Area Forecast Discussion
Issued by NWS Albany, NY

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FXUS61 KALY 261348
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
948 AM EDT SUN APR 26 2015

.SYNOPSIS...
THE UPPER LEVEL STORM IN THE GULF OF MAINE WILL KEEP OUR
WEATHER UNSETTLED AND UNSEASONABLY COOL THROUGH EARLY THIS WEEK.  A
RETURN TO MORE SPRING LIKE WEATHER IS EXPECTED FOR THE MID WEEK
PERIOD.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
AS OF 930 AM EDT...STLT PICS SHOWED A LARGE AREA OF CLOUDINESS
ACROSS MUCH OF EASTERN NY AND WESTERN NEW ENGALND...AND ANOTHER
AREA OVER WESTERN NY. IN BETWEEN...MAINLY CLEAR SKIES. IT WAS ALSO
MAINLY CLEAR OVER THE SOUTHERN CATSKILLS AND LOWER HUDSON VALLEY.
THESE CLOUDS WERE MOVING SOUTHWARD AS THEY ROTATE AROUND THE UPPER
LOW OVER THE GULF OF MAINE. CLOUDS WILL TEND TO INCREASE FURTHER
DURING THE DAY AS HEATING CASUES CUMULUS CLOUDS TO FORM EVEN THOSE
AREAS THAT ARE CURRENTLY MAINLY CLEAR. PREVIOUS FORECAST GENERALLY
IN GOOD SHAPE CONCERNING CLIOUD COVER WITH ONLY MINOR ADJUSTMENTS
MADE.

PREVIOUS DISCUSSION...
EXPECTATIONS ARE FOR THIS CLOUD DECK TO REMAIN SCT-BKN AND BECOME
MORE BKN THROUGH THE DAY AS SHORT WAVE JUST TO THE NORTH OF LAKE
ONTARIO ALONG WITH DAYTIME HEATING ALL COMBINE FOR CLOUD COVERAGE
AND THE CHANCE FOR SOME SHOWERS. LATEST HRRR/HRRRX SUGGEST MORE
SHOWER DEVELOPMENT LATER THIS AFTERNOON SO WE HAVE EXPANDED THE
POPS A BIT. PREVIOUS AFD DETAILS BELOW...

PER THE H2O VAPOR ANALYSIS...A QUASI OMEGA BLOCK ACROSS NOAM WITH
THE SUBTROPICAL JET STREAMING ACROSS MEXICO...THROUGH WESTERN
NOAM AND LARGE UPPER LOW OVER THE NORTH ATLANTIC AS RIDGE REMAINS
IN PLACE ACROSS THE CENTRAL AND NORTHERN PLAINS. THIS PATTERN WILL
KEEP OUR WEATHER ON A COOL AND INCREASINGLY CLOUDY/DAMP SIDE IN
THE NEAR TERM /AND SHORT TERM TOO/.

IR SATELLITE ENHANCED IMAGERY REVEALS A SLOWLY EXPANDING AREA OF
STRATUS ALONG THE I90 CORRIDOR ADVECTING SOUTHWARD THIS SUNDAY
MORNING. WHILE SOME BREAKS IN THE OVERCAST ARE SEEN ACROSS THE ST
LAWRENCE VALLEY...FURTHER UPSTREAM ARE ADDITIONAL CLOUDS WITH THE
WARM ADVECTION PROCESSES UNDERWAY AROUND THE LARGE PERIPHERY OF
THE UPPER LOW ACROSS THE NORTH ATLANTIC. SO THE BALANCE OF THE DAY
WILL FEATURE AN INCREASE IN CLOUD COVERAGE. AS FOR PRECIP
CHANCES...H850-700 LAPSE RATES AND MOISTURE INCREASE ARE EXPECTED
TO DEVELOP SHOWERS ACROSS THE HIGHER TERRAIN /MAINLY IMPACTING
LOCATIONS NORTH OF I90/ THIS AFTERNOON. PREVIOUS EXCELLENT
FORECAST HAD A GREAT HANDLE ON THIS SO LITTLE CHANGES NEEDED AT
THIS TIME. MOS TEMPERATURES FOR TODAY ARE FAIRLY CLOSE TO THE
PREVIOUS FORECAST SO MINOR TWEAKS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
THE LARGE UPPER LOW OVER THE NORTH ATLANTIC IS EXPECTED TO
RETROGRADE A BIT AND REFORM/STRENGTHEN IN THE VICINITY OF THE GULF
OF MAINE. UPPER TROUGH AXIS/SHORT WAVE ALONG WITH WARM ADVECTION
PROCESSES WILL FURTHER INCREASE THE MOISTURE AND THE PROBABILITIES FOR
SHOWERS FROM NORTH TO SOUTH TONIGHT. THERMAL PROFILES ACROSS THE
TERRAIN MAY YIELD SOME WINTRY MIXTURE YET NOT EXPECTING ANY
ACCUMULATIONS. POPS WILL BE GRADUATED FROM SOUTH TO NORTH WITH THE
MID HUDSON VALLEY AND NW CT IN THE SLIGHT CHANCE WITH CHC-SCT POPS
ALONG AND NORTH OF I90.

