-- Discussion containing changed information from previous version are highlighted. --
000
FXUS61 KALY 221447
AFDALY

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1047 AM EDT WED MAY 22 2013

.SYNOPSIS...
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LOW PRESSURE WILL MOVE FROM THE GREAT LAKES REGION TODAY
INTO THE SAINT LAWRENCE VALLEY TOMORROW. WARM AND HUMID CONDITIONS
WILL PERSIST INTO THURSDAY WITH SHOWERS AND THUNDERSTORMS. A STRONG
COLD FRONT WILL MOVE SLOWLY THROUGH NEW YORK AND NEW ENGLAND INTO
THURSDAY NIGHT. LOW PRESSURE WILL FORM ALONG THIS FRONT ON THE COAST
FRIDAY...AS MUCH COLDER AIR POURS INTO THE REGION...AS THE WEATHER
MAY STAY UNSETTLED INTO THE FIRST HALF OF THE MEMORIAL DAY WEEKEND.
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&&

.NEAR TERM /THROUGH TONIGHT/...
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AS OF 1045 AM EDT... A STATIONARY FRONT REMAINS OVER ERN NY AND WRN
NEW ENGLAND...AS IT APPEARS IT WILL BEGIN TO LIFT TO THE N/NE INTO
THE EARLY PM...AS A SHORT-WAVE WITH SOME SCT SHOWERS AND ISOLD
THUNDERSTORMS IS APPROACHING FROM WRN-CNTRL NY. THE POPS ARE
GRADUALLY INCREASED IN THE LATE MORNING INTO THE EARLY PM.

STRATUS IS HANGING TOUGH THIS MORNING...AND SHOULD GRADUALLY ERODE
FROM SW TO NE. THE IS A BETTER AREA OF CLEARING OVER THE OH
VALLEY. THERE IS YET...ANOTHER SHORT-WAVE MOVING TOWARD WRN PA.
THIS DISTURBANCE MAY INCREASE THE POTENTIAL FOR SEVERE WX IN THE
LATE PM/EARLY EVENING...ESPECIALLY OVER WRN NY

WE HAVE BACK OFF THE SVR WX WORDING UNTIL AFTER 3 PM IN THE HOURLY
GRIDS. THE SVR POTENTIAL WILL HINGE ON MORE SHEAR...AND LESSER
AMOUNTS OF INSTABILITY. THE LATEST EXPERIMENTAL HRRR FROM THE SPC
MESOANALYSIS PAGE SHOWS 40-50 KTS OF BULK SHEAR IN THE 0-6 KM
LAYER FROM THE CAPITAL REGION NORTH...AND AND 30-40 KTS TO THE
SOUTHEAST. INSTABILITY VALUES OFF THE 12Z NAM ARE GENERALLY
1000-1500 J/KG WITH SLIGHTLY HIGHER POCKETS OF SBCAPE. MID LEVEL
LAPSE RATES ARE IN THE 6-6.5 C/KM RANGE.

A NEW RUNNING OF THE LOCAL MAGLENTA SEVERE WEATHER INDEX SHOWS A
MINOR SEVERE EVENT WITH THE FOLLOWING VALUES PLUGGED IN:

CAPE=1000 K/KG
MAX SOUNDING WINDS=50 KTS
EHI=1.0
STORM SPEED= 35 KTS
0-3 KM SRH = 100 (M/S)^2

IF THE CAPE IS INCREASED TO 1500 J/KG...WE SHOW A MAJOR EVENT.

THE CONVECTIVE MODE WOULD INDICATE SOME MULTICELLS AND OR ISOLD
SUPERCELLS...POTENTIALLY CONGEALING INTO CLUSTERS AND LINES. THE
SATELLITE TRENDS WILL BE MONITORED CAREFULLY.

OUR LOCAL WRF SHOWS A FEW CLUSTERS DEVELOPING IN THE 0-3 KM
COLUMNAR REF PRODUCT IN THE EARLY TO MID PM...AND CONTINUING OVERNIGHT.
THE EXPERIMENTAL HRRR INDICATES LATE PM/EARLY PM.W

PWATS WILL CONTINUE TO RUN A FEW STANDARD DEVIATIONS ABOVE NORMAL
WITH VALUES OF 1.25-1.75 INCH RANGE...SO SOME HEAVY DOWNPOURS ARE POSSIBLE.

OVERALL..THE SLIGHT RISK FOR OUR AREA LOOKS FINE...AND WE WILL
CONTINUE TO MONITOR THE NEAR TERM TRENDS. MAX TEMPS IN THE M70S TO
M80S LOOK FINE FOR NOW.

