITIONS REMAIN IN PLACE ACROSS THE CWA EARLY THIS
MORNING...AND WE CONTINUE TO SIT UNDER NORTHWESTERLY FLOW IN THE
UPPER LEVELS AS A LARGE AREA OF LOW PRESSURE CONTINUES TO SPIN
OVER ERN CANADA...WITH YESTERDAYS SNOW-PRODUCING DISTURBANCE
MOVING INTO THE MIDWEST...WHILE RIDGING REMAINS OFF THE WEST
COAST. A STOUT ~130KT UPPER LEVEL JET STREAK NOSING IN FROM THE
NORTH BEHIND THE TROUGH AXIS...HELPING DRIVE SOME LIGHT
SNOW/FLURRIES...WITH INCREASED RADAR RETURNS JUST NORTH OF THE
CWA. SKIES ACROSS THE CWA CURRENTLY MOSTLY CLOUDY/OVERCAST THANKS
TO A BAND OF MAINLY LOWER LEVEL STRATUS STRETCHED FROM THE NRN
ROCKIES INTO CENTRAL KS. AT THE SURFACE...HIGH PRESSURE DRAPED
GENERALLY THROUGH THE ERN PORTIONS OF THE CENTRAL PLAINS IS
KEEPING WINDS ON THE LIGHT/VARIABLE SIDE...WITH MORE OF A WESTERLY
COMPONENT DEVELOPING ACROSS WRN LOCATIONS.
THIS MORNING...THAT UPPER LEVEL JET STREAK REMAINS IN THE
AREA...AND WILL CONTINUE TO BRING THE POTENTIAL FOR SOME LIGHT
SNOW/FLURRIES TO MAINLY THE NORTHEASTERN HALF OF THE CWA. WITH
UPSTREAM OBS SHOWING VISIBILITIES DROPPING AT TIMES INTO THE 2-3
MILE RANGE...PERHAPS A FEW AREAS COULD MAYBE PICK UP A TENTH OF AN
INCH OR SO OF SNOW ACCUMULATION...SO HAVE SOME LOW POPS GOING.
OTHERWISE THE REST OF THE SHORT TERM REMAINS DRY. KEPT HIGH SKY
COVER VALUES GOING THIS MORNING...BUT SATELLITE IMAGERY SUGGESTS
THE WRN EDGE OF THAT BAND OF CLOUD COVER ISNT FAR OUTSIDE THE WRN
EDGE OF THE CWA...AND MODELS ARENT IN TOO BAD OF AGREEMENT SHOWING
THE HIGHER CLOUD COVER TRANSITIONING TO MAINLY AFFECT THE
NORTHEASTERN HALF OF THE CWA...WITH MORE SUN POTENTIAL FURTHER
SOUTHWEST.
LOOKING AT TEMPERATURES...HIGHS FOR TODAY ARE TRICKY...AND
CONFIDENCE IS NOT HIGH. WHILE WINDS ARE MAINLY ON THE
LIGHT/VARIABLE TO WESTERLY SIDE CURRENTLY...MODELS SHOW THE CWA
BEING AFFECTED BY A BACKDOOR COLD FRONT SLIDING IN FROM THE
NORTH/NORTHEAST THIS MORNING...AND THE POSITION OF THIS FRONT
THROUGH THE DAY WILL HAVE A BIG IMPACT ON WHAT TEMPS GET TO TODAY.
