Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 261723 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 123 PM EDT SUN APR 26 2015 .SYNOPSIS... LOW PRESSURE OVER THE CANADIAN MARITIMES AND ANOTHER LOW MOVING OFF THE MID ATLANTIC COAST TODAY WILL CONSOLIDATE INTO A BROAD AREA OF LOW PRESSURE OVER THE WESTERN ATLANTIC MONDAY INTO TUESDAY. A LARGE AREA OF HIGH PRESSURE WILL BUILD EAST ACROSS THE REGION BY MID WEEK. LOW PRESSURE MOVING OFF THE SOUTHEAST COAST MAY IMPACT THE REGION ON THURSDAY. && .NEAR TERM /THROUGH TONIGHT/... DRY WEATHER SO FAR BUT DIURNAL CU HAVE EXPANDED AND INCREASED IN COVERAGE ACROSS THE REGION. SEA BREEZES HAVE FORMED ALONG THE COASTLINES. TEMPERATURES...DEWPOINTS...WINDS...AND CLOUD COVERAGE PARAMETERS WERE ADJUSTED TO BETTER MATCH THE OBSERVED TRENDS. MAX TEMPERATURE FORECAST STILL LOOKS PRETTY MUCH ON TRACK...OVERALL UPPER 50 TO NEAR 60. STILL CANNOT RULE OUT A BRIEF LIGHT SHOWER...MOSTLY ACROSS THE INTERIOR FOR LATE AFTERNOON INTO THE EVENING. WATER VAPOR INDICATES A LARGE CYCLONIC CIRCULATION OVER ERN CANADA DRIFTING WWD. THE MODELS INDICATE THIS TREND WILL CONTINUE TODAY. SHRTWV ENERGY ASSOCIATED WITH THE SYS HAS WEAKENED SIGNIFICANTLY IN THE MODELS. AS A RESULT...QPF IS MINIMAL IN THE PROGS. THE NAM INDICATES MAYBE A FEW SPRINKLES OR VERY LIGHT SHOWERS SPREADING SWD DOWN THE HUDSON VALLEY INTO THE EVE BEFORE FIZZLING OVER THE CWA. OTHERWISE THE DATA SUGGESTS DRY. WENT WITH A DRY FCST AFT 1Z WITH LOSS OF SFC BASED INSTABILITY. GUIDANCE WAS IN GOOD AGREEMENT WRT TEMPS...SO WENT WITH A BLEND. MIXING ABV H85 PER MODEL SOUNDINGS...AND THE TEMP CAP LOOKS TO BE INVOF THE DEVELOPING CLOUD DECK. && .SHORT TERM /MONDAY THROUGH WEDNESDAY NIGHT/... SCT SHWRS APPEAR ON TRACK FOR MON AS THE UPR LOW CENTER MAKES ITS CLOSEST APPROACH AND SLIDES DOWN THE ERN NEW ENGLAND COASTLINE. THE MOST ROBUST ACTIVITY ERN ZONES CLOSER TO THE UPR SUPPORT. THE NAM ONLY INDICATES 50-150 J/KG SBCAPE...WITH THE HIGHEST VALUES INVOF THE RI BORDER. RI INTO ERN MA GETS ABV 200 J/KG...IF THIS ENTIRE SYS SHIFTS SLIGHTLY WWD...THE ISOLD TSTM THREAT COULD EXTEND INTO THE CWA. FOR NOW...TSTMS NOT INCLUDED IN THE FCST. TEMPS AROUND 0C AT H85...BUT DEEP MIXING TO AROUND H8 WILL KEEP HIGHS ONLY A FEW DEGREES BLW CLIMO. THE RIBBON OF SHRTWV ENERGY THEN SLIDES EWD MON NGT AND TUE. AS A RESULT...GRADUALLY END PCPN CHCS MON NGT AND KEPT TUE DRY. TEMPS APPROACH CLIMO WITH HEIGHTS INCREASING AND DEEP MIXING CONTINUES ON NW FLOW. UPR RIDGING THEN BUILDS IN ON WED. A DRY FCST WED AND WED NGT. THE WARMING TREND CONTINUES AS THE UPR RIDGE AXIS BUILDS IN. TEMPS SHOULD REACH INTO AT