Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 260920 CCA AFDOKX AREA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE NEW YORK NY 508 AM EDT SAT JUL 26 2014 .SYNOPSIS... HIGH PRESSURE WILL MOVE FURTHER OUT TO SEA TODAY AS A WARM FRONT APPROACHES FROM THE SOUTHWEST. THIS FRONT WILL LIFT THROUGH THE AREA SUNDAY MORNING WITH A COLD FRONT APPROACHING SUNDAY NIGHT. A WAVE OF LOW PRESSURE WILL DEVELOP ON THE COLD FRONT...LIFTING THROUGH NEW ENGLAND ON MONDAY AS THE FRONT SLOWLY MOVES ACROSS. HIGH PRESSURE THEN BUILDS IN BEHIND THE FRONT BY THE MIDDLE OF NEXT WEEK. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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HIGH PRES OFF THE MID ATLANTIC COAST WILL CONTINUE EWD TODAY WITH A MEAN TROUGH PERSISTING ALOFT. FAIRLY BENIGN WEATHER IS EXPECTED...WITH THE EXCEPTION OF A FEW ISOLD SHRA/TSTMS THIS AFTN...MAINLY ACROSS THE WESTERN HALF OF THE FORECAST AREA. A DECENT AMOUNT OF CLOUD COVER IS EXPECTED TODAY WITH A WAA REGIME WHICH WILL HOLD HIGH TEMPS RIGHT AROUND NORMAL LEVELS IN THE LOWER TO MID 80S. THERE IS A MODERATE RISK OF RIP CURRENTS ALONG ATLANTIC FACING BEACHES THROUGH THIS EVENING.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/...
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A WARM FRONT APPROACHES TONIGHT AND LIFTS THROUGH SUN MORNING. THE COMBINATION OF A MID LEVEL SHORTWAVE AND THE LEFT EXIT REGION OF A 90KT H250 JET WILL RESULT IN INCREASING CHC`S OF SHRA/TSTMS ACROSS THE AREA LATE TONIGHT INTO SUN MORNING. UNCERTAINTY IN POPS AND SKY BEHIND THE WARM FROPA. IF THERE ARE ANY BREAKS IN THE CLOUDS WE`LL WARM UP FAST AND COULD HIT 90 IN METRO NY/NJ. ANY SUN WILL ALSO RESULT IN DESTABILIZATION DURING THE AFTN AND COULD TRIGGER ADDITIONAL STORMS...SOME OF WHICH COULD REACH SVR LIMITS. MUGGY CONDS WILL BECOME NOTICEABLE AND PERSIST UNTIL THE COLD FRONT PUSHES THROUGH SOMETIME MON NIGHT. THIS IS WHERE THE FORECAST GETS INTERESTING WITH THE FOCUS TURNING TO A WEAKENING CUTOFF LOW DROPPING THROUGH THE UPPER MIDWEST TONIGHT...THE GREAT LAKES SUN AND PIVOTING THROUGH NEW ENGLAND ON MON. SOME OF THE MODEL GUIDANCE IS INDICATING A SECONDARY AREA OF LOW PRES DEVELOPING OVER CENTRAL NJ SUN NIGHT...WHILE OTHERS KEEP IT THE PARENT LOW IN CONTROL FURTHER N AND W. CONSIDERABLE SPREAD REMAINS AMONGST THE GUIDANCE WITH REGARDS TO TIMING AND TRACK OF THE LOW. THE NAM IS THE WORST CASE SCENARIO WITH THE LOW TRACKING NE FROM CENTRAL NJ TO MA WITH 60+KT OF 0-6KM BULK SHEAR (~15KT 0-1KM SHEAR)...APPROX 1K J/KG OF SBCAPE...400-500 M2/S2 OF SFC-1KM HELICITY AND AN LCL BELOW 1K FT AROUND 06Z MON. THIS WOULD BE SUFFICIENT FOR ROTATING STORMS. HOWEVER IF THIS SECONDARY LOW DOES NOT DEVELOP THE MOST SEVERE STORMS SHOULD REMAIN FURTHER N AND W. NEEDLESS TO SAY...STILL SOME FAIRLY BIG UNCERTAINTY IN HOW MUCH OF AN IMPACT THIS WILL BE...BUT SINCE THERE IS THE THREAT FOR SVR WX...HAVE ADDED ENHANCED WORDING TO THE FORECAST SUN AFTN AND NIGHT. PWATS INCREASING TO NEAR 2 INCHES ALSO INDICATE THE POTENTIAL FOR HEAVY RAIN IN ANY THUNDERSTORMS. FRONT IS SLOW TO MOVE ACROSS THE AREA ON MON...AND THE POTENTIAL FOR MORE SHRA/TSTMS WILL CONTINUE MON AFTN.
