Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 231949 AFDOKX Area Forecast Discussion National Weather Service New York NY 349 PM EDT TUE AUG 23 2016 .SYNOPSIS...
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High pressure over the region will slide offshore through Thursday. A cold front will slowly approach from late Thursday into Friday, and move across Friday evening. High pressure will follow for the weekend. Another frontal system will approach on Monday.
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&& .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/...
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High pressure will remain overhead through Wednesday morning. This will result in clear skies overnight, although continued southerly flow will allow dewpoints to slowly increase, resulting in less than ideal conditions for radiational cooling and overnight lows that are 5-10 degrees warmer than last night.
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&& .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/...
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High pressure begins to slowly shift offshore during the day on Wednesday. This will allow for increased southerly flow along with slightly higher temperatures and dewpoints. High clouds will then begin to increase overnight Wednesday night as the ridge flattens ahead of an approaching cold front.
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&& .LONG TERM /THURSDAY THROUGH TUESDAY/...
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Operational and ensemble models are in good agreement for the long term, especially with the passage of the cold front on Friday. In the mid and upper levels, a weak upper level trough moves through on Thursday. This trough looks stronger to the north of the area. At the surface, high pressure will be situated off the East Coast. This will pump in a warm and humid air mass, out ahead of an approaching cold front. Surface low pressure over southeastern Canada will trek east-northeast with its associated cold front approaching the area Thursday night. A pre-frontal surface trough should impact the area late Thursday night, mainly for areas north and west of New York City. Any precipitation should hold off until this trough moves over the area. So will push back slight chance POPs late Thursday time frame. Upper level flow looks to be rather zonal Thursday night into Friday, so would expect the cold front to be rather progressive, moving through late in the day Friday/early Friday night. However, not much in the way of moisture for this front to tap into, so much of the area could remain dry as the cold front moves through. some surface based CAPE will allow an isolated thunderstorm to develop. High pressure builds in behind the front for the weekend. Upper level ridging for late Saturday into Sunday, with another surface cold front approaching Sunday night. There is some uncertainty with the passage of this cold front. 12Z GFS is more progressive than the 00Z ECMWF and pushes the front through late Monday night with high pressure building in for Tuesday. The ECMWF stalls the front just to our south, with disturbances tracking along the boundary. As far as temperatures are concerned, seasonably warm for Thursday with temperatures in the lower to middle 80s, warmer for Friday under warm advection, with lower 90s possible in the New York City metro area. Not as warm for Saturday, but still above normal for this time of year. Thereafter, slightly cooler, but still above normal temperatures for the rest of the long term. Humidity levels will increase Thursday into Thursday night, with dew points in the lower 70s by Friday. Heat index values could approach the middle to upper 90s for the metro area on Friday, but this will only be for one day as the cold front ushers in a cooler and slightly less humid air mass for the remainder of the long term. Heat index of 100 in the metro area looks unlikely at this time.
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&& .AVIATION /20Z TUESDAY THROUGH SUNDAY/...
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High pressure over the region slides to the south tonight. VFR through the period. Sea breezes have developed coastal terminals today. KEWR/KTEB/KHPN likely shift to the west for a few hours before sea breeze moves in. Sea breeze front may have trouble making it completely through KEWR, but instead battle a W-SW flow and waver in the vicinity of the terminal. A few locations right along the coast may also experience some gusts to around 20kt. I dont think this lasts very long and will mention in a tempo group. Winds become light and veer to SW tonight. Seabreezes are expected once again on 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 few gusts to 20kt possible through about 22z. KLGA TAF Comments: Southerly sea breeze development expected between 18Z-20Z. KEWR TAF Comments: SE sea breeze development possible between 19Z-22Z. Wind direction could waver between WSW and SE during this time. KTEB TAF Comments: Sea breeze development likely between 20Z- 22Z. Wind direction could waver btwn WSW and S during this time. KHPN TAF Comments: Sea breeze development likely between 19Z- 22Z. KISP TAF Comments: A few gusts to 20kt possible through about 22z. .Outlook for 18Z Wednesday through Sunday... .Wednesday...vfr. afternoon seabreezes expected. .Thursday...Slight chance of late day and nighttime showers/tstms, with brief MVFR conditions possible. Best chances North and West of NYC. .Friday...Slight chance of afternoon showers/tstms, with brief MVFR conditions possible. .Saturday and Sunday...VFR.
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&& .MARINE...
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Winds and seas should remain below SCA criteria into early next week. There is still a small to medium chance that ocean seas and wind gusts could reach SCA criteria some time Thu night into Fri ahead of a cold frontal passage. There is also a suggestion of tropical swell encroaching on the waters by Sunday, with waves building to 5+ ft late in the long term period.
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&& .HYDROLOGY...
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No significant widespread precipitation is expected through the period.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...FEB/JP/MET NEAR TERM...FEB/MET SHORT TERM...FEB/MET LONG TERM...JP AVIATION...BC MARINE...FEB/JP/MET HYDROLOGY...FEB/JP/MET

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