Forecast Discussions mentioning any of
"HRRR" "RR" "RUC13" "RUC" received at GSD on 12/25/11
AREA FORECAST DISCUSSION
NWS DENVER CO
837 PM MST SAT DEC 24 2011
.UPDATE...WILL BE UPDATING THE FORECAST FOR LESS WIND ALONG THE
FOOTHILLS THIS EVENING. SURFACE PRESSURE GRADIENTS ACROSS THE
STATE ARE WEAK...AND WINDS ALOFT ARE LIGHT AND OUT OF THE NORTH.
ALSO DECREASED THE CLOUD COVER SINCE THE CIRRUS SHIELD THAT WAS
OVER WYOMING EARLIER IN THE AFTERNOON HAS EVAPORATED UNDER THE
SUBSIDENCE OF THE UPPER RIDGE OVER THE REGION.
&&
.AVIATION...NO CHANGES NECESSARY FOR THE AVIATION FORECASTS.
&&
.PREV DISCUSSION... /ISSUED 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.
&&
$$
SHORT TERM...DANKERS
LONG TERM....ENTREKIN
AVIATION...RPK
AREA FORECAST DISCUSSION
NWS ALBANY NY
926 PM EST SAT DEC 24 2011
.SYNOPSIS...
HIGH PRESSURE 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. WEAK HIGH PRESSURE WILL
CONTROL OUR WEATHER MONDAY AND MONDAY NIGHT. ANOTHER AREA OF LOW
PRESSURE WILL TRACK NORTHEAST INTO OUR REGION TUESDAY AND TUESDAY
NIGHT WITH A CHANCE FOR SOME HEAVIER PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 930 PM EST...MAINLY CLEAR SKIES/LIGHT WINDS
CONTINUE...ALLOWING TEMPS TO DIP INTO THE TEENS IN MOST VALLEY
REGIONS...WITH ZERO TO 10 ABOVE ACROSS THE SOUTHERN
ADIRONDACKS...AND HIGHER ELEVATIONS ACROSS WESTERN NEW ENGLAND.
CLOUDS CONTINUE TO APPROACH FROM THE SOUTHWEST...ALTHOUGH HAVE
SHOWN SOME SIGNS OF DISSIPATING. HOWEVER...AS A BIT OF ATLANTIC
MOISTURE BECOMES ENTRAINED INTO THE LOW LEVEL WARM ADVECTION
PROCESS...WE THINK CLOUDS SHOULD SOLIDIFY ONCE AGAIN AFTER
MIDNIGHT TO OUR SOUTHWEST...AND THEN MOVE ACROSS AT LEAST THE NW
HALF OF THE REGION TOWARD AND AROUND DAYBREAK. SOME FLURRIES ARE
ALSO POSSIBLE...AS SOME OF THIS MOISTURE IS SQUEEZED OUT BY UPPER
LEVEL DYNAMICS WITH APPROACH/PASSAGE OF MID LEVEL SHORTWAVE.
SO...HAVE KEPT MUCH OF FORECAST ENTACT...WITH MINS EXPECTED TO
OCCUR AROUND MIDNIGHT...THEN STEADY OR RISING TEMPS TOWARD
DAYBREAK ONCE CLOUDS DEVELOP/INCREASE.
PREVIOUS DISCUSSIONS FOLLOW...
AS OF 645 PM EST...CLEAR SKIES AND LIGHT WINDS HAVE ALLOWED TEMPS
TO DROP RAPIDLY...ALREADY INTO THE TEENS ACROSS THE LAKE
GEORGE/SARATOGA REGION AND SOUTHERN VT...WITH SINGLE DIGITS ACROSS
THE WESTERN ADIRONDACKS. WE EXPECT TEMPS TO CONTINUE FALLING
THROUGH MIDNIGHT...AND HAVE LOWERED MINS A BIT BY ABOUT 2-4
DEGREES TO ACCOMMODATE CURRENT TRENDS.
THE MINS SHOULD OCCUR AROUND MIDNIGHT. THEN...CLOUDS SHOULD
INCREASE/DEVELOP FROM THE SW AS WARM ADVECTION INCREASES. LATEST
HRRR AND RUC13 DEPICT DEVELOPING CLOUD LAYER AROUND 5000 FT AGL
DEVELOPING AFTER MIDNIGHT ACROSS EXTREME WESTERN AREAS...THEN
EXPANDING NE TO ENCOMPASS MUCH OF THE REGION BY DAYBREAK. IN
FACT...THE COMBINATION OF THESE LOWER CLOUDS...AND SOME MID LEVEL
CLOUDS WITH PASSING SHORTWAVE MAY LEAD TO SOME SPOTTY LIGHT SNOW
OR FLURRIES TOWARD DAYBREAK ACROSS THE MOHAWK VALLEY/WESTERN
ADIRONDACKS/LAKE GEORGE SARATOGA REGION BY DAYBREAK. BASED ON THIS
THINKING...HAVE INCREASED CLOUD COVERAGE ACROSS N/W AREAS WELL
AFTER MIDNIGHT...AND HAVE ALSO INCLUDED MENTION OF FLURRIES. TEMPS
SHOULD ALSO RISE AFTER MIDNIGHT GIVEN THE PROSPECTS FOR INCREASING
CLOUDS...AS WELL AS SOME DEVELOPING WIND.
PREVIOUS DISCUSSION FOLLOWS...
LOW LEVEL RIDGING WILL BUILD EAST THIS EVENING...WHICH WILL CAUSE
THE CURRENT LIGHT WINDS TO BECOME LIGHT SOUTH LATE TONIGHT. BEFORE
THE WEAK WARM ADVECTION BEGINS...TEMPERATURES SHOULD BE ABLE TO
DROP QUICKLY THIS EVENING. LOWS SHOULD BE IN THE TEENS...SINGLE
NUMBERS IN THE SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA REGION
AND SOUTHERN GREEN MOUNTAINS. SOME CLOUDS AHEAD OF THE NEXT SYSTEM
COULD SPREAD INTO THE REGION BY SUNRISE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
UPPER IMPULSE IN THE WESTERN GREAT LAKES WILL TRACK THROUGH THE
REGION LATER TOMORROW AND THROUGH TOMORROW NIGHT. INCREASING WARM
ADVECTION AND SOUTHERLY WINDS WILL HELP TEMPERATURES REACH INTO
THE MID 30S TO LOWER 40S...WITH THICKENING CLOUD COVER. BY
CHRISTMAS EVENING...SCATTERED SHOWERS AND SNOW SHOWERS WILL SPREAD
ACROSS MOST AREAS.
THE BEST CHANCES FOR SNOW SHOWERS SHOULD BE IN NORTHERN AREAS
CHRISTMAS NIGHT WHERE SNOW SHOWERS WILL BE LIKELY...BUT SCATTERED
SNOW SHOWERS WILL OCCUR OVER MOST AREAS THROUGH THE NIGHT...WITH
SOME DUSTINGS POSSIBLE. AN INCH OR TWO IS POSSIBLE IN THE WESTERN
MOHAWK VALLEY AND SOUTHERN ADIRONDACKS. LOWS CHRISTMAS NIGHT
SHOULD BE IN THE 20S TO AROUND 30...WITH SOME POSSIBLE CLEARING
IN WESTERN AREAS TOWARD MORNING.
A BRIEF SHOT OF COLD AIR SHOULD SPREAD ACROSS THE REGION
MONDAY...BUT THE QUICK ADVANCE OF A SYSTEM OUT OF THE SOUTHERN
PLAINS AND NORTHERN GULF COAST WILL PREVENT TOO MUCH COOLING. IN
FACT THERE ARE SOME INDICATIONS THAT SOME WEAK WARM ADVECTION
COULD BEGIN BY THE END OF THE DAY. HIGHS MONDAY IN THE 30S TO
LOWER 40S...AROUND 30 SOUTHERN ADIRONDACKS.
SOUTHERN STREAM SYSTEM APPROACHES MONDAY NIGHT WITH INCREASING
SOUTHERLY BOUNDARY LAYER WINDS...AND SOME INCREASING HIGH CLOUDS.
LOWS MONDAY NIGHT IN THE UPPER TEENS TO MID 20S.
INCREASING SOUTHERLY BOUNDARY LAYER WINDS WILL INCREASE WARM
ADVECTION SO BOUNDARY LAYER TEMPERATURES SHOULD WARM ENOUGH SO
THAT WITH ENOUGH MIXING THROUGH THE DAY...HIGH TEMPERATURES SHOULD
REACH THE LOWER 40S IN MANY AREAS...BUT UPPER 30S TO AROUND 40 IN
HIGHER ELEVATIONS WEST AND NORTH OF THE CAPITAL DISTRICT. RAIN
SHOULD SPREAD NORTHEAST THROUGH THE REGION THROUGH THE DAY...WITH
A MIX IN HIGHER ELEVATIONS WEST AND NORTH OF THE CAPITAL DISTRICT
TURNING TO RAIN. STILL SOME SPREAD IN GUIDANCE WITH REGARD TO THE
DETAILS IN STORM TRACK AND STRENGTH OF WARM ADVECTION...WHICH
MEANS SLIGHT SHIFTS IN THE STORM TRACK AND BOUNDARY LAYER THERMAL
GRADIENT WOULD RESULT IN A SHIFT IN WHERE POTENTIAL MIXED
PRECIPITATION COULD OCCUR. FOR NOW...ANY TRENDS WOULD INDICATE
POTENTIALLY WARMER AND RAINER CONDITIONS FURTHER NORTH AND
WEST...BUT THIS TIME OF YEAR...KEEPING ALL OPTIONS OPEN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE 12 UTC ECMWF/GFS/GGEM HAVE ALL COME TOGETHER ON A SURFACE
CYCLONE TRACKING UP THE EASTERN SEABOARD FOR TUESDAY NIGHT INTO
WEDNESDAY MORNING...AS BOTH APPROACHING NORTHERN AND SOUTHERN
STREAMS PHASE TOGETHER. THERE IS STILL SOME UNCERTAINTY REGARDING
THE STRENGTH AND TRACK OF THIS SYSTEM. THE 12 UTC ECMWF SHOWS A
RAPIDLY DEEPENING STORM...WITH A TRACK OVER EASTERN PARTS OF THE
CWA. MEANWHILE...THE GFS AND GGEM ARE WEAKER...WITH A TRACK FURTHER
TO THE EAST. EVEN WITH THE MORE OFFSHORE SCENARIOS...THERE IS LITTLE
COLD AIR IN PLACE ACROSS THE REGION AT THE SURFACE WITH TEMPS ON
TUESDAY EVENING STILL WELL ABOVE FREEZING IN MANY AREAS. THE
GFS/GGEM SHOW 850 HPA TEMPS THAT ARE JUST SLIGHTLY BELOW
FREEZING...AND IF THE ECMWF SCENARIO OCCURS...MUCH WARMER AIR ALOFT
WILL GET PULLED INTO AT LEAST CENTRAL AND EASTERN AREAS WITH A SURGE
OF 850 HPA TEMPS WELL ABOVE ZERO. THE 12 UTC GEFS IS SHOWING VERY
STRONG V WIND ANOMALIES /2 TO 3 STD ABOVE NORMAL/ AT 850 HPA JUST
SOUTH OF THE AREA...WHICH WOULD SUGGEST STRONG SOUTHERLY FLOW
APPROACHING OUR REGION.
FOR NOW...WILL PLAY THE FORECAST AS MAINLY RAIN OR RAIN/SNOW MIX FOR
VALLEYS...WITH MAINLY SNOW FOR THE HIGHEST TERRAIN AND AREAS FAR TO
THE NORTH AND WEST. THERE MAY BRIEFLY BE PERIODS OF PL/FZRA
POSSIBLE AS WELL...BUT THIS FAR OUT...WILL NOT TRY TO PIN DOWN
TIMING/EXACT PTYPE UNTIL GUIDANCE BECOMES A LITTLE MORE CLEAR. WITH
THE UPPER PATTERN STILL NOT MUCH DIFFERENT THAT RECENT WEEKS...AND
COLD AIR CONTINUING TO BE LACKING ACROSS THE REGION...THERE IS
LITTLE REASON TO SUSPECT THAT THIS STORM WILL BE ANY DIFFERENT THAN
THE PAST SEVERAL...WHICH HAS SHOWN THAT VALLEY AREAS WILL STRUGGLE
TO SEE RAIN CHANGE OVER TO SNOW AND LEAD TO SIGNIFICANT
ACCUMULATIONS. STILL...WILL CONTINUE TO CLOSELY MONITOR
DETERMINISTIC/ENSEMBLE MODEL GUIDANCE OVER THE NEXT FEW DAYS AND
MAKE ANY ADJUSTMENTS AS NECESSARY.
IN THE WAKE OF THE STORM...COLDER AIR WILL FILTER INTO THE REGION
FOR WEDNESDAY NIGHT WITH 850 HPA TEMPS DROPPING TO -10 TO -15
DEGREES C. THIS WILL LEAD TO TEENS FOR MOST AREAS...WITH SINGLE
DIGITS IN THE HIGHER TERRAIN FOR MIN TEMPS. WHILE THIS STILL SEEM
PRETTY COLD...ITS ACTUALLY NOT FAR OFF WHAT IS CONSIDERED AVERAGE OR
NORMAL FOR THIS TIME OF YEAR.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR THURSDAY INTO THURSDAY
NIGHT WITH DRY WEATHER AND SEASONABLE TEMPS. VALLEY AREAS WILL SEE
MAX TEMPS IN THE LOWER TO MIDDLE 30S...AND MINS THURSDAY NIGHT WILL
BE A LITTLE WARMER THAN WED NIGHT...WITH MAINLY TEENS AND 20S.
ALTHOUGH THE MODELS DISAGREE ON THE DETAILS FOR WHAT OCCURS IN THE
LATE WEEK PERIOD...BOTH THE 12 UTC GFS/ECMWF SHOW A NORTHERN STREAM
TROUGH SWINGING ACROSS THE AREA SOMETIME DURING THE FRIDAY INTO
FRIDAY NIGHT PERIOD. WILL ALLOW FOR LOW CHC/SLIGHT CHC POPS ACROSS
THE AREA...WITH P-TYPE RAIN AND/OR SNOW GENERALLY ELEVATION OR
DIURNALLY DEPENDENT. MAX TEMPS WILL BE A LITTLE ABOVE SEASONAL
AVERAGES FOR FRIDAY INTO SATURDAY WITH MID 30S TO LOWER 40S FOR
VALLEY AREAS...AND MIN TEMPS GENERALLY IN THE 20S.
&&
.AVIATION /02Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST 06Z/SUN. THEN...THERE
IS A SLIGHT CHC FOR MVFR CIGS AT KGFL...WITH MAINLY VFR LEVEL
CLOUDS ELSEWHERE AFTER MIDNIGHT THROUGH EARLY SUNDAY MORNING AS A
WEAK WARM FRONT APPROACHES FROM THE SOUTHWEST. SOME FLURRIES COULD
OCCUR DURING THIS TIME AS WELL AT KGFL...WHILE REMAINING MAINLY
N/W OF KALB.
FOR SUNDAY...OTHER THAN ANY BRIEF PERIODS OF MVFR CIGS AT
KGFL...EXPECT VFR CONDITIONS...DESPITE CIGS OF 6000-12000 FT AGL.
CIGS WILL TREND LOWER FROM NW TO SE TOWARD AND AFTER SUNSET...BUT
SHOULD REMAIN VFR.
ANY SNOW SHOWERS PRECEDING APPROACHING COLD FRONT SHOULD HOLD OFF
UNTIL AROUND OR JUST AFTER 00Z/MON.
LIGHT/VARIABLE WINDS THIS EVENING WILL TREND INTO THE SE TO S
BEFORE DAYBREAK...AT 5-10 KT. ON SUNDAY...SOUTH WINDS WILL
INCREASE TO 8-14 KT...WITH SOME GUSTS OF 20-25 KT POSSIBLE AT KALB
DUE TO FUNNELING EFFECTS WITHIN THE HUDSON RIVER VALLEY.
OUTLOOK...
SUN NT...VFR/MVFR...SCT -SHSN.
MON...VFR. NO SIG WX.
TUE-WED...VFR/MVFR...RAIN AND/OR SNOW POSSIBLE.
THU...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.
AN AREA OF LOW PRESSURE IS EXPECTED TO BRING MODERATE RAINFALL
AMOUNTS ACROSS THE REGION TUESDAY INTO WEDNESDAY...WITH POSSIBLE
MIXED PRECIPITATION IN HIGHER ELEVATIONS.
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...KL/NAS
SHORT TERM...NAS
LONG TERM...FRUGIS
AVIATION...KL/JPV
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS ALBANY NY
650 PM EST SAT DEC 24 2011
.SYNOPSIS...
HIGH PRESSURE 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. WEAK HIGH PRESSURE WILL
CONTROL OUR WEATHER MONDAY AND MONDAY NIGHT. ANOTHER AREA OF LOW
PRESSURE WILL TRACK NORTHEAST INTO OUR REGION TUESDAY AND TUESDAY
NIGHT WITH A CHANCE FOR SOME HEAVIER PRECIPITATION.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
AS OF 645 PM EST...CLEAR SKIES AND LIGHT WINDS HAVE ALLOWED TEMPS
TO DROP RAPIDLY...ALREADY INTO THE TEENS ACROSS THE LAKE
GEORGE/SARATOGA REGION AND SOUTHERN VT...WITH SINGLE DIGITS ACROSS
THE WESTERN ADIRONDACKS. WE EXPECT TEMPS TO CONTINUE FALLING
THROUGH MIDNIGHT...AND HAVE LOWERED MINS A BIT BY ABOUT 2-4
DEGREES TO ACCOMMODATE CURRENT TRENDS.
THE MINS SHOULD OCCUR AROUND MIDNIGHT. THEN...CLOUDS SHOULD
INCREASE/DEVELOP FROM THE SW AS WARM ADVECTION INCREASES. LATEST
HRRR AND RUC13 DEPICT DEVELOPING CLOUD LAYER AROUND 5000 FT AGL
DEVELOPING AFTER MIDNIGHT ACROSS EXTREME WESTERN AREAS...THEN
EXPANDING NE TO ENCOMPASS MUCH OF THE REGION BY DAYBREAK. IN
FACT...THE COMBINATION OF THESE LOWER CLOUDS...AND SOME MID LEVEL
CLOUDS WITH PASSING SHORTWAVE MAY LEAD TO SOME SPOTTY LIGHT SNOW
OR FLURRIES TOWARD DAYBREAK ACROSS THE MOHAWK VALLEY/WESTERN
ADIRONDACKS/LAKE GEORGE SARATOGA REGION BY DAYBREAK. BASED ON THIS
THINKING...HAVE INCREASED CLOUD COVERAGE ACROSS N/W AREAS WELL
AFTER MIDNIGHT...AND HAVE ALSO INCLUDED MENTION OF FLURRIES. TEMPS
SHOULD ALSO RISE AFTER MIDNIGHT GIVEN THE PROSPECTS FOR INCREASING
CLOUDS...AS WELL AS SOME DEVELOPING WIND.
PREVIOUS DISCUSSION FOLLOWS...
LOW LEVEL RIDGING WILL BUILD EAST THIS EVENING...WHICH WILL CAUSE
THE CURRENT LIGHT WINDS TO BECOME LIGHT SOUTH LATE TONIGHT. BEFORE
THE WEAK WARM ADVECTION BEGINS...TEMPERATURES SHOULD BE ABLE TO
DROP QUICKLY THIS EVENING. LOWS SHOULD BE IN THE TEENS...SINGLE
NUMBERS IN THE SOUTHERN ADIRONDACKS...LAKE GEORGE SARATOGA REGION
AND SOUTHERN GREEN MOUNTAINS. SOME CLOUDS AHEAD OF THE NEXT SYSTEM
COULD SPREAD INTO THE REGION BY SUNRISE.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH TUESDAY/...
UPPER IMPULSE IN THE WESTERN GREAT LAKES WILL TRACK THROUGH THE
REGION LATER TOMORROW AND THROUGH TOMORROW NIGHT. INCREASING WARM
ADVECTION AND SOUTHERLY WINDS WILL HELP TEMPERATURES REACH INTO
THE MID 30S TO LOWER 40S...WITH THICKENING CLOUD COVER. BY
CHRISTMAS EVENING...SCATTERED SHOWERS AND SNOW SHOWERS WILL SPREAD
ACROSS MOST AREAS.
THE BEST CHANCES FOR SNOW SHOWERS SHOULD BE IN NORTHERN AREAS
CHRISTMAS NIGHT WHERE SNOW SHOWERS WILL BE LIKELY...BUT SCATTERED
SNOW SHOWERS WILL OCCUR OVER MOST AREAS THROUGH THE NIGHT...WITH
SOME DUSTINGS POSSIBLE. AN INCH OR TWO IS POSSIBLE IN THE WESTERN
MOHAWK VALLEY AND SOUTHERN ADIRONDACKS. LOWS CHRISTMAS NIGHT
SHOULD BE IN THE 20S TO AROUND 30...WITH SOME POSSIBLE CLEARING
IN WESTERN AREAS TOWARD MORNING.
A BRIEF SHOT OF COLD AIR SHOULD SPREAD ACROSS THE REGION
MONDAY...BUT THE QUICK ADVANCE OF A SYSTEM OUT OF THE SOUTHERN
PLAINS AND NORTHERN GULF COAST WILL PREVENT TOO MUCH COOLING. IN
FACT THERE ARE SOME INDICATIONS THAT SOME WEAK WARM ADVECTION
COULD BEGIN BY THE END OF THE DAY. HIGHS MONDAY IN THE 30S TO
LOWER 40S...AROUND 30 SOUTHERN ADIRONDACKS.
SOUTHERN STREAM SYSTEM APPROACHES MONDAY NIGHT WITH INCREASING
SOUTHERLY BOUNDARY LAYER WINDS...AND SOME INCREASING HIGH CLOUDS.
LOWS MONDAY NIGHT IN THE UPPER TEENS TO MID 20S.
INCREASING SOUTHERLY BOUNDARY LAYER WINDS WILL INCREASE WARM
ADVECTION SO BOUNDARY LAYER TEMPERATURES SHOULD WARM ENOUGH SO
THAT WITH ENOUGH MIXING THROUGH THE DAY...HIGH TEMPERATURES SHOULD
REACH THE LOWER 40S IN MANY AREAS...BUT UPPER 30S TO AROUND 40 IN
HIGHER ELEVATIONS WEST AND NORTH OF THE CAPITAL DISTRICT. RAIN
SHOULD SPREAD NORTHEAST THROUGH THE REGION THROUGH THE DAY...WITH
A MIX IN HIGHER ELEVATIONS WEST AND NORTH OF THE CAPITAL DISTRICT
TURNING TO RAIN. STILL SOME SPREAD IN GUIDANCE WITH REGARD TO THE
DETAILS IN STORM TRACK AND STRENGTH OF WARM ADVECTION...WHICH
MEANS SLIGHT SHIFTS IN THE STORM TRACK AND BOUNDARY LAYER THERMAL
GRADIENT WOULD RESULT IN A SHIFT IN WHERE POTENTIAL MIXED
PRECIPITATION COULD OCCUR. FOR NOW...ANY TRENDS WOULD INDICATE
POTENTIALLY WARMER AND RAINER CONDITIONS FURTHER NORTH AND
WEST...BUT THIS TIME OF YEAR...KEEPING ALL OPTIONS OPEN.
&&
.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE 12 UTC ECMWF/GFS/GGEM HAVE ALL COME TOGETHER ON A SURFACE
CYCLONE TRACKING UP THE EASTERN SEABOARD FOR TUESDAY NIGHT INTO
WEDNESDAY MORNING...AS BOTH APPROACHING NORTHERN AND SOUTHERN
STREAMS PHASE TOGETHER. THERE IS STILL SOME UNCERTAINTY REGARDING
THE STRENGTH AND TRACK OF THIS SYSTEM. THE 12 UTC ECMWF SHOWS A
RAPIDLY DEEPENING STORM...WITH A TRACK OVER EASTERN PARTS OF THE
CWA. MEANWHILE...THE GFS AND GGEM ARE WEAKER...WITH A TRACK FURTHER
TO THE EAST. EVEN WITH THE MORE OFFSHORE SCENARIOS...THERE IS LITTLE
COLD AIR IN PLACE ACROSS THE REGION AT THE SURFACE WITH TEMPS ON
TUESDAY EVENING STILL WELL ABOVE FREEZING IN MANY AREAS. THE
GFS/GGEM SHOW 850 HPA TEMPS THAT ARE JUST SLIGHTLY BELOW
FREEZING...AND IF THE ECMWF SCENARIO OCCURS...MUCH WARMER AIR ALOFT
WILL GET PULLED INTO AT LEAST CENTRAL AND EASTERN AREAS WITH A SURGE
OF 850 HPA TEMPS WELL ABOVE ZERO. THE 12 UTC GEFS IS SHOWING VERY
STRONG V WIND ANOMALIES /2 TO 3 STD ABOVE NORMAL/ AT 850 HPA JUST
SOUTH OF THE AREA...WHICH WOULD SUGGEST STRONG SOUTHERLY FLOW
APPROACHING OUR REGION.
FOR NOW...WILL PLAY THE FORECAST AS MAINLY RAIN OR RAIN/SNOW MIX FOR
VALLEYS...WITH MAINLY SNOW FOR THE HIGHEST TERRAIN AND AREAS FAR TO
THE NORTH AND WEST. THERE MAY BRIEFLY BE PERIODS OF PL/FZRA
POSSIBLE AS WELL...BUT THIS FAR OUT...WILL NOT TRY TO PIN DOWN
TIMING/EXACT PTYPE UNTIL GUIDANCE BECOMES A LITTLE MORE CLEAR. WITH
THE UPPER PATTERN STILL NOT MUCH DIFFERENT THAT RECENT WEEKS...AND
COLD AIR CONTINUING TO BE LACKING ACROSS THE REGION...THERE IS
LITTLE REASON TO SUSPECT THAT THIS STORM WILL BE ANY DIFFERENT THAN
THE PAST SEVERAL...WHICH HAS SHOWN THAT VALLEY AREAS WILL STRUGGLE
TO SEE RAIN CHANGE OVER TO SNOW AND LEAD TO SIGNIFICANT
ACCUMULATIONS. STILL...WILL CONTINUE TO CLOSELY MONITOR
DETERMINISTIC/ENSEMBLE MODEL GUIDANCE OVER THE NEXT FEW DAYS AND
MAKE ANY ADJUSTMENTS AS NECESSARY.
IN THE WAKE OF THE STORM...COLDER AIR WILL FILTER INTO THE REGION
FOR WEDNESDAY NIGHT WITH 850 HPA TEMPS DROPPING TO -10 TO -15
DEGREES C. THIS WILL LEAD TO TEENS FOR MOST AREAS...WITH SINGLE
DIGITS IN THE HIGHER TERRAIN FOR MIN TEMPS. WHILE THIS STILL SEEM
PRETTY COLD...ITS ACTUALLY NOT FAR OFF WHAT IS CONSIDERED AVERAGE OR
NORMAL FOR THIS TIME OF YEAR.
HIGH PRESSURE WILL MOVE ACROSS THE REGION FOR THURSDAY INTO THURSDAY
NIGHT WITH DRY WEATHER AND SEASONABLE TEMPS. VALLEY AREAS WILL SEE
MAX TEMPS IN THE LOWER TO MIDDLE 30S...AND MINS THURSDAY NIGHT WILL
BE A LITTLE WARMER THAN WED NIGHT...WITH MAINLY TEENS AND 20S.
ALTHOUGH THE MODELS DISAGREE ON THE DETAILS FOR WHAT OCCURS IN THE
LATE WEEK PERIOD...BOTH THE 12 UTC GFS/ECMWF SHOW A NORTHERN STREAM
TROUGH SWINGING ACROSS THE AREA SOMETIME DURING THE FRIDAY INTO
FRIDAY NIGHT PERIOD. WILL ALLOW FOR LOW CHC/SLIGHT CHC POPS ACROSS
THE AREA...WITH P-TYPE RAIN AND/OR SNOW GENERALLY ELEVATION OR
DIURNALLY DEPENDENT. MAX TEMPS WILL BE A LITTLE ABOVE SEASONAL
AVERAGES FOR FRIDAY INTO SATURDAY WITH MID 30S TO LOWER 40S FOR
VALLEY AREAS...AND MIN TEMPS GENERALLY IN THE 20S.
&&
.AVIATION /00Z SUNDAY THROUGH THURSDAY/...
VFR CONDITIONS ARE EXPECTED THROUGH AT LEAST 06Z/SUN. THEN...THERE
IS A SLIGHT CHC FOR MVFR CIGS AT KGFL...WITH MAINLY VFR LEVEL
CLOUDS ELSEWHERE AFTER MIDNIGHT THROUGH EARLY SUNDAY MORNING AS A
WEAK WARM FRONT APPROACHES FROM THE SOUTHWEST. SOME FLURRIES COULD
OCCUR DURING THIS TIME AS WELL AT KGFL...WHILE REMAINING MAINLY
N/W OF KALB.
FOR SUNDAY...OTHER THAN ANY BRIEF PERIODS OF MVFR CIGS AT
KGFL...EXPECT VFR CONDITIONS...DESPITE CIGS OF 6000-12000 FT AGL.
CIGS WILL TREND LOWER FROM NW TO SE TOWARD AND AFTER SUNSET...BUT
SHOULD REMAIN VFR.
ANY SNOW SHOWERS PRECEDING APPROACHING COLD FRONT SHOULD HOLD OFF
UNTIL AROUND OR JUST AFTER 00Z/MON.
LIGHT/VARIABLE WINDS THIS EVENING WILL TREND INTO THE SE TO S
BEFORE DAYBREAK...AT 5-10 KT. ON SUNDAY...SOUTH WINDS WILL
INCREASE TO 8-14 KT...WITH SOME GUSTS OF 20-25 KT POSSIBLE AT KALB
DUE TO FUNNELING EFFECTS WITHIN THE HUDSON RIVER VALLEY.
OUTLOOK...
SUN NT...VFR/MVFR...SCT -SHSN.
MON...VFR. NO SIG WX.
TUE-WED...VFR/MVFR...RAIN AND/OR SNOW POSSIBLE.
THU...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.
AN AREA OF LOW PRESSURE IS EXPECTED TO BRING MODERATE RAINFALL
AMOUNTS ACROSS THE REGION TUESDAY INTO WEDNESDAY...WITH POSSIBLE
MIXED PRECIPITATION IN HIGHER ELEVATIONS.
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...KL/NAS
SHORT TERM...NAS
LONG TERM...FRUGIS
AVIATION...KL/JPV
HYDROLOGY...NAS
AREA FORECAST DISCUSSION
NWS LINCOLN IL
1131 PM CST THU DEC 22 2011
.DISCUSSION...
ISSUED 900 PM CST THU DEC 22 2011
BAND OF LIGHT SNOW/FLURRIES HAS PUSHED EAST OF THE I-55 CORRIDOR
INTO EAST CENTRAL ILLINOIS...AND WILL PUSH INTO INDIANA WITHIN
THE NEXT FEW HOURS. A CLEARING LINE IS SINKING TOWARD THE AREA
FROM THE UPPER MIDWEST/WESTERN GREAT LAKES...AND THIS CLEARING
SHOULD SPREAD FROM NORTHWEST TO SOUTHEAST OVERNIGHT INTO EARLY
FRIDAY. THIS CLEARING WILL QUICKLY BE FOLLOWED BY A RIDGE OF HIGH
PRESSURE...PROVIDING QUIET WEATHER LOCALLY FOR THE HOLIDAY
WEEKEND.
GOING FORECAST IS IN GOOD SHAPE OVERALL. ONLY PLAN ON FEW MINOR
TWEAKS FOR THE LATEST AND EXPECTED OVERNIGHT TRENDS.
BAK
&&
.AVIATION...
ISSUED 1131 PM CST THU DEC 22 2011
LIGHT SNOW/FLURRIES HAVE SHIFTED EAST OF THE CENTRAL ILLINOIS
TERMINALS THIS EVENING...AND CLEARING IS APPROACHING FROM THE
NORTHWEST MORE QUICKLY THAN PREVIOUSLY ANTICIPATED. WITH THIS
TREND IN MIND...HAVE SKIES SCATTERING OUT...YIELDING VFR
CONDITIONS...IN THE NEXT FEW HOURS. THESE VFR CONDITION SHOULD
LINGER FOR THE DURATION OF THE 06Z TAF VALID TIME AS A RIDGE OF
HIGH PRESSURE PUSHES THROUGH THE REGION AT THE SURFACE. AN UPPER
LEVEL DISTURBANCE DIVING THROUGH THE GREAT LAKES BY LATE FRIDAY
SHOULD RESULT IN INCREASING MID LEVEL CLOUDINESS...BUT NO
PRECIPITATION IS ANTICIPATED.
BAK
&&
.PREV DISCUSSION...
ISSUED 225 PM CST THU DEC 22 2011
19Z SFC MAP INDICATED WEAK FRONT WASHING OUT NEAR I-57 WITH LIGHT
NORTHERLY BEHIND IT. MAIN WEATHER SYSTEM ACROSS THE COUNTRY WAS
LOCATED WELL TO OUR SOUTHEAST...HOWEVER STRATIFORM RAIN SHIELD
REACHED AS FAR NORTH AS THE OHIO VALLEY...AND CLOUDS ASSOCIATED WITH
THIS FEATURE OVERSPREAD THE ENTIRE AREA. BEYOND THIS EVENING...LITTLE IN
THE WAY OF FORECAST CONCERNS WITH A DRY AND MILD PATTERN PERSISTING
THROUGH MUCH OF NEXT WEEK.
SHORT TERM...TONIGHT AND FRIDAY
A COUPLE ITEMS OF INTEREST THIS EVENING. FIRST...NORTHERN FRINGE OF
OH VALLEY RAINS LOOK TO STAY JUST SOUTHEAST OF THE LAWRENCEVILLE
AREA IN REGION OF BETTER LIFT AND MOISTURE...BUT MAY INSERT LOW CHC POPS
IN THE FAR SE BASED ON LATEST RADAR TRENDS. OTHER ITEM IS RIBBON
OF 850-700 MB FRONTOGENESIS SLIDING SE INTO NRN MO/SE IA
CURRENTLY. RADAR MOSAIC INDICATES LIGHT SNOW BAND DEVELOPING FROM
KMCI TO NEAR KIRK IN MO. LATEST RUN OF HRRR AND 12KM NAM STREAK
THIS BAND TO THE EAST...ACROSS PARTS OF CENTRAL ILLINOIS THIS
EVENING. AIRMASS IS FAIRLY DRY...SO BELIEVE MOST PRECIP GENERATION
WILL BE EATEN BY SATURATION PROCESSES. HOWEVER SOME SCATTERED
FLURRIES OR BRIEF PERIODS OF LIGHT SNOW LOOK POSSIBLE FOR ROUGHLY
THE NW HALF BEFORE FRONTOGENESIS WANES AFTER MIDNIGHT. AS THE MAIN
SYNOPTIC WEATHER FEATURES SHIFT FARTHER EAST TOMORROW...HIGH
PRESSURE WILL BEGIN TO NOSE EAST FROM THE CENTRAL PLAINS. THIS
WILL ALLOW SKIES TO CLEAR FROM WEST TO EAST FOR A WELCOME RETURN
TO SUNSHINE.
LONG TERM...SATURDAY THROUGH THURSDAY
AS HAS BEEN THE CASE MUCH OF THIS EARLY WINTER...SPLIT FLOW JET
STREAM PATTERN WILL DOMINATE THE EXTENDED PORTION OF THE FORECAST.
THIS WILL KEEP ANY ARCTIC AIR BOTTLED UP IN CANADA...AND ANY
MOISTURE-RICH SHORTWAVES WELL TO OUR SOUTH. THIS PATTERN IS
CONSISTENT WITH POSITIVE PHASES OF THE AO AND NAO...AND THESE ARE
FORECAST TO STAY POSITIVE FOR THE NEXT COUPLE WEEKS.
THE HOLIDAY WEEKEND WILL FEATURE EXCELLENT TRAVEL
CONDITIONS...WITH THE CLOSEST PRECIPITATION BEING LAKE EFFECT AND
CLIPPER SNOW FOR THE GREAT LAKES...AND RAIN FROM THE LOWER
MISSISSIPPI VALLEY INTO THE DEEP SOUTH. FOR THE LOCAL
AREA...MOSTLY CLEAR SKIES AND TEMPERATURES RUNNING 5-10 DEGREES
ABOVE NORMAL WILL DOMINATE...WITH ANY CLIPPERS STAYING WELL TO OUR
NORTHEAST. THERE IS SOME MODEL DISAGREEMENT MONDAY NIGHT...WHEN A
SOUTHERN STREAM SHORTWAVE LIFTS INTO THE MS VALLEY. PREVIOUS
GUIDANCE AND THE CURRENT GFS KEEP ANY RAIN WITH THIS FEATURE WELL
SOUTH OF THE AREA...WHILE THE LATEST ECMWF AND GEM BRING RAIN OR A
RAIN/SNOW MIX UP TO THE LOWER GREAT LAKES BY TUESDAY MORNING. FOR
NOW WILL BASE THE FORECAST ON THE MORE CONSISTENT/DRY SOLUTION BUT
KEEP AN EYE ON THIS PERIOD FOR POP ADJUSTMENT. BEYOND THIS
POTENTIAL SYSTEM...ZONAL UPPER LEVEL FLOW WILL PRODUCE DRY AND
SEASONABLY WARM WEATHER THROUGH MID-WEEK.
25
&&
.ILX WATCHES/WARNINGS/ADVISORIES...
NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
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..
&&
.AVIATION...
A FAST MOVING STORM SYSTEM MOVING ACROSS MN...WI INTO THE GREAT
LAKES WAS PRODUCING BRISK SW WINDS AND DENSE MID AND HIGH LEVEL
CLOUD COVER INTO THIS EVENING. ACCUMULATING SNOW AND IFR CONDITIONS
WILL REMAIN NORTHEAST OF FORECAST TERMINALS...BUT THERE IS A
POTENTIAL THAT FLURRIES MAY BRIEFLY AFFECT THE DBQ SITE BETWEEN 21Z
AND 23Z. OTHERWISE...VFR CONDITIONS AND CLEARING SKIES WILL
PREVAIL TONIGHT THROUGH FRIDAY WITH BRISK SW WINDS DIMINISHING TO
LESS THAN 10 KTS AND BECOMING WESTERLY OVERNIGHT. ..SHEETS..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
SHEETS/08
AREA FORECAST DISCUSSION
NWS QUAD CITIES IA IL
1141 PM CST THU DEC 22 2011
.AVIATION...
HIGH PRESSURE BUILDING INTO THE PLAINS IS BRINGING COLDER...DRIER
AIR INTO THE LOCAL AREA THIS EVENING. EXPECT CLEAR TO MOSTLY
CLEAR SKIES WITH VISIBILITIES AOA 7 MILES WITH NW TO NORTH WINDS
OF 5 TO 10 MPH BECOMING SOUTHWEST BY LATE MORNING FRIDAY.
.NICHOLS..
&&
.PREV DISCUSSION... /ISSUED 321 PM CST THU DEC 22 2011/
SYNOPSIS...
SURFACE ANALYSIS AT 18Z SHOWED THE COLD FRONT THAT MOVED THROUGH
OVERNIGHT STRETCHED FROM NE TX ACROSS FAR SOUTHERN IL TO LOWER MI.
A 1032 HIGH WAS BUILDING INTO SD AND NE WITH A RESULTING TIGHT
PRESSURE GRADIENT ACROSS IA PRODUCING 15 TO 20 KT NORTHERLY WINDS
OVER MUCH OF THE FORECAST AREA. SATELLITE IMAGES INDICATED THE
BACK EDGE OF THE SOUTHWARD RETREATING STRATUS DECK REACHING FROM
KOTM TO NEAR GALENA. A NARROWER...MORE CONVECTIVE LOOKING CLOUD
DECK WITH MVFR BASES WAS FURTHER NORTH ACROSS NE IA INTO
WI...SHOWING SINGS OF SHRINKING AS IT WAS ADVANCING SLOWLY
SOUTHWARD. FURTHER SOUTH...AREA RADARS SHOWED AN EXPANDING BAND OF
REFLECTIVITY FROM KIRKSVILLE TO THE QUAD CITIES...LIKELY
ASSOCIATED WITH A WEAK MID LEVEL VORT MOVING THROUGH THE AREA AND
THE DEPARTING 300 MB JET CORE. 12Z ANALYSIS REVEALED THIS JET MAX
EMBEDDED IN THE UPPER LEVEL SW FLOW AHEAD OF A NORTHERN STREAM
TROUGH FROM HUDSON BAY SE INTO NEB AND A SEPARATE...MORE
CUTOFF...MID AND UPPER LEVEL CIRCULATION OVER SOUTHERN UT.
SHORT TERM...TONIGHT AND FRIDAY...
INITIAL CONCERN IS THE POTENTIAL FOR VERY LIGHT SNOW OR FLURRIES
OVER THE NEXT SEVERAL HOURS...THEN FOCUS TURNS TO OVERNIGHT LOW
TEMPERATURES. THE EXPANDING AND INCREASING BAND OF LIGHT SNOW
MENTIONED IN THE SYNOPSIS OVER THE SOUTH HAS RECENTLY BEGUN SHOWING
UP WITH GENERALLY 1 TO 4SM -SN ALONG THE MS RIVER SOUTH OF
MUSCATINE. BASED ON VSBYS AND RADAR TRENDS...COULD SEE A QUICK
DUSTING TO POSSIBLE 1/2 INCH BEFORE THE MID LEVEL FORCING...WHICH
THE LATEST RUC AND NAM12 HAVE A ROUGH HANDLE ON...QUICKLY PUSHES
EAST BEFORE 00Z. HAVE THUS INCREASED A SMALL AREA TO LIKELY POPS FOR
LATE AFTERNOON FOR ALONG AND EAST OF THE MS RIVER SOUTH OF THE QUAD CITIES
INTO IL.
OVERNIGHT...HIGH PRESSURE RIDGE EXTENDING W-NW FROM THE HIGH PLAINS
HIGH...ALONG WITH MID LEVEL SUBSIDENCE BEHIND THE SHORTWAVE PASSING
TO THE NORTH SHOULD PUSH THE LOW CLOUDS SOUTH OF THE AREA BY
MIDNIGHT. CLEARING SKIES AND LIGHT WINDS SHOULD RESULT IN THE
COLDEST NIGHT IN SEVERAL DAYS...AND BASED ON TRAJECTORIES...LOWS
CLOSE TO GUIDANCE BLEND FROM AROUND 15 NORTH TO LOWER 20S SOUTH LOOK
REASONABLE. FRIDAY...SUNSHINE...LACK OF SNOW COVER...AND RETURN FLOW
SOUTHWEST WINDS WILL ALLOW TEMPERATURES TO RECOVER WELL INTO THE
30S. ..SHEETS..
LONG TERM...FRIDAY NIGHT THROUGH NEXT THURSDAY...
THE EXTENDED FORECAST REMAINS DOMINATED BY MOSTLY BENIGN NORTHWEST
FLOW FRONTAL PASSAGES. THIS NORMALLY REPRESENTS A BELOW NORMAL
FORECAST FOR TEMPERATURES...BUT WITH SPLIT FLOW...THIS SHOULD KEEP
TEMPERATURES GENERALLY ABOVE NORMAL...AND ALSO WILL KEEP POPS VERY
LOW. THERE REMAINS TWO POTENTIAL POP CHANCES IN THE EXTENDED...BUT
BOTH ARE POORLY SHOWN WITH RESPECT TO CONSISTENCY IN ANY ONE MODEL
RUN. THE FIRST...MONDAY AND MONDAY NIGHT... THE MODEL BLEND KEEPS
THE FORECAST DRY AS THE GFS CONTINUES TO SHOW A CLIPPER PASSING WELL
NORTH OF THE CWA....RESULTING IN DRY WAA DAY. HOWEVER...THE ECMWF
AND CANADIAN BOTH BRING THE CUT OFF LOW FROM THE SOUTHWEST UP OVER
THE CWA MONDAY AND MONDAY NIGHT...RESULTING IN POTENTIAL RAIN OR
SNOW. FOR NOW...HAVE BUMPED UP POPS TO 10 TO 14 PERCENT AND SKY
COVER AS WELL...BUT LEFT DRY.
AFTER SEVERAL MORE DAYS OF BENIGN NORTHWEST FLOW...MODELS SHOW
ANOTHER BROAD TROF MOVING PAST THE REGION AROUND FRIDAY. THIS WAVE
INITIALIZED WITH SLIGHT TO LOW CHANCE POPS FOR SNOW.
TEMPERATURES THROUGHOUT THE FORECAST ARE GENERALLY FROM THE MID 30S
TO MID 40S...WITH LOWS IN THE MID 20S TO LOWER 30S. SUCH
TEMPERATURES ARE VERY MILD FOR THE SHORTEST DAYS OF THE YEAR.
ERVIN..
&&
.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&
$$
WDN
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1031 AM MST FRI DEC 23 2011
.UPDATE...
317 AM MST FRI DEC 23 2011
IR AND 11-3.9 SATELLITE IMAGES SHOW PATCHY FOG MOVING ACROSS PARTS
OF CHEYENNE COUNTY COLORADO. LIMON DID HAVE SOME BRIEF REDUCTIONS IN VISIBILITY
DOWN TO A QUARTER...BUT LOOKS LIKE THE FOG IS NOT THAT DENSE OVER
CHEYENNE COUNTY. LATEST VSREF AND HRRR SHOW IT MAY MOVE INTO PARTS
OF WALLACE AND GREELEY COUNTY SO WILL INCLUDE THESE THREE COUNTIES
IN A MENTION OF PATCHY FREEZING FOG. THE FREEZING FOG SHOULD
DISSIPATE BY MID MORNING.
JTL
&&
.SHORT TERM (TODAY-CHRISTMAS DAY)...
227 AM MST FRI DEC 23 2011
RATHER TRANQUIL WEATHER WILL BE IN STORE FOR THE TRI-STATE AREA FOR
THE CHRISTMAS WEEKEND. AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL
REMAIN OVER THE AREA DURING THE PERIOD. LATE IN THE PERIOD AN UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH THE PERIPHERY OF THE RIDGE.
WITH MOST OF THE JET ENERGY NORTH OF THE AREA AND A DRY ENVIRONMENT
IN PLACE...WILL CONTINUE TO LEAVE CHRISTMAS NIGHT DRY.
HIGH TEMPERATURES WILL BE NORMAL TO ABOVE NORMAL THROUGH THE PERIOD
AS WARMER 850MB AIR IS BROUGHT IN BY THE NORTHWEST WINDS. LOW
TEMPERATURES WILL BE NEAR NORMAL TO BELOW NORMAL FOR TONIGHT THEN
WARM TO EITHER NEAR NORMAL OR ABOVE NORMAL VALUES FOR THE WEEKEND.
SOME UNCERTAINTY EXISTS REGARDING THE EFFECT THE RECENT SNOWFALL
FROM EARLIER THIS WEEK WILL HAVE ON TEMPERATURES. GENERAL TREND WAS
TO HAVE COOLER TEMPERATURES OVER THE SOUTHERN AND SOUTHEASTERN AREAS
WHERE THE HIGHEST SNOWFALL AMOUNTS WERE REPORTED.
JTL
.LONG TERM (MONDAY-THURSDAY)...
227 AM MST FRI DEC 23 2011
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
&&
.AVIATION...
1029 AM MST FRI DEC 23 2011
VFR CONDITIONS EXPECTED FROM TODAY THROUGH TONIGHT AND SATURDAY
AT KMCK AND KGLD. HIGH PRESSURE WILL REMAIN IN PLACE WITH LIGHT
WEST WINDS TURNING SLIGHTLY MORE NORTHWEST.
LOCKHART
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
425 AM MST FRI DEC 23 2011
.UPDATE...
317 AM MST FRI DEC 23 2011
IR AND 11-3.9 SATELLITE IMAGES SHOW PATCHY FOG MOVING ACROSS PARTS
OF CHEYENNE COUNTY COLORADO. LIMON DID HAVE SOME BRIEF REDUCTIONS IN VISIBILITY
DOWN TO A QUARTER...BUT LOOKS LIKE THE FOG IS NOT THAT DENSE OVER
CHEYENNE COUNTY. LATEST VSREF AND HRRR SHOW IT MAY MOVE INTO PARTS
OF WALLACE AND GREELEY COUNTY SO WILL INCLUDE THESE THREE COUNTIES
IN A MENTION OF PATCHY FREEZING FOG. THE FREEZING FOG SHOULD
DISSIPATE BY MID MORNING.
JTL
&&
.SHORT TERM (TODAY-CHRISTMAS DAY)...
227 AM MST FRI DEC 23 2011
RATHER TRANQUIL WEATHER WILL BE IN STORE FOR THE TRI-STATE AREA FOR
THE CHRISTMAS WEEKEND. AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL
REMAIN OVER THE AREA DURING THE PERIOD. LATE IN THE PERIOD AN UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH THE PERIPHERY OF THE RIDGE.
WITH MOST OF THE JET ENERGY NORTH OF THE AREA AND A DRY ENVIRONMENT
IN PLACE...WILL CONTINUE TO LEAVE CHRISTMAS NIGHT DRY.
HIGH TEMPERATURES WILL BE NORMAL TO ABOVE NORMAL THROUGH THE PERIOD
AS WARMER 850MB AIR IS BROUGHT IN BY THE NORTHWEST WINDS. LOW
TEMPERATURES WILL BE NEAR NORMAL TO BELOW NORMAL FOR TONIGHT THEN
WARM TO EITHER NEAR NORMAL OR ABOVE NORMAL VALUES FOR THE WEEKEND.
SOME UNCERTAINTY EXISTS REGARDING THE EFFECT THE RECENT SNOWFALL
FROM EARLIER THIS WEEK WILL HAVE ON TEMPERATURES. GENERAL TREND WAS
TO HAVE COOLER TEMPERATURES OVER THE SOUTHERN AND SOUTHEASTERN AREAS
WHERE THE HIGHEST SNOWFALL AMOUNTS WERE REPORTED.
JTL
.LONG TERM (MONDAY-THURSDAY)...
227 AM MST FRI DEC 23 2011
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
&&
.AVIATION...
425 AM MST FRI DEC 23 2011
FOR THE 12Z TAFS...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD AT
BOTH TERMINALS. HIGH PRESSURE WILL MOVE FROM THE CENTRAL TO SOUTHERN
HIGH PLAINS RESULTING IN MOSTLY CLEAR SKIES AND LIGHT WEST WINDS.
024
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
325 AM MST FRI DEC 23 2011
.UPDATE...
317 AM MST FRI DEC 23 2011
IR AND 11-3.9 SATELLITE IMAGES SHOW PATCHY FOG MOVING ACROSS PARTS
OF CHEYENNE COUNTY COLORADO. LIMON DID HAVE SOME BRIEF REDUCTIONS IN VISIBILITY
DOWN TO A QUARTER...BUT LOOKS LIKE THE FOG IS NOT THAT DENSE OVER
CHEYENNE COUNTY. LATEST VSREF AND HRRR SHOW IT MAY MOVE INTO PARTS
OF WALLACE AND GREELEY COUNTY SO WILL INCLUDE THESE THREE COUNTIES
IN A MENTION OF PATCHY FREEZING FOG. THE FREEZING FOG SHOULD
DISSIPATE BY MID MORNING.
JTL
&&
.SHORT TERM (TODAY-CHRISTMAS DAY)...
227 AM MST FRI DEC 23 2011
RATHER TRANQUIL WEATHER WILL BE IN STORE FOR THE TRI-STATE AREA FOR
THE CHRISTMAS WEEKEND. AN UPPER LEVEL RIDGE OF HIGH PRESSURE WILL
REMAIN OVER THE AREA DURING THE PERIOD. LATE IN THE PERIOD AN UPPER
LEVEL SHORT WAVE TROUGH WILL MOVE THROUGH THE PERIPHERY OF THE RIDGE.
WITH MOST OF THE JET ENERGY NORTH OF THE AREA AND A DRY ENVIRONMENT
IN PLACE...WILL CONTINUE TO LEAVE CHRISTMAS NIGHT DRY.
HIGH TEMPERATURES WILL BE NORMAL TO ABOVE NORMAL THROUGH THE PERIOD
AS WARMER 850MB AIR IS BROUGHT IN BY THE NORTHWEST WINDS. LOW
TEMPERATURES WILL BE NEAR NORMAL TO BELOW NORMAL FOR TONIGHT THEN
WARM TO EITHER NEAR NORMAL OR ABOVE NORMAL VALUES FOR THE WEEKEND.
SOME UNCERTAINTY EXISTS REGARDING THE EFFECT THE RECENT SNOWFALL
FROM EARLIER THIS WEEK WILL HAVE ON TEMPERATURES. GENERAL TREND WAS
TO HAVE COOLER TEMPERATURES OVER THE SOUTHERN AND SOUTHEASTERN AREAS
WHERE THE HIGHEST SNOWFALL AMOUNTS WERE REPORTED.
JTL
.LONG TERM (MONDAY-THURSDAY)...
227 AM MST FRI DEC 23 2011
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
&&
.AVIATION...
951 PM MST THU DEC 22 2011
FOR THE 06Z TAFS...VFR CONDITIONS ARE EXPECTED TO PREVAIL THROUGH
THE PERIOD AT BOTH TERMINALS. LIGHT WINDS HAVE BACKED THROUGHOUT
THE EVENING...AND WILL BACK SLIGHTLY MORE EARLY IN THE PERIOD AND
BECOME SOUTHWESTERLY. WEST OF KGLD IN COLORADO...THERE IS THE
POTENTIAL FOR FOG OVER THE AREAS THAT RECEIVED SEVERAL INCHES OF
SNOW OVER THE PAST 24 HOURS. AT KGLD...DEW POINTS SHOULD CONTINUE
TO DECREASE AND KEEP VISIBILITIES VFR. WINDS WILL CONTINUE TO BE
LIGHT DURING THE DAYTIME ON FRIDAY...VEERING SLIGHTLY TO WESTERLY.
CJS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
947 PM EST SAT DEC 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION TONIGHT AND SHIFT OFFSHORE.
A WEAK WARM FRONT WILL APPROACH FROM THE SOUTHWEST ON SUNDAY AHEAD
OF LOW PRESSURE MOVING OUT OF THE GREAT LAKES. LOW PRESSURE WILL
CROSS THE AREA SUNDAY NIGHT DRAGGING A COLD FRONT THROUGH THE AREA.
HIGH PRESSURE WILL BUILD INTO THE AREA ON MONDAY AND WILL SHIFT
OFFSHORE MONDAY NIGHT. A COLD FRONT WILL MOVE TOWARD THE REGION FROM
THE NORTHWEST ON TUESDAY AND WILL STALL OVER NEW ENGLAND TUESDAY
NIGHT AS LOW PRESSURE MOVES UP THE EAST COAST. LOW PRESSURE WILL
TRACK SOUTH OF NEW ENGLAND AND INTO THE MARITIMES ON WEDNESDAY. HIGH
PRESSURE WILL BUILD OVER THE AREA WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
UPDATE...OCEAN EFFECT CLOUDS ARE DEVELOPING OFF THE SEACOAST
ATTM...WITH CLOUD TOPS COOLING QUICKLY OVER THE LAST HR. WEAK
ECHOES ALSO BECOMING EVIDENT ON BOTH THE KGYX AND KBOX 88D. HAVE
MOVED POP SLIGHTLY TO ACCOUNT FOR THESE TRENDS...BUT FCST REMAINS
ON TRACK FOR TNGT.
