Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 212348 AFDOKX Area Forecast Discussion National Weather Service New York NY 748 PM EDT THU JUL 21 2016 .SYNOPSIS...
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High pressure builds offshore through Friday. A cold front approaches Friday night and moves through early Saturday. High pressure returns Saturday night through Sunday. Another cold front approaches on Monday and passes through the area Monday night. High pressure builds into the area Tuesday through Thursday.
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&& .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/...
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The increase in warmth and humidity starts tonight with SW flow continuing as high pressure builds offshore. The center of the high will be moving farther offshore as the night progresses. The MCS activity well upstream will give some increase in mid and high level clouds late tonight into early Friday. With onshore flow and warm air advection, lows will trend several degrees warmer compared to the previous night.
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&& .SHORT TERM /6 AM FRIDAY MORNING THROUGH SATURDAY/...
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Shortwave and jet streak approach during the day but most forcing arrives Friday Night into early Saturday. The bulk of it stays north of the region. Friday starts out dry but increasing heat and humidity will make for heat advisory thresholds being met across NYC and much of Northeast NJ. Rest of region heat indices into the 90s. A high risk for rip current development at ocean beaches will be developing Friday morning...and continuing high through the evening due to southerly wind waves increasing to 3 to 5 ft and a residual 2 ft se swell. Showers and thunderstorms become more probable in the afternoon with increasing instability and at night when the forcing aloft arrives closer. Showers and thunderstorms taper off late Friday Night but with cold front boundary approaching and moving across early Saturday, a low probability of showers and thunderstorms will remain. Another hot day Saturday but relatively drier with the westerly flow. This should allow for more vertical mixing and lower dewpoints. Still though heat indices with higher actual temperatures but a little lower dewpoints will be well into the 90s once again for most places.
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&& .LONG TERM /SATURDAY NIGHT THROUGH THURSDAY/... High pressure builds into the area Saturday night into Sunday. Temperatures will be in the upper 80s to lower 90s on Sunday and Monday with dewpoints in the 60s, but heat indices at this time are expected to be below 95 degrees. Low pressure moving through the Great Lakes Monday...will push a warm front through the area Monday morning followed by a cold front Monday night. Scattered showers/thunderstorm are possible Monday, with convection ending early on Tuesday. Dry conditions return as high pressure builds across the area on Tuesday and remains in control through Thursday. Temperatures on Tuesday will be in the upper 80s to lower 90s with dewpoints in the mid 60s to around 70, allowing heat indices to climb into the mid 90s once again. Temperatures slowly fall back to near normal towards the end of the week. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/...
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High pressure remains offshore through Friday with an approaching frontal system from the Great Lakes late in the forecast period. A pre frontal trough is expected to develop in the vicinity of the northeast coast Friday afternoon, with a chance of scattered showers and thunderstorms. VFR through the TAF period. sea breezes will be weakening through 02z with winds shifting to the southwest. Southwest winds 5 to around 10 KTS expected tonight into early Friday morning. Southwest winds increase to around 15 KTS during the morning with gusts 20 to 25 KTS. 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: Friday afternoon gusts up to 30 KT will be possible. Scattered showers and thunderstorms develop 22Z to 23Z. KLGA TAF Comments: Friday afternoon gusts 25 to 30 KT will be possible. Scattered showers and thunderstorms develop 22Z to 23Z. KEWR TAF Comments: Friday afternoon gusts 25 to 30 KT will be possible. Scattered showers and thunderstorms develop 22Z to 23Z. KTEB TAF Comments: Friday afternoon scattered showers and thunderstorms develop 20Z to 21Z. KHPN TAF Comments: Friday afternoon scattered showers and thunderstorms develop 20Z to 21Z. KISP TAF Comments: Friday afternoon gusts 25 to 30 KT will be possible. Scattered showers and thunderstorms are possible toward 00Z Saturday. .OUTLOOK FOR 00Z Saturday through Tuesday... .Friday night...MVFR or lower possible in SCT TSRA. SW winds 15-20 KT with 25 KT gusts across NYC and Long Island. .Saturday through Sunday...VFR. .Monday and Tuesday...MVFR or lower possible in SCT TSRA.
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&& .MARINE...
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Marginal sca gusts in NY bight and adjacent waters will relax a bit late this evening with sub SCA conditions overnight under the influence of high pressure. The high pressure area moves farther offshore, giving an increase in the pressure gradient for Friday. Winds increase during the day, with ocean zones and South Shore likely increasing with gusts to 25-30 kt thresholds for the aft/eve. The increasing winds will increase fetch with ocean seas building to 5-6 ft for late Friday afternoon through Friday night. A cold front moves across early Saturday with conditions returning to below SCA Saturday. Below small craft advisory conditions are expected across the area waters Saturday night through Tuesday.
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&& .HYDROLOGY... Boundary layer winds increase Friday so thunderstorms Friday afternoon and evening will be faster moving, mitigating the flood threat. Still though, some localized minor urban and small stream flooding will be possible. No adverse hydrologic impacts are anticipated with scattered showers and thunderstorms Monday/Monday night. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Heat Advisory from noon Friday to 7 PM EDT Saturday for NYZ072>075-176-178. High Rip Current Risk from Friday morning through Friday evening for NYZ075-080-081-178-179. NJ...Heat Advisory from noon to 7 PM EDT Friday for NJZ004-006- 103>108. MARINE...Small Craft Advisory from noon Friday to 6 AM EDT Saturday for ANZ350-353-355. Small Craft Advisory from noon to 8 PM EDT Friday for ANZ345. && $$ SYNOPSIS...FIG/JM NEAR TERM...JM SHORT TERM...JM LONG TERM...FIG AVIATION...MET MARINE...FIG/JM HYDROLOGY...FIG/JM

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