FXUS61 KALY 012346
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
646 PM EST TUE DEC 1 2009
.SYNOPSIS...
A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION TONIGHT AND
WEDNESDAY...PROVIDING DRY AND RELATIVELY MILD WEATHER. A STRONG LOW
PRESSURE SYSTEM WILL TRACK FROM THE GULF COAST INTO THE EASTERN
GREAT LAKES WEDNESDAY NIGHT AND THURSDAY...BRINGING A SOAKING RAIN
TO THE REGION...FOLLOWED BY COLDER AIR FOR THE END OF THE WEEK.
&&
.NEAR TERM /THROUGH WEDNESDAY/...
STILL DEALING WITH NUISANCE TYPE LAKE EFFECT SNOW. WEBCAMS INDICATE
PLACES LIKE OLD FORGE HAVE PICKED A COUPLE OF INCHES OF SNOW. THE
AIR HAS JUST BEEN COLD ENOUGH...AND UNSTABLE ENOUGH TO TRIGGER A
LAKE RESPONSE OFF LAKE ONTARIO WHICH WAS INITIALLY SPARKED BY A
SHORT WAVE...THEN ENHANCED BY A SURFACE TROUGH BRINGING A SHOT OF
CHILLY AIR OVER THE LAKE WITH NEARLY 270 TRAJECTORY.
HIGH PRESSURE WILL CREST TO OUR SOUTH OVERNIGHT AND THE SUBSIDENCE
INVERSION WILL SLOWLY LOWER. IT WILL TAKE A BIT OF TIME...BUT THE
LAKE EFFECT WILL SLOWLY DISSIPATE AS WE HEAD INTO THE OVERNIGHT
HOURS. THERE COULD BE AN ADDITIONAL INCH OR TWO MORE OF SNOWFALL IN
A FEW SPOTS...ESPECIALLY THE HIGHEST TERRAIN.
THE REST OF THE AREA WILL BE DRY TONIGHT. THE BIG CHALLENGE IS HOW
QUICKLY THE CLOUDS WILL BREAK UP. THERE ARE ALREADY HOLES IN THE
CLOUDS...ESPECIALLY IN THE HUDSON VALLEY. OFTEN TIMES
HOWEVER...LEFTOVER LOW MOISTURE GETS TRAPPED UNDERNEATH THE
INVERSION OVERNIGHT. HOWEVER...THE COLUMN IS ALSO DRYING SLOWLY DUE
TO SUBSIDENCE. OUR THINKING IS THAT CLOUDS MIGHT NOT TOTALLY BREAK
UP...BUT BECOME SCATTERED (PARTLY CLOUDY)...WITH MORE CLOUDS NORTH
(MOSTLY CLOUDY). THIS WOULD NOT LEAD TO OPTIMAL RADIATIONAL
COOLING...BUT TEMPERATURES WOULD COOL ABOUT 10 DEGREES OR SO. IF THE
CLOUDS WERE TO SPREAD OUT OUR LOW TEMPERATURES WILL BE TOO LOW AS
THEY WOULD NOT FALL MUCH AT ALL.
SO FOR NOW...WENT WITH THE MAV/MET BLEND WHICH WERE VERY CLOSE TO
EACH OTHER. THIS LEAD TO AN OVERNIGHT LOW AROUND 30 LOCALLY...20S
OUTLYING REGIONS.
&&
.SHORT TERM /WEDNESDAY NIGHT THROUGH THURSDAY NIGHT/...
ON WED...ANY MORNING LOW CLOUDS WILL BREAK UP AND WE SHOULD ENJOY A
PERIOD OF SUNSHINE BEFORE HIGH CLOUDS MOVE IN FROM THE SOUTHWEST AS
WARM ADVECTION COMMENCES WITH APPROACHING STORM SYSTEM FROM THE GULF
COAST DURING THE AFTERNOON. IT LOOKS AS THE BULK OF THE RAIN WILL
HOLD OFF UNTIL AFTER 00Z THURSDAY. SO...LOWERED POPS TO SLIGHT
CHANCES SOUTH AND WEST OF THE CAPITAL DISTRICT FOR THE AFTERNOON. AS
FOR MAX TEMPS...WE EXPECT SHALLOW MIXING...ONLY TO 950-925
MB...WHICH...IN COMBINATION WITH INCREASING CLOUDS...SHOULD ALLOW
MAXES TO REACH 45-50 WITHIN THE VALLEYS...AND MAINLY LOWER 40S
ACROSS THE NORTH COUNTRY/SOUTHERN VT. THESE MAXES CONTINUED TO BE A
TOUCH COOLER THAN A MAV/MET MOS BLEND BY A FEW DEGREES. THE ONLY
EXCEPTION MIGHT BE SOME LOWER 50S IN PLACES LIKE BENNINGTON/NORTH
ADAMS DUE TO A DOWNSLOPING SE WIND.
