Area Forecast Discussion
Issued by NWS Upton, NY

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347 FXUS61 KOKX 172003 AFDOKX Area Forecast Discussion National Weather Service New York NY 403 PM EDT Tue Apr 17 2018 .SYNOPSIS... A series of surface troughs will move across through Wednesday as low pressure tracks slowly north across the Canadian Maritimes. Another deepening low will approaches from the southwest Wednesday night, move across on Thursday, and then slowly pull up into the Canadian Maritimes on Friday. High pressure will then build in this weekend into early next week. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... A mid level shortwave trough, pivoting around the parent vortex over the Saint Lawrence River Valley will move across the region this evening, preceded by isolated to scattered showers. More importantly, another reinforcing shot of cold air and gusty west winds will follow. There will be some clearing as well with the passage of the upper trough. Lows will drop into lower 30s across the interior, and in the mid and upper 30s elsewhere. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Shortwave ridging and warm advection on Wednesday will result in a dry, milder day with highs in the mid to upper 50s, which is still a few degrees below normal. Gusty West winds will continue as well before weak high pressure builds across the area in the evening. This will be short-lived though as another amplifying shortwave trough over the Great Lakes and Ohio Valley states sends low pressure toward the area late. Decent thermal forcing ahead of the system will result in increasing clouds and light overrunning rain spreading in from the SW, mainly after midnight. Lows will be considerably warmer with the approach of a warm front and the cloud cover across the area, ranging from the upper 30s well inland to the upper 40s NYC metro. && .LONG TERM /THURSDAY THROUGH TUESDAY/... A somewhat blocky pattern aloft will persist through much of the forecast period. Low pressure will move across on Thursday, and with most of the thermal forcing to the north/east, expect light rain/drizzle to start the day. The associated cutoff low aloft will move slowly across New England on thu and into the Canadian Maritimes on Fri, and as it does so, first a potent mid level vort max rotating around it should produce showers from late Thu morning into Thu afternoon, followed by lower chances for rain/snow showers Thu night into Fri as low level cyclonic flow persists and additional weaker vort maxima rotate around. Temps will be on the cool side, running 5-8 degrees below average. As the cutoff low slowly releases its grip on the area, sfc high pressure will start to build in over the weekend and dominate early next week, with one more day of temps well below average on Sat, then moderation to near to slightly above average temps early next week. The combo of an approaching weak cold front and low pressure passing off to the south (and likely tracking farther north than model forecasts) may bring some initial chances for showers going into mid week. && .AVIATION /20Z TUESDAY THROUGH SUNDAY/... A surface trough moves east of the terminals tonight. VFR expected with BKN-OVC ceilings near 3.5-4kft with low chances of MVFR through early this evening. VFR expected thereafter with a decrease in clouds late tonight into Wednesday. A few rain showers will be possible which could result in brief MVFR conditions into early this evening. Mentioned vicinity showers in TAF for most terminals and TEMPO for KSWF TAF where there is higher chance for showers. Gusty westerly winds will prevail through much of the period. Sustained winds of 10-15 kt will gust at times to 20-25 kt, with peak gusts a few kt higher into early this evening. ...NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/ KJFK TAF Comments: MVFR conditions and peak gusts up to 30 kt possible before 01Z. KLGA TAF Comments: MVFR conditions and peak gusts up to 30 kt possible before 01Z. KEWR TAF Comments: MVFR conditions and peak gusts up to 30 kt possible before 00Z. KTEB TAF Comments: MVFR conditions and peak gusts up to 30 kt possible before 00Z. KHPN TAF Comments: MVFR conditions and peak gusts up to 30 kt possible before 01Z. KISP TAF Comments: MVFR conditions and peak gusts up to 30 kt possible 21-02Z. .OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... .Wednesday afternoon...VFR. W winds G20-25KT. .Wednesday night-Thursday...MVFR or lower possible in rain. NW winds G20-30KT Thursday afternoon. .Thursday night...MVFR or lower possible in rain/snow showers. NW winds G20-30KT. .Friday...VFR. Possible lingering rain showers mainly during the day, possible snow showers early morning, with MVFR or lower possible. NW winds G25-30KT day into early evening. .Saturday...VFR. NW winds G15-20KT. .Sunday...VFR. && .MARINE... SCA conditions will continue across the waters into Wednesday as low pressure over the Canadian maritimes slowly lift to the north. Conditions will gradually improve from west to east on Wednesday with high pressure briefly building in the evening ahead of low pressure in the Ohio Valley. After the low passes by on Thu, NW flow with SCA conds should develop on all waters by Thu night and last into daytime Fri, and the outer ocean waters may flirt with minimal gale force Thu night. Rough ocean seas should linger into Fri night, then quiet conditions expected this weekend. && .HYDROLOGY... Rain amounts below a half inch are expected Wednesday night through Thursday evening with no hydrologic impacts anticipated. Dry weather follows thereafter. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 AM EDT Wednesday for ANZ335-338. Small Craft Advisory until 4 PM EDT Wednesday for ANZ330-340- 345-355. Small Craft Advisory until 6 PM EDT Wednesday for ANZ350-353. && $$ SYNOPSIS...Goodman/DW NEAR TERM...DW SHORT TERM...DW LONG TERM...Goodman AVIATION...JM MARINE...Goodman/DW HYDROLOGY...Goodman/DW EQUIPMENT...// is the U.S. government's official web portal to all federal, state and local government web resources and services.