Area Forecast Discussion
Issued by NWS Upton, NY

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000
FXUS61 KOKX 260813
AFDOKX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
413 AM EDT SUN JUL 26 2015

.SYNOPSIS...
HIGH PRESSURE MOVES NORTHEAST TONIGHT AS A WARM FRONT SLOWLY
APPROACHES FROM THE SOUTHWEST. THE WARM FRONT LIFTS NORTHWARD
ACROSS THE REGION ON SUNDAY. ANOTHER WEAKENING COLD FRONT THEN
MOVES INTO THE AREA LATE SUNDAY AND MONDAY. HIGH PRESSURE BUILDS
IN THROUGH THE MIDDLE OF THE WEEK. A COLD FRONT APPROACHES
THURSDAY...THEN PASSES JUST EAST FRIDAY AND SATURDAY.

&&

.NEAR TERM /UNTIL 6 PM THIS EVENING/...
MODELS NOT AS BULLISH ON CHANCES FOR PRECIPITATION TODAY AS THEY
HAVE BEEN PREVIOUSLY. IT NOW APPEARS THERE WILL NOT BE ANY
SHORTWAVE TROUGH CROSSING IN THE REGION...AND POSSIBLY COULD
ACTUALLY HAVE A WEAK SHORTWAVE RIDGE CROSS THE AREA. THE UPPER JET
IS ALSO A BIT WEAKER THAN FORECAST...MAYBE AROUND 60 KT AT 250
HPA...AND IT APPEARS WILL BE IN LEFT FRONT QUADRANT ALL DAY.


CAPE IS FORECAST TO BE 1000-2000 J/KG OVER ALL BUT LONG
ISLAND...WHERE COULD SEE LESS THAN 100 DUE TO MARINE INFLUENCE.
LONG ISLAND IS ALSO THE ONLY AREA THAT REALLY WILL BE IMPACTED BY
A 20-25 KT LOW LEVEL JET AS WELL. BULK SHEAR IS FORECAST TO BE A
TAD WEAKER THAN IT WAS YESTERDAY...SO NOW LOOKING AT BULK
RICHARDSON NUMBERS GENERALLY 40-80 WITH MAYBE SOME BOWING SEGMENTS
POSSIBLE...BUT MAINLY PULSE TYPE STORMS ARE NOW EXPECTED...IF ANY
THING FORMS AT ALL. SO...POTENTIAL FOR ANY STRONG TO POSSIBLY
SEVERE STORMS IS LOWER THAN PREVIOUSLY FORECAST...BUT STILL NOT
QUITE ZERO.

BASED ON THE ABOVE...HAVE LOWERED POPS TODAY TO SLIGHT CHANCE OVER
MOST OF LONG ISLAND AND COASTAL SE CT...AND TO MAINLY LOW END
CHANCE ELSEWHERE...THOUGH DO HAVE POPS OF 35-40 OVER NW
ZONES...CLOSEST TO WHATEVER LIMITED FORCING THE AREA DOES
EXPERIENCE. GENERALLY EXPECT MOST AREAS TO REMAIN DRY...AND THOSE
THAT DO EXPERIENCE ANY RAINFALL IT SHOULD NOT LAST VERY LONG. MUCH
MORE LIKELY FOR ANY CONVECTION TODAY TO MISS RATHER THAN HIT
ANY GIVEN LOCATION IN THE CWA.

FOR HIGHS TODAY...USED A BLEND OF MIXING DOWN FROM 950 TO 850 HPA
PER BUFKIT SOUNDINGS...WITH A MIXTURE OF MET/ECS/MAV GUIDANCE AND
NAM 2-METER TEMPERATURES. HIGHS SHOULD BE A FEW DEGREES ABOVE
ZERO...AND COULD REACH THE 90 DEGREE MARK IN URBAN PORTIONS OF NE
NJ.

