FXUS61 KALY 011155
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
655 AM EST TUE DEC 1 2009
.SYNOPSIS...
A WEAK LOW PRESSURE SYSTEM WILL APPROACH FROM THE WEST
TODAY...BRINGING CLOUDS...ALONG WITH SCATTERED SNOW AND RAIN SHOWERS
TO THE REGION. A RIDGE OF HIGH PRESSURE WILL BUILD INTO THE REGION
TONIGHT AND WEDNESDAY...PROVIDING FAIR AND MILD CONDITIONS. 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 /UNTIL 6 PM THIS EVENING/...
AS OF 4 AM EST...A WEAK SHORTWAVE RIDGE CONTINUES TO SLIDE E ACROSS
THE REGION...BRINGING A PERIOD OF MOSTLY CLEAR SKIES...AND LIGHT TO
CALM WIND. THIS HAS ALLOWED TEMPS TO DROP QUICKLY INTO THE MID/UPPER
20S IN MOST VALLEY LOCALES...WITH SOME TEENS TO LOWER 20S ACROSS THE
NORTH COUNTRY. MID LEVEL CLOUDS ARE QUICKLY ADVANCING E FROM THE
GREAT LAKES...IN RESPONSE TO STRENGTHENING WARM ADVECTION TO THE E
OF A SFC LOW...CURRENTLY ACROSS THE NORTHERN GREAT LAKES. RATHER
STRONG MID/UPPER LEVEL DYNAMICS...IN ADDITION TO WARMTH/MOISTURE
FROM THE LAKES WAS CONTRIBUTING TO A BLOSSOMING AREA OF
PRECIP...MAINLY SNOW...ACROSS WESTERN NY AND THE EASTERN GREAT
LAKES. WE EXPECT THIS FEATURE TO CONTINUE SLIDING E...ALBEIT IN A
WEAKENING STATE LATER THIS MORNING INTO THE AFTERNOON...BRINGING
SCATTERED TO NUMEROUS SHOWERS OF SNOW AND RAIN.
WE EXPECT SNOW SHOWERS TO BE MOST NUMEROUS ACROSS THE SW
DACKS...WHERE AFOREMENTIONED UPPER LEVEL DYNAMICS...MORE AMPLE
MOISTURE AND INSTABILITY WILL ENHANCE PRECIP. THUS...WE EXPECT
OCCASIONAL SNOW SHOWERS IN THIS REGION...WHERE 1-3 INCHES OF ACCUM
IS POSSIBLE. THERE COULD BE A FEW HEAVIER BURSTS OF SNOW FROM MID
MORNING INTO THE EARLY AFTERNOON HOURS IN THIS REGION. FURTHER
S/E...WE EXPECT SCATTERED TO NUMEROUS SNOW SHOWERS FROM LATE MORNING
INTO THE MID AFTERNOON HOURS...WITH SOME RAIN MIXING IN WITHIN THE
VALLEY LOCALES...AS BOUNDARY LAYER TEMPS WARM THROUGH A DEEP ENOUGH
LAYER TO MELT SOME OF THE SNOW. WITHIN THIS REGION...A BRIEF DUSTING
IS POSSIBLE ACROSS HIGHER ELEVATIONS WITHIN THE SCHOHARIE
VALLEY/WESTERN MOHAWK VALLEY...AS WELL AS ACROSS W FACING HIGHER
ELEVATIONS WITHIN THE NORTHERN TACONICS...SOUTHERN GREENS AND
NORTHERN BERKSHIRES. FURTHER S/E...ONLY SOME SPRINKLES OR FLURRIES
ARE EXPECTED...ALTHOUGH SNOW SHOWERS ARE MORE LIKELY ACROSS THE
HIGHER ELEVATIONS WITHIN THE EASTERN CATSKILLS.
FOR MAX TEMPS...WE EXPECT FAIRLY DEEP MIXING TO AROUND 850-875 MB
WITH THE PASSAGE OF MID/UPPER LEVEL COLD POOL. HOWEVER...THIS SHOULD
BE MITIGATED SOMEWHAT BY CLOUDS AND POSSIBLE PRECIP. THUS...WE HAVE
GENERALLY SIDED CLOSE TO...OR A TAD BELOW A MAV/MET MOS BLEND...WITH
LOWER 40S EXPECTED WITHIN THE HUDSON RIVER VALLEY...EXCEPT FOR SOME
MID 40S WITHIN THE MID HUDSON VALLEY...AND MAINLY 30S ACROSS HIGHER
ELEVATIONS.
&&
.SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/...
