Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 12/26/11
AREA FORECAST DISCUSSION
NWS DENVER CO
150 PM MST SAT DEC 24 2011
.SHORT TERM...A WIDE BAND OF CIRRUS CLOUDS ON THE LEADING SIDE OF A
SOUTHWEST-NORTHEAST ORIENTED UPPER LEVEL RIDGE ADVANCING SLOWLY
SOUTHWARD OUT OF WYOMING MARKS LEADING EDGE OF WARMER AIR ALOFT.
BENEATH THESE CLOUDS SWLY SFC WINDS WERE GUSTING 20-30KTS ACROSS
SERN WYOMING WHILE WINDS ALOFT WERE NELY 70-90 KTS ACCORDING TO
MEDICINE BOW PROFILER. DURING THE NEXT SEVERAL HOURS THIS
ENVIRONMENT SHIFTS SOUTHWARD OVER THE FORECAST AREA. RUC INDICATING
PRESSURE FALLS ACROSS THE AREA CENTERED ALONG THE MOSQUITO RANGE IN
PARK COUNTY. SHOULD BE JUST A MATTER OF TIME BEFORE THE NRN FRONT
RANGE FOOTHILLS SEE THE DEVELOPMENT OF GUSTY WEST-SOUTHWEST WINDS...
WITH GUSTS OF 30-35KTS POSSIBLE THIS EVENING. SHOULD SEE THESE GUSTY
DOWNSLOPE WINDS MIGRATING SOUTHWARD ALONG THE FOOTHILLS THIS
EVENING...BUT SPEEDS PROBABLY NOT AS STRONG THOSE EXPECTED UP NEAR
THE WYOMING BORDER. GUSTY WLY WINDS ALSO A POSSIBILITY THIS EVENING
ALONG LEE SLOPES OF THE GORE RANGE IN JACKSON COUNTY AND MOSQUITO
RANGE IN PARK COUNTY.
OTHERWISE...SCT-BKN CIRRUS CLOUDS BLOW SOUTH OF THE AREA LATER THIS
EVENING WHICH ALLOWS FOR ANOTHER NIGHT OF CHILLY TEMPERATURES ESPLY
IN THE MTN VALLEYS WHERE STRONG NIGHTTIME INVERSIONS WILL FORM WITH
DARKNESS. AS USUAL WILL SEE COLDEST READINGS ON THE PLAINS IN LOW
LYING AREAS SUCH AS ALONG THE SOUTH PLATTE AND THE AREA AROUND
LIMON. WHEREAS A STEADY DOWNSLOPE FLOW OFF THE FOOTHILLS WILL KEEP
OVERNIGHT TEMPERATURES ON THE MILD SIDE ALONG THE BASE OF THE
FOOTHILLS.
ON CHRISTMAS DAY...WINDS BOTH SFC AND ALOFT EASE AS THE UPPER RIDGE
PASSES OVERHEAD. SEE FEW IF ANY CLOUDS AND SLIGHTLY WARMER
TEMPERATURES AS WARMING CONTINUES ALOFT. WARMEST TEMPS EXPECTED
ALONG THE BASE OF THE FOOTHILLS AND OUT ACROSS THE NERN CORNER OF
THE STATE WHERE THERE/S LITTLE IF ANY SNOW COVER. COULD SEE THE
MERCURY NUDGING THE 50 DEG MARK IN THESE AREAS. MOS TEMPERATURE
GUIDANCE STILL LOOKS A BIT TOO WARM FOR THOSE AREAS INCLUDING THE
DENVER AREA WITH OUR DEEP SNOW COVER. SO WILL SHAVE MOS TEMPS
BACK A FEW DEGS.
.LONG TERM...FOR THE UPCOMING WEEK ACROSS COLORADO THE FLOW WILL BE
A RATHER STRONG NORTHWEST FLOW PATTERN. THIS WILL RESULT IN A DRY
PATTERN ACROSS THE PLAINS...BUT PERIODS OF GUSTY WINDS AND CHANCES
OF SNOW IN THE MOUNTAINS. MOISTURE WILL BE INCREASING ACROSS THE
MOUNTAINS BY MID WEEK WITH SEVERAL JET SEGMENTS TRAVERSING THE STATE.
TO START THE WEEK ON MONDAY...THE TRANSITION TO THE NORTHWEST FLOW
PATTERN WILL BEGIN AS A WEAK WAVE AND FRONTAL SYSTEM MOVES ACROSS
THE NORTHERN HIGH PLAINS. A WEAK SURGE WILL MOVE ACROSS NORTHEAST
COLORADO RESULTING IN COOLER TEMPERATURES BY MONDAY AFTERNOON. CROSS
SECTIONS SHOWING SOME INCREASING DOWNSLOPE WINDS OVER EAST SLOPES
ESPECIALLY BY MONDAY NIGHT AND CONTINUING TUESDAY. GIVEN STRONG
CROSS BARRIER FLOW MAY SEE SOME GUSTS IN THE 40-50KT RANGE OVER
HIGHER EAST SLOPES. SOME SHALLOW MOISTURE WILL RESULT IN SOME
SCATTERED SNOW SHOWERS OVER HIGHER WEST SLOPES OF THE MOUNTAINS. A
STRONGER SYSTEM WITH DEEPER MOISTURE WILL MOVE INTO THE MOUNTAINS ON
WEDNESDAY WITH A BETTER CHANCE OF SNOW AS STRONGER 110KT JET CORE
MOVES INTO CENTRAL COLORADO. ACROSS NORTHEAST COLORADO...THE
DOWNSLOPE FLOW WILL ALLOW TEMPERATURES TO WARM TO SLIGHTLY ABOVE
NORMAL TEMPERATURES FOR THIS TIME OF YEAR.
CONTINUED MODERATE TO STRONG NORTHWEST FLOW THROUGH SATURDAY WILL
RESULT IN A SLIGHT CHANCE OF SNOW FOR THE MOUNTAINS THROUGH THE
PERIOD AND GUSTY WINDS.
&&
.AVIATION...VFR CONDITIONS EXPECTED THROUGH CHRISTMAS DAY WITH A
TYPICAL DRAINAGE WIND PATTERN PREVAILING AREAWIDE. ALTHOUGH BJC
COULD SEE W-SWLY WINDS OF 10-15KTS FOR A TIME THIS EVENING. HERE TOO
WINDS SHOULD WEAKEN AND GO DRAINAGE BY 06Z.
&&
.BOU WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
BAKER/ENTREKIN
AREA FORECAST DISCUSSION
NWS ALBANY NY
1222 PM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH TODAY. CANADIAN HIGH PRESSURE
WILL BRIEFLY BUILD IN LATE BRINGING INCREASING SUNSHINE BUT
SEASONABLY COLD TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE
TONIGHT INTO SUNDAY. A CLIPPER TYPE STORM WILL BRING SOME LIGHT SNOW
TO MAINLY THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
CLOUDS HAVE DIMINISHED...BUT COLD AIRMASS STILL IN PLACE WITH
RELATIVELY LIGHT WINDS. JUST A FEW MINOR CHANGES TO FORECAST
THROUGH THIS AFTERNOON.
PREV AFD BELOW...
AS OF 950 AM...A BAND OF CLOUDS ASSOCIATED WITH A MID/UPPER LEVEL
TROF AXIS AS WELL AS A MOISTURE CONTRIBUTION FROM LAKE CHAMPLAIN
IN NORTHEAST FLOW REGIME IN PLACE FROM AROUND THE GLENS FALLS AREA
SOUTHWARD THROUGH THE CAPITAL DISTRICT AND BERKSHIRES. SCATTERED
FLURRIES HAVE BEEN COMMON THIS MORNING...SO WILL ADD MENTION TO
FORECAST. A FEW SNOW SHOWERS BRINGING DOWN VISIBILITIES TO AROUND
2-3 MILES AROUND GLENS FALLS SO WILL MENTION 20 POPS FOR ISOLATED
SNOW SHOWERS THERE. THE TROF AXIS SHOULD MOVE EAST OF THE REGION
RATHER QUICKLY BY EARLY AFTERNOON...SO FLURRIES AND CLOUD COVER
SHOULD GRADUALLY DIMINISH LEAVING MAINLY CLEAR SKIES BY LATE IN
THE DAY.
PREVIOUS NEAR TERM DISCUSSIONS...
AS OF 630 AM...THE BACKDOOR FRONT NOW BEEN IS THROUGH ALBANY...STILL
HEADING SOUTH. THIS FRONT DOES HAVE SOME CLOUDS...BUT VERY LITTLE IF
ANY SNOW SHOWERS. THIS FRONT SHOULD KEEP MOVING SOUTH AND THE CLOUDS
LOOK AS IF THEY WILL SLOWLY DISSIPATE DURING THE NEXT FEW HOURS.
TEMPERATURES HAVE STALLED IN SOME CASES...BUT THEY ACTUALLY MIGHT
DROP A FEW MORE DEGREES EVEN AFTER SUNRISE.
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COAST
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSTLY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
NORTHERLY FLOW AND MOISTURE OF LAKES CHAMPLAIN AND GEORGE CONTINUE
TO PRODUCE BKN/OVC MVFR/VFR CLOUDS AT KGFL/KALB. AS THE ATMOSPHERE
OVER THE REGION CONTINUES TO DRY OUT...THE STRATOCU DECK OVER THE
TAFS WILL LIKELY BREAK UP BY LATE THIS MORNING...WITH MAINLY CLEAR
SKIES THIS AFTERNOON AND MOST OF TONIGHT. AFTER 06Z TONIGHT...MID/HI
CLOUDS WILL RETURN AHEAD OF THE NEXT WEAK UPPER LEVEL SYSTEM.
AS KPOU...EXPECT BKN MID/HI CLOUDS THIS MORNING...THEN MAINLY CLEAR
SKIES THIS AFTERNOON AND TONIGHT.
SURFACE WINDS WILL BE NORTH TO NORTHEAST TODAY AT 5 TO 10 KTS...THEN
BECOME CALM TO VERY LIGHT FOR MOST OF TONIGHT. LATE TONIGHT...
KGFL/KALB ARE LIKELY TO PICK UP A LIGHT SOUTH WIND AT 6 KTS OR LESS.
OUTLOOK...
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...NAS
NEAR TERM...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
952 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH TODAY. CANADIAN HIGH PRESSURE
WILL BRIEFLY BUILD IN LATE BRINGING INCREASING SUNSHINE BUT
SEASONABLY COLD TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE
TONIGHT INTO SUNDAY. A CLIPPER TYPE STORM WILL BRING SOME LIGHT SNOW
TO MAINLY THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 950 AM...A BAND OF CLOUDS ASSOCIATED WITH A MID/UPPER LEVEL
TROF AXIS AS WELL AS A MOISTURE CONTRIBUTION FROM LAKE CHAMPLAIN
IN NORTHEAST FLOW REGIME IN PLACE FROM AROUND THE GLENS FALLS AREA
SOUTHWARD THROUGH THE CAPITAL DISTRICT AND BERKSHIRES. SCATTERED
FLURRIES HAVE BEEN COMMON THIS MORNING...SO WILL ADD MENTION TO
FORECAST. A FEW SNOW SHOWERS BRINGING DOWN VISIBILITIES TO AROUND
2-3 MILES AROUND GLENS FALLS SO WILL MENTION 20 POPS FOR ISOLATED
SNOW SHOWERS THERE. THE TROF AXIS SHOULD MOVE EAST OF THE REGION
RATHER QUICKLY BY EARLY AFTERNOON...SO FLURRIES AND CLOUD COVER
SHOULD GRADUALLY DIMINISH LEAVING MAINLY CLEAR SKIES BY LATE IN
THE DAY.
PREVIOUS NEAR TERM DISCUSSIONS...
AS OF 630 AM...THE BACKDOOR FRONT NOW BEEN IS THROUGH ALBANY...STILL
HEADING SOUTH. THIS FRONT DOES HAVE SOME CLOUDS...BUT VERY LITTLE IF
ANY SNOW SHOWERS. THIS FRONT SHOULD KEEP MOVING SOUTH AND THE CLOUDS
LOOK AS IF THEY WILL SLOWLY DISSIPATE DURING THE NEXT FEW HOURS.
TEMPERATURES HAVE STALLED IN SOME CASES...BUT THEY ACTUALLY MIGHT
DROP A FEW MORE DEGREES EVEN AFTER SUNRISE.
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COAST
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSTLY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
NORTHERLY FLOW AND MOISTURE OF LAKES CHAMPLAIN AND GEORGE CONTINUE
TO PRODUCE BKN/OVC MVFR/VFR CLOUDS AT KGFL/KALB. AS THE ATMOSPHERE
OVER THE REGION CONTINUES TO DRY OUT...THE STRATOCU DECK OVER THE
TAFS WILL LIKELY BREAK UP BY LATE THIS MORNING...WITH MAINLY CLEAR
SKIES THIS AFTERNOON AND MOST OF TONIGHT. AFTER 06Z TONIGHT...MID/HI
CLOUDS WILL RETURN AHEAD OF THE NEXT WEAK UPPER LEVEL SYSTEM.
AS KPOU...EXPECT BKN MID/HI CLOUDS THIS MORNING...THEN MAINLY CLEAR
SKIES THIS AFTERNOON AND TONIGHT.
SURFACE WINDS WILL BE NORTH TO NORTHEAST TODAY AT 5 TO 10 KTS...THEN
BECOME CALM TO VERY LIGHT FOR MOST OF TONIGHT. LATE TONIGHT...
KGFL/KALB ARE LIKELY TO PICK UP A LIGHT SOUTH WIND AT 6 KTS OR LESS.
OUTLOOK...
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/JPV
NEAR TERM...HWJIV/JPV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...SND/HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
645 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM...THE BACKDOOR FRONT NOW BEEN IS THROUGH ALBANY...STILL
HEADING SOUTH. THIS FRONT DOES HAVE SOME CLOUDS...BUT VERY LITTLE IF
ANY SNOW SHOWERS. THIS FRONT SHOULD KEEP MOVING SOUTH AND THE CLOUDS
LOOK AS IF THEY WILL SLOWLY DISSIPATE DURING THE NEXT FEW HOURS.
TEMPERATURES HAVE STALLED IN SOME CASES...BUT THEY ACTUALLY MIGHT
DROP A FEW MORE DEGREES EVEN AFTER SUNRISE.
*************PREVIOUS NEAR TERM FORECAST***********
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COAST
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSTLY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
NORTHERLY FLOW AND MOISTURE OF LAKES CHAMPLAIN AND GEORGE CONTINUE
TO PRODUCE BKN/OVC MVFR/VFR CLOUDS AT KGFL/KALB. AS THE ATMOSPHERE
OVER THE REGION CONTINUES TO DRY OUT...THE STRATOCU DECK OVER THE
TAFS WILL LIKELY BREAK UP BY LATE THIS MORNING...WITH MAINLY CLEAR
SKIES THIS AFTERNOON AND MOST OF TONIGHT. AFTER 06Z TONIGHT...MID/HI
CLOUDS WILL RETURN AHEAD OF THE NEXT WEAK UPPER LEVEL SYSTEM.
AS KPOU...EXPECT BKN MID/HI CLOUDS THIS MORNING...THEN MAINLY CLEAR
SKIES THIS AFTERNOON AND TONIGHT.
SURFACE WINDS WILL BE NORTH TO NORTHEAST TODAY AT 5 TO 10 KTS...THEN
BECOME CALM TO VERY LIGHT FOR MOST OF TONIGHT. LATE TONIGHT...
KGFL/KALB ARE LIKELY TO PICK UP A LIGHT SOUTH WIND AT 6 KTS OR LESS.
OUTLOOK...
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...SND/HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
631 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 630 AM...THE BACKDOOR FRONT NOW BEEN IS THROUGH ALBANY...STILL
HEADING SOUTH. THIS FRONT DOES HAVE SOME CLOUDS...BUT VERY LITTLE IF
ANY SNOW SHOWERS. THIS FRONT SHOULD KEEP MOVING SOUTH AND THE CLOUDS
LOOK AS IF THEY WILL SLOWLY DISSIPATE DURING THE NEXT FEW HOURS.
TEMPERATURES HAVE STALLED IN SOME CASES...BUT THEY ACTUALLY MIGHT
DROP A FEW MORE DEGREES EVEN AFTER SUNRISE.
*************PREVIOUS NEAR TERM FORECAST***********
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COAST
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSTLY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...SND/HWJIV
AREA FORECAST DISCUSSION
NWS ALBANY NY
500 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
A COUPLE OF FAST MOVING WEATHER SYSTEMS WILL AFFECT THE REGION
DURING THE LONG TERM PERIOD. THE FIRST WILL MOVE RAPIDLY FROM THE
SOUTHERN PLAINS ON MONDAY AFTERNOON...TO OFF THE NEW ENGLAND COSAT
BY SHORTLY AFTER MIDNIGHT TUESDAY NIGHT. THE RAPID MOVEMENT OF THIS
LOW PRESSURE SYSTEM WILL RESULT IN A MOSLTY CLEAR SKY MONDAY NIGHT
WITH LOWS IN THE UPPER TEENS AND 20S. CLOUDS WILL RAPIDLY INCREASE
LATE MONDAY NIGHT...WITH PCPN BEGINNING TO SPREAD FROM WEST TO EAST
ACROSS THE FORECAST AREA AROUND MID MORNING TUESDAY...WITH
WIDESPREAD PCPN LIKELY ACROSS THE ENTIRE FORECAST AREA BY EARLY OR
MID AFTERNOON. ONCE AGAIN...DESPITE MOST MODEL RUNS PASSING THIS LOW
TO OUR SOUTH...THE AIR OVER THE REGION REMAINS RELATIVELY MILD SO
RAIN RATHER THAN SNOW IS LIKELY TO BE THE PREDOMINANT PCPN TYPE.
HAVE FORECAST LIKELY POPS IN ALL AREAS TUESDAY AFTERNOON INTO EARLY
TUESDAY NIGHT...THEN DECREASING POPS AFTER MIDNIGHT. BASED ON TEMP
FORECASTS (HIGHS GENERALLY BETWEEN 35 AND 45 ON TUESDAY) WOULD
EXPECT VALLEY LOCATIONS FROM ALBANY SOUTH TO BE MAINLY RAIN...WITH
OTHER AREAS A MIX OF SNOW AND RAIN...RESULTING IN AT LEAST SOME
ACCUMULATIONS FOR MOST HIGHER TERRAIN AND NORTHERN AREAS. AFTER THE
LOW GOES BY TUESDAY NIGHT...EXPECT A GUSTY NORTHWEST WIND WITH LOWS
IN THE 20S TO LOWER 30S.
SKIES WILL QUICKLY CLEAR BEHIND THIS LOW PRESSURE SYSTEM ON
WEDNESDAY AS THE SURFACE FLOW BEHIND THE LOW IS FORECAST TO BECOME
MORE NORTHERLY THAN NORTHWEST OR WEST...SO LAKE EFFECT SNOW SHOWERS
SHOULD NOT BE A PROBLEM FOR THE ALB FORECAST AREA ON WEDNESDAY.
HIGHS WEDNESDAY WILL BE IN THE UPPER 20S AND 30S.
HIGH PRESSURE WILL BE IN CONTROL WEDNESDAY NIGHT INTO THURSDAY WITH
MAINLY CLEAR TO PARTLY CLOUDY SKIES. LOWS WEDNESDAY NIGHT WILL
GENERALLY BE BETWEEN 10 AND 20...WITH HIGHS THURSDAY IN THE UPPER
20S AND 30S ONCE AGAIN.
AN UPPER LEVEL TROF WITH ONLY A WEAK SURFACE REFLECTION IS FORECAST
TO MOVE ACROSS THE REGION LATE THURSDAY NIGHT AND FRIDAY. NOT MUCH
MOISTURE WITH THIS SYSTEM SO HAVE ONLY FORECAST SLIGHT TO LOW
CHANCE POPS THURSDAY NIGHT AND FRIDAY...WITH SOME AREAS FORECAST TO
BE DRY ON FRIDAY. SURFACE TO MID LEVEL TEMPS WILL BE COLDER...SO
WHATEVER PCPN DOES FALL WITH THIS EVENT...EXPECT IT TO BE MAINLY
SNOW. LOWS THURSDAY NIGHT WILL BE IN THE MID TEENS TO MID 20S...
HIGHS FRIDAY 30 TO 40.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...GJM
HYDROLOGY...HWJIV/SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
430 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COMING SOON.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...
AVIATION...GJM
HYDROLOGY...HWJIV/SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
410 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING AND SURFACE HIGH PRESSURE WILL BE EXITING LATE
TONIGHT AND WEAK WARM ADVECTION WILL BEGIN. BEFORE THAT HAPPENS...IT
APPEARS THAT THERE WILL BE AN OPPORTUNITY FOR TEMPERATURES TO
QUICKLY FALL AFTER SUNDOWN UNDER A MAINLY CLEAR SKY WITH LITTLE OR
NO WIND. WE BELIEVE THAT THE NUMERICAL GUIDANCE WAS NOT QUITE FAST
ENOUGH COOLING MANY PLACES OFF DURING THE EVENING. THEREFORE WE
DECIDED TO GO LOWER THAN ALL GUIDANCE FOR OVERNIGHT LOWS...BY A FEW
DEGREES. WE ALSO BELIEVE LOW TEMPERATURES WILL LIKELY OCCUR AROUND
MIDNIGHT. THEY WILL MAINLY BE IN THE TEENS...(AROUND WELL SOUTH OF
ALBANY...AND SINGLE NUMBERS WELL TO THE NORTH OF ALBANY).
AFTER MIDNIGHT...WARM AIR ADVECTION CLOUDS AND A SOUTHERLY BREEZE
(ESPECIALLY OVER THE HIGHER TERRAIN) WILL BRING A HALT TO THE
TEMPERATURE FREE FALL AND IN SOME CASES...THEY MIGHT RISE A FEW
DEGREES BY DAWN. WE ALSO INTRODUCED SLIGHT CHANCES OF POPS ACROSS
OUR SOUTHERN ADIRONDACKS FOR SNOW SHOWERS.
ON SUNDAY...HIGH PRESSURE WILL BE OFFSHORE AND A SOUTHERLY FLOW WILL
CONTINUE TO BRING SOMEWHAT MILDER AIR IN ((RELATIVELY MILD AIR
CONSIDERING IT IS FULLY WINTER). TEMPERATURES LOOK TO RISE TO NEAR
40 MID HUDSON VALLEY AND LOWER LITCHFIELD COUNTY...MID OR UPPER 30S
REMAINDER OF VALLEY LOCATIONS...30-35 HIGHER TERRAIN. THE MODERATION
WILL COME WITH A PRICE...A PRETTY GOOD SOUTHERLY BREEZE AROUND 10-15
MPH AND GUSTY IN SOME PLACES...WHICH WILL MAKE IT FEEL CHILLIER
DESPITE BRINGING THE MODERATING TEMPERATURES.
ALSO...AS A WEAK CLIPPER TYPE LOW APPROACHES FROM THE GREAT
LAKES...CLOUDS WILL LIKELY INCREASE DURING THE AFTERNOON (AFTER
DECREASING A BIT IN THE MORNING). THIS SYSTEM LOOKS TO HAVE A BIT
MORE MOISTURE TO WORK WITH AND COULD PRODUCE A PERIOD OF SNOW
SHOWERS OR EVEN STEADY LIGHT SNOW ACROSS THE ADIRONDACK PARK BY LATE
IN THE DAY. BY EVENING...OTHER HIGH TERRAIN AREAS MIGHT GET IN ON
THE ACT. VALLEY LOCATIONS LOOK TO HAVE NOTHING MORE THAN SCATTERED
SNOW SHOWERS (MAYBE MIXED WITH A LITTLE RAIN IN THE MID HUDSON
VALLEY).
SNOW ACCUMULATIONS IN THE ORDER OF 1-4 INCHES ARE POSSIBLE (BUT NOT
CERTAIN) ACROSS PORTIONS OF THE ADIRONDACKS...LOCALLY OVER THE
SOUTHERN GREENS AND EVEN PERHAPS THE CATSKILLS. MOST VALLEY
LOCATIONS LOOK TO SEE A COATING UP TO LOCALLY AN INCH AT MOST...WITH
PROBABLY NOTHING ACROSS THE MID HUDSON VALLEY AND LITCHFIELD COUNTY.
TEMPERATURES SUNDAY NIGHT WILL ACTUALLY BE ABOVE NORMAL ONCE
AGAIN...BOTTOMING IN THE 20S TO AROUND 30.
MONDAY...THIS SYSTEM PUSHES TO OUR EAST. IN ITS WAKE...THE AIR
REALLY WILL NOT BE ANY COLDER. ANY LINGERING SNOW SHOWERS WILL END
BY MIDDAY MONDAY WITH LITTLE OR NO ADDITIONAL ACCUMULATION. SOME
BREAKS OF SUNSHINE WILL FOLLOW ALONG WITH A GUSTY BREEZE OUT OF THE
WEST. HIGH TEMPERATURES LOOK SIMILAR TO SUNDAY.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
COMING SOON.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
MAINLY DRY CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS OR
FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
POSSIBLE ON THE LAKES...RIVERS...AND STREAMS TONIGHT.
HOWEVER...TEMPERATURES LOOK TO RISE ABOVE FREEZING SUNDAY THROUGH
TUESDAY PREVENTING ANY MORE ICE FROM FORMING.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...
AVIATION...GJM
HYDROLOGY...HWJIV/SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
345 AM EST SAT DEC 24 2011
.SYNOPSIS...
A WEAK DISTURBANCE WILL MOVE TO OUR EAST AND A SECONDARY SURFACE
COLD FRONT WILL SLIDE TO OUR SOUTH. CANADIAN HIGH PRESSURE WILL
BRIEFLY BUILD TODAY BRINGING SUNSHINE BUT SEASONABLY COLD
TEMPERATURES. THIS HIGH WILL SLIDE TO OUR EAST LATE TONIGHT INTO
SUNDAY. A CLIPPER TYPE STORM WILL BRING A TOUCH OF SNOW TO MAINLY
THE HIGHER TERRAIN LATE SUNDAY INTO SUNDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 330 AM...NO RADAR DETECTS ANY SNOW SHOWER OR EVEN FLURRY
ACTIVITY. ASIDE FROM THE HRRR...NO MODEL GIVES ANY PART OF OUR
REGION ANY MEASURABLE QPF. THE HRRR DOES PRODUCE VERY SMALL AREAS OF
DBZ VALUES OF 25 OR EVEN HIGHER...IMPLYING MEASURING SNOW COULD TAKE
PLACE THROUGH EARLY MORNING. HOWEVER...THESE "BLIPS" LOOKED REALLY
SUSPECT. BASED ON CURRENT OBS WHICH INDICATED NO SNOW (EVEN AT
BTV)...DECIDED TO REMOVE ANY MENTION OF EVEN FLURRIES.
HIGH CLOUDS...ASSOCIATED WITH A WEAK UPPER TROUGH WHICH APPEARS
ESPECIALLY MOISTURE STARVED...WERE WORKING ACROSS THE REGION. THESE
SHOULD BE OFF TO OUR EAST SHORTLY SUNRISE. THERE ARE STILL SOME
LOWER LEVEL STRATUS CUMULUS CLOUDS...COMING OFF BOTH LAKE ONTARIO
AND LAKE CHAMPLAIN ARE VERY SHALLOW AND EVEN WITH THE HIGH CLOUDS
MOVING OVER THEM...THEY APPEAR TO BE TOO SHALLOW TO DEVELOP
SNOW.
THERE WAS ALSO A WIND SHIFT LINE OR VERY WEAK REINFORCING COLD FRONT
WORKING DOWN THE HUDSON VALLEY...JUST TO THE NORTH OF ALBANY. THIS
FRONT WILL CONTINUE TO SLIDE SOUTH AGAIN WITH NO REAL SENSIBLE
WEATHER ASSOCIATED WITH IT. THIS WILL CONTINUE MOVING
SOUTHWARD.
SO...THROUGH SUNRISE...LOOK FOR VARYING AMOUNT OF
CLOUDINESS...NOTHING MORE THAN A STRAY FLURRY...OTHERWISE DRY BUT
CHILLY. TEMPERATURES WILL BOTTOM OUT AROUND 20 LOCALLY IN THE
CAPITAL REGION...LOWER 20S SOUTH AND TEENS MOST OTHER PLACES. A
NORTHWEST WIND WILL WILL TURN MORE NORTHERLY AROUND 10 MPH ADDING A
BIT TO THE CHILL.
AFTER DAY BREAK...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE
NORTH AND SHOULD BRING INCREASING AMOUNTS OF SUNSHINE. EVEN
SO...TEMPERATURES LOOK TO REMAIN COLDER THAN NORMAL TODAY...ONLY
TOPPING OUT 30-35 MID HUDSON VALLEY AND LOWER LITCHFIELD
COUNTY...UPPER 20S GREATER CAPITAL DISTRICT...LOWER TO MID 20S MOST
OTHER PLACES. IT WILL BE A DRY DAY TO FINISH UP ALL THE PREPARATIONS
FOR THE HOLIDAY FESTIVITIES.
WENT WITH A MET/MAV BLEND AS USUAL WITH SOME MINOR TWEAKING.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
THE LOW LEVEL RIDGING WILL BE EXITING TOMORROW NIGHT AND WEAK WARM
ADVECTION WILL BEGIN...WITH LIGHT SOUTH WINDS ALSO DEVELOPING. LOWS
IN THE TEENS TO AROUND 20. ANOTHER NORTHERN STREAM UPPER IMPULSE
WILL APPROACH CHRISTMAS DAY WITH SOME INCREASING HIGH CLOUDS. SOUTH
WINDS WILL INCREASE...AND HIGHS SHOULD BE IN THE LOWER 30S TO AROUND
40.
SOME MIXED SIGNALS IN GUIDANCE AS TO HOW MUCH MOISTURE WILL BE
ASSOCIATED WITH THE SYSTEM TIMED FOR CHRISTMAS NIGHT INTO MONDAY. AT
THE MOST...SOME MOISTURE OFF THE GREAT LAKES COULD RESULT IN SOME
DUSTINGS TO AROUND AN INCH IN SOME PLACES...ESPECIALLY IN THE
WESTERN MOHAWK VALLEY...SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA
REGION TO THE SOUTHERN GREEN MOUNTAINS. LOWS CHRISTMAS NIGHT IN THE
20S TO AROUND 30. THE SYSTEM EXITS THROUGH THE DAY MONDAY AND SOME
BOUNDARY LAYER COOLING TAKES PLACE IN THE MORNING... THEN WARM
ADVECTION BEGINS LATER IN THE DAY AHEAD OF THE NEXT SYSTEM...TIMED
FOR THE MONDAY NIGHT INTO TUESDAY TIME FRAME. HIGHS IN THE 30S TO
AROUND 40...EXCEPT SOME HIGHS AROUND 30 IN THE SOUTHERN ADIRONDACKS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOS GUIDANCE. THE PERIOD WILL BE MAINLY DRY...BUT A FAST-MOVING
SYSTEM WILL BRING A DECENT SHOT OF A SHOWERY MIX OF WEATHER MAINLY
FOR THE LATTER PART OF TUESDAY...PERHAPS AS MUCH AS A HALF INCH QPFS
FOR THE REGION...NOTHING MAJOR...AND ANY SNOW ACCUMULATIONS WILL BE
LIMITED...ESPECIALLY ACROSS THE SOUTH AND IN THE VALLEYS WHERE
TEMPERATURES WILL BE ABOVE FREEZING MOST OF THE TIME. THE
UNCERTAINTY WITH TIMING...DEVELOPMENT AND TRACK OF A LOW OFF THE
MID-ATLANTIC COAST TOWARD THE END OF THE WEEK WARRANTS AT LEAST
ANOTHER POP CAT OF CHC THU NGT...BUT THIS COULD EASILY BECOME SLGT
CHC OR LESS OVER THE NEXT FEW MODEL RUNS.
TEMPERATURES ARE EXPECTED TO REMAIN SEVERAL DEGREES ABOVE NORMAL
THROUGH THE END OF THE YEAR...WITH DAILY HIGHS MAINLY FROM THE UPPER
20S TO LOWER 40S. OVERNIGHT LOWS OF TEENS AND 20S WILL BE MOST
COMMON...WITH READINGS IN THE SINGLE DIGITS ACROSS HIGH POINTS OF
THE ADIRONDACKS AND GREENS.
&&
.AVIATION /08Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
PLEASE SEE /PNSALY/ FOR RAIN AND SNOWFALL TOTALS PAST 24 HOURS.
MAINLY DRY AND COLD CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS
OR FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
LIKELY ON THE LAKES...RIVERS...AND STREAMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV
NEAR TERM...HWJIV
SHORT TERM...HWJIV
LONG TERM...GJM
AVIATION...
HYDROLOGY...SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
100 AM EST SAT DEC 24 2011
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW FLURRIES TO THE AREA THIS EVENING.
HIGH PRESSURE WILL BUILD IN FROM SOUTH CENTRAL QUEBEC TONIGHT INTO
CHRISTMAS EVE WITH SEASONABLY COLD AND DRY WEATHER. THE ARCTIC HIGH
WILL SHIFT EASTWARD ON CHRISTMAS...AS A STRONG UPPER LEVEL
DISTURBANCE WILL BRING A CHANCE OF SNOW SHOWERS AND FLURRIES DURING
THE EVENING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 AM...CLOUDS (MAINLY OF THE HIGH VARIETY) CONTINUE TO
SLOWLY WORK INTO OUR REGION. LOWER CLOUDS...CONTINUE TO HANG ACROSS
THE CATSKILLS...SOUTHERN GREENS AND NORTHERN BERKSHIRES. THESE ARE
LAKE EFFECT CLOUDS...DOWN WIND OF ONTARIO BUT THE INVERSION IS TOO
LOW FOR ANY SNOW TO FALL OUT OF THEM (OTHER THAN FLURRIES).
HIGH CLOUDS MOVING INTO THE REGION MIGHT SEEDER FEED THESE CLOUDS
AND BRING A LITTLE MORE IN THE WAY OF FLURRIES (AS WELL AS A
NORTHERLY WIND FLOW) OFF LAKE CHAMPLAIN. HOWEVER...MOISTURE IS
EXTREMELY LIMITED AND THUS FAR...NO RETURNS ON THE RADARS. SO WILL
KEEP FLURRIES IN BUT NO MORE.
REPOPULATED THE HOURLY GRIDS WHICH LOOKED PRETTY MUCH ON TRACK
COMPARED TO THE PREVIOUS FORECAST. DECIDED NOT TO RERUN THE ACTUAL
ZONES AS THE WORDING WILL CHANGE LITTLE IF AT ALL.
OTHERWISE NO CHANGES TO THE OVERNIGHT PERIODS. DESPITE THE
CLOUDS...TEMPERATURES WILL SLOWLY DROP...BOTTOMING OUT AROUND 20
LOCALLY IN THE TRI-CITY AREA...20S FURTHER SOUTH IN THE MID HUDSON
VALLEY AND LOWER LITCHFIELD...TEENS MOST OTHER PLACES.
*********PREVIOUS NEAR TERM FORECAST*******
AS OF 945 PM EST...CLOUDS ARE FINALLY SHOWING SIGNS OF BREAKING
UP IN VALLEY REGIONS...WHILE CLOUDS CONTINUE TO HANG ON ACROSS
HIGHER ELEVATIONS WITHIN THE CATSKILLS...WESTERN
ADIRONDACKS...SOUTHERN GREENS AND BERKSHIRES. SOME FLURRIES WILL
REMAIN POSSIBLE FROM THESE CLOUDS OVER THE NEXT FEW HOURS.
AS CLOUDS BEGIN TO BREAK...TEMPERATURES ARE ALSO STARTING TO
FALL...AND HAVE NOT TOUCHED OVERNIGHT MINS FROM CURRENT
PROJECTIONS...ESP GIVEN THE EXPECTATION FOR CONTINUED COLD
ADVECTION FROM THE NORTH.
HIGH/MID LEVEL CLOUDS WILL INCREASE AFTER MIDNIGHT FROM W TO E
AHEAD OF APPROACHING GREAT LAKES SHORTWAVE. THIS MAY INITIATE
ADDITIONAL SNOW FLURRIES OR LIGHT SNOW SHOWERS ACROSS PORTIONS OF
THE CATSKILLS AND ADIRONDACKS LATER TONIGHT AS SEEDER/FEEDER
MECHANISM POTENTIALLY DEVELOPS BETWEEN THICKENING MID LEVEL
CLOUDS...AND LOWER STRATOCU BELOW. IN ADDITION...SOME SNOW
FLURRIES WILL BE POSSIBLE FROM VEERING LOW LEVEL NNE FLOW ACROSS
THE UPPER HUDSON RIVER VALLEY CROSSING LAKE CHAMPLAIN...AND HAVE
KEPT MENTION OF FLURRIES IN THIS REGION AND INTO SW VT OVERNIGHT.
OTHERWISE...SOME ADJUSTMENTS TO WINDS...WHICH HAVE REMAINED BRISK
WITHIN THE MOHAWK RIVER VALLEY/CAPITAL REGION AND NORTHERN
BERKSHIRES...AND TO HOURLY TEMPS/DEWPOINTS ACCORDING TO RECENT OBS.
PREVIOUS DISCUSSION FOLLOWS...
AS OF 7 PM EST...CLOUDS ARE HANGING TOUGH...WITH SOME SCATTERED
FLURRIES CONTINUING ACROSS PORTIONS OF THE MOHAWK VALLEY AND
CAPITAL REGION. MODELS SEEM TO BE CLEARING THINGS OUT TOO
FAST...ALTHOUGH THE LATEST RUC13 DOES SEEM TO CAPTURE CURRENT SKY
COVER BEST. WILL KEEP CLOUDS AROUND LONGER THROUGH THIS
EVENING...WITH GRADUAL CLEARING THEN INDICATED AROUND AND AFTER
MIDNIGHT. AS WINDS SHIFT INTO THE NORTHWEST/NORTH...SOME
ADDITIONAL FLURRIES MAY DEVELOP DOWNWIND OF LAKE CHAMPLAIN ACROSS
THE UPPER HUDSON RIVER VALLEY...AND PERHAPS INTO THE LAKE
GEORGE/SARATOGA REGION. WILL REASSESS WITH SUBSEQUENT UPDATE FOR
POSSIBLE MENTION OVERNIGHT. IN ADDITION...WE MAY NEED TO RAISE
OVERNIGHT MINS REGIONWIDE...SHOULD CLOUDS PERSIST LONGER.
AGAIN...WILL REASSESS WITH NEXT UPDATE...AS CURRENT TEMPS WERE
ALREADY RUNNING 2-4 DEGREES ABOVE BOTH MAV/MET/LAV MOS.
SO...FOR NOW...MAINLY UPDATED SKY GRIDS TO INDICATE MORE CLOUDS
OVER THE NEXT 2-4 HOURS...AND BOOST TEMPS AS WELL THROUGH THIS
EVENING...WITH A MORE RAPID DROP IN TEMPS/DEWPOINTS INDICATED
AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS...
THE COLD FRONT WILL TRACK SOUTH OF THE REGION TONIGHT...WITH A FEW
FLURRIES POSSIBLE THROUGH THIS EVENING. THE CLOUDS WILL BREAK UP
THIS EVENING ONCE THE LOW LEVEL RIDGING BUILDS IN. WINDS WILL
GRADUALLY DIMINISH AS WELL. SOME QUESTION AS TO HOW MUCH DRY AIR CAN
SURGE SOUTH WITH ANOTHER UPPER IMPULSE APPROACHING FROM THE GREAT
LAKES...BUT BASED ON UPSTREAM CONDITIONS...TEMPERATURES SHOULD FALL
TO AROUND GUIDANCE LEVELS. TEMPERATURES SHOULD FALL TO THE HIGHER
END OF GUIDANCE...THOUGH. LOWS IN THE TEENS TO LOWER 20S...SOME
SINGLE NUMBERS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
CHAOTIC BROAD CYCLONIC UPPER FLOW WILL DOMINATE THROUGH THE PERIOD.
QUICK MOVING NORTHERN STREAM UPPER IMPULSES WILL TRACK NEAR OR
THROUGH THE REGION. FIRST...TOMORROW INTO TOMORROW EVENING...THE
SYSTEM ENTERING THE GREAT LAKES NOW WILL PROVIDE SOME MID AND HIGH
CLOUDS OVER THE REGION. WITH THE SURFACE HIGH CLOSE IN PROXIMITY...
WINDS WILL BE LIGHT. WITH LIMITED MIXING...TEMPERATURES MAY ONLY
REACH THE LOWER END OF GUIDANCE. HIGHS IN THE 20S TO LOWER 30S.
THE LOW LEVEL RIDGING WILL BE EXITING TOMORROW NIGHT AND WEAK WARM
ADVECTION WILL BEGIN...WITH LIGHT SOUTH WINDS ALSO DEVELOPING.
LOWS IN THE TEENS TO AROUND 20. ANOTHER NORTHERN STREAM UPPER
IMPULSE WILL APPROACH CHRISTMAS DAY WITH SOME INCREASING HIGH
CLOUDS. SOUTH WINDS WILL INCREASE...AND HIGHS SHOULD BE IN THE
LOWER 30S TO AROUND 40.
SOME MIXED SIGNALS IN GUIDANCE AS TO HOW MUCH MOISTURE WILL BE
ASSOCIATED WITH THE SYSTEM TIMED FOR CHRISTMAS NIGHT INTO MONDAY. AT
THE MOST...SOME MOISTURE OFF THE GREAT LAKES COULD RESULT IN SOME
DUSTINGS TO AROUND AN INCH IN SOME PLACES...ESPECIALLY IN THE
WESTERN MOHAWK VALLEY...SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA
REGION TO THE SOUTHERN GREEN MOUNTAINS. LOWS CHRISTMAS NIGHT IN THE
20S TO AROUND 30. THE SYSTEM EXITS THROUGH THE DAY MONDAY AND SOME
BOUNDARY LAYER COOLING TAKES PLACE IN THE MORNING... THEN WARM
ADVECTION BEGINS LATER IN THE DAY AHEAD OF THE NEXT SYSTEM...TIMED
FOR THE MONDAY NIGHT INTO TUESDAY TIME FRAME. HIGHS IN THE 30S TO
AROUND 40...EXCEPT SOME HIGHS AROUND 30 IN THE SOUTHERN ADIRONDACKS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOS GUIDANCE. THE PERIOD WILL BE MAINLY DRY...BUT A FAST-MOVING
SYSTEM WILL BRING A DECENT SHOT OF A SHOWERY MIX OF WEATHER MAINLY
FOR THE LATTER PART OF TUESDAY...PERHAPS AS MUCH AS A HALF INCH QPFS
FOR THE REGION...NOTHING MAJOR...AND ANY SNOW ACCUMULATIONS WILL BE
LIMITED...ESPECIALLY ACROSS THE SOUTH AND IN THE VALLEYS WHERE
TEMPERATURES WILL BE ABOVE FREEZING MOST OF THE TIME. THE
UNCERTAINTY WITH TIMING...DEVELOPMENT AND TRACK OF A LOW OFF THE
MID-ATLANTIC COAST TOWARD THE END OF THE WEEK WARRANTS AT LEAST
ANOTHER POP CAT OF CHC THU NGT...BUT THIS COULD EASILY BECOME SLGT
CHC OR LESS OVER THE NEXT FEW MODEL RUNS.
TEMPERATURES ARE EXPECTED TO REMAIN SEVERAL DEGREES ABOVE NORMAL
THROUGH THE END OF THE YEAR...WITH DAILY HIGHS MAINLY FROM THE UPPER
20S TO LOWER 40S. OVERNIGHT LOWS OF TEENS AND 20S WILL BE MOST
COMMON...WITH READINGS IN THE SINGLE DIGITS ACROSS HIGH POINTS OF
THE ADIRONDACKS AND GREENS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH THE END OF THE TAF PERIOD (06Z
SUNDAY) AT THE KGFL/KALB/KPOU TAF SITES. SCT-BKN STRATOCU EARLY THIS
MORNING WILL GRADUALLY BE REDUCED TO FEW/SCT BY SUNRISE...WITH BKN
MID/HI CLOUDS SPREADING IN OVERHEAD THEREAFTER. STRATOCU THIS
MORNING WILL GENERALLY BE VFR...BUT WILL OCCASIONALLY BY MVFR AT
KGFL. BY AROUND 19Z EVEN ALL CLOUDS ARE EXPECTED TO MOVE OUT...WITH
P6SM SKC CONDITIONS THROUGH 06Z SUNDAY.
SURFACE WINDS WILL BE NORTH TO NORTHWEST THIS MORNING AT 5 TO 10
KTS...AND REMAIN AT THOSE SPEEDS ON SATURDAY BUT FROM THE NORTH TO
NORTHEAST. SATURDAY NIGHT WILL FEATURE CALM TO VERY LIGHT WIND
CONDITIONS.
OUTLOOK...
LATE SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
PLEASE SEE /PNSALY/ FOR RAIN AND SNOWFALL TOTALS PAST 24 HOURS.
MAINLY DRY AND COLD CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS
OR FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
LIKELY ON THE LAKES...RIVERS...AND STREAMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/NAS
NEAR TERM...HWJIV/KL
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...GJM
HYDROLOGY...SND
AREA FORECAST DISCUSSION
NWS ALBANY NY
1240 AM EST SAT DEC 24 2011
.SYNOPSIS...
A COLD FRONT WILL BRING SNOW FLURRIES TO THE AREA THIS EVENING.
HIGH PRESSURE WILL BUILD IN FROM SOUTH CENTRAL QUEBEC TONIGHT INTO
CHRISTMAS EVE WITH SEASONABLY COLD AND DRY WEATHER. THE ARCTIC HIGH
WILL SHIFT EASTWARD ON CHRISTMAS...AS A STRONG UPPER LEVEL
DISTURBANCE WILL BRING A CHANCE OF SNOW SHOWERS AND FLURRIES DURING
THE EVENING.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
AS OF 1230 AM...CLOUDS (MAINLY OF THE HIGH VARIETY) CONTINUE TO
SLOWLY WORK INTO OUR REGION. LOWER CLOUDS...CONTINUE TO HANG ACROSS
THE CATSKILLS...SOUTHERN GREENS AND NORTHERN BERKSHIRES. THESE ARE
LAKE EFFECT CLOUDS...DOWN WIND OF ONTARIO BUT THE INVERSION IS TOO
LOW FOR ANY SNOW TO FALL OUT OF THEM (OTHER THAN FLURRIES).
HIGH CLOUDS MOVING INTO THE REGION MIGHT SEEDER FEED THESE CLOUDS
AND BRING A LITTLE MORE IN THE WAY OF FLURRIES (AS WELL AS A
NORTHERLY WIND FLOW) OFF LAKE CHAMPLAIN. HOWEVER...MOISTURE IS
EXTREMELY LIMITED AND THUS FAR...NO RETURNS ON THE RADARS. SO WILL
KEEP FLURRIES IN BUT NO MORE.
REPOPULATED THE HOURLY GRIDS WHICH LOOKED PRETTY MUCH ON TRACK
COMPARED TO THE PREVIOUS FORECAST. DECIDED NOT TO RERUN THE ACTUAL
ZONES AS THE WORDING WILL CHANGE LITTLE IF AT ALL.
OTHERWISE NO CHANGES TO THE OVERNIGHT PERIODS. DESPITE THE
CLOUDS...TEMPERATURES WILL SLOWLY DROP...BOTTOMING OUT AROUND 20
LOCALLY IN THE TRI-CITY AREA...20S FURTHER SOUTH IN THE MID HUDSON
VALLEY AND LOWER LITCHFIELD...TEENS MOST OTHER PLACES.
*********PREVIOUS NEAR TERM FORECAST*******
AS OF 945 PM EST...CLOUDS ARE FINALLY SHOWING SIGNS OF BREAKING
UP IN VALLEY REGIONS...WHILE CLOUDS CONTINUE TO HANG ON ACROSS
HIGHER ELEVATIONS WITHIN THE CATSKILLS...WESTERN
ADIRONDACKS...SOUTHERN GREENS AND BERKSHIRES. SOME FLURRIES WILL
REMAIN POSSIBLE FROM THESE CLOUDS OVER THE NEXT FEW HOURS.
AS CLOUDS BEGIN TO BREAK...TEMPERATURES ARE ALSO STARTING TO
FALL...AND HAVE NOT TOUCHED OVERNIGHT MINS FROM CURRENT
PROJECTIONS...ESP GIVEN THE EXPECTATION FOR CONTINUED COLD
ADVECTION FROM THE NORTH.
HIGH/MID LEVEL CLOUDS WILL INCREASE AFTER MIDNIGHT FROM W TO E
AHEAD OF APPROACHING GREAT LAKES SHORTWAVE. THIS MAY INITIATE
ADDITIONAL SNOW FLURRIES OR LIGHT SNOW SHOWERS ACROSS PORTIONS OF
THE CATSKILLS AND ADIRONDACKS LATER TONIGHT AS SEEDER/FEEDER
MECHANISM POTENTIALLY DEVELOPS BETWEEN THICKENING MID LEVEL
CLOUDS...AND LOWER STRATOCU BELOW. IN ADDITION...SOME SNOW
FLURRIES WILL BE POSSIBLE FROM VEERING LOW LEVEL NNE FLOW ACROSS
THE UPPER HUDSON RIVER VALLEY CROSSING LAKE CHAMPLAIN...AND HAVE
KEPT MENTION OF FLURRIES IN THIS REGION AND INTO SW VT OVERNIGHT.
OTHERWISE...SOME ADJUSTMENTS TO WINDS...WHICH HAVE REMAINED BRISK
WITHIN THE MOHAWK RIVER VALLEY/CAPITAL REGION AND NORTHERN
BERKSHIRES...AND TO HOURLY TEMPS/DEWPOINTS ACCORDING TO RECENT OBS.
PREVIOUS DISCUSSION FOLLOWS...
AS OF 7 PM EST...CLOUDS ARE HANGING TOUGH...WITH SOME SCATTERED
FLURRIES CONTINUING ACROSS PORTIONS OF THE MOHAWK VALLEY AND
CAPITAL REGION. MODELS SEEM TO BE CLEARING THINGS OUT TOO
FAST...ALTHOUGH THE LATEST RUC13 DOES SEEM TO CAPTURE CURRENT SKY
COVER BEST. WILL KEEP CLOUDS AROUND LONGER THROUGH THIS
EVENING...WITH GRADUAL CLEARING THEN INDICATED AROUND AND AFTER
MIDNIGHT. AS WINDS SHIFT INTO THE NORTHWEST/NORTH...SOME
ADDITIONAL FLURRIES MAY DEVELOP DOWNWIND OF LAKE CHAMPLAIN ACROSS
THE UPPER HUDSON RIVER VALLEY...AND PERHAPS INTO THE LAKE
GEORGE/SARATOGA REGION. WILL REASSESS WITH SUBSEQUENT UPDATE FOR
POSSIBLE MENTION OVERNIGHT. IN ADDITION...WE MAY NEED TO RAISE
OVERNIGHT MINS REGIONWIDE...SHOULD CLOUDS PERSIST LONGER.
AGAIN...WILL REASSESS WITH NEXT UPDATE...AS CURRENT TEMPS WERE
ALREADY RUNNING 2-4 DEGREES ABOVE BOTH MAV/MET/LAV MOS.
SO...FOR NOW...MAINLY UPDATED SKY GRIDS TO INDICATE MORE CLOUDS
OVER THE NEXT 2-4 HOURS...AND BOOST TEMPS AS WELL THROUGH THIS
EVENING...WITH A MORE RAPID DROP IN TEMPS/DEWPOINTS INDICATED
AFTER MIDNIGHT.
PREVIOUS DISCUSSION FOLLOWS...
THE COLD FRONT WILL TRACK SOUTH OF THE REGION TONIGHT...WITH A FEW
FLURRIES POSSIBLE THROUGH THIS EVENING. THE CLOUDS WILL BREAK UP
THIS EVENING ONCE THE LOW LEVEL RIDGING BUILDS IN. WINDS WILL
GRADUALLY DIMINISH AS WELL. SOME QUESTION AS TO HOW MUCH DRY AIR CAN
SURGE SOUTH WITH ANOTHER UPPER IMPULSE APPROACHING FROM THE GREAT
LAKES...BUT BASED ON UPSTREAM CONDITIONS...TEMPERATURES SHOULD FALL
TO AROUND GUIDANCE LEVELS. TEMPERATURES SHOULD FALL TO THE HIGHER
END OF GUIDANCE...THOUGH. LOWS IN THE TEENS TO LOWER 20S...SOME
SINGLE NUMBERS IN THE SOUTHERN ADIRONDACKS.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
CHAOTIC BROAD CYCLONIC UPPER FLOW WILL DOMINATE THROUGH THE PERIOD.
QUICK MOVING NORTHERN STREAM UPPER IMPULSES WILL TRACK NEAR OR
THROUGH THE REGION. FIRST...TOMORROW INTO TOMORROW EVENING...THE
SYSTEM ENTERING THE GREAT LAKES NOW WILL PROVIDE SOME MID AND HIGH
CLOUDS OVER THE REGION. WITH THE SURFACE HIGH CLOSE IN PROXIMITY...
WINDS WILL BE LIGHT. WITH LIMITED MIXING...TEMPERATURES MAY ONLY
REACH THE LOWER END OF GUIDANCE. HIGHS IN THE 20S TO LOWER 30S.
THE LOW LEVEL RIDGING WILL BE EXITING TOMORROW NIGHT AND WEAK WARM
ADVECTION WILL BEGIN...WITH LIGHT SOUTH WINDS ALSO DEVELOPING.
LOWS IN THE TEENS TO AROUND 20. ANOTHER NORTHERN STREAM UPPER
IMPULSE WILL APPROACH CHRISTMAS DAY WITH SOME INCREASING HIGH
CLOUDS. SOUTH WINDS WILL INCREASE...AND HIGHS SHOULD BE IN THE
LOWER 30S TO AROUND 40.
SOME MIXED SIGNALS IN GUIDANCE AS TO HOW MUCH MOISTURE WILL BE
ASSOCIATED WITH THE SYSTEM TIMED FOR CHRISTMAS NIGHT INTO MONDAY. AT
THE MOST...SOME MOISTURE OFF THE GREAT LAKES COULD RESULT IN SOME
DUSTINGS TO AROUND AN INCH IN SOME PLACES...ESPECIALLY IN THE
WESTERN MOHAWK VALLEY...SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA
REGION TO THE SOUTHERN GREEN MOUNTAINS. LOWS CHRISTMAS NIGHT IN THE
20S TO AROUND 30. THE SYSTEM EXITS THROUGH THE DAY MONDAY AND SOME
BOUNDARY LAYER COOLING TAKES PLACE IN THE MORNING... THEN WARM
ADVECTION BEGINS LATER IN THE DAY AHEAD OF THE NEXT SYSTEM...TIMED
FOR THE MONDAY NIGHT INTO TUESDAY TIME FRAME. HIGHS IN THE 30S TO
AROUND 40...EXCEPT SOME HIGHS AROUND 30 IN THE SOUTHERN ADIRONDACKS.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MOS GUIDANCE. THE PERIOD WILL BE MAINLY DRY...BUT A FAST-MOVING
SYSTEM WILL BRING A DECENT SHOT OF A SHOWERY MIX OF WEATHER MAINLY
FOR THE LATTER PART OF TUESDAY...PERHAPS AS MUCH AS A HALF INCH QPFS
FOR THE REGION...NOTHING MAJOR...AND ANY SNOW ACCUMULATIONS WILL BE
LIMITED...ESPECIALLY ACROSS THE SOUTH AND IN THE VALLEYS WHERE
TEMPERATURES WILL BE ABOVE FREEZING MOST OF THE TIME. THE
UNCERTAINTY WITH TIMING...DEVELOPMENT AND TRACK OF A LOW OFF THE
MID-ATLANTIC COAST TOWARD THE END OF THE WEEK WARRANTS AT LEAST
ANOTHER POP CAT OF CHC THU NGT...BUT THIS COULD EASILY BECOME SLGT
CHC OR LESS OVER THE NEXT FEW MODEL RUNS.
TEMPERATURES ARE EXPECTED TO REMAIN SEVERAL DEGREES ABOVE NORMAL
THROUGH THE END OF THE YEAR...WITH DAILY HIGHS MAINLY FROM THE UPPER
20S TO LOWER 40S. OVERNIGHT LOWS OF TEENS AND 20S WILL BE MOST
COMMON...WITH READINGS IN THE SINGLE DIGITS ACROSS HIGH POINTS OF
THE ADIRONDACKS AND GREENS.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
EXPECT MAINLY VFR CONDITIONS THROUGH AT LEAST 00Z/SUNDAY. VFR CIGS
WITH BASES OF 3500-5000 FT AGL WILL PERSIST THROUGH AT LEAST
06Z/SAT...WITH GRADUAL DECREASE IN LOWER LEVEL CLOUDS EXPECTED
THEREAFTER. THERE IS A SLIGHT CHC FOR MVFR CIGS AT KGFL AND KALB
LATER THIS EVENING BEFORE DRIER AIR ALLOWS CIGS TO BREAK.
SOME FLURRIES WILL BE POSSIBLE THROUGH MIDNIGHT AT KGFL AND
KALB.
EXPECT NORTHWEST TO NORTH WINDS AT 5-10 KT TONIGHT...ALTHOUGH
10-15 KT WITH SOME GUSTS UP TO 20 KT POSSIBLE AT KALB THROUGH THIS
EVENING. WINDS WILL BECOME MAINLY NORTH ON SATURDAY AT 5-10 KT.
OUTLOOK...
SAT NIGHT...VFR...NO SIG WX.
SUN-SUN NIGHT...VFR/MVFR...SLIGHT CHC/CHC -SHSN.
MON...VFR...NO SIG WX. BLUSTERY.
TUE-WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED OVER THE NEXT SEVERAL DAYS.
PLEASE SEE /PNSALY/ FOR RAIN AND SNOWFALL TOTALS PAST 24 HOURS.
MAINLY DRY AND COLD CONDITIONS...EXCEPT FOR SOME LIGHT SNOW SHOWERS
OR FLURRIES ARE EXPECTED THROUGH MONDAY. SOME ICE FORMATION IS
LIKELY ON THE LAKES...RIVERS...AND STREAMS.
FOR DETAILS ON SPECIFIC AREA RIVERS AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEBSITE.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.
&&
$$
SYNOPSIS...HWJIV/NAS
NEAR TERM...HWJIV/KL
SHORT TERM...NAS
LONG TERM...ELH
AVIATION...KL
HYDROLOGY...SND
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1147 PM CST FRI DEC 23 2011
.AVIATION...
WEST TO NORTHWEST FLOW WITH UPPER RIDGING WILL BRING QUIET WEATHER
TO THE REGION THE NEXT FEW DAYS. SKIES WILL BE CLEAR TO MOSTLY
CLEAR WITH SOME PASSING HIGH CLOUDS PERIODICALLY. LIGHT WEST TO
SOUTHWEST WINDS CAN BE EXPECTED OF 5-10 MPH WITH VISIBILITIES AOA
7 MILES...RESULTING IN VFR CONDITIONS. ..NICHOLS..
&&
.PREV DISCUSSION... /ISSUED 312 PM CST FRI DEC 23 2011/
SYNOPSIS...
A VIGOROUS CLIPPER SYSTEM WAS SEEN ON WATER VAPOR IMAGERY
SWEEPING SOUTHEAST ACROSS MN AND WI THIS AFTERNOON. AT
18Z...ASSOCIATED SURFACE LOW PRESSURE WAS CENTERED IN SW ONTARIO
JUST NORTH OF MN WITH A TROUGH EXTENDING S-SW ACROSS MN INTO
CENTRAL NEB. AHEAD OF THIS TROUGH...WIDESPREAD LIGHT SNOW AND
BRIEF LOCALIZED MODERATE SNOW WAS FALLING ACROSS SE MN INTO MUCH
OF WI. MID AND HIGH LEVEL CLOUD COVER PRECEDING THE SYSTEM HAS
SPREAD SOUTH-SE TO COVER THE NORTHERN HALF OF THE FORECAST
AREA...WHILE STRATUS TO THE SOUTH THAT PERSISTED OVERNIGHT HAS
BEEN DRAWN NORTHWARD IN THE LOW LEVEL SW FLOW TO COVER THE FAR
SOUTHEAST PART OF THE FORECAST AREA. THE CLOUD COVER...AND
SLIGHTLY HIGHER LOW LEVEL MOISTURE LEVELS...HAVE HELD TEMPERATURES
A FEW DEGREES COOLER THAN EXPECTED TODAY WITH MANY AREAS
STRUGGLING TO REACH 32 AS OF 2 PM.
SHORT TERM...TONIGHT AND SATURDAY...
THE MAIN FOCUS IS ON THE NEAR TERM POTENTIAL FOR LIGHT SNOW. 12Z
FORECAST MODELS HAVE GENERALLY BEEN TOO WEAK WITH THE SURFACE
PRESSURE FIELDS...TOO LOW ON LOW LEVEL MOISTURE LEVELS...AND ALSO
AND A BIT TOO FAR NORTH AND TOO WEAK WITH THE UPPER FORCING SO FAR
TODAY. FOLLOWING THE LATEST RUC DEPICTION OF A LOBE OF MID LEVEL
VORTICITY ROTATING AROUND THE BASE OF THE MAIN SHORTWAVE...THE TRACK
OF UPPER LEVEL DIVERGENCE IN THE LEFT EXIT REGION OF A 100 PLUS
KT JET DIVING SOUTH OUT OF MANITOBA...THERE IS SUPPORT THAT LIFT
AND SATURATION MAY PULL FLURRIES OR EVEN LIGHT SNOW FURTHER SOUTH
AND SOUTHWEST THAN PREVIOUSLY EXPECTED. AN IMPRESSIVE AXIS OF
WIDESPREAD 4 MB PRESSURE FALLS ON MSAS SWEEPING INTO EASTERN IA
AND A MOST RECENT 5 MB BULLSEYE CENTERED NEAR VINTON...FURTHER
SUPPORTS THIS POSSIBILITY. HOWEVER...WITH CLOUD BASES STILL WELL
ABOVE 9000 FT OVER MOST OF IA AND A STRONG SW LOW LEVEL FLOW
ADVECTING DRY AIR INTO THIS FAST MOVING SYSTEM...SUFFICIENT
SATURATION WILL BE DIFFICULT OVER MOST OF THE FORECAST AREA. HAVE
ADDED A POTENTIAL FOR FLURRIES ACROSS THE NORTHEAST FOR LATE
AFTERNOON INTO EVENING...WITH LOW CHANCES FOR A DUSTING OF
ACCUMULATION ALONG AND NORTH OF THE HIGHWAY 20 CORRIDOR IN IL.
ONCE THIS SYSTEM PASSES EARLY THIS EVENING...DRIER AIR AND WEAK
SUBSIDENCE SHOULD ALLOW THE WIDESPREAD CLEARING OVER THE PLAINS TO
SPREAD EASTWARD OVER THE FORECAST AREA. HAVE KEPT LOWS IN A RANGE
FROM THE TEENS NORTH TO LOWER 20S SOUTH...BUT WILL HAVE TO WATCH
TRENDS CLOSELY AS TEMPERATURES COULD POSSIBLY PLUNGE LOWER AS WINDS
BECOME LIGHT WESTERLY LATE TONIGHT UNDER MOSTLY CLEAR SKIES.
SATURDAY...TEMPERATURES SHOULD MODERATE AS WARM ADVECTION ALOFT
COMMENCES WHILE A LARGELY DRY AIRMASS FAVORS MOSTLY SUNNY SKIES.
FORECAST SOUNDINGS DEPICT A LOW LEVEL INVERSION HOLDING STRONG WITH
GENERALLY LIGHT SW WINDS AND HAVE THUS HELD HIGHS CLOSE TO GUIDANCE
VALUES IN THE 30S OVER MOST OF THE AREA. ..SHEETS..
LONG TERM...SATURDAY NIGHT THROUGH NEXT FRIDAY...
AN OVERALL TREND OF WARMER AND LIKELY DRIER THAN NORMAL SHOULD BE
SEEN THROUGH THE END OF THE MONTH.
A COLD FRONTAL PASSAGE WILL OCCUR SATURDAY NIGHT/EARLY SUNDAY AS
ANOTHER SYSTEM PASSES WELL NORTH OF THE AREA. CONDENSATION PRESSURE
DEFICITS IN THE LOW AND MID LEVELS ARE QUITE HIGH. THUS A DRY FROPA
SHOULD BE SEEN WITH ONLY AN INCREASE IN CLOUDS. BRISK CONDITIONS
WILL BE SEEN ON SUNDAY WITH RESPECTABLE CAA BEHIND THE FRONT.
HIGH PRESSURE WILL QUICKLY MOVE THROUGH THE REGION SUNDAY NIGHT
KEEPING QUIET AND DRY CONDITIONS ACROSS THE AREA. ATTENTION THEN
TURNS TO THE STORM SYSTEM EARLY NEXT WEEK.
THE OVERALL LONGWAVE PATTERN IS DE-AMPLIFYING AND WILL ELIMINATE THE
SPLIT FLOW OVER THE WESTERN CONUS EARLY NEXT WEEK. A STRONG UPPER
LEVEL SYSTEM NEAR 40N/160W WILL MAKE LANDFALL ON THE WA/OR COAST
SUNDAY AND WILL BE THE KEY TO WHAT HAPPENS WITH THE CUT OFF LOW IN
THE SOUTHERN STREAM MONDAY INTO MONDAY NIGHT. THE OVERALL TREND WITH
THE MODELS HAS BEEN TO SLOW DOWN THE EJECTION OF THE CUT OFF LOW.
THUS THERE ARE TWO POSSIBLE OUTCOMES. THE FIRST IS A PARTIAL PHASING
WITH THE NORTHERN STREAM ENERGY WHICH WOULD PULL THE SOUTHERN CUT
OFF LOW FURTHER NORTH. THE OTHER POSSIBILITY IS A CONTINUED SLOWING
OF THE CUT OFF LOW WHICH WOULD RESULT IN NO PHASING OF THE NORTHERN
AND SOUTHERN STREAMS. IF THE SECOND SCENARIO OCCURS...THE SOUTHERN
STREAM SYSTEM WOULD PASS SOUTH OF THE AREA RESULTING IN DRY
CONDITIONS.
SINCE THE MODELS HAVE BECOME SLOWER WITH THE SOUTHERN CUT OFF
LOW...MONDAY WILL BE DRY WITH AN INCREASE IN CLOUDS THROUGH THE DAY.
PRECIPITATION MAY BE NOT FAR AWAY FROM THE SOUTHERN CWFA BY SUNSET
MONDAY.
MONDAY NIGHT ON...
RIGHT NOW THE MODEL CONSENSUS IS FOR A PARTIAL PHASING OF THE
NORTHERN AND SOUTHERN STREAMS. SUCH A SCENARIO WILL BRING A THREAT
OF PRECIPITATION TO MUCH OF THE CWFA MONDAY NIGHT. A RAIN/SNOW MIX
LOOKS TO BE THE MOST LIKELY WITH A POSSIBLE CHANGE OVER TO ALL SNOW
JUST PRIOR TO SUNRISE TUESDAY. ANY SNOWFALL WOULD BE ONE HALF INCH
OR LESS.
MODEL CONSENSUS GIVES QUIET AND DRY CONDITIONS TUESDAY/TUES NIGHT AS
HIGH PRESSURE QUICKLY MOVES THROUGH THE AREA.
BY MID WEEK A NEAR ZONAL OR VERY LOW AMPLITUDE FLOW WILL EXIST
ACROSS THE CONUS AND PACIFIC. THERE ARE DIFFERENCES BETWEEN THE
MODELS BUT THE POTENTIAL EXISTS FOR A NEAR DAILY OCCURRENCE OF
CLIPPER OR HYBRID CLIPPER SYSTEMS FROM WEDNESDAY THROUGH FRIDAY. THE
MODEL DIFFERENCES WITH TIMING AND SMOOTHING ARE CAUSING POPS TO
CANCEL EACH OTHER OUT WHICH PRODUCES A CONSENSUS FCST OF MAINLY DRY
CONDITIONS FOR WEDNESDAY THROUGH FRIDAY.
INTERNALLY...THE MODELS SHOW SOME RESPECTABLE FORCING AND A
LOWERING OF CONDENSATION PRESSURE DEFICITS WITH EACH SYSTEM. THUS
THERE MAY BE A POTENTIAL FOR PRECIPITATION WEDNESDAY THROUGH FRIDAY.
THE SMOOTHING OF FEATURES MAKES IT DIFFICULT TO ASCERTAIN WHERE
PRECIPITATION MAY OCCUR. AREAS NORTH OF HWY 30 ARE CURRENTLY
DEPICTED AS HAVING THE BETTER FORCING AND LOWER CONDENSATION
PRESSURE DEFICITS WHICH IMPLIES A BETTER CHANCE OF PRECIPITATION.
HOWEVER...ANY PRECIPITATION THAT OCCURS WILL BE LIGHT.
THE PROGNOSTIC CHARTS ARE INDICATING THE LONGWAVE PATTERN WILL BEGIN
TO RE-AMPLIFY IN EARLY JANUARY. A WEAK TO MODERATE LA NINA COMBINED
WITH A NEGATIVE PDO AND SST ANOMALIES WOULD FAVOR A LONGWAVE TROF
NEAR THE EAST COAST. ..08..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
NICHOLS
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1101 AM MST SAT DEC 24 2011
.SHORT TERM (TODAY-MONDAY)...
224 AM MST SAT DEC 24 2011
CLEAR SKIES WERE OBSERVED ACROSS THE TRI-STATE AREA EARLY THIS
MORNING. UPPER AIR ANALYSIS FROM THE RUC SHOWS THE CLOSED LOW
REMAINING OVER THE SOUTHWEST CONUS...BUT SLOWLY MOVING TO THE EAST.
NORTHWEST FLOW CONTINUES OVER THE NORTHERN AND CENTRAL CONUS FROM
THE UPPER HIGH OFF THE WEST COAST.
TODAY THROUGH CHRISTMAS DAY AN UPPER LEVEL RIDGE WILL CONTINUE OVER
THE TRI-STATE AREA. DURING THIS TIME THE CLOSED LOW THAT IS
CURRENTLY OVER THE SOUTHWEST CONUS WILL MIGRATE NORTHEAST...EDGING
INTO THE SOUTHERN PARTS OF THE AREA SUNDAY AFTERNOON THROUGH SUNDAY NIGHT.
CROSS SECTIONS AND PLAN VIEW SHOW SOME FORCING FOR LIFT AND
INSTABILITY ON SUNDAY NIGHT ASSOCIATED WITH THE CLOSED LOW.
HOWEVER THERE WILL BE LITTLE MOISTURE TO WORK WITH...AS MOST OF
THE MOISTURE ASSOCIATED WITH THE CLOSED LOW WILL BE OVER THE TEXAS
PANHANDLE.
MONDAY A SURFACE TROUGH WILL MOVE THROUGH THE AREA ACCOMPANIED BY AN
UPPER LEVEL TROUGH MOVING THROUGH THE NORTHWEST FLOW. BEHIND THE SURFACE
FEATURE NORTHWEST WINDS WILL INCREASE AS THE PRESSURE GRADIENT
TIGHTENS AND STRONGER WINDS ABOVE THE SURFACE MIX DOWN. MEANWHILE
THE UPPER LEVEL SHORT WAVE TROUGH MOVES THROUGH...BRINGING SOME
MOISTURE AND INSTABILITY WITH IT. UNFORTUNATELY THE MOISTURE WILL
BE ABOVE 500MB WITH DRY AIR FROM 500MB TO THE SURFACE...ALLOWING
ANY PRECIPITATION THAT MAY FORM TO EVAPORATE BEFORE IT REACHES THE
SURFACE. THE SHORT WAVE WILL THEN PUSH THE CLOSED LOW ON EAST AS
IT MOVES OUT OF THE AREA.
TEMPERATURE-WISE OBSERVATIONS FROM YESTERDAY SHOW THE EXCESSIVE SNOW
COVER IS HAVING A SIGNIFICANT EFFECT. AS SUCH WENT BELOW MOST
GUIDANCE FOR TEMPERATURES FOR AREAS WITH EXCESSIVE SNOW COVER. WITH
WARMING TEMPERATURES THROUGH THE PERIOD...SNOW COVER SHOULD HAVE
LESS OF AN EFFECT AS IT MELTS.
TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD AS WEST TO
NORTHWEST WINDS BRING WARMER AIR INTO THE AREA. HIGH TEMPERATURES
WILL WARM 5 TO 10 DEGREES ABOVE NORMAL BY MONDAY. LOW TEMPERATURES
WILL BE NEAR NORMAL EXCEPT FOR AREAS THAT STILL HAVE EXCESSIVE SNOW
COVER...WHICH WILL HAVE LOW TEMPERATURES 5 TO 10 DEGREES BELOW
NORMAL.
JTL
.LONG TERM (TUESDAY-FRIDAY)...
224 AM MST SAT DEC 24 2011
FOR THE PERIOD TUESDAY THROUGH FRIDAY...PROGRESSIVE PATTERN WILL BE
IN PLACE ACROSS THE CONUS WITH A SERIES OF FAST MOVING AND WEAK
SYSTEMS. THE ONLY ONE THAT APPEARS TO HAVE EVEN A SLIGHT CHANCE OF
BRINGING PRECIPITATION TO THE AREA WILL BE ON THURSDAY NIGHT...BUT
IT WOULD BE VERY LIGHT IF IT OCCURS AT ALL. DEEP WESTERLY FLOW WILL
DOMINATE AND RESULT IN LIMITED MOISTURE. THERE IS NO COLD AIR IN
SIGHT AND TEMPERATURES WILL BE ABOVE NORMAL THE ENTIRE PERIOD. /024
024
&&
.AVIATION...
1056 AM MST SAT DEC 24 2011
WEAK NORTHWEST NEAR SURFACE FLOW REMAINS IN PLACE AS DOES THE AREA
OF GENERALLY HIGHER PRESSURE OVER THE ROCKIES AND HIGH PLAINS. VFR
CONDITIONS WILL PREVAIL THROUGH THE REMAINDER OF
SATURDAY...CHRISTMAS EVE...AND CHRISTMAS DAY.
LOCKHART
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
420 AM MST SAT DEC 24 2011
.SHORT TERM (TODAY-MONDAY)...
224 AM MST SAT DEC 24 2011
CLEAR SKIES WERE OBSERVED ACROSS THE TRI-STATE AREA EARLY THIS
MORNING. UPPER AIR ANALYSIS FROM THE RUC SHOWS THE CLOSED LOW
REMAINING OVER THE SOUTHWEST CONUS...BUT SLOWLY MOVING TO THE EAST.
NORTHWEST FLOW CONTINUES OVER THE NORTHERN AND CENTRAL CONUS FROM
THE UPPER HIGH OFF THE WEST COAST.
TODAY THROUGH CHRISTMAS DAY AN UPPER LEVEL RIDGE WILL CONTINUE OVER
THE TRI-STATE AREA. DURING THIS TIME THE CLOSED LOW THAT IS
CURRENTLY OVER THE SOUTHWEST CONUS WILL MIGRATE NORTHEAST...EDGING
INTO THE SOUTHERN PARTS OF THE AREA SUNDAY AFTERNOON THROUGH SUNDAY NIGHT.
CROSS SECTIONS AND PLAN VIEW SHOW SOME FORCING FOR LIFT AND
INSTABILITY ON SUNDAY NIGHT ASSOCIATED WITH THE CLOSED LOW.
HOWEVER THERE WILL BE LITTLE MOISTURE TO WORK WITH...AS MOST OF
THE MOISTURE ASSOCIATED WITH THE CLOSED LOW WILL BE OVER THE TEXAS
PANHANDLE.
MONDAY A SURFACE TROUGH WILL MOVE THROUGH THE AREA ACCOMPANIED BY AN
UPPER LEVEL TROUGH MOVING THROUGH THE NORTHWEST FLOW. BEHIND THE SURFACE
FEATURE NORTHWEST WINDS WILL INCREASE AS THE PRESSURE GRADIENT
TIGHTENS AND STRONGER WINDS ABOVE THE SURFACE MIX DOWN. MEANWHILE
THE UPPER LEVEL SHORT WAVE TROUGH MOVES THROUGH...BRINGING SOME
MOISTURE AND INSTABILITY WITH IT. UNFORTUNATELY THE MOISTURE WILL
BE ABOVE 500MB WITH DRY AIR FROM 500MB TO THE SURFACE...ALLOWING
ANY PRECIPITATION THAT MAY FORM TO EVAPORATE BEFORE IT REACHES THE
SURFACE. THE SHORT WAVE WILL THEN PUSH THE CLOSED LOW ON EAST AS
IT MOVES OUT OF THE AREA.
TEMPERATURE-WISE OBSERVATIONS FROM YESTERDAY SHOW THE EXCESSIVE SNOW
COVER IS HAVING A SIGNIFICANT EFFECT. AS SUCH WENT BELOW MOST
GUIDANCE FOR TEMPERATURES FOR AREAS WITH EXCESSIVE SNOW COVER. WITH
WARMING TEMPERATURES THROUGH THE PERIOD...SNOW COVER SHOULD HAVE
LESS OF AN EFFECT AS IT MELTS.
TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD AS WEST TO
NORTHWEST WINDS BRING WARMER AIR INTO THE AREA. HIGH TEMPERATURES
WILL WARM 5 TO 10 DEGREES ABOVE NORMAL BY MONDAY. LOW TEMPERATURES
WILL BE NEAR NORMAL EXCEPT FOR AREAS THAT STILL HAVE EXCESSIVE SNOW
COVER...WHICH WILL HAVE LOW TEMPERATURES 5 TO 10 DEGREES BELOW
NORMAL.
JTL
.LONG TERM (TUESDAY-FRIDAY)...