WED NT-THU...POWERFUL LOW LEVEL JET APPROACHES/TRAVERSES THE REGION
LATE WED NT...ALONG WITH STRONG MOISTURE TRANSPORT. THIS WILL
ALLOW FOR RAIN TO DEVELOP QUICKLY IN THE EVENING...AND CONTINUE
OVERNIGHT...WITH A FEW PERIODS OF HEAVY RAIN POSSIBLE...ESP ACROSS
THE WESTERN DACKS...AND S/E FACING SLOPES WITHIN THE CATSKILLS AND
TACONICS. A FEW RUMBLES OF THUNDER CAN NOT BE RULED OUT...ESP ACROSS
SOUTHERN AREAS TOWARD THU AM...GIVEN FORECAST 850 LI'S DIPPING INTO
SLIGHTLY NEGATIVE NUMBERS. SURFACE BASED CAPES REACH ABOUT 100 J/KG
IN A FEW SPOTS EARLY IN THE DAY. FOR NOW...ADDED SLIGHT CHANCE OF
THUNDER WEDNESDAY NIGHT/EARLY THURSDAY. A DRY SLOT ADVANCING
NORTHEASTWARD WILL QUICKLY CUTOFF THE RAINFALL SHORTLY AFTER 12Z
THURSDAY.
THE OTHER MAIN STORY WILL BE THE POTENTIAL FOR STRONG WINDS...ESP
WITHIN CHANNELED N/S ORIENTED VALLEYS WITHIN THE
BERKSHIRES...TACONICS...AND GREENS...WHERE GUSTS COULD APPROACH
ADVISORY LEVELS OF UP TO 50 MPH. WE WILL CONTINUE TO ADDRESS THIS
POTENTIAL IN THE HWOALY. OTHERWISE...WE EXPECT ANY MINS TO OCCUR
EARLY WED NT...WITH TEMPS RISING LATER AT NIGHT AS A STRONG STRONG
S/SE FLOW ENSUES. MAX TEMPS SHOULD THEN OCCUR BY MIDDAY...WHEN
DEEPEST MIXING OCCURS NEAR OR JUST BEHIND COLD FRONT...WITH TEMPS
FALLING THU AFTERNOON. WE HAVE LEANED CLOSE TO THE WARM MET MOS FOR
MAXES...SOARING INTO THE 60S IN THE VALLEYS...AND 50S FOR HIGHER
ELEVATIONS. IF THESE TEMPERATURES PAN OUT...THESE WOULD ECLIPSE
RECORD HIGHS FOR DECEMBER 3. AT ALBANY...OUR RECORD HIGH FOR
DECEMBER 3 IS 58 DEGREES SET IN 1998. KEEP IN MIND...THE MAV NOS ARE
CONSIDERABLY COOLER...ABOUT 15 DEGREES SO! THIS IS BECAUSE THE GFS
TRACKS THE STORM FURTHER EAST...RIGHT OVER ALBANY AND THEN TO THE
EAST. THE NAM CONTINUES TO TRACK WEST AND NORTH OF THE SAINT
LAWRENCE VALLEY. THE EUROPEAN AND CANADIAN MODELS TRACK THE STORM
BETWEEN THE GFS AND NAM...BUT MORE WITH THE NAM WHICH MAKES PHYSICAL
SENSE GIVEN IT IS HARD FOR A STORM TO TRACK RIGHT ACROSS THE SPINE
OF THE APPALACHIANS IN THE ABSENCE OF COLD AIR DAMMING.
ONCE THE COLD FRONT WHIPS ON BY...TEMPERATURES WILL FALL DURING THE
AFTERNOON...ESPECIALLY NORTHWEST OF ALBANY WHERE THEY WILL FALL INTO
THE 40S BEFORE DARK....DOWN INTO THE 50S IN THE HUDSON VALLEY AND
POINTS SOUTHEAST. THEREFORE WE DID NOT FOLLOW THE NORMAL DIURNAL
TREND ONCE AGAIN.
