Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 191536 AFDOKX Area Forecast Discussion National Weather Service New York NY 1036 AM EST Sun Nov 19 2017 .SYNOPSIS...
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A strong cold front will move east of the area late this morning with high pressure building in its wake. The high will pass to the south Monday and Tuesday, followed by a cold front on Wednesday. Another area of high pressure will build late week, followed by low pressure moving across on Saturday.
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&& .NEAR TERM /THROUGH 6 PM THIS EVENING/...
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The cold front boundary as of 10am is in the vicinity of Northern New London County in Connecticut extending southward through the vicinity of Montauk NY. This will be well east of the region by this afternoon. Behind it, dry and cold air advection will increase mixing heights with strong westerly flow expected to continue. Expecting the peak gusts in the 10am to 2pm range when the more substantial cooling takes places within the boundary layer. There have already been several locations that have met wind advisory criteria: Newark NJ 51mph at 732am, Kennedy NY 48mph at 806am, Newburgh NY 47mph at 845am, White Plains NY 46mph at 956am. Wind advisory remains in effect until 6pm. Temperatures in the mid 40s to upper 50s will be mostly in the 40s across the whole area and perhaps touch 50 in a few locations by late this afternoon despite more breaks of sunshine.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH MONDAY/... Winds gradually decrease tonight, although will still remain quite gusty with the departing low still strengthening as it lifts into SE Canada and high pres building to the S. All high res guidance indicates that lake effect streamers remain N and W of the area, except perhaps for a few hours this eve in Orange County. Otherwise, partly cloudy skies tonight will give way to mostly sunny conds on Monday. Lows in the upper 20s to mid 30s tonight and highs in the 40s on Monday, although gusty winds will make it feel like its only in the 30s. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... Aloft, models agree early in the period as initial shortwave passes east/northeast. Downstream shortwave will then make fast eastward progress. Here is where some differences arise. Northern stream potent shortwave tracks across the Great Lakes region as it lifts northeast, with most of the energy and associated dynamics lifting well to our north Wednesday. Southern stream trough lags a bit as it moves across the Gulf states. By late Wednesday into Thursday, operational GFS seems to be a deep/strong outlier with regard to closed low around the Gulf states as the trough makes eastward progress. This upper trough weakens over the western Atlantic Thursday, with next shortwave in the northern stream moving eastward toward the northeast by next weekend. At the sfc, high pressure passes to the south Monday and Tuesday. Gusty NW flow will back around the SW as the high tracks east. Thereafter, a cold front passes Wednesday. This front is associated with northern stream shortwave. This looks like the best chance for measurable precipitation, late Tuesday night into Wednesday, chance pops. Waves of low pressure likely develop along the front well to our south in the Wednesday night/Thursday time frame. Again, GFS appears to be an outlier with wave of low pressure developing and passing close enough for measurable precip Thursday. Otherwise, model consensus suggest any precip remains to our southeast as ridge builds to the NW and waves remain far enough to the southeast. Will maintain a dry forecast as a result, leaning toward consensus. However, this will need to be watched. Dry through Friday before the next chance for precip arrives with the shortwave, clipper low Saturday. As for temperatures Monday-Saturday, followed a model/mos blend. Below normal temperatures Monday will warm to slightly above normal Tuesday as WAA occurs behind the high. Behind a cold front Wednesday, normal temps likely fall to below normal Thursday and Friday before rebounding yet again in WAA ahead of the clipper low Saturday. && .AVIATION /15Z SUNDAY THROUGH THURSDAY/...
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High pressure builds in today and tonight. VFR. W-WNW sustained winds 20-25 KT with frequent gusts 34-39 KT and occasional gusts 40-43 KT through around 18z. Sustained winds and gusts drop off by a few KT thereafter this aftn, then subside further tonight. .OUTLOOK FOR 12Z MONDAY THROUGH FRIDAY... .Monday...VFR. W-NW winds G20-30KT. Gusts diminish gradually at night. .Tuesday...Mainly VFR. MVFR possible late Tuesday night in showers. SW winds G15-20KT. .Wednesday...MVFR possible with showers during the day. VFR at night. W-NW winds G15-20KT. .Thursday-Friday...VFR.
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&& .MARINE...
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Mainly gale-force winds with high ocean seas remaining through today. It appears that the best shot of reaching storm force winds is right behind the cold fropa. Buoy 44065 reached 45kts at 1337Z and buoy 44025 reached 43kts at 1410Z so with more mixing expected late this morning will leave storm warning up across eastern waters as gusts are not too far away from meeting storm warning criteria. Gale-force winds will continue into tonight, before gradually weakening to SCA-levels tomorrow. SCA conditions may continue through Tuesday night before winds and seas gradually subside into Wednesday through Friday as high pressure builds across the area.
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&& .HYDROLOGY... A few bands of moderate to locally heavy showers with a strong cold frontal passage this morning should cause no more than local nuisance impacts. Additional rainfall of a few tenths up to 1/4 is expected through late morning, highest amounts east. && .TIDES/COASTAL FLOODING...
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Outside of West Sayville NY which got to minor coastal flooding, tidal locations along the south shore of Long Island have fallen below minor coastal flood benchmarks this morning. Time is now coming down from high tide and as such water levels will fall. No other coastal flooding is expected with westerly flow becoming more dominant.
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&& .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Wind Advisory until 6 PM EST this evening for Cats>012. NY...Wind Advisory until 6 PM EST this evening for NYZ067>075- 078>081-176>179. NJ...Wind Advisory until 6 PM EST this evening for NJZ002-004-006- 103>108. MARINE...Storm Warning until noon EST today for ANZ330-340-345-350-353. Gale Warning until 6 AM EST Monday for ANZ335-338-355.
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&& $$ NEAR TERM...JM AVIATION...JC/MD

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