Scientific Forecaster Discussion

Return to Local Conditions & Forecast

Without Abbreviations
With Abbreviations

AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE NEW YORK NY
808 PM EDT FRI JUL 3 2015

.SYNOPSIS...
HIGH PRESSURE RETREATS TO THE NORTHEAST INTO SATURDAY...AS LOW
PRESSURE TRACKS INTO THE MID ATLANTIC STATES TONIGHT...THEN
SOUTH...THEN SOUTHEAST OF LONG ISLAND SATURDAY. WEAK HIGH PRESSURE
BUILDS IN FROM THE WEST SATURDAY NIGHT...THEN BUILDS ACROSS FROM
SUNDAY INTO MONDAY. A WEAK LOW AND ASSOCIATED WARM FRONT WILL THEN
LIFT SLOWLY UP THE COAST MONDAY NIGHT INTO TUESDAY NIGHT. A SLOW
MOVING COLD FRONT APPROACHES ON WEDNESDAY AND POSSIBLY LINGERS
INTO THURSDAY WITH A WAVE OF LOW PRESSURE FORMING ALONG IT. HIGH
PRESSURE THEN RETURNS FOR FRIDAY.

&&

.NEAR TERM /UNTIL 6 AM SATURDAY MORNING/...
BASED ON LATEST SAT IMAGERY AND SFC OBS...HIGH LEVEL CLOUDS MOVING
IN FROM THE SW ARE SUFFICIENTLY OPAQUE TO INCREASE CLOUD COVER
THIS EVENING. OTHERWISE..OTHER FORECAST PARAMETERS ARE ON TRACK. 

SHORTWAVE RIDGING CROSSES THE AREA THIS EVENING...THEN EXITS TO
THE NE OVERNIGHT. CLOUDS WILL GRADUALLY THICKEN AND LOWER THROUGH
THE NIGHT. 

COULD SEE SOME LIGHT OVERRUNNING RAINS MAKE IT INTO FAR W/SW
ZONES LATE TONIGHT...ADDRESS WITH SLIGHT CHANCE TO LOW END CHANCE
POPS.

FOR LOWS TONIGHT USED A BLEND OF MAV/MET/ECS GUIDANCE. LOWS
SHOULD BE A FEW DEGREES BELOW NORMAL. 

&&

.SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
GFS APPEARS TO BE SUFFERING FROM CONVECTIVE FEEDBACK ISSUES AND
HAS BEEN DISCARDED IN THE SHORT TERM.

NON-GFS CONSENSUS SOLUTION TRACKS A LOW S OF LONG ISLAND SATURDAY
MORNING...AND JUST S THEN E OF THE 40N/70W BENCHMARK SATURDAY
AFTERNOON. GIVEN NOW FARTHER S AND FASTER TRACK OF LOW...AND THAT
THE NAM AND CMC KEEP THE AREA DRY...HAVE LOWERED POPS TO CHANCE
THROUGHOUT THE AREA. CANNOT RULE OUT DRY NAM AND CMC SOLUTION
COMPLETELY EITHER. HAVE HIGHEST POPS OVER S ZONES CLOSEST TO LOW
AND LOWEST POPS OVER N ZONES. RAIN WILL MAINLY BE IN THE MORNING
AS THE COASTAL LOW GOES BY...THEN A CHANCE OF SHOWERS IN THE
AFTERNOON WITH THE PASSING OF THE 700 HPA TROUGH AXIS...AND A 500
HPA SHORTWAVE. BEST CHANCE OF SHOWERS IN THE AFTERNOON IS OVER W
ZONES.

FOR NOW...DO HAVE LINGERING CHANCE POPS EARLY SAT EVENING OVER FAR
E ZONES...BUT GENERALLY EXPECT SATURDAY NIGHT TO BE DRY WITH
RIDGING BUILDING IN AT 700 HPA SERVING TO COUNTER 500 HPA TROUGH
AXIS CROSSING AREA.

