Saratoga County, NY

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Area Forecast Discussion
Issued by NWS Albany, NY

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000
FXUS61 KALY 041119
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
720 AM EDT SUN OCT 4 2009

.SYNOPSIS...
AN UPPER AIR DISTURBANCE WILL BRING SOME SHOWER ACTIVITY TO THE
REGION TODAY ACCOMPANIED BY A COOLER AIR MASS. THIS CHANGE OF AIR
MASS MOVING ACROSS THE WARM WATERS OF THE GREAT LAKES WILL BRING
ABOUT ADDITIONAL SHOWER ACTIVITY FOR THE TERRAIN WEST OF THE
CAPITAL REGION. A NARROW RIDGE OF HIGH PRESSURE WILL BUILD IN ON
TUESDAY BEFORE ANOTHER SURGE OF MOISTURE ARRIVES TUESDAY NIGHT.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
H2O VAPOR IMAGERY THIS MORNING REVEALS A SERIES OF UPSTREAM SHORT
WAVES THAT ARE EXPECTED TO MOVE ACROSS THE REGION TODAY. COMBINE
THIS WITH DAYTIME HEATING WILL HELP STEEPEN THE LOW LEVEL LAPSE
RATES WILL ASSIST WITH SHOWER DEVELOPMENT. HOWEVER...THESE
CONVECTIVE UPDRAFTS MAY BE LIMITED DUE TO THE EXPECTED CAP BETWEEN
500-600MB PER FORECAST NAM/GFS BUFR PROFILES. LATEST EXPERIENTIAL
4KM SPC WRF REFLECTIVITY SUGGESTS SHOWER ACTIVITY DEVELOPS OVER
THE TERRAIN AROUND NOON THEN MIGRATES INTO THE VALLEY AND
REMAINDER OF THE REGION THROUGH THE AFTERNOON. SO CHC-SCT POPS FOR
MOST OF THE REGION.

TEMPERATURES SHOULD PROVE TO BE MILD WITH VALUES 70-75F SOUTH OF
THE CAPITAL REGION...AROUND 70F FOR THE CAPITAL REGION AND MOHAWK
VALLEY WITH 60S ELSEWHERE.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/...
THE UPPER LOW OVER THE GREAT LAKES LIFTS NORTHEAST THIS EVENING
AND WEAKENS/FILLS. THIS FEATURE IS FORECAST TO TRACK ACROSS
NORTHERN NEW ENGLAND ON MONDAY AND EXIT THE CONUS MONDAY NIGHT.
DURING THIS MIGRATION TIME FRAME...COLDER AIR WILL FILTER OVER THE
EASTERN GREAT LAKES WHICH BRINGS THE INCREASED POTENTIAL FOR LAKE
EFFECT ACTIVITY DOWNWIND OF LAKE ONTARIO.

WITH BOUNDARY LAYER QUITE WARM...ALL PRECIP WILL BE OF THE LIQUID
VARIETY. 850MB TEMPS ARE EXPECTED TO DROP BACK INTO THE LOWER
SINGLE DIGITS CELSIUS WHILE LAKE ONTARIO WATER TEMPS ARE AROUND
14C. THIS SETS THE DELTA T VALUES AT OR SLIGHTLY EXCEEDING THE 13C
THRESHOLD FOR LAKE EFFECT ACTIVITY. THE LATEST NCEP MODEL SUITE
HITS THE QPF FIELDS QUITE HARD DOWNWIND OF LAKE ONTARIO BUT INLAND
PENETRATION REMAINS QUESTIONABLE. AT THIS POINT...WE WILL PLACE
THE HIGHER POPS ACROSS THE ADIRONDACKS TONIGHT AND THROUGH MOST OF
MONDAY BEFORE THE MEAN TRAJECTORY FLOW BECOMES MORE NORTHWEST
LATER MONDAY AFTERNOON TAKING ANY BANDS OF SHOWERS SOUTHWARD
TOWARD THE NY-STATE THRUWAY AND WESTERN MOHAWK VALLEY.

LAKE EFFECT ACTIVITY WILL DECREASE MONDAY NIGHT AS CYCLONIC FLOW
ALOFT BECOMES MORE ANTICYCLONIC AS SURFACE HIGH BUILDS INTO THE
REGION. THIS RIDGE WILL CREST OVER THE REGION ON TUESDAY AS DEEP
TROUGH OVER THE WESTERN CONUS OPENS UP AND QUICKLY PROGRESSES
EASTWARD ACROSS THE COUNTRY ON TUESDAY. WARM ADVECTION CLOUDS WILL
INCREASE THROUGH THE DAY AND NIGHT WITH ASSOCIATED RAINFALL
HOLDING OFF UNTIL UNTIL TUESDAY NIGHT. MOS GUIDANCE VALUES ARE IN
EXCELLENT AGREEMENT AND A COMPROMISE WAS UTILIZED THIS FORECAST
CYCLE.