THERE ARE DIFFERENCES BETWEEN MODELS WITH TIMING/LOCATION. LOOKING
AT MIDDAY...THE 07Z HRRR AND 09Z RAP /THE RAP HAS DONE FAIRLY
WELL THE LAST FEW DAYS WITH HIGHS/ SHOW THE FRONT ROUGHLY ALONG A
BBW TO CNK LINE THROUGH THE CWA...VS OTHER MODELS WHICH FURTHER
WEST BY THEN...CLOSER TO A LBF TO RSL LINE. MAYBE NOT A HUGE
DIFFERENCE...BUT THE SLOWER PROGRESS OF THE BOUNDARY...WITH THE
WESTERLY WINDS AHEAD OF THE FRONT...WOULD ALLOW WRN AND POSSIBLY
CENTRAL PORTIONS OF THE CWA /INCLUDING THE TRI CITIES/ TO REACH
HIGHER TEMPS BEFORE THE EASTERLY WINDS ACCOMPANYING THE FRONT TAKE
OVER AND TEMPS DONT REALLY GO ANYWHERE. THIS LOOKS TO BE THE STORY
WITH NERN PORTIONS OF THE CWA...WHICH WILL COME UNDER THE
INFLUENCE OF THOSE E/NERLY WINDS EARLY ON IN THE DAY. DONT WANT TO
COMPLETELY DISCOUNT OR BUY FULLY INTO WHAT THE RAP/HRRR
SUGGEST...SO HIGHS ARE A BLEND...RANGING FROM ARND 10 DEGREES IN
THE NORTHEAST...TO MID 30S IN THE SW. OVERNIGHT LOWS TONIGHT LOOK
TO FALL BACK INTO THE LOW SINGLE DIGITS EAST TO MID TEENS WEST.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 409 AM CST THU JAN 2 2014
GUIDANCE FROM THE NAM...OPERATIONAL GFS...EC AND SREF-MEAN ALL
SUGGEST A MID LEVEL SHORT WAVE WILL MOVE FROM THE NORTHWESTERN
CONUS...SOUTHEAST INTO PORTIONS OF THE CENTRAL PLAINS FRIDAY INTO
SATURDAY. THE NAM SUGGESTS A NEARLY CONTINUOUS ~70KT MID LEVEL JET
STREAM AXIS WILL EXTEND FROM COLORADO TO THE GREAT LAKES REGION AT
18Z SATURDAY. THE OPERATIONAL GFS AND EC ON THE OTHER HAND BOTH
SUGGEST A BREAK IN THIS MID LEVEL JET AXIS OVER THE CENTRAL PLAINS
WILL ALLOW THE RIGHT-REAR QUADRANT OF A DEPARTING JET STREAK...AND
THE LEFT-FRONT QUADRANT OF AN INCOMING JET STREAK...TO SET UP FROM
WESTERN KANSAS INTO SOUTHEASTERN NEBRASKA AT 18Z SATURDAY. DPVA
AND MID LEVEL THERMAL ADVECTION AHEAD OF THE INCOMING MID LEVEL
SHORTWAVE DO NOT APPEAR OVERLY STRONG AND THE NAM RESPONDS BY
KEEPING OUR AREA DRY THROUGH THE WEEKEND. THE OPERATIONAL GFS AND
EC ON THE OTHER HAND BOTH SUGGEST ENHANCED OMEGA DUE TO DIRECT AND
INDIRECT THERMAL CIRCULATIONS FROM THE AFOREMENTIONED JET STREAKS
WILL PROMOTE A PERIOD OF LIGHT PRECIPITATION OVER PORTIONS OF OUR
AREA SATURDAY INTO SATURDAY EVENING...PRIMARILY ACROSS OUR SOUTH.
GIVEN THIS...WENT AHEAD WITH LOW POPS ACROSS OUR SOUTH 18Z
SATURDAY THROUGH 06Z SUNDAY ACROSS OUR SOUTH. A SECONDARY MID
LEVEL SHORTWAVE IS THEN EXPECTED TO SWEEP SOUTH/SOUTHEAST ACROSS
PORTIONS OF THE NORTHERN AND CENTRAL PLAINS SUNDAY INTO SUNDAY
NIGHT...WITH ENOUGH DPVA AND MID LEVEL THERMAL ADVECTION FOR LIGHT
PRECIPITATION ACROSS OUR AREA. ALLBLEND RESPONDED BY PRESENTING
~20% POPS TO MUCH OF THE AREA AND THESE POPS WERE LEFT UNCHANGED
FOR THE MOST PART. AN OVERALL LACK IN OMEGA SHOULD THEN PROVIDE
DRY CONDITIONS THROUGH THE REMAINDER OF THE LONG TERM FORECAST
PERIOD.
INCORPORATING THE DRY NAM FORECAST FOR SATURDAY AFTERNOON AND
SATURDAY EVENING...AS WELL AS A BLEND OF THE OPERATIONAL GFS AND
EC...PROVIDES LIQUID PRECIPITATION GENERALLY IN THE 0.01-0.04"
RANGE. SURFACE TEMPERATURES DURING THIS EVENT ARE CURRENTLY
EXPECTED TO RANGE FROM THE UPPER 20S TO AROUND 15...WHICH SUGGESTS
SNOW-WATER RATIOS GENERALLY IN THE 10-20:1 RANGE. THIS PROVIDES
SNOWFALL ACCUMULATION FROM A COUPLE TENTHS OF AN INCH TO PERHAPS
ONE INCH ACROSS OUR SOUTH 18Z SATURDAY THROUGH 06Z SUNDAY.
