FXUS61 KALY 261310
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
805 AM EST SAT DEC 26 2009
.SYNOPSIS...
AN OCCLUDED FRONT WILL LIFT NORTHEAST THROUGH THE MID ATLANTIC
STATES AND NEW YORK TODAY AND TONIGHT. WEAK LOW PRESSURE WILL MOVE
FROM THE VIRGINIA CAPES TO LONG ISLAND. THIS SYSTEM WILL BRING A
WINTRY MIX TO THE REGION...BEFORE CHANGING TO RAIN DURING TODAY.
SUNDAY THE REGION WILL BE BETWEEN SYSTEMS AS SOME DRIER AIR WORKS
IN FROM THE SOUTHWEST. SUNDAY NIGHT AND MONDAY A MID LEVEL
DISTURBANCE AND A COLD FRONT WILL MOVE ACROSS THE REGION BRINGING
SNOW SHOWERS AND IN ITS WAKE USHER IN MUCH COLDER AIR. HIGH
PRESSURE WILL BUILD FROM THE MIDWEST TO THE NORTHEAST
MIDWEEK...BEFORE THE NEXT STORM SYSTEM ORGANIZES ALONG THE
CAROLINA COAST TO BRING A THREAT OF MORE WINTER WEATHER TO END THE
YEAR.
&&
.NEAR TERM /THROUGH TONIGHT/...
...FREEZING RAIN ADVISORY CANCELLED FOR EASTERN ULSTER/EASTERN
GREENE...WESTERN DUTCHESS/WESTERN COLUMBIA COS...
...ALL OTHER ADVISORIES REMAIN UNCHANGED...
AS OF 8 AM EST...TEMPERATURES HAVE RISEN ABOVE FREEZING ACROSS LOWER
ELEVATIONS WITHIN THE MID HUDSON VALLEY REGION...ACCORDING TO LATEST
MADIS SFC OBS AND METARS. THUS...IN THESE REGIONS...ANY PATCHY LIGHT
PRECIP SHOULD BE IN THE FORM OF LIGHT RAIN/DRIZZLE...AND THUS THE
CANCELLATION FOR THIS PORTION OF THE ADV.
ELSEWHERE...ONLY PATCHY LIGHT PRECIP REMAINS...GIVEN MID LEVEL
DRYING AND ONLY WEAK ISENTROPIC LIFT REMAINING. THUS...EXPECT ONLY
INTERMITTENT PRECIP THROUGH THIS MORNING...WITH TEMPS REMAINING AT
OR BELOW FREEZING...WILL BE MAINLY FREEZING RAIN/DRIZZLE IN REMAIN
ADV AREAS...ALTHOUGH SOME SLEET COULD OCCUR WITHIN ANY ISOLATED
HEAVIER PRECIP ELEMENTS THAT DEVELOP.
PREVIOUS DISCUSSION FOLLOWS...
RATHER COMPLEX SITUATION TODAY. LARGE 500HPA CUTOFF OVER MIDWEST
WITH DECAYING SFC LOW OVER LK SUPERIOR. OCCLUDED FRONT EXTENDS FM
THIS LOW TO NR ERI-ORF. SFC LOW NEAR VA CAPES ORGANIZING AT TRIPLE
POINT. 1036HPA SFC HIGH OVER GULF OF ST LAWRENCE. THIS
CONFIGURATION WILL DRIVE THE MAJOR FEATURES DURING THE NEAR TERM.