&&

.LONG TERM /TUESDAY NIGHT THROUGH SATURDAY/...
THE WEATHER WILL CONTINUE TO BE SOMEWHAT UNSETTLED DURING
THIS PERIOD...WITH THE REGION IN THE VICINITY OF THE 300 HPA
JET BETWEEN LOW PRESSURE TO THE NORTH AND THE SUBTROPICAL
HIGH. A WEAK HIGH OVER THE MID ATLANTIC REGION TUESDAY WILL
SLIDE OFFSHORE AS A LOW MOVES NORTHEAST OUT OF THE PLAINS
STATES ACROSS THE WESTERN GREAT LAKES INTO CANADA AND DRAGS
A FRONT THROUGH THE REGION WEDNESDAY...FOLLOWED BY A WEAK
HIGH BUILDING INTO THE MID ATLANTIC STATES WEDNESDAY NIGHT.
THAT HIGH MOVES OFFSHORE THURSDAY AS THE NEXT SYSTEM MOVES
IN FROM THE WEST THURSDAY NIGHT AND MOVES ACROSS THE REGION
FRIDAY. HIGH PRESSURE BUILDS INTO THE REGION FROM THE WEST
BUT AS THE LOW DEEPENS OVER THE MARITIMES IT WILL SET UP A
CYCLONIC CIRCULATION BRINGING COLD AIR INTO THE REGION OUT
OF CENTRAL CANADA WHERE 850 HPA TEMPS WILL BE MINUS 6 TO
MINUS 10. THE WEST/NORTHWEST TRAJECTORY WILL ALSO LIKELY
RESULT IN LOTS OF CLOUDS FROM THE MOHAWK VALLEY AND
CATSKILLS NORTH AND WEST ALONG WITH SOME SHOWERS DOWNWIND
FROM LAKE ONTARIO. TEMPERATURES START OUT FAIRLY PLEASANT
WITH HIGHS IN THE 50S AND 60S AND LOWS IN THE 40S AND 50S
BUT DROP SOME FRIDAY NIGHT AND SATURDAY WITH HIGHS FRIDAY
AND SATURDAY MOSTLY ONLY IN THE 50S AND LOWS SATURDAY
MORNING IN THE 30S AND 40S. ASIDE FROM WEDNESDAY MORNING
LOWS...WHICH WERE TOO COLD ON THE GMOS...WE USED THE GMOS
TO INITIALIZE THE GRIDS DURING THIS PERIOD BUT MODIFIED
THE POPS TO ADJUST FOR LOCAL EFFECTS OF THE LAKES AND
TERRAIN.

&&

.AVIATION /12Z SUNDAY THROUGH THURSDAY/...
-- Changed Discussion --
FOG AND OR LOW CLOUDS WILL IMPACT ALL TERMINALS TO START OF THE
DAY...WITH MAINLY IFR OR EVEN LIFR EXPECTED THROUGH 14Z. AFTER
14Z...WITH INCREASED MIXING OF THE COLUMN...THE FOG WILL DISSIPATE
FAIRLY QUICKLY AND CEILINGS WILL LIFT BACK AT LEAST TO THE MVFR
RANGE.

A WEAK DISTURBANCE MIGHT TOUCH OFF SCATTERED LIGHT SHOWERS...BUT AT
THIS TIME WE DID NOT EVEN INCLUDE VCSH IN THE TAFS AS THESE SHOWERS
ARE EXPECTED TO BE VERY LIGHT AND NOT IMPACT THE TERMINALS AT
ALL.

THE WIND WILL INCREASE OUT OF THE WEST OR NORTHWEST TO AROUND 8KTS
LATER TODAY.



OUTLOOK...
SUN PM-TUE...VFR...NO SIG WX.
TUE NGT-WED...CHC MVFR RA/SHRA.
WED NGT-THU...VFR...NO SIG WX.-- End Changed Discussion --


&&

.FIRE WEATHER...
-- Changed Discussion --
MINIMUM RELATIVE HUMIDITIES TODAY WILL RANGE BETWEEN 40-60
PERCENT...QUICKLY CLIMB TOWARD 90-100 PERCENT TONIGHT...AND RANGE
BETWEEN 45 AND 75 PERCENT ON MONDAY /THE HIGHER VALUES INTO THE
TERRAIN DOWNWIND OF LAKE ONTARIO AND PORTIONS OF THE GREENS AND
BERKS/.

WINDS WILL GENERALLY REMAIN WESTERLY AT SPEEDS OF LESS THAN 10
MPH TODAY AND TONIGHT...WITH AN INCREASE IN SPEEDS ON MONDAY OF
VALUES BETWEEN 10-20 MPH.-- End Changed Discussion --


&&

.HYDROLOGY...
RIVERS ACROSS THE REGION CONTINUE AT LOW FLOWS AS MOST OF THE
RAIN CONTINUES TO JUST SOAK INTO THE GROUND. THE HEAVIER RAIN
TO THE EAST AFFECTED A FEW SMALLER BASINS BUT FOR THE MOST PART
WAS EAST OF THE HOUSATONIC BASIN. THE NEXT PERIOD OF SIGNIFICANT
RAINFALL LOOKS TO BE TUESDAY NIGHT INTO WEDNESDAY BUT MODELS
SUGGEST IT WILL AMOUNT TO LESS THAN HALF AN INCH IN MOST AREAS
WHICH WILL HAVE LITTLE EFFECT ON STREAMFLOW.

