Area Forecast Discussion
Issued by NWS Upton, NY

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494 FXUS61 KOKX 272027 AFDOKX Area Forecast Discussion National Weather Service New York NY 427 PM EDT Mon Mar 27 2017 .SYNOPSIS... A nearly stationary front will sink to the south tonight, and remain just south through Tuesday. Weak low pressure will also approach on Tuesday, and pass south Tuesday night. High pressure will build in for Wednesday and Thursday, and shifts offshore Thursday night. A low pressure system will approach from the Central states Thursday night, and impact the region Friday and Saturday. High pressure will return for Sunday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... The front at 20Z bisected the area, running from the lower half of NYC to near Groton CT. As a wave of low pressure develops east of New England this evening, the front should sink to the south, with winds becoming variable and then settling in from the east late. This may bring somewhat drier air in initially, but then with light winds and nearly saturated low levels, dense fog is likely to develop, especially across southern CT and Long Island where a dense fog advy has been issued. Rain approaching from the west ahead of the next weak wave of low pressure may prevent the fog from becoming dense farther west, but this remain uncertain. Lows tonight should range from the mid 40s invof NYC, to the lower 40s most elsewhere, to the upper 30s across most of southern CT. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Rain is likely over the area in the morning as a mid level impulse moves across. There is some elevated instability, enough to enhance rainfall rates but not quite enough for a mention of thunder. Then we should see a relative lull in precip until a weak low moves off the mid Atlantic coast Tue evening and its associated upper trough move across. Once again there could be enough elevated instability to enhance rainfall rates in the evening, especially per the NAM which may be too unstable aloft, so once again did not mention thunder. Also expect fog to redevelop Tue night, though with the air mass not quite as saturated and more of an offshore wind component, dense fog appears less likely. Highs on Tue should be 50-55 from NYC west, and in the upper 40s to near 50s most elsewhere. Lows Tue night should range from 40-45 NYC metro and Long Island, to the upper 30s inland. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Typical spring pattern during this period with a deep closed low emerging into the central US for the midweek...and then slowly translating to the east coast by late week/weekend. The pattern then repeats itself with another deep closed low emerging into the southern plains by early next week. Locally a northern stream trough over the region Wednesday slides east Thursday...with model sensitivity and forecast challenge in the interaction of the Central Plains closed low with a northern stream shortwave over the Ohio Valley/Great lakes Friday before it slide to the east coast Saturday. Appears to be increasing agreement in GEFS/EPS and operational GFS/ECMWF/GEM on the opening shortwave staying detached/far enough south for associated low pressure to approach the Mid Atlantic and track over or just south of the region Fri/Sat. Since this is still 4-5 days away will have to monitor this interaction...as the low track could trend north if the interaction w/ northern stream increases. A low pressure system tracking to the south of the region would spell potential for a period of wintry precip to start...a wind swept rain...and at least minor coastal flood concerns Fri/Sat. Farther north development/intensification would spell lesser potential and duration of wintry precip, rain or coastal flooding. Before then dry and seasonably mild conditions expected Wed and Thu as Canadian high pressure builds into the region. In the wake of low pressure...generally dry and mild conditions expected Sun/Mon with a generally zonal upper flow and PAC airmass overspreading the area. && .AVIATION /20Z MONDAY THROUGH SATURDAY/... A warm front will remain in the vicinity of the terminals this afternoon. Expect low stratus with periods of fog through the forecast period. Cigs may improve to MVFR for a period this afternoon/evening, however overnight, they are expected to fall back to IFR or lower. Visibilities have improved to VFR in most spots. This too should only last through the afternoon/evening, then VSBYs fall back below IFR or less as fog re-develops. There is a chance that VSBYs fall to 1/4 mile or less, however will leave out of the TAFs for now and will monitor through the evening. Winds will remain less than 10 kt through the afternoon and evening, before falling to light and variable overnight. Some locations may even become calm. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Winds generally under 10kt but with low confidence in timing of wind direction change today. Amendments likely for changing flight categories. KLGA TAF Comments: Winds generally under 10kt but with low confidence in timing of wind direction change today. Amendments likely for changing flight categories. KEWR TAF Comments: Winds generally under 10kt but with low confidence in timing of wind direction change today. Amendments likely for changing flight categories. KTEB TAF Comments: Winds generally under 10kt but with low confidence in timing of wind direction change today. Amendments likely for changing flight categories. KHPN TAF Comments: Winds generally under 10kt but with low confidence in timing of wind direction change today. Amendments likely for changing flight categories. KISP TAF Comments: Winds generally under 10kt but with low confidence in timing of wind direction change today. Amendments likely for changing flight categories. .OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY... .Tuesday afternoon-Tue night...IFR likely, LIFR possible Tuesday night with rain/low clouds/fog . .Wednesday...VFR. NW winds G15-20KT. .Thursday...VFR. .Friday-Saturday...Chance of rain with MVFR or lower conditions. E winds G25KT at coastal terminals. && .MARINE... SCA cancelled as seas have fallen below 5 ft. Earlier dense fog advys were also dropped, but reissued for late tonight into Tue morning as vsbys drop below 1 nm with a stationary front sinking just to the south tonight. Northwesterly winds will develop behind the cold front and then increase into Wednesday and Wednesday night as high pressure builds to the north. Minimal SCA conditions are possible across the ocean waters Wednesday night into early Thursday. The next likelihood for SCA and potential gale conditions will be Fri/Sat as a low pressure/frontal system impacts the waters. && .HYDROLOGY... Additional rainfall of at least 1/4 inch and possibly up to 1/2 inch expected through Tue night. No hydrologic concerns anticipated. && .TIDES/COASTAL FLOODING... Astronomical tides will rise through Thu with the new moon. Water levels may come close to minor flood thresholds during high tide cycles Tue Night ahead of approaching low pressure. A greater threat for minor coastal flooding could occur with the Friday night high tide cycle, with the approach of a potential low pressure system. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Dense Fog Advisory from midnight tonight to noon EDT Tuesday for CTZ005>012. NY...Dense Fog Advisory from midnight tonight to noon EDT Tuesday for NYZ078>081. NJ...None. MARINE...Dense Fog Advisory from midnight tonight to noon EDT Tuesday for ANZ330-335-338-340-345-350-353-355. && $$ SYNOPSIS...Goodman/NV NEAR TERM...Goodman SHORT TERM...Goodman LONG TERM...NV AVIATION...BC MARINE...Goodman/NV HYDROLOGY...Goodman/NV

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