TONIGHT...SOME LINGERING SNOW SHOWERS/FLURRIES ARE POSSIBLE
EARLY...ESP ACROSS THE SW DACKS...AND HIGHER...WEST FACING AREAS
WITHIN SW VT. THEREAFTER...THE MAIN FORECAST CHALLENGE WILL BE THE
EXTENT OF LINGERING CLOUDS...AND MIN TEMPS. WE EXPECT THE INVERSION
TO LOWER RAPIDLY OVERNIGHT...WHICH...IN COMBINATION WITH W/NW WIND
FLOW WITHIN THE 925-850 MB LAYER CROSSING THE GREAT LAKES...MAY TRAP
MOISTURE BELOW...RESULTING IN AREAS OF CLOUDS. MODELS OFTEN HAVE A
DIFFICULT TIME WITH SUCH MOISTURE/CLOUDS...TENDING TO CLEAR THEM OUT
TOO QUICKLY. WE THEREFORE HAVE KEPT AT LEAST SOME CLOUDS FOR
NORTHERN AND CENTRAL AREAS THROUGH MIDNIGHT...POSSIBLY PERSISTING
ACROSS NORTHERN AREAS THROUGH DAYBREAK. THIS SHOULD RESULT IN
SLIGHTLY MILDER TEMPS THAN THIS MORNING...AND HAVE SIDED WITH THE
WARMER MET MOS FOR MINS...WITH THE EXCEPTION OF SOUTHERN
AREAS...WHERE SKIES ARE MORE LIKELY TO CLEAR EARLIER...ALLOWING MINS
TO FALL INTO THE MID/UPPER 20S.
WED...ANY MORNING LOW CLOUDS SHOULD BRIEFLY BREAK...ONLY TO YIELD TO
THICKENING HIGH/MID LEVEL CLOUDS FROM THE SOUTHWEST AS WARM
ADVECTION COMMENCES WITH APPROACHING STORM SYSTEM FROM THE GULF
COAST. SOME LIGHT RAIN COULD DEVELOP TOWARD EVENING...ESP FOR AREAS
S AND W OF THE CAPITAL REGION...WHERE CHC POPS ARE INDICATED. 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 ARE GENERALLY
COOLER THAN A MAV/MET MOS BLEND BY A FEW DEGREES.
WED NT-THU...POWERFUL LOW LEVEL JET APPROACHES/TRAVERSES THE REGION
LATE WED NT...ALONG WITH STRONG MOISTURE TRANSPORT. THIS SHOULD
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. 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. WE WILL ADDRESS THIS POTENTIAL IN
THE HWOALY. OTHERWISE...WE EXPECT ANY MINS TO OCCUR EARLY WED
NT...WITH TEMPS RISING RAPIDLY LATER AT NIGHT GIVEN THE STRONG S/SE
FLOW. MAX TEMPS SHOULD THEN OCCUR THU MORNING...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...YIELDING LOWER/MID 60S WITHIN VALLEYS...AND 50S FOR HIGHER
ELEVATIONS...WITH TEMPS THEN FALLING THROUGH THE 50S AND 40S DURING
THE AFTERNOON. AS FOR RAIN...WE EXPECT STEADY RAIN TO BECOME MORE
SHOWERY BY SUNRISE THU...WITH SHOWERS TAPERING RAPIDLY FROM W TO E
ONCE COLD FRONTAL PASSAGE OCCURS. WINDS MAY ONCE AGAIN APPROACH
ADVISORY LEVELS BEHIND THIS FRONT...GIVEN STRONG SFC PRESSURE RISES
AND INTENSIFYING COLD ADVECTION DURING THE AFTERNOON HOURS.
&&
.LONG TERM /THURSDAY NIGHT THROUGH MONDAY/...
THU NIGHT INTO SAT...IN THE WAKE OF THE SURFACE LOW STRONG COLD AIR
ADVECTION TAKES PLACE WITH FAIRLY STRONG CYCLONIC FLOW AND AS A
RESULT SOME LAKE EFFECT SNOWS ARE POSSIBLE ESPECIALLY ACROSS THE
WESTERN ADIRONDACKS AND NORTHERN PORTIONS OF THE MOHAWK VALLEY. THIS
LOOKS TO BE A FAIRLY PROLONGED LAKE EFFECT EVENT AS LAKE ONTARIO
TEMPS WILL LIKELY STILL BE IN THE MID 40S AND H8 TEMPS IN THIS AREA
LOOK TO DROP TO AROUND -10 C LATE THURSDAY NIGHT AND REMAIN AROUND
-10 C ON FRIDAY AND DROP TO AROUND -12 C ON FRIDAY NIGHT AND
SATURDAY. OUTSIDE OF THE LAKE EFFECT BAND MAINLY DRY BUT COOL
WEATHER IS EXPECTED DURING THIS PERIOD. HAVE LOWS THURSDAY NIGHT IN
THE MID 20S TO LOWER 30S...HIGHS FRIDAY IN THE MID 30S TO MID
40S...LOWS FRIDAY NIGHT IN THE UPPER TEENS TO MID 20S AND HIGHS ON
SATURDAY IN THE 30S TO AROUND 40.
