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AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
453 PM EDT TUE JUL 29 2014

.SYNOPSIS...
WEAK HIGH PRESSURE SLOWLY BUILDS OFFSHORE THROUGH WEDNESDAY NIGHT.
A FRONTAL BOUNDARY OVER THE WESTERN ATLANTIC ON THURSDAY WILL
GRADUALLY WORK WEST TOWARD THE COAST THROUGH THIS WEEKEND WITH
MULTIPLE WAVES OF LOW PRESSURE TRACKING ALONG IT. WEAK HIGH
PRESSURE WILL THEN RETURN EARLY NEXT WEEK.

&&

.NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
INSTABILITY CLOUDS SHOULD GRADUALLY DISSIPATE...WITH DEVELOPING
INVERSION FROM AROUND 750-650 HPA SERVING AS A LIMITING FACTOR.
GIVEN EXPECTED CLOUD COVER LINGERING INTO THE NIGHT...WEIGHED
TEMPERATURE FORECAST TOWARDS WARMER MET GUIDANCE FOR LOWS. TO
ACHIEVE THIS USED A BLEND OF THE PREVIOUS FORECAST...NAM 2-METER
TEMPERATURES AND A BLEND OF MAV/MET GUIDANCE. LOWS SHOULD BE
AROUND 5 DEGREES BELOW NORMAL.

THERE IS A MODERATE RISK FOR THE METEOROLOGICAL ENHANCEMENT OF
RIP CURRENTS EARLY THIS EVENING AT AREA OCEAN BEACHES.

&&

.SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
THERE IS QUITE A BIT OF SPREAD IN THE MODELS WHETHER THERE WILL
BE SUFFICIENT LOW-MID LEVEL INSTABILITY AND PASSING OF WEAK
700-500 HPA SHORTWAVE WILL PROMOTE SPRINKLES TO MAYBE ISOLD
SHRA/TSTM ACROSS INTERIOR ZONES WEDNESDAY. THE NAM IS THE MOST
BULLISH FOLLOWED BY THE SREF...THE ECMWF IS DRY AND THE CMC REG
AND GFS SUGGEST LIMITING TO WESTERN ORANGE COUNTY. BUFKIT
SOUNDINGS SUGGEST THAT THE THE MID LEVEL CAP THAT DEVELOPS MIGHT
NOT ERODE...EVEN OVER ORANGE COUNTY. THUS...FOR NOW HAVE OPTED
FOR A DRY FORECAST FOR WEDNESDAY FOR ALL BUT THE NW 1/2 OF ORANGE
COUNTY...WHERE HAVE GONE WITH SLIGHT CHANCE POPS.

HOWEVER...WITH WET BULB ZERO HEIGHTS AROUND 7500-8500 FT...AND
500 HPA TEMPERATURES AROUND -15C IT SHOULD NOT TAKE TO MUCH CLOUD
DEPTH TO GET LIGHTNING AND/OR SMALL HAIL/GRAUPEL...SO WENT WITH A
SLIGHT CHANCE OF THUNDER THERE AS WELL. ELSEWHERE ACROSS THE
INTERIOR...WHERE THE CAP IS FORECAST TO BE A BIT STRONGER THAN
OVER NW ORANGE COUNTY...THE QUESTION IS ARE LOW LEVEL LAPSE RATES
STRONG ENOUGH TO PROMOTE SPRINKLES UNDER THE CAP. IF THIS WERE THE
COOL SEASON WOULD BE INCLINED TO SAY YES...BUT NOT CONFIDENT
ENOUGH TO DO SO IN THE WARM SEASON...AS MODELS ON OCCASION OVERDO
THE AMOUNT OF LOW LEVEL INSTABILITY DURING THIS TIME OF YEAR.

ELSEWHERE WOULD EXPECT TO SEE SOME INSTABILITY CLOUDS LIKE
TODAY...SO HAVE LOWERED HIGHS A TAD FROM THE PREVIOUS
FORECAST...CONSISTENT WITH A BLEND OF MAV/MET GUIDANCE WITH NAM
2-METER TEMPERATURES AND MIXING DOWN FROM 875 HPA...EXCEPT 850 HPA
NW ZONES PER BUFKIT SOUNDINGS. HIGHS SHOULD BE A FEW DEGREES BELOW
NORMAL.

