Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 100912 AFDOKX Area Forecast Discussion National Weather Service New York NY 412 AM EST Sun Dec 10 2017 .SYNOPSIS...
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Deepening low pressure tracks up into the Canadian Maritimes today, while high pressure builds in from the southwest through Monday. A clipper low then tracks across the Great Lakes Monday night, sending a warm front across the area Tuesday morning followed by a strong cold front in the afternoon. Another low may impact the area from late Thursday into Friday, followed by high pressure on Saturday.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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A highly amplified flow will continue into the upcoming week with a ridge out west and a another amplifying trough east of the Mississippi River Valley. Prior to that time, strong jet energy and a shortwave trough lift NE of the New England coast this morning. Deepening surface low pressure tracks across the Canadian maritimes, while weak high pressure noses in from the southwest. This will result in a gusty west flow today with skies clearing from west to east this morning. Highs will top out in the upper 30s to around 40, which is about 5 degrees below normal.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/...
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Another mid level shortwave trough approaches tonight with warm advection and a chance of flurries overnight. A more robust system the drops southeast out of the Upper Midwest on Monday, tracking across the Great Lakes Monday night, then to the north of the area on Tuesday. It was this very system a few days back that raised concerns for coastal low development and a potential winter storm. Models are all in good agreement that this development occurs late enough to spare the region a significant winter storm. The 00Z GFS develops a triple point low in close vicinity to the area Tuesday morning, while the model consensus is just north of the area near the southern New England coast. This scenario with warm advection and onshore flow would result in a mainly rain event for the coast, with a period of snow across the interior late Monday night into Tuesday morning before changing over to rain. There is the potential for 1 to 3 inches of wet snow across interior NE NJ, the Lower Hudson Valley, and interior southern Connecticut. Temperatures will remain at or just below normal tonight into Monday. Temperatures then hold steady or gradually rise Monday night ahead of an approaching warm front and SE flow. Strong cold advection then ensues behind the cold front late Tuesday afternoon into Tuesday night. Temperatures will fall into 20s Tuesday night, and rise little if any on Wednesday.
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&& .LONG TERM /WEDNESDAY THROUGH SATURDAY/...
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Most locations will not break freezing o Wednesday. This along with winds gusting up to 40 mph will result in wind chills in the single digits and teens, and perhaps below zero across the interior Wednesday night. Some uncertainty exists on the timing and track of one or more northern stream disturbances for late week. Models generally agree on a system passing through late Thu night into Friday as an amplifying long wave upper trough to the west approaches and passes through. As a result have broad-brushed low chance PoP from Thu night into Friday. Temps should be cold enough for precip with these potential systems to be mainly snow. After these systems pass, zonal flow should return, with temps returning closer to average, if not by Sat, then by early next week before the mean trough in the East reloads and colder air returns mid next week.
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&& .AVIATION /09Z SUNDAY THROUGH THURSDAY/...
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Low pressure tracks into the Canadian Maritimes this morning. VFR conditions for all but KSWF, where IFR-MVFR may persist through about 12Z. After 15Z, a SCT-BKN deck will rebuild around 030-040. Winds back to the west-northwest this morning, then west during the day with gusts around 20 KT. Winds subside after 00Z Monday. .OUTLOOK FOR 06Z MONDAY THROUGH THURSDAY... .Late tonight...VFR. West winds less than 10 kt. .Monday...VFR. Iso flurries in the morning. .Tuesday...MVFR or lower with early morning mixed pcpn, changing to rain by mid-morning. Dry aftn with CHC VFR by late. .Wednesday...VFR, chc MVFR/-shsn east of city terminals. NW gusts 30- 35 kt. .Thursday...VFR
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&& .MARINE...
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SCA conditions will persist through today as westerly winds strengthen...allowing gusts to 25-30 kt on all waters. Seas will remain elevated across the ocean waters through Monday, and may briefly subside Monday night as high pressure moves through. Strengthening flow ahead of a deepening low pressure system will allow for seas to build once again on Tuesday, with SCA-level conditions on at least the ocean waters. As the low departs, the pressure gradient strengthens as high pressure builds to the west, with gale-force winds possible Wednesday into Wednesday night. Gales may linger on the eastern ocean waters into Thursday morning, but otherwise SCA-levels will persist through the day. Seas briefly subside again by late week.
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&& .HYDROLOGY...
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No significant hydrologic impacts expected.
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&& .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) is off the air for an extended period of time. See our headline news on the web at: http:/weather.gov/nyc The Riverhead NOAA Weather Radio Station WXM-80 (162.475 MHz) is currently out of service. NWS technicians are working with Verizon to restore service. An estimated time of return to service is not currently known. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ335- 338-345. Small Craft Advisory until 6 AM EST Monday for ANZ330-340. Small Craft Advisory until 6 PM EST Monday for ANZ350-353-355.
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&& $$ SYNOPSIS...DW NEAR TERM...DW SHORT TERM...DW LONG TERM...Goodman/DW AVIATION...MD MARINE...MD HYDROLOGY...DW EQUIPMENT...//

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