455
FXUS61 KOKX 042028
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
428 PM EDT SUN MAY 4 2025
SYNOPSIS
A FRONTAL BOUNDARY ACROSS THE LOWER HUDSON VALLEY INTO CENTRAL
NEW ENGLAND WILL SETTLE SOUTH TONIGHT TO NEAR THE COAST AS HIGH
PRESSURE BUILDS SOUTHEAST OUT OF EASTERN CANADA. AT THE SAME
TIME, LOW PRESSURE WILL BE CUTOFF OVER THE TENNESSEE AND OHIO
VALLEYS. THE SYSTEM WILL THEN PASS THROUGH ON WEDNESDAY. ANOTHER
UPPER LEVEL DISTURBANCE MAY IMPACT THE AREA LATE IN THE WEEK.
HIGH PRESSURE WEST OF THE REGION WILL THEN ATTEMPT TO BUILD
INTO THE WEEKEND.
NEAR TERM /THROUGH MONDAY/
A CUTOFF UPPER LEVEL LOW WILL MEANDER ACROSS THE TENNESSEE AND
OHIO VALLEYS THROUGH TUESDAY, WHILE UPPER LEVEL RIDGING BUILDS
ACROSS EASTERN CANADA. THIS KEEPS THE AREA IN CLOSE PROXIMITY
TO A FRONTAL ZONE WITH A DEEP-LAYERED SOUTHERLY FLOW ALOFT. TO
THE EAST OF THE UPPER LOW, A WARM CONVEYOR BELT WILL SEND
SHOWERS AND EMBEDDED THUNDERSTORMS NORTH OFF THE OCEAN AND INTO
THE AREA. IN ADDITION, SE TO E WINDS WILL ENHANCE OROGRAPHIC
LIFT ACROSS CT, IN PARTICULAR AREAS OF WESTERN CT.THE LATTER OF
WHICH THOUGH REMAINS UNCERTAIN AS TIMING AND LOCATION OF THE
BANDS MAY CHANGE IN COMING DAYS. THESE LOOK TO BE NARROW CORRIDORS
OF MODERATE TO HEAVY SHOWERS WITH A SLIGHT CHANCE OF THUNDERSTORMS.
THERE IS NO DEEP CONVECTION WITH MARGINAL INSTABILITY AND PWAT
VALUES OF 1.25 TO 1.50". UPPER AIR SOUNDINGS ARE GENERALLY MOIST
ADIABATIC WITH DEEP-LAYERED LIFT. SPC HREF SHOWS VERY LOW
PROBABILITIES OF >1"/HOUR AND >3"/3 HOURS. FFG VALUES ARE
AROUND 2 INCHES/1-HOUR AND 3 INCHES/3-HOUR. THESE ARE UNLIKELY
TO BE ACHIEVED. ALSO, RIVER AND STREAM FLOW IS LOW. THUS, DRY
ANTECEDENT CONDITIONS AND LACK OF DEEP CONVECTION SHOULD LIMIT
ANY FLOODING TO PRIMARILY MINOR NUISANCE. HOWEVER, CAMS DO SHOW
BULLSEYES ACROSS THE AREA WITH SOME OF THE CONVECTION, SO ISOLATED
FLASH FLOODING IS A POSSIBILITY. WPC HAS THE AREA UNDER A MARGINAL
RISK THE NEXT COUPLE OF DAYS. THIS RAIN WILL NOT BE CONSTANT AS
THE BANDS REORGANIZE AND SETUP OVER DIFFERENT LOCATIONS.
GREATEST UNCERTAINTY WITH THIS FORECAST IS NOT WHETHER THERE
WILL BE BANDS OF MODERATE TO HEAVY RAIN, BUT RATHER THE
LOCATION. THE INITIAL THOUGHT IS MUCH OF THE LIFT WILL BE
COLLOCATED WITH THE LLJ WHICH SHIFTS EAST TONIGHT AND THEN BACK
TO THE WEST ON MONDAY. THIS IS LIKELY DO TO THE BUILDING HIGH
OUT OF SOUTHEAST CANADA FORCING THE GRADIENT TO VARY ACROSS THE
AREA. THE ACTIVITY OVER WESTERN AREAS THIS EVENING IS FORECAST
TO GRADUALLY TRANSLATE EAST OVERNIGHT AND THEN BACK TO WESTERN
PORTIONS ON MONDAY.