FIRST BAND OF PCPN AHEAD OF THIS FRONT IS LIFTING NE THRU RGN AND
HAS PRODUCED MAINLY SNOW AND SLEET AND SOME ZR. THE COMPLEX
FRONTAL SYSTEM WAS RESPONSIBLE FOR CREATING A STRATIFIED/LAYERING
OF ABOVE AND BELOW FREEZING LAYERS. OVER THE NEXT FEW HOURS THE
UPPER LAYERS DRY OUT OR WARM SUCH THAT THERE IS LITTLE OR NO ICE
IN THE CLOUDS...WHILE THE LOWER LAYERS REMAIN BLO FREEZING. THE
MAIN PCPN THREAT WITH THIS BAND OVER RGN ATTM IS AND HAS BEEN A
WINTRY MIX DOMINATED BY SNOW/SLEET. BUT BEHIND IT...MAIN THREAT WILL
BE ZR/ZL MUCH OF TODAY. THIS THREAT WILL ONLY END WHEN TEMPS RISE
SUFFICIENTLY. HWVR MUCH OF TODAY AMOUNTS WILL BE LIGHT OR VERY
LIGHT.
LEFT THE SUITE OF ADVISORIES IN PLACE WHOSE MAIN DIFFERENCES
REVOLVED AROUND ENDING TIMES OF THE ZR/ZL MIX. SIMPLIFICATION OF
THE PACKAGE SHOULD BE POSSIBLE ONCE THE PTYPE IS LARGELY ZR/ZL IN
MANY AREAS AND ONLY RN IN S.
MEANWHILE DURING THE AFTN SFC LOW NOW NEAR ORF...WILL MOVE N TO S
NJ THIS EVENING AND GFL BY MORNING. WHILE THIS LOW IS ONLY AROUND
1010HPA ITS PROXIMITY TO A 1036 SFC HIGH WILL RESULT IN A 10HPA
GRADIENT ACROSS FCA MUCH OF TODAY AND THIS EVENING. CURRENT VWP
ALREADY SHOWS 20KTS AT 2KFT...35KTS AT 3KFT. WRF/NAM SHOWED 925HPA
WINDS AT THESE LEVELS INCREASING IN EXCESS OF 40KTS DEVELOPING
DURING THE DAY. PVS SHIFT HAD ISSUED WIND ADVISORY. WINDS WILL
FIRST AND MAINLY IMPACT THE HIGHER TRRN. WHILE WE KEPT THIS
ADVISORY...WINDS OVER HIR TRRN ARE LIKELY TO REACH THE CRITERIA IN
GUSTS DURING THIS AFTN...SO MOVED UP ADVISORY START TIME TO 1PM
THIS AFTN FROM 6PM.
WHILE PCPN THIS MORNING AFTER THE PASSAGE OF THE INITIAL BAND WILL
BE SPOTTY AND LIGHT...ITS INTENSITY SHOULD INCR DURING THE AFTN AS
THE SFC LOW MOVES N ALONG THE SEABOARD...AND IT ACTS TO INCR
MOISTURE INFLO INTO THE REGION AHEAD OF THE OCCLUDED FRONT.
FORTUNATELY IS WILL ALSO BRING SOME WAA AND IN TIME CHANGE THE
MIX MESS TO RAIN.
&&
.SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/...
ON SUNDAY...THE UPPER TROF AND CUTOFF LOW WILL MOVE EAST FROM THE
MISSISSIPPI VALLEY INTO THE GREAT LAKES STATES. THE SURFACE LOW
ASSOCIATED WITH THE UPPER LOW WILL LIFT NORTH INTO CANADA WHILE A
SECOND LOW OFF THE COAST WILL INTENSIFY AS IT MOVES TO THE COAST
OF MAINE BY SUNDAY EVENING. AS THE PRIMARY LOW MOVES
NORTH...SOMEWHAT DRIER AIR WILL WORK ITS WAY INTO THE REGION AS A
WEAK SURFACE RIDGE MOVES ACROSS THE REGION...AND WE MIGHT SEE A
FEW HOURS OF SUNSHINE...ESPECIALLY SOUTH AND EAST OF ALBANY. WENT
WITH A BLEND OF THE MAV/MOS AND MET/MOS FOR HIGH TEMPERATURES
WHICH WILL RANGE FROM THE LOW AND MID 30S IN THE ADIRONDACKS TO
THE MID 40S IN THE HUDSON VALLEY OF NEW YORK AND ADJACENT AREAS OF
NEW ENGLAND.
