000
FXUS61 KOKX 031450
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
950 AM EST Wed Jan 3 2024

.SYNOPSIS...
High pressure south of the area shifts offshore tonight with a
weak frontal system moving through on Thursday. High pressure
starts to build in Thursday night and remains in control into
Saturday morning. A storm system impacts the area Saturday
evening through Sunday. High pressure builds in to start next
week, followed by another storm system for the middle of next
week.

&&

.NEAR TERM /THROUGH TONIGHT/...
-- Changed Discussion --
Increased cloud cover inland through this afternoon as surface trough and associated cold front slowly approach to the northwest. Otherwise only made updates for current conditions. Dry and cool conditions are expected to continue today with high pressure positioned south of the area gradually sliding offshore during the day. Highs today will be around average with temperatures in the low to middle 40s. Mid-level troughing associated with the cold front will force a weak wave of low pressure to develop to the south of the area. This may result in the development of some light snow showers late in the night, mainly along the coast, though dry low levels may prevent any precipitation from reaching the surface. Lows tonight will be in the middle 20s to lower 30s.
-- End Changed Discussion --
&& .SHORT TERM /THURSDAY THROUGH FRIDAY/... The weak low pressure system to the south continues to shift offshore during the day on Thursday with any light showers along the coast dissipating by early afternoon. There may be some additional light rain or snow showers with the FROPA during the morning and early afternoon on Thursday, though there is only a slight chance. The mid-level troughing pushes the front and low pressure offshore by Thursday night with a strong 1030 high pressure building into the area from the west. The tight pressure gradient between the departing low and the approaching high will bring breezy conditions Thursday evening and into the first half of the overnight with NW winds 10-20 mph with gusts upwards of 30 mph along the coast. Gusts diminish by Friday morning with mostly clear skies and cold conditions with highs only in the middle to upper 30s. && .LONG TERM /FRIDAY NIGHT THROUGH TUESDAY/... *Key Points* * A coastal storm is expected to impact the area Saturday evening through Sunday. Too early to be specific with potential snow amounts and precipitation types. Wind and coastal flooding impacts will be possible as well. * Another area of low pressure for the middle of next week may bring wind and flooding impacts. There has not been much change from the previous forecast. Quiet weather is expected Friday night through early Saturday as high pressure remains in control as it shifts offshore. Attention then turns to the first of two strong systems to impact the area in the long term. Deterministic and ensemble guidance continue to be in agreement on an area of low pressure passing close enough to our south and east to bring impacts this weekend. Differences still exist in exact center track which is expected this far out. This will impact what precip types are seen across the area. The latest ECMWF and Canadian have the low tracking right near the 40N/70W benchmark, with the GFS quite a bit farther south and east. The trend in the ECMWF Ensemble and the GEFS has been slightly farther southeast, with the GEPS actually trending slightly closer to the coast. With this event still several days away, small wobbles in model tracks will continue run to run. Something to note though is the weakening trend in the GFS. This has to do with the shortwave lifting out of the southwest CONUS becoming almost flat by the time it reaches the northeast. This can be blamed on the interaction with a piece of energy behind the trough moving into the northwest CONUS Thursday night. This trend is something that needs to be watched over the next few days and would lead to less impacts. As mentioned, it is too early to talk specific precip types, but confidence in accumulating snow is highest across the Lower Hudson Valley and southern CT given a blend of current model tracks. The Weather Prediction Center has a 50 to 70% chance of these areas exceeding .25 inches of liquid equivalent of snow/sleet. This lowers to about 10 to 30% for the NYC/NJ metro area and Long Island. Winds with this system could briefly touch advisory level, mainly across Long Island. There may also be minor coastal/shoreline impacts, including scattered dune erosion. There is another area of low pressure that will impact the area in the long term during the middle of next week. There continues to be very good agreement with the guidance with this system as well, especially for being this far out. A closed upper level low and associated surface low will lift from the southern CONUS and track west of the area. The main concerns with this system at this time are the strong winds and heavy rain. The area could potentially be in between roughly a ~980mb low and ~1034mb high. This very tight pressure gradient brings the potential for strong winds. This system also brings plenty of moisture with it and the potential for heavy rain. The flooding threat would be greatest over the interior sections where, even outside of the amount of rain that falls, an existing snowpack may be present and rapidly melt on top of already- saturated soils. The LREF currently has a an 85% chance across the whole area of seeing greater than 1 inch of rain in any 24 hour period with this storm and a 25 to 40% chance of seeing greater than 2 inches. && .AVIATION /15Z WEDNESDAY THROUGH SUNDAY/...
-- Changed Discussion --
High pressure centered S of the region shifts offshore today. A cold front tracks through late Thursday morning. Mainly VFR through the day. Uncertainty remains around the coverage and duration of any MVFR cigs for this evening and overnight. WNW winds less than 10 kt shift to a more W/WSW wind this afternoon before decreasing to around 5 kt tonight. This persists until the frontal passage Thursday morning when winds increase to 10-15 kt G20-25 kt and shift to the NW. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... No unscheduled amendments expected through this afternoon. Amendments may be needed late this afternoon and evening for brief MVFR ceilings. OUTLOOK FOR 12Z THURSDAY THROUGH SUNDAY... Thursday: Mainly VFR. Chance of MVFR in any -RA/-SN showers early, improving to VFR. NW winds 10-15G20-25kt. Thursday night: VFR. NW winds 10-15G20-25kt. Friday: VFR. NW winds G20kt possible for the AM push. Saturday: VFR becoming IFR or lower Sat ngt in snow and/or rain. Increasing E/NE winds. Sunday: Rain/snow ending as snow. IFR or lower possible. Winds becoming N. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
-- End Changed Discussion --
&& .MARINE... Quiet conditions over the waters through Thursday afternoon. Winds increase late Thursday as low pressure passes well offshore and high pressure builds in from the west. Small Craft Advisories look likely on all waters Thursday afternoon through Thursday night with 25 to 30 kt wind gusts. Wind gusts on the ocean waters may briefly approach or exceed 35 kt. Ocean seas will also likely reach 5 to 6 ft. Winds should begin weakening on Friday, but some lingering 25 kt gusts are possible on the ocean. Seas should subside below 5 ft by Friday afternoon. Conditions are then expected to be below SCA levels on Saturday. A storm system impacting the waters Saturday evening through Sunday will bring a chance of gales across all waters during the this period. HWO mention of this potential continues. Ocean seas during this time could reach 10 ft. After the system moves east, 5 ft waves could linger on the ocean waters through Monday. Another storm system is expected during the middle of next week. This also has the potential to bring gales to the waters and possibly even storm force gusts to the ocean waters. It is too far out in time and confidence is too low for a mention in the HWO. && .HYDROLOGY... There are no hydrologic concerns through the end of the week. A liquid-equivalent 0.75 to 1.50 inches of precipitation is anticipated from Saturday evening through Sunday. Since some of this may be in the form of snow, impacts may be minimal. A greater flooding threat (especially rivers) may exist starting next Tuesday. This will partially depend on what materializes this weekend. Regardless, soils will remain nearly saturated leading up to the event. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JT/MW NEAR TERM...MET/JT/MW SHORT TERM...MW LONG TERM...JT AVIATION...DR/MW MARINE...JT/MW HYDROLOGY...JT/MW