SNOWFALL RATES ALSO DO NOT LOOK OVERLY IMPRESSIVE SUNDAY INTO
SUNDAY NIGHT WITH PERHAPS ANOTHER INCH OF SNOWFALL ACCUMULATION
POSSIBLE ACROSS MUCH OF THE CWA.
BY FAR THE BIGGEST STORY OF THE LONG TERM FORECAST PERIOD WILL BE
THE VERY COLD TEMPERATURES WHICH LOOK TO INFILTRATE OUR AREA DURING
THE EARLY PART OF NEXT WEEK. WHILE THE COLDEST LOW LEVEL AIRMASS IS
EXPECTED TO RESIDE OVER PORTIONS OF THE UPPER MISSISSIPPI VALLEY
SUNDAY THROUGH TUESDAY...OUR AREA WILL NOT BE SPARED THE AFFECTS
OF THIS FRIGID AIR MASS AS GUIDANCE SUGGESTS SUB-ZERO READINGS
WILL BE REALIZED SUNDAY NIGHT AND MONDAY NIGHT. IN
ADDITION...STRONG LOW LEVEL COLD AIR ADVECTION ON MONDAY WILL
LIKELY KEEP HIGHS IN THE SINGLE DIGITS FOR MOST LOCATIONS ACROSS
THE CWA. THESE COLD TEMPERATURES WILL HELP PROMOTE WIND CHILL
READINGS GENERALLY IN THE -15 TO -25 DEGREE RANGE ACROSS MUCH OF
THE CWA EARLY MONDAY MORNING...WITH WIND CHILL VALUES PERHAPS
APPROACHING -30 ACROSS OUR EXTREME NORTHEAST. WILL GO AHEAD AND
MAINTAIN THE WIND CHILL WORDING IN THE HWO FOR MONDAY MORNING. THE
LOW LEVEL WIND FIELD APPEARS AS THOUGH IT WILL WEAKEN CONSIDERABLY
BY TUESDAY MORNING SO EVEN THOUGH EARLY TUESDAY MORNING LOWS WILL
BE COMPARABLE TO MONDAY...WIND CHILL VALUES ON TUESDAY MORNING DO
NOT APPEAR AS THROUGH THEY WILL DROP BELOW -10 DEGREES.
&&
.AVIATION...(FOR THE 18Z KGRI TAF THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1155 AM CST THU JAN 2 2014
THE EDGE OF STRATUS ALONG A STATIONARY FRONT WILL CONTINUE TO
MEANDER NEAR KGRI THROUGH THE AFTERNOON AND EVENING HOURS...AND
EXPECT PREVAILING MVFR CIGS TO CONTINUE...ALBEIT COULD SEE SOME
BRIEF BREAKS THROUGH ABOUT 03/06Z. THEREAFTER...SKIES WILL BEGIN
TO CLEAR...BUT INCREASING SOUTHERLY WINDS ARE EXPECTED AS THE
PRESSURE GRADIENT TIGHTENS BEHIND AN AREA OF SURFACE HIGH
PRESSURE SLIDING SOUTH ACROSS MISSOURI AND ARKANSAS. COULD SEE
SOME WIND SHEAR OVERNIGHT AS THE LOW LEVEL JET WILL APPROACH 40KTS
NEAR 2KFT...BUT LEFT MENTION OUT OF CURRENT TAF AS SURFACE WINDS
WILL ALSO BE INCREASING...EVENTUALLY GUSTING OVER 20KTS BY
03/13Z.
&&
.GID WATCHES/WARNINGS/ADVISORIES...
NE...NONE.
KS...NONE.
&&
$$
SHORT TERM...ADO
LONG TERM...BRYANT
AVIATION...ROSSI
AREA FORECAST DISCUSSION
NWS RALEIGH NC
256 PM EST THU JAN 02 2014
.SYNOPSIS...A POTENT UPPER LEVEL TROUGH AND ATTENDANT SURFACE LOW
PRESSURE SYSTEM WILL APPROACH THE CAROLINAS FROM THE WEST TODAY. A
STRONG COLD FRONT WILL CROSS CENTRAL NC THIS EVENING. COLD HIGH
PRESSURE WILL BUILD INTO THE REGION IN THE WAKE OF THE FRONT ON
FRIDAY AND FRIDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM THURSDAY...
