Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 241130 AFDOKX Area Forecast Discussion National Weather Service New York NY 730 AM EDT Mon Jun 24 2019 .SYNOPSIS... High pressure builds east of the area today as a frontal system approaches from the west. The associated warm front approaches late tonight and moves through the region Tuesday, followed by a cold frontal passage Tuesday night. High pressure will mainly be in control for the remainder of the week. A cold front is then forecast to move across the region late Friday night into Saturday. Another high builds in Sunday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Minor adjustments were made to forecast based on latest observations. Another warm day is on tap for the region as heights continue to warm with the approach of the upper ridge axis. At the same time, the surface high builds offshore this morning with a developing onshore late this morning into this afternoon. There will be a gradual increase of mid and upper level clouds from the west, but for the most part looking at a sunny start with partly sunny conditions by late in the day. Highs will generally be in the lower to mid 80s, with slightly cooler conditions along the immediate coastline. This is a few degrees above normal. The rip current risk at the Atlantic Ocean beaches has been lowered from moderate to low today based on a forecast surf height of less than 2 ft and a gradual strengthening of south winds this afternoon. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM TUESDAY/... Upper ridge axis translates east of the area this evening with large scale warm advection strengthening ahead of an upper trough moving into the Great Lakes. At the surface, warm front approaches from the Ohio Valley and nears the region toward daybreak Tuesday. Decent warm advection coupled with marginal instability and PW value around 2 inches will result in showers breaking mainly after midnight, with the best chance being from 4 am to 8 am for NYC and points west, and from 8 am to noon for points to the east. As airmass gradually destabilizes aloft, a few thunderstorm are possible. Helicity is favorable for some rotation, however most of the buoyancy is above this layer with no surface based instability. Pockets of heavy rainfall will likely result in urban and poor drainage flooding, impacting the Tuesday morning commute. The steadiest rains pass eastern Long Island and southeast CT during the early to mid afternoon hours. As for the CAMS, the NAM 3km and HRRR are similar in development time, but differences arise with areal extent and the eastward progression. These details will likely vary from run to run, but the markers are there for a period of widespread showers along and ahead of the warm front. Once in the warm sector on Tuesday, the focus of concern shifts to potential convective development along and ahead of the approaching cold front. Significant drying in the warm sector and pronounced warming of the vertical temperature profile indicates only an isolated potential during the late afternoon and evening hours. Partly to mostly sunny skies will develop in the afternoon for all but far eastern sections where there could be stratus/fog in the onshore flow. Highs will range from the lower to mid 70s east, to the lower and mid 80s NYC and points north and west. There is a moderate risk of rip current development at the Atlantic Ocean beaches on Tuesday. && .LONG TERM /TUESDAY NIGHT THROUGH SUNDAY/... A cold front pushes offshore Wednesday morning, allowing showers to taper off from west to east. High pressure over the Tennessee Valley builds toward the region behind the cold front on Wednesday dominating the weather through the end of the week. A deep upper low across Ontario/Quebec is forecast to drop southward into New England this weekend. An associated surface low and cold front are expected to move through the area Friday night into Saturday with an increased risk for some showers and thunderstorms. Tuesday night through Saturday temperatures will be near to slightly above normal with temperatures on Sunday slightly below normal for this time of year. && .AVIATION /12Z MONDAY THROUGH FRIDAY/... High pressure will move offshore in the afternoon. A warm front approaches tonight. VFR today, and continuing through the evening. MVFR or IFR in showers expected after 8-10Z. Light winds generally W/NW early this morning. All areas become southerly this afternoon. Winds back to the E/SE this evening and overnight and lighten. 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: Timing of wind shift to the south may be off an hour or two. The afternoon KJFK haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KLGA TAF Comments: Timing of wind shift to the south may be off an hour or two. The afternoon KLGA haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KEWR TAF Comments: Timing of wind shift to the south may be off an hour or two. The afternoon KEWR haze potential forecast is GREEN...which implies slant range visibility 7SM or greater outside of cloud. KTEB TAF Comments: No unscheduled amendments expected. KHPN TAF Comments: No unscheduled amendments expected. KISP TAF Comments: No unscheduled amendments expected. .OUTLOOK FOR 12Z TUESDAY THROUGH FRIDAY... .Tuesday...Chance of showers/tstms with MVFR or lower conditions, becoming VFR late in the day. .Wednesday...VFR. .Thursday...Mainly VFR with a slight chance of an afternoon thunderstorm. .Friday...VFR. && .MARINE... Southerly wind develop on the waters today ahead of an approaching frontal system. Wind gusts on the eastern bays, sound, and ocean waters could top at near 20 kt Tuesday morning ahead of the warm front. The warm front will also be preceded by showers and isolated thunderstorms, mainly during the morning and early afternoon hours. Otherwise, winds and seas will remain below SCA levels through the period due to a weak pressure gradient. && .HYDROLOGY... A 1/2 inch of basin average rainfall is expected across the region late tonight into Tuesday. At this time no significant hydrologic impacts are expected with this system and through the remainder of the period. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO35 (162.55 MHz) remains off the air. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...Fig/DW NEAR TERM...DW SHORT TERM...DW LONG TERM...Fig AVIATION...PW MARINE...Fig/DW HYDROLOGY...Fig/DW EQUIPMENT...

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