Area Forecast Discussion
Issued by NWS Upton, NY

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000 FXUS61 KOKX 272003 AFDOKX Area Forecast Discussion National Weather Service New York NY 403 PM EDT Thu Oct 27 2016 .SYNOPSIS... Low pressure over the eastern Great Lakes tracks to the northeast tonight as another low develops over northeastern New Jersey this evening. This lows becomes the main low tonight and tracks along the New England coast through Friday. Meanwhile high pressure builds to the southwest Friday and Friday night. High pressure moves south of the area on Saturday with a cold front approaching from the north Saturday night. The front sinks through the area on Sunday as a weak low pressure moves along it. High pressure then returns Monday and Tuesday followed by a weak cold front for the middle of the week. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Colder air remained entrenched over Connecticut and Long Island into the afternoon as strong high pressure remained to the north keeping an easterly flow across much of the area. The warmer air was just to the southwest as a warm front extended from low pressure over Lake Erie and extended into southeastern Pennsylvania. At mid afternoon pressure falls were increasing over southeastern Pennsylvania as low level winds increased along the thermal ridge aiding lift. As this low deepens, and the other low moves east, into the early evening, winds along the coast will shift to the southeast and south, and warmer air will push into the coastal areas, possibly into coastal Connecticut. Precipitation has changed to all rain throughout the CWA, and will continue through this evening and into late tonight as the frontal system tracks through. As the southeastern Pennsylvania low becomes the dominate low this evening lift will increase and the warmer air will lead to destabilization. Lifted indices along the coast and into Connecticut fall to -1 to -2, and isolated thunder will be possible. In addition there will be a brief period of moderate to heavy rainfall. High temperatures will likely occur early this evening, then fall back later tonight. With the primary low then along the eastern New England coast by Friday morning, rain ends quickly from west to east after 06Z. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... Low pressure along the eastern New England coast early Friday tracks east through the day. A strong and gusty west to northwest flow develops with moderate cold advection and low level winds around 35 KTS mix to the surface. Weak ridging builds late in the day and into Friday night. Winds will lighten and decouple over the western zones Friday night and with clear conditions temperatures will fall off. However, weak warm advection does set up at that time. && .LONG TERM /SATURDAY THROUGH THURSDAY/... Deep anticyclone across the southern United States will help to build ridging towards the northeast on Saturday. Several shortwaves will traverse across southeast Canada but the trend in the models and ensembles has been for these shortwaves to stay well to the north. Have continued with a dry forecast for Saturday. Some mid and high level clouds are possible through the day, but sky conditions should largely be partly cloudy. High temperatures are a bit tricky on Saturday as there is some uncertainty with how warm it will get. Increasing westerly flow around the middle and upper level anticyclone to south will transport unseasonable warm air just above the surface. However, BUFKIT soundings point to a subsidence inversion around 925 hPa which will prevent mixing into the warmer air. Have sided with the warmer MAV guidance, which yields high temperatures generally in the upper 50s and lower 60s with urban NE NJ and NYC metro in the middle 60s. A cold front slowly sags south Saturday night with into Sunday with increasing cloud cover. Heights fall during this time period with another shortwave in the northern stream traversing across New England on Sunday. This will help push the front through the region Sunday and offshore Sunday night. Moisture is limited with this system, so will not go higher than chance PoPs. There should be enough lift from the front and an approaching upper jet for scattered showers in the afternoon and early evening. Temperatures are quite uncertain on Sunday and will depend the amount of cloud cover and placement of the front. Have gone with the warmest temperatures across southern portions of the area with highs in urban NE NJ and NYC in the upper 60s to possible around 70. The rest of the long term period will be characterized