LIGHT...ISENTROPICALLY DRIVEN PRECIP INLAND OF AN INVERTED COASTAL
TROUGH IS MOSTLY EAST OF I-95 THIS MORNING. BASED ON RAP 295-305K
LAYER ISENTROPIC ANALYSIS...THIS SHOULD GENERALLY BE THE CASE
THROUGH MIDDAY... PRIOR TO THE ARRIVAL OF A STRONGER SHORTWAVE AND
QG FORCING APPROACHING FROM THE WEST. THE HRRR SHOWS PRECIP
BEGINNING TO FILL IN OVER THE SOUTHERN AND WESTERN CWA AFTER
17Z...ALBEIT MOSTLY LIGHT QPF AMOUNTS OF LESS THAN 0.20" WITH LOWER
PW VALUES TO THE WEST AND LIMITED MOISTURE ABOVE -10C. CATEGORICAL
POPS IN THE CURRENT FORECAST LOOK GOOD...SO THE MAIN CHANGES TO THE
FORECAST WILL JUST BE TO ADJUST TEMPS BASED ON CURRENT TRENDS.
THINNER OVERCAST AND LACK OF PRECIP OVER THE WESTERN PIEDMONT HAS
ALLOWED FOR A LITTLE QUICKER CLIMB THIS MORNING...BUT STRATUS IS
THICKENING FROM THE SOUTHWEST AND ADDITIONAL WARM SHOULD BE VERY
SLOW TO OCCUR. HAVE LOWERED HIGHS A COUPLE DEGREES IN THE NORTHWEST
PIEDMONT...YIELDING 45-50 NORTHWEST TO SOUTHEAST. -SMITH
TONIGHT...A STRONG COLD FRONT ASSOCIATED WITH THE MID-UPPER LEVEL
S/W WILL SWEEP ACROSS CENTRAL NC DURING THE EVENING HOURS. THE
PASSAGE OF THE FRONT WILL BE NOTED BY THE SFC WINDS VEERING TOT HE
NW AND INCREASING TO AROUND 15KTS WITH FREQUENT GUSTS AROUND 25KTS.
THIS NW WIND WILL ADVECT MUCH COLDER AND DRIER AIR INTO CENTRAL NC.
THIS WILL LEAD TO A RAPID DISSIPATION OF THE PRECIPITATION FROM WEST-
TO-EAST IN THE EARLY EVENING WITH CLEARING SKIES OCCURRING SHORTLY
THEREAFTER. MODEL TEMP GUIDANCE HAS BEEN TRENDING COOLER WHICH SEEMS
REASONABLE CONSIDERING UPSTREAM CONDITIONS...SO HAVE FOLLOWED SUIT.
MIN TEMPS BY EARLY FRIDAY IN THE MID 20S NW TO THE LOWER 30S SE.
THESE COLD TEMPS ALONG WITH A BLUSTERY NW WIND WILL SEND WIND CHILL
VALUES DOWN INTO THE TEENS ACROSS THE PIEDMONT BY EARLY FRIDAY
MORNING.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 PM THURSDAY...
SURFACE HIGH PRESSURE WILL BE CENTERED OVER CENTRAL NC WITH MOSTLY
ZONAL FLOW ALOFT. THIS SHOULD KEEP SKIES RELATIVELY CLEAR. A WEAK
WARM AIR ADVECTION REGIME IN THE UPPER LEVELS AND THE DEVELOPMENT OF
RETURN FLOW AROUND THE HIGH AS IT MOVES EASTWARDS WILL HELP MAX
TEMPS CLIMB INTO THE LOW 40S NW TO UPPER 40S SE. AS THE HIGH MOVES
OFFSHORE CLOUD COVER WILL BEGIN TO INCREASE FROM THE SOUTH AND
SURFACE SOUTHERLY FLOW WILL HELP MODERATE LOW TEMPERATURES SATURDAY
NIGHT INTO SUNDAY MORNING INTO THE LOW TO MID 30S AS OPPOSED TO THE
MID-TEENS OF FRIDAY NIGHT/SATURDAY MORNING.