A RATHER DAMP...CLOUDY AND UNSEASONABLY COOL DAY SETTING UP FOR
MONDAY ACROSS THE ENTIRE REGION. WHILE THE TERRAIN WILL BE
FAVORABLE FOR HIGHER POPS WITH REGARDING TO SHOWERS/DRIZZLE/LIGHT
RAIN...VALLEY LOCATIONS WILL BE MORE SHOWERY. FORECAST SOUNDINGS
SUGGEST A SHALLOW YET PROMINENT INVERTED-V SOUNDINGS SO A LITTLE
BREEZE WITH THESE SHOWERS IS EXPECTED. HIGHS FOR THE REGION WILL
AVERAGE IN THE UPPER 40S TO MIDDLE 50S.

THE SHORT WAVE AND UPPER TROUGH AXIS SLIDES QUICKLY SOUTH AND EAST
OF THE REGION WITH PRECIP LIKELY DIMINISHING IN COVERAGE THROUGH
MONDAY EVENING. HOWEVER...WE REMAIN WELL EMBEDDED IN THE CYCLONIC
FLOW SO THE CLOUDS WILL LINGER ACROSS THE TERRAIN WITH SOME BREAKS
EXPECTED INTO THE VALLEY LOCATIONS. TEMPERATURES WILL REMAIN
RATHER COOL WITH LOWER 40S FOR VALLEY LOCATIONS AND MID-UPR 30S
FOR THE TERRAIN.

TUESDAY INTO TUESDAY NIGHT...THE LARGE UPPER LOW BEGINS TO SLOWLY
MIGRATE FURTHER EAST AS THE UPSTREAM RIDGE ATTEMPTS TO SLIDE IN
FROM THE WEST. WHILE THIS WILL IMPROVE OUR WEATHER OVERALL...NCEP
MODEL SUITE STILL SUGGESTS AMPLE LOW LEVEL MOISTURE REMAINS. THIS
MAY DELAY OUR SKY COVER IMPROVEMENTS AS WE WILL KEEP VALUES INTO
THE PT-MOCLDY RANGE AT THIS TIME. MOS NUMBERS MIGHT BE TOO
OPTIMISTIC AS WE WILL BE A LITTLE MORE CONSERVATIVE PER PARCEL
DECENT IN THE FORECAST BUFR PROFILES.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
WITH THE SLOW MOVING UPPER LEVEL LOW FINALLY MOVED AWAY FROM THE
REGION...WEAK RIDGING AT 500 HPA WILL BUILD INTO THE AREA FOR WED
INTO WED NIGHT. THIS WILL ALLOW DRY WEATHER WITH A PARTLY CLOUDY SKY
AND TEMPS NEAR NORMAL LEVELS...MAINLY 60S FOR DURING THE DAY
WEDNESDAY AND MID 30S TO MID 40S FOR WED NIGHT.

THERE IS STILL PLENTY OF MODEL DISAGREEMENT FOR THE REMAINDER OF THE
EXTENDED PERIOD...AND THE FORECAST IS RATHER LOW CONFIDENCE AT THIS
TIME.  A STORM SYSTEM WILL BE ORGANIZING OFF THE SOUTHEAST COAST AND
WILL BE HEADED NORTHEAST FOR THE LATE WEEK PERIOD. ALTHOUGH MOST
MODEL GUIDANCE SHOWS THIS SYSTEM REMAINING FAR ENOUGH SOUTH AND EAST
OF THE REGION...IT REMAINS UNCERTAIN HOW MUCH OF AN INFLUENCE WILL A
NORTHERN STREAM SHORTWAVE HAVE ON THIS SYSTEM. SOME MODELS SUGGEST A
SHORTWAVE DIVES OUT OF CANADA TOWARDS THE MID ATLANTIC AND BECOMES
ABSORBED BY THIS COASTAL SYSTEM...WHILE OTHERS KEEP IT SEPARATE AND
SLOWER...BRINGING IT EVENTUALLY TOWARDS THE NORTHEAST FOR LATE IN
THE WEEK OR THE WEEKEND. A FEW 00Z GEFS MEMBERS DO SHOW THE COASTAL
SFC LOW BRINGING A WIDESPREAD PRECIP TO THE REGION...BUT FOR THE
MOST PART SHOW THIS WILL NOT OCCUR. HOWEVER...WILL GO WITH SLIGHT TO
LOW CHC POPS FOR THURSDAY THROUGH SATURDAY IN CASE THE DIVING
SHORTWAVE TROUGH MAKES A RUN AT OUR REGION DURING THIS TIME PERIOD
WITH SOME LIGHT RAIN SHOWERS.