CONVECTION WILL CONTINUE INTO THE EVNG HOURS AND DIM OVERNIGHT AS
FCA IS FIRMLY IN WARM SECTION. LOWS AND TD WILL BE IN THE
60S...AND AREAS OF PATCHY FOG POSSIBLE IN THE MORNING.
-- End Changed Discussion --

&&

.SHORT TERM /THURSDAY THROUGH SATURDAY NIGHT/...
THU AND THU NT 500HPA TROF STARTS MOVING E THROUGH GRTLKS AS SFC
LOW ORGANIZES ALONG SEMI-STALLED FRONT FROM FM LK ERIE UP ST
LAWRENCE VLY. THIS SYSTEM PUSHES SLOWLY EAST DRAGGING A CDFNT TO
BTV-SYR LINE THU AFTN...AND THROUGH FCA BY 12UTC FRI. NAM/GFS IN
PRETTY CLOSE AGREEMENT WITH THIS TIMING. WHILE THERE IS INCRG
DYNAMICS WITH APPROACHING JET AND TROF...CAPES 1000-1500 ...CLOUDS
WILL BE WIDESPREAD HOLDING MAX TEMPS TO MID 70S TO AROUND 80. SPC HAS
ONLY PUT AREA IN SEE TEXT ATTM...WITH LOW PROBS DUE TO LIMITED INSTABILITY.
REGARDLESS AREA WILL SEE PERIOD OF -SHRA/TSTMS INCRG THU...TRANSITIONING
TO -SHRA/-RA BEHIND THE CDFNT OVERNIGHT.

BY FRI MORNING CDFNT WILL BE IN I-95 CORRIDOR ALONG THE ATLC
COAST. 500HPA TROF WILL BE MOVING INTO NE USA...AND BOTH MODELS
DEVELOP A MODEST SFC LOW OVER NJ. THE WARMTH OF PAST FEW DAYS
WILL GIVE WAY TO A COOL BREEZY WITH -SHRA FRI. FINALLY SFC LOW
MOVES OFFSHORE FRI NT AS HIGH PRESSURE BUILDS INTO THE GRTLKS.
HWVR THE 500HPA TROF LINGERS AND CUTS OFF OVER NEW ENG SAT.
BETWEEN THESE TWO SYSTEMS A BRISK NW GRADIENT WILL DRIVE SOME
PRETTY COOL AIR INTO THE REGION FOR LATE MAY. WITH 500HPA CUT OFF
LINGERING SKIES MAY ONLY BE PS SAT IN GFS.

TEMPS WILL PROBABLY GO NOWHERE FRI...ONLY COMING OFF MORNING LOWS
A FEW DEG...OR HOLDING STEADY.

THE GFS/NAM ARE PROGRESSIVE WITH SFC LOW DEPARTING THE COAST FRI
NT...WITH ITS 500 HPA TROF CROSSING REGION SAT AND DEPARTING SAT
NT WITH PC SKIES AND A RATHER BRISK WIND GRADIENT.

THE 00UTC ECMWF CUTS OFF THE 500HPA LOW OVER NJ...DEVELOPS A
COASTAL LOW...WHICH LINGERS ALONG THE EAST COAST FOR THE WEEKEND
WITH PERIODS OF RAW CHILLY RAIN.

THE GFS TEMPS WOULD BRING MINS SAT MORNING INTO THE MID 30S TO
MID 40S WITH SOME NEAR 30 AND POTENTIAL FROST/FREEZE ISSUES IN
ADRNDKS. HIGHS SAT WILL ONLY REBOUND EVEN WITH THE STRONG SUN TO
THE 60S. LOWS SAT NIGHT WOULD AGAIN BE IN THE 30S. WINDS WILL
REMAIN BRISK. ECMWF WOULD RESULT IN SLIGHTLY WARMER NIGHT TIME
TEMPS AND COOLER YET DAYTIME TEMPS IN MID 50S TO LOW 60S. HPC
LEANS TWRD A BLEND WITH CHC POPS LINGERING INTO SAT. IT WILL BE A
FALL LIKE MEMORIAL DAY WEEKEND.

WILL LEAN TWRD GFS/HPC BLEND THROUGH SAT.

&&

.LONG TERM /SUNDAY THROUGH TUESDAY/...
THE ECMWF KEEPS THE 500HPA CUTOFF OVER RGN AND SFC LOW NEAR NEW
ENGLAND COAST FOR A RAW CHILLY WEEKEND...FINALLY CLEARING ON
MONDAY. HWVR AT THIS TIME ITS TO BE CONSIDERED AN OUTLIER.

GFS/NAM/HPC PROGRESSIVELY MOVE THIS SYSTEM ALONG. 17 OF 20
MEMBERS OF THE GEFS ENSEMBLE KEEP IT DRY FROM FRI NIGHT ONWARD.
ONLY 3 HAVE ANY QPF. SO THE WORST CASE IN THE GFS IS SOME CLOUDS
FOR SUNDAY MRNG. OVERALL THE SFC HIGH BUILDS INTO THE GRTLKS
SHIFTING SLOWLY EAST TO FCA BY TUES. AT 500 HPA RIDGE BUILDS FROM
GRT PLAINS TO GRTLKS.

