Area Forecast Discussion
Issued by NWS Upton, NY

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167 FXUS61 KOKX 050524 AFDOKX Area Forecast Discussion National Weather Service New York NY 1224 AM EST Mon Dec 5 2016 .SYNOPSIS... High pressure moves offshore overnight as a weak frontal system moves in for Monday morning. High pressure briefly returns Monday night into early Tuesday, before giving way to low pressure passing well south of our region Tuesday night into Wednesday. A rather strong cold front passes through Thursday into Thursday night bringing unseasonably cold weather for Friday into the weekend a well as strong gusty winds. && .NEAR TERM /UNTIL 6 AM THIS MORNING/... With increasing high clouds, ideal radiation cooling will end, and temps should begin to hold steady or rise where radiational cooling took place this evening. Latest NWP suggest forecast is on track with very few changes from previous. PCPN reaches the Hudson around 09Z and rapidly expands east. Have increased POPs to Categorical 80% late tonight into the morning rush in all zones. Snow inland...with some RASN for the CT Coast back to NE NJ. Rain for City and Long Island...some wet flakes may mix in there too. On Long Island with the radiational cooling early tonight, surface temps may be below freezing - so some icing is possible. Have issued a Special Weather Statement (SPS) for the wintry weather during the morning rush. Temps warm quickly early in the morning. && .SHORT TERM /6 AM THIS MORNING THROUGH 6 PM TUESDAY/... Highs in the 45-50 degree range - or about 3-4 degrees warmer than previous as the PCPN is quick to depart. Lingering light rain/DZ and low clouds expected in the morning. All NWP appears very consistent with this system. QPF is around 0.15" - again very consistent. High pressure returns for Monday night. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... A progressive flow will prevail across the continental United States at the beginning of the work week. Dry weather at the start of the extended period will become wet as a southern stream shortwave phases with a northern stream negative trough by 12Z Tuesday. Upper ridging quickly flattens Tuesday. With the progressive flow opted to bring probabilities into the region by Tuesday afternoon, more in line with the faster GFS. The northern and southern stream systems to remain distinct and the area likely will be in a cull. Light rain and possibly drizzle will continue through Wednesday. Another shortwave, moving into the Pacific northwest during Tuesday will rotate through the northern stream trough digging the trough, becoming nearly fully latitudinal during Thursday. Again opted for the faster GFS with the timing of this next system as the flow remains progressive. As the shortwave moves off the northern coast rapid deepening of the low will occur Thursday night into Friday. There is still some uncertainty with the depth of the low and how quickly the low moves off the northeast coast. Again the GFS is faster and deeper with the low. Some of the coldest air of the season is possible behind the cold front with temperatures as much as 10 degrees below normal Friday night into Saturday night. && .AVIATION /06Z MONDAY THROUGH FRIDAY/... A frontal system moves through during the morning, and is followed by high pressure late in the day. Conditions will lower to MVFR by 7-10Z as light precipitation overspreads the area. Expecting primarily rain across the city and coastal terminals of LI. Farther inland, precipitation at KSWF will fall predominately as snow, possibly tapering to light rain or drizzle. Precipitation at KHPN/KBDR and KGON may start as a rain/snow mix before transitioning to all rain. IFR conditions are possible a few hours on either side of 12Z (10- 15Z). VFR returns during the afternoon and through the evening as skies clear. Light E/SE winds shift to the S, then SW by late morning and afternoon at around 10 kt as the system approaches and crosses the area. W/NW winds then prevail late in the day. A gust or two to 15 to 20 kt is possible briefly with the wind shift to the W. NW winds lighten during the evening. .OUTLOOK FOR 06Z TUESDAY THROUGH FRIDAY... .Late tonight...VFR. .Tuesday...VFR early, then MVFR possible with a chance of light rain or drizzle. .Tuesday night-Wednesday...IFR in drizzle and light rain. .Thursday...MVFR possible with a chance of rain. .Friday...VFR. && .MARINE... High pressure gives way to a weak frontal system Monday morning, but winds and seas remain relatively tranquil. Another high builds late and Monday night. High pressure will be exiting the forecast waters Tuesday as a low approaches from the southwest and then moves off the Mid Atlantic coast Tuesday night, remaining well south of the forecast waters Wednesday. Winds and seas are expected to remain below small craft with the exception of the possibility of seas nearing 5 FT on the far outer ocean zones late Tuesday night through Wednesday as the low passes. Thursday into Thursday night another frontal system will move through the forecast waters with a strong cold passing through Thursday night. Strong and gusty northwest winds will develop behind the front with the potential for gale conditions Thursday night into Friday night across all the forecast waters. && .HYDROLOGY... No hydrologic impacts are anticipated the next 7 days. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Tongue NEAR TERM...MET/Tongue/PW SHORT TERM...Tongue/PW LONG TERM...MET AVIATION...PW MARINE...MET/Tongue/PW HYDROLOGY...Tongue

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