Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 050731
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
331 AM EDT TUE MAY 5 2015

.SYNOPSIS...
A COLD FRONT WILL PASS LATE TODAY...STALLING SOUTH OF THE AREA
WEDNESDAY. HIGH PRESSURE BUILDS OVER THE REGION FOR THE END OF
THE WEEK...AND THEN SHIFTS OFFSHORE THIS WEEKEND. A COLD FRONT
WILL SLOWLY APPROACH FROM THE NORTH AND WEST LATE SUNDAY INTO
MONDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
SFC TROF WAS STRETCHED FROM CNTRL NEW ENGLAND INTO NY STATE THIS
MRNG. THE PRES TROF WILL SLOWLY DROP THRU TODAY...BUT THE COLD
FRONT AND COOLER AIRMASS WILL NOT ARRIVE TIL TNGT. SLY COMPONENT
FLOW AHEAD OF THE TROF...KEEPING TEMPS COOL AT THE COASTS AND MILD
INTERIOR. AFTER THE TROF PASSES...TEMPS WILL SHOOT UP AT THE
COASTS AS NW FLOW MIXED DOWN THE WARMER AIR WITH OFFSHORE FLOW. IT
APPEARS A SEA BREEZE THEN DEVELOPS LATE IN THE AFTN WITH THE WEAK
PRES FIELD. NOT MUCH MOISTURE IN PLACE OR AVAILABLE PER STLT.
DEWPOINTS ARE IN THE 40S. IT THEREFORE LOOKS LIKE IT WILL BE
FAIRLY STABLE TODAY...BETWEEN THE MARINE INFLUENCE...AND WHEN THIS
MARINE INFLUENCE IS LIMITED...THE DRY AIR. AS A RESULT...HAVE
REMOVED TSTMS FROM THE FCST AND LOWERED POPS FOR SHWRS TO AROUND
20 PERCENT. DID NOT WANT TO GO COMPLETELY DRY DUE TO THE AREAS OF
SFC CONVERGENCE. WENT CLOSE TO THE NAMDNG5 FOR TEMPS.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
THE BEST CHC FOR PCPN COMES LATE TNGT AND WED MRNG. REMNANT MCS
APPEARS TO BE THE TRIGGER AND ADDITIONAL MOISTURE SOURCE. THERE
COULD BE ENOUGH ELEVATED INSTABILITY DUE TO THE THETAE ADVECTION
TO ALLOW FOR AN ISOLD TSTM. OTHERWISE...THE SLUGGISH SFC FRONT
JUST S OF THE CWA WILL CONTINUE TO PRODUCE WEAK CONVERGENCE...SO
HAVE KEPT SCHC FOR SHWRS FOR THE REST OF THE TIME. COOLER WITH NE
FLOW DEVELOPING BEHIND THE FRONT. TEMPS CLOSE TO GMOS25.

&&

.LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
THE SYNOPTIC PATTERN FOR THE LONG TERM PERIOD OVER THE NORTHEASTERN
UNITED STATES WILL BE DOMINATED BY DEEP LAYERED RIDGING ALOFT.
SURFACE HIGH PRESSURE BUILDS ON THURSDAY AND THEN BEGINS TO SLIDE
OFFSHORE FRIDAY INTO THE WEEKEND. SOUTHWESTERLY FLOW AROUND THE HIGH
TRANSPORTS WARMER AIR INTO THE REGION THIS WEEKEND. THIS PATTERN
BRINGS ABOVE NORMAL TEMPERATURES AND MAINLY DRY CONDITIONS.

THE NEXT FRONTAL SYSTEM SETS UP TO OUR NORTHWEST LATE THIS WEEKEND.
THERE APPEARS TO BE A VERY WEAK PUSH OF THE FRONT SOUTH WITH RIDGING
HOLDING STRONG OVER THE WESTERN ATLANTIC SUNDAY INTO MONDAY. THE 00Z
GFS WEAKENS THE RIDGE ENOUGH ON SUNDAY FOR THE FRONT TO SINK INTO
THE AREA. THE 00Z ECMWF AND 00Z CMC KEEP THE RIDGE STRONGER...AND
THIS HAS AGREEMENT WITH THE 00Z GEFS MEAN. HAVE SIDED WITH A SLOWER
PROGRESSION OF THE FRONT WITH THIS FORECAST PACKAGE. WITH THIS IN
MIND...POPS INCREASE TO LOW CHANCE BY MONDAY FOR SHOWERS AND
THUNDERSTORMS AS THE FRONT MOVES CLOSER TO THE REGION.