IT WILL REMAIN MILD WITH THE CLOUD COVER AND ONSHORE FLOW WITH
LOWS IN THE MID 50S TO AROUND 60. BLENDED IN CONSALL WITH NBM TO
GET VALUES A BIT COOLER WITH THE RAIN ON MONDAY WITH HIGHS IN
THE LOWER TO MID 60S.
SHORT TERM /MONDAY NIGHT THROUGH TUESDAY NIGHT/
MUCH OF THE AREA WILL CONTINUE TO SEE SHOWERS/ISOLATED THUNDERSTORMS
INTO TUESDAY. ONCE AGAIN, THERE IS SOME UNCERTAINTY WITH THE LOCATION
OF THE LLJ AND THE HEAVIER BANDS. RAINFALL AMOUNTS WILL LIKELY
NEED ADJUSTMENTS THROUGH IN SUBSEQUENT FORECASTS. THE UPPER LOW
WILL BEGIN TO EDGE EASTWARD ALONG WITH THE DEEPER MOISTURE AND
LIFT.
MUCH OF THE AREA IS EXPECTED TO SEE 2 TO 3 INCHES OF RAIN THROUGH
THE ENTIRETY OF THE EVENT. THE UPPER END OF THE AMOUNTS ARE
CURRENTLY FORECAST TO BE ACROSS WESTERN LI AND INTO SW CT. THIS
OF COURSE MAY VARY DUE TO THE AFOREMENTIONED UNCERTAINTY.
LOWS TUESDAY NIGHT WILL REMAIN ABOVE NORMAL IN THE MID AND UPPER
50S. HOWEVER, HIGHS DUE TO THE CLOUD COVER WILL BE CLOSER TO
NORMAL IN THE 60S.
LONG TERM /WEDNESDAY THROUGH SUNDAY/
OVERALL IMPROVING CONDITIONS TO BEGIN THE PERIOD AS ANY ORGANIZED OR
PROLONGED PRECIPITATION COMES TO AN END. HOWEVER, WITH AN UPPER
LEVEL LOW STILL LINGERING INTO WEDNESDAY, LOOK FOR DIURNALLY DRIVEN
POP-UP SHOWERS AND POSSIBLY A FEW ISOLATED THUNDERSTORMS MAINLY
DURING THE AFTERNOON AND EARLY EVENING HOURS ON MOST DAYS THROUGHOUT
THE WORK WEEK. THE FIRST UPPER LEVEL LOW PULLS AWAY LATE WED / WED
NIGHT, BUT TO ONLY BE FOLLOWED BY ANOTHER UPPER LEVEL DISTURBANCE
LATER THURSDAY AND POSSIBLY INTO A GOOD PORTION OF FRIDAY. GLOBAL
NWP GUIDANCE INDICATES MORE UNCERTAINTY WITH THE 2ND UPPER LEVEL LOW
/ DISTURBANCE LATE IN THE WEEK. SOME OF THE GLOBAL GUIDANCE
EVENTUALLY KICKS THE UPPER LEVEL DISTURBANCE AWAY INTO THE WEEKEND.
HOWEVER, SOME GUIDANCE SUGGEST THAT THE SYSTEM GETS COMPLETELY
CLOSED OFF, AND POSSIBLY CUT OFF FROM THE WESTERLIES. THE SECOND
SOLUTION APPEARS TO BE LESS LIKELY AT THIS TIME, BUT CANNOT BE
DISCOUNTED. HAVE CHOSEN TO KEEP NEXT WEEKEND DRY, BUT THIS COULD
CHANGE IF THE 2ND SOLUTION EMERGES MORE IN SUBSEQUENT NWP CYCLES.
TEMPERATURES WILL AVERAGE NEAR NORMAL TUESDAY NIGHT THROUGH LATE
THURSDAY. TEMPERATURES THEN MAY FALL A BIT BELOW NORMAL INTO FRIDAY,
BEFORE LIKELY RECOVERING TO NORMAL OR SLIGHTLY ABOVE SEASONABLE
LEVELS INTO THE WEEKEND.
AVIATION /19Z SUNDAY THROUGH FRIDAY/
FRONTAL BOUNDARY REMAINS STATIONARY ACROSS THE REGION TONIGHT.
AS A RESULT SHOWERS WILL CONTINUE TO DEVELOP AND GRADUALLY MAKE
THEIR WAY FARTHER EAST WITHIN THE REGION THROUGH TONIGHT.