WITH WEAK SHORTWAVE EXITING TO THE NE AND MID LEVEL INVERSION
WEAKER THAN TONIGHT...WOULD EXPECT CLOUDS TO DISSIPATE DURING THE
EVENING...SO DO EXPECT SOME RADIATIONAL COOLING WEDNESDAY NIGHT.
BASED ON THIS USED A BLEND OF MAV/MET GUIDANCE WITH NAM 2-METER
TEMPERATURES FOR LOWS...WITH VALUES A FEW DEGREES BELOW NORMAL.

&&

.LONG TERM /THURSDAY THROUGH TUESDAY/...
A HIGHLY AMPLIFIED ANOMALOUS SUMMERTIME PATTERN FEATURES A TROUGH 
ACROSS EASTERN NORTH AMERICA...WITH RIDGING OUT WEST AND ACROSS THE 
WESTERN ATLANTIC. THIS BLOCKING PATTERN WILL RESULT IN THE 
AFOREMENTIONED TROUGH GRADUALLY FILLING AND WORKING EAST AT THE END OF 
THE PERIOD AS AN UPSTREAM KICKER MOVES INTO CENTRAL CANADA. THERE 
ARE CLEARLY TIMING DIFFERENCES AMONGST THE GLOBAL MODEL SUITE WITH 
HOW QUICKLY THIS OCCURS...AS WELL AS WITH AN OFFSHORE FRONTAL 
BOUNDARY THAT RETROGRADES WEST IN RESPONSE TO HEIGHT RISES ALONG THE 
EASTERN SEABOARD THU INTO SAT. THE LATTER OF WHICH COULD BRING A 
BOUT OF STEADY RAINS INTO THE REGION FRI NIGHT INTO THE SAT. THE 12Z 
ECMWF AND 12Z GGEM REMAIN THE MOST AGGRESSIVE SOLUTIONS. THE 
POTENTIAL IS THERE FOE A SIGNIFICANT RAINFALL EVENT...BUT THERE 
REMAINS A DECENT AMOUNT OF UNCERTAINTY WITH THE LOCATION OF THE 
FRONTAL WAVE AND THE BOUNDARY.

FOR THU INTO FRI...HIGH PRESSURE WILL BE SITUATED TO THE EAST WITH A 
RETURN SLY FLOW. AIRMASS REMAINS FAIRLY DRY IN THE LOW-LEVELS WITH 
ONLY MARGINAL INSTABILITY AND WEAK TO MODERATE SHEAR. OVERALL CHANCES 
FOR CONVECTION ARE LOW DURING THIS TIME WITH THE BEST CHANCES BEING 
IN THE AFT/EVE HOURS IN THE HILLS NW OF NYC...DRIVEN BY DIFFERENTIAL 
HEATING. RAIN CHANCES THEN INCREASE WITH THE APPROACH OF THE 
OFFSHORE FRONT AND MULTIPLE WAVES OF LOW PRESSURE. ONCE AGAIN  
THOUGH...THE SOLUTIONS VARY ON THE PROXIMITY OF THE FRONT.

FOR EARLY NEXT WEEK...WEAK HIGH PRESSURE WILL BUILD IN ON THE HEELS 
OF THE DEPARTING UPPER TROUGH. THE GGEM AND GFS BOTH ARE SLOWER WITH 
THE PROGRESSION OF THE TROUGH. THUS...CONVECTION COULD LINGER INTO MON 
WITH A WEAK TROUGH/COLD FRONT MOVING THROUGH.    

TEMPS SHOULD BE NEAR AVG THU-FRI...THEN A LITTLE BELOW AVG THIS 
WEEKEND VIA CLOUD COVER AND GREATER POP...THEN RETURNING TO NEAR AVG 
ON MON. HUMIDITY LEVELS WILL ALSO NE ON THE INCREASE WITH DEW POINTS 
RISING INTO THE 60S.

&&

.AVIATION /21Z TUESDAY THROUGH SUNDAY/...
SURFACE TROUGH REMAINS EAST OF THE CITY TERMINALS.