PREVIOUS DISCUSSION...ALSO WATCHING THE POTENTIAL FOR OCEAN
EFFECT SHSN TO DEVELOP FOR THE SEACOAST AROUND MIDNIGHT. SSTS
AROUND +8C WITH H85 TEMPS RUNNING AROUND -13C ARE PROVIDING FOR
SOME PRETTY GOOD DELTA T VALUES. AS WINDS VEER LATE THIS
EVE...ONSHORE FLOW WILL DEVELOP FOR THE SEACOAST...AND WOULD NOT
BE SURPRISED TO SEE SHSN MOVE ONSHORE AS WELL. 12Z GFS HAD LATCHED
ONTO THIS IDEA...AND WHILE THE NAM HAD NO QPF FOR THE AREA WEAK
OMEGA WAS INDICATED AT THE BOTTOM OF THE SATURATED SNOW GROWTH
ZONE IN BUFKIT PROFILES. HRRR SUPPORTS A FEW HRS OF SHSN AS
WELL...WITH A DUSTING TO A HALF INCH ACCUM PSBL. HAVE UPPED POP TO
CHC CENTERED ON THE BEST PARAMETERS AND TRENDED EITHER SIDE FROM
THERE. FLOW BECOME DISORGANIZED VERY EARLY SUN...BEFORE ONSHORE
FLOW BECOMES ENHANCED ALONG MIDCOAST.
STRONG SURFACE HIGH PRESSURE WILL CREST OVER THE REGION
TONIGHT...THEN MOVE OFFSHORE LATE. INITIAL CLEAR CALM CONDITIONS
WITH SNOW COVER IN MOST AREAS WILL ALLOW TEMPERATURES TO FALL VERY
QUICKLY. INCREASING CIRRUS LATER ON WILL PROBABLY SLOW DOWN THE
TEMP DROPS...BUT PROBABLY NOT BEFORE GUIDANCE MINS ARE MET. EXPECT
THE GOOD RADIATORS TO DROP TO AROUND ZERO...AND THE BEST RADIATORS
DROP BELOW.
&&
.SHORT TERM /SUNDAY NIGHT/...
A WAA REGIME WILL GET GOING SUNDAY MORNING AS HIGH PRESSURE MOVES
OFFSHORE AND A SHORT WAVE TROUGH APPROACHES FROM THE WEST. MAY
ACTUALLY SEE SOME LIGHT OCEAN EFFECT SNOWS ON THE MID COAST BY
LATE MORNING.
DURING THE AFTERNOON...LARGE SCALE FORCING FOR ASCENT WILL
COMMENCE AS THE COLUMN MOISTENS UP. THIS SHOULD ALLOW FOR SOME
LIGHT SNOW TO DEVELOP ACROSS A GOOD PORTION OF THE AREA. ACCUMS
WON/T BE MUCH...PROBABLY A DUSTING TO AN INCH DURING THE
DAY...PERHAPS A TOUCH MORE IN LINCOLN...KNOX...AND WALDO COUNTIES
IN MAINE DUE TO OCEAN ENHANCEMENT. I SUPPOSE THE NH COAST AND THE
REST OF THE MAINE COAST COULD SEE SOME OF THIS TOO WHILE THE WINDS
ARE E/SE...BUT LESS CONFIDENCE THERE. SOMETHING TO WATCH LATE
TONIGHT AND EARLY TOMORROW MORNING THOUGH.
THE STRONG SHORT WAVE TROUGH WILL BE KNOCKING ON OUR DOOR SUNDAY
EVENING...AND WILL MOVE OVERHEAD OVERNIGHT. STABILITY DECREASES AS
THIS HAPPENS...AS TOTAL TOTAL INDICES RISE WELL INTO THE 50S. AS
THIS HAPPENS...WE EXPECT AT LEAST SCATTERED SNOW
SQUALLS TO DEVELOP...ESPECIALLY AS WE MOVE TOWARD LATE EVENING
AND MIDNIGHT. THESE SQUALLS COULD PUT DOWN A QUICK INCH OR TWO AND
CAUSE LOCALLY HAZARDOUS DRIVING CONDITIONS.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL GRADUALLY BUILD OVER THE REGION ON MONDAY AS LOW
PRESSURE PULLS AWAY TO THE EAST. EXPECT MOSTLY CLOUDY SKIES MONDAY
MORNING TO GIVE WAY TO SUNSHINE IN THE AFTERNOON WITH VARIABLE
CLOUDS LINGERING IN THE MOUNTAINS. LOOKING FOR HIGHS FROM THE MID
20S NORTH TO THE MID 30S SOUTH.
HIGH PRESSURE WILL SHIFT OFFSHORE MONDAY EVENING WITH RETURN FLOW
PUMPING WARMER AIR BACK INTO THE REGION OVERNIGHT. WARM FRONT
CROSSING SOUTHERN CANADA WILL BRING VARIABLE HIGH CLOUDS OVERNIGHT
BUT EXPECT ANY SNOW SHOWER ACTIVITY GENERALLY REMAIN NORTH OF THE
FORECAST AREA.
A COLD FRONT APPROACHING FROM THE NORTHWEST WILL BRING INCREASING
CLOUDS AND A CHANCE OF RAIN OR SNOW SHOWERS TO THE REGION ON
TUESDAY. SHORTWAVE LIFTING NORTHEAST OUT OF THE OHIO VALLEY WILL
TRACK NORTHEAST ALONG THIS BOUNDARY AS IT STALLS OVER NEW ENGLAND
TUESDAY NIGHT. GFS NOW IN WITH A MUCH COLDER SOLUTION WITH LOW
PRESSURE SOUTH OF NEW ENGLAND TUESDAY NIGHT...MOVING INTO THE
MARITIMES ON WEDNESDAY. WILL LIKELY SEE SOME ADJUSTMENTS TO TIMING
AND TRACK THROUGH THE WEEKEND SO NOT JUMPING ON THE LATEST GUIDANCE
AT THIS POINT...BUT DOES APPEAR LIKELY WE`LL SEE SOME SIGNIFICANT
PRECIPITATION TUESDAY NIGHT AND WEDNESDAY.
LOW PRESSURE FORECAST TO SHIFT INTO THE MARITIMES WEDNESDAY NIGHT AS
HIGH PRESSURE BUILDS IN FROM THE WEST. WILL SEE PRECIPITATION ENDING
AND CLEARING SKIES WEDNESDAY AFTERNOON...SETTING UP A CLEAR AND
CHILLY NIGHT.
HIGH PRESSURE WILL HOLD OVER THE REGION ON THURSDAY WITH MOSTLY
SUNNY SKIES AND LIGHT WINDS ALONG WITH SEASONABLE TEMPS.
NEXT SHORTWAVE APPROACHES FROM THE WEST ON FRIDAY BRINGING
INCREASING CLOUDS AND A CHANCE OF SNOW FOR SOUTHERN AREAS. LOW
PRESSURE WILL FADE OVER THE GREAT LAKES AS A SECONDARY AREA OF LOW
PRESSURE DEVELOPS SOUTH OF NEW ENGLAND AND LIFTS NORTHEAST. AT THIS
POINT LOOKS LIKE THE BULK OF THE QPF FALLS OUT ACROSS SOUTHERN NEW
ENGLAND AND OFFSHORE...BUT PLENTY OF TIME FOR CHANGES.
&&
.AVIATION /03Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR TONIGHT THROUGH MUCH OF SUNDAY MORNING. LOCALLY
LOWER CONDITIONS MAY DEVELOP ON THE COAST DURING THE MORNING DUE
TO SNOW SHOWERS. SNOW SQUALLS MAY BRIEFLY REDUCE VSBYS TO BELOW
1/2 MILE SUNDAY EVENING.
LONG TERM...VFR MONDAY THROUGH TUESDAY. IFR/LIFR VSBY AND CEILINGS
DEVELOPING TUESDAY NIGHT...IMPROVING WEDNESDAY AFTERNOON. VFR
WEDNESDAY NIGHT AND THURSDAY.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS CONTINUE TO DIMINISH THIS EVENING WITH
HIGH PRESSURE BUILDING OVERHEAD. SWLY FLOW DEVELOPS SUNDAY
AFTERNOON AND EVENING...AND WILL LIKELY GUST TO AROUND 30 KT WITH
BUILDING SEAS. THEREFORE...A SCA HAS BEEN ISSUED TO COVER THIS.
LONG TERM...SCA WINDS LIKELY MONDAY...DIMINISHING IN THE
AFTERNOON. GALES POSSIBLE LATE TUESDAY NIGHT INTO WEDNESDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM SUNDAY TO 5 AM EST MONDAY FOR
ANZ150>154.
&&
$$
LEGRO
AREA FORECAST DISCUSSION...UPDATED
NWS GRAY ME
722 PM EST SAT DEC 24 2011
.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION TONIGHT AND SHIFT OFFSHORE.
A WEAK WARM FRONT WILL APPROACH FROM THE SOUTHWEST ON SUNDAY AHEAD
OF LOW PRESSURE MOVING OUT OF THE GREAT LAKES. LOW PRESSURE WILL
CROSS THE AREA SUNDAY NIGHT DRAGGING A COLD FRONT THROUGH THE AREA.
HIGH PRESSURE WILL BUILD INTO THE AREA ON MONDAY AND WILL SHIFT
OFFSHORE MONDAY NIGHT. A COLD FRONT WILL MOVE TOWARD THE REGION FROM
THE NORTHWEST ON TUESDAY AND WILL STALL OVER NEW ENGLAND TUESDAY
NIGHT AS LOW PRESSURE MOVES UP THE EAST COAST. LOW PRESSURE WILL
TRACK SOUTH OF NEW ENGLAND AND INTO THE MARITIMES ON WEDNESDAY. HIGH
PRESSURE WILL BUILD OVER THE AREA WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /THROUGH SUNDAY/...
UPDATE...INPUT CURRENT OBS TO KEEP TEMPS ON TRACK...AS THEY
CONTINUE TO RUN BLO GUIDANCE AND SLIGHTLY BLO FCST ATTM.
PREVIOUS DISCUSSION...ALSO WATCHING THE POTENTIAL FOR OCEAN
EFFECT SHSN TO DEVELOP FOR THE SEACOAST AROUND MIDNIGHT. SSTS
AROUND +8C WITH H85 TEMPS RUNNING AROUND -13C ARE PROVIDING FOR
SOME PRETTY GOOD DELTA T VALUES. AS WINDS VEER LATE THIS
EVE...ONSHORE FLOW WILL DEVELOP FOR THE SEACOAST...AND WOULD NOT
BE SURPRISED TO SEE SHSN MOVE ONSHORE AS WELL. 12Z GFS HAD LATCHED
ONTO THIS IDEA...AND WHILE THE NAM HAD NO QPF FOR THE AREA WEAK
OMEGA WAS INDICATED AT THE BOTTOM OF THE SATURATED SNOW GROWTH
ZONE IN BUFKIT PROFILES. HRRR SUPPORTS A FEW HRS OF SHSN AS
WELL...WITH A DUSTING TO A HALF INCH ACCUM PSBL. HAVE UPPED POP TO
CHC CENTERED ON THE BEST PARAMETERS AND TRENDED EITHER SIDE FROM
THERE. FLOW BECOME DISORGANIZED VERY EARLY SUN...BEFORE ONSHORE
FLOW BECOMES ENHANCED ALONG MIDCOAST.
STRONG SURFACE HIGH PRESSURE WILL CREST OVER THE REGION
TONIGHT...THEN MOVE OFFSHORE LATE. INITIAL CLEAR CALM CONDITIONS
WITH SNOW COVER IN MOST AREAS WILL ALLOW TEMPERATURES TO FALL VERY
QUICKLY. INCREASING CIRRUS LATER ON WILL PROBABLY SLOW DOWN THE
TEMP DROPS...BUT PROBABLY NOT BEFORE GUIDANCE MINS ARE MET. EXPECT
THE GOOD RADIATORS TO DROP TO AROUND ZERO...AND THE BEST RADIATORS
DROP BELOW.
&&
.SHORT TERM /SUNDAY NIGHT/...
A WAA REGIME WILL GET GOING SUNDAY MORNING AS HIGH PRESSURE MOVES
OFFSHORE AND A SHORT WAVE TROUGH APPROACHES FROM THE WEST. MAY
ACTUALLY SEE SOME LIGHT OCEAN EFFECT SNOWS ON THE MID COAST BY
LATE MORNING.
DURING THE AFTERNOON...LARGE SCALE FORCING FOR ASCENT WILL
COMMENCE AS THE COLUMN MOISTENS UP. THIS SHOULD ALLOW FOR SOME
LIGHT SNOW TO DEVELOP ACROSS A GOOD PORTION OF THE AREA. ACCUMS
WON/T BE MUCH...PROBABLY A DUSTING TO AN INCH DURING THE
DAY...PERHAPS A TOUCH MORE IN LINCOLN...KNOX...AND WALDO COUNTIES
IN MAINE DUE TO OCEAN ENHANCEMENT. I SUPPOSE THE NH COAST AND THE
REST OF THE MAINE COAST COULD SEE SOME OF THIS TOO WHILE THE WINDS
ARE E/SE...BUT LESS CONFIDENCE THERE. SOMETHING TO WATCH LATE
TONIGHT AND EARLY TOMORROW MORNING THOUGH.
THE STRONG SHORT WAVE TROUGH WILL BE KNOCKING ON OUR DOOR SUNDAY
EVENING...AND WILL MOVE OVERHEAD OVERNIGHT. STABILITY DECREASES AS
THIS HAPPENS...AS TOTAL TOTAL INDICES RISE WELL INTO THE 50S. AS
THIS HAPPENS...WE EXPECT AT LEAST SCATTERED SNOW
SQUALLS TO DEVELOP...ESPECIALLY AS WE MOVE TOWARD LATE EVENING
AND MIDNIGHT. THESE SQUALLS COULD PUT DOWN A QUICK INCH OR TWO AND
CAUSE LOCALLY HAZARDOUS DRIVING CONDITIONS.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
HIGH PRESSURE WILL GRADUALLY BUILD OVER THE REGION ON MONDAY AS LOW
PRESSURE PULLS AWAY TO THE EAST. EXPECT MOSTLY CLOUDY SKIES MONDAY
MORNING TO GIVE WAY TO SUNSHINE IN THE AFTERNOON WITH VARIABLE
CLOUDS LINGERING IN THE MOUNTAINS. LOOKING FOR HIGHS FROM THE MID
20S NORTH TO THE MID 30S SOUTH.
HIGH PRESSURE WILL SHIFT OFFSHORE MONDAY EVENING WITH RETURN FLOW
PUMPING WARMER AIR BACK INTO THE REGION OVERNIGHT. WARM FRONT
CROSSING SOUTHERN CANADA WILL BRING VARIABLE HIGH CLOUDS OVERNIGHT
BUT EXPECT ANY SNOW SHOWER ACTIVITY GENERALLY REMAIN NORTH OF THE
FORECAST AREA.
A COLD FRONT APPROACHING FROM THE NORTHWEST WILL BRING INCREASING
CLOUDS AND A CHANCE OF RAIN OR SNOW SHOWERS TO THE REGION ON
TUESDAY. SHORTWAVE LIFTING NORTHEAST OUT OF THE OHIO VALLEY WILL
TRACK NORTHEAST ALONG THIS BOUNDARY AS IT STALLS OVER NEW ENGLAND
TUESDAY NIGHT. GFS NOW IN WITH A MUCH COLDER SOLUTION WITH LOW
PRESSURE SOUTH OF NEW ENGLAND TUESDAY NIGHT...MOVING INTO THE
MARITIMES ON WEDNESDAY. WILL LIKELY SEE SOME ADJUSTMENTS TO TIMING
AND TRACK THROUGH THE WEEKEND SO NOT JUMPING ON THE LATEST GUIDANCE
AT THIS POINT...BUT DOES APPEAR LIKELY WE`LL SEE SOME SIGNIFICANT
PRECIPITATION TUESDAY NIGHT AND WEDNESDAY.
LOW PRESSURE FORECAST TO SHIFT INTO THE MARITIMES WEDNESDAY NIGHT AS
HIGH PRESSURE BUILDS IN FROM THE WEST. WILL SEE PRECIPITATION ENDING
AND CLEARING SKIES WEDNESDAY AFTERNOON...SETTING UP A CLEAR AND
CHILLY NIGHT.
HIGH PRESSURE WILL HOLD OVER THE REGION ON THURSDAY WITH MOSTLY
SUNNY SKIES AND LIGHT WINDS ALONG WITH SEASONABLE TEMPS.
NEXT SHORTWAVE APPROACHES FROM THE WEST ON FRIDAY BRINGING
INCREASING CLOUDS AND A CHANCE OF SNOW FOR SOUTHERN AREAS. LOW
PRESSURE WILL FADE OVER THE GREAT LAKES AS A SECONDARY AREA OF LOW
PRESSURE DEVELOPS SOUTH OF NEW ENGLAND AND LIFTS NORTHEAST. AT THIS
POINT LOOKS LIKE THE BULK OF THE QPF FALLS OUT ACROSS SOUTHERN NEW
ENGLAND AND OFFSHORE...BUT PLENTY OF TIME FOR CHANGES.
&&
.AVIATION /01Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR TONIGHT THROUGH MUCH OF SUNDAY MORNING. LOCALLY
LOWER CONDITIONS MAY DEVELOP ON THE COAST DURING THE MORNING DUE
TO SNOW SHOWERS. SNOW SQUALLS MAY BRIEFLY REDUCE VSBYS TO BELOW
1/2 MILE SUNDAY EVENING.
LONG TERM...VFR MONDAY THROUGH TUESDAY. IFR/LIFR VSBY AND CEILINGS
DEVELOPING TUESDAY NIGHT...IMPROVING WEDNESDAY AFTERNOON. VFR
WEDNESDAY NIGHT AND THURSDAY.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS CONTINUE TO DIMINISH THIS EVENING WITH
HIGH PRESSURE BUILDING OVERHEAD. SWLY FLOW DEVELOPS SUNDAY
AFTERNOON AND EVENING...AND WILL LIKELY GUST TO AROUND 30 KT WITH
BUILDING SEAS. THEREFORE...A SCA HAS BEEN ISSUED TO COVER THIS.
LONG TERM...SCA WINDS LIKELY MONDAY...DIMINISHING IN THE
AFTERNOON. GALES POSSIBLE LATE TUESDAY NIGHT INTO WEDNESDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM SUNDAY TO 5 AM EST MONDAY FOR
ANZ150>154.
&&
$$
LEGRO
AREA FORECAST DISCUSSION
NWS GRAY ME
1149 PM EST THU DEC 22 2011
.SYNOPSIS...
LOW PRESSURE WILL TRACK NORTHEAST FROM THE MID ATLANTIC STATES
OVERNIGHT, THEN PASS JUST SOUTH AND EAST OF THE GULF OF MAINE ON
FRIDAY. HIGH PRESSURE AND DRY AIR FOLLOWS FOR LATER SATURDAY INTO
CHRISTMAS DAY. A WEAK WARM FRONT COULD PRODUCE A FEW SNOW SHOWERS
ACROSS NORTHERN SECTIONS OF THE AREA LATE CHRISTMAS DAY. A COLD
FRONT WILL CROSS THE AREA EARLY MONDAY, WHILE AN OCEAN LOW PASSES
WELL SOUTH AND EAST OF THE AREA. HIGH PRESSURE WILL BUILD BY TO
OUR SOUTH LATE MONDAY INTO TUESDAY.
&&
.NEAR TERM /UNTIL 8 AM FRIDAY MORNING/...
1150 PM...I MADE MINOR ADJUSTMENTS TO 1ST PERIOD GRIDS. SOME
ADJUSTMENTS TO COASTAL FOR WIND DIRECTIONS WITH BOUNDARY DRAPED
ACROSS THE WATERS. MAY NEED A MARGINAL SCA OUTSIDE THE BAYS FOR
LATER TODAY INTO TONIGHT.
PREV DISC...
***HAVE ISSUED WINTER WEATHER ADVISORIES FOR MUCH OF SOUTHERN NH
(EXCEPT ROCKINGHAM COUNTY) AS WELL AS INTERIOR YORK COUNTY MAINE***
LOW LEVEL TEMPERATURES: FOR A COUPLE HOURS THIS
EVENING...TEMPERATURES TOOK A NOSEDIVE NORTH OF A LINE FROM ABOUT
LACONIA NH...EASTWARD TO SANFORD MAINE. JUST AFTER SUNSET...AN
AREA OF LOW CLOUDS DEVELOPED SOUTH OF THIS LINE...INHIBITING
FALLING TEMPERATURES WHILE CLEAR SKIES REMAINED TO THE NORTH.
SINCE THEN...THE LOW CLOUDS HAVE DISSIPATED...WITH JUST HIGH
CLOUDS STREAMING ACROSS CENTRAL AND NORTHERN AREAS. AT THIS
TIME...HAVE ADJUSTED TEMPERATURES DOWNWARDS BASED ON THE
DIFFERENCES LAST HOUR BETWEEN THE FORECAST DATABASE AND
OBSERVATIONS AS OF 01Z. DESPITE REMAINING IN THE UPPER 30S HERE AT
GYX (2M TEMPERATURE)...THE SIDEWALKS AND GRASSY SURFACES IN THE
AREA ARE BEGINNING TO FREEZE UP ALREADY.
00Z SOUNDING: EVENING SOUNDING AT GYX CONTINUES TO CONTAIN PLENTY
OF DRY AIR AVAILABLE FOR EVAPORATIONAL COOLING. LOW LEVEL
TEMPERATURES WERE VERY CLOSE TO PROGS...PERHAPS EVER SO SLIGHTLY COOLER.
QPF: IN ADDITION TO THE COOL BIAS OVERNIGHT OVER THE NORTHERN 2/3
OF THE FORECAST AREA...SHORT TERM MODELS ARE STEADILY COMING IN
WITH SLIGHTLY MORE QPF FROM RUN TO RUN. THE HRRR MODEL NOW SHOWS
STORM TOTAL QPF OVER .50 INCHES OVER ALL OF SOUTHERN NH AND IN
YORK COUNTY ME...WITH THE NEXT CLOSEST MODEL IN TERMS OF QPF BEING
THE WETTER EURO. 18Z GFS AND NAM HAVE NUDGED UPWARDS AS WELL...AND
WE ARE AWAITING THE NAM. 21Z SREF NOW SHOWS UP TO 70% LIKELIHOOD
OF 4"OR MORE OVER ALL OF SRN NH...EXTENDING INTO FAR WESTERN
MAINE.
SNOWFALL: BASED ON MUCH OF THE INFORMATION DISCUSSED ABOVE...WILL
BE ADJUSTING SNOWFALL ACCUMULATIONS SLIGHTLY UPWARDS FOR SOUTHERN
AND CENTRAL AREAS DURING THE NEXT HOUR - INTO THE 3 TO 6 INCH
RANGE. THE HIGHER TOTALS WILL BE IN THE HILLTOWNS. ALONG THE COAST...FROM
COASTAL YORK COUNTY AND PORTIONS SOUTH...THERE WILL STILL BE
BOUNDARY LAYER PROBLEMS WITH RAIN MIXING IN WITH TIMES. THIS WILL
KEEP ACCUMULATIONS DOWN...ESPECIALLY ALONG COASTAL ROCKINGHAM
COUNTY WHERE LITTLE SNOWFALL WILL OCCUR.
MINOR ADJUSTMENT MADE TO OTHER PRODUCTS INCLUDING SLOWING THE
TIMING OF THE HIGH POPS...BUT ALL IN ALL...GRIDS APPEAR TO BE IN
GOOD SHAPE. WILL LIKELY BE ISSUING A STATEMENT LATER THIS EVENING
TO ACCOUNT FOR THE TIMING AND PTYPE TRENDS...SINCE MUCH OF THIS
WILL AFFECT THE MORNING RUSH HOUR.
TIMING OF STEADY PCPN: LATEST HRRR RUN BRINGS THE INITIAL
PRECIPITATION INTO SOUTHERN NEW HAMPSHIRE AROUND 05Z OR 06Z WITH
THE HEAVIEST/STEADIEST PRECIPITATION ENTERING SOUTHERN NEW
HAMPSHIRE AROUND 09Z WHICH SEAMS REASONABLE AT THIS TIME.
PREV DISC...
A WEAK AND FAST MOVING SFC LOW MOVES NE FROM THE MID ATLANTIC
STATES TNGT THEN TRACKS TO THE NE JUST BEYOND THE GULF OF MAINE
FRIDAY...REACHING E OF THE HAGUE LINE LATE IN THE DAY. THE TRACK
IS ABOUT OVER THE BENCHMARK OF 40N 70W BUT DUE TO ITS RAPID
MOVEMENT AMOUNTS SHOULD REMAIN LIGHT. ALSO THE UPR LVL SUPPORT IS
LIMITED WITH A POSITIVE TILTED TROF AND A WEAK SFC LOW AS A
RESULT. STILL...THE MODELS FCST GENERALLY 2-4 INCHES OF SNOW WITH
THE HIGHEST AMOUNTS OVER SOUTHERN AREAS OF INTERIOR MAINE AND NH.
A FEW HIGHER AMOUNTS OF AROUND 5 INCHES CAN`T BE RULED OUT OVER
SOME AREAS OF HIGHER TERRAIN OVER SOUTHERN INTERIOR PORTIONS. THE
MOUNTAINS WILL SEE THE LEAST AMOUNT OF SNOWFALL WITH THIS SYSTEM
WITH ONLY AN INCH OR TWO EXPECTED.
THE TIMING OF THE PCPN IS FOR IT TO BEGIN OVER SOUTHWEST AREAS
AROUND OR SHORTLY AFTER MIDNIGHT BUT THEN RAPIDLY DEVELOP AND
OVERSPREAD THE REST OF THE REGION BY 10Z.
THE PRCP COULD START AS -RA OR MIXED -RASN OVER MORE SERN AND
COASTAL AREAS TNGT AS BOUNDARY LAYER UP TO 925 MB WILL HAVE TEMPS
AROUND OR JUST ABOVE FREEZING. EVENTUALLY PRCP CHANGES TO SN AS
TEMPS COOL DOWN. ON FRIDAY THE SN MAY MIX BACK TO RA IN THE MRNG OVER
THESE AREAS AS SFC AND BOUNDARY LAYER TEMPS AGAIN BEGIN TO CLIMB
INTO THE MID 30S.
&&
.SHORT TERM /8 AM FRIDAY MORNING THROUGH 6 PM FRIDAY/...
CANADIAN HIGH PRES BUILDS SLOWLY SOUTH SO SOME CLEARING AND DRY CONDITIONS
EXPECTED WITH A RETURN TO MUCH COLDER TEMPS. USED A 50/50 BLEND
OF THE MAV/MET TEMPS.
&&
.LONG TERM /FRIDAY NIGHT THROUGH THURSDAY/...
QUIET WEATHER FOR THE MOST THROUGH THE PERIOD. PERHAPS A FEW SNOW
SHOWERS XMAS AFTERNOON AND EVENING WITH SHORT WAVE TROUGH. THIS
MAY START AS SOME LIGHT OCEAN ENHANCED SNOW ON THE MID COAST
DURING THE AFTERNOON ON XMAS. OTHERWISE...WE/LL HAVE TO WAIT UNTIL
THE 28TH OR SO FOR THE POSSIBILITY OF ANYTHING DECENT IN THE
PRECIPITATION DEPT...AND EVEN THEN THE MODELS HAVE BEEN
INCONSISTENT.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
SHORT TERM...VFR CONDS THIS EVENING WILL BECOME MVFR TO IFR AFTER
MIDNIGHT FROM SOUTH TO NORTH AS SNOW DEVELOPS AND SPREADS NORTH.
OVER SOUTHEAST NEW HAMPSHIRE THE PCPN MAY FALL AS A MIX AT TIMES.
CONDITIONS WILL GRADUALLY IMPROVE TO VFR FRIDAY AFTERNOON ALTHOUGH
SOME SCATTERED SNOW SHOWERS MAY BRIEFLY REDUCE CIGS/VSBYS TO MVFR.
VFR CONDS ACROSS ALL AREAS FRIDAY NIGHT.
LONG TERM...MAINLY VFR THROUGH TUESDAY. A PERIOD OF MVFR POSSIBLE
XMAS DAY AND NIGHT IN SNOW SHOWERS.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS WILL REMAIN BELOW SCA LEVELS
TNGT AND FRIDAY AS A WEAK AND FAST MOVING COASTAL LOW PASSES SOUTH
OF NEW ENGLAND. CANADIAN HIGH PRESSURE TO OUR NORTH SLOWLY BUILDS
SOUTH ACROSS THE WATERS FRIDAY NIGHT.
LONG TERM...SCA CONDS POSSIBLE OVER THE WEEKEND.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR MEZ018.
NH...WINTER WEATHER ADVISORY UNTIL 1 PM EST FRIDAY FOR NHZ005>010.
MARINE...NONE.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS WAKEFIELD VA
432 PM EST FRI DEC 23 2011
.SYNOPSIS...
HIGH PRESSURE BUILDS IN FROM THE WEST TONIGHT THROUGH THE HOLIDAY
WEEKEND. A COLD FRONT WILL MOVE ACROSS THE AREA SUNDAY NIGHT WITH
HIGH PRESSURE BUILDING BACK IN FOR MONDAY.
&&
.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
COLDER AIR CONTINUES TO FILTER INTO THE REGION. TEMPERATURES WILL
DROP QUICKLY AFTER SUNSET EVEN WITH A FEW CLOUDS STILL LINGERING.
SATELLITE IMAGERY SHOWS AN UPPER LOW MOVING ACROSS WISCONSIN AND
APPEARS NOW ON SATELLITE TO BE MOVING MOSTLY EAST WHICH MATCHES
WELL WITH BOTH THE GFS AND NAM WHICH KEEP IT MOVING ACROSS NEW
ENGLAND TONIGHT. SOME STRATOCU HAS BEEN ABLE TO SPILL OVER THE
MOUNTAINS THIS AFTERNOON AND MAY LINGER IN THE NORTH FOR WHILE
THIS EVENING AS THE UPPER LOW PUSHES BY TO THE NORTH. ALSO A
STRONG JET STREAK IS ACROSS THE AREA TONIGHT WHICH MIGHT HELP TO
KEEP A FEW UPPER LEVEL CLOUDS AROUND. ALL AREAS SHOULD BE CLEAR BY
MORNING. FOLLOWED MOS GUIDE FOR THE MINS TONIGHT. THINK WITH SOME
WINDS AND A FEW CLOUDS TEMPERATURES WILL STAY UP A LITTLE.
&&
.SHORT TERM /6 AM SATURDAY MORNING THROUGH MONDAY/...
HIGH PRESSURE CENTERED IN THE MIDWEST WILL RIDGE EAST ACROSS THE
AREA SATURDAY THROUGH SUNDAY. UPPER LEVEL FLOW FEATURES A STRONG
WEST TO EAST JET ACROSS THE AREA AND THIS IS KEEPING MOISTURE TO
THE SOUTH AND MOST OF THE COLD AIR IS BEING HELD FARTHER NORTH.
MODELS SHOW ANOTHER FAST MOVING UPPER SYSTEM MOVING SOUTHEAST
ACROSS THE AREA ON CHRISTMAS DAY AND THIS WILL PUSH A COLD FRONT
THROUGH. DO NOT SEE MUCH IN THE WAY OF MOISTURE WITH THIS SYSTEM
WITH MAINLY DRY WEST FLOW AHEAD OF THE SYSTEM. MIGHT SEE A PARTLY
CLOUDY DAY IN SOME AREAS ON CHRISTMAS DAY. THEN BACK TO SUNNY
WEATHER AGAIN FOR MONDAY. TEMPERATURES WILL BE CLOSE TO NORMAL
THROUGH THE PERIOD WITH HIGHS NEAR 50 AND LOWS IN THE UPPER 20S TO
MID 30S. THIS IS CLOSE TO MOS GUIDE WHICH LOOKS TO HAVE A GOOD
HANDLE ON THE TEMPERATURES. THE COOLEST DAYS WILL BE SATURDAY AND
MONDAY WITH CHRISTMAS A FEW DEGREES WARMER.
&&
.LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
THE STRONGLY POSITIVE NAO PATTERN OF THE PAST MONTH WILL CONTINUE
INTO NEXT WEEK. THIS WILL KEEP ARCTIC AIR LOCKED WELL NORTH IN
CANADA (ABOVE 60N LATITUDE) AND CONTINUE TO ALLOW PACIFIC AIR TO
STREAM ACROSS THE COUNTRY WITH AN OCCASIONAL MODIFIED POLAR AIRMASS
CLIPPING THE EXTREME NORTHERN TIER OF THE US. THIS WILL MAINTAIN
ABOVE NORMAL TEMPERATURES ACROSS THE MID ATLANTIC ALTHOUGH WITHIN +1
STDEV OF THE MEAN. A SOUTHERN STREAM SYSTEM IS EXPECTED TO CROSS THE
TENNESSEE VALLEY MONDAY NIGHT AND MOVE THROUGH THE MID ATLANTIC
TUESDAY. MODEL AGREEMENT HAS INCREASED WITH THIS SYSTEM WITH THE GFS
AND ECMWF DEMONSTRATING DECENT TIMING AGREEMENT WITH THE CMC SLIGHTLY
SLOWER. HIGH PRESSURE RETURNS FROM THE SOUTHWEST BEHIND THIS SYSTEM
WITH PLEASANT CONDITIONS FOLLOWING FOR THE MIDDLE AND END OF THE
WEEK.
&&
.AVIATION /22Z FRIDAY THROUGH WEDNESDAY/...
THE COLD FRONT HAS PUSHED WELL TO THE SOUTH OF THE TAF SITES.
STRATUS ASSOCIATED WITH THE FRONT IS GIVING WAY TO SCATTERED CUMULUS
WHICH WILL THEN CLEAR AS THE SUN SETS. A WEAK SHORT WAVE MOVING OVER
THE MID ATLANTIC STATES DURING THE EARLY MORNING HOURS COULD PRODUCE
A FEW MID LEVEL CLOUDS BUT LEFT THE TAFS CLEAR. GUSTY WINDS FROM
THIS MORNING HAVE DIMINISHED AND SHOULD BECOME LIGHT BY THIS
EVENING. CLEAR SKIES AND LIGHT WINDS ARE EXPECTED SATURDAY AS
SURFACE HIGH PRESSURE SETTLES OVER THE AREA.
OUTLOOK...VFR/DRY WEATHER EXPECTED THROUGH MONDAY. THERE WILL BE A
CHANCE FOR RAIN AND LOWER AVIATION CONDITIONS TUESDAY.
&&
.MARINE...
A SECONDARY SURGE IS AFFECTING THE BAY LATE THIS AFTERNOON. MODEL
GUIDANCE HAS STRUGGLED WITH THIS SURGE...ALTHOUGH THE LATEST RUC AND
HRRR RUNS INDICATE SPEED COULD LINGER AROUND LOW END SCA CRITERIA
FOR THE BAY AND SOUND INTO THIS EVENING. THEREFORE...AN SCA FLAG HAS
BEEN RAISED THROUGH 10 PM. CONDITIONS OVER THE OCEAN SHOULD LARGELY
REMAIN SUB-SCA THROUGH THE EVENING.
HIGH PRESSURE BUILDS INTO THE REGION OVERNIGHT BRINGING BENIGN
CONDITIONS THROUGH CHRISTMAS MORNING. A STRONG LOW PRESSURE SYSTEM
DIGS ACROSS THE NORTHERN GREAT LAKES AND NORTHERN NEW ENGLAND
CHRISTMAS DAY INTO CHRISTMAS NIGHT. THIS PUSHES A COLD FRONT THROUGH
THE NORTHEAST AND NORTHERN MID ATLANTIC FOLLOWED BY A STRONG NW CAA
SURGE LATE CHRISTMAS NIGHT INTO MONDAY MORNING. SOLID SCA CONDITIONS
APPEAR LIKELY DURING THIS TIME.
HIGH PRESSURE BRIEFLY RETURNS MONDAY BEFORE QUICKLY MOVING OFF THE
COAST AS ANOTHER LOW PRESSURE SYSTEM APPROACHES FROM THE SOUTHWEST
MONDAY NIGHT AND TUESDAY.
&&
.AKQ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
NC...NONE.
VA...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 10 PM EST THIS EVENING FOR
ANZ630>634.
&&
$$
SYNOPSIS...JAB
NEAR TERM...JAB
SHORT TERM...JAB
LONG TERM...AJZ
AVIATION...LSA
MARINE...AJZ
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
1035 AM EST FRI DEC 23 2011
.SYNOPSIS...
NORTHEAST EXITING LOW PRESSURE WILL LEAVE LITTLE MORE THAN DRIZZLE
AND FLURRIES EARLY TODAY. WEAK HIGH PRESSURE WILL PROVIDE DRY
SEASONABLE CONDITIONS FOR CHRISTMAS EVE AND MORNING. A CANADIAN
COLD FRONT MAY BRING RAIN AND SNOW SHOWERS CHRISTMAS NIGHT INTO
MONDAY.
&&
.NEAR TERM /THROUGH TONIGHT/...
15Z ENHANCED SHORT TERM FORECAST HAS BEEN ISSUED TO UPDATE WEATHER
GRIDS WITH PATCHY AREAS OF DRIZZLE ALONG WITH A FEW FLURRIES
POSSIBLE INTO THE EARLY AFTERNOON.
THE LATEST MID-LEVEL ANALYSIS INDICATES THE UPPER OHIO
VALLEY IN A SOUTHWESTERLY FLOW WITH A SHORT WAVE SLIDING
SOUTHEASTWARD ACROSS THE UPPER MIDWEST. AT THE SURFACE, A 1010MB
LOW IS LOCATED ACROSS NORTHERN MINNESOTA WITH A BROAD AREA OF HIGH
PRESSURE EXTENDING FROM THE CENTRAL PLAINS INTO THE OHIO VALLEY.
LINGERING MOISTURE RELATED TO THE LOW THAT BROUGHT PRECIP TO THE
AREA LAST NIGHT IS PULLING EAST OF THE AREA. THUS, SOME LINGERING
PATCHY DRIZZLE AND FLURRIES REMAIN ACROSS THE AREA.
REST OF TODAY...LOW-LEVEL MOISTURE IN THE WAKE OF THE LOW WILL BE
SLOW TO SLIDE EASTWARD ACROSS THE AREA TODAY. THUS, A CLOUDY DAY
CAN BE EXPECTED. WITH THE SUPPORT OF RUC FORECAST SOUNDINGS, PATCHY
DRIZZLE AND FLURRIES ARE FORECAST. A FEW LOCALIZED AREAS ACROSS
THE I-80 CORRIDOR AND EASTERN RIDGES WILL DROP BELOW 32 IN COLD
AIR ADVECTION TODAY AND THUS THE BRIEF MENTION OF FREEZING DRIZZLE
IS IN PLACE THERE. PRECIPITATION WILL BE TOO LIGHT, HOWEVER, TO
LEAD TO ANY ICING. ELSEWHERE, FORECAST IS CLOSEST TO LAMP GUIDANCE
WITH TEMPERATURES FAIRLY STEADY IN THE MID TO UPPER 30S ACROSS THE
AREA.
TONIGHT...A SHORT WAVE WILL SLIDE ACROSS THE LOWER GREAT LAKES
AND INTO THE UPPER OHIO VALLEY. WITH THE SUPPORT OF THE 4KM NAM,
SHORT WAVE MAY HAVE JUST ENOUGH ENERGY TO SQUEEZE OUT A FEW
FLURRIES AS IT PASSES THE AREA. THUS, HAVE ADDED THE CHANCE OF
FLURRIES OVERNIGHT FOR AREAS NORTH OF THE I-70 CORRIDOR AND THE
EASTERN RIDGES. LOWS TONIGHT ARE CLOSE TO MAV GUIDANCE, RANGING
FROM THE LOWER 20S ACROSS THE I-80 CORRIDOR AND EASTERN RIDGES TO
THE UPPER 20S IN PORTIONS OF EASTERN OHIO AND NORTH-CENTRAL WV.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY/...
WEAK MIDWEST HIGH PRESSURE WILL PROVIDE SLOW CLEARING TONIGHT
ACROSS THE UPPER OHIO VALLEY, BUT DO EXPECT A DECENT AMOUNT OF SUNSHINE
FOR SATURDAY CHRISTMAS EVE.
RECENT SREF MODEL OUTPUT SHOWS A CLIPPER-TYPE LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES CHRISTMAS AFTERNOON
AND NIGHT, WHICH CAN PRODUCE COLD FRONTAL SHOWERS ACROSS THE UPPER
OHIO VALLEY. REGARDING PRECIPITATION TYPE, THE SURFACE LAYER
SHOULD BE WARM ENOUGH FOR IT TO BE RAIN SOUTH, BUT IT COULD BE
EITHER RAIN OR SNOW NORTH, AS GFS AND NAM MOS SUGGEST TEMPERATURES
TO BE NEAR SEASONABLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS POST SYSTEM SNOW SHOWERS SHOULD BE
EXITING PAST THE MOUNTAINS MONDAY MORNING. ENSUING MIDWEST HIGH
PRESSURE SHOULD PROVIDE A DRY PERIOD MONDAY AFTERNOON AND NIGHT.
UNCERTAINTY INCREASES STARTING TUESDAY, AS THE UPPER JETSTREAM
FLOW EVOLVES INTO A WAVY ZONAL PATTERN ACROSS U.S.
ECMWF, CMC, AND A COUPLE MEMBERS OF THE GEFS MODEL OUTPUT SHOW AN
OCCLUDED FRONTAL SYSTEM MAY PASS EASTWARD THROUGH THE UPPER OHIO
VALLEY TUESDAY. ITS LIKEWISE POSSIBLE A SIMILAR TYPE SYSTEM MAY
PASS THROUGH THURSDAY OR FRIDAY.
WITH THE RESULTING LACK OF COLD AIR INTRUSION, EXPECT TEMPERATURES
THIS PERIOD TO AVERAGE 5 TO 8 DEGREES WARMER THAN NORMAL.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
CIGS BEGINNING TO LIFT TO MVFR THIS MORNING BUT STILL PERIOD OF IFR
CIGS MOVING SOUTHEAST IN NORTHWEST FLOW. HAVE ADDED A TEMPO GROUP TO
ACCOUNT FOR THIS THROUGH 18-19Z. SPOTTY DRIZZLE OR FLURRIES WILL
LIKEWISE END BY THEN.
MVFR STRATUS SHOULD BECOME SCATTERED BY EVENING, EXCEPT ACROSS THE
I-80 CORRIDOR AND PERHAPS NEAR THE MOUNTAINS WHERE THE STRATUS MAY
NOT DISSIPATE UNTIL LATE TONIGHT.
OUTLOOK...SATURDAY THROUGH TUESDAY...
EXPECT MAINLY VFR SATURDAY INTO MIDDAY SUNDAY. THEN COLD FRONTAL
SHOWERS MAY CAUSE RESTRICTIONS CHRISTMAS SUNDAY AFTERNOON INTO
MIDDAY MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
620 AM EST FRI DEC 23 2011
.SYNOPSIS...
NORTHEAST EXITING LOW PRESSURE WILL LEAVE LITTLE MORE THAN DRIZZLE
AND FLURRIES THIS MORNING. WEAK HIGH PRESSURE WILL PROVIDE DRY
SEASONABLE CONDITIONS FOR CHRISTMAS EVE AND MORNING. A CANADIAN
COLD FRONT MAY BRING RAIN AND SNOW SHOWERS CHRISTMAS NIGHT INTO
MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM
MODEL OUTPUT SHOW LITTLE MORE THAN SCATTERED DRIZZLE OR FLURRIES
LEFT ACROSS THE UPPER OHIO VALLEY IN THE WAKE OF THE NORTHEAST
EXITING LOW PRESSURE SYSTEM. NAM MODEL PROFILES SHOW DRYING ALOFT
WILL CONTINUE, SO DO NOT EXPECT ANY LAKE-INDUCED INSTABILITY
SHOWER DEVELOPMENT AND HENCE ALL PRECIPITATION TO DRY UP BY
MIDDAY.
LOW LEVEL DRYING WILL BE SLOWER, SO POST SYSTEM CLOUDS WILL LINGER
INTO THE AFTERNOON AND RESTRICT DAYTIME TEMPERATURE RISES TO NO
MORE THAN A COUPLE DEGREES OVER CURRENT READINGS. THIS IDEA
CONTINUES SUPPORTED BY RECENT HRRR VALUES AS WELL AS GFS AND NAM
MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WEAK MIDWEST HIGH PRESSURE WILL PROVIDE SLOW CLEARING TONIGHT
ACROSS THE UPPER OHIO VALLEY, BUT DO EXPECT A DECENT AMOUNT OF SUNSHINE
FOR SATURDAY CHRISTMAS EVE.
RECENT SREF MODEL OUTPUT SHOWS A CLIPPER-TYPE LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES CHRISTMAS AFTERNOON
AND NIGHT, WHICH CAN PRODUCE COLD FRONTAL SHOWERS ACROSS THE UPPER
OHIO VALLEY. REGARDING PRECIPITATION TYPE, THE SURFACE LAYER
SHOULD BE WARM ENOUGH FOR IT TO BE RAIN SOUTH, BUT IT COULD BE
EITHER RAIN OR SNOW NORTH, AS GFS AND NAM MOS SUGGEST TEMPERATURES
TO BE NEAR SEASONABLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS POST SYSTEM SNOW SHOWERS SHOULD BE
EXITING PAST THE MOUNTAINS MONDAY MORNING. ENSUING MIDWEST HIGH
PRESSURE SHOULD PROVIDE A DRY PERIOD MONDAY AFTERNOON AND NIGHT.
UNCERTAINTY INCREASES STARTING TUESDAY, AS THE UPPER JETSTREAM
FLOW EVOLVES INTO A WAVY ZONAL PATTERN ACROSS U.S.
ECMWF, CMC, AND A COUPLE MEMBERS OF THE GEFS MODEL OUTPUT SHOW AN
OCCLUDED FRONTAL SYSTEM MAY PASS EASTWARD THROUGH THE UPPER OHIO
VALLEY TUESDAY. ITS LIKEWISE POSSIBLE A SIMILAR TYPE SYSTEM MAY
PASS THROUGH THURSDAY OR FRIDAY.
WITH THE RESULTING LACK OF COLD AIR INTRUSION, EXPECT TEMPERATURES
THIS PERIOD TO AVERAGE 5 TO 8 DEGREES WARMER THAN NORMAL.
&&
.AVIATION /11Z FRIDAY THROUGH TUESDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR,
NAM, AND GFS LAMP MODEL OUTPUT, EXPECT IT STILL MAY BE MIDDAY
BEFORE PREVALENT IFR STRATUS CEILINGS LIFT TO MVFR LEVELS. SPOTTY
DRIZZLE OR FLURRIES WILL LIKEWISE END BY THEN.
STRATUS SHOULD BECOME SCATTERED BY EVENING, EXCEPT ACROSS THE I-80
CORRIDOR AND PERHAPS NEAR THE MOUNTAINS WHERE THE STRATUS MAY NOT
DISSIPATE UNTIL LATE TONIGHT.
OUTLOOK...SATURDAY THROUGH TUESDAY...
EXPECT MAINLY VFR SATURDAY INTO MIDDAY SUNDAY. THEN COLD FRONTAL
SHOWERS MAY CAUSE RESTRICTIONS CHRISTMAS SUNDAY AFTERNOON INTO
MIDDAY MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
427 AM EST FRI DEC 23 2011
.SYNOPSIS...
NORTHEAST EXITING LOW PRESSURE WILL LEAVE LITTLE MORE THAN DRIZZLE
AND FLURRIES THIS MORNING. WEAK HIGH PRESSURE WILL PROVIDE DRY
SEASONABLE CONDITIONS FOR CHRISTMAS EVE AND MORNING. A CANADIAN
COLD FRONT MAY BRING RAIN AND SNOW SHOWERS CHRISTMAS NIGHT INTO
MONDAY.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM
MODEL OUTPUT SHOW LITTLE MORE THAN DRIZZLE OR FLURRIES LEFT ACROSS
THE UPPER OHIO VALLEY IN THE WAKE OF THE NORTHEAST EXITING LOW
PRESSURE SYSTEM. NAM MODEL PROFILES SHOW DRYING ALOFT WILL
CONTINUE, SO DO NOT EXPECT ANY LAKE-INDUCED INSTABILITY SHOWER
DEVELOPMENT.
LOW LEVEL DRYING WILL BE SLOWER, SO POST SYSTEM CLOUDS WILL LINGER
INTO THE AFTERNOON AND RESTRICT DAYTIME TEMPERATURE RISES TO NO
MORE THAN A COUPLE DEGREES OVER CURRENT READINGS, AN IDEA
SUPPORTED BY RECENT GFS AND NAM MOS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH SUNDAY/...
WEAK MIDWEST HIGH PRESSURE WILL PROVIDE SLOW CLEARING TONIGHT
ACROSS THE UPPER OHIO VALLEY, BUT DO EXPECT A DECENT AMOUNT OF SUNSHINE
FOR SATURDAY CHRISTMAS EVE.
RECENT SREF MODEL OUTPUT SHOWS A CLIPPER-TYPE LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES CHRISTMAS AFTERNOON
AND NIGHT, WHICH CAN PRODUCE COLD FRONTAL SHOWERS ACROSS THE UPPER
OHIO VALLEY. REGARDING PRECIPITATION TYPE, THE SURFACE LAYER
SHOULD BE WARM ENOUGH FOR IT TO BE RAIN SOUTH, BUT IT COULD BE
EITHER RAIN OR SNOW NORTH, AS GFS AND NAM MOS SUGGEST TEMPERATURES
TO BE NEAR SEASONABLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS POST SYSTEM SNOW SHOWERS SHOULD BE
EXITING PAST THE MOUNTAINS MONDAY MORNING. ENSUING MIDWEST HIGH
PRESSURE SHOULD PROVIDE A DRY PERIOD MONDAY AFTERNOON AND NIGHT.
UNCERTAINTY INCREASES STARTING TUESDAY, AS THE UPPER JETSTREAM
FLOW EVOLVES INTO A WAVY ZONAL PATTERN ACROSS U.S.
ECMWF, CMC, AND A COUPLE MEMBERS OF THE GEFS MODEL OUTPUT SHOW AN
OCCLUDED FRONTAL SYSTEM MAY PASS EASTWARD THROUGH THE UPPER OHIO
VALLEY TUESDAY. ITS LIKEWISE POSSIBLE A SIMILAR TYPE SYSTEM MAY
PASS THROUGH THURSDAY OR FRIDAY.
WITH THE RESULTING LACK OF COLD AIR INTRUSION, EXPECT TEMPERATURES
THIS PERIOD TO AVERAGE 5 TO 8 DEGREES WARMER THAN NORMAL.
&&
.AVIATION /09Z FRIDAY THROUGH TUESDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR,
NAM, AND GFS LAMP MODEL OUTPUT, EXPECT IFR STRATUS TO REMAIN
ACROSS THE UPPER OHIO VALLEY INTO MORNING WITH PRECIPITATION REDUCED
TO LITTLE MORE THAN DRIZZLE OF FLURRIES IN SPOTS.
BY MIDDAY, EXPECT MOST STRATUS CEILINGS WILL HAVE LIFTED TO MVFR
LEVELS, AND STRATUS COULD BECOME SCATTERED BY EVENING.
OUTLOOK...SATURDAY THROUGH TUESDAY...
EXPECT MAINLY VFR SATURDAY INTO MIDDAY SUNDAY. THEN COLD FRONTAL
SHOWERS MAY CAUSE RESTRICTIONS CHRISTMAS SUNDAY AFTERNOON INTO
MIDDAY MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS PITTSBURGH PA
158 AM EST FRI DEC 23 2011
.SYNOPSIS...
NORTHEAST EXITING LOW PRESSURE WILL LEAVE LITTLE MORE THAN DRIZZLE
AND FLURRIES THIS MORNING. WEAK HIGH PRESSURE WILL PROVIDE DRY
SEASONABLE CONDITIONS FOR CHRISTMAS EVE AND MORNING. A CANADIAN
COLD FRONT MAY BRING RAIN AND SNOW SHOWERS CHRISTMAS NIGHT INTO
MONDAY.
&&
.NEAR TERM /THROUGH TODAY/...
BLEND OF RECENT SURFACE AND RADAR DATA ALONG WITH HRRR AND NAM
MODEL OUTPUT SHOW THE LIGHT RAIN ASSOCIATED WITH NORTHEAST
EXITING LOW PRESSURE TO DECREASE TO LITTLE MORE THAN DRIZZLE OR
FLURRIES BY DAYBREAK ACROSS THE UPPER OHIO VALLEY.
REGARDING ANY CHANGEOVER TO SNOW SHOWERS, NAM MODEL PROFILES SHOW
POST SYSTEM DRYING ALOFT THAT MAY PRECLUDE CLOUD TEMPERATURES TO
GET COLD ENOUGH FOR A COMPLETE CHANGEOVER TO SNOW SHOWERS THIS
MORNING. LIKEWISE SURFACE TEMPERATURES MAY NOT GET TO FREEZING TO
ALLOW ACCUMULATION.
POST SYSTEM CLOUDS WILL RESTRICT TEMPERATURE RISES TODAY, SO HIGHS
TODAY NOT BE ANY WARMER THAN CURRENT READINGS.
&&
.SHORT TERM /TONIGHT THROUGH SUNDAY/...
WEAK MIDWEST HIGH PRESSURE WILL PROVIDE SLOW CLEARING TONIGHT
ACROSS THE UPPER OHIO VALLEY, BUT DO EXPECT A DECENT AMOUNT OF SUNSHINE
FOR SATURDAY CHRISTMAS EVE.
RECENT SREF MODEL OUTPUT SHOWS A CLIPPER-TYPE LOW PRESSURE SYSTEM
MOVING SOUTHEASTWARD THROUGH THE GREAT LAKES CHRISTMAS AFTERNOON
AND NIGHT, WHICH CAN PRODUCE COLD FRONTAL SHOWERS ACROSS THE UPPER
OHIO VALLEY. REGARDING PRECIPITATION TYPE, THE SURFACE LAYER
SHOULD BE WARM ENOUGH FOR IT TO BE RAIN SOUTH, BUT IT COULD BE
EITHER RAIN OR SNOW NORTH, AS GFS AND NAM MOS SUGGEST TEMPERATURES
TO BE NEAR SEASONABLE.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
RECENT SREF MODEL OUTPUT SHOWS POST SYSTEM SNOW SHOWERS SHOULD BE
EXITING PAST THE MOUNTAINS MONDAY MORNING. ENSUING MIDWEST HIGH
PRESSURE SHOULD PROVIDE A DRY PERIOD MONDAY AFTERNOON AND NIGHT.
UNCERTAINTY INCREASES STARTING TUESDAY, AS THE UPPER JETSTREAM
FLOW EVOLVES INTO A WAVY ZONAL PATTERN ACROSS U.S.
