187
FXUS61 KOKX 311943
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
343 PM EDT FRI JUL 31 2026
WHAT HAS CHANGED
INCREASED POPS THROUGH EARLY THIS EVENING AND FOR SATURDAY ALSO.
EMPHASIZED THE HEAVY RAIN IN THE FORECAST MONDAY THROUGH MONDAY
NIGHT.
KEY MESSAGES
1) POP-UP SHOWER AND THUNDERSTORM POTENTIAL THROUGH EARLY
EVENING. MAINLY DRY TONIGHT BUT RELATIVELY WARMER THAN PREVIOUS
NIGHT.
2) AIRMASS BECOMES WARMER AND MORE HUMID SATURDAY WITH LOW
TEMPERATURES AT NIGHT TRENDING HIGHER SATURDAY NIGHT COMPARED TO
THE PREVIOUS NIGHT. MAINLY DRY CONDITIONS EXPECTED.
3) MORE RAIN POTENTIAL NEXT WEEK WITH A HEAVY RAIN THREAT MONDAY
INTO MONDAY NIGHT.
DISCUSSION
KEY MESSAGE 1
WITH A DEEP COLD POOL WITHIN AN EXITING TROUGH, THERE IS ENOUGH
FORCING COMBINED WITH SOME LOW LEVEL INSTABILITY TO GENERATE A
FEW SHOWERS AND THUNDERSTORMS. THIS IS IN ACCORDANCE WITH THE
REFLECTIVITY FORECASTS FOR CAMS FOR THE LOCAL AREA THROUGH EARLY
THIS EVENING.
THE SURFACE HIGH PRESSURE ACROSS THE AREA IS WEAK IN MAGNITUDE
AND WITHOUT SUFFICIENT SUBSIDENCE, WE ARE SEEING SOME CONVECTIVE
ACTIVITY AS A RESULT.
THEREAFTER WITH DIURNAL COOLING FOR TONIGHT, INSTABILITY WILL
DIMINISH AND WITH EVEN LESS VERTICAL FORCING, ANY REMAINING
SHOWERS OR THUNDERSTORMS WILL QUICKLY DISSIPATE. THE WIND FLOW
WILL REMAIN LIGHT AND ONSHORE NEAR THE COAST. MIN TEMPERATURES
TREND A LITTLE WARMER THAN THE PREVIOUS NIGHT. ALSO, THERE WILL
ONCE AGAIN BE SOME POTENTIAL FOR PATCHY FOG OUTSIDE OF NYC,
ESPECIALLY IN THE VALLEYS AND RURAL AREAS WHICH WILL COOL OFF
MORE.
KEY MESSAGE 2
WEAK HIGH PRESSURE SHIFTS OFFSHORE INTO THE WESTERN ATLANTIC THE
FIRST HALF OF THIS WEEKEND, EVENTUALLY GIVING WAY TO AN
APPROACHING LOW PRESSURE SYSTEM. ALOFT, A DEEPENING TROUGH WILL
APPROACH FROM THE WEST ALONG WITH THE DEVELOPING LOW PRESSURE
SYSTEM AT THE SURFACE.
MORE SOUTHERLY FLOW SATURDAY WILL LEAD TO A WARMER AND MORE
HUMID AIRMASS. TEMPERATURES WILL TREND WARMER FOR LOWS SATURDAY
NIGHT COMPARED TO THE PREVIOUS NIGHT.
MAINLY DRY CONDITIONS ARE EXPECTED BUT THERE COULD BE AN
ISOLATED SHOWER OR THUNDERSTORM SATURDAY INTO EARLY SATURDAY
EVENING WITH DAYTIME INSTABILITY AND RELATIVELY COLDER AIR ALOFT
MOVING IN FROM THE WEST WITH AN APPROACHING TROUGH. THE POSSIBLE
SHOWER OR THUNDERSTORM WOULD BE MAINLY TO THE NORTH AND WEST OF
NYC.
KEY MESSAGE 3
THE APPROACHING LOW PRESSURE SYSTEM AT THE SURFACE AND DEEPENING
TROUGH APPROACHING IN THE UPPER LEVELS WILL MAKE FOR A MORE
TROPICAL AIRMASS WITH THE INCREASE IN DEPTH OF SOUTHERLY FLOW
SUNDAY THROUGH MONDAY NIGHT.
THE CHANCES OF RAIN START TO INCREASE MORE SUBSTANTIALLY LATE
SUNDAY NIGHT INTO MONDAY. THE HEAVIEST OF THE RAIN FROM THE
FORECAST MODEL GUIDANCE LOOKS TO OCCUR MONDAY INTO MONDAY NIGHT.
PWATS INDICATED IN THE FORECAST MODELS REACH UP TO 2.2 TO 2.4
INCHES. THERE IS ALSO A POSSIBILITY OF THUNDERSTORMS AS WELL,
WHICH WOULD EASILY RESULT IN TORRENTIAL DOWNPOURS. THE PARALLEL
FLOW FROM LOWER TO UPPER LEVELS INCREASES THE TRAINING OF
CONVECTION, WHERE MULTIPLE ROUNDS OF HEAVY RAIN MOVE ACROSS THE
SAME AREA.
THE TOTAL AMOUNT OF RAIN SUNDAY NIGHT THROUGH MONDAY NIGHT
RANGES FROM NEAR A HALF INCH TO AMOUNTS BETWEEN 1 AND 2 INCHES.
SOME LOCALLY HIGHER RAINFALL AMOUNTS WILL BE POSSIBLE EXCEEDING
2 INCHES. THERE IS STILL QUITE A BIT OF UNCERTAINTY WITH THIS
BUT REFINED FORECASTS ARE EXPECTED TO NARROW DOWN WITH POSSIBLE
SHIFTS OF THIS RAINFALL RANGE IN SUBSEQUENT FORECASTS.
IN ADDITION, WHILE INSTABILITY WILL BE LIMITED WITH ALL THE
CLOUDS, THERE IS FORECAST SOME BULK SHEAR 30-40 KT 0-6 KM AGL,
SO THERE IS A MARGINAL RISK FOR SEVERE THUNDERSTORMS AS WELL.
MAIN THREAT WOULD BE WET MICROBURSTS.
RAIN WILL NOT BE AS WIDESPREAD TUESDAY INTO MIDWEEK BUT MORE
MODELS ARE INDICATING STILL THE CHANCE FOR SHOWERS AND
THUNDERSTORMS. A WETTER TREND TO THE FORECAST COMPARED TO
YESTERDAY.
AVIATION /19Z FRIDAY THROUGH WEDNESDAY/
HIGH PRESSURE REMAINS NEAR THE TERMINALS THROUGH THE TAF
PERIOD.
MAINLY VFR. CAN'T RULE OUT A POSSIBLE ISOLATED SHOWER THIS
AFTERNOON. THE BEST CHANCES WILL BE AT KGON AND KSWF. IN
ADDITION, SOME PATCHY FOG WILL BE POSSIBLE TONIGHT. WILL INCLUDE
A TEMPO FOR SOME LOWER VSBYS AT KGON, BUT CONFIDENCE NOT HIGH
ENOUGH TO INCLUDE AT THE OTHER TERMINALS.
WINDS WILL REMAIN RATHER LIGHT THROUGH THE TAF PERIOD. SEA
BREEZES HAVE ALREADY DEVELOPED AND ARE MOVING ACROSS LONG ISLAND
AND SOUTHERN CT. EXPECT THE SEABREEZE TO REACH KLGA AROUND 20Z
OR 21Z. WINDS FALL BACK BELOW 5KT TONIGHT AND INCREASE AGAIN ON
SATURDAY 5- 10KT FROM THE SOUTH.
...NY METRO (KEWR/KLGA/KJFK/KTEB) TAF UNCERTAINTY...
AMENDMENTS MAY BE NEEDED FOR TIMING OF ANY AFTERNOON SHOWERS.
OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY
SATURDAY: MAINLY VFR.
SUNDAY: MAINLY VFR, CHANCE OF A LATE DAY SHOWER OR TSTM.
MONDAY: SUB-VFR IN SHOWERS AND THUNDERSTORMS.
TUESDAY: SUB-VFR IN SHOWERS AND THUNDERSTORMS.
WEDNESDAY: SUB-VFR IN SHOWERS AND THUNDERSTORMS.
DETAILED INFORMATION, INCLUDING HOURLY TAF WIND COMPONENT FORECASTS,
CAN BE FOUND AT: HTTPS:/WWW.WEATHER.GOV/ZNY/N90
MARINE
CONDITIONS ON THE WATERS REMAIN MAINLY BELOW SCA THRESHOLDS
THROUGH SATURDAY NIGHT BUT THERE COULD BE SOME AREAS ON THE
WATERS BETWEEN SANDY HOOK NJ AND FIRE ISLAND INLET NY WHERE WIND
GUSTS REACH 25 KTS SATURDAY AFTERNOON INTO EARLY SATURDAY
EVENING.
MARGINAL SCA POTENTIAL FOR WIND GUSTS ON SUNDAY WITH HIGHER
CHANCES OF SCA CONDITIONS ON THE OCEAN EARLY NEXT WEEK AND
POSSIBLY FOR SOME NON-OCEAN MARINE ZONES ALSO.
RIP CURRENTS:
THERE REMAINS A MODERATE RISK FOR RIP CURRENTS AT LOCAL OCEAN
BEACHES TODAY AND SATURDAY. WINDS THIS AFTERNOON WILL BE LIGHT,
MAINLY UNDER 10 MPH, INCREASING TO 10-15 MPH ON SATURDAY. SSE
SWELLS 3 TO 4 FT AT AN 8 SEC PERIOD THROUGH THE PERIOD DRIVE THE
MODERATE RISK.
OKX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
DISCUSSION...JM
AVIATION...BC
MARINE...JM
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