FOR HIGHS SATURDAY USED A BLEND OF MAV/MET/ECS GUIDANCE AND NAM
2-METER TEMPERATURES...WITH VALUES FORECAST TO BE 5-10 DEGREES
BELOW NORMAL. HOWEVER...IF THE NAM AND CMC ARE CORRECT AND THINGS
REMAIN DRY...THEN HIGHS COULD BE AROUND 5 DEGREES WARMER THAN THE
CURRENT FORECAST.

A BLEND OF MAV/ECS/MET GUIDANCE AND NAM 2-METER TEMPERATURES WAS
USED FOR LOWS SATURDAY NIGHT...WITH READINGS EXPECTED TO BE AROUND
5 DEGREES BELOW NORMAL.

THERE IS A MODERATE RISK OF RIP CURRENTS ON SATURDAY.

&&

.LONG TERM /SUNDAY THROUGH FRIDAY/...
UPPER TROUGH OVER THE EASTERN ZONES SUNDAY MORNING SHIFTS EAST WITH 
DEEP-LAYERED RIDGING FOLLOWING THROUGH THE DAY. EXPECTING A MOSTLY 
SUNNY DAY FROM THIS. PREFERRED THE WARMER NAM MOS FOR HIGHS BASED ON 
FORECAST 850MB TEMPS...AND EVEN MADE SOME SLIGHT UPWARD
ADJUSTMENTS OVER LONG ISLAND SINCE THERE WILL PROBABLY BE PLENTY
OF TIME TO WARM UP BEFORE ANY SEA BREEZE EFFECTS KICK IN...AND
WATER TEMPS ARE CURRENTLY UP TO AROUND 70.

LOOKS LIKE WE WILL HAVE ANOTHER DRY DAY FOR MONDAY WITH A GOOD
DEAL OF SUNSHINE. FOR HIGHS...HAVE GONE ABOVE AVAILABLE MOS
GUIDANCE...NOTING RISING HEIGHTS AND 850MB TEMPERATURES. THIS
COULD BE OFFSET SLIGHTLY BY SUBSIDENCE...AND FOR COASTAL AREAS...A
WEAK ONSHORE FLOW ALL DAY AS WELL. LOOKS LIKE HIGHS GENERALLY WILL
BE THE SAME OR SLIGHTLY BELOW SUNDAYS FOR COASTAL AREAS...AND A
LITTLE ABOVE SUNDAYS INLAND.

MODELS ARE THEN IN SOMEWHAT BETTER AGREEMENT WITH THE TIMING OF TWO 
SURFACE FEATURES THAT COULD BRING SHOWERS ACROSS THE AREA FOR THE 
MID-WEEK PERIOD. THE FIRST IS A WEAKENING AREA OF LOW PRESSURE OR 
LOW PRESSURE TROUGH SHIFTING IN FROM THE SW. THE SECOND IS A 
WEAKENING COLD FRONT MOVING IN FROM THE NW. WILL CAP POPS AT CHANCE 
LATE MON NIGHT-WEDS NIGHT...BUT THE BEST OVERALL CHANCE OF RAINFALL 
AT THIS POINT APPEARS TO BE WEDS AFTERNOON/WEDS EVENING WITH THE 
PASSAGE OF THE COLD FRONT. ENOUGH CAPE IS FORECAST FOR A CHANCE
OF THUNDER THROUGH THE PERIOD. HIGH TEMPS FOR TUESDAY AND WEDS ARE
SOMEWHAT TRICKY DUE TO THE UNCERTAINTY OF CLOUD COVERAGE. MORE
SUNSHINE ON TUESDAY COULD PUSH TEMPS A COUPLE OF DEGREES HIGHER
THAN CURRENTLY FORECAST. WEDNESDAY WILL PROBABLY BE THE COOLER OF
THE TWO DAYS WITH A BETTER CHANCE OF HIGHER CLOUD COVER.

MODELS DIVERGE AFTER THIS POINT...WITH ECMWF AND CMC DEVELOPING A 
WAVE OF LOW PRESSURE TO OUR SW ALONG THE STALLING COLD FRONT AND 
EVENTUALLY BRINGING A CHANCE OF RAIN THURSDAY/THURSDAY NIGHT. GFS
KEEPS US DRY WITH A LACK OF LOW DEVELOPMENT. WILL THEREFORE JUST
GO WITH CHANCE POPS FOR THIS PERIOD...THEN KEEP FRIDAY DRY AS
HIGH PRESSURE BUILDS BACK IN.

&&

.AVIATION /00Z SATURDAY THROUGH WEDNESDAY/...
HIGH PRESSURE REMAINS OFF THE NORTHEAST COAST TONIGHT AS A WAVE OF 
LOW PRESSURE MOVES INTO THE MID ATLANTIC STATES. THE LOW TRACKS 
SOUTH OF LONG ISLAND SATURDAY AND OFF THE NORTHEAST COAST BY 
SATURDAY NIGHT. THERE IS STILL SOME UNCERTAINTY AS TO THE TRACK OF 
THE LOW. A FARTHER NORTH TRACK WILL BRING THE POTENTIAL FOR MVFR 
CEILINGS AND MORE WIDESPREAD RAIN DURING THE DAY SATURDAY. A FARTHER 
TRACK TO THE SOUTH HAS THE POTENTIAL FOR THE TERMINALS TO BE DRY 
THROUGH THE DAY. FOR NOW WILL KEEP THE PROB 30 GROUP WITH VFR 
CONDITIONS IN LIGHT RAIN DURING THE DAY. OTHERWISE VFR.

SEA BREEZES END 00Z TO 02Z WITH WIND LIGHT AND VARIABLE UNTIL TOWARD 
MORNING. A LIGHT NORTHEAST TO EAST FLOW DEVELOPS...BECOMING MORE 
NORTHERLY DURING THE DAY AS THE LOW TRACKS TO THE SOUTH. WIND 
FORECAST WILL ALSO DEPEND ON THE TRACK OF THE LOW. HOWEVER...WIND IS 
EXPECTED TO BE 10 KT OR LESS. A FEW GUSTS UP TO 15 KT ARE POSSIBLE 
DURING THE AFTERNOON AT THE NYC AREA TERMINALS.

GENERALLY LOW TO MODERATE FORECAST CONFIDENCE WITH UNCERTAINTY ON 
TRACK OF THE LOW.

   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: NO UNSCHEDULED AMENDMENTS EXPECTED TONIGHT. 
AMENDMENTS POSSIBLE FOR THE POTENTIAL OF MVFR CONDITIONS IN LIGHT 
RAIN.

KLGA FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED TONIGHT. 
AMENDMENTS POSSIBLE FOR THE POTENTIAL OF MVFR CONDITIONS IN LIGHT 
RAIN. 

KEWR FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED TONIGHT. 
AMENDMENTS POSSIBLE FOR THE POTENTIAL OF MVFR CONDITIONS IN LIGHT 
RAIN.  

KTEB FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED TONIGHT. 
AMENDMENTS POSSIBLE FOR THE POTENTIAL OF MVFR CONDITIONS IN LIGHT 
RAIN.

KHPN FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED TONIGHT. 
AMENDMENTS POSSIBLE FOR THE POTENTIAL OF MVFR CONDITIONS IN LIGHT 
RAIN. 

KISP FCSTER COMMENTS: NO UNSCHEDULED AMENDMENTS EXPECTED TONIGHT. 
AMENDMENTS POSSIBLE FOR THE POTENTIAL OF MVFR CONDITIONS IN LIGHT 
RAIN. 

