000 FXUS61 KOKX 100512 AFDOKX AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE NEW YORK NY 1212 AM EST WED MAR 10 2010 .SYNOPSIS... HIGH PRESSURE BUILDS INTO THE REGION THROUGH WEDNESDAY...THEN SLOWLY RETREATS NORTHEAST THROUGH THE END OF THE WEEK. A POTENT STORM SYSTEM WILL SLOWLY TRACK WEST FROM THE CENTRAL PLAINS FROM THURSDAY THROUGH SUNDAY...THEN GRADUALLY PULL AWAY TO OUR EAST EARLY NEXT WEEK. HIGH PRESSURE BUILDS IN FROM THE WEST TUESDAY. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... MAINLY CLEAR SKY CONDITIONS AS DEEP LAYERED RIDGING BUILDS INTO THE AREA. ASSOCIATED STRONG SUBSIDENCE WILL PROMOTE BOUNDARY LAYER DECOUPLING...WITH WINDS BECOMING LIGHT AND VARIABLE AS A RESULT. THE COMBINATION OF THE CLEAR SKY CONDITIONS AND LIGHT WINDS WILL RESULT IN EXCELLENT RADIATIONAL COOLING CONDITIONS...WITH LOWS IN THE MID-UPPER 20S ACROSS THE INTERIOR AND PINE BARRENS...AROUND 40 NYC...AND THE LOWER TO MID 30S ELSEWHERE. && .SHORT TERM /6 AM THIS MORNING THROUGH FRIDAY/... MAIN WEATHER PLAYERS IN THE SHORT TERM ARE THE DEEP LAYERED RIDGE OVER THE REGION TO START THE SHORT TERM...AND THE CUTOFF STORM SYSTEM CURRENTLY OVER THE CENTRAL PLAINS. THE GFS HAS A TENDENCY TO WANT TO BRING MOISTURE INTO THE DEEP LAYER RIDGE TOO QUICKLY...SO ITS TIMING HAS BEEN SLOWED DOWN 6-12 HOURS. BASICALLY FOLLOWED A ECMWF/NAM/SREF BLEND IN THE SHORT TERM...WHICH BASICALLY REFLECTS A SLOWED DOWN GFS. SHOULD BE DRY WEDNESDAY...WITH SOME INCREASE IN CLOUD COVER LATE AHEAD OF A LOW-MID LEVEL WARM FRONT. FOR TEMPERATURES WEDNESDAY...ACROSS COASTAL AREAS...OPTED FOR COOLER MET NUMBERS WITH ONSHORE FLOW SETTING UP. ACROSS THE INTERIOR OPTED FOR THE WARMER OF MAV/MET GUIDANCE AS APPROPRIATE AND ADDED ABOUT TWO DEGREES TO REFLECT UNDER PERFORMANCE OF LATE. BASICALLY HIGHS AROUND 50 NEAR THE COAST...AND LOW TO MID 50S ACROSS THE INTERIOR. A SLOWED DOWN GFS AND NAM ISENTROPIC SURFACES FROM I295-I310 SHOW ISENTROPIC LIFT AND CONDENSATION INCREASING WEDNESDAY NIGHT (ON MEAN WESTERLY FLOW - VERY UNUSUAL)...WITH DEEPEST CONDENSATION AFTER MIDNIGHT ASSOCIATED WITH LOW TO MID LEVEL WARM FRONT. AS A RESULT HAVE INTRODUCED SLIGHT CHANCE POPS OVER THE SW 2/3 OF THE CWA AFTER MIDNIGHT FOR LIGHT RAIN...WITH POCKETS OF FREEZING RAIN LATE IN ORANGE COUNTY. GENERALLY BLENDED MAV/MET NUMBERS FOR LOWS...THOUGH DID TWEAK DOWNWARD WITH SNOW COVER OVER FAR NW ZONES (GENERALLY L-M 30S WITH AROUND 40 NYC METRO). ONLY LEFT WITH LOW LEVEL SATURATION ON ISENTROPIC SURFACES THURSDAY...SUPPORTIVE OF LIGHT RAIN OR DRIZZLE (WOULD EXPECT MAINLY DRIZZLE)...WITH POPS INCREASING DURING THE DAY TO MAINLY CHANCE POPS BY LATE AFTERNOON (SLIGHT CHANCE E 1/3). COULD SEE PATCHY LIGHT ZR/ZL IN ORANGE COUNTY TO GET STARTED THURSDAY MORNING. FOR HIGHS THURSDAY...GENERALLY WENT WITH COOLER MAV GUIDANCE (TEMPERATURES GENERALLY AROUND 50). ISENTROPIC SURFACES HAVE DEEPER CONDENSATION THURSDAY NIGHT...IN RESPONSE TO LOW LEVEL FLOW BECOMING SOUTHERLY...AND MID LEVEL FLOW BECOMING SW. SO INCREASE POPS THURSDAY NIGHT TO LIKELY W 1/3 OF THE CWA AND CHANCE ELSEWHERE...WITH A MORE GENERAL RAIN DEVELOPING. FOR LOWS USED A MAV/MET BLEND (UPPER 30S-AROUND 40...WITH SOME LOWER 40S NYC METRO). WITH ISENTROPIC LIFT INCREASING FRIDAY...INCREASE POPS TO LIKELY THROUGHOUT BY AFTERNOON...EXCEPT LOW END CATEGORICAL POPS FAR SW. FOR HIGHS BLENDED A MEX/MEX ENSEMBLE MEAN BLEND WITH NAM 2-METER TEMPERATURES (GENERALLY UPPER 40S TO AROUND 50). GIVEN DAMMING HIGH RETREATING TO THE NW...PREFER ED SLOWER WARM FRONTAL TIMING OF NAM/ECMWF...WITH EASTERLY FLOW CONTINUING AS A RESULT. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... MOISTURE FEED ASSOCIATED WITH AN H5 LOW OVER THE OHIO VALLEY WILL RESULT IN A HEAVY RAIN THREAT...PARTICULARLY SATURDAY AND SATURDAY NIGHT. LIKELY POPS FRIDAY NIGHT THROUGH SUNDAY MORNING...WITH HPC RAINFALL AMOUNTS IN EXCESS OF 3 INCHES OVER NYC AND MODEL QPF VALUES GENERALLY IN THE 2 TO 4 INCH RANGE. HEAVIEST PRECIP AXIS SHIFTS EAST OF THE AREA SUNDAY AFTERNOON...WITH CHANCE POPS PERSISTING INTO MONDAY MORNING. ANY LINGERING SHOWERS WIND DOWN ON MONDAY AS THE UPPER LOW TRANSITS THE AREA...FINALLY SHIFTING TO THE EAST ON TUESDAY. && .AVIATION /05Z WEDNESDAY THROUGH SUNDAY/... VFR THROUGH THE TAF PERIOD. GENERALLY SKC-SCT250 THROUGH LATE THIS MORNING...THEN BKN CIGS AT 250 KFT WILL GRADUALLY LOWER TO 150 KFT BY THIS EVENING. LIGHT AND VARIABLE WINDS THROUGH LATE THIS MORNING...THEN EASTERLY WINDS INCREASE TO 5-7 KT...TURNING SE BY AFTERNOON. OUTLOOK 06Z THURSDAY THROUGH SUNDAY... TONIGHT...VFR THU...SUB-VFR POSSIBLE IN -RA. EASTERLY FLOW INCREASES. THU NIGHT-SAT NIGHT...IFR LIKELY WITH GUSTY SE FLOW. +RA POSSIBLE FRI NIGHT THROUGH SAT NIGHT. SUN...SUB-VFR POSSIBLE. && .MARINE... WITH HIGH PRESSURE BUILDING OVER THE WATERS THROUGH THURSDAY MORNING...WILL HAVE LIGHT WINDS WITH WAVES 2 FT OR LESS. EASTERLY FLOW INCREASES IN STRENGTH FROM THURSDAY AFTERNOON THROUGH FRIDAY...WITH SEAS REACHING SCA LEVELS ON THE OCEAN WATERS ON THURSDAY NIGHT...AND WIND GUSTS TO SCA LEVELS ON ALL BUT THE WESTERN SOUND AND NY HARBOR ON FRIDAY. SCA CONDITIONS LIKELY THROUGH SUNDAY AS A SLOW MOVING STORM SYSTEM IMPACTS THE WATERS. EAST/SOUTHEAST WINDS APPROACHING GALE FORCE ON SATURDAY...WITH WAVE HEIGHTS BUILDING TO THE 10 TO 15 FOOT RANGE ON OCEAN WATERS. VERY ROUGH SEA CONDITIONS PERSISTING ON OCEAN WATERS THROUGH SUNDAY. THE PERSISTENT ONSHORE FLOW COULD PRODUCE COASTAL FLOODING CONCERNS THIS WEEKEND. && .HYDROLOGY... GENERALLY LESS THAN A TENTH OF A RAIN IS EXPECTED THROUGH THURSDAY (WITH TONIGHT AND WEDNESDAY BEING DRY). STEADIER RAIN BEGINS TO DEVELOP THURSDAY NIGHT AND FRIDAY...THEN COULD BECOME HEAVY AT TIMES FRIDAY NIGHT THROUGH SATURDAY NIGHT...WITH DIMINISHING INTENSITY AND COVERAGE SUNDAY INTO MONDAY MORNING AS THE STORM PULLS TO THE EAST. GENERALLY EXPECT 2-3 INCHES OF RAIN FROM THURSDAY NIGHT THROUGH MONDAY MORNING WITH LOCALLY HIGHER AMOUNTS POSSIBLE. THIS...COUPLED WITH SNOW MELT ACROSS NW ZONES...COULD CAUSE FLASH AND RIVER FLOODING CONCERNS...AND DEFINITE MINOR/URBAN FLOODING PROBLEMS OVER THE WEEKEND. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...NONE. NY...NONE. NJ...NONE. MARINE...NONE. && $$ SYNOPSIS...PFM NEAR TERM...PFM SHORT TERM...PFM LONG TERM...MAS AVIATION...MPS MARINE...MAS/PFM HYDROLOGY...PFM