PERIOD WILL START OFF PARTLY CLOUDY W/BLO NORMAL TEMPS AND A BREEZE
CONTINUING SUNDAY. SCT FROST AND FREEZE WILL BE POSSIBLE IN THE
HIR TRRN. IN TIME THIS WILL GIVE WAY TO BRILLIANT SUNSHINE MONDAY
AND TUESDAY...LIGHT WINDS AND TEMPS RETURNING TO NORMAL MONDAY AND
ABV BY TUESDAY AND WED.

WILL POPULATE WITH HPC MIDNIGHT SHIFT GUID.

THE GROWING SEASON IS UNDERWAY ACROSS THE MID HUDSON VALLEY...
GREATER CAPITAL DISTRICT...LAKE GEORGE SARATOGA REGION...THE
MOHAWK VALLEY...EASTERN CATSKILLS...TACONICS...BERKSHIRES...BENNINGTON
AND EASTERN WINDHAM COUNTIES VT AND LITCHFIELD COUNTY. IT WILL
START ON MAY 25TH FOR THE SOUTHERN ADIRONDACKS AND WESTERN WINDHAM
COUNTY.

&&

.AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
SOME LOW CLOUDS ARE AFFECTING MOST OF THE TAF SITE THIS
MORNING...WITH IFR SCATTERED VARIABLE BROKEN AT KALB...SOLID IFR
AT KPSF AND KGFL AND SOLID MVFR AT KPOU. SOME FOG IS OCCURRING AT
KPSF. THE LOW CLOUDS AND FOG SHOULD LIFT BTWN 13-15Z...LEAVING A
MIX OF CLOUDS ABOVE 3000 FEET AGL FOR THE REST OF THE DAY AT ALL
SITES.

THUNDERSTORMS SHOULD DEVELOP AGAIN THIS AFTERNOON AND CONTINUE MUCH
OF TONIGHT...BUT DUE TO THE SCATTERED NATURE...JUST PUTTING VCSH
UNTIL REGIONS OF THUNDERSTORM DEVELOPMENT CAN BE OBSERVED AND
MOVEMENT CAN BE TRACKED LATER TODAY.  WHEREVER THUNDERSTORMS
OCCUR...MVFR AND IFR CONDITIONS WILL OCCUR BUT AGAIN...SCATTERED
NATURE TO THUNDERSTORMS PREVENTING ACKNOWLEDGING IN TAFS FOR NOW.

WINDS SHOULD BE SOUTH TO SOUTHWEST AT 10 KT OR LESS TODAY...
DIMINISHING TO LESS THAN 10 KT TONIGHT.

OUTLOOK...
THU...MVFR WITH IFR POSSIBLE. -SHRA/-TSRA LIKELY.
THU NIGHT...VFR/MVFR. CHC -SHRA/-TSRA ESPECIALLY IN THE EVNG.
FRI...MAINLY VFR. CHC -TSRA MAINLY IN THE AM.
SAT-SUN...VFR. NO SIG WX.

&&

.FIRE WEATHER...
NO FIRE WEATHER CONCERNS THROUGH FRIDAY. OCCASIONAL SHOWERS AND
THUNDERSTORMS WILL CONTINUE THROUGH THURSDAY NIGHT. SHOWERS WILL
CONTINUE INTO FRIDAY.

RH VALUES WILL INCREASE TO 85 TO 100 PERCENT TONIGHT...AND
THURSDAY NIGHT...AND LOWER TO 45 TO 60 PERCENT THIS AFTERNOON.

WINDS WILL MAINLY LESS THAN 10 MPH THROUGH TONIGHT...BECOMING
SOUTHWEST AROUND 10MPH THURSDAY.

&&

.HYDROLOGY...
PWATS ON THE ORDER OF 1.5 TO 2.0 INCHES NEXT FEW DAYS. WHILE
WIDESPREAD FLOODING IS NOT ANTICIPATED...LOCALLY HEAVY RAINFALL IN
THUNDERSTORMS AND TRAINING COULD RESULT IN SMALL STREAM AND URBAN
FLOODING OVERNIGHT AND AGAIN THIS AFTERNOON. SIGNIFICANT WITHIN
BANK RISES ARE LIKELY IN LARGER RIVERS.

3-HR ZONAL FFG VALUES ARE GENERALLY IN THE 2.5-3.0 INCH RANGE AT
THIS TIME...WHICH ARE HIGH FOR MID TO LATE MAY.

DUE TO THE SCATTERED NATURE OF THE SHOWERS AND THUNDERSTORMS...
BASIN AVERAGE QPF WILL BE HIGHLY VARIABLE THIS WEEK. THE BEST
THREAT FOR SEEING SIGNIFICANT AMOUNTS OF SHOWERS OR THUNDERSTORMS
WILL THIS AFTERNOON INTO THURSDAY NIGHT.

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...SNYDER/WASULA
NEAR TERM...SNYDER/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...NAS/WASULA
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER