Forecast Discussions mentioning any of
"HRRR" "RAP" "RR" "RUC13" "RUC" received at GSD on 01/03/15
AREA FORECAST DISCUSSION...UPDATE FOR AVIATION
NWS LITTLE ROCK AR
1150 AM CST THU JAN 1 2015
.AVIATION...
OVERALL VFR CEILINGS AND FLIGHT CONDITIONS WILL START THE FORECAST.
THE AREA OF MAINLY LIGHT TO PATCHY MODERATE RAIN...WITH A FEW SPOTS
MIXED WITH LIGHT SLEET OR LIGHT FREEZING RAIN IN WESTERN TO
NORTHWEST AR...ARE SPREADING OVER AR. TEMPS WILL HOLD ABOVE FREEZING
OVER MOST LOCALS AND RAIN WILL BE SEEN...WITH THE GREATEST CHANCE OF
LIGHT SLEET OR LIGHT FREEZING RAIN IN WESTERN TO NORTHERN AR. PATCHY
MVFR CEILINGS WILL BE POSSIBLE WITH THE HEAVIER PRECIP AREAS. WINDS
ARE LIGHT FROM THE NE TO SE. TONIGHT...CEILINGS WILL GRADUALLY LOWER
TO MAINLY MVFR CONDITIONS WITH THE LIGHT TO AT TIMES MODERATE RAIN.
PATCHY LIGHT FREEZING RAIN AND SLEET MAY BE SEEN OVER WESTERN AND
NORTHERN AR. ICING WILL BE POSSIBLE IN CLOUDS. THE CHANCE OF RAIN
WILL CONTINUE ON FRIDAY. (59)
&&
.PREV DISCUSSION... /ISSUED 1059 AM CST THU JAN 1 2015/
.UPDATE...
PRECIPITATION HAS INCREASED ACROSS PORTIONS OF SOUTHEAST ARKANSAS
THROUGH THE MORNING HOURS...WITH ONLY A FEW BRIEF REPORTS OF SLEET
COMING IN. TEMPERATURES AROUND THE STATE THIS MORNING NOW HAVE
MOSTLY RISEN ABOVE FREEZING. THE FEW EXCEPTIONS ARE IN THE HIGHER
ELEVATIONS ACROSS WESTERN AND NORTHWEST ARKANSAS. HRRR CONTINUES
TO BRING A SECOND ROUND OF PRECIPITATION ACROSS NORTHWEST ARKANSAS
LATER THIS AFTERNOON. DO FULLY EXPECT SOME EVAPORATIVE COOLING
THROUGH THE DAY TODAY AS ENVIRONMENT MOISTENS UP. CURRENT THINKING
IS THAT THIS WILL HAVE NO NET EFFECT ON TEMPS AND THEY WILL REMAIN
STATIONARY THROUGH THE AFTERNOON. FORECAST IS IN GOOD SHAPE...AND
JUST MADE SOME MINOR TWEAKS TO TEMPERATURES TO REFLECT THE CURRENT
TRENDS.
&&
.PREV DISCUSSION... /ISSUED 625 AM CST THU JAN 1 2015/
AVIATION...01/12Z TAF CYCLE
VFR CONDS WL START OFF THE PD...BUT CONDS WL DETERIORATE TODAY AS
PRECIP DVLPS AND OVERSPREADS THE FA. PARTS OF WRN AND NRN AR WL
SEE A MIX OF LGT FRZG RAIN AND SLEET THIS MRNG BEFORE CHANGING OVR
TO JUST RAIN BY THIS AFTN. SOME FRZG DRIZZLE WL BE POSSIBLE TNGT
OVR NRN AR. ELSEWHERE...A BRIEF PD OF RAIN AND SLEET WL OCCUR THIS
MRNG BEFORE PRECIP BCMS JUST A COLD RAIN. /44/
PREV DISCUSSION... /ISSUED 231 AM CST THU JAN 1 2015/
SHORT TERM...TODAY THROUGH SUNDAY
TEMPS ACROSS THE CWA THIS MORNING ARE REMAINING STEADY IN THE 30S
FOR MOST LOCATIONS...WITH MOST LOCATIONS ABOVE FREEZING. THE CLOUD
COVER HAS KEPT THESE TEMPS FROM FALLING...AND WILL LIKELY SEE TEMPS
REMAIN STEADY THROUGH SUNRISE. DRY AIR IS IN PLACE HOWEVER...WITH
DEWPTS IN THE UPPER TEENS TO MID 20S. WATER VAPOR IMAGERY IS SHOWING
A MOISTURE PLUME STRETCHING FROM THE PACIFIC...LIFTING NE INTO TX
AND OK THIS MORNING...WITH PRECIP EVIDENT IN NRN TX AND RECENTLY SRN
OK AS SEEN IN REGIONAL RADAR IMAGERY.
AS THIS MOISTURE APPROACHES THE WRN AND SWRN COUNTIES THIS
MORNING...DO EXPECT SOME EVAPORATIVE COOLING AS MOISTURE FALLS
THROUGH THE DRY LAYER NEAR THE SFC. HAVE TEMPS DROPPING SEVERAL DEG
AT THE ONSET OF PRECIP...WHICH WILL BE THE PRIMARY TIME FOR ANY
WINTRY PRECIP. INITIALLY...A PERIOD OF SLEET AND FREEZING RAIN WILL
BE SEEN AS THE COLUMN SATURATES DURING THE MORNING HRS. GIVEN TEMPS
ARE ALREADY WARMER THAN EARLIER EXPECTED AT THIS TIME...THE
POTENTIAL FOR WIDESPREAD WINTER WX HAZARDS IS EVEN LOWER THAN
EARLIER EXPECTED. AS A RESULT...THINKING ANY SLEET OR ICE
ACCUMULATIONS WILL BE LIGHT...AND LIMITED TO THE HIGHER TERRAIN OF
THE OUACHITAS AND OZARKS...AND OTHER ISOLATED AREAS ACROSS THE FAR
WRN AND NWRN COUNTIES. ANY TRAVEL HAZARDS THIS NEW YEARS MORNING
WILL BE LIMITED TO THESE LOCATIONS...ESPECIALLY ON BRIDGES AND
OVERPASSES. WILL CONTINUE TO EMPHASIZE ANY WINTRY WX TRAVEL CONCERNS
IN AN UPDATED SPS THIS MORNING.
LOCATIONS FURTHER EAST WILL ALSO SEE SOME SLEET OR PATCHY FREEZING
RAIN AT THE ONSET OF THE PRECIP...BUT TEMPS THROUGHOUT THE ENTIRE
THERMAL PROFILE WILL WARM OVER TIME...LEADING TO JUST A COLD RAIN BY
LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON. THE HIGHEST PRECIP
RATES WILL BE ACROSS THE SRN HALF OF THE CWA WHERE TEMPS ARE
WARMEST. LIGHTER PRECIP RATES WILL BE SEEN ACROSS THE NRN
COUNTIES...WHERE TEMPS MAY REMAIN COLD ENOUGH THIS AFTERNOON TO SEE
SOME FREEZING RAIN MIX WITH THE RAIN...ESPECIALLY IN THE HIGHER
TERRAIN OF THE OZARKS AND NEAR THE MO BORDER. ONLY MINOR ICE
ACCUMULATIONS ARE EXPECTED THIS AFTERNOON IN AREAS WHERE THE
FREEZING RAIN OCCURS.
THIS EVENING...MOST LOCATIONS WILL SEE ALL RAINFALL AS TEMPS WILL
REMAIN STEADY OR EVEN WARM A DEG OR TWO BY FRI MORNING. MOST OF THE
PRECIP ACTIVITY WILL ALSO HAVE SHIFTED FURTHER SOUTH...WITH NRN
LOCATIONS LIKELY SEEING DRY CONDITIONS TONIGHT. AS A
RESULT...DROP POPS ALONG THE MO BORDER TO ONLY SLIGHT CHANCE. IF
ANY PRECIP WERE TO FALL ACROSS THE NRN COUNTIES...MAINLY RAIN IS
EXPECTED...THOUGH A FEW SPOTS IN THE HIGHER TERRAIN COULD AGAIN SEE
SOME FREEZING RAIN MIX IN WITH THE RAIN.
EVEN THIS CLOSE TO THE ONSET OF THIS MINOR WINTER WX EPISODE...THERE
DOES REMAIN SOME UNCERTAINTY REGARDING TEMPS. SOME ADJUSTMENTS IN
THE FORECAST REMAIN POSSIBLE...ESPECIALLY CONSIDERING SOME LOCATIONS
WILL BE SO NEAR THE FREEZING MARK. ANY CHANGES IN THE EXPECTED TEMPS
COULD ALTER THE POTENTIAL FROZEN PRECIP ACCUMULATION...RESULTING IN
INCREASED WINTER WX TRAVEL HAZARDS. PLEASE REFER TO THE LATEST
FORECASTS UPDATES THIS NEW YEARS DAY...ESPECIALLY IN THE HIGHER
TERRAIN OF THE OUACHITAS AND OZARKS...THE WRN COUNTIES...AND AREAS
ALONG THE MO BORDER.
ENOUGH WARMING WILL HAVE OCCURRED FOR FRI INTO SAT TO SEE ALL LIQUID
PRECIP. THE SW FLOW ALOFT WILL INTENSIFY FRI INTO SAT...WITH
WIDESPREAD SHRA AND EVEN SOME RUMBLES OF THUNDER POSSIBLE ACROSS THE
CWA. SOME LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE...THOUGH ONLY
WIDESPREAD RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE CURRENTLY EXPECTED.
AS A RESULT...A FLASH FLOOD WATCH IS NOT EXPECTED AT THIS TIME.
THE STORM SYSTEM WILL EXIT THE REGION SAT INTO SAT NIGHT...WITH
DRIER AIR MOVING INTO THE STATE BY THE AFTERNOON HRS SAT. AS A
RESULT...HAVE POPS DECREASING RAPIDLY BY SAT AFTERNOON FROM SW TO
NE. SOME LINGERING MOISTURE COULD BE SEEN ACROSS THE NRN COUNTIES
SAT NIGHT...WITH SOME SPRINKLES OR A FEW SNOW FLAKES POSSIBLE.
A COLD FRONT WILL SURGE THROUGH THE STATE ON SUN...WITH COLDER AND
DRIER CONDITIONS MOVING INTO THE REGION. CHANCES FOR ANY PRECIP WILL
BE LOW TO END THE SHORT TERM PERIOD.
LONG TERM...MONDAY THROUGH WEDNESDAY
MODELS ARE IN DECENT AGREEMENT THIS MRNG WITH OVERALL FCST TRENDS
THRU THE PD. A WESTERLY FLOW ALOFT ON MON WL EVENTUALLY TURN NWLY
FOR TUE AND WED AS A LONG WV TROF SHARPENS OVR THE ERN HALF OF THE
NATION. AS A RESULT...A SERIES OF CLIPPER TYPE SFC LOWS WL DROP SEWD
AND BRING REINFORCING SHOTS OF COLDER AIR TO AR THRU THE MIDDLE OF
THE WEEK. WITH LTL IN THE WAY OF LOW LVL MOISTURE RETURN
ANTICIPATED...THE FCST WL RMN DRY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 37 34 40 36 / 50 40 80 80
CAMDEN AR 36 36 42 40 / 100 80 90 80
HARRISON AR 35 32 40 34 / 30 20 50 80
HOT SPRINGS AR 37 34 41 38 / 90 60 90 80
LITTLE ROCK AR 38 35 41 38 / 80 60 90 80
MONTICELLO AR 37 35 42 42 / 100 80 90 80
MOUNT IDA AR 38 34 41 37 / 90 60 90 80
MOUNTAIN HOME AR 34 33 41 35 / 30 20 50 80
NEWPORT AR 37 34 40 38 / 50 50 80 80
PINE BLUFF AR 37 35 41 40 / 90 80 90 80
RUSSELLVILLE AR 37 34 41 37 / 80 40 80 80
SEARCY AR 36 33 40 37 / 60 50 90 80
STUTTGART AR 37 34 41 39 / 90 60 90 80
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
65
AREA FORECAST DISCUSSION
NWS LITTLE ROCK AR
1059 AM CST THU JAN 1 2015
.UPDATE...
PRECIPITATION HAS INCREASED ACROSS PORTIONS OF SOUTHEAST ARKANSAS
THROUGH THE MORNING HOURS...WITH ONLY A FEW BRIEF REPORTS OF SLEET
COMING IN. TEMPERATURES AROUND THE STATE THIS MORNING NOW HAVE
MOSTLY RISEN ABOVE FREEZING. THE FEW EXCEPTIONS ARE IN THE HIGHER
ELEVATIONS ACROSS WESTERN AND NORTHWEST ARKANSAS. HRRR CONTINUES
TO BRING A SECOND ROUND OF PRECIPITATION ACROSS NORTHWEST ARKANSAS
LATER THIS AFTERNOON. DO FULLY EXPECT SOME EVAPORATIVE COOLING
THROUGH THE DAY TODAY AS ENVIRONMENT MOISTENS UP. CURRENT THINKING
IS THAT THIS WILL HAVE NO NET EFFECT ON TEMPS AND THEY WILL REMAIN
STATIONARY THROUGH THE AFTERNOON. FORECAST IS IN GOOD SHAPE...AND
JUST MADE SOME MINOR TWEAKS TO TEMPERATURES TO REFLECT THE CURRENT
TRENDS.
&&
.PREV DISCUSSION... /ISSUED 625 AM CST THU JAN 1 2015/
AVIATION...01/12Z TAF CYCLE
VFR CONDS WL START OFF THE PD...BUT CONDS WL DETERIORATE TODAY AS
PRECIP DVLPS AND OVERSPREADS THE FA. PARTS OF WRN AND NRN AR WL
SEE A MIX OF LGT FRZG RAIN AND SLEET THIS MRNG BEFORE CHANGING OVR
TO JUST RAIN BY THIS AFTN. SOME FRZG DRIZZLE WL BE POSSIBLE TNGT
OVR NRN AR. ELSEWHERE...A BRIEF PD OF RAIN AND SLEET WL OCCUR THIS
MRNG BEFORE PRECIP BCMS JUST A COLD RAIN. /44/
PREV DISCUSSION... /ISSUED 231 AM CST THU JAN 1 2015/
SHORT TERM...TODAY THROUGH SUNDAY
TEMPS ACROSS THE CWA THIS MORNING ARE REMAINING STEADY IN THE 30S
FOR MOST LOCATIONS...WITH MOST LOCATIONS ABOVE FREEZING. THE CLOUD
COVER HAS KEPT THESE TEMPS FROM FALLING...AND WILL LIKELY SEE TEMPS
REMAIN STEADY THROUGH SUNRISE. DRY AIR IS IN PLACE HOWEVER...WITH
DEWPTS IN THE UPPER TEENS TO MID 20S. WATER VAPOR IMAGERY IS SHOWING
A MOISTURE PLUME STRETCHING FROM THE PACIFIC...LIFTING NE INTO TX
AND OK THIS MORNING...WITH PRECIP EVIDENT IN NRN TX AND RECENTLY SRN
OK AS SEEN IN REGIONAL RADAR IMAGERY.
AS THIS MOISTURE APPROACHES THE WRN AND SWRN COUNTIES THIS
MORNING...DO EXPECT SOME EVAPORATIVE COOLING AS MOISTURE FALLS
THROUGH THE DRY LAYER NEAR THE SFC. HAVE TEMPS DROPPING SEVERAL DEG
AT THE ONSET OF PRECIP...WHICH WILL BE THE PRIMARY TIME FOR ANY
WINTRY PRECIP. INITIALLY...A PERIOD OF SLEET AND FREEZING RAIN WILL
BE SEEN AS THE COLUMN SATURATES DURING THE MORNING HRS. GIVEN TEMPS
ARE ALREADY WARMER THAN EARLIER EXPECTED AT THIS TIME...THE
POTENTIAL FOR WIDESPREAD WINTER WX HAZARDS IS EVEN LOWER THAN
EARLIER EXPECTED. AS A RESULT...THINKING ANY SLEET OR ICE
ACCUMULATIONS WILL BE LIGHT...AND LIMITED TO THE HIGHER TERRAIN OF
THE OUACHITAS AND OZARKS...AND OTHER ISOLATED AREAS ACROSS THE FAR
WRN AND NWRN COUNTIES. ANY TRAVEL HAZARDS THIS NEW YEARS MORNING
WILL BE LIMITED TO THESE LOCATIONS...ESPECIALLY ON BRIDGES AND
OVERPASSES. WILL CONTINUE TO EMPHASIZE ANY WINTRY WX TRAVEL CONCERNS
IN AN UPDATED SPS THIS MORNING.
LOCATIONS FURTHER EAST WILL ALSO SEE SOME SLEET OR PATCHY FREEZING
RAIN AT THE ONSET OF THE PRECIP...BUT TEMPS THROUGHOUT THE ENTIRE
THERMAL PROFILE WILL WARM OVER TIME...LEADING TO JUST A COLD RAIN BY
LATER THIS MORNING AND ESPECIALLY THIS AFTERNOON. THE HIGHEST PRECIP
RATES WILL BE ACROSS THE SRN HALF OF THE CWA WHERE TEMPS ARE
WARMEST. LIGHTER PRECIP RATES WILL BE SEEN ACROSS THE NRN
COUNTIES...WHERE TEMPS MAY REMAIN COLD ENOUGH THIS AFTERNOON TO SEE
SOME FREEZING RAIN MIX WITH THE RAIN...ESPECIALLY IN THE HIGHER
TERRAIN OF THE OZARKS AND NEAR THE MO BORDER. ONLY MINOR ICE
ACCUMULATIONS ARE EXPECTED THIS AFTERNOON IN AREAS WHERE THE
FREEZING RAIN OCCURS.
THIS EVENING...MOST LOCATIONS WILL SEE ALL RAINFALL AS TEMPS WILL
REMAIN STEADY OR EVEN WARM A DEG OR TWO BY FRI MORNING. MOST OF THE
PRECIP ACTIVITY WILL ALSO HAVE SHIFTED FURTHER SOUTH...WITH NRN
LOCATIONS LIKELY SEEING DRY CONDITIONS TONIGHT. AS A
RESULT...DROP POPS ALONG THE MO BORDER TO ONLY SLIGHT CHANCE. IF
ANY PRECIP WERE TO FALL ACROSS THE NRN COUNTIES...MAINLY RAIN IS
EXPECTED...THOUGH A FEW SPOTS IN THE HIGHER TERRAIN COULD AGAIN SEE
SOME FREEZING RAIN MIX IN WITH THE RAIN.
EVEN THIS CLOSE TO THE ONSET OF THIS MINOR WINTER WX EPISODE...THERE
DOES REMAIN SOME UNCERTAINTY REGARDING TEMPS. SOME ADJUSTMENTS IN
THE FORECAST REMAIN POSSIBLE...ESPECIALLY CONSIDERING SOME LOCATIONS
WILL BE SO NEAR THE FREEZING MARK. ANY CHANGES IN THE EXPECTED TEMPS
COULD ALTER THE POTENTIAL FROZEN PRECIP ACCUMULATION...RESULTING IN
INCREASED WINTER WX TRAVEL HAZARDS. PLEASE REFER TO THE LATEST
FORECASTS UPDATES THIS NEW YEARS DAY...ESPECIALLY IN THE HIGHER
TERRAIN OF THE OUACHITAS AND OZARKS...THE WRN COUNTIES...AND AREAS
ALONG THE MO BORDER.
ENOUGH WARMING WILL HAVE OCCURRED FOR FRI INTO SAT TO SEE ALL LIQUID
PRECIP. THE SW FLOW ALOFT WILL INTENSIFY FRI INTO SAT...WITH
WIDESPREAD SHRA AND EVEN SOME RUMBLES OF THUNDER POSSIBLE ACROSS THE
CWA. SOME LOCALLY HEAVY RAINFALL WILL ALSO BE POSSIBLE...THOUGH ONLY
WIDESPREAD RAINFALL AMOUNTS OF 1 TO 2 INCHES ARE CURRENTLY EXPECTED.
AS A RESULT...A FLASH FLOOD WATCH IS NOT EXPECTED AT THIS TIME.
THE STORM SYSTEM WILL EXIT THE REGION SAT INTO SAT NIGHT...WITH
DRIER AIR MOVING INTO THE STATE BY THE AFTERNOON HRS SAT. AS A
RESULT...HAVE POPS DECREASING RAPIDLY BY SAT AFTERNOON FROM SW TO
NE. SOME LINGERING MOISTURE COULD BE SEEN ACROSS THE NRN COUNTIES
SAT NIGHT...WITH SOME SPRINKLES OR A FEW SNOW FLAKES POSSIBLE.
A COLD FRONT WILL SURGE THROUGH THE STATE ON SUN...WITH COLDER AND
DRIER CONDITIONS MOVING INTO THE REGION. CHANCES FOR ANY PRECIP WILL
BE LOW TO END THE SHORT TERM PERIOD.
LONG TERM...MONDAY THROUGH WEDNESDAY
MODELS ARE IN DECENT AGREEMENT THIS MRNG WITH OVERALL FCST TRENDS
THRU THE PD. A WESTERLY FLOW ALOFT ON MON WL EVENTUALLY TURN NWLY
FOR TUE AND WED AS A LONG WV TROF SHARPENS OVR THE ERN HALF OF THE
NATION. AS A RESULT...A SERIES OF CLIPPER TYPE SFC LOWS WL DROP SEWD
AND BRING REINFORCING SHOTS OF COLDER AIR TO AR THRU THE MIDDLE OF
THE WEEK. WITH LTL IN THE WAY OF LOW LVL MOISTURE RETURN
ANTICIPATED...THE FCST WL RMN DRY.
&&
.PRELIMINARY POINT TEMPS/POPS...
BATESVILLE AR 37 34 40 36 / 50 40 80 80
CAMDEN AR 36 36 42 40 / 100 80 90 80
HARRISON AR 35 32 40 34 / 30 20 50 80
HOT SPRINGS AR 37 34 41 38 / 90 60 90 80
LITTLE ROCK AR 38 35 41 38 / 80 60 90 80
MONTICELLO AR 37 35 42 42 / 100 80 90 80
MOUNT IDA AR 38 34 41 37 / 90 60 90 80
MOUNTAIN HOME AR 34 33 41 35 / 30 20 50 80
NEWPORT AR 37 34 40 38 / 50 50 80 80
PINE BLUFF AR 37 35 41 40 / 90 80 90 80
RUSSELLVILLE AR 37 34 41 37 / 80 40 80 80
SEARCY AR 36 33 40 37 / 60 50 90 80
STUTTGART AR 37 34 41 39 / 90 60 90 80
&&
.LZK WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
65
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
900 AM MST THU JAN 1 2015
...FREEZING TEMPERATURES LIKELY AT MANY LOWER DESERT LOCATIONS AGAIN
TONIGHT...
.SYNOPSIS...
THE STRONG AND VERY COLD STORM SYSTEM THAT BROUGHT RAIN AND LOW
ELEVATION SNOWFALL TO THE DESERT SOUTHWEST WILL SLOWLY MOVE OFF TO
THE EAST TODAY. IN ITS WAKE...WELL BELOW NORMAL TEMPERATURES WILL
PERSIST ACROSS THE REGION THROUGH SUNDAY. HIGH PRESSURE BUILDING IN
FROM THE WEST WILL BRING A GRADUAL WARMING TREND FRIDAY THROUGH THE
MIDDLE PART OF NEXT WEEK.
&&
.DISCUSSION...
AFTER A RATHER INTERESTING NEW YEAR/S EVE...WHICH SAW NUMEROUS
REPORTS OF SNOW FLURRIES ACROSS THE GREATER PHX AREA JUST BEFORE
MIDNIGHT...THIS MORNING HAS STARTED OUT ON THE COLD SIDE...WITH MOST
OUTLYING LOWER DESERT LOCATIONS REPORTING LOWS AT/BELOW FREEZING.
CURRENTLY...OUTSIDE OF SOME MID-LEVEL CLOUDINESS ACROSS
SOUTH-CENTRAL ARIZONA...MOST AREAS ARE SEEING THE RETURN OF SUNNY TO
PARTLY SUNNY SKIES. TODAY STILL APPEARS IT WILL BE A RATHER COLD
ONE...WITH 850MB TEMPS REMAINING IN THE -2 TO -4C
RANGE...SUPPORTING HIGH TEMPS ONLY IN THE MID-40 TO LOWER-50
RANGE...IN SPITE OF THE EXPECTED SUNSHINE. AS FAR AS THE VERY SHORT
TERM IS CONCERNED...OTHER THAN SOME MINOR ADJUSTMENTS TO REDUCE POPS
AND TO THE TEMP AND DEWPOINT GRIDS...CURRENT GRIDS AND ZONE
FORECASTS STILL LOOK GOOD...AND NO FURTHER UPDATES ARE PLANNED.
&&
.PREVIOUS DISCUSSION...
WELL-DEFINED VORT MAX CONTINUES TO SLIDE EASTWARD ACROSS NORTHERN AZ
EARLY THIS MORNING. ELONGATED BAND OF COOLER CLOUDS ASSOCIATED WITH
STRONG JET AND VORTICITY-FORCED ASCENT HAS PUSHED STEADILY EASTWARD
INTO NORTHERN AND EASTERN AZ. LAST GASP OF PRECIPITATION ACROSS THE
PHOENIX AREA WAS IN THE FORM OF LIGHT SNOW ACROSS MANY SPOTS JUST
BEFORE MIDNIGHT. EVEN IN THE LOWEST ELEVATIONS OF THE VALLEY...A MIX
OF RAIN AND SNOW WAS OBSERVED.
FOR THIS MORNING...GLOBAL AND HI-RES GUIDANCE INCLUDING THE HRRR ARE
IN GOOD AGREEMENT THAT LIGHT SNOW WILL CONTINUE TO TAPER OFF ACROSS
SOUTHERN GILA COUNTY WITH LITTLE ADDITIONAL ACCUMULATION. END TIME
OF THE WINTER STORM WARNING FOR THE HIGHER ELEVATIONS OF SOUTHERN
GILA COUNTY HAS BEEN TRIMMED TO 6 AM. WITH A SUBSIDENT FLOW
EXPECTED...POPS WERE ALSO LOWERED ACROSS THESE AREAS AND IN THE
LOWER DESERTS THROUGH THIS AFTERNOON. NEVERTHELESS...SCATTERED
CLOUDS WILL WRAP AROUND THE DEPARTING LOW PRESSURE SYSTEM PRODUCING
PARTLY CLOUDY SKIES AND ISOLATED SNOW FLURRIES.
AFTER A VERY COLD MORNING...TEMPERATURES WILL AGAIN STRUGGLE TO
REACH THE 50 DEGREE MARK...MARKING THE COLDEST MAX TEMPERATURES
SINCE THE FREEZING EVENT IN JANUARY 2013. THE COLD AFTERNOON WILL
SET THE STAGE FOR ANOTHER COLD NIGHT. MOSTLY CLEAR SKIES AND LIGHT
WINDS IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM WILL PROMOTE
RADIATIONAL COOLING AND A FREEZE WARNING REMAINS IN EFFECT FOR MUCH
OF THE LOWER DESERTS INCLUDING THE PHOENIX AREA. LATEST STATISTICAL
GUIDANCE HAS TRENDED SOMEWHAT COLDER AND IMPERIAL COUNTY WAS ALSO
ADDED TO THE WARNING.
OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT THROUGH THE
EXTENDED...INDICATING THAT PACIFIC HIGH PRESSURE WILL BUILD ACROSS
THE REGION. THIS WILL RESULT IN DRY CONDITIONS ALONG WITH INCREASING
THICKNESSES AND A GRADUAL WARMING TREND THROUGH THE MIDDLE OF NEXT
WEEK. HOWEVER...TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MONDAY
WITH COLD MORNINGS. A FREEZE WARNING MAY ULTIMATELY BE NEEDED FOR
PORTIONS OF THE AREA AGAIN SATURDAY MORNING.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
MOIST BOUNDARY LAYER CONDITIONS REMAIN ACROSS THE AREA WITH PATCHES
OF LOW VFR STRATOCU PERSISTING ACROSS SOUTH-CENTRAL ARIZONA. THE
STRATOCU DECK AT 4-5K FEET WILL AFFECT THE PHOENIX TERMINALS FOR A
GOOD PORTION OF THIS MORNING AND POSSIBLY INTO THE AFTERNOON. CIGS
FOR THIS AFTERNOON AND EVENING WILL RISE TO AROUND 6K FEET AND
SHOULD BE MORE SCATTERED. LIGHT WINDS WILL DOMINATE THROUGH THE
PERIOD AND GENERALLY FOLLOW TYPICAL DIURNAL WIND PATTERNS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR TO MOSTLY CLEAR SKIES AND LIGHT WINDS WILL LAST THROUGH AT
LEAST FRIDAY MORNING. NO AVIATION IMPACTS EXPECTED.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
A REBOUND IN TEMPERATURES WILL HAPPEN THIS WEEKEND INTO NEXT WITH
HIGHS REACHING NORMALS BY NEXT MONDAY AND WARMING EVEN FURTHER BY
NEXT WEDNESDAY. MINIMUM RELATIVE HUMIDITIES OF 15 TO 30 PERCENT ON
SATURDAY WILL GRADUALLY LOWER THROUGH THE PERIOD WITH VALUES IN THE
TEENS TO LOWER 20S FOR NEXT TUESDAY AND WEDNESDAY. WINDS WILL REMAIN
LIGHT THROUGH THE PERIOD UNDER STRONG HIGH PRESSURE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FREEZE WARNING UNTIL 9 AM MST THIS MORNING AZZ020>022-026>028.
FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM MST FRIDAY
AZZ020>023-026>028.
WINTER STORM WARNING UNTIL 6 AM MST EARLY THIS MORNING ABOVE
3500 FEET FOR AZZ024.
CA...FREEZE WARNING UNTIL 8 AM PST THIS MORNING CAZ033.
FREEZE WARNING FROM 10 PM THIS EVENING TO 8 AM PST FRIDAY
CAZ033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...PERCHA/HIRSCH
AVIATION....KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
512 AM MST THU JAN 1 2015
...FREEZING TEMPERATURES LIKELY AT MANY LOWER DESERT LOCATIONS THIS
MORNING AND AGAIN TONIGHT...
.SYNOPSIS...
THE STRONG AND VERY COLD STORM SYSTEM THAT BROUGHT RAIN AND LOW
ELEVATION SNOWFALL TO THE DESERT SOUTHWEST WILL SLOWLY MOVE OFF TO
THE EAST TODAY. IN ITS WAKE...WELL BELOW NORMAL TEMPERATURES WILL
PERSIST ACROSS THE REGION THROUGH SUNDAY. HIGH PRESSURE BUILDING IN
FROM THE WEST WILL BRING A GRADUAL WARMING TREND FRIDAY THROUGH THE
MIDDLE PART OF NEXT WEEK.
&&
.DISCUSSION...
WELL-DEFINED VORT MAX CONTINUES TO SLIDE EASTWARD ACROSS NORTHERN AZ
EARLY THIS MORNING. ELONGATED BAND OF COOLER CLOUDS ASSOCIATED WITH
STRONG JET AND VORTICITY-FORCED ASCENT HAS PUSHED STEADILY EASTWARD
INTO NORTHERN AND EASTERN AZ. LAST GASP OF PRECIPITATION ACROSS THE
PHOENIX AREA WAS IN THE FORM OF LIGHT SNOW ACROSS MANY SPOTS JUST
BEFORE MIDNIGHT. EVEN IN THE LOWEST ELEVATIONS OF THE VALLEY...A MIX
OF RAIN AND SNOW WAS OBSERVED.
FOR THIS MORNING...GLOBAL AND HI-RES GUIDANCE INCLUDING THE HRRR ARE
IN GOOD AGREEMENT THAT LIGHT SNOW WILL CONTINUE TO TAPER OFF ACROSS
SOUTHERN GILA COUNTY WITH LITTLE ADDITIONAL ACCUMULATION. END TIME
OF THE WINTER STORM WARNING FOR THE HIGHER ELEVATIONS OF SOUTHERN
GILA COUNTY HAS BEEN TRIMMED TO 6 AM. WITH A SUBSIDENT FLOW
EXPECTED...POPS WERE ALSO LOWERED ACROSS THESE AREAS AND IN THE
LOWER DESERTS THROUGH THIS AFTERNOON. NEVERTHELESS...SCATTERED
CLOUDS WILL WRAP AROUND THE DEPARTING LOW PRESSURE SYSTEM PRODUCING
PARTLY CLOUDY SKIES AND ISOLATED SNOW FLURRIES.
AFTER A VERY COLD MORNING...TEMPERATURES WILL AGAIN STRUGGLE TO
REACH THE 50 DEGREE MARK...MARKING THE COLDEST MAX TEMPERATURES
SINCE THE FREEZING EVENT IN JANUARY 2013. THE COLD AFTERNOON WILL
SET THE STAGE FOR ANOTHER COLD NIGHT. MOSTLY CLEAR SKIES AND LIGHT
WINDS IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM WILL PROMOTE
RADIATIONAL COOLING AND A FREEZE WARNING REMAINS IN EFFECT FOR MUCH
OF THE LOWER DESERTS INCLUDING THE PHOENIX AREA. LATEST STATISTICAL
GUIDANCE HAS TRENDED SOMEWHAT COLDER AND IMPERIAL COUNTY WAS ALSO
ADDED TO THE WARNING.
OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT THROUGH THE
EXTENDED...INDICATING THAT PACIFIC HIGH PRESSURE WILL BUILD ACROSS
THE REGION. THIS WILL RESULT IN DRY CONDITIONS ALONG WITH INCREASING
THICKNESSES AND A GRADUAL WARMING TREND THROUGH THE MIDDLE OF NEXT
WEEK. HOWEVER...TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MONDAY
WITH COLD MORNINGS. A FREEZE WARNING MAY ULTIMATELY BE NEEDED FOR
PORTIONS OF THE AREA AGAIN SATURDAY MORNING.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
MOIST BOUNDARY LAYER CONDITIONS REMAIN ACROSS THE AREA WITH PATCHES
OF LOW VFR STRATOCU PERSISTING ACROSS SOUTH-CENTRAL ARIZONA. THE
STRATOCU DECK AT 4-5K FEET WILL AFFECT THE PHOENIX TERMINALS FOR A
GOOD PORTION OF THIS MORNING AND POSSIBLY INTO THE AFTERNOON. CIGS
FOR THIS AFTERNOON AND EVENING WILL RISE TO AROUND 6K FEET AND
SHOULD BE MORE SCATTERED. LIGHT WINDS WILL DOMINATE THROUGH THE
PERIOD AND GENERALLY FOLLOW TYPICAL DIURNAL WIND PATTERNS.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
CLEAR TO MOSTLY CLEAR SKIES AND LIGHT WINDS WILL LAST THROUGH AT
LEAST FRIDAY MORNING. NO AVIATION IMPACTS EXPECTED.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
SATURDAY THROUGH WEDNESDAY...
A REBOUND IN TEMPERATURES WILL HAPPEN THIS WEEKEND INTO NEXT WITH
HIGHS REACHING NORMALS BY NEXT MONDAY AND WARMING EVEN FURTHER BY
NEXT WEDNESDAY. MINIMUM RELATIVE HUMIDITIES OF 15 TO 30 PERCENT ON
SATURDAY WILL GRADUALLY LOWER THROUGH THE PERIOD WITH VALUES IN THE
TEENS TO LOWER 20S FOR NEXT TUESDAY AND WEDNESDAY. WINDS WILL REMAIN
LIGHT THROUGH THE PERIOD UNDER STRONG HIGH PRESSURE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FREEZE WARNING UNTIL 9 AM MST THIS MORNING AZZ020>022-026>028.
FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM MST FRIDAY
AZZ020>023-026>028.
WINTER STORM WARNING UNTIL 6 AM MST EARLY THIS MORNING ABOVE
3500 FEET FOR AZZ024.
CA...FREEZE WARNING UNTIL 8 AM PST THIS MORNING CAZ033.
FREEZE WARNING FROM 10 PM THIS EVENING TO 8 AM PST FRIDAY CAZ033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....KUHLMAN
FIRE WEATHER...KUHLMAN
AREA FORECAST DISCUSSION
NWS PHOENIX AZ
335 AM MST THU JAN 1 2015
...FREEZING TEMPERATURES LIKELY AT MANY LOWER DESERT LOCATIONS THIS
MORNING AND AGAIN TONIGHT...
.SYNOPSIS...
THE STRONG AND VERY COLD STORM SYSTEM THAT BROUGHT RAIN AND LOW
ELEVATION SNOWFALL TO THE DESERT SOUTHWEST WILL SLOWLY MOVE OFF TO
THE EAST TODAY. IN ITS WAKE...WELL BELOW NORMAL TEMPERATURES WILL
PERSIST ACROSS THE REGION THROUGH SUNDAY. HIGH PRESSURE BUILDING IN
FROM THE WEST WILL BRING A GRADUAL WARMING TREND FRIDAY THROUGH THE
MIDDLE PART OF NEXT WEEK.
&&
.DISCUSSION...
WELL-DEFINED VORT MAX CONTINUES TO SLIDE EASTWARD ACROSS NORTHERN AZ
EARLY THIS MORNING. ELONGATED BAND OF COOLER CLOUDS ASSOCIATED WITH
STRONG JET AND VORTICITY-FORCED ASCENT HAS PUSHED STEADILY EASTWARD
INTO NORTHERN AND EASTERN AZ. LAST GASP OF PRECIPITATION ACROSS THE
PHOENIX AREA WAS IN THE FORM OF LIGHT SNOW ACROSS MANY SPOTS JUST
BEFORE MIDNIGHT. EVEN IN THE LOWEST ELEVATIONS OF THE VALLEY...A MIX
OF RAIN AND SNOW WAS OBSERVED.
FOR THIS MORNING...GLOBAL AND HI-RES GUIDANCE INCLUDING THE HRRR ARE
IN GOOD AGREEMENT THAT LIGHT SNOW WILL CONTINUE TO TAPER OFF ACROSS
SOUTHERN GILA COUNTY WITH LITTLE ADDITIONAL ACCUMULATION. END TIME
OF THE WINTER STORM WARNING FOR THE HIGHER ELEVATIONS OF SOUTHERN
GILA COUNTY HAS BEEN TRIMMED TO 6 AM. WITH A SUBSIDENT FLOW
EXPECTED...POPS WERE ALSO LOWERED ACROSS THESE AREAS AND IN THE
LOWER DESERTS THROUGH THIS AFTERNOON. NEVERTHELESS...SCATTERED
CLOUDS WILL WRAP AROUND THE DEPARTING LOW PRESSURE SYSTEM PRODUCING
PARTLY CLOUDY SKIES AND ISOLATED SNOW FLURRIES.
AFTER A VERY COLD MORNING...TEMPERATURES WILL AGAIN STRUGGLE TO
REACH THE 50 DEGREE MARK...MARKING THE COLDEST MAX TEMPERATURES
SINCE THE FREEZING EVENT IN JANUARY 2013. THE COLD AFTERNOON WILL
SET THE STAGE FOR ANOTHER COLD NIGHT. MOSTLY CLEAR SKIES AND LIGHT
WINDS IN THE WAKE OF THE DEPARTING LOW PRESSURE SYSTEM WILL PROMOTE
RADIATIONAL COOLING AND A FREEZE WARNING REMAINS IN EFFECT FOR MUCH
OF THE LOWER DESERTS INCLUDING THE PHOENIX AREA. LATEST STATISTICAL
GUIDANCE HAS TRENDED SOMEWHAT COLDER AND IMPERIAL COUNTY WAS ALSO
ADDED TO THE WARNING.
OPERATIONAL MODELS REMAIN IN EXCELLENT AGREEMENT THROUGH THE
EXTENDED...INDICATING THAT PACIFIC HIGH PRESSURE WILL BUILD ACROSS
THE REGION. THIS WILL RESULT IN DRY CONDITIONS ALONG WITH INCREASING
THICKNESSES AND A GRADUAL WARMING TREND THROUGH THE MIDDLE OF NEXT
WEEK. HOWEVER...TEMPERATURES WILL REMAIN BELOW NORMAL THROUGH MONDAY
WITH COLD MORNINGS. A FREEZE WARNING MAY ULTIMATELY BE NEEDED FOR
PORTIONS OF THE AREA AGAIN SATURDAY MORNING.
&&
.AVIATION...
SOUTH-CENTRAL ARIZONA INCLUDING KPHX...KIWA AND KSDL...
BROAD AREA OF LOWER LEVEL STRATUS COVERS MUCH OF THE LOWER CENTRAL
AZ DESERTS...WITH VARYING LAYERS AND BREAKS IN THE CLOUD DECK. WILL
LOOK FOR PERIODS OF MVFR CIGS AT PHX AREA TERMINALS THROUGH THE
EVENING...BUT CONDITIONS WILL NOT REMAIN AS SOCKED IN AS THEY WERE
DURING THE DAY. CIGS AROUND THE 5500-6000FT LAYER MAY HOLD THROUGH
SUNRISE AND TERRAIN OBSCURATIONS WILL ALSO PERSIST. WX RADAR SCOPES
STILL SHOW SCATTERED LIGHT SHOWERS OVER EASTERN PORTIONS OF THE PHX
METRO THAT MAY PASS OVER THE TERMINALS...BRIEFLY REDUCING CIGS BUT
NOT AMOUNTING TO MUCH BY WAY OF WETTING TARMAC/APRON SFCS. WESTERLY
WINDS 10KTS OR LESS WILL HOLD INTO THE OVERNIGHT HOURS...BEFORE
ATTEMPTING TO SWITCH TO EASTERLY NEAR OR AFTER 01/12Z...OTHERWISE
BECOME VARIABLE WITH SPEEDS 6 KTS OR LESS.
GIVEN THE COOLING AIRMASS AND ELEVATED DEWPOINTS...EXPECT ATLEAST
VCFG NEAR KIWA AND KSDL BY SUNRISE...WITH LESS CONFIDENCE OF ANY
SUBSTANTIAL FOG DEVELOPING NEAR KPHX.
SOUTHEAST CALIFORNIA AND SOUTHWEST ARIZONA INCLUDING KIPL AND KBLH...
PATCHES OF LOW TO MID LEVEL CIGS CONTINUE TO CIRCULATE AROUND THE
UPPER LOW THAT HAS NOW PUSHED INTO NW AZ. CIGS GNLY WILL HOLD ABOVE
8KFT FOR THE REMAINDER OF THE EVENING AS SOME DRIER AIR CONTINUES TO
WORK INTO THE REGION. WINDS TO HOLD NORTHERLY HEADINGS WHILE
SUBSIDING IN THEIR ELEVATED SPEEDS...OCCASIONALLY BECOMING NEAR CALM
AS SKIES CLEAR BY SUNRISE.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.FIRE WEATHER...
FRIDAY THROUGH TUESDAY...
MOSTLY CLEAR SKIES AND MUCH BELOW NORMAL TEMPERATURES ARE EXPECTED
FRIDAY THROUGH SUNDAY...WARMING SOMEWHAT MONDAY AND TUESDAY. MINIMUM
RELATIVE HUMIDITIES FRIDAY WILL RANGE FROM 20 PERCENT IN SOUTHEAST
CALIFORNIA TO 50 PERCENT IN SOUTHERN GILA COUNTY...DECREASING MONDAY
AND TUESDAY BY 15 TO 20 PERCENT RANGE AREA-WIDE. LIGHT WIND.
AVIATION DISCUSSION NOT UPDATED FOR AMENDED TAFS.
&&
.PSR WATCHES/WARNINGS/ADVISORIES...
AZ...FREEZE WARNING UNTIL 9 AM MST THIS MORNING AZZ020>022-026>028.
FREEZE WARNING FROM 11 PM THIS EVENING TO 9 AM MST FRIDAY
AZZ020>023-026>028.
WINTER STORM WARNING UNTIL 6 AM MST EARLY THIS MORNING ABOVE
3500 FEET FOR AZZ024.
CA...FREEZE WARNING UNTIL 8 AM PST THIS MORNING CAZ033.
FREEZE WARNING FROM 10 PM THIS EVENING TO 8 AM PST FRIDAY CAZ033.
&&
$$
VISIT US ON FACEBOOK...TWITTER...AND AT WEATHER.GOV/PHOENIX
DISCUSSION...HIRSCH
AVIATION....NOLTE
FIRE WEATHER...VASQUEZ
AREA FORECAST DISCUSSION
NWS TUCSON AZ
945 PM MST WED DEC 31 2014
.SYNOPSIS...RAIN AND SNOW WILL CONTINUE ACROSS MUCH OF THE AREA INTO
THURSDAY. SNOW LEVELS WILL FALL TO THE VALLEY FLOORS IN SOME
LOCATIONS TONIGHT. ELEVATIONS ABOVE 4000 FEET CAN EXPECT
ACCUMULATING SNOW BY THURSDAY MORNING WITH SIGNIFICANT SNOW IN THE
MOUNTAINS. A SECONDARY DISTURBANCE WILL BRING A FEW SNOW SHOWERS
THURSDAY NIGHT INTO FRIDAY MORNING. A HARD FREEZE IS LIKELY FOR THE
TUCSON METRO AREA THURSDAY NIGHT AND PERHAPS AGAIN FRIDAY NIGHT. DRY
CONDITIONS WITH A WARMING TREND WILL OCCUR THIS WEEKEND AND INTO
NEXT WEEK.
&&
.DISCUSSION...KEMX WSR-88D CONTINUES TO INDICATE NUMEROUS MAINLY
30-35 DBZ ECHOES ACROSS MUCH OF PIMA/SRN PINAL/SANTA CRUZ/FAR WRN
COCHISE COUNTY VALID 0440Z. THESE PRECIP ECHOES WERE MOVING NEWD
AROUND 10-15 KTS. BASED ON VARIOUS OBSERVATIONS...THE BEST ESTIMATE
FOR SNOW LEVELS IN THE FOOTHILLS ADJACENT TUCSON IS 3000-3500 FEET...
AND 4000-4500 FEET ACROSS ERN SANTA CRUZ COUNTY. THERE HAVE BEEN
SEVERAL REPORTS OF SNOW MIXED WITH RAIN ABOVE 3000 FEET VIA SOCIAL
MEDIA. MOUNT LEMMON FIRE DEPARTMENT (ELEV ABOUT 7800 FT) REPORTED A
SNOW ACCUMULATION OF 7.0 INCHES VALID 940 PM MST.
542 DM LOW CENTERED OVER FAR WEST CENTRAL AZ WILL MOVE NEWD INTO
NORTH CENTRAL AZ AROUND DAYBREAK THUR. PRECIP WILL CONTINUE TO MOVE
EWD THE REST OF TONIGHT...AND THE 01/01Z RUC HRRR DEPICTS THE BULK
OF PRECIP TO END FROM TUCSON WWD AROUND 01/08Z OR SO. HAVE NOTED
THAT THE HRRR DEPICTS PRECIP TO END ACROSS ERN SECTIONS SHORTLY
THEREAFTER...OR BY AROUND DAYBREAK THUR.
FOR THE OFFICIAL FORECAST UPDATE...SNOW LEVELS WERE LOWERED TO
REFLECT THE ONGOING CONDITIONS AS NOTED ABOVE. AREAS OF FOG WERE
ADDED FOR THE REST OF TONIGHT AND INTO THUR MORNING FOR ERN PIMA
COUNTY...SANTA CRUZ COUNTY AND THE UPPER SAN PEDRO RIVER VALLEY.
BASED ON RECEIPT OF THE 01/00Z NAM/GFS MOS GUIDANCE...OPTED TO
CHANGE THE FREEZE WATCH FOR THE TUCSON METRO AREA AND ADJOINING
LOCALES WEST-TO-NORTHWEST OF TUCSON TO A HARD FREEZE WARNING LATE
THUR NIGHT/EARLY FRI MORNING.
THE OTHER WINTER STORM WARNINGS...WINTER WEATHER ADVISORIES...AND
FREEZE WATCH CONTINUE UNCHANGED. PRECIP THUR AFTERNOON SHOULD BE
CONFINED TO ERN SECTIONS...AND ANY LINGERING SHOWERS SHOULD BE
MAINLY NEAR THE NEW MEXICO BORDER FRI.
PLEASE REFER TO THE ADDITIONAL SECTIONS FOR FURTHER DETAIL.
&&
.AVIATION...VALID THRU 02/06Z.
WIDESPREAD RAIN AND SNOW WILL OCCUR INTO THURSDAY MORNING...THEN
SCATTERED RAIN/SNOW SHOWERS WILL PREVAIL EAST OF KTUS THURSDAY
AFTERNOON AND THURSDAY EVENING. EXPECT WIDESPREAD MVFR CONDITIONS
INTO THURSDAY MORNING ALONG WITH OCCASIONAL IFR CONDITIONS. CLOUDS
WILL DECREASE WEST OF KTUS THURSDAY AFTERNOON FOLLOWED BY GRADUALLY
IMPROVING SKY CONDITIONS FURTHER EASTWARD TO INCLUDE KTUS THURSDAY
EVENING. SURFACE WIND EAST OF KTUS THE REST OF TONIGHT WILL BE SLY
TO WLY AT 12-20 KTS WITH GUSTS TO 30 KTS. THEREAFTER... SURFACE WIND
WILL BE MAINLY LESS THAN 10 KTS MOST SECTIONS THURSDAY AND THURSDAY
EVENING. AVIATION DISCUSSION NOT UPDATED FOR TAF AMENDMENTS.
&&
.FIRE WEATHER...EXPECT WIDESPREAD RAIN AND SNOW INTO THURSDAY AS A
WINTER STORM SYSTEM MOVES ACROSS THE AREA. A FEW LINGERING SHOWERS
WILL OCCUR EAST OF TUCSON THURSDAY NIGHT INTO FRIDAY. THEREAFTER...
DRY CONDITIONS WILL OCCUR THIS WEEKEND AND INTO NEXT WEEK.
&&
.PREV DISCUSSION...THE NEXT AREA OF CONCERN WILL BE SUB-FREEZING LOW
TEMPS FRIDAY AND SATURDAY MORNINGS...WHEN LOW TEMPS ARE EXPECTED TO
BE IN THE MID 20S TO NEAR 30 FOR MUCH OF THE TUCSON METRO AND INTO
CENTRAL PIMA COUNTY AND SOUTHEAST PINAL COUNTY. AFTER INSPECTION OF
12Z MOS LOW TEMP NUMBERS FOR FRIDAY AND SATURDAY MORNINGS...DECIDED
TO GO WITH A HARD FREEZE WATCH FOR SOUTHEAST PINAL COUNTY...CENTRAL
AND EASTERN PORTIONS OF PIMA COUNTY FRIDAY MORNING...THEN JUST FOR
EASTERN PORTIONS OF PIMA COUNTY AND EASTERN PINAL COUNTY FOR
SATURDAY MORNING SINCE THE LOWS WILL BE SLIGHTLY WARMER SATURDAY
MORNING COMPARED TO FRIDAY...AND AREAL COVERAGE OF TEMPS AT OR BELOW
27 DEGS F WILL BE SMALLER.
AS THE LOW BEGINS TO EJECT TO THE EAST LATE THURSDAY INTO FRIDAY...
LINGERING MOISTURE AND COLD AIR WILL JUSTIFY KEEPING A WINTER
WEATHER ADVISORY FOR THE MOUNTAINS OF GRAHAM AND GREENLEE COUNTIES
AND FOR THE SANTA CATALINA AND RINCON MOUNTAINS OF EASTERN PIMA
COUNTY THROUGH LATE THURSDAY AFTERNOON. THE LOW WILL BE FAR ENOUGH
TO OUR EAST BY LATE FRIDAY/EARLY SATURDAY TO RESULT IN A RETURN TO
DRY CONDITIONS THROUGH THE REMAINDER OF THE FORECAST PERIOD WITH A
WARMING TREND BEGINNING EARLY NEXT WEEK.
&&
.TWC WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL 11 AM MST THURSDAY FOR AZZ510-511-514.
WINTER STORM WARNING UNTIL 11 AM MST THURSDAY FOR AZZ506-509
ABOVE 4000 FEET.
WINTER WEATHER ADVISORY UNTIL 11 AM MST THURSDAY FOR AZZ512-513.
WINTER WEATHER ADVISORY FROM 11 AM TO 5 PM MST THURSDAY FOR
AZZ510-511-514.
HARD FREEZE WARNING FROM 3 AM TO 9 AM MST FRIDAY FOR AZZ502-
504>506.
FREEZE WATCH FROM LATE FRIDAY NIGHT THROUGH SATURDAY MORNING
FOR AZZ504-506.
&&
$$
VISIT US ON FACEBOOK...TWITTER...YOUTUBE...AND AT WEATHER.GOV/TUCSON
FRANCIS
PREV DISCUSSION...MOLLERE
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
320 PM MST THU JAN 1 2015
.SHORT TERM...(TONIGHT THROUGH FRIDAY NIGHT)
ISSUED AT 320 PM MST THU JAN 1 2015
THE HEAVIEST SNOWFALL OCCURRED LATE LAST NIGHT AND EARLY THIS
MORNING ACROSS THE FOUR CORNERS REGION AS PREDICTED. REPORTS
INDICATED 3 TO 5 INCHES OF SNOWFALL ACROSS MUCH OF THE REGION
WITH SNOWFALL RATES NEAR 1 INCH PER HOUR IN SOME LOCATIONS. UPWARD
FORCING IMPRESSIVE DURING THIS PERIOD AHEAD OF MID-LEVEL LOW
CENTERED OVER NORTH-CENTRAL ARIZONA. AT 12Z...GOOD SURFACE
CONVERGENCE IN EVIDENCE WITH SURFACE LOW CENTERED SOUTH OF KDRO
ACCORDING TO RAP ANALYSIS. CONCURRENTLY...STRONG MID-LEVEL QG
ASCENT OVER THE AREA TOPPED BY DIVERGENCE AT HIGHER LEVELS OF THE
TROPOSPHERE WHERE LEFT EXIT REGION OF JET WAS POSITIONED.
HOWEVER...DURING THE AFTERNOON COVERAGE AND SNOWFALL RATES HAD
DECREASED SIGNIFICANTLY AS FORCING WAS DIMINISHED. SOUTHWESTWARD
FLOWING JET ON THE BACK SIDE OF THE LOW CONTINUED TO PROPAGATE TO
THE SOUTHWEST WHILE THE NORTHEASTWARD FLOWING JET ON THE LEADING
EDGE MOVED OVER THE SOUTHERN PLAINS. THE SHEARING MOMENT BETWEEN
THESE FLOWS STRETCHED THE LOW ALONG A SOUTHWEST TO NORTHEAST AXIS.
AS A RESULT...DYNAMIC FORCING SHIFTED TO THE NORTHEAST CAUSING THE
SURFACE AND 7H LOW CIRCULATIONS TO MOVE IN THAT DIRECTION. IN
ADDITION TO THE LOSS OF DYNAMIC FORCING OVER THE SOUTHERN FORECAST
AREA...OROGRAPHIC LIFT ALSO IMPACTED AS WEAK 7H LOW RECENTERED
OVER THE SAN JUANS RESULTING IN WEAK AND VARIED WINDS.
MODELS IN GOOD AGREEMENT...GENERATING VERY LITTLE QPF OVER MOST OF
THE LOWER ELEVATIONS OF SOUTHEAST UTAH AND SOUTHWEST COLORADO
DURING THE REMAINDER OF THE AFTERNOON AND THIS EVENING. THEREFORE
...WILL CANCEL WINTER STORM WARNINGS FOR THESE AREAS WITH THIS
PACKAGE. HOWEVER...RAP13 AND HRRR BOTH INDICATED MODERATE SNOWFALL
WILL CONTINUE ALONG A SOUTHWEST TO NORTHEAST ORIENTED BAND
CENTERED OVER KCEZ. CONSEQUENTLY...WILL HOLD ONTO WINTER STORM
WARNING FOR MODERATE SNOWFALL OVER THE SOUTHWEST CORNER OF THE
STATE. IN ADDITION...LIGHT TO MODERATE SNOW SHOULD CONTINUE OVER
THE SAN JUAN MOUNTAINS WHILE COVERAGE INCREASES OVER THE CENTRAL
COLORADO MOUNTAINS AS DYNAMIC FORCING BECOMES MORE FAVORABLE. ONLY
EXPECTING 2 TO 4 INCHES WITH LOCALLY HIGHER AMOUNTS IN THE CENTRAL
MOUNTAINS SO WILL NOT EXPAND WINTER WEATHER ADVISORIES...THOUGH
WILL CONTINUE HILITES ACROSS THE SAN JUANS INTO THE EVENING.
SUBSIDENCE AND DRYING SETS IN LATER TONIGHT AS THE LOW CENTER IS
DRIVEN SOUTHWARD BY THE SOUTHWESTWARD PROPAGATING JET ON THE LOW/S
REAR FLANK. AS A RESULT...SNOWFALL WILL DIMINISH TO A FEW
FLURRIES OVER THE CENTRAL MOUNTAINS AFTER MIDNIGHT. ANTICYCLONIC
FLOW TO THE NORTH WILL INHIBIT SNOWFALL FRIDAY...THOUGH CANNOT
ENTIRELY RULE OUT A FEW FLURRIES ALONG THE DIVIDE FRIDAY
AFTERNOON. A SHORTWAVE TROUGH DROPPING TOWARD THE REGION FROM THE
NORTHWEST WILL BE THE NEXT SNOW PRODUCER OVER THE FORECAST AREA
POSSIBLY IMPACTING THE NORTHERN COLORADO MOUNTAINS FRIDAY NIGHT.
THE AREA WILL BE UNDER WARM AIR ADVECTION WHILE FLOW REMAINS
ANTICYCLONIC SO EXPECT SNOW WILL BE SCATTERED AND LIGHT...LIKELY
HOLDING OFF UNTIL AFTER MIDNIGHT AS INDICATED BY FAVORED GFS AND
ECMWF SOLUTIONS.
WAA WILL ALLOW AIRMASS TO MODERATE A BIT...BUT TEMPERATURES WILL
REMAIN COLDER THAN NORMAL FOR THE LATTER PART OF THE WEEK.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 320 PM MST THU JAN 1 2015
EXPECT SNOW WILL INCREASE OVER THE NORTHERN COLORADO MOUNTAINS
SATURDAY AS THE SHORTWAVE TROUGH DISCUSSED PREVIOUSLY PUSHES
ACROSS SOUTHWEST WYOMING IN THE MORNING...THEN ACROSS NORTHWEST
COLORADO DURING THE AFTERNOON. MODELS NOT GENERATING SIGNIFICANT
SNOW ACCUMULATIONS AT THIS POINT...BUT THERE REMAINS THE POTENTIAL
FOR ADVISORY LEVEL SNOW ACROSS THE PARK...GORE...ELKHEAD...AND
FLATTOP RANGES. A TIGHTENING GRADIENT ALOFT BENEATH THE NOSE OF A
SOUTHWARD FLOWING 120 KT JET WILL GENERATE STRONG AND GUSTY
NORTHWEST WINDS ACROSS THE RIDGES GENERATING AREAS OF BLOWING
SNOW.
MODELS INDICATED ANOTHER SHORTWAVE IN THE NORTHWESTERLIES WILL
BRING SIMILAR CONDITIONS SUNDAY AFTERNOON THROUGH SUNDAY NIGHT...
THOUGH IT APPEARS TO BE WEAKER THAN SATURDAY/S SYSTEM. HOWEVER...
ECMWF INDICATED THAT OROGRAPHIC SNOWFALL COULD CONTINUE WELL INTO
MONDAY SO MAY BE MORE IMPACTFUL THAN DEPICTED NOW. A RIDGE OF HIGH
PRESSURE EASES EASTWARD FROM TUESDAY TO THURSDAY BRINGING DRY AND
MILDER CONDITIONS FOR THE MIDDLE PART OF THE COMING WEEK.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z FRIDAY EVENING)
ISSUED AT 320 PM MST THU JAN 1 2015
WITH THE STORM CIRCULATION CENTER MOVING THROUGH NORTH-CENTRAL
THEN NORTHEAST NEW MEXICO TONIGHT AND THE JET RUNNING FURTHER
SOUTH AND EAST...MOST OF THE PRECIPITATION HAS SHIFTED TO THE
NORTHERN HEMISPHERE OF THE STORM. THE BEST ENHANCEMENT WILL BE
NORTH AND WEST OF A DISTURBANCE CIRCULATING OVER KCOS.
PRECIPITATION ENHANCED BY THAT DISTURBANCE WILL MOVE OVER KASE
THROUGH EARLY THIS EVENING...PROVIDING THE FURTHER DEGRADATION OF
FLIGHT CONDITIONS THERE. EXPECT MVFR CIGS AND VSBYS OVER KASE
UNTIL ABOUT 06Z AND INTERMITTENT IFR IN STRONGER SNOW SHOWERS
THROUGH ABOUT 02Z. KEGE...KRIL SHOULD SEE BRIEF MVFR CIGS AND
VSBYS THRU ABOUT 04Z AS SNOW SHOWERS ROTATE OVER THOSE LOCATIONS.
KGJT...KVEL AND ALL AIRPORTS NORTH OF I-70 SHOULD REMAIN VFR.
THE NORTHERN EDGE OF THE MAIN PRECIP BAND WILL EXTEND FROM KFNL
THEN SOUTHWEST TO KCNY. THE HEAVIEST PRECIP IN THE BAND SHOULD
EXTEND FROM KASE TO KMTJ TO ABOUT KBDG. MOUNTAINS AND HIGH PASSES
ACROSS CENTRAL CO AND SE UT WILL REMAIN OBSCURED TONIGHT AND BEGIN
OPENING UP AFTER SUNRISE. CONDITIONS WILL IMPROVE SIGNIFICANTLY
AFTER ABOUT 08Z TONIGHT.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ018.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR COZ021.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR COZ019.
UT...WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR UTZ028.
&&
$$
SHORT TERM...NL
LONG TERM...NL
AVIATION...CC
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1254 PM MST THU JAN 1 2015
.UPDATE...
ISSUED AT 1254 PM MST THU JAN 1 2015
BAND OF SNOW MOVING ACROSS THE PALMER DIVIDE IS PRODUCING A PERIOD
OF HEAVY SNOW. IT IS ALSO MAKING A FASTER NORTHWARD PROGRESSION.
AS A RESULT OF THE HEAVIER INTENSITY..SHOULD HAVE A BETTER CHANCE
OF MAKING IT INTO THE DENVER METRO AREA THIS AFTERNOON SO HAVE
BOOSTED POPS ACCORDINGLY.
UPDATE ISSUED AT 1012 AM MST THU JAN 1 2015
SATELLITE SHOWS THE MID LEVEL CLOUD DECK SPREADING INTO THE
SOUTHERN PORTIONS OF THE FORECAST AREA. RADAR ECHOES ARE RAPIDLY
INCREASING IN COVERAGE JUST TO THE SOUTH OF THE FORECAST
AREA IN SOUTHERN COLORADO...BUT MOST OF THIS IS VIRGA ON THE
PLAINS. MEANWHILE...MOUNTAIN LOCALES IN SOUTHERN COLORADO
ARE RECEIVING ACCUMULATING SNOWFALL. Q-G LIFT WILL INCREASE
THROUGH THE AFTERNOON UNDER THE LARGE SCALE DEFORMATION ZONE
SETTING UP ACROSS OUR FORECAST AREA. AS A RESULT...THE CLOUDS
WILL CONTINUE TO THICKEN AND LOWER WITH VIRGA BECOMING WIDESPREAD.
QUESTION STILL SURROUNDS HOW EFFICIENTLY THE SUBCLOUD LAYER WILL
MOISTEN ESPECIALLY SINCE THERE IS STILL SOME LOW LEVEL DOWNSLOPE
COMPONENT BELOW 700 MB. ABOVE THAT...FAIRLY STRONG EASTERLY
UPSLOPE COMPONENT AROUND 20 KNOTS ON AVERAGE. DUE TO THE DRIER LOW
LEVEL AIR...THE MAIN THREAT OF ACCUMULATING SNOW STILL RESIDES
FROM PARK/SUMMIT COUNTIES EASTWARD INTO DOUGLAS COUNTY AND THE
PALMER DIVIDE AREA LATER THIS AFTERNOON. HOWEVER...BY LATER THIS
EVENING THE BEST LIFT SHIFTS SLOWLY NORTHWARD SO BETTER CHANCE
COULD ACTUALLY MOVE SOMEWHAT NORTH. WILL HAVE TO WATCH THIS FOR
DUSTING TO 1 INCH OF SNOW POSSIBLE OVER THE DENVER METRO AREA
MAINLY BETWEEN 4 PM AND MIDNIGHT. ALL OF THIS HANDLED WELL IN
EXISTING FORECAST SO ONLY ADJUSTMENTS WERE TO INCREASE PARK COUNTY
POPS AS EVEN VALLEY LOCATIONS IN SOUTH PARK SHOULD PICK UP
MEASURABLE SNOWFALL THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 425 AM MST THU JAN 1 2015
A CLOSED MID-UPPER LOW OVER NORTH CENTRAL ARIZONA AT 09Z
WILL BECOME INCREASINGLY ELONGATED ACROSS COLORADO AS IT SHIFTS
EASTWARD ACROSS THE FOUR CORNERS REGION TODAY. AT THE SFC...AN
EXPANSIVE AREA OF HIGH PRESSURE LINKED TO AN ARCTIC AIRMASS COVERS
THE GREAT PLAINS. MODELS SHOW PRECIP FORMING NORTHEASTWARD ALONG THE
700-500MB TROUGH DEFORMATION AXIS REACHING THE SOUTHWEST CORNER OF
THE FORECAST AREA BY LATE THIS MORNING. FORWARD SPEED OF CLOUD
SHIELD WRAPPING AROUND THE UPPER LOW WILL LIKELY ARRIVE SOONER THAN
THAT BASED ON SPEED OF MOTION MEASUREMENTS USING IR SATELLITE
IMAGERY. EXCEPT FOR A BAND OF CIRRUS CLOUD STREAKING NEWRD ACRS THE
SOUTHEAST CORNER OF THE CWA...SKIES AT THE PRESENT TIME WERE CLEAR
ACROSS N-CENTRAL/NORTHEAST COLORADO. HRRR AND RAP MDLS SHOW LIGHT
SNOWFALL/QPF OVER THE MOSQUITO...TEN MILE AND SOUTHERN FRONT RANGE
MTNS BY MIDDAY...THEN SPREADING NORTHWARD OVER THE FRONT RANGE AND
EASTWARD ALONG THE PALMER DIVIDE AND SOUTHERN SECTIONS OF THE I-25
URBAN CORRIDOR DURING THE LATE AFTERNOON HOURS. FORECASTED PCPN AMTS
IN THIS AREA RANGE FROM A TRACE TO 0.20 INCH BY 00Z/FRI...AND SNOW
AMOUNTS FROM A TRACE TO 3 INCHES. THE HEAVIER AMTS WILL BE FOUND
OVER THE HIGHER TERRAIN SURROUNDING SOUTH PARK AND ALONG HIGHER
PORTIONS OF THE PALMER DIVIDE IN DOUGLAS COUNTY. BY EVENING WITH THE
UPPER LOW WEAKENING AND TURNING SOUTHEAST AWAY FROM COLORADO...
SHOULD SEE A MARKED DECREASE IN SNOWFALL ACROSS SOUTHERN SECTIONS OF
THE CWA BY MID TO LATE EVENING. AS THIS IS TAKING PLACE...MODELS
NAMELY THE NAM...SHOW A SECONDARY AREA OF SNOWFALL DEVELOPING OVER
THE NORTHERN FRONT RANGE MTN AND NRN I-25 URBAN CORRIDOR AS A RESULT
OF OROGRAPHIC LIFT AND COLD ADVECTION OCCURRING ON THE NORTHERN
FRINGE OF THE UPPER TROUGH. COULD SEE LOCAL SNOW AMTS UP TO AN INCH
OR SO OVER HIGHER ELEVATIONS OF THE NRN FRONT RANGE AND POSSIBLY A
QUARTER INCH OR SO ON THE NEARBY PLAINS BEFORE SKIES CLEAR AROUND
10Z/FRI.
HIGH TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGS COOLER THAN
YESTERDAY DUE IN LARGE PART TO THE LACK OF SUNSHINE THIS AFTERNOON.
WHEREAS TEMPS TONIGHT NOT AS COLD AS PREVIOUS NIGHTS BECAUSE OF
CLOUD COVER AND AS A RESULT OF MIXED BNDRY LAYER DUE TO PCPN IN
THE AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 425 AM MST THU JAN 1 2015
THE UPPER LOW NOW OVER ARIZONA WILL WEAKEN AND BECOME ELONGATED
ACROSS COLORADO EARLY FRIDAY MORNING. A PIECE OF THIS LOW
SEPARATES FROM THE PARENT SYSTEM WHICH WILL REMAIN OVER NEW
MEXICO THROUGH FRIDAY NIGHT. STILL EXPECT A FAIR AMOUNT OF
CLOUDINESS FRIDAY AM BUT ANY PRECIP WILL HAVE FINISHED DURING THE
EARLY MORNING HOURS. TEMPERATURES WILL STILL REMAIN IN THE 30S
ACROSS LOWER ELEVATIONS.
THE MAIN LOW OVER NEW MEXICO IS PROGGED TO LIFT NORTHEAST INTO THE
CENTRAL PLAINS ON SATURDAY WHILE A SECONDARY WAVE MOVES RAPIDLY
SOUTHEAST FROM THE NORTHERN ROCKIES. AN ACCOMPANIED COLD FRONT
EXPECTED TO BLAST ACROSS THE NORTHEAST PLAINS AROUND MIDDAY
SATURDAY WITH A BRIEF PERIOD OF UPSLOPE FLOW ON SATURDAY AFTERNOON
AND QUICK SHOT OF QG UPWARD FORCING AS STRONG JET MOVES ACROSS
COLORADO. WILL CONTINUE TO INCREASE POPS SLIGHTLY DURING THIS
PERIOD AS CONDITIONS CONTINUE TO LOOK MORE FAVORABLE FOR A SHOT OF
SNOW OVER MOUNTAINS AND PLAINS.
FOR SUNDAY AND INTO EARLY NEXT WEEK....THE PATTERN WILL SHIFT TO
A STRONG NORTHWEST FLOW ALOFT. THIS WILL RESULT IN INCREASING
WINDS OVER MOUNTAINS AND EAST SLOPES WITH A DOWNSLOPE WARMING
TREND OVER THE NORTHEAST PLAINS. GIVEN THE FLOW PATTERN EXPECT
SOME SNOW SHOWERS TO CONTINUE OVER THE HIGHER ELEVATIONS OF THE
NORTHERN MOUNTAINS BUT ONLY MINIMAL ACCUMULATIONS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1254 PM MST THU JAN 1 2015
CLOUDS WILL CONTINUE TO THICKEN AND LOWER THROUGH 21Z-03Z WITH
ILS LANDING CONDITIONS LIKELY WITH CEILINGS UNDER 5000-6000 FEET.
SHOULD ALSO SEE AREAS OF MVFR CEILINGS AND 3-4SM VISIBILITIES IN
LIGHT SNOW 21Z-07Z. LOCAL VISIBILITY AROUND 1SM WITH AROUND 1 INCH
ACCUMULATION POSSIBLE AT KAPA GIVEN INTENSITY OF SNOW BAND
MOVING UP FROM THE SOUTH. AFT 07Z...AREAS OF LIGHT SNOW AND LOWER
CEILINGS ARE EXPECTED TO DISSIPATE THRU 12Z AS AIRMASS GRADUALLY
DRIES AND UPPER LEVEL DISTURBANCE DEPARTS TO THE NORTHEAST. LIGHT
SOUTH/SOUTHWEST WINDS UNDER 7 KNOTS MAY BECOME LIGHT/VARIABLE
THROUGH THE EARLY EVENING BEFORE SETTLING TO A SOUTHWEST/WEST
AROUND 5-8 KNOTS OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...BAKER
LONG TERM...ENTREKIN
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1012 AM MST THU JAN 1 2015
.UPDATE...
ISSUED AT 1012 AM MST THU JAN 1 2015
SATELLITE SHOWS THE MID LEVEL CLOUD DECK SPREADING INTO THE
SOUTHERN PORTIONS OF THE FORECAST AREA. RADAR ECHOES ARE RAPIDLY
INCREASING IN COVERAGE JUST TO THE SOUTH OF THE FORECAST
AREA IN SOUTHERN COLORADO...BUT MOST OF THIS IS VIRGA ON THE
PLAINS. MEANWHILE...MOUNTAIN LOCALES IN SOUTHERN COLORADO
ARE RECEIVING ACCUMULATING SNOWFALL. Q-G LIFT WILL INCREASE
THROUGH THE AFTERNOON UNDER THE LARGE SCALE DEFORMATION ZONE
SETTING UP ACROSS OUR FORECAST AREA. AS A RESULT...THE CLOUDS
WILL CONTINUE TO THICKEN AND LOWER WITH VIRGA BECOMING WIDESPREAD.
QUESTION STILL SURROUNDS HOW EFFICIENTLY THE SUBCLOUD LAYER WILL
MOISTEN ESPECIALLY SINCE THERE IS STILL SOME LOW LEVEL DOWNSLOPE
COMPONENT BELOW 700 MB. ABOVE THAT...FAIRLY STRONG EASTERLY
UPSLOPE COMPONENT AROUND 20 KNOTS ON AVERAGE. DUE TO THE DRIER LOW
LEVEL AIR...THE MAIN THREAT OF ACCUMULATING SNOW STILL RESIDES
FROM PARK/SUMMIT COUNTIES EASTWARD INTO DOUGLAS COUNTY AND THE
PALMER DIVIDE AREA LATER THIS AFTERNOON. HOWEVER...BY LATER THIS
EVENING THE BEST LIFT SHIFTS SLOWLY NORTHWARD SO BETTER CHANCE
COULD ACTUALLY MOVE SOMEWHAT NORTH. WILL HAVE TO WATCH THIS FOR
DUSTING TO 1 INCH OF SNOW POSSIBLE OVER THE DENVER METRO AREA
MAINLY BETWEEN 4 PM AND MIDNIGHT. ALL OF THIS HANDLED WELL IN
EXISTING FORECAST SO ONLY ADJUSTMENTS WERE TO INCREASE PARK COUNTY
POPS AS EVEN VALLEY LOCATIONS IN SOUTH PARK SHOULD PICK UP
MEASURABLE SNOWFALL THIS AFTERNOON.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 425 AM MST THU JAN 1 2015
A CLOSED MID-UPPER LOW OVER NORTH CENTRAL ARIZONA AT 09Z
WILL BECOME INCREASINGLY ELONGATED ACROSS COLORADO AS IT SHIFTS
EASTWARD ACROSS THE FOUR CORNERS REGION TODAY. AT THE SFC...AN
EXPANSIVE AREA OF HIGH PRESSURE LINKED TO AN ARCTIC AIRMASS COVERS
THE GREAT PLAINS. MODELS SHOW PRECIP FORMING NORTHEASTWARD ALONG THE
700-500MB TROUGH DEFORMATION AXIS REACHING THE SOUTHWEST CORNER OF
THE FORECAST AREA BY LATE THIS MORNING. FORWARD SPEED OF CLOUD
SHIELD WRAPPING AROUND THE UPPER LOW WILL LIKELY ARRIVE SOONER THAN
THAT BASED ON SPEED OF MOTION MEASUREMENTS USING IR SATELLITE
IMAGERY. EXCEPT FOR A BAND OF CIRRUS CLOUD STREAKING NEWRD ACRS THE
SOUTHEAST CORNER OF THE CWA...SKIES AT THE PRESENT TIME WERE CLEAR
ACROSS N-CENTRAL/NORTHEAST COLORADO. HRRR AND RAP MDLS SHOW LIGHT
SNOWFALL/QPF OVER THE MOSQUITO...TEN MILE AND SOUTHERN FRONT RANGE
MTNS BY MIDDAY...THEN SPREADING NORTHWARD OVER THE FRONT RANGE AND
EASTWARD ALONG THE PALMER DIVIDE AND SOUTHERN SECTIONS OF THE I-25
URBAN CORRIDOR DURING THE LATE AFTERNOON HOURS. FORECASTED PCPN AMTS
IN THIS AREA RANGE FROM A TRACE TO 0.20 INCH BY 00Z/FRI...AND SNOW
AMOUNTS FROM A TRACE TO 3 INCHES. THE HEAVIER AMTS WILL BE FOUND
OVER THE HIGHER TERRAIN SURROUNDING SOUTH PARK AND ALONG HIGHER
PORTIONS OF THE PALMER DIVIDE IN DOUGLAS COUNTY. BY EVENING WITH THE
UPPER LOW WEAKENING AND TURNING SOUTHEAST AWAY FROM COLORADO...
SHOULD SEE A MARKED DECREASE IN SNOWFALL ACROSS SOUTHERN SECTIONS OF
THE CWA BY MID TO LATE EVENING. AS THIS IS TAKING PLACE...MODELS
NAMELY THE NAM...SHOW A SECONDARY AREA OF SNOWFALL DEVELOPING OVER
THE NORTHERN FRONT RANGE MTN AND NRN I-25 URBAN CORRIDOR AS A RESULT
OF OROGRAPHIC LIFT AND COLD ADVECTION OCCURRING ON THE NORTHERN
FRINGE OF THE UPPER TROUGH. COULD SEE LOCAL SNOW AMTS UP TO AN INCH
OR SO OVER HIGHER ELEVATIONS OF THE NRN FRONT RANGE AND POSSIBLY A
QUARTER INCH OR SO ON THE NEARBY PLAINS BEFORE SKIES CLEAR AROUND
10Z/FRI.
HIGH TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGS COOLER THAN
YESTERDAY DUE IN LARGE PART TO THE LACK OF SUNSHINE THIS AFTERNOON.
WHEREAS TEMPS TONIGHT NOT AS COLD AS PREVIOUS NIGHTS BECAUSE OF
CLOUD COVER AND AS A RESULT OF MIXED BNDRY LAYER DUE TO PCPN IN
THE AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 425 AM MST THU JAN 1 2015
THE UPPER LOW NOW OVER ARIZONA WILL WEAKEN AND BECOME ELONGATED
ACROSS COLORADO EARLY FRIDAY MORNING. A PIECE OF THIS LOW
SEPARATES FROM THE PARENT SYSTEM WHICH WILL REMAIN OVER NEW
MEXICO THROUGH FRIDAY NIGHT. STILL EXPECT A FAIR AMOUNT OF
CLOUDINESS FRIDAY AM BUT ANY PRECIP WILL HAVE FINISHED DURING THE
EARLY MORNING HOURS. TEMPERATURES WILL STILL REMAIN IN THE 30S
ACROSS LOWER ELEVATIONS.
THE MAIN LOW OVER NEW MEXICO IS PROGGED TO LIFT NORTHEAST INTO THE
CENTRAL PLAINS ON SATURDAY WHILE A SECONDARY WAVE MOVES RAPIDLY
SOUTHEAST FROM THE NORTHERN ROCKIES. AN ACCOMPANIED COLD FRONT
EXPECTED TO BLAST ACROSS THE NORTHEAST PLAINS AROUND MIDDAY
SATURDAY WITH A BRIEF PERIOD OF UPSLOPE FLOW ON SATURDAY AFTERNOON
AND QUICK SHOT OF QG UPWARD FORCING AS STRONG JET MOVES ACROSS
COLORADO. WILL CONTINUE TO INCREASE POPS SLIGHTLY DURING THIS
PERIOD AS CONDITIONS CONTINUE TO LOOK MORE FAVORABLE FOR A SHOT OF
SNOW OVER MOUNTAINS AND PLAINS.
FOR SUNDAY AND INTO EARLY NEXT WEEK....THE PATTERN WILL SHIFT TO
A STRONG NORTHWEST FLOW ALOFT. THIS WILL RESULT IN INCREASING
WINDS OVER MOUNTAINS AND EAST SLOPES WITH A DOWNSLOPE WARMING
TREND OVER THE NORTHEAST PLAINS. GIVEN THE FLOW PATTERN EXPECT
SOME SNOW SHOWERS TO CONTINUE OVER THE HIGHER ELEVATIONS OF THE
NORTHERN MOUNTAINS BUT ONLY MINIMAL ACCUMULATIONS.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z FRIDAY MORNING)
ISSUED AT 1012 AM MST THU JAN 1 2015
CLOUDS WILL CONTINUE TO THICKEN AND LOWER THROUGH 22Z-03Z WITH
ILS LANDING CONDITIONS LIKELY WITH CEILINGS UNDER 5000-6000 FEET.
SHOULD ALSO SEE POCKETS OF MVFR CEILINGS AND 3-4SM VISIBILITIES IN
LIGHT SNOW 22Z-07Z. AFT 07Z...AREAS OF LIGHT SNOW AND LOWER
CEILINGS ARE EXPECTED TO DISSIPATE THRU 12Z AS AIRMASS GRADUALLY
DRIES AND UPPER LEVEL DISTURBANCE DEPARTS TO THE NORTHEAST. LIGHT
SOUTH/SOUTHWEST WINDS UNDER 7 KNOTS MAY BECOME LIGHT/VARIABLE
THROUGH THE EARLY EVENING BEFORE SETTLING TO A SOUTHWEST/WEST
AROUND 5-8 KNOTS OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...BARJENBRUCH
SHORT TERM...BAKER
LONG TERM...ENTREKIN
AVIATION...BARJENBRUCH
AREA FORECAST DISCUSSION
NWS GRAND JUNCTION CO
502 AM MST THU JAN 1 2015
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 406 AM MST THU JAN 1 2015
SATELLITE AND RADAR SIGNATURES FINALLY SHOWING SOME PROMISE ACROSS
OUR SOUTHWEST CWA EARLY THIS MORNING. THIS IS A LATER START THAN
EXPECTED. SNOW TOTALS ARE LIKELY GOING TO BE LESS THAN EARLIER
THOUGHT...BUT LOOKING AT BLANDING WEB CAM...THIS STORM IS LIKELY
TO IMPACT TRAVEL ON THIS HOLIDAY OVER A GOOD CHUNK OF OUR CWA. THE
NEXT 6 TO 12 HOURS WILL BE THE MOST ACTIVE PERIOD ACROSS OUR CWA
AND WILL LET THE CURRENT HIGHLIGHTS RUN.
LARGE SCALE ASCENT IS INCREASING SIGNIFICANTLY OVER THE 4 CORNERS AS
THE UPPER JET MAX IS FINALLY REFORMING ON THE DOWNSTREAM SIDE OF THE
CYCLONE AND ALLOWING IT TO SLOG EASTWARD. THE CYCLONIC JET IS AIDING
IN THE STRONG UPWARD MOTION AND AN INVERTED TROF EXTENDING FROM THE
4 CORNERS TO THE CENTRAL MOUNTAINS IS AIDING IN LOW LEVEL
CONVERGENCE OVER SOUTHEAST UTAH AND SOUTHWESTERN COLORADO THIS
MORNING. QG FIELDS SUGGEST THE ASCENT INCREASES AND TIGHTENS THROUGH
MID MORNING NEAR THE 4 CORNERS...THEN RELAXES THROUGH THE DAY AS MID
LEVEL CIRCULATION IS ELONGATED BY THE RETREATING JET MAX. SOUTHERLY
OROGRAPHICS ARE LIKELY TO AID IN FOCUSING HEAVIER SNOW IN THE
FOOTHILLS AND HILLS OF THE SOUTHERN SAN JUANS WITH THE LOW JUST TO
THE WEST THIS MORNING. UNFORTUNATELY INSTABILITY WILL NOT BE AS
STRONG AS ANTICIPATED 24 HOURS AGO. BOTH MODELS SHOW BOTH A MID
LEVEL AND LOW LEVEL CIRCULATION RUNNING ALONG THE INVERTED TROUGH
AXIS AND THIS SHOULD BRING SNOW ACROSS THE CENTRAL MOUNTAINS AND
VALLEYS THROUGH THE EARLY EVENING...THOUGH OROGRAPHICS SLACKEN LATER
TODAY. DID BOOST POPS AND SNOW AMOUNTS ACROSS THE WEST ELKS...ELKS
AND TOP OF THE MESA. LOOKING AT THE LATEST BUFKIT SOUNDING DATA AND
SREF PLUMES ALSO THINK SOME HIGH VALLEY LOCATIONS MAY PICK UP SOME
SNOW THIS AFTERNOON. THIS INCLUDES ASPEN WHICH IS NEAR THE PASSING
SURFACE LOW AND GUNNISON WHERE AMOUNTS WILL GENERALLY BE 2-3 INCHES.
DECIDED AGAINST AN ADVISORY AT THIS TIME WITH THE HIGH PASSES
CLOSED...THE ONLY CONCERN WOULD BE AT MCCLURE BUT CONFIDENCE TOO LOW
ATTM. THE LOW CONTINUES TO ELONGATE TONIGHT WITH THE GFS AND NAM NOW
TAKING DIFFERENT CAMPS ON WHERE THE MAIN CIRCULATIONS REMAIN IN THIS
AREA OF LOW PRESSURE. GFS DEVELOPS ONE SOUTHERN UTAH AND THE NAM THE
PLAINS OF COLORADO. EITHER WAY AN EASTERLY COMPONENT TO THE WINDS
OCCUR WHICH MAY KEEP SOME ISOLATED SHOWERS GOING WITH RESIDUAL
MOISTURE AROUND FOR THE MOST PART THIS STORM IS DONE BY MIDNIGHT.
THE DENDRITIC LAYER DRIES OUT IN THE FAVORED GFS SOLUTION AND THIS
LEAD TO A QUIET BUT COLD FRIDAY AND NEW SNOW HOLDS THE INVERSION IN.
TEMPERATURES REMAIN COLD AND WELL BELOW NORMAL.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 406 AM MST THU JAN 1 2015
THE NEXT PROGRESSIVE SHORT WAVE ARRIVES FROM THE NORTHWEST WITH
INCREASING CLOUDS ACROSS THE NORTH ON FRIDAY NIGHT. THE BEST
DYNAMICAL FORCING ARRIVES SATURDAY...COINCIDING WITH SOME MID
LEVEL COLD ADVECTION. THE NORTHERN COLORADO MOUNTAINS WILL BE THE
PRIMARY BENEFICIARY FOR SNOW...BUT COULD EXTEND AS FAR SOUTH AS
THE NWRN SAN JUAN MOUNTAINS. MODEL QPF AMOUNTS SUGGEST SNOW
AMOUNTS MOSTLY IN THE 5-10 INCH RANGE FOR THE NWRN COLORADO
MOUNTAINS. A LITTLE CONCERN THAT THE TRAPPED COLD AIR AND SNOW TO
LIQUID RATIOS OF 20:1 OR HIGHER COULD ENHANCE SNOW AMOUNTS. ABOVE
TIMBERLINE OR EXPOSED AREAS WILL BE PRONE FOR BLOWING SNOW AS
700 MB GRADIENT FLOW WILL BE AROUND 30 KTS. WITH THE MODERATELY
DEEP SURFACE LOW TRACKING WELL NORTH OF COLORADO (ACROSS MONTANA
AND THE DAKOTAS)...THIS REDUCES THE LIKELIHOOD OF SIGNIFICANT
HEAVY SNOW (MEANING 12+ INCHES) FOR NORTHWEST COLORADO. THE SNOW
THREAT DECREASES FARTHER WEST AND SOUTH.
PACIFIC MOISTURE CONTINUES TO STREAM OVER THE NRN COLORADO
MOUNTAINS FOR SOME OROGRAPHIC SNOWFALL INTO MONDAY. THIS MOISTURE
FEED IS NOT DEEP WITH SPOTTY LIGHT AMOUNTS FOR NORTHERN ROUTT
COUNTY.
THE PASSAGE OF SATURDAYS SHORT WAVE IS STRONG ENOUGH TO CAUSE SOME
MIXING AND WEAKEN TEMPERATURE INVERSIONS. A WARMING TREND SHOULD
PERSIST INTO NEXT WEDNESDAY. THE RATE OF WARMING TENDS TO BE
PROBLEMATIC SINCE MANY VALLEYS ARE SNOW COVERED...BUT THE PATTERN
DOES NOT FAVOR A STAGNANT AIR MASS WITH WNW FLOW PREVAILING OVER
THE FORECAST AREA (WITH THE MAIN JET NORTH OF COLORADO). THE
RIDGE AXIS WILL BE POSITIONED OVER THE WEST COAST STATES AND NOT
OVERHEAD...SO THIS SHOULD RESULT IN SOME TEMPERATURE MODERATION.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 502 AM MST THU JAN 1 2015
WIDESPREAD -SN (OR OCCASIONAL MODERATE SNOW) WITH IFR CIGS ACROSS
ACROSS SERN UTAH AND SWRN COLORADO TODAY. THE I70 CORRIDOR OR
KGJT...KRIL...KASE...KEGE WILL BE ON THE NRN FRINGE OF THIS REGION
OF SNOW. CURRENT HRRR MODEL KEEPS LIGHT SNOW FROM IMPACTING THESE
TAF SITES WITH THE EXCEPTION OF KASE. KASE MAY TEMPORARILY FALL
BELOW ILS BREAKPOINTS THIS AFTERNOON AND INTO THE EVENING HOURS.
SLOW IMPROVEMENT AFTER 00Z WITH LIGHT TO MODERATE SNOW DECREASING
ACROSS SW COLORADO.
VFR IS EXPECTED TO PREVAIL NORTH OF INTERSTATE 70.
&&
.GJT WATCHES/WARNINGS/ADVISORIES...
CO...WINTER WEATHER ADVISORY UNTIL MIDNIGHT MST TONIGHT FOR COZ018-
020.
WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR COZ019-
021>023.
UT...WINTER STORM WARNING UNTIL MIDNIGHT MST TONIGHT FOR UTZ028.
WINTER STORM WARNING UNTIL 6 PM MST THIS EVENING FOR UTZ022-029.
&&
$$
SHORT TERM...15
LONG TERM...PF
AVIATION...PF
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
426 AM MST THU JAN 1 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 425 AM MST THU JAN 1 2015
A CLOSED MID-UPPER LOW OVER NORTH CENTRAL ARIZONA AT 09Z
WILL BECOME INCREASINGLY ELONGATED ACROSS COLORADO AS IT SHIFTS
EASTWARD ACROSS THE FOUR CORNERS REGION TODAY. AT THE SFC...AN
EXPANSIVE AREA OF HIGH PRESSURE LINKED TO AN ARCTIC AIRMASS COVERS
THE GREAT PLAINS. MODELS SHOW PRECIP FORMING NORTHEASTWARD ALONG THE
700-500MB TROUGH DEFORMATION AXIS REACHING THE SOUTHWEST CORNER OF
THE FORECAST AREA BY LATE THIS MORNING. FORWARD SPEED OF CLOUD
SHIELD WRAPPING AROUND THE UPPER LOW WILL LIKELY ARRIVE SOONER THAN
THAT BASED ON SPEED OF MOTION MEASUREMENTS USING IR SATELLITE
IMAGERY. EXCEPT FOR A BAND OF CIRRUS CLOUD STREAKING NEWRD ACRS THE
SOUTHEAST CORNER OF THE CWA...SKIES AT THE PRESENT TIME WERE CLEAR
ACROSS N-CENTRAL/NORTHEAST COLORADO. HRRR AND RAP MDLS SHOW LIGHT
SNOWFALL/QPF OVER THE MOSQUITO...TEN MILE AND SOUTHERN FRONT RANGE
MTNS BY MIDDAY...THEN SPREADING NORTHWARD OVER THE FRONT RANGE AND
EASTWARD ALONG THE PALMER DIVIDE AND SOUTHERN SECTIONS OF THE I-25
URBAN CORRIDOR DURING THE LATE AFTERNOON HOURS. FORECASTED PCPN AMTS
IN THIS AREA RANGE FROM A TRACE TO 0.20 INCH BY 00Z/FRI...AND SNOW
AMOUNTS FROM A TRACE TO 3 INCHES. THE HEAVIER AMTS WILL BE FOUND
OVER THE HIGHER TERRAIN SURROUNDING SOUTH PARK AND ALONG HIGHER
PORTIONS OF THE PALMER DIVIDE IN DOUGLAS COUNTY. BY EVENING WITH THE
UPPER LOW WEAKENING AND TURNING SOUTHEAST AWAY FROM COLORADO...
SHOULD SEE A MARKED DECREASE IN SNOWFALL ACROSS SOUTHERN SECTIONS OF
THE CWA BY MID TO LATE EVENING. AS THIS IS TAKING PLACE...MODELS
NAMELY THE NAM...SHOW A SECONDARY AREA OF SNOWFALL DEVELOPING OVER
THE NORTHERN FRONT RANGE MTN AND NRN I-25 URBAN CORRIDOR AS A RESULT
OF OROGRAPHIC LIFT AND COLD ADVECTION OCCURRING ON THE NORTHERN
FRINGE OF THE UPPER TROUGH. COULD SEE LOCAL SNOW AMTS UP TO AN INCH
OR SO OVER HIGHER ELEVATIONS OF THE NRN FRONT RANGE AND POSSIBLY A
QUARTER INCH OR SO ON THE NEARBY PLAINS BEFORE SKIES CLEAR AROUND
10Z/FRI.
HIGH TEMPERATURES TODAY ARE EXPECTED TO BE A FEW DEGS COOLER THAN
YESTERDAY DUE IN LARGE PART TO THE LACK OF SUNSHINE THIS AFTERNOON.
WHEREAS TEMPS TONIGHT NOT AS COLD AS PREVIOUS NIGHTS BECAUSE OF
CLOUD COVER AND AS A RESULT OF MIXED BNDRY LAYER DUE TO PCPN IN
THE AREA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 425 AM MST THU JAN 1 2015
THE UPPER LOW NOW OVER ARIZONA WILL WEAKEN AND BECOME ELONGATED
ACROSS COLORADO EARLY FRIDAY MORNING. A PIECE OF THIS LOW
SEPARATES FROM THE PARENT SYSTEM WHICH WILL REMAIN OVER NEW
MEXICO THROUGH FRIDAY NIGHT. STILL EXPECT A FAIR AMOUNT OF
CLOUDINESS FRIDAY AM BUT ANY PRECIP WILL HAVE FINISHED DURING THE
EARLY MORNING HOURS. TEMPERATURES WILL STILL REMAIN IN THE 30S
ACROSS LOWER ELEVATIONS.
THE MAIN LOW OVER NEW MEXICO IS PROGGED TO LIFT NORTHEAST INTO THE
CENTRAL PLAINS ON SATURDAY WHILE A SECONDARY WAVE MOVES RAPIDLY
SOUTHEAST FROM THE NORTHERN ROCKIES. AN ACCOMPANIED COLD FRONT
EXPECTED TO BLAST ACROSS THE NORTHEAST PLAINS AROUND MIDDAY
SATURDAY WITH A BRIEF PERIOD OF UPSLOPE FLOW ON SATURDAY AFTERNOON
AND QUICK SHOT OF QG UPWARD FORCING AS STRONG JET MOVES ACROSS
COLORADO. WILL CONTINUE TO INCREASE POPS SLIGHTLY DURING THIS
PERIOD AS CONDITIONS CONTINUE TO LOOK MORE FAVORABLE FOR A SHOT OF
SNOW OVER MOUNTAINS AND PLAINS.
FOR SUNDAY AND INTO EARLY NEXT WEEK....THE PATTERN WILL SHIFT TO
A STRONG NORTHWEST FLOW ALOFT. THIS WILL RESULT IN INCREASING
WINDS OVER MOUNTAINS AND EAST SLOPES WITH A DOWNSLOPE WARMING
TREND OVER THE NORTHEAST PLAINS. GIVEN THE FLOW PATTERN EXPECT
SOME SNOW SHOWERS TO CONTINUE OVER THE HIGHER ELEVATIONS OF THE
NORTHERN MOUNTAINS BUT ONLY MINIMAL ACCUMULATIONS.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 425 AM MST THU JAN 1 2015
VFR CONDITIONS AT DENVER AREA TERMINALS THIS MORNING WILL
DETERIORATE TO MVFR CONDITIONS WITH LOWERING CIGS TO AROUND
4000-5000 FT AGL AND SCATTERED AREAS OF LIGHT SNOWFALL REDUCING
VSBYS TO 3-5 MILES AFTER 4 PM MST. KAPA COULD POSSIBLY SEE ILS
CONDITIONS WITH CIGS LOWERING TO BELOW 3000 FEET AGL AND VSBYS
BELOW 3 MILES WITH LIGHT TO MODERATE SNOWFALL LATE THIS AFTERNOON
AND EARLY THIS EVENING. CONDITIONS SHOULD IMPROVE AT ALL
TERMINALS AFTER 04Z THIS EVENING WITH CLEARING SKIES BEFORE
MORNING. LIGHT S-SWLY WINDS EARLY TO MID-MORNING EXPECTED TO
BECOME W-NWLY BY LATE MORNING BEFORE RETURNING TO A S-SWLY
DIRECTION THIS EVENING. MOST AREAS SHOULD SEE WIND SPEEDS
REMAINING UNDER 12 KTS.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...BAKER
LONG TERM...ENTREKIN
AVIATION...BAKER
AREA FORECAST DISCUSSION
NWS MIAMI FL
124 PM EST THU JAN 1 2015
.AVIATION...
LINGERING STATIONARY FRONT ACROSS THE AREA IS EXPECTED TO PUSH TO
THE NORTH AS A WARM FRONT THROUGH THE NIGHT. THIS WILL LEAVE AMPLE
LOW LEVEL MOISTURE AND THE THREAT OF FOG/LOW CIGS MAINLY ACROSS
THE GULF COAST OVERNIGHT AND INTO EARLY FRIDAY MORNING. UNDERCUT
LAMP GUIDANCE AGAIN FOR KAPF THROUGH THE NIGHT PREVAILING MVFR
CIGS WITH TEMPO IFR CIGS AND VSBY. BELIEVE THAT THE EAST COAST
SITES SHOULD REMAIN VFR WITH BRIEF MVFR CIGS POSSIBLE BUT NOT
CONFIDENT ENOUGH TO MENTION IN TAFS ATTM.
&&
.PREV DISCUSSION... /ISSUED 1004 AM EST THU JAN 1 2015/
UPDATE...
SCATTERED SHOWERS REMAIN THIS MORNING MAINLY ACROSS THE ATLANTIC
WATERS OFF THE PALM BEACHES. WEAK STATIONARY FRONT REMAINS DRAPED
ACROSS THE AREA THIS MORNING CONTRIBUTING TO THE SHOWERS AND
EXTENSIVE CLOUDINESS. LATEST VISIBLE SATELLITE DOES HOWEVER SHOW
CLOUD SHIELD BEGINNING TO ERODE ACROSS BROWARD AND MIAMI-DADE
COUNTIES LATE THIS MORNING. THIS HAS ALLOWED TEMPERATURES TO SURGE
INTO THE MID TO UPPER 70S ALREADY. HRRR CONTINUES TO DEPICT
ISOLATED LIGHT SHOWERS ACROSS MAINLY THE EASTERN HALF OF THE AREA
INTO THE EARLY AFTERNOON HOURS...SO KEPT SLIGHT CHANCE POP GOING.
THE REMAINDER OF THE FORECAST LOOKS ON TRACK AT THIS TIME. UPDATE
SENT.
PREV DISCUSSION... /ISSUED 319 AM EST THU JAN 1 2015/
DISCUSSION...
A COMPACT AND WEAK MESOSCALE LOW PASSED SOUTHWARD ACROSS THE
ATLANTIC WATERS YESTERDAY ALONG PALM BEACH COUNTY THEN DRIFTED
WESTWARD ACROSS THE SOUTH FLORIDA PENINSULA EARLY THIS MORNING.
DURING THE EARLY MORNING HOURS SCATTERED SHOWER ACTIVITY OCCURRED
WITH THE GREATEST COVERAGE ACROSS NORTHERN BROWARD COUNTY AND
ACROSS PALM BEACH COUNTY AND ADJACENT ATLANTIC WATERS...WITH THIS
COVERAGE CONTINUING.
THE COMBINATION OF LOW STRATUS AND/OR FOG WILL CONTINUE EARLY THIS
MORNING WITH MOST OF THE COVERAGE EXPECTED ACROSS MIAMI DADE
COUNTY AND SOUTHERN HALF OF BROWARD COUNTY.
THE WILL BE A CHANCE OF RIP CURRENTS TODAY BUT MAINLY EXPECTED
ACROSS THE PALM BEACH COUNTY BEACHES.
THE LATEST MODEL GUIDANCE INDICATES A WEAK SURFACE TROUGH AND
DIFFUSE FRONTAL BOUNDARY CONTINUING ACROSS THE SOUTH FLORIDA
PENINSULA TODAY WITH HIGH PRESSURE THEN STARTING TO BUILD BACK
ACROSS THE REGION THIS EVENING AND OVER NIGHT. THE FORECAST FOR
TODAY IS FOR ISOLATED TO SCATTERED SHOWERS MAINLY ACROSS THE
ATLANTIC WATERS AND THE ATLANTIC METRO AREAS WITH THE GREATEST
COVERAGE CONTINUING TO BE ACROSS BROWARD AND PALM BEACH COUNTIES
AND THE ADJACENT ATLANTIC WATERS. A DRYING TREND IS THEN FORECAST
WITH THE MODEL CONSENSUS INDICATING SOUTHERLY LOW LEVEL FLOW
BRINGING IN DRIER AIR INTO THE REGION TONIGHT INTO FRIDAY. BY
FRIDAY HIGH PRESSURE WILL PREVAIL ACROSS THE REGION WITH A SURFACE
RIDGE EAST OF THE FLORIDA PENINSULA AND AT THE MID TO UPPER LEVELS
A LARGE AMPLITUDE RIDGE BECOMING ESTABLISHED ACROSS THE FLORIDA
STRAITS. THIS PATTERN WILL MORE OR LESS PERSIST THROUGH THE
UPCOMING WEEKEND...WITH STABLE WEATHER CONDITIONS AND INCREASINGLY
WARMER TEMPERATURES PREVAILING ACROSS THE REGION.
FOR THE EXTENDED FORECAST...THE GLOBAL MODEL CONSENSUS INDICATES
THE NEXT COLD FRONT ENTERING THE FLORIDA PANHANDLE AND NORTHERN
FLORIDA ON SUNDAY AND THEN INTO CENTRAL FLORIDA ON MONDAY AND APPROACHING
LAKE OKEECHOBEE AND WEAKENING MONDAY NIGHT. BY TUESDAY THE MODELS
START TO DIVERGE IN THEIR SOLUTIONS...BUT OVER ALL NO SIGNIFICANT
IMPACTS ARE FORECAST THUS FAR FOR SOUTH FLORIDA WITH THE FORECAST
INDICATING JUST A GRADUAL COOL DOWN AND POSSIBLY SOME ISOLATED
SHOWER ACTIVITY. /BD
MARINE...
THE LOCAL PRESSURE GRADIENT ACROSS THE REGION EARLY THIS MORNING
IS SUCH THAT WINDS IN THE 15 TO 20 KNOT RANGE ARE FORECAST ACROSS
THE ATLANTIC WATERS MAINLY TO THE EAST OF PALM BEACH COUNTY AND
ACROSS THE OFF SHORE WATERS...WITH AN SCEC FOR THESE WATERS TODAY.
THE PRESSURE GRADIENT AND RESULTANT WINDS EAST OF PALM BEACH
COUNTY IS FORECAST TO RELAX TONIGHT INTO FRIDAY. FOR THE REMAINDER
OF THE OF THE FORECAST...WINDS AND SEAS ACROSS THE GULF AND
ATLANTIC WATERS ARE FORECAST TO REMAIN WELL BELOW ADVISORY LEVELS.
/BD
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 70 81 73 82 / 10 10 10 10
FORT LAUDERDALE 72 81 73 81 / 10 10 10 10
MIAMI 71 81 73 83 / 10 10 10 10
NAPLES 67 81 68 82 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
SHORT TERM...60/BD
LONG TERM....60/BD
AVIATION...10/CD
AREA FORECAST DISCUSSION
NWS MIAMI FL
1004 AM EST THU JAN 1 2015
.UPDATE...
SCATTERED SHOWERS REMAIN THIS MORNING MAINLY ACROSS THE ATLANTIC
WATERS OFF THE PALM BEACHES. WEAK STATIONARY FRONT REMAINS DRAPED
ACROSS THE AREA THIS MORNING CONTRIBUTING TO THE SHOWERS AND
EXTENSIVE CLOUDINESS. LATEST VISIBLE SATELLITE DOES HOWEVER SHOW
CLOUD SHIELD BEGINNING TO ERODE ACROSS BROWARD AND MIAMI-DADE
COUNTIES LATE THIS MORNING. THIS HAS ALLOWED TEMPERATURES TO SURGE
INTO THE MID TO UPPER 70S ALREADY. HRRR CONTINUES TO DEPICT
ISOLATED LIGHT SHOWERS ACROSS MAINLY THE EASTERN HALF OF THE AREA
INTO THE EARLY AFTERNOON HOURS...SO KEPT SLIGHT CHANCE POP GOING.
THE REMAINDER OF THE FORECAST LOOKS ON TRACK AT THIS TIME. UPDATE
SENT.
&&
.PREV DISCUSSION... /ISSUED 649 AM EST THU JAN 1 2015/
AVIATION...
WEAK LOW PRESSURE OVER SOUTHWEST FLORIDA IN COMBINATION WITH
DIFFUSE FRONT NEAR LAKE OKEECHOBEE KEEPING PLENTY OF CLOUDS AND
IFR/MVFR CONDITIONS IN BOTH CEILINGS AND VISIBILITY (MIXTURE OF
SHOWERS AND FOG) ACROSS SOUTH FLORIDA THIS MORNING. BAND OF
SHOWERS NEAR FLL/PBI AREA HAS STAYED MOSTLY OFFSHORE WITH LIGHT
SHOWERS REACHING THE TERMINAL SITES. EXPECT THESE CONDITIONS TO
PERSIST THROUGH ABOUT 15Z, FOLLOWED BY SLOW IMPROVEMENT AS THE LOW
PRESSURE MOVES INTO THE GULF AND THE FRONT CONTINUES TO DISSIPATE.
BY 18Z, EXPECT VFR CONDITIONS TO ONCE AGAIN PREVAIL WITH WIND FLOW
BECOMING LIGHT SE (EXCEPT SEA BREEZE AT KAPF). THIS WILL ALSO
INTRODUCE SLIGHTLY DRIER AIR TO THE AREA WITH COVERAGE OF SHOWERS
DECREASING AS A RESULT. BY THIS EVENING, MOST OF AREA SHOULD BE
FREE OF PRECIPITATION. SOME FOG/LOW CLOUDS COULD ONCE AGAIN FORM
LATE TONIGHT AFTER 06Z, MAINLY INTERIOR AND WESTERN SECTIONS OF
THE PENINSULA. /MOLLEDA
PREV DISCUSSION... /ISSUED 319 AM EST THU JAN 1 2015/
DISCUSSION...
A COMPACT AND WEAK MESOSCALE LOW PASSED SOUTHWARD ACROSS THE
ATLANTIC WATERS YESTERDAY ALONG PALM BEACH COUNTY THEN DRIFTED
WESTWARD ACROSS THE SOUTH FLORIDA PENINSULA EARLY THIS MORNING.
DURING THE EARLY MORNING HOURS SCATTERED SHOWER ACTIVITY OCCURRED
WITH THE GREATEST COVERAGE ACROSS NORTHERN BROWARD COUNTY AND
ACROSS PALM BEACH COUNTY AND ADJACENT ATLANTIC WATERS...WITH THIS
COVERAGE CONTINUING.
THE COMBINATION OF LOW STRATUS AND/OR FOG WILL CONTINUE EARLY THIS
MORNING WITH MOST OF THE COVERAGE EXPECTED ACROSS MIAMI DADE
COUNTY AND SOUTHERN HALF OF BROWARD COUNTY.
THE WILL BE A CHANCE OF RIP CURRENTS TODAY BUT MAINLY EXPECTED
ACROSS THE PALM BEACH COUNTY BEACHES.
THE LATEST MODEL GUIDANCE INDICATES A WEAK SURFACE TROUGH AND
DIFFUSE FRONTAL BOUNDARY CONTINUING ACROSS THE SOUTH FLORIDA
PENINSULA TODAY WITH HIGH PRESSURE THEN STARTING TO BUILD BACK
ACROSS THE REGION THIS EVENING AND OVER NIGHT. THE FORECAST FOR
TODAY IS FOR ISOLATED TO SCATTERED SHOWERS MAINLY ACROSS THE
ATLANTIC WATERS AND THE ATLANTIC METRO AREAS WITH THE GREATEST
COVERAGE CONTINUING TO BE ACROSS BROWARD AND PALM BEACH COUNTIES
AND THE ADJACENT ATLANTIC WATERS. A DRYING TREND IS THEN FORECAST
WITH THE MODEL CONSENSUS INDICATING SOUTHERLY LOW LEVEL FLOW
BRINGING IN DRIER AIR INTO THE REGION TONIGHT INTO FRIDAY. BY
FRIDAY HIGH PRESSURE WILL PREVAIL ACROSS THE REGION WITH A SURFACE
RIDGE EAST OF THE FLORIDA PENINSULA AND AT THE MID TO UPPER LEVELS
A LARGE AMPLITUDE RIDGE BECOMING ESTABLISHED ACROSS THE FLORIDA
STRAITS. THIS PATTERN WILL MORE OR LESS PERSIST THROUGH THE
UPCOMING WEEKEND...WITH STABLE WEATHER CONDITIONS AND INCREASINGLY
WARMER TEMPERATURES PREVAILING ACROSS THE REGION.
FOR THE EXTENDED FORECAST...THE GLOBAL MODEL CONSENSUS INDICATES
THE NEXT COLD FRONT ENTERING THE FLORIDA PANHANDLE AND NORTHERN
FLORIDA ON SUNDAY AND THEN INTO CENTRAL FLORIDA ON MONDAY AND APPROACHING
LAKE OKEECHOBEE AND WEAKENING MONDAY NIGHT. BY TUESDAY THE MODELS
START TO DIVERGE IN THEIR SOLUTIONS...BUT OVER ALL NO SIGNIFICANT
IMPACTS ARE FORECAST THUS FAR FOR SOUTH FLORIDA WITH THE FORECAST
INDICATING JUST A GRADUAL COOL DOWN AND POSSIBLY SOME ISOLATED
SHOWER ACTIVITY. /BD
MARINE...
THE LOCAL PRESSURE GRADIENT ACROSS THE REGION EARLY THIS MORNING
IS SUCH THAT WINDS IN THE 15 TO 20 KNOT RANGE ARE FORECAST ACROSS
THE ATLANTIC WATERS MAINLY TO THE EAST OF PALM BEACH COUNTY AND
ACROSS THE OFF SHORE WATERS...WITH AN SCEC FOR THESE WATERS TODAY.
THE PRESSURE GRADIENT AND RESULTANT WINDS EAST OF PALM BEACH
COUNTY IS FORECAST TO RELAX TONIGHT INTO FRIDAY. FOR THE REMAINDER
OF THE OF THE FORECAST...WINDS AND SEAS ACROSS THE GULF AND
ATLANTIC WATERS ARE FORECAST TO REMAIN WELL BELOW ADVISORY LEVELS.
/BD
&&
.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH 80 70 81 73 / 30 10 10 10
FORT LAUDERDALE 80 72 81 73 / 20 10 10 10
MIAMI 81 71 81 73 / 20 10 10 10
NAPLES 79 67 81 68 / 10 10 10 10
&&
.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&
$$
UPDATE...10/CD
AREA FORECAST DISCUSSION
NWS TALLAHASSEE FL
937 AM EST Thu Jan 1 2015
.Near Term [Through Today]...
Morning satellite imagery shows mid and high clouds streaming
eastward ahead of an upper level trough over the southwest states.
There is also an area of low clouds across portions of the southeast
big bend and south-central Georgia. In between these two areas
around Tallahassee, skies are mostly sunny. Some of the hi-res
guidance such as the 11z HRRR keeps low clouds around the southeast
big bend well into the afternoon hours, and if that occurs we will
end up with another interesting high temperature distribution across
the area today. It is possible that the warmest temperatures today
will be across the central areas away from the high clouds to the
west and low clouds to the east. Clouds will increase across the
entire area tonight from west to east ahead of a developing warm
front across the northern Gulf coast.
&&
.Aviation...
[Through 12z Friday] VFR conditions are expected to prevail for
today across most of the area with light winds. The exception will
be around VLD which will be on the edge of an MVFR cloud deck
through this morning. MVFR conditions may return to the entire area
tonight as moisture increases to the north of a developing warm
front.
&&
.Prev Discussion [423 AM EST]...
.Short Term [Tonight Through Saturday]...
There will be an upper level ridge over the region during this time.
At the sfc, a weak high will be over the Southeast on Friday. By
Saturday, a low from the Gulf will move through the lower MS River
Valley. This low will strengthen quickly as it is supported in the
upper levels by a deep trough moving out of the Southwest states. A
warm front will pass through on Saturday bringing a chance for
rain well ahead of the low, particularly in the northwestern part of
the CWA. Expect cloudy skies with ample moisture from the Atlantic
on Friday, then from the Gulf when winds become southerly on
Saturday. Lows will be in the 40s on Friday morning and 50s on
Saturday morning. Highs will range from the mid 60s to the lower 70s
on Friday. Highs will be in the 70s on Saturday.
.Long Term [Saturday Night Through Thursday]...
By Sunday morning a strong low at the sfc will be over the Great
Lakes region. A cold front will extend all the way to the Gulf
Coast. Rain with some thunder is expected Sunday into Sunday night
as the front moves through. On Monday high pressure will move in
from the west bringing cooler, drier air. No rain is expected for
the rest of the period as high pressure dominates the region. Temps
will shift to seasonal levels after FROPA (50s/60s for highs and
30s/40s for lows).
.Marine...
Light to moderate northeasterly winds will turn southerly by
Saturday. Cautionary level winds are possible on Saturday ahead of a
cold front. Advisory level winds are possible on Monday after the
cold front passes.
.Fire Weather...
No fire weather concerns are expected over the next several days as
afternoon relative humidities will continue to remain well above any
Red Flag concerns.
.Hydrology...
Most of the rivers across the region are slowly subsiding after last
week`s heavy rainfall. Even the Withlacoochee river near Pinetta has
leveled off, and will likely drop into action stage later today.
