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FXUS61 KOKX 062038
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
438 PM EDT Fri Oct 6 2023

.SYNOPSIS...
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A cold front approaches tonight as the remnant low of Philippe moves north, well east of the Delmarva coast. The cold front will move across the area Saturday into Saturday evening as the remnant low of Philippe reaches to off the New England coast and then near the Maine coast by Sunday morning. Low pressure remains north of the area into the beginning of next week, with frontal systems impacting the area around the middle and end of the week.
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&& .NEAR TERM /THROUGH SATURDAY/...
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Flood Watch in effect from late tonight through Saturday evening for northeastern New Jersey, the lower Hudson Valley, New York City, and Fairfield and Nassau counties. A longwave upper trough will be approaching tonight, and then moves into the northeast and mid Atlantic Saturday as the trough begins to interact with the remnant of Philippe. At the surface a cold front approaches tonight and moves through Saturday into Saturday evening, as the remnant low tracks well to the east. The frontal system will interact with tropical moisture from the remnant low late tonight into Saturday, and with increased lift, a weak low level jet, and precipitable water values around 1.5 inches, and warm cloud processes, periods of moderate to heavy rainfall will be possible. Hi res models have come into better agreement with the potential of a narrow band of heavy rainfall, and increased rainfall amounts. With higher confidence of this occurring has issued a Flood Watch as urban and poor drainage areas could see flash flooding. Also small and fast responding streams across northeastern New Jersey could flood as antecedent conditions remain wet from recent rainfall.
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&& .SHORT TERM /SATURDAY NIGHT/...
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The upper trough closes off and becomes negative Saturday evening as the remnant low merges with the frontal system. Precipitation will end Saturday night as the cold front tracks east and north of the area. Colder air moves in with temperatures returning to seasonal to slightly below for Saturday night.
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&& .LONG TERM /SUNDAY THROUGH FRIDAY/...
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Low pres will retrograde into wrn Quebec on Sun, dropping into the 970s by 00Z Mon. Despite the distance from the center of the sys, it will be breezy across the area due to the depth the low. Deep mixing will allow for temps to reach around 60, despite h85 temps falling to around 1C. Steep lapse rates during the day, so have added isold sprinkles to the fcst. Bkn flat cu around 3000 ft possible as well. Less wind on Mon as the low over Canada weakens and another sys approaches from the west. Flow aloft backs to the sw, but sfc temps remain blw normal with less mixing across the interior. Dry wx expected with lapse rates not as steep. A weak front comes thru late Tue into Wed with a few shwrs possible. Little change in airmass expected with temps remaining a little blw normal. Not much moisture to work with so any pcpn should be mainly light. Humidity increases Thu and Fri ahead of a strong cold front. Chances for rainfall increase thru the period, although the heaviest pcpn may hold off until Fri ngt or later. Temps warming back to around normal with smaller diurnal swings.
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&& .AVIATION /20Z FRIDAY THROUGH WEDNESDAY/...
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A frontal system approaches from the west tonight and moves through Saturday. Low confidence forecast as vsby and cigs vary from IFR (metro terminals) to VFR (KGON) across the area. Therefore, metro terminals are most likely to remain IFR to MVFR through the rest of the afternoon, with some brief improvement possible before IFR conditions return tonight. Brief LIFR or MVFR conditions are possible at these locations. Better conditions expected for eastern terminals through the day, but these areas area also expected to deteriorate overnight, just how much is the question. Scattered showers are moving through the metro terminals, with gradually increasing coverage through the night. A period of heavy rain is expected late tonight into late Saturday afternoon. Isolated thunderstorms are also possible during this time frame, but coverage was not high enough to put in the TAFs. ESE-E winds around 10 kt today and into tonight. Wind shift to SW then W and quickly to NW expected Saturday toward 18Z. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments likely due to changing flight categories. Potential for heavy rain with embedded thunderstorms late tonight into late Saturday morning could have impacts to the morning push. OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY... Saturday afternoon: MVFR or lower in rain showers. Wind shift to the W then NW with gusts to 15 to 20 kt possible with frontal passage. Sunday: VFR. W winds 15-20kt G25-30kt. Monday: Mainly VFR. Chance of showers late. SW G15-20kt Tuesday...Manly VFR. Chance of showers. S-SW G15-20kt. Wednesday...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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A SCA remains on the ocean waters tonight through at least Saturday night as increasing swell from the remnant low of Philippe move into the ocean waters. Behind a cold front Saturday night northwest winds and gusts will be increasing, with gusts reaching SCA levels across all the forecast waters Saturday evening, and a SCA has been issued. West winds will produce sca conditions on all waters Sun. Winds will decrease Sun ngt, but seas on the ocean will remain aoa 5 ft. Seas on the ocean are progged to be in the 3-5 ft range Mon- Tue, then less on Wed. Seas then build again on Thu ahead of a strong frontal sys. Otherwise, winds are progged to remain blw sca lvls Mon-Thu attm.
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&& .HYDROLOGY...
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The potential for a narrow band of heavy rainfall has increased, however, there is uncertainty as to where this may occur. A basin wide average of 1.5 to 2.0 inches, with locally as much as 2 to 3 inches, of rainfall is expected across much of northeastern New Jersey into the lower Hudson, New York City, Nassau county New York, and Fairfield county Connecticut, tonight through Saturday evening, and a Flood Watch has been posted for these areas with the potential for isolated to scattered flash flooding. There is uncertainty as to where a band of heavier rainfall will set up, with the possibility of being from northeastern New Jersey into Nassau and Fairfield counties. In locations outside of the Flood Watch 0.5 to around 1.0 inches of rainfall will be possible tonight through Saturday evening. No hydrologic impacts expected Sun-Fri.
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&& .TIDES/COASTAL FLOODING...
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Long period SE swells from the remnant low of Phillipe will build to 5 to 7 ft tonight into Saturday and to 6 to 9 ft Saturday night, and , presenting the likelihood of additional beach erosion/escarpment from an east to west sweep of 5 to 7 ft breaking surf. Because water levels are not astronomically high, the dune erosion threat during times of high tide is isolated. Swells subside Sunday into Sunday night.
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&& .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...Flood Watch from 2 AM EDT Saturday through Saturday evening for CTZ005-009. NY...Flood Watch from 2 AM EDT Saturday through Saturday evening for NYZ067>075-176>179. NJ...Flood Watch from 2 AM EDT Saturday through Saturday evening for NJZ002-004-006-103>108. MARINE...Small Craft Advisory from 6 PM Saturday to 8 PM EDT Sunday for ANZ331-332-335-338-340-345. Small Craft Advisory until 8 PM EDT Sunday for ANZ350-353-355.
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&& $$ SYNOPSIS...JMC/MET NEAR TERM...MET SHORT TERM...MET LONG TERM...JMC AVIATION...JP MARINE...JMC/MET HYDROLOGY...JMC/MET TIDES/COASTAL FLOODING...