Area Forecast Discussion
Issued by NWS Upton, NY

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892 FXUS61 KOKX 182222 AFDOKX Area Forecast Discussion National Weather Service New York NY 622 PM EDT Mon Jun 18 2018 .SYNOPSIS... A cold front will move across the region late tonight through early Tuesday. Weak high pressure then builds in Tuesday into Tuesday night. A cold front moves through the area Wednesday and Wednesday night. High pressure then builds over the area through Thursday night then slides offshore Friday night into Saturday. A cold front may approach Sunday and move across the area on Monday. && .NEAR TERM /UNTIL 6 AM TUESDAY MORNING/...
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Forecast still on track. Made minor adjustments to temperatures, dewpoints and cloud coverage to reflect current observations and trends. Otherwise, pre-frontal trough ahead of cold front will be moving into the region for this evening and will act as a focus for developing showers and thunderstorms. However, there is vertical limits to development with residual ridging aloft. The ridge eventually becomes flattens and gives way to an approaching trough late tonight. In terms of hazards, heat advisory remains for NE NJ and the Lower Hudson Valley; this will end at 8PM. Other hazard would just be associated with the thunderstorms with the cold front moving across. Not expecting severe; SPC has interior parts of the region in marginal risk (5%) for severe wind gusts. Thinking here some thunderstorm activity could have strong wind gusts of 30-40 kt possible but bulk shear values are limited this far south with higher values near the base of the mid and upper level trough. Also thunderstorms will be capable of producing locally heavy rain. PWATS near 2 inches will enable for thunderstorms to tap into a moisture rich environment. The higher chances for thunderstorms will be with the remaining low level instability. The instability will be higher near NYC and locations to the north and west. This instability really starts to decrease more overnight. That time though is when the central low and cold frontal boundary will be pushing through so enough forcing will be there to keep for some thunderstorm activity for a part of the overnight. Convective activity trends downward after the cold front passage towards daybreak Tuesday A high risk of rip currents remains at Atlantic Beaches into this evening.
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&& .SHORT TERM /6 AM TUESDAY MORNING THROUGH TUESDAY NIGHT/... Weak high pressure builds in from the Great Lakes Tuesday into Tuesday night. The trough aloft moves into the Canadian Maritimes Tuesday and into Northern Atlantic Tuesday night. The ridging in the mid and upper levels stays anchored in the Southeast US leaving the local region with westerly zonal flow. Rain showers come to an end during the morning behind the cold front. More stable and drier air moves in behind the front during the day with deep N/NW flow in the atmosphere. This will provide downslope warming and while less humid with dewpoints in the mid to upper 50s. This will be from daytime mixing up to around or a little higher than 5 kft. The highs were taken from the relatively warmer MAV guidance ranging from mid 80s to near 90. However with aforementioned less humid conditions, apparent temperatures will be right near actual temperatures. For Tuesday, there will be moderate risk of rip currents at the ocean beaches, and high risk for rip currents again for Southeast Suffolk ocean beaches. && .LONG TERM /WEDNESDAY THROUGH MONDAY/... Low pressure will track along a boundary Wednesday afternoon. This could bring widespread showers and thunderstorms across the entire area Wednesday afternoon through Wednesday evening. Some of the thunderstorms are capable to produce torrential downpours along with gusty winds. As the boundary moves offshore Wednesday night showers will tapper off. Dry conditions expected on Thursday and into early Saturday. Unsettled weather then likely later Saturday and into the beginning of the work week with some rumbles of thunder mainly Saturday afternoon through Sunday. Temperatures during this time period will be near normal. && .AVIATION /22Z MONDAY THROUGH SATURDAY/...