While rivers outside the lower Withlacoochee/Suwannee area will
continue to fall to below flood stage, this upcoming weekend`s
rainfall totals may not be quite as high as earlier thought,
especially where the current stages and potential problems would be
the highest. At present, storm total QPF is expected to range from
around 0.5 inches over the Suwannee and Withlacoochee basins, with
a gradual increasing trend to the N and W. The highest totals of
1.5" to 2.5" appear likely over far western portions of the FL
Panhandle as well as SE AL, which fortunately contain the basins
which can handle those amounts of rainfall over a short period of
time without too many concerns.
Detailed information pertaining to current river stages and
forecasts can be found at: http://water.weather.gov/ahps.
&&
.Preliminary Point Temps/PoPs...
Tallahassee 66 48 70 57 78 / 10 20 30 20 20
Panama City 63 53 68 61 74 / 0 20 40 30 40
Dothan 59 46 63 55 74 / 0 20 60 40 50
Albany 59 44 64 52 74 / 0 20 50 30 40
Valdosta 62 46 69 56 78 / 10 10 30 20 20
Cross City 63 50 75 58 81 / 10 10 30 20 10
Apalachicola 64 54 67 62 73 / 0 20 30 20 30
&&
.TAE Watches/Warnings/Advisories...
FL...None.
GA...None.
AL...None.
GM...None.
&&
$$
NEAR TERM...DVD
SHORT TERM...MCDERMOTT
LONG TERM...MCDERMOTT
AVIATION...DVD
MARINE...MCDERMOTT
FIRE WEATHER...GOULD
HYDROLOGY...GOULD
AREA FORECAST DISCUSSION
NWS POCATELLO ID
201 PM MST THU JAN 1 2015
.SHORT TERM...TONIGHT THROUGH SUNDAY. THE LATEST SATELLITE IMAGERY
WAS CLEARLY SHOWING A BROAD AREA OF STRATUS/LOW CLOUDS EXTENDING
FROM BOISE UP THE VALLEY THROUGH POCATELLO. NUMERICAL MODELS SHOW
THE STRATUS WORKING FURTHER NE TONIGHT AND LINGERING THROUGH A GOOD
PORTION OF THE MORNING FRIDAY BEFORE GRADUALLY DISSIPATING AHEAD OF
AN INCOMING SYSTEM. FURTHER UPSTREAM...A VIGOROUS PAC STORM SYSTEM
WAS SPREADING INTO THE NW BRITISH COLUMBIA COAST. THE MODELS SHEAR
THIS WAVE SE ACROSS THE CANADIAN ROCKIES TONIGHT/FRIDAY AND ALONG
THE MONTANA/WYOMING DIVIDE FRIDAY NIGHT/SATURDAY WITH ATTENDING
SNOWFALL IMPACTING MAINLY THE NE MOUNTAINS. STORM TOTAL
ACCUMULATIONS OF 1 TO 4 INCHES ARE ANTICIPATED FRIDAY NIGHT/SATURDAY
IN THE MOUNTAINS FROM ISLAND PARK SOUTH THROUGH SODA SPRINGS. SOME
EROSION OF THE COLD AIR TRAPPED IN THE VALLEYS IS ALSO ANTICIPATED
LATE FRIDAY AFTERNOON/SATURDAY. A SECOND STRONGER SYSTEM HITS THE NW
BRITISH COLUMBIA COAST SUNDAY WHILE THE ASSOCIATED PRECIPITATION
BEGINS TO SPREAD INTO THE NRN AND ERN MOUNTAINS AS EARLY AS SATURDAY
NIGHT AND CONTINUES THROUGH SUNDAY AND MONDAY. CONTINUED WARMING IS
EXPECTED SUNDAY AS SW WINDS BEGIN TO SCOUR OUT THE REMAINING COLD
AIR TRAPPED IN THE VALLEYS. HUSTON
.LONG TERM...SUNDAY NIGHT THROUGH NEXT THURSDAY NIGHT. ONLY ONE
SIGNIFICANT TROUGH PASSING THROUGH EARLY DURING THE EXTENDED PERIOD.
EXPECTED TO MAINLY AFFECT THE MOUNTAINS WITH A MODERATE AMOUNT OF
SNOW...WHILE THE LOWER ELEVATIONS WILL SEE EITHER RAIN OR SNOW WITH
ONLY LIGHT ACCUMULATION. THIS WILL MAINLY BE SUN NIGHT AND MON.
AFTER THIS...AN UPPER LEVEL HIGH MOVES IN FROM THE SOUTH...KEEPING
MILD AIR AND LOWER ELEVATION TEMPERATURES IN AT LEAST THE UPPER 30S.
AT THE VERY END...CLOUDS START TO OVERSPREAD AGAIN FROM THE WEST AS
ANOTHER LOW ENTERS THE NORTH AMERICAN WEST COAST. GFS IS TENDING TO
BE THE DRIER GUIDANCE COMPARED TO ECMWF. THE ECMWF IS ALSO MUCH
WARMER WITH HIGHER 500MB HEIGHTS AND THUS WARMER AIRMASS. HAVE SIDED
A LITTLE MORE TOWARDS THE GFS...ESPECIALLY FOR OVERNIGHT LOWS.
MESSICK
&&
.AVIATION...STRATUS AND FOG COULD...AND SHOULD...BE A PROBLEM AGAIN
TONIGHT. BUT IT IS A LOW CONFIDENCE FORECAST BASED ON SEVERAL
ISSUES. THE PRESSURE GRADIENT ACROSS THE EASTERN MAGIC VALLEY AND
SNAKE RIVER PLAIN WILL INFLUENCE WIND TO BE WESTERLY...WHILE THE
NATURAL SLOPE-VALLEY EFFECT WOULD BE THE OPPOSITE. THE SPREAD OF
STRATUS BACK OVER THE THREE VALLEY AIRDROMES IS COMPLETELY DEPENDENT
ON THE WIND FLOW. HRRR FORECAST INDICATES NORTHEAST TO EAST GRADIENT
DEVELOPS AND KEEPS THE STRATUS AWAY FROM THE LOW ELEVATION AIRPORTS.
BOUNDARY LAYER MOISTURE PROGS AND STATISTICS INDICATE THE STRATUS
SHOULD RECUR...PLUS THE STRATUS HAS IN NO WAY TOTALLY EVAPORATED.
THUS HAVE HAD IT REDEVELOP AND BE EVEN LOWER THAN IT WAS LAST NIGHT.
MEANWHILE...AT KSUN THE STRATUS DID ADVECT UP THE VALLEY WITH THE
ONSET OF SOUTHEAST WIND...BUT IT PULLED UP SHORT AND THINNED WITH
THE DIURNAL WARMING. FEEL MORE CONFIDENT ABOUT THIS ONE THAT THE FOG
WILL STAY AWAY AT LEAST THROUGH THE LATE NIGHT AND MORNING HOURS OF
THE TAF. NO SIGNIFICANT WINDSPEEDS EXPECTED. MESSICK
&&
.PIH WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
523 PM CST FRI JAN 2 2015
...UPDATED AVIATION DISCUSSION...
.SHORT TERM...(THIS EVENING THROUGH SATURDAY)
ISSUED AT 332 PM CST FRI JAN 2 2015
A VERY CHALLENGING AND POTENTIALLY VERY HAZARDOUS WINTER WEATHER
EVENT IS ABOUT TO UNFOLD. LATE THIS AFTERNOON ON WATER VAPOR LOOP,
THE CENTER OF THE MID LATITUDE CYCLONE WAS OVER THE TRI-BORDER OF
NEW MEXICO, ARIZONA, AND MEXICO. OVER THE PAST COUPLE OF HOURS,
INFRARED SATELLITE SHOWED SUBSTANTIAL CLOUD COOLING IN DEVELOPING
BAROCLINIC LEAF ACROSS FAR EASTERN NEW MEXICO AND WEST TEXAS.
WIDESPREAD WINTER PRECIPITATION WILL EXPAND NORTH TONIGHT, REACHING
THE SOUTHWEST KANSAS-OKLAHOMA BORDER BY DAYBREAK SATURDAY. ALL THE
THERMAL FORECAST SOUNDINGS SUGGEST SNOW AS THE PRECIPITATION TYPE,
ALTHOUGH INITIALLY THE SOUNDING WILL BE SLIGHTLY ABOVE THE ZERO
ISOTHERM. ONCE THE LOWER TROPOSPHERE WET-BULBS THOUGH, THE SOUNDING
WILL BE SUPPORTIVE OF SNOW.
NOW THE QUESTION OF WHERE THE DEFORMATION BAND WILL SET UP. EARLIER
THIS MORNING, THE HIGH-RESOLUTION WRF MODEL RUNS WERE IN LINE WITH
THE 12KM NAM IN SETTING UP THE MAIN DEFORMATION AXIS FROM THE
OKLAHOMA PANHANDLE...EAST-NORTHEASTWARD ACROSS MEADE COUNTY THEN
TOWARD KIOWA AND PRATT/BARBER COUNTY. THERE WAS FAIRLY GOOD SUPPORT
FOR THIS WITH THE 700MB LOW TRACKING ACROSS THIS AREA. WITHIN THIS
AXIS, 3 TO 5 INCHES OF SNOW IS LIKELY. MUCH LIKE OTHER DEFORMATION
SNOW EVENTS OF THE PAST, THERE WILL LIKELY BE A VERY SHARP CUTOFF IN
SNOWFALL AMOUNTS. DURING THE SNOW EVENT (DAYTIME HOURS SATURDAY),
WINDS WILL BE FAIRLY MANAGEABLE, IN THAT BLOWING AND DRIFTING SHOULD
NOT BE A PROBLEM. HOWEVER, LATE IN THE AFTERNOON, AN ARCTIC FRONT
WILL BE CHARGING SOUTH AND THE SHARP PRESSURE RISES BEHIND THE FRONT
WILL LEAD TO A SUBSTANTIAL INCREASE IN WINDS. WE USED THE ECMWF
MODEL AND GFS BUFR SOUNDINGS AS GUIDANCE FOR THE SURFACE WINDS. THE
GFS BUFR SOUNDINGS SUPPORT THE VERY STRONG ECMWF WINDS. IT IS
UNUSUAL TO SEE THE ECMWF MODEL SURFACE WINDS STRONGER THAN ANY OTHER
MODEL. THIS BEGS THE QUESTION IF THE MESOSCALE MODELS ARE EVEN
HANDLING THIS ARCTIC AIRMASS ADEQUATELY. THE GFS BUFR SOUNDINGS FROM
00Z TO 09Z SUNDAY SHOW THE CLASSIC COLD ADVECTION MIXED LAYER. ONLY
ABOUT 200 METERS AGL, THE FORECAST SOUNDING SHOWS WINDS 30 TO 35
KNOTS, SO THIS IS CERTAINLY SUPPORTIVE OF SUSTAINED 24 TO 27
KNOTS OR SO AT THE SURFACE.
THESE WINDS WILL UNDOUBTEDLY CAUSE SOME SIGNIFICANT BLOWING AND
DRIFTING PROBLEMS SATURDAY NIGHT...ESPECIALLY ACROSS AREAS THAT
RECEIVE A FRESH COUPLE INCHES OF SNOW. IF THERE IS MORE THAN 3
INCHES OF FRESH SNOW WITH THESE WINDS, GROUND BLIZZARD CONDITIONS
WILL PROBABLY OCCUR...AND A BLIZZARD HEADLINE MAY BE REQUIRED FOR A
PART OF SATURDAY NIGHT. THERE IS STILL JUST A BIT OF UNCERTAINTY IN
SNOWFALL AND WIND SPEEDS TO HOLD OFF ON UPGRADING A WINTER WEATHER
ADVISORY, BUT WE ADVISED LOCAL PARTNERS THROUGH CONFERENCE CALL AS
WELL AS SOCIAL MEDIA ABOUT THE INCREASED HAZARD/RISK SATURDAY NIGHT
SHOULD THE SNOW AND WIND COMPONENT PAN OUT. IN ADDITION, BY MIDNIGHT
SATURDAY NIGHT, WIND CHILLS WILL PLUMMET TO BETWEEN 10 AND 15
DEGREES BELOW ZERO...AND STILL FALLING. EXTRA CAUTION IS CERTAINLY
ADVISED TO ANYONE HEADING OUT SATURDAY NIGHT.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 111 PM CST FRI JAN 2 2015
A STRONG ANTICYCLONE WILL CONTINUE ACROSS THE GREAT PLAINS ON SUNDAY
WITH CONTINUED COLD 850-HPA TEMPERATURES AROUND -10C. UNDERCUT GUIDANCE
AND WAS MORE IN WITH THE ECMWF, WHICH SHOWS MAXIMUMS MORE IN THE TEENS
RATHER THAN THE 20S. SAME COLDER SOLUTION WAS APPLIED TO THE MINIMUM
TEMPERATURE MONDAY AND THE MAXIMUM TEMPERATURE MONDAY WITH LOWS IN
THE SINGLE DIGITS AND HIGHS MODERATING SOMEWHAT TO MAINLY THE 20S. THE
NEXT CHANCE FOR LIGHT PRECIPITATION COMES IN ABOUT A WEEK FROM
NOW. SUPERBLEND SLIGHT POPS LOOK FINE FOR NOW.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 521 PM CST FRI JAN 2 2015
LOW LEVEL MOISTURE AND LIFT WILL IMPROVE LATE TONIGHT AND EARLY
SATURDAY ACROSS WESTERN KANSAS AS AN UPPER LEVEL LOW LIFTS
NORTHEAST FROM SOUTHWEST NEW MEXICO INTO THE TEXAS PANHANDLE. VFR
CEILINGS WILL LOWER DURING THE OVERNIGHT HOURS WITH MVFR
CONDITIONS ARE EXPECTED TO DEVELOP IN THE DDC AREA BETWEEN 09Z
AND 15Z SATURDAY AND AROUND GCK BETWEEN 12Z AND 18Z SATURDAY BASED
ON THE MODEL SOUNDING FROM THE LATEST RAP AND NAM. CEILINGS WILL
THEN CONTINUE TO LOWER AND IN THE DDC AREA THE VISIBILITIES ARE
EXPECTED TO FALL BACK TO LESS THAN 3 MILES AFTER 15Z SATURDAY THE
SNOW BECOMES STEADIER AND HEAVIER AT TIMES. IN HYS...MVFR CEILINGS
ARE EXPECTED AFTER 18Z WITH CEILINGS CONTINUING TO LOWER THROUGH
THE REMAINDER OF THE AFTERNOON. SOME LIGHT SNOW WILL ALSO BE
POSSIBLE DURING THE AFTERNOON HOURS WHICH WILL REDUCE VISIBILITIES
AT TIMES. LIGHT WESTERLY WINDS WILL SHIFT TO THE NORTHWEST EARLY
SATURDAY AND BY SATURDAY AFTERNOON INCREASE TO AROUND 20 KNOTS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 19 29 5 15 / 60 80 30 0
GCK 16 28 2 16 / 60 80 30 0
EHA 19 31 7 26 / 80 80 20 0
LBL 19 29 7 20 / 80 100 30 0
HYS 15 29 1 12 / 30 80 50 0
P28 22 32 9 22 / 80 70 50 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 5 PM CST /4 PM MST/ SATURDAY TO
MIDNIGHT CST /11 PM MST/ SATURDAY NIGHT FOR KSZ030-031-043>046-
061>064-074.
WINTER WEATHER ADVISORY FROM 3 AM SATURDAY TO MIDNIGHT CST
SATURDAY NIGHT FOR KSZ065-066-075>081-084>090.
&&
$$
SHORT TERM...UMSCHEID
LONG TERM...SUGDEN
AVIATION...BURGERT
AREA FORECAST DISCUSSION
NWS JACKSON KY
1033 PM EST FRI JAN 2 2015
.UPDATE...
ISSUED AT 1032 PM EST FRI JAN 2 2015
SHOWERS HAVE ATTEMPTED TO PUSH INTO SOUTHERN KENTUCKY...BUT DRY AIR
SEEMS TO BE WINNING OUT AS MUCH OF THIS APPEARS TO BE WEAKENING AS IT
HEADS NORTH. IN FACT...LONDON CIGS HAVE INCREASED TO 9KFT. THIS
DEMONSTRATES THE ABUNDANCE OF LOW LEVEL DRY AIR IN PLACE. THUS...PLAN
TO SCALE BACK POPS A BIT OVER THE NEXT FEW HOURS...BUT LEAVE
SCATTERED COVERAGE IN THE SOUTHWEST AND WEST...TAPERING OFF TO
ISOLATED IN THE EAST. THIS MAY STILL BE OVERDONE AS DOWNSLOPING WINDS
CONTINUE TO ERODE PRECIPITATION AS IT HEADS NORTH. FORCING APPEARS TO
JUST BE TOO WEAK TO OVERCOME THE DRY AIR. MODELS ARE SHOWING A BETTER
SURGE OF LIFT AND MOISTURE BETWEEN 7 AND 10 AM IN THE MORNING.
PERHAPS THIS MAY BE THE BEST OPPORTUNITY FOR BETTER SHOWER COVERAGE.
HOWEVER...FOR NOW...OPTING TO LEAVE THE FORECAST ALONE AND ONLY TOUCH
THE NEXT FEW HOURS TO ADJUST FOR THE CURRENT TRENDS. DID ADJUST WINDS
UPWARDS ON THE HIGH TERRAIN IN THE SOUTHEAST LATE TONIGHT THROUGH
TOMORROW AS 900MB WINDS INCREASE TO AROUND 40 KNOTS. THIS SHOULD
PRODUCE SOME STRONG GUSTY WINDS ON THE HIGHER TERRAIN. WITH INVERSION
HOLDING TOUGH ON SATURDAY...WINDS MAY NOT TURN ALL THAT GUSTY
ELSEWHERE. HOWEVER...IF WE CAN GET SOME CLEARING...THAT WOULD
CERTAINLY HELP TO MIX DOWN SOME STRONGER WINDS.
UPDATE ISSUED AT 853 PM EST FRI JAN 2 2015
WHILE ONLY A FEW SPRINKLES REMAIN ACROSS THE NORTH PRESENTLY...AN
AREA OF RAIN HAS DEVELOPED ACROSS CENTRAL TENNESSEE. THIS RAIN WILL
BE PUSHING NORTHEAST INTO SOUTH CENTRAL KENTUCKY OVER THE NEXT FEW
HOURS. HAVE ADJUSTED POPS TO TIME THIS AREA OF PRECIPITATION
NORTHWARD ACROSS CENTRAL KENTUCKY. THE EASTWARD EXTENT IS STILL IN
QUESTION DUE TO DRIER DOWNSLOPING FLOW (HIGHER CIG HEIGHTS)...SO
WILL GO WITH AN EAST TO WEST GRADIENT IN POPS. HRRR HAS PICKED UP ON
THIS FEATURE WITH THE LAST FEW RUNS AND SHOWS ANOTHER LULL AS THIS
AREA PUSHES NORTH BY EARLY MORNING. HOWEVER...WILL LEAVE SOME LOW
POPS IN THROUGH THE REMAINDER OF THE NIGHT AS WE COULD SEE SHOWERS
POP UP AT ANY TIME GIVEN THE SATURATED ENVIRONMENT. HOWEVER...OUTSIDE
OF THE RAIN PUSHING NORTHWARD NOW...IT LOOKS LIKE THE ACTIVITY
THROUGH THE REMAINDER OF THE NIGHT MAY BE MORE ISOLATED.
UPDATE ISSUED AT 544 PM EST FRI JAN 2 2015
UPDATED FORECAST TO LOWER POPS THROUGH THE EVENING. STILL HAVE MODEST
DEWPOINT DEPRESSIONS OUT THERE. A FEW BETTER RETURNS ARE COMING OUT
OF CENTRAL KENTUCKY...BUT FOR THE MOST PART THE BETTER RETURNS ARE
VERY ISOLATED. IN FACT...NOT MANY STATIONS REPORTING MEASURABLE
PRECIPITATION EVEN WITH THE HEAVIER RETURNS. THUS...WILL CUT DOWN
POPS THROUGH 06Z. HRRR/RAP CONTINUE TO SUPPORT VERY LITTLE EVEN
THROUGH THE REST OF THE NIGHT. THIS COULD BE THE CASE GIVEN THE
SOUTH/SOUTHEAST WINDS WILL ONLY STRENGTHEN AS WE HEAD THROUGH THE
NIGHT...KEEPING THE FLOW DOWNSLOPING INTO EASTERN KENTUCKY.
HOWEVER...NOT WILLING TO GO TOO LOW QUITE YET AS BETTER JET ARRIVES
TOWARDS DAYBREAK AND COULD KICK START THINGS LATE TONIGHT.
HOWEVER...UNTIL THE FLOW GOES MORE SOUTH/SOUTHWEST...WE MAY NOT SEE
MUCH RAIN SHOWER ACTIVITY. CERTAINLY SOMETHING TO WATCH TONIGHT.
ALSO...NO SUPPORT FOR THUNDER...ESPECIALLY SINCE PRECIPITATION MAY BE
LACKING TO BEGIN WITH. THUS...WILL PULL THUNDER CHANCES FROM TONIGHT
INTO TOMORROW. ANY THUNDER WILL LIKELY COME WITH THE COLD FRONT
TOMORROW NIGHT...BUT EVEN THERE INSTABILITY IS WEAK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 353 PM EST FRI JAN 2 2015
HIGH PRESSURE CONTINUES TO SIT ACROSS THE FAR EASTERN PORTION OF THE
CWA AND WILL CONTINUE TO DRIFT NORTHEASTWARD THROUGHOUT THE
AFTERNOON/EVENING. AS IT DOES...A SURFACE LOW PRESSURE SYSTEM WILL
LIFT FROM LOUISIANA AND QUICKLY NORTHEASTWARD...PULLING A QUICK
MOVING WARM FRONT ACROSS THE REGION BETWEEN 12 AND 18Z TOMORROW WITH
STRONG SOUTHERLY FLOW. THIS WILL PUT EASTERN KY IN THE WARM SECTOR
THROUGH THE REST OF SATURDAY AFTERNOON...BEFORE THE COLD FRONT SWEEPS
FROM WEST TO EAST SATURDAY NIGHT INTO SUNDAY MORNING.
MVFR CLOUD COVER HAS OVERSPREAD THE REGION IN ADVANCE OF THIS
SYSTEM...WITH ISL/SCT LIGHT RAIN CONTINUING TO SHOW UP OVER PORTIONS
OF THE STATE. EXPECT THIS RAIN TO INTENSIFY AS WE HEAD INTO THE
EVENING AND OVERNIGHT TONIGHT...AS THE WARM FRONT PUSHES NORTHWARD
AND BRINGS MOISTURE FLOW IN FROM THE SOUTH. MODEL SOUNDINGS ARE STILL
SHOWING A VERY IMPRESSIVE LOW LEVEL INVERSION DEVELOPING OVERNIGHT
WITH A MID LEVEL WARM NOSE KEEPING PRECIP WELL ABOVE FREEZING UNDER
STRONG SW FLOW. CONTINUED WITH MENTION OF THUNDER POSSIBILITIES
DURING THE LATE NIGHT AND INTO THE DAY TOMORROW AS THE WARM FRONT
MOVES THROUGH THE REGION. THE INCREASED LIFT WITH THE BOUNDARY...IN
ADDITION TO THE WARM UNSTABLE AIR...COULD LEAD TO SOME ELEVATED
CONVECTION IN THE AREA. TEMPERATURES WILL MAKE AN IMPRESSIVE JUMP
INTO THE UPPER 50S TO AROUND 60 BY TOMORROW AFTERNOON UNDER THIS
STRONG SOUTHERLY FLOW. IT IS POSSIBLE THAT WE MAY GET DRY SLOTTED IN
THE SE TOMORROW ONCE THE WARM FRONT PASSES THROUGH...AND BEFORE THE
INFLUENCE OF THE COLD FRONT...BUT KEPT IN LOWER CHANCE POPS JUST IN
CASE SOME SCATTERED CONVECTION LINGERS.
EXPECT THE WARMER TEMPS AND PRECIP CHANCES TO CONTINUE INTO THE
OVERNIGHT HOURS TOMORROW NIGHT AS THE WARM FRONT BECOMES STALLED TO
OUR NORTH AND WE AWAIT THE APPROACHING COLD FRONT...WHICH THE LATEST
GFS HAS SET TO PASS THROUGH AROUND 6Z. IT IS JUST BEFORE AND DURING
THE PASSAGE OF THE COLD FRONT THAT WE WILL LIKELY SEE OUR MOST
WIDESPREAD POPS AND HIGHEST QPF. UP TO AN INCH OF QPF COULD FALL
BETWEEN 0 AND 12Z SUNDAY...WHICH IS PRETTY CONSISTENT BETWEEN THE
LAST FEW MODEL RUNS...FORECAST PACKAGES...AND BETWEEN THE NEIGHBORING
OFFICES. IN ADDITION TO MORE WIDESPREAD RAIN...FORECAST SOUNDINGS ARE
ALSO SHOWING HEAVIER CONVECTIVE/THUNDERSTORM POTENTIAL SATURDAY
EVENING/SATURDAY NIGHT...WITH VERY STRONG LOW LEVEL WIND SHEAR AND
PRESENT ON THE LATEST NAM12 AND GFS40 FORECAST SOUNDINGS...A VERY SMALL
LOW LEVEL INVERSION...INCREASING LAPSE RATES...AND PWAT VALUES WELL
OVER AN INCH /ALMOST AN INCH AND A HALF/.
THE COLD FRONT WILL PASS THROUGH AFTER 6Z ACROSS MUCH OF THE
CWA...WITH THE BEST CONVECTIVE POTENTIAL AND HEAVIEST RAINFALL
PUSHING OUT WITH IT. HAVE POPS STARTING TO TAPER DOWN FROM DEFINITE
TO CHANCES DURING THE LAST 6 HOURS OF THE SHORT TERM FORECAST
PERIOD. FORECAST SOUNDINGS ARE SHOWING A FAST INTRUSION OF DRY AIR
IN THE MID AND UPPER LEVELS...SO EXPECT PRECIP RATES TO DIMINISH
QUICKLY BY DAWN. A LINGERING THUNDERSTORM WILL STILL BE A
POSSIBILITY...THOUGH IT SHOULD BE IN A WEAKENING/DYING STATE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 306 PM EST FRI JAN 2 2015
THE EXTENDED PERIOD BEGINS WARM AND WET ON SUNDAY MORNING JANUARY
THE FOURTH. A LARGE SWATH OF LIGHT TO MODERATE RAIN IS PROGGED TO
MOVE ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS ALONG AND JUST
AHEAD OF A VERY POTENT COLD FRONT. THE RAIN IS EXPECTED TO GRADUALLY
TAPER OFF FROM WEST TO EASTERN SUNDAY AND SUNDAY NIGHT AS THE FRONT
MOVES THROUGH. THE PRECIPITATION SHOULD BE OUT OF THE AREA BY LATE
SUNDAY NIGHT. AFTER THAT...A FRIGID ARCTIC AIR MASS IS EXPECTED TO
SETTLE OVER THE REGION FOR A FEW DAYS. AFTER A MODEST COOL DOWN
SUNDAY NIGHT...DURING WHICH TIME TEMPERATURES ARE EXPECTED TO DROP
INTO THE 20S ACROSS THE AREA...A SECOND REINFORCING SHOT OF COLD AIR
IS EXPECTED TO INVADE THE AREA TUESDAY NIGHT...AS A FAST MOVING
CLIPPER SYSTEM PASSES BY JUST TO OUR NORTH. BASED ON THE LATEST MOS
GUIDANCE AND MODEL SOUNDINGS...THE MERCURY COULD DROP INTO THE TEENS
AND LOW 20S TUESDAY NIGHT...AND PERHAPS EVEN INTO THE SINGLE DIGITS
WEDNESDAY NIGHT. THE CULPRIT OF THESE FRIGID TEMPERATURES WOULD COME
IN THE FORM OF A LARGE RIDGE OF ARCTIC HIGH PRESSURE THAT IS
EXPECTED TO SETTLE OVER THE EASTERN CONUS MID WEEK. AFTER SUNDAY AND
SUNDAY NIGHT...THE ONLY PRECIPITATION THAT MAY AFFECT THE AREA WOULD
COME TUESDAY AFTERNOON AND EVENING AS THE CLIPPER SYSTEM MOVES PAST.
ANY RAIN OR SNOW THAT FALLS THAT DAY WOULD LIKELY OCCUR NORTH OF THE
MOUNTAIN PARKWAY WITH LITTLE ACCUMULATION EXPECTED. THE REST OF THE
WEEK IS FORECAST TO BE DRY AND QUITE COLD. HIGHS ON WEDNESDAY AND
THURSDAY MAY NOT CLIMB OUT OF THE 20S. MONDAY LOOKS TO BE PRETTY
COLD AS WELL...WITH HIGHS IN THE 30S ANTICIPATED ON THAT DAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 642 PM EST FRI JAN 2 2015
SOUTH-SOUTHEAST FLOW AHEAD OF AN APPROACHING WARM FRONT WILL
STRENGTHEN TONIGHT AS IT PUSHES NORTHWARD. THIS WILL YIELD
DOWNSLOPING FLOW OFF THE HIGH TERRAIN ACROSS EASTERN KENTUCKY. THIS
SHOULD HELP KEEPING CIGS A BIT HIGHER THROUGH THE NIGHT. THE BEST
CHANCES FOR PERIODS OF MVFR CIGS WILL BE ACROSS SOUTH-CENTRAL
KENTUCKY...WHICH WILL BE LESS INFLUENCED BY THIS DOWNSLOPING FLOW.
WHILE A RAIN SHOWER MAY BE POSSIBLE OVERNIGHT...BEST RAIN CHANCES
SHOULD HOLD OFF UNTIL LATE. MAINLY VFR CONDITIONS SHOULD PREVAIL FOR
THE EASTERN TAF SITES. MAIN AVIATION CONCERN WILL BE DEVELOPING LLWS
LATE TONIGHT AND TOMORROW AS WINDS STRENGTHEN JUST OFF THE SURFACE TO
BETWEEN 40 AND 45 KNOTS. THIS WILL LIKELY PERSIST THROUGH THE DAY AS
THE INVERSION HOLDS TOUGH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS JACKSON KY
853 PM EST FRI JAN 2 2015
.UPDATE...
ISSUED AT 853 PM EST FRI JAN 2 2015
WHILE ONLY A FEW SPRINKLES REMAIN ACROSS THE NORTH PRESENTLY...AN
AREA OF RAIN HAS DEVELOPED ACROSS CENTRAL TENNESSEE. THIS RAIN WILL
BE PUSHING NORTHEAST INTO SOUTH CENTRAL KENTUCKY OVER THE NEXT FEW
HOURS. HAVE ADJUSTED POPS TO TIME THIS AREA OF PRECIPITATION
NORTHWARD ACROSS CENTRAL KENTUCKY. THE EASTWARD EXTENT IS STILL IN
QUESTION DUE TO DRIER DOWNSLOPING FLOW (HIGHER CIG HEIGHTS)...SO
WILL GO WITH AN EAST TO WEST GRADIENT IN POPS. HRRR HAS PICKED UP ON
THIS FEATURE WITH THE LAST FEW RUNS AND SHOWS ANOTHER LULL AS THIS
AREA PUSHES NORTH BY EARLY MORNING. HOWEVER...WILL LEAVE SOME LOW
POPS IN THROUGH THE REMAINDER OF THE NIGHT AS WE COULD SEE SHOWERS
POP UP AT ANY TIME GIVEN THE SATURATED ENVIRONMENT. HOWEVER...OUTSIDE
OF THE RAIN PUSHING NORTHWARD NOW...IT LOOKS LIKE THE ACTIVITY
THROUGH THE REMAINDER OF THE NIGHT MAY BE MORE ISOLATED.
UPDATE ISSUED AT 544 PM EST FRI JAN 2 2015
UPDATED FORECAST TO LOWER POPS THROUGH THE EVENING. STILL HAVE MODEST
DEWPOINT DEPRESSIONS OUT THERE. A FEW BETTER RETURNS ARE COMING OUT
OF CENTRAL KENTUCKY...BUT FOR THE MOST PART THE BETTER RETURNS ARE
VERY ISOLATED. IN FACT...NOT MANY STATIONS REPORTING MEASURABLE
PRECIPITATION EVEN WITH THE HEAVIER RETURNS. THUS...WILL CUT DOWN
POPS THROUGH 06Z. HRRR/RAP CONTINUE TO SUPPORT VERY LITTLE EVEN
THROUGH THE REST OF THE NIGHT. THIS COULD BE THE CASE GIVEN THE
SOUTH/SOUTHEAST WINDS WILL ONLY STRENGTHEN AS WE HEAD THROUGH THE
NIGHT...KEEPING THE FLOW DOWNSLOPING INTO EASTERN KENTUCKY.
HOWEVER...NOT WILLING TO GO TOO LOW QUITE YET AS BETTER JET ARRIVES
TOWARDS DAYBREAK AND COULD KICK START THINGS LATE TONIGHT.
HOWEVER...UNTIL THE FLOW GOES MORE SOUTH/SOUTHWEST...WE MAY NOT SEE
MUCH RAIN SHOWER ACTIVITY. CERTAINLY SOMETHING TO WATCH TONIGHT.
ALSO...NO SUPPORT FOR THUNDER...ESPECIALLY SINCE PRECIPITATION MAY BE
LACKING TO BEGIN WITH. THUS...WILL PULL THUNDER CHANCES FROM TONIGHT
INTO TOMORROW. ANY THUNDER WILL LIKELY COME WITH THE COLD FRONT
TOMORROW NIGHT...BUT EVEN THERE INSTABILITY IS WEAK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 353 PM EST FRI JAN 2 2015
HIGH PRESSURE CONTINUES TO SIT ACROSS THE FAR EASTERN PORTION OF THE
CWA AND WILL CONTINUE TO DRIFT NORTHEASTWARD THROUGHOUT THE
AFTERNOON/EVENING. AS IT DOES...A SURFACE LOW PRESSURE SYSTEM WILL
LIFT FROM LOUISIANA AND QUICKLY NORTHEASTWARD...PULLING A QUICK
MOVING WARM FRONT ACROSS THE REGION BETWEEN 12 AND 18Z TOMORROW WITH
STRONG SOUTHERLY FLOW. THIS WILL PUT EASTERN KY IN THE WARM SECTOR
THROUGH THE REST OF SATURDAY AFTERNOON...BEFORE THE COLD FRONT SWEEPS
FROM WEST TO EAST SATURDAY NIGHT INTO SUNDAY MORNING.
MVFR CLOUD COVER HAS OVERSPREAD THE REGION IN ADVANCE OF THIS
SYSTEM...WITH ISL/SCT LIGHT RAIN CONTINUING TO SHOW UP OVER PORTIONS
OF THE STATE. EXPECT THIS RAIN TO INTENSIFY AS WE HEAD INTO THE
EVENING AND OVERNIGHT TONIGHT...AS THE WARM FRONT PUSHES NORTHWARD
AND BRINGS MOISTURE FLOW IN FROM THE SOUTH. MODEL SOUNDINGS ARE STILL
SHOWING A VERY IMPRESSIVE LOW LEVEL INVERSION DEVELOPING OVERNIGHT
WITH A MID LEVEL WARM NOSE KEEPING PRECIP WELL ABOVE FREEZING UNDER
STRONG SW FLOW. CONTINUED WITH MENTION OF THUNDER POSSIBILITIES
DURING THE LATE NIGHT AND INTO THE DAY TOMORROW AS THE WARM FRONT
MOVES THROUGH THE REGION. THE INCREASED LIFT WITH THE BOUNDARY...IN
ADDITION TO THE WARM UNSTABLE AIR...COULD LEAD TO SOME ELEVATED
CONVECTION IN THE AREA. TEMPERATURES WILL MAKE AN IMPRESSIVE JUMP
INTO THE UPPER 50S TO AROUND 60 BY TOMORROW AFTERNOON UNDER THIS
STRONG SOUTHERLY FLOW. IT IS POSSIBLE THAT WE MAY GET DRY SLOTTED IN
THE SE TOMORROW ONCE THE WARM FRONT PASSES THROUGH...AND BEFORE THE
INFLUENCE OF THE COLD FRONT...BUT KEPT IN LOWER CHANCE POPS JUST IN
CASE SOME SCATTERED CONVECTION LINGERS.
EXPECT THE WARMER TEMPS AND PRECIP CHANCES TO CONTINUE INTO THE
OVERNIGHT HOURS TOMORROW NIGHT AS THE WARM FRONT BECOMES STALLED TO
OUR NORTH AND WE AWAIT THE APPROACHING COLD FRONT...WHICH THE LATEST
GFS HAS SET TO PASS THROUGH AROUND 6Z. IT IS JUST BEFORE AND DURING
THE PASSAGE OF THE COLD FRONT THAT WE WILL LIKELY SEE OUR MOST
WIDESPREAD POPS AND HIGHEST QPF. UP TO AN INCH OF QPF COULD FALL
BETWEEN 0 AND 12Z SUNDAY...WHICH IS PRETTY CONSISTENT BETWEEN THE
LAST FEW MODEL RUNS...FORECAST PACKAGES...AND BETWEEN THE NEIGHBORING
OFFICES. IN ADDITION TO MORE WIDESPREAD RAIN...FORECAST SOUNDINGS ARE
ALSO SHOWING HEAVIER CONVECTIVE/THUNDERSTORM POTENTIAL SATURDAY
EVENING/SATURDAY NIGHT...WITH VERY STRONG LOW LEVEL WIND SHEAR AND
PRESENT ON THE LATEST NAM12 AND GFS40 FORECAST SOUNDINGS...A VERY SMALL
LOW LEVEL INVERSION...INCREASING LAPSE RATES...AND PWAT VALUES WELL
OVER AN INCH /ALMOST AN INCH AND A HALF/.
THE COLD FRONT WILL PASS THROUGH AFTER 6Z ACROSS MUCH OF THE
CWA...WITH THE BEST CONVECTIVE POTENTIAL AND HEAVIEST RAINFALL
PUSHING OUT WITH IT. HAVE POPS STARTING TO TAPER DOWN FROM DEFINITE
TO CHANCES DURING THE LAST 6 HOURS OF THE SHORT TERM FORECAST
PERIOD. FORECAST SOUNDINGS ARE SHOWING A FAST INTRUSION OF DRY AIR
IN THE MID AND UPPER LEVELS...SO EXPECT PRECIP RATES TO DIMINISH
QUICKLY BY DAWN. A LINGERING THUNDERSTORM WILL STILL BE A
POSSIBILITY...THOUGH IT SHOULD BE IN A WEAKENING/DYING STATE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 306 PM EST FRI JAN 2 2015
THE EXTENDED PERIOD BEGINS WARM AND WET ON SUNDAY MORNING JANUARY
THE FOURTH. A LARGE SWATH OF LIGHT TO MODERATE RAIN IS PROGGED TO
MOVE ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS ALONG AND JUST
AHEAD OF A VERY POTENT COLD FRONT. THE RAIN IS EXPECTED TO GRADUALLY
TAPER OFF FROM WEST TO EASTERN SUNDAY AND SUNDAY NIGHT AS THE FRONT
MOVES THROUGH. THE PRECIPITATION SHOULD BE OUT OF THE AREA BY LATE
SUNDAY NIGHT. AFTER THAT...A FRIGID ARCTIC AIR MASS IS EXPECTED TO
SETTLE OVER THE REGION FOR A FEW DAYS. AFTER A MODEST COOL DOWN
SUNDAY NIGHT...DURING WHICH TIME TEMPERATURES ARE EXPECTED TO DROP
INTO THE 20S ACROSS THE AREA...A SECOND REINFORCING SHOT OF COLD AIR
IS EXPECTED TO INVADE THE AREA TUESDAY NIGHT...AS A FAST MOVING
CLIPPER SYSTEM PASSES BY JUST TO OUR NORTH. BASED ON THE LATEST MOS
GUIDANCE AND MODEL SOUNDINGS...THE MERCURY COULD DROP INTO THE TEENS
AND LOW 20S TUESDAY NIGHT...AND PERHAPS EVEN INTO THE SINGLE DIGITS
WEDNESDAY NIGHT. THE CULPRIT OF THESE FRIGID TEMPERATURES WOULD COME
IN THE FORM OF A LARGE RIDGE OF ARCTIC HIGH PRESSURE THAT IS
EXPECTED TO SETTLE OVER THE EASTERN CONUS MID WEEK. AFTER SUNDAY AND
SUNDAY NIGHT...THE ONLY PRECIPITATION THAT MAY AFFECT THE AREA WOULD
COME TUESDAY AFTERNOON AND EVENING AS THE CLIPPER SYSTEM MOVES PAST.
ANY RAIN OR SNOW THAT FALLS THAT DAY WOULD LIKELY OCCUR NORTH OF THE
MOUNTAIN PARKWAY WITH LITTLE ACCUMULATION EXPECTED. THE REST OF THE
WEEK IS FORECAST TO BE DRY AND QUITE COLD. HIGHS ON WEDNESDAY AND
THURSDAY MAY NOT CLIMB OUT OF THE 20S. MONDAY LOOKS TO BE PRETTY
COLD AS WELL...WITH HIGHS IN THE 30S ANTICIPATED ON THAT DAY.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 642 PM EST FRI JAN 2 2015
SOUTH-SOUTHEAST FLOW AHEAD OF AN APPROACHING WARM FRONT WILL
STRENGTHEN TONIGHT AS IT PUSHES NORTHWARD. THIS WILL YIELD
DOWNSLOPING FLOW OFF THE HIGH TERRAIN ACROSS EASTERN KENTUCKY. THIS
SHOULD HELP KEEPING CIGS A BIT HIGHER THROUGH THE NIGHT. THE BEST
CHANCES FOR PERIODS OF MVFR CIGS WILL BE ACROSS SOUTH-CENTRAL
KENTUCKY...WHICH WILL BE LESS INFLUENCED BY THIS DOWNSLOPING FLOW.
WHILE A RAIN SHOWER MAY BE POSSIBLE OVERNIGHT...BEST RAIN CHANCES
SHOULD HOLD OFF UNTIL LATE. MAINLY VFR CONDITIONS SHOULD PREVAIL FOR
THE EASTERN TAF SITES. MAIN AVIATION CONCERN WILL BE DEVELOPING LLWS
LATE TONIGHT AND TOMORROW AS WINDS STRENGTHEN JUST OFF THE SURFACE TO
BETWEEN 40 AND 45 KNOTS. THIS WILL LIKELY PERSIST THROUGH THE DAY AS
THE INVERSION HOLDS TOUGH.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...KAS
SHORT TERM...JMW
LONG TERM...AR
AVIATION...KAS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
605 PM EST FRI JAN 2 2015
.SYNOPSIS...
HIGH PRESSURE WILL BUILD INTO THE AREA TONIGHT THROUGH SATURDAY.
LOW PRESSURE TRACKING NORTHWEST OF MAINE WILL DRAW A WARM FRONT
ACROSS THE REGION SUNDAY. A STRONG COLD FRONT WILL CROSS THE
REGION LATER SUNDAY NIGHT THROUGH EARLY MONDAY.
&&
.NEAR TERM /THROUGH SATURDAY/...
540 PM UPDATE: LATEST RADAR REF SHOWS THE LAST OF THE ST LAWRENCE
STREAMER SN SHWR BAND GRADUALLY WEAKENING OVR NE AROOSTOOK COUNTY
AS IT SLOWLY DROPS SWRD FROM THE ST JOHN RVR VLY. LATEST HRRR SIM
RADAR REF VALIDATES THIS WEAKENING TREND...DISSIPATING THIS BAND
SHORTLY AFT 00Z. WE XTNDED ISOLD SN SHWRS OVR NE AROOSTOOK COUNTY
FOR A COUPLE OF HRS LONGER INTO ERLY EVE...THEN MERGED WITH NEAR
ZERO POPS XPCTD BY 06Z...WITH COLDER...VERY DRY ARCTIC AIR
STARVING ST LAWRENCE MOISTURE THIS FAR DOWNWIND FROM THE THE
SEAWAY. OTHERWISE...FCST HRLY TEMPS INTO THE OVRNGT WERE ONLY
SLIGHTLY MODIFIED FROM THE LAST UPDATE...WITH 5 PM OBSVD TEMPS
PRETTY CLOSE TO THE PRIOR FCST FOR THIS HR.
ORGNL DISC: THE COLD FRONT CONTINUES TO MIGRATE ACROSS THE
FORECAST AREA THIS AFTERNOON AND SHOULD PUSH OFFSHORE BY THIS
EVENING. AS EXPECTED, THE SNOW SHOWERS AND SQUALLS HAVE PRETTY
MUCH COME TO AN END. THE EXCEPTION IS FAR NORTHERN MAINE WHERE THE
COLDER AIR FLOWING OVER THE OPEN WATERS OF THE SAINT LAWRENCE HAS
RESULTED IN SNOW STREAMERS. EVEN THIS ACTIVITY WILL COME TO AN END
THIS EVENING; THE AIR COMING IN BEHIND THE FRONT IS VERY DRY SO
MOISTURE WILL BE LIMITED.THE INCOMING AIRMASS IS ALSO VERY COLD,
SO WITH CLEARING SKIES AND LIGHT WINDS RADIATIONAL COOLING WILL BE
OPTIMIZED. NORTHERN MAINE WILL SEE LOWS OF -5F TO -15F WITH THE
USUAL COLD SPOTS IN THE FAR NORTHWEST APPROACHING -20F. SOUTHERN
REGIONS WILL BE -5F TO +5F, WITH THE COAST STAYING CLOSER TO +10F.
THE COLD CONTINUES TOMORROW AS HIGH PRESSURE CRESTS OVER THE
REGION. HIGHS WILL ONLY BE IN THE SINGLE DIGITS ABOVE ZERO OVER
THE NORTHERN HALF OF OUR FORECAST AREA, WHILE SOUTHERN AREAS WILL
BE 10 TO 20 ABOVE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY NIGHT/...
LOW PRESSURE LIFTING ACROSS THE GREAT LAKES WILL DRAW A WARM
FRONT TOWARD NEW ENGLAND SATURDAY NIGHT. CLOUD COVER WILL INCREASE
ACROSS THE REGION EARLY SATURDAY NIGHT. LOW TEMPERATURES SATURDAY
NIGHT WILL OCCUR EARLY THEN BEGIN TO RISE OVERNIGHT WITH THE
INCREASING CLOUDS. OVERRUNNING PRECIPITATION WILL THEN EXPAND
ACROSS THE FORECAST AREA LATER SATURDAY NIGHT. BASED ON CRITICAL
THICKNESSES...EXPECT PRECIPITATION TO REMAIN MOSTLY IN THE FORM OF
SNOW ACROSS THE FORECAST AREA SATURDAY NIGHT. HOWEVER...THE SNOW
COULD BEGIN TO TRANSITION TO A WINTRY MIX ACROSS DOWNEAST AREAS
LATE. THE PRIMARY GREAT LAKES LOW TRACKS NORTHWEST OF THE REGION
SUNDAY DRAWING THE WARM FRONT NORTH ACROSS THE REGION. MODELS
INDICATE THE POSSIBILITY THAT A WEAK SECONDARY LOW COULD DEVELOP
ALONG THE WARM FRONT AND MOVE ALONG THE COAST...THOUGH THE EXTENT
TO WHICH THE LOW DEVELOPS IS STILL UNCERTAIN. EXPECT A WINTRY MIX
TO TRANSITION TO MOSTLY RAIN ACROSS MUCH OF THE DOWNEAST AREA
SUNDAY AFTERNOON...WITH SNOW TRANSITIONING TO A WINTRY MIX ACROSS
NORTHERN AREAS. PRECIPITATION TYPES WILL BE DEPENDENT ON HOW
QUICKLY THE LOW LEVEL COLD AIR CAN BE ERODED. A STRONGER SECONDARY
LOW MOVING ALONG THE COAST WOULD HELP THE LOW LEVEL COLD AIR
REMAIN MORE PERSISTENT ACROSS INTERIOR DOWNEAST AREAS...WHILE A
WEAKER LOW WOULD ALLOW THE LOW LEVEL COLD AIR TO BE ERODED MORE
RAPIDLY. GENERALLY EXPECT STORM TOTAL SNOW ACCUMULATIONS OF 4 TO
7 INCHES ACROSS NORTHERN AREAS THROUGH SUNDAY WITH 3 TO 5 INCHES
DOWNEAST. SLEET AND ICE ACCUMULATIONS WILL BE DEPENDENT ON THE
TIMING OF THE TRANSITION FROM SNOW. GENERALLY EXPECT ICE
ACCUMULATIONS OF AROUND A TENTH OF AN INCH UP TO A QUARTER OF AN
INCH WILL BE POSSIBLE ACROSS THE FORECAST AREA. PRECIPITATION WILL
DECREASE LATER SUNDAY AFTERNOON INTO THE EVENING TAPERING TO RAIN
SHOWERS DOWNEAST WITH SNOW SHOWERS AND PATCHY FREEZING RAIN OR
FREEZING DRIZZLE ACROSS NORTHERN AND CENTRAL AREAS. A STRONG COLD
FRONT WILL CROSS THE REGION LATER SUNDAY NIGHT INTO MONDAY WITH A
CHANCE OF SNOW SHOWERS ACROSS MOSTLY THE NORTH AND MOUNTAINS. COLD
HIGH PRESSURE WILL BUILD EAST TOWARD THE REGION LATER MONDAY. HIGH
TEMPERATURES MONDAY WILL OCCUR DURING THE MORNING THEN FALL
THROUGH THE AFTERNOON. TEMPERATURES WILL BE AT ABOVE NORMAL LEVELS
SUNDAY WITH FALLING TEMPERATURES MONDAY.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
EXTREMELY COLD WEATHER MONDAY THROUGH LATE IN THE WEEK, IN WHAT
MAY END UP BEING OUR COLDEST SPELL OF THE SEASON, AND CERTAINLY
THE MOST NOTABLE COLD SPELL SO FAR. BITTERLY COLD AIRMASS WORKS
ITS WAY IN LATE MONDAY/MONDAY NIGHT. WITH A DECENT PRESSURE
GRADIENT REMAINING, COULD SEE SOME SERIOUSLY COLD WIND CHILLS
COLDER THAN 30 BELOW OVER THE NORTH. AMBIENT TEMPERATURES SHOULD
DROP TO 10 TO 20 BELOW OVER THE NORTH AND ZERO TO 10 BELOW
DOWNEAST.
AN EXTRAORDINARILY COLD DAY IN STORE TUESDAY AS ARCTIC HIGH
PRESSURE SETTLES OVERHEAD. HIGHS SHOULD STAY BELOW ZERO OVER ABOUT
THE NORTHERN HALF OF THE AREA. A WEAK SYSTEM MOVING IN FROM THE
WEST MAY BRING SOME LIGHT SNOW TUESDAY NIGHT AND/OR WEDNESDAY WITH
A MINOR MODERATION IN TEMPERATURES, BUT TEMPERATURES REMAINING
COLDER THAN AVERAGE.
AFTER THE WEAK POTENTIAL TUESDAY NIGHT/WEDNESDAY SYSTEM,
TEMPERATURES FALL YET AGAIN FOR WEDNESDAY NIGHT AND THURSDAY WITH
GENERALLY DRY CONDITIONS. ANOTHER WEAK SYSTEM IS POSSIBLE FRIDAY
WITH VERY SLIGHTLY MILDER TEMPERATURES.
MODELS ARE IN FAIRLY GOOD AGREEMENT THROUGH THE EXTENDED. MINOR
DIFFERENCES EXIST IN THE TIMING OF THE WEAK SYSTEMS, BUT NOTHING
MAJOR. ALL MODELS AGREE IT WILL BE VERY COLD.
&&
.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
NEAR TERM: VFR CONDITIONS ARE EXPECTED TONIGHT AND SATURDAY AS
HIGH PRESSURE DOMINATES THE REGION`S WEATHER.
SHORT TERM: VFR CONDITIONS ARE EXPECTED ACROSS THE REGION
SATURDAY EVENING. CONDITIONS WILL THEN LOWER TO IFR/LIFR LEVELS
SATURDAY NIGHT WITH SIMILAR CONDITIONS PERSISTING INTO EARLY
SUNDAY NIGHT. CONDITIONS WILL IMPROVE TO MVFR/VFR LEVELS ACROSS
NORTHERN AREAS LATER SUNDAY NIGHT...WITH VFR CONDITIONS DEVELOPING
DOWNEAST. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS THE
NORTH AND MOUNTAINS MONDAY. OTHERWISE... GENERALLY VFR CONDITIONS
ARE EXPECTED ACROSS THE REGION MONDAY INTO TUESDAY. CONDITIONS
WILL THEN LOWER TO IFR/LIFR LEVELS LATER TUESDAY NIGHT...WITH
SIMILAR CONDITIONS PERSISTING INTO WEDNESDAY.
&&
.MARINE...
NEAR TERM: THE SMALL CRAFT ADVISORY REMAINS IN EFFECT THROUGH
TONIGHT. A COLD FRONT WILL CROSS THE WATERS THIS EVENING, AND COLD
AIR ADVECTION WILL ALLOW FOR GOOD MIXING OVER THE RELATIVELY
WARMER GULF OF MAINE. THEREFORE, WINDS OF 15 TO 25 KT WITH GUSTS
TO AROUND 30 KT WILL CONTINUE OVERNIGHT BEFORE LESSENING EARLY
SATURDAY MORNING.
SHORT TERM: CONDITIONS WILL BE BELOW SMALL CRAFT ADVISORY LEVELS
EARLY SATURDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS WILL THEN
DEVELOP LATER SATURDAY NIGHT. STRONG SMALL CRAFT ADVISORY...OR
POSSIBLY GALE CONDITIONS...WILL OCCUR SUNDAY INTO SUNDAY NIGHT.
GALE CONDITIONS ARE EXPECTED MONDAY. VISIBILITIES WILL LOWER IN
DEVELOPING SNOW AND MIXED PRECIPITATION SATURDAY NIGHT...WITH
MIXED PRECIPITATION CHANGING TO RAIN SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORCROSS
LONG TERM...FOISY
AVIATION...VJN/NORCROSS
MARINE...VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
555 PM EST THU JAN 1 2015
.SYNOPSIS...
AN ARCTIC FRONT WILL SWEEP NORTHWEST TO SOUTHEAST THROUGH THE
REGION LATE TONIGHT INTO FRIDAY. HIGH PRESSURE WILL BUILD ACROSS
THE REGION FRIDAY NIGHT THROUGH SATURDAY. LOW PRESSURE TRACKING
NORTHWEST OF MAINE WILL ALLOW A WARM FRONT TO APPROACH THE REGION
SUNDAY.
&&
.NEAR TERM /THROUGH FRIDAY/...
530 PM UPDATE: MOST OF THIS UPDATE WAS MADE ON REFINING POPS BASED
ON FCST LIQ EQUIV POPS ACROSS THE NW TWO THIRDS OF THE FA. THIS
WAS DONE USING THE LATEST HRLY UPDATED HRRR SIM RADAR REF
OUTPUT...WHICH SHOWS MOST OF THE SN SHWR ACTIVITY XPCTD OVR THE NW
AND FAR NRN PTNS OF THE FA THIS EVE...WITH THIS BAND SLOWLY MOVG
SE LATE TNGT INTO NE PTNS OF THE FA...BEFORE BECOMING LESS
ORGANIZED BY DAYBREAK FRI. WITH THE ACTUAL ARCTIC FRONT XPCTD TO
REMAIN NW OF THE WRN ME/QB BORDER MSLY PRIOR TO 06Z...MOST OF THE
INITIAL SN SHWR ACTIVITY WILL BE FRONTOGENETICALLY FORCED...WITH
ANY LCLY ENHANCED BANDING OF SN RATES MSLY AFT 06Z ALG THE LEADING
EDGE OF THE ARCTIC FRONT AS IT CROSSES THRU NW AND EVENTUALLY NE
ME VERY LATE TNGT. NOT SURE WHETHER THIS BANDING WILL BE INTENSE
ENOUGH TO QUALIFY AS SN SQLS DURG THIS TM OF NGT WHEN SFC-1000M
LAPSE RATES ARE MORE STABLE THAN LATE MORN INTO AFTN...BUT CANNOT
COMPLETELY RULE SN SQL ACTIVITY ATTM. OTHERWISE...MODIFICATIONS
WERE MADE TO CLD CVR AND FCST HRLY TEMPS OVRNGT INTO FRI BASED ON
5 PM SAT IMAGERY AND SFC OBS.
ORGNL DISC: MAIN CONCERN OVERNIGHT CONTINUES TO BE THE POTENTIAL
FOR SNOW SQUALLS LATE MSLY ACROSS NW AND FAR N PTNS OF THE FA.
LOW PRESSURE CURRENTLY CROSSING HUDSON BAY WILL CONTINUE ITS
EASTWARD TREK TONIGHT, DRAGGING ITS ATTENDANT COLD FRONT ALONG
SOUTHERN CANADA/NORTHERN UNITED STATES AS IT DOES SO. THIS FRONT
WILL PUSH INTO NORTHERN MAINE LATE THIS EVENING AND EVENTUALLY MOVE
OFF THE MAINE COAST FRIDAY MORNING. THIS IS A POTENT ARCTIC FRONT
AND WILL SERVE TO DO TWO THINGS. ONE, IT WILL RETURN COLDER AIR TO
THE REGION, AND TWO, IT WILL ALSO SERVE AS A FOCUS FOR SNOW SHOWER
ACTIVITY, ESPECIALLY OVER NORTHERN MAINE. GOOD MOISTURE CONVERGENCE
ALONG THE FRONT, ALONG WITH STEEPENING LAPSE RATES AND PLENTIFUL
LIFT, A BAND OF SNOW SQUALLS WILL BE POSSIBLE, ESPECIALLY OVER THE
SAINT JOHN VALLEY. ANY SQUALLS WILL BE CAPABLE OF PRODUCING
VISIBILITY OF A HALF MILE OR LESS, GUSTY WINDS, AND A QUICK INCH OR
TWO OF SNOW. OUTSIDE OF ANY SQUALLS, EXPECT JUST SCATTERED SNOW
SHOWERS WITH LIGHT ACCUMULATION. TEMPERATURES WILL DROP OFF QUICKLY
BEHIND THE FRONT, WITH OVERNIGHT LOWS RETURNING INTO THE SINGLE
DIGITS ACROSS THE NORTHERN PORTIONS OF THE COUNTY. ELSEWHERE,
TEMPERATURES WILL BE IN THE TEENS TO MID 20S.
FOR FRIDAY...THE AFOREMENTIONED FRONT WILL FINISH ITS SOUTHWARD PUSH
AND WILL BE OFFSHORE BY AFTERNOON. AS SUCH, THE BULK OF THE SNOW
SHOWERS WILL COME TO AN END WITH JUST A FEW LINGERING SNOW FLAKES
POSSIBLE OVER NORTHERN MAINE. HIGHS WILL BE CHILLY IN THE
NORTH...10 TO 15 DEGREES...BUT CENTRAL AND SOUTHERN MAINE WILL BE A
BIT BETTER, TOPPING OUT IN THE 20S TO AROUND 30.
&&
.SHORT TERM /FRIDAY NIGHT THROUGH SUNDAY/...
COULD HAVE A SLIGHT CHANCE OF SNOW SHOWERS ACROSS THE
NORTH/MOUNTAINS EARLY FRIDAY NIGHT. OTHERWISE...HIGH PRESSURE
BUILDS EAST TOWARD THE REGION FRIDAY NIGHT WITH DECREASING CLOUDS
NORTH AND MOSTLY CLEAR SKIES DOWNEAST. HIGH PRESSURE THEN CROSSES
THE REGION SATURDAY WITH PARTLY/MOSTLY SUNNY SKIES. LOW PRESSURE
LIFTING ACROSS THE GREAT LAKES WILL DRAW A WARM FRONT TOWARD NEW
ENGLAND SATURDAY NIGHT. CLOUD COVER WILL INCREASE ACROSS THE
REGION EARLY SATURDAY NIGHT. LOW TEMPERATURES SATURDAY NIGHT WILL
OCCUR EARLY THEN BEGIN TO RISE OVERNIGHT WITH THE INCREASING
CLOUDS. OVERRUNNING PRECIPITATION WILL THEN EXPAND ACROSS THE
FORECAST AREA LATER SATURDAY NIGHT. BASED ON CRITICAL
THICKNESSES...EXPECT PRECIPITATION TO REMAIN MOSTLY IN THE FORM OF
SNOW ACROSS THE FORECAST AREA SATURDAY NIGHT. HOWEVER...THE SNOW
COULD BEGIN TO TRANSITION TO A WINTRY MIX ACROSS DOWNEAST AREAS
LATE. THE PRIMARY GREAT LAKES LOW TRACKS NORTHWEST OF THE REGION
SUNDAY DRAWING THE WARM FRONT NORTH ACROSS THE REGION. MODELS
INDICATE THE POSSIBILITY THAT A WEAK SECONDARY LOW COULD DEVELOP
ALONG THE WARM FRONT AND MOVE ALONG THE COAST...THOUGH THE EXTENT
TO WHICH THE LOW DEVELOPS IS UNCERTAIN. EXPECT A WINTRY MIX TO
TRANSITION TO MOSTLY RAIN ACROSS MUCH OF THE DOWNEAST AREA SUNDAY
AFTERNOON...WITH SNOW TRANSITIONING TO A WINTRY MIX ACROSS
NORTHERN AREAS. PRECIPITATION TYPES WILL BE DEPENDENT ON HOW
QUICKLY THE LOW LEVEL COLD AIR CAN BE ERODED. A STRONGER SECONDARY
LOW MOVING ALONG THE COAST WOULD HELP THE LOW LEVEL COLD AIR
REMAIN MORE PERSISTENT ACROSS INTERIOR DOWNEAST AREAS...WHILE A
WEAKER LOW WOULD ALLOW THE LOW LEVEL COLD AIR TO BE ERODED MORE
RAPIDLY. GENERALLY EXPECT STORM TOTAL SNOW ACCUMULATION OF 4 TO 7
INCHES ACROSS NORTHERN AREAS THROUGH SUNDAY WITH 3 TO 5 INCHES
DOWNEAST. SLEET AND ICE ACCUMULATIONS WILL BE DEPENDENT ON THE
TIMING OF THE TRANSITION FROM SNOW WHICH IS STILL UNCERTAIN AT
THIS TIME. TEMPERATURES WILL BE AT BELOW NORMAL LEVELS
SATURDAY...THEN AT ABOVE NORMAL LEVELS SUNDAY DEPENDENT ON THE
EXTENT OF LOW LEVEL WARMING.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
LATEST RUN OF GFS/ECMWF IN GOOD AGREEMENT TRACKING LOW PRESSURE
NORTH OF CWA THROUGH MONDAY WITH STRONG NORTHWEST TO NORTH
GRADIENT ESTABLISHING FOR GUSTY WINDS AND A RAPID DECREASE IN
TEMPERATURES. SNOW SHOWER ACTIVITY...OR MIXED PRECIPITATION ALONG
DOWNEAST...WILL DIMINISH QUICKLY ACROSS THE AREA BY MONDAY NIGHT.
ANOTHER LOW APPROACHES FROM THE GREAT LAKES ON TUESDAY BUT CURRENT
GUIDANCE KEEPS THE SYSTEM OFFSHORE RESULTING IN CHANCE POPS ALONG
DOWNEAST COAST AND SLIGHT CHANCE TO CENTRAL AREAS THROUGH EARLY
THURSDAY. HIGH PRESSURE THEN BUILDS IN FROM THE WEST ON THURSDAY
FOR A BRIEF RESPITE BEFORE A CLIPPER SYSTEM APPROACHES AGAIN FROM
THE WEST. TEMPERATURES THROUGH THE WEEK WILL REMAIN WELL BELOW
NORMALS.
&&
.AVIATION /00Z FRIDAY THROUGH TUESDAY/...
NEAR TERM: VFR CONDITIONS WILL PREVAIL AT THE SOUTHERN TERMINALS
THROUGH THE PERIOD. HOWEVER, AT KCAR/KFVE/KPQI, A COLD FRONTAL
PASSAGE WILL BRING SNOW SHOWERS AND PERHAPS EVEN SNOW SQUALLS.
PREVAILING MVFR CONDITIONS ARE EXPECTED 22Z THU THRU 12Z FRIDAY,
WITH IFR/LIFR POSSIBLE IN ANY SNOW. CONDITIONS WILL IMPROVE
THROUGH THE DAY FRIDAY WITH LIFTING CEILINGS AND DECREASING
COVERAGE OF SNOW SHOWERS.
SHORT TERM: COULD HAVE LOCALIZED MVFR CONDITIONS ACROSS THE
NORTH AND MOUNTAINS EARLY FRIDAY NIGHT. OTHERWISE...VFR
CONDITIONS ARE EXPECTED ACROSS THE REGION FRIDAY NIGHT INTO EARLY
SATURDAY NIGHT. CONDITIONS WILL LOWER TO IFR/LIFR LEVELS LATER
SATURDAY NIGHT WITH SIMILAR CONDITIONS PERSISTING INTO EARLY
SUNDAY NIGHT. CONDITIONS WILL IMPROVE TO MVFR/VFR LEVELS ACROSS
NORTHERN AREAS LATER SUNDAY NIGHT...WITH VFR CONDITIONS DEVELOPING
DOWNEAST. OCCASIONAL MVFR CONDITIONS COULD PERSIST ACROSS THE
NORTH AND MOUNTAINS MONDAY. OTHERWISE...VFR CONDITIONS ARE
EXPECTED ACROSS THE REGION MONDAY INTO TUESDAY.
&&
.MARINE...
NEAR TERM: A SMALL CRAFT ADVISORY REMAINS IN EFFECT FOR TONIGHT,
BUT IT HAS BEEN EXTENDED THROUGH FRIDAY. WINDS WILL INCREASE AHEAD
OF AN APPROACHING COLD FRONT TONIGHT, AND THEN SWITCH TO THE
WEST/NORTHWEST FRIDAY AS THE FRONT CROSSES THE GULF OF MAINE.
WINDS OF 15 TO 20 KT WITH GUSTS TO 30 KT ARE EXPECTED THROUGH THE
PERIOD.
SHORT TERM: SMALL CRAFT ADVISORY CONDITIONS WILL OCCUR FRIDAY
NIGHT INTO EARLY SATURDAY. CONDITIONS WILL BRIEFLY FALL BELOW
SMALL CRAFT ADVISORY LEVELS SATURDAY AFTERNOON INTO EARLY
SATURDAY NIGHT. SMALL CRAFT ADVISORY CONDITIONS WILL DEVELOP AGAIN
LATER SATURDAY NIGHT. STRONG SMALL CRAFT ADVISORY...OR POSSIBLY
GALE CONDITIONS...WILL OCCUR SUNDAY. VISIBILITIES WILL LOWER IN
DEVELOPING SNOW AND MIXED PRECIPITATION LATER SATURDAY
NIGHT...WITH MIXED PRECIPITATION CHANGING TO RAIN SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 AM EST SATURDAY FOR ANZ050>052.
&&
$$
NEAR TERM...VJN
SHORT TERM...NORCROSS
LONG TERM...PJR
AVIATION...VJN/NORCROSS
MARINE...VJN/NORCROSS
AREA FORECAST DISCUSSION
NWS CARIBOU ME
715 AM EST THU JAN 1 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS THE REGION TODAY. AN ARCTIC FRONT
WILL SWEEP THROUGH THE REGION LATER TONIGHT INTO FRIDAY. HIGH
PRESSURE WILL BUILD INTO THE REGION FROM CANADA FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
715 AM UPDATE...ADJUSTED THE HRLY TEMPERATURES AND SKY CONDITIONS
TO MATCH THE LATEST OBS.11Z SURFACE ANALYSIS SHOWED THE WARM FRONT
LIFTING NORTH W/HINTS OF A WEAK LOW DEVELOPING THE FRONT ALONG THE
HANCOCK-WASHINGTON COUNTY COAST. POPS WERE PUSHED FURTHER EAST TO
ACCOUNT FOR SOME LIGHT SNOW THIS MORNING AS THE RADAR WAS SHOWING
SOME LIGHT RETURNS. NO OTHER CHANGES ATTM.
LATEST SURFACE ANALYSIS SHOWED WARM FRONT LIFTING N ACROSS THE
PINE TREE STATE. SOME LIGHT PRECIP IN THE FORM OF SOME LIGHT SNOW
ACROSS THE IMMEDIATE COAST W/MOST OF PRECIP OFFSHORE. FURTHER N,
THE RADAR SHOWED SOME VERY LIGHT RETURNS IN THE FORM OF SOME
FLURRIES. TEMPERATURES WERE SLOWLY RISING THIS MORNING AND WILL
CONTINUE TO DO SO TODAY W/THE WARM FRONT PASSAGE. PERIODS OF LIGHT
SNOW/SNOW SHOWERS EXPECTED ACROSS THE NORTH AND WEST AND RIGHT
ALONG THE DOWNEAST COAST. THE NAM AND RAP GUIDANCE POINT TO SOME
STEEPENING LAPSE RATES OF 7.0C/KM FROM 850-700MBS W/THE WARM
FRONT. THE BEST CHANCE FOR ANY ACCUMULATING SNOW WILL BE ACROSS
THE FAR W AND NW W/AN INCH POSSIBLE. TEMPERATURES ARE EXPECTED TO
THE UPPER TEENS AND LOWER FOR THE NORTHERN 1/2 OF THE CWA AND
MID/UPPER 20S CENTRAL TO THE DOWNEAST REGION.
THINGS GET EVEN MORE INTERESTING THIS EVENING AND OVERNIGHT W/THE
ARCTIC FRONT EXPECTED TO MOVE ACROSS THE REGION. BOTH THE NAM AND
GFS SOUNDINGS SHOW DEEP MOISTURE THROUGH 700MBS W/ANOTHER ROUND OF
STEEP LAPSE RATES AOA 7.0C/KM IN THE 850-700MB LAYER. DECENT SHEAR
OF 30KTS IN THE 0-3KM LAYER. BTV SNOW SQUALL PARAMETER SHOWS A
STRONG SIGNAL SUPPORTING THE POTENTIAL FOR SNOW SQUALLS WHICH
COULD DUMP A QUICK INCH OF SNOW W/GUSTY WINDS AND VSBYS BLO 1/2SM.
STAYED W/THE DAYCREW`S ASSESSMENT OF 60% POPS ACROSS THE NORTHERN
1/2 OF THE CWA INTO TONIGHT AS THE ARCTIC FRONT SLIDES ACROSS THE
REGION. TEMPERATURES WILL DROP OFF, BUT NOT UNTIL AFTER 09Z.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE COLD FRONT WILL SWEEP EAST ON FRIDAY AS HIGH PRESSURE BEGINS TO
BUILD IN FROM CENTRAL CANADA. WE COULD SEE A FEW MORNING SNOW
SHOWERS OTHERWISE PARTLY TO MOSTLY CLOUDY SKIES CAN BE EXPECTED
ACROSS THE REGION ON FRIDAY. HIGHS ON FRIDAY WILL RANGE FROM 10 TO
15 ABOVE NORTH AND MID 20S DOWN EAST.
MAINLY CLEAR AND VERY COLD WEATHER CAN BE EXPECTED FOR FRIDAY NIGHT. LOWS
WILL RANGE FROM 10 TO 15 BELOW ACROSS TEH NORTH AND ZERO TO 10
ABOVE DOWNEAST.
MOSTLY SUNNY SKIES CAN BE EXPECTED ON SATURDAY BEFORE WE SEE
INCREASING HIGH CLOUDS SATURADY AFTERNOON. HIGHS ON SATURDAY WILL
RANGE FROM THE SINGLE DIGITS ABOVE ZERO NORTH AND MID TEENS TO
NEAR 20S DOWN EAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CLOUDS INCREASE SATURDAY EVENING WITH SNOW DEVELOPING AFTER
MIDNIGHT. THE LATEST GFS/ECMWF TRACK LOW PRESSURE OFF TO OUR
NORTHWEST DURING SATURDAY NIGHT AND SUNDAY AS WEAK LOW PRESSURE
DEVELOPS ALONG THE DOWN EAST COAST. APPEARS AS IF THE LOW TRACKING
OFF TO OUR NORTHWEST WILL REMAIN THE PRIMARY LOW ALLOWING WARMER
AIR TO CHANGE PRECIPITATION TO A MIX OR ALL RAIN ACROSS DOWNEAST
AND CENTRAL AREAS DURING SUNDAY. AT THIS TIME LOOKS LIKE THIS
SYSTEM WILL BE AN ADVISORY LEVEL EVENT. PRECIPITATION WILL START
TO WIND DOWN SUNDAY NIGHT AS THE LOW MOVES AWAY FROM THE REGION.
VERY COLD AIR WILL BEGIN TO POUR INTO THE REGION DURING MONDAY
WITH HIGHS OCCURRING EARLY IN THE DAY. VERY COLD AND DRY WEATHER
FOR MONDAY NIGHT AND TUEDSAY. A CLIPPER TYPE LOW MAY BRING SOME
SNOW TO ESPECIALLY DOWN EAST AREAS TUESDAY NIGHT AND WEDNESDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR EXPECTED W/TEH EXCEPTION OF THE NORTHERN TERMINALS
ESPECIALLY KCAR AND KFVE AS MVFR CONDITIONS ARE POSSIBLE LATER
THIS AFTERNOON INTO TONIGHT IN SNOW SHOWERS/SQUALLS.
SHORT TERM: IFR IN PRECIPITATION SATURDAY NIGHT THROUGH SUNDAY
NIGHT. OTHERWISE VFR FRIDAY AND MONDAY.
&&
.MARINE...
NEAR TERM: THE SCA WILL STAY UP THROUGH TONIGHT W/WINDS INCREASING
TO 20-25 KTS BY TONIGHT. THE OUTER ZONES COULD SEE GUSTS TO 30 KTS
AS A LLVL JET OF 45 KTS MOVES OVER THE WATERS AHEAD OF THE APCHG
ARCTIC FRONT. SEAS WILL RESPOND ACCORDINGLY BUILDING TO 6-8 FT BY
TONIGHT.
SHORT TERM:SMALL CRAFT ADVISORY LEVEL CONDITIONS ARE EXPECTED
FRIDAY AND FRIDAY NIGHT. CONDITIONS SHOULD THEN DECREASE BELOW
SMALL CRAFT ADVISORY LEVELS SATURDAY WITH CONDITIONS ONCE AGAIN
INCREASING TO SCA LEVELS SATURDAY NIGHT AND SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS CARIBOU ME
518 AM EST THU JAN 1 2015
.SYNOPSIS...
A WARM FRONT WILL LIFT ACROSS THE REGION TODAY. AN ARCTIC FRONT
WILL SWEEP THROUGH THE REGION LATER TONIGHT INTO FRIDAY. HIGH
PRESSURE WILL BUILD INTO THE REGION FROM CANADA FRIDAY NIGHT INTO
SATURDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATEST SURFACE ANALYSIS SHOWED WARM FRONT LIFTING N ACROSS THE
PINE TREE STATE. SOME LIGHT PRECIP IN THE FORM OF SOME LIGHT SNOW
ACROSS THE IMMEDIATE COAST W/MOST OF PRECIP OFFSHORE. FURTHER N,
THE RADAR SHOWED SOME VERY LIGHT RETURNS IN THE FORM OF SOME
FLURRIES. TEMPERATURES WERE SLOWLY RISING THIS MORNING AND WILL
CONTINUE TO DO SO TODAY W/THE WARM FRONT PASSAGE. PERIODS OF LIGHT
SNOW/SNOW SHOWERS EXPECTED ACROSS THE NORTH AND WEST AND RIGHT
ALONG THE DOWNEAST COAST. THE NAM AND RAP GUIDANCE POINT TO SOME
STEEPENING LAPSE RATES OF 7.0C/KM FROM 850-700MBS W/THE WARM
FRONT. THE BEST CHANCE FOR ANY ACCUMULATING SNOW WILL BE ACROSS
THE FAR W AND NW W/AN INCH POSSIBLE. TEMPERATURES ARE EXPECTED TO
THE UPPER TEENS AND LOWER FOR THE NORTHERN 1/2 OF THE CWA AND
MID/UPPER 20S CENTRAL TO THE DOWNEAST REGION.
THINGS GET EVEN MORE INTERESTING THIS EVENING AND OVERNIGHT W/THE
ARCTIC FRONT EXPECTED TO MOVE ACROSS THE REGION. BOTH THE NAM AND
GFS SOUNDINGS SHOW DEEP MOISTURE THROUGH 700MBS W/ANOTHER ROUND OF
STEEP LAPSE RATES AOA 7.0C/KM IN THE 850-700MB LAYER. DECENT SHEAR
OF 30KTS IN THE 0-3KM LAYER. BTV SNOW SQUALL PARAMETER SHOWS A
STRONG SIGNAL SUPPORTING THE POTENTIAL FOR SNOW SQUALLS WHICH
COULD DUMP A QUICK INCH OF SNOW W/GUSTY WINDS AND VSBYS BLO 1/2SM.
STAYED W/THE DAYCREW`S ASSESSMENT OF 60% POPS ACROSS THE NORTHERN
1/2 OF THE CWA INTO TONIGHT AS THE ARCTIC FRONT SLIDES ACROSS THE
REGION. TEMPERATURES WILL DROP OFF, BUT NOT UNTIL AFTER 09Z.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY/...
THE COLD FRONT WILL SWEEP EAST ON FRIDAY AS HIGH PRESSURE BEGINS TO
BUILD IN FROM CENTRAL CANADA. WE COULD SEE A FEW MORNING SNOW
SHOWERS OTHERWISE PARTLY TO MOSTLY CLOUDY SKIES CAN BE EXPECTED
ACROSS THE REGION ON FRIDAY. HIGHS ON FRIDAY WILL RANGE FROM 10 TO
15 ABOVE NORTH AND MID 20S DOWN EAST.
MAINLY CLEAR AND VERY COLD WEATHER CAN BE EXPECTED FOR FRIDAY NIGHT. LOWS
WILL RANGE FROM 10 TO 15 BELOW ACROSS TEH NORTH AND ZERO TO 10
ABOVE DOWNEAST.
MOSTLY SUNNY SKIES CAN BE EXPECTED ON SATURDAY BEFORE WE SEE
INCREASING HIGH CLOUDS SATURADY AFTERNOON. HIGHS ON SATURDAY WILL
RANGE FROM THE SINGLE DIGITS ABOVE ZERO NORTH AND MID TEENS TO
NEAR 20S DOWN EAST.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
CLOUDS INCREASE SATURDAY EVENING WITH SNOW DEVELOPING AFTER
MIDNIGHT. THE LATEST GFS/ECMWF TRACK LOW PRESSURE OFF TO OUR
NORTHWEST DURING SATURDAY NIGHT AND SUNDAY AS WEAK LOW PRESSURE
DEVELOPS ALONG THE DOWN EAST COAST. APPEARS AS IF THE LOW TRACKING
OFF TO OUR NORTHWEST WILL REMAIN THE PRIMARY LOW ALLOWING WARMER
AIR TO CHANGE PRECIPITATION TO A MIX OR ALL RAIN ACROSS DOWNEAST
AND CENTRAL AREAS DURING SUNDAY. AT THIS TIME LOOKS LIKE THIS
SYSTEM WILL BE AN ADVISORY LEVEL EVENT. PRECIPITATION WILL START
TO WIND DOWN SUNDAY NIGHT AS THE LOW MOVES AWAY FROM THE REGION.
VERY COLD AIR WILL BEGIN TO POUR INTO THE REGION DURING MONDAY
WITH HIGHS OCCURRING EARLY IN THE DAY. VERY COLD AND DRY WEATHER
FOR MONDAY NIGHT AND TUEDSAY. A CLIPPER TYPE LOW MAY BRING SOME
SNOW TO ESPECIALLY DOWN EAST AREAS TUESDAY NIGHT AND WEDNESDAY.
&&
.AVIATION /09Z THURSDAY THROUGH MONDAY/...
NEAR TERM: VFR EXPECTED W/TEH EXCEPTION OF THE NORTHERN TERMINALS
ESPECIALLY KCAR AND KFVE AS MVFR CONDITIONS ARE POSSIBLE LATER
THIS AFTERNOON INTO TONIGHT IN SNOW SHOWERS/SQUALLS.
SHORT TERM: IFR IN PRECIPITATION SATURDAY NIGHT THROUGH SUNDAY
NIGHT. OTHERWISE VFR FRIDAY AND MONDAY.
&&
.MARINE...
NEAR TERM: THE SCA WILL STAY UP THROUGH TONIGHT W/WINDS INCREASING
TO 20-25 KTS BY TONIGHT. THE OUTER ZONES COULD SEE GUSTS TO 30 KTS
AS A LLVL JET OF 45 KTS MOVES OVER THE WATERS AHEAD OF THE APCHG
ARCTIC FRONT. SEAS WILL RESPOND ACCORDINGLY BUILDING TO 6-8 FT BY
TONIGHT.
SHORT TERM:SMALL CRAFT ADVISORY LEVEL CONDITIONS ARE EXPECTED
FRIDAY AND FRIDAY NIGHT. CONDITIONS SHOULD THEN DECREASE BELOW
SMALL CRAFT ADVISORY LEVELS SATURDAY WITH CONDITIONS ONCE AGAIN
INCREASING TO SCA LEVELS SATURDAY NIGHT AND SUNDAY.
&&
.CAR WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 4 AM EST FRIDAY FOR ANZ050>052.
&&
$$
NEAR TERM...HEWITT
SHORT TERM...DUDA
LONG TERM...DUDA
AVIATION...HEWITT/DUDA
MARINE...HEWITT/DUDA
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
744 PM EST FRI JAN 2 2015
.SYNOPSIS...
A STORM SYSTEM WILL BRING A BRIEF WINTRY MIX EARLY SATURDAY FOLLOWED
BY RAIN THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH SATURDAY NIGHT/...
NO WHOLE-SALE CHANGES MADE TO THE OVERALL FORECAST AS PROGRESSION OF
THE SYSTEM AND FZRA THREAT REMAINS ON TRACK. SOME OF THE NOTEWORTHY
UPDATES INCLUDE CUTTING BACK ON SKY IN THE VERY NEAR TERM AS THE
THICKER CLOUD COVER TO OUR SOUTH HAS STALLED OVER WV...LEAVING ONLY
THIN HIGH CLOUDS STREAMING THROUGH THE FORECAST AREA. LESS CLOUDS
HAS RESULTED IN A GENERAL LOWERING OF INITIAL TEMPS NOW THROUGH
ABOUT 06Z AS THE THIN VEIL OF HIGH CLOUDS HAS NOT BEEN ENOUGH TO
QUELL THE ONSET OF RADIATIONAL COOLING. TEMPS ARE DOWN A FEW DEGREES
ACROSS THE BOARD FROM EARLIER PROJECTIONS...HOWEVER BACKING WINDS
OVER THE NEXT SEVERAL HOURS WILL BEGIN TO RAPIDLY ADVANCE THE CLOUDS
AND WARMER LLVL TEMPS INTO OUR CWA.
THE WARM FRONT WILL SPREAD PRECIPITATION FROM S TO N ACROSS THE
FORECAST AREA TONIGHT FOCUSED PRIMARILY ACROSS THE HIGHER ELEVATIONS
OF THE SE FIRST AND THEN ALONG A STRONGER WAVE THROUGH ERN OH/WRN PA
BY SAT MORNING. LOCAL HI-RES MODEL AND HRRR HAVE PRETTY GOOD HANDLE
ON SFC TEMPS THROUGH MID-MORNING SAT...HIGHLIGHTING BOTH THE WARMING
WEST OF THE RIDGES WITH THE DOWNSLOPING AND THE COLD AIR DAMMED UP
AGAINST THE ERN SLOPES OF THE RIDGES. BLENDED PREVIOUS FORECAST THAT
SIDED HEAVILY TOWARDS NAM TEMPS WITH THESE HI-RES OPTIONS...WHILE
MAKING THE NECESSARY TERRAIN ALTERATIONS NECESSARY FOR THE ERLY LLVL
FLOW SET UP. AGAIN...THIS GENERALLY KEEPS THE PREVIOUS FORECAST
GOING...BUT PROVIDES A FEW TWEAKS TRIMMING BACK FZRA POTENTIAL FROM
PIT TO JUST WEST OF THE RIDGES. ALSO HELD IN THE FZRA A LITTLE
LONGER BETWEEN THE LAUREL AND CHESTNUT RIDGES AND ERN GARRETT COUNTY
MARYLAND TO ACCOUNT FOR POOR SCOURING OF THE COLD AIR. A FEW MORE
HOURS WITH FZRA COULD MEAN PORTIONS OF GARRETT CO. COULD PUSH CLOSE
TO THE 1/4" ICE THRESHOLD REQUIRING AN ICE STORM WARNING...BUT MOST
GUIDANCE KEEPS THE HIGHER AMOUNTS OF QPF MUCH CLOSER TO THE SFC LOW
TRACKING THROUGH OHIO. DRIER AIR IN THE WARM SECTOR OF THE SYSTEM
COULD LIMIT OVERALL OUTPUT OVER THE HIGH TERRAIN. WITH FAIRLY LOW
CONFIDENCE OF EXCEEDANCE...WILL HOLD STEADY WITH CURRENT ADVISORIES.
TAX
&&
.SHORT TERM /SUNDAY/...
THE BULK OF THE RAINFALL WILL HAVE MOVED EAST OF THE FORECAST AREA
BY SUNDAY MORNING AS A COLD FRONT CROSSES THE REGION. CHANCES FOR
RAIN WILL DIMINISH THROUGH THE MORNING...WITH A BRIEF LULL IN
PRECIPITATION SUNDAY AFTERNOON BEFORE THE NEXT WAVE APPROACHES FROM
THE WEST. THE DIURNAL TEMPERATURE CYCLE WILL CONTINUE TO BE
OFFSET...WITH TEMPERATURES FALLING THROUGH THE DAY ON SUNDAY. WINDS
WILL ALSO PICK UP BEHIND THE FRONT...WITH GUSTS OVER 25 MPH AND
GUSTING UP TO 35-40 MPH IN THE HIGHEST ELEVATIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
MUCH COLDER SUNDAY NIGHT AND MONDAY AS 850MB TEMPS WILL
RANGE FROM -16C TO -20C BY LATE DAY MONDAY WITH SCATTERED SNOW
SHOWERS MAINLY RIDGES AND I-80 CORRIDOR. LOW INVERSION HEIGHTS AND
WESTERLY FLOW WILL LIMIT ANY ACCUMULATIONS.
INDIVIDUAL DISTURBANCES ARE PROGGED TO ADVN THRU THE BASE OF
PERSISTENT ERN CONUS TROFG THRU THE PD WITH PERIODIC CHCS FOR SNW
SHWRS. THE STRONGEST WAVE IS PROGGED FOR A TUE PASSAGE. TEMPS ARND
10 DEG BLO AVG ARE EXPD TO START...WITH READINGS 15 TO 20 DEG BLO
AVG AFT THE TUE SHRTWV PASSAGE.
&&
.AVIATION /01Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS WILL CONTINUE THROUGH THE EVENING BEFORE QUICKLY
DROPPING TO MVFR THEN IFR FROM SOUTH TO NORTH EARLY IN THE
MORNING. TAF SITES UP NORTH MAY BRIEFLY SEE SLEET INITIALLY...BUT
MOST SITES WILL START AS AN HOUR OR TWO OF FZRA. THIS WILL
TRANSITION TO PLAIN RA DURING THE MORNING EXCEPT AT THE NORTHERN
SITES.. KFKL AND KDUJ WILL BE LAST TO FULLY TRANSITION TO
RAIN...WHICH WILL NOT BE UNTIL AFTERNOON...BUT SITES TO THE SOUTH
SHOULD SEE THE TRANSITION TAKE PLACE BEFORE NOON. IFR RESTRICTIONS
LOOK LIKELY...AND AFTER A BRIEF BREAK DURING THE MID
AFTERNOON...DROP DOWN TO IFR/LIFR WITH PERIODS OF MODERATE RAIN.
OUTLOOK.../SATURDAY THROUGH WEDNESDAY/...
WDSPRD RSTRNS AND OCNL LLWS ARE EXPD WITH WKEND LOW PRES. RSTRNS
ARE ALSO PSBL WITH A SERIES OF DISTURBANCES ERLY NXT WK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZING RAIN ADVISORY FROM 5 AM TO 7 PM EST SATURDAY FOR
MDZ001.
OH...NONE.
PA...FREEZING RAIN ADVISORY FROM 5 AM TO 2 PM EST SATURDAY FOR
PAZ007>009-013>016-022-023-074-076.
WV...FREEZING RAIN ADVISORY FROM 5 AM TO 2 PM EST SATURDAY FOR
WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
914 PM EST FRI JAN 2 2015
.UPDATE...
SATELLITE DATA IS SHOWING THE MOISTURE FLUX INTO THE LOWER OHIO
VALLEY WELL UNDERWAY WITHIN THE STREAM OF ISENTROPIC ASCENT TIED
TO THE ENTRANCE REGION OF AN UPPER JET MAX EXTENDING ACROSS LOWER
MI. THE WATER VAPOR LOOP ALSO SHOWS A MID LEVEL SHORT WAVE OVER
ERN NEBRASKA. THIS LEAD WAVE IS FORECAST TO DAMPEN AS IT LIFTS
INTO NRN LOWER MI SAT MORNING...SUSTAINING THE UPPER JET MAX OVER
LOWER MI. THE PERSISTENT ISENTROPIC UPGLIDE INTO SRN MI WILL PULL
THE DEEPER MOISTURE INTO THE AREA SAT MORNING. THE 18Z MODEL
GUIDANCE AND LATEST RAP SUGGEST PRECIP WILL OVERSPREAD THE
FORECAST AREA FROM THE SOUTH AND WEST BETWEEN 11Z AND 14Z.
DESPITE THE THICK CIRRUS DECK NOW COVERING SRN MI...TEMPS HAVE
MANAGED TO DROP OFF INTO THE MID AND UPPER 20S. DEWPOINTS HOWEVER
ARE STILL IN THE UPPER TEENS AND LOW 20S ACROSS SRN MI AND NRN
IN/NRN OH. IN LIGHT OF THE WET BULB COOLING...A PERIOD OF FROZEN
PRECIP STILL LOOKS LIKELY PRIOR TO THE CHANGE OVER TO RAIN SAT
AFTERNOON. 18Z MODEL SOUNDINGS SUGGEST PRECIP WILL BE ALL SNOW AT
THE ONSET /EVEN IN METRO DETROIT/ GIVEN THE WET BULB
COOLING...WITH A TRANSITIONS TO SLEET...FREEZING RAIN AND RAIN
DURING THE COURSE OF THE DAY AS THE ELEVATED WARM LAYER EXPANDS
NORTHWARD. OUTSIDE OF ADDING A BRIEF PERIOD OF SNOW SOUTH OF M 59
SAT MORNING...THE CURRENT FORECAST AND WINTER WEATHER ADVISORY IN
EFFECT FOR SATURDAY WILL REMAIN UNCHANGED.
&&
.AVIATION...ISSUED 613 PM EST FRI JAN 2 2015
LIGHT WINDS AND DRY AIR IN THE LOW LEVELS WILL MAINTAIN QUIET
AVIATION CONDITIONS THROUGH THE NIGHT. THE STORM SYSTEM LIFTING
INTO THE REGION ON SATURDAY WILL CAUSE PRECIPITATION TO LIFT FROM
SOUTH TO NORTH ACROSS SE MI DURING THE DAY...BEGINNING AROUND OR
SHORTLY AFTER DAYBREAK. THE PRECIP IS EXPECTED TO START AS SNOW
AND SLEET...THEN TRANSITION TO FREEZING RAIN...THEN RAIN AS THE
THERMAL PROFILES WARM. THERE IS STILL SOME UNCERTAINTY WITH
RESPECT TO THE TIMING OF THESE PRECIP TYPE CHANGES ATTM. SO THERE
IS LIKELY TO BE ADJUSTMENTS IN THE CHANGE OVER TIMES DURING LATER
FORECAST ISSUANCES.
FOR DTW...CONSENSUS AMONG THE 18Z MODEL GUIDANCE SUGGEST PRECIP WILL
BEGIN AT METRO AROUND 12Z. EXPECT CONDITIONS TO WARM ENOUGH TO
SUPPORT ALL RAIN BY EARLY AFTERNOON. A LIGHT GLAZING OF ICE IS
EXPECTED TO OCCUR DURING AT LEAST THE MORNING HOURS ON SATURDAY.
//DTW THRESHOLD PROBABILITIES...
* MEDIUM CONFIDENCE IN PRECIPITATION STARTING OUT FROZEN
(SLEET/FREEZING RAIN) SAT MORNING...CHANGING TO RAIN BY EARLY
AFTERNOON.
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT AFTER 12Z SAT.
&&
.PREV DISCUSSION...ISSUED 358 PM EST FRI JAN 2 2015
SHORT TERM...TONIGHT
ENOUGH SUNSHINE THIS AFTERNOON HELPED BOOST TEMPERATURES ABOVE THE
FREEZING MARK ACROSS THE MAJORITY OF SOUTHEAST MICHIGAN.
HOWEVER...WITH DEW PTS IN THE TEENS...WE ARE SET UP FOR A QUICK FALL
THIS EVENING AS WINDS GO CALM/LIGHT UNDER PARTLY CLOUDY SKIES/HIGH
CLOUDS. A GOOD SURGE OF MOISTURE/WARM ADVECTION WILL TAKE PLACE
OVERNIGHT AS SHORTWAVE OVER NEBRASKA LIFTS INTO THE WESTERN GREAT
LAKES. CLOUDS WILL QUICKLY THICKEN UP OVERNIGHT...AND WITH SURFACE
WINDS PICKING UP OUT OF THE SOUTHEAST...TEMPERATURES SHOULD BEGIN TO
SLOWLY RISE TOWARD SUNRISE. GOOD CHANCE THE BEST RADIATORS/THUMB
REGION SLIPPING INTO THE UPPER TEENS WITH PREDOMINATELY LOWER 20S
ELSEWHERE BEFORE TEMPS BEGIN THE UPWARD CLIMB. SHOULD REMAIN DRY IN
THE TONIGHT PERIOD...AS 12Z NAM INDICATING 285 K SATURATION OVER
SOUTHWEST LOWER MICHIGAN...WITH CONDENSATION PRESSURE DEFICIT STILL
AROUND 100 MB THROUGH 12Z SATURDAY OVER MUCH OF SOUTHEAST
MICHIGAN...EXCEPT ACROSS THE FAR SOUTHWEST WHERE WE WILL INCLUDE LOW
CHANCE POPS FOR A WINTRY MIX OF PRECIPITATION.
LONG TERM... SATURDAY THROUGH FRIDAY
A WINTER WEATHER ADVISORY IS IN EFFECT SATURDAY WITH INCREASED
CONFIDENCE ON A PERIOD OF MIXED PRECIPITATION OVER SE MICHIGAN.
EXPECT MOSTLY FREEZING RAIN WITH NEAR A TENTH INCH OF ICING
FROM THE OHIO BORDER UP TO THE NORTHERN SUBURBS OF DETROIT WHERE THE
M-59 CORRIDOR WILL START A GREATER MIX WITH SNOW AT THE ONSET. IT
WILL BE ALL SNOW IN FLINT...THE TRI CITIES AND NORTHERN THUMB TO
START BEFORE A TRANSITION TO SLEET AND FREEZING RAIN BY AFTERNOON.
A GENERAL 1 TO 3 INCH SNOW ACCUMULATION IS EXPECTED BUT WITH A
SUBSTANTIAL COMPONENT OF SLEET AND ABOUT A TENTH INCH OF ICING
LIKELY BEFORE SURFACE TEMPERATURE RISES ABOVE FREEZING ALL
LOCATIONS DURING MID TO LATE AFTERNOON.
A KEY FACTOR IN OBSERVATIONS TODAY IS JUST HIGH CLOUDS OVERHEAD
AFTER DISSIPATION OF THE SURFACE FRONT. THIS WILL GIVE TEMPERATURES
A HEAD START DOWN INTO THE 20S TONIGHT FOR A STARTING POINT
SATURDAY AS AND PRECIPITATION MOVES IN FROM THE SOUTH TOWARD
SUNRISE. SURFACE PRESSURE FALLS OVER THE UPPER MIDWEST...
ASSOCIATED WITH THE NORTHERN STREAM UPPER LEVEL TROUGH...COMBINED
WITH THE DEVELOPING LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS...
WILL RESULT IN MODERATE SOUTHEAST WIND OVER LOWER MICHIGAN. THIS
IS NOT SUPPORTIVE OF A CONTINUOUS RESUPPLY OF LOW LEVEL COLD AIR
BUT ALSO IS NOT IDEAL FOR A RAPID SCOURING OF THE SHALLOW SUB
FREEZING BOUNDARY LAYER AIR THAT WILL BE IN PLACE OVER SE
MICHIGAN. PRECIPITATION RATE EARLY IN THE EVENT WILL ALSO BE MORE
LIKELY TO COOL THE SURFACE LAYER THROUGH WET BULB PROCESSES BEFORE
THE MAIN SURGE OF PRECIPITATION ARRIVES DURING THE AFTERNOON AND
REALLY MOISTENS UP AND WARMS CONDITIONS ABOVE FREEZING FROM SOUTH
TO NORTH OVER THE REGION.
THE 12Z MODEL PACKAGE IS IN REASONABLE AGREEMENT ON THE EVOLUTION OF
THE LARGER SCALE FEATURES COMING TOGETHER OVER THE GREAT LAKES FOR
THIS EVENT. THE INITIAL ROUND OF FORCING FOR PRECIPITATION WILL BE
ASSOCIATED WITH MID LEVEL WARM ADVECTION/ISENTROPIC LIFT ASSOCIATED
WITH LONG WAVE HEIGHT RISES DOWNSTREAM OF THE WAVE DIGGING INTO THE
CENTRAL ROCKIES TONIGHT. THIS APPEARS SOLID IN SATELLITE IMAGERY
WITH THE ADDED BONUS OF THE COMPACT AND INTENSE CIRCULATION
EMBEDDED WITHIN THE SOUTHERN STREAM WHICH WILL LEAD THE FOUR
CORNERS SYSTEM OUT OF THE SOUTHERN PLAINS. THE LEAD WAVE WILL ADD
A LAYER OF DYNAMIC FORCING TO GO ALONG WITH THE GENERAL PATTERN OF
DEEP THETA-E ADVECTION. AT THE SAME TIME...SURFACE LOW DEVELOPMENT
OVER THE NORTHERN PLAINS AND UPPER MIDWEST WILL AUGMENT LOW LEVEL
WARM ADVECTION FORCED BY THE LARGER SCALE DOWNSTREAM RIDGE
DEVELOPMENT. MODEL SOLUTIONS THEN INDICATE BULK THICKNESS AND LOW
LEVEL TEMPERATURE FIELDS WARMING QUICKLY FROM SOUTH TO NORTH OVER
LOWER MICHIGAN LEAVING ONLY THE TRI CITIES NEAR THE RAIN/SNOW LINE
BY AFTERNOON. MODEL SOUNDINGS INDICATE ENOUGH MID LEVEL WARMING
FOR A RAPID TRANSITION THROUGH FROZEN TO LIQUID PRECIPITATION
TYPES TO SUCH AN EXTENT THAT THE DETROIT METRO AREA MAY NOT SEE
ANY SNOW EARLY IN THE EVENT. THE INITIAL MOISTURE SURGE WILL THEN
RELOAD WITH THE SOUTHERN PLAINS UPPER LOW. PRECIPITATION TYPE WILL
THEN CHANGE TO ALL RAIN AS RATES INCREASE WITH THIS FEATURE. THE
TRI CITIES WILL REMAIN CLOSEST TO THE RAIN/SNOW LINE PUSHED
FARTHER INTO NORTHERN/WESTERN LOWER BY THEN.
MUCH COLDER AIR AND STRONG WIND WILL THEN BECOME THE MAIN STORY
BY SUNDAY AS THE LOW PRESSURE SYSTEM EXITS THE REGION. LIGHT
ACCUMULATION OF SNOW IS LIKELY UNDER THE MID LEVEL DEFORMATION
PATTERN...WHICH IS STILL SUBJECT TO SOME POSITIONAL ADJUSTMENT IN
UPCOMING MODEL RUNS...BUT CURRENTLY FAVORS AN INCH OR TWO OF
ADDITIONAL SNOW ACCUMULATION MAINLY IN THE TRI CITIES TO NORTHERN
THUMB REGION.
THE FIRST CONCERN IN THE EXTENDED PERIOD WILL BE A PERIOD OF COLD
ARCTIC AIR FILTERING IN TO THE REGION IN THE BEGINNING OF NEXT WEEK.
BEHIND THE DEPARTING LOW PRESSURE SYSTEM VERY COLD AIR WILL STREAM
INTO THE GREAT LAKES REGION RESULTING IN HIGHS ON MONDAY BARELY
RISING OUT OF THE SINGLE DIGITS /15 FOR DETROIT METRO...ONLY 11 FOR
MOST OF THE REST OF THE CWA/. LOWS ON MONDAY NIGHT WILL DROP INTO
THE MIDDLE SINGLE DIGITS WITH WIND CHILL VALUES IN THE NEGATIVE
SINGLE DIGITS. TUESDAYS HIGHS WILL BE SLIGHTLY WARMER IN THE UPPER
TEENS AND LOW 20S.
THE SECOND CONCERN FOR THE EXTENDED PERIOD WILL BE THE CHANCE OF A
CLIPPER SYSTEM TO IMPACT THE CENTRAL GREAT LAKES ON TUESDAY AND
TUESDAY NIGHT. MODELS ARE FAIRLY CONSISTENT ON THIS FEATURE
HOWEVER...INCONSISTENT WITH THE TIMING AND INTENSITY. THEREFORE IT
IS TOO EARLY TO TRY TO PINPOINT SNOWFALL TOTALS AT THIS TIME.
MARINE...
WINDS BECOMING LIGHT THIS EVENING WILL SHIFT TO THE SOUTHEAST
OVERNIGHT...AS LOW PRESSURE LIFTS INTO THE OHIO VALLEY TOMORROW.
SUSTAINED WINDS UP TO 20 KNOTS OVER SOUTHERN LAKE HURON WILL PRODUCE
WAVES 4 FEET OR SLIGHTLY BETTER...WHICH SHOULD BRUSH THE NEARSHORE
WATERS ALONG THE EASTERN THUMB REGION...AND THUS HAVE ISSUED SMALL
CRAFT ADVISORIES. THE LOW OF THE OHIO VALLEY WILL THEN TRACK IN
BETWEEN THE CENTRAL AND EASTERN GREAT LAKES TOMORROW NIGHT...WITH
VERY COLD AIR FOLLOWING FOR SUNDAY AND MONDAY. NORTHWEST WINDS OF AT
LEAST 30 KNOTS ARE EXPECTED OVER LAKE HURON WITH THE DEEP
MIXING...AND GALES ARE CERTAINLY POSSIBLE LATE SUNDAY AND SUNDAY
EVENING. HAVE GONE AHEAD AND ISSUED GALE WATCH FOR THE NORTHERN TWO
THIRDS OF LAKE HURON. WITH THE COLD AIRMASS...FREEZING SPRAY WILL
LIKELY BE AN ISSUE DURING THIS TIME FRAME AS WELL.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR
MIZ047>049-053>055-060>063-068>070-075-076-082-083.
LAKE HURON...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR LHZ441-442.
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT FOR
LHZ361>363.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
UPDATE.......SC
AVIATION.....SC
SHORT TERM...SF
LONG TERM....BT/RK
MARINE.......BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
410 PM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM EST THU JAN 1 2015
DEEP TROUGH ALOFT CENTERED OVER HUDSON BAY. MULTIPLE SHORTWAVES
MOVING THROUGH THE BASE OF THE TROUGH...BUT AFTER THE SHORTWAVE
MOVED THROUGH THIS MORNING...THERE IS NO LARGER SCALE SUPPORT OVER
THE AREA OR UPSTREAM. PRIMARY COLD FRONT TIED TO THE LAST SHORTWAVE
IS CURRENTLY SINKING SOUTHWARD OVER UPR MICHIGAN. BAND OF HEAVY SNOW
ALONG THE FRONT HAS WORKED THROUGH MARQUETTE AND MUNISING AND IS NOW
ALLIGNED FM SAWYER TO CHATHAM TO SHINGLETON AND TO NEWBERRY AS OF 20Z.
VSBY DOWN TO 1/4SM IN THIS SNOW BAND...BUT IT IS NOT LASTING TOO LONG.
LES OVER THE WESTERN CWA IS SCUFFLING ALONG. IN FACT AFTER THE FRONT
MOVED THROUGH THE KEWEENAW...SPOTS HAVE CLEARED OUT BRIEFLY. HINTS OF
WIND PARALLEL BANDS OVER WESTERN LK SUPERIOR...BUT DRY AIR AND
INVERSIONS BLO 5KFT IS LIMITING THIS DEVELOPMENT. BETTER LES
DEVELOPMENT OVER EASTERN LK SUPERIOR WITH CLOUD STREETS EXTENDING
BACK TO NCNTRL LK SUPERIOR. WILL TAKE A FEW HOURS...BUT DO EXPECT AT
LEAST MODERATE LES TO DEVELOP IN THE NW LOW-LEVEL WINDS INTO EASTERN
CWA. BLYR WINDS OVER 30 KTS INTO THE EVENING WILL RESULT IN BLSN/POOR
VSBY IN THE HEAVIER SNOW BANDS. INVERSIONS 5-8 KFT AND TEMPS AT
INVERSION TOP OF -20C SHOULD AT LEAST RESULT IN SCT HEAVIER SNOW
SHOWERS. 17Z HRRR DOING NICE JOB WITH EXPECTED EVOLUTION THROUGH THE
EVENING...THOUGH IT SEEMS A BIT SLOW WITH TIMING OF HEAVIER SNOW BAND
TIED TO THE FRONT.
ADDITIONAL SNOW AMOUNTS SHOULD STAY IN CHECK GIVEN LACK OF ENHANCED
MOISTURE AND LIFT SINCE WE ARE WITHIN A PURE LES REGIME. SUPPOSE IF
SNOW BANDS CAN STAY ANCHORED IN ONE PLACE THROUGH THE NIGHT...MAY SEE
SEVERAL INCHES OF FLUFFY ACCUMS AS ALL CONVECTIVE DEPTH IS WITHIN THE
DGZ. ALREADY ISSUED LES ADVISORY THROUGH MIDNIGHT FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES. AFTER MIDNIGHT SEEMS THAT DRY AIR
AND LOWER INVERSIONS THAT ARE AFFECTING WESTERN LK SUPERIOR AND CWA
WILL PUT CRIMP IN THE LES INTENSITY OVERNIGHT. WEAK LES WILL CONTINUE
INTO FRIDAY...MAINLY FOR AREAS FAVORED BY WNW-W WINDS...SO ESSENTIALLY
THE SNOW BELTS OF THE KEWEENAW AND ALSO TO THE EAST OF MUNISING.
CONDITIONS EVEN MORE UNFAVORABLE THAN LATER TONIGHT...BUT WITH DGZ
DOMINATING THE CONVECTIVE LAYER STILL COULD SQUEEZE OUT A COUPLE MORE
INCHES OF FLUFF IN PERSISTENT SNOW SHOWERS.
AWAY FM THE LES TONIGHT...LOWERED SKY COVER AND TEMPERATURES AS THE
DRIER AIR SHOULD WIN OUT AS IS OCCURRING UPSTREAM IN MINNESOTA AND
NORTHWEST ONTARIO THIS AFTN. INTERIOR TEMPS SHOULD DIP WELL BLO ZERO
ONCE THE NW WINDS BEHIND THE COLD FRONT BEGIN TO BACK OFF. SHOULD BE
SHARP GRADIENT TO MIN TEMPS AS YOU GET CLOSER TO LK SUPERIOR DUE TO
LINGERING LAKE EFFECT CLOUDS AS 925MB WINDS STAY WNW-NW THROUGH THE
NIGHT. ALSO MAY SEE TEMPS STEADY OR RISE LATE IN THE WEST WITH
ADVANCING DECK OF 6-9KFT ALTOSTRATUS CLOUDS. ANOTHER COOL DAY WITH
AFTN READINGS IN THE TEENS OVER THE CWA.
.LONG TERM...(FRIDAY NIGHT THROUGH THURSDAY)
ISSUED AT 408 PM EST THU JAN 1 2015
A PROMINENT RIDGE GRADUALLLY BUILDING TO THE EAST INTO WRN NOAM WILL
MAINTAIN A BROAD TROUGH FROM CENTRAL CANADA INTO THE GREAT LAKES.
AFTER LOW PRESSURE SYSTEM LIFTS NE FROM THE CNTRL GREAT LAKES...MUCH
COLDER AIR WILL MOVE INTO THE REGION AND REMAIN THROUGH MUCH OF NEXT
WEEK KEEPING LES GOING FOR MAINLY NW TO WNW FLOW FAVORED LOCATIONS.
FRI NIGHT AND SAT...A BROAD 850-600 MB WARM ADVECTION 280K-295
ISENTROPIC LIFT ZONE WILL DEVELOP FROM THE NRN PLAINS INTO NRN MN AND NRN
LAKE SUPERIOR IN RESPONSE TO THE DEVELOPING TROUGH OVER THE PLAINS
AND UPPER LEVEL DIV WITH THE RIGHT ENTRANCE OF A 250-300 MB JET
STREAK THROUGH NRN ONTARIO. THE MODELS KEEP MOST OF THE PCPN WITH
THIS FEATURE NORTH OF UPPER MI. WAA WILL RAISE TEMPS AT OR
SLIGHTLY ABOVE AVERAGE WITH READINGS IN THE MID TO UPPER 20S.
SAT NIGHT INTO SUN...A SHRTWV ORIGINATING FROM THE GULF OF ALASKA
DIVING INTO THE WRN CONUS TROUGH WILL HELP EJECT THE SW CLOSED LOW
NE TOWARD THE GREAT LAKES. THE 12Z GFS/ECMWF ALONG WITH ENSEMBLES
FAVOR A LOW TRACK FROM THE SRN END OF LAKE MI TO CNTRL LAKE HURON
AND THEN NE INTO QUEBEC. STRONG 700-300 MB QVECTOR CONV ASSOCIATED
WITH THE SHRTWV WILL SUPPORT A BROAD AREA OF SNOW FROM WI INTO UPPER
MI BY LATE SAT AND ESPECIALLY LATE SAT NIGHT. MDLS CONSENSUS QPF IN
THE 0.20 TO 0.35 INCH RANGE WITH SLR VALUES AROUND 14/1 WILL SUPPORT
POTENTIAL FOR 3 TO 6 INCHES BY 18Z/SUN. ADDITIONAL SUPPORT FOR
HEAVIER SNOW IS EXPECTED OVER THE NORTH CYCLONIC NRLY FLOW AND 850
MB TEMPS DROPPING FROM -10C TO -15C BY 12Z TO -14C TO -19C BY 18Z
WILL RESULT HIGHER AMOUNTS THROUGH LAKE ENHANCEMENT. BY SUN
AFTERNOON THE DEEPER MOISTURE AND SYNOPTIC SUPPORT LIFT QUICKLY WITH
A TRANSITION TO LIGHTER PURE LES.
SUN NIGHT INTO MON...VERY COLD ARCTIC AIR WILL PLUNGE INTO THE
REGION WITH 850 MB TEMPS DROPPING TO AROUND -27C BY 12Z MON. THIS
WILL LOWER THE DGZ TOWARD THE SFC AND REDUCE POTENTIAL FOR
SIGNIFICANT LES. HOWEVER...WIND CHILL WITH A MORE WRLY SFC WIND
COMPONENT RESULTING FROM LAKE INDUCED TROUGHING WILL ALLOW TEMPS TO
DROP OFF OVER MUCH OF THE CWA. WIND CHILL VALUES IN THE -20 TO -35
RANGE ARE EXPECTED.
TUE-THU...A FEW CLIPPER SHRTWVS ARE LIKELY TO MOVE THROUGH THE REGION WITH
NW-NNW MID LEVEL FLOW IN PLACE. THIS MAY BRING REINFORCING BOUTS OF
COLD AIR AND SHIFT THE POSITIONS OF THE HEAVIER LES BANDS. TEMPS MAY
MODERATE SLIGHTLY IF SFC WINDS VEER MORE TO THE NW WITH MORE MARINE
MODIFICATION. HOWEVER...WIND CHILLS MAY REMAIN NEAR ADVY THRESHOLD
DURING THE LATER NIGHT INTO MORNING HOURS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM EST THU JAN 1 2015
COLD FRONT HAS MADE IT THROUGH KCMX AND WILL IMPACT KIWD AND KSAW
WITH A PERIOD OF SNOW SHOWERS AND BLOWING SNOW THIS AFTN. AT KIWD
AND KSAW...GENERALLY THE CIGS WILL BE MVFR INTO TONIGHT. VSBY WILL
BE IFR OR MVFR...BUT WILL BEGIN TO IMPROVE BY EARLY EVENING AS DRIER
AIR ERODES THE LAKE EFFECT SNOW SHOWERS. WILL SEE IMPROVEMENT TO VFR
LATE TONIGHT INTO FRIDAY AT KIWD AND KSAW. AT KCMX...PERSISTENT WNW-
NW FLOW OFF LK SUPERIOR WILL KEEP LAKE EFFECT SNOW SHOWERS WITH IFR
TO MVFR VSBY THROUGH THE PERIOD. STRONGEST WINDS WITH BLSN THIS
AFTN...THEN WINDS DIMINISH SIGNIFICANTLY THIS EVENING AND OVERNIGHT
TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EST THU JAN 1 2015
NW GALES DIMINISH THIS EVENING OVER THE EAST HALF. HEAVY FREEZING
SPRAY WILL ALSO END LATE TONIGHT. WINDS SETTLE DOWN TO LESS THAN 25
KTS LATER TONIGHT THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES
OVERHEAD. EXPECT A BRIEF PERIOD OF STRONGER SE WINDS ON SATURDAY...BUT
THE BETTER CHANCE OF STRONGER WINDS WILL BE LATE SATURDAY NIGHT INTO
SUNDAY AS NORTH TO NORTHWEST WINDS INCREASE AS A LOW PRESSURE SYSTEM
LIFTS OVER THE GREAT LAKES THEN MOVES EAST OVER QUEBEC. BEST SHOT OF
GALES WILL BE OVER THE EAST HALF OF LK SUPERIOR ON SUNDAY. NW WINDS
TO 30 KTS WILL LINGER OVER MUCH OF LK SUPERIOR INTO EARLY NEXT WEEK
BEHIND THE WEEKEND SYSTEM. MORE HEAVY FREEZING SPRAY IS EXPECTED LATE
THIS WEEKEND INTO EARLY NEXT WEEK AS ARCTIC AIR FLOWS ACROSS LK
SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST FRIDAY FOR LSZ265-
267.