MVFR CONDITIONS PERSIST THROUGH THIS EVENING WITH THE CHANCE OF
RAIN SHOWERS. HIGHER CHANCE OF IFR AND LOCALIZED LIFR CONDITIONS
EXPECTED TONIGHT AND INTO MONDAY.
SOUTHERLY WINDS BECOME MORE EASTERLY TONIGHT. WIND SPEEDS VARY
FROM NEAR 5 KTS TO NEAR 15 KTS. SOME GUSTS CAN BE EXPECTED
BETWEEN 20-25 KT AT TIMES ALTHOUGH THIS IS NOT EXPECTED TO BE
WIDESPREAD. WIND SPEEDS TONIGHT LOWER TO LESS THAN 10 KTS, THEN
INCREASE AGAIN MONDAY.
...NY METRO (KEWR/KLGA/KJFK/KTEB) TAF UNCERTAINTY...
AMENDMENTS LIKELY TO REFINE TIMING OF SHOWERS AND THUNDERSTORMS.
OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY
MONDAY: SHOWERS LIKELY WITH MVFR OR LOWER EXPECTED. A CHANCE OF
TSTMS MAINLY AT NIGHT. E WINDS G15-20KT.
TUESDAY: SHOWERS WITH MVFR OR LOWER EXPECTED. A CHANCE OF
THUNDERSTORMS. SE WINDS G15-20KT DAY INTO EARLY EVE POSSIBLE.
WEDNESDAY: CHANCE OF MVFR OR LOWER WITH A SLIGHT CHANCE OF
SHOWERS/THUNDERSTORMS.
THURSDAY: VFR.
FRIDAY: VFR WITH SLIGHT CHANCE OF SHOWERS.
DETAILED INFORMATION, INCLUDING HOURLY TAF WIND COMPONENT
FORECASTS, CAN BE FOUND AT: HTTPS:/WWW.WEATHER.GOV/ZNY/N90
MARINE
EXPECTING ALL WATERS TO REMAIN BELOW SCA THROUGH MONDAY
MORNING. MARGINAL SCA CONDITIONS ARE POSSIBLE ON THE OCEAN
WATERS MONDAY INTO TUESDAY WITH E/SE WINDS AND SEAS BUILDING
CLOSE TO 5 FT. NWPS GUIDANCE WAS USED BASED ON FORECAST WINDS.
HOWEVER, NBM AND WAVEWATCH WERE AROUND 5 FT. STAYED WITH THE
LOWER GUIDANCE AT THIS TIME.
OCEAN SEAS GRADUALLY SUBSIDE BELOW SMALL CRAFT CRITERIA TUESDAY
NIGHT WITH AS OCEAN SEAS SETTLE IN AT AROUND 4 FT THROUGH THURSDAY.
MARGINAL SMALL CRAFT CONDITIONS ARE POSSIBLE TOWARDS LATER THURSDAY
NIGHT, ESPECIALLY OUT ON THE OCEAN AS THE WINDS BECOME MORE
NORTHERLY.
HYDROLOGY
TOTAL RAINFALL FORECAST THROUGH TUESDAY EVENING IS 1.5 TO 3.5
INCHES. LOCALLY HIGHER AMOUNTS WILL BE POSSIBLE. THERE IS A
MARGINAL RISK FOR EXCESSIVE RAINFALL (LOCALIZED FLASH FLOODING).
THIS WILL BE A LONG DURATION EVENT AND CURRENT THINKING IS THAT
ANY FLOODING WILL BE MORE OF THE MINOR NUISANCE VARIETY. SEE
THE NEAR TERM SECTION ABOVE FOR MORE DETAILS ON REASONING.
PREDOMINANTLY DRY CONDITIONS RETURN WITH MAINLY DIURNALLY DRIVEN
WIDELY SCATTERED SHOWER / THUNDERSHOWER ACTIVITY TOWARDS MID AND
LATE WEEK. THUS THERE ARE NO HYDROLOGIC CONCERNS FOR THE MID AND
LATE WEEK.
OKX WATCHES/WARNINGS/ADVISORIES
CT...NONE.
NY...NONE.
NJ...NONE.
MARINE...NONE.
SYNOPSIS...JE/DW
NEAR TERM...DW
SHORT TERM...DW
LONG TERM...JE
AVIATION...20
MARINE...JE/DW
HYDROLOGY...JE/DW
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