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. --
000 FXUS61 KOKX 260102 AFDOKX Area Forecast Discussion National Weather Service New York NY 902 PM EDT Mon Sep 25 2017 .SYNOPSIS... A broad area of high pressure will remain over the area through Tuesday. A cold front moves through the region Wednesday night, followed by brief high pressure building in from the west through late week. Another surface low and attendant cold front pass through Friday night, followed by strong Canadian high pressure settling in across the area through the weekend. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/... A 1019 high was centered from VT to the n atlc. This sfc ridge will remain in place n of the fcst area overnight. At the same time, stratus and fog was expanding and moving slowly westward in a light flow. At this time do not expect that the fog will become dense on the land, however, patchy dense fog will be possible. Otherwise, dry weather and clear skies as aftn cu will dissipate this eve. A blend of guidance, which was in good agreement, was used for temps. A high risk for rip currents and a high surf advy remain in effect thru Tue ngt. Nassau and NYC remain out of the high surf advy attm with waves progged to avg blw 7 ft. This would change, particularly for Nassau county, if the swell comes in any higher than what is currently modeled. && .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Maria will slowly track nwd and the sfc high will remain in place thru the period. This will result in a slight increase in the wind. Morning fog and stratus is expected to burn off, at least across the wrn 2/3 of the cwa. Time heights show moisture is shallow, but the fog and stratus are still out there today, so it is entirely possible it lasts thru most if not all of the day for parts of ern CT and LI. High clouds will also increase from the sw, so sunshine where there is not the low stuff will be somewhat filtered. With the marine influence, the raw model data was blended in for high temps yielding numbers several degrees blw guidance. For the overnight, it is still uncertain how much fog will develop with winds likely staying abv 5 kt or so. Some of the modeling is producing measurable pcpn across portions of the area. With a lack of lift across the area, the fcst included patchy fog and dz for the majority of the area, with more of a mist than thick fog expected attm. Temps were a blend of the guidance and raw model data. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... With persistent onshore flow, Wednesday morning may initially have fog and/or stratus and perhaps some light drizzle closer to the coast as moisture remains beneath the low-level inversion. Conditions will improve through the day with a final stretch of well above normal temperatures before the cold front moves through from northwest to southeast in the evening to overnight. Overall the front is expected to be moisture starved, with very little, if any precipitation with its passage. Although temperatures on Thursday will be a few degrees above normal in gusty northwest flow, dew points will gradually lower through the day as high pressure builds in, leading to more comfortable conditions. Thereafter, temperatures will fall to near or slightly below seasonal values as a strong Canadian high builds in from the northwest. Conditions will mainly be dry, with the exception of Friday night as a weak low passes through the area. && .AVIATION /00Z TUESDAY THROUGH SATURDAY/...
-- Changed Discussion --
High pressure remains across the region through the TAF period. Stratus/fog back is moving onshore and impacting all terminals except KSWF through 03z or so. It is also expected to move into KSWF although not until around 06z. With the exception of KGON and possibly KJFK/KISP/KBDR vsbys should not come down right away, but should take a few hours. Some uncertainty with how low the vsbys get overnight, but flight category will already be in the IFR/LIFR range anyway. These low conds will continue through 12z and then start to mix out from W to E due to heating and daytime mixing. KGON may remain MVFR through the day with the flow becoming onshore again and then decrease around 00z again. S/SE winds 5-10 KT will become light/vrb overnight. NE/E winds 5-10 KT develop Tue morning and shift to the SE again mainly during the late morning/early aftn. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/ KJFK TAF Comments: Timing of VFR returning Tue morning may be +/- 1-2 hours. KLGA TAF Comments: IFR expected to move in between 02z and 03z. Timing of VFR returning Tue morning may be +/- 1-2 hours. KEWR TAF Comments: IFR expected to move in between 03z and 04z. Timing of VFR returning Tue morning may be +/- 1-2 hours. KTEB TAF Comments: IFR expected to move in between 03z and 04z. Timing of VFR returning Tue morning may be +/- 1-2 hours. KHPN TAF Comments: IFR expected to move in between 03z and 05z. Timing of VFR returning Tue morning may be +/- 1-2 hours. KISP TAF Comments: Timing of VFR returning Tue morning may be +/- 1-2 hours. .OUTLOOK FOR 00Z WEDNESDAY THROUGH SATURDAY... .Tuesday night-Wednesday...MVFR to IFR possible with patchy fog and/or stratus and a low chance of showers. .Wednesday night-Thursday...MVFR or lower possible with isolated to scattered shower activity. .Thursday night-Friday...VFR. .Saturday...Mainly VFR, except MVFR possible in any showers.
-- End Changed Discussion --
&& .MARINE... Stratus and fog, with areas of dense fog, were moving into the forecast waters from the east and will spread westward through this evening and into late tonight. Visibilities may fall to as low as 1/4 nm at times, but will also be generally under 1 nm. The fog is expected to persistent into Tuesday morning, with improvement across the western waters first, and may be earlier than 14Z Tuesday. A dense fog advisory has been posted for all but the New York Harbor through 14Z Tuesday. Swell associated with Maria will continue to increase thru Tue. A sca for seas therefore remains in effect thru Tue ngt. Otherwise, winds will remain lgt thru the period. Lingering swell from T.C. Maria will likely allow seas to remain at SCA-levels through late week, before gradually subsiding this weekend as high pressure builds from the north. There will be a chance for winds around 15 to 20 kt with gusts 25 to 30 kt on Thursday following a cold frontal passage, but otherwise winds will remain below SCA-levels. && .HYDROLOGY... No hydrologic impacts expected the next 7 days. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...High Rip Current Risk through late Tuesday night for NYZ075- 080-081-178-179. High Surf Advisory until 6 AM EDT Wednesday for NYZ080-081. NJ...None. MARINE...Dense Fog Advisory until 10 AM EDT Tuesday for ANZ330-335-340- 345-350-353-355. Small Craft Advisory for hazardous seas until 6 AM EDT Wednesday for ANZ350-353-355. && $$ SYNOPSIS...JMC/MD NEAR TERM...JMC/MET SHORT TERM...JMC LONG TERM...MD AVIATION... MARINE...JMC/MD/MET HYDROLOGY...JMC/MD is the U.S. government's official web portal to all federal, state and local government web resources and services.