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.

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....

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Area Forecast Discussion
Issued by NWS Albany, NY

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000
FXUS61 KALY 061150
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
749 AM EDT TUE OCT 6 2009

.SYNOPSIS...
A TRANQUIL DAY AHEAD AS HIGH PRESSURE SLIDES ACROSS THE REGION.
HOWEVER...A NOTICEABLE INCREASE IN CLOUD COVER WILL OCCUR THROUGH
THE DAY IN ADVANCE OF OUR NEXT STORM SYSTEM. RAIN ARRIVES THIS
EVENING FOR EASTERN NEW YORK AND OVERNIGHT FOR ADJACENT WESTERN
NEW ENGLAND. A STRONG COLD FRONT SLIDES EAST OF THE AREA ON
WEDNESDAY WITH COOLER AND WINDY WEATHER EXPECTED.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
AS OF 745 AM EDT...STILL SOME RESIDUAL SPRINKLES ARE OCCURRING
ACROSS PORTIONS OF THE CENTRAL/WESTERN MOHAWK VALLEY...WHILE BREAKS
IN THE CLOUDS HAVE DEVELOPED AND EXPANDED WITHIN AND CLOSE TO THE
HUDSON RIVER VALLEY. THERE SHOULD BE A DIMINISHING TREND FOR THESE
SPRINKLES OVER THE NEXT 1-3 HOURS. HOWEVER...CLOUDS MAY BRIEFLY
EXPAND A BIT...OR REDEVELOP FROM KALB NORTH AND NORTHEAST...AS
MIXING DEEPENS. THESE CLOUDS SHOULD THEN DECREASE SOMEWHAT FROM
SOUTHWEST TO NORTHEAST DURING THE AFTERNOON HOURS...ONLY TO BE
INTERRUPTED BY THE ARRIVAL OF HIGH AND MID LEVEL CLOUDS FROM THE
SOUTHWEST ASSOCIATED WITH WARM ADVECTION AHEAD OF NEXT SYSTEM.

PREVIOUS DISCUSSION FOLLOWS...

AS OF 3 AM...LAKE EFFECT SHOWERS CONTINUE DOWNWIND OF LAKE ONTARIO
WITH SHOWERS PROGRESSING INTO THE WESTERN MOHAWK VALLEY THEN
DISSIPATING OVER THE SCHOHARIE VALLEY. THIS DISSIPATING TREND WILL
CONTINUE AS RIDGE AXIS ALOFT AND AT THE SURFACE SUPPRESS CONVECTIVE
GROWTH THROUGH THE DAY. HOWEVER...AS SEEN IN THE IR IMAGERY THIS
MORNING...CI/CS DECK WAS PROGRESSING QUICKLY ACROSS LOWER MICHIGAN
AND ONTARIO. SO WE WILL CALL IT PTSUNNY FOR THE BALANCE OF THE DAY
WITH TEMPERATURE FORECAST A LITTLE BIT OF A CHALLENGE. FORECAST
BUFR PROFILES POINT TOWARD MIXING LAYER HEIGHTS RIGHT AT 850MB
WHICH YIELDS MID-UPPER 60S FOR VALLEY LOCATIONS. HOWEVER...THE
AFOREMENTIONED CLOUD COVER DOES CONTINUE TO FILTER OUT INSOLATION
POTENTIAL WHICH AGREES THE TRENDS SEEN IN THIS MORNINGS LAMP
GUIDANCE. SO WE WILL SHAVE OFF A COUPLE DEGREES FROM MOS GUIDANCE.-- End Changed Discussion --


&&

.SHORT TERM /6 PM THIS EVENING THROUGH WEDNESDAY NIGHT/...
STRONG WARM ADVECTION AND ASSOCIATED ISENTROPIC LIFT INCREASE IN
EARNEST THIS EVENING WITH RAIN DEVELOPING OVER THE NY CWA THIS
EVENING AND ADJACENT WESTERN NEW ENGLAND TOWARD MIDNIGHT. THE LOW
LEVEL JET MAGNITUDE INCREASES TOWARD 50KTS WHERE FAVORABLE UPSLOPE
AREAS MAY RECEIVE A PERIOD OF HEAVIER RAINFALL OVERNIGHT.
FURTHERMORE...MID LEVEL INSTABILITY INCREASE WITH THOSE SHOWALTER
INDICES DROPPING TO AT OR BELOW 0C.

THE SURFACE LOW TRACKS NORTHWEST OF THE CAPITAL REGION ON
WEDNESDAY. ITS ATTENDING STRONG COLD FRONT WILL TRANSVERSE THE
REGION WITHIN A COUPLE HOURS OF SUNRISE WEDNESDAY...THEN COLD
ADVECTION WILL OCCUR THROUGH THE DAY AS STRONG SURFACE PRESSURE
GRADIENT AND WINDS ALOFT WILL COMBINE FOR A BRISK AFTERNOON AND
EVENING. AS THE UPPER LOW AND COLD POOL MOVE OVERHEAD...LAPSE
RATES WILL BE RATHER STEEP AND WE WILL RETAIN THE MENTION OF
THUNDER AS SUGGESTED BY THE PREVIOUS FORECAST. THERE IS STILL IS
THE POTENTIAL FOR WIND ADVISORY CRITERIA TO BE MET FOR THE
SOUTHERN 2/3RDS OF THE CWA AS 900-925MB WIND SPEEDS ARE AROUND
50KTS WHICH IS WHERE OUR EFFECTIVE MIXING LAYER IS FORECAST TO BE.
IT DOES SEEM THE ARRIVAL OF THIS STRONGEST WINDS OCCUR BETWEEN
21Z- 03Z /THE GFS WINDOW IS LITTLE NARROWER/. WE WILL CONTINUE TO
HIGHLIGHT IN THE HWO THIS MORNING.

