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Area Forecast Discussion
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000
FXUS61 KOKX 280054
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
854 PM EDT SUN JUL 27 2014

.SYNOPSIS...
A STRENGTHENING LOW PRESSURE SYSTEM WILL APPROACH THE REGION
TONIGHT AND THEN TRACK THROUGH NEW ENGLAND ON MONDAY AS THE COLD
FRONT MOVES ACROSS THE LOCAL AREA. COLD FRONT PUSHES EAST MONDAY
NIGHT...SETTLING WELL OFFSHORE THROUGH THE MIDDLE OF THE WEEK AS
HIGH PRESSURE BUILDS IN THE WAKE. LOW PRESSURE APPROACHES AGAIN
FOR NEXT WEEKEND.

&&

.NEAR TERM /UNTIL 6 AM MONDAY MORNING/...
MAIN CONCERN IS FOR TONIGHT AS A STRONG JET STREAK/POTENT
SHORTWAVE AND STRENGTHENING SFC LOW/PRE-FRONTAL TROUGH APPROACHING
TONIGHT...WITH ANOTHER ROUND OF SHRA/TSTMS EXPECTED OVERNIGHT. THE
STRONG FORCING AND A MODERATE DEEP/LOW LEVEL SHEAR ENVIRONMENT ARE
FAVORABLE FOR SEVERE WEATHER INTO THE OVERNIGHT...BUT THE LIMITING
FACTOR WILL BE AMOUNT OF INSTABILITY REMAINING OVERNIGHT. AT LEAST
ELEVATED MARGINAL INSTABILITY IS EXPECTED OVERNIGHT...BUT WITH
UNSEASONABLY STRONG LLJ THIS COULD APPROACH/REMAIN NEAR MODERATE
LEVELS. LOW/CAPE HIGH SHEAR ENVIRONMENTS ARE USUALLY NOT FAVORABLE
FOR WIDESPREAD SEVERE WEATHER COVERAGE...BUT WITH STRONG FORCING
AND IF LLJ CAN MAINTAIN HIGHER INSTABILITY A MORE WIDESPREAD
SEVERE EVENT IS POSSIBLE.

THE MAIN FOCUS FOR CONVECTION AFFECTING OUR AREA TONIGHT WILL BE 
ALONG AN APPROACHING PRE-FRONTAL TROUGH. WOULD EXPECT AT LEAST 
SCATTERED COVERAGE OF STORMS OR LINE SEGMENTS ALONG THIS 
BOUNDARY...BUT IF INSTABILITY REMAINS HIGHER...COVERAGE WOULD 
INCREASE AND COULD TAKE THE FORM OF A QLCS. MAIN THREAT WITH ANY
LINE SEGMENT OR QLCS WILL BE DAMAGING WINDS AND HEAVY RAIN...WITH
SUFFICIENT LOW-LEVEL SHEAR/HELICITY FOR STORM ROTATION AND A LOW
PROB OF A TORNADO. DISCRETE CELLS HAVE POTENTIAL TO ROTATE AND
PRODUCE LARGE HAIL AS WELL...BUT LOW CAPE/HIGH SHEAR ENVIRONMENTS
ARE NOT FAVORABLE FOR HAIL...SO THIS IS A LOW THREAT.

SO LOOKING FOR MAIN ACTIVITY LIKELY OCCURS AFTER MIDNIGHT FROM
NYC METRO AND POINTS WEST...AND AFTER 2-3 AM INTO LI/CT.

AS THE LOW TRACKS INTO SOUTHERN NEW ENGLAND LATE TONIGHT INTO
EARLY MONDAY MORNING...THE PRE-FRONTAL TROUGH WILL LIFT NE WITH
BEST FORCING/MOISTURE/INSTABILITY LIFTING N AND E...BRINGING AN
END TO THE WIDESPREAD SHRA/TSRA AND SVR THREAT.

&&

.SHORT TERM /6 AM MONDAY MORNING THROUGH 6 PM MONDAY/...
SURFACE LOW TRACKS THROUGH NEW ENGLAND ON MONDAY...WITH PRE-FRONTAL 
TROUGH MOVING NORTH AND RELATIVELY DRIER AIRMASS ADVECTING IN.

BREEZY AND SEASONABLY WARM CONDITIONS ARE EXPECTED. CONSIDERABLE
INSTABILITY CLOUD COVER AND DIURNAL SCT-NUM SHRA DEVELOPMENT
LIKELY IN THE AFTERNOON WITH COLD POOL INSTABILITY AND DIURNAL
HEATING...AS WELL AS ALONG AHEAD OF COLD FRONTAL PASSAGE IN
AFT/EVE. GREATEST COVERAGE EXPECTED ACROSS THE INTERIOR OFF HIGHER
TERRAIN. A FEW STRONG TO SEVERE STORMS ARE POSSIBLE...WITH HAZARDS
IN THE FORM OF LARGE HAIL AND GUSTY WINDS.

