296
FXUS61 KOKX 050009
AFDOKX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE NEW YORK NY
809 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/
LOCALLY MODERATE TO SOME EMBEDDED HEAVY RAINFALL HAS TAKEN PLACE
ACROSS FAR NW PORTIONS OF THE CWA. THIS ACTIVITY HAS BEEN DRIVEN
BY A CONVEYOR BELT OF MOIST SSE FLOW GOING OVER HIGHER TERRAIN.
THIS OROGRAPHICALLY INDUCED HEAVIER RAINFALL HAS LED TO
RAINFALL AMOUNTS OF 1.5 TO JUST ABOVE 2 INCHES OF RAIN OVER THE
PAST 6-8 HOURS. THE HIGHEST RAINFALL RATES HAVE OCCURRED JUST
TO THE NORTH OF NW PORTIONS OF THE CWA INTO THE CATSKILLS WHERE
HIGHER HOURLY RAINFALL RATES HAVE BEEN ACHIEVED. LUCKILY, DRY
ANTECEDENT CONDITIONS WERE IN PLACE INITIALLY, BUT WITH SUNDAY'S
RAINFALL SOIL MOISTURE AND OTHER HYDROLOGIC METRICS HAVE COME
UP FOR THESE AREAS. GOING FORWARD THESE AREAS (MAINLY W AND NW
ORANGE COUNTY) WILL HAVE TO BE MONITORED FOR POTENTIAL SHORT
FUSED HYDRO FLOOD RELATED PRODUCTS. ONCE FFG UPDATES FROM ALL OF
THE PREVIOUS RAINFALL THIS CAN BE RE- EVALUATED. PREVIOUS
SYNOPTIC RELATED DISCUSSION FOLLOWS.
A CUTOFF UPPER LEVEL LOW MEANDERS 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 APPEAR TO BE
DIFFICULT TO ACHIEVE. ALSO, RIVER AND STREAM FLOW HAS BEEN 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
ISSUED MESOSCALE DISCUSSION ON THIS ACTIVITY AND WPC HAS
MAINTAINED THE MARGINAL RISK ACROSS THE AREA THE NEXT COUPLE OF
DAYS. THIS RAIN SHOULD NOT BE CONSTANT AS THE BANDS ARE EXPECTED
TO REORGANIZE AND SETUP OVER DIFFERENT LOCATIONS GOING FORWARD.
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 /00Z MONDAY THROUGH FRIDAY/
A FRONTAL BOUNDARY REMAINS NEARLY STATIONARY IN THE VICINITY
THROUGH MONDAY.
CIGS LOWERING BELOW 500 FEET BY MIDNIGHT ACROSS THE ENTIRE AREA,
AND LIKELY REMAINING THAT WAY TROUGH THE TAF PERIOD WITH RAIN
AND SHOWERS.
ESE-E WINDS 5-10KT BACK MORE E-ENE FOR THE MONDAY MORNING PUSH,
THEN INCREASE TO CLOSER TO AROUND 10KT BY THE END OF THE PUSH.
...NY METRO (KEWR/KLGA/KJFK/KTEB) TAF UNCERTAINTY...
TEMPO VFR CIGS STILL POSSIBLE AT KEWR AND KTEB UNTIL 01-02Z.
CIGS COULD IMPROVE TO 600-800FT AFTER THE MONDAY MORNING PUSH
FOR KEWR AND KTEB. A FEW GUSTS UP TO AROUND 20KT POSSIBLE
MAINLY FOR KJFK AND KLGA AFTER AROUND 14-15Z.
OUTLOOK FOR 00Z TUESDAY THROUGH FRIDAY
MON NIGHT: RAIN/SHOWERS AND IFR.
TUESDAY: RAIN/SHOWERS AND IFR. SLIGHT CHANCE OF AN
AFTERNOON/EVENING THUNDERSTORM. E-SE GUSTS 15-20KT 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...JE/DW
SHORT TERM...DW
LONG TERM...JE
AVIATION...JC
MARINE...JE/DW
HYDROLOGY...JE/DW
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