Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 261640 AFDOKX Area Forecast Discussion National Weather Service New York NY 1240 PM EDT Sun Mar 26 2017 .SYNOPSIS... High pressure centered over eastern Canada and extending into New England and the northeast will gradually slide east today. A stationary front well to the southwest will approach as a warm front tonight and move into the area Monday. Another frontal system affects the region Tuesday and Tuesday night. High pressure builds to the west Wednesday and Thursday. Another low pressure system approaches Friday. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Center of Canadian high pressure gradually slides to the coast by late in the day. Temps will run a good 5 to 10 degrees below seasonable today with cold air damming and cloud cover. Max and hourly temp trends have been adjusted down slightly. A swath of light rain over Se CT will push east by mid afternoon, coincident with an elevated warm front and corresponding zone of theta e advection. The threat for icing has ended. Some spotty light rain activity possible across the region this afternoon associated with some weak vort energy...but overall coverage and probabilities look slight under shortwave ridge axis. && .SHORT TERM /6 PM THIS EVENING THROUGH 6 PM MONDAY/... The closed and nearly cut off low that was over Missouri will continue to open and weaken as the shortwave gets picked up by a weak southern stream flow, and the wave moves into the eastern ridge. There remains some timing difference with the movement of the warm front and low tonight into Monday. Also, with weak forcing unsure how much precipitation will occur. So have lowered probabilities into the likely category, with the higher chance west and north late tonight into Monday. && .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/... With the wave continuing to dampen late Monday into Monday night with weak ridging ahead of the next shortwave, there may be a break in the precipitation. However, with the uncertainty, and to keep continuity have continued with slight chance probabilities Monday night. Yet another shortwave approaches in the weak southern stream as this wave also dampens as wave approaches the mid Atlantic. There are timing differences and whether or not the shortwave will phase with a digging northern stream shortwave Tuesday. With uncertainties will keep probabilities at low chance Tuesday into Tuesday night. Wednesday and Thursday look to be dry with high pressure building in. Cold air advection appears to be delayed enough to the point where highs on Wednesday end up above normal, then near-normal for Thursday. Friday could be completely dry as well, but perhaps some rainfall sneaks into the western zones by the end of the day. High temps again near normal. Global models then disagree with the track of an area of low pressure that could bring rainfall on Saturday. Have capped PoPs at 40% for now. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/... High pressure will build southward across the area today with a brief push of drier air this morning. However, daytime heating will likely lead to the redevelopment of MVFR conditions across the area, lowering to IFR tonight. There is potential for brief improvement this evening for a few hours before dark, so subsequent TAF amendments may be needed. Conditions overnight may fall below minimums ahead of an approaching warm front and will need to be monitored. N-NE winds around 10 kt will become more easterly, with a few gusts G15-20KT possible in the afternoon at the coastal/NYC metro terminals. .OUTLOOK FOR 12Z MONDAY THROUGH THURSDAY... .Monday...IFR/LIFR to start. Conds could improve to MVFR or VFR by late morning or afternoon if the warm front moves through. .Monday night-Tue night...IFR likely, LIFR possible with low clouds/fog. .Wednesday...VFR. NW winds G20-25KT, possibly stronger. .Thursday...VFR. && .MARINE... Marginal easterly SCA gusts are expected on the ocean waters through tonight. The resultant easterly fetch will allow for ocean seas to build to 4 to 7 ft. Winds are expected to weaken and veer se on Monday as a warm front works into the waters...but e/se swells will likely keep seas at SCA levels through the evening. Otherwise, sub-sca conditions are expected across all waters briefly on Tuesday before gradually building through the evening in strengthening southerly flow ahead of a low pressure approaching from the west. Strong west-northwesterly flow with gusts to 25 kt will develop on Wednesday as a cold front passes which will initially allow seas to stay elevated at SCA levels before gradually shifting east of the ocean waters. Stronger winds may persist into Thursday before weakening by late week as high pressure briefly builds over the area. && .HYDROLOGY... One quarter of an inch to one half an inch of rainfall is possible today through Tuesday night. No hydrologic issues are anticipated through Tuesday. && .TIDES/COASTAL FLOODING... Latest surge guidance indicating that water levels should stay safely below minor flood thresholds for tonight and Monday Morning high tide. As astronomical tides rise through the week...water levels may come close to minor levels during high tides in the most vulnerable spots on Tue/Tue Night ahead of approaching low pressure. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 7 PM EDT Monday for ANZ350-353-355. && $$ SYNOPSIS...MET NEAR TERM...NV SHORT TERM...MET LONG TERM...JC/MET AVIATION...MD MARINE...MD HYDROLOGY...MET TIDES/COASTAL FLOODING...NV is the U.S. government's official web portal to all federal, state and local government web resources and services.