224 AM MST SAT DEC 24 2011
FOR THE PERIOD TUESDAY THROUGH FRIDAY...PROGRESSIVE PATTERN WILL BE
IN PLACE ACROSS THE CONUS WITH A SERIES OF FAST MOVING AND WEAK
SYSTEMS. THE ONLY ONE THAT APPEARS TO HAVE EVEN A SLIGHT CHANCE OF
BRINGING PRECIPITATION TO THE AREA WILL BE ON THURSDAY NIGHT...BUT
IT WOULD BE VERY LIGHT IF IT OCCURS AT ALL. DEEP WESTERLY FLOW WILL
DOMINATE AND RESULT IN LIMITED MOISTURE. THERE IS NO COLD AIR IN
SIGHT AND TEMPERATURES WILL BE ABOVE NORMAL THE ENTIRE PERIOD. /024
024
&&
.AVIATION...
420 AM MST SAT DEC 24 2011
VFR CONDS EXPECTED NEXT 24 HOURS AT BOTH TERMINALS AS HIGH PRESSURE
WILL BE IN CONTROL OF THE WEATHER PATTERN.
BAS/024
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
230 AM MST SAT DEC 24 2011
.SHORT TERM (TODAY-MONDAY)...
224 AM MST SAT DEC 24 2011
CLEAR SKIES WERE OBSERVED ACROSS THE TRI-STATE AREA EARLY THIS
MORNING. UPPER AIR ANALYSIS FROM THE RUC SHOWS THE CLOSED LOW
REMAINING OVER THE SOUTHWEST CONUS...BUT SLOWLY MOVING TO THE EAST.
NORTHWEST FLOW CONTINUES OVER THE NORTHERN AND CENTRAL CONUS FROM
THE UPPER HIGH OFF THE WEST COAST.
TODAY THROUGH CHRISTMAS DAY AN UPPER LEVEL RIDGE WILL CONTINUE OVER
THE TRI-STATE AREA. DURING THIS TIME THE CLOSED LOW THAT IS
CURRENTLY OVER THE SOUTHWEST CONUS WILL MIGRATE NORTHEAST...EDGING
INTO THE SOUTHERN PARTS OF THE AREA SUNDAY AFTERNOON THROUGH SUNDAY NIGHT.
CROSS SECTIONS AND PLAN VIEW SHOW SOME FORCING FOR LIFT AND
INSTABILITY ON SUNDAY NIGHT ASSOCIATED WITH THE CLOSED LOW.
HOWEVER THERE WILL BE LITTLE MOISTURE TO WORK WITH...AS MOST OF
THE MOISTURE ASSOCIATED WITH THE CLOSED LOW WILL BE OVER THE TEXAS
PANHANDLE.
MONDAY A SURFACE TROUGH WILL MOVE THROUGH THE AREA ACCOMPANIED BY AN
UPPER LEVEL TROUGH MOVING THROUGH THE NORTHWEST FLOW. BEHIND THE SURFACE
FEATURE NORTHWEST WINDS WILL INCREASE AS THE PRESSURE GRADIENT
TIGHTENS AND STRONGER WINDS ABOVE THE SURFACE MIX DOWN. MEANWHILE
THE UPPER LEVEL SHORT WAVE TROUGH MOVES THROUGH...BRINGING SOME
MOISTURE AND INSTABILITY WITH IT. UNFORTUNATELY THE MOISTURE WILL
BE ABOVE 500MB WITH DRY AIR FROM 500MB TO THE SURFACE...ALLOWING
ANY PRECIPITATION THAT MAY FORM TO EVAPORATE BEFORE IT REACHES THE
SURFACE. THE SHORT WAVE WILL THEN PUSH THE CLOSED LOW ON EAST AS
IT MOVES OUT OF THE AREA.
TEMPERATURE-WISE OBSERVATIONS FROM YESTERDAY SHOW THE EXCESSIVE SNOW
COVER IS HAVING A SIGNIFICANT EFFECT. AS SUCH WENT BELOW MOST
GUIDANCE FOR TEMPERATURES FOR AREAS WITH EXCESSIVE SNOW COVER. WITH
WARMING TEMPERATURES THROUGH THE PERIOD...SNOW COVER SHOULD HAVE
LESS OF AN EFFECT AS IT MELTS.
TEMPERATURES WILL GRADUALLY WARM THROUGH THE PERIOD AS WEST TO
NORTHWEST WINDS BRING WARMER AIR INTO THE AREA. HIGH TEMPERATURES
WILL WARM 5 TO 10 DEGREES ABOVE NORMAL BY MONDAY. LOW TEMPERATURES
WILL BE NEAR NORMAL EXCEPT FOR AREAS THAT STILL HAVE EXCESSIVE SNOW
COVER...WHICH WILL HAVE LOW TEMPERATURES 5 TO 10 DEGREES BELOW
NORMAL.
JTL
.LONG TERM (TUESDAY-FRIDAY)...
224 AM MST SAT DEC 24 2011
FOR THE PERIOD TUESDAY THROUGH FRIDAY...PROGRESSIVE PATTERN WILL BE
IN PLACE ACROSS THE CONUS WITH A SERIES OF FAST MOVING AND WEAK
SYSTEMS. THE ONLY ONE THAT APPEARS TO HAVE EVEN A SLIGHT CHANCE OF
BRINGING PRECIPITATION TO THE AREA WILL BE ON THURSDAY NIGHT...BUT
IT WOULD BE VERY LIGHT IF IT OCCURS AT ALL. DEEP WESTERLY FLOW WILL
DOMINATE AND RESULT IN LIMITED MOISTURE. THERE IS NO COLD AIR IN
SIGHT AND TEMPERATURES WILL BE ABOVE NORMAL THE ENTIRE PERIOD. /024
024
&&
.AVIATION...
402 PM MST FRI DEC 23 2011
VFR CONDS EXPECTED NEXT 24 HOURS AT BOTH TERMINALS AS HIGH PRESSURE
WILL BE IN CONTROL OF THE WEATHER PATTERN.
BAS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
THE PREVIOUS SHORT TERM FORECAST DISCUSSION FOLLOWS...
/TODAY THROUGH MONDAY/
EARLY THIS MORNING...AN UPPER LEVEL SHORTWAVE WAS PASSING NORTHEAST OF
THE AREA THROUGH THE EASTERN GREAT LAKES REGION. MEANWHILE RIDGING
WAS CENTERED TO THE SOUTH AND EAST OF BERMUDA OFF OF THE SOUTHEASTERN
US COAST WITH SOME SHORTWAVE RIDGING OVER THE SOUTHEASTERN STATES. AN
UPPER LEVEL LOW WAS CENTERED NOT FAR FROM KELP WITH A FEW RATHER WEAK
SOUTHERN STREAM SHORTWAVES ROTATING AROUND THIS UPPER LOW. ANOTHER
SHORTWAVE TROUGH WAS ENTERING THE UPPER MIDWEST AND NORTHERN MS
VALLEY. AT THE SFC...HIGH PRESSURE WAS CENTERED OVER THE SOUTHERN
PLAINS WITH RIDGING EXTENDING EAST INTO THE LOWER OH AND TN VALLEYS.
THE COLD FRONT ASSOCIATED WITH THE SYSTEM THAT BROUGHT RAIN ON THU WAS
SOUTH OF THE AREA STALLED OUT OVER THE GULF OF MEXICO. A RATHER WEAK
SFC SYSTEM WAS MOVING THROUGH THE CANADIAN PLAINS ASSOCIATED WITH THE
SHORTWAVE ENTERING THE UPPER MS VALLEY.
THROUGH SUNDAY THE CLOSED LOW NOW NEAR KELP WILL MEANDER INTO THE TX
PANHANDLE BY 0Z MON. AT THE SAME TIME...THE SHORTWAVE NOW ENTERING
THE UPPER MS VALLEY REGION WILL MOVE RATHER QUICKLY ACROSS THE
NORTHERN GREAT LAKES AND ACROSS ONTARIO AND INTO QUEBEC AND DAMPEN BY
THE END OF THE PERIOD...WITH ANOTHER UPSTREAM SHORTWAVE TROUGH
DIGGING SOUTHEAST ACROSS THE GREAT LAKES AND REACH THE EASTERN GREAT
LAKES BY SUN EVENING. THIS WILL LEAD TO WESTERLY FLOW ALOFT TODAY AND
THEN GRADUALLY BECOMING MORE NW WITH SHORTWAVES PASSING NORTH OF THE
REGION. SHORTWAVE RIDING IS PROGGED TO BRIEFLY BUILD INTO THE REGION
ON SUN NIGHT BEFORE SHIFTING EAST BY THE END OF THE PERIOD. THE
UPPER LEVEL LOW WILL MOVE TOWARD THE ARKLATEX REGION AND LEAD TO SFC
LOW PRESSURE DEVELOPING ALONG THE OLD BOUNDARY OVER THE GULF COAST
STATES. SOUTHERLY FLOW WILL INCREASE BY LATE MON BETWEEN A DEPARTING
SFC HIGH AND THE DEVELOPING SYSTEM...LEADING TO THE POTENTIAL FOR
PRECIP LATE OVER THE SW CWA.
THE MAIN WEATHER CONCERNS DURING THE NEAR TERM PERIOD ARE THE TIMING
OF THE CLEARING TOWARD DAWN OR EARLY ON SAT AND THE POTENTIAL FOR
VALLEY FOG TONIGHT AND HOW EXTENSIVE IT MIGHT BE. OTHERWISE...UNTIL
LATE IN THE PERIOD...SFC HIGH PRESSURE WILL GENERALLY REMAIN IN
CONTROL OF THE WEATHER WITH SYSTEMS PASSING BY TO THE NORTH AND SOUTH
OF THE REGION. THIS PATTERN SHOULD LEAD TO NEAR TO SLIGHTLY ABOVE
NORMAL TEMPS THROUGH THE PERIOD. MAX T SHOULD END UP A COUPLE OF
DEGREES ABOVE NORMAL TODAY...ON THE ORDER OF 5 TO 10 DEGREE ABOVE
NORMAL ON SUN AND AROUND 5 DEGREES ABOVE NORMAL ON MON. THE MODEL
GUIDANCE OVERALL POINTED TO A SLIGHTLY LARGER RIDGE/VALLEY TEMP SPLIT
FOR TONIGHT AND SUN NIGHT. THIS CORRESPONDS TO LESS IN THE WAY OF
CLOUD COVER AND JUST CIRRUS ON SAT NIGHT AND SUN ON THE FRINGES OF
WEAK WAVES PASSING TO OUR SOUTH. LESS CLOUD COVER ON SUN SHOULD LEAD
TO WARMER MAX T THAN THE PREVIOUS FORECAST. WE OPTED TO TREND UPWARD
TOWARD THE LOWER END OF GUIDANCE FOR MAX T ON SUN AND ALSO FOLLOWED
THE UPWARD TREND IN GUIDANCE ON MON IN WARM ADVECTIVE PATTERN/DOWNSLOPING
PATTERN IN ADVANCE OF THE DEVELOPING SYSTEM TO OUR SOUTHWEST.
.LONG TERM.../MONDAY NIGHT THROUGH FRIDAY/
CONFIDENCE CONTINUES TO GROW IN ANOTHER ROUND OF WIDESPREAD RAINFALL
MONDAY NIGHT THROUGH EARLY TUESDAY MORNING FOR EASTERN KENTUCKY...AS
AN UPPER LEVEL LOW TRACKS FROM THE ARKLATEX REGION THROUGH THE
TENNESSEE VALLEY...WHILE A NORTHERN STREAM TROUGH SWINGS BY IN
TANDEM FROM THE NORTHERN PLAINS THROUGH THE GREAT LAKES. THE GFS AND
ECMWF ARE CURRENTLY IN VERY GOOD AGREEMENT WITH THE TRACK AND
MAGNITUDE OF THESE FEATURES. THIS ALSO TRANSLATES TO THE SURFACE AS
WELL...AS LOW PRESSURE TRACKS NORTHEAST AND INTENSIFIES AS IT MOVES
ACROSS APPALACHIANS AND EVENTUALLY INTO THE MID-ATLANTIC.
RAIN WILL TAPER OFF FROM WEST TO EAST TUESDAY MORNING...WITH COLDER
AIR FILTERING IN. THE AIR MASS WILL BECOME MARGINAL FOR SOME
SNOW...HOWEVER IT LOOKS AS THOUGH THE DEEPER MOISTURE SUPPORTIVE OF
ICE CRYSTALS MAY EXIT A BIT TOO QUICKLY...SO WILL LEAVE OUT THIS
MENTION FOR NOW.
ONCE THIS SYSTEM EXITS...THE FLOW PATTERN WILL BECOME MORE
ZONAL...WITH MAINLY SOME NORTHERN STREAM PASSING SHORT WAVE TROUGHS
TO CONTEND WITH FROM TIME TO TIME. THE GFS HAS PLAYED UP THE
MOISTURE WITH ONE OF THESE FEATURES ON THURSDAY...WHILE THE ECMWF
HAS KEPT THINGS DRY. HAVE LEANED CLOSER TO THE DRIER SOLUTION FOR
NOW...AS THIS FOLLOWS CONTINUITY WELL FROM PREVIOUS MODEL RUNS. THE
NEXT SYSTEM OF INTEREST IN THE FORM OF A COLD FRONT WILL APPROACH BY
EARLY NEXT WEEKEND.
TEMPERATURES WILL CONTINUE TO RUN OVERALL NEAR OR JUST SLIGHTLY
ABOVE NORMAL THROUGH THE PERIOD.
&&
.AVIATION.../18Z TO 18Z/...UPDATED
AREA OF SC CONTINUES TO DRIFT NORTHEAST AND DIMINISH IN COVERAGE. THE
PATCHY SC IS GENERALLY NORTHEAST OF A LINE FROM FLEMINGSBURG TO
HAZARD TO PIKEVILLE. EXPECT THE SC TO CONTINUE TO DIMINISH. WHILE A
FEW SPOTS IN THE NORTHEAST PART OF THE FORECAST AREA MAY EXPERIENCE
AN HOUR TO TWO OF BROKEN MVFR CEILINGS THIS AFTERNOON...MOST AREAS
WILL REMAIN VFR. HIGH PRESSURE WILL THEN BRING MAINLY VFR CONDITIONS
THROUGH CHRISTMAS DAY. SOME LOCALIZED FOG AND IFR CONDITIONS ARE
EXPECTED LATE TONIGHT AND EARLY SUNDAY MORNING NEAR BODIES OF WATER.
DO NOT EXPECT FOG TO AFFECT THE TAF SITES HOWEVER.
&&
.JKL WATCHES/WARNINGS/ADVISORIES...NONE.
&&
$$
SHORT TERM...JP/SBH
LONG TERM....GEOGERIAN
AVIATION...SBH
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
306 PM EST SAT DEC 24 2011
.SYNOPSIS...
A BROAD AREA OF HIGH PRESSURE WITH SHIFT EASTWARD ACROSS THE AREA
FOR A MOSTLY DRY CHRISTMAS WEEKEND. ON SUNDAY NIGHT, A WEAK
DISTURBANCE WILL PASS NORTHEAST OF THE AREA, BRINGING THE CHANCE
OF SNOW SHOWERS NORTHEAST OF PITTSBURGH. HIGH PRESSURE WILL THEN
BUILD IN AND BRING A DRY START TO NEXT WEEK.
&&
.NEAR TERM /THROUGH SUNDAY/...
THE LATEST RUC ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A ZONAL
MID-LEVEL FLOW WITH A DEEP LAYER OF DRY AIR ABOVE 850MB. AT THE
SURFACE, OBS/MSAS INDICATE THE EASTERN US BEING DOMINATED BY TWO
HIGHS, ONE CENTERED IN QUEBEC AND ANOTHER ACROSS THE TENNESSEE
VALLEY. THE LOW-LEVEL FLOW HAS BECOME MORE WESTERLY, CUTTING OFF
THE LAKE ERIE MOISTURE TRAJECTORY. DEEP SUBSIDENCE ALOFT IS
ALLOWING FOR DRY WEATHER.
TONIGHT THROUGH EARLY SUNDAY...850MB FLOW WILL SHIFT FROM WESTERLY
TO SOUTHWESTERLY, ALLOWING FOR MORE DRY AIR IN THE LOWER LEVELS
TO ADVECT INTO THE AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE
SOUTHWEST. THIS WILL ALLOW FOR CLEAR SKIES OVERNIGHT AND ABUNDANT
SUNSHINE EARLY ON CHRISTMAS.
LATE ON CHRISTMAS DAY...GFS/NAM SOLUTIONS INDICATE A MID-LEVEL
TROUGH PASSING FROM THE NORTHERN GREAT LAKES INTO WESTERN NY. AREAS
NORTHEAST OF PITTSBURGH WILL BE ON THE SOUTHWESTERN EDGE OF MOISTURE
WITH THIS SYSTEM, WITH SNOW SHOWERS POSSIBLE THERE BEGINNING SUNDAY
EVENING. TEMPERATURES WILL BE ABOVE 5 DEGREES ABOVE NORMAL THROUGH
THIS PERIOD.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
THERE IS STRONG MODEL AGREEMENT THAT THE 500MB TROUGH AXIS WILL
SHIFT FROM THE EASTERN GREAT LAKES INTO NEW ENGLAND ON SUNDAY NIGHT
AND THE LOW AND MID-LEVEL FLOW WILL BECOME NORTHWESTERLY. ALTHOUGH
MOST MODELS TAKE THE BULK OF PRECIPITATION NORTHEAST OF THE AREA
WITH THIS FEATURE, THE 4KM NAM AND CANADIAN SOLUTIONS ARE
CONSIDERED, BRINGING SCHC POPS INTO SOUTHWEST PA AND CHC POPS
NORTHEAST OF PITTSBURGH. 1000-500MB 5400M LINE WILL BE WELL SOUTH OF
THE AREA, WITH ANY PRECIPITATION ALL IN THE FORM OF SNOW SHOWERS.
ANY ACCUMULATION WILL BE LESS THAN AN INCH, AS BEST FORCING REMAINS
NORTHEAST OF THE AREA WITH THIS SYSTEM.
MONDAY...ANY LINGERING SNOW SHOWERS ACROSS THE NORTHEAST OF
PITTSBURGH WILL QUICKLY DIMINISH BY THE AFTERNOON AS A 850MB
RIDGE ALLOWS THE FLOW TO BECOME MORE WESTERLY, HIGH PRESSURE
CROSSES THE AREA, AND DRIER AIR FILTERS INTO THE AREA.
CYCLOGENESIS ACROSS THE MS VALLEY WILL BEGIN LATE IN THE DAY AS A
CLOSED LOW SWINGS ACROSS THE SOUTHERN PLAINS. A SOUTHWESTERLY FLOW
ALOFT AHEAD OF THIS FEATURE WILL ALLOW FOR WARM AIR ADVECTION TO
ENSUE. THIS WILL ALSO CONTRIBUTE TO DECREASED CLOUD COVERAGE. THIS
HAS ALSO BEEN ACCOUNTED FOR IN THE FORECAST TEMPS, WITH HIGHS A
FEW DEGREES ABOVE A MAV/MET BLEND.
MONDAY NIGHT AND TUESDAY...THE CLOSED LOW WILL OPEN INTO A TROUGH AS
IT SWINGS INTO THE OHIO VALLEY, WITH THE SURFACE LOW TRACKING ACROSS
THE TENNESSEE VALLEY. THIS WILL ALLOW FOR STRONG WARM AIR ADVECTION
WITH TEMPS WARMING TO THE LOWER TO MID 40S BY DAWN TUESDAY. RAIN
WILL MOVE INTO EASTERN OHIO AFTER MIDNIGHT WILL ALL OPERATIONAL
MODELS SHOWING A SIMILAR SOLUTION, WITH THE LOW PASSING SOUTHEAST
OF THE AREA ON TUESDAY. WITH THIS IN MIND, LIKELY POPS ARE FORECAST
THROUGHOUT THE DAY. A HALF OF AN INCH TO AN INCH OF PRECIPITATION
WILL BE POSSIBLE WITH THIS SYSTEM.
THERE IS STILL SOME UNCERTAINTY WITH PRECIP TYPE WITH THIS SYSTEM,
AS SURFACE TEMPS MAY BE COLD ENOUGH FOR FREEZING RAIN NORTH OF
PITTSBURGH AT THE ONSET MONDAY NIGHT TO NEAR DAWN ON TUESDAY. 850
TEMPS WILL BE WARM ENOUGH THAT PRECIP SHOULD FALL AS ALL LIQUID,
SO WILL NEED TO MONITOR THIS IN FUTURE FORECAST RUNS. FOR NOW,
MIXED PRECIP IS FORECAST TO EXPRESS UNCERTAINTY. AS THE LOW
SHIFTS EAST OF THE AREA, COLD AIR WILL WRAP INTO THE BACK EDGE OF
THE SYSTEM, WITH THICKNESSES DECREASING AND A CHANGEOVER TO SNOW
LATE ON MONDAY. TEMPS WILL BE AROUND 10 DEGREES ABOVE NORMAL
DURING THE DAY TUESDAY, UNTIL COLD AIR ADVECTION ALLOWS WITH TEMPS
TO DROP INTO THE MID 30S BY EVENING ON THE BACK SIDE OF THE
SYSTEM.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
MIXED RAIN AND SNOW SHOWERS WILL CHANGE OVER TO SNOW BEFORE
DIMINISHING TUESDAY NIGHT. SURFACE RIDGE SHOULD BRING A GENERALLY
DRY FORECAST FOR WEDNESDAY. FAST MOVING SYSTEMS IN WAVY ZONAL FLOW
WILL BRING ABOVE NORMAL TEMPERATURES AND A CHANCE OF RAIN OR SNOW
SHOWERS THURSDAY INTO SATURDAY. CLOSE TO HPC PROGS WHICH TREND
TOWARD ECMWF.
&&
.AVIATION /20Z SATURDAY THROUGH THURSDAY/...
PATCHES OF MVFR STRATUS WILL EXIT NORTHEAST THIS EVENING WITH
GENERAL VFR THROUGH TAF PERIOD AS NEXT CLIPPER TYPE SYSTEM HEADS
ACROSS NORTHERN GREAT LAKES CHRISTMAS DAY. THIS WILL ALLOW SKIES TO
CLEAR OVERNIGHT AS FLOW BECOMES SOUTHWEST AHEAD OF SYSTEM.
INCREASING PRESSURE GRADIENT BY MID MORNING SATURDAY WILL ALLOW FOR
SOUTHWEST WINDS TO GUST TO 25KTS. A MID DECK WILL BEGIN TO
OVERSPREAD THE REGION DURING THE DAY.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...A COLD FRONT ON BACKSIDE
OF SYSTEM EXITING EASTERN GREAT LAKES MAY BRING BRIEF RESTRICTIONS
SUNDAY NIGHT. VFR UNDER HIGH PRESSURE MONDAY. A STORM SYSTEM
MOVING NORTHEAST FROM THE SOUTHERN PLAINS WILL BRING RESTRICTIONS
LATER MONDAY NIGHT THROUGH TUESDAY NIGHT. GENERAL VFR WEDNESDAY WITH
RESTRICTIONS POSSIBLE THURSDAY AHEAD OF A WEAK COLD FRONT.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1244 PM EST SAT DEC 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR A MOSTLY DRY HOLIDAY WEEKEND. THE
NEXT CHANCE FOR SNOW SHOWERS CAN BE EXPECTED LATE ON SUNDAY FOR
AREAS NORTH AND EAST OF PITTSBURGH AS A DISTURBANCE MOVES ACROSS
THE NORTHEAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN
ISSUED TO INCREASE SKY GRIDS TO ACCOUNT FOR DIURNAL CUMULUS WHICH
HAS DEVELOPED.
THE LATEST RUC ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A ZONAL
MID-LEVEL FLOW WITH A DEEP LAYER OF DRY AIR ABOVE 850MB. AT THE
SURFACE, OBS/MSAS INDICATE THE EASTERN US BEING DOMINATED BY TWO
HIGHS, ONE CENTERED IN QUEBEC AND ANOTHER ACROSS THE TENNESSEE
VALLEY. THE LOW-LEVEL FLOW HAS BECOME MORE WESTERLY, CUTTING OFF
THE LAKE ERIE TRAJECTORY. THUS, SCATTERED FLURRIES HAVE
DIMINISHED AND DEEP SUBSIDENCE ALOFT IS ALLOWING FOR DRY WEATHER.
THIS AFTERNOON...CLOUD COVERAGE WILL BEGIN TO DECREASE LATE IN
THE DAY WITH HIGH PRESSURE AND THE DEEP LAYER OF DRY AIR ALOFT IN
PLACE. HIGHS TODAY ARE CLOSER TO THE COOLER MAV GUIDANCE, RANGING
FROM THE MID 30S ACROSS THE I-80 CORRIDOR AND THE EASTERN RIDGES
TO THE LOWER 40S ACROSS EASTERN OHIO AND NORTH-CENTRAL WV.
TONIGHT...850MB FLOW WILL SHIFT FROM WESTERLY TO SOUTHWESTERLY,
ALLOWING FOR MORE DRY AIR IN THE LOWER LEVELS TO ADVECT INTO THE
AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE SOUTHWEST. THIS
WILL ALLOW FOR CLEAR SKIES OVERNIGHT. OVERNIGHT LOWS ARE CLOSEST
TO A MAV/MET BLEND, RANGING FROM THE MID TO UPPER 20S ACROSS THE
AREA.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
THE NEXT IN SERIES OF SHORTWAVES IS PROGGED FOR A SUNDAY CROSSING
OF THE GREAT LAKES REGION. HAVE PERSISTED WITH SMALL SNOW CHANCES
FOR AREAS NORTH AND EAST OF PITTSBURGH FOR PASSAGE OF THAT FEATURE.
GIVEN PROGRESSIVE NATURE OF THE SYSTEM...ABOVE FREEZING BOUNDARY
LAYER TEMPERATURES IN THE AFTERNOON AND EARLY EVE...AND A LIMITED
MIXING LAYER...NO SIGNIFICANT ACCUMULATION CAN BE ANTICIPATED.
A DRY MONDAY IS FORECAST UNDER SHORTWAVE RIDGING...BUT THE ADVANCE
OF A MODEL-AGREED SOUTHERN STREAM LOW MAY START SPREADING FAIRLY
WIDESPREAD PRECIP OVER THE AREA BY TUESDAY MORNING. CONFIDENCE IN
TIMING/PHASING IS SUFFICIENT FOR LIKELY POPS...BUT TEMPERATURE
PROFILES REMAIN QUESTIONABLE AND WILL BE DEPENDENT ON ACTUAL
TRACK OF THE LOW. GIVEN TODAYS MODEL PROGNOSIS...A WINTRY MIX OF
PRECIP IS POSSIBLE BEFORE WARM ADVECTION CHANGES THAT MIX TO RAIN
ON TUESDAY.
SHORT TERM TEMPERATURES WERE PROJECTED ABOVE NORMAL USING A BLEND
OF THE LATEST NAM AND GFS GUIDANCE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SURFACE RIDGE IN THE WAKE OF THE TUESDAY SYSTEMS SHOULD BRING A
GENERALLY DRY FORECAST FOR WEDNESDAY AND THURSDAY. NEXT SYSTEM IS
FORECAST OUT OF THE CENTRAL PLAINS ON FRIDAY AND WAS COVERED WITH
CHANCE POPS. TEMPERATURES WILL AVERAGE ABOVE NORMAL THROUGH PERIOD AS
ARCTIC AIR IS BOTTLED UP WELL NORTH ACROSS CANADA.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
PATCHES OF MVFR STRATUS WILL EXIT NORTHEAST THIS AFTERNOON WITH GENERAL
VFR THROUGH TAF PERIOD AS NEXT CLIPPER TYPE SYSTEM HEADS ACROSS
NORTHERN GREAT LAKES CHRISTMAS DAY. THIS WILL ALLOW SKIES TO CLEAR
OVERNIGHT AS FLOW BECOMES SOUTHWEST AHEAD OF SYSTEM. INCREASING
PRESSURE GRADIENT BY MID MORNING SATURDAY WILL ALLOW FOR
SOUTHWEST WINDS TO GUST TO 25KTS. A MID DECK WILL BEGIN TO
OVERSPREAD THE REGION DURING THE DAY.
OUTLOOK...SUNDAY NIGHT THROUGH THURSDAY...A COLD FRONT ON BACKSIDE
OF SYSTEM EXITING EASTERN GREAT LAKES MAY BRING BRIEF RESTRICTIONS
SUNDAY NIGHT. VFR UNDER HIGH PRESSURE MONDAY. A STORM SYSTEM
MOVING NORTHEAST FROM THE SOUTHERN PLAINS WILL BRING RESTRICTIONS
LATER MONDAY NIGHT THROUGH TUESDAY NIGHT. GENERAL VFR THURSDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1212 PM EST SAT DEC 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL ALLOW FOR A MOSTLY DRY HOLIDAY WEEKEND. THE
NEXT CHANCE FOR SNOW SHOWERS CAN BE EXPECTED LATE ON SUNDAY FOR
AREAS NORTH AND EAST OF PITTSBURGH AS A DISTURBANCE MOVES ACROSS
THE NORTHEAST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AN EARLY AFTERNOON ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN
ISSUED TO INCREASE SKY GRIDS TO ACCOUNT FOR DIURNAL CUMULUS WHICH
HAS DEVELOPED.
THE LATEST RUC ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A ZONAL
MID-LEVEL FLOW WITH A DEEP LAYER OF DRY AIR ABOVE 850MB. AT THE
SURFACE, OBS/MSAS INDICATE THE EASTERN US BEING DOMINATED BY TWO
HIGHS, ONE CENTERED IN QUEBEC AND ANOTHER ACROSS THE TENNESSEE
VALLEY. THE LOW-LEVEL FLOW HAS BECOME MORE WESTERLY, CUTTING OFF
THE LAKE ERIE TRAJECTORY. THUS, SCATTERED FLURRIES HAVE
DIMINISHED AND DEEP SUBSIDENCE ALOFT IS ALLOWING FOR DRY WEATHER.
THIS AFTERNOON...CLOUD COVERAGE WILL BEGIN TO DECREASE LATE IN
THE DAY WITH HIGH PRESSURE AND THE DEEP LAYER OF DRY AIR ALOFT IN
PLACE. HIGHS TODAY ARE CLOSER TO THE COOLER MAV GUIDANCE, RANGING
FROM THE MID 30S ACROSS THE I-80 CORRIDOR AND THE EASTERN RIDGES
TO THE LOWER 40S ACROSS EASTERN OHIO AND NORTH-CENTRAL WV.
TONIGHT...850MB FLOW WILL SHIFT FROM WESTERLY TO SOUTHWESTERLY,
ALLOWING FOR MORE DRY AIR IN THE LOWER LEVELS TO ADVECT INTO THE
AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE SOUTHWEST. THIS
WILL ALLOW FOR CLEAR SKIES OVERNIGHT. OVERNIGHT LOWS ARE CLOSEST
TO A MAV/MET BLEND, RANGING FROM THE MID TO UPPER 20S ACROSS THE
AREA.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
THE NEXT IN SERIES OF SHORTWAVES IS PROGGED FOR A SUNDAY CROSSING
OF THE GREAT LAKES REGION. HAVE PERSISTED WITH SMALL SNOW CHANCES
FOR AREAS NORTH AND EAST OF PITTSBURGH FOR PASSAGE OF THAT FEATURE.
GIVEN PROGRESSIVE NATURE OF THE SYSTEM...ABOVE FREEZING BOUNDARY
LAYER TEMPERATURES IN THE AFTERNOON AND EARLY EVE...AND A LIMITED
MIXING LAYER...NO SIGNIFICANT ACCUMULATION CAN BE ANTICIPATED.
A DRY MONDAY IS FORECAST UNDER SHORTWAVE RIDGING...BUT THE ADVANCE
OF A MODEL-AGREED SOUTHERN STREAM LOW MAY START SPREADING FAIRLY
WIDESPREAD PRECIP OVER THE AREA BY TUESDAY MORNING. CONFIDENCE IN
TIMING/PHASING IS SUFFICIENT FOR LIKELY POPS...BUT TEMPERATURE
PROFILES REMAIN QUESTIONABLE AND WILL BE DEPENDENT ON ACTUAL
TRACK OF THE LOW. GIVEN TODAYS MODEL PROGNOSIS...A WINTRY MIX OF
PRECIP IS POSSIBLE BEFORE WARM ADVECTION CHANGES THAT MIX TO RAIN
ON TUESDAY.
SHORT TERM TEMPERATURES WERE PROJECTED ABOVE NORMAL USING A BLEND
OF THE LATEST NAM AND GFS GUIDANCE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SURFACE RIDGE IN THE WAKE OF THE TUESDAY SYSTEMS SHOULD BRING A
GENERALLY DRY FORECAST FOR WEDNESDAY AND THURSDAY. NEXT SYSTEM IS
FORECAST OUT OF THE CENTRAL PLAINS ON FRIDAY AND WAS COVERED WITH
CHANCE POPS. TEMPERATURES WILL AVERAGE ABOVE NORMAL THROUGH PERIOD AS
ARCTIC AIR IS BOTTLED UP WELL NORTH ACROSS CANADA.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
GENERAL VFR FORECAST THROUGH THE AFTERNOON WITH ISOLATED MVFR AS
LAST OF STRATUS EXITS.
MID-LEVEL WAA WILL ALLOW 85H WINDS TO SLOWLY VEER TO THE WEST AND
THEN TO THE SOUTHWEST LATER THIS AFTERNOON. THIS WILL DECAY THE VFR
CLOUD DECK AND SCT CLOUDS OUT BY LATE THIS AFT.
EXPECT VFR CONDITIONS TONIGHT.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
A COLD FRONT WILL BRING POSSIBLE RESTRICTIONS SUNDAY AFTERNOON INTO
SUNDAY NIGHT. VFR UNDER HIGH PRESSURE MONDAY. A STORM SYSTEM MOVING
NORTHEAST FROM THE SOUTHERN PLAINS WILL PROVIDE RESTRICTIONS TUESDAY
FOLLOWED BY GENERAL VFR WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1025 AM EST SAT DEC 24 2011
.SYNOPSIS...
STRAY FLURRIES WILL END EARLY TODAY AS A WEAK DISTURBANCE
COMPLETES A CROSSING OF THE UPPER OHIO VALLEY. THE NEXT CHANCE FOR
SNOW SHOWERS CAN BE EXPECTED LATE ON SUNDAY FOR AREAS NORTH AND
EAST OF PITTSBURGH AS ANOTHER TROUGH OF LOW PRESSURE MOVES ACROSS
THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO LINGER
FLURRIES NORTH OF PITTSBURGH INTO THE EARLY AFTERNOON AND TO
ACCOUNT FOR THE LATEST SKY AND TEMP TRENDS.
THE LATEST RUC ANALYSIS INDICATES THE UPPER OHIO VALLEY IN A ZONAL
MID-LEVEL FLOW WITH A DEEP LAYER OF DRY AIR ABOVE 850MB. AT THE
SURFACE, OBS/MSAS INDICATE THE EASTERN US BEING DOMINATED BY TWO
HIGHS, ONE CENTERED IN QUEBEC AND ANOTHER ACROSS THE TENNESSEE
VALLEY. THE HIGH IN QUEBEC IS DICTATING A NORTHWESTERLY LOW-LEVEL
FLOW OFF OF LAKE ERIE. THIS TRAJECTORY WITH 850MB TEMPS NEAR -10C
CONTINUES TO PRODUCE SCATTERED FLURRIES FOR AREAS NORTH OF
PITTSBURGH. OTHERWISE, DEEP SUBSIDENCE ALOFT HAS ALLOWED FOR DRY
WEATHER.
THIS AFTERNOON...THE 850MB FLOW WILL BECOME MORE WESTERLY TODAY,
WITH SCATTERED FLURRIES DIMINISHING NORTH OF PITTSBURGH. AFTER THIS
POINT, ASIDE FROM A FEW STRATOCUMULUS POCKETS, SKIES WILL BECOME
MOSTLY SUNNY WITH HIGH PRESSURE AND THE DEEP LAYER OF DRY AIR
ALOFT. HIGHS TODAY ARE CLOSER TO THE COOLER MAV GUIDANCE, WITH
HIGHS RANGING FROM THE MID 30S ACROSS THE I-80 CORRIDOR AND THE
EASTERN RIDGES TO THE LOWER 40S ACROSS EASTERN OHIO AND NORTH-
CENTRAL WV.
TONIGHT...850MB FLOW WILL SHIFT FROM WESTERLY TO SOUTHWESTERLY,
CUTTING OFF THE MOIST FLOW OFF LAKE ERIE AND ALLOWING DRIER AIR TO
ADVECT INTO THE AREA. HIGH PRESSURE WILL THEN BUILD IN FROM THE
SOUTHWEST. THIS WILL ALLOW FOR CLEAR SKIES OVERNIGHT. OVERNIGHT
LOWS ARE CLOSEST TO A MAV/MET BLEND, RANGING FROM THE MID TO UPPER
20S ACROSS THE AREA.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
THE NEXT IN SERIES OF SHORTWAVES IS PROGGED FOR A SUNDAY CROSSING
OF THE GREAT LAKES REGION. HAVE PERSISTED WITH SMALL SNOW CHANCES
FOR AREAS NORTH AND EAST OF PITTSBURGH FOR PASSAGE OF THAT FEATURE.
GIVEN PROGRESSIVE NATURE OF THE SYSTEM...ABOVE FREEZING BOUNDARY
LAYER TEMPERATURES IN THE AFTERNOON AND EARLY EVE...AND A LIMITED
MIXING LAYER...NO SIGNIFICANT ACCUMULATION CAN BE ANTICIPATED.
A DRY MONDAY IS FORECAST UNDER SHORTWAVE RIDGING...BUT THE ADVANCE
OF A MODEL-AGREED SOUTHERN STREAM LOW MAY START SPREADING FAIRLY
WIDESPREAD PRECIP OVER THE AREA BY TUESDAY MORNING. CONFIDENCE IN
TIMING/PHASING IS SUFFICIENT FOR LIKELY POPS...BUT TEMPERATURE
PROFILES REMAIN QUESTIONABLE AND WILL BE DEPENDENT ON ACTUAL
TRACK OF THE LOW. GIVEN TODAYS MODEL PROGNOSIS...A WINTRY MIX OF
PRECIP IS POSSIBLE BEFORE WARM ADVECTION CHANGES THAT MIX TO RAIN
ON TUESDAY.
SHORT TERM TEMPERATURES WERE PROJECTED ABOVE NORMAL USING A BLEND
OF THE LATEST NAM AND GFS GUIDANCE.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
SURFACE RIDGE IN THE WAKE OF THE TUESDAY SYSTEMS SHOULD BRING A
GENERALLY DRY FORECAST FOR WEDNESDAY AND THURSDAY. NEXT SYSTEM IS
FORECAST OUT OF THE CENTRAL PLAINS ON FRIDAY AND WAS COVERED WITH
CHANCE POPS. TEMPERATURES WILL AVERAGE ABOVE NORMAL THROUGH PERIOD AS
ARCTIC AIR IS BOTTLED UP WELL NORTH ACROSS CANADA.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
GENERAL VFR FORECAST THROUGH THE AFTERNOON WITH ISOLATED MVFR AS
LAST OF STRATUS EXITS.
MID-LEVEL WAA WILL ALLOW 85H WINDS TO SLOWLY VEER TO THE WEST AND
THEN TO THE SOUTHWEST LATER THIS AFTERNOON. THIS WILL DECAY THE VFR
CLOUD DECK AND SCT CLOUDS OUT BY LATE THIS AFT.
EXPECT VFR CONDITIONS TONIGHT.
OUTLOOK...SUNDAY THROUGH WEDNESDAY...
A COLD FRONT WILL BRING POSSIBLE RESTRICTIONS SUNDAY AFTERNOON INTO
SUNDAY NIGHT. VFR UNDER HIGH PRESSURE MONDAY. A STORM SYSTEM MOVING
NORTHEAST FROM THE SOUTHERN PLAINS WILL PROVIDE RESTRICTIONS TUESDAY
FOLLOWED BY GENERAL VFR WEDNESDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1215 PM EST SAT DEC 24 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE FROM THE PAC NW INTO
BC/ALBERTA AND MID/UPPER LEVEL TROUGHING FROM NE CANADA INTO THE ERN
GREAT LAKES RESULTING IN NW FLOW FROM CNTRL CANADA INTO THE GREAT
LAKES. ANOTHER IN A SERIES OF CLIPPER SHORTWAVES WAS MOVING INTO NW
MN. HOWEVER...THE SHRTWV WAS RELATIVELY WEAK AND SUPPORTED LITTLE
MORE THAN AN INCREASE IN COLDER MID CLOUDS AND A FEW FLURRIES. THE
NEXT MORE SIGNFICANT UPSTREAM SHRTWV THAT WILL MOVE INTO THE WRN
GREAT LAKES LATE TONIGHT INTO SUN MORNING WAS MOVING INTO NRN
ALBERTA. LOW LEVEL CONV ALONG A WEAK TROUGH FROM CNTRL UPPER MI INTO
NRN LAKE MI ALONG WITH LEFTOVER MOISTURE AND 850 MB TEMPS TO AROUND
-10C...CONTINUED TO SUPPORT A BAND OF LAKE ENHANCED SNOW SHOWERS
FROM NEAR BEAVER ISLAND TO NEWBERRY. SHSN INTENSITY HAD DIMINISHED
OVERNIGHT WITH ONLY OCNL VSBY INTO THE 1-3SM RANGE. AN UPSTREAM
TROUGH WAS MOVING THROUGH THE ERN DAKOTAS.
&&
.DISCUSSION...
TODAY...EXPECT THE LINGERING LAKE ENHANCED SNOW SHOWERS FROM NRN
LAKE MI INTO SE LUCE COUNTY TO DIMINISH THIS MORNING AS THE CONV
ALONG THE TROUGH WEAKENS AND SHIFTS TO THE EAST. THE BACK EDGE OF THE
LOWER CLOUDS OVER NW WI WAS ADVANCING QUICKLY ENOUGH SO THAT BY MID
TO LATE MORNING...SKIES SHOULD AT LEAST PARTAILLY CLEAR.
OTHERWISE...DRY WEATHER WILL PREVAIL AS THE FORCING AND ISENTROPIC
ASCENT WITH THE WEAK CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF
THE CWA. WAA WILL BRING A REBOUND IN TEMPS BACK INTO THE UPPER 20S
AND LOWER 30S.
SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN. THE
COMBINATION OF INCREASING 850-700 MB MOISTURE AND LIFT WITH THE
SHRTWV AND 850 MB TEMPS TO AROUND -10C WILL SUPPORT LAKE
EFFECT/ENHANCED SNOW FOR LOCATIONS FAVORED BY WNW FLOW. WITH ONLY
MODERATE INSTABILITY...ACCUMULATIONS ONLY AROUND AN INCH ARE
EXPECTED. SINCE LITTLE SYNOPTIC MOISTURE WILL BE AVBL... ONLY SLIGHT
CHANCE POPS WERE INCLUDED FOR LOCATIONS FARTHER INLAND FROM LAKE
SUPERIOR.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILDS INTO THE AREA
WITH STRONGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO
THE MID TO UPPER 30S. MDLS THE NEXT MORE SUBSTANTIAL SHRTWV MOVING
IN ON TUE WILL BRING IS EXPECTED TO BRING ENOUGH COLD AIR TO SET OFF
LES FOR NW TO NNW FLOW LOCATIONS. SNOWFALL POTENTIAL IS LESS CERTAIN
SINCE THE GEM/ECMWF FCST DROP 850 MB TEMPS TO AROUND -15C COMPARED
TO NEAR -11C...PER GFS. SINCE THE DEEPER MOISTURE WILL LIKELY MOVE
OUT QUICKLY...LES SHOULD END TUE NIGHT. GENERALLY MILD WEATHER WILL
CONTINUE INTO THE END OF THE WEEK WITH ONLY LIGHT PCPN IF ANY
EXPECTED ASSOCIATED WITH ANY ADDITIONAL SHORTWAVES MOVING
THROUGH/NEAR THE AREA.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
VFR CONDIITONS ARE EXPECTED AT ALL 3 TAF SITES THROUGH THIS
AFTERNOON. TROUGH WILL APPROACH AND CROSS UPPER MICHIGAN LATE
TONIGHT AND CHRISTMAS MORNING. MOISTURE IS LIMITED BUT EXPECT A
RETURN OF MVFR CIGS WITH ITS PASSAGE. VSBYS MAY EVEN LOWER INTO IFR
RANGE...ESPECIALLY AT CMX DURING THE MORNING WITH SOME LIGHT LAKE
EFFECT SNOW SHRAS AND BLOWING SNOW WITH GUSTY NORTHWEST WINDS.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
SW WINDS WILL INCREASE TODAY AHEAD OF THE NEXT TROUGH TO AFFECT
LK SUPERIOR. AS WINDS SHIFT NW ON SUNDAY BEHIND THE TROUGH THERE
COULD BE GALE GUSTS OVR CNTRL AND EASTERN LK SUPERIOR IN THE
MORNING. NEXT TROUGH WILL AFFECT LK SUPERIOR MONDAY INTO MONDAY
NIGHT. THIS TROUGH IS EVEN STRONGER AND THERE SHOULD BE SW GALES TO
35 KTS OVER MUCH OF LAKE SUPERIOR MONDAY INTO MONDAY EVENING. MORE
NW GALES ARE POSSIBLE BEHIND THE TROUGH ON TUESDAY OVR EASTERN LK
SUPERIOR. WINDS DIMINISH INTO WEDNESDAY AS HIGH PRESSURE MOVES
ACROSS THE UPR LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...MZ
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
628 AM EST SAT DEC 24 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE FROM THE PAC NW INTO
BC/ALBERTA AND MID/UPPER LEVEL TROUGHING FROM NE CANADA INTO THE ERN
GREAT LAKES RESULTING IN NW FLOW FROM CNTRL CANADA INTO THE GREAT
LAKES. ANOTHER IN A SERIES OF CLIPPER SHORTWAVES WAS MOVING INTO NW
MN. HOWEVER...THE SHRTWV WAS RELATIVELY WEAK AND SUPPORTED LITTLE
MORE THAN AN INCREASE IN COLDER MID CLOUDS AND A FEW FLURRIES. THE
NEXT MORE SIGNFICANT UPSTREAM SHRTWV THAT WILL MOVE INTO THE WRN GREAT LAKES
LATE TONIGHT INTO SUN MORNING WAS MOVING INTO NRN ALBERTA. LOW LEVEL
CONV ALONG A WEAK TROUGH FROM CNTRL UPPER MI INTO NRN LAKE MI ALONG
WITH LEFTOVER MOISTURE AND 850 MB TEMPS TO AROUND -10C...CONTINUED TO
SUPPORT A BAND OF LAKE ENHANCED SNOW SHOWERS FROM NEAR BEAVER ISLAND
TO NEWBERRY. SHSN INTENSITY HAD DIMINISHED OVERNIGHT WITH ONLY OCNL
VSBY INTO THE 1-3SM RANGE. AN UPSTREAM TROUGH WAS MOVING THROUGH THE
ERN DAKOTAS.
&&
.DISCUSSION...
TODAY...EXPECT THE LINGERING LAKE ENHANCED SNOW SHOWERS FROM NRN
LAKE MI INTO SE LUCE COUNTY TO DIMINISH THIS MORNING AS THE CONV
ALONG THE TROUGH WEAKENS AND SHIFTS TO THE EAST. THE BACK EDGE OF THE
LOWER CLOUDS OVER NW WI WAS ADVANCING QUICKLY ENOUGH SO THAT BY MID
TO LATE MORNING...SKIES SHOULD AT LEAST PARTAILLY CLEAR. OTHERWISE...DRY
WEATHER WILL PREVAIL AS THE FORCING AND ISENTROPIC ASCENT WITH THE
WEAK CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE CWA. WAA WILL
BRING A REBOUND IN TEMPS BACK INTO THE UPPER 20S AND LOWER 30S.
SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN. THE
COMBINATION OF INCREASING 850-700 MB MOISTURE AND LIFT WITH THE
SHRTWV AND 850 MB TEMPS TO AROUND -10C WILL SUPPORT LAKE
EFFECT/ENHANCED SNOW FOR LOCATIONS FAVORED BY WNW FLOW. WITH ONLY
MODERATE INSTABILITY...ACCUMULATIONS ONLY AROUND AN INCH ARE
EXPECTED. SINCE LITTLE SYNOPTIC MOISTURE WILL BE AVBL... ONLY SLIGHT
CHANCE POPS WERE INCLUDED FOR LOCATIONS FARTHER INLAND FROM LAKE
SUPERIOR.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILDS INTO THE AREA WITH
STRONGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. MDLS THE NEXT MORE SUBSTANTIAL SHRTWV MOVING IN ON TUE
WILL BRING IS EXPECTED TO BRING ENOUGH COLD AIR TO SET OFF LES FOR
NW TO NNW FLOW LOCATIONS. SNOWFALL POTENTIAL IS LESS CERTAIN SINCE THE
GEM/ECMWF FCST DROP 850 MB TEMPS TO AROUND -15C COMPARED TO NEAR
-11C...PER GFS. SINCE THE DEEPER MOISTURE WILL LIKELY MOVE OUT
QUICKLY...LES SHOULD END TUE NIGHT. GENERALLY MILD WEATHER WILL
CONTINUE INTO THE END OF THE WEEK WITH ONLY LIGHT PCPN IF ANY
EXPECTED ASSOCIATED WITH ANY ADDITIONAL SHORTWAVES MOVING
THROUGH/NEAR THE AREA.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
EXPECT MVFR CONDITIONS THIS MORNING AT CMX AND IWD AS LOW LEVEL
MOISTURE SITS OVER THE AREA. FARTHER TO THE E...LOW LEVEL MOISTURE
IS MORE PREVALENT...AND IS MOIST ENOUGH IN THE PRESENCE OF LIGHT
UPSLOPE SLY FLOW TO CAUSE IFR TO BRIEFLY LIFT CIGS AT SAW THROUGH
MID MORNING. AS THE SW WIND INCREASES LATER TODAY IN ADVANCE OF
DISTURBANCE MOVING E FROM THE PLAINS...VERY DRY AIR DEPICTED ON THE
00Z MPX RAOB WILL OVERSPREAD UPPER MI AND BRING VFR CONDITIONS. LOOK
FOR THE APPROACHING DISTURBANCE TO DRAG A LOW PRESSURE TROUGH ACROSS
THE U.P. THIS EVENING. SINCE THE AIRMASS IN THE NRN PLAINS IS SO DRY
PER THE 00Z BISMARCK RAOB/OBSERVATIONS NEAR THE TROUGH...VFR TO HIGH
END MVFR CONDITIONS ARE MOST LIKELY WITH THE TROF PASSAGE.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
SW WINDS WILL INCREASE TODAY AHEAD OF THE NEXT TROUGH TO AFFECT
LK SUPERIOR. AS WINDS SHIFT NW ON SUNDAY BEHIND THE TROUGH THERE
COULD BE GALE GUSTS OVR CNTRL AND EASTERN LK SUPERIOR IN THE
MORNING. NEXT TROUGH WILL AFFECT LK SUPERIOR MONDAY INTO MONDAY
NIGHT. THIS TROUGH IS EVEN STRONGER AND THERE SHOULD BE SW GALES TO
35 KTS OVER MUCH OF LAKE SUPERIOR MONDAY INTO MONDAY EVENING. MORE
NW GALES ARE POSSIBLE BEHIND THE TROUGH ON TUESDAY OVR EASTERN LK
SUPERIOR. WINDS DIMINISH INTO WEDNESDAY AS HIGH PRESSURE MOVES
ACROSS THE UPR LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...TITUS
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
533 AM EST SAT DEC 24 2011
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED A RIDGE FROM THE PAC NW INTO
BC/ALBERTA AND MID/UPPER LEVEL TROUGHING FROM NE CANADA INTO THE ERN
GREAT LAKES RESULTING IN NW FLOW FROM CNTRL CANADA INTO THE GREAT
LAKES. ANOTHER IN A SERIES OF CLIPPER SHORTWAVES WAS MOVING INTO NW
MN. HOWEVER...THE SHRTWV WAS RELATIVELY WEAK AND SUPPORTED LITTLE
MORE THAN AN INCREASE IN COLDER MID CLOUDS AND A FEW FLURRIES. THE
NEXT MORE SIGNFICANT UPSTREAM SHRTWV THAT WILL MOVE INTO THE WRN GREAT LAKES
LATE TONIGHT INTO SUN MORNING WAS MOVING INTO NRN ALBERTA. LOW LEVEL
CONV ALONG A WEAK TROUGH FROM CNTRL UPPER MI INTO NRN LAKE MI ALONG
WITH LEFTOVER MOISTURE AND 850 MB TEMPS TO AROUND -10C...CONTINUED TO
SUPPORT A BAND OF LAKE ENHANCED SNOW SHOWERS FROM NEAR BEAVER ISLAND
TO NEWBERRY. SHSN INTENSITY HAD DIMINISHED OVERNIGHT WITH ONLY OCNL
VSBY INTO THE 1-3SM RANGE. AN UPSTREAM TROUGH WAS MOVING THROUGH THE
ERN DAKOTAS.
&&
.DISCUSSION...
TODAY...EXPECT THE LINGERING LAKE ENHANCED SNOW SHOWERS FROM NRN
LAKE MI INTO SE LUCE COUNTY TO DIMINISH THIS MORNING AS THE CONV
ALONG THE TROUGH WEAKENS AND SHIFTS TO THE EAST. THE BACK EDGE OF THE
LOWER CLOUDS OVER NW WI WAS ADVANCING QUICKLY ENOUGH SO THAT BY MID
TO LATE MORNING...SKIES SHOULD AT LEAST PARTAILLY CLEAR. OTHERWISE...DRY
WEATHER WILL PREVAIL AS THE FORCING AND ISENTROPIC ASCENT WITH THE
WEAK CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE CWA. WAA WILL
BRING A REBOUND IN TEMPS BACK INTO THE UPPER 20S AND LOWER 30S.
SATURDAY NIGHT INTO SUNDAY...A SLIGHTLY STRONGER SHRTWV WILL MOVE
THROUGH THE WESTERN GREAT LAKES LATE SAT NIGHT INTO EARLY SUN. THE
COMBINATION OF INCREASING 850-700 MB MOISTURE AND LIFT WITH THE
SHRTWV AND 850 MB TEMPS TO AROUND -10C WILL SUPPORT LAKE
EFFECT/ENHANCED SNOW FOR LOCATIONS FAVORED BY WNW FLOW. WITH ONLY
MODERATE INSTABILITY...ACCUMULATIONS ONLY AROUND AN INCH ARE
EXPECTED. SINCE LITTLE SYNOPTIC MOISTURE WILL BE AVBL... ONLY SLIGHT
CHANCE POPS WERE INCLUDED FOR LOCATIONS FARTHER INLAND FROM LAKE
SUPERIOR.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILDS INTO THE AREA WITH
STRONGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. MDLS THE NEXT MORE SUBSTANTIAL SHRTWV MOVING IN ON TUE
WILL BRING IS EXPECTED TO BRING ENOUGH COLD AIR TO SET OFF LES FOR
NW TO NNW FLOW LOCATIONS. SNOWFALL POTENTIAL IS LESS CERTAIN SINCE THE
GEM/ECMWF FCST DROP 850 MB TEMPS TO AROUND -15C COMPARED TO NEAR
-11C...PER GFS. SINCE THE DEEPER MOISTURE WILL LIKELY MOVE OUT
QUICKLY...LES SHOULD END TUE NIGHT. GENERALLY MILD WEATHER WILL
CONTINUE INTO THE END OF THE WEEK WITH ONLY LIGHT PCPN IF ANY
EXPECTED ASSOCIATED WITH ANY ADDITIONAL SHORTWAVES MOVING
THROUGH/NEAR THE AREA.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
EXPECT VFR CONDITIONS THIS MRNG AT CMX AND IWD WITH LLVL DRY AIR
DOMINATING. FARTHER TO THE E...THE LLVLS ARE MOIST ENUF IN THE
PRESENCE OF LIGHT UPSLOPE SLY FLOW TO MAINTAIN SC/MVFR CIGS AT SAW
THRU SUNRISE. AS THE SW WIND INCREASES LATER TODAY IN ADVANCE OF
DISTURBANCE MOVING E FM THE PLAINS...VERY DRY AIR DEPICTED ON THE
00Z MPX RAOB WL OVERSPREAD UPR MI AND BRING VFR CONDITIONS. LOOK FOR
THE APRCHG DISTURBANCE TO DRAG A LO PRES TROF ACROSS THE U.P. THIS
EVNG. SINCE THE AIRMASS IN THE NRN PLAINS IS SO DRY PER THE 00Z
BISMARCK RAOB/OBSERVATIONS NEAR THE TROF...VFR CONDITIONS ARE MOST
LIKELY WITH THE TROF PASSAGE. THE ONLY EXCEPTION MAY BE CMX...WITH
FAVORABLE UPSLOPE W WIND COMPONENT. LOOK FOR W WIND GUSTS AT THIS
EXPOSED LOCATION TO REACH 25-30 KTS.
&&
.MARINE /FOR THE 4 AM LAKE SUPERIOR FORECAST ISSUANCE/...
SW WINDS WILL INCREASE TODAY AHEAD OF THE NEXT TROUGH TO AFFECT
LK SUPERIOR. AS WINDS SHIFT NW ON SUNDAY BEHIND THE TROUGH THERE
COULD BE GALE GUSTS OVR CNTRL AND EASTERN LK SUPERIOR IN THE
MORNING. NEXT TROUGH WILL AFFECT LK SUPERIOR MONDAY INTO MONDAY
NIGHT. THIS TROUGH IS EVEN STRONGER AND THERE SHOULD BE SW GALES TO
35 KTS OVER MUCH OF LAKE SUPERIOR MONDAY INTO MONDAY EVENING. MORE
NW GALES ARE POSSIBLE BEHIND THE TROUGH ON TUESDAY OVR EASTERN LK
SUPERIOR. WINDS DIMINISH INTO WEDNESDAY AS HIGH PRESSURE MOVES
ACROSS THE UPR LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...KC
MARINE...TITUS
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1230 AM EST SAT DEC 24 2011
UPDATED AVIATION DISCUSSION FOR 06Z TAFS
.UPDATE...
ALTHOUGH NO MORE THAN AN INCH OF SN HAS FALLEN SO FAR IN LUCE COUNTY
PER CALLS TO SPOTTERS...LATEST RADAR IMAGERY SHOWS HIER
REFLECTIVITIES SHOWING UP IN NRN LK MI AND MOVING NEWD INTO CHIPPEWA
COUNTY TOWARD ERY. THE 00Z APX RAOB SHOWS DEEP MSTR THRU THE ENTIRE
TROP AND AN H85 TEMP OF -12C...PARAMETERS CONDUCIVE TO LK ENHANCED
SN IN AN AREA OF LARGE SCALE QVECTOR CNVGC ASSOCIATED WITH A FAIRLY
VIGOROUS SHRTWV DIGGING SEWD THRU WI. WITH SSW FLOW...EXPECT THE LK
ENHANCED SHSN NOW PUSHING TOWARD ERY TO IMPACT MAINLY THE SE HALF OF
LUCE COUNTY FOR AT LEAST THE NEXT COUPLE OF HRS. SO OPTED TO KEEP
THE GOING WINTER WX ADVY GOING FOR THAT COUNTY THRU MIDNGT. ALTHOUGH
SOME OF THE MORE RECENT HIER RES MODELS SHOW THE SHSN PERSISTING
EVEN BEYOND 06Z...LATEST RUC SHOWS SGNFT DEEP LYR QVECTOR DVGC/MID
LVL DRYING OVERSPREADING THE AREA FM THE W BY 06Z...CONSISTENT WITH
WARMING CLD TOPS OBSVD TO THE W ON RECENT IR STLT IMAGERY AND TRACK
OF SHRTWV TO THE SE AWAY FM THE AREA OF INTEREST. SO EXPECT SHSN
INTENSITY/COVERAGE TO DIMINISH AFT MIDNGT.
&&
.SHORT TERM /TONIGHT AND SATURDAY/ ISSUED AT 402 PM...
PRIMARY ISSUE IS LAKE ENHANCED SNOW OVER FAR EASTERN CWA THIS
EVENING.
CLIPPER LOW PRESSURE SYSTEM ON ITS WAY ACROSS UPR MI LATE THIS AFTN.
WV LOOP AND RAOBS FM 12Z POINT TO SHARP SHORTWAVE DIGGING ACROSS MN
AND NOW INTO SW WI. IR SATELLITE SHOWS GRADUALLY WARMING CLOUD TOP
TEMPS AS THE SYSTEM SNOW HAS PUSHED INTO CNTRL UPR MI AND EASTERN
WI. MOST CONCENTRATED MODERATE SNOW SHOULD END UP FALLING JUST ALONG
AND SOUTH OF THE WI BORDER ADJACENT TO TRACK OF COMPACT SHORTWAVE.
ELSEWHERE...DEEP LAYER Q-VECTOR CONVERGENCE AND BOUT OF ISENTROPIC
ASCENT ON 280K SFC /H7-H6/ WILL LEAD TO A LIGHT DUSTING OF SNOW WITH
ACCUMS UNDER AN INCH. THIS BOUT OF LGT SYSTEM SNOW EXPECTED TO TAPER
QUICKLY THIS EVENING WEST HALF OF CWA AS SUBSIDENCE SPREADS IN FM
MN.
FORCING FM SYSTEM IN PROCESS OF SPREADING ACROSS EASTERN UPR MI
WHICH BRINGS LAKE ENHANCEMENT OFF OF LK MICHIGAN INTO MIX THROUGH
THIS EVENING WITH H85 TEMPS AROUND -10C AND LK SFC TEMPS ROUGHLY
+6C. VISIBLE SATELLITE LOOP OVER PAST FEW HOURS SHOWS CLOUD ELEMENTS
STREAMING IN OFF LK HURON (SE WINDS) AND LK MICHIGAN (SSW WINDS)
CONVERGING OVR CNTRL MACKINAC COUNTY INTO SOUTHERN LUCE COUNTY.
PRESENCE OF THE LOW-LEVEL CONVERGENT FLOW ALLOWED SNOW TO BEGIN AS
EARLY AS MIDDAY AT KERY WITH REDUCED VSBY THROUGH THIS AFTN.
REGIONAL CANADIAN REALLY WAS ONLY HIGHER RESOLUTION MODEL TO
INDICATE SNOW SO EARLY AT KERY AND WILL CONTINUE TO FOLLOW ITS IDEA
FOR FCST THIS EVENING SHOWING WIND TRAJECTORIES FM 210-230 DIRECTION
FLOWING INTO EASTERN CWA. RESULT IS INCREASING LK ENHANCEMENT
THROUGH AROUND 03Z TONIGHT AS BULK OF STRONGER LARGER SCALE LIFT
SLIDES ACROSS AND INVERSION IS PRETTY MUCH ELIMANATED FOR A TIME.
EXPECT HEAVIEST SNOW /TOTALS UP TO 5 INCHES THROUGH MIDNIGHT/ TO
STAY JUST SOUTH AND SOUTHEAST OF CITY OF NEWBERRY WITH PROBABLY LESS
THAN 1 INCH OF SNOW OCCURRING FARTHER W AND NW AT MCMILLAN AND PINE
STUMP JUNCTION. WHERE THIS BAND OF ENHANCED SNOW SETS UP TRAVEL WILL
LIKELY BECOME QUITE DIFFICULT DUE TO SNOW COVERED ROADS AND POOR
VISIBILITY. HAZARD IS FURTHER HEIGHTENED SINCE TRAVEL VOLUME MAY BE
HIGHER DUE TO THE CHRISTMAS HOLIDAY WEEKEND. LAKE ENHANCED SNOW
HEADS EAST OUT OF THE CWA AFT MIDNIGHT ...LEAVING JUST A FEW LIGHTER
SNOW SHOWERS IN ITS WAKE. ELSEWHERE AFTER MID EVENING...SHOULD BE
FAIRLY QUIET AS LOW PRESSURE TROUGH FILLS OVR THE AREA. IF ENOUGH
LOW-LEVEL MOISTURE LINGERS...PERHAPS COULD SEE SOME FZDZ. BETTER
CHANCE FOR THIS WOULD BE OVER EASTERN CWA WITH MOISTURE FLOWING IN
OFF LK MICHIGAN.
LOOKING QUIET FOR SATURDAY. STILL A LOW RISK OF LINGERING LOW CLOUDS
AND MAYBE SOME FZDZ/FLURRIES EARLY. OTHERWISE...EXPECT INCREASING SW
WINDS AND SCT-BKN MID CLOUDS AHEAD OF ANOTHER LOW PRESSURE TROUGH IN
NW FLOW PATTERN. HIGHS SHOULD BE ABOVE NORMAL WITH READINGS UPR 20S
TO LWR 30S.
.LONG TERM 00Z SUN...
NAM SHOWS A 500 MB TROUGH NEAR LAKE WINNIPEG 00Z SUN THAT DIGS
SOUTHEAST INTO THE UPPER GREAT LAKES ON SUN. THIS TROUGH IS QUICKLY
FOLLOWED BY A 500 MB RIDGE OVER THE NORTHERN PLAINS 00Z MON AND THEN
ANOTHER TROUGH COMES INTO THE NORTHERN PLAINS 00Z TUE. NAM SHOWS
SOME 850-500 MB Q-VECTOR CONVERGENCE SAT NIGHT WITH DEEPER MOISTURE
MOVING THROUGH THE CWA AND BOTH MOVE OUT ON SUN. GFS AND ECMWF SHOW
ABOUT THE SAME THING AS THE NAM DOES. DID NOT MAKE TOO MANY CHANGES
TO THE GOING FORECAST FOR TEMPERATURES OR WEATHER. ONE THING WAS TO
CUT BACK ON POPS FOR SAT NIGHT AS COLD AIR DOES NOT GET IN UNTIL
SUNDAY WHEN LAKE EFFECT SNOW STARTS AS COLDER AIR AT 850 MB
TEMPERATURES DROP TO -10C ON SUNDAY. THIS WILL HAVE AN AFFECT OVER
THE WEST WITH LESS LAKE EFFECT FOR LATE SAT NIGHT. WINDS QUICKLY
BACK TO THE NORTHWEST WITH WARM AIR ADVECTION ON SUNDAY NIGHT INTO
MONDAY...SO DRY WEATHER WILL MOVE IN THEN. WILL GET BREEZY ON MONDAY
WITH THE WARM AIR ADVECTION AND WILL GET WARM WITH HIGHS ABOVE
NORMAL IN THE MID 30S TO LOWER 40S.
IN THE EXTENDED...GFS AND ECMWF SHOW A BROAD 500 MB RIDGE OVER THE
UPPER GREAT LAKES 12Z MON WITH A TROUGH IN THE CANADIAN PRAIRIES.
THE ECMWF BRINGS THIS TROUGH INTO THE UPPER GREAT LAKES 12Z TUE.
THIS MOVES OUT AND THE UPPER FLOW STAYS NW TO SE FOR WED INTO THU.
THIS WILL ALLOW A COLD FRONT TO BECOME STATIONARY ACROSS THE AREA
FOR THOSE TWO DAYS BEFORE A 500 MB TROUGH ARRIVES FOR FRI WITH AND
ALBERTA CLIPPER AFFECTING THE UPPER GREAT LAKES. COLD AIR COMES IN
WITH LAKE EFFECT FOR TUE AS THE ECMWF BRINGS IN SOME 850 MB
TEMPERATURES THAT FALL TO -14C TO -16C BY 00Z WED. SOME SLOW
MODIFICATION OCCURS WITH 850 MB TEMPERATURES OFF THE ECMWF WARMING
TO -6C OVER THE WEST AND -10C OVER THE EAST 12Z THU. 850 MB
TEMPERATURES THEN CONTINUE TO WARM AHEAD OF THE ALBERTA CLIPPER FOR
FRI. WITH THE FRONT AND THE COLD 850 MB TEMPERATURES AROUND THE
AREA...LAKE EFFECT AND SOME POPS WILL BE NEEDED FOR THE EXTENDED
PERIOD THROUGH MOST OF IT. TEMPERATURES LOOK TO STAY ABOVE NORMAL
THROUGH THE PERIOD WITH NO REAL COLD AIR IN SIGHT.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
EXPECT VFR CONDITIONS THIS MRNG AT CMX AND IWD WITH LLVL DRY AIR
DOMINATING. FARTHER TO THE E...THE LLVLS ARE MOIST ENUF IN THE
PRESENCE OF LIGHT UPSLOPE SLY FLOW TO MAINTAIN SC/MVFR CIGS AT SAW
THRU SUNRISE. AS THE SW WIND INCREASES LATER TODAY IN ADVANCE OF
DISTURBANCE MOVING E FM THE PLAINS...VERY DRY AIR DEPICTED ON THE
00Z MPX RAOB WL OVERSPREAD UPR MI AND BRING VFR CONDITIONS. LOOK FOR
THE APRCHG DISTURBANCE TO DRAG A LO PRES TROF ACROSS THE U.P. THIS
EVNG. SINCE THE AIRMASS IN THE NRN PLAINS IS SO DRY PER THE 00Z
BISMARCK RAOB/OBSERVATIONS NEAR THE TROF...VFR CONDITIONS ARE MOST
LIKELY WITH THE TROF PASSAGE. THE ONLY EXCEPTION MAY BE CMX...WITH
FAVORABLE UPSLOPE W WIND COMPONENT. LOOK FOR W WIND GUSTS AT THIS
EXPOSED LOCATION TO REACH 25-30 KTS.
&&
.MARINE /FOR THE 4 PM LAKE SUPERIOR FORECAST ISSUANCE/...
EXPECT SOUTHERLY WINDS TO 30 KTS TO DIMINISH THIS EVENING AS LOW
PRESSURE DIMINISHES OVR THE AREA. SW WINDS WILL INCREASE SATURDAY
AHEAD OF THE NEXT TROUGH TO AFFECT LK SUPERIOR. AS WINDS SHIFT NW
ON SUNDAY BEHIND THE TROUGH THERE COULD BE GALE GUSTS OVR CNTRL AND
EASTERN LK SUPERIOR IN THE MORNING. NEXT TROUGH WILL AFFECT LK
SUPERIOR MONDAY INTO MONDAY NIGHT. THIS TROUGH IS EVEN STRONGER AND
THERE SHOULD BE SW GALES TO 35 KTS OVER MUCH OF LAKE SUPERIOR MONDAY
INTO MONDAY EVENING. MORE NW GALES ARE POSSIBLE BEHIND THE TROUGH ON
TUESDAY OVR EASTERN LK SUPERIOR. WINDS DIMINISH INTO WEDNESDAY AS
HIGH PRESSURE MOVES ACROSS THE UPR LAKES.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...KC
SHORT TERM...JLA
LONG TERM...07
AVIATION...KC
MARINE...JLA
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
559 PM CST SUN DEC 25 2011
.UPDATE...
00Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
OUR STRETCH OF QUIET AND PREDOMINANTLY MILD WEATHER LOOKS TO
CONTINUE THROUGH THE FORESEEABLE FUTURE... WITH ONLY A FEW MINOR
SYSTEMS WITH WHICH TO BE CONCERNED. THERE ARE AT LEAST SOME
INDICATIONS FOR A BIT OF ACTIVITY DURING THE LATTER HALF OF THE
WEEK AS A FEW SYSTEMS TRACK A BIT CLOSER TO US... ALTHOUGH
INDICATIONS ARE THAT THEIR IMPACT MAY PRIMARILY BE FELT TO OUR
NORTH. THE MAIN WEATHER ITEM OF CONCERN LOOKS TO BE SOME GUSTY
WINDS TONIGHT INTO MONDAY AS THE PRESSURE GRADIENT SIGNIFICANTLY
TIGHTENS OVER THE AREA WITH A 992MB SURFACE LOW TRACKING EAST
THROUGH SOUTHERN CANADA. THE GFS AND NAM BOTH SUGGEST WINDS AOA 65
KT IN THE BOTTOM FEW THOUSAND FEET LATE TONIGHT INTO EARLY MONDAY.
ALTHOUGH THESE WON/T BE REALIZED AT THE SURFACE... LOCATIONS IN
THE WEST CENTRAL AND SOUTHWEST PORTION OF THE CWFA SHOULD SEE SOME
GUSTS ABOVE 40KT DURING THAT TIME FRAME GIVEN MORE FAVORABLE
TOPOGRAPHIC CONDITIONS IN THAT AREA... NAMELY THEIR EXPOSURE AND
POTENTIAL FOR DOWNSLOPE ENHANCEMENT IN THE LEE OF THE BUFFALO
RIDGE. GIVEN THIS POTENTIAL... WILL BE ISSUING A WIND ADVISORY FOR
THE OVERNIGHT INTO THE MORNING HOURS FOR PART OF THE WEST CENTRAL
AND SOUTHWEST CWFA. THE REMAINDER OF THE AREA SHOULD SEE GUSTY
WINDS DEVELOP AS WELL... BUT AT THIS POINT THE EXPECTATION IS THAT
THEY WILL REMAIN BELOW ADVISORY LEVELS OVER THE REMAINDER OF THE AREA.
IN THE BIG PICTURE... WATER VAPOR IMAGERY AND RUC UPPER AIR
ANALYSES SHOW A DEPARTING SHORTWAVE MOVING THROUGH THE GREAT
LAKES... WITH THE NEXT FEATURE ASCENDING THE RIDGE OVER THE
WESTERN STATES AND SOUTHWEST CANADA. THIS SHORTWAVE WILL HELP
DRIVE THE AFOREMENTIONED SURFACE LOW ACROSS SOUTHERN CANADA ON
MONDAY... WITH GUSTY SOUTHWEST WINDS AND SIGNIFICANT WARM
ADVECTION ACROSS OUR AREA. HIGH TEMPERATURES WILL BE WELL ABOVE
NORMAL ONCE AGAIN... AND A FEW SPOTS COULD APPROACH RECORDS. GIVEN
SOME UNCERTAINTY ON THE DEGREE OF MID AND HIGH CLOUDS DID NOT GO
WITH EXCEEDINGLY HIGH VALUES... ALTHOUGH STILL ROUGHLY 20 DEGREES
ABOVE NORMAL... SO THE OVERNIGHT SHIFT AND SHORT TERM FORECASTS ON
MONDAY WILL LIKELY NEED TO MAKE SOME REFINEMENTS. THE COLD FRONT
WILL PUSH ACROSS THE AREA DURING THE AFTERNOON AND EVENING
HOURS... AND LOOKS TO COME THROUGH PCPN-FREE. COOLER... YET STILL
ABOVE NORMAL... TEMPERATURES LOOK TO RETURN FOR TUESDAY. INCLUDED
A FEW FLURRIES FOR TUESDAY NIGHT INTO WEDNESDAY AS A LOBE OF WARM
ADVECTION AHEAD OF THE NEXT SYSTEM SWINGS ACROSS THE AREA. THE
NAM... GFS... SREF... AND ECMWF ALL WRING OUT SOME LIGHT PCPN WITH
THIS FEATURE... AND THERE IS A NARROW AXIS OF REDUCED CONDENSATION
PRESSURE DEFICITS COINCIDENT WITH THE BETTER ISENTROPIC ASCENT...
SO MAY NEED TO EVENTUALLY INTRODUCE SOME POPS. THE BAROCLINIC ZONE
LOOKS TO LINGER OVER THE AREA AS ANOTHER WEAK SHORTWAVE SWINGS BY
WEDNESDAY NIGHT... SO KEPT LOW CHANCE POPS TO ACCOUNT FOR THAT.
A MORE SUBSTANTIAL FEATURE CONTINUES TO BE ADVERTISED BY THE GFS
AND ECMWF DURING THE THURSDAY NIGHT-FRIDAY TIME FRAME. BOTH
SUGGEST A DECENT NORTHWEST-SOUTHEAST ORIENTED AREA OF MID LEVEL
FRONTOGENESIS ON THE NORTH SIDE OF A 995MB-ISH SURFACE LOW WHICH
TRACKS FROM CENTRAL NORTH DAKOTA THROUGH THE TWIN CITIES AREA AND
EVENTUALLY TO CENTRAL LAKE MICHIGAN. THERE IS A FAIRLY PROLONGED
PERIOD OF WEST TO SOUTHWESTERLY FLOW IN PLACE BEFORE THIS SYSTEM
MOVES INTO THE AREA... SO WE SHOULD HAVE A BETTER CHANCE OF SEEING
DEEP SATURATION AND SOME HEALTHIER PCPN AMOUNTS... AND INDEED BOTH
THE GFS AND ECMWF MANAGE TO PRODUCE MAX AMOUNTS NEAR A QUARTER OF
AN INCH. THE BIG QUESTION WILL BE WHERE EXACTLY THE BAND OF
PCPN... WHICH SHOULD BE IN THE FORM OF SNOW... WILL SETUP. AT THE
CURRENT TIME IT LOOKS LIKE THE BEST CHANCE WOULD BE ALONG AND
NORTH OF THE I-94 CORRIDOR GIVEN THE FORECAST POSITION OF THE
UPPER JET AND TRACK OF THE SURFACE LOW TOGETHER WITH THE MID-LEVEL
TEMPERATURE GRADIENT. OF COURSE... MUCH CAN CHANGE WITH SOMETHING
THAT IS EXPECTED 4-5 DAYS FROM NOW... SO AT THIS POINT JUST
INCLUDED CHANCE POPS FOR MUCH OF THE AREA... WITH HIGHER VALUES
OVER THE NORTHERN FORECAST AREA. IT CERTAINLY DOESN/T LOOK TO BE A
BARN-BURNER... BUT AT THIS POINT ANY SORT OF ORGANIZED
ACCUMULATING PCPN IS ATTENTION GRABBING. A DECENT SHOT OF COLD AIR
LOOKS TO ARRIVE IN THE WAKE OF THIS FEATURE... PERHAPS PRODUCING
TEMPERATURES THAT ARE ONLY 5-10 DEGREES ABOVE NORMAL. OTHERWISE...