NW TO W WINDS FOR THE CITY TERMINALS AND POINTS WEST. KISP AND
KBDR MAY EXPERIENCE A COUPLE OF WIND SHIFTS WITH THE SEA BREEZE
BOUNDARY REMAINING NEARBY. SLIGHT CHANCE OF THIS OCCURRING AT JFK
AS WELL.

VRB WINDS 5 KT OR LESS AT ALL TERMINALS FROM 03-05Z THROUGH
WEDNESDAY MORNING. SEA BREEZES QUICKLY DEVELOP LATE WEDNESDAY
MORNING.

..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 FORECASTER COMMENTS: OCCASIONAL GUSTS 16-19KT THRU 00Z. CHANCE
THAT SEA BREEZE PUSHES THROUGH WITH A SSW WIND SHIFT SOMEWHERE IN
THE 00Z-02Z TIME FRAME.

KLGA FORECASTER COMMENTS: OCCASIONAL GUSTS 16-19KT POSSIBLE THRU
00Z TIMING OF WINDS BACKING WNW COULD BE OFF BY AN HOUR OR TWO.
WINDS MIGHT NOT BACK TO AROUND 300 MAGNETIC AND REMAIN AT OR NORTH
OF 310 MAGNETIC THROUGH EARLY EVENING.

KEWR FORECASTER COMMENTS: GUSTS MIGHT BE ONLY OCCASIONAL. WINDS
COULD BE BACKED TO 260-280 MAGNETIC AT TIMES BEFORE 23Z.

KTEB FORECASTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. 

KHPN FORECASTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED. 

KISP FORECASTER COMMENTS: SEA BREEZE COULD RETURN NORTH AND SHIFT
WINDS 240-210 MAGNETIC AS EARLY AS 23Z.

.OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY...
.WEDNESDAY...VFR. ISOLATED SHOWERS/TSTMS POSSIBLE AT KSWF IN THE 
AFTERNOON. 
.THURSDAY-FRIDAY...ISOLATED SHOWERS/TSTMS POSSIBLE IN THE 
AFTERNOON/EARLY EVENING...MAINLY WEST OF A LINE FROM KBDR TO KFRG. 
VFR OUTSIDE OF ANY SHOWERS/TSTMS.
.SATURDAY-SUNDAY...MAINLY VFR...SUB-VFR CONDITIONS POSSIBLE IN SCT 
SHOWERS.

&&

.MARINE...
WINDS WILL BE 10 KT OR LESS ON THE WATERS AROUND LONG ISLAND
THROUGH WEDNESDAY NIGHT. SEAS ON THE COASTAL OCEAN WATERS WILL BE
4 FT OR LESS AND ON THE REMAINDER OF THE WATERS 1 FT OR LESS AS A
RESULT THROUGH WEDNESDAY NIGHT.

CONDITIONS SHOULD REMAIN QUIET FROM THURSDAY THOUGH EARLY NEXT
WEEK WITH AN APPROACHING OFFSHORE FRONT THIS WEEKEND AND THEN WEAK
HIGH PRESSURE EARLY NEXT WEEK.

&&

.HYDROLOGY...
IT SHOULD BE MAINLY DRY THROUGH WEDNESDAY NIGHT. 

NO SIGNIFICANT RAINFALL IS THEN EXPECTED FROM THURSDAY THROUGH
FRIDAY.

PARTS OF THE AREA...ESPECIALLY CLOSER TO THE COAST...HAVE THE 
POTENTIAL FOR HEAVY RAIN FRIDAY NIGHT AND THIS
WEEKEND...DEPENDING ON THE POSITION OF AN OFFSHORE FRONTAL ZONE
AND TIMING OF ANY ASSOCIATED WEAK WAVES OF LOW PRESSURE. THIS
POTENTIAL IS STILL SEVERAL DAYS AWAY...SO IT IS TOO EARLY TO OFFER
SPECIFIC FORECAST DETAILS OR TO MENTION IN HWO.

&&

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

&&

$$
SYNOPSIS...MALOIT/DW
NEAR TERM...MALOIT
SHORT TERM...MALOIT
LONG TERM...DW
AVIATION...JC/MPS
MARINE...MALOIT/DW
HYDROLOGY...MALOIT/DW

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