995
FXUS61 KOKX 122355
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
755 PM EDT MON MAY 12 2025
SYNOPSIS
A WEAK BACKDOOR COLD FRONT MOVES ACROSS THE REGION TONIGHT AS
HIGH PRESSURE BUILDS SOUTHWARD OFF THE NEW ENGLAND COAST.
MEANWHILE, AN AREA OF LOW PRESSURE SLOWLY APPROACHES FROM THE
MID-ATLANTIC TUESDAY AND WEDNESDAY AND PASSES NEARBY DURING
THURSDAY. A WARM FRONT THEN MOVES THROUGH DURING FRIDAY,
FOLLOWED BY A COLD FRONT ON SATURDAY INTO SATURDAY NIGHT. WEAK
HIGH PRESSURE WILL THEN BE IN PLACE FOR SUNDAY AND MONDAY WITH A
FEW WEAK COLD FRONTS OR TROUGHS POSSIBLY PASSING THROUGH.
NEAR TERM /UNTIL 6 AM TUESDAY MORNING/
THE FORECAST REMAINS MAINLY ON TRACK. MINOR ADJUSTMENTS WERE
MADE TO SOME OF THE HOURLY FORECAST ELEMENTS WITH THIS UPDATE.
CLOUDS GRADUALLY INCREASE AS A BROAD AREA OF LOW PRESSURE APPROACHES
FROM THE SOUTH. MEANWHILE, HIGH PRESSURE WELL NORTH OF THE REGION
GRADUALLY BUILDS SOUTHEASTWARD, FORCING A BACK DOOR COLD FRONT TO
APPROACH FROM THE NORTHEAST. WITH THE LOW PRESSURE SYSTEM
APPROACHING FROM THE SOUTH, SOME RAIN SHOWERS MAY DEVELOP AFTER
MIDNIGHT, MAINLY ACROSS NE NJ AND NYC. WILL INTRODUCE SOME
CHANCE OR SLIGHT CHANCE POPS. ANY SHOWERS SHOULD REMAIN LIGHT IN
INTENSITY. THE EASTWARD PROGRESSION OF THIS BAND OF SCATTERED
SHOWERS REMAINS A BIT UNCERTAIN AS THE SHOWERS WILL BE RUNNING
INTO THE DRIER AIRMASS FROM THE HIGH PRESSURE OFFSHORE.
WITH INCREASING CLOUD COVER, TEMPERATURES SHOULD REMAIN SOMEWHAT
MILD, WITH LOWS ONLY FALLING INTO THE 50S TO LOWER 60S IN THE NYC
METRO AREA.
SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/
A BACKDOOR COLD FRONT CONTINUES TO MOVE INTO THE AREA TUESDAY
MORNING AND EITHER MOVES THROUGH THE ENTIRE AREA OR STALLS OVER THE
AREA AS A STATIONARY BOUNDARY. MEANWHILE, THE BROAD AREA OF LOW
PRESSURE CONTINUES TO SPREAD PRECIPITATION INTO PORTIONS OF THE CWA.
THE BEST CHANCES WILL BE ACROSS THE WESTERN HALF OF THE CWA,.
THERE REMAINS SOME UNCERTAINTY WITH JUST HOW FAR EAST THE
PRECIPITATION REACHES. SOME EASTERN AREAS MAY REMAIN MOSTLY DRY
DURING THIS TIMEFRAME. CLOUDY SKIES SHOULD PREVENT TEMPERATURES FROM
RISING TOO MUCH TUESDAY WITH HIGHS IN THE UPPER 60S TO MIDDLE 70S
FOR THE NORTHEASTERNMOST AREAS. TUESDAY NIGHT LOWS ONLY FALL INTO
THE MIDDLE AND UPPER 50S.
LONG TERM /WEDNESDAY THROUGH MONDAY/
MODELS IN GOOD AGREEMENT WITH A CLOSED H5 LOW OPENING UP AS IT HEADS
NE INTO THE GREAT LAKES REGION WEDNESDAY INTO WEDNESDAY NIGHT.
ASSOCIATED TROUGH AXIS SHIFTS THROUGH THE FORECAST AREA DURING
THURSDAY NIGHT. AT THE SURFACE, WEAKENING LOW PRESSURE OVER THE MID-
ATLANTIC ON WEDNESDAY SLOWLY APPROACHES AND PASSES OVER OR NEARBY US
AT SOME POINT IN THE THURSDAY TO THURSDAY NIGHT PERIOD. RAIN WILL BE
POSSIBLE AT ANY GIVEN TIME DURING THIS PERIOD, HOWEVER IT APPEARS
THAT IT WILL BE MOST LIKELY DURING THE DAYTIME WEDNESDAY. THIS IS
WHEN THE STRONGEST H8 THETA-E ADVECTION AND ISENTROPIC LIFT WITH THE
HELP OF LLJ UPWARD FORCING INTERACT WITH THE DEEPEST MOISTURE. THE
MAGNITUDE OF THE MOISTURE DOESN'T APPEAR TO BE SIGNIFICANTLY
ANOMALOUS, SO HYDROLOGIC IMPACTS ARE NOT ANTICIPATED AT THIS TIME.
EVEN THE NBM PROBABILITIES OF 6-HOUR RAINFALL BEING GREATER THAN A
HALF INCH THROUGH THE PERIOD ARE VERY LOW.
