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FXUS61 KOKX 232104
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
404 PM EST Sat Dec 23 2023

.SYNOPSIS...
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High pressure centered east of New England will drift a little farther east tonight as a weakening warm front and upper level disturbance approach. The front will dissipate nearby on Sunday, allowing the high to reestablish itself from the east on Christmas Day as the upper level disturbance moves across from the north. The high will then move back out into the Atlantic and slightly weaken Monday night through Tuesday. Low pressure will then approach Tuesday night into Wednesday, pass nearby Wednesday night, then pass to the northeast on Thursday. A cold front will approach Friday into Saturday.
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&& .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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Overcast skies (mostly mid level clouds) have spread across the entire CWA. MRMS shows some radar returns across parts of Orange County that are likely not reaching the ground due to dry sub- cloud air. Model guidance has trended drier with the approaching front, and have chance PoP only for parts of Orange County for tonight. Temps there should be aob freezing, so cold enough for some spotty light mixed wintry precip, with p-type of any precip more likely to be light snow before midnight and then light sleet or freezing rain after midnight as low levels warm up. Any QPF should be on the very light side, only a couple hundredths of an inch at most. HWO already mentions this potential, and due to the spotty nature of any expected precip will not be issuing winter headlines but may need SPS at some point. Low temps tonight should range from 25-30 inland, to 30-35 most elsewhere, to the upper 30s in NYC. Lows are likely to be reached this evening before remaining nearly steady overnight.
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&& .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
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The weakening front may still produce some spotty light precip on Sunday mainly inland N of NYC, while its associated upper level disturbance moves into upstate NY into a building upper level ridge and cuts off. High temps should range from the upper 30s well inland to the upper 40s across NYC metro/Long Island. The weak cutoff low should then turn S across New England and the CWA from late Sunday night into Christmas Day, and maintain mostly cloudy skies. Lows Sunday night will be from the lower 30s well inland to the lower 40s in NYC. Highs on Christmas Day will be a little milder, 45-50.
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&& .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
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Key Points : * Prolonged steady rainfall mainly Wednesday into Wednesday night, possible 1 to 2 inches. * Warmer than normal temperatures until late week, then airmass cools closer to normal * Forecast changes from previous forecast, a little cooler and PoP increased on Wednesday The synoptic pattern still transitions from ridging to troughing Monday night into mid week. This will be as surface high pressure moves farther out to sea. Meanwhile, a developing frontal low pressure system in the Southeast will approach the area. The large scale numerical weather prediction models do not strengthen this system too much despite an increasing subtropical upper level jet. The mid and upper level pattern remains positive tilting. The axis of the upper level trough with multiple positive vorticity advection maxima moves into the Northeast for the latter half of next week. The pattern results in a more of a progressive low that does not deepen too much. This will limit the heavy rain and thereby the total rainfall with the midweek event. The pattern for the latter half of the week depicts the more unsettled pattern where there will be periodic chances for rain and/or snow showers depending on the timing of when these vorticity maxima move in. The troughing aloft latter half of the week will also point to a transition to a relatively colder airmass for Friday and into the start of next weekend.
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&& .AVIATION /21Z SATURDAY THROUGH THURSDAY/...
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High pres gradually drifts E over the Atlc thru Sun. Mainly VFR thru the TAF period. A few pockets of light rain possible late tngt, but most of the activity is expected to remain N of the region. Mix with snow possible at SWF if the pcpn occurs. Chance of occurrence is about 30 percent, so continued the PROB30. There could also be some marine stratus and BR from the ocean tngt. Again the probability is low and this potential has been rolled into the PROB30. In the absence of any marine stratus on Sunday, VFR expected. Winds light and vrb thru the period. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Some variability in wind direction at JFK and LGA thru 01Z. Potential for the area to remain VFR thru the TAF period. If marine stratus develops overnight, MVFR may linger thru 18Z Sunday. OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY... Sunday: Mainly VFR. Chance of MVFR if marine layer develops. Christmas Day: VFR. Tuesday: Becoming MVFR aft 00Z Wed. Chance of rain aft 06Z. Wednesday and Thursday: MVFR or lower with rain. 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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Sub-SCA cond expected through daytime Wed. SCA cond are then increasingly likely Wed night through Thu night, mainly on the ocean waters. Some of the non-ocean waters could see higher gusts up to 25 kt at times.
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&& .HYDROLOGY...
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River flood warnings are still in effect along the CT River (handled by WFO BOX) and parts of the Passaic River basin (handled by WFO PHI). Localized minor/nuisance poor drainage flooding possible where relatively heavier rainfall occurs mid-week.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...BG/JM NEAR TERM...BG SHORT TERM...BG LONG TERM...JM AVIATION...JMC MARINE...BG/JM HYDROLOGY...BG/JM