Area Forecast Discussion Issued by NWS Albany, NY
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000
FXUS61 KALY 231438
AFDALY
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE ALBANY NY
1038 AM EDT THU MAY 23 2013
.SYNOPSIS...
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A COLD FRONT WILL MOVE SLOWLY ACROSS THE REGION THIS
AFTERNOON INTO TONIGHT...AND STALL ALONG THE ATLANTIC SEABOARD
FRIDAY. LOW PRESSURE WILL ORGANIZE...INTENSIFY...AND LINGER ON THIS
FRONT NEAR THE NEW ENGLAND COAST MUCH OF THE WEEKEND. HIGH PRESSURE
WILL BUILD INTO THE EASTERN GREAT LAKES MEMORIAL DAY AND DRIFT OVER
OUR REGION INTO MIDWEEK WITH FAIR AND DRY WEATHER.
&
.NEAR TERM /THROUGH TONIGHT/...
AS OF 1030 AM EDT...A COLD FRONT REMAINS WEST OF THE REGION OVER
THE OHIO VALLEY AND THE EASTERN GREAT LAKES REGION THIS
MORNING...WITH A PREFRONTAL TROUGH MOVING ACROSS W-CNTRL NY AND
PA. THIS PREFRONTAL TROUGH IN THE WARM SECTOR HAS PRODUCED SCT
SHOWERS OVER THE SRN DACKS AND W-CNTRL MOHAWK VALLEY...AND OTHER
SHOWERS HAVE BLOSSOMED OVER THE LOWER TO MID HUDSON VALLEY IN
ADVANCE OF THE MID LEVEL SHORT-WAVE. POPS HAVE BEEN READJUSTED TO
LIKELY VALUES OVER THE SRN TIER.
THE SATELLITE PICTURE IS CLUTTERED WITH CLOUD COVER WHICH WILL
INHIBIT WIDESPREAD CONVECTION AT THIS TIME. DEWPTS REMAIN IN THE
U50S TO M60S...SO ANY HOLES IN THE CLOUD COVER MAY ALLOW SBCAPES
VALUES OF 500-1000 J/KG TO DEVELOP. THE MID LEVEL LAPSE RATES LOOK
POOR AT THIS TIME...BUT THE BETTER UPPER LEVEL JET DYNAMICS ARRIVE
IN THE LATE PM AND EVENING /OUR FORECAST AREA GETS IN THE RIGHT
REAR QUADRANT OF THE JET STREAK/...AND THE DEEP SHEAR STRENGTHENS TO
40-50 KTS...ESPECIALLY FROM THE CAPITAL REGION NORTHWARD BTWN 18Z-
00Z. THE AMOUNT OF HEATING AND SFC DESTABILIZATION REMAINS THE
QUESTION FOR THE POSSIBILITY OF SEVERE THUNDERSTORMS. NO ENHANCED
WORDING IN THE ZONES AND GRIDS YET. SOME MULTICELLS EVOLVING INTO
LINES AND BANDS LOOK POSSIBLE BASED ON THE MODEL SOUNDINGS AND
HODOGRAPHS.
THE FLASH FLOOD WATCH REMAINS UP FOR THE NRN HALF OF THE FCST
AREA. ZONAL FFG VALUES IN THE 1/3/6 HR TIME FRAME HAVE LOWERED TO
1-2 INCHES OVER PORTIONS OF THE CAPITAL REGION AND SRN VT DUE TO
THE HEAVY RAINS THE PAST FEW DAYS. THE SLOW MOVEMENT OF THE
BOUNDARY COUPLED WITH THE ANOMALOUS PWAT VALUES COULD PRODUCE SOME
FLASH FLOODING IN A FEW SPOTS.
TEMPS LOOK ON TRACK WITH MAXES IN THE 70S TO AROUND 80.
SHOWERS AND THUNDERSTORMS SHOULD EVOLVE INTO JUST AN AREAS OF STEADY
RAIN LATE TONIGHT AS THE LOW LEVEL COOLING GRADUALLY SPREADS
EAST...AND THE STRENGTHENING UPPER FEATURE BEGINS TO CUT OFF AND
TRACK ALONG THE NORTHEAST COAST TOMORROW INTO THE WEEKEND.-- End Changed Discussion --
&&
.SHORT TERM /FRIDAY THROUGH SUNDAY NIGHT/...
THE TREND THAT BEGAN APPEARING IN THE MODEL SUITE TWO DAYS AGO...IS
NOW CONSENSUS FOR THE WEEKEND. 00 UTC GFS/NAM/ECMWF HAVE CDFNT
STALLING ALONG I-95 CORRIDOR BY FRI MORNING. SHARP 500HPA TROF FM
QB TO APPALACHIANS MOVING EAST...AS SERIES OF SHORT WAVES DIVE
SOUTHWARD INTO IT AND CUT IT OFF.
