Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
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. --
000 FXUS61 KOKX 211752 AFDOKX Area Forecast Discussion National Weather Service New York NY 1252 PM EST Wed Feb 21 2018 .SYNOPSIS... High pressure over the western Atlantic remains in control today as a slow moving cold front approaches from the west. The cold front moves through tonight, stalling to the south on Thursday. A series of lows and frontal boundaries will impact the area late in the week and through the weekend. High pressure builds early next week. && .NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Visibilities have improved, therefore all dense fog advisories have been allowed to expire. Temperature forecast has been updated to reflect the latest observations. Had to raise high temperatures for western areas by a few degrees as temperatures have jumped under a sunny sky. Temperatures are slow to come up across Long Island and southern Connecticut where stratus remains. The main weather story for today will be the unseasonably warm temperatures aided by an anomalously strong western Atlantic ridge. Better mixing compared to Tuesday will allow temperatures to soar well into the upper 60s and lower 70s away from the immediate coast where readings will be held down in the upper 50s and lower 60s from colder ocean influence. These temperatures are more typical of normal highs in early May. See climate section below for record highs for February 21. A slow moving cold front moves into the region this evening with a shower possible across the NW interior.
-- End Changed Discussion --
&& .SHORT TERM /THURSDAY/... Western Atlantic ridge breaks just enough tonight to allow the cold front to sink south of the region. Lift with the front is weak and have limited PoPs to low chance for the first part of the night. Temperatures will begin a decline as an approx. 1043mb surface high traverses across southeast Canada and begins to build across northern New England. Cold advection will take place tonight with temperatures falling into the upper 30s inland and lower 40s closer to the coast. The cold front stalls across the southern Middle Atlantic on Thursday. The anomalous western Atlantic ridge will still be dominating the weather pattern across the eastern US, but its height field over the northeast is progged to be a bit more suppressed. Weakening shortwave energy will ride along the periphery of the ridge with a weak low pressure developing on the stalled front to our south. Warmer air between 850 and 750 mb will overrun colder air below advecting south from the strong high to the north. This sets up a period of precipitation from late Thursday morning into Thursday evening. Much of the area will see a chilly rain, but there could be some sleet mixing in across the interior in the afternoon where the depth of the colder air is a bit deeper. Will need to watch surface temperatures across the interior as there are some hints that they could come close to freezing in the afternoon. Did not mention freezing rain in the forecast at this time, but it may have to be introduced in subsequent forecasts if colder temperatures look more likely. Temperatures on Thursday will be 20-30 degrees colder than on Wednesday. Daytime highs in the lower to middle 40s will likely occur in the morning, with temperatures falling into the 30s in the afternoon. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... Quite an active pattern is expected through the weekend. Deep SW flow prevails initially with ridge located over the southeast, and trough over the western United States. Sfc frontal boundary weakens as it sags south of the area Thursday night, and lingering light precip temporarily tapers off as high pressure builds to the north. An area of low pressure passes to the north, dragging a warm front, occluded front to the north, through Friday. A cold front quickly follows Friday night. Once again, the front does not make much progress to the south, and the next low pressure center approaches Saturday and Sunday. This is out ahead of downstream trough that ejects out of the west and makes eastward progress across the mid section of the country. The low tracks well to the north, with a warm front passing, followed by a cold front Sunday and Sunday night. High pressure builds Monday and Tuesday. Even though temperatures will be no where near the record readings of the past couple of days, above normal temperatures are anticipated though the period. Highest readings expected this weekend ahead of downstream system when WAA ensues. As for sensible weather, lingering light precip Thursday night will be mainly in the form of rain, but a wintry mix of rain and sleet, or freezing rain and sleet, is expected across the interior. This is true for Friday morning as well if precip moves back in early enough, but all locations should see plain rain when the bulk of the precip arrives ahead of the warm front as temps warm. When precipitation does occur this weekend, it will be in the form of rain. && .AVIATION /18Z WEDNESDAY THROUGH MONDAY/...
-- Changed Discussion --
High pressure today gives way to a cold front tonight. Fog and Stratus continue lift and improve. VFR at the NYC terminals. Terminals east of NYC may take til 20z or 21z to improve. SW around 10 kt. G15-20KT possible this afternoon for the NYC terminals and points west. Winds shift to the NW between 01z and 03z with gusts 15 to 20 kt for NYC/NJ terminals. We should remain VFR with the potential for some pockets of MVFR cigs tonight. More widespread MVFR/IFR conditions return during the morning on Thursday as the next wave of low pressure approaches from the west. 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: Mainly VFR the rest of the afternoon. Chance of MVFR cigs returning after 21Z. Wind shift this evening may be off by an hour or two. KLGA TAF Comments: Mainly VFR the rest of the afternoon. Chance of MVFR cigs returning after 21Z. Wind shift this evening may be off by an hour or two. KEWR TAF Comments: Mainly VFR the rest of the afternoon. Chance of MVFR cigs returning after 21Z. Wind shift this evening may be off by an hour or two. KTEB TAF Comments: Mainly VFR the rest of the afternoon. Chance of MVFR cigs returning after 21Z. Wind shift this evening may be off by an hour or two. KHPN TAF Comments: Mainly VFR the rest of the afternoon. Chance of MVFR cigs returning after 21Z. Wind shift this evening may be off by an hour or two. KISP TAF Comments: Timing of improving flight categories may be off by 1-2 hours. .OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY... .Thu...MVFR/IFR in rain likely. Rain/sleet mix for KSWF in the afternoon and chc sleet/freezing rain at night. N/NE wind G15-20 KT possible. .Fri...MVFR/IFR in rain. chc morning sleet/freezing rain at KSWF. .Sat...CHC MVFR in shra. .Sun...MVFR/IFR in rain. S G20 KT. .Mon...VFR.
-- End Changed Discussion --
&& .MARINE... Dense fog advisory has been extended for the central and eastern ocean and the sound until 17Z due to visibilities near 3/4 miles. The advisory has been cancelled for the harbor and western ocean zones since visibilities have improved. With a persistent southwest flow ocean seas east of Fire Island Inlet remain 5 feet or a little higher through tonight. Marginal SCA gusts are also possible on the ocean this afternoon and evening ahead of a cold front. 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 with ocean seas building above 5 ft and marginal SCA gusts on the ocean in the afternoon. Gusty east/northeast winds Thursday night will lighten as the winds shift to the east/southeast late Thursday night and Friday. A warm front passes as low pressure tracks well to the north, followed by a cold front Friday into Saturday. The front settles nearby, and moves back to the north as a warm front Sunday. Another area of low pressure tracks well to the north late this weekend. Winds pick up during this time, and seas build as well. && .HYDROLOGY... Episodes of light to moderate rainfall are possible Thursday into the weekend. One to two inches of total rainfall is a possibility, but the rainfall accumulations will occur over a long duration. As such, no hydrologic impacts are anticipated at this time. && .CLIMATE... Temperatures may approach or break record highs in a few spots Tuesday and Wednesday. Record Highs for Wednesday February 21, 2018 Location........Record/Year Newark..............69/1953 Bridgeport..........59/2002 Central Park........68/1930 LaGuardia...........68/1953 JFK.................63/2002 Islip...............63/2002 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...
-- Changed Discussion --
CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 AM EST Thursday for ANZ350-353.
-- End Changed Discussion --
&& $$ SYNOPSIS...DS/PW NEAR TERM...CB/DS/PW SHORT TERM...DS LONG TERM...PW AVIATION...BC/JC MARINE...DS/PW HYDROLOGY...DS/PW CLIMATE... EQUIPMENT...

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