ON SUNDAY MORNING A WEAK IN-SITU CAD SCENARIO WILL DEVELOP WITH THE
SURFACE HIGH MOVING OFF OF THE EASTERN SEABOARD. WITH TEMPERATURES
NEAR THE FREEZING MARK EXPECTED FOR LOWS SUNDAY MORNING AND WET BULB
TEMPERATURES A FEW DEGREES BELOW FREEZING...THERE IS THE POSSIBILITY
FOR SOME FREEZING RAIN BEFORE 8AM IN THE TRIAD. BOTH THE FREEZING
TEMPERATURES AND PRECIPITATION MAY BE LIMITED AND SO THE CHANCES OF
THIS BEING A HIGH IMPACT FREEZING RAIN EVENT ARE LOW. WILL CONTINUE
TO MONITOR TEMPERATURE AND PRECIPITATION TRENDS FOR ANY INCREASED
THREAT BUT FOR NOW WOULD EXPECT MOST FREEZING RAIN TO OCCUR ON
ELEVATED SURFACES AND BRIDGES AND OVERPASSES. TEMPERATURES WILL
REBOUND VERY QUICKLY SUNDAY MORNING AS A DEVELOPING LOW PRESSURE
SYSTEM WEST OF THE MOUNTAINS WILL HELP TO BREAK UP THE CAD BEFORE IT
REALLY EVER GETS STARTED. SOUTHERLY FLOW WILL DEVELOP AHEAD OF THE
FRONTAL SYSTEM AND TEMPERATURES SUNDAY AFTERNOON WILL RAING FROM THE
UPPER 40S NW TO LOWER 60S SE. LOWS SUNDAY NIGHT GENERALLY MIDDLE 30S
TO MIDDLE 40S NW TO SE.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 PM THURSDAY...
THE FRONT WILL MOVE ACROSS THE AREA MONDAY IN THE FORM OF LIQUID
PRECIPITATION BEFORE EXITING TO THE EAST ON MONDAY NIGHT. HIGH TEMPS
MONDAY WILL BE LINKED TO THE PROGRESSION OF THE FRONT. GENERALLY LOW
40S TO MID 50S NW TO SE. QPF ASSICIATED WITH THE FRONT SHOULD BE
AROUND A QUARTER OF AN INCH AT THE MOST.
DRY BUT COLD WILL BE THE THEME FOR THE LONG TERM FROM TUESDAY ON OUT
WITH AN UPPER LEVEL TROUGH PUSHING THROUGH THE AREA ALONG WITH A
1040 MB SURFACE HIGH MOVING THROUGH THE MISSISSIPPI VALLEY. MODERATE
TO STRONG NORTHERLY WINDS AT THE SURFACE WITH STRONG NORTHWESTERLY
WINDS ALOFT WILL BRING A VERY COLD ARCTIC AIRMASS INTO THE REGION.
RECORD LOW TEMPERATURES ARE POSSIBLE AT GSO AND RDU ON MONDAY NIGHT
TUESDAY MORNING WITH LOWS IN THE LOW TO MIDDLE TEENS EXPECTED WITH
WIND CHILLS IN THE SINGLE DIGITS. ONCE THE SURFACE HIGH MOVES
EASTWARD A SLOW WARMING TREND WILL PREVAIL FROM HIGHS IN TEH UPPER
20S TO MID 30S TUESDAY AND LOWS IN THE MID TEENS TO HIGHS IN THE LOW
TO UPPER 40S THURSDAY AND LOWS IN THE LOW TO MID 30S THURSDAY NIGHT.
&&
.AVIATION /18Z THURSDAY THROUGH MONDAY/...
AS OF 105 PM THURSDAY...
A STEADY STREAM OF LIGHT TO MODERATE RAIN ALONG THE NC COAST PLAIN
IS CONTRIBUTING TO IFR AND LIFR CEILINGS FROM KFAY TO NEAR
KRWI...WHILE MVFR CEILINGS ARE SPREADING INTO THE WESTERN PIEDMONT
AHEAD OF A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST.
CONDITIONS ARE EXPECTED TO REMAIN LOW...OR DETERIORATE IN AREAS
WHERE VFR IS CURRENTLY OBSERVED...THERE IS HIGH CONFIDENCE IN A
PERIOD OF AT LEAST IFR CEILINGS BETWEEN 18Z/02 AND 03Z/03...BEFORE A
STRONG COLD FRONT SWEEPS ACROSS THE AREA OVERNIGHT. AS SKIES CLEAR
BEHIND THE FRONT...STRONG NORTHWESTERLY (CROSSWINDS) WINDS MAY GUST
AS HIGH AS 25-30KT...CONTINUING INTO THE DAY ON FRIDAY BEFORE
RELAXING DURING THE AFTERNOON AND EVENING HOURS.
