Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 251328 AFDOKX Area Forecast Discussion National Weather Service New York NY 928 AM EDT Wed Apr 25 2018 .SYNOPSIS... Low pressure approaches from the south today as passes across the area tonight. The low moves into New England Thursday. Low pressure tracks through the area on Friday, followed by a cold frontal passage over the weekend. High pressure then builds in for the beginning of next week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Overall model agreement is noted with regard to main upper level and sfc features. Weak shortwave approaching from the south just ahead of northern stream shortwave that tracks across the Great Lakes region. Sfc low approaches from the south, moving right up the eastern seaboard. Gusty easterly winds this morning are anticipated, then winds should diminish as the low approaches and the pressure gradient weakens. Rain this morning could be heavy at times per global models and high resolution simulated reflectivity, with a focus just east of NYC. In general, QPF amounts have trended down somewhat, but still expect around an inch, with a range of 1/2 inch to up to 2 inches in spots. Once again, cannot rule out some thunder, mainly mid morning into the afternoon due to weak elevated instability. Temps will struggle to rise much, with late day highs expected once the steadier rain begins to taper somewhat. Blended MET, MAV and ECS data. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM THURSDAY/... Sfc low moves in the general area of NYC tonight as northern stream possibly phases with weakening shortwave, although degree of phasing remains in question. Regardless, winds lighten, and fog will develop due to the recent rain, light winds and minimal T/Td spread. A few showers are possible as the low and sfc trough passes. Any fog lifts late tonight as westerly wind flow behind departing low to the north stirs up the boundary layer, and drier air moves in. Lows range from the upper 40s to lower 50s per MOS blend. On Thursday, sunshine returns, mixed with a few clouds and any rain showers remain to the north, closer to upper shortwave, sfc low. Westerly flow will allow for deeper mixing, and temps rising well into the 60s. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... The ECMWF and GFS are in very good agreement with low pres tracking thru the area Fri. The sys is the remnants of the upr low currently over Neb. The modeling indicates a weak sys as the low runs out ahead of an approaching upr trof. The thermals indicate all rain. The timing is late Fri and Fri ngt attm, although some timing changes cannot be ruled out. A more intense low would be possible if the upr trof arrives quicker, or if the remnant low slows. A cold front then brings a chc for some more shwrs on Sat. Everything is progged to clear out on Sun with some fair wx clouds likely as the cold pool aloft passes thru. The post frontal high reaches PA Sun ngt. This should be close enough to allow for the winds to decouple and produce prime radiational cooling cond. As a result, the colder MEX was used for temps Sun ngt as opposed to the warmer model blends. Frost/freeze issues are possible if this unfolds as currently expected. Fair wx with a warming trend for the beginning of next week with an upr ridge building into the region. && .AVIATION /14Z WEDNESDAY THROUGH SUNDAY/... Low pressure approaches from the southwest tonight into Wednesday, and then moves overhead Wednesday Night. Mainly IFR, with light to moderate rain across much of the area. Some pockets of heavy rain will be possible during the mid to late morning hours. Can not rule out an isolated tstms into early afternoon. Potential for LIFR or lower conds in stratus/fog for evening push. LIFR stratus and fog expected through the overnight. Conditions improve late tonight/early Thursday back to VFR. E winds are increasing with to gusts to 25kt for coastal terminals Wed morning. Winds subside in the early afternoon, becoming light and variable for evening push. Winds become westerly late late tonight/early Thursday morning. LLWS possible with SE winds at 40-45 kt at 2 kft. 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: Isolated thunder possible. Occasional wind gusts may be higher than forecast. The afternoon KJFK haze potential forecast is YELLOW...which implies slant range visibility 4-6SM outside of cloud. KLGA TAF Comments: Isolated thunder possible. Occasional wind gusts may be higher than forecast. The afternoon KLGA haze potential forecast is YELLOW...which implies slant range visibility 4-6SM outside of cloud. KEWR TAF Comments: Isolated thunder possible. Occasional wind gusts may be higher than forecast. The afternoon KEWR haze potential forecast is YELLOW...which implies slant range visibility 4-6SM outside of cloud. KTEB TAF Comments: Isolated thunder possible. Occasional wind gusts may be higher than forecast. KHPN TAF Comments: Isolated thunder possible. KISP TAF Comments: Isolated thunder possible. .OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY... .Thursday...VFR. .Friday-Saturday...VFR. A chance of showers with areas of MVFR conditions. .Sunday...VFR. W wind 10-15KT, G20-25KT. && .MARINE... Gusty easterly winds in the 20 to 25 kt range this morning will diminish this afternoon as low pressure approaches from the south. A few gusts to 30 kt are possible over the ocean waters this morning. Seas build in response to the increasing east winds. As the low moves nearby, then to the north tonight, light winds will shift to the west and pick up in speed once again. Westerly winds are forecast Thursday as the low passes further to the north. SCA conditions are expected through Thursday, mainly for elevated ocean seas, but winds should gust as well. For non ocean waters, SCA remains up for this morning, but will extend eastern LI Sound and Peconic/Gardiners Bays through 6 pm as winds may linger across these locations a bit longer. Low pres passing thru the region on Fri followed by a cold frontal passage on Sat will keep seas at sca lvls on the ocean. Elsewhere, winds and waves look to remain blw criteria. Winds and seas blw sca lvls all waters Sun-Tue with high pres building in from the w. && .HYDROLOGY... A widespread 0.50-1.50" of rain is likely today. Heavy rain at times could cause minor urban and poor drainage flooding, especially if the higher end of the expected rainfall range is realized. Expecting the bulk of the rain to fall this morning, perhaps lingering into late afternoon across SE CT. No hydrologic impacts are anticipated Fri-Tue. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 2 PM EDT this afternoon for ANZ335- 338-345. Small Craft Advisory until 6 PM EDT this evening for ANZ330- 340. Small Craft Advisory until 6 PM EDT Thursday for ANZ350-353- 355. && $$ SYNOPSIS...JMC/PW NEAR TERM...JMC/PW SHORT TERM...PW LONG TERM...JMC AVIATION...CB/BC MARINE...JMC/PW HYDROLOGY...JMC/PW EQUIPMENT...

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