FRONT SHOULD CLEAR THE AREA MON EVE WITH DRIER AND COOLER AIRMASS 
ADVECTING IN.

THERE IS A MODERATE RISK FOR THE DEVELOPMENT OF RIP CURRENTS ALONG
THE ATLANTIC OCEAN FACING BEACHES DURING THE DAY MONDAY.

&&

.LONG TERM /MONDAY NIGHT THROUGH SUNDAY/...
LINGERING CHC FOR PCPN OVER SOUTHERN CT/LOWER HUDSON RIVER VALLEY 
FIRST HALF OF MON NIGHT AS SFC LOW LIFTS TO THE NORTH...DRAGGING ITS 
ASSOCIATED COLD FRONT THROUGH THE EASTERN HALF OF THE AREA. 12Z 
MODEL GUIDANCE GENERALLY AGREEING THE BEST FORCING ALOFT ASSOCIATED 
WITH A PASSING VORT MAX SHOULD REMAIN NORTH AND EAST OF THE AREA...BUT 
MAY PUSH JUST SOUTH ENOUGH TO ASSIST IN PROLONGING ANY PCPN THAT 
DEVELOPED LATE IN THE DAY. BOTH INSTABILITY AND SHEAR ON THE WEAKER 
SIDE BY 00Z TUES...SO LOOKING FOR MORE ISO-SCT SHOWERS WITH A LOW 
END CHC OF A TSTM. BY 06Z...PCPN SHOULD HAVE CLEARED THE AREA WITH 
ANY FORCING AT BOTH THE SFC AND ALOFT NOW EXITING THE AREA. PW 
VALUES WILL ALSO HAVE DROPPED BEHIND THE FRONT...SO ANY FLOODING 
THREAT WITH THE SHOWERS WILL HAVE DIMINISHED. 

UPPER LEVEL TROUGH DIGS SOUTH TUES THROUGH MID WEEK WITH A CLOSED 
LOW HOVERING JUST NORTH OF THE GREAT LAKES. WITH MINIMAL 
PROGRESSIVE MOVEMENT ALOFT...THE COLD FRONT IS EXPECTED TO PUSH 
EAST...BUT THEN STALL OFFSHORE. IT SHOULD PUSH JUST FAR ENOUGH EAST 
TO HAVE MINIMAL IMPACT THROUGH THE COMING WEEK...BUT WILL COME BACK 
INTO THE PICTURE FOR THE COMING WEEKEND. AS THE SURFACE HIGH 
PRESSURE WILL BE BUILDING IN BEHIND THE FRONT AND WILL MAINTAIN HOLD 
OF THE REGION THROUGH THURS. SHORTWAVE ROTATING ON THE SOUTHERN EDGE 
OF THE TROUGH COULD TRIGGER AN ISO SHOWER/TSTM TUES AFTN OVER FAR 
NORTH AND WESTERN EDGES OF THE AREA...BUT WITH A MUCH DRIER AIRMASS 
MOVING IN...COULD VERY WELL END UP BEING A DRY DAY. THE NEXT MENTION 
OF PCPN COMES THURS AFTN WITH A RETURN FLOW SETTING UP OVER THE 
REGION...INJECTING IN A SLIGHTLY MORE MOIST AIRMASS. THE CLOSED LOW 
ALOFT FINALLY PUSHES OFF TO THE NORTHEAST...THOUGH A LONGWAVE TROUGH 
STILL WILL PERSIST OVER THE EASTERN HALF OF THE US FOR THE END OF 
THE WEEK. THE PATTERN STILL BRINGS THROUGH MULTIPLE SHORTWAVES 
THURS-FRI...EACH BRINGING A SLIGHT CHC IN TRIGGERING AN ISO SHOWER 
OR TSTM. 

LOW PRESSURE FORMS ALONG THE STALLED FRONT BY THIS WEEKEND...RIDING 
THE FRONT WHILE SLOWLY APPROACHING THE AREA. GENERAL MODEL CONSENSUS 
BRINGS THE SFC LOW NEAR THE TRI STATE AREA BY SUN MORNING. ENOUGH 
FORCING ALOFT ROUNDING THE BASE OF THE UPPER LEVEL TROUGH SHOULD 
COMBINE WITH THE SFC LOW TO PRODUCE SCT SHOWERS AND TSTMS...ESP FOR 
LATER SAT THROUGH SUN. 

