889
FXUS61 KOKX 222016
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
416 PM EDT Sat Mar 22 2025

.SYNOPSIS...
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A cold front moves across this evening. High pressure builds in for Sunday. A frontal system moves across Sunday night into Monday. Weakening low pressure will track across southeastern Canada Monday night into Tuesday night, with another weak low passing to the south late Tuesday night into Wednesday. High pressure then builds in to the south for the end of the week. A frontal system may impact the region Saturday.
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&& .NEAR TERM /UNTIL 6 AM SUNDAY MORNING/...
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500mb trough continues to approach from the west late this afternoon. Southerly flow advecting in warmer air. Surface pre-frontal trough moves across late this afternoon, with more westerly component in winds after its passage. Farther west a cold front will be approaching with associated parent low well within Southeast Canada moving northward in Quebec. Actual observed Doppler radar reflectivity indicates echoes of 10 to 30 dBZ range traversing the region but dry low levels preventing rain from reaching the surface. More rain showers expected towards the evening. BUFKIT models show late day mixing when winds veer to more WSW. The high temperature could very well get achieved late in the afternoon with this westerly flow adiabatic mixing down to the surface. For tonight, mid level trough moves across with cold front moving across. This will be during the evening hours. Showers early then dry late evening and overnight. Cold air advection late evening and for rest of tonight with NW gusty winds. 500mb trough axis moves across this evening. This moves east of the area thereafter through the rest of tonight. Region remains in 500mb NW flow. Some positive vorticity advection in the mid levels along with coherent discrete echo reflectivity within mesoscale models from multiple model runs so chance POPs for entire region and some likely POPs mainly for Orange County before 8PM. Narrowed the chance POPs to occur mainly 6-10PM. Cold front moves across this evening generally between 8 and 11PM. Cold front expected to be southeast of Long Island after 11PM and then the front will continue moving out into the Atlantic overnight. Winds at the surface transition from gusty WSW ahead of the cold front to more gusty NW flow behind the cold front. Dry and cold air advection then increase. Models indicate a significant 850 mb temperature decrease of around 6 to 7 degrees C between 8PM tonight and 2AM Sunday. 850mb temperatures thereafter going into early Sunday morning rise slightly for western half of the forecast region and remain nearly constant for eastern half of the forecast region. With the gusty winds, expect a less vast range of low temperatures. The lows will only vary from mainly the mid 20s for much of the interior to the lower 30s along the coast. This used a blend of MAV/MET/consensus of raw model data with slight adjustments up near Westhampton NY.
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&& .SHORT TERM /6 AM SUNDAY MORNING THROUGH MONDAY/...
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Brief mid level ridging Sunday and surface high pressure moving across will maintain dry conditions during the day. NW flow remains gusty to start the day but will decrease during the day as the pressure gradient weakens. Models convey warmer air advecting in at 850mb. This will set up an inversion. Less vertical mixing is expected especially as winds become lighter. The max temperatures forecast Sunday are expected to be around 10 degrees cooler than the previous day max temperatures. Used the NBM for high temperature forecast. Also mitigating the high temperature will be increasing clouds during the day as the high pressure will be relatively weak. Upstream higher level clouds will expand and move into the local region for the afternoon but still expect substantial sunshine overall. Incoming mid level trough for Sunday night with closed off low moving east within Great Lakes. At the surface, there will be a surface low moving eastward through the Great Lakes. An associated warm front approaches from the south and west. Strong mid level shortwave moves across early Monday and then east of the region Monday afternoon. However, overall in the larger scale, region remains in the longer wavelength trough with that closed low moving into SE Canada, near Ontario and Quebec border. At the surface, warm front slows down as it moves across with a weak low pressure area developing along it. The low pressure makes its way across the area Monday afternoon with a cold front to the south of it. Surface winds go from southerly Sunday night into early Monday to more southwesterly Monday afternoon. Surface and low level winds become more southerly Sunday evening across the region. These winds will increase Sunday night into Monday morning. The approaching system low level jet comes across for early Monday morning. Low level warm air advection expected Sunday night into Monday. Precipitation returns, more of a stratiform overrunning rainfall. Precipitation starts mainly late evening Sunday night. This will be primarily light. Locations within the northern half of the forecast region are forecast to have enough wet bulb cooling for a mix of rain and snow with some periods of all snow before 5AM Monday. Warmer temperatures and boundary layer along the coast keeps precipitation all rain for southern half of the forecast region. As this low level warm air advection increases, more early Monday, the precipitation forcing increases. This will make for a steadier rainfall along the coast. Bulk of the rain is expected early Monday, with rain being the dominant weather feature Monday morning. Some interior locations will have a wintry mix, around 5AM to 10AM Monday but those locations are also expected to warm up enough to make for all rain by late Monday morning. Frontal system precipitation closes out late Monday morning through Monday afternoon with rain. Rain likely lingers across Southern CT and Long Island late afternoon into early Monday evening with lesser chances of rain to the west across the rest of the forecast region. Any snow for the event confined to the interior with potential for near 1 inch or less of snow. Any ice accumulation just potential to be a glaze. Uncertainty with low level warm layer at 850mb early Monday, NAM higher temperature, GFS less temperature. Used a blend with thicknesses for that precipitation type forecast.