EVEN WITH THE STRONGEST FORCING AND DEEPEST MOISTURE SHIFTING AWAY,
RAINFALL IS STILL LIKELY DURING WEDNESDAY NIGHT AS THE
AFOREMENTIONED WEAK LOW APPROACHES. INDICATIONS ARE THAT THE LOW
WEAKENS INTO A TROUGH BY THE TIME OF ITS CLOSEST APPROACH, SO POPS
ARE CAPPED AT CHANCE (40-50% MOST LOCATIONS) FOR THURSDAY, BUT WENT
ABOVE NBM GUIDANCE CONSIDERING THE PROXIMITY OF THE TROUGH AS WELL
AS A SHORTWAVE AND TROUGH AXIS ALOFT SHIFTING THROUGH.
A WARM FRONT THEN SHIFTS THROUGH DURING FRIDAY WITH WITH RIDGING
ALOFT MITIGATING SHOWER CHANCES. A COLD FRONT FOLLOWS FOR SATURDAY
INTO SATURDAY NIGHT WITH ADDITIONAL SHOWERS AND MAYBE A THUNDERSTORM.
UNCERTAINTY THEN INCREASES FOR SUNDAY AND MONDAY, STEMMING FROM
GLOBAL MODEL DISAGREEMENT ON THE PLACEMENT OF AN UPPER LOW. THERE'S
GENERAL AGREEMENT THAT IT REMAINS TO OUR NORTH, BUT STILL CANNOT
RULE OUT A DIURNALLY-DRIVEN SHOWER BOTH DAYS AS A SURFACE TROUGH AND
CYCLONIC FLOW ALOFT ARE POTENTIALLY IN THE AREA.
AVIATION /00Z TUESDAY THROUGH SATURDAY/
DURING THE TAF PERIOD, A WEAK COLD FRONT MOVES INTO THE AREA
FROM THE NORTH. HIGH PRESSURE WILL CONTINUE MOVING OFFSHORE.
LARGE AREA OF LOW PRESSURE APPROACHES SLOWLY FROM THE SOUTHWEST.
VFR CONDITIONS EXPECTED THROUGH EARLY TUESDAY AFTERNOON. MVFR
CHANCES INCREASE FROM WEST TO EAST THEREAFTER FOR THE REST OF
THE TAF PERIOD.
SOME LIGHT RAIN IS POSSIBLE EARLY TUESDAY FOR NYC AND LOWER
HUDSON VALLEY TERMINALS. THERE ARE HIGHER CHANCES OF RAIN MOVING
INTO NYC AND LOWER HUDSON VALLEY TERMINALS TUESDAY AFTERNOON
INTO START OF TUESDAY EVENING WITH MVFR CHANCES ALSO INCREASING.
TO THE EAST, EXPECTING MAINLY DRY CONDITIONS AND VFR CONDITIONS
EXPECTED TO PREVAIL THROUGH MUCH OF THE AFTERNOON.
WINDS THROUGH THE TAF PERIOD AROUND 10 KTS OR LESS. WIND
DIRECTION SOUTHERLY THIS EVENING, WITH SOME VARIABILITY
OVERNIGHT, BECOMES GENERALLY MORE EASTERLY TUESDAY.
...NY METRO (KEWR/KLGA/KJFK/KTEB) TAF UNCERTAINTY...
MVFR AND IFR TIMING COULD BE A FEW HOURS OFF FROM TAF.
OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY
TUESDAY NIGHT THROUGH WEDNESDAY NIGHT: LOW STRATUS/FOG WITH IFR
CONDITIONS AT TIMES. PERIODS OF RAIN. SLIGHT CHANCE OF
THUNDERSTORMS WEDNESDAY AFTERNOON INTO WEDNESDAY NIGHT. E-SE
WINDS G20KT POSSIBLE ON WEDNESDAY, DAY INTO EARLY EVENING.
THURSDAY: MVFR POSSIBLE WITH A CHANCE OF SHOWERS.
FRIDAY AND SATURDAY: MAINLY VFR, CHANCE OF MVFR AND SHOWERS.
SLIGHT CHANCE OF THUNDERSTORMS AFTERNOON INTO EARLY EVENING.
DETAILED INFORMATION, INCLUDING HOURLY TAF WIND COMPONENT FORECASTS,
CAN BE FOUND AT: HTTPS:/WWW.WEATHER.GOV/ZNY/N90
MARINE
SUB-SCA CONDITIONS ARE EXPECTED ON ALL WATERS THROUGH TUESDAY
NIGHT. ONSHORE FLOW WILL HELP BUILD SEAS TO 5-6 FT ON THE
OCEAN WATERS DURING WEDNESDAY ALONG WITH GUSTS AROUND 25 KT.
WINDS WEAKEN WEDNESDAY NIGHT, HOWEVER A RESIDUAL SWELL SHOULD
KEEP SEAS AT ADVISORY LEVELS THROUGH THE NIGHT AND INTO A
PORTION OF THURSDAY. SUB-ADVISORY CONDITIONS THEN FOLLOW FOR
THURSDAY NIGH THROUGH SATURDAY WITH WINDS REMAINING AT AROUND
10KT OR LESS.
HYDROLOGY
RAINFALL FROM TUESDAY AFTERNOON THROUGH WEDNESDAY NIGHT IS EXPECTED
TO AVERAGE AROUND A HALF OF AN INCH ACROSS THE AREA. NO HYDROLOGIC
IMPACTS ARE EXPECTED WITH THIS EVENT, AND NO IMPACTS ARE EXPECTED
THEREAFTER THROUGH MONDAY.
OKX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
SYNOPSIS...BC/JC
NEAR TERM...BC
SHORT TERM...BC
LONG TERM...JC
AVIATION...JM
MARINE...BC/JC
HYDROLOGY...BC/JC
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