Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 010751 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 351 AM EDT WED JUL 1 2015 .SYNOPSIS... A WARM FRONT WILL LIFT NORTHEAST THROUGH THE AREA THIS AFTERNOON. A COLD FRONT WILL MOVE ACROSS WEDNESDAY NIGHT. CANADIAN HIGH PRESSURE WILL BUILD ACROSS THE AREA FROM THURSDAY INTO FRIDAY. WAVES OF LOW PRESSURE WILL TRAVERSE A STATIONARY FRONT TO THE SOUTH THROUGH THE WEEKEND. A WARM FRONT WILL LIFT THROUGH ON MONDAY...WITH A COLD FRONT APPROACHING MONDAY NIGHT INTO TUESDAY. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... SOUTHERN STREAM SHORTWAVE MOVES UP THE COAST THIS MORNING...WITH APPROACHING UPPER TROUGH PIVOTING THROUGH THE REGION LATER THIS MORNING THROUGH MID AFTERNOON. AT THE SURFACE...A WARM FRONT/WEAK WAVE...PROGRESSES TOWARDS THE REGION THIS MORNING...LIFTING NORTHEAST BY EARLY AFTERNOON. THEN A COLD FRONT ENTERS THE REGION FROM THE WEST LATER THIS AFTERNOON. NUMEROUS HEAVY SHOWERS AND SCT TSTMS NOTED WITH THIS FEATURE ACROSS EASTERN PA AND SOUTHERN NJ THIS MORNING. MAIN THREAT WILL BE HEAVY DOWNPOURS AND FLASH FLOODING AS PWATS INCREASE TO 1.75 INCHES. RAINFALL OF 1 TO 2 INCHES IN AN HOUR HAVE BEEN DETECTED ACROSS SE PA. FLASH FLOOD WATCH IN EFFECT THROUGH THE MORNING COMMUTE TO ADDRESS HAZARD. SEE HYDRO SECTION FOR MORE DETAILS. WITH STRONG SHEAR PROFILES AND LLJ...CANT RULE OUT AN ISOLATED STRONG TO SEVERE STORM...WITH EVEN SOME WEAK ROTATION ALONG WARM FRONT/WAVE. SOUTHERN CT MAY BE THE PLACE TO WATCH AS THE WARM FRONTAL/SURFACE WAVE MOVEMENT COINCIDES WITH APPROACHING SHORTWAVE LATER THIS MORNING AND BUILDING DIURNAL INSTABILITY. IN WAKE OF WARM FRONT/WAVE...BEST LLJ/MOISTURE AXIS APPEARS TO SLIDE EAST OF THE REGION. SO UNCERTAINTY FOR LATE MORNING/EARLY AFTERNOON CONVECTION IN TERMS OF AMOUNT OF DESTABILIZATION BEFORE SHORTWAVE PASSAGE. ISO-SCT CONVECTION POSSIBLE AHEAD OF COLD FRONT ACROSS FAR WESTERN PORTIONS OF THE REGION...OR ALONG ANY THERMAL OR LINGERING PRE-FRONTAL TROUGH IN VICINITY OF NYC/NJ METRO AND SW CT THROUGH EARLY AFTERNOON. IF CONVECTION CAN DEVELOP...IT HAS POTENTIAL TO BE SEVERE. THEREAFTER...SETUP DOES NOT LOOK FAVORABLE FOR WIDESPREAD CONVECTION LATE IN THE LATE AFTERNOON INTO EARLY EVENING AS SHORTWAVE AXIS IS ALREADY EAST OF THE REGION. COVERAGE SHOULD BE MORE ISOLATED ALONG THE LAGGING COLD FRONT AS IT PASSES THROUGH...WITH A DIMINISHED SEVERE THREAT DUE TO SUBSIDENCE AND A DRYING AIRMASS. HIGHS IN THE LOWER TO MID 80S TODAY. && .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY/... MAIN SHORTWAVE AXIS SLIDES EAST OF THE REGION BY THIS EVENING...BUT A WEAKER BACKSIDE SHORTWAVE MAY MOVE THROUGH AROUND 00Z. THEREAFTER...THE REGION WILL BE ON THE SE FRINGE OF MEAN TROUGHING THU AND FRI AS UPPER LOW SPINS NE THROUGH QUEBEC AND EASTERN CANADA. AT THE SURFACE...THE WEAK COLD FRONT SLOWLY SLIDES EAST THROUGH THE REGION TONIGHT. ISOLATED SHRA/TSRA ACTIVITY POSSIBLE ALONG THE FRONT IN THE EVENING WITH MARGINAL INSTABILITY AND WEAK SHORTWAVE FORCING...BUT THIS SHOULD COME TO AN END LATER IN THE EVENING IN WAKE OF SHORTWAVE. GENERALLY DRY CONDITIONS THU AND FRI AS COLD FRONT PUSHES SOUTH OF THE AREA AND WEAK HIGH PRESSURE BUILDS INTO THE REGION. THERE IS A LOW PROB OF A PERIOD OF SHOWERS ACROSS SOUTHERN PORTIONS OF THE TRI-STATE THU NIGHT AS A WEAK SHORTWAVE APPROACHES...AND WAVE TO THE SOUTH MAY MAKE A CLOSE RUN. TEMPS WILL RUN NEAR SEASONABLE. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... ON SATURDAY...THERE IS STILL SOME CHANCE OF MOISTURE TRIGGERING SOME SCATTERED SHOWERS/THUNDERSTORMS...BUT WILL LOWER POPS FOR MOST OF THE AREA SATURDAY AFTERNOON AND EVENING. TEMPERATURES ON SATURDAY SHOULD BE IN THE UPPER 70S TO LOWER 80S. DRY WEATHER IS THEN EXPECTED ON SUNDAY...WITH CHANCE FOR THUNDERSTORMS IN FOR MONDAY NIGHT AS A WARM FRONT IS PREDICTED TO LIFT THROUGH THE AREA. A COLD FRONT IS THEN EXPECTED TO APPROACH THE AREA MONDAY NIGHT INTO TUESDAY. TEMPS ARE EXPECTED TO BE NEAR SEASONABLE LEVELS THROUGH THE EXTENDED PERIOD. && .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/... A WARM FRONT S OF LI WILL PASS THRU THE REGION THIS MRNG. A COLD FRONT WILL PASS THIS EVE. SCT-BKN AROUND 1500 FT THIS MRNG. SCT SHWRS AND TSTMS WILL CONTINUE TO DEVELOP AND TRACK NEWD TIL AROUND 15-17Z WHEN DRY AIR WILL FLOW IN FROM THE SW. THIS SHOULD ALSO ALLOW FOR VFR TO DEVELOP QUICKLY. THERE IS A CHC FOR SHWRS AND/OR TSTMS TO DEVELOP THIS EVE RIGHT WITH THE COLD FRONT. THE PROB IS TOO LOW TO INCLUDE IN THE TAFS HOWEVER ATTM. SE FLOW VEERS TO THE SSW THIS MRNG...THEN SW FLOW AFT 15Z. GUST POTENTIAL GREATEST AFT 17Z. WINDS SHIFT TO THE NW TNGT BEHIND THE FRONT. .OUTLOOK FOR 06Z THURSDAY THROUGH SUNDAY... .LATE WED NGT...VFR WITH NW FLOW GENERALLY BLW 10KT. .THU...VFR WITH LGT W FLOW. SEA BREEZES LIKELY. .FRI...VFR WITH WINDS VEERING FROM THE NE TO THE ESE. SEA BREEZES POSSIBLE. .SAT...LOW PRES WILL TRACK S OF THE REGION. IF THE LOW IS CLOSE ENOUGH...MVFR OR LWR POSSIBLE WITH -RA. WINDS GENERALLY N. .SUN...IMPROVEMENT TO VFR. && .MARINE... OCEAN SEAS WILL GRADUALLY BUILD TO MARGINAL SCA THIS AFTERNOON INTO EVE AHEAD OF A COLD FRONT...AND CONTINUE THROUGH TONIGHT. OTHERWISE SUB SCA WINDS/SEAS EXPECTED THROUGH THE PERIOD OUTSIDE OF ANY TSTMS. && .HYDROLOGY... A LARGE AREA OF HEAVY SHOWER AND SCATTERED THUNDERSTORMS WILL PRODUCE RAINFALL RATES OF 1 TO 2 INCHES PER HOUR AS IT TRACKS NORTHEAST THROUGH THE TRI-STATE THROUGH AT LEAST THE FRONT END OF THE MORNING COMMUTE. WITH HIGH TIDE APPROACHING THIS MORNING...MINOR URBAN AND LOW-LYING FLOODING IS EXPECTED...WITH A MODERATE THREAT OF FLASH FLOODING DUE TO TRAINING CONVECTION. A FLASH FLOOD WATCH HAS BEEN ISSUED FOR MOST OF THE TRI-STATE AREA. && .TIDES/COASTAL FLOODING... WITH APPROACHING FULL MOON...TIDAL DEPARTURES OF ONLY 3/4 TO 1 1/2 FT ARE NEEDED FOR MINOR COASTAL FLOODING BENCHMARKS TO BE REACHED DURING THE LATE EVENING/NIGHT HIGH TIDES THE NEXT FEW DAYS. MINOR BENCHMARKS COULD BRIEFLY BE TOUCHED ACROSS THE MOST VULNERABLE AREAS...PARTICULARLY ALONG THE SOUTH SHORE BAYS OF NASSAU COUNTY AND WESTERN LI SOUND...THROUGH THE LATE WEEK PERIOD. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...FLASH FLOOD WATCH UNTIL NOON EDT TODAY FOR CTZ005-006-009-010. NY...FLASH FLOOD WATCH UNTIL NOON EDT TODAY FOR NYZ067>075-078-080- 176>179. NJ...FLASH FLOOD WATCH UNTIL NOON EDT TODAY FOR NJZ002-004-006- 103>108. MARINE...SMALL CRAFT ADVISORY FOR HAZARDOUS SEAS FROM NOON TODAY TO 6 AM EDT THURSDAY FOR ANZ350-353-355. && $$ SYNOPSIS...NV NEAR TERM...NV SHORT TERM...NV LONG TERM...FIG AVIATION...JMC MARINE...FIG/NV HYDROLOGY...NV TIDES/COASTAL FLOODING...NV

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