Area Forecast Discussion
Issued by NWS Upton, NY

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS61 KOKX 050025
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
825 PM EDT TUE AUG 4 2015

.SYNOPSIS...
A COLD FRONT WILL SLOWLY PASS THROUGH THE REGION TONIGHT...PUSHING
OFFSHORE EARLY WEDNESDAY. WEAK HIGH PRESSURE BUILDS INTO THE AREA
ON THURSDAY. LOW PRESSURE MAY IMPACT THE AREA FRIDAY INTO
SATURDAY. HIGH PRESSURE RETURNS FOR THE SECOND HALF OF THE
WEEKEND. A FRONTAL SYSTEM APPROACHES AND AFFECTS THE AREA FOR THE
BEGINNING OF NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
UPDATED THE POPS WITH SLIGHT CHANCE ACROSS THE NORTHERN TIER WHERE
SOME THUNDERSTORMS WERE NORTH OF THE FORECAST AREA...AND ALONG
OUTFLOW BOUNDARIES FROM CONVECTION MOVING THROUGH
MASSACHUSETTS...AND WHERE THERE IS BETTER SUPPORT.

ACROSS THE CWA...SUBSIDENCE STILL LIMITING INITIATION. LAPS AT
19Z HAD ABOUT 2500 J/KG SBCAPE ON LI...WITH ABOUT 1000-2000
REMAINDER OF THE AREA BASICALLY E OF THE HUDSON. CIN IS MINIMAL.
CU FIELD ON STLT BUT VERTICAL EXTENT LIMITED ACROSS THE CWA. ANY
FOCUS IN THIS MDT CAPE ENVIRONMENT COULD ALLOW ISOLD CELLS TO
BLOSSOM. WITH 40-50KT 0-6KM SHEAR...SVR POTENTIAL WITH ANY TSTMS.

BY THE TIME THERE IS A LITTLE MID LVL LIFT TNGT...THE AREA IS
MAINLY STABLE AND CAPPED. EXCEPTION IS EXTREME ERN LI PER THE NAM
WHERE THE CHC FOR ISOLD TSTM DEVELOPMENT LINGERS LATER INTO THE
EVE.

A BLEND OF GUIDANCE WAS USED FOR TEMPS...BUT LIMITED THE
RADIATIONAL COOLING SIGNATURE ACROSS THE PINE BARRENS OF LI WITH
THE BOUNDARY IN THE VICINITY.

HIGH RISK FOR RIPS CONTINUES THIS EVE WITH MANY REPORTS OF
DANGEROUS RIPS. A RIP CURRENT STATEMENT IS IN EFFECT.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
UPR JET DIVES INTO THE AREA BY AFTN. DESPITE LIMITED
INSTABILITY...THE NAM IS PICKING UP ON SCT-ISOLD CONVECTION INTO
THE EARLY EVE. THE GFS IS DRY. LAPSE RATES ARE SLIGHTLY STEEPER IN
THE NAM...WITH AROUND 8C BETWEEN H85-H7. THE GFS IS AROUND 7C IN
THE SAME LAYER. WITH THE APPROACHING COLD POOL ALOFT...JET AND
WARM SST/S...DID NOT DISCOUNT THE NAM AND HAVE THEREFORE INCLUDED
20 POPS FOR DIURNAL ACTIVITY. ISOLD LIGHTNING STRIKES TODAY INVOF
LAKES HURON AND ONTARIO LEND SOME SUPPORT TO TSTMS CHCS. TEMPS A
BLEND OF THE GUIDANCE WHICH WAS IN GOOD AGREEMENT.

THERE IS A MODERATE RISK FOR RIP CURRENTS AT THE OCEAN BEACHES
WEDNESDAY.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
UPPER LEVEL LOW OVER SOUTHEASTERN CANADA WILL PUSH EAST ON
THURSDAY...ALLOWING FOR ZONAL FLOW TO DEVELOP ALOFT. SURFACE HIGH
PRESSURE BUILDS IN AT THE SURFACE KEEPING THE AREA DRY.

COMPLICATED FORECAST THEREAFTER IN REGARDS TO THE POTENTIAL FOR LOW
PRESSURE IMPACTING THE AREA MAINLY FROM LATE THURSDAY NIGHT THROUGH
AT LEAST SATURDAY. THIS STORM WILL FORM FROM A SHORTWAVE CURRENTLY
OVER THE ROCKIES WHICH WILL EJECT OUT INTO THE MID-WEST WEDNESDAY
NIGHT INTO THURSDAY MORNING. THIS WILL ALLOW A WEAK SURFACE LOW TO
DEVELOP. THE TRACK OF THIS LOW THEREAFTER IS VERY UNCERTAIN. 12Z NAM
AND THE 00Z ECMWF SHARE A SIMILAR TRACK...BRINGING THE LOW OVER THE
OHIO VALLEY OVERNIGHT THURSDAY...OVER THE MID-ATLANTIC ON FRIDAY AND
OFF THE EAST COAST FRIDAY NIGHT INTO SATURDAY MORNING.
THEREAFTER...THE ECMWF PASSES SOUTH AND EAST LONG ISLAND SATURDAY.
THE 12Z GFS AND THE CANADIAN TAKE THE LOW OVER FARTHER SOUTH...OVER
VIRGINIA/NORTH CAROLINA...THEN TURNING NORTHEAST AND PASSING WELL
SOUTH AND EAST OF THE AREA...HUNDREDS OF MILES EAST OF THE 40/70
BENCHMARK...AND THUS HAVING NO IMPACT TO THE AREA WHATSOEVER. THE
00Z ECMWF ENSEMBLE MEAN FOLLOWS A SIMILAR TRACK TO THE
OPERATIONAL...BUT THERE IS A GOOD DEAL OF SPREAD AND THUS
UNCERTAINTY WITH THE LOW AS IT EJECTS OUT OF THE ROCKIES.
THEREFORE...EXPECT A GOOD DEAL OF DIFFERENCES IN MODELS SOLUTIONS
UNTIL THIS FEATURE MOVES OUT OF THE ROCKIES. GIVEN THE
UNCERTAINTY...WILL NOT MAKE MUCH IN THE WAY OF CHANGES WITH WHAT IS
CURRENTLY IN THE FORECAST.