WINDS WILL SUBSIDE WEDNESDAY NIGHT AS THIS STORM MOVES RATHER
QUICKLY OFF THE NEW ENGLAND SEABOARD AND ANTICYCLONIC FLOW RETURNS
TO THE REGION. CLOUDS AND SOME LINGERING SHOWERS MAY HOLD ON
ACROSS THE HIGHER TERRAIN BUT EVENTUALLY THE INCREASED SUBSIDENCE
WILL SUPPRESS THIS ACTIVITY AS WELL OVERNIGHT. MACHINE NUMBERS ARE
ALL WITHIN 1 DEGREE AND DID A MODEL BLEND WHICH IS QUITE CLOSE TO
OUR CURRENT FORECAST OVERNIGHT LOWS WEDNESDAY NIGHT.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
HIGH PRESSURE MOVES FROM THE OHIO VALLEY TO OFF THE MID ATLANTIC
COAST THURSDAY...WITH THE NORTHERN RIDGE MOVING ACROSS OUR AREA
WHICH SHOULD GIVE US SUNNY SKIES FOR MUCH OF THE DAY ALONG WITH
WESTERLY WINDS AND HIGHS MOSTLY IN THE 60S. THE CIRRUS SHIELD
ASSOCIATED WITH A WARM FRONT WILL BEGIN TO OVERSPREAD THE REGION
DURING THE AFTERNOON. RAIN SPREADS INTO THE REGION LATE THURSDAY
NIGHT WITH THE WARM FRONT AND THEN LIFTS NORTH...FOLLOWED BY THE
PASSAGE OF A COLD FRONT FRIDAY EVENING. A CANADIAN HIGH THEN
MOVES IN FROM THE WEST OVER THE WEEKEND...WITH SKIES CLEARING
ON SATURDAY AND HIGHS RANGING FROM THE 50S IN THE ADIRONDACKS
AND HIGHER ELEVATIONS OF SOUTHERN VERMONT TO THE MID 60S IN
THE HUDSON VALLEY. LOWS SATURDAY NIGHT WILL RANGE FROM THE
UPPER 20S ACROSS THE ADIRONDACKS TO THE LOW 40S IN THE HUDSON
VALLEY SOUTH OF ALBANY. IT WILL BE NOTABLY COOLER SUNDAY WITH
HIGHS FROM NEAR 50 IN THE ADIRONDACKS TO NEAR 60 IN THE LOWER
HUDSON AND HOUSATONIC VALLEYS. A CONTINUED CYCLONIC FLOW AROUND
A DEEP UPPER LOW OVER HUDSON BAY WILL RESULT IN CONTINUED COOL
WEATHER WITH THE POSSIBILITY OF LAKE EFFECT/ENHANCED SHOWERS
NORTH OF THE MOHAWK VALLEY. BOTH THE GFS AND EURO DEVELOP A
COASTAL LOW SUNDAY NIGHT/MONDAY WHICH COULD BRING A SIGNIFICANT
RAIN TO THE REGION ON MONDAY. THE POSITIONS AND TIMING OF THE
MODELS DIFFER...AND THUS WILL SIMPLY GO WITH CHANCE POPS FOR
MONDAY. LOWS SUNDAY NIGHT WILL MOSTLY BE IN THE 30S WHILE
HIGHS MONDAY WILL MOSTLY BE IN THE 50S...ABOUT 5 DEGREES COOLER
THAN NORMAL.

&&

.AVIATION /12Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
WE EXPECT VFR CONDITIONS THROUGH AT LEAST MIDNIGHT TONIGHT...WITH
JUST SOME SCT-BKN VFR LEVEL CLOUDS EXPECTED.

LATER TONIGHT...AS A WARM FRONT APPROACHES...A STEADY LIGHT/MODERATE
RAIN SHOULD OVERSPREAD THE REGION FROM SOUTHWEST TO NORTHEAST AROUND
OR AFTER MIDNIGHT. CONDITIONS SHOULD DETERIORATE DURING THIS
TIME...TRENDING TOWARD MVFR...THEN POSSIBLY IFR AFTER 08Z/WED. THE
PRECIPITATION SHOULD BECOME MORE SHOWERY TOWARD AND AFTER
10Z/WED...AS THE WARM FRONT PASSES THROUGH. HOWEVER...THE COLD FRONT
WILL BE APPROACHING FROM THE WEST...WHICH MAY PRODUCE A NARROW
BAND/LINE OF HEAVIER SHOWERS AND EVEN SOME THUNDERSTORMS TOWARD OR
JUST AFTER 12Z/WED. AT THIS TIME...HAVE NOT INCLUDED MENTION IN
TAFS...BUT SUBSEQUENT ISSUANCES MAY NEED AT LEAST CB APPENDAGE DUE
TO MORE CONVECTIVE NATURE OF PRECIPITATION ASSOCIATED WITH
APPROACHING COLD FRONT.

