Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 220159 AFDOKX Area Forecast Discussion National Weather Service New York NY 859 PM EST Wed Feb 21 2018 .SYNOPSIS...
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A slow moving cold front will move through and stall to the south overnight into Thursday. A wave of low pressure will then move across on Friday, followed by a brief respite on Saturday before a more significant frontal system moves across on Sunday. High pressure will follow for Monday through Wednesday.
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&& .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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Updates this evening to reflect current temperature and dew point trends. The cold front is steadily progressing through the area, and will likely be to the south in the next hour or two. Temperatures are very slowly falling in its wake, and will return to climatological normals by tomorrow. Preliminarily, record highs were reached at nearly all of our climatological sites. KISP had a previous record of 63 degrees achieved in 2002, but due to earlier fog and stratus had been slower to rise compared to sites farther west. A few sites have risen nearly 10 degrees following the frontal passage, so we will need to closely monitor for a late record break. New Record Event Reports (RER) have been issued as of 430-450 pm. Notably, the 78 degrees at Central Park is preliminarily the highest temperature recorded in February, breaking the previous record of 75 set on February 24, 1985. Similarly, La Guardia has preliminarily broken a monthly record with a temperature today of 78 degrees, breaking the previous record of 74 set on February 15, 1949. Newark reached a high of 80 degrees, preliminarily breaking the previous monthly record of 76 on February 15, 1949. Temperatures are still fluctuating, so these aforementioned records are still subject to change the next few hours. Truly an incredible pattern overall, more reminiscent of August with a strong subtropical high pressure. 850 mb temperatures for this morning`s 12Z sounding smashed previous records for this time of year, and are closer to the 90th percentile values for a typical summer pattern. 500 mb temperatures appear to be record values as well, and closer to the 90th percentile values summer around -10.5 degrees. Furthermore, per NAEFS ensemble archives, the ridge is of record heights at all levels for this time of year. The summer-like pattern will abruptly come to an end into the overnight hours as a cold front moves south of the area. The line of showers will weaken as it approaches the strong ridge, but at least light showers will remain possible through the night. Temperatures will return to near normal values behind the front - generally in the 30s to 40s.
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&& .SHORT TERM /6 AM THURSDAY MORNING THROUGH THURSDAY NIGHT/...
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A wave will move along the stalled frontal boundary, setting up a period of precipitation from late Thursday morning into Thursday evening. High temperatures may initially be achieved during the morning, followed by gradually lowering temperatures through the day as a surface high builds southeastward. Temperatures aloft will remain somewhat warm in the 925 mb to 700 mb layer. For most locations, the precipitation type will be a cold rain, however for interior areas north and west of NYC there is potential for a wintry mix of sleet, freezing rain and snow around the evening commute. These areas will need to be monitored for the possibility of a winter weather advisory. As colder air filters into the region, afternoon temperatures will be 20 to 30 degrees colder than Wednesday. Daytime highs in the lower to mid 40s will likely occur in the morning, with temperatures falling into the 30s in the afternoon. Temperatures on Thursday night will be a few degrees above normal, in the upper 20s to lower 30s.
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&& .LONG TERM /FRIDAY THROUGH WEDNESDAY/... With strong high pressure passing to the north and resulting cold air damming in place, also warmer air surging in aloft, there could be some sleet and/or freezing rain Fri morning as the next in a series of waves of low pressure rides atop the anomalously strong upper ridge to the south. There could be a brief respite from precip on Saturday as this wave passes east and weak high pressure passes to the north, with skies clearing for a time across southern CT as drier air filters in. Rain chances should again increase Sat night into Sunday with the approach of a warm front in advance of low pressure moving from the Plains toward the upper Great Lakes. An associated trailing cold front should then move through Sunday night, followed by fair and slightly cooler wx Mon through Wed as high pressure builds in. Temps look to be above normal through the period, warmest during the weekend with the approach of the warm front. && .AVIATION /02Z THURSDAY THROUGH MONDAY/...
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A cold front moves across the area this evening. A weak area of low pressure tracks south of the area Thursday. Winds shift to the NW through 03z. Gusts 15 to 20 kt through around 06z in its wake. VFR/MVFR cigs through Thursday morning, with occasional rain showers. Deteriorating conds to Low MVFR/IFR during the late morning/early afternoon Thursday in developing precip. Wintry mix likely for KSWF, spreading south towards KBDR/KHPN by late afternoon. NYC/NJ and LI terminals should be mainly rain, but can`t rule out some IP mixing in late afternoon/evening. .OUTLOOK FOR 00Z FRIDAY THROUGH MONDAY... .Thu Night...MVFR/IFR conds likely. Wintry mix likely for interior terminals. Rain likely for coastal terminals, but possibly transitioning to wintry mix down to the coastal terminals. N-NE winds G15-20KT. .Fri...MVFR/IFR in rain coast, wintry mix interior. .Sat...CHC MVFR in shra. .Sun...MVFR/IFR in rain. S winds G20 KT. .Mon...VFR.
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&& .MARINE... SCA remains in effect until Thursday morning for ocean seas generally around 5 feet east of Fire Island inlet. The cold front moves to the south tonight with seas gradually subsiding below 5 ft into Thursday morning. Sub-SCA conditions are likely Thursday morning before ocean seas build above 5 ft with gusts to 25 kt in the afternoon. These SCA conds should last into Fri morning. An approaching frontal system should also bring SCA conds to the ocean waters from Sunday into early Monday. && .HYDROLOGY... Episodes of light to moderate rainfall from Thursday through Sunday should total about an inch. Hydrologic impacts not expected. && .CLIMATE... Temperatures may approach or break record highs in a few spots Wednesday night. Record High Minimum Temperatures for Wednesday February 21, 2018 Location........Record/Year Newark..............49/2002 Bridgeport..........44/2002 Central Park........50/2002 LaGuardia...........47/2002 JFK.................47/1981 Islip...............45/1996 && .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 EST Thursday for ANZ350-353. && $$ SYNOPSIS...CB/Goodman NEAR TERM...CB/MD SHORT TERM...CB/MD LONG TERM...Goodman AVIATION...BC MARINE...CB/Goodman HYDROLOGY...CB/Goodman CLIMATE... EQUIPMENT...

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