809
FXUS61 KOKX 211139
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
739 AM EDT SUN JUN 21 2026
WHAT HAS CHANGED
SLIGHT RISK OF EXCESSIVE RAINFALL HAS SHIFTED SOUTH TO ONLY
INCLUDE NE NJ AND THE NYC METRO WITH A MARGINAL RISK ELSEWHERE.
KEY MESSAGES
1) ISOLATED SHOWERS AND A RUMBLE OF THUNDER POSSIBLE THIS
AFTERNOON, MAINLY ACROSS THE INTERIOR.
2) HEAVY RAINFALL MONDAY AFTERNOON INTO MONDAY NIGHT WILL BRING
THE POTENTIAL OF URBAN AND POOR DRAINAGE FLOOD IMPACTS, AS WELL
AS LOCALIZED FLASH FLOODING.
3) THERE IS A MARGINAL RISK FOR SEVERE THUNDERSTORMS IN THE
VICINITY OF NE NJ AND THE NYC METRO MONDAY AFTERNOON AND
EVENING.
4) SHOWERS AND THUNDERSTORMS ARE POSSIBLE THURSDAY AND FRIDAY.
DISCUSSION
KEY MESSAGE 1
THE PASSAGE OF A SHORTWAVE THIS AFTERNOON MAY DEVELOP
ISOLATED SHOWERS, MAINLY ACROSS THE INTERIOR. INSTABILITY BASED
ON FORECAST SOUNDINGS IS RELATIVELY SHALLOW, BUT THERE IS
ENOUGH PRESENT ABOVE THE FREEZING LEVEL TO SUPPORT POTENTIAL OF
A FEW LIGHTNING STRIKES. DRY SUBCLOUD LAYER ALSO SUPPORTS
LOCALLY GUSTY WINDS IN ANY OF THE ISOLATED SHOWERS. ANY SHOWER
DEVELOPMENT THIS AFTERNOON WILL QUICKLY DISSIPATE THIS EVENING
AS THE SHORTWAVE ENERGY PASSES TO THE EAST.
KEY MESSAGE 2
DEVELOPING LOW PRESSURE OVER THE PLAINS TODAY WILL QUICKLY MOVE
EAST TOWARDS THE AREA TONIGHT. AN ASSOCIATED WARM FRONT WILL
APPROACH MONDAY MORNING AND SET UP NEAR THE REGION MONDAY
AFTERNOON AND EVENING. THE SYSTEM HAS THE POTENTIAL TO BRING
PERIODS OF MODERATE TO LOCALLY HEAVY SHOWERS AND THUNDERSTORMS
MONDAY AFTERNOON INTO MONDAY NIGHT.
THE MODELING IS CONTINUING TO STRUGGLE WITH THE PLACEMENT OF THE
WARM FRONT AND AXIS OF HEAVIEST RAINFALL. SOME OF THIS UNCERTAINTY
IS TIED TO CONVECTIVE ERRORS WITH TIMING/STRENGTH/LOCATION OF THE
SYSTEM. HIGH RESOLUTION MODELS ARE STARTING TO COME INTO RANGE, BUT
OFFER LITTLE AGREEMENT ON THE EVOLUTION OF WHERE THE HEAVIEST
RAINFALL/CONVECTION WILL ULTIMATELY OCCUR.
DESPITE THE AFOREMENTIONED UNCERTAINTIES, THE SYNOPTIC ENVIRONMENT
SUPPORTS DEEP MOISTURE CONVERGENCE IN THE VICINITY OF THE WARM
FRONT/LOW PRESSURE. MODELS CONTINUE TO SIGNAL POTENTIAL OF
PRECIPITABLE WATERS RANGING FROM 1.75-2.25", ESPECIALLY MONDAY
AFTERNOON AND EVENING. FORECAST SOUNDINGS ALSO INDICATE A FAIRLY
DEEP WARM CLOUD LAYER WITH FREEZING LEVELS PROGGED AROUND 12-14KFT.
THIS IS A GOOD INDICATION OF EFFICIENT WARM RAIN PROCESSES AND
SUPPORTS THE POTENTIAL OF HEAVY DOWNPOURS.
THE GREATEST POTENTIAL FOR HEAVY RAIN APPEARS TO BE LATE MONDAY
AFTERNOON INTO THE FIRST HALF OF MONDAY NIGHT WHEN THERE WILL
LIKELY BE A COMBO OF DEEP MOISTURE POOLING IN THE VICINITY OF
THE WARM FRONT AND SUPPORT ALOFT FROM THE APPROACH OF A MIDDLE
LEVEL SHORTWAVE. SOME OF THE GLOBAL MODELS ALSO SIGNAL
AMPLIFICATION OF AN UPPER JET OVER NORTHERN NEW ENGLAND, WHICH
MAY HELP WITH HEAVY RAIN DEVELOPMENT MONDAY EVENING.
