Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 210245 AFDOKX Area Forecast Discussion National Weather Service New York NY 1045 PM EDT SAT AUG 20 2016 .SYNOPSIS... A weak frontal boundary sitting across the region will gradually weaken tonight. A frontal system will approach from the Ohio Valley on Sunday and move through the region Sunday night. High pressure then dominates next week. A cold front approaches late next week. && .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/... A few showers have developed over southern CT this eve. There are some outflow boundaries still lingering across the area from earlier convection which may be triggering this. Otherwise...expect dry conditions until late tonight. There is some agreement amongst the guidance that a north to south oriented line of showers develops after midnight. They are all pointing to the area from western CT through western LI...so have added chc pops here into Sun morning. Stratus has also started developing across the east end of Long Island and SE CT. This is expected to continue expanding across the area through midnight with OVC conditions across the area by morning. Temperatures overnight fall into the 60s and lower 70s. && .SHORT TERM /6 AM SUNDAY MORNING THROUGH SUNDAY NIGHT/... A cold front associated with Canadian low pressure approaches the region Sunday...and then moves across the area Sunday night. An increasingly moist airmass is expected on Sunday ahead of approaching trough and cold front. Showers and thunderstorm are expected to develop during the late morning/early afternoon and increase in coverage through the afternoon and evening as the cold front approaches and moves through. The main threats with any thunderstorms appear to be torrential downpours with any convection. The threat for strong to severe storms appears to be quite low at this time due to late day/evening timing and weak instability. If instability can build or line is faster, cant rule out a storm or two with strong wind gusts for areas mainly west of the Hudson late day/early eve. With strengthening low-level veering wind profiles with weak wave development and low lcl`s would have to monitor for any rotating storms. The front moves across the region Sunday night with most of the precipitation coming to an end around or shortly after midnight. A few lingering storms may remain into early Monday morning across the far eastern sections. Temperatures on Sunday will climb into the 80s, with Sunday night lows falling into the 60s. A MAV/MET/ECS blend was used. There is a moderate risk of rip currents along the Atlantic facing beaches. && .LONG TERM /MONDAY THROUGH SATURDAY/... Cold front pushes well offshore Monday morning. Behind the front expect dry weather conditions as high pressure builds in from the west and dominates through the end of the week. Less humid conditions returns on Monday as dew points drop into the low to mid 50s behind the front. Humidity levels will increase by the middle of the week in response to an onshore flow with dewpoints back into the mid 60s to upper 60s. As for temperatures, expect near or slightly below normal temperatures on Monday and through the middle of the week, then back to above normal thereafter. A cold front approaches late in the week. && .AVIATION /03Z SUNDAY THROUGH THURSDAY/...
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High pressure slowly retreats to the northeast into Sunday morning. A cold front approaches from the west later on Sunday. Moderate to high confidence in MVFR conditions developing at all terminals tonight. Have slowed onset time to mainly after midnight - except at KGON where MVFR will just continue. Confidence in timing where MVFR is not already occurring is low-moderate. Low confidence in IFR overnight - except low-moderate at KGON - so have a TEMPO group there for early Sunday monring. MVFR conditions should linger through Sunday morning, then possibly lift to low end VFR (3500-5000 ft) ceilings in the afternoon. Showers/thunderstorms should move into western terminals 19-20z and KISP/KBDR 21-22z. There is also a low chance of isolated showers/drizzle at mainly western terminals overnight. Confidence in this remains to low to reflect in TAFs at this time. SE flow less than 10 kt through Sunday morning. Speeds could increase at city/coastal terminals to 10-15kt Sunday afternoon. Western terminals should see winds veer towards the S late Sunday afternoon. .OUTLOOK FOR 00Z MONDAY THROUGH THURSDAY... .Sunday night...Showers and thunderstorms likely with MVFR or lower conditions in the evening, then becoming VFR from W to E overnight. SE winds g20-25 KT possible. Higher gusts possible in thunderstorms. Conditions improving to VFR after 05Z. .Monday-Thursday...VFR. NW winds g15-20kt possible Monday afternoon/evening.
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&& .MARINE... Southeast winds tonight will continue into Sunday and increase to 10 to 20 kt. A cold front moves across the waters Sunday night, and winds shift around to the NW behind the front Monday morning. A few gusts to 20 to 25 kt are possible. Seas may also briefly build to 5 ft on the far eastern ocean zones. With low confidence of reaching Small craft conditions, will hold off on any headlines for now. High pressure builds Tuesday and Wednesday and winds lighten considerably. && .HYDROLOGY... Sunday afternoon through Sunday night, 1/2 to 1 inch of rain is expected. Minor urban flooding would be the main hydrologic impact from this rainfall...with a localized flash flooding threat from any training cells. Dry weather is then expected for much of next week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...BC NEAR TERM...BC/24 SHORT TERM...BC LONG TERM...BC AVIATION...Maloit MARINE...BC HYDROLOGY...BC

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