Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 281027 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 627 AM EDT SUN JUN 28 2015 .SYNOPSIS... LOW PRESSURE SHIFTS NORTH OF THE AREA TODAY WITH WEAK HIGH PRESSURE FOLLOWING FOR TONIGHT AND MONDAY. WEAKENING LOW PRESSURE SLOWLY APPROACHES ON TUESDAY AND EVENTUALLY MOVES THROUGH ON WEDNESDAY...FOLLOWED BY A COLD FRONT LATE IN THE DAY OR AT NIGHT. HIGH PRESSURE BUILDS IN THROUGH THURSDAY...THEN RETREATS TO THE NORTHEAST INTO FRIDAY. A STORM SYSTEM THEN IMPACTS THE AREA GOING INTO THE FOURTH OF JULY WEEKEND. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... FORECAST UPDATED TO LOWER POPS FOR THE NEXT FEW HOURS AND TO ADD AREAS OF DRIZZLE. BROAD LOW PRESSURE CENTER JUST TO OUR SOUTH THIS MORNING SLOWLY SHIFTS NORTH. MODELS AGREE ON A DIMINISHING MOISTURE DEPTH BY NOON. GENERALLY DIMINISHING CHANCES OF RAIN AS THE MORNING WEARS ON. THUNDERSTORMS SO FAR HAVE BEEN PRIMARILY WELL OFFSHORE WHERE HIGHER CAPE EXISTS...AND THUNDER NEAR THE LOW PRESSURE CENTER HAS SUBSIDED FOR THE PAST SEVERAL HOURS...SO NO MENTION OF THUNDER IN THE GRIDS THIS MORNING. FOR THE AFTERNOON...MODELS SHOW PARTIAL CLEARING FOR GENERALLY THE SOUTHERN HALF OF THE CWA. CAPE SHOULD THEREFORE BE HIGHER THERE...BUT EVEN NORTHERN ZONES SHOULD SEE AN INCREASE IN ELEVATED CAPE. AS MID-LEVEL SHORTWAVE ENERGY APPROACHES FROM THE WEST...ISO/SCT SHOWERS/TSTMS COULD DEVELOP. HIGH TEMPS ARE A BLEND OF NAM AND MAV MOS...A LITTLE BELOW NORMAL. THERE IS A HIGH RISK OF RIP CURRENT DEVELOPMENT ALONG THE OCEAN BEACHES TODAY INTO THIS EVENING. && .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY NIGHT/... THE ATMOSPHERE STABILIZES WITH THE LOSS OF DAYTIME HEATING...AND THE STRONGER MID-LEVEL LIFT FROM THE SHORTWAVE EXITS EAST. AFTER AN ISO/SCT SHOWER/TSTM THIS EVENING...DRY FOR THE OVERNIGHT HOURS. THE FLOW ALOFT TRANSITIONS FROM CYCLONIC TO ZONAL DURING MONDAY. AT THE SAME TIME...MOISTURE REMAINS FAIRLY LIMITED...CONFINED MAINLY WITHIN A 100MB DEPTH CENTERED NEAR 850MB. WITH A STRONG CAPPING INVERSION RIGHT ABOVE THIS...THINKING IS THAT THE CONVECTIVE POTENTIAL IS VERY LIMITED AND WE THEREFORE LIKELY REMAIN DRY. WILL GO WITH A DRY FORECAST. MOISTURE THEN INCREASES AHEAD OF A WEAK LOW APPROACHING FROM THE SW MONDAY NIGHT...BUT IT LOOKS LIKE WE SHOULD GET THROUGH THE NIGHT WITHOUT ANY RAINFALL. TEMPERATURES THROUGH THE SHORT TERM PERIOD ARE A MAV/NAM MOS BLEND. && .LONG TERM /TUESDAY THROUGH SATURDAY/... TUESDAY... WEAK LOW PRESSURE SHIFTS NE ACROSS THE MID ATLANTIC. ANOTHER LOW CENTER WITH A COLD FRONT MOVES ACROSS THE EASTERN GREAT LAKES REGION. THERE COULD BE A SHOWER OR THUNDERSTORM MAINLY OVER THE WESTERN ZONES...BUT THIS SEEMS TO BE MORE ASSOCIATED WITH THE LOW ACROSS THE MID ATLANTIC. A BETTER CHANCE OF RAINFALL WILL ARRIVE TUESDAY NIGHT AS BOTH SYSTEMS MOVE CLOSER. WEDNESDAY-SATURDAY... HAVE CHANCE POPS WEDNESDAY AS A MID-UPPER LEVEL TROUGH AXIS FINISHES LIFTING TO THE NE AND THE COLD FRONT CROSSES THE AREA. WEDNESDAY NIGHT AND THURSDAY SHOULD BE DRY AS SHORTWAVE RIDGING BUILDS OVER THE AREA. THE 12Z ECMWF IS MUCH MORE PROGRESSIVE...AND A BIT STRONGER FOR THE SYSTEM TO IMPACT THE AREA LATE IN THE WEEK...BRINGING PRECIPITATION IN THURSDAY NIGHT/FRIDAY...WHILE THE GFS/GEFS MEAN/CMC/00Z ECMWF WOULD SUGGEST THINGS BEING DRY THROUGH FRIDAY. FOR NOW THIS APPEARS TO BE DUE TO DIFFERENCES IN HANDLING INTERACTION BETWEEN SHORTWAVE RIDGING ROTATING AROUND THE MEAN EASTERN TROUGH AND THE SUB-TROPICAL RIDGE OVER THE ATLANTIC. FOR NOW...KEPT POPS GENERALLY TO SLIGHT CHANCE OR LESS THURSDAY