IT LOOKS TO BE MAINLY DRY AS WE HEAD THROUGH THE UPCOMING WEEKEND
ALTHOUGH THERE ARE HINTS OF ANOTHER WEAK SHOT OF PCPN SLIPPING
THROUGH LATE SATURDAY INTO SUNDAY.
&&
.AVIATION.../00Z TAF ISSUANCE/
MAIN CONCERN THIS TAF PERIOD REVOLVES AROUND WINDS AND THE
POTENTIAL FOR WS OUT AHEAD OF ANOTHER STRONG COLD FRONT THAT WILL
BE SWINGING THROUGH THE MPX AREA TOMORROW. NAM/GFS SHOW 2K FT
WINDS INCREASING TO OVER 60 KTS AT ALL TERMINALS OUT AHEAD OF THIS
FRONT...SO INCLUDED WIND SHEAR AT ALL TERMINALS FOR A FEW HOURS
BEFORE WIND GUSTS START BETWEEN 13Z AND 16Z. DIRECTIONS WILL
CONTINUE TO BACK TOWARD THE SOUTH TONIGHT...THEN VEER BACK TO THE
SW AND EVEN WEST DURING THE DAY MONDAY. GIVEN SUCH STRONG WINDS AS
LOW AS THEY ARE PROGGED TO BE...COULD SEE GUSTS OVER
30KTS...ESPECIALLY DURING THE LATE MORNING. HOWEVER...WAA
OVERNIGHT LOOKS TO PUT A RATHER STRONG INVERSION IN PLACE AND BY
THE TIME MIXING STARTS GETTING UP AROUND 1K FT...THE CORE OF THE
STRONGEST WINDS WILL HAVE SHIFTED OFF TO THE EAST. ONCE
AGAIN...ATMO OUT AHEAD OF THE FRONT WILL BE RATHER DRY...SO NOT
EXPECTING ANYTHING MORE THAN VARYING AMOUNTS OF HIGH CLOUDS THIS
PERIOD...WITH NO INDICATIONS FOR LOW CLOUDS COMING UNTIL LATE
MONDAY NIGHT.
KMSP...WINDS WILL BE THE PRIMARY CONCERN THIS PERIOD. LAMP/MET
GUIDANCE BOTH SIMILAR WITH VEERING THE WINDS INTO THE BOTTOM END
OF THE 210-250 RANGE BY THE LATE MORNING...LASTING THROUGH THE
AFTERNOON. TO GO ALONG WITH THIS...SHOULD HAVE NO PROBLEM GETTING
FREQUENT GUSTS UP OVER 25KTS...WHICH COULD POSE SERIOUS ISSUES TO
USING THE PARALLEL RUNWAYS TOMORROW. TO GO ALONG WITH THIS...NAM
STILL SHOWS 3K FT WINDS PEAKING AT ABOUT 70 KTS AT 15Z. THOUGH
DIRECTIONAL SHEAR LOOKS TO BE NO MORE THAN 40 DEGS...THE NEARLY
60KTS OF SPEED INCREASE IN THE LOWEST 3K FT MORE THE WARRANTS THE
MENTION OF WS. COULD CONTINUE WITH WS ISSUES OUT TO 18Z...BUT
ENDED THE MENTION WITH THE EXPECTED INCREASE IN GUSTS AT 14Z.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY FROM MIDNIGHT TONIGHT TO NOON CST MONDAY FOR BROWN-
LAC QUI PARLE-REDWOOD-WATONWAN-YELLOW MEDICINE.
WI...NONE.
&&
$$
TRH/MPG
AREA FORECAST DISCUSSION...UDPATED
NWS JACKSON MS
945 AM CST SAT DEC 24 2011
...WET CHRISTMAS EXPECTED AND CONTINUING INTO MONDAY...
.UPDATE...SIGNIFICANT CHANGES REQUIRED TO THE FORECAST FOR TODAY.
MODELS ARE DOING THEIR TYPICAL POOR JOB OF HANDLING RESIDUAL
MOISTURE TRAPPED BELOW A BUILDING SUBSIDENCE INVERSION. IN SPITE OF
MODELS SHOWING LOW CLOUDS CLEARING OUT...REAL ATMOSPHERE SHOWING NO
SIGNS OF THIS HAPPENING ACROSS OUR FORECAST AREA. PUSH OF CLEARING
IN LOW CLOUDS INTO EXTREME NW ZONES HAS PRETTY WELL STOPPED AS AREA
PROFILERS AND VAD WIND PROFILES SHOW LOW LEVEL FLOW VEERING AROUND
TO MORE OF AN EASTERLY DIRECTION. LATEST RUC MODEL GUIDANCE SHOWS
FLOW CONTINUING TO VEER AROUND TO MORE OF ESE DIRECTION TODAY...AND
THIS WILL LIKELY RESULT IN LOW CLOUDS BEGINNING TO BUILD BACK TO
WNW. EVEN IF LOW CLOUDS DO MANAGE TO ERODE SOME...SATELLITE SHOWS
MID/HIGH CLOUDS RAPIDLY THICKENING ACROSS THE AREA IN BUILDING
ASCENT IN RIGHT ENTRANCE REGION OF INCREASING JETSTREAK FROM
MID-SOUTH INTO THE MID-ATLANTIC. HENCE HAVE INCREASED SKY COVER
GRIDS TO SHOW PRETTY MUCH OVERCAST CONDITIONS THROUGH THE DAY TODAY.
BEST CHANCE FOR SOME SUN WOULD APPEAR TO BE IN THE E/SE WHERE SOME
EROSION MAY OCCUR AS SOME DRIER AIR TRIES TO MIX IN FROM THE E.
GUIDANCE TEMPERATURES WERE BASED ON THE IDEA OF A FAIR AMOUNT OF
SUNSHINE TODAY...AND WITH MUCH LESS CHANCE OF THIS HAPPENING...
SIGNIFICANT REDUCTIONS IN MAX TEMPS ARE REQUIRED. AREA SOUNDINGS
SHOW THAT EVEN WITH DECENT SUNSHINE TEMPS WOULD LIKELY STRUGGLE TO
GET OUT OF THE 40S GIVEN SHALLOW RESIDUAL COLD AIR BELOW INCREASING
WARM AIR ADVECTION IN THE 850 TO 700 MB LAYER. HENCE HAVE KNOCKED
6-7 DEGS OFF OF PREVIOUS FORECAST MAXES FOR TODAY. IF LOW CLOUDS
HOLD TOUGH ALL DAY...EVEN THIS MAY NOT BE ENOUGH OF A REDUCTION AS
VERY LITTLE DIURNAL RISE IN TEMPS IS LIKELY WITH RECENT OBSERVATIONS
SHOWING TEMPS PRETTY MUCH HOLDING STEADY SO FAR.
FINALLY...REGIONAL RADAR SHOWS LARGE SHIELD OF RAIN CONTINUING TO
EXPAND OVER E TX AND STREAM RAPIDLY ENE TOWARD THE AREA.
EXTRAPOLATION BRINGS THIS ACTIVITY INTO FAR WESTERN ZONES BY MID
AFTERNOON. WHILE THERE WILL LIKELY BE SOME EROSION ALONG THE LEADING
EDGE...00Z ECMWF DID SUGGEST MEASURABLE QPF INTO WESTERN ZONES BY
00Z. HENCE HAVE UPPED POPS SLIGHTLY TO CHC CATEGORY IN FAR WESTERN
AREAS FOR MID/LATER AFTERNOON...AND EXPANDED SLIGHT CHANCE TO THE MS
RIVER.
LATEST MODEL GUIDANCE CONTINUES TO SUGGEST A VERY WET PERIOD COMING
UP EARLY NEXT WEEK. ECMWF/GFS/SREF ENSEMBLE GUIDANCE SUGGESTS THAT
HEAVIEST QPF MAY BE SHIFTED A BIT NW OF WHERE OPERATIONAL RUNS SHOW
IT...PERHAPS MORE OVER THE ARKLAMISS REGION. LATEST 12Z NAM IS
SHOWING SOME 5" TOTALS OVER THE DELTA BY THE TIME EVENT WINDS UP
LATE MONDAY. WILL OBVIOUSLY LOOK AT ALL OF THIS MORE CLOSELY AS 12Z
GUIDANCE CONTINUES TO ARRIVE. /08/
&&
.AVIATION...WIDESPREAD MVFR CEILINGS WITH STUBBORN IFR CLOUD LAYERS
CONTINUE ACROSS THE REGION AS LOW STRATUS CLOUDS HOVER AROUND 1K FT.
A SECOND LAYER OF INCREASING CLOUDS 9-11K FEET WILL MAKE IT
DIFFICULT FOR MUCH SUNSHINE TO BREAK THROUGH TO THESE LOW LEVEL
CLOUDS SO EXPECT ONLY SLIGHT IMPROVEMENTS THROUGH EARLY AFTERNOON
WITH MOST AREAS HOLDING BROKEN MVFR LAYERS 1-2K FEET AT BEST.
CONDITIONS WILL START DETERIORATING LATER THIS EVENING AS RAINS
OVERSPREAD THE REGION FROM SW TO NE...EMBEDDED TSRA SHOULD HOLD OFF
UNTIL AFTER 12Z SUNDAY MORNING BUT BEGIN INCREASING ESPECIALLY
SUNDAY NIGHT THROUGH MONDAY. WIDESPREAD IFR SHOULD PREVAIL AFTER 15Z
SUNDAY. SURFACE WINDS WILL PERSIST NELY AT 5 TO 10 KTS THROUGH THIS
FORECAST PERIOD. /40/
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...NONE.
LA...NONE.
AR...NONE.
&&
$$
08/40
AREA FORECAST DISCUSSION
NWS BUFFALO NY
339 PM EST SAT DEC 24 2011
.SYNOPSIS...
A WARM FRONT WILL LIFT NORTHEAST ACROSS THE REGION TONIGHT AND BRING
TEMPERATURES ABOVE AVERAGE ONCE AGAIN FOR CHRISTMAS DAY. A COLD
FRONT AND UPPER LEVEL DISTURBANCE WILL THEN SWEEP ACROSS THE REGION
CHRISTMAS AFTERNOON AND EVENING WITH A FEW RAIN SHOWERS CHANGING
OVER TO SNOW SHOWERS. DRY WEATHER WILL RETURN FOR MONDAY AS HIGH
PRESSURE BUILDS INTO THE OHIO VALLEY AND GREAT LAKES.
&&
.NEAR TERM /THROUGH SUNDAY/...
THROUGH THIS EVENING...LINGERING CLOUDS SOUTHEAST OF LAKE ONTARIO
WILL CONTINUE TO DISSIPATE AS WINDS SHIFT AND PUSH WHATS LEFT OF THE
CLOUDS NORTHWARD. MEANWHILE...AN A WARM FRONT WILL LIFT TOWARD THE
REGION FROM THE SOUTHWEST THIS EVENING...WITH AN ASSOCIATED AREA OF
CLOUDS FORECAST TO LIFT ACROSS SOUTHWESTERN NEW YORK THIS
EVENING...AND THE EASTERN LAKE ONTARIO REGION OVERNIGHT.
THIS FRONT IS RELATIVELY WEAK...WITH THE NAM/RGEM/GFS SHOWING NO
QPF...AND THE HRRR SHOWING ONLY A COUPLE HUNDREDTHS...MAINLY
CONFINED TO THE NORTH SHORES OF EACH OF THE LAKES. WITH NO
PRECIPITATION UPSTREAM...IT DOES NOT APPEAR THE FRONT ALONE HAS
AMPLE LIFT TO GENERATE ANY PRECIPITATION. WITH 850 MB TEMPERATURES
STILL -7 TO -10C AHEAD OF THE FRONT...IT MAY BE ABLE TO TAP INTO A
LITTLE LAKE INSTABILITY...HOWEVER THE S TO SSW FLOW SHOULD LARGELY
KEEP WHATEVER IS GENERATED TO THE NORTH AND WEST OF NEW YORK STATE.
WE MAY SEE A STRAY FLURRY ON THE NIAGARA FRONTIER...BUT AT THIS
POINT...IF THERE IS NOT ALREADY SNOW ON THE GROUND AT YOUR
LOCATION...IT IS VERY UNLIKELY THAT IT WILL BE A WHITE CHRISTMAS
MORNING.
OTHERWISE...THE OVERNIGHT PERIOD WILL BE SEASONABLY COOL.
TEMPERATURES WILL PROBABLY BOTTOM OUT DURING THE EVENING
HOURS...THEN START TO RAISE AS WINDS INCREASE LATE TONIGHT...AND AS
WARMER AIR BUILDS IN BEHIND THE FRONT. LOWS WILL BE COLDEST EAST OF
LAKE ONTARIO...WHERE A SNOW PACK IS LARGELY IN PLACE...AND WHERE IT
WILL BE CLEAR AND CALM FOR PART OF THE EVENING.
CHRISTMAS DAY SHOULD START OFF DRY...BUT WITH FAIRLY WINDY
CONDITIONS. THE NAM/GFS BOTH ARE FORECASTING A 40 KT LOW LEVEL JET
DOWN TO 2000 FEET ON SUNDAY. WHILE THIS SHOULD NOT MIX
COMPLETELY...EXPECT SOME GUSTS IN THE 35 MPH RANGE INLAND...WITH
PEAK GUSTS AROUND 40 MPH ALONG THE NIAGARA FRONTIER...WHERE
FUNNELING...AND RELATIVELY WARMER TEMPERATURES ON LAKE ERIE WILL
AID MIXING. MEANWHILE...TEMPERATURES WILL BE COOL...BUT ABOVE NORMAL
FOR THE DATE...WITH HIGHS IN THE UPPER 30S TO AROUND 40 ACROSS
WESTERN NEW YORK.
A FAIRLY VIGOROUS SHORTWAVE WILL APPROACH FROM THE UPPER LAKES
SUNDAY AFTERNOON. WHILE THIS WILL LIKELY SPARK SOME SHOWERS...THESE
SHOULD LARGELY HOLD OFF UNTIL SUNSET OR SHORTLY THEREAFTER.
CONSENSUS QPF AMONG THE NAM/RGEM/GFS ALL PRETTY MUCH FOCUS ON THE
21Z TO 03Z SUNDAY TIMEFRAME. WHILE QPFS ARE GENERALLY A TENTH OF AN
INCH OR LESS...THERE IS GOOD MODEL CONSISTENCY. NAM BUFKIT FOR
JAMESTOWN SHOWS A FEW HOURS OF A THIN AND NARROW CAPE...SUGGESTING A
PERIOD OF LAKE ENHANCED PRECIPITATION WITH THE PASSAGE OF THE
SHORTWAVE.
ALONG THE I-90 CORRIDOR FROM BUFFALO TO ROCHESTER...EXPECT SCATTERED
RAIN OR SNOW SHOWERS TOWARD SUNSET...WITH LITTLE IF ANY SNOW
ACCUMULATION. EAST OF THE LAKES...BOTH IN WESTERN PORTIONS OF THE
SOUTHERN TIER...AND THE EASTERN LAKE ONTARIO REGION...PRECIPITATION
WILL LIKELY START AS A MIX TOWARD SUNSET...BUT SHOULD TREND TOWARD SNOW
AFTER SUNSET. THERE MAY BE SOME MODEST ACCUMULATIONS IN THESE
LOCATIONS.
&&
.SHORT TERM /SUNDAY NIGHT THROUGH TUESDAY/...
UPPER TROUGH AND COLD FRONT DROPS SOUTH ACROSS THE REGION SUNDAY
NIGHT WITH PRECIP CHANGING OVER TO SNOW SHOWERS. BREEZY TO WINDY
CONDITIONS WILL ACCOMPANY THE COLD FRONT DURING THE EVENING AND
EARLY NIGHT. EXPECT SOUTHWEST WIND AVERAGING 20 TO 25 MPH GUSTS TO
30..SHIFTING TO WESTERLY. THE RAIN SHOWERS WILL TRANSITION TO SNOW
SHOWERS AS THE WINDS SHIFT. SNOW ACCUMS DURING THE NIGHT WILL BE
ONLY IN THE FRACTIONS OF AN INCH FOR MOST LOCATIONS...THE TUG HILL
PLATEAU MAY SEE AS MUCH AS 2 INCHES WITH THE OROGRAPHIC ENHANCEMENT
OF LIFT AND COLDER 850MB TEMPS NEAR -8C.
HIGH PRESSURE AND UPPER RIDGING DOMINATE MONDAY AND MONDAY NIGHT.
THERE WILL BE A RETURN OF SUNSHINE BUT DAYTIME TEMPS WILL BE LIMITED
TO THE 30S...MID 20S FOR THE EASTERN LAKE ONTARIO REGION.
A DEEPENING TROUGH ACROSS THE CONTINENT`S MIDSECTION WILL TAP AN
INCREASINGLY MOIST SOUTHERLY FLOW WHICH WILL BRING CLOUDS AND WARMER
CONDITIONS TO THE REGION ON TUESDAY. TEMPS WILL BE ON THE RISE
THROUGH MONDAY NIGHT...TOPPING OUT IN THE UPPER 30S TO LOW 40S ON
TUESDAY. WITH THE STRONG WARM ADVECTION LATE MONDAY NIGHT THROUGH
THE DAY ON TUESDAY...EXPECT THE PRECIP TO BE AS RAIN DURING THE
DAY...TRANSITIONING TO A RAIN/SNOW MIX LATE...THEN TO ALL SNOW TUES
EVENING.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
TIMING DIFFERENCES BETWEEN GFS AND ECMWF BECOME SIGNIFICANT ON
TUESDAY NIGHT. GFS IS SLOWER IN LIFTING SURFACE AND CLOSED UPPER LOW
FROM THE MIDDLE MISSISSIPPI VALLEY TUESDAY MORNING TO THE CENTRAL
APPALACHIANS TUESDAY EVENING. ECMWF IS FASTER AND FARTHER EAST WITH
THE SURFACE LOW AND HAS THE ADDITIONAL FEATURE OF PHASING THE
NORTHERN BRANCH TROUGH ACROSS THE GREAT LAKES WITH THE MORE OPEN
SOUTHERN BRANCH WAVE. THIS ALLOWS A SOUTHWARD DRAW OF MUCH COLDER
AIR TO THE WEST OF THE SURFACE LOW.
WILL CONCUR WITH THE EXTENDED HPC DISCUSSION AND CONTINUE TO USE THE
ECMWF FOR TUESDAY NIGHT`S PATTERN. THE WET WEATHER OF LATE TUESDAY
WILL CHANGE OVER TO SNOW TUESDAY NIGHT AS 850MB TEMPS RANGING FROM
-2C TO -5C ARE ACROSS THE REGION...WITH MUCH COLDER AIR ON TAP. WILL
HAVE CHANCE POPS FOR LIGHT SNOW...AND DO EXPECT TO SEE AN
ACCUMULATION WITH THIS SYSTEM.
850MB TEMPS DROP TO -14C AS PER ECMWF...THUS WILL KEEP LIGHT SNOW IN
LAKE EFFECT ACROSS MUCH OF THE FORECAST AREA. UPPER MOISTURE SHOULD
LIMIT THE INTENSITY OF LAKE SNOW...BUT THIS WILL BEAR WATCHING OVER
THE NEXT SEVERAL MODEL RUNS TO SEE IF THE -14C TEMPS PERSIST. HIGH
PRESSURE ACROSS THE AREA ON THURSDAY WILL BE FOLLOWED BY A WARM
FRONT THURSDAY NIGHT WITH SCATTERED SNOW SHOWERS FRIDAY AND
SATURDAY. ECMWF AND GFS NOT EXACTLY IN AGREEMENT BUT CLOSE ENOUGH TO
CARRY LOW CHANCE POPS FOR THE END OF THE PERIOD.
TEMPS WILL CLOSE TO SEASONAL NORMS DURING MIDWEEK...THEN A SLIGHT
WARMING TOWARD THE END OF THE WEEK.
&&
.AVIATION /21Z SATURDAY THROUGH THURSDAY/...
THROUGH 20Z...EXPECT LARGELY VFR CONDITIONS THROUGH THE TAF PERIOD.
THERE MAY BE SOME LINGERING MVFR CIGS NEAR JHW. AFTER THIS...AN AREA
OF WARM AIR ADVECTION IN THE LOWER AND MID LEVELS WILL RESULT IN A
BAND OF CLOUDS WILL WILL LIFT ACROSS THE REGION FROM SW-NE THIS
EVENING AND OVERNIGHT. THESE WILL LIKELY BE ABOVE 3000 FT.
OTHERWISE...WINDS WILL INCREASE MARKEDLY SUNDAY MORNING...ESPECIALLY
AT BUF AND IAG...WHERE GUSTS TO 35 KTS ARE EXPECTED. MODEST WIND
SHEAR WILL DEVELOP LATE TONIGHT...BUT WITH A WINDS ALOFT ONLY IN THE
30 TO 35 KT RANGE JUST PRIOR TO MIXING...SO SHEAR MAY FALL SHY OF
CRITERIA FOR INCLUSION IN THE TAFS.
AN APPROACHING SHORTWAVE WILL SPARK RAIN AND SNOW SHOWERS LATE
SUNDAY AFTERNOON...POSSIBLY LOWERING CONDITIONS TO MVFR OR LOWER
TOWARD 00Z MONDAY.
OUTLOOK...
SUNDAY NIGHT...MVFR/IFR WITH SNOW SHOWERS...MOST WIDESPREAD EAST OF
THE LAKES.
MONDAY...VFR/MVFR WITH WITH MORNING SNOW SHOWERS...THEN VFR.
TUESDAY AND TUESDAY NIGHT...MVFR IN RAIN OR SNOW SHOWERS.
WEDNESDAY...MAINLY VFR.
&&
.MARINE...
A WARM FRONT WILL CROSS THE LOWER LAKES FROM SOUTHWEST TO NORTHEAST
OVERNIGHT AND THE PRESSURE GRADIENT QUICKLY INCREASES. WINDS ALOFT
WILL BE ABOUT 40 KTS AT 2000 FT. WHILE A WARM AIR ADVECTION
PATTERN...THE AIR IN PLACE IS QUITE COOL...GENERALLY IN THE 30S.
THIS SHOULD ALLOW FAIRLY GOOD MIXING...WITH THE LAKE TEMPERATURES
RUNNING IN THE LOWER 40S. EXPECT WINDS TO REALLY PICK UP SUNDAY
MORNING...WITH SUSTAINED WINDS EXPECTED TO PEAK NEAR 30 KTS DURING
THE DAY SUNDAY. EXPECT A FEW GALE FORCE GUSTS...BUT BY LARGE EXPECT
CONDITIONS TO PEAK AT HIGH END SMALL CRAFT...BEFORE DIMINISHING
SUNDAY NIGHT AS HIGH PRESSURE BUILDS IN.
HIGH PRESSURE WILL BRIEFLY BUILD ACROSS ON TUESDAY...WITH AN
INCREASING NE FLOW TUESDAY NIGHT AND WEDNESDAY AS LOW PRESSURE
PASSES TO THE SOUTH.
&&
.CLIMATE...
WITH NO MEASURABLE SNOW EXPECTED OVERNIGHT...BOTH BUFFALO AND
ROCHESTER APPEAR VIRTUALLY ASSURED OF A GREEN CHRISTMAS THIS YEAR.
THE ONLY AREAS THAT MAY STILL HAVE WHITE GROUND CHRISTMAS MORNING
ARE THE HILLTOPS OF THE SOUTHERN TIER AND THE HIGHER TERRAIN EAST
OF LAKE ONTARIO...BUT EVEN IN THESE AREAS JUST A MINOR COATING MAY
REMAIN.
THE WINTER OF 2011-12 HAS STARTED AT A RECORD SLOW PACE IN THE
SNOWFALL CATEGORY ACROSS WESTERN AND CENTRAL NEW YORK. THROUGH
DECEMBER 23RD...THE CURRENT SNOW THIS SEASON OF 3.0 INCHES
(BUFFALO) AND 2.5 INCHES (ROCHESTER) ARE WELL BELOW NORMAL THUS
FAR. THERE HAVE BEEN SEVERAL YEARS THAT HAVE HAD SIMILAR STARTS
THOUGH. BELOW IS A LIST OF THE LEAST AMOUNT OF SNOW IN BOTH CITIES
IN PREVIOUS YEARS ON RECORD...MEASURED AT THE RESPECTIVE
AIRPORTS...THROUGH AND INCLUDING CHRISTMAS EVE.
BUFFALO
1 3.0 2011
2 3.1 1998
3 3.3 1931
4 3.6 1896
5 4.3 1918
...
10 6.5 1888
...
15 7.8 1891
***NORMAL THROUGH DECEMBER 24TH 29.1***
ROCHESTER
1 2.5 2011
2 2.6 1939
3 3.7 2001
4 3.8 1877
5 4.2 2006
...
10 6.2 1998
...
15 7.8 1940
***NORMAL THROUGH DECEMBER 24TH 23.5***
SNOWFALL RECORDS GO BACK TO THE WINTER OF 1884-85.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 9 AM SUNDAY TO 4 AM EST MONDAY FOR
LEZ020.
SMALL CRAFT ADVISORY FROM 1 AM SUNDAY TO 4 AM EST MONDAY
FOR LEZ040-041.
SMALL CRAFT ADVISORY FROM 9 AM SUNDAY TO 4 AM EST
MONDAY FOR LOZ030.
SMALL CRAFT ADVISORY FROM 7 AM SUNDAY TO 4 AM EST MONDAY
FOR LOZ042>044.
SMALL CRAFT ADVISORY FROM 4 AM SUNDAY TO 4 AM EST MONDAY
FOR LOZ045.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL/WCH
CLIMATE...THOMAS/HITCHCOCK/JJR
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
338 AM EST SAT DEC 24 2011
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL
CLOUDS TO THE AREA MOST OF THIS HOLIDAY WEEKEND BUT MAINLY DRY
WEATHER IS EXPECTED. HOWEVER...A COLD FRONT WILL CROSS THE AREA
CHRISTMAS NIGHT WITH A BETTER CHANCE FOR SNOW SHOWERS AND POSSIBLY
MINOR SNOW ACCUMULATIONS. BY MONDAY AFTERNOON...HIGH PRESSURE WILL
BRING A RETURN TO PARTLY SUNNY SKIES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1230 AM UPDATE...AN AREA OF VERY LIGHT SNOW OR FLURRIES CONTINUES
ACROSS CNY. MADE MINOR TWEAKS TO THE CURRENT POPS GRIDS OTHERWISE
WE ARE IN GOOD SHAPE. THIS AREA OF SNOW IS EXPECTED TO CONTINUE
SHIFTING SOUTH WHILE WEAKENING. WITH THAT SAID DUE TO THE COLD
AIR-MASS IN PLACE...FLURRIES ARE EXPECTED TO LAST THROUGH ABOUT
DAYBREAK ACROSS THE SOUTHERN TIER OF NY. THE PREVIOUS AFD IS BELOW...
10 PM UPDATE...RADAR SHOWS THAT REMAINING SNOW SHOWERS
ARE VERY LIGHT BECAUSE OF THE VERY DRY AIR MASS ADVECTING INTO THE
REGION. HOWEVER...ALBEIT LIMITED...MOISTURE CONTINUES TO FEED OFF
OF LAKE ONTARIO LATE THIS EVENING. 850MB TEMPERATURES IN THE
NORTHWEST HALF OF THE AREA ARE MINUS-10 TO MINUS-12 CELSIUS...ONE
OF THE COLDER AIR MASSES WE HAVE HAD THUS FAR THIS SEASON. SO
DESPITE THE SYNOPTICALLY DRY AIR...THERE IS ENOUGH DELTA-T BETWEEN
LAKE AND 850MB TO INITIATE CONTINUED LAKE EFFECT SNOW
SHOWERS/FLURRIES OVERNIGHT. HIGH RESOLUTION MODELS...VIA QPF FROM
HRRR OR LOW LEVEL RH FIELDS OF THE RUC AND WRFNMM...SUGGEST NARROW
BANDS OF LIGHT SNOW SHOWERS AND FLURRIES WILL SHIFT SOUTHWARD TO
INCLUDE MORE OF THE SOUTHERN TIER AS THE FLOW CONTINUES TO VEER.
IN THE END THOUGH...DRY AIR MASS WINS AND WHAT IS LEFT OF FLURRIES
WILL DISSIPATE NOT LONG AFTER DAWN. VAST MAJORITY OF THE AFFECTED
AREA WILL HAVE LESS THAN AN INCH OF FLUFFY ACCUMULATION.
ALSO...AN ADVANCING SHORT WAVE FROM THE UPPER GREAT LAKES LATE TONIGHT
THROUGH EARLY SATURDAY WILL PRODUCE A PERIOD OF MID LEVEL CLOUDS.
LOWS TONIGHT WILL RANGE FROM THE TEENS TO AROUND 20.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY NIGHT/...
SATURDAY THROUGH SUNDAY...SFC HIGH PRES OVER THE REGION MOVES TO
THE EAST COAST BY CHRISTMAS PROVIDING A SLIGHTLY MODIFYING FLOW.
MAXES ON SATURDAY WILL RANGE FROM THE UPPER 20S TO THE 30S WITH
LOWS SATURDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. ON CHRISTMAS,
HIGH PRES ALONG THE COAST AND AN APPROACHING TROF FROM THE UPPER
GREAT LAKES WILL PROVIDE A SOUTHWEST FLOW OF MILDER AIR WITH MAXES
IN THE MID 30S TO AROUND 40. TOWARD EVENING THE APPROACHING FRONT
MAY BRING SOME RAIN/SNOW SHOWERS TO THE WRN/NRN PTN OF CWA.
SUNDAY NIGHT...SFC TROF MOVES THROUGH WITH BETTER MOISTURE AND
FORCING THAN PREVIOUS SFC TROFS. WENT WITH LIKELY POPS NRN CWA
AND HIGH CHC CENTRAL AND LOW CHC FAR SE. AVAILABLE MOISTURE, LOW
LEVEL INSTABILITY AND FETCH INDICATES POSSIBLY AND INCH OR TWO OF
SNOW DOWNWIND OF LAKE ONTARIO UNDER 300 FLOW. T85 TEMPS ARE VERY
MARGINAL BUT A BRIEF LAKE RESPONSE IS POSSIBLE.
MONDAY...SFC RIDGING QUICKLY BUILDS IN BEHIND TROF ENDING ANY POST
FRONTAL SNOW SHOWERS BY MID MORNING WITH SKIES BECOMING PARTLY
SUNNY. TEMPS WILL RANGE IN THE 30S.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
330 AM UPDATE...
FAST FLOW AND LOW UPPER LEVEL AMPLITUDE WILL KEEP IT ACTIVE AND
WET...BUT AGAIN WITH NO SIGNIFICANT SNOW EXPECTED. FOLLOWED HPC
GUIDANCE...WHICH FAVORS THE EURO AND CANADIAN. GFS LOOKS TOO FAST
AGAIN. TUESDAY A STORM MOVES NE THROUGH US WITH MIXED PRECIP. THE
SFC LOW QUICKLY INTENSIFIES IN EASTERN NEW ENGLAND AND EASTERN
CANADA TUESDAY NIGHT AND WED. THIS WILL PULL IN SOME COLDER AIR SO
CHANGE TO ALL SNOW WITH LAKE EFFECT. THIS DOES NOT LAST LONG WITH
HIGH PRESSURE THURSDAY AND FRIDAY. MILD AIR AGAIN WITH A WEAK
UPPER LEVEL RIDGE. SATURDAY WILL BE THE NEXT COLD FRONT BUT ONCE
AGAIN MIXED RAIN AND SNOW.
PREVIOUS DISCUSSION...
MODELS ARE IN FAIR AGREEMENT TODAY WITH THE EXTENDED FORECAST.
HOWEVER, THEY ARE FLIPPING SOME FROM YESTERDAYS RUNS. AS THOUGH
PREVIOUSLY, MONDAY NIGHT WILL SEE HIGH PRESSURE BEING PUSHED OFF
TO THE EAST AS TWO LOW PRESSURE SYSTEMS APPROACH THE CWA, ONE FROM
THE NW AND ONE FROM THE SOUTH. YESTERDAYS RUNS HAD THE SOUTHERN
SYSTEM MORE TO THE SOUTH, AND THE NORTHERN SYSTEM COMING IN DRY.
NOW THE MODELS HAVE MOISTENED UP THINGS FOR TUESDAY. THEY NOW
BRING IN SOME RAIN AND SNOW INTO THE CWA FOR TUESDAY. QPF IS NOT
VERY HIGH, WITH ONLY ONE OR TWO TENTHS OF AN INCH OF LIQUID. SO,
WILL KEEP A MENTION OF PRECIP IN THE FORECAST FOR TUESDAY AND
TUESDAY NIGHT.
FOR WEDNESDAY, THERE COULD BE SOME WEAK LAKE RESPONSE TO THE FRONT
PASSING, BUT IT SHOULD BE VERY LIGHT, IF ANY AT ALL. OTHERWISE,
THE CWA WILL SEE QUIET WEATHER AS HIGH PRESSURE BUILDS BACK IN FOR
WEDNESDAY NIGHT THROUGH THURSDAY. BY THURSDAY AFTERNOON, MODELS
INDICATE THERE WILL BE ANOTHER LOW PRESSURE SYSTEM MOVING IN FROM
THE NORTHERN PLAINS. THIS WILL BRING A WEAK WARM FRONT INTO THE
AREA FOR THURSDAY NIGHT. THIS WILL BRING YET ANOTHER CHANCE FOR
PRECIPITATION. INDICATIONS ARE IT COULD BE ALL SNOW. HOWEVER, IT
IS WAY OUT IN THE FORECAST AND CONFIDENCE IS PRETTY LOW IN THE
MODELS AT THIS TIME.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
1230 AM UPDATE...
NORTH NORTHWEST FLOW OFF OF LAKE ONTARIO WILL KEEP SOME MOISTURE
TRAPPED UNDER INVERSION FOR MAINLY MVFR CIGS THROUGH AROUND 9Z
BEFORE A UPPER LEVEL DISTURBANCE SHIFTS THE WIND AND HIGH PRESSURE
BUILDS IN TOWARD 12Z. SYR AND ITH COULD HAVE MVFR IN LIGHT SNOW
SHOWERS THE FIRST FEW HOURS.
FOR THE DAYTIME HOURS SKIES WILL CLEAR EXCEPT MAYBE CLOSE TO LAKE
ONTARIO AND LAKE CAYUGA FOR SCT LOW CLOUDS.
NW TO N WINDS AT 5 KTS SHIFTING TO NW AROUND 12Z. THIS EVENING SE
WINDS AT 5 KTS.
.OUTLOOK...
SAT NGT/SUN...VFR.
SUN NGT/MON MRG...MVFR POSSIBLE IN LIGHT SNOW.
LATER MONDAY INTO MON AFTN/NGT...VFR.
TUE...MVFR IN RAIN AND SNOW SHOWERS.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...HEDEN/MDP/RRM
SHORT TERM...RRM
LONG TERM...SLI/TAC
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1246 AM EST SAT DEC 24 2011
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL
CLOUDS TO THE AREA MOST OF THIS HOLIDAY WEEKEND BUT MAINLY DRY
WEATHER IS EXPECTED. HOWEVER...A COLD FRONT WILL CROSS THE AREA
CHRISTMAS NIGHT WITH A BETTER CHANCE FOR SNOW SHOWERS AND POSSIBLY
MINOR SNOW ACCUMULATIONS. BY MONDAY AFTERNOON...HIGH PRESSURE WILL
BRING A RETURN TO PARTLY SUNNY SKIES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1230 AM UPDATE...AN AREA OF VERY LIGHT SNOW OR FLURRIES CONTINUES
ACROSS CNY. MADE MINOR TWEAKS TO THE CURRENT POPS GRIDS OTHERWISE
WE ARE IN GOOD SHAPE. THIS AREA OF SNOW IS EXPECTED TO CONTINUE
SHIFTING SOUTH WHILE WEAKENING. WITH THAT SAID DUE TO THE COLD
AIR-MASS IN PLACE...FLURRIES ARE EXPECTED TO LAST THROUGH ABOUT
DAYBREAK ACROSS THE SOUTHERN TIER OF NY. THE PREVIOUS AFD IS BELOW...
10 PM UPDATE...RADAR SHOWS THAT REMAINING SNOW SHOWERS
ARE VERY LIGHT BECAUSE OF THE VERY DRY AIR MASS ADVECTING INTO THE
REGION. HOWEVER...ALBEIT LIMITED...MOISTURE CONTINUES TO FEED OFF
OF LAKE ONTARIO LATE THIS EVENING. 850MB TEMPERATURES IN THE
NORTHWEST HALF OF THE AREA ARE MINUS-10 TO MINUS-12 CELSIUS...ONE
OF THE COLDER AIR MASSES WE HAVE HAD THUS FAR THIS SEASON. SO
DESPITE THE SYNOPTICALLY DRY AIR...THERE IS ENOUGH DELTA-T BETWEEN
LAKE AND 850MB TO INITIATE CONTINUED LAKE EFFECT SNOW
SHOWERS/FLURRIES OVERNIGHT. HIGH RESOLUTION MODELS...VIA QPF FROM
HRRR OR LOW LEVEL RH FIELDS OF THE RUC AND WRFNMM...SUGGEST NARROW
BANDS OF LIGHT SNOW SHOWERS AND FLURRIES WILL SHIFT SOUTHWARD TO
INCLUDE MORE OF THE SOUTHERN TIER AS THE FLOW CONTINUES TO VEER.
IN THE END THOUGH...DRY AIR MASS WINS AND WHAT IS LEFT OF FLURRIES
WILL DISSIPATE NOT LONG AFTER DAWN. VAST MAJORITY OF THE AFFECTED
AREA WILL HAVE LESS THAN AN INCH OF FLUFFY ACCUMULATION.
ALSO...AN ADVANCING SHORT WAVE FROM THE UPPER GREAT LAKES LATE TONIGHT
THROUGH EARLY SATURDAY WILL PRODUCE A PERIOD OF MID LEVEL CLOUDS.
LOWS TONIGHT WILL RANGE FROM THE TEENS TO AROUND 20.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY THROUGH SUNDAY...SFC HIGH PRES OVER THE REGION MOVES TO
THE EAST COAST BY CHRISTMAS PROVIDING A SLIGHTLY MODIFYING FLOW.
MAXES ON SATURDAY WILL RANGE FROM THE UPPER 20S TO THE 30S WITH
LOWS SATURDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. ON CHRISTMAS,
HIGH PRES ALONG THE COAST AND AN APPROACHING TROF FROM THE UPPER
GREAT LAKES WILL PROVIDE A SOUTHWEST FLOW OF MILDER AIR WITH MAXES
IN THE MID 30S TO AROUND 40. TOWARD EVENING THE APPROACHING FRONT
MAY BRING SOME RAIN/SNOW SHOWERS TO THE WRN/NRN PTN OF CWA.
SUNDAY NIGHT...SFC TROF MOVES THROUGH WITH BETTER MOISTURE AND
FORCING THAN PREVIOUS SFC TROFS. WENT WITH LIKELY POPS NRN CWA
AND HIGH CHC CENTRAL AND LOW CHC FAR SE. AVAILABLE MOISTURE, LOW
LEVEL INSTABILITY AND FETCH INDICATES POSSIBLY AND INCH OR TWO OF
SNOW DOWNWIND OF LAKE ONTARIO UNDER 300 FLOW. T85 TEMPS ARE VERY
MARGINAL BUT A BRIEF LAKE RESPONSE IS POSSIBLE.
MONDAY...SFC RIDGING QUICKLY BUILDS IN BEHIND TROF ENDING ANY POST
FRONTAL SNOW SHOWERS BY MID MORNING WITH SKIES BECOMING PARTLY
SUNNY. TEMPS WILL RANGE IN THE 30S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN FAIR AGREEMENT TODAY WITH THE EXTENDED FORECAST.
HOWEVER, THEY ARE FLIPPING SOME FROM YESTERDAYS RUNS. AS THOUGH
PREVIOUSLY, MONDAY NIGHT WILL SEE HIGH PRESSURE BEING PUSHED OFF
TO THE EAST AS TWO LOW PRESSURE SYSTEMS APPROACH THE CWA, ONE FROM
THE NW AND ONE FROM THE SOUTH. YESTERDAYS RUNS HAD THE SOUTHERN
SYSTEM MORE TO THE SOUTH, AND THE NORTHERN SYSTEM COMING IN DRY.
NOW THE MODELS HAVE MOISTENED UP THINGS FOR TUESDAY. THEY NOW
BRING IN SOME RAIN AND SNOW INTO THE CWA FOR TUESDAY. QPF IS NOT
VERY HIGH, WITH ONLY ONE OR TWO TENTHS OF AN INCH OF LIQUID. SO,
WILL KEEP A MENTION OF PRECIP IN THE FORECAST FOR TUESDAY AND
TUESDAY NIGHT.
FOR WEDNESDAY, THERE COULD BE SOME WEAK LAKE RESPONSE TO THE FRONT
PASSING, BUT IT SHOULD BE VERY LIGHT, IF ANY AT ALL. OTHERWISE,
THE CWA WILL SEE QUIET WEATHER AS HIGH PRESSURE BUILDS BACK IN FOR
WEDNESDAY NIGHT THROUGH THURSDAY. BY THURSDAY AFTERNOON, MODELS
INDICATE THERE WILL BE ANOTHER LOW PRESSURE SYSTEM MOVING IN FROM
THE NORTHERN PLAINS. THIS WILL BRING A WEAK WARM FRONT INTO THE
AREA FOR THURSDAY NIGHT. THIS WILL BRING YET ANOTHER CHANCE FOR
PRECIPITATION. INDICATIONS ARE IT COULD BE ALL SNOW. HOWEVER, IT
IS WAY OUT IN THE FORECAST AND CONFIDENCE IS PRETTY LOW IN THE
MODELS AT THIS TIME.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
1230 AM UPDATE...
NORTH NORTHWEST FLOW OFF OF LAKE ONTARIO WILL KEEP SOME MOISTURE
TRAPPED UNDER INVERSION FOR MAINLY MVFR CIGS THROUGH AROUND 9Z
BEFORE A UPPER LEVEL DISTURBANCE SHIFTS THE WIND AND HIGH PRESSURE
BUILDS IN TOWARD 12Z. SYR AND ITH COULD HAVE MVFR IN LIGHT SNOW
SHOWERS THE FIRST FEW HOURS.
FOR THE DAYTIME HOURS SKIES WILL CLEAR EXCEPT MAYBE CLOSE TO LAKE
ONTARIO AND LAKE CAYUGA FOR SCT LOW CLOUDS.
NW TO N WINDS AT 5 KTS SHIFTING TO NW AROUND 12Z. THIS EVENING SE
WINDS AT 5 KTS.
.OUTLOOK...
SAT NGT/SUN...VFR.
SUN NGT/MON MRG...MVFR POSSIBLE IN LIGHT SNOW.
LATER MONDAY INTO MON AFTN/NGT...VFR.
TUE...MVFR IN RAIN AND SNOW SHOWERS.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...HEDEN/MDP/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...TAC
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1231 AM EST SAT DEC 24 2011
.SYNOPSIS...
A SERIES OF WEAK UPPER LEVEL DISTURBANCES WILL BRING OCCASIONAL
CLOUDS TO THE AREA MOST OF THIS HOLIDAY WEEKEND BUT MAINLY DRY
WEATHER IS EXPECTED. HOWEVER...A COLD FRONT WILL CROSS THE AREA
CHRISTMAS NIGHT WITH A BETTER CHANCE FOR SNOW SHOWERS AND POSSIBLY
MINOR SNOW ACCUMULATIONS. BY MONDAY AFTERNOON...HIGH PRESSURE WILL
BRING A RETURN TO PARTLY SUNNY SKIES.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
1230 AM UPDATE...AN AREA OF VERY LIGHT SNOW OR FLURRIES CONTINUES
ACROSS CNY. MADE MINOR TWEAKS TO THE CURRENT POPS GRIDS OTHERWISE
WE ARE IN GOOD SHAPE. THIS AREA OF SNOW IS EXPECTED TO CONTINUE
SHIFTING SOUTH WHILE WEAKENING. WITH THAT SAID DUE TO THE COLD
AIR-MASS IN PLACE...FLURRIES ARE EXPECTED TO LAST THROUGH ABOUT
DAYBREAK ACROSS THE SOUTHERN TIER OF NY. THE PREVIOUS AFD IS BELOW...
10 PM UPDATE...RADAR SHOWS THAT REMAINING SNOW SHOWERS
ARE VERY LIGHT BECAUSE OF THE VERY DRY AIR MASS ADVECTING INTO THE
REGION. HOWEVER...ALBEIT LIMITED...MOISTURE CONTINUES TO FEED OFF
OF LAKE ONTARIO LATE THIS EVENING. 850MB TEMPERATURES IN THE
NORTHWEST HALF OF THE AREA ARE MINUS-10 TO MINUS-12 CELSIUS...ONE
OF THE COLDER AIR MASSES WE HAVE HAD THUS FAR THIS SEASON. SO
DESPITE THE SYNOPTICALLY DRY AIR...THERE IS ENOUGH DELTA-T BETWEEN
LAKE AND 850MB TO INITIATE CONTINUED LAKE EFFECT SNOW
SHOWERS/FLURRIES OVERNIGHT. HIGH RESOLUTION MODELS...VIA QPF FROM
HRRR OR LOW LEVEL RH FIELDS OF THE RUC AND WRFNMM...SUGGEST NARROW
BANDS OF LIGHT SNOW SHOWERS AND FLURRIES WILL SHIFT SOUTHWARD TO
INCLUDE MORE OF THE SOUTHERN TIER AS THE FLOW CONTINUES TO VEER.
IN THE END THOUGH...DRY AIR MASS WINS AND WHAT IS LEFT OF FLURRIES
WILL DISSIPATE NOT LONG AFTER DAWN. VAST MAJORITY OF THE AFFECTED
AREA WILL HAVE LESS THAN AN INCH OF FLUFFY ACCUMULATION.
ALSO...AN ADVANCING SHORT WAVE FROM THE UPPER GREAT LAKES LATE TONIGHT
THROUGH EARLY SATURDAY WILL PRODUCE A PERIOD OF MID LEVEL CLOUDS.
LOWS TONIGHT WILL RANGE FROM THE TEENS TO AROUND 20.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH MONDAY/...
SATURDAY THROUGH SUNDAY...SFC HIGH PRES OVER THE REGION MOVES TO
THE EAST COAST BY CHRISTMAS PROVIDING A SLIGHTLY MODIFYING FLOW.
MAXES ON SATURDAY WILL RANGE FROM THE UPPER 20S TO THE 30S WITH
LOWS SATURDAY NIGHT IN THE UPPER TEENS TO LOWER 20S. ON CHRISTMAS,
HIGH PRES ALONG THE COAST AND AN APPROACHING TROF FROM THE UPPER
GREAT LAKES WILL PROVIDE A SOUTHWEST FLOW OF MILDER AIR WITH MAXES
IN THE MID 30S TO AROUND 40. TOWARD EVENING THE APPROACHING FRONT
MAY BRING SOME RAIN/SNOW SHOWERS TO THE WRN/NRN PTN OF CWA.
SUNDAY NIGHT...SFC TROF MOVES THROUGH WITH BETTER MOISTURE AND
FORCING THAN PREVIOUS SFC TROFS. WENT WITH LIKELY POPS NRN CWA
AND HIGH CHC CENTRAL AND LOW CHC FAR SE. AVAILABLE MOISTURE, LOW
LEVEL INSTABILITY AND FETCH INDICATES POSSIBLY AND INCH OR TWO OF
SNOW DOWNWIND OF LAKE ONTARIO UNDER 300 FLOW. T85 TEMPS ARE VERY
MARGINAL BUT A BRIEF LAKE RESPONSE IS POSSIBLE.
MONDAY...SFC RIDGING QUICKLY BUILDS IN BEHIND TROF ENDING ANY POST
FRONTAL SNOW SHOWERS BY MID MORNING WITH SKIES BECOMING PARTLY
SUNNY. TEMPS WILL RANGE IN THE 30S.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
MODELS ARE IN FAIR AGREEMENT TODAY WITH THE EXTENDED FORECAST.
HOWEVER, THEY ARE FLIPPING SOME FROM YESTERDAYS RUNS. AS THOUGH
PREVIOUSLY, MONDAY NIGHT WILL SEE HIGH PRESSURE BEING PUSHED OFF
TO THE EAST AS TWO LOW PRESSURE SYSTEMS APPROACH THE CWA, ONE FROM
THE NW AND ONE FROM THE SOUTH. YESTERDAYS RUNS HAD THE SOUTHERN
SYSTEM MORE TO THE SOUTH, AND THE NORTHERN SYSTEM COMING IN DRY.
NOW THE MODELS HAVE MOISTENED UP THINGS FOR TUESDAY. THEY NOW
BRING IN SOME RAIN AND SNOW INTO THE CWA FOR TUESDAY. QPF IS NOT
VERY HIGH, WITH ONLY ONE OR TWO TENTHS OF AN INCH OF LIQUID. SO,
WILL KEEP A MENTION OF PRECIP IN THE FORECAST FOR TUESDAY AND
TUESDAY NIGHT.
FOR WEDNESDAY, THERE COULD BE SOME WEAK LAKE RESPONSE TO THE FRONT
PASSING, BUT IT SHOULD BE VERY LIGHT, IF ANY AT ALL. OTHERWISE,
THE CWA WILL SEE QUIET WEATHER AS HIGH PRESSURE BUILDS BACK IN FOR
WEDNESDAY NIGHT THROUGH THURSDAY. BY THURSDAY AFTERNOON, MODELS
INDICATE THERE WILL BE ANOTHER LOW PRESSURE SYSTEM MOVING IN FROM
THE NORTHERN PLAINS. THIS WILL BRING A WEAK WARM FRONT INTO THE
AREA FOR THURSDAY NIGHT. THIS WILL BRING YET ANOTHER CHANCE FOR
PRECIPITATION. INDICATIONS ARE IT COULD BE ALL SNOW. HOWEVER, IT
IS WAY OUT IN THE FORECAST AND CONFIDENCE IS PRETTY LOW IN THE
MODELS AT THIS TIME.
&&
.AVIATION /06Z SATURDAY THROUGH WEDNESDAY/...
THOUGH A VERY DRY AIR MASS IS MOVING INTO THE REGION...NORTH-
NORTHWEST FLOW OFF OF LAKE ONTARIO WILL KEEP SOME MOISTURE TRAPPED
UNDER INVERSION FOR MAINLY MVFR CIGS /EXCEPT KRME/ FOR MUCH OF THE
NIGHT...AND A FEW FLURRIES FOR SOME TERMINALS. MVFR CIGS BREAK UP
BY 07-08Z...IN FAVOR OF HIGHER CIGS AROUND 120 KFT AS A WEAK UPPER
DISTURBANCE COMES THROUGH. VFR FOR BALANCE OF TAF PERIOD...AS EVEN
THE HIGHER CIGS LEAVE WITH QUICK EXIT OF UPPER DISTURBANCE BY MID
MORNING. BUILDING SURFACE HIGH PRESSURE KEEPS WINDS LIGHT.
.OUTLOOK...
SAT NGT/SUN...VFR.
SUN NGT/MON MRG...MVFR POSSIBLE IN LIGHT SNOW. LATER MONDAY INTO
MON AFTN/NGT...VFR.
TUE...MVFR IN RAIN AND SNOW SHOWERS.
WED...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...MDP/RRM
NEAR TERM...HEDEN/MDP/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...MDP
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
650 PM EST SUN DEC 25 2011
.SYNOPSIS...
A QUICK MOVING UPPER LEVEL DISTURBANCE WILL BRING A BRIEF PERIOD OF
RAIN THIS EVENING. LOW PRESSURE EMERGING FROM THE WESTERN GULF OF
MEXICO WILL BRING A BETTER CHANCE OF SIGNIFICANT RAIN TUESDAY.
DRIER WEATHER COUPLED WITH SEASONABLE TEMPERATURES IS EXPECTED FOR
THE MIDDLE AND END OF THE WEEK.
.NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM SUNDAY...THICKER AND OPAQUE CLOUDS CONTINUE TO
OVERSPREAD THE AREA WITH SE NC THE LAST TO SUCCUMB TO THE
BROKEN TO OVERCAST SKY CONDITIONS. MODELS INDICATE THE PASSAGE OF A
RELATIVELY WEAK SOUTHERN STREAM UPPER S/W TROUGH ACROSS THE CAROLINA
COASTS THIS EVENING. HRRR FOR THE PAST SEVERAL RUNS CONTINUES TO
BACK DOWN WITH PCPN COVERAGE...INTENSITY AND OVERALL CHANCES FOR
LATE THIS AFTERNOON INTO THE EARLY EVENING. INITIALLY VIRGA WILL
OCCUR DUE TO A RELATIVELY DRY ATMOSPHERE ACROSS THE FA. AS MOISTURE
INCREASES THROUGHOUT THE ATM COLUMN...PATCHY LIGHT RAIN WILL DEVELOP
UNDER 8K TO 10K CEILINGS. OVERALL...THE INLAND SC ILM CWA WILL HAVE
THE BEST POTENTIAL FOR ACCUMULATING PCPN...AND IS NOW REFLECTED WITH
THE LATEST POP TRENDS AND THE QPF. THE COLD FRONT EXTENDING FROM THE
NORTHERN STREAM SFC LOW AND ITS ASSOCIATED UPPER S/W TROF TO TRACK
ACROSS THE ILM CWA AND OFFSHORE THIS EVENING. DECENT CAA WILL
FOLLOW...WITH 1K-8H THICKNESSES AND 8H TEMPS DROPPING AFTER THE CFP.
THE BEST CAA WILL OCCUR LATE THIS EVENING THROUGH DAYBREAK MONDAY.
THE COLD AIR WILL BE SHALLOW IN DEPTH...AS DEPICTED BY VARIOUS MODEL
1K TO 5H THICKNESS TRENDS...WHICH ONLY SLIGHTLY LOWER DURING THE
PEAK OF THE CAA DURING THE OVERNIGHT HOURS.
&&
.SHORT TERM /6 AM MONDAY THROUGH 6 AM WEDNESDAY/...
AS OF 3 PM SUNDAY...CURRENTLY A 500 MB CUT OFF LOW IS LOCATED OVER
THE TEXAS PANHANDLE PLAINS...THE GLOBAL MODELS ARE LIFTING AND
OPENING UP THIS CUTOFF LOW AND MOVING ITS REMNANT TROUGH AXIS TO
EASTERN NORTH CAROLINA BY 06 UTC WEDNESDAY NIGHT. THE LATEST MODELS
ARE SHOWING THAT THE GFS AS THE FASTEST WITH THIS TROUGH AND THE
NAM...GEM AND ECMWF MODELS BEING SLOWER.
AT THE SURFACE...HIGH PRESSURE WILL CONTROL THE WEATHER FOR MONDAY
BUT WILL QUICKLY GIVE WAY TO A VERY DYNAMIC LOW PRESSURE SYSTEM THAT
WILL SWEEP ACROSS THE AREA TUESDAY AFTERNOON AND EVENING. AT 5000
FEET THE MODELS ARE DEPICTING A LOW LEVEL JET OF 60 TO 70 KNOTS
MOVING ACROSS WESTERN SOUTH CAROLINA INTO CENTRAL NORTH CAROLINA.
OUR FORECAST AREA WILL BE ON THE SOUTHEASTERN FRINGES OF THE WIND
MAXIMUM. THE GFS 0-2.5 BULK SHEAR SHOWS VALUES IN THE 50-55 KT RANGE
AND THE NAM IS ABOUT 5 TO 10 KNOTS LOWER. THE OTHER ISSUE WILL BE
THE RETURN OF THE LOW LEVEL MOISTURE...MODEL DEWPOINTS WILL STRUGGLE
TO GET TO 60 DEGREES...THE MOISTURE RETURN WINDOW IS IN A VERY SMALL
AND TIMING AND INTENSITY OF THIS MOISTURE SURGE WILL BE KEY IF
CONVECTION IS TO TAKE PLACE. LOOKING AT THE STABILITY...THE NAM
SHOWS AROUND 600 J/KG AT 18 UTC TUESDAY WHILE THE GFS COMPUTED CAPE
IS INDICATING THAT THE BEST STABILITY WILL BE SHUNTED JUST OFF THE
COAST. DUE TO UNCERTAINTY WITH THE TIMING AND MAX WINDS JUST TO THE
WEST WILL GO WITH LIKELY SHOWERS AND ISOLATED THUNDERSTORMS FOR
TUESDAY.
FOR TEMPERATURES WILL STAY WITH MID 50S ON MONDAY AROUND 40 FOR LOWS
MONDAY NIGHT. WITH RETURN FLOW AHEAD OF THE SURFACE LOW WILL SHOW
TEMPERATURES REBOUNDING INTO THE MID TO UPPER 60S TUESDAY AND AS THE
FRONT SHIFTS QUICKLY BY EXPECT LOWS TO FALL BACK TO THE LOWER TO
MIDDLE 40S TUESDAY NIGHT.
&&
.LONG TERM /WEDNESDAY THROUGH SUNDAY/...
AS OF 300 PM SUNDAY...POTENT 500 MB TROUGH EJECTING OFF TO THE NE AT
THE START OF THE PERIOD WILL LEAVE IN ITS WAKE BROAD TROUGHING
ACROSS THE EASTERN THIRD OF THE COUNTRY. WEAK...LOW AMPLITUDE WAVES
WILL REPEATEDLY RACE OVERHEAD...BUT NO SURFACE IMPACTS WILL BE
REALIZED OTHER THAN BOUTS OF CLOUD COVER. STRONGER SHORTWAVE SPAWNS
A NORTHERN STREAM SYSTEM THAT WILL TRY TO DRAG A COLD FRONT THROUGH
LATE FRIDAY/EARLY SATURDAY...BUT ONCE AGAIN MAY GET HUNG UP TO THE
NORTH AND WASH OUT. WITH PWATS ONLY RECOVERING TO AROUND ONE-HALF
INCH BY SATURDAY...EVEN IF FRONT DOES MAKE IT THROUGH THE AREA
EXPECT IT TO BE DRY.
WEAK CAA ON WEDNESDAY WILL BRING THE COLDEST DAY OF THE
EXTENDED...WITH TEMPS A DEGREE OR TWO BELOW NORMAL FOR BOTH MAX/MIN.
TEMPS REBOUND THROUGH THE REST OF THE WEEK WITH SEASONABLE NORMS
RISING TO SLIGHTLY ABOVE NORMAL FOR THE WKND. MINS EACH DAY THU-SUN
WILL BE IN THE MID 30S TO AROUND 40.
&&
.AVIATION /00Z MONDAY THROUGH FRIDAY/...
AS OF 00Z...ANTICIPATE VFR THROUGH VALID PERIOD...THOUGH CANNOT RULE
OUT BRIEF PERIODS OF MVFR OVERNIGHT THROUGH EARLY MONDAY MORNING.
CURRENT RADAR DEPICTS AN AREA OF LIGHT RAIN STRETCHED ACROSS EASTERN
PORTION OF THE CWA...AFFECTING THE COASTAL SITES ATTM. DO NOT EXPECT
ANY RESTRICTIONS EXCEPT IN HEAVIER SHOWERS...WHICH AM EXPECTING WILL
BE BRIEF. GIVEN SOURCE OF LOW LEVEL MOISTURE...ONLY CONCERNS
OVERNIGHT ARE A LOW-LEVEL STRATUS LAYER FORMING AND PATCHY FOG.
GIVEN FCST SOUNDINGS...TIME-SECTION HEIGHTS...AND UNCERTAINTY OF
OPACITY WITH LOW-LEVEL STRATUS...HAVE OPTED TO KEEP STRATUS LAYER AT
3000FT...THOUGH COULD DIP LOWER INTO MVFR RESTRICTIONS ESPECIALLY
BEHIND THE FRONT. SOUTHWEST WINDS WILL BECOME WEST-NORTHWEST
OVERNIGHT...WITH SUSTAINED WINDS AOB 8KTS. FOR NOW...HAVE INTRODUCED
POTENTIAL FOG AT KFLO AFTER MIDNIGHT...POSSIBLY BECOMING MVFR.
HOWEVER...CONFIDENCE IS LOW GIVEN ANTICIPATED CLOUD COVER. AFTER
DAYBREAK...EXPECT SKY COVER TO BECOME SKC...AND CONTINUE THROUGH
VALID PERIOD. WINDS WILL SHIFT NORTHEAST...WITH SUSTAINED WINDS AOB
10KTS...WITH GUSTS 15-18KTS POSSIBLE. AFTER SUNSET...WINDS WILL
BECOME EASTERLY...WITH WINDS AOB 5KTS.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SHOWERS AND INTERMITTENT
IFR CONDITIONS TUESDAY. VFR WEDNESDAY THROUGH FRIDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 230 PM SUNDAY...WEAK SFC BOUNDARY TO NEARLY SPLIT THE ILM
COASTAL WATERS THIS AFTERNOON. WIND DIRECTIONS WILL BE THE PROBLEM
CHILD PRIOR TO THE CFP THIS EVENING. HAVE GONE WITH WIND SPEEDS 10
KT OR LESS THROUGH EARLY THIS EVENING DUE TO A RELAXED SFC PG AHEAD
OF THE COLD FRONT. EXPECT VARIABLE WINDS THROUGH EARLY THIS EVENING.
COLD FRONT EXTENDING FROM THE SE CANADA/NE STATES DEEPENING
LOW...WILL DROP SE AND SWEEP ACROSS THE ILM WATERS AND OFFSHORE
DURING THIS EVENING. TIGHTENED SFC PG IN THE WAKE OF THE FRONT AND
THE SHALLOW CAA SURGE TO COMBINE AND PRODUCE W TO NW WINDS REACHING
SCA CRITERIA ACROSS THE ILM NC WATERS PRIOR TO MIDNIGHT.
THESE WINDS ARE PROGGED TO CONTINUE AT THESE SPEEDS THROUGH
DAYBREAK MONDAY. THE ILM SC WATERS ARE PROGGED TO SEE 15-20 KT WIND
SPEEDS. SIGNIFICANT SEAS WILL BE DOMINATED BY AN EASTERLY 1-3 FT
GROUND SWELL AT 8 TO 10 SECOND PERIODS THIS AFTERNOON INTO EARLY
THIS EVENING. DUE TO THE W TO NW FETCH...SIGNIFICANT SEAS WILL BUILD
TO 2 TO 4 FT...WITH THE LOCALLY PRODUCED WIND WAVES EXHIBITING 3-5
SECOND PERIODS. THIS WILL BECOME THE DOMINATE PLAYER WITHIN THE SEAS
SPECTRUM OVERNIGHT. A FEW 5 FOOTERS REMAIN POSSIBLE ACROSS THE OUTER
WATERS OFF CAPE FEAR OVERNIGHT.
TIDE LEVELS ARE PREDICTED TO DROP TO AROUND -1.00 MLLW LATE TONIGHT.
THERE WILL BE A 2 HR WINDOW SURROUNDING LOW TIDE TONIGHT THAT WILL
BE SUBJECT TO THESE LOWER READINGS. LOW TIDE TO OCCUR BETWEEN 130 AM
TO 200 AM MONDAY.
SHORT TERM /6 AM MONDAY THROUGH 6 AM WEDNESDAY/...
AS OF 3 PM SUNDAY...ON MONDAY MORNING A HIGH PRESSURE CENTER WILL
SHIFT ACROSS THE AREA AND NORTHWEST FLOW WILL WEAKEN AND SEAS THAT
WILL START AT 6 FT AROUND 7 AM AND THIS WILL CAUSE THE SMALL CRAFT
ADVISORY SEAS NORTH OF CAPE FEAR TO FALL BELOW ADVISORY LEVELS. AS A
DEVELOPING LOW PRESSURE CENTER QUICKLY MOVES BY TO THE WEST AND
NORTH OF THE MARINE AREA...WINDS WILL QUICKLY VEER TO THE SOUTH BY
TUESDAY MORNING. WINDS ARE EXPECTED TO REACH STRONG SMALL CRAFT
VALUES AND JUST BELOW GALE FORCE BY TUESDAY AFTERNOON. SEAS WILL
QUICKLY RESPONDS AND SHOULD MAX OUT AT 8 FEET TUESDAY AFTERNOON.
ALSO...WITH A STRONG WEST WINDS AROUND 03 UTC WEDNESDAY WILL HAVE TO
WATCH CAREFULLY FOR LOW TIDES THAT MAYBE BELOW 1 FOOT MLLW.
LONG TERM/WEDNESDAY THROUGH FRIDAY/...
AS OF 300 PM SUNDAY...COLD FRONT EXITING TO THE EAST TO START THE
PERIOD LEAVING NW WINDS AROUND 10 KTS AND SEAS 2-4 FT EARLY
WEDNESDAY...HIGHEST ACROSS THE NORTHERN WATERS. SEAS DECLINE RAPIDLY
BY WEDNESDAY EVE DUE TO ADVANCE OF HIGH PRESSURE. THIS EASES THE
GRADIENT AND CREATES SEAS OF ONLY 1-2 FT UNDER VARIABLE
WINDS...BECOMING WEST FRIDAY AT LESS THAN 10 KTS. WINDS INCREASE
FROM THE SW AHEAD OF A WEAK COLD FRONT APPROACHING FROM THE WEST
FRIDAY NIGHT...BUILDING SEAS TO 2-3 FT.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 AM TO 9 AM EST MONDAY FOR
AMZ250-252.
&&
$$
NEAR TERM...DCH
SHORT TERM...HAWKINS
LONG TERM...JDW
AVIATION...SGL
AREA FORECAST DISCUSSION...UPDATED
NWS AUSTIN/SAN ANTONIO TX
946 PM CST SUN DEC 25 2011
.UPDATE...
PREVIOUS WEATHER FORECAST IS ON TRACK FOR THIS EVENING INTO MONDAY.
HOWEVER...LOWER MIN TEMPS FROM 1-3 DEGREES FROM WEST OF I 83 BASED
ON CURRENT TEMPS ACROSS THE VAL VERDE AND EDWARDS PLATEAU AREAS
AND THE LATEST NAM AND RUC SOLUTIONS. UPDATED ZONE OUT SHORTLY.
&&
.PREV DISCUSSION... /ISSUED 537 PM CST SUN DEC 25 2011/
AVIATION...
MVFR AT KAUS/KSAT/KSSF WILL DRIFT DOWN TO TEMPO IFR AT TIMES AFTER
08Z AS A LOBE OF THE UPPER LOW MOVES ACROSS THE AREA LATE TONIGHT.
DECIDED TO PUT -DZ INTO THE TAFS...BUT VERY...VERY LIGHT AND
SHOULD NOT BE AN ICING PROBLEM UP TO ABOUT 10500 FT MSL WHERE THE
FREEZING LEVEL IS. DRIER AIR BEHIND THE SHORTWAVE LOBE WILL BEGIN
TO LIFT CIGS BY 18Z AND YIELD CLEAR SKIES AROUND 00Z TUE.
PREV DISCUSSION... /ISSUED 347 PM CST SUN DEC 25 2011/
DISCUSSION...
ONE LAST ROUND OF RAIN FOR THIS YEAR IS EXPECTED AS THE UPPER
LEVEL LOW OVER WESTERN TEXAS AND A SHORT-WAVE OVER NORTHWESTERN
MEXICO MOVE EAST ACROSS TEXAS TONIGHT INTO MONDAY. THE CANADIAN...
NAM AND GFS HAVE TRENDED DRIER WITH THE 12Z AND 18Z RUNS WHILE THE
ECMWF AND UKMET RETAIN SOME QPF. DUE TO A MOIST AIRMASS...
ESPECIALLY ACROSS THE EAST...ELEVATED UPWARD FORCING WILL GENERATE
MAINLY LIGHT RAIN. EXPECT RAIN TO BEGIN AROUND MIDNIGHT AND END BY
AROUND NOON MOST AREAS. CANNOT RULE OUT SOME LIGHTNING STRIKES
OVER THE FAR EAST AS THE UPPER LOW MOVES OVER THAT AREA...ALTHOUGH
TOO ISOLATED TO MENTION. AFTER THE UPPER LEVEL SYSTEM MOVES EAST..
A DRY WEST TO NORTHWEST FLOW ALOFT WILL FINISH OUT THIS YEAR WITH
A WARMING TREND. A WEAK UPPER LEVEL TROUGH IS INDICATED TO MOVE
ACROSS TEXAS LATE ON WEDNESDAY. IT ENCOUNTERS A DRY AIRMASS AND NO
RAIN IS EXPECTED. ITS ONLY IMPACT IS TO DELAY EVEN WARMER
TEMPERATURES BY A DAY. OVER THE NEW YEARS WEEKEND...AN UPPER LEVEL
TROUGH MOVES ACROSS THE PLAINS STATES. SOME MOISTURE RETURNS ON
SOUTHERLY WINDS...ALTHOUGH ONLY ENOUGH FOR PATCHY DRIZZLE ACROSS
THE EAST. FOR NOW...WILL LEAVE OUT OF FORECAST. THE NEXT
SIGNIFICANT COLD FRONT IS SHOWN TO MOVE ACROSS SOUTH CENTRAL TEXAS
LATE ON NEW YEARS DAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 55 36 62 37 / 20 30 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 40 55 30 62 30 / 20 30 0 0 0
NEW BRAUNFELS MUNI AIRPORT 42 56 32 64 34 / 20 30 0 0 0
BURNET MUNI AIRPORT 34 52 31 59 32 / 20 20 - 0 0
DEL RIO INTL AIRPORT 30 59 34 64 35 / - - 0 0 0
GEORGETOWN MUNI AIRPORT 38 52 33 60 33 / 20 30 - 0 0
HONDO MUNI AIRPORT 40 59 28 65 31 / 10 10 0 0 0
SAN MARCOS MUNI AIRPORT 41 55 32 63 33 / 20 30 0 0 0
LA GRANGE - FAYETTE REGIONAL 43 53 36 62 35 / 30 50 10 0 0
SAN ANTONIO INTL AIRPORT 41 58 36 65 37 / 20 20 0 0 0
STINSON MUNI AIRPORT 43 59 34 66 36 / 20 20 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...26
SYNOPTIC/GRIDS...17
PUBLIC SERVICE/DATA COLLECTION...22
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
1130 AM CST SAT DEC 24 2011
.DISCUSSION...UPDATED FOR 18Z TAFS.
&&
.AVIATION...IFR CEILINGS WILL BE ON TAP THROUGH SUNDAY MORNING...
ALONG WITH BREEZY NORTHWEST WINDS AS HIGH PRESSURE CONTINUES TO
FILTER INTO THE REGION. ALTHOUGH PERIODS OF LIGHT RAIN WILL STILL
BE POSSIBLE AT THE TAF SITES...CHANCES WILL MAINLY BE CONFINED TO
A COASTAL TROUGH AND LOW PRESSURE AREA OFFSHORE. THE FORECAST
CALLS FOR A GRADUAL WEAKENING OF THE TROUGH OFFSHORE ON SUNDAY AS
HIGH PRESSURE KEEPS ON COMING IN FROM THE NORTH. NORTHWEST WINDS
WILL DECREASE TO MODERATE ON SUNDAY AS RAIN CHANCES ALSO DWINDLE.
CEILINGS WILL BEGIN TO RISE TO MVFR CRITERIA SUNDAY DURING THE
DAY.
&&
.PREV DISCUSSION... /ISSUED 732 AM CST SAT DEC 24 2011/
DISCUSSION...UPDATED WINDS AND TEMPS TO REFLECT CURRENT TRENDS.
SOLID CLOUD COVER AND NORTH WINDS...ALONG WITH CONTINUED PERIODS
OF RAIN...WILL KEEP TEMPS LOWER TODAY. UPDATED WITH RUC WINDS AS
THEY INITIALIZED BEST. RUC NOT AS BULLISH ON LOW PRESSURE CENTER
OFFSHORE...PREFERRING CONTINUED TROUGHING.
PREV DISCUSSION... /ISSUED 547 AM CST SAT DEC 24 2011/
DISCUSSION...SEE THE AVIATION SEGMENT BELOW FOR THE DISCUSSION OF
THE 06Z TAF ISSUANCE.
AVIATION...LIFR AND IFR CONDITIONS WILL CONTINUE THROUGH THE DAY
AS A SURFACE COASTAL TROUGH INTERACTS WITH SOUTHWEST FLOW ALOFT.
EXPECT LIGHT RAIN SHOWERS...DRIZZLE AND FOG THROUGH OUT THE DAY AS
IN EACH SITE ESPECIALLY IN THE AFTERNOON HOUR. VISIBILITY MAY BE
REDUCED AT TIMES DUE TO PATCHY FOG AND LIGHT RAIN. NORTH WINDS
WILL INCREASE THROUGH OUT THE DAY AS WELL WITH GUSTS UP TO 30 KTS.
PREV DISCUSSION... /ISSUED 445 AM CST SAT DEC 24 2011/
SHORT TERM /TODAY THROUGH SUNDAY/...LIGHT RAIN SHOWERS OR DRIZZLE WILL
CONTINUE TO IMPACT THE RIO GRANDE VALLEY TODAY AS AN AREA OF LOW
PRESSURE CONTINUES TO MOVE EASTWARD OVER CENTRAL TEXAS AND
INTERACTS WITH A COASTAL TROUGH OVER THE REGION TODAY. EXPECT
REDUCED VISIBILITIES AND POSSIBLE AREAS OF PATCHY FOG ACROSS THE
RIO GRANDE VALLEY THROUGH THE DAY. MOST OF THE SHOWER ACTIVITY
WILL BE STRATIFORM TYPE AND WITH LITTLE ACCUMULATION EXPECTED. THE
HIGHER CHANCE OF SOME WIDESPREAD SHOWER ACTIVITY WILL BE SATURDAY
MORNING OVER THE LOWER PART OF THE RIO GRANDE VALLEY AND SHIFT TO
THE NORTHERN PART OF THE FORECAST AREA INTO THE AFTERNOON HOURS.
PRECIPITATION WILL BEGIN TO DIMINISH SATURDAY EVENING AS THE
COASTAL SURFACE TROUGH SHIFTS FURTHER EAST AND NORTHEAST.
NORTHERLY WINDS WILL BEGIN TO SHIFT TO THE NORTHWEST AS THE LOW
PRESSURE SYSTEM OVER CENTRAL TEXAS MIGRATES EASTWARD. THIS WILL
SHIFT MOST OF THE PRECIPITATION ACTIVITY OVER THE WESTERN GULF
WATERS. HIGH TEMPERATURES WILL REMAIN IN THE MID 50S ACROSS THE
RIO GRANDE VALLEY TODAY AND INTO SUNDAY. CHRISTMAS MORNING WILL
START OFF FAIRLY COOL WITH LOW TEMPERATURES IN THE MID 40S FOR
MOST OF THE RIO GRANDE VALLEY. HIGH TEMPERATURES ON CHRISTMAS
WILL NOT REBOUND MUCH LATER IN THE DAY DUE TO LINGERING CLD COVER
AND CONTINUED CAA FROM THE NW SURFACE FLOW PREVAILS.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...UPPER LOW OVER THE
TEXAS PANHANDLE SUNDAY NIGHT WILL MOVE EAST TO THE ARKLATEX REGION
LATE MONDAY AFTERNOON. CLOUDS WILL SLOWLY ERODE MONDAY MORNING AS
THE WAVE FINALLY MOVES EAST AND VERY DRY AIR FILTERS INTO DEEP
SOUTH TEXAS. THE UPPER VALLEY AND RANCHLANDS WILL BEGIN TO CLEAR
MONDAY MORNING AND THE LOWER VALLEY IN THE AFTERNOON. HIGH
TEMPERATURES MONDAY WILL BE IN THE LOW TO MID 60S. A COLD NIGHT IS
EXPECTED MONDAY NIGHT WITH TEMPERATURES IN THE UPPER 30S NORTHERN
AREAS TO THE LOWER/MID 40S NEAR THE COAST. NICE WEATHER IS
EXPECTED ACROSS THE RIO GRANDE VALLEY TUESDAY THROUGH THURSDAY AS
NORTHWEST FLOW ALOFT COMBINES WITH WEAK SURFACE FLOW AND GENERAL
WEAK HIGH PRESSURE AT THE SURFACE. SEASONAL TEMPERATURES
TUESDAY...LOWER 70S...WILL CLIMB INTO THE MID TO UPPER 70S
WEDNESDAY...AND NEAR 80 THURSDAY AND FRIDAY AS WEAK SOUTHERLY FLOW
RETURNS. DRY CONDITIONS WILL PERSIST THROUGH MOST OF THE WEEK BUT
RAIN CHANCES INCREASE LATE IN THE WEEK AS A WEAK COASTAL TROUGH
DEVELOPS OFF THE LOWER TEXAS COAST.
MARINE...
TODAY THROUGH SUNDAY...STRONG NORTH TO NORTHEAST WINDS WILL IMPACT
THE COASTAL WATERS TODAY AS AN UPPER LEVEL SYSTEM OVER CENTRAL TEXAS
MOVES SLOWLY EASTWARD TODAY AND INTERACTS WITH A COASTAL TROUGH OVER
THE REGION. THIS WILL INCREASE WAVE HEIGHTS UP TO 10 FOOT ESPECIALLY
OVER THE OFFSHORE WATERS OF THE GULF SATURDAY AFTERNOON. EXPECT SCA
CONDITIONS FOR THE NEXT 12 TO 24 HOURS INCLUDING THE BAY AREA. SHOWERS
AND PATCHY FOG WILL CONTINUE THROUGH THE DAY AND INTO SUNDAY AS THE
COASTAL TROUGH MOVES TO THE NORTHEAST. HIGH SEAS IN ADDITION TO A
HIGH TIDE THIS EVENING WILL INCREASE THE WAVE HEIGHTS EVEN MORE.
