Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
-- Highlight Changed Discussion --
-- Discussion containing changed information from previous version are highlighted. --
351 FXUS61 KOKX 051529 AFDOKX Area Forecast Discussion National Weather Service New York NY 1029 AM EST Mon Dec 5 2016 .SYNOPSIS...
-- Changed Discussion --
An upper level disturbance and surface trough will pass east by this afternoon. High pressure will build in on Tuesday. Low pressure developing off the Mid Atlantic coast Tuesday evening will pass to the south on Wednesday. A series of cold fronts will then move across from Thursday into Friday. High pressure will build in on Saturday, followed by a warm front passing to the north on Sunday.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL NOON TODAY/...
-- Changed Discussion --
Trough has shifted to eastern CT/Long Island, with light precip to its east. Sfc obs indicate most precip is now rain or a rain/snow mix, though judging from mesonet obs and radar intensity, far northern reaches of Middlesex and western New London in CT may still be seeing all snow and some light accumulation on roads. Farther west, winds have shifted WSW, and there may be partial clearing in NYC metro. Gusts up to 20 mph possible.
-- End Changed Discussion --
&& .SHORT TERM /NOON TODAY THROUGH 6 PM TUESDAY/...
-- Changed Discussion --
High pressure builds in from the west this afternoon, and over the region late tonight into Tuesday morning. This will provide dry weather and clearing skies. By Tuesday afternoon, low pressure will be deepening near Cape Hatteras. The northern fringe of the precipitation shield could reach the area by dark, so low chance PoP has been maintained, although the timing has been slowed from the previous forecast based on the model consensus. A blend of the guidance, which was in good agreement, was used for temperatures through the period.
-- End Changed Discussion --
&& .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/...
-- Changed Discussion --
A progressive upper flow across the lower 48 states will feature a southern branch short wave trough ejecting out ahead of an amplifying upper low over the upper Midwest and south central Canada at the onset of the period. This will allow for surface low pressure to pass off the Mid Atlantic coast Tuesday night into Wednesday, with a mainly rain event for the forecast area. The 00Z GFS continues to be warmer aloft versus the ECMWF/NAM. A compromise of the two solutions results in some snow across far northern sections of the Lower Hudson Valley and interior SW Connecticut, with the potential for 1-2 inches. This will depend on how quickly the cold air erodes Tuesday night with high pressure retreating to the NE. Elsewhere, it will be a rain event with the up to half an inch possible. A building upper ridge along the west coast of North America Wednesday into Thursday will allow the upper trough/low to dig SE across the Great Lakes and into the Northeast states Thursday into Friday. This will result in a series of cold fronts passing through the area and an unseasonably cold air mass moving in for Friday and the weekend. This will also be accompanied by strong NW winds Friday into early Saturday. Outside of some snow flurries or sprinkles it will be primarily dry with scattered clouds, mainly north and west of NYC. Warm advection on Sunday ahead of low pressure moving into the Great Lakes may result in scatted rain/snow showers.
-- End Changed Discussion --
&& .AVIATION /15Z MONDAY THROUGH FRIDAY/...
-- Changed Discussion --
A frontal system exits east of the region with a westerly flow developing into this afternoon. High pressure builds in thereafter through the rest of the TAF period. W-NW winds will become gusty into this afternoon as well with gusts 15-20 kt. Winds diminish going into tonight. Conditions are beginning to improve across the region but there are still some MVFR and localized IFR conditions. Light rain confined to near KGON until this afternoon and it has exited all other terminals. All locations are expected to improve to VFR by 17-19Z. Lower confidence with improvement timing and this could be off by an hour. ...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: MVFR may not materialize before 17Z. An occasional higher gust than forecast is possible this afternoon. KLGA TAF Comments: An occasional higher gust than forecast is possible this afternoon. KEWR TAF Comments: IFR/MVFR end times could be an hour later than forecast. An occasional higher gust than forecast is possible this afternoon. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: MVFR end times could be an hour later than forecast. An occasional higher gust than forecast is possible this afternoon. KHPN TAF Comments: MVFR end times could be an hour later than forecast. An occasional higher gust than forecast is possible this afternoon. KISP TAF Comments: IFR/MVFR end times could be an hour later than forecast. An occasional higher gust than forecast is possible this afternoon. .OUTLOOK FOR 15Z TUESDAY THROUGH FRIDAY... .Tuesday...VFR early, then MVFR possible with a chance of light rain or drizzle. Possible light snow inland late in the day. .Tuesday night-Wednesday...IFR in drizzle and light rain. Possible light snow inland Tuesday night. .Thursday...MVFR possible with a chance of rain. .Friday...VFR. NW winds 15-20 kt, gusts 25-30 kt.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
Northwest flow will pick up this afternoon and evening behind a passing trough, and an SCA is in effect beginning late this afternoon for the ocean and eastern Sound. Elsewhere, winds are too marginal to issue an advisory at this time. Conditions should improve late tonight and Tuesday as high pressure builds over the waters. As low pressure passes to the south Tuesday night into Friday, marginal SCA conditions are possible, with east winds on the ocean waters approaching 20 kt and seas around 5 ft. Thursday into Thursday night another frontal system will move through, with a strong cold passing through Thursday night. Strong/gusty NW winds will develop behind the front, with the potential for gales Friday into Saturday morning on all waters.
-- End Changed Discussion --
&& .HYDROLOGY...
-- Changed Discussion --
No hydrologic impacts are anticipated the next 7 days.
-- End Changed Discussion --
&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from 4 PM this afternoon to 6 AM EST Tuesday for ANZ330-350-353-355. && $$ SYNOPSIS...JMC/DW NEAR TERM...JMC/Goodman/DW SHORT TERM...JMC LONG TERM...DW AVIATION...JM MARINE...JMC/Goodman/DW HYDROLOGY...JMC/DW

USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.