Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 160910 AFDOKX Area Forecast Discussion National Weather Service New York NY 510 AM EDT Fri Mar 16 2018 .SYNOPSIS... The region remains between low pressure to northeast across the Canadian Maritimes and high pressure to the west through Saturday. A cold front moves through the region Saturday afternoon. High pressure then builds into early next week, then gives way to a complex low pressure system by mid week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Deep and anomalous upper trough will remain across the western Atlantic today with its closed low over SE Canada/Canadian Maritimes. An unseasonably cold and dry air mass settles over the region today under a deep NW flow. There are no appreciable sources of lift today other than a broad 500 mb shortwave rounding the backside of the upper trough. BUFKIT profiles indicate mixing will occur up to between 800 and 850 mb, especially in the afternoon. Dew points will mix out into the lower and middle teens and it will be quite gusty as well. NW winds will gust 25-35 mph across the region. Mostly sunny skies will begin the day with scattered to at times broken clouds this afternoon. Highs will be in the middle and upper 30s inland and near 40 degrees closer to the coast. These temperatures are about 10 degrees below normal for this time of year.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM SATURDAY/... The shortwave moves offshore tonight, but another closed low dives southward out of Canada towards northern New England tonight and then to the Canadian Maritimes on Saturday. This will send a cold front south Saturday morning and will cross the region in the afternoon. A weak southern stream shortwave moves well south of the region Saturday evening. Dry conditions will continue on Saturday as the atmosphere remains dry under the deep NW flow and with appreciable lift passing well to the NE and to the south. Winds will weaken Friday night but then become gusty again on Saturday although gusts should only be between 20 and 25 mph as boundary layer winds are weaker than on Friday. Low temperatures tonight will range from the lower 20s inland to the middle and upper 20s near the coast. Temperatures continue below normal on Saturday in the lower and middle 40s. && .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... Potential storm is looking likely toward the end of the forecast period, although exact forecast details remain in question. However, global models in remarkable agreement on potent low moving out of the mid west toward the Mid Atlantic coast by Tuesday. Multiple low pressure centers, or one deepening low, slowly move across the western Atlantic, passing just south of the region Wednesday and Thursday. This will set the stage for increasing NE/E winds, and significant precipitation, especially from Tuesday night through Thursday. As for precipitation type this far out, a rain/snow mix near the coast during the daytime is possible, but cannot rule out predominately snow either. Again, details this far out are always a challenge with much dependency on eventual low placement. Accumulating snow more likely during the overnight hours with high pressure located to the north providing ample cold air. Working against an all snow forecast during the daytime hours would be the sun angle this time of the year and potential extended periods of E to ENE winds. Precip intensity will be important as well. Other potential impacts are coastal flooding and strong winds. Prior to this storm, high pressure builds and will result in tranquil weather, generally dry. Through the period, temperatures should average below normal. Model blended guidance followed, which was in line with WPC numbers. && .AVIATION /09Z FRIDAY THROUGH TUESDAY/...
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Low pres will continue to spin over Labrador thru today. High pres will build in from the west Fri ngt with WNW flow into Saturday. VFR thru the taf period. Brisk W to WNW flow will continue thru the taf period. Latest observations continue to indicate that gusts have gone away for now, but should return just after sunrise with tight gradient in place. Therefore wind speeds will pick up once again later this morning, with gusts approaching 30 kts for the late morning and afternoon. Wind speeds will then diminish after 0z. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: KJFK TAF Comments: Arrival of gusts returning this morning may be off by +/- 1 hour. The afternoon KJFK haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KLGA TAF Comments: Arrival of gusts returning this morning may be off by +/- 1 hour. The afternoon KLGA haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KEWR TAF Comments: Arrival of gusts returning this morning may be off by +/- 1 hour. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: Arrival of gusts returning this morning may be off by +/- 1 hour. KHPN TAF Comments: Arrival of gusts returning this morning may be off by +/- 1 hour. KISP TAF Comments: Arrival of gusts returning this morning may be off by +/- 1 hour. .OUTLOOK FOR 00Z SATURDAY THROUGH TUESDAY... .Friday night...VFR with diminishing NW winds. .Saturday...VFR with NW gusts around 20-25KT. .Saturday night-Monday night...VFR. .Tue...Sub-VFR possible, especially during PM in rain/snow. Gusty E-NE flow develops.
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&& .MARINE... A brief minimum in winds continues early this morning, but sustained winds and gusts will increase through the day. Gales are expected by late this morning/early afternoon on the ocean waters east of Fire Island inlet, with small craft conditions elsewhere. Have therefore converted the gale watch to a warning on these waters. Confidence in reaching gales west of Fire Island inlet is lower so will have a small craft advisory with a mention of occasional gusts to 35 kt. The small craft winds will continue through tonight and may extend into a portion of Saturday, especially on eastern LI Sound and the ocean. Ocean seas are likely to remain above 5 ft through tonight and then gradually subside on Saturday. Winds diminish Saturday night and Sunday as high pressure builds, and the pressure gradient relaxes. Seas will respond by subsiding per NWPS and Wave Watch Guidance. Tranquil conditions should continue through Monday night. Then, winds are expected to increase as low pressure begins to develop and move off the Mid Atlantic coast. This could be the beginning of a mid week coastal storm which would impact the waters with increasing winds and building seas Tuesday. && .HYDROLOGY... No significant hydrologic impacts are anticipated through Monday. There is the potential for a period of moderate to heavy precipitation from late Tuesday through Thursday. Predictability of any hydrologic impacts is low at this time. && .TIDES/COASTAL FLOODING... There is the potential for a prolonged period of E-NE flow from Monday Night into Wednesday Night. Tidal departures of generally only 1 to 1 1/2 ft are needed for minor flooding for many locations during this time, and 2 to 3 ft for moderate. Depending on the exact track/strength of a coastal low or lows during this time frame, there is the potential for at least minor coastal impacts, but predictability on any details is low at timeframe. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) is off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 AM EDT Saturday for ANZ335-338- 345. Small Craft Advisory until 6 AM EDT Saturday for ANZ330-340- 355. Gale Warning until 2 AM EDT Saturday for ANZ350-353. && $$ SYNOPSIS...DS/PW NEAR TERM...DS SHORT TERM...DS LONG TERM...PW AVIATION...JE MARINE...DS/PW HYDROLOGY...DS/PW TIDES/COASTAL FLOODING... EQUIPMENT... is the U.S. government's official web portal to all federal, state and local government web resources and services.