ECMWF, CMC, AND A COUPLE MEMBERS OF THE GEFS MODEL OUTPUT SHOW AN
OCCLUDED FRONTAL SYSTEM MAY PASS EASTWARD THROUGH THE UPPER OHIO
VALLEY TUESDAY. ITS LIKEWISE POSSIBLE A SIMILAR TYPE SYSTEM MAY
PASS THROUGH THURSDAY OR FRIDAY.
WITH THE RESULTING LACK OF COLD AIR INTRUSION, EXPECT TEMPERATURES
THIS PERIOD TO AVERAGE 5 TO 8 DEGREES WARMER THAN NORMAL.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
PER BLEND OF RECENT SURFACE AND RADAR DATA, COUPLED WITH HRRR,
NAM, AND GFS LAMP MODEL OUTPUT, EXPECT IFR STRATUS TO REMAIN
ACROSS THE UPPER OHIO VALLEY INTO MORNING. DO EXPECT PRECIPITATION
TO BE LITTLE MORE THAN DRIZZLE OF FLURRIES IN SPOTS BY THEN.
BY MIDDAY, EXPECT MOST STRATUS CEILINGS WILL HAVE LIFTED TO MVFR
LEVELS, AND STRATUS COULD BECOME SCATTERED BY EVENING.
OUTLOOK...SATURDAY THROUGH TUESDAY...
EXPECT MAINLY VFR SATURDAY INTO MIDDAY SUNDAY. THEN COLD FRONTAL
SHOWERS MAY CAUSE RESTRICTIONS CHRISTMAS SUNDAY AFTERNOON INTO
MIDDAY MONDAY.
&&
.PBZ WATCHES/WARNINGS/ADVISORIES...
MD...NONE.
OH...NONE.
PA...NONE.
WV...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1246 PM EST FRI DEC 23 2011
UPDATED AVIATION DISCUSSION FOR 18Z TAFS
.UPDATE...SYSTEM SNOW IS PRESSING INTO FAR WESTERN UPR MI AND WILL
CONTINUE TO SPREAD ACROSS ALL OF CWA THROUGH THE AFTN. REGIONAL
RADAR AND SFC OBS INDICATE HEAVIEST SNOW IN CORRIDOR FM NORTHEAST MN
NEAR KDLH INTO NW WI...STILL WEST AS KASX. THIS AREA IS JUST TO
RIGHT OF SHORTWAVE TRACKING ACROSS CNTRL MN. EXPECT MODERATE SNOW AT
TIMES INTO THE AFTN OVR SW CWA. COULD SEE 1-2 INCHES IN THAT AREA.
LESS THAN 1 INCH WILL PROBABLY COVER IT ELSEWHERE. GOING FCST IN
PRETTY GOOD SHAPE WITH REGARD TO SYSTEM SNOW.
SOUTH/SOUTHWEST WINDS FLOWING UP LK MICHIGAN WITH H85 TEMPS AROUND
-10C LEADS TO DELTA T/S UP TO 16C. FCST SOUNDINGS IN THIS AREA
DEPICT LARGE SCALE LIFT OCCURRING WITHIN GOOD PORTION OF DENDRITIC
GROWTH ZONE. THIS INCREASING OVER-WATER INSTABILITY COMBINED WITH
FORCING FM SYSTEM MOVING THROUGH LATE AFTN/EVENING SHOULD LEAD TO
GOOD SETUP FOR LAKE ENHANCED SNOW. HIGHER RESOLUTION MODELS DIFFERING
ON WHERE TO FOCUS SHARPEST LOW-LEVEL CONVERGENCE AND HEAVIER SNOW OVR
EASTERN CWA. GIVEN 925-850MB WINDS IN THE 210-230 RANGE AND SFC
CONVERGENCE FCST TO INCREASE INTO SOUTHERN PORTION OF LUCE COUNTY...OPTED
TO ISSUE A WINTER WEATHER ADVY FOR SNOW LATE TODAY AND THIS EVENING
FOR LUCE COUNTY. SFC LOW IS A BIT STRONGER THAT MODELS HAVE SHOWN
THUS FAR SO IF ANYTHING BLYR WINDS MAY BACK MORE THAN IS SHOWN.
THOUGHT POTENTIAL FOR ADVY LEVEL SNOWS WAS TOO HIGH TO NOT HAVE ANY
HEADLINE OUT SO HAVE POSTED ONE FM 21Z TODAY THROUGH 05Z TONIGHT.
TOTAL SNOW ACCUMS 3-5 INCHES EXPECTED...PROBABLY HEAVIEST JUST SOUTH
AND EAST OF KERY...AND INTO MACKINAC COUNTY WHERE GAYLORD MI NWS
OFFICE ALREADY HAS ADVY OUT THROUGH TONIGHT.
COULD SEE TRAVEL BECOMING QUITE DIFFICULT SOMEWHERE IN THIS AREA
THIS EVENING DUE TO SNOW COVERED ROADS AND POOR VISIBILITY. HAZARD
IS FURTHER HEIGHTENED SINCE IT IS OCCURRING ON FRIDAY EVENING
PRECEEDING THE CHRISTMAS HOLIDAY WEEKEND.
&&
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL TROUGHING FROM
NE CANADA INTO THE CNTRL CONUS RESULTING IN NW FLOW FROM CNTRL
CANADA INTO THE GREAT LAKES. A PROMINENT UPSTREAM SHORTWAVE TROUGH
WAS LOCATED NEAR LAKE WINNIPEG. AT THE SFC...SRLY WINDS WERE
INCREASING OVER MN AND WRN LAKE SUPERIOR AHEAD OF LOW PRES OVER THE
SE CORNER OF MANITOBA. THE AREA OF WAA LIGHT SNOW HAD MOVED INTO NRN
MN WITH VSBYS DOWN TO 1-3SM. LINGERING SCT LIGHT LAKE EFFECT SNOW
SHOWERS OVER ERN LAKE SUPERIOR WERE QUICKLY DIMINISHING AND STARING
TO MOVE OFFSHORE AS THE RIDGE AXIS MOVES THROUGH AND WINDS BACK TO
THE SW.
&&
.DISCUSSION...
TODAY AND TONIGHT...EXPECT THE AREA OF SNOW TO MAKE STEADY PROGRESS
TO THE SE AS THE MANTITOBA CLIPPER SHORTWAVE AND LOW APPROACH THE
AREA. THE BAND OF MODERATE TO STRONG NET 280K ISENTROPIC ASCENT AND
700-300 MB QVECTOR CONV WILL SUPPORT GOING HIGHER END POPS ACROSS THE
CWA...MAINLY BTWN 18Z-24Z. HOWEVER...MOISTURE WILL BE LIMITED WITH
ONLY 1.0 1O 1.5 G/KG AVAILABLE IN THE 700-750 MB LAYER AND PWAT
VALUES OF AROUND 0.25 INCH. SO...ACCUMULATIONS SHOULD REMAIN
GENERALLY LIGHT...AT OR BELOW AN INCH. DOWNSLOPE SRLY FLOW MAY ALSO
REDUCE AMOUNTS NEAR LAKE SUPERIOR IN NORTH CENTRAL UPPER MI. 850 MB
TEMPS AROUND -10C SUPPORT POTENTIAL FOR SOME LAKE ENHANCED SNOW NEAR
LAKE MICHIGAN. WITH ONLY A BRIEF PERIOD OF DEEPER MOISTURE/LIFT
MOVING THROUGH ANY ADDITIONAL AMOUNTS WILL ALSO BE SMALL. THE BEST
CHANCE FOR MORE SIGNIFICANT SNOW AMOUNTS WILL BE EAST OF
MANISTIQUE...GIVEN PREDOMINANT 220-230 CBL FLOW LATE THIS AFTERNOON
AND EVENING.
WITH ONLY MODERATE INSTABILITY...THE SNOW WILL DIMINISH QUICKLY OVER
FROM WEST TO EAST IN THE EVENING AS THE SHORTWAVE MOVES THROUGH AND
SUBSIDENCE TAKES OVER. CLOUDS MAY ALSO DIMINISH LATE AS 925-850 MB
WEST FLOW DRY ADVECTION MOVES IN.
SATURDAY...DRY WEATHER IS EXPECTED AS THE FORCING AND ISENTROPIC
NEXT WEAKER CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE
CWA...PER GFS/ECMWF/GEM. 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.
THERE WAS GREATER UNCERTAINTY WITH POTENTIAL FOR LIGHT SYNOPTIC
LIGHT SNOW. THE GFS WAS FARTHER SOUTH WITH THIS FEATURE COMAPRED TO
THE ECMWF/GEM. WITH LITTLE MOISTURE AVBL...CHANCE POPS WERE CONFINED
TO LOCATIONS FAVORED BY WNW FLOW WHERE SOME LAKE ENHANCEMENT MAY
OCCUR WITH 850 MB TEMPS AROUND -10C.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILD INTO THE AREA WITH
STRGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. THE MILD PATTERN CONTINUES THROUGH MUCH OF THE WEEK
WITH ADDITIONAL CLIPPER SYSTEMS MOVING THROUGH. UNCERTAINTY IS
LARGER WITH STRENGTH OF CAA IN THE WAKE OF ANY SYSTEM. THE 00Z
GFS/GEM AND MAJORITY OF GFS ENS SUGGESTED THAT COLD AIR BY TUE INTO
TUE NIGHT WOULD REMAIN ONLY NEAR -10C WHILE THE 00Z ECMWF FCST H8
TEMPS DOWN TO -15C WHICH WOULD BRING GREATER CHANCE FOR SIGNFICANT
LES.
&&
.AVIATION /FOR THE 18Z TAF ISSUANCE/...
A CLIPPER SYSTEM DROPPING SE ACROSS UPPER MICHIGAN WILL SPREAD SNOW
ACROSS THE AREA FROM WEST TO EAST THROUGH EARLY EVENING. HAVE
CONTINUED ALT LANDING MINS FOR ALL SITES DURING THE PEAK SNOW THIS
AFTN. AS THE SYSTEM EXITS...EXPECT BORDERLINE IFR CIGS TO CONTINUE
BEFORE DIMINISHING OVERNIGHT. MODELS CONTINUE TO FCST LOW STRATUS
LATE TONIGHT...BUT BASED ON UPSTREAM CONDITIONS WITH CLEARING SKIES
IN DAKOTAS AND SOUTHERN SASKATCHEWAN AND LACK OF ONSHORE FLOW AT
ANY OF THE TAF SITES...THIS SEEMS OVERDONE. CONTINUED TO SHOW SLIGHT
POSSIBILITY WITH FCST OF SCT LOW CLOUDS. &&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH MODELS COMING TO A CONSENSUS ON LOW TRACK/INTENSITY ACROSS LAKE
SUPERIOR TODAY...HAVE ADJUSTED WINDS DOWN A TOUCH AND ONLY THINK
THERE WILL BE A PERIOD /LATE MORNING THROUGH THE AFTN/ OF SW GUSTS
UP TO 30KTS AHEAD OF THE LOW. WINDS SHOULD DIMINISH BELOW 20KTS
TONIGHT AS THE LOW DISSIPATES WHEN MOVING INTO THE LOWER GREAT
LAKES. SW WINDS WILL ONCE AGAIN BE ON THE INCREASE SAT AHEAD OF THE
NEXT TROUGH TO AFFECT LK SUPERIOR. THIS STRONGER TROUGH WILL PRODUCE
WINDS UP TO 30KTS SAT INTO SUN...AS WINDS GRADUALLY SHIFT TO THE NW
BY SUN WITH THE TROUGH PUSHING EAST. THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS TO 35KTS DURING THAT PERIOD. AFTER A BRIEF REPRIVE
ON SUN NIGHT...THE NEXT TROUGH WILL AFFECT LK SUPERIOR MON INTO MON
NIGHT. WITH THIS TROUGH EVEN STRONGER...APPEARS TO BE A GOOD CHANCE
OF SEEING SW GALES TO 35KTS OVER MUCH OF LAKE SUPERIOR MON
AFTN/NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO MIDNIGHT EST
TONIGHT FOR MIZ007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...JLA
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
1133 AM EST FRI DEC 23 2011
.UPDATE...SYSTEM SNOW IS PRESSING INTO FAR WESTERN UPR MI AND WILL
CONTINUE TO SPREAD ACROSS ALL OF CWA THROUGH THE AFTN. REGIONAL
RADAR AND SFC OBS INDICATE HEAVIEST SNOW IN CORRIDOR FM NORTHEAST MN
NEAR KDLH INTO NW WI...STILL WEST AS KASX. THIS AREA IS JUST TO
RIGHT OF SHORTWAVE TRACKING ACROSS CNTRL MN. EXPECT MODERATE SNOW AT
TIMES INTO THE AFTN OVR SW CWA. COULD SEE 1-2 INCHES IN THAT AREA.
LESS THAN 1 INCH WILL PROBABLY COVER IT ELSEWHERE. GOING FCST IN
PRETTY GOOD SHAPE WITH REGARD TO SYSTEM SNOW.
SOUTH/SOUTHWEST WINDS FLOWING UP LK MICHIGAN WITH H85 TEMPS AROUND
-10C LEADS TO DELTA T/S UP TO 16C. FCST SOUNDINGS IN THIS AREA
DEPICT LARGE SCALE LIFT OCCURRING WITHIN GOOD PORTION OF DENDRITIC
GROWTH ZONE. THIS INCREASING OVER-WATER INSTABILITY COMBINED WITH
FORCING FM SYSTEM MOVING THROUGH LATE AFTN/EVENING SHOULD LEAD TO
GOOD SETUP FOR LAKE ENHANCED SNOW. HIGHER RESOLUTION MODELS DIFFERING
ON WHERE TO FOCUS SHARPEST LOW-LEVEL CONVERGENCE AND HEAVIER SNOW OVR
EASTERN CWA. GIVEN 925-850MB WINDS IN THE 210-230 RANGE AND SFC
CONVERGENCE FCST TO INCREASE INTO SOUTHERN PORTION OF LUCE COUNTY...OPTED
TO ISSUE A WINTER WEATHER ADVY FOR SNOW LATE TODAY AND THIS EVENING
FOR LUCE COUNTY. SFC LOW IS A BIT STRONGER THAT MODELS HAVE SHOWN
THUS FAR SO IF ANYTHING BLYR WINDS MAY BACK MORE THAN IS SHOWN.
THOUGHT POTENTIAL FOR ADVY LEVEL SNOWS WAS TOO HIGH TO NOT HAVE ANY
HEADLINE OUT SO HAVE POSTED ONE FM 21Z TODAY THROUGH 05Z TONIGHT.
TOTAL SNOW ACCUMS 3-5 INCHES EXPECTED...PROBABLY HEAVIEST JUST SOUTH
AND EAST OF KERY...AND INTO MACKINAC COUNTY WHERE GAYLORD MI NWS
OFFICE ALREADY HAS ADVY OUT THROUGH TONIGHT.
COULD SEE TRAVEL BECOMING QUITE DIFFICULT SOMEWHERE IN THIS AREA
THIS EVENING DUE TO SNOW COVERED ROADS AND POOR VISIBILITY. HAZARD
IS FURTHER HEIGHTENED SINCE IT IS OCCURRING ON FRIDAY EVENING
PRECEEDING THE CHRISTMAS HOLIDAY WEEKEND.
&&
PREV DISCUSSION...ISSUED AT 631 AM EST FRI DEC 23 2011...
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL TROUGHING FROM
NE CANADA INTO THE CNTRL CONUS RESULTING IN NW FLOW FROM CNTRL
CANADA INTO THE GREAT LAKES. A PROMINENT UPSTREAM SHORTWAVE TROUGH
WAS LOCATED NEAR LAKE WINNIPEG. AT THE SFC...SRLY WINDS WERE
INCREASING OVER MN AND WRN LAKE SUPERIOR AHEAD OF LOW PRES OVER THE
SE CORNER OF MANITOBA. THE AREA OF WAA LIGHT SNOW HAD MOVED INTO NRN
MN WITH VSBYS DOWN TO 1-3SM. LINGERING SCT LIGHT LAKE EFFECT SNOW
SHOWERS OVER ERN LAKE SUPERIOR WERE QUICKLY DIMINISHING AND STARING
TO MOVE OFFSHORE AS THE RIDGE AXIS MOVES THROUGH AND WINDS BACK TO
THE SW.
&&
.DISCUSSION...
TODAY AND TONIGHT...EXPECT THE AREA OF SNOW TO MAKE STEADY PROGRESS
TO THE SE AS THE MANTITOBA CLIPPER SHORTWAVE AND LOW APPROACH THE
AREA. THE BAND OF MODERATE TO STRONG NET 280K ISENTROPIC ASCENT AND
700-300 MB QVECTOR CONV WILL SUPPORT GOING HIGHER END POPS ACROSS THE
CWA...MAINLY BTWN 18Z-24Z. HOWEVER...MOISTURE WILL BE LIMITED WITH
ONLY 1.0 1O 1.5 G/KG AVAILABLE IN THE 700-750 MB LAYER AND PWAT
VALUES OF AROUND 0.25 INCH. SO...ACCUMULATIONS SHOULD REMAIN
GENERALLY LIGHT...AT OR BELOW AN INCH. DOWNSLOPE SRLY FLOW MAY ALSO
REDUCE AMOUNTS NEAR LAKE SUPERIOR IN NORTH CENTRAL UPPER MI. 850 MB
TEMPS AROUND -10C SUPPORT POTENTIAL FOR SOME LAKE ENHANCED SNOW NEAR
LAKE MICHIGAN. WITH ONLY A BRIEF PERIOD OF DEEPER MOISTURE/LIFT
MOVING THROUGH ANY ADDITIONAL AMOUNTS WILL ALSO BE SMALL. THE BEST
CHANCE FOR MORE SIGNIFICANT SNOW AMOUNTS WILL BE EAST OF
MANISTIQUE...GIVEN PREDOMINANT 220-230 CBL FLOW LATE THIS AFTERNOON
AND EVENING.
WITH ONLY MODERATE INSTABILITY...THE SNOW WILL DIMINISH QUICKLY OVER
FROM WEST TO EAST IN THE EVENING AS THE SHORTWAVE MOVES THROUGH AND
SUBSIDENCE TAKES OVER. CLOUDS MAY ALSO DIMINISH LATE AS 925-850 MB
WEST FLOW DRY ADVECTION MOVES IN.
SATURDAY...DRY WEATHER IS EXPECTED AS THE FORCING AND ISENTROPIC
NEXT WEAKER CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE
CWA...PER GFS/ECMWF/GEM. 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.
THERE WAS GREATER UNCERTAINTY WITH POTENTIAL FOR LIGHT SYNOPTIC
LIGHT SNOW. THE GFS WAS FARTHER SOUTH WITH THIS FEATURE COMAPRED TO
THE ECMWF/GEM. WITH LITTLE MOISTURE AVBL...CHANCE POPS WERE CONFINED
TO LOCATIONS FAVORED BY WNW FLOW WHERE SOME LAKE ENHANCEMENT MAY
OCCUR WITH 850 MB TEMPS AROUND -10C.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILD INTO THE AREA WITH
STRGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. THE MILD PATTERN CONTINUES THROUGH MUCH OF THE WEEK
WITH ADDITIONAL CLIPPER SYSTEMS MOVING THROUGH. UNCERTAINTY IS
LARGER WITH STRENGTH OF CAA IN THE WAKE OF ANY SYSTEM. THE 00Z
GFS/GEM AND MAJORITY OF GFS ENS SUGGESTED THAT COLD AIR BY TUE INTO
TUE NIGHT WOULD REMAIN ONLY NEAR -10C WHILE THE 00Z ECMWF FCST H8
TEMPS DOWN TO -15C WHICH WOULD BRING GREATER CHANCE FOR SIGNFICANT
LES.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
A CLIPPER SYSTEM DROPPING SE ACROSS UPPER MICHIGAN WILL SPREAD SNOW
ACROSS THE AREA FROM WEST TO EAST LATE THIS MORNING THROUGH EARLY
EVENING. HAVE CONTINUED ALT LANDING MINS FOR ALL SITES DURING THE
PEAK SNOW IN THE AFTN HRS. AS THE SYSTEM EXITS...EXPECT BORDERLINE
IFR CIGS TO CONTINUE BEFORE DIMINISHING OVERNIGHT. MODELS HINTING AT
LOW CLOUDS THROUGH A GOOD PORTION OF THE NIGHT AND WOULD HAVE LIKED
TO HAVE SEEN A LITTLE DEEPER MOISTURE TO GO WITH LOW CIGS AND SOME
VSBY REDUCTION AFTER 06Z.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH MODELS COMING TO A CONSENSUS ON LOW TRACK/INTENSITY ACROSS LAKE
SUPERIOR TODAY...HAVE ADJUSTED WINDS DOWN A TOUCH AND ONLY THINK
THERE WILL BE A PERIOD /LATE MORNING THROUGH THE AFTN/ OF SW GUSTS
UP TO 30KTS AHEAD OF THE LOW. WINDS SHOULD DIMINISH BELOW 20KTS
TONIGHT AS THE LOW DISSIPATES WHEN MOVING INTO THE LOWER GREAT
LAKES. SW WINDS WILL ONCE AGAIN BE ON THE INCREASE SAT AHEAD OF THE
NEXT TROUGH TO AFFECT LK SUPERIOR. THIS STRONGER TROUGH WILL PRODUCE
WINDS UP TO 30KTS SAT INTO SUN...AS WINDS GRADUALLY SHIFT TO THE NW
BY SUN WITH THE TROUGH PUSHING EAST. THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS TO 35KTS DURING THAT PERIOD. AFTER A BRIEF REPRIVE
ON SUN NIGHT...THE NEXT TROUGH WILL AFFECT LK SUPERIOR MON INTO MON
NIGHT. WITH THIS TROUGH EVEN STRONGER...APPEARS TO BE A GOOD CHANCE
OF SEEING SW GALES TO 35KTS OVER MUCH OF LAKE SUPERIOR MON
AFTN/NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
WINTER WEATHER ADVISORY FROM 4 PM THIS AFTERNOON TO MIDNIGHT EST
TONIGHT FOR MIZ007.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
UPDATE...JLA
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
631 AM EST FRI DEC 23 2011
UPDATED AVIATION DISCUSSION FOR 12Z TAFS
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL TROUGHING FROM
NE CANADA INTO THE CNTRL CONUS RESULTING IN NW FLOW FROM CNTRL
CANADA INTO THE GREAT LAKES. A PROMINENT UPSTREAM SHORTWAVE TROUGH
WAS LOCATED NEAR LAKE WINNIPEG. AT THE SFC...SRLY WINDS WERE
INCREASING OVER MN AND WRN LAKE SUPERIOR AHEAD OF LOW PRES OVER THE
SE CORNER OF MANITOBA. THE AREA OF WAA LIGHT SNOW HAD MOVED INTO NRN
MN WITH VSBYS DOWN TO 1-3SM. LINGERING SCT LIGHT LAKE EFFECT SNOW
SHOWERS OVER ERN LAKE SUPERIOR WERE QUICKLY DIMINISHING AND STARING
TO MOVE OFFSHORE AS THE RIDGE AXIS MOVES THROUGH AND WINDS BACK TO
THE SW.
&&
.DISCUSSION...
TODAY AND TONIGHT...EXPECT THE AREA OF SNOW TO MAKE STEADY PROGRESS
TO THE SE AS THE MANTITOBA CLIPPER SHORTWAVE AND LOW APPROACH THE
AREA. THE BAND OF MODERATE TO STRONG NET 280K ISENTROPIC ASCENT AND
700-300 MB QVECTOR CONV WILL SUPPORT GOING HIGHER END POPS ACROSS THE
CWA...MAINLY BTWN 18Z-24Z. HOWEVER...MOISTURE WILL BE LIMITED WITH
ONLY 1.0 1O 1.5 G/KG AVAILABLE IN THE 700-750 MB LAYER AND PWAT
VALUES OF AROUND 0.25 INCH. SO...ACCUMULATIONS SHOULD REMAIN
GENERALLY LIGHT...AT OR BELOW AN INCH. DOWNSLOPE SRLY FLOW MAY ALSO
REDUCE AMOUNTS NEAR LAKE SUPERIOR IN NORTH CENTRAL UPPER MI. 850 MB
TEMPS AROUND -10C SUPPORT POTENTIAL FOR SOME LAKE ENHANCED SNOW NEAR
LAKE MICHIGAN. WITH ONLY A BRIEF PERIOD OF DEEPER MOISTURE/LIFT
MOVING THROUGH ANY ADDITIONAL AMOUNTS WILL ALSO BE SMALL. THE BEST
CHANCE FOR MORE SIGNIFICANT SNOW AMOUNTS WILL BE EAST OF
MANISTIQUE...GIVEN PREDOMINANT 220-230 CBL FLOW LATE THIS AFTERNOON
AND EVENING.
WITH ONLY MODERATE INSTABILITY...THE SNOW WILL DIMINISH QUICKLY OVER
FROM WEST TO EAST IN THE EVENING AS THE SHORTWAVE MOVES THROUGH AND
SUBSIDENCE TAKES OVER. CLOUDS MAY ALSO DIMINISH LATE AS 925-850 MB
WEST FLOW DRY ADVECTION MOVES IN.
SATURDAY...DRY WEATHER IS EXPECTED AS THE FORCING AND ISENTROPIC
NEXT WEAKER CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE
CWA...PER GFS/ECMWF/GEM. 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.
THERE WAS GREATER UNCERTAINTY WITH POTENTIAL FOR LIGHT SYNOPTIC
LIGHT SNOW. THE GFS WAS FARTHER SOUTH WITH THIS FEATURE COMAPRED TO
THE ECMWF/GEM. WITH LITTLE MOISTURE AVBL...CHANCE POPS WERE CONFINED
TO LOCATIONS FAVORED BY WNW FLOW WHERE SOME LAKE ENHANCEMENT MAY
OCCUR WITH 850 MB TEMPS AROUND -10C.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILD INTO THE AREA WITH
STRGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. THE MILD PATTERN CONTINUES THROUGH MUCH OF THE WEEK
WITH ADDITIONAL CLIPPER SYSTEMS MOVING THROUGH. UNCERTAINTY IS
LARGER WITH STRENGTH OF CAA IN THE WAKE OF ANY SYSTEM. THE 00Z
GFS/GEM AND MAJORITY OF GFS ENS SUGGESTED THAT COLD AIR BY TUE INTO
TUE NIGHT WOULD REMAIN ONLY NEAR -10C WHILE THE 00Z ECMWF FCST H8
TEMPS DOWN TO -15C WHICH WOULD BRING GREATER CHANCE FOR SIGNFICANT
LES.
&&
.AVIATION /FOR THE 12Z TAF ISSUANCE/...
A CLIPPER SYSTEM DROPPING SE ACROSS UPPER MICHIGAN WILL SPREAD SNOW
ACROSS THE AREA FROM WEST TO EAST LATE THIS MORNING THROUGH EARLY
EVENING. HAVE CONTINUED ALT LANDING MINS FOR ALL SITES DURING THE
PEAK SNOW IN THE AFTN HRS. AS THE SYSTEM EXITS...EXPECT BORDERLINE
IFR CIGS TO CONTINUE BEFORE DIMINISHING OVERNIGHT. MODELS HINTING AT
LOW CLOUDS THROUGH A GOOD PORTION OF THE NIGHT AND WOULD HAVE LIKED
TO HAVE SEEN A LITTLE DEEPER MOISTURE TO GO WITH LOW CIGS AND SOME
VSBY REDUCTION AFTER 06Z.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH MODELS COMING TO A CONSENSUS ON LOW TRACK/INTENSITY ACROSS LAKE
SUPERIOR TODAY...HAVE ADJUSTED WINDS DOWN A TOUCH AND ONLY THINK
THERE WILL BE A PERIOD /LATE MORNING THROUGH THE AFTN/ OF SW GUSTS
UP TO 30KTS AHEAD OF THE LOW. WINDS SHOULD DIMINISH BELOW 20KTS
TONIGHT AS THE LOW DISSIPATES WHEN MOVING INTO THE LOWER GREAT
LAKES. SW WINDS WILL ONCE AGAIN BE ON THE INCREASE SAT AHEAD OF THE
NEXT TROUGH TO AFFECT LK SUPERIOR. THIS STRONGER TROUGH WILL PRODUCE
WINDS UP TO 30KTS SAT INTO SUN...AS WINDS GRADUALLY SHIFT TO THE NW
BY SUN WITH THE TROUGH PUSHING EAST. THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS TO 35KTS DURING THAT PERIOD. AFTER A BRIEF REPRIVE
ON SUN NIGHT...THE NEXT TROUGH WILL AFFECT LK SUPERIOR MON INTO MON
NIGHT. WITH THIS TROUGH EVEN STRONGER...APPEARS TO BE A GOOD CHANCE
OF SEEING SW GALES TO 35KTS OVER MUCH OF LAKE SUPERIOR MON
AFTN/NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...SRF
MARINE...SRF
AREA FORECAST DISCUSSION
NWS MARQUETTE MI
546 AM EST FRI DEC 23 2011
.SYNOPSIS...
WV IMAGERY AND RUC ANALYSIS INDICATED MID/UPPER LEVEL TROUGHING FROM
NE CANADA INTO THE CNTRL CONUS RESULTING IN NW FLOW FROM CNTRL
CANADA INTO THE GREAT LAKES. A PROMINENT UPSTREAM SHORTWAVE TROUGH
WAS LOCATED NEAR LAKE WINNIPEG. AT THE SFC...SRLY WINDS WERE
INCREASING OVER MN AND WRN LAKE SUPERIOR AHEAD OF LOW PRES OVER THE
SE CORNER OF MANITOBA. THE AREA OF WAA LIGHT SNOW HAD MOVED INTO NRN
MN WITH VSBYS DOWN TO 1-3SM. LINGERING SCT LIGHT LAKE EFFECT SNOW
SHOWERS OVER ERN LAKE SUPERIOR WERE QUICKLY DIMINISHING AND STARING
TO MOVE OFFSHORE AS THE RIDGE AXIS MOVES THROUGH AND WINDS BACK TO
THE SW. &&
.DISCUSSION...
TODAY AND TONIGHT...EXPECT THE AREA OF SNOW TO MAKE STEADY PROGRESS
TO THE SE AS THE MANTITOBA CLIPPER SHORTWAVE AND LOW APPROACH THE
AREA. THE BAND OF MODERATE TO STRONG NET 280K ISENTROPIC ASCENT AND
700-300 MB QVECTOR CONV WILL SUPPORT GOING HIGHER END POPS ACROSS THE
CWA...MAINLY BTWN 18Z-24Z. HOWEVER...MOISTURE WILL BE LIMITED WITH
ONLY 1.0 1O 1.5 G/KG AVAILABLE IN THE 700-750 MB LAYER AND PWAT
VALUES OF AROUND 0.25 INCH. SO...ACCUMULATIONS SHOULD REMAIN
GENERALLY LIGHT...AT OR BELOW AN INCH. DOWNSLOPE SRLY FLOW MAY ALSO
REDUCE AMOUNTS NEAR LAKE SUPERIOR IN NORTH CENTRAL UPPER MI. 850 MB
TEMPS AROUND -10C SUPPORT POTENTIAL FOR SOME LAKE ENHANCED SNOW NEAR
LAKE MICHIGAN. WITH ONLY A BRIEF PERIOD OF DEEPER MOISTURE/LIFT
MOVING THROUGH ANY ADDITIONAL AMOUNTS WILL ALSO BE SMALL. THE BEST
CHANCE FOR MORE SIGNIFICANT SNOW AMOUNTS WILL BE EAST OF
MANISTIQUE...GIVEN PREDOMINANT 220-230 CBL FLOW LATE THIS AFTERNOON
AND EVENING.
WITH ONLY MODERATE INSTABILITY...THE SNOW WILL DIMINISH QUICKLY OVER
FROM WEST TO EAST IN THE EVENING AS THE SHORTWAVE MOVES THROUGH AND
SUBSIDENCE TAKES OVER. CLOUDS MAY ALSO DIMINISH LATE AS 925-850 MB
WEST FLOW DRY ADVECTION MOVES IN.
SATURDAY...DRY WEATHER IS EXPECTED AS THE FORCING AND ISENTROPIC
NEXT WEAKER CLIPPER SHRTWV IS EXPECTED TO REMAIN NORTH OF THE
CWA...PER GFS/ECMWF/GEM. 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.
THERE WAS GREATER UNCERTAINTY WITH POTENTIAL FOR LIGHT SYNOPTIC
LIGHT SNOW. THE GFS WAS FARTHER SOUTH WITH THIS FEATURE COMAPRED TO
THE ECMWF/GEM. WITH LITTLE MOISTURE AVBL...CHANCE POPS WERE CONFINED
TO LOCATIONS FAVORED BY WNW FLOW WHERE SOME LAKE ENHANCEMENT MAY
OCCUR WITH 850 MB TEMPS AROUND -10C.
MONDAY THROUGH THURSDAY...MID LEVEL RIDGING BUILD INTO THE AREA WITH
STRGER SW FLOW MON...BOOSTING TEMPS WELL ABOVE NORMAL...INTO THE MID
TO UPPER 30S. THE MILD PATTERN CONTINUES THROUGH MUCH OF THE WEEK
WITH ADDITIONAL CLIPPER SYSTEMS MOVING THROUGH. UNCERTAINTY IS
LARGER WITH STRENGTH OF CAA IN THE WAKE OF ANY SYSTEM. THE 00Z
GFS/GEM AND MAJORITY OF GFS ENS SUGGESTED THAT COLD AIR BY TUE INTO
TUE NIGHT WOULD REMAIN ONLY NEAR -10C WHILE THE 00Z ECMWF FCST H8
TEMPS DOWN TO -15C WHICH WOULD BRING GREATER CHANCE FOR SIGNFICANT
LES.
&&
.AVIATION /FOR THE 06Z TAF ISSUANCE/...
ALTHOUGH THERE WL BE QUITE A BIT OF CLD COVER...EXPECT VFR
CONDITIONS TO PERSIST THRU LATE MRNG AT ALL 3 SITES WITH RELATIVELY
DRY LLVL AIR UNDER WEAK SFC RDG AXIS. AS THE NEXT CLIPPER LO PRES
NOW IN SCNTRL CAN AND ACCOMPANYING AREA OF -SN MOVES TOWARD THE UPR
LKS LATER TDAY...EXPECT DETERIORATING CONDITIONS TO MVFR THEN IFR
ALONG WITH A GUSTY S WIND. ALTHOUGH THE STEADIER SN WL END W-E LATE
IN THE DAY...LO CLDS AND NO BETTER THAN MVFR CONDITIONS WL LINGER.
&&
.MARINE /FOR THE 4AM LAKE SUPERIOR FORECAST ISSUANCE/...
WITH MODELS COMING TO A CONSENSUS ON LOW TRACK/INTENSITY ACROSS LAKE
SUPERIOR TODAY...HAVE ADJUSTED WINDS DOWN A TOUCH AND ONLY THINK
THERE WILL BE A PERIOD /LATE MORNING THROUGH THE AFTN/ OF SW GUSTS
UP TO 30KTS AHEAD OF THE LOW. WINDS SHOULD DIMINISH BELOW 20KTS
TONIGHT AS THE LOW DISSIPATES WHEN MOVING INTO THE LOWER GREAT
LAKES. SW WINDS WILL ONCE AGAIN BE ON THE INCREASE SAT AHEAD OF THE
NEXT TROUGH TO AFFECT LK SUPERIOR. THIS STRONGER TROUGH WILL PRODUCE
WINDS UP TO 30KTS SAT INTO SUN...AS WINDS GRADUALLY SHIFT TO THE NW
BY SUN WITH THE TROUGH PUSHING EAST. THERE COULD BE A FEW ISOLATED
GALE FORCE GUSTS TO 35KTS DURING THAT PERIOD. AFTER A BRIEF REPRIVE
ON SUN NIGHT...THE NEXT TROUGH WILL AFFECT LK SUPERIOR MON INTO MON
NIGHT. WITH THIS TROUGH EVEN STRONGER...APPEARS TO BE A GOOD CHANCE
OF SEEING SW GALES TO 35KTS OVER MUCH OF LAKE SUPERIOR MON
AFTN/NIGHT.
&&
.MQT WATCHES/WARNINGS/ADVISORIES...
UPPER MICHIGAN...
NONE.
LAKE SUPERIOR...
NONE.
LAKE MICHIGAN...
NONE.
&&
$$
SYNOPSIS...JLB
DISCUSSION...JLB
AVIATION...KC
MARINE...SRF
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
623 PM CST SAT DEC 24 2011
.UPDATE...
00Z AVIATION DISCUSSION ADDED BELOW.
&&
.DISCUSSION...
NOT MUCH CHANGE IN THE OVERALL WEATHER PATTERN THAT HAS PERSISTED
ACROSS MUCH OF THE UPPER MIDWEST THE PAST FEW WEEKS. AN UPPER HIGH
PRESSURE RIDGE OVER THE WESTERN CONUS AND WEAK UPPER LEVEL TROUGH
OVER THE EASTERN U.S. WILL PERSIST OVER NORTH AMERICA WITH ONLY
MINOR DEGRADATION OF THE WESTERN UPPER RIDGE FORESEEN IN THE LONG
TERM. TEMPERATURES WILL BE THE MAIN FORECAST CHALLENGE. THE LACK
OF ANY SIGNIFICANT SNOW COVER...AND A LOT OF OPEN AND BARE GROUND
OVER A VAST PART OF THE UPPER MIDWEST WILL CONTINUE TO AID IN
OBSERVING ABOVE NORMAL TEMPERATURES. MAX TEMPS SUNDAY AND MONDAY
WILL WARM WELL INTO THE UPPER 30S AND 40S. MAX TEMPS MIX DOWN FROM
925 MB THIS TIME OF YEAR AND WITHOUT THE EFFECTS OF CLOUDS/SNOW
COVER...TEMPS SHOULD WARM EASILY INTO THE 40S MOST LOCATIONS.
NOT MUCH IN THE WAY OF PRECIP EXPECTED OVER THE NEXT FIVE DAYS. A
COUPLE OF WEAK WEATHER DISTURBANCES WILL PASS WELL TO THE NORTH
AND SOUTH OF OUR FORECAST AREA. THESE SYSTEMS COULD BRING SOME
LIGHT SNOW OR SNOW FLURRIES TO PARTS OF CENTRAL MN THURSDAY NIGHT
INTO THE NEW YEARS HOLIDAY WEEKEND.
BY THE WEEKEND...THE LONG TERM MODELS SHOWED A TROUGH DEVELOPING
OVER THE UPPER MIDWEST. THIS WILL BRING A BETTER THREAT FOR SOME
PRECIPITATION.
&&
.AVIATION.../00Z TAF ISSUANCE/
UPPER WAVE QUICKLY MOVING ACROSS THE AIRSPACE THIS EVENING WILL
BE SENDING MID/UPPER CLOUDS THROUGH ABOUT 06Z...WHEN SKC
CONDITIONS RETURN FOR A BIT. AFTER THAT...WILL HAVE TO WATCH
STRATUS UP BY LAKE WINNIPEG THAT IS DIVING SOUTH TOWARD MN RIGHT
NOW. BY 09Z...THE RUC HAS STRATUS DOWN TO A DLH/BJI/HCO LINE. THE
NAM/GFS ALONG WITH SREF PROBS TAKE THESE CIGS SE INTO WI...BUT THE
GFS IN PARTICULAR HAS LOWER CIGS GETTING CLOSE TO AXN/STC/MSP.
HOWEVER...00Z SOUNDING AT KMPX SHOWS BIGGEST PROBLEM THESE CLOUD
WILL ENCOUNTER DOWN HERE...VERY DRY AIR BLW 120. EAU HAS HIGHEST
CONFIDENCE IN STRATUS FOR THE MORNING...SO UPPED THE SKY COVER
THERE. BY THE AFTERNOON...RIDGING WILL BE MOVING BACK IN...WITH
SKC CONDITIONS RETURNING FROM W TO E. FOR WINDS...GRADIENT WILL
REMAIN TIGHT TONIGHT...WITH SUSTAINED WINDS BASICALLY REMAINING
ABOVE 10KTS...WITH AN OCCASIONAL GUST UP AROUND 20 KTS. FOR
DIRECTIONS...WILL CONTINUE TREND THIS TAF PERIOD OF WINDS SWAPPING
BETWEEN THE SW AND NW EVERY 12 HRS AS DRY FRONTS ZIP ACROSS THE
REGION.
KMSP...ONLY CONCERN THIS PERIOD WILL BE FOR THE POSSIBILITY OF
SOME STRATUS DOWN TO ABOUT 025 SUNDAY MORNING. WILL BE IN CYCLONIC
FLOW THROUGH THE MORNING...BUT WE HAVE A LOT OF MOISTENING TO
DO. SREF PROBS FOR CIGS BLW 030 COMING UP TO ABOUT 40% AT 15Z AND
CU RULES OFF THE NAM GO BELOW ZERO...SO ADDED A FEW030 TO ACCOUNT
FOR AT LEAST THE DEVELOPMENT OF SOME CU. CONFIDENCE IS HIGH IN THE
REST OF THE FORECAST.
&&
.MPX WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
&&
$$
JVM/MPG
AREA FORECAST DISCUSSION
NWS BUFFALO NY
720 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/...
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 /01Z SUNDAY THROUGH THURSDAY/...
A NARROW BAND VFR CLOUDS ASSOCIATED WITH AN APPROACHING WARM FRONT
WILL SPREAD EAST ACROSS THE AREA THIS EVENING AND OVERNIGHT. WITH
RELATIVELY DRY AIR IN THE MID LEVELS OF THE ATMOSPHERE...THE CHANCES
FOR SNOW WILL REMAIN LOW. BEHIND THE FRONT...MID AND HIGH LEVEL
CLOUDS WILL PREDOMINATE. ON SUNDAY...THE MID LEVEL CLOUDS WILL GIVE
WAY TO A LOWERING VFR DECK AS MOISTURE INCREASES AHEAD OF AN
APPROACHING SHORT WAVE AND ITS ASSOCIATED COLD FRONT. SCATTERED RAIN
AND SNOW SHOWERS ACCOMPANYING THE FRONT MAY LOWER CONDITIONS TO MVFR
TOWARD THE END OF THE TAF PERIOD.
THE LATEST GUIDANCE SHOWS A 35 TO 40 KNOT LOW LEVEL JET SETTING UP
BEHIND THE WARM FRONT. THIS MAY RESULT IN A PERIOD OF MARGINAL LLWS
FROM ABOUT 06Z TO 12Z WHEN WARM AIR ADVECTION WILL PREVENT THE
TRANSFER OF HIGHER WINDS ALOFT TO THE SURFACE. BETTER MIXING WILL
ALLOW GUSTIER WINDS TO REACH THE SURFACE ON SUNDAY. GUSTS UP TO 35
KNOTS ARE POSSIBLE...ESPECIALLY VCNTY KART/KJHW WHERE FUNNELING OF
THE WINDS UP LAKE ERIE WILL COME IN PLAY.
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/TJP
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...TJP
MARINE...APFFEL/WCH
CLIMATE...THOMAS/HITCHCOCK/JJR
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
953 AM EST FRI DEC 23 2011
.SYNOPSIS...
LOW PRESSURE OFF THE NEW ENGLAND COAST WILL MOVE AWAY FROM THE AREA
TODAY...WITH RAIN AND SNOW TAPERING OFF THIS MORNING. A SERIES OF
WEAK UPPER LEVEL DISTURBANCES WILL BRING PERIODS OF CLOUDS TO THE
AREA THIS HOLIDAY WEEKEND BUT DRY WEATHER IS EXPECTED. A STRONGER
SYSTEM WILL APPROACH SUNDAY NIGHT WITH A BETTER CHANCE FOR SNOW
SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATE 10 AM...KBGM RADAR SHOWS WEAK RETURNS OVER NRN CWA AND
PARTS OF THE SUSQU REGION. ACTIVITY STILL PRIMARILY RAIN WITH A
RAIN/SNOW MIX IN THE HIGHER ELEVATIONS. WILL CONTINUE TO ADVERTISE
CHC POPS ACROSS MUCH OF CENTRAL NY THROUGH MIDDAY THEN JUST CHC
DOWNWIND OF LAKE ONTARIO THIS AFTERNOON IN POSSIBLE WEAK LAKE
EFFECT RESPONSE. TWEAKED WX GRIDS TO INDICATE RAIN/SNOW SHOWER MIX
WITH TRANSITION TO JUST SNOW SHOWERS NOT UNTIL EARLY AFTERNOON. NO
SNOW ACCUM EXPECTED. TEMPS WILL HOLD NEARLY STEADY THROUGH LATE
MORNING THEN SLOWLY DROP THIS AFTERNOON IN BETTER CAA.
UPDATED AT 620 AM...TWEEKS TO CRNT FCST WHICH APPEARS TO BE ON
TRACK. STEADIER PCPN IS MOVG OUT ABOUT AN HOUR AHEAD OF SCHEDULE...AND
HAVE LOWERED POPS ACCORDINGLY. NEVER DID COMPLETELY SWITCHOVER TO
SNOW ON THE HILL AT BGM! PREV BLO...
HEAVIEST PCPN IS ALREADY BEGINNING TO MOVE OUT OF THE RGN. PEO AND
DSV REPRTING -SN AND WE`RE MIXING OVER AT BGM AT 3 AM. WE SUSPECT
THAT IS IS ALSO SNOWING ACRS THE HIGHER ELEVATIONS OF THE WRN
CATSKILLS. ACTIVITY WILL CONTINUE TO WIND DOWN THIS MORNING. WILL
CONTINUE TO TWEEKS GRIDS AS NEEDED DURING THE MORNING CHGOVR...BUT
THINK CRNT FCST SNOW AMTS ARE IN THE BALLPARK...WITH BEST CHC N OF
THE NY/PA BORDER ACRS THE HIER ELEVATIONS OF THE CNTRL SRN
TIER/SUSQ RGN WHERE AN INCH IS PSBL...AND MAYBE 2 0R 3 INCHES OVER
ERN DELAWARE COUNTY. LATER TDA AS A CLDER NW FLOW SETS UP...WE
SHOULD SEE A WEAK LAKE RESPONSE WITH SCT -SHSN AND FLURRIES. THIS
ACTIVITY IS XPCTD TO DIMINISH EARLY THIS EVNG. TEMPS TDA STEADY OR
SLOWLY FALLING FROM EARLY MRNG READINGS WITH MINS TNGT GNRLY IN
THE TEENS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THIS PERIOD WILL SEE NW FLOW ALOFT WITH WEAK EMBEDDED...MOSTLY
MOISTURE STARVED S/WV`S. ONE PASSES FRI NGT...ANOTHER SAT NGT AND
A STRONGER ONE FOR SUN NGT. MAIN EFFECT OF THE FIRST FEW WAVES
WILL BE TO BRING PDS OF CLOUDINESS TO THE RGN..,BUT THE MORE
POTENT SUNDAY NGT WAVE COULD SPREAD SNOW SHOWERS INTO THE AREA.
ALL IN ALL A VERY QUIET HOLIDAY WEEKEND WITH A MODERATING TEMPS ON
SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
3 AM UPDATE...WE START OFF THE LONG TERM PERIOD WITH A BRIEF PERIOD OF LAKE
EFFECT SNOW EARLY MONDAY BEFORE THE COLDER AIR QUICKLY LIFTS OUT.
PREFER HPC GUIDANCE WHICH LEANS HEAVILY TOWARD THE EURO WHICH IS
MUCH MORE AMPLIFIED AND WARMER THAN THE GFS WITH A COLD FRONT
MOVING TOWARD OUR AREA ON TUESDAY. THIS PATTERN SEEMS TO MAKE THE
MOST SENSE GIVEN OUR PROGRESSIVE...SOUTHWESTERLY FLOW THAT WE HAVE
BEEN IN FOR AWHILE NOW. AFTER ANY SHOWERS TUESDAY...BEHIND THE
FRONT WE DO TURN COLD ENOUGH FOR A PERIOD OF LIGHT SNOW TUESDAY
NIGHT. WE WILL BE BRIEFLY COLD ENOUGH FOR LAKE SNOWS EARLY
WEDNESDAY BEFORE HIGH PRESSURE BRINGS A RETURN TO DRIER WEATHER.
&&
.AVIATION /15Z FRIDAY THROUGH TUESDAY/...
7 AM UPDATE...PRECIPITATION WILL CONTINUE TO PULL OUT OF THE AREA
BY 15Z WITH SLOW IMPROVEMENT EXPECTED AS THIS HAPPENS. IN THE
MEANTIME SOME IFR VSBYS POSSIBLE AT KRME IN SNOW...WITH MVFR VSBYS
AT KSYR IN A RAIN/SNOW MIX. FARTHER SOUTH BOTH KITH AND KBGM HAVE
SEEN CLOUD BASES DROP LOW ENOUGH TO PRODUCE PERIODS OF LIFR CIGS
AND VSBYS AT TIMES. FEEL THIS WILL CONTINUE FOR A FEW MORE HOURS
BEFORE GRADUALLY IMPROVING TO IFR AND EVENTUALLY MVFR BY LATE
MORNING/EARLY AFTERNOON. MVFR CIGS EXPECTED TO CONTINUE AT KELM
AND KAVP THROUGH LATE MORNING BUT THESE TERMINALS ARE EXPECTED TO
STAY DRY.
BY AFTERNOON CONFIDENCE LOWERS AS HIGHER RESOLUTION MODELS SUCH AS
THE HRRR CONTINUE TO SHOW MVFR CIGS AT ALL TERMINALS THROUGH
22Z...WHILE NAM BUFKIT SOUNDINGS...WHICH USUALLY OVERDO THE
MOISTURE...SHOW VFR CIGS RETURNING DURING THIS TIME. WITH A COLD
NORTHWEST FLOW BELIEVE THE HRRR WILL BE CORRECT AND KEEP MVFR
GOING THROUGH 22Z BEFORE VFR RETURNS BY 0Z.
.OUTLOOK...
SAT/SUN...VFR.
SUN NIGHT INTO MONDAY...MVFR POSSIBLE IN LIGHT SNOW.
LATER MONDAY INTO MONDAY NIGHT...VFR.
TUE...MVFR IN RAIN SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...RRM
SHORT TERM...
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
650 AM EST FRI DEC 23 2011
.SYNOPSIS...
LOW PRESSURE OFF THE NEW ENGLAND COAST WILL MOVE AWAY FROM THE AREA
TODAY...WITH RAIN AND SNOW TAPERING OFF THIS MORNING. A SERIES OF
WEAK UPPER LEVEL DISTURBANCES WILL BRING PERIODS OF CLOUDS TO THE
AREA THIS HOLIDAY WEEKEND BUT DRY WEATHER IS EXPECTED. A STRONGER
SYSTEM WILL APPROACH SUNDAY NIGHT WITH A BETTER CHANCE FOR SNOW
SHOWERS.
&&
.NEAR TERM /THROUGH TONIGHT/...
UPDATED AT 620 AM...TWEEKS TO CRNT FCST WHICH APPEARS TO BE ON
TRACK. STEADIER PCPN IS MOVG OUT ABOUT AN HOUR AHEAD OF SCHEDULE...AND
HAVE LOWERED POPS ACCORDINGLY. NEVER DID COMPLETELY SWITCHOVER TO
SNOW ON THE HILL AT BGM! PREV BLO...
HEAVIEST PCPN IS ALREADY BEGINNING TO MOVE OUT OF THE RGN. PEO AND
DSV REPRTING -SN AND WE`RE MIXING OVER AT BGM AT 3 AM. WE SUSPECT
THAT IS IS ALSO SNOWING ACRS THE HIGHER ELEVATIONS OF THE WRN
CATSKILLS. ACTIVITY WILL CONTINUE TO WIND DOWN THIS MORNING. WILL
CONTINUE TO TWEEKS GRIDS AS NEEDED DURING THE MORNING CHGOVR...BUT
THINK CRNT FCST SNOW AMTS ARE IN THE BALLPARK...WITH BEST CHC N OF
THE NY/PA BORDER ACRS THE HIER ELEVATIONS OF THE CNTRL SRN
TIER/SUSQ RGN WHERE AN INCH IS PSBL...AND MAYBE 2 0R 3 INCHES OVER
ERN DELAWARE COUNTY. LATER TDA AS A CLDER NW FLOW SETS UP...WE
SHOULD SEE A WEAK LAKE RESPONSE WITH SCT -SHSN AND FLURRIES. THIS
ACTIVITY IS XPCTD TO DIMINISH EARLY THIS EVNG. TEMPS TDA STEADY OR
SLOWLY FALLING FROM EARLY MRNG READINGS WITH MINS TNGT GNRLY IN
THE TEENS.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
THIS PERIOD WILL SEE NW FLOW ALOFT WITH WEAK EMBEDDED...MOSTLY
MOISTURE STARVED S/WV`S. ONE PASSES FRI NGT...ANOTHER SAT NGT AND
A STRONGER ONE FOR SUN NGT. MAIN EFFECT OF THE FIRST FEW WAVES
WILL BE TO BRING PDS OF CLOUDINESS TO THE RGN..,BUT THE MORE
POTENT SUNDAY NGT WAVE COULD SPREAD SNOW SHOWERS INTO THE AREA.
ALL IN ALL A VERY QUIET HOLIDAY WEEKEND WITH A MODERATING TEMPS ON
SUNDAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
3 AM UPDATE...WE START OFF THE LONG TERM PERIOD WITH A BRIEF PERIOD OF LAKE
EFFECT SNOW EARLY MONDAY BEFORE THE COLDER AIR QUICKLY LIFTS OUT.
PREFER HPC GUIDANCE WHICH LEANS HEAVILY TOWARD THE EURO WHICH IS
MUCH MORE AMPLIFIED AND WARMER THAN THE GFS WITH A COLD FRONT
MOVING TOWARD OUR AREA ON TUESDAY. THIS PATTERN SEEMS TO MAKE THE
MOST SENSE GIVEN OUR PROGRESSIVE...SOUTHWESTERLY FLOW THAT WE HAVE
BEEN IN FOR AWHILE NOW. AFTER ANY SHOWERS TUESDAY...BEHIND THE
FRONT WE DO TURN COLD ENOUGH FOR A PERIOD OF LIGHT SNOW TUESDAY
NIGHT. WE WILL BE BRIEFLY COLD ENOUGH FOR LAKE SNOWS EARLY
WEDNESDAY BEFORE HIGH PRESSURE BRINGS A RETURN TO DRIER WEATHER.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
7 AM UPDATE...PRECIPITATION WILL CONTINUE TO PULL OUT OF THE AREA
BY 15Z WITH SLOW IMPROVEMENT EXPECTED AS THIS HAPPENS. IN THE
MEANTIME SOME IFR VSBYS POSSIBLE AT KRME IN SNOW...WITH MVFR VSBYS
AT KSYR IN A RAIN/SNOW MIX. FARTHER SOUTH BOTH KITH AND KBGM HAVE
SEEN CLOUD BASES DROP LOW ENOUGH TO PRODUCE PERIODS OF LIFR CIGS
AND VSBYS AT TIMES. FEEL THIS WILL CONTINUE FOR A FEW MORE HOURS
BEFORE GRADUALLY IMPROVING TO IFR AND EVENTUALLY MVFR BY LATE
MORNING/EARLY AFTERNOON. MVFR CIGS EXPECTED TO CONTINUE AT KELM
AND KAVP THROUGH LATE MORNING BUT THESE TERMINALS ARE EXPECTED TO
STAY DRY.