ON SUNDAY NIGHT...THE UPPER TROF...AND CUTOFF LOW...MOVES
OVER UPSTATE NEW YORK...RESULTING IN A RETURN TO CLOUDS AND
SNOW SHOWERS...ESPECIALLY WEST OF THE HUDSON VALLEY AND THE
HIGHER TERRAIN OF SOUTHERN VERMONT. COOLER AIR WILL MOVE INTO
THE REGION...WITH LOWS MONDAY MORNING IN THE 20S.
ON MONDAY THE UPPER TROF REMAINS OVER THE REGION AS THE CUTOFF
LOW LIFTS OUT...AND THE ARCTIC FRONT SWEEPS THROUGH THE REGION
DURING THE LATE AFTERNOON AND EVENING. IT WILL BE COOLER WITH
HIGHS FROM THE UPPER 20S ACROSS THE ADIRONDACKS TO THE UPPER
30S IN THE HUDSON VALLEY SOUTH OF ALBANY. FOR THE HIGHS MONDAY
USED A BLEND OF THE MAV/MOS AND MET/MOS. WE ARE LOOKING AT A
NUISANCE TYPE SNOW MONDAY WITH ONE TO TWO INCHES ACROSS THE
REGION...WITH THE HIGHER AMOUNTS IN THE CATSKILLS AND THE
WESTERN MOHAWK VALLEY.
THE ARCTIC FRONT OPENS THE FREEZER DOOR AND TEMPERATURES WILL
PLUMMET WITH LOWS TUESDAY MORNING FROM NEAR ZERO OVER THE
ADIRONDACKS TO THE MID AND UPPER TEENS IN THE HUDSON VALLEY
FROM ALBANY SOUTH. IT WILL BE WINDY MONDAY NIGHT AND WIND
CHILL MAY BECOME A CONCERN ACROSS THE ADIRONDACKS. FOR POPS
WILL BE LOOKING AT CHANCE POPS EXCEPT FOR THE HUDSON VALLEY
AND THE LITCHFIELD HILLS WHERE WE WENT WITH SLIGHT CHANCE
POPS. QPFS AND SNOW AMOUNTS ARE VERY LIGHT AS LITTLE MOISTURE
IS AVAILABLE.
&&
.LONG TERM /TUESDAY THROUGH FRIDAY/...
ARCTIC AIR POURS INTO THE REGION TUESDAY AS HIGH PRESSURE MOVES
INTO THE REGION FROM THE OHIO VALLEY. 850 HPA TEMPERATURES TUESDAY
MORNING ARE FORECAST TO BE MINUS 22 TO MINUS 26 DEGREES ACROSS
MOST OF UPSTATE NEW YORK. THE GRADIENT BETWEEN THE LOW IN EASTERN
CANADA AND THE HIGH OVER THE OHIO VALLEY WILL RESULT IN GUSTY
NORTHWESTERLY WINDS...WHICH WILL BRING THE COLD AIR OVER LAKE
ONTARIO...AND POSSIBLY OVER PART OF GEORGIAN BAY AS WELL...WHICH
WILL RESULT IN CLOUDS AND SNOW SHOWERS DOWNWIND FROM LAKE ONTARIO.
HIGHS TUESDAY WILL RANGE FROM THE TEENS IN THE ADIRONDACKS TO
NEAR 30 IN THE LOWER HUDSON AND HOUSATONIC VALLEYS. ASIDE FROM
THE PLUME OF LAKE EFFECT THE REST OF THE REGION SHOULD HAVE
PARTLY TO MOSTLY SUNNY SKIES. AS THE HIGH MOVES OVER THE REGION
LATE TUESDAY NIGHT AND WEDNESDAY THE WINDS WILL DIMINISH...AND
TEMPERATURES WILL PLUMMET TO BELOW ZERO OVER THE ADIRONDACKS AND
SOUTHERN VERMONT...WITH LOWS IN THE SINGLE DIGITS IN THE ALBANY
AREA AND NEAR 10 IN THE HUDSON VALLEY SOUTH OF ALBANY.