AVERAGE BASIN RAINFALL AMOUNTS CONTINUE TO RANGE FROM 1-2 INCHES
WITH LOCALLY HIGHER AMOUNTS POSSIBLE. RAINFALL RATES MAY REACH 1-
1.5"/HR AND COULD LOCALLY REACH 2"/HR. THIS SUPPORTS THE POTENTIAL
FOR URBAN/POOR DRAINAGE FLOODING AND MAINLY A LOCALIZED FLASH FLOOD
RISK. THE MAIN CONCERN APPEARS TO BE ACROSS THE HEAVILY URBANIZED NE
NJ AND THE NYC METRO WHERE THESE RAINFALL RATES CAN PRODUCE URBAN
FLASH FLOODING.
THE RISK FOR RIVER AND STREAM FLOODING IS LOW AS RECENT DRY
CONDITIONS HAVE LED TO FAIRLY HIGH FLASH FLOOD/HEADWATER GUIDANCE.
AROUND 2 INCHES IN AN HOUR AND 2-3 INCHES IN 3 HOURS IS NEEDED
FOR FLASH FLOODING ACROSS NE NJ. ACROSS THE INTERIOR AND
SOUTHERN CT, 3 INCHES IN AN HOUR AND 4 INCHES IN 3 HOURS IS
NEEDED TO REACH MINOR FLOOD STAGE ON RIVERS/STREAMS. CANNOT
COMPLETELY RULE OUT SOME OF THE FLASHIER STREAMS REACHING MINOR
FLOOD STAGE BASED ON THE 3 HOUR GUIDANCE.
IN COLLABORATION WITH WPC AND NEIGHBORING OFFICES, THE SLIGHT
RISK FOR EXCESSIVE RAINFALL HAS BEEN SCALED BACK TO MAINLY
INCLUDE URBAN NE NJ AND THE NYC METRO IN OUR CWA. ELSEWHERE, THE
RISK IS MARGINAL, WHICH IS SUPPORTED BY THE RECENT DRY
CONDITIONS, HIGH FLASH FLOOD/HEADWATER GUIDANCE, AND
EXPECTATION THAT THESE AREAS CAN HANDLE THE HEAVY RAIN
POTENTIAL COMPARED TO THE URBAN CORRIDOR.
THERE HAS BEEN A TREND IN THE LAST 24 HOURS TO LINGER SHOWERS,
POTENTIALLY EMBEDDED THUNDER LATE MONDAY NIGHT INTO EARLY TUESDAY.
THIS IS DUE TO A SLOWER TIMING OF THE LOW PRESSURE, WHICH MAY NOT
COMPLETELY MOVE EAST OF THE AREA UNTIL TUESDAY AFTERNOON. THE HEAVY
RAIN/FLOODING THREAT SHOULD DIMINISH AFTER MIDNIGHT, BUT A FEW
LOCALLY HEAVY DOWNPOURS COULD LINGER ACROSS LONG ISLAND/SE CT
INTO THE FIRST HALF OF TUESDAY MORNING.
KEY MESSAGE 3
CONFIDENCE IN SEVERE THUNDERSTORMS MONDAY AFTERNOON AND EVENING
CONTINUES TO BE LOW AT THIS TIME. INSTABILITY LOOKS TO BE
MAXIMIZED TO THE SOUTH OF THE AREA ACROSS THE MIDDLE ATLANTIC.
HOWEVER, THE WARM FRONT NEARBY OR OVER THE AREA COULD BE A
MECHANISM TO SUPPORT ISOLATED SEVERE THUNDERSTORM DEVELOPMENT.
CURRENTLY, THIS POTENTIAL LOOKS TO BE MAINLY ACROSS NE NJ, NYC
METRO, AND WESTERN LONG ISLAND WHERE SPC HAS CONTINUED WITH A
MARGINAL RISK. THE MAIN THREAT IS FROM DAMAGING WIND GUSTS AND
AN ISOLATED TORNADO DUE TO LOW LEVEL DIRECTIONAL SHEAR AND
PROXIMITY OF THE WARM FRONT. THE SEVERE THREAT COULD INCREASE
AND COVER MORE OF THE AREA IF THE INSTABILITY AND WARM FRONT
WERE TO TREND NORTH.