BY AFTERNOON CONFIDENCE LOWERS AS HIGHER RESOLUTION MODELS SUCH AS
THE HRRR CONTINUE TO SHOW MVFR CIGS AT ALL TERMINALS THROUGH
22Z...WHILE NAM BUFKIT SOUNDINGS...WHICH USUALLY OVERDO THE
MOISTURE...SHOW VFR CIGS RETURNING DURING THIS TIME. WITH A COLD
NORTHWEST FLOW BELIEVE THE HRRR WILL BE CORRECT AND KEEP MVFR
GOING THROUGH 22Z BEFORE VFR RETURNS BY 0Z.
.OUTLOOK...
SAT/SUN...VFR.
SUN NIGHT INTO MONDAY...MVFR POSSIBLE IN LIGHT SNOW.
LATER MONDAY INTO MONDAY NIGHT...VFR.
TUE...MVFR IN RAIN SHOWERS.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...
NEAR TERM...
SHORT TERM...
LONG TERM...HEDEN
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1250 AM EST FRI DEC 23 2011
.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL MOVE INTO THE MID ATLANTIC
REGION OVERNIGHT THEN OFF THE NEW JERSEY COAST BY MORNING. THIS
SYSTEM WILL SPREAD RAIN OVER THE REGION THIS EVENING WHICH WILL
GRADUALLY CHANGE TO WET SNOW OVERNIGHT. MINOR SNOW ACCUMULATIONS
ARE LIKELY ACROSS CENTRAL NEW YORK, ESPECIALLY IN THE HIGHER
TERRAIN. THE REST OF THE HOLIDAY WEEKEND WILL BE COOLER WITH
TEMPERATURES CLOSER TO NORMAL ALONG WITH DRY CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM THIS MORNING/...
MIDNIGHT UPDATE...WE HAVE MADE SOME TWEEKS TO THE NEAR TERM. SFC
TEMPS WERE RUNNING A BIT ON THE COOL SIDE AND HAVE RAISED THEM A
FEW DEG OVER THE NXT 3-6 HRS. AS FOR PCPN...WE ARE LEANING TWDS
THE RUC AND OUR LCL WRF WHICH INDICATES A SLIGHTLY LATER CHGOVR
AND THEREFORE LESSER SNOW ACCUMS. DOUBT WE`LL SEE MUCH SNOW S OF
THE NY/PA BORDER...WITH BEST CHC N OF THE NY/PA BORDER ACRS THE
HIER ELEVATIONS OF THE CNTRL SRN TIER/SUSQ RGN WHERE AN INCH IS
PSBL...AND MAYBE 2 0R 3 INCHES OVER ERN DELAWARE COUNTY. PREV BLO...
10 PM UPDATE... PCPN HAS NOW ENVELOPED ALL BUT OUR FAR SERN
ZNS...AND IT SHOULD DEVELOP THERE AS WELL BY ARND 05Z. SAT IMAGERY
SHOWS A WELL DEVELOPED UPR-LVL WV APPROACHING FROM THE SW (AS
EVIDENCED BY NICE BAROCLINIC LEAF SIG)...WITH IMPROVING UPR-LVL
JET DYNAMICS. BEST/STEADIEST PCPN WILL OCCUR BETWEEN NOW AND ABT
10-12Z...WITH A FAIRLY RAPID DEPARTURE FROM SW TO NE THEREAFTER.
SFC TEMPS ARE WELL ABV FRZG ATTM ALL THE WAY BACK TO SRN
ONT...LENDING CREDENCE TO OUR FCST OF ONLY A GRADUAL CHG OVER TO
SNOW DURG THE NGT. WE`LL RIDE WITH OUR CURRENT FCST OF GENERALLY
1-3" OF SNOW (MOSTLY HIGHER ELEVS) ACRS MUCH OF CNY AND PA`S NRN
BORDER CNTYS...WITH LITTLE OR NOTHING DOWN TWDS THE WYO/LACK VLYS.
745 PM UPDATE... STEADIER PCPN IS SLOWLY OVERSPREADING THE AREA
FROM SW TO NE ATTM. THE INITIAL STRIPE OF PCPN SHOULD IMPACT OUR
NRN ZNS (FINGER LAKES RGN)...AS BETTER FGEN FORCING WILL RESIDE
HERE PRIOR TO 06Z. THEREAFTER...PCPN SHOULD RAPIDLY DEVELOP ACRS THE
ENTIRE FA...AS MOIST ADVECTION/UPPER JET DYNAMICS MAXIMIZE IN THE
06-12Z TIME FRAME.
IT CERTAINLY APPEARS THAT BLYR TEMPS WILL DICTATE PTYPE
OVERNIGHT...AS NO WARM LYR SEEMS EVIDENT ON MODEL SNDGS. GIVEN
MILD SFC TEMPS OUT THERE EARLY THIS EVE...IT SHOULD TAKE QUITE A
WHILE FOR SNOW TO MIX IN...SPCLY IN THE VLYS. WE`RE STILL GOING
FOR A CHANGE OVER TO SNOW FROM NW TO SE AFTER 06Z...MAINLY ON THE
HILLTOPS...REACHING THE TWIN TIERS IN THE 09-12Z TIME PD. THE
WYO/LACK VLYS LOOK TO STAY PRIMARILY RAIN FOR THE ENTIRE EVENT.
PREV DISC... A FAIRLY STRONG FAST MOVING WAVE WILL LIFT NORTHEAST
INTO THE MID ATLANTIC REGION BY MIDNIGHT THEN OFF THE NEW JERSEY
COAST BY 12Z FRIDAY. THIS SYSTEM WILL QUICKLY SPREAD LIGHT RAIN
OVER THE REGION THIS EVENING. PRECIP TYPE WITH THIS SYSTEM WILL BE
DETERMINED BY BOUNDARY LAYER TEMPS. MODEL SOUNDINGS AND T925 PROGS
INDICATE PRECIP WILL FALL JUST AS RAIN THROUGH 06Z THEN GRADUALLY
CHANGE TO WET SNOW ACROSS CENTRAL NEW YORK AS COLD AIR BUILDS IN
BEHIND WAVE. SNOW ACCUMS WILL BE HIGHLY ELEVATION DEPENDENT WITH
THE HIGHER ELEVATIONS ACROSS CNTRL NY POSSIBLY GETTING 1 TO 2
INCHES. IN OTSEGO/DELAWARE COUNTIES ACCUMS NEAR 3 INCHES ARE
POSSIBLE. FURTHER SOUTH IN THE WYOMING VALLEY, PIKE AND SULLIVAN
COUNTIES CONDITIONS WILL REMAIN TOO WARM FOR ANY ACCUMS.
LOWS BY DAYBREAK WILL FALL INTO LOWER TO MIDDLE 30S BY READINGS
AROUND 40 IN THE WYOMING VALLEY.
&&
.SHORT TERM /6 AM THIS MORNING THROUGH SUNDAY/...
FRIDAY...SFC WAVE WILL LIFT NORTHEAST QUICKLY WITH ANY REMAINING
ACTIVITY PULLING OUT OF THE EASTERN CWA BY 15Z. BEHIND SYSTEM A
NORTHWEST FLOW OF COLDER AIR WILL DEVELOP WITH HIGHER POPS
ADVERTISED DOWNWIND OF LAKE ONTARIO DUE TO POSSIBLE LES SNOW
SHOWERS. MAX TEMPS WILL RANGE FROM THE MID 30 TO AROUND 40.
FRIDAY NIGHT...SFC HIGH PRES NOSES DOWN FROM EASTERN CANADA WITH
SKIES BECOMING PARTLY CLOUDY. T85 DROPS ENOUGH FOR LES BUT WEAK
FLOW AND FAIRLY DRY AIRMASS WILL LIMIT ANY ACTIVITY. WILL JUST
CONTINUE WITH CHC/SLIGHT CHC POPS IN WESTERLY FLOW. LOWS WILL
RANGE FROM THE UPPER TEENS TO MID 20S.
SATURDAY THROUGH CHRISTMAS...A FAIRLY DRY PERIOD WITH NEAR
SEASONAL TEMPS. A WEAK WARM FRONT TO OUR WEST ON SATURDAY WILL
BRING MORE CLOUDS ACROSS THE AREA BUT ANY PRECIP WILL STAY WELL
WEST/NORTH OF REGION. MAX TEMPS SATURDAY WILL RANGE IN THE 30S.
SATURDAY NIGHT INTO CHRISTMAS, SFC HIGH PRES ALONG THE ATLANTIC
COAST WILL PROVIDE A SLIGHT TEMP MODERATION UNDER SOUTHWEST FLOW.
LATE CHRISTMAS DAY AN APPROACHING TROF WILL BRING A CHANCE FOR
RAIN/SNOW SHOWERS TOWARD EVENING ESPECIALLY IN THE WESTERN FA. MAX
TEMPS ON CHRISTMAS WILL RANGE IN THE MID 30S TO AROUND 40.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MODELS IN SOMEWHAT DECENT AGREEMENT FOR THE EXTENDED FORECAST.
THERE WILL BE AN UPPER LEVEL TROUGH AND A SFC LOW MOVING ACROSS
THE NORTHEASTERN US SUNDAY NIGHT. THIS WILL BRING A CHANCE OF SNOW
TO THE AREA. THIS SYSTEM QUICKLY CLEARS OUT AND HIGH PRESSURE
BUILDS IN FOR TUESDAY. BY TUESDAY NIGHT, A LOW PASSES TO THE NORTH
OF THE CWA AND LOOKS TO JUST BRING SOME CLOUDS TO THE AREA ATTM.
THEN, ANOTHER RIDGE OF HIGH PRESSURE SETS UP FOR WEDNESDAY THROUGH
THURSDAY MORNING. FOR WEDNESDAY NIGHT AND THURSDAY, MODELS DO
DIVERGE SOMEWHAT, WITH THE ECMWF HOLDING ONTO THE HIGH PRESSURE
LONGER THEN THE GFS, WHICH HAS A LOW APPROACHING THE CWA FROM THE
WEST. EITHER WAY, MOST OF THE WEEK LOOKS PRETTY QUIET WEATHER WISE
WITH TEMPS LIKELY ABOVE NORMAL.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
1 AM UPDATE...OUTSIDE OF KAVP...IFR CIGS LIKELY TO DEVELOP ACROSS
ALL TERMINALS OVER THE NEXT FEW HOURS. THE EXACT TIMING OF WHEN
THIS WILL OCCUR STILL A BIT UNCERTAIN BUT OVERALL CONFIDENCE IS
HIGH THAT IFR CIGS WILL DEVELOP. SOME LIFR CIGS ARE POSSIBLE AT
KITH AND KBGM DUE TO THE ELEVATION. GENERALLY SPEAKING VSBYS WILL
REMAIN IN THE MVFR RANGE IN RAIN. GRADUALLY HOWEVER SOME IFR VSBYS
WILL BE POSSIBLE AT THE NY TERMINALS AS THE RAIN CHANGES OVER TO
SNOW BETWEEN 08Z AND 11Z. AT KAVP WITH ALMOST ALL RAIN
EXPECTED...MVFR CIGS AND VSBYS ARE MORE LIKELY. TOWARD 1330Z
HOWEVER A BRIEF CHANGEOVER TO SNOW MAY PRODUCE SOME QUICK IFR
VSBYS.
LATER TODAY GRADUAL IMPROVEMENT TO MVFR BY LATE MORNING AND VFR
THIS AFTERNOON.
.OUTLOOK...
FRIDAY NIGHT/SAT...POSSIBLE MVFR IN SNOW SHOWERS...PRIMARILY NYS.
SATURDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MLJ/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...HEDEN
AREA FORECAST DISCUSSION
NWS BINGHAMTON NY
1203 AM EST FRI DEC 23 2011
.SYNOPSIS...
A FAST MOVING LOW PRESSURE SYSTEM WILL MOVE INTO THE MID ATLANTIC
REGION OVERNIGHT THEN OFF THE NEW JERSEY COAST BY MORNING. THIS
SYSTEM WILL SPREAD RAIN OVER THE REGION THIS EVENING WHICH WILL
GRADUALLY CHANGE TO WET SNOW OVERNIGHT. MINOR SNOW ACCUMULATIONS
ARE LIKELY ACROSS CENTRAL NEW YORK, ESPECIALLY IN THE HIGHER
TERRAIN. THE REST OF THE HOLIDAY WEEKEND WILL BE COOLER WITH
TEMPERATURES CLOSER TO NORMAL ALONG WITH DRY CONDITIONS.
&&
.NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
MIDNIGHT UPDATE...WE HAVE MADE SOME TWEEKS TO THE NEAR TERM. SFC
TEMPS WERE RUNNING A BIT ON THE COOL SIDE AND HAVE RAISED THEM A
FEW DEG OVER THE NXT 3-6 HRS. AS FOR PCPN...WE ARE LEANING TWDS
THE RUC AND OUR LCL WRF WHICH INDICATES A SLIGHTLY LATER CHGOVR
AND THEREFORE LESSER SNOW ACCUMS. DOUBT WE`LL SEE MUCH SNOW S OF
THE NY/PA BORDER...WITH BEST CHC N OF THE NY/PA BORDER ACRS THE
HIER ELEVATIONS OF THE CNTRL SRN TIER/SUSQ RGN WHERE AN INCH IS
PSBL...AND MAYBE 2 0R 3 INCHES OVER ERN DELAWARE COUNTY. PREV BLO...
10 PM UPDATE... PCPN HAS NOW ENVELOPED ALL BUT OUR FAR SERN
ZNS...AND IT SHOULD DEVELOP THERE AS WELL BY ARND 05Z. SAT IMAGERY
SHOWS A WELL DEVELOPED UPR-LVL WV APPROACHING FROM THE SW (AS
EVIDENCED BY NICE BAROCLINIC LEAF SIG)...WITH IMPROVING UPR-LVL
JET DYNAMICS. BEST/STEADIEST PCPN WILL OCCUR BETWEEN NOW AND ABT
10-12Z...WITH A FAIRLY RAPID DEPARTURE FROM SW TO NE THEREAFTER.
SFC TEMPS ARE WELL ABV FRZG ATTM ALL THE WAY BACK TO SRN
ONT...LENDING CREDENCE TO OUR FCST OF ONLY A GRADUAL CHG OVER TO
SNOW DURG THE NGT. WE`LL RIDE WITH OUR CURRENT FCST OF GENERALLY
1-3" OF SNOW (MOSTLY HIGHER ELEVS) ACRS MUCH OF CNY AND PA`S NRN
BORDER CNTYS...WITH LITTLE OR NOTHING DOWN TWDS THE WYO/LACK VLYS.
745 PM UPDATE... STEADIER PCPN IS SLOWLY OVERSPREADING THE AREA
FROM SW TO NE ATTM. THE INITIAL STRIPE OF PCPN SHOULD IMPACT OUR
NRN ZNS (FINGER LAKES RGN)...AS BETTER FGEN FORCING WILL RESIDE
HERE PRIOR TO 06Z. THEREAFTER...PCPN SHOULD RAPIDLY DEVELOP ACRS THE
ENTIRE FA...AS MOIST ADVECTION/UPPER JET DYNAMICS MAXIMIZE IN THE
06-12Z TIME FRAME.
IT CERTAINLY APPEARS THAT BLYR TEMPS WILL DICTATE PTYPE
OVERNIGHT...AS NO WARM LYR SEEMS EVIDENT ON MODEL SNDGS. GIVEN
MILD SFC TEMPS OUT THERE EARLY THIS EVE...IT SHOULD TAKE QUITE A
WHILE FOR SNOW TO MIX IN...SPCLY IN THE VLYS. WE`RE STILL GOING
FOR A CHANGE OVER TO SNOW FROM NW TO SE AFTER 06Z...MAINLY ON THE
HILLTOPS...REACHING THE TWIN TIERS IN THE 09-12Z TIME PD. THE
WYO/LACK VLYS LOOK TO STAY PRIMARILY RAIN FOR THE ENTIRE EVENT.
PREV DISC... A FAIRLY STRONG FAST MOVING WAVE WILL LIFT NORTHEAST
INTO THE MID ATLANTIC REGION BY MIDNIGHT THEN OFF THE NEW JERSEY
COAST BY 12Z FRIDAY. THIS SYSTEM WILL QUICKLY SPREAD LIGHT RAIN
OVER THE REGION THIS EVENING. PRECIP TYPE WITH THIS SYSTEM WILL BE
DETERMINED BY BOUNDARY LAYER TEMPS. MODEL SOUNDINGS AND T925 PROGS
INDICATE PRECIP WILL FALL JUST AS RAIN THROUGH 06Z THEN GRADUALLY
CHANGE TO WET SNOW ACROSS CENTRAL NEW YORK AS COLD AIR BUILDS IN
BEHIND WAVE. SNOW ACCUMS WILL BE HIGHLY ELEVATION DEPENDENT WITH
THE HIGHER ELEVATIONS ACROSS CNTRL NY POSSIBLY GETTING 1 TO 2
INCHES. IN OTSEGO/DELAWARE COUNTIES ACCUMS NEAR 3 INCHES ARE
POSSIBLE. FURTHER SOUTH IN THE WYOMING VALLEY, PIKE AND SULLIVAN
COUNTIES CONDITIONS WILL REMAIN TOO WARM FOR ANY ACCUMS.
LOWS BY DAYBREAK WILL FALL INTO LOWER TO MIDDLE 30S BY READINGS
AROUND 40 IN THE WYOMING VALLEY.
&&
.SHORT TERM /6 AM FRIDAY MORNING THROUGH SUNDAY/...
FRIDAY...SFC WAVE WILL LIFT NORTHEAST QUICKLY WITH ANY REMAINING
ACTIVITY PULLING OUT OF THE EASTERN CWA BY 15Z. BEHIND SYSTEM A
NORTHWEST FLOW OF COLDER AIR WILL DEVELOP WITH HIGHER POPS
ADVERTISED DOWNWIND OF LAKE ONTARIO DUE TO POSSIBLE LES SNOW
SHOWERS. MAX TEMPS WILL RANGE FROM THE MID 30 TO AROUND 40.
FRIDAY NIGHT...SFC HIGH PRES NOSES DOWN FROM EASTERN CANADA WITH
SKIES BECOMING PARTLY CLOUDY. T85 DROPS ENOUGH FOR LES BUT WEAK
FLOW AND FAIRLY DRY AIRMASS WILL LIMIT ANY ACTIVITY. WILL JUST
CONTINUE WITH CHC/SLIGHT CHC POPS IN WESTERLY FLOW. LOWS WILL
RANGE FROM THE UPPER TEENS TO MID 20S.
SATURDAY THROUGH CHRISTMAS...A FAIRLY DRY PERIOD WITH NEAR
SEASONAL TEMPS. A WEAK WARM FRONT TO OUR WEST ON SATURDAY WILL
BRING MORE CLOUDS ACROSS THE AREA BUT ANY PRECIP WILL STAY WELL
WEST/NORTH OF REGION. MAX TEMPS SATURDAY WILL RANGE IN THE 30S.
SATURDAY NIGHT INTO CHRISTMAS, SFC HIGH PRES ALONG THE ATLANTIC
COAST WILL PROVIDE A SLIGHT TEMP MODERATION UNDER SOUTHWEST FLOW.
LATE CHRISTMAS DAY AN APPROACHING TROF WILL BRING A CHANCE FOR
RAIN/SNOW SHOWERS TOWARD EVENING ESPECIALLY IN THE WESTERN FA. MAX
TEMPS ON CHRISTMAS WILL RANGE IN THE MID 30S TO AROUND 40.
&&
.LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/...
MODELS IN SOMEWHAT DECENT AGREEMENT FOR THE EXTENDED FORECAST.
THERE WILL BE AN UPPER LEVEL TROUGH AND A SFC LOW MOVING ACROSS
THE NORTHEASTERN US SUNDAY NIGHT. THIS WILL BRING A CHANCE OF SNOW
TO THE AREA. THIS SYSTEM QUICKLY CLEARS OUT AND HIGH PRESSURE
BUILDS IN FOR TUESDAY. BY TUESDAY NIGHT, A LOW PASSES TO THE NORTH
OF THE CWA AND LOOKS TO JUST BRING SOME CLOUDS TO THE AREA ATTM.
THEN, ANOTHER RIDGE OF HIGH PRESSURE SETS UP FOR WEDNESDAY THROUGH
THURSDAY MORNING. FOR WEDNESDAY NIGHT AND THURSDAY, MODELS DO
DIVERGE SOMEWHAT, WITH THE ECMWF HOLDING ONTO THE HIGH PRESSURE
LONGER THEN THE GFS, WHICH HAS A LOW APPROACHING THE CWA FROM THE
WEST. EITHER WAY, MOST OF THE WEEK LOOKS PRETTY QUIET WEATHER WISE
WITH TEMPS LIKELY ABOVE NORMAL.
&&
.AVIATION /06Z FRIDAY THROUGH TUESDAY/...
8 PM UPDATE... MVFR CIGS XPCTD THROUGH 03-04Z...EXCEPT FOR
KAVP...WHERE VFR SHOULD HANG ON A BIT LONGER. THEREAFTER...PCPN
WILL DEVELOP AREA-WIDE...WITH LWR MVFR/IFR RESTRICTIONS
ANTICIPATED OVERNIGHT INTO EARLY FRI.
IMPROVEMENT BACK TO VFR IS FCST BY FRI AFTN...WITH LWR LVL DRY AIR
COMING IN FROM THE W BY THIS TIME.
VRBL SFC WINDS ARND 5 KT OVERNIGHT...WILL TURN NW ON FRI AND
INCREASE TO ARND 10 KT.
.OUTLOOK...
FRIDAY NIGHT/SAT...POSSIBLE MVFR IN SNOW SHOWERS...PRIMARILY NYS.
SATURDAY NIGHT THROUGH TUESDAY...PRIMARILY VFR.
&&
.BGM WATCHES/WARNINGS/ADVISORIES...
PA...NONE.
NY...NONE.
&&
$$
SYNOPSIS...RRM
NEAR TERM...MLJ/RRM
SHORT TERM...RRM
LONG TERM...SLI
AVIATION...MLJ/SLI
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
630 AM EST FRI DEC 23 2011
.SYNOPSIS...
A COLD FRONT WILL MOVE ACROSS THE AREA THIS MORNING. HIGH PRESSURE
WILL BUILD IN LATER TODAY AND PREVAIL THROUGH SUNDAY MORNING. A
QUICK MOVING SYSTEM WILL BRING A CHANCE OF RAIN LATE CHRISTMAS
DAY...WITH ANOTHER POTENTIAL RAIN-MAKER TUESDAY. NEXT WEEK WILL
FEATURE SEASONABLE TEMPERATURES.
&&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...MILD WEATHER WILL LAST ONE MORE DAY BEFORE
COOLER AND MORE SEASONABLE AIR MOVES IN BEHIND AN EASTWARD-MOVING
COLD FRONT. THIS FRONT IS CURRENTLY LOCATED ACROSS THE CENTRAL
CAROLINAS INTO EASTERN GEORGIA...AND SHOULD MOVE INTO THE EASTERN
CAROLINAS LATER THIS MORNING AND OFFSHORE THIS AFTERNOON.
UPSTAIRS...A SHORTWAVE TROUGH WILL LARGELY SHEAR OUT AS IT PUSHES
ACROSS THE MID-ATLANTIC TODAY.
CHANCES FOR SIGNIFICANT RAINFALL EVENT ARE LOOKING PRETTY SLIM AS
MID-LEVEL MOISTURE IS THINNING AS THE FRONT MOVES EAST AND THE UPPER
LEVEL DYNAMICS ARE NOT PARTICULARLY SUPPORTIVE EITHER. RADAR
COMPOSITES LOOK VERY ANEMIC...AND THE HRRR SHOWS ONLY A COUPLE HOUR
LONG WINDOW FOR POTENTIAL REDEVELOPMENT OF SHOWERS ALONG THE
IMMEDIATE COAST LATE THIS MORNING. THE SREF 6-HOUR POP FOR RAINFALL
EQUAL OR GREATER THAN 0.10 INCH IS LESS THAN 10 PERCENT TODAY. THE
DAYTIME "POP" IN OUR FORECAST IS DEFINED AS THE PROBABILITY OF 0.01
INCHES OR MORE OF RAIN FALLING WITHIN THE 12-HOUR PERIOD 7 AM TO 7
PM...SO EVEN 20-30 PERCENT NUMBERS HERE DO NOT NECESSARILY TRANSLATE
TO ANY SIGNIFICANT RAINFALL FROM A HYDROLOGICAL...AGRICULTURAL OR
PUBLIC STANDPOINT.
WITH THE FRONT EXPECTED TO BE TRAVERSING THE AREA DURING THE LATE
MORNING HOURS HIGH TEMPERATURES SHOULD RANGE FROM 69-74 AT THE COAST
TO 67-70 INLAND. DRIER AND COOLER AIR ADVECTING ACROSS THE AREA THIS
EVENING WILL CLEAR THE SKIES AND ALLOW TEMPERATURES TO FALL INTO THE
40-45 RANGE...MUCH CLOSER TO (BUT STILL ABOVE) NORMAL VALUES FOR
THIS TIME OF YEAR.
&&
.SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...MAIN FEATURE WILL BE THE SHEARED SHORTWAVE
MOVING QUICKLY ACROSS THE AREA LATE CHRISTMAS DAY. CONTINUED TO LEAN
TOWARD THE GFS WHICH SHOWS QPF DEVELOPING QUICKLY WEST TO EAST
SUNDAY AFTERNOON AND CONTINUING THROUGH EARLY EVENING QUICKLY COMING
TO AN END BY MONDAY MORNING. THE OMEGA IS PRIMARILY FROM THE RIGHT
ENTRANCE REGION OF A 300MB JET. TOTAL QPF HAS TRENDED LOWER WITH THE
GFS SHOWING AN AXIS OF APPROXIMATELY HALF OF AN INCH ACROSS SOUTHERN
AREAS BY MONDAY MORNING (24 HOUR). THIS IS USUALLY ON THE HIGH SIDE
AND WITH SOME OF THE GENERATED MOISTURE NEEDED TO SATURATE LOWER
LEVELS...WE MAY DO WELL TO SEE ONE THIRD OF AN INCH. OTHERWISE...
SATURDAY LOOKS PARTLY TO MOSTLY SUNNY WITH A COOL START TO CHRISTMAS
DAY. TEMPERATURE GUIDANCE HAS TRENDED LOWER FOR SUNDAY MORNING WITH
GOOD RADIATIONAL CONDITIONS AND I FAVORED THE COOLER MAV NUMBERS FOR
CHRISTMAS DAY.
&&
.LONG TERM /MONDAY THROUGH THURSDAY/...
AS OF 300 AM FRIDAY...FOCUS REMAINS ON THE SOUTHERN STREAM AND A
SYSTEM POSSIBLY MOVING ACROSS TUESDAY INTO WEDNESDAY. THE LATEST GFS
HAS INTRODUCED A NEW IDEA OF KEEPING A PIECE OF ENERGY BEHIND LATE
SUNDAY THAT EVENTUALLY GETS KICKED OUT TUESDAY. THIS HAS TRENDED
TOWARD THE ECMWF SOLUTION. CERTAINLY INTERESTING AND WITH HPC AS
WELL AS ADJACENT OFFICES NOT YET ON BOARD...WILL KEEP FORECAST
BASICALLY DRY WITH THE CAVEAT THAT THE TUESDAY FORECAST COULD CHANGE
CONSIDERABLY. ALL OF THIS SAID...I DID TREND UP POPS SLIGHTLY FOR
TUESDAY TO AT LEAST HINT OF THIS ALTHOUGH THEY GENERALLY REMAIN
BELOW MENTION IN MOST AREAS. SAME GOES FOR DEWPOINTS AND CLOUDCOVER.
NO OTHER CHANGES. DRY WITH TEMPERATURES NEAR CLIMATOLOGY AFTER THIS
EVENT.
&&
.AVIATION /12Z FRIDAY THROUGH TUESDAY/...
AS OF 12Z...CURRENTLY VFR CONDITIONS CONTINUE AT ALL TAF SITES
EXCEPT FOR CEILINGS WHICH ARE FLUCTUATING BETWEEN MVFR AND VFR
CONDITIONS AT KFLO. THE COLD FRONT IS EXPECTED TO PUSH ITS WAY TO
THE COAST THROUGH THE DAY AND IS CURRENTLY PASSING BY KCLT AND
APPROACHING KCAE. FOR TODAY THE CONFIDENCE IS LOW FOR IFR CONDITIONS
AND MVFR CONDITIONS ARE POSSIBLE DUE TO CEILINGS WITH RIBBON OF
MOISTURE ALONG AND AHEAD OF THE FRONT. THE FORECAST INCLUDES
VICINITY OF SHOWERS AHEAD OF THE FRONT BUT CURRENTLY PRECIPITATION
IS NOT EXPECTED TO BE WIDESPREAD...SIGNIFICANT AND AN IMPACT TO
AVIATION.
A WIND SHIFT FROM THE SOUTHWEST TO NORTHWEST IS EXPECTED WITH THE
FRONTS PASSAGE. TIMING OF THE WIND SHIFT IS EXPECTED TO BE AT 15 UTC
AT THE INLAND TAF SITES OF KFLO AND KLBT AND 17 UTC AT THE COASTAL
SITES OF KILM...KCRE AND KMYR.
EXTENDED OUTLOOK...VFR SATURDAY. RAIN AND IFR POSSIBLE SUNDAY AND
MONDAY MORNING. VFR TUESDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 630 AM FRIDAY...SEAS AT THE FRYING PAN SHOALS BUOY HAVE
CLIMBED TO 7 FT THIS MORNING...DUE LARGELY TO AN EXPANSIVE FETCH
OF SOUTH WINDS ALONG THE SOUTHEASTERN U.S. COAST. A DOMINANT WAVE
PERIOD AROUND 7 SECONDS SHOW THE SOURCE REGION FOR THIS WAVE ENERGY
PROBABLY EXISTS BETWEEN NORTH CAROLINA AND GEORGIA/NORTH FLORIDA.
CHANGES ARE ON THE THE WAY HOWEVER AS A COLD FRONT NOW IN THE
CENTRAL CAROLINAS MOVES EAST AND OFF THE COAST THIS AFTERNOON.
SOUTHWEST WINDS WILL SHIFT TO THE NORTH THIS AFTERNOON...THEN TO THE
NORTH-NORTHEAST LATE TONIGHT AS HIGH PRESSURE TO OUR NORTHWEST
BUILDS IN. WE SHOULD GET THROUGH THIS EVENT WITHOUT NEEDING A SMALL
CRAFT ADVISORY...WITH SEAS INSIDE OF 20 MILES REMAINING UNDER 6
FEET. WINDS SHOULD DIMINISH TO 15 KT OR LESS SHORTLY...AND
POST-FRONTAL WINDS SHOULD TOP OUT IN THE 15 KNOT RANGE TONIGHT. WE
WILL MAINTAIN THE EXERCISE CAUTION HEADLINE IN THE FORECAST MAINLY
FOR SEAS THROUGH THIS MORNING ACROSS THE NORTH CAROLINA WATERS.
SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/...
AS OF 300 AM FRIDAY...NORTHEAST FLOW INITIALLY OF 15-20 KNOTS WILL
MOST LIKELY KEEP SEAS IN A 3-5 FOOT RANGE WARRANTING A SCEC
HEADLINE. WINDS DIMINISH SATURDAY NIGHT INTO SUNDAY AS THE
GRADIENT WEAKENS. FINALLY A DECENT NORTHWEST FLOW DEVELOPS EARLY
MONDAY AS HIGH PRESSURE BUILDS BACK IN. HIGHEST SEAS WITH THIS
FETCH WILL DEVELOP ACROSS THE OUTER WATERS.
LONG TERM /MONDAY THROUGH TUESDAY/...
AS OF 300 AM FRIDAY...HIGH PRESSURE MOVES IN FROM THE TENNESSEE
VALLEY MONDAY AND TUESDAY. WINDS WILL VEER FROM NORTHWEST TO
NORTHEAST AND FINALLY LIGHT AND VARIABLE TUESDAY AS THE HIGH MOVES
DIRECTLY OVERHEAD. ALL OF THIS COULD CHANGE DRAMATICALLY HOWEVER AS
FORECAST MODELS REMAIN FAR APART IN THEIR RESPECTIVE SOLUTIONS. IF
THE FORECAST DOES CHANGE...WIND SPEEDS WILL INCREASE SOMEWHAT AS LOW
PRESSURE INCREASES THE GRADIENT WITH THE PREVIOUSLY MENTIONED AREA
OF HIGH PRESSURE. PROBABLY NOT DYNAMIC ENOUGH TO WARRANT A HEADLINE
HOWEVER.
&&
.ILM WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
NC...NONE.
MARINE...NONE.
&&
$$
SYNOPSIS...SHK
NEAR TERM...TRA
SHORT TERM...SHK
LONG TERM...SHK
AVIATION...DRH
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
1133 AM CST FRI DEC 23 2011
.DISCUSSION...SEE AVIATION SECTION BELOW.
&&
.AVIATION...CLOUDS CAN BE SEEN VIA VSBY SATELLITE SPREADING AND
THICKENING ACROSS S TX. AS A RESULT...VFR/MVFR CIGS WILL LOWER
THRU THE AFTERNOON AND INTO TONIGHT. PATCHY DZ IS EXPECTED TO DVLP
OVERNIGHT AS ISENTROPIC UPGLIDE DVLPS...MAINLY ACROSS THE W CWA
THEN SHIFTING E THROUGH THE PERIOD. THIS WILL LEAD TO MVFR CIGS
AND OCCASIONALLY MVFR VSBY`S AS WELL. IFR CONDITIONS WILL BE POSSIBLE
AT TIMES ON SATURDAY AS MOISTURE CONTS TO DEEPEN ACROSS THE AREA.
&&
.PREV DISCUSSION... /ISSUED 906 AM CST FRI DEC 23 2011/
DISCUSSION...CAA CONTS THIS MORNING AND HAS LEAD TO STRONG
OFFSHORE WINDS ACROSS THE COASTAL WATERS. A SCA FOR THE OFFSHORE
WATERS WAS TO GO INTO EFFECT AT NOON BUT HAVE GONE AHEAD AND PUT
THE SCA INTO EFFECT NOW. AS FOR THE REST OF THE FCST...STILL LOOKS
LIKE CLOUDS WILL BE ON THE INCREASE TODAY ALONG WITH A COASTAL
TROF DVLPG THROUGH TONIGHT IN RESPONSE TO AN APPROACHING MID/UPPER
LEVEL LOW. THEREFORE NO OTHER CHANGES TO THE FCST AT THIS TIME.
PREV DISCUSSION... /ISSUED 556 AM CST FRI DEC 23 2011/
DISCUSSION...UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
AVIATION...MIX OF VFR/MVFR THROUGH NEXT 24 HRS. LOW CLOUD DECK
PROG TO DEVELOP/EXPAND THIS MRNG. MVFR CIGS XPCTD TO INCREASE TO
VFR MIDDAY/EARLY AFTN THEN GRADUALLY LOWER THROUGH TONIGHT.
OVERRUNNING WX PATTERN TO DEVELOP TONIGHT THRU SAT WITH DZ/RA
POSSIBLE OVERNIGHT AT KLRD WITH -DZ DVLPING VCNTY KCRP/KALI BY
DAYBREAK. MVFR CIGS TONIGHT ALL TERMINALS MAY BRIEFLY BECOME IFR
AT KLRD. BREEZY NNE WINDS TODAY TO STRENGTHEN LATE TONIGHT AS
COASTAL TROUGH DVLPS.
PREV DISCUSSION... /ISSUED 503 AM CST FRI DEC 23 2011/
SHORT TERM (TODAY THROUGH SATURDAY)...MSAS AND LAPS DATA ALONG
WITH SFC OBS INDICATE COLD FRONT HAS PUSHED SOUTH THROUGH ALL OF
CWA WITH SHALLOW COOL/DRY AIRMASS ADVECTING INTO REGION. RUC DATA
AND WATER VAPOR ANALYSIS SHOWS MID LEVEL LOW DIGGING SOUTH ACROSS SE
AZ AND IS PROG TO EVENTUALLY KICK EAST BY LATE TODAY AND THROUGH
SATURDAY AND WILL IMPACT AREA WEATHER. TODAY TO FEATURE LOW CLOUD
DECK DEVELOPING WHICH WILL HELP SUPPRESS WARMING. HAVE GONE
TOWARDS COOLER GUIDANCE FOR MAX TEMPS THO HOW WARM WE GET WILL
DEPEND ON HOW FAST LOW CLOUDS FILL IN. WAA AT H85 TO DEVELOP
TONIGHT AND WITH INCREASE OF MOISTURE INFLUX IN LOWEST HUNDRED MB
AS COASTAL TROUGH DEVELOPS PATCHY -RA/DZ IS EXPECTED TO DEVELOP
ALONG RIO GRANDE THIS EVENING WITH AN INCREASE IN COVERAGE LIKELY
ACROSS BRUSH COUNTRY AND COASTAL PLAINS BY DAYBREAK SATURDAY. ALL
INDICATIONS ARE THAT MOST AREAS SHOULD SEE RAIN AT SOME POINT ON
SATURDAY AS UPPER LEVEL DISTURBANCE KICKS EAST INTO TX AND COASTAL
TROUGH PERSISTS ALONG MID TX COAST. HIGHEST RAINFALL AMOUNTS MAY
OCCUR ACROSS FAR EASTERN BRUSH COUNTRY...COASTAL PLAINS AND NE
ZONES WHERE BEST MOISTURE TRANSPORT PROG TO OCCUR ALONG WITH
APPROACHING UPPER LEVEL JET STREAK. POCKETS OF LOCALLY HEAVY RAIN
ARE NOT OUT OF THE QUESTION. GUIDANCE DIFFERS ON HOW LONG RAINS
WILL PERSIST WITH HI RES ARW...NMM AND CMC KEEPING EQUAL CHANCES
ACROSS THE AREA THROUGH SAT EVENING WHILE ECMWF AND GFS GRADUALLY
END RAINFALL FROM WEST TO EAST BY LATE IN THE DAY. EXPECTING A
GRADUAL SHIFTING OF BACK EDGE OF RAIN FROM WEST TO EAST BY LATE IN
THE DAY SATURDAY AND INTO THE EVENING. CONCERNING TEMPS
TONIGHT...SOME EVAP COOLING SHOULD OCCUR INTO EARLY SAT MORNING
AND HAVE GONE BELOW GUIDANCE FOR MOST LOCATIONS. THICK CLOUD COVER
AND PRECIP SHOULD RESULT IN LITTLE DIURNAL RANGE IN TEMPS ON SAT
AND HAVE GONE WELL BELOW GUIDANCE FOR HIGHS. AS COASTAL TROUGH
DEVELOPS TONIGHT SFC WINDS WILL INCREASE WITH RAW AND GUSTY NE
WINDS TO BE COMMON ACROSS EASTERN THIRD OF CWA LATE TONIGHT
THROUGH SATURDAY.
LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...ON SATURDAY EVENING
COASTAL SFC TROF WILL START TO TRANSITION SLIGHTLY FURTHER OFF THE
COAST WHILE H8 INVERTED TROF WILL REMAIN SITUATED OVER THE COAST
WITH OVERRUNNING PRECIPITATION STARTS TO PUSH GRADUALLY EASTWARD
AS WELL. THE PRECIPITATION WILL CONTINUE TO TAPER AND MIGRATE
EASTWARD OVER THE MARINE WATERS OVERNIGHT INTO SUNDAY MORNING AS THE
COASTAL TROF CONTINUES TO PUSH INTO THE WESTERN GULF. THE H5 UPPER
TROF WILL PUSH INTO THE ARKLATEX REGION SUNDAY WITH WINDS BACKING TO
A MORE NORTHWEST FLOW AS A SFC HIGH DIVES INTO THE BIG BEND REGION.
AS A RESULT A MUCH DRIER AND COOL AIRMASS WILL REMAIN ENTRENCHED
ACROSS SOUTH TEXAS ON SUNDAY WITH HIGHS REBOUNDING TO THE MID 50S
ACROSS THE REGION. A SECOND UPPER TROF WILL TRACK ACROSS NORTH TEXAS
MONDAY AS SFC HIGH PRESSURE MOVES OVER SOUTH TEXAS. DRY NORTHERLY
FLOW AND SUBSIDENCE WILL PREVAIL MONDAY WITH TEMPERATURES WARMING
SLIGHTLY WITH HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE COAST.
OVERNIGHT LOWS MONDAY WILL BE IN THE MID 30S ACROSS THE INTERIOR AND
IN THE LWR 40S ALONG THE IMMEDIATE COAST WITH SOME LOCATIONS ACROSS
THE NORTHERN TIER OF THE CWA REMAINING IN THE 30S TUESDAY MORNING.
SPOTTY MIN TEMPERATURES NEAR OR JUST BELOW FREEZING MONDAY AND
TUESDAY MORNING...PARTICULARLY IN THE LOWER TERRAIN OF LASALLE AND
MCMULLEN COUNTIES SUCH AS CROSS AND FOWLERTON. TEMPS WILL SLOWLY
MODIFY EACH DAY THROUGH THE WORK-WEEK AS A RETURN FLOW GETS
ESTABLISHED BY LATE TUESDAY OR EARLY WEDNESDAY AS THE SFC HIGH
SLIDES EASTWARD INTO THE SE UNITED STATES. HIGHS TEMPERATURES BY THE
END OF THE WEEK WILL BE IN THE 70S AREA WIDE.
70/SCC
MARINE...COLD FRONT HAS MOVED SOUTH THROUGH WATERS THIS MORNING.
NORTH WINDS ARE MEETING SCA CRITERIA ACROSS PORTIONS OF
BAYS/WATERWAYS THIS MORNING BUT THIS SHOULD BE SHORT LIVED.
INCREASE IN WINDS AND SEAS TO COME LATE THIS AFTERNOON AND THROUGH
HOLIDAY WEEKEND AS COASTAL TROUGH DEVELOPS. SMALL CRAFT ADVISORIES
IN EFFECT FOR OFFSHORE WATERS STARTING AT NOON AS WINDS INCREASE
TO AROUND 20 KNOTS AND FOR NEAR SHORE WATERS STARTING LATE
TONIGHT. ADVISORIES TO CONTINUE THROUGH SATURDAY AS SEAS BECOME
ROUGH AND WINDS REMAIN STRONG. ADVISORIES ARE LIKELY TO BE
EXPANDED FOR BAYS AND WATERWAYS FOR THIS WEEKEND IN LATER FORECAST
PACKAGES. RAIN POSSIBLY HEAVY AT TIMES LIKELY ON SATURDAY AND INTO
SATURDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 61 49 50 40 56 / 10 40 80 60 10
VICTORIA 58 45 49 38 56 / 10 20 80 70 10
LAREDO 60 45 48 40 57 / 10 60 80 20 10
ALICE 61 47 49 39 56 / 10 50 80 40 10
ROCKPORT 60 49 52 43 57 / 10 30 80 70 10
COTULLA 57 43 47 36 55 / 10 50 80 20 10
KINGSVILLE 61 49 50 40 57 / 10 50 80 50 10
NAVY CORPUS 62 52 54 43 58 / 10 40 80 70 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM CST
SATURDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM
BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM
PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SATURDAY FOR THE FOLLOWING
ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60
NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL
FROM 20 TO 60 NM.
&&
$$
TE/81...SHORT TERM/AVIATION
WC/87...LONG TERM
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
906 AM CST FRI DEC 23 2011
.DISCUSSION...CAA CONTS THIS MORNING AND HAS LEAD TO STRONG
OFFSHORE WINDS ACROSS THE COASTAL WATERS. A SCA FOR THE OFFSHORE
WATERS WAS TO GO INTO EFFECT AT NOON BUT HAVE GONE AHEAD AND PUT
THE SCA INTO EFFECT NOW. AS FOR THE REST OF THE FCST...STILL LOOKS
LIKE CLOUDS WILL BE ON THE INCREASE TODAY ALONG WITH A COASTAL
TROF DVLPG THROUGH TONIGHT IN RESPONSE TO AN APPROACHING MID/UPPER
LEVEL LOW. THEREFORE NO OTHER CHANGES TO THE FCST AT THIS TIME.
&&
.PREV DISCUSSION... /ISSUED 556 AM CST FRI DEC 23 2011/
DISCUSSION...UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
AVIATION...MIX OF VFR/MVFR THROUGH NEXT 24 HRS. LOW CLOUD DECK
PROG TO DEVELOP/EXPAND THIS MRNG. MVFR CIGS XPCTD TO INCREASE TO
VFR MIDDAY/EARLY AFTN THEN GRADUALLY LOWER THROUGH TONIGHT.
OVERRUNNING WX PATTERN TO DEVELOP TONIGHT THRU SAT WITH DZ/RA
POSSIBLE OVERNIGHT AT KLRD WITH -DZ DVLPING VCNTY KCRP/KALI BY
DAYBREAK. MVFR CIGS TONIGHT ALL TERMINALS MAY BRIEFLY BECOME IFR
AT KLRD. BREEZY NNE WINDS TODAY TO STRENGTHEN LATE TONIGHT AS
COASTAL TROUGH DVLPS.
PREV DISCUSSION... /ISSUED 503 AM CST FRI DEC 23 2011/
SHORT TERM (TODAY THROUGH SATURDAY)...MSAS AND LAPS DATA ALONG
WITH SFC OBS INDICATE COLD FRONT HAS PUSHED SOUTH THROUGH ALL OF
CWA WITH SHALLOW COOL/DRY AIRMASS ADVECTING INTO REGION. RUC DATA
AND WATER VAPOR ANALYSIS SHOWS MID LEVEL LOW DIGGING SOUTH ACROSS SE
AZ AND IS PROG TO EVENTUALLY KICK EAST BY LATE TODAY AND THROUGH
SATURDAY AND WILL IMPACT AREA WEATHER. TODAY TO FEATURE LOW CLOUD
DECK DEVELOPING WHICH WILL HELP SUPPRESS WARMING. HAVE GONE
TOWARDS COOLER GUIDANCE FOR MAX TEMPS THO HOW WARM WE GET WILL
DEPEND ON HOW FAST LOW CLOUDS FILL IN. WAA AT H85 TO DEVELOP
TONIGHT AND WITH INCREASE OF MOISTURE INFLUX IN LOWEST HUNDRED MB
AS COASTAL TROUGH DEVELOPS PATCHY -RA/DZ IS EXPECTED TO DEVELOP
ALONG RIO GRANDE THIS EVENING WITH AN INCREASE IN COVERAGE LIKELY
ACROSS BRUSH COUNTRY AND COASTAL PLAINS BY DAYBREAK SATURDAY. ALL
INDICATIONS ARE THAT MOST AREAS SHOULD SEE RAIN AT SOME POINT ON
SATURDAY AS UPPER LEVEL DISTURBANCE KICKS EAST INTO TX AND COASTAL
TROUGH PERSISTS ALONG MID TX COAST. HIGHEST RAINFALL AMOUNTS MAY
OCCUR ACROSS FAR EASTERN BRUSH COUNTRY...COASTAL PLAINS AND NE
ZONES WHERE BEST MOISTURE TRANSPORT PROG TO OCCUR ALONG WITH
APPROACHING UPPER LEVEL JET STREAK. POCKETS OF LOCALLY HEAVY RAIN
ARE NOT OUT OF THE QUESTION. GUIDANCE DIFFERS ON HOW LONG RAINS
WILL PERSIST WITH HI RES ARW...NMM AND CMC KEEPING EQUAL CHANCES
ACROSS THE AREA THROUGH SAT EVENING WHILE ECMWF AND GFS GRADUALLY
END RAINFALL FROM WEST TO EAST BY LATE IN THE DAY. EXPECTING A
GRADUAL SHIFTING OF BACK EDGE OF RAIN FROM WEST TO EAST BY LATE IN
THE DAY SATURDAY AND INTO THE EVENING. CONCERNING TEMPS
TONIGHT...SOME EVAP COOLING SHOULD OCCUR INTO EARLY SAT MORNING
AND HAVE GONE BELOW GUIDANCE FOR MOST LOCATIONS. THICK CLOUD COVER
AND PRECIP SHOULD RESULT IN LITTLE DIURNAL RANGE IN TEMPS ON SAT
AND HAVE GONE WELL BELOW GUIDANCE FOR HIGHS. AS COASTAL TROUGH
DEVELOPS TONIGHT SFC WINDS WILL INCREASE WITH RAW AND GUSTY NE
WINDS TO BE COMMON ACROSS EASTERN THIRD OF CWA LATE TONIGHT
THROUGH SATURDAY.
LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...ON SATURDAY EVENING
COASTAL SFC TROF WILL START TO TRANSITION SLIGHTLY FURTHER OFF THE
COAST WHILE H8 INVERTED TROF WILL REMAIN SITUATED OVER THE COAST
WITH OVERRUNNING PRECIPITATION STARTS TO PUSH GRADUALLY EASTWARD
AS WELL. THE PRECIPITATION WILL CONTINUE TO TAPER AND MIGRATE
EASTWARD OVER THE MARINE WATERS OVERNIGHT INTO SUNDAY MORNING AS THE
COASTAL TROF CONTINUES TO PUSH INTO THE WESTERN GULF. THE H5 UPPER
TROF WILL PUSH INTO THE ARKLATEX REGION SUNDAY WITH WINDS BACKING TO
A MORE NORTHWEST FLOW AS A SFC HIGH DIVES INTO THE BIG BEND REGION.
AS A RESULT A MUCH DRIER AND COOL AIRMASS WILL REMAIN ENTRENCHED
ACROSS SOUTH TEXAS ON SUNDAY WITH HIGHS REBOUNDING TO THE MID 50S
ACROSS THE REGION. A SECOND UPPER TROF WILL TRACK ACROSS NORTH TEXAS
MONDAY AS SFC HIGH PRESSURE MOVES OVER SOUTH TEXAS. DRY NORTHERLY
FLOW AND SUBSIDENCE WILL PREVAIL MONDAY WITH TEMPERATURES WARMING
SLIGHTLY WITH HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE COAST.
OVERNIGHT LOWS MONDAY WILL BE IN THE MID 30S ACROSS THE INTERIOR AND
IN THE LWR 40S ALONG THE IMMEDIATE COAST WITH SOME LOCATIONS ACROSS
THE NORTHERN TIER OF THE CWA REMAINING IN THE 30S TUESDAY MORNING.
SPOTTY MIN TEMPERATURES NEAR OR JUST BELOW FREEZING MONDAY AND
TUESDAY MORNING...PARTICULARLY IN THE LOWER TERRAIN OF LASALLE AND
MCMULLEN COUNTIES SUCH AS CROSS AND FOWLERTON. TEMPS WILL SLOWLY
MODIFY EACH DAY THROUGH THE WORK-WEEK AS A RETURN FLOW GETS
ESTABLISHED BY LATE TUESDAY OR EARLY WEDNESDAY AS THE SFC HIGH
SLIDES EASTWARD INTO THE SE UNITED STATES. HIGHS TEMPERATURES BY THE
END OF THE WEEK WILL BE IN THE 70S AREA WIDE.
70/SCC
MARINE...COLD FRONT HAS MOVED SOUTH THROUGH WATERS THIS MORNING.
NORTH WINDS ARE MEETING SCA CRITERIA ACROSS PORTIONS OF
BAYS/WATERWAYS THIS MORNING BUT THIS SHOULD BE SHORT LIVED.
INCREASE IN WINDS AND SEAS TO COME LATE THIS AFTERNOON AND THROUGH
HOLIDAY WEEKEND AS COASTAL TROUGH DEVELOPS. SMALL CRAFT ADVISORIES
IN EFFECT FOR OFFSHORE WATERS STARTING AT NOON AS WINDS INCREASE
TO AROUND 20 KNOTS AND FOR NEAR SHORE WATERS STARTING LATE
TONIGHT. ADVISORIES TO CONTINUE THROUGH SATURDAY AS SEAS BECOME
ROUGH AND WINDS REMAIN STRONG. ADVISORIES ARE LIKELY TO BE
EXPANDED FOR BAYS AND WATERWAYS FOR THIS WEEKEND IN LATER FORECAST
PACKAGES. RAIN POSSIBLY HEAVY AT TIMES LIKELY ON SATURDAY AND INTO
SATURDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 61 49 50 40 56 / 10 40 80 60 10
VICTORIA 58 45 49 38 56 / 10 20 80 70 10
LAREDO 60 45 48 40 57 / 10 60 80 20 10
ALICE 61 47 49 39 56 / 10 50 80 40 10
ROCKPORT 60 49 52 43 57 / 10 30 80 70 10
COTULLA 57 43 47 36 55 / 10 50 80 20 10
KINGSVILLE 61 49 50 40 57 / 10 50 80 50 10
NAVY CORPUS 62 52 54 43 58 / 10 40 80 70 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM CST
SATURDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM
BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM
PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY UNTIL 6 PM CST SATURDAY FOR THE FOLLOWING
ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS FROM 20 TO 60
NM...WATERS FROM PORT ARANSAS TO MATAGORDA SHIP CHANNEL
FROM 20 TO 60 NM.
&&
$$
TE/81...SHORT TERM
WC/87...LONG TERM
AREA FORECAST DISCUSSION...UPDATED
NWS CORPUS CHRISTI TX
556 AM CST FRI DEC 23 2011
.DISCUSSION...UPDATED FOR 12Z AVIATION DISCUSSION BELOW.
&&
.AVIATION...MIX OF VFR/MVFR THROUGH NEXT 24 HRS. LOW CLOUD DECK
PROG TO DEVELOP/EXPAND THIS MRNG. MVFR CIGS XPCTD TO INCREASE TO
VFR MIDDAY/EARLY AFTN THEN GRADUALLY LOWER THROUGH TONIGHT.
OVERRUNNING WX PATTERN TO DEVELOP TONIGHT THRU SAT WITH DZ/RA
POSSIBLE OVERNIGHT AT KLRD WITH -DZ DVLPING VCNTY KCRP/KALI BY
DAYBREAK. MVFR CIGS TONIGHT ALL TERMINALS MAY BRIEFLY BECOME IFR
AT KLRD. BREEZY NNE WINDS TODAY TO STRENGTHEN LATE TONIGHT AS
COASTAL TROUGH DVLPS.
