Area Forecast Discussion
Issued by NWS Upton, NY

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989 FXUS61 KOKX 281459 AFDOKX Area Forecast Discussion National Weather Service New York NY 1059 AM EDT Wed Jun 28 2017 .SYNOPSIS... High pressure builds into the region today, and offshore on Thursday. A warm front moves north of the region Thursday night. Bermuda high pressure then dominates Friday into Saturday before a cold front moves through Sunday into Sunday night. The front may then linger just south of the region early next week. && .NEAR TERM /THROUGH TONIGHT/...
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Forecast still on track this morning. A 1024 mb high was centered over WV late this morning. The high will drift eastward through tonight. Sct flat cu were starting to develop in the higher elevations and should become more widespread this afternoon. Below normal highs are forecast, mainly in the upper 70s to near 80 degrees. Bumped up highs a couple degrees on Long Island since sea breeze (if any) will be arriving late.
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&& .SHORT TERM /THURSDAY/...
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As the high drifts ewd over the Atlantic, the winds will begin to respond to lowering pres over srn Ontario. This flow, coupled with the sea breeze circulation, should produce windy conditions along the coasts by late in the day. Otherwise, all other areas should have a sly breeze at least. The latest modeling from the NAM, GFS and ECMWF keeps any frontal systems N of the CWA, so pcpn has been removed from the fcst. Humidity will increase due to the increasing flow off the ocean, and temps will warm to aoa average as a thermal ridge begins to build in. The 00Z models have around 14-16C at H85 by the end of the day. If things unfold as currently expected, dangerous rip currents will be possible, particularly in the late aftn and eve, requiring a high risk fcst.
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&& .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... The main trend in the long term is for warmer and more humid conditions to take shape over the Tri-State. On the larger scale, a shortwave passes to the north Thursday night followed by rising heights and western Atlantic ridging taking shape Friday into Saturday. This ridge axis moves offshore Sunday as the next shortwave trough moves across New England through Sunday night. Another shortwave trough may follow early next week. Models and ensembles are in good agreement overall on the large scale through the weekend, then diverge a bit with the handling of any shortwaves early next week. At the surface, a warm front moves north of the region Thursday night. Bermuda high pressure will then influence the weather Friday into Saturday before a cold front moves through Sunday into Sunday night. There may be weak surface trough development to the NW of NYC each day before the cold front moves through Sunday. This front may then linger to the south early next week. Shower and thunderstorm chances appear slim Thursday night and mainly to the north and west of NYC. The same holds true on Friday into Saturday as ridging and heights build aloft. The best chance of any convection is mainly from the city north and west. Shower/storm chances increase a bit across the entire area on Sunday with the passage of the cold front and approaching shortwave. Drier conditions return on Monday with the next chance at showers and storms on Tuesday. Temperatures Friday and Saturday will be in the upper 80s with increasing humidity levels. A few 90 degree readings are also possible in the NYC metro and NE NJ. Max heat indices look to stay in the lower 90s both days at this time at these locations, with upper 80s elsewhere. Closer to the coast, onshore flow will keep highs in the lower to middle 80s. Temperatures should be a bit cooler on Sunday in the lower and middle 80s due to increasing clouds and higher coverage of showers/storms. Highs should gradually fall back closer to normal early next week. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/... High pressure builds into the region through today and offshore on Thursday. VFR conditions are expected through the TAF period. Only issue today is expected to be gusty winds 15-20 kt from the S-SW from late this morning until this evening. Winds diminish tonight before increasing further on Thursday. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component fcsts, can be found at http:/www.weather.gov/zny/n90 KJFK TAF Comments: High confidence in category forecast. Moderate confidence in wind forecast. Gust timing could be 2-3 hours off from forecast. KLGA TAF Comments: High confidence in category forecast. Moderate confidence in wind forecast. Gust timing could be 2-3 hours off from forecast. KEWR TAF Comments: High confidence in category forecast. Moderate confidence in wind forecast. Gust timing could be 2-3 hours off from forecast. The KEWR afternoon haze potential forecast is GREEN, which implies slant range visibility more than 6SM outside of cloud. KTEB TAF Comments: High confidence in category forecast. Moderate confidence in wind forecast. Gust timing could be 1-2 hours off from forecast. KHPN TAF Comments: High confidence in category forecast. Moderate confidence in wind forecast. Gust timing could be 1-2 hours off from forecast. KISP TAF Comments: High confidence in category forecast. Moderate confidence in wind forecast. Gust timing could be 2-3 hours off from forecast. .OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY... .Thursday...Mainly VFR. SW G20-25kt aftn/evening. Slight chance of an shower/thunderstorm at night. .Friday...Mainly VFR. SW G20kt late morning through the evening. Chance of shra/tstm, mainly for the afternoon into early evening. .Saturday...Mainly VFR. SW G20kt aftn/evening. Chance of shra/tstm mainly for the afternoon and night. .Sunday...Mainly VFR. Chance of shra/tstm. && .MARINE...
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Winds and seas will remain below SCA levels thru tonight. Southerly winds will then increase on Thu, with SCA conditions possible by aftn. Strong SW flow continues on the waters Thursday night into Friday, with SCA conditions likely on the ocean. Gusts will be highest Thursday night, 25-30 kt and then closer to 25 kt on Friday. Ocean seas will be 5-7 ft Thursday night, subsiding to around 5 ft late Friday. 5 ft seas may linger into Friday night. A weaker pressure gradient is expected this weekend leading to sub-sca conditions on all waters.
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&& .HYDROLOGY... No hydrologic impacts expected through the beginning of next week. && .EQUIPMENT... Observations from KFRG (Farmingdale, NY) may be sporadic. Observations from KHPN (White Plains NY) and KHVN (New Haven CT) are being disseminated through backup methods. All is due to an FAA communication line outage. Return to full service time is unknown. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JMC/DS NEAR TERM...JMC/Goodman/DS SHORT TERM...JMC LONG TERM...DS AVIATION...FEB/JM MARINE...JMC/Goodman/DS HYDROLOGY...JMC/DS EQUIPMENT...

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