THEREFORE WILL BE ISSUING A COASTAL FLOOD ADVISORY TODAY FOR THE BAY
AREA. THESE HIGH WAVE HEIGHTS WILL CONTINUE INTO SUNDAY BUT WILL
BEGIN TO DIMINISH LATER SUNDAY EVENING AND IMPROVE INTO THE WEEK AS
THE PRESSURE GRADIENT WEAKENS SOME.
SUNDAY NIGHT THROUGH WEDNESDAY...A SMALL CRAFT ADVISORY MAY BE NEED
SUNDAY NIGHT THROUGH MONDAY AFTERNOON AS THE TIGHT PRESSURE GRADIENT
OVER THE GULF OF MEXICO WILL RESULT IN ELEVATED WINDS AND SEAS
THROUGH MONDAY AFTERNOON. THE PRESSURE GRADIENT BEGINS TO RELAX
MONDAY AFTERNOON AND MARINE CONDITIONS STEADILY IMPROVE BY MONDAY
NIGHT. SURFACE HIGH PRESSURE SETTLES OVER THE NORTHERN GULF TUESDAY
AND WEDNESDAY RESULTING IN LIGHT WINDS AND LOW SEAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...COASTAL FLOOD ADVISORY UNTIL MIDNIGHT CST TONIGHT FOR TXZ251-256-
257.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM CST THIS EVENING FOR
GMZ130-132-135.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SUNDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
54/52
AREA FORECAST DISCUSSION...UPDATED
NWS BROWNSVILLE TX
732 AM CST SAT DEC 24 2011
.DISCUSSION...UPDATED WINDS AND TEMPS TO REFLECT CURRENT TRENDS.
SOLID CLOUD COVER AND NORTH WINDS...ALONG WITH CONTINUED PERIODS
OF RAIN...WILL KEEP TEMPS LOWER TODAY. UPDATED WITH RUC WINDS AS
THEY INITIALIZED BEST. RUC NOT AS BULLISH ON LOW PRESSURE CENTER
OFFSHORE...PREFERRING CONTINUED TROUGHING.
&&
.PREV DISCUSSION... /ISSUED 547 AM CST SAT DEC 24 2011/
DISCUSSION...SEE THE AVIATION SEGMENT BELOW FOR THE DISCUSSION OF
THE 06Z TAF ISSUANCE.
AVIATION...LIFR AND IFR CONDITIONS WILL CONTINUE THROUGH THE DAY
AS A SURFACE COASTAL TROUGH INTERACTS WITH SOUTHWEST FLOW ALOFT.
EXPECT LIGHT RAIN SHOWERS...DRIZZLE AND FOG THROUGH OUT THE DAY AS
IN EACH SITE ESPECIALLY IN THE AFTERNOON HOUR. VISIBILITY MAY BE
REDUCED AT TIMES DUE TO PATCHY FOG AND LIGHT RAIN. NORTH WINDS
WILL INCREASE THROUGH OUT THE DAY AS WELL WITH GUSTS UP TO 30 KTS.
PREV DISCUSSION... /ISSUED 445 AM CST SAT DEC 24 2011/
SHORT TERM /TODAY THROUGH SUNDAY/...LIGHT RAIN SHOWERS OR DRIZZLE WILL
CONTINUE TO IMPACT THE RIO GRANDE VALLEY TODAY AS AN AREA OF LOW
PRESSURE CONTINUES TO MOVE EASTWARD OVER CENTRAL TEXAS AND
INTERACTS WITH A COASTAL TROUGH OVER THE REGION TODAY. EXPECT
REDUCED VISIBILITIES AND POSSIBLE AREAS OF PATCHY FOG ACROSS THE
RIO GRANDE VALLEY THROUGH THE DAY. MOST OF THE SHOWER ACTIVITY
WILL BE STRATIFORM TYPE AND WITH LITTLE ACCUMULATION EXPECTED. THE
HIGHER CHANCE OF SOME WIDESPREAD SHOWER ACTIVITY WILL BE SATURDAY
MORNING OVER THE LOWER PART OF THE RIO GRANDE VALLEY AND SHIFT TO
THE NORTHERN PART OF THE FORECAST AREA INTO THE AFTERNOON HOURS.
PRECIPITATION WILL BEGIN TO DIMINISH SATURDAY EVENING AS THE
COASTAL SURFACE TROUGH SHIFTS FURTHER EAST AND NORTHEAST.
NORTHERLY WINDS WILL BEGIN TO SHIFT TO THE NORTHWEST AS THE LOW
PRESSURE SYSTEM OVER CENTRAL TEXAS MIGRATES EASTWARD. THIS WILL
SHIFT MOST OF THE PRECIPITATION ACTIVITY OVER THE WESTERN GULF
WATERS. HIGH TEMPERATURES WILL REMAIN IN THE MID 50S ACROSS THE
RIO GRANDE VALLEY TODAY AND INTO SUNDAY. CHRISTMAS MORNING WILL
START OFF FAIRLY COOL WITH LOW TEMPERATURES IN THE MID 40S FOR
MOST OF THE RIO GRANDE VALLEY. HIGH TEMPERATURES ON CHRISTMAS
WILL NOT REBOUND MUCH LATER IN THE DAY DUE TO LINGERING CLD COVER
AND CONTINUED CAA FROM THE NW SURFACE FLOW PREVAILS.
LONG TERM /SUNDAY NIGHT THROUGH FRIDAY/...UPPER LOW OVER THE
TEXAS PANHANDLE SUNDAY NIGHT WILL MOVE EAST TO THE ARKLATEX REGION
LATE MONDAY AFTERNOON. CLOUDS WILL SLOWLY ERODE MONDAY MORNING AS
THE WAVE FINALLY MOVES EAST AND VERY DRY AIR FILTERS INTO DEEP
SOUTH TEXAS. THE UPPER VALLEY AND RANCHLANDS WILL BEGIN TO CLEAR
MONDAY MORNING AND THE LOWER VALLEY IN THE AFTERNOON. HIGH
TEMPERATURES MONDAY WILL BE IN THE LOW TO MID 60S. A COLD NIGHT IS
EXPECTED MONDAY NIGHT WITH TEMPERATURES IN THE UPPER 30S NORTHERN
AREAS TO THE LOWER/MID 40S NEAR THE COAST. NICE WEATHER IS
EXPECTED ACROSS THE RIO GRANDE VALLEY TUESDAY THROUGH THURSDAY AS
NORTHWEST FLOW ALOFT COMBINES WITH WEAK SURFACE FLOW AND GENERAL
WEAK HIGH PRESSURE AT THE SURFACE. SEASONAL TEMPERATURES
TUESDAY...LOWER 70S...WILL CLIMB INTO THE MID TO UPPER 70S
WEDNESDAY...AND NEAR 80 THURSDAY AND FRIDAY AS WEAK SOUTHERLY FLOW
RETURNS. DRY CONDITIONS WILL PERSIST THROUGH MOST OF THE WEEK BUT
RAIN CHANCES INCREASE LATE IN THE WEEK AS A WEAK COASTAL TROUGH
DEVELOPS OFF THE LOWER TEXAS COAST.
MARINE...
TODAY THROUGH SUNDAY...STRONG NORTH TO NORTHEAST WINDS WILL IMPACT
THE COASTAL WATERS TODAY AS AN UPPER LEVEL SYSTEM OVER CENTRAL TEXAS
MOVES SLOWLY EASTWARD TODAY AND INTERACTS WITH A COASTAL TROUGH OVER
THE REGION. THIS WILL INCREASE WAVE HEIGHTS UP TO 10 FOOT ESPECIALLY
OVER THE OFFSHORE WATERS OF THE GULF SATURDAY AFTERNOON. EXPECT SCA
CONDITIONS FOR THE NEXT 12 TO 24 HOURS INCLUDING THE BAY AREA. SHOWERS
AND PATCHY FOG WILL CONTINUE THROUGH THE DAY AND INTO SUNDAY AS THE
COASTAL TROUGH MOVES TO THE NORTHEAST. HIGH SEAS IN ADDITION TO A
HIGH TIDE THIS EVENING WILL INCREASE THE WAVE HEIGHTS EVEN MORE.
THEREFORE WILL BE ISSUING A COASTAL FLOOD ADVISORY TODAY FOR THE BAY
AREA. THESE HIGH WAVE HEIGHTS WILL CONTINUE INTO SUNDAY BUT WILL
BEGIN TO DIMINISH LATER SUNDAY EVENING AND IMPROVE INTO THE WEEK AS
THE PRESSURE GRADIENT WEAKENS SOME.
SUNDAY NIGHT THROUGH WEDNESDAY...A SMALL CRAFT ADVISORY MAY BE NEED
SUNDAY NIGHT THROUGH MONDAY AFTERNOON AS THE TIGHT PRESSURE GRADIENT
OVER THE GULF OF MEXICO WILL RESULT IN ELEVATED WINDS AND SEAS
THROUGH MONDAY AFTERNOON. THE PRESSURE GRADIENT BEGINS TO RELAX
MONDAY AFTERNOON AND MARINE CONDITIONS STEADILY IMPROVE BY MONDAY
NIGHT. SURFACE HIGH PRESSURE SETTLES OVER THE NORTHERN GULF TUESDAY
AND WEDNESDAY RESULTING IN LIGHT WINDS AND LOW SEAS.
&&
.BRO WATCHES/WARNINGS/ADVISORIES...
TX...COASTAL FLOOD ADVISORY FROM NOON TODAY TO MIDNIGHT CST TONIGHT
FOR TXZ251-256-257.
GM...SMALL CRAFT ADVISORY FOR WINDS UNTIL 6 PM CST THIS EVENING FOR
GMZ130-132-135.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SUNDAY FOR GMZ150-155-170-
175.
&&
$$
THIS PRODUCT IS ALSO AVAILABLE ON THE WEB AT:
HTTP://WWW.WEATHER.GOV/BROWNSVILLE
54/52/58
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1103 PM EST SUN DEC 25 2011
.SYNOPSIS...
A FAST MOVING CLIPPER SYSTEM WILL MOVE ACROSS THE REGION FROM THE
WEST OVERNIGHT AND OFFSHORE EARLY MONDAY. HIGH PRESSURE WILL
BUILD EAST BEHIND THIS FEATURE LATE TONIGHT INTO MONDAY BEFORE
PASSING OFF THE COAST LATE MONDAY NIGHT. A DEVELOPING LOW
PRESSURE STORM SYSTEM WILL WORK NORTHEAST FROM THE GULF COAST
REGION MONDAY NIGHT...AND INTO THE MID ATLANTIC STATES ON
TUESDAY...RESULTING IN ANOTHER ROUND OF SIGNIFICANT RAINFALL FOR
MUCH OF THE AREA.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 900 PM EST SUNDAY...
WEAK TROF AXIS ALONG THE MOUNTAINS CONTINUES TO SEPARATE MUCH LOWER
DEWPOINT AIR OVER THE FAR WEST/NORTH FROM MORE 30ISH NATURE
VALUES OVER THE EAST ATTM. HOWEVER AS THE APPROACHING 5H TROF AND
ASSOCIATED VORT LOBE SWING THRU IN THE NEXT FEW HOURS SHOULD SEE
DRIER AIR PUSH EAST AIDED BY INCREASING NW WINDS ACROSS THE
REGION. LATEST HRRR EVEN SURGES SPEEDS TO ADVISORY LEVELS NW NC
RIDGES WHILE MOST OTHER GUIDANCE CLOSE BUT BASICALLY KEEP THE HIGHER
SPEEDS ABOVE THE SHALLOW INVERSION AFTER MIDNIGHT. THUS HAVE
BUMPED UP SPEEDS TO JUST BELOW NPW THRESHOLDS OVER THE SW BUT EVEN
THERE EXPECT STRONGER GUSTS TO BE BRIEF AS THE QUICK SHOT OF 85H
COLD ADVECTION SWINGS THROUGH. HOWEVER MIXING SHOULD BE ENOUGH TO
HOLD TEMPS UP MOST SPOTS SINCE COLD ADVECTION ALOFT ALREADY
FADING LATE SO BUMPED UP TEMPS SLIGHTLY OUTSIDE THE VALLEYS
OVERNIGHT. OTHER ISSUE WITH CLOUDS AND POTENTIAL FOR A FEW SNOW
SHOWERS NW AS LOW LEVEL MOISTURE UNDER THE COLD POOL SWINGS ACROSS
AIDED BY UPSLOPE. SINCE EVENING SOUNDINGS QUITE ARID UNDER AN
INCREASINGLY MIXED COLUMN...AND LATEST MODELS INCLUDING THE HRRR/
LOCAL WRF SHOW ONLY A SHORT WINDOW OF POTENTIAL -SHSN...CUT POPS
BACK A BIT WITH ONLY SMALL CHCS CONFINED TO THE FAR NW SLOPES
AFTER MIDNIGHT. ELSW LEE CIRRUS MAY LINGER OVER THE SOUTH FOR A
FEW MORE HOURS BEFORE THE TROF ALOFT PASSES SO MORE PC FLAVOR THRU
HIGH CLOUDS THERE EARLY AND MOSTLY CLEAR OUTSIDE OF THE UPSLOPE NW
OVERNIGHT.
AS OF 200 PM EST SUNDAY...
SATELLITE IMAGES CONFIRM CANOPY OF HIGH CLOUDS ARE FINALLY PUSHING
SOUTH IN RESPONSE TO A NORTHERN STREAM SHORT WAVE PASSING THROUGH
THE GREAT LAKES THIS AFTERNOON. THE SHORT RANGE MODELS ARE IN GOOD
AGREEMENT THAT THE AXIS OF THIS UPPER LEVEL WAVE QUICKLY PASSES
THROUGH THE FORECAST AREA TONIGHT.
OUR LOCAL WRF MODEL AGREES WITH OTHER MODEL OUTPUT THAT LOW LEVEL
WINDS INCREASE TO 40-50 KTS AT 850MB TONIGHT AS THIS WAVE PASSES. AS
A RESULT...HAVE KEPT GUSTY WINDS IN THE FORECAST THROUGH THE
OVERNIGHT HOURS.
GOOD UPSLOPE FLOW ALONG THE WESTERN SLOPES TONIGHT SHOULD GENERATE
LOW CLOUDS. FORECAST SOUNDINGS...ESPECIALLY FROM THE GFS...KEEP A
SHALLOW LAYER OF MOISTURE THAN GENERATES SOME VERY LIGHT SNOW. LOCAL
WRF AND ARW-EAST WRF ALSO PRODUCE SNOW TONIGHT IN WESTERN GREENBRIER
COUNTY. THEREFORE...KEPT SMALL POPS FOR THIS REGION TONIGHT. ANY
SNOW THAT FALLS SHOULD BE VERY LIGHT CONSIDERING THE SHALLOW DEPTH
OF THE MOISTURE...AND EXPECT THE SNOW TO END BY DAYBREAK WITH SHORT
WAVE RIDGING RAPIDLY BUILDING IN FOR MONDAY...WHICH IS CONSIDERABLY
EARLIER THAN THE ARW-EAST WRF WHICH KEEPS SNOW THROUGH MONDAY
MORNING.
WINDS WILL RAPIDLY DIMINISH MONDAY AS THE AFOREMENTIONED UPPER LEVEL
SHORT WAVE RIDGE BUILDS INTO THE REGION...BRINGING MOSTLY CLEAR
SKIES...BEFORE HIGH CLOUDS INVADE THE REGION FROM THE WEST LATE IN
THE DAY IN ADVANCE OF THE NEXT SYSTEM.
DESPITE COLD AIR ADVECTION TONIGHT...LEANED TOWARD THE SLIGHTLY
WARMER GUIDANCE VALUES FOR LOWS TONIGHT WITH THE GUSTY WINDS
ANTICIPATED. FOR MONDAY...PREFERRED THE MUCH MORE CONSISTENT GFS MOS
OVER THE NAM MOS FOR HIGHS. WENT EVEN A DEGREE OR SO COLDER THAN
GUIDANCE FOR HIGHS MONDAY DUE TO LIMITED MIXING AND THE WARM BIAS OF
THE GUIDANCE OVER THE PAST SEVERAL DAYS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 250 PM EST SUNDAY...
GOING TO SEE SOME DIFFERENT WEATHER ELEMENTS THIS PERIOD TO DEAL
WITH. COMPUTER MODELS STILL SHOWING THE UPPER LOW OVER THE SOUTHWEST
EJECTING NORTHEAST INTO OUR AREA TUESDAY AND INTO NEW ENGLAND BY
WEDNESDAY.
MONDAY NIGHT...MODELS ARE SIMILAR IN TIMING THE PRECIP ASIDE FROM
THE SLOWER NAM. THIS MAKES FOR THE ISSUE OF WINTRY PRECIP TYPE FOR
THIS FORECAST...AND MODEL FORECAST SOUNDINGS SUGGEST A 1 TO 3 HR
PERIOD OF A FREEZING RAIN OR SLEET POTENTIAL OVER THE NC MTNS NORTH
INTO THE NEW RIVER VALLEY...GREENBRIER VALLEY AND HIGHLANDS.
ATTM...STILL LOOKS LIKE CLOUDS MAY RACE IN FAST ENOUGH TO HALT A
DRAMATIC DROP IN TEMPS MONDAY NIGHT ALTHOUGH THE SE FLOW INTO THE
MTNS WILL HELP COOL THE COLUMN OVER THE MTNS. STILL NOT SEEING A LOT
OF COVERAGE AND/OR ACCUMULATION POTENTIAL TO WARRANT ANYTHING MORE
THAN MENTION IN THE HAZARDOUS WEATHER OUTLOOK. BUT WILL BEAR
WATCHING SINCE IT COULD BE COMING IN WHILE TRAVEL IS BUSIEST TUESDAY
MORNING. THE OTHER ISSUE LATE MONDAY NIGHT INTO TUESDAY MORNING WILL
BE THE STRONG LLJ ADVERTISED BY THE 12Z ECMWF/GFS...AND THE WIND
FLOW AT THE SFC BEING MORE SE. THIS COULD BE A SETUP FOR HIGHER
GUSTS INTO THE MTN EMPIRE OF SW VA AS WELL AS INTO PORTIONS OF SRN
MERCER COUNTY. ATTM...WILL KEEP IT BELOW ADVISORY LEVELS BUT HAVE
MENTIONED POTENTIAL HIGHER GUSTS IN THE HWO. PRECIP/CLOUDS MAY BE
ENOUGH TO LIMIT SOME OF THE MOMENTUM TRANSFER.
TUESDAY...ANY WINTRY PRECIP SHOULD BE GONE BY LATE MORNING WITH THE
SFC LOW PUSHING ACROSS CENTRAL NC BUT COLDER POCKETS ALOFT WITH THE
ENERGETIC SHORTWAVE COULD SPIT OUT SOME SLEET WITH THE HEAVIER RAINS
INTO MIDDAY.
THE AIRMASS SHOULD START TO DRY OUT FROM SOUTHWEST TO NORTHEAST LATE
TUESDAY AFTN WITH AREA WIDE RAIN MAINLY OCCURRING FROM TUESDAY
MORNING IN THE WEST TO LATE AFTN IN THE NE. COLDER AIR ALOFT AND
WRAPPING IN BEHIND THE UPPER SHORTWAVE WILL CHANGE ANY PRECIP ON THE
BACKSIDE TO SNOW SHOWERS...WITH MAINLY UPSLOPE SHSN GOING INTO THE
TYPICAL PLACES FROM SE WV INTO NW NC INTO TUESDAY NIGHT. THE FLOW
WEAKENS SOME INTO WED AND MOISTURE COLUMN REALLY DRIES FAST WITH
LACK OF ANY OTHER UPSTREAM SHORTWAVES...SO THIS SNOW SHOWERS EVENT
SHOULD BE LESS THAN 6 TO 8 HRS LONG...AND SCATTERED AT BEST. LOOKING
AT 1 TO 2 INCHES POSSIBLE IN THE HIGHER TERRAIN OF SE WV...MAYBE AN
INCH IN THE NC MTNS. WITH THE COLUMN DRYING AND LACK OF MOISTURE IN
THE SNOW CRYSTAL GROWTH REGION LATE TUE NIGHT...MAY SEE SOME PATCHY
FREEZING DRIZZLE.
WINDS BEHIND THIS SYSTEM WILL BE GUSTY AS THE LOW DEEPENS FROM 1002
MB TUE AFTN ACROSS NC TO 995 MB OVER THE DELMARVA BY TUESDAY EVENING
AND 989 INTO NY MIDNIGHT TUE NIGHT. 8H WINDS ARE IN THE 35-45 KNOT
RANGE...SO GUSTS SHOULD STAY JUST UNDER ADVISORY LEVELS ALTHOUGH
POTENTIAL EXISTS FOR SOME MTNS TO REACH OVER 45 MPH IN GUSTS AROUND
LATE TUESDAY EVENING.
WEDNESDAY WILL SEE DRY BUT COOL WEATHER AS SFC HIGH REMAINS OVER THE
OHIO VALLEY WITH LOW LVL THICKNESSES KEEPING THE MTNS IN THE 30S ALL
DAY WITH LOWER 40S VALLEYS TO NEAR 50 EAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 230 PM EST SUNDAY...
LONG TERM PERIOD WILL BE DOMINATED BY NORTHERN STREAM SHORT WAVES
THAT WILL SCOOT EAST THROUGH THE GREAT LAKES AND NEW ENGLAND EVERY
COUPLE OF DAYS...WITH BRIEF MODERATION OF TEMPERATURES IN ADVANCE OF
EACH SYSTEM...TO BE FOLLOWED BY BRIEF INTRUSIONS OF MODIFIED
CANADIAN AIR. BEST DYNAMICS AND MOISTURE WITH EACH SYSTEM TO REMAIN
WELL TO THE NORTH AND WEST OF THE BLACKSBURG FORECAST AREA SUCH THAT
THREAT OF ANY LIGHT SPOTTY PRECIPITATION THROUGH THE ENTIRE LONG
TERM PERIOD WILL LARGELY BE CONFINED TO SOUTHEASTERN WV INTO THE
ALLEGHANY HIGHLANDS...AND POINTS FURTHER NORTH AND WEST.
AS WOULD BE EXPECTED...LONGER RANGE MODELS ALL HAVE A BIT DIFFERENT
TIMING AND AMPLITUDE OF EACH FAST MOVING NORTHERN STREAM SHORT
WAVE...THEREFORE SPREAD OF UNCERTAINTY FOR DAILY TEMPERATURE
FORECAST...WHICH IS STRONGLY GOVERNED BY EXTENT OF CLOUD COVER THIS
TIME OF YEAR WHEN CONSIDERING LOW SUN ANGLE...INCREASES MARKEDLY
WITH TIME BY THE END OF THE FORECAST PERIOD.
AS FAR AS SPECIFICS AT THE SURFACE...WEDNESDAY NIGHT INTO THURSDAY
NIGHT LOOKS TO BE DRY AND SEASONABLY COOL AS HIGH PRESSURE MOVES
EAST THROUGH THE AREA AND THEN OFF THE COAST ON THURSDAY AFTERNOON.
TEMPERATURES AROUND DAYBREAK THURSDAY SHOULD RANGE FROM THE MID 20S
TO LOWER 30S...WITH DAYTIME HIGHS ON THURSDAY RANGING FROM THE UPPER
30S TO MID 40S IN THE MOUNTAINS...TO AROUND 50 ACROSS THE
PIEDMONT.
NORTHERN STREAM SHORT WAVE WILL THEN RACE EAST THROUGH THE GREAT
LAKES AND NEW ENGLAND THURSDAY NIGHT INTO FRIDAY...PRECEDED BY
INCREASING SURFACE MIXING...WARM ADVECTION...AND A CANOPY OF MID AND
HIGH CLOUDS THAT SHOULD KEEP TEMPERATURES FROM FALLING BELOW
FREEZING IN MOST LOCATIONS ON THURSDAY NIGHT. DAYTIME HIGHS ON
FRIDAY SHOULD BE IN THE 40S IN THE MOUNTAINS...TO THE 50S ACROSS THE
PIEDMONT...ASSUMING THAT CLOUD CANOPY IS NOT TOO OPAQUE. SOME WARM
ADVECTION LIGHT RAIN SHOWERS MAY IMPACT THE NORTHWESTERN MOUNTAINS
ON FRIDAY...TO BE FOLLOWED BY COLD ADVECTION UPSLOPING CLOUDS AND
SPOTTY LIGHT RAIN OR SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY.
ANOTHER SURFACE HIGH PRESSURE SYSTEM WILL BRING CLEARING SKIES
SATURDAY AFTERNOON INTO SATURDAY NIGHT BEFORE NEXT UPSTREAM WAVE
BEGINS TO MAKE ITS APPROACH FROM THE WEST ON SUNDAY. SOME OF THE
MORE PROGRESSIVE MODELS...SUCH AS THE GFS...TRY TO BRING IN SOME
SPOTTY WARM ADVECTION SHOWERS INTO THE MOUNTAINS...BUT SOME OTHER
MODELS...SUCH AS THE ECMWF...DELAY ARRIVAL OF WARM ADVECTION SHOWERS
UNTIL LATER IN THE DAY OR AT NIGHT. CONSIDERING TIMING UNCERTAINTIES
FOR WHAT AGAIN LOOKS TO BE A VERY LIMITED PRECIPITATION EVENT...WILL
GO WITH A DRY FORECAST FOR NEXT SUNDAY UNTIL PRECIPITATION
THREAT...IF ANY...APPEARS TO BE WARRANTED. EVEN THEN...THERMAL
PROFILE WOULD ARGUE FOR ANOTHER WET RATHER THAN WHITE
EVENT...CONTINUING THE TREND FOR THIS WINTER THUS FAR.
AS INDICATED EARLIER...LIMITED AMPLITUDE AND FAST MOVEMENT OF
NORTHERN STREAM WAVES WILL NOT BE SUPPORTIVE OF ANY SIGNIFICANT
INTRUSIONS OF COLD AIR THROUGH THE LONG RANGE PERIOD UNLESS AN
UNEXPECTED BUCKLING OF UPPER FLOW OCCURS THAT HELPS TO DRIVE COLD
AIR FURTHER SOUTH. AS A RESULT...TEMPERATURES NEXT WEEKEND SHOULD
REMAIN RATHER MILD...MAINLY IN THE 30S AT NIGHT...WITH DAYTIME HIGHS
RANGING FROM THE UPPER 30S TO MID 40S IN THE MOUNTAINS TO THE LOWER
AND MID 50S ACROSS THE PIEDMONT.
&&
.AVIATION /04Z MONDAY THROUGH FRIDAY/...
AS OF 1050 PM EST SUNDAY...
COLD FRONT NOW ALONG THE BLUE RIDGE WILL CONTINUE TO PUSH EAST
OVERNIGHT WITH A BRIEF SURGE OF STRONG NW WINDS GUSTING TO PERHAPS
25-35 KNOTS AS IT PASSES. OTRW EXPECTING WINDS TO GRADUALLY DIMINISH
PRIOR TO DAYBREAK WITH MOSTLY CLEAR SKIES FROM THE BLUE RIDGE EAST
OVERNIGHT...AND A FILL IN OF LOWER CIGS OVER THE NW PER
APPROACHING UPPER COLD POOL AND MOISTENING UPSLOPE FLOW. HOWEVER
LATEST BUFKIT SOUNDINGS STILL SHOW QUITE A BIT OF LOW LEVEL DRY
AIR LINGERING WITH ANY LOW CLOUD CANOPY PRIMARILY CONFINED TO
AFTER MIDNIGHT...BASICALLY RIGHT ALONG THE PASSING UPPER TROF
AXIS. THEREFORE HAVE CONTINUED TO DELAY THE ONSET OF THE LOWER
CIGS AT KBLF/KLWB BY A FEW HOURS AND UPPED CEILING HEIGHTS A BIT
GIVEN THE VERY DRY ADVECTION ONGOING. OTRW STILL EXPECTING A
PERIOD OF LOW END VFR OR MVFR CEILINGS AT KBLF AND KLWB MAINLY
AFTER MIDNIGHT WITH THIS CLOUD DECK LINGERING PERHAPS INTO EARLY
OR MID MORNING MONDAY. A FEW LIGHT SNOW SHOWERS MAY ALSO OCCUR IN
THIS AREA...BUT NO RESTRICTIONS TO VISIBILITY ARE ANTICIPATED.
ELSW EXPECTING DOWNSLOPING VFR TO PREVAIL OVERNIGHT WITH JUST A
SCTD CLOUD LAYER POSSIBLE AT KBCB/KROA.
A SURFACE RIDGE WILL BUILD IN BY MONDAY WITH DIMINISHING WINDS
AND VFR CONDITIONS. WILL SEE A QUICK RETURN OF HIGH CLOUDS DURING
LATER MONDAY AFTERNOON BUT GIVEN VERY DRY AIR ANY CIGS BELOW 10K
FT SHOULD HOLD OFF UNTIL MONDAY NIGHT. CLOUDS WILL FILL IN WITH
LOWERING CEILINGS FROM WEST TO EAST ACROSS THE AREA LATER MONDAY
NIGHT WITH SOME SPOTTY LIGHT PRECIP POSSIBLE WEST OF THE TAF
SITES BY DAYBREAK TUESDAY. LOW PRESSURE CROSSING THROUGH THE
TENNESSEE VALLEY TUESDAY WILL BRING WIDESPREAD RAIN...ALONG WITH
IFR TO MVFR CEILINGS AND VISIBILITIES. SNOW IS POSSIBLE IN THE
BACK SIDE OF THIS SYSTEM IN SOUTHEAST WEST VIRGINIA TUESDAY NIGHT
BEFORE MOISTURE FADES...AND VFR RETURNS BY WEDNESDAY...WITH GOOD
FLYING CONDITIONS THEN EXPECTED THROUGH THE END OF THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH/WP
NEAR TERM...JH/PH
SHORT TERM...WP
LONG TERM...WERT
AVIATION...AMS/JH/PH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
915 PM EST SUN DEC 25 2011
.SYNOPSIS...
A FAST MOVING CLIPPER SYSTEM WILL MOVE ACROSS THE REGION FROM THE
WEST OVERNIGHT AND OFFSHORE EARLY MONDAY. HIGH PRESSURE WILL
BUILD EAST BEHIND THIS FEATURE LATE TONIGHT INTO MONDAY BEFORE
PASSING OFF THE COAST LATE MONDAY NIGHT. A DEVELOPING LOW
PRESSURE STORM SYSTEM WILL WORK NORTHEAST FROM THE GULF COAST
REGION MONDAY NIGHT...AND INTO THE MID ATLANTIC STATES ON
TUESDAY...RESULTING IN ANOTHER ROUND OF SIGNIFICANT RAINFALL FOR
MUCH OF THE AREA.
&&
.NEAR TERM /THROUGH MONDAY/...
AS OF 900 PM EST SUNDAY...
WEAK TROF AXIS ALONG THE MOUNTAINS CONTINUES TO SEPARATE MUCH LOWER
DEWPOINT AIR OVER THE FAR WEST/NORTH FROM MORE 30ISH NATURE
VALUES OVER THE EAST ATTM. HOWEVER AS THE APPROACHING 5H TROF AND
ASSOCIATED VORT LOBE SWING THRU IN THE NEXT FEW HOURS SHOULD SEE
DRIER AIR PUSH EAST AIDED BY INCREASING NW WINDS ACROSS THE
REGION. LATEST HRRR EVEN SURGES SPEEDS TO ADVISORY LEVELS NW NC
RIDGES WHILE MOST OTHER GUIDANCE CLOSE BUT BASICALLY KEEP THE HIGHER
SPEEDS ABOVE THE SHALLOW INVERSION AFTER MIDNIGHT. THUS HAVE
BUMPED UP SPEEDS TO JUST BELOW NPW THRESHOLDS OVER THE SW BUT EVEN
THERE EXPECT STRONGER GUSTS TO BE BRIEF AS THE QUICK SHOT OF 85H
COLD ADVECTION SWINGS THROUGH. HOWEVER MIXING SHOULD BE ENOUGH TO
HOLD TEMPS UP MOST SPOTS SINCE COLD ADVECTION ALOFT ALREADY
FADING LATE SO BUMPED UP TEMPS SLIGHTLY OUTSIDE THE VALLEYS
OVERNIGHT. OTHER ISSUE WITH CLOUDS AND POTENTIAL FOR A FEW SNOW
SHOWERS NW AS LOW LEVEL MOISTURE UNDER THE COLD POOL SWINGS ACROSS
AIDED BY UPSLOPE. SINCE EVENING SOUNDINGS QUITE ARID UNDER AN
INCREASINGLY MIXED COLUMN...AND LATEST MODELS INCLUDING THE HRRR/
LOCAL WRF SHOW ONLY A SHORT WINDOW OF POTENTIAL -SHSN...CUT POPS
BACK A BIT WITH ONLY SMALL CHCS CONFINED TO THE FAR NW SLOPES
AFTER MIDNIGHT. ELSW LEE CIRRUS MAY LINGER OVER THE SOUTH FOR A
FEW MORE HOURS BEFORE THE TROF ALOFT PASSES SO MORE PC FLAVOR THRU
HIGH CLOUDS THERE EARLY AND MOSTLY CLEAR OUTSIDE OF THE UPSLOPE NW
OVERNIGHT.
AS OF 200 PM EST SUNDAY...
SATELLITE IMAGES CONFIRM CANOPY OF HIGH CLOUDS ARE FINALLY PUSHING
SOUTH IN RESPONSE TO A NORTHERN STREAM SHORT WAVE PASSING THROUGH
THE GREAT LAKES THIS AFTERNOON. THE SHORT RANGE MODELS ARE IN GOOD
AGREEMENT THAT THE AXIS OF THIS UPPER LEVEL WAVE QUICKLY PASSES
THROUGH THE FORECAST AREA TONIGHT.
OUR LOCAL WRF MODEL AGREES WITH OTHER MODEL OUTPUT THAT LOW LEVEL
WINDS INCREASE TO 40-50 KTS AT 850MB TONIGHT AS THIS WAVE PASSES. AS
A RESULT...HAVE KEPT GUSTY WINDS IN THE FORECAST THROUGH THE
OVERNIGHT HOURS.
GOOD UPSLOPE FLOW ALONG THE WESTERN SLOPES TONIGHT SHOULD GENERATE
LOW CLOUDS. FORECAST SOUNDINGS...ESPECIALLY FROM THE GFS...KEEP A
SHALLOW LAYER OF MOISTURE THAN GENERATES SOME VERY LIGHT SNOW. LOCAL
WRF AND ARW-EAST WRF ALSO PRODUCE SNOW TONIGHT IN WESTERN GREENBRIER
COUNTY. THEREFORE...KEPT SMALL POPS FOR THIS REGION TONIGHT. ANY
SNOW THAT FALLS SHOULD BE VERY LIGHT CONSIDERING THE SHALLOW DEPTH
OF THE MOISTURE...AND EXPECT THE SNOW TO END BY DAYBREAK WITH SHORT
WAVE RIDGING RAPIDLY BUILDING IN FOR MONDAY...WHICH IS CONSIDERABLY
EARLIER THAN THE ARW-EAST WRF WHICH KEEPS SNOW THROUGH MONDAY
MORNING.
WINDS WILL RAPIDLY DIMINISH MONDAY AS THE AFOREMENTIONED UPPER LEVEL
SHORT WAVE RIDGE BUILDS INTO THE REGION...BRINGING MOSTLY CLEAR
SKIES...BEFORE HIGH CLOUDS INVADE THE REGION FROM THE WEST LATE IN
THE DAY IN ADVANCE OF THE NEXT SYSTEM.
DESPITE COLD AIR ADVECTION TONIGHT...LEANED TOWARD THE SLIGHTLY
WARMER GUIDANCE VALUES FOR LOWS TONIGHT WITH THE GUSTY WINDS
ANTICIPATED. FOR MONDAY...PREFERRED THE MUCH MORE CONSISTENT GFS MOS
OVER THE NAM MOS FOR HIGHS. WENT EVEN A DEGREE OR SO COLDER THAN
GUIDANCE FOR HIGHS MONDAY DUE TO LIMITED MIXING AND THE WARM BIAS OF
THE GUIDANCE OVER THE PAST SEVERAL DAYS.
&&
.SHORT TERM /MONDAY NIGHT THROUGH WEDNESDAY/...
AS OF 250 PM EST SUNDAY...
GOING TO SEE SOME DIFFERENT WEATHER ELEMENTS THIS PERIOD TO DEAL
WITH. COMPUTER MODELS STILL SHOWING THE UPPER LOW OVER THE SOUTHWEST
EJECTING NORTHEAST INTO OUR AREA TUESDAY AND INTO NEW ENGLAND BY
WEDNESDAY.
MONDAY NIGHT...MODELS ARE SIMILAR IN TIMING THE PRECIP ASIDE FROM
THE SLOWER NAM. THIS MAKES FOR THE ISSUE OF WINTRY PRECIP TYPE FOR
THIS FORECAST...AND MODEL FORECAST SOUNDINGS SUGGEST A 1 TO 3 HR
PERIOD OF A FREEZING RAIN OR SLEET POTENTIAL OVER THE NC MTNS NORTH
INTO THE NEW RIVER VALLEY...GREENBRIER VALLEY AND HIGHLANDS.
ATTM...STILL LOOKS LIKE CLOUDS MAY RACE IN FAST ENOUGH TO HALT A
DRAMATIC DROP IN TEMPS MONDAY NIGHT ALTHOUGH THE SE FLOW INTO THE
MTNS WILL HELP COOL THE COLUMN OVER THE MTNS. STILL NOT SEEING A LOT
OF COVERAGE AND/OR ACCUMULATION POTENTIAL TO WARRANT ANYTHING MORE
THAN MENTION IN THE HAZARDOUS WEATHER OUTLOOK. BUT WILL BEAR
WATCHING SINCE IT COULD BE COMING IN WHILE TRAVEL IS BUSIEST TUESDAY
MORNING. THE OTHER ISSUE LATE MONDAY NIGHT INTO TUESDAY MORNING WILL
BE THE STRONG LLJ ADVERTISED BY THE 12Z ECMWF/GFS...AND THE WIND
FLOW AT THE SFC BEING MORE SE. THIS COULD BE A SETUP FOR HIGHER
GUSTS INTO THE MTN EMPIRE OF SW VA AS WELL AS INTO PORTIONS OF SRN
MERCER COUNTY. ATTM...WILL KEEP IT BELOW ADVISORY LEVELS BUT HAVE
MENTIONED POTENTIAL HIGHER GUSTS IN THE HWO. PRECIP/CLOUDS MAY BE
ENOUGH TO LIMIT SOME OF THE MOMENTUM TRANSFER.
TUESDAY...ANY WINTRY PRECIP SHOULD BE GONE BY LATE MORNING WITH THE
SFC LOW PUSHING ACROSS CENTRAL NC BUT COLDER POCKETS ALOFT WITH THE
ENERGETIC SHORTWAVE COULD SPIT OUT SOME SLEET WITH THE HEAVIER RAINS
INTO MIDDAY.
THE AIRMASS SHOULD START TO DRY OUT FROM SOUTHWEST TO NORTHEAST LATE
TUESDAY AFTN WITH AREA WIDE RAIN MAINLY OCCURRING FROM TUESDAY
MORNING IN THE WEST TO LATE AFTN IN THE NE. COLDER AIR ALOFT AND
WRAPPING IN BEHIND THE UPPER SHORTWAVE WILL CHANGE ANY PRECIP ON THE
BACKSIDE TO SNOW SHOWERS...WITH MAINLY UPSLOPE SHSN GOING INTO THE
TYPICAL PLACES FROM SE WV INTO NW NC INTO TUESDAY NIGHT. THE FLOW
WEAKENS SOME INTO WED AND MOISTURE COLUMN REALLY DRIES FAST WITH
LACK OF ANY OTHER UPSTREAM SHORTWAVES...SO THIS SNOW SHOWERS EVENT
SHOULD BE LESS THAN 6 TO 8 HRS LONG...AND SCATTERED AT BEST. LOOKING
AT 1 TO 2 INCHES POSSIBLE IN THE HIGHER TERRAIN OF SE WV...MAYBE AN
INCH IN THE NC MTNS. WITH THE COLUMN DRYING AND LACK OF MOISTURE IN
THE SNOW CRYSTAL GROWTH REGION LATE TUE NIGHT...MAY SEE SOME PATCHY
FREEZING DRIZZLE.
WINDS BEHIND THIS SYSTEM WILL BE GUSTY AS THE LOW DEEPENS FROM 1002
MB TUE AFTN ACROSS NC TO 995 MB OVER THE DELMARVA BY TUESDAY EVENING
AND 989 INTO NY MIDNIGHT TUE NIGHT. 8H WINDS ARE IN THE 35-45 KNOT
RANGE...SO GUSTS SHOULD STAY JUST UNDER ADVISORY LEVELS ALTHOUGH
POTENTIAL EXISTS FOR SOME MTNS TO REACH OVER 45 MPH IN GUSTS AROUND
LATE TUESDAY EVENING.
WEDNESDAY WILL SEE DRY BUT COOL WEATHER AS SFC HIGH REMAINS OVER THE
OHIO VALLEY WITH LOW LVL THICKNESSES KEEPING THE MTNS IN THE 30S ALL
DAY WITH LOWER 40S VALLEYS TO NEAR 50 EAST.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
AS OF 230 PM EST SUNDAY...
LONG TERM PERIOD WILL BE DOMINATED BY NORTHERN STREAM SHORT WAVES
THAT WILL SCOOT EAST THROUGH THE GREAT LAKES AND NEW ENGLAND EVERY
COUPLE OF DAYS...WITH BRIEF MODERATION OF TEMPERATURES IN ADVANCE OF
EACH SYSTEM...TO BE FOLLOWED BY BRIEF INTRUSIONS OF MODIFIED
CANADIAN AIR. BEST DYNAMICS AND MOISTURE WITH EACH SYSTEM TO REMAIN
WELL TO THE NORTH AND WEST OF THE BLACKSBURG FORECAST AREA SUCH THAT
THREAT OF ANY LIGHT SPOTTY PRECIPITATION THROUGH THE ENTIRE LONG
TERM PERIOD WILL LARGELY BE CONFINED TO SOUTHEASTERN WV INTO THE
ALLEGHANY HIGHLANDS...AND POINTS FURTHER NORTH AND WEST.
AS WOULD BE EXPECTED...LONGER RANGE MODELS ALL HAVE A BIT DIFFERENT
TIMING AND AMPLITUDE OF EACH FAST MOVING NORTHERN STREAM SHORT
WAVE...THEREFORE SPREAD OF UNCERTAINTY FOR DAILY TEMPERATURE
FORECAST...WHICH IS STRONGLY GOVERNED BY EXTENT OF CLOUD COVER THIS
TIME OF YEAR WHEN CONSIDERING LOW SUN ANGLE...INCREASES MARKEDLY
WITH TIME BY THE END OF THE FORECAST PERIOD.
AS FAR AS SPECIFICS AT THE SURFACE...WEDNESDAY NIGHT INTO THURSDAY
NIGHT LOOKS TO BE DRY AND SEASONABLY COOL AS HIGH PRESSURE MOVES
EAST THROUGH THE AREA AND THEN OFF THE COAST ON THURSDAY AFTERNOON.
TEMPERATURES AROUND DAYBREAK THURSDAY SHOULD RANGE FROM THE MID 20S
TO LOWER 30S...WITH DAYTIME HIGHS ON THURSDAY RANGING FROM THE UPPER
30S TO MID 40S IN THE MOUNTAINS...TO AROUND 50 ACROSS THE
PIEDMONT.
NORTHERN STREAM SHORT WAVE WILL THEN RACE EAST THROUGH THE GREAT
LAKES AND NEW ENGLAND THURSDAY NIGHT INTO FRIDAY...PRECEDED BY
INCREASING SURFACE MIXING...WARM ADVECTION...AND A CANOPY OF MID AND
HIGH CLOUDS THAT SHOULD KEEP TEMPERATURES FROM FALLING BELOW
FREEZING IN MOST LOCATIONS ON THURSDAY NIGHT. DAYTIME HIGHS ON
FRIDAY SHOULD BE IN THE 40S IN THE MOUNTAINS...TO THE 50S ACROSS THE
PIEDMONT...ASSUMING THAT CLOUD CANOPY IS NOT TOO OPAQUE. SOME WARM
ADVECTION LIGHT RAIN SHOWERS MAY IMPACT THE NORTHWESTERN MOUNTAINS
ON FRIDAY...TO BE FOLLOWED BY COLD ADVECTION UPSLOPING CLOUDS AND
SPOTTY LIGHT RAIN OR SNOW SHOWERS FRIDAY NIGHT INTO SATURDAY.
ANOTHER SURFACE HIGH PRESSURE SYSTEM WILL BRING CLEARING SKIES
SATURDAY AFTERNOON INTO SATURDAY NIGHT BEFORE NEXT UPSTREAM WAVE
BEGINS TO MAKE ITS APPROACH FROM THE WEST ON SUNDAY. SOME OF THE
MORE PROGRESSIVE MODELS...SUCH AS THE GFS...TRY TO BRING IN SOME
SPOTTY WARM ADVECTION SHOWERS INTO THE MOUNTAINS...BUT SOME OTHER
MODELS...SUCH AS THE ECMWF...DELAY ARRIVAL OF WARM ADVECTION SHOWERS
UNTIL LATER IN THE DAY OR AT NIGHT. CONSIDERING TIMING UNCERTAINTIES
FOR WHAT AGAIN LOOKS TO BE A VERY LIMITED PRECIPITATION EVENT...WILL
GO WITH A DRY FORECAST FOR NEXT SUNDAY UNTIL PRECIPITATION
THREAT...IF ANY...APPEARS TO BE WARRANTED. EVEN THEN...THERMAL
PROFILE WOULD ARGUE FOR ANOTHER WET RATHER THAN WHITE
EVENT...CONTINUING THE TREND FOR THIS WINTER THUS FAR.
AS INDICATED EARLIER...LIMITED AMPLITUDE AND FAST MOVEMENT OF
NORTHERN STREAM WAVES WILL NOT BE SUPPORTIVE OF ANY SIGNIFICANT
INTRUSIONS OF COLD AIR THROUGH THE LONG RANGE PERIOD UNLESS AN
UNEXPECTED BUCKLING OF UPPER FLOW OCCURS THAT HELPS TO DRIVE COLD
AIR FURTHER SOUTH. AS A RESULT...TEMPERATURES NEXT WEEKEND SHOULD
REMAIN RATHER MILD...MAINLY IN THE 30S AT NIGHT...WITH DAYTIME HIGHS
RANGING FROM THE UPPER 30S TO MID 40S IN THE MOUNTAINS TO THE LOWER
AND MID 50S ACROSS THE PIEDMONT.
&&
.AVIATION /01Z MONDAY THROUGH FRIDAY/...
AS OF 610 PM EST SUNDAY...
EARLIER SHIELD OF HIGH CLDNS HAS SHIFTED TO THE SE OF THE AREA
THIS EVENING AHEAD OF THE COLD FRONT PRESSING SE THRU THE
APPALACHIANS. THIS SHOULD MAKE FOR A PERIOD OF CLEAR SKIES EARLY
THIS EVENING BEFORE DEEPENING NW FLOW IN THE WAKE OF THE FRONT
POSSIBLY DEVELOPS A BAND OF LOW CLOUDS ALONG THE NW SLOPES TOWARD
MIDNIGHT. HOWEVER LATEST BUFKIT SOUNDINGS SHOW QUITE A BIT OF LOW
LEVEL DRY AIR LINGERING WITH ANY LOW CLOUD CANOPY PRIMARILY
CONFINED TO AFTER MIDNIGHT...BASICALLY RIGHT ALONG THE PASSING
UPPER TROF AXIS. THEREFORE HAVE DELAYED THE ONSET OF THE LOWER
CIGS AT KBLF/KLWB BY A FEW HOURS AND UPPED CEILING HEIGHTS A BIT
GIVEN THE VERY DRY ADVECTION ONGOING. OTRW STILL EXPECTING A
PERIOD OF MVFR CEILINGS AT KBLF AND KLWB MAINLY AFTER MIDNIGHT
WITH THIS CLOUD DECK LINGERING PERHAPS INTO EARLY OR MID MORNING
MONDAY. A FEW LIGHT SNOW SHOWERS MAY ALSO OCCUR IN THIS
AREA...BUT NO RESTRICTIONS TO VISIBILITY ARE ANTICIPATED. ELSW
EXPECTING DOWNSLOPING VFR TO PREVAIL OVERNIGHT WITH JUST A SCTD
CLOUD LAYER POSSIBLE AT KBCB/KROA ALONG WITH STRONG NW WINDS
GUSTING TO BETTER THAN 25 KTS AT TIMES ESPCLY ALONG THE RIDGES.
A SURFACE RIDGE WILL BUILD IN BY MONDAY WITH DIMINISHING WINDS
AND VFR CONDITIONS. WILL SEE A QUICK RETURN OF HIGH CLOUDS DURING
LATER MONDAY AFTERNOON BUT GIVEN VERY DRY AIR ANY CIGS BELOW 10K
FT SHOULD HOLD OFF UNTIL MONDAY NIGHT. CLOUDS WILL FILL IN WITH
LOWERING CEILINGS FROM WEST TO EAST ACROSS THE AREA LATER MONDAY
NIGHT WITH SOME SPOTTY LIGHT PRECIP POSSIBLE WEST OF THE TAF
SITES BY DAYBREAK TUESDAY. LOW PRESSURE CROSSING THROUGH THE
TENNESSEE VALLEY TUESDAY WILL BRING WIDESPREAD RAIN...ALONG WITH
IFR TO MVFR CEILINGS AND VISIBILITIES. SNOW IS POSSIBLE IN THE
BACK SIDE OF THIS SYSTEM IN SOUTHEAST WEST VIRGINIA TUESDAY NIGHT
BEFORE MOISTURE FADES...AND VFR RETURNS BY WEDNESDAY...WITH GOOD
FLYING CONDITIONS THEN EXPECTED THROUGH THE END OF THE WEEK.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS/JH/WP
NEAR TERM...JH/PH
SHORT TERM...WP
LONG TERM...WERT
AVIATION...AMS/JH/PH
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
1255 PM EST SAT DEC 24 2011
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND
BRINGING CLEARING SKIES AND SEASONABLY COOL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1250 PM EST SATURDAY...
HIGH PRESSURE WILL MOVE ACROSS THE REGION THIS AFTERNOON AND
TONIGHT. THIS HIGH WILL KEEP THE AIR CHILLY WHILE ADVECTING IN DRIER
AIR. MID DECK CLOUDS IN SOUTHEASTERN WEST VIRGINIA WITHERING AWAY
WHILE THIN CIRRUS ENTERS THE SOUTH IN ZONAL FLOW.
LINGERING CLOUD DECK ON WESTERN SLOPES KEEPING TEMPERATURES COOLER
THAN PREVIOUSLY FORECASTED. LOWERED SOME MOUNTAIN TEMPERATURES
DOWN INTO THE UPPER 30S.
PREVIOUS DISCUSSION...AS OF 935 AM EST SATURDAY...FROM THIS
MORNINGS RNK SOUNDING...MOISTURE IS CONFIDED TO A LAYER BETWEEN
5-6KFT. AS DRIER AIR ENTERS THE AREA THIS AFTERNOON...THIS
MOISTURE/CLOUD DECK WILL WITHER AWAY. COLD HIGH PRESSURE WILL
SKIRT ACROSS THE REGION THIS AFTERNOON AND TONIGHT. 85H
TEMPERATURES WARM A FEW DEGREES BUT NOT ENOUGH TO TAKE THE CHILL
OUT OF THE AIR. MOUNTAIN TEMPERATURES WILL RANGE FROM THE M/U 40S
AND L/M 50S EAST. THESE TEMPERATURES ARE AROUND 5F ABOVE
NORMAL...WESTERN SLOPES NEAR NORMAL.
PREVIOUS DISCUSSION...AS OF 635 AM EST SATURDAY...SHORT WAVE WAS
CROSSING INTO NY. AT THE SURFACE WINDS IN THE WESTERN COUNTY
WARNING AREA HAVE COME AROUND TO THE NORTHWEST. LOW CLOUDS STILL
COVERED MUCH OF THE AREA WEST OF THE BLUE RIDGE WITH WITH SOME
BREAKS BEHIND THE THE PASSAGE OF THE UPPER SHORT WAVE. RADAR
CONTINUED TO DETECT WIDELY SCATTERED RAIN AND SNOW SHOWERS ACROSS
SOUTHEAST WEST VIRGINIA AND THE NEW RIVER VALLEY.
ONCE THE TROF AXIS PASSES TO THE EAST...EXPECT COVERAGE OF SHOWERS
TO DIMINISH. MODELS STILL SHOWED SOME DIFFERENCES IN THE TIMING OF
THE CLEARING IN THE MOUNTAINS WITH THE NAM AND GRIDDED LAMP CLEARING
THE WESTERN COUNTIES OUT BY NOON AND THE SREF...GFS AND HRRR MORE
PESSIMISTIC...HOLDING SOME CLOUDS IN THROUGH EARLY AFTERNOON. HAVE
GONE WITH THE COOLER GUIDANCE UNDER THE CLOUDS AND A BLEND FOR THE
REST OF THE FORECAST AREA FOR HIGHS TODAY.
LOW LEVEL MOISTURE WILL BE GONE BY TONIGHT BUT HIGH CLOUDS WILL
STREAM ACROSS THE SOUTHERN COUNTY WARNING AREA OVERNIGHT. USED
MILDER TEMPERATURE GUIDANCE FOR LOWS IN THE SOUTH AND COOLER
GUIDANCE IN THE CLEAR AREAS IN THE NORTH.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM SATURDAY...
TRANQUIL WEATHER EXPECTED CHRISTMAS DAY WITH SURFACE HIGH PRESSURE IN
CONTROL AND TEMPS STILL RUNNING 5 TO 10F ABOVE NORMAL. HIGHS WILL
RANGE FROM MID 50S SE TO UPPER 40S NW UNDER MOSTLY SUNNY SKIES.
SURFACE HIGH REMAINS IN PLACE ALONG THE EASTERN SEABOARD ON MONDAY
WITH SIMILAR TEMPERATURE REGIME. RAPID CHANGES IN THE OFFING HOWEVER
AS THE VIGOROUS CLOSED LOW OVER THE SOUTHWEST BEGINS TO SLOWLY LIFT
OUT ONTO THE SOUTHERN PLAINS. AS IT DOES SURFACE LOW PRESSURE SPINS
UP ALONG THE GULF COAST LATER MONDAY AND THEN LIFTS RAPIDLY NORTHEAST
TOWARD THE SOUTHERN APPALACHIANS BY EARLY TUESDAY. SYSTEM SHOULD BE
PROGRESSIVE BUT A DECENT SLUG OF RAINFALL LIKELY AS LONGER RANGE
MODELS IN QUITE GOOD AGREEMENT...WITH CMC TAKING LOW WEST OF
APPALACHIAN SPINE AND GFS/EURO CLOSER TO THE MTNS. EITHER WAY
ANOTHER 0.50 TO 0.75 INCHES OF LIQUID PRECIP SEEMS LIKELY DURING
THE DAY TUESDAY WITH POTENTIALLY HIGHER AMOUNTS SIMILAR TO WHAT JUST
OCCURRED 24 TO 36 HOURS AGO. SYNOPTIC SETUP HAS NO BLOCKING HIGH
WHATSOEVER OVER NEW ENGLAND AND HENCE LITTLE OPPORTUNITY FOR A CAD
SITUATION. VARIOUS THICKNESS PARAMETERS INDICATE AN ALL RAIN EVENT
EXCEPT FOR THE TAIL END UPSLOPE PHASE AFTER THE SURFACE LOW PASSES
AND COLDER AIR SURGES SOUTHEAST BEHIND ON TUESDAY EVENING WITH H85
TEMPS FALLING OFF TO -6C OR SO IN THE WEST AND WINDS INCREASING OUT
OF THE NW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 252 PM EST FRIDAY...
MEDIUM RANGE PERIOD CHARACTERIZED BY A SLIGHT CHANGE IN LARGE SCALE
FLOW PATTERN...FROM THE BATTLE BETWEEN NORTHERN AND SOUTHERN STREAM
ENERGY THAT WE`VE BEEN DEALING WITH PAST COUPLE OF WEEKS TO
TRANSITION TO MORE NORTHERN STREAM DOMINATED PATTERN WITH FAST
MOVING RELATIVELY DRY SHORT WAVES BUT ONLY SLIGHTLY COOLER TEMPS.
STILL NO SIGNS OF ARCTIC AIR MASS INTRUSION THROUGH THE END OF THE
YEAR.
AS FAR AS DETAILS...MOST MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
TIMING OF LAST MAJOR PIECE OF ENERGY FINALLY LIFTING OUT OF SW U.S.
EARLY NEXT WEEK AND OVER APPALACHIAN REGION BY TUESDAY. HPC IS
LEANING TOWARD THE SLOWER SOLN OF 12Z CANADIAN SUPPORTED ALSO BY
ECMWF ENSEMBLES...WHICH MAKES SENSE GIVEN TYPICAL MODEL BIASES
LIFTING MAJOR ENERGY OUT OF A CLOSED SOUTHERN STREAM LOW.
STILL...WITH 12Z GFS AND NEW 12Z ECMWF A BIT FASTER...CAN RULE OUT
SOME PRECIP REACHING THE CWA BY OVERNIGHT MONDAY NIGHT...SO WENT
WITH SLIGHT CHC AND ABOVE GUIDANCE ON MIN TEMPS WITH INCREASING
CLOUD COVER IN WARM ADVECTION.
IN SOME WAYS THIS SYSTEM LOOKS MUCH LIKE THE ONE THAT WENT
THROUGH THURSDAY NIGHT...SO SHOULD BE A STRONG FRONT WITH GOOD
MOISTURE TAP FROM GULF...AND ALSO LOOKS LIKE GOOD LOW LEVEL
SOUTHERLY JET JUST OUT AHEAD OF THE FRONT. TIMING REMAINS THE
BIGGEST QUESTION...BUT TO REMAIN CONSISTENT WITH BEST GUESS TIMING
OF TUESDAY AFTERNOON TIMING...I INCREASED WINDS AND GUSTS ALONG
HIGHER RIDGES BOTH AHEAD OF FRONT MONDAY NIGHT AND BEHIND FRONT
INTO TUES NIGHT A BIT. NW FLOW UPSLOPE MOISTURE LINGERS INTO AT
LEAST PART OF WED BUT WILL BE SHORT-LIVED WITH SHORT WAVE UPPER
RIDGE TRYING TO BUILD BACK IN.
AFTER THAT...VARIOUS WEAK SHORT WAVES IN THE NORTHERN STREAM
CONTINUE TO ALLOW FOR SOME UPSLOPE CLOUDS THROUGH THE PERIOD BUT
VERY LITTLE CHANCE AT PRECIP AS THEY APPEAR TO LACK ANY MOISTURE.
TIMING THESE AND ASSOC HIGHER CLOUDS VERY TRICKY SO SOME PARTS OF
THE THURS/FRI PERIOD WILL SEE MORE CLOUDINESS THEN
OTHERS...ESPECIALLY IN THE WEST...BUT TOO HARD TO TIME THIS FAR OUT
SO TRIED NOT TO DEPICT TOO MUCH DETAIL IN SKY COVER. SOMEWHAT
BETTER CHANCES BY FRI OR FRI NIGHT FOR A LITTLE DEEPER APPROACHING
TROUGH AND FRONTAL SYSTEM TO BRING SOME PRECIP TO APPALACHIANS AS
FLOW ACROSS MID PART OF THE COUNTRY TRIES TO SPLIT AGAIN...SO ADDED
SLIGHT CHC POPS IN THE WEST FRI AND ENTIRE CWA FRI NIGHT...BUT THIS
MAY HOLD OFF UNTIL SATURDAY IF NEW SLOWER ECMWF IS RIGHT. ALL OF
THIS WOULD BE LIQUID PRECIP.
&&
.AVIATION /18Z SATURDAY THROUGH THURSDAY/...
AS OF 1235 PM EST SATURDAY...
A FEW WESTERN SLOPE OBSERVATION SITES HANGING ON TO MVFR CEILING
LATE THIS MORNING PARTICULARLY BLF. DRY HIGH PRESSURE WILL CONTINUE
TO ERODE THESE CLOUDS THROUGH THE AFTERNOON. ALL SITES WILL HAVE VFR
CONDITIONS TONIGHT INTO SUNDAY. ALONG THE VA/NC BORDER SOUTH...SOME
HIGH CLOUDS MAY INVADE THE AREA IN ZONAL FLOW.
FOLLOWING A DRY FRONTAL PASSAGE SUNDAY NIGHT...A SURFACE RIDGE
WILL BUILD IN ON MONDAY. VFR CONDITIONS EXPECTED INTO MONDAY
NIGHT...THEN LOWER AS A DISTURBANCE TRACKS WEST OF THE AREA AND INTO
THE OHIO VALLEY TUESDAY. VFR CONDITIONS WILL RETURN TO THE AREA
WEDNESDAY AND MAY LAST FOR THE REST OF THE YEAR.
&&
.HYDROLOGY...
AS OF 330 AM SATURDAY...
TUESDAY RAINFALL EVENT PRODUCING LESS THAN AN INCH OF RAINFALL SEEMS
UNLIKELY TO PRODUCE ANY FLOODING ALTHOUGH A FEW MINOR PROBLEMS
CANNOT BE RULED OUT. RIVERS AND STREAMS ARE CURRENTLY RUNNING QUITE
HIGH...MOST ARE ABOVE THE 90TH PERCENTILE OF ALL FLOWS FOR THE DATE.
SOILS ARE BECOMING SOMEWHAT SATURATED BY WHAT HAS BECOME A FAIRLY
WET MONTH IN PARTS OF THE AREA. DECEMBER PRECIPITATION...BASICALLY
ALL OF IT LIQUID...IN THE MOUNTAINS NOW RANGES FROM ABOUT 4 TO 6
INCHES WITH NUMEROUS SITES RECEIVING IN EXCESS OF 6 INCHES AND THE
COOP PRECIPITATION SITE AT MEADOWS OF DAN OVER 9 INCHES SO FAR THIS
MONTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/RCS
SHORT TERM...PC
LONG TERM...SK
AVIATION...AMS/RCS
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
939 AM EST SAT DEC 24 2011
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND
BRINGING CLEARING SKIES AND SEASONABLY COOL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM EST SATURDAY...
FROM THIS MORNINGS RNK SOUNDING...MOISTURE IS CONFIDED TO A LAYER
BETWEEN 5-6KFT. AS DRIER AIR ENTERS THE AREA THIS
AFTERNOON...THIS MOISTURE/CLOUD DECK WILL WITHER AWAY. COLD HIGH
PRESSURE WILL SKIRT ACROSS THE REGION THIS AFTERNOON AND TONIGHT.
85H TEMPERATURES WARM A FEW DEGREES BUT NOT ENOUGH TO TAKE THE
CHILL OUT OF THE AIR. MOUNTAIN TEMPERATURES WILL RANGE FROM THE
M/U 40S AND L/M 50S EAST. THESE TEMPERATURES ARE AROUND 5F ABOVE
NORMAL...WESTERN SLOPES NEAR NORMAL.
PREVIOUS DISCUSSION...AS OF 635 AM EST SATURDAY...
SHORT WAVE WAS CROSSING INTO NY. AT THE SURFACE WINDS IN THE
WESTERN COUNTY WARNING AREA HAVE COME AROUND TO THE NORTHWEST. LOW
CLOUDS STILL COVERED MUCH OF THE AREA WEST OF THE BLUE RIDGE WITH
WITH SOME BREAKS BEHIND THE THE PASSAGE OF THE UPPER SHORT WAVE.
RADAR CONTINUED TO DETECT WIDELY SCATTERED RAIN AND SNOW SHOWERS
ACROSS SOUTHEAST WEST VIRGINIA AND THE NEW RIVER VALLEY.
ONCE THE TROF AXIS PASSES TO THE EAST...EXPECT COVERAGE OF SHOWERS
TO DIMINISH. MODELS STILL SHOWED SOME DIFFERENCES IN THE TIMING OF
THE CLEARING IN THE MOUNTAINS WITH THE NAM AND GRIDDED LAMP CLEARING
THE WESTERN COUNTIES OUT BY NOON AND THE SREF...GFS AND HRRR MORE
PESSIMISTIC...HOLDING SOME CLOUDS IN THROUGH EARLY AFTERNOON. HAVE
GONE WITH THE COOLER GUIDANCE UNDER THE CLOUDS AND A BLEND FOR THE
REST OF THE FORECAST AREA FOR HIGHS TODAY.
LOW LEVEL MOISTURE WILL BE GONE BY TONIGHT BUT HIGH CLOUDS WILL
STREAM ACROSS THE SOUTHERN COUNTY WARNING AREA OVERNIGHT. USED
MILDER TEMPERATURE GUIDANCE FOR LOWS IN THE SOUTH AND COOLER
GUIDANCE IN THE CLEAR AREAS IN THE NORTH.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM SATURDAY...
TRANQUIL WEATHER EXPECTED CHRISTMAS DAY WITH SURFACE HIGH PRESSURE IN
CONTROL AND TEMPS STILL RUNNING 5 TO 10F ABOVE NORMAL. HIGHS WILL
RANGE FROM MID 50S SE TO UPPER 40S NW UNDER MOSTLY SUNNY SKIES.
SURFACE HIGH REMAINS IN PLACE ALONG THE EASTERN SEABOARD ON MONDAY
WITH SIMILAR TEMPERATURE REGIME. RAPID CHANGES IN THE OFFING HOWEVER
AS THE VIGOROUS CLOSED LOW OVER THE SOUTHWEST BEGINS TO SLOWLY LIFT
OUT ONTO THE SOUTHERN PLAINS. AS IT DOES SURFACE LOW PRESSURE SPINS
UP ALONG THE GULF COAST LATER MONDAY AND THEN LIFTS RAPIDLY NORTHEAST
TOWARD THE SOUTHERN APPALACHIANS BY EARLY TUESDAY. SYSTEM SHOULD BE
PROGRESSIVE BUT A DECENT SLUG OF RAINFALL LIKELY AS LONGER RANGE
MODELS IN QUITE GOOD AGREEMENT...WITH CMC TAKING LOW WEST OF
APPALACHIAN SPINE AND GFS/EURO CLOSER TO THE MTNS. EITHER WAY
ANOTHER 0.50 TO 0.75 INCHES OF LIQUID PRECIP SEEMS LIKELY DURING
THE DAY TUESDAY WITH POTENTIALLY HIGHER AMOUNTS SIMILAR TO WHAT JUST
OCCURRED 24 TO 36 HOURS AGO. SYNOPTIC SETUP HAS NO BLOCKING HIGH
WHATSOEVER OVER NEW ENGLAND AND HENCE LITTLE OPPORTUNITY FOR A CAD
SITUATION. VARIOUS THICKNESS PARAMETERS INDICATE AN ALL RAIN EVENT
EXCEPT FOR THE TAIL END UPSLOPE PHASE AFTER THE SURFACE LOW PASSES
AND COLDER AIR SURGES SOUTHEAST BEHIND ON TUESDAY EVENING WITH H85
TEMPS FALLING OFF TO -6C OR SO IN THE WEST AND WINDS INCREASING OUT
OF THE NW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 252 PM EST FRIDAY...
MEDIUM RANGE PERIOD CHARACTERIZED BY A SLIGHT CHANGE IN LARGE SCALE
FLOW PATTERN...FROM THE BATTLE BETWEEN NORTHERN AND SOUTHERN STREAM
ENERGY THAT WE`VE BEEN DEALING WITH PAST COUPLE OF WEEKS TO
TRANSITION TO MORE NORTHERN STREAM DOMINATED PATTERN WITH FAST
MOVING RELATIVELY DRY SHORT WAVES BUT ONLY SLIGHTLY COOLER TEMPS.
STILL NO SIGNS OF ARCTIC AIR MASS INTRUSION THROUGH THE END OF THE
YEAR.
AS FAR AS DETAILS...MOST MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
TIMING OF LAST MAJOR PIECE OF ENERGY FINALLY LIFTING OUT OF SW U.S.
EARLY NEXT WEEK AND OVER APPALACHIAN REGION BY TUESDAY. HPC IS
LEANING TOWARD THE SLOWER SOLN OF 12Z CANADIAN SUPPORTED ALSO BY
ECMWF ENSEMBLES...WHICH MAKES SENSE GIVEN TYPICAL MODEL BIASES
LIFTING MAJOR ENERGY OUT OF A CLOSED SOUTHERN STREAM LOW.
STILL...WITH 12Z GFS AND NEW 12Z ECMWF A BIT FASTER...CAN RULE OUT
SOME PRECIP REACHING THE CWA BY OVERNIGHT MONDAY NIGHT...SO WENT
WITH SLIGHT CHC AND ABOVE GUIDANCE ON MIN TEMPS WITH INCREASING
CLOUD COVER IN WARM ADVECTION.
IN SOME WAYS THIS SYSTEM LOOKS MUCH LIKE THE ONE THAT WENT
THROUGH THURSDAY NIGHT...SO SHOULD BE A STRONG FRONT WITH GOOD
MOISTURE TAP FROM GULF...AND ALSO LOOKS LIKE GOOD LOW LEVEL
SOUTHERLY JET JUST OUT AHEAD OF THE FRONT. TIMING REMAINS THE
BIGGEST QUESTION...BUT TO REMAIN CONSISTENT WITH BEST GUESS TIMING
OF TUESDAY AFTERNOON TIMING...I INCREASED WINDS AND GUSTS ALONG
HIGHER RIDGES BOTH AHEAD OF FRONT MONDAY NIGHT AND BEHIND FRONT
INTO TUES NIGHT A BIT. NW FLOW UPSLOPE MOISTURE LINGERS INTO AT
LEAST PART OF WED BUT WILL BE SHORT-LIVED WITH SHORT WAVE UPPER
RIDGE TRYING TO BUILD BACK IN.
AFTER THAT...VARIOUS WEAK SHORT WAVES IN THE NORTHERN STREAM
CONTINUE TO ALLOW FOR SOME UPSLOPE CLOUDS THROUGH THE PERIOD BUT
VERY LITTLE CHANCE AT PRECIP AS THEY APPEAR TO LACK ANY MOISTURE.
TIMING THESE AND ASSOC HIGHER CLOUDS VERY TRICKY SO SOME PARTS OF
THE THURS/FRI PERIOD WILL SEE MORE CLOUDINESS THEN
OTHERS...ESPECIALLY IN THE WEST...BUT TOO HARD TO TIME THIS FAR OUT
SO TRIED NOT TO DEPICT TOO MUCH DETAIL IN SKY COVER. SOMEWHAT
BETTER CHANCES BY FRI OR FRI NIGHT FOR A LITTLE DEEPER APPROACHING
TROUGH AND FRONTAL SYSTEM TO BRING SOME PRECIP TO APPALACHIANS AS
FLOW ACROSS MID PART OF THE COUNTRY TRIES TO SPLIT AGAIN...SO ADDED
SLIGHT CHC POPS IN THE WEST FRI AND ENTIRE CWA FRI NIGHT...BUT THIS
MAY HOLD OFF UNTIL SATURDAY IF NEW SLOWER ECMWF IS RIGHT. ALL OF
THIS WOULD BE LIQUID PRECIP.
&&
.AVIATION /15Z SATURDAY THROUGH WEDNESDAY/...
AS OF 635 AM EST SATURDAY...
MVFR CEILINGS IN THE WESTERN UPSLOPE AREAS...BLF/LWB...WERE
STARING TO ERODE. WEAKENING UPSLOPE WILL RESULT IN CEILINGS
BECOMING SCATTERED AND LIFTING TO VFR BY 18Z. NO CEILING
RESTRICTIONS ARE EXPECTED AT KROA...KLYH...AND KDAN. MODERATE
CONFIDENCE ON THE TIMING OF THE IMPROVING CONDITIONS AT BLF AND
LWB.
VFR CONDITIONS ARE EXPECTED ACROSS THE ENTIRE TERMINAL FORECAST
AREA TONIGHT INTO SUNDAY. HIGH CLOUDS ARE EXPECTED ACROSS SOUTHERN
VIRGINIA AND NORTH CAROLINA THIS AFTERNOON AND TONIGHT.
THERE IS A POSSIBILITY OF A BRIEF RETURN TO UPSLOPING CLOUDS
ACROSS THE WESTERN FLANKS OF THE APPALACHIANS (KBLF AND KLWB) ON
SUNDAY NIGHT.
A SURFACE RIDGE WILL BUILD IN ON MONDAY...ALONG WITH VFR
CONDITIONS UNTIL NEXT SOUTHERN STREAM WAVE RESULTS IN AN
INCREASING THREAT FOR RAIN AND ASSOCIATED FLIGHT RESTRICTIONS DOWN
INTO THE MVFR OR IFR RANGE MONDAY NIGHT INTO TUESDAY.
&&
.HYDROLOGY...
AS OF 330 AM SATURDAY...
TUESDAY RAINFALL EVENT PRODUCING LESS THAN AN INCH OF RAINFALL SEEMS
UNLIKELY TO PRODUCE ANY FLOODING ALTHOUGH A FEW MINOR PROBLEMS
CANNOT BE RULED OUT. RIVERS AND STREAMS ARE CURRENTLY RUNNING QUITE
HIGH...MOST ARE ABOVE THE 90TH PERCENTILE OF ALL FLOWS FOR THE DATE.
SOILS ARE BECOMING SOMEWHAT SATURATED BY WHAT HAS BECOME A FAIRLY
WET MONTH IN PARTS OF THE AREA. DECEMBER PRECIPITATION...BASICALLY
ALL OF IT LIQUID...IN THE MOUNTAINS NOW RANGES FROM ABOUT 4 TO 6
INCHES WITH NUMEROUS SITES RECEIVING IN EXCESS OF 6 INCHES AND THE
COOP PRECIPITATION SITE AT MEADOWS OF DAN OVER 9 INCHES SO FAR THIS
MONTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS/RCS
SHORT TERM...PC
LONG TERM...SK
AVIATION...AMS
HYDROLOGY...
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
639 AM EST SAT DEC 24 2011
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND
BRINGING CLEARING SKIES AND SEASONABLY COOL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 635 AM EST SATURDAY...
SHORT WAVE WAS CROSSING INTO NY. AT THE SURFACE WINDS IN THE
WESTERN COUNTY WARNING AREA HAVE COME AROUND TO THE NORTHWEST.
LOW CLOUDS STILL COVERED MUCH OF THE AREA WEST OF THE BLUE RIDGE
WITH WITH SOME BREAKS BEHIND THE THE PASSAGE OF THE UPPER SHORT
WAVE. RADAR CONTINUED TO DETECT WIDELY SCATTERED RAIN AND SNOW
SHOWERS ACROSS SOUTHEAST WEST VIRGINIA AND THE NEW RIVER VALLEY.
ONCE THE TROF AXIS PASSES TO THE EAST...EXPECT COVERAGE OF SHOWERS
TO DIMINISH. MODELS STILL SHOWED SOME DIFFERENCES IN THE TIMING OF
THE CLEARING IN THE MOUNTAINS WITH THE NAM AND GRIDDED LAMP CLEARING
THE WESTERN COUNTIES OUT BY NOON AND THE SREF...GFS AND HRRR MORE
PESSIMISTIC...HOLDING SOME CLOUDS IN THROUGH EARLY AFTERNOON. HAVE
GONE WITH THE COOLER GUIDANCE UNDER THE CLOUDS AND A BLEND FOR THE
REST OF THE FORECAST AREA FOR HIGHS TODAY.
LOW LEVEL MOISTURE WILL BE GONE BY TONIGHT BUT HIGH CLOUDS WILL
STREAM ACROSS THE SOUTHERN COUNTY WARNING AREA OVERNIGHT. USED
MILDER TEMPERATURE GUIDANCE FOR LOWS IN THE SOUTH AND COOLER
GUIDANCE IN THE CLEAR AREAS IN THE NORTH.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM SATURDAY...
TRANQUIL WEATHER EXPECTED CHRISTMAS DAY WITH SURFACE HIGH PRESSURE IN
CONTROL AND TEMPS STILL RUNNING 5 TO 10F ABOVE NORMAL. HIGHS WILL
RANGE FROM MID 50S SE TO UPPER 40S NW UNDER MOSTLY SUNNY SKIES.
SURFACE HIGH REMAINS IN PLACE ALONG THE EASTERN SEABOARD ON MONDAY
WITH SIMILAR TEMPERATURE REGIME. RAPID CHANGES IN THE OFFING HOWEVER
AS THE VIGOROUS CLOSED LOW OVER THE SOUTHWEST BEGINS TO SLOWLY LIFT
OUT ONTO THE SOUTHERN PLAINS. AS IT DOES SURFACE LOW PRESSURE SPINS
UP ALONG THE GULF COAST LATER MONDAY AND THEN LIFTS RAPIDLY NORTHEAST
TOWARD THE SOUTHERN APPALACHIANS BY EARLY TUESDAY. SYSTEM SHOULD BE
PROGRESSIVE BUT A DECENT SLUG OF RAINFALL LIKELY AS LONGER RANGE
MODELS IN QUITE GOOD AGREEMENT...WITH CMC TAKING LOW WEST OF
APPALACHIAN SPINE AND GFS/EURO CLOSER TO THE MTNS. EITHER WAY
ANOTHER 0.50 TO 0.75 INCHES OF LIQUID PRECIP SEEMS LIKELY DURING
THE DAY TUESDAY WITH POTENTIALLY HIGHER AMOUNTS SIMILAR TO WHAT JUST
OCCURRED 24 TO 36 HOURS AGO. SYNOPTIC SETUP HAS NO BLOCKING HIGH
WHATSOEVER OVER NEW ENGLAND AND HENCE LITTLE OPPORTUNITY FOR A CAD
SITUATION. VARIOUS THICKNESS PARAMETERS INDICATE AN ALL RAIN EVENT
EXCEPT FOR THE TAIL END UPSLOPE PHASE AFTER THE SURFACE LOW PASSES
AND COLDER AIR SURGES SOUTHEAST BEHIND ON TUESDAY EVENING WITH H85
TEMPS FALLING OFF TO -6C OR SO IN THE WEST AND WINDS INCREASING OUT
OF THE NW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 252 PM EST FRIDAY...