AS IT TURNS COLDER...THE LAKE RESPONSE WILL SET UP AGAIN...INITIALLY
WITH LAKE EFFECT SHOWERS OFF ONTARIO...BUT THESE WILL QUICKLY TO
SNOW SHOWERS BY THURSDAY NIGHT. INITIALLY THEY WILL IMPACT THE
ADIRONDACKS...THEN SLIP INTO THE PORTIONS OF THE MOHAWK VALLEY.
THE AIR MASS BEHIND THIS BRIEF WARMUP IS STILL NOT OF ARCTIC
ORIGIN...BUT WILL RETURN TEMPERATURES TO SEASONABLE LEVELS BY LATE
THURSDAY NIGHT INTO FRIDAY. WITH A W FLOW OFF ONTARIO...LAKE EFFECT
SNOW SHOWERS WILL PERSIST. HOWEVER...WITH NO BIG DISTURBANCES AND
THE FACT THAT THE AIR IS NOT ALL THAT COLD...WE ARE NOT LOOKING AT A
LARGE EVENT IN OUR AREA. NEVERTHELESS AREAS IN THE DACKS COULD PICK
UP A COUPLE MORE INCHES OF SNOWFALL.
&&
.LONG TERM /FRIDAY THROUGH TUESDAY/...
ASIDE FROM LAKE EFFECT SNOW...MAINLY IMPACTING OUR DACKS AND
NORTHERN MOHAWK VALLEY...THE REST OF THE AREA WILL BE DRY AND
SEASONABLY CHILLY FRIDAY INTO SATURDAY. HIGH TEMPERATURES ON FRIDAY
WILL BE 35 TO AROUND 40 IN VALLEY LOCATIONS...30-35 HIGHER TERRAIN
AND NORTH. THERE WILL LIMITED SUNSHINE...WITH MORE IN THE MID HUDSON
VALLEY. THE CLOUDIEST PLACES SHOULD BE TO THE LEE OF LAKE ONTARIO
WHERE THE SNOW SHOWERS WILL BE.
AS WE HEAD INTO SATURDAY...WE WILL CONTINUE TO MONITOR A POSSIBLE
COASTAL STORM THAT IS FORECAST TO FORM ALONG THE STATIONARY FRONT
DISPLACED WELL TO OUR SOUTH. EARLIER...THE 06Z GFS INDICATED THIS
LOW PRESSURE COULD BRING SOME SNOW TO OUR REGION...PERHAPS
SIGNIFICANT SNOWFALL JUST TO OUR EAST AS IT TRACKS UP THE COAST
ABOUT 100 MILES OF THE BENCHMARK (EASTERN TIP OF LONG ISLAND).
HOWEVER...THIS WAS CLEARLY AN OUTLIER AS THE CURRENT
EUROPEAN/CANADIAN AND NOW EVEN THE 12Z GFS INDICATE A NEAR MISS WITH
THIS STORM (WHICH IS MERELY AN OPEN WAVE) NOT A DEEPLY DEVELOPED OR
STACKED STORM. WHAT COULD END UP HAPPENING...IS AN INVERTED TROUGH
COULD POOL LOW LEVEL MOISTURE AWAY FROM THE STORM. WE HAVE SEEN THIS
SCENARIO SEVERAL TIMES THIS PAST FALL. THIS MIGHT BRING SOME LIGHT
SNOW TO OUR REGION. FOR NOW THOUGH...WE DOWNPLAYED THIS
THREAT...ONLY GOING SLIGHT CHANCES IN THE GRIDS SATURDAY INTO
SATURDAY NIGHT. TEMPERATURES LOOK COLD ENOUGH FOR SNOW...ALTHOUGH IF
IT WERE VERY LIGHT...THEN IT MIGHT MIX WITH RAIN THE VALLEYS DURING
SATURDAY AFTERNOON.