OUTLOOK... SUB-VFR CEILINGS (MOSTLY MVFR) ARE POSSIBLE SATURDAY
NIGHT AS ANOTHER LOW PRESSURE SYSTEM IMPACTS THE AREA. VFR
CONDITIONS ARE THEN EXPECTED NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...ELLIS
LONG TERM...ELLIS
AVIATION...SMITH
AREA FORECAST DISCUSSION
NWS RALEIGH NC
105 PM EST THU JAN 02 2014
.SYNOPSIS...A POTENT UPPER LEVEL TROUGH AND ATTENDANT SURFACE LOW
PRESSURE SYSTEM WILL APPROACH THE CAROLINAS FROM THE WEST TODAY. A
STRONG COLD FRONT WILL CROSS CENTRAL NC THIS EVENING. COLD HIGH
PRESSURE WILL BUILD INTO THE REGION IN THE WAKE OF THE FRONT ON
FRIDAY AND FRIDAY NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 940 AM THURSDAY...
LIGHT...ISENTROPICALLY DRIVEN PRECIP INLAND OF AN INVERTED COASTAL
TROUGH IS MOSTLY EAST OF I-95 THIS MORNING. BASED ON RAP 295-305K
LAYER ISENTROPIC ANALYSIS...THIS SHOULD GENERALLY BE THE CASE
THROUGH MIDDAY... PRIOR TO THE ARRIVAL OF A STRONGER SHORTWAVE AND
QG FORCING APPROACHING FROM THE WEST. THE HRRR SHOWS PRECIP
BEGINNING TO FILL IN OVER THE SOUTHERN AND WESTERN CWA AFTER
17Z...ALBEIT MOSTLY LIGHT QPF AMOUNTS OF LESS THAN 0.20" WITH LOWER
PW VALUES TO THE WEST AND LIMITED MOISTURE ABOVE -10C. CATEGORICAL
POPS IN THE CURRENT FORECAST LOOK GOOD...SO THE MAIN CHANGES TO THE
FORECAST WILL JUST BE TO ADJUST TEMPS BASED ON CURRENT TRENDS.
THINNER OVERCAST AND LACK OF PRECIP OVER THE WESTERN PIEDMONT HAS
ALLOWED FOR A LITTLE QUICKER CLIMB THIS MORNING...BUT STRATUS IS
THICKENING FROM THE SOUTHWEST AND ADDITIONAL WARM SHOULD BE VERY
SLOW TO OCCUR. HAVE LOWERED HIGHS A COUPLE DEGREES IN THE NORTHWEST
PIEDMONT...YIELDING 45-50 NORTHWEST TO SOUTHEAST. -SMITH
TONIGHT...A STRONG COLD FRONT ASSOCIATED WITH THE MID-UPPER LEVEL
S/W WILL SWEEP ACROSS CENTRAL NC DURING THE EVENING HOURS. THE
PASSAGE OF THE FRONT WILL BE NOTED BY THE SFC WINDS VEERING TOT HE
NW AND INCREASING TO AROUND 15KTS WITH FREQUENT GUSTS AROUND 25KTS.
THIS NW WIND WILL ADVECT MUCH COLDER AND DRIER AIR INTO CENTRAL NC.
THIS WILL LEAD TO A RAPID DISSIPATION OF THE PRECIPITATION FROM WEST-
TO-EAST IN THE EARLY EVENING WITH CLEARING SKIES OCCURRING SHORTLY
THEREAFTER. MODEL TEMP GUIDANCE HAS BEEN TRENDING COOLER WHICH SEEMS
REASONABLE CONSIDERING UPSTREAM CONDITIONS...SO HAVE FOLLOWED SUIT.
MIN TEMPS BY EARLY FRIDAY IN THE MID 20S NW TO THE LOWER 30S SE.
THESE COLD TEMPS ALONG WITH A BLUSTERY NW WIND WILL SEND WIND CHILL
VALUES DOWN INTO THE TEENS ACROSS THE PIEDMONT BY EARLY FRIDAY
MORNING.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
AS OF 315 AM THURSDAY...
FRIDAY AND FRIDAY NIGHT...ARCTIC-LIKE AIR MASS WILL SETTLE OVER
CENTRAL NC AS THE PARENT HIGH PRESSURE SYSTEM BUILDS INTO AND
SETTLES OVERHEAD BY FRIDAY NIGHT. SUSTAINED WINDS NEAR 20 MPH WITH
GUSTS 30-35 MPH WILL BE COMMON FRIDAY MORNING AFTERWHICH THE WINDS
WILL GRADUALLY SUBSIDE IN THE AFTERNOON. COULD SEE A FEW GUSTS
BETWEEN 40-45 MPH BUT BELIEVE THIS OCCURRENCE WILL BE LIMITED/FAIRLY
RANDOM. THUS...WILL NOT ISSUE A WIND ADVISORY WITH THIS PACKAGE BUT
LATER FORECAST ISSUANCES MAY NEED TO CONSIDER ONE. MAX TEMPS FRIDAY
WILL BE CLOSE TO 20 DEGREES BELOW NORMAL AS MAX TEMPS SHOULD RANGE
FROM THE LOW-MID 30S NORTH TO UPPER 30S TO NEAR 40 SOUTH.