MEDIUM RANGE PERIOD CHARACTERIZED BY A SLIGHT CHANGE IN LARGE SCALE
FLOW PATTERN...FROM THE BATTLE BETWEEN NORTHERN AND SOUTHERN STREAM
ENERGY THAT WE`VE BEEN DEALING WITH PAST COUPLE OF WEEKS TO
TRANSITION TO MORE NORTHERN STREAM DOMINATED PATTERN WITH FAST
MOVING RELATIVELY DRY SHORT WAVES BUT ONLY SLIGHTLY COOLER TEMPS.
STILL NO SIGNS OF ARCTIC AIR MASS INTRUSION THROUGH THE END OF THE
YEAR.
AS FAR AS DETAILS...MOST MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
TIMING OF LAST MAJOR PIECE OF ENERGY FINALLY LIFTING OUT OF SW U.S.
EARLY NEXT WEEK AND OVER APPALACHIAN REGION BY TUESDAY. HPC IS
LEANING TOWARD THE SLOWER SOLN OF 12Z CANADIAN SUPPORTED ALSO BY
ECMWF ENSEMBLES...WHICH MAKES SENSE GIVEN TYPICAL MODEL BIASES
LIFTING MAJOR ENERGY OUT OF A CLOSED SOUTHERN STREAM LOW.
STILL...WITH 12Z GFS AND NEW 12Z ECMWF A BIT FASTER...CAN RULE OUT
SOME PRECIP REACHING THE CWA BY OVERNIGHT MONDAY NIGHT...SO WENT
WITH SLIGHT CHC AND ABOVE GUIDANCE ON MIN TEMPS WITH INCREASING
CLOUD COVER IN WARM ADVECTION.
IN SOME WAYS THIS SYSTEM LOOKS MUCH LIKE THE ONE THAT WENT
THROUGH THURSDAY NIGHT...SO SHOULD BE A STRONG FRONT WITH GOOD
MOISTURE TAP FROM GULF...AND ALSO LOOKS LIKE GOOD LOW LEVEL
SOUTHERLY JET JUST OUT AHEAD OF THE FRONT. TIMING REMAINS THE
BIGGEST QUESTION...BUT TO REMAIN CONSISTENT WITH BEST GUESS TIMING
OF TUESDAY AFTERNOON TIMING...I INCREASED WINDS AND GUSTS ALONG
HIGHER RIDGES BOTH AHEAD OF FRONT MONDAY NIGHT AND BEHIND FRONT
INTO TUES NIGHT A BIT. NW FLOW UPSLOPE MOISTURE LINGERS INTO AT
LEAST PART OF WED BUT WILL BE SHORT-LIVED WITH SHORT WAVE UPPER
RIDGE TRYING TO BUILD BACK IN.
AFTER THAT...VARIOUS WEAK SHORT WAVES IN THE NORTHERN STREAM
CONTINUE TO ALLOW FOR SOME UPSLOPE CLOUDS THROUGH THE PERIOD BUT
VERY LITTLE CHANCE AT PRECIP AS THEY APPEAR TO LACK ANY MOISTURE.
TIMING THESE AND ASSOC HIGHER CLOUDS VERY TRICKY SO SOME PARTS OF
THE THURS/FRI PERIOD WILL SEE MORE CLOUDINESS THEN
OTHERS...ESPECIALLY IN THE WEST...BUT TOO HARD TO TIME THIS FAR OUT
SO TRIED NOT TO DEPICT TOO MUCH DETAIL IN SKY COVER. SOMEWHAT
BETTER CHANCES BY FRI OR FRI NIGHT FOR A LITTLE DEEPER APPROACHING
TROUGH AND FRONTAL SYSTEM TO BRING SOME PRECIP TO APPALACHIANS AS
FLOW ACROSS MID PART OF THE COUNTRY TRIES TO SPLIT AGAIN...SO ADDED
SLIGHT CHC POPS IN THE WEST FRI AND ENTIRE CWA FRI NIGHT...BUT THIS
MAY HOLD OFF UNTIL SATURDAY IF NEW SLOWER ECMWF IS RIGHT. ALL OF
THIS WOULD BE LIQUID PRECIP.
&&
.AVIATION /12Z SATURDAY THROUGH WEDNESDAY/...
AS OF 635 AM EST SATURDAY...
MVFR CEILINGS IN THE WESTERN UPSLOPE AREAS...BLF/LWB...WERE
STARING TO ERODE. WEAKENING UPSLOPE WILL RESULT IN CEILINGS
BECOMING SCATTERED AND LIFTING TO VFR BY 18Z. NO CEILING
RESTRICTIONS ARE EXPECTED AT KROA...KLYH...AND KDAN. MODERATE
CONFIDENCE ON THE TIMING OF THE IMPROVING CONDITIONS AT BLF AND
LWB.
VFR CONDITIONS ARE EXPECTED ACROSS THE ENTIRE TERMINAL FORECAST
AREA TONIGHT INTO SUNDAY. HIGH CLOUDS ARE EXPECTED ACROSS SOUTHERN
VIRGINIA AND NORTH CAROLINA THIS AFTERNOON AND TONIGHT.
THERE IS A POSSIBILITY OF A BRIEF RETURN TO UPSLOPING CLOUDS
ACROSS THE WESTERN FLANKS OF THE APPALACHIANS (KBLF AND KLWB) ON
SUNDAY NIGHT.
A SURFACE RIDGE WILL BUILD IN ON MONDAY...ALONG WITH VFR
CONDITIONS UNTIL NEXT SOUTHERN STREAM WAVE RESULTS IN AN
INCREASING THREAT FOR RAIN AND ASSOCIATED FLIGHT RESTRICTIONS DOWN
INTO THE MVFR OR IFR RANGE MONDAY NIGHT INTO TUESDAY.
&&
.HYDROLOGY...
AS OF 330 AM SATURDAY...
TUESDAY RAINFALL EVENT PRODUCING LESS THAN AN INCH OF RAINFALL SEEMS
UNLIKELY TO PRODUCE ANY FLOODING ALTHOUGH A FEW MINOR PROBLEMS
CANNOT BE RULED OUT. RIVERS AND STREAMS ARE CURRENTLY RUNNING QUITE
HIGH...MOST ARE ABOVE THE 90TH PERCENTILE OF ALL FLOWS FOR THE DATE.
SOILS ARE BECOMING SOMEWHAT SATURATED BY WHAT HAS BECOME A FAIRLY
WET MONTH IN PARTS OF THE AREA. DECEMBER PRECIPITATION...BASICALLY
ALL OF IT LIQUID...IN THE MOUNTAINS NOW RANGES FROM ABOUT 4 TO 6
INCHES WITH NUMEROUS SITES RECEIVING IN EXCESS OF 6 INCHES AND THE
COOP PRECIPITATION SITE AT MEADOWS OF DAN OVER 9 INCHES SO FAR THIS
MONTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PC
LONG TERM...SK
AVIATION...AMS
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS BLACKSBURG VA
347 AM EST SAT DEC 24 2011
.SYNOPSIS...
SURFACE HIGH PRESSURE WILL BUILD INTO THE REGION OVER THE WEEKEND
BRINGING CLEARING SKIES AND SEASONABLY COOL TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 340 AM EST SATURDAY...
SHORT WAVE WAS CROSSING INTO PA/NY, AT THE SURFACE WINDS IN THE
WESTERN COUNTY WARNING AREA HAVE COME AROUND TO THE NORTHWEST WITH
SLIGHTLY STRONGER WINDS SPEEDS. LOW CLOUDS STILL COVERED MUCH OF
THE AREA WEST OF THE BLUE RIDGE WITH CLEARING ON THE WESTERN EDGE
OF THE CLOUDS IN KENTUCKY AND WEST VIRGINIA WITH THE PASSAGE OF
THE UPPER SHORT WAVE. RADAR CONTINUED TO DETECT SCATTERED RAIN AND
SNOW SHOWERS ACROSS SOUTHEAST WEST VIRGINIA AND THE NEW RIVER
VALLEY.
ONCE THE TROF AXIS PASSES TO THE EAST...EXPECT COVERAGE OF SHOWERS
TO DIMINISH. MODELS STILL SHOWED SOME DIFFERENCES IN THE TIMING OF
THE CLEARING IN THE MOUNTAINS WITH THE NAM AND GRIDDED LAMP CLEARING
THE WESTERN COUNTIES OUT BY NOON AND THE SREF...GFS AND HRRR MORE
PESSIMISTIC...HOLDING SOME CLOUDS IN THROUGH EARLY AFTERNOON. HAVE
GONE WITH THE COOLER GUIDANCE UNDER THE CLOUDS AND A BLEND FOR THE
REST OF THE FORECAST AREA FOR HIGHS TODAY.
LOW LEVEL MOISTURE WILL BE GONE BY TONIGHT BUT HIGH CLOUDS WILL
STREAM ACROSS THE SOUTHERN COUNTY WARNING AREA OVERNIGHT. USED
MILDER TEMPERATURE GUIDANCE FOR LOWS IN THE SOUTH AND COOLER
GUIDANCE IN THE CLEAR AREAS IN THE NORTH.
&&
.SHORT TERM /SUNDAY THROUGH TUESDAY/...
AS OF 330 AM SATURDAY...
TRANQUIL WEATHER EXPECTED CHRISTMAS DAY WITH SURFACE HIGH PRESSURE IN
CONTROL AND TEMPS STILL RUNNING 5 TO 10F ABOVE NORMAL. HIGHS WILL
RANGE FROM MID 50S SE TO UPPER 40S NW UNDER MOSTLY SUNNY SKIES.
SURFACE HIGH REMAINS IN PLACE ALONG THE EASTERN SEABOARD ON MONDAY
WITH SIMILAR TEMPERATURE REGIME. RAPID CHANGES IN THE OFFING HOWEVER
AS THE VIGOROUS CLOSED LOW OVER THE SOUTHWEST BEGINS TO SLOWLY LIFT
OUT ONTO THE SOUTHERN PLAINS. AS IT DOES SURFACE LOW PRESSURE SPINS
UP ALONG THE GULF COAST LATER MONDAY AND THEN LIFTS RAPIDLY NORTHEAST
TOWARD THE SOUTHERN APPALACHIANS BY EARLY TUESDAY. SYSTEM SHOULD BE
PROGRESSIVE BUT A DECENT SLUG OF RAINFALL LIKELY AS LONGER RANGE
MODELS IN QUITE GOOD AGREEMENT...WITH CMC TAKING LOW WEST OF
APPALACHIAN SPINE AND GFS/EURO CLOSER TO THE MTNS. EITHER WAY
ANOTHER 0.50 TO 0.75 INCHES OF LIQUID PRECIP SEEMS LIKELY DURING
THE DAY TUESDAY WITH POTENTIALLY HIGHER AMOUNTS SIMILAR TO WHAT JUST
OCCURRED 24 TO 36 HOURS AGO. SYNOPTIC SETUP HAS NO BLOCKING HIGH
WHATSOEVER OVER NEW ENGLAND AND HENCE LITTLE OPPORTUNITY FOR A CAD
SITUATION. VARIOUS THICKNESS PARAMETERS INDICATE AN ALL RAIN EVENT
EXCEPT FOR THE TAIL END UPSLOPE PHASE AFTER THE SURFACE LOW PASSES
AND COLDER AIR SURGES SOUTHEAST BEHIND ON TUESDAY EVENING WITH H85
TEMPS FALLING OFF TO -6C OR SO IN THE WEST AND WINDS INCREASING OUT
OF THE NW.
&&
.LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/...
AS OF 252 PM EST FRIDAY...
MEDIUM RANGE PERIOD CHARACTERIZED BY A SLIGHT CHANGE IN LARGE SCALE
FLOW PATTERN...FROM THE BATTLE BETWEEN NORTHERN AND SOUTHERN STREAM
ENERGY THAT WE`VE BEEN DEALING WITH PAST COUPLE OF WEEKS TO
TRANSITION TO MORE NORTHERN STREAM DOMINATED PATTERN WITH FAST
MOVING RELATIVELY DRY SHORT WAVES BUT ONLY SLIGHTLY COOLER TEMPS.
STILL NO SIGNS OF ARCTIC AIR MASS INTRUSION THROUGH THE END OF THE
YEAR.
AS FAR AS DETAILS...MOST MODELS ARE IN FAIRLY GOOD AGREEMENT WITH
TIMING OF LAST MAJOR PIECE OF ENERGY FINALLY LIFTING OUT OF SW U.S.
EARLY NEXT WEEK AND OVER APPALACHIAN REGION BY TUESDAY. HPC IS
LEANING TOWARD THE SLOWER SOLN OF 12Z CANADIAN SUPPORTED ALSO BY
ECMWF ENSEMBLES...WHICH MAKES SENSE GIVEN TYPICAL MODEL BIASES
LIFTING MAJOR ENERGY OUT OF A CLOSED SOUTHERN STREAM LOW.
STILL...WITH 12Z GFS AND NEW 12Z ECMWF A BIT FASTER...CAN RULE OUT
SOME PRECIP REACHING THE CWA BY OVERNIGHT MONDAY NIGHT...SO WENT
WITH SLIGHT CHC AND ABOVE GUIDANCE ON MIN TEMPS WITH INCREASING
CLOUD COVER IN WARM ADVECTION.
IN SOME WAYS THIS SYSTEM LOOKS MUCH LIKE THE ONE THAT WENT
THROUGH THURSDAY NIGHT...SO SHOULD BE A STRONG FRONT WITH GOOD
MOISTURE TAP FROM GULF...AND ALSO LOOKS LIKE GOOD LOW LEVEL
SOUTHERLY JET JUST OUT AHEAD OF THE FRONT. TIMING REMAINS THE
BIGGEST QUESTION...BUT TO REMAIN CONSISTENT WITH BEST GUESS TIMING
OF TUESDAY AFTERNOON TIMING...I INCREASED WINDS AND GUSTS ALONG
HIGHER RIDGES BOTH AHEAD OF FRONT MONDAY NIGHT AND BEHIND FRONT
INTO TUES NIGHT A BIT. NW FLOW UPSLOPE MOISTURE LINGERS INTO AT
LEAST PART OF WED BUT WILL BE SHORT-LIVED WITH SHORT WAVE UPPER
RIDGE TRYING TO BUILD BACK IN.
AFTER THAT...VARIOUS WEAK SHORT WAVES IN THE NORTHERN STREAM
CONTINUE TO ALLOW FOR SOME UPSLOPE CLOUDS THROUGH THE PERIOD BUT
VERY LITTLE CHANCE AT PRECIP AS THEY APPEAR TO LACK ANY MOISTURE.
TIMING THESE AND ASSOC HIGHER CLOUDS VERY TRICKY SO SOME PARTS OF
THE THURS/FRI PERIOD WILL SEE MORE CLOUDINESS THEN
OTHERS...ESPECIALLY IN THE WEST...BUT TOO HARD TO TIME THIS FAR OUT
SO TRIED NOT TO DEPICT TOO MUCH DETAIL IN SKY COVER. SOMEWHAT
BETTER CHANCES BY FRI OR FRI NIGHT FOR A LITTLE DEEPER APPROACHING
TROUGH AND FRONTAL SYSTEM TO BRING SOME PRECIP TO APPALACHIANS AS
FLOW ACROSS MID PART OF THE COUNTRY TRIES TO SPLIT AGAIN...SO ADDED
SLIGHT CHC POPS IN THE WEST FRI AND ENTIRE CWA FRI NIGHT...BUT THIS
MAY HOLD OFF UNTIL SATURDAY IF NEW SLOWER ECMWF IS RIGHT. ALL OF
THIS WOULD BE LIQUID PRECIP.
&&
.AVIATION /09Z SATURDAY THROUGH WEDNESDAY/...
AS OF 1205 AM EST SATURDAY...
MOIST UPSLOPING FLOW WILL CONTINUE TO RESULT IN ABUNDANT STRATOCUMULUS
LAYER ALONG AND WEST OF THE BLUE RIDGE FOR THE REST OF THE NIGHT WITH
CEILINGS MAINLY IN THE 25-35 HUNDRED FOOT RANGE...BUT WITH SOME
LOCALIZED CEILINGS OF 10-20 HUNDRED FEET IN PREFERRED UPSLOPING
AREAS...SUCH AS NEAR KBLF.
NO CEILING RESTRICTIONS ARE EXPECTED AT KROA...KLYH...AND KDAN AS
DEPTH OF LOW LEVEL MOISTURE GRADUALLY LESSENS WITH APPROACH OF
SURFACE RIDGE.
WEAKENING UPSLOPING WINDS AND INTRUSION OF DRIER AIR IN LOWER
TROPOSPHERE WITH ARRIVAL OF SURFACE RIDGE SHOULD ALLOW FOR RETURN
TO UNRESTRICTED CEILINGS WEST OF THE BLUE RIDGE BY MID TO LATE
MORNING...ALTHOUGH FAVORED UPSLOPE AREAS SUCH AS AT/NEAR KBLF MAY
HAVE TO WAIT UNTIL EARLY AFTERNOON BEFORE LOW LEVEL CLOUDS FINALLY
BECOME CLEAR TO SCATTERED.
VFR WEATHER WITH UNRESTRICTED CONDITIONS IS EXPECTED ACROSS THE
ENTIRE TERMINAL FORECAST AREA INTO SUNDAY BEFORE NEXT SHORT WAVE
SCOOTS RAPIDLY EAST TO THE NORTH OF THE AREA...DRIVING A COLD FRONT
SOUTHEAST THROUGH THE REGION. THERE IS A POSSIBILITY OF A BRIEF
RETURN TO UPSLOPING CLOUDS ACROSS THE WESTERN FLANKS OF THE
APPALACHIANS (KBLF AND KLWB) ON SUNDAY NIGHT.
SURFACE RIDGE WILL QUICKLY BUILD IN BEHIND THIS SYSTEM ON
MONDAY...ALONG WITH VFR CONDITIONS UNTIL NEXT SOUTHERN STREAM
WAVE RESULTS IN AN INCREASING THREAT FOR RAIN AND ASSOCIATED
FLIGHT RESTRICTIONS DOWN INTO THE MVFR OR IFR RANGE MONDAY NIGHT
INTO TUESDAY.
&&
.HYDROLOGY...
AS OF 330 AM SATURDAY...
TUESDAY RAINFALL EVENT PRODUCING LESS THAN AN INCH OF RAINFALL SEEMS
UNLIKELY TO PRODUCE ANY FLOODING ALTHOUGH A FEW MINOR PROBLEMS
CANNOT BE RULED OUT. RIVERS AND STREAMS ARE CURRENTLY RUNNING QUITE
HIGH...MOST ARE ABOVE THE 90TH PERCENTILE OF ALL FLOWS FOR THE DATE.
SOILS ARE BECOMING SOMEWHAT SATURATED BY WHAT HAS BECOME A FAIRLY
WET MONTH IN PARTS OF THE AREA. DECEMBER PRECIPITATION...BASICALLY
ALL OF IT LIQUID...IN THE MOUNTAINS NOW RANGES FROM ABOUT 4 TO 6
INCHES WITH NUMEROUS SITES RECEIVING IN EXCESS OF 6 INCHES AND THE
COOP PRECIPITATION SITE AT MEADOWS OF DAN OVER 9 INCHES SO FAR THIS
MONTH.
&&
.RNK WATCHES/WARNINGS/ADVISORIES...
VA...NONE.
NC...NONE.
WV...NONE.
&&
$$
SYNOPSIS...AMS
NEAR TERM...AMS
SHORT TERM...PC
LONG TERM...SK
AVIATION...AMS/WERT
HYDROLOGY...PC
AREA FORECAST DISCUSSION
NWS SPOKANE WA
953 AM PST Sat Dec 24 2011
.SYNOPSIS...A weak storm system Saturday will bring the potential
for light wintry precipitation to the region. Stronger and wetter
storms will begin to impact the region Sunday and continue through
next week. The storm on Monday night and Tuesday will bring snow
to the lower elevations. The remainder of the week should see
mountain snow and valley rain with occasionally windy conditions.
&&
.DISCUSSION...
Update for today: Radar imagery across the area is fairly
impressive with 25-30 dBz echoes extending from near Odessa to
almost Cheney this morning as well as a more stratiform band of
precipitation sinking southward from the Canadian border with
widespread light snow from Sandpoint to Republic and all points
northward. The first set of activity is expected to wane through
the day, while the second precipitation band is likely to meander
through the northern zones of the forecast area for most of the
day. The result will be periods of flurries and snow pellets from
Lincoln County toward Kootenai County through the early afternoon,
while the northern zones see accumulating snowfall.
The models continue to struggle with precipitation across the
heart of the CWA. Previous versions of the NAM and HRRR indicated
widespread threats of light freezing rain and drizzle from Moses
Lake across the Waterville Plateau and toward the Spokane area.
Early indications are that this was overdone, with no locations
reporting any freezing precipitation as of this time and only snow
pellets really being noticed around Spokane. The 12z KOTX sounding
did show a very limited and weak warm layer aloft, however the wet
bulb profile on the sounding was well below freezing.
Additionally, time height sections from the NAM across the valleys
from the east slopes all the way to Spokane do indicate the best
lift generally in the -5 to -10C layer, which generally should not
be supportive of snowfall. However, with a dry layer below the
lifted layer, these time height sections would also fail to be
indicative of freezing drizzle. Given the convective elements on
radar and that the main overcast deck is still relatively high, it
seems that rimed snow pellets or even a few sleet pellets may be
the preferred precipitation mode for the activity that is moving
from Lincoln into Spokane County this morning. This activity
should lift northeast and likely dissipate as the mid levels
continue to dry through the day.
Farther north, model 295-305K layer isentropic ascent continues
through the day with decent, albeit decreasing, saturation of the
lifted layer by late in the day. A dichotomy of QPF values exists
with the NAM being significantly heavier than the GFS. Inspection
of radar trends favors the values of the NAM and the SREF was used
to smooth out the heavier bullseyes of the NAM across the northern
zones. The result was generally an inch or two of snowfall in many
spots across the northern half of Stevens and Pend Oreille
Counties as well as most of Bonner and Boundary Counties in Idaho.
/Fries
&&
.AVIATION...
18z TAFs: Any area of snow pellets is likely to affect KGEG
through KCOE this morning into early afternoon with CIGs falling a
bit as it translates through the area. Otherwise, CIGs by late
afternoon should be improving at most locations with a period of
VFR conditions likely by evening. Depending on clearing, fog may
redevelop overnight into Sunday morning, with the most likely
locations being KGEG, KSFF, and KCOE. This would result in
deteriorated conditions through the morning hours. Confidence is
not high in the development of fog overnight. /Fries
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 32 26 34 26 34 29 / 10 10 30 20 10 80
Coeur d`Alene 33 27 35 26 37 29 / 20 10 40 40 10 80
Pullman 37 30 39 29 38 32 / 10 0 20 40 10 70
Lewiston 40 32 44 30 43 36 / 0 0 10 20 10 30
Colville 29 25 34 21 34 28 / 60 10 40 30 20 90
Sandpoint 32 25 35 25 34 29 / 70 10 40 40 20 80
Kellogg 34 30 36 27 34 28 / 30 10 40 60 30 80
Moses Lake 32 24 35 23 35 27 / 10 0 20 10 10 40
Wenatchee 31 27 37 25 32 27 / 10 10 20 10 10 50
Omak 30 25 33 21 32 25 / 20 10 30 10 10 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS SPOKANE WA
500 AM PST Sat Dec 24 2011
.SYNOPSIS...A weak storm system Saturday will bring the potential
for light wintry precipitation to the region...mainly north of
Interstate 90. Stronger and wetter storms will begin to impact the
region Sunday and continue through next week. The storm on Monday
night and Tuesday will bring snow to the lower elevations. The
remainder of the week should see mountain snow and valley rain
with occasionally windy conditions.
&&
.DISCUSSION...
Update to today: Radar showing a broad area of light snow over the
Panhandle this morning. This is confirmed by airport observations at
Sandpoint and Bonners Ferry as well as web cameras. Updated
forecast to show light snow this morning in this area as well as
northeast Washington.
Meanwhile, temperatures continue to warm in the Cascade mountains.
Observations at Stevens Pass as well as surrounding mountains show
above freezing air moving in from the Pacific. Valley temperatures
in the Methow, Entiat, and Wenatchee valleys are currently in the
teens and will take a long time to warm. So the idea of light
freezing rain in these valleys still looks valid.
New 10Z HRRR model continues to show an area of freezing rain
developing over the western basin (i.e. Moses Lake and Ephrata) by
8am this morning and then moving northeastward to Spokane area
before noon. No evidence of this yet on satellite or radar so will
continue to monitor and will update/refine forecast if needed. RJ
...Areas of light freezing rain and snow possible today mainly
north of Interstate 90...
Today through Sunday night: The main focus over the holiday
weekend will be on potential for light freezing rain and snow
today, then potential for mountain snow showers Sunday with a mix
of rain and snow possible in the valleys. Overall, neither storm
system is very strong but may cause localized travel problems
related to icy or snow covered roadways.
For today`s storm system, satellite imagery this evening indicates
a stubborn flat ridge continuing to dominate the Inland NW with a
narrow fetch of subtropical moisture riding up the western spine
of the ridge and spilling into the Pac NW. Meanwhile, a potent
shortwave pivoting within the base of the mean Gulf of Alaska low
is deepening a midlevel low well off the coast. An elongated warm
front extended from this low will lift through the region today
and tonight bringing increasing warm advection ascending air
within the 285-290K isentropic surfaces. This will lead to an
increasing threat for light wintry precipitation with very little
in the way of accumulation. Needless to say, there is a great deal
of midlevel warming already taken place and as this wedge of
warmer air slides across the Cascades this morning, we will be
dealt a mix of wintry precipitation, with the most dominate types
likely to be snow or freezing rain, perhaps ice pellets. Model
initialization appears plausible compared to the 00Z satellite
imagery regarding the moisture plume and PV fields with the main
differences noted on the degree of boundary layer dryness overdone
by the 00Z GFS per surface obs and sfc-800mb raob comparison from
each KOTX and KUIL. Consequently, the forecast has included some
weight from the previously ignored NAM/SREF. Anyone who has been
following these models know that the QPF has been well overdone
the last few days, but has since backed off with the 00/06Z runs
and with a blend of the ECMWF/GFS, gives most locations along and
north of highway 2 some very light precipitation. The challenge
then becomes, what will the p-type be.
Observations from the Cascades already confirm that temperatures
at elevations roughly 3500-4000 feet and higher south of Lake
Chelan are warming near to slightly above freezing. The valleys
and deep basin remain in the teens to twenties and will likely
struggle to reach the freezing mark throughout the day with light
easterly flow and very little pcpn expected. This will keep the
dominate p-type snow or freezing rain with liquid equivalent
amounts generally near 0.02" or less. The SREF/NAM suggest the
highest probability for a few hours of light freezing rain will be
from along the highway 2 corridor from Spokane to Wenatchee and
valleys tucked within the East Slopes of the Cascades, including
the Methow Valley, Lake Chelan, and Wenatchee River Valley. Snow
will be dominate p-type from Omak to Bonners Ferry with little to
no accumulations expected. As the day wears on, the weak forcing
responsible light pcpn and warmer air will continue to nudge
northward eventually ending this evening as the midlevel warm
front lifts through. The only caveat is that very dry midlevel air
associated with the warm front suggest any threat for measurable
pcpn will end, but due to a lack of deep mixing to the surface,
residual boundary layer moisture will continue to lift into the
northern mountains with the potential for areas of drizzle or
freezing drizzle into the night.
Overall, much of the region will dry out Christmas Eve with the
next shortwave and associated cold front expected to race through
the region during the day Sunday. This will renew our chance for
rain and snow showers with most snow focusing over the Cascades,
northeastern Mtns of WA, and northern Idaho Panhandle. Strong
westerly flow in the 800-700mb layer will bring a great deal of
shadowing across the Basin but also aid the orographic pcpn
machine for the Cascades and Idaho Panhandle. A combination of
steepening lapse rates, differential PVA, orographics, and
potential for narrow CAPE within the -10 to -20C layer, suggest
isolated heavy snow showers will be possible over the higher
terrain from the Northern Cascades, east toward the Northern Idaho
Panhandle and travel across the Cascade, Northern Mtn, and Idaho
Panhandle mountain passes may be challenging at times if such
convective snow showers are able to materialize. SB
...Major weather pattern shift for next week...
Monday through Saturday: The predominant weather pattern of the
last month appears to finally be changing. Long range models in
good agreement on replacing the strong high pressure ridge over
the west coast with a strong zonal jet (about 160 kts) across the
Pacific. While not exactly typical of La Nina, the pattern is more
what we`re used to seeing in the winter. This pattern will yield
heavy precipitation for the Cascades and Panhandle mountains, with
mostly rain and wind for the lower elevations. Models typically
are too slow with the timing of weather systems with this pattern,
so forecast timing is likely to change a bit.
The first system of this pattern is currently out in the central
Pacific. MIMIC data show a subtropical moisture plume originating
near the Philippines that is already nearing the dateline. This
wave will reach the west coast on Monday, spreading precipitation
over the Inland Northwest Monday night and Tuesday. Atmosphere
ahead of this system will be cold and dry so dominant precip type
will be snow except for the Lewiston area. With the strong zonal
flow this system will move through the area quickly. The
prefrontal westerly flow will prevent much if any precipitation
for the Wenatchee/Moses Lake area. East of there decent snow
accumulations (2-4") are possible by Tuesday morning.
The next Pacific system will be quickly on the heels of the first,
arriving Tuesday night. There is a brief period of decent 700mb
warm air advection that will overcome the downslope off the
Cascades. Even so precip amounts for the basin will be light. Snow
levels will also rise with this system so most low land locations
will see rain instead of snow.
The rest of the week will finish out with 2 to 3 more Pacific
storms similar to their predecessors. Mild and occasionally windy
in the low lands with snow for the mountains. There could be
enough of a break Thursday night to allow the low lands to cool
enough to start as snow on Friday. But even if this happens the
precip will quickly change back to rain. RJ
&&
.AVIATION...
12Z TAFs: A weak Pacific storm will move onshore today bringing
light precipitation, mainly north of I-90. Precipitation will
start in the Cascades and western Basin this morning. Freezing
rain is possible in this area. The threat of light freezing rain
will move to the Spokane area in the afternoon. Any freezing rain
that occurs will be very light. Due to the low probability for
FZRA I left it out of the TAFs for now. MVFR conditions are likely
with this area of precipitation, and IFR is possible, mainly north
of KGEG in the afternoon. RJ
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 32 26 34 26 34 29 / 30 10 30 20 10 80
Coeur d`Alene 33 27 35 26 37 29 / 30 10 40 40 10 80
Pullman 37 30 39 29 38 32 / 20 0 20 40 10 70
Lewiston 40 32 44 30 43 36 / 10 0 10 20 10 30
Colville 29 25 34 21 34 28 / 50 10 40 30 20 90
Sandpoint 32 25 35 25 34 29 / 40 10 40 40 20 80
Kellogg 34 30 36 27 34 28 / 10 10 40 60 30 80
Moses Lake 32 24 35 23 35 27 / 20 0 20 10 10 40
Wenatchee 31 27 37 25 32 27 / 20 10 20 10 10 50
Omak 30 25 33 21 32 25 / 30 10 30 10 10 50
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
247 PM CST SAT DEC 24 2011
.SHORT TERM...TONIGHT THROUGH TUESDAY
247 PM CST SAT DEC 24 2011
TWAS THE NIGHT BEFORE CHRISTMAS WHEN ALL THROUGH THE UPPER
MISSISSIPPI RIVER VALLEY...A TROUGH WAS STIRRING THAT WILL BRING
CLOUDS TO COVER THE GALLEY.
SPLIT UPPER LEVEL FLOW WILL KEEP THE REGION DRY THROUGH THE
HOLIDAY WEEKEND INTO EARLY NEXT WEEK WITH ABOVE NORMAL
TEMPERATURES ON TAP.
SUNNY SKIES AND LOW LEVEL WARM AIR ADVECTION BROUGHT TEMPERATURES
INTO THE LOW 40S ACROSS MUCH OF THE REGION AND IN TURN MELTED AWAY
THE LITTLE SNOW THAT WAS LEFT FROM THIS PAST WEEK. A MID LEVEL
TROUGH CURRENTLY IN THE CANADIAN ROCKIES WILL DIVE DOWN THROUGH
THE NORTHWESTERLY FLOW TOWARD THE NORTHERN GREAT LAKES TONIGHT.
THE SOUTHERN EXTENT OF THIS TROUGH WILL PROVIDE A QUICK SHOT OF
MID LEVEL QG FORCING TO THE REGION...BUT DOES NOT APPEAR TO BE
DEEP ENOUGH...BASED ON 24.12Z NAM/GFS AND 24.18Z RUC
SOUNDINGS...TO OVERCOME THE SURFACE TO 700MB DRY LAYER TO PRODUCE
ANY PRECIPITATION. THE 24.18Z RUC SHOWS 600-400MB RH TO BE ON THE
INCREASE TOWARD ROCHESTER THIS EVENING WITH THESE HIGH CLOUDS
LINGERING THROUGH OUT THE REGION OVERNIGHT. WITH CONTINUED LOW
LEVEL WARM AIR ADVECTION GOING AND THE HIGH LEVEL CLOUD COVER
TONIGHT...LOW TEMPERATURES WILL NOT DROP OFF MUCH BELOW FREEZING.
AS THIS FEATURE PASSES THROUGH...A LOW LEVEL COLD FRONT WILL MOVE
THROUGH TOWARD DAYBREAK CHRISTMAS MORNING WITH 850MB TEMPERATURES
DROPPING FROM AROUND 1C DOWN TO -3C. THUS...HIGHS FOR CHRISTMAS
WILL BE A LITTLE LOWER THAN WHAT THEY WERE TODAY BUT STILL WELL
ABOVE NORMAL. OVERALL...IT WILL BE AN IDEAL TRAVEL DAY FOR THE
HOLIDAY WITH SUNNY SKIES AND NORTHWEST WINDS AROUND 10KTS.
A RIDGE AXIS WILL THEN MOVE THROUGH THE REGION ON SUNDAY NIGHT
WITH WARMER LOW LEVEL AIR ADVECTING BACK IN ON MONDAY ON THE BACK
SIDE OF THE RIDGE. THIS WILL LIKELY BE THE WARMEST DAY OVER THE
NEXT 7 DAYS WITH HIGHS JUMPING BACK INTO THE LOW 40S WITH NO SNOW
COVER LEFT TO RESTRICT THESE TEMPERATURES. WINDS WILL BE FAIRLY
GUSTY AHEAD OF A COLD FRONT WITH A TIGHTENING PRESSURE GRADIENT
SETTING UP. SUSTAINED WINDS OF AROUND 20KTS LOOK
POSSIBLE...PARTICULARLY AT ROCHESTER...WITH 24.12Z NAM AND GFS
SUGGESTING THAT MOMENTUM TRANSFER WILL BRING SOME 30KT GUSTS DOWN
TO THE SURFACE.
GOING INTO MONDAY NIGHT...THE 24.12Z NAM IS AN OUTLIER WITH ITS
SOLUTION OF BRINGING SOME PRECIPITATION CLOSE TO THE REGION INTO
NORTHERN ILLINOIS AND SOUTHERN WISCONSIN. IT BRINGS THE CUT OFF
LOW IN SOUTHERN NEW MEXICO UP TOWARD THE GREAT LAKES WHILE THE
OTHER MODELS SHOW THE LOW STAYING OFF TO THE SOUTH. THE PREFERRED
SOLUTIONS FROM HPC ON THIS FEATURE ARE WITH THE 24.12Z
UKMET/ECMWF/GEM WHICH ALL KEEP THE LOW WELL TO THE SOUTH AND DRY
HERE.
.LONG TERM...TUESDAY NIGHT THROUGH SATURDAY
247 PM CST SAT DEC 24 2011
CONFIDENCE DROPS OFF QUITE A BIT GOING INTO THE EXTENDED PERIOD
WITH AN ACTIVE NORTHWESTERLY FLOW SETTING UP ALOFT. THE 24.12Z GEM
IS THE FIRST TO INTRODUCE SOME PRECIPITATION ON WEDNESDAY WITH A
TROUGH AND SURFACE LOW COMING THROUGH DURING THE DAY. THIS
SOLUTION WOULD BRING A LIGHT ACCUMULATING SNOW ON WEDNESDAY...BUT
THE 24.12Z GFS AND ECMWF ARE SLOWER AND DEEPER WITH THIS TROUGH
AND BRING IT IN WEDNESDAY NIGHT INTO THURSDAY. HAVE GONE WITH THE
GFS/ECMWF TIMING AT THIS POINT. AFTER A BRIEF BREAK AS A RIDGE
AXIS COMES THROUGH...ANOTHER TROUGH WILL DROP DOWN INTO THE REGION
WITH A SURFACE LOW FORMING OVER THE DAKOTAS AND TRACKING EAST. THE
24.12Z ECMWF IS FURTHER NORTH WITH THIS TRACK WHILE THE 24.12Z GFS
IS MUCH MORE AMPLIFIED AND DROPS IT FURTHER SOUTH. HAVE KEPT SOME
SMALL CHANCES FOR PRECIPITATION IN THERE GOING INTO NEXT WEEKEND.
TEMPERATURE WISE IT LOOKS FAIRLY SEASONAL WITH NO BIG WARM UPS OR
COLD SPELLS DESPITE BEING IN THE NORTHWESTERLY FLOW.
&&
.AVIATION...THROUGH 18Z SUNDAY
1138 AM CST SAT DEC 24 2011
A TROUGH OF LOW PRESSURE WILL MOVE RAPIDLY SOUTHWEST THROUGH THE
FORECAST AREA TONIGHT. THIS SYSTEM WILL PRODUCE MID AND HIGH
CLOUDS ACROSS THE AREA TONIGHT. AN 8-12K DECK OF CLOUDS WILL MOVE
INTO KRST AROUND 25.02Z AND KLSE AROUND 25.03Z. THESE CLOUDS WILL
THEN MOVE OUT OF THE AREA BETWEEN 25.10Z AND 25.13Z. THE WINDS
WILL SHIFT FROM SOUTHWEST TO WEST AT 25.10Z AT KRST AND 25.11Z AT
KLSE...AND THEN SHIFT TO NORTHWEST AROUND 25.15Z. SUSTAINED WINDS
WILL BE IN THE 15 TO 20 KNOT RANGE TONIGHT AND CHRISTMAS MORNING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
247 PM CST SAT DEC 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...BOYNE
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
1107 AM CST SAT DEC 24 2011
.AVIATION/18Z TAFS/...VFR SKC INTO THIS EVENING. MID/HIGH CLOUDS
STREAMING SE FROM THE DAKOTAS WITH UPPER JET CORE AND 18 UNIT
VORTICITY MAXIMUM. BUFKIT SOUNDINGS AND MOS SHOW MID LEVEL
MOISTURE INCREASING TONIGHT INTO EARLY SUNDAY MORNING THOUGH LOW
LEVELS REMAIN PARCHED. GUSTY NW WINDS WITH STRONG SUBSIDENCE BY
SUN AFTERNOON AS SHORTWAVE SHIFTS TO THE EAST.
PC
&&
.PREV DISCUSSION... /ISSUED 338 AM CST SAT DEC 24 2011/
TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
CLOUDS ASSOCIATED WITH THE VORT MAX CROSSING THE GREAT LAKES REGION
ARE EXITING THE EASTERN FCST AREA EARLY THIS MORNING. WARM AIR
ADVECTION UNDERWAY...AS YESTERDAY/S MAX TEMPS WERE REACHED AT
MIDNIGHT. NEXT SHORTWAVE/VORT MAX APPARENT ON WATER VAPOR IMAGERY
OVER THE DAKOTAS AT 0330Z. NO CLOUDS ASSOCIATED WITH THIS
DISTURBANCE PER IR SATELLITE...SO FEEL COMFORTABLE WITH NO CHANCES
FOR FLURRIES OR EVEN CLOUDS THIS AFTERNOON AS THE WAVE PASSES
THROUGH.
MODEL SNDGS SHOW POTENTIAL FOR MIXING UP TO 950 OR EVEN 925MB THIS
AFTERNOON...SO LOWERED DEWPOINT TEMPS ACCORDINGLY. RUC AND GFS SHOW
WINDS UP TO AROUND 20 KT MIXING DOWN TO THE SFC AS WELL...WITH THE
NAM A BIT LIGHTER. BUMPED UP WIND GUSTS TO THE 18-20 KNOT RANGE THIS
AFTERNOON.
PRESSURE GRADIENT WILL CONTINUE TO INCREASE TONIGHT AS A LOW
PRESSURE SYSTEM TRACKS INTO ONTARIO CANADA. DESPITE SFC
INVERSION...WINDS SHOULD BE ELEVATED THROUGH THE NIGHT. TEMPS NOT
EXPECTED TO DROP MUCH SINCE THERE IS NO SNOW COVER AND CONTINUOUS
WARM AIR ADVECTION AND SOME SHALLOW MIXING. THE EXCEPTION MAY BE
LONE ROCK IF THEY DECOUPLE IN THE RIVER VALLEY.
CHRISTMAS DAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
MODELS DROP A DECENT SHORTWAVE THROUGH SOUTHERN WISCONSIN CHRISTMAS
MORNING. STILL KEEPING AN EYE ON THIS SYSTEM...AS THERE IS SOME
FORCING...BUT MODELS ACTUALLY TRENDING DRIER OVER THE LAST 24 HOURS.
CONCERN HAS BEEN THAT THIS MAY END UP LIKE A COUPLE OF THE PREVIOUS
WAVES THAT MOVED THROUGH...WHERE MODELS ARE DRY FOR DAYS LEADING UP
TO THE ARRIVAL OF THE SYSTEM...THEN SATURATE THINGS LATE IN THE
GAME. SEEMING LIKE THIS ONE WILL ACTUALLY STAY DRY AS ADVERTISED
THOUGH WITH NO SIGNS OF MODELS TRENDING WETTER.
STILL EXPECTING BREEZY WEST TO NORTHWEST WINDS CHRISTMAS AFTERNOON.
COLD ADVECTION ENSUES BEHIND THE WAVE...WITH THE WINDS PICKING UP
LATE MORNING INTO THE AFTERNOON. COULD SEE GUSTS OF 30-35 MPH IF
THINGS STAY ON TRACK. HIGHS EXPECTED TO BE IN THE MID TO UPPER 30S
AGAIN...THE COLDER TEMPS IN THE NORTH WHERE THE THIN SNOWPACK WILL
PROBABLY STILL LINGER.
MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM
WINDS QUICKLY RETURN TO OUT OF THE SOUTHWEST FOR MONDAY...BECOMING
BREEZY AGAIN LATE MORNING INTO THE AFTERNOON...THOUGH MAYBE A BIT
LIGHTER THAN ON CHRISTMAS. WITH THESE WINDS...A DECENT AMOUNT OF
SUN...AND WARMING ALOFT...SHOULD HIT 40 PRETTY EASILY...ESPECIALLY
IN LOCATIONS WITH NO SNOW COVER.
KEPT SOME LOW POPS IN THE FORECAST MONDAY NIGHT...AS MODELS BRING
ANOTHER SHORTWAVE THROUGH THE AREA. THE WILL WAVE DRAW UP A
DEEPENING SFC LOW...BUT THAT IS EXPECTED TO PASS BY WELL TO THE
SOUTHEAST. MAIN THREAT FOR PRECIP ASSOCIATED WITH A BAND OF MID
LEVEL FRONTOGENESIS AND THETA-E ADVECTION IN THE EVENING...AND SOME
ISENTROPIC LIFT WITH THE NORTHWEST FRINGE OF THE DEFORMATION PRECIP
AS THE LOW SLIDES BY LATER IN THE NIGHT. DEEP MOISTURE DEFINITELY AN
ISSUE...SO JUST KEPT POPS ON THE LIGHT SIDE. NEWEST ECMWF SUGGESTING
PRECIP WILL GENERALLY MISS SOUTHERN WISCONSIN COMPLETELY TO THE
SOUTH AND EAST.
WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...LOW TO MEDIUM
MODELS SHOWING THE WAVE TRAIN WILL CONTINUE THROUGH THE LATTER HALF
OF THE WORK WEEK. ENOUGH OVERLAP OF DECENT MOISTURE/LIFT IN MODELS
FOR SLIGHT CHANCE POPS THURSDAY AND FRIDAY. THE GFS AND ECMWF
DIVERGE BY FRIDAY THOUGH...WITH THE ECMWF MAINTAINING A STRONG SFC
LOW MOVING ACROSS NORTHERN MINNESOTA...WHILE THE GFS SLIDES THE LOW
SOUTHEAST TOWARD WISCONSIN. MAIN DIFFERENCE IS THAT THE ECMWF IS
MUCH WARMER...SUGGESTING MID 40S TO NEAR 50 FRIDAY...WHILE THE GFS
WOULD BE MAINLY 30S. GFS ALSO BRINGS A BIT MORE PRECIP...WITH BETTER
MOISTURE AND DYNAMICS TOWARD THE CENTER OF THE SYSTEM PUSHING INTO
THE FORECAST AREA. OVERALL...GENERALLY SPLIT THE DIFFERENCE BETWEEN
THE GFS AND ECMWF FOR NOW...WITH NO GOOD REASON TO GO ONE WAY OR THE
OTHER. EITHER WAY...LOOKS LIKE ABOVE NORMAL TEMPERATURES WILL
PROBABLY CONTINUE.
AVIATION/12Z TAFS/...WIND GUST POTENTIAL IN THE 20 KNOT RANGE THIS
AFTERNOON WITH SOME DAYTIME MIXING. VFR THROUGH THE PERIOD. CLEAR
SKIES EXPECTED TODAY...THEN INCREASING HIGH/MID CLOUDS TONIGHT.
WINDS WILL ALSO INCREASE OVER THE PERIOD AND BECOME GUSTY ONCE AGAIN
ON SUNDAY WITH A PASSING UPPER LEVEL DISTURBANCE.
MARINE...THERE IS A POSSIBILITY OF SOME WIND GUSTS UP TO 22 KNOTS
THIS AFTERNOON WITH DAYTIME MIXING...BUT CONFIDENCE IS LOW...SO NO
SMALL CRAFT ADVY ISSUED FOR THIS TIME PERIOD. HOWEVER...A LOW
PRESSURE SYSTEM CROSSING SOUTHERN CANADA THROUGH SUNDAY WILL BRING
INCREASING WINDS TO SOUTHERN LAKE MICHIGAN. SOUTHWESTERLY WIND GUSTS
EXPECTED TO REACH SMALL CRAFT ADVY CRITERIA OVERNIGHT SATURDAY NIGHT
THROUGH SUNDAY AFTERNOON. SMALL CRAFT ADVY ISSUED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST SUNDAY
FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MRC
SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
338 AM CST SAT DEC 24 2011
.TODAY AND TONIGHT...FORECAST CONFIDENCE...HIGH
CLOUDS ASSOCIATED WITH THE VORT MAX CROSSING THE GREAT LAKES REGION
ARE EXITING THE EASTERN FCST AREA EARLY THIS MORNING. WARM AIR
ADVECTION UNDERWAY...AS YESTERDAY/S MAX TEMPS WERE REACHED AT
MIDNIGHT. NEXT SHORTWAVE/VORT MAX APPARENT ON WATER VAPOR IMAGERY
OVER THE DAKOTAS AT 0330Z. NO CLOUDS ASSOCIATED WITH THIS
DISTURBANCE PER IR SATELLITE...SO FEEL COMFORTABLE WITH NO CHANCES
FOR FLURRIES OR EVEN CLOUDS THIS AFTERNOON AS THE WAVE PASSES
THROUGH.
MODEL SNDGS SHOW POTENTIAL FOR MIXING UP TO 950 OR EVEN 925MB THIS
AFTERNOON...SO LOWERED DEWPOINT TEMPS ACCORDINGLY. RUC AND GFS SHOW
WINDS UP TO AROUND 20 KT MIXING DOWN TO THE SFC AS WELL...WITH THE
NAM A BIT LIGHTER. BUMPED UP WIND GUSTS TO THE 18-20 KNOT RANGE THIS
AFTERNOON.
PRESSURE GRADIENT WILL CONTINUE TO INCREASE TONIGHT AS A LOW
PRESSURE SYSTEM TRACKS INTO ONTARIO CANADA. DESPITE SFC
INVERSION...WINDS SHOULD BE ELEVATED THROUGH THE NIGHT. TEMPS NOT
EXPECTED TO DROP MUCH SINCE THERE IS NO SNOW COVER AND CONTINUOUS
WARM AIR ADVECTION AND SOME SHALLOW MIXING. THE EXCEPTION MAY BE
LONE ROCK IF THEY DECOUPLE IN THE RIVER VALLEY.
.CHRISTMAS DAY...FORECAST CONFIDENCE...MEDIUM TO HIGH
MODELS DROP A DECENT SHORTWAVE THROUGH SOUTHERN WISCONSIN CHRISTMAS
MORNING. STILL KEEPING AN EYE ON THIS SYSTEM...AS THERE IS SOME
FORCING...BUT MODELS ACTUALLY TRENDING DRIER OVER THE LAST 24 HOURS.
CONCERN HAS BEEN THAT THIS MAY END UP LIKE A COUPLE OF THE PREVIOUS
WAVES THAT MOVED THROUGH...WHERE MODELS ARE DRY FOR DAYS LEADING UP
TO THE ARRIVAL OF THE SYSTEM...THEN SATURATE THINGS LATE IN THE
GAME. SEEMING LIKE THIS ONE WILL ACTUALLY STAY DRY AS ADVERTISED
THOUGH WITH NO SIGNS OF MODELS TRENDING WETTER.
STILL EXPECTING BREEZY WEST TO NORTHWEST WINDS CHRISTMAS AFTERNOON.
COLD ADVECTION ENSUES BEHIND THE WAVE...WITH THE WINDS PICKING UP
LATE MORNING INTO THE AFTERNOON. COULD SEE GUSTS OF 30-35 MPH IF
THINGS STAY ON TRACK. HIGHS EXPECTED TO BE IN THE MID TO UPPER 30S
AGAIN...THE COLDER TEMPS IN THE NORTH WHERE THE THIN SNOWPACK WILL
PROBABLY STILL LINGER.
.MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM
WINDS QUICKLY RETURN TO OUT OF THE SOUTHWEST FOR MONDAY...BECOMING
BREEZY AGAIN LATE MORNING INTO THE AFTERNOON...THOUGH MAYBE A BIT
LIGHTER THAN ON CHRISTMAS. WITH THESE WINDS...A DECENT AMOUNT OF
SUN...AND WARMING ALOFT...SHOULD HIT 40 PRETTY EASILY...ESPECIALLY
IN LOCATIONS WITH NO SNOW COVER.
KEPT SOME LOW POPS IN THE FORECAST MONDAY NIGHT...AS MODELS BRING
ANOTHER SHORTWAVE THROUGH THE AREA. THE WILL WAVE DRAW UP A
DEEPENING SFC LOW...BUT THAT IS EXPECTED TO PASS BY WELL TO THE
SOUTHEAST. MAIN THREAT FOR PRECIP ASSOCIATED WITH A BAND OF MID
LEVEL FRONTOGENESIS AND THETA-E ADVECTION IN THE EVENING...AND SOME
ISENTROPIC LIFT WITH THE NORTHWEST FRINGE OF THE DEFORMATION PRECIP
AS THE LOW SLIDES BY LATER IN THE NIGHT. DEEP MOISTURE DEFINITELY AN
ISSUE...SO JUST KEPT POPS ON THE LIGHT SIDE. NEWEST ECMWF SUGGESTING
PRECIP WILL GENERALLY MISS SOUTHERN WISCONSIN COMPLETELY TO THE
SOUTH AND EAST.
WEDNESDAY THROUGH FRIDAY...FORECAST CONFIDENCE...LOW TO MEDIUM
MODELS SHOWING THE WAVE TRAIN WILL CONTINUE THROUGH THE LATTER HALF
OF THE WORK WEEK. ENOUGH OVERLAP OF DECENT MOISTURE/LIFT IN MODELS
FOR SLIGHT CHANCE POPS THURSDAY AND FRIDAY. THE GFS AND ECMWF
DIVERGE BY FRIDAY THOUGH...WITH THE ECMWF MAINTAINING A STRONG SFC
LOW MOVING ACROSS NORTHERN MINNESOTA...WHILE THE GFS SLIDES THE LOW
SOUTHEAST TOWARD WISCONSIN. MAIN DIFFERENCE IS THAT THE ECMWF IS
MUCH WARMER...SUGGESTING MID 40S TO NEAR 50 FRIDAY...WHILE THE GFS
WOULD BE MAINLY 30S. GFS ALSO BRINGS A BIT MORE PRECIP...WITH BETTER
MOISTURE AND DYNAMICS TOWARD THE CENTER OF THE SYSTEM PUSHING INTO
THE FORECAST AREA. OVERALL...GENERALLY SPLIT THE DIFFERENCE BETWEEN
THE GFS AND ECMWF FOR NOW...WITH NO GOOD REASON TO GO ONE WAY OR THE
OTHER. EITHER WAY...LOOKS LIKE ABOVE NORMAL TEMPERATURES WILL
PROBABLY CONTINUE.
&&
.AVIATION/12Z TAFS/...WIND GUST POTENTIAL IN THE 20 KNOT RANGE THIS
AFTERNOON WITH SOME DAYTIME MIXING. VFR THROUGH THE PERIOD. CLEAR
SKIES EXPECTED TODAY...THEN INCREASING HIGH/MID CLOUDS TONIGHT.
WINDS WILL ALSO INCREASE OVER THE PERIOD AND BECOME GUSTY ONCE AGAIN
ON SUNDAY WITH A PASSING UPPER LEVEL DISTURBANCE.
&&
.MARINE...THERE IS A POSSIBILITY OF SOME WIND GUSTS UP TO 22 KNOTS
THIS AFTERNOON WITH DAYTIME MIXING...BUT CONFIDENCE IS LOW...SO NO
SMALL CRAFT ADVY ISSUED FOR THIS TIME PERIOD. HOWEVER...A LOW
PRESSURE SYSTEM CROSSING SOUTHERN CANADA THROUGH SUNDAY WILL BRING
INCREASING WINDS TO SOUTHERN LAKE MICHIGAN. SOUTHWESTERLY WIND GUSTS
EXPECTED TO REACH SMALL CRAFT ADVY CRITERIA OVERNIGHT SATURDAY NIGHT
THROUGH SUNDAY AFTERNOON. SMALL CRAFT ADVY ISSUED.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY FROM 9 PM THIS EVENING TO 6 PM CST SUNDAY
FOR LMZ643>646.
&&
$$
TODAY/TONIGHT AND AVIATION/MARINE...MRC
SUNDAY THROUGH FRIDAY...DDV
AREA FORECAST DISCUSSION
NWS GOODLAND KS
234 AM MST MON DEC 26 2011
.SYNOPSIS...
LATEST IR SATELLITE IMAGERY AND RUC ANALYSIS SHOWED A SHORT WAVE
TROUGH MOVING ACROSS THE NORTHERN CONUS WITH AREAS OF CLOUDS AHEAD
OF IT. FURTHER SOUTH THE CLOSED LOW CONTINUES TO SPIN OVER EASTERN
NEW MEXICO AND WESTERN TEXAS. CURRENT RADAR SHOWS ECHOES OVER
SOUTHWEST KANSAS AS SOME MOISTURE MOVES UP FROM THE CLOSED LOW...WITH
A FEW SPRINKLES AND LIGHT SNOW REACHING THE GROUND. AT THE SURFACE
A HIGH PRESSURE WAS PROGRESSING OUT OF THE TRI-AREA AHEAD OF THE
PRE-FRONTAL TROUGH THAT WILL MOVE THROUGH TODAY.
JTL
&&
.SHORT TERM (TODAY-WEDNESDAY)...
227 AM MST MON DEC 26 2011
TEMPERATURES WILL BE THE MAIN FOCUS FOR THIS PERIOD.
TODAY A PRE-FRONTAL SURFACE TROUGH WILL MOVE THROUGH THE AREA DURING
THE DAY...CAUSING THE SOUTHWEST WINDS TO SHIFT TO THE NORTHWEST.
WITH LITTLE MOISTURE TO WORK WITH...AM ONLY ANTICIPATING STRONGER
WINDS AND A FEW CLOUDS BEHIND THE TROUGH. HIGH TEMPERATURES WILL BE
SIMILAR TO YESTERDAY.
TUESDAY THROUGH WEDNESDAY...ANOTHER SURFACE AND UPPER LEVEL TROUGH
WILL MOVE THROUGH THE TRI-STATE AREA DURING THE LATE AFTERNOON AND
EVENING HOURS. SOUNDINGS AND CROSS SECTIONS SHOW UPPER LEVEL
MOISTURE INCREASING AS THE TROUGH MOVES THROUGH. THERE ALSO IS SOME
INSTABILITY PRESENT...ALONG WITH LIFT FROM FRONTOGENESIS AND WARM
AIR ADVECTION AS THE TROUGH MOVES THROUGH. HOWEVER A NARROW LAYER
OF MUCH DRIER AIR BETWEEN THE SURFACE AND THE MOISTURE MAY HINDER
ANY PRECIPITATION FROM REACHING THE GROUND. CANNOT COMPLETELY RULE
OUT SOMETHING FROM REACHING THE GROUND SO WILL ADD A MENTION OF
FLURRIES FOR AREAS NORTH OF A BENKLEMEN TO HILL CITY LINE. TEMPERATURES
WILL BE COOLER TUESDAY AS SLIGHTLY COOLER AIR WILL MOVE IN BEHIND
MONDAY/S TROUGH. WEDNESDAY THE ENVIRONMENT DRIES OUT BEHIND THE
TROUGH. TEMPERATURES WILL BE WARMER AS 850MB TEMPERATURES
INCREASE.
JTL
.LONG TERM (THURSDAY-SUNDAY)...
227 AM MST MON DEC 26 2011
A SERIES OF WEAK SHORT WAVE TROUGHS WILL MOVE ACROSS
THE HIGH PLAINS THROUGH THE REST OF THE WEEK...BUT BEST LIFT AND
MOISTURE WILL BE FAR NORTH OF THE FORECAST AREA. MODELS INDICATE THE
BEST CHANCE FOR ANY PRECIPITATION WOULD BE TOWARD THE END OF THE
PERIOD...SATURDAY NIGHT/SUNDAY MORNING. MODELS DIFFER IN THEIR
SOLUTIONS AT THAT TIME. THE ECMWF IS FURTHER SOUTH AND WEST WITH
DYNAMICS AND MOISTURE THAN THE GFS. WITH ENSEMBLES SHOWING WIDE
VARIABILITY AFTER 120 HOURS...WILL STAY THE COURSE OF A DRY
FORECAST. TEMPERATURES WILL BE ABOVE NORMAL WITH DAILY MAXIMUM
TEMPERATURES MAINLY IN THE 50S.
SAM
&&
.AVIATION...
944 PM MST SUN DEC 25 2011
BOTH TERMINALS WILL EXPERIENCE VFR CONDS THE NEXT 24 HOURS. LIGHT
SOUTHWESTERLY WINDS WILL BEGIN TO SWITCH TO THE NORTHWEST DURING
THE AFTERNOON HOURS ON MONDAY AS A TROUGH MOVES ACROSS THE REGION. A
FEW HIGH CLOUDS ARE ALSO EXPECTED THROUGH THE AFTERNOON AND
EVENING HOURS.
BAS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
222 AM CST MON DEC 26 2011
.SYNOPSIS...
MID AND UPPER AIR ANALYSIS INDICATES A SHORTWAVE TROUGH PUSHING ACROSS
MONTANA. A 500 HPA LOW WAS SPINNING ACROSS THE WESTERN TEXAS PANHANDLE.
MOISTURE ADVECTION WAS EVIDENT ON THE KDDC RAOB AS THE MIDDLE ATMOSPHERE
MOISTENED UP CONSIDERABLY IN THE 12 HOUR GAP BETWEEN SYNOPTIC FLIGHTS.
KDDC WSR-88D WAS DETECTING SOME LIGHT ECHOES ACROSS SOUTH CENTRAL KANSAS.
A QUICK CALL MADE TO BARBER COUNTY INDICATES SOME SPRINKLES WERE OCCURRING
WITHIN THE COUNTY. -SUGDEN
&&
.DISCUSSION...
DAYS 1-2...
TODAY:
THE IMMEDIATE SHORT TERM CONCERN WAS TO TREND POPS AND WX TO RADAR TRENDS
ACROSS SOUTH CENTRAL KANSAS. THIS ACTIVITY WAS IN RESPONSE TO 600-700
HPA FRONTOGENESIS. HAVE FOLLOWED HRRR GUIDANCE ON THE DEPARTURE OF THIS
ACTIVITY THROUGH THE MORNING. FORECAST SOUNDINGS SHOW A DRY THERMODYNAMIC
PROFILE BELOW 850 HPA SO THINK MOST OF THIS ACTIVITY IS EVAPORATING
BEFORE REACHING THE SURFACE. HAVE KEPT 15 PERCENT POPS IN THE GRIDS
AND WILL QUICKLY TAPER TO ZERO TOWARDS 15Z THIS MORNING. OTHER CONCERN
IS A 5KFT STRATUS LAYER THAT HAS SPREAD ACROSS MUCH OF SOUTHWEST KANSAS.
THINK THIS WILL MOVE OFF TO THE EAST AND REDUCE IN AERIAL COVERAGE WITH
MIXING TOWARDS MID MORNING.
MEANWHILE, THE AFOREMENTIONED UPPER LEVEL SHORTWAVE TROUGH MENTIONED
IN THE SYNOPSIS WILL USHER IN A COLD FRONT TONIGHT. PRECIPITATION IS
NOT EXPECTED ALONG THE BOUNDARY AS THE ATMOSPHERE IS FAIRLY DRY AND
DRY AIR ADVECTION WILL CONTINUE IN THE WAKE OF THE SURFACE BOUNDARY.
THE MAIN IMPACTS FROM THE DENSITY GRADIENT WILL BE A SHIFT IN THE WINDS.
HIGHS TODAY WILL BE MAINLY IN THE 30S DEG F FOR MUCH OF THE COUNTY WARNING
AREA EXCEPT TOWARDS SOUTH CENTRAL KANSAS WHERE 40S DEG F ARE FORECAST.
A CONTINUATION OF THE EROSION OF THE SNOWPACK IS EXPECTED TODAY, PARTICULARLY
ACROSS THE EASTERN SECTIONS OF THE SNOWPACK.
TONIGHT:
POST FRONTAL 10 TO 15 KT NORTHWESTERLY TO NORTHERLY WINDS ARE EXPECTED
TONIGHT AND THROUGH THE OVERNIGHT HOURS. MINIMUMS SHOULD BE WARMER HEADING
INTO TUESDAY MORNING AS WINDS CONTINUE IN THE 5 TO 10 KT RANGE OVERNIGHT AND
PROVIDE SLIGHTLY MORE MIXING. TEENS TO UPPER 20 DEG F ARE EXPECTED ACROSS
THE REGION WITH THE COOLEST TEMPERATURES ACROSS MY NORTHWEST COUNTIES.
TUESDAY:
A SURFACE RIDGE OF HIGH PRESSURE WILL SLIDE ACROSS KANSAS TUESDAY.
SOUTHERLY WINDS ARE EXPECTED ON THE BACKSIDE OF THE HIGH BY TUESDAY
EVENING ACROSS WESTERN KANSAS. LOW 50S DEG F TEMPERATURES ARE POSSIBLE
TOWARDS P28 TOMORROW. OTHERWISE MOST OF THE REGION SHOULD BE IN THE
UPPER 30S DEG F (MAINLY ACROSS SNOWPACK) AND 40S DEG F ACROSS BARE GROUND.
THE SNOWPACK WILL CONTINUE TO ERODE THROUGH THE DAY ON TUESDAY.
TUESDAY NIGHT:
I HAVE INCREASED CLOUD COVER TUESDAY EVENING INTO WEDNESDAY MORNING
AS MID TO UPPER LEVEL SATURATION IS INDICATED BY FORECAST SOUNDINGS
AHEAD OF A SECONDARY APPROACHING SHORTWAVE TROUGH MOVING ACROSS THE
PLAINS. MODELS ARE NOT INDICATING ANY QPF WITH THIS SYSTEM SO STILL
HAVE POPS AT ZERO THROUGH THE EVENING. FORECAST SOUNDINGS ALSO SHOW
A DRY PROFILE BELOW 700 HPA WHICH SUPPORTS A DRY FORECAST. -SUGDEN
DAYS 3-7...
THE MEDIUM RANGE FORECAST CONTINUES TO LOOK WARM AND DRY IN A PROLONGED
DOWNSLOPE-FAVORED UPPER AIR PATTERN...WITH NO HAZARDOUS WINTER WEATHER
EXPECTED FOR MUCH OF THE WESTERN PLAINS. THAT BEING SAID...WILL BE WATCHING
FOR POSSIBLE STORM DEVELOPMENT EAST OF HERE AROUND THE 1ST OF JANUARY
AS THE LARGE SCALE CIRCULATION REGIME AMPLIFIES.
WEDNESDAY-FRIDAY:
WEST-NORTHWESTERLY DOWNSLOPE MOMENTUM WILL YIELD A WARMING LOWER TROPOSPHERE
AND DAILY TEMPERATURES WARMING INTO THE 50S. WHATEVER SNOWPACK REMAINS
BY WEDNESDAY WILL BE TAKING A SERIOUS HIT DURING THIS TIME FRAME WITH
ALMOST NO INFLUENCE AT ALL OF SNOWPACK ON TEMPERATURES BY THE END OF
THE WEEK AS MUCH OF IT SHOULD BE MELTED BY THEN (EXCEPT FOR THE COLORADO
BORDER AREAS). HIGHS IN THE MID 50S ARE LIKELY AND PERHAPS A FEW 60
DEGREE READINGS WILL OCCUR ACROSS SOUTH-CENTRAL KANSAS ZONES THURSDAY
AND FRIDAY.
SATURDAY-SUNDAY:
A LARGE RIDGE IS EXPECTED TO FORM ALONG THE WEST COAST/WESTERN CONUS
WHICH WILL FAVOR A DOWNSTREAM TROUGH DEVELOPMENT OVER THE CENTRAL/EASTERN
PLAINS. THE FORMATION OF THIS TROUGH IS SHOWN BY ALL THE GLOBAL MODELS
TO BE OVER OR EAST OF WESTERN KANSAS WHICH DOES NOT FAVOR WIDESPREAD
ACCUMULATING PRECIPITATION GIVEN UNFAVORABLE LOW LEVEL TRAJECTORIES
TO OUR SOUTH (MOISTURE ADVECTION). A MID LATITUDE CYCLONE OF SOME SEMBLANCE
WILL PROBABLY MATURE OVER THE MIDWEST /OHIO-VALLEY AS A RESULT OF THIS
TROUGH DEVELOPMENT WITH STRONG, DRY NORTHWEST WINDS ACROSS THE WESTERN
PLAINS ON THE ORDER OF LATE SATURDAY INTO SUNDAY. SINCE THIS IS STILL
IN THE DAY 6-7 TIME RANGE THERE IS STILL SOME UNCERTAINTY AS TO WHEN/WHERE
(OR EVEN IF) EXACTLY A STORM WILL FORM SO WILL HAVE TO WATCH SUBSEQUENT
MODEL SOLUTIONS TO SEE HOW THIS TROUGH DEVELOPS AND IF IT WILL HAVE
ANY SUBSTANTIAL SENSIBLE WEATHER IMPACTS ON SOUTHWEST KANSAS.
&&
.AVIATION...
FOR THE 06Z TAF ISSUANCE...AN UPPER LEVEL STORM SYSTEM OVER OKLAHOMA
AND WEST TEXAS WILL CONTINUE TO SPREAD MID-LEVEL MOISTURE ACROSS
WESTERN KANSAS TONIGHT. 6000-9000 FT CIGS WILL PERSIST THROUGH
12-15Z. VFR CONDITIONS WILL PREVAIL. WINDS WILL BE LIGHT TONIGHT
AND THEN SOUTHWESTERLY AT 5 TO 10 KTS AFTER 12Z MONDAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 36 21 42 23 / 0 0 0 0
GCK 33 17 37 19 / 0 0 0 0
EHA 35 21 43 25 / 0 0 0 0
LBL 36 19 45 22 / 0 0 0 0
HYS 37 23 41 25 / 0 0 0 0
P28 44 26 50 26 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN36/25/25
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
1158 PM CST SUN DEC 25 2011
.UPDATE...
UPDATED TO INCLUDE 06Z AVIATION DISCUSSION BELOW.
&&
.DISCUSSION...
OUR STRETCH OF QUIET AND PREDOMINANTLY MILD WEATHER LOOKS TO
CONTINUE THROUGH THE FORESEEABLE FUTURE... WITH ONLY A FEW MINOR
SYSTEMS WITH WHICH TO BE CONCERNED. THERE ARE AT LEAST SOME
INDICATIONS FOR A BIT OF ACTIVITY DURING THE LATTER HALF OF THE
WEEK AS A FEW SYSTEMS TRACK A BIT CLOSER TO US... ALTHOUGH
INDICATIONS ARE THAT THEIR IMPACT MAY PRIMARILY BE FELT TO OUR
NORTH. THE MAIN WEATHER ITEM OF CONCERN LOOKS TO BE SOME GUSTY
WINDS TONIGHT INTO MONDAY AS THE PRESSURE GRADIENT SIGNIFICANTLY
TIGHTENS OVER THE AREA WITH A 992MB SURFACE LOW TRACKING EAST
THROUGH SOUTHERN CANADA. THE GFS AND NAM BOTH SUGGEST WINDS AOA 65
KT IN THE BOTTOM FEW THOUSAND FEET LATE TONIGHT INTO EARLY MONDAY.
ALTHOUGH THESE WON/T BE REALIZED AT THE SURFACE... LOCATIONS IN
THE WEST CENTRAL AND SOUTHWEST PORTION OF THE CWFA SHOULD SEE SOME
GUSTS ABOVE 40KT DURING THAT TIME FRAME GIVEN MORE FAVORABLE
TOPOGRAPHIC CONDITIONS IN THAT AREA... NAMELY THEIR EXPOSURE AND
POTENTIAL FOR DOWNSLOPE ENHANCEMENT IN THE LEE OF THE BUFFALO
RIDGE. GIVEN THIS POTENTIAL... WILL BE ISSUING A WIND ADVISORY FOR
THE OVERNIGHT INTO THE MORNING HOURS FOR PART OF THE WEST CENTRAL
AND SOUTHWEST CWFA. THE REMAINDER OF THE AREA SHOULD SEE GUSTY
WINDS DEVELOP AS WELL... BUT AT THIS POINT THE EXPECTATION IS THAT
THEY WILL REMAIN BELOW ADVISORY LEVELS OVER THE REMAINDER OF THE AREA.
IN THE BIG PICTURE... WATER VAPOR IMAGERY AND RUC UPPER AIR
ANALYSES SHOW A DEPARTING SHORTWAVE MOVING THROUGH THE GREAT
LAKES... WITH THE NEXT FEATURE ASCENDING THE RIDGE OVER THE
WESTERN STATES AND SOUTHWEST CANADA. THIS SHORTWAVE WILL HELP
DRIVE THE AFOREMENTIONED SURFACE LOW ACROSS SOUTHERN CANADA ON
MONDAY... WITH GUSTY SOUTHWEST WINDS AND SIGNIFICANT WARM
ADVECTION ACROSS OUR AREA. HIGH TEMPERATURES WILL BE WELL ABOVE
NORMAL ONCE AGAIN... AND A FEW SPOTS COULD APPROACH RECORDS. GIVEN
SOME UNCERTAINTY ON THE DEGREE OF MID AND HIGH CLOUDS DID NOT GO
WITH EXCEEDINGLY HIGH VALUES... ALTHOUGH STILL ROUGHLY 20 DEGREES
ABOVE NORMAL... SO THE OVERNIGHT SHIFT AND SHORT TERM FORECASTS ON
MONDAY WILL LIKELY NEED TO MAKE SOME REFINEMENTS. THE COLD FRONT
WILL PUSH ACROSS THE AREA DURING THE AFTERNOON AND EVENING
HOURS... AND LOOKS TO COME THROUGH PCPN-FREE. COOLER... YET STILL
ABOVE NORMAL... TEMPERATURES LOOK TO RETURN FOR TUESDAY. INCLUDED
A FEW FLURRIES FOR TUESDAY NIGHT INTO WEDNESDAY AS A LOBE OF WARM
ADVECTION AHEAD OF THE NEXT SYSTEM SWINGS ACROSS THE AREA. THE
NAM... GFS... SREF... AND ECMWF ALL WRING OUT SOME LIGHT PCPN WITH
THIS FEATURE... AND THERE IS A NARROW AXIS OF REDUCED CONDENSATION
PRESSURE DEFICITS COINCIDENT WITH THE BETTER ISENTROPIC ASCENT...
SO MAY NEED TO EVENTUALLY INTRODUCE SOME POPS. THE BAROCLINIC ZONE
LOOKS TO LINGER OVER THE AREA AS ANOTHER WEAK SHORTWAVE SWINGS BY
WEDNESDAY NIGHT... SO KEPT LOW CHANCE POPS TO ACCOUNT FOR THAT.
A MORE SUBSTANTIAL FEATURE CONTINUES TO BE ADVERTISED BY THE GFS
AND ECMWF DURING THE THURSDAY NIGHT-FRIDAY TIME FRAME. BOTH
SUGGEST A DECENT NORTHWEST-SOUTHEAST ORIENTED AREA OF MID LEVEL
FRONTOGENESIS ON THE NORTH SIDE OF A 995MB-ISH SURFACE LOW WHICH
TRACKS FROM CENTRAL NORTH DAKOTA THROUGH THE TWIN CITIES AREA AND
EVENTUALLY TO CENTRAL LAKE MICHIGAN. THERE IS A FAIRLY PROLONGED
PERIOD OF WEST TO SOUTHWESTERLY FLOW IN PLACE BEFORE THIS SYSTEM
MOVES INTO THE AREA... SO WE SHOULD HAVE A BETTER CHANCE OF SEEING
DEEP SATURATION AND SOME HEALTHIER PCPN AMOUNTS... AND INDEED BOTH
THE GFS AND ECMWF MANAGE TO PRODUCE MAX AMOUNTS NEAR A QUARTER OF
AN INCH. THE BIG QUESTION WILL BE WHERE EXACTLY THE BAND OF
PCPN... WHICH SHOULD BE IN THE FORM OF SNOW... WILL SETUP. AT THE
CURRENT TIME IT LOOKS LIKE THE BEST CHANCE WOULD BE ALONG AND
NORTH OF THE I-94 CORRIDOR GIVEN THE FORECAST POSITION OF THE
UPPER JET AND TRACK OF THE SURFACE LOW TOGETHER WITH THE MID-LEVEL
TEMPERATURE GRADIENT. OF COURSE... MUCH CAN CHANGE WITH SOMETHING
THAT IS EXPECTED 4-5 DAYS FROM NOW... SO AT THIS POINT JUST
INCLUDED CHANCE POPS FOR MUCH OF THE AREA... WITH HIGHER VALUES
OVER THE NORTHERN FORECAST AREA. IT CERTAINLY DOESN/T LOOK TO BE A
BARN-BURNER... BUT AT THIS POINT ANY SORT OF ORGANIZED
ACCUMULATING PCPN IS ATTENTION GRABBING. A DECENT SHOT OF COLD AIR
LOOKS TO ARRIVE IN THE WAKE OF THIS FEATURE... PERHAPS PRODUCING
TEMPERATURES THAT ARE ONLY 5-10 DEGREES ABOVE NORMAL. OTHERWISE...
IT LOOKS TO BE MAINLY DRY AS WE HEAD THROUGH THE UPCOMING WEEKEND
ALTHOUGH THERE ARE HINTS OF ANOTHER WEAK SHOT OF PCPN SLIPPING
THROUGH LATE SATURDAY INTO SUNDAY.
&&
.AVIATION.../06Z TAF ISSUANCE/
MAIN CONCERN IS STILL WINDS/LLWS BUT THEN BECOMES TIMING OF MVFR
CIGS ARND 27/06Z. MODELS STILL SHOWING 50-60 KT WINDS IN THE
1500-2000 FT LAYER OVER ALL TERMINALS STARTING BETWEEN 06Z-12Z
THIS MORNING AND LASTING 6-10 HOURS AT EACH SITE. HAVE CONTINUED
ITS INCLUSION AT ALL SITES...STAGGERED FROM W TO E...MAINLY FOR
THE SPEED SHEAR BUT ALSO FOR SOME DIRECTIONAL SHEAR BY ABOUT 30-40
DEGREES GOING ALOFT. SFC WINDS WILL INCRS TO NEAR 20 KT WITH GUSTS
NEAR 30 KT...OCNLY NEAR 35 KT. WINDS ALOFT SETTLE DOWN BY EARLY TO
MID AFTN...THUS ELIMINATING THE LLWS CONCERN. AS FOR
CLOUDS...MAINLY HIGH CLOUDS WILL PREVAIL BUT GOING INTO TMRW
EVE...THERE ARE INDICATIONS OF A LOWER SWATH OF MOISTURE COMING
ACRS. SREF AND NAM INDICATE THAT MVFR CIGS HAVE A GROWING
POSSIBILITY BUT THE MAIN ISSUE IS TIMING...RIGHT NEAR THE 06Z
CUTOFF. HAVE TRENDED DOWN TO MVFR AT THE NWRN SITES - KAXN AND
KSTC - WHILE ADVERTISING SCT030 AT THE REMAINING SITES THROUGH
06Z.