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&& .LONG TERM /MONDAY NIGHT THROUGH FRIDAY/... UPPER TROUGH/CUTOFF LOW PERSISTS INTO THE MIDDLE OF THE WEEK WITH WEAK HIGH PRES IN CONTROL AT THE SFC. SCHC/CHC SHRA/TSTMS MON NIGHT/TUE AS A RESULT. WEATHER PATTERN BEGINS TO STABILIZE WITH HEIGHTS BUILDING AS THE UPPER LEVEL TROUGH BEGINS TO LIFT NORTH OF THE REGION DURING THE SECOND HALF OF THE WEEK. AT THE SURFACE...HIGH PRESSURE WILL BEGIN TO BUILD IN FROM THE WEST. THE HIGH PRESSURE CONTINUES TO BUILD IN AND THE UPPER LEVEL TROUGH AMPLITUDE CONTINUES TO WEAKEN WITH TIME THROUGH THE REST OF THIS PERIOD. THIS WILL ALLOW FOR A DRY AIRMASS TO ENCOMPASS THE REGION. TEMPERATURES WILL NOT DEVIATE TOO MUCH FROM NORMAL. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... HIGH PRESSURE GIVES WAY TO A SURFACE TROUGH AND WARM FRONT THAT WILL APPROACH FROM THE WEST. MAINLY VFR CONDITIONS ARE EXPECTED. INCREASING MIDDLE AND HIGH LEVEL CLOUDS ARE FORECAST. AN ISOLATED SHOWER OR THUNDERSTORM IS POSSIBLE MAINLY WEST OF NYC TERMINALS THIS AFTERNOON. HOWEVER...ACTIVITY WOULD BE TOO ISOLATED TO INCLUDE IN THE FORECAST AT THIS TIME. BRIEF SUB VFR CONDITIONS ARE POSSIBLE IN ANY SHOWER OR TSTM. SOUTHWEST WINDS 10 KTS OR LESS THIS MORNING WILL BECOME SOUTH 10 TO 15 KTS THIS AFTERNOON. A FEW GUSTS UP TO 20 KT ARE POSSIBLE...HOWEVER GUSTS WILL NOT BE FREQUENT TO INCLUDE IN THE FORECAST. .OUTLOOK FOR 06Z SUN THROUGH WED... .TONIGHT-MON...VFR WITH A CHANCE OF SHRA/TSTMS WITH MVFR OR LOWER POSSIBLE. .TUE-WED...VFR. && .MARINE... SOUTH/SOUTHWEST WINDS ARE FORECAST TODAY AND TONIGHT. THESE WINDS INCREASE SUNDAY AND SUNDAY NIGHT OUT AHEAD OF LOW PRESSURE AND ASSOCIATED COLD FRONT. SEAS BUILD AS A RESULT LATE SUNDAY THROUGH SUNDAY NIGHT AND REMAIN RATHER ROUGH MONDAY. SMALL CRAFT ADVISORY HEADLINES MAY BE NEEDED EVENTUALLY FOR THE SUNDAY NIGHT THROUGH MONDAY TIME FRAME ACROSS THE OCEAN WATERS. WINDS GRADUALLY SHIFT TO THE WEST BEHIND THE SLOW MOVING FRONT LATE MONDAY AND MONDAY NIGHT...AND SPEEDS DIMINISH SOMEWHAT. WEST OR NORTHWEST WINDS CAN BE EXPECTED TUESDAY AND WEDNESDAY. ROUGH SEAS SUBSIDE TUESDAY AND WEDNESDAY. && .HYDROLOGY... UNSETTLED WEATHER WITH SCATTERED TO NUMEROUS SHOWERS/TSTMS ARE FORECAST LATE TONIGHT THROUGH MONDAY. ANY OF THESE STORMS HAVE THE POTENTIAL TO PRODUCE HEAVY DOWNPOURS. SIGNIFICANT UNCERTAINTY STILL EXISTS WITH TIMING AND AMOUNTS THOUGH. IT LOOKS LIKE THE HIGHER POTENTIAL FOR HEAVY RAIN IS SUNDAY AFTN AND SUNDAY NIGHT WITH HIGHER PWATS OF 1.5 TO 2 INCHES ACROSS THE REGION. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$

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