WINDS WILL BE MAINLY FROM THE WEST TO NORTHWEST THROUGH MIDDAY
TODAY...AT 5-10 KT. THE WINDS WILL BRIEFLY BECOME LIGHT/VARIABLE
LATER THIS AFTERNOON...BEFORE SHIFTING TO THE SOUTH AND SOUTHEAST
TOWARD AND AFTER SUNSET. TONIGHT...WINDS WILL BECOME MAINLY
SOUTHEAST...AT 5-10 KT...INCREASING FROM THE SOUTH AFTER THE WARM
FRONT PASSES...AT 10-20 KT AT KALB AND KPOU...AND AROUND 10 KT
ELSEWHERE. SOME GUSTS MAY EXCEED 20 KT AFTER 10Z/WED AT KALB...WHERE
FUNNELING/ENHANCEMENT OF WINDS THROUGH THE HUDSON RIVER VALLEY IS
POSSIBLE.

LOW LEVEL WIND SHEAR IS EXPECTED AFTER 09Z/WED...ESP AT KGFL AND
KPOU...WHERE SFC WINDS REMAIN RELATIVELY LIGHT...10 KT OR LESS FROM
THE SOUTHEAST TO SOUTH...WHILE WINDS AT AND ABOVE 2000 FT AGL
INCREASE FROM THE SOUTH AT 30-40 KT.

OUTLOOK...
TUE NGT-WED...MVFR IN RA/SHRA.
WED NGT-FRI...VFR...NO SIG WX.
FRI NT/SAT...CHC MVFR/SCATTERED SHRA.-- End Changed Discussion --


&&

.FIRE WEATHER...
-- Changed Discussion --
A DRY DAY WILL QUICKLY BE REPLACED BY A SOAKING RAINFALL TONIGHT.
WINDY ALONG WITH SHOWER ACTIVITY WILL BE IN PLACE THROUGH
WEDNESDAY.

RELATIVE HUMIDITY VALUES WILL DROP TO AROUND 40 TO 60 PERCENT
THIS AFTERNOON. VALUES WILL INCREASE TO BETWEEN 90 AND 100
PERCENT TONIGHT...THEN ONLY DROP TO AROUND 65 TO 85 PERCENT ON
WEDNESDAY.

WEST WINDS AROUND 5 TO 10 MPH TODAY. WINDS WILL BECOME SOUTHEAST 5
TO 10 MPH TONIGHT WITH SOME HIGHER GUSTS ACROSS THE HIGHER
TERRAIN...THEN SHIFTING TO THE WEST ON WEDNESDAY AND INCREASING TO
15 TO 25 MPH WITH GUSTS OF 35 TO 45 MPH POSSIBLE.-- End Changed Discussion --


&&

.HYDROLOGY...
-- Changed Discussion --
NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH THE NEXT FIVE DAYS...WITH
RIVERS ACROSS THE REGION CONTINUING AT GENERALLY LOW FLOWS. THE NEXT
PERIOD OF WIDESPREAD RAINFALL WILL BE TONIGHT INTO
WEDNESDAY...AS A LOW PRESSURE SYSTEM AND COLD FRONT PASS THROUGH.
MODELS SUGGEST QPF AMOUNTS WILL RANGE FROM AROUND ONE INCH ACROSS
THE HIGHER TERRAIN WITH ONE THIRD TO TWO THIRDS OF AN INCH
ELSEWHERE. THIS AMOUNT OF RAINFALL WILL CAUSE SOME VERY MODEST
INCREASES IN STREAMFLOW...ESPECIALLY IN THE ADIRONDACKS AND
SOUTHERN VERMONT DUE TO MORE RAIN AND WETTER GROUND CONDITIONS.
FARTHER SOUTH...ONLY VERY SLIGHT INCREASES IN FLOW ARE EXPECTED.

DRY CONDITIONS EXPECTED TO RETURN FOR THURSDAY...WITH MORE RAIN ON
FRIDAY...AS ANOTHER FRONTAL SYSTEM APPROACHES FROM THE GREAT LAKES.

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.-- End Changed Discussion --


&&

.ALY WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
MA...NONE.
VT...NONE.

&&

$$
SYNOPSIS...BGM
NEAR TERM...KL/BGM
SHORT TERM...BGM
LONG TERM...RCK
AVIATION...KL/RCK
FIRE WEATHER...BGM
HYDROLOGY...RCK

[ROLLTIDE]

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[ROLLTIDE]

...