&&
.PREV DISCUSSION... /ISSUED 503 AM CST FRI DEC 23 2011/
SHORT TERM (TODAY THROUGH SATURDAY)...MSAS AND LAPS DATA ALONG
WITH SFC OBS INDICATE COLD FRONT HAS PUSHED SOUTH THROUGH ALL OF
CWA WITH SHALLOW COOL/DRY AIRMASS ADVECTING INTO REGION. RUC DATA
AND WATER VAPOR ANALYSIS SHOWS MID LEVEL LOW DIGGING SOUTH ACROSS SE
AZ AND IS PROG TO EVENTUALLY KICK EAST BY LATE TODAY AND THROUGH
SATURDAY AND WILL IMPACT AREA WEATHER. TODAY TO FEATURE LOW CLOUD
DECK DEVELOPING WHICH WILL HELP SUPPRESS WARMING. HAVE GONE
TOWARDS COOLER GUIDANCE FOR MAX TEMPS THO HOW WARM WE GET WILL
DEPEND ON HOW FAST LOW CLOUDS FILL IN. WAA AT H85 TO DEVELOP
TONIGHT AND WITH INCREASE OF MOISTURE INFLUX IN LOWEST HUNDRED MB
AS COASTAL TROUGH DEVELOPS PATCHY -RA/DZ IS EXPECTED TO DEVELOP
ALONG RIO GRANDE THIS EVENING WITH AN INCREASE IN COVERAGE LIKELY
ACROSS BRUSH COUNTRY AND COASTAL PLAINS BY DAYBREAK SATURDAY. ALL
INDICATIONS ARE THAT MOST AREAS SHOULD SEE RAIN AT SOME POINT ON
SATURDAY AS UPPER LEVEL DISTURBANCE KICKS EAST INTO TX AND COASTAL
TROUGH PERSISTS ALONG MID TX COAST. HIGHEST RAINFALL AMOUNTS MAY
OCCUR ACROSS FAR EASTERN BRUSH COUNTRY...COASTAL PLAINS AND NE
ZONES WHERE BEST MOISTURE TRANSPORT PROG TO OCCUR ALONG WITH
APPROACHING UPPER LEVEL JET STREAK. POCKETS OF LOCALLY HEAVY RAIN
ARE NOT OUT OF THE QUESTION. GUIDANCE DIFFERS ON HOW LONG RAINS
WILL PERSIST WITH HI RES ARW...NMM AND CMC KEEPING EQUAL CHANCES
ACROSS THE AREA THROUGH SAT EVENING WHILE ECMWF AND GFS GRADUALLY
END RAINFALL FROM WEST TO EAST BY LATE IN THE DAY. EXPECTING A
GRADUAL SHIFTING OF BACK EDGE OF RAIN FROM WEST TO EAST BY LATE IN
THE DAY SATURDAY AND INTO THE EVENING. CONCERNING TEMPS
TONIGHT...SOME EVAP COOLING SHOULD OCCUR INTO EARLY SAT MORNING
AND HAVE GONE BELOW GUIDANCE FOR MOST LOCATIONS. THICK CLOUD COVER
AND PRECIP SHOULD RESULT IN LITTLE DIURNAL RANGE IN TEMPS ON SAT
AND HAVE GONE WELL BELOW GUIDANCE FOR HIGHS. AS COASTAL TROUGH
DEVELOPS TONIGHT SFC WINDS WILL INCREASE WITH RAW AND GUSTY NE
WINDS TO BE COMMON ACROSS EASTERN THIRD OF CWA LATE TONIGHT
THROUGH SATURDAY.
LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...ON SATURDAY EVENING
COASTAL SFC TROF WILL START TO TRANSITION SLIGHTLY FURTHER OFF THE
COAST WHILE H8 INVERTED TROF WILL REMAIN SITUATED OVER THE COAST
WITH OVERRUNNING PRECIPITATION STARTS TO PUSH GRADUALLY EASTWARD
AS WELL. THE PRECIPITATION WILL CONTINUE TO TAPER AND MIGRATE
EASTWARD OVER THE MARINE WATERS OVERNIGHT INTO SUNDAY MORNING AS THE
COASTAL TROF CONTINUES TO PUSH INTO THE WESTERN GULF. THE H5 UPPER
TROF WILL PUSH INTO THE ARKLATEX REGION SUNDAY WITH WINDS BACKING TO
A MORE NORTHWEST FLOW AS A SFC HIGH DIVES INTO THE BIG BEND REGION.
AS A RESULT A MUCH DRIER AND COOL AIRMASS WILL REMAIN ENTRENCHED
ACROSS SOUTH TEXAS ON SUNDAY WITH HIGHS REBOUNDING TO THE MID 50S
ACROSS THE REGION. A SECOND UPPER TROF WILL TRACK ACROSS NORTH TEXAS
MONDAY AS SFC HIGH PRESSURE MOVES OVER SOUTH TEXAS. DRY NORTHERLY
FLOW AND SUBSIDENCE WILL PREVAIL MONDAY WITH TEMPERATURES WARMING
SLIGHTLY WITH HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE COAST.
OVERNIGHT LOWS MONDAY WILL BE IN THE MID 30S ACROSS THE INTERIOR AND
IN THE LWR 40S ALONG THE IMMEDIATE COAST WITH SOME LOCATIONS ACROSS
THE NORTHERN TIER OF THE CWA REMAINING IN THE 30S TUESDAY MORNING.
SPOTTY MIN TEMPERATURES NEAR OR JUST BELOW FREEZING MONDAY AND
TUESDAY MORNING...PARTICULARLY IN THE LOWER TERRAIN OF LASALLE AND
MCMULLEN COUNTIES SUCH AS CROSS AND FOWLERTON. TEMPS WILL SLOWLY
MODIFY EACH DAY THROUGH THE WORK-WEEK AS A RETURN FLOW GETS
ESTABLISHED BY LATE TUESDAY OR EARLY WEDNESDAY AS THE SFC HIGH
SLIDES EASTWARD INTO THE SE UNITED STATES. HIGHS TEMPERATURES BY THE
END OF THE WEEK WILL BE IN THE 70S AREA WIDE.
70/SCC
MARINE...COLD FRONT HAS MOVED SOUTH THROUGH WATERS THIS MORNING.
NORTH WINDS ARE MEETING SCA CRITERIA ACROSS PORTIONS OF
BAYS/WATERWAYS THIS MORNING BUT THIS SHOULD BE SHORT LIVED.
INCREASE IN WINDS AND SEAS TO COME LATE THIS AFTERNOON AND THROUGH
HOLIDAY WEEKEND AS COASTAL TROUGH DEVELOPS. SMALL CRAFT ADVISORIES
IN EFFECT FOR OFFSHORE WATERS STARTING AT NOON AS WINDS INCREASE
TO AROUND 20 KNOTS AND FOR NEAR SHORE WATERS STARTING LATE
TONIGHT. ADVISORIES TO CONTINUE THROUGH SATURDAY AS SEAS BECOME
ROUGH AND WINDS REMAIN STRONG. ADVISORIES ARE LIKELY TO BE
EXPANDED FOR BAYS AND WATERWAYS FOR THIS WEEKEND IN LATER FORECAST
PACKAGES. RAIN POSSIBLY HEAVY AT TIMES LIKELY ON SATURDAY AND INTO
SATURDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 61 49 50 40 56 / 10 40 80 60 10
VICTORIA 58 45 49 38 56 / 10 20 80 70 10
LAREDO 60 45 48 40 57 / 10 60 80 20 10
ALICE 61 47 49 39 56 / 10 50 80 40 10
ROCKPORT 60 49 52 43 57 / 10 30 80 70 10
COTULLA 57 43 47 36 55 / 10 50 80 20 10
KINGSVILLE 61 49 50 40 57 / 10 50 80 50 10
NAVY CORPUS 62 52 54 43 58 / 10 40 80 70 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM CST
SATURDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM
BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM
PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 PM CST SATURDAY FOR
THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
AVIATION...HART/79
AREA FORECAST DISCUSSION
NWS CORPUS CHRISTI TX
503 AM CST FRI DEC 23 2011
.SHORT TERM (TODAY THROUGH SATURDAY)...MSAS AND LAPS DATA ALONG
WITH SFC OBS INDICATE COLD FRONT HAS PUSHED SOUTH THROUGH ALL OF
CWA WITH SHALLOW COOL/DRY AIRMASS ADVECTING INTO REGION. RUC DATA
AND WATER VAPOR ANALYSIS SHOWS MID LEVEL LOW DIGGING SOUTH ACROSS SE
AZ AND IS PROG TO EVENTUALLY KICK EAST BY LATE TODAY AND THROUGH
SATURDAY AND WILL IMPACT AREA WEATHER. TODAY TO FEATURE LOW CLOUD
DECK DEVELOPING WHICH WILL HELP SUPPRESS WARMING. HAVE GONE
TOWARDS COOLER GUIDANCE FOR MAX TEMPS THO HOW WARM WE GET WILL
DEPEND ON HOW FAST LOW CLOUDS FILL IN. WAA AT H85 TO DEVELOP
TONIGHT AND WITH INCREASE OF MOISTURE INFLUX IN LOWEST HUNDRED MB
AS COASTAL TROUGH DEVELOPS PATCHY -RA/DZ IS EXPECTED TO DEVELOP
ALONG RIO GRANDE THIS EVENING WITH AN INCREASE IN COVERAGE LIKELY
ACROSS BRUSH COUNTRY AND COASTAL PLAINS BY DAYBREAK SATURDAY. ALL
INDICATIONS ARE THAT MOST AREAS SHOULD SEE RAIN AT SOME POINT ON
SATURDAY AS UPPER LEVEL DISTURBANCE KICKS EAST INTO TX AND COASTAL
TROUGH PERSISTS ALONG MID TX COAST. HIGHEST RAINFALL AMOUNTS MAY
OCCUR ACROSS FAR EASTERN BRUSH COUNTRY...COASTAL PLAINS AND NE
ZONES WHERE BEST MOISTURE TRANSPORT PROG TO OCCUR ALONG WITH
APPROACHING UPPER LEVEL JET STREAK. POCKETS OF LOCALLY HEAVY RAIN
ARE NOT OUT OF THE QUESTION. GUIDANCE DIFFERS ON HOW LONG RAINS
WILL PERSIST WITH HI RES ARW...NMM AND CMC KEEPING EQUAL CHANCES
ACROSS THE AREA THROUGH SAT EVENING WHILE ECMWF AND GFS GRADUALLY
END RAINFALL FROM WEST TO EAST BY LATE IN THE DAY. EXPECTING A
GRADUAL SHIFTING OF BACK EDGE OF RAIN FROM WEST TO EAST BY LATE IN
THE DAY SATURDAY AND INTO THE EVENING. CONCERNING TEMPS
TONIGHT...SOME EVAP COOLING SHOULD OCCUR INTO EARLY SAT MORNING
AND HAVE GONE BELOW GUIDANCE FOR MOST LOCATIONS. THICK CLOUD COVER
AND PRECIP SHOULD RESULT IN LITTLE DIURNAL RANGE IN TEMPS ON SAT
AND HAVE GONE WELL BELOW GUIDANCE FOR HIGHS. AS COASTAL TROUGH
DEVELOPS TONIGHT SFC WINDS WILL INCREASE WITH RAW AND GUSTY NE
WINDS TO BE COMMON ACROSS EASTERN THIRD OF CWA LATE TONIGHT
THROUGH SATURDAY.
&&
.LONG TERM (SATURDAY NIGHT THROUGH THURSDAY)...ON SATURDAY EVENING
COASTAL SFC TROF WILL START TO TRANSITION SLIGHTLY FURTHER OFF THE
COAST WHILE H8 INVERTED TROF WILL REMAIN SITUATED OVER THE COAST
WITH OVERRUNNING PRECIPITATION STARTS TO PUSH GRADUALLY EASTWARD
AS WELL. THE PRECIPITATION WILL CONTINUE TO TAPER AND MIGRATE
EASTWARD OVER THE MARINE WATERS OVERNIGHT INTO SUNDAY MORNING AS THE
COASTAL TROF CONTINUES TO PUSH INTO THE WESTERN GULF. THE H5 UPPER
TROF WILL PUSH INTO THE ARKLATEX REGION SUNDAY WITH WINDS BACKING TO
A MORE NORTHWEST FLOW AS A SFC HIGH DIVES INTO THE BIG BEND REGION.
AS A RESULT A MUCH DRIER AND COOL AIRMASS WILL REMAIN ENTRENCHED
ACROSS SOUTH TEXAS ON SUNDAY WITH HIGHS REBOUNDING TO THE MID 50S
ACROSS THE REGION. A SECOND UPPER TROF WILL TRACK ACROSS NORTH TEXAS
MONDAY AS SFC HIGH PRESSURE MOVES OVER SOUTH TEXAS. DRY NORTHERLY
FLOW AND SUBSIDENCE WILL PREVAIL MONDAY WITH TEMPERATURES WARMING
SLIGHTLY WITH HIGHS IN THE UPPER 50S TO NEAR 60 ALONG THE COAST.
OVERNIGHT LOWS MONDAY WILL BE IN THE MID 30S ACROSS THE INTERIOR AND
IN THE LWR 40S ALONG THE IMMEDIATE COAST WITH SOME LOCATIONS ACROSS
THE NORTHERN TIER OF THE CWA REMAINING IN THE 30S TUESDAY MORNING.
SPOTTY MIN TEMPERATURES NEAR OR JUST BELOW FREEZING MONDAY AND
TUESDAY MORNING...PARTICULARLY IN THE LOWER TERRAIN OF LASALLE AND
MCMULLEN COUNTIES SUCH AS CROSS AND FOWLERTON. TEMPS WILL SLOWLY
MODIFY EACH DAY THROUGH THE WORK-WEEK AS A RETURN FLOW GETS
ESTABLISHED BY LATE TUESDAY OR EARLY WEDNESDAY AS THE SFC HIGH
SLIDES EASTWARD INTO THE SE UNITED STATES. HIGHS TEMPERATURES BY THE
END OF THE WEEK WILL BE IN THE 70S AREA WIDE.
70/SCC
&&
.MARINE...COLD FRONT HAS MOVED SOUTH THROUGH WATERS THIS MORNING.
NORTH WINDS ARE MEETING SCA CRITERIA ACROSS PORTIONS OF
BAYS/WATERWAYS THIS MORNING BUT THIS SHOULD BE SHORT LIVED.
INCREASE IN WINDS AND SEAS TO COME LATE THIS AFTERNOON AND THROUGH
HOLIDAY WEEKEND AS COASTAL TROUGH DEVELOPS. SMALL CRAFT ADVISORIES
IN EFFECT FOR OFFSHORE WATERS STARTING AT NOON AS WINDS INCREASE
TO AROUND 20 KNOTS AND FOR NEAR SHORE WATERS STARTING LATE
TONIGHT. ADVISORIES TO CONTINUE THROUGH SATURDAY AS SEAS BECOME
ROUGH AND WINDS REMAIN STRONG. ADVISORIES ARE LIKELY TO BE
EXPANDED FOR BAYS AND WATERWAYS FOR THIS WEEKEND IN LATER FORECAST
PACKAGES. RAIN POSSIBLY HEAVY AT TIMES LIKELY ON SATURDAY AND INTO
SATURDAY NIGHT.
&&
.PRELIMINARY POINT TEMPS/POPS...
CORPUS CHRISTI 61 49 50 40 56 / 10 40 80 60 10
VICTORIA 58 45 49 38 56 / 10 20 80 70 10
LAREDO 60 45 48 40 57 / 10 60 80 20 10
ALICE 61 47 49 39 56 / 10 50 80 40 10
ROCKPORT 60 49 52 43 57 / 10 30 80 70 10
COTULLA 57 43 47 36 55 / 10 50 80 20 10
KINGSVILLE 61 49 50 40 57 / 10 50 80 50 10
NAVY CORPUS 62 52 54 43 58 / 10 40 80 70 10
&&
.CRP WATCHES/WARNINGS/ADVISORIES...
TX...NONE.
GM...SMALL CRAFT ADVISORY FROM 10 PM THIS EVENING TO 6 PM CST
SATURDAY FOR THE FOLLOWING ZONES: COASTAL WATERS FROM
BAFFIN BAY TO PORT ARANSAS OUT 20 NM...COASTAL WATERS FROM
PORT ARANSAS TO MATAGORDA SHIP CHANNEL OUT 20 NM.
SMALL CRAFT ADVISORY FROM NOON TODAY TO 6 PM CST SATURDAY FOR
THE FOLLOWING ZONES: WATERS FROM BAFFIN BAY TO PORT ARANSAS
FROM 20 TO 60 NM...WATERS FROM PORT ARANSAS TO MATAGORDA
SHIP CHANNEL FROM 20 TO 60 NM.
&&
$$
RH/79...SHORT TERM
SC/70...LONG TERM
FOR FREQUENTLY ASKED QUESTIONS ABOUT THE AREA FORECAST DISCUSSION VISIT...
HTTP://WEATHER.GOV/SALTLAKECITY/GENERAL/AFD_FAQS.PHP (ALL LOWER CASE)
AREA FORECAST DISCUSSION
NWS SPOKANE WA
1003 PM PST Thu Dec 22 2011
.SYNOPSIS...High pressure will flatten and shift east tonight and
Friday as a storm moves into the Pacific Northwest. Some mountains
snow is possible. Stronger storms will be possible through the
holiday weekend and into early next week. Those with travel
interests this weekend can expect snow to develop over the mountain
passes, especially near the Cascades and at times, over the Idaho
Panhandle.
&&
.DISCUSSION...
Update tonight is to lower temperatures further. High clouds are
moving in from the west, but they have been slow to get to extreme
eastern WA and northern ID. Temperatures have dropped quite a bit
where fog and stratus haven`t developed. Looking at the cameras
from across the area, the most widespread fog appears to be in the
Spokane area, especially along I-90 in the valley and Liberty Lake and
along the Spokane River. But once you get east to Post Falls or
north toward Chewelah or Colville, it is all stratus. So, have a
NOWCAST out for the locally dense fog in the Spokane area. Models
are suggesting the fog breaking up and dissipating quite early
tomorrow...around 8am. NAM does suggest the boundary layer
becoming less moist with time overnight and into Friday morning.
Even the HRRR suggests the fog dissipating early.
&&
.AVIATION...
06Z TAFs: The lower level air mass beneath an inversion will remain
very moist tonight in the KGEG vcnty. This will result in low clouds
and fog expanding and impacting KEAT, KMWH, KGEG, KSFF, and KCOE.
The greatest duration of fog and stratus will occur at KGEG and KSFF
where the lower levels remain near saturation. Drying in the
boundary layer is expected by 16z Friday as winds shift to the south
with stratus expected to clear of the TAF sites but likely remain in
place over the northern valleys.
&&
.PRELIMINARY POINT TEMPS/POPS...
Spokane 13 28 23 33 24 34 / 0 10 10 30 10 40
Coeur d`Alene 9 31 23 34 25 36 / 0 10 10 30 10 40
Pullman 17 33 27 37 28 40 / 0 10 10 20 0 20
Lewiston 15 35 28 40 29 45 / 0 10 0 10 0 10
Colville 15 30 23 35 23 35 / 0 10 20 40 20 50
Sandpoint 11 30 21 34 23 35 / 0 10 20 50 20 40
Kellogg 16 30 23 35 27 36 / 0 10 10 20 10 30
Moses Lake 7 30 21 34 21 37 / 0 10 10 20 0 20
Wenatchee 12 33 26 35 24 37 / 0 10 10 20 10 30
Omak 9 29 22 35 21 33 / 0 10 10 30 10 40
&&
.OTX WATCHES/WARNINGS/ADVISORIES...
ID...None.
WA...None.
&&
$$
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
540 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...TONIGHT AND SUNDAY
540 PM CST SAT DEC 24 2011
MAIN AVIATION CONCERN IS THE WINDS. A FAIRLY TIGHT PRESSURE
GRADIENT OVER THE TAF SITES...BETWEEN LOW PRESSURE IN NORTHWEST
ONTARIO AND HIGH PRESSURE OVER THE CENTRAL PLAINS...WILL REMAIN
IN PLACE THROUGH SUNDAY. NIGHT TIME COOLING SHOULD PREVENT GUSTS
TONIGHT...THOUGH A 10-15 KT SUSTAINED WIND VEERING FROM SOUTHWEST
TO WEST IS ANTICIPATED. ONCE DAYTIME MIXING STARTS ON SUNDAY...
WITHIN A FEW HOURS GUSTS TO 20-25 KT SHOULD DEVELOP...ALONG WITH
WINDS VEERING TO NORTHWESTERLY. A SURFACE RIDGE AXIS IS FORECAST
TO CROSS THE TAF SITES SUNDAY EVENING WHICH WILL HELP DIMINISH THE
WINDS THEN. OTHERWISE...EXPECT VFR CONDITIONS TO CONTINUE THROUGH
SUNDAY WITH PLENTIFUL LOW TO MID LEVEL DRY AIR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
247 PM CST SAT DEC 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS GOODLAND KS
232 AM MST SUN DEC 25 2011
.SYNOPSIS...
IR SATELLITE IMAGERY SHOWED CLEAR SKIES OVER THE CENTRAL PLAINS.
LATEST RUC UPPER AIR ANALYSIS SHOWED THE WESTERN HALF OF THE CONUS
UNDER AN UPPER LEVEL RIDGE...AND A CLOSED LOW REMAINING NEARLY
STATIONARY OVER WESTERN TEXAS AND EASTERN NEW MEXICO. AT THE
SURFACE...HIGH PRESSURE WAS MAKING ITS WAY INTO THE TRI-STATE
AREA.
JTL
&&
.SHORT TERM (TODAY-TUESDAY)...
223 AM MST SUN DEC 25 2011
MAIN ISSUE WITH THE FORECAST WILL BE TEMPERATURES. FOR MOST OF THE
AREA TEMPERATURES WILL CONTINUE TO BE NEAR OR ABOVE NORMAL THROUGH
THE PERIOD. OVER THE AREAS THAT HAVE EXCESSIVE SNOW COVER
TEMPERATURES WILL BE 5 TO 10 DEGREES COOLER.
UPPER LEVEL AND SURFACE HIGH PRESSURE WILL REMAIN OVER THE TRI-STATE
AREA TODAY THROUGH EARLY MONDAY WITH THE UPPER LEVEL CLOSED LOW
WOBBLING OVER THE TEXAS PANHANDLE. WINDS WILL BE LIGHT AS A SURFACE
HIGH PRESSURE MOVES ACROSS THE AREA TODAY.
MONDAY A SHORT WAVE TROUGH MOVES THROUGH THE UPPER LEVEL FLOW
PUSHING THE CLOSED LOW EAST. AT THE SURFACE A PRE-FRONTAL TROUGH WILL
ACCOMPANY THE UPPER LEVEL FEATURE. WITH A STRONGER PRESSURE
GRADIENT IN PLACE AS THE TROUGH MOVES THROUGH...WINDS WILL
STRENGTHEN AHEAD AND ESPECIALLY BEHIND THE TROUGH. WINDS WILL
BECOME GUSTY AS STRONGER WINDS ABOVE THE SURFACE ARE ABLE TO MIX
DOWN TO THE GROUND. COOLER AIR WILL MOVE IN BEHIND THE TROUGH.
WINDS WILL WEAKEN OVERNIGHT AS HIGH PRESSURE BUILDS IN BEHIND THE
TROUGH.
TUESDAY A SHORT WAVE TROUGH WILL MOVE THROUGH THE UPPER LEVEL FLOW
OVER THE AREA DURING THE EVENING. UPPER LEVEL MOISTURE INCREASES AND THERE
IS SOME LIFTING ASSOCIATED WITH THE TROUGH PASSAGE. HOWEVER A DRY
LAYER REMAINS BETWEEN THE MOISTURE AND THE SURFACE WHICH WILL LIKELY
EVAPORATE ANY PRECIPITATION THAT MAY FORM.
JTL
.LONG TERM (WEDNESDAY-SATURDAY)...
223 AM MST SUN DEC 25 2011
A WEAK UPPER LEVEL DISTURBANCE MOVES OUT OF THE NORTHERN ROCKIES ON
THURSDAY. BEST LIFT AND MOISTURE WILL BE FAR TO THE NORTH OF THE
LOCAL AREA. OTHERWISE...A DRY WESTERLY FLOW WILL DOMINATE WITH NO
PRECIPITATION CHANCES AND TEMPERATURES ABOVE NORMAL. /024
&&
.AVIATION...
935 PM MST SAT DEC 24 2011
VFR CONDITIONS EXPECTED THE NEXT 24 HOURS. HIGH PRESSURE WILL
DOMINATE THE WEATHER PATTERN AND SLIDE FROM THE ROCKIES INTO THE
CENTRAL PLAINS. THIS WILL CAUSE WINDS TO SHIFT FROM THE NORTHWEST
TO SOUTHWEST BY THE END OF THE PERIOD.
BAS
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GRAY ME
1202 AM EST SUN DEC 25 2011
.SYNOPSIS...
HIGH PRESSURE WILL CREST OVER THE REGION TONIGHT AND SHIFT OFFSHORE.
A WEAK WARM FRONT WILL APPROACH FROM THE SOUTHWEST ON SUNDAY AHEAD
OF LOW PRESSURE MOVING OUT OF THE GREAT LAKES. LOW PRESSURE WILL
CROSS THE AREA SUNDAY NIGHT DRAGGING A COLD FRONT THROUGH THE AREA.
HIGH PRESSURE WILL BUILD INTO THE AREA ON MONDAY AND WILL SHIFT
OFFSHORE MONDAY NIGHT. A COLD FRONT WILL MOVE TOWARD THE REGION FROM
THE NORTHWEST ON TUESDAY AND WILL STALL OVER NEW ENGLAND TUESDAY
NIGHT AS LOW PRESSURE MOVES UP THE EAST COAST. LOW PRESSURE WILL
TRACK SOUTH OF NEW ENGLAND AND INTO THE MARITIMES ON WEDNESDAY. HIGH
PRESSURE WILL BUILD OVER THE AREA WEDNESDAY NIGHT AND THURSDAY.
&&
.NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
1159 PM...MINOR ADJUSTMENTS TO CLOUD COVER FOR OCEAN EFFECT CLOUDS
AND SNOW SHOWERS PRESENTLY ACROSS SOUTHEAST NEW HAMPSHIRE AND
PARTS OF SOUTHERN YORK COUNTY. OTHERWISE...MINOR ADJUSTMENTS TO
1ST PERIOD GRIDS. I ADJUSTED WINDS UP ON THE WATERS OVERNIGHT IN
NE FLOW.
PREV DISC...
UPDATE...OCEAN EFFECT CLOUDS ARE DEVELOPING OFF THE SEACOAST
ATTM...WITH CLOUD TOPS COOLING QUICKLY OVER THE LAST HR. WEAK
ECHOES ALSO BECOMING EVIDENT ON BOTH THE KGYX AND KBOX 88D. HAVE
MOVED POP SLIGHTLY TO ACCOUNT FOR THESE TRENDS...BUT FCST REMAINS
ON TRACK FOR TNGT.
PREVIOUS DISCUSSION...ALSO WATCHING THE POTENTIAL FOR OCEAN
EFFECT SHSN TO DEVELOP FOR THE SEACOAST AROUND MIDNIGHT. SSTS
AROUND +8C WITH H85 TEMPS RUNNING AROUND -13C ARE PROVIDING FOR
SOME PRETTY GOOD DELTA T VALUES. AS WINDS VEER LATE THIS
EVE...ONSHORE FLOW WILL DEVELOP FOR THE SEACOAST...AND WOULD NOT
BE SURPRISED TO SEE SHSN MOVE ONSHORE AS WELL. 12Z GFS HAD LATCHED
ONTO THIS IDEA...AND WHILE THE NAM HAD NO QPF FOR THE AREA WEAK
OMEGA WAS INDICATED AT THE BOTTOM OF THE SATURATED SNOW GROWTH
ZONE IN BUFKIT PROFILES. HRRR SUPPORTS A FEW HRS OF SHSN AS
WELL...WITH A DUSTING TO A HALF INCH ACCUM PSBL. HAVE UPPED POP TO
CHC CENTERED ON THE BEST PARAMETERS AND TRENDED EITHER SIDE FROM
THERE. FLOW BECOME DISORGANIZED VERY EARLY SUN...BEFORE ONSHORE
FLOW BECOMES ENHANCED ALONG MIDCOAST.
STRONG SURFACE HIGH PRESSURE WILL CREST OVER THE REGION
TONIGHT...THEN MOVE OFFSHORE LATE. INITIAL CLEAR CALM CONDITIONS
WITH SNOW COVER IN MOST AREAS WILL ALLOW TEMPERATURES TO FALL VERY
QUICKLY. INCREASING CIRRUS LATER ON WILL PROBABLY SLOW DOWN THE
TEMP DROPS...BUT PROBABLY NOT BEFORE GUIDANCE MINS ARE MET. EXPECT
THE GOOD RADIATORS TO DROP TO AROUND ZERO...AND THE BEST RADIATORS
DROP BELOW.
&&
.SHORT TERM /6 AM SUNDAY MORNING THROUGH 6 PM SUNDAY/...
A WAA REGIME WILL GET GOING SUNDAY MORNING AS HIGH PRESSURE MOVES
OFFSHORE AND A SHORT WAVE TROUGH APPROACHES FROM THE WEST. MAY
ACTUALLY SEE SOME LIGHT OCEAN EFFECT SNOWS ON THE MID COAST BY
LATE MORNING.
DURING THE AFTERNOON...LARGE SCALE FORCING FOR ASCENT WILL
COMMENCE AS THE COLUMN MOISTENS UP. THIS SHOULD ALLOW FOR SOME
LIGHT SNOW TO DEVELOP ACROSS A GOOD PORTION OF THE AREA. ACCUMS
WON/T BE MUCH...PROBABLY A DUSTING TO AN INCH DURING THE
DAY...PERHAPS A TOUCH MORE IN LINCOLN...KNOX...AND WALDO COUNTIES
IN MAINE DUE TO OCEAN ENHANCEMENT. I SUPPOSE THE NH COAST AND THE
REST OF THE MAINE COAST COULD SEE SOME OF THIS TOO WHILE THE WINDS
ARE E/SE...BUT LESS CONFIDENCE THERE. SOMETHING TO WATCH LATE
TONIGHT AND EARLY TOMORROW MORNING THOUGH.
THE STRONG SHORT WAVE TROUGH WILL BE KNOCKING ON OUR DOOR SUNDAY
EVENING...AND WILL MOVE OVERHEAD OVERNIGHT. STABILITY DECREASES AS
THIS HAPPENS...AS TOTAL TOTAL INDICES RISE WELL INTO THE 50S. AS
THIS HAPPENS...WE EXPECT AT LEAST SCATTERED SNOW
SQUALLS TO DEVELOP...ESPECIALLY AS WE MOVE TOWARD LATE EVENING
AND MIDNIGHT. THESE SQUALLS COULD PUT DOWN A QUICK INCH OR TWO AND
CAUSE LOCALLY HAZARDOUS DRIVING CONDITIONS.
&&
.LONG TERM /SUNDAY NIGHT THROUGH SATURDAY/...
HIGH PRESSURE WILL GRADUALLY BUILD OVER THE REGION ON MONDAY AS LOW
PRESSURE PULLS AWAY TO THE EAST. EXPECT MOSTLY CLOUDY SKIES MONDAY
MORNING TO GIVE WAY TO SUNSHINE IN THE AFTERNOON WITH VARIABLE
CLOUDS LINGERING IN THE MOUNTAINS. LOOKING FOR HIGHS FROM THE MID
20S NORTH TO THE MID 30S SOUTH.
HIGH PRESSURE WILL SHIFT OFFSHORE MONDAY EVENING WITH RETURN FLOW
PUMPING WARMER AIR BACK INTO THE REGION OVERNIGHT. WARM FRONT
CROSSING SOUTHERN CANADA WILL BRING VARIABLE HIGH CLOUDS OVERNIGHT
BUT EXPECT ANY SNOW SHOWER ACTIVITY GENERALLY REMAIN NORTH OF THE
FORECAST AREA.
A COLD FRONT APPROACHING FROM THE NORTHWEST WILL BRING INCREASING
CLOUDS AND A CHANCE OF RAIN OR SNOW SHOWERS TO THE REGION ON
TUESDAY. SHORTWAVE LIFTING NORTHEAST OUT OF THE OHIO VALLEY WILL
TRACK NORTHEAST ALONG THIS BOUNDARY AS IT STALLS OVER NEW ENGLAND
TUESDAY NIGHT. GFS NOW IN WITH A MUCH COLDER SOLUTION WITH LOW
PRESSURE SOUTH OF NEW ENGLAND TUESDAY NIGHT...MOVING INTO THE
MARITIMES ON WEDNESDAY. WILL LIKELY SEE SOME ADJUSTMENTS TO TIMING
AND TRACK THROUGH THE WEEKEND SO NOT JUMPING ON THE LATEST GUIDANCE
AT THIS POINT...BUT DOES APPEAR LIKELY WE`LL SEE SOME SIGNIFICANT
PRECIPITATION TUESDAY NIGHT AND WEDNESDAY.
LOW PRESSURE FORECAST TO SHIFT INTO THE MARITIMES WEDNESDAY NIGHT AS
HIGH PRESSURE BUILDS IN FROM THE WEST. WILL SEE PRECIPITATION ENDING
AND CLEARING SKIES WEDNESDAY AFTERNOON...SETTING UP A CLEAR AND
CHILLY NIGHT.
HIGH PRESSURE WILL HOLD OVER THE REGION ON THURSDAY WITH MOSTLY
SUNNY SKIES AND LIGHT WINDS ALONG WITH SEASONABLE TEMPS.
NEXT SHORTWAVE APPROACHES FROM THE WEST ON FRIDAY BRINGING
INCREASING CLOUDS AND A CHANCE OF SNOW FOR SOUTHERN AREAS. LOW
PRESSURE WILL FADE OVER THE GREAT LAKES AS A SECONDARY AREA OF LOW
PRESSURE DEVELOPS SOUTH OF NEW ENGLAND AND LIFTS NORTHEAST. AT THIS
POINT LOOKS LIKE THE BULK OF THE QPF FALLS OUT ACROSS SOUTHERN NEW
ENGLAND AND OFFSHORE...BUT PLENTY OF TIME FOR CHANGES.
&&
.AVIATION /06Z SUNDAY THROUGH THURSDAY/...
SHORT TERM...VFR TONIGHT THROUGH MUCH OF SUNDAY MORNING. LOCALLY
LOWER CONDITIONS MAY DEVELOP ON THE COAST DURING THE MORNING DUE
TO SNOW SHOWERS. SNOW SQUALLS MAY BRIEFLY REDUCE VSBYS TO BELOW
1/2 MILE SUNDAY EVENING.
LONG TERM...VFR MONDAY THROUGH TUESDAY. IFR/LIFR VSBY AND CEILINGS
DEVELOPING TUESDAY NIGHT...IMPROVING WEDNESDAY AFTERNOON. VFR
WEDNESDAY NIGHT AND THURSDAY.
&&
.MARINE...
SHORT TERM...WINDS AND SEAS CONTINUE TO DIMINISH THIS EVENING WITH
HIGH PRESSURE BUILDING OVERHEAD. SWLY FLOW DEVELOPS SUNDAY
AFTERNOON AND EVENING...AND WILL LIKELY GUST TO AROUND 30 KT WITH
BUILDING SEAS. THEREFORE...A SCA HAS BEEN ISSUED TO COVER THIS.
LONG TERM...SCA WINDS LIKELY MONDAY...DIMINISHING IN THE
AFTERNOON. GALES POSSIBLE LATE TUESDAY NIGHT INTO WEDNESDAY.
&&
.GYX WATCHES/WARNINGS/ADVISORIES...
ME...NONE.
NH...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 2 PM SUNDAY TO 5 AM EST MONDAY FOR
ANZ150>154.
&&
$$
ES
AREA FORECAST DISCUSSION
NWS LA CROSSE WI
1058 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 06Z MONDAY
1058 PM CST SAT DEC 24 2011
MAIN AVIATION CONCERN IS THE WINDS. A FAIRLY TIGHT PRESSURE
GRADIENT OVER THE TAF SITES...BETWEEN LOW PRESSURE IN NORTHWEST
ONTARIO AND HIGH PRESSURE OVER THE CENTRAL PLAINS...WILL REMAIN
IN PLACE TODAY. LOOK FOR SUSTAINED WINDS OF 10 TO 15 KT TO PERSIST
THROUGH THE DAY. HOWEVER...ONCE DAYTIME MIXING STARTS...WITHIN A
FEW HOURS GUSTS TO 20-25 KT SHOULD DEVELOP...ALONG WITH WINDS
VEERING TO NORTHWESTERLY. A SURFACE RIDGE AXIS IS FORECAST TO
CROSS THE TAF SITES SUNDAY EVENING...HELPING TO END THE GUSTS AND
DIMINISH THE WINDS BELOW 10 KT. OTHERWISE...EXPECT VFR CONDITIONS
TO CONTINUE THROUGH SUNDAY NIGHT WITH PLENTIFUL LOW TO MID LEVEL
DRY AIR.
&&
.ARX WATCHES/WARNINGS/ADVISORIES...
247 PM CST SAT DEC 24 2011
WI...NONE.
MN...NONE.
IA...NONE.
&&
$$
SHORT TERM...HALBACH
LONG TERM...HALBACH
AVIATION...AJ
AREA FORECAST DISCUSSION
NWS COLUMBIA SC
905 AM EST SUN DEC 25 2011
.SYNOPSIS...
HIGH PRESSURE WILL CONTINUE TO MOVE OFFSHORE THIS MORNING AS A
WEAK AREA OF LOW PRESSURE DEVELOPS OVER THE WESTERN GULF STATES
AND TRACKS EASTWARD. CLOUDS WILL THICKEN OVER THE AREA TODAY. SOME
LIGHT RAIN MAY FALL OVER THE AREA LATER THIS AFTERNOON AND
EVENING...PARTICULARLY OVER THE SOUTHERN HALF OF THE FORECAST AREA.
HIGH PRESSURE TO THE NORTH WILL BUILD DOWN SUNDAY NIGHT AND
MONDAY BRINGING DRIER AIR TO THE REGION.
&&
.NEAR TERM /THROUGH TONIGHT/...
HAVE TWEAKED THE POPS OVER THE REGION BASED UPON CURRENT RADAR
TRENDS AND RUC FORECASTS. IN GENERAL POPS ARE INCREASED OVER THE
SOUTHERN HALF OF THE CWA AND TEMPS WILL BE DECREASED SOME BASED
UPON CLOUD COVER AND ANY EVAPORATIVE COOLING.
MODELS SHOW SOME WEAK ISENTROPIC LIFT AS MAIN FORCING FOR CLOUDS
AND PRECIP. PRECIPITATION AMOUNTS WILL BE LOW...GENERALLY AROUND
ONE TENTH OF AN INCH OR LESS...MAYBE SLIGHTLY HIGHER ACROSS THE
CSRA. BY TONIGHT...SYSTEM WILL MOVE EAST OF THE AREA AS S/W ENERGY
SWINGS SE ACROSS THE GREAT LAKES/NEW ENGLAND AND MOISTURE MOVES
OFF THE COAST.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
MODELS HAVE CONTINUED TO COME INTO BETTER AGREEMENT WITH SYSTEM
THAT WILL BE AFFECTING THE AREA MONDAY NIGHT INTO TUESDAY.
HOWEVER...SOME SLIGHT TIMING DIFFERENCES STILL REMAIN AS MODELS
HAVING A HARD TIME WITH CLOSED LOW EJECTING FROM WEST TX/SOUTHERN
PLAINS REGION ON MONDAY INTO TUESDAY. AT THE SURFACE...A SYSTEM WILL
DEVELOP IN THE GULF ON MONDAY AND STRENGTHEN AS IT TRACKS
NORTHEAST...REMAINING WEST OF THE AREA...TUESDAY. ALL OF THE
MODELS AND ENSEMBLES SHOW INCREASING CHANCES FOR RAIN BY MONDAY
NIGHT INTO TUESDAY NIGHT. AS MENTIONED EARLIER...TIMING
DIFFERENCES CONTINUE WITH MODELS. WILL BEGIN INCREASING POPS
MONDAY NIGHT AND PEAK POPS OUT BY TUESDAY AFTERNOON AS THE
ASSOCIATED COLD FRONT BEGINS TO APPROACH THE CWA. AIRMASS AHEAD OF
THE SYSTEM BECOMES WEAKLY/MODERATELY UNSTABLE WITH A STRONG 50 TO
60 KT JET AROUND 5K FT. WILL BE CROSSING THE REGION. HAVE DECIDED
TO MENTION THE POSSIBILITY OF A FEW ISOLATED THUNDERSTORMS TUESDAY
AFTERNOON/EVENING IN ADVANCE OF THE COLD FRONT. SLOWLY IMPROVING
CONDITIONS OVERNIGHT ON TUESDAY. TEMPERATURES WILL REMAIN SLIGHTLY
ABOVE NORMAL THROUGH THE PERIOD.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
DURING THE EXTENDED PERIOD...THE FLOW ACROSS THE LOWER 48 WILL
BECOME MORE ZONAL...ALTHOUGH A COUPLE OF WEAK UPPER TROUGHS
APPROACH LATE IN THE PERIOD. IT LOOKS LIKE THE STORM TRACK REMAINS
TO THE NORTH. HIGHS START IN THE MID TO UPPER 50S TUESDAY AND
WEDNESDAY BUT ARE A BIT WARMER IN THE UPPER 50S TO LOWER 60S LATER
IN THE PERIOD...MAINLY FRIDAY AND SATURDAY. LOW TEMPERATURES
GENERALLY IN THE MID TO UPPER 30S.
&&
.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
WEAK LOW PRESSURE DEVELOPING IN THE WESTERN GULF OF MEXICO WITH
WEAKENING RIDGE ACROSS SOUTH CAROLINA/GEORGIA. RADAR AT 11Z SHOWING
LIGHT RAIN ACROSS MISSISSIPPI AND ALABAMA SPREADING EAST. LATEST
GUIDANCE INDICATING LOW TO MID LEVEL MOISTURE WILL ADVECT INTO THE
REGION LATER THIS MORNING AND WITH MODEST ISENTROPIC LIFT THIS
AFTERNOON EXPECT SOME AREAS OF LIGHT RAIN. LAMP AND MOS GUIDANCE
POPS HAVE INCREASED AND CONFIDENCE NOW HIGH FOR MVFR CONDITIONS IN
THE AGS/DNL AREAS WHERE MOISTURE DEEPEST/STRONGER LIFT AND
CONVERGENCE LOCATED. LIGHT PRECIPITATION AT TIMES THIS AFTERNOON
ACROSS ALL TERMINALS. AREA OF RAIN WILL MOVE EAST OF THE AREA AFTER
00Z WITH AIR MASS DRYING OUT.
EXTENDED AVIATION OUTLOOK...CEILING/VISIBILITY RESTRICTIONS
EXPECTED MONDAY NIGHT INTO TUESDAY AS LOW PRESSURE CROSSES THE
REGION.
&&
.CAE WATCHES/WARNINGS/ADVISORIES...
SC...NONE.
GA...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS GOODLAND KS
420 AM MST SUN DEC 25 2011
.SYNOPSIS...
IR SATELLITE IMAGERY SHOWED CLEAR SKIES OVER THE CENTRAL PLAINS.
LATEST RUC UPPER AIR ANALYSIS SHOWED THE WESTERN HALF OF THE CONUS
UNDER AN UPPER LEVEL RIDGE...AND A CLOSED LOW REMAINING NEARLY
STATIONARY OVER WESTERN TEXAS AND EASTERN NEW MEXICO. AT THE
SURFACE...HIGH PRESSURE WAS MAKING ITS WAY INTO THE TRI-STATE
AREA.
JTL
&&
.SHORT TERM (TODAY-TUESDAY)...
223 AM MST SUN DEC 25 2011
MAIN ISSUE WITH THE FORECAST WILL BE TEMPERATURES. FOR MOST OF THE
AREA TEMPERATURES WILL CONTINUE TO BE NEAR OR ABOVE NORMAL THROUGH
THE PERIOD. OVER THE AREAS THAT HAVE EXCESSIVE SNOW COVER
TEMPERATURES WILL BE 5 TO 10 DEGREES COOLER.
UPPER LEVEL AND SURFACE HIGH PRESSURE WILL REMAIN OVER THE TRI-STATE
AREA TODAY THROUGH EARLY MONDAY WITH THE UPPER LEVEL CLOSED LOW
WOBBLING OVER THE TEXAS PANHANDLE. WINDS WILL BE LIGHT AS A SURFACE
HIGH PRESSURE MOVES ACROSS THE AREA TODAY.
MONDAY A SHORT WAVE TROUGH MOVES THROUGH THE UPPER LEVEL FLOW
PUSHING THE CLOSED LOW EAST. AT THE SURFACE A PRE-FRONTAL TROUGH WILL
ACCOMPANY THE UPPER LEVEL FEATURE. WITH A STRONGER PRESSURE
GRADIENT IN PLACE AS THE TROUGH MOVES THROUGH...WINDS WILL
STRENGTHEN AHEAD AND ESPECIALLY BEHIND THE TROUGH. WINDS WILL
BECOME GUSTY AS STRONGER WINDS ABOVE THE SURFACE ARE ABLE TO MIX
DOWN TO THE GROUND. COOLER AIR WILL MOVE IN BEHIND THE TROUGH.
WINDS WILL WEAKEN OVERNIGHT AS HIGH PRESSURE BUILDS IN BEHIND THE
TROUGH.
TUESDAY A SHORT WAVE TROUGH WILL MOVE THROUGH THE UPPER LEVEL FLOW
OVER THE AREA DURING THE EVENING. UPPER LEVEL MOISTURE INCREASES AND THERE
IS SOME LIFTING ASSOCIATED WITH THE TROUGH PASSAGE. HOWEVER A DRY
LAYER REMAINS BETWEEN THE MOISTURE AND THE SURFACE WHICH WILL LIKELY
EVAPORATE ANY PRECIPITATION THAT MAY FORM.
JTL
.LONG TERM (WEDNESDAY-SATURDAY)...
223 AM MST SUN DEC 25 2011
A WEAK UPPER LEVEL DISTURBANCE MOVES OUT OF THE NORTHERN ROCKIES ON
THURSDAY. BEST LIFT AND MOISTURE WILL BE FAR TO THE NORTH OF THE
LOCAL AREA. OTHERWISE...A DRY WESTERLY FLOW WILL DOMINATE WITH NO
PRECIPITATION CHANCES AND TEMPERATURES ABOVE NORMAL. /024
&&
.AVIATION...
420 AM MST SUN DEC 25 2011
VFR CONDITIONS EXPECTED THE NEXT 24 HOURS. HIGH PRESSURE WILL
DOMINATE THE WEATHER PATTERN AND SLIDE FROM THE ROCKIES INTO THE
CENTRAL PLAINS. THIS WILL CAUSE WINDS TO SHIFT FROM THE NORTHWEST
TO SOUTHWEST BY THE END OF THE PERIOD.
BAS/024
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1040 AM EST SUN DEC 25 2011
.SYNOPSIS...
IT WILL BE A RATHER WINDY AND MILD CHRISTMAS DAY WITH A MIX OF
CLOUDS AND A LITTLE SUNSHINE FOR MOST OF THE DAY. A COLD FRONT AND
UPPER LEVEL DISTURBANCE WILL CROSS THE REGION LATE THIS AFTERNOON
AND THIS EVENING WITH A ROUND OF LIGHT SNOW SHOWERS FOR MUCH OF THE
REGION BRIEFLY BEGINNING AS RAIN. ACCUMULATIONS WILL BE VERY LIMITED
EXCEPT ACROSS THE HIGHER TERRAIN OF THE WESTERN SOUTHERN TIER AND
TUG HILL REGION WHERE SEVERAL INCHES OF SNOW IS POSSIBLE. ANY
LINGERING SNOW SHOWERS WILL QUICKLY END MONDAY AS HIGH PRESSURE
BUILDS INTO THE LOWER LAKES. LOW PRESSURE WILL BRING MORE UNSETTLED
WEATHER TUESDAY WITH SOME LIGHT RAIN ENDING AS A BRIEF PERIOD OF
LIGHT SNOW TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
FOR MOST OF TODAY THE WARM SECTOR WILL BE ESTABLISHED WITH 850MB
TEMPS RISING TO AROUND -1C BY MIDDAY. THE EARLY MORNING CLOUD
COVER SHOULD GIVE WAY TO AT LEAST A FEW BREAKS OF SUNSHINE THROUGH
THE COURSE OF THE DAY. TEMPERATURES WILL ONCE AGAIN RISE ABOVE
AVERAGE WITH THE LAKE PLAINS TOPPING OUT IN THE LOWER 40S...AND
UPPER 30S ACROSS THE HIGHER TERRAIN. IT WILL CONTINUE TO BE
BREEZY...ESPECIALLY ALONG LAKE ERIE AND THE NIAGARA FRONTIER WHERE
GUSTS OF 35 TO 40 MPH ARE EXPECTED THROUGH THIS AFTERNOON.
BY LATE THIS AFTERNOON A STRONG SHORTWAVE WILL BE ON OUR DOORSTEP.
LARGE SCALE FORCING FOR ASCENT WILL QUICKLY INCREASE AFTER 21Z AS
STRONG DPVA AND HEIGHT FALLS OVERSPREAD THE LOWER LAKES. THE NEW
12Z NAM AND HRRR ARE A TAD SLOWER (AN HOUR OR TWO) WITH THE START
OF THE SHOWERS. EXPECT SCATTERED SHOWERS TO DEVELOP AROUND SUNSET
ACROSS WESTERN NY AND THE NORTH COUNTRY THEN QUICKLY SPREAD ACROSS
THE REMAINDER OF THE REGION THROUGH EARLY EVENING. THIS SHOULD
KEEP THE VAST MAJORITY OF THE DAYLIT HOURS DRY ACROSS WESTERN NEW YORK.
NAM/GFS BUFKIT PROFILES SHOW THE BOUNDARY LAYER INITIALLY WARM
ENOUGH FOR MUCH OF THIS TO BE RAIN AT THE START...BUT COLD AIR
ADVECTION AND EVAPORATE COOLING WILL QUICKLY CHANGE THE RAIN
OVER TO SNOW BY MID TO LATE EVENING.
THIS SYSTEM IS FAST MOVING AND RELATIVELY MOISTURE STARVED...SO THIS
WILL GREATLY LIMIT ACCUMULATIONS IN MOST AREAS ESPECIALLY
CONSIDERING THE MILD START AT THE ONSET OF PRECIP. THE MAJORITY OF
THE LOWER ELEVATIONS ACROSS THE REGION WILL SEE LESS THAN AN
INCH...AND PERHAPS NOTHING AT ALL IN SOME AREAS CLOSE TO THE
LAKESHORES. THERE WILL BE TWO NOTABLE EXCEPTIONS TO THIS HOWEVER...
EAST OF LAKE ONTARIO BUFKIT PROFILES AND MESOSCALE MODEL DATA BOTH
SUPPORT A SHORT WINDOW OF SEVERAL HOURS FROM MID TO LATE EVENING
WHERE CONDITIONS BECOME FAVORABLE FOR LAKE ENHANCEMENT NEAR THE TIME
OF THE COLD FRONTAL PASSAGE. NAM BUFKIT PROFILES BRING LAKE INDUCED
EQUILIBRIUM LEVELS ALL THE WAY UP TO 15K FEET FOR A FEW HOURS WITH
WELL ALIGNED WESTERLY FLOW. THIS SHOULD SET THE STAGE FOR LAKE
ENHANCEMENT AT THE EAST END OF THE LAKE...MAXIMIZED ACROSS THE TUG
HILL IN THE FAVORED UPSLOPE AREAS. THE SNOW COULD BECOME QUITE HEAVY
FOR A BRIEF PERIOD OF TIME...BUT THE SHORT DURATION WILL PREVENT ANY
BIG ACCUMULATIONS. HAVE GONE WITH 3-4 INCHES ACROSS THE TUG HILL
REGION FOR TONIGHT. HELD OFF ON ADVISORY FOR NOW GIVEN THE MARGINAL
SNOW NUMBERS AND THE FACT THAT THE GREATER ACCUMULATIONS WILL BE
LIMITED TO A SMALL AREA ACROSS HIGHER TERRAIN...BUT DAY SHIFT MAY
NEED TO CONSIDER A HEADLINE. ACROSS LOWER ELEVATIONS MARGINAL
BOUNDARY LAYER TEMPS WILL GREATLY LIMIT ACCUMULATIONS...ESPECIALLY
CLOSER TO THE LAKE ONTARIO SHORE WHERE VERY LITTLE ACCUMULATION IS
EXPECTED.
AFTER MIDNIGHT THE LAKE ENHANCEMENT WILL EVOLVE INTO PURE LAKE
EFFECT BUT QUICKLY MOVE TO SOUTHEAST OF THE LAKE AS THE BOUNDARY
LAYER FLOW BECOMES NORTHWEST. THIS WILL SET UP RELATIVELY WEAK SNOW
SHOWERS FROM NEAR ROCHESTER OVER TO OSWEGO COUNTY AND DOWN INTO THE
FINGER LAKES. MAY SEE SOME SPOTTY ONE INCH AMOUNTS FROM
THIS...ESPECIALLY FROM THE EASTERN SUBURBS OF ROCHESTER INTO WAYNE
COUNTY. QUICK DRYING OF THE SYNOPTIC BACKGROUND AND VERY MARGINAL
INSTABILITY AFTER MIDNIGHT WILL PREVENT ANYTHING MORE SIGNIFICANT.
THE OTHER AREA OF CONCERN IS ACROSS THE CHAUTAUQUA RIDGE. NAM BUFKIT
PROFILES SUGGEST A WINDOW FROM ABOUT 03Z-09Z WHERE NORTHWEST UPSLOPE
FLOW AND MODEST LAKE ENHANCEMENT WILL BECOME FAVORABLE FOR MINOR
ACCUMULATIONS IN THE TYPICAL AREAS ALONG THE RIDGE LINE FROM SHERMAN
UP THROUGH MAYVILLE TO PERRYSBURG. AGAIN THE QUICK DRYING OUT OF THE
SYNOPTIC MOISTURE AND SHORT FETCH/LIMITED INSTABILITY WILL PREVENT
ANY SIGNIFICANT ACCUMULATIONS...BUT MAY SEE 2-4 INCH AMOUNTS IN SOME
AREAS. MAY ALSO SEE 1-2 INCH AMOUNTS FARTHER NORTH ACROSS THE BOSTON
HILLS AND WYOMING COUNTY...ALTHOUGH THE FLOW QUICKLY ESTABLISHES TOO
MUCH NORTHERLY COMPONENT FOR MUCH LAKE ENHANCEMENT IN THOSE AREAS.
ALL OF THIS SHOULD BE ON THE WANE BEFORE DAYBREAK MONDAY AS A RIDGE
OF HIGH PRESSURE BUILDS TOWARDS LAKE ERIE AND MOISTURE QUICKLY
DECREASES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
FOLLOWING THE PASSAGE OF TODAY`S SYSTEM...STRONG RIDGING WILL BUILD
ACROSS THE AREA AT ALL LEVELS ON MONDAY. ASSOCIATED STRONG DRYING
AND SUBSIDENCE WILL BRING A QUICK END TO ANY LINGERING LAKE EFFECT
SNOW SHOWERS SOUTHEAST OF LAKE ONTARIO IN THE MORNING...ALONG WITH
THE RETURN OF A DECENT AMOUNT OF SUNSHINE. WITH A SEASONABLY COLDER
AIRMASS IN PLACE...DAYTIME TEMPS WILL BE CLOSER TO NORMAL FOR LATE
DECEMBER...OR IN THE LOWER TO MID 30S.
