Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 121520 AFDOKX Area Forecast Discussion National Weather Service New York NY 1020 AM EST Thu Jan 12 2017 .SYNOPSIS... A cold front approaches from the west today, then crosses the Tri-state tonight. Canadian high pressure builds in from Friday into Saturday as a stationary front sets up south of Long Island over the weekend. High pressure will then build over the area on Monday, followed by a warm frontal passage on Tuesday. Low pressure will track from the Mississippi Valley into Canada during the middle of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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An unseasonably warm day across the region with highs averaging about 20 degrees above normal. Warm front has pushed to the north with only some patchy light rain lingering across the Lower Hudson Valley and interior southern Connecticut, in conjunction with a low-level jet across the region. For the most part, the day will be dry with the best chance for rain well north and west of the NYC metro as a cold front approaches from the west. Based on latest observations, have nudged temperatures up in a few spots. The tricky part today is the amount of sun we see, which at this time is limited by a mid level deck. Some of the high res model data is indicating more clearing near the coast than currently forecast. This would result in warmer temperatures and the likelihood of record highs. Determining the extent of cloud cover in the warm sector can be a challenge, but based on the latest visible imagery, the trend toward more sun looks to be the way to go. SW winds could be a bit gusty near the coast with gusts of 20-25 mph likely with some peak gusts of 30-35mph possible. See the climate section of the AFD for record high details.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM FRIDAY/... Models have been trending towards limited, if any rainfall with the cold frontal passage tonight, so have limited pops to slight chance ahead of the cold front, except for chance pops across far W Orange County. It appears that the low levels dry out fairly quickly and 700-500 hPa vorticity minimum moves in overnight as well. Lows tonight will be 15-20 degrees above normal consistent with a blend of MAV/ECS/MET guidance and NAM 2-meter temperatures. Since the main temperature fall off likely will hold off until after midnight, there is a fairly decent chance that multiple record high minimum temperatures will be set for the calendar day of the 12th as well. See the climate section of the AFD for details. Friday should be dry with zonal flow setting up aloft and downsloping NW boundary layer flow of 15-20kt to help keep things dry. Highs Friday were based on a blend of MET/ECS/MAV guidance, NAM 2-meter temperatures and a mix down from 925-900 hPa per BUFKIT soundings. Highs should be around 5-10 degrees above normal. && .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/... The models have consistently been bringing an arctic airmass across eastern Canada over the weekend, with the cold air bleeding southward into the forecast area. While the surface front will remain somewhere over the Mid-Atlantic, the main question is where the mid level forcing and moisture north of the front will set up. While some of the model runs have kept it south of the area over the last few days, the majority of the data, including the latest runs, bring it through. As a result, have gone with probabilities higher than a pure model blend, close to the SREF and GFS solutions. Accumulations have been kept at less than an inch for now. The main reasons for this are that 1) actual liquid equivalents are still uncertain this far out, and 2) snowfall rates may just be too low, even if it snows for several hours, to result in accumulations. High pressure will build in for Monday, then a warm air advection pattern will set up through Wednesday. This will allow for a light freezing rain threat at the onset, particularly in the Monday night into Tuesday morning period, before changing to all rain for the rest of the forecast period. With the high building eastward over the Atlantic, the freezing rain threat will be primarily across the interior with the coasts warming up quickly. && .AVIATION /15Z THURSDAY THROUGH MONDAY/... A warm front remains north this morning, followed by a cold front night. Generally VFR conditions with areas of MVFR observed this morning. MVFR and IFR remain across Connecticut terminals. Conditions will slowly improve through the remainder of the day. Southwest flow will continue. Occasional gusts are expected especially this afternoon. LLWS is expected at all terminals into the early afternoon, especially NYC metro terminals and east. Some stronger wind gusts than currently forecast are possible through early afternoon. 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: Amendments possible for patchy stratus and occasional wind gusts to 25 kt. KLGA TAF Comments: Amendments possible for patchy stratus and occasional wind gusts to 25 kt. KEWR TAF Comments: Amendments possible for patchy stratus and occasional wind gusts to 25 kt. The afternoon KEWR haze potential forecast is YELLOW...which implies slant range visibility 4-6SM outside of cloud. KTEB TAF Comments: Amendments possible for patchy stratus and occasional wind gusts to 25 kt. KHPN TAF Comments: Timing of improvement uncertain. Amendments possible. Occasional gusts possible. KISP TAF Comments: Amendments possible for patchy stratus and occasional wind gusts to 25 kt. .OUTLOOK FOR 12Z FRIDAY THROUGH MONDAY... .Friday-Friday night...VFR. NW-N winds G20-25KT possible. .Saturday-Saturday night...MVFR or lower conditions are probable with light snow late Saturday/Saturday night. .Sunday...VFR. .Monday...Mainly VFR. && .MARINE... Winds should gust to 25-30kt on the waters around Long Island today, so have expanded the small craft advisory to include all marine zones for today. It appears the winds should diminish below SCA levels tonight, especially over non-ocean zones, with the potential for 25 kt on Friday for all waters. With seas forecast to remain at or above 5 ft over at least a portion of all coastal ocean zones through Friday, have expanded the SCA for these zones through Friday. A broad area of high pressure will keep winds and seas below Small Craft Advisory criteria Friday night through Monday. Return flow will develop on Tuesday, but conditions still look to remain below Small Craft Advisory levels at this time. && .HYDROLOGY... Less than 1/4 of an inch of additional rainfall is expected through this evening, then it should be dry through Friday night. Less than a quarter of an inch of liquid equivalent is forecast over the weekend. There will be chances for rain Monday night through Wednesday. && .CLIMATE... With unseasonably warm temperatures in the forecast for Thursday, record high minimum temperatures and record high temperatures on Thursday may be tied or broken at some climate locations. The following are the record high minimum temperatures and record high temperatures and their respective forecast for Thursday, January 12: Station Record High Forecast High Minimum Minimum NYC............45 (2006)...............48..... LGA............46 (2006)...............47..... JFK............44 (1972)...............47..... EWR............43 (2013)...............46..... ISP............42 (2013)...............46..... BDR............41 (2013*)..............44..... Station Record High Forecast High NYC............64 (1890)...............57...... LGA............60 (1975)...............58...... JFK............60 (1975)...............57...... EWR............61 (1975)...............58...... ISP............58 (1995)...............55...... BDR............52 (1980*)..............55...... *Also in other years. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 PM EST this evening for ANZ330- 335-338-340-345. Small Craft Advisory until 6 PM EST Friday for ANZ350-353-355. && $$ SYNOPSIS...JMC/Maloit/DW NEAR TERM...JMC/Maloit/DW SHORT TERM...Maloit LONG TERM...JMC AVIATION...CB/BC/PW MARINE...JMC/Maloit HYDROLOGY...JMC/Maloit CLIMATE...

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