MSP...VFR THROUGH MON AFTN WITH WINDS THE MAIN CONCERN...THEN PSBL
MVFR CIGS MON NIGHT INTO TUE MRNG. MODEL GUIDANCE STILL SHOWS
SOLID 50-60 KT WINDS UPWARDS OF 2 KFT STARTING NEAR DAYBREAK AND
LASTING THRU EARLY AFTN. EVEN WITH STRONG GUSTS AFTER THE MRNG
INVERSION...LLWS CONDITIONS WILL PERSIST THRU EARLY AFTN BEFORE
DIMINISHING LATE DAY. MAIN CONCERN BECOMES CROSSWIND CONCERNS FOR
THE PARALLELS WITH SW WINDS INCRG TO NEAR 20 KT WITH GUSTS IN THE
25-30 KT RANGE. FREQUENT ELEVATED GUSTS CONTINUE TO ARND SUNSET...
THEN WINDS SETTLE BACK DOWN. AFTER 03Z...CHCS INCRS OF HAVING A
LOW LAYER OF CLOUDS...ARND 3 KFT...MOVE IN FROM THE NW. TIMING
LOOKS BEST TO HAVE IT MOVE OVER MSP IN THE 06Z-12Z TIMEFRAME BUT
THERE IT COULD MOVE IN EARLIER THAN THAT.
OUTLOOK...SERIES OF FRONTS WILL PUSH THROUGH THE REGION TUE
THROUGH FRI...RESULTING IN FREQUENT WIND SHIFTS AND MOSTLY CLOUD
CONDITIONS INCLUDING OCNL MVFR CIGS TUE AND WED. PRECIP CHCS
INCREASE THU AND FRI WITH STRONGER SYSTEMS AND DEEPER
MOISTURE...THUS BRINGING IN BETTER CHCS FOR IFR CIGS AND POSSIBLE
MVFR/IFR VSBYS IF S- IS STRONG ENOUGH BUT THIS IS TOO EARLY TO
TELL ATTM.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...WIND ADVISORY UNTIL NOON CST MONDAY FOR BROWN-LAC QUI PARLE-
REDWOOD-WATONWAN-YELLOW MEDICINE.
WI...NONE.
&&
$$
JPC
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
329 AM EST MON DEC 26 2011
.SYNOPSIS...
A DEEPENING LOW PRESSURE SYSTEM IS EXPECTED TO TRACK NORTHEAST FROM
LOUISIANA TODAY AND REACH TENNESSEE AND KENTUCKY EARLY TUESDAY. HIGH
PRESSURE WILL BE BACK IN CONTROL FROM WEDNESDAY UNTIL THE WEEKEND
WHEN A COLD FRONT WILL APPROACH THE AREA FROM THE WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
DENSE FOG AND LOW CLOUDS CONTINUES ACROSS THE CENTRAL AND EASTERN
PARTS OF THE UPSTATE AND THE EXTREME SRN PIEDMONT OF NORTH CAROLINA.
DRY AIR WILL CONTINUE TO WORK SLOWLY TO THE SOUTH...GRADUALLY MIXING
OUT THE FOG AND LOW CLOUDS. THE RUC AND NAM CONDENSATION PRESSURE
DEFICITS IMPLY LOW CLOUDS AND FOG ARE LIKELY TO PERSIST THE LONGEST
ACROSS GREENVILLE...SPARTANBURG AND LAURENS COUNTIES IN A WEAK LLVL
CONVERGENCE AXIS. WE HAVE A DENSE FOG ADVISORY OVER PARTS OF THE
AREA THROUGH 6 AM. IT WILL LIKELY NEED TO BE CANCELLED EARLY OVER
THE WESTERN UPSTATE AND NE GA...BUT IT STILL LOOKS GOOD FARTHER TO
THE EAST.
A STRONG UPPER LOW OVER WEST TEXAS THIS MORNING WILL EJECT QUICKLY
ACROSS THE LOWER MISSISSIPPI VALLEY TONIGHT AND LIFT ACROSS THE SRN
APPALACHIANS ON TUE AS AN OPEN WAVE. SFC CYCLOGENESIS WILL OCCUR
THIS AFTERNOON OVER THE NRN GULF...WITH THE LOW MOVING ACROSS THE
SRN APPS ON TUE. THE LATEST NAM AND GFS MODEL DATA IS A LITTLE
COLDER ACROSS THE NC MTNS TONIGHT. THE NAM HAS A LARGE AREA OF
1305-1310 METER 1000-850 MB THICKNESSES ACROSS THE SW AND CENTRAL
MTNS AT 0900 UTC...WHICH RETREAT UP ACROSS THE NRN MTNS BY 12 UTC.
NAM MODEL SOUNDINGS AT FRANKLIN AND CASHIERS IMPLY A PERIOD OF SLEET
AND FREEZING RAIN STARTING AFTER MIDNIGHT...WITH PCPN CHANGING TO
ALL RAIN TOWARD MORNING. THE GFS IS A LITTLE WARMER AND LOOKS TO BE
MAINLY LIQUID...WITH JUST A LITTLE SLEET AND A FEW PATCHES OF
FREEZING RAIN AT ONSET. IT STILL APPEARS THAT THE BULK OF THE
COOLING WITH THIS EVENT WILL BE DRIVEN BY OROGRAPHIC ASCENT AS A 60+
KT LLVL WARM SECTOR JET CROSSES THE MTNS. THIS SHOULD CONFINE
WINTRY PCPN TO SOUTH AND EAST REACHES OF THE MTNS...WITH DOWNSLOPE
HELPING TO WARM THE BNDRY LAYER CLOSER TO THE TN LINE. ALSO...NONE
OF THE MODELS IMPLY THAT WINTRY WX WILL HOLD ON ONCE THE HEAVIER
RAIN STARTS OWING TO A STRONG WARM NOSE UP AROUND H8. STILL...A
PERIOD OF LIGHT FREEZING RAIN AND SOME SLEET LOOKS LIKELY ACROSS
THE SW MTNS...AND ALSO ACROSS THE EASTERN ESCARPMENT OF THE BLUE
RIDGE UP IN THE NRN MTNS. AT THE MOST...THIS SHOULD BE A LOW END
ADVISORY LEVEL EVENT WITH ANY GLAZE CONFINED MAINLY TO ELEVATED
SFCS...AND IT WON/T AFFECT THE MTNS UNTIL WELL AFTER DARK TONIGHT.
THEREFORE...I/M GOING TO HOLD OFF ON ANY ADVISORIES WITH THIS
PACKAGE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 315 AM MONDAY...THE MODELS ARE IN VERY GOOD AGREEMENT ON THE
POSITION OF THE UPPER SHORTWAVE AND SFC LOW PRESSURE AT 12Z TUESDAY.
AN IN SITU WEDGE WILL STILL BE IN PLACE ACRS THE CWFA...WITH SELY
850 MB WINDS OF 50-65 KTS ALOFT. VERY STRONG LLVL WAA AND MECHANICAL
LIFT WITH DEEP MOISTURE WILL BE AIDED BY DECENT QG FORCING AND UPPER
DIVERGENCE. SO A NEAR 100% POP TUESDAY MORNING SEEMS APPROPRIATE.
THERE ARE SOME DIFFERENCES AMONGST THE THERMAL PROFILES/SFC TEMPS
INVOF THE NC MTNS...HOWEVER...AS DYNAMICAL COOLING MAY LOCK IN
SUB-FREEZING TEMPS INVOF THE EAST-FACING SLOPES OF THE NRN MTNS/BLUE
RIDGE ESCARPMENT PAST DAYBREAK TUESDAY MORNING...WITH SOME
ADDITIONAL ICING POSSIBLE. ALL GUIDANCE HAS TEMPS WARMING ABOVE
FREEZING BY 15Z TUE...SO IT STILL LOOKS LIKE ANY TRAVEL PROBLEMS DUE
TO ICE SHUD BE OVER BY MIDDAY.
MIDDAY TUESDAY...THE LOW PRESSURE SYSTEM WILL QUICKLY LIFT
NORTHEASTWARD...WITH A PRIMARY LOW TRACKING ACRS THE TN/OH
VLYS...AND A TRIPLE POINT LOW TRACKING FROM CENTRAL GA TO CENTRAL NC
BY LATE AFTN. THE NAM/GFS/ECWMF ARE IN GOOD AGREEMENT ON THE GSP/CAE
CWFA BORDER AS AN APPROXIMATE TRACK OF THE TRIPLE POINT. SO INSTBY
LOOKS TO STAY SOUTH OF THE FA. THAT IS GOOD...BECAUSE HELICITY
VALUES WILL BE THRU THE ROOF...AND VERY LITTLE INSTBY WOULD BE
SUFFICIENT FOR A SMALL TORNADO/WIND THREAT. THE COLD/OCCLUDED FRONT
WILL CROSS FROM SW TO NE DURING THE AFTN HOURS...QUICKLY TAPERING
OFF POPS (EXCEPT FOR UPSLOPE ALONG TN/NC BORDER). STORM TOTAL QPF
LOOKS TO BE A SOLID 1-1.5" CWFA-WIDE...WITH 2-3" ALONG THE BLUE
RIDGE ESCARPMENT FROM HENDERSON COUNTY WEST. THERE COULD BE A FEW
HYDRO CONCERNS IN THOSE AREAS...BUT NOT WIDESPREAD ENUF TO WARRANT
ANY FLOOD WATCHES ATTM. WITH CLOUDS AND PRECIP...TEMPS WILL BE HELD
DOWN TO MAINLY MID-UPR 40S...EXCEPT ALONG SOUTHEAST EDGE NEAR THE
TMB/WEDGE BNDRY WHERE THEY WILL BE IN THE MID 50S OR HIGHER.
TUESDAY NIGHT...THERE WILL BE STRONG LLVL CAA ACRS THE FA IN THE
WAKE OF THE DEPARTING LOW...WITH GOOD NW FLOW UPSLOPE FORCING ALONG
THE TN/NC BORDER. BOTH THE NAM AND GFS IMPLY AT LEAST SCATTERED
SHOWER ACTIVITY...AND SNOW LEVELS SHUD FALL QUICKLY DURING THE
EVENING HOURS. SOME LOCATIONS MAY GET A QUICK INCH OR TWO
(ESPECIALLY ABOVE 3500 FT). THE SHOWER ACTIVITY LOOKS TO QUICKLY
TAPER OFF BY LATE WEDNESDAY MORNING. TEMPS ACRS THE ENTIRE AREA WILL
BE NEAR NORMAL.
WEDNESDAY AND WEDNESDAY NIGHT...GENERAL UPPER LEVEL TROFINESS
LINGERS...AS WEAK SFC HIGH PRESSURE BUILDS IN ACRS THE AREA. HIGH
TEMPS WILL BE AT OR A CATEGORY BELOW NORMAL AND OVERNIGHT LOWS
AROUND NORMAL UNDER GENERALLY CLEAR SKIES.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AT 220 AM EST MONDAY...ON THURSDAY THE MEDIUM RANGE MODELS SHOW
SURFACE HIGH PRESSURE CENTERED OVER THE GULF COAST AT THE FLORIDA
PANHANDLE WHILE CUTTING OFF ANY MOISTURE FLOW TO OUR REGION. FAIRLY
VIGOROUS VORT MAXES CROSSING THE AREA BUT NO MOISTURE TO WORK WITH.
ON FRIDAY...THE SURFACE HIGH SHIFTS EAST TO FLORIDA AND FARTHER EAST
AND SOME MOISTURE FLOW STARTS FROM THE WESTERN GULF AS A SHORTWAVE
DROPS DOWN FROM THE NORTHERN MISS VALLEY AND OHIO VALLEY. THIS
SHORTWAVE REACHES THE APPALACHIANS FRIDAY NIGHT AND SOME NORTHWEST
FLOW MOISTURE ALIGNS ALONG THE UPSLOPE REGION ALONG THE TENNESSEE
AND NORTH CAROLINA BORDER. THE FAST MOVING SHORTWAVE HAS AN AXIS
NEAR THE WV / VA BORDER BY 12Z SATURDAY ON BOTH THE GFS AND ECMWF.
IF THERE IS ANY SNOW SHOWERS FOR THE NC MOUNTAINS NEAR THE TN
BORDER...THIS WILL BE BRIEF AND MAINLY IN THE WEE HOURS OF SATURDAY
ACCORDING TO THE CURRENT TIMING OF THE MODELS. THE LATEST ECMWF
JUST CAME IN AND MUCH DRIER WITH ONLY A HINT OF ANY PRECIP FAR
NORTHERN MOUNTAINS AROUND 12Z SATURDAY. THE ENERGY WITH THE
SHORTWAVE IS FARTHER NORTH WITH THIS EC RUN. AT THIS POINT...NOT
FEELING CONFIDENT AND LEAVING NO MORE THAN 14 POP...JUST BELOW
SLIGHT POPS.
WEAK HIGH PRESSURE CENTERED OVER OUR REGION SATURDAY NIGHT. RETURN
FLOW BEGINS OVER THE LOWER MISS VALLEY SATURDAY NIGHT AHEAD OF THE
NEXT SHORTWAVE. THIS NEXT SHORTWAVE IS QUITE DIFFERENT ON THE GFS
COMPARED TO THE ECMWF. THE GFS HAS A STRONG SHORTWAVE CROSSING
GREAT LAKES AND OHIO VALLEY SUNDAY AND LOWERING THICKNESS VALUES
SUNDAY NIGHT FOR OUR AREA...ESPECIALLY IN NC. VERY LITTLE MOISTURE
ON GFS. HOWEVER...THE ECMWF HAS A DEEP CUT OFF UPPER LOW CROSSING
MISSOURI LATE SUNDAY NIGHT WITH ASSOCIATED COLD FRONT REACHING OUR
AREA NEAR 12Z MONDAY WITH GOOD SOUTHERN FLOW FROM THE GULF. THIS
LATEST EC IS QUITE DIFFERENT FROM THE PREVIOUS RUN AND THE SUNDAY
NIGHT PERIOD IS THE EXTRA PERIOD THAT DOES NOT COUNT IN THE CURRENT
SEVEN DAY FORECAST. THUS WE WILL SEE AS THE TIME GETS CLOSER TO
THAT POINT.
TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL WITH SLIGHT FALLS
WITH PASSING SHORTWAVES.
&&
.AVIATION /09Z MONDAY THROUGH FRIDAY/...
AT KCLT...A SHARP DEWPOINT GRADIENT WAS LOCATED JUST TO THE
NORTHWEST OF THE AIRFIELD AT TAF ISSUANCE TIME. SOUTH OF THE BNDRY
WIDESPREAD DENSE FOG AND/OR VLIFR STRATUS HAS DEVELOPED. DRY AIR
WILL VERY SLOWLY PUSH TO THE SOUTH OVERNIGHT...BUT IT WILL BE A
COUPLE HOURS YET UNTIL THE DRY AIR WORKS IT/S WAY ACROSS THE
AIRFIELD WITH A WIND SHIFT TO THE NORTHWEST AND IMPROVING
CONDITIONS. SOME GUIDANCE TAKES EVEN LONGER TO BRING THE BNDRY
THROUGH...BUT BASED ON THE GUSTY WINDS AT KHKY AND 25 DEG DEWPOINT
AT KIPJ...I THINK THAT CONDITIONS WILL IMPROVE AT KCLT AFTER 0800
UTC.
AND ELSEWHERE...DRY AIR AND A WEAK COLD FRONT HAVE PUSHED THROUGH
KAVL AND KHKY WHICH WILL SEE NORTHWEST WINDS AND VFR CONDITIONS THE
REST OF THE NIGHT. OVER THE UPSTATE THE BNDRY HAS ONLY JUST MOVED
OFF THE ESCAPEMENT...AND IT WILL MOVE VERY SLOWLY...IF AT
ALL...OVER THE NEXT SEVERAL HOURS. DENSE FOG AND VLIFR CIGS HAVE
DEVELOPED IN THE MOIST AIR AHEAD OF THE BNDRY...AND THESE CONDITIONS
ARE EXPECTED TO PERSIST FOR THE NEXT 3 HRS OR SO AT THE THREE
UPSTATE AIRFIELDS. EVENTUALLY THE STRATUS AND FOG WILL BE PUSHED
SOUTH OF I-85...BUT A CONVERGENCE AXIS MAY HOLD IN LOW CIGS THROUGH
SUNRISE...ESPECIALLY AT KGMU AND KAND...WHICH IS WHAT I/VE DONE IN
THE TAFS. CONDITIONS THE REST OF THE DAY WILL BE GOOD WITH VFR
CONDITIONS AND LIGHT AND VARIABLE WINDS UNDER A RIDGE OF HIGH
PRESSURE.
OUTLOOK...LOW PRES WILL MOVE N FROM THE W GULF MON NIGHT AND INTO
THE FORECAST AREA TUE...BRINGING WIDESPREAD PRECIPITATION AND LOW
RESTRICTIONS. DRYING IS EXPECTED TUE NIGHT...WITH LINGERING NW FLOW
MOISTURE NEAR KAVL. CONDITIONS DRY OUT ACROSS THE AREA MID TO LATE
WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
GAZ018-026-028-029.
NC...DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
NCZ070>072-082.
SC...DENSE FOG ADVISORY UNTIL 6 AM EST EARLY THIS MORNING FOR
SCZ004>014-019.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY
SHORT TERM...ARK
LONG TERM...DEO
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS AUSTIN/SAN ANTONIO TX
1148 PM CST SUN DEC 25 2011
.AVIATION...
MVFR AT KAUS/KSAT/KSSF SHOULD STAY MVFR THROUGH THE NIGHT AS THE
UPPER LOW OVER WEST TEXAS SLOWLY BEGINS TO MOVE EAST. DECIDED TO
KEEP -DZ INTO THE I-35 TAFS...IT SHOULD BE VERY LIGHT AND NOT POSE
AN ICING PROBLEM UP TO ABOUT 10500 FT MSL AT THE FREEZING LEVEL.
DRIER AIR BEHIND THE UPPER LOW WILL BEGIN TO LIFT CIGS BY 15Z AND
YIELD CLEAR SKIES BY 00Z TUE.
&&
.PREV DISCUSSION... /ISSUED 946 PM CST SUN DEC 25 2011/
UPDATE...
PREVIOUS WEATHER FORECAST IS ON TRACK FOR THIS EVENING INTO MONDAY.
HOWEVER...LOWER MIN TEMPS FROM 1-3 DEGREES FROM WEST OF I 83 BASED
ON CURRENT TEMPS ACROSS THE VAL VERDE AND EDWARDS PLATEAU AREAS
AND THE LATEST NAM AND RUC SOLUTIONS. UPDATED ZONE OUT SHORTLY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AUSTIN CAMP MABRY 39 55 36 62 37 / 20 30 0 0 0
AUSTIN BERGSTROM INTL AIRPORT 40 55 30 62 30 / 20 30 0 0 0
NEW BRAUNFELS MUNI AIRPORT 42 56 32 64 34 / 20 30 0 0 0
BURNET MUNI AIRPORT 34 52 31 59 32 / 20 20 - 0 0
DEL RIO INTL AIRPORT 30 59 34 64 35 / - - 0 0 0
GEORGETOWN MUNI AIRPORT 38 52 33 60 33 / 20 30 - 0 0
HONDO MUNI AIRPORT 40 59 28 65 31 / 10 10 0 0 0
SAN MARCOS MUNI AIRPORT 41 55 32 63 33 / 20 30 0 0 0
LA GRANGE - FAYETTE REGIONAL 43 53 36 62 35 / 30 50 10 0 0
SAN ANTONIO INTL AIRPORT 41 58 36 65 37 / 20 20 0 0 0
STINSON MUNI AIRPORT 43 59 34 66 36 / 20 20 0 0 0
&&
.EWX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
MESOSCALE/AVIATION...26
SYNOPTIC/GRIDS...17
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSONVILLE FL
940 AM EST MON DEC 26 2011
.UPDATE...COLD FRONT IS JUST S OF THE AREA WITH HIGH PRES CENTERED
OVER THE TN VALLEY AREA. MEAN LAYER HIGH PRES RIDGE IS W OF THE
AREA AND WILL BUILD IN THROUGH THE DAY RESULTING IN WEAK SUBSIDENCE
PATTERN INTO LATE AFTN. SATELLITE IMAGERY SHOWS MULTILAYERED
CLOUDS ACROSS THE AREA WITH RUC INDICATING DEEPEST MOISTURE
RESIDING OVER NE FL THROUGH THE DAY WITH LLVL FLOW NE BECOMING E.
BREEZY CONDS LIKELY TO PERSIST ALONG THE COASTAL AREAS MOST OF
THE DAY.
REST OF TODAY...MOSTLY CLOUDY CONDS EXPECTED TO PREVAIL ACROSS NE
FL AS THE FRONT TO THE S BECOMES STATIONARY AND FLOW ALOFT STARTS
TO VEER AND RESULT IN ISENTROPIC ASCENT. MEANWHILE...PARTLY CLOUDY
CONDS WILL DEVELOP OVER SE GA THOUGH BROKEN HIGH CLOUDS LIKELY
THROUGH THE DAY THANKS TO UPSTREAM SYSTEM OVER TX AND LOWER MS
VALLEY. SOME LIGHT RAIN WILL BE POSSIBLE BY LATE AFTN OVER THE WRN
ZONES WITH THE APPROACH OF THE TROUGH TO OUR W BUT WILL PROBABLY
KEEP SILENT 10% FOR NOW. A FEW LIGHT SHOWERS POSSIBLE ALONG THE
COAST S OF JAX DUE TO MOIST NE FLOW...OTHERWISE DRY FCST TODAY.
TEMPS WILL STRUGGLE THROUGH THE 60S MOST AREAS WITH LOWER 70S
ANTICIPATED S/SW ZONES...WITHIN A FEW DEGREES OF CLIMATE.
&&
.AVIATION...VFR CONDS EXPECTED TO PREVAIL THOUGH SOME BRIEF OCCASIONS
OF MVFR CIGS POSSIBLE AT GNV OVER THE NEXT FEW HRS. NELY WINDS
WILL BE AROUND 10-15G25KT. CIGS LOOK TO STAY AOA 5 KFT THROUGH
00Z...THEN MAINLY MVFR CIGS AND VSBY WITH SHOWERS DEVELOPING AS A
COLD FRONT APPROACHES. LLWS ALSO EXPECTED LATE.
&&
.MARINE...MODERATE NNE BREEZE OVER THE WATERS WITH OBS SHOWING 15-20
KT. WINDS EXPECTED TO SHIFT TO NE AND THEN E AS HIGH PRES N OF THE
AREA MOVES EWD. SEAS ARE 1-2 FT LOWER COMPARED TO GUID/FCST RIGHT
NOW BUT SHOULD NUDGE UP THROUGH THE DAY DUE TO N-NELY FETCH. CURRENT
HEADLINES LOOK ON TRACK AT THIS TIME.
RIP CURRENTS: INCREASED SURF CONDS EXPECTED FROM AROUND 2-3 FT TO
NEAR 3-5 FT AND WILL RESULT IN MODERATE RISK TODAY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 64 52 64 38 / 10 80 80 10
SSI 61 60 68 44 / 10 50 80 20
JAX 65 59 72 43 / 10 50 80 20
SGJ 66 65 73 47 / 10 40 80 20
GNV 70 59 72 42 / 10 40 80 20
OCF 72 60 74 45 / 10 30 80 20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...SMALL CRAFT ADVISORY UNTIL 8 AM EST WEDNESDAY FOR ALTAMAHA SOUND
GA TO FERNANDINA BEACH FL 20 NM TO 60 NM OFFSHORE-
FERNANDINA BEACH TO ST AUGUSTINE FL 20 NM TO 60 NM OFFSHORE-
ST AUGUSTINE TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
&&
$$
SHASHY/WALKER
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
618 AM CST MON DEC 26 2011
.AVIATION...
FOR THE 12Z TAF ISSUANCE...
DESPITE THE SCATTERED SPRINKLES AND VERY LIGHT SNOW ACROSS
PORTIONS OF SOUTHWEST/SOUTH CENTRAL KANSAS EARLY THIS
MORNING...FLIGHT CATEGORY HAS REMAINED VFR. THE UPPER LOW WILL BE
MOVING AWAY FROM THE REGION TODAY AND SO WILL THE LOW TO MID LEVEL
STRATUS CLOUD COVER. WINDS WILL INCREASE BY LATE THIS
AFTERNOON/EARLY THIS EVENING AS A SURFACE TROUGH MOVES EAST ACROSS
WESTERN KANSAS. NORTHWEST WINDS THIS EVENING SHOULD BE ABOVE 12
KNOTS WITH HIGHER GUSTS 00Z TO 06Z BEHIND THE FRONT.
&&
.PREV DISCUSSION... /ISSUED 222 AM CST MON DEC 26 2011/
SYNOPSIS...
MID AND UPPER AIR ANALYSIS INDICATES A SHORTWAVE TROUGH PUSHING ACROSS
MONTANA. A 500 HPA LOW WAS SPINNING ACROSS THE WESTERN TEXAS PANHANDLE.
MOISTURE ADVECTION WAS EVIDENT ON THE KDDC RAOB AS THE MIDDLE ATMOSPHERE
MOISTENED UP CONSIDERABLY IN THE 12 HOUR GAP BETWEEN SYNOPTIC FLIGHTS.
KDDC WSR-88D WAS DETECTING SOME LIGHT ECHOES ACROSS SOUTH CENTRAL KANSAS.
A QUICK CALL MADE TO BARBER COUNTY INDICATES SOME SPRINKLES WERE OCCURRING
WITHIN THE COUNTY. -SUGDEN
DISCUSSION...
DAYS 1-2...
TODAY:
THE IMMEDIATE SHORT TERM CONCERN WAS TO TREND POPS AND WX TO RADAR TRENDS
ACROSS SOUTH CENTRAL KANSAS. THIS ACTIVITY WAS IN RESPONSE TO 600-700
HPA FRONTOGENESIS. HAVE FOLLOWED HRRR GUIDANCE ON THE DEPARTURE OF THIS
ACTIVITY THROUGH THE MORNING. FORECAST SOUNDINGS SHOW A DRY THERMODYNAMIC
PROFILE BELOW 850 HPA SO THINK MOST OF THIS ACTIVITY IS EVAPORATING
BEFORE REACHING THE SURFACE. HAVE KEPT 15 PERCENT POPS IN THE GRIDS
AND WILL QUICKLY TAPER TO ZERO TOWARDS 15Z THIS MORNING. OTHER CONCERN
IS A 5KFT STRATUS LAYER THAT HAS SPREAD ACROSS MUCH OF SOUTHWEST KANSAS.
THINK THIS WILL MOVE OFF TO THE EAST AND REDUCE IN AERIAL COVERAGE WITH
MIXING TOWARDS MID MORNING.
MEANWHILE, THE AFOREMENTIONED UPPER LEVEL SHORTWAVE TROUGH MENTIONED
IN THE SYNOPSIS WILL USHER IN A COLD FRONT TONIGHT. PRECIPITATION IS
NOT EXPECTED ALONG THE BOUNDARY AS THE ATMOSPHERE IS FAIRLY DRY AND
DRY AIR ADVECTION WILL CONTINUE IN THE WAKE OF THE SURFACE BOUNDARY.
THE MAIN IMPACTS FROM THE DENSITY GRADIENT WILL BE A SHIFT IN THE WINDS.
HIGHS TODAY WILL BE MAINLY IN THE 30S DEG F FOR MUCH OF THE COUNTY WARNING
AREA EXCEPT TOWARDS SOUTH CENTRAL KANSAS WHERE 40S DEG F ARE FORECAST.
A CONTINUATION OF THE EROSION OF THE SNOWPACK IS EXPECTED TODAY, PARTICULARLY
ACROSS THE EASTERN SECTIONS OF THE SNOWPACK.
TONIGHT:
POST FRONTAL 10 TO 15 KT NORTHWESTERLY TO NORTHERLY WINDS ARE EXPECTED
TONIGHT AND THROUGH THE OVERNIGHT HOURS. MINIMUMS SHOULD BE WARMER HEADING
INTO TUESDAY MORNING AS WINDS CONTINUE IN THE 5 TO 10 KT RANGE OVERNIGHT AND
PROVIDE SLIGHTLY MORE MIXING. TEENS TO UPPER 20 DEG F ARE EXPECTED ACROSS
THE REGION WITH THE COOLEST TEMPERATURES ACROSS MY NORTHWEST COUNTIES.
TUESDAY:
A SURFACE RIDGE OF HIGH PRESSURE WILL SLIDE ACROSS KANSAS TUESDAY.
SOUTHERLY WINDS ARE EXPECTED ON THE BACKSIDE OF THE HIGH BY TUESDAY
EVENING ACROSS WESTERN KANSAS. LOW 50S DEG F TEMPERATURES ARE POSSIBLE
TOWARDS P28 TOMORROW. OTHERWISE MOST OF THE REGION SHOULD BE IN THE
UPPER 30S DEG F (MAINLY ACROSS SNOWPACK) AND 40S DEG F ACROSS BARE GROUND.
THE SNOWPACK WILL CONTINUE TO ERODE THROUGH THE DAY ON TUESDAY.
TUESDAY NIGHT:
I HAVE INCREASED CLOUD COVER TUESDAY EVENING INTO WEDNESDAY MORNING
AS MID TO UPPER LEVEL SATURATION IS INDICATED BY FORECAST SOUNDINGS
AHEAD OF A SECONDARY APPROACHING SHORTWAVE TROUGH MOVING ACROSS THE
PLAINS. MODELS ARE NOT INDICATING ANY QPF WITH THIS SYSTEM SO STILL
HAVE POPS AT ZERO THROUGH THE EVENING. FORECAST SOUNDINGS ALSO SHOW
A DRY PROFILE BELOW 700 HPA WHICH SUPPORTS A DRY FORECAST. -SUGDEN
DAYS 3-7...
THE MEDIUM RANGE FORECAST CONTINUES TO LOOK WARM AND DRY IN A PROLONGED
DOWNSLOPE-FAVORED UPPER AIR PATTERN...WITH NO HAZARDOUS WINTER WEATHER
EXPECTED FOR MUCH OF THE WESTERN PLAINS. THAT BEING SAID...WILL BE WATCHING
FOR POSSIBLE STORM DEVELOPMENT EAST OF HERE AROUND THE 1ST OF JANUARY
AS THE LARGE SCALE CIRCULATION REGIME AMPLIFIES.
WEDNESDAY-FRIDAY:
WEST-NORTHWESTERLY DOWNSLOPE MOMENTUM WILL YIELD A WARMING LOWER TROPOSPHERE
AND DAILY TEMPERATURES WARMING INTO THE 50S. WHATEVER SNOWPACK REMAINS
BY WEDNESDAY WILL BE TAKING A SERIOUS HIT DURING THIS TIME FRAME WITH
ALMOST NO INFLUENCE AT ALL OF SNOWPACK ON TEMPERATURES BY THE END OF
THE WEEK AS MUCH OF IT SHOULD BE MELTED BY THEN (EXCEPT FOR THE COLORADO
BORDER AREAS). HIGHS IN THE MID 50S ARE LIKELY AND PERHAPS A FEW 60
DEGREE READINGS WILL OCCUR ACROSS SOUTH-CENTRAL KANSAS ZONES THURSDAY
AND FRIDAY.
SATURDAY-SUNDAY:
A LARGE RIDGE IS EXPECTED TO FORM ALONG THE WEST COAST/WESTERN CONUS
WHICH WILL FAVOR A DOWNSTREAM TROUGH DEVELOPMENT OVER THE CENTRAL/EASTERN
PLAINS. THE FORMATION OF THIS TROUGH IS SHOWN BY ALL THE GLOBAL MODELS
TO BE OVER OR EAST OF WESTERN KANSAS WHICH DOES NOT FAVOR WIDESPREAD
ACCUMULATING PRECIPITATION GIVEN UNFAVORABLE LOW LEVEL TRAJECTORIES
TO OUR SOUTH (MOISTURE ADVECTION). A MID LATITUDE CYCLONE OF SOME SEMBLANCE
WILL PROBABLY MATURE OVER THE MIDWEST /OHIO-VALLEY AS A RESULT OF THIS
TROUGH DEVELOPMENT WITH STRONG, DRY NORTHWEST WINDS ACROSS THE WESTERN
PLAINS ON THE ORDER OF LATE SATURDAY INTO SUNDAY. SINCE THIS IS STILL
IN THE DAY 6-7 TIME RANGE THERE IS STILL SOME UNCERTAINTY AS TO WHEN/WHERE
(OR EVEN IF) EXACTLY A STORM WILL FORM SO WILL HAVE TO WATCH SUBSEQUENT
MODEL SOLUTIONS TO SEE HOW THIS TROUGH DEVELOPS AND IF IT WILL HAVE
ANY SUBSTANTIAL SENSIBLE WEATHER IMPACTS ON SOUTHWEST KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 36 21 42 23 / 0 0 0 0
GCK 33 17 37 19 / 0 0 0 0
EHA 35 21 43 25 / 0 0 0 0
LBL 36 19 45 22 / 0 0 0 0
HYS 37 23 41 25 / 20 0 0 0
P28 44 26 50 26 / 20 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN99/99/25
AREA FORECAST DISCUSSION
NWS GOODLAND KS
358 AM MST MON DEC 26 2011
.SYNOPSIS...
LATEST IR SATELLITE IMAGERY AND RUC ANALYSIS SHOWED A SHORT WAVE
TROUGH MOVING ACROSS THE NORTHERN CONUS WITH AREAS OF CLOUDS AHEAD
OF IT. FURTHER SOUTH THE CLOSED LOW CONTINUES TO SPIN OVER EASTERN
NEW MEXICO AND WESTERN TEXAS. CURRENT RADAR SHOWS ECHOES OVER
SOUTHWEST KANSAS AS SOME MOISTURE MOVES UP FROM THE CLOSED LOW...WITH
A FEW SPRINKLES AND LIGHT SNOW REACHING THE GROUND. AT THE SURFACE
A HIGH PRESSURE WAS PROGRESSING OUT OF THE TRI-AREA AHEAD OF THE
PRE-FRONTAL TROUGH THAT WILL MOVE THROUGH TODAY.
JTL
&&
.SHORT TERM (TODAY-WEDNESDAY)...
227 AM MST MON DEC 26 2011
TEMPERATURES WILL BE THE MAIN FOCUS FOR THIS PERIOD.
TODAY A PRE-FRONTAL SURFACE TROUGH WILL MOVE THROUGH THE AREA DURING
THE DAY...CAUSING THE SOUTHWEST WINDS TO SHIFT TO THE NORTHWEST.
WITH LITTLE MOISTURE TO WORK WITH...AM ONLY ANTICIPATING STRONGER
WINDS AND A FEW CLOUDS BEHIND THE TROUGH. HIGH TEMPERATURES WILL BE
SIMILAR TO YESTERDAY.
TUESDAY THROUGH WEDNESDAY...ANOTHER SURFACE AND UPPER LEVEL TROUGH
WILL MOVE THROUGH THE TRI-STATE AREA DURING THE LATE AFTERNOON AND
EVENING HOURS. SOUNDINGS AND CROSS SECTIONS SHOW UPPER LEVEL
MOISTURE INCREASING AS THE TROUGH MOVES THROUGH. THERE ALSO IS SOME
INSTABILITY PRESENT...ALONG WITH LIFT FROM FRONTOGENESIS AND WARM
AIR ADVECTION AS THE TROUGH MOVES THROUGH. HOWEVER A NARROW LAYER
OF MUCH DRIER AIR BETWEEN THE SURFACE AND THE MOISTURE MAY HINDER
ANY PRECIPITATION FROM REACHING THE GROUND. CANNOT COMPLETELY RULE
OUT SOMETHING FROM REACHING THE GROUND SO WILL ADD A MENTION OF
FLURRIES FOR AREAS NORTH OF A BENKELMAN TO HILL CITY LINE. TEMPERATURES
WILL BE COOLER TUESDAY AS SLIGHTLY COOLER AIR WILL MOVE IN BEHIND
MONDAY/S TROUGH. WEDNESDAY THE ENVIRONMENT DRIES OUT BEHIND THE
TROUGH. TEMPERATURES WILL BE WARMER AS 850MB TEMPERATURES
INCREASE.
JTL
.LONG TERM (THURSDAY-SUNDAY)...
227 AM MST MON DEC 26 2011
A SERIES OF WEAK SHORT WAVE TROUGHS WILL MOVE ACROSS
THE HIGH PLAINS THROUGH THE REST OF THE WEEK...BUT BEST LIFT AND
MOISTURE WILL BE FAR NORTH OF THE FORECAST AREA. MODELS INDICATE THE
BEST CHANCE FOR ANY PRECIPITATION WOULD BE TOWARD THE END OF THE
PERIOD...SATURDAY NIGHT/SUNDAY MORNING. MODELS DIFFER IN THEIR
SOLUTIONS AT THAT TIME. THE ECMWF IS FURTHER SOUTH AND WEST WITH
DYNAMICS AND MOISTURE THAN THE GFS. WITH ENSEMBLES SHOWING WIDE
VARIABILITY AFTER 120 HOURS...WILL STAY THE COURSE OF A DRY
FORECAST. TEMPERATURES WILL BE ABOVE NORMAL WITH DAILY MAXIMUM
TEMPERATURES MAINLY IN THE 50S.
&&
.AVIATION...
358 AM MST MON DEC 26 2011
VFR CONDITIONS WILL CONTINUE AT KGLD/KMCK. A WEAK COLD FRONT WILL
MOVE ACROSS BOTH SITES AROUND 18Z SWITCHING SURFACE WINDS TO THE
NORTHWEST AND PRODUCING GUSTS TO 25 KNOTS THROUGH THE AFTERNOON.
OTHERWISE...ONLY CIRRUS IS EXPECTED.
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
958 AM EST MON DEC 26 2011
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE DRY WEATHER AND SEASONABLE TEMPERATURES
TODAY. A STORM SYSTEM WILL BRING A MIX OF RAIN AND SNOW TO THE AREA
TUESDAY AND THEN SNOW TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
15Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ADJUST
SKY GRIDS, ACCOUNTING FOR LINGERING STRATOCUMULUS DECK ACROSS MUCH
OF THE AREA. OTHERWISE, LITTLE CHANGE TO THE GOING FORECAST.
THE LATEST RUC ANALYSIS INDICATES A WEAK 500MB RIDGE CENTERED
ACROSS THE WESTERN GREAT LAKES WITH THE UPPER OHIO VALLEY IN A
NORTHWESTERLY FLOW AHEAD OF THIS FEATURE. MOIST 850MB FLOW OFF OF
LAKE ERIE IS ALLOWING FOR STRATOCUMULUS TO HANG AROUND THIS
MORNING. AT THE SURFACE, A 1030MB HIGH IS CENTERED ACROSS
KENTUCKY. THIS FEATURE IS MOVING NORTHEAST TOWARD THE AREA,
CONTRIBUTING TO THE ERODING CLOUD DECK WITH CLEARING IN EASTERN
OHIO.
TODAY...THE WEAK RIDGE WILL MOVE ACROSS THE AREA WITH THE SURFACE
HIGH MOVING INTO THE MID-ATLANTIC. THIS WILL ALLOW FOR THE CLOUD
DECK TO ERODE, WITH MOSTLY SUNNY SKIES BY THIS AFTERNOON. CIRRUS
WILL THEN BEGIN TO ADVECT INTO THE AREA FROM THE SOUTHWEST THIS
EVENING. TAKING INTO ACCOUNT LATEST OBS, LAMP GUIDANCE, AND THE 12Z
KPIT SOUNDING, FORECAST TEMPS REMAIN A FEW DEGREES BELOW A MAV/MET
BLEND THIS AFTERNOON. HIGHS WILL RANGE FROM THE UPPER 30S ACROSS
THE EASTERN RIDGES AND I-80 CORRIDOR TO THE MID 40S IN PORTIONS OF
EASTERN OHIO AND NORTH-CENTRAL WV.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY/...
VERY DIFFICULT FORECAST TUESDAY AND TUESDAY NIGHT.
AT THE SFC, HIGH PRESSURE WILL MOVE OFF THE VA COAST LATE
TONIGHT. A SFC LOW WILL DEVELOP OVER THE GULF COAST STATES AND
MOVE INTO THE TN VALLEY BY DAWN TUESDAY.
AT THE UPPER LEVELS, EASTERN RIDGE WILL BEGIN TO BREAK DOWN
TONIGHT AS UL ENERGY MOVE ACROSS THE MIDWEST. ALSO, UL LOW WILL
MOVE ACROSS THE GULF COAST STATES. THESE TWO PIECES OF ENERGY WILL
BE EXTREMELY IMPORTANT TO TUESDAY`S FORECAST. THE NORTHERN
DISTURBANCE WILL HELP TO PUSH COLDER AIR TOWARD THE REGION. THE
SOUTHERN DISTURBANCE WILL PUSH MOISTURE NORTHWARD AND ALSO DEVELOP
THE SFC LOW. AT THIS POINT, IT APPEARS THAT THE SOUTHERN ENERGY
WILL WIN THE RACE INTO THE AREA.
WHAT THIS MEANS FOR THE FORECAST, IS MORE OF A RAIN EVENT ON
TUESDAY AS THE WARMER AIR WILL INITIALLY COVER THE AREA.
THE FIRST QUESTION TO DEAL WITH IS HOW QUICKLY WILL THE
PRECIPITATION BEGIN. MODELS CONTINUE TO SLOW THE ONSET OF
PRECIPITATION AS THE VERY DRY AIR MASS OVER THE MID-ATLANTIC WILL
NOT EASILY BE MOVED. WILL HOLD OFF ON A MENTION OF POPS UNTIL JUST
BEFORE DAWN TUESDAY OVER THE WEST. ON TUESDAY MORNING, WILL
INCREASE POPS FROM WEST TO EAST AS THE PRECIP SHIELD COVERS THE
ENTIRE AREA. CURRENT BELIEF IS THAT PRECIP WILL BEGIN AS RAIN AS
IT MOVES INTO THE AREA. HOWEVER, AS COLDER AIR MOVES ACROSS THE
MIDWEST, IT APPEARS THAT A MIX OF RAIN AND SNOW IS A GOOD
POSSIBILITY ACROSS THE NORTH AND WEST AS THE DAY PROGRESSES.
THE COLDER AIR SHOULD FINALLY OVERTAKE THE REGION TUESDAY EVENING ON
THE HEELS OF A SFC COLD FRONT. THIS WILL BRING A CHANGE OVER TO
ALL SNOW DURING THE EVENING HOURS. TIMING HERE IS STILL A BIG
QUESTION AS THERE CONTINUE TO BE MODEL DISCREPANCIES AND MANY
VARIABLES CONTRIBUTING TO THE COLD AIR INTRUSION.
RIGHT AFTER 00Z WED, MODELS ARE INDICATING A DEFORMATION ZONE
AND AREA OF MID-LEVEL FRONTOGENESIS DEVELOPING AND SWINGING
THROUGH THE AREA. THESE FEATURES HINT AT THE POSSIBILITY OF A
BAND OF ACCUMULATING SNOW DEVELOPING AND ROTATING THROUGH THE
AREA.
SFC LOW WILL DEEPEN OVER SE PA TUESDAY EVENING AND MOVE RAPIDLY
TOWARD THE NE. WITH THE SFC SYSTEM INCREASING FORWARD SPEED,
EXPECT THE SNOW TO TAPER OFF QUICKLY LATE TUESDAY NIGHT.
SFC HIGH WILL BUILD IN ON WEDNESDAY. TEMPERATURES WILL BE BELOW
NORMAL BUT CONDITIONS SHOULD BE DRY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FAST MOVING SYSTEMS IN PROGRESSIVE FLOW WILL BRING TEMPERATURES
AVERAGING ABOVE NORMAL AND CHANCES FOR RAIN OR SNOW SHOWERS FOR
LATE WEEK INTO THE WEEKEND. LONG TERM PERIOD WAS FORECAST CLOSE TO
HPC PROGS WHICH CONTINUE TO TREND TOWARD THE ECMWF.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
GRADUAL EROSION OF THE STRATOCU DECK IS FORECAST FOR THIS MORNING
AS FLOW IMMEDIATELY ABOVE THE BOUNDARY LAYER BACKS TO THE WEST.
EVENTUAL VFR FOR ALL PORTS...WITH SFC WND BACKING TO THE SW WL BE
THE FEATURES OF THE TAF PD.
OUTLOOK...MONDAY NIGHT THROUGH FRIDAY...
VFR MAY BE ANTICIPATED INTO TUE MRNG AS HIGH PRESSURE SLIDES OVR THE
REGION. ADVANCING LOW PRESSURE WL THEN SPREAD WIDESPREAD PCPN AND
RESTRICTIONS ON TUESDAY. BY TUESDAY EVE...ALL PCPN WL BE SNOW OVR
THE UPR OHIO VALLEY...BUT THE SYSTEM IS PROGGED TO RAPIDLY EXIT
NEWD...LEAVING COLD NW FLOW AND MVFR STRATOCU AND -SHSN FOR WED. THE
NXT CHC FOR WIDESPREAD RESTRICTIONS IS FORECAST TO COME WITH LATE
WEEK LOW PRESSURE OFF THE GREAT LAKES.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
845 AM CST MON DEC 26 2011
...PERIODS OF HEAVY RAIN TODAY WITH QUIETER WEATHER WEEK AHEAD...
.UPDATE...UPDATED TO EXPAND FLOOD WATCH TO ENCOMPASS ENTIRE FORECAST
AREA. MORE IN HYDRO SELECTION BELOW.
&&
.SHORT TERM...TODAY THRU TUESDAY NIGHT
NUMEROUS SHOWERS WITH SOME EMBEDDED THUNDERSTORMS ARE ONGOING THIS
MORNING ACROSS MUCH OF THE ARKLAMISS REGION AS A SMALL SW/V RESOLVED
BY RUC/NAM OUTPUTS AND WEAK ISENTROPIC UPGLIDE AID IN OVERALL LIFT IN
PRESENCE OF NEGATIVE SHOWALTERS. BOTH NMM/ARW SIM REFLECTIVITY DEPICT
THIS ACTIVITY WELL AS IT WILL CONTINUE TO MIGRATE EAST ALONG THE
HWY-84 CORRIDOR THIS MORNING. ISENTROPIC UPGLIDE AND DEEPER
ATMOSPHERIC LIFT WILL ONLY GET BETTER THROUGH THE LATE MORNING AND
ESPECIALLY IN THE AFTN/EVE HOURS AS MAIN MID-LVL CLOSED LOW PHASES
WITH NRN STREAM TROUGH AND PIVOTS ACROSS THE MID-SOUTH LATER TODAY
CAUSING WIDESPREAD SHOWERS/TSRA OVER ALL THE REGION.
INDUCED SFC CYCLOGENESIS WILL OCCUR ACROSS NRN GULF THIS AFTERNOON
AS MID-LVL LOW PIVOTS TOWARDS THE REGION...EFFECTIVELY SURGING
MOISTURE NORTH ON 40-50 KT LOW-LVL JET INTO THE REGION. AMSU SAT
BLENDED WATER PRECIP WATER INDICATES ~1.6 IN PWATS ACROSS SRN
LA/MS...EQUATING TO NEAR 230% OF NORMAL FOR THIS TIME OF YEAR. AS
SUCH...SHOWERS AND EMBEDDED TSRA WILL BE VERY EFFICIENT RAIN
PRODUCERS WITH PROLONGED DURATION POSSIBLE DUE TO TRAINING. AN
EXPANSION OF THE CURRENT FLOOD WATCH FARTHER TO THE SOUTH AND EAST
IS BEING EVALUATED. SEE HYDROLOGY SECTION BELOW FOR MORE DETAILS.
AS STRONG SFC CONVERGENCE COINCIDING WITH GREATEST MOISTURE
TRANSPORT AND VIGOROUS LIFT OCCURS THIS LATE AFTN/NGT...AN UPSWING
IN SHOWER AND TSTORM ACTIVITY LOOKS PROBABLE ACROSS E MS. WHILE NO
STRONG TO SEVERE STORMS ARE EXPECTED GIVEN LACK OF MUCAPE/
SBCAPE...RAINFALL RATES COULD BE ON THE ORDER OF 1-2 INCHES PER HOUR.
FROPA WILL DRIVE THROUGH REGION QUICKLY LATE TONIGHT INTO EARLY
TUESDAY MORNING...ENDING THE MODERATE TO HEAVY RAIN/TSRA ACTIVITY.
DRIZZLE/MIST WILL BE POSSIBLE THROUGH MID-TUESDAY MORNING BEFORE
GRADUAL CLEARING TAKES PLACE ACROSS S/W AREAS TUESDAY AFTERNOON.
FOR FORECAST MATTERS...BLENDED MAV/MET GUIDANCE FOR HIGHS TODAY AS
MAV WAS QUITE WARM IN SEVERAL AREAS AND MET SEEMINGLY NOT CAPTURING
THE MOISTURE RETURN IN OTHERS. FOR TUESDAY...DROPPED HIGHS A COUPLE
OF DEGREES GIVEN CAA...AND FORECAST MIXING HEIGHTS ~3 KFT EQUATING
TO LOWER TO MID 50S GIVEN TEMP PROFILE. /ALLEN/
.LONG TERM...WEDNESDAY THROUGH MONDAY...SURFACE HIGH PRESSURE
RIDGING WILL MOVE OVER THE AREA ON WEDNESDAY WITH LIGHT SOUTHERLY
FLOW DEVELOPING BY LATE AFTERNOON. THE WARMING TREND WILL BEGIN ON
WEDNESDAY WITH HIGH TEMPS WARMING A BIT INTO THE MID TO UPPER 50S FOR
THE MOST PART. SOUTHERLY FLOW WILL CONTINUE TO INCREASE ON THURSDAY
AS HIGH PRESSURE SHIFTS TO THE EAST AND TEMPS WARM INTO THE LOW 60S.
A NICE BEGINNING TO THE NEW YEARS WEEKEND LOOKS ON TRACK FOR FRIDAY
WITH CONTINUED WARM TEMPS AND PARTLY CLOUDY SKIES. THE GLOBAL MODELS
INDICATE THAT AN UPPER TROUGH WILL PASS TO THE NORTH DRAGGING A WEAK
COLD FRONT ACROSS THE AREA FRIDAY NIGHT...BUT THE NICE WEATHER WILL
CONTINUE ON NEW YEARS EVE WITH HIGHS CLIMBING WELL INTO THE 60S. THE
GFS AND ECMWF DIVERGE ON THERE SOLUTIONS AS WE PASS THROUGH THE NEW
YEAR ON SATURDAY NIGHT AND SUNDAY. BOTH OF THE MODELS INDICATE AN
INCREASE IN MOISTURE SATURDAY NIGHT INTO SUNDAY...WITH THE EURO
INDICATING A VIGOROUS UPPER TROUGH PASSING THROUGH THE AREA WITH
SEVERE POSSIBLE ON SUNDAY AND THE GFS FURTHER EAST WITH THE
DEEPENING TROUGH AND MAINLY INDICATING COLD FRONTAL PASSAGE AND JUST
SOME SHOWERS. THE GFS/ECMWF HAVE BEEN FLIP-FLOPPING WITH THIS
SCENARIO OVER THE PAST FEW DAYS SO WILL CONTINUE TO HOLD OFF ON
MENTIONING ANY SEVERE IN THE HWO. COOLER/DRIER CONDITIONS WILL
RETURN ON MONDAY EITHER WAY.
STUCK PRETTY CLOSE TO GUIDANCE TEMPS/POPS THROUGH THE PERIOD...BUT
DID WARM TEMPS SLIGHTLY ABOVE GUIDANCE ON FRIDAY/SATURDAY AND ALSO
BUMPED UP POPS TO INDICATE CHANCE THUNDERSTORMS ON SUNDAY./15/
&&
.AVIATION...MIXTURE OF VFR CONDITIONS ACROSS NRN TAF SITES
KGTR/KGLH/KGTR WITH IFR/LIFR CONDITIONS ACROSS CNTRL/SRN TAF
LOCATIONS. WIDESPREAD RA/TSRA IS ONGOING ACROSS CNTRL/SRN AREAS AT
THIS TIME AND WILL CONTINUE THROUGH REST OF DAY. NRN SITES WILL
RETURN TO MVFR TO IFR THIS MORNING AS RA/TSRA MOVES IN. GREATER
COVERAGE AND INTENSITY OF RA/TSRA THIS AFTERNOON WILL REDUCE VIS
DOWN TO 1-2 SM AT TIMES WITH CIGS 200-500 FT. SFC WINDS WILL VEER
FROM E TO S THROUGH THE DAY WITH QUICK SHIFT TO WEST FOLLOWING FROPA
06-12Z TUESDAY. WINDS SHEAR AND SPEEDS WITH HEIGHT WILL BE ELEVATED
THIS AFTN/NIGHT..ESPECIALLY ACROSS CNTRL/ERN TAF SITES...AMPLIFYING
TURBULENCE IN THE LOWEST 10 KFT. /ALLEN/
&&
.HYDROLOGY...SMALL CONVECTIVE COMPLEXES HAVE BEEN AFFECTING PARTS OF
S MS THIS MORNING...WITH A BAND OF 2 TO 4 INCHES OF RAINFALL HAVING
AFFECTED PARTS OF SE MS AND A FFW HAVING BEEN RECENTLY ISSUED. 88D
RADAR ESTIMATES SEEM PRETTY GOOD IN THOSE AREAS BASED ON GROUND
TRUTH REPORTS...AND ARE PROBABLY SEEING STORM TOTALS IN THE LAST 48
HOURS APPROACHING OR SLIGHTLY EXCEEDING 5 INCHES IN PARTS OF THESE
AREAS. UPPER LOW IS STILL WELL WEST OF THE AREA...AND LATEST
GUIDANCE SUGGESTS SEVERAL WAVES OF MODERATE TO HEAVY RAIN WITH
EMBEDDED CONVECTION AFFECTING MUCH OF THE REGION THROUGH
06Z...POSSIBLY LONGER IN EASTERN SECTIONS. GIVEN SEVERAL WAVES OF
HEAVY RAINFALL OVER THE LAST WEEK HAVING LOWERED ALREADY LIMITED
ABILITY OF WINTER GROUND TO HANDLE HEAVY RAIN...AND SEVERAL RIVERS
NOW APPROACHING OR FORECAST TO EXCEED FLOOD STAGE OVER PARTS OF THE
AREA...HAVE WENT AHEAD AND EXPANDED THE WATCH TO ENCOMPASS THE
ENTIRE REGION. LATEST NAM AND HRRR GUIDANCE SUGGESTS WIDESPREAD
ADDITIONAL 1 TO 2 INCH RAINFALL OVER THE ENTIRE AREA WITH EMBEDDED
BANDS OF 3 TO 5 INCHES WHERE TRAINING OF HEAVIER SHOWERS/STORMS
OCCURS. /08/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 55 43 54 34 / 100 100 3 0
MERIDIAN 57 47 55 31 / 100 100 8 0
VICKSBURG 55 41 54 32 / 100 94 3 0
HATTIESBURG 62 48 58 35 / 100 100 9 0
NATCHEZ 58 42 54 34 / 100 86 3 0
GREENVILLE 51 41 52 33 / 100 100 4 0
GREENWOOD 51 42 52 31 / 100 100 11 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLOOD WATCH THROUGH MIDNIGHT CST FOR ALL ZONES.
LA...FLOOD WATCH THROUGH MIDNIGHT CST FOR ALL ZONES.
AR...FLOOD WATCH THROUGH MIDNIGHT CST FOR ALL ZONES.
&&
$$
08/JA/15
AREA FORECAST DISCUSSION...UPDATED
NWS NEWPORT/MOREHEAD CITY NC
1010 AM EST MON DEC 26 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...THEN MOVE OFFSHORE
TONIGHT. A COMPLEX LOW PRESSURE SYSTEM WILL APPROACH THE AREA FROM
THE SOUTHWEST TUESDAY. THE LOW WILL PASS NORTH OF THE AREA TUESDAY
EVENING WHILE SWINGING A COLD FRONT THROUGH THE REGION TUESDAY
NIGHT. HIGH PRESSURE BUILDS OVER THE AREA WEDNESDAY THROUGH THE END
OF THE WEEK.
&&
.NEAR TERM /TODAY/...
AS OF 10 AM MON...RIDGING CONTINUES TO MOVE EAST ACROSS THE
REGION...ACTING TO VEER WINDS MORE NORTHERLY AS THE DAY
PROGRESSES. SITES ACROSS THE COASTAL PLAIN ARE CURRENTLY GUSTING
TO 15 KNOTS...WHICH IS EXPECTED TO CONTINUE THROUGHOUT THE DAY AS
STRONG COLD AIR ADVECTION IMPACTS THE REGION. KMHX/KGSO 12Z AND
FORECAST SOUNDINGS ILLUSTRATE VERY DRY AIRMASS ALOFT SO EXPECT
SUNNY SKIES TO PREVAIL TODAY...WITH A FEW HIGH CIRRUS POSSIBLE
ACROSS SOUTHERN PORTIONS. LOW LEVEL THICKNESSES REMAIN LOWER
TODAY...WITH 1000-850 MB THICKNESSES EXPECTED IN THE 1325-1330
METER RANGE. GIVEN WARMING TREND SLIGHTLY QUICKER THAN FORECAST
THIS MORNING...BUMPED TEMPS UP A FEW DEGREES MAINLY FOR INLAND
LOCATIONS.
&&
.SHORT TERM /TONIGHT/...
AS OF 300 AM MONDAY...WINDS WILL DIMINISH TONIGHT AS HIGH PRES MOVES
ACROSS. DON`T EXPECT MUCH IN THE WAY OF CLOUDS UNTIL LATE
SO WITH DRY AMS IN PLACE EXPECT GOOD RADIATIONAL COOLING WITH MIN
TEMPS FROM THE LOWER 30S INLAND TO AROUND 40 ON THE COAST.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...MODELS CONTINUE TO INDICATE MOST SIGNIFICANT
WEATHER DURING PERIOD WILL OCCUR TUE AND TUE NIGHT WITH COMPLEX UPR
AND SFC FEATURES AFFECTING AREA. SLOW MOVING UPR LOW NEAR NRN TEXAS
WILL BE PICKED UP BY DIVING NRN STREAM SHRT WV LATE TODAY AND
TONIGHT...WITH SRN STREAM SYSTEM BEING DAMPENED AS IT MERGES WITH
NRN STREAM OVER ERN U.S. LATE TUE. RESULTING SFC LOW TRACK W AND N
OF AREA AND UPR LVL DYNAMICS WILL PRODUCE MARGINAL SVR THREAT...LOW
CAPE BUT HIGH SHEAR...OVER ERN NC TUE AFTN AND EVENING. PER SPC DAY
2 OUTLOOK...MORE SIGNIFICANT THREAT WILL BE JUST S-SW OF AREA WITH
SLIGHTLY BETTER INSTABILITY. WILL CONTINUE MENTION IN HWO.
ADDITIONALLY...INCREASING WINDS MAY REACH ADVISORY CRITERIA ALONG
COASTAL SECTIONS...MAINLY OUTER BANKS...LATE TUE AFTN INTO EARLY
EVENING...AND WILL ADD MENTION OF THIS TO HWO AS WELL.
WITH SLIGHTLY BETTER MODEL AGREEMENT...RAISED POPS TO CATEGORICAL
LATE TUE AFTN AND ENDED POPS EARLIER INLAND TUE EVENING...WITH MINOR
ADJUSTMENTS TO TEMPS AND SKY COVER.
NO SIGNIFICANT CHANGES TO FCST FOR REST OF PERIOD. UPR FLOW WILL
BECOME MORE ZONAL...CUTTING OFF GULFMEX FEED...WITH MAINLY DRY NRN
STREAM SHRT WVS AFFECTING AREA THU AND AGAIN SAT. TEMPS WILL BE NEAR
SEASONAL WED-SUN.
&&
.AVIATION /15Z MONDAY THROUGH FRIDAY/...
SHORT TERM /THROUGH TONIGHT/...
AS OF 10 AM MON...HIGH PRESSURE WILL REMAIN IN CONTROL OF THE
SENSIBLE WEATHER THROUGH TODAY. NORTH-NORTHWEST WINDS WILL
CONTINUE AROUND 10 KNOTS WITH GUSTS NEAR 20 KNOTS...BECOMING NORTH
LATER THIS AFTERNOON. VERY DRY ATMOS IN PLACE SO DO NOT EXPECT
STRATOCUMULUS DEVELOPMENT THIS AFTERNOON. MID/HIGH CLOUDS DO NOT
BEGIN IMPACTING WESTERN TAF SITES/ISO/OAJ/PGV UNTIL NEAR SUNRISE
TUES MORNING. WINDS WILL CONTINUE VEERING OVERNIGHT...TO A MORE
SOUTHERLY RETURN FLOW BY SUNRISE. OVERALL DRY ATMOS AND WINDS
AROUND 4-6 KT OVERNIGHT SHOULD INHIBIT ANY FOG FORMATION. THUS
EXPECT VFR CONDITIONS OVERNIGHT AS WELL.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 315 AM MONDAY...SUB-VFR CONDITIONS ARE LIKELY TUESDAY INTO
TUESDAY EVENING IN WIDESPREAD SHOWERS/POSSIBLE STRONG THUNDERSTORMS
THAT ARE FORECAST TO OCCUR ALONG/AHEAD OF A STRONG COLD FRONT WHICH
WILL CROSS THE AREA TUESDAY NIGHT. PREVAILING VFR CONDITIONS ARE
THEN EXPECTED WEDNESDAY THROUGH FRIDAY AS A RELATIVELY DRY AIRMASS
EXTENDS OVER THE AREA.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1010 AM MON...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
SMALL CRAFT CONDITIONS ACROSS THE COASTAL WATERS. NORTHWEST TO
NORTH-NORTHWEST WINDS 20-25 KNOTS WITH GUSTS NEAR 30 KNOTS HAVE
BEEN OBSERVED ACROSS THE NORTHERN COASTAL WATERS...WITH 20 KNOTS
GUSTING TO 25 KNOTS ELSEWHERE. SEAS HAVE BUILT TO 5 TO 7 FT OFF
DUCK BUT EXPECT SEAS 6-8 FT FARTHER OFFSHORE. GIVEN CURRENT
SCENARIO AND LATEST 12Z NAM/14Z RUC GUIDANCE...HAVE EXTENDED THE
SCAS FOR THE SOUTHERN COASTAL WATERS UNTIL NOON...THE PAMLICO AND
ALBEMARLE SOUNDS UNTIL 2PM...AND THE CENTRAL WATERS REMAIN THROUGH
LATE THIS EVENING.
HIGH PRESSURE WILL CONTINUE TO MIGRATE EAST ACROSS THE WATERS
TODAY. THE RIDGE WILL CREST ACROSS THE WATERS OVERNIGHT...ALLOWING
WINDS TO VEER FURTHER...BECOMING EAST LATE AND DIMINISHING 10-15
KNOTS...THEN SOUTHEAST BY SUNRISE TUES. SEAS WILL DIMINISH BELOW
SCA LEVELS LATER THIS EVENING AS WELL.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 315 AM MONDAY...STRONG SCA TO MARGINAL GALE CONDITIONS ARE
LIKELY TUE AND TUE NIGHT AS DEVELOPING LOW PRES TRACKS W AND N OF
THE AREA...AND PUSHES A STRONG COLD FRONT THROUGH THE AREA FROM THE
WEST. MARINERS CAN EXPECT SOUTHERLY FLOW TO 30 KT OR HIGHER TUESDAY
SHIFTING TO WESTERLY THEN NORTHWESTERLY AT 30 KT OR HIGHER TUESDAY
NIGHT. IN THIS FLOW SEAS WILL LIKELY REACH OR EXCEED 10 FT FOR A
PERIOD TUESDAY INTO TUESDAY NIGHT. HIGHEST WINDS/SEAS ARE EXPECTED
OVER THE CENTRAL WATERS. WINDS WILL DIMINISH AND SEAS WILL SUBSIDE
LATE WEDNESDAY AS COLD ADVECTION WANES AND HIGH PRESSURE BUILDS OVER
THE WATERS. THE BROAD HIGH WILL CONTINUE OVER THE WATERS THURSDAY
THEN SHIFT OFFSHORE FRIDAY WITH WINDS 10-15 KT EXPECTED BOTH DAYS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR AMZ130-
135.
SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR AMZ150-
152-154.
SMALL CRAFT ADVISORY UNTIL NOON EST TODAY FOR AMZ156-158.
&&
$$
SYNOPSIS...DAG
NEAR TERM...DAG
SHORT TERM...JAC
LONG TERM...JBM
AVIATION...JBM/JME/DAG
MARINE...JBM/JME/DAG
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
631 AM EST MON DEC 26 2011
.SYNOPSIS...
A DEEPENING LOW PRESSURE SYSTEM IS EXPECTED TO TRACK NORTHEAST FROM
LOUISIANA TODAY AND REACH TENNESSEE AND KENTUCKY EARLY TUESDAY. HIGH
PRESSURE WILL BE BACK IN CONTROL FROM WEDNESDAY UNTIL THE WEEKEND
WHEN A COLD FRONT WILL APPROACH THE AREA FROM THE WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 610 AM...THE ONLY SITE STILL REPORTING DENSE FOG IS
GREENWOOD...AND CONDITIONS SHOULD IMPROVE THERE SHORTLY.
THEREFORE...THE DENSE FOG ADVISORY WILL NOT BE EXTENDED. TWEAKED
TEMPS AND DEWPOINTS AS DOWNSLOPE MIXING AND DRYING IS CAUSING A
VARIETY OF TEMPS AND DEWPOINTS ACROSS THE AREA.
PREVIOUS DISCUSSION...
DENSE FOG AND LOW CLOUDS CONTINUES ACROSS THE CENTRAL AND EASTERN
PARTS OF THE UPSTATE AND THE EXTREME SRN PIEDMONT OF NORTH CAROLINA.
DRY AIR WILL CONTINUE TO WORK SLOWLY TO THE SOUTH...GRADUALLY MIXING
OUT THE FOG AND LOW CLOUDS. THE RUC AND NAM CONDENSATION PRESSURE
DEFICITS IMPLY LOW CLOUDS AND FOG ARE LIKELY TO PERSIST THE LONGEST
ACROSS GREENVILLE...SPARTANBURG AND LAURENS COUNTIES IN A WEAK LLVL
CONVERGENCE AXIS. WE HAVE A DENSE FOG ADVISORY OVER PARTS OF THE
AREA THROUGH 6 AM. IT WILL LIKELY NEED TO BE CANCELLED EARLY OVER
THE WESTERN UPSTATE AND NE GA...BUT IT STILL LOOKS GOOD FARTHER TO
THE EAST.
A STRONG UPPER LOW OVER WEST TEXAS THIS MORNING WILL EJECT QUICKLY
ACROSS THE LOWER MISSISSIPPI VALLEY TONIGHT AND LIFT ACROSS THE SRN
APPALACHIANS ON TUE AS AN OPEN WAVE. SFC CYCLOGENESIS WILL OCCUR
THIS AFTERNOON OVER THE NRN GULF...WITH THE LOW MOVING ACROSS THE
SRN APPS ON TUE. THE LATEST NAM AND GFS MODEL DATA IS A LITTLE
COLDER ACROSS THE NC MTNS TONIGHT. THE NAM HAS A LARGE AREA OF
1305-1310 METER 1000-850 MB THICKNESSES ACROSS THE SW AND CENTRAL
MTNS AT 0900 UTC...WHICH RETREAT UP ACROSS THE NRN MTNS BY 12 UTC.
NAM MODEL SOUNDINGS AT FRANKLIN AND CASHIERS IMPLY A PERIOD OF SLEET
AND FREEZING RAIN STARTING AFTER MIDNIGHT...WITH PCPN CHANGING TO
ALL RAIN TOWARD MORNING. THE GFS IS A LITTLE WARMER AND LOOKS TO BE
MAINLY LIQUID...WITH JUST A LITTLE SLEET AND A FEW PATCHES OF
FREEZING RAIN AT ONSET. IT STILL APPEARS THAT THE BULK OF THE
COOLING WITH THIS EVENT WILL BE DRIVEN BY OROGRAPHIC ASCENT AS A 60+
KT LLVL WARM SECTOR JET CROSSES THE MTNS. THIS SHOULD CONFINE
WINTRY PCPN TO SOUTH AND EAST REACHES OF THE MTNS...WITH DOWNSLOPE
HELPING TO WARM THE BNDRY LAYER CLOSER TO THE TN LINE. ALSO...NONE
OF THE MODELS IMPLY THAT WINTRY WX WILL HOLD ON ONCE THE HEAVIER
RAIN STARTS OWING TO A STRONG WARM NOSE UP AROUND H8. STILL...A
PERIOD OF LIGHT FREEZING RAIN AND SOME SLEET LOOKS LIKELY ACROSS
THE SW MTNS...AND ALSO ACROSS THE EASTERN ESCARPMENT OF THE BLUE
RIDGE UP IN THE NRN MTNS. AT THE MOST...THIS SHOULD BE A LOW END
ADVISORY LEVEL EVENT WITH ANY GLAZE CONFINED MAINLY TO ELEVATED
SFCS...AND IT WON/T AFFECT THE MTNS UNTIL WELL AFTER DARK TONIGHT.
THEREFORE...I/M GOING TO HOLD OFF ON ANY ADVISORIES WITH THIS
PACKAGE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 315 AM MONDAY...THE MODELS ARE IN VERY GOOD AGREEMENT ON THE
POSITION OF THE UPPER SHORTWAVE AND SFC LOW PRESSURE AT 12Z TUESDAY.
AN IN SITU WEDGE WILL STILL BE IN PLACE ACRS THE CWFA...WITH SELY
850 MB WINDS OF 50-65 KTS ALOFT. VERY STRONG LLVL WAA AND MECHANICAL
LIFT WITH DEEP MOISTURE WILL BE AIDED BY DECENT QG FORCING AND UPPER
DIVERGENCE. SO A NEAR 100% POP TUESDAY MORNING SEEMS APPROPRIATE.
THERE ARE SOME DIFFERENCES AMONGST THE THERMAL PROFILES/SFC TEMPS
INVOF THE NC MTNS...HOWEVER...AS DYNAMICAL COOLING MAY LOCK IN
SUB-FREEZING TEMPS INVOF THE EAST-FACING SLOPES OF THE NRN MTNS/BLUE
RIDGE ESCARPMENT PAST DAYBREAK TUESDAY MORNING...WITH SOME
ADDITIONAL ICING POSSIBLE. ALL GUIDANCE HAS TEMPS WARMING ABOVE
FREEZING BY 15Z TUE...SO IT STILL LOOKS LIKE ANY TRAVEL PROBLEMS DUE
TO ICE SHUD BE OVER BY MIDDAY.
MIDDAY TUESDAY...THE LOW PRESSURE SYSTEM WILL QUICKLY LIFT
NORTHEASTWARD...WITH A PRIMARY LOW TRACKING ACRS THE TN/OH
VLYS...AND A TRIPLE POINT LOW TRACKING FROM CENTRAL GA TO CENTRAL NC
BY LATE AFTN. THE NAM/GFS/ECWMF ARE IN GOOD AGREEMENT ON THE GSP/CAE
CWFA BORDER AS AN APPROXIMATE TRACK OF THE TRIPLE POINT. SO INSTBY
LOOKS TO STAY SOUTH OF THE FA. THAT IS GOOD...BECAUSE HELICITY
VALUES WILL BE THRU THE ROOF...AND VERY LITTLE INSTBY WOULD BE
SUFFICIENT FOR A SMALL TORNADO/WIND THREAT. THE COLD/OCCLUDED FRONT
WILL CROSS FROM SW TO NE DURING THE AFTN HOURS...QUICKLY TAPERING
OFF POPS (EXCEPT FOR UPSLOPE ALONG TN/NC BORDER). STORM TOTAL QPF
LOOKS TO BE A SOLID 1-1.5" CWFA-WIDE...WITH 2-3" ALONG THE BLUE
RIDGE ESCARPMENT FROM HENDERSON COUNTY WEST. THERE COULD BE A FEW
HYDRO CONCERNS IN THOSE AREAS...BUT NOT WIDESPREAD ENUF TO WARRANT
ANY FLOOD WATCHES ATTM. WITH CLOUDS AND PRECIP...TEMPS WILL BE HELD
DOWN TO MAINLY MID-UPR 40S...EXCEPT ALONG SOUTHEAST EDGE NEAR THE
TMB/WEDGE BNDRY WHERE THEY WILL BE IN THE MID 50S OR HIGHER.
TUESDAY NIGHT...THERE WILL BE STRONG LLVL CAA ACRS THE FA IN THE
WAKE OF THE DEPARTING LOW...WITH GOOD NW FLOW UPSLOPE FORCING ALONG
THE TN/NC BORDER. BOTH THE NAM AND GFS IMPLY AT LEAST SCATTERED
SHOWER ACTIVITY...AND SNOW LEVELS SHUD FALL QUICKLY DURING THE
EVENING HOURS. SOME LOCATIONS MAY GET A QUICK INCH OR TWO
(ESPECIALLY ABOVE 3500 FT). THE SHOWER ACTIVITY LOOKS TO QUICKLY
TAPER OFF BY LATE WEDNESDAY MORNING. TEMPS ACRS THE ENTIRE AREA WILL
BE NEAR NORMAL.
WEDNESDAY AND WEDNESDAY NIGHT...GENERAL UPPER LEVEL TROFINESS
LINGERS...AS WEAK SFC HIGH PRESSURE BUILDS IN ACRS THE AREA. HIGH
TEMPS WILL BE AT OR A CATEGORY BELOW NORMAL AND OVERNIGHT LOWS
AROUND NORMAL UNDER GENERALLY CLEAR SKIES.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AT 220 AM EST MONDAY...ON THURSDAY THE MEDIUM RANGE MODELS SHOW
SURFACE HIGH PRESSURE CENTERED OVER THE GULF COAST AT THE FLORIDA
PANHANDLE WHILE CUTTING OFF ANY MOISTURE FLOW TO OUR REGION. FAIRLY
VIGOROUS VORT MAXES CROSSING THE AREA BUT NO MOISTURE TO WORK WITH.
ON FRIDAY...THE SURFACE HIGH SHIFTS EAST TO FLORIDA AND FARTHER EAST
AND SOME MOISTURE FLOW STARTS FROM THE WESTERN GULF AS A SHORTWAVE
DROPS DOWN FROM THE NORTHERN MISS VALLEY AND OHIO VALLEY. THIS
SHORTWAVE REACHES THE APPALACHIANS FRIDAY NIGHT AND SOME NORTHWEST
FLOW MOISTURE ALIGNS ALONG THE UPSLOPE REGION ALONG THE TENNESSEE
AND NORTH CAROLINA BORDER. THE FAST MOVING SHORTWAVE HAS AN AXIS
NEAR THE WV / VA BORDER BY 12Z SATURDAY ON BOTH THE GFS AND ECMWF.
IF THERE IS ANY SNOW SHOWERS FOR THE NC MOUNTAINS NEAR THE TN
BORDER...THIS WILL BE BRIEF AND MAINLY IN THE WEE HOURS OF SATURDAY
ACCORDING TO THE CURRENT TIMING OF THE MODELS. THE LATEST ECMWF
JUST CAME IN AND MUCH DRIER WITH ONLY A HINT OF ANY PRECIP FAR
NORTHERN MOUNTAINS AROUND 12Z SATURDAY. THE ENERGY WITH THE
SHORTWAVE IS FARTHER NORTH WITH THIS EC RUN. AT THIS POINT...NOT
FEELING CONFIDENT AND LEAVING NO MORE THAN 14 POP...JUST BELOW
SLIGHT POPS.
WEAK HIGH PRESSURE CENTERED OVER OUR REGION SATURDAY NIGHT. RETURN
FLOW BEGINS OVER THE LOWER MISS VALLEY SATURDAY NIGHT AHEAD OF THE
NEXT SHORTWAVE. THIS NEXT SHORTWAVE IS QUITE DIFFERENT ON THE GFS
COMPARED TO THE ECMWF. THE GFS HAS A STRONG SHORTWAVE CROSSING
GREAT LAKES AND OHIO VALLEY SUNDAY AND LOWERING THICKNESS VALUES
SUNDAY NIGHT FOR OUR AREA...ESPECIALLY IN NC. VERY LITTLE MOISTURE
ON GFS. HOWEVER...THE ECMWF HAS A DEEP CUT OFF UPPER LOW CROSSING
MISSOURI LATE SUNDAY NIGHT WITH ASSOCIATED COLD FRONT REACHING OUR
AREA NEAR 12Z MONDAY WITH GOOD SOUTHERN FLOW FROM THE GULF. THIS
LATEST EC IS QUITE DIFFERENT FROM THE PREVIOUS RUN AND THE SUNDAY
NIGHT PERIOD IS THE EXTRA PERIOD THAT DOES NOT COUNT IN THE CURRENT
SEVEN DAY FORECAST. THUS WE WILL SEE AS THE TIME GETS CLOSER TO
THAT POINT.
TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL WITH SLIGHT FALLS
WITH PASSING SHORTWAVES.
&&
.AVIATION /12Z MONDAY THROUGH FRIDAY/...
AT KCLT...HIGH PRESSURE WILL BUILD INTO THE REGION TODAY. WINDS WILL
START THE MORNING OUT OF THE NORTH...VEERING AROUND TO NORTHEAST IN
THE AFTN. A FEW GUSTS TO 18 TO 20 KTS ARE EXPECTED THIS MORNING.
WINDS WILL BECOME LIGHT FOR A TIME THIS EVENING...BEFORE TURNING OUT
OF THE ESE OVERNIGHT AS THE HIGH MOVES OFF THE COAST AND LOW
PRESSURE APPROACHES FROM THE SOUTH. THE RAPIDLY MOVING STORM SYSTEM
WILL BRING RAIN AND LOWERING CIGS INTO THE AIRFIELD AT THE VERY END
OF THE VALID PERIOD OF THE TAF.