THERE IS A HIGH RISK FOR THE METEOROLOGICAL ENHANCEMENT OF RIP
CURRENT FORMATION AT ATLANTIC BEACHES TODAY.

&&

.SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
HAVE CHANCE POPS CWA BY LATE TONIGHT IN RESPONSE TO A 700-500 HPA
SHORTWAVE CROSSING THE AREA. WITH SHOWALTER INDICES FORECAST TO BE
GENERALLY AT OR BELOW 0...HAVE THUNDER IN AS WELL. A BLEND OF
MAV/MET/ECS GUIDANCE AND NAM 2-METER TEMPERATURES WAS USED FOR
LOWS TONIGHT...WITH VALUES FORECAST TO BE AROUND 5 DEGREES ABOVE
NORMAL.

ANOTHER WEAK 700-500 HPA SHORTWAVE PUSHES THROUGH THE AREA
MONDAY...MAINLY IN THE MORNING. SO START WITH CHANCE POPS
THROUGHOUT...THEN TAPER OFF FROM SE TO NW KEEPING POPS HIGHEST IN
THE VICINITY OF A WEAK SURFACE BOUNDARY. CAPE IS STILL FORECAST TO
BE AROUND 1500-2500 J/KG MONDAY...WITH GENERALLY AROUND 20 KT OF
BULK SHEAR. SO WITH BULK RICHARDSON NUMBERS MAINLY FROM 50-100
OVER THE AREA...EXPECT MAINLY PULSE TYPE STORMS...IF ANY DO OCCUR.
ONCE AGAIN...WILL BE MUCH MORE MISS THAN HIT FOR ANY GIVEN AREA
WITH THE CONVECTION. FOR HIGHS MONDAY USED A BLEND OF MAV/ECS/MET
GUIDANCE WITH NAM 2-METER TEMPERATURES AND A MIX DOWN FROM 950-850
HPA PER BUFKIT SOUNDINGS. HIGHS SHOULD BE NEAR NORMAL FOR THIS
TIME OF YEAR.

HAVE SLIGHT CHANCE POPS MONDAY NIGHT AS A LINGERING SURFACE
BOUNDARY WORKS ON DISSIPATING OVER THE AREA...THEN CARRY INTO
TUESDAY OVER SE CT/FAR E LONG ISLAND AS THERE ARE SOME SIGNS THE
BOUNDARY COULD LINGER INTO TUESDAY THERE BEFORE FINALLY DYING OFF.
OTHERWISE...DEEP LAYERED RIDGING BEGINS TO BUILD IN MONDAY NIGHT
AND TUESDAY...WITH DECREASING CLOUD COVER MONDAY NIGHT...AND
MINIMAL CLOUD COVER ON TUESDAY...EXCEPT FOR MAYBE OVER SE CT/FAR E
LONG ISLAND DEPENDING ON EXACTLY HOW LONG THE AFOREMENTIONED
DECAYING SURFACE BOUNDARY LINGERS AROUND.

LOWS MONDAY NIGHT WERE BASED ON A BLEND OF ECS/MET/MAV GUIDANCE
AND NAM 2-METER TEMPERATURES WITH VALUES FORECAST TO BE AROUND 5
DEGREES ABOVE NORMAL. ON TUESDAY A MIXTURE OF MIXING DOWN FROM 950
TO 775 HPA PER BUFKIT SOUNDING...NAM 2-METER TEMPERATURES AND A
BLEND OF MET/MAV GUIDANCE WAS USED FOR HIGHS...WITH READINGS
EXPECTED TO BE 5-10 DEGREES ABOVE NORMAL. URBAN AREAS SHOULD SEE
INTO THE LOWER 90S. HEAT INDICES IN URBAN AREAS SHOULD REACH THE
LOWER TO POSSIBLY MIDDLE 90S ON TUESDAY.

