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 180007 AFDOKX Area Forecast Discussion National Weather Service New York NY 807 PM EDT Tue Jul 17 2018 .SYNOPSIS... A cold front will move across the area this evening. High pressure will then build across the region Wednesday through Thursday, sliding offshore Friday night into Saturday. A frontal system approaches Saturday night into Sunday with a prolonged period of unsettled weather possible into early next week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Adjusted probabilities to attempt to capture the band of pre frontal showers and isolated thunderstorms exiting the eastern zones at 23Z, and the line of showers and thunderstorms ahead of the cold front, moving into western Orange county. Winds across much of the area have shifted back to the south ahead of the cold front, and then shift back to the NW behind the cold front. The actual cold front moves through this evening across western portions of the Lower Hudson Valley, and then far eastern areas by early morning. A high risk of rip currents continues for the ocean beaches into this evening. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Drier and less humid conditions are tap for Wednesday with a northerly flow and a highs in the 80s. Readings will be a few degree above normal but it will feel much more comfortable as dewpoints drop into the 50s. Lows Wednesday night will be near seasonable levels. Aloft, the upper trough axis swings across the area Wednesday into Wednesday night. Lack of moisture though will keep the region dry. There is a moderate risk of rip currents on Wednesday due to a 3 to 4 ft southerly swell and offshore flow maintaining waves around 3 ft in the surf zone. && .LONG TERM /THURSDAY THROUGH TUESDAY/... The long term period will begin will tranquil conditions as middle and upper trough axis moves offshore. Ridging will build aloft Thursday into Friday along with surface high pressure. Near seasonable temperatures are expected on Thursday and Friday. There is good agreement among the models for the ridge to move offshore late Friday into the weekend as a shortwave digs and amplifies across the eastern states. This could potentially set the stage for an unsettled period into early next week. As the surface high moves offshore on Saturday, there will likely be enough surface ridging to keep the area dry. However, a frontal system associated with the shortwave/upper trough will approach the region on Saturday. The latest models show the warm front approaching Saturday night into Sunday morning. There continues to be indications of a wave forming on the warm front as a strong vort max moves up the coast. This will need to be watched for any early morning strong thunderstorms with the approaching warm front. Otherwise, showers and thunderstorm chances continue into early next week overall as the frontal system lingers nearby with a blocking ridge over the Atlantic. Temperatures this weekend and into early next week will ultimately be determined by how much clouds and precipitation occur, but should be near or slightly above normal. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... A cold front will move across the region late tonight. There is still the more narrow line of showers and embedded thunderstorms that will move in this evening. Some more showers have developed ahead of this line. Some brief IFR/MVFR conditions will be possible with these showers with otherwise mainly VFR conditions in place. Higher chances of thunder for KSWF with lower chances elsewhere. Winds generally variable in direction inland and more S-SW towards the coast near 10 kts or less. Some uncertainty with this wind direction this evening before the cold front moves across late. That will enable a more consistent NW-N flow less than 10 kt to develop after the front moves across. VFR conditions and north flow persists into Wednesday. 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: A chance of brief MVFR/IFR conditions this evening. Timing of wind shift to NW could be 1-3 hrs off from forecast. KLGA TAF Comments: A chance of brief MVFR/IFR conditions this evening. Timing of wind shift to NW could be 1-3 hrs off from forecast. KEWR TAF Comments: A chance of brief MVFR/IFR conditions this evening. Timing of wind shift to NW could be 1-3 hrs off from forecast. KTEB TAF Comments: A chance of brief MVFR/IFR conditions this evening. Timing of wind shift to NW could be 1-3 hrs off from forecast. KHPN TAF Comments: IFR could last 1-2 hours longer than forecast. Timing of wind shift to NW could be 1-3 hrs off from forecast. KISP TAF Comments: A chance of brief MVFR/IFR conditions this evening. Timing of wind shift to NW could be 1-3 hrs off from forecast. .OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY... .Wednesday-Saturday...VFR. .Sunday...MVFR or lower in showers and thunderstorms. && .MARINE... South to SW swells have increased to 3 to 4 feet, and primary ocean waves remain below 5 feet, therefore, cancelled the SCA. Seas will gradually diminish through Wednesday with a lingering southerly swell around 4 ft on the ocean waters. Sub SCA criteria through Saturday morning. Seas will build on a southerly flow on the ocean waters Saturday, with 5 ft waves by Saturday night. Wind gusts should remain below 25 kt for the weekend. With an approaching complex frontal system to affect the waters by Sunday and a prolonged southerly flow, expect SCA conditions to exist into early next week. && .HYDROLOGY... Lingering showers and thunderstorms this evening will briefly produce heavy rainfall. Minor nuisance flooding is possible with up to an additional inch of rainfall possible. The heaviest rain will be across far eastern Long Island and southeast CT. An extended period of unsettled weather is forecast starting Sunday into next week. Due to the uncertainty this far out, there is a low chance of any hydrologic impacts. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...High Rip Current Risk until 9 PM EDT this evening for NYZ075- 080-081-178-179. NJ...None. MARINE...None. && $$ SYNOPSIS...CB/DW NEAR TERM...MET/DW SHORT TERM...DW LONG TERM...CB AVIATION...MD/JM MARINE...CB/MET/DW HYDROLOGY...CB/MET/DW EQUIPMENT...

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