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A cold front will approach this evening, and cross tonight. High pressure builds in from the north tonight. Sparse TSRA threat across the terminals this evening, with brief MVFR/IFR vsby and gusty winds, as a broken line of scattered showers and thunderstorms across NE PA and the Catskills of NY approaches. Have continued to mention via VCTS, with low confidence on how well this activity will hold together. An additional round of showers likely, with perhaps an embedded thunderstorm, as the front passes through NYC metro towards midnight. Otherwise, potential for a brief period of SCT MVFR/IFR stratus at KISP or KGON this evening. Gusty S-SW flow of 10-15 kt with gusts 20 kt into early evening, except sea breezes at KJFK/KLGA/KBDR/KISP with sustained winds 15-20 kt and gusts approaching 25 kt. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component fcsts, can be found at: http:/www.weather.gov/zny/n90 KJFK TAF Comments: Sparse convection potential this evening, btwn 00z and 02z. S winds 15-20ktG25kt through around 01z. KLGA TAF Comments: Sparse convection potential this evening, btwn 00z and 02z. S winds 15-20ktG25kt through around 01z. KEWR TAF Comments: Sparse convection potential this evening, btwn 00z and 02z. SW winds 15-20ktG25kt through around 00z. KTEB TAF Comments: Sparse convection potential this evening, btwn 00z and 02z. SW winds around 15ktG20-25kt through around 23z. KHPN TAF Comments: Sparse convection potential this evening, btwn 00z and 02z. KISP TAF Comments: S winds 15-20ktG25kt through around 00z. Low prob for IFR/MVFR cigs btwn 23z and 01z. .OUTLOOK FOR 18Z TUESDAY THROUGH SATURDAY... .Tuesday...Sight chance of an early morning shower with MVFR vsby, otherwise VFR. NW winds (right of 310 magnetic) 15G20KT. .Tuesday night-Wednesday...VFR. .Wednesday night...Showers likely, possibly a tstm, with MVFR or lower conds, as low pressure passes to the south. .Thursday-Friday...VFR. .Saturday...A chance of showers, possibly a thunderstorm, late Sat into Sat Night.
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&& .MARINE... In terms of wind gusts, SCA gusts will continue on the ocean much of tonight east of Fire Island Inlet. West of Fire Island inlet, there will be some brief wind gusts near 25 kt into early this evening. The mixing will be limited with a low level inversion, warmer air above above relatively cooler SSTs. Weak high pressure builds in Tuesday and Tuesday night with a weak pressure gradient. Ocean seas will lower Tuesday morning. The winds and seas will stay below SCA criteria thereafter through Tuesday night. Below SCA conditions expected across all area waters Wednesday through the end of the week. && .HYDROLOGY... On average between a quarter to a half inch of rain will fall over the area this afternoon and tonight. However, given the expected abundant low level moisture, there is the potential for locally heavy rainfall with any given storm with perhaps up to near an inch in some spots. As a result, there is the potential for minor flooding, especially for an area experiencing repeated storms producing locally heavy rainfall. Widespread showers and thunderstorms possible Wednesday afternoon and night. Some storms are capable of producing heavy downpours, with a threat for urban flooding. No significant widespread hydrologic impacts are expected Thursday through the weekend. && .EQUIPMENT... NYC NOAA Weather Radio Station KWO-35 (162.55 MHz) remains off the air for an extended period of time. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...Heat Advisory until 8 PM EDT this evening for NYZ067>071. High Rip Current Risk until 9 PM EDT this evening for NYZ075- 080-178-179. High Rip Current Risk through Tuesday evening for NYZ081. NJ...Heat Advisory until 8 PM EDT this evening for NJZ002-004-006- 103>108. MARINE...Small Craft Advisory until 9 PM EDT this evening for ANZ345- 355. Small Craft Advisory until 9 AM EDT Tuesday for ANZ350. Small Craft Advisory until 6 AM EDT Tuesday for ANZ353. && $$ SYNOPSIS...Fig/JM NEAR TERM...JM SHORT TERM...JM LONG TERM...Fig AVIATION...NV/DW MARINE...Fig/JM HYDROLOGY...Fig/JM EQUIPMENT...//

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