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Area Forecast Discussion
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000
FXUS61 KOKX 020254
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
1054 PM EDT MON SEP 1 2014

.SYNOPSIS...
WEAK HIGH PRESSURE REMAINS OVER THE REGION TONIGHT IN THE WAKE OF A 
SURFACE TROUGH. A COLD FRONT THEN APPROACHES DURING TUESDAY BEFORE 
PASSING THROUGH TUESDAY NIGHT. HIGH PRESSURE BUILDS IN FOR THE LATTER 
HALF OF THE WEEK. ANOTHER COLD FRONT WILL IMPACT THE REGION THIS
WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
SOME MINOR ADJUSTMENTS WERE MADE WITH TEMPS AND DEWPOINTS.
SLIGHTLY BUMPED UP TEMPS WITH HIGHER DEWPOINTS IN PLACE AND
INCREASING CLOUDS FROM THE WEST WELL AHEAD OF NEXT UPPER LEVEL
TROUGH. PATCHY FOG ALREADY STARTING TO DEVELOP AND EXPECTING MORE
OF THIS TOWARDS DAYBREAK TUESDAY WITH LOW LEVELS STAYING MOIST.

MULTIPLE MESOSCALE MODELS INDICATE MOSTLY DRY CONDITIONS THROUGH
THE REST OF THE NIGHT. DRIER UPPER LEVELS AND LESS SHEAR ALONG WITH
STABLE CONDITIONS WILL LIMIT ANY SHOWER DEVELOPMENT. AT THIS POINT
SHOWERS WERE REMOVED FOR THE FORECAST COVERING THE REST OF TONIGHT
WITH ANY PROBABILITY OF SHOWERS BEING AT MOST AROUND 10 PERCENT.

&&

.SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/...
COLD FRONT APPROACHES DURING THE DAY TUESDAY. A PRE-FRONTAL TROUGH 
AHEAD OF IT DEVELOPS NEAR OUR WESTERN ZONES. SHOWER/TSTM THREAT 
BEGINS IN THE AFTERNOON ALONG THIS TROUGH...AND ENDS FOR MOST SPOTS 
OVERNIGHT WHEN THE TRAILING COLD FRONT PASSES THROUGH. CAPPED POPS 
IN THE CHC CATEGORY. PARAMETERS DURING THE AFTERNOON AND EARLY 
EVENING SUPPORT THE POTENTIAL OF THUNDERSTORMS WITH STRONG WIND 
GUSTS. LARGE HAIL WOULD BE LESS OF POSSIBILITY DUE TO RELATIVELY 
HIGH WBZ/FREEZING LEVEL HEIGHTS. TSTM STRENGTH DIMINISHES AFTER 
EARLY EVENING WITH LESS CAPE IN SPITE OF BETTER LIFT FROM THE 
PASSING COLD FRONT. PWATS STILL RATHER HIGH...SO HEAVY DOWNPOURS 
POSSIBLE IN ANY SHOWER.

ABOVE NORMAL TEMPERATURES WITH MUGGY CONDITIONS CONTINUE THROUGH 
THIS PERIOD. WITH 850MB TEMPS OF 17-18C...PARTLY TO MOSTLY SUNNY 
CONDITIONS FOR MOST OF THE DAY AND A SW FLOW...EXPECTING PARTS OF NE 
NJ TO REACH INTO THE LOW-MID 90S...WITH LOW 90S IN THE CITY AND A 
GOOD PORTION OF THE LOWER HUDSON VALLEY. MOST OTHER SPOTS EXPECTED 
TO END UP AT 85-90. REGARDING HEAT ADVISORY CONCERNS IN THE 
CITY...ALTHOUGH IT APPEARS THAT A DECENT PORTION OF THE CITY WILL 
REACH A HEAT INDEX OF AT LEAST 95 FOR AN HOUR OR TWO TOMORROW 
AFTERNOON...INDICES HAD FAILED TO REACH 95 MONDAY AFTERNOON. NO 
ADVISORIES WILL THEREFORE BE POSTED AS PER LOCAL POLICY.

THERE IS A MODERATE RISK OF RIP CURRENTS ON TUESDAY.

&&

.LONG TERM /WEDNESDAY THROUGH MONDAY/...
COLD FRONT OFFSHORE WILL CONTINUE TO PUSH EAST ON WEDNESDAY AS HIGH 
PRESSURE BUILDS IN. DRY CONDITIONS ARE EXPECTED THROUGH FRIDAY AS 
THE CENTER OF THE HIGH MOVES OVER THE REGION AND OFF THE EAST COAST 
BY THURSDAY WHILE ALOFT THERE WILL BE A RATHER ZONAL PATTERN. 
HUMIDITY LEVELS DURING THIS PERIOD WILL EASE UP A BIT AS DEWPOINTS 
DROP TO THE LOWER 60S ON WEDNESDAY...WITH SOME UPPER 50S DEWPOINTS 
POSSIBLE ON THURSDAY. HOWEVER...THEY CREEP BACK UP TOWARDS THE LOWER 
AND MIDDLE 60S AGAIN ON FRIDAY ON THE RETURN FLOW WITH THE HIGH 
OFFSHORE. 

