Area Forecast Discussion
Issued by NWS Upton, NY

Current Version | Previous Version | Text Only | 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. --
000 FXUS61 KOKX 170754 AFDOKX Area Forecast Discussion National Weather Service New York NY 354 AM EDT Tue Apr 17 2018 .SYNOPSIS...
-- Changed Discussion --
A couple of troughs of low pressure will cross the area through Wednesday, as an area of low pressure slowly lifts northeast from Northern New England into the Canadian Maritime Provinces. A low pressure system approaches Wednesday night and passes through the region Thursday. High pressure then gradually builds in through Monday.
-- End Changed Discussion --
&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
-- Changed Discussion --
Weak shortwave ridging transits the area this morning, followed by the second main spoke of the 700-500 hPa closed low moves into the area. Positive vorticity advection ahead of this will produce isolated-scattered showers over the region mainly this afternoon (though cannot completely rule out a shower or two over far W zones late this morning). Today will be breezy (but the winds will not be quite as strong as yesterday) with highs around 5-10 degrees below normal.
-- End Changed Discussion --
&& .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM WEDNESDAY/...
-- Changed Discussion --
The northern stream troughing passes to the east this evening, bringing an end to any isolated-scattered showers from W to E. Lows tonight should be around 5-10 degrees below normal. The closed low lifts to the NE during the day on Wednesday allowing for northern stream shortwave ridging to build in Wednesday afternoon. It is this ridging that will allow sky conditions to become Mostly sunny over the region on Wednesday. Highs Wednesday should be around 5 degrees below normal.
-- End Changed Discussion --
&& .LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/...
-- Changed Discussion --
Models agree that a low pressure system, probably with two low centers for a period, approaches Wednesday night and passes through the region during Thursday. Rain becomes likely by daybreak Thursday for most of the area with most of any rainfall happening from late evening on. Thermal profiles support rain for the most part, but will put in a chance of sleet mixing in across the northernmost zones Wednesday night should the cooler temps aloft shown by ECMWF occur. Rain remains likely through Thursday morning, then chances begin to drop off during the afternoon with the system shifting to our east. There could be some drizzle at times, but won`t add it to the forecast just yet. Leaned toward the cooler side of guidance for high temperatures on Thursday, averaging 7-10 degree below normal. A cyclonic flow remains aloft on Friday, however high pressure at the surface slowly builds in, keeping us dry. Breezy and partly sunny with highs still around 7-10 degrees below normal. High pressure then continues to build in through Monday. Dry weather with high temperatures warming by a couple of degrees each day.
-- End Changed Discussion --
&& .AVIATION /07Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
A cold front moves east of the terminals today, while a surface trough develops over the area this afternoon. For the most part, VFR conditions, though MVFR may linger at KGON til around 08-09Z. Isolated afternoon/evening showers and/or snow showers may be possible, but confidence is low in timing. Any precipitation is more likely to the north and west of NYC. Gusty westerly winds will prevail through today, becoming more frequent and increasing to 25 to possibly 30 KT by midday. ...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: Occasional gusts to 25 kt will be possible through 11Z. The afternoon KJFK haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KLGA TAF Comments: Occasional gusts to 25 kt will be possible through 11Z. The afternoon KLGA haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KEWR TAF Comments: Occasional gusts to 25 kt will be possible through 11Z. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: Occasional gusts to 25 kt will be possible through 11Z. KHPN TAF Comments: Occasional gusts to 25 kt will be possible through 11Z. KISP TAF Comments:Occasional gusts to 25 kt will be possible through 11Z. .OUTLOOK FOR 12Z WEDNESDAY THROUGH SATURDAY... .Wednesday...VFR. W G20 kt possible. .Wednesday night-Thursday...Chance of MVFR and rain. .Thursday night-Friday...MVFR or lower possible in mainly rain with a wintry mix possible to the NW of city terminals late Thursday night/Friday morning. .Saturday...VFR.
-- End Changed Discussion --
&& .MARINE...
-- Changed Discussion --
Gusts on the non-ocean waters have generally fallen to 20 kt or less so have cancelled the remaining Small Craft Advisory (SCA) for early this morning. For today, seas start out 7-11 ft on the coastal ocean waters with some gusts to around 25 kt. These conditions should continue through around midday Wednesday W of Fire Island Inlet and through most, if not all the afternoon E of there. On the non- ocean waters gusts to around 25 kt should develop by early afternoon and continue through at least tonight. As a result have extended the SCA on the coastal ocean waters through midday Wednesday W of Fire Island Inlet and through 6PM Wednesday E of Fire Island Inlet. In addition an SCA for the non-ocean waters was issued from noon today through 6AM Wednesday. At this time, the confidence is not high enough in wind gusts of 25-30 kt continuing into Wednesday on the non-ocean waters to warrant extending the SCA there into Wednesday. Seas will linger up to around 5 ft Wednesday evening before briefly subsiding below advisory criteria late at night. Low pressure passing through with a gusty NW flow behind it will bring some SCA- level gusts to most of the waters on Thursday, and ocean seas will build back up to 5-6 ft at this point. NW gusts could keep the ocean waters at advisory criteria all the way through Friday night, then building high pressure will kick off what appears to be an extended period of tranquil conditions over all waters starting Saturday.
-- End Changed Discussion --
&& .HYDROLOGY...
-- Changed Discussion --
Minor river flooding continues mainly in Bergen and Rockland Counties. All have crested and water levels will continue to recede early this morning. Less than a few hundredths of an inch of rain is expected this afternoon and evening, so no significant hydrologic impacts are expected. Rain amounts below a half inch are expected Wednesday night through Thursday evening with no hydrologic impacts anticipated. Dry weather follows thereafter.
-- End Changed Discussion --
&& .TIDES/COASTAL FLOODING...
-- Changed Discussion --
Water levels are expected to stay below minor flood thresholds for this morning/early afternoon high tide. However, the thresholds for minor coastal flooding could be approached, mainly along the coasts of the back shore bays of S Queens/S Nassau and SW Suffolk counties, during the high tide tonight/early Wednesday morning.
-- End Changed Discussion --
&& .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air. && .OKX WATCHES/WARNINGS/ADVISORIES...
-- Changed Discussion --
CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from noon today to 7 AM EDT Wednesday for ANZ330-335-338-340-345. Small Craft Advisory until 6 PM EDT Wednesday for ANZ350-353. Small Craft Advisory until noon EDT Wednesday for ANZ355.
-- End Changed Discussion --
&& $$ SYNOPSIS...JC/Maloit NEAR TERM...Maloit SHORT TERM...Maloit LONG TERM...JC AVIATION...MD MARINE...JC/Maloit HYDROLOGY...JC/Maloit TIDES/COASTAL FLOODING... EQUIPMENT...

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