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ FRIDAY
FOR LSZ241>245-263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...JLB
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
353 PM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY)
ISSUED AT 351 PM EST THU JAN 1 2015
DEEP TROUGH ALOFT CENTERED OVER HUDSON BAY. MULTIPLE SHORTWAVES
MOVING THROUGH THE BASE OF THE TROUGH...BUT AFTER THE SHORTWAVE
MOVED THROUGH THIS MORNING...THERE IS NO LARGER SCALE SUPPORT OVER
THE AREA OR UPSTREAM. PRIMARY COLD FRONT TIED TO THE LAST SHORTWAVE
IS CURRENTLY SINKING SOUTHWARD OVER UPR MICHIGAN. BAND OF HEAVY SNOW
ALONG THE FRONT HAS WORKED THROUGH MARQUETTE AND MUNISING AND IS NOW
ALLIGNED FM SAWYER TO CHATHAM TO SHINGLETON AND TO NEWBERRY AS OF 20Z.
VSBY DOWN TO 1/4SM IN THIS SNOW BAND...BUT IT IS NOT LASTING TOO LONG.
LES OVER THE WESTERN CWA IS SCUFFLING ALONG. IN FACT AFTER THE FRONT
MOVED THROUGH THE KEWEENAW...SPOTS HAVE CLEARED OUT BRIEFLY. HINTS OF
WIND PARALLEL BANDS OVER WESTERN LK SUPERIOR...BUT DRY AIR AND
INVERSIONS BLO 5KFT IS LIMITING THIS DEVELOPMENT. BETTER LES
DEVELOPMENT OVER EASTERN LK SUPERIOR WITH CLOUD STREETS EXTENDING
BACK TO NCNTRL LK SUPERIOR. WILL TAKE A FEW HOURS...BUT DO EXPECT AT
LEAST MODERATE LES TO DEVELOP IN THE NW LOW-LEVEL WINDS INTO EASTERN
CWA. BLYR WINDS OVER 30 KTS INTO THE EVENING WILL RESULT IN BLSN/POOR
VSBY IN THE HEAVIER SNOW BANDS. INVERSIONS 5-8 KFT AND TEMPS AT
INVERSION TOP OF -20C SHOULD AT LEAST RESULT IN SCT HEAVIER SNOW
SHOWERS. 17Z HRRR DOING NICE JOB WITH EXPECTED EVOLUTION THROUGH THE
EVENING...THOUGH IT SEEMS A BIT SLOW WITH TIMING OF HEAVIER SNOW BAND
TIED TO THE FRONT.
ADDITIONAL SNOW AMOUNTS SHOULD STAY IN CHECK GIVEN LACK OF ENHANCED
MOISTURE AND LIFT SINCE WE ARE WITHIN A PURE LES REGIME. SUPPOSE IF
SNOW BANDS CAN STAY ANCHORED IN ONE PLACE THROUGH THE NIGHT...MAY SEE
SEVERAL INCHES OF FLUFFY ACCUMS AS ALL CONVECTIVE DEPTH IS WITHIN THE
DGZ. ALREADY ISSUED LES ADVISORY THROUGH MIDNIGHT FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES. AFTER MIDNIGHT SEEMS THAT DRY AIR
AND LOWER INVERSIONS THAT ARE AFFECTING WESTERN LK SUPERIOR AND CWA
WILL PUT CRIMP IN THE LES INTENSITY OVERNIGHT. WEAK LES WILL CONTINUE
INTO FRIDAY...MAINLY FOR AREAS FAVORED BY WNW-W WINDS...SO ESSENTIALLY
THE SNOW BELTS OF THE KEWEENAW AND ALSO TO THE EAST OF MUNISING.
CONDITIONS EVEN MORE UNFAVORABLE THAN LATER TONIGHT...BUT WITH DGZ
DOMINATING THE CONVECTIVE LAYER STILL COULD SQUEEZE OUT A COUPLE MORE
INCHES OF FLUFF IN PERSISTENT SNOW SHOWERS.
AWAY FM THE LES TONIGHT...LOWERED SKY COVER AND TEMPERATURES AS THE
DRIER AIR SHOULD WIN OUT AS IS OCCURRING UPSTREAM IN MINNESOTA AND
NORTHWEST ONTARIO THIS AFTN. INTERIOR TEMPS SHOULD DIP WELL BLO ZERO
ONCE THE NW WINDS BEHIND THE COLD FRONT BEGIN TO BACK OFF. SHOULD BE
SHARP GRADIENT TO MIN TEMPS AS YOU GET CLOSER TO LK SUPERIOR DUE TO
LINGERING LAKE EFFECT CLOUDS AS 925MB WINDS STAY WNW-NW THROUGH THE
NIGHT. ALSO MAY SEE TEMPS STEADY OR RISE LATE IN THE WEST WITH
ADVANCING DECK OF 6-9KFT ALTOSTRATUS CLOUDS. ANOTHER COOL DAY WITH
AFTN READINGS IN THE TEENS OVER THE CWA.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EST THU JAN 1 2015
PERSISTENT RIDGING OVER THE EASTERN PACIFIC/NAMERICA WEST COAST
REGION WILL MAINTAIN A BROAD UPPER TROUGH OVER MUCH OF CANADA AND
THE GREAT LAKES REGION THROUGH THE FIRST WEEK OF JANUARY RESULTING
IN BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW FOR
UPPER MI.
BEGINNING FRIDAY...MODEL CONSENSUS SUGGESTS WINDS WL BACK MORE
WESTERLY AGAIN AS SFC RDG AXIS ADVANCES ACROSS AREA FROM THE NRN
PLAINS. THE GENERALLY WEAK WRLY FLOW ALONG WITH ENHANCED LOW-LVL
CONVERGENCE FROM LAND BREEZES WL HELP FOCUS GENERALLY LIGHT LAKE
EFFECT SNOW ACROSS THE KEWEENAN PENINSULA AND THE FAR ERN SHORELINE
OF THE CWA AS INVERSION BASES CRASH BLO 5KFT WITH DRY AIR NOTED
BENEATH THE INVERSION. SINCE MUCH OF THE DGZ IN STILL WITHIN THE
CLOUD LAYER...LES BANDS COULD YIELD 1-2 INCHES OF FLUFFY
ACCUMULATION DURING THE DAY. WAA CLOUDS AHEAD OF SHORTWAVE MOVING IN
FROM THE NRN PLAINS WILL LIMIT RADIATIONAL COOLING FRIDAY NIGHT BUT
TEMPS SHOULD STILL APPROACH ZERO OR MAYBE EVEN DIP BLO ZERO AT A FEW
OF THE TYPICAL COLDER LOCATIONS OVER THE WESTERN INTERIOR.
THIS WEEKEND...FOCUS IS ON PHASING/INTERACTION OF SPLIT FLOW. TWO
FEATURES WILL COME INTO PLAY...ONE WILL BE THE REMNANTS OF A CLOSED
LOW NOW PRODUCING SNOW OVER THE SW CONUS...AND THE SECOND IS A NRN
BRANCH SHORTWAVE NOW OVER THE ALEUTIAN ISLANDS WHICH IS FCST TO DIVE
SE ACROSS THE NRN ROCKIES FRI NIGHT AND THEN THROUGH THE PLAINS
STATES ON SAT. ASSOCIATED STRONG MID LEVEL WARM AIR ADVECTION AHEAD
OF THIS SHORTWAVE AND ITS ASSOC SFC LOW WILL SPREAD SNOW EAST INTO
MAINLY THE NORTHWEST HALF OF THE CWA ON SAT. WHILE THE MODELS STILL
PEG THE HEAVIEST SNOW TO OCCUR OVER LAKE SUPERIOR...WILL CONTINUE TO
SHOW SOME LIKELY POPS OVER AND AROUND THE KEWEENAW PENINSULA FOR
SATURDAY. AS THIS SNOW IS OCCURRING...THE NORTHERN SHORTWAVE WILL
CONTINUE TO DIVE SOUTHEAST AND BEGIN TO PHASE WITH THE REMNANTS OF
THE SW CONUS UPPER LOW WHICH WILL LEAD TO BOTH FEATURES EJECTING
NORTHEAST THROUGH THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO
SUNDAY. THE 00Z ECMWF...GFS AND NAM ALL TRENDING DEEPER AND FARTHER
WEST WITH RESULTING SFC LOW WHICH BLEND OF THESE MODELS SHOW A TRACK
THROUGH SRN LWR MI TO NEAR GEORGIAN BAY BY 12Z SUNDAY. THE GEM-NH
MEANWHILE AFTER SHOWING A SIMILAR TRACK TO THE 00Z ECMWF/GFS BLEND
HAS NOW TRENDED FARTHER EAST THROUGH SE LOWER MI INTO ERN ONTARIO.
IF THE LATEST GFS/ECMWF SOLNS HOLD TRUE THIS WOULD MEAN A GREATER
POTENTIAL FOR SYNOPTIC PCPN TO SPREAD INTO UPPER MI...ESPECIALLY THE
EAST HALF...ALONG WITH A GREATER POTENTIAL FOR NORTH FLOW LAKE
ENHANCED SNOW ON THE BACKSIDE OF THE SYSTEM. WILL LIKELY NEED TO
TREND POPS UPWARD ACROSS THE CWA AND ESPECIALLY ALONG LAKE SUPERIOR
ZONES WITH A GREATER POTENTIAL FOR LAKE ENHANCED SNOW SAT NIGHT INTO
SUNDAY. WINDS WILL ALSO RAMP UP WITH TIGHTER GRADIENT ON BACKSIDE OF
SYSTEM WHICH WILL ALSO RESULT IN MORE BLOWING SNOW. WILL HIGHLIGHT
POTENTIAL FOR MODERATE SNOW AND BLOWING SNOW IN HWO...ESPECIALLY
ALONG LAKE SUPERIOR AND THE EAST HALF OF THE CWA FOR SAT NIGHT INTO
SUNDAY EVENING.
LATE SUNDAY NIGHT INTO MONDAY NIGHT...WEAKENING PRES GRADIENT WILL
ALLOW WINDS TO DIMINISH ESPECIALLY OVER THE INTERIOR. WINDS WILL
ALSO BE BACKING MORE WESTERLY ESPECIALLY BY MONDAY IN ADVANCE OF
STRONG SFC HIGH PRES RDG BUILDING IN FROM THE NRN PLAINS...SO EXPECT
LES TO EVENTUALLY BECOME MORE CONFINED TO KEWEENAW AND FAR ERN
SHORELINE AREAS OF THE CWA MONDAY AFTERNOON INTO MON NIGHT. WITH
HEART OF COLDEST AIR (850 MB TEMPS OF -26 TO -28C) COMING ACROSS THE
UPPER LAKES...EXPECT VERY COLD TEMPS SUN NIGHT AND MONDAY. EXPECT
MUCH OF THE INTERIOR CWA TO FALL BLO ZERO AND WOULD NOT BE SURPRISED
TO SEE SOME WESTERN INTERIOR LOCATIONS FALL WELL INTO THE TEENS BLO
ZERO... ESPECIALLY ALONG THE WI BORDER. HIGHS MONDAY WILL REMAIN
VERY COLD WITH READINGS RANGING FROM THE SINGLE DIGITS BLO ZERO
WESTERN INTERIOR TO THE SINGLE DIGITS ABV ZERO EAST AND ALONG THE
GREAT LAKES.
TUESDAY INTO WEDNESDAY...MODELS IN REASONABLY GOOD AGREEMENT SHOWING
ANOTHER CLIPPER SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY WITH ANOTHER REINFORCING SHOT OF ARCTIC AIR (8H TEMPS FALL
AGAIN TO -28C TO -30C) AS WINDS VEER TO THE NW. THIS WILL BRING LES
FARTHER INLAND AGAIN AFFECTING THE NRN TIER AND ERN HALF COUNTIES
FROM LATE TUE THROUGH WED. LOOK LIKE ONLY THE FAR SOUTH CENTRAL
WOULD ESCAPE THE LES. WITH SUCH A COLD ARCTIC AIRMASS FCST THE DGZ
WILL GET SQUASHED NEAR THE LAKE SFC WHICH WILL LIKELY RESULT IN
SMALLER FLAKE SIZE. THIS WILL LIMIT LES ACCUMULATION BUT AT SAME
TIME WILL BE MORE EFFECTIVE FOR REDUCING VSBY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM EST THU JAN 1 2015
COLD FRONT HAS MADE IT THROUGH KCMX AND WILL IMPACT KIWD AND KSAW
WITH A PERIOD OF SNOW SHOWERS AND BLOWING SNOW THIS AFTN. AT KIWD
AND KSAW...GENERALLY THE CIGS WILL BE MVFR INTO TONIGHT. VSBY WILL
BE IFR OR MVFR...BUT WILL BEGIN TO IMPROVE BY EARLY EVENING AS DRIER
AIR ERODES THE LAKE EFFECT SNOW SHOWERS. WILL SEE IMPROVEMENT TO VFR
LATE TONIGHT INTO FRIDAY AT KIWD AND KSAW. AT KCMX...PERSISTENT WNW-
NW FLOW OFF LK SUPERIOR WILL KEEP LAKE EFFECT SNOW SHOWERS WITH IFR
TO MVFR VSBY THROUGH THE PERIOD. STRONGEST WINDS WITH BLSN THIS
AFTN...THEN WINDS DIMINISH SIGNIFICANTLY THIS EVENING AND OVERNIGHT
TONIGHT.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 351 PM EST THU JAN 1 2015
NW GALES DIMINISH THIS EVENING OVER THE EAST HALF. HEAVY FREEZING
SPRAY WILL ALSO END LATE TONIGHT. WINDS SETTLE DOWN TO LESS THAN 25
KTS LATER TONIGHT THROUGH FRIDAY NIGHT AS HIGH PRESSURE MOVES
OVERHEAD. EXPECT A BRIEF PERIOD OF STRONGER SE WINDS ON SATURDAY...BUT
THE BETTER CHANCE OF STRONGER WINDS WILL BE LATE SATURDAY NIGHT INTO
SUNDAY AS NORTH TO NORTHWEST WINDS INCREASE AS A LOW PRESSURE SYSTEM
LIFTS OVER THE GREAT LAKES THEN MOVES EAST OVER QUEBEC. BEST SHOT OF
GALES WILL BE OVER THE EAST HALF OF LK SUPERIOR ON SUNDAY. NW WINDS
TO 30 KTS WILL LINGER OVER MUCH OF LK SUPERIOR INTO EARLY NEXT WEEK
BEHIND THE WEEKEND SYSTEM. MORE HEAVY FREEZING SPRAY IS EXPECTED LATE
THIS WEEKEND INTO EARLY NEXT WEEK AS ARCTIC AIR FLOWS ACROSS LK
SUPERIOR. &&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST FRIDAY FOR LSZ265-
267.
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 7 AM EST /6 AM CST/ FRIDAY
FOR LSZ241>245-263-264-266.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLA
LONG TERM...VOSS
AVIATION...JLA
MARINE...JLA
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1246 PM EST THU JAN 1 2015
.UPDATE...
ISSUED AT 1107 AM EST THU JAN 1 2015
WIDESPREAD NOAA WEATHER RADIO OUTAGE ACROSS UPR MICHIGAN CONTINUES
AT THIS HOUR DUE TO LARGER SCALE COMMS OUTAGE WITH VERIZON.
SHORTWAVE WITH WIDEPSREAD LGT SNOW IS EXITING EASTERN CWA. SFC
COLD FRONT IS FINALLY STARTING TO SINK ACROSS SOUTHERN HALF OF LK
SUPERIOR THOUGH IT IS TAKING ITS TIME IN DOING SO. LES OVER THE
KEWEENAW THIS MORNING HAS BEEN HEAVY WITH 1+ INCH PER HOUR RATES.
EXPECT LES TO BECOME LESS FOCUSED THOUGH THROUGH MIDDAY AS WINDS
SHIFT FROM THE STRONG CONVERGENT WESTERLY FLOW TO A MORE SHEARED
NORTHWEST FLOW BEHIND THE COLD FRONT. LAKE EFFECT SNOW ADVISORY
SET TO EXPIRE AT 18Z TODAY FOR NORTHERN HOUGHTON AND KEWEENAW
COUNTIES. BASED ON EXPECTED TRENDS IN LES AND WIND THAT LOOKS GOOD
AND WILL NOT MAKE ANY EXTENSIONS ATTM.
ATTN THEN TURNS TO FROPA OVER EASTERN CWA EARLY TO MID AFTN. EXPECT
DECENT CONVERGENCE BAND TO FIRST AFFECT SNOW BELTS EAST OF MARQUETTE
THEN NW FLOW LES WILL DEVELOP. RAP SOUNDINGS INDICATE INVERSIONS TO
7-8KFT WITH TEMPS AROUND -20C AT INVERSION TOP THROUGH EARLY
EVENING. MIXED LAYER WINDS 25-35 KTS WILL RESULT IN WINDY CONDITIONS
AFTER FROPA WITH BLSN/POOR VSBY. WOULD EXPECT SNOWFALL RATES BTWN
0.5-1.0 INCH PER HOUR THIS AFTN INTO THE EARLY EVENING. MUCH OF THE
CONVECTIVE LAYER IS WITHIN THE DGZ...SO SLR/S WILL BE WELL OVER
20:1.
OPTED TO ISSUE A LAKE EFFECT SNOW ADVISORY FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES THROUGH THE EVENING. SNOW AND BLSN
WILL MAKE TRAVEL DIFFICULT INTO THE EARLY EVENING WITH VSBY DOWN TO
1/4SM AT TIMES...AND SNOW AMOUNTS WILL BE BOOSTED BY HIGHER SLR/S
AND DECENTLY HIGH INVERSIONS. IN WAKE OF FROPA LATE THIS EVENING AND
OVERNIGHT TONIGHT...EXPECT DIMINISHING LES AS INVERSIONS FALL BLO
5KFT...BUT DIMINISHING WINDS AND MOST OF THE CONVECTIVE LAYER WITHIN
THE DGZ WILL STILL BOOST SNOW AMOUNTS. EXPECT SNOW TOTALS TODAY INTO
THIS EVENING OF 2 TO 4 INCHES AND ANOTHER 1 TO 3 INCHES LATER THIS
EVENING INTO THE OVERNIGHT.
UPDATED WSW STATEMENT ALREADY OUT. COORD WITH APX ON THE LAKE EFFECT
SNOW ADVISORY FOR LUCE COUNTY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EST THU JAN 1 2015
THE STACKED SFC-500MB LOW OVER S HUDSON BAY WILL WEAKEN SLIGHTLY AND
DRIFT OVER N QUEBEC OVERNIGHT TONIGHT. THIS WILL KEEP THE UPPER
GREAT LAKES IN NW FLOW ALOFT WITH SEVERAL SMALL WAVES SHIFTING
ACROSS THE AREA. A DOMINANT SFC TROUGH/COLD FRONT HOVERING NEAR THE
N MN BORDER WILL SINK ACROSS UPPER MI THROUGH THE DAY TODAY.
THIS...AND AN SHORTWAVE PUSHING ACROSS THE AREA WILL ALLOW FOR SOME
INTENSIFICATION TO SNOW SHOWERS THIS AFTERNOON. AS A RESULT...WILL
KEEP THE HIGH CHANCE POPS GOING ACROSS THE AREA AROUND 18Z...BEFORE
DIMINISHING THEM AGAIN TO ALONG THE LAKE SUPERIOR SHORELINE THIS
EVENING. 850MB TEMPS WILL FALL FROM THE MORNING READINGS OF -12 TO
-15C TO -18 TO -21C BY DAYBREAK FRIDAY.
AS FOR SPECIFICS...
LES CONTINUES ACROSS THE KEWEENAW PENINSULA...WITH A DOMINANT BAND
STRETCHING ACROSS LAKE SUPERIOR TO NEAR WHITEFISH POINT. LOOK FOR
THE EASTERN LAKE SUPERIOR BAND TO SLOWLY SINK S ONSHORE AS THE
CONVERGENT W TO SW WINDS KEEPING IT JUST OFF THE SHORE RELAX AND NW
WINDS OFF THE LAKE WIN OUT LATER THIS MORNING. THIS WILL PUSH THE
BAND OVER N LUCE COUNTY...WITH 1-3 INCHES OF SNOW FCST FOR MUCH OF
LUCE COUNTY. ANOTHER 1-3 INCHES IS EXPECTED TONIGHT WITH BETTER
CONVERGENCE NEAR WHITEFISH POINT.
WILL KEEP THE LES ADVISORY FOR SNOW AND BLOWING/DRIFTING SNOW GOING
ACROSS THE KEWEENAW PENINUSLA. EXPECT ANY DOMINANT BANDS...HIGHER
SNOW AMOUNTS...TO DRIFT AROUND AND S OF CMX...WITH NEW SNOW TODAY OF
1-3 INCHES.
EXPECT ANOTHER COLD NIGHT...WITH LOWS GENERALLY IN THE SINGLE DIGITS
BELOW AND ABOVE ZERO...WARMEST WHERE CLOUDS AND SNOW SHOWERS LINGER
ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EST THU JAN 1 2015
PERSISTENT RIDGING OVER THE EASTERN PACIFIC/NAMERICA WEST COAST
REGION WILL MAINTAIN A BROAD UPPER TROUGH OVER MUCH OF CANADA AND
THE GREAT LAKES REGION THROUGH THE FIRST WEEK OF JANUARY RESULTING
IN BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW FOR
UPPER MI.
BEGINNING FRIDAY...MODEL CONSENSUS SUGGESTS WINDS WL BACK MORE
WESTERLY AGAIN AS SFC RDG AXIS ADVANCES ACROSS AREA FROM THE NRN
PLAINS. THE GENERALLY WEAK WRLY FLOW ALONG WITH ENHANCED LOW-LVL
CONVERGENCE FROM LAND BREEZES WL HELP FOCUS GENERALLY LIGHT LAKE
EFFECT SNOW ACROSS THE KEWEENAN PENINSULA AND THE FAR ERN SHORELINE
OF THE CWA AS INVERSION BASES CRASH BLO 5KFT WITH DRY AIR NOTED
BENEATH THE INVERSION. SINCE MUCH OF THE DGZ IN STILL WITHIN THE
CLOUD LAYER...LES BANDS COULD YIELD 1-2 INCHES OF FLUFFY
ACCUMULATION DURING THE DAY. WAA CLOUDS AHEAD OF SHORTWAVE MOVING IN
FROM THE NRN PLAINS WILL LIMIT RADIATIONAL COOLING FRIDAY NIGHT BUT
TEMPS SHOULD STILL APPROACH ZERO OR MAYBE EVEN DIP BLO ZERO AT A FEW
OF THE TYPICAL COLDER LOCATIONS OVER THE WESTERN INTERIOR.
THIS WEEKEND...FOCUS IS ON PHASING/INTERACTION OF SPLIT FLOW. TWO
FEATURES WILL COME INTO PLAY...ONE WILL BE THE REMNANTS OF A CLOSED
LOW NOW PRODUCING SNOW OVER THE SW CONUS...AND THE SECOND IS A NRN
BRANCH SHORTWAVE NOW OVER THE ALEUTIAN ISLANDS WHICH IS FCST TO DIVE
SE ACROSS THE NRN ROCKIES FRI NIGHT AND THEN THROUGH THE PLAINS
STATES ON SAT. ASSOCIATED STRONG MID LEVEL WARM AIR ADVECTION AHEAD
OF THIS SHORTWAVE AND ITS ASSOC SFC LOW WILL SPREAD SNOW EAST INTO
MAINLY THE NORTHWEST HALF OF THE CWA ON SAT. WHILE THE MODELS STILL
PEG THE HEAVIEST SNOW TO OCCUR OVER LAKE SUPERIOR...WILL CONTINUE TO
SHOW SOME LIKELY POPS OVER AND AROUND THE KEWEENAW PENINSULA FOR
SATURDAY. AS THIS SNOW IS OCCURRING...THE NORTHERN SHORTWAVE WILL
CONTINUE TO DIVE SOUTHEAST AND BEGIN TO PHASE WITH THE REMNANTS OF
THE SW CONUS UPPER LOW WHICH WILL LEAD TO BOTH FEATURES EJECTING
NORTHEAST THROUGH THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO
SUNDAY. THE 00Z ECMWF...GFS AND NAM ALL TRENDING DEEPER AND FARTHER
WEST WITH RESULTING SFC LOW WHICH BLEND OF THESE MODELS SHOW A TRACK
THROUGH SRN LWR MI TO NEAR GEORGIAN BAY BY 12Z SUNDAY. THE GEM-NH
MEANWHILE AFTER SHOWING A SIMILAR TRACK TO THE 00Z ECMWF/GFS BLEND
HAS NOW TRENDED FARTHER EAST THROUGH SE LOWER MI INTO ERN ONTARIO.
IF THE LATEST GFS/ECMWF SOLNS HOLD TRUE THIS WOULD MEAN A GREATER
POTENTIAL FOR SYNOPTIC PCPN TO SPREAD INTO UPPER MI...ESPECIALLY THE
EAST HALF...ALONG WITH A GREATER POTENTIAL FOR NORTH FLOW LAKE
ENHANCED SNOW ON THE BACKSIDE OF THE SYSTEM. WILL LIKELY NEED TO
TREND POPS UPWARD ACROSS THE CWA AND ESPECIALLY ALONG LAKE SUPERIOR
ZONES WITH A GREATER POTENTIAL FOR LAKE ENHANCED SNOW SAT NIGHT INTO
SUNDAY. WINDS WILL ALSO RAMP UP WITH TIGHTER GRADIENT ON BACKSIDE OF
SYSTEM WHICH WILL ALSO RESULT IN MORE BLOWING SNOW. WILL HIGHLIGHT
POTENTIAL FOR MODERATE SNOW AND BLOWING SNOW IN HWO...ESPECIALLY
ALONG LAKE SUPERIOR AND THE EAST HALF OF THE CWA FOR SAT NIGHT INTO
SUNDAY EVENING.
LATE SUNDAY NIGHT INTO MONDAY NIGHT...WEAKENING PRES GRADIENT WILL
ALLOW WINDS TO DIMINISH ESPECIALLY OVER THE INTERIOR. WINDS WILL
ALSO BE BACKING MORE WESTERLY ESPECIALLY BY MONDAY IN ADVANCE OF
STRONG SFC HIGH PRES RDG BUILDING IN FROM THE NRN PLAINS...SO EXPECT
LES TO EVENTUALLY BECOME MORE CONFINED TO KEWEENAW AND FAR ERN
SHORELINE AREAS OF THE CWA MONDAY AFTERNOON INTO MON NIGHT. WITH
HEART OF COLDEST AIR (850 MB TEMPS OF -26 TO -28C) COMING ACROSS THE
UPPER LAKES...EXPECT VERY COLD TEMPS SUN NIGHT AND MONDAY. EXPECT
MUCH OF THE INTERIOR CWA TO FALL BLO ZERO AND WOULD NOT BE SURPRISED
TO SEE SOME WESTERN INTERIOR LOCATIONS FALL WELL INTO THE TEENS BLO
ZERO... ESPECIALLY ALONG THE WI BORDER. HIGHS MONDAY WILL REMAIN
VERY COLD WITH READINGS RANGING FROM THE SINGLE DIGITS BLO ZERO
WESTERN INTERIOR TO THE SINGLE DIGITS ABV ZERO EAST AND ALONG THE
GREAT LAKES.
TUESDAY INTO WEDNESDAY...MODELS IN REASONABLY GOOD AGREEMENT SHOWING
ANOTHER CLIPPER SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY WITH ANOTHER REINFORCING SHOT OF ARCTIC AIR (8H TEMPS FALL
AGAIN TO -28C TO -30C) AS WINDS VEER TO THE NW. THIS WILL BRING LES
FARTHER INLAND AGAIN AFFECTING THE NRN TIER AND ERN HALF COUNTIES
FROM LATE TUE THROUGH WED. LOOK LIKE ONLY THE FAR SOUTH CENTRAL
WOULD ESCAPE THE LES. WITH SUCH A COLD ARCTIC AIRMASS FCST THE DGZ
WILL GET SQUASHED NEAR THE LAKE SFC WHICH WILL LIKELY RESULT IN
SMALLER FLAKE SIZE. THIS WILL LIMIT LES ACCUMULATION BUT AT SAME
TIME WILL BE MORE EFFECTIVE FOR REDUCING VSBY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 1243 PM EST THU JAN 1 2015
COLD FRONT HAS MADE IT THROUGH KCMX AND WILL IMPACT KIWD AND KSAW
WITH A PERIOD OF SNOW SHOWERS AND BLOWING SNOW THIS AFTN. AT KIWD
AND KSAW...GENERALLY THE CIGS WILL BE MVFR INTO TONIGHT. VSBY WILL
BE IFR OR MVFR...BUT WILL BEGIN TO IMPROVE BY EARLY EVENING AS DRIER
AIR ERODES THE LAKE EFFECT SNOW SHOWERS. WILL SEE IMPROVEMENT TO VFR
LATE TONIGHT INTO FRIDAY AT KIWD AND KSAW. AT KCMX...PERSISTENT WNW-
NW FLOW OFF LK SUPERIOR WILL KEEP LAKE EFFECT SNOW SHOWERS WITH IFR
TO MVFR VSBY THROUGH THE PERIOD. STRONGEST WINDS WITH BLSN THIS
AFTN...THEN WINDS DIMINISH SIGNIFICANTLY THIS EVENING AND OVERNIGHT
TONIGHT. &&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 AM EST THU JAN 1 2015
A LOW OVER S HUDSON BAY WILL SHIFT INTO N QUEBEC FRIDAY MORNING. THE
TROUGH EXTENDING FROM THIS LOW ACROSS LAKE SUPERIOR WILL SLOWLY
WEAKEN. AS A RESULT...EXPECT THE GALES OF 35-40KTS TO SLOWLY
DIMINISH TOO. WHILE HEAVY FREEZING SPRAY HAS DIMINISHED THIS
MORNING...IT WILL PICK UP AGAIN OVER N LAKE SUPERIOR THIS
AFTERNOON-EVENING.
HIGH PRESSURE SINKING ACROSS MINNESOTA THIS EVENING WILL STRETCH
FROM THE GREAT LAKES THROUGH THE OHIO VALLEY ON FRIDAY...AND EXIT TO
SOUTHERN QUEBEC AND THE NEW ENGLAND STATES FRIDAY NIGHT. EXPECT A
LOW ACROSS THE DAKOTAS FRIDAY NIGHT TO CONSOLIDATE WITH AN
ADDITIONAL LOW ACROSS THE MISSISSIPPI VALLEY. THE NEW LOW WILL MOVE
NE AND DEEPEN ACROSS LOWER MICHIGAN AND LAKE HURON SATURDAY
NIGHT...AND EXIT S QUEBEC ON SUNDAY. THIS WILL BRING A TROUGH
SATURDAY NIGHT INTO SUNDAY FOR LAKE SUPERIOR. N-NW GALES OF 35 TO
NEAR 40KTS WILL AGAIN BE POSSIBLE SUNDAY INTO SUNDAY EVENING. BY
MONDAY...A RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER
MISSISSIPPI VALLEY. HEAVY FREEZING SPRAY WILL ALSO RETURN AS A COLD
RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER MISSISSIPPI VALLEY
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 3 AM EST FRIDAY FOR LSZ263-
264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KF
LONG TERM...VOSS
AVIATION...JLA
MARINE...KF
AREA FORECAST DISCUSSION...UPDATED
NWS MARQUETTE MI
1107 AM EST THU JAN 1 2015
.UPDATE...
ISSUED AT 1107 AM EST THU JAN 1 2015
WIDESPREAD NOAA WEATHER RADIO OUTAGE ACROSS UPR MICHIGAN CONTINUES
AT THIS HOUR DUE TO LARGER SCALE COMMS OUTAGE WITH VERIZON.
SHORTWAVE WITH WIDEPSREAD LGT SNOW IS EXITING EASTERN CWA. SFC
COLD FRONT IS FINALLY STARTING TO SINK ACROSS SOUTHERN HALF OF LK
SUPERIOR THOUGH IT IS TAKING ITS TIME IN DOING SO. LES OVER THE
KEWEENAW THIS MORNING HAS BEEN HEAVY WITH 1+ INCH PER HOUR RATES.
EXPECT LES TO BECOME LESS FOCUSED THOUGH THROUGH MIDDAY AS WINDS
SHIFT FROM THE STRONG CONVERGENT WESTERLY FLOW TO A MORE SHEARED
NORTHWEST FLOW BEHIND THE COLD FRONT. LAKE EFFECT SNOW ADVISORY
SET TO EXPIRE AT 18Z TODAY FOR NORTHERN HOUGHTON AND KEWEENAW
COUNTIES. BASED ON EXPECTED TRENDS IN LES AND WIND THAT LOOKS GOOD
AND WILL NOT MAKE ANY EXTENSIONS ATTM.
ATTN THEN TURNS TO FROPA OVER EASTERN CWA EARLY TO MID AFTN. EXPECT
DECENT CONVERGENCE BAND TO FIRST AFFECT SNOW BELTS EAST OF MARQUETTE
THEN NW FLOW LES WILL DEVELOP. RAP SOUNDINGS INDICATE INVERSIONS TO
7-8KFT WITH TEMPS AROUND -20C AT INVERSION TOP THROUGH EARLY
EVENING. MIXED LAYER WINDS 25-35 KTS WILL RESULT IN WINDY CONDITIONS
AFTER FROPA WITH BLSN/POOR VSBY. WOULD EXPECT SNOWFALL RATES BTWN
0.5-1.0 INCH PER HOUR THIS AFTN INTO THE EARLY EVENING. MUCH OF THE
CONVECTIVE LAYER IS WITHIN THE DGZ...SO SLR/S WILL BE WELL OVER
20:1.
OPTED TO ISSUE A LAKE EFFECT SNOW ADVISORY FOR ALGER...NORTHERN
SCHOOLCRAFT...AND LUCE COUNTIES THROUGH THE EVENING. SNOW AND BLSN
WILL MAKE TRAVEL DIFFICULT INTO THE EARLY EVENING WITH VSBY DOWN TO
1/4SM AT TIMES...AND SNOW AMOUNTS WILL BE BOOSTED BY HIGHER SLR/S
AND DECENTLY HIGH INVERSIONS. IN WAKE OF FROPA LATE THIS EVENING AND
OVERNIGHT TONIGHT...EXPECT DIMINISHING LES AS INVERSIONS FALL BLO
5KFT...BUT DIMINISHING WINDS AND MOST OF THE CONVECTIVE LAYER WITHIN
THE DGZ WILL STILL BOOST SNOW AMOUNTS. EXPECT SNOW TOTALS TODAY INTO
THIS EVENING OF 2 TO 4 INCHES AND ANOTHER 1 TO 3 INCHES LATER THIS
EVENING INTO THE OVERNIGHT.
UPDATED WSW STATEMENT ALREADY OUT. COORD WITH APX ON THE LAKE EFFECT
SNOW ADVISORY FOR LUCE COUNTY.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 546 AM EST THU JAN 1 2015
THE STACKED SFC-500MB LOW OVER S HUDSON BAY WILL WEAKEN SLIGHTLY AND
DRIFT OVER N QUEBEC OVERNIGHT TONIGHT. THIS WILL KEEP THE UPPER
GREAT LAKES IN NW FLOW ALOFT WITH SEVERAL SMALL WAVES SHIFTING
ACROSS THE AREA. A DOMINANT SFC TROUGH/COLD FRONT HOVERING NEAR THE
N MN BORDER WILL SINK ACROSS UPPER MI THROUGH THE DAY TODAY.
THIS...AND AN SHORTWAVE PUSHING ACROSS THE AREA WILL ALLOW FOR SOME
INTENSIFICATION TO SNOW SHOWERS THIS AFTERNOON. AS A RESULT...WILL
KEEP THE HIGH CHANCE POPS GOING ACROSS THE AREA AROUND 18Z...BEFORE
DIMINISHING THEM AGAIN TO ALONG THE LAKE SUPERIOR SHORELINE THIS
EVENING. 850MB TEMPS WILL FALL FROM THE MORNING READINGS OF -12 TO
-15C TO -18 TO -21C BY DAYBREAK FRIDAY.
AS FOR SPECIFICS...
LES CONTINUES ACROSS THE KEWEENAW PENINSULA...WITH A DOMINANT BAND
STRETCHING ACROSS LAKE SUPERIOR TO NEAR WHITEFISH POINT. LOOK FOR
THE EASTERN LAKE SUPERIOR BAND TO SLOWLY SINK S ONSHORE AS THE
CONVERGENT W TO SW WINDS KEEPING IT JUST OFF THE SHORE RELAX AND NW
WINDS OFF THE LAKE WIN OUT LATER THIS MORNING. THIS WILL PUSH THE
BAND OVER N LUCE COUNTY...WITH 1-3 INCHES OF SNOW FCST FOR MUCH OF
LUCE COUNTY. ANOTHER 1-3 INCHES IS EXPECTED TONIGHT WITH BETTER
CONVERGENCE NEAR WHITEFISH POINT.
WILL KEEP THE LES ADVISORY FOR SNOW AND BLOWING/DRIFTING SNOW GOING
ACROSS THE KEWEENAW PENINUSLA. EXPECT ANY DOMINANT BANDS...HIGHER
SNOW AMOUNTS...TO DRIFT AROUND AND S OF CMX...WITH NEW SNOW TODAY OF
1-3 INCHES.
EXPECT ANOTHER COLD NIGHT...WITH LOWS GENERALLY IN THE SINGLE DIGITS
BELOW AND ABOVE ZERO...WARMEST WHERE CLOUDS AND SNOW SHOWERS LINGER
ALONG LAKE SUPERIOR.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EST THU JAN 1 2015
PERSISTENT RIDGING OVER THE EASTERN PACIFIC/NAMERICA WEST COAST
REGION WILL MAINTAIN A BROAD UPPER TROUGH OVER MUCH OF CANADA AND
THE GREAT LAKES REGION THROUGH THE FIRST WEEK OF JANUARY RESULTING
IN BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW FOR
UPPER MI.
BEGINNING FRIDAY...MODEL CONSENSUS SUGGESTS WINDS WL BACK MORE
WESTERLY AGAIN AS SFC RDG AXIS ADVANCES ACROSS AREA FROM THE NRN
PLAINS. THE GENERALLY WEAK WRLY FLOW ALONG WITH ENHANCED LOW-LVL
CONVERGENCE FROM LAND BREEZES WL HELP FOCUS GENERALLY LIGHT LAKE
EFFECT SNOW ACROSS THE KEWEENAN PENINSULA AND THE FAR ERN SHORELINE
OF THE CWA AS INVERSION BASES CRASH BLO 5KFT WITH DRY AIR NOTED
BENEATH THE INVERSION. SINCE MUCH OF THE DGZ IN STILL WITHIN THE
CLOUD LAYER...LES BANDS COULD YIELD 1-2 INCHES OF FLUFFY
ACCUMULATION DURING THE DAY. WAA CLOUDS AHEAD OF SHORTWAVE MOVING IN
FROM THE NRN PLAINS WILL LIMIT RADIATIONAL COOLING FRIDAY NIGHT BUT
TEMPS SHOULD STILL APPROACH ZERO OR MAYBE EVEN DIP BLO ZERO AT A FEW
OF THE TYPICAL COLDER LOCATIONS OVER THE WESTERN INTERIOR.
THIS WEEKEND...FOCUS IS ON PHASING/INTERACTION OF SPLIT FLOW. TWO
FEATURES WILL COME INTO PLAY...ONE WILL BE THE REMNANTS OF A CLOSED
LOW NOW PRODUCING SNOW OVER THE SW CONUS...AND THE SECOND IS A NRN
BRANCH SHORTWAVE NOW OVER THE ALEUTIAN ISLANDS WHICH IS FCST TO DIVE
SE ACROSS THE NRN ROCKIES FRI NIGHT AND THEN THROUGH THE PLAINS
STATES ON SAT. ASSOCIATED STRONG MID LEVEL WARM AIR ADVECTION AHEAD
OF THIS SHORTWAVE AND ITS ASSOC SFC LOW WILL SPREAD SNOW EAST INTO
MAINLY THE NORTHWEST HALF OF THE CWA ON SAT. WHILE THE MODELS STILL
PEG THE HEAVIEST SNOW TO OCCUR OVER LAKE SUPERIOR...WILL CONTINUE TO
SHOW SOME LIKELY POPS OVER AND AROUND THE KEWEENAW PENINSULA FOR
SATURDAY. AS THIS SNOW IS OCCURRING...THE NORTHERN SHORTWAVE WILL
CONTINUE TO DIVE SOUTHEAST AND BEGIN TO PHASE WITH THE REMNANTS OF
THE SW CONUS UPPER LOW WHICH WILL LEAD TO BOTH FEATURES EJECTING
NORTHEAST THROUGH THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO
SUNDAY. THE 00Z ECMWF...GFS AND NAM ALL TRENDING DEEPER AND FARTHER
WEST WITH RESULTING SFC LOW WHICH BLEND OF THESE MODELS SHOW A TRACK
THROUGH SRN LWR MI TO NEAR GEORGIAN BAY BY 12Z SUNDAY. THE GEM-NH
MEANWHILE AFTER SHOWING A SIMILAR TRACK TO THE 00Z ECMWF/GFS BLEND
HAS NOW TRENDED FARTHER EAST THROUGH SE LOWER MI INTO ERN ONTARIO.
IF THE LATEST GFS/ECMWF SOLNS HOLD TRUE THIS WOULD MEAN A GREATER
POTENTIAL FOR SYNOPTIC PCPN TO SPREAD INTO UPPER MI...ESPECIALLY THE
EAST HALF...ALONG WITH A GREATER POTENTIAL FOR NORTH FLOW LAKE
ENHANCED SNOW ON THE BACKSIDE OF THE SYSTEM. WILL LIKELY NEED TO
TREND POPS UPWARD ACROSS THE CWA AND ESPECIALLY ALONG LAKE SUPERIOR
ZONES WITH A GREATER POTENTIAL FOR LAKE ENHANCED SNOW SAT NIGHT INTO
SUNDAY. WINDS WILL ALSO RAMP UP WITH TIGHTER GRADIENT ON BACKSIDE OF
SYSTEM WHICH WILL ALSO RESULT IN MORE BLOWING SNOW. WILL HIGHLIGHT
POTENTIAL FOR MODERATE SNOW AND BLOWING SNOW IN HWO...ESPECIALLY
ALONG LAKE SUPERIOR AND THE EAST HALF OF THE CWA FOR SAT NIGHT INTO
SUNDAY EVENING.
LATE SUNDAY NIGHT INTO MONDAY NIGHT...WEAKENING PRES GRADIENT WILL
ALLOW WINDS TO DIMINISH ESPECIALLY OVER THE INTERIOR. WINDS WILL
ALSO BE BACKING MORE WESTERLY ESPECIALLY BY MONDAY IN ADVANCE OF
STRONG SFC HIGH PRES RDG BUILDING IN FROM THE NRN PLAINS...SO EXPECT
LES TO EVENTUALLY BECOME MORE CONFINED TO KEWEENAW AND FAR ERN
SHORELINE AREAS OF THE CWA MONDAY AFTERNOON INTO MON NIGHT. WITH
HEART OF COLDEST AIR (850 MB TEMPS OF -26 TO -28C) COMING ACROSS THE
UPPER LAKES...EXPECT VERY COLD TEMPS SUN NIGHT AND MONDAY. EXPECT
MUCH OF THE INTERIOR CWA TO FALL BLO ZERO AND WOULD NOT BE SURPRISED
TO SEE SOME WESTERN INTERIOR LOCATIONS FALL WELL INTO THE TEENS BLO
ZERO... ESPECIALLY ALONG THE WI BORDER. HIGHS MONDAY WILL REMAIN
VERY COLD WITH READINGS RANGING FROM THE SINGLE DIGITS BLO ZERO
WESTERN INTERIOR TO THE SINGLE DIGITS ABV ZERO EAST AND ALONG THE
GREAT LAKES.
TUESDAY INTO WEDNESDAY...MODELS IN REASONABLY GOOD AGREEMENT SHOWING
ANOTHER CLIPPER SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY WITH ANOTHER REINFORCING SHOT OF ARCTIC AIR (8H TEMPS FALL
AGAIN TO -28C TO -30C) AS WINDS VEER TO THE NW. THIS WILL BRING LES
FARTHER INLAND AGAIN AFFECTING THE NRN TIER AND ERN HALF COUNTIES
FROM LATE TUE THROUGH WED. LOOK LIKE ONLY THE FAR SOUTH CENTRAL
WOULD ESCAPE THE LES. WITH SUCH A COLD ARCTIC AIRMASS FCST THE DGZ
WILL GET SQUASHED NEAR THE LAKE SFC WHICH WILL LIKELY RESULT IN
SMALLER FLAKE SIZE. THIS WILL LIMIT LES ACCUMULATION BUT AT SAME
TIME WILL BE MORE EFFECTIVE FOR REDUCING VSBY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z FRIDAY MORNING)
ISSUED AT 739 AM EST THU JAN 1 2015
A COLD FRONT ACROSS THE AREA WILL HELP KEEP SNOW SHOWERS GOING AT
ALL 3 SITES. REDUCED VIS DOWN TO LIFR AND IFR WILL REMAIN AT IWD UP
THROUGH CMX...GIVEN THE FAVORABLE W WINDS THAT WILL BE BECOME MORE
NORTHWESTERLY BY LATE MORNING/EARLY AFTERNOON. REMAINED MOST
PESSIMISTIC FOR CMX AS SOUNDINGS INDICATE LOW LEVEL MOISTURE TRAPPED
BELOW 5KFT THROUGH THE END OF THE PERIOD. BLSN WILL SLOWLY COME TO
AN END TODAY AS THE STRONG LOW RESPONSIBLE FOR THE STRONG WINDS
DIMINISHES AND EXITS HUDSON BAY INTO QUEBEC. LOOK FOR VFR CEILINGS
TO RETURN BEHIND THE SFC TROUGH BY 01Z FRIDAY IF NOT EARLIER...AND
END BY AROUND 05Z /OR POSSIBLY A BIT LATER/ AT IWD AS SFC WINDS
BECOME MORE OUT OF THE W...WITH THE MAIN BANDS OF LAKE EFFECT SNOW
SHIFTING N OF THE SITE.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 AM EST THU JAN 1 2015
A LOW OVER S HUDSON BAY WILL SHIFT INTO N QUEBEC FRIDAY MORNING. THE
TROUGH EXTENDING FROM THIS LOW ACROSS LAKE SUPERIOR WILL SLOWLY
WEAKEN. AS A RESULT...EXPECT THE GALES OF 35-40KTS TO SLOWLY
DIMINISH TOO. WHILE HEAVY FREEZING SPRAY HAS DIMINISHED THIS
MORNING...IT WILL PICK UP AGAIN OVER N LAKE SUPERIOR THIS
AFTERNOON-EVENING.
HIGH PRESSURE SINKING ACROSS MINNESOTA THIS EVENING WILL STRETCH
FROM THE GREAT LAKES THROUGH THE OHIO VALLEY ON FRIDAY...AND EXIT TO
SOUTHERN QUEBEC AND THE NEW ENGLAND STATES FRIDAY NIGHT. EXPECT A
LOW ACROSS THE DAKOTAS FRIDAY NIGHT TO CONSOLIDATE WITH AN
ADDITIONAL LOW ACROSS THE MISSISSIPPI VALLEY. THE NEW LOW WILL MOVE
NE AND DEEPEN ACROSS LOWER MICHIGAN AND LAKE HURON SATURDAY
NIGHT...AND EXIT S QUEBEC ON SUNDAY. THIS WILL BRING A TROUGH
SATURDAY NIGHT INTO SUNDAY FOR LAKE SUPERIOR. N-NW GALES OF 35 TO
NEAR 40KTS WILL AGAIN BE POSSIBLE SUNDAY INTO SUNDAY EVENING. BY
MONDAY...A RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER
MISSISSIPPI VALLEY. HEAVY FREEZING SPRAY WILL ALSO RETURN AS A COLD
RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER MISSISSIPPI VALLEY
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE EFFECT SNOW ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR MIZ006-
007-085.
LAKE SUPERIOR...
GALE WARNING UNTIL 6 PM EST THIS EVENING FOR LSZ266-267.
HEAVY FREEZING SPRAY WARNING UNTIL 3 AM EST FRIDAY FOR LSZ263-
264.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SHORT TERM...KF
LONG TERM...VOSS
AVIATION...KF
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
501 AM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 429 PM EST WED DEC 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM
NW CANADA INTO THE GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO BC. A SHORTWAVE TROUGH WAS MOVING
THROUGH UPPER MI WITH ANOTHER WEAKER SHRTWV UPSTREAM OVER MANITOBA.
ANOTHER CLIPPER SHRTWV WAS FARTHER UPSTREAM OVER NW SASK. AT THE
SFC...STRONG WEST WINDS PREVAILED ACROSS THE REGION BETWEEN A 988 MB
LOW NEAR HUDSON BAY AND 1036 MB ARCTIC HIGH PRES INTO THE SRN
PLAINS. THE STRONGEST WINDS THIS MORNING INTO EARLY AFTERNOON ACROSS
LAKE SUPERIOR OCCURRED AS THE STRONGER PRES FALLS SLID THROUGH NRN
ONTARIO. WITH 850 MB TEMPS AROUND -19C AND CONVERGENT WRLY FLOW
DEVELOPING LES HAS INCREASED ACROSS THE KEWEENAW AS WINDS VEERED
FROM SW TO W.
TONIGHT...EXPECT THE STRONGEST LOW LEVEL CONV SUPPORTING LES TO
REMAIN OVER THE KEWEENAW. EVEN WITH A FAVORABLE POSITION OF THE DGZ
IN THE CLOUD LAYER...THE STRONGER WINDS WILL CREATE ENOUGH
COMPACTION/FRACTURING TO LIMIT SLR VALUES CLOSER TO 20/1. SO OVERALL
ACCUMULATIONS TONIGHT IN THE 2 TO 5 INCH RANGE ARE EXPECTED. WINDS
GUSTING INTO THE 30 TO 40 MPH RANGE WILL ALSO CONTINUE TO PRODUCE
CONSIDERABLE BLOWING AND DRIFTING SNOW IN OPEN AREAS WHERE OCNL
WHITEOUT CONDITIONS ARE POSSIBLE. WINDS ARE EXPECTED TO DIMINISH
OVERNIGHT REDUCING THE BLSN HAZARDS.
THU...THE NRN SASK SHRTWV TROUGH WILL BRUSH THE AREA WITH ENOUGH
700-500 MB QVECTOR CONV AND 800-600 MB FGEN TO SUPPORT AN AREA OF
LIGHT SNOW FROM NRN MN INTO NRN WI AND UPPER MI. WITH THE LACK OF
SIGNFICANT MOISTURE INFLOW/AVAILABILITY...SNOW AMOUNTS OF A HALF
INCH OR LESS ARE EXPECTED. HOWEVER...THE DEEPER MOISTURE WITH
INCREASING INVERSION HEIGHTS INTO THE AREA WILL SUPPORT GREATER LES
INTENSITY FOR THE W TO WNW FLOW LES SNOW BELTS. SINCE THE STRONGER
LOW LEVEL CONV IS EXPECTED TO SHIFT SOUTHWARD OVERALL SNOW AMOUNTS
SHOULD REMAIN IN THE 1 TO 3 INCH RANGE.
.LONG TERM...(FRIDAY THROUGH WEDNESDAY)
ISSUED AT 501 AM EST THU JAN 1 2015
PERSISTENT RIDGING OVER THE EASTERN PACIFIC/NAMERICA WEST COAST
REGION WILL MAINTAIN A BROAD UPPER TROUGH OVER MUCH OF CANADA AND
THE GREAT LAKES REGION THROUGH THE FIRST WEEK OF JANUARY RESULTING
IN BELOW NORMAL TEMPERATURES AND PERIODS OF LAKE EFFECT SNOW FOR
UPPER MI.
BEGINNING FRIDAY...MODEL CONSENSUS SUGGESTS WINDS WL BACK MORE
WESTERLY AGAIN AS SFC RDG AXIS ADVANCES ACROSS AREA FROM THE NRN
PLAINS. THE GENERALLY WEAK WRLY FLOW ALONG WITH ENHANCED LOW-LVL
CONVERGENCE FROM LAND BREEZES WL HELP FOCUS GENERALLY LIGHT LAKE
EFFECT SNOW ACROSS THE KEWEENAN PENINSULA AND THE FAR ERN SHORELINE
OF THE CWA AS INVERSION BASES CRASH BLO 5KFT WITH DRY AIR NOTED
BENEATH THE INVERSION. SINCE MUCH OF THE DGZ IN STILL WITHIN THE
CLOUD LAYER...LES BANDS COULD YIELD 1-2 INCHES OF FLUFFY
ACCUMULATION DURING THE DAY. WAA CLOUDS AHEAD OF SHORTWAVE MOVING IN
FROM THE NRN PLAINS WILL LIMIT RADIATIONAL COOLING FRIDAY NIGHT BUT
TEMPS SHOULD STILL APPROACH ZERO OR MAYBE EVEN DIP BLO ZERO AT A FEW
OF THE TYPICAL COLDER LOCATIONS OVER THE WESTERN INTERIOR.
THIS WEEKEND...FOCUS IS ON PHASING/INTERACTION OF SPLIT FLOW. TWO
FEATURES WILL COME INTO PLAY...ONE WILL BE THE REMNANTS OF A CLOSED
LOW NOW PRODUCING SNOW OVER THE SW CONUS...AND THE SECOND IS A NRN
BRANCH SHORTWAVE NOW OVER THE ALEUTIAN ISLANDS WHICH IS FCST TO DIVE
SE ACROSS THE NRN ROCKIES FRI NIGHT AND THEN THROUGH THE PLAINS
STATES ON SAT. ASSOCIATED STRONG MID LEVEL WARM AIR ADVECTION AHEAD
OF THIS SHORTWAVE AND ITS ASSOC SFC LOW WILL SPREAD SNOW EAST INTO
MAINLY THE NORTHWEST HALF OF THE CWA ON SAT. WHILE THE MODELS STILL
PEG THE HEAVIEST SNOW TO OCCUR OVER LAKE SUPERIOR...WILL CONTINUE TO
SHOW SOME LIKELY POPS OVER AND AROUND THE KEWEENAW PENINSULA FOR
SATURDAY. AS THIS SNOW IS OCCURRING...THE NORTHERN SHORTWAVE WILL
CONTINUE TO DIVE SOUTHEAST AND BEGIN TO PHASE WITH THE REMNANTS OF
THE SW CONUS UPPER LOW WHICH WILL LEAD TO BOTH FEATURES EJECTING
NORTHEAST THROUGH THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO
SUNDAY. THE 00Z ECMWF...GFS AND NAM ALL TRENDING DEEPER AND FARTHER
WEST WITH RESULTING SFC LOW WHICH BLEND OF THESE MODELS SHOW A TRACK
THROUGH SRN LWR MI TO NEAR GEORGIAN BAY BY 12Z SUNDAY. THE GEM-NH
MEANWHILE AFTER SHOWING A SIMILAR TRACK TO THE 00Z ECMWF/GFS BLEND
HAS NOW TRENDED FARTHER EAST THROUGH SE LOWER MI INTO ERN ONTARIO.
IF THE LATEST GFS/ECMWF SOLNS HOLD TRUE THIS WOULD MEAN A GREATER
POTENTIAL FOR SYNOPTIC PCPN TO SPREAD INTO UPPER MI...ESPECIALLY THE
EAST HALF...ALONG WITH A GREATER POTENTIAL FOR NORTH FLOW LAKE
ENHANCED SNOW ON THE BACKSIDE OF THE SYSTEM. WILL LIKELY NEED TO
TREND POPS UPWARD ACROSS THE CWA AND ESPECIALLY ALONG LAKE SUPERIOR
ZONES WITH A GREATER POTENTIAL FOR LAKE ENHANCED SNOW SAT NIGHT INTO
SUNDAY. WINDS WILL ALSO RAMP UP WITH TIGHTER GRADIENT ON BACKSIDE OF
SYSTEM WHICH WILL ALSO RESULT IN MORE BLOWING SNOW. WILL HIGHLIGHT
POTENTIAL FOR MODERATE SNOW AND BLOWING SNOW IN HWO...ESPECIALLY
ALONG LAKE SUPERIOR AND THE EAST HALF OF THE CWA FOR SAT NIGHT INTO
SUNDAY EVENING.
LATE SUNDAY NIGHT INTO MONDAY NIGHT...WEAKENING PRES GRADIENT WILL
ALLOW WINDS TO DIMINISH ESPECIALLY OVER THE INTERIOR. WINDS WILL
ALSO BE BACKING MORE WESTERLY ESPECIALLY BY MONDAY IN ADVANCE OF
STRONG SFC HIGH PRES RDG BUILDING IN FROM THE NRN PLAINS...SO EXPECT
LES TO EVENTUALLY BECOME MORE CONFINED TO KEWEENAW AND FAR ERN
SHORELINE AREAS OF THE CWA MONDAY AFTERNOON INTO MON NIGHT. WITH
HEART OF COLDEST AIR (850 MB TEMPS OF -26 TO -28C) COMING ACROSS THE
UPPER LAKES...EXPECT VERY COLD TEMPS SUN NIGHT AND MONDAY. EXPECT
MUCH OF THE INTERIOR CWA TO FALL BLO ZERO AND WOULD NOT BE SURPRISED
TO SEE SOME WESTERN INTERIOR LOCATIONS FALL WELL INTO THE TEENS BLO
ZERO... ESPECIALLY ALONG THE WI BORDER. HIGHS MONDAY WILL REMAIN
VERY COLD WITH READINGS RANGING FROM THE SINGLE DIGITS BLO ZERO
WESTERN INTERIOR TO THE SINGLE DIGITS ABV ZERO EAST AND ALONG THE
GREAT LAKES.
TUESDAY INTO WEDNESDAY...MODELS IN REASONABLY GOOD AGREEMENT SHOWING
ANOTHER CLIPPER SHORTWAVE MOVING ACROSS THE UPPER GREAT LAKES ON
TUESDAY WITH ANOTHER REINFORCING SHOT OF ARCTIC AIR (8H TEMPS FALL
AGAIN TO -28C TO -30C) AS WINDS VEER TO THE NW. THIS WILL BRING LES
FARTHER INLAND AGAIN AFFECTING THE NRN TIER AND ERN HALF COUNTIES
FROM LATE TUE THROUGH WED. LOOK LIKE ONLY THE FAR SOUTH CENTRAL
WOULD ESCAPE THE LES. WITH SUCH A COLD ARCTIC AIRMASS FCST THE DGZ
WILL GET SQUASHED NEAR THE LAKE SFC WHICH WILL LIKELY RESULT IN
SMALLER FLAKE SIZE. THIS WILL LIMIT LES ACCUMULATION BUT AT SAME
TIME WILL BE MORE EFFECTIVE FOR REDUCING VSBY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1209 AM EST THU JAN 1 2015
WINDS HAVE BECOME MORE WESTERLY OVER THE WESTERN U.P. WITH THE
PASSAGE OF A WEAK SHORTWAVE. WESTERLY FLOW HAS RESULTED IN ENHANCED
LES AT KCMX AT TIMES...WITH VSBYS OCCASIONALLY FALLING TO LIFR DUE
TO SNOW AND BLOWING SNOW WHILE CIGS LOWER TO IFR. AS WINDS VEER TO
NW DURING THE LATE MORNING HOURS...EXPECT KCMX CONDITIONS TO IMPROVE
WITH MVFR PREVAILING BY MIDDAY. KIWD TO SEE LES AND BLSN IN NW FLOW
WITH MAINLY MVFR CONDITIONS THERE...WITH BRIEF PERIODS OF IFR DUE TO
HEAVIER LES. KSAW TO SEE MVFR CONDITIONS AS NW DOWNSLOPE THERE NOT
FAVORABLE FOR LOWER CIGS/VSBYS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 AM EST THU JAN 1 2015
A LOW OVER S HUDSON BAY WILL SHIFT INTO N QUEBEC FRIDAY MORNING. THE
TROUGH EXTENDING FROM THIS LOW ACROSS LAKE SUPERIOR WILL SLOWLY
WEAKEN. AS A RESULT...EXPECT THE GALES OF 35-40KTS TO SLOWLY
DIMINISH TOO. WHILE HEAVY FREEZING SPRAY HAS DIMINISHED THIS
MORNING...IT WILL PICK UP AGAIN OVER N LAKE SUPERIOR THIS
AFTERNOON-EVENING.
HIGH PRESSURE SINKING ACROSS MINNESOTA THIS EVENING WILL STRETCH
FROM THE GREAT LAKES THROUGH THE OHIO VALLEY ON FRIDAY...AND EXIT TO
SOUTHERN QUEBEC AND THE NEW ENGLAND STATES FRIDAY NIGHT. EXPECT A
LOW ACROSS THE DAKOTAS FRIDAY NIGHT TO CONSOLIDATE WITH AN
ADDITIONAL LOW ACROSS THE MISSISSIPPI VALLEY. THE NEW LOW WILL MOVE
NE AND DEEPEN ACROSS LOWER MICHIGAN AND LAKE HURON SATURDAY
NIGHT...AND EXIT S QUEBEC ON SUNDAY. THIS WILL BRING A TROUGH
SATURDAY NIGHT INTO SUNDAY FOR LAKE SUPERIOR. N-NW GALES OF 35 TO
NEAR 40KTS WILL AGAIN BE POSSIBLE SUNDAY INTO SUNDAY EVENING. BY
MONDAY...A RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER
MISSISSIPPI VALLEY. HEAVY FREEZING SPRAY WILL ALSO RETURN AS A COLD
RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER MISSISSIPPI VALLEY
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
241>251-263>265.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 3 AM
EST FRIDAY FOR LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...VOSS
AVIATION...RJT
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
414 AM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 429 PM EST WED DEC 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM
NW CANADA INTO THE GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO BC. A SHORTWAVE TROUGH WAS MOVING
THROUGH UPPER MI WITH ANOTHER WEAKER SHRTWV UPSTREAM OVER MANITOBA.
ANOTHER CLIPPER SHRTWV WAS FARTHER UPSTREAM OVER NW SASK. AT THE
SFC...STRONG WEST WINDS PREVAILED ACROSS THE REGION BETWEEN A 988 MB
LOW NEAR HUDSON BAY AND 1036 MB ARCTIC HIGH PRES INTO THE SRN
PLAINS. THE STRONGEST WINDS THIS MORNING INTO EARLY AFTERNOON ACROSS
LAKE SUPERIOR OCCURRED AS THE STRONGER PRES FALLS SLID THROUGH NRN
ONTARIO. WITH 850 MB TEMPS AROUND -19C AND CONVERGENT WRLY FLOW
DEVELOPING LES HAS INCREASED ACROSS THE KEWEENAW AS WINDS VEERED
FROM SW TO W.
TONIGHT...EXPECT THE STRONGEST LOW LEVEL CONV SUPPORTING LES TO
REMAIN OVER THE KEWEENAW. EVEN WITH A FAVORABLE POSITION OF THE DGZ
IN THE CLOUD LAYER...THE STRONGER WINDS WILL CREATE ENOUGH
COMPACTION/FRACTURING TO LIMIT SLR VALUES CLOSER TO 20/1. SO OVERALL
ACCUMULATIONS TONIGHT IN THE 2 TO 5 INCH RANGE ARE EXPECTED. WINDS
GUSTING INTO THE 30 TO 40 MPH RANGE WILL ALSO CONTINUE TO PRODUCE
CONSIDERABLE BLOWING AND DRIFTING SNOW IN OPEN AREAS WHERE OCNL
WHITEOUT CONDITIONS ARE POSSIBLE. WINDS ARE EXPECTED TO DIMINISH
OVERNIGHT REDUCING THE BLSN HAZARDS.
THU...THE NRN SASK SHRTWV TROUGH WILL BRUSH THE AREA WITH ENOUGH
700-500 MB QVECTOR CONV AND 800-600 MB FGEN TO SUPPORT AN AREA OF
LIGHT SNOW FROM NRN MN INTO NRN WI AND UPPER MI. WITH THE LACK OF
SIGNFICANT MOISTURE INFLOW/AVAILABILITY...SNOW AMOUNTS OF A HALF
INCH OR LESS ARE EXPECTED. HOWEVER...THE DEEPER MOISTURE WITH
INCREASING INVERSION HEIGHTS INTO THE AREA WILL SUPPORT GREATER LES
INTENSITY FOR THE W TO WNW FLOW LES SNOW BELTS. SINCE THE STRONGER
LOW LEVEL CONV IS EXPECTED TO SHIFT SOUTHWARD OVERALL SNOW AMOUNTS
SHOULD REMAIN IN THE 1 TO 3 INCH RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 PM EST WED DEC 31 2014
AN UPPER TROUGH OVER EASTERN CANADA LEAD TO COLD AIR AND LAKE
EFFECT SNOW OVER THE NORTHWEST WIND SNOW BELTS TO START THE PERIOD.
THIS LIGHT TO OCCASIONALLY MODERATE LAKE EFFECT SNOW WILL CONTINUE
IN THOSE NORTHWEST WIND BELTS ON THURSDAY NIGHT...BUT AS THE LOW
LEVEL WINDS BACK LATE THURSDAY NIGHT INTO FRIDAY MORNING...WILL
FOCUS THE POPS/SNOW TO THE WEST-NORTHWEST AREAS ON FRIDAY (AND
WESTERLY AREAS LATE FRIDAY AFTERNOON). WHILE LAKE INDUCED
EQUILIBRIUM LEVELS WILL BE AROUND 8KFT...THERE ARE SOME CONCERNS IN
THE AMOUNT OF MOISTURE AVAILABLE AS SUBSIDENCE AND DRIER AIR ARRIVE
THURSDAY NIGHT FROM A HIGH MOVING SOUTHEAST INTO MINNESOTA.
THUS...WILL STICK WITH A DUSTING TO 3-4IN EVERY 12HRS THROUGH
FRIDAY...WITH THE HIGHEST AMOUNTS OVER THE EAST WITH THE LONGER
FETCH AND SOME INDICATIONS OF A LINGERING TROUGH AIDING
CONVERGENCE TOWARDS WHITEFISH POINT. THE HIGH WILL SHIFT SOUTHEAST
OF THE AREA ON FRIDAY EVENING...BACKING WINDS TO THE SOUTHWEST AND
ONLY LEAVING LAKE EFFECT SNOW OVER THE KEWEENAW FOR FRIDAY NIGHT.
THE FOCUS THEN TURNS TO THE INTERACTION AND PHASING OF THE SPLIT
FLOW FOR THE START OF THE WEEKEND. MODELS SEEM TO COMING INTO
BETTER AGREEMENT ON THE OVERALL IDEA FOR THE WEEKEND...ALTHOUGH
THERE ARE STILL SMALLER DIFFERENCES THAT COULD HAVE AN IMPACT ON
THE AMOUNT OF SNOW SEEN OVER PARTS OF THE U.P. THERE ARE TWO
FEATURES AT PLAY FOR THIS WEEKEND...THE FIRST IS THE REMNANTS OF
THE UPPER LOW PRODUCING SNOW OVER THE SOUTHWEST CONUS TODAY AND THE
SECOND FEATURE IS A SHORTWAVE CURRENTLY OVER THE ALEUTIANS ISLANDS
AND DROPPING SOUTHEAST INTO THE NORTHERN ROCKIES ON FRIDAY NIGHT.
THIS WILL LEAD TO A LOW DEVELOPING IN THE LEE OF THE NORTHERN
ROCKIES AND THEN MOVING EAST INTO THE DAKOTAS AND WESTERN MINNESOTA
BY SATURDAY MORNING. EXPECT SNOW TO SPREAD EAST AHEAD OF THIS LOW
AND INTO THE NORTHWEST HALF OF THE CWA...ASSOCIATED WITH STRONG MID
LEVEL WARM AIR ADVECTION. WHILE THE HEAVIEST SNOW APPEARS TO OCCUR
OVER LAKE SUPERIOR...WILL SHOW SOME LIKELY POPS OVER AND AROUND THE
KEWEENAW PENINSULA FOR SATURDAY. AS THAT IS OCCURRING...THE
NORTHERN SHORTWAVE WILL CONTINUE TO DIVE SOUTHEAST AND PHASE WITH
THE SOUTHERN UPPER LOW AND LEAD TO BOTH EJECTING NORTHEAST THROUGH
THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO SUNDAY. AS
EXPECTED IN THESE PHASING EVENTS...EACH MODEL RUN GIVES A SLIGHTLY
DIFFERENT IDEA ON THE EVOLUTION OF THE PHASED FEATURES AND IN TURN
THE SURFACE FEATURES. OVERALL...THE GENERAL IDEA IS FOR A
STRENGTHENING LOW TO LIFT NORTHEAST THROUGH SOUTHEAST LOWER
MICHIGAN ON SATURDAY NIGHT AND THEN INTO QUEBEC ON SUNDAY. WITH
THAT TRACK...WOULD EXPECT MUCH OF THE SYNOPTIC
FORCING/PRECIPITATION ASSOCIATED WITH THOSE FEATURES TO MISS THE
U.P....BUT WOULD STILL EXPECT AT LEAST SOME LAKE ENHANCEMENT AS THE
WINDS TURN TO THE NORTHWEST BEHIND THE ELONGATED SURFACE TROUGH
STRETCHING NORTH OVER EASTERN LAKE SUPERIOR LATE SATURDAY NIGHT.
INITIALLY...WOULDN/T EXPECT THE LAKE ENHANCEMENT TO AMOUNT TO TOO
HIGH OF SNOWFALL AMOUNTS ON SATURDAY NIGHT...BUT AS MUCH COLDER AIR
MOVES INTO THE AREA (850MB TEMPS FALLING TO -25C BY 00Z MONDAY) AND
THE DEEPER MOISTURE IS STILL PRESENT FROM THE DEPARTING
SYSTEM...WOULD EXPECT THE LAKE ENHANCEMENT/EFFECT SNOW TO TAKE OFF
ON SUNDAY IN THE NORTHWEST WIND SNOW BELTS. WILL TREND POPS UP TO
DEFINITE VALUES DURING THIS PERIOD AND CONTINUE TO MENTION
MODERATE/HEAVY SNOW WORDING IN THE HWO.
BEHIND THE LOW...EXPECT THE FIRST PART OF THE WORK WEEK TO BE VERY
COLD WITH CONTINUED LAKE EFFECT SNOW. THE CANADIAN UPPER TROUGH
WILL SAG SOUTH INTO THE GREAT LAKES REGION AND KEEP THE COLD AIR IN
PLACE (850MB TEMPS IN THE LOW 20C BELOW ZERO)...WITH ANOTHER
SHORTWAVE MOVING THROUGH ON MONDAY NIGHT POTENTIALLY PULLING 850MB
TEMPERATURES CLOSE TO -30C FOR TUESDAY. THAT WILL LEAD TO VERY COLD
HIGH TEMPERATURES FOR MONDAY/TUESDAY...WITH SOME LOCATIONS OVER THE
INTERIOR WEST EVEN STRUGGLING TO RISE ABOVE 0. IN FACT...LOOKING AT
THE 00Z ECMWF ENSEMBLE MEMBERS AT KSAW AND OTHER SITES IN THE
WESTERN/CENTRAL U.P....THERE MAY END UP BEING A 24-36 HOUR PERIOD OF
SUB ZERO TEMPERATURES LATE SUNDAY NIGHT THROUGH AT LEAST TUESDAY
MORNING. THE COMBINATION OF THE COLD TEMPERATURES AT NIGHT (SINGLE
DIGITS AND TEENS BELOW ZERO) AND WINDS IN THE 5-10MPH RANGE WILL
LEAD TO LOW WIND CHILL VALUES MONDAY/TUESDAY MORNINGS AND
POTENTIALLY EVENING WEDNESDAY MORNING. AS LONG AS THE WIND SPEEDS
STAY UP...WOULD EXPECT THE NEED FOR WIND CHILL ADVISORIES AT A
MINIMUM AND WILL CONTINUE TO ADDRESS IN THE HWO.
AS FOR LAKE EFFECT DURING THE FIRST PART OF NEXT WEEK...EXPECT WINDS
TO BACK TO THE WEST ON MONDAY AND WILL FOCUS THE LAKE EFFECT POPS
IN THOSE AREAS. WITH THE AMOUNT OF COLD AIR IN PLACE...VERY LITTLE
OF THE CLOUD LAYER WILL BE IN THE DGZ AND MOST WILL BE ABOVE
IT...WHICH LEADS TO MORE COLUMN/PLATE SNOWFLAKES AND WOULD EXPECT
ACCUMULATIONS TO BE LIMITED. WINDS WILL SHIFT MORE TO THE NORTHWEST
ON TUESDAY BEHIND THAT NEXT SHORTWAVE AND WILL TREND POPS TO THAT
FAVORED WIND DIRECTION. WITH THE AMOUNT OF COLD AIR...THERE
SHOULDN/T BE MUCH OF AN ISSUE FOR AT LEAST SOME LAKE EFFECT...SO
DID TREND POPS UP TO LIKELY-DEFINITE VALUES EVEN THOUGH AMOUNTS
SHOULD BE LIMITED. AS THE UPPER TROUGH SHIFTS EAST ON WEDNESDAY AND
THROUGH THE END OF THE WORK WEEK...THE UPPER GREAT LAKES REGION
SHOULD SEE A MODERATION IN THEIR TEMPERATURES TOWARDS MORE NORMAL
VALUES TOWARDS THE END OF NEXT WEEK. LOOKING AT THE 00Z ECMWF
ENSEMBLE MEAN FOR DAYS 9-15...IT SHOWS MORE OF A ZONAL FLOW ACROSS
THE CONUS...WHICH WOULD TRANSLATE TO MORE NORMAL OR EVEN SLIGHTLY
ABOVE NORMAL TEMPERATURES HEADING INTO THE MIDDLE OF JANUARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1209 AM EST THU JAN 1 2015
WINDS HAVE BECOME MORE WESTERLY OVER THE WESTERN U.P. WITH THE
PASSAGE OF A WEAK SHORTWAVE. WESTERLY FLOW HAS RESULTED IN ENHANCED
LES AT KCMX AT TIMES...WITH VSBYS OCCASIONALLY FALLING TO LIFR DUE
TO SNOW AND BLOWING SNOW WHILE CIGS LOWER TO IFR. AS WINDS VEER TO
NW DURING THE LATE MORNING HOURS...EXPECT KCMX CONDITIONS TO IMPROVE
WITH MVFR PREVAILING BY MIDDAY. KIWD TO SEE LES AND BLSN IN NW FLOW
WITH MAINLY MVFR CONDITIONS THERE...WITH BRIEF PERIODS OF IFR DUE TO
HEAVIER LES. KSAW TO SEE MVFR CONDITIONS AS NW DOWNSLOPE THERE NOT
FAVORABLE FOR LOWER CIGS/VSBYS.
&&
.MARINE...(FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 412 AM EST THU JAN 1 2015
A LOW OVER S HUDSON BAY WILL SHIFT INTO N QUEBEC FRIDAY MORNING. THE
TROUGH EXTENDING FROM THIS LOW ACROSS LAKE SUPERIOR WILL SLOWLY
WEAKEN. AS A RESULT...EXPECT THE GALES OF 35-40KTS TO SLOWLY
DIMINISH TOO. WHILE HEAVY FREEZING SPRAY HAS DIMINISHED THIS
MORNING...IT WILL PICK UP AGAIN OVER N LAKE SUPERIOR THIS
AFTERNOON-EVENING.
HIGH PRESSURE SINKING ACROSS MINNESOTA THIS EVENING WILL STRETCH
FROM THE GREAT LAKES THROUGH THE OHIO VALLEY ON FRIDAY...AND EXIT TO
SOUTHERN QUEBEC AND THE NEW ENGLAND STATES FRIDAY NIGHT. EXPECT A
LOW ACROSS THE DAKOTAS FRIDAY NIGHT TO CONSOLIDATE WITH AN
ADDITIONAL LOW ACROSS THE MISSISSIPPI VALLEY. THE NEW LOW WILL MOVE
NE AND DEEPEN ACROSS LOWER MICHIGAN AND LAKE HURON SATURDAY
NIGHT...AND EXIT S QUEBEC ON SUNDAY. THIS WILL BRING A TROUGH
SATURDAY NIGHT INTO SUNDAY FOR LAKE SUPERIOR. N-NW GALES OF 35 TO
NEAR 40KTS WILL AGAIN BE POSSIBLE SUNDAY INTO SUNDAY EVENING. BY
MONDAY...A RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER
MISSISSIPPI VALLEY. HEAVY FREEZING SPRAY WILL ALSO RETURN AS A COLD
RIDGE WILL SETTLE ACROSS THE N PLAINS AND UPPER MISSISSIPPI VALLEY
MONDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE SUPERIOR...
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
241>251-263>265.
HEAVY FREEZING SPRAY WARNING FROM 1 PM THIS AFTERNOON TO 3 AM
EST FRIDAY FOR LSZ263-264.
LAKE MICHIGAN...
NONE.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...RJT
MARINE...KF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1210 AM EST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH THURSDAY)
ISSUED AT 429 PM EST WED DEC 31 2014
WV IMAGERY AND RUC ANALYSIS INDICATED NW MID/UPPER LEVEL FLOW FROM
NW CANADA INTO THE GREAT LAKES BETWEEN A TROUGH OVER HUDSON BAY AND
A RIDGE FROM THE ERN PACIFIC INTO BC. A SHORTWAVE TROUGH WAS MOVING
THROUGH UPPER MI WITH ANOTHER WEAKER SHRTWV UPSTREAM OVER MANITOBA.
ANOTHER CLIPPER SHRTWV WAS FARTHER UPSTREAM OVER NW SASK. AT THE
SFC...STRONG WEST WINDS PREVAILED ACROSS THE REGION BETWEEN A 988 MB
LOW NEAR HUDSON BAY AND 1036 MB ARCTIC HIGH PRES INTO THE SRN
PLAINS. THE STRONGEST WINDS THIS MORNING INTO EARLY AFTERNOON ACROSS
LAKE SUPERIOR OCCURRED AS THE STRONGER PRES FALLS SLID THROUGH NRN
ONTARIO. WITH 850 MB TEMPS AROUND -19C AND CONVERGENT WRLY FLOW
DEVELOPING LES HAS INCREASED ACROSS THE KEWEENAW AS WINDS VEERED
FROM SW TO W.
TONIGHT...EXPECT THE STRONGEST LOW LEVEL CONV SUPPORTING LES TO
REMAIN OVER THE KEWEENAW. EVEN WITH A FAVORABLE POSITION OF THE DGZ
IN THE CLOUD LAYER...THE STRONGER WINDS WILL CREATE ENOUGH
COMPACTION/FRACTURING TO LIMIT SLR VALUES CLOSER TO 20/1. SO OVERALL
ACCUMULATIONS TONIGHT IN THE 2 TO 5 INCH RANGE ARE EXPECTED. WINDS
GUSTING INTO THE 30 TO 40 MPH RANGE WILL ALSO CONTINUE TO PRODUCE
CONSIDERABLE BLOWING AND DRIFTING SNOW IN OPEN AREAS WHERE OCNL
WHITEOUT CONDITIONS ARE POSSIBLE. WINDS ARE EXPECTED TO DIMINISH
OVERNIGHT REDUCING THE BLSN HAZARDS.
THU...THE NRN SASK SHRTWV TROUGH WILL BRUSH THE AREA WITH ENOUGH
700-500 MB QVECTOR CONV AND 800-600 MB FGEN TO SUPPORT AN AREA OF
LIGHT SNOW FROM NRN MN INTO NRN WI AND UPPER MI. WITH THE LACK OF
SIGNFICANT MOISTURE INFLOW/AVAILABILITY...SNOW AMOUNTS OF A HALF
INCH OR LESS ARE EXPECTED. HOWEVER...THE DEEPER MOISTURE WITH
INCREASING INVERSION HEIGHTS INTO THE AREA WILL SUPPORT GREATER LES
INTENSITY FOR THE W TO WNW FLOW LES SNOW BELTS. SINCE THE STRONGER
LOW LEVEL CONV IS EXPECTED TO SHIFT SOUTHWARD OVERALL SNOW AMOUNTS
SHOULD REMAIN IN THE 1 TO 3 INCH RANGE.
.LONG TERM...(THURSDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 316 PM EST WED DEC 31 2014
AN UPPER TROUGH OVER EASTERN CANADA LEAD TO COLD AIR AND LAKE
EFFECT SNOW OVER THE NORTHWEST WIND SNOW BELTS TO START THE PERIOD.
THIS LIGHT TO OCCASIONALLY MODERATE LAKE EFFECT SNOW WILL CONTINUE
IN THOSE NORTHWEST WIND BELTS ON THURSDAY NIGHT...BUT AS THE LOW
LEVEL WINDS BACK LATE THURSDAY NIGHT INTO FRIDAY MORNING...WILL
FOCUS THE POPS/SNOW TO THE WEST-NORTHWEST AREAS ON FRIDAY (AND
WESTERLY AREAS LATE FRIDAY AFTERNOON). WHILE LAKE INDUCED
EQUILIBRIUM LEVELS WILL BE AROUND 8KFT...THERE ARE SOME CONCERNS IN
THE AMOUNT OF MOISTURE AVAILABLE AS SUBSIDENCE AND DRIER AIR ARRIVE
THURSDAY NIGHT FROM A HIGH MOVING SOUTHEAST INTO MINNESOTA.
THUS...WILL STICK WITH A DUSTING TO 3-4IN EVERY 12HRS THROUGH
FRIDAY...WITH THE HIGHEST AMOUNTS OVER THE EAST WITH THE LONGER
FETCH AND SOME INDICATIONS OF A LINGERING TROUGH AIDING
CONVERGENCE TOWARDS WHITEFISH POINT. THE HIGH WILL SHIFT SOUTHEAST
OF THE AREA ON FRIDAY EVENING...BACKING WINDS TO THE SOUTHWEST AND
ONLY LEAVING LAKE EFFECT SNOW OVER THE KEWEENAW FOR FRIDAY NIGHT.
THE FOCUS THEN TURNS TO THE INTERACTION AND PHASING OF THE SPLIT
FLOW FOR THE START OF THE WEEKEND. MODELS SEEM TO COMING INTO
BETTER AGREEMENT ON THE OVERALL IDEA FOR THE WEEKEND...ALTHOUGH
THERE ARE STILL SMALLER DIFFERENCES THAT COULD HAVE AN IMPACT ON
THE AMOUNT OF SNOW SEEN OVER PARTS OF THE U.P. THERE ARE TWO
FEATURES AT PLAY FOR THIS WEEKEND...THE FIRST IS THE REMNANTS OF
THE UPPER LOW PRODUCING SNOW OVER THE SOUTHWEST CONUS TODAY AND THE
SECOND FEATURE IS A SHORTWAVE CURRENTLY OVER THE ALEUTIANS ISLANDS
AND DROPPING SOUTHEAST INTO THE NORTHERN ROCKIES ON FRIDAY NIGHT.
THIS WILL LEAD TO A LOW DEVELOPING IN THE LEE OF THE NORTHERN
ROCKIES AND THEN MOVING EAST INTO THE DAKOTAS AND WESTERN MINNESOTA
BY SATURDAY MORNING. EXPECT SNOW TO SPREAD EAST AHEAD OF THIS LOW
AND INTO THE NORTHWEST HALF OF THE CWA...ASSOCIATED WITH STRONG MID
LEVEL WARM AIR ADVECTION. WHILE THE HEAVIEST SNOW APPEARS TO OCCUR
OVER LAKE SUPERIOR...WILL SHOW SOME LIKELY POPS OVER AND AROUND THE
KEWEENAW PENINSULA FOR SATURDAY. AS THAT IS OCCURRING...THE
NORTHERN SHORTWAVE WILL CONTINUE TO DIVE SOUTHEAST AND PHASE WITH
THE SOUTHERN UPPER LOW AND LEAD TO BOTH EJECTING NORTHEAST THROUGH
THE LOWER GREAT LAKES REGION SATURDAY NIGHT INTO SUNDAY. AS
EXPECTED IN THESE PHASING EVENTS...EACH MODEL RUN GIVES A SLIGHTLY
DIFFERENT IDEA ON THE EVOLUTION OF THE PHASED FEATURES AND IN TURN
THE SURFACE FEATURES. OVERALL...THE GENERAL IDEA IS FOR A
STRENGTHENING LOW TO LIFT NORTHEAST THROUGH SOUTHEAST LOWER
MICHIGAN ON SATURDAY NIGHT AND THEN INTO QUEBEC ON SUNDAY. WITH
THAT TRACK...WOULD EXPECT MUCH OF THE SYNOPTIC
FORCING/PRECIPITATION ASSOCIATED WITH THOSE FEATURES TO MISS THE
U.P....BUT WOULD STILL EXPECT AT LEAST SOME LAKE ENHANCEMENT AS THE
WINDS TURN TO THE NORTHWEST BEHIND THE ELONGATED SURFACE TROUGH
STRETCHING NORTH OVER EASTERN LAKE SUPERIOR LATE SATURDAY NIGHT.
INITIALLY...WOULDN/T EXPECT THE LAKE ENHANCEMENT TO AMOUNT TO TOO
HIGH OF SNOWFALL AMOUNTS ON SATURDAY NIGHT...BUT AS MUCH COLDER AIR
MOVES INTO THE AREA (850MB TEMPS FALLING TO -25C BY 00Z MONDAY) AND
THE DEEPER MOISTURE IS STILL PRESENT FROM THE DEPARTING
SYSTEM...WOULD EXPECT THE LAKE ENHANCEMENT/EFFECT SNOW TO TAKE OFF
ON SUNDAY IN THE NORTHWEST WIND SNOW BELTS. WILL TREND POPS UP TO
DEFINITE VALUES DURING THIS PERIOD AND CONTINUE TO MENTION
MODERATE/HEAVY SNOW WORDING IN THE HWO.
BEHIND THE LOW...EXPECT THE FIRST PART OF THE WORK WEEK TO BE VERY
COLD WITH CONTINUED LAKE EFFECT SNOW. THE CANADIAN UPPER TROUGH
WILL SAG SOUTH INTO THE GREAT LAKES REGION AND KEEP THE COLD AIR IN
PLACE (850MB TEMPS IN THE LOW 20C BELOW ZERO)...WITH ANOTHER
SHORTWAVE MOVING THROUGH ON MONDAY NIGHT POTENTIALLY PULLING 850MB
TEMPERATURES CLOSE TO -30C FOR TUESDAY. THAT WILL LEAD TO VERY COLD
HIGH TEMPERATURES FOR MONDAY/TUESDAY...WITH SOME LOCATIONS OVER THE
INTERIOR WEST EVEN STRUGGLING TO RISE ABOVE 0. IN FACT...LOOKING AT
THE 00Z ECMWF ENSEMBLE MEMBERS AT KSAW AND OTHER SITES IN THE
WESTERN/CENTRAL U.P....THERE MAY END UP BEING A 24-36 HOUR PERIOD OF
SUB ZERO TEMPERATURES LATE SUNDAY NIGHT THROUGH AT LEAST TUESDAY
MORNING. THE COMBINATION OF THE COLD TEMPERATURES AT NIGHT (SINGLE
DIGITS AND TEENS BELOW ZERO) AND WINDS IN THE 5-10MPH RANGE WILL
LEAD TO LOW WIND CHILL VALUES MONDAY/TUESDAY MORNINGS AND
POTENTIALLY EVENING WEDNESDAY MORNING. AS LONG AS THE WIND SPEEDS
STAY UP...WOULD EXPECT THE NEED FOR WIND CHILL ADVISORIES AT A
MINIMUM AND WILL CONTINUE TO ADDRESS IN THE HWO.
AS FOR LAKE EFFECT DURING THE FIRST PART OF NEXT WEEK...EXPECT WINDS
TO BACK TO THE WEST ON MONDAY AND WILL FOCUS THE LAKE EFFECT POPS
IN THOSE AREAS. WITH THE AMOUNT OF COLD AIR IN PLACE...VERY LITTLE
OF THE CLOUD LAYER WILL BE IN THE DGZ AND MOST WILL BE ABOVE
IT...WHICH LEADS TO MORE COLUMN/PLATE SNOWFLAKES AND WOULD EXPECT
ACCUMULATIONS TO BE LIMITED. WINDS WILL SHIFT MORE TO THE NORTHWEST
ON TUESDAY BEHIND THAT NEXT SHORTWAVE AND WILL TREND POPS TO THAT
FAVORED WIND DIRECTION. WITH THE AMOUNT OF COLD AIR...THERE
SHOULDN/T BE MUCH OF AN ISSUE FOR AT LEAST SOME LAKE EFFECT...SO
DID TREND POPS UP TO LIKELY-DEFINITE VALUES EVEN THOUGH AMOUNTS
SHOULD BE LIMITED. AS THE UPPER TROUGH SHIFTS EAST ON WEDNESDAY AND
THROUGH THE END OF THE WORK WEEK...THE UPPER GREAT LAKES REGION
SHOULD SEE A MODERATION IN THEIR TEMPERATURES TOWARDS MORE NORMAL
VALUES TOWARDS THE END OF NEXT WEEK. LOOKING AT THE 00Z ECMWF
ENSEMBLE MEAN FOR DAYS 9-15...IT SHOWS MORE OF A ZONAL FLOW ACROSS
THE CONUS...WHICH WOULD TRANSLATE TO MORE NORMAL OR EVEN SLIGHTLY
ABOVE NORMAL TEMPERATURES HEADING INTO THE MIDDLE OF JANUARY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z THURSDAY NIGHT)
ISSUED AT 1209 AM EST THU JAN 1 2015
WINDS HAVE BECOME MORE WESTERLY OVER THE WESTERN U.P. WITH THE
PASSAGE OF A WEAK SHORTWAVE. WESTERLY FLOW HAS RESULTED IN ENHANCED
LES AT KCMX AT TIMES...WITH VSBYS OCCASIONALLY FALLING TO LIFR DUE
TO SNOW AND BLOWING SNOW WHILE CIGS LOWER TO IFR. AS WINDS VEER TO
NW DURING THE LATE MORNING HOURS...EXPECT KCMX CONDITIONS TO IMPROVE
WITH MVFR PREVAILING BY MIDDAY. KIWD TO SEE LES AND BLSN IN NW FLOW
WITH MAINLY MVFR CONDITIONS THERE...WITH BRIEF PERIODS OF IFR DUE TO
HEAVIER LES. KSAW TO SEE MVFR CONDITIONS AS NW DOWNSLOPE THERE NOT
FAVORABLE FOR LOWER CIGS/VSBYS.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 429 PM EST WED DEC 31 2014
LAKE SUPERIOR WILL BE STUCK BETWEEN VERY STRONG HIGH PRESSURE ACROSS
THE S PLAINS AND A DEEP HUDSON BAY LOW TODAY. GALES OF 35-45KTS WILL
CONTINUE BEFORE SLOWLY DIMINISHING TO 35KTS LATE TONIGHT INTO
THURSDAY MORNING OUT OF THE W-NW. GIVEN PLENTY OF COLD AIR...AND
STRONG WINDS...HEAVY FREEZING SPRAY WILL ALSO BE A CONCERN INTO
THURSDAY.
LOOK FOR THE TROUGH OVER LAKE SUPERIOR TO DEEPEN TONIGHT THROUGH
THURSDAY. THE HUDSON BAY LOW WILL SHIFT AND WEAKEN ACROSS N QUEBEC
THURSDAY NIGHT...ALLOWING THE TROUGH ACROSS LAKE SUPERIOR TO WEAKEN
AS WELL. HIGH PRESSURE SINKING ACROSS MANITOBA AND MINNESOTA
THURSDAY NIGHT WILL BUILD RIDGE ACROSS LAKE SUPERIOR ON FRIDAY AS IT
PROGRESSES ACROSS THE REMAINDER OF THE GREAT LAKES. A WEAK TROUGH
WILL LIKELY LINGER ACROSS MAINLY E LAKE SUPERIOR DURING THIS TIME.
EXPECT A LOW NEAR MONTANA ON FRIDAY TO TRACK ACROSS THE N AND
CENTRAL PLAINS SATURDAY MORNING...AND THE MID MISSISSIPPI VALLEY
SATURDAY AFTERNOON...BEFORE DEEPENING NORTHEASTWARD ACROSS THE LOWER
GREAT LAKES AND QUEBEC LATE SATURDAY NIGHT INTO SUNDAY. THIS WILL
BRING A TROUGH THROUGH THE AREA SATURDAY NIGHT INTO SUNDAY...ALONG
WITH THE POTENTIAL FOR N-NW GALES. HEAVY FREEZING SPRAY WILL
ALSO MAKE A RETURN ACROSS MUCH OF LAKE SUPERIOR.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
LAKE EFFECT SNOW ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR
MIZ001-003.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING UNTIL 4 AM EST /3 AM CST/ EARLY
THIS MORNING FOR LSZ162-240>245-248>251-263>267.
GALE WARNING UNTIL 10 AM EST THIS MORNING FOR LSZ266-267.
GALE WARNING UNTIL 7 AM EST /6 AM CST/ THIS MORNING FOR LSZ162-
241>251-263>265.
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST EARLY THIS MORNING
FOR LSZ246-247.
LAKE MICHIGAN...
HEAVY FREEZING SPRAY WARNING UNTIL 1 AM EST EARLY THIS MORNING
FOR LMZ221-248-250.
GALE WARNING UNTIL 1 AM EST EARLY THIS MORNING FOR LMZ221-250.
&&
$$
SHORT TERM...JLB
LONG TERM...SRF
AVIATION...RJT
MARINE...JLB
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
931 AM CST THU JAN 1 2015
.UPDATE...
SUBSTANTIAL ADJUSTMENTS NEEDED TO FORECAST TODAY...PRIMARILY TO
INCREASE POPS ESPECIALLY OVER S/SW SECTIONS...AND TO LOWER TEMPS A
BIT.
&&
.SHORT TERM...
MORNING RADAR AND ANALYSES SHOW EXPANDING AREA OF PRECIPITATION
ACROSS MUCH OF LA/E TX/S AR/SW MS. THIS IS IN AREA OF INCREASING
MOISTURE ADVECTION/ISENTROPIC ASCENT ABOVE REMNANT WEAKENING SFC HIGH
PRESSURE ACROSS REGION. RADAR TRENDS AND LATEST HRRR/RAP MODELS
SUGGEST THAT EARLIER GLOBAL MODELS WERE A BIT TOO FAR NORTH IN
DEPICTION OF BEST RAINFALL POTENTIAL FOR TODAY...WITH BETTER MOISTURE
ADVECTION LIKELY TO FOCUS BETTER QPF FARTHER TO THE S CLOSER TO THE
I-20 CORRIDOR. BLEND OF LAST FEW HRRR RUNS SUGGEST AN AXIS OF 0.5 TO
1.5" OF QPF THROUGH EARLY THIS EVENING FROM THE LOWER ARKLAMISS DELTA
BACK WSW INTO EC TX...WITH AMOUNTS OF AT LEAST .1" OVER MOST OF OUR
SERVICE AREA. HENCE HAVE ADJUSTED POPS TO MAINTAIN HIGH POPS OVER
DELTA BUT EXPAND CATEGORICAL POPS TO ENCOMPASS MOST OF THE WESTERN
2/3 OF OUR AREA. TAPERED POPS TO THE E WHERE BETTER MOISTURE
ADVECTION WILL BE SLOWER TO ARRIVE AND HENCE BETTER CHANCES FOR RAIN.
HAVE HAD A COUPLE OF REPORTS OF SLEET IN WESTERN AREAS THIS
MORNING...AND COLD...DRY SUBCLOUD LAYER DEPICTED IN SOUNDINGS THIS
MORNING SUGGEST THIS REMAINS A POSSIBILITY NEXT FEW HOURS ESPECIALLY
NORTHERN HALF OF AREA. HAVE KEPT THIS IN GRIDS...BUT AS MENTIONED IN
PREVIOUS AFD SHOULD NOT BE ANY IMPACT WITH TEMPS ABOVE FREEZING.
LIGHTNING DATA HAS SHOWN SPORADIC STRIKES WITH ACTIVITY SHIFTING
ACROSS E TX THIS MORNING...AND MODELS SHOW A COUPLE OF HUNDRED OF
JOULES OF ELEVATED CAPE WORKING INTO SW SECTIONS OF OUR AREA THIS
AFTERNOON. THIS IN COMBO WITH HRRR HAVING SOME CONVECTIVE LOOKING
ELEMENTS IN ITS REFLECTIVITY FORECASTS HAVE RESULTED IN AN ADDITION
OF SLGT CHC TSRA FOR SW AREAS THIS AFTERNOON WHICH ALSO AGREES WITH
LATEST SPC DAY 1 OUTLOOK.
GIVEN ARRIVAL OF CLOUDS/RAIN AND CONTINUED STAGNANT REMNANT
COLD...DRY SURFACE HIGH OVER AREA...THINK TEMPS WILL REALLY
STRUGGLE MOST AREAS TODAY. HENCE HAVE KNOCKED A COUPLE OF DEGS OFF
MAXES AND WENT WITH HRRR HOURLY TEMPS. A BIT OF MORNING SUN IN FAR
E/SE SECTIONS COULD ALLOW TEMPS THERE TO REACH FORECAST MAXES AND
HRRR SUPPORTS THIS AS WELL...SO PRETTY MUCH LEFT MAXES IN THOSE AREAS
ALONE. /AEG/
&&
.AVIATION...
CIGS CONTINUE TO BE MAINLY VFR EVEN WITH LIGHT PRECIPITATION
SPREADING EASTWARD ACROSS THE MS RIVER...INCLUDING SOME
INSIGNIFICANT AMOUNTS OF LIGHT SLEET AT THE ONSET. BUT CONDITIONS
QUICKLY WORSEN JUST WEST OF THE FORECAST AREA WITH WIDESPREAD
MVFR/IFR CIGS AND VSBYS ASSOCIATED WITH RA/TSRA OVER WRN LA. EXPECT
THIS HEAVIER RAINFALL TO CONTINUE TO DEVELOP EAST AND AFFECT THE
GLH/GWO/JAN/HKS AREA INITIALLY THIS AFTERNOON...THEN ALL TAF SITES
AS WE GO THROUGH TONIGHT. SOME ISOLATED TSRA WILL BE POSSIBLE
PARTICULARLY AT GLH/JAN/HKS/HBG. FRIDAY WILL BE A POOR AVIATION
WEATHER DAY WITH WIDESPREAD RA/TSRA PRODUCING IFR CONDITIONS OVER
THE ENTIRE AREA. /EC/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 46 43 52 52 / 91 86 85 67
MERIDIAN 54 44 52 52 / 63 75 86 66
VICKSBURG 44 41 50 50 / 96 91 87 75
HATTIESBURG 56 48 60 60 / 58 64 71 50
NATCHEZ 44 43 56 55 / 92 86 75 71
GREENVILLE 45 38 45 44 / 95 95 93 82
GREENWOOD 47 39 47 47 / 90 91 91 74
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
AEG/EC
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
504 AM CST THU JAN 1 2015
.DISCUSSION...
HAPPY NEW YEAR FROM ALL OF US AT NWS JACKSON!
SHORT TERM (TODAY THROUGH FRIDAY NIGHT)...
WHILE COOL/RELATIVELY DRY NORTHERLY/EASTERLY FLOW WILL CONTINUE AT
THE SURFACE...BIG CHANGES ARE AFOOT ABOUT 2000 FEET UP. FLOW IN THE
LOWER LEVELS OF THE ATMOSPHERE WILL SHIFT AROUND TO THE SOUTHWEST...
WITH STRONG ISENTROPIC UPGLIDE COMMENCING OVER THE REGION BRINGING
INCREASING PRECIP CHANCES BY THIS AFTERNOON. LOOKING EVEN HIGHER IN
THE ATMOSPHERE...AN UPPER LOW WAS LOCATED NEAR THE FOUR CORNERS
REGION WITH A SPLIT UPPER JET OVER THE WEST PHASING TOGETHER OVER
THE MIDWEST/MID ATLANTIC. MID AND HIGH CLOUDS HAVE ALREADY BEEN ON
THE INCREASE ACROSS MUCH OF THE REGION OVERNIGHT...WHICH HAS LIMITED
RADIATIONAL COOLING IN MANY AREAS. AS MORE SUBSTANTIAL ATMOSPHERIC
MOISTENING OCCURS THROUGH THE DAY...THE CLOUD DECK WILL GRADUALLY
LOWER AND LIGHT PRECIP WILL BEGIN TO REACH THE SURFACE.
REGIONAL RADAR SHOWED LIGHT PRECIP REACHING THE ARKLATEX INTO NW
LOUISIANA. LATEST HRRR RUNS SUGGEST SOME OF THIS ACTIVITY WILL MOVE
INTO OUR NE LOUISIANA PARISHES SHORTLY AFTER DAYBREAK... SLOWLY
SPREADING EASTWARD THROUGH THE MORNING. DUE TO SUBSTANTIALLY DRY AIR
BELOW AROUND 800 MB...IT MAY TAKE A WHILE FOR PRECIP TO REACH THE
GROUND...SO WE MAY SEE SEVERAL ECHOES ON RADAR WITH ONLY SPRINKLES
INITIALLY. THIS DRY AIR MAY ALSO LEAD TO SOME LIGHT SLEET AT THE
ONSET OF PRECIPITATION OVER THE DELTA AS WETBULBING OCCURS IN THE DRY
LAYER. BUFR SOUNDINGS SUGGEST THIS WILL BE POSSIBLE UNTIL AROUND OR
SHORTLY AFTER NOON. MAINTAINED A MENTION OF SLIGHT CHANCE OF SLEET IN
THE FORECAST...BUT TO BE CLEAR...NO MEASURABLE SLEET AND NO IMPACTS
ARE EXPECTED AS SURFACE TEMPS WILL BE ABOVE FREEZING DURING THIS TIME
PERIOD AND PRECIP WILL BE RATHER LIGHT.
MORE SUBSTANTIAL RAIN CHANCES WILL COME OVER THE NORTHWEST HALF OF
THE CWA THIS AFTERNOON INTO TONIGHT ONCE LOW LEVEL DRY AIR IS NO
LONGER AN ISSUE. THE CLOSED UPPER LOW WILL BECOME EMBEDDED IN UPPER
LEVEL FLOW AS A TROUGH MOVING INTO THE SOUTHERN PLAINS ON FRIDAY.
THIS WILL BRING MORE FAVORABLE UPPER DIVERGENCE OVER THE AREA...
ESPECIALLY FARTHER NORTH IN THE CWA CLOSER TO THE UPPER JET
STREAK...WITH CONTINUED ISENTROPIC ASCENT IN THE LOWER LEVELS. THUS
LIKELY TO CATEGORICAL POPS WILL BE MAINTAINED ACROSS MOST OF THE CWA
THROUGH FRIDAY NIGHT. THOUGH THE ATMOSPHERE WILL REMAIN STABLE AT THE
SURFACE THROUGH MUCH OF THIS TIME...THERE WILL BE ELEVATED
INSTABILITY AND CHANCE/SLIGHT CHANCE THUNDERSTORMS WERE MAINTAINED IN
THE FORECAST.
THE EASTWARD ADVANCE OF THE UPPER TROUGH WILL ALSO PROMPT SURFACE
CYCLOGENESIS ALONG THE NW GULF COAST. THIS LOW WILL TRACK NORTHWARD
FRIDAY NIGHT...FINALLY BRINGING RETURN FLOW AT THE SURFACE OVERNIGHT.
SOME SURFACE BASED CONVECTION WILL BE POSSIBLE ACROSS THE SOUTH PART
OF THE AREA OVERNIGHT AS DEWPOINTS RISE INTO THE MID 60S WITH SBCAPES
POTENTIALLY RISING INTO THE 500-1000 J/KG RANGE. TEMPERATURES THROUGH
THE SHORT TERM WILL PRIMARILY BE DRIVEN BY THE PRESENCE OF CLOUDS AND
PRECIP...AND WAA ON FRIDAY NIGHT. TRENDED CLOSE TO RAW TEMP GUIDANCE
THROUGHOUT THE PERIOD. /DL/
LONG TERM (SATURDAY THROUGH THURSDAY)L...ACTIVE WEATHER WILL CONTINUE
INTO THE EXTENDED...WHERE THE PRIMARY FOCUS WILL BE ON HEAVY RAIN AND
STORM POTENTIAL.
ON SATURDAY A MID TO UPPER LEVEL CLOSED LOW WILL BE MOVING THROUGH
THE PLAINS AND WILL EJECT AS A NEGATIVE TILTED SHORTWAVE TOWARD THE
THE OHIO VALLEY. WE WILL BE UNDER THE RIGHT REAR QUAD OF AN MID TO
UPPER LEVEL JET. ALSO LOWLEVEL JET WINDS(850-925 MB) WILL BE AROUND
35 TO 55 KNOTS...FROM THE SOUTH. THIS WILL SPELL GUSTY SOUTH WINDS
ACROSS THE REGION WITH GUSTS 25-28 KNOTS. MEANWHILE LARGE SCALE
MOISTURE TRANSPORT AND ASCENT WILL BE IN PROGRESS AS THE WARM SECTOR
SURGES 60S DEWPOINTS INTO MOST OF THE REGION. THE QUESTION IS HOW FAR
NORTH WILL WARM MARINE LAYER (MID TO UPPER 60S DEWPOINTS) TRAVEL. A
COLD FRONT WILL MOVE ACROSS THE REGION DURING THE DAY WITH A SURFACE
LOW MOVING NORTHEAST AND DEEPENING. CHECKING 00Z AND 12Z MODEL RUNS
WHICH WERE SIMILAR WITH THE TRACK OF THE SURFACE LOW GENERALLY WEST
OF THE MS RIVER...THUS BRINGING BETTER LOW LEVEL INSTABILITY ACROSS
MOST THE REGION. MODEL SOUNDINGS SHOW GOOD SHEAR ALONG WITH CURVED
HODOGRAPHS FOR SOME SEVERE POTENTIAL. THE GFS TRIES TO BRING IN 65
PLUS DEWPOINTS NEAR THE I-20 CORRIDOR WITH NEAR 70 DEWPOINTS NEAR OUR
SOUTHEAST BORDER. THIS WILL BRING SOME CAPES IN EXCESS OF 1500 J/KG.
THE SHEAR VECTORS WILL BE GENERALLY PARALLEL TO THE FRONT FOR SOME
POSSIBLE QLCS COMPLEXES ALONG WITH HELICITY > 300. HEIGHTS ACROSS THE
SOUTHEAST THOUGH ARE A LITTLE HIGH FOR THIS TIME OF THE YEAR. SPC
SREF...CIPS AND NAM MODELS POINT THE GREATEST SEVERE RISK ALONG THE
NATCHEZ TRACE CORRIDOR...WHERE THE HEIGHTS ARE A LITTLE MORE
CONDUCIVE. IF THIS TREND CONTINUES MAY CONSIDER PUTTING THAT AREA IN
AN ELEVATED RISK IN FUTURE MODEL RUNS. SO WILL KEEP THE LIMITED RISK
FOR NOW. THE COLD FRONT WILL EXIT THE REGION DURING THE EVENING THUS
ENDING THE SEVERE RISK.
LOOKING AT THE HEAVY RAIN RISK. PWATS WILL INCREASE TO AROUND 1.7
INCHES WHICH IS THE HIGHER AVERAGE PERCENTILE FOR THIS TIME OF
YEAR...WHICH SPELLS EFFICIENT RAINS. MODELS AND HPC ARE GENERALLY
GOING FOR 1-2 INCHES WITH LOCALLY INCH AMOUNTS POSSIBLE ALONG AND
AHEAD OF THE COLD FRONT. THIS WILL ADD TO OUR RECENT RAINS FOR
SATURATED SOIL CONDITIONS. SO WILL KEEP THE LIMITED RISK FOR
FLOODING FOR FRIDAY INTO SATURDAY. UNLESS THE MODELS SIGNAL
HIGHER RAINFALL AMOUNTS IN FUTURE MODEL RUNS...NO FLOOD WATCH WILL
BE CONSIDERED AT THIS TIME.
THE RAINS WILL EXIT THE REGION ON SUNDAY MORNING. HIGH PRESSURE WILL
SETTLE ACROSS THE REGION ON MONDAY. SO DRY AND COOL CONDITIONS WILL
PREVAIL FOR SUNDAY THROUGH WEDNESDAY. ANOTHER SURGE OF COOL AIR WILL
PUSH INTO THE REGION FOR TUESDAY INTO WEDNESDAY. WITH THIS AIRMASS
IT LOOKS LIKE THE BEST PART OF THIS AIRMASS WILL MISS THE REGION
TO THE NORTH. ON THURSDAY SHORTWAVE RIDGING WILL BUILD IN FROM THE
WEST AS LOW LEVEL RETURN FLOW COMES IN FOR SOME SHOWERS IN THE
SOUTHWEST BY EARLY FRIDAY./17/
&&
.AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH AT LEAST EARLY
AFTERNOON AT MOST TERMINALS...BUT THE MID CLOUD DECK WILL GRADUALLY
LOWER THROUGH THE DAY...LIKELY REACHING MVFR CATEGORY TONIGHT IN ALL
AREAS EXCEPT AROUND MEI AND HBG. LIGHT RAIN WILL SPREAD EASTWARD INTO
THE REGION THIS MORNING...BECOMING MODERATE LATER ON TONIGHT. THIS
MAY BRING VISIBILITY REDUCTIONS TO MVFR ESPECIALLY AT NORTHWEST
TERMINALS WHERE MORE SUBSTANTIAL RAINFALL IS EXPECTED THROUGH THE TAF
PERIOD. CEILING AND OCCASIONAL VISIBILITY REDUCTIONS WILL LIKELY
PERSIST THROUGH THE WEEKEND. THERE IS A SMALL CHANCE OF LIGHT SLEET
AT GWO AND GLH THIS MORNING...BUT NO ISSUES ARE EXPECTED TO RESULT
FROM THIS. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 47 43 52 52 / 34 86 85 67
MERIDIAN 52 44 52 52 / 17 75 86 66
VICKSBURG 43 41 50 50 / 61 91 87 75
HATTIESBURG 57 48 60 60 / 21 64 71 50
NATCHEZ 45 43 56 55 / 42 86 75 71
GREENVILLE 40 38 45 44 / 93 95 93 82
GREENWOOD 44 39 47 47 / 91 91 91 74
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/17
AREA FORECAST DISCUSSION
NWS JACKSON MS
418 AM CST THU JAN 1 2015
.DISCUSSION...
HAPPY NEW YEAR FROM ALL OF US AT NWS JACKSON!
SHORT TERM (TODAY THROUGH FRIDAY NIGHT)...
WHILE COOL/RELATIVELY DRY NORTHERLY/EASTERLY FLOW WILL CONTINUE AT
THE SURFACE...BIG CHANGES ARE AFOOT ABOUT 2000 FEET UP. FLOW IN THE
LOWER LEVELS OF THE ATMOSPHERE WILL SHIFT AROUND TO THE SOUTHWEST...
WITH STRONG ISENTROPIC UPGLIDE COMMENCING OVER THE REGION BRINGING
INCREASING PRECIP CHANCES BY THIS AFTERNOON. LOOKING EVEN HIGHER IN
THE ATMOSPHERE...AN UPPER LOW WAS LOCATED NEAR THE FOUR CORNERS
REGION WITH A SPLIT UPPER JET OVER THE WEST PHASING TOGETHER OVER
THE MIDWEST/MID ATLANTIC. MID AND HIGH CLOUDS HAVE ALREADY BEEN ON
THE INCREASE ACROSS MUCH OF THE REGION OVERNIGHT...WHICH HAS LIMITED
RADIATIONAL COOLING IN MANY AREAS. AS MORE SUBSTANTIAL ATMOSPHERIC
MOISTENING OCCURS THROUGH THE DAY...THE CLOUD DECK WILL GRADUALLY
LOWER AND LIGHT PRECIP WILL BEGIN TO REACH THE SURFACE.
REGIONAL RADAR SHOWED LIGHT PRECIP REACHING THE ARKLATEX INTO NW
LOUISIANA. LATEST HRRR RUNS SUGGEST SOME OF THIS ACTIVITY WILL MOVE
INTO OUR NE LOUISIANA PARISHES SHORTLY AFTER DAYBREAK... SLOWLY
SPREADING EASTWARD THROUGH THE MORNING. DUE TO SUBSTANTIALLY DRY AIR
BELOW AROUND 800 MB...IT MAY TAKE A WHILE FOR PRECIP TO REACH THE
GROUND...SO WE MAY SEE SEVERAL ECHOES ON RADAR WITH ONLY SPRINKLES
INITIALLY. THIS DRY AIR MAY ALSO LEAD TO SOME LIGHT SLEET AT THE
ONSET OF PRECIPITATION OVER THE DELTA AS WETBULBING OCCURS IN THE DRY
LAYER. BUFR SOUNDINGS SUGGEST THIS WILL BE POSSIBLE UNTIL AROUND OR
SHORTLY AFTER NOON. MAINTAINED A MENTION OF SLIGHT CHANCE OF SLEET IN
THE FORECAST...BUT TO BE CLEAR...NO MEASURABLE SLEET AND NO IMPACTS
ARE EXPECTED AS SURFACE TEMPS WILL BE ABOVE FREEZING DURING THIS TIME
PERIOD AND PRECIP WILL BE RATHER LIGHT.
MORE SUBSTANTIAL RAIN CHANCES WILL COME OVER THE NORTHWEST HALF OF
THE CWA THIS AFTERNOON INTO TONIGHT ONCE LOW LEVEL DRY AIR IS NO
LONGER AN ISSUE. THE CLOSED UPPER LOW WILL BECOME EMBEDDED IN UPPER
LEVEL FLOW AS A TROUGH MOVING INTO THE SOUTHERN PLAINS ON FRIDAY.
THIS WILL BRING MORE FAVORABLE UPPER DIVERGENCE OVER THE AREA...
