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FXUS61 KOKX 180906
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
406 AM EST Thu Jan 18 2024

.SYNOPSIS...
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High pressure centered to the south slides offshore this afternoon. Low pressure develops along the Mid Atlantic coast tonight and passes east of the area on Friday. High pressure builds south of the region through the beginning of next week, then over the Atlantic for the middle of the week.
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&& .NEAR TERM /THROUGH TONIGHT/...
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After the coldest day since late 2022, temperatures remain 5 to 10 degrees below normal today, though moderating several degrees from Wednesday. Still a frigid start across the Tri- State, mainly teens and lower 20s early this morning with the coldest locales in the single digits. A light westerly flow is leading to wind chills in the single digits for most this morning. Surface high pressure centered over the Southeast helps keep conditions relatively tranquil through the day. As a weak disturbance approaches from the west, cloud cover increases into the afternoon. While a spotty snow shower or two can`t be ruled out across the far interior, dry air at the surface should prevent much from reaching the ground. Temperatures this afternoon range from the upper 20s inland, to around freezing at the coast. Tonight, shortwave energy rounding the trough aloft swings east and begins to spur cyclogenesis off the Carolina coast. It`s possible a few flurries or light snow develops toward daybreak, though with dry air to contend with, this may hold off until later in the morning. Temperatures overnight fall back into the 20s.
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&& .SHORT TERM /FRIDAY THROUGH FRIDAY NIGHT/...
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Surface low pressure spins up off the Mid-Atlantic into Friday, passing south and east of the region through the day. Meanwhile an upper level low embedded in a trough over the Great Lakes begins to interact with the surface low. This likely creates an inverted surface trough over much of the Mid-Atlantic which will help bring in moisture from the offshore low pressure. Forcing from the upper level jet will aid lift along the inverted trough at the surface which should allow for a shield of light snow to develop over much of the area by Friday morning. By mid-morning, much of the area should be enveloped in a light snow. This snow continues through the day as the surface low pushes to the east. Unlike recent events, profiles support all snow down to the coast, with surface temperatures in the 20s and lower 30s, and sufficient deep layered cold air aloft. The exact placement and intensity of the offshore low and associated inverted trough over the area plays a crucial role in the amount of snow that falls over the area. There may be a relatively sharp north to south cutoff of precipitation as subsidence and dry air north of the surface trough may limit snowfall. Additionally, any banding within the inverted trough may locally enhance snowfall during the afternoon on Friday. Light snow continues into late day or early evening, and impacts are expected for the PM commute with falling snow and reduced visibilities. QPF is expected to be light, generally under a quarter inch total, and thus, accumulations should be light, with 2-3 inches across the NYC metro and Long Island, and 1-2 inches for the Lower Hudson Valley and Southern Connecticut. While a relatively minor event, whether by snowfall or travel impacts to the Friday evening commute, a Winter Weather Advisory may eventually be needed for portions of the area. Given the marginal snowfall, and that the event is still just over a day out from beginning, opted to hold off any any headlines to allow dayside to reevaluate. Conditions dry as the low pulls away Friday night, another round of arctic air filters in from the northwest. Lows Friday night and into Saturday morning will once again be in the teens most places. Wind chills Saturday morning may once again be in the single digits to near 0 for inland areas.
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&& .LONG TERM /SATURDAY THROUGH WEDNESDAY/...
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A mid 1040s high centered near Omaha on Sat builds S of the area thru Tue. It will be cold over the weekend with temps blw average. NW winds will keep wind chills in the single digits and teens on Sat, with wind chills dropping blw zero Sat ngt in the outlying areas. Temps aloft warm a bit on Sun, so slightly warmer but highs still likely aob freezing and wind chills in the teens and 20s. The NBM was followed. Heights rise Mon thru Wed with a further warming trend. By Tue, projected highs are a degree or two abv normal. Some rain is possible late Tue and Wed as GOMEX moisture begins to feed nwd into the region. This setup could produce a wintry mix at times across the interior, particularly Tue ngt. The NBM was followed.
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&& .AVIATION /09Z THURSDAY THROUGH MONDAY/...
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High pressure will pass off to the south today, while low pressure remains nearly stationary across the Canadian Maritimes. Mainly a VFR forecast. There could be a brief period of MVFR this afternoon along with a chance of flurries, especially north and west of the NYC terminals. WSW winds may increase a bit along the coast during the late morning and afternoon, but generally around 10 kt with a few gusts 15-17kt possible. The wind direction should also back to the SW today. Winds will then go light and variable for a time tonight before becoming NE less that 10 kt. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... A few gusts 15-17kt possible late morning/early afternoon. OUTLOOK FOR 06Z FRIDAY THROUGH MONDAY... Late tonight: VFR. Friday...IFR with snow developing in the morning continuing into the afternoon, ending in the early evening. NE-N wind gusts 20 kt in the afternoon and at night. Saturday-Sunday...Mainly VFR. N-NW wind gusts 25-30 kt Saturday and 20-25 kt on Sunday. Monday...VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 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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SCAs have been extended on the ocean, ending from west to east into the afternoon. The primary reason for the extension is due to lingering high seas, especially east of Fire Island Inlet. Sub SCA conditions are then expected on all waters by this evening, persisting through Friday morning. SCA conditions may redevelop Friday afternoon on the ocean with gusts 25-30 kt. A sca will most likely be needed on the ocean over the weekend, and possible on the protected waters with mrgnl winds. A period sub-sca cond late mon ngt into Tue, then winds and waves increase again late Mon into Tue, before subsiding again by Tue ngt.
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&& .HYDROLOGY... No hydrologic impacts are expected through the forecast period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory until 6 AM EST early this morning for ANZ331-332-335-338-340-345. Small Craft Advisory until 4 PM EST this afternoon for ANZ350- 353. Small Craft Advisory until 10 AM EST this morning for ANZ355. && $$ SYNOPSIS...JMC/DR NEAR TERM...DR SHORT TERM...DR LONG TERM...JMC AVIATION...JMC MARINE...JMC/DR HYDROLOGY...JMC/DR