


Area Forecast Discussion
Issued by NWS Upton, NY
Issued by NWS Upton, NY
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175 FXUS61 KOKX 040009 AFDOKX Area Forecast Discussion National Weather Service New York NY 809 PM EDT Thu Apr 3 2025 .SYNOPSIS... A warm front will move across and eventually north of the region into this evening. A cold front then slowly moves through tonight into Friday. The frontal boundary stalls, then returns north as a warm front and pushes through Saturday into Saturday night. The trailing cold front pushes through Sunday, followed by weak low pressure tracking nearby along the boundary on Monday. High pressure builds for mid week before pushing offshore by late Thursday. && .NEAR TERM /UNTIL 6 AM FRIDAY MORNING/... Warm front expected to move farther north and eventually north of the entire area tonight. A weakening cold front moves in late tonight. This will bring a higher chance and coverage of showers along with a few thunderstorms. Shower activity minimal thus far late this afternoon. Area starting to get more westerly component to winds. Warmer for western locations compared to eastern locations. Fog has begun development across eastern sections of the region, becoming dense in some locations. SPS out for patchy dense fog into early this evening for Southeast CT and Suffolk County Long Island. For tonight, expecting SW winds to decrease with a cold front moving in. This cold front is weakening as it moves in as parent low pressure fills in across Southeast Canada. Expecting the fog to linger around especially across Southern CT and Long Island. In addition, while the frontal forcing is weak, mid level positive vorticity advection with smaller embedded shortwave moves in. Upper level jet streak also moves north of the area with its right rear quad getting close to the region late tonight. This will enhance lift and with some ambient low level instability, a few thunderstorms will be possible. The convective coverage this evening is isolated to scattered at most with convection being mostly south of Long Island where greater instability will be located. The chances for showers expand across the entire region late tonight, becoming likely, with a slight chance of thunderstorms as well. Lows will not have a wide range, just upper 40s to mid 50s. Some drier air behind the cold front will allow for fog to become less expansive by early Friday. The rain increasing will also help mix out the low levels, allowing for fog to breakup. && .SHORT TERM /6 AM FRIDAY MORNING THROUGH FRIDAY NIGHT/... With slight ridging aloft and upper jet staying north of the area, the weak cold front moving through will slow down south of the region. Not much steering flow. Rain showers chances decrease Friday morning with drier air coming in on a NW flow. With weakening pressure gradient, do not expect much in the way of gusty winds. Some gusts near 15 to 20 mph along coast. High temperatures a blend of MAV and MET MOS, mainly in the low to mid 60s. Clouds overcast to start with some more breaks of sun for afternoon. Friday night, increasing clouds from west to east as frontal boundary to the south moves north as a warm front. Might even have some light rain developing with isentropic lift late heading into early Saturday morning. However, expecting much of the night to be dry. Some radiational cooling with light winds Friday evening before clouds increase, so have lows ranging from upper 30s to upper 40s. && .LONG TERM /SATURDAY THROUGH THURSDAY/... An Atlantic seaboard and Western Atlantic ridge will give way to a longwave trough during the period. Weak shortwave energy along with a warm front, then a cold front along with a wave of low pressure should bring rounds of unsettled weather for much of the weekend. As the longwave trough sets up in the east, shortwave energy may impact the area on Monday, and maybe towards the tail end of the period late Thursday, at least according to the GFS and the EC-AIFS. Other NWP guidance suggests it remains dry through the day Thursday. A warm front should lift northeast and through the region to begin the weekend. The timing of the warm front passing through remains in question, but model consensus is suggestive that the warm front lifts through Saturday night. Ahead of the warm front look for light rain, with perhaps a few moderate bouts during the day. As the warm front presses in look for a higher probability of fog across the region with some possible reduced visibilities into the day and early evening. The area should get into the warm sector, albeit briefly late Saturday night and into Sunday morning with a warmer WSW flow regime. The cold front will then push through sometime Sunday afternoon / early evening. The winds will turn to the W, then NW for Sunday night. The question is how far south does the cold frontal boundary get late Sunday