[ROLLTIDE]

Area Forecast Discussion
Issued by NWS Albany, NY

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000
FXUS61 KALY 271442
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1042 AM EDT TUE OCT 27 2009

.SYNOPSIS...
-- Changed Discussion --
AS A RIDGE OF HIGH PRESSURE GRADUALLY SLIDES OFF THE NEW ENGLAND
COAST THIS AFTERNOON. A SERIES OF LOW PRESSURE SYSTEMS WILL PASS
SOUTH OF THE REGION THIS AFTERNOON INTO WEDNESDAY...BRINGING SOME
RAIN TO AREAS MAINLY SOUTH AND EAST OF ALBANY THIS AFTERNOON...AND
TO THE ENTIRE REGION ON WEDNESDAY. HIGH PRESSURE AND FAIR WEATHER
WILL RETURN FOR THURSDAY.-- End Changed Discussion --


&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
ONE WAVE OF LOW PRESSURE AND WEAK UPPER ENERGY IS TRACKING SOUTH
OF THE REGION...WITH THE NORTHERN PERIPHERY OF THE PRECIPITATION
ABOUT TO POU AND NW CT...TRACKING EAST AND NORTHEAST. SUNNY IN FAR
NORTHERN AND NORTHWESTERN AREAS...BUT TRENDS SUGGEST THIS HOLE
WILL FILL IN THROUGH THE DAY. WITH THE SUNSHINE IN NORTHWESTERN
AREAS...HIGHS WILL BE A DEGREE OR TWO WARMER THAN CURRENT
FORECAST...INTO THE MID TO UPPER 50S. WITH THE CLOUDS OVER MOST
OF THE REST OF THE AREA...AND THE PRECIPITATION IN SOUTHERN
AREAS...TEMPERATURES WILL BE CAPPED IN THE LOWER 50S. SO...SOME
MINOR ADJUSTMENTS TO CLOUD COVER AND TEMPERATURES.

PREV AFD BELOW...

CLOUDS WILL GRADUALLY INCREASE TODAY AS THE REGION GETS SQUEEZED
BETWEEN A LOW PRESSURE SYSTEM APPROACHING FROM THE SOUTH...AND ONE
APPROACHING FROM THE WEST. THE SOUTHERN SYSTEM IS NOW FORECAST TO BE
MORE ACTIVE THAN PREVIOUS MODEL RUNS HAD INDICATED...AND RAIN IS
EXPECTED TO AFFECT PARTS OF THE REGION TO THE SOUTH AND EAST OF
ALBANY. HAVE FORECAST SLIGHT OR LOW CHANCE POPS FROM THE SCHOHARIE
VALLEY TO THE CAPITAL DISTRICT AND SOUTHERN VERMONT FOR TODAY...
RANGING UP TO LIKELY POPS ACROSS SOUTHEAST ULSTER COUNTY AND MOST OF
DUTCHESS AND LITCHFIELD COUNTIES.

WITH CLOUDS MORE WIDESPREAD AND SOME PCPN LIKELY ACROSS THE
SOUTHEAST PART OF THE FORECAST AREA...HAVE LOWERED MAX TEMPS FOR
TODAY BY A FEW DEGREES...WITH HIGHS FORECAST TO BE IN THE UPPER 40S
TO LOWER 50S.-- End Changed Discussion --


&&

.SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/...
THE FIRST SYSTEM WILL MOVE OUT QUICKLY THIS EVENING...BUT WILL
BE QUICKLY FOLLOWED BY AN UPPER LEVEL TROF MOVING NORTHEAST FROM THE
OHIO VALLEY LATER TONIGHT...THEN MOVING THROUGH THE REGION ON
WEDNESDAY. ANOTHER SURFACE LOW WILL FORM NEAR THE MID ATLANTIC COAST
EARLY WEDNESDAY IN RESPONSE TO THIS UPPER LOW...THEN MOVE OUT TO
SEA.

THE WILL RESULT IN ONLY A BRIEF LOWERING OF POPS ACROSS THE
SOUTHEAST PART OF THE FORECAST AREA THIS EVENING...THEN POPS ARE
FORECAST TO RISE AGAIN LATER TONIGHT...WITH LIKELY TO CATEGORICAL
POPS FOR MOST OF WEDNESDAY FOR THE ENTIRE REGION.

AS THE LOW MOVES AWAY WEDNESDAY NIGHT...WILL MAINTAIN A CHANCE OF
RAIN DURING THE EVENING...WITH NO PCPN FORECAST AFTER MIDNIGHT.

HIGH PRESSURE WILL BUILD IN FOR THURSDAY WITH DRY WEATHER FORECAST.

LOWS TONIGHT WILL BE IN THE MID 30S TO MID 40S. HIGHS WEDNESDAY WILL
BE 45 TO AROUND 50 AS CLOUDS AND PCPN KEEP MAX TEMPS DOWN. LOWS
WEDNESDAY NIGHT WILL BE IN THE LOW 30S TO AROUND 40...AND THE HIGHS
THURSDAY MAINLY IN THE 50S.