ESPECIALLY FARTHER NORTH IN THE CWA CLOSER TO THE UPPER JET
STREAK...WITH CONTINUED ISENTROPIC ASCENT IN THE LOWER LEVELS. THUS
LIKELY TO CATEGORICAL POPS WILL BE MAINTAINED ACROSS MOST OF THE CWA
THROUGH FRIDAY NIGHT. THOUGH THE ATMOSPHERE WILL REMAIN STABLE AT THE
SURFACE THROUGH MUCH OF THIS TIME...THERE WILL BE ELEVATED
INSTABILITY AND CHANCE/SLIGHT CHANCE THUNDERSTORMS WERE MAINTAINED IN
THE FORECAST.
THE EASTWARD ADVANCE OF THE UPPER TROUGH WILL ALSO PROMPT SURFACE
CYCLOGENESIS ALONG THE NW GULF COAST. THIS LOW WILL TRACK NORTHWARD
FRIDAY NIGHT...FINALLY BRINGING RETURN FLOW AT THE SURFACE OVERNIGHT.
SOME SURFACE BASED CONVECTION WILL BE POSSIBLE ACROSS THE SOUTH PART
OF THE AREA OVERNIGHT AS DEWPOINTS RISE INTO THE MID 60S WITH SBCAPES
POTENTIALLY RISING INTO THE 500-1000 J/KG RANGE. TEMPERATURES THROUGH
THE SHORT TERM WILL PRIMARILY BE DRIVEN BY THE PRESENCE OF CLOUDS AND
PRECIP...AND WAA ON FRIDAY NIGHT. TRENDED CLOSE TO RAW TEMP GUIDANCE
THROUGHOUT THE PERIOD. /DL/
LONG TERM (SATURDAY THROUGH THURSDAY)L...ACTIVE WEATHER WILL CONTINUE
INTO THE EXTENDED...WHERE THE PRIMARY FOCUS WILL BE ON HEAVY RAIN AND
STORM POTENTIAL.
ON SATURDAY A MID TO UPPER LEVEL CLOSED LOW WILL BE MOVING THROUGH
THE PLAINS AND WILL EJECT AS A NEGATIVE TILTED SHORTWAVE TOWARD THE
THE OHIO VALLEY. WE WILL BE UNDER THE RIGHT REAR QUAD OF AN MID TO
UPPER LEVEL JET. ALSO LOWLEVEL JET WINDS(850-925 MB) WILL BE AROUND
35 TO 55 KNOTS...FROM THE SOUTH. THIS WILL SPELL GUSTY SOUTH WINDS
ACROSS THE REGION WITH GUSTS 25-28 KNOTS. MEANWHILE LARGE SCALE
MOISTURE TRANSPORT AND ASCENT WILL BE IN PROGRESS AS THE WARM SECTOR
SURGES 60S DEWPOINTS INTO MOST OF THE REGION. THE QUESTION IS HOW FAR
NORTH WILL WARM MARINE LAYER (MID TO UPPER 60S DEWPOINTS) TRAVEL. A
COLD FRONT WILL MOVE ACROSS THE REGION DURING THE DAY WITH A SURFACE
LOW MOVING NORTHEAST AND DEEPENING. CHECKING 00Z AND 12Z MODEL RUNS
WHICH WERE SIMILAR WITH THE TRACK OF THE SURFACE LOW GENERALLY WEST
OF THE MS RIVER...THUS BRINGING BETTER LOW LEVEL INSTABILITY ACROSS
MOST THE REGION. MODEL SOUNDINGS SHOW GOOD SHEAR ALONG WITH CURVED
HODOGRAPHS FOR SOME SEVERE POTENTIAL. THE GFS TRIES TO BRING IN 65
PLUS DEWPOINTS NEAR THE I-20 CORRIDOR WITH NEAR 70 DEWPOINTS NEAR OUR
SOUTHEAST BORDER. THIS WILL BRING SOME CAPES IN EXCESS OF 1500 J/KG.
THE SHEAR VECTORS WILL BE GENERALLY PARALLEL TO THE FRONT FOR SOME
POSSIBLE QLCS COMPLEXES ALONG WITH HELICITY > 300. HEIGHTS ACROSS THE
SOUTHEAST THOUGH ARE A LITTLE HIGH FOR THIS TIME OF THE YEAR. SPC
SREF...CIPS AND NAM MODELS POINT THE GREATEST SEVERE RISK ALONG THE
NATCHEZ TRACE CORRIDOR...WHERE THE HEIGHTS ARE A LITTLE MORE
CONDUCIVE. IF THIS TREND CONTINUES MAY CONSIDER PUTTING THAT AREA IN
AN ELEVATED RISK IN FUTURE MODEL RUNS. SO WILL KEEP THE LIMITED RISK
FOR NOW. THE COLD FRONT WILL EXIT THE REGION DURING THE EVENING THUS
ENDING THE SEVERE RISK.
LOOKING AT THE HEAVY RAIN RISK. PWATS WILL INCREASE TO AROUND 1.7
INCHES WHICH IS THE HIGHER AVERAGE PERCENTILE FOR THIS TIME OF
YEAR...WHICH SPELLS EFFICIENT RAINS. MODELS AND HPC ARE GENERALLY
GOING FOR 1-2 INCHES WITH LOCALLY INCH AMOUNTS POSSIBLE ALONG AND
AHEAD OF THE COLD FRONT. THIS WILL ADD TO OUR RECENT RAINS FOR
SATURATED SOIL CONDITIONS. SO WILL KEEP THE LIMITED RISK FOR
FLOODING FOR FRIDAY INTO SATURDAY. UNLESS THE MODELS SIGNAL
HIGHER RAINFALL AMOUNTS IN FUTURE MODEL RUNS...NO FLOOD WATCH WILL
BE CONSIDERED AT THIS TIME.
THE RAINS WILL EXIT THE REGION ON SUNDAY MORNING. HIGH PRESSURE WILL
SETTLE ACROSS THE REGION ON MONDAY. SO DRY AND COOL CONDITIONS WILL
PREVAIL FOR SUNDAY THROUGH WEDNESDAY. ANOTHER SURGE OF COOL AIR WILL
PUSH INTO THE REGION FOR TUESDAY INTO WEDNESDAY. WITH THIS AIRMASS
IT LOOKS LIKE THE BEST PART OF THIS AIRMASS WILL MISS THE REGION
TO THE NORTH. ON THURSDAY SHORTWAVE RIDGING WILL BUILD IN FROM THE
WEST AS LOW LEVEL RETURN FLOW COMES IN FOR SOME SHOWERS IN THE
SOUTHWEST BY EARLY FRIDAY./17/
&&
.AVIATION...VFR CONDITIONS WILL CONTINUE THROUGH AT LEAST EARLY
AFTERNOON AT MOST TERMINALS...BUT THE MID CLOUD DECK WILL GRADUALLY
LOWER THROUGH THE DAY...LIKELY REACHING MVFR CATEGORY TONIGHT IN ALL
AREAS EXCEPT AROUND MEI AND HBG. LIGHT RAIN WILL SPREAD EASTWARD INTO
THE REGION THIS MORNING...BECOMING MODERATE LATER ON TONIGHT. THIS
MAY BRING VISIBILITY REDUCTIONS TO MVFR ESPECIALLY AT NORTHWEST
TERMINALS WHERE MORE SUBSTANTIAL RAINFALL IS EXPECTED THROUGH THE TAF
PERIOD. CEILING AND OCCASIONAL VISIBILITY REDUCTIONS WILL LIKELY
PERSIST THROUGH THE WEEKEND. /DL/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 47 43 52 52 / 34 86 85 67
MERIDIAN 52 44 52 52 / 17 75 86 66
VICKSBURG 43 41 50 50 / 61 91 87 75
HATTIESBURG 57 48 60 60 / 21 64 71 50
NATCHEZ 45 43 56 55 / 42 86 75 71
GREENVILLE 40 38 45 44 / 93 95 93 82
GREENWOOD 44 39 47 47 / 91 91 91 74
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
DL/17
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
423 PM CST Thu Jan 1 2015
.SHORT TERM: (Tonight and Friday)
Issued at 338 PM CST Thu Jan 1 2015
The area is sandwiched between high pressure to the south and a trof
of low pressure up across the Upper Midwest. Southwest flow is the
result and temperatures have rebounded into the mid and upper 30s
across the entire area. With abundant cloud cover and weak
southwest flow continuing tonight, expect that lows tonight will be
several degrees warmer tonight than they were last night. Most
areas should get back down below freezing again, but think temps
should stay mostly in the upper 20s to low 30s across the majority
of the area (with the exception of northern MO and west central IL
where clouds should be thinner allowing for more radiational
cooling). NAM, GFS, and RAP develop some weak moisture convergence
on the 850mb baroclinic zone Friday morning just south of the STL
Metro area. While the GFS says dry, the NAM and to a lesser extent
the RAP do print out a little very light QPF. 4km NCEP and NSSL WRF
models also show very light QPF Friday morning, and light simulated
radar returns as well. Therefore, feel there`s enough signal to
bump up PoPs slightly for Friday morning along and southeast of
I-44/US-50. P-types will likely start out as a little rain/sleet
mix and where temps are below freezing there could be a bit of
glaze, but amounts look very light. Precip should turn quickly to
light rain or just sprinkles with a couple of hours of sunrise, and
highs look to be in the mid to upper 30s across the area on Friday.
Carney
.LONG TERM: (Friday Night through Next Thursday)
Issued at 421 PM CST Thu Jan 1 2015
Models are coming into better consensus with the storm system for
Friday night and Saturday. GFS and NAM continue to warm up bit by
bit. Most recent partial thickness forecasts show all critical
thickness lines for rain/snow well up into northern
Missouri/southern Iowa by the time the precipitation starts on
Friday night. Forecast soundings also have little or no cold layer
in the low levels indicating that sleet is becoming less and less
likely. So have more or less confined any chances of sleet to
northern zones Friday evening, changing over to all rain and
freezing rain where surface temperatures dictate. Think any
accumulations of freezing rain will be minor due to warm ground
temperatures and diabatic warming due to latent heat release.
Temperatures should warm above freezing after sunrise on Saturday
morning at any rate which should stop any ice accumulation. Think
the greatest amount of accumulation will be over northern MO and
west central IL and amounts should be between a trace and 0.05 inch.
Dry slot should wrap around into the storm on Saturday afternoon
which will likely make the rain slack off and even end across
southern portions of the area. Cold front moves through Saturday
evening with the tail end of the def-zone clipping our area.
Guidance seems to want to keep the majority of the QPF out of our
area over northwest Missouri and southern Iowa. However, it looks
like our northwest counties could get clipped with an inch or two of
snow before all the shouting is over.
Remainder of the forecast looks cold and dry as a longwave trof
deepens over the eastern CONUS. This will allow a couple of Arctic
air intrusions into the lower 48...one on Sunday and Monday behind
the weekend storm, and another midweek. This should keep
temperatures well below normal through the end of the forecast
period.
Carney
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1142 AM CST Thu Jan 1 2015
General thickening and lowering cloud deck trend is expected over
the next 30 hours as southerly flow continues in the lower
atmosphere. Have not introduced precipitation into the forecast at
this time as the majority is forecast to remain south of the
terminals. That being said, a few models are showing some light
QPF edging toward the St. Louis Metro terminals early tomorrow
morning. Depending on surface temperature this could be DZ or
FZDZ if it occurs. Am not confident enough in this occuring to
include into the forecast at this time. Light southwest to south
wind expected to continue.
Specifics for KSTL:
Only concern is for light drizzle or freezing drizzle early Friday
morning. Confidence too low at this point to include in the
forecast - but something to keep an eye on. Otherwise, general
thickening and lowering cloud trend is forecast with a light
southwest wind.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 29 38 34 41 / 10 20 80 90
Quincy 23 34 29 35 / 5 5 50 80
Columbia 27 37 31 38 / 10 10 80 80
Jefferson City 28 38 32 40 / 10 10 80 80
Salem 29 37 33 43 / 10 10 80 90
Farmington 30 38 33 43 / 20 20 80 90
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
339 PM CST Thu Jan 1 2015
.SHORT TERM: (Tonight and Friday)
Issued at 338 PM CST Thu Jan 1 2015
The area is sandwiched between high pressure to the south and a trof
of low pressure up across the Upper Midwest. Southwest flow is the
result and temperatures have rebounded into the mid and upper 30s
across the entire area. With abundant cloud cover and weak
southwest flow continuing tonight, expect that lows tonight will be
several degrees warmer tonight than they were last night. Most
areas should get back down below freezing again, but think temps
should stay mostly in the upper 20s to low 30s across the majority
of the area (with the exception of northern MO and west central IL
where clouds should be thinner allowing for more radiational
cooling). NAM, GFS, and RAP develop some weak moisture convergence
on the 850mb baroclinic zone Friday morning just south of the STL
Metro area. While the GFS says dry, the NAM and to a lesser extent
the RAP do print out a little very light QPF. 4km NCEP and NSSL WRF
models also show very light QPF Friday morning, and light simulated
radar returns as well. Therefore, feel there`s enough signal to
bump up PoPs slightly for Friday morning along and southeast of
I-44/US-50. P-types will likely start out as a little rain/sleet
mix and where temps are below freezing there could be a bit of
glaze, but amounts look very light. Precip should turn quickly to
light rain or just sprinkles with a couple of hours of sunrise, and
highs look to be in the mid to upper 30s across the area on Friday.
Carney
.LONG TERM: (Tonight through Wednesday)
Issued at 345 AM CST Thu Jan 1 2015
(Tonight through Saturday)
The approaching system to impact the region thru the weekend
continues to be the forecast focus.
The upper low, currently over the swrn U.S., shud have been well
sampled last evening which increases confidence in the latest mdl
guidance. However, with differences among mdl solns, that confidence
is reduced. A quick note that the 00z GFS soln has dewpoint
initialization problems once again. This time, it appears the bad
data is washed out within 18 to 24 hrs, at least in this region.
Otherwise, mdls are in good agreement thru 12z Fri. However,
differences quickly emerge beyond this time. The NAM/local WRF are a
fast soln, with the GEM being a slow soln and the ECMWF/GFS/GEFS
between these extremes tho still not in agreement with one another.
Have trended twd the ECMWF/GFS/GEFS solns thru this period. These
solns seem most logical given the timing and placement of the
upstream jet.
Overall, main forecast changes are precip onset quicker as well as
warmer temps. Mdls have a more shallow cold air wedge N of the
wrmfnt as the system approaches. Have therefore trended p-types twd
a RA vs. FZRA and reduced mention of IP. However, the nwd
advancement of the wrmfnt slows greatly Fri night into Sat. Have
kept mention of IP across nrn portions of the CWA during this time
where the cold air shud be deep enuf for precip to refreeze. The
warm air aloft is also colder during this time so cold air shud not
need to be as deep.
The ECMWF/GFS/GEFS have shifted the def zone precip further to the
NW on Sat night. The best chances for SN now appear to stretch from
KC to ern IA, just to the NW of the CWA. However, nrn and ern
portions of the CWA will likely see some SN as the def zone pulls
newd thru the region. Uncertainty with the placement of this precip
still exists and will continue until mdl solns are more consistent.
(Sunday through Wednesday)
Precip will have ended by the beginning of this period and
therefore, focus turns to temps thru the extd.
The ECMWF/GFS/GEFS remain in fairly good agreement thru the end of
the forecast period. Have therefore trended the forecast twd a
compromise thru the extd.
Cannot rule out a chance for precip sometime Mon night into Tues
and/or Wed. Since these systems are clippers, determining the
location of precip as the s/w drops thru the region will be
difficult and have low confidence in any one soln. Have kept PoPs
low for now.
Tilly
&&
.AVIATION: (For the 18z TAFs through 18z Friday Afternoon)
Issued at 1142 AM CST Thu Jan 1 2015
General thickening and lowering cloud deck trend is expected over
the next 30 hours as southerly flow continues in the lower
atmosphere. Have not introduced precipitation into the forecast at
this time as the majority is forecast to remain south of the
terminals. That being said, a few models are showing some light
QPF edging toward the St. Louis Metro terminals early tomorrow
morning. Depending on surface temperature this could be DZ or
FZDZ if it occurs. Am not confident enough in this occuring to
include into the forecast at this time. Light southwest to south
wind expected to continue.
Specifics for KSTL:
Only concern is for light drizzle or freezing drizzle early Friday
morning. Confidence too low at this point to include in the
forecast - but something to keep an eye on. Otherwise, general
thickening and lowering cloud trend is forecast with a light
southwest wind.
CVKING
&&
.PRELIMINARY POINT TEMPS/POPS:
Saint Louis 29 38 34 41 / 10 20 80 90
Quincy 23 34 29 35 / 5 5 50 80
Columbia 27 37 31 38 / 10 10 80 80
Jefferson City 28 38 32 40 / 10 10 80 80
Salem 29 37 33 43 / 10 10 80 90
Farmington 30 38 33 43 / 20 20 80 90
&&
.LSX WATCHES/WARNINGS/ADVISORIES:
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1259 AM EST THU JAN 1 2015
.SYNOPSIS...
A COLD FRONT WILL BRING THE POTENTIAL FOR LAKE SNOWS NORTH OF THE
NEW YORK THRUWAY THURSDAY NIGHT AND FRIDAY. ON SATURDAY AFTERNOON, A
STORM SYSTEM WILL MOVE IN FROM THE OHIO VALLEY, BRINGING A MIX OF
RAIN AND SNOW SATURDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
920 PM UPDATE...
THE LAKE EFFECT SNOW BAND OVER THE NORTH COUNTRY IS PROGGED TO
SKIRT NORTHERN ONEIDA COUNTY BETWEEN 7Z AND 10Z, BRINGING LIGHT
SNOW ACCUMULATION.
LATEST HRRR OUTPUT SUGGESTS A FEW FLURRIES OR LIGHT SNOW SHOWERS
MAY SNEAK INTO NORTHWESTERN STEUBEN COUNTY OVERNIGHT, DUE TO A
FLUCTUATING ERIE BAND. ADDED A SLIGHT CHC POP.
INTERIOR VALLEY TEMPERATURES ARE ALREADY NEAR PROJECTED OVERNIGHT
MINS, SO HAVE ADJUSTED MINS DOWNWARD.
1255 PM UPDATE...
LAKE SNOWS HV EXITED NRN ONEIDA CNTY THUS HV CANCELLED THE WARNING.
EXPECT LK EFFECT SNOW TO RMN WELL TO THE NORTH ON 240-250 FLOW THRU
THE OVRNGT WITH A SLIGHT WOBBLE TO THE SOUTH POSSIBLE TWD 09Z WITH
PERHAPS A FEW LGT SNOW SHOWERS AND/OR FLURRIES SNEAKING INTO EXTREME
NRN ONEIDA THRU DAYBREAK. VRY MINIMAL ACCUMS ARE EXPECTED WITH THIS
WOBBLE.
EXPECTING THAT LK ERIE BAND WL STAY A TAD TOO FAR WEST TO AFFECT
FINGER LAKES THIS EVNG INTO THE OVRNGT. NOTHING MORE THAN CLD CVR
EXPECTED ON 240 DEGREE FLOW. EXPECT MINS TO DROP INTO THE LWR TEENS
BY MRNG WITH SINGLE DIGITS POSSIBLE IN NOTORIOUSLY COLDER VALLEYS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SATURDAY/...
245 PM UPDATE...
LAKE EFFECT SNOW WL RMN NORTH OF CWA FOR MOST OF TOMORROW. THERE IS
SOME INDICATION THAT SNOW BAND WL MAKE A RUN TWD THE SOUTH ARND 18Z
BUT QUICKLY RETREAT BACK TO THE NORTH AS WINDS BACK TWD THE SOUTH
AHD OF APPCHG CDFNT. HV MAINLY CONFINED 20-30 POPS FOR LOCATIONS
NORTH OF THE NY THRUWAY DRG THE AFTN HRS. AS WINDS GO SRLY TEMPS WL
WARM INTO THE 20S BY AFTN, WRMR THAN TDA THO STILL BLO NRML VALUES.
CDFNT WL SLIP SOUTH THRU SRN CANADA LATE THUR NGT WITH LK SNOWS
DVLPNG AHD OF AND ALONG THIS BNDRY. MODELS SEEM TO BE IN PRETTY GOOD
AGREEMENT WITH FROPA WITH ONLY SVR HRS DIFFERENCE ON TIMING. THUS
EXPECT LK EFFECT SNOW SHOWERS TO COMMENCE LATE EVNG AND TWD MIDNIGHT
WITH LKLY BAND OF SNOW SHOWERS DROPPING INTO NRN ONEIDA AFTER 08Z.
WL ALLOW LATER SHIFTS TO GET A BETTER HANDLE ON ANY POTENTIAL
HEADLINES FOR LK EFFECT EVENT TOMORROW NIGHT/FRI MRNG. GFS AND NAM
DIFFER ON HOW LONG FLOW WL BE ALIGNED FOR FAVORABLE LK SNOWS ON
FRIDAY. NAM PUSHES FRONT THRU QUICKLY AND ALLOWS DRIER AIR TO
DISRUPT SNOWS DRG THE AFTN WHILE GFS KEEP INVERSION UP ARND 800MB
DRG THE AFTN HRS WITH FAIRLY STEADY STATE 280 DEGREE FLOW. FEEL IT
PRUDENT TO HOLD OFF ON ANY HEADLINES AT THIS TIME DUE TO VARYING
DEGREES OF UNCERTAINTY.
SFC HIPRES WL BEGIN BUILDING IN LATE FRI NGT THO SOME REMNANT SNOWS
MAY STILL EXIST NORTH OF THE THRUWAY THRU 06Z SAT. QUIET WX EXPECTED
UNTIL SYSTEM MVS IN FM THE SOUTH AFT 18Z SATURDAY. COLD AIR DAMMING
PROGGED ACRS ERN ZONES THRU END OF SHORT TERM PD THUS PCPN WL MV IN
AS ALL SNOW THRU 00Z SUN.
&&
.LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/...
MAIN FOCUS CONTINUES TO BE EARLY IN THE PERIOD WITH MED RANGE
MODELS IN PRETTY GOOD SYNOPTIC AGREEMENT THAT A PHASING SOUTHERN
STREAM/NORTHERN STREAM TROF WILL EJECT A SFC LOW THROUGH THE GREAT
LAKES REGION AND EASTERN ONTARIO/QUEBEC ON SATURDAY NIGHT AND
SUNDAY. THIS IS, OF COURSE, A TRACK THAT SIGNALS A SNOW-TO-MIX-TO-RAIN
EVENT FOR CNY/NEPA...FOLLOWED BY A DRY SLOT AND SHOWERY
PRECIPITATION ON THE BACK SIDE SUN-MON. GIVEN THE MODEL AGREEMENT
AND TRENDS...THIS IS A FAIRLY HIGH CONFIDENCE EVENT SO WILL
CONTINUE WITH CAT POP ALREADY OFFERED BY PREVIOUS FCST.
BEYOND MONDAY...A BROAD UPPER LEVEL TROF RESIDENT ACROSS THE
NORTHEAST AND GTLKS WILL MAINTAIN A COLD AND UNSTABLE WEST-NW FLOW
WITH TRANSIENT UPPER LEVEL WAVES GENERATING PERIODS OF LAKE SNOW
RESPONSES TO THE EAST OF ERIE AND ONTARIO. HAVE PRETTY MUCH
CONSTANT CHANCES FOR SNOW SHOWERS OR FLURRIES GOING THROUGH WEDNESDAY.
WITH THE EXCEPTION OF AN ABNORMALLY MILD SUNDAY...TEMPERATURES
WILL BE AT OR BELOW NORMAL DURING THIS TIME.
&&
.AVIATION /06Z THURSDAY THROUGH MONDAY/...
06Z UPDATE...
VFR STILL EXPECTED FOR THE NEXT 24 HOURS...EXCEPT LAKE EFFECT
-SHSN DROPPING INTO KRME AND THEN KSYR 03Z-06Z FRIDAY WITH
ASSOCIATED MVFR TO IFR VIS. UNTIL THEN...SCT-BKN CLOUDS AROUND
4-5 KFT FOR THE NY TERMINALS COURTESY OF LAKE ERIE MOISTURE
CARRYING ACROSS...AND ONLY PATCHY HIGH CIRRUS FOR KAVP 15-25 KFT
AGL. WINDS GENERALLY SW TO WSW 10-15 KTS WITH GUSTS DURING THE
DAYTIME HOURS IN LOWER 20S KT RANGE. KSYR-KRME WINDS SLIGHTLY
VEERING MORE WESTERLY TOWARDS END OF TAF PERIOD.
OUTLOOK...
FRI...LAKE EFFECT SNOW BAND IN VICINITY OF KRME-KSYR WITH
ASSOCIATED IFR VIS AT TIMES. LOCALIZED BRIEF MVFR-IFR SNOW SHOWERS
POSSIBLE KITH-KBGM.
SAT/SAT NGT...BECOMING IFR WITH SNOW DEVELOPING...CHANGING TO
WINTRY MIX AND OCNL RAIN/FRZG RAIN OVERNIGHT.
SUN...VFR. SCT RAIN SHOWERS.
MON...MVFR. SCT SNOW SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJP/PVF
NEAR TERM...DJP/PVF
SHORT TERM...PVF
LONG TERM...JAB
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1140 AM EST THU JAN 1 2015
.SYNOPSIS...
HIGH PRESSURE ACROSS THE SOUTHEASTERN U.S. WILL MOVE OFFSHORE
FRIDAY. RAIN CHANCES WILL INCREASE FRIDAY...WITH PERIODS OF RAIN
EXPECTED FRIDAY NIGHT AND SATURDAY AS A WARM FRONT APPROACHES. A
STRONG COLD FRONT MAY BRING A FEW THUNDERSTORMS SUNDAY AFTERNOON AND
NIGHT. CLEAR AND COLD CONDITIONS WILL OVERSPREAD THE CAROLINAS
MONDAY THROUGH WEDNESDAY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...VERY FEW CHANGES WERE NEEDED TO THE
FORECAST. SKIES ARE CLEAR WITH SATELLITE IMAGERY INDICATING CIRRUS
NOW APPROACHING THE SOUTHERN APPALACHIANS WILL BEGIN TO REACH THE
COAST THIS AFTERNOON. 12Z SOUNDINGS FROM MHX AND GSO LOOKED MUCH
LIKE THE 06Z MODELS INDICATED. BASED ON RECENT HRRR AND RUC
MODELS I HAVE INCREASED ONSHORE WINDS BY A FEW MPH THIS AFTERNOON
NEAR THE BEACHES WITH A WEAK SEABREEZE CIRCULATION. THIS ONSHORE
WIND WILL ALSO UNFORTUNATELY DRAG SOME PRETTY CHILLY AIR BACK IN
FROM THE OCEAN DURING THE MID-AFTERNOON HOURS.
INLAND HIGHS SHOULD RANGE FROM 54-57...WITH THE BEACHES RUNNING A
FEW DEGREES COOLER.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FOR THE MEDIUM AND LONG RANGE PACKAGE WILL
FAVOR THE GFS/ECMWF SOLUTION FOR THE PERIOD. H5 CUT OFF LOW ACROSS
THE SW RESULTS IN SPLIT FLOW ACROSS THE CONUS WITH RIDGING ACROSS
THE GULF COAST AND SE THROUGH THE PERIOD. EXPECT CLOUDS TO STREAM
INTO THE AREA AND THICKEN ON FRIDAY WITH PRECIPITATION CHANCES
INCREASING AS GULF MOISTURE BECOMES AVAILABLE. BELIEVE THE FIRST
HALF OF THE DAY SHOULD REMAIN DRY WITH CHANCE POPS DURING THE
LATER HALF OF FRIDAY. MAIN BULK OF PRECIPITATION STAYS TO OUR WEST
AS H5 LOW AND SURFACE LOW TRACK TO THE NE . H8 LOW LEVEL JET
INCREASE TO 30-35 KNOTS ACROSS THE REGION INCREASING LOW LEVEL
INSTABILITY AS EXIT REGION OF JET MOVES ACROSS THE CWA LATE
SATURDAY. WITH H5 SW FLOW WILL LOOK FOR MODERATING TEMPERATURES
THROUGH THE PERIOD. MOST OF THE PRECIPITATION WILL BE ON THE LIGHT
SIDE FRIDAY INTO SATURDAY WITH BREAKS THROUGHOUT THE PERIOD. WILL
STAY CLOSE TO GUIDANCE TEMPS FOR THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...EXPECT SUNDAY TO BE THE MORE ACTIVE DAY
OF THE WEEKEND WITH THE SPLIT FLOW PATTERN ACROSS THE US PHASING
IN ACROSS THE EASTERN HALF OF THE COUNTRY DURING THIS PERIOD AS H5
LOW AND SURFACE LOW MOVE INTO THE GREAT LAKES WITH DEVELOPING
TROUGH ACROSS THE CENTRAL U.S. H5 SW FLOW ACROSS THE SE WITH ABOVE
NORMAL TEMPERATURES EXPECTED ON SUNDAY AND THE GREATER RISK OF
RAIN AND POSSIBLE THUNDERSTORMS AHEAD OF ADVANCING COLD FRONT
MOVING INTO THE CAROLINAS. MODELS PEG THE FRONT ACROSS THE CWA
DURING LATE AFTERNOON INTO THE EARLY EVENING WITH BEST DYNAMICS AT
THIS TIME TO SUPPORT SOME ELEVATED CONVECTION AIDED BY DEPARTED H8
JET STREAK ACROSS THE REGION. WILL MAKE MENTION OF SLIGHT CHANCE
OF TSTM IN THE GRIDS FOR THE AFTERNOON/EVENING PERIOD. AS THE
FRONT EXITS THE COAST LATE SUNDAY AND H5 FLOW DAMPENS OUT BECOMING
MORE ZONAL FOR NEXT WEEK EXPECT SEASONABLE TO SLIGHTLY ABOVE CLIMO
TEMPS FOR NEXT WEEK FOR THE HIGHS AND CLEAR BUT COOLER OVERNIGHT
LOWS BELOW SLIGHTLY BELOW CLIMO AS CANADIAN HIGH PRESSURE BUILD IN
FORM THE WEST BUT STAYS TO OUR NORTH. GFS SEEMS TO WANT TO
DEVELOP A SURFACE LOW OFF THE SE COAST LATE IN THE PERIOD BUT ITS
FURTHER EAST THEN THE 31/00Z RUN OF LAST NIGHT AND WEAKER. THE
ECMWF HAS NOT HAD THIS FEATURE DURING THE PAST FEW RUNS SO WITH
HE GFS TRENDING WEAKER AND FURTHER EAST IT WILL NOT IMPACT THE
REGION TUESDAY INTO WEDNESDAY. H5 FLOW BECOMES MORE NW TOWARDS THE
END OF THE PERIOD AND WE START TO SEE COOLER TEMPS ARRIVE BY
THURSDAY INTO FRIDAY.
&&
.AVIATION /18Z THURSDAY THROUGH TUESDAY/...
AS OF 18Z...WEAK HIGH PRESSURE WILL SHIFT OFFSHORE TODAY...WITH
MAINLY WEAK SOUTHWESTERLY FLOW THIS AFTERNOON. THIS
EVENING...INCREASING CLOUDINESS AS THE NEXT SLUG OF MOISTURE RIDES
UP FROM THE SOUTHWEST. THE NAM IS A BIT MORE PESSIMISTIC THAN THE
GFS...WITH RAIN BEGINNING BEFORE DAYBREAK IN SPOTS. WILL GO WITH
MORE OF A BLEND DUE TO THE WEAK ISENTROPIC NATURE OF THINGS. WILL
INTRODUCE PRECIP FRIDAY BY MID TO LATE MORNING. CEILINGS AND
VISIBILITIES WILL LIKELY REMAIN VFR THROUGH THE END OF THE FORECAST
PERIOD...HOWEVER THINGS WILL DETERIORATE SHORTLY AFTER THAT.
EXTENDED OUTLOOK...VFR INTO FRI. CHANCE OF RAIN AND MVFR/TEMPO IFR
CONDITIONS FRI NIGHT THROUGH SUN. BECOMING VFR LATE SUN. VFR MON AND
TUE.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...VERY FEW CHANGES WERE NEEDED TO THE
FORECAST. BASED ON LATEST HRRR AND RUC MODELS I HAVE BUMPED UP WIND
SPEEDS BETWEEN 1-5 PM BY A FEW KNOTS NEAR THE BEACHES WITH A WEAK
SEABREEZE CIRCULATION. WIND SPEEDS STILL WILL REMAIN LESS THAN 10
KT. SEAS ARE BARELY 1-2 FEET AND SHOULD CHANGE LITTLE THROUGH THE
DAY. E THE RULE TONIGHT. SEAS WILL BE 2 FT OR LESS THROUGH THE
PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WEAK BUBBLE HIGH ACROSS THE COASTAL WATERS
DURING FRIDAY WILL RESULT IN RELATIVELY LIGHT WINDS AND SEAS LESS
THAN 10 KT WITH SEAS 1-2 FEET NEAR SHORE AND 2-3 OFFSHORE.
SATURDAY THE WINDS INCREASE FROM THE EAST AS COASTAL TROUGH
OFFSHORE INTERACTS WITH THE FRONT TO UR WEST IN TIGHTENING THE
PRESSURE GRADIENT ACROSS THE WATERS. BY MID DAY SATURDAY EAST
WINDS OF 10-15 KTS NEAR SHORE AND 15-20 KTS OFFSHORE WILL START TO
BUILD SEAS TO 2-4 NEAR SHORE AND 3-5 FEET OFFSHORE APPROACHING 6
FEET IN THE OUTER MARINE ZONES BY LATE SATURDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SMALL CRAFT ADVISORY CONDITIONS ARE
POSSIBLE SUNDAY AND MAYBE MONDAY AS FRONT APPROACHES THE COASTAL
WATERS AND WINDS VEER TO THE SW AND INCREASE TO 15-20 KTS NEAR
SHORE AND 20 TO 25 KTS OFFSHORE WITH BUILDING SEAS. WITH H8 JET
STREAK EXITING THE AREA AND THREAT OF ISOLATED THUNDERSTORMS SEAS
SHOULD REACT AND BUILD QUICKLY ON SUNDAY AND BE CHOPPY. FRONT
PASSES ACROSS THE COASTAL WATERS LATE SUNDAY NIGHT EARLY MONDAY
AND WINDS BECOME NORTHWEST STILL RATHER STRONG AT 15-20 KTS WILL
KEEP SEAS UP FOR THE EARLY PART OF MONDAY BEFORE SUBSIDING A BIT
BY AFTERNOON BUT NOT BY MUCH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...MAC
LONG TERM...MAC
AVIATION...43
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
935 AM EST THU JAN 1 2015
.SYNOPSIS...
HIGH PRESSURE ACROSS THE SOUTHEASTERN U.S. WILL MOVE OFFSHORE
FRIDAY. RAIN CHANCES WILL INCREASE FRIDAY...WITH PERIODS OF RAIN
EXPECTED FRIDAY NIGHT AND SATURDAY AS A WARM FRONT APPROACHES. A
STRONG COLD FRONT MAY BRING A FEW THUNDERSTORMS SUNDAY AFTERNOON AND
NIGHT. CLEAR AND COLD CONDITIONS WILL OVERSPREAD THE CAROLINAS
MONDAY THROUGH WEDNESDAY NEXT WEEK.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...VERY FEW CHANGES WERE NEEDED TO THE
FORECAST. SKIES ARE CLEAR WITH SATELLITE IMAGERY INDICATING CIRRUS
NOW APPROACHING THE SOUTHERN APPALACHIANS WILL BEGIN TO REACH THE
COAST THIS AFTERNOON. 12Z SOUNDINGS FROM MHX AND GSO LOOKED MUCH
LIKE THE 06Z MODELS INDICATED. BASED ON RECENT HRRR AND RUC
MODELS I HAVE INCREASED ONSHORE WINDS BY A FEW MPH THIS AFTERNOON
NEAR THE BEACHES WITH A WEAK SEABREEZE CIRCULATION. THIS ONSHORE
WIND WILL ALSO UNFORTUNATELY DRAG SOME PRETTY CHILLY AIR BACK IN
FROM THE OCEAN DURING THE MID-AFTERNOON HOURS.
INLAND HIGHS SHOULD RANGE FROM 54-57...WITH THE BEACHES RUNNING A
FEW DEGREES COOLER.
&&
.SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...FOR THE MEDIUM AND LONG RANGE PACKAGE WILL
FAVOR THE GFS/ECMWF SOLUTION FOR THE PERIOD. H5 CUT OFF LOW ACROSS
THE SW RESULTS IN SPLIT FLOW ACROSS THE CONUS WITH RIDGING ACROSS
THE GULF COAST AND SE THROUGH THE PERIOD. EXPECT CLOUDS TO STREAM
INTO THE AREA AND THICKEN ON FRIDAY WITH PRECIPITATION CHANCES
INCREASING AS GULF MOISTURE BECOMES AVAILABLE. BELIEVE THE FIRST
HALF OF THE DAY SHOULD REMAIN DRY WITH CHANCE POPS DURING THE
LATER HALF OF FRIDAY. MAIN BULK OF PRECIPITATION STAYS TO OUR WEST
AS H5 LOW AND SURFACE LOW TRACK TO THE NE . H8 LOW LEVEL JET
INCREASE TO 30-35 KNOTS ACROSS THE REGION INCREASING LOW LEVEL
INSTABILITY AS EXIT REGION OF JET MOVES ACROSS THE CWA LATE
SATURDAY. WITH H5 SW FLOW WILL LOOK FOR MODERATING TEMPERATURES
THROUGH THE PERIOD. MOST OF THE PRECIPITATION WILL BE ON THE LIGHT
SIDE FRIDAY INTO SATURDAY WITH BREAKS THROUGHOUT THE PERIOD. WILL
STAY CLOSE TO GUIDANCE TEMPS FOR THE PERIOD.
&&
.LONG TERM /SUNDAY THROUGH WEDNESDAY/...
AS OF 300 AM THURSDAY...EXPECT SUNDAY TO BE THE MORE ACTIVE DAY
OF THE WEEKEND WITH THE SPLIT FLOW PATTERN ACROSS THE US PHASING
IN ACROSS THE EASTERN HALF OF THE COUNTRY DURING THIS PERIOD AS H5
LOW AND SURFACE LOW MOVE INTO THE GREAT LAKES WITH DEVELOPING
TROUGH ACROSS THE CENTRAL U.S. H5 SW FLOW ACROSS THE SE WITH ABOVE
NORMAL TEMPERATURES EXPECTED ON SUNDAY AND THE GREATER RISK OF
RAIN AND POSSIBLE THUNDERSTORMS AHEAD OF ADVANCING COLD FRONT
MOVING INTO THE CAROLINAS. MODELS PEG THE FRONT ACROSS THE CWA
DURING LATE AFTERNOON INTO THE EARLY EVENING WITH BEST DYNAMICS AT
THIS TIME TO SUPPORT SOME ELEVATED CONVECTION AIDED BY DEPARTED H8
JET STREAK ACROSS THE REGION. WILL MAKE MENTION OF SLIGHT CHANCE
OF TSTM IN THE GRIDS FOR THE AFTERNOON/EVENING PERIOD. AS THE
FRONT EXITS THE COAST LATE SUNDAY AND H5 FLOW DAMPENS OUT BECOMING
MORE ZONAL FOR NEXT WEEK EXPECT SEASONABLE TO SLIGHTLY ABOVE CLIMO
TEMPS FOR NEXT WEEK FOR THE HIGHS AND CLEAR BUT COOLER OVERNIGHT
LOWS BELOW SLIGHTLY BELOW CLIMO AS CANADIAN HIGH PRESSURE BUILD IN
FORM THE WEST BUT STAYS TO OUR NORTH. GFS SEEMS TO WANT TO
DEVELOP A SURFACE LOW OFF THE SE COAST LATE IN THE PERIOD BUT ITS
FURTHER EAST THEN THE 31/00Z RUN OF LAST NIGHT AND WEAKER. THE
ECMWF HAS NOT HAD THIS FEATURE DURING THE PAST FEW RUNS SO WITH
HE GFS TRENDING WEAKER AND FURTHER EAST IT WILL NOT IMPACT THE
REGION TUESDAY INTO WEDNESDAY. H5 FLOW BECOMES MORE NW TOWARDS THE
END OF THE PERIOD AND WE START TO SEE COOLER TEMPS ARRIVE BY
THURSDAY INTO FRIDAY.
&&
.AVIATION /12Z THURSDAY THROUGH MONDAY/...
AS OF 12Z...CRE AND FLO WILL HAVE TO DEAL WITH FOG FOR THE FIRST
HOUR OR SO...OTHERWISE VFR CONDITIONS ARE EXPECTED THROUGH THE END
OF THE FORECAST PERIOD. HIGH PRESSURE WILL SHIFT OFFSHORE THIS
AFTERNOON...ALLOWING RETURN FLOW WITH INCREASING MID AND UPPER LEVEL
MOISTURE LATE THIS AFTERNOON THROUGH THE OVERNIGHT HOURS. SHOULD SEE
A MID CLOUD CEILING SOMETIME AFTER MIDNIGHT. THE INSULATING CLOUD
LAYER SHOULD KEEP FOG AT BAY. LIGHT SOUTHERLY FLOW TODAY WITH LIGHT
TO NEAR CALM WINDS TONIGHT.
EXTENDED OUTLOOK...VFR INTO FRI. CHANCE OF RAIN AND MVFR/TEMPO IFR
CONDITIONS FRI NIGHT THROUGH SUN. BECOMING VFR LATE SUN. VFR MON.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 930 AM THURSDAY...VERY FEW CHANGES WERE NEEDED TO THE
FORECAST. BASED ON LATEST HRRR AND RUC MODELS I HAVE BUMPED UP WIND
SPEEDS BETWEEN 1-5 PM BY A FEW KNOTS NEAR THE BEACHES WITH A WEAK
SEABREEZE CIRCULATION. WIND SPEEDS STILL WILL REMAIN LESS THAN 10
KT. SEAS ARE BARELY 1-2 FEET AND SHOULD CHANGE LITTLE THROUGH THE
DAY. E THE RULE TONIGHT. SEAS WILL BE 2 FT OR LESS THROUGH THE
PERIOD.
SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/...
AS OF 300 AM THURSDAY...WEAK BUBBLE HIGH ACROSS THE COASTAL WATERS
DURING FRIDAY WILL RESULT IN RELATIVELY LIGHT WINDS AND SEAS LESS
THAN 10 KT WITH SEAS 1-2 FEET NEAR SHORE AND 2-3 OFFSHORE.
SATURDAY THE WINDS INCREASE FROM THE EAST AS COASTAL TROUGH
OFFSHORE INTERACTS WITH THE FRONT TO UR WEST IN TIGHTENING THE
PRESSURE GRADIENT ACROSS THE WATERS. BY MID DAY SATURDAY EAST
WINDS OF 10-15 KTS NEAR SHORE AND 15-20 KTS OFFSHORE WILL START TO
BUILD SEAS TO 2-4 NEAR SHORE AND 3-5 FEET OFFSHORE APPROACHING 6
FEET IN THE OUTER MARINE ZONES BY LATE SATURDAY.
LONG TERM /SUNDAY THROUGH MONDAY/...
AS OF 300 AM THURSDAY...SMALL CRAFT ADVISORY CONDITIONS ARE
POSSIBLE SUNDAY AND MAYBE MONDAY AS FRONT APPROACHES THE COASTAL
WATERS AND WINDS VEER TO THE SW AND INCREASE TO 15-20 KTS NEAR
SHORE AND 20 TO 25 KTS OFFSHORE WITH BUILDING SEAS. WITH H8 JET
STREAK EXITING THE AREA AND THREAT OF ISOLATED THUNDERSTORMS SEAS
SHOULD REACT AND BUILD QUICKLY ON SUNDAY AND BE CHOPPY. FRONT
PASSES ACROSS THE COASTAL WATERS LATE SUNDAY NIGHT EARLY MONDAY
AND WINDS BECOME NORTHWEST STILL RATHER STRONG AT 15-20 KTS WILL
KEEP SEAS UP FOR THE EARLY PART OF MONDAY BEFORE SUBSIDING A BIT
BY AFTERNOON BUT NOT BY MUCH.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
NEAR TERM...RJD/TRA
SHORT TERM...MAC
LONG TERM...MAC
AVIATION...43
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
324 PM CST THU JAN 1 2015
.SHORT TERM...(THIS EVENING THROUGH FRIDAY NIGHT)
ISSUED AT 324 PM CST THU JAN 1 2015
FORECAST CHALLENGES FOR SHORT TERM WILL BE OVERNIGHT LOWS TONIGHT
FOLLOWED BY EVOLUTION OF A SNOW PRODUCING CLIPPER SYSTEM TOMORROW
NIGHT...TO INCLUDE SNOW AMOUNTS AND INTENSITIES MAINLY AFTER
MIDNIGHT INTO SUNDAY MORNING. THE ECMWF/GEM/GFS HAVE THE BEST
AGREEMENT FOR THIS SYSTEM AND WILL USE A ECMWF/GFS BLEND.
TONIGHT...CURRENT VIS SHOWS SOME CLEARING OVER PORTIONS OF THE
DEVILS LAKE BASIN AS WELL AS FRESH SNOW ACROSS PORTIONS OF
NORTHEAST ND AND THE NORTHERN RED RIVER VALLEY. MID CLOUD UPSTREAM
IN THE NW FLOW MAY ADVECT BACK INTO THE FAR NW AND TIMING OF THIS
CLOUD COVER WILL BE CRITICAL ON OVERNIGHT LOWS...AS WELL AS ONSET
OF RETURN FLOW ACROSS EASTERN ND BY MIDNIGHT. A WEAK LOW WILL
SKIRT THE NORTH TONIGHT...AND BRINGS SOME LIGHT SNOW TO THE
NORTHERN FORECAST AREA FROM MIDNIGHT THROUGH MID MORNING TOMORROW.
VERY LIGHT ACCUMULATIONS ARE EXPECTED. MEANWHILE...A CLIPPER WILL
DEVELOP ON THE LEE SIDE OF THE NORTHERN/CANADIAN ROCKIES. EXPECT
COLDEST TEMPERATURES OVER THE NORTHEASTERN FCST AREA ESPECIALLY
THE NORTHERN VALLEY WHERE SKIES SHOULD REMAIN CLEAR ENOUGH TO GET
EARLY LOWS BEFORE WARM ADVECTION BEGINS BY MORNING.
TOMORROW...CLIPPER SYSTEM BEGINS TO DROP INTO MT AND MOVE
EAST...NEARING THE ND STATE LINE AROUND 00Z. A WARM FRONTAL BNDRY
WILL LIFT NORTH AND HELP GENERATE SNOW MAINLY IN W AND CNTRL ND
ALONG THE INTL BORDER. MODELS DIFFER ON EASTWARD EXTEND OF
SNOW...WITH GEM/ECMWF/GFS REACHING THE NORTHERN VALLEY BY 00Z AND
THE NAM SLOWER AND DRIER IN THE AFTN HOURS. FOR THIS PERIOD
ONLY...LIKE THE SLOWER NAM AS IT WILL TAKE A WHILE TO SATURATE THE
COLUMN GIVEN THE DRY AIRMASS IN PLACE FROM NE FLOW TODAY AND
TONIGHT. SHOULD SEE SOME DEVELOPMENT IN NORTHEASTERN ND IN THE 21Z
TO 00Z SATURDAY TIME FRAME.
TOMORROW NIGHT...WELL ADVERTISED CLIPPER SYSTEM WILL MOVE ACROSS
CWA...HOWEVER EXACT TRACK OF SFC LOW STILL IN QUESTION. GENERALLY
THE SLIGHTLY SOUTHWARD GFS/ECMWF/GFS SOLUTION IS PREFERRED OVER
THE MORE NORTHERN NAM SOLUTION...ALTHOUGH ALL MODELS TRENDED NORTH
SINCE YESTERDAYS RUN. AN RIGHT ENTRANCE REGION WILL SET UP
GENERALLY OVER SOUTHEASTERN MANITOBA AS THE SFC LOW MOVES INTO
EASTERN DAKOTAS AFT MIDNIGHT SAT NIGHT. MODELS ARE SHOWING DECENT
ISENTROPIC LIFT AS WELL AS H300 TO H500 Q VECTOR CONVERGENCE OVER
PORTIONS OF NORTHEASTERN ND AND NORTHWEST MN. THESE INGREDIENTS
ARE BEST OVERLAPPED IN SOUTHEASTERN MB AND PORTIONS OF THE NE
CWA AND SHOULD HAVE SUFFICIENT ASCENT TO CREATE BANDED SNOWFALL.
DID INCREASE GFS-BASED SNOW RATIOS TO AROUND 25:1 IN THE FAR NE.
EXPECT TO SEE SOME AREAS OF HEAVY SNOWFALL ACROSS THE NORTH...BUT
STILL ENOUGH UNCERTAINTY ON EXACT COUNTIES TO HOLD OFF ON
UPGRADING HEADLINES TO A HEAVY SNOW WARNING AS MAIN IMPACTS WILL
BE IN THE THIRD PERIOD. IN GENERAL...OVER SIX INCHES OF SNOW IS
QUITE POSSIBLE IN COUNTIES ALONG THE INTERNATIONAL BORDER...WITH
HEAVIER SNOWFALL BEGINNING AFTER MIDNIGHT AND INCREASING THROUGH
MID MORNING SATURDAY.
.LONG TERM...(SATURDAY THROUGH THURSDAY)
ISSUED AT 324 PM CST THU JAN 1 2015
SATURDAY...CLIPPER WILL TRACK INTO THE LOWER GREAT LAKES AND WRAP
AROUND SNOWFALL SHOULD EXIT EASTERN ZONES BY OOZ SUNDAY. MOST
SIGNIFICANT ISSUE SATURDAY WILL BE INCREASING WINDS DUE TO TIGHT
PRESSURE GRADIENT FROM DEPARTING LOW AND STRONG COLD ADVECTION AS
ARCTIC AIR POURS IN TO REGION. THIS WILL GENERATE AREAS OF BLOWING
SNOW IN NORTHEASTERN ND BY NOONTIME SATURDAY. THE SOUTHWARD EXTEND
OF ANY BLOWING SNOW WILL BE DEPENDENT ON PLACEMENT OF ANY NEW
SNOW...WITH MOST FRESH SNOW FALLING NORTH OF THE HWY 200 CORRIDOR
AND THE HEAVIEST NORTH OF HWY 2. AGAIN...STILL SOME UNCERTAINTY ON
THE TRACK OF THE SFC LOW AND PLACEMENT OF SNOWFALL...BUT BLOWING
SNOW COULD BE AN ISSUE IN AT LEAST NE ND ON SAT AM.
SATURDAY NIGHT THROUGH SUNDAY...WINDS WILL TAPER DOWN IN THE
SOUTHERN VALLEY BY MID TO LATE SATURDAY EVENING. YET ANOTHER
ARCTIC AIR MASS WILL THEN MOVE INTO THE REGION AND CREATE SEVERAL
DAYS OF SUB ZERO TEMPERATURES FOR MUCH OF THE FORECAST AREA...WITH
SUNDAY HIGHS STRUGGLING TO MAKE IT OUT OF THE TEENS BELOW ZERO ON
SUNDAY IN THE NORTH.
SUNDAY NIGHT THROUGH THURSDAY...THE WORD FOR THE PERIOD IS COLD.
ARCTIC HIGH PRESSURE REMAINS IN PLACE OVER THE NORTHERN
PLAINS...WITH A POSSIBLE WEAK SYSTEM MOVING THROUGH MONDAY NIGHT.
THE GFS AND ECMWF BRING A WEAK REINFORCING SHORTWAVE THROUGH EARLY
IN THE WEEK...WITH A LOW PRESSURE CENTER MOVING JUST TO THE SOUTH OF
THE CWA AND PUTTING THE SOUTHERN COUNTIES IN THE GOOD DEFORMATION
ZONE. THE GEM ON THE OTHER HAND...IS DRY AND NAEFS PRECIP
PROBABILITIES ARE NOT THAT HIGH. THE BLENDED SOLUTION GIVES SOME LOW
POPS IN OUR SOUTH AND THAT SEEMS REASONABLE FOR NOW. TEMPERATURES
WILL CONTINUE TO REMAIN WELL BELOW SEASONAL AVERAGES WITH MANY
PLACES SEEING EVEN HIGHS IN THE NEGATIVE NUMBERS. TEMPS SHOULD BEGIN
TO MODERATE TOWARDS THE END OF THE PERIOD AS THERE ARE SIGNS OF
HEIGHT RISES AS THE MAIN UPPER TROUGH PULLS EAST.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 143 PM CST THU JAN 1 2015
TAF SITES HAVE ALL GONE VFR WITH CIGS BETWEEN 3000-7000 FT. SAT LOOP
SHOWS ACTUAL CLEARING MOVING INTO NORTHWESTERN MN...WHICH SHOULD
IMPACT KBJI...KTVF AND KGFK SHORTLY. THE QUESTION WILL BE HOW FAR
SOUTH THE CLEARING GOES TODAY. THE RAP HAS A DECENT HANDLE ON
CURRENT CONDITIONS AND HAS THE DRYING RUNNING OUT OF STEAM BEFORE
REACHING KFAR AND KDVL...SO LEANED TOWARDS THAT SOLUTION. EVEN AS
THERE IS SOME CLEARING IT WILL BE SHORT LIVED AS MOISTURE RETURNS
EARLY TONIGHT AS SOUTH WINDS BEGIN TO PICK UP AHEAD OF A LOW
PRESSURE SYSTEM. FOR NOW HAVE VFR CLOUDS MOVING BACK IN FIRST...THEN
ALL SITES GOING BACK DOWN TO MVFR BETWEEN 06Z AND 12Z FRIDAY. SOME
GUIDANCE SHOWS LIGHT FOG FORMATION BUT FOR NOW WILL LEAVE OUT
REDUCTIONS TO VIS. NORTH WINDS TODAY WILL BECOME LIGHT AND VARIABLE
THIS EVENING BEFORE PICKING UP OUT OF THE SOUTH BY THE END OF THE
PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR NDZ006>008-014>016-026-027-054.
MN...WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR MNZ001-004>009-013>017.
&&
$$
SHORT TERM...SPEICHER
LONG TERM...JR/SPEICHER
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS GRAND FORKS ND
144 PM CST THU JAN 1 2015
.UPDATE...
LATEST SFC OBS INDICATE N TO NNE FLOW IS BRINGING IN VERY DRY AIR
MASS WITH DEW POINTS AROUND 0 TO 7 F ACROSS MOST OF THE NORTHERN
PORTIONS OF CWA...TRANSITIONING QUICKLY TO 15 TO 20 F ALONG AND
SOUTH OF THE HWY 200 CORRIDOR. CONSEQUENTLY NOT SEEING ANY REPORTS
OF LIGHT SNOW ACROSS NORTHERN SITES WITH THE DRY LOW LYR...WHILE
THERE ARE STILL A FEW REPORTS ACROSS OTTER TAIL AND GRANT
COUNTIES. ISENTROPIC CHARTS INDICATE CONDENSATION PRESSURE
DEFICITS CLIMB QUICKLY BY 18Z...WHICH SHOULD HELP SCOUR OUT
REMAINING CLOUD COVER AND PUSH TO THE FAR SOUTHERN VALLEY ANY AFTN
CLOUD COVER. WILL REMOVE POPS FOR ALL BUT SE AND E CNTRL ZONES FOR
REMAINDER OF MORNING BUT KEEP MENTION OF FLURRIES THROUGHOUT AREAS
OF CLOUD COVER. WILL ALSO ADJUST AFTN SKY FOR EXPECTED TRENDS. LOW
SUN ANGLE MAKING IT DIFFICULT TO SEE HOW QUICKLY CLEARING LINE IS
MOVING...SO MAY NEED TO MAKE FURTHER ADJUSTMENTS AT 19Z UPDATE.
UPDATE ISSUED AT 743 AM CST THU JAN 1 2015
HIGH TEMPS TODAY TWEAKED A BIT WITH TIMING OF COLD AIR CURRENTLY
MOVING INTO THE AREA. OTHERWISE NO CHANGES MADE AT THIS UPDATE.
&&
.SHORT TERM...(TODAY THROUGH FRIDAY)
ISSUED AT 403 AM CST THU JAN 1 2015
UPPER LEVEL TROUGHS OVER THE GULF OF AK AND THE UPPER LEVEL LOW OVER
THE DESERT SOUTHWEST FORECAST TO NEARLY PHASE UP OVER THE CENTRAL
PLAINS BY THE END OF THE PERIOD. SURFACE LOW FORECAST TO BOMB OUT
FROM THE LOWER OH VALLEY INTO THE GREAT LAKE STATES BY THE END OF
THE PERIOD. LEE SIDE SURFACE TROUGH TO DEVELOP OVER MT/WY AND WILL
MOVE OUT INTO SD BY 12Z SAT. WILL BE LIVING ALONG THE BAROCLINIC
ZONE THE NEXT COUPLE DAYS. IN THE MEANTIME QUITE FAST TRANSITIONS
WITH WARM AIR TO THE SOUTH AND WEST AND COLD AIR NORTH AND EAST.
MODEL SOUNDINGS INDICATED LOWER LAYERS SATURATE QUICKLY THIS MORNING
AHEAD OF A COLD FRONT. COLD AIR OVER SOUTHERN CANADA WILL BRUSH THE
AREA FOR MAINLY THIS MORNING. WARM ADVECTION WILL QUICKLY RETURN
TONIGHT. LIGHT SNOW EXPECTED ACROSS THE AREA THIS MORNING WITH SHORT
WAVE/JET STREAK MOVING THROUGH.
WILL ADD LIGHT SNOW FOR FRI MORNING WITH WARM ADVECTION AND
BAROCLINIC ZONE IN THE AREA. OTHERWISE MORE SIGNIFICANT SNOW
EXPECTED TO START FRI AFTERNOON. THROUGH SAT AFTERNOON. POTENTIAL
FOR 6 OR MORE INCHES OF SNOW GENERALLY NORTH OF HIGHWAY 2. WILL
ISSUE A WINTER STORM WATCH FOR THAT AREA.
.LONG TERM...(FRIDAY NIGHT THROUGH WEDNESDAY)
ISSUED AT 403 AM CST THU JAN 1 2015
FOR SUNDAY THROUGH WEDNESDAY...FORECAST AREA IS DOMINATED BY AN
UPPER LEVEL TROUGH AND ARCTIC HIGH PRESSURE. 00Z GFS/ECMWF PRETTY
SIMILAR IN OVERALL PATTERN THOUGH ECMWF IS A BIT COLDER WITH ARCTIC
AIR. COLDEST DAY SUNDAY...SOME CLOUDS AND RISK OF VERY LIGHT SNOW
WILL MOVE ALONG THE SOUTH AND NORTH DAKOTA BORDER MONDAY AS A SYSTEM
MOVES INTO THE CENTRAL PLAINS PER GFS...BUT ECMWF KEEPS IT WELL
SOUTH DUE TO STRONGER HIGH. HIGH PRESSURE AND CONTINUED BELOW NORMAL
TEMPS TUES-WED PERIOD. TEMP MODERATION SEEMS LIKELY END OF NEXT
WEEK.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z FRIDAY AFTERNOON)
ISSUED AT 143 PM CST THU JAN 1 2015
TAF SITES HAVE ALL GONE VFR WITH CIGS BETWEEN 3000-7000 FT. SAT LOOP
SHOWS ACTUAL CLEARING MOVING INTO NORTHWESTERN MN...WHICH SHOULD
IMPACT KBJI...KTVF AND KGFK SHORTLY. THE QUESTION WILL BE HOW FAR
SOUTH THE CLEARING GOES TODAY. THE RAP HAS A DECENT HANDLE ON
CURRENT CONDITIONS AND HAS THE DRYING RUNNING OUT OF STEAM BEFORE
REACHING KFAR AND KDVL...SO LEANED TOWARDS THAT SOLUTION. EVEN AS
THERE IS SOME CLEARING IT WILL BE SHORT LIVED AS MOISTURE RETURNS
EARLY TONIGHT AS SOUTH WINDS BEGIN TO PICK UP AHEAD OF A LOW
PRESSURE SYSTEM. FOR NOW HAVE VFR CLOUDS MOVING BACK IN FIRST...THEN
ALL SITES GOING BACK DOWN TO MVFR BETWEEN 06Z AND 12Z FRIDAY. SOME
GUIDANCE SHOWS LIGHT FOG FORMATION BUT FOR NOW WILL LEAVE OUT
REDUCTIONS TO VIS. NORTH WINDS TODAY WILL BECOME LIGHT AND VARIABLE
THIS EVENING BEFORE PICKING UP OUT OF THE SOUTH BY THE END OF THE
PERIOD.
&&
.FGF WATCHES/WARNINGS/ADVISORIES...
ND...WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR NDZ006>008-014>016-026-027-054.
MN...WINTER STORM WATCH FROM FRIDAY AFTERNOON THROUGH SATURDAY
AFTERNOON FOR MNZ001-004>009-013>017.
&&
$$
UPDATE...SPEICHER
SHORT TERM...HOPPES
LONG TERM...RIDDLE
AVIATION...SPEICHER
AREA FORECAST DISCUSSION
NWS NORMAN OK
1130 AM CST THU JAN 1 2015
.AVIATION...
LIGHT RAIN AND FREEZING RAIN WILL CONTINUE ACROSS SOUTHERN AND
EASTERN OKLAHOMA THROUGH 00Z FRI. THEREAFTER...MAINLY DRY
CONDITIONS EXPECTED THROUGH EARLY FRI MORNING. HOWEVER...MVFR TO
IFR CIGS AND VSBYS WILL LIKELY PERSIST FROM KSPS/KLAW TO
KCSM/KHBR. WINDS WILL SHIFT AROUND TO THE NORTH EARLY FRI...AND
FREEZING DRIZZLE AND FREEZING RAIN WILL BUILD INTO SOUTHWESTERN
TERMINALS BY 12Z...SPREADING NORTHWARD THROUGH THE DAY. FREEZING
RAIN MAY CHANGE OVER TO RAIN DURING THE AFTERNOON HOURS FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 555 AM CST THU JAN 1 2015/
AVIATION...
01/12Z TAFS...PRIMARILY MVFR/IFR CONDITIONS EXPECTED MOST OF THE
FORECAST PERIOD. AREAS OF FREEZING DRIZZLE/FREEZING RAIN EXPECTED
TO AFFECT ALL BUT FAR NORTHERN OKLAHOMA TERMINALS...WHERE PRECIP
WILL MAINLY BE SNOW THIS MORNING INTO EARLY AFTERNOON. MOST
PERSISTENT LIGHT FZDZ/FZRA EXPECTED NEAR AND SOUTH OF KHBR AND
KOUN. BREAK IN MOST OF THE PRECIP EXPECTED TOWARD AND AFTER 20-22Z
BUT CIGS/VSBY WILL KEEP IFR/MVFR CONDITIONS GOING ALL BUT NORTHERN
OKLAHOMA SITES. WIDESPREAD FREEZING/FROZEN PRECIP EXPECTED TO
SPREAD OVER REGION JUST AFTER THIS TAF PERIOD AND LASTING MOST OF
THE DAY FRIDAY.
PREV DISCUSSION... /ISSUED 452 AM CST THU JAN 1 2015/
DISCUSSION...
WAVE NUMBER ONE OF PRECIPITATION IS ONGOING ACROSS SOUTHERN
OKLAHOMA AND WESTERN TEXAS THIS MORNING. RADAR TRENDS SHOW
ENHANCEMENT OF RADAR REFLECTIVITY IN THE TEXAS PANHANDLE. THE
CELLULAR STRUCTURE AND ENHANCED REFLECTIVITY SUGGEST THIS IS
ASSOCIATED WITH SLEET. BOTH THE HRRR AND RAP SUGGEST THIS WILL
CONTINUE TO DEVELOP AND MOVE EASTWARD WITH THE POTENTIAL FOR A
WINTRY MIX EVEN NORTH OF I-40 THIS MORNING INTO EARLY AFTERNOON.
THEREFORE...DECIDED TO EXPAND THE WINTER WEATHER ADVISORY FARTHER
NORTH.
WAVE NUMBER ONE WILL EXIT THE AREA LATE AFTERNOON INTO EARLY
EVENING. ATTENTION THEN TURNS TO SECOND WAVE OF PRECIPITATION THAT
IS ASSOCIATED WITH THE MAIN UPPER LEVEL LOW. A MORE WIDESPREAD
PRECIPITATION EVENT IS EXPECTED. PRECIPITATION WILL LIKELY DEVELOP
IN WESTERN NORTH TEXAS EARLY FRIDAY MORNING AND LIFT NORTHEASTWARD
THROUGH THE DAY FRIDAY. BECAUSE OF THE EARLY ONSET...THERE IS
CONCERN OF A SIGNIFICANT ICING EVENT ACROSS WESTERN NORTH TEXAS.
THE FORECAST ON FRIDAY WILL DEPEND ON THE EVOLUTION OF THE SFC 32F
WETBULB TEMPERATURE. LATEST GUIDANCE SUGGESTS THIS COULD BE VERY
CLOSE TO THE I-44 CORRIDOR BY FRIDAY AFTERNOON. OPTED FOR A MIX OF
RAIN/FREEZING RAIN ALONG I-44...WITH A FREEZING RAIN/SLEET MIX
NORTHWEST AND ALL RAIN SOUTHEAST.
A TRANSITION TO SNOW WILL OCCUR LATE FRIDAY INTO SATURDAY AS THE
UPPER LEVEL LOW PASSES THROUGH OKLAHOMA. BOTH THE PARALLEL GFS AND
ECMWF STILL SUGGEST THERE COULD BE ACCUMULATING SNOW IN NORTHERN
OKLAHOMA SATURDAY. THERE IS THE POTENTIAL THERE COULD BE ENOUGH
ACCUMULATING SNOW FOR HEADLINES. THE REST OF OKLAHOMA AND WESTERN
NORTH TEXAS COULD BE DRY SLOTTED SATURDAY.
AFTER COLLABORATION WITH SURROUNDING OFFICES...DECIDED TO HOLD
OFF ON ANY HEADLINES FOR FRIDAY AND SATURDAY. NEVERTHELESS...HEADLINES
WILL LIKELY BE REQUIRED FOR PARTS OF THE AREA FRIDAY INTO SATURDAY
FOR ACCUMULATING ICE AND/OR SNOW. STAY-TUNED!
BEYOND SATURDAY...A RATHER COLD DAY IS EXPECTED ON SUNDAY BEHIND THE
STORM SYSTEM. TEMPERATURES WILL SLOWLY MODERATE BEFORE ANOTHER COLD
FRONT APPROACHES THE REGION AROUND MID-WEEK. THE FORECAST IS DRY
BEYOND SATURDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 27 34 31 39 / 20 60 70 30
HOBART OK 24 33 29 40 / 20 50 60 20
WICHITA FALLS TX 29 34 32 43 / 60 80 70 20
GAGE OK 18 33 22 35 / 0 20 40 50
PONCA CITY OK 24 33 30 37 / 10 30 70 40
DURANT OK 32 36 36 46 / 50 80 80 40
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR OKZ012-
013-016>048-050>052.
TX...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
06/84
AREA FORECAST DISCUSSION
NWS TULSA OK
1124 AM CST THU JAN 1 2015
.AVIATION...
CONCERNING TAF SITES KTUL/KRVS/KBVO/KMLC/KXNA/KFYV/KFSM/KROG.
CURRENTLY SEEING VFR CONDITIONS ACROSS EASTERN OKLAHOMA AND
WESTERN ARKANSAS. HOWEVER...THAT WILL CHANGE OVER THE NEXT
FEW HOURS AS CONDITIONS DETERIORATE. WILL SEE IFR CONDITIONS
LATER TONIGHT AS LOW CLOUDS AND FOG DEVELOP ACROSS THE AREA.
&&
.PREV DISCUSSION... /ISSUED 942 AM CST THU JAN 1 2015/
DISCUSSION...
THE FORECAST FOR TODAY HAS A HUGE BUST POTENTIAL. IT ALL HINGES
ON THE LOCATION OF THE FREEZING LINE AND IF THE HRRR QPF PANS
OUT. THE FREEZING LINE IS NOW LOCATED ACROSS SOUTHEAST OKLAHOMA
INTO WEST-CENTRAL ARKANSAS. HOWEVER...THERE MAY STILL SOME POCKETS OF
BELOW FREEZING TEMPERATURES IN THIS AREA. IT IS BASICALLY GOING TO
BE RACE BETWEEN THE PRECIPITATION SHIELD AND THE FREEZING LINE...TO
DETERMINE THE PRECIPITATION TYPE ACROSS NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS THIS AFTERNOON. WILL CONTINUE WINTER WEATHER ADVISORY AS IT
IS FOR NOW WITH MAINLY FREEZING RAIN AND SLEET EXPECTED ACROSS NORTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS THIS AFTERNOON. LIGHT ACCUMULATIONS OF
ICE ARE EXPECTED. HOWEVER...TRAVEL IMPACTS CAN BE GREAT WITH EVEN A THIN
GLAZE OF ICE. WILL MORE THAN LIKELY SEE MAINLY RAIN ACROSS THE SOUTH
WITH PATCHES OF SLEET.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM THURSDAY FOR OKZ060-OKZ061-
OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-OKZ068-OKZ069-
OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL 6 PM THURSDAY FOR ARZ001-ARZ002-
ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
AVIATION...10
AREA FORECAST DISCUSSION
NWS TULSA OK
942 AM CST THU JAN 1 2015
.DISCUSSION...
THE FORECAST FOR TODAY HAS A HUGE BUST POTENTIAL. IT ALL HINGES
ON THE LOCATION OF THE FREEZING LINE AND IF THE HRRR QPF PANS
OUT. THE FREEZING LINE IS NOW LOCATED ACROSS SOUTHEAST OKLAHOMA
INTO WEST-CENTRAL ARKANSAS. HOWEVER...THERE MAY STILL SOME POCKETS OF
BELOW FREEZING TEMPERATURES IN THIS AREA. IT IS BASICALLY GOING TO
BE RACE BETWEEN THE PRECIPITATION SHIELD AND THE FREEZING LINE...TO
DETERMINE THE PRECIPITATION TYPE ACROSS NORTHEAST OKLAHOMA AND NORTHWEST
ARKANSAS THIS AFTERNOON. WILL CONTINUE WINTER WEATHER ADVISORY AS IT
IS FOR NOW WITH MAINLY FREEZING RAIN AND SLEET EXPECTED ACROSS NORTHEAST
OKLAHOMA AND NORTHWEST ARKANSAS THIS AFTERNOON. LIGHT ACCUMULATIONS OF
ICE ARE EXPECTED. HOWEVER...TRAVEL IMPACTS CAN BE GREAT WITH EVEN A THIN
GLAZE OF ICE. WILL MORE THAN LIKELY SEE MAINLY RAIN ACROSS THE SOUTH
WITH PATCHES OF SLEET.
&&
.TSA WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM THURSDAY FOR OKZ049-OKZ053-
OKZ060-OKZ061-OKZ062-OKZ063-OKZ064-OKZ065-OKZ066-OKZ067-
OKZ068-OKZ069-OKZ070-OKZ071-OKZ072-OKZ073-OKZ074-OKZ075-
OKZ076.
AR...WINTER WEATHER ADVISORY UNTIL 6 PM THURSDAY FOR ARZ001-ARZ002-
ARZ010-ARZ011-ARZ019-ARZ020-ARZ029.
&&
$$
SHORT TERM...10
AREA FORECAST DISCUSSION...UPDATED
NWS NORMAN OK
555 AM CST THU JAN 1 2015
.AVIATION...
01/12Z TAFS...PRIMARILY MVFR/IFR CONDITIONS EXPECTED MOST OF THE
FORECAST PERIOD. AREAS OF FREEZING DRIZZLE/FREEZING RAIN EXPECTED
TO AFFECT ALL BUT FAR NORTHERN OKLAHOMA TERMINALS...WHERE PRECIP
WILL MAINLY BE SNOW THIS MORNING INTO EARLY AFTERNOON. MOST
PERSISTENT LIGHT FZDZ/FZRA EXPECTED NEAR AND SOUTH OF KHBR AND
KOUN. BREAK IN MOST OF THE PRECIP EXPECTED TOWARD AND AFTER 20-22Z
BUT CIGS/VSBY WILL KEEP IFR/MVFR CONDITIONS GOING ALL BUT NORTHERN
OKLAHOMA SITES. WIDESPREAD FREEZING/FROZEN PRECIP EXPECTED TO
SPREAD OVER REGION JUST AFTER THIS TAF PERIOD AND LASTING MOST OF
THE DAY FRIDAY.
&&
.PREV DISCUSSION... /ISSUED 452 AM CST THU JAN 1 2015/
DISCUSSION...
WAVE NUMBER ONE OF PRECIPITATION IS ONGOING ACROSS SOUTHERN
OKLAHOMA AND WESTERN TEXAS THIS MORNING. RADAR TRENDS SHOW
ENHANCEMENT OF RADAR REFLECTIVITY IN THE TEXAS PANHANDLE. THE
CELLULAR STRUCTURE AND ENHANCED REFLECTIVITY SUGGEST THIS IS
ASSOCIATED WITH SLEET. BOTH THE HRRR AND RAP SUGGEST THIS WILL
CONTINUE TO DEVELOP AND MOVE EASTWARD WITH THE POTENTIAL FOR A
WINTRY MIX EVEN NORTH OF I-40 THIS MORNING INTO EARLY AFTERNOON.
THEREFORE...DECIDED TO EXPAND THE WINTER WEATHER ADVISORY FARTHER
NORTH.
WAVE NUMBER ONE WILL EXIT THE AREA LATE AFTERNOON INTO EARLY
EVENING. ATTENTION THEN TURNS TO SECOND WAVE OF PRECIPITATION THAT
IS ASSOCIATED WITH THE MAIN UPPER LEVEL LOW. A MORE WIDESPREAD
PRECIPITATION EVENT IS EXPECTED. PRECIPITATION WILL LIKELY DEVELOP
IN WESTERN NORTH TEXAS EARLY FRIDAY MORNING AND LIFT NORTHEASTWARD
THROUGH THE DAY FRIDAY. BECAUSE OF THE EARLY ONSET...THERE IS
CONCERN OF A SIGNIFICANT ICING EVENT ACROSS WESTERN NORTH TEXAS.
THE FORECAST ON FRIDAY WILL DEPEND ON THE EVOLUTION OF THE SFC 32F
WETBULB TEMPERATURE. LATEST GUIDANCE SUGGESTS THIS COULD BE VERY
CLOSE TO THE I-44 CORRIDOR BY FRIDAY AFTERNOON. OPTED FOR A MIX OF
RAIN/FREEZING RAIN ALONG I-44...WITH A FREEZING RAIN/SLEET MIX
NORTHWEST AND ALL RAIN SOUTHEAST.
A TRANSITION TO SNOW WILL OCCUR LATE FRIDAY INTO SATURDAY AS THE
UPPER LEVEL LOW PASSES THROUGH OKLAHOMA. BOTH THE PARALLEL GFS AND
ECMWF STILL SUGGEST THERE COULD BE ACCUMULATING SNOW IN NORTHERN
OKLAHOMA SATURDAY. THERE IS THE POTENTIAL THERE COULD BE ENOUGH
ACCUMULATING SNOW FOR HEADLINES. THE REST OF OKLAHOMA AND WESTERN
NORTH TEXAS COULD BE DRY SLOTTED SATURDAY.
AFTER COLLABORATION WITH SURROUNDING OFFICES...DECIDED TO HOLD
OFF ON ANY HEADLINES FOR FRIDAY AND SATURDAY. NEVERTHELESS...HEADLINES
WILL LIKELY BE REQUIRED FOR PARTS OF THE AREA FRIDAY INTO SATURDAY
FOR ACCUMULATING ICE AND/OR SNOW. STAY-TUNED!
BEYOND SATURDAY...A RATHER COLD DAY IS EXPECTED ON SUNDAY BEHIND THE
STORM SYSTEM. TEMPERATURES WILL SLOWLY MODERATE BEFORE ANOTHER COLD
FRONT APPROACHES THE REGION AROUND MID-WEEK. THE FORECAST IS DRY
BEYOND SATURDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 30 27 34 31 / 70 20 60 70
HOBART OK 28 24 33 29 / 80 20 50 60
WICHITA FALLS TX 30 29 34 32 / 90 60 80 70
GAGE OK 29 18 33 22 / 30 0 20 40
PONCA CITY OK 31 24 33 30 / 30 10 30 70
DURANT OK 32 32 36 36 / 90 50 80 80
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
OKZ021>048-050>052.
TX...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
11/10/11
AREA FORECAST DISCUSSION
NWS NORMAN OK
452 AM CST THU JAN 1 2015
.DISCUSSION...
WAVE NUMBER ONE OF PRECIPITATION IS ONGOING ACROSS SOUTHERN
OKLAHOMA AND WESTERN TEXAS THIS MORNING. RADAR TRENDS SHOW
ENHANCEMENT OF RADAR REFLECTIVITY IN THE TEXAS PANHANDLE. THE
CELLULAR STRUCTURE AND ENHANCED REFLECTIVITY SUGGEST THIS IS
ASSOCIATED WITH SLEET. BOTH THE HRRR AND RAP SUGGEST THIS WILL
CONTINUE TO DEVELOP AND MOVE EASTWARD WITH THE POTENTIAL FOR A
WINTRY MIX EVEN NORTH OF I-40 THIS MORNING INTO EARLY AFTERNOON.
THEREFORE...DECIDED TO EXPAND THE WINTER WEATHER ADVISORY FARTHER
NORTH.
WAVE NUMBER ONE WILL EXIT THE AREA LATE AFTERNOON INTO EARLY
EVENING. ATTENTION THEN TURNS TO SECOND WAVE OF PRECIPITATION THAT
IS ASSOCIATED WITH THE MAIN UPPER LEVEL LOW. A MORE WIDESPREAD
PRECIPITATION EVENT IS EXPECTED. PRECIPITATION WILL LIKELY DEVELOP
IN WESTERN NORTH TEXAS EARLY FRIDAY MORNING AND LIFT NORTHEASTWARD
THROUGH THE DAY FRIDAY. BECAUSE OF THE EARLY ONSET...THERE IS
CONCERN OF A SIGNIFICANT ICING EVENT ACROSS WESTERN NORTH TEXAS.
THE FORECAST ON FRIDAY WILL DEPEND ON THE EVOLUTION OF THE SFC 32F
WETBULB TEMPERATURE. LATEST GUIDANCE SUGGESTS THIS COULD BE VERY
CLOSE TO THE I-44 CORRIDOR BY FRIDAY AFTERNOON. OPTED FOR A MIX OF
RAIN/FREEZING RAIN ALONG I-44...WITH A FREEZING RAIN/SLEET MIX
NORTHWEST AND ALL RAIN SOUTHEAST.
A TRANSITION TO SNOW WILL OCCUR LATE FRIDAY INTO SATURDAY AS THE
UPPER LEVEL LOW PASSES THROUGH OKLAHOMA. BOTH THE PARALLEL GFS AND
ECMWF STILL SUGGEST THERE COULD BE ACCUMULATING SNOW IN NORTHERN
OKLAHOMA SATURDAY. THERE IS THE POTENTIAL THERE COULD BE ENOUGH
ACCUMULATING SNOW FOR HEADLINES. THE REST OF OKLAHOMA AND WESTERN
NORTH TEXAS COULD BE DRY SLOTTED SATURDAY.
AFTER COLLABORATION WITH SURROUNDING OFFICES...DECIDED TO HOLD
OFF ON ANY HEADLINES FOR FRIDAY AND SATURDAY. NEVERTHELESS...HEADLINES
WILL LIKELY BE REQUIRED FOR PARTS OF THE AREA FRIDAY INTO SATURDAY
FOR ACCUMULATING ICE AND/OR SNOW. STAY-TUNED!
BEYOND SATURDAY...A RATHER COLD DAY IS EXPECTED ON SUNDAY BEHIND THE
STORM SYSTEM. TEMPERATURES WILL SLOWLY MODERATE BEFORE ANOTHER COLD
FRONT APPROACHES THE REGION AROUND MID-WEEK. THE FORECAST IS DRY
BEYOND SATURDAY.
MAHALE
&&
.PRELIMINARY POINT TEMPS/POPS...
OKLAHOMA CITY OK 30 27 34 31 / 70 20 60 70
HOBART OK 28 24 33 29 / 80 20 50 60
WICHITA FALLS TX 30 29 34 32 / 90 60 80 70
GAGE OK 29 18 33 22 / 30 0 20 40
PONCA CITY OK 31 24 33 30 / 30 10 30 70
DURANT OK 32 32 36 36 / 90 50 80 80
&&
.OUN WATCHES/WARNINGS/ADVISORIES...
OK...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
OKZ021>048-050>052.
TX...WINTER WEATHER ADVISORY UNTIL 6 PM CST THIS EVENING FOR
TXZ083>090.
&&
$$
11/10
AREA FORECAST DISCUSSION...UPDATED
NWS MORRISTOWN TN
859 PM EST FRI JAN 2 2015
.DISCUSSION...
A WARM FRONT WILL CONTINUE TO LIFT NORTHWARD OVERNIGHT ACROSS THE
AREA. ISENTROPIC LIFT ALONG/AHEAD OF THIS FRONT WILL CONTINUE TO
GENERATE AREAS OF SHOWERS THIS EVENING AND OVERNIGHT...THOUGH THE
COVERAGE APPEARS TO BE LESS THAN THE MODELS ARE HAVE INDICATED.
THE HRRR STILL SHOWS AN AREA OF LIGHT TO MODERATE RAIN ACROSS
MIDDLE TN/NORTHERN AL FILLING IN AND LIFTING NORTHWARD WITH THE
FRONT BY AROUND 06Z BEFORE MOVING NORTH AND EAST OF THE REGION
AFTER 12Z. OTHER SOLUTIONS SHOW SOMETHING OF THIS NATURE AS
WELL...THOUGH HAVE USED CAUTIOUSLY GIVEN THEIR RECENT PERFORMANCE.
REGARDLESS...QPF WILL BE FAIRLY LIGHT AS COVERAGE WILL BE MORE
SCATTERED AT TIMES /PARTICULARLY OVER THE NORTH TO NORTHEAST
ZONES/. THUS...HAVE UNDERCUT POPS SOME...THOUGH STILL HAVE LIKELY
GOING IN MOST AREAS LATE TONIGHT AS DO THINK MOST LOCATIONS WILL AT
LEAST SEE SOME MEASURABLE PRECIP. THE NORTHWARD ADVANCING WARM
FRONT WILL ALSO LEAD TO A SOUTHEASTERLY WIND SHIFT AFTER MIDNIGHT
AND CAUSE TEMPERATURES TO SLOWLY RISING LATE TONIGHT FROM THE UPPER
30S TO LOWER 40S INTO THE MID TO EVEN UPPER 40S ACROSS MUCH OF THE
VALLEY BY EARLY MORNING. HAVE ADJUSTED THE ZONES AND TEMPERATURE
GRIDS TO REFLECT THIS AS WELL.
&&
.PRELIMINARY POINT TEMPS/POPS...
CHATTANOOGA AIRPORT, TN 44 58 53 55 / 70 60 100 50
KNOXVILLE MCGHEE TYSON AIRPORT, TN 42 57 51 56 / 70 70 100 60
OAK RIDGE, TN 42 57 51 55 / 70 70 100 50
TRI CITIES AIRPORT, TN 39 55 49 55 / 70 70 100 70
&&
.MRX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
TN...WIND ADVISORY FROM 10 AM SATURDAY TO 10 AM EST SUNDAY FOR BLOUNT
SMOKY MOUNTAINS-COCKE SMOKY MOUNTAINS-JOHNSON-SEVIER SMOKY
MOUNTAINS-SOUTHEAST CARTER-SOUTHEAST GREENE-SOUTHEAST
MONROE-UNICOI.
VA...NONE.
&&
$$
AMP
AREA FORECAST DISCUSSION
NWS NASHVILLE TN
214 PM CST THU JAN 1 2015
.DISCUSSION...WEAK HIGH PRESSURE CONTINUES TO COVER MIDDLE
TENNESSEE EARLY THIS AFTERNOON WITH A VFR OVERCAST STRATOCU DECK
KEEPING A LID ON TEMPERATURES. RADAR MOSAIC SHOWS A LARGE AREA OF
MAINLY LIGHT RAIN OVER NORTHERN MS AND EXTREME SW TN, BUT GIVEN
LARGE DEW POINT SPREADS STILL IN PLACE ACROSS THE MID STATE, RAIN
WILL BE SLOW TO ARRIVE HERE. HRRR DOES SHOW SOME DEVELOPMENT
DURING THE EVENING AND OVERNIGHT, WITH MOST OF THE ACTIVITY
REMAINING IN THE RELATIVELY WARM AIR OF SOUTHERN MIDDLE TENNESSEE.
SCATTERED ACTIVITY MAY DEVELOP ACROSS OUR NORTH BEFORE 12Z, AND UP
AGAINST THE KY STATE LINE THIS PRECIPITATION MAY START OFF AS A
RA/FZRA OR RA/IP MIXTURE, BUT ACCUMULATIONS ARE NOT EXPECTED. IN
THE MEANTIME, A DEVELOPING LOW TO OUR SW WILL COME RACING NE`WD
INTO THE OZARKS BY 12Z SATURDAY, BRINGING A WARM FRONT NORTHWARD
ACROSS MIDDLE TENNESSEE SO THAT TEMPERATURES SATURDAY MAY WARM
INTO THE 60`S OFF THE PLATEAU. MODEL SOUNDINGS DO SHOW SOME
ELEVATED INSTABILITY WITH THIS SYSTEM, SO WILL INCLUDE TS IN THE
FORECAST FOR SATURDAY AND SATURDAY NIGHT. CAN`T COMPLETELY RULE
OUT A THUNDERSTORM OR TWO PRIOR TO 12Z SATURDAY, BUT THE BEST
INSTABILITY WON`T OCCUR UNTIL DURING THE DAY, SO WILL LIMIT TS TO
DAY 3 ONLY. SPC ALSO HAS US IN A GENERAL THUNDERSTORM AREA ON DAY
3, WITH FROPA OCCURRING BETWEEN 00Z AND 12Z SUNDAY. THERE WILL
LIKELY BE SOME LEFTOVER RAIN ON SUNDAY, BUT THEN LOOK FOR DRY
WEATHER FROM SUNDAY NIGHT AT LEAST THROUGH THURSDAY. TEMPERATURES
NEXT WEEK WILL REMAIN COLDER THAN NORMAL AS WE NEVER DO REALLY
ESTABLISH ANY MEANINGFUL RETURN FLOW, SO IT`S GOING TO A COLD
WEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
NASHVILLE 34 41 40 62 / 50 80 100 90
CLARKSVILLE 31 38 37 63 / 40 70 100 100
CROSSVILLE 33 44 43 58 / 60 80 100 80
COLUMBIA 34 44 42 63 / 60 80 100 90
LAWRENCEBURG 33 45 44 64 / 60 90 100 90
WAVERLY 31 41 40 63 / 50 80 100 100
&&
.OHX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
ROSE
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
937 PM CST FRI JAN 2 2015
.UPDATE...
WARM FRONT REMAINS DRAPED ALONG THE COAST THIS EVENING FROM JUST
SOUTH OF PALACIOS TO GALVESTON TO BEAUMONT. ASIDE FROM A WIND
SHIFT THIS BOUNDARY IS ALSO APPARENT DUE TO THE 10 DEGREE
DIFFERENCE IN DEWPOINT BETWEEN ANGLETON AND GALVESTON. AREA OF
SHOWERS AND THUNDERSTORMS THAT PASSED THROUGH THE METRO AREA
EARLIER THIS EVENING CONTINUES TO PUSH OFF TO THE NORTH WITH ONLY
ISOLATED SHOWERS ACROSS THE SOUTHERN HALF OF OUR AREA AT THE
MOMENT. EXPECTING THIS SLIGHT BREAK IN THE ACTIVITY TO CONTINUE THIS
EVENING BEFORE COVERAGE PICKS UP AGAIN AFTER MIDNIGHT AS ANOTHER
WEAK DISTURBANCE APPROACHES THE REGION. PRECIP FORECAST LOOKS TO
BE IN GOOD SHAPE THIS EVENING AND ONLY CHANGES WERE SOME
ADJUSTMENTS TO TEMPERATURES AND DEWPOINTS TO REFLECT THE POSITION
OF THE WARM FRONT. 38
&&
.PREV DISCUSSION... /ISSUED 535 PM CST FRI JAN 2 2015/
AVIATION...
EXPECT MOSTLY IFR/LIFR CEILINGS AND VISIBILITIES ALONG WITH INCREASING
RA COVERAGE (AND SOME EMBEDDED SHRA/TSRA) ACROSS MUCH OF THE AREA THIS
EVENING AND OVERNIGHT. THERE COULD BE BRIEF PERIODS OF IMPROVED
CONDITIONS...BUT SIGNIFICANT IMPROVEMENT SHOULD NOT OCCUR UNTIL
LATE TOMORROW MORNING OUT WEST (CLL AREA) AND DURING THE AFTERNOON
HOURS TOWARD THE EAST AS THIS STORM SYSTEM MOVES OFF TO THE EAST. 42
PREV DISCUSSION... /ISSUED 345 PM CST FRI JAN 2 2015/
DISCUSSION...
A WARM FRONT OVER THE WATERS THIS MORNING HAS CONTINUED TO PUSH
NORTH AND HAS STARTED TO MOVE INLAND. THIS HAS ALLOWED DENSE SEA
FOG TO START TO MOVE INLAND AS WELL. DUE TO THIS HAVE EXTENDED
THE DENSE FOG ADVISORY UNTIL 6 AM TOMORROW MORNING AND HAVE ALSO
ADDED BRAZORIA... CHAMBERS...HARRIS... AND LIBERTY COUNTIES.
GFS... EURO... AND CANADIAN ARE ALL IN AGREEMENT WITH RAIN
CHANCES INCREASING STARTING AFTER MIDNIGHT TONIGHT INTO SATURDAY
MORNING. JET DYNAMICS AGAIN LOOK PRETTY GOOD WITH SOUTHEAST TEXAS
BEING IN A RRQ AND LFQ. FORECAST SOUNDINGS FOR THE GFS AND NAM
BOTH SHOW K INDEX VALUES AROUND 37 EARLY TOMORROW MORNING WITH
PWATS RANGING FROM 1.45 TO AROUND 1.60" (AROUND TO JUST UNDER +2
SD FOR THIS TIME OF YEAR). HIGH RES RAP HAS PERFORMED THE BEST
TODAY AND DOES NOT HAVE THAT IMPRESSIVE OF RAINFALL TOTALS FOR
TOMORROW MORNING WHILE THE NAM AND EURO HAVE AROUND 0.5" TO 1.50"
TOTAL FOR THE EVENT. THE STRONG UPPER LIFT IS HARD TO IGNORE AND
WILL GO WITH GFS/ EURO CONSENSUS ON RAINFALL TOTALS. THE HIGHEST
PRECIP TOTALS DUE APPEAR TO BE TOWARDS PORT AUTHOR THOUGH.
THE RAIN WILL MOVE OUT OF THE AREA SATURDAY WITH CLEARING SKIES
BEHIND IT. A STRONGER ARCTIC FRONT WILL THEN MOVE THROUGH THE AREA
SUNDAY MORNING. AHEAD OF THE FRONT SOME PATCHY FOG CAN BE EXPECTED
AS WINDS WEAKEN AND SKIES GO MOSTLY CLEAR. DEWPOINT DEPRESSION
FIELD FROM THE NAM SUPPORTS THIS. AT THE SAME TIME AN UPPER LEVEL
LOW WILL FORM OVER THE BAJA OF CALIFORNIA AND BEGIN TO RETROGRADE.
THE LOW WILL THEN MOVE UNDERNEATH A RIDGE OF HIGH PRESSURE FORMING
A REX BLOCK. THE CANADIAN AND EURO ARE AGAIN IN GOOD AGREEMENT
HERE. THE GFS CONTINUES TO TREND TOWARDS THE CANADIAN/ EURO
SOLUTION. THE EURO THEN BRINGS A MUCH STRONGER FRONT THROUGH THE
AREA EARLY WEDNESDAY. THE EURO AND CANADIAN BRING A 1050MB HIGH
DOWN WITH A 1043 HIGH SETTLING OVER SAN ANGELO THURSDAY MORNING.
THE EURO AND CANADIAN ALMOST LOOK IDENTICAL THURSDAY MORNING.
GIVEN THE CONSISTENCY BETWEEN THE EURO AND CANADIAN HAVE TRENDED TEMPS
DOWN SLIGHTLY THURSDAY MORNING. 23
MARINE...
A WARM FRONT CONTINUES TO ENCROACH ON THE COAST AND SFC DEW PTS OVER
THE WATER HAVE WARMED INTO THE LOWER 60S. WATER TEMPS ARE IN THE
UPPER 50S AND THIS HAS LED TO SOME SEA FOG. FEEL THE THREAT FOR FOG
WILL PERSIST FOR MUCH OF THE NIGHT AND WILL EXTEND THE DENSE FOG
ADVISORY OVER THE WATER THROUGH 12Z. SCATTERED SHRA/TSRA WILL BECOME
MORE NUMEROUS TONIGHT INTO SATURDAY AS A COLD FRONT APPROACHES THE
AREA. CONVECTION WILL PROVIDE SOME MIXING FROM TIME TO TIME BUT FEEL
THE OVERALL TREND WILL FAVOR LOW VSBY IN FOG. ALTHOUGH WINDS HAVE
DIMINISHED...FEEL TIDE LEVELS WILL REMAIN SLIGHTLY ELEVATED UNTIL A
PACIFIC COLD FRONT USHERS IN AN OFFSHORE FLOW ON SATURDAY MORNING. A
SECONDARY SURGE OF COLDER AIR ON SUNDAY WILL MOVE OVER THE WARMER
GULF WATERS AND THE STRONG CONTRAST IN TEMPS WILL PROVIDE FOR A
STRONG THERMAL GRADIENT AND OFFSHORE WIND SPEEDS WILL INCREASE. AN
SCA WILL LIKELY BE REQUIRED SUNDAY AND SUNDAY NIGHT. ANOTHER FRONT
WILL CROSS THE COASTAL WATERS ON WEDNESDAY WITH ANOTHER SCA LIKELY
AT THAT TIME. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 58 38 48 29 / 100 50 0 0 0
HOUSTON (IAH) 49 60 42 53 33 / 100 60 0 0 0
GALVESTON (GLS) 59 60 47 53 40 / 90 80 10 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...GALVESTON...HARRIS...LIBERTY.
GM...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...WATERS FROM HIGH ISLAND TO FREEPORT
OUT 20 NM.
&&
$$
DISCUSSION...38
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
535 PM CST FRI JAN 2 2015
.AVIATION...
EXPECT MOSTLY IFR/LIFR CEILINGS AND VISIBILITIES ALONG WITH INCREASING
RA COVERAGE (AND SOME EMBEDDED SHRA/TSRA) ACROSS MUCH OF THE AREA THIS
EVENING AND OVERNIGHT. THERE COULD BE BRIEF PERIODS OF IMPROVED
CONDITIONS...BUT SIGNIFICANT IMPROVEMENT SHOULD NOT OCCUR UNTIL
LATE TOMORROW MORNING OUT WEST (CLL AREA) AND DURING THE AFTERNOON
HOURS TOWARD THE EAST AS THIS STORM SYSTEM MOVES OFF TO THE EAST. 42
&&
.PREV DISCUSSION... /ISSUED 345 PM CST FRI JAN 2 2015/
DISCUSSION...
A WARM FRONT OVER THE WATERS THIS MORNING HAS CONTINUED TO PUSH
NORTH AND HAS STARTED TO MOVE INLAND. THIS HAS ALLOWED DENSE SEA
FOG TO START TO MOVE INLAND AS WELL. DUE TO THIS HAVE EXTENDED
THE DENSE FOG ADVISORY UNTIL 6 AM TOMORROW MORNING AND HAVE ALSO
ADDED BRAZORIA... CHAMBERS...HARRIS... AND LIBERTY COUNTIES.
GFS... EURO... AND CANADIAN ARE ALL IN AGREEMENT WITH RAIN
CHANCES INCREASING STARTING AFTER MIDNIGHT TONIGHT INTO SATURDAY
MORNING. JET DYNAMICS AGAIN LOOK PRETTY GOOD WITH SOUTHEAST TEXAS
BEING IN A RRQ AND LFQ. FORECAST SOUNDINGS FOR THE GFS AND NAM
BOTH SHOW K INDEX VALUES AROUND 37 EARLY TOMORROW MORNING WITH
PWATS RANGING FROM 1.45 TO AROUND 1.60" (AROUND TO JUST UNDER +2
SD FOR THIS TIME OF YEAR). HIGH RES RAP HAS PERFORMED THE BEST
TODAY AND DOES NOT HAVE THAT IMPRESSIVE OF RAINFALL TOTALS FOR
TOMORROW MORNING WHILE THE NAM AND EURO HAVE AROUND 0.5" TO 1.50"
TOTAL FOR THE EVENT. THE STRONG UPPER LIFT IS HARD TO IGNORE AND
WILL GO WITH GFS/ EURO CONSENSUS ON RAINFALL TOTALS. THE HIGHEST
PRECIP TOTALS DUE APPEAR TO BE TOWARDS PORT AUTHOR THOUGH.
THE RAIN WILL MOVE OUT OF THE AREA SATURDAY WITH CLEARING SKIES
BEHIND IT. A STRONGER ARCTIC FRONT WILL THEN MOVE THROUGH THE AREA
SUNDAY MORNING. AHEAD OF THE FRONT SOME PATCHY FOG CAN BE EXPECTED
AS WINDS WEAKEN AND SKIES GO MOSTLY CLEAR. DEWPOINT DEPRESSION
FIELD FROM THE NAM SUPPORTS THIS. AT THE SAME TIME AN UPPER LEVEL
LOW WILL FORM OVER THE BAJA OF CALIFORNIA AND BEGIN TO RETROGRADE.
THE LOW WILL THEN MOVE UNDERNEATH A RIDGE OF HIGH PRESSURE FORMING
A REX BLOCK. THE CANADIAN AND EURO ARE AGAIN IN GOOD AGREEMENT
HERE. THE GFS CONTINUES TO TREND TOWARDS THE CANADIAN/ EURO
SOLUTION. THE EURO THEN BRINGS A MUCH STRONGER FRONT THROUGH THE
AREA EARLY WEDNESDAY. THE EURO AND CANADIAN BRING A 1050MB HIGH
DOWN WITH A 1043 HIGH SETTLING OVER SAN ANGELO THURSDAY MORNING.
THE EURO AND CANADIAN ALMOST LOOK IDENTICAL THURSDAY MORNING.
GIVEN THE CONSISTENCY BETWEEN THE EURO AND CANADIAN HAVE TRENDED TEMPS
DOWN SLIGHTLY THURSDAY MORNING. 23
MARINE...
A WARM FRONT CONTINUES TO ENCROACH ON THE COAST AND SFC DEW PTS OVER
THE WATER HAVE WARMED INTO THE LOWER 60S. WATER TEMPS ARE IN THE
UPPER 50S AND THIS HAS LED TO SOME SEA FOG. FEEL THE THREAT FOR FOG
WILL PERSIST FOR MUCH OF THE NIGHT AND WILL EXTEND THE DENSE FOG
ADVISORY OVER THE WATER THROUGH 12Z. SCATTERED SHRA/TSRA WILL BECOME
MORE NUMEROUS TONIGHT INTO SATURDAY AS A COLD FRONT APPROACHES THE
AREA. CONVECTION WILL PROVIDE SOME MIXING FROM TIME TO TIME BUT FEEL
THE OVERALL TREND WILL FAVOR LOW VSBY IN FOG. ALTHOUGH WINDS HAVE
DIMINISHED...FEEL TIDE LEVELS WILL REMAIN SLIGHTLY ELEVATED UNTIL A
PACIFIC COLD FRONT USHERS IN AN OFFSHORE FLOW ON SATURDAY MORNING. A
SECONDARY SURGE OF COLDER AIR ON SUNDAY WILL MOVE OVER THE WARMER
GULF WATERS AND THE STRONG CONTRAST IN TEMPS WILL PROVIDE FOR A
STRONG THERMAL GRADIENT AND OFFSHORE WIND SPEEDS WILL INCREASE. AN
SCA WILL LIKELY BE REQUIRED SUNDAY AND SUNDAY NIGHT. ANOTHER FRONT
WILL CROSS THE COASTAL WATERS ON WEDNESDAY WITH ANOTHER SCA LIKELY
AT THAT TIME. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 44 58 38 48 29 / 100 50 0 0 0
HOUSTON (IAH) 51 60 42 53 33 / 100 60 0 0 0
GALVESTON (GLS) 57 60 47 53 40 / 90 80 10 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...GALVESTON...HARRIS...LIBERTY.
GM...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...WATERS FROM HIGH ISLAND TO FREEPORT
OUT 20 NM.
&&
$$
DISCUSSION...38
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1213 PM CST THU JAN 1 2015
.UPDATE...
SFC AND SHORT TERM HI RES MODEL ANALYSIS SHOWS THE 32 DEGREE LINE
SLOWLY CRAWLING NORTH OF OUR CWA BORDER BY EARLY THIS AFTERNOON.
SOME SFC OBS ARE STILL SHOWING AT OR JUST BELOW FREEZING FOR AREAS
ALONG THE BORDER AT 18Z. MOST RETURNS ON RADAR ARE EITHER NOT
REACHING THE SURFACE OR VERY LIGHT DRIZZLE AT THE MOMENT SO DID
NOT WANT TO EXTEND THE WARNING BEYOND 18Z. JUST CAPTURED THE MINOR
TRAVEL HAZARDS IN AN SPS FOR THE FIRST COUPLE HOURS OF THE AFTERNOON.
OTHERWISE...SOME SMALL ADJUSTMENTS TO THIS AFTERNOON PRECIP
CHANCES WERE MADE TO BETTER AGREE WITH NEIGHBORS AND BASED OFF
HRRR/WRF INPUT AND REST OF FORECAST PACKAGE LOOKS GOOD THROUGH
TONIGHT.
TB3
&&
.PREV DISCUSSION... /ISSUED 1148 AM CST THU JAN 1 2015/
AVIATION...
ISENTROPIC LIFT OF A MOIST AIRMASS OVER THE SHALLOW COLD AIRMASS
WILL MAINTAIN IFR/LIFR CIGS/VSBYS THIS AFTERNOON THROUGH FRIDAY.
PERIODS OF -RADZ AND BR ARE EXPECTED. N TO NE WINDS OF 10 KTS OR
LESS WILL PREVAIL...EXCEPT VRBL LESS THAN 5 KTS ALONG RIO GRANDE.
PREV DISCUSSION... /ISSUED 714 AM CST THU JAN 1 2015/
UPDATE...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
CIGS WILL CONTINUE TO LOWER THROUGHOUT THE DAY AS LIGHT PRECIPITATION
CONTINUES TO MOVE FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION.
MOST TAF SITES ARE EITHER CURRENTLY IFR OR WILL DROP INTO IFR
WITHIN THE NEXT COUPLE OF HOURS. ALL LIQUID PRECIPITATION IS
EXPECTED AT OUR TAF SITES AS TEMPERATURES REMAIN ABOVE FREEZING.
PREV DISCUSSION... /ISSUED 417 AM CST THU JAN 1 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
LIGHT FREEZING PRECIPITATION CONTINUES OVER THE ADVY AND WARNING
AREAS OF THE SRN EDWARDS PLATEAU...HILL COUNTRY AND BALCONES
ESCARPMENT. A CLUSTER OF WEAK THUNDERSTORMS CROSSED FROM NRN
MEXICO AND LOOKS TO BE PRODUCING A BRIGHT BAND OF WHAT IS PROBABLY
SNOW MELTING INTO RAIN AND POSSIBLY A PARTIAL MELT/REFREEZE TO
SLEET AND GRAUPEL. THIS CONVECTIVE AREA IS LOSING THE CELLULAR
STRUCTURE AND SHOULD CONTINUE TO WEAKEN AS IT LIFTS NE. THUS WILL
LEAVE OUT THE MENTION OF THUNDER AND LET NOWCASTS HANDLE WHAT
SHOULD BE A SHORT-LIVED EVENT.
THE DAYBREAK EMERGENCE OF CONVECTIVE SLEET BAND IS EXPECTED TO
TRACK RIGHT ALONG THE EASTERN PART OF THE BALCONES ESCARPMENT.
THUS AM HESITANT TO WARM MORNING TEMPERATURE FORECASTS TO MATCH
THE CURRENT TRENDS HOLDING ABOVE FREEZING. HI-RES MODELS HAVE KEPT
WITH THE CONVECTIVE BANDING AREA FORMING FARTHER NORTH...BUT THE
LATEST RUNS OF THE HRRR DEPICT THE ONGOING CONVECTIVE AREA WELL
AND SEND IT ACROSS THE AUSTIN METRO AREA AND NW PART OF THE SAN
ANTONIO METRO AREA THROUGH DAYBREAK. WHILE THIS CLUSTER OF
MODERATE PRECIPITATION COULD LOWER TEMPS TO FREEZING
BRIEFLY...EXPECT THE WEAKENING TREND TO ALLOW MOST AREAS IN THE
ADVISORY TO HOLD ONTO ABOVE FREEZING TEMPERATURES WITH MORE
ISOLATED FROZEN CONDITIONS POSSIBLE AT HIGHER ELEVATIONS. A
SECONDARY CONVECTIVE BAND REMAINS IN THE HRRR PICTURE WHICH SHOULD
POTENTIALLY ADD TO THE FREEZING RAIN/SLEET MIX OVER THE WARNING
AREA AT AROUND DAYBREAK. THUS THE ONGOING WINTER STORM WARNING AND
WINTER WEATHER ADVISORY AREA IS THUS CONSIDERED APPROPRIATE AND NO
WSW UPDATES ARE PLANNED.
THE CONSENSUS MODEL POPULATION OF THE TEMPERATURES IN THE GRIDDED
DATA SUGGESTED A QUICK WARM- UP TO ABOVE FREEZING...BUT WE FAVOR A
MORE GRADUAL RISE IN THE MORNING PERIOD WHERE ICING HAS OCCURRED.
BY NOON...MODEL SOUNDINGS SUGGEST THERE SHOULD BE AMPLE TIME FOR
THE WARMING TO HAVE OCCURRED...AS THE FRONTAL INVERSION SHOULD
CONTINUE TO BE MODIFIED BY FALLING RAIN AND DRIZZLE. A COLD RAIN
REMAINS IN THE PICTURE THROUGH FRIDAY. TEMPERATURES SHOULD BE
ALMOST FLAT FROM THIS AFTERNOON THROUGH LATE FRIDAY MORNING BEFORE
WARMING INTO THE 40S OVER MOST AREAS LATE FRIDAY. DESPITE THE HIGH
POPS BENEATH THE SOLID OVERRUNNING PATTERN...QPF AMOUNTS REMAIN
CONSERVATIVE AND GENERALLY BELOW 1/2 INCH.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE EASTWARD EJECTION OF A SLOW MOVING UPPER LOW BRINGS A SLIGHTLY
MORE CONVECTIVE ENVIRONMENT TO TX BY FRIDAY EVENING. THE INCREASED
POTENTIAL FOR THUNDER TRANSLATES TO SLIGHTLY HIGHER QPF AMOUNTS
WITH ANOTHER 1/2 INCH OF RAIN POSSIBLE IN THE FRIDAY NIGHT PERIOD
ALONE.
MODEL CONSENSUS REMAINS IN GOOD AGREEMENT TO BRING DECREASING
CLOUDS AND RAIN CHANCES BY MIDDAY SATURDAY AND PROBABLY THE
WARMEST TEMPS OF THE WEEK. THIS IS BECAUSE ANOTHER FRONT ARRIVES
BY SUNDAY MORNING. THE ECMWF TRENDED SHARPLY COLDER FROM THIS
FRONT WITH A MUCH ENHANCED POLAR TROUGH OVER THE EASTERN US. THE
GFS HAS ALSO TRENDED SLIGHTLY COLDER...SO A BLEND OF THESE TWO
MODELS LOOKS REASONABLE. AM HESITANT TO BUY INTO THE ECMWF BASED
GUIDANCE THAT PROJECTED MIDDLE TEENS OVER THE HILL COUNTRY MONDAY
MORNING. THE COLD PATTERN IS SHOWN BY BOTH THE GFS AND ECMWF
SOLUTIONS TO BE SHORT-LIVED WITH A PROGRESSIVE ZONAL PATTERN
PUSHING AN UPPER RIDGE OVER TX BY MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 38 43 40 59 / 80 90 80 80 30
AUSTIN BERGSTROM INTL AIRPORT 40 37 43 39 58 / 80 90 80 80 30
NEW BRAUNFELS MUNI AIRPORT 41 39 45 42 61 / 70 80 70 80 30
BURNET MUNI AIRPORT 38 35 40 37 57 / 90 90 80 80 20
DEL RIO INTL AIRPORT 41 41 49 41 61 / 40 50 40 50 -
GEORGETOWN MUNI AIRPORT 40 36 41 38 56 / 90 90 80 80 30
HONDO MUNI AIRPORT 41 39 47 40 62 / 50 60 50 60 20
SAN MARCOS MUNI AIRPORT 40 38 44 41 59 / 70 80 70 80 30
LA GRANGE - FAYETTE REGIONAL 43 41 47 44 59 / 70 70 80 80 40
SAN ANTONIO INTL AIRPORT 41 39 46 42 61 / 60 80 60 70 20
STINSON MUNI AIRPORT 42 40 46 42 62 / 60 70 60 70 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...03
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1148 AM CST THU JAN 1 2015
.AVIATION...
ISENTROPIC LIFT OF A MOIST AIRMASS OVER THE SHALLOW COLD AIRMASS
WILL MAINTAIN IFR/LIFR CIGS/VSBYS THIS AFTERNOON THROUGH FRIDAY.
PERIODS OF -RADZ AND BR ARE EXPECTED. N TO NE WINDS OF 10 KTS OR
LESS WILL PREVAIL...EXCEPT VRBL LESS THAN 5 KTS ALONG RIO GRANDE.
&&
.PREV DISCUSSION... /ISSUED 714 AM CST THU JAN 1 2015/
UPDATE...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
AVIATION...
CIGS WILL CONTINUE TO LOWER THROUGHOUT THE DAY AS LIGHT PRECIPITATION
CONTINUES TO MOVE FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION.
MOST TAF SITES ARE EITHER CURRENTLY IFR OR WILL DROP INTO IFR
WITHIN THE NEXT COUPLE OF HOURS. ALL LIQUID PRECIPITATION IS
EXPECTED AT OUR TAF SITES AS TEMPERATURES REMAIN ABOVE FREEZING.
PREV DISCUSSION... /ISSUED 417 AM CST THU JAN 1 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
LIGHT FREEZING PRECIPITATION CONTINUES OVER THE ADVY AND WARNING
AREAS OF THE SRN EDWARDS PLATEAU...HILL COUNTRY AND BALCONES
ESCARPMENT. A CLUSTER OF WEAK THUNDERSTORMS CROSSED FROM NRN
MEXICO AND LOOKS TO BE PRODUCING A BRIGHT BAND OF WHAT IS PROBABLY
SNOW MELTING INTO RAIN AND POSSIBLY A PARTIAL MELT/REFREEZE TO
SLEET AND GRAUPEL. THIS CONVECTIVE AREA IS LOSING THE CELLULAR
STRUCTURE AND SHOULD CONTINUE TO WEAKEN AS IT LIFTS NE. THUS WILL
LEAVE OUT THE MENTION OF THUNDER AND LET NOWCASTS HANDLE WHAT
SHOULD BE A SHORT-LIVED EVENT.
THE DAYBREAK EMERGENCE OF CONVECTIVE SLEET BAND IS EXPECTED TO
TRACK RIGHT ALONG THE EASTERN PART OF THE BALCONES ESCARPMENT.
THUS AM HESITANT TO WARM MORNING TEMPERATURE FORECASTS TO MATCH
THE CURRENT TRENDS HOLDING ABOVE FREEZING. HI-RES MODELS HAVE KEPT
WITH THE CONVECTIVE BANDING AREA FORMING FARTHER NORTH...BUT THE
LATEST RUNS OF THE HRRR DEPICT THE ONGOING CONVECTIVE AREA WELL
AND SEND IT ACROSS THE AUSTIN METRO AREA AND NW PART OF THE SAN
ANTONIO METRO AREA THROUGH DAYBREAK. WHILE THIS CLUSTER OF
MODERATE PRECIPITATION COULD LOWER TEMPS TO FREEZING
BRIEFLY...EXPECT THE WEAKENING TREND TO ALLOW MOST AREAS IN THE
ADVISORY TO HOLD ONTO ABOVE FREEZING TEMPERATURES WITH MORE
ISOLATED FROZEN CONDITIONS POSSIBLE AT HIGHER ELEVATIONS. A
SECONDARY CONVECTIVE BAND REMAINS IN THE HRRR PICTURE WHICH SHOULD
POTENTIALLY ADD TO THE FREEZING RAIN/SLEET MIX OVER THE WARNING
AREA AT AROUND DAYBREAK. THUS THE ONGOING WINTER STORM WARNING AND
WINTER WEATHER ADVISORY AREA IS THUS CONSIDERED APPROPRIATE AND NO
WSW UPDATES ARE PLANNED.
THE CONSENSUS MODEL POPULATION OF THE TEMPERATURES IN THE GRIDDED
DATA SUGGESTED A QUICK WARM- UP TO ABOVE FREEZING...BUT WE FAVOR A
MORE GRADUAL RISE IN THE MORNING PERIOD WHERE ICING HAS OCCURRED.
BY NOON...MODEL SOUNDINGS SUGGEST THERE SHOULD BE AMPLE TIME FOR
THE WARMING TO HAVE OCCURRED...AS THE FRONTAL INVERSION SHOULD
CONTINUE TO BE MODIFIED BY FALLING RAIN AND DRIZZLE. A COLD RAIN
REMAINS IN THE PICTURE THROUGH FRIDAY. TEMPERATURES SHOULD BE
ALMOST FLAT FROM THIS AFTERNOON THROUGH LATE FRIDAY MORNING BEFORE
WARMING INTO THE 40S OVER MOST AREAS LATE FRIDAY. DESPITE THE HIGH
POPS BENEATH THE SOLID OVERRUNNING PATTERN...QPF AMOUNTS REMAIN
CONSERVATIVE AND GENERALLY BELOW 1/2 INCH.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE EASTWARD EJECTION OF A SLOW MOVING UPPER LOW BRINGS A SLIGHTLY
MORE CONVECTIVE ENVIRONMENT TO TX BY FRIDAY EVENING. THE INCREASED
POTENTIAL FOR THUNDER TRANSLATES TO SLIGHTLY HIGHER QPF AMOUNTS
WITH ANOTHER 1/2 INCH OF RAIN POSSIBLE IN THE FRIDAY NIGHT PERIOD
ALONE.
