AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 638 AM EDT FRI AUG 26 2011 .SYNOPSIS... A COLD FRONT WILL MOVE JUST EAST OF THE AREA THIS MORNING...THEN RETURN ACROSS THE REGION LATER TODAY AS A WARM FRONT. HURRICANE IRENE WILL THEN APPROACH FROM THE SOUTH...WITH ITS IMPACTS LIKELY BEING FELT FROM SATURDAY NIGHT INTO SUNDAY NIGHT. IRENE WILL THEN MOVE WELL OFF TO THE NORTHEAST BY MONDAY...FOLLOWED BY HIGH PRESSURE BUILDING IN THROUGH THE MIDDLE OF NEXT WEEK. PLEASE REFER TO NATIONAL HURRICANE CENTER FORECASTS FOR ADDITIONAL DETAILS. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... 1030Z UPDATE....MINOR UPDATES MADE TO TEMP AND SKY COVER THIS MORNING. PATCHY FOG HAS DEVELOPED OVER THE LOWER HUDSON VALLEY AND INTERIOR CT...WHERE VISIBILITIES IN SOME SPOTS DROPPED TO 1/4 MILE EARLIER THIS MORNING. VISIBILITIES HAVE ALREADY STARTED TO IMPROVE WITH SUNRISE...AND FOG SHOULD DISSIPATE BY AROUND 8 AM. COLD FRONT WILL MOVE ACROSS LONG ISLAND AND INTO THE NEARBY COASTAL WATERS THIS MORNING...THEN STALL AND MOVE BACK UP NORTH SLOWLY THROUGH THE REGION DURING THE DAY AS A WARM FRONT. WITH THE FRONTAL BOUNDARY OVER THE REGION...A FEW SHOWERS OR A THUNDERSTORM MAY DEVELOP THIS AFTERNOON OVER THE SOUTHERN HALF OF THE FORECAST AREA. ACTIVITY IS NOT EXPECTED TO BE WIDESPREAD...AS RELATIVELY LOW LAPSE RATES LIMIT CAPE TO LESS THAN 500 J/KG. ALSO A LOW CHANCE OF ISOLATED ACTIVITY DEVELOPING OVER THE HIGHER TERRAIN IN THE LOWER HUDSON VALLEY...BUT KEPT POPS SILENT AT THIS TIME. NOT MUCH OF A PRESSURE GRADIENT OVER THE REGION TODAY...SO WINDS WILL BE LIGHT THIS MORNING...THEN SOUTHERLY THIS AFTERNOON WITH SEA BREEZE INFLUENCE AND LIGHT SYNOPTIC FLOW BEHIND THE WARM FRONT. TEMPS ARE A BLEND OF MAV/MET GUIDANCE...RANGING FROM THE LOW 80S NEAR THE COAST TO THE MID 80S OVER THE NYC METRO AREA AND THE LOWER HUDSON VALLEY. A FEW SPOTS IN NJ MAY REACH THE UPPER 80S. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... WARM FRONT SLOWLY PUSHES NORTH TONIGHT INTO SATURDAY...AND MOST LIKELY BECOMES STATIONARY NORTH OF THE REGION WHILE IRENE APPROACHES FROM THE SOUTH. STILL MODEL DIFFERENCES REGARDING WHEN THE LEADING PRECIP AHEAD OF IRENE ARRIVES. INCLUDED SLIGHT CHANCE TO CHANCE POPS FRIDAY NIGHT OVER THE REGION FOR POSSIBLE SHOWERS/TSTMS DUE TO IRENE AND POSSIBLE WEAK UPPER LEVEL SHORTWAVE ENERGY. WITH THE REGION IN A WARM TROPICAL AIRMASS OVERNIGHT...LOWS WILL RANGE FROM THE LOW TO MID 60S NORTH OF THE NYC METRO AREA TO THE LOW 70S OVER NYC AND LONG ISLAND. BASED ON 00Z MODELS...PRESSURE GRADIENT SHOULD BE RELATIVELY RELAXED EARLY SATURDAY WITH LIGHT SE WINDS...BUT WINDS WILL BEGIN TO INCREASE LATER IN THE DAY OVER COASTAL PORTIONS OF THE REGION AS IRENE APPROACHES FROM THE SOUTH. POPS INCREASE TO LIKELY DURING THE DAY...AND CATEGORICAL OVER SOUTHERN PORTIONS OF THE REGION BY LATE AFTERNOON. HIGH TEMPS SATURDAY PRIMARILY IN THE UPPER 70S TO LOW 80S. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... LARGE AND DANGEROUS HURRICANE IRENE ON TRACK TO IMPACT THE AREA FROM LATE SATURDAY INTO SUNDAY NIGHT... NO SIGNIFICANT CHANGES IN MODEL GUIDANCE WITH THE TRACK OF HURRICANE IRENE. GIVEN THE SIZE OF IRENE ITS LARGE AND DAMAGING WIND FIELD AND TORRENTIAL RAINS WILL LIKELY ENVELOP MOST OF THE REGION. ALL PREPARATIONS FOR HURRICANE IRENE SHOULD BE COMPLETED BY SATURDAY AFTERNOON...AS OUTER BANDS FROM IRENE SHOULD BEGIN TO IMPACT THE AREA LATE SAT INTO SAT EVENING...WITH CONDITIONS RAPIDLY DETERIORATING IN TORRENTIAL RAIN AND STRENGTHENING WINDS SAT NIGHT. THE WORST CONDITIONS ARE LIKELY LATE SATURDAY NIGHT INTO SUNDAY AFTERNOON WITH DAMAGING WINDS...FLOODING RAINS...AND SIGNIFICANT COASTAL FLOODING. MODELS/NHC FORECAST IN GOOD AGREEMENT WITH TRANSITIONING IRENE PULLING AWAY FROM THE AREA SUNDAY NIGHT WITH RAIN TAPERING OF FROM SW TO NE AND WINDS RAPIDLY DIMINISHING. PLEASE REFER TO NATIONAL HURRICANE CENTER FORECASTS FOR IRENE FOR ADDITIONAL DETAILS. THEREAFTER HIGH PRESSURE BUILDS INTO THE AREA AS UPPER FLOW BECOMES ZONAL THROUGH THURSDAY. AT THE SURFACE HIGH PRESSURE BUILDS INTO THE REGION MONDAY AND REMAINS NEARLY STATIONARY THROUGH THURSDAY. A TROUGH DOES DEVELOP OFF THE COAST WEDNESDAY INTO THURSDAY...HOWEVER THE TROUGH IS EXPECTED TO REMAIN EAST OF THE AREA. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... A COLD FRONT WILL MOVE SOUTH OF LONG ISLAND BY MORNING. WEAK HIGH PRESSURE IN PLACE FOR FRIDAY WITH THE FRONTAL BOUNDARY STALLED TO OUR SOUTH. 09Z OBS INDICATE THAT THE COLD FRONT EXTENDS FROM JUST N OF KGON THROUGH LI SOUND AND NYC TERMINALS. FOG HAD DEVELOPED IN THE WAKE OF THE FRONT AT KSWF AS ANTICIPATED WITH VLIFR CONDS. MVFR TO LOCALLY IFR/LIFR CONDS EARLY THIS MORNING OUTSIDE OF NYC TERMINALS (SEE COMMENTS BELOW) WINDS ALOFT ARE LIGHT TODAY...THEREFORE SEABREEZE DEVELOPMENT IS LIKELY AT COASTAL TERMINALS. ISOLD SHOWER/TSTM POSSIBLE WITH THE FRONT NEARBY OR MAY EVEN BE INITIATED BY SEABREEZE FRONT. WITH SOUTHERLY WINDS RETURNING TODAY LOW LEVEL MOISTURE TO INCREASE. THERE IS THE POSSIBILITY OF STRATUS AND FOG DEVELOPMENT TONIGHT. HAVE INDICATED THIS WITH A SCT