UNDER CLEAR SKIES AND A SUBSIDING WIND REGIME...TEMPS WILL PLUMMET
AFTER SUNSET. AGAIN...MOS GUIDANCE HAS COME IN A LITTLE COLDER AND
PLAN TO ADJUST MIN TEMPS IN A SIMILAR FASHION. MIN TEMPS SHOULD
RANGE FROM THE MIDDLE TEENS IN THE OUTLYING AREAS...TO THE UPPER
TEENS AROUND 20 IN THE MORE URBANIZED LOCATIONS. -WSS
SATURDAY: ARCTIC HIGH PRESSURE OVER THE AREA TO START THE DAY ON
SATURDAY COUPLED WITH ONLY SHALLOW AFTERNOON MIXING WILL LEAD TO
WELL BELOW NORMAL TEMPS FOR SATURDAY... DESPITE THE HIGH MOVING
OFFSHORE ALLOWING FOR RETURN FLOW TO DEVELOP. GIVEN THIS AND BRIEF
MID LEVEL RIDGING ACROSS THE AREA EXPECT WE WILL SEE MOSTLY SUNNY
SKIES WITH HIGH TEMPS IN THE LOWER TO MID 40S. -BSD
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
AS OF 320 AM THURSDAY...
SATURDAY NIGHT THROUGH MONDAY: A MID/UPPER LEVEL TROUGH WILL DEEPEN
SATURDAY INTO SUNDAY ACROSS THE CENTRAL U.S. AND BEGIN TO MOVE
EASTWARD ALLOWING ARCTIC AIR TO FLOOD INTO THE CENTRAL AND
EVENTUALLY EASTERN U.S. BEHIND AN ASSOCIATED ARCTIC COLD FRONT.
AHEAD OF THE FRONT ACROSS OUR AREA ON SATURDAY NIGHT INTO SUNDAY
EXPECT WE WILL SEE ISENTROPIC LIFT INCREASE AS 850 MB WINDS ACROSS
OUR WESTERN PIEDMONT INCREASE INTO THE 30 TO 40 KT RANGE SATURDAY
NIGHT INTO SUNDAY. WITH THE INCREASE MOISTURE AND SHALLOW ISENTROPIC
LIFT NWP GUIDANCE IS SHOWING SOME PRECIP DEVELOPING ACROSS OUR
WESTERN /NORTHWESTERN PIEDMONT VERY LATE SATURDAY INTO SUNDAY
MORNING. BOTH THE NAM AND GFS BUFR SOUNDING SHOW THE MOISTURE WILL
BE QUITE SHALLOW... WITH SATURATION NOT EVEN REACHING -10 DEGREES
CELSIUS. HOWEVER... FORECAST WETBULB TEMPS ARE EXPECTED TO BE BELOW
FREEZING ACROSS THE WESTERN AND NORTHWESTERN PIEDMONT WHEN PRECIP
MAY BEGIN TO MOVE INTO THE AREA EARLY SUNDAY MORNING... GIVEN THE
DRY AIR DEPOSITED BY THE ARCTIC SURFACE HIGH. THUS... EXPECT WE
COULD SEE A IN-SITU CAD AIRMASS DEVELOP... WITH POSSIBLY A FEW HOURS
OF FREEZING RAIN IN THE IN THE FAVORED NORTHWEST/WESTERN PIEDMONT.
THUS... HAVE ADDED RAIN AND/OR FREEZING RAIN WORDING TO THE FORECAST
WHEN TEMPS ARE EXPECTED TO BE 32 F OR LESS AND PRECIP IS IN THE
FORECAST FOR SUNDAY MORNING. GIVEN THE LATENT HEAT RELEASE FROM
PHASE CHANGE AND NO CONTINUED SOURCE OF DRY COLD AIR EXPECTED...