A WEAK RIDGE MOVES ACROSS THE REGION WEDNESDAY WITH TEMPERATURES
MODERATING SOME. DRY WEATHER IS FORECAST...WITH PARTLY SUNNY SKIES
NORTH AND MOSTLY SUNNY SKIES SOUTH. HIGHS WILL RANGE FROM NEAR
20 NORTH TO THE LOW 30S SOUTH.
SKIES CLOUD UP WEDNESDAY NIGHT AS A BROAD TROF AND ASSOCIATED
SURFACE LOW MOVE EAST ACROSS SOUTHERN CANADA BRINGING WARMTH
AND MOISTURE INTO THE REGION OVER THE COLDER AIR CLOSE TO THE
SURFACE. LOWS WILL BE FROM NEAR ZERO NORTH TO THE UPPER TEENS
SOUTH.
THURSDAY WILL FEATURE A CHANCE OF SNOW SHOWERS MOSTLY NORTH
AND WEST OF ALBANY AS THE SURFACE LOW APPROACHES THE REGION...
WHILE A SECOND SURFACE LOW MOVES NORTH ALONG THE EAST COAST.
THE COASTAL LOW IS FORECAST TO TURN EAST OUT TO SEA...WITH
CHANCE POPS FOR LIGHT SNOW ACROSS THE REGION FROM THE PRIMARY
LOW. THE GOOD NEWS IS THE WARM TONGUE REMAINS SOUTH AND EAST
OF THE REGION...SO WE ARE NOT LOOKING AT A FREEZING RAIN
SITUATION FOR NEW YEARS EVE.
FOR NEW YEARS DAY...WE ARE LOOKING AT UNSETTLED WEATHER AS
WITH A FRONT STALLING SOUTH OF THE REGION. CHANCE POPS AND
SEASONABLE WITH HIGHS FROM THE UPPER 20S TO THE MID 30S.
&&
.AVIATION /13Z SATURDAY THROUGH WEDNESDAY/...
AN AREA OF ISENTROPIC LIFT AHEAD OF AN OCCLUDED FRONT IS
PRODUCING A BAND OF PRECIPITATION WHICH IS MOVING ACROSS THE
AREA AT THIS TIME. THIS AREA IS PRODUCING A VARIETY OF
PRECIPITATION TYPES OVER THE REGION WITH SNOW MIXED WITH SLEET
THE MOST COMMON...BUT RAIN IN MID HUDSON VALLY...AND FREEZING RAIN
IN WESTERN MOHAWK VALLY AND WESTERN ADIRONDACKS. THE RESULT WILL
BE WIDESPREAD IFR TILL MORNING.
THIS FRONT IS DECELERATING...BUT THIS FIRST AREA OF PRECIPITATION
WILL LIFT NORTHEAST OF REGION 12-15UTC...AND LEAVE THE OCCLUDED
FRONT FM ERI-ORF. WITH DEVELOPING COASTAL LOW OVER THE VIRGINIA
CAPES SOUTHEAST INFLOW OF MOISTURE WILL CONTINUE MOST OF THE DAY.
FOR MOST OF THE REGION MVFR.
THE INITIAL LOWER CIGS AND VSBY WILL BE MAINLY THE RESULT OF
PRECIPITATION OVERNIGHT...BUT BY AFTN MOST OF THE ICE IN THE CLOUDS
DISAPPEARS DUE TO MID LEVEL DRYING AND WARMING...AND EVEN THOUGH
TEMPS WILL BE BLOW FREEZING IN MANY NORTHERN AREAS...PCPN WILL
BECOME AREA OF DRIZZLE...OR FREEZING DRIZZLE....BEFORE CHANGING TO
ALL RAIN/DRIZZLE LATER IN THE DAY. MOST OF THE DAY WILL HAVE MVFR
CIGS AND VSBY IN THIS SITUATION...BUT AS THE LOW MOVES UP THE
COAST AREAS OF IFR WILL BECOME MORE COMMON IN THE AFTERNOON. IN
ADDITION WHILE THE SFC LOW IS NOT PARTICULARLY STRONG ITS
EXISTENCE AND THE GRADIENT WITH A 1036 HPA HIGH OVER THE
MARITIMES WILL RESULT IN A RATHER STRONG WIND GRADIENT SETTING UP
OVER THE REGION.