LEAST THE UPR 60S ALONG AND W OF THE HUDSON...BUT THE WEAK PRES FIELD SHOULD RESULT IN FAIRLY DEEP PENETRATION OF SEA BREEZE FLOW. && .LONG TERM /THURSDAY THROUGH SATURDAY/... THE GFS HAS TRENDED TOWARDS THE ECMWF NOTION OF DEEPENING LOW PRES SOMEWHERE NEAR HATTERAS THU...THEN TRACKING NEWD OVER THE ATLC FRI AND INTO THE N ATLC SAT. THE MODEL CONSENSUS IN STILL THAT THE SYS MISSES US...WITH PERHAPS SOME SHWRS IN THE WAA PATTERN ON THU. MAINTAINED THE LOW POPS IN THE FCST THRU THE PERIOD...BUT CHANGES WX TYPE TO RAIN FRI-SAT AS IT APPEARS THE FOCUS WILL BE ON THE NRN EXTENT OF THE PCPN SHIELD AS OPPOSED TO THE DEVELOPMENT OF SHOWERY PCPN ATTM. TEMPS A BLEND OF PREV AND THE GMOS25. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... A WEAK TROF SETS UP ACROSS THE AREA THIS AFTERNOON. HIGH PRESSURE THEN RE-ESTABLISHES ITSELF TONIGHT. BKN INSTABILITY THIS AFT/EVE. ISOLATED SHRA ACTIVITY THIS AFT/EVE...PARTICULARLY CT TERMINALS. WEAK N/NE FLOW UNDER THERMAL TROUGH WITH WINDS VEERING TO S FOR COASTAL TERMINALS AND BACKING NW FOR WESTERN TERMINALS. SEABREEZE ALONG THE CT/NYC/LI COAST WILL CONTINUE TO WORK N THROUGH THE AFTERNOON. INCREASING PROBABILITY FOR KLGA TO SEABREEZE LATE THIS AFTERNOON...AND MODERATE PROB AT KEWR. WINDS WEAKEN AND BECOME NW THIS EVENING AS HIGH PRESSURE STRENGTHENS...WITH STRATO-CU GRADUALLY SCATTERING OVERNIGHT. BKN 040-060 STRATO-CU DEVELOPMENT EXPECTED MONDAY WITH SCATTERED SHOWER DEVELOPMENT IN THE AFT/EVE. BRIEF MVFR POSSIBLE WITH SHRA IN THE AFTERNOON. LOW PROB FOR ISOLATED TSRA...MAINLY KGON. NW WINDS 10 TO 15 KT WITH GUSTS TO 20 KT MON AFTERNOON. WINDS GENERALLY RIGHT OF 310 TRUE. .OUTLOOK FOR 18Z MONDAY THROUGH FRI... .LATE MON-MON NIGHT...POSSIBLE MVFR WITH SHOWERS. .TUE-WED NIGHT...VFR. ISOLATED SHRA POSSIBLE TUE. .THU...VFR. LOW PROB FOR -SHRA. .FRI...LOW PROB FOR COASTAL STORM. && .MARINE... SUB-SCA CONDITIONS ARE FORECAST THROUGH THE MIDDLE OF NEXT WEEK AS A LARGE AREA OF HIGH PRESSURE OVER THE MID SECTION OF THE COUNTRY WORKS SLOWLY EAST. MARGINAL GUSTS ARE POSSIBLE MON NIGHT INTO TUE ON THE OCEAN WATERS AS A NLY FLOW STRENGTHENS BETWEEN A BROAD AREA OF LOW PRESSURE OVER THE WESTERN ATLANTIC AND HIGH PRESSURE BUILDING IN FROM THE WEST. LOW PRESSURE MOVING OFF THE SE COAST THU MAY IMPACT THE WATERS WITH A STRENGTHENING EASTERLY FLOW AND BUILDING SEAS. && .HYDROLOGY... SIGNIFICANT PRECIPITATION IS NOT EXPECTED THROUGH NEXT WEEK. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...JMC NEAR TERM...JMC/JM SHORT TERM...JMC LONG TERM...JMC AVIATION...NV MARINE...DW HYDROLOGY...JMC

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