.OUTLOOK FOR 00Z SUNDAY THROUGH WEDNESDAY...
.SATURDAY NIGHT-MONDAY NIGHT...VFR.
.TUESDAY-WEDNESDAY...CHANCE OF MVFR IN SHOWERS AND THUNDERSTORMS.

&&

.MARINE...
A RELAXED PRESSURE GRADIENT OVER THE WATERS WILL KEEP WINDS 10 KT
OR LESS THROUGH SATURDAY MORNING. THE GRADIENT INCREASES SATURDAY
AFTERNOON AND NIGHT...WITH GUSTS TO 25 KT POSSIBLE ON THE COASTAL
OCEAN WATERS...AND GUSTS TO 15-20 KT ON THE NON-OCEAN ZONES. SEAS
COULD ALSO BUILD TO UP TO 5 FT ON THE COASTAL OCEAN WATERS
SATURDAY AFTERNOON AND NIGHT. 

FOR NOW CONFIDENCE IN SCA CONDITIONS IS BELOW THE REQUIRED 80
PERCENT NEEDED TO ISSUE A SMALL CRAFT ADVISORY. THERE IS STILL TO
MUCH UNCERTAINTY ON THE TRACK...STRENGTH AND TIMING OF A COASTAL
LOW FORECAST TO PASS TO THE S THEN E OF LONG ISLAND SATURDAY AND
SATURDAY NIGHT.

WINDS AND SEAS LIKELY REMAIN BELOW SCA LEVELS THROUGH THE LONG
TERM PERIOD AS A WEAK PRESSURE GRADIENT REMAINS IN
PLACE...RESULTING IN LIGHT WINDS.

&&

.HYDROLOGY...
GENERALLY 1/10 TO 1/4 OF AN INCH OF QPF IS POSSIBLE LATE TONIGHT
AND SATURDAY. THERE IS SOME POTENTIAL THE AREA COULD REMAIN DRY IN
THIS TIME FRAME...THERE IS ALSO AN EVEN SMALLER CHANCE THE AREA
COULD RECEIVE AROUND DOUBLE THIS AMOUNT OF RAINFALL IN THIS TIME
FRAME.

IT SHOULD BE MAINLY DRY FROM SATURDAY NIGHT THROUGH AT LEAST
MONDAY.

SIGNIFICANT PRECIPITATION COULD OCCUR AT SOME POINT DURING THE 
MIDDLE OF NEXT WEEK AS A WEAK LOW AND WARM FRONT MOVE UP THE COAST 
ON TUE...THEN WITH A COLD FRONT APPROACHING AND STALLING NEARBY WED 
INTO THU. PREDICTABILITY IS TOO LOW TO OFFER ANY SPECIFICS AT THIS 
TIME.

&&

.TIDES/COASTAL FLOODING...
WITH A RECENT FULL MOON...TIDAL DEPARTURES OF ONLY 3/4 TO 1 1/2
FT ARE NEEDED FOR MINOR COASTAL FLOODING BENCHMARKS TO BE REACHED
AT THE PEAK OF THE NIGHTTIME HIGH TIDES THE NEXT COUPLE OF DAYS.
MINOR BENCHMARKS COULD BRIEFLY BE TOUCHED ALONG THE SOUTH SHORE
BAYS OF NASSAU COUNTY TONIGHT AND POSSIBLY SATURDAY NIGHT. IN
ADDITION...WINDS INCREASE DURING THE DAY SATURDAY FROM THE
NORTHEAST...SO THE DAYTIME HIGH TIDES MAY NEED TO BE MONITORED AS
WELL.

&&

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

&&

$$

SYNOPSIS...JC/MALOIT
NEAR TERM...MALOIT/DW
SHORT TERM...MALOIT
LONG TERM...JC
AVIATION...MET
MARINE...JC/MALOIT/DW
HYDROLOGY...JC/MALOIT
TIDES/COASTAL FLOODING...

National Weather Service Glossary of Abbreviations