KEY MESSAGE 4
SOUTHWEST FLOW ALOFT LOOKS TO SET UP BY LATE THURSDAY INTO
FRIDAY AHEAD OF THE NEXT SHORTWAVE/COLD FRONT. THIS WOULD HELP
TO TRIGGER THE POTENTIAL FOR SHOWERS AND A FEW THUNDERSTORMS.
CONFIDENCE IS STARTING TO INCREASE THAT THE GREATEST POTENTIAL
ENDS UP ON FRIDAY WHEN THE SHORTWAVE AXIS IS CURRENTLY PROGGED
TO MOVE ACROSS THE AREA. ANY SEVERE/HYDRO IMPACTS ARE UNCERTAIN
AT THIS TIME SINCE THIS IS 5-6 DAYS OUT.
AVIATION /12Z SUNDAY THROUGH THURSDAY/
WEAK HIGH PRESSURE WILL BE IN PLACE THROUGH TONIGHT.
MAINLY VFR. SOME SHOWERS WITH BRIEF MVFR CONDS ARE POSSIBLE
THIS AFTERNOON INTO EARLY EVENING. CAN'T RULE OUT THUNDER AS
WELL, BUT NOT ENOUGH PROBABILITY TO INCLUDE IN TAFS.
WESTERLY WINDS UNDER 10KT BCMG W-SW AROUND 10KT LATER THIS
MORNING. SEA BREEZES PROBABLE FOR SOME OF THE COASTAL TERMINALS
LATE THIS MORNING INTO THE AFTERNOON.
...NY METRO (KEWR/KLGA/KJFK/KTEB) TAF UNCERTAINTY...
SHIFTS TO SW, THEN S MAY BE OFF BY AN HOUR OR TWO AT KJFK. SEA
BREEZE POTENTIALLY DOES NOT REACH KLGA, WHICH WOULD THEN LEAD TO
WINDS REMAINING WESTERLY ALL AFTERNOON.
OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY
MONDAY-MONDAY NIGHT: VFR IN THE MORNING, LOWERING TO MVFR AND
LOWER IN THE AFTERNOON WITH RAIN. RAIN AND IFR AT NIGHT. CHANCE
OF A THUNDERSTORM AS WELL BOTH AFTERNOON AND NIGHT. SE GUSTS
AROUND 20KT POSSIBLE.
TUESDAY: IFR WITH LINGERING RAIN/SHOWERS TO START. IMPROVING TO MVFR
IN THE AFTERNOON, THEN VFR LATE IN THE DAY. STILL A CHANCE OF A
SHOWER DURING THE AFTERNOON.
WEDNESDAY: VFR.
THURSDAY: VFR IN THE MORNING. CHANCE OF MVFR IN THE AFTERNOON WITH
POTENTIAL SHOWERS/TSTMS. SOUTHERLY WIND GUSTS 15-20 KT POSSIBLE IN
THE AFTERNOON INTO EVENING.
DETAILED INFORMATION, INCLUDING HOURLY TAF WIND COMPONENT
FORECASTS, CAN BE FOUND AT: HTTPS:/WWW.WEATHER.GOV/ZNY/N90
MARINE
WINDS AND SEAS WILL BE BELOW SCA LEVELS THROUGH MONDAY MORNING.
THE NEXT CHANCE FOR SCA CONDITIONS WILL BE LATE MONDAY INTO
MONDAY NIGHT WHEN WINDS AND SEAS RAMP UP, ESPECIALLY ON THE
OCEAN. SEAS SUBSIDE TUESDAY MORNING, WITH HIGH PRESSURE LIKELY
KEEPING CONDITIONS BELOW SCA LEVELS FROM LATE TUESDAY THROUGH
THURSDAY.
RIP CURRENTS:
THE RIP CURRENT RISK IS MODERATE AT SE SUFFOLK BEACHES WHERE A
3FT S SWELL @ 8 SECONDS LIKELY PERSISTS. THE RIP CURRENT RISK
IS LOW FOR THE REST OF THE OCEAN BEACHES WITH A 2FT S SWELL @ 8
SECONDS.
ON MONDAY, THE RIP CURRENT RISK IS MODERATE, ESPECIALLY IN THE
AFTERNOON AND EVENING WITH INCREASING S FLOW AND WIND WAVES
3-4 FT. THE RISK COULD BECOME HIGH LATE IN THE DAY FOR WESTERN
BEACHES IF HIGHER WINDS AND WIND WAVES OCCUR EARLIER THAN
CURRENTLY EXPECTED.
OKX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
DISCUSSION...DS
AVIATION...JC
MARINE...DS
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