AND ELSEWHERE...THE PROGRESSION OF THE RIDGE AND WIND SHIFTS WILL BE
SIMILAR TO THOSE MENTIONED FOR KCLT. TOWARD THE END OF THE
PERIOD...RAIN AND LOW CIGS WILL RAPIDLY SPREAD INTO THE REGION FROM
THE SOUTH. THE GUIDANCE DROPS CIGS INTO THE LIFR RANGE VERY QUICKLY
AT THE END OF THE TAF PERIOD. WITH THE LLVL DRY AIR IN PLACE THIS
MAY BE OVERDONE. LOW LEVEL WIND SHEAR IS LIKELY TO DEVELOP LATER
TONIGHT AS A ESE ORIENTED LLVL JET MOVES ACROSS THE REGION.
OUTLOOK...LOW PRES WILL MOVE N FROM THE W GULF MON NIGHT AND INTO
THE FORECAST AREA TUE...BRINGING WIDESPREAD PRECIPITATION AND IFR OR
LOWER CIG RESRICTIONS ON TUE. DRYING IS EXPECTED TUE NIGHT...WITH
LINGERING NW FLOW MOISTURE NEAR KAVL. CONDITIONS DRY OUT ACROSS THE
AREA MID TO LATE WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY
SHORT TERM...ARK
LONG TERM...DEO
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS GREENVILLE-SPARTANBURG SC
612 AM EST MON DEC 26 2011
.SYNOPSIS...
A DEEPENING LOW PRESSURE SYSTEM IS EXPECTED TO TRACK NORTHEAST FROM
LOUISIANA TODAY AND REACH TENNESSEE AND KENTUCKY EARLY TUESDAY. HIGH
PRESSURE WILL BE BACK IN CONTROL FROM WEDNESDAY UNTIL THE WEEKEND
WHEN A COLD FRONT WILL APPROACH THE AREA FROM THE WEST.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 610 AM...THE ONLY SITE STILL REPORTING DENSE FOG IS
GREENWOOD...AND CONDITIONS SHOULD IMPROVE THERE SHORTLY.
THEREFORE...THE DENSE FOG ADVISORY WILL NOT BE EXTENDED. TWEAKED
TEMPS AND DEWPOINTS AS DOWNSLOPE MIXING AND DRYING IS CAUSING A
VARIETY OF TEMPS AND DEWPOINTS ACROSS THE AREA.
PREVIOUS DISCUSSION...
DENSE FOG AND LOW CLOUDS CONTINUES ACROSS THE CENTRAL AND EASTERN
PARTS OF THE UPSTATE AND THE EXTREME SRN PIEDMONT OF NORTH CAROLINA.
DRY AIR WILL CONTINUE TO WORK SLOWLY TO THE SOUTH...GRADUALLY MIXING
OUT THE FOG AND LOW CLOUDS. THE RUC AND NAM CONDENSATION PRESSURE
DEFICITS IMPLY LOW CLOUDS AND FOG ARE LIKELY TO PERSIST THE LONGEST
ACROSS GREENVILLE...SPARTANBURG AND LAURENS COUNTIES IN A WEAK LLVL
CONVERGENCE AXIS. WE HAVE A DENSE FOG ADVISORY OVER PARTS OF THE
AREA THROUGH 6 AM. IT WILL LIKELY NEED TO BE CANCELLED EARLY OVER
THE WESTERN UPSTATE AND NE GA...BUT IT STILL LOOKS GOOD FARTHER TO
THE EAST.
A STRONG UPPER LOW OVER WEST TEXAS THIS MORNING WILL EJECT QUICKLY
ACROSS THE LOWER MISSISSIPPI VALLEY TONIGHT AND LIFT ACROSS THE SRN
APPALACHIANS ON TUE AS AN OPEN WAVE. SFC CYCLOGENESIS WILL OCCUR
THIS AFTERNOON OVER THE NRN GULF...WITH THE LOW MOVING ACROSS THE
SRN APPS ON TUE. THE LATEST NAM AND GFS MODEL DATA IS A LITTLE
COLDER ACROSS THE NC MTNS TONIGHT. THE NAM HAS A LARGE AREA OF
1305-1310 METER 1000-850 MB THICKNESSES ACROSS THE SW AND CENTRAL
MTNS AT 0900 UTC...WHICH RETREAT UP ACROSS THE NRN MTNS BY 12 UTC.
NAM MODEL SOUNDINGS AT FRANKLIN AND CASHIERS IMPLY A PERIOD OF SLEET
AND FREEZING RAIN STARTING AFTER MIDNIGHT...WITH PCPN CHANGING TO
ALL RAIN TOWARD MORNING. THE GFS IS A LITTLE WARMER AND LOOKS TO BE
MAINLY LIQUID...WITH JUST A LITTLE SLEET AND A FEW PATCHES OF
FREEZING RAIN AT ONSET. IT STILL APPEARS THAT THE BULK OF THE
COOLING WITH THIS EVENT WILL BE DRIVEN BY OROGRAPHIC ASCENT AS A 60+
KT LLVL WARM SECTOR JET CROSSES THE MTNS. THIS SHOULD CONFINE
WINTRY PCPN TO SOUTH AND EAST REACHES OF THE MTNS...WITH DOWNSLOPE
HELPING TO WARM THE BNDRY LAYER CLOSER TO THE TN LINE. ALSO...NONE
OF THE MODELS IMPLY THAT WINTRY WX WILL HOLD ON ONCE THE HEAVIER
RAIN STARTS OWING TO A STRONG WARM NOSE UP AROUND H8. STILL...A
PERIOD OF LIGHT FREEZING RAIN AND SOME SLEET LOOKS LIKELY ACROSS
THE SW MTNS...AND ALSO ACROSS THE EASTERN ESCARPMENT OF THE BLUE
RIDGE UP IN THE NRN MTNS. AT THE MOST...THIS SHOULD BE A LOW END
ADVISORY LEVEL EVENT WITH ANY GLAZE CONFINED MAINLY TO ELEVATED
SFCS...AND IT WON/T AFFECT THE MTNS UNTIL WELL AFTER DARK TONIGHT.
THEREFORE...I/M GOING TO HOLD OFF ON ANY ADVISORIES WITH THIS
PACKAGE.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY NIGHT/...
AS OF 315 AM MONDAY...THE MODELS ARE IN VERY GOOD AGREEMENT ON THE
POSITION OF THE UPPER SHORTWAVE AND SFC LOW PRESSURE AT 12Z TUESDAY.
AN IN SITU WEDGE WILL STILL BE IN PLACE ACRS THE CWFA...WITH SELY
850 MB WINDS OF 50-65 KTS ALOFT. VERY STRONG LLVL WAA AND MECHANICAL
LIFT WITH DEEP MOISTURE WILL BE AIDED BY DECENT QG FORCING AND UPPER
DIVERGENCE. SO A NEAR 100% POP TUESDAY MORNING SEEMS APPROPRIATE.
THERE ARE SOME DIFFERENCES AMONGST THE THERMAL PROFILES/SFC TEMPS
INVOF THE NC MTNS...HOWEVER...AS DYNAMICAL COOLING MAY LOCK IN
SUB-FREEZING TEMPS INVOF THE EAST-FACING SLOPES OF THE NRN MTNS/BLUE
RIDGE ESCARPMENT PAST DAYBREAK TUESDAY MORNING...WITH SOME
ADDITIONAL ICING POSSIBLE. ALL GUIDANCE HAS TEMPS WARMING ABOVE
FREEZING BY 15Z TUE...SO IT STILL LOOKS LIKE ANY TRAVEL PROBLEMS DUE
TO ICE SHUD BE OVER BY MIDDAY.
MIDDAY TUESDAY...THE LOW PRESSURE SYSTEM WILL QUICKLY LIFT
NORTHEASTWARD...WITH A PRIMARY LOW TRACKING ACRS THE TN/OH
VLYS...AND A TRIPLE POINT LOW TRACKING FROM CENTRAL GA TO CENTRAL NC
BY LATE AFTN. THE NAM/GFS/ECWMF ARE IN GOOD AGREEMENT ON THE GSP/CAE
CWFA BORDER AS AN APPROXIMATE TRACK OF THE TRIPLE POINT. SO INSTBY
LOOKS TO STAY SOUTH OF THE FA. THAT IS GOOD...BECAUSE HELICITY
VALUES WILL BE THRU THE ROOF...AND VERY LITTLE INSTBY WOULD BE
SUFFICIENT FOR A SMALL TORNADO/WIND THREAT. THE COLD/OCCLUDED FRONT
WILL CROSS FROM SW TO NE DURING THE AFTN HOURS...QUICKLY TAPERING
OFF POPS (EXCEPT FOR UPSLOPE ALONG TN/NC BORDER). STORM TOTAL QPF
LOOKS TO BE A SOLID 1-1.5" CWFA-WIDE...WITH 2-3" ALONG THE BLUE
RIDGE ESCARPMENT FROM HENDERSON COUNTY WEST. THERE COULD BE A FEW
HYDRO CONCERNS IN THOSE AREAS...BUT NOT WIDESPREAD ENUF TO WARRANT
ANY FLOOD WATCHES ATTM. WITH CLOUDS AND PRECIP...TEMPS WILL BE HELD
DOWN TO MAINLY MID-UPR 40S...EXCEPT ALONG SOUTHEAST EDGE NEAR THE
TMB/WEDGE BNDRY WHERE THEY WILL BE IN THE MID 50S OR HIGHER.
TUESDAY NIGHT...THERE WILL BE STRONG LLVL CAA ACRS THE FA IN THE
WAKE OF THE DEPARTING LOW...WITH GOOD NW FLOW UPSLOPE FORCING ALONG
THE TN/NC BORDER. BOTH THE NAM AND GFS IMPLY AT LEAST SCATTERED
SHOWER ACTIVITY...AND SNOW LEVELS SHUD FALL QUICKLY DURING THE
EVENING HOURS. SOME LOCATIONS MAY GET A QUICK INCH OR TWO
(ESPECIALLY ABOVE 3500 FT). THE SHOWER ACTIVITY LOOKS TO QUICKLY
TAPER OFF BY LATE WEDNESDAY MORNING. TEMPS ACRS THE ENTIRE AREA WILL
BE NEAR NORMAL.
WEDNESDAY AND WEDNESDAY NIGHT...GENERAL UPPER LEVEL TROFINESS
LINGERS...AS WEAK SFC HIGH PRESSURE BUILDS IN ACRS THE AREA. HIGH
TEMPS WILL BE AT OR A CATEGORY BELOW NORMAL AND OVERNIGHT LOWS
AROUND NORMAL UNDER GENERALLY CLEAR SKIES.
&&
.LONG TERM /THURSDAY THROUGH SUNDAY/...
AT 220 AM EST MONDAY...ON THURSDAY THE MEDIUM RANGE MODELS SHOW
SURFACE HIGH PRESSURE CENTERED OVER THE GULF COAST AT THE FLORIDA
PANHANDLE WHILE CUTTING OFF ANY MOISTURE FLOW TO OUR REGION. FAIRLY
VIGOROUS VORT MAXES CROSSING THE AREA BUT NO MOISTURE TO WORK WITH.
ON FRIDAY...THE SURFACE HIGH SHIFTS EAST TO FLORIDA AND FARTHER EAST
AND SOME MOISTURE FLOW STARTS FROM THE WESTERN GULF AS A SHORTWAVE
DROPS DOWN FROM THE NORTHERN MISS VALLEY AND OHIO VALLEY. THIS
SHORTWAVE REACHES THE APPALACHIANS FRIDAY NIGHT AND SOME NORTHWEST
FLOW MOISTURE ALIGNS ALONG THE UPSLOPE REGION ALONG THE TENNESSEE
AND NORTH CAROLINA BORDER. THE FAST MOVING SHORTWAVE HAS AN AXIS
NEAR THE WV / VA BORDER BY 12Z SATURDAY ON BOTH THE GFS AND ECMWF.
IF THERE IS ANY SNOW SHOWERS FOR THE NC MOUNTAINS NEAR THE TN
BORDER...THIS WILL BE BRIEF AND MAINLY IN THE WEE HOURS OF SATURDAY
ACCORDING TO THE CURRENT TIMING OF THE MODELS. THE LATEST ECMWF
JUST CAME IN AND MUCH DRIER WITH ONLY A HINT OF ANY PRECIP FAR
NORTHERN MOUNTAINS AROUND 12Z SATURDAY. THE ENERGY WITH THE
SHORTWAVE IS FARTHER NORTH WITH THIS EC RUN. AT THIS POINT...NOT
FEELING CONFIDENT AND LEAVING NO MORE THAN 14 POP...JUST BELOW
SLIGHT POPS.
WEAK HIGH PRESSURE CENTERED OVER OUR REGION SATURDAY NIGHT. RETURN
FLOW BEGINS OVER THE LOWER MISS VALLEY SATURDAY NIGHT AHEAD OF THE
NEXT SHORTWAVE. THIS NEXT SHORTWAVE IS QUITE DIFFERENT ON THE GFS
COMPARED TO THE ECMWF. THE GFS HAS A STRONG SHORTWAVE CROSSING
GREAT LAKES AND OHIO VALLEY SUNDAY AND LOWERING THICKNESS VALUES
SUNDAY NIGHT FOR OUR AREA...ESPECIALLY IN NC. VERY LITTLE MOISTURE
ON GFS. HOWEVER...THE ECMWF HAS A DEEP CUT OFF UPPER LOW CROSSING
MISSOURI LATE SUNDAY NIGHT WITH ASSOCIATED COLD FRONT REACHING OUR
AREA NEAR 12Z MONDAY WITH GOOD SOUTHERN FLOW FROM THE GULF. THIS
LATEST EC IS QUITE DIFFERENT FROM THE PREVIOUS RUN AND THE SUNDAY
NIGHT PERIOD IS THE EXTRA PERIOD THAT DOES NOT COUNT IN THE CURRENT
SEVEN DAY FORECAST. THUS WE WILL SEE AS THE TIME GETS CLOSER TO
THAT POINT.
TEMPERATURES WILL BE A FEW DEGREES ABOVE NORMAL WITH SLIGHT FALLS
WITH PASSING SHORTWAVES.
&&
.AVIATION /11Z MONDAY THROUGH FRIDAY/...
AT KCLT...A SHARP DEWPOINT GRADIENT WAS LOCATED JUST TO THE
NORTHWEST OF THE AIRFIELD AT TAF ISSUANCE TIME. SOUTH OF THE BNDRY
WIDESPREAD DENSE FOG AND/OR VLIFR STRATUS HAS DEVELOPED. DRY AIR
WILL VERY SLOWLY PUSH TO THE SOUTH OVERNIGHT...BUT IT WILL BE A
COUPLE HOURS YET UNTIL THE DRY AIR WORKS IT/S WAY ACROSS THE
AIRFIELD WITH A WIND SHIFT TO THE NORTHWEST AND IMPROVING
CONDITIONS. SOME GUIDANCE TAKES EVEN LONGER TO BRING THE BNDRY
THROUGH...BUT BASED ON THE GUSTY WINDS AT KHKY AND 25 DEG DEWPOINT
AT KIPJ...I THINK THAT CONDITIONS WILL IMPROVE AT KCLT AFTER 0800
UTC.
AND ELSEWHERE...DRY AIR AND A WEAK COLD FRONT HAVE PUSHED THROUGH
KAVL AND KHKY WHICH WILL SEE NORTHWEST WINDS AND VFR CONDITIONS THE
REST OF THE NIGHT. OVER THE UPSTATE THE BNDRY HAS ONLY JUST MOVED
OFF THE ESCAPEMENT...AND IT WILL MOVE VERY SLOWLY...IF AT
ALL...OVER THE NEXT SEVERAL HOURS. DENSE FOG AND VLIFR CIGS HAVE
DEVELOPED IN THE MOIST AIR AHEAD OF THE BNDRY...AND THESE CONDITIONS
ARE EXPECTED TO PERSIST FOR THE NEXT 3 HRS OR SO AT THE THREE
UPSTATE AIRFIELDS. EVENTUALLY THE STRATUS AND FOG WILL BE PUSHED
SOUTH OF I-85...BUT A CONVERGENCE AXIS MAY HOLD IN LOW CIGS THROUGH
SUNRISE...ESPECIALLY AT KGMU AND KAND...WHICH IS WHAT I/VE DONE IN
THE TAFS. CONDITIONS THE REST OF THE DAY WILL BE GOOD WITH VFR
CONDITIONS AND LIGHT AND VARIABLE WINDS UNDER A RIDGE OF HIGH
PRESSURE.
OUTLOOK...LOW PRES WILL MOVE N FROM THE W GULF MON NIGHT AND INTO
THE FORECAST AREA TUE...BRINGING WIDESPREAD PRECIPITATION AND LOW
RESTRICTIONS. DRYING IS EXPECTED TUE NIGHT...WITH LINGERING NW FLOW
MOISTURE NEAR KAVL. CONDITIONS DRY OUT ACROSS THE AREA MID TO LATE
WEEK.
AN EXPERIMENTAL AVIATION FORECAST CONSISTENCY TABLE SHOWING THE
PERCENTAGE OF GUIDANCE MEMBERS AGREEING WITH THE SCHEDULED ISSUANCE
CATEGORY IS AVAILABLE AT FOLLOWING LINK (USE LOWER CASE)...
WWW.WEATHER.GOV/GSP/AVIATION/TABLES.HTM
&&
.GSP WATCHES/WARNINGS/ADVISORIES...
GA...NONE.
NC...NONE.
SC...NONE.
&&
$$
SYNOPSIS...DEO
NEAR TERM...MCAVOY
SHORT TERM...ARK
LONG TERM...DEO
AVIATION...MCAVOY
AREA FORECAST DISCUSSION
NWS DODGE CITY KS
332 PM CST MON DEC 26 2011
.DISCUSSION...
DAYS 1-2...
THE MAIN FORECAST FOCUS WILL BE ON TEMPERATURES DURING THE PERIOD.
WV IMAGERY AND 12Z UPPER AIR ANALYSIS INDICATE AN UPPER LEVEL
TROUGH OF LOW PRESSURE EDGING SLOWLY EAST ACROSS THE SOUTH PLAINS
OF WESTERN OKLAHOMA AND NORTH TEXAS. NEAR THE SURFACE, A TROUGH OF
LOW PRESSURE EXTENDS FROM THE DAKOTAS SOUTHWARD ACROSS WESTERN
NEBRASKA INTO EXTREME EASTERN COLORADO.
SHORT RANGE MODELS INDICATE THE UPPER LEVEL TROUGH MOVING FURTHER
EAST INTO THE LOWER MISSISSIPPI RIVER VALLEY TONIGHT THEN LIFTING
NORTHEAST ALONG THE EASTERN SEABOARD THROUGH TUESDAY NIGHT. THIS
WILL GIVE WAY TO A NORTHWESTERLY FLOW ALOFT ACROSS THE WESTERN
HIGH PLAINS THROUGH THE END OF THE PERIOD WEDNESDAY. ONE MINOR
SHORTWAVE WILL TRAVEL SOUTHEAST ACROSS THE WESTERN HIGH PLAINS
TUESDAY NIGHT BUT NO PRECIP IS EXPECTED ACROSS WESTERN KANSAS WITH
VERY LITTLE MOISTURE AVAILABLE FOR IT TO WORK WITH. TEMPERATURES
ARE EXPECTED TO BE NEAR NORMAL DURING THE PERIOD. FOR TONIGHT, AN
UPPER LEVEL SHORTWAVE TRANSITIONING EAST ACROSS THE NORTHERN
PLAINS WILL HELP PUSH A COLD FRONT SOUTHEAST ACROSS WESTERN KANSAS
THIS EVENING TURNING WINDS NORTHWESTERLY ACROSS WESTERN KANSAS AND
BRINGING SLIGHTLY COOLER AIR INTO THE REGION. ALTHOUGH, DOWNSLOPING
MAY KEEP TEMPERATURES FROM VARYING TOO MUCH TONIGHT IN COMPARISON
TO THIS MORNING, BUT SITES DOWNWIND OF THE LINGERING SNOWPACK WILL
LIKELY SEE LOW TEMPERATURES DROP SOMEWHAT. LOOK FOR LOWS DOWN
INTO THE TEENS(C) AND 20S(C) ACROSS MUCH OF SOUTHWEST KANSAS WITH
THE COOLEST TEMPERATURES ASSOCIATED WITH THE SNOWPACK.
FOR TUESDAY, LEE SIDE TROUGHING WILL QUICKLY REDEVELOP ACROSS
EASTERN COLORADO HELPING TO TURN SURFACE WINDS BACK TO THE WEST AND
SOUTHWEST BY EARLY TUESDAY AFTERNOON. THE NAM, GFS, AND UKMET SHOW
H85 TEMPERATURES RANGING FROM AROUND 0C ACROSS CENTRAL KANSAS TO
NEAR 2C IN OUR FAR SOUTHWEST. EXPECT HIGHS IN THE MID TO UPPER
40S(F) IN SOUTH CENTRAL KANSAS WITH HIGHS STRUGGLING TO REACH NEAR
40F IN WEST CENTRAL KANSAS WHERE SNOWPACK WILL REMAIN PRESENT.
SIMILAR TEMPERATURES ARE EXPECTED OVER THE COURSE OF TUESDAY NIGHT
AND WEDNESDAY WITH A GENERAL DOWNSLOPING REGIME REMAINING IN
PLACE ACROSS WESTERN KANSAS THROUGH AT LEAST MID WEEK.
DAYS 3-7...
LONG RANGE MODELS LOOK COMPARABLE INTO FRIDAY WITH DRY NORTHWEST
FLOW ALOFT AND MILD 850 MB TEMPS AROUND 10 TO 14C. AFTER THAT THE
ECMWF PUSHES A STRONG UPPER LEVEL TROUGH ACROSS THE NORTHERN AND
CENTRAL CONUS FOR NEXT WEEKEND WHILE OTHER MODELS HAVE MORE RIDGING
AND LESS COOLING. THE GFS AND EC AGREE WITH A COLD FRONT ON SUNDAY
BUT THE EC HAS A MUCH COLDER AIRMASS WITH 850 TEMPS FALLING INTO THE
-3C WITH THE GFS AT 4C. THEN BY MONDAY IF THE EC WORKS OUT IT SHOWS
SOME ARCTIC AIR INVADING ON MONDAY. THE NEW 144 HR RUN OF THE UKMET
NOW LOOKS EVEN COLDER AND FASTER FOR THE COLDER AIRMASS THAN EVEN
THE ECMWF. FOR NOW WITH THE BLENDED SOLUTIONS HOLDING ON TO MORE OF
THE WARMER GFS RUNS WILL CONTINUE WITH COOLER TEMPS FOR THE WEEKEND
WITH THE WEAKER COLD FRONT, BUT NOT AS COLD AS THE UK/ECMWF AT THIS
TIME.
AS FOR TEMPS GO LOOK FOR LOWS IN THE UPPER 20S THURSDAY MORNING
WARMING INTO THE LOWER 30S INTO THE WEEKEND. HIGHS WILL WARM INTO
THE LOW TO MID 50S INTO FRIDAY WITH A COOLING TREND ON THE WEEKEND
INTO THE 40S. THE COLD GROUND AND SNOW PACKED AREAS WILL BE FADING
RAPIDLY AWAY BY THURSDAY WITH HIGHS ONLY SLIGHTLY COOLER IN THE ANY
REMAINING SNOWPACK.
&&
.AVIATION...
FOR THE 18Z TAF ISSUANCE...
A NORTHERN BRANCH SHORTWAVE TROUGH WILL MOVE ACROSS THE NORTHERN
HIGH PLAINS AND INTO THE UPPER MIDWEST BY 12Z TUES. THIS SYSTEM WILL
PUSH A DRY COLD FRONT ACROSS WESTERN KANSAS THIS EVENING. WINDS WILL
SHIFT FROM THE WEST AND SOUTHWEST TO THE NORTHWEST AT 10 TO 15 KTS
BY 00Z TO 03Z AT THE TAF SITES. THE 18Z RUN OF THE HRRR AND THE NEW
18Z NAM AND RUC HAVE THE FRONT A BIT DELAYED THAN THE EARLIER NAM
RUN. VFR CONDITIONS ARE EXPECTED WITH ONLY SOME SCT HIGH LEVEL
CIRRUS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 17 40 20 47 / 0 0 0 0
GCK 13 37 18 43 / 0 0 0 0
EHA 20 40 22 47 / 0 0 0 0
LBL 13 42 18 48 / 0 0 0 0
HYS 18 38 20 45 / 0 0 0 0
P28 23 47 25 52 / 0 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN32/06/06
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1230 PM MST MON DEC 26 2011
.UPDATE...
1225 PM MST MON DEC 26 2011
SFC TROUGH MOVING ACROSS THE CWA HAS ALLOWED TEMPS TO WARM MORE
THAN PREVIOUSLY THOUGHT. HAVE UPDATED THE FCST TO REFLECT THE WARMING
AND BUMPED UP THE SFC WINDS IN ORDER TO BETTER AGREE WITH OBS.
05
&&
.SYNOPSIS...
LATEST IR SATELLITE IMAGERY AND RUC ANALYSIS SHOWED A SHORT WAVE
TROUGH MOVING ACROSS THE NORTHERN CONUS WITH AREAS OF CLOUDS AHEAD
OF IT. FURTHER SOUTH THE CLOSED LOW CONTINUES TO SPIN OVER EASTERN
NEW MEXICO AND WESTERN TEXAS. CURRENT RADAR SHOWS ECHOES OVER
SOUTHWEST KANSAS AS SOME MOISTURE MOVES UP FROM THE CLOSED LOW...WITH
A FEW SPRINKLES AND LIGHT SNOW REACHING THE GROUND. AT THE SURFACE
A HIGH PRESSURE WAS PROGRESSING OUT OF THE TRI-AREA AHEAD OF THE
PRE-FRONTAL TROUGH THAT WILL MOVE THROUGH TODAY.
JTL
&&
.SHORT TERM (TODAY-WEDNESDAY)...
227 AM MST MON DEC 26 2011
TEMPERATURES WILL BE THE MAIN FOCUS FOR THIS PERIOD.
TODAY A PRE-FRONTAL SURFACE TROUGH WILL MOVE THROUGH THE AREA DURING
THE DAY...CAUSING THE SOUTHWEST WINDS TO SHIFT TO THE NORTHWEST.
WITH LITTLE MOISTURE TO WORK WITH...AM ONLY ANTICIPATING STRONGER
WINDS AND A FEW CLOUDS BEHIND THE TROUGH. HIGH TEMPERATURES WILL BE
SIMILAR TO YESTERDAY.
TUESDAY THROUGH WEDNESDAY...ANOTHER SURFACE AND UPPER LEVEL TROUGH
WILL MOVE THROUGH THE TRI-STATE AREA DURING THE LATE AFTERNOON AND
EVENING HOURS. SOUNDINGS AND CROSS SECTIONS SHOW UPPER LEVEL
MOISTURE INCREASING AS THE TROUGH MOVES THROUGH. THERE ALSO IS SOME
INSTABILITY PRESENT...ALONG WITH LIFT FROM FRONTOGENESIS AND WARM
AIR ADVECTION AS THE TROUGH MOVES THROUGH. HOWEVER A NARROW LAYER
OF MUCH DRIER AIR BETWEEN THE SURFACE AND THE MOISTURE MAY HINDER
ANY PRECIPITATION FROM REACHING THE GROUND. CANNOT COMPLETELY RULE
OUT SOMETHING FROM REACHING THE GROUND SO WILL ADD A MENTION OF
FLURRIES FOR AREAS NORTH OF A BENKELMAN TO HILL CITY LINE. TEMPERATURES
WILL BE COOLER TUESDAY AS SLIGHTLY COOLER AIR WILL MOVE IN BEHIND
MONDAY/S TROUGH. WEDNESDAY THE ENVIRONMENT DRIES OUT BEHIND THE
TROUGH. TEMPERATURES WILL BE WARMER AS 850MB TEMPERATURES
INCREASE.
JTL
.LONG TERM (THURSDAY-SUNDAY)...
227 AM MST MON DEC 26 2011
A SERIES OF WEAK SHORT WAVE TROUGHS WILL MOVE ACROSS
THE HIGH PLAINS THROUGH THE REST OF THE WEEK...BUT BEST LIFT AND
MOISTURE WILL BE FAR NORTH OF THE FORECAST AREA. MODELS INDICATE THE
BEST CHANCE FOR ANY PRECIPITATION WOULD BE TOWARD THE END OF THE
PERIOD...SATURDAY NIGHT/SUNDAY MORNING. MODELS DIFFER IN THEIR
SOLUTIONS AT THAT TIME. THE ECMWF IS FURTHER SOUTH AND WEST WITH
DYNAMICS AND MOISTURE THAN THE GFS. WITH ENSEMBLES SHOWING WIDE
VARIABILITY AFTER 120 HOURS...WILL STAY THE COURSE OF A DRY
FORECAST. TEMPERATURES WILL BE ABOVE NORMAL WITH DAILY MAXIMUM
TEMPERATURES MAINLY IN THE 50S.
&&
.AVIATION...
1013 AM MST MON DEC 26 2011
FOR THE 18Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD
AT BOTH TERMINALS. A COLD FRONT WILL MOVE THROUGH THE TERMINALS
DURING THE FIRST HOUR OF THE PERIOD...CAUSING WINDS TO SHIFT TO
THE NORTHWEST AND BECOME STRONGER. BEHIND THE FRONT...WINDS WILL
INCREASE FURTHER AND VEER SLIGHTLY MORE. WINDS WILL DECREASE NEAR
00Z AS DAYTIME MIXING ENDS.
CJS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1013 AM MST MON DEC 26 2011
.SYNOPSIS...
LATEST IR SATELLITE IMAGERY AND RUC ANALYSIS SHOWED A SHORT WAVE
TROUGH MOVING ACROSS THE NORTHERN CONUS WITH AREAS OF CLOUDS AHEAD
OF IT. FURTHER SOUTH THE CLOSED LOW CONTINUES TO SPIN OVER EASTERN
NEW MEXICO AND WESTERN TEXAS. CURRENT RADAR SHOWS ECHOES OVER
SOUTHWEST KANSAS AS SOME MOISTURE MOVES UP FROM THE CLOSED LOW...WITH
A FEW SPRINKLES AND LIGHT SNOW REACHING THE GROUND. AT THE SURFACE
A HIGH PRESSURE WAS PROGRESSING OUT OF THE TRI-AREA AHEAD OF THE
PRE-FRONTAL TROUGH THAT WILL MOVE THROUGH TODAY.
JTL
&&
.SHORT TERM (TODAY-WEDNESDAY)...
227 AM MST MON DEC 26 2011
TEMPERATURES WILL BE THE MAIN FOCUS FOR THIS PERIOD.
TODAY A PRE-FRONTAL SURFACE TROUGH WILL MOVE THROUGH THE AREA DURING
THE DAY...CAUSING THE SOUTHWEST WINDS TO SHIFT TO THE NORTHWEST.
WITH LITTLE MOISTURE TO WORK WITH...AM ONLY ANTICIPATING STRONGER
WINDS AND A FEW CLOUDS BEHIND THE TROUGH. HIGH TEMPERATURES WILL BE
SIMILAR TO YESTERDAY.
TUESDAY THROUGH WEDNESDAY...ANOTHER SURFACE AND UPPER LEVEL TROUGH
WILL MOVE THROUGH THE TRI-STATE AREA DURING THE LATE AFTERNOON AND
EVENING HOURS. SOUNDINGS AND CROSS SECTIONS SHOW UPPER LEVEL
MOISTURE INCREASING AS THE TROUGH MOVES THROUGH. THERE ALSO IS SOME
INSTABILITY PRESENT...ALONG WITH LIFT FROM FRONTOGENESIS AND WARM
AIR ADVECTION AS THE TROUGH MOVES THROUGH. HOWEVER A NARROW LAYER
OF MUCH DRIER AIR BETWEEN THE SURFACE AND THE MOISTURE MAY HINDER
ANY PRECIPITATION FROM REACHING THE GROUND. CANNOT COMPLETELY RULE
OUT SOMETHING FROM REACHING THE GROUND SO WILL ADD A MENTION OF
FLURRIES FOR AREAS NORTH OF A BENKELMAN TO HILL CITY LINE. TEMPERATURES
WILL BE COOLER TUESDAY AS SLIGHTLY COOLER AIR WILL MOVE IN BEHIND
MONDAY/S TROUGH. WEDNESDAY THE ENVIRONMENT DRIES OUT BEHIND THE
TROUGH. TEMPERATURES WILL BE WARMER AS 850MB TEMPERATURES
INCREASE.
JTL
.LONG TERM (THURSDAY-SUNDAY)...
227 AM MST MON DEC 26 2011
A SERIES OF WEAK SHORT WAVE TROUGHS WILL MOVE ACROSS
THE HIGH PLAINS THROUGH THE REST OF THE WEEK...BUT BEST LIFT AND
MOISTURE WILL BE FAR NORTH OF THE FORECAST AREA. MODELS INDICATE THE
BEST CHANCE FOR ANY PRECIPITATION WOULD BE TOWARD THE END OF THE
PERIOD...SATURDAY NIGHT/SUNDAY MORNING. MODELS DIFFER IN THEIR
SOLUTIONS AT THAT TIME. THE ECMWF IS FURTHER SOUTH AND WEST WITH
DYNAMICS AND MOISTURE THAN THE GFS. WITH ENSEMBLES SHOWING WIDE
VARIABILITY AFTER 120 HOURS...WILL STAY THE COURSE OF A DRY
FORECAST. TEMPERATURES WILL BE ABOVE NORMAL WITH DAILY MAXIMUM
TEMPERATURES MAINLY IN THE 50S.
&&
.AVIATION...
1013 AM MST MON DEC 26 2011
FOR THE 18Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD
AT BOTH TERMINALS. A COLD FRONT WILL MOVE THROUGH THE TERMINALS
DURING THE FIRST HOUR OF THE PERIOD...CAUSING WINDS TO SHIFT TO
THE NORTHWEST AND BECOME STRONGER. BEHIND THE FRONT...WINDS WILL
INCREASE FURTHER AND VEER SLIGHTLY MORE. WINDS WILL DECREASE NEAR
00Z AS DAYTIME MIXING ENDS.
CJS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS DODGE CITY KS
1042 AM CST MON DEC 26 2011
.AVIATION...
FOR THE 18Z TAF ISSUANCE...
A NORTHERN BRANCH SHORTWAVE TROUGH WILL MOVE ACROSS THE NORTHERN
HIGH PLAINS AND INTO THE UPPER MIDWEST BY 12Z TUES. THIS SYSTEM
WILL PUSH A DRY COLD FRONT ACROSS WESTERN KANSAS THIS EVENING.
WINDS WILL SHIFT FROM THE SOUTHWEST TO THE NORTHWEST AT 10 TO
15 KTS BY 00Z AT KDDC, AND AROUND 23Z AT KHYS AND KGCK. VFR
CONDITIONS ARE EXPECTED WITH ONLY SOME SCT HIGH LEVEL CIRRUS.
&&
PREV DISCUSSION... /ISSUED 222 AM CST MON DEC 26 2011/
SYNOPSIS...
MID AND UPPER AIR ANALYSIS INDICATES A SHORTWAVE TROUGH PUSHING ACROSS
MONTANA. A 500 HPA LOW WAS SPINNING ACROSS THE WESTERN TEXAS PANHANDLE.
MOISTURE ADVECTION WAS EVIDENT ON THE KDDC RAOB AS THE MIDDLE ATMOSPHERE
MOISTENED UP CONSIDERABLY IN THE 12 HOUR GAP BETWEEN SYNOPTIC FLIGHTS.
KDDC WSR-88D WAS DETECTING SOME LIGHT ECHOES ACROSS SOUTH CENTRAL KANSAS.
A QUICK CALL MADE TO BARBER COUNTY INDICATES SOME SPRINKLES WERE OCCURRING
WITHIN THE COUNTY. -SUGDEN
DISCUSSION...
DAYS 1-2...
TODAY:
THE IMMEDIATE SHORT TERM CONCERN WAS TO TREND POPS AND WX TO RADAR TRENDS
ACROSS SOUTH CENTRAL KANSAS. THIS ACTIVITY WAS IN RESPONSE TO 600-700
HPA FRONTOGENESIS. HAVE FOLLOWED HRRR GUIDANCE ON THE DEPARTURE OF THIS
ACTIVITY THROUGH THE MORNING. FORECAST SOUNDINGS SHOW A DRY THERMODYNAMIC
PROFILE BELOW 850 HPA SO THINK MOST OF THIS ACTIVITY IS EVAPORATING
BEFORE REACHING THE SURFACE. HAVE KEPT 15 PERCENT POPS IN THE GRIDS
AND WILL QUICKLY TAPER TO ZERO TOWARDS 15Z THIS MORNING. OTHER CONCERN
IS A 5KFT STRATUS LAYER THAT HAS SPREAD ACROSS MUCH OF SOUTHWEST KANSAS.
THINK THIS WILL MOVE OFF TO THE EAST AND REDUCE IN AERIAL COVERAGE WITH
MIXING TOWARDS MID MORNING.
MEANWHILE, THE AFOREMENTIONED UPPER LEVEL SHORTWAVE TROUGH MENTIONED
IN THE SYNOPSIS WILL USHER IN A COLD FRONT TONIGHT. PRECIPITATION IS
NOT EXPECTED ALONG THE BOUNDARY AS THE ATMOSPHERE IS FAIRLY DRY AND
DRY AIR ADVECTION WILL CONTINUE IN THE WAKE OF THE SURFACE BOUNDARY.
THE MAIN IMPACTS FROM THE DENSITY GRADIENT WILL BE A SHIFT IN THE WINDS.
HIGHS TODAY WILL BE MAINLY IN THE 30S DEG F FOR MUCH OF THE COUNTY WARNING
AREA EXCEPT TOWARDS SOUTH CENTRAL KANSAS WHERE 40S DEG F ARE FORECAST.
A CONTINUATION OF THE EROSION OF THE SNOWPACK IS EXPECTED TODAY, PARTICULARLY
ACROSS THE EASTERN SECTIONS OF THE SNOWPACK.
TONIGHT:
POST FRONTAL 10 TO 15 KT NORTHWESTERLY TO NORTHERLY WINDS ARE EXPECTED
TONIGHT AND THROUGH THE OVERNIGHT HOURS. MINIMUMS SHOULD BE WARMER HEADING
INTO TUESDAY MORNING AS WINDS CONTINUE IN THE 5 TO 10 KT RANGE OVERNIGHT AND
PROVIDE SLIGHTLY MORE MIXING. TEENS TO UPPER 20 DEG F ARE EXPECTED ACROSS
THE REGION WITH THE COOLEST TEMPERATURES ACROSS MY NORTHWEST COUNTIES.
TUESDAY:
A SURFACE RIDGE OF HIGH PRESSURE WILL SLIDE ACROSS KANSAS TUESDAY.
SOUTHERLY WINDS ARE EXPECTED ON THE BACKSIDE OF THE HIGH BY TUESDAY
EVENING ACROSS WESTERN KANSAS. LOW 50S DEG F TEMPERATURES ARE POSSIBLE
TOWARDS P28 TOMORROW. OTHERWISE MOST OF THE REGION SHOULD BE IN THE
UPPER 30S DEG F (MAINLY ACROSS SNOWPACK) AND 40S DEG F ACROSS BARE GROUND.
THE SNOWPACK WILL CONTINUE TO ERODE THROUGH THE DAY ON TUESDAY.
TUESDAY NIGHT:
I HAVE INCREASED CLOUD COVER TUESDAY EVENING INTO WEDNESDAY MORNING
AS MID TO UPPER LEVEL SATURATION IS INDICATED BY FORECAST SOUNDINGS
AHEAD OF A SECONDARY APPROACHING SHORTWAVE TROUGH MOVING ACROSS THE
PLAINS. MODELS ARE NOT INDICATING ANY QPF WITH THIS SYSTEM SO STILL
HAVE POPS AT ZERO THROUGH THE EVENING. FORECAST SOUNDINGS ALSO SHOW
A DRY PROFILE BELOW 700 HPA WHICH SUPPORTS A DRY FORECAST. -SUGDEN
DAYS 3-7...
THE MEDIUM RANGE FORECAST CONTINUES TO LOOK WARM AND DRY IN A PROLONGED
DOWNSLOPE-FAVORED UPPER AIR PATTERN...WITH NO HAZARDOUS WINTER WEATHER
EXPECTED FOR MUCH OF THE WESTERN PLAINS. THAT BEING SAID...WILL BE WATCHING
FOR POSSIBLE STORM DEVELOPMENT EAST OF HERE AROUND THE 1ST OF JANUARY
AS THE LARGE SCALE CIRCULATION REGIME AMPLIFIES.
WEDNESDAY-FRIDAY:
WEST-NORTHWESTERLY DOWNSLOPE MOMENTUM WILL YIELD A WARMING LOWER TROPOSPHERE
AND DAILY TEMPERATURES WARMING INTO THE 50S. WHATEVER SNOWPACK REMAINS
BY WEDNESDAY WILL BE TAKING A SERIOUS HIT DURING THIS TIME FRAME WITH
ALMOST NO INFLUENCE AT ALL OF SNOWPACK ON TEMPERATURES BY THE END OF
THE WEEK AS MUCH OF IT SHOULD BE MELTED BY THEN (EXCEPT FOR THE COLORADO
BORDER AREAS). HIGHS IN THE MID 50S ARE LIKELY AND PERHAPS A FEW 60
DEGREE READINGS WILL OCCUR ACROSS SOUTH-CENTRAL KANSAS ZONES THURSDAY
AND FRIDAY.
SATURDAY-SUNDAY:
A LARGE RIDGE IS EXPECTED TO FORM ALONG THE WEST COAST/WESTERN CONUS
WHICH WILL FAVOR A DOWNSTREAM TROUGH DEVELOPMENT OVER THE CENTRAL/EASTERN
PLAINS. THE FORMATION OF THIS TROUGH IS SHOWN BY ALL THE GLOBAL MODELS
TO BE OVER OR EAST OF WESTERN KANSAS WHICH DOES NOT FAVOR WIDESPREAD
ACCUMULATING PRECIPITATION GIVEN UNFAVORABLE LOW LEVEL TRAJECTORIES
TO OUR SOUTH (MOISTURE ADVECTION). A MID LATITUDE CYCLONE OF SOME SEMBLANCE
WILL PROBABLY MATURE OVER THE MIDWEST /OHIO-VALLEY AS A RESULT OF THIS
TROUGH DEVELOPMENT WITH STRONG, DRY NORTHWEST WINDS ACROSS THE WESTERN
PLAINS ON THE ORDER OF LATE SATURDAY INTO SUNDAY. SINCE THIS IS STILL
IN THE DAY 6-7 TIME RANGE THERE IS STILL SOME UNCERTAINTY AS TO WHEN/WHERE
(OR EVEN IF) EXACTLY A STORM WILL FORM SO WILL HAVE TO WATCH SUBSEQUENT
MODEL SOLUTIONS TO SEE HOW THIS TROUGH DEVELOPS AND IF IT WILL HAVE
ANY SUBSTANTIAL SENSIBLE WEATHER IMPACTS ON SOUTHWEST KANSAS.
&&
.PRELIMINARY POINT TEMPS/POPS...
DDC 36 21 42 23 / 0 0 0 0
GCK 33 17 37 19 / 0 0 0 0
EHA 35 21 43 25 / 0 0 0 0
LBL 36 19 45 22 / 0 0 0 0
HYS 37 23 41 25 / 0 0 0 0
P28 44 26 50 26 / 10 0 0 0
&&
.DDC WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
FN06/99/99
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
404 PM EST MON DEC 26 2011
.SYNOPSIS...
HIGH PRESSURE WILL MOVE INTO THE MID-ATLANTIC WITH A DRY FORECAST
TONIGHT. A LOW PRESSURE SYSTEM WILL MOVE INTO THE AREA TUESDAY,
BRINGING MOSTLY RAIN TO THE AREA WITH A MIX OF RAIN AND SNOW
POSSIBLE NORTH OF PITTSBURGH. PRECIPITATION WILL CHANGE TO ALL SNOW
TUESDAY NIGHT AS THE LOW SHIFTS NORTHEAST OF THE AREA.
&&
.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
THE LATEST RUC ANALYSIS INDICATES A WEAK 500MB RIDGE CENTERED
ACROSS THE OHIO VALLEY. AT THE SURFACE, A 1027MB HIGH IS CENTERED
WESTERN PENNSYLVANIA. THIS FEATURE HAS CONTRIBUTED TO CLEARING
SKIES, ALTHOUGH CIRRUS IS BEGINNING TO SPILL INTO THE AREA AHEAD
OF THE NEXT SYSTEM TO THE SOUTHWEST.
TONIGHT...THE SURFACE HIGH WILL MOVE OFF THE MID-ATLANTIC COAST
OVERNIGHT AS CYCLOGENESIS OCCURS ACROSS THE CENTRAL GULF COAST.
THIS LOW WILL CONTINUE TO STRENGTHEN, PROGGED TO BE OVER THE TN
VALLEY BY DAWN ON TUESDAY. WEAK RIDGING WILL KEEP THE FORECAST DRY
ACROSS MOST OF THE AREA UNTIL NEAR DAWN ON TUESDAY WHEN 290K
ISENTROPIC LIFT SHIFTS EASTERN OHIO. TEMPS MAY DROP A FEW DEGREES
INITIALLY TONIGHT, ALTHOUGH 850MB TEMPS SUPPORT WARM AIR ADVECTION
KICKING IN, WITH TEMPS STEADYING OFF AND BEGINNING TO INCREASE
AFTER 06Z. THUS, OVERNIGHT LOWS WILL LIKELY BE REACHED AROUND
MIDNIGHT, RANGING FROM NEAR 30 ACROSS I-80 CORRIDOR AND EASTERN
RIDGES TO THE MID 30S ACROSS PORTIONS OF EASTERN OHIO AND NORTH-
CENTRAL WV.
&&
.SHORT TERM /6 AM TUESDAY MORNING THROUGH THURSDAY/...
STILL SOME UNCERTAINTY IN THE TIMING OF PRECIP TYPE WITH THE
FORECAST ON TUESDAY INTO TUESDAY NIGHT, ALTHOUGH OPERATIONAL MODELS
HAVE SHOWN CONSISTENCY BETWEEN THE 00Z/12Z RUNS WITH A POTENTIAL
RAIN/SNOW EVENT FOR THE UPPER OHIO VALLEY.
IN THE MID TO UPPER LEVELS THERE WILL BE TWO PIECES OF ENERGY
APPROACHING FROM THE WEST, A NORTHERN STREAM TROUGH APPROACHING FROM
THE UPPER MIDWEST AND A SOUTHERN STREAM CLOSED LOW ACROSS THE
ARKLATEX THAT WILL OPEN UP INTO A TROUGH AS IT CROSSES THE TENNESSEE
VALLEY. THE SOUTHERN STREAM TROUGH LOOKS TO MOVE A BIT FASTER INTO
THE AREA BEFORE THE NORTHERN SYSTEM, THUS LIMITING THEIR ABILITY TO
PHASE.
IN THE LOWER LEVELS, THE NORTHERN AND SOUTHERN STREAM SURFACE LOWS
DO NOT MERGE UNTIL THE SYSTEM HAS PUSHED NORTHEAST OF THE AREA INTO
NEW ENGLAND. IN ADDITION, MODEL SOUNDINGS INDICATE A WARM NOSE OF
3-5C IN A 1000-800MB MELTING LAYER BETWEEN 12Z TUES AND 00Z TUES. IN
THIS SCENARIO, THE BULK OF THE HEAVIEST PRECIPITATION WILL CROSS THE
APPALACHIANS WITH THE WARM WEDGE KEEPING PRECIP IN THE FORM OF RAIN
THROUGHOUT THE DAY TUESDAY. DO HAVE A FEW HOURS WITH THE CHANCE OF
FREEZING RAIN FOR THE VALLEYS IN GARRETT AND TUCKER COUNTIES AT
THE ONSET OF PRECIP, SO WILL NEED TO MONITOR TEMPS THERE. TEMPS ON
TUESDAY WERE ADJUSTED UP A FEW DEGREES FOR AREAS NORTH OF THE I-70
CORRIDOR. HIGHS WILL RANGE FROM THE MID 40S ACROSS PORTIONS OF
EASTERN OHIO, NORTH- CENTRAL WV, AND SOUTHWEST PA TO THE UPPER 30S
ACROSS I-80 CORRIDOR.
TUESDAY NIGHT...THE NORTHERN STREAM MID-LEVEL TROUGH WILL SHIFT EAST
ACROSS THE AREA AS THE MERGED SURFACE LOW WILL MOVE NORTHWARD FROM
THE NY INTO EASTERN CANADA. THIS WILL ALLOW FOR COLD AIR ADVECTION
TO ENSUE BEGINNING AROUND 00Z. THE TURN OVER TO SNOW SEEMS QUITE
APPARENT SHORTLY AFTER SUNSET, ALTHOUGH THERE IS UNCERTAINTY IN
REGARDS TO HOW MUCH MOISTURE AND LIFT WILL BE LINGERING WITH THIS
SYSTEM.
THE NAM INDICATES A WEAK DEFORMATION ZONE PASSING ACROSS THE AREA
WITH A NORTHWESTERLY, UPSLOPING FLOW ENSUING. AT THIS TIME, BELIEVE
THE CHANGEOVER TO SNOW WILL OCCUR NEAR SUNSET THE I-80 CORRIDOR WITH
UPSLOPING KICKING IN FOR THE RIDGES AFTER MIDNIGHT. WITH THE SPREAD OF
OPERATIONAL MODELS, THIS SCENARIO LIMITS THE SNOW FORECAST TO LESS
THAN 2 INCHES FOR THE LOWLANDS OF SOUTHWEST PA WITH LESS THAN AN
INCH IN OHIO AND NORTHERN WV. POTENTIAL WINTER WEATHER ADVISORY
CRITERIA COULD BE REACHED WITH 2-4 INCHES FOR THE I-80 CORRIDOR
AND EASTERN RIDGES. REGARDLESS OF THE AMOUNT OF SNOW, TEMPS
DROPPING INTO THE UPPER 20S TUESDAY NIGHT AND RAIN PRECEDING THE
CHANGEOVER COULD CONTRIBUTE TO SLICK CONDITIONS ON ROADWAYS
DEVELOPING ACROSS MUCH OF WESTERN PA, NORTH-CENTRAL WV, AND
WESTERN MD TUESDAY NIGHT.
WEDNESDAY AND WEDNESDAY NIGHT...A FEW LINGERING SNOW SHOWERS WILL BE
POSSIBLE IN A NORTHWESTERLY FLOW IN THE WAKE OF THIS SYSTEM EARLY
IN THE DAY. THERE IS REASONABLE ECMWF/GFS AGREEMENT AFTER THIS POINT
THAT HIGH PRESSURE WILL BUILD IN FROM THE SOUTHWEST AND ALLOW FOR
DRY WEATHER. WITH ONGOING COLD AIR ADVECTION, TEMPS WILL BE FAIRLY
STEADY IN THE UPPER 20S TO LOWER 30S ON WEDNESDAY. STRONG
RADIATIONAL COOLING ON WEDNESDAY NIGHT WILL ALLOW FOR OVERNIGHT
LOWS RANGING FROM THE UPPER TEENS ACROSS THE EASTERN RIDGES AND
I-80 CORRIDOR TO THE LOWER 20S ELSEWHERE.
THURSDAY...GFS/NAM/ECMWF ARE HINTING AT A SHORT WAVE DROPPING FROM
THE NORTHERN GREAT LAKES INTO NY. THIS SYSTEM MAY CLIP THE UPPER
OHIO VALLEY WITH CHANCE POPS NORTH OF PITTSBURGH. 1000-500MB
THICKNESS 5400M LINE ENCROACHES FROM THE SOUTHWEST THROUGHOUT THE
DAY, ALTHOUGH BELIEVE PRECIP WILL BE MOSTLY IN THE FORM OF SNOW
SHOWERS. IF THE SYSTEM DROPS FURTHER SOUTH, BELIEVE ITS ASSOCIATED
COLDER AIR WILL DOMINATE. TEMPERATURES WILL BE NEAR NORMAL SEASONAL
VALUES.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
FAST MOVING SYSTEMS IN PROGRESSIVE FLOW WILL BRING TEMPERATURES
AVERAGING ABOVE NORMAL AND CHANCES FOR RAIN OR SNOW SHOWERS FOR
LATE WEEK INTO THE WEEKEND. LONG TERM PERIOD WAS FORECAST CLOSE TO
HPC PROGS WHICH CONTINUE TO TREND TOWARD THE ECMWF.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
EROSION OF THE STRATOCU DECK FROM WEST TO EAST THIS AFTERNOON WILL
LEAD TO VFR OVERNIGHT. AS LOW PRESSURE MOVES NORTHEAST INTO THE OHIO
VALLEY RAIN WILL OVER SPREAD THE REGION TUESDAY WITH CIGS AND VSBY
REDUCED TO IFR FROM MID MORNING WEST TO MID AFTERNOON FAR EAST.
EXPECT IFR TO CONTINUE INTO TUESDAY NIGHT AS PRECIPITATION
TRANSITIONS TO SNOW IN THE EVENING WITH IFR SNOW SHOWERS IN
NORTHWEST FLOW BEHIND LOW PRESSURE TUESDAY NIGHT.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
CONDITIONS WILL IMPROVE DURING THE DAY WEDNESDAY WITH VFR
EXPECTED BY LATE DAY AS A WEAK SURFACE RIDGE MOVES EAST. A SERIES
OF FAST MOVING WEATHER SYSTEMS WILL THEN CROSS THE REGION THURSDAY
THROUGH SATURDAY WITH RESTRICTIONS POSSIBLE AT TIMES THROUGH THE
PERIOD.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1253 PM EST MON DEC 26 2011
.SYNOPSIS...
HIGH PRESSURE WILL PROVIDE DRY WEATHER AND SEASONABLE TEMPERATURES
FOR THE REST OF TODAY AND TONIGHT. A STORM SYSTEM WILL BRING A MIX
OF RAIN AND SNOW TO THE AREA TUESDAY AND THEN SNOW TUESDAY
NIGHT.
&&
.NEAR TERM /THROUGH TONIGHT/...
18Z ENHANCED SHORT TERM FORECAST UPDATE HAS BEEN ISSUED TO ADJUST
SKY GRIDS AND TO WARM OVERNIGHT TEMPS AFTER 06Z TONIGHT.
THE LATEST RUC ANALYSIS INDICATES A WEAK 500MB RIDGE CENTERED
ACROSS THE GREAT LAKES WITH THE UPPER OHIO VALLEY IN A
NORTHWESTERLY FLOW AHEAD OF THIS FEATURE. MOIST 850MB FLOW OFF IS
CUTTING OFF WITH STRATOCUMULUS LINGERING EAST OF PITTSBURGH. AT
THE SURFACE, A 1029MB HIGH IS CENTERED ACROSS SOUTHERN OHIO. THIS
FEATURE IS MOVING NORTHEAST TOWARD THE AREA, CONTRIBUTING TO THE
ERODING CLOUD DECK WITH CLEARING MOVING INTO WESTERN PENNSYLVANIA.
TODAY...THE WEAK RIDGE WILL MOVE ACROSS THE AREA WITH THE SURFACE
HIGH MOVING INTO THE MID-ATLANTIC. THIS WILL ALLOW FOR THE CLOUD
DECK TO ERODE, WITH MOSTLY SUNNY SKIES BY THIS AFTERNOON. CIRRUS
WILL THEN BEGIN TO ADVECT INTO THE AREA FROM THE SOUTHWEST THIS
EVENING. TAKING INTO ACCOUNT LATEST OBS AND LAMP GUIDANCE, TEMPS
HAVE BEEN WARMED A FEW DEGREES. HIGHS WILL RANGE FROM THE NEAR 40
ACROSS THE EASTERN RIDGES AND I-80 CORRIDOR TO THE MID 40S IN
PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV.
TONIGHT...THE SURFACE HIGH WILL MOVE OFF THE MID-ATLANTIC COAST
LATE AS CYCLOGENESIS OCCURS ACROSS THE CENTRAL GULF COAST. THIS
LOW WILL CONTINUE TO STRENGTHEN, PROGGED TO BE OVER THE TN VALLEY
BY DAWN ON TUESDAY. WEAK RIDGING WILL KEEP THE FORECAST DRY ACROSS
MOST OF THE AREA UNTIL NEAR DAWN ON TUESDAY WHEN 290K ISENTROPIC
LIFT SHIFTS EASTERN OHIO. TEMPS MAY DROP A FEW DEGREES INITIALLY
TONIGHT, ALTHOUGH 850MB TEMPS SUPPORT WARM AIR ADVECTION KICKING
IN, WITH TEMPS STEADYING OFF AND BEGINNING TO INCREASE AFTER 06Z.
THUS, OVERNIGHT LOWS WILL LIKELY BE REACHED AROUND MIDNIGHT,
RANGING FROM NEAR 30 ACROSS I-80 CORRIDOR AND EASTERN RIDGES TO
THE MID 30S ACROSS PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV.
&&
.SHORT TERM /TUESDAY THROUGH WEDNESDAY/...
VERY DIFFICULT FORECAST TUESDAY AND TUESDAY NIGHT.
A SFC LOW WILL DEVELOP OVER THE GULF COAST STATES AND MOVE INTO
THE TN VALLEY BY DAWN TUESDAY. AT THE UPPER LEVELS, EASTERN RIDGE
WILL BEGIN TO BREAK DOWN TONIGHT AS UL ENERGY MOVE ACROSS THE
MIDWEST. ALSO, UL LOW WILL MOVE ACROSS THE GULF COAST STATES.
THESE TWO PIECES OF ENERGY WILL BE EXTREMELY IMPORTANT TO
TUESDAY`S FORECAST. THE NORTHERN DISTURBANCE WILL HELP TO PUSH
COLDER AIR TOWARD THE REGION. THE SOUTHERN DISTURBANCE WILL PUSH
MOISTURE NORTHWARD AND ALSO DEVELOP THE SFC LOW. AT THIS POINT, IT
APPEARS THAT THE SOUTHERN ENERGY WILL WIN THE RACE INTO THE AREA.
WHAT THIS MEANS FOR THE FORECAST, IS MORE OF A RAIN EVENT ON
TUESDAY AS THE WARMER AIR WILL INITIALLY COVER THE AREA.
THE FIRST QUESTION TO DEAL WITH IS HOW QUICKLY WILL THE
PRECIPITATION BEGIN. MODELS CONTINUE TO SLOW THE ONSET OF
PRECIPITATION AS THE VERY DRY AIR MASS OVER THE MID-ATLANTIC WILL
NOT EASILY BE MOVED. WILL HOLD OFF ON A MENTION OF POPS UNTIL JUST
BEFORE DAWN TUESDAY OVER THE WEST. ON TUESDAY MORNING, WILL
INCREASE POPS FROM WEST TO EAST AS THE PRECIP SHIELD COVERS THE
ENTIRE AREA. CURRENT BELIEF IS THAT PRECIP WILL BEGIN AS RAIN AS
IT MOVES INTO THE AREA. HOWEVER, AS COLDER AIR MOVES ACROSS THE
MIDWEST, IT APPEARS THAT A MIX OF RAIN AND SNOW IS A GOOD
POSSIBILITY ACROSS THE NORTH AND WEST AS THE DAY PROGRESSES.
THE COLDER AIR SHOULD FINALLY OVERTAKE THE REGION TUESDAY EVENING ON
THE HEELS OF A SFC COLD FRONT. THIS WILL BRING A CHANGE OVER TO
ALL SNOW DURING THE EVENING HOURS. TIMING HERE IS STILL A BIG
QUESTION AS THERE CONTINUE TO BE MODEL DISCREPANCIES AND MANY
VARIABLES CONTRIBUTING TO THE COLD AIR INTRUSION.
RIGHT AFTER 00Z WED, MODELS ARE INDICATING A DEFORMATION ZONE
AND AREA OF MID-LEVEL FRONTOGENESIS DEVELOPING AND SWINGING
THROUGH THE AREA. THESE FEATURES HINT AT THE POSSIBILITY OF A
BAND OF ACCUMULATING SNOW DEVELOPING AND ROTATING THROUGH THE
AREA.
SFC LOW WILL DEEPEN OVER SE PA TUESDAY EVENING AND MOVE RAPIDLY
TOWARD THE NE. WITH THE SFC SYSTEM INCREASING FORWARD SPEED,
EXPECT THE SNOW TO TAPER OFF QUICKLY LATE TUESDAY NIGHT.
SFC HIGH WILL BUILD IN ON WEDNESDAY. TEMPERATURES WILL BE BELOW
NORMAL BUT CONDITIONS SHOULD BE DRY.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/...
FAST MOVING SYSTEMS IN PROGRESSIVE FLOW WILL BRING TEMPERATURES
AVERAGING ABOVE NORMAL AND CHANCES FOR RAIN OR SNOW SHOWERS FOR
LATE WEEK INTO THE WEEKEND. LONG TERM PERIOD WAS FORECAST CLOSE TO
HPC PROGS WHICH CONTINUE TO TREND TOWARD THE ECMWF.
&&
.AVIATION /18Z MONDAY THROUGH SATURDAY/...
EROSION OF THE STRATOCU DECK FROM WEST TO EAST THIS AFTERNOON WILL
LEAD TO VFR OVERNIGHT. AS LOW PRESSURE MOVES NORTHEAST INTO THE OHIO
VALLEY RAIN WILL OVER SPREAD THE REGION TUESDAY WITH CIGS AND VSBY
REDUCED TO IFR FROM MID MORNING WEST TO MID AFTERNOON FAR EAST.
EXPECT IFR TO CONTINUE INTO TUESDAY NIGHT AS PRECIPITATION
TRANSITIONS TO SNOW IN THE EVENING WITH IFR SNOW SHOWERS IN
NORTHWEST FLOW BEHIND LOW PRESSURE TUESDAY NIGHT.
OUTLOOK...WEDNESDAY THROUGH SATURDAY...
CONDITIONS WILL IMPROVE DURING THE DAY WEDNESDAY WITH VFR
EXPECTED BY LATE DAY AS A WEAK SURFACE RIDGE MOVES EAST. A SERIES
OF FAST MOVING WEATHER SYSTEMS WILL THEN CROSS THE REGION THURSDAY
THROUGH SATURDAY WITH RESTRICTIONS POSSIBLE AT TIMES THROUGH THE
PERIOD.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1230 PM CST MON DEC 26 2011
...PERIODS OF HEAVY RAIN TODAY WITH QUIETER WEATHER WEEK AHEAD...
.UPDATE...QUICK UPDATE TO KNOCK ABOUT 5 DEGREES OFF AFTERNOON TEMPS
BASED ON LATEST TRENDS. PERSISTENT RAINFALL KEEPING WARM ADVECTION
FROM HELPING NEAR SURFACE TEMPS MUCH. PRECIP TRENDS LOOK GOOD AS
PRECIPITATION IS FILLING BACK IN TO THE S AND W AS IR SHOWS TOPS
RAPIDLY COOLING ACROSS AREA AS ASCENT INCREASES AHEAD OF EJECTING
UPPER LOW.
&&
.AVIATION...MVFR CONDITIONS IN EAST MS WILL SLOWLY DETERIORATE
THROUGH EARLY AFTERNOON LEAVING WIDESPREAD IFR AT ALL TAF SITES AS
AREAS OF STEADY RAIN PERSIST AND INCREASE. THE RISK OF SCATTERED
TSRA WILL ALSO INCREASE THROUGH 06Z TONIGHT PRODUCING OCCASIONAL
LIFR REPORTS BEFORE TAPERING OFF FROM W TO E FROM 08-12Z TUESDAY.
CONDITIONS SHOULD IMPROVE TO MVFR TUESDAY MORNING 14-18Z WITH RAIN
ENDING AND THEN FINALLY VFR CEILINGS RETURNING DURING THE MIDDLE
AFTERNOON. OVERALL SURFACE WINDS WILL PERSIST ESE AT 10-16KTS TODAY
AND BE VARIABLE TONIGHT BEFORE INCREASING FROM THE NW AT 12-18KTS
EARLY TUESDAY MORNING./40/
&&
.HYDROLOGY...SMALL CONVECTIVE COMPLEXES HAVE BEEN AFFECTING PARTS OF
S MS THIS MORNING...WITH A BAND OF 2 TO 4 INCHES OF RAINFALL HAVING
AFFECTED PARTS OF SE MS AND A FFW HAVING BEEN RECENTLY ISSUED. 88D
RADAR ESTIMATES SEEM PRETTY GOOD IN THOSE AREAS BASED ON GROUND
TRUTH REPORTS...AND ARE PROBABLY SEEING STORM TOTALS IN THE LAST 48
HOURS APPROACHING OR SLIGHTLY EXCEEDING 5 INCHES IN PARTS OF THESE
AREAS. UPPER LOW IS STILL WELL WEST OF THE AREA...AND LATEST
GUIDANCE SUGGESTS SEVERAL WAVES OF MODERATE TO HEAVY RAIN WITH
EMBEDDED CONVECTION AFFECTING MUCH OF THE REGION THROUGH
06Z...POSSIBLY LONGER IN EASTERN SECTIONS. GIVEN SEVERAL WAVES OF
HEAVY RAINFALL OVER THE LAST WEEK HAVING LOWERED ALREADY LIMITED
ABILITY OF WINTER GROUND TO HANDLE HEAVY RAIN...AND SEVERAL RIVERS
NOW APPROACHING OR FORECAST TO EXCEED FLOOD STAGE OVER PARTS OF THE
AREA...HAVE WENT AHEAD AND EXPANDED THE WATCH TO ENCOMPASS THE
ENTIRE REGION. LATEST NAM AND HRRR GUIDANCE SUGGESTS WIDESPREAD
ADDITIONAL 1 TO 2 INCH RAINFALL OVER THE ENTIRE AREA WITH EMBEDDED
BANDS OF 3 TO 5 INCHES WHERE TRAINING OF HEAVIER SHOWERS/STORMS
OCCURS. /08/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 55 43 54 34 / 100 100 3 0
MERIDIAN 57 47 55 31 / 100 100 8 0
VICKSBURG 55 41 54 32 / 100 94 3 0
HATTIESBURG 62 48 58 35 / 100 100 9 0
NATCHEZ 58 42 54 34 / 100 86 3 0
GREENVILLE 51 41 52 33 / 100 100 4 0
GREENWOOD 51 42 52 31 / 100 100 11 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLOOD WATCH THROUGH MIDNIGHT CST FOR ALL ZONES.
LA...FLOOD WATCH THROUGH MIDNIGHT CST FOR ALL ZONES.
AR...FLOOD WATCH THROUGH MIDNIGHT CST FOR ALL ZONES.
&&
$$
08/JA/15
AREA FORECAST DISCUSSION...UPDATED
NWS JACKSON MS
1005 AM CST MON DEC 26 2011
...PERIODS OF HEAVY RAIN TODAY WITH QUIETER WEATHER WEEK AHEAD...
.UPDATE...RADAR DEPICTS LARGE AREA OF MODERATE TO HEAVY RAIN
COVERING MUCH OF THE FORECAST AREA THIS MORNING. HEAVIEST RAIN WITH
EMBEDDED CONVECTIVE BANDS IS ALONG AND SE OF THE NATCHEZ TRACE
PARKWAY. NONE OF THE MODELS SEEM TO BE DOING A VERY GOOD JOB OF
HANDLING THIS AREA OF HEAVY RAINFALL WITH MODELS SHOWING LIMITED QPF
OVER EASTERN AREAS THROUGH EARLY AFTERNOON...EVEN THE LATEST 12Z
GFS/NAM. WATER VAPOR SHOWS UPPER LOW NEAR KMAF FINALLY MAKING A MOVE
TO THE ESE. DISCOUNTING THE MODEL QPF FORECASTS AND LOOKING AT THE
MASS FIELDS...APPEARS AS THOUGH CURRENT ACTIVITY OVER AREA IS AT
NOSE OF 325+K 850 MB THETA-E AXIS OVER SE LA IN ZONE OF INCREASING
ISENTROPIC ASCENT. WOULD APPEAR AS THOUGH THIS ZONE WILL SHIFT VERY
LITTLE DURING THE DAY AS UPPER LOW BEGINS TO MOVE EAST AND
EVERYTHING ESSENTIALLY WAITS FOR ITS APPROACH. BASED ON THIS WOULD
EXPECT AREAS OF MODERATE TO HEAVY RAIN TO CONTINUE TO DEVELOP AND
FEED ACROSS THE AREA THROUGH THE EVENING HOURS. WOULD ANTICIPATE TWO
MAIN AXES OF HEAVIEST RAIN...ONE OVER THE ARKLAMISS DELTA WHERE A
SWATH OF HEAVIER RAIN SHOULD OCCUR DUE TO THE FORCING ASSOCIATED
DIRECTLY WITH THE UPPER LOW...AND THE OTHER WITH BANDS OF HEAVIER
RAIN AND EMBEDDED CONVECTION OVER THE SOUTHEAST HALF OF THE AREA
ASSOCIATED WITH THE AFOREMENTIONED AXIS OF ISENTROPIC UPGLIDE AND
ELEVATED INSTABILITY. AN ADDITIONAL WIDESPREAD 1 TO 3 INCHES WITH
EMBEDDED HEAVIER TOTALS APPEARS LIKELY OVERALL...WITH ACTIVITY
ENDING FROM THE WEST BETWEEN 03Z AND 09Z TONIGHT AS UPPER SYSTEM
FINALLY SWINGS THROUGH THE AREA.
AS FAR AS FORECAST SPECIFICS...MAIN CHANGE WAS TO ADD HEAVY RAIN TO
THE GRIDS FOR THE ENTIRE AREA TODAY...AND EXPAND TO ALL OF THE EAST
FOR TONIGHT. PREVIOUS EXPANSION TO FFA LOOKS GOOD. TEMPERATURES SEEM
OK FOR NOW. /08/
&&
.AVIATION...MVFR CONDITIONS IN EAST MS WILL SLOWLY DETERIORATE
THROUGH EARLY AFTERNOON LEAVING WIDESPREAD IFR AT ALL TAF SITES AS
AREAS OF STEADY RAIN PERSIST AND INCREASE. THE RISK OF SCATTERED
TSRA WILL ALSO INCREASE THROUGH 06Z TONIGHT PRODUCING OCCASIONAL
LIFR REPORTS BEFORE TAPERING OFF FROM W TO E FROM 08-12Z TUESDAY.
CONDITIONS SHOULD IMPROVE TO MVFR TUESDAY MORNING 14-18Z WITH RAIN
ENDING AND THEN FINALLY VFR CEILINGS RETURNING DURING THE MIDDLE
AFTERNOON. OVERALL SURFACE WINDS WILL PERSIST ESE AT 10-16KTS TODAY
AND BE VARIABLE TONIGHT BEFORE INCREASING FROM THE NW AT 12-18KTS
EARLY TUESDAY MORNING./40/
&&
.HYDROLOGY...SMALL CONVECTIVE COMPLEXES HAVE BEEN AFFECTING PARTS OF
S MS THIS MORNING...WITH A BAND OF 2 TO 4 INCHES OF RAINFALL HAVING
AFFECTED PARTS OF SE MS AND A FFW HAVING BEEN RECENTLY ISSUED. 88D
RADAR ESTIMATES SEEM PRETTY GOOD IN THOSE AREAS BASED ON GROUND
TRUTH REPORTS...AND ARE PROBABLY SEEING STORM TOTALS IN THE LAST 48
HOURS APPROACHING OR SLIGHTLY EXCEEDING 5 INCHES IN PARTS OF THESE
AREAS. UPPER LOW IS STILL WELL WEST OF THE AREA...AND LATEST
GUIDANCE SUGGESTS SEVERAL WAVES OF MODERATE TO HEAVY RAIN WITH
EMBEDDED CONVECTION AFFECTING MUCH OF THE REGION THROUGH
06Z...POSSIBLY LONGER IN EASTERN SECTIONS. GIVEN SEVERAL WAVES OF
HEAVY RAINFALL OVER THE LAST WEEK HAVING LOWERED ALREADY LIMITED
ABILITY OF WINTER GROUND TO HANDLE HEAVY RAIN...AND SEVERAL RIVERS
NOW APPROACHING OR FORECAST TO EXCEED FLOOD STAGE OVER PARTS OF THE
AREA...HAVE WENT AHEAD AND EXPANDED THE WATCH TO ENCOMPASS THE
ENTIRE REGION. LATEST NAM AND HRRR GUIDANCE SUGGESTS WIDESPREAD
ADDITIONAL 1 TO 2 INCH RAINFALL OVER THE ENTIRE AREA WITH EMBEDDED
BANDS OF 3 TO 5 INCHES WHERE TRAINING OF HEAVIER SHOWERS/STORMS
OCCURS. /08/
&&
.PRELIMINARY POINT TEMPS/POPS...
JACKSON 55 43 54 34 / 100 100 3 0
MERIDIAN 57 47 55 31 / 100 100 8 0
VICKSBURG 55 41 54 32 / 100 94 3 0
HATTIESBURG 62 48 58 35 / 100 100 9 0
NATCHEZ 58 42 54 34 / 100 86 3 0
GREENVILLE 51 41 52 33 / 100 100 4 0
GREENWOOD 51 42 52 31 / 100 100 11 0
&&
.JAN WATCHES/WARNINGS/ADVISORIES...
MS...FLOOD WATCH THROUGH MIDNIGHT CST FOR ALL ZONES.
LA...FLOOD WATCH THROUGH MIDNIGHT CST FOR ALL ZONES.
AR...FLOOD WATCH THROUGH MIDNIGHT CST FOR ALL ZONES.
&&
$$
08/JA/15
AREA FORECAST DISCUSSION
NWS ST LOUIS MO
240 PM CST MON DEC 26 2011
.DISCUSSION...
/240 PM CST MON DEC 26 2011/
RAIN IS OVERSPREADING THE AREA FROM THE SOUTH...MORE OR LESS ON TIME
THIS AFTERNOON. HAVE HAD A FEW REPORTS OF A LITTLE SLEET MIXED IN
WITH THE RAIN...BUT THE SLEET IS MELTING VERY QUICKLY AND SHOULD
HAVE NO IMPACT. THE MAIN SLUG OF MOISTURE IS JUST MOVING UP INTO
SOUTHERN MISSOURI FROM ARKANSAS AND LIKELY TO CATEGORICAL POPS STILL
LOOK VERY GOOD FOR MUCH OF EASTERN MISSOURI AND SOUTHERN ILLINOIS.
HOWEVER...LATEST GUIDANCE CONTINUES TO LOOK IFFY FOR MUCH SNOW.
TOP-DOWN METHOD ON BUFKIT SOUNDINGS FROM THE NAM...GFS...LOCAL
WRF...AND THE RUC SHOW THAT BY THE TIME THE LOWER ATMOSPHERE COOLS
ENOUGH TO SUPPORT SNOW...THE TROF WILL BE LIFTING OUT AND AWAY FROM
THE REGION AND DRY AIR WILL BE POURING IN ALOFT. CAN`T ENTIRELY
RULE OUT SNOW SINCE TIMING THE DRY AND COLD AIR WILL BE
CRITICAL...BUT HAVE REDUCED ACCUMULATIONS BELOW 1 INCH...AND HAVE
CHANGED WORDING FROM LIKELY TO CATEGORICAL RAIN/SNOW...TO RAIN AND A
CHANCE OF SNOW.
CARNEY
SRN STORM SYSTEM WILL BE NEARLY BY THE FA BY TUESDAY MORNING...AND
BY THIS TIME...WILL BE AN OPEN WAVE. CONSIDERING HOW THERE IS NOT
MUCH COLD AIR WITH THIS SYSTEM TO BEGIN WITH (N.B. COLD AIR HAS BEEN
HARD TO COME BY SO FAR THIS LATE AUTUMN AND WINTER) AND SFC TEMPS
WILL BE IN THE MID 30S...SNOW AS A GENERAL RULE WILL BE HARD TO COME
BY. MODEL SOUNDINGS FROM ALL GUIDANCE SUGGESTS THIS AS WELL...
ALTHOUGH WBZ VALUES AT ITS LOWEST POINT EARLY TUESDAY MORNING WILL
NOT BE TOO FAR OFF FROM BEING ABLE TO RESULT IN SNOW. SO FOR THIS
REASON...TO INCORPORATE A SMALL AMOUNT OF POTENTIAL MODEL ERROR...
HAVE RETAINED MENTION OF SNOW...BUT AS A MIX WITH RAIN THROUGHOUT
THE CONCLUSION OF THIS EVENT. ANY ADDITIONAL SNOW AMOUNTS TUESDAY
MORNING WILL BE A DUSTING OR LESS AS IT LOOKS AT THIS TIME.
NRN STREAM STORM SYSTEM THAT WILL BE RIGHT ON THE HEELS OF THE SRN
STORM WILL PRODUCE NOTHING MORE THAN SOME ADDITIONAL CLOUDS.
ANOTHER WEAK UPPER LEVEL SYSTEM WILL SLIDE THRU LATE TUESDAY NIGHT
AND WEDNESDAY MORNING BUT WILL CARRY LITTLE MOISTURE WITH IT AND
WILL BE TOO WEAK TO PRODUCE ANY PCPN.
MOS BLENDS LOOK REASONABLE FOR MAX TEMPS TUESDAY AND WEDNESDAY.
WENT AT OR ABOVE THE WARMEST MOS TEMPS FOR MINS WEDNESDAY NIGHT WITH
FAIRLY STOUT SW FLOW THAT SHOULD CARRY INTO A PRETTY MILD DAY ON
THURSDAY AS TEMPS SURGE INTO THE 50S.