and Sunday night. NWP consensus has the front remaining close enough to the region that the next impulse moves up along the boundary in response to shortwave energy, and higher PoPs coming back in for at least late in the day Sunday and Sunday night. During Monday the boundary is progged to get just off the coast, with PoPs for now confined to mainly eastern portions of the area. With the upper level trough pivoting through and some instability and a cold pool aloft have kept low end chance minimal PoPs for Monday night into Tuesday. A rather chilly Canadian based cP air mass will build for the mid week. Temperatures are expected to get below normal Tuesday night into Wednesday. Wind chill readings by late Tuesday night / early Wednesday morning may get down into 20s region wide with actual air temperatures near or below freezing across the entire area. Temperatures during the day Wednesday will struggle to get out of the 40s despite April sun. Another chilly wake up is anticipated for Thursday with the high settling over the area and a good radiational cooling set up anticipated. The high should then start to get further east on Thursday with a return flow setting up at the tail end of the period. && .AVIATION /00Z FRIDAY THROUGH TUESDAY/... A cold front will move across late tonight with high pressure building in for Friday. All terminals have improved to VFR except for KGON, where conditions remain LIFR. However, even here, conditions are expected to improve over the next few hours. Showers move in tonight in association with the cold front after 04Z. With conditions considerably improved and guidance suggesting minimal impact with the showers in regards to flight categories, have kept VFR in the forecast. However, brief MVFR conditions with the showers overnight is still possible, mainly for clouds. SW winds this evening 10 kt or less shift to the NW 5-10 kt with cold fropa late tonight and increase to either side of 10 kt Fri morning. Occasional gusts possible early afternoon on Friday to 20 kt, but did not look frequent enough to include in TAFs. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Generally a VFR forecast, but brief MVFR possible with showers that move through after 04Z. Therefore, amendments are possible, especially after 04Z. .OUTLOOK FOR 00Z SATURDAY THROUGH MONDAY... Friday Night: VFR. Saturday: Showers likely. MVFR to IFR expected in the afternoon and at night. SE winds G15-20kt. Sunday: Chance of showers. Any IFR cond early should become MVFR. SW winds G15-20kt. Monday: Chance of showers with MVFR/IFR cond possible. Tuesday: VFR. WNW winds G20-25kt. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... The warm front lifts north of the waters into this evening. Marine dense fog for waters surrounding Suffolk County NY, could potentially get into western waters tonight as well. Small craft advisories remain and have been extended in time for the ocean zones. Winds forecast to lessen this evening, keeping SCA conditions just mainly on the ocean after 8PM. The SCA conditions stay on the ocean through all of tonight due to mainly ocean seas. Winds trend down eventually below SCA levels tonight and remain below SCA levels Friday through Friday night. Ocean SCA seas still expected into Friday, with Sandy Hook NJ to Fire Island Inlet ending at 10AM, Fire Island Inlet to Moriches Inlet ending at 2PM and Moriches Inlet to Montauk Point ending at 4PM. The southerly wave component on the ocean has trended longer with duration of SCA seas with both NWPS and Wavewatch, prompting the further increase in SCAs. All waters below SCA levels Friday night. Sub advisory conditions should prevail for the most part through Saturday night. On Sunday a S to SW flow strengthens ahead of a cold front with small craft conditions prevailing on the ocean, with marginal small craft conditions possible on the ocean and only for the eastern and south shore bays of LI. Elevated seas are likely to continue much of the ocean through at least Monday night. Behind a cold front Tuesday look for small craft conditions to continue on the ocean, and to develop on the non- ocean waters with a WNW wind increasing. A period of gales cannot be ruled out later Tuesday and Tuesday night. && .HYDROLOGY... Minor flooding possible late tonight into early Friday for western coastal sections around NYC Metro with any heavy showers and thunderstorms. Otherwise, no hydrological impacts are anticipated through the period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...Dense Fog Advisory until 6 AM EDT Friday for ANZ331-332-340- 345-350-353. Small Craft Advisory until 4 PM EDT Friday for ANZ350. Small Craft Advisory until 2 PM EDT Friday for ANZ353. Small Craft Advisory until 10 AM EDT Friday for ANZ355. && $$ SYNOPSIS...JE/JM NEAR TERM...JM SHORT TERM...JM LONG TERM...JE AVIATION...JP MARINE...JE/JM HYDROLOGY...JE/JM