&&

.LONG TERM /THURSDAY THROUGH MONDAY/...
AN UPPER LEVEL RIDGE WILL REMAIN OVER THE REGION THUR NIGHT...WITH
THE RIDGE AXIS FORECAST TO BE OVERHEAD AROUND 12Z FRI. THE SURFACE
HIGH WILL START TO SHIFT EASTWARD A BIT EARLIER...SO A RETURN
SOUTHERLY FLOW WILL BEGIN TO DEVELOP. BOUNDARY LAYER WILL LIKELY
DECOUPLE THOUGH...SO WHILE MIN TEMPS NOT EXPECTED TO BE COLD THEY
WILL ONLY RUN ABOUT 3-5 DEGREES ABOVE AVG. FRI WILL BE A WARM DAY
ACROSS THE REGION...WITH A STRENGTHENING SOUTHERLY FLOW AT THE
SURFACE AND SOUTHWEST FLOW ALOFT. CLOUDS MAY INCREASE LATE IN THE
DAY BUT THERE SHOULD BE ENOUGH SUN COMBINED WITH H85 TEMPS AROUND
+10C TO MOST VALLEY LOCATIONS TO REACH THE LOWER 60S.

THE UPPER LEVEL RIDGE AXIS SHIFTS EAST OF THE AREA FRI NIGHT...AS A
COLD FRONT FRONT STARTS TO MIGRATE EASTWARD ACROSS THE GREAT LAKES.
SOME WEAK ISENTROPIC LIFT PRESENT WELL OUT AHEAD OF THE FRONT SO
WILL MENTION LOW CHANCE POPS FRI NIGHT. WITH INCREASING CLOUDS AND
BOUNDARY LAYER WINDS STRENGTHENING...MIN TEMPS WILL BE MILD IN THE
40S.

AFOREMENTIONED COLD FRONT WILL PUSH THROUGH THE REGION ON
SAT...HOWEVER TIMING IS IN QUESTION. MOST OF THE DECENT DYNAMICS
TIED TO THE NORTHERN STREAM UPPER LOW WILL BE DISPLACED WELL NORTH
INTO CANADA...HOWEVER A SOUTHERN STREAM UPPER LOW THAT IS FORECAST
TO MOVE ACROSS THE DESERT SOUTHWEST AND SOUTHERN PLAINS THUR INTO
FRI MAY GET CAUGHT UP IN THE FLOW ALOFT AND BECOME A PROGRESSIVE
OPEN WAVE. THIS WAVE MAY REACH THE NORTHEAST DURING FROPA ON SAT.
THIS CAUSES SOME COMPLICATIONS IN TIMING AND ALSO QPF. THE 00Z ECMWF
IS SHOWING AROUND AN INCH NOW...WHILE THE 00Z GFS IS CONSIDERABLY
LIGHTER. DUE TO UNCERTAINTY WILL MENTION 50 POPS FOR NOW THROUGH 00Z
SUNDAY. DEPENDING ON FROPA TIMING...TEMPS COULD REACH WELL INTO THE
60S ESPECIALLY FROM THE HUDSON VALLEY EASTWARD.

ANOTHER CONCERN MAY BE FOR POSSIBLE STRONG WINDS ON SAT.
HOWEVER...SOUTHERLY COMPONENT NOT FAVORABLE FOR MIXING DESPITE 50-60
KT H85 WIND SPEEDS. LIKELY AREA FOR ANY ISSUES WILL BE ACROSS THE
HIGHER TERRAIN.

BEHIND THE FRONT WINDS WILL SHIFT TO THE WEST SAT NIGHT AND
EVENTUALLY W-NW ON SUNDAY. ECMWF MUCH SLOWER WITH FROPA AND IS
SHOWING ADDITIONAL QPF SAT NIGHT...WHILE THE GFS IS MORE
PROGRESSIVE. THE GGEM IS MORE ALIGNED WITH THE GFS. WILL MENTION
CHANCE POPS...BUT WILL GO WITH 40 PERCENT AT THIS TIME.

COOLER AND BREEZY CONDITIONS FOR SUNDAY...WITH SOME POSSIBLE LAKE
ENHANCED/UPSLOPE RAIN/SNOW SHOWERS ACROSS THE HIGHER TERRAIN. BEST
CHANCE FOR ANY SNOW MIXING IN WILL BE DURING THE OVERNIGHT AND EARLY
MORNING HOURS. WINDS SLACKEN A BIT MORE FOR MON...AS WEAK HIGH
PRESSURE MOVES IN.

&&

.AVIATION /15Z TUESDAY THROUGH SATURDAY/...
FIRST CONCERN THIS MORNING IS FOR LLWS FROM KALB TO KGFL...AS WINDS
AROUND 1500-2000 FT AGL HAVE INCREASED TO 30 KT WITH SFC WINDS NEAR
CALM. WILL MENTION LLWS AT KGFL/KALB THROUGH AROUND 14Z-15Z BEFORE
WINDS ALOFT WEAKEN.

PRECIP AND LOW STRATUS ASSOC WITH A COMPACT COASTAL LOW ALONG THE
MID ATLANTIC COAST QUICKLY MOVING NORTHWARD...WITH MVFR CIGS ALREADY
INVADING KPOU. FORECAST MODELS SEEM TO BE A BIT SLOW WITH
PROGRESSION OF CLOUDS/RAIN...SO WILL KEEP KPOU IN MVFR RANGE THROUGH
THE DAY WITH -RA DEVELOPING BETWEEN 13Z-15Z. CONDITIONS WILL BE MORE
TRANQUIL AT KALB-KGFL...WHERE RAINFALL SHOULD REMAIN SOUTH OF THESE
TERMINALS. HOWEVER...SATELLITE AND TRENDS FROM SFC OBS INDICATE
STRATUS CLOUDS IN MVFR RANGE WILL MAKE IT UP TO KALB AROUND 14Z-15Z.
PRECIP SHIELD WILL GET CLOSE BUT SHOULD REMAIN JUST SOUTH OF KALB.
CONDITIONS SHOULD REMAIN VFR AT KGFL...BUT WITH OVC SKIES.