MODEL CONSENSUS REMAINS IN GOOD AGREEMENT TO BRING DECREASING
CLOUDS AND RAIN CHANCES BY MIDDAY SATURDAY AND PROBABLY THE
WARMEST TEMPS OF THE WEEK. THIS IS BECAUSE ANOTHER FRONT ARRIVES
BY SUNDAY MORNING. THE ECMWF TRENDED SHARPLY COLDER FROM THIS
FRONT WITH A MUCH ENHANCED POLAR TROUGH OVER THE EASTERN US. THE
GFS HAS ALSO TRENDED SLIGHTLY COLDER...SO A BLEND OF THESE TWO
MODELS LOOKS REASONABLE. AM HESITANT TO BUY INTO THE ECMWF BASED
GUIDANCE THAT PROJECTED MIDDLE TEENS OVER THE HILL COUNTRY MONDAY
MORNING. THE COLD PATTERN IS SHOWN BY BOTH THE GFS AND ECMWF
SOLUTIONS TO BE SHORT-LIVED WITH A PROGRESSIVE ZONAL PATTERN
PUSHING AN UPPER RIDGE OVER TX BY MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 38 43 40 59 / 80 90 80 80 30
AUSTIN BERGSTROM INTL AIRPORT 40 37 43 39 58 / 80 90 80 80 30
NEW BRAUNFELS MUNI AIRPORT 41 39 45 42 61 / 70 80 70 80 30
BURNET MUNI AIRPORT 38 35 40 37 57 / 90 90 80 80 20
DEL RIO INTL AIRPORT 41 41 49 41 61 / 40 50 40 50 -
GEORGETOWN MUNI AIRPORT 40 36 41 38 56 / 90 90 80 80 30
HONDO MUNI AIRPORT 41 39 47 40 62 / 50 60 50 60 20
SAN MARCOS MUNI AIRPORT 40 38 44 41 59 / 70 80 70 80 30
LA GRANGE - FAYETTE REGIONAL 43 41 47 44 59 / 70 70 80 80 40
SAN ANTONIO INTL AIRPORT 41 39 46 42 61 / 60 80 60 70 20
STINSON MUNI AIRPORT 42 40 46 42 62 / 60 70 60 70 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER STORM WARNING UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...GILLESPIE...
KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...04
SYNOPTIC/GRIDS...03
PUBLIC SERVICE/DATA COLLECTION...12
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
714 AM CST THU JAN 1 2015
.UPDATE...
PLEASE SEE THE 12Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...
CIGS WILL CONTINUE TO LOWER THROUGHOUT THE DAY AS LIGHT PRECIPITATION
CONTINUES TO MOVE FROM SOUTHWEST TO NORTHEAST ACROSS THE REGION.
MOST TAF SITES ARE EITHER CURRENTLY IFR OR WILL DROP INTO IFR
WITHIN THE NEXT COUPLE OF HOURS. ALL LIQUID PRECIPITATION IS
EXPECTED AT OUR TAF SITES AS TEMPERATURES REMAIN ABOVE FREEZING.
&&
.PREV DISCUSSION... /ISSUED 417 AM CST THU JAN 1 2015/
SHORT TERM (TODAY THROUGH FRIDAY)...
LIGHT FREEZING PRECIPITATION CONTINUES OVER THE ADVY AND WARNING
AREAS OF THE SRN EDWARDS PLATEAU...HILL COUNTRY AND BALCONES
ESCARPMENT. A CLUSTER OF WEAK THUNDERSTORMS CROSSED FROM NRN
MEXICO AND LOOKS TO BE PRODUCING A BRIGHT BAND OF WHAT IS PROBABLY
SNOW MELTING INTO RAIN AND POSSIBLY A PARTIAL MELT/REFREEZE TO
SLEET AND GRAUPEL. THIS CONVECTIVE AREA IS LOSING THE CELLULAR
STRUCTURE AND SHOULD CONTINUE TO WEAKEN AS IT LIFTS NE. THUS WILL
LEAVE OUT THE MENTION OF THUNDER AND LET NOWCASTS HANDLE WHAT
SHOULD BE A SHORT-LIVED EVENT.
THE DAYBREAK EMERGENCE OF CONVECTIVE SLEET BAND IS EXPECTED TO
TRACK RIGHT ALONG THE EASTERN PART OF THE BALCONES ESCARPMENT.
THUS AM HESITANT TO WARM MORNING TEMPERATURE FORECASTS TO MATCH
THE CURRENT TRENDS HOLDING ABOVE FREEZING. HI-RES MODELS HAVE KEPT
WITH THE CONVECTIVE BANDING AREA FORMING FARTHER NORTH...BUT THE
LATEST RUNS OF THE HRRR DEPICT THE ONGOING CONVECTIVE AREA WELL
AND SEND IT ACROSS THE AUSTIN METRO AREA AND NW PART OF THE SAN
ANTONIO METRO AREA THROUGH DAYBREAK. WHILE THIS CLUSTER OF
MODERATE PRECIPITATION COULD LOWER TEMPS TO FREEZING
BRIEFLY...EXPECT THE WEAKENING TREND TO ALLOW MOST AREAS IN THE
ADVISORY TO HOLD ONTO ABOVE FREEZING TEMPERATURES WITH MORE
ISOLATED FROZEN CONDITIONS POSSIBLE AT HIGHER ELEVATIONS. A
SECONDARY CONVECTIVE BAND REMAINS IN THE HRRR PICTURE WHICH SHOULD
POTENTIALLY ADD TO THE FREEZING RAIN/SLEET MIX OVER THE WARNING
AREA AT AROUND DAYBREAK. THUS THE ONGOING WINTER STORM WARNING AND
WINTER WEATHER ADVISORY AREA IS THUS CONSIDERED APPROPRIATE AND NO
WSW UPDATES ARE PLANNED.
THE CONSENSUS MODEL POPULATION OF THE TEMPERATURES IN THE GRIDDED
DATA SUGGESTED A QUICK WARM- UP TO ABOVE FREEZING...BUT WE FAVOR A
MORE GRADUAL RISE IN THE MORNING PERIOD WHERE ICING HAS OCCURRED.
BY NOON...MODEL SOUNDINGS SUGGEST THERE SHOULD BE AMPLE TIME FOR
THE WARMING TO HAVE OCCURRED...AS THE FRONTAL INVERSION SHOULD
CONTINUE TO BE MODIFIED BY FALLING RAIN AND DRIZZLE. A COLD RAIN
REMAINS IN THE PICTURE THROUGH FRIDAY. TEMPERATURES SHOULD BE
ALMOST FLAT FROM THIS AFTERNOON THROUGH LATE FRIDAY MORNING BEFORE
WARMING INTO THE 40S OVER MOST AREAS LATE FRIDAY. DESPITE THE HIGH
POPS BENEATH THE SOLID OVERRUNNING PATTERN...QPF AMOUNTS REMAIN
CONSERVATIVE AND GENERALLY BELOW 1/2 INCH.
LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE EASTWARD EJECTION OF A SLOW MOVING UPPER LOW BRINGS A SLIGHTLY
MORE CONVECTIVE ENVIRONMENT TO TX BY FRIDAY EVENING. THE INCREASED
POTENTIAL FOR THUNDER TRANSLATES TO SLIGHTLY HIGHER QPF AMOUNTS
WITH ANOTHER 1/2 INCH OF RAIN POSSIBLE IN THE FRIDAY NIGHT PERIOD
ALONE.
MODEL CONSENSUS REMAINS IN GOOD AGREEMENT TO BRING DECREASING
CLOUDS AND RAIN CHANCES BY MIDDAY SATURDAY AND PROBABLY THE
WARMEST TEMPS OF THE WEEK. THIS IS BECAUSE ANOTHER FRONT ARRIVES
BY SUNDAY MORNING. THE ECMWF TRENDED SHARPLY COLDER FROM THIS
FRONT WITH A MUCH ENHANCED POLAR TROUGH OVER THE EASTERN US. THE
GFS HAS ALSO TRENDED SLIGHTLY COLDER...SO A BLEND OF THESE TWO
MODELS LOOKS REASONABLE. AM HESITANT TO BUY INTO THE ECMWF BASED
GUIDANCE THAT PROJECTED MIDDLE TEENS OVER THE HILL COUNTRY MONDAY
MORNING. THE COLD PATTERN IS SHOWN BY BOTH THE GFS AND ECMWF
SOLUTIONS TO BE SHORT-LIVED WITH A PROGRESSIVE ZONAL PATTERN
PUSHING AN UPPER RIDGE OVER TX BY MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 38 43 40 59 / 80 90 80 80 30
AUSTIN BERGSTROM INTL AIRPORT 40 37 43 39 58 / 80 90 80 80 30
NEW BRAUNFELS MUNI AIRPORT 41 39 45 42 61 / 70 80 70 80 30
BURNET MUNI AIRPORT 38 35 40 37 57 / 90 90 80 80 20
DEL RIO INTL AIRPORT 41 41 49 41 61 / 40 50 40 50 -
GEORGETOWN MUNI AIRPORT 40 36 41 38 56 / 90 90 80 80 30
HONDO MUNI AIRPORT 41 39 47 40 62 / 50 60 50 60 20
SAN MARCOS MUNI AIRPORT 40 38 44 41 59 / 70 80 70 80 30
LA GRANGE - FAYETTE REGIONAL 43 41 47 44 59 / 70 70 80 80 40
SAN ANTONIO INTL AIRPORT 41 39 46 42 61 / 60 80 60 70 20
STINSON MUNI AIRPORT 42 40 46 42 62 / 60 70 60 70 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BEXAR...COMAL...HAYS...KINNEY...MEDINA...TRAVIS...
UVALDE...WILLIAMSON.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...GILLESPIE...
KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...18
SYNOPTIC/GRIDS...24
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
417 AM CST THU JAN 1 2015
.SHORT TERM (TODAY THROUGH FRIDAY)...
LIGHT FREEZING PRECIPITATION CONTINUES OVER THE ADVY AND WARNING
AREAS OF THE SRN EDWARDS PLATEAU...HILL COUNTRY AND BALCONES
ESCARPMENT. A CLUSTER OF WEAK THUNDERSTORMS CROSSED FROM NRN
MEXICO AND LOOKS TO BE PRODUCING A BRIGHT BAND OF WHAT IS PROBABLY
SNOW MELTING INTO RAIN AND POSSIBLY A PARTIAL MELT/REFREEZE TO
SLEET AND GRAUPEL. THIS CONVECTIVE AREA IS LOSING THE CELLULAR
STRUCTURE AND SHOULD CONTINUE TO WEAKEN AS IT LIFTS NE. THUS WILL
LEAVE OUT THE MENTION OF THUNDER AND LET NOWCASTS HANDLE WHAT
SHOULD BE A SHORT-LIVED EVENT.
THE DAYBREAK EMERGENCE OF CONVECTIVE SLEET BAND IS EXPECTED TO
TRACK RIGHT ALONG THE EASTERN PART OF THE BALCONES ESCARPMENT.
THUS AM HESITANT TO WARM MORNING TEMPERATURE FORECASTS TO MATCH
THE CURRENT TRENDS HOLDING ABOVE FREEZING. HI-RES MODELS HAVE KEPT
WITH THE CONVECTIVE BANDING AREA FORMING FARTHER NORTH...BUT THE
LATEST RUNS OF THE HRRR DEPICT THE ONGOING CONVECTIVE AREA WELL
AND SEND IT ACROSS THE AUSTIN METRO AREA AND NW PART OF THE SAN
ANTONIO METRO AREA THROUGH DAYBREAK. WHILE THIS CLUSTER OF
MODERATE PRECIPITATION COULD LOWER TEMPS TO FREEZING
BRIEFLY...EXPECT THE WEAKENING TREND TO ALLOW MOST AREAS IN THE
ADVISORY TO HOLD ONTO ABOVE FREEZING TEMPERATURES WITH MORE
ISOLATED FROZEN CONDITIONS POSSIBLE AT HIGHER ELEVATIONS. A
SECONDARY CONVECTIVE BAND REMAINS IN THE HRRR PICTURE WHICH SHOULD
POTENTIALLY ADD TO THE FREEZING RAIN/SLEET MIX OVER THE WARNING
AREA AT AROUND DAYBREAK. THUS THE ONGOING WINTER STORM WARNING AND
WINTER WEATHER ADVISORY AREA IS THUS CONSIDERED APPROPRIATE AND NO
WSW UPDATES ARE PLANNED.
THE CONSENSUS MODEL POPULATION OF THE TEMPERATURES IN THE GRIDDED
DATA SUGGESTED A QUICK WARM- UP TO ABOVE FREEZING...BUT WE FAVOR A
MORE GRADUAL RISE IN THE MORNING PERIOD WHERE ICING HAS OCCURRED.
BY NOON...MODEL SOUNDINGS SUGGEST THERE SHOULD BE AMPLE TIME FOR
THE WARMING TO HAVE OCCURRED...AS THE FRONTAL INVERSION SHOULD
CONTINUE TO BE MODIFIED BY FALLING RAIN AND DRIZZLE. A COLD RAIN
REMAINS IN THE PICTURE THROUGH FRIDAY. TEMPERATURES SHOULD BE
ALMOST FLAT FROM THIS AFTERNOON THROUGH LATE FRIDAY MORNING BEFORE
WARMING INTO THE 40S OVER MOST AREAS LATE FRIDAY. DESPITE THE HIGH
POPS BENEATH THE SOLID OVERRUNNING PATTERN...QPF AMOUNTS REMAIN
CONSERVATIVE AND GENERALLY BELOW 1/2 INCH.
&&
.LONG TERM (FRIDAY NIGHT THROUGH WEDNESDAY)...
THE EASTWARD EJECTION OF A SLOW MOVING UPPER LOW BRINGS A SLIGHTLY
MORE CONVECTIVE ENVIRONMENT TO TX BY FRIDAY EVENING. THE INCREASED
POTENTIAL FOR THUNDER TRANSLATES TO SLIGHTLY HIGHER QPF AMOUNTS
WITH ANOTHER 1/2 INCH OF RAIN POSSIBLE IN THE FRIDAY NIGHT PERIOD
ALONE.
MODEL CONSENSUS REMAINS IN GOOD AGREEMENT TO BRING DECREASING
CLOUDS AND RAIN CHANCES BY MIDDAY SATURDAY AND PROBABLY THE
WARMEST TEMPS OF THE WEEK. THIS IS BECAUSE ANOTHER FRONT ARRIVES
BY SUNDAY MORNING. THE ECMWF TRENDED SHARPLY COLDER FROM THIS
FRONT WITH A MUCH ENHANCED POLAR TROUGH OVER THE EASTERN US. THE
GFS HAS ALSO TRENDED SLIGHTLY COLDER...SO A BLEND OF THESE TWO
MODELS LOOKS REASONABLE. AM HESITANT TO BUY INTO THE ECMWF BASED
GUIDANCE THAT PROJECTED MIDDLE TEENS OVER THE HILL COUNTRY MONDAY
MORNING. THE COLD PATTERN IS SHOWN BY BOTH THE GFS AND ECMWF
SOLUTIONS TO BE SHORT-LIVED WITH A PROGRESSIVE ZONAL PATTERN
PUSHING AN UPPER RIDGE OVER TX BY MIDWEEK.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 38 43 40 59 / 80 90 80 80 30
AUSTIN BERGSTROM INTL AIRPORT 40 37 43 39 58 / 80 90 80 80 30
NEW BRAUNFELS MUNI AIRPORT 41 39 45 42 61 / 70 80 70 80 30
BURNET MUNI AIRPORT 38 35 40 37 57 / 90 90 80 80 20
DEL RIO INTL AIRPORT 41 41 49 41 61 / 40 50 40 50 -
GEORGETOWN MUNI AIRPORT 40 36 41 38 56 / 90 90 80 80 30
HONDO MUNI AIRPORT 41 39 47 40 62 / 50 60 50 60 20
SAN MARCOS MUNI AIRPORT 40 38 44 41 59 / 70 80 70 80 30
LA GRANGE - FAYETTE REGIONAL 43 41 47 44 59 / 70 70 80 80 40
SAN ANTONIO INTL AIRPORT 41 39 46 42 61 / 60 80 60 70 20
STINSON MUNI AIRPORT 42 40 46 42 62 / 60 70 60 70 20
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BEXAR...COMAL...HAYS...KINNEY...MEDINA...TRAVIS...
UVALDE...WILLIAMSON.
WINTER STORM WARNING UNTIL NOON CST TODAY FOR THE FOLLOWING
COUNTIES: BANDERA...BLANCO...BURNET...EDWARDS...GILLESPIE...
KENDALL...KERR...LLANO...REAL...VAL VERDE.
&&
$$
MESOSCALE/AVIATION...24
SYNOPTIC/GRIDS...18
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
903 PM EST FRI JAN 2 2015
.SYNOPSIS...
HIGH PRESSURE SHIFTS FROM THE OHIO VALLEY INTO THE MID ATLANTIC
AND NORTHEAST THROUGH THE WEEKEND. A STORM SYSTEM MOVING ACROSS
THE SOUTHERN PLAINS SENDS A WARM FRONT NORTHWARD INTO THE REGION
BY SATURDAY WITH MAINLY RAIN EXPECTED. A COLD FRONT FOLLOWS FOR
LATER SUNDAY INTO SUNDAY NIGHT FOLLOWED BY GUSTY NORTHWEST WINDS
AND A SURGE OF COLDER AIR FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 855 PM EST FRIDAY...
SURFACE HIGH PRESSURE WAS CENTERED OVER SOUTHERN MARYLAND.
PREVAILING 85H WINDS WERE STILL FROM THE WEST BUT SPEEDS WERE
DIMINISHING AND WERE LESS THAN 25 KNOTS ON THE 00Z BLACKSBURG SOUNDING.
LOW LEVEL WINDS WILL START TO BACK TO SOUTHWEST THEN SOUTH
ORIENTATION AS AS UPPER LOW MOVES EAST OUT OF THE SOUTHERN
PLAINS...AND A SURFACE LOW BEGINS TO FORM NEAR THE MISSISSIPPI
DELTA. A WEDGE PATTERN WILL SET UP OVER THE EASTERN PARTS OF THE
REGION THAT WILL INTENSIFY HEADING INTO SATURDAY.
HAVE ADJUSTED THE ARRIVAL TIME OF THE PRECIPITATION. LOCAL WRF
SUGGESTED RAIN AS EARLY AS 10PM...BUT HRRR AND RAP GUIDANCE HELD
OFF A BULK OF THE PRECIPITATION UNTIL MIDNIGHT. A FEW POCKETS OF
SLEET ARE POSSIBLE ON THE LEADING EDGE OF THE PRECIPITATION...
GENERALLY ALONG AND NORTH OF I-64 IN WV AND VA. A LARGE EXPANSE OF
RAIN WILL SPREAD ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST
BEFORE SUNRISE.
MILDER AIR IS EXPECTED TO MOVE INTO THE REGION OVERNIGHT...THUS
ALLOWING FOR THE OVERNIGHT LOW TEMPERATURES IN MOST AREAS TO OCCUR
DURING THE EVENING...WITH TEMPERATURES STEADY OR SLOWLY RISING
THROUGH SUNRISE SATURDAY. LOWS TONIGHT WILL RANGE FROM THE LOW TO
MID 30S ACROSS THE MOUNTAINS WITH A MIX OF 30S ACROSS THE
PIEDMONT. THE FOOTHILLS OF NC WILL SEE LOWS AROUND 40. HIGHS ON
SATURDAY WILL RANGE FROM THE UPPER 30S UNDER THE HEART OF THE LEE
SIDE WEDGE...TO THE LOWER 50S OUTSIDE OF THE WEDGE IN AREAS
BETWEEN BLUEFIELD WV AND RICHLANDS VA.
GUSTY CONDITIONS ARE ALSO EXPECTED TO DEVELOP OVERNIGHT AT THE
RIDGE TOPS...WITH THE HIGHEST ELEVATIONS EXPERIENCING GUSTS OF 25
TO 30 MPH BY DAYBREAK. DURING THE DAY SATURDAY...GUSTS WILL
INCREASE TO 30 TO 35 MPH AT THE HIGHEST ELEVATIONS.
ON SATURDAY...THE BULK OF THE PRECIPITATION WILL BECOME FOCUSED
NORTH OF THE AREA ALONG THE FORCING OF A DEVELOPING WARM FRONT NEAR
THE MASON-DIXON LINE. MOST OF OUR PRECIPITATION WILL BE ALONG THE
CREST OF THE BLUE RIDGE SOUTH OF ROANOKE WITH PATCHY LIGHT RAIN
ELSEWHERE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM EST FRIDAY...
DURING THE OVERNIGHT HOURS SATURDAY NIGHT/SUNDAY
MORNING...GFS/ECMWF/SREF ALL STRENGTHEN THE 850MB JET IN EXCESS OF
50+ KTS IN ADVANCE OF A STRONG COLD FRONT THAT WILL REMAIN WEST OF
OUR FORECAST AREA THROUGH 12Z SUNDAY. THIS SHOULD HELP BREAK THE
WEDGE...SURGE DEW POINTS UP...AND ALLOW TEMPS TO CLIMB DURING THE
OVERNIGHT HOURS.
AT THE BEGINNING OF THE SATURDAY NIGHT PERIOD WE MAY SEE A LULL IN
THE PRECIP AS WE FALL UNDER A WEAK DRY SLOT...BUT LATER IN THE NIGHT
STRONG THETA-E ADVECTION SHOULD HELP GENERATE PRECIP...ESPECIALLY IN
THE FAR WEST CLOSER TO THE BEST LOW LEVEL FORCING.
GFS/ECMWF/NAM/SREF ARE ALL IN GOOD AGREEMENT THAT THE COLD FRONT
EXITS OUR FORECAST AREA BY 00Z MONDAY (7 PM SUNDAY).
GFS MOS MOS FORECAST NEAR RECORD/RECORD HIGHS SUNDAY IN THE EAST
WHERE 850MB TEMPS WILL BE AOA +12C. WILL CONTINUE THE TREND OF
INCREASING HIGHS ON SUNDAY...BUT NOT TO THAT EXTREME.
WHILE INSTABILITY PARAMETERS ARE NOT AS IMPRESSIVE AS
YESTERDAY...STRONG FORCING WITH THE FRONT COULD STILL GENERATE A FEW
RUMBLES OF THUNDER IN THE FAR SOUTHEAST WHERE SPC HAS OUTLOOKED FOR
GENERAL THUNDER.
BEHIND THE FRONT...STRONG PRESSURE RISES AND 850MB WEST WINDS
GREATER THAN 50 KTS WILL BRING STRONG WINDS...ESPECIALLY TO THE
MOUNTAINS LATE SUNDAY THROUGH SUNDAY NIGHT. A LOCAL GFS MOS STUDY
SUGGESTS FORECAST WINDS AT ROA AND TNB WILL BE HIGH ENOUGH TO EXCEED
ADVISORY LEVELS. SIGNIFICANTLY INCREASED WINDS DURING THIS TIME
FRAME AND WILL BEEF UP WORDING IN THE HWO FOR THIS THREAT.
DESPITE THINNING LOW LEVEL MOISTURE SUNDAY NIGHT AND EARLY
MONDAY...COLD AIR ADVECTION SHOULD KEEP LIGHT SNOW/FLURRIES FOR THE
WESTERN SLOPES INTO MONDAY MORNING. ACCUMULATIONS IN WESTERN
GREENBRIER SHOULD BE 1" OR LESS WITH NO GREAT LAKES CONNECTION.
BLUSTERY AND COLD CONDITIONS ARE EXPECTED ON MONDAY WITH WINDS
GRADUALLY DIMINISHING AS A LARGE AREA OF HIGH PRESSURE MOVES INTO
THE EASTERN OHIO VALLEY BY 00Z TUESDAY (7 PM MONDAY). WENT BELOW
GUIDANCE VALUES FOR HIGHS ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 3 PM EST FRIDAY...
VERY COLD AND WINDY FOR MOST OF THE UPCOMING WEEK.
MODELS ARE CONSISTENT IN PROJECTING THE EXTENDED PERIOD TO BE
DOMINATED BY A PERSISTENT CUTOFF LOW DEVELOPING OVER THE SOUTHWEST
US/BAJA PENINSULA TOPPED BY A DECENT AMPLITUDE RIDGE OVER THE
PACIFIC NW...WITH NORTHERN AND SOUTHERN STREAM ENERGY COMBINING TO
KEEP THE EASTERN US UNDER THE INFLUENCE OF A BROAD TROF. AS WE HEAD
TOWARD THE END OF NEXT WEEK...THE PATTERN WILL BE SHIFTING MORE TO A
ZONAL FLOW REGIME WITH THE CUTOFF LOW OVER THE SOUTHWEST US OPENING
UP WHILE THE EASTERN TROF LIFTS NORTHEASTWARD.
TUESDAY WILL START OFF WITH HIGH PRESSURE PUSHING OFF TO OUR EAST AS
AN ALBERTA CLIPPER ZIPS BY WELL TO OUR NORTH AND SWINGS A COLD FRONT
THROUGH LATE ON TUESDAY. THIS COLD FRONT WILL OPEN THE FREEZER DOOR
AND ALLOW ARCTIC AIR TO POUR INTO THE REGION ON STRONG NORTHWEST
WINDS STARTING TUESDAY NIGHT...SETTING THE STAGE FOR VERY COLD
TEMPERATURES FOR THE MIDDLE OF THE WORKWEEK. TEMPERATURES WILL BE
PUSHING 20 DEGREES BELOW NORMAL ON BOTH WEDNESDAY AND THURSDAY...AND
THE HOWLING NORTHWEST WIND WILL BRING WIND CHILL VALUES INTO THE
SINGLE DIGITS TO BELOW ZERO FROM WEDNESDAY MORNING THROUGH FRIDAY
MORNING WITH THE HARSHEST CONDITIONS EXPECTED WEST OF THE BLUE
RIDGE. CONDITIONS WILL MODERATE...THOUGH REMAIN BELOW NORMAL...BY
FRIDAY AND INTO THE WEEKEND AS THE CORE OF THE COLD AIR PUSHES
THROUGH.
MOISTURE WILL BE QUITE LIMITED WITH THE COLD AIR BUT IT WILL NOT
TAKE MUCH TO SQUEEZE OUT SOME UPSLOPE NORTHWEST FLOW SNOW SHOWERS
WEST OF THE BLUE RIDGE. CURRENT INDICATIONS ARE THAT THE FAR WESTERN
SLOPES MAY SEE ENOUGH PERSISTENT SNOW SHOWERS FOR SOME LIGHT AND DRY
WINDBLOWN ACCUMULATIONS TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /02Z SATURDAY THROUGH WEDNESDAY/...
AS OF 650 PM EST FRIDAY...
SMALL PATCH OF IFR CEILINGS AND MVFR FOG IN FAR SOUTHWEST VIRGINIA
THIS EVENING. LOWER CEILINGS MAY OCCASIONALLY DRIFT INTO KBLF.
REST OF THE FORECAST AREA WAS CLOUDY WITH GENERALLY 4000-6000FT
CEILINGS.
HAVE ADJUSTED THE ARRIVAL TIME OF THE RAIN FOR TONIGHT UNTIL AFTER
MIDNIGHT...BASED ON THE LATEST RADAR TRENDS AND THE 18Z RAP
GUIDANCE. SURFACE BASED WEDGE DEVELOPS LATE TONIGHT ON THE
EASTERN SLOPES OF THE APPALACHIANS. ABOVE THIS WEDGE...LOW LEVEL
WINDS SHIFT TO THE SOUTH WITH WIND SPEEDS INCREASING TO AROUND 45
KNOTS BY 12Z/7AM OVER THE MOUNTAINS. THIS INCREASINGLY STRONG
SOUTH WIND WILL RESULT IN STRONG ISENTROPIC LIFT AND WIDESPREAD
LIGHT RAIN. HAVE ADDED LLWS IN FOR KROA AND KBCB FOR LATE TONIGHT
INTO SATURDAY MORNING. HIGH CONFIDENCE THAT CEILINGS WILL LOWER TO
IFR AS THE RAIN BEGINS AND VISIBILITIES WILL HOLD IN THE MVFR
RANGE. A MAJORITY OF THE RAIN WILL MOVE NORTH OUT OF THE REGION BY
SATURDAY AFTERNOON. HOWEVER...CEILINGS AND VISIBILITIES WILL BE
VERY SLOW TO IMPROVE. ONLY MODERATE CONFIDENCE THAT CEILINGS WILL
LIFT BACK ABOVE 1500FT.
STRONG COLD FRONTAL PASSAGE ON SUNDAY. VERY GUSTY WINDS BEHIND
THE FRONT. CONDITIONS IMPROVE TO VFR ACROSS ALL BUT THE FAR
WESTERN PARTS OF THE REGION.
MONDAY INTO TUESDAY...PRIMARILY VFR CONDITIONS ACROSS THE AREA
WITH THE RETURN OF SURFACE HIGH PRESSURE...BUT TIGHT GRADIENT AT
850 MB WILL HELP MAINTAIN GUSTY CONDITIONS.
CLIPPER SYSTEM PASSES MAINLY NORTH OF THE REGION TUESDAY
AFTERNOON. EXPECT REINFORCING PUNCH OF COLDER AIR AND CONTINUED
STRONG NORTHWEST WINDS THROUGH THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...AMS/DS
SHORT TERM...PH
LONG TERM...MBS
AVIATION...AMS/DS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
906 PM CST FRI JAN 2 2015
.UPDATE...OVERNIGHT
ISSUED AT 906 PM CST FRI JAN 2 2015
STARTING TO GET REPORTS OF FLURRIES ACROSS PARTS OF IOWA. TALKED
WITH THE DES MOINES OFFICE AND THEY SAID THAT THEY WERE GETTING
FLURRIES AT BOTH THE OFFICE AND AIRPORT. THIS IS LINKED TO THE 800
TO 500 MB FRONTOGENESIS. BOTH THE LATEST RAP AND 03.00Z RAP SHOW
THAT THIS FORCING WILL MOVE IN AND INCREASE IN INTENSITY BETWEEN
BETWEEN 02.04Z AND 02.06Z ACROSS SOUTHWEST WISCONSIN AND NORTHERN
IOWA. PLAN ON MOVING THE SNOW CHANCES INTO THE AREA EARLIER AREA.
SOUNDINGS CONTINUE TO SUGGEST SNOW EARLY...AND THEN POSSIBLY
TAPERING OFF TO FREEZING DRIZZLE AS IT ENDS. THINKING THAT WE HAVE
TOO MUCH PRECIPITATION CHANCES FOR SATURDAY MORNING...SO MAY HAVE
TO ADJUST THEM LOWER OR REMOVE THEM...BUT WILL WAIT A FEW MORE
HOURS BEFORE DOING THAT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 321 PM CST FRI JAN 2 2015
THE MAIN CONCERNS ARE WITH THE PRECIPITATION CHANCES THROUGH THE
PERIOD.
WATER VAPOR SATELLITE THIS AFTERNOON SHOWING AN UPPER LEVEL LOW
OVER NEBRASKA. THE 02.12Z MODELS ALL IN GOOD AGREEMENT IN SHOWING
THIS LOW BECOMING AN OPEN WAVE AND LIFTING ACROSS THE REGION LATE
TONIGHT INTO SATURDAY MORNING. DESPITE THE FACT THAT THIS SYSTEM
WILL BE WEAKENING SOME AS IT COMES ACROSS...IT IS STILL EXPECTED
TO BE ABLE TO PRODUCE MODERATE TO STRONG PV ADVECTION IN THE
500-300 MB LAYER AS IT MOVES ACROSS. THE QG CONVERGENCE SHOULD BE
WEAK IN THE 850-700 MB LAYER AND THEN BECOME MODERATE IN STRENGTH
ABOVE THAT. WITH THE RAPID MOVEMENT OF THE WAVE...THE WARM AIR
ADVECTION AHEAD OF IT DOES NOT HAVE MUCH TIME TO GET GOING...BUT
STILL ENOUGH TO PRODUCE 1 TO 2 UBAR/S OF UP GLIDE ON THE 285K
ISENTROPIC SURFACE. LOW LEVEL MOISTURE IS ALREADY STARTING TO
RETURN NORTH AHEAD OF THIS SYSTEM WITH LOWER 30S DEW POINTS
SPREADING INTO NORTHERN MISSOURI. THIS MOISTURE WILL CONTINUE TO
SPREAD RAPIDLY NORTH AND SHOULD GET INTO THE EASTERN SECTIONS OF
THE FORECAST AREA OVERNIGHT. WITH THIS MOISTURE RETURN AND THE
FORCING FROM THE WAVE...EXPECT THAT THERE WILL BE LIGHT
PRECIPITATION THAT DEVELOPS AFTER MIDNIGHT AND CONTINUES INTO
EARLY SATURDAY MORNING. WITH THE INITIAL BURST OF FORCING...THE
BUFKIT SOUNDINGS SUGGEST THIS WILL BE STRONG ENOUGH TO PRODUCE
DEEP SATURATION TO ALLOW ICE TO BE IN THE CLOUDS AND FOR THE
PRECIPITATION TO START OUT AS SNOW. HOWEVER...AS THE FORCING
WEAKENS...THE SATURATION GETS SHALLOWER AND ICE IN THE CLOUDS IS
LOST AND MOST LIKELY TAKING THE PRECIPITATION OVER TO LIGHT
FREEZING DRIZZLE. THIS IS NOT EXPECTED TO LAST VERY LONG WITH JUST
A COUPLE HUNDREDTHS OF ICING POSSIBLE AND WITH SNOW AMOUNTS LESS
THAN AN INCH...NOT PLANNING TO ISSUE AN ADVISORY FOR THIS EVENT.
ONCE THIS WAVE MOVES PAST THE AREA...IT LOOKS LIKE THERE WILL BE A
PERIOD FROM SATURDAY AFTERNOON INTO THE EVENING WHERE THERE MAY
NOT BE ANY PRECIPITATION OCCURRING OR IT WOULD BE VERY LIGHT AT
BEST. IF THERE IS ANYTHING OCCURRING...IT COULD BE SOME LIGHT
FREEZING DRIZZLE WITH A SHALLOW CLOUD DEPTH AND A LACK OF ICE IN
THE CLOUDS. WILL AGAIN SHOW JUST A LITTLE BIT OF ICE ACCUMULATION
IN THESE PERIODS AS CONFIDENCE THAT THERE WILL EVEN BE ANY
PRECIPITATION OCCURRING IS PRETTY LOW.
AFTER THAT...THE PRECIPITATION CHANCES PICK UP AGAIN FOR SATURDAY
NIGHT. THE MAIN UPPER LEVEL LOW OVER THE DESERT SOUTHWEST WILL BE
LIFTING NORTHEAST ACROSS THE CENTRAL MISSISSIPPI RIVER VALLEY
TOWARD THE EASTERN GREAT LAKES. AT THE SAME TIME...A NORTHERN
STREAM SHORT WAVE TROUGH WILL BE MOVING ALONG THE CANADIAN BORDER.
THE SYSTEM COMING UP FROM THE SOUTHWEST SHOULD PRODUCE STRONG PV
ADVECTION ACROSS THE SOUTHERN PART OF THE AREA SATURDAY EVENING
WITH MODERATE PV ADVECTION ACROSS MOST OF THE AREA OVERNIGHT
SATURDAY INTO EARLY SUNDAY MORNING FROM THE NORTHERN STREAM WAVE.
THE BEST PERIOD OF QG CONVERGENCE WILL COME FROM THE SOUTHWEST
SYSTEM AND THIS IS EXPECTED TO BE WEAK TO MODERATE IN STRENGTH.
THE FRONTOGENESIS DOES NOT LOOK TO BE VERY STRONG WITH EITHER OF
THESE WAVES AND SHOULD BE CONFINED TO THE 1000-700 MB LAYER. THE
ISENTROPIC UP GLIDE AGAIN LOOKS TO BE BETWEEN 1 AND 2 UBAR/S ON
THE 285K SURFACE. THE FORCING FROM THESE TWO WAVES SHOULD ALLOW A
BAND OF DEFORMATION PRECIPITATION TO DEVELOP ON THE NORTHWEST
SIDE OF THE SURFACE LOW AS IT PASSES BY TO THE SOUTHEAST. AS THE
FORCING INCREASES AND COLDER AIR MOVES IN...THE PRECIPITATION WILL
EVENTUALLY BECOME ALL SNOW...BUT STILL SOME CONCERNS ABOUT ICE IN
THE CLOUDS FOR SATURDAY EVENING AND WILL SHOW EITHER FREEZING
DRIZZLE OR A MIX OF FREEZING AND DRIZZLE AND SNOW GOING OVER TO
ALL SNOW. THE HEAVIER PRECIPITATION AMOUNT FROM THIS SYSTEM WILL
REMAIN SOUTHEAST OF THE AREA SO GENERALLY CAN EXPECT 1 TO 2 INCHES
OF SNOW FOR MUCH OF THE AREA SATURDAY NIGHT INTO SUNDAY MORNING.
THE WINDS ON THE BACK SIDE OF THE LOW WILL INCREASE SATURDAY NIGHT
INTO SUNDAY MORNING ENOUGH TO DEFINITELY PRODUCE SOME DRIFTING
SNOW AND DEPENDING ON HOW MUCH FRESH SNOW THERE IS...SOME BLOWING
SNOW. BLOWING SNOW WAS ALREADY IN THE WESTERN SECTIONS OF THE AREA
AND INCREASED THE PROBABILITIES OF THIS AND ALSO EXPANDED THE
AREAL COVERAGE TO THE REMAINDER OF THE AREA. THESE WINDS WILL
START TO DIMINISH SOME DURING THE AFTERNOON BUT WITH THE
PLUMMETING AIR TEMPERATURES...WIND CHILL VALUES ACROSS THE WESTERN
AND NORTHERN SECTIONS WILL LIKELY BE IN THE ADVISORY RANGE FOR MUCH
OF THE DAY. BY EVENING...ADVISORY WIND CHILLS SHOULD BE OVER THE
ENTIRE AREA WITH THE POSSIBILITY OF WARNING CRITERIA BEING REACHED
IN THE NORTHERN SECTIONS FOR THE OVERNIGHT AREAS.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 321 PM CST FRI JAN 2 2015
THE BITTERLY COLD WIND CHILLS WILL CONTINUE INTO MONDAY MORNING
BEFORE BRIEFLY IMPROVING FOR THE AFTERNOON. ADVISORY CRITERIA FOR
THE WIND CHILLS LOOK TO BE POSSIBLE AGAIN MONDAY NIGHT ACROSS THE
NORTHERN AND WESTERN SECTIONS OF THE AREA.
THE MODELS HAVE BEEN SHOWING FOR A WHILE NOW THAT A FAST MOVING
NORTHERN STREAM SYSTEM SHOULD ZIP ACROSS THE REGION EARLY NEXT
WEEK. THERE HAS BEEN SOME TIMING DIFFERENCES BETWEEN...BUT THE
02.12Z GFS AND ECMWF LOOK TO BE CLOSER ON THIS. CURRENT
INDICATIONS ARE THAT THIS WILL BE ABLE TO PRODUCE MODERATE TO
STRONG PV ADVECTION IN THE 500-300 MB LAYER WITH STRONG AND DEEP
QG CONVERGENCE. STRONG WARM AIR ADVECTION IS INDICATED AHEAD OF
THE SURFACE LOW RESULTING IN UP TO 8 UBAR/S OF UP GLIDE ON THE
275K SURFACE. IF THESE FORCING SIGNALS REMAIN CONSISTENT...THIS
SYSTEM COULD HAVE THE POTENTIAL TO PRODUCE MORE SNOW THAN WHAT
OCCURS OVER THE WEEKEND. WITH THE COLD AIR ALREADY IN PLACE...SNOW
RATIOS SHOULD BE RATHER HIGH MAKING FOR LIGHT AND FLUFFY SNOW THAT
WOULD THEN EASILY BE MOVED AROUND BY THE STRONG WINDS THAT SHOULD
DEVELOP ON THE BACK SIDE OF THE SURFACE LOW. THE IMPACT FROM THIS
SYSTEM COULD BE GREATER THAN THE WEEKEND AND THERE IS THE
POTENTIAL FOR WINTER HEADLINES AS IT COMES THROUGH. WIND CHILLS
WILL AGAIN BECOME A CONCERN BEHIND THIS SYSTEM AND WIND CHILL
ADVISORIES WILL LIKELY BE NEEDED TUESDAY NIGHT INTO WEDNESDAY
MORNING AND AGAIN WEDNESDAY NIGHT INTO THURSDAY MORNING. WARNINGS
MAY BE NEEDED AS WELL FOR PARTS OF THE AREA TUESDAY
NIGHT/WEDNESDAY MORNING.
&&
.AVIATION...(FOR THE 00Z TAFS THROUGH 00Z SATURDAY EVENING)
ISSUED AT 600 PM CST FRI JAN 2 2015
WARM AIR ADVECTION AND ISENTROPIC LIFT AHEAD OF A STRONG SHORT
WAVE TROUGH...CURRENTLY OVER NEBRASKA...WILL BRING IFR/MVFR CLOUDS
TO THE AREA AFTER 03.08Z. THESE CLOUDS WILL THEN LINGER THROUGH
THE REMAINING OF THE TAF PERIOD. PRECIPITATION WILL MOVE INTO KLSE
AROUND 03.08Z AND THEN LINGER THROUGH 03.12Z. THIS PRECIPITATION
WILL START OFF AS SNOW AND THEN AS WE LOSE ICE CRYSTALS ALOFT IT
WILL TRANSITION TO FREEZING DRIZZLE AS IT COMES TO AN END.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...04
LONG TERM...04
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
405 AM EST SAT JAN 3 2015
.SYNOPSIS...
ISSUED AT 400 PM EST FRI JAN 2 2015
LOW PRESSURE WILL MOVE OUT OF THE SOUTHWEST TOWARDS THE SOUTHERN
GREAT LAKES SATURDAY NIGHT. A LARGE AREA OF MIXED PRECIPITATION
WAS OVERSPREADING THE AREA THIS MORNING AND WILL TRANSITION TO
RAIN AS THE MORNING PROGRESSES. HIGHS TODAY WILL RANGE FROM THE
MIDDLE 30S NORTHWEST TO NEAR 50 IN THE SOUTHEAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST SAT JAN 3 2015
IMPRESSIVE SRN STREAM SW TROUGH NOTED IN VAPOR THIS MORNING AND
BEGINNING TO LIFT OUT OF NM. THIS SYS WILL PHASE QUICKLY TONIGHT
W/NRN STREAM SW AMPLIFYING SEWD OUT OF THE NRN ROCKIES RESULTING IN
A RAPID NEWD EJECTION INTO SE CANADA BU SUN MORNING.
BROAD LOW-MID LVL MSTR SURGE JUST NOW GETTING UP INTO THE AREA
W/MORE VIGOROUS PRECIP DVLPMNT NOTED IN COMPOSITE RADAR IMAGERY BACK
ACRS CNTRL IL INTO WRN IN AND POSES AN ICING PROB EARLY ON
W/CURRENT SFC TEMPS IN THE UPR 20S. HWVR LL WAA QUITE INTENSE AS
NOTED OVR SRN IL/IN AND XPCD TO PROGRESS NWD THROUGH THIS MORNING.
GIVEN GOOD 00Z CONSENSUS W/CORRESPONDING RUC NOD TO SFC TEMPS CUT
BACK TIMING OF ADVISORY ACRS FAR SRN TIER OF COUNTIES YET WILL HOLD
W/REMAINDER OF ADVISORY SEGMENTS PER LTL XPCD SFC BASED WARMING
WILL OCCUR UNTIL MID-LT MORNING TIED TO DEEPER ERLY FLW TRAJECTORIES
AND MUCH LWR THETA-E AIR ORIGINATING FM OLD POLAR RIDGE.
REGARDLESS LL WAA WILL OVERWHELM SHALLOW SFC BASED COLD LYR BY LT
MORNING/ERLY AFTN S-N W/A DECENT RAIN EVENT XPCD ESP SE HALF. MID
LVL DRY SLOT WILL OVERSPREAD AREA LT THIS AFTN WEST AND OVERNIGHT
EAST ALTHOUGH TEMPS WILL FAIRLY MILD. EXCEPTION WILL BE FAR WEST
WHERE INTENSE LL CAA WING WILL BEGIN TO WRAP SEWD BEHIND DEPARTING
SFC LOW. LEFT OVER DEFORMATION ZONE AND RAPID INFLUX OF COLD AIR
WILL LEAD TO A RAPID CHG OVR TO ACCUMULATING SNOW FAR NW AND
EXPANDING SEWD DURING THE DAY AS MSTR FLUX OFF LK MI TAKES OFF. SHLD
SEE A PD OF ROBUST LK ENHANCEMENT THROUGHOUT THE NW HALF SUN AFTN
W/AT LEAST AN INCH OR TWO OF SNOWFALL XPCD.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 403 AM EST SAT JAN 3 2015
BITTERLY COLD CONDITIONS CAN BE EXPECTED FOR MUCH OF THE LONG TERM
FORECAST DURING THE UPCOMING WEEK. STRONG COLD AIR ADVECTION WILL BE
OCCURRING AT THE START OF THIS PERIOD SUNDAY NIGHT. A STRONG UPPER
LEVEL DISTURBANCE WILL SUPPORT THE DEVELOPMENT OF A CLIPPER TYPE
SYSTEM THAT SHOULD RACE ACROSS THE AREA MONDAY NIGHT INTO EARLY
TUESDAY. FAVORED THE ECMWF RUN TO RUN CONSISTENCY AND HANDLING OF
THIS SYSTEM. TEMPERATURES WILL BE COLD ENOUGH FOR ALL SNOW...WITH 3
TO 6 INCHES EXPECTED BY MID DAY TUESDAY. GIVEN FRESH SNOW COVER AND
850 MB TEMPERATURES DROPPING WELL BELOW -20...OVERNIGHT LOWS SHOULD
BE ABLE TO FALL BELOW ZERO. LOWERED TEMPS TUESDAY NIGHT THROUGH
THURSDAY NIGHT IN THIS REGARD. WIND CHILLS WILL DIP TO -20 AT TIMES
DURING THE MIDDLE OF THE WEEK...WITH ADVISORY CONDITIONS LIKELY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 134 AM EST SAT JAN 3 2015
VFR CONDS TO START WILL RAPIDLY GO DOWNHILL PRIOR TO DAYBREAK AS
PCPN OVERSPREADS THE TERMINALS. UPSTREAM OBS TRENDS DICTATE
WIDESPREAD LIFR CONDS DVLPG BY MID MORNING AND CONTG THROUGH MUCH IF
NOT ALL OF THIS PD. FZRA NR TERM XPCD TO CHG TO RA SHORTLY AFT
DAYBREAK.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING
FOR INZ008-009-012>018.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR INZ006-
007.
WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ003>005.
WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
INZ020-022>027-032>034.
MI...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MIZ079>081.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077-
078.
OH...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR OHZ004-
005-015-016.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR OHZ001-
002.
WINTER WEATHER ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
OHZ024-025.
LM...NONE.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
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WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
343 AM EST SAT JAN 3 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 335 AM EST SAT JAN 3 2015
08Z SFC ANALYSIS SHOWS A WARM FRONT LIFTING THROUGH EASTERN KENTUCKY
IN CONJUNCTION WITH AN AREA OF LOW PRESSURE DEVELOPING TO THE
SOUTHWEST. SOME LIGHT RAIN SHOWERS HAVE BEEN ASSOCIATED WITH THIS
BOUNDARY ALONG WITH PATCHES OF FOG AND LOW CIGS. TEMPERATURES ARE
RATHER MILD ACROSS THE AREA WITH MID 30S FOUND NORTH OF THE FRONT AND
LOW 40S TO THE SOUTH OF IT. DEWPOINTS THROUGH THE AREA ARE WITHIN A
DEGREE OR TWO OF THE AIR TEMPERATURE.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST. THEY ALL DEPICT A CLOSED LOW CURRENTLY OVER SOUTHERN
NEW MEXICO BEING PICKED UP BY THE NORTHERN STREAM FLOW TODAY AND
MOVING THROUGH THE OHIO VALLEY ON SUNDAY AS A FULL LATITUDE TROUGH.
THE LATEST ECMWF AND NAM ARE THE MOST SIMILAR WITH THIS TRANSITION
AND WERE LEANED ON MOST FOR THIS FORECAST. IN ADDITION...THE LATEST
HRRR WAS INCORPORATED INTO THE NEAR TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE A RATHER WARM EARLY JANUARY DAY ACROSS
EASTERN KENTUCKY AS SCATTERED SHOWERS MOVE THROUGH DURING THE MORNING
HOURS. AN INVERSION WILL KEEP THE GUSTY WINDS JUST OFF THE SFC FROM
AFFECTING THOSE OF US AT GROUND LEVEL. HOWEVER...THIS COULD BREAK BY
AFTERNOON AND BRING SOME OF THOSE GUSTY WINDS TO THE SFC. IN
ADDITION...THE DEEPENING LOW TO THE WEST AND ITS WARM FRONT NORTH OF
THE AREA WILL SET THE STAGE FOR A POTENTIAL OF MAINLY ELEVATED
THUNDERSTORMS...THOUGH THEY COULD BECOME SFC BASED...ESPECIALLY IF
THE CLOUDS THIN OR BREAK OVER THIS PART OF THE STATE LATER TODAY. THE
HIGHEST POPS AND STEADIER RAINS SHOULD STAY WEST OF THE AREA FOR MUCH
OF THE DAY...THOUGH IF ANY BANDS DO SET UP AHEAD OF THE COLD FRONT
WE COULD SEE HEAVY TO EXCESSIVE RAINS GIVEN THE VERY HIGH PWATS FOR
THIS PART OF THE YEAR. MOST LIKELY...THOUGH...THE BEST RAINS WILL STAY
TO THE WEST OF THE AREA...CLOSER TO THE CORE OF THE SYSTEM...UNTIL
LATER IN THE EVENING AND OVERNIGHT WHEN THE COLD FRONT LUNGES THIS
WAY. WITH THIS PASSAGE...EXPECT A PERIOD OF HEAVY RAIN AND POSSIBLE
THUNDERSTORMS ALONG WITH GUSTY SOUTHWEST WINDS. AT THIS POINT WILL
HOLD OFF ON ANY FLOOD WATCHES GIVEN THE EXPECTATION OF DOWNSLOPING IN
THE EAST AND SOME DRY SLOTTING AHEAD OF THE COLD FRONT. THE POTENTIAL
FOR HEAVY RAINS TONIGHT WILL BE HIT HARD IN THE HWO ALONG WITH
THE CONCERN FOR GUSTY WINDS. THE FRONT GOES THROUGH SHORTLY AFTER 12Z
SUNDAY WITH FALLING TEMPERATURES EXPECTED THROUGH THE REST OF THE
DAY. WOULD ALSO EXPECT SOME WRAP AROUND AND UPSLOPE PCPN TO DEVELOP
IN THE FRONT/S WAKE LATER IN THE AFTERNOON. THIS...COMBINED WITH
FALLING TEMPERATURES...WILL LIKELY RESULT IN SOME LIGHT SNOW SHOWERS
AROUND THE AREA INTO SUNDAY EVENING. WHILE NO ACCUMULATIONS ARE
EXPECTED FROM THIS...THERE COULD BE BRIEF DUSTINGS WHERE ANY HEALTHY
SNOW SHOWER PASSES. WILL ADD THIS FLEETING SNOW POTENTIAL TO THE
HWO...AS WELL.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPS...TD...AND
WINDS THROUGH 21Z TODAY AND THEN THE SUPERBLEND THROUGH 00Z MONDAY.
ONLY SLIGHTLY TWEAKED POINT TEMPERATURE DATA FOR MAXES AND MINS. AS
FOR POPS...FAVORED A BLEND OF THE HRRR AND NAM12 EARLY THEN MAINLY
THE NAM12 TONIGHT INTO SUNDAY. GENERALLY UNDERCUT MOS TODAY...
ESPECIALLY EAST...WENT CATEGORICAL TONIGHT...AND THEN ENDED UP
HIGHER THAN MOS FOR SUNDAY AFTERNOON AND EVENING.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 AM EST SAT JAN 3 2015
THE UPPER LEVEL PATTERN THROUGH THE EXTENDED FORECAST PERIOD WILL
FEATURE A BROAD TROUGH OVER THE GREAT LAKES AND NEW ENGLAND REGIONS
WITH A SERIES OF SHORTWAVES ROUNDING THE BASE OF THE TROUGH AND
MOVING THROUGH THE LOWER GREAT LAKES AND OH VALLEY REGION. TOWARDS
THE END OF THE EXTENDED PORTION OF THE FORECAST ON THURSDAY AND INTO
FRIDAY A STRONG JET STREAK DIVES SOUTHEAST OUT OF CENTRAL CANADA AND
INTO THE LOWER TN VALLEY AS THE LONGWAVE TROUGH OVER THE EASTERN
CONUS DEEPENS AND A POTENT SHORTWAVE MOVES THROUGH THE MID ATLANTIC
STATES AND OFF THE ATLANTIC COAST. FOR THE MOST PART...THE MODELS
AGREE WITH WITH THE OVERALL PROGRESSION OF THE LONGWAVE PATTERN.
CLOSER TO THE SURFACE...A COLD FRONT WILL EXIT EASTERN KENTUCKY ON
SUNDAY NIGHT WITH SOME WRAP AROUND MOISTURE...THOUGH
SHALLOW...MAKING IT THROUGH EASTERN KENTUCKY. WITH THE COLDER AIR
FILTERING INTO THE AREA IN EARNEST...THIS WILL RESULT INTO A CHANGE
OVER TO SOME SNOW SHOWERS AND IS EXPECTED TO BE SHORT IN DURATION AS
THE MOISTURE AND UPPER TROUGH WILL BE QUICK TO EXIT. DO NOT EXPECT
MORE THAN A DUSTING WITH THIS ACTIVITY. COLDER AIR WILL BE WELL
ENTRENCHED THROUGH THE AREA FOR MONDAY AND TUESDAY AND ESPECIALLY
THROUGH THE REST OF THE EXTENDED. THE NEXT COLD FRONT WILL PUSH
THROUGH THE OH VALLEY ON TUESDAY AND TUESDAY NIGHT. IN NORTHWEST
FLOW...THE BEST MOISTURE AND LIFT WITH THIS FEATURE APPEARS TO BE
NORTH OF THE OH RIVER AND THEREFORE LITTLE PRECIP POSSIBLE INTO
EASTERN KENTUCKY. THIS THINKING IS INLINE WITH THE RESULT OF THE ALL
MODEL BLEND AND AS SUCH HAVE STAYED WITH A DRY FORECAST. DID GO WITH
SOME FLURRIES IN THE VERY NORTH THOUGH WITH NO MEASURABLE PRECIP
EXPECTED.
THIS FRONT MOVES THROUGH TUESDAY NIGHT AND QUITE AN ARCTIC AIRMASS
FOLLOWS IN BEHIND THIS FEATURE. ARCTIC HIGH PRESSURE WILL MOVE
SOUTHEAST INTO THE LOWER MS RIVER VALLEY AND WITH IT...SOME VERY
COLD AND DRY AIR. THIS WILL KEEP EASTERN KENTUCKY DRY FOR THE REST
OF THE EXTENDED FORECAST PERIOD AND BRING SOME NEAR ZERO
TEMPERATURES FOR THURSDAY MORNING AND DRY AIR. DEW POINTS FOR
THURSDAY WILL DROP INTO THE NEGATIVE DIGITS AND ONLY RISE INTO THE
TEENS FOR FRIDAY. A COLD AND DRY TREND WILL BE IN STORE FOR THE END
OF NEXT WEEK.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 100 AM EST SAT JAN 3 2015
SOUTH-SOUTHEAST FLOW AHEAD OF AN APPROACHING WARM FRONT WILL
STRENGTHEN OVERNIGHT AS IT PUSHES NORTHWARD. THIS WILL YIELD SOME
DOWNSLOPING FLOW OFF THE HIGHER TERRAIN ACROSS FAR EASTERN KENTUCKY.
THIS SHOULD HELP KEEP CIGS A BIT HIGHER THROUGH THE NIGHT...OVER THE
EASTERN PARTS OF THE FORECAST AREA. THE BEST CHANCES FOR PERIODS OF
MVFR CIGS WILL BE ACROSS SOUTH-CENTRAL KENTUCKY...WHICH WILL BE LESS
INFLUENCED BY THIS DOWNSLOPING FLOW. WHILE SPRINKLES AND LIGHT RAIN
SHOWERS WILL BE AROUND OVERNIGHT...THE BEST RAIN CHANCES SHOULD HOLD
OFF UNTIL LATER SATURDAY MORNING. ACCORDINGLY...MAINLY VFR
CONDITIONS SHOULD PREVAIL FOR THE EASTERN TAF SITES. MAIN AVIATION
CONCERN WILL BE DEVELOPING LLWS LATE TONIGHT AND TOMORROW AS WINDS
STRENGTHEN JUST OFF THE SURFACE TO BETWEEN 40 AND 45 KNOTS. THIS WILL
LIKELY PERSIST THROUGH AT LEAST THE MORNING AS THE INVERSION HOLDS
TOUGH. DO EXPECT SOME MIXING OF THE GUSTS TO THE SFC SATURDAY
AFTERNOON WITH SOME BREAKS IN THE SKY COVER POSSIBLE ONCE WE ARE IN
THE DEVELOPING SYSTEM/S WARM SECTOR. CANNOT RULE OUT A STRAY
THUNDERSTORM FOR SATURDAY AFTERNOON BUT FOR NOW HAVE LEFT THEM OUT OF
THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
335 AM EST SAT JAN 3 2015
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 335 AM EST SAT JAN 3 2015
08Z SFC ANALYSIS SHOWS A WARM FRONT LIFTING THROUGH EASTERN KENTUCKY
IN CONJUNCTION WITH AN AREA OF LOW PRESSURE DEVELOPING TO THE
SOUTHWEST. SOME LIGHT RAIN SHOWERS HAVE BEEN ASSOCIATED WITH THIS
BOUNDARY ALONG WITH PATCHES OF FOG AND LOW CIGS. TEMPERATURES ARE
RATHER MILD ACROSS THE AREA WITH MID 30S FOUND NORTH OF THE FRONT AND
LOW 40S TO THE SOUTH OF IT. DEWPOINTS THROUGH THE AREA ARE WITHIN A
DEGREE OR TWO OF THE AIR TEMPERATURE.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST. THEY ALL DEPICT A CLOSED LOW CURRENTLY OVER SOUTHERN
NEW MEXICO BEING PICKED UP BY THE NORTHERN STREAM FLOW TODAY AND
MOVING THROUGH THE OHIO VALLEY ON SUNDAY AS A FULL LATITUDE TROUGH.
THE LATEST ECMWF AND NAM ARE THE MOST SIMILAR WITH THIS TRANSITION
AND WERE LEANED ON MOST FOR THIS FORECAST. IN ADDITION...THE LATEST
HRRR WAS INCORPORATED INTO THE NEAR TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE A RATHER WARM EARLY JANUARY DAY ACROSS
EASTERN KENTUCKY AS SCATTERED SHOWERS MOVE THROUGH DURING THE MORNING
HOURS. AN INVERSION WILL KEEP THE GUSTY WINDS JUST OFF THE SFC FROM
AFFECTING THOSE OF US AT GROUND LEVEL. HOWEVER...THIS COULD BREAK BY
AFTERNOON AND BRING SOME OF THOSE GUSTY WINDS TO THE SFC. IN
ADDITION...THE DEEPENING LOW TO THE WEST AND ITS WARM FRONT NORTH OF
THE AREA WILL SET THE STAGE FOR A POTENTIAL OF MAINLY ELEVATED
THUNDERSTORMS...THOUGH THEY COULD BECOME SFC BASED...ESPECIALLY IF
THE CLOUDS THIN OR BREAK OVER THIS PART OF THE STATE LATER TODAY. THE
HIGHEST POPS AND STEADIER RAINS SHOULD STAY WEST OF THE AREA FOR MUCH
OF THE DAY...THOUGH IF ANY BANDS DO SET UP AHEAD OF THE COLD FRONT
WE COULD SEE HEAVY TO EXCESSIVE RAINS GIVEN THE VERY HIGH PWATS FOR
THIS PART OF THE YEAR. MOST LIKELY...THOUGH...THE BEST RAINS WILL STAY
TO THE WEST OF THE AREA...CLOSER TO THE CORE OF THE SYSTEM...UNTIL
LATER IN THE EVENING AND OVERNIGHT WHEN THE COLD FRONT LUNGES THIS
WAY. WITH THIS PASSAGE...EXPECT A PERIOD OF HEAVY RAIN AND POSSIBLE
THUNDERSTORMS ALONG WITH GUSTY SOUTHWEST WINDS. AT THIS POINT WILL
HOLD OFF ON ANY FLOOD WATCHES GIVEN THE EXPECTATION OF DOWNSLOPING IN
THE EAST AND SOME DRY SLOTTING AHEAD OF THE COLD FRONT. THE POTENTIAL
FOR HEAVY RAINS TONIGHT WILL BE HIT HARD IN THE HWO ALONG WITH
THE CONCERN FOR GUSTY WINDS. THE FRONT GOES THROUGH SHORTLY AFTER 12Z
SUNDAY WITH FALLING TEMPERATURES EXPECTED THROUGH THE REST OF THE
DAY. WOULD ALSO EXPECT SOME WRAP AROUND AND UPSLOPE PCPN TO DEVELOP
IN THE FRONT/S WAKE LATER IN THE AFTERNOON. THIS...COMBINED WITH
FALLING TEMPERATURES...WILL LIKELY RESULT IN SOME LIGHT SNOW SHOWERS
AROUND THE AREA INTO SUNDAY EVENING. WHILE NO ACCUMULATIONS ARE
EXPECTED FROM THIS...THERE COULD BE BRIEF DUSTINGS WHERE ANY HEALTHY
SNOW SHOWER PASSES. WILL ADD THIS FLEETING SNOW POTENTIAL TO THE
HWO...AS WELL.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPS...TD...AND
WINDS THROUGH 21Z TODAY AND THEN THE SUPERBLEND THROUGH 00Z MONDAY.
ONLY SLIGHTLY TWEAKED POINT TEMPERATURE DATA FOR MAXES AND MINS. AS
FOR POPS...FAVORED A BLEND OF THE HRRR AND NAM12 EARLY THEN MAINLY
THE NAM12 TONIGHT INTO SUNDAY. GENERALLY UNDERCUT MOS TODAY...
ESPECIALLY EAST...WENT CATEGORICAL TONIGHT...AND THEN ENDED UP
HIGHER THAN MOS FOR SUNDAY AFTERNOON AND EVENING.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 306 PM EST FRI JAN 2 2015
THE EXTENDED PERIOD BEGINS WARM AND WET ON SUNDAY MORNING JANUARY
THE FOURTH. A LARGE SWATH OF LIGHT TO MODERATE RAIN IS PROGGED TO
MOVE ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS ALONG AND JUST
AHEAD OF A VERY POTENT COLD FRONT. THE RAIN IS EXPECTED TO GRADUALLY
TAPER OFF FROM WEST TO EASTERN SUNDAY AND SUNDAY NIGHT AS THE FRONT
MOVES THROUGH. THE PRECIPITATION SHOULD BE OUT OF THE AREA BY LATE
SUNDAY NIGHT. AFTER THAT...A FRIGID ARCTIC AIR MASS IS EXPECTED TO
SETTLE OVER THE REGION FOR A FEW DAYS. AFTER A MODEST COOL DOWN
SUNDAY NIGHT...DURING WHICH TIME TEMPERATURES ARE EXPECTED TO DROP
INTO THE 20S ACROSS THE AREA...A SECOND REINFORCING SHOT OF COLD AIR
IS EXPECTED TO INVADE THE AREA TUESDAY NIGHT...AS A FAST MOVING
CLIPPER SYSTEM PASSES BY JUST TO OUR NORTH. BASED ON THE LATEST MOS
GUIDANCE AND MODEL SOUNDINGS...THE MERCURY COULD DROP INTO THE TEENS
AND LOW 20S TUESDAY NIGHT...AND PERHAPS EVEN INTO THE SINGLE DIGITS
WEDNESDAY NIGHT. THE CULPRIT OF THESE FRIGID TEMPERATURES WOULD COME
IN THE FORM OF A LARGE RIDGE OF ARCTIC HIGH PRESSURE THAT IS
EXPECTED TO SETTLE OVER THE EASTERN CONUS MID WEEK. AFTER SUNDAY AND
SUNDAY NIGHT...THE ONLY PRECIPITATION THAT MAY AFFECT THE AREA WOULD
COME TUESDAY AFTERNOON AND EVENING AS THE CLIPPER SYSTEM MOVES PAST.
ANY RAIN OR SNOW THAT FALLS THAT DAY WOULD LIKELY OCCUR NORTH OF THE
MOUNTAIN PARKWAY WITH LITTLE ACCUMULATION EXPECTED. THE REST OF THE
WEEK IS FORECAST TO BE DRY AND QUITE COLD. HIGHS ON WEDNESDAY AND
THURSDAY MAY NOT CLIMB OUT OF THE 20S. MONDAY LOOKS TO BE PRETTY
COLD AS WELL...WITH HIGHS IN THE 30S ANTICIPATED ON THAT DAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 100 AM EST SAT JAN 3 2015
SOUTH-SOUTHEAST FLOW AHEAD OF AN APPROACHING WARM FRONT WILL
STRENGTHEN OVERNIGHT AS IT PUSHES NORTHWARD. THIS WILL YIELD SOME
DOWNSLOPING FLOW OFF THE HIGHER TERRAIN ACROSS FAR EASTERN KENTUCKY.
THIS SHOULD HELP KEEP CIGS A BIT HIGHER THROUGH THE NIGHT...OVER THE
EASTERN PARTS OF THE FORECAST AREA. THE BEST CHANCES FOR PERIODS OF
MVFR CIGS WILL BE ACROSS SOUTH-CENTRAL KENTUCKY...WHICH WILL BE LESS
INFLUENCED BY THIS DOWNSLOPING FLOW. WHILE SPRINKLES AND LIGHT RAIN
SHOWERS WILL BE AROUND OVERNIGHT...THE BEST RAIN CHANCES SHOULD HOLD
OFF UNTIL LATER SATURDAY MORNING. ACCORDINGLY...MAINLY VFR
CONDITIONS SHOULD PREVAIL FOR THE EASTERN TAF SITES. MAIN AVIATION
CONCERN WILL BE DEVELOPING LLWS LATE TONIGHT AND TOMORROW AS WINDS
STRENGTHEN JUST OFF THE SURFACE TO BETWEEN 40 AND 45 KNOTS. THIS WILL
LIKELY PERSIST THROUGH AT LEAST THE MORNING AS THE INVERSION HOLDS
TOUGH. DO EXPECT SOME MIXING OF THE GUSTS TO THE SFC SATURDAY
AFTERNOON WITH SOME BREAKS IN THE SKY COVER POSSIBLE ONCE WE ARE IN
THE DEVELOPING SYSTEM/S WARM SECTOR. CANNOT RULE OUT A STRAY
THUNDERSTORM FOR SATURDAY AFTERNOON BUT FOR NOW HAVE LEFT THEM OUT OF
THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...GREIF
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
303 AM EST Sat Jan 3 2015
.SHORT TERM (Now through Sunday)...
Issued at 300 AM EST Sat Jan 3 2015
Latest water vapor imagery with 500 mb RAP heights shows a deep
closed low across southern New Mexico while a ridge lies off the
Florida coast. In between, broad southwesterly flow has been
bringing a very moist and warm air mass into the Ohio Valley. At the
surface, high pressure is departing the region, allowing a warm
front to lift through TN and KY. Early morning temperatures range
from the upper 30s across southern IN to upper 40s across southern
KY.
As a surface low deepens to our west, plan on the warm front to lift
through Kentucky this morning and reach southern Indiana by early
afternoon. As the region becomes well within the warm sector,
temperatures will top out right around 60 degrees for much of the
area. Southern Kentucky locations are most likely to get into the
lower 60s. Southerly winds will increase throughout the day as well,
as soundings show a rather strong 850 mb jet of 55+ knots at about
2-3kft. An inversion in the lowest levels of the atmosphere should
keep these strong winds from mixing down, but it will still be gusty
at times today.
Precipitation this morning is expected to be on the lighter side,
mainly in the form of drizzle or light rain showers. Precipitation
chances/coverage will then steadily increase today as isentropic
upglide picks up and the region becomes more in the nose of the
850mb moisture transport axis. The greatest forcing/lift arrives by
mid/late afternoon through the evening hours as the cold front
swings through the state. Just ahead of this front, PWATs climb to
1.6 inches, which would be record values for this time of year for
BNA/ILN. Overall, a very moist air mass will be in place and though
the system is expected to be progressive, any training showers will
be capable of some moderate to locally heavy rainfall, especially
across the southern forecast area. Plan on rainfall amounts to range
from 1.5 to locally 2 inches across the area through Sunday morning.
Thunder chances are still included in the forecast as MUCAPE values
are progged to be around 500 J/kg this afternoon. Tonight`s low will
be quite mild, held up due to lingering precipitation and southerly
flow. Plan on readings to only into the mid 40s to lower 50s,
warmest east of I-65.
Cold air advection kicks in between midnight and sunrise Sunday,
resulting in a steady drop in temperatures during the day Sunday.
Morning readings in the mid 40s to near 50 are expected to fall into
the mid 30s to around 40 by mid/late afternoon. At the same time,
03.00z guidance continues to show lingering wrap around moisture
behind the departing low pressure system. As temperatures aloft
reach -8 to -10c, there may be enough saturation left to squeeze out
a few snowflakes across southern Indiana and northern Kentucky.
Otherwise, Sunday afternoon will be noticeably colder especially
given cloudy skies and a brisk west/northwest wind 15-20 mph, making
it feel more like the middle 20s at times.
.LONG TERM (Sunday night through Friday)...
Issued at 257 AM EST Sat Jan 3 2015
...Very Cold Temperatures and Wind Chills Mid-Week...
Canadian high pressure crossing the region Sunday night and Monday
will bring a quick shot of chilly air. Low clouds will likely hang
around for much of the night Sunday night, but should clear out just
in time to allow sunrise readings to drop into the 15-20 degree
range. We`ll have sunshine on Monday but the mercury will only
recover into the middle 20s in southern Indiana and around 30 in
Kentucky.
A quick moving clipper type system will zip by to our north Monday
night/Tuesday. The models have trended slightly faster and farther
south with this feature. Looking at atmospheric cross-sections,
even in the northernmost reaches of the LMK CWA around Madison,
there`s quite a bit of dry low level air Monday night, and then on
Tuesday when some low level moisture does move in it`s very
shallow. So, it still appears, at least for now, that measurable
precipitation is unlikely with this system. Will, however, include
a chance of flurries generally north of a Salem-Frankfort-Carlisle
line. Also, it should be noted that the GEM brings accumulating
snows to southern Indiana and northern Kentucky late Monday night.
This solution is an outlier, but these types of systems can do
surprising things sometimes, so it`s still something to keep an eye
on.
Strong Canadian high pressure will then invade Tuesday night through
Thursday. A tight surface pressure gradient on the nose of the
incoming high pressure Wednesday could give us some afternoon gusts
around 20 mph. With temperatures reaching only into the teens in
southern Indiana and the 20s in Kentucky, Wednesday will be a cold
day.
Then it will get worse. Lows Wednesday night, as the cold heart of
the Canadian high moves in, will be in the 0 to 5 degree range. Add
to that a northwest breeze around 10 mph and we could be looking at
advisory level wind chills of 10 to 15 degrees below zero as the
kids head out to the bus stops Thursday morning. Highs Thursday
afternoon will struggle to reach 20.
A cold front will sweep through the Ohio and Tennessee Valleys
Thursday night/Friday. However, the Gulf of Mexico will be
completely shut off by the departing mid-week high, so no
precipitation is expected.
&&
.AVIATION (06Z TAF Update)...
Issued at 1225 AM EST Sat Jan 3 2015
Plan on lowering clouds through the night as batch of IFR clouds
across TN lifts north through KY. Drizzle or light rain showers will
persist and increase in coverage toward sunrise. Mainly IFR ceilings
expected to remain in place through the day as warm front lifts into
Indiana. LLWS threat at all TAF sites looks good as very strong 2kft
jet increases to 55kts by late morning to early afternoon. Soundings
show the inversion remaining intact for much of the day, supporting
the LLWS threat into the afternoon hours. The highest coverage of
showers and threat for thunderstorms comes in the mid afternoon
through the evening hours associated with a cold front passage.
Decided to include VCTS at BWG/SDF/LEX as there should be a line of
isolated/scattered thunderstorms moving across KY. Toward the end of
TAF period, precipitation coverage will decrease as winds become
westerly. Weakening but still strong 850mb jet may allow higher
winds to mix down post front as well, with gusts up to 30-35 mph
possible.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........ZBT
Long Term.........13
Aviation..........ZBT
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON KY
125 AM EST SAT JAN 3 2015
.UPDATE...
ISSUED AT 125 AM EST SAT JAN 3 2015
BASED ON CURRENT RADAR AND THE LATEST GUIDANCE FROM THE HRRR AND
NAM12 HAVE ADJUSTED POPS AND WX THROUGH THE REST OF THE NIGHT. ALSO
FINE TUNED T AND TD GRIDS PER THE LATEST OBS...TRENDS...AND CONSSHORT
GUIDANCE THESE HAVE BEEN SENT TO THE NDFD AND WEB SERVERS.
UPDATE ISSUED AT 1032 PM EST FRI JAN 2 2015
SHOWERS HAVE ATTEMPTED TO PUSH INTO SOUTHERN KENTUCKY...BUT DRY AIR
SEEMS TO BE WINNING OUT AS MUCH OF THIS APPEARS TO BE WEAKENING AS IT
HEADS NORTH. IN FACT...LONDON CIGS HAVE INCREASED TO 9KFT. THIS
DEMONSTRATES THE ABUNDANCE OF LOW LEVEL DRY AIR IN PLACE. THUS...PLAN
TO SCALE BACK POPS A BIT OVER THE NEXT FEW HOURS...BUT LEAVE
SCATTERED COVERAGE IN THE SOUTHWEST AND WEST...TAPERING OFF TO
ISOLATED IN THE EAST. THIS MAY STILL BE OVERDONE AS DOWNSLOPING WINDS
CONTINUE TO ERODE PRECIPITATION AS IT HEADS NORTH. FORCING APPEARS TO
JUST BE TOO WEAK TO OVERCOME THE DRY AIR. MODELS ARE SHOWING A BETTER
SURGE OF LIFT AND MOISTURE BETWEEN 7 AND 10 AM IN THE MORNING.
PERHAPS THIS MAY BE THE BEST OPPORTUNITY FOR BETTER SHOWER COVERAGE.
HOWEVER...FOR NOW...OPTING TO LEAVE THE FORECAST ALONE AND ONLY TOUCH
THE NEXT FEW HOURS TO ADJUST FOR THE CURRENT TRENDS. DID ADJUST WINDS
UPWARDS ON THE HIGH TERRAIN IN THE SOUTHEAST LATE TONIGHT THROUGH
TOMORROW AS 900MB WINDS INCREASE TO AROUND 40 KNOTS. THIS SHOULD
PRODUCE SOME STRONG GUSTY WINDS ON THE HIGHER TERRAIN. WITH INVERSION
HOLDING TOUGH ON SATURDAY...WINDS MAY NOT TURN ALL THAT GUSTY
ELSEWHERE. HOWEVER...IF WE CAN GET SOME CLEARING...THAT WOULD
CERTAINLY HELP TO MIX DOWN SOME STRONGER WINDS.
UPDATE ISSUED AT 853 PM EST FRI JAN 2 2015
WHILE ONLY A FEW SPRINKLES REMAIN ACROSS THE NORTH PRESENTLY...AN
AREA OF RAIN HAS DEVELOPED ACROSS CENTRAL TENNESSEE. THIS RAIN WILL
BE PUSHING NORTHEAST INTO SOUTH CENTRAL KENTUCKY OVER THE NEXT FEW
HOURS. HAVE ADJUSTED POPS TO TIME THIS AREA OF PRECIPITATION
NORTHWARD ACROSS CENTRAL KENTUCKY. THE EASTWARD EXTENT IS STILL IN
QUESTION DUE TO DRIER DOWNSLOPING FLOW (HIGHER CIG HEIGHTS)...SO
WILL GO WITH AN EAST TO WEST GRADIENT IN POPS. HRRR HAS PICKED UP ON
THIS FEATURE WITH THE LAST FEW RUNS AND SHOWS ANOTHER LULL AS THIS
AREA PUSHES NORTH BY EARLY MORNING. HOWEVER...WILL LEAVE SOME LOW
POPS IN THROUGH THE REMAINDER OF THE NIGHT AS WE COULD SEE SHOWERS
POP UP AT ANY TIME GIVEN THE SATURATED ENVIRONMENT. HOWEVER...OUTSIDE
OF THE RAIN PUSHING NORTHWARD NOW...IT LOOKS LIKE THE ACTIVITY
THROUGH THE REMAINDER OF THE NIGHT MAY BE MORE ISOLATED.
UPDATE ISSUED AT 544 PM EST FRI JAN 2 2015
UPDATED FORECAST TO LOWER POPS THROUGH THE EVENING. STILL HAVE MODEST
DEWPOINT DEPRESSIONS OUT THERE. A FEW BETTER RETURNS ARE COMING OUT
OF CENTRAL KENTUCKY...BUT FOR THE MOST PART THE BETTER RETURNS ARE
VERY ISOLATED. IN FACT...NOT MANY STATIONS REPORTING MEASURABLE
PRECIPITATION EVEN WITH THE HEAVIER RETURNS. THUS...WILL CUT DOWN
POPS THROUGH 06Z. HRRR/RAP CONTINUE TO SUPPORT VERY LITTLE EVEN
THROUGH THE REST OF THE NIGHT. THIS COULD BE THE CASE GIVEN THE
SOUTH/SOUTHEAST WINDS WILL ONLY STRENGTHEN AS WE HEAD THROUGH THE
NIGHT...KEEPING THE FLOW DOWNSLOPING INTO EASTERN KENTUCKY.
HOWEVER...NOT WILLING TO GO TOO LOW QUITE YET AS BETTER JET ARRIVES
TOWARDS DAYBREAK AND COULD KICK START THINGS LATE TONIGHT.
HOWEVER...UNTIL THE FLOW GOES MORE SOUTH/SOUTHWEST...WE MAY NOT SEE
MUCH RAIN SHOWER ACTIVITY. CERTAINLY SOMETHING TO WATCH TONIGHT.
ALSO...NO SUPPORT FOR THUNDER...ESPECIALLY SINCE PRECIPITATION MAY BE
LACKING TO BEGIN WITH. THUS...WILL PULL THUNDER CHANCES FROM TONIGHT
INTO TOMORROW. ANY THUNDER WILL LIKELY COME WITH THE COLD FRONT
TOMORROW NIGHT...BUT EVEN THERE INSTABILITY IS WEAK.
&&
.SHORT TERM...(THIS EVENING THROUGH SATURDAY NIGHT)
ISSUED AT 353 PM EST FRI JAN 2 2015
HIGH PRESSURE CONTINUES TO SIT ACROSS THE FAR EASTERN PORTION OF THE
CWA AND WILL CONTINUE TO DRIFT NORTHEASTWARD THROUGHOUT THE
AFTERNOON/EVENING. AS IT DOES...A SURFACE LOW PRESSURE SYSTEM WILL
LIFT FROM LOUISIANA AND QUICKLY NORTHEASTWARD...PULLING A QUICK
MOVING WARM FRONT ACROSS THE REGION BETWEEN 12 AND 18Z TOMORROW WITH
STRONG SOUTHERLY FLOW. THIS WILL PUT EASTERN KY IN THE WARM SECTOR
THROUGH THE REST OF SATURDAY AFTERNOON...BEFORE THE COLD FRONT SWEEPS
FROM WEST TO EAST SATURDAY NIGHT INTO SUNDAY MORNING.
MVFR CLOUD COVER HAS OVERSPREAD THE REGION IN ADVANCE OF THIS
SYSTEM...WITH ISL/SCT LIGHT RAIN CONTINUING TO SHOW UP OVER PORTIONS
OF THE STATE. EXPECT THIS RAIN TO INTENSIFY AS WE HEAD INTO THE
EVENING AND OVERNIGHT TONIGHT...AS THE WARM FRONT PUSHES NORTHWARD
AND BRINGS MOISTURE FLOW IN FROM THE SOUTH. MODEL SOUNDINGS ARE STILL
SHOWING A VERY IMPRESSIVE LOW LEVEL INVERSION DEVELOPING OVERNIGHT
WITH A MID LEVEL WARM NOSE KEEPING PRECIP WELL ABOVE FREEZING UNDER
STRONG SW FLOW. CONTINUED WITH MENTION OF THUNDER POSSIBILITIES
DURING THE LATE NIGHT AND INTO THE DAY TOMORROW AS THE WARM FRONT
MOVES THROUGH THE REGION. THE INCREASED LIFT WITH THE BOUNDARY...IN
ADDITION TO THE WARM UNSTABLE AIR...COULD LEAD TO SOME ELEVATED
CONVECTION IN THE AREA. TEMPERATURES WILL MAKE AN IMPRESSIVE JUMP
INTO THE UPPER 50S TO AROUND 60 BY TOMORROW AFTERNOON UNDER THIS
STRONG SOUTHERLY FLOW. IT IS POSSIBLE THAT WE MAY GET DRY SLOTTED IN
THE SE TOMORROW ONCE THE WARM FRONT PASSES THROUGH...AND BEFORE THE
INFLUENCE OF THE COLD FRONT...BUT KEPT IN LOWER CHANCE POPS JUST IN
CASE SOME SCATTERED CONVECTION LINGERS.
EXPECT THE WARMER TEMPS AND PRECIP CHANCES TO CONTINUE INTO THE
OVERNIGHT HOURS TOMORROW NIGHT AS THE WARM FRONT BECOMES STALLED TO
OUR NORTH AND WE AWAIT THE APPROACHING COLD FRONT...WHICH THE LATEST
GFS HAS SET TO PASS THROUGH AROUND 6Z. IT IS JUST BEFORE AND DURING
THE PASSAGE OF THE COLD FRONT THAT WE WILL LIKELY SEE OUR MOST
WIDESPREAD POPS AND HIGHEST QPF. UP TO AN INCH OF QPF COULD FALL
BETWEEN 0 AND 12Z SUNDAY...WHICH IS PRETTY CONSISTENT BETWEEN THE
LAST FEW MODEL RUNS...FORECAST PACKAGES...AND BETWEEN THE NEIGHBORING
OFFICES. IN ADDITION TO MORE WIDESPREAD RAIN...FORECAST SOUNDINGS ARE
ALSO SHOWING HEAVIER CONVECTIVE/THUNDERSTORM POTENTIAL SATURDAY
EVENING/SATURDAY NIGHT...WITH VERY STRONG LOW LEVEL WIND SHEAR AND
PRESENT ON THE LATEST NAM12 AND GFS40 FORECAST SOUNDINGS...A VERY SMALL
LOW LEVEL INVERSION...INCREASING LAPSE RATES...AND PWAT VALUES WELL
OVER AN INCH /ALMOST AN INCH AND A HALF/.
THE COLD FRONT WILL PASS THROUGH AFTER 6Z ACROSS MUCH OF THE
CWA...WITH THE BEST CONVECTIVE POTENTIAL AND HEAVIEST RAINFALL
PUSHING OUT WITH IT. HAVE POPS STARTING TO TAPER DOWN FROM DEFINITE
TO CHANCES DURING THE LAST 6 HOURS OF THE SHORT TERM FORECAST
PERIOD. FORECAST SOUNDINGS ARE SHOWING A FAST INTRUSION OF DRY AIR
IN THE MID AND UPPER LEVELS...SO EXPECT PRECIP RATES TO DIMINISH
QUICKLY BY DAWN. A LINGERING THUNDERSTORM WILL STILL BE A
POSSIBILITY...THOUGH IT SHOULD BE IN A WEAKENING/DYING STATE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 306 PM EST FRI JAN 2 2015
THE EXTENDED PERIOD BEGINS WARM AND WET ON SUNDAY MORNING JANUARY
THE FOURTH. A LARGE SWATH OF LIGHT TO MODERATE RAIN IS PROGGED TO
MOVE ACROSS THE OHIO AND TENNESSEE VALLEY REGIONS ALONG AND JUST
AHEAD OF A VERY POTENT COLD FRONT. THE RAIN IS EXPECTED TO GRADUALLY
TAPER OFF FROM WEST TO EASTERN SUNDAY AND SUNDAY NIGHT AS THE FRONT
MOVES THROUGH. THE PRECIPITATION SHOULD BE OUT OF THE AREA BY LATE
SUNDAY NIGHT. AFTER THAT...A FRIGID ARCTIC AIR MASS IS EXPECTED TO
SETTLE OVER THE REGION FOR A FEW DAYS. AFTER A MODEST COOL DOWN
SUNDAY NIGHT...DURING WHICH TIME TEMPERATURES ARE EXPECTED TO DROP
INTO THE 20S ACROSS THE AREA...A SECOND REINFORCING SHOT OF COLD AIR
IS EXPECTED TO INVADE THE AREA TUESDAY NIGHT...AS A FAST MOVING
CLIPPER SYSTEM PASSES BY JUST TO OUR NORTH. BASED ON THE LATEST MOS
GUIDANCE AND MODEL SOUNDINGS...THE MERCURY COULD DROP INTO THE TEENS
AND LOW 20S TUESDAY NIGHT...AND PERHAPS EVEN INTO THE SINGLE DIGITS
WEDNESDAY NIGHT. THE CULPRIT OF THESE FRIGID TEMPERATURES WOULD COME
IN THE FORM OF A LARGE RIDGE OF ARCTIC HIGH PRESSURE THAT IS
EXPECTED TO SETTLE OVER THE EASTERN CONUS MID WEEK. AFTER SUNDAY AND
SUNDAY NIGHT...THE ONLY PRECIPITATION THAT MAY AFFECT THE AREA WOULD
COME TUESDAY AFTERNOON AND EVENING AS THE CLIPPER SYSTEM MOVES PAST.
ANY RAIN OR SNOW THAT FALLS THAT DAY WOULD LIKELY OCCUR NORTH OF THE
MOUNTAIN PARKWAY WITH LITTLE ACCUMULATION EXPECTED. THE REST OF THE
WEEK IS FORECAST TO BE DRY AND QUITE COLD. HIGHS ON WEDNESDAY AND
THURSDAY MAY NOT CLIMB OUT OF THE 20S. MONDAY LOOKS TO BE PRETTY
COLD AS WELL...WITH HIGHS IN THE 30S ANTICIPATED ON THAT DAY.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 100 AM EST SAT JAN 3 2015
SOUTH-SOUTHEAST FLOW AHEAD OF AN APPROACHING WARM FRONT WILL
STRENGTHEN OVERNIGHT AS IT PUSHES NORTHWARD. THIS WILL YIELD SOME
DOWNSLOPING FLOW OFF THE HIGHER TERRAIN ACROSS FAR EASTERN KENTUCKY.
THIS SHOULD HELP KEEP CIGS A BIT HIGHER THROUGH THE NIGHT...OVER THE
EASTERN PARTS OF THE FORECAST AREA. THE BEST CHANCES FOR PERIODS OF
MVFR CIGS WILL BE ACROSS SOUTH-CENTRAL KENTUCKY...WHICH WILL BE LESS
INFLUENCED BY THIS DOWNSLOPING FLOW. WHILE SPRINKLES AND LIGHT RAIN
SHOWERS WILL BE AROUND OVERNIGHT...THE BEST RAIN CHANCES SHOULD HOLD
OFF UNTIL LATER SATURDAY MORNING. ACCORDINGLY...MAINLY VFR
CONDITIONS SHOULD PREVAIL FOR THE EASTERN TAF SITES. MAIN AVIATION
CONCERN WILL BE DEVELOPING LLWS LATE TONIGHT AND TOMORROW AS WINDS
STRENGTHEN JUST OFF THE SURFACE TO BETWEEN 40 AND 45 KNOTS. THIS WILL
LIKELY PERSIST THROUGH AT LEAST THE MORNING AS THE INVERSION HOLDS
TOUGH. DO EXPECT SOME MIXING OF THE GUSTS TO THE SFC SATURDAY
AFTERNOON WITH SOME BREAKS IN THE SKY COVER POSSIBLE ONCE WE ARE IN
THE DEVELOPING SYSTEM/S WARM SECTOR. CANNOT RULE OUT A STRAY
THUNDERSTORM FOR SATURDAY AFTERNOON BUT FOR NOW HAVE LEFT THEM OUT OF
THE TAFS.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...JMW
LONG TERM...AR
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
118 AM EST SAT JAN 3 2015
.SYNOPSIS...
A STORM SYSTEM WILL BRING A BRIEF WINTRY MIX EARLY SATURDAY FOLLOWED
BY RAIN THROUGH SATURDAY NIGHT.
&&
.NEAR TERM /THROUGH TODAY/...
OVERNIGHT UPDATE TO ADJUST POPS AND PRECIP TYPE BASED ON LATEST
RADAR TRENDS. WILL ISSUE AN SPS FOR COUNTIES OUTSIDE OF ADVISORIES
FOR A BRIEF PERIOD OF FREEZING RAIN AT THE ONSET OF PRECIP THIS
MORNING. NO OTHER CHANGES.
NO WHOLE-SALE CHANGES MADE TO THE OVERALL FORECAST AS PROGRESSION
OF THE SYSTEM AND FZRA THREAT REMAINS ON TRACK. SOME OF THE
NOTEWORTHY UPDATES INCLUDE CUTTING BACK ON SKY IN THE VERY NEAR
TERM AS THE THICKER CLOUD COVER TO OUR SOUTH HAS STALLED OVER
WV...LEAVING ONLY THIN HIGH CLOUDS STREAMING THROUGH THE FORECAST
AREA. LESS CLOUDS HAS RESULTED IN A GENERAL LOWERING OF INITIAL
TEMPS NOW THROUGH ABOUT 06Z AS THE THIN VEIL OF HIGH CLOUDS HAS
NOT BEEN ENOUGH TO QUELL THE ONSET OF RADIATIONAL COOLING. TEMPS
ARE DOWN A FEW DEGREES ACROSS THE BOARD FROM EARLIER
PROJECTIONS...HOWEVER BACKING WINDS OVER THE NEXT SEVERAL HOURS
WILL BEGIN TO RAPIDLY ADVANCE THE CLOUDS AND WARMER LLVL TEMPS
INTO OUR CWA.
THE WARM FRONT WILL SPREAD PRECIPITATION FROM S TO N ACROSS THE
FORECAST AREA TONIGHT FOCUSED PRIMARILY ACROSS THE HIGHER ELEVATIONS
OF THE SE FIRST AND THEN ALONG A STRONGER WAVE THROUGH ERN OH/WRN PA
BY SAT MORNING. LOCAL HI-RES MODEL AND HRRR HAVE PRETTY GOOD HANDLE
ON SFC TEMPS THROUGH MID-MORNING SAT...HIGHLIGHTING BOTH THE WARMING
WEST OF THE RIDGES WITH THE DOWNSLOPING AND THE COLD AIR DAMMED UP
AGAINST THE ERN SLOPES OF THE RIDGES. BLENDED PREVIOUS FORECAST THAT
SIDED HEAVILY TOWARDS NAM TEMPS WITH THESE HI-RES OPTIONS...WHILE
MAKING THE NECESSARY TERRAIN ALTERATIONS NECESSARY FOR THE ERLY LLVL
FLOW SET UP. AGAIN...THIS GENERALLY KEEPS THE PREVIOUS FORECAST
GOING...BUT PROVIDES A FEW TWEAKS TRIMMING BACK FZRA POTENTIAL FROM
PIT TO JUST WEST OF THE RIDGES. ALSO HELD IN THE FZRA A LITTLE
LONGER BETWEEN THE LAUREL AND CHESTNUT RIDGES AND ERN GARRETT COUNTY
MARYLAND TO ACCOUNT FOR POOR SCOURING OF THE COLD AIR. A FEW MORE
HOURS WITH FZRA COULD MEAN PORTIONS OF GARRETT CO. COULD PUSH CLOSE
TO THE 1/4" ICE THRESHOLD REQUIRING AN ICE STORM WARNING...BUT MOST
GUIDANCE KEEPS THE HIGHER AMOUNTS OF QPF MUCH CLOSER TO THE SFC LOW
TRACKING THROUGH OHIO. DRIER AIR IN THE WARM SECTOR OF THE SYSTEM
COULD LIMIT OVERALL OUTPUT OVER THE HIGH TERRAIN. WITH FAIRLY LOW
CONFIDENCE OF EXCEEDANCE...WILL HOLD STEADY WITH CURRENT ADVISORIES.
TAX
&&
.SHORT TERM /TONIGHT THROUGH 6 PM SUNDAY/...
THE BULK OF THE RAINFALL WILL HAVE MOVED EAST OF THE FORECAST AREA
BY SUNDAY MORNING AS A COLD FRONT CROSSES THE REGION. CHANCES FOR
RAIN WILL DIMINISH THROUGH THE MORNING...WITH A BRIEF LULL IN
PRECIPITATION SUNDAY AFTERNOON BEFORE THE NEXT WAVE APPROACHES FROM
THE WEST. THE DIURNAL TEMPERATURE CYCLE WILL CONTINUE TO BE
OFFSET...WITH TEMPERATURES FALLING THROUGH THE DAY ON SUNDAY. WINDS
WILL ALSO PICK UP BEHIND THE FRONT...WITH GUSTS OVER 25 MPH AND
GUSTING UP TO 35-40 MPH IN THE HIGHEST ELEVATIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
MUCH COLDER SUNDAY NIGHT AND MONDAY AS 850MB TEMPS WILL
RANGE FROM -16C TO -20C BY LATE DAY MONDAY WITH SCATTERED SNOW
SHOWERS MAINLY RIDGES AND I-80 CORRIDOR. LOW INVERSION HEIGHTS AND
WESTERLY FLOW WILL LIMIT ANY ACCUMULATIONS.
INDIVIDUAL DISTURBANCES ARE PROGGED TO ADVN THRU THE BASE OF
PERSISTENT ERN CONUS TROFG THRU THE PD WITH PERIODIC CHCS FOR SNW
SHWRS. THE STRONGEST WAVE IS PROGGED FOR A TUE PASSAGE. TEMPS ARND
10 DEG BLO AVG ARE EXPD TO START...WITH READINGS 15 TO 20 DEG BLO
AVG AFT THE TUE SHRTWV PASSAGE.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
VFR CONDITIONS THROUGH MUCH OF THE NIGHT BEFORE QUICKLY DROPPING TO
MVFR THEN IFR FROM SOUTHWEST TO NORTHEAST AS DAWN APPROACHES.
SURFACE TEMPS WILL BE THE MOST CRITICAL PART OF FORECAST EARLY ON.
IT WILL BE A RACE BETWEEN THE WARMER AIR AND THE INCOMING RAIN.
THINK MOST SITES WILL START AS AN HOUR OR TWO OF FZRA. THIS WILL
TRANSITION TO PLAIN RA DURING THE MORNING EXCEPT AT THE NORTHERN
SITES...KFKL AND KDUJ WILL BE LAST TO FULLY TRANSITION TO RAIN...NOT
UNTIL SOMETIME IN THE AFTERNOON. IFR RESTRICTIONS LOOK LIKELY...
THROUGH THE REMAINDER OF THE PERIOD.
OUTLOOK.../SATURDAY THROUGH WEDNESDAY/...
WDSPRD RSTRNS AND OCNL LLWS ARE EXPD WITH WKEND LOW PRES. RSTRNS
ARE ALSO PSBL WITH A SERIES OF DISTURBANCES ERLY NXT WK.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...FREEZING RAIN ADVISORY FROM 5 AM EARLY THIS MORNING TO 7 PM
EST THIS EVENING FOR MDZ001.
OH...NONE.
PA...FREEZING RAIN ADVISORY FROM 5 AM EARLY THIS MORNING TO 2 PM
EST THIS AFTERNOON FOR PAZ007>009-013>016-022-023-074-076.
WV...FREEZING RAIN ADVISORY FROM 5 AM EARLY THIS MORNING TO 2 PM
EST THIS AFTERNOON FOR WVZ023-041.
&&
$$
AREA FORECAST DISCUSSION
NWS DETROIT/PONTIAC MI
1144 PM EST FRI JAN 2 2015
.AVIATION...
THE STORM SYSTEM LIFTING INTO THE REGION SATURDAY WILL CAUSE
PRECIPITATION TO LIFT FROM SOUTHWEST TO NORTHEAST ACROSS SE MI
DURING THE DAY...BEGINNING AROUND OR SHORTLY AFTER 12Z. THE PRECIP
IS EXPECTED TO START AS SNOW AND SLEET...THEN TRANSITION TO FREEZING
RAIN...THEN RAIN AS THE THERMAL PROFILES WARM. THERE IS STILL SOME
UNCERTAINTY WITH RESPECT TO THE TIMING OF THESE PRECIP TYPE CHANGES
ATTM. SO THERE IS LIKELY TO BE ADJUSTMENTS IN THE CHANGE OVER TIMES
DURING LATER FORECAST ISSUANCES.
FOR DTW...THE LATEST GUIDANCE STILL SUGGESTS PRECIP WILL BEGIN AT
METRO AROUND 12Z. EXPECT CONDITIONS TO WARM ENOUGH TO SUPPORT ALL
RAIN BY EARLY AFTERNOON. A LIGHT GLAZING OF ICE IS EXPECTED TO OCCUR
DURING AT LEAST THE MORNING HOURS ON SATURDAY.
//DTW THRESHOLD PROBABILITIES...
* HIGH CONFIDENCE IN PRECIPITATION STARTING OUT FROZEN
(SNOW/SLEET/FREEZING RAIN) SAT MORNING...CHANGING TO RAIN BY EARLY
AFTERNOON.
* HIGH CONFIDENCE IN CEILINGS BELOW 5000 FT AFTER 12Z SAT.
&&
.PREV DISCUSSION...ISSUED 914 PM EST FRI JAN 2 2015
UPDATE...
SATELLITE DATA IS SHOWING THE MOISTURE FLUX INTO THE LOWER OHIO
VALLEY WELL UNDERWAY WITHIN THE STREAM OF ISENTROPIC ASCENT TIED
TO THE ENTRANCE REGION OF AN UPPER JET MAX EXTENDING ACROSS LOWER
MI. THE WATER VAPOR LOOP ALSO SHOWS A MID LEVEL SHORT WAVE OVER
ERN NEBRASKA. THIS LEAD WAVE IS FORECAST TO DAMPEN AS IT LIFTS
INTO NRN LOWER MI SAT MORNING...SUSTAINING THE UPPER JET MAX OVER
LOWER MI. THE PERSISTENT ISENTROPIC UPGLIDE INTO SRN MI WILL PULL
THE DEEPER MOISTURE INTO THE AREA SAT MORNING. THE 18Z MODEL
GUIDANCE AND LATEST RAP SUGGEST PRECIP WILL OVERSPREAD THE
FORECAST AREA FROM THE SOUTH AND WEST BETWEEN 11Z AND 14Z.
DESPITE THE THICK CIRRUS DECK NOW COVERING SRN MI...TEMPS HAVE
MANAGED TO DROP OFF INTO THE MID AND UPPER 20S. DEWPOINTS HOWEVER
ARE STILL IN THE UPPER TEENS AND LOW 20S ACROSS SRN MI AND NRN
IN/NRN OH. IN LIGHT OF THE WET BULB COOLING...A PERIOD OF FROZEN
PRECIP STILL LOOKS LIKELY PRIOR TO THE CHANGE OVER TO RAIN SAT
AFTERNOON. 18Z MODEL SOUNDINGS SUGGEST PRECIP WILL BE ALL SNOW AT
THE ONSET /EVEN IN METRO DETROIT/ GIVEN THE WET BULB
COOLING...WITH A TRANSITIONS TO SLEET...FREEZING RAIN AND RAIN
DURING THE COURSE OF THE DAY AS THE ELEVATED WARM LAYER EXPANDS
NORTHWARD. OUTSIDE OF ADDING A BRIEF PERIOD OF SNOW SOUTH OF M 59
SAT MORNING...THE CURRENT FORECAST AND WINTER WEATHER ADVISORY IN
EFFECT FOR SATURDAY WILL REMAIN UNCHANGED.
PREV DISCUSSION...ISSUED 358 PM EST FRI JAN 2 2015
SHORT TERM...TONIGHT
ENOUGH SUNSHINE THIS AFTERNOON HELPED BOOST TEMPERATURES ABOVE THE
FREEZING MARK ACROSS THE MAJORITY OF SOUTHEAST MICHIGAN.
HOWEVER...WITH DEW PTS IN THE TEENS...WE ARE SET UP FOR A QUICK FALL
THIS EVENING AS WINDS GO CALM/LIGHT UNDER PARTLY CLOUDY SKIES/HIGH
CLOUDS. A GOOD SURGE OF MOISTURE/WARM ADVECTION WILL TAKE PLACE
OVERNIGHT AS SHORTWAVE OVER NEBRASKA LIFTS INTO THE WESTERN GREAT
LAKES. CLOUDS WILL QUICKLY THICKEN UP OVERNIGHT...AND WITH SURFACE
WINDS PICKING UP OUT OF THE SOUTHEAST...TEMPERATURES SHOULD BEGIN TO
SLOWLY RISE TOWARD SUNRISE. GOOD CHANCE THE BEST RADIATORS/THUMB
REGION SLIPPING INTO THE UPPER TEENS WITH PREDOMINATELY LOWER 20S
ELSEWHERE BEFORE TEMPS BEGIN THE UPWARD CLIMB. SHOULD REMAIN DRY IN
THE TONIGHT PERIOD...AS 12Z NAM INDICATING 285 K SATURATION OVER
SOUTHWEST LOWER MICHIGAN...WITH CONDENSATION PRESSURE DEFICIT STILL
AROUND 100 MB THROUGH 12Z SATURDAY OVER MUCH OF SOUTHEAST
MICHIGAN...EXCEPT ACROSS THE FAR SOUTHWEST WHERE WE WILL INCLUDE LOW
CHANCE POPS FOR A WINTRY MIX OF PRECIPITATION.
LONG TERM... SATURDAY THROUGH FRIDAY
A WINTER WEATHER ADVISORY IS IN EFFECT SATURDAY WITH INCREASED
CONFIDENCE ON A PERIOD OF MIXED PRECIPITATION OVER SE MICHIGAN.
EXPECT MOSTLY FREEZING RAIN WITH NEAR A TENTH INCH OF ICING
FROM THE OHIO BORDER UP TO THE NORTHERN SUBURBS OF DETROIT WHERE THE
M-59 CORRIDOR WILL START A GREATER MIX WITH SNOW AT THE ONSET. IT
WILL BE ALL SNOW IN FLINT...THE TRI CITIES AND NORTHERN THUMB TO
START BEFORE A TRANSITION TO SLEET AND FREEZING RAIN BY AFTERNOON.
A GENERAL 1 TO 3 INCH SNOW ACCUMULATION IS EXPECTED BUT WITH A
SUBSTANTIAL COMPONENT OF SLEET AND ABOUT A TENTH INCH OF ICING
LIKELY BEFORE SURFACE TEMPERATURE RISES ABOVE FREEZING ALL
LOCATIONS DURING MID TO LATE AFTERNOON.
A KEY FACTOR IN OBSERVATIONS TODAY IS JUST HIGH CLOUDS OVERHEAD
AFTER DISSIPATION OF THE SURFACE FRONT. THIS WILL GIVE TEMPERATURES
A HEAD START DOWN INTO THE 20S TONIGHT FOR A STARTING POINT
SATURDAY AS AND PRECIPITATION MOVES IN FROM THE SOUTH TOWARD
SUNRISE. SURFACE PRESSURE FALLS OVER THE UPPER MIDWEST...
ASSOCIATED WITH THE NORTHERN STREAM UPPER LEVEL TROUGH...COMBINED
WITH THE DEVELOPING LOW PRESSURE SYSTEM OVER THE CENTRAL PLAINS...
WILL RESULT IN MODERATE SOUTHEAST WIND OVER LOWER MICHIGAN. THIS
IS NOT SUPPORTIVE OF A CONTINUOUS RESUPPLY OF LOW LEVEL COLD AIR
BUT ALSO IS NOT IDEAL FOR A RAPID SCOURING OF THE SHALLOW SUB
FREEZING BOUNDARY LAYER AIR THAT WILL BE IN PLACE OVER SE
MICHIGAN. PRECIPITATION RATE EARLY IN THE EVENT WILL ALSO BE MORE
LIKELY TO COOL THE SURFACE LAYER THROUGH WET BULB PROCESSES BEFORE
THE MAIN SURGE OF PRECIPITATION ARRIVES DURING THE AFTERNOON AND
REALLY MOISTENS UP AND WARMS CONDITIONS ABOVE FREEZING FROM SOUTH
TO NORTH OVER THE REGION.
THE 12Z MODEL PACKAGE IS IN REASONABLE AGREEMENT ON THE EVOLUTION OF
THE LARGER SCALE FEATURES COMING TOGETHER OVER THE GREAT LAKES FOR
THIS EVENT. THE INITIAL ROUND OF FORCING FOR PRECIPITATION WILL BE
ASSOCIATED WITH MID LEVEL WARM ADVECTION/ISENTROPIC LIFT ASSOCIATED
WITH LONG WAVE HEIGHT RISES DOWNSTREAM OF THE WAVE DIGGING INTO THE
CENTRAL ROCKIES TONIGHT. THIS APPEARS SOLID IN SATELLITE IMAGERY
WITH THE ADDED BONUS OF THE COMPACT AND INTENSE CIRCULATION
EMBEDDED WITHIN THE SOUTHERN STREAM WHICH WILL LEAD THE FOUR
CORNERS SYSTEM OUT OF THE SOUTHERN PLAINS. THE LEAD WAVE WILL ADD
A LAYER OF DYNAMIC FORCING TO GO ALONG WITH THE GENERAL PATTERN OF
DEEP THETA-E ADVECTION. AT THE SAME TIME...SURFACE LOW DEVELOPMENT
OVER THE NORTHERN PLAINS AND UPPER MIDWEST WILL AUGMENT LOW LEVEL
WARM ADVECTION FORCED BY THE LARGER SCALE DOWNSTREAM RIDGE
DEVELOPMENT. MODEL SOLUTIONS THEN INDICATE BULK THICKNESS AND LOW
LEVEL TEMPERATURE FIELDS WARMING QUICKLY FROM SOUTH TO NORTH OVER
LOWER MICHIGAN LEAVING ONLY THE TRI CITIES NEAR THE RAIN/SNOW LINE
BY AFTERNOON. MODEL SOUNDINGS INDICATE ENOUGH MID LEVEL WARMING
FOR A RAPID TRANSITION THROUGH FROZEN TO LIQUID PRECIPITATION
TYPES TO SUCH AN EXTENT THAT THE DETROIT METRO AREA MAY NOT SEE
ANY SNOW EARLY IN THE EVENT. THE INITIAL MOISTURE SURGE WILL THEN
RELOAD WITH THE SOUTHERN PLAINS UPPER LOW. PRECIPITATION TYPE WILL
THEN CHANGE TO ALL RAIN AS RATES INCREASE WITH THIS FEATURE. THE
TRI CITIES WILL REMAIN CLOSEST TO THE RAIN/SNOW LINE PUSHED
FARTHER INTO NORTHERN/WESTERN LOWER BY THEN.
MUCH COLDER AIR AND STRONG WIND WILL THEN BECOME THE MAIN STORY
BY SUNDAY AS THE LOW PRESSURE SYSTEM EXITS THE REGION. LIGHT
ACCUMULATION OF SNOW IS LIKELY UNDER THE MID LEVEL DEFORMATION
PATTERN...WHICH IS STILL SUBJECT TO SOME POSITIONAL ADJUSTMENT IN
UPCOMING MODEL RUNS...BUT CURRENTLY FAVORS AN INCH OR TWO OF
ADDITIONAL SNOW ACCUMULATION MAINLY IN THE TRI CITIES TO NORTHERN
THUMB REGION.
THE FIRST CONCERN IN THE EXTENDED PERIOD WILL BE A PERIOD OF COLD
ARCTIC AIR FILTERING IN TO THE REGION IN THE BEGINNING OF NEXT WEEK.
BEHIND THE DEPARTING LOW PRESSURE SYSTEM VERY COLD AIR WILL STREAM
INTO THE GREAT LAKES REGION RESULTING IN HIGHS ON MONDAY BARELY
RISING OUT OF THE SINGLE DIGITS /15 FOR DETROIT METRO...ONLY 11 FOR
MOST OF THE REST OF THE CWA/. LOWS ON MONDAY NIGHT WILL DROP INTO
THE MIDDLE SINGLE DIGITS WITH WIND CHILL VALUES IN THE NEGATIVE
SINGLE DIGITS. TUESDAYS HIGHS WILL BE SLIGHTLY WARMER IN THE UPPER
TEENS AND LOW 20S.
THE SECOND CONCERN FOR THE EXTENDED PERIOD WILL BE THE CHANCE OF A
CLIPPER SYSTEM TO IMPACT THE CENTRAL GREAT LAKES ON TUESDAY AND
TUESDAY NIGHT. MODELS ARE FAIRLY CONSISTENT ON THIS FEATURE
HOWEVER...INCONSISTENT WITH THE TIMING AND INTENSITY. THEREFORE IT
IS TOO EARLY TO TRY TO PINPOINT SNOWFALL TOTALS AT THIS TIME.
MARINE...
WINDS BECOMING LIGHT THIS EVENING WILL SHIFT TO THE SOUTHEAST
OVERNIGHT...AS LOW PRESSURE LIFTS INTO THE OHIO VALLEY TOMORROW.
SUSTAINED WINDS UP TO 20 KNOTS OVER SOUTHERN LAKE HURON WILL PRODUCE
WAVES 4 FEET OR SLIGHTLY BETTER...WHICH SHOULD BRUSH THE NEARSHORE
WATERS ALONG THE EASTERN THUMB REGION...AND THUS HAVE ISSUED SMALL
CRAFT ADVISORIES. THE LOW OF THE OHIO VALLEY WILL THEN TRACK IN
BETWEEN THE CENTRAL AND EASTERN GREAT LAKES TOMORROW NIGHT...WITH
VERY COLD AIR FOLLOWING FOR SUNDAY AND MONDAY. NORTHWEST WINDS OF AT
LEAST 30 KNOTS ARE EXPECTED OVER LAKE HURON WITH THE DEEP
MIXING...AND GALES ARE CERTAINLY POSSIBLE LATE SUNDAY AND SUNDAY
EVENING. HAVE GONE AHEAD AND ISSUED GALE WATCH FOR THE NORTHERN TWO
THIRDS OF LAKE HURON. WITH THE COLD AIRMASS...FREEZING SPRAY WILL
LIKELY BE AN ISSUE DURING THIS TIME FRAME AS WELL.
&&
.DTX WATCHES/WARNINGS/ADVISORIES...
MI...WINTER WEATHER ADVISORY FROM 6 AM TO 6 PM EST SATURDAY FOR
MIZ047>049-053>055-060>063-068>070-075-076-082-083.
LAKE HURON...SMALL CRAFT ADVISORY FROM 7 AM TO 7 PM EST SATURDAY FOR LHZ441-442.
GALE WATCH FROM SUNDAY AFTERNOON THROUGH LATE SUNDAY NIGHT FOR
LHZ361>363.
LAKE ST CLAIR...NONE.
MICHIGAN WATERS OF LAKE ERIE...NONE.
&&
$$
AVIATION.....SC
UPDATE.......SC
SHORT TERM...SF
LONG TERM....BT/RK
MARINE.......BT
YOU CAN OBTAIN YOUR LATEST NATIONAL WEATHER SERVICE FORECASTS ONLINE
AT WWW.WEATHER.GOV/DETROIT (ALL LOWER CASE).
AREA FORECAST DISCUSSION
NWS STATE COLLEGE PA
132 AM EST SAT JAN 3 2015
.SYNOPSIS...
A DEVELOPING LOW PRESSURE SYSTEM OVER THE LOWER MISSISSIPPI
VALLEY WILL BRING A WINTRY MIX TO CENTRAL PENNSYLVANIA
SATURDAY...FOLLOWED BY RAIN SATURDAY NIGHT INTO SUNDAY. THE MAIN
STORY NEXT WEEK WILL BE MUCH COLDER TEMPERATURES WITH NO MAJOR
STORMS ON THE HORIZON.
&&
.NEAR TERM /UNTIL 1 PM THIS AFTERNOON/...
IT IS ALREADY STARTING TO RAIN VERY LIGHTLY IN CENTRAL WV. THE
CORRESPONDING RADAR ECHOES SEEM TO BE SLIDING MORE EAST THAN NORTH
AT THIS POINT AND THE HRRR AND RUC /AND NAM/ HAVE A GOOD HANDLE ON
THE CURRENT SITUATION. WILL FOLLOW THAT GUIDANCE TRIO AND KEEP
POPS OUT UNTIL AFTER 09Z...THEN TRY TO PAINT A GRADUAL SPREAD TO
THE NE OF ABOUT 35 MPH. THE PRECIP DOES LOOK TO BE VERY LIGHT AT
ONSET AND THEREFORE THE INITIAL P-TYPE WILL BE A MIX OF JUST
ABOUT ANYTHING MADE OF WATER LESS THAN 100C. MOST LIKELY THE
PRECIP WILL BE FALLING THRU A 4-5KFT DEEP LAYER BELOW FZG...AND
SLEET OR SNOW WILL DOMINATE THE FIRST COUPLE OF HOURS ON THE
LEADING EDGE OF THE PRECIP. THE HEAVIER SHOT OF PRECIP THRU NOON
SEEMS TO BE ACROSS THE NWRN MTS...AND ONLY LIGHT AND SPOTTY PRECIP
IS EXPECTED S/E OF UNV AND SEG. MOST LOCATIONS WILL SEE SOMETHING
FALLING FROM THE SKY WHICH...WHEN PROPERLY HEATED...WOULD MELT TO
WATER.