CLOUD GROUP FOR NOW. NY METRO ENHANCED AVIATION WEATHER SUPPORT... DETAILED INFORMATION...INCLUDING HOURLY TAF WIND COMPONENT FCSTS CAN BE FOUND AT: HTTP:/WWW.ERH.NOAA.GOV/ZNY/N90 (LOWER CASE) KJFK FCSTER COMMENTS: WIND SHIFT FROM SEABREEZE MAY OCCUR AN HOUR OR TWO LATER THAN CURRENT FORECAST. KLGA FCSTER COMMENTS: SOUND BREEZE WITH WIND DIRECTIONS 040-060 LIKELY BEGINNING AROUND 11Z. WIND SHIFT FROM SEABREEZE MAY OCCUR AN HOUR OR SO LATER THAN CURRENT FORECAST. KEWR FCSTER COMMENTS: MODERATE CONFIDENCE OF SEABREEZE REACHING THE AIRFIELD. COULD BE A FEW HOURS LATER THAN FORECAST. THE AFTERNOON KEWR HAZE POTENTIAL FORECAST IS YELLOW...WHICH IMPLIES SLANT RANGE VISIBILITY 4-6SM OUTSIDE OF CLOUD. KTEB FCSTER COMMENTS: MVFR FOG POSSIBLE THROUGH 13Z OR SO. MODERATE CONFIDENCE OF SEABREEZE REACHING THE AIRFIELD. COULD BE A FEW HOURS LATER THAN FORECAST. KHPN FCSTER COMMENTS: LIFR OR VLIFR CONDS POSSIBLE BETWEEN 10Z AND 13Z. VFR RETURNS SHORTLY THEREAFTER. KISP FCSTER COMMENTS: MVFR OR IFR CONDS POSSIBLE THROUGH 13Z OR SO. VFR THEREAFTER. TIMING OF WIND SHIFT FROM SEABREEZE MAY BE AN HOUR OR TWO LATER THAN FORECAST. OUTLOOK FOR 06Z SATURDAY THROUGH TUESDAY... FRI NIGHT...VFR TO START...THEN IFR OR LOWER POSSIBLE OVERNIGHT. CHANCES FOR RAIN BEING TO INCREASE DURING THE SECOND HALF OF THE NIGHT. SAT...IFR POSSIBLE EARLY...THEN MVFR WITH RAIN IMPACTS LATER IN THE DAY IN ADVANCE OF TC IRENE. LOCALLY IFR CONDS IN HEAVY RAIN POSSIBLE. SUN...SUB-VFR LIKELY WITH HEAVY RAIN AND STRONG GUSTY WINDS DUE TO TC IRENE. MON...VFR. GUSTY WINDS POSSIBLE EARLY. TUE...VFR LIKELY. PLEASE REFER TO THE NATIONAL HURRICANE CENTER FORECASTS FOR THE LATEST DETAILS ON IRENE. && .MARINE... A MODERATE S FLOW COMBINED WITH INCREASING SOUTHERLY SWELL FROM HURRICANE IRENE WILL PRODUCE SCA SEAS ON THE OCEAN WATERS TODAY. WINDS WILL SLACKEN TODAY BEHIND A COLD FRONTAL PASSAGE AND WITH A WEAK PRESSURE GRADIENT OVER THE AREA. SEAS CONTINUE TO INCREASE ON THE OCEAN FROM FRIDAY NIGHT INTO SATURDAY AS SWELLS FROM HURRICANE IRENE INCREASE. CONDITIONS ON THE WATERS WILL RAPIDLY DETERIORATE SAT NIGHT...WITH HURRICANE CONDITIONS POSSIBLE LATE SATURDAY NIGHT THROUGH SUNDAY. POTENTIAL FOR SEAS TO BUILD TO 20 TO 30 FT RANGE ON THE OCEAN...AND 10+ FT WAVES ON LI SOUND DEPENDING ON EXACT TRACK. BASED ON LATEST FORECAST TRACK...WINDS SHOULD DIMINISH FAIRLY RAPIDLY SUNDAY NIGHT AS IRENE PULLS AWAY. OCEAN SEAS WILL BE SLOWER TO SUBSIDE...LIKELY REMAIN ROUGH THROUGH MONDAY IN RESIDUAL SWELLS. SEAS SHOULD THEN GRADUALLY SUBSIDE BELOW SMALL CRAFT