by ridging building in the middle and upper levels. High pressure moves overhead on Monday and then situates itself offshore on Tuesday. There could be a weak cold front that moves through on Wednesday or Wednesday night, but the timing of this will be dependent on how quickly the ridge breaks down. Monday will be the only day with seasonable temperatures with above normal temperatures then expected through Thursday. && .AVIATION /20Z THURSDAY THROUGH TUESDAY/... Low pressure and a warm frontal boundary converge upon the area this evening, followed by a cold frontal passage after midnight. Widespread MVFR/IFR conditions through tonight with gradual improvement to VFR following the cold frontal passage late tonight. Rain may be occasionally heavy this evening with isolated thunder possible at the coastal terminals. Low-level cold air has been stubborn to retreat across the area with winds remaining more NE along the CT coast. Wind shift will be slow to to shift to the E?SE this evening, if at all. Otherwise, E/SE winds with gusts to around 20 kt developing at the NYC and LI terminals, veering to the S this evening. E/NE less than 10 kt at KSWF. Following the cold frontal passage, a gusty W/NW wind develops and gradually ramps up through Friday morning. Gusts 25-30 kt on Friday. NY Metro Enhanced Aviation Weather Support... Detailed information, including hourly TAF wind component forecasts, can be found at: http:/ KJFK TAF Comments: Winds may be slower to veer to the SE this afternoon and gusts may be slower to develop. KLGA TAF Comments: Winds may be slower to veer to the SE this afternoon and gusts may be slower to develop. KEWR TAF Comments: Winds may be slower to veer to the SE this afternoon and gusts may be slower to develop. KTEB TAF Comments: Winds may be slower to veer to the SE this afternoon amd gusts may be slower to develop. KHPN TAF Comments: Winds may be slower to veer to the SE this afternoon and gusts may be slower to develop. Vsbys may vary between IFR and MVFR this afternoon. KISP TAF Comments: Winds may be slower to veer to the SE this afternoon and gusts may be slower to develop. .OUTLOOK FOR 18Z FRIDAY THROUGH TUESDAY... .Friday Afternoon...VFR with strong northwest flow. Gusts 25-30kt. .Saturday...VFR. Gusty southwest flow possible along the coast. .Sunday...Low chance of showers, mainly in the afternoon. .Monday and Tuesday...VFR. && .MARINE... Small craft conditions remain on the ocean waters into early this evening. Then as low pressure deepens along the coast, winds will increase, and small craft wind gusts will be likely across the remainder of the forecast waters through at least tonight. As low pressure moves to the northeast of the waters by Friday morning, winds shift to the west to northwest and with cold advection and the strong surface pressure gradient force, winds increase and become gusty. Wind gusts to gale force will be likely across the ocean waters east of Fire Island Inlet through Friday, with small craft gusts across the remainder of the water through Friday evening. Once gale gusts diminish on the eastern ocean waters a small craft will likely be needed into Friday night. Conditions will briefly fall below SCA levels early Saturday, but increasing SW flow during the afternoon and evening will bring winds to SCA levels on all waters. Ocean seas will also build to between 5 and 6 ft. Winds will weaken on the near shore waters Saturday night, but may remain around 25 kt on the ocean with seas around 5 ft. Sub- sca conditions are then forecast on Sunday as a cold front slowly moves across the waters. Winds could gust close to SCA levels on the ocean Sunday night as high pressure builds behind the front. Sub-SCA conditions are then expected Monday into Tuesday. && .HYDROLOGY... Rainfall will range from around a half inch across the western zones with near one inch across southeastern Connecticut and the twin forks of Long Island tonight. Dry Friday and Friday night. Widespread significant precipitation is not expected from this weekend into early next week. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from 8 PM this evening to midnight EDT Friday night for ANZ330-335-338-340-345. Small Craft Advisory until 6 AM EDT Friday for ANZ350-353. Gale Warning from 6 AM to 6 PM EDT Friday for ANZ350-353. Small Craft Advisory until midnight EDT Friday night for ANZ355. && $$ SYNOPSIS...DS/MET NEAR TERM...MET SHORT TERM...MET LONG TERM...DS AVIATION...DW MARINE...DS/MET HYDROLOGY...DS/MET is the U.S. government's official web portal to all federal, state and local government web resources and services.