&&
.SHORT TERM /1 PM THIS AFTERNOON THROUGH 6 PM SUNDAY/...
PTYPES/ONSET/DURATION REMAIN THE MOST CHALLENGING PART OF THE
FCST BUT THE OVERALL SET-UP IS FAVORABLE FOR A WINTRY MIX
TRANSITIONING TO MAINLY RAIN BY SATURDAY NIGHT. A CONSENSUS OF MDL
SOUNDINGS SEEM TO FAVOR ZR/IP AS THE DOMINANT PTYPES. ZR IS OF
MOST CONCERN IN THE WESTERN MTNS WHERE ICE ACCUMULATIONS MAY
NEAR 0.25 INCHES. THIS IS SUPPORTED BY THE 09Z SREF MEAN AND
INTERNAL WWD. THE QPF FOR THIS EVENT /0.50 TO 1.00 INCH/ ALSO
POSES THE RISK FOR HIGHER AMTS OF WINTRY PCPN. THE 18Z NAM AND 12Z
ECMWF ARE SUGGESTING A POCKET OF SUBFREEZING AIR AT 850MB HOLDS ON
LONGER OVER THE ERN ZONES WHICH COULD MAKE FOR A LITTLE MORE
SNOW/SLEET. FCST CALLS FOR A GENERAL 0.10 TO 0.25 OF ICE FCST FOR
THE INTERIOR CENTRAL MOUNTAINS TAPERING TO JUST A FEW HUNDREDTHS
OF AN INCH IN THE LWR SUSQ VLY. SNOW/SLEET AMOUNTS ARE 0.5-1.0
INCH OVER THE NCENTRL AND NERN ZONES BY COULD BE A LITTLE LIGHT AS
STUBBORN LLVL COLD AIR DAMMING AND EVAP COOLING SLOW WARMING
ALOFT. THE THERMAL GRADIENT ALOFT LOOKS RATHER IMPRESSIVE WITH
+10C AT 850MB IN SW PA BY 00Z SUN.
THE TAKEAWAY MESSAGE IS TO PREPARE FOR A SIGNIFICANT BUT NOT
UNCOMMON WINTER WEATHER EVENT TO AFFECT MUCH OF THE AREA DURING
THE DAYLIGHT HOURS WITH PRIMARY IMPACTS RELATED TO TRAVEL. SFC
TEMPS WILL SLOWLY CREEP ABOVE FREEZING SATURDAY EVENING/NIGHT
WITH LINGERING -ZR CHANGING TO RAIN EXPECTED IN MOST AREAS INTO
SUNDAY. PRECIP MAY BECOME LITTLE MORE THAN DRIZZLE ACROSS THE FAR
SOUTHERN TIER. STRONG COLD FRONT SHOULD BE CROSSING THE PA/OH
BORDER BY 12Z SUNDAY.
&&
.LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...
LOOKING AT MAINLY RAIN SHOWERS ON SUNDAY...GIVEN VERY STRONG SW
FLOW. 850 MB TEMPS ABOVE 10 DEGREES.
IT WILL BE WINDY...BUT NOT WARNING LEVELS. LEFT THUNDER OUT. 500
MB HEIGHT FALLS NOT THAT SIG. THUS NOT CONCERNED ABOUT
THUNDER...ESPECIALLY SEVERE.
SOME SNOW SHOWERS SUNDAY NIGHT INTO MONDAY...BUT MAINLY ACROSS
THE MOUNTAINS.
FAST MOVING CLIPPER FOR LATE TUE INTO EARLY WED MORNING. SOME
LIGHT SNOW POSSIBLE.
MAIN THING FOR WED INTO THU WILL BE A N TO NE FLOW OF MUCH COLDER
AIR...SOME CROSS POLAR FLOW. SINCE WINDS WILL BE N TO NE EARLY
ON...THE EDGE OF MUCH COLDER AIR CAN WORK TO THE SOUTH AND NOT BE
MODIFIED MUCH BY THE LAKES. SOME DIRECTIONAL SHEAR EARLY ON...BUT
SIGNIFICANT LAKE EFFECT WILL BE POSSIBLE AS WINDS SHIFT MORE TO
THE NW. STILL NOT AS COLD AS WHAT WE SAW IN EARLY JANUARY LAST
YEAR. COLDEST AIR REMAINS NORTH OF THE LOWER LAKES WITH SECONDARY
HIGH PRESSURE OVER ONTARIO AND QUEBEC. MAIN CHANGE WAS TO EDGE
TEMPS DOWN A LITTLE.
MORE IN THE WAY OF NORMAL TEMPS WILL WORK BACK IN BY LATE NEXT
WEEK...AS WINDS SHIFT MORE TO THE SW.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
CONDITIONS ACROSS THE REGION GENERALLY VFR...EXCEPT FOR SOME
LINGERING MVFR CIGS IN THE FAR NORTHWEST INCLUDING KBFD. EXPECT
THESE CIGS TO SLOWLY BREAK TO SCATTERED BY 06Z.
VFR FOR MUCH OF THE OVERNIGHT...BUT CONDITIONS WILL DETERIORATE
RAPIDLY FROM SOUTH TO NORTH BEGINNING AROUND 11Z....AS
DEVELOPING LOW PRESSURE OVER THE MIDWEST SPREADS MIXED
PRECIPITATION ACROSS THE AIRSPACE. HIGH CONFIDENCE IN REDUCED
CONDITIONS TO IFR SATURDAY AND SATURDAY NIGHT AS PRECIPITATION
TRANSITIONS TO PLAIN RAIN/DZ/FOG. MILDER AIR WILL SUPPORT SHOWERS
AHEAD OF A COLD FRONT ON SUNDAY FOLLOWED BY A COLDER NORTHWEST
FLOW SUNDAY NIGHT INTO MONDAY.
EXPECT TYPICAL OROGRAPHIC SNOW SHOWERS AND REDUCED VISIBILITIES IN
THE MOUNTAINS LATER SUNDAY INTO MONDAY.
A CLIPPER SYSTEM WILL BRING A ROUND OF LIGHT SNOW TO THE REGION
TUESDAY...FOLLOWED BY MORE SNOW SHOWERS FOR THE MOUNTAINS
WEDNESDAY.
OUTLOOK...
SUN...VARIABLE CONDITIONS...WITH MVFR CIGS AND VSBYS AT TIMES WITH
SHOWERS AND COLD FRONTAL PASSAGE.
MON...VFR CENTRAL AND SOUTH...WITH AREAS MVFR IN -SHSN WEST AND
NORTH.
TUE...CHC OF LIGHT SNOW...ESPECIALLY NORTH AND WEST.
WED...CHC OF SNOW SHOWERS NORTH AND WEST. WINDY.
&&
.CTP WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 10 AM THIS MORNING TO 5 PM EST
THIS AFTERNOON FOR PAZ004>006-010>012-037-041-042-045-046.
WINTER WEATHER ADVISORY FROM 7 AM THIS MORNING TO 5 PM EST
THIS AFTERNOON FOR PAZ017>019-024>028-033>036-049>053-056>059-
063>066.
&&
$$
SYNOPSIS...DANGELO
NEAR TERM...DANGELO
SHORT TERM...STEINBUGL
LONG TERM...MARTIN
AVIATION...JUNG
AREA FORECAST DISCUSSION
NWS HOUSTON/GALVESTON TX
1131 PM CST FRI JAN 2 2015
.AVIATION...
STILL EXPECTING MOSTLY IFR/LIFR CEILINGS AND VISIBILITIES ALONG WITH
INCREASING RA COVERAGE (AND SOME EMBEDDED SHRA/TSRA) ACROSS MUCH OF
THE AREA OVERNIGHT. THERE COULD BE BRIEF PERIODS OF IMPROVED CONDITIONS...
BUT SIGNIFICANT IMPROVEMENT SHOULD NOT OCCUR UNTIL LATE TOMORROW
MORNING OUT WEST (CLL AREA) AND DURING THE AFTERNOON HOURS TOWARD
THE EAST AS THIS STORM SYSTEM MOVES OFF TO THE EAST. 42
&&
.PREV DISCUSSION... /ISSUED 937 PM CST FRI JAN 2 2015/
UPDATE...
WARM FRONT REMAINS DRAPED ALONG THE COAST THIS EVENING FROM JUST
SOUTH OF PALACIOS TO GALVESTON TO BEAUMONT. ASIDE FROM A WIND
SHIFT THIS BOUNDARY IS ALSO APPARENT DUE TO THE 10 DEGREE
DIFFERENCE IN DEWPOINT BETWEEN ANGLETON AND GALVESTON. AREA OF
SHOWERS AND THUNDERSTORMS THAT PASSED THROUGH THE METRO AREA
EARLIER THIS EVENING CONTINUES TO PUSH OFF TO THE NORTH WITH ONLY
ISOLATED SHOWERS ACROSS THE SOUTHERN HALF OF OUR AREA AT THE
MOMENT. EXPECTING THIS SLIGHT BREAK IN THE ACTIVITY TO CONTINUE THIS
EVENING BEFORE COVERAGE PICKS UP AGAIN AFTER MIDNIGHT AS ANOTHER
WEAK DISTURBANCE APPROACHES THE REGION. PRECIP FORECAST LOOKS TO
BE IN GOOD SHAPE THIS EVENING AND ONLY CHANGES WERE SOME
ADJUSTMENTS TO TEMPERATURES AND DEWPOINTS TO REFLECT THE POSITION
OF THE WARM FRONT. 38
PREV DISCUSSION... /ISSUED 345 PM CST FRI JAN 2 2015/
DISCUSSION...
A WARM FRONT OVER THE WATERS THIS MORNING HAS CONTINUED TO PUSH
NORTH AND HAS STARTED TO MOVE INLAND. THIS HAS ALLOWED DENSE SEA
FOG TO START TO MOVE INLAND AS WELL. DUE TO THIS HAVE EXTENDED
THE DENSE FOG ADVISORY UNTIL 6 AM TOMORROW MORNING AND HAVE ALSO
ADDED BRAZORIA... CHAMBERS...HARRIS... AND LIBERTY COUNTIES.
GFS... EURO... AND CANADIAN ARE ALL IN AGREEMENT WITH RAIN
CHANCES INCREASING STARTING AFTER MIDNIGHT TONIGHT INTO SATURDAY
MORNING. JET DYNAMICS AGAIN LOOK PRETTY GOOD WITH SOUTHEAST TEXAS
BEING IN A RRQ AND LFQ. FORECAST SOUNDINGS FOR THE GFS AND NAM
BOTH SHOW K INDEX VALUES AROUND 37 EARLY TOMORROW MORNING WITH
PWATS RANGING FROM 1.45 TO AROUND 1.60" (AROUND TO JUST UNDER +2
SD FOR THIS TIME OF YEAR). HIGH RES RAP HAS PERFORMED THE BEST
TODAY AND DOES NOT HAVE THAT IMPRESSIVE OF RAINFALL TOTALS FOR
TOMORROW MORNING WHILE THE NAM AND EURO HAVE AROUND 0.5" TO 1.50"
TOTAL FOR THE EVENT. THE STRONG UPPER LIFT IS HARD TO IGNORE AND
WILL GO WITH GFS/ EURO CONSENSUS ON RAINFALL TOTALS. THE HIGHEST
PRECIP TOTALS DUE APPEAR TO BE TOWARDS PORT AUTHOR THOUGH.
THE RAIN WILL MOVE OUT OF THE AREA SATURDAY WITH CLEARING SKIES
BEHIND IT. A STRONGER ARCTIC FRONT WILL THEN MOVE THROUGH THE AREA
SUNDAY MORNING. AHEAD OF THE FRONT SOME PATCHY FOG CAN BE EXPECTED
AS WINDS WEAKEN AND SKIES GO MOSTLY CLEAR. DEWPOINT DEPRESSION
FIELD FROM THE NAM SUPPORTS THIS. AT THE SAME TIME AN UPPER LEVEL
LOW WILL FORM OVER THE BAJA OF CALIFORNIA AND BEGIN TO RETROGRADE.
THE LOW WILL THEN MOVE UNDERNEATH A RIDGE OF HIGH PRESSURE FORMING
A REX BLOCK. THE CANADIAN AND EURO ARE AGAIN IN GOOD AGREEMENT
HERE. THE GFS CONTINUES TO TREND TOWARDS THE CANADIAN/ EURO
SOLUTION. THE EURO THEN BRINGS A MUCH STRONGER FRONT THROUGH THE
AREA EARLY WEDNESDAY. THE EURO AND CANADIAN BRING A 1050MB HIGH
DOWN WITH A 1043 HIGH SETTLING OVER SAN ANGELO THURSDAY MORNING.
THE EURO AND CANADIAN ALMOST LOOK IDENTICAL THURSDAY MORNING.
GIVEN THE CONSISTENCY BETWEEN THE EURO AND CANADIAN HAVE TRENDED TEMPS
DOWN SLIGHTLY THURSDAY MORNING. 23
MARINE...
A WARM FRONT CONTINUES TO ENCROACH ON THE COAST AND SFC DEW PTS OVER
THE WATER HAVE WARMED INTO THE LOWER 60S. WATER TEMPS ARE IN THE
UPPER 50S AND THIS HAS LED TO SOME SEA FOG. FEEL THE THREAT FOR FOG
WILL PERSIST FOR MUCH OF THE NIGHT AND WILL EXTEND THE DENSE FOG
ADVISORY OVER THE WATER THROUGH 12Z. SCATTERED SHRA/TSRA WILL BECOME
MORE NUMEROUS TONIGHT INTO SATURDAY AS A COLD FRONT APPROACHES THE
AREA. CONVECTION WILL PROVIDE SOME MIXING FROM TIME TO TIME BUT FEEL
THE OVERALL TREND WILL FAVOR LOW VSBY IN FOG. ALTHOUGH WINDS HAVE
DIMINISHED...FEEL TIDE LEVELS WILL REMAIN SLIGHTLY ELEVATED UNTIL A
PACIFIC COLD FRONT USHERS IN AN OFFSHORE FLOW ON SATURDAY MORNING. A
SECONDARY SURGE OF COLDER AIR ON SUNDAY WILL MOVE OVER THE WARMER
GULF WATERS AND THE STRONG CONTRAST IN TEMPS WILL PROVIDE FOR A
STRONG THERMAL GRADIENT AND OFFSHORE WIND SPEEDS WILL INCREASE. AN
SCA WILL LIKELY BE REQUIRED SUNDAY AND SUNDAY NIGHT. ANOTHER FRONT
WILL CROSS THE COASTAL WATERS ON WEDNESDAY WITH ANOTHER SCA LIKELY
AT THAT TIME. 43
&&
.PRELIMINARY POINT TEMPS/POPS...
COLLEGE STATION (CLL) 43 58 38 48 29 / 100 50 0 0 0
HOUSTON (IAH) 49 60 42 53 33 / 100 60 0 0 0
GALVESTON (GLS) 59 60 47 53 40 / 90 80 10 0 0
&&
.HGX WATCHES/WARNINGS/ADVISORIES...
TX...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR THE FOLLOWING
ZONES: BRAZORIA...CHAMBERS...GALVESTON...HARRIS...LIBERTY.
GM...DENSE FOG ADVISORY UNTIL 6 AM CST SATURDAY FOR THE FOLLOWING
ZONES: GALVESTON BAY...WATERS FROM HIGH ISLAND TO FREEPORT
OUT 20 NM.
&&
$$
DISCUSSION...38
AVIATION/MARINE...42
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1238 AM EST SAT JAN 3 2015
.SYNOPSIS...
HIGH PRESSURE SHIFTS FROM THE OHIO VALLEY INTO THE MID ATLANTIC
AND NORTHEAST THROUGH THE WEEKEND. A STORM SYSTEM MOVING ACROSS
THE SOUTHERN PLAINS SENDS A WARM FRONT NORTHWARD INTO THE REGION
BY SATURDAY WITH MAINLY RAIN EXPECTED. A COLD FRONT FOLLOWS FOR
LATER SUNDAY INTO SUNDAY NIGHT FOLLOWED BY GUSTY NORTHWEST WINDS
AND A SURGE OF COLDER AIR FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH TODAY/...
AS OF 1225 AM EST SATURDAY...
BEEN SEEING LIGHT RETURNS STARTING TO CREEP INTO THE NC
MTNS/FOOTHILLS AND ALSO OVER SE WV SINCE 11 PM. HOWEVER...MOISTURE
IS STILL SLOWER IN DEEPENING AND LOOKING AT REGIONAL RADAR AND
MESOANALYSIS SHOWING BEST LIFT STILL SOUTH OF US OVER SRN NC. THE
LATEST HRRR/LOCAL WRF AND RUC DO SPREAD RAIN FURTHER NORTH
OVERNIGHT...SO ADJUSTED POPS DOWN SOME TO ACCOUNT FOR SLOWER
ARRIVAL TIME. TEMPS OVERALL RUNNING AT OR ABOVE FREEZING MOST OF
THE CWA...THOUGH SOME AREAS IN GREENBRIER/BATH ARE AT OR JUST
BELOW 32F. WITH SPOTTY SUB FREEZING TEMPS AND LESS QPF STILL NOT
SEEING AMPLE COVERAGE OF FZRA OR SLEET TO WARRANT A HEADLINE.
ACTUALLY CUT BACK ON ICE THROUGH 12Z...AS THINK NRN TONGUE OF
MOISTURE MOVING ACROSS NRN KY INTO HTS WV WILL STICK FURTHER NORTH
WHILE SMALLER AREA OF PRECIP AFFECTS THE MTNS OF SE WV AND
ALLEGHANYS.
PREVIOUS VALID DISCUSSION...
LOW LEVEL WINDS WILL START TO BACK TO SOUTHWEST THEN SOUTH
ORIENTATION AS AS UPPER LOW MOVES EAST OUT OF THE SOUTHERN
PLAINS...AND A SURFACE LOW BEGINS TO FORM NEAR THE MISSISSIPPI
DELTA. A WEDGE PATTERN WILL SET UP OVER THE EASTERN PARTS OF THE
REGION THAT WILL INTENSIFY HEADING INTO SATURDAY.
MILDER AIR IS EXPECTED TO MOVE INTO THE REGION OVERNIGHT...THUS
ALLOWING FOR THE OVERNIGHT LOW TEMPERATURES IN MOST AREAS TO OCCUR
DURING THE EVENING...WITH TEMPERATURES STEADY OR SLOWLY RISING
THROUGH SUNRISE SATURDAY. LOWS TONIGHT WILL RANGE FROM THE LOW TO
MID 30S ACROSS THE MOUNTAINS WITH A MIX OF 30S ACROSS THE
PIEDMONT. THE FOOTHILLS OF NC WILL SEE LOWS AROUND 40. HIGHS ON
SATURDAY WILL RANGE FROM THE UPPER 30S UNDER THE HEART OF THE LEE
SIDE WEDGE...TO THE LOWER 50S OUTSIDE OF THE WEDGE IN AREAS
BETWEEN BLUEFIELD WV AND RICHLANDS VA.
GUSTY CONDITIONS ARE ALSO EXPECTED TO DEVELOP OVERNIGHT AT THE
RIDGE TOPS...WITH THE HIGHEST ELEVATIONS EXPERIENCING GUSTS OF 25
TO 30 MPH BY DAYBREAK. DURING THE DAY SATURDAY...GUSTS WILL
INCREASE TO 30 TO 35 MPH AT THE HIGHEST ELEVATIONS.
ON SATURDAY...THE BULK OF THE PRECIPITATION WILL BECOME FOCUSED
NORTH OF THE AREA ALONG THE FORCING OF A DEVELOPING WARM FRONT NEAR
THE MASON-DIXON LINE. MOST OF OUR PRECIPITATION WILL BE ALONG THE
CREST OF THE BLUE RIDGE SOUTH OF ROANOKE WITH PATCHY LIGHT RAIN
ELSEWHERE.
&&
.SHORT TERM /TONIGHT THROUGH MONDAY/...
AS OF 200 PM EST FRIDAY...
DURING THE OVERNIGHT HOURS SATURDAY NIGHT/SUNDAY
MORNING...GFS/ECMWF/SREF ALL STRENGTHEN THE 850MB JET IN EXCESS OF
50+ KTS IN ADVANCE OF A STRONG COLD FRONT THAT WILL REMAIN WEST OF
OUR FORECAST AREA THROUGH 12Z SUNDAY. THIS SHOULD HELP BREAK THE
WEDGE...SURGE DEW POINTS UP...AND ALLOW TEMPS TO CLIMB DURING THE
OVERNIGHT HOURS.
AT THE BEGINNING OF THE SATURDAY NIGHT PERIOD WE MAY SEE A LULL IN
THE PRECIP AS WE FALL UNDER A WEAK DRY SLOT...BUT LATER IN THE NIGHT
STRONG THETA-E ADVECTION SHOULD HELP GENERATE PRECIP...ESPECIALLY IN
THE FAR WEST CLOSER TO THE BEST LOW LEVEL FORCING.
GFS/ECMWF/NAM/SREF ARE ALL IN GOOD AGREEMENT THAT THE COLD FRONT
EXITS OUR FORECAST AREA BY 00Z MONDAY (7 PM SUNDAY).
GFS MOS MOS FORECAST NEAR RECORD/RECORD HIGHS SUNDAY IN THE EAST
WHERE 850MB TEMPS WILL BE AOA +12C. WILL CONTINUE THE TREND OF
INCREASING HIGHS ON SUNDAY...BUT NOT TO THAT EXTREME.
WHILE INSTABILITY PARAMETERS ARE NOT AS IMPRESSIVE AS
YESTERDAY...STRONG FORCING WITH THE FRONT COULD STILL GENERATE A FEW
RUMBLES OF THUNDER IN THE FAR SOUTHEAST WHERE SPC HAS OUTLOOKED FOR
GENERAL THUNDER.
BEHIND THE FRONT...STRONG PRESSURE RISES AND 850MB WEST WINDS
GREATER THAN 50 KTS WILL BRING STRONG WINDS...ESPECIALLY TO THE
MOUNTAINS LATE SUNDAY THROUGH SUNDAY NIGHT. A LOCAL GFS MOS STUDY
SUGGESTS FORECAST WINDS AT ROA AND TNB WILL BE HIGH ENOUGH TO EXCEED
ADVISORY LEVELS. SIGNIFICANTLY INCREASED WINDS DURING THIS TIME
FRAME AND WILL BEEF UP WORDING IN THE HWO FOR THIS THREAT.
DESPITE THINNING LOW LEVEL MOISTURE SUNDAY NIGHT AND EARLY
MONDAY...COLD AIR ADVECTION SHOULD KEEP LIGHT SNOW/FLURRIES FOR THE
WESTERN SLOPES INTO MONDAY MORNING. ACCUMULATIONS IN WESTERN
GREENBRIER SHOULD BE 1" OR LESS WITH NO GREAT LAKES CONNECTION.
BLUSTERY AND COLD CONDITIONS ARE EXPECTED ON MONDAY WITH WINDS
GRADUALLY DIMINISHING AS A LARGE AREA OF HIGH PRESSURE MOVES INTO
THE EASTERN OHIO VALLEY BY 00Z TUESDAY (7 PM MONDAY). WENT BELOW
GUIDANCE VALUES FOR HIGHS ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 300 PM EST FRIDAY...
VERY COLD AND WINDY FOR MOST OF THE UPCOMING WEEK.
MODELS ARE CONSISTENT IN PROJECTING THE EXTENDED PERIOD TO BE
DOMINATED BY A PERSISTENT CUTOFF LOW DEVELOPING OVER THE SOUTHWEST
US/BAJA PENINSULA TOPPED BY A DECENT AMPLITUDE RIDGE OVER THE
PACIFIC NW...WITH NORTHERN AND SOUTHERN STREAM ENERGY COMBINING TO
KEEP THE EASTERN US UNDER THE INFLUENCE OF A BROAD TROF. AS WE HEAD
TOWARD THE END OF NEXT WEEK...THE PATTERN WILL BE SHIFTING MORE TO A
ZONAL FLOW REGIME WITH THE CUTOFF LOW OVER THE SOUTHWEST US OPENING
UP WHILE THE EASTERN TROF LIFTS NORTHEASTWARD.
TUESDAY WILL START OFF WITH HIGH PRESSURE PUSHING OFF TO OUR EAST AS
AN ALBERTA CLIPPER ZIPS BY WELL TO OUR NORTH AND SWINGS A COLD FRONT
THROUGH LATE ON TUESDAY. THIS COLD FRONT WILL OPEN THE FREEZER DOOR
AND ALLOW ARCTIC AIR TO POUR INTO THE REGION ON STRONG NORTHWEST
WINDS STARTING TUESDAY NIGHT...SETTING THE STAGE FOR VERY COLD
TEMPERATURES FOR THE MIDDLE OF THE WORKWEEK. TEMPERATURES WILL BE
PUSHING 20 DEGREES BELOW NORMAL ON BOTH WEDNESDAY AND THURSDAY...AND
THE HOWLING NORTHWEST WIND WILL BRING WIND CHILL VALUES INTO THE
SINGLE DIGITS TO BELOW ZERO FROM WEDNESDAY MORNING THROUGH FRIDAY
MORNING WITH THE HARSHEST CONDITIONS EXPECTED WEST OF THE BLUE
RIDGE. CONDITIONS WILL MODERATE...THOUGH REMAIN BELOW NORMAL...BY
FRIDAY AND INTO THE WEEKEND AS THE CORE OF THE COLD AIR PUSHES
THROUGH.
MOISTURE WILL BE QUITE LIMITED WITH THE COLD AIR BUT IT WILL NOT
TAKE MUCH TO SQUEEZE OUT SOME UPSLOPE NORTHWEST FLOW SNOW SHOWERS
WEST OF THE BLUE RIDGE. CURRENT INDICATIONS ARE THAT THE FAR WESTERN
SLOPES MAY SEE ENOUGH PERSISTENT SNOW SHOWERS FOR SOME LIGHT AND DRY
WINDBLOWN ACCUMULATIONS TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1140 PM EST FRIDAY...
CEILINGS HAD BEEN LOWERING DURING THE EVENING AND WERE MVFR OVER
THE MOUNTAINS. MVFR CEILINGS WILL EXPAND INTO KLWB/KDAN/KLYH BY
09Z/4AM.
HAVE AGAIN SLOWED DOWN THE ARRIVAL TIME OF THE RAIN FOR TONIGHT
UNTIL AFTER 08Z/2AM...BASED ON THE LATEST RADAR TRENDS AND THE
HRRR GUIDANCE. SURFACE BASED WEDGE DEVELOPS LATE TONIGHT ON THE
EASTERN SLOPES OF THE APPALACHIANS. ABOVE THIS WEDGE...LOW LEVEL
WINDS SHIFT TO THE SOUTH WITH WIND SPEEDS INCREASING TO AROUND 45
KNOTS BY 12Z/7AM OVER THE MOUNTAINS. THIS INCREASINGLY STRONG
SOUTH WIND WILL RESULT IN STRONG ISENTROPIC LIFT AND WIDESPREAD
LIGHT RAIN. HAVE ADDED EXPANDED THE LLWS INTO LATE SATURDAY.
HIGH CONFIDENCE THAT CEILINGS WILL LOWER TO IFR AS THE RAIN
BEGINS AND VISIBILITIES WILL HOLD IN THE MVFR RANGE.
A MAJORITY OF THE RAIN WILL MOVE NORTH OUT OF THE REGION BY
SATURDAY AFTERNOON. HOWEVER...CEILINGS AND VISIBILITIES WILL BE
VERY SLOW TO IMPROVE. ONLY MODERATE CONFIDENCE THAT CEILINGS WILL
LIFT BACK ABOVE 1500FT. KBLF MAY BREAK OUT OF THE WEDGE SATURDAY
NIGHT WITH WINDS BECOMING GUSTY FROM THE SOUTH TO SOUTHWEST. OTHER
TAF SITES WILL LOWER TO IFR AFTER SUNSET.
STRONG COLD FRONTAL PASSAGE ON SUNDAY. VERY GUSTY WINDS BEHIND
THE FRONT. CONDITIONS IMPROVE TO VFR ACROSS ALL BUT THE FAR
WESTERN PARTS OF THE REGION.
MONDAY INTO TUESDAY...PRIMARILY VFR CONDITIONS ACROSS THE AREA
WITH THE RETURN OF SURFACE HIGH PRESSURE...BUT TIGHT GRADIENT AT
850 MB WILL HELP MAINTAIN GUSTY CONDITIONS.
CLIPPER SYSTEM PASSES MAINLY NORTH OF THE REGION TUESDAY
AFTERNOON. EXPECT REINFORCING PUNCH OF COLDER AIR AND CONTINUED
STRONG NORTHWEST WINDS THROUGH THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...AMS/DS/WP
SHORT TERM...PH
LONG TERM...MBS
AVIATION...AMS/DS
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1145 PM EST FRI JAN 2 2015
.SYNOPSIS...
HIGH PRESSURE SHIFTS FROM THE OHIO VALLEY INTO THE MID ATLANTIC
AND NORTHEAST THROUGH THE WEEKEND. A STORM SYSTEM MOVING ACROSS
THE SOUTHERN PLAINS SENDS A WARM FRONT NORTHWARD INTO THE REGION
BY SATURDAY WITH MAINLY RAIN EXPECTED. A COLD FRONT FOLLOWS FOR
LATER SUNDAY INTO SUNDAY NIGHT FOLLOWED BY GUSTY NORTHWEST WINDS
AND A SURGE OF COLDER AIR FOR EARLY NEXT WEEK.
&&
.NEAR TERM /THROUGH SATURDAY/...
AS OF 855 PM EST FRIDAY...
SURFACE HIGH PRESSURE WAS CENTERED OVER SOUTHERN MARYLAND.
PREVAILING 85H WINDS WERE STILL FROM THE WEST BUT SPEEDS WERE
DIMINISHING AND WERE LESS THAN 25 KNOTS ON THE 00Z BLACKSBURG SOUNDING.
LOW LEVEL WINDS WILL START TO BACK TO SOUTHWEST THEN SOUTH
ORIENTATION AS AS UPPER LOW MOVES EAST OUT OF THE SOUTHERN
PLAINS...AND A SURFACE LOW BEGINS TO FORM NEAR THE MISSISSIPPI
DELTA. A WEDGE PATTERN WILL SET UP OVER THE EASTERN PARTS OF THE
REGION THAT WILL INTENSIFY HEADING INTO SATURDAY.
HAVE ADJUSTED THE ARRIVAL TIME OF THE PRECIPITATION. LOCAL WRF
SUGGESTED RAIN AS EARLY AS 10PM...BUT HRRR AND RAP GUIDANCE HELD
OFF A BULK OF THE PRECIPITATION UNTIL MIDNIGHT. A FEW POCKETS OF
SLEET ARE POSSIBLE ON THE LEADING EDGE OF THE PRECIPITATION...
GENERALLY ALONG AND NORTH OF I-64 IN WV AND VA. A LARGE EXPANSE OF
RAIN WILL SPREAD ACROSS THE AREA FROM SOUTHWEST TO NORTHEAST
BEFORE SUNRISE.
MILDER AIR IS EXPECTED TO MOVE INTO THE REGION OVERNIGHT...THUS
ALLOWING FOR THE OVERNIGHT LOW TEMPERATURES IN MOST AREAS TO OCCUR
DURING THE EVENING...WITH TEMPERATURES STEADY OR SLOWLY RISING
THROUGH SUNRISE SATURDAY. LOWS TONIGHT WILL RANGE FROM THE LOW TO
MID 30S ACROSS THE MOUNTAINS WITH A MIX OF 30S ACROSS THE
PIEDMONT. THE FOOTHILLS OF NC WILL SEE LOWS AROUND 40. HIGHS ON
SATURDAY WILL RANGE FROM THE UPPER 30S UNDER THE HEART OF THE LEE
SIDE WEDGE...TO THE LOWER 50S OUTSIDE OF THE WEDGE IN AREAS
BETWEEN BLUEFIELD WV AND RICHLANDS VA.
GUSTY CONDITIONS ARE ALSO EXPECTED TO DEVELOP OVERNIGHT AT THE
RIDGE TOPS...WITH THE HIGHEST ELEVATIONS EXPERIENCING GUSTS OF 25
TO 30 MPH BY DAYBREAK. DURING THE DAY SATURDAY...GUSTS WILL
INCREASE TO 30 TO 35 MPH AT THE HIGHEST ELEVATIONS.
ON SATURDAY...THE BULK OF THE PRECIPITATION WILL BECOME FOCUSED
NORTH OF THE AREA ALONG THE FORCING OF A DEVELOPING WARM FRONT NEAR
THE MASON-DIXON LINE. MOST OF OUR PRECIPITATION WILL BE ALONG THE
CREST OF THE BLUE RIDGE SOUTH OF ROANOKE WITH PATCHY LIGHT RAIN
ELSEWHERE.
&&
.SHORT TERM /SATURDAY NIGHT THROUGH MONDAY/...
AS OF 200 PM EST FRIDAY...
DURING THE OVERNIGHT HOURS SATURDAY NIGHT/SUNDAY
MORNING...GFS/ECMWF/SREF ALL STRENGTHEN THE 850MB JET IN EXCESS OF
50+ KTS IN ADVANCE OF A STRONG COLD FRONT THAT WILL REMAIN WEST OF
OUR FORECAST AREA THROUGH 12Z SUNDAY. THIS SHOULD HELP BREAK THE
WEDGE...SURGE DEW POINTS UP...AND ALLOW TEMPS TO CLIMB DURING THE
OVERNIGHT HOURS.
AT THE BEGINNING OF THE SATURDAY NIGHT PERIOD WE MAY SEE A LULL IN
THE PRECIP AS WE FALL UNDER A WEAK DRY SLOT...BUT LATER IN THE NIGHT
STRONG THETA-E ADVECTION SHOULD HELP GENERATE PRECIP...ESPECIALLY IN
THE FAR WEST CLOSER TO THE BEST LOW LEVEL FORCING.
GFS/ECMWF/NAM/SREF ARE ALL IN GOOD AGREEMENT THAT THE COLD FRONT
EXITS OUR FORECAST AREA BY 00Z MONDAY (7 PM SUNDAY).
GFS MOS MOS FORECAST NEAR RECORD/RECORD HIGHS SUNDAY IN THE EAST
WHERE 850MB TEMPS WILL BE AOA +12C. WILL CONTINUE THE TREND OF
INCREASING HIGHS ON SUNDAY...BUT NOT TO THAT EXTREME.
WHILE INSTABILITY PARAMETERS ARE NOT AS IMPRESSIVE AS
YESTERDAY...STRONG FORCING WITH THE FRONT COULD STILL GENERATE A FEW
RUMBLES OF THUNDER IN THE FAR SOUTHEAST WHERE SPC HAS OUTLOOKED FOR
GENERAL THUNDER.
BEHIND THE FRONT...STRONG PRESSURE RISES AND 850MB WEST WINDS
GREATER THAN 50 KTS WILL BRING STRONG WINDS...ESPECIALLY TO THE
MOUNTAINS LATE SUNDAY THROUGH SUNDAY NIGHT. A LOCAL GFS MOS STUDY
SUGGESTS FORECAST WINDS AT ROA AND TNB WILL BE HIGH ENOUGH TO EXCEED
ADVISORY LEVELS. SIGNIFICANTLY INCREASED WINDS DURING THIS TIME
FRAME AND WILL BEEF UP WORDING IN THE HWO FOR THIS THREAT.
DESPITE THINNING LOW LEVEL MOISTURE SUNDAY NIGHT AND EARLY
MONDAY...COLD AIR ADVECTION SHOULD KEEP LIGHT SNOW/FLURRIES FOR THE
WESTERN SLOPES INTO MONDAY MORNING. ACCUMULATIONS IN WESTERN
GREENBRIER SHOULD BE 1" OR LESS WITH NO GREAT LAKES CONNECTION.
BLUSTERY AND COLD CONDITIONS ARE EXPECTED ON MONDAY WITH WINDS
GRADUALLY DIMINISHING AS A LARGE AREA OF HIGH PRESSURE MOVES INTO
THE EASTERN OHIO VALLEY BY 00Z TUESDAY (7 PM MONDAY). WENT BELOW
GUIDANCE VALUES FOR HIGHS ON MONDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 300 PM EST FRIDAY...
VERY COLD AND WINDY FOR MOST OF THE UPCOMING WEEK.
MODELS ARE CONSISTENT IN PROJECTING THE EXTENDED PERIOD TO BE
DOMINATED BY A PERSISTENT CUTOFF LOW DEVELOPING OVER THE SOUTHWEST
US/BAJA PENINSULA TOPPED BY A DECENT AMPLITUDE RIDGE OVER THE
PACIFIC NW...WITH NORTHERN AND SOUTHERN STREAM ENERGY COMBINING TO
KEEP THE EASTERN US UNDER THE INFLUENCE OF A BROAD TROF. AS WE HEAD
TOWARD THE END OF NEXT WEEK...THE PATTERN WILL BE SHIFTING MORE TO A
ZONAL FLOW REGIME WITH THE CUTOFF LOW OVER THE SOUTHWEST US OPENING
UP WHILE THE EASTERN TROF LIFTS NORTHEASTWARD.
TUESDAY WILL START OFF WITH HIGH PRESSURE PUSHING OFF TO OUR EAST AS
AN ALBERTA CLIPPER ZIPS BY WELL TO OUR NORTH AND SWINGS A COLD FRONT
THROUGH LATE ON TUESDAY. THIS COLD FRONT WILL OPEN THE FREEZER DOOR
AND ALLOW ARCTIC AIR TO POUR INTO THE REGION ON STRONG NORTHWEST
WINDS STARTING TUESDAY NIGHT...SETTING THE STAGE FOR VERY COLD
TEMPERATURES FOR THE MIDDLE OF THE WORKWEEK. TEMPERATURES WILL BE
PUSHING 20 DEGREES BELOW NORMAL ON BOTH WEDNESDAY AND THURSDAY...AND
THE HOWLING NORTHWEST WIND WILL BRING WIND CHILL VALUES INTO THE
SINGLE DIGITS TO BELOW ZERO FROM WEDNESDAY MORNING THROUGH FRIDAY
MORNING WITH THE HARSHEST CONDITIONS EXPECTED WEST OF THE BLUE
RIDGE. CONDITIONS WILL MODERATE...THOUGH REMAIN BELOW NORMAL...BY
FRIDAY AND INTO THE WEEKEND AS THE CORE OF THE COLD AIR PUSHES
THROUGH.
MOISTURE WILL BE QUITE LIMITED WITH THE COLD AIR BUT IT WILL NOT
TAKE MUCH TO SQUEEZE OUT SOME UPSLOPE NORTHWEST FLOW SNOW SHOWERS
WEST OF THE BLUE RIDGE. CURRENT INDICATIONS ARE THAT THE FAR WESTERN
SLOPES MAY SEE ENOUGH PERSISTENT SNOW SHOWERS FOR SOME LIGHT AND DRY
WINDBLOWN ACCUMULATIONS TUESDAY NIGHT INTO WEDNESDAY.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1140 PM EST FRIDAY...
CEILINGS HAD BEEN LOWERING DURING THE EVENING AND WERE MVFR OVER
THE MOUNTAINS. MVFR CEILINGS WILL EXPAND INTO KLWB/KDAN/KLYH BY
09Z/4AM.
HAVE AGAIN SLOWED DOWN THE ARRIVAL TIME OF THE RAIN FOR TONIGHT
UNTIL AFTER 08Z/2AM...BASED ON THE LATEST RADAR TRENDS AND THE
HRRR GUIDANCE. SURFACE BASED WEDGE DEVELOPS LATE TONIGHT ON THE
EASTERN SLOPES OF THE APPALACHIANS. ABOVE THIS WEDGE...LOW LEVEL
WINDS SHIFT TO THE SOUTH WITH WIND SPEEDS INCREASING TO AROUND 45
KNOTS BY 12Z/7AM OVER THE MOUNTAINS. THIS INCREASINGLY STRONG
SOUTH WIND WILL RESULT IN STRONG ISENTROPIC LIFT AND WIDESPREAD
LIGHT RAIN. HAVE ADDED EXPANDED THE LLWS INTO LATE SATURDAY.
HIGH CONFIDENCE THAT CEILINGS WILL LOWER TO IFR AS THE RAIN
BEGINS AND VISIBILITIES WILL HOLD IN THE MVFR RANGE.
A MAJORITY OF THE RAIN WILL MOVE NORTH OUT OF THE REGION BY
SATURDAY AFTERNOON. HOWEVER...CEILINGS AND VISIBILITIES WILL BE
VERY SLOW TO IMPROVE. ONLY MODERATE CONFIDENCE THAT CEILINGS WILL
LIFT BACK ABOVE 1500FT. KBLF MAY BREAK OUT OF THE WEDGE SATURDAY
NIGHT WITH WINDS BECOMING GUSTY FROM THE SOUTH TO SOUTHWEST. OTHER
TAF SITES WILL LOWER TO IFR AFTER SUNSET.
STRONG COLD FRONTAL PASSAGE ON SUNDAY. VERY GUSTY WINDS BEHIND
THE FRONT. CONDITIONS IMPROVE TO VFR ACROSS ALL BUT THE FAR
WESTERN PARTS OF THE REGION.
MONDAY INTO TUESDAY...PRIMARILY VFR CONDITIONS ACROSS THE AREA
WITH THE RETURN OF SURFACE HIGH PRESSURE...BUT TIGHT GRADIENT AT
850 MB WILL HELP MAINTAIN GUSTY CONDITIONS.
CLIPPER SYSTEM PASSES MAINLY NORTH OF THE REGION TUESDAY
AFTERNOON. EXPECT REINFORCING PUNCH OF COLDER AIR AND CONTINUED
STRONG NORTHWEST WINDS THROUGH THURSDAY.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...PH
NEAR TERM...AMS/DS
SHORT TERM...PH
LONG TERM...MBS
AVIATION...AMS/DS
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
311 AM CST SAT JAN 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CST SAT JAN 3 2015
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED STRONG SHORTWAVES OVER WEST CENTRAL ALBERTA...EASTERN
WASHINGTON STATE...NORTH CENTRAL MONTANA AND OVER THE FORECAST AREA.
ALSO AN UPPER LOW WAS PRESENT OVER NEW MEXICO. MOISTURE HAS BEEN
STREAMING NORTHWARD TOWARDS THE FORECAST AREA...DUE TO A SOUTHWARD
PULL AHEAD OF BOTH THE UPPER LOW AND THE STRONG SHORTWAVE OVER THE
AREA. PRECIPITABLE WATER PER GOES ANALYSIS HAS CLIMBED TO 0.5 INCH
OVER SOUTHERN WI...AND 1 INCH ALONG I-70 IN MO AND IL. THIS
MOISTURE...COMBINED WITH ISENTROPIC LIFT AND DPVA FORCING AHEAD OF
THE SHORTWAVE OVER THE FORECAST AREA...HAS RESULTED IN SNOW ACROSS
THE SOUTHEAST HALF OR SO OF THE FORECAST AREA. THE SNOW HAS NOW
PUSHED INTO MAINLY WI...WITH SUBSIDENCE AND DRYING WORKING IN FROM
THE WEST BEHIND THE SHORTWAVE. MEANWHILE...FARTHER WEST...A SURFACE
LOW HAS DEVELOPED NEAR BISMARCK ND DOWNSTREAM OF THE MONTANA
SHORTWAVE. 925MB TEMPS AHEAD OF THE LOW ARE GENERALLY 0 TO -6C
ACROSS MUCH OF THE DAKOTAS EASTWARD INTO WI. HOWEVER...-20C TO -30C
READINGS WERE LURKING TO THE NORTH ACROSS MUCH OF SOUTHERN CANADA.
NORTHERLY WINDS BEHIND THE LOW HAS BEGUN BRINGING THIS COLD AIR
SOUTH WITH READINGS OVER NORTHERN NORTH DAKOTA NOW IN THE SINGLE
DIGITS BELOW ZERO.
TODAY CONTINUES TO LOOK MUCH QUIETER ON THE PRECIPITATION SIDE OF
THINGS...RESULTING MOSTLY FROM DECENT SUBSIDENCE AND DRYING
OCCURRING IN THE WAKE OF THE SHORTWAVE CURRENTLY CROSSING THE
FORECAST AREA. ANY LINGERING SNOW OVER WI SHOULD PUSH OFF TO THE
EAST OF THE AREA BY 15Z. ALTHOUGH WE DO LOSE ICE IN THE CLOUDS WITH
THE PASSAGE OF THE SHORTWAVE...WE ALSO LOSE THE LIFT...SO THE
POTENTIAL FOR FREEZING DRIZZLE IS FURTHER REDUCED. MOST 03.00Z
GUIDANCE IS NOW MOSTLY DRY FOR THE FORECAST AREA TODAY AND HAVE
FOLLOWED SUIT. 925MB TEMPS STAY RELATIVELY MILD TODAY...-2 TO -4C.
IF WE WERE SUNNY TODAY...HIGHS COULD POP INTO THE 40S OVER SNOW FREE
AREAS. HOWEVER...A SOUTHERLY FLOW LOOKS TO ADVECT IN LOW CLOUDS FROM
MO AND IL THROUGH THE FORECAST AREA...WHICH GET TRAPPED UNDER THE
SUBSIDENCE INVERSION. IN FACT...CANNOT RULE OUT SOME FOG THIS
MORNING OVER THE HIGHER TERRAIN. THESE CLOUDS SHOULD KEEP HIGHS IN
THE UPPER 20S TO MID 30S...COLDEST OVER SNOW PACK LOCATIONS.
NOW FOR TONIGHT...A LOT MORE IS GOING ON.
1. SNOW LOOKS LIKELY. WE SHOULD BEGIN TO SEE A SNOW BAND SET UP THIS
AFTERNOON FROM CENTRAL NEBRASKA INTO NORTHEAST MN. THIS BAND...
ASSOCIATED WITH MID LEVEL FRONTOGENESIS AND DPVA DOWNSTREAM OF THE
CURRENT MONTANA SHORTWAVE TRACKING EAST...LOOKS TO MOVE INTO THE
NORTHWEST HALF OF THE FORECAST AREA DURING THE EVENING...THEN MARCH
EAST THROUGH THE REST OF THE FORECAST AREA OVERNIGHT. MODELS ARE IN
PRETTY GOOD AGREEMENT IN PRODUCING A TOTAL OF 0.10-0.15 INCHES OF
QPF WITH THE BAND...WHICH SEEMS REASONABLE WHEN LOOKING AT THE
FORCING AND 0.3-0.4 INCHES OF PRECIPITABLE WATER. WITH SNOW RATIOS
OF 15-18 TO 1 RANGE IN THE BAND...DUE TO COLDER AIR FLOWING IN
ALLOWING FOR UPWARDS OF 100MB OF EFFECTIVE DENDRITIC GROWTH...A
SOLID 1 TO 2 INCHES SEEMS REASONABLE WITH A 3 INCH AMOUNT POSSIBLE.
2. NORTHWEST WINDS ARE GOING TO INCREASE THROUGH THE NIGHT. THIS IN
RESPONSE TO THE UPPER LOW EJECTING OUT OF NEW MEXICO AND PHASING
WITH THE SHORTWAVE COMING THROUGH THE FORECAST AREA TONIGHT...
RESULTING IN A DEEPENING SURFACE LOW LIFTING INTO THE EASTERN GREAT
LAKES. 925MB WINDS INCREASE TO 35-40 KT BY 12Z SUNDAY...WHICH WITH
PRESSURES RISING RAPIDLY AS THOSE WINDS DRIVE IN COLDER AIR...A GOOD
AMOUNT OF THIS WIND SHOULD MIX DOWN. 20-25 KT WINDS FROM MAV
GUIDANCE OVER THE HIGHER TERRAIN OF SOUTHEAST MN/NORTHEAST IA SEEMS
REASONABLE...WITH GUSTS OF 30-35 KT. GIVEN THE FLUFFIER SNOW
TONIGHT...SOME BLOWING AND DRIFTING IS LIKELY WITH THESE WINDS
COMING THROUGH.
3. TEMPERATURES AND WIND CHILLS PLUMMETING OVERNIGHT. 925MB TEMPS
TANK FROM THE -2 TO -4C AT 00Z TO -10 TO -20C BY 12Z...COLDEST
NORTHWEST. THIS SHOULD DROP TEMPERATURES INTO THE SINGLE DIGITS AND
TEENS...AND EVEN BELOW ZERO IN SOME OF SOUTHEAST MN BY SUNRISE. WIND
CHILLS COULD BE APPROACHING ADVISORY CRITERIA BY 12Z SUNDAY IN
PORTIONS OF SOUTHEAST MN.
HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE WESTERN PORTIONS OF
SOUTHEAST MN AND NORTHEAST IA...FROM 06-12Z SUNDAY...TO HANDLE THE
NEAR ADVISORY WINDS...FALLING SNOW...WIND CHILLS APPROACHING
ADVISORY CRITERIA AND BLOWING/DRIFTING SNOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 311 AM CST SAT JAN 3 2015
MAIN LONG TERM FOCUSES ARE ON ARCTIC AIR AND A POSSIBLE ACCUMULATING
FLUFFY SNOW EVENT FOR MONDAY NIGHT.
THE POOL OF ARCTIC AIR SITUATED CURRENTLY ACROSS MUCH OF SOUTHERN
CANADA LOOKS TO INVADE THE REGION SUNDAY AND SUNDAY NIGHT...THANKS
TO THE SHORTWAVE OVER WEST CENTRAL ALBERTA DIGGING INTO THE REGION.
925MB TEMPS PLUMMET TO -20 TO -25C BY 00Z MONDAY ON A BRISK
NORTHWEST WIND...AND FURTHER LOWERING TO -24 TO -28C BY 12Z MONDAY.
TEMPERATURES THAT BEGAN FALLING TONIGHT WILL CONTINUE TO DO SO
THROUGH THE DAY SUNDAY AND INTO SUNDAY NIGHT. COMBINED WITH THE
BRISK NORTHWEST WIND...WIND CHILL ADVISORIES AND POSSIBLY A FEW
WARNINGS ARE GOING TO BE NECESSARY. THE ARCTIC AIR MODIFIES SOMEWHAT
ON MONDAY WITH 925MB TEMPS CLIMBING TO -18 TO -22C BY 00Z...ENOUGH
THAT WIND CHILL HAZARDS SHOULD BE ALLOWED TO END BY 20Z.
ON MONDAY NIGHT...A FAST MOVING BUT POTENT SHORTWAVE IS PROGGED TO
AFFECT THE REGION. GOOD MODEL CONSENSUS EXISTS FOR STRONG MID LEVEL
FRONTOGENESIS WITH DPVA ENHANCEMENT AND UPPER LEVEL DIVERGENCE TO
ACCOMPANY THE SHORTWAVE. QPF FORECASTS ARE IN THE 0.25-0.4 INCH
RANGE...WITH UPWARDS OF 200 MB OF EFFECTIVE DENDRITIC SNOW GROWTH.
THIS WOULD MEAN EASILY 20 TO 1 RATIOS...QUITE FLUFFY SNOW...AND
ACCUMULATIONS IN THE 4 TO 8 INCH RANGE. HOWEVER...PLACEMENT OF THE
BAND IS BECOMING A SERIOUS ISSUE AS THERE HAS BEEN A TREND FOR THE
SHORTWAVE TO TRACK FARTHER SOUTHWEST THROUGH IOWA IN THE 03.00Z
GFS/CANADIAN/ECMWF. THIS TAKES THE HEAVIER SNOW FARTHER SOUTH. SO
ITS HARD TO SAY RIGHT NOW EXACTLY HOW MUCH SNOW WE WILL SEE. AT THE
MOMENT HAVE 2 TO 5 INCHES...HIGHEST SOUTH OF I-90. EXPECT THESE
AMOUNTS TO CHANGE DUE TO BAND PLACEMENT AND INTENSITY. THE
FARTHER SOUTHWEST TREND HAS RESULTED IN LOWERED PRECIPITATION
CHANCES NORTH OF I-94.
PRECIPITATION SHOULD BE OUT OF THE AREA FOR TUESDAY...WITH MORE
ARCTIC AIR BEGINNING TO PLUNGE INTO THE REGION IN THE WAKE OF THE
SYSTEM...ESPECIALLY TUESDAY NIGHT. 925MB TEMPS TANK FROM -10 TO -16C
AT 12Z TO -16 TO -20C BY 00Z WEDNESDAY AND TO -25 TO -30C BY 12Z
WEDNESDAY. 925MB WINDS ALSO PROGGED IN THE 35-45 KT RANGE. LUCKILY
THE SOUNDING PROFILE MAY END UP BEING ISOTHERMAL TO HELP LIMIT
MIXING OF THESE STRONGER WINDS...BUT ITS GOING TO BE BRISK
NONETHELESS. MORE WIND CHILL ADVISORIES AND WARNINGS ARE LIKELY FOR
TUESDAY NIGHT INTO WEDNESDAY. ADDITIONALLY...THE WIND WILL HELP BLOW
THE RECENT FLUFFY SNOW AROUND SO ADDED SOME BLOWING SNOW.
BRIEF UPPER RIDGING DROPS DOWN OVER THE FORECAST AREA WEDNESDAY
NIGHT INTO THURSDAY...BRINGING SOMEWHAT WARMER AIR INTO THE FORECAST
AREA. HOWEVER...COMBINATION OF THE WINDS AND LINGERING ARCTIC AIR
LIKELY MEAN A CONTINUATION OF WIND CHILL HAZARDS INTO THURSDAY
MORNING. RIGHT NOW HAVE THURSDAY DRY...BUT THE WARM ADVECTION MAY BE
ENOUGH TO PRODUCE SOME LIGHT SNOW AND LATER FORECASTS COULD HAVE TO
INTRODUCE PRECIPITATION CHANCES. ANOTHER ARCTIC SURGE LOOKS POISED
TO FOLLOW FOR THURSDAY NIGHT THROUGH FRIDAY...NOT AS INTENSE AS
EARLIER ONES THIS WEEK BUT STRONG ENOUGH TO POSSIBLY NEED A FEW MORE
WIND CHILL ADVISORIES.
FINALLY...LOOKING AHEAD...THERE IS SIGNAL SHOWING UP TO BREAK OUT OF
THE ARCTIC REGIME FOR NEXT WEEKEND. IN FACT...THERE IS SIGNAL IN
BOTH THE CFS AND ECMWF TO EVEN GO BACK ABOVE NORMAL.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CST FRI JAN 2 2015
A BAND OF SNOW HAS DEVELOPED ACROSS PARTS OF NORTHEAST IOWA AND
SOUTHWEST WISCONSIN LATE THIS EVENING. THE SNOW REDUCED THE
VISIBILITY AT KOLZ TO 2 MILES BRIEFLY. THE NAM AND RAP SHOW THAT
THE 850 TO 500 MB FRONTOGENESIS ASSOCIATED WITH THIS BAND WILL
MOVE NORTHEAST INTO KLSE AROUND 03.07Z...SO LOWERED THE CEILINGS
TO MVFR AND VISIBILITIES TO 2 MILES. THIS FRONTOGENESIS THEN EXITS
THE AREA AROUND 03.11Z. SNOW ACCUMULATIONS OF A ROUND A HALF INCH
ARE EXPECTED. MEANWHILE KRST WILL MISS THE PRECIPITATION FROM THIS
BAND...BUT WILL SEE CEILINGS BECOME MVFR.
ON SATURDAY EVENING...THE LONG WAVE TROUGH WILL MOVE INTO
SOUTHEAST MINNESOTA. AS THIS OCCURS...EXPECT VISIBILITIES AT KRST
TO DROP TO 1 MILE AND CEILINGS TO BECOME IFR AROUND 04.04Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR MNZ086-087-094-095.
IA...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR IAZ008>010-018-019-029.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1140 PM CST FRI JAN 2 2015
.UPDATE...
ISSUED AT 906 PM CST FRI JAN 2 2015
STARTING TO GET REPORTS OF FLURRIES ACROSS PARTS OF IOWA. TALKED
WITH THE DES MOINES OFFICE AND THEY SAID THAT THEY WERE GETTING
FLURRIES AT BOTH THE OFFICE AND AIRPORT. THIS IS LINKED TO THE 800
TO 500 MB FRONTOGENESIS. BOTH THE LATEST RAP AND 03.00Z RAP SHOW
THAT THIS FORCING WILL MOVE IN AND INCREASE IN INTENSITY BETWEEN
BETWEEN 02.04Z AND 02.06Z ACROSS SOUTHWEST WISCONSIN AND NORTHERN
IOWA. PLAN ON MOVING THE SNOW CHANCES INTO THE AREA EARLIER AREA.
SOUNDINGS CONTINUE TO SUGGEST SNOW EARLY...AND THEN POSSIBLY
TAPERING OFF TO FREEZING DRIZZLE AS IT ENDS. THINKING THAT WE HAVE
TOO MUCH PRECIPITATION CHANCES FOR SATURDAY MORNING...SO MAY HAVE
TO ADJUST THEM LOWER OR REMOVE THEM...BUT WILL WAIT A FEW MORE
HOURS BEFORE DOING THAT.
&&
.SHORT TERM...(THIS EVENING THROUGH SUNDAY NIGHT)
ISSUED AT 321 PM CST FRI JAN 2 2015
THE MAIN CONCERNS ARE WITH THE PRECIPITATION CHANCES THROUGH THE
PERIOD.
WATER VAPOR SATELLITE THIS AFTERNOON SHOWING AN UPPER LEVEL LOW
OVER NEBRASKA. THE 02.12Z MODELS ALL IN GOOD AGREEMENT IN SHOWING
THIS LOW BECOMING AN OPEN WAVE AND LIFTING ACROSS THE REGION LATE
TONIGHT INTO SATURDAY MORNING. DESPITE THE FACT THAT THIS SYSTEM
WILL BE WEAKENING SOME AS IT COMES ACROSS...IT IS STILL EXPECTED
TO BE ABLE TO PRODUCE MODERATE TO STRONG PV ADVECTION IN THE
500-300 MB LAYER AS IT MOVES ACROSS. THE QG CONVERGENCE SHOULD BE
WEAK IN THE 850-700 MB LAYER AND THEN BECOME MODERATE IN STRENGTH
ABOVE THAT. WITH THE RAPID MOVEMENT OF THE WAVE...THE WARM AIR
ADVECTION AHEAD OF IT DOES NOT HAVE MUCH TIME TO GET GOING...BUT
STILL ENOUGH TO PRODUCE 1 TO 2 UBAR/S OF UP GLIDE ON THE 285K
ISENTROPIC SURFACE. LOW LEVEL MOISTURE IS ALREADY STARTING TO
RETURN NORTH AHEAD OF THIS SYSTEM WITH LOWER 30S DEW POINTS
SPREADING INTO NORTHERN MISSOURI. THIS MOISTURE WILL CONTINUE TO
SPREAD RAPIDLY NORTH AND SHOULD GET INTO THE EASTERN SECTIONS OF
THE FORECAST AREA OVERNIGHT. WITH THIS MOISTURE RETURN AND THE
FORCING FROM THE WAVE...EXPECT THAT THERE WILL BE LIGHT
PRECIPITATION THAT DEVELOPS AFTER MIDNIGHT AND CONTINUES INTO
EARLY SATURDAY MORNING. WITH THE INITIAL BURST OF FORCING...THE
BUFKIT SOUNDINGS SUGGEST THIS WILL BE STRONG ENOUGH TO PRODUCE
DEEP SATURATION TO ALLOW ICE TO BE IN THE CLOUDS AND FOR THE
PRECIPITATION TO START OUT AS SNOW. HOWEVER...AS THE FORCING
WEAKENS...THE SATURATION GETS SHALLOWER AND ICE IN THE CLOUDS IS
LOST AND MOST LIKELY TAKING THE PRECIPITATION OVER TO LIGHT
FREEZING DRIZZLE. THIS IS NOT EXPECTED TO LAST VERY LONG WITH JUST
A COUPLE HUNDREDTHS OF ICING POSSIBLE AND WITH SNOW AMOUNTS LESS
THAN AN INCH...NOT PLANNING TO ISSUE AN ADVISORY FOR THIS EVENT.
ONCE THIS WAVE MOVES PAST THE AREA...IT LOOKS LIKE THERE WILL BE A
PERIOD FROM SATURDAY AFTERNOON INTO THE EVENING WHERE THERE MAY
NOT BE ANY PRECIPITATION OCCURRING OR IT WOULD BE VERY LIGHT AT
BEST. IF THERE IS ANYTHING OCCURRING...IT COULD BE SOME LIGHT
FREEZING DRIZZLE WITH A SHALLOW CLOUD DEPTH AND A LACK OF ICE IN
THE CLOUDS. WILL AGAIN SHOW JUST A LITTLE BIT OF ICE ACCUMULATION
IN THESE PERIODS AS CONFIDENCE THAT THERE WILL EVEN BE ANY
PRECIPITATION OCCURRING IS PRETTY LOW.
AFTER THAT...THE PRECIPITATION CHANCES PICK UP AGAIN FOR SATURDAY
NIGHT. THE MAIN UPPER LEVEL LOW OVER THE DESERT SOUTHWEST WILL BE
LIFTING NORTHEAST ACROSS THE CENTRAL MISSISSIPPI RIVER VALLEY
TOWARD THE EASTERN GREAT LAKES. AT THE SAME TIME...A NORTHERN
STREAM SHORT WAVE TROUGH WILL BE MOVING ALONG THE CANADIAN BORDER.
THE SYSTEM COMING UP FROM THE SOUTHWEST SHOULD PRODUCE STRONG PV
ADVECTION ACROSS THE SOUTHERN PART OF THE AREA SATURDAY EVENING
WITH MODERATE PV ADVECTION ACROSS MOST OF THE AREA OVERNIGHT
SATURDAY INTO EARLY SUNDAY MORNING FROM THE NORTHERN STREAM WAVE.
THE BEST PERIOD OF QG CONVERGENCE WILL COME FROM THE SOUTHWEST
SYSTEM AND THIS IS EXPECTED TO BE WEAK TO MODERATE IN STRENGTH.
THE FRONTOGENESIS DOES NOT LOOK TO BE VERY STRONG WITH EITHER OF
THESE WAVES AND SHOULD BE CONFINED TO THE 1000-700 MB LAYER. THE
ISENTROPIC UP GLIDE AGAIN LOOKS TO BE BETWEEN 1 AND 2 UBAR/S ON
THE 285K SURFACE. THE FORCING FROM THESE TWO WAVES SHOULD ALLOW A
BAND OF DEFORMATION PRECIPITATION TO DEVELOP ON THE NORTHWEST
SIDE OF THE SURFACE LOW AS IT PASSES BY TO THE SOUTHEAST. AS THE
FORCING INCREASES AND COLDER AIR MOVES IN...THE PRECIPITATION WILL
EVENTUALLY BECOME ALL SNOW...BUT STILL SOME CONCERNS ABOUT ICE IN
THE CLOUDS FOR SATURDAY EVENING AND WILL SHOW EITHER FREEZING
DRIZZLE OR A MIX OF FREEZING AND DRIZZLE AND SNOW GOING OVER TO
ALL SNOW. THE HEAVIER PRECIPITATION AMOUNT FROM THIS SYSTEM WILL
REMAIN SOUTHEAST OF THE AREA SO GENERALLY CAN EXPECT 1 TO 2 INCHES
OF SNOW FOR MUCH OF THE AREA SATURDAY NIGHT INTO SUNDAY MORNING.
THE WINDS ON THE BACK SIDE OF THE LOW WILL INCREASE SATURDAY NIGHT
INTO SUNDAY MORNING ENOUGH TO DEFINITELY PRODUCE SOME DRIFTING
SNOW AND DEPENDING ON HOW MUCH FRESH SNOW THERE IS...SOME BLOWING
SNOW. BLOWING SNOW WAS ALREADY IN THE WESTERN SECTIONS OF THE AREA
AND INCREASED THE PROBABILITIES OF THIS AND ALSO EXPANDED THE
AREAL COVERAGE TO THE REMAINDER OF THE AREA. THESE WINDS WILL
START TO DIMINISH SOME DURING THE AFTERNOON BUT WITH THE
PLUMMETING AIR TEMPERATURES...WIND CHILL VALUES ACROSS THE WESTERN
AND NORTHERN SECTIONS WILL LIKELY BE IN THE ADVISORY RANGE FOR MUCH
OF THE DAY. BY EVENING...ADVISORY WIND CHILLS SHOULD BE OVER THE
ENTIRE AREA WITH THE POSSIBILITY OF WARNING CRITERIA BEING REACHED
IN THE NORTHERN SECTIONS FOR THE OVERNIGHT AREAS.
.LONG TERM...(MONDAY THROUGH FRIDAY)
ISSUED AT 321 PM CST FRI JAN 2 2015
THE BITTERLY COLD WIND CHILLS WILL CONTINUE INTO MONDAY MORNING
BEFORE BRIEFLY IMPROVING FOR THE AFTERNOON. ADVISORY CRITERIA FOR
THE WIND CHILLS LOOK TO BE POSSIBLE AGAIN MONDAY NIGHT ACROSS THE
NORTHERN AND WESTERN SECTIONS OF THE AREA.
THE MODELS HAVE BEEN SHOWING FOR A WHILE NOW THAT A FAST MOVING
NORTHERN STREAM SYSTEM SHOULD ZIP ACROSS THE REGION EARLY NEXT
WEEK. THERE HAS BEEN SOME TIMING DIFFERENCES BETWEEN...BUT THE
02.12Z GFS AND ECMWF LOOK TO BE CLOSER ON THIS. CURRENT
INDICATIONS ARE THAT THIS WILL BE ABLE TO PRODUCE MODERATE TO
STRONG PV ADVECTION IN THE 500-300 MB LAYER WITH STRONG AND DEEP
QG CONVERGENCE. STRONG WARM AIR ADVECTION IS INDICATED AHEAD OF
THE SURFACE LOW RESULTING IN UP TO 8 UBAR/S OF UP GLIDE ON THE
275K SURFACE. IF THESE FORCING SIGNALS REMAIN CONSISTENT...THIS
SYSTEM COULD HAVE THE POTENTIAL TO PRODUCE MORE SNOW THAN WHAT
OCCURS OVER THE WEEKEND. WITH THE COLD AIR ALREADY IN PLACE...SNOW
RATIOS SHOULD BE RATHER HIGH MAKING FOR LIGHT AND FLUFFY SNOW THAT
WOULD THEN EASILY BE MOVED AROUND BY THE STRONG WINDS THAT SHOULD
DEVELOP ON THE BACK SIDE OF THE SURFACE LOW. THE IMPACT FROM THIS
SYSTEM COULD BE GREATER THAN THE WEEKEND AND THERE IS THE
POTENTIAL FOR WINTER HEADLINES AS IT COMES THROUGH. WIND CHILLS
WILL AGAIN BECOME A CONCERN BEHIND THIS SYSTEM AND WIND CHILL
ADVISORIES WILL LIKELY BE NEEDED TUESDAY NIGHT INTO WEDNESDAY
MORNING AND AGAIN WEDNESDAY NIGHT INTO THURSDAY MORNING. WARNINGS
MAY BE NEEDED AS WELL FOR PARTS OF THE AREA TUESDAY
NIGHT/WEDNESDAY MORNING.
&&
.AVIATION...(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 1140 PM CST FRI JAN 2 2015
A BAND OF SNOW HAS DEVELOPED ACROSS PARTS OF NORTHEAST IOWA AND
SOUTHWEST WISCONSIN LATE THIS EVENING. THE SNOW REDUCED THE
VISIBILITY AT KOLZ TO 2 MILES BRIEFLY. THE NAM AND RAP SHOW THAT
THE 850 TO 500 MB FRONTOGENESIS ASSOCIATED WITH THIS BAND WILL
MOVE NORTHEAST INTO KLSE AROUND 03.07Z...SO LOWERED THE CEILINGS
TO MVFR AND VISIBILITIES TO 2 MILES. THIS FRONTOGENESIS THEN EXITS
THE AREA AROUND 03.11Z. SNOW ACCUMULATIONS OF A ROUND A HALF INCH
ARE EXPECTED. MEANWHILE KRST WILL MISS THE PRECIPITATION FROM THIS
BAND...BUT WILL SEE CEILINGS BECOME MVFR.
ON SATURDAY EVENING...THE LONG WAVE TROUGH WILL MOVE INTO
SOUTHEAST MINNESOTA. AS THIS OCCURS...EXPECT VISIBILITIES AT KRST
TO DROP TO 1 MILE AND CEILINGS TO BECOME IFR AROUND 04.04Z.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
UPDATE...BOYNE
SHORT TERM...04
LONG TERM...04
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
305 AM MST SAT JAN 3 2015
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 300 AM MST SAT JAN 3 2015
UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL MOVE
SOUTH AND SOUTHEAST THROUGH COLORADO THIS AFTERNOON AND EVENING
WITH A RETURN TO WINTER CONDITIONS. MAIN CONCERNS WILL BE SNOWFALL
POTENTIAL...BLOWING SNOW AND HAZARDOUS WINTER DRIVING CONDITIONS
ON THE PLAINS.
THE COLD FRONT HAS MOVED THROUGH PORTIONS OF NORTHEAST
WYOMING AS OF 3 AM...AND IS EXPECTED TO BE OVER THE COLORADO
BORDER AROUND 14-15Z AND THEN INTO THE DENVER AREA BETWEEN 11 AM
AND NOON. EXPECT INCREASING AND GUSTY N-NE WINDS OF 20-35KT WHICH
WILL CREATE SOME BLOWING SNOW. MOISTURE DEPTH INCREASES BEHIND
FRONT WITH UPSLOPE FLOW. THERE IS WEAK TO MODERATE LARGE SCALE
ASCENT WITH THIS SYSTEM...STRONGEST OVER THE NORTHEAST PLAINS.
LATEST MODEL RUNS ARE A BIT LESS WITH SNOWFALL BUT STILL IN THE
1-3 INCH RANGE...HIGHEST OVER THE NE PLAINS EAST OF DENVER.
DESPITE THE LOWER AMOUNTS...TRAVEL WILL BE TRICKY WITH
CONSIDERABLE BLOWING AND DRIFTING SNOW. WILL LEAVE CURRENT
ADVISORIES AS IS. THE LATEST RAP IS GENERATING HIGHER SNOWFALL
AMOUNTS NEAR THE FOOTHILLS WITH ENHANCED UPSLOPE. THIS MAY BE A
BIT OF A STRETCH BUT CERTAINLY BEARS WATCHING IN CASE ADVISORIES
ARE NEEDED FURTHER WEST.
THE STORM IS QUICK MOVING AS SNOW WILL RAPIDLY DIMINISH THIS
EVENING WITH SNOW ENDING IN SOUTHERN SECTIONS AROUND MIDNIGHT.
EXPECT CLEARING SKIES AS TEMPERATURES DROP BELOW ZERO AGAIN ON THE
PLAINS. WITH BRISK WINDS CONTINUING TONIGHT ON THE PLAINS MAY
NEED A WIND CHILL ADVISORY ON THE PLAINS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 217 AM MST SAT JAN 3 2015
STG NWLY FLOW ALOFT WILL BE OVER NRN CO FROM SUN INTO MON. CROSS-
SECTIONS SHOW SOME MOISTURE EMBEDDED IN THE FLOW HOWEVER DESPITE
FAVORABLE OROGRAPHICS INSTABILITY WILL BE POOR AS LAPSE RATES ONLY
AVERAGE AROUND 3 C/KM THRU THE PERIOD. THUS EXPECT SOME PERIODS OF
LIGHT SNOW. MEANWHILE WITH STG FLOW ALOFT THERE WILL BE SOME
POTENTIAL FOR HIGH WINDS. OVERALL LOOKS LIKE THE HIGHEST WINDS
WILL STAY MAINLY ABOVE TIMBERLINE ON SUNDAY DUE TO LACK OF MTN
WAVE. LATE SUN NIGHT INTO MON THE MTN WAVE BECOMES MORE DEFINED
WHICH MAY ALLOW FOR STG WINDS TO AFFECT AREAS IN AND NR THE
FOOTHILLS.
OVER NERN CO IT LOOKS DRY BOTH DAYS WITH MAIN PROBLEM BEING HIGH
TEMPERATURES DUE TO LINGERING SNOWPACK. ON SUN WILL KEEP HIGHS IN
THE UPPER TEENS TO LOWER 20S OVER THE FAR NERN CORNER WITH LOWER 30S
POSSIBLE AROUND DENVER. IF INVERSIONS HOLD ALONG THE SOUTH PLATTE
RIVER VALLEY THEN HIGHS MAY STRUGGLE TO GET OUT OF THE TEENS. ON
MON SUBSTANTIAL WARMING IS FCST IN THE 850-700 MB LYR AS
DOWNSLOPE FLOW OCCURS ALONG THE FRONT RANGE. AS A RESULT GUIDANCE
TEMPS SHOOT UP INTO THE LOWER TO MID 50S AROUND DENVER WITH 40S
ACROSS THE PLAINS. AT THIS POINT BELIEVE LINGERING SNOWPACK WILL
STILL ALTER HIGHS SOMEWHAT SO WILL KEEP READINGS IN THE LOWER TO
MID 40S AROUND DENVER WITH 30S ACROSS THE PLAINS.
ON TUE THE FLOW ALOFT WILL BE WNW WITH NOT MUCH MOISTURE SHOWN IN
THE CROSS-SECTIONS SO WILL ONLY MENTION A SLIGHT CHC OF SNOW IN THE
MTNS WITH DRY CONDITIONS OVER NERN CO. AS FOR HIGHS BOTH THE GFS
AND ECMWF SHOW A SURGE OF COOLER AIR AFFECTING NERN CO MON NIGHT
INTO TUE MORNING. BY TUE AFTN THE GFS SHOWS THE SHALLOW LYR OF
COOLER MIXING OUT ALONG THE FRONT RANGE WHILE THE ECMWF DOES NOT.
AS A RESULT THERE IS A 10 DEGREE DIFFERENCE IN HIGH TEMPS OVER NERN
CO. FOR NOW WILL KEEP READINGS IN THE LOWER TO MID 40S NEAR DENVER
WITH LOWER TO MID 30S OVER THE FAR NERN PLAINS.
FOR TUE NIGHT INTO WED APPEARS ANOTHER SHOT OF COLDER AIR WILL
AFFECT NERN CO AS ARCTIC HIGH PRES BUILDS INTO THE NRN AND CNTRL
PLAINS. ALTHOUGH NERN CO WILL NOT TAKE A DIRECT HIT COULD EASILY
SEE HIGHS DROP BACK INTO THE TEENS OVER THE PLAINS WITH 20S ALONG
THE FRONT RANGE. MEANWHILE CROSS-SECTIONS ARE SHOWING SOME
POTENTIAL FOR FREEZING DRIZZLE OR VERY LIGHT SNOW LATE TUE NIGHT
INTO WED MORNING OVER NERN CO. IN THE MTNS IT LOOKS DRY ON WED.
ON THU DRY WNW FLOW ALOFT WILL BE OVER THE AREA AS A SFC LEE TROUGH
DEVELOPS ALONG THE FRONT RANGE. THIS SHOULD ALLOW FOR WARMER TEMPS
WITH READINGS RISING BACK INTO THE 40S ALONG THE FRONT RANGE. OVER
THE NERN PLAINS HIGHS MAY STAY IN THE 35 TO 40 DEGREE RANGE. BY FRI
THE GFS SHOWS A WEAK UPPER LEVEL RIDGE OVER THE AREA WHILE THE ECMWF
HAS NWLY FLOW ALOFT. DESPITE THE DIFFERING UPPER LVL PATTERNS BOTH
MODELS SHOW ANOTHER SHOT OF COOLER AIR MOVING INTO NERN CO THU NIGHT
INTO EARLY FRI. THE ECMWF HAS NO PCPN OVER THE AREA WHILE THE GFS
HAS SOME LIGHT PCPN OVER NERN CO. FOR NOW WILL KEEP FCST DRY AND
HAVE HIGHS RANGING FM THE UPPER 20S OVER THE FAR NERN CORNER WITH 35
TO 40 AROUND DENVER.
&&
.AVIATION...(FOR THE TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 217 AM MST SAT JAN 3 2015
SURFACE COLD FRONT WILL MOVE ACROSS TERMINALS IN THE 17-18Z TIME
FRAME AS WINDS INCREASE FROM THE NORTH AND NORTHEAST WITH GUSTS UP
TO 30KT. SNOW WILL DEVELOP 1-2 HOURS BEHIND THE FRONT WITH
MVFR/IFR CONDITIONS DEVELOPING THIS AFTERNOON. EXPECT SNOWFALL THE
HEAVIEST BETWEEN 21Z-01Z WITH TOTAL SNOWFALL OF 1-3 INCHES. SNOW
WILL DIMINISH THIS EVENING WITH SOME CLEARING OVERNIGHT.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY FROM 11 AM THIS MORNING TO 9 PM MST THIS
EVENING FOR COZ041>051.
&&
$$
SHORT TERM...ENTREKIN
LONG TERM...RPK
AVIATION...ENTREKIN
AREA FORECAST DISCUSSION
NWS CHARLESTON SC
1055 AM EST SAT JAN 3 2015
.SYNOPSIS...
WEAK HIGH PRESSURE OVER THE AREA WILL RETREAT TONIGHT AS A WARM
FRONT LIFTS NORTH. A COLD FRONT WILL PUSH THROUGH LATE SUNDAY
FOLLOWED BY DRY HIGH PRESSURE. A SECONDARY COLD FRONT WILL DROP
THROUGH WEDNESDAY EVENING WITH COLDER HIGH PRESSURE BUILDING IN FOR
THURSDAY INTO THE WEEKEND.
&&
.NEAR TERM /THROUGH TONIGHT/...
LATE THIS MORNING...THE FORECAST FOR TODAY IS CERTAINLY COMPLEX
WITH LOTS OF SUBTLETIES THAT WILL IMPACT THE SENSIBLE ELEMENTS.
THE CURRENT SET UP FEATURES SOUTHWEST FLOW ALOFT AS THE REGION IS
PLACED BETWEEN THE UPPER LOW ENTERING THE SOUTHERN PLAINS AND THE
RIDGE IN THE VICINITY OF THE BAHAMAS. THERE ARE REALLY NO
INTERESTING FEATURES EMBEDDED WITHIN THE SOUTHWEST FLOW
ALOFT...AND THE ENVIRONMENT IS LARGELY VOID OF ANY DEEP LAYER
FORCING. AT THE SURFACE...THE COLD AIR DAMMING REGIME IS LIKELY AT
ITS PEAK OF MATURITY WITH A WELL DEVELOPED INVERTED RIDGE IN THE
LEE OF THE APPALACHIANS AS NOTED IN SURFACE ANALYSIS.
HOWEVER...THE CAD IS RELATIVELY WEAK AS NOTED IN THE 12Z KCHS
SOUNDING WITH A VERY SHALLOW LAYER UP TO ONLY ABOUT 2 KFT.
FURTHERMORE...ACROSS THE FORECAST AREA...THERE IS NOT A TREMENDOUS
TEMPERATURE GRADIENT AS CURRENT READINGS HAVE ALREADY REACHED TO
NEAR 60 AT THE COAST AND RISING INTO THE UPPER 50S JUST INLAND.
THE SOUTHERN EXTENT OF THE HEART OF THE WEDGE IS LIKELY SOMEWHERE
AROUND THE SAVANNAH RIVER AS OBSERVATION SITES SOUTH OF THE RIVER
ARE ALREADY REPORTING FLOW THAT HAS AN INCREASING EASTERLY
COMPONENT. ALL THIS IS TO SAY THAT THE WEDGE IS NOT FIRMLY
ENTRENCHED AND SHOULD BE REASONABLY EASY TO SCOUR OUT THROUGH THE
AFTERNOON. WE HAVE PROGGED THE FLOW VEERING TO MORE EASTERLY AND
SOUTHEASTERLY IN THE 18Z-21Z TIME PERIOD BASED ON THE HRRR AND
RAP. THE TRANSITION WILL TAKE LONGEST ACROSS THE TRI-COUNTY WHERE
ONGOING PRECIPITATION WILL LEAD TO SOME LOCAL DIABATIC ENHANCEMENT
AND IT MAY HANG ON IN THIS AREA A BIT LONGER.
THE ONGOING RAINFALL IS MAINLY AFFECTING THE SOUTH CAROLINA ZONES
AS IT FEEDS IN OFF THE ATLANTIC WITHIN A SHALLOW ISENTROPIC LIFT
REGIME. MODEL TIME HEIGHTS SHOW THAT THE ATMOSPHERE ABOVE 5 KFT IS
QUITE DRY SO WE ARE PRIMARILY DEALING WITH SHALLOW/WARM PRODUCTION
PROCESSES. POPS HAVE BEEN INCREASED TO LIKELY THROUGH THE EARLY
AFTERNOON FOR THE EASTERN HALF OF THE AREA WITH SLIGHT CHANCES
FURTHER WEST INCLUDING SAVANNAH. BASED ON UPSTREAM CLOUD
COVER...WE MAY EVEN SEE SOME BREAKS OF SUN...ESPECIALLY FOR
SOUTHEAST GEORGIA. GIVEN THAT TEMPERATURES ARE ALREADY SO WARM...I
HAVE RAISED HIGHS FOR TODAY 3-5 DEGREES. THE SAVANNAH AREA COULD
EVEN REACH THE MID 70S BY THE LATE AFTERNOON...DEPENDING ON HOW
MUCH SUN ACTUALLY BREAKS THROUGH.
OVERNIGHT...THE FOCUS SHIFTS TO A POTENTIAL FOR FOG AND PERHAPS
PERIODS OF DENSE FOG IN SOME LOCATIONS ALONG THE COAST AND INLAND
SE SOUTH CAROLINA. THERE IS A 30 KT LOW LEVEL JET WHICH
STRENGTHENS TO 40 KT LATE BUT SOME CLASSIC BUILD- DOWN STRATUS
SIGNATURES ARE SHOWN ON FORECAST SOUNDINGS IN THESE AREAS. AREAS
OF FOG IN THE FORECAST TONIGHT WITH PATCHY FOG INLAND SE GEORGIA.
ANOTHER FOG ISSUE MAY BE SEA FOG/STRATUS ADVECTING ONSHORE INTO
THE COAST COMPLICATING THE ALREADY COMPLEX LOW LEVEL THERMAL
ENVIRONMENT AND FORECAST FOR FOG IN SPACE AND TIME. WE CONTINUED
TO MENTION A DENSE FOG POTENTIAL TONIGHT IN THE HAZARDOUS WEATHER
OUTLOOK.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
A POTENT UPPER SHORTWAVE WILL SHIFT EAST INTO THE CENTRAL
APPALACHIANS ON SUNDAY...DRIVING A COLD FRONT INTO THE EASTERN
UNITED STATES LATE SUNDAY AFTERNOON. THE BRUNT OF THE UPPER VORT
ENERGY WILL REMAIN WELL NORTH OF THE FORECAST AREA. HOWEVER...A
ROBUST 45-50 KT 850 MB JET WILL DEVELOP ACROSS THE AREA SUNDAY
AFTERNOON...ADVECTING A WARM AND MOIST AIRMASS INTO THE AREA. SFC
DEWPOINTS ARE PROGGED TO RISE INTO THE UPPER 60S WHILE TEMPS WILL
REACH THE MID TO UPPER 70S. ATOP THE TROPOSPHERE A 180 KT JET STREAK
WILL PUSH INTO THE MID-ATLANTIC REGION DURING THE AFTERNOON...
SPREADING EXTENSIVE UPPER DIVERGENCE INTO THE SOUTHEAST STATES LATE.
A WEAK VORT WILL LIFT UP THE COAST SUNDAY MORNING...POTENTIALLY
SPURRING SCATTERED RAIN SHOWERS. HOWEVER...FOR THE MIDDLE OF THE DAY
THERE WILL NOT BE MUCH FORCING FOR PRECIPITATION SO WE ONLY SHOW
SLIGHT CHANCE POPS LATE MORNING AND EARLY AFTERNOON. THERE IS FAIRLY
GOOD MODEL AGREEMENT THAT THE FRONTAL BAND WILL PUSH INTO OUR
WESTERN ZONES MID TO LATE AFTERNOON AND SHIFT OFF THE COAST BEFORE
MIDNIGHT SUNDAY NIGHT. MOISTURE AND LIFT WILL SUPPORT LIKELY TO
CATEGORICAL POPS DURING THIS PERIOD. THE SEVERE WEATHER POTENTIAL
LOOKS MARGINAL AT BEST. AS WE OFTEN SEE IN COLD-SEASON SYNOPTIC
SCALE SYSTEMS...SHEAR PARAMETERS ARE PRETTY STRONG BUT THE
ALL-IMPORTANT SURFACE-BASED INSTABILITY WILL BE VERY LIMITED. BY THE
TIME THE FRONT MAKES ITS WAY INTO THE AREA...CAPE VALUES WILL BE
LESS THAN 500 J/KG AND LAPSE RATES WILL BE LESS THAN 6C/KM.
EXTENSIVE CLOUDINESS WILL PRECEDE THE FRONT...LIMITING THE CHANCE
THAT POCKETS OF ENHANCED SURFACE-BASED INSTABILITY WILL DEVELOP.
GIVEN THE STRONG WIND FIELDS...AN ISOLATED DAMAGING WIND GUST CANNOT
BE RULED OUT BUT AT THIS TIME WE ARE NOT ANTICIPATING MUCH SEVERE
WEATHER.
THE COLD FRONT WILL BE OFFSHORE BY MIDNIGHT...WITH WEAK HIGH
PRESSURE BUILDING IN BEHIND. DESPITE THE WEAK COLD ADVECTION...
WESTERLY FLOW IN THE LOWER LEVELS WILL SUPPORT DOWNSLOPE COMPRESSION
AND HIGH TEMPS AROUND 60F MONDAY AND TUESDAY.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
A POWERFUL UPPER TROUGH WILL DIG ACROSS THE CENTRAL AND EASTERN
UNITED STATES MID TO LATE WEEK...EVENTUALLY ALLOWING A VERY COLD
AIRMASS FROM CANADA TO DROP INTO THE SOUTHEAST UNITED STATES. AN
INITIAL WEAK COLD FRONT WILL DROP THROUGH LATE TUESDAY NIGHT...
KEEPING WEDNESDAY HIGHS IN THE MID 50S. A MUCH STRONGER COLD FRONT
WILL MOVE THROUGH WEDNESDAY EVENING...WITH STRONG COLD ADVECTION
DROPPING THURSDAY MORNING TEMPS INTO THE MIDDLE 20S. AN INTENSELY
DRY CANADIAN AIRMASS WILL SHIFT OVER THE AREA THURSDAY WITH
DEWPOINTS DROPPING INTO THE SINGLE DIGITS. GIVEN GROWING MODEL
CONSENSUS WE FURTHER DROPPED THURSDAY HIGH TEMPS...NOW SHOWING HIGHS
AROUND 40 NORTH TO MIDDLE 40S SOUTH. INTERESTINGLY...THE ECMWF
REMAINS THE COLDEST MODEL...CONTINUING TO SHOW HIGH TEMPS ONLY IN
THE MIDDLE 30S. THE HIGH WILL SETTLE OVER THE AREA THURSDAY NIGHT
WITH CLEAR SKIES AND DIMINISHING WINDS SUPPORTING A HARD FREEZE. WE
DROPPED LOWS INTO THE MID 20S INLAND FROM THE COAST...BUT THERE IS A
POTENTIAL FOR LOWS IN THE UPPER TEENS IF THE ECMWF VERIFIES. COLD
WEATHER PERSISTS FRIDAY INTO SATURDAY THOUGH A SLIGHT WARMING TREND
ENSUES AS THE HIGH SHIFTS NORTHEAST.
&&
.AVIATION /16Z SATURDAY THROUGH WEDNESDAY/...
KCHS...CIGS WILL REMAIN IFR THROUGH THE REST OF THE MORNING AS
SHOWERS STREAM IN FROM THE ATLANTIC. CEILINGS SHOULD THEN LIFT TO
MVFR THIS AFTERNOON BEFORE BUILDING DOWN AGAIN THIS EVENING AND
ESPECIALLY OVERNIGHT. THERE MAY BE A PERIOD OF FOG THIS EVENING
IF THE WEDGE IS SLOW TO SCOUR TODAY OR SEA FOG/STRATUS ADVECT
ONSHORE AT ANY POINT LATER TODAY OR TONIGHT. RAIN CHANCES LOOK
BEST THROUGH MID AFTERNOON THEN MAINLY VCSH OR PATCHY DRIZZLE
TONIGHT.
KSAV...IFR CIGS WILL LIKELY PERSIST THROUGH THE MORNING AS WARMER
AIR STREAMS OVER THE WEDGE AIR MASS AT THE SURFACE. A WARM FRONT
WILL STRUGGLE THROUGH THE TERMINAL LATER TODAY WITH SURFACE FLOW
TURNING MORE SE AND EVENTUALLY S LATE. LOW CIGS COULD EASILY HANG
IN ALL DAY BUT CONFIDENCE HIGHEST TONIGHT FOR IFR/LIFR CIGS. RAIN
CHANCES/TIMING NOT HIGH ENOUGH TO PREVAIL ANY SHOWERS.
BOTH TERMINALS COULD EXPERIENCE LOW END LLWS CONDITIONS LATE TONIGHT
OR TONIGHT.
EXTENDED AVIATION OUTLOOK...MVFR OR LOWER CEILINGS ARE LIKELY TO
PERSIST THROUGH SUNDAY EVENING. SCATTERED SHOWERS AND ISOLATED TSTMS
EXPECTED LATE SUNDAY AFTERNOON INTO THE EVENING. VFR CONDITIONS
RETURN LATE SUNDAY NIGHT.
&&
.MARINE...
THE PRES GRADIENT HAS BEEN PINCHING OVERNIGHT ALONG THE COAST NORTH
OF THE SAVANNAH RIVER ENTRANCE CLOSE TO 15 KT WITH HIGHER GUSTS AT
TIMES ALONG THE CHARLESTON COUNTY COAST. THIS GRADIENT IS FORECAST
TO WEAKEN BY MID MORNING. LIGHT WINDS TRYING TO VEER THIS AFTERNOON
BUT IT WILL BE A DIFFICULT TASK AS THE MARINE LAYER IS STABLE AND
COOL. LATEST H3R MODEL SHOWS A LIGHT AND VARIABLE WIND REGIME THIS
AFTERNOON EVENTUALLY TURNING SE AROUND DUSK ACROSS THE NEAR SHORE
WATERS. THE FLOW WILL VEER SOUTHERLY LATER TONIGHT WITH SPEEDS
INCREASING GRADUALLY. SEAS WILL BUILD TO 4-6 FT WELL OFF THE
CHARLESTON COUNTY COAST LATE AND OVER THE 20-60 NM GEORGIA WATERS
SOMETIME AFTER MIDNIGHT.
THE MAIN PROBLEM TODAY AND TONIGHT SHOULD BE THE DEVELOPMENT OF
SEA FOG AS ELEVATED MOIST DEW POINTS IN THE 60S STREAM OVER THE
MARINE LAYER. FOG IS IN THE FORECAST AND THERE ARE GOOD CHANCES
FOR MARINE FOG ADVISORIES STARTING LATER TODAY INTO TONIGHT. THE
ONSHORE TRAJECTORIES SUGGEST SEA FOG/STRATUS WILL ADVECT INTO
SOME OF OUR COASTAL AREAS INCLUDING THE CHARLESTON HARBOR.
THE WARM ADVECTION REGIME CONTINUES SUNDAY WITH STRONG SOUTHERLY
WINDS MOVING ACROSS COOL COASTAL WATERS. SMALL CRAFT CONDITIONS...
MAINLY IN 6 FT SEAS...EXPECTED OVER THE GA OFFSHORE AND CHARLESTON
SC NEARSHORE WATERS SUNDAY AND SUNDAY NIGHT. SEA FOG WILL LIKELY
REMAIN A CONCERN FOR ALL NEARSHORE AREAS INCLUDING CHARLESTON HARBOR
DUE TO MID TO UPPER 60S DEWPOINTS RESIDING OVER 50S WATER TEMPS. ANY
SEA FOG WILL BE CLEARED OUT SUNDAY NIGHT BEHIND THE COLD FRONT AS
DRIER AIR SHIFTS IN. COLD ADVECTION ON MONDAY WILL MAINTAIN SMALL
CRAFT CONDITIONS OVER THE OFFSHORE GA WATERS BEFORE CONDITIONS RELAX.
MARGINAL SMALL CRAFT CONDITIONS POSSIBLE WEDNESDAY BEHIND A WEAK
COLD FRONT. HOWEVER THE MAIN CONCERN WILL BE POSSIBLE GALES
WEDNESDAY NIGHT AND THURSDAY BEHIND A POWERFUL COLD FRONT.
GEOSTROPHIC WINDS OF 40-45 KT AND STRONG COLD ADVECTION COULD ALLOW
FOR FREQUENT 35 KT GUSTS...AT A MINIMUM OVER THE OFFSHORE GA WATERS.
WE WILL ADD MENTION TO THE HAZARDOUS WEATHER OUTLOOK.
&&
.CHS WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
SC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 4 PM EST MONDAY
FOR AMZ374.
SMALL CRAFT ADVISORY FROM MIDNIGHT TONIGHT TO 5 AM EST MONDAY
FOR AMZ350.
&&
$$
NEAR TERM...BSH
SHORT TERM...JRL
LONG TERM...JRL
AVIATION...
MARINE...JRL
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
945 AM EST SAT JAN 3 2015
.SYNOPSIS...
ISSUED AT 943 AM EST SAT JAN 3 2015
LOW PRESSURE WILL MOVE OUT OF THE SOUTHWEST TOWARDS THE SOUTHERN
GREAT LAKES SATURDAY NIGHT. AREAS OF FREEZING RAIN AND SNOW WILL
CHANGE TO ALL RAIN BY EARLY AFTERNOON AS TEMPERATURES WARM ABOVE
FREEZING. HIGHS TODAY WILL RANGE FROM THE MIDDLE 30S NORTHWEST TO
NEAR 50 IN THE SOUTHEAST.
&&
.UPDATE...
ISSUED AT 932 AM EST SAT JAN 3 2015
BY IN LARGE GRIDS IN DECENT SHAPE WITH EVENT PRETTY MUCH
UNFOLDING AS EXPECTED. REPORTS AT LOCATIONS SOUTH OF ROUTE 24
INDICATE ROADS CONTINUING TO IMPROVE AS TEMPS HOVER IN THE 32 TO
35 DEGREE RANGE. SLICK CONDITIONS STILL BEING REPORTED WITH
POCKETS OF FREEZING RAIN BETWEEN 24 AND ROUTE 6 WHERE TEMPS WERE
HOVERING IN THE 31 TO 33 DEGREE RANGE WARRANTING CONTINUATION OF
THE ADVISORY THROUGH 16Z IN THESE AREAS. FURTHER NORTH...CONDITIONS
WILL BE SLOWER TO IMPROVE BUT MAYBE NOT AS BAD AS FEARED YESTERDAY
WITH ALL OBS SITES SITTING RIGHT AT FREEZING AS OF 14Z.
HOWEVER...NO CHANGES WILL BE MADE TO END TIME OF HEADLINES AT THIS
POINT.
HAVE MADE MINOR CHANGES TO TEMPS ESPECIALLY SE WHERE READINGS ARE
ALREADY HEADING INTO THE MID TO UPR 30S. WILL TAKE ANOTHER LOOK AT
HEADLINES IN NEXT HOUR OR 2.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST SAT JAN 3 2015
IMPRESSIVE SRN STREAM SW TROUGH NOTED IN VAPOR THIS MORNING AND
BEGINNING TO LIFT OUT OF NM. THIS SYS WILL PHASE QUICKLY TONIGHT
W/NRN STREAM SW AMPLIFYING SEWD OUT OF THE NRN ROCKIES RESULTING IN
A RAPID NEWD EJECTION INTO SE CANADA BU SUN MORNING.
BROAD LOW-MID LVL MSTR SURGE JUST NOW GETTING UP INTO THE AREA
W/MORE VIGOROUS PRECIP DVLPMNT NOTED IN COMPOSITE RADAR IMAGERY BACK
ACRS CNTRL IL INTO WRN IN AND POSES AN ICING PROB EARLY ON
W/CURRENT SFC TEMPS IN THE UPR 20S. HWVR LL WAA QUITE INTENSE AS
NOTED OVR SRN IL/IN AND XPCD TO PROGRESS NWD THROUGH THIS MORNING.
GIVEN GOOD 00Z CONSENSUS W/CORRESPONDING RUC NOD TO SFC TEMPS CUT
BACK TIMING OF ADVISORY ACRS FAR SRN TIER OF COUNTIES YET WILL HOLD
W/REMAINDER OF ADVISORY SEGMENTS PER LTL XPCD SFC BASED WARMING
WILL OCCUR UNTIL MID-LT MORNING TIED TO DEEPER ERLY FLW TRAJECTORIES
AND MUCH LWR THETA-E AIR ORIGINATING FM OLD POLAR RIDGE.
REGARDLESS LL WAA WILL OVERWHELM SHALLOW SFC BASED COLD LYR BY LT
MORNING/ERLY AFTN S-N W/A DECENT RAIN EVENT XPCD ESP SE HALF. MID
LVL DRY SLOT WILL OVERSPREAD AREA LT THIS AFTN WEST AND OVERNIGHT
EAST ALTHOUGH TEMPS WILL FAIRLY MILD. EXCEPTION WILL BE FAR WEST
WHERE INTENSE LL CAA WING WILL BEGIN TO WRAP SEWD BEHIND DEPARTING
SFC LOW. LEFT OVER DEFORMATION ZONE AND RAPID INFLUX OF COLD AIR
WILL LEAD TO A RAPID CHG OVR TO ACCUMULATING SNOW FAR NW AND
EXPANDING SEWD DURING THE DAY AS MSTR FLUX OFF LK MI TAKES OFF. SHLD
SEE A PD OF ROBUST LK ENHANCEMENT THROUGHOUT THE NW HALF SUN AFTN
W/AT LEAST AN INCH OR TWO OF SNOWFALL XPCD.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 403 AM EST SAT JAN 3 2015
BITTERLY COLD CONDITIONS CAN BE EXPECTED FOR MUCH OF THE LONG TERM
FORECAST DURING THE UPCOMING WEEK. STRONG COLD AIR ADVECTION WILL BE
OCCURRING AT THE START OF THIS PERIOD SUNDAY NIGHT. A STRONG UPPER
LEVEL DISTURBANCE WILL SUPPORT THE DEVELOPMENT OF A CLIPPER TYPE
SYSTEM THAT SHOULD RACE ACROSS THE AREA MONDAY NIGHT INTO EARLY
TUESDAY. FAVORED THE ECMWF RUN TO RUN CONSISTENCY AND HANDLING OF
THIS SYSTEM. TEMPERATURES WILL BE COLD ENOUGH FOR ALL SNOW...WITH 3
TO 6 INCHES EXPECTED BY MID DAY TUESDAY. GIVEN FRESH SNOW COVER AND
850 MB TEMPERATURES DROPPING WELL BELOW -20...OVERNIGHT LOWS SHOULD
BE ABLE TO FALL BELOW ZERO. LOWERED TEMPS TUESDAY NIGHT THROUGH
THURSDAY NIGHT IN THIS REGARD. WIND CHILLS WILL DIP TO -20 AT TIMES
DURING THE MIDDLE OF THE WEEK...WITH ADVISORY CONDITIONS LIKELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 654 AM EST SAT JAN 3 2015
(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 134 AM EST SAT JAN 3 2015
LIFR CONDS TO PERSIST THROUGH THE PD AS WIDESPREAD PCPN CONTS
INADV OF POTENT SRN STREAM SW EJECTING OUT OF W TX THIS MORNING.
RAIN XPCD TO DIMINISH TO DZ LT THIS AFTERNOON AND MUCH OF TONIGHT
AS MID LVL DRY SLOT ENVELOPES THE TERMINALS. HWVR LAGGING MID LVL
DEFORMATION ZONE AND EWD WRAP OF INTENSE LL CAA WING ALG
W/ATTENDANT RAPID INFLUX OF LK MSTR FLUX WILL SPELL A PD OF
ACCUMLATING SNOWFALL SUNDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING
FOR INZ008-009-012>018.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR INZ006-
007.
WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ003>005.
MI...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MIZ079>081.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077-
078.
OH...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR OHZ004-
005-015-016.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR OHZ001-
002.
LM...GALE WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT FOR
LMZ043-046.
&&
$$
UPDATE...FISHER
SYNOPSIS...FISHER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
700 AM EST SAT JAN 3 2015
.SYNOPSIS...
ISSUED AT 400 PM EST FRI JAN 2 2015
LOW PRESSURE WILL MOVE OUT OF THE SOUTHWEST TOWARDS THE SOUTHERN
GREAT LAKES SATURDAY NIGHT. A LARGE AREA OF MIXED PRECIPITATION
WAS OVERSPREADING THE AREA THIS MORNING AND WILL TRANSITION TO
RAIN AS THE MORNING PROGRESSES. HIGHS TODAY WILL RANGE FROM THE
MIDDLE 30S NORTHWEST TO NEAR 50 IN THE SOUTHEAST.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST SAT JAN 3 2015
IMPRESSIVE SRN STREAM SW TROUGH NOTED IN VAPOR THIS MORNING AND
BEGINNING TO LIFT OUT OF NM. THIS SYS WILL PHASE QUICKLY TONIGHT
W/NRN STREAM SW AMPLIFYING SEWD OUT OF THE NRN ROCKIES RESULTING IN
A RAPID NEWD EJECTION INTO SE CANADA BU SUN MORNING.
BROAD LOW-MID LVL MSTR SURGE JUST NOW GETTING UP INTO THE AREA
W/MORE VIGOROUS PRECIP DVLPMNT NOTED IN COMPOSITE RADAR IMAGERY BACK
ACRS CNTRL IL INTO WRN IN AND POSES AN ICING PROB EARLY ON
W/CURRENT SFC TEMPS IN THE UPR 20S. HWVR LL WAA QUITE INTENSE AS
NOTED OVR SRN IL/IN AND XPCD TO PROGRESS NWD THROUGH THIS MORNING.
GIVEN GOOD 00Z CONSENSUS W/CORRESPONDING RUC NOD TO SFC TEMPS CUT
BACK TIMING OF ADVISORY ACRS FAR SRN TIER OF COUNTIES YET WILL HOLD
W/REMAINDER OF ADVISORY SEGMENTS PER LTL XPCD SFC BASED WARMING
WILL OCCUR UNTIL MID-LT MORNING TIED TO DEEPER ERLY FLW TRAJECTORIES
AND MUCH LWR THETA-E AIR ORIGINATING FM OLD POLAR RIDGE.
REGARDLESS LL WAA WILL OVERWHELM SHALLOW SFC BASED COLD LYR BY LT
MORNING/ERLY AFTN S-N W/A DECENT RAIN EVENT XPCD ESP SE HALF. MID
LVL DRY SLOT WILL OVERSPREAD AREA LT THIS AFTN WEST AND OVERNIGHT
EAST ALTHOUGH TEMPS WILL FAIRLY MILD. EXCEPTION WILL BE FAR WEST
WHERE INTENSE LL CAA WING WILL BEGIN TO WRAP SEWD BEHIND DEPARTING
SFC LOW. LEFT OVER DEFORMATION ZONE AND RAPID INFLUX OF COLD AIR
WILL LEAD TO A RAPID CHG OVR TO ACCUMULATING SNOW FAR NW AND
EXPANDING SEWD DURING THE DAY AS MSTR FLUX OFF LK MI TAKES OFF. SHLD
SEE A PD OF ROBUST LK ENHANCEMENT THROUGHOUT THE NW HALF SUN AFTN
W/AT LEAST AN INCH OR TWO OF SNOWFALL XPCD.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 403 AM EST SAT JAN 3 2015
BITTERLY COLD CONDITIONS CAN BE EXPECTED FOR MUCH OF THE LONG TERM
FORECAST DURING THE UPCOMING WEEK. STRONG COLD AIR ADVECTION WILL BE
OCCURRING AT THE START OF THIS PERIOD SUNDAY NIGHT. A STRONG UPPER
LEVEL DISTURBANCE WILL SUPPORT THE DEVELOPMENT OF A CLIPPER TYPE
SYSTEM THAT SHOULD RACE ACROSS THE AREA MONDAY NIGHT INTO EARLY
TUESDAY. FAVORED THE ECMWF RUN TO RUN CONSISTENCY AND HANDLING OF
THIS SYSTEM. TEMPERATURES WILL BE COLD ENOUGH FOR ALL SNOW...WITH 3
TO 6 INCHES EXPECTED BY MID DAY TUESDAY. GIVEN FRESH SNOW COVER AND
850 MB TEMPERATURES DROPPING WELL BELOW -20...OVERNIGHT LOWS SHOULD
BE ABLE TO FALL BELOW ZERO. LOWERED TEMPS TUESDAY NIGHT THROUGH
THURSDAY NIGHT IN THIS REGARD. WIND CHILLS WILL DIP TO -20 AT TIMES
DURING THE MIDDLE OF THE WEEK...WITH ADVISORY CONDITIONS LIKELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 654 AM EST SAT JAN 3 2015
(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 134 AM EST SAT JAN 3 2015
LIFR CONDS TO PERSIST THROUGH THE PD AS WIDESPREAD PCPN CONTS
INADV OF POTENT SRN STREAM SW EJECTING OUT OF W TX THIS MORNING.
RAIN XPCD TO DIMINISH TO DZ LT THIS AFTERNOON AND MUCH OF TONIGHT
AS MID LVL DRY SLOT ENVELOPES THE TERMINALS. HWVR LAGGING MID LVL
DEFORMATION ZONE AND EWD WRAP OF INTENSE LL CAA WING ALG
W/ATTENDANT RAPID INFLUX OF LK MSTR FLUX WILL SPELL A PD OF
ACCUMLATING SNOWFALL SUNDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 11 AM EST /10 AM CST/ THIS MORNING
FOR INZ008-009-012>018.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR INZ006-
007.
WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ003>005.
MI...WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MIZ079>081.
WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077-
078.
OH...WINTER WEATHER ADVISORY UNTIL 11 AM EST THIS MORNING FOR OHZ004-
005-015-016.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR OHZ001-
002.
LM...GALE WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT FOR
LMZ043-046.
&&
$$
SYNOPSIS...FISHER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1002 AM EST Sat Jan 3 2015
...Forecast Update...
Issued at 1000 AM EST Fri Jan 2 2015
The warm front is rapidly pushing northward at this hour and will be
through our northern CWA by early afternoon. Current obs show BWG at
56/54 with SDF at 46/44. Have seen a surge in showers and scattered
thunderstorms west of I-65 on the nose of the 50-60 knot low level
jet. These showers are basically signaling the warm frontal passage.
Did go ahead and increase thunder coverage to scattered as several
lightning strikes are showing up. Otherwise, current forecast is on
track and have only updated to reflect the latest temp, dewpoint,
wind and precipitation coverage trends.
.SHORT TERM (Now through Sunday)...
Issued at 300 AM EST Sat Jan 3 2015
Latest water vapor imagery with 500 mb RAP heights shows a deep
closed low across southern New Mexico while a ridge lies off the
Florida coast. In between, broad southwesterly flow has been
bringing a very moist and warm air mass into the Ohio Valley. At the
surface, high pressure is departing the region, allowing a warm
front to lift through TN and KY. Early morning temperatures range
from the upper 30s across southern IN to upper 40s across southern
KY.
As a surface low deepens to our west, plan on the warm front to lift
through Kentucky this morning and reach southern Indiana by early
afternoon. As the region becomes well within the warm sector,
temperatures will top out right around 60 degrees for much of the
area. Southern Kentucky locations are most likely to get into the
lower 60s. Southerly winds will increase throughout the day as well,
as soundings show a rather strong 850 mb jet of 55+ knots at about
2-3kft. An inversion in the lowest levels of the atmosphere should
keep these strong winds from mixing down, but it will still be gusty
at times today.
Precipitation this morning is expected to be on the lighter side,
mainly in the form of drizzle or light rain showers. Precipitation
chances/coverage will then steadily increase today as isentropic
upglide picks up and the region becomes more in the nose of the
850mb moisture transport axis. The greatest forcing/lift arrives by
mid/late afternoon through the evening hours as the cold front
swings through the state. Just ahead of this front, PWATs climb to
1.6 inches, which would be record values for this time of year for
BNA/ILN. Overall, a very moist air mass will be in place and though
the system is expected to be progressive, any training showers will
be capable of some moderate to locally heavy rainfall, especially
across the southern forecast area. Plan on rainfall amounts to range
from 1.5 to locally 2 inches across the area through Sunday morning.
Thunder chances are still included in the forecast as MUCAPE values
are progged to be around 500 J/kg this afternoon. Tonight`s low will
be quite mild, held up due to lingering precipitation and southerly
flow. Plan on readings to only into the mid 40s to lower 50s,
warmest east of I-65.
Cold air advection kicks in between midnight and sunrise Sunday,
resulting in a steady drop in temperatures during the day Sunday.
Morning readings in the mid 40s to near 50 are expected to fall into
the mid 30s to around 40 by mid/late afternoon. At the same time,
03.00z guidance continues to show lingering wrap around moisture
behind the departing low pressure system. As temperatures aloft
reach -8 to -10c, there may be enough saturation left to squeeze out
a few snowflakes across southern Indiana and northern Kentucky.
Otherwise, Sunday afternoon will be noticeably colder especially
given cloudy skies and a brisk west/northwest wind 15-20 mph, making
it feel more like the middle 20s at times.
.LONG TERM (Sunday night through Friday)...
Issued at 257 AM EST Sat Jan 3 2015
...Very Cold Temperatures and Wind Chills Mid-Week...
Canadian high pressure crossing the region Sunday night and Monday
will bring a quick shot of chilly air. Low clouds will likely hang
around for much of the night Sunday night, but should clear out just
in time to allow sunrise readings to drop into the 15-20 degree
range. We`ll have sunshine on Monday but the mercury will only
recover into the middle 20s in southern Indiana and around 30 in
Kentucky.
A quick moving clipper type system will zip by to our north Monday
night/Tuesday. The models have trended slightly faster and farther
south with this feature. Looking at atmospheric cross-sections,
even in the northernmost reaches of the LMK CWA around Madison,
there`s quite a bit of dry low level air Monday night, and then on
Tuesday when some low level moisture does move in it`s very
shallow. So, it still appears, at least for now, that measurable
precipitation is unlikely with this system. Will, however, include
a chance of flurries generally north of a Salem-Frankfort-Carlisle
line. Also, it should be noted that the GEM brings accumulating
snows to southern Indiana and northern Kentucky late Monday night.
This solution is an outlier, but these types of systems can do
surprising things sometimes, so it`s still something to keep an eye
on.
Strong Canadian high pressure will then invade Tuesday night through
Thursday. A tight surface pressure gradient on the nose of the
incoming high pressure Wednesday could give us some afternoon gusts
around 20 mph. With temperatures reaching only into the teens in
southern Indiana and the 20s in Kentucky, Wednesday will be a cold
day.
Then it will get worse. Lows Wednesday night, as the cold heart of
the Canadian high moves in, will be in the 0 to 5 degree range. Add
to that a northwest breeze around 10 mph and we could be looking at
advisory level wind chills of 10 to 15 degrees below zero as the
kids head out to the bus stops Thursday morning. Highs Thursday
afternoon will struggle to reach 20.
A cold front will sweep through the Ohio and Tennessee Valleys
Thursday night/Friday. However, the Gulf of Mexico will be
completely shut off by the departing mid-week high, so no
precipitation is expected.
&&
.AVIATION (12Z TAF Update)...
Issued at 618 AM EST Sat Jan 3 2015
IFR/LIFR ceilings to persist at all TAF sites today as a warm front
lifts from TN through KY into Indiana later this afternoon.
Widespread showers/drizzle will mainly impact SDF/LEX this morning
but large band of showers and embedded thunderstorms currently
across AR/MO will slide east over the area this afternoon and
evening. LLWS threat will continue past sunrise today through the
afternoon hours as there will be a very strong 2000 ft jet
/southwest at 55 kts/ with southeast surface winds at 10 kts. Toward
the end of the period, a cold front will pass through, shifting
winds to the west. Moisture trapped in the low levels will keep IFR
to low-end MVFR ceilings in place. Weakening but still strong 850 mb
jet may allow higher winds to mix down post front as well, with
gusts up to 30-35 mph possible.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....ZBT
Long Term......13
Aviation.......ZBT
AREA FORECAST DISCUSSION
NWS JACKSON KY
735 AM EST SAT JAN 3 2015
.UPDATE...
ISSUED AT 735 AM EST SAT JAN 3 2015
UPDATED THE GRIDS TO REFLECT THE LATEST RADAR TRENDS AND HRRR DATA.
ALSO REFINED THE T AND TD GRIDS FOR THE NEXT SEVERAL HOURS PER THE
LATEST OBS AND TRENDS. THESE HAVE BEEN SENT TO THE NDFD AND WEB
SERVERS.
&&
.SHORT TERM...(TODAY THROUGH SUNDAY)
ISSUED AT 335 AM EST SAT JAN 3 2015
08Z SFC ANALYSIS SHOWS A WARM FRONT LIFTING THROUGH EASTERN KENTUCKY
IN CONJUNCTION WITH AN AREA OF LOW PRESSURE DEVELOPING TO THE
SOUTHWEST. SOME LIGHT RAIN SHOWERS HAVE BEEN ASSOCIATED WITH THIS
BOUNDARY ALONG WITH PATCHES OF FOG AND LOW CIGS. TEMPERATURES ARE
RATHER MILD ACROSS THE AREA WITH MID 30S FOUND NORTH OF THE FRONT AND
LOW 40S TO THE SOUTH OF IT. DEWPOINTS THROUGH THE AREA ARE WITHIN A
DEGREE OR TWO OF THE AIR TEMPERATURE.
THE MODELS ARE IN GOOD AGREEMENT ALOFT THROUGH THE SHORT TERM PORTION
OF THE FORECAST. THEY ALL DEPICT A CLOSED LOW CURRENTLY OVER SOUTHERN
NEW MEXICO BEING PICKED UP BY THE NORTHERN STREAM FLOW TODAY AND
MOVING THROUGH THE OHIO VALLEY ON SUNDAY AS A FULL LATITUDE TROUGH.