DEEP LAYERED RIDGING CONTINUES TO BUILD IN TUESDAY NIGHT...WITH
SUBSIDENCE UNDER THE RIDGE KEEPING THINGS DRY WITH MINIMAL IF ANY
CLOUD COVER. LOWS WERE BASED ON A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC
GUIDANCE WITH NAM 2-METER TEMPERATURES AND SHOULD BE 5-10 DEGREES
ABOVE NORMAL.

&&

.LONG TERM /WEDNESDAY THROUGH SATURDAY/...
THE DEEP LAYERED RIDGE AXIS CONTINUES TO BUILD OVER THE AREA INTO
WEDNESDAY EVENING...THEN SLOWLY SLIDE TO THE EAST INTO THURSDAY.
THIS SHOULD KEEP THINGS DRY WEDNESDAY-THURSDAY MORNING.

AN APPROACHING 850-500 HPA TROUGH THURSDAY AFTERNOON WARRANTS A
CHANCE OF SHOWERS AND THUNDERSTORMS THEN OVER THE NW 2/3 OF THE
CWA AND A SLIGHT CHANCE ELSEWHERE. WITH CURRENTLY ONLY 500-1500
J/KG OF CAPE FORECAST OVER THE AREA AND 20 KT OR LESS OF
SHEAR...THERE POTENTIAL FOR STRONG TO POSSIBLY SEVERE STORMS
APPEARS RELATIVELY LOW AT THIS TIME. THE LIMITING FACTOR IS A
FORECAST OF ELEVATED WARMING AROUND 700-600 HPA. IF THIS CAN BE
OVERCOME...THEN THE POSSIBILITY OF STRONG TO SEVERE STORMS WOULD
INCREASE.

THE AFOREMENTIONED TROUGH PASSES TO THE EAST BY FRIDAY
MORNING...SO ONLY HAVE CHANCE POPS THURSDAY EVENING...THEN
TAPERING OFF FROM NW TO SE LATE THURSDAY NIGHT.

WNW-WSW FLOW SETS UP ALOFT FRIDAY-SATURDAY. FOR NOW GOING WITH A
DRY FORECAST IN THIS TIME FRAME AS ANY TROUGHING IS FORECAST TO
FLATTEN OUT IN BOTH THE GFS AND ECMWF IS IT MOVES TOWARDS THE EAST
COAST...IN RESPONSE TO THE SUB-TROPICAL RIDGE RETROGRADING
TOWARDS THE EAST COAST.

FOR TEMPERATURES WEDNESDAY-SATURDAY A BLEND OF
MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE WAS USED. EXPECT TEMPERATURES TO
GENERALLY BE ABOVE NORMAL IN THIS TIME FRAME...WITH TEMPERATURES
WEDNESDAY AND THURSDAY APPROACHING 10 DEGREES ABOVE NORMAL IN
PLACES. GIVEN THE HEAT AND HUMIDITY EXPECTED ON WEDNESDAY AND
THURSDAY...THERE IS THE POTENTIAL FOR HEAT INDICES TO REACH THE
MID TO UPPER 90S EACH DAY IN NYC/URBAN NE NJ.

&&

.AVIATION /07Z SUNDAY THROUGH THURSDAY/...
A WEAK COLD FRONT APPROACHES LATE TODAY AND WEAKENS ACROSS THE
AREA TONIGHT. WEAK HIGH PRESSURE BUILDS INTO THE REGION MONDAY.

ISOLATED SHRA/TSRA POSSIBLE ACROSS NORTHERN TERMINALS EARLY THIS
MORNING AS A WARM FRONT PASSES THROUGH THE REGION.

OTHERWISE...VFR. SCT SHRA/TSRA DEVELOPMENT LIKELY N&W OF NYC
TERMINALS LATE THIS AFT/EARLY EVE AS A WEAK COLD FRONT APPROACHES
FROM THE WEST. BEST CHANCE OF CONVECTION THIS AFTERNOON WILL BE
AT KSWF. WILL CONTINUE PROB30 GROUP FOR KEWR/KTEB/KHPN/KSWF. MVFR
AND POSSIBLY LOWER CONDITIONS IN ANY SHRA/TSRA THAT DEVELOPS.
WEAKENING SCT SHRA/ISO TSRA ACTIVITY SHOULD TRANSLATE EAST ACROSS
REMAINING TERMINALS LATER THIS EVENING INTO TONIGHT.