DURING FRI IT CUTS OFF OVER THE MID ATLC STATES...COASTAL
CYCLOGENISUS ENSUES OFF LONG ISLAND...AND THE SLOWLY DEEPENING SFC
LOW AND THE 500HPA CUT OFF BCMG VERTICAL OFF S NEW ENG COAST
SAT...THEN DRIFT SLOWLY N SUNDAY INTO GULF OF MAINE.
NEEDLESS TO SAY THIS IS GOING TO FEEL MORE LIKE A LATE OCTOBER
WEEKEND IN THE NORTHEAST. DURING FRIDAY -SHRA WILL TRANSITION TO
PERIODS OF RAIN IN ANNA TYPE FRONT BTWN SFC FRONT AND 500HPA AXIS.
AT SAME TIME GRADIENT BETWEEN 1031MB HIGH OVER MIDWEST...AND
DEEPENING SFC LOW OFF LONG ISLAND WILL RESULT IN A 14MB WIND
GRADIENT ACROSS NYS FRI & SAT. N WINDS WILL INCR TO 10-20 MPH AND
RESULT WILL BE A RAINY RAW FRI AND SAT.
GFS QPF OF 1-2.5 INCHES...ECMWF 0.75 TO 1.0 FRIDAY NIGHT THROUGH
SAT NT.
DURING THE DAY FRIDAY TEMPERATURES WILL JUST HOLD STEADY NEAR
MORNING LOWS...BEFORE FALLING DURING FRI AFTN IN STRONG CAA. THEY
WILL FALL FURTHER FRI NT INTO THE 40S WITH 30S IN WESTERN
PERIPHERY. SAT HIGHS WILL BE IN THE 50S AND LOW 60S WITH CLOUDS
AND PERIODS OF RAIN. MAX MIN TEMPS IN GUIDANCE ARE PROBABLY NOT
MUCH USE...AS ALOT OF NON-DIURNAL EFFECTS GOING ON FRI INTO SAT.
WILL USE 3 HOURLIES AND LET MAX/MINS FALL OUT.
OF NOTE IS THAT THE WESTERN EDGE OF THE PCPN/CLOUDS WITH THIS
SYSTEM WILL BE A VERY SHARP TRANSITION...SOMEWHERE ON THE WESTERN
PERIPHERY OF FCA. PCPN COULD BE SPOTTY OR NON-EXISTENT ALONG W
EDGE OF FCA...AND THERE MAY BE PERIODS OF THINNING CLOUDS WHICH
WOULD ALLOW TEMPS TO DROP TO NR FREEZING DURING MORNINGS.
SUN THE VERTICAL SYSTEM WILL CONTINUE TO DRIFT THROUGH THE GULF
OF MAINE...INTO THE MARITIMES SUN NT. THE GFS HAS CLOUDS AND -SHRA
DIM SUNDAY WITH INCRG SUN ALONG W PRTNS OF FCA. THE ECMWF KEEPS IT
CLOUDY AND WET INTO SUN EVENING. THE O6UTC NAM/GFS ARE A TAD MORE
PROGRESSIVE WITH THIS SYSTEM AND HAS CLOUDS AND RAIN ONLY FM HUD
VLY EAST SAT...AND THE SYSTEM CLEARLY EXITING REGION SAT NT.
FOR NOW FCST REFLECTS 00UTC MODEL SUITE TIMING...WITH SKIES FINALLY
CLEARING SUN NT ACROSS FCA AS 500HPA RIDGING BUILDS INTO THE GRTLKS
AND SFC HIGH BUILDS INTO E GRTLKS. BUT IF THE EMERGING TREND
CONTINUES ON LATER RUNS...CONDITIONS MIGHT NOTICEABLE IMPROVE
ACROSS FCA FOR SUNDAY.
&&
.LONG TERM /MONDAY THROUGH WEDNESDAY/...
AFTER A SOGGY HOLIDAY WEEKEND...THE CUTOFF AND SFC SYSTEM DEPART
AS RIDGE AT 500HPA BUILDS INTO GRTLKS AND SFC HIGH BUILDS FROM
GRTLKS TO CAROLINAS MONDAY. THIS PATTERN WILL SHIFT EAST AS LARGE
500 HPA RIDGE BUILDS OVER E USA AND SFC HIGH SETTLES OFF THE EAST
COAST. TEMPS WILL RETURN TO NR NORMAL MONDAY..AND BUILD UPWARD
INTO THE WEEK. FCA IN WAA REGIME THROUGHOUT. THE GFS BRINGS A
WMFNT AND CHC -SHRA/TSTMS LATE TUES AND WED...WHILE ECMWF KEEPS IT
DRY INTO THU. ONLY 6 MEMBERS OF THE GEFS ARE IN LINE WITH THE
OPERATIONAL RUN PCPN WED...THE REST OF THEIR PLUMES ARE FLAT
LINED. WPC HOLDS PCPN OFF TILL END OF EFP ON THUR. SO FOR NOW WILL
HAVE A FAIR WARM EFP...WITH A VERY NOTICEABLE WARMING TREND TO ABV
NORMAL TEMPS. WILL POPULATE WITH WPC FROM MIDNIGHT SHIFT.