A RATHER PROGRESSIVE FLOW WILL DOMINATE THE MEDIUM RANGE FRIDAY THRU
MONDAY AND WILL SIGNAL NO BIG COLD AIR OUTBREAKS (STILL) THRU THE
BEGINNING OF 2012. UPPER LEVEL DISTURBANCES WILL RACE THRU AND EDGE
THE FA LATE FRIDAY AND LATE SATURDAY BUT LIKE THEIR PREDECESSORS
SHOULD BE TOO WEAK TO GENERATE MUCH PCPN THRU SATURDAY. BY EARLY
NEXT WEEK...MOST MODELS TAKE A MUCH STRONGER SYSTEM INTO THE AREA.
THE GFS IS THE EXCEPTION KEEPING THIS SYSTEM WELL TO THE N. HAVE
SLIGHT CHC POPS FOR NOW UNTIL WE CAN GET SOME BETTER RUN-TO-RUN
CONSISTENCY. TEMPS WILL BE AT OR ABOVE AVERAGE THRU THE PERIOD.
TES
&&
.AVIATION...
/1128 AM CST MON DEC 26 2011/
VFR FLIGHT CONDITIONS WILL ACROSS THE AREA FOR MUCH OF THE REST OF
THE AFTERNOON. THERE WILL BE OCCASIONAL SPRINKLES OR LIGHT RAIN
ACROSS PARTS OF SOUTHEAST AND CENTRAL MISSOURI...BUT MOST OF THE
REST OF THE ARE SHOULD REMAIN DRY. CIGS WILL LIKELY DROP BELOW VFR
LATE THIS AFTERNOON/EARLY THIS EVENING ACROSS SOUTHEAST AND EAST
CENTRAL MISSOURI AS WELL AS SOUTHERN ILLINOIS. RAIN WILL BECOME
STEADIER AND HEAVIER...POTENTIALLY MIXING WITH SNOW OVERNIGHT. IFR
CIGS/VSBYS WILL BE LIKELY IN THESE AREAS ESPECIALLY WHERE SNOW
MIXES IN. MOST LIKELY AREAS TO RECEIVE SNOW WILL BE ACROSS THE
EASTERN OZARKS AND SOUTHERN ILLINOIS. SYSTEM WILL BE MOVING RAPIDLY
AWAY FROM THE AREA ON TUESDAY AND LOW CIGS SHOULD CLEAR OUT BY
MID-LATE MORNING. WIND WILL INCREASE FROM THE NORTHWEST...COULD
SEE GUSTS TO 25-30KTS BY 18Z.
SPECIFICS FOR KSTL...VFR FLIGHT CONDITIONS WITH THE POTENTIAL FOR
A FEW SPRINKLES WILL PREVAIL THIS AFTERNOON. EXPECT CIGS TO DROP
RAPIDLY SOMETIME BETWEEN 02Z AND 05Z AS THE STORM SYSTEM TO OUR
SOUTHWEST MOVES INTO THE MISSISSIPPI VALLEY. LATEST MODEL GUIDANCE
IS NOT VERY FAVORABLE FOR MUCH SNOW AT LAMBERT FOR THE DURATION OF
THE STORM...BUT AM RELUCTANT TO PULL ALL MENTION OF SNOW AT THIS
TIME AS MANY INDICATORS ARE VERY CLOSE. SHOULD SEE PRECIP END
BEFORE 12Z TUESDAY WITH INCREASING WINDS FROM THE NORTHWEST BEHIND
THE SYSTEM. WIND MAY GUST UP TO 25-30KTS DURING THE AFTERNOON.
CARNEY
&&
.PRELIMINARY POINT TEMPS/POPS...
ST LOUIS 35 44 28 45 / 90 30 0 0
QUINCY 31 40 26 43 / 30 5 0 0
COLUMBIA 31 44 27 46 / 40 5 0 0
JEFFERSON CITY 32 44 27 46 / 60 5 0 0
SALEM 34 42 24 41 / 100 80 0 0
FARMINGTON 33 44 24 45 / 100 30 0 0
&&
.LSX WATCHES/WARNINGS/ADVISORIES...
MO...NONE.
IL...NONE.
&&
$$
WFO LSX
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
424 PM EST MON DEC 26 2011
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL RAPIDLY MOVE OFF THE EAST COAST
TONIGHT ALLOWING FOR A SOUTHERLY FLOW OF MILDER AIR TO DEVELOP
OVER THE REGION LATER TONIGHT AND TUESDAY. WITH MILDER AIR IN
PLACE...MAINLY RAIN WILL FALL ACROSS THE REGION TUESDAY AFTERNOON
AND EVENING AS A STORM SYSTEM TRACKS NORTHEAST THROUGH
PENNSYLVANIA AND NEW YORK. AFTER THIS STORM PASSES TO THE
NORTHEAST TUESDAY NIGHT COLDER AIR WILL RETURN TO THE REGION
CHANGING THE RAIN TO SNOW AND SNOW SHOWERS. MOST OF THE REGION
WILL SEE LITTLE SNOW ACCUMULATION...EXCEPT FOR NORTH CENTRAL NEW
YORK WHERE A FEW INCHES IS POSSIBLE BY WEDNESDAY AFTERNOON.
&&
.NEAR TERM /THROUGH TUESDAY/...
VIS SATL IMAGERY SHOWS SC LAYER OVER ALL OF C NY AND NE PA. LARGE
SCALE SUBSC BEHIND DEPARTING SHRT WAVE OFF THE NE COAST WILL CONT
TO PUSH INVERSION DOWN AND EVENTUALLY WILL LEAD TO CLRG SKIES
LATE THIS AFTERNOON AND ERLY EVENING. VIS SATL IMAGERY ALREADY
SHOWG THIS IN WRN NY AND NC/NE PA. THE BACK EDGE OF THE SC LAYER
CORRELATED WELL WITH THE 850 MB TEMP GRADIENT WHICH IS INDICATIVE
OF THE SUBSC. USING THE LOCAL WRFARW...THIS GRADIENT MOVES THRU
BTWN 21Z AND 00Z...WHILE THE RUC13 HOLDS ONTO THE COLDER H85 TEMPS
IN EC NY A LITTLE LONGER. IN ANY EVENT BOTH SEEM TO SHOW SIGNS
THAT THIS CLRG WILL TAKE A BIT LONGER IN EC NY...WHERE THERE IS
HIGHER TERRAIN. THIS MAKES SENSE AND WILL HOLD ONTO CLDS A LITTLE
LONGER IN THESE AREAS. REST OF AREA SEES CLRG FOR A TIME THIS
EVENING.
AFTER THE CLDS CLEAR OUT THIS EVENING...HIGHER CLDS FROM THE NEXT
SYSTEM BEGIN TO SPREAD ACROSS NY AND PA. THE SFC RDG AXIS IS E OF
THE REGION TONIGHT AS THE NEXT SYSTEM RAPIDLY APPRCHES FROM THE
SRN PLAINS AND UPR MIDWEST. THE LL FLO WILL TURN SWRLY AND SHUD
KEEP TEMPS FROM BOTTOMING OUT MUCH BELOW 30 MOST PLACES. THE
EXCEPTION IS IN NE PA/SERN NY WHERE THE WINDS WILL REMAIN LIGHT
ENUF WITH CLR SKIES. THUS MINS WILL BE HIGHER IN THE NW CWA LOW
30S AND LOWER IN THE SE CWA MID TO UPPER 20S OR SO.
FOR TUESDAY...CLDS WILL INCREASE THRU THE DAY AS STRG WAA/ISEN
LIFT TAKES PLACE THRU A DEEPER AND DEEPER LAYER AS THE DAY
PROGRESSES. TEMPS FROM THE SFC THRU 850 MB WILL BE WARM ENUF FOR
ALL RAIN ENTIRE CWA. ALL SYNOPTIC SCALE MODELS INDICATE THAT THE
RAIN WILL MOVE IN DURING THE AFTERNOON. WILL RAMP POPS UP BTWN 18Z
TUE AND 00Z WED.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
THE 12Z EURO...18Z NAM...12Z GFS HAVE TRENDED MORE TOWARD THE WEST
WITH THE SFC LO AND ALL INDICATE THAT THE 850 MB LOW TRACKS TO WRN
NY BY 00Z WED. THIS WILL ALLOW 850 MB TEMPS TO CLIMB WELL ABV FRZG
AS THE PRECIP WORKS IN. WITH BNDRY LAYER TEMPS EXPECTED ABV
FRZG...PRECIP WILL BE MAINLY RAIN AT THE ONSET. IN ADDTN...WITH
THIS MORE WRN TRACK...THE DRY SLOT WITH THE DEVELOPING CYCLONE
MOVES RIGHT THRU NE PA AND C NY TUE EVE. COLDER AIR DOES NOT SURGE
IN UNTIL THE BULK OF THE MOISTURE AND LIFT WITH THE STORM IS NE OF
OUR AREA. THUS...IT LOOKS LIKE A RAIN EVENT...POSSIBLY MIXED WITH
SLEET/SNOW FINGER LAKES/UPR MOHAWK/TUG HILL TUE EVE...THEN WRAP
AROUND SNOW AND SNOW SHOWERS ENHANCED BY MOISTURE FROM LAKE
ONTARIO TUE NGT/ERLY WED.
THE SNOW SHOWERS WILL CONT WED IN C NY AS THE WRAP AROUND SNOW
SHOWERS TRANSITIONS TO LAKE EFFECT SNOWS. THE INVERSION RAPIDLY
DROPS DOWN TO 900 MB BY 00Z THU. THUS THERE WILL BE SOME LES...BUT
IT SHUD NOT BE A MAJOR EVENT. MOST OF THE SNOW WILL FALL WED
AM...IN NC NY WITH THE COMBINATION OF LAKE EFFECT AND SYNOPTIC
MOISTURE.
SEE 2-5 INCHES OF SNOW IN NC NY...WITH AN INCH OR LESS SC NY/FAR
NRN PA AND LITTLE IF ANY IN THE REST OF NE PA.
ANOTHER CONCERN IS THE POTENTIAL FOR HIGH WINDS ON WEDNESDAY AS
THE DEEPENING CYCLONE DEPARTS ACRS LWR QUEBEC. MOS GUIDC SUGGESTS
LOW END WIND ADVY CRITERIA. ISALLABORIC PRESSURE RISES ARE RUNNING
CLOSE TO 10 MB/6 HR WHICH IS ALSO BORDERLINE FOR WIND ADVY. SO
WILL HIGHLIGHT IN HWO FOR ENTIRE CWA...AND WILL HIGH POTENTIAL FOR
SOME SNOW IN NC NY AS WELL.
BY WED NGT...LES SNOW SHOWERS AND FLURRIES RAPIDLY COME TO AN END
AS THE LL FLO TURNS MORE WRLY IN ADVANCE OF THE NEXT SYSTEM.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
THE LONG TERM WILL BE DOMINATED BY A BRISK WEST TO EAST FLOW, AS
THE STRONGLY POSITIVE PNA PATTERN RELAXES. THE RESULT WILL BE A
SERIES OF CLIPPERS AND FAST MOVING SYSTEMS TRAVERSING THE GREAT
LAKES AND SOUTHERN ONTARIO PROVINCE.
HOWEVER BY LATE IN THE PERIOD, A JET WILL DIVE INTO THE PLAINS AND
CARVE OUT ANOTHER DEEP TROUGH OVER THE WEST-CENTRAL UNITED STATES.
THIS WILL CAUSE THE POSITIVE PNA PATTERN TO BEGIN TO STRENGTHEN
AGAIN, WITH RISING HEIGHTS INTO THE EASTERN CONUS.
AS A RESULT, WE ARE FORECASTING LOW POP, BRIEF DURATION RW/SW
EVENTS WITH LITTLE ACCUMULATION ANTICIPATED. WE ARE ALSO
FORECASTING TEMPERATURES SLIGHTLY ABOVE NORMAL FOR THE THURSDAY TO
MONDAY PERIOD.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
MODELS ALL SHOW THE CEILING BREAKING UP OVER THE NEXT 3 HOURS AS
DRY AIR UNDERCUTS THE INVERSION. TEMPO MVFR CONDITIONS WILL
PERSIST FOR THE NEXT FEW HOURS AT BGM AND ITH, THEN QUICKLY RISE
TO VFR.
IT WILL BE A QUIET OVERNIGHT WITH LIGHT WINDS AND CIRRUS OVERHEAD.
PRECIPITATION AHEAD OF AN ADVANCING STORM SYSTEM MAY REACH THE AVP
TERMINAL BETWEEN 17Z AND 20Z ON TUESDAY. AT THIS POINT WE ARE NOT
CONFIDENT ENOUGH OF THE ONSET TIME TO PUT IT IN THE CURRENT TAF
PACKAGE. THE 0Z PACKAGE WILL CONTAIN FORECAST PRECIP START TIMES
FOR ALL TERMINALS.
.OUTLOOK...
TUE MORN...VFR.
TUE AFTN/TUE NGT/WED MORN...MVFR IN RAIN DROPPING TO IFR IN SNOW
SHOWERS TUESDAY NIGHT.
WED AFTN/THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...DJP
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS BUFFALO NY
345 PM EST MON DEC 26 2011
.SYNOPSIS...
HIGH PRESSURE CENTERED OVER VIRGINIA THIS EVENING WILL DRIFT OFF THE
MID ATLANTIC COAST OVERNIGHT. A COMPLEX DOUBLE BARRELLED STORM
SYSTEM STRETCHING FROM THE UPPER GREAT LAKES TO THE TENNESSEE VALLEY
WILL THEN DEVELOP A CONSOLIDATED AREA OF LOW PRESSURE OVER
PENNSYLVANIA LATE TUESDAY. THIS STORM SYSTEM IS FORECAST TO LIFT TO
THE SAINT LAWRENCE VALLEY BY WEDNESDAY MORNING. THIS SCENARIO WILL
LEAD TO RAIN AND MIXED PRECIPITATION ACROSS OUR REGION ON TUESDAY...
WITH COLDER AIR ON THE BACKSIDE OF THE STORM CHANGING ALL OF THE
PRECIPITATION TO ACCUMULATING SNOW LATE TUESDAY AND TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH TUESDAY/...
IT WILL BE A VERY PLEASANT EARLY WINTER EVENING ACROSS THE FORECAST
AREA AS SFC HIGH PRESSURE NOSING NORTH FROM VIRGINIA WILL RESULT IN
CLEAR TO PARTLY CLOUDY SKIES. THIS SHOULD ALLOW FOR DECENT VIEWING
OF VENUS IN THE SOUTHWESTERN SKY AND JUPITER TO THE SOUTHEAST. SKIES
WILL BECOME INCREASINGLY CLOUDY DURING THE OVERNIGHT THOUGH...AS
CIRRUS WILL STREAM NORTHWARDS AHEAD OF A PHASING SPLIT UPPER LEVEL
FLOW.
WV IMAGERY FROM LATE IN THE AFTERNOON SHOWS TWO DISTINCT SHORTWAVES
CHUGGING TO THE EAST. THE NORTHERN BRANCH FEATURE WAS OVER THE UPPER
MISSISSIPPI VALLEY WHILE THE SOUTHERN BRANCH VORT CENTER WAS
APPROACHING THE LOWER MISSISSIPPI VALLEY. THE DEVELOPING SOUTHERLY
FLOW BETWEEN THESE TWIN FEATURES AND THE EXITING HIGH PRESSURE WILL
CIRCULATE THE INCREASED MOISTURE NORTHWARDS...WHILE ALSO DEVELOPING
A WARM ADVECTIVE PATTERN. THIS SCENARIO WILL ALSO HELP TO HOLD UP
OUR TEMPERATURES OVERNIGHT...SO THAT INSTEAD OF DROPPING TO OUR LATE
AFTERNOON DEW POINT TEMPS (LOW-MID 20S)...MOST AREAS WILL ONLY
BOTTOM OUT IN THE UPPER 20S TO LOWER 30S. SITES EAST OF LK ONTARIO
WILL BE A BIT COLDER. THESE READINGS WILL BE SOME 10 DEG F ABOVE
SEASONAL NORMALS.
THE TWIN VORTICES WILL CONVERGE ON THE UPPER OHIO VALLEY DURING THE
DAY TUESDAY WHILE LOW PRESSURE WILL CONSOLIDATE IN THE VCNTY OF
EASTERN OHIO AND WESTERN PENNSYLVANIA. WHILE THIS WILL INITIALLY
KEEP A SOUTHERLY WARM ADVECTIVE FLOW OVER ALL OF OUR FORECAST
AREA...THE MID LEVEL WARMTH WILL GET CUT OFF DURING THE COURSE OF
THE AFTERNOON AS THE CIRCULATION ALOFT (THROUGH 10K FT) IS FORECAST
TO CUT OFF OVER THE WRN COUNTIES. THIS WILL COMPLICATE AN ALREADY
TRICKY FORECAST.
THE DYNAMICS IMPOSED BY A DIVERGENT UPPER LEVEL FLOW AND RR QUAD OF
A 130KT H25 JET WILL PROMOTE WIDESPREAD PCPN ACROSS OUR AREA ON
TUESDAY...WITH THE PRECIPITATION LIFTING NORTHEAST AND SPREADING
ACROSS THE WESTERN COUNTIES DURING THE MORNING AND MIDDAY. AREAS
EAST OF LK ONTARIO SHOULD BE PCPN FREE UNTIL EARLY TO MID AFTERNOON.
WHILE SFC TEMPS WILL RANGE FROM THE UPPER 30S TO LOWER 40S ACROSS
MOST OF WESTERN NEW YORK AT THE ONSET OF THE PCPN...THERMAL PROFILES
FROM BOTH THE NAM AND GFS SUGGEST THAT THE COLUMN WILL BE LARGELY
BELOW FREEZING ABOVE 1500 FT. NOT ONLY IS THE BULK OF THE SOUNDING
FORECAST TO BE BELOW FREEZING...BUT THE LOWEST 5K FT WILL LIKELY BE
ISOTHERMAL BETWEEN MINUS 2 AND MINUS 5C. MORE ON THAT IN A MOMENT.
THIS SOMEWHAT UNUSUAL SOUNDING IS DUE TO A RATHER STRANGE SFC STORM
TRACK...THAT TAKES THE SFC LOW FROM NEAR PIT TO ABOUT BGM THEN TO
BTV. SFC STORMS USUALLY TRACK WEST OR EAST OF THE OROGRAPHIC
(ALLEGANY MTNS)...BUT IN THIS CASE THE LOW IS FORECAST TO TRACK
ACROSS THE TOPOGRAPHY. AS MENTIONED EARLIER...THIS WILL CUT OFF THE
MID LEVEL WARMTH FAIRLY EARLY ON IN THE EVENT SO HAVE LEANED TOWARDS
A `COLDER` FORECAST WITH A FASTER CHANGEOVER TO MIXED/SNOW EVENT.
FOR WHAT ITS WORTH...THE SREF PCPN PLUMES FAVOR THIS SOLUTION AND
ARE IN FAIRLY GOOD AGREEMENT WITH THE FORECAST SOUNDINGS FROM THE
OTHER MAJOR GUIDANCE PACKAGES.
QPF FOR TUESDAY WILL RANGE FROM A QUARTER INCH ACROSS THE SRN TIER
TO A LITLE MORE THAN A TENTH ELSEWHERE. THIS IS NOT SIGNIFICANT FOR
THE DAYLIGHT HOURS...ALTHOUGH THE HIGHER TERRAIN OF THE SOUTHERN
TIER COULD PICK UP A WET INCH OR SO OF ACCUMULATION BY NIGHTFALL.
ONE WORRISOME SUBTLETY IN THE FORECAST SOUNDINGS IS THAT A FAIRLY
DEEP MINUS 2 TO MINUS 5 LAYER ISOTHERMAL LAYER WILL PROMOTE MORE
EFFICIENT SNOW MAKING AS AGGREGATION IN THE LOW LEVELS COULD BE
SIGNIFICANT.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY/...
DEEPENING LOW PRESSURE TRACKING ACROSS NEW ENGLAND WILL BRING IN
COLDER AIR TUESDAY NIGHT...WHICH WILL CHANGE PRECIPITATION OVER TO
SNOW. THIS WILL LIKELY BRING ACCUMULATING SNOW TO ALL OF WESTERN NEW
YORK...WITH THE POSSIBILITY OF MORE SIGNIFICANT (6 INCHES OR GREATER
OF SNOW) ACROSS THE SOUTHERN TIER...AND EAST OF LAKE ONTARIO. MUCH
COLDER AIR WILL MOVE IN WEDNESDAY...WITH LINGERING LAKE EFFECT SNOW
SHOWERS SE OF LAKE ONTARIO...AND BLUSTERY CONDITIONS DURING THE
DAY...WITH WITH HIGHS ON WEDNESDAY ONLY IN THE LOWER 20S ACROSS MUCH
OF THE REGION.
FOR THE DETAILS...MODEL AGREEMENT HAS IMPROVED WITH THE 12Z
RUNS...WITH GENERALLY A FAIRLY TIGHT CLUSTER OF SOLUTIONS AMONG THE
MODELS CONSULTED. THE BIGGEST MATERIAL DIFFERENCE AMONG MODELS IS HOW
QUICKLY THE LOW DEEPENS...WITH THE 12Z NAM TRENDING SLOWER THAN MOST
OTHER MODELS. USING A CONSENSUS OF THE 12Z RUNS OF THE
NAM/RGEM/GFS/UKMET/EUROPEAN/SREF PUTTING 985 MB SURFACE LOW ALONG
THE MAINE/QUEBEC BORDER AT 12Z WEDNESDAY. DESPITE THE FAIRLY GOOD
MODEL AGREEMENT...THE CHALLENGE IN THIS EVENT IS THE DETAILS. BUT
TUESDAY NIGHT...FORECAST SOUNDINGS WILL BE MARGINAL FOR SNOW IN FAR
WESTERN SECTIONS...AND IN JEFFERSON/LEWIS COUNTIES. RAIN/SNOW WILL
DEPEND ON SUBTLE DIFFERENCES IN SURFACE TEMPERATURE...WHERE HIGHER
ELEVATIONS WILL LIKELY CHANGEOVER FIRST.
LATE TUESDAY NIGHT...A STRONG PSEUDO-ARCTIC BOUNDARY WILL SWEEP
ACROSS AS THE LOW INTENSIFIES IN EASTERN QUEBEC. COLD AIR WITH THIS
WILL DEFINITELY CHANGE PRECIPITATION OVER TO SNOW...AND IT IS THIS
FEATURE WHICH WILL LIKELY BRING AN INCH OR TWO ACROSS THE REGION.
ON WEDNESDAY...THIS ARCTIC BOUNDARY WILL CONTINUE TO PUSH TO THE
EAST OF REGION...USHERING IN COLD DAYTIME TEMPS. WITH THE UPPER TROF
STILL BACK ACROSS THE REGION...EXPECT THIS WILL SET UP A BRIEF
PERIOD OF LAKE ENHANCED SNOW SE OF LAKE ONTARIO...WAYNE COUNTY
EASTWARD. WINDS WILL BE A BIT ON THE STRONG SIDE...BUT WITH RAPID
COOLING...LAKE INDUCED INSTABILITY WILL INCREASE TO AROUND 300 J/KG.
AS THE SHORTWAVE EXITS...THIS SHOULD DRY THE AIR OUT...ALLOWING LAKE
SNOWS TO TAPER OFF.
A WINTER STORM WATCH WAS CONSIDERED...BUT ULTIMATELY CONFIDENCE IS
NOT QUITE HIGH ENOUGH FOR THE HEADLINE. SNOW AMOUNTS ARE MARGINAL TO
SUPPORT THE HEADLINE...AND WITH THE SEVERAL CLOSE CALLS WITH THIS
SYSTEM...FROM THE MARGINALLY COLD AIR MASS AT THE ONSET...TO THE
FRONTAL BOUNDARY SNOW SHOWERS...TO THE POSSIBLE LAKE ENHANCEMENT AT
THE END. BECAUSE OF THIS...WILL HOLD OFF ON ANY HEADLINES AND
CONTINUE A MENTION IN THE HWO. FOR THOSE INTERESTED IN SNOW
AMOUNTS...EXPECT MOST LOCATIONS TO BE IN THE 1 TO 3 INCH RANGE. THE
EXCEPTIONS ARE WESTERN PORTIONS OF THE SOUTHERN TIER...AND E-SE OF
LAKE ONTARIO...ROUGHLY INCLUDING WAYNE/N
CAYUGA/OSWEGO/JEFFERSON/LEWIS COUNTIES...WHERE 4 INCHES OR GREATER
OF SNOW ARE LIKELY. DEPENDING ON HOW SEVERAL FACTORS WORK
OUT...COULD SEE AMOUNTS TO 8 INCHES IN SOME OF THESE
LOCATIONS...HOWEVER AMOUNTS THIS HIGH ARE ONLY A POSSIBILITY AT THIS
TIME.
THERE WILL BE OTHER IMPACTS WITH THIS SYSTEM. THE FRONTAL BOUNDARY
WILL CAUSE TEMPERATURES TO DROP QUITE RAPIDLY EARLY WEDNESDAY
MORNING. THIS MAY CAUSE ANY WATER OR SLUSH ON ROADWAYS TO
FREEZE...POTENTIALLY MAKING FOR A SLICK COMMUTE WEDNESDAY MORNING.
ALSO...THE TIMING OF THE FRONTAL BOUNDARY WILL BE KEY...AS EVEN AN
INCH OR TWO OF SNOW CAN BE A NUISANCE...IF IT COMES QUICKLY AND NEAR
RUSH HOUR.
&&
.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
HIGH PRESSURE WILL BRIEFLY RIDGE ACROSS THE REGION WEDNESDAY NIGHT.
THERE MAY BE SOME LINGERING LAKE EFFECT SNOW SHOWERS EAST OF LAKE
ONTARIO...WITH THIS TO END AS WINDS SHIFT TO THE SW LATE IN THE
NIGHT.
THE THURSDAY THROUGH SUNDAY PERIOD WILL FEATURE A ZONAL FLOW...WITH
A COUPLE OF CLIPPERS FORECAST TO CROSS THE REGION. THE 12Z
GFS/EUROPEAN/GGEM DIFFER ON THE TIMING OF THESE FAST SYSTEM...MAKING
POPS DIFFICULT TO BE TOO SPECIFIC. ALSO...TEMPERATURES WILL BE
MARGINAL FOR LAKE EFFECT AHEAD OF THE CLIPPER. THE RESULT WILL BE
ONLY MODEST LEVELS OF INSTABILITY...AND TEMPERATURES WILL AT TIMES
BE MARGINALLY COLD ENOUGH FOR SNOW...WITH SOME RAIN POSSIBLE. GIVEN
THE MARGINALLY COLD 850MB TEMPS...DO NOT EXPECT ANY MAJOR EVENTS
FROM THESE CLIPPERS...BUT IT WILL BE HARD TO RULE OUT A RAIN OR SNOW
SHOWER DURING THIS PERIOD...EVEN IF THE MAJORITY OF THE TIME WILL BE
DRY. A STALLED FRONTAL BOUNDARY WILL BE CLOSE TO THE EASTERN LAKE
ONTARIO REGION...SO AS THIS FLUCTUATES WITH THE SYSTEMS...IT MAY BE
MARKEDLY COLDER THERE AT TIMES.
ON MONDAY...THE EUROPEAN LIFTS LOW PRESSURE ACROSS THE REGION...WITH
THE GFS/GGEM SHOWING MORE OF A RIDGE. NO STRONG FEELINGS EITHER WAY
ON THIS...AND WILL SIMPLY MAINTAIN CHANCE POPS.
&&
.AVIATION /21Z MONDAY THROUGH SATURDAY/...
VFR CONDITIONS WILL BE IN PLACE TONIGHT INTO AT LEAST THE FIRST
HALF OF TUESDAY...DESPITE AN INCREASE IN HIGH AND MID LEVEL
MOISTURE. THE INCREASED CLOUD COVER WILL BE DUE A DEVELOPING AREA
OF LOW PRESSURE OVER THE UPPER OHIO VALLEY.
CLOUDS FROM THIS STORM SYSTEM WILL LOWER AND THICKEN DURING THE
MIDDAY AND AND AFTERNOON THURSDAY...WITH RAIN (MIXED PCPN HIGHER
ELEVATIONS) LIFTING FROM THE SOUTHWEST CORNER OF THE STATE TO THE
EASTERN LAKE ONTARIO REGION IN THE PROCESS. CIGS BY LATE AFTERNOON
WILL RANGE FROM IFR ACROSS THE WESTERN COUNTIES TO MVFR NEAR KART
AND KGTB.
OUTLOOK...
TUESDAY NIGHT...IFR WITH WIDESPREAD RAIN CHANGING TO WET SNOW.
WEDNESDAY...MVFR WITH MORNING SNOW SHOWERS IMPROVING TO VFR.
THURSDAY...MAINLY VFR.
THURSDAY NIGHT AND FRIDAY...MVFR WITH A CHANCE OF RAIN AND SNOW
SHOWERS.
SATURDAY...VFR.
&&
.MARINE...
HIGH PRESSURE NOSING NORTH FROM VIRGINIA WILL KEEP MODERATE TO FRESH
SOUTHWESTERLIES ACROSS LAKE ERIE AND EASTERN LAKE ONTARIO THROUGH
THIS EVENING SO SMALL CRAFT ADVISORIES WILL REMAIN IN EFFECT FOR
THOSE NEARSHORE WATERS. AS THE NIGHT PROGRESSES...THE FLOW WILL BACK
TO THE SOUTH AND WEAKEN. THIS WILL ALLOW WAVES TO SUBSIDE A BIT
WHILE MORE IMPORTANTLY PUSHING THE HIGHEST WAVES TO CANADIAN WATERS.
A STORM SYSTEM WILL DEVELOP OVER THE MID WEST ON TUESDAY AND
APPROACH THE LOWER GREAT LAKES DURING THE AFTERNOON AND EVENING. THIS
WILL ACTUALLY WEAKEN THE SFC PRESSURE GRADIENT IN THIS CASE SO THAT
WINDS AND WAVES SHOULD BE BELOW SCA CRITERIA. AS THE SYSTEM MOVES TO
THE SAINT LAWRENCE VALLEY AND STRENGTHENS TUESDAY NIGHT...STRONG
NORTHWEST WINDS WILL DEVELOP ACROSS LAKE ERIE...AND BY DAYBREAK
WEDNESDAY...ACROSS LAKE ONTARIO. DEFINITE SCA CONDITIONS WILL BE IN
PLACE AT THAT TIME...WITH THE THREAT OF GALE FORCE WINDS.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 7 PM EST THIS EVENING FOR LEZ040-
041.
SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
LOZ043-044.
SMALL CRAFT ADVISORY UNTIL 4 AM EST TUESDAY FOR LOZ045.
&&
$$
SYNOPSIS...RSH
NEAR TERM...RSH
SHORT TERM...APFFEL
LONG TERM...APFFEL
AVIATION...RSH
MARINE...RSH
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
343 PM EST MON DEC 26 2011
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL RAPIDLY MOVE OFF THE EAST COAST
TONIGHT ALLOWING FOR A SOUTHERLY FLOW OF MILDER AIR TO DEVELOP
OVER THE REGION LATER TONIGHT AND TUESDAY. WITH MILDER AIR IN
PLACE...MAINLY RAIN WILL FALL ACROSS THE REGION TUESDAY AFTERNOON
AND EVENING AS A STORM SYSTEM TRACKS NORTHEAST THROUGH
PENNSYLVANIA AND NEW YORK. AFTER THIS STORM PASSES TO THE
NORTHEAST TUESDAY NIGHT COLDER AIR WILL RETURN TO THE REGION
CHANGING THE RAIN TO SNOW AND SNOW SHOWERS. MOST OF THE REGION
WILL SEE LITTLE SNOW ACCUMULATION...EXCEPT FOR NORTH CENTRAL NEW
YORK WHERE A FEW INCHES IS POSSIBLE BY WEDNESDAY AFTERNOON.
&&
.NEAR TERM /THROUGH TUESDAY/...
VIS SATL IMAGERY SHOWS SC LAYER OVER ALL OF C NY AND NE PA. LARGE
SCALE SUBSC BEHIND DEPARTING SHRT WAVE OFF THE NE COAST WILL CONT
TO PUSH INVERSION DOWN AND EVENTUALLY WILL LEAD TO CLRG SKIES
LATE THIS AFTERNOON AND ERLY EVENING. VIS SATL IMAGERY ALREADY
SHOWG THIS IN WRN NY AND NC/NE PA. THE BACK EDGE OF THE SC LAYER
CORRELATED WELL WITH THE 850 MB TEMP GRADIENT WHICH IS INDICATIVE
OF THE SUBSC. USING THE LOCAL WRFARW...THIS GRADIENT MOVES THRU
BTWN 21Z AND 00Z...WHILE THE RUC13 HOLDS ONTO THE COLDER H85 TEMPS
IN EC NY A LITTLE LONGER. IN ANY EVENT BOTH SEEM TO SHOW SIGNS
THAT THIS CLRG WILL TAKE A BIT LONGER IN EC NY...WHERE THERE IS
HIGHER TERRAIN. THIS MAKES SENSE AND WILL HOLD ONTO CLDS A LITTLE
LONGER IN THESE AREAS. REST OF AREA SEES CLRG FOR A TIME THIS
EVENING.
AFTER THE CLDS CLEAR OUT THIS EVENING...HIGHER CLDS FROM THE NEXT
SYSTEM BEGIN TO SPREAD ACROSS NY AND PA. THE SFC RDG AXIS IS E OF
THE REGION TONIGHT AS THE NEXT SYSTEM RAPIDLY APPRCHES FROM THE
SRN PLAINS AND UPR MIDWEST. THE LL FLO WILL TURN SWRLY AND SHUD
KEEP TEMPS FROM BOTTOMING OUT MUCH BELOW 30 MOST PLACES. THE
EXCEPTION IS IN NE PA/SERN NY WHERE THE WINDS WILL REMAIN LIGHT
ENUF WITH CLR SKIES. THUS MINS WILL BE HIGHER IN THE NW CWA LOW
30S AND LOWER IN THE SE CWA MID TO UPPER 20S OR SO.
FOR TUESDAY...CLDS WILL INCREASE THRU THE DAY AS STRG WAA/ISEN
LIFT TAKES PLACE THRU A DEEPER AND DEEPER LAYER AS THE DAY
PROGRESSES. TEMPS FROM THE SFC THRU 850 MB WILL BE WARM ENUF FOR
ALL RAIN ENTIRE CWA. ALL SYNOPTIC SCALE MODELS INDICATE THAT THE
RAIN WILL MOVE IN DURING THE AFTERNOON. WILL RAMP POPS UP BTWN 18Z
TUE AND 00Z WED.
&&
.SHORT TERM /TUESDAY NIGHT THROUGH WEDNESDAY NIGHT/...
THE 12Z EURO...18Z NAM...12Z GFS HAVE TRENDED MORE TOWARD THE WEST
WITH THE SFC LO AND ALL INDICATE THAT THE 850 MB LOW TRACKS TO WRN
NY BY 00Z WED. THIS WILL ALLOW 850 MB TEMPS TO CLIMB WELL ABV FRZG
AS THE PRECIP WORKS IN. WITH BNDRY LAYER TEMPS EXPECTED ABV
FRZG...PRECIP WILL BE MAINLY RAIN AT THE ONSET. IN ADDTN...WITH
THIS MORE WRN TRACK...THE DRY SLOT WITH THE DEVELOPING CYCLONE
MOVES RIGHT THRU NE PA AND C NY TUE EVE. COLDER AIR DOES NOT SURGE
IN UNTIL THE BULK OF THE MOISTURE AND LIFT WITH THE STORM IS NE OF
OUR AREA. THUS...IT LOOKS LIKE A RAIN EVENT...POSSIBLY MIXED WITH
SLEET/SNOW FINGER LAKES/UPR MOHAWK/TUG HILL TUE EVE...THEN WRAP
AROUND SNOW AND SNOW SHOWERS ENHANCED BY MOISTURE FROM LAKE
ONTARIO TUE NGT/ERLY WED.
THE SNOW SHOWERS WILL CONT WED IN C NY AS THE WRAP AROUND SNOW
SHOWERS TRANSITIONS TO LAKE EFFECT SNOWS. THE INVERSION RAPIDLY
DROPS DOWN TO 900 MB BY 00Z THU. THUS THERE WILL BE SOME LES...BUT
IT SHUD NOT BE A MAJOR EVENT. MOST OF THE SNOW WILL FALL WED
AM...IN NC NY WITH THE COMBINATION OF LAKE EFFECT AND SYNOPTIC
MOISTURE.
SEE 2-5 INCHES OF SNOW IN NC NY...WITH AN INCH OR LESS SC NY/FAR
NRN PA AND LITTLE IF ANY IN THE REST OF NE PA.
ANOTHER CONCERN IS THE POTENTIAL FOR HIGH WINDS ON WEDNESDAY AS
THE DEEPENING CYCLONE DEPARTS ACRS LWR QUEBEC. MOS GUIDC SUGGESTS
LOW END WIND ADVY CRITERIA. ISALLABORIC PRESSURE RISES ARE RUNNING
CLOSE TO 10 MB/6 HR WHICH IS ALSO BORDERLINE FOR WIND ADVY. SO
WILL HIGHLIGHT IN HWO FOR ENTIRE CWA...AND WILL HIGH POTENTIAL FOR
SOME SNOW IN NC NY AS WELL.
BY WED NGT...LES SNOW SHOWERS AND FLURRIES RAPIDLY COME TO AN END
AS THE LL FLO TURNS MORE WRLY IN ADVANCE OF THE NEXT SYSTEM.
&&
.LONG TERM /THURSDAY THROUGH MONDAY/...
330 AM UPDATE...
LITTLE CHANGE. UNSETTLED WITH MULTIPLE STORMS. LAKE EFFECT
THURSDAY. A STORM FROM THE WEST FRIDAY FOLLOWED BY ANOTHER
SATURDAY THEN A THIRD ON MONDAY. COULD BE MIXED PRECIP ACROSS NE
PA AND SULLIVAN NY WITH 850MB TEMPS JUST BELOW ZERO AND
THICKNESSES ALSO ON THE EDGE. GIVEN WEST TO EAST STORM TRACK AND
LACK OF COLD AIR NOT EXPECTING ANY BIG SNOW STORMS.
4 PM SUNDAY UPDATE...
MODELS IN AGREEMENT FOR WEDNESDAY NIGHT, WITH HIGH PRESSURE OVER THE
AREA AND GENERALLY QUIET WEATHER UNTIL EARLY FRIDAY MORNING. THE
EXCEPTION MAY BE SOME WEAK LES WEDNESDAY NIGHT.
BY FRIDAY MORNING THE MODELS BEGIN TO DISAGREE. IT SEEMS AS THOUGH
TIMING MAY BE THE LARGER ISSUE. BY 12Z FRIDAY, THE GFS HAS A SFC
LOW OVER LAKE MICHIGAN, WITH PRECIP WELL OUT TO THE EAST. THE
ECMWF HAS TWO SEPARATE LOWS. ONE OVER THE GEORGIA BAY AND ONE OVER
SOUTH DAKOTA. BOTH ARE MUCH WEAKER THAN THE LOW IN THE GFS. BY 00Z
SAT THE GFS HAS THE LOW JUST TO THE NORTH OF LAKE ONTARIO AND THE
ECMWF KICKS OUT THE INITIAL LOW AND HAS THE SECOND LOW ABOUT THE
SAME PLACE THE GFS HAD THE LOW 12 HOURS EARLIER. THE ECMWF HAS THE
LOW TAKING NEARLY THE SAME TRACK AS THE GFS, JUST ABOUT 12 HOURS
BEHIND. BOTH HAVE HIGH PRESSURE BUILDING IN FOR SUNDAY.
GIVEN THE TIMING DIFFERENCES AND HOW FAR OUT THIS SYSTEM IS, WILL
KEEP CHC POPS IN THE FORECAST FROM FRIDAY THROUGH SATURDAY.
LOOKING AT THE AIR MASS TEMPS, IT DOES LOOK AS THOUGH IT SHOULD BE
COLD ENOUGH TO SUPPORT ALL SNOW WITH THIS SYSTEM.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
MODELS ALL SHOW THE CEILING BREAKING UP OVER THE NEXT 3 HOURS AS
DRY AIR UNDERCUTS THE INVERSION. TEMPO MVFR CONDITIONS WILL
PERSIST FOR THE NEXT FEW HOURS AT BGM AND ITH, THEN QUICKLY RISE
TO VFR.
IT WILL BE A QUIET OVERNIGHT WITH LIGHT WINDS AND CIRRUS OVERHEAD.
PRECIPITATION AHEAD OF AN ADVANCING STORM SYSTEM MAY REACH THE AVP
TERMINAL BETWEEN 17Z AND 20Z ON TUESDAY. AT THIS POINT WE ARE NOT
CONFIDENT ENOUGH OF THE ONSET TIME TO PUT IT IN THE CURRENT TAF
PACKAGE. THE 0Z PACKAGE WILL CONTAIN FORECAST PRECIP START TIMES
FOR ALL TERMINALS.
.OUTLOOK...
TUE MORN...VFR.
TUE AFTN/TUE NGT/WED MORN...MVFR IN RAIN DROPPING TO IFR IN SNOW
SHOWERS TUESDAY NIGHT.
WED AFTN/THU...VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...DJN
NEAR TERM...DJN
SHORT TERM...DJN
LONG TERM...SLI/TAC
AVIATION...DJP
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
241 PM EST MON DEC 26 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...THEN MOVE OFFSHORE
TONIGHT. A COMPLEX LOW PRESSURE SYSTEM WILL APPROACH THE AREA FROM
THE SOUTHWEST TUESDAY. THE LOW WILL PASS NORTH OF THE AREA TUESDAY
EVENING WHILE SWINGING A COLD FRONT THROUGH THE REGION TUESDAY
NIGHT. HIGH PRESSURE BUILDS OVER THE AREA WEDNESDAY THROUGH THE END
OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 130 PM MON...RIDGING CONTINUES TO MOVE EAST ACROSS THE
REGION...ACTING TO VEER WINDS MORE NORTHEASTERLY AS THE AFTERNOON
PROGRESSES. SITES ACROSS THE COASTAL PLAIN ARE CURRENTLY GUSTING
TO 15-20 KNOTS...WHICH IS EXPECTED TO CONTINUE THROUGHOUT THE REST
OF THE AFTERNOON. VIS/WV SATELLITE AND FORECAST SOUNDINGS
ILLUSTRATE VERY DRY AIRMASS ALOFT SO EXPECT SUNNY SKIES TO PREVAIL
WITH A FEW HIGH CIRRUS POSSIBLE ACROSS SOUTHERN PORTIONS LATE
TODAY. LOW LEVEL THICKNESSES REMAIN LOWER TODAY...WITH 1000-850
MB THICKNESSES EXPECTED IN THE 1325-1330 METER RANGE. NO
SIGNIFICANT CHANGES NEEDED FOR THE NEAR TERM FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 300 AM MONDAY...WINDS WILL DIMINISH TONIGHT AS HIGH PRES MOVES
ACROSS. DON`T EXPECT MUCH IN THE WAY OF CLOUDS UNTIL LATE
SO WITH DRY AMS IN PLACE EXPECT GOOD RADIATIONAL COOLING WITH MIN
TEMPS FROM THE LOWER 30S INLAND TO AROUND 40 ON THE COAST.
&&
.LONG TERM /TUESDAY THROUGH MONDAY/...
AS OF 240 PM MONDAY...WIDESPREAD HEAVY SHOWERS/POSSIBLE STRONG
THUNDERSTORMS WILL BE MOVING OFF OF THE COAST A LITTLE AFTER 00Z
TUESDAY EVENING. STRONG GRADIENT WINDS WILL BE ASSOCIATED WITH THE
FRONT AND WIND ADVISORY CONDITIONS WILL BE POSSIBLE ALONG THE
IMMEDIATE COAST THROUGH EARLY WEDNESDAY. ALTHOUGH THE BULK OF THE
RAINFALL WILL BE OVER AROUND 00Z...THE STRONG MID LEVEL SHORTWAVE
WILL NOT CROSS THE AREA UNTIL AFTER MIDNIGHT SO THE THREAT FOR
SHOWERS WILL PERSIST THROUGH ABOUT 06Z WEDNESDAY. EASTERN NC WILL
RECEIVE SOME MUCH NEEDED RAINFALL WITH AMOUNTS OF 0.50"-0.75"
EXPECTED MOST AREAS WITH LOCAL AMOUNTS IN EXCESS OF 1 INCH POSSIBLE.
LOW TEMPERATURES WILL RANGE FROM THE UPPER 30S INLAND TO THE MIDDLE
40S COAST.
THE UPPER LEVEL FLOW WILL BECOME MORE ZONAL AND VERY FAST THROUGH
THE MID TO LATE WEEK TIME FRAME...CUTTING OFF ANY GULF OF MEXICO
INFLOW...WITH SEVERAL DRY NORTHERN STREAM SHORT WAVES PROMPTING A
SERIES DRY COLD FRONTAL PASSAGES ACROSS THE AREA THURSDAY
NIGHT...SATURDAY AND SUNDAY NIGHT. NEAR SEASONABLE TEMPERATURES ARE
EXPECTED ACROSS THE REGION THROUGH THE PERIOD.
&&
.AVIATION /20Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TUESDAY/...
AS OF 130 PM MON...HIGH PRESSURE WILL REMAIN IN CONTROL OF THE
SENSIBLE WEATHER THROUGH THIS EVENING...AHEAD OF AN APPROACHING
COMPLEX LOW PRESSURE SYSTEM THAT WILL IMPACT THE REGION LATE
TONIGHT THROUGH TUESDAY. NORTHERLY WINDS HAVE BECOME NORTHEASTERLY
THIS AFTERNOON GUSTING UPWARDS OF 20 KNOTS DUE IN PART TO
EXCELLENT MIXING AND STRONG CAA ACROSS THE REGION. VERY DRY ATMOS
IN PLACE SO DO NOT EXPECT STRATOCUMULUS DEVELOPMENT THIS
AFTERNOON. MID/HIGH CLOUDS DO NOT BEGIN IMPACTING WESTERN TAF
SITES/ISO/OAJ/PGV UNTIL NEAR SUNRISE TUES MORNING. WINDS WILL
CONTINUE VEERING OVERNIGHT...TO A MORE SOUTHEASTERLY RETURN FLOW
BY SUNRISE. OVERALL DRY ATMOS AND WINDS AROUND 4-6 KT OVERNIGHT
SHOULD INHIBIT ANY FOG FORMATION...THUS EXPECT VFR CONDITIONS
OVERNIGHT AS WELL.
PRECIP WILL BEGIN TO OVERSPREAD THE REGION FROM WEST TO EAST TUES.
A WARM FRONT WILL LIFT THROUGH THE REGION EARLY TUES
MORNING...SHELTERING IN DEWPOINTS IN THE UPPER 50S TO LOWER 60S.
WINDS WILL VEER FURTHER...EVENTUALLY BECOMING SOUTHWEST 15-20
KNOTS WITH SOME 25-30 KNOT GUSTS. LOW LEVEL JET OF 25-30 KNOTS
JUST OFF THE SURFACE TO 60-70 KNOTS AT 850MB WILL LEAD TO LOW
LEVEL WIND SHEAR CONCERNS. THE FRONT WILL EXIT OFF THE COAST LATE
TUES EVENING WITH CLEARING SKIES AND IMPROVING CONDITIONS FROM
WEST TO EAST. EXPECT MVFR IN LOWERED CEILINGS AND VISIBILITIES
FROM ABOUT 15Z TUES TO 06Z WED...WITH ISOLATED IFR/LIFR POSSIBLE
IN HEAVIER SHOWERS.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 230 PM MONDAY...SUB-VFR CONDITIONS ARE LIKELY TUESDAY NIGHT.
ALTHOUGH THE STRONG COLD FRONT AND THE BULK OF THE MOISTURE WILL
MOVE OFF OF THE COAST IN THE EARLY EVENING...THE STRONG MID LEVEL
SHORTWAVE WILL NOT CROSS THE AREA UNTIL AFTER MIDNIGHT. LOW CLOUDS
AND LIGHT SHOWERS WILL BE POSSIBLE UNTIL AFTER THE SHORTWAVE PASSES.
PREVAILING VFR CONDITIONS ARE THEN EXPECTED WEDNESDAY THROUGH
SATURDAY AS A PREDOMINATELY DRY WESTERLY FLOW PREVAILS ACROSS
EASTERN NC.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1010 AM MON...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
SMALL CRAFT CONDITIONS ACROSS THE COASTAL WATERS. NORTHWEST TO
NORTH-NORTHWEST WINDS 20-25 KNOTS WITH GUSTS NEAR 30 KNOTS HAVE
BEEN OBSERVED ACROSS THE NORTHERN COASTAL WATERS...WITH 20 KNOTS
GUSTING TO 25 KNOTS ELSEWHERE. SEAS HAVE BUILT TO 5 TO 7 FT OFF
DUCK BUT EXPECT SEAS 6-8 FT FARTHER OFFSHORE. GIVEN CURRENT
SCENARIO AND LATEST 12Z NAM/14Z RUC GUIDANCE...HAVE EXTENDED THE
SCAS FOR THE SOUTHERN COASTAL WATERS UNTIL NOON...THE PAMLICO AND
ALBEMARLE SOUNDS UNTIL 2PM...AND THE CENTRAL WATERS REMAIN THROUGH
LATE THIS EVENING.
HIGH PRESSURE WILL CONTINUE TO MIGRATE EAST ACROSS THE WATERS
TODAY. THE RIDGE WILL CREST ACROSS THE WATERS OVERNIGHT...ALLOWING
WINDS TO VEER FURTHER...BECOMING EAST LATE AND DIMINISHING 10-15
KNOTS...THEN SOUTHEAST BY SUNRISE TUES. SEAS WILL DIMINISH BELOW
SCA LEVELS LATER THIS EVENING AS WELL.
LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
AS OF 240 PM MONDAY...THE STRONG COLD FRONT WILL CROSS THE NC WATERS
TUESDAY EVENING WITH STRONG SMALL CRAFT ADVISORY CONDITIONS/POSSIBLE
MARGINAL GALES EXPECTED...ESPECIALLY OVER THE CENTRAL WATERS. SEAS
WILL PEAK AROUND 13 FT IN THE EVENING. WINDS WILL DIMINISH AND SEAS
WILL SUBSIDE VERY LATE WEDNESDAY (AFTER 18Z) AS LOW LEVEL COLD
ADVECTION WANES AND HIGH PRESSURE BUILDS OVER THE WATERS. LIGHTER
NORTHWEST TO WEST WINDS 15 KT OR LESS ARE EXPECTED WEDNESDAY NIGHT
AND THURSDAY AS HIGH PRESSURE CRESTS OVER THE WATERS. WESTERLY FLOW
INCREASES TO 20 TO 25 KT THURSDAY NIGHT AND FRIDAY PRODUCING
MARGINAL SMALL CRAFT ADVISORY CONDITIONS AS A DRY COLD FRONT CROSSES
THE WATERS. WILL FORECAST IMPROVING CONDITIONS ON SATURDAY.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR AMZ150-
152-154.
&&
$$
SYNOPSIS...DAG
NEAR TERM...DAG
SHORT TERM...JAC
LONG TERM...JME
AVIATION...JME/DAG
MARINE...JME/DAG
AREA FORECAST DISCUSSION...UPDATED
NWS NEWPORT/MOREHEAD CITY NC
137 PM EST MON DEC 26 2011
.SYNOPSIS...
HIGH PRESSURE WILL BUILD IN FROM THE WEST TODAY...THEN MOVE OFFSHORE
TONIGHT. A COMPLEX LOW PRESSURE SYSTEM WILL APPROACH THE AREA FROM
THE SOUTHWEST TUESDAY. THE LOW WILL PASS NORTH OF THE AREA TUESDAY
EVENING WHILE SWINGING A COLD FRONT THROUGH THE REGION TUESDAY
NIGHT. HIGH PRESSURE BUILDS OVER THE AREA WEDNESDAY THROUGH THE END
OF THE WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 130 PM MON...RIDGING CONTINUES TO MOVE EAST ACROSS THE
REGION...ACTING TO VEER WINDS MORE NORTHEASTERLY AS THE AFTERNOON
PROGRESSES. SITES ACROSS THE COASTAL PLAIN ARE CURRENTLY GUSTING
TO 15-20 KNOTS...WHICH IS EXPECTED TO CONTINUE THROUGHOUT THE REST
OF THE AFTERNOON. VIS/WV SATELLITE AND FORECAST SOUNDINGS
ILLUSTRATE VERY DRY AIRMASS ALOFT SO EXPECT SUNNY SKIES TO PREVAIL
...WITH A FEW HIGH CIRRUS POSSIBLE ACROSS SOUTHERN PORTIONS LATE
TODAY. LOW LEVEL THICKNESSES REMAIN LOWER TODAY...WITH 1000-850
MB THICKNESSES EXPECTED IN THE 1325-1330 METER RANGE. NO
SIGNIFICANT CHANGES NEEDED FOR THE NEAR TERM FORECAST.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM TUESDAY/...
AS OF 300 AM MONDAY...WINDS WILL DIMINISH TONIGHT AS HIGH PRES MOVES
ACROSS. DON`T EXPECT MUCH IN THE WAY OF CLOUDS UNTIL LATE
SO WITH DRY AMS IN PLACE EXPECT GOOD RADIATIONAL COOLING WITH MIN
TEMPS FROM THE LOWER 30S INLAND TO AROUND 40 ON THE COAST.
&&
.LONG TERM /TUESDAY THROUGH SUNDAY/...
AS OF 315 AM MONDAY...MODELS CONTINUE TO INDICATE MOST SIGNIFICANT
WEATHER DURING PERIOD WILL OCCUR TUE AND TUE NIGHT WITH COMPLEX UPR
AND SFC FEATURES AFFECTING AREA. SLOW MOVING UPR LOW NEAR NRN TEXAS
WILL BE PICKED UP BY DIVING NRN STREAM SHRT WV LATE TODAY AND
TONIGHT...WITH SRN STREAM SYSTEM BEING DAMPENED AS IT MERGES WITH
NRN STREAM OVER ERN U.S. LATE TUE. RESULTING SFC LOW TRACK W AND N
OF AREA AND UPR LVL DYNAMICS WILL PRODUCE MARGINAL SVR THREAT...LOW
CAPE BUT HIGH SHEAR...OVER ERN NC TUE AFTN AND EVENING. PER SPC DAY
2 OUTLOOK...MORE SIGNIFICANT THREAT WILL BE JUST S-SW OF AREA WITH
SLIGHTLY BETTER INSTABILITY. WILL CONTINUE MENTION IN HWO.
ADDITIONALLY...INCREASING WINDS MAY REACH ADVISORY CRITERIA ALONG
COASTAL SECTIONS...MAINLY OUTER BANKS...LATE TUE AFTN INTO EARLY
EVENING...AND WILL ADD MENTION OF THIS TO HWO AS WELL.
WITH SLIGHTLY BETTER MODEL AGREEMENT...RAISED POPS TO CATEGORICAL
LATE TUE AFTN AND ENDED POPS EARLIER INLAND TUE EVENING...WITH MINOR
ADJUSTMENTS TO TEMPS AND SKY COVER.
NO SIGNIFICANT CHANGES TO FCST FOR REST OF PERIOD. UPR FLOW WILL
BECOME MORE ZONAL...CUTTING OFF GULFMEX FEED...WITH MAINLY DRY NRN
STREAM SHRT WVS AFFECTING AREA THU AND AGAIN SAT. TEMPS WILL BE NEAR
SEASONAL WED-SUN.
&&
.AVIATION /19Z MONDAY THROUGH SATURDAY/...
SHORT TERM /THROUGH TUESDAY/...
AS OF 130 PM MON...HIGH PRESSURE WILL REMAIN IN CONTROL OF THE
SENSIBLE WEATHER THROUGH THIS EVENING...AHEAD OF AN APPROACHING
COMPLEX LOW PRESSURE SYSTEM THAT WILL IMPACT THE REGION LATE
TONIGHT THROUGH TUESDAY. NORTHERLY WINDS HAVE BECOME NORTHEASTERLY
THIS AFTERNOON GUSTING UPWARDS OF 20 KNOTS DUE IN PART TO
EXCELLENT MIXING AND STRONG CAA ACROSS THE REGION. VERY DRY ATMOS
IN PLACE SO DO NOT EXPECT STRATOCUMULUS DEVELOPMENT THIS
AFTERNOON. MID/HIGH CLOUDS DO NOT BEGIN IMPACTING WESTERN TAF
SITES/ISO/OAJ/PGV UNTIL NEAR SUNRISE TUES MORNING. WINDS WILL
CONTINUE VEERING OVERNIGHT...TO A MORE SOUTHEASTERLY RETURN FLOW
BY SUNRISE. OVERALL DRY ATMOS AND WINDS AROUND 4-6 KT OVERNIGHT
SHOULD INHIBIT ANY FOG FORMATION...THUS EXPECT VFR CONDITIONS
OVERNIGHT AS WELL.
PRECIP WILL BEGIN TO OVERSPREAD THE REGION FROM WEST TO EAST TUES.
A WARM FRONT WILL LIFT THROUGH THE REGION EARLY TUES
MORNING...SHELTERING IN DEWPOINTS IN THE UPPER 50S TO LOWER 60S.
WINDS WILL VEER FURTHER...EVENTUALLY BECOMING SOUTHWEST 15-20
KNOTS WITH SOME 25-30 KNOT GUSTS. LOW LEVEL JET OF 25-30 KNOTS
JUST OFF THE SURFACE TO 60-70 KNOTS AT 850MB WILL LEAD TO LOW
LEVEL WIND SHEAR CONCERNS. THE FRONT WILL EXIT OFF THE COAST LATE
TUES EVENING WITH CLEARING SKIES AND IMPROVING CONDITIONS FROM
WEST TO EAST. EXPECT MVFR IN LOWERED CEILINGS AND VISIBILITIES
FROM ABOUT 15Z TUES TO 06Z WED...WITH ISOLATED IFR/LIFR POSSIBLE
IN HEAVIER SHOWERS.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 315 AM MONDAY...SUB-VFR CONDITIONS ARE LIKELY TUESDAY INTO
TUESDAY EVENING IN WIDESPREAD SHOWERS/POSSIBLE STRONG THUNDERSTORMS
THAT ARE FORECAST TO OCCUR ALONG/AHEAD OF A STRONG COLD FRONT WHICH
WILL CROSS THE AREA TUESDAY NIGHT. PREVAILING VFR CONDITIONS ARE
THEN EXPECTED WEDNESDAY THROUGH FRIDAY AS A RELATIVELY DRY AIRMASS
EXTENDS OVER THE AREA.
&&
.MARINE...
SHORT TERM /THROUGH TONIGHT/...
AS OF 1010 AM MON...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
SMALL CRAFT CONDITIONS ACROSS THE COASTAL WATERS. NORTHWEST TO
NORTH-NORTHWEST WINDS 20-25 KNOTS WITH GUSTS NEAR 30 KNOTS HAVE
BEEN OBSERVED ACROSS THE NORTHERN COASTAL WATERS...WITH 20 KNOTS
GUSTING TO 25 KNOTS ELSEWHERE. SEAS HAVE BUILT TO 5 TO 7 FT OFF
DUCK BUT EXPECT SEAS 6-8 FT FARTHER OFFSHORE. GIVEN CURRENT
SCENARIO AND LATEST 12Z NAM/14Z RUC GUIDANCE...HAVE EXTENDED THE
SCAS FOR THE SOUTHERN COASTAL WATERS UNTIL NOON...THE PAMLICO AND
ALBEMARLE SOUNDS UNTIL 2PM...AND THE CENTRAL WATERS REMAIN THROUGH
LATE THIS EVENING.
HIGH PRESSURE WILL CONTINUE TO MIGRATE EAST ACROSS THE WATERS
TODAY. THE RIDGE WILL CREST ACROSS THE WATERS OVERNIGHT...ALLOWING
WINDS TO VEER FURTHER...BECOMING EAST LATE AND DIMINISHING 10-15
KNOTS...THEN SOUTHEAST BY SUNRISE TUES. SEAS WILL DIMINISH BELOW
SCA LEVELS LATER THIS EVENING AS WELL.
LONG TERM /TUESDAY THROUGH FRIDAY/...
AS OF 315 AM MONDAY...STRONG SCA TO MARGINAL GALE CONDITIONS ARE
LIKELY TUE AND TUE NIGHT AS DEVELOPING LOW PRES TRACKS W AND N OF
THE AREA...AND PUSHES A STRONG COLD FRONT THROUGH THE AREA FROM THE
WEST. MARINERS CAN EXPECT SOUTHERLY FLOW TO 30 KT OR HIGHER TUESDAY
SHIFTING TO WESTERLY THEN NORTHWESTERLY AT 30 KT OR HIGHER TUESDAY
NIGHT. IN THIS FLOW SEAS WILL LIKELY REACH OR EXCEED 10 FT FOR A
PERIOD TUESDAY INTO TUESDAY NIGHT. HIGHEST WINDS/SEAS ARE EXPECTED
OVER THE CENTRAL WATERS. WINDS WILL DIMINISH AND SEAS WILL SUBSIDE
LATE WEDNESDAY AS COLD ADVECTION WANES AND HIGH PRESSURE BUILDS OVER
THE WATERS. THE BROAD HIGH WILL CONTINUE OVER THE WATERS THURSDAY
THEN SHIFT OFFSHORE FRIDAY WITH WINDS 10-15 KT EXPECTED BOTH DAYS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 11 PM EST THIS EVENING FOR AMZ150-
152-154.
SMALL CRAFT ADVISORY UNTIL 2 PM EST THIS AFTERNOON FOR AMZ130-
135.
&&
$$
SYNOPSIS...DAG
NEAR TERM...DAG
SHORT TERM...JAC
LONG TERM...JBM
AVIATION...JBM/JME/DAG
MARINE...JBM/JME/DAG
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
249 PM CST MON DEC 26 2011
.SHORT TERM...TONIGHT THROUGH THURSDAY
249 PM CST MON DEC 26 2011
THE MAIN FOCUS IN THE SHORT TERM IS ON THE PRECIPITATION CHANCES
TONIGHT INTO TOMORROW...FOLLOWED BY ANOTHER SYSTEM WEDNESDAY NIGHT
INTO THURSDAY.
GUSTY SOUTHWEST WINDS DEVELOPED TODAY AHEAD OF A COLD FRONT THAT
CURRENTLY EXTENDS SOUTH OF A SURFACE LOW IN FAR SOUTHWEST ONTARIO
DOWN THROUGH EASTERN MINNESOTA AND WESTERN IOWA TOWARD OMAHA. WITH
INCREASING CLOUD COVER AND A WEAKENING PRESSURE GRADIENT...WILL BE
ALLOWING THE WIND ADVISORY TO EXPIRE AT 3PM THIS AFTERNOON.
FURTHER ALOFT...A CUT OFF LOW OVER THE SOUTHERN PLAINS WAS
STARTING TO GET A KICK EASTWARD FROM A NORTHERN STREAM TROUGH
PROPAGATING EAST THROUGH SOUTHERN CANADA. A FEW SHOWERS HAVE
KICKED UP DOWN SOUTH CLOSER TO THE CUT OFF LOW AND SOME OF THE HI-
RES MESO MODELS DO CONTINUE TO SHOW SOME RETURNS GOING INTO THE
EVENING AHEAD OF THE COLD FRONT...MAINLY IN NORTHEAST IOWA AND
SOUTHWEST WISCONSIN. 26.18Z RUC SOUNDINGS OUT OF DBQ/BLR/MSN SHOW
A QUICK MOISTENING UP OF THE LOW LEVELS THIS EVENING TOWARD 23-03Z
BEFORE THE FRONT COMES THROUGH. THESE THERMAL PROFILES SHOW A WARM
LAYER OF 4C AROUND 925MB AND SURFACE TEMPERATURES ABOVE
FREEZING...SO ANY PRECIPITATION THAT FALLS TONIGHT AHEAD OF THE
FRONT SHOULD STAY IN LIQUID FORM AND NOT REFREEZE.
AFTER THIS FIRST COLD FRONT COMES THROUGH...A SECONDARY COLD FRONT
WILL SWING AROUND ON THE BACK SIDE OF THE SURFACE LOW AND COME
THROUGH THE REGION LATE TONIGHT INTO TOMORROW MORNING. 26.12Z
NAM/GFS AND 26.18Z RUC SOUNDINGS SHOW STEEPENING LOW LEVEL LAPSE
RATES WITH AN INCREASE IN MOISTURE RIGHT AROUND THE INVERSION.
WITH TEMPERATURES IN 925-875MB DROPPING INTO THE -8 TO -10C
RANGE...IT SHOULD BE COLD ENOUGH FOR ICE TO FORM. THERE IS NOT
MUCH FORCING TO WORK WITH...BUT THE COMBINATION OF STEEP LAPSE
RATES...MOISTURE AND ICE AVAILABLE...SHOULD SEE SOME LIGHT SNOW OR
FLURRIES WITH A DUSTING OF SNOW ACCUMULATION NOT OUT OF THE
QUESTION IN SPOTS. THE 26.12Z GFS APPEARS TO BE AN OUTLIER AT
THIS POINT WITH SHOWING MUCH DEEPER MOISTURE ACROSS ALL OF THE
REGION AND TRIES TO PUT DOWN A MUCH LARGER AREA OF ACCUMULATING
LIGHT SNOW THROUGH TOMORROW MORNING. WITH THE LOW LEVEL MIXING AND
A TIGHT PRESSURE GRADIENT IN PLACE...IT WILL BE ANOTHER WINDY DAY
TOMORROW WITH WIND GUSTS UP TO 30KTS IN THE HIGHER TERRAIN.
A RIDGE OF HIGH PRESSURE WILL MOVE THROUGH TOMORROW NIGHT INTO
EARLY WEDNESDAY BEFORE ANOTHER QUICK MOVING MID LEVEL TROUGH
PROPAGATES EAST ACROSS SOUTHERN CANADA THROUGH THE MAINLY ZONAL
FLOW. THE BETTER FORCING GOES NORTH TOWARD LAKE SUPERIOR WITH THE
LOW ON WEDNESDAY BUT ANOTHER QUICK MOVING TROUGH WILL UNDERCUT THIS
LOW AND BRING SOME BETTER CHANCES FOR PRECIPITATION WEDNESDAY
NIGHT INTO THURSDAY. PRECIPITATION TYPE WILL BE AN ISSUE WITH THE
THERMAL PROFILE LIKELY WARMING ENOUGH FOR IT TO POSSIBLY CHANGE
OVER TO RAIN...ESPECIALLY ALONG AND SOUTH OF THE I-94 CORRIDOR.
.LONG TERM...THURSDAY NIGHT THROUGH MONDAY
249 PM CST MON DEC 26 2011
CONFIDENCE IN THE LONG TERM REMAINS LOW GIVEN THE FAST ZONAL FLOW
AND THE DIFFERENCES THAT HAVE BEEN SHOWING UP BETWEEN THE
GEM/GFS/ECMWF. RUN TO RUN CONSISTENCY IN THE MODELS HAS NOT BEEN
VERY GOOD IN THE EXTENDED...SO HAVE TRIED TO HIGHLIGHT THE BEST
CHANCES FOR ANY OVERLAP BETWEEN THESE MODELS...WHICH IS MAINLY
THURSDAY NIGHT INTO FRIDAY. AFTER THIS SERIES OF SHORTWAVE TROUGHS
COME THROUGH...IT LOOKS LIKE THERE WILL BE A PERIOD OF RIDGING
GOING INTO THE WEEKEND. AFTER THIS RIDGE SHIFTS EAST BY SATURDAY
NIGHT...THE FOCUS IS ON ANOTHER TROUGH AND HOW DEEP IT DIGS SOUTH.
THE 26.12Z GFS KEEPS MORE OF A ZONAL FLOW AND OPEN WAVE WHILE THE
26.12Z ECMWF AND GEM START CARVING OUT A MUCH MORE AMPLIFIED WAVE.
THE IMPACT PRECIPITATION WISE FOR OUR AREA IS NOT MUCH AS IT
APPEARS THAT THE FOCUS WOULD BE OFF TO THE EAST.
&&
.AVIATION...THIS AFTERNOON THRU TUESDAY
1135 AM CST MON DEC 26 2011
A TIGHT PRESSURE GRADIENT...AHEAD OF A COLD FRONT IN THE EASTERN
DAKOTAS AND A LOW NEAR LK WINNIPEG WILL SPREAD ACROSS THE AREA THIS
AFTERNOON. BRISK SOUTHWEST WINDS OF 15-30KT G35+KTS CAN BE EXPECTED
ESPECIALLY AT THE HIGHER TERRAIN SITES /KRST/KAUM/ETC./ THRU MUCH OF
THE AFTERNOON DURING PEAK HEATING/MIXING. GRADIENT WILL RELAX LATE
THIS AFTERNOON/EVENING WITH FRONTAL PASSAGE...WITH WINDS BECOMING
WEST DURING THE EVENING THEN NORTHWEST OVERNIGHT AND FOR TUE. CIGS/
VSBYS WILL REMAIN GOOD VFR THIS AFTERNOON/EVENING. SOME LOWER LEVEL
MOISTURE/CLOUDS/WEAK LIFT WILL SPREAD ACROSS THE TAF SITES BEHIND
THE FRONT FOR LATER TONIGHT/WED MORNING. MVFR CIGS EXPECTED WITH
THESE CLOUDS BEHIND THE FRONT LATE TONIGHT AND MUCH OF WED MORNING.
MAY BE ENOUGH LIFT FOR SCT FLURRIES AT/AROUND THE TAF SITES AND
INCLUDED A VCSH MENTION AT BOTH KRST/KLSE IN THE 08-18Z TIME-FRAME
AS THE 925-700MB TROUGH AXIS PASSES. GRADIENT TIGHTENS AGAIN TUE
MORNING AND FOR TUE AFTERNOON WITH BRISK NORTHWEST WINDS OF 15-25KT
G30KTS...AGAIN STRONGEST AT THE HIGHER ELEVATION SITES. MVFR CLOUDS/
CIGS TO BREAK UP/ADVECT OUT OF THE AREA WITH SUBSIDENCE LATE TUE
MORNING/AFTERNOON...WITH ANY WARMING/DEEPER MIXING TUE AFTERNOON
EXPECTED TO ADD TO THE GUSTINESS OF THE WINDS UNTIL THE GRADIENT
RELAXES LATE IN THE AFTERNOON/TUE EVENING.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
249 PM CST MON DEC 26 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION.....RRS
AREA FORECAST DISCUSSION
NWS MILWAUKEE/SULLIVAN WI
142 PM CST MON DEC 26 2011
.SHORT TERM...
TONIGHT AND TUESDAY - CONFIDENCE...MEDIUM
WATER VAPOR/RUC COMBO SHOWS SOUTHERN STREAM ENERGY CRUISING THROUGH
NRN TX WITH NORTHERN STREAM WAVE TRAVERSING EAST FROM ND INTO NRN
MN. SOME INCREASE IN MOISTURE NOTED OUT AHEAD OF SOUTHERN WAVE.
MID/HIGH CLOUDS RACING NORTHEAST FROM ERN IA AND CENTRL IL WILL
OVERSPREAD SRN WI THIS EVENING. LOW LEVELS WILL BE SLOW TO SATURATE
PER RUC AND NAM BUFKIT SOUNDINGS. IN FACT...THE LOW LEVELS REALLY DO
NOT MOISTEN UP UNTIL THE COLD AIR ADVECTION REGIME KICKS IN ON
TUESDAY. QPF TIED MORE TO RIGHT REAR QUADRANT AND THIS KEEPS PRECIP
JUST TO OUR SE. MODELS GENERATE LIGHT QPF TUESDAY IN COLD AIR
ADVECTION REGIME...WITH NORTHERN STREAM MID LEVEL TROUGH PASSAGE.
WILL GO WITH THE LOW POP/SHSN IDEA WITH MORE OF A FLURRY SCENARIO IN
THE AFTERNOON. OVERALL DEPTH OF MOISTURE LOOKS UNIMPRESSIVE. LOW
LEVELS A BIT MORE MOIST IN THE CAA REGIME. TEMPS WILL BE NOTICEABLY
COOLER WITH THE CLOUD COVER/GUSTY NW WINDS AND 925 TEMPS DROPPING TO
-6 TO -8C.
.TUESDAY NIGHT AND WEDNESDAY...FORECAST CONFIDENCE...MEDIUM.
AS THE STRONG SHORTWAVE MOVES OFF...A MORE WEST/NORTHWEST FAST FLOW
IS EXPECTED IN THE MID/UPPER LEVELS. ONE WEAK SHORTWAVE MOVES
ACROSS SOUTHERN WISCONSIN WEDNESDAY MORNING WHILE A SECOND
STRONGER SHORTWAVE APPROACHES LAKE SUPERIOR AREA LATE WEDNESDAY
AFTERNOON. THE PRECIPITATION FROM THIS SHORTWAVE IS EXPECTED TO
REMAIN TO THE NORTH.
A SURFACE HIGH WILL CROSS WISCONSIN TUESDAY NIGHT BEFORE WARM AIR
ADVECTION TAKES HOLD ON WEDNESDAY. LOW LEVELS ARE DRY WITH ONLY
MID LEVELS SATURATING ON WEDNESDAY WITH THE APPROACHING SHORTWAVE.
.WEDNESDAY NIGHT AND THURSDAY...FORECAST CONFIDENCE...MEDIUM.
THE SHORTWAVE MOVES ACROSS THE UPPER GREAT LAKES WEDNESDAY NIGHT
AS A BROAD ZONAL FLOW DEVELOPS IN THE MID/UPPER LEVELS AS A RATHER
WEAK SHORTWAVE MOVES TOWARDS NORTHERN MINNESOTA. ASSOCIATED WEAK
SURFACE LOW SHOULD REACH NORTHWEST MINNESOTA THURSDAY AFTERNOON
WITH SOUTH FLOW DEVELOPING ACROSS SOUTHERN WISCONSIN.
.LONG TERM...
.FRIDAY THROUGH SUNDAY...FORECAST CONFIDENCE MEDIUM.
THE MILD WEATHER PATTERN CONTINUES AS THE MODELS CONTINUE THE
PARADE OF WEAK SHORTWAVES IN THE FAST ZONAL FLOW. ONE SHORTWAVE
MOVES ACROSS FRIDAY. 12Z GFS TAKES A FAST SHORTWAVE JUST NORTH OF
LAKE SUPERIOR WHILE THE 00Z ECMWF BEGINS TO DIG A MAJOR TROUGH
OVER THE PLAINS. FOR NOW WILL LEAN MORE TOWARD THE GFS.
A WEAK TROUGH OF LOW PRESSURE MOVES ACROSS WISCONSIN FRIDAY WHILE
WITH A WEAK RIDGE ON THE 12Z GFS. MOTH MODELS DEVELOP A TROUGH
OVER THE WESTERN GREAT LAKES SUNDAY...BUT GFS IS FARTHER NORTH
WITH THE 00Z ECMWF EXTENDING THE TROUGH INTO SOUTHEAST MISSOURI
AND STRENGTHENS IT. NOT READY TO BUY IN TO THIS SCENARIO AND WILL
TREND TOWARD THE 12Z GFS. NEW 12Z ECMWF HAS NOW TRENDED TOWARD
THE 12Z GFS.
.MONDAY...FORECAST CONFIDENCE MEDIUM.
AS THE UPPER TROUGH DEEPENS ON THE 00Z ECMWF IT TAKES A STRONG
SURFACE LOW NORTH INTO LOWER MICHIGAN. MEANWHILE THE GFS QUICKLY PUSHES
A SURFACE LOW OFF THE SOUTHEAST CANADIAN COAST WITH HIGH PRESSURE
BUILDING OVER THE UPPER MIDWEST.
THE GFS IS MORE CONSISTENT WITH THE 06Z DGEX AND WILL TREND MORE
TOWARD THESE MODELS. NEW 12Z ECMWF HAS NOW TRENDED MORE TOWARD
THE 12Z GFS BUT THE 12Z ECMWF STILLS DIGS THE MID/UPPER TROUGH
MORE ACROSS THE EASTERN GREAT LAKES. PREFER THE LOWER APMPLITUDE
12Z GFS/06Z DGEX.
&&
.AVIATION/00Z TAFS/...
MID DECK INCREASES THIS EVENING AS SOUTHWEST
FLOW BRINGS MOISTURE UP AND OUT AHEAD OF SOUTHERN STREAM UPPER LOW.
LOWER LEVELS NOT PROGGD TO SATURATE UNTIL COLD AIR ADVECTION REGIME
KICKS IN ON TUESDAY. WILL GO WITH MVFR CEILINGS. SPOTTY LIGHT PRECIP
IS POSSIBLE THOUGH NOT EXPECTING ANYTHING MAJOR WITH COLUMN MOISTURE
LOOKING MEAGHER.
&&
.MARINE...
STRONG SOUTHWEST GRADIENT BETWEEN LOW CROSSING SOUTHERN CANADA
AND HIGH IN EASTERN US. WINDS HAVE RAMPED UP AND GUSTING TO SCA
CRITERIA.
WINDS MAY DROP BRIEFLY BELOW ADVISORY CRITERIA LATE TONIGHT AND
EARLY TUESDAY BEFORE STRONG PRESSURE RISES AND COLD ADVECTION BEHIND
COLD FRONT KICK IN AND KEEP THINGS BRISK INTO TUESDAY EVENING.
SMALL CRAFT ADVISORY RUNS FROM TODAY THROUGH EARLY WEDNESDAY FOR
SIMPLICITY.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 9 AM CST WEDNESDAY FOR LMZ643>646.
&&
$$
TONIGHT/TUESDAY AND AVIATION/MARINE...COLLAR
TUESDAY NIGHT THROUGH MONDAY...HENTZ