SW WINDS 5-10 KT DEVELOP THIS MORNING. STRONG AFTERNOON
SEABREEZES WILL RESULT IN S WINDS 15-20 KT AT COASTAL TERMINALS.
LOW PROB OF SE SEABREEZE MOVING INTO KEWR/KTEB...LIKELY REMAINING
JUST EAST OF TERMINALS.

.OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY...
.LATE TONIGHT-MONDAY...MAINLY VFR OUTSIDE OF ISO-SCT SHRA/TSRA.
PATCHY FOG IS POSSIBLE LATE TONIGHT/EARLY MORNING ACROSS OUTLYING
TERMINALS.
.TUESDAY-THURSDAY...MAINLY VFR. 5-6SM HAZE DEVELOPMENT POSSIBLE.
SW WINDS WITH AFTERNOON SEABREEZE DEVELOPMENT AT COASTAL
TERMINALS.

&&

.MARINE...
WIND AND SEAS ARE EXPECTED TO REMAIN BELOW SMALL CRAFT LEVELS
THROUGH TONIGHT. MARGINAL SCA GUSTS POSSIBLE ACROSS WESTERN OCEAN
WATERS AND SURROUNDING NEARSHORE WATERS LATE THIS AFTERNOON/EVE WITH
COASTAL JET. OCEAN SEAS LIKELY BUILD TO AROUND 4 FT BY THIS EVENING.

SUB SCA CONDITIONS WITH A FAIRLY WEAK PRESSURE GRADIENT MONDAY
THROUGH WEDNESDAY AS HIGH PRESSURE BUILDS OVER THE REGION.

MARGINAL SCA WIND GUSTS POSSIBLE THU AFT ACROSS WESTERN OCEAN AND
NEARSHORE WATERS AHEAD OF A COLD FRONT. PERSISTENT S/SW FLOW
BUILDING ACCOMPANYING SWELLS AND STRONGER WINDS ON THU COULD RESULT
IN SEAS BUILDING TO 5 FT. HOWEVER...WAVEWATCH HAS A TENDENCY TO
OVERDO SEAS IN SOUTHERLY FLOW...THIS WILL NEED TO BE MONITORED AS
THE WEEK PROGRESSES.

&&

.HYDROLOGY...
NO WIDESPREAD SIGNIFICANT PRECIPITATION IS EXPECTED INTO THE
MIDDLE OF THE WEEK.

HOWEVER...ANY STRONGER STORMS THAT DUE HAPPEN TO FORM ON MONDAY
WILL BE VERY SLOW TO MOVE...WITH STORM MOTION FORECAST TO BE 5 KT
OR LESS. AS A RESULT...THERE IS THE POTENTIAL FOR LOCALIZED URBAN/POOR
DRAINAGE FLOODING FROM MONDAY INTO MONDAY EVENING.

THERE IS ALSO THE POSSIBILITY FOR LOCALLY HEAVY RAINFALL WITH ANY
STRONGER STORMS THURSDAY AFTERNOON/EVENING...WHICH COULD ALSO
POSSIBLY CAUSE LOCAL URBAN/POOR DRAINAGE FLOODING.

&&

.OKX WATCHES/WARNINGS/ADVISORIES...
CT...NONE.
NY...HIGH RIP CURRENT RISK THROUGH THIS EVENING FOR NYZ075-080-081-
     178-179.
NJ...NONE.
MARINE...NONE.

&&

$$

SYNOPSIS...MALOIT
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...MALOIT
AVIATION...NV
MARINE...NV
HYDROLOGY...MALOIT



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