A COLD FRONT WILL APPROACH THE AREA FRIDAY NIGHT INTO 
SATURDAY...PUSHING OFFSHORE SOMETIME SATURDAY NIGHT. THERE IS SOME 
MODEL CONSENSUS ON PUSHING THE COLD FRONT OFFSHORE SATURDAY 
NIGHT...BUT THERE ARE DIFFERENCES THEREAFTER. THE 00Z ECMWF STALLS 
THE FRONT JUST OFFSHORE AND THERE WOULD BE A CHANCE FOR POST-FRONTAL 
RAIN THROUGH SUNDAY NIGHT. THE 12Z GFS AND CMC KEEP THE SYSTEM 
PROGRESSIVE...ENDING THE RAIN SATURDAY NIGHT...KEEPING SUNDAY DRY. 
GFS ENSEMBLE MEAN IS ACTUALLY MORE PROGRESSIVE WITH THE COLD 
FRONT...PUSHING IT OFFSHORE DURING THE DAY SATURDAY...BUT ALSO ENDS 
IT SATURDAY NIGHT. ALSO...MODELS DIFFER IN DEVELOPMENT AND PLACEMENT 
OF LOW PRESSURE ALONG THE FRONTAL BOUNDARY...WHICH LEAD TO LARGE 
DIFFERENCES IN PLACEMENT OF ANY HEAVY RAINFALL. ALTHOUGH THE GFS IS 
MORE PROGRESSIVE...THE FRONT HAS SLOWED DOWN SIGNIFICANTLY FROM THE 
PREVIOUS 06Z RUN. SO...GIVEN UNCERTAINTY WILL KEEP AT LEAST SLIGHT 
CHANCE POPS IN FOR SUNDAY MORNING...DRYING OUT BY THE AFTERNOON. 

TEMPERATURES WILL BE ABOVE NORMAL THROUGH SATURDAY. 
THEREAFTER...BELOW NORMAL TEMPERATURES EXPECTED AS A CONTINENTAL 
POLAR AIRMASS BUILDS IN.

&&

.AVIATION /03Z TUESDAY THROUGH SATURDAY/...
A SURFACE TROUGH WILL DISSIPATE AS IT MOVES EAST OVERNIGHT. A
COLD FRONT APPROACHES LATE TUESDAY.

MVFR/IFR STRATUS/FOG LIKELY ALONG EASTERN TERMINALS...POSSIBLE
ACROSS INTERIOR TERMINALS.

ANY STRATUS/FOG SHOULD BURNS OFF IN THE MORNING...WITH VFR CONDS
IN AFT.

LIGHT SW WINDS TONIGHT INTO TUESDAY MORNING...GIVING WAY TO
AFTERNOON SEABREEZE DEVELOPMENT ALONG THE COAST.

INCREASING CHANCE FOR SCT SHRA/TSRA TUE EVENING ACROSS NYC
TERMINALS AND TO THE W & NW WITH APPROACHING COLD FRONT.

.OUTLOOK FOR 00Z WED THROUGH FRI...
.TUE NIGHT...MAINLY VFR EXCEPT FOR SCATTERED EVE/NIGHTTIME SHRA/TSRA.
.WED-FRI NIGHT...VFR CONDITIONS ARE EXPECTED.
.SAT...SUB VFR POSSIBLE IN SCATTERED SHRA/TSRA.

&&

.MARINE...
SUB-SCA CONDITIONS EXPECTED ON THE WATERS THROUGH THE FORECAST 
PERIOD WITH A RELATIVELY WEAK PRESSURE GRADIENT MOST OF THE TIME. 
THERE COULD BE SHOWERS AND TSTMS TUESDAY NIGHT...AND AGAIN LATE 
FRIDAY INTO SATURDAY AS A FRONT APPROACHES.

&&

.HYDROLOGY...
ISO/SCT SHOWERS/TSTMS LATE TUESDAY/TUES NIGHT WOULD LIKELY RESULT
IN NO MORE THAN LOCALIZED MINOR URBANIZED/SMALL STREAM FLOODING.

NO HYDROLOGIC ISSUES EXPECTED WEDNESDAY THROUGH THE WEEKEND.

&&

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

&&

$$
SYNOPSIS...JC/JP
NEAR TERM...JM
SHORT TERM...JC
LONG TERM...JP
AVIATION...NV
MARINE...JC/JP
HYDROLOGY...JC/JP








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