ADVISORY MONDAY NIGHT INTO TUESDAY AS HIGH PRESSURE BUILDS OVER THE WATERS AND SUBS SCA WINDS PREVAIL. && .HYDROLOGY... THERE IS INCREASING CONFIDENCE IN TORRENTIAL RAINS DEVELOPING OVER THE REGION SAT NIGHT AND CONTINUING THROUGH MUCH OF SUNDAY BASED ON THE NHC FORECAST TRACK FOR HURRICANE IRENE. A PRECURSOR LOCALLY HEAVY RAINFALL EVENT COULD TAKE PLACE SAT IN THE VICINITY OF A NORTHWARD DRIFTING REMNANT FRONT WELL BEFORE THE ARRIVAL OF VERY HEAVY RAINS ASSOCIATED WITH THE HURRICANE ITSELF. STORM TOTAL QPF OF 5 TO 10 INCHES IS LIKELY FOR MUCH OF THE REGION...WITH LOCALLY UP TO 15 INCHES DEPENDING ON THE EXACT TRACK OF THE STORM. BASED ON ALREADY WET ANTECEDENT CONDITIONS...IF THESE RAINFALL AMOUNTS OCCUR...MODERATE TO MAJOR RIVER FLOODING IS LIKELY AT NUMEROUS SITES ACROSS OUR TRI-STATE RIVER BASINS. IN ADDITION...SIGNIFICANT AND WIDESPREAD URBAN AND POOR DRAINAGE FLOODING WILL ALSO BE AN ISSUE. A FLOOD WATCH WILL BE ISSUED TO ADDRESS THIS THREAT. PLEASE REFER TO NATIONAL HURRICANE CENTER FORECASTS FOR FURTHER DETAILS...AND BE PREPARED FOR THE LIKELIHOOD OF SIGNIFICANT INLAND FLOODING AS TROPICAL RAINS OVERSPREAD THE AREA. && .TIDES/COASTAL FLOODING... DEPENDING ON THE EXACT TRACK...INTENSITY AND TIMING OF HURRICANE IRENE...THERE IS POTENTIAL FOR MODERATE TO MAJOR COASTAL FLOODING DAMAGE IF THE GREATEST SURGE COINCIDES WITH THE TIMES OF HIGH TIDES SUN MORNING AND/OR SUNDAY EVENING. THIS SURGE WILL BE EXACERBATED BY BATTERING SURF. IN ADDITION...INCREASINGLY LARGE SWELLS ARRIVING FROM HURRICANE IRENE WILL CREATE HIGH SURF AND SIGNIFICANT BEACH EROSION AS EARLY AS SATURDAY AND CONTINUING INTO MONDAY. DANGEROUS RIP CURRENTS WILL CONTINUE THROUGH THIS WEEKEND...LIKELY INTO MONDAY. PLEASE REFER TO NATIONAL HURRICANE CENTER FORECASTS AND ADVISORIES...AND BE PREPARED FOR SIGNIFICANT COASTAL IMPACTS SHOULD HURRICANE IRENE DIRECTLY IMPACT THE REGION. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...FLOOD WATCH FROM SATURDAY EVENING THROUGH LATE SUNDAY NIGHT FOR CTZ005>012. HURRICANE WATCH FOR CTZ005>012. NY...FLOOD WATCH FROM SATURDAY EVENING THROUGH LATE SUNDAY NIGHT FOR NYZ067>075-078>081-176>179. HURRICANE WATCH FOR NYZ068>075-078>081-176>179. TROPICAL STORM WATCH FOR NYZ067. NJ...FLOOD WATCH FROM SATURDAY EVENING THROUGH LATE SUNDAY NIGHT FOR NJZ002-004-006-103>108. HURRICANE WATCH FOR NJZ004-006-103>108. TROPICAL STORM WATCH FOR NJZ002. MARINE...HURRICANE WATCH FOR ANZ330-335-338-340-345-350-353-355. SMALL CRAFT ADVISORY UNTIL 6 PM EDT SATURDAY FOR ANZ350-353- 355. && $$ SYNOPSIS...KCS