Area Forecast Discussion
Issued by NWS Upton, NY

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084 FXUS61 KOKX 190749 AFDOKX Area Forecast Discussion National Weather Service New York NY 349 AM EDT Sat Aug 19 2017 .SYNOPSIS... A cold front will push east of Long Island this morning, with another cold front crossing tonight. High pressure will follow Sunday through Tuesday. A frontal system will pass across the area Wednesday into Wednesday Night followed by high pressure. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Shortwave trough over the Great Lakes this morning will pivot towards the region late today. At the surface, the cold front responsible for the heavy showers and thunderstorms yesterday will push just east early this morning. Morning fog/stratus and lingering Eastern showers will dissipate with its passage through the early morning. In its wake, a weak surface trough will linger over the region today, with a cold front approaching from the west for tonight. A much drier airmass in the mid-levels, and noticeably drier airmass at the low-levels (upper 60s/lower 70s dewpoints today versus mid/upper 70s of yesterday) will advect/mix down today. With shortwave energy still well west and mid- level warming, forcing and instability will be limited today. Would mainly expect some diurnal cu along and north of afternoon surface sea breeze. The mostly sunny conditions and warm temps aloft will allow temps to quickly rise well into the 80s today, around 90 NYC/NJ metro. Heat indices will run close to air temperatures. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY/... Vigorous shortwave trough approaches this evening and crosses the region tonight. At the surface, a weak cold front crosses the region this evening. High-res models indicating some organized convection developing/tracking across central PA/NY late this afternoon along this front, but expectation is that this activity quickly weakens as it approaches and crosses into the NW hills this evening due to lack of instability. Elsewhere, a low chance for an isolated shower overnight with shortwave/frontal passage. Zonal upper flow ensues for Sun into Mon. At the surface...high pressure builds in from the west Sunday into Sunday Night, and then gradually translates to the south and southeast Sunday night. The result will be a sunny, comfortably dry, and seasonably warm day on Sunday. As the high sinks south and east, heat and humidity will build build into the region Monday into Tuesday. Highs will generally be well into the 80s to lower 90s on Monday, and possibly lower to mid 90s for Tuesday. Models are indicating potential for isolated diurnal convection on Tuesday as instability increases and convectively induced vort energy rotates around the upper ridge. Low predictability at this point. && .LONG TERM /TUESDAY NIGHT THROUGH FRIDAY/... Decent model agreement with shortwave energy digging into the Great lakes Tue into Tue Night and then towards the NE US on Wed. An associated frontal system will bring the next chance for organized shower and tstm activity late Tue into Wed. A significant cool down then looks to follow for the end of the week. The models have been very consistent with this signal, although the exact magnitude of the cold airmass remains in question. It would not be totally surprising to see some lows in the furthest outlying areas touch the upr 40s next weekend. && .AVIATION /08Z SATURDAY THROUGH WEDNESDAY/... A cold front will move east of the region this morning and then another cold front will move across tonight. This will be followed by high pressure. MVFR to locally IFR conditions with fog and stratus are expected for all terminals before 10Z and then after that time, just for some interior and eastern terminals. VFR expected to return for all terminals after 13Z and continue through the rest of the TAF period. Timing of categorical changes could be off by 1-3 hours. Winds are light under 10 kt with a general W-NW flow into early today and then will be near 10 kt as winds back to a more south to southwest direction with sea breeze development this afternoon. Winds subside again tonight, becoming variable in direction but overall exhibiting a west to southwest flow for city and coastal terminals. .OUTLOOK FOR 06Z SUNDAY THROUGH WEDNESDAY... .Late tonight-Monday night...VFR. .Tuesday-Tuesday night...A chance of showers and thunderstorms with MVFR or lower conditions possible,otherwise VFR. SW gusts to 15-20 kt late afternoon and at night. .Wednesday...A chance of showers and thunderstorms with MVFR possible. SW gusts 15-20 kt. && .MARINE... Southerly swells of 5 to 6 ft will gradually subside from west to east this morning, with sub-sca conditions then expected through Tuesday afternoon as high pressure traverses southeast through the waters. Winds and seas will increase ahead of a cold frontal passage late Tuesday into Wednesday. Seas on the ocean may builds to SCA levels Tuesday Night and continue in southerly swells into Wed ngt. Winds and seas thereafter are expected to fall below SCA levels for late week. && .HYDROLOGY... Dry conditions through Monday. Impacts from potential showers and thunderstorms Tuesday into Wednesday are uncertain at this point. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...High Rip Current Risk through this evening for NYZ080-081. NJ...None. MARINE...Small Craft Advisory until 6 AM EDT early this morning for ANZ355. Small Craft Advisory until 11 AM EDT this morning for ANZ350- 353. && $$ SYNOPSIS...NV NEAR TERM...NV SHORT TERM...NV LONG TERM...JMC/NV AVIATION...JM MARINE...NV HYDROLOGY...NV is the U.S. government's official web portal to all federal, state and local government web resources and services.