SNOWSTORM OR NOT (LIKELY NOT) THIS STORM WILL DEEPEN OUT IN THE GULF
OF MAINE...PULLING A BIT MORE COLD AIR OUR WAY WITH H850
TEMPERATURES FORECASTED TO REACH -10C ACROSS MOST OF OUR AREA SUNDAY
INTO MONDAY. IT WILL TURN BRISK AND COLD WITH MORE LAKE EFFECT SNOW
SHOWERS FIRING UP...ACROSS THE MOHAWK VALLEY THIS GO ROUND (WITH A
MORE NW FLOW AS OPPOSED TO WESTERLY). TEMPERATURES MIGHT ACTUALLY
DIP A BIT BELOW NORMAL FOR A CHANGE SUNDAY INTO MONDAY...STAYING IN
THE 30S LOCALLY AND SOUTH...20S NORTH.
BY TUESDAY...A LARGE ANTICYCLONE WILL BUILD INTO THE REGION AND THEN
DRIFT EAST. TEMPERATURES WILL MODERATE BACK TO NEAR NORMAL
LEVELS...GENERALLY IN THE 30S TO AROUND 40 FOR HIGH TEMPERATURES.
CLOUDS WILL INCREASE IN RESPONSE TO THE NEXT IMPENDING LOW PRESSURE
AREA...POISED AT THIS POINT...TO TRACK OUR WEST ONCE AGAIN.
&&
.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
LAKE EFFECT MOISTURE CONTINUES TO STREAM ACROSS CENTRAL AND
NORTHERN NY...BUT SATELLITE TRENDS SHOW SOEM DOWNSLOPE EFFECTS ARE
PROVIDING SOME BREAKS IN HUDSON VALLEY AREAS. THE CLOUDS ARE ALSO
SLOWLY ERODING FROM SOUTH TO NORTH...BUT VERY SLOWLY...AND IT WILL
TAKE AT LEAST TO 03Z FOR KALB TO GO SCATTERED...AND 09Z-11Z FOR
KGFL. ONCE THE CLOUD DECK DISSIPATES...SOME FOG IS POSSIBLE AT
KGFL FOR A FEW HOURS AROUND SUNRISE. KPOU MAY SEE SOME FOG AFTER
09Z AS WELL. ANY FOG SHOULD BE PREDOMINANTLY MVFR. THERE SHOULD BE
JUST SCATTERED CLOUDS MOST OF THE DAY TOMORROW...THEN HIGH CLOUDS
AT AROUND 25000 FEET WILL SPREAD ACROSS THE REGION LATER IN THE
MORNING AND THROUGH THE AFTERNOON.
WINDS TONIGHT WILL BE SOUTH TO SOUTHWEST AT 6 KT OR LESS...AND
CONTINUE SOUTH TO SOUTHWEST AT LESS THAN 10 KT TOMORROW.
OUTLOOK...
WED NIGHT-...MVFR-IFR IN RAIN.
THU-FRI NGT...VFR...NO SIG WX.
SAT-SAT NGT...VFR...CHC MVFR -SN.
SUN...VFR...NO SIG WX.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS EXPECTED THROUGH WEDNESDAY.
A SYSTEM APPROACHING FROM THE OHIO VALLEY IS FORECAST TO BRING A
WIDESPREAD RAINFALL...WITH TOTAL RAINFALL OF ONE TO ONE AND A HALF
INCHES LIKELY...WEDNESDAY NIGHT AND EARLY THURSDAY. THIS RAINFALL
WILL CAUSE SIGNIFICANT RISES ON THE RIVERS BUT THEY WILL LIKELY STOP
SHORT OF FLOOD STAGE.
MODELS INDICATE THAT MOST OF THE RAIN WILL OCCUR IN THE MIDDLE OF
THE NIGHT...BETWEEN MIDNIGHT WEDNESDAY AND AROUND 7AM THURSDAY.
THIS HIGH INTENSITY RAINFALL MAY CAUSE SOME SMALL STREAMS TO
FLOOD EARLY THURSDAY...AND WITH FALLEN LEAVES STILL AROUND MAY ALSO
RESULT IN SOME DRAINAGE PROBLEMS ON ROADS AND PARKING AREAS. AN
EMBEDDED THUNDERSTORM OR TWO IS POSSIBLE.
SOME LAKE EFFECT SNOW MAY OCCUR THURSDAY NIGHT AND FRIDAY IN THE
WAKE OF THE STORM AS COLDER AIR MOVES BACK IN...BUT OTHERWISE IT
WILL BE DRY. MAINLY DRY WEATHER IS EXPECTED THE REMAINDER OF THE
PERIOD INTO THE WEEKEND.
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.
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.
&&
$$
AVIATION...NAS