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&& .LONG TERM /MONDAY NIGHT THROUGH SATURDAY/...
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No significant changes to the extended with this update as generally quiet weather persists through the period. And with no significant variance in the guidance, and targets of opportunity, mainly used the NBM deterministic guidance. However, for the possibility of windier conditions Monday night into Tuesday, and Wednesday night into Thursday, leaned toward the higher 75th and 90th percentiles for winds and gusts. Temperatures will be generally near normal, with slightly above normal lows Monday night, and with the approach of a warm front late in the week, temperatures may be 5 to near 10 degrees above normal Thursday night into Saturday. Although there is uncertainty as to where the warm front will set up by late in the week as the associated low will be over the plain states. A upper level high amplitude longwave trough will be over the eastern states Monday night into Wednesday night with a high amplitude ridge over the western states. The trough begins to move offshore late Wednesday night as heights rise Wednesday night into Saturday as the upper ridge moves slowly eastward, and gradually weakens next Saturday. Late Tuesday night through Wednesday there is a chance of precipitation as energy moves into the base of the upper trough, and surface low pressure passes to the south. Any precipitation will be light, with rain along the coast, and snow inland. Then dry weather is expected Wednesday night into next Saturday as the ridge and surface high pressure dominate. And the next chance of precipitation will be later Saturday with a warm front, and forcing along this boundary. Although there is uncertainty as to where this will set up with the surface low well to the west.
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&& .AVIATION /20Z SATURDAY THROUGH THURSDAY/... A cold front passes through this evening. VFR. Mainly SW-WSW winds with gusts around 25kt this afternoon. Winds shift NW and increase by a few kt this evening. Winds then diminish late tonight and through the day Sunday. PROB30 for showers with brief MVFR vsbys for all but KISP and KGON late day/early evening. Any showers before around 23z likely would not cause vsby restrictions. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... A brief shower will be possible as early as 19z, but likely would not cause vsby restrictions before 23z. Chance that conds remain VFR in in any shower. PROB30 timing and subsequent wind shift to NW may be off by an hour. .OUTLOOK FOR 18Z SUNDAY THROUGH THURSDAY... Sunday aftn/eve: VFR. Late Sunday Night and Monday: Becoming IFR with rain. Possible onset as snow for KSWF. S winds G15-25kt, strongest near the coast on Monday. Tuesday: VFR. WSW winds G20 kt possible. Wednesday: MVFR possible. Chance of showers. Thursday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE...
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Small craft advisories, SCAs, are in effect for the ocean and stay in effect through Sunday morning. Some lingering SCA ocean seas and some lingering SCA wind gusts Sunday afternoon east of Fire Island Inlet, so that segment SCA goes until 3PM Sunday. Non-ocean waters have SCA in effect from 8PM tonight until 9AM Sunday and then all non-ocean marine zones except for NY Harbor and Western LI Sound go until 12PM Sunday for their SCA. Brief sub-SCA conditions forecast for the waters Sunday afternoon for most waters, after 3PM Sunday afternoon, east of Fire Island Inlet on the ocean and that continues through much of Sunday night. However, SCA potential increases late Sunday night for parts of the ocean. Most waters in SCA range for wind gusts Monday. Ocean seas rise back to 5 to 7 ft late Sunday night into Monday. Small craft advisory level ocean seas will likely continue Monday night into Tuesday evening with a weakening southwest flow. Then winds and seas will be below advisory levels across the forecast waters Tuesday night through Thursday. With an increasing southwest flow late Thursday night ocean seas may build to near 5 feet.
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&& .HYDROLOGY...
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Low pressure system tonight, less than a tenth of an inch of rain. Low pressure system late Sunday night through Monday evening, around 0.25 to 0.5 inch of rain/liquid equivalent. No hydrologic impacts expected through the end of next week.
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&& .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from 8 PM this evening to noon EDT Sunday for ANZ331-332-340-345. Small Craft Advisory from 8 PM this evening to 9 AM EDT Sunday for ANZ335-338. Small Craft Advisory until 3 PM EDT Sunday for ANZ350-353. Small Craft Advisory until noon EDT Sunday for ANZ355.
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&& $$ SYNOPSIS...JM/MET NEAR TERM...JM SHORT TERM...JM LONG TERM...MET AVIATION...JC MARINE...JM/MET HYDROLOGY...JM/MET