Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 272023 AFDOKX Area Forecast Discussion National Weather Service New York NY 423 PM EDT FRI MAY 27 2016 .SYNOPSIS... Bermuda High pressure will remain across the region through the weekend. A cold front will pass through the area Monday into Tuesday. High pressure returns for the middle of the week. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... Convection has fired well nw. Will need to keep an eye on western zones, west of the Hudson, for possible shower and thunderstorm development early. HRRR continues to develop convection, along the seabreeze boundary. Will seabreeze boundary be enough to break the cap. With increasing cape as the afternoon progresses, coverage increases warranting chance pops. The forecast remains on track. Shortwaves moving through today are progged to be weaker than they were 24 hours ago. No changes to temps at this time. 850 mb temps and sea breeze progress should be close to those of yesterday, but yesterday featured a mostly sunny sky for most of the day for most locations. Will forecast high temps lower than what occurred yesterday. Looks like clouds will be more numerous and more opaque this time around. Have gone above a guidance blend for high temps, especially across Long Island where guidance has been too low during the past couple of days. There is a moderate risk of rip current development at the Atlantic beaches Today into this evening. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/...
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An evening shower/thunderstorm is possible northwest of the city, then with the loss of instability and only weak lift, dry overnight. For Saturday, still no significant source of lift outside of weak mid level shortwaves, but SBCAPEs will be building once again away from sea breezes. Again, will go with only slight chance to chance pops, focused more toward the afternoon and away from areas cooled by sea breezes. Highs on Saturday should be warmer than on Friday with warmer temps at the top of the mixed layer, and probably less cloud cover overall. Again, needed to adjust a guidance blend upward to account for the low bias as of late, especially over Long Island. There is a moderate risk of rip currents at the Atlantic ocean beaches on Saturday.
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&& .LONG TERM /SUNDAY THROUGH FRIDAY/...
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Models are in good agreement with the H5 pattern across North America to start...however timing and amplitude differences start to become apparent by the middle of the week and even more so by weeks end. Sub-tropical ridge over the western atlantic begins to break down and shift e during the latter part of the weekend but should still have enough of an influence on the area to keep any convection associated with an approaching back door cold front mainly to the north...although it may be close enough for some storms across the interior...so have maintained the low chc pops there. Moisture from a tropical disturbance off the Carolina coast is forecast to feed up the east coast along a pre-frontal trough Sunday night and Monday as a cold front approaches from the west. There is the potential for heavy rainfall with this system as a plume of tropical moisture surges northward ahead of the aforementioned system near the SE coast. These values are close to the maximum observed precipitable water for May 30 per SPC Sounding Climatology. An approaching shortwave in the northern branch and sfc cold front will shift this activity to the east Monday night. Deep layered ridging then returns through the rest of the week with the return to summer-like temperatures.
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&& .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
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The area will remain on the western side of the Bermuda High into Saturday with a thermal trough across then interior each afternoon. Convection in and around the NYC terminals remains weak and short- lived. The strongest activity is to the northwest in the vicinity of KSWF. Outside of a stray shower, most locations will remain dry. VFR outside of any convection. MVFR fog/haze possible - probable outside of NYC/Long Island terminals tonight. South-southeast winds around 10 kt this afternoon with local seabreeze enhancements. Easterly winds across LI Sound will influence KBDR through much of this afternoon. There is some uncertainty with the timing of the winds veering back to the south. Winds become SW at under 10kt this evening and then gradually increase back to around 10 kt Sat morning. 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: Occasional gusts 15-20kt possible with afternoon seabreeze. Low chance of afternoon/early evening shower/thunderstorm. KLGA TAF Comments: Occasional gusts 15-20kt possible with afternoon seabreeze. Low chance of afternoon/early evening shower/thunderstorm. KEWR TAF Comments: Occasional gusts around 15-20kt possible with afternoon seabreeze. Low chance of afternoon/early evening shower/thunderstorm. KTEB TAF Comments: Occasional gusts around 15-20kt possible with afternoon seabreeze. Low chance of afternoon/early evening shower/thunderstorm. KHPN TAF Comments: Low chance of afternoon/early evening shower/thunderstorm. KISP TAF Comments: Occasional gusts 15-20kt possible with afternoon seabreeze. .OUTLOOK FOR 18Z Saturday through Wednesday... .Saturday afternoon-Sunday...Mainly VFR with afternoon seabreezes. There is a chance of MVFR or lower in any isolated to scattered afternoon/evening showers/thunderstorms; mainly to the n/w of NYC. .Sunday night-Monday...MVFR or lower probable with showers and thunderstorms. .Monday night-Tuesday...Becoming VFR Monday night. Seabreezes likely Tuesday afternoon.
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&& .MARINE...
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The western periphery of Bermuda high pressure remains across the waters through Saturday. Winds and seas are expected to remain below small craft levels during this period, however, late this afternoon into early evening there could be occasional gusts to 25 kt over the ocean waters west of Fire Island Inlet. Will also be watching seas as they build close to 5 feet across the outer waters. A weak pressure gradient across the waters will then keep winds and seas below sca levels through Tuesday.
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&& .HYDROLOGY...
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Isolated to scattered thunderstorms are possible mostly for the inland areas this afternoon, this evening, and Saturday afternoon. However, no significant widespread precipitation is expected through the weekend. Rainfall amounts around one half to three quarters of an inch are possible on Monday with locally higher amounts. Localized urban or poor drainage flooding is possible from the heaviest rain.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...24/PW NEAR TERM...PW SHORT TERM...PW LONG TERM...24 AVIATION...DW MARINE...24/PW HYDROLOGY...24/PW

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