TEMPS REMAIN NEAR STEADY THROUGH THE COMING WEEK...A FEW DEGREES 
BELOW NORMAL.

&&

.AVIATION /01Z MONDAY THROUGH FRIDAY/...
LOW PRESSURE APPROACHES THE AREA TONIGHT AND MOVES THROUGH DURING 
MONDAY...WITH A COLD FRONT CROSSING THE TERMINALS MONDAY 
AFTERNOON.

VFR. THE CHANCE OF SHOWERS AND THUNDERSTORMS INCREASES TOWARD 04Z. 
STORMS BECOME MORE NUMEROUS AND BEST CHANCE WILL BE FROM 05Z SOUTH 
AND WEST TO 09Z TO 12Z NORTH AND EAST. SOME OF THE STRONGER 
THUNDERSTORMS COULD PRODUCE STRONG GUSTY WIND AND SMALL HAIL.

AS THE LOW PASSES THROUGH THE REGION MONDAY THERE WILL BE A CHANCE 
OF SHOWERS...ESPECIALLY ACROSS THE LOWER HUDSON VALLEY INTO 
CONNECTICUT.

SOUTH TO SOUTHWEST WIND 10KT TO 15KT TONIGHT INCREASES MONDAY UP TO 
15KT TO 20KT...WITH GUSTS 25KT TO 30KT. WIND SHIFTS TO THE WEST TO 
NORTHWEST AS THE LOW AND FRONT CROSS THE REGION MONDAY 
AFTERNOON.

.OUTLOOK FOR 00Z TUE THROUGH  FRI...
.MON NIGHT-THU...VFR.
.FRI...VFR. ISO SHRA/TSTM.

&&

.MARINE...
FORECAST ON TRACK WITH MODERATE SOUTHERLY WINDS CONTINUING OVERNIGHT
AHEAD OF LOW PRESSURE AND ASSOCIATED COLD FRONT. MARGINAL SCA WILL
BUILD SLIGHTLY AND REMAIN IN THE 4 TO 7 FT RANGE TONIGHT INTO
MONDAY ON THE OCEAN WATERS.

MARGINAL SCA GUSTS EXPECTED MONDAY AFTERNOON ACROSS ALL NEARSHORE
WATERS IN WAKE OF FRONT.

SEAS ON THE OCEAN ARE EXPECTED TO REMAIN ELEVATED...5-7 FT MON 
NIGHT THROUGH TUES MORNING. AS THE WINDS SHIFT AROUND TO THE 
NW...SEAS WILL BEGIN TO SUBSIDE...WITH SUB-SCA CONDITIONS EXPECTED 
BY TUES AFTN. SUB-SCA CONDITIONS ON ALL WATERS THEN THROUGH THE 
REMAINDER OF THE WEEK...WITH A POSSIBLE RETURN TO 25 KT GUSTS AND 5 
FT SEAS OVER THE WEEKEND DEPENDING ON THE TRACK OF THE LOW.

&&

.HYDROLOGY...
SCATTERED TO NUMEROUS SHOWERS/TSTMS ARE FORECAST TONIGHT INTO
EARLY MONDAY MORNING WITH AN APPROACHING FRONTAL SYSTEM. ANY OF
THESE STORMS HAVE THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS. SOME
UNCERTAINTY STILL EXISTS WITH COVERAGE OF THUNDERSTORMS THOUGH.
MINOR URBAN FLOODING IS POSSIBLE WITH THESE HEAVY DOWNPOURS...BUT
FLASH FLOODING IS NOT EXPECTED SINCE STORMS SHOULD BE MOVING AND
TRAINING IS NOT ANTICIPATED.

SCATTERED CONVECTION IS LIKELY MONDAY AFTERNOON...WITH LOCALIZED
MINOR URBAN FLOOD THREAT. 

NO SIGNIFICANT HYDROLOGIC ISSUES ARE EXPECTED TUES THROUGH THE END 
OF THE WEEK.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...SMALL CRAFT ADVISORY FROM 11 AM TO 6 PM EDT MONDAY FOR ANZ330-
     335-338-340-345.
     SMALL CRAFT ADVISORY UNTIL 6 PM EDT MONDAY FOR ANZ350-353-355.

&&

$$
SYNOPSIS...SEARS/NV
NEAR TERM...SEARS/NV
SHORT TERM...NV
LONG TERM...SEARS
AVIATION...MET
MARINE...SEARS/NV
HYDROLOGY...SEARS/NV






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