DURING MONDAY NIGHT...THE AFOREMENTIONED RIDGE WILL SLIDE OFF THE
EAST COAST...ALLOWING A PAIR OF SHORTWAVE TROUGHS...ONE IN THE
NORTHERN STREAM AND ONE IN THE SOUTHERN STREAM...TO APPROACH THE
AREA FROM THE NATION`S MIDSECTION. IN ADVANCE OF THESE FEATURES...A
DEEP SOUTHWESTERLY FLOW OF MILDER AIR WILL OVERSPREAD THE AREA...
WITH THE RESULTING WARM AIR ADVECTION LEADING TO BOTH AN INCREASE IN
CLOUD COVER AND A NON-DIURNAL TEMPERATURE TREND...WITH TEMPS
STEADILY RISING AFTER EARLY EVENING LOWS IN THE MID 20S TO LOWER
30S. WITH THE NAM/GFS/GEM AND ECMWF NOW ALL IN GOOD AGREEMENT THAT
ANY PRECIP WILL REMAIN SAFELY WEST OF THE AREA THROUGH THE
NIGHT...HAVE PULLED ANY MENTION OF PRECIP FROM LATE MONDAY NIGHT.
ON TUESDAY...THE AFOREMENTIONED PAIR OF TROUGHS WILL CONTINUE TO
ADVANCE ON THE REGION FROM THE WEST...WITH THE VARIOUS GUIDANCE
PACKAGES CONTINUING TO SHOW DISPARITIES WITH RESPECT TO EXACTLY HOW
MUCH THESE FEATURES PHASE TOGETHER AS THEY APPROACH. AT THIS
TIME...THE SPREAD IN THE GUIDANCE CURRENTLY RANGES FROM THE UNPHASED
00Z NAM/GFS/GEM SOLUTIONS TO THE 00Z ECMWF...WHICH SHOWS THE TWO
WAVES MERGING INTO A RATHER SHARP FULL LATITUDE TROUGH. REGARDLESS
OF WHICH OF THESE SCENARIOS YOU BELIEVE...ALL GENERALLY DEPICT A
DEVELOPING LOW PRESSURE SYSTEM QUICKLY LIFTING NORTHEAST FROM THE
TENNESSEE VALLEY TO THE MID ATLANTIC STATES ON TUESDAY...WITH AN
ASSOCIATED RIBBON OF MOISTURE AND LIFT SPREADING NORTHEAST ACROSS
OUR REGION. THIS SHOULD RESULT IN A LIKELIHOOD OF PRECIP SPREADING
NORTHEAST ACROSS THE REGION DURING THE DAY. AS FOR PTYPE...EXPECTED
MILD BOUNDARY LAYER TEMPS IN THE 40S AND 850 MB TEMPS OF ZERO TO -4C
SHOULD BE SUPPORTIVE OF MAINLY RAIN RIGHT THROUGH THE DAY...WITH
PERHAPS A LITTLE SNOW MIXING IN LATE AS THE COLUMN BEGINS TO COOL A
BIT MORE STRONGLY.
AS THE SURFACE LOW LIFTS FURTHER NORTHEAST ALONG THE NEW ENGLAND
COAST TUESDAY NIGHT...COLD ADVECTION ON ITS BACKSIDE WILL INCREASE.
THIS WILL DELIVER A PROGRESSIVELY COLDER AIRMASS INTO OUR
REGION...RESULTING IN ANY PRECIP CHANGING OVER FROM RAIN TO ALL
SNOW. THE MAIN ISSUE DURING THIS TIME FRAME WILL BE HOW QUICKLY THE
PRECIP TAPERS OFF...WHICH WILL DIRECTLY INFLUENCE POTENTIAL SNOWFALL
ACCUMULATIONS AND WILL BE A DIRECT FUNCTION OF EXACTLY MUCH PHASING
OF THE NORTHERN AND SOUTHERN STREAMS OCCURS. THE FULLY PHASED ECMWF
SOLUTION WOULD SUPPORT A STRONGER AND SLOWER MOVING SURFACE LOW ON A
MORE WESTERLY TRACK...AND WOULD DELIVER COLDER AIR MORE STRONGLY
WHILE ALSO MAINTAINING PRECIP ACROSS THE AREA LONGER...THEREBY
RESULTING IN WHAT WOULD BE A WIDESPREAD ACCUMULATING SNOW. IN
CONTRAST...THE LESS PHASED NAM/GFS/GEM SOLUTIONS OFFER WEAKER
COLD ADVECTION AND A MUCH QUICKER END TO THE SYNOPTIC-SCALE
PRECIP...RESULTING IN MUCH MORE LIMITED ACCUMULATIONS AFTER THE
CHANGEOVER.
WITH HPC PREFERENCES CURRENTLY TOWARD A FASTER...MORE NON-PHASED
SOLUTION LED BY THE CANADIAN GEM...FOR NOW WILL ELECT TO GO WITH A
FASTER END TO THE MAIN SWATH OF SYNOPTIC SCALE PRECIP TUESDAY
NIGHT...WITH LAKE-DRIVEN SNOW SHOWERS TAKING OVER AS A NORTHERLY
FLOW OF PROGRESSIVELY COLDER AIR SPREADS ACROSS THE AREA OVERNIGHT.
THIS SHOULD STILL RESULT IN AT LEAST SOME LIMITED ACCUMULATIONS IN
MANY AREAS BY MORNING...THOUGH THE SHORT NORTHERLY FETCH AND
INCREASINGLY DRY AIRMASS SHOULD KEEP THESE FROM GETTING OUT OF HAND.
WEDNESDAY SHOULD THEN FEATURE A GENERAL REPEAT OF MONDAY...AS THE
COMBINATION OF INCREASING RIDGING/DRYING/SUBSIDENCE HELPS TO SHUT
DOWN ANY LINGERING LAKE EFFECT DURING THE MORNING...AS WELL AS BRING
A RETURN TO AT LEAST SOME PARTIAL SUNSHINE. WITH A MUCH COLDER
AIRMASS IN PLACE /850 TEMPS AVERAGING AROUND -10C/...DAYTIME HIGHS
WILL BE MUCH COLDER THAN TUESDAY`S...WITH READINGS RANGING FROM THE
MID 20S ACROSS THE NORTH COUNTRY TO AROUND 30 ELSEWHERE. CONTINUED
DRY BUT SEASONABLY CHILLY WEATHER WILL THEN FOLLOW FOR WEDNESDAY
NIGHT AS RIDGING CRESTS OVERHEAD AT ALL LEVELS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
IN THE EXTENDED PORTION OF THE FORECAST...SLOWLY DEPARTING SURFACE
RIDGING IS EXPECTED TO KEEP A CONTINUATION OF MAINLY DRY WEATHER
ACROSS OUR REGION THROUGH THURSDAY. THEREAFTER...ONE OR MORE WAVES
OF LOW PRESSURE ZIPPING ALONG IN A PERSISTENT FAST ZONAL FLOW WILL
BRING RENEWED PRECIP CHANCES FOR BOTH FRIDAY AND NEW YEAR`S EVE.
AS IS USUALLY THE CASE IN SUCH A PATTERN...THE MEDIUM RANGE GUIDANCE
CONTINUES TO HAVE TROUBLE COMING INTO CONVERGENCE ON THE TIMING AND
EXACT POSITIONING OF SUCH SYSTEMS...SO BROADBRUSH CHANCE POPS WILL
REMAIN IN ORDER FOR THE END OF THE WEEK. WITH THE PREVAILING ZONAL
FLOW...SOME MODERATION IN TEMPS FROM WEDNESDAY`S COLDER READINGS
SHOULD DEVELOP...WHICH SHOULD BE SUPPORTIVE OF A RAIN/SNOW SHOWER
MIX DEPENDING UPON THE TIME OF DAY.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
THROUGH 15Z...LINGERING MVFR CIGS ARE CONFINED TO THE NIAGARA
FRONTIER...WITH THIS BAND ERODING AS FORECAST BY MOST MODELS.
EXPECT ALL SITES TO BE VFR FOR MUCH OF TODAY...BEFORE A SHORTWAVE
BRINGS SHOWERS AND LOWERING CONDITIONS THIS EVENING.
SCATTERED RAIN SHOWERS WILL DEVELOP LATE THIS AFTERNOON AND EARLY
EVENING BEFORE MIXING WITH AND CHANGING TO SNOW SHOWERS OVERNIGHT.
EXPECT CIGS/VSBY TO BE VFR AT FIRST AS THE LOW LEVELS REMAIN
UNSATURATED. CONDITIONS WILL DETERIORATE TO MVFR BY MID TO LATE
EVENING AS SNOW SHOWERS BECOME MORE WIDESPREAD. SOME IFR WILL
DEVELOP AS WELL IN MORE PERSISTENT SNOW EAST OF LAKES ERIE AND
ONTARIO. THIS WILL TARGET THE CHAUTAUQUA RIDGE INCLUDING KJHW OFF
LAKE ERIE...AND THE TUG HILL REGION BETWEEN KART AND KSYR EAST OF
LAKE ONTARIO.
OUTLOOK...
MONDAY...VFR/MVFR WITH WITH MORNING SNOW SHOWERS SOUTHEAST OF THE
LAKES...THEN VFR.
TUESDAY AND TUESDAY NIGHT...MVFR IN RAIN SHOWERS CHANGING TO SNOW
SHOWERS TUESDAY NIGHT.
WEDNESDAY AND THURSDAY...MAINLY VFR.
&&
.MARINE...
A MODERATE TO STRONG PRESSURE GRADIENT WILL DEVELOP TODAY ACROSS THE
LOWER LAKES BETWEEN LOW PRESSURE OVER NORTHERN QUEBEC AND HIGH
PRESSURE OVER THE SOUTHEAST STATES. A LOW LEVEL JET WILL PEAK THIS
AFTERNOON AT 40 KNOTS...HOWEVER NOT ALL OF THIS WILL MIX DOWN TO
THE LAKE SURFACE. BEST WINDS THROUGH MID-MORNING HAVE BEEN ON THE
NORTH SHORES OF EACH OF THE LAKES...WITH SURFACE TEMPERATURES IN
THE UPPER 30S ADVECTING ACROSS WATER TEMPS IN THE LOWER 40S.
TEMPERATURES WILL WARM INTO THIS AFTERNOON...SO WHILE THE LOW
LEVEL JET STRENGTHENS...LESS MIXING SHOULD OFFSET THIS. WITH WINDS
SHIFTING MORE WSW LATE AFTERNOON...FUNNELING SHOULD BRIEFLY PUSH
WINDS TO 30 KTS ON EASTERN PORTIONS OF LAKE ERIE.
THE LOW LEVEL JET WILL DIMINISH BEHIND THE FRONT...BUT BETTER
MIXING IN THE COLD AIR ADVECTION WILL KEEP WINDS UP OVERNIGHT
ACROSS THE LAKES.
WINDS AND WAVES WILL SUBSIDE MONDAY AS A NARROW RIDGE OF HIGH
PRESSURE BUILDS OVER THE LOWER LAKES. THIS WILL BE SHORT LIVED AS
THE PRESSURE GRADIENT PICKS UP AGAIN MONDAY NIGHT AHEAD OF THE NEXT
LOW MOVING ACROSS ONTARIO AND QUEBEC...PRODUCING MORE SMALL CRAFT
ADVISORY CONDITIONS.
&&
.CLIMATE...
BUFFALO AND ROCHESTER AIRPORTS OFFICIALLY HAD NOW SNOW ON THE
GROUND ON CHRISTMAS MORNING...MAKING 2011 A GREEN CHRISTMAS FOR
BOTH LOCATIONS. WHETHER IT IS A WHITE CHRISTMAS OR NOT IS BASED ON
THE READING TAKING AT 700 AM ON CHRISTMAS MORNING...SO EVEN IF
MEASURABLE SNOW DOES OCCUR THIS EVENING...IT WOULD BE TOO LATE FOR
THE RECORD BOOKS. HOWEVER...SATELLITE SHOWS SOME SNOW ACROSS
PORTIONS OF THE SOUTHERN TIER AND A FEW OF THE FAR SOUTH
TOWNS...AS WELL AS THE TUG HILL...SO THOSE IN SEARCH OF SNOW TO
NOT HAVE TO GO TOO FAR.
THE WINTER OF 2011-12 HAS STARTED AT A RECORD SLOW PACE IN THE
SNOWFALL CATEGORY ACROSS WESTERN AND CENTRAL NEW YORK. THROUGH
DECEMBER 24TH...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 UNTIL 4 AM EST MONDAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LOZ030.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR LOZ043>045.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR LOZ042.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
CLIMATE...THOMAS/HITCHCOCK/JJR/APFFEL
AREA FORECAST DISCUSSION...UPDATED
NWS NEWPORT/MOREHEAD CITY NC
1053 AM EST SUN DEC 25 2011
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY WILL REMAIN WELL SOUTH OF NORTH
CAROLINA TODAY. A DRY COLD FRONT WILL CROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY. 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 NEXT WEEK.
&&
.NEAR TERM /REST OF CHRISTMAS DAY/...
AS OF 1040 AM SUN...MID/HIGH CLOUDS CURRENTLY STREAMING EAST
ACROSS THE REGION ASSOCIATED WITH A LOW PRESSURE SYSTEM PUSHING
EAST ALONG A STALLED FRONTAL BOUNDARY WELL SOUTH OF THE REGION.
BUMPED TEMPS DOWN A FEW DEGREES GIVEN EXPECTED CLOUD COVER...TO
LOWER 60S FOR THE SOUTHERN COASTAL PLAINS. TEMPS ARE RECOVERING
QUICKLY LATE THIS MORNING WITH OAJ/EWN ALREADY 52 DEGREES. LIGHT
SOUTHERLY WINDS WILL VEER SOUTHWEST AND INCREASE 5 TO 10 KNOTS
THIS AFTERNOON IN RESPONSE TO A GRADIENT BETWEEN LOW PRESSURE
SOUTH OF THE REGION AND HIGH PRESSURE BUILDING NORTH OF THE AREA.
LATEST 12Z NAM/14Z RUC KEEP PRECIP OFF THE COAST LATE THIS EVENING
AND OVERNIGHT SO NO SIGNIFICANT CHANGES FOR POPS/WX WITH THIS UPDATE.
&&
.SHORT TERM /TONIGHT/...
AS OF 645 AM SUNDAY...MID LVL SHTWV PASSES TO THE N BRINGING A DRY
COLD FRONT THROUGH THROUGH THE AREA WITH BRISK W-NW WINDS AND
CLEARING SKIES. EXPECT MINS TONIGHT WILL RANGE FROM THE MID AND
UPR 30S INLAND TO THE LWR 40S ON THE COAST WITH STRONG COLD AIR
ADVECTION BEHIND THE FRONT
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
SHORTWAVE RIDGE TRAVERSES THE AREA MON WITH TEMPS NEAR TO SLIGHTLY
BELOW NORMAL UNDER MOSTLY SUNNY SKIES. TEMPS WILL COOL RAPIDLY MON
EVE AS SFC HIGH PRES MOVES OVER THE AREA. WINDS VEER SE LATE MON
NIGHT AND THE DEVELOPING ONSHORE MAY CAUSE TEMPS TO RISE DURING
EARLY TUE MORNING. POTENT SOUTHERN STREAM SHORTWAVE MOVING THRU THE
TENN VALLEY EARLY TUE MERGES WITH A NORTHERN STREAM SYSTEM MOVING
THRU THE UPPER MIDWEST. ASSOCD COLD FRONT WILL SLICE THRU EASTERN NC
DURING THE LATE AFTN AND EARLY EVE. MODELS HAVE SLOWED THE FRONT A
BIT BUT ARE IN GOOD AGREEMENT IN SUGGESTING A DECENT COVERAGE OF
SHOWERS AHEAD OF AND IMMEDIATELY ALONG THE FRONT SO HAVE INCREASED
POPS INTO THE LIKELY RANGE FOR THIS TIME PERIOD. CONTINUING TO
MENTION ISOLD TSTM ALTHO INSTABILITY WILL BE MARGINAL. QPF AMOUNTS
ARE EXPECTED TO BE NEAR HALF AN INCH WITH SOME AREAS POSSIBLY UP TO
AN INCH. MILD TEMPS (60S) WILL BE A RESULT OF A SHARP LOW LEVEL
THICKNESS RIDGE MOVING IN DURING THE AFTN BUT HAVE SHAVED OFF A FEW
DEGREES GIVEN THE EXPECTED CLOUD AND PCPN COVERAGE.
PRECIP WILL BE MOVING OFF THE COAST TUE NIGHT BUT MAY LINGER OVER
OBX INTO EARLY WED MORN AS THE MAIN UPPER TROF AND WRAPAROUND
MOISTURE PASS JUST NE OF THE AREA.
RIDGING DEVELOPS AT THE SURFACE WED THROUGH FRI WITH ZONAL FLOW
ALOFT. 00Z OPERATIONAL GFS RUN DEVELOPS LOW PRES OFF THE SE COAST
THU AND MOVES UP THE NC COAST THU NIGHT BUT THIS IS DISCOUNTED
GIVEN THE LACK OF SUPPORT FROM OTHER MODEL GUIDANCE. TEMPS WILL BE
NEAR SEASONAL LEVELS...MID 50S...WED INTO THURS THEN INCREASE TO
SLIGHTLY ABOVE NORMAL (LOW 60S) FRI/SAT. MIN TEMPS WILL ALSO BE NEAR
SEASONAL LEVELS WITH LOWS IN THE MID-UPPER 30S WITH 40S FOR OBX. A
COLD FRONT MAY APPROACH THE AREA FROM THE NW ON SAT BUT WILL NOT
MENTION PRECIP AS YET AWAITING BETTER LONG RANGE MODEL CONSENSUS.
&&
.AVIATION /16Z SUNDAY THROUGH THURSDAY/...
SHORT TERM / THROUGH TONIGHT/...
AS OF 645 AM SUNDAY...VFR CONDITIONS EXPECTED THROUGH TODAY. MID
AND HIGH CLOUDS INCREASE ACROSS THE AREA TODAY WITH WINDS BECOMING
SOUTHWEST AS LOW PRESSURE TRACKS WELL TO THE SOUTH. A STRONG DRY
COLD FRONT MOVES THROUGH AFTER MIDNIGHT TONIGHT WITH WINDS BECOMING
WEST THEN NORTHWEST AROUND 10 KT. THUS EXPECT SURFACE WINDS AND
MODERATE DEWPOINT DEPRESSIONS TO INHIBIT FOG FORMATION OR LOW STRATUS.
LONG TERM /MONDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED MON AS HIGH PRESSURE BUILDS ACROSS THE
AREA. RETURN FLOW SETS UP LATE MON NIGHT AND STRENGTHENS TUE AS A
COLD FRONT APPROACHES FROM THE WEST. MVFR/POSSIBLE IFR CONDITIONS
EXPECTED TUE AFTERNOON AND EVENING AS SHOWERS WITH ISOLATED
THUNDERSTORMS PASS THROUGH THE REGION. HIGH PRESSURE BUILDS BACK
OVER THE REGION WED/THU WITH MAINLY VFR EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH CHRISTMAS NIGHT/...
AS OF 1045 AM SUN...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
LIGHT WINDS AROUND 5 KNOTS...WITH AN OFFSHORE SHIP REPORT OF 10
KNOTS OUT OF THE NORTH FROM WDD3825. SEAS REMAIN LONG PERIOD
SWELLS 2 TO 3 FT OFF DUCK TO OFF ONSLOW BAY. WINDS WILL SHIFT TO
SOUTH THEN SOUTHWEST AS THE DAY PROGRESSES...AND INCREASE 10 TO 15
KNOTS BY LATE THIS EVENING.
WEAK LOW PRESSURE MOVING ALONG A STALLED FRONT OFF OF THE SE
COAST SHOULD REMAIN WEAK AND FAR ENOUGH SOUTH SO AS NOT TO
INFLUENCE LOW LEVEL FLOW TODAY. HOWEVER...SOME SPOTTY LIGHT RAIN
COULD DEVELOP LATE OVER THE SOUTHERN WATERS. A STRONG DRY COLD
FRONT MOVES THROUGH THE AREA TONIGHT WITH SCA CONDITIONS EXPECTED
FOR ALL OF THE WATERS BY 06Z WITH W-NW WINDS INCREASING TO 20-25
KT AND SEAS BUILDING TO 5-7 FT.
LONG TERM /MONDAY THROUGH THURSDAY/...
SCA CONDITIONS WILL CONTINUE THRU MONDAY IN A MODERATE TO STRONG
POST FRONTAL NORTH FLOW. WINDS/SEAS WILL DECREASE QUICKLY MON NIGHT
AS HIGH PRES BUILDS INTO THE REGION. A VEERING FLOW WILL AGAIN
INCREASE AHEAD OF A COLD FRONT ON TUESDAY WITH A RETURN TO SMALL
CRAFT ADVISORY CONDITIONS EXPECTED BY MIDDAY OR SO. WINDS/SEAS PEAK
LATE TUE AFTN AND EVE (WITH A FEW NEAR GALE FORCE GUSTS POSSIBLE)
THEN A GRADUAL DECREASE AS LOW LEVEL CAA WANES IN THE POST FRONTAL
NW/N FLOW LATE TUE NIGHT INTO WED AS BROAD HIGH PRESSURE MIGRATES
EAST ACROSS THE WATERS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
MONDAY FOR AMZ130-135-156-158.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 PM EST
MONDAY FOR AMZ150-152-154.
&&
$$
SYNOPSIS...DAG
NEAR TERM...DAG
SHORT TERM...JAC
LONG TERM...BTC/DAG
AVIATION...JAC/BTC/RF/DAG
MARINE...JAC/BTC/RF/DAG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
915 AM EST SUN DEC 25 2011
.SYNOPSIS...
A QUICK MOVING UPPER LEVEL DISTURBANCE WILL BRING A BRIEF CHANCE OF
RAIN LATE THIS AFTERNOON INTO 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 915 AM SUNDAY...THICKER AND OPAQUE CLOUDINESS TO OVERSPREAD
THE AREA AND AID IN KEEPING MAX TEMPS FROM CLIMBING OUT OF THE 50S.
THE EXCEPTION WILL BE COASTAL SE NC AND NE SC WHERE THE OPAQUE
OVERCAST WILL FILL IN AROUND MIDDAY ALLOWING SOME INSOLATION TO AID
MAX TEMPS REACHING INTO THE 60S. HRRR THE PAST FEW HRS HAS BACKED
DOWN ON THE PCPN COVERAGE LATER THIS AFTERNOON AND EVENING. WILL
TWEAK POPS SLIGHTLY LOWER ESPECIALLY ACROSS THE ILM NC COUNTIES.
PREVIOUS DISCUSSION...............................................
AS OF 630 AM SUNDAY...A SURFACE RIDGE EXTENDING FROM THE DELMARVA
PENINSULA WEST ACROSS THE NC/VA MOUNTAINS AND INTO ARKANSAS WILL
REMAIN ACROSS THE AREA THROUGH THIS EVENING. MORE IMPORTANT TO OUR
WEATHER WILL BE A SHORTWAVE TROUGH CURRENTLY LOCATED ACROSS
MISSISSIPPI THAT WILL MOVE EAST AND ACROSS THE CAROLINAS EARLY THIS
EVENING. A SLUG OF MID-LEVEL MOISTURE FROM THE GULF OF MEXICO AND
LOW-LEVEL MOISTURE FROM BOTH THE GULF AND ATLANTIC WILL GET PULLED
OVERHEAD THIS AFTERNOON. WHEN COUPLED WITH THE WEAK LIFT PROVIDED BY
THE TROUGH WE ARE FORECASTING RAIN CHANCES LATE THIS AFTERNOON AND
EVENING...MAINLY ACROSS SOUTH CAROLINA AND AFTER 2-3 PM. THERE WILL
BE A SHORT WINDOW OF OPPORTUNITY FOR RAIN TO FALL...AND GIVEN THE
MEAGER LIFT ADVERTISED ON THE LATEST GFS/NAM RUNS OUR ACTUAL
RAINFALL FORECASTS ARE FOR 0.05 INCHES OR LESS.
AS THE SHORTWAVE TROUGH EXITS THE COAST THIS EVENING...HIGH PRESSURE
OVER THE CENTRAL PLAINS STATES WILL BUILD EAST AND INTO THE
CAROLINAS. THIS WILL CREATE A SURGE OF COLD NORTHWESTERLY WINDS
AFTER MIDNIGHT THAT WILL CONTINUE THROUGH DAYBREAK MONDAY. HIGHS
TODAY SHOULD RANGE FROM 55-60...WARMEST AT THE COAST. LOWS TONIGHT
SHOULD FALL INTO THE UPPER 30S MOST LOCATIONS.
NOTE: DUE TO COMPUTER PROBLEMS AT NCEP THE 00Z NAM MOS PRODUCTS WERE
NOT PRODUCED.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...FOCUS FOR THE SHORT TERM WILL BE UPPER SYSTEM
TRACKING NORTHEAST FROM TX MON NIGHT. AHEAD OF THE OPENING WAVE VERY
DRY HIGH PRESSURE BUILDING IN MON WILL SHIFT OFF THE NC/VA COAST MON
NIGHT. ANTICIPATE VERY LITTLE IN THE WAY OF CLOUDS MON LET ALON
PRECIP. COLD ADVECTION WILL BE ENDING MON MORNING BUT COOLER AIR
WILL ALREADY BE IN PLACE ENSURING HIGHS RIGHT AROUND CLIMO. RETURN
FLOW DEVELOPING LATE MON NIGHT WILL START TEMPS/DEWPOINTS ON A
GRADUAL UPWARD TREND BEFORE DAYBREAK.
WEAK COASTAL TROF/WARM FRONT MOVES ONSHORE FAIRLY EARLY TUE HELPING
BREAK VERY WEAK WEDGE. STRONG WARM ADVECTION RAPIDLY INCREASES LOW
LEVEL MOISTURE WHILE STRONG SOUTH TO SOUTHWEST MID LEVEL FLOW
INCREASES MOISTURE ABOVE 900 MB. HAVE HELD ONTO LIKELY POP FOR TUE
GIVEN THAT THERE IS STILL SOME QUESTION WITH RESPECT TO TIMING.
WHILE GOOD AGREEMENT BETWEEN THE GUIDANCE CONTINUES...NEARLY ALL OF
THE 00Z SOLUTIONS ARE SLOWER BY ABOUT 6 HOURS OR SO. NOT ONLY WOULD
SLOWER EVOLUTION DELAY PRECIP BUT IT WOULD AFFECT TEMP FORECAST AND
CREATE A LARGER WINDOW FOR CONVECTION. INCREASING INSTABILITY WITHIN
THE WARM SECTOR...DEEP MOISTURE...STRONG DIVERGENCE ALOFT...AND
STRONG LOW LEVEL JET DO POINT TO THE POTENTIAL FOR SOME ISOLATED
STRONG CONVECTION...ESPECIALLY IF THE SLOWER SOLUTION COMES TO PASS.
RAINFALL AMOUNTS IN THE HALF INCH RANGE ARE EXPECTED THOUGH ISOLATED
HIGHER AMOUNTS ARE CERTAINLY POSSIBLE.
COLD FRONT MOVES ACROSS THE AREA LATE TUE FOLLOWED BY A BRIEF PERIOD
OF WEAK COLD ADVECTION. BOUNDARY LAYER MIXING AND LACK OF
SIGNIFICANT COLD ADVECTION KEEPS TUE NIGHT LOWS NEAR TO SLIGHTLY
ABOVE CLIMO...WITH COOLEST AREAS TO THE WEST.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...AS 5H TROF EXITS NORTHEAST WED MORNING THE
PATTERN ALOFT WILL BECOME MORE PROGRESSIVE. ZONAL PATTERN WILL
REMAIN IN PLACE THROUGH THE PERIOD...THOUGH SOME WEAK RIDGING DOES
START TO CREEP IN NEXT WEEKEND. A FEW WEAK MOISTURE STARVED WAVE
WILL PASS JUST NORTH OF THE AREA...BUT A FEW CLOUDS IS ALL THAT CAN
BE EXPECTED. TEMPERATURES NEAR CLIMO FOR MUCH OF THE PERIOD WILL
CREEP ABOVE CLIMO LATE IN THE PERIOD.
IT IS WORTH NOTING THE 00Z GFS IS NOW SHOWING A WEAK WAVE OFF THE
SOUTHEAST COAST THU WHICH MOVES NORTH INTO FRI. ONCE THE LOW REACHES
HATTERAS DIVERGENCE ALOFT...ASSOCIATED WITH SHORTWAVE DIGGING OVER
THE GREAT LAKES...HELPS STRENGTHEN THE LOW. ONLY THE 00Z GFS DEPICTS
THIS SOLUTION AND IT SEEMS OVER AMPLIFIED. WILL IGNORE IT FOR NOW.
&&
.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
AS OF 12Z...MOISTURE WILL BE ON THE INCREASE TODAY. LOOK FOR
THICKENING HIGH CLOUDS THIS MORNING...WITH A CHANCE FOR PATCHY LIGHT
RAIN MAINLY OVER THE SOUTHERN TERMINALS. EVEN WITH THE POSSIBLE
PRECIP...CEILINGS ARE EXPECTED TO REMAIN VFR INTO THE EVENING HOURS.
POSSIBLY LOWERING TO MVFR BEHIND THE FRONT TONIGHT.
OVERNIGHT...WINDS WILL SLOWLY SHIFT TO THE NORTHWEST AS THE FRONT
SAGS SOUTHEAST OF THE CWA...TAKING THE MOISTURE WITH IT. SCATTERED
SKIES ARE EXPECTED BY THE END OF THE FORECAST PERIOD.
EXTENDED OUTLOOK...ANTICIPATE VFR THROUGH MONDAY. POSSIBLE SHOWERS
AND IFR CONDITIONS TUESDAY. VFR WEDNESDAY AND THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 915 AM SUNDAY...SFC BOUNDARY TO NEARLY SPLIT THE ILM COASTAL
WATERS TODAY. WIND DIRECTIONS WILL BE THE PROBLEM CHILD WITH WIND
SPEEDS 10 KT OR LESS DUE TO A RELAXED SFC PG. WILL INDICATE A
VARIABLE WIND DIRECTION THIS AFTERNOON. COLD FRONT DROPS SE AND
SWEEPS ACROSS THE ILM WATERS AND OFFSHORE THIS EVENING. TIGHTENED
SFC PG IN THE WAKE OF THE FRONT AND CAA SURGE TO PUSH W TO NW WINDS
TO SCA CRITERIA FOR THE ILM NC WATERS AROUND MIDNIGHT...AND
CONTINUING AT THESE SPEEDS THROUGH DAYBREAK MONDAY. THE ILM SC
WATERS WILL SEE 15-20 KT SPEEDS. SIGNIFICANT SEAS WILL BE DOMINATED
BY AN EASTERLY 1-3 FT SWELL AT 7 TO 9 SECOND PERIODS TODAY. DUE TO
THE NW FETCH...EXPECT 2 TO 4 FT LOCALLY PRODUCED WIND WAVES AT 3-5
SECOND PERIODS BECOMING THE DOMINATE PLAYER AFTER THE COLD FRONT
PUSHES THIS EVENING.
PREVIOUS DISCUSSION...............................................
AS OF 630 AM SUNDAY...A RIDGE OF HIGH PRESSURE ACROSS SOUTHERN
VIRGINIA WILL REMAIN JUST TO OUR NORTH THROUGH EARLY THIS EVENING.
THIS SHOULD MAINTAIN LIGHT WINDS ACROSS THE COASTAL WATERS. AN
UPPER LEVEL DISTURBANCE COULD BRING A PERIOD OF LIGHT RAIN LATE
THIS AFTERNOON INTO EARLY THIS EVENING ACROSS MAINLY THE SOUTH
CAROLINA WATERS. ANY RAIN SHOULD SHIFT OFFSHORE BEFORE MIDNIGHT.
HIGH PRESSURE OVER THE CENTRAL PLAINS WILL SURGE EAST LATE TONIGHT
BRINGING INCREASING NORTHWESTERLY WINDS WHICH COULD REACH 25 KNOTS
ACROSS THE NORTH CAROLINA WATERS. WE ARE THEREFORE HOISTING A SMALL
CRAFT ADVISORY NORTH OF LITTLE RIVER INLET BEGINNING AT 2 AM MONDAY.
SEAS ARE CURRENTLY 3 FT AT THE FRYING PAN SHOALS BUOY AND 3 FT AT
THE NEARSHORE WRIGHTSVILLE BEACH BUOY. SINCE WINDS ARE FAIRLY LIGHT
A CHECK OF THE SPECTRAL WAVE PLOT CONFIRMS WE ARE MAINLY
EXPERIENCING AN 8-SECOND SWELL. SEAS SHOULD CHANGE LITTLE THROUGH
THIS EVENING...BUT AFTER MIDNIGHT INCREASING OFFSHORE WINDS WILL
DEVELOP A SHORT PERIOD (3-5 SECOND) CHOP LATE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BRIEF NORTHERLY SURGE WILL BE WEAKENING MON
MORNING BUT MAY REQUIRE HEADLINES FOR THE FIRST FEW HOURS OF THE
PERIOD. WINDS QUICKLY DROP BELOW 15 KT AND VEER TO NORTH-NORTHEAST
MON INTO MON NIGHT AS HIGH PRESSURE SHIFTS OFF THE NC/VA COAST. WARM
FRONT MOVES ONSHORE LATE MON NIGHT WITH WINDS BECOMING ONSHORE AND
INCREASING AS GRADIENT TIGHTENS. COOLER NEARSHORE WATER TEMPS WILL
LIMIT GUSTINESS BUT COULD ALSO RESULT IN SOME SEA FOG. HEADLINES
WILL LIKELY BE NEEDED TUE AS BOTH WINDS AND SEAS ARE EXPECTED TO
EXCEED THRESHOLDS AS DEEPENING LOW PRESSURE MOVES ACROSS THE
CAROLINAS. STRONG COLD FRONT CROSSES THE WATERS TUE NIGHT WITH
STRONG SOUTHWEST FLOW IN ITS WAKE BECOMING WESTERLY. NOT A LOT OF
COLD ADVECTION BEHIND THE FRONT SO WINDS MAY NOT BE VERY GUSTY...BUT
PINCHED GRADIENT WILL KEEP WINDS 15 TO 20 KT INTO WED MORNING. 2 TO
3 FT SEAS MON AND MON NIGHT WILL BUILD TO 6 TO 9 FT BEFORE COLD
FRONT SWEEPS ACROSS THE WATERS TUE NIGHT. SEAS WILL SLOWLY FALL TUE
NIGHT AS WINDS BECOME WEST AND THEN NORTHWEST.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...LIGHT WEST TO NORTHWEST FLOW WED AS HIGH
PRESSURE MOVES MOVES EAST ACROSS THE GULF COAST. WINDS BECOME LIGHT
AND VARIABLE LATE WED NIGHT AS RIDGE AXIS ELONGATES AND SHIFTS
SOUTHEAST OF THE AREA. LIGHT RETURN FLOW DEVELOPS BY THU BUT
GRADIENT REMAINS WEAK. SPEEDS THROUGH THE PERIOD WILL GENERALLY BE
10 KT OR LESS WITH SEAS 2 TO 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/TRA
SHORT TERM...III
LONG TERM...III
AVIATION...HDL
AREA FORECAST DISCUSSION
NWS GOODLAND KS
1221 PM MST SUN DEC 25 2011
.SYNOPSIS...
IR SATELLITE IMAGERY SHOWED CLEAR SKIES OVER THE CENTRAL PLAINS.
LATEST RUC UPPER AIR ANALYSIS SHOWED THE WESTERN HALF OF THE CONUS
UNDER AN UPPER LEVEL RIDGE...AND A CLOSED LOW REMAINING NEARLY
STATIONARY OVER WESTERN TEXAS AND EASTERN NEW MEXICO. AT THE
SURFACE...HIGH PRESSURE WAS MAKING ITS WAY INTO THE TRI-STATE
AREA.
JTL
&&
.SHORT TERM (TODAY-TUESDAY)...
223 AM MST SUN DEC 25 2011
MAIN ISSUE WITH THE FORECAST WILL BE TEMPERATURES. FOR MOST OF THE
AREA TEMPERATURES WILL CONTINUE TO BE NEAR OR ABOVE NORMAL THROUGH
THE PERIOD. OVER THE AREAS THAT HAVE EXCESSIVE SNOW COVER
TEMPERATURES WILL BE 5 TO 10 DEGREES COOLER.
UPPER LEVEL AND SURFACE HIGH PRESSURE WILL REMAIN OVER THE TRI-STATE
AREA TODAY THROUGH EARLY MONDAY WITH THE UPPER LEVEL CLOSED LOW
WOBBLING OVER THE TEXAS PANHANDLE. WINDS WILL BE LIGHT AS A SURFACE
HIGH PRESSURE MOVES ACROSS THE AREA TODAY.
MONDAY A SHORT WAVE TROUGH MOVES THROUGH THE UPPER LEVEL FLOW
PUSHING THE CLOSED LOW EAST. AT THE SURFACE A PRE-FRONTAL TROUGH WILL
ACCOMPANY THE UPPER LEVEL FEATURE. WITH A STRONGER PRESSURE
GRADIENT IN PLACE AS THE TROUGH MOVES THROUGH...WINDS WILL
STRENGTHEN AHEAD AND ESPECIALLY BEHIND THE TROUGH. WINDS WILL
BECOME GUSTY AS STRONGER WINDS ABOVE THE SURFACE ARE ABLE TO MIX
DOWN TO THE GROUND. COOLER AIR WILL MOVE IN BEHIND THE TROUGH.
WINDS WILL WEAKEN OVERNIGHT AS HIGH PRESSURE BUILDS IN BEHIND THE
TROUGH.
TUESDAY A SHORT WAVE TROUGH WILL MOVE THROUGH THE UPPER LEVEL FLOW
OVER THE AREA DURING THE EVENING. UPPER LEVEL MOISTURE INCREASES AND THERE
IS SOME LIFTING ASSOCIATED WITH THE TROUGH PASSAGE. HOWEVER A DRY
LAYER REMAINS BETWEEN THE MOISTURE AND THE SURFACE WHICH WILL LIKELY
EVAPORATE ANY PRECIPITATION THAT MAY FORM.
JTL
.LONG TERM (WEDNESDAY-SATURDAY)...
223 AM MST SUN DEC 25 2011
A WEAK UPPER LEVEL DISTURBANCE MOVES OUT OF THE NORTHERN ROCKIES ON
THURSDAY. BEST LIFT AND MOISTURE WILL BE FAR TO THE NORTH OF THE
LOCAL AREA. OTHERWISE...A DRY WESTERLY FLOW WILL DOMINATE WITH NO
PRECIPITATION CHANCES AND TEMPERATURES ABOVE NORMAL. /024
&&
.AVIATION...
1215 PM MST SUN DEC 25 2011
KMCK AND KGLD WILL HAVE VFR CONDITONS WITH LIGHT NORTHWEST WINDS
THROUGH THE REMAINDER OF SUNDAY...SUNDAY NIGHT AND MONDAY. WINDS WILL
TURN SOUTHWEST OVERNIGHT AND THEN BECOME WEST ON SUNDAY.
LOCKHART
&&
.GLD WATCHES/WARNINGS/ADVISORIES...
KS...NONE.
NE...NONE.
CO...NONE.
&&
$$
AREA FORECAST DISCUSSION
NWS TWIN CITIES/CHANHASSEN MN
250 PM CST SUN DEC 25 2011
.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 SO 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 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.../18Z TAF ISSUANCE/
NO SIGNIFICANT AVIATION CONCERN...EXCEPT GUSTY WINDS OVER THE NEXT
24 HOURS. SOUTH-SOUTHWEST WINDS INCREASING OVER THE UPPER MIDWEST
AHEAD OF THE SURFACE TROUGH TONIGHT. PRESSURE GRADIENT WILL TIGHTEN
OVER THE FORECAST AREA LATER TONIGHT...WITH OCCASIONAL GUSTS TO
AROUND 25 KNOTS. WEATHER CONDITIONS WILL REMAIN VFR WITH CLOUDS
GENERALLY OVER MUCH OF THE AREA OVER 20 THOUSAND FEET AGL. SOME
SCATTERED CUMULUS AROUND 3000 FEET AGL OVER WEST CENTRAL WISCONSIN
THIS AFTERNOON. ONLY PROBLEM TODAY WILL BE GUSTY WEST WINDS AROUND
20 KNOTS. GRADIENT WILL RELAX LATER TODAY BEFORE TIGHTEN AGAIN
TONIGHT.
MSP...VFR CONDITIONS WILL PREVAIL THROUGH THE PERIOD. ONLY AVIATION
CONCERN WILL BE GUSTY SOUTH-SOUTHWEST WINDS DEVELOPING LATER
TONIGHT/MONDAY MORNING.
&&
.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.
&&
$$
AREA FORECAST DISCUSSION
NWS DULUTH MN
1148 AM CST SUN DEC 25 2011
.AVIATION...18Z TAFS.
MVFR CIGS COVER THE TAF SITES. HOWEVER...KBRD WILL SCT OUT BY 20Z
WITH CLEARING LINE JUST TO THE SW. ELSEWHERE...CONTINUE THE
THINKING OF CLEARING OCCURRING AT THE OTHER SITES BETWEEN 21Z AND
23Z REACHING VFR. SFC RIDGE AXIS MOVES OVERHEAD OVERNIGHT.
MEANWHILE...LLWS POTENTIAL INCREASES FROM 05Z TO 07Z AT ALL SITES
AS STRONG WAA OCCURS IN THE LOWEST 2K FT AND UP AS WIND SPEED
INCREASES AOA 40KT AND PERSISTS THROUGH THE TAF CYCLE.
&&
.PREV DISCUSSION... /ISSUED 1026 AM CST SUN DEC 25 2011/
UPDATE...
AT 1615 UTC...THE NORTHLAND WAS IN NORTHWEST FLOW. THERE WAS A
WIDESPREAD BLANKET OF OVERCAST STRATUS COVERING OF THE MOST OF THE
FA...AS WELL AS UPSTREAM IN EASTERN MANITOBA AND ONTARIO.
OBSERVATIONS WERE GENERALLY RECORDING NORTHWEST WINDS BETWEEN 10
AND 20 MPH WITH GUSTS UP TO ABOUT 25 MPH. A RIDGE OF HIGH PRESSURE
AND HIGH CIRRUS CLOUDS WERE IN THE HIGH PLAINS OF THE WESTERN
DAKOTAS AND MONTANA AND APPROACHING THE NORTHLAND.
LOOKING UPSTREAM AT THE OVERCAST STRATUS DECK POURING OUT OF
CANADA...IT IS REMINISCENT OF A SITUATION EARLY LAST WEEK. THINK
THIS WILL BE ANOTHER CASE WHERE THE FORECASTED AFTERNOON CLEARING
WILL HAVE A DIFFICULT TIME DEVELOPING. THINK THE LOWER CONVECTIVE
TEMPERATURES IN THIS COLD NORTHWEST FLOW WILL ALLOW THE SUN TO
ATTEMPT TO FILL ANY CLEARING THAT TRIES TO FORM BY DEVELOPING
REINFORCING STRATOCUMULUS. STILL PLANNING ON SEEING CLEARING...BUT
THINK IT WILL BE SIGNIFICANTLY DELAYED...ESPECIALLY ACROSS THE
EASTERN FA. LEANED ON THE WEB BASED HRRR MODEL...WHICH DID FAIRLY
WELL WITH THE SIMILAR SITUATION LAST WEEK.
MADE SOME TWEAKS TO TEMPERATURES...ESPECIALLY SINCE SOME LOCATIONS
WERE PROBABLY ALREADY NEAR THEIR FORECASTED HIGH TEMPERATURES.
THE OVERCAST SKIES WILL PREVENT MUCH MORE WARMING TODAY...EXCEPT
ACROSS THE WESTERN FA WHICH WILL SEE BETTER CLEARING THIS
AFTERNOON. INCREASED WINDS A BIT TOO...INCLUDING WIND GUSTS.
WILL KEEP AN EYE ON THESE CLOUD TRENDS THROUGH THE AFTERNOON.
HAVE SOME DOUBTS ABOUT WHETHER THE TWEAKED SKY COVER FORECAST
DELAYED THE CLEARING ENOUGH.
PREV DISCUSSION... /ISSUED 610 AM CST SUN DEC 25 2011/
AVIATION...12Z TAFS
WIDESPREAD MVFR CONDITIONS WITH -SHSN OR FLURRIES WILL BE FOUND
THROUGH MID MORNING...THEN IMPROVING CONDITIONS AND CLEARING SKIES
IN THE AFTERNOON. SFC WINDS WILL REMAIN GUSTY OUT OF THE NW
THROUGH 18Z...THEN DIMINISH AND BECOME VARIABLE IN THE LATE
AFTERNOON AND EVENING. WINDS WILL INCREASE OUT OF THE SOUTH TO
SOUTHWEST LATE...MAINLY AFTER 08Z. INTRODUCED LLWS TO ALL
TERMINALS OVERNIGHT.
PREV DISCUSSION... /ISSUED 357 AM CST SUN DEC 25 2011/
SHORT TERM...AMPLIFYING SHORTWAVE TROF... ACCOMPANIED BY 120KT
30H JET IS SWINGING ACROSS CWA EARLY THIS MORNING. MAJORITY OF
SYNOPTIC SCALE FORCING IS SPREADING FROM ARROWHEAD/IRON RANGE
SOUTHEAST INTO NW WISCONSIN. SNOW HAS BEEN MOST PERSISTENT WITHIN
COUPLED DGZ/DEEP LYR MOISTURE NORTH OF A KFOZ TO KTWM LINE AS OF
EARLY THIS MORNING. AT SFC..A COLD FRONT STRETCHES FROM NEAR
HUDSON BAY SOUTHWEST TO NEAR CYQT AND WEST INTO SRN MANITOBA. NORTH
OF THIS BDRY...TEMPS/DEWPTS MORE REFLECTIVE OF POLAR AIR WHILE
SOUTH OF THE BDRY AIR HAS A MORE MODIFIED POLAR/PACIFIC TYPE
SOURCE REGION.
TODAY...PROGRESSIVE NATURE OF UPPER FLOW KEEPS CURRENT SFC/MID LVL
SYSTEM MOVING EAST FAIRLY QUICKLY TODAY. EXPECT SNOW TO CONTINUE OVER
NWRN WISC THROUGH MID MORNING WHILE DECREASING OVER MN ZONES. COND
PRESS DEFICITS SUGGEST MOSTLY CLOUDY CONDITIONS OVER MN THRU 18Z
WITH CLEARING FROM WEST TO EAST IN THE AFTN. MOMENTUM TRANSFER
WILL INCREASE WITH CLOUDS DIMINISHING SO EXPECT A PERIOD OF GUSTY
NW WINDS DEVELOPING. LOW LEVEL THERMAL FIELDS DO NOT SUPPORT
SIGNIFICANT LAKE INDUCED INSTABILITY. HOWEVER SYNOPTIC SCALE ASCENT
COMBINED WITH TERRAIN LIFT SHOULD ALLOW SOME 1 TO 2 INCH ACCUMULATION
OVER GOGEBIC RANGE THIS MORNING. SNOW SHOULD DIMINISH BY 21Z OVER
ERN WISC SNOWBELT. CLOUDS AND LOW LVL COLD ADVECTION SHOULD KEEP
TEMP CLIMB TO A MINIMUM OVER ERN CWA TODAY. MILDEST READINGS
EXPECTED ACROSS SWRN CWA WITH MORE SUNSHINE.
TONIGHT/TOMORROW...MID LVL RIDGE MOVES ACROSS CWA TONIGHT WITH
WARM ADVECTION REGIME INCREASING IN STRENGTH. USED BC TEMPS
CONSIDERING ANOMALOUS PATTERN AND LIMITED SNOW COVER. MAY STILL
NEED TO ADJUSTING MIN TEMPS UPWARDS. SHOULD SEE A SHIELD OF
MID/HIGH CLOUDS TRAVERS FROM WEST TO EAST DURING THE DAY MONDAY.
MAX TEMPS MAY REACH 15 TO 20 DEGREES ABOVE NORMS. INTENSE SFC LOW
WILL SWEEP ACROSS SRN MAN INTO SCTRL ONTARIO BY 0Z TUE. WILL HOLD
OFF ON PRECIP FOR NOW BUT LATEST SREF/GEM INDICATE
EXTENDED....MONDAY NIGHT THROUGH SATURDAY
TEMPERATURES WILL RAPIDLY FALL MON NIGHT/TUES AS THE TROUGH DEPARTS
TO THE EAST AND WINDS TURN OUT OF THE NW. LATEST NAM/ECMWF/GFS
CONTINUE TO SHOW AGREEMENT THAT H85 READINGS FALL ON THE ORDER OF
10C FROM 00Z THROUGH 12Z TUESDAY. THE CYCLONIC FLOW WILL KEEP SMALL
CHC FOR LINGERING -SHSN ACROSS THE NRN/ERN ZONES THROUGH TUES. A FAST
MOVING SFC RIDGE WILL PASS OVER THE REGION TUES AFTN/EVENING BEFORE
WINDS INCREASE OUT OF THE SOUTH LATE TUES NIGHT AHEAD OF APPROACHING
WAVE DROPPING SE OUT OF MANITOBA. TIMING OF THE RIDGE PASSING WILL
HAVE SIGNIFICANT EFFECT ON OVERNIGHT LOWS TUES NIGHT WITH CLEARING
AND LIGHT WINDS ASSOCIATED WITH THE RIDGE POTENTIALLY DROPPING THE
TEMPS INTO THE SINGLE DIGITS IN THE NE ZONES...THEN RISING LATE WITH
THE RETURN FLOW.
LONG TERM MODELS BEGIN TO HAVE LARGE DIFFERENCES PAST DAY 4. HAVE
CHC POPS AT THE END OF THE WEEK WITH SOME CONTINUITY THAT A FAST
MOVING WAVE TRANSLATES OVER THE REGION. HOWEVER...THE STRENGTH AND
TIMING OF THIS SYSTEM AND POTENTIAL FOR ANY SNOW ACCUM REMAIN
HIGHLY UNCERTAIN.
&&
.POINT TEMPS/POPS...
DLH 34 23 38 24 / 20 0 0 10
INL 33 22 37 16 / 20 0 10 20
BRD 37 25 42 23 / 10 0 0 0
HYR 36 20 39 24 / 20 0 0 10
ASX 36 23 40 28 / 40 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ146-
147.
&&
$$
SHORT TERM...GROCHOCINSKI
AVIATION...GSF
AREA FORECAST DISCUSSION
NWS DULUTH MN
1026 AM CST SUN DEC 25 2011
.UPDATE...
AT 1615 UTC...THE NORTHLAND WAS IN NORTHWEST FLOW. THERE WAS A
WIDESPREAD BLANKET OF OVERCAST STRATUS COVERING OF THE MOST OF THE
FA...AS WELL AS UPSTREAM IN EASTERN MANITOBA AND ONTARIO.
OBSERVATIONS WERE GENERALLY RECORDING NORTHWEST WINDS BETWEEN 10
AND 20 MPH WITH GUSTS UP TO ABOUT 25 MPH. A RIDGE OF HIGH PRESSURE
AND HIGH CIRRUS CLOUDS WERE IN THE HIGH PLAINS OF THE WESTERN
DAKOTAS AND MONTANA AND APPROACHING THE NORTHLAND.
LOOKING UPSTREAM AT THE OVERCAST STRATUS DECK POURING OUT OF
CANADA...IT IS REMINISCENT OF A SITUATION EARLY LAST WEEK. THINK
THIS WILL BE ANOTHER CASE WHERE THE FORECASTED AFTERNOON CLEARING
WILL HAVE A DIFFICULT TIME DEVELOPING. THINK THE LOWER CONVECTIVE
TEMPERATURES IN THIS COLD NORTHWEST FLOW WILL ALLOW THE SUN TO
ATTEMPT TO FILL ANY CLEARING THAT TRIES TO FORM BY DEVELOPING
REINFORCING STRATOCUMULUS. STILL PLANNING ON SEEING CLEARING...BUT
THINK IT WILL BE SIGNIFICANTLY DELAYED...ESPECIALLY ACROSS THE
EASTERN FA. LEANED ON THE WEB BASED HRRR MODEL...WHICH DID FAIRLY
WELL WITH THE SIMILAR SITUATION LAST WEEK.
MADE SOME TWEAKS TO TEMPERATURES...ESPECIALLY SINCE SOME LOCATIONS
WERE PROBABLY ALREADY NEAR THEIR FORECASTED HIGH TEMPERATURES.
THE OVERCAST SKIES WILL PREVENT MUCH MORE WARMING TODAY...EXCEPT
ACROSS THE WESTERN FA WHICH WILL SEE BETTER CLEARING THIS
AFTERNOON. INCREASED WINDS A BIT TOO...INCLUDING WIND GUSTS.
WILL KEEP AN EYE ON THESE CLOUD TRENDS THROUGH THE AFTERNOON.
HAVE SOME DOUBTS ABOUT WHETHER THE TWEAKED SKY COVER FORECAST
DELAYED THE CLEARING ENOUGH.
&&
.PREV DISCUSSION... /ISSUED 610 AM CST SUN DEC 25 2011/
AVIATION...12Z TAFS
WIDESPREAD MVFR CONDITIONS WITH -SHSN OR FLURRIES WILL BE FOUND
THROUGH MID MORNING...THEN IMPROVING CONDITIONS AND CLEARING SKIES
IN THE AFTERNOON. SFC WINDS WILL REMAIN GUSTY OUT OF THE NW
THROUGH 18Z...THEN DIMINISH AND BECOME VARIABLE IN THE LATE
AFTERNOON AND EVENING. WINDS WILL INCREASE OUT OF THE SOUTH TO
SOUTHWEST LATE...MAINLY AFTER 08Z. INTRODUCED LLWS TO ALL
TERMINALS OVERNIGHT.
PREV DISCUSSION... /ISSUED 357 AM CST SUN DEC 25 2011/
SHORT TERM...AMPLIFYING SHORTWAVE TROF... ACCOMPANIED BY 120KT
30H JET IS SWINGING ACROSS CWA EARLY THIS MORNING. MAJORITY OF
SYNOPTIC SCALE FORCING IS SPREADING FROM ARROWHEAD/IRON RANGE
SOUTHEAST INTO NW WISCONSIN. SNOW HAS BEEN MOST PERSISTENT WITHIN
COUPLED DGZ/DEEP LYR MOISTURE NORTH OF A KFOZ TO KTWM LINE AS OF
EARLY THIS MORNING. AT SFC..A COLD FRONT STRETCHES FROM NEAR
HUDSON BAY SOUTHWEST TO NEAR CYQT AND WEST INTO SRN MANITOBA. NORTH
OF THIS BDRY...TEMPS/DEWPTS MORE REFLECTIVE OF POLAR AIR WHILE
SOUTH OF THE BDRY AIR HAS A MORE MODIFIED POLAR/PACIFIC TYPE
SOURCE REGION.