NIGHT - CHANCE FAR SW - THEN CHANCE W/SLIGHT CHANCE POPS E ON FRIDAY. GIVEN SLOWER TIMING OF NON-12Z ECMWF SOLUTIONS...DO HAVE CHANCE POPS IN FRIDAY NIGHT AND SATURDAY THROUGHOUT THE CWA. FOR TEMPERATURES WEDNESDAY-SATURDAY USED A BLEND OF MEX/MEN/EKD/ECE/ECM/WPC GUIDANCE WITH VALUES GENERALLY WITHIN A FEW DEGREES OF EITHER SIDE OF NORMAL FOR THIS TIME OF YEAR. && .AVIATION /12Z SUNDAY THROUGH THURSDAY/... LOW PRESSURE SLOWLY APPROACHES FROM THE SW EARLY THIS MORNING...PASSING OVER THE REGION TODAY. THE LOW THEN LIFTS NORTH OF THE REGION LATE TODAY INTO TONIGHT. RAIN AND IFR CONDS CONTINUES THIS MORNING. LOW CHANCE OF A TSTM THIS MORNING. RAINFALL SHOULD DIMINISH IN INTENSITY/COVERAGE TOWARDS DAYBREAK...BUT IFR CONDITIONS LIKELY PERSIST IN DRIZZLE AND LIGHT RAIN THROUGH THE MORNING. SLOW IMPROVEMENT FROM IFR TO MVFR FROM SW TO NE DURING THE MORNING INTO AFTERNOON. POTENTIAL FOR NORTHERN TERMINALS TO REMAIN IFR/MVFR IN DRIZZLE/SHRA THROUGH THE AFTERNOON. 20 TO 30 KT E WINDS GRADUALLY SUBSIDE TO 10 TO 15 KT TOWARDS DAYBREAK FOR COASTAL TERMINALS...WHILE NE WINDS OF 15 TO 20 KT ACROSS INTERIOR TERMINALS LIKELY BECOMING LIGHT AND VARIABLE. LIGHT AND VARIABLE WINDS LIKELY DEVELOP FOR ALL TERMINALS THIS MORNING AS LOW PRESSURE MOVE OVERHEAD...WITH SW FLOW GRADUALLY DEVELOPING LATE MORNING INTO EARLY AFTERNOON ACROSS NYC METRO TERMINALS AS LOW MOVES JUST TO THE NORTH. SW FLOW LIKELY TAKES LONGER TO DEVELOP ACROSS NORTHERN AND EASTERN TERMINALS AS LOW PRESSURE LINGERS THERE. CONDS LIKELY TO IMPROVE TO VFR FOR MOST TERMINALS LATE TODAY INTO THIS EVENING WITH WSW FLOW...EXCEPT FOR KGON WHICH MAY LINGER WITH IFR/MVFR CONDS THROUGH THIS EVENING. .OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY... .LATE TONIGHT...VFR. DEVELOPING GUSTY WSW WIND. .MON...VFR. .TUE/WED...MAINLY VFR. CHANCE FOR SHOWERS/TSTMS AND MVFR CONDITIONS LATE TUE INTO WED MORNING. .THU...MAINLY VFR. && .MARINE... SCA CONDS ON THE OCEAN WITH JUST A FEW GUSTS TO SCA CRITERIA ON THE SOUND EARLY THIS MORNING. SW WINDS INCREASE LATE TODAY INTO TONIGHT...WITH SCA WINDS GUSTS POSSIBLE ON THE OCEAN AND PERHAPS EASTERN LI SOUND. MARGINAL SCA GUSTS POSSIBLE ON NEARSHORE WATERS ON MONDAY. SEAS WILL REMAIN HIGH THROUGH TONIGHT WITH SE/S SWELLS...THEN GRADUALLY SUBSIDE ON MONDAY. SCA SEAS COULD LINGER ON THE EASTERN OCEAN ZONES INTO MON NIGHT. GUSTS TO SCA LEVELS ARE ARE POSSIBLE ON THE COASTAL OCEAN WATERS TUESDAY AHEAD OF AN APPROACHING FRONTAL SYSTEM...THEN SCA LEVEL SEAS ARE POSSIBLE TUESDAY NIGHT-WEDNESDAY NIGHT. FOR NOW IT APPEARS THE COASTAL OCEAN WATERS SHOULD EXPERIENCE SUB-SCA CONDITIONS ON THURSDAY. && .HYDROLOGY... UP TO ANOTHER THIRD OF RAINFALL IS EXPECTED THROUGH THIS MORNING. THE HIGHER AMOUNTS SHOULD BE ACROSS SE CT. NO SIGNIFICANT HYDROLOGIC IMPACTS ARE EXPECTED. NO WIDESPREAD SIGNIFICANT RAINFALL IS THEN EXPECTED THIS AFTERNOON THROUGH MONDAY NIGHT. WITH PRECIPITABLE WATERS OF 1.5 TO 2 INCHES FORECAST TUESDAY- WEDNESDAY...THERE IS THE THE POTENTIAL FOR LOCALLY HEAVY RAINFALL WITH ANY STRONGER CONVECTION. THIS COULD CAUSE AT LEAST MINOR URBAN/POOR DRAINAGE FLOODING...AND GIVEN EXPECTED ANTECEDENT CONDITIONS...POSSIBLY LOCALIZED FLASH FLOODING. THERE IS A CHANCE FOR SIGNIFICANT WIDESPREAD PRECIPITATION LATE NEXT WEEK AS WELL. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...SMALL CRAFT ADVISORY UNTIL 6 AM EDT MONDAY FOR ANZ350-353-355. && $$ SYNOPSIS...JC/MALOIT NEAR TERM...JC SHORT TERM...JC LONG TERM...JC/MALOIT AVIATION...NV MARINE...JC/MALOIT HYDROLOGY...JC/MALOIT

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