WHILE SFC WINDS SHOULD REMAIN LIGHT EASTERLY AROUND 10KTS...WINDS
2-3K FEET WILL BE 15-30KTS AND INCREASE DURING THE DAY TO 25 TO
40KTS WITH LLWS DEVELOPING ACR0SS THE REGION..PARTICULARLY THE N-S
VALLEYS. LATER TAFS WILL PROBABLY INCLUDE LLWS.
OUTLOOK...
SAT NGT...MVFR-IFR WITH -RA.
SUN...VFR...MVFR POSSIBLE WITH CHC -SHRA/-SHSN.
MON...VFR...MVFR POSSIBLE WITH CHC -SHSN.
TUE- WED...VFR...NO SIG WX.
&&
.HYDROLOGY...
NOTE...THE GAGE FOR THE HUDSON RIVER AT WATERFORD /WTFN6/ APPEARS
TO BE WORKING THE LAST TWO DAYS. HOWEVER SINCE MORE COLD IS IN THE
PICTURE...WHICH COULD LEAD TO CONTINUED PROBLEMS...WE WILL
CONTINUE TO SUSPEND THE AHPS GRAPH.
GAGES ON THE MOOSE RIVER AT MCKEEVER...THE SACANDAGA RIVER AT
HOPE...AND THE SCHOHARIE CREEK AT PRATTSVILLE ARE WORKING BUT
READING ABOUT TWO FEET HIGHER DUE TO THE EFFECT OF ICE IN THE
RIVER.
A GRADUAL WARMING TREND IS EXPECTED SUNDAY. HIGHS TODAY WILL
ONLY BE FROM THE UPPER 20S TO THE UPPER 30S...BUT ON SUNDAY
TEMPERATURES ARE EXPECTED TO RISE INTO THE 40S FROM THE HUDSON
VALLEY EASTWARD. A MIX OF SNOW AND SLEET WILL MIX AND TURN TO
RAIN AND SOME SUNSHINE MAY OCCUR IN THE HUDSON VALLEY SUNDAY.
WITH A FLOW OF WARM AIR OFF THE OCEAN THERE IS A POSSIBILITY OF
SUBSTANTIAL RAIN SATURDAY NIGHT. THIS COULD BRING ABOUT SIGNIFICANT
INCREASES IN RIVER FLOWS...WHICH IN TURN COULD BREAK SOME OF THE ICE
LOOSE.
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...FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR CTZ001-013.
NY...FREEZING RAIN ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
NYZ038>041-043-047>054-058-063-083-084.
FREEZING RAIN ADVISORY UNTIL NOON EST TODAY FOR NYZ061-066.
WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 6 AM EST SUNDAY FOR
NYZ054-061-084.
WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR NYZ032-033-
042-082.
MA...FREEZING RAIN ADVISORY UNTIL 3 PM EST THIS AFTERNOON FOR
MAZ001-025.
WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 6 AM EST SUNDAY FOR
MAZ001-025.
VT...WIND ADVISORY FROM 1 PM THIS AFTERNOON TO 6 AM EST SUNDAY FOR
VTZ013-014.
WINTER WEATHER ADVISORY UNTIL 6 AM EST SUNDAY FOR VTZ013>015.
&&
$$
SYNOPSIS...SNYDER
NEAR TERM...KL/SNYDER
SHORT TERM...RCK
LONG TERM...RCK
AVIATION...SNYDER
HYDROLOGY...RCK
