000
FXUS61 KOKX 191957
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
357 PM EDT Wed Apr 19 2023

.SYNOPSIS...
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A weak surface trough weakens early this evening as high pressure builds in from the northwest. The high builds offshore on Thursday. Meanwhile, a warm front will approach from the southwest as its associated low pressure system moves into the western Great Lakes region. This warm front will move north of the area Thursday night into Friday. A cold front with a wave of low pressure approaches on Saturday, moving through Saturday night into early Sunday. High pressure builds in early next week.
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&& .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/...
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An upper closed low and negatively tilted trough continues to move to the northeast of the region as an upper ridge builds into the eastern Great Lakes into the central Appalachians. A weak surface trough dissipates this evening as surface high builds in from the northwest. With nearly clear skies and winds becoming light ideal radiation cooling is expected. Mid and high clouds do increase a little late tonight across the interior as weak warm frontal forcing sets up. There will be a wide range of temperatures across the region with the coldest temperatures across the interior, and the warmest in the urban NYC area. The Long Island Pine Barrens may see overnight lows near freezing.
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&& .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY/...
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A high amplitude ridge builds toward the area Thursday into Thursday night, then across the region Friday, with the ridge axis moving to the east late in the day. At the surface high pressure moves offshore during Thursday as low and mid level warm advection increase. A warm front approaches during the day and likely lifts north late Thursday night into early Friday. The area will then be warm sectored Friday as 850mb temperatures rise to 12C to 14C. Mainly used the MOS GFS guidance for temperatures Thursday, and the a blend of the 50th to 75th NBM percentiles for Friday as temperatures will be well above normal, especially inland, away from the southerly marine influence coastal locations, as deep mixing develops by the afternoon.
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&& .LONG TERM /FRIDAY NIGHT THROUGH WEDNESDAY/...
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Heights fall to start the period with the exit of an upper ridge and the entrance of a closed low trough swinging into the Upper Great Lakes. At the surface, the warm front that lifted through on Friday lingers near or just north of the region Friday night into Saturday. BUFKIT soundings indicate the increased low-level moisture from the onshore flow may be sufficient to instigate some spotty light rain showers or drizzle overnight into Saturday morning under a canopy of low stratus. Any drizzle and fog should end by daybreak, though they could linger for eastern areas into Saturday morning. Despite the gradually lowering cloud deck, the bulk of Saturday appears dry as an attendant cold front and developing frontal wave approach late in the day. Ahead of this, temperatures climb from the 50s into the low-to-mid 70s away from the coast, and about 10 degrees cooler for coastal areas with the maritime influence (water temps remain in the 40s and lower 50s). Guidance has trended faster with the frontal passage, with 12z runs of global models moving the boundary through from west to east late Saturday into early Sunday. A narrow corridor of Atlantic moisture transport ahead of the front via increasing LLJ, as well as enhanced lift ahead of a wave of low pressure along the approaching front, results in a band of showers, and possibly a few embedded thunderstorms, moving through the area late Saturday evening and night. With the LLJ strengthening to around 40 to 50 kt just ahead of the front, this will allow increasing SE flow at the surface, with a few gusts likely in the 30 to 40 mph range Saturday night, especially with any convection ahead of the front. Given a fairly progressive flow, the rain moves through and exits by Sunday morning. Total rainfall largely remains under an inch, with a quarter to three quarters of inch expected. Winds lighten and veer westerly behind the front, with drying conditions Sunday and Monday as the trough continues to advance east over the region. The cyclonic flow likely aids development of some daytime cloud cover as surface high pressure builds in from the Mid- South. Temperatures next week will be a bit cooler behind the front, highs mostly in the 60s into midweek. With the quicker frontal passage, used a 3:1 combination of ConsALL and NBM for winds Saturday into Sunday. Otherwise, national blended guidance was largely followed.
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&& .AVIATION /20Z WEDNESDAY THROUGH MONDAY/...
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A weak surface trough across the area weakens early this evening as high pressure builds in from the NW. The high builds offshore on Thursday. VFR. WNW winds around 10-15kt with gusts around 20 kt will diminish by early this evening and become light out of the NW, then gradually veer to the NE tonight. Many locations will simply become light and variable overnight, especially for the terminals outside the metro area. A light southerly flow develops Thursday afternoon with local seabreeze enhancements. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Winds may vary between 280-310 through early this evening. OUTLOOK FOR 18Z THURSDAY THROUGH MONDAY... Thursday Afternoon-Friday: VFR. Saturday: VFR in AM, MVFR or lower develops towards evening with showers arriving. Sunday: MVFR or lower possible in showers in the morning, then VFR in the afternoon. Monday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90.
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&& .MARINE...
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With high pressure building into the waters tonight and moving offshore Thursday, and a warm front moving through Thursday night into Friday, winds and seas across the forecast waters will remain below advisory levels tonight through Friday. SCA cond likely develop on all waters late Saturday into Saturday night ahead of an approaching cold front and wave of low pressure. Isolated SE-S gales may be possible especially on the ocean and the adjacent lower harbor/bay waters late Sat night. Winds diminish from west to east Sunday morning, returning to sub- SCA cond on sheltered waters. Seas lower under 5 ft on the ocean by Sunday night.
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&& .FIRE WEATHER...
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A Red Flag Warning remains in effect for NJ as the combination of dry conditions, low humidity, and gusty winds will result in favorable conditions for the rapid spread of fires into early this evening.
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&& .HYDROLOGY...
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No hydrologic impacts through Saturday. A frontal system may bring up to an inch of rainfall late Saturday evening into early Sunday morning, with brief nuisance flooding possible in urban and poor drainage areas. Given antecedent dry conditions, no significant hydrologic impacts expected through mid next week.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...Red Flag Warning until 8 PM EDT this evening for NJZ002-004- 006-103>108. MARINE...None. && $$ SYNOPSIS...DR/MET NEAR TERM...MET SHORT TERM...MET LONG TERM...DR AVIATION...DW MARINE...DR/MET FIRE WEATHER... HYDROLOGY...DR/MET