FREEZING RAIN SHOULD NOT LAST LONG AND ONLY BE A "NUISANCE" TYPE
EVENT... WITH ALL RAIN EXPECTED BY 15Z SUNDAY (GIVEN CURRENT TIMING
OF THE PRECIP AND ONLY A COUPLE TENTHS OF AN INCH AT BEST OF LIQUID
). WILL SHOW THE HIGHEST POPS IN THE NORTHWEST/WEST WHERE MOISTURE
AND LIFT APPEAR TO BE MAXIMIZED.
THIS FIRST AREA OF PRECIP WILL BEGIN TO LIFT OFF TO THE NORTHEAST OF
THE AREA ON SUNDAY AFTERNOON AS THE ARCTIC SURFACE FRONT APPROACHES
THE CENTRAL AND SOUTHERN APPALACHIAN MOUNTAINS. THIS CREATES A
DIFFICULT TEMP FORECAST... WITH THE POSSIBLE LINGERING CAD AIRMASS.
FOR NOW WILL LOWER HIGHS IN THE NORTHWEST AND RAISE HIGHS A BIT IN
THE SOUTHEAST. THIS YIELDS HIGH TEMP RANGING FROM THE MID 40S NW
(WHICH MAY BE TOO WARM) TO LOWER TO MID 60S SE.
THE ARCTIC FRONT IS EXPECTED TO MOVE THROUGH THE AREA EARLY MONDAY
MORNING... WITH THE BULK OF THE COLD AIR POSSIBLY DELAYED A BIT...
AS THE GFS AND ECMWF DIFFER IN HOW FAST THE LOW LEVEL THICKNESS
VALUES WILL PLUNGE AND THE COLD AIR ROARS IN HERE. FOR NOW WILL SHOW
TEMPS RANGING FROM THE LOWER 40S NW TO THE MID 50S E... WITH LOWS
MONDAY MORNING IN THE MID 30S TO THE LOWER 40S... WITH POSSIBLY A
FEW SHOWERS ACCOMPANYING THE FRONT AND MAYBE EVEN A FEW SNOW SHOWERS
ACROSS THE FAR NORTH/NORTHWEST (STILL TOO EARLY TO TELL IF THE COLD
AIR WILL BE ABLE TO CAUGHT UP WITH THE PRECIP).
MONDAY NIGHT THROUGH WEDNESDAY: ARCTIC HIGH PRESSURE WILL BUILD
ACROSS THE AREA DURING THIS TIME FRAME WITH SOME THE COLDEST AIR OF
THE SEASON... WITH HIGHS ON TUESDAY STRUGGLING TO REACH 30 DEGREES
FOR SOME LOCATIONS. THUS... EXPECT DRY BUT COLD CONDITIONS DURING
THIS TIME FRAME WITH WELL BELOW NORMAL TEMPS.
&&
.AVIATION /18Z THURSDAY THROUGH MONDAY/...
AS OF 105 PM THURSDAY...
A STEADY STREAM OF LIGHT TO MODERATE RAIN ALONG THE NC COAST PLAIN
IS CONTRIBUTING TO IFR AND LIFR CEILINGS FROM KFAY TO NEAR
KRWI...WHILE MVFR CEILINGS ARE SPREADING INTO THE WESTERN PIEDMONT
AHEAD OF A LOW PRESSURE SYSTEM APPROACHING FROM THE WEST.
CONDITIONS ARE EXPECTED TO REMAIN LOW...OR DETERIORATE IN AREAS
WHERE VFR IS CURRENTLY OBSERVED...THERE IS HIGH CONFIDENCE IN A
PERIOD OF AT LEAST IFR CEILINGS BETWEEN 18Z/02 AND 03Z/03...BEFORE A
STRONG COLD FRONT SWEEPS ACROSS THE AREA OVERNIGHT. AS SKIES CLEAR
BEHIND THE FRONT...STRONG NORTHWESTERLY (CROSSWINDS) WINDS MAY GUST
AS HIGH AS 25-30KT...CONTINUING INTO THE DAY ON FRIDAY BEFORE
RELAXING DURING THE AFTERNOON AND EVENING HOURS.
OUTLOOK... SUB-VFR CEILINGS (MOSTLY MVFR) ARE POSSIBLE SATURDAY
NIGHT AS ANOTHER LOW PRESSURE SYSTEM IMPACTS THE AREA. VFR
CONDITIONS ARE THEN EXPECTED NEXT WEEK.
&&
.RAH WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SYNOPSIS...WSS
NEAR TERM...WSS/SMITH
SHORT TERM...WSS/BSD
LONG TERM...BSD
AVIATION...SMITH