THE LATEST ECMWF AND NAM ARE THE MOST SIMILAR WITH THIS TRANSITION
AND WERE LEANED ON MOST FOR THIS FORECAST. IN ADDITION...THE LATEST
HRRR WAS INCORPORATED INTO THE NEAR TERM PORTION OF THE FORECAST.
SENSIBLE WEATHER WILL FEATURE A RATHER WARM EARLY JANUARY DAY ACROSS
EASTERN KENTUCKY AS SCATTERED SHOWERS MOVE THROUGH DURING THE MORNING
HOURS. AN INVERSION WILL KEEP THE GUSTY WINDS JUST OFF THE SFC FROM
AFFECTING THOSE OF US AT GROUND LEVEL. HOWEVER...THIS COULD BREAK BY
AFTERNOON AND BRING SOME OF THOSE GUSTY WINDS TO THE SFC. IN
ADDITION...THE DEEPENING LOW TO THE WEST AND ITS WARM FRONT NORTH OF
THE AREA WILL SET THE STAGE FOR A POTENTIAL OF MAINLY ELEVATED
THUNDERSTORMS...THOUGH THEY COULD BECOME SFC BASED...ESPECIALLY IF
THE CLOUDS THIN OR BREAK OVER THIS PART OF THE STATE LATER TODAY. THE
HIGHEST POPS AND STEADIER RAINS SHOULD STAY WEST OF THE AREA FOR MUCH
OF THE DAY...THOUGH IF ANY BANDS DO SET UP AHEAD OF THE COLD FRONT
WE COULD SEE HEAVY TO EXCESSIVE RAINS GIVEN THE VERY HIGH PWATS FOR
THIS PART OF THE YEAR. MOST LIKELY...THOUGH...THE BEST RAINS WILL STAY
TO THE WEST OF THE AREA...CLOSER TO THE CORE OF THE SYSTEM...UNTIL
LATER IN THE EVENING AND OVERNIGHT WHEN THE COLD FRONT LUNGES THIS
WAY. WITH THIS PASSAGE...EXPECT A PERIOD OF HEAVY RAIN AND POSSIBLE
THUNDERSTORMS ALONG WITH GUSTY SOUTHWEST WINDS. AT THIS POINT WILL
HOLD OFF ON ANY FLOOD WATCHES GIVEN THE EXPECTATION OF DOWNSLOPING IN
THE EAST AND SOME DRY SLOTTING AHEAD OF THE COLD FRONT. THE POTENTIAL
FOR HEAVY RAINS TONIGHT WILL BE HIT HARD IN THE HWO ALONG WITH
THE CONCERN FOR GUSTY WINDS. THE FRONT GOES THROUGH SHORTLY AFTER 12Z
SUNDAY WITH FALLING TEMPERATURES EXPECTED THROUGH THE REST OF THE
DAY. WOULD ALSO EXPECT SOME WRAP AROUND AND UPSLOPE PCPN TO DEVELOP
IN THE FRONT/S WAKE LATER IN THE AFTERNOON. THIS...COMBINED WITH
FALLING TEMPERATURES...WILL LIKELY RESULT IN SOME LIGHT SNOW SHOWERS
AROUND THE AREA INTO SUNDAY EVENING. WHILE NO ACCUMULATIONS ARE
EXPECTED FROM THIS...THERE COULD BE BRIEF DUSTINGS WHERE ANY HEALTHY
SNOW SHOWER PASSES. WILL ADD THIS FLEETING SNOW POTENTIAL TO THE
HWO...AS WELL.
AGAIN USED THE BCCONSSHORT AS A STARTING POINT FOR TEMPS...TD...AND
WINDS THROUGH 21Z TODAY AND THEN THE SUPERBLEND THROUGH 00Z MONDAY.
ONLY SLIGHTLY TWEAKED POINT TEMPERATURE DATA FOR MAXES AND MINS. AS
FOR POPS...FAVORED A BLEND OF THE HRRR AND NAM12 EARLY THEN MAINLY
THE NAM12 TONIGHT INTO SUNDAY. GENERALLY UNDERCUT MOS TODAY...
ESPECIALLY EAST...WENT CATEGORICAL TONIGHT...AND THEN ENDED UP
HIGHER THAN MOS FOR SUNDAY AFTERNOON AND EVENING.
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 340 AM EST SAT JAN 3 2015
THE UPPER LEVEL PATTERN THROUGH THE EXTENDED FORECAST PERIOD WILL
FEATURE A BROAD TROUGH OVER THE GREAT LAKES AND NEW ENGLAND REGIONS
WITH A SERIES OF SHORTWAVES ROUNDING THE BASE OF THE TROUGH AND
MOVING THROUGH THE LOWER GREAT LAKES AND OH VALLEY REGION. TOWARDS
THE END OF THE EXTENDED PORTION OF THE FORECAST ON THURSDAY AND INTO
FRIDAY A STRONG JET STREAK DIVES SOUTHEAST OUT OF CENTRAL CANADA AND
INTO THE LOWER TN VALLEY AS THE LONGWAVE TROUGH OVER THE EASTERN
CONUS DEEPENS AND A POTENT SHORTWAVE MOVES THROUGH THE MID ATLANTIC
STATES AND OFF THE ATLANTIC COAST. FOR THE MOST PART...THE MODELS
AGREE WITH WITH THE OVERALL PROGRESSION OF THE LONGWAVE PATTERN.
CLOSER TO THE SURFACE...A COLD FRONT WILL EXIT EASTERN KENTUCKY ON
SUNDAY NIGHT WITH SOME WRAP AROUND MOISTURE...THOUGH
SHALLOW...MAKING IT THROUGH EASTERN KENTUCKY. WITH THE COLDER AIR
FILTERING INTO THE AREA IN EARNEST...THIS WILL RESULT INTO A CHANGE
OVER TO SOME SNOW SHOWERS AND IS EXPECTED TO BE SHORT IN DURATION AS
THE MOISTURE AND UPPER TROUGH WILL BE QUICK TO EXIT. DO NOT EXPECT
MORE THAN A DUSTING WITH THIS ACTIVITY. COLDER AIR WILL BE WELL
ENTRENCHED THROUGH THE AREA FOR MONDAY AND TUESDAY AND ESPECIALLY
THROUGH THE REST OF THE EXTENDED. THE NEXT COLD FRONT WILL PUSH
THROUGH THE OH VALLEY ON TUESDAY AND TUESDAY NIGHT. IN NORTHWEST
FLOW...THE BEST MOISTURE AND LIFT WITH THIS FEATURE APPEARS TO BE
NORTH OF THE OH RIVER AND THEREFORE LITTLE PRECIP POSSIBLE INTO
EASTERN KENTUCKY. THIS THINKING IS INLINE WITH THE RESULT OF THE ALL
MODEL BLEND AND AS SUCH HAVE STAYED WITH A DRY FORECAST. DID GO WITH
SOME FLURRIES IN THE VERY NORTH THOUGH WITH NO MEASURABLE PRECIP
EXPECTED.
THIS FRONT MOVES THROUGH TUESDAY NIGHT AND QUITE AN ARCTIC AIRMASS
FOLLOWS IN BEHIND THIS FEATURE. ARCTIC HIGH PRESSURE WILL MOVE
SOUTHEAST INTO THE LOWER MS RIVER VALLEY AND WITH IT...SOME VERY
COLD AND DRY AIR. THIS WILL KEEP EASTERN KENTUCKY DRY FOR THE REST
OF THE EXTENDED FORECAST PERIOD AND BRING SOME NEAR ZERO
TEMPERATURES FOR THURSDAY MORNING AND DRY AIR. DEW POINTS FOR
THURSDAY WILL DROP INTO THE NEGATIVE DIGITS AND ONLY RISE INTO THE
TEENS FOR FRIDAY. A COLD AND DRY TREND WILL BE IN STORE FOR THE END
OF NEXT WEEK.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 715 AM EST SAT JAN 3 2015
MVFR CIGS HAVE OVERTAKEN THE EASTERN KENTUCKY SITES THIS MORNING WITH
A FEW PATCHES OF LOWER VIS AND CIGS CLOSER TO THE WARM FRONT. EXPECT
CIGS TO BOUNCE BETWEEN LOW VFR AND MVFR THROUGH THE DAY WITH
SCATTERED SHOWERS AROUND. THINGS GET MORE INTERESTING IN THE
AFTERNOON WHEN THE INVERSION SHOULD BREAK FOR MOST PLACES ALLOWING
SCATTERED SHOWERS TO BECOME MORE ROBUST WITH A POTENTIAL FOR STRAY
THUNDERSTORMS. HOWEVER...THE MAIN CONCERN WILL BE WITH THE ACTUAL
COLD FRONT PASSING THROUGH LATER TONIGHT WITH A POTENTIAL FOR A
SQUALL LINE OF HEAVIER RAIN AND LOW CIGS/VIS ALONG WITH THUNDER.
ANOTHER CONCERN IS LLWS THROUGH MIDDAY AS WINDS INCREASE JUST OFF
THE SURFACE TO BETWEEN 40 AND 45 KNOTS THIS MORNING. DO EXPECT SOME
MIXING OF THE GUSTS TO THE SFC LATER THIS AFTERNOON...ESPECIALLY IF
SOME BREAKS IN THE SKY COVER OCCUR AS WE SIT IN THE DEVELOPING
SYSTEM/S WARM SECTOR. OTHERWISE...WINDS WILL PICK UP BY AFTERNOON
FROM THE SOUTH AT 10 TO 20 KTS WITH HIGHER GUSTS POSSIBLE THROUGH THE
AFTERNOON AND INTO THE EVENING. THE WINDS CONTINUE TO BE BREEZY
TONIGHT AS THEY TURN MORE TO THE SOUTHWEST.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
UPDATE...GREIF
SHORT TERM...GREIF
LONG TERM...SHALLENBERGER
AVIATION...GREIF
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
623 AM EST Sat Jan 3 2015
.SHORT TERM (Now through Sunday)...
Issued at 300 AM EST Sat Jan 3 2015
Latest water vapor imagery with 500 mb RAP heights shows a deep
closed low across southern New Mexico while a ridge lies off the
Florida coast. In between, broad southwesterly flow has been
bringing a very moist and warm air mass into the Ohio Valley. At the
surface, high pressure is departing the region, allowing a warm
front to lift through TN and KY. Early morning temperatures range
from the upper 30s across southern IN to upper 40s across southern
KY.
As a surface low deepens to our west, plan on the warm front to lift
through Kentucky this morning and reach southern Indiana by early
afternoon. As the region becomes well within the warm sector,
temperatures will top out right around 60 degrees for much of the
area. Southern Kentucky locations are most likely to get into the
lower 60s. Southerly winds will increase throughout the day as well,
as soundings show a rather strong 850 mb jet of 55+ knots at about
2-3kft. An inversion in the lowest levels of the atmosphere should
keep these strong winds from mixing down, but it will still be gusty
at times today.
Precipitation this morning is expected to be on the lighter side,
mainly in the form of drizzle or light rain showers. Precipitation
chances/coverage will then steadily increase today as isentropic
upglide picks up and the region becomes more in the nose of the
850mb moisture transport axis. The greatest forcing/lift arrives by
mid/late afternoon through the evening hours as the cold front
swings through the state. Just ahead of this front, PWATs climb to
1.6 inches, which would be record values for this time of year for
BNA/ILN. Overall, a very moist air mass will be in place and though
the system is expected to be progressive, any training showers will
be capable of some moderate to locally heavy rainfall, especially
across the southern forecast area. Plan on rainfall amounts to range
from 1.5 to locally 2 inches across the area through Sunday morning.
Thunder chances are still included in the forecast as MUCAPE values
are progged to be around 500 J/kg this afternoon. Tonight`s low will
be quite mild, held up due to lingering precipitation and southerly
flow. Plan on readings to only into the mid 40s to lower 50s,
warmest east of I-65.
Cold air advection kicks in between midnight and sunrise Sunday,
resulting in a steady drop in temperatures during the day Sunday.
Morning readings in the mid 40s to near 50 are expected to fall into
the mid 30s to around 40 by mid/late afternoon. At the same time,
03.00z guidance continues to show lingering wrap around moisture
behind the departing low pressure system. As temperatures aloft
reach -8 to -10c, there may be enough saturation left to squeeze out
a few snowflakes across southern Indiana and northern Kentucky.
Otherwise, Sunday afternoon will be noticeably colder especially
given cloudy skies and a brisk west/northwest wind 15-20 mph, making
it feel more like the middle 20s at times.
.LONG TERM (Sunday night through Friday)...
Issued at 257 AM EST Sat Jan 3 2015
...Very Cold Temperatures and Wind Chills Mid-Week...
Canadian high pressure crossing the region Sunday night and Monday
will bring a quick shot of chilly air. Low clouds will likely hang
around for much of the night Sunday night, but should clear out just
in time to allow sunrise readings to drop into the 15-20 degree
range. We`ll have sunshine on Monday but the mercury will only
recover into the middle 20s in southern Indiana and around 30 in
Kentucky.
A quick moving clipper type system will zip by to our north Monday
night/Tuesday. The models have trended slightly faster and farther
south with this feature. Looking at atmospheric cross-sections,
even in the northernmost reaches of the LMK CWA around Madison,
there`s quite a bit of dry low level air Monday night, and then on
Tuesday when some low level moisture does move in it`s very
shallow. So, it still appears, at least for now, that measurable
precipitation is unlikely with this system. Will, however, include
a chance of flurries generally north of a Salem-Frankfort-Carlisle
line. Also, it should be noted that the GEM brings accumulating
snows to southern Indiana and northern Kentucky late Monday night.
This solution is an outlier, but these types of systems can do
surprising things sometimes, so it`s still something to keep an eye
on.
Strong Canadian high pressure will then invade Tuesday night through
Thursday. A tight surface pressure gradient on the nose of the
incoming high pressure Wednesday could give us some afternoon gusts
around 20 mph. With temperatures reaching only into the teens in
southern Indiana and the 20s in Kentucky, Wednesday will be a cold
day.
Then it will get worse. Lows Wednesday night, as the cold heart of
the Canadian high moves in, will be in the 0 to 5 degree range. Add
to that a northwest breeze around 10 mph and we could be looking at
advisory level wind chills of 10 to 15 degrees below zero as the
kids head out to the bus stops Thursday morning. Highs Thursday
afternoon will struggle to reach 20.
A cold front will sweep through the Ohio and Tennessee Valleys
Thursday night/Friday. However, the Gulf of Mexico will be
completely shut off by the departing mid-week high, so no
precipitation is expected.
&&
.AVIATION (12Z TAF Update)...
Issued at 618 AM EST Sat Jan 3 2015
IFR/LIFR ceilings to persist at all TAF sites today as a warm
front lifts from TN through KY into Indiana later this afternoon.
Widespread showers/drizzle will mainly impact SDF/LEX this morning
but large band of showers and embedded thunderstorms currently
across AR/MO will slide east over the area this afternoon and
evening. LLWS threat will continue past sunrise today through the
afternoon hours as there will be a very strong 2000 ft jet
/southwest at 55 kts/ with southeast surface winds at 10 kts.
Toward the end of the period, a cold front will pass through,
shifting winds to the west. Moisture trapped in the low levels
will keep IFR to low-end MVFR ceilings in place. Weakening but
still strong 850 mb jet may allow higher winds to mix down post
front as well, with gusts up to 30-35 mph possible.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Short Term........ZBT
Long Term.........13
Aviation..........ZBT
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
624 AM CST SAT JAN 3 2015
.AVIATION...
FOR THE 12/03Z TAFS...WIDESPREAD SHWRS AND SOME EMBEDDED TSTMS
WILL PERSIST THROUGH THE FIRST HALF OF THE TAF PERIOD FOR MOST OF
OUR AREA TERMINALS...GRADUALLY ENDING FROM WEST TO EAST LATER
TODAY AS A COLD FRONT SWEEPS ACROSS THE REGION. LOW CLOUDS WILL
LAG BEHIND THE FRONT SO MVFR/IFR CIGS WILL LINGER THROUGH THE
AFTERNOON AND POSSIBLY THE EARLY EVENING HOURS AT OUR ERN TAF
SITES. VSBYS WILL ALSO REMAIN IN FLUX WITH THE RAINFALL AND
RESULTING BR...GENERALLY IN THE MVFR RANGE BUT CANNOT RULE OUT
SOME IFR PERIODS WITH HEAVIER RAINFALL. WINDS WILL BE MOSTLY
VARIABLE AVERAGING AROUND 10 KTS WITH HIGHER GUSTS IN CONVECTION
AND EXPECT VEERING TO A SW DIRECTION LATER THIS MORNING AHEAD OF
THE COLD FRONT...EVENTUALLY BECOMING W AND THEN NW TOWARD THE END
OF THE PERIOD AS THE FRONT ADVANCES EWRD WITH CONDITIONS IMPROVING
TO VFR AROUND 04/00Z AND SHORTLY THEREAFTER AT ELD/MLU. /19/
&&
.PREV DISCUSSION... /ISSUED 549 AM CST SAT JAN 3 2015/
DISCUSSION...
SORRY FOR THE LATE PRODUCTS...AS SOME OF THESE STORMS DECIDED TO
GO ROGUE ON US THIS MORNING AS THE STORMS ROLLED INTO SHV/DEEP E
TX/WCNTRL LA. BUT THE LEADING EDGE OF THE STORMS/GUSTY WINDS HAVE
ACCELERATED E QUICKLY ACROSS NCNTRL LA AS OF 11Z...MUCH FASTER
THAN THE 00Z NAM/GFS. THE HRRR HAS INITIALIZED ON THIS WELL...AS
HAVE HAD TO MAKE A COUPLE OF ADDITIONAL CHANGES TO THE TEMPS TODAY
AS THIS SHALLOW/COLDER AIR QUICKLY OVERTAKES THE WARM SECTOR
ACROSS NCNTRL LA. EARLIER THIS MORNING AS OF 06Z...THERE WAS A SFC
LOW IN VC OF LFK...BUT THIS HAS BECOME ILL-DEFINED AS THE
CONVECTION ACCELERATED E...WITH WHAT LIMITED OF A SVR THREAT
DIMINISHES FURTHER THIS MORNING AS THIS SFC TROUGH QUICKLY SPREADS
E TOWARDS THE MS RIVER. WILL STILL HAVE TO CONTEND WITH LOCALLY
HEAVY RAINFALL THIS MORNING/EARLY AFTERNOON ACROSS EXTREME ERN
TX/N LA/SCNTRL AR...WHERE WIDESPREAD 3-5+ INCHES OF RAIN HAS
FALLEN IN THE LAST WEEK...AND PW/S ARE FORECAST TO APPROACH NEAR
RECORD VALUES FOR JANUARY /PER CLIMATOLOGY/. BELIEVE THAT THE
HEAVY RAINFALL THREAT WILL DIMINISH AFTER 18Z AS THE STRONGER
STORMS EXIT THE AREA...BUT WILL ALLOW THE CURRENT FLASH FLOOD
WATCH TO EXPIRE AS SCHEDULED AT 22Z.
SHOULD SEE THE STRATOCU LINGER THROUGH THE AFTERNOON...ALTHOUGH
SOME BREAKS WILL BE POSSIBLE LATER IN THE DAY ACROSS E TX...WHICH
WOULD RESULT IN A LITTLE BETTER WARMING THAN AREAS FARTHER N AND
E. GIVEN THE FASTER MOVEMENT OF THE SFC TROUGH THIS MORNING...HAVE
ALSO TRIMMED BACK MAX TEMPS OVER EXTREME NW LA...WITH MAX TEMPS
FARTHER E ACROSS NCNTRL LA OCCURRING BY DAYBREAK WITH TEMPS
FALLING DURING THE DAY.
THE SHORT TERM PROGS ARE STILL IN AGREEMENT WITH OUR ARCTIC FRONT
MOVING INTO THE REGION AFTER 06Z...DEEPENING LATE THROUGH SUNDAY
AS A 1040MB SFC RIDGE BUILDS E ACROSS THE CNTRL/SRN PLAINS. SHOULD
SEE THE FIRST FREEZE OF THE NEW YEAR MONDAY MORNING...AS THE SKY
CLEARS AND WINDS DECOUPLE IN THE VERY COLD/DRY AIR MASS BUILDING
IN. A SECOND ARCTIC FRONT WILL QUICKLY BUILD SE INTO THE AREA
TUESDAY AHEAD OF THE NEXT LONGWAVE TO DIVE SE ACROSS THE CNTRL/ERN
CONUS...WITH WHAT SHOULD BE THE COLDEST TEMPS SO FAR THIS WINTER
SEASON...WITH SE OK/NRN SECTIONS OF SW AR POSSIBLY FALLING INTO
THE TEENS...WITH THE REMAINDER OF THE REGION WELL INTO THE 20S.
HAVE KEPT THE REMAINDER OF THE EXTENDED DRY GIVEN THE DRY NW FLOW
ALOFT...ALTHOUGH THE POTENTIAL FOR -SHRA APPEARS TO INCREASE NEXT
WEEKEND AS A SHORTWAVE BEGINS TO OPEN UP AND SHIFT E ACROSS THE
SRN PLAINS...RESULTING IN ENHANCED OVERRUNNING AS THE ARCTIC AIR
MASS BEGINS TO MODIFY.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 54 39 46 27 46 / 100 0 0 0 0
MLU 66 42 49 28 46 / 100 20 0 0 0
DEQ 51 32 40 21 41 / 70 10 0 0 0
TXK 53 37 41 23 42 / 90 10 0 0 0
ELD 57 39 46 24 43 / 100 10 0 0 0
TYR 53 34 44 25 45 / 50 0 0 0 0
GGG 53 37 44 25 45 / 90 0 0 0 0
LFK 57 37 50 27 48 / 100 0 0 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: ARZ072-073.
LA...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: LAZ001>006-010>014-017>022.
OK...NONE.
TX...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: TXZ151>153-165>167.
&&
$$
19
AREA FORECAST DISCUSSION
NWS SHREVEPORT LA
549 AM CST SAT JAN 3 2015
.DISCUSSION...
SORRY FOR THE LATE PRODUCTS...AS SOME OF THESE STORMS DECIDED TO
GO ROGUE ON US THIS MORNING AS THE STORMS ROLLED INTO SHV/DEEP E
TX/WCNTRL LA. BUT THE LEADING EDGE OF THE STORMS/GUSTY WINDS HAVE
ACCELERATED E QUICKLY ACROSS NCNTRL LA AS OF 11Z...MUCH FASTER
THAN THE 00Z NAM/GFS. THE HRRR HAS INITIALIZED ON THIS WELL...AS
HAVE HAD TO MAKE A COUPLE OF ADDITIONAL CHANGES TO THE TEMPS TODAY
AS THIS SHALLOW/COLDER AIR QUICKLY OVERTAKES THE WARM SECTOR
ACROSS NCNTRL LA. EARLIER THIS MORNING AS OF 06Z...THERE WAS A SFC
LOW IN VC OF LFK...BUT THIS HAS BECOME ILL-DEFINED AS THE
CONVECTION ACCELERATED E...WITH WHAT LIMITED OF A SVR THREAT
DIMINISHES FURTHER THIS MORNING AS THIS SFC TROUGH QUICKLY SPREADS
E TOWARDS THE MS RIVER. WILL STILL HAVE TO CONTEND WITH LOCALLY
HEAVY RAINFALL THIS MORNING/EARLY AFTERNOON ACROSS EXTREME ERN
TX/N LA/SCNTRL AR...WHERE WIDESPREAD 3-5+ INCHES OF RAIN HAS
FALLEN IN THE LAST WEEK...AND PW/S ARE FORECAST TO APPROACH NEAR
RECORD VALUES FOR JANUARY /PER CLIMATOLOGY/. BELIEVE THAT THE
HEAVY RAINFALL THREAT WILL DIMINISH AFTER 18Z AS THE STRONGER
STORMS EXIT THE AREA...BUT WILL ALLOW THE CURRENT FLASH FLOOD
WATCH TO EXPIRE AS SCHEDULED AT 22Z.
SHOULD SEE THE STRATOCU LINGER THROUGH THE AFTERNOON...ALTHOUGH
SOME BREAKS WILL BE POSSIBLE LATER IN THE DAY ACROSS E TX...WHICH
WOULD RESULT IN A LITTLE BETTER WARMING THAN AREAS FARTHER N AND
E. GIVEN THE FASTER MOVEMENT OF THE SFC TROUGH THIS MORNING...HAVE
ALSO TRIMMED BACK MAX TEMPS OVER EXTREME NW LA...WITH MAX TEMPS
FARTHER E ACROSS NCNTRL LA OCCURRING BY DAYBREAK WITH TEMPS
FALLING DURING THE DAY.
THE SHORT TERM PROGS ARE STILL IN AGREEMENT WITH OUR ARCTIC FRONT
MOVING INTO THE REGION AFTER 06Z...DEEPENING LATE THROUGH SUNDAY
AS A 1040MB SFC RIDGE BUILDS E ACROSS THE CNTRL/SRN PLAINS. SHOULD
SEE THE FIRST FREEZE OF THE NEW YEAR MONDAY MORNING...AS THE SKY
CLEARS AND WINDS DECOUPLE IN THE VERY COLD/DRY AIR MASS BUILDING
IN. A SECOND ARCTIC FRONT WILL QUICKLY BUILD SE INTO THE AREA
TUESDAY AHEAD OF THE NEXT LONGWAVE TO DIVE SE ACROSS THE CNTRL/ERN
CONUS...WITH WHAT SHOULD BE THE COLDEST TEMPS SO FAR THIS WINTER
SEASON...WITH SE OK/NRN SECTIONS OF SW AR POSSIBLY FALLING INTO
THE TEENS...WITH THE REMAINDER OF THE REGION WELL INTO THE 20S.
HAVE KEPT THE REMAINDER OF THE EXTENDED DRY GIVEN THE DRY NW FLOW
ALOFT...ALTHOUGH THE POTENTIAL FOR -SHRA APPEARS TO INCREASE NEXT
WEEKEND AS A SHORTWAVE BEGINS TO OPEN UP AND SHIFT E ACROSS THE
SRN PLAINS...RESULTING IN ENHANCED OVERRUNNING AS THE ARCTIC AIR
MASS BEGINS TO MODIFY.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 54 39 46 27 46 / 100 0 0 0 0
MLU 66 42 49 28 46 / 100 20 0 0 0
DEQ 51 32 40 21 41 / 70 5 0 0 0
TXK 53 37 41 23 42 / 90 5 0 0 0
ELD 57 39 46 24 43 / 100 10 0 0 0
TYR 53 34 44 25 45 / 50 0 0 0 0
GGG 53 37 44 25 45 / 90 0 0 0 0
LFK 57 37 50 27 48 / 100 0 0 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: ARZ072-073.
LA...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: LAZ001>006-010>014-017>022.
OK...NONE.
TX...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: TXZ151>153-165>167.
&&
$$
15
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1048 AM EST SAT JAN 3 2015
.SYNOPSIS...
A STORM SYSTEM IS EXPECTED TO BRING A MIX OF SNOW, SLEET AND
FREEZING RAIN ACROSS NORTHEAST PENNSYLVANIA AND CENTRAL NEW YORK
ON TODAY. THE WINTRY MIX WILL THEN CHANGE TO RAIN TONIGHT...FOLLOWED BY
WARMER TEMPERATURES AND SHOWERS ON SUNDAY. A SHARP COOL DOWN WILL
FOLLOW FOR SUNDAY NIGHT INTO EARLY NEXT WEEK ACCOMPANIED BY STRONG
WINDS AND LAKE EFFECT SNOW.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1050 AM UPDATE...
PCPN ON TRACK TO MV INTO CWA FM CNTRL PA AS WMFNT IS DVLPNG ACRS
THE MIDWEST INTO NWPA AT THIS TIME. STRONG ISENTROPIC UPGLIDE
ALLOWING PCPN TO BREAK OUT BACK TO THE SOUTHWEST. AS WARM
ADVECTION STRENGTHENS OVR THE NEXT SVRL HRS ON DVLPNG LOW-LVL JET
EXPECT PCPN TO ENCOMPASS ENTIRE CWA BY 20Z THIS AFTN. HV DELAYED
ONSET BY AN HR OR TWO AS RADAR IS PICKING UP ON MID-DECK WITH JUST
VRY LGT SNOW NOW FALLING OVR SRN LUZERNE CNTY.
RADAR POP-UP SKEW-T INDICATING ENTIRE COLUMN BLO FRZG CWA-WIDE
WITH 800MB TEMPS WARMING TWD 0C AS OF 1530Z. THIS SEEMS TO
CORRELATE WITH LATEST HIRES MODELS, INCLUDING HRRR AND RAP. STILL
EXPECTING SVRL HRS OF SNOW AT THE ONSET. AS TEMPS ALOFT WARM,
EXPECT A MIX OF SLEET AND FZRA TO WORK IN AS FAR EAST AS A
ONONDAGA-PIKE CNTY LINE BY 21Z. CLDR TEMPS WL BE ABLE TO HOLD IN
ACRS THE EAST THE LONGEST WITH SNOW POSSIBLE UNTIL CLOSE TO 00Z.
QUESTION CONTINUES TO CNTR ON HOW MUCH FZRA CAN BE EXPECTED AS CLD
LYR LKLY TO BE ALMOST 4KFT DEEP WITH MAX WARM LYR TEMPS ARND
800MB OF +3C TO +4C. AS COLD LYR DIMINISHES IN DEPTH AND TEMPS
WARM ALOFT TO +6C BTWN 21Z AND 00Z EXPECT THIS TO BE MOST LKLY
TIME FOR FZRA ACRS THE CWA. HWVR, THIS LEADS TO THE QUESTION OF
HOW MUCH ICE WL ACTUALLY BE ABLE TO ACCRETE AS WARM AIR IS DRAGGED
DOWN FM ALOFT. HV MASSAGED HRLY T/TD VALUES AND DELAYED ONSET OF
PCPN BY AN HR OR TWO TO GET A BETTER HANDLE ON CURRENT CONDITIONS
BUT NO MAJOR CHGS NEEDED AT THIS TIME.
PREV DISCUSSION BLO...
MAIN FOCUS FOR THE NEAR TERM CONTINUES TO BE WINTRY MIX DUE TO
ARRIVE BY LATER TODAY AS A STRENGTHENING LOW RIDES UP TO OUR WEST.
EXPECT SNOW TO BREAK OUT FROM SW TO NE BEGINNING NEAR MIDDAY WITH
MOST AREAS SEEING A FEW HOURS WORTH OF SNOWFALL BEFORE THE
TRANSITION IN P-TYPES BEGINS TOWARD THE MID TO LATE AFTERNOON.
GENERALLY LOOKING AT 1 TO 2 INCHES OF SLUSHY SNOW ACCUMULATION BEFORE
THIS OCCURS. AS THE WARMER AIR BEGINS TO MOVE IN ALOFT ASSOCIATED
WITH STRONG LLJ EXPECT TRANSIT ON TO SLEET/FREEZING RAIN TO OCCUR.
PROFILES CONTINUE TO INDICATE A RELATIVELY DEEP COLD LAYER IN THE
LOW LEVELS WHICH INDICATES MORE SLEET THAN FREEZING RAIN WILL OCCUR
DURING THE TRANSITION BEFORE THE CHANGE TO ALL RAIN OCCURS
TONIGHT. HOWEVER GIVEN THAT MOST OF THE AREA LOOKS TO SEE AT THE
LEAST A VERY BRIEF PERIOD OF FREEZING RAIN ALONG WITH THE SNOW AND
SLEET WE DO EXPECT SOME SLIPPERY CONDITIONS SO MAINTAIN THE WINTER
WEATHER ADVISORIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY NIGHT/...
THE TRANSITION FROM SNOW TO A WINTRY MIX TO RAIN WILL BE ONGOING EARLY
IN THE PERIOD. WESTERN PORTIONS OF THE CWA WILL HAVE CHANGED
MAINLY TO RAIN BY EARLY EVENING WITH THE TRANSITION ZONE AT THIS
TIME RIGHT NEAR THE I-81 CORRIDOR WHERE THE WINTRY MIX WILL BE
OCCURRING WITH TEMPS NEAR NEAR FREEZING. AS THE EVENING PROGRESSES
THIS TRANSITION ZONE WILL SHIFT EAST WITH THE EASTERN AREAS
LINGERING WITH SLEET AND FREEZING RAIN UNTIL ABOUT MIDNIGHT AS
COLD AIR STRUGGLES TO GET OUT OF THE MOUNTAINS AND MOHAWK VALLEY.
AS MENTIONED, MODELS CONTINUE BE IN PRETTY GOOD OVERALL AGREEMENT
BUT AS IS TYPICAL, THE NAM IS COLDEST IN THE LOW LEVELS AND WE
LEANED TONIGHT`S TEMPS IN THE EAST TOWARD NAM SOLUTION AS IT TENDS
TO DUE QUITE WELL WITH THESE TYPE OF COLD AIR DAMMING SCENARIOS.
FOLLOWING THE CHANGE OVER FROM WINTRY PRECIP, RAIN CONTINUES
OVERNIGHT INTO SUNDAY MORNING WITH TEMPS CONTINUING TO RISE. WHILE
THIS IS NOT EXPECTED TO BE ANY TYPE OF MAJOR HYDRO EVENT, IT IS
WORTH MENTIONING THAT TOTAL QPF AMOUNTS OF 1 TO 1.5 INCHES ARE
FORECAST BY THE TIME THE RAIN WINDS DOWN TO A FEW SHOWERS BY
AROUND MIDDAY SUNDAY. WE DON`T EXPECT FLOODING BUT THIS WILL BE
ENOUGH TO CAUSE RISES ON RIVERS.
CONDITIONS WILL BE VERY MILD WITH JUST A FEW SHOWERS BY SUNDAY
AFTERNOON. HIGHS WILL RANGE FROM THE MID 40S TO LOW 50S. THE
WARMTH WILL BE SHORT LIVED AS A STRONG COLD FRONT COMES THROUGH
SUNDAY EVENING WITH SHOWERS TRANSITIONING TO SNOW SHOWERS AND
POTENTIALLY SIGNIFICANT LAKE EFFECT SNOW BEGINNING TO SET UP SE OF
LAKE ONTARIO. THE COLD AIR AND SNOW SHOWERS / LAKE EFFECT WILL
ALSO BE ACCOMPANIED BY STRONG WINDS LIKELY GUSTING AT LEAST 30 TO
40 MPH.
&&
.LONG TERM /MONDAY THROUGH FRIDAY/...
430 AM UPDATE...
FORECAST UPDATED FOR LATEST MODEL TRENDS AND WPC GUIDANCE. WELL
ALIGNED FLOW MONDAY THROUGH MONDAY EVENING FOR POTENTIALLY
SIGNIFICANT LAKE EFFECT SNOW MAINLY NORTH OF THE THRUWAY...WITH
SIGNS OF GOOD UPSTREAM LAKE-TO-LAKE CONNECTIONS. WE MAY HAVE TO
SOON CONSIDER HOISTING A LAKE EFFECT WATCH FOR AT LEAST NORTHERN
ONEIDA COUNTY. ALSO...STRONG COLD AIR ADVECTION MONDAY WILL MEAN NON-
DIURNAL TEMPERATURES...THAT IS STEADY OR FALLING DURING THE DAY.
WINDS ALSO LOOK QUITE STOUT AS THE COLD AIR MOVES IN...WITH PEAK
GUSTS OF AT LEAST 30-40 MPH LOOKING PROBABLE. THE COMBINED EFFECTS
OF THOSE WINDS AND TEMPERATURES WILL LIKELY YIELD WIND CHILLS
FALLING INTO THE SINGLE DIGITS MONDAY AFTERNOON AND EVENING.
CONFIDENCE HAS INCREASED FOR AN AREAWIDE FEW FLUFFY INCHES OF SNOW
FROM CLIPPER SYSTEM TUESDAY. HAVE ACCORDINGLY ADJUSTED FORECAST TO
LIKELY FOR SNOW CHANCES.
AS ALREADY DISCUSSED BELOW...EVEN COLDER AIR EN ROUTE. LOOKS LIKE
REAL WINTER IS HERE.
PREVIOUS DISCUSSION...
LK EFFECT SNOW WL BE ONGOING ACRS NRN ZONES AT THE START OF THE
LONG TERM PD. SFC HIPRES WL BUILD INTO THE MID-ATLANTIC STATES
WITH RIDGE AXIS BRIEFLY LEADING TO QUIET WX TUE MRNG. WK CLIPPER
WL TRACK THRU THE CWA ON TUESDAY LEADING TO A FAIRLY GOOD SHOT OF
LIGHT SNOW QUICKLY FOLLOWED BY LAKE EFFECT ONCE AGAIN. NW FLOW WL
CONTINUE THRU THURSDAY FOLLOWED QUICKLY BY ANOTHER CLIPPER TWD THE
END OF NEXT WEEK.
COLD AIR FLOWING STRAIGHT OUT OF CANADA WL BRING THE COLDEST TEMPS
OF THIS WINTER TO THE AREA THUR MRNG. MED RANGE MODELS INDICATING
1000-500MB THICKNESSES DROPPING AOB 490DM. THIS WL LKLY TRANSLATE TO
LOWS DROPPING TO ARND OR JUST BLO 0F. HIGHS ON THURSDAY WL ONLY BE
ABLE TO RECOVER INTO THE TEENS SO IT APPEARS THAT A COLD AND ACTIVE
PATTERN IS ON TAP FOR THE NEXT WEEK.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
12Z UPDATE...
QUIET AND VFR INITIALLY THIS MORNING...THEN VERY COMPLICATED FOR THE
REMAINDER OF THE TAF PERIOD INCLUDING MULTIPLE PRECIPITATION TYPES
AND DEVELOPMENT OF LLWS AS MOIST STORM SYSTEM IMPACTS THE REGION.
PLEASE SEE TAFS FOR SPECIFICS ON EXPECTED TIMING...BUT GENERALLY
SPEAKING SNOW WILL OVERSPREAD THE AREA SOUTHWEST TO NORTHEAST
BETWEEN 17Z-20Z WITH RAPID DROP TO IFR VIS...LOWER THAN THAT NOT
OUT OF THE QUESTION. THE SNOW WILL THEN MIX WITH SLEET MID
AFTERNOON BEFORE CHANGING TO FREEZING RAIN OR RAIN LATE AFTERNOON-
EARLY EVENING /BEST CHANCE OF BRIEF PERIOD OF -FZRA WILL BE KBGM-
KRME/. AROUND THIS TIME...45-55 KT SSE JET WILL SETTLE LOW ENOUGH
OFF THE GROUND FOR LLWS CONDITIONS THROUGH EVENING. SURFACE WINDS
WILL BE VARIABLE OR LIGHT ESE PRE- DAWN...THEN INCREASE DURING THE
DAY TO STEADY SE ROUGHLY 10 KTS OR SO WITH GUSTS INTO UPPER TEENS
KTS LATE AFTERNOON ONWARD. KAVP-KBGM-KELM WINDS TO SLACKEN
SOMEWHAT LATER TONIGHT WHILE VEERING MORE SOUTHERLY...WITH LOSS
OF LLWS BUT CONTINUED -RA AND IFR CIG.
OUTLOOK...
SUN...MVFR TO IFR EARLY SUNDAY MORNING WITH RAIN...IMPROVING BY
SUNDAY AFTERNOON WITH ONLY SCT -SHRA.
MON/MON NGT...SCT SNOW SHOWERS AND BRIEF RESTRICTIONS WITH GUSTY
WINDS...BUT SIGNIFICANT RESTRICTIONS POSSIBLE KSYR-KRME FROM LAKE
EFFECT SNOW.
TUE/WED...RESTRICTIONS EXPECTED IN -SN AT ALL TERMINALS TUE AS
CLIPPER PASSES...THEN LAKE EFFECT -SHSN BRINGING RESTRICTIONS TO
NY TERMINALS ON WED.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR PAZ040.
WINTER WEATHER ADVISORY UNTIL 8 PM EST THIS EVENING FOR PAZ038-
039-043-044-047-048-072.
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ009-
036-037-045-046-057-062.
WINTER WEATHER ADVISORY UNTIL 8 PM EST THIS EVENING FOR
NYZ015>018-022>025-044-055-056.
&&
$$
SYNOPSIS...PCF
NEAR TERM...PCF/PVF
SHORT TERM...PCF
LONG TERM...MDP/PVF
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
529 AM CST SAT JAN 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CST SAT JAN 3 2015
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED STRONG SHORTWAVES OVER WEST CENTRAL ALBERTA...EASTERN
WASHINGTON STATE...NORTH CENTRAL MONTANA AND OVER THE FORECAST AREA.
ALSO AN UPPER LOW WAS PRESENT OVER NEW MEXICO. MOISTURE HAS BEEN
STREAMING NORTHWARD TOWARDS THE FORECAST AREA...DUE TO A SOUTHWARD
PULL AHEAD OF BOTH THE UPPER LOW AND THE STRONG SHORTWAVE OVER THE
AREA. PRECIPITABLE WATER PER GOES ANALYSIS HAS CLIMBED TO 0.5 INCH
OVER SOUTHERN WI...AND 1 INCH ALONG I-70 IN MO AND IL. THIS
MOISTURE...COMBINED WITH ISENTROPIC LIFT AND DPVA FORCING AHEAD OF
THE SHORTWAVE OVER THE FORECAST AREA...HAS RESULTED IN SNOW ACROSS
THE SOUTHEAST HALF OR SO OF THE FORECAST AREA. THE SNOW HAS NOW
PUSHED INTO MAINLY WI...WITH SUBSIDENCE AND DRYING WORKING IN FROM
THE WEST BEHIND THE SHORTWAVE. MEANWHILE...FARTHER WEST...A SURFACE
LOW HAS DEVELOPED NEAR BISMARCK ND DOWNSTREAM OF THE MONTANA
SHORTWAVE. 925MB TEMPS AHEAD OF THE LOW ARE GENERALLY 0 TO -6C
ACROSS MUCH OF THE DAKOTAS EASTWARD INTO WI. HOWEVER...-20C TO -30C
READINGS WERE LURKING TO THE NORTH ACROSS MUCH OF SOUTHERN CANADA.
NORTHERLY WINDS BEHIND THE LOW HAS BEGUN BRINGING THIS COLD AIR
SOUTH WITH READINGS OVER NORTHERN NORTH DAKOTA NOW IN THE SINGLE
DIGITS BELOW ZERO.
TODAY CONTINUES TO LOOK MUCH QUIETER ON THE PRECIPITATION SIDE OF
THINGS...RESULTING MOSTLY FROM DECENT SUBSIDENCE AND DRYING
OCCURRING IN THE WAKE OF THE SHORTWAVE CURRENTLY CROSSING THE
FORECAST AREA. ANY LINGERING SNOW OVER WI SHOULD PUSH OFF TO THE
EAST OF THE AREA BY 15Z. ALTHOUGH WE DO LOSE ICE IN THE CLOUDS WITH
THE PASSAGE OF THE SHORTWAVE...WE ALSO LOSE THE LIFT...SO THE
POTENTIAL FOR FREEZING DRIZZLE IS FURTHER REDUCED. MOST 03.00Z
GUIDANCE IS NOW MOSTLY DRY FOR THE FORECAST AREA TODAY AND HAVE
FOLLOWED SUIT. 925MB TEMPS STAY RELATIVELY MILD TODAY...-2 TO -4C.
IF WE WERE SUNNY TODAY...HIGHS COULD POP INTO THE 40S OVER SNOW FREE
AREAS. HOWEVER...A SOUTHERLY FLOW LOOKS TO ADVECT IN LOW CLOUDS FROM
MO AND IL THROUGH THE FORECAST AREA...WHICH GET TRAPPED UNDER THE
SUBSIDENCE INVERSION. IN FACT...CANNOT RULE OUT SOME FOG THIS
MORNING OVER THE HIGHER TERRAIN. THESE CLOUDS SHOULD KEEP HIGHS IN
THE UPPER 20S TO MID 30S...COLDEST OVER SNOW PACK LOCATIONS.
NOW FOR TONIGHT...A LOT MORE IS GOING ON.
1. SNOW LOOKS LIKELY. WE SHOULD BEGIN TO SEE A SNOW BAND SET UP THIS
AFTERNOON FROM CENTRAL NEBRASKA INTO NORTHEAST MN. THIS BAND...
ASSOCIATED WITH MID LEVEL FRONTOGENESIS AND DPVA DOWNSTREAM OF THE
CURRENT MONTANA SHORTWAVE TRACKING EAST...LOOKS TO MOVE INTO THE
NORTHWEST HALF OF THE FORECAST AREA DURING THE EVENING...THEN MARCH
EAST THROUGH THE REST OF THE FORECAST AREA OVERNIGHT. MODELS ARE IN
PRETTY GOOD AGREEMENT IN PRODUCING A TOTAL OF 0.10-0.15 INCHES OF
QPF WITH THE BAND...WHICH SEEMS REASONABLE WHEN LOOKING AT THE
FORCING AND 0.3-0.4 INCHES OF PRECIPITABLE WATER. WITH SNOW RATIOS
OF 15-18 TO 1 RANGE IN THE BAND...DUE TO COLDER AIR FLOWING IN
ALLOWING FOR UPWARDS OF 100MB OF EFFECTIVE DENDRITIC GROWTH...A
SOLID 1 TO 2 INCHES SEEMS REASONABLE WITH A 3 INCH AMOUNT POSSIBLE.
2. NORTHWEST WINDS ARE GOING TO INCREASE THROUGH THE NIGHT. THIS IN
RESPONSE TO THE UPPER LOW EJECTING OUT OF NEW MEXICO AND PHASING
WITH THE SHORTWAVE COMING THROUGH THE FORECAST AREA TONIGHT...
RESULTING IN A DEEPENING SURFACE LOW LIFTING INTO THE EASTERN GREAT
LAKES. 925MB WINDS INCREASE TO 35-40 KT BY 12Z SUNDAY...WHICH WITH
PRESSURES RISING RAPIDLY AS THOSE WINDS DRIVE IN COLDER AIR...A GOOD
AMOUNT OF THIS WIND SHOULD MIX DOWN. 20-25 KT WINDS FROM MAV
GUIDANCE OVER THE HIGHER TERRAIN OF SOUTHEAST MN/NORTHEAST IA SEEMS
REASONABLE...WITH GUSTS OF 30-35 KT. GIVEN THE FLUFFIER SNOW
TONIGHT...SOME BLOWING AND DRIFTING IS LIKELY WITH THESE WINDS
COMING THROUGH.
3. TEMPERATURES AND WIND CHILLS PLUMMETING OVERNIGHT. 925MB TEMPS
TANK FROM THE -2 TO -4C AT 00Z TO -10 TO -20C BY 12Z...COLDEST
NORTHWEST. THIS SHOULD DROP TEMPERATURES INTO THE SINGLE DIGITS AND
TEENS...AND EVEN BELOW ZERO IN SOME OF SOUTHEAST MN BY SUNRISE. WIND
CHILLS COULD BE APPROACHING ADVISORY CRITERIA BY 12Z SUNDAY IN
PORTIONS OF SOUTHEAST MN.
HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE WESTERN PORTIONS OF
SOUTHEAST MN AND NORTHEAST IA...FROM 06-12Z SUNDAY...TO HANDLE THE
NEAR ADVISORY WINDS...FALLING SNOW...WIND CHILLS APPROACHING
ADVISORY CRITERIA AND BLOWING/DRIFTING SNOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 311 AM CST SAT JAN 3 2015
MAIN LONG TERM FOCUSES ARE ON ARCTIC AIR AND A POSSIBLE ACCUMULATING
FLUFFY SNOW EVENT FOR MONDAY NIGHT.
THE POOL OF ARCTIC AIR SITUATED CURRENTLY ACROSS MUCH OF SOUTHERN
CANADA LOOKS TO INVADE THE REGION SUNDAY AND SUNDAY NIGHT...THANKS
TO THE SHORTWAVE OVER WEST CENTRAL ALBERTA DIGGING INTO THE REGION.
925MB TEMPS PLUMMET TO -20 TO -25C BY 00Z MONDAY ON A BRISK
NORTHWEST WIND...AND FURTHER LOWERING TO -24 TO -28C BY 12Z MONDAY.
TEMPERATURES THAT BEGAN FALLING TONIGHT WILL CONTINUE TO DO SO
THROUGH THE DAY SUNDAY AND INTO SUNDAY NIGHT. COMBINED WITH THE
BRISK NORTHWEST WIND...WIND CHILL ADVISORIES AND POSSIBLY A FEW
WARNINGS ARE GOING TO BE NECESSARY. THE ARCTIC AIR MODIFIES SOMEWHAT
ON MONDAY WITH 925MB TEMPS CLIMBING TO -18 TO -22C BY 00Z...ENOUGH
THAT WIND CHILL HAZARDS SHOULD BE ALLOWED TO END BY 20Z.
ON MONDAY NIGHT...A FAST MOVING BUT POTENT SHORTWAVE IS PROGGED TO
AFFECT THE REGION. GOOD MODEL CONSENSUS EXISTS FOR STRONG MID LEVEL
FRONTOGENESIS WITH DPVA ENHANCEMENT AND UPPER LEVEL DIVERGENCE TO
ACCOMPANY THE SHORTWAVE. QPF FORECASTS ARE IN THE 0.25-0.4 INCH
RANGE...WITH UPWARDS OF 200 MB OF EFFECTIVE DENDRITIC SNOW GROWTH.
THIS WOULD MEAN EASILY 20 TO 1 RATIOS...QUITE FLUFFY SNOW...AND
ACCUMULATIONS IN THE 4 TO 8 INCH RANGE. HOWEVER...PLACEMENT OF THE
BAND IS BECOMING A SERIOUS ISSUE AS THERE HAS BEEN A TREND FOR THE
SHORTWAVE TO TRACK FARTHER SOUTHWEST THROUGH IOWA IN THE 03.00Z
GFS/CANADIAN/ECMWF. THIS TAKES THE HEAVIER SNOW FARTHER SOUTH. SO
ITS HARD TO SAY RIGHT NOW EXACTLY HOW MUCH SNOW WE WILL SEE. AT THE
MOMENT HAVE 2 TO 5 INCHES...HIGHEST SOUTH OF I-90. EXPECT THESE
AMOUNTS TO CHANGE DUE TO BAND PLACEMENT AND INTENSITY. THE
FARTHER SOUTHWEST TREND HAS RESULTED IN LOWERED PRECIPITATION
CHANCES NORTH OF I-94.
PRECIPITATION SHOULD BE OUT OF THE AREA FOR TUESDAY...WITH MORE
ARCTIC AIR BEGINNING TO PLUNGE INTO THE REGION IN THE WAKE OF THE
SYSTEM...ESPECIALLY TUESDAY NIGHT. 925MB TEMPS TANK FROM -10 TO -16C
AT 12Z TO -16 TO -20C BY 00Z WEDNESDAY AND TO -25 TO -30C BY 12Z
WEDNESDAY. 925MB WINDS ALSO PROGGED IN THE 35-45 KT RANGE. LUCKILY
THE SOUNDING PROFILE MAY END UP BEING ISOTHERMAL TO HELP LIMIT
MIXING OF THESE STRONGER WINDS...BUT ITS GOING TO BE BRISK
NONETHELESS. MORE WIND CHILL ADVISORIES AND WARNINGS ARE LIKELY FOR
TUESDAY NIGHT INTO WEDNESDAY. ADDITIONALLY...THE WIND WILL HELP BLOW
THE RECENT FLUFFY SNOW AROUND SO ADDED SOME BLOWING SNOW.
BRIEF UPPER RIDGING DROPS DOWN OVER THE FORECAST AREA WEDNESDAY
NIGHT INTO THURSDAY...BRINGING SOMEWHAT WARMER AIR INTO THE FORECAST
AREA. HOWEVER...COMBINATION OF THE WINDS AND LINGERING ARCTIC AIR
LIKELY MEAN A CONTINUATION OF WIND CHILL HAZARDS INTO THURSDAY
MORNING. RIGHT NOW HAVE THURSDAY DRY...BUT THE WARM ADVECTION MAY BE
ENOUGH TO PRODUCE SOME LIGHT SNOW AND LATER FORECASTS COULD HAVE TO
INTRODUCE PRECIPITATION CHANCES. ANOTHER ARCTIC SURGE LOOKS POISED
TO FOLLOW FOR THURSDAY NIGHT THROUGH FRIDAY...NOT AS INTENSE AS
EARLIER ONES THIS WEEK BUT STRONG ENOUGH TO POSSIBLY NEED A FEW MORE
WIND CHILL ADVISORIES.
FINALLY...LOOKING AHEAD...THERE IS SIGNAL SHOWING UP TO BREAK OUT OF
THE ARCTIC REGIME FOR NEXT WEEKEND. IN FACT...THERE IS SIGNAL IN
BOTH THE CFS AND ECMWF TO EVEN GO BACK ABOVE NORMAL.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 529 AM CST SAT JAN 3 2015
MVFR CONDITIONS ARE EXPECTED AT THE TAF SITES THROUGH LATE THIS
AFTERNOON THEN CONDITIONS WILL DETERIORATE TO LIFR IN SNOW AND
BLOWING SNOW LATE THIS EVENING INTO THE OVERNIGHT HOURS. THE TAF
SITES WILL BE IN BETWEEN STORM SYSTEMS DURING THE DAYTIME HOURS
TODAY BUT THEN LOOK FOR SNOW TO OVERSPREAD THE REGION THIS EVENING
INTO THE OVERNIGHT. ALSO...NORTHWEST WINDS WILL INCREASE TO 18 TO
22 KTS WITH GUSTS TO AROUND 32 KTS AT TIMES. SNOW ACCUMULATIONS
OF 1 TO 2 INCHES ARE EXPECTED. THESE WINDS WILL CREATE BLOWING AND
DRIFTING SNOW...ESPECIALLY AT KRST. LOOK FOR VISIBILITIES TO LOWER
TO AROUND 1/2 MILE IN THE HEAVIER SNOW. ALSO...THE BLOWING SNOW
WILL REDUCE THE VISIBILITY TO AROUND 1/2 MILE OR LESS THROUGH MUCH
OF THE NIGHT INTO EARLY SUNDAY MORNING AT KRST.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR MNZ086-087-094-095.
IA...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR IAZ008>010-018-019-029.
&&
$$
SHORT TERM...AJ
LONG TERM...AJ
AVIATION...WETENKAMP
AREA FORECAST DISCUSSION
NWS PUEBLO CO
1223 PM MST SAT JAN 3 2015
.UPDATE...
ISSUED AT 1221 PM MST SAT JAN 3 2015
LATEST HRRR IS SHOWING SIGNIFICANT SNOW ACCUMS ALONG AND W OF I-25
THIS AFTERNOON AND EVE...UP TO 7 INCHES IN SPOTS. MAY BE A BIT
OVERDONE...BUT IS IN AGREEMENT WITH OVERALL MODEL CONSENSUS ON THE
BEST SNOW POTENTIAL...AND UPSTREAM OBS SUPPORT WIDESPREAD LIGHT TO
MDT SNOW. SO HAVE HOISTED A SNOW ADVISORY FOR THAT AREA THROUGH
THIS EVE. ROSE
UPDATE ISSUED AT 907 AM MST SAT JAN 3 2015
HAVE MADE SOME SIGNIFICANT REVISIONS TO THE FORECAST...MAINLY TO
DELAY TIMING OF PRECIP A BIT THIS AFTERNOON AS MOST OF THE
GUIDANCE SHOWS TIMING OF THE WIDESPREAD PRECIP TO BE CLOSE TO OR
AFTER 00Z. SATELLITE AND ALSO SHOW A FAIR AMOUNT OF SUN OVER
MUCH OF OUR CWA CURRENTLY. ONLY AREAS REALLY SEEING CLOUDS AND
PRECIP ATTM ARE BACA COUNTY AND THE UPPER ARKANSAS/LAKE COUNTY.
HAVE CUT BACK POPS FOR THE OTHER AREAS. MAIN DILEMMA TODAY WILL BE
THE SNOW AM`S OVER THE ERN PLAINS AND MTS. BULK OF THE 12-15Z
GUIDANCE IS CURRENTLY SHOWING THE BEST POTENTIAL FOR SNOW ACCUMS
TO BE OVER THE SRN MTS AND SRN I-25 CORRIDOR FROM KPUB TO KRTN.
SOME OF THE HIGH RES GUIDANCE...INCLUDING THE HRRR...SHOWS SOME
BANDS OF SNOW IN THIS AREA WITH POTENTIAL FOR SNOW AMTS GREATER
THAN FOUR INCHES...POSSIBLY REACHING ADVISORY CRITERIA.
HOWEVER...OTHER MODELS INCLUDING THE NAM SHOW LOWER QPF. WILL HAVE
TO TAKE A WAIT AND SEE APPROACH FOR THIS AREA. THE SNOW ADVISORY
FOR NRN EL PASO IS ALSO ON SHAKY GROUND...BUT WITH SOME GUIDANCE
SHOWING PERSISTENT ACCUMS IN THE 1-3 INCH RANGE AND THE POTENTIAL
FOR SOME BLOWING SNOW AND TRAVEL IMPACTS...WILL STAY THE COURSE
FOR NOW. ROSE
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 357 AM MST SAT JAN 3 2015
CURRENTLY...AN UPPER LEVEL LOW IS MOVING ACROSS SOUTHERN NEW MEXICO
AND SPREADING WIDESPREAD HIGH AND MID LEVEL CLOUDINESS ACROSS
EASTERN COLORADO. THIS HAS HELPED KEEP TEMPERATURES UP SO FAR THIS
MORNING WITH MOSTLY TEENS ACROSS THE REGION. RADAR INDICATES LIGHT
RETURNS FROM EASTERN LAS ANIMAS...INTO BACA AND PROWERS COUNTIES BUT
HAVE YET TO SEE ANY SNOW REPORTS FROM AREA OBSERVATIONS AT THIS
TIME. THAT BEING SAID...ITS LIKELY THAT AT LEAST A LITTLE BIT OF
LIGHT SNOW IS MAKING IT TO THE GROUND OVER THIS AREA AND WILL
CONTINUE TO BE POSSIBLE THROUGH SUNRISE.
TODAY...TWO UPPER LEVEL SYSTEMS TO DEAL WITH THROUGH THIS EVENING.
FIRST IS THE UPPER LEVEL LOW OVER SOUTHERN NEW MEXICO...WHICH IS
FORECAST TO EJECT NORTHEAST INTO CENTRAL OKLAHOMA BY THIS AFTERNOON.
MODELS AND THE LATEST RADAR IMAGERY KEEP THE POTENTIAL FOR LIGHT
SNOW GOING SOUTH OF A LAMAR TO TRINIDAD LINE THROUGH AROUND NOON.
ANY ACCUMULATIONS APPEAR TO BE MINOR WITH UP TO AN INCH OR SO
POSSIBLE OVER EXTREME SOUTHEASTERN BACA COUNTY.
THE SECOND SYSTEM IS A SHORTWAVE TROUGH DROPPING SOUTH OUT OF THE
NORTHERN ROCKIES. MODELS IN GOOD AGREEMENT WITH IT MOVING INTO
EASTERN COLORADO BY THIS AFTERNOON. FOLLOWED A BLEND OF THE VARIOUS
HIGH-RES MODELS AND THE NAM IN REGARDS TO FRONTAL AND PRECIPITATION
TIMING. MODELS HAVE THE THE COLD FRONT DROPPING SOUTH OVER THE
PALMER DIVIDE BY LATE MORNING...AND QUICKLY CLEARING THE EASTERN
PLAINS BY MID AFTERNOON. AHEAD OF THE FRONT...TEMPERATURES WILL
LIKELY WARM QUICKLY...WITH MID TO UPPER 30S AROUND THE PUEBLO
REGION. AREAS UNDER CLOUD COVER TO THE EAST WILL LIKELY ONLY REACH
THE 20S. COLD AIR WILL ADVECT QUICKLY BEHIND THE FRONT WITH 20S
ACROSS THE REGION BY LATE AFTERNOON. AS FAR AS
PRECIPITATION...EXPECT SNOW TO DEVELOP OVER THE CENTRAL MOUNTAINS
THIS MORNING AS THE UPPER SYSTEM APPROACHES. SNOW IS FORECAST TO
DEVELOP OVER THE PALMER DIVIDE ALONG THE FRONT...AND SPREAD SOUTH
ACROSS THE PLAINS THROUGH THE AFTERNOON AND EARLY EVENING HOURS.
THE PRIMARY FOCUS WILL BE THE PALMER DIVIDE...EASTERN MOUNTAINS AND
SOUTHERN I-25 CORRIDOR. A WINTER WEATHER ADVISORY HAS BEEN ISSUED
FOR NORTHERN EL PASO COUNTY...WITH STRONG WINDS BEHIND THE FRONT AND
SNOW CAUSING HAZARDOUS TRAVEL CONDITIONS OVER MONUMENT HILL. AS FAR
AS SNOW TOTALS...NORTHERN EL PASO COUNTY WILL SEE AROUND 1 TO 3
INCHES WHILE REST OF THE EASTERN PLAINS SEES LESS THAN 2 INCHES.
THE CENTRAL AND EASTERN MOUNTAINS WILL LIKELY SEE 2 TO 4 INCHES WITH
LOCALLY HIGHER AMOUNTS.
TONIGHT...THE SHORTWAVE TROUGH IS FORECAST TO QUICKLY MOVE INTO THE
CENTRAL PLAINS BY MIDNIGHT. MODELS IN GOOD AGREEMENT WITH SNOW
WINDING DOWN FROM NORTH TO SOUTH BY MIDNIGHT...WITH A FEW LINGERING
SNOW SHOWERS OVER THE CENTRAL AND EASTERN MOUNTAINS PERSISTING UNTIL
SUNDAY MORNING. COLD AIR WILL CONTINUE TO ADVECT SOUTHWARD WITH
OVERNIGHT LOWS BOTTOMING OUT IN THE SINGLE DIGITS...WITH A FEW
LOCATIONS DROPPING BELOW ZERO BY SUNDAY MORNING. THE OTHER MAIN
ISSUE FOR TONIGHT MAY BE WIND CHILL READINGS. WINDS WILL BE FAST TO
SUBSIDE ALONG THE I-25 CORRIDOR...SO NOT ANTICIPATING WIND CHILL
ISSUES THERE. BUT...OUT NEAR THE KANSAS BORDER...BREEZY CONDITIONS
WILL LIKELY PREVAIL THROUGH THE OVERNIGHT HOURS. WIND CHILL
READINGS WILL BE HOVERING AROUND ADVISORY THRESHOLDS...ESPECIALLY
OVER KIOWA AND PROWERS COUNTIES. IF YOU HAVE TO BE OUTSIDE FOR ANY
PROLONGED PERIODS LATE TONIGHT INTO SUNDAY MORNING...PREPARE FOR THE
VERY COLD CONDITIONS. MOZLEY
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 357 AM MST SAT JAN 3 2015
...MAIN FORECAST CHALLENGE NEXT WEEK WILL BE TEMPERATURES...
IN GENERAL...SOUTHERN COLORADO WILL BE UNDER A DRY NORTHWEST FLOW
PATTERN NEXT WEEK. THIS COULD YIELD SOME SNOW SHOWERS OVER THE
CENTRAL MOUNTAINS AT TIMES...BUT...FOR THE MOST PART...SHOULD BE
A DRY PATTERN.
HOWEVER...BEING IN NORTHWEST FLOW...WITH ARCTIC AIR NOT TOO FAR
AWAY ACROSS THE CENTRAL PLAINS...TEMPERATURE FORECASTS WILL BE A
CHALLENGE. THERE WILL BE A FEW OPPORTUNITIES FOR ARCTIC AIR TO
MAKE A QUICK RUN EAST INTO THE AREA THROUGH THE WEEK.
SUNDAY WILL BE A TEMPERATURE RECOVERY DAY...WITH TEMPERATURES
GENERALLY RUNNING BELOW BELOW AVERAGE...IN THE WAKE OF THE
SYSTEM THAT MOVES THROUGH TODAY.
MONDAY PRESENTS A TEMPERATURE CHALLENGE. CURRENT FORECAST IS FOR
NEAR AVERAGE TEMPERATURES...BUT THIS MAY BE TOO CONSERVATIVE. FOR
INSTANCE...AT PUEBLO...SOME GUIDANCE IS SUGGESTING 54 FOR A HIGH
OR POSSIBLY EVEN 61...WHILE THE CURRENT FORECAST IS CALLING FOR
JUST 46 DEGREES. CURRENT FORECAST IS THE END RESULT OF MODEL AND
FORECASTER CONSENSUS. THIS TIME OF YEAR...WITH STRONG OVERNIGHT
SURFACE INVERSIONS THAT LAST WELL INTO THE MORNING...COUPLED WITH
LONG NIGHTS AND SHORT DAYS TO BEGIN WITH...IT WOULD BE TOUGH TO
GET UP TO 60 DEGREES. SO FORECAST IS CONSERVATIVE. DOESN`T MEAN IT
WON`T HAPPEN. CONCEPTUALLY...THE MODELS SHOW A MODERATE STRENGTH
LEE TROUGH ON THE PLAINS WHICH COULD DRAW SOME CHINOOK WINDS OFF
OF THE MOUNTAINS. IF THIS HAPPENS...WE COULD SEE A QUICK AND
AGGRESSIVE WARMUP. SO...TEMPERATURE FORECASTS FOR MONDAY MAY HAVE
TO GO WAY UP JUST DEPENDING ON HOW THINGS UNFOLD.
TUESDAY...A SMALL AMOUNT OF COOL AIR FROM THE CENTRAL US PLAINS
LOOKS TO MOVE INTO THE EASTERN HALF OF THE FORECAST AREA. THE
SURGE DOESN`T LOOK EXCESSIVELY COOL AT THIS POINT...SO A FORECAST
OF NEAR AVERAGE TEMPERATURES LOOKS REASONABLE AND THIS IS WHAT IS
IN THE FORECAST AT THIS TIME.
FOR THE SECOND OR THIRD DAY IN A ROW...MOST MODELS HAVE A MUCH
STRONGER SURGE OF COLD AIR MOVING INTO THE EAST TUESDAY NIGHT AND
WEDNESDAY. CURRENT FORECASTS ARE STARTING TO REFLECT INCREASING
CONFIDENCE IN THE COOLING...AS REFLECTED BY HIGH TEMPERATURE
FORECASTS ONLY IN THE MID 20S TO MID 30S OVER MOST OF THE PLAINS
WEDNESDAY AFTERNOON. HOWEVER...HIGHS OVER THE EAST MAY HAVE TO BE
PUSHED DOWN EVEN FURTHER. ALSO...THIS SURGE COULD BE STRONG
ENOUGH TO PRODUCE SOME SCATTERED LIGHT PRECIPITATION OVER THE
EASTERN PLAINS TUESDAY NIGHT INTO WEDNESDAY MORNING.
THURSDAY COULD BE ANOTHER DAY WITH A QUICK WARMUP. MODELS ARE ONCE
AGAIN SHOWING POSSIBLE LEE TROUGHING ON THE PLAINS WHICH WOULD
DRAW WARMING CHINOOK WINDS OFF OF THE MOUNTAINS. CURRENT FORECAST
HIGH TEMPERATURES IN THE MID 40S TO MID 50S ACROSS THE PLAINS MAY
HAVE TO BE PUSHED UP 10 DEGREES IF SOME OF THE GUIDANCE IS RIGHT.
THURSDAY NIGHT AND FRIDAY...MODELS ARE HINTING AT YET ANOTHER PUSH
OF COOL AIR INTO THE EASTERN PLAINS. MUCH LIKE THE TUESDAY
NIGHT/WEDNESDAY SYSTEM...THIS COULD RESULT IN HIGH TEMPERATURES
COOLER THAN CURRENTLY FORECAST AND SOME SCATTERED LIGHT
PRECIPITATION. AS ALWAYS...PLEASE STAY TUNED.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1003 AM MST SAT JAN 3 2015
MAIN AVN CONCERN WILL BE THE COLD FRONT AND ASSOCIATED PRECIP
MOVING THROUGH THE ERN CO PLAINS THIS AFTERNOON AND EVENING.
LATEST FORECAST HAS SNOW BEGINNING OVER THE PALMER DVD IN ANOTHER
HOUR OR SO...THEN ADVANCING SWD TO VC KCOS BY 20-21Z. A PERIOD OF
-SN IS LIKELY AT KCOS...BUT SIGNIFICANT ACCUMS ARE NOT
EXPECTED...POSSIBLY AN INCH OR LESS. SNOW POTENTIAL AT KPUB IS A
LITTLE BETTER BY 22Z...AS SNOW BANDS DEVELOP SOUTH OF THE
ARKANSAS. KPUB WILL BE ON THE NRN FRINGES OF THE ACCUMULATING SNOW
AND COULD POTENTIALLY BE AFFECTED. MVFR CONDITIONS AT KPUB AND
KCOS ARE EXPECTED...WITH OCCASIONAL IFR POSSIBLE. SNOW SHOULD WIND
DOWN FROM N TO S BY 02-04Z...AND CONDITIONS SHOULD IMPROVE
THEREAFTER AT KCOS AND KPUB. AT KALS...SNOW IS LESS LIKELY...BUT
FG IS AGAIN EXPECTED TO DEVELOP AFTER 03Z TONIGHT...AND COULD
PERSIST INTO THE MORNING TO 15-16Z ON MON. ROSE
&&
.PUB WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 10 PM MST THIS EVENING FOR COZ074-
075-079-080-084-087-088.
&&
$$
UPDATE...ROSE
SHORT TERM...MOZLEY
LONG TERM...LW
AVIATION...ROSE
AREA FORECAST DISCUSSION
NWS DENVER/BOULDER CO
1028 AM MST SAT JAN 3 2015
.UPDATE...
ISSUED AT 1028 AM MST SAT JAN 3 2015
CURRENT FORECAST LOOKS ON TRACK. COLD FRONT HAS MOVED THROUGH
CHEYENNE IN THE PAST HOUR OR SO WITH NORTHERLY WINDS NOW GUSTING
UP CLOSE TO 30 MPH. COLD FRONT SHOULD MOVE THROUGH THE DENVER
AREA BY ABOUT NOON. SNOW WILL DEVELOP SHORTLY AFTER FRONTAL
PASSAGE AND QUITE A BIT OF BLOWING SNOW IS EXPECTED ACROSS THE
NORTHEAST PLAINS THROUGH THE AFTERNOON. THE UPPER DISTURBANCE
SHOULD BE MOVING OUT OF THE STATE BY MID-EVENING WITH IMPROVING
CONDITIONS ACROSS THE FORECAST AREA BY 10 PM...OR SOONER. WILL
LET THE ADVISORY FOR SNOW AND BLOWING SNOW STAND AS IT IS.
&&
.SHORT TERM...(TODAY THROUGH TONIGHT )
ISSUED AT 300 AM MST SAT JAN 3 2015
UPPER LEVEL DISTURBANCE AND ASSOCIATED COLD FRONT WILL MOVE
SOUTH AND SOUTHEAST THROUGH COLORADO THIS AFTERNOON AND EVENING
WITH A RETURN TO WINTER CONDITIONS. MAIN CONCERNS WILL BE SNOWFALL
POTENTIAL...BLOWING SNOW AND HAZARDOUS WINTER DRIVING CONDITIONS
ON THE PLAINS.
THE COLD FRONT HAS MOVED THROUGH PORTIONS OF NORTHEAST
WYOMING AS OF 3 AM...AND IS EXPECTED TO BE OVER THE COLORADO
BORDER AROUND 14-15Z AND THEN INTO THE DENVER AREA BETWEEN 11 AM
AND NOON. EXPECT INCREASING AND GUSTY N-NE WINDS OF 20-35KT WHICH
WILL CREATE SOME BLOWING SNOW. MOISTURE DEPTH INCREASES BEHIND
FRONT WITH UPSLOPE FLOW. THERE IS WEAK TO MODERATE LARGE SCALE
ASCENT WITH THIS SYSTEM...STRONGEST OVER THE NORTHEAST PLAINS.
LATEST MODEL RUNS ARE A BIT LESS WITH SNOWFALL BUT STILL IN THE
1-3 INCH RANGE...HIGHEST OVER THE NE PLAINS EAST OF DENVER.
DESPITE THE LOWER AMOUNTS...TRAVEL WILL BE TRICKY WITH
CONSIDERABLE BLOWING AND DRIFTING SNOW. WILL LEAVE CURRENT
ADVISORIES AS IS. THE LATEST RAP IS GENERATING HIGHER SNOWFALL
AMOUNTS NEAR THE FOOTHILLS WITH ENHANCED UPSLOPE. THIS MAY BE A
BIT OF A STRETCH BUT CERTAINLY BEARS WATCHING IN CASE ADVISORIES
ARE NEEDED FURTHER WEST.
THE STORM IS QUICK MOVING AS SNOW WILL RAPIDLY DIMINISH THIS
EVENING WITH SNOW ENDING IN SOUTHERN SECTIONS AROUND MIDNIGHT.
EXPECT CLEARING SKIES AS TEMPERATURES DROP BELOW ZERO AGAIN ON THE
PLAINS. WITH BRISK WINDS CONTINUING TONIGHT ON THE PLAINS MAY
NEED A WIND CHILL ADVISORY ON THE PLAINS.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 217 AM MST SAT JAN 3 2015
STG NWLY FLOW ALOFT WILL BE OVER NRN CO FROM SUN INTO MON. CROSS-
SECTIONS SHOW SOME MOISTURE EMBEDDED IN THE FLOW HOWEVER DESPITE
FAVORABLE OROGRAPHICS INSTABILITY WILL BE POOR AS LAPSE RATES ONLY
AVERAGE AROUND 3 C/KM THRU THE PERIOD. THUS EXPECT SOME PERIODS OF
LIGHT SNOW. MEANWHILE WITH STG FLOW ALOFT THERE WILL BE SOME
POTENTIAL FOR HIGH WINDS. OVERALL LOOKS LIKE THE HIGHEST WINDS
WILL STAY MAINLY ABOVE TIMBERLINE ON SUNDAY DUE TO LACK OF MTN
WAVE. LATE SUN NIGHT INTO MON THE MTN WAVE BECOMES MORE DEFINED
WHICH MAY ALLOW FOR STG WINDS TO AFFECT AREAS IN AND NR THE
FOOTHILLS.
OVER NERN CO IT LOOKS DRY BOTH DAYS WITH MAIN PROBLEM BEING HIGH
TEMPERATURES DUE TO LINGERING SNOWPACK. ON SUN WILL KEEP HIGHS IN
THE UPPER TEENS TO LOWER 20S OVER THE FAR NERN CORNER WITH LOWER 30S
POSSIBLE AROUND DENVER. IF INVERSIONS HOLD ALONG THE SOUTH PLATTE
RIVER VALLEY THEN HIGHS MAY STRUGGLE TO GET OUT OF THE TEENS. ON
MON SUBSTANTIAL WARMING IS FCST IN THE 850-700 MB LYR AS
DOWNSLOPE FLOW OCCURS ALONG THE FRONT RANGE. AS A RESULT GUIDANCE
TEMPS SHOOT UP INTO THE LOWER TO MID 50S AROUND DENVER WITH 40S
ACROSS THE PLAINS. AT THIS POINT BELIEVE LINGERING SNOWPACK WILL
STILL ALTER HIGHS SOMEWHAT SO WILL KEEP READINGS IN THE LOWER TO
MID 40S AROUND DENVER WITH 30S ACROSS THE PLAINS.
ON TUE THE FLOW ALOFT WILL BE WNW WITH NOT MUCH MOISTURE SHOWN IN
THE CROSS-SECTIONS SO WILL ONLY MENTION A SLIGHT CHC OF SNOW IN THE
MTNS WITH DRY CONDITIONS OVER NERN CO. AS FOR HIGHS BOTH THE GFS
AND ECMWF SHOW A SURGE OF COOLER AIR AFFECTING NERN CO MON NIGHT
INTO TUE MORNING. BY TUE AFTN THE GFS SHOWS THE SHALLOW LYR OF
COOLER MIXING OUT ALONG THE FRONT RANGE WHILE THE ECMWF DOES NOT.
AS A RESULT THERE IS A 10 DEGREE DIFFERENCE IN HIGH TEMPS OVER NERN
CO. FOR NOW WILL KEEP READINGS IN THE LOWER TO MID 40S NEAR DENVER
WITH LOWER TO MID 30S OVER THE FAR NERN PLAINS.
FOR TUE NIGHT INTO WED APPEARS ANOTHER SHOT OF COLDER AIR WILL
AFFECT NERN CO AS ARCTIC HIGH PRES BUILDS INTO THE NRN AND CNTRL
PLAINS. ALTHOUGH NERN CO WILL NOT TAKE A DIRECT HIT COULD EASILY
SEE HIGHS DROP BACK INTO THE TEENS OVER THE PLAINS WITH 20S ALONG
THE FRONT RANGE. MEANWHILE CROSS-SECTIONS ARE SHOWING SOME
POTENTIAL FOR FREEZING DRIZZLE OR VERY LIGHT SNOW LATE TUE NIGHT
INTO WED MORNING OVER NERN CO. IN THE MTNS IT LOOKS DRY ON WED.
ON THU DRY WNW FLOW ALOFT WILL BE OVER THE AREA AS A SFC LEE TROUGH
DEVELOPS ALONG THE FRONT RANGE. THIS SHOULD ALLOW FOR WARMER TEMPS
WITH READINGS RISING BACK INTO THE 40S ALONG THE FRONT RANGE. OVER
THE NERN PLAINS HIGHS MAY STAY IN THE 35 TO 40 DEGREE RANGE. BY FRI
THE GFS SHOWS A WEAK UPPER LEVEL RIDGE OVER THE AREA WHILE THE ECMWF
HAS NWLY FLOW ALOFT. DESPITE THE DIFFERING UPPER LVL PATTERNS BOTH
MODELS SHOW ANOTHER SHOT OF COOLER AIR MOVING INTO NERN CO THU NIGHT
INTO EARLY FRI. THE ECMWF HAS NO PCPN OVER THE AREA WHILE THE GFS
HAS SOME LIGHT PCPN OVER NERN CO. FOR NOW WILL KEEP FCST DRY AND
HAVE HIGHS RANGING FM THE UPPER 20S OVER THE FAR NERN CORNER WITH 35
TO 40 AROUND DENVER.
&&
.AVIATION...(FOR THE TAFS THROUGH 18Z SUNDAY MORNING)
ISSUED AT 1028 AM MST SAT JAN 3 2015
NORTHERLY WINDS ARE SHOWING UP IN NORTHERN WELD COUNTY AND SHOULD
SPREAD INTO DENVER AREA BETWEEN 18Z AND 19Z. CEILINGS HAVE ALREADY
LOWERED TO 6000 FEET AGL AS THE AIRMASS ALOFT MOISTENS. AFTER
FRONTAL PASSAGE...GUSTY NORTH-NORTHEAST WINDS WILL CONTINUE WITH
IFR CONDITIONS DEVELOPING. HEAVIEST SNOW ACCUMULATIONS WILL
PROBABLY BE BETWEEN 20Z AND 00Z. ACCUMULATIONS BETWEEN 2 AND 4
INCHES CAN BE EXPECTED.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...
WINTER WEATHER ADVISORY UNTIL 9 PM MST THIS EVENING FOR
COZ041>051.
&&
$$
UPDATE...DANKERS
SHORT TERM...ENTREKIN
LONG TERM...RPK
AVIATION...DANKERS
AREA FORECAST DISCUSSION
NWS JACKSONVILLE FL
233 PM EST SAT JAN 3 2015
.NEAR TERM...TONIGHT... PARTIAL SUNSHINE HELPING TO PUSH AFTERNOON
TEMPERATURES UP CLOSE TO RECORD VALUES IN SOME AREAS...NEW RECORD
HIGH SET AT JAX. MODEL GUIDANCE SUGGESTS LOW CLOUDS WILL DEVELOP
OVER THE AREA AGAIN LATE TONIGHT. THIS...ALONG WITH S TO SE FLOW
WILL KEEP LOW TEMPS UP TONIGHT IN LOW/MID 60S. MOS GUIDANCE
HITTING FOG HARD TONIGHT...HOWEVER...THINK THIS WILL BE LIMITED BY
20KT WINDS FORECAST ABOVE THE GROUND...WITH 4-6KT SFC WINDS...SO
FOCUSING MORE ON A LOW CLOUD DECK LATE TONIGHT THAN WIDESPREAD
FOG... THOUGH SOME PATCHY FOG COULD OCCUR IN SHELTERED AREAS.
RADAR CURRENTLY SHOWING A FEW SHOWERS NW FL ALONG W COAST SEABREEZE...
WHICH WILL WORK NORTHEASTWARD. NAM/HRRR SUGGEST POTENTIAL FOR SOME
SHOWERS TO DEVELOP LATE THIS AFTERNOON INTO EARLY EVENING OVER
EAST-CENTRAL PENINSULA WHERE THEY HAVE EAST AND WEST COAST SEA
BREEZES CONVERGE. GFS DOES NOT SHOW ANY PRECIP. SOME QUESTION OF
COVERAGE GIVEN DRY AIR/WARMER TEMPS ALOFT. GIVEN CURRENT SATLT/RADAR
TRENDS... WILL AT LEAST HAVE 20 POPS WITH SEA BREEZES THRU MID
EVENING.
SHORT TERM...SUNDAY...COLD FRONT WILL BE APPROACHING FROM THE WEST
EARLY SUNDAY AFTERNOON WITH A BAND OF SHOWERS AND WIDELY SCATTERED
THUNDERSTORMS PUSHING INTO SE GA AND THE SUWANNEE VALLY. MODELS IN
BETTER AGREEMENT WITH THE TIMING SHOWING FRONT BISECTING THE AREA
BY 00Z AND EXITING NE FL AROUND 06Z MONDAY. MODEL SOUNDINGS SHOW A
UNIDIRECTIONAL SW WIND PROFILE WITH DEEP LAYER SPEED SHEAR. THIS
ALONG WITH DRY MID LEVELS WOULD SUPPORT STRONG GUSTY WINDS IN ANY
STRONG THUNDERSTORMS THAT FORM. FORECAST CAPES IN 500-1000 J/KG
COULD BE ENOUGH WITH STRONG SHEAR TO PRODUCE ISOLATED STRONG TO
MARGINALLY SEVERE STORMS OVER MAINLY SE GA AS SHORT WAVE GOES BY
TO THE NORTH. TIMING OF STORMS SHOULD BE DURING THE AFTERNOON AND
EARLY EVENING HOURS.
MONDAY AND TUESDAY...RAIN WILL BE ENDING OVER NE FL EARLY MONDAY
MORNING AS DRIER AIR MOVES IN BEHIND COLD FRONT. WINDS WILL BECOME
ONSHORE MONDAY NIGHT AND TUESDAY AS MODELS SHOW WEAK INVERTED
TROUGH FORMING OVER THE ATLANTIC WATERS. THIS MAY PRODUCE ISOLATED
COASTAL SHOWERS NEAR THE COAST WITH DRY CONDITIONS INLAND. TEMPERATURES
WILL BE SEASONABLE.
.LONG TERM...WEDNESDAY THROUGH SATURDAY...MODELS CONTINUE TO SHOW
A STRONG ARCTIC OUTBREAK NEXT WEEK AS UPPER AIR PATTERN AMPLIFIES.
ECMWF MODEL SHOWS A 1060 MB SURFACE HIGH CENTERED OVER THE
NORTHERN PLAINS ON WEDNESDAY BUILDING SE. THIS HIGH CENTER WILL
MOVE INTO THE SOUTHERN PLAINS THURSDAY AND THE SOUTHEAST U.S.
THURSDAY NIGHT AND FRIDAY. MAX TEMPERATURES WILL FALL FROM NEAR
AVERAGE LEVELS ON WEDNESDAY TO WELL BELOW NORMAL THURSDAY(40S) AND
FRIDAY(50S) BEFORE REBOUNDING BACK TO NEAR NORMAL SATURDAY. MOS
GUIDANCE SHOWS HARD FREEZES OVER INLAND SE GA AND THE SUWANNEE
VALLEY OF NE FL WEDNESDAY NIGHT AND THURSDAY NIGHT. PRESSURE
GRADIENT WILL REMAIN TIGHT THROUGH THURSDAY WITH STRONG HIGH
BUILDING INTO THE AREA. THIS WILL KEEP WINDS ELEVATED WITH LOW
WIND CHILLS IN THE TEENS AND 20S WEDNESDAY NIGHT. THURSDAY NIGHT
WILL LIKELY BE THE COLDEST NIGHT AS WINDS DECREASE. AN ONSHORE
FLOW WILL INCREASE TEMPERATURES AND MOISTURE NEXT WEEKEND.
&&
.AVIATION...CIGS HAVE BEEN SLOW TO GET UP INTO VFR RANGE TODAY...BUT
MOST CIGS HAVE REACHED AT OR ABOVE BKN030 WITH LATEST OBSERVATIONS.
MODEL GUIDANCE SUGGESTS VFR CONDITIONS THRU SUNSET...THEN CIGS
LOWERING TO IFR LATER TONIGHT AND CONTINUING THROUGH SUN MORNING.
FOLLOWED THIS EVOLUTION IN LATEST TAFS.
&&
.MARINE...MODEL GUIDANCE SUGGESTS AN INCREASE IN SOUTHERLY FLOW LATER
TONIGHT... WITH 15-20 KTS LIKELY IN OFFSHORE COMPONENT...WILL HAVE
SCEC THERE. UNCERTAIN ABOUT THREAT OF SEA FOG...WHICH HRRR IS AGAIN
FORECASTING. WE DO HAVE MID/UPR 60S DEW POINTS OVER LAND...BUT
EXPECTED EAST COAST SEA BREEZE LIKELY TO KEEP IT OVER LAND THRU
SUNSET. LAND BREEZE THIS EVENING MAY ADVECT THE HIGHER DEW POINT
AIR OVER THE COASTAL WATERS...SUPPORTING SEA FOG FORMATION OVER
COOLER SHELF WATERS. UNCERTAINTY AS TO HOW WIDESPREAD OR DENSE
GIVEN 10-15KT SURFACE WINDS...BUT WILL INCLUDE AREAS OF FOG TONIGHT
FOR NEARSHORE COMPONENT...MAINLY EAST OF DUVAL COUNTY FL NORTHWARD.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 62 76 46 57 / 20 80 70 0
SSI 62 72 49 57 / 20 60 60 0
JAX 64 79 53 60 / 20 50 60 0
SGJ 65 77 56 59 / 20 30 50 20
GNV 63 77 56 62 / 10 50 60 10
OCF 65 79 58 64 / 10 30 50 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&
$$
WOLF/ZIBURA/
AREA FORECAST DISCUSSION
NWS PEACHTREE CITY GA
308 PM EST SAT JAN 3 2015
...SEVERE STORMS POSSIBLE NW GEORGIA AFTER MIDNIGHT...
...HEAVY RAIN LIKELY MUCH OF NORTH GEORGIA TONIGHT AND SUNDAY
MORNING...
.SHORT TERM /TONIGHT THROUGH SUNDAY NIGHT/...
ONLY MINOR REFINEMENTS MADE TO GRIDS SINCE LAST DISCUSSION /SEE
BELOW/ BASED ON OBSERVED TRENDS AND LATEST HRRR GUIDANCE. APPEARS
LINE OF CONVECTION STILL ON TARGET TO MOVE INTO NW GEORGIA AFTER
06Z THEN PUSH INTO ATL METRO AROUND 11-12Z WHILE ON A WEAKENING
TREND. WIDESPREAD DRIZZLE AND FOG WITH SCT -SHRA TO CONTINUE
UNTIL THEN.
PRECIP SHOULD END QUICKLY BEHIND MAIN PREFROTNAL SQUALL LINE. HAVE
MANUALLY DRAWN POPS AS LACK OF GOOD HOURLY MODEL GUIDANCE EXISTS
TODAY. COULD SEE VERY ISOLD CONVECTION BEHIND THIS LINE SUN
AFTERNOON BUT SUBJECTIVE EXPERIENCE IN THIS PATTERN IS COVERAGE
AND INTENSITY WILL BE MUCH LESS THAN INDICATED BY MODEL GUIDANCE.
WINDS SHOULD BE STRONG BUT REMAIN BELOW ADVISORY CRITERIA SUN AND
SUN EVENING.
SNELSON
.LONG TERM /MONDAY THROUGH SATURDAY/...
VERY FEW CHANGES NEEDED FOR THE LONG TERM PORTION OF THE FORECAST.
HIGH PRESSURE WILL MOVE OFFSHORE THE MID ATLANTIC COAST ON MONDAY IN
ADVANCE OF A COLD FRONT ON TUESDAY. TUESDAYS FRONT IS EXPECTED TO BE
DRY.
A STRONG AREA OF HIGH PRESSURE WILL BUILD BEHIND THE FRONT WEDNESDAY
INTO THURSDAY...BRINGING A MUCH COLDER AND DRIER AIRMASS TO THE
SOUTHEAST STATES. THERE WERE SOME EARLIER DIFFERENCES BETWEEN THE
LONGER TERM MODELS WITH FORECAST MINS AND MAX TEMPS WEDNESDAY INTO
THURSDAY...THE GFS HAS TRENDED A LITTLE COLDER AND CLOSER TO THE
ECMWF VALUES.
IN ADDITION TO THE COLDER TEMPERATURES...BREEZY OR EVEN WINDY
CONDITIONS ARE EXPECTED WEDNESDAY INTO EARLY THURSDAY. VALUES COULD
APPROACH WIND ADVISORY CRITERIA...AND BRING LOW WIND CHILLS.
TEMPERATURES ARE EXPECTED TO MODERATE FAIRLY QUICKLY FRIDAY INTO
THE WEEKEND.
NLISTEMAA
&&
.HYDROLOGY...
STILL ON TRACK TO SEE 1 TO 2 INCHES WITH AMOUNTS OVER 1.5 INCHES
CONFINED TO NE GA. BASED ON THIS EXPECTATION AND FFG HAVE DECIDED
NOT TO ISSUE ANY KIND OF FLOOD WATCH. WILL CONTINUE TO MONITOR
THIS EVENING.
SNELSON
&&
.PREV DISCUSSION... /ISSUED 149 PM EST SAT JAN 3 2015/
UPDATE... NEAR TERM FCST APPEARS ON TRACK. MAIN CONCERN IS
POTENTIAL FOR SVR STORMS AND HVY RAIN. 12Z SYNOPTIC MODELS AND
HIRES GUIDANCE INDICATING LINE OF CONVECTION SHOULD MOVE INTO NW
CORNER AROUND OR AFTER 06Z. NAM AND GFS 0-1KM BULK SHEAR
/35-45KTS/ AND MLCAPE /100-250 J/KG/ FAVORABLE FOR QLCS STORMS
WITH ISOLD WIND DMG AND EVEN BRIEF TORNADO POSSIBLE IN THE NW
1/3RD OF GA BETWEEN 06Z AND 12Z...MAINLY NORTH OF I-85.
LATEST QPF GUIDANCE INDICATING 1 TO 2 INCHES THRU 00Z MON WITH
ONLY NE GA AREA EXPECTING AMOUNTS OF 1.5 INCHES. 3HR FFG IS QUITE
LOW /2-2.5 INCHES/ IN NORTH GA DUE TO ANTECEDENT RAINFALL THE LAST
36 HRS. WILL BE COLLABORATING AND LOOKING AT A LITTLE MORE DATA
BEFORE DECIDING BUT FOR NOW HOLDING OFF ON WATCH.
SNELSON
&&
.AVIATION... 18Z UPDATE... LIFR/IFR CONDITIONS WILL PERSIST THRU
ABOUT 14Z SUN AFTER LINE OF HVY SHRA MOVES THRU. VFR CONDITIONS
LIKELY AFTER 17Z. EAST COMPONENT SFC WINDS WILL ALSO VEER TO SW
AFTER LINE OF SHRA MOVES THRU. COULD SEE ISOLD TSRA BUT WITH LOW
INSTABILITY...LIKELIHOOD TOO SMALL TO MENTION IN FCST.
//ATL CONFIDENCE...18Z UPDATE...
HIGH CONFIDENCE ON ALL ELEMENTS.
SNELSON
&&
.PRELIMINARY POINT TEMPS/POPS...
ATHENS 53 65 35 54 / 40 100 10 0
ATLANTA 57 62 34 50 / 60 100 10 0
BLAIRSVILLE 52 58 29 46 / 80 100 10 5
CARTERSVILLE 55 61 31 46 / 90 100 10 0
COLUMBUS 63 67 36 53 / 40 100 10 0
GAINESVILLE 49 61 33 50 / 50 100 10 0
MACON 63 69 37 55 / 30 100 10 5
ROME 55 60 30 45 / 100 100 5 5
PEACHTREE CITY 59 63 34 51 / 60 100 10 0
VIDALIA 63 75 42 58 / 30 80 70 5
&&
.FFC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
SHORT TERM...SNELSON
LONG TERM....NLISTEMAA
AVIATION...SNELSON
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
118 PM EST SAT JAN 3 2015
.SYNOPSIS...
ISSUED AT 104 PM EST SAT JAN 3 2015
LOW PRESSURE WILL MOVE OUT OF THE SOUTHWEST TOWARDS THE SOUTHERN
GREAT LAKES TONIGHT. RAIN WILL PERSIST ACROSS THE AREA THROUGH THE
AFTERNOON. HIGHS TODAY WILL RANGE FROM THE MIDDLE 30S NORTHWEST
TO NEAR 50 IN THE SOUTHEAST.
&&
.UPDATE...
ISSUED AT 102 PM EST SAT JAN 3 2015
HAVE ALLOWED MOST OF THE ADVISORY TO EXPIRE WITH TEMPERATURES AND
ROAD CONDITIONS SUFFICIENTLY IMPROVED TO ALLOW FOR BETTER TRAVEL
ACROSS THE AREA. SECONDARY ROADS WILL STILL REMAIN SLICK IN SOME
AREAS THROUGH THE AFTERNOON. ACROSS FAR NE INDIANA...FAR NW OHIO
AND INTO HILLSDALE COUNTY TEMPS WERE LINGERING AROUND 32 DEGREES
YET WITH CALL AROUND TO DISPATCHES STILL SHOWING ISSUES. RATHER
THAN HAVE TO ADDRESS AGAIN AT 2 PM HAVE OPTED TO EXTEND TO 4 PM
AND WILL ADDRESS WITH AFTERNOON PACKAGE WHEN IT SHOULD BE ABLE TO
EXPIRE.
NO OTHER MAJOR CHANGES TO GRIDS AT THIS TIME.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST SAT JAN 3 2015
IMPRESSIVE SRN STREAM SW TROUGH NOTED IN VAPOR THIS MORNING AND
BEGINNING TO LIFT OUT OF NM. THIS SYS WILL PHASE QUICKLY TONIGHT
W/NRN STREAM SW AMPLIFYING SEWD OUT OF THE NRN ROCKIES RESULTING IN
A RAPID NEWD EJECTION INTO SE CANADA BU SUN MORNING.
BROAD LOW-MID LVL MSTR SURGE JUST NOW GETTING UP INTO THE AREA
W/MORE VIGOROUS PRECIP DVLPMNT NOTED IN COMPOSITE RADAR IMAGERY BACK
ACRS CNTRL IL INTO WRN IN AND POSES AN ICING PROB EARLY ON
W/CURRENT SFC TEMPS IN THE UPR 20S. HWVR LL WAA QUITE INTENSE AS
NOTED OVR SRN IL/IN AND XPCD TO PROGRESS NWD THROUGH THIS MORNING.
GIVEN GOOD 00Z CONSENSUS W/CORRESPONDING RUC NOD TO SFC TEMPS CUT
BACK TIMING OF ADVISORY ACRS FAR SRN TIER OF COUNTIES YET WILL HOLD
W/REMAINDER OF ADVISORY SEGMENTS PER LTL XPCD SFC BASED WARMING
WILL OCCUR UNTIL MID-LT MORNING TIED TO DEEPER ERLY FLW TRAJECTORIES
AND MUCH LWR THETA-E AIR ORIGINATING FM OLD POLAR RIDGE.
REGARDLESS LL WAA WILL OVERWHELM SHALLOW SFC BASED COLD LYR BY LT
MORNING/ERLY AFTN S-N W/A DECENT RAIN EVENT XPCD ESP SE HALF. MID
LVL DRY SLOT WILL OVERSPREAD AREA LT THIS AFTN WEST AND OVERNIGHT
EAST ALTHOUGH TEMPS WILL FAIRLY MILD. EXCEPTION WILL BE FAR WEST
WHERE INTENSE LL CAA WING WILL BEGIN TO WRAP SEWD BEHIND DEPARTING
SFC LOW. LEFT OVER DEFORMATION ZONE AND RAPID INFLUX OF COLD AIR
WILL LEAD TO A RAPID CHG OVR TO ACCUMULATING SNOW FAR NW AND
EXPANDING SEWD DURING THE DAY AS MSTR FLUX OFF LK MI TAKES OFF. SHLD
SEE A PD OF ROBUST LK ENHANCEMENT THROUGHOUT THE NW HALF SUN AFTN
W/AT LEAST AN INCH OR TWO OF SNOWFALL XPCD.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 403 AM EST SAT JAN 3 2015
BITTERLY COLD CONDITIONS CAN BE EXPECTED FOR MUCH OF THE LONG TERM
FORECAST DURING THE UPCOMING WEEK. STRONG COLD AIR ADVECTION WILL BE
OCCURRING AT THE START OF THIS PERIOD SUNDAY NIGHT. A STRONG UPPER
LEVEL DISTURBANCE WILL SUPPORT THE DEVELOPMENT OF A CLIPPER TYPE
SYSTEM THAT SHOULD RACE ACROSS THE AREA MONDAY NIGHT INTO EARLY
TUESDAY. FAVORED THE ECMWF RUN TO RUN CONSISTENCY AND HANDLING OF
THIS SYSTEM. TEMPERATURES WILL BE COLD ENOUGH FOR ALL SNOW...WITH 3
TO 6 INCHES EXPECTED BY MID DAY TUESDAY. GIVEN FRESH SNOW COVER AND
850 MB TEMPERATURES DROPPING WELL BELOW -20...OVERNIGHT LOWS SHOULD
BE ABLE TO FALL BELOW ZERO. LOWERED TEMPS TUESDAY NIGHT THROUGH
THURSDAY NIGHT IN THIS REGARD. WIND CHILLS WILL DIP TO -20 AT TIMES
DURING THE MIDDLE OF THE WEEK...WITH ADVISORY CONDITIONS LIKELY.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 102 PM EST SAT JAN 3 2015
FREEZING PRECIP HAS ENDED AT BOTH SITES WITH PERIODS OF RAIN
EXPECTED THROUGH THE AFTERNOON. RAIN MAY END AT KSBN BUT SOME
DRIZZLE WILL REMAIN POSSIBLE. BIGGEST CHANGES TO TAFS WERE WITH
KFWA WHERE A LLWS GROUP WAS INTRODUCED AS KIWX 88D VAD WINDS AND
HI RES MODELS INDICATE A QUICK INCREASE IN LOW LEVEL WINDS IN
RESPONSE TO DEEPENING LOW PRESSURE. ONCE THE LOW PASSES
OVERHEAD...THE THREAT SHOULD DIMINISH. LATER THIS EVENING AS THE
STEADIER RAIN ENDS...THE WARM AIR ALOFT OVER THE COLD GROUND
SHOULD ALLOW FOR A FAVORABLE SETUP FOR SOME FOG DEVELOPMENT FOR A
PERIOD. HAVE ADDED THIS TO TAFS FOR OVERNIGHT.
FOCUS WILL THEN SHIFT TO COLD FRONT SET TO MOVE THROUGH AROUND 9Z
AT KSBN AND 11Z AT KFWA. LAKE ENHANCED SNOW SHOWERS WILL QUICKLY
TAKE SHAPE ACROSS KSBN GIVEN THEM A CONTINUATION OF IFR/LIFR
CONDITIONS. LITTLE IMPROVEMENT WILL OCCUR THROUGH 18Z WITH VSBYS
BECOMING A GREATER CONCERNS POTENTIALLY AFTER 18Z AS A SECONDARY
WAVE MOVES IN AND BRINGS A BURST OF ADDITIONAL SNOWFALL TO THE
AREA (WHICH WILL ALSO IMPACT KFWA). FURTHER CHANGES WILL LIKELY
OCCUR TO THE TAFS IN LATER FORECASTS.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR INZ006-
007.
MI...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR
MIZ079>081.
OH...WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR OHZ001-
002.
LM...GALE WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT FOR
LMZ043-046.
&&
$$
UPDATE...FISHER
SYNOPSIS...FISHER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...FISHER
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS NORTHERN INDIANA
1118 AM EST SAT JAN 3 2015
.SYNOPSIS...
ISSUED AT 943 AM EST SAT JAN 3 2015
LOW PRESSURE WILL MOVE OUT OF THE SOUTHWEST TOWARDS THE SOUTHERN
GREAT LAKES SATURDAY NIGHT. AREAS OF FREEZING RAIN AND SNOW WILL
CHANGE TO ALL RAIN BY EARLY AFTERNOON AS TEMPERATURES WARM ABOVE
FREEZING. HIGHS TODAY WILL RANGE FROM THE MIDDLE 30S NORTHWEST TO
NEAR 50 IN THE SOUTHEAST.
&&
.UPDATE...
ISSUED AT 1112 AM EST SAT JAN 3 2015
WHILE ICING HAS CALMED DOWN SIGNIFICANTLY BETWEEN ROUTE 24 AND 6...
TEMPERATURES IN MANY AREAS WERE STILL LINGERING BETWEEN 32 AND
33...MAKING FOR A SLOW MELT OFF. THE COLD RAIN FALLING ON ICY
SURFACES WAS STILL CAUSING SLIDE OFFS IN SEVERAL COUNTIES ALTHOUGH
CONDITIONS ARE SLOWLY IMPROVING. DECIDED BEST OPTION AT THIS POINT
WAS TO EXTEND THE HEADLINES A FEW HOURS. PULASKI AND FULTON COUNTY
REPORTED NO ISSUES SO ALLOWED THEM TO EXPIRE.
&&
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 403 AM EST SAT JAN 3 2015
IMPRESSIVE SRN STREAM SW TROUGH NOTED IN VAPOR THIS MORNING AND
BEGINNING TO LIFT OUT OF NM. THIS SYS WILL PHASE QUICKLY TONIGHT
W/NRN STREAM SW AMPLIFYING SEWD OUT OF THE NRN ROCKIES RESULTING IN
A RAPID NEWD EJECTION INTO SE CANADA BU SUN MORNING.
BROAD LOW-MID LVL MSTR SURGE JUST NOW GETTING UP INTO THE AREA
W/MORE VIGOROUS PRECIP DVLPMNT NOTED IN COMPOSITE RADAR IMAGERY BACK
ACRS CNTRL IL INTO WRN IN AND POSES AN ICING PROB EARLY ON
W/CURRENT SFC TEMPS IN THE UPR 20S. HWVR LL WAA QUITE INTENSE AS
NOTED OVR SRN IL/IN AND XPCD TO PROGRESS NWD THROUGH THIS MORNING.
GIVEN GOOD 00Z CONSENSUS W/CORRESPONDING RUC NOD TO SFC TEMPS CUT
BACK TIMING OF ADVISORY ACRS FAR SRN TIER OF COUNTIES YET WILL HOLD
W/REMAINDER OF ADVISORY SEGMENTS PER LTL XPCD SFC BASED WARMING
WILL OCCUR UNTIL MID-LT MORNING TIED TO DEEPER ERLY FLW TRAJECTORIES
AND MUCH LWR THETA-E AIR ORIGINATING FM OLD POLAR RIDGE.
REGARDLESS LL WAA WILL OVERWHELM SHALLOW SFC BASED COLD LYR BY LT
MORNING/ERLY AFTN S-N W/A DECENT RAIN EVENT XPCD ESP SE HALF. MID
LVL DRY SLOT WILL OVERSPREAD AREA LT THIS AFTN WEST AND OVERNIGHT
EAST ALTHOUGH TEMPS WILL FAIRLY MILD. EXCEPTION WILL BE FAR WEST
WHERE INTENSE LL CAA WING WILL BEGIN TO WRAP SEWD BEHIND DEPARTING
SFC LOW. LEFT OVER DEFORMATION ZONE AND RAPID INFLUX OF COLD AIR
WILL LEAD TO A RAPID CHG OVR TO ACCUMULATING SNOW FAR NW AND
EXPANDING SEWD DURING THE DAY AS MSTR FLUX OFF LK MI TAKES OFF. SHLD
SEE A PD OF ROBUST LK ENHANCEMENT THROUGHOUT THE NW HALF SUN AFTN
W/AT LEAST AN INCH OR TWO OF SNOWFALL XPCD.
&&
.LONG TERM...(SUNDAY NIGHT THROUGH FRIDAY)
ISSUED AT 403 AM EST SAT JAN 3 2015
BITTERLY COLD CONDITIONS CAN BE EXPECTED FOR MUCH OF THE LONG TERM
FORECAST DURING THE UPCOMING WEEK. STRONG COLD AIR ADVECTION WILL BE
OCCURRING AT THE START OF THIS PERIOD SUNDAY NIGHT. A STRONG UPPER
LEVEL DISTURBANCE WILL SUPPORT THE DEVELOPMENT OF A CLIPPER TYPE
SYSTEM THAT SHOULD RACE ACROSS THE AREA MONDAY NIGHT INTO EARLY
TUESDAY. FAVORED THE ECMWF RUN TO RUN CONSISTENCY AND HANDLING OF
THIS SYSTEM. TEMPERATURES WILL BE COLD ENOUGH FOR ALL SNOW...WITH 3
TO 6 INCHES EXPECTED BY MID DAY TUESDAY. GIVEN FRESH SNOW COVER AND
850 MB TEMPERATURES DROPPING WELL BELOW -20...OVERNIGHT LOWS SHOULD
BE ABLE TO FALL BELOW ZERO. LOWERED TEMPS TUESDAY NIGHT THROUGH
THURSDAY NIGHT IN THIS REGARD. WIND CHILLS WILL DIP TO -20 AT TIMES
DURING THE MIDDLE OF THE WEEK...WITH ADVISORY CONDITIONS LIKELY.
&&
.AVIATION...(FOR THE 12Z TAFS THROUGH 12Z SUNDAY MORNING)
ISSUED AT 654 AM EST SAT JAN 3 2015
(FOR THE 06Z TAFS THROUGH 06Z SATURDAY NIGHT)
ISSUED AT 134 AM EST SAT JAN 3 2015
LIFR CONDS TO PERSIST THROUGH THE PD AS WIDESPREAD PCPN CONTS
INADV OF POTENT SRN STREAM SW EJECTING OUT OF W TX THIS MORNING.
RAIN XPCD TO DIMINISH TO DZ LT THIS AFTERNOON AND MUCH OF TONIGHT
AS MID LVL DRY SLOT ENVELOPES THE TERMINALS. HWVR LAGGING MID LVL
DEFORMATION ZONE AND EWD WRAP OF INTENSE LL CAA WING ALG
W/ATTENDANT RAPID INFLUX OF LK MSTR FLUX WILL SPELL A PD OF
ACCUMLATING SNOWFALL SUNDAY.
&&
.IWX WATCHES/WARNINGS/ADVISORIES...
IN...WINTER WEATHER ADVISORY UNTIL 1 PM EST /NOON CST/ THIS AFTERNOON
FOR INZ003>005-008-009-012-014-016>018.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR INZ006-
007.
MI...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR MIZ077-
078.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR
MIZ079>081.
OH...WINTER WEATHER ADVISORY UNTIL 1 PM EST THIS AFTERNOON FOR OHZ004-
005-015-016.
WINTER WEATHER ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR OHZ001-
002.
LM...GALE WATCH FROM LATE TONIGHT THROUGH LATE SUNDAY NIGHT FOR
LMZ043-046.
&&
$$
UPDATE...FISHER
SYNOPSIS...FISHER
SHORT TERM...T
LONG TERM...SKIPPER
AVIATION...T
VISIT US AT WWW.WEATHER.GOV/IWX (ALL LOWER CASE)
FOLLOW US ON FACEBOOK...TWITTER...AND YOUTUBE AT:
WWW.FACEBOOK.COM/NWSNORTHERNINDIANA
WWW.TWITTER.COM/NWSIWX
WWW.YOUTUBE.COM/NWSNORTHERNINDIANA
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1254 PM EST Sat Jan 3 2015
...Forecast Update...
Issued at 154 PM EST Sat Jan 3 2015
The warm sector is now established over our area with temperatures
mainly ranging in the 55 to 60 range. Meanwhile, surface dew points
have also climbed into the low and mid 50s across the area. Our
relative lull in rain activity will persist another hour or two
before rain begins to fill back in from west to east. This will
occur ahead of potent energy beginning to eject out of the Red River
Valley. Our best forcing and precipitable water airmass (~1.5") will
arrive later this evening bringing widespread and occasionally heavy
rain to the area. Scattered embedded thunderstorms are also
expected.
Expect surface temperatures to slowly rise through the afternoon and
evening on the advective component, which will result in a slighly
unstable near surface across our southern CWA. The warm nose aloft
will prevent any real surface based destabilization, however gusty
winds could be mixed down to the surface in stronger showers and
storms. Will watch out for this overnight. The main threat will be a
local hydro problem due to the heavy rain, however widespread
problems are not anticipated. Will keep the 1 to 2 inches of rain
for the event forecast.
Previous Update...
Issued at 1000 AM EST Sat Jan 3 2015
The warm front is rapidly pushing northward at this hour and will be
through our northern CWA by early afternoon. Current obs show BWG at
56/54 with SDF at 46/44. Have seen a surge in showers and scattered
thunderstorms west of I-65 on the nose of the 50-60 knot low level
jet. These showers are basically signaling the warm frontal passage.
Did go ahead and increase thunder coverage to scattered as several
lightning strikes are showing up. Otherwise, current forecast is on
track and have only updated to reflect the latest temp, dewpoint,
wind and precipitation coverage trends.
.SHORT TERM (Now through Sunday)...
Issued at 300 AM EST Sat Jan 3 2015
Latest water vapor imagery with 500 mb RAP heights shows a deep
closed low across southern New Mexico while a ridge lies off the
Florida coast. In between, broad southwesterly flow has been
bringing a very moist and warm air mass into the Ohio Valley. At the
surface, high pressure is departing the region, allowing a warm
front to lift through TN and KY. Early morning temperatures range
from the upper 30s across southern IN to upper 40s across southern
KY.
As a surface low deepens to our west, plan on the warm front to lift
through Kentucky this morning and reach southern Indiana by early
afternoon. As the region becomes well within the warm sector,
temperatures will top out right around 60 degrees for much of the
area. Southern Kentucky locations are most likely to get into the
lower 60s. Southerly winds will increase throughout the day as well,
as soundings show a rather strong 850 mb jet of 55+ knots at about
2-3kft. An inversion in the lowest levels of the atmosphere should
keep these strong winds from mixing down, but it will still be gusty
at times today.
Precipitation this morning is expected to be on the lighter side,
mainly in the form of drizzle or light rain showers. Precipitation
chances/coverage will then steadily increase today as isentropic
upglide picks up and the region becomes more in the nose of the
850mb moisture transport axis. The greatest forcing/lift arrives by
mid/late afternoon through the evening hours as the cold front
swings through the state. Just ahead of this front, PWATs climb to
1.6 inches, which would be record values for this time of year for
BNA/ILN. Overall, a very moist air mass will be in place and though
the system is expected to be progressive, any training showers will
be capable of some moderate to locally heavy rainfall, especially
across the southern forecast area. Plan on rainfall amounts to range
from 1.5 to locally 2 inches across the area through Sunday morning.
Thunder chances are still included in the forecast as MUCAPE values
are progged to be around 500 J/kg this afternoon. Tonight`s low will
be quite mild, held up due to lingering precipitation and southerly
flow. Plan on readings to only into the mid 40s to lower 50s,
warmest east of I-65.
Cold air advection kicks in between midnight and sunrise Sunday,
resulting in a steady drop in temperatures during the day Sunday.
Morning readings in the mid 40s to near 50 are expected to fall into
the mid 30s to around 40 by mid/late afternoon. At the same time,
03.00z guidance continues to show lingering wrap around moisture
behind the departing low pressure system. As temperatures aloft
reach -8 to -10c, there may be enough saturation left to squeeze out
a few snowflakes across southern Indiana and northern Kentucky.
Otherwise, Sunday afternoon will be noticeably colder especially
given cloudy skies and a brisk west/northwest wind 15-20 mph, making
it feel more like the middle 20s at times.
.LONG TERM (Sunday night through Friday)...
Issued at 257 AM EST Sat Jan 3 2015
...Very Cold Temperatures and Wind Chills Mid-Week...
Canadian high pressure crossing the region Sunday night and Monday
will bring a quick shot of chilly air. Low clouds will likely hang
around for much of the night Sunday night, but should clear out just
in time to allow sunrise readings to drop into the 15-20 degree
range. We`ll have sunshine on Monday but the mercury will only
recover into the middle 20s in southern Indiana and around 30 in
Kentucky.
A quick moving clipper type system will zip by to our north Monday
night/Tuesday. The models have trended slightly faster and farther
south with this feature. Looking at atmospheric cross-sections,
even in the northernmost reaches of the LMK CWA around Madison,
there`s quite a bit of dry low level air Monday night, and then on
Tuesday when some low level moisture does move in it`s very
shallow. So, it still appears, at least for now, that measurable
precipitation is unlikely with this system. Will, however, include
a chance of flurries generally north of a Salem-Frankfort-Carlisle
line. Also, it should be noted that the GEM brings accumulating
snows to southern Indiana and northern Kentucky late Monday night.
This solution is an outlier, but these types of systems can do
surprising things sometimes, so it`s still something to keep an eye
on.
Strong Canadian high pressure will then invade Tuesday night through
Thursday. A tight surface pressure gradient on the nose of the
incoming high pressure Wednesday could give us some afternoon gusts
around 20 mph. With temperatures reaching only into the teens in
southern Indiana and the 20s in Kentucky, Wednesday will be a cold
day.
Then it will get worse. Lows Wednesday night, as the cold heart of
the Canadian high moves in, will be in the 0 to 5 degree range. Add
to that a northwest breeze around 10 mph and we could be looking at
advisory level wind chills of 10 to 15 degrees below zero as the
kids head out to the bus stops Thursday morning. Highs Thursday
afternoon will struggle to reach 20.