FOR NOW...WILL TAKE A MIDDLE OF THE ROAD APPROACH AND GO WITH TEMPS
NEAR NORMAL...WITH 60S FOR DURING THE DAY AND MID 30S TO MID 40S AT
NIGHT. HOWEVER...TEMPS COULD BE LOWER AT TIMES DUE TO MORE
CLOUDS/PRECIP...DEPENDING ON THE EXACT TRACK AND TIMING OF THE
SHORTWAVE TROUGH.

&&

.AVIATION /14Z SUNDAY THROUGH THURSDAY/...
A CUTOFF UPPER LEVEL LOW CONTINUES TO BE SITUATED JUST EAST OF NEW
ENGLAND. THIS UPPER LEVEL LOW WILL START SHIFTING BACK TOWARDS THE
AREA...AND MOISTURE WILL CONTINUE TO ROTATE AROUND THIS FEATURE FROM
THE NORTH.  IN ADDITION...THE COOL TEMPS ALOFT WILL HELP PROMOTE THE
FORMATION OF STRATOCU CLOUDS AS WELL.  ALTHOUGH SKIES ARE CURRENTLY
CLEAR NEAR KPOU...THE NORTHERN SITES ARE ALREADY OVC. ALL SITES LOOK
TO SEE BKN-OVC CIGS OF 4-6 KFT THROUGH THE DAY TODAY...BUT FLYING
CONDITIONS SHOULD BE VFR. W-NW WINDS WILL INCREASE TO ABOUT 5-10 KTS.

WITH THE UPPER LEVEL LOW SHIFTING CLOSER TO THE REGION...A RAIN
SHOWER OR TWO MAY DEVELOP BY LATE THIS EVENING INTO TONIGHT...MAINLY
FOR THE NORTHERN TERMINALS...BUT COVERAGE LOOKS TO TOO SMALL TO
ADDRESS WITH MORE THAN JUST A VCSH IN THE TAFS AT THIS TIME. WINDS
LOOK TO DIMINISH TO 5 KTS OR LESS FOR TONIGHT WITH CONTINUED BKN-OVC
CIGS IN PLACE.

OUTLOOK...

MONDAY NIGHT: MODERATE OPERATIONAL IMPACT. CHANCE OF SHRA.
TUESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
TUESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY: NO OPERATIONAL IMPACT. NO SIG WX.
WEDNESDAY NIGHT: NO OPERATIONAL IMPACT. NO SIG WX.
THURSDAY: LOW OPERATIONAL IMPACT. SLIGHT CHANCE OF SHRA.

&&

.FIRE WEATHER...
THERE WILL BE A FURTHER INCREASE IN CLOUD COVERAGE TODAY...ALONG
WITH CHANCE FOR SHOWERS FROM NORTH TO SOUTH LATER TODAY THROUGH
MONDAY. THIS WILL KEEP RELATIVE HUMIDITIES ELEVATED WITH MINIMUM
VALUES ON SUNDAY RANGING FROM 35 TO 45 PERCENT...THEN 40 TO 60
PERCENT ON MONDAY.

&&

.HYDROLOGY...
THE FORECAST WILL BE DOMINATED BY A PERSISTENT UPPER LEVEL LOW
WHICH WILL RESULT IN COOL TEMPERATURES...BREEZY CONDITIONS AND
CHANCES FOR MAINLY LIGHT PRECIPITATION THROUGH EARLY THIS WEEK.
ANY OF THIS PRECIPITATION WILL HAVE LITTLE IF ANY IMPACT ON OUR
RIVERS AND STREAMS IN OUR HYDROLOGICAL SERVICE AREA /HSA/.

RIVERS AND STREAMS WILL CONTINUE TO SLOWLY RECEDE WITH THE COOLER
TEMPS AND LIGHT SCATTERED PRECIPITATION FORECASTED.

FOR DETAILS ON SPECIFIC AREA RIVER AND LAKES...INCLUDING OBSERVED
AND FORECAST RIVER STAGES AND LAKE ELEVATIONS...PLEASE VISIT THE
ADVANCED HYDROLOGIC PREDICTION SERVICE /AHPS/ GRAPHS ON OUR WEB-
SITE.

&&

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

&&

$$
SYNOPSIS...GJM/BGM
NEAR TERM...BGM
SHORT TERM...GJM/BGM
LONG TERM...FRUGIS
AVIATION...FRUGIS
FIRE WEATHER...GJM/BGM
HYDROLOGY...GJM/BGM



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