TODAY...PROGRESSIVE NATURE OF UPPER FLOW KEEPS CURRENT SFC/MID LVL
SYSTEM MOVING EAST FAIRLY QUICKLY TODAY. EXPECT SNOW TO CONTINUE OVER
NWRN WISC THROUGH MID MORNING WHILE DECREASING OVER MN ZONES. COND
PRESS DEFICITS SUGGEST MOSTLY CLOUDY CONDITIONS OVER MN THRU 18Z
WITH CLEARING FROM WEST TO EAST IN THE AFTN. MOMENTUM TRANSFER
WILL INCREASE WITH CLOUDS DIMINISHING SO EXPECT A PERIOD OF GUSTY
NW WINDS DEVELOPING. LOW LEVEL THERMAL FIELDS DO NOT SUPPORT
SIGNIFICANT LAKE INDUCED INSTABILITY. HOWEVER SYNOPTIC SCALE ASCENT
COMBINED WITH TERRAIN LIFT SHOULD ALLOW SOME 1 TO 2 INCH ACCUMULATION
OVER GOGEBIC RANGE THIS MORNING. SNOW SHOULD DIMINISH BY 21Z OVER
ERN WISC SNOWBELT. CLOUDS AND LOW LVL COLD ADVECTION SHOULD KEEP
TEMP CLIMB TO A MINIMUM OVER ERN CWA TODAY. MILDEST READINGS
EXPECTED ACROSS SWRN CWA WITH MORE SUNSHINE.
TONIGHT/TOMORROW...MID LVL RIDGE MOVES ACROSS CWA TONIGHT WITH
WARM ADVECTION REGIME INCREASING IN STRENGTH. USED BC TEMPS
CONSIDERING ANOMALOUS PATTERN AND LIMITED SNOW COVER. MAY STILL
NEED TO ADJUSTING MIN TEMPS UPWARDS. SHOULD SEE A SHIELD OF
MID/HIGH CLOUDS TRAVERS FROM WEST TO EAST DURING THE DAY MONDAY.
MAX TEMPS MAY REACH 15 TO 20 DEGREES ABOVE NORMS. INTENSE SFC LOW
WILL SWEEP ACROSS SRN MAN INTO SCTRL ONTARIO BY 0Z TUE. WILL HOLD
OFF ON PRECIP FOR NOW BUT LATEST SREF/GEM INDICATE
EXTENDED....MONDAY NIGHT THROUGH SATURDAY
TEMPERATURES WILL RAPIDLY FALL MON NIGHT/TUES AS THE TROUGH DEPARTS
TO THE EAST AND WINDS TURN OUT OF THE NW. LATEST NAM/ECM/GFS
CONTINUE TO SHOW AGREEMENT THAT H85 READINGS FALL ON THE ORDER OF
10C FROM 00Z THROUGH 12Z TUESDAY. THE CYCLONIC FLOW WILL KEEP SMALL
CHC FOR LINGERING -SHSN ACROSS THE NRN/ERN ZONES THROUGH TUES. A FAST
MOVING SFC RIDGE WILL PASS OVER THE REGION TUES AFTRN/EVENING BEFORE
WINDS INCREASE OUT OF THE SOUTH LATE TUES NIGHT AHEAD OF APPROACHING
WAVE DROPPING SE OUT OF MANITOBA. TIMING OF THE RIDGE PASSING WILL
HAVE SIGNIFICANT EFFECT ON OVERNIGHT LOWS TUES NIGHT WITH CLEARING
AND LIGHT WINDS ASSOCIATED WITH THE RIDGE POTENTIALLY DROPPING THE
TEMPS INTO THE SINGLE DIGITS IN THE NE ZONES...THEN RISING LATE WITH
THE RETURN FLOW.
LONG TERM MODELS BEGIN TO HAVE LARGE DIFFERENCES PAST DAY 4. HAVE
CHC POPS AT THE END OF THE WEEK WITH SOME CONTINUITY THAT A FAST
MOVING WAVE TRANSLATES OVER THE REGION. HOWEVER...THE STRENGTH AND
TIMING OF THIS SYSTEM AND POTENTIAL FOR ANY SNOW ACCUM REMAIN
HIGHLY UNCERTAIN.
&&
.POINT TEMPS/POPS...
DLH 34 23 38 24 / 20 0 0 10
INL 33 22 37 16 / 20 0 10 20
BRD 37 25 42 23 / 10 0 0 0
HYR 34 20 39 24 / 20 0 0 10
ASX 34 23 40 28 / 40 0 0 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...NONE.
WI...NONE.
LS...SMALL CRAFT ADVISORY UNTIL 4 PM CST THIS AFTERNOON FOR LSZ146-
147.
&&
$$
SHORT TERM...GROCHOCINSKI
AREA FORECAST DISCUSSION
NWS BUFFALO NY
327 PM EST SUN DEC 25 2011
.SYNOPSIS...
LOW PRESSURE WILL QUICKLY PASS TO THE NORTH OVERNIGHT...BRINGING A
PERIOD OF RAIN OR SNOW SHOWERS...WHICH WILL TRANSITION TO SNOW
SHOWERS AS COLDER AIR WORKS IN LATER TONIGHT. THIS SHOULD NOT BRING
MUCH ACCUMULATION TO MOST...EXCEPT FOR HIGHER TERRAIN IN THE
SOUTHERN TIER...AND EAST OF LAKE ONTARIO...WHERE A FEW INCHES OF
SNOW ARE POSSIBLE. ANY LINGERING SNOW SHOWERS WILL QUICKLY END
MONDAY AS HIGH PRESSURE BUILDS INTO THE LOWER LAKES. LOW PRESSURE
TRACKING ACROSS NEW ENGLAND WILL BRING RAIN...WHICH WILL TRANSITION
TO SNOW TUESDAY NIGHT.
&&
.NEAR TERM /THROUGH MONDAY/...
THROUGH THE REMAINDER OF THE AFTERNOON...GUSTY WINDS WILL CONTINUE
ON THE NIAGARA FRONTIER...WITH GUSTS UP TO 40 MPH. AS WINDS SHIFT
MORE SW IN RESPONSE TO THE APPROACHING SHORTWAVE...WINDS WILL PICK
UP FURTHER TO THE EAST...WITH GUSTS TO 30 MPH BECOMING MORE
COMMONPLACE TOWARD THIS EVENING. TEMPERATURES ARE QUITE A BIT ABOVE
NORMAL IN WESTERN NEW YORK...WITH MOST LOCATIONS WELL INTO THE 40S.
AFTER THIS...EYES TURN TO AN APPROACHING SHORTWAVE...WHICH WILL
CROSS THE REGION TONIGHT...EVENTUALLY USHERING COLDER AIR INTO THE
REGION. WHILE FAIRLY POTENT...THE SHORTWAVE IS FAIRLY MOISTURE
STARVED...DEPENDING ON MOST OF ITS MOISTURE FROM THE LAKES. MODEL
GUIDANCE IS IN FAIRLY GOOD AGREEMENT...WITH THE CAUSE OF
PRECIPITATION A COMBINATION BETWEEN MODEST LEVELS OF LAKE INDUCED
STABILITY COMBINED WITH THE SHORTWAVE. THE HRRR BASICALLY IS
PAINTING A SHARPER PICTURE OF THE NAM/RGEM SOLUTIONS. THIS PROVIDES
RATHER GOOD CONFIDENCE IN THE GENERAL IDEA OF RAIN AND SHOWERS
MOVING ACROSS THE REGION THIS EVENING...THEN LINGERING LAKE EFFECT
SNOW SHOWERS LATE TONIGHT SSE OF THE LAKES.
FOR MOST...THIS WILL PROBABLY BRING LITTLE...IF ANY...ACCUMULATING
SNOWFALL. THE NAM12/RGEM/HRRR ALL FORECAST MEAGER QPF (MEAN OF THE
MODELS HAS ABOUT 0.05 INCHES) IN THE BUFFALO/ROCHESTER METRO AREAS...AS
MUCH OF THE MOISTURE WILL THE SHORTWAVE PICKS UP WILL BE TOO LATE
FOR THESE LOCATIONS. FOR THE CITIES...EXPECT RAIN OR SNOW SHOWERS
FROM AROUND SUNSET THROUGH LATE THIS EVENING...THEN POSSIBLY A
LINGERING SNOW SHOWER OVERNIGHT.
THINGS ARE MORE INTERESTING EAST OF LAKE ONTARIO...WHERE IT IS
CLOSEST TO THE SHORTWAVE...AND IN BEING DOWNSTREAM OF BOTH LAKES IT
WILL HAVE THE BEST OPPORTUNITY TO PICK UP MOISTURE. BOTH 00Z AND
12Z MODEL RUNS...AS WELL AS THE HRRR...DEVELOP A DECENT BAND OUT
AHEAD OF THE SHORTWAVE...WHICH SHOULD DROP ACROSS THE EASTERN LAKE
ONTARIO REGION THIS EVENING. ALONG THE LAKE SHORE...THIS WILL
PROBABLY MAINLY BE A MIX OF RAIN AND SNOW...WHILE HIGHER ELEVATIONS
(INCLUDING THE TUG HILL AND NORTHERN LEWIS COUNTY) SHOULD BE MAINLY
SNOW. BASICALLY EXPECT 3 TO 5 INCHES OF SNOW ACROSS THE HIGHER
TERRAIN IN LEWIS AND OSWEGO COUNTIES...AND WHILE CONFIDENCE IS
MARGINAL FOR AN ADVISORY...WILL ISSUE ONE GIVEN THAT THE SNOW THAT
DOES FALL SHOULD BE MODERATE TO HEAVY...WITH MOST FALLING IN A FEW
HOURS AS THE SHORTWAVE CROSSES.
DON/T EXPECT QUITE AS MUCH SNOW EAST OF LAKE ERIE...AS IT WILL BE
FURTHER FROM THE SHORTWAVE...AND DOES NOT HAVE MUCH MOISTURE TO TAP
INTO. STILL...THERE SHOULD BE SOME OROGRAPHIC ENHANCEMENT ON THE
CHAUTAUQUA...WITH 2 TO 3 INCHES LIKELY ACROSS HIGHER TERRAIN...ONCE
A MIX OF RAIN AND SNOW SHOWERS CHANGES OVER TO SNOW SHOWERS AS
COLDER AIR FILTERS IN DURING THE EVENING HOURS.
THE SHORTWAVE WILL EXIT EAST LATE TONIGHT...WITH SNOW SHOWERS
TAPERING OFF IN MOST LOCATIONS. THE NW FLOW SHOULD SUPPORT LIGHT
LAKE EFFECT SNOW SHOWERS TO LINGER SE OF LAKE ONTARIO...FOCUSED ON
WAYNE/CAYUGA AND POSSIBLY PORTIONS OF MONROE AND OSWEGO COUNTIES
THROUGH EARLY MONDAY MORNING. THIS MAY PRODUCE AN INCH OR TWO.
FOR MONDAY...HIGH PRESSURE WILL RIDGE NORTH FROM THE APPALACHIANS.
WHILE THE DAY SHOULD START OFF WITH A FAIR AMOUNT OF LINGERING
CLOUDS...SKIES SHOULD GRADUALLY CLEAR ACROSS WESTERN NEW YORK. WHILE
COOLER...HIGHS WILL STILL BE ABOVE NORMAL...AS SHOT OF COLD AIR IS
QUITE NARROW. BY THE AFTERNOON HOURS...850 MB TEMPERATURES WILL
ALREADY BE WARMING...AS THE UPPER LEVEL RIDGE AXIS APPROACHES. HIGHS
SHOULD MAINLY BE IN THE UPPER 30S ACROSS WESTERN NEW YORK...IN THE
LOWER 30S EAST OF LAKE ONTARIO.
&&
.SHORT TERM /MONDAY NIGHT THROUGH THURSDAY NIGHT/...
THE HIGH PRESSURE RIDGE WILL SLIDE OFF THE EAST COAST MONDAY
NIGHT. CLEAR SKIES WILL HAVE AN INCREASE IN CLOUDINESS LATE IN THE
NIGHT. RADIATIONAL COOLING EARLY IN THE NIGHT WILL LOWER THE TEMPS
TO THEIR LOWS IN THE UPPER 20S TO LOWER 30S...THEN STRONGER
SOUTHERLY WINDS WILL RAISE THE TEMPS FROM THE LATE OVERNIGHT HOURS
TO DAYBREAK.
ON TUESDAY...ECMWF AND GFS ARE COMING CLOSER TO A COMMON SOLUTION
WITH RESPECT TO THE MERGER OF AN OPING CLOSED LOW IN THE SOUTHERN
STREAM PHASING WITH AN BEING ABSORBED BY A DIGGING OPEN WAVE IN THE
NORTHERN STREAM. THE PHASING OF THE SYSTEMS WILL PRODUCING A FULL
LATITUDE TROUGH FROM THE LOWER MISSISSIPPI VALLEY NORTH TO HUDSON
BAY WITH A SURFACE LOW FORMING JUST SOUTH OF THE LOWER OHIO VALLEY.
THE WARM AND MOIST INFLUX TO THE EAST OF THIS TROUGH AND SURFACE LOW
WILL YIELD A WET PRECIP PATTERN FOR MUCH OF THE DAYLIGHT HOURS OF
TUESDAY. 850MB TEMPS AT 12Z TUESDAY RANGE FROM +4C TO +6C...BUT WILL
COOL RAPIDLY DURING THE AFTERNOON AS THE SURFACE LOW MOVES FROM
SOUTH OF THE OHIO VALLEY TO THE UPPER CHESAPEAKE BAY BY THE EVENING.
PRECIP WILL START AS RAIN BUT MIX WITH WET SNOW AS THE 0C ISOTHERM
MOVES EASTWARD...THE -2C ISOTHERM DURING THE AFTERNOON AND -6C BY
EVENING.
AS THE SURFACE LOW LIFTS FURTHER NORTHEAST ALONG THE NEW ENGLAND
COAST TUESDAY NIGHT...COLD ADVECTION ON ITS BACKSIDE WILL INCREASE.
THIS WILL DELIVER A PROGRESSIVELY COLDER AIRMASS INTO OUR
REGION...RESULTING IN ANY PRECIP CHANGING OVER FROM RAIN TO ALL
SNOW. THE ISSUE OF THE STRENGTH OF THE PHASING OF NORTHERN AND
SOUTHERN BRANCH TROUGHS WILL ALSO LIMIT THE STRENGTH OF THE SNOW
ALONG THE WESTERN EDGE OF THIS SYSTEM AS IT EXITS THE REGION. WHERE
THERE HAD BEEN GREATER DIFFERENCES AND DISCREPANCIES AMONG THE
VARIOUS MODELS...THE 12Z RUNS OF GFS/ECMWF/GEM/NAM ARE ALL SHOWING A
WELL DEFINED UPPER TROUGH OF RESPECTABLE MERIDIONAL AMPLITUDE BUT DO
DIFFER ON THE DEVELOPMENT AND TRACK OF THE SURFACE LOWS...BUT ALL
SFC LOWS WILL BE EAST OF OUR FORECAST AREA WITH A TRAILING COLD
DEFORMATION ZONE CAPABLE OF PRODUCING A MEASURABLE SNOWFALL. I WILL
KEEP WITH THE GFS/ECMWF SOLUTION AND EXPECT THERE TO BE A FAIR
AMOUNT OF SNOW OVER THE CENTRAL AND NORTHERN PORTIONS OF THE
STATE...FROM THE FINGER LAKES TO THE EASTERN LAKE ONTARIO REGION AND
TUG HILL FOR OUR AREA OF CONCERN.
WEDNESDAY SHOULD THEN FEATURE A GENERAL REPEAT OF MONDAY...AS THE
COMBINATION OF INCREASING RIDGING/DRYING/SUBSIDENCE HELPS TO SHUT
DOWN ANY LINGERING LAKE EFFECT DURING THE MORNING...AS WELL AS BRING
A RETURN OF AT LEAST SOME PARTIAL SUNSHINE. WITH A MUCH COLDER
AIRMASS IN PLACE /850 TEMPS RANGING FROM -12C TO -14C/...DAYTIME
HIGHS WILL BE MUCH COLDER THAN TUESDAY`S...WITH READINGS RANGING
GENERALLY IN THE MID 20S WITH TEENS FOR THE NORTH COUNTRY. CONTINUED
DRY AND COLD WEATHER WILL THEN FOLLOW FOR WEDNESDAY NIGHT AS RIDGING
CRESTS OVERHEAD AT ALL LEVELS...EXPECT TEMPS IN THE TEENS TO LOW 20S
WITH SINGLE NUMBERS EAST OF LAKE ONTARIO.
HIGH PRESSURE OVER THE REGION ON THURSDAY WILL MAINTAIN DRY
WEATHER...WITH SOUTHERN FLOW DURING THE AFTERNOON BOOSTING TEMPS
BACK ABOVE SEASONAL NORMALS IN THE MID TO UPPER 30S EXCEPT UPPER 20S
TO LOW 30S EAST OF LAKE ONTARIO.
&&
.LONG TERM /FRIDAY THROUGH SUNDAY/...
IN THE EXTENDED PORTION OF THE FORECAST...BOUNDARY LAYER TEMPS
WILL BECOME COLD ENOUGH THAT MOST PRECIP WILL BE IN THE FORM OF
SNOW. THE EXCEPTION WILL BE ON FRIDAY AND ONLY DURING THE MIDDAY
ARE TEMPS SUFFICIENTLY MILD ENOUGH FOR PRECIP TO BE RAIN OR A MIX
OF RAIN AND SNOW. THERE WILL BE A CHANCE OF PRECIP EACH DAY DURING
THE END OF THE WEEK AND THE WEEKEND AS UPPER WAVES MOVE ACROSS THE
REGION.
&&
.AVIATION /21Z SUNDAY THROUGH FRIDAY/...
18Z TAFS...EXPECT LARGELY VFR CONDITIONS TO PERSIST ACROSS THE
REGION THROUGH THE AFTERNOON HOURS...THOUGH CIGS NEAR 3000 AT ART
MAY RESULT IN BRIEF PERIODS OF MVFR CONDITIONS.
AN UPPER LEVEL TROF AND ASSOCIATED COLD FRONT WILL CROSS THE
REGION THIS EVENING. THIS WILL BRING A PERIOD OF SHOWERS...WHICH
WILL START AS RAIN OR RAIN AND SNOW MIXED INITIALLY...BUT SHOULD
TREND TOWARD SNOW AS COLDER AIR FILTERS IN LATER THIS EVENING.
EXPECT CONDITIONS TO INITIALLY BE SLOW TO LOWER...WITH LOWERING
CIGS AND PERIODS OF LOWER VSBY BEHIND THE TROF LATE EVENING AND
OVERNIGHT. CONDITIONS SHOULD LARGELY BE MVFR...WITH PERIODS OF IFR
OR LOWER IN MORE PERSISTENT SNOW SHOWERS. JHW/ART...WOULD BE MOST
PRONE TO THESE LOWER CONDITIONS.
CONDITIONS SHOULD IMPROVE MONDAY...AS CIGS LIFT AND
SCATTER...THOUGH TIMING OF WHAT WILL LIKELY BE AN ABRUPT CLEARING
IS ALWAYS TRICKY TO TIME. BY AFTERNOON...EXPECT ALL SITES TO BE VFR.
OUTLOOK...
MONDAY NIGHT...VFR.
TUESDAY AND TUESDAY NIGHT...MVFR IN RAIN SHOWERS CHANGING TO SNOW
SHOWERS TUESDAY NIGHT. POSSIBLY LOWER AT ART IN STEADIER SNOW.
WEDNESDAY AND THURSDAY...MAINLY VFR.
FRIDAY...VFR/MVFR. A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
THROUGH MID-AFTERNOON...THE SSW FLOW HAS NOT PRODUCED VERY STRONG
WINDS ON MOST OF THE NEAR SHORE WATERS...AS TEMPERATURES HAVE
WARMED...AND LAND HAS HELPED SHIELD THE WATERS FROM STRONGER GUSTS.
WINDS HAVE BEEN MUCH STRONGER ON THE NORTH SHORES...AND ARE LIKELY
STRONGER THAN OBSERVATIONS ON THE SOUTH SHORES ARE SHOWING...JUST A
FEW MILES OFFSHORE. THIS WILL CHANGE LATER THIS AFTERNOON...AS THE
APPROACHING SHORTWAVE CAUSES WINDS TO SHIFT MORE SW AND WSW. THIS
WILL CAUSE THE CHAUTAUQUA RIDGE TO HELP FUNNEL WINDS...RESULTING IN
BETTER MIXING AND STRONGER SUSTAINED WINDS ALONG THE LAKE ERIE
SHORELINE.
FOR TONIGHT...WINDS WILL SHIFT TO THE NW BEHIND THE SHORTWAVE...AND
WHILE WINDS ALOFT WILL WEAKEN...MIXING WILL IMPROVE WHICH WILL CAUSE
WINDS TO MAINTAIN A DECENT FLOW OVERNIGHT. A NARROW RIDGE OF HIGH
PRESSURE WILL BUILD ACROSS THE WATERS MONDAY...ALLOWING A BRIEF
PERIOD OF CALMER WATERS BEFORE THE NEXT SYSTEM APPROACHES MONDAY
NIGHT.
A FAIRLY EXTENDED PERIOD OF SMALL CRAFT ADVISORY CONDITIONS ARE
LIKELY THROUGH MID WEEK...AS LOW PRESSURE DEVELOPS AND TRACKS INTO
NEW ENGLAND TUESDAY NIGHT. THIS SHOULD MAINTAIN A DECENT FLOW ACROSS
THE WATERS...UNTIL HIGH PRESSURE FINALLY BUILDS IN FOR THE LATTER
HALF OF THE WEEK.
&&
.BUF WATCHES/WARNINGS/ADVISORIES...
NY...LAKE EFFECT SNOW ADVISORY FROM 7 PM THIS EVENING TO 7 AM EST
MONDAY FOR NYZ006-008.
MARINE...SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL MIDNIGHT EST TONIGHT FOR
LOZ030.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR LOZ043>045.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR LOZ042.
&&
$$
SYNOPSIS...APFFEL
NEAR TERM...APFFEL
SHORT TERM...WCH
LONG TERM...WCH
AVIATION...APFFEL
MARINE...APFFEL/WCH
AREA FORECAST DISCUSSION
NWS BUFFALO NY
113 PM EST SUN DEC 25 2011
.SYNOPSIS...
IT WILL BE A RATHER WINDY AND MILD CHRISTMAS DAY WITH A MIX OF
CLOUDS AND A LITTLE SUNSHINE FOR MOST OF THE DAY. A COLD FRONT AND
UPPER LEVEL DISTURBANCE WILL CROSS THE REGION LATE THIS AFTERNOON
AND THIS EVENING WITH A ROUND OF LIGHT SNOW SHOWERS FOR MUCH OF THE
REGION BRIEFLY BEGINNING AS RAIN. ACCUMULATIONS WILL BE VERY LIMITED
EXCEPT ACROSS THE HIGHER TERRAIN OF THE WESTERN SOUTHERN TIER AND
TUG HILL REGION WHERE SEVERAL INCHES OF SNOW IS POSSIBLE. ANY
LINGERING SNOW SHOWERS WILL QUICKLY END MONDAY AS HIGH PRESSURE
BUILDS INTO THE LOWER LAKES. LOW PRESSURE WILL BRING MORE UNSETTLED
WEATHER TUESDAY WITH SOME LIGHT RAIN ENDING AS A BRIEF PERIOD OF
LIGHT SNOW TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WHILE EARLY MORNING CLOUDS HAVE LARGELY GIVEN WAY TO AT LEAST SOME
SUNSHINE...A FEW SNOW SHOWERS OR FLURRIES HAVE DEVELOPED EAT OF
LAKE ONTARIO. THESE WILL BE SHORT LIVED AS THEY RACE OFF TO THE
EAST...BUT A DUSTING IS POSSIBLE ACROSS HIGHER ELEVATIONS OF LEWIS COUNTY.
BY LATE THIS AFTERNOON A STRONG SHORTWAVE WILL BE ON OUR DOORSTEP.
LARGE SCALE FORCING FOR ASCENT WILL QUICKLY INCREASE AFTER 21Z AS
STRONG DPVA AND HEIGHT FALLS OVERSPREAD THE LOWER LAKES. THE NEW
12Z NAM AND HRRR ARE A TAD SLOWER (AN HOUR OR TWO) WITH THE START
OF THE SHOWERS. EXPECT SCATTERED SHOWERS TO DEVELOP AROUND SUNSET
ACROSS WESTERN NY AND THE NORTH COUNTRY THEN QUICKLY SPREAD ACROSS
THE REMAINDER OF THE REGION THROUGH EARLY EVENING. THIS SHOULD
KEEP THE VAST MAJORITY OF THE DAYLIT HOURS DRY ACROSS WESTERN NEW
YORK.
NAM/GFS BUFKIT PROFILES SHOW THE BOUNDARY LAYER INITIALLY WARM
ENOUGH FOR MUCH OF THIS TO BE RAIN AT THE START...BUT COLD AIR
ADVECTION AND EVAPORATE COOLING WILL QUICKLY CHANGE THE RAIN
OVER TO SNOW BY MID TO LATE EVENING.
THIS SYSTEM IS FAST MOVING AND RELATIVELY MOISTURE STARVED...SO THIS
WILL GREATLY LIMIT ACCUMULATIONS IN MOST AREAS ESPECIALLY
CONSIDERING THE MILD START AT THE ONSET OF PRECIP. THE MAJORITY OF
THE LOWER ELEVATIONS ACROSS THE REGION WILL SEE LESS THAN AN
INCH...AND PERHAPS NOTHING AT ALL IN SOME AREAS CLOSE TO THE
LAKESHORES. THERE WILL BE TWO NOTABLE EXCEPTIONS TO THIS HOWEVER...
EAST OF LAKE ONTARIO BUFKIT PROFILES AND MESOSCALE MODEL DATA BOTH
SUPPORT A SHORT WINDOW OF SEVERAL HOURS FROM MID TO LATE EVENING
WHERE CONDITIONS BECOME FAVORABLE FOR LAKE ENHANCEMENT NEAR THE TIME
OF THE COLD FRONTAL PASSAGE. NAM BUFKIT PROFILES BRING LAKE INDUCED
EQUILIBRIUM LEVELS ALL THE WAY UP TO 15K FEET FOR A FEW HOURS WITH
WELL ALIGNED WESTERLY FLOW. THIS SHOULD SET THE STAGE FOR LAKE
ENHANCEMENT AT THE EAST END OF THE LAKE...MAXIMIZED ACROSS THE TUG
HILL IN THE FAVORED UPSLOPE AREAS. THE SNOW COULD BECOME QUITE HEAVY
FOR A BRIEF PERIOD OF TIME...BUT THE SHORT DURATION WILL PREVENT ANY
BIG ACCUMULATIONS. HAVE GONE WITH 3-4 INCHES ACROSS THE TUG HILL
REGION FOR TONIGHT. HELD OFF ON ADVISORY FOR NOW GIVEN THE MARGINAL
SNOW NUMBERS AND THE FACT THAT THE GREATER ACCUMULATIONS WILL BE
LIMITED TO A SMALL AREA ACROSS HIGHER TERRAIN...BUT DAY SHIFT MAY
NEED TO CONSIDER A HEADLINE. ACROSS LOWER ELEVATIONS MARGINAL
BOUNDARY LAYER TEMPS WILL GREATLY LIMIT ACCUMULATIONS...ESPECIALLY
CLOSER TO THE LAKE ONTARIO SHORE WHERE VERY LITTLE ACCUMULATION IS
EXPECTED.
AFTER MIDNIGHT THE LAKE ENHANCEMENT WILL EVOLVE INTO PURE LAKE
EFFECT BUT QUICKLY MOVE TO SOUTHEAST OF THE LAKE AS THE BOUNDARY
LAYER FLOW BECOMES NORTHWEST. THIS WILL SET UP RELATIVELY WEAK SNOW
SHOWERS FROM NEAR ROCHESTER OVER TO OSWEGO COUNTY AND DOWN INTO THE
FINGER LAKES. MAY SEE SOME SPOTTY ONE INCH AMOUNTS FROM
THIS...ESPECIALLY FROM THE EASTERN SUBURBS OF ROCHESTER INTO WAYNE
COUNTY. QUICK DRYING OF THE SYNOPTIC BACKGROUND AND VERY MARGINAL
INSTABILITY AFTER MIDNIGHT WILL PREVENT ANYTHING MORE SIGNIFICANT.
THE OTHER AREA OF CONCERN IS ACROSS THE CHAUTAUQUA RIDGE. NAM BUFKIT
PROFILES SUGGEST A WINDOW FROM ABOUT 03Z-09Z WHERE NORTHWEST UPSLOPE
FLOW AND MODEST LAKE ENHANCEMENT WILL BECOME FAVORABLE FOR MINOR
ACCUMULATIONS IN THE TYPICAL AREAS ALONG THE RIDGE LINE FROM SHERMAN
UP THROUGH MAYVILLE TO PERRYSBURG. AGAIN THE QUICK DRYING OUT OF THE
SYNOPTIC MOISTURE AND SHORT FETCH/LIMITED INSTABILITY WILL PREVENT
ANY SIGNIFICANT ACCUMULATIONS...BUT MAY SEE 2-4 INCH AMOUNTS IN SOME
AREAS. MAY ALSO SEE 1-2 INCH AMOUNTS FARTHER NORTH ACROSS THE BOSTON
HILLS AND WYOMING COUNTY...ALTHOUGH THE FLOW QUICKLY ESTABLISHES TOO
MUCH NORTHERLY COMPONENT FOR MUCH LAKE ENHANCEMENT IN THOSE AREAS.
ALL OF THIS SHOULD BE ON THE WANE BEFORE DAYBREAK MONDAY AS A RIDGE
OF HIGH PRESSURE BUILDS TOWARDS LAKE ERIE AND MOISTURE QUICKLY
DECREASES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
FOLLOWING THE PASSAGE OF TODAY`S SYSTEM...STRONG RIDGING WILL BUILD
ACROSS THE AREA AT ALL LEVELS ON MONDAY. ASSOCIATED STRONG DRYING
AND SUBSIDENCE WILL BRING A QUICK END TO ANY LINGERING LAKE EFFECT
SNOW SHOWERS SOUTHEAST OF LAKE ONTARIO IN THE MORNING...ALONG WITH
THE RETURN OF A DECENT AMOUNT OF SUNSHINE. WITH A SEASONABLY COLDER
AIRMASS IN PLACE...DAYTIME TEMPS WILL BE CLOSER TO NORMAL FOR LATE
DECEMBER...OR IN THE LOWER TO MID 30S.
DURING MONDAY NIGHT...THE AFOREMENTIONED RIDGE WILL SLIDE OFF THE
EAST COAST...ALLOWING A PAIR OF SHORTWAVE TROUGHS...ONE IN THE
NORTHERN STREAM AND ONE IN THE SOUTHERN STREAM...TO APPROACH THE
AREA FROM THE NATION`S MIDSECTION. IN ADVANCE OF THESE FEATURES...A
DEEP SOUTHWESTERLY FLOW OF MILDER AIR WILL OVERSPREAD THE AREA...
WITH THE RESULTING WARM AIR ADVECTION LEADING TO BOTH AN INCREASE IN
CLOUD COVER AND A NON-DIURNAL TEMPERATURE TREND...WITH TEMPS
STEADILY RISING AFTER EARLY EVENING LOWS IN THE MID 20S TO LOWER
30S. WITH THE NAM/GFS/GEM AND ECMWF NOW ALL IN GOOD AGREEMENT THAT
ANY PRECIP WILL REMAIN SAFELY WEST OF THE AREA THROUGH THE
NIGHT...HAVE PULLED ANY MENTION OF PRECIP FROM LATE MONDAY NIGHT.
ON TUESDAY...THE AFOREMENTIONED PAIR OF TROUGHS WILL CONTINUE TO
ADVANCE ON THE REGION FROM THE WEST...WITH THE VARIOUS GUIDANCE
PACKAGES CONTINUING TO SHOW DISPARITIES WITH RESPECT TO EXACTLY HOW
MUCH THESE FEATURES PHASE TOGETHER AS THEY APPROACH. AT THIS
TIME...THE SPREAD IN THE GUIDANCE CURRENTLY RANGES FROM THE UNPHASED
00Z NAM/GFS/GEM SOLUTIONS TO THE 00Z ECMWF...WHICH SHOWS THE TWO
WAVES MERGING INTO A RATHER SHARP FULL LATITUDE TROUGH. REGARDLESS
OF WHICH OF THESE SCENARIOS YOU BELIEVE...ALL GENERALLY DEPICT A
DEVELOPING LOW PRESSURE SYSTEM QUICKLY LIFTING NORTHEAST FROM THE
TENNESSEE VALLEY TO THE MID ATLANTIC STATES ON TUESDAY...WITH AN
ASSOCIATED RIBBON OF MOISTURE AND LIFT SPREADING NORTHEAST ACROSS
OUR REGION. THIS SHOULD RESULT IN A LIKELIHOOD OF PRECIP SPREADING
NORTHEAST ACROSS THE REGION DURING THE DAY. AS FOR PTYPE...EXPECTED
MILD BOUNDARY LAYER TEMPS IN THE 40S AND 850 MB TEMPS OF ZERO TO -4C
SHOULD BE SUPPORTIVE OF MAINLY RAIN RIGHT THROUGH THE DAY...WITH
PERHAPS A LITTLE SNOW MIXING IN LATE AS THE COLUMN BEGINS TO COOL A
BIT MORE STRONGLY.
AS THE SURFACE LOW LIFTS FURTHER NORTHEAST ALONG THE NEW ENGLAND
COAST TUESDAY NIGHT...COLD ADVECTION ON ITS BACKSIDE WILL INCREASE.
THIS WILL DELIVER A PROGRESSIVELY COLDER AIRMASS INTO OUR
REGION...RESULTING IN ANY PRECIP CHANGING OVER FROM RAIN TO ALL
SNOW. THE MAIN ISSUE DURING THIS TIME FRAME WILL BE HOW QUICKLY THE
PRECIP TAPERS OFF...WHICH WILL DIRECTLY INFLUENCE POTENTIAL SNOWFALL
ACCUMULATIONS AND WILL BE A DIRECT FUNCTION OF EXACTLY MUCH PHASING
OF THE NORTHERN AND SOUTHERN STREAMS OCCURS. THE FULLY PHASED ECMWF
SOLUTION WOULD SUPPORT A STRONGER AND SLOWER MOVING SURFACE LOW ON A
MORE WESTERLY TRACK...AND WOULD DELIVER COLDER AIR MORE STRONGLY
WHILE ALSO MAINTAINING PRECIP ACROSS THE AREA LONGER...THEREBY
RESULTING IN WHAT WOULD BE A WIDESPREAD ACCUMULATING SNOW. IN
CONTRAST...THE LESS PHASED NAM/GFS/GEM SOLUTIONS OFFER WEAKER
COLD ADVECTION AND A MUCH QUICKER END TO THE SYNOPTIC-SCALE
PRECIP...RESULTING IN MUCH MORE LIMITED ACCUMULATIONS AFTER THE
CHANGEOVER.
WITH HPC PREFERENCES CURRENTLY TOWARD A FASTER...MORE NON-PHASED
SOLUTION LED BY THE CANADIAN GEM...FOR NOW WILL ELECT TO GO WITH A
FASTER END TO THE MAIN SWATH OF SYNOPTIC SCALE PRECIP TUESDAY
NIGHT...WITH LAKE-DRIVEN SNOW SHOWERS TAKING OVER AS A NORTHERLY
FLOW OF PROGRESSIVELY COLDER AIR SPREADS ACROSS THE AREA OVERNIGHT.
THIS SHOULD STILL RESULT IN AT LEAST SOME LIMITED ACCUMULATIONS IN
MANY AREAS BY MORNING...THOUGH THE SHORT NORTHERLY FETCH AND
INCREASINGLY DRY AIRMASS SHOULD KEEP THESE FROM GETTING OUT OF HAND.
WEDNESDAY SHOULD THEN FEATURE A GENERAL REPEAT OF MONDAY...AS THE
COMBINATION OF INCREASING RIDGING/DRYING/SUBSIDENCE HELPS TO SHUT
DOWN ANY LINGERING LAKE EFFECT DURING THE MORNING...AS WELL AS BRING
A RETURN TO AT LEAST SOME PARTIAL SUNSHINE. WITH A MUCH COLDER
AIRMASS IN PLACE /850 TEMPS AVERAGING AROUND -10C/...DAYTIME HIGHS
WILL BE MUCH COLDER THAN TUESDAY`S...WITH READINGS RANGING FROM THE
MID 20S ACROSS THE NORTH COUNTRY TO AROUND 30 ELSEWHERE. CONTINUED
DRY BUT SEASONABLY CHILLY WEATHER WILL THEN FOLLOW FOR WEDNESDAY
NIGHT AS RIDGING CRESTS OVERHEAD AT ALL LEVELS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
IN THE EXTENDED PORTION OF THE FORECAST...SLOWLY DEPARTING SURFACE
RIDGING IS EXPECTED TO KEEP A CONTINUATION OF MAINLY DRY WEATHER
ACROSS OUR REGION THROUGH THURSDAY. THEREAFTER...ONE OR MORE WAVES
OF LOW PRESSURE ZIPPING ALONG IN A PERSISTENT FAST ZONAL FLOW WILL
BRING RENEWED PRECIP CHANCES FOR BOTH FRIDAY AND NEW YEAR`S EVE.
AS IS USUALLY THE CASE IN SUCH A PATTERN...THE MEDIUM RANGE GUIDANCE
CONTINUES TO HAVE TROUBLE COMING INTO CONVERGENCE ON THE TIMING AND
EXACT POSITIONING OF SUCH SYSTEMS...SO BROADBRUSH CHANCE POPS WILL
REMAIN IN ORDER FOR THE END OF THE WEEK. WITH THE PREVAILING ZONAL
FLOW...SOME MODERATION IN TEMPS FROM WEDNESDAY`S COLDER READINGS
SHOULD DEVELOP...WHICH SHOULD BE SUPPORTIVE OF A RAIN/SNOW SHOWER
MIX DEPENDING UPON THE TIME OF DAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
18Z TAFS...EXPECT LARGELY VFR CONDITIONS TO PERSIST ACROSS THE
REGION THROUGH THE AFTERNOON HOURS...THOUGH CIGS NEAR 3000 AT ART
MAY RESULT IN BRIEF PERIODS OF MVFR CONDITIONS.
AN UPPER LEVEL TROF AND ASSOCIATED COLD FRONT WILL CROSS THE
REGION THIS EVENING. THIS WILL BRING A PERIOD OF SHOWERS...WHICH
WILL START AS RAIN OR RAIN AND SNOW MIXED INITIALLY...BUT SHOULD
TREND TOWARD SNOW AS COLDER AIR FILTERS IN LATER THIS EVENING.
EXPECT CONDITIONS TO INITIALLY BE SLOW TO LOWER...WITH LOWERING
CIGS AND PERIODS OF LOWER VSBY BEHIND THE TROF LATE EVENING AND
OVERNIGHT. CONDITIONS SHOULD LARGELY BE MVFR...WITH PERIODS OF IFR
OR LOWER IN MORE PERSISTENT SNOW SHOWERS. JHW/ART...WOULD BE MOST
PRONE TO THESE LOWER CONDITIONS.
CONDITIONS SHOULD IMPROVE MONDAY...AS CIGS LIFT AND
SCATTER...THOUGH TIMING OF WHAT WILL LIKELY BE AN ABRUPT CLEARING
IS ALWAYS TRICKY TO TIME. BY AFTERNOON...EXPECT ALL SITES TO BE VFR.
OUTLOOK...
MONDAY NIGHT...VFR.
TUESDAY AND TUESDAY NIGHT...MVFR IN RAIN SHOWERS CHANGING TO SNOW
SHOWERS TUESDAY NIGHT. POSSIBLY LOWER AT ART IN STEADIER SNOW.
WEDNESDAY AND THURSDAY...MAINLY VFR.
FRIDAY...VFR/MVFR. A CHANCE OF RAIN SHOWERS.
&&
.MARINE...
A MODERATE TO STRONG PRESSURE GRADIENT WILL DEVELOP TODAY ACROSS THE
LOWER LAKES BETWEEN LOW PRESSURE OVER NORTHERN QUEBEC AND HIGH
PRESSURE OVER THE SOUTHEAST STATES. A LOW LEVEL JET WILL PEAK THIS
AFTERNOON AT 40 KNOTS...HOWEVER NOT ALL OF THIS WILL MIX DOWN TO
THE LAKE SURFACE. BEST WINDS THROUGH MID-MORNING HAVE BEEN ON THE
NORTH SHORES OF EACH OF THE LAKES...WITH SURFACE TEMPERATURES IN
THE UPPER 30S ADVECTING ACROSS WATER TEMPS IN THE LOWER 40S.
TEMPERATURES WILL WARM INTO THIS AFTERNOON...SO WHILE THE LOW
LEVEL JET STRENGTHENS...LESS MIXING SHOULD OFFSET THIS. WITH WINDS
SHIFTING MORE WSW LATE AFTERNOON...FUNNELING SHOULD BRIEFLY PUSH
WINDS TO 30 KTS ON EASTERN PORTIONS OF LAKE ERIE.
THE LOW LEVEL JET WILL DIMINISH BEHIND THE FRONT...BUT BETTER
MIXING IN THE COLD AIR ADVECTION WILL KEEP WINDS UP OVERNIGHT
ACROSS THE LAKES.
WINDS AND WAVES WILL SUBSIDE MONDAY AS A NARROW RIDGE OF HIGH
PRESSURE BUILDS OVER THE LOWER LAKES. THIS WILL BE SHORT LIVED AS
THE PRESSURE GRADIENT PICKS UP AGAIN MONDAY NIGHT AHEAD OF THE NEXT
LOW MOVING ACROSS ONTARIO AND QUEBEC...PRODUCING MORE SMALL CRAFT
ADVISORY CONDITIONS.
&&
.CLIMATE...
BUFFALO AND ROCHESTER AIRPORTS OFFICIALLY HAD NOW SNOW ON THE
GROUND ON CHRISTMAS MORNING...MAKING 2011 A GREEN CHRISTMAS FOR
BOTH LOCATIONS. WHETHER IT IS A WHITE CHRISTMAS OR NOT IS BASED ON
THE READING TAKING AT 700 AM ON CHRISTMAS MORNING...SO EVEN IF
MEASURABLE SNOW DOES OCCUR THIS EVENING...IT WOULD BE TOO LATE FOR
THE RECORD BOOKS. HOWEVER...SATELLITE SHOWS SOME SNOW ACROSS
PORTIONS OF THE SOUTHERN TIER AND A FEW OF THE FAR SOUTH
TOWNS...AS WELL AS THE TUG HILL...SO THOSE IN SEARCH OF SNOW TO
NOT HAVE TO GO TOO FAR.
THE WINTER OF 2011-12 HAS STARTED AT A RECORD SLOW PACE IN THE
SNOWFALL CATEGORY ACROSS WESTERN AND CENTRAL NEW YORK. THROUGH
DECEMBER 24TH...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 UNTIL 4 AM EST MONDAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LOZ030.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR LOZ043>045.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR LOZ042.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL
MARINE...APFFEL/HITCHCOCK
CLIMATE...THOMAS/HITCHCOCK/JJR/APFFEL
AREA FORECAST DISCUSSION
NWS BUFFALO NY
1158 AM EST SUN DEC 25 2011
.SYNOPSIS...
IT WILL BE A RATHER WINDY AND MILD CHRISTMAS DAY WITH A MIX OF
CLOUDS AND A LITTLE SUNSHINE FOR MOST OF THE DAY. A COLD FRONT AND
UPPER LEVEL DISTURBANCE WILL CROSS THE REGION LATE THIS AFTERNOON
AND THIS EVENING WITH A ROUND OF LIGHT SNOW SHOWERS FOR MUCH OF THE
REGION BRIEFLY BEGINNING AS RAIN. ACCUMULATIONS WILL BE VERY LIMITED
EXCEPT ACROSS THE HIGHER TERRAIN OF THE WESTERN SOUTHERN TIER AND
TUG HILL REGION WHERE SEVERAL INCHES OF SNOW IS POSSIBLE. ANY
LINGERING SNOW SHOWERS WILL QUICKLY END MONDAY AS HIGH PRESSURE
BUILDS INTO THE LOWER LAKES. LOW PRESSURE WILL BRING MORE UNSETTLED
WEATHER TUESDAY WITH SOME LIGHT RAIN ENDING AS A BRIEF PERIOD OF
LIGHT SNOW TUESDAY NIGHT.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
WHILE EARLY MORNING CLOUDS HAVE LARGELY GIVEN WAY TO AT LEAST SOME
SUNSHINE...A FEW SNOW SHOWERS OR FLURRIES HAVE DEVELOPED EAT OF
LAKE ONTARIO. THESE WILL BE SHORT LIVED AS THEY RACE OFF TO THE
EAST...BUT A DUSTING IS POSSIBLE ACROSS HIGHER ELEVATIONS OF LEWIS COUNTY.
BY LATE THIS AFTERNOON A STRONG SHORTWAVE WILL BE ON OUR DOORSTEP.
LARGE SCALE FORCING FOR ASCENT WILL QUICKLY INCREASE AFTER 21Z AS
STRONG DPVA AND HEIGHT FALLS OVERSPREAD THE LOWER LAKES. THE NEW
12Z NAM AND HRRR ARE A TAD SLOWER (AN HOUR OR TWO) WITH THE START
OF THE SHOWERS. EXPECT SCATTERED SHOWERS TO DEVELOP AROUND SUNSET
ACROSS WESTERN NY AND THE NORTH COUNTRY THEN QUICKLY SPREAD ACROSS
THE REMAINDER OF THE REGION THROUGH EARLY EVENING. THIS SHOULD
KEEP THE VAST MAJORITY OF THE DAYLIT HOURS DRY ACROSS WESTERN NEW
YORK.
NAM/GFS BUFKIT PROFILES SHOW THE BOUNDARY LAYER INITIALLY WARM
ENOUGH FOR MUCH OF THIS TO BE RAIN AT THE START...BUT COLD AIR
ADVECTION AND EVAPORATE COOLING WILL QUICKLY CHANGE THE RAIN
OVER TO SNOW BY MID TO LATE EVENING.
THIS SYSTEM IS FAST MOVING AND RELATIVELY MOISTURE STARVED...SO THIS
WILL GREATLY LIMIT ACCUMULATIONS IN MOST AREAS ESPECIALLY
CONSIDERING THE MILD START AT THE ONSET OF PRECIP. THE MAJORITY OF
THE LOWER ELEVATIONS ACROSS THE REGION WILL SEE LESS THAN AN
INCH...AND PERHAPS NOTHING AT ALL IN SOME AREAS CLOSE TO THE
LAKESHORES. THERE WILL BE TWO NOTABLE EXCEPTIONS TO THIS HOWEVER...
EAST OF LAKE ONTARIO BUFKIT PROFILES AND MESOSCALE MODEL DATA BOTH
SUPPORT A SHORT WINDOW OF SEVERAL HOURS FROM MID TO LATE EVENING
WHERE CONDITIONS BECOME FAVORABLE FOR LAKE ENHANCEMENT NEAR THE TIME
OF THE COLD FRONTAL PASSAGE. NAM BUFKIT PROFILES BRING LAKE INDUCED
EQUILIBRIUM LEVELS ALL THE WAY UP TO 15K FEET FOR A FEW HOURS WITH
WELL ALIGNED WESTERLY FLOW. THIS SHOULD SET THE STAGE FOR LAKE
ENHANCEMENT AT THE EAST END OF THE LAKE...MAXIMIZED ACROSS THE TUG
HILL IN THE FAVORED UPSLOPE AREAS. THE SNOW COULD BECOME QUITE HEAVY
FOR A BRIEF PERIOD OF TIME...BUT THE SHORT DURATION WILL PREVENT ANY
BIG ACCUMULATIONS. HAVE GONE WITH 3-4 INCHES ACROSS THE TUG HILL
REGION FOR TONIGHT. HELD OFF ON ADVISORY FOR NOW GIVEN THE MARGINAL
SNOW NUMBERS AND THE FACT THAT THE GREATER ACCUMULATIONS WILL BE
LIMITED TO A SMALL AREA ACROSS HIGHER TERRAIN...BUT DAY SHIFT MAY
NEED TO CONSIDER A HEADLINE. ACROSS LOWER ELEVATIONS MARGINAL
BOUNDARY LAYER TEMPS WILL GREATLY LIMIT ACCUMULATIONS...ESPECIALLY
CLOSER TO THE LAKE ONTARIO SHORE WHERE VERY LITTLE ACCUMULATION IS
EXPECTED.
AFTER MIDNIGHT THE LAKE ENHANCEMENT WILL EVOLVE INTO PURE LAKE
EFFECT BUT QUICKLY MOVE TO SOUTHEAST OF THE LAKE AS THE BOUNDARY
LAYER FLOW BECOMES NORTHWEST. THIS WILL SET UP RELATIVELY WEAK SNOW
SHOWERS FROM NEAR ROCHESTER OVER TO OSWEGO COUNTY AND DOWN INTO THE
FINGER LAKES. MAY SEE SOME SPOTTY ONE INCH AMOUNTS FROM
THIS...ESPECIALLY FROM THE EASTERN SUBURBS OF ROCHESTER INTO WAYNE
COUNTY. QUICK DRYING OF THE SYNOPTIC BACKGROUND AND VERY MARGINAL
INSTABILITY AFTER MIDNIGHT WILL PREVENT ANYTHING MORE SIGNIFICANT.
THE OTHER AREA OF CONCERN IS ACROSS THE CHAUTAUQUA RIDGE. NAM BUFKIT
PROFILES SUGGEST A WINDOW FROM ABOUT 03Z-09Z WHERE NORTHWEST UPSLOPE
FLOW AND MODEST LAKE ENHANCEMENT WILL BECOME FAVORABLE FOR MINOR
ACCUMULATIONS IN THE TYPICAL AREAS ALONG THE RIDGE LINE FROM SHERMAN
UP THROUGH MAYVILLE TO PERRYSBURG. AGAIN THE QUICK DRYING OUT OF THE
SYNOPTIC MOISTURE AND SHORT FETCH/LIMITED INSTABILITY WILL PREVENT
ANY SIGNIFICANT ACCUMULATIONS...BUT MAY SEE 2-4 INCH AMOUNTS IN SOME
AREAS. MAY ALSO SEE 1-2 INCH AMOUNTS FARTHER NORTH ACROSS THE BOSTON
HILLS AND WYOMING COUNTY...ALTHOUGH THE FLOW QUICKLY ESTABLISHES TOO
MUCH NORTHERLY COMPONENT FOR MUCH LAKE ENHANCEMENT IN THOSE AREAS.
ALL OF THIS SHOULD BE ON THE WANE BEFORE DAYBREAK MONDAY AS A RIDGE
OF HIGH PRESSURE BUILDS TOWARDS LAKE ERIE AND MOISTURE QUICKLY
DECREASES.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
FOLLOWING THE PASSAGE OF TODAY`S SYSTEM...STRONG RIDGING WILL BUILD
ACROSS THE AREA AT ALL LEVELS ON MONDAY. ASSOCIATED STRONG DRYING
AND SUBSIDENCE WILL BRING A QUICK END TO ANY LINGERING LAKE EFFECT
SNOW SHOWERS SOUTHEAST OF LAKE ONTARIO IN THE MORNING...ALONG WITH
THE RETURN OF A DECENT AMOUNT OF SUNSHINE. WITH A SEASONABLY COLDER
AIRMASS IN PLACE...DAYTIME TEMPS WILL BE CLOSER TO NORMAL FOR LATE
DECEMBER...OR IN THE LOWER TO MID 30S.
DURING MONDAY NIGHT...THE AFOREMENTIONED RIDGE WILL SLIDE OFF THE
EAST COAST...ALLOWING A PAIR OF SHORTWAVE TROUGHS...ONE IN THE
NORTHERN STREAM AND ONE IN THE SOUTHERN STREAM...TO APPROACH THE
AREA FROM THE NATION`S MIDSECTION. IN ADVANCE OF THESE FEATURES...A
DEEP SOUTHWESTERLY FLOW OF MILDER AIR WILL OVERSPREAD THE AREA...
WITH THE RESULTING WARM AIR ADVECTION LEADING TO BOTH AN INCREASE IN
CLOUD COVER AND A NON-DIURNAL TEMPERATURE TREND...WITH TEMPS
STEADILY RISING AFTER EARLY EVENING LOWS IN THE MID 20S TO LOWER
30S. WITH THE NAM/GFS/GEM AND ECMWF NOW ALL IN GOOD AGREEMENT THAT
ANY PRECIP WILL REMAIN SAFELY WEST OF THE AREA THROUGH THE
NIGHT...HAVE PULLED ANY MENTION OF PRECIP FROM LATE MONDAY NIGHT.
ON TUESDAY...THE AFOREMENTIONED PAIR OF TROUGHS WILL CONTINUE TO
ADVANCE ON THE REGION FROM THE WEST...WITH THE VARIOUS GUIDANCE
PACKAGES CONTINUING TO SHOW DISPARITIES WITH RESPECT TO EXACTLY HOW
MUCH THESE FEATURES PHASE TOGETHER AS THEY APPROACH. AT THIS
TIME...THE SPREAD IN THE GUIDANCE CURRENTLY RANGES FROM THE UNPHASED
00Z NAM/GFS/GEM SOLUTIONS TO THE 00Z ECMWF...WHICH SHOWS THE TWO
WAVES MERGING INTO A RATHER SHARP FULL LATITUDE TROUGH. REGARDLESS
OF WHICH OF THESE SCENARIOS YOU BELIEVE...ALL GENERALLY DEPICT A
DEVELOPING LOW PRESSURE SYSTEM QUICKLY LIFTING NORTHEAST FROM THE
TENNESSEE VALLEY TO THE MID ATLANTIC STATES ON TUESDAY...WITH AN
ASSOCIATED RIBBON OF MOISTURE AND LIFT SPREADING NORTHEAST ACROSS
OUR REGION. THIS SHOULD RESULT IN A LIKELIHOOD OF PRECIP SPREADING
NORTHEAST ACROSS THE REGION DURING THE DAY. AS FOR PTYPE...EXPECTED
MILD BOUNDARY LAYER TEMPS IN THE 40S AND 850 MB TEMPS OF ZERO TO -4C
SHOULD BE SUPPORTIVE OF MAINLY RAIN RIGHT THROUGH THE DAY...WITH
PERHAPS A LITTLE SNOW MIXING IN LATE AS THE COLUMN BEGINS TO COOL A
BIT MORE STRONGLY.
AS THE SURFACE LOW LIFTS FURTHER NORTHEAST ALONG THE NEW ENGLAND
COAST TUESDAY NIGHT...COLD ADVECTION ON ITS BACKSIDE WILL INCREASE.
THIS WILL DELIVER A PROGRESSIVELY COLDER AIRMASS INTO OUR
REGION...RESULTING IN ANY PRECIP CHANGING OVER FROM RAIN TO ALL
SNOW. THE MAIN ISSUE DURING THIS TIME FRAME WILL BE HOW QUICKLY THE
PRECIP TAPERS OFF...WHICH WILL DIRECTLY INFLUENCE POTENTIAL SNOWFALL
ACCUMULATIONS AND WILL BE A DIRECT FUNCTION OF EXACTLY MUCH PHASING
OF THE NORTHERN AND SOUTHERN STREAMS OCCURS. THE FULLY PHASED ECMWF
SOLUTION WOULD SUPPORT A STRONGER AND SLOWER MOVING SURFACE LOW ON A
MORE WESTERLY TRACK...AND WOULD DELIVER COLDER AIR MORE STRONGLY
WHILE ALSO MAINTAINING PRECIP ACROSS THE AREA LONGER...THEREBY
RESULTING IN WHAT WOULD BE A WIDESPREAD ACCUMULATING SNOW. IN
CONTRAST...THE LESS PHASED NAM/GFS/GEM SOLUTIONS OFFER WEAKER
COLD ADVECTION AND A MUCH QUICKER END TO THE SYNOPTIC-SCALE
PRECIP...RESULTING IN MUCH MORE LIMITED ACCUMULATIONS AFTER THE
CHANGEOVER.