ANOTHER CONCERN IS THE NEW 12Z ECMWF HAS SHIFTED FARTHER SOUTH THAN
THE PREVIOUS RUN...COMING MORE IN LINE WITH THE GFS AND
CANADIAN...MAKING THE NAM MORE OF AN OUTLIER. IF THIS TREND
CONTINUES WITH THE MODELS...THERE WOULD BE MUCH LESS IN THE WAY OF
RAINFALL.

&&

.AVIATION /00Z WEDNESDAY THROUGH SUNDAY/...
A COLD FRONT WILL MOVE EAST ACROSS THE AREA TONIGHT FOLLOWED BY
HIGH PRESSURE ON WEDNESDAY.

VFR WEATHER CONDITIONS WILL PREVAIL THROUGH WEDNESDAY.

W WINDS 10-15 KT WITH GUSTS JUST SHY OF 20 KT IN NYC METRO...AND
5-10 KT ELSEWHERE...SHOULD BECOME LIGHT AND VEER MORE NW
OVERNIGHT. W WINDS SHOULD PICK UP AGAIN BY AFTERNOON 10-15 KT
WITH GUSTS 15-20 KT...WITH SW SEA BREEZE ONLY AT KGON.

...NY METRO ENHANCED AVIATION WEATHER SUPPORT...

DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN
BE FOUND AT:  HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE)

KJFK FCSTER COMMENTS: UNSCHED AMD POSSIBLE EARLY THIS EVE IF WINDS
DIMINISH MORE QUICKLY THAN FCST.

KLGA FCSTER COMMENTS: UNSCHED AMD POSSIBLE EARLY THIS EVE IF WINDS
DIMINISH MORE QUICKLY THAN FCST.

KEWR FCSTER COMMENTS: UNSCHED AMD POSSIBLE EARLY THIS EVE IF WINDS
DIMINISH MORE QUICKLY THAN FCST.

KTEB FCSTER COMMENTS: UNSCHED AMD POSSIBLE EARLY THIS EVE IF WINDS
DIMINISH MORE QUICKLY THAN FCST.

KHPN FCSTER COMMENTS: HIGH CONFIDENCE.

KISP FCSTER COMMENTS: UNSCHED AMD POSSIBLE EARLY THIS EVE IF WINDS
DIMINISH MORE QUICKLY THAN FCST.

.OUTLOOK FOR 00Z THU THROUGH SUNDAY...
.WED NIGHT...VFR WITH W WINDS DIMINISHING AND SHIFTING NW.
.FRI-SAT...CHANCE OF MVFR OR LOWER CONDS IN RAIN.
WINDS BECOMING NE.
.SUNDAY...VFR.

&&

.MARINE...
FORECAST WINDS AND SEAS ON TRACK WITH NO CHANGES AT THIS TIME.

SEAS STILL IN THE 4-6 FT RANGE ON THE OCEAN. HAVE EXTENDED THE
SCA THRU TNGT BASED ON THESE OBS AND THE 12Z WAVEWATCH.
ELSEWHERE...GUSTS MAINLY IN THE LWR 20S EXPECTED THRU THIS EVE. AN
OCNL NEAR SHORE GUST TO 25KT POSSIBLE S SHORE BAYS AND HARBOR TIL
SUNSET. WINDS AND SEAS SUBSIDE TO BLW SCA LVLS ALL WATERS WED AND
WED NGT.

WEAK HIGH PRESSURE WILL MOVE OVER THE WATERS ON THURSDAY WITH LOW
PRESSURE ON FRIDAY INTO SATURDAY. SUB SCA CONDITIONS ARE EXPECTED
THURSDAY INTO FRIDAY...WITH SEAS BUILDING TO AROUND 5 FT ON THE
OCEAN SATURDAY INTO SATURDAY NIGHT WITH THE APPROACH OF THE LOW.
SEAS SUBSIDE SUNDAY AS THE LOW PUSHES AWAY FROM THE AREA.

&&

.HYDROLOGY...
ORGANIZED SIGNIFICANT RAINFALL IS NOT EXPECTED THROUGH THURSDAY.

A WIDESPREAD SIGNIFICANT RAINFALL IS POSSIBLE LATE THURSDAY INTO
FRIDAY. HOWEVER...UNCERTAINTY EXISTS IN WHERE AND WHEN THE HEAVIEST
OF THE RAIN WILL FALL. ANTECEDENT DRY CONDITIONS SHOULD LIMIT
FLOODING POTENTIAL. HOWEVER...ANY HEAVIER RAINFALL THAT DOES DEVELOP
WOULD HAVE THE POTENTIAL FOR LOCALIZED FLOODING.

&&

.EQUIPMENT...
TEWR TERMINAL DOPPLER RADAR REMAINS UNAVAILABLE.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HIGH RIP CURRENT RISK UNTIL 9 PM EDT THIS EVENING FOR NYZ075-
     080-081-178-179.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT WEDNESDAY FOR ANZ350-353-
     355.

&&

$$
SYNOPSIS...JMC/JP
NEAR TERM...MET
SHORT TERM...JMC
LONG TERM...JP
AVIATION...GOODMAN
MARINE...MET
HYDROLOGY...JMC/JP
EQUIPMENT...



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.