&&
.AVIATION /15Z THURSDAY THROUGH MONDAY/...
SOME LOW CLOUDS AND FOG LINGERING FOR AN HOUR OR TWO AT KPOU AND PSF
THIS MORNING WITH MVFR/IFR CONDITIONS. OTHERWISE...SOME PARTIAL CLEARING
OVER EASTERN NY AND WESTERN NEW ENGLAND SHOULD LAST TO AROUND
16Z...WHEN SHOWERS AND THUNDERSTORMS COULD DEVELOP AND APPROACH
THE TAF SITES. THE ONE EXCEPTION IS KGFL WHERE A FEW SHOWERS MAY
IMPACT THE TERMINAL BTWN 12Z-14Z.
SINCE CURRENT SHOWER ACTIVITY IS WELL WEST...AND
THE TIMING OF DEVELOPMENT AND TRACKING OF THUNDERSTORMS IS SO
UNCERTAIN...JUST PUTTING GENERIC VCTS AT ALL SITES BETWEEN 16Z AND
22Z...AS MORE SPECIFIC TIMING WILL BE PROVIDED IN LATER TAF
ISSUANCES. STEADIER RAIN AND/OR THUNDERSTORMS SHOULD BE AROUND THE
AIRPORTS BY 22Z-24Z...SO LOWERED CONDITIONS AT ALL TAF SITES TO
MVFR CEILINGS AND VISIBILITIES IN SHOWERS FOR THIS EVENING AND
TONIGHT. AGAIN...UNCERTAINTIES IN HOW THE THUNDERSTORMS WILL
EVOLVE LATER THIS AFTERNOON AND EVENING...SO JUST INDICATING
SHOWERS. LATER TAF ISSUANCES WILL ADDRESS THE THUNDERSTORM TIMING.
WINDS ARE SOUTH TO SOUTHWEST AT AROUND 10 KT...WITH A FEW GUSTS
AROUND 15 KT EARLY THIS MORNING...AND SHOULD CONTINUE THROUGH THE
DAY. WINDS SHOULD TREND TO SOUTHWEST AND WEST AFTER MIDNIGHT TONIGHT
AS THE COLD FRONT TRACKS THROUGH.
OUTLOOK...
FRI...MAINLY VFR. CHC -TSRA MAINLY IN THE AM.
SAT-MON...VFR/MVFR. CHC -SHRA.
&&
.FIRE WEATHER...
NO FIRE WEATHER CONCERNS INTO SUNDAY. PERIODS OF RAIN...MODERATE
TO HEAVY AT TIMES WILL CONTINUE INTO THE HOLIDAY WEEKEND.
RH VALUES WILL INCREASE TO 85 TO 100 PERCENT TONIGHT...AND
FRIDAY NIGHT...AND LOWER TO 45 TO 60 PERCENT THURSDAY AFTERNOON
AND ONLY 60-80 PERCENT FRIDAY AFTERNOON.
WINDS WILL GENERALLY BE SOUTH AT 5 TO 10 MPH TODAY...TURNING NORTH
FRIDAY AND INCREASING TO 10 TO 15 MPH. .
&&
.HYDROLOGY...
ECMWF AND GFS VERY AGGRESSIVE IN BRINGING HEAVY RAINFALL INTO CWA
INTO THE MEMORIAL DAY WEEKEND. OPERATIONAL ECMWF AND GFS PRODUCE
2.50 TO 5.0 INCHES OF RAIN IN CWA INTO SUNDAY. GEFS SHOW AVERAGE
OF 2.0 INCHES THROUGH WEEKEND WITH 8 MEMBERS PUSHING IN EXCESS OF
3.5 INCHES.
FIRST CHALLENGE FOR HEAVY RAIN WILL COME WITH TODAYS SLOWLY MOVING
FRONT. EASTERN CWA AND CENTRAL CWA HAVE SEEN HEAVIEST RAIN OVER
THE LAST TWO DAYS AND WOULD APPEAR TO BE THE REGION WHERE FLASH
FLOOD THREAT IS AT HIGHEST. A FLASH FLOOD WATCH WILL BE ISSUED FOR
THESE AREAS.
&&
.ALY WATCHES/WARNINGS/ADVISORIES...
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CT...NONE.
NY...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR NYZ032-033-
038>043-047>054-082>084.
MA...NONE.
VT...FLASH FLOOD WATCH THROUGH FRIDAY MORNING FOR VTZ013>015.-- End Changed Discussion --
&&
$$
SYNOPSIS...SNYDER/WASULA
NEAR TERM...NAS/WASULA
SHORT TERM...SNYDER
LONG TERM...SNYDER
AVIATION...NAS/WASULA
FIRE WEATHER...SNYDER
HYDROLOGY...SNYDER