WITH HPC PREFERENCES CURRENTLY TOWARD A FASTER...MORE NON-PHASED
SOLUTION LED BY THE CANADIAN GEM...FOR NOW WILL ELECT TO GO WITH A
FASTER END TO THE MAIN SWATH OF SYNOPTIC SCALE PRECIP TUESDAY
NIGHT...WITH LAKE-DRIVEN SNOW SHOWERS TAKING OVER AS A NORTHERLY
FLOW OF PROGRESSIVELY COLDER AIR SPREADS ACROSS THE AREA OVERNIGHT.
THIS SHOULD STILL RESULT IN AT LEAST SOME LIMITED ACCUMULATIONS IN
MANY AREAS BY MORNING...THOUGH THE SHORT NORTHERLY FETCH AND
INCREASINGLY DRY AIRMASS SHOULD KEEP THESE FROM GETTING OUT OF HAND.
WEDNESDAY SHOULD THEN FEATURE A GENERAL REPEAT OF MONDAY...AS THE
COMBINATION OF INCREASING RIDGING/DRYING/SUBSIDENCE HELPS TO SHUT
DOWN ANY LINGERING LAKE EFFECT DURING THE MORNING...AS WELL AS BRING
A RETURN TO AT LEAST SOME PARTIAL SUNSHINE. WITH A MUCH COLDER
AIRMASS IN PLACE /850 TEMPS AVERAGING AROUND -10C/...DAYTIME HIGHS
WILL BE MUCH COLDER THAN TUESDAY`S...WITH READINGS RANGING FROM THE
MID 20S ACROSS THE NORTH COUNTRY TO AROUND 30 ELSEWHERE. CONTINUED
DRY BUT SEASONABLY CHILLY WEATHER WILL THEN FOLLOW FOR WEDNESDAY
NIGHT AS RIDGING CRESTS OVERHEAD AT ALL LEVELS.
&&
.LONG TERM /THURSDAY THROUGH SATURDAY/...
IN THE EXTENDED PORTION OF THE FORECAST...SLOWLY DEPARTING SURFACE
RIDGING IS EXPECTED TO KEEP A CONTINUATION OF MAINLY DRY WEATHER
ACROSS OUR REGION THROUGH THURSDAY. THEREAFTER...ONE OR MORE WAVES
OF LOW PRESSURE ZIPPING ALONG IN A PERSISTENT FAST ZONAL FLOW WILL
BRING RENEWED PRECIP CHANCES FOR BOTH FRIDAY AND NEW YEAR`S EVE.
AS IS USUALLY THE CASE IN SUCH A PATTERN...THE MEDIUM RANGE GUIDANCE
CONTINUES TO HAVE TROUBLE COMING INTO CONVERGENCE ON THE TIMING AND
EXACT POSITIONING OF SUCH SYSTEMS...SO BROADBRUSH CHANCE POPS WILL
REMAIN IN ORDER FOR THE END OF THE WEEK. WITH THE PREVAILING ZONAL
FLOW...SOME MODERATION IN TEMPS FROM WEDNESDAY`S COLDER READINGS
SHOULD DEVELOP...WHICH SHOULD BE SUPPORTIVE OF A RAIN/SNOW SHOWER
MIX DEPENDING UPON THE TIME OF DAY.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
THROUGH 15Z...LINGERING MVFR CIGS ARE CONFINED TO THE NIAGARA
FRONTIER...WITH THIS BAND ERODING AS FORECAST BY MOST MODELS.
EXPECT ALL SITES TO BE VFR FOR MUCH OF TODAY...BEFORE A SHORTWAVE
BRINGS SHOWERS AND LOWERING CONDITIONS THIS EVENING.
SCATTERED RAIN SHOWERS WILL DEVELOP LATE THIS AFTERNOON AND EARLY
EVENING BEFORE MIXING WITH AND CHANGING TO SNOW SHOWERS OVERNIGHT.
EXPECT CIGS/VSBY TO BE VFR AT FIRST AS THE LOW LEVELS REMAIN
UNSATURATED. CONDITIONS WILL DETERIORATE TO MVFR BY MID TO LATE
EVENING AS SNOW SHOWERS BECOME MORE WIDESPREAD. SOME IFR WILL
DEVELOP AS WELL IN MORE PERSISTENT SNOW EAST OF LAKES ERIE AND
ONTARIO. THIS WILL TARGET THE CHAUTAUQUA RIDGE INCLUDING KJHW OFF
LAKE ERIE...AND THE TUG HILL REGION BETWEEN KART AND KSYR EAST OF
LAKE ONTARIO.
OUTLOOK...
MONDAY...VFR/MVFR WITH WITH MORNING SNOW SHOWERS SOUTHEAST OF THE
LAKES...THEN VFR.
TUESDAY AND TUESDAY NIGHT...MVFR IN RAIN SHOWERS CHANGING TO SNOW
SHOWERS TUESDAY NIGHT.
WEDNESDAY AND THURSDAY...MAINLY VFR.
&&
.MARINE...
A MODERATE TO STRONG PRESSURE GRADIENT WILL DEVELOP TODAY ACROSS THE
LOWER LAKES BETWEEN LOW PRESSURE OVER NORTHERN QUEBEC AND HIGH
PRESSURE OVER THE SOUTHEAST STATES. A LOW LEVEL JET WILL PEAK THIS
AFTERNOON AT 40 KNOTS...HOWEVER NOT ALL OF THIS WILL MIX DOWN TO
THE LAKE SURFACE. BEST WINDS THROUGH MID-MORNING HAVE BEEN ON THE
NORTH SHORES OF EACH OF THE LAKES...WITH SURFACE TEMPERATURES IN
THE UPPER 30S ADVECTING ACROSS WATER TEMPS IN THE LOWER 40S.
TEMPERATURES WILL WARM INTO THIS AFTERNOON...SO WHILE THE LOW
LEVEL JET STRENGTHENS...LESS MIXING SHOULD OFFSET THIS. WITH WINDS
SHIFTING MORE WSW LATE AFTERNOON...FUNNELING SHOULD BRIEFLY PUSH
WINDS TO 30 KTS ON EASTERN PORTIONS OF LAKE ERIE.
THE LOW LEVEL JET WILL DIMINISH BEHIND THE FRONT...BUT BETTER
MIXING IN THE COLD AIR ADVECTION WILL KEEP WINDS UP OVERNIGHT
ACROSS THE LAKES.
WINDS AND WAVES WILL SUBSIDE MONDAY AS A NARROW RIDGE OF HIGH
PRESSURE BUILDS OVER THE LOWER LAKES. THIS WILL BE SHORT LIVED AS
THE PRESSURE GRADIENT PICKS UP AGAIN MONDAY NIGHT AHEAD OF THE NEXT
LOW MOVING ACROSS ONTARIO AND QUEBEC...PRODUCING MORE SMALL CRAFT
ADVISORY CONDITIONS.
&&
.CLIMATE...
BUFFALO AND ROCHESTER AIRPORTS OFFICIALLY HAD NOW SNOW ON THE
GROUND ON CHRISTMAS MORNING...MAKING 2011 A GREEN CHRISTMAS FOR
BOTH LOCATIONS. WHETHER IT IS A WHITE CHRISTMAS OR NOT IS BASED ON
THE READING TAKING AT 700 AM ON CHRISTMAS MORNING...SO EVEN IF
MEASURABLE SNOW DOES OCCUR THIS EVENING...IT WOULD BE TOO LATE FOR
THE RECORD BOOKS. HOWEVER...SATELLITE SHOWS SOME SNOW ACROSS
PORTIONS OF THE SOUTHERN TIER AND A FEW OF THE FAR SOUTH
TOWNS...AS WELL AS THE TUG HILL...SO THOSE IN SEARCH OF SNOW TO
NOT HAVE TO GO TOO FAR.
THE WINTER OF 2011-12 HAS STARTED AT A RECORD SLOW PACE IN THE
SNOWFALL CATEGORY ACROSS WESTERN AND CENTRAL NEW YORK. THROUGH
DECEMBER 24TH...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 UNTIL 4 AM EST MONDAY FOR LEZ020.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR LEZ040-041.
SMALL CRAFT ADVISORY UNTIL 4 AM EST MONDAY FOR LOZ030.
SMALL CRAFT ADVISORY UNTIL 4 PM EST MONDAY FOR LOZ043>045.
SMALL CRAFT ADVISORY UNTIL 10 AM EST MONDAY FOR LOZ042.
&&
$$
SYNOPSIS...HITCHCOCK
NEAR TERM...APFFEL/HITCHCOCK
SHORT TERM...JJR
LONG TERM...JJR
AVIATION...APFFEL/HITCHCOCK
MARINE...APFFEL/HITCHCOCK
CLIMATE...THOMAS/HITCHCOCK/JJR/APFFEL
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
249 PM EST SUN DEC 25 2011
.SYNOPSIS...
A QUICK MOVING UPPER LEVEL DISTURBANCE WILL BRING A BRIEF CHANCE 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 THE 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 /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...MOISTURE WILL BE ON THE INCREASE THIS AFTERNOON. LOOK
FOR A CHANCE FOR PATCHY LIGHT RAIN MAINLY OVER THE SOUTHERN
TERMINALS. EVEN WITH THE POSSIBLE PRECIP...CEILINGS ARE EXPECTED TO
REMAIN VFR INTO THE EVENING HOURS...POSSIBLY LOWERING TO MVFR BEHIND
THE FRONT TONIGHT. OVERNIGHT...WINDS WILL SLOWLY SHIFT TO THE
NORTHWEST AS THE FRONT SAGS SOUTHEAST OF THE CWA...TAKING THE
MOISTURE WITH IT. SCATTERED SKIES ARE EXPECTED BY THE END OF THE
FORECAST PERIOD. MONDAY...NEARLY CLEAR SKIES WITH A GUSTY NORTH
NORTHEAST WIND AS HIGH PRESSURE BUILDS IN.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SHOWERS AND INTERMITTENT
IFR CONDITIONS TUESDAY. VFR WEDNESDAY AND THURSDAY.
&&
.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...DL
AREA FORECAST DISCUSSION
NWS NEWPORT/MOREHEAD CITY NC
202 PM EST SUN DEC 25 2011
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY WILL REMAIN WELL SOUTH OF NORTH
CAROLINA TODAY. A DRY COLD FRONT WILL CROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY. 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 NEXT WEEK.
&&
.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 1 PM SUN...MID/HIGH CLOUDS CURRENTLY STREAMING EAST ACROSS
THE REGION ASSOCIATED WITH A LOW PRESSURE SYSTEM PUSHING EAST
ALONG A STALLED FRONTAL BOUNDARY WELL SOUTH OF THE REGION. TEMPS
LOOK TO BE IN GOOD SHAPE AS MOST INSOLATION OCCURRED PRIOR TO
CURRENT CLOUD COVER...STILL EXPECTING READINGS NEAR 60 FOR
LOCATIONS FROM KINSTON TO NEW BERN AND SOUTH. LIGHT SOUTHERLY
WINDS WILL CONTINUE TO VEER SOUTHWEST AND INCREASE 5 TO 10 KNOTS
THIS AFTERNOON IN RESPONSE TO A GRADIENT BETWEEN LOW PRESSURE
SOUTH OF THE REGION AND HIGH PRESSURE BUILDING NORTH OF THE AREA.
LATEST 12Z NAM/17Z RUC/15Z HRRR KEEP PRECIP OFF THE COAST LATE THIS
EVENING AND OVERNIGHT SO NO SIGNIFICANT CHANGES FOR POPS/WX WITH
THE EARLY AFTERNOON UPDATE.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH 6 AM MONDAY/...
AS OF 1 PM SUN...FRONTAL BOUNDARY WILL REMAIN SOUTH OF THE REGION
TONIGHT AS A DRY COLD FRONT PUSHES THROUGH THE AREA. WINDS WILL
SHIFT WEST THEN NORTHWEST OVERNIGHT WITH SURFACE WINDS 5-7 KNOTS.
MIXING WILL KEEP TEMPS IN THE MID/UPPER 30S...ALTHOUGH DRIER
AIRMASS IS EXPECTED TO COVER THE REGION FROM NORTHWEST TO
SOUTHEAST CURRENT DEWPOINTS RANGE IN THE LOW/MID 40S FOR PORTIONS
SOUTH OF HWY 64...THUS TEMPS MAY NEED TO BE ADJUSTED UPWARDS A FEW
DEGREES OVERNIGHT IN THESE AREAS. SKIES BECOME MOSTLY CLEAR BY 06Z.
&&
.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
AS OF 200 PM SUNDAY...MONDAY NIGHT I WILL DELAY THE ONSET OF
INCREASING CLOUDS UNTIL VERY LATE BASED ON THE MOVEMENT OF THE
SURFACE HIGH IN THE LATEST GUIDANCE. THIS MEANS THERE WILL BE A
WINDOW FOR RADIATIONAL COOLING IN THE EVENING THUS FOLLOWED THE
COOLER GUIDANCE FOR LOWS. THE INCREASING CLOUDS WILL COINCIDE WITH
DEVELOPING SE RETURN FLOW WHICH WILL LEAD TO THE MINIMUM
TEMPERATURES OCCURRING EARLY THEN TEMPERATURES RISING LATE.
THE MOST SIGNIFICANT WEATHER DURING THE LONG TERM PERIOD WILL OCCUR
TUESDAY INTO TUESDAY EVENING. THE PERSISTENT SW CUT-OFF UPPER LOW
WILL FINALLY EMERGE AS A DAMPENING WAVE TUESDAY DEVOLVING INTO AN
OPEN WAVE AS IT CROSSES THE MID ATLANTIC TUESDAY NIGHT. DEVELOPING
LOW PRESSURE WILL PASS JUST NORTH OF EASTERN NC TUESDAY EVENING AND
SWING A STRONG COLD FRONT ACROSS THE REGION TUESDAY NIGHT. THIS
SYSTEM WILL HAVE STRONG FORCING WITH LARGE HEIGHT FALLS PRODUCING
DEEP ASCENT AND STRONG SHEAR DUE TO STRENGTHENING WIND FIELDS. THE
FLOW WILL ALSO TAP THE GULF OF MEXICO AND ATLANTIC WITH PW VALUES
SURGING IN EXCESS OF 1.5". THIS WILL LEAD TO THE DEVELOPMENT OF
WIDESPREAD SHOWERS WITH HEAVY DOWNPOURS AHEAD OF AND ALONG THE
FRONT. INSTABILITY WILL BE LIMITED AS IS USUAL THIS TIME OF YEAR BUT
CAN`T RULE A FEW STRONG TO SEVERE THUNDERSTORMS. SIGNIFICANT
RAINFALL IS EXPECTED WITH QPF AMOUNTS OF 0.75" TO LOCALLY 1 INCH OR
MORE POSSIBLE. THE ASSOCIATED SOUTHERLY FLOW WILL PRODUCE MILD
TEMPERATURES IN THE 60S.
A BROAD SURFACE RIDGE OF HIGH PRESSURE IS EXPECTED ACROSS THE REGION
WEDNESDAY THROUGH NEXT WEEKEND WITH DRY WEATHER AND SEASONABLE
TEMPERATURES EXPECTED. THE FAST PACIFIC FLOW...HOWEVER...IS HARD TO
MODEL AND THE GUIDANCE WILL HAVE TROUBLE HANDLING THE EVOLUTION OF
THE LOW AMPLITUDE SHORTWAVES WHICH WILL BE RACING ACROSS THE COUNTRY
THROUGH THIS PERIOD. IF ANY OF THESE OF WAVES IS ABLE TO AMPLIFY IN
THE SHALLOW BROAD UPPER TROUGH FORECAST FROM THE MISSISSIPPI VALLEY
TO THE APPALACHIANS MOUNTAINS...THEN A WETTER PERIOD COULD DEVELOP
LATE NEXT WEEK. SOME OF THE GFS ENSEMBLE MEMBERS ARE ALREADY
INDICATING SUCH A SCENARIO FOR THURSDAY NIGHT INTO FRIDAY AND AGAIN
ON SUNDAY. FOR NOW WILL MAINTAIN A DRY FORECAST UNTIL A BETTER
CONSENSUS DEVELOPS AMONGST THE LONG RANGE MODELS.
&&
.AVIATION /19Z SUNDAY THROUGH FRIDAY/...
SHORT TERM / THROUGH TONIGHT/...
AS OF 105 PM SUN...VFR CONDITIONS EXPECTED THROUGH MON. MID AND HIGH
CLOUDS WILL CONTINUE ACROSS THE AREA TODAY WITH SOUTHWEST WINDS
AS LOW PRESSURE TRACKS WELL TO THE SOUTH. A STRONG DRY COLD FRONT
MOVES THROUGH AFTER MIDNIGHT TONIGHT WITH WINDS BECOMING WEST THEN
NORTHWEST AROUND 6-9 KT. EXPECT SURFACE WINDS AND MODERATE DEWPOINT
DEPRESSIONS TO INHIBIT FOG FORMATION OR LOW STRATUS TONIGHT. VERY
DRY AIRMASS IN PLACE MON AS HIGH PRESSURE EXTENDS SOUTH ACROSS THE
TAF SITES. EXCELLENT MIXING WILL AID IN GUSTY NORTHWEST WINDS
UPWARDS OF 20 KNOTS MON AFTERNOON. SKIES WILL BECOME MOSTLY CLEAR
AROUND 06Z AND STAY MOSTLY SUNNY MON.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 200 PM SUNDAY...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
PERVADES THE CAROLINAS.
&&
.MARINE...
SHORT TERM /THROUGH CHRISTMAS NIGHT/...
AS OF 110 PM SUN...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
LIGHT SOUTHERLY WINDS AROUND 5 KNOTS. SEAS REMAIN 2 TO 3 FT AT 6
TO 8 SECONDS. WINDS WILL SHIFT SOUTHWEST AS THE DAY PROGRESSES...AND
INCREASE 10 TO 15 KNOTS BY LATE THIS EVENING.
WEAK LOW PRESSURE MOVING ALONG A STALLED FRONT OFF OF THE SE
COAST SHOULD REMAIN WEAK AND FAR ENOUGH SOUTH SO AS NOT TO
INFLUENCE LOW LEVEL FLOW TODAY. HOWEVER...SOME SPOTTY LIGHT RAIN
COULD DEVELOP LATE OVER THE SOUTHERN WATERS. A STRONG DRY COLD
FRONT MOVES THROUGH THE AREA TONIGHT WITH SCA CONDITIONS EXPECTED
FOR ALL OF THE WATERS BY 06Z WITH W-NW WINDS INCREASING TO 20-25
KT AND SEAS BUILDING TO 5-8 FT.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY/...
AS OF 200 PM SUNDAY...A STRONG COLD FRONT WILL APPROACH THE AREA
TUESDAY AND CROSS THE WATERS TUESDAY NIGHT. STRONG SMALL CRAFT
ADVISORY TO POSSIBLE GALE FORCE CONDITIONS WILL OCCUR AHEAD OF AND
JUST BEHIND THE FRONT TUESDAY AND TUESDAY NIGHT. 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 FROM 11 PM THIS EVENING TO 10 AM EST
MONDAY FOR AMZ130-135-156-158.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 PM EST
MONDAY FOR AMZ150-152-154.
&&
$$
SYNOPSIS...DAG
NEAR TERM...DAG
SHORT TERM...DAG
LONG TERM...JME
AVIATION...JME/DAG
MARINE...JME/DAG
AREA FORECAST DISCUSSION...UPDATED
NWS NEWPORT/MOREHEAD CITY NC
109 PM EST SUN DEC 25 2011
.SYNOPSIS...
A STALLED FRONTAL BOUNDARY WILL REMAIN WELL SOUTH OF NORTH
CAROLINA TODAY. A DRY COLD FRONT WILL CROSS THE REGION TONIGHT.
HIGH PRESSURE WILL BUILD IN FROM THE WEST MONDAY. 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 NEXT WEEK.
&&
.NEAR TERM /REST OF CHRISTMAS DAY/...
AS OF 1 PM SUN...MID/HIGH CLOUDS CURRENTLY STREAMING EAST ACROSS
THE REGION ASSOCIATED WITH A LOW PRESSURE SYSTEM PUSHING EAST
ALONG A STALLED FRONTAL BOUNDARY WELL SOUTH OF THE REGION. TEMPS
LOOK TO BE IN GOOD SHAPE AS MOST INSOLATION OCCURRED PRIOR TO
CURRENT CLOUD COVER...STILL EXPECTING READINGS NEAR 60 FOR
LOCATIONS FROM KINSTON TO NEW BERN AND SOUTH. LIGHT SOUTHERLY
WINDS WILL CONTINUE TO VEER SOUTHWEST AND INCREASE 5 TO 10 KNOTS
THIS AFTERNOON IN RESPONSE TO A GRADIENT BETWEEN LOW PRESSURE
SOUTH OF THE REGION AND HIGH PRESSURE BUILDING NORTH OF THE AREA.
LATEST 12Z NAM/17Z RUC/15Z HRRR KEEP PRECIP OFF THE COAST LATE THIS
EVENING AND OVERNIGHT SO NO SIGNIFICANT CHANGES FOR POPS/WX WITH
THE EARLY AFTERNOON UPDATE.
&&
.SHORT TERM /TONIGHT/...
AS OF 1 PM SUN...FRONTAL BOUNDARY WILL REMAIN SOUTH OF THE REGION
TONIGHT AS A DRY COLD FRONT PUSHES THROUGH THE AREA. WINDS WILL
SHIFT WEST THEN NORTHWEST OVERNIGHT WITH SURFACE WINDS 5-7 KNOTS.
MIXING WILL KEEP TEMPS IN THE MID/UPPER 30S...ALTHOUGH DRIER
AIRMASS IS EXPECTED TO COVER THE REGION FROM NORTHWEST TO
SOUTHEAST CURRENT DEWPOINTS RANGE IN THE LOW/MID 40S FOR PORTIONS
SOUTH OF HWY 64...THUS TEMPS MAY NEED TO BE ADJUSTED UPWARDS A FEW
DEGREES OVERNIGHT IN THESE AREAS. SKIES BECOME MOSTLY CLEAR BY 06Z.
&&
.LONG TERM /MONDAY THROUGH SATURDAY/...
SHORTWAVE RIDGE TRAVERSES THE AREA MON WITH TEMPS NEAR TO SLIGHTLY
BELOW NORMAL UNDER MOSTLY SUNNY SKIES. TEMPS WILL COOL RAPIDLY MON
EVE AS SFC HIGH PRES MOVES OVER THE AREA. WINDS VEER SE LATE MON
NIGHT AND THE DEVELOPING ONSHORE MAY CAUSE TEMPS TO RISE DURING
EARLY TUE MORNING. POTENT SOUTHERN STREAM SHORTWAVE MOVING THRU THE
TENN VALLEY EARLY TUE MERGES WITH A NORTHERN STREAM SYSTEM MOVING
THRU THE UPPER MIDWEST. ASSOCD COLD FRONT WILL SLICE THRU EASTERN NC
DURING THE LATE AFTN AND EARLY EVE. MODELS HAVE SLOWED THE FRONT A
BIT BUT ARE IN GOOD AGREEMENT IN SUGGESTING A DECENT COVERAGE OF
SHOWERS AHEAD OF AND IMMEDIATELY ALONG THE FRONT SO HAVE INCREASED
POPS INTO THE LIKELY RANGE FOR THIS TIME PERIOD. CONTINUING TO
MENTION ISOLD TSTM ALTHO INSTABILITY WILL BE MARGINAL. QPF AMOUNTS
ARE EXPECTED TO BE NEAR HALF AN INCH WITH SOME AREAS POSSIBLY UP TO
AN INCH. MILD TEMPS (60S) WILL BE A RESULT OF A SHARP LOW LEVEL
THICKNESS RIDGE MOVING IN DURING THE AFTN BUT HAVE SHAVED OFF A FEW
DEGREES GIVEN THE EXPECTED CLOUD AND PCPN COVERAGE.
PRECIP WILL BE MOVING OFF THE COAST TUE NIGHT BUT MAY LINGER OVER
OBX INTO EARLY WED MORN AS THE MAIN UPPER TROF AND WRAPAROUND
MOISTURE PASS JUST NE OF THE AREA.
RIDGING DEVELOPS AT THE SURFACE WED THROUGH FRI WITH ZONAL FLOW
ALOFT. 00Z OPERATIONAL GFS RUN DEVELOPS LOW PRES OFF THE SE COAST
THU AND MOVES UP THE NC COAST THU NIGHT BUT THIS IS DISCOUNTED
GIVEN THE LACK OF SUPPORT FROM OTHER MODEL GUIDANCE. TEMPS WILL BE
NEAR SEASONAL LEVELS...MID 50S...WED INTO THURS THEN INCREASE TO
SLIGHTLY ABOVE NORMAL (LOW 60S) FRI/SAT. MIN TEMPS WILL ALSO BE NEAR
SEASONAL LEVELS WITH LOWS IN THE MID-UPPER 30S WITH 40S FOR OBX. A
COLD FRONT MAY APPROACH THE AREA FROM THE NW ON SAT BUT WILL NOT
MENTION PRECIP AS YET AWAITING BETTER LONG RANGE MODEL CONSENSUS.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
SHORT TERM / THROUGH TONIGHT/...
AS OF 105 PM SUN...VFR CONDITIONS EXPECTED THROUGH MON. MID AND HIGH
CLOUDS WILL CONTINUE ACROSS THE AREA TODAY WITH SOUTHWEST WINDS
AS LOW PRESSURE TRACKS WELL TO THE SOUTH. A STRONG DRY COLD FRONT
MOVES THROUGH AFTER MIDNIGHT TONIGHT WITH WINDS BECOMING WEST THEN
NORTHWEST AROUND 6-9 KT. EXPECT SURFACE WINDS AND MODERATE DEWPOINT
DEPRESSIONS TO INHIBIT FOG FORMATION OR LOW STRATUS TONIGHT. VERY
DRY AIRMASS IN PLACE MON AS HIGH PRESSURE EXTENDS SOUTH ACROSS THE
TAF SITES. EXCELLENT MIXING WILL AID IN GUSTY NORTHWEST WINDS
UPWARDS OF 20 KNOTS MON AFTERNOON. SKIES WILL BECOME MOSTLY CLEAR
AROUND 06Z AND STAY MOSTLY SUNNY MON.
LONG TERM /MONDAY THROUGH THURSDAY/...
VFR CONDITIONS EXPECTED MON AS HIGH PRESSURE BUILDS ACROSS THE
AREA. RETURN FLOW SETS UP LATE MON NIGHT AND STRENGTHENS TUE AS A
COLD FRONT APPROACHES FROM THE WEST. MVFR/POSSIBLE IFR CONDITIONS
EXPECTED TUE AFTERNOON AND EVENING AS SHOWERS WITH ISOLATED
THUNDERSTORMS PASS THROUGH THE REGION. HIGH PRESSURE BUILDS BACK
OVER THE REGION WED/THU WITH MAINLY VFR EXPECTED.
&&
.MARINE...
SHORT TERM /THROUGH CHRISTMAS NIGHT/...
AS OF 110 PM SUN...LATEST SURFACE AND BUOY OBSERVATIONS INDICATE
LIGHT SOUTHERLY WINDS AROUND 5 KNOTS. SEAS REMAIN 2 TO 3 FT AT 6
TO 8 SECONDS. WINDS WILL SHIFT SOUTHWEST AS THE DAY PROGRESSES...AND
INCREASE 10 TO 15 KNOTS BY LATE THIS EVENING.
WEAK LOW PRESSURE MOVING ALONG A STALLED FRONT OFF OF THE SE
COAST SHOULD REMAIN WEAK AND FAR ENOUGH SOUTH SO AS NOT TO
INFLUENCE LOW LEVEL FLOW TODAY. HOWEVER...SOME SPOTTY LIGHT RAIN
COULD DEVELOP LATE OVER THE SOUTHERN WATERS. A STRONG DRY COLD
FRONT MOVES THROUGH THE AREA TONIGHT WITH SCA CONDITIONS EXPECTED
FOR ALL OF THE WATERS BY 06Z WITH W-NW WINDS INCREASING TO 20-25
KT AND SEAS BUILDING TO 5-8 FT.
LONG TERM /MONDAY THROUGH THURSDAY/...
SCA CONDITIONS WILL CONTINUE THRU MONDAY IN A MODERATE TO STRONG
POST FRONTAL NORTH FLOW. WINDS/SEAS WILL DECREASE QUICKLY MON NIGHT
AS HIGH PRES BUILDS INTO THE REGION. A VEERING FLOW WILL AGAIN
INCREASE AHEAD OF A COLD FRONT ON TUESDAY WITH A RETURN TO SMALL
CRAFT ADVISORY CONDITIONS EXPECTED BY MIDDAY OR SO. WINDS/SEAS PEAK
LATE TUE AFTN AND EVE (WITH A FEW NEAR GALE FORCE GUSTS POSSIBLE)
THEN A GRADUAL DECREASE AS LOW LEVEL CAA WANES IN THE POST FRONTAL
NW/N FLOW LATE TUE NIGHT INTO WED AS BROAD HIGH PRESSURE MIGRATES
EAST ACROSS THE WATERS.
&&
.MHX WATCHES/WARNINGS/ADVISORIES...
NC...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 10 AM EST
MONDAY FOR AMZ130-135-156-158.
SMALL CRAFT ADVISORY FROM 11 PM THIS EVENING TO 11 PM EST
MONDAY FOR AMZ150-152-154.
&&
$$
SYNOPSIS...DAG
NEAR TERM...DAG
SHORT TERM...DAG
LONG TERM...BTC/DAG
AVIATION...BTC/RF/DAG
MARINE...BTC/RF/JAC/DAG
AREA FORECAST DISCUSSION
NWS WILMINGTON NC
1200 PM EST SUN DEC 25 2011
.SYNOPSIS...
A QUICK MOVING UPPER LEVEL DISTURBANCE WILL BRING A BRIEF CHANCE OF
RAIN LATE THIS AFTERNOON INTO 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 915 AM SUNDAY...THICKER AND OPAQUE CLOUDINESS TO OVERSPREAD
THE AREA AND AID IN KEEPING MAX TEMPS FROM CLIMBING OUT OF THE 50S.
THE EXCEPTION WILL BE COASTAL SE NC AND NE SC WHERE THE OPAQUE
OVERCAST WILL FILL IN AROUND MIDDAY ALLOWING SOME INSOLATION TO AID
MAX TEMPS REACHING INTO THE 60S. HRRR THE PAST FEW HRS HAS BACKED
DOWN ON THE PCPN COVERAGE LATER THIS AFTERNOON AND EVENING. WILL
TWEAK POPS SLIGHTLY LOWER ESPECIALLY ACROSS THE ILM NC COUNTIES.
PREVIOUS DISCUSSION...............................................
AS OF 630 AM SUNDAY...A SURFACE RIDGE EXTENDING FROM THE DELMARVA
PENINSULA WEST ACROSS THE NC/VA MOUNTAINS AND INTO ARKANSAS WILL
REMAIN ACROSS THE AREA THROUGH THIS EVENING. MORE IMPORTANT TO OUR
WEATHER WILL BE A SHORTWAVE TROUGH CURRENTLY LOCATED ACROSS
MISSISSIPPI THAT WILL MOVE EAST AND ACROSS THE CAROLINAS EARLY THIS
EVENING. A SLUG OF MID-LEVEL MOISTURE FROM THE GULF OF MEXICO AND
LOW-LEVEL MOISTURE FROM BOTH THE GULF AND ATLANTIC WILL GET PULLED
OVERHEAD THIS AFTERNOON. WHEN COUPLED WITH THE WEAK LIFT PROVIDED BY
THE TROUGH WE ARE FORECASTING RAIN CHANCES LATE THIS AFTERNOON AND
EVENING...MAINLY ACROSS SOUTH CAROLINA AND AFTER 2-3 PM. THERE WILL
BE A SHORT WINDOW OF OPPORTUNITY FOR RAIN TO FALL...AND GIVEN THE
MEAGER LIFT ADVERTISED ON THE LATEST GFS/NAM RUNS OUR ACTUAL
RAINFALL FORECASTS ARE FOR 0.05 INCHES OR LESS.
AS THE SHORTWAVE TROUGH EXITS THE COAST THIS EVENING...HIGH PRESSURE
OVER THE CENTRAL PLAINS STATES WILL BUILD EAST AND INTO THE
CAROLINAS. THIS WILL CREATE A SURGE OF COLD NORTHWESTERLY WINDS
AFTER MIDNIGHT THAT WILL CONTINUE THROUGH DAYBREAK MONDAY. HIGHS
TODAY SHOULD RANGE FROM 55-60...WARMEST AT THE COAST. LOWS TONIGHT
SHOULD FALL INTO THE UPPER 30S MOST LOCATIONS.
NOTE: DUE TO COMPUTER PROBLEMS AT NCEP THE 00Z NAM MOS PRODUCTS WERE
NOT PRODUCED.
&&
.SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...FOCUS FOR THE SHORT TERM WILL BE UPPER SYSTEM
TRACKING NORTHEAST FROM TX MON NIGHT. AHEAD OF THE OPENING WAVE VERY
DRY HIGH PRESSURE BUILDING IN MON WILL SHIFT OFF THE NC/VA COAST MON
NIGHT. ANTICIPATE VERY LITTLE IN THE WAY OF CLOUDS MON LET ALON
PRECIP. COLD ADVECTION WILL BE ENDING MON MORNING BUT COOLER AIR
WILL ALREADY BE IN PLACE ENSURING HIGHS RIGHT AROUND CLIMO. RETURN
FLOW DEVELOPING LATE MON NIGHT WILL START TEMPS/DEWPOINTS ON A
GRADUAL UPWARD TREND BEFORE DAYBREAK.
WEAK COASTAL TROF/WARM FRONT MOVES ONSHORE FAIRLY EARLY TUE HELPING
BREAK VERY WEAK WEDGE. STRONG WARM ADVECTION RAPIDLY INCREASES LOW
LEVEL MOISTURE WHILE STRONG SOUTH TO SOUTHWEST MID LEVEL FLOW
INCREASES MOISTURE ABOVE 900 MB. HAVE HELD ONTO LIKELY POP FOR TUE
GIVEN THAT THERE IS STILL SOME QUESTION WITH RESPECT TO TIMING.
WHILE GOOD AGREEMENT BETWEEN THE GUIDANCE CONTINUES...NEARLY ALL OF
THE 00Z SOLUTIONS ARE SLOWER BY ABOUT 6 HOURS OR SO. NOT ONLY WOULD
SLOWER EVOLUTION DELAY PRECIP BUT IT WOULD AFFECT TEMP FORECAST AND
CREATE A LARGER WINDOW FOR CONVECTION. INCREASING INSTABILITY WITHIN
THE WARM SECTOR...DEEP MOISTURE...STRONG DIVERGENCE ALOFT...AND
STRONG LOW LEVEL JET DO POINT TO THE POTENTIAL FOR SOME ISOLATED
STRONG CONVECTION...ESPECIALLY IF THE SLOWER SOLUTION COMES TO PASS.
RAINFALL AMOUNTS IN THE HALF INCH RANGE ARE EXPECTED THOUGH ISOLATED
HIGHER AMOUNTS ARE CERTAINLY POSSIBLE.
COLD FRONT MOVES ACROSS THE AREA LATE TUE FOLLOWED BY A BRIEF PERIOD
OF WEAK COLD ADVECTION. BOUNDARY LAYER MIXING AND LACK OF
SIGNIFICANT COLD ADVECTION KEEPS TUE NIGHT LOWS NEAR TO SLIGHTLY
ABOVE CLIMO...WITH COOLEST AREAS TO THE WEST.
&&
.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
AS OF 3 AM SUNDAY...AS 5H TROF EXITS NORTHEAST WED MORNING THE
PATTERN ALOFT WILL BECOME MORE PROGRESSIVE. ZONAL PATTERN WILL
REMAIN IN PLACE THROUGH THE PERIOD...THOUGH SOME WEAK RIDGING DOES
START TO CREEP IN NEXT WEEKEND. A FEW WEAK MOISTURE STARVED WAVE
WILL PASS JUST NORTH OF THE AREA...BUT A FEW CLOUDS IS ALL THAT CAN
BE EXPECTED. TEMPERATURES NEAR CLIMO FOR MUCH OF THE PERIOD WILL
CREEP ABOVE CLIMO LATE IN THE PERIOD.
IT IS WORTH NOTING THE 00Z GFS IS NOW SHOWING A WEAK WAVE OFF THE
SOUTHEAST COAST THU WHICH MOVES NORTH INTO FRI. ONCE THE LOW REACHES
HATTERAS DIVERGENCE ALOFT...ASSOCIATED WITH SHORTWAVE DIGGING OVER
THE GREAT LAKES...HELPS STRENGTHEN THE LOW. ONLY THE 00Z GFS DEPICTS
THIS SOLUTION AND IT SEEMS OVER AMPLIFIED. WILL IGNORE IT FOR NOW.
&&
.AVIATION /18Z SUNDAY THROUGH FRIDAY/...
AS OF 18Z...MOISTURE WILL BE ON THE INCREASE THIS AFTERNOON. LOOK FOR A
CHANCE FOR PATCHY LIGHT RAIN MAINLY OVER THE SOUTHERN TERMINALS.
EVEN WITH THE POSSIBLE PRECIP...CEILINGS ARE EXPECTED TO REMAIN VFR
INTO THE EVENING HOURS...POSSIBLY LOWERING TO MVFR BEHIND THE FRONT
TONIGHT. OVERNIGHT...WINDS WILL SLOWLY SHIFT TO THE NORTHWEST AS THE
FRONT SAGS SOUTHEAST OF THE CWA...TAKING THE MOISTURE WITH IT.
SCATTERED SKIES ARE EXPECTED BY THE END OF THE FORECAST PERIOD.
MONDAY...NEARLY CLEAR SKIES WITH A GUSTY NORTH NORTHEAST WIND AS
HIGH PRESSURE BUILDS IN.
EXTENDED OUTLOOK...MODERATE CONFIDENCE FOR SHOWERS AND INTERMITTENT
IFR CONDITIONS TUESDAY. VFR WEDNESDAY AND THURSDAY.
&&
.MARINE...
NEAR TERM /THROUGH TONIGHT/...
AS OF 915 AM SUNDAY...SFC BOUNDARY TO NEARLY SPLIT THE ILM COASTAL
WATERS TODAY. WIND DIRECTIONS WILL BE THE PROBLEM CHILD WITH WIND
SPEEDS 10 KT OR LESS DUE TO A RELAXED SFC PG. WILL INDICATE A
VARIABLE WIND DIRECTION THIS AFTERNOON. COLD FRONT DROPS SE AND
SWEEPS ACROSS THE ILM WATERS AND OFFSHORE THIS EVENING. TIGHTENED
SFC PG IN THE WAKE OF THE FRONT AND CAA SURGE TO PUSH W TO NW WINDS
TO SCA CRITERIA FOR THE ILM NC WATERS AROUND MIDNIGHT...AND
CONTINUING AT THESE SPEEDS THROUGH DAYBREAK MONDAY. THE ILM SC
WATERS WILL SEE 15-20 KT SPEEDS. SIGNIFICANT SEAS WILL BE DOMINATED
BY AN EASTERLY 1-3 FT SWELL AT 7 TO 9 SECOND PERIODS TODAY. DUE TO
THE NW FETCH...EXPECT 2 TO 4 FT LOCALLY PRODUCED WIND WAVES AT 3-5
SECOND PERIODS BECOMING THE DOMINATE PLAYER AFTER THE COLD FRONT
PUSHES THIS EVENING.
PREVIOUS DISCUSSION...............................................
AS OF 630 AM SUNDAY...A RIDGE OF HIGH PRESSURE ACROSS SOUTHERN
VIRGINIA WILL REMAIN JUST TO OUR NORTH THROUGH EARLY THIS EVENING.
THIS SHOULD MAINTAIN LIGHT WINDS ACROSS THE COASTAL WATERS. AN
UPPER LEVEL DISTURBANCE COULD BRING A PERIOD OF LIGHT RAIN LATE
THIS AFTERNOON INTO EARLY THIS EVENING ACROSS MAINLY THE SOUTH
CAROLINA WATERS. ANY RAIN SHOULD SHIFT OFFSHORE BEFORE MIDNIGHT.
HIGH PRESSURE OVER THE CENTRAL PLAINS WILL SURGE EAST LATE TONIGHT
BRINGING INCREASING NORTHWESTERLY WINDS WHICH COULD REACH 25 KNOTS
ACROSS THE NORTH CAROLINA WATERS. WE ARE THEREFORE HOISTING A SMALL
CRAFT ADVISORY NORTH OF LITTLE RIVER INLET BEGINNING AT 2 AM MONDAY.
SEAS ARE CURRENTLY 3 FT AT THE FRYING PAN SHOALS BUOY AND 3 FT AT
THE NEARSHORE WRIGHTSVILLE BEACH BUOY. SINCE WINDS ARE FAIRLY LIGHT
A CHECK OF THE SPECTRAL WAVE PLOT CONFIRMS WE ARE MAINLY
EXPERIENCING AN 8-SECOND SWELL. SEAS SHOULD CHANGE LITTLE THROUGH
THIS EVENING...BUT AFTER MIDNIGHT INCREASING OFFSHORE WINDS WILL
DEVELOP A SHORT PERIOD (3-5 SECOND) CHOP LATE.
SHORT TERM /MONDAY THROUGH TUESDAY NIGHT/...
AS OF 3 AM SUNDAY...BRIEF NORTHERLY SURGE WILL BE WEAKENING MON
MORNING BUT MAY REQUIRE HEADLINES FOR THE FIRST FEW HOURS OF THE
PERIOD. WINDS QUICKLY DROP BELOW 15 KT AND VEER TO NORTH-NORTHEAST
MON INTO MON NIGHT AS HIGH PRESSURE SHIFTS OFF THE NC/VA COAST. WARM
FRONT MOVES ONSHORE LATE MON NIGHT WITH WINDS BECOMING ONSHORE AND
INCREASING AS GRADIENT TIGHTENS. COOLER NEARSHORE WATER TEMPS WILL
LIMIT GUSTINESS BUT COULD ALSO RESULT IN SOME SEA FOG. HEADLINES
WILL LIKELY BE NEEDED TUE AS BOTH WINDS AND SEAS ARE EXPECTED TO
EXCEED THRESHOLDS AS DEEPENING LOW PRESSURE MOVES ACROSS THE
CAROLINAS. STRONG COLD FRONT CROSSES THE WATERS TUE NIGHT WITH
STRONG SOUTHWEST FLOW IN ITS WAKE BECOMING WESTERLY. NOT A LOT OF
COLD ADVECTION BEHIND THE FRONT SO WINDS MAY NOT BE VERY GUSTY...BUT
PINCHED GRADIENT WILL KEEP WINDS 15 TO 20 KT INTO WED MORNING. 2 TO
3 FT SEAS MON AND MON NIGHT WILL BUILD TO 6 TO 9 FT BEFORE COLD
FRONT SWEEPS ACROSS THE WATERS TUE NIGHT. SEAS WILL SLOWLY FALL TUE
NIGHT AS WINDS BECOME WEST AND THEN NORTHWEST.
LONG TERM /WEDNESDAY THROUGH THURSDAY/...
AS OF 3 AM SUNDAY...LIGHT WEST TO NORTHWEST FLOW WED AS HIGH
PRESSURE MOVES MOVES EAST ACROSS THE GULF COAST. WINDS BECOME LIGHT
AND VARIABLE LATE WED NIGHT AS RIDGE AXIS ELONGATES AND SHIFTS
SOUTHEAST OF THE AREA. LIGHT RETURN FLOW DEVELOPS BY THU BUT
GRADIENT REMAINS WEAK. SPEEDS THROUGH THE PERIOD WILL GENERALLY BE
10 KT OR LESS WITH SEAS 2 TO 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/TRA
SHORT TERM...III
LONG TERM...III
AVIATION...43
AREA FORECAST DISCUSSION...UPDATED
NWS MILWAUKEE/SULLIVAN WI
1153 AM CST SUN DEC 25 2011
.UPDATE...CLOUD DECK FROM THE NORTHWEST CONTINUES TO SLIDE
SOUTHEAST INTO NORTHERN PORTIONS OF THE AREA. 1000/850MB RELATIVE
HUMIDITY FIELDS ON SHORT TERM MODELS CONTINUE TO BRING THESE
CLOUDS SOUTHEAST THROUGH MOST OF THE AREA THIS
AFTERNOON...LINGERING IN THE EVENING IN THE FAR EAST BEFORE MOVING
OFF TO THE EAST. ALSO...AREA RUC FORECAST SOUNDINGS SUGGEST
DIURNAL CUMULUS CLOUDS SHOULD HELP FILL IN GAPS WITHIN THIS AREA
OF CLOUDS. WILL UPDATE SKY GRIDS TO REFLECT THIS TREND.
CLOUDS SHOULD PUT A HALT TO TEMPERATURE RISES ONCE THEY MOVE
IN...PERHAPS EVEN FALL A BIT. TEMPERATURES IN THE LOWER 40S SEEN
IN SOUTHEAST SECTIONS OF THE AREA WITH GOOD MIXING AND
SUNSHINE...DESPITE COLD AIR ADVECTION OCCURRING. UPDATED
TEMPERATURES TO REFLECT THESE WARMER READINGS.
&&
.AVIATION/18Z TAFS/...VFR CONDITIONS EXPECTED THROUGH MONDAY
ACROSS TAF SITES. VFR CLOUD DECK SHIFTING SOUTHEAST SHOULD
CONTINUE TO DO SO THROUGH THE AFTERNOON...REACHING TAF SITES
BETWEEN 19Z AND 21Z SUNDAY. THESE CLOUDS SHOULD LINGER AT MADISON
UNTIL AROUND 00Z MONDAY...AND BETWEEN 03Z AND 05Z MONDAY AT THE
EASTERN SITES.
BRISK NORTHWEST SUSTAINED WINDS OF 13 TO 18 KNOTS WILL LINGER
UNTIL SUNSET...WITH GUSTS OF 25 TO 29 KNOTS POSSIBLE AT TIMES.
WINDS WILL DIMINISH THIS EVENING AND SHIFT SOUTHWEST BY 10Z TO 12Z
MONDAY. GUSTY SOUTHWEST WINDS EXPECTED BY 15Z MONDAY...LASTING
THROUGH THE DAY. GUSTS TO 25 KNOTS ARE POSSIBLE AT TIMES.
&&
.MARINE...SMALL CRAFT ADVISORY CONTINUES UNTIL 6 PM CST FOR THE
NEARSHORE WATERS. BRISK NORTHWEST WINDS OF 15 TO 25 KNOTS WITH
GUSTS TO AROUND 30 KNOTS ARE EXPECTED THROUGH TODAY...AS TIGHT
PRESSURE GRADIENT LINGERS ACROSS THE AREA. THESE WINDS SHOULD
GENERATE HIGH WAVES...MAINLY TOWARD THE OPEN WATERS. THE WINDS AND
WAVES SHOULD SUBSIDE QUICKLY THIS EVENING...AS PRESSURE GRADIENT
WEAKENS AND MIXING SUBSIDES.
&&
.PREV DISCUSSION... /ISSUED 249 AM CST SUN DEC 25 2011/
TODAY...FORECAST CONFIDENCE...HIGH
POTENT UPPER TROUGH OVER MINNESOTA DIVING THROUGH CENTRAL WISCONSIN
AROUND DAYBREAK BEFORE HEADING INTO CENTRAL LOWER MICHIGAN BY
MIDDAY. STRONG Q-G FORCING WITH 500 MB 12 HOUR HEIGHT FALLS AROUND
120 METERS...PV1.5 DIVING TO 550 MB...AND Q-VECTOR CONVERGENCE ABOVE
30 KNOTS FROM 700-300 MB. HOWEVER...AIRMASS VERY DRY SO NOTHING BUT
MID CLOUDS WITH SYSTEM MOVING AWAY AND SOME STRATOCUMULUS UNDER COLD
CORE THIS AFTERNOON.
COLD FRONT GOES THROUGH FIRST THIS MORNING...WITH BRISK NORTHWEST
FLOW IN ITS WAKE TODAY. MEAN WINDS IN SURFACE 850 MB LAYER DO
INCREASE TO 35 KNOTS FROM THE NORTHWEST THIS AFTERNOON WITH STRONG
COLD ADVECTION AND SUBSIDENCE. SO GUSTS TO 25-30 KNOTS EXPECTED.
MILD THIS MORNING WITH 925 MB TEMPS AROUND +3C BUT CRASHING TO -3C
BY 18Z AND -5C BY 00Z. LOOKS LIKE STRONG COLD ADVECTION WILL
BALANCE TYPICAL DIURNAL RISE...AS TEMPERATURES CURRENTLY IN THE
UPPER 30S AND -3C BY MIDDAY SUPPORTS UPPER 30S WITH ADIABATIC LAPSE
RATE.
TONIGHT...FORECAST CONFIDENCE...HIGH
WEAK SURFACE RIDGE BUILDS IN DURING THE NIGHT WITH LOW LEVEL THERMAL
TROUGH GOING BY AROUND 06Z. WARM ADVECTION KICKS IN TOWARD
SUNRISE...SO MAY SEE TEMPERATURES BOTTOM OUT BETWEEN 06Z AND 09Z AND
THEN LEVEL OFF OR PERHAPS RISE BY 12Z. WINDS SHOULD DROP OFF ENOUGH
FOR A WEAK INVERSION TO DEVELOP AND SUPPORT LOWER 20S...ESPECIALLY
TOWARD THE NORTHWEST WITH LIGHT SNOW COVER.
MONDAY AND TUESDAY...FORECAST CONFIDENCE...MEDIUM
WINDS QUICKLY RETURN TO OUT OF THE SOUTHWEST FOR MONDAY...BECOMING
BREEZY AGAIN LATE MORNING INTO THE AFTERNOON. MODELS HAVE TIGHTENED
THE PRESSURE GRADIENT OVER THE LAST DAY...SO GUSTS TO 30 MPH SEEM
PROBABLE. WITH THESE WINDS...A DECENT AMOUNT OF SUN...AND WARMING
ALOFT...SHOULD HIT 40 OR LOW 40S PRETTY EASILY...ESPECIALLY IN
LOCATIONS WITH NO SNOW COVER.
CONTINUED THE TREND OF CUTTING BACK POPS FOR MONDAY NIGHT...AS
MODELS GENERALLY KEEP THE PRECIP TO THE SOUTH. SOME MID LEVEL
FRONTOGENETIC FORCING AND THETA-E ADVECTING ACROSS THE AREA...BUT
MODEL SOUNDINGS STRUGGLE TO SATURATE BEFORE FORCING MOVES OUT.
ANOTHER SHORTWAVE PROGGED TO SLIDE THROUGH TUESDAY...BUT
MOISTURE/FORCING PRETTY LACKING...SO KEPT FORECAST DRY. WILL BE COLD
ADVECTING IN THE AFTERNOON BEHIND THE WAVE...SO KEPT HIGHS IN THE
MID TO UPPER 30S...THOUGH STILL ABOUT 10 DEGREES ABOVE NORMAL FOR
LATE DECEMBER.
WEDNESDAY THROUGH SATURDAY...FORECAST CONFIDENCE...LOW TO MEDIUM
MODELS SHOWING THE WAVE TRAIN WILL CONTINUE THROUGH THE LATTER HALF
OF THE WORK WEEK AND INTO THE WEEKEND. PRETTY POOR AGREEMENT AMONG
MODELS AS TO TIMING/STRENGTH OF INDIVIDUAL WAVES...SO ENDED UP WITH
LOW POPS FROM THURSDAY ON. THOUGH LOW CONFIDENCE IN DAY TO DAY
PRECIP CHANCES...BETTER CONFIDENCE THAT THIS PATTERN WILL ALLOW
TEMPS TO REMAIN ABOVE NORMAL THROUGH THE END OF THE MONTH.
AVIATION/12Z TAFS/...
925MB WINDS OF 35-40 KNOTS BRIEFLY THIS MORNING FROM THE WEST AND
THEN TURNING NORTHWEST DURING THE DAY AT ABOUT 35 KNOTS. FLOW OF
10-15 KNOTS AT THE SURFACE JUST ENOUGH TO KEEP PROBABILITY OF LOW
LEVEL WIND SHEAR A BIT TOO LOW TO WARRANT MENTIONING.
GOOD MIXING TODAY SHOULD RESULT IN GUSTS OF 25-30 KNOTS AS STRONG
GOES BY TO THE EAST OF AREA AND PRESSURE RISES BEHIND COLD FRONT
KICK IN. AREA OF MVFR TO VFR STRATOCUMULUS OVER NORTHERN MINNESOTA
BENEATH UPPER COLD CORE TROUGH SHOULD MOVE IN FROM LATE MORNING INTO
THE MIDDLE AFTERNOON HOURS...BUT CEILINGS SHOULD BE IN 3500 TO 6000
FEET RANGE.
MARINE...
SURFACE TO 850 MB MEAN WINDS IN NORTHWEST FLOW COLD ADVECTION REGIME
ARE ABOUT 35 KNOTS...BUT IT DOES NOT APPEAR THAT MIXED LAYER WILL
REACH 850 MB SO EXPECTING GUSTS AROUND 30 KNOTS. PROBABILITY OF
FREQUENT GALE FORCE GUSTS TOO LOW TO WARRANT GALE WARNING SO WILL
STICK WITH SMALL CRAFT ADVISORY.
WINDS SHOULD DROP OFF QUICKLY AROUND DARK AS BOUNDARY LAYER
DECOUPLES.
A STRONGER LOW PRESSURE AREA THEN MOVES ACROSS SOUTHERN MANITOBA
INTO NORTHWEST ONTARIO MONDAY...WITH 925 MB WINDS FROM THE
WEST-SOUTHWEST IN THE 45-55 KNOT RANGE. LOW LEVEL STABILITY WILL
AGAIN BE AN ISSUE...SO GUSTS IN THE COASTAL WATERS TO AROUND 30
KNOTS ARE AGAIN LIKELY. A MARGINAL GALE IS AGAIN POSSIBLE...BUT
MORE LIKELY TOWARD OPEN WATER SO ODDS FAVOR NEEDING ANOTHER SMALL
CRAFT ADVISORY MONDAY AFTERNOON AND EARLY EVENING.
&&
.MKX WATCHES/WARNINGS/ADVISORIES...
WI...NONE.
LM...SMALL CRAFT ADVISORY UNTIL 6 PM CST THIS EVENING FOR LMZ643>646.
&&
$$
UPDATE...WOOD
TODAY/TONIGHT AND AVIATION/MARINE...CRAVEN
MONDAY THROUGH SATURDAY...DDV