A cold front will sweep through the Ohio and Tennessee Valleys
Thursday night/Friday. However, the Gulf of Mexico will be
completely shut off by the departing mid-week high, so no
precipitation is expected.
&&
.AVIATION (18Z TAF Update)...
Issued at 1209 PM EST Sat Jan 3 2015
The warm front has lifted north of the TAF sites with all locations
currently experiencing steady to gusting south winds. With the
arrival of the warm sector, ceilings have improved to MVFR, however
will likely remain below fuel-alternate. Expect these improved
ceilings and relatively dry conditions to continue for a few hours
this afternoon before another surge in showers and thunderstorms
arrives by mid to late afternoon. A fairly prolonged period of
moderate to briefly heavy rain is then possible through the evening
hours, with SDF having the best chance at getting gapped by two
surges in moisture. Will continue to mention VCTS/CB through the
evening hours.
Otherwise, the bulk of the heavy rain ends around or just after
Midnight EST, with a cold front passing through thereafter. Winds
will swing around to WSW then almost westerly with gusty winds as
high as 30-35 mph at times on Sunday.
Only other issue will be ongoing LLWS threat below 2 K feet as a
50-60 knot low level jet streams overhead. This threat should
diminish as we head into the late afternoon hours as the jet swings
east.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....ZBT
Long Term......13
Aviation.......BJS
AREA FORECAST DISCUSSION
NWS LOUISVILLE KY
1211 PM EST Sat Jan 3 2015
...Updated Aviation Discussion...
...Forecast Update...
Issued at 1000 AM EST Fri Jan 2 2015
The warm front is rapidly pushing northward at this hour and will be
through our northern CWA by early afternoon. Current obs show BWG at
56/54 with SDF at 46/44. Have seen a surge in showers and scattered
thunderstorms west of I-65 on the nose of the 50-60 knot low level
jet. These showers are basically signaling the warm frontal passage.
Did go ahead and increase thunder coverage to scattered as several
lightning strikes are showing up. Otherwise, current forecast is on
track and have only updated to reflect the latest temp, dewpoint,
wind and precipitation coverage trends.
.SHORT TERM (Now through Sunday)...
Issued at 300 AM EST Sat Jan 3 2015
Latest water vapor imagery with 500 mb RAP heights shows a deep
closed low across southern New Mexico while a ridge lies off the
Florida coast. In between, broad southwesterly flow has been
bringing a very moist and warm air mass into the Ohio Valley. At the
surface, high pressure is departing the region, allowing a warm
front to lift through TN and KY. Early morning temperatures range
from the upper 30s across southern IN to upper 40s across southern
KY.
As a surface low deepens to our west, plan on the warm front to lift
through Kentucky this morning and reach southern Indiana by early
afternoon. As the region becomes well within the warm sector,
temperatures will top out right around 60 degrees for much of the
area. Southern Kentucky locations are most likely to get into the
lower 60s. Southerly winds will increase throughout the day as well,
as soundings show a rather strong 850 mb jet of 55+ knots at about
2-3kft. An inversion in the lowest levels of the atmosphere should
keep these strong winds from mixing down, but it will still be gusty
at times today.
Precipitation this morning is expected to be on the lighter side,
mainly in the form of drizzle or light rain showers. Precipitation
chances/coverage will then steadily increase today as isentropic
upglide picks up and the region becomes more in the nose of the
850mb moisture transport axis. The greatest forcing/lift arrives by
mid/late afternoon through the evening hours as the cold front
swings through the state. Just ahead of this front, PWATs climb to
1.6 inches, which would be record values for this time of year for
BNA/ILN. Overall, a very moist air mass will be in place and though
the system is expected to be progressive, any training showers will
be capable of some moderate to locally heavy rainfall, especially
across the southern forecast area. Plan on rainfall amounts to range
from 1.5 to locally 2 inches across the area through Sunday morning.
Thunder chances are still included in the forecast as MUCAPE values
are progged to be around 500 J/kg this afternoon. Tonight`s low will
be quite mild, held up due to lingering precipitation and southerly
flow. Plan on readings to only into the mid 40s to lower 50s,
warmest east of I-65.
Cold air advection kicks in between midnight and sunrise Sunday,
resulting in a steady drop in temperatures during the day Sunday.
Morning readings in the mid 40s to near 50 are expected to fall into
the mid 30s to around 40 by mid/late afternoon. At the same time,
03.00z guidance continues to show lingering wrap around moisture
behind the departing low pressure system. As temperatures aloft
reach -8 to -10c, there may be enough saturation left to squeeze out
a few snowflakes across southern Indiana and northern Kentucky.
Otherwise, Sunday afternoon will be noticeably colder especially
given cloudy skies and a brisk west/northwest wind 15-20 mph, making
it feel more like the middle 20s at times.
.LONG TERM (Sunday night through Friday)...
Issued at 257 AM EST Sat Jan 3 2015
...Very Cold Temperatures and Wind Chills Mid-Week...
Canadian high pressure crossing the region Sunday night and Monday
will bring a quick shot of chilly air. Low clouds will likely hang
around for much of the night Sunday night, but should clear out just
in time to allow sunrise readings to drop into the 15-20 degree
range. We`ll have sunshine on Monday but the mercury will only
recover into the middle 20s in southern Indiana and around 30 in
Kentucky.
A quick moving clipper type system will zip by to our north Monday
night/Tuesday. The models have trended slightly faster and farther
south with this feature. Looking at atmospheric cross-sections,
even in the northernmost reaches of the LMK CWA around Madison,
there`s quite a bit of dry low level air Monday night, and then on
Tuesday when some low level moisture does move in it`s very
shallow. So, it still appears, at least for now, that measurable
precipitation is unlikely with this system. Will, however, include
a chance of flurries generally north of a Salem-Frankfort-Carlisle
line. Also, it should be noted that the GEM brings accumulating
snows to southern Indiana and northern Kentucky late Monday night.
This solution is an outlier, but these types of systems can do
surprising things sometimes, so it`s still something to keep an eye
on.
Strong Canadian high pressure will then invade Tuesday night through
Thursday. A tight surface pressure gradient on the nose of the
incoming high pressure Wednesday could give us some afternoon gusts
around 20 mph. With temperatures reaching only into the teens in
southern Indiana and the 20s in Kentucky, Wednesday will be a cold
day.
Then it will get worse. Lows Wednesday night, as the cold heart of
the Canadian high moves in, will be in the 0 to 5 degree range. Add
to that a northwest breeze around 10 mph and we could be looking at
advisory level wind chills of 10 to 15 degrees below zero as the
kids head out to the bus stops Thursday morning. Highs Thursday
afternoon will struggle to reach 20.
A cold front will sweep through the Ohio and Tennessee Valleys
Thursday night/Friday. However, the Gulf of Mexico will be
completely shut off by the departing mid-week high, so no
precipitation is expected.
&&
.AVIATION (18Z TAF Update)...
Issued at 1209 PM EST Sat Jan 3 2015
The warm front has lifted north of the TAF sites with all locations
currently experiencing steady to gusting south winds. With the
arrival of the warm sector, ceilings have improved to MVFR, however
will likely remain below fuel-alternate. Expect these improved
ceilings and relatively dry conditions to continue for a few hours
this afternoon before another surge in showers and thunderstorms
arrives by mid to late afternoon. A fairly prolonged period of
moderate to briefly heavy rain is then possible through the evening
hours, with SDF having the best chance at getting gapped by two
surges in moisture. Will continue to mention VCTS/CB through the
evening hours.
Otherwise, the bulk of the heavy rain ends around or just after
Midnight EST, with a cold front passing through thereafter. Winds
will swing around to WSW then almost westerly with gusty winds as
high as 30-35 mph at times on Sunday.
Only other issue will be ongoing LLWS threat below 2 K feet as a
50-60 knot low level jet streams overhead. This threat should
diminish as we head into the late afternoon hours as the jet swings
east.
&&
.LMK WATCHES/WARNINGS/ADVISORIES...
KY...NONE.
IN...NONE.
&&
$$
Update.........BJS
Short Term.....ZBT
Long Term......13
Aviation.......BJS
AREA FORECAST DISCUSSION...UPDATED
NWS SHREVEPORT LA
1118 AM CST SAT JAN 3 2015
.DISCUSSION...
BAND OF CONVECTION WILL CONTINUE TO GRADUALLY MOVE EWD THROUGH THE
REMAINDER OF THE DAY. PRECIP WILL GENERALLY BE CONFINED EAST OF A
LINE FROM TOLEDO BEND RESERVOIR...TO MINDEN LA...TO EL DORADO AR.
HAVE ADJUSTED POPS BASED ON LATEST RADAR TRENDS AND REMOVED RAIN
CHANCES BACK TO THE WEST. TRIMMED BACK THE FLASH FLOOD WATCH TO
COINCIDE TO THE BACK EDGE OF THE CONVECTION. /09/
&&
.PREV DISCUSSION... /ISSUED 624 AM CST SAT JAN 3 2015/
AVIATION...
FOR THE 12/03Z TAFS...WIDESPREAD SHWRS AND SOME EMBEDDED TSTMS
WILL PERSIST THROUGH THE FIRST HALF OF THE TAF PERIOD FOR MOST OF
OUR AREA TERMINALS...GRADUALLY ENDING FROM WEST TO EAST LATER
TODAY AS A COLD FRONT SWEEPS ACROSS THE REGION. LOW CLOUDS WILL
LAG BEHIND THE FRONT SO MVFR/IFR CIGS WILL LINGER THROUGH THE
AFTERNOON AND POSSIBLY THE EARLY EVENING HOURS AT OUR ERN TAF
SITES. VSBYS WILL ALSO REMAIN IN FLUX WITH THE RAINFALL AND
RESULTING BR...GENERALLY IN THE MVFR RANGE BUT CANNOT RULE OUT
SOME IFR PERIODS WITH HEAVIER RAINFALL. WINDS WILL BE MOSTLY
VARIABLE AVERAGING AROUND 10 KTS WITH HIGHER GUSTS IN CONVECTION
AND EXPECT VEERING TO A SW DIRECTION LATER THIS MORNING AHEAD OF
THE COLD FRONT...EVENTUALLY BECOMING W AND THEN NW TOWARD THE END
OF THE PERIOD AS THE FRONT ADVANCES EWRD WITH CONDITIONS IMPROVING
TO VFR AROUND 04/00Z AND SHORTLY THEREAFTER AT ELD/MLU. /19/
PREV DISCUSSION... /ISSUED 549 AM CST SAT JAN 3 2015/
DISCUSSION...
SORRY FOR THE LATE PRODUCTS...AS SOME OF THESE STORMS DECIDED TO
GO ROGUE ON US THIS MORNING AS THE STORMS ROLLED INTO SHV/DEEP E
TX/WCNTRL LA. BUT THE LEADING EDGE OF THE STORMS/GUSTY WINDS HAVE
ACCELERATED E QUICKLY ACROSS NCNTRL LA AS OF 11Z...MUCH FASTER
THAN THE 00Z NAM/GFS. THE HRRR HAS INITIALIZED ON THIS WELL...AS
HAVE HAD TO MAKE A COUPLE OF ADDITIONAL CHANGES TO THE TEMPS TODAY
AS THIS SHALLOW/COLDER AIR QUICKLY OVERTAKES THE WARM SECTOR
ACROSS NCNTRL LA. EARLIER THIS MORNING AS OF 06Z...THERE WAS A SFC
LOW IN VC OF LFK...BUT THIS HAS BECOME ILL-DEFINED AS THE
CONVECTION ACCELERATED E...WITH WHAT LIMITED OF A SVR THREAT
DIMINISHES FURTHER THIS MORNING AS THIS SFC TROUGH QUICKLY SPREADS
E TOWARDS THE MS RIVER. WILL STILL HAVE TO CONTEND WITH LOCALLY
HEAVY RAINFALL THIS MORNING/EARLY AFTERNOON ACROSS EXTREME ERN
TX/N LA/SCNTRL AR...WHERE WIDESPREAD 3-5+ INCHES OF RAIN HAS
FALLEN IN THE LAST WEEK...AND PW/S ARE FORECAST TO APPROACH NEAR
RECORD VALUES FOR JANUARY /PER CLIMATOLOGY/. BELIEVE THAT THE
HEAVY RAINFALL THREAT WILL DIMINISH AFTER 18Z AS THE STRONGER
STORMS EXIT THE AREA...BUT WILL ALLOW THE CURRENT FLASH FLOOD
WATCH TO EXPIRE AS SCHEDULED AT 22Z.
SHOULD SEE THE STRATOCU LINGER THROUGH THE AFTERNOON...ALTHOUGH
SOME BREAKS WILL BE POSSIBLE LATER IN THE DAY ACROSS E TX...WHICH
WOULD RESULT IN A LITTLE BETTER WARMING THAN AREAS FARTHER N AND
E. GIVEN THE FASTER MOVEMENT OF THE SFC TROUGH THIS MORNING...HAVE
ALSO TRIMMED BACK MAX TEMPS OVER EXTREME NW LA...WITH MAX TEMPS
FARTHER E ACROSS NCNTRL LA OCCURRING BY DAYBREAK WITH TEMPS
FALLING DURING THE DAY.
THE SHORT TERM PROGS ARE STILL IN AGREEMENT WITH OUR ARCTIC FRONT
MOVING INTO THE REGION AFTER 06Z...DEEPENING LATE THROUGH SUNDAY
AS A 1040MB SFC RIDGE BUILDS E ACROSS THE CNTRL/SRN PLAINS. SHOULD
SEE THE FIRST FREEZE OF THE NEW YEAR MONDAY MORNING...AS THE SKY
CLEARS AND WINDS DECOUPLE IN THE VERY COLD/DRY AIR MASS BUILDING
IN. A SECOND ARCTIC FRONT WILL QUICKLY BUILD SE INTO THE AREA
TUESDAY AHEAD OF THE NEXT LONGWAVE TO DIVE SE ACROSS THE CNTRL/ERN
CONUS...WITH WHAT SHOULD BE THE COLDEST TEMPS SO FAR THIS WINTER
SEASON...WITH SE OK/NRN SECTIONS OF SW AR POSSIBLY FALLING INTO
THE TEENS...WITH THE REMAINDER OF THE REGION WELL INTO THE 20S.
HAVE KEPT THE REMAINDER OF THE EXTENDED DRY GIVEN THE DRY NW FLOW
ALOFT...ALTHOUGH THE POTENTIAL FOR -SHRA APPEARS TO INCREASE NEXT
WEEKEND AS A SHORTWAVE BEGINS TO OPEN UP AND SHIFT E ACROSS THE
SRN PLAINS...RESULTING IN ENHANCED OVERRUNNING AS THE ARCTIC AIR
MASS BEGINS TO MODIFY.
PRELIMS TO FOLLOW BELOW...
15
&&
.PRELIMINARY POINT TEMPS/POPS...
SHV 54 39 46 27 46 / 20 0 0 0 0
MLU 66 42 49 28 46 / 100 30 0 0 0
DEQ 51 32 40 21 41 / 10 10 0 0 0
TXK 53 37 41 23 42 / 20 10 0 0 0
ELD 57 39 46 24 43 / 100 10 0 0 0
TYR 53 34 44 25 45 / 10 0 0 0 0
GGG 53 37 44 25 45 / 10 0 0 0 0
LFK 57 37 50 27 48 / 20 0 0 0 0
&&
.SHV WATCHES/WARNINGS/ADVISORIES...
AR...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: ARZ073.
LA...FLASH FLOOD WATCH UNTIL 4 PM CST THIS AFTERNOON FOR THE
FOLLOWING ZONES: LAZ004>006-011>014-017>022.
OK...NONE.
TX...NONE.
&&
$$
09
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
427 PM EST SAT JAN 3 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 335 PM EST SAT JAN 3 2015
UPPER MICHIGAN IS CURRENTLY BETWEEN THE STRONGER AND PRECIPITATION
PRODUCING SURFACE/UPPER LEVEL FEATURES. THE REMNANTS OF THE SURFACE
LOW THAT MOVED THROUGH MINNESOTA LAST NIGHT HAS LEFT A SURFACE
TROUGH OVER WESTERN LAKE SUPERIOR THIS AFTERNOON. ON THE NORTHWEST
SIDE OF THAT TROUGH...SNOW HAS BEEN FALLING FOR MUCH OF THE DAY IN
THE MINNESOTA ARROWHEAD IN ASSOCIATION WITH THE MID LEVEL Q-VECTOR
CONVERGENCE AND THE RIGHT REAR OF THE SPLIT NORTHERN STREAM JET
STREAK. FARTHER SOUTH...WATER VAPOR IMAGERY SHOWS A STRONG UPPER
WAVE LIFTING NORTHEAST OUT OF THE SOUTHERN PLAINS...WHILE A SECOND
WEAKER WAVE IS NEARING IT FROM THE NORTHWEST IN COLORADO. BETWEEN
THESE TWO FEATURES AND BEHIND THE SHORTWAVE THAT MOVED THROUGH
SOUTHEAST UPPER MICHIGAN LAST NIGHT AND THIS MORNING (PRODUCING
1-1.5IN OF SNOW NEAR LAKE MICHIGAN)...CLOUDY SKIES PREVAIL OVER
UPPER MICHIGAN. THIS IS DUE TO THE LINGERING LOW LEVEL MOISTURE
TRAPPED BELOW THE DRYING ALOFT BEHIND THE SHORTWAVE. ONCE THE DEEPER
MOISTURE DEPARTED WITH THE SHORTWAVE...SAW A TRANSITION TO BR AND
REDUCED VISIBILITIES ON THE AUTOMATED STATIONS. CALLING AROUND TO
THE SOUTHERN PART OF THE CWA HAS SHOWN A TRANSITION FROM WEST TO
EAST ALONG THE WISCONSIN BORDER TO FREEZING DRIZZLE OVER THE LAST
COUPLE OF HOURS. FARTHER NORTH AT OUR OFFICE...WE HAVE BEEN JUST
SEEING A FEW FLURRIES DUE TO CLOUD LAYER BEING RIGHT AT THE EDGE OF
THE MORE FAVORABLE ICE CRYSTAL REGION. EXPECT THIS
BORDERLINE/LIMITED CONDITION TO CONTINUE OVER THE SOUTH CENTRAL AND
SOUTHEASTERN CWA INTO THE EVENING HOURS AND WILL SHOW THE POTENTIAL
FOR FREEZING DRIZZLE IN THE FORECAST. WILL ISSUE AN SPS TO
HIGHLIGHT THE FREEZING DRIZZLE AND UNTREATED ROADS BECOMING
SLIPPERY FOR THE AREAS NOT CURRENTLY COVERED BY THE ADVISORY.
OTHERWISE...EXPECT THE FREEZING DRIZZLE TO DIMINISH FROM WEST TO
EAST THIS EVENING AS THE DEEPER MOISTURE FROM THE FEATURE OVER
WESTERN LAKE SUPERIOR MOVES OVER THE U.P. TONIGHT.
THE STRONG TROUGH IN THE SOUTHERN PLAINS WILL LIFT NORTHEAST
THROUGH THE LOWER GREAT LAKES REGION TONIGHT...STRENGTHENING A LOW
FROM 1007MB OVER SOUTHERN ILLINOIS TO 998MB BETWEEN LAKE
ERIE/ONTARIO AT 12Z SUNDAY. AS THAT OCCURS...THE MID LEVEL TROUGH
ASSOCIATED WITH THE SURFACE TROUGH OVER THE WESTERN LAKE WILL
DROP SOUTHEAST ACROSS UPPER MICHIGAN THROUGH SUNDAY MORNING. THE
SYNOPTIC LIQUID EQUIVALENT PRECIPITATION (TIED TO THE 850-650MB
FGEN) LOOKS TO BE IN THE 0.10-0.15 INCH RANGE FOR MOST OF THE CWA
THROUGH SUNDAY MORNING. SNOW RATIOS INITIALLY WILL LIKELY BE AROUND
10-15 TO 1 AS THERE IS STILL A PERIOD OF THE CLOUD BEING ABOVE/BELOW
THE DGZ. BUT THERE WILL LIKELY BE A TRANSITION TO A BRIEF (2-4HR)
PERIOD LATE TONIGHT INTO SUNDAY MORNING WHEN THE LOWEST 10-12KFT OF
THE ATMOSPHERE IS WITHIN THE DGZ. THIS WOULD LEAD TO A PERIOD OF
FLUFFIER SNOW AND RATIOS RISING TOWARDS OR EVEN ABOVE 20-1. DON/T
FEEL COMFORTABLE GOING MUCH ABOVE THAT DUE TO THE FORCING THAT IS
EXPECTED ABOVE THE DGZ. THUS...SYNOPTIC SNOW WOULD AMOUNT TO
1 TO 2.5-3.0 INCHES...WITH THE GREATEST OVER THE WEST HALF. BUT AS
IS NORMALLY THE CASE WITH LAKE SUPERIOR AND OUR TERRAIN
INFLUENCES...THAT ISN/T THE COMPLETE STORY ON THE SNOWFALL.
MUCH COLDER AIR WILL SURGE INTO THE AREA TONIGHT BEHIND THE
850-700MB TROUGH...WITH 850MB TEMPS FALLING FROM 19Z RAP ANALYZED
OF -5C TO -7C TO -19C EAST AND -24C WEST BY 18Z SUNDAY. THIS WILL
LEAD TO LAKE ENHANCEMENT DEVELOPING FROM WEST TO EAST TONIGHT AND
THEN TRANSITIONING TO PURE LAKE EFFECT AS THE DEEPER MOISTURE
DEPARTS ON SUNDAY. THE HELP FROM THE LAKE WILL BE FOCUSED IN THE
NORTHERLY WIND LOCATIONS OF THE WEST AND NORTH CENTRAL TONIGHT AND
THEN WINDS BACK TO THE NORTHWEST SUNDAY MORNING AND WEST-NORTHWEST
BY SUNDAY EVENING. WITH THAT COLD AIR SURGING IN...THE CLOUD LAYER
ON SUNDAY WILL TRANSITION TO BEING ABOVE THE DGZ. THUS...WOULD
EXPECT A TRANSITION OF THE SNOWFLAKES TO COLUMNS/PLATES AND LOWER
SNOW RATIOS BELOW 20-1. CONTINUED THE TREND TOWARDS THE HIGH
RESOLUTION MODELS FOR QPF AMOUNTS TONIGHT/SUNDAY IN THE
LAKE/TERRAIN ENHANCED AREAS (0.25-0.40 IN). THIS LEADS TO SNOWFALL
AMOUNTS OF 3-5 INCHES OF SNOW TONIGHT OVER THE FAVORED NORTH WIND
AREAS OVER THE WEST AND NORTH CENTRAL. THERE COULD BE SOME
LOCALIZED HIGHER AMOUNTS TOWARDS 5.5-6.0 INCHES. THE LOWERING RATIOS
ON SUNDAY WILL LEAD TO LOWER AMOUNTS OVER THE WEST...BUT COULD
STILL SEE 2-5 INCHES IN THE FAVORED NORTHWEST WINDS AREAS OVER THE
EAST. IN ADDITION TO THE SNOW...WINDS WILL QUICKLY INCREASE FROM
NORTHWEST TO SOUTHEAST TONIGHT...WITH GUSTS BETWEEN 30 TO 45 MPH
(HIGHEST NEAR LAKE SUPERIOR). THAT WILL LEAD TO BLOWING SNOW AND
COMBINED WITH THE EXPECTED SNOW...SHOULD SEE VISIBILITIES
FREQUENTLY REDUCED BELOW ONE MILE OVER THE NORTHERN HALF OF THE
CWA. THUS...THINK THE GOING ADVISORY LOOKS GOOD WITH THE FORECASTED
SNOWFALL AMOUNTS AND IMPACT WITH THE REDUCED VISIBILITIES FROM
BLOWING SNOW. AS MENTIONED ABOVE...THINK SOME HIGHER TERRAIN
LOCATIONS FLIRTING WITH 12HR WARNING SNOWFALL AMOUNTS (DUE TO THE
OVERALL AVERAGE SNOW RATIO BEING JUST BELOW OUR LAKE EFFECT WARNING
CRITERIA). BUT WITH MUCH OF THE SNOW FALLING ON A WEEKEND
OVERNIGHT AND THE EXPECTED COVERAGE FAIRLY LOCALIZED...WILL KEEP
THE ADVISORY IN PLACE.
.LONG TERM...(SUNDAY NIGHT THROUGH SATURDAY)
ISSUED AT 426 PM EST SAT JAN 3 2015
TROUGHING AND WELL BELOW NORMAL TEMPERATURES DOMINATES THE WEATHER
PATTERN FOR THE FIRST FULL WEEK OF 2015 OVER NORTH AMERICA. STILL
INDICTIONS THAT A TRANSITION TO ZONAL FLOW AND ABOVE NORMAL TEMPS
DEVELOPS BY MID MONTH. ECMWF INDICATES THIS PATTERN SWITCH MAY OCCUR
AS EARLY AS NEXT WEEKEND WHILE GFS IS A BIT SLOWER. WOULD TEND TO
THINK IT MAY TAKE LONGER GIVEN THE DEGREE OF COLD AIR OVER THE
REGION AS LATE AS FRIDAY. EITHER WAY THIS UPCOMING WEEK WILL BE A
VERY COLD ONE WITH SUBZERO HIGHS ON SOME DAYS AND DANGEROUSLY LOW
WIND CHILLS. PATTERN DOES NOT HOLD MUCH OPPORTUNITY FOR WIDESPREAD
SNOW...BUT MAINLY LAKE EFFECT SNOW FOR AREAS NEAR LK SUPERIOR
FAVORED BY NORTHWEST OR WEST WINDS.
LES IN NW FLOW AREAS NEAR LAKE SUPERIOR WILL BE ONGOING SUNDAY NIGHT
IN WAKE OF THE LOW PRESSURE SYSTEM MOVING OVER THE CNTRL GREAT LAKES
ON SUNDAY. THOUGH MAIN SHORTWAVE AND SFC TROUGH WILL BE EAST OF THE
AREA...MULTIPLE SMALLER SHORTWAVES MAY PROVIDE SLIGHT ENHANCEMENT TO
LES. OVER-WATER INSTABILITY EASILY EXTREME WITH H85 TEMPS DOWN TO
-26C TO -28C AND 950MB TEMPS -22C TO -27C. LK SUPERIOR TEMPS STILL
+2C TO 3C. INVERSION HEIGHTS TOP OUT AT THE END OF THE FETCH OVER
EASTERN LK SUPERIOR 6-7KFT. DUE TO SUCH COLD AIR THE SLR/S WILL BE
WELL BLO 20:1 AS SNOWFLAKES WITHIN CONVECTIVE LAYER WILL BE PLATES
AND COLUMNS INSTEAD OF DENDRITES. RESULT IS A SNOW THAT WILL NOT
ADD UP MUCH IN TERMS OF ACCUMULATIONS...BUT WILL BE GOOD AT REDUCING
VISIBILITY. BASED ON 925MB WINDS...STEADIER LES EXPECTED SUNDAY
NIGHT AND MONDAY OVER THE KEWEENAW PENINSULA AND FOR THE SNOW BELTS
EAST OF MARQUETTE. POSSIBLE THAT ADDITIONAL ADVISORIES OR EXTENSION
OF CURRENT WINTER WEATHER ADVISORIES FOR LES WITH LOW VSBY AND GUSTY
WINDS MAY BE NEEDED INTO MONDAY...BUT WILL LET LATER SHIFTS EVALUATE
THIS ONCE WE GET THROUGH THE CURRENT ADVISORIES POSTED INTO SUNDAY.
OTHER THAN THE LES...THE COLD AND DANGEROUS WIND CHILLS WILL BE THE
MAIN STORY OVER THE CWA TO START THE WEEK. SFC RIDGE AXIS OVER THE
NORTHERN TO CENTRAL PLAINS AND LAKE INDUCED TROUGH WILL LEAD TO
MODEST PRESSURE GRADIENT OVER UPR MICHIGAN SUNDAY NIGHT INTO MONDAY
MORNING...BUT THERE IS NOT MUCH OF A LOW-LEVEL WIND MAX OVERHEAD AT
THAT TIME. EVEN SO...IT WILL NOT TAKE MUCH WIND TO PRODUCE NEAR
WARNING WIND CHILLS AS SFC TEMPS ARE EXPECTED TO BE -15F OR EVEN
-20F OVER FAR SW UPR MICHIGAN. STRONGER WINDS OF 10-15 MPH MAY BE
CLOSER TO LAKE INDUCED TROUGHING ALONG SOUTH SHORE OF LK SUPERIOR
WHERE TEMPS SHOULD BE MORE IN THE SINGLE DIGITS BLO ZERO. WIND CHILL
ADVISORIES WILL BE NEEDED FOR WEST HALF OF UPR MICHIGAN SUNDAY NIGHT
AND MONDAY...WITH POSSIBLE WARNINGS OVER FAR SW UPR MICHIGAN. COORD
WITH DLH AND GRB AND ISSUED A WIND CHILL WATCH FOR AREAS OF SW UPR
MICHIGAN /GOGEBIC...IRON...DICKINSON/ WHERE WARNING CRITERIA OF -35F
HAS BEST CHANCE OF OCCURRING.
LATER IN THE DAY ON MONDAY...A CLIPPER SHORTWAVE DIVING SE OUT OF
BRITISH COLUMBIA AND ALBERTA WILL SPREAD SNOW OVER THE NORTHERN
PLAINS AND EVENTUALLY THIS SNOW WILL MAKE IT TO THE WESTERN GREAT
LAKES ON MONDAY NIGHT. ATTM IT APPEARS THAT BULK OF THIS SYSTEM WILL
MISS UPR MICHIGAN. BY MONDAY AFTN AND MONDAY EVENING THOUGH...WINDS
BACKING WSW-SW AHEAD OF MORE NORTHERN STREAM SHORTWAVE AND COLD
FRONT DIVING SOUTHWARD OVER MANITOBA SHOULD PUSH THE LES OVER FAR
NORTHERN KEWEENAW AND OFFSHORE FM THE SNOW BELTS EAST OF MARQUETTE.
DOES NOT APPEAR WINDS BACK ENOUGH ON LK MICHIGAN TO BRING LES OFF LK
MICHIGAN INTO PLAY FOR SE CWA. LES STAYS MAINLY IN THE W FLOW AREAS
ON MONDAY NIGHT...BUT AS THE SHORTWAVE/COLD FRONT ARRIVE ON TUESDAY
WILL PUSH BACK TO NW FLOW AREAS NEAR LK SUPERIOR. SOUNDINGS SHOW
SHORTWAVE AND FRONT HAS MORE OF AN AFFECT ON THE LES AS INVERSIONS
RISE UP TO 10 KFT AS MORE COLD AIR WITH H85 TEMPS DOWN BLO -26C
SLIDES OVER THE UPPER GREAT LAKES. LIKE MONDAY...ALL OF CONVECTIVE
DEPTH IS AT TEMPS LOWER THAN DGZ...SO SMALL FLAKE SIZE AND LOW SLR/S.
NW WINDS IN MIXED LAYER NEAR 30 KTS...SO BLSN MORE OF AN ISSUE THAN
MONDAY. OVERALL THE POOR VSBY WILL CONINUE TO BE MAIN HAZARD FM THE
LES. AIR TEMPS MAY NOT BE QUITE AS COLD AS MONDAY MORNING BUT COLD
FRONT AND PRESSURE GRADIENT LOOKS MORE ROBUST. LIKELY LOOKING AT
ANOTHER ROUND OF WIND CHILL ADVISORIES FOR WEST HALF OF CWA LATE
TUESDAY NIGHT INTO WEDNESDAY MORNING. PROBABLY SHOULD STAY AWAY FM
ANY WARNING CRITERIA THOUGH.
COLD FRONT MOVES ON THROUGH WEDNESDAY AND 1045-1050MB HIGH PRESSURE
RIDGE OVER NORTHERN PLAINS PUSHES TO SOUTHERN PLAINS AND OHIO
VALLEY. IN RESPONSE...BLYR WINDS BACK MORE WNW-W BY WEDNESDAY
EVENING SO THE LES WILL IN TURN SHIFT AROUND AND NOT STAY PUT IN ANY
ONE PLACE TOO LONG. BEST CHANCE FOR MODERATE ACCUMS AND PERSISTENT
LOW VSBY WILL BE AT THE END OF THE FETCH IN THE SNOW BELTS TO EAST
OF MARQUETTE. ANOTHER COLD FRONT WILL DROP ACROSS UPPER LAKES ON
THURSDAY. YET ANOTHER SURGE OF H85 TEMPS BLO -25C WILL DESCEND ON
THE AREA. AHEAD OF THE COLD FRONT FOR THURSDAY...WEST WINDS MAY BE
STIFF LATE WEDNESDAY NIGHT INTO THURSDAY MORNING. THE STRONGER WINDS
ALONG WITH TEMPS LESS THAN 10 BLO WILL PROBABLY RESULT IN MORE WIND
CHILL ADVISORIES FOR MOST OF THE WEST HALF ON THURSDAY MORNING.
PROBABLY ARE GETTING THE THEME BY NOW. THIS WEEK LOOKS QUITE BRUTAL
IN TERMS OF THE PROLONGED DURATION OF BITTER COLD AND WIND CHILL
ISSUES. THIS WILL MAKE THE THAW EXPECTED FOR MID JANUARY FEEL ALL
THE MORE BETTER.
NW FLOW LES TO CLOSE THE WEEK AND INTO NEXT SATURDAY. THE NW WINDS
WILL RESULT IN MORE LAKE MODERATION SO TEMPS WILL BE PROBABLY BE
WARM ENOUGH TO LIMIT THE NEED OF ANY MORE WIND CHILL HEADLINES ON
FRIDAY MORNING OR SATURDAY MORNING. COULD SEE SWATH OF LGT SNOW
SWEEP OVER THE REGION NEXT WEEKEND AS THE WARM AIR BEGINS TO PUSH
OVER THE REGION ATOP OF SLOWLY RETREATING COLD AIR NEAR SFC.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1250 PM EST SAT JAN 3 2015
UPPER MICHIGAN IS BETWEEN FEATURES AT THIS TIME...WITH VFR
CONDITIONS AT KIWD/KCMX AND IFR CEILINGS AND SOME FOG/SNOW/DRIZZLE
AT KSAW. THESE CONDITIONS WILL STAY FAIRLY STEADY STATE OVER THE
NEXT COUPLE-FEW HOURS...THEN WILL SEE CONDITIONS DETERIORATING FROM
WEST TO EAST THIS EVENING AS THE AREA OF SNOW IN THE MINNESOTA
ARROWHEAD MOVES INTO THE AREA. WITH ALL THREE TAF SITES HELPED BY
UPSLOPE WINDS AND LAKE ENHANCEMENT...BROUGHT THEIR VISIBILITIES
BELOW ALT LANDING MINS DURING THE OVERNIGHT HOURS WHEN THE
STRONGEST SNOW WILL BE MOVING THROUGH. GUSTY WINDS WILL ALSO CREATE
BLOWING SNOW OVERNIGHT INTO SUNDAY...WHICH COULD LEAD TO A
TRANSITION TO VERTICAL VISIBILITIES UNDER 500FT AT TIMES. THE
WIDESPREAD SNOW WILL DEPART LATE TONIGHT INTO EARLY SUNDAY
MORNING...LEAVING LAKE ENHANCED/EFFECT SNOW AT ALL THREE SITES
SUNDAY MORNING UNDER NORTHWEST WINDS. KEPT VISIBILITIES DOWN DURING
THAT PERIOD DUE TO THE SMALLER SNOW FLAKES BEING EFFICIENT REDUCERS
OF VISIBILITY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 335 PM EST SAT JAN 3 2015
THE BUSY MARINE WEATHER WE HAVE HAD RECENTLY WILL CONTINUE WITH
GALES AND HEAVY FREEZING SPRAY RETURNING AND HOISTED GALE WARNINGS
AND HEAVY FREEZING SPRAY WARNINGS FOR LATE TONIGHT INTO SUNDAY. A
COUPLE MORE GALE EVENTS ARE POSSIBLE ON LAKE SUPERIOR TUESDAY NIGHT
AND WEDNESDAY MORNING AND AGAIN FOR THURSDAY NIGHT WITH NORTHWEST
GALES EXPECTED THEN. FREEZING SPRAY WILL ALSO BE A PROBLEM THROUGH
MOST OF THIS FORECAST PERIOD.
WINDS SHIFT TO THE NORTH LATE TONIGHT AS THE NORTHERN PLAINS
TROUGH MERGES WITH ANOTHER LOW PRESSURE SYSTEM LIFTING NORTH OVER
THE CENTRAL GREAT LAKES. NORTH GALES TO 35-40 KTS ARE EXPECTED
SUNDAY ESPECIALLY OVER THE EASTERN HALF OF LK SUPERIOR. HEAVY
FREEZING SPRAY WILL DEVELOP TONIGHT AS ARCTIC AIR POURS OVER
LK SUPERIOR. GALES SHOULD DIMINISH BY LATE SUNDAY NIGHT...BUT NW-W
WINDS TO 30 KTS AND HEAVY FREEZING SPRAY WILL LINGER THROUGH MONDAY.
W-SW WINDS TO 25 KTS ON TUESDAY AS A CLIPPER SYSTEM CROSSES UPPER
GREAT LAKES. BEHIND THE CLIPPER...PLAN ON ANOTHER ROUND OF NW GALES
AND HEAVY FREEZING SPRAY THROUGH WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY UNTIL 7 PM EST /6 PM CST/ SUNDAY FOR
MIZ001>003-009-084.
WINTER WEATHER ADVISORY FROM 4 AM TO 7 PM EST SUNDAY FOR MIZ006-
007-085.
LAKESHORE FLOOD ADVISORY FROM 1 AM TO 1 PM EST SUNDAY FOR
MIZ001>003.
WIND CHILL WATCH FROM SUNDAY EVENING THROUGH MONDAY MORNING FOR
MIZ009>011.
LAKESHORE FLOOD ADVISORY FROM 7 AM TO 7 PM EST SUNDAY FOR
MIZ005>007.
WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST SUNDAY FOR MIZ004-
005.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM SUNDAY TO 1 AM EST FRIDAY
FOR LSZ251-267.
GALE WARNING FROM 4 AM SUNDAY TO 7 AM EST MONDAY FOR LSZ249>251-
267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 1 AM EST FRIDAY
FOR LSZ249-250-266.
GALE WARNING FROM 1 AM SUNDAY TO 7 AM EST MONDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 1 AM EST /MIDNIGHT CST/ FRIDAY FOR LSZ162-
240>248-263>265.
GALE WARNING FROM 9 PM EST /8 PM CST/ THIS EVENING TO 7 AM EST
/6 AM CST/ MONDAY FOR LSZ240>248-263>265.
LAKE MICHIGAN...
GALE WARNING FROM 7 AM TO 7 PM EST SUNDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...JLA
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
335 PM EST SAT JAN 3 2015
.SHORT TERM...(THIS EVENING THROUGH SUNDAY)
ISSUED AT 335 PM EST SAT JAN 3 2015
UPPER MICHIGAN IS CURRENTLY BETWEEN THE STRONGER AND PRECIPITATION
PRODUCING SURFACE/UPPER LEVEL FEATURES. THE REMNANTS OF THE SURFACE
LOW THAT MOVED THROUGH MINNESOTA LAST NIGHT HAS LEFT A SURFACE
TROUGH OVER WESTERN LAKE SUPERIOR THIS AFTERNOON. ON THE NORTHWEST
SIDE OF THAT TROUGH...SNOW HAS BEEN FALLING FOR MUCH OF THE DAY IN
THE MINNESOTA ARROWHEAD IN ASSOCIATION WITH THE MID LEVEL Q-VECTOR
CONVERGENCE AND THE RIGHT REAR OF THE SPLIT NORTHERN STREAM JET
STREAK. FARTHER SOUTH...WATER VAPOR IMAGERY SHOWS A STRONG UPPER
WAVE LIFTING NORTHEAST OUT OF THE SOUTHERN PLAINS...WHILE A SECOND
WEAKER WAVE IS NEARING IT FROM THE NORTHWEST IN COLORADO. BETWEEN
THESE TWO FEATURES AND BEHIND THE SHORTWAVE THAT MOVED THROUGH
SOUTHEAST UPPER MICHIGAN LAST NIGHT AND THIS MORNING (PRODUCING
1-1.5IN OF SNOW NEAR LAKE MICHIGAN)...CLOUDY SKIES PREVAIL OVER
UPPER MICHIGAN. THIS IS DUE TO THE LINGERING LOW LEVEL MOISTURE
TRAPPED BELOW THE DRYING ALOFT BEHIND THE SHORTWAVE. ONCE THE DEEPER
MOISTURE DEPARTED WITH THE SHORTWAVE...SAW A TRANSITION TO BR AND
REDUCED VISIBILITIES ON THE AUTOMATED STATIONS. CALLING AROUND TO
THE SOUTHERN PART OF THE CWA HAS SHOWN A TRANSITION FROM WEST TO
EAST ALONG THE WISCONSIN BORDER TO FREEZING DRIZZLE OVER THE LAST
COUPLE OF HOURS. FARTHER NORTH AT OUR OFFICE...WE HAVE BEEN JUST
SEEING A FEW FLURRIES DUE TO CLOUD LAYER BEING RIGHT AT THE EDGE OF
THE MORE FAVORABLE ICE CRYSTAL REGION. EXPECT THIS
BORDERLINE/LIMITED CONDITION TO CONTINUE OVER THE SOUTH CENTRAL AND
SOUTHEASTERN CWA INTO THE EVENING HOURS AND WILL SHOW THE POTENTIAL
FOR FREEZING DRIZZLE IN THE FORECAST. WILL ISSUE AN SPS TO
HIGHLIGHT THE FREEZING DRIZZLE AND UNTREATED ROADS BECOMING
SLIPPERY FOR THE AREAS NOT CURRENTLY COVERED BY THE ADVISORY.
OTHERWISE...EXPECT THE FREEZING DRIZZLE TO DIMINISH FROM WEST TO
EAST THIS EVENING AS THE DEEPER MOISTURE FROM THE FEATURE OVER
WESTERN LAKE SUPERIOR MOVES OVER THE U.P. TONIGHT.
THE STRONG TROUGH IN THE SOUTHERN PLAINS WILL LIFT NORTHEAST
THROUGH THE LOWER GREAT LAKES REGION TONIGHT...STRENGTHENING A LOW
FROM 1007MB OVER SOUTHERN ILLINOIS TO 998MB BETWEEN LAKE
ERIE/ONTARIO AT 12Z SUNDAY. AS THAT OCCURS...THE MID LEVEL TROUGH
ASSOCIATED WITH THE SURFACE TROUGH OVER THE WESTERN LAKE WILL
DROP SOUTHEAST ACROSS UPPER MICHIGAN THROUGH SUNDAY MORNING. THE
SYNOPTIC LIQUID EQUIVALENT PRECIPITATION (TIED TO THE 850-650MB
FGEN) LOOKS TO BE IN THE 0.10-0.15 INCH RANGE FOR MOST OF THE CWA
THROUGH SUNDAY MORNING. SNOW RATIOS INITIALLY WILL LIKELY BE AROUND
10-15 TO 1 AS THERE IS STILL A PERIOD OF THE CLOUD BEING ABOVE/BELOW
THE DGZ. BUT THERE WILL LIKELY BE A TRANSITION TO A BRIEF (2-4HR)
PERIOD LATE TONIGHT INTO SUNDAY MORNING WHEN THE LOWEST 10-12KFT OF
THE ATMOSPHERE IS WITHIN THE DGZ. THIS WOULD LEAD TO A PERIOD OF
FLUFFIER SNOW AND RATIOS RISING TOWARDS OR EVEN ABOVE 20-1. DON/T
FEEL COMFORTABLE GOING MUCH ABOVE THAT DUE TO THE FORCING THAT IS
EXPECTED ABOVE THE DGZ. THUS...SYNOPTIC SNOW WOULD AMOUNT TO
1 TO 2.5-3.0 INCHES...WITH THE GREATEST OVER THE WEST HALF. BUT AS
IS NORMALLY THE CASE WITH LAKE SUPERIOR AND OUR TERRAIN
INFLUENCES...THAT ISN/T THE COMPLETE STORY ON THE SNOWFALL.
MUCH COLDER AIR WILL SURGE INTO THE AREA TONIGHT BEHIND THE
850-700MB TROUGH...WITH 850MB TEMPS FALLING FROM 19Z RAP ANALYZED
OF -5C TO -7C TO -19C EAST AND -24C WEST BY 18Z SUNDAY. THIS WILL
LEAD TO LAKE ENHANCEMENT DEVELOPING FROM WEST TO EAST TONIGHT AND
THEN TRANSITIONING TO PURE LAKE EFFECT AS THE DEEPER MOISTURE
DEPARTS ON SUNDAY. THE HELP FROM THE LAKE WILL BE FOCUSED IN THE
NORTHERLY WIND LOCATIONS OF THE WEST AND NORTH CENTRAL TONIGHT AND
THEN WINDS BACK TO THE NORTHWEST SUNDAY MORNING AND WEST-NORTHWEST
BY SUNDAY EVENING. WITH THAT COLD AIR SURGING IN...THE CLOUD LAYER
ON SUNDAY WILL TRANSITION TO BEING ABOVE THE DGZ. THUS...WOULD
EXPECT A TRANSITION OF THE SNOWFLAKES TO COLUMNS/PLATES AND LOWER
SNOW RATIOS BELOW 20-1. CONTINUED THE TREND TOWARDS THE HIGH
RESOLUTION MODELS FOR QPF AMOUNTS TONIGHT/SUNDAY IN THE
LAKE/TERRAIN ENHANCED AREAS (0.25-0.40 IN). THIS LEADS TO SNOWFALL
AMOUNTS OF 3-5 INCHES OF SNOW TONIGHT OVER THE FAVORED NORTH WIND
AREAS OVER THE WEST AND NORTH CENTRAL. THERE COULD BE SOME
LOCALIZED HIGHER AMOUNTS TOWARDS 5.5-6.0 INCHES. THE LOWERING RATIOS
ON SUNDAY WILL LEAD TO LOWER AMOUNTS OVER THE WEST...BUT COULD
STILL SEE 2-5 INCHES IN THE FAVORED NORTHWEST WINDS AREAS OVER THE
EAST. IN ADDITION TO THE SNOW...WINDS WILL QUICKLY INCREASE FROM
NORTHWEST TO SOUTHEAST TONIGHT...WITH GUSTS BETWEEN 30 TO 45 MPH
(HIGHEST NEAR LAKE SUPERIOR). THAT WILL LEAD TO BLOWING SNOW AND
COMBINED WITH THE EXPECTED SNOW...SHOULD SEE VISIBILITIES
FREQUENTLY REDUCED BELOW ONE MILE OVER THE NORTHERN HALF OF THE
CWA. THUS...THINK THE GOING ADVISORY LOOKS GOOD WITH THE FORECASTED
SNOWFALL AMOUNTS AND IMPACT WITH THE REDUCED VISIBILITIES FROM
BLOWING SNOW. AS MENTIONED ABOVE...THINK SOME HIGHER TERRAIN
LOCATIONS FLIRTING WITH 12HR WARNING SNOWFALL AMOUNTS (DUE TO THE
OVERALL AVERAGE SNOW RATIO BEING JUST BELOW OUR LAKE EFFECT WARNING
CRITERIA). BUT WITH MUCH OF THE SNOW FALLING ON A WEEKEND
OVERNIGHT AND THE EXPECTED COVERAGE FAIRLY LOCALIZED...WILL KEEP
THE ADVISORY IN PLACE.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 541 AM EST SAT JAN 3 2015
NAM SHOWS THE UPPER PATTERN CONSISTS OF A 500 MB TROUGH OVER THE
CENTRAL U.S. 12Z SUN WITH SEVERAL SHORTWAVES EMBEDDED IN THIS
TROUGH. THE TROUGH DIGS INTO THE UPPER GREAT LAKES ON SUNDAY AND
REMAINS OVER THE AREA INTO TUE. COLD AIR MOVES INTO THE AREA ON
SUNDAY AND REMAINS THROUGH MON NIGHT IN THIS FORECAST PERIOD.
ACTIVE FORECAST PERIOD WITH WIND CHILL PROBLEMS...BLOWING SNOW AND
LOW VISIBILITIES...HIGH WAVES AND COLD TEMPERATURES. WITH THE HIGHER
WINDS AND BLOWING SNOW...DECIDED TO CONTINUE THE ADVISORIES INTO
SUNDAY FOR THIS EVEN THOUGH THE HEAVIEST SNOW IS DONE. TEMPERATURES
WILL CONTINUE TO FALL ALL DAY SUNDAY AND USED A NON DIURNAL CURVE
WITH FALLING TEMPERATURES ALL DAY. IT DOES GET COLD ENOUGH AND HIGH
ENOUGH WIND SPEEDS FOR SUNDAY NIGHT INTO MONDAY MORNING TO WORRY
ABOUT WIND CHILLS AND AT SOME POINT WILL HAVE TO THINK ABOUT GOING
WITH A WIND CHILL WATCH...BUT DO NOT WANT TO HAVE WINTER WEATHER
ADVISORIES OUT AND THEN A WIND CHILL WATCH WHICH WOULD BE IN THE
FOURTH FORECAST PERIOD FOR NOW. WILL MENTION LOW WIND CHILLS IN THE
HWO PRODUCT AND NOT HAVE DOUBLE HEADLINES RIGHT NOW. WITH HIGHER
WINDS ON THE WATER...LAKESHORE FLOODING BECOMES A PROBLEM AND WILL
HAVE TO GO WITH A LAKESHORE FLOOD ADVISORY FOR PARTS OF THE AREA
ALONG LAKE SUPERIOR FROM LATE TONIGHT INTO SUNDAY NIGHT. OTHER THAN
THE HEADLINES OR POTENTIAL HEADLINES...DID NOT MAKE TOO MANY DRASTIC
CHANGES TO THE GOING FORECAST FOR TEMPERATURES...POPS OR WEATHER.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB TROUGH OVER THE
U.S. WITH VERY COLD AIR ENTRENCHED OVER MOST OF THE COUNTRY 12Z TUE.
AN ALBERTA CLIPPER SYSTEM MOVES TO THE SOUTH OF THE AREA ON TUE AND
BRINGS A REINFORCING AND COLDER SHOT OF AIR INTO THE UPPER GREAT
LAKES 12Z WED WITH 850 MB TEMPERATURES DROPPING FROM -19C OVER LAKE
SUPERIOR ON TUE TO -30C 12Z WED AS STRONG HIGH PRESSURE BUILDS INTO
THE PLAINS. THE CORE OF THE COLD AIR MOVES EAST INTO NEW ENGLAND 12Z
THU WITH ANOTHER SHOT OF COLD AIR COMING IN FOR FRI WITH ANOTHER
CLIPPER SYSTEM MOVING THROUGH THU NIGHT. TEMPERATURES WILL CONTINUE
TO BE WELL BELOW NORMAL THIS FORECAST PERIOD WITH LAKE EFFECT SNOW
CONTINUING. WENT WITH HIGHER POPS IN THE EXTENDED FOR LAKE EFFECT
SNOWBELTS AFFECTED BY NORTHWEST WINDS.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1250 PM EST SAT JAN 3 2015
UPPER MICHIGAN IS BETWEEN FEATURES AT THIS TIME...WITH VFR
CONDITIONS AT KIWD/KCMX AND IFR CEILINGS AND SOME FOG/SNOW/DRIZZLE
AT KSAW. THESE CONDITIONS WILL STAY FAIRLY STEADY STATE OVER THE
NEXT COUPLE-FEW HOURS...THEN WILL SEE CONDITIONS DETERIORATING FROM
WEST TO EAST THIS EVENING AS THE AREA OF SNOW IN THE MINNESOTA
ARROWHEAD MOVES INTO THE AREA. WITH ALL THREE TAF SITES HELPED BY
UPSLOPE WINDS AND LAKE ENHANCEMENT...BROUGHT THEIR VISIBILITIES
BELOW ALT LANDING MINS DURING THE OVERNIGHT HOURS WHEN THE
STRONGEST SNOW WILL BE MOVING THROUGH. GUSTY WINDS WILL ALSO CREATE
BLOWING SNOW OVERNIGHT INTO SUNDAY...WHICH COULD LEAD TO A
TRANSITION TO VERTICAL VISIBILITIES UNDER 500FT AT TIMES. THE
WIDESPREAD SNOW WILL DEPART LATE TONIGHT INTO EARLY SUNDAY
MORNING...LEAVING LAKE ENHANCED/EFFECT SNOW AT ALL THREE SITES
SUNDAY MORNING UNDER NORTHWEST WINDS. KEPT VISIBILITIES DOWN DURING
THAT PERIOD DUE TO THE SMALLER SNOW FLAKES BEING EFFICIENT REDUCERS
OF VISIBILITY.
&&
.MARINE...(FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE)
ISSUED AT 335 PM EST SAT JAN 3 2015
THE BUSY MARINE WEATHER WE HAVE HAD RECENTLY WILL CONTINUE WITH
GALES AND HEAVY FREEZING SPRAY RETURNING AND HOISTED GALE WARNINGS
AND HEAVY FREEZING SPRAY WARNINGS FOR LATE TONIGHT INTO SUNDAY. A
COUPLE MORE GALE EVENTS ARE POSSIBLE ON LAKE SUPERIOR TUESDAY NIGHT
AND WEDNESDAY MORNING AND AGAIN FOR THURSDAY NIGHT WITH NORTHWEST
GALES EXPECTED THEN. FREEZING SPRAY WILL ALSO BE A PROBLEM THROUGH
MOST OF THIS FORECAST PERIOD.
WINDS SHIFT TO THE NORTH LATE TONIGHT AS THE NORTHERN PLAINS
TROUGH MERGES WITH ANOTHER LOW PRESSURE SYSTEM LIFTING NORTH OVER
THE CENTRAL GREAT LAKES. NORTH GALES TO 35-40 KTS ARE EXPECTED
SUNDAY ESPECIALLY OVER THE EASTERN HALF OF LK SUPERIOR. HEAVY
FREEZING SPRAY WILL DEVELOP TONIGHT AS ARCTIC AIR POURS OVER
LK SUPERIOR. GALES SHOULD DIMINISH BY LATE SUNDAY NIGHT...BUT NW-W
WINDS TO 30 KTS AND HEAVY FREEZING SPRAY WILL LINGER THROUGH MONDAY.
W-SW WINDS TO 25 KTS ON TUESDAY AS A CLIPPER SYSTEM CROSSES UPPER
GREAT LAKES. BEHIND THE CLIPPER...PLAN ON ANOTHER ROUND OF NW GALES
AND HEAVY FREEZING SPRAY THROUGH WEDNESDAY.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 7 PM EST /6 PM CST/ THIS EVENING TO
7 PM EST /6 PM CST/ SUNDAY FOR MIZ001>003-009-084.
WINTER WEATHER ADVISORY FROM 4 AM TO 7 PM EST SUNDAY FOR MIZ006-
007-085.
LAKESHORE FLOOD ADVISORY FROM 1 AM TO 1 PM EST SUNDAY FOR
MIZ001>003.
LAKESHORE FLOOD ADVISORY FROM 7 AM TO 7 PM EST SUNDAY FOR
MIZ005>007.
WINTER WEATHER ADVISORY FROM 1 AM TO 7 PM EST SUNDAY FOR MIZ004-
005.
LAKE SUPERIOR...
HEAVY FREEZING SPRAY WARNING FROM 7 PM SUNDAY TO 7 PM EST
TUESDAY FOR LSZ251-267.
GALE WARNING FROM 4 AM SUNDAY TO 7 AM EST MONDAY FOR LSZ249>251-
267.
HEAVY FREEZING SPRAY WARNING FROM 1 AM SUNDAY TO 7 PM EST
TUESDAY FOR LSZ249-250-266.
GALE WARNING FROM 1 AM SUNDAY TO 7 AM EST MONDAY FOR LSZ266.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 1 AM EST /MIDNIGHT CST/ TUESDAY FOR LSZ240>248-
263>265.
GALE WARNING FROM 9 PM THIS EVENING TO 7 AM EST MONDAY FOR
LSZ242>245-248-263>265.
HEAVY FREEZING SPRAY WARNING FROM 10 PM EST /9 PM CST/ THIS
EVENING TO 1 PM EST /NOON CST/ MONDAY FOR LSZ162.
LAKE MICHIGAN...
GALE WARNING FROM 7 AM TO 7 PM EST SUNDAY FOR LMZ221-248-250.
&&
$$
SHORT TERM...SRF
LONG TERM...07
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS JACKSON MS
1104 AM CST SAT JAN 3 2015
.UPDATE...
THE PRIMARY ADJUSTMENT TO THE FORECAST THIS MORNING INCLUDES SHIFTING
THE SEVERE WEATHER RISK MORE INTO CENTRAL/ERN MS WHERE THE ELEVATED
THREAT FOR TORNADOES/DAMAGING WINDS/HAIL CONTINUES. THE FORECAST IS
GENERALLY ON TRACK WITH A RISK FOR FLASH FLOODING CONTINUING OVER
MOST OF THE AREA...AND ALL ELSE IS GENERALLY ON TRACK.
A STRONG SHORTWAVE TROUGH OVER THE SOUTHERN PLAINS WILL LIFT
NORTHEAST TODAY WITH MODEST HEIGHT FALLS APPROACH THE AREA THIS
AFTERNOON. THE INCREASED FORCING WILL HELP TO REINVIGORATE CONVECTIVE
COMPLEX CURRENTLY MOVING TOWARD THE NATCHEZ TRACE CORRIDOR AND
GUIDANCE BRINGS INTO ERN MS BY LATE THIS AFTN. THE BIG CONCERN
IS GREATER DESTABILIZATION TAKING PLACE OVER SE LA/SRN MS WITH
EFFECTIVE LOW LEVEL SHEAR/SRH (200+ M2/S2) AND SFC-BASED INSTABILITY
ON THE INCREASE THERE...WE CONTINUE TO BE CONFIDENT IN THE SEVERE
WEATHER POTENTIAL AND ELEVATED THREAT AREA GENERALLY ALONG AND SE OF
THE NATCHEZ TRACE CORRIDOR AS INTENSIFYING CONVECTION INTERACTS WITH
THE IMPROVING ENVIRONMENT WITH LATEST HRRR GUIDANCE SHOWING MID/
UPPER 60S DEWPOINTS UP TO THE GOLDEN TRIANGLE AREA BY EARLY/MID AFTN.
THE LATEST NEAR TERM GUIDANCE INDICATES THAT BROKEN LINEAR CONVECTIVE
SYSTEM MAY SOLIDIFY IN VICINITY OF CURRENT COLD POOL OVER WRN/CENTRL MS
AND GRADUALLY MOVE INTO ERN MS BY EARLY EVNG. AS THE SYSTEM SLOWS
DOWN...EXPECT POTENTIAL FOR INCREASING FLASH FLOOD THREAT WITH
INTENSE RAINFALL RATES PRODUCING LOCALIZED AREAS OF 3 TO 5 INCHES OVER
WET GROUND. /EC/
&&
.AVIATION...A MIX OF CLOUDS AND CONVECTION WILL RESULT IN MAINLY
MVFR/IFR FLIGHT CATEGORIES AT TAF SITES ACROSS THE AREA TODAY INTO
TONIGHT. SOME STORMS COULD BE SEVERE THIS AFTERNOON INTO THIS
EVENING...ESPECIALLY ACROSS CENTRAL...SOUTH...AND EAST MISSISSIPPI
(KHKS...KJAN...KGTR...KMEI...& KHBG)...AND CAPABLE OF PRODUCING
DAMAGING WINDS...LARGE HAIL...AND SOME TORNADOES. WHILE SOME LIGHT
RAIN WILL LINGER ACROSS THE AREA OVERNIGHT INTO EARLY SUNDAY
MORNING...ESPECIALLY IN THE EAST...THE HEAVIEST CONVECTION SHOULD BE
EXITING EAST AND SOUTHEAST MISSISSIPPI BETWEEN 01-03Z THIS EVENING.
WINDS TODAY WILL BE GUSTY FROM THE SOUTH...BUT WILL GRADUALLY BECOME
MORE WESTERLY AND EVENTUALLY NORTHWESTERLY IN THE WAKE OF THE COLD
FRONTAL PASSAGE THIS EVENING AND OVERNIGHT. /19/
&&
.PREV DISCUSSION... /ISSUED 400 AM CST SAT JAN 3 2015/
INCREASING RISK FOR SIGNIFICANT ARCTIC OUTBREAK NEXT WEEK...
SHORT TERM...THIS SYSTEM SHOULD MOVE EAST OF AREA BY EARLY MORNING
SUNDAY...AND IN THE WAKE OF IT COLD AIR ADVECTION SHOULD RESULT IN
WIDESPREAD LOW CLOUDS AND SOME PATCHY LIGHT RAIN AND DRIZZLE INTO AT
LEAST EARLY SUNDAY. TEMPS SHOULD BE SOME 20 DEG COOLER SUNDAY THAN
SATURDAY. WITH THE SHORTWAVE PASSING THROUGH THE REGION REGIONAL
CROSS SECTIONS HOLDS ON TO SOME LOW CLOUDS FOR SUNDAY NIGHT. SO HAVE
GENERALLY PARTLY CLOUDY SKIES FOR THAT PERIOD...WHICH WILL HINDER
RADIATIONAL COOLING. SO WENT CLOSER TO A MILDER SOLUTION FOR SUNDAY
NIGHT./17/
LONG TERM...MONDAY THROUGH FRIDAY...THE MAIN FOCUS OF THE LONG TERM
CONTINUES TO BE THE MUCH COLDER AIR THAT IS FORECAST TO AFFECT THE
ARKLAMISS REGION DURING THE MIDDLE OF NEXT WEEK. THE FIRST SHOT OF
ARCTIC AIR WILL ARRIVE BEHIND THIS WEEKENDS STORM SYSTEM. A 1040MB
SURFACE HIGH WILL FILTER INTO THE REGION BEHIND THE FRONT BUT WILL
ONLY GIVE A SHORT...GLANCING BLOW AS THIS SFC HIGH WILL BE
PROGRESSIVE AND MOVE ACROSS THE OHIO VALLEY BY TUESDAY. THIS SHOT OF
COLDER AIR WILL BRING SUBFREEZING LOWS ON MONDAY AND TUESDAY AND
COOLER DAYTIME HIGHS FOR MONDAY. THERE WILL BE A SHORT MODERATION IN
TEMPERATURES ON TUESDAY BEFORE A DRY COLD FRONT MOVES THROUGH THE
REGION. THE AIR BEHIND THIS WILL BE THE COLDEST WE HAVE SEEN YET.
MODELS CONTINUE TO AGREE IN A 1050+ MB SURFACE HIGH DIVING SOUTH
INTO THE CENTRAL PLAINS. THIS WILL SPREAD A COLD AIRMASS DEEP INTO
THE SOUTH WITH SOME POTENTIAL FOR A HARD FREEZE...PARTICULARLY FOR
THE HIGHWAY 82 CORRIDOR. THIS WOULD BRING OVERNIGHT LOWS ON
WEDNESDAY NIGHT INTO THE TEENS AND DAYTIME HIGHS ON THURSDAY NOT
REACHING ABOVE FREEZING. THE REMAINDER OF THE AREA SHOULD SEE LOWS
WEDNESDAY NIGHT IN THE TEENS AND 20S BUT SHOULD GET ENOUGH WARMTH ON
THURSDAY TO REACH INTO THE UPPER 30S/AROUND 40. GIVEN THE TIGHTENED
PRESSURE GRADIENT OVER THE REGION LATER WEDNESDAY INTO EARLY
THURSDAY...THIS WILL CREATE WIND CHILL READINGS INTO THE SINGLE
DIGITS AND LOWER TEENS. OVERALL THIS PATTERN WILL LEAD TO AN
EXTREMELY COLD AND RAW PERIOD AS THE SFC HIGH STICKS AROUND OVER THE
REGION THROUGH THE END OF THE WEEK. /28/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLASH FLOOD WATCH THROUGH THIS EVENING FOR MSZ030-031-033-038-
039-045-046-051-052-056>058-064>066-072>074.
FLASH FLOOD WATCH UNTIL 6 PM CST THIS EVENING FOR MSZ018-019-
025>029-032-034>037-040>044-047>050-053>055-059>063.
LA...FLASH FLOOD WATCH UNTIL 6 PM CST THIS EVENING FOR LAZ007>009-015-
016-023>026.
AR...FLASH FLOOD WATCH UNTIL 6 PM CST THIS EVENING FOR ARZ074-075.
&&
$$
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
427 PM CST Sat Jan 3 2015
.SHORT TERM...(This Evening through Sunday Night)
Issued at 426 PM CST SAT JAN 3 2015
Tonight:
The second phase of the approaching winter system will quickly make
its presence felt over our CWA. The latest satellite and radar data
reveal the rapid development of the deformation zone precipitation
shield across south central and central KS. Satellite trends appear
to support the latest operational NAM, GFS and ECMWF which depict a
more southern track (vs yesterday`s solutions) of the main
precipitation. The HRRR and RUC also confirm this. So, with only
minor adjustments needed have shifted the axis of heavier snowfall
a bit further south.
Model output via Bufkit and the operational model snow algorithms
all point to a general 1-2 inch swath with isolated amounts to 3
inches possible from east central KS through west central MO. Snow
amounts will be limited by 1) initially falling as rain and 2)
melting at onset due to above freezing temperatures. An expected
quick transition to snow due to strong dynamic forcing within the
deformation cloud shield and the eventual surge of strong cold air
advection should mitigate this melting. Also of note is the
convective looking nature of the growing deformation cloud shield.
Close inspection of Bufkit data and model soundings suggest CSI may
be possible for a brief period early this evening with elevated CAPE
values approaching 100 J/kg. Evening shift will need to keep an eye
on this for possible thunder-snow and rapid increase in snow rates.
Strong cold air advection will rush from the Central Plains this
evening. Upstream obs show single digit temperatures and wind gust
of 35-40 mph. Thus blowing snow tied to the baroclinc zone snow
which will form across southeast NE this evening will be added to
the northern and western CWA. Have also allowed light snow/flurries
to linger well after midnight as ice crystals will be produced down
into the boundary layer as temperatures fall to -15C within the
saturated cloud layer between 2500-5000ft agl.
Due to the combo of 25-35 mph winds and single digit temperatures
have added a wind chill advisory for the northwest tip of MO.
Sunday and Sunday Night:
Brutally cold. That`s all you need to know. A 1041 mb surface high
will sit over KS and western MO during this period. A stiff
northwest wind will diminish from west to east in the morning and
clouds will clear so we`ll get some relief from the cold. However,
the weight of h8 temperatures of -10C to -15C will limit highs to
mainly the teens.
Some mid level warm advection clouds streaming in from NE may be the
saving grace for below zero temperatures Monday night. That plus
very light winds may only generate wind chills from -5 to -15F.
.LONG TERM...(Monday through Saturday)
Issued at 426 PM CST SAT JAN 3 2015
Looking ahead to the extended...everyone may want to keep those
heavy winter coats out a while longer. The forecast continues to
remain cold and mostly dry until late in the upcoming work week. An
upper level ridge will remain planted across the western US coast
with a very wide longwave trough over the remainder of the US. This
places the CWA in northwest flow aloft with a number of disturbances
translating through the main flow. Each of these systems will
provide a reinforcing shot of cold air into the region. With snow
remaining on the ground, airmass modification will be minimal
allowing morning lows to tumble into the low single digits with a
few negative single digits along the MO/IA border Monday morning.
While the EC and GFS 850mb temperatures are off a few degrees from
each other, they are still bringing in temperatures ranging from -17 to
-25 C over the CWA. Thus, it is likely that lows will plummet into
the negative singles Wed morning across the northern half of CWA,
and then low singles on either side of zero by Thurs morning. High
temperatures look to warm into the upper teens and into the low and
mid 20s much of the week, except Wed when it will be tough to climb
into the teens. Precip-wise, the northeast corner of the CWA may see
some light snow Mon night as one of the previously mentioned systems
glances the area. Long-range models are also indicating that the
region may see increasing chances for precip late in the week, but
given that it is towards the end of the extended a lot can, and
probably will, change over the next several days as the system
begins to evolve.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1230 PM CST SAT JAN 3 2015
Passing of upper shortwave has stripped away deeper moisture and
IFR/MVFR cigs from eastern KS and northwest MO. However, the MVFR
cigs remain extremely close to the terminals and should lie along and
south of an KIXD to Kirksville line this afternoon. Short range
models like the RUC and 12z NAM seem to have a decent handle on this.
Will allow MVFR cigs to move back into the Kansas City terminals late
this afternoon as next wave of precipitation spreads quickly
northeast from KS. Will likely see an hour or two of rain before
rapid transition to snow. As winds shift and increase from the northwest
this evening they will become quite gusty with blowing snow likely
persisting past midnight.
Should see VFR conditions return by mid Sunday morning as clouds scatter
out.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY until 3 AM CST Sunday FOR KSZ025-057-
103>105.
WINTER WEATHER ADVISORY until 6 AM CST Sunday FOR KSZ102.
MO...WINTER WEATHER ADVISORY until 3 AM CST Sunday FOR MOZ013>017-
020>025-028>033-037>039-043-044.
WINTER WEATHER ADVISORY until 6 AM CST Sunday FOR MOZ001>008-011-
012.
WIND CHILL ADVISORY from 3 AM to 9 AM CST Sunday FOR MOZ001-002-
011.
&&
$$
SHORT TERM...MJ
LONG TERM...PMM
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS KANSAS CITY/PLEASANT HILL MO
1238 PM CST Sat Jan 3 2015
.UPDATE...
Issued at 1230 PM CST SAT JAN 3 2015
Have lowered afternoon PoPs and raised temperatures for this
afternoon. Shortwave trough has moved quickly through MO and
stripped away deeper moisture and heavier rainfall, leaving behind
shallow saturated boundary layer and areas of drizzle generally south
of a Kansas City to Kirksville. Significant dry slot noted in water
vapor imagery moving through eastern KS/western MO has resulted in
some breaks in the overcast and warmer temperatures. So, have raised
highs accordingly.
Still looking like deformation precipitation shield will lift rapidly
northeast this afternoon and evening. Raising temperatures this
afternoon may lead to an extra hour or two of rain or rain/snow mix
before total transition. If transition takes longer it likely would
affect snow amounts negatively. HRRR and 12z NAM/GFS continue on a
path of a more southern track of the deformation precipitation band
and may need to shift heavier snow band (used in a relative sense as
snow amounts still look like 1-2" with isolated 3").
&&
.SHORT TERM...(Today through Monday)
Issued at 358 AM CST SAT JAN 3 2015
Main focus in the short term will be wintry precipitation chances
today and tonight as a low pressure system pushes northeast across
the region. In the near term, mainly liquid precipitation out ahead
of the surface low will lift NE across the southeastern two-thirds
of the CWA. Surface temperatures in areas where precipitation is
expected this morning are mainly at 32 degrees or higher, and
dewpoint temperatures are also hovering right at the freezing mark,
preventing any wet-bulb effects from lowering surface temperatures.
Have still included a chance of freezing drizzle in case some very
light precipitation on the northern edge falls over sub-freezing
temperatures, but do not expect more than a light glaze of ice.
Morning precipitation will begin to clear off to the northeast as
the dry slot moves in between 10 AM and noon, leaving patchy drizzle
and stratus across the region. A second round of precipitation
associated with a rather pronounced PV anomaly is still expected to
lift from the TX panhandle into our far western CWA by late
afternoon to early evening, and will spread northeast through the
night. Precipitation type will likely begin as rain, but will mix
with and then transition to snow as colder air wraps in on the back
side of the surface low after 21z. 00z NAM/GFS continued a farther
south trend in highest precipitation totals, but 00z EC and 06z NAM
have pulled precipitation back a touch north, so have not jumped to
significantly change the location of highest precipitation totals
for this evening and tonight.
Precipitation totals of 0.15" to at most 0.2" are still anticipated
with the second area of wintry precip tonight, despite the strength
of the system and availability of moisture. The window for precip in
any one area will be fairly brief due to the speed of the system and
the arrival of dry air undercutting the deep moisture, resulting in
a quick 1-2" of total snow within a few hour period. A brief period
of blowing snow will also be a concern across far northeast KS and
northwest and northern MO after 03z as gusty northwest winds sweep
into the region, so have added the remainder of our northern counties
into the winter weather advisory for 1-2" snow and blowing snow.
Snowfall should taper quickly between 09z-12z Sunday morning as
frigid, dry air surges into the region from the northwest. Wind
chill values on Sunday morning are still expected to fall into the
-5 to -15 degree range, and may fall as low as -20 in far northwest
MO before 15z. May need a small wind chill advisory for areas that
will fall below -15 F Sunday morning, but will wait to issue until
at least the morning precipitation clears out of the region and
colder air starts to advance into the Plains.
Very cold and mainly quiet conditions are expected Sunday night
through Monday night. A brief brush of light snow is possible across
northeast MO late Monday afternoon through Monday night, but most
accumulating snow will likely stay north of the CWA.
.LONG TERM...(Tuesday through Friday)
Issued at 358 AM CST SAT JAN 3 2015
The extended forecast looks to be dry and rather cold, as Canadian
air intrudes into the area. Mid range and extended models develop a
N-S oriented elongated surface ridge, which will bring a steady diet
of cold air to the Central Plains and the Lower Missouri River
Valley. There is some discrepancy between the ECMWF and the GFS
regarding just how cold the air mass will be. The EC indicates 850
mb temps down in the -15C to -20C range, while the GFS only drops
into the -10C to -12C range. At any rate, it looks rather chilly
through the middle to late week, with highs in the teens and 20s,
and lows dropping to the single digits. These temperatures could
drop even more with ample snow fall north of the forecast area,
which would mitigate the modification of the cold air. The next good
chance for precip looks to be late next week, but models differ
quite a bit with that solution at this point, so will keep specifics
out for now.
&&
.AVIATION...(For the 18Z TAFS through 18Z Sunday Afternoon)
Issued at 1230 PM CST SAT JAN 3 2015
Passing of upper shortwave has stripped away deeper moisture and
IFR/MVFR cigs from eastern KS and northwest MO. However, the MVFR
cigs remain extremely close to the terminals and should lie along and
south of an KIXD to Kirksville line this afternoon. Short range
models like the RUC and 12z NAM seem to have a decent handle on this.
Will allow MVFR cigs to move back into the Kansas City terminals late
this afternoon as next wave of precipitation spreads quickly
northeast from KS. Will likely see an hour or two of rain before
rapid transition to snow. As winds shift and increase from the northwest
this evening they will become quite gusty with blowing snow likely
persisting past midnight.
Should see VFR conditions return by mid Sunday morning as clouds scatter
out.
&&
.EAX WATCHES/WARNINGS/ADVISORIES...
KS...WINTER WEATHER ADVISORY until Midnight CST tonight FOR KSZ025-
057-103>105.
WINTER WEATHER ADVISORY from 6 PM this evening to 6 AM CST
Sunday FOR KSZ102.
MO...WINTER WEATHER ADVISORY until Midnight CST tonight FOR
MOZ013>017-020>025-028>033-037>039-043-044.
WINTER WEATHER ADVISORY from 6 PM this evening to 6 AM CST
Sunday FOR MOZ001>008-011-012.
&&
$$
UPDATE...MJ
SHORT TERM...Laflin
LONG TERM...Leighton
AVIATION...MJ
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
125 PM EST SAT JAN 3 2015
.SYNOPSIS...
A STORM SYSTEM IS EXPECTED TO BRING A MIX OF SNOW, SLEET AND
FREEZING RAIN ACROSS NORTHEAST PENNSYLVANIA AND CENTRAL NEW YORK
ON TODAY. THE WINTRY MIX WILL THEN CHANGE TO RAIN TONIGHT...FOLLOWED BY
WARMER TEMPERATURES AND SHOWERS ON SUNDAY. A SHARP COOL DOWN WILL
FOLLOW FOR SUNDAY NIGHT INTO EARLY NEXT WEEK ACCOMPANIED BY STRONG
WINDS AND LAKE EFFECT SNOW.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
1050 AM UPDATE...
PCPN ON TRACK TO MV INTO CWA FM CNTRL PA AS WMFNT IS DVLPNG ACRS
THE MIDWEST INTO NWPA AT THIS TIME. STRONG ISENTROPIC UPGLIDE
ALLOWING PCPN TO BREAK OUT BACK TO THE SOUTHWEST. AS WARM
ADVECTION STRENGTHENS OVR THE NEXT SVRL HRS ON DVLPNG LOW-LVL JET
EXPECT PCPN TO ENCOMPASS ENTIRE CWA BY 20Z THIS AFTN. HV DELAYED
ONSET BY AN HR OR TWO AS RADAR IS PICKING UP ON MID-DECK WITH JUST
VRY LGT SNOW NOW FALLING OVR SRN LUZERNE CNTY.
RADAR POP-UP SKEW-T INDICATING ENTIRE COLUMN BLO FRZG CWA-WIDE
WITH 800MB TEMPS WARMING TWD 0C AS OF 1530Z. THIS SEEMS TO
CORRELATE WITH LATEST HIRES MODELS, INCLUDING HRRR AND RAP. STILL
EXPECTING SVRL HRS OF SNOW AT THE ONSET. AS TEMPS ALOFT WARM,
EXPECT A MIX OF SLEET AND FZRA TO WORK IN AS FAR EAST AS A
ONONDAGA-PIKE CNTY LINE BY 21Z. CLDR TEMPS WL BE ABLE TO HOLD IN
ACRS THE EAST THE LONGEST WITH SNOW POSSIBLE UNTIL CLOSE TO 00Z.
QUESTION CONTINUES TO CNTR ON HOW MUCH FZRA CAN BE EXPECTED AS CLD
LYR LKLY TO BE ALMOST 4KFT DEEP WITH MAX WARM LYR TEMPS ARND
800MB OF +3C TO +4C. AS COLD LYR DIMINISHES IN DEPTH AND TEMPS
WARM ALOFT TO +6C BTWN 21Z AND 00Z EXPECT THIS TO BE MOST LKLY
TIME FOR FZRA ACRS THE CWA. HWVR, THIS LEADS TO THE QUESTION OF
HOW MUCH ICE WL ACTUALLY BE ABLE TO ACCRETE AS WARM AIR IS DRAGGED
DOWN FM ALOFT. HV MASSAGED HRLY T/TD VALUES AND DELAYED ONSET OF
PCPN BY AN HR OR TWO TO GET A BETTER HANDLE ON CURRENT CONDITIONS
BUT NO MAJOR CHGS NEEDED AT THIS TIME.
PREV DISCUSSION BLO...
MAIN FOCUS FOR THE NEAR TERM CONTINUES TO BE WINTRY MIX DUE TO
ARRIVE BY LATER TODAY AS A STRENGTHENING LOW RIDES UP TO OUR WEST.
EXPECT SNOW TO BREAK OUT FROM SW TO NE BEGINNING NEAR MIDDAY WITH
MOST AREAS SEEING A FEW HOURS WORTH OF SNOWFALL BEFORE THE
TRANSITION IN P-TYPES BEGINS TOWARD THE MID TO LATE AFTERNOON.
GENERALLY LOOKING AT 1 TO 2 INCHES OF SLUSHY SNOW ACCUMULATION BEFORE
THIS OCCURS. AS THE WARMER AIR BEGINS TO MOVE IN ALOFT ASSOCIATED
WITH STRONG LLJ EXPECT TRANSIT ON TO SLEET/FREEZING RAIN TO OCCUR.
PROFILES CONTINUE TO INDICATE A RELATIVELY DEEP COLD LAYER IN THE
LOW LEVELS WHICH INDICATES MORE SLEET THAN FREEZING RAIN WILL OCCUR
DURING THE TRANSITION BEFORE THE CHANGE TO ALL RAIN OCCURS
TONIGHT. HOWEVER GIVEN THAT MOST OF THE AREA LOOKS TO SEE AT THE
LEAST A VERY BRIEF PERIOD OF FREEZING RAIN ALONG WITH THE SNOW AND
SLEET WE DO EXPECT SOME SLIPPERY CONDITIONS SO MAINTAIN THE WINTER
WEATHER ADVISORIES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE TRANSITION FROM SNOW TO A WINTRY MIX TO RAIN WILL BE ONGOING EARLY
IN THE PERIOD. WESTERN PORTIONS OF THE CWA WILL HAVE CHANGED
MAINLY TO RAIN BY EARLY EVENING WITH THE TRANSITION ZONE AT THIS
TIME RIGHT NEAR THE I-81 CORRIDOR WHERE THE WINTRY MIX WILL BE
OCCURRING WITH TEMPS NEAR NEAR FREEZING. AS THE EVENING PROGRESSES
THIS TRANSITION ZONE WILL SHIFT EAST WITH THE EASTERN AREAS
LINGERING WITH SLEET AND FREEZING RAIN UNTIL ABOUT MIDNIGHT AS
COLD AIR STRUGGLES TO GET OUT OF THE MOUNTAINS AND MOHAWK VALLEY.
AS MENTIONED, MODELS CONTINUE BE IN PRETTY GOOD OVERALL AGREEMENT
BUT AS IS TYPICAL, THE NAM IS COLDEST IN THE LOW LEVELS AND WE
LEANED TONIGHT`S TEMPS IN THE EAST TOWARD NAM SOLUTION AS IT TENDS
TO DUE QUITE WELL WITH THESE TYPE OF COLD AIR DAMMING SCENARIOS.
FOLLOWING THE CHANGE OVER FROM WINTRY PRECIP, RAIN CONTINUES
OVERNIGHT INTO SUNDAY MORNING WITH TEMPS CONTINUING TO RISE. WHILE
THIS IS NOT EXPECTED TO BE ANY TYPE OF MAJOR HYDRO EVENT, IT IS
WORTH MENTIONING THAT TOTAL QPF AMOUNTS OF 1 TO 1.5 INCHES ARE
FORECAST BY THE TIME THE RAIN WINDS DOWN TO A FEW SHOWERS BY
AROUND MIDDAY SUNDAY. WE DON`T EXPECT FLOODING BUT THIS WILL BE
ENOUGH TO CAUSE RISES ON RIVERS.
CONDITIONS WILL BE VERY MILD WITH JUST A FEW SHOWERS BY SUNDAY
AFTERNOON. HIGHS WILL RANGE FROM THE MID 40S TO LOW 50S. THE
WARMTH WILL BE SHORT LIVED AS A STRONG COLD FRONT COMES THROUGH
SUNDAY EVENING WITH SHOWERS TRANSITIONING TO SNOW SHOWERS AND
POTENTIALLY SIGNIFICANT LAKE EFFECT SNOW BEGINNING TO SET UP SE OF
LAKE ONTARIO. THE COLD AIR AND SNOW SHOWERS / LAKE EFFECT WILL
ALSO BE ACCOMPANIED BY STRONG WINDS LIKELY GUSTING AT LEAST 30 TO
40 MPH.
&&
.LONG TERM /WEDNESDAY THROUGH FRIDAY/...
1 PM UPDATE...
BITTERLY COLD AIR AND LAKE EFFECT SNOW WILL DOMINATE THE LONG
TERM PERIOD.
BEHIND A DEPARTING CLIPPER TUESDAY NIGHT INTO EARLY WEDNESDAY, THE
FIRST CHUNK OF COLDER AIR WILL MOVE ACROSS OUR AREA. LAKE EFFECT
SNOW WILL DEVELOP SOUTHEAST OF THE LAKES ON A WEST TO WEST-
NORTHWEST WIND. A SECOND AND MUCH MORE IMPRESSIVE SURGE OF ARCTIC
AIR WILL MOVE IN WEDNESDAY NIGHT INTO THURSDAY. 850 TEMPS FALL
INTO THE MID 20S BELOW ZERO BY 12Z THURSDAY. LOWS BELOW ZERO ARE
LIKELY BOTH THURSDAY AND FRIDAY MORNING. HIGHS THURSDAY MAY NOT
GET OUT OF THE SINGLE DIGITS IN SOME AREAS. WITH A NORTHWEST WIND
THROUGH THE PERIOD, PERIODS OF LAKE EFFECT SNOW WILL BE LIKELY.
THIS MAY BE A BIT TEMPERED BY THE LOW INVERSION HEIGHTS (SHALLOW
ARCTIC AIR).
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
WIDESPREAD IFR VSBYS THIS AFTERNOON/EVENING IN WINTRY MIX CHANGING
TO RAIN. WIDESPREAD IFR CIGS WITH ALT MINS LIKELY AND AIRPORT MINS
POSSIBLE AT KBGM.
WIDESPREAD PRECIPITATION WILL CONTINUE ACROSS THE TERMINALS
THROUGH EARLY EVENING. AFTER A 1 TO 3 HOUR PERIOD OF SNOW/SLEET
WITH IFR VSBYS, WE WILL SEE A TRANSITION TO FREEZING RAIN AND THEN
ALL RAIN BY 02Z. ICING WILL LAST LONGEST AT KBGM AND KRME, AND
SHORTEST AT KAVP AND KELM. SEE TAFS FOR SPECIFICS.
BEYOND THE CHANCES FOR ICING THROUGH LATE AFTERNOON, BIGGEST
AVIATION CONCERN EARLY TONIGHT WITH VERY STRONG SOUTHEAST WINDS AS
LOW AS 2,000 FEET ABOVE THE SURFACE. AFTER 06Z WINDS WHILE WINDS
WILL STILL BE STRONG, HIGHEST RISK FOR LLWS WILL BE ENDING. AS
THAT HAPPENS IFR CIGS WILL LOWER WITH TIME. ALT MINS WILL BECOME
LIKELY IN A MOIST SOUTHEAST FLOW. WIDESPREAD IFR CIGS CAN BE FOUND
WELL TO OUR SOUTHWEST AT THE PRESENT SO THIS IS A HIGH CONFIDENCE
FORECAST FOR IFR CONDITIONS. AT BGM, BASED ON SOUNDINGS AND
CURRENT OBS, AIRPORT MINS WILL BE APPROACHED BETWEEN 06Z AND 15Z.
IFR CIGS CONTINUE THROUGH THE END OF THE TAF PERIOD. ANOTHER
PERIOD OF LLWS IS POSSIBLE AFTER 15Z SUNDAY BUT TOO FAR OUT TO
INCLUDE IN THE TAFS JUST YET.
OUTLOOK...
MON/MON NGT...SCT SNOW SHOWERS AND BRIEF RESTRICTIONS WITH GUSTY
WINDS...BUT SIGNIFICANT RESTRICTIONS POSSIBLE KSYR-KRME FROM LAKE
EFFECT SNOW.
TUE/WED...RESTRICTIONS EXPECTED IN -SN AT ALL TERMINALS TUE AS
CLIPPER PASSES...THEN LAKE EFFECT -SHSN BRINGING RESTRICTIONS TO
NY TERMINALS ON WED.
THUR...MAINLY VFR BUT MVFR/IFR POSSIBLE NORTHERN TERMINALS IN LAKE
SNOW.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR PAZ040.
WINTER WEATHER ADVISORY UNTIL 8 PM EST THIS EVENING FOR PAZ038-
039-043-044-047-048-072.
NY...WINTER WEATHER ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR NYZ009-
036-037-045-046-057-062.
WINTER WEATHER ADVISORY UNTIL 8 PM EST THIS EVENING FOR
NYZ015>018-022>025-044-055-056.
&&
$$
SYNOPSIS...PCF
NEAR TERM...PCF/PVF
SHORT TERM...PCF
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1150 AM CST SAT JAN 3 2015
.DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW. /53/
&&
.AVIATION...
AFTERNOON FLIGHT CATEGORIES WILL REMAIN PROBLEMATIC ACROSS AREA
TERMINALS THANKS TO LOW CIGS. SATELLITE IMAGERY SHOWS A CLEARING
LINE NEARING A KAPY-KHBV LINE AT 03/1700 UTC. BASED ON CURRENT E/SE
PROGRESSION (AND THE LATEST HRRR DATA)...CIGS SHOULD START LIFTING
BY MID-AFTERNOON NEAR A KBKS-KEBG LINE. CIGS MAY NOT IMPROVE ACROSS
THE LOWER VALLEY AIRPORTS UNTIL AFTER 04/0000 UTC. SOME PATCHY -DZ
WILL BE POSSIBLE THROUGH 04/0000 UTC...MAINLY AT KBRO AND KHRL...BUT
LIMITED COVERAGE PRECLUDES MENTION IN THE 1800 UTC TAF PACKAGE.
WITH A DRIER AIRMASS EXPECTED TO MOVE INTO THE REGION TONIGHT...
CONDITIONS SHOULD LARGELY BE CAVOK AT AREA TERMINALS. WOULD NOT BE
SURPRISED TO SEE SOME BR OVERNIGHT GIVEN LIGHT WINDS AND MOIST
GROUND CONDITIONS. FORECAST CONFIDENCE ISN`T THAT GREAT...AND...AT
LEAST FOR NOW...I PLAN ON LEAVING THIS OUT OF THE LATEST TAF
PACKAGE. /53/
&&
.PREV DISCUSSION... /ISSUED 1059 AM CST SAT JAN 3 2015/
DISCUSSION...
UPPER LOW OVER THE TEXAS PANHANDLE CONTINUES TO EJECT INTO THE
CENTRAL PLAINS LATE THIS MORNING...AND PUSH THE TROUGH OF LOW
PRESSURE IN THE WESTERN GULF EAST. RADAR STILL SHOWS A SMATTERING
OF SHOWERS (MAINLY) OVER THE OFFSHORE GULF OF MEXICO WATERS...WITH
SOME PATCHY NUSAINCE DRIZZLE IN THE LOW CLOUDS HUGGING THE LOWER
VALLEY. MOST OF THE SHOWER ACTIVITY SHOULD REMAIN OFFSHORE THIS
AFTERNOON...WITH THE FOCUS FOR DEEPER...MORE ORGANIZED...
CONVECTION NORTHEAST OF OUR MARINE AREA.
TEMPERATURES WILL AGAIN BE PROBLEMATIC THIS AFTERNOON...THANKS TO
WIDESPREAD LOW CLOUDS OVER MOST OF THE REGION. THE CLEARING LINE
(SO-TO-SPEAK) WAS LOCATED JUST SOUTH OF A LINE FROM SAN YGNACIO...
TO AGUILARES...TO FREER AT 1030 THIS MORNING. EVEN IF THE CLEARING
LINE REACHES THE HEBBRONVILLE AND FALFURRIAS AREAS WITHIN THE NEXT
HOUR...AFTERNOON HIGHS WILL LIKELY BE COOLER THAN CURRENTLY
FORECAST. AS SUCH...SOME ADJUSTMENT HAS BEEN MADE IN THE HOURLY
TEMPERATURE GRIDS FOR THIS AFTERNOON. NEW NUMBERS ARE GIVEN BELOW
FOR YOUR PERUSAL.
ISC GRIDS HAVE BEEN SENT AND SHOULD BE POSTED TO THE INTERNET.
UPDATED TEXT PRODUCTS WILL BE COMING SHORTLY. /53/
PREV DISCUSSION... /ISSUED 542 AM CST SAT JAN 3 2015/
DISCUSSION...UPDATED FOR LATEST AVIATION DISCUSSION BELOW.
AVIATION...SATELLITE IMAGES AND SURFACE OBSERVATIONS INDICATE LOW
CLOUDS ACROSS MOST OF THE CWA THIS MORNING. CEILINGS WERE NEAR
400FT AT KPIL TO NEAR 2600FT AT KBKS. EXPECT MVFR TO IFR
CONDITIONS TO PREVAIL THROUGH 15Z ACROSS THE RIO GRANDE VALLEY
BEFORE A 500MB LOW ACROSS SOUTHEAST NEW MEXICO/WEST TEXAS MOVES
EASTWARD BRINGING DRIER AIR ALOFT ACROSS SOUTHWEST TX LATE THIS
MORNING INTO EARLY THIS AFTERNOON. CEILINGS WILL IMPROVE TO VFR
CONDITIONS FROM WEST TO EAST BETWEEN 15Z AND 21Z AS A RESULT.
PREV DISCUSSION... /ISSUED 316 AM CST SAT JAN 3 2015/
SHORT TERM.../TODAY THROUGH SUNDAY/...SATELLITE AND RADAR IMAGES
CONTINUE TO INDICATE ELEVATED CONVECTION ACROSS EASTERN PORTIONS
OF THE STATE THIS MORNING BUT NOT MUCH IN THE WAY OF SHOWERS OR
THUNDERSTORMS ACROSS THE RIO GRANDE PLAINS. WARMER TEMPERATURES
ALOFT ACROSS NORTHEAST MEXICO WITH SOUTHWEST TO WEST FLOW AT 850MB
MAY BE INHIBITING DEVELOPMENT ACROSS SOUTHWEST TEXAS. IN
ADDITION...WATER VAPOR SAT IMAGES INDICATE DRIER AIR ALOFT
BEGINNING TO MOVE ACROSS PORTIONS OF SOUTHWEST TX AS THE 500MB LOW
ACROSS SOUTHERN NEW MEXICO/WEST TX CONTINUES TO MOVE EASTWARD.
WITH THAT SAID...WILL CONTINUE TO MENTION A CHANCE OF SHOWERS
ACROSS THE COASTAL SECTIONS OF THE CWA THIS MORNING BEFORE DRIER
AIR MOVES INTO THE AREA THIS AFTERNOON FROM WEST TO EAST AS THE
STATIONARY FRONTAL BOUNDARY OFFSHORE THE LOWER TX COAST MOVES
EASTWARD. TEMPERATURES SHOULD FINALLY BEGIN TO WARM ACROSS
NORTHERN AND WESTERN PORTIONS OF THE CWA THIS AFTERNOON WHERE
SKIES SHOULD BEGIN TO CLEAR. COLDER TEMPS WILL LINGER ACROSS
SOUTHEAST PORTIONS OF THE CWA TODAY WHERE CLEARING IS NOT EXPECTED
UNTIL TONIGHT. RADIATIONAL COOLING WILL ALLOW TEMPERATURES TO FALL
INTO THE 40S ACROSS THE NORTHERN RANCHLANDS TONIGHT. TEMPS WILL
WARM INTO THE 60S SUNDAY BEFORE ANOTHER SURGE OF HIGH PRESSURE
BRINGS COLD AIR ACROSS THE CENTRAL UNITED STATES SOUTHWARD INTO
SOUTH TEXAS SUN AFTERNOON.
LONG TERM.../SUNDAY NIGHT THROUGH SATURDAY/...EARLY IN THE LONG TERM
PERIOD SOUTH TEXAS WILL BE UNDER THE CONTROL OF A SURFACE HIGH
PRESSURE WITH NORTH TO NORTHEAST FLOW ACROSS THE AREA. THIS HIGH
WILL BRING ENOUGH DRY AIR BEHIND IT TO PUSH DEEP MOISTURE SOUTHWARD
CLEARING THE VALLEY SUNDAY NIGHT INTO MONDAY. A RATHER WEAK CUT OFF
LOW DEVELOPS OVER BAJA CA MOVES WHILE RIDGE AMPLIFIES ACROSS THE W
COAST. HIGH PRESSURE WILL BUILD ACROSS GULF OF MEXICO RETURNING THE
EASTERLY FLOW ACROSS THE CWA THURSDAY AND WEDNESDAY. ABUNDANT MOISTURE
IS SHOWN ON BOTH MODELS OVER CENTRAL GULF OF MX SURGING INTO THE CWA
ENHANCING SHOWER ACTIVITY AND CLOUDY CONDITIONS. TEMPERATURES MONDAY
MORNING WILL BE IN THE 40S WARMING DURING THE DAY INTO THE 50S AND A
REPEAT EXPECTED INTO EARLY TUESDAY. AS THE EASTERLY FLOW RETURNS WITH
LESS CLOUD COVER THE TEMPERATURES WILL WARM UP INTO THE 60S TUESDAY
AFTERNOON.
THE RIDGE ACROSS THE WEST REMAINS THERE WEDNESDAY ALLOWING FOR ANOTHER
STRONG 1050 HIGH PRESSURE TO SURGE COLD CANADIAN AIR SOUTHWARD WED.
THE COLD FRONT WILL MAKE ITS WAY ACROSS THE CWA WEDNESDAY WITH STRONG
PRESSURE GRADIENT INCREASING NORTH TO NORTHEAST WINDS. MOISTURE IN THE
AREA WILL ENHANCE MORE LIGHT TO MODERATE PRECIPITATION WEDNESDAY INTO
THURSDAY. THE COLD AIR MASS ASSOCIATED WITH THIS FRONT WILL LOWER TEMPS
INTO THE LOW 40S EARLY THURSDAY AND ONLY REACH THE LOW 50S THURSDAY IN
THE AFTERNOON. RIDGE MIGRATES EAST ALLOWING FOR THIS HIGH PRESSURE TO
SHIFT EAST. THE NE TO E FLOW RETURNS SURGING GULF MOISTURE INTO THE CWA
AND AS A RESULT INCREASING THE PRECIPITATION POTENTIAL INTO THURSDAY
NIGHT AND FRIDAY. DURING THIS TIME ON THURSDAY THE CUT OFF LOW OVER BAJA
STARTS TO SHIFT EAST WEAKENING AS IT MOVES ACROSS NM. BY FRIDAY...THE
WEAK SHORTWAVE WILL ENHANCE MORE SHOWER ACTIVITY FRIDAY INTO SATURDAY
WITH THIS WEAK WAVE WITH TEMPERATURES GRADUALLY WARMING INTO THE 60S
FRIDAY AND SATURDAY.
MARINE...TODAY THROUGH SUNDAY...SEAS WERE NEAR 3 FEET WITH NORTH
TO NORTHWEST WINDS NEAR 18 KNOTS AT BUOY020 EARLY THIS MORNING.
MODERATE NORTHWEST WINDS WILL PREVAIL ACROSS THE COASTAL WATERS
TODAY AS HIGH PRESSURE BUILDS INTO THE WESTERN GULF OF MEXICO AS
THE STATIONARY FRONTAL BOUNDARY OFFSHORE THE LOWER TEXAS COAST
THIS MORNING MOVES EASTWARD. WINDS WILL VEER TO THE NORTH AND
NORTHEAST TONIGHT BEFORE A STRONGER SURGE OF HIGH PRESSURE BUILDS
INTO SOUTH TEXAS AND THE WESTERN GULF SUNDAY. WINDS AND SEAS WILL
INCREASE ACROSS THE COASTAL WATERS SUN MORNING INTO SUN AFTERNOON
AS A RESULT. SMALL CRAFT ADVISORIES WILL BE NEEDED FOR THE
OFFSHORE WATERS SUNDAY.
SUNDAY NIGHT THROUGH FRIDAY...AFTER THE FRONT EARLY SUNDAY...THE
SEAS BEGIN TO INCREASE AS THE GRADIENT STRENGTHENS. THE SEAS
BUILDING AND INCREASING WINDS WILL FAVOR FOR SCA CONDITIONS
ESPECIALLY SUNDAY NIGHT THROUGH MID MONDAY MORNING. LIGHT TO
MODERATE RAIN WILL BE POSSIBLE THROUGH EARLY IN THE WEEK AS SOME
LINGERING MOISTURE BEGINS TO INCREASE OVER THE LOWER GULF ZONES.
LIGHT TO MODERATE EASTERLY FLOW RETURNS TUESDAY WITH LOW SEAS BUT
THE MOISTURE OVER THE AREA WILL INCREASE THE CHANCE OF MORE
SHOWERS ACROSS THE LOWER TEXAS GULF WATERS. ANOTHER FRONT ARRIVES
WEDNESDAY RETURNING SCA CONDITIONS ACROSS THE GULF WITH MORE
POTENTIAL FOR RAIN AND OVERCAST SKIES. HIGH PRESSURE SHIFTS EAST
LATE THURSDAY INTO FRIDAY RETURNING NE TO E FLOW OVER THE GULF
WITH WEAKER PRESSURE GRADIENT.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...NONE.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WEATHER.GOV/RGV
SHORT TERM FORECASTER... BUTTS
LONG TERM FORECASTER... DRILLETTE
PSU/GRAPHICAST... BIRCHFIELD
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1100 AM CST SAT JAN 3 2015
.SHORT TERM...(TODAY AND TONIGHT)
ISSUED AT 311 AM CST SAT JAN 3 2015
CURRENTLY AS OF 09Z...WATER VAPOR LOOP AND RAP 500MB HEIGHT ANALYSIS
SHOWED STRONG SHORTWAVES OVER WEST CENTRAL ALBERTA...EASTERN
WASHINGTON STATE...NORTH CENTRAL MONTANA AND OVER THE FORECAST AREA.
ALSO AN UPPER LOW WAS PRESENT OVER NEW MEXICO. MOISTURE HAS BEEN
STREAMING NORTHWARD TOWARDS THE FORECAST AREA...DUE TO A SOUTHWARD
PULL AHEAD OF BOTH THE UPPER LOW AND THE STRONG SHORTWAVE OVER THE
AREA. PRECIPITABLE WATER PER GOES ANALYSIS HAS CLIMBED TO 0.5 INCH
OVER SOUTHERN WI...AND 1 INCH ALONG I-70 IN MO AND IL. THIS
MOISTURE...COMBINED WITH ISENTROPIC LIFT AND DPVA FORCING AHEAD OF
THE SHORTWAVE OVER THE FORECAST AREA...HAS RESULTED IN SNOW ACROSS
THE SOUTHEAST HALF OR SO OF THE FORECAST AREA. THE SNOW HAS NOW
PUSHED INTO MAINLY WI...WITH SUBSIDENCE AND DRYING WORKING IN FROM
THE WEST BEHIND THE SHORTWAVE. MEANWHILE...FARTHER WEST...A SURFACE
LOW HAS DEVELOPED NEAR BISMARCK ND DOWNSTREAM OF THE MONTANA
SHORTWAVE. 925MB TEMPS AHEAD OF THE LOW ARE GENERALLY 0 TO -6C
ACROSS MUCH OF THE DAKOTAS EASTWARD INTO WI. HOWEVER...-20C TO -30C
READINGS WERE LURKING TO THE NORTH ACROSS MUCH OF SOUTHERN CANADA.
NORTHERLY WINDS BEHIND THE LOW HAS BEGUN BRINGING THIS COLD AIR
SOUTH WITH READINGS OVER NORTHERN NORTH DAKOTA NOW IN THE SINGLE
DIGITS BELOW ZERO.
TODAY CONTINUES TO LOOK MUCH QUIETER ON THE PRECIPITATION SIDE OF
THINGS...RESULTING MOSTLY FROM DECENT SUBSIDENCE AND DRYING
OCCURRING IN THE WAKE OF THE SHORTWAVE CURRENTLY CROSSING THE
FORECAST AREA. ANY LINGERING SNOW OVER WI SHOULD PUSH OFF TO THE
EAST OF THE AREA BY 15Z. ALTHOUGH WE DO LOSE ICE IN THE CLOUDS WITH
THE PASSAGE OF THE SHORTWAVE...WE ALSO LOSE THE LIFT...SO THE
POTENTIAL FOR FREEZING DRIZZLE IS FURTHER REDUCED. MOST 03.00Z
GUIDANCE IS NOW MOSTLY DRY FOR THE FORECAST AREA TODAY AND HAVE
FOLLOWED SUIT. 925MB TEMPS STAY RELATIVELY MILD TODAY...-2 TO -4C.
IF WE WERE SUNNY TODAY...HIGHS COULD POP INTO THE 40S OVER SNOW FREE
AREAS. HOWEVER...A SOUTHERLY FLOW LOOKS TO ADVECT IN LOW CLOUDS FROM
MO AND IL THROUGH THE FORECAST AREA...WHICH GET TRAPPED UNDER THE
SUBSIDENCE INVERSION. IN FACT...CANNOT RULE OUT SOME FOG THIS
MORNING OVER THE HIGHER TERRAIN. THESE CLOUDS SHOULD KEEP HIGHS IN
THE UPPER 20S TO MID 30S...COLDEST OVER SNOW PACK LOCATIONS.
NOW FOR TONIGHT...A LOT MORE IS GOING ON.
1. SNOW LOOKS LIKELY. WE SHOULD BEGIN TO SEE A SNOW BAND SET UP THIS
AFTERNOON FROM CENTRAL NEBRASKA INTO NORTHEAST MN. THIS BAND...
ASSOCIATED WITH MID LEVEL FRONTOGENESIS AND DPVA DOWNSTREAM OF THE
CURRENT MONTANA SHORTWAVE TRACKING EAST...LOOKS TO MOVE INTO THE
NORTHWEST HALF OF THE FORECAST AREA DURING THE EVENING...THEN MARCH
EAST THROUGH THE REST OF THE FORECAST AREA OVERNIGHT. MODELS ARE IN
PRETTY GOOD AGREEMENT IN PRODUCING A TOTAL OF 0.10-0.15 INCHES OF
QPF WITH THE BAND...WHICH SEEMS REASONABLE WHEN LOOKING AT THE
FORCING AND 0.3-0.4 INCHES OF PRECIPITABLE WATER. WITH SNOW RATIOS
OF 15-18 TO 1 RANGE IN THE BAND...DUE TO COLDER AIR FLOWING IN
ALLOWING FOR UPWARDS OF 100MB OF EFFECTIVE DENDRITIC GROWTH...A
SOLID 1 TO 2 INCHES SEEMS REASONABLE WITH A 3 INCH AMOUNT POSSIBLE.
2. NORTHWEST WINDS ARE GOING TO INCREASE THROUGH THE NIGHT. THIS IN
RESPONSE TO THE UPPER LOW EJECTING OUT OF NEW MEXICO AND PHASING
WITH THE SHORTWAVE COMING THROUGH THE FORECAST AREA TONIGHT...
RESULTING IN A DEEPENING SURFACE LOW LIFTING INTO THE EASTERN GREAT
LAKES. 925MB WINDS INCREASE TO 35-40 KT BY 12Z SUNDAY...WHICH WITH
PRESSURES RISING RAPIDLY AS THOSE WINDS DRIVE IN COLDER AIR...A GOOD
AMOUNT OF THIS WIND SHOULD MIX DOWN. 20-25 KT WINDS FROM MAV
GUIDANCE OVER THE HIGHER TERRAIN OF SOUTHEAST MN/NORTHEAST IA SEEMS
REASONABLE...WITH GUSTS OF 30-35 KT. GIVEN THE FLUFFIER SNOW
TONIGHT...SOME BLOWING AND DRIFTING IS LIKELY WITH THESE WINDS
COMING THROUGH.
3. TEMPERATURES AND WIND CHILLS PLUMMETING OVERNIGHT. 925MB TEMPS
TANK FROM THE -2 TO -4C AT 00Z TO -10 TO -20C BY 12Z...COLDEST
NORTHWEST. THIS SHOULD DROP TEMPERATURES INTO THE SINGLE DIGITS AND
TEENS...AND EVEN BELOW ZERO IN SOME OF SOUTHEAST MN BY SUNRISE. WIND
CHILLS COULD BE APPROACHING ADVISORY CRITERIA BY 12Z SUNDAY IN
PORTIONS OF SOUTHEAST MN.
HAVE ISSUED A WINTER WEATHER ADVISORY FOR THE WESTERN PORTIONS OF
SOUTHEAST MN AND NORTHEAST IA...FROM 06-12Z SUNDAY...TO HANDLE THE
NEAR ADVISORY WINDS...FALLING SNOW...WIND CHILLS APPROACHING
ADVISORY CRITERIA AND BLOWING/DRIFTING SNOW.
.LONG TERM...(SUNDAY THROUGH FRIDAY)
ISSUED AT 311 AM CST SAT JAN 3 2015
MAIN LONG TERM FOCUSES ARE ON ARCTIC AIR AND A POSSIBLE ACCUMULATING
FLUFFY SNOW EVENT FOR MONDAY NIGHT.
THE POOL OF ARCTIC AIR SITUATED CURRENTLY ACROSS MUCH OF SOUTHERN
CANADA LOOKS TO INVADE THE REGION SUNDAY AND SUNDAY NIGHT...THANKS
TO THE SHORTWAVE OVER WEST CENTRAL ALBERTA DIGGING INTO THE REGION.
925MB TEMPS PLUMMET TO -20 TO -25C BY 00Z MONDAY ON A BRISK
NORTHWEST WIND...AND FURTHER LOWERING TO -24 TO -28C BY 12Z MONDAY.
TEMPERATURES THAT BEGAN FALLING TONIGHT WILL CONTINUE TO DO SO
THROUGH THE DAY SUNDAY AND INTO SUNDAY NIGHT. COMBINED WITH THE
BRISK NORTHWEST WIND...WIND CHILL ADVISORIES AND POSSIBLY A FEW
WARNINGS ARE GOING TO BE NECESSARY. THE ARCTIC AIR MODIFIES SOMEWHAT
ON MONDAY WITH 925MB TEMPS CLIMBING TO -18 TO -22C BY 00Z...ENOUGH
THAT WIND CHILL HAZARDS SHOULD BE ALLOWED TO END BY 20Z.
ON MONDAY NIGHT...A FAST MOVING BUT POTENT SHORTWAVE IS PROGGED TO
AFFECT THE REGION. GOOD MODEL CONSENSUS EXISTS FOR STRONG MID LEVEL
FRONTOGENESIS WITH DPVA ENHANCEMENT AND UPPER LEVEL DIVERGENCE TO
ACCOMPANY THE SHORTWAVE. QPF FORECASTS ARE IN THE 0.25-0.4 INCH
RANGE...WITH UPWARDS OF 200 MB OF EFFECTIVE DENDRITIC SNOW GROWTH.
THIS WOULD MEAN EASILY 20 TO 1 RATIOS...QUITE FLUFFY SNOW...AND
ACCUMULATIONS IN THE 4 TO 8 INCH RANGE. HOWEVER...PLACEMENT OF THE
BAND IS BECOMING A SERIOUS ISSUE AS THERE HAS BEEN A TREND FOR THE
SHORTWAVE TO TRACK FARTHER SOUTHWEST THROUGH IOWA IN THE 03.00Z
GFS/CANADIAN/ECMWF. THIS TAKES THE HEAVIER SNOW FARTHER SOUTH. SO
ITS HARD TO SAY RIGHT NOW EXACTLY HOW MUCH SNOW WE WILL SEE. AT THE
MOMENT HAVE 2 TO 5 INCHES...HIGHEST SOUTH OF I-90. EXPECT THESE
AMOUNTS TO CHANGE DUE TO BAND PLACEMENT AND INTENSITY. THE
FARTHER SOUTHWEST TREND HAS RESULTED IN LOWERED PRECIPITATION
CHANCES NORTH OF I-94.
PRECIPITATION SHOULD BE OUT OF THE AREA FOR TUESDAY...WITH MORE
ARCTIC AIR BEGINNING TO PLUNGE INTO THE REGION IN THE WAKE OF THE
SYSTEM...ESPECIALLY TUESDAY NIGHT. 925MB TEMPS TANK FROM -10 TO -16C
AT 12Z TO -16 TO -20C BY 00Z WEDNESDAY AND TO -25 TO -30C BY 12Z
WEDNESDAY. 925MB WINDS ALSO PROGGED IN THE 35-45 KT RANGE. LUCKILY
THE SOUNDING PROFILE MAY END UP BEING ISOTHERMAL TO HELP LIMIT
MIXING OF THESE STRONGER WINDS...BUT ITS GOING TO BE BRISK
NONETHELESS. MORE WIND CHILL ADVISORIES AND WARNINGS ARE LIKELY FOR
TUESDAY NIGHT INTO WEDNESDAY. ADDITIONALLY...THE WIND WILL HELP BLOW
THE RECENT FLUFFY SNOW AROUND SO ADDED SOME BLOWING SNOW.
BRIEF UPPER RIDGING DROPS DOWN OVER THE FORECAST AREA WEDNESDAY
NIGHT INTO THURSDAY...BRINGING SOMEWHAT WARMER AIR INTO THE FORECAST
AREA. HOWEVER...COMBINATION OF THE WINDS AND LINGERING ARCTIC AIR
LIKELY MEAN A CONTINUATION OF WIND CHILL HAZARDS INTO THURSDAY
MORNING. RIGHT NOW HAVE THURSDAY DRY...BUT THE WARM ADVECTION MAY BE
ENOUGH TO PRODUCE SOME LIGHT SNOW AND LATER FORECASTS COULD HAVE TO
INTRODUCE PRECIPITATION CHANCES. ANOTHER ARCTIC SURGE LOOKS POISED
TO FOLLOW FOR THURSDAY NIGHT THROUGH FRIDAY...NOT AS INTENSE AS
EARLIER ONES THIS WEEK BUT STRONG ENOUGH TO POSSIBLY NEED A FEW MORE
WIND CHILL ADVISORIES.
FINALLY...LOOKING AHEAD...THERE IS SIGNAL SHOWING UP TO BREAK OUT OF
THE ARCTIC REGIME FOR NEXT WEEKEND. IN FACT...THERE IS SIGNAL IN
BOTH THE CFS AND ECMWF TO EVEN GO BACK ABOVE NORMAL.
&&
.AVIATION...(FOR THE 18Z TAFS THROUGH 18Z SUNDAY AFTERNOON)
ISSUED AT 1100 AM CST SAT JAN 3 2015
BRIEF BREAK FROM THE LOW CLOUDS THIS MORNING...BUT IFR/MVFR QUICKLY
ADVANCING IN FROM THE SOUTH. SOME VSBY RESTRICTIONS WITH THIS BATCH
OF CLOUDS.
SNOW MOVES IN TONIGHT...WITH 1 TO 2 INCHES OF ACCUMULATION. SUB 1SM
VSBYS AND CIGS UNDER 1 KFT SHOULD ACCOMPANY THE MAIN SNOW BAND. IN
ADDITION...WINDS ARE GOING TO BECOME STRONG AND GUSTY...SUSTAINED 20
KTS WITH 30+ GUSTS AT KRST. THIS WILL BLOW THE FALLEN SNOW...AND
SHOULD KEEP VSBYS AT LEAST IN THE MVFR CATEGORY AT KRST THROUGH
SUNDAY MORNING - AFTER THE SNOW STOPS. RH FIELDS SUGGEST A BREAK
FROM THE LOW CIGS LATE MORNING...BUT A BAND OF STRATUS COULD MOVE
BACK IN FOR A FEW HOURS SUN AFTERNOON.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
MN...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR MNZ086-087-094-095.
IA...WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM CST SUNDAY
FOR IAZ008>010-018-019-029.
&&
$$
SHORT TERM...AJ
LONG TERM....AJ
AVIATION.....RIECK