-RA WILL LIKELY TAPER TO -DZ AT KPOU BY AROUND 22Z...WITH THE NEXT
BATCH OF STEADY RAIN MOVING IN AROUND 06Z/WED ASSOC WITH A RAPIDLY
APPROACHING TROF OF LOW PRESSURE. CONDITIONS ARE EXPECTED TO
DETERIORATE TO IFR/LIFR AT KPOU AROUND 06Z AS WELL. WILL FORECAST
IFR CIGS AT KALB STARTING AROUND 08Z/WED...AS -RA DEVELOPS. WILL
MENTION MVFR CIGS AT KGFL FROM 08Z-12Z/WED WITH VCSH AS -RA
ENCROACHES.

WINDS WILL BE GENERALLY E-SE AROUND 3-6 KT AT KGFL/KALB BUT NE AT
KPOU TODAY. WINDS WILL SHIFT TO THE NE AT ALL THREE TERMINALS
TONIGHT BUT SPEEDS ONLY AROUND 3 KT.

OUTLOOK...
WED...IFR/MVFR...OCNL -RA.
WED NGT...VFR/MVFR...CHC -SHRA.
THU/FRI...VFR...NO SIG WX.
SAT...VFR/MVFR...CHC -SHRA.

&&

.FIRE WEATHER...
AS A RIDGE OF HIGH PRESSURE GRADUALLY SLIDES OFF THE NEW ENGLAND
COAST TODAY...A SERIES OF LOW PRESSURE SYSTEMS WILL PASS SOUTH OF
THE REGION LATE TODAY INTO WEDNESDAY...BRINGING SOME RAIN TO AREAS
MAINLY SOUTH AND EAST OF ALBANY TODAY...AND TO THE ENTIRE REGION ON
WEDNESDAY. HIGH PRESSURE AND FAIR WEATHER WILL RETURN FOR THURSDAY.

THE RH WILL ONLY LOWER TO BETWEEN 60 AND 80 PERCENT TODAY AS
MOISTURE INCREASES AHEAD OF APPROACHING LOW PRESSURE SYSTEMS.
THE RH WILL RISE TO NEAR 100 PERCENT TONIGHT AND REMAIN ABOVE
80 PERCENT ON WEDNESDAY AS RAIN MOVES INTO THE ENTIRE REGION.

SURFACE WINDS WILL BE SOUTHEAST 5 TO 15 MPH TODAY...LIGHT AND
VARIABLE TONIGHT...AND EAST TO NORTHEAST 5 TO 15 MPH ON WEDNESDAY.

&&

.HYDROLOGY...
NO HYDRO PROBLEMS ARE ANTICIPATED THROUGH THE REST OF THE WORK WEEK.
RIVER LEVELS WILL CONTINUE TO RECEDE THROUGH TODAY. HOWEVER...FLOWS
WILL CONTINUE TO BE ABOVE NORMAL FOR LATE OCT THROUGH MUCH OF THE
WEEK.

THE NEXT CHANCE FOR SOME RAINFALL WILL BE THIS AFTERNOON INTO THIS
EVENING ACROSS SOUTHERN AREAS...AS A WEAK COASTAL LOW PASSES NEARBY.
QPF AMOUNTS WILL LIKELY BE LESS THAN ONE QUARTER INCH AND CONFINED
TO A LIMITED AREA FROM THE MID HUDSON VALLEY EASTWARD TO THE
HOUSATONIC BASIN.

MORE RAINFALL WILL OCCUR ON WEDNESDAY WITH THE APPROACH OF A
WEAKENING TROF OF LOW PRESSURE...WITH THE ENTIRE AREA EXPECTED TO
RECEIVE RAIN. QPF AMOUNTS SHOULD RANGE FROM ONE TENTH TO ONE
QUARTER INCH FROM ALBANY NORTHWARD...WITH ONE QUARTER TO AS MUCH AS
THREE QUARTERS OF AN INCH SOUTH OF ALBANY. THESE AMOUNTS WILL CAUSE
SOME MINOR WITHIN BANK RISES...ESPECIALLY SOUTH OF ALBANY.

MORE RAIN EXPECTED ON SATURDAY WITH THE APPROACH OF A COLD FRONT.
QPF AMOUNTS STILL IN QUESTION AT THIS TIME THOUGH. MOST MODELS
SHOWING A PROGRESSIVE SOLUTION THAT WOULD RESULT IN MAINLY LIGHT
QPF...HOWEVER THERE IS SOME INDICATION THE FRONT MAY BE SLOWER TO
PASS THROUGH RESULTING IN GREATER QPF. CHECK BACK FOR FURTHER
UPDATES AS THIS SYSTEM EVOLVES.

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.

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