TEMPERATURES THURSDAY AND FRIDAY WILL RANGE FROM THE LOWER 70S NEAR
THE COAST TO THE MIDDLE AND UPPER 70S IN THE CITY AND POINTS NORTH
AND WEST. FOR SATURDAY AND SUNDAY...HIGHS WILL WARM INTO THE UPPER
70S AND LOWER 80S AWAY FROM THE COAST. AFTERNOON SEA BREEZES WILL
KEEP COASTAL LOCATIONS IN THE LOWER TO MIDDLE 70S. WITH A BIT MORE
CLOUD COVER AND POSSIBLE SHOWERS/STORMS MONDAY...HIGHS WILL BE A BIT
COOLER THAN THE WEEKEND IN THE LOWER TO MIDDLE 70S.

&&

.AVIATION /08Z TUESDAY THROUGH SATURDAY/...
A WEAK FRONTAL BOUNDARY APPROACHING FROM THE NORTHWEST WILL SLOWLY
DROP THROUGH THE AREA THIS MORNING REMAINING IN THE VICINITY
THROUGH THE EVENING.

VFR THROUGH 06Z WED. WITH THE FRONTAL BOUNDARY IN THE VICINITY
THE WIND FORECAST AT ALL THE TERMINALS WILL BE TOUGH AND HAVE LOW
TO MODERATE CONFIDENCE...ESPECIALLY AFT 12Z. FLOW LIGHTENS THIS
AFTN WITH SEABREEZES EXPECTED AT MOST OF THE COASTAL TERMINALS.
LOWER CONFIDENCE THAT IT WILL MAKE IT TO KEWR/KTEB SO HAVE LEFT
OUT FOR NOW.

THERE IS LITTLE FORCING WITH THE FRONT AND MUCH OF THE GUIDANCE IS
SHOWING VERY ISOLD TO NO SHOWERS THROUGH 06Z WED. THEREFORE HAVE
REMOVED ANY MENTION OF PCPN AND THUNDER.

VAD WIND PROFILES INDICATING WINDS OF 50-60 KT BETWEEN
1-2KFT...5-10 KT HIGHER THAN ANY GUIDANCE IS SHOWING. HAVE ADDED
LLWS TO NYC TERMINALS...KISP/KBDR/KGON THROUGH 08-10Z...W TO E.

.OUTLOOK FOR 06Z WEDNESDAY THROUGH SATURDAY...
.TONIGHT THROUGH SATURDAY...VFR.

&&

.MARINE...
SEAS ARE JUST BLW 5 FT S OF FIRE ISLAND...AND ABOUT A FT BLW
ELSEWHERE ON THE OCEAN. IN ADDITION...THE COLD STABLE WATERS ARE
LIMITING WIND GUSTS PER THE BUOY DATA. AS A RESULT...HAVE
CANCELLED THE SCA. WITH A COLD FRONT SETTLING OVER THEN S OF THE
WATERS TNGT AND WED...WINDS AND SEAS WILL STAY BLW SCA LVLS. HIGH
PRESSURE WILL MOVE OVER THE WATERS THURSDAY THROUGH SATURDAY
ALLOWING FOR SUB SCA CONDITIONS. A FEW 20 KT GUSTS ARE POSSIBLE
FRIDAY AND SATURDAY AFTERNOON ACROSS THE NEAR SHORE WATERS DUE TO
AFTERNOON SEA BREEZES.

&&

.HYDROLOGY...
BASIN AVE RAINFALL OF AROUND A HALF INCH IS POSSIBLE LATE TNGT
INTO EARLY WED IF A REMNANT CONVECTIVE COMPLEX IMPACTS THE REGION.
OTHERWISE...PCPN WILL BE SCT AND LGT. MAINLY DRY CONDITIONS ARE
EXPECTED THURSDAY THROUGH THE WEEKEND. CHANCES FOR SHOWERS AND
THUNDERSTORMS BEGIN TO SUNDAY NIGHT INTO MONDAY.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.

&&

$$
SYNOPSIS...JMC/DS
NEAR TERM...JMC
SHORT TERM...JMC
LONG TERM...DS
AVIATION...
MARINE...JMC/DS
HYDROLOGY...JMC/DS



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