SATURDAY NIGHT THROUGH SUNDAY NIGHT LOOKS TO BE MAINLY DRY AS THE
LOW LEVEL FLOW BECOMES ANTICYCLONIC WHICH SHOULD CAUSE THE LAKE
EFFECT ACTIVITY TO WEAKEN WITH A RIDGE OF HIGH PRESSURE BUILDING IN
AT THE SURFACE. H8 TEMPS LOOK TO BOTTOM OUT ACROSS FA AT AROUND -12
TO -13 C EARLY SUNDAY MORNING AND THEN SLOWLY RISE TO -7 TO -11 C BY
MONDAY MORNING. HAVE LOWS SATURDAY NIGHT IN THE MID TEENS TO MID
20S...HIGHS ON SUNDAY IN THE UPPER 20S TO LOWER 40S AND LOWS SUNDAY
NIGHT IN THE MID TEENS TO MID 20S.
ON MONDAY EXPECT CLOUDS TO INCREASE AGAIN AHEAD OF ANOTHER CLIPPER
TYPE SYSTEM MOVING INTO THE EASTERN GREAT LAKES WITH A CHANCE OF
SNOW SHOWERS ACROSS THE SOUTHERN ADIRONDACKS AND MOHAWK VALLEY.
HIGHS MONDAY LOOK TO BE IN THE UPPER 20S TO AROUND 40.
&&
.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
CLEAR SKIES WILL GIVE WAY TO SCATTERED LOW CLOUDS AND BROKEN MID
LEVEL CLOUDS WITH VFR CONDITIONS OVER THE NEXT SEVERAL HOURS AND
THEN LATE THIS MORNING BROKEN STRATOCUMULUS WITH MVFR CIGS AND
SOME FLURRIES OR LIGHT SNOW SHOWERS ARE EXPECTED RESULTING FROM A
WEAK TROF OF LOW PRESSURE IN COMBINATION WITH A WINDEX/LAKE
ENHANCED EVENT. AT THIS POINT HAVE JUST PUT VCSH IN THE TAFS
FOR KGFL AND KALB FROM LATER THIS MORNING THROUGH MUCH OF THIS
AFTERNOON AS VERY DRY AIR IN PLACE IN HUDSON VALLEY AT THE MOMENT
AND MUCH OF THE PRECIPITATION MAY DRY UP BEFORE REACHING THE
HUDSON VALLEY. AFTER SUNSET SKIES ARE EXPECTED TO CLEAR ONCE
AGAIN. HAVE LEFT ANY MENTION OF FLURRIES AND MVFR CIGS OUT OF THE
TAF FOR KPOU AS ACTIVITY NOT EXPECTED TO GET THAT FAR SOUTH.
LIGHT AND VARIABLE WINDS WILL BECOME SOUTH AT 4 TO 8 KTS IN THE
NEXT SEVERAL HOURS AND THEN SOUTHWEST TO WEST AT 6 TO 8 KTS LATER
THIS MORNING THROUGH THIS AFTERNOON AND THEN DIMINISH THIS
EVENING.
OUTLOOK...
TUE NIGHT-WED...VFR. NO SIG WX.
WED NIGHT-THU...MVFR-IFR IN RAIN.
FRI-SAT...VFR...CHC OF -SHRA/-SHSN.
&&
.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH WEDNESDAY. SOME SHOWERS OF
SNOW AND RAIN ARE EXPECTED TODAY THROUGH THIS EVENING IN ASSOCIATION
WITH A PASSING UPPER LEVEL DISTURBANCE. LIQUID EQUIVALENT AMOUNTS
SHOULD RANGE FROM ONE TENTH...TO ONE QUARTER OF AN INCH ACROSS THE
WESTERN ADIRONDACKS...WITH LESS THAN ONE TENTH OF AN INCH EXPECTED
ELSEWHERE.
A SYSTEM APPROACHING FROM THE OHIO VALLEY MAY BRING A WIDESPREAD
RAINFALL...WITH TOTAL RAINFALL LIKELY EXCEEDING AN INCH...WEDNESDAY
NIGHT AND EARLY THURSDAY. ALTHOUGH TOTAL FORECAST RAINFALL DOESN'T
APPEAR TO BE ENOUGH TO CAUSE WIDESPREAD FLOODING...DETERMINISTIC AND
ENSEMBLE GUIDANCE INDICATE THAT MOST OF THE RAIN WILL FALL IN A 6 TO
12 HOUR PERIOD. HIGH INTENSITY RAINFALL MAY CAUSE SOME URBAN AND
SMALL STREAM FLOODING ON THURSDAY MORNING. DRY...COLD WEATHER WILL
FOLLOW WITH THE BEST CHANCE FOR MORE PRECIPITATION ON SATURDAY.
PRECIPITATION TYPE ON SATURDAY LOOKS TO BE SNOW. STREAMS IN THE
ADIRONDACKS MAY START TO SEE SOME RIVER ICE FORMATION EARLY NEXT
WEEK.
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...KL
NEAR TERM...KL
SHORT TERM...KL
LONG TERM...11
AVIATION...11
HYDROLOGY...SND/KL
