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FXUS61 KOKX 261824
AFDOKX

Area Forecast Discussion
National Weather Service New York NY
224 PM EDT Fri May 26 2023

.SYNOPSIS...
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High pressure will continue building in from the Great Lakes going into this holiday weekend. The high pressure area will begin to weaken and shift offshore towards the latter half of the holiday weekend. A backdoor cold front residing just north and northeast of the area will likely move through Monday afternoon into Monday Night, otherwise high pressure will remain in control Tuesday into the end of next week.
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&& .NEAR TERM /THROUGH TONIGHT/...
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Thermal trough development this afternoon causing a temporary weakness in the surface high pressure area. However, with ridging still aloft as a shortwave trough pushes south of Long Island, cloud coverage remains small with mostly sunny conditions prevailing. Northerly surface winds have prevailed across most locations thus far, with more southerly winds expected to develop by late this afternoon with sea breeze development. For this afternoon, forecast remains on track with again just some slight adjustments to temperatures, dewpoints, and cloud coverage to better match with observed trends. Most locations will have high temperatures in the lower 70s with some mid 70s for parts of Northeast NJ. For tonight with the thermal trough dissipating as temperatures cool, pressure tendency increases, allowing for subsidence. High pressure will build in more tonight, and as a result, winds decouple and sky conditions will remain mostly clear. This will provide ideal radiational cooling conditions. For the forecast lows tonight, used a blend of 3/4 cooler MAV MOS and 1/4 warmer MET MOS with a more vast range of temperatures from the upper 30s in the Pine Barrens of Long Island to upper 50s within parts of NYC.
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&& .SHORT TERM /SATURDAY THROUGH MONDAY/... Upper ridging surface/aloft remains in control across the Great lakes into NE US through the holiday weekend. This will keep an anomalous cutoff upper low and coastal low suppressed across the SE US/Tennessee Valley states through the holiday weekend. Moderating Canadian high pressure will dominate our weather pattern through this period with tranquil conditions. General theme will be a weak synoptic flow, giving way to SE sea breeze development each afternoon. With plenty of sunshine, moderating airmass, and deep mixing each day, temps should warm up quickly each morning before halting/dropping after afternoon sea breeze frontal passage. Sea breeze development will likely be by early afternoon for south coasts, and quite progressive well inland each afternoon based on the increasing land/ocean temp differential each day and with broad easterly flow regime around the southeast low just to the south of the area. Models indicating flow between meso-high and weak interior troughing will likely result in a weak NE/E flow to start Saturday, with hybrid E/SE sea breeze working through most of the area in the afternoon. This will likely limit temps to the lower 70s along the south coasts (60s along the immediate ocean shoreline), increasing to upper 70s well N&W of NYC with later/weaker sea-breeze and deeper mixing. Airmass continues to moderate on Sunday, with orientation of high likely resulting in more of a weak S/SW synoptic flow to start , but once again early and well inland progressing sea breeze development. Temps should be a couple of degrees warmer based on airmass moderation. Areas well N&W of the NYC/NJ metro will have the warmest temps with temps rising into the lower 80s, while closer to the south coast, temps should be limited to the lower 70s-75 (60s along the beachfront). Models in fairly good agreement with some increasing high clouds Sunday Night into Monday as the closed SE low begins to drift east towards the SE US coast, but any shower activity should remain suppressed to the south. Potential for stratus development along the coast Sunday Night into Monday morning from persistent onshore flow and strengthening maritime inversion. Timing of backdoor cold front will have to be refined, posing some uncertainty on temps. Similar weak synoptic flow to start the day as Sat and Sun, and likely a couple degrees warmer as airmass continue to moderate, but timing of backdoor front will be critical with Canadian maritime airmass in its wake quickly dropping temps several degrees on a gusty easterly wind behind it. So could quickly go from warm to chilly for coastal areas Mon aft/eve, particularly eastern shoreline areas. Will stay close to NBM for highs ahead of backdoor front, with lower to mid 70s for south/east coasts, lower 80s NYC/NJ metro, to 85 for areas well N&W of NYC. && .LONG TERM /MONDAY NIGHT THROUGH THURSDAY/... No major changes to the forecast from Monday night through next Thursday. A blocking pattern will persist over the eastern CONUS with ridging aloft and dry conditions through the period. High pressure will likely be centered just off the New England coast Monday night into Tuesday. This will help push a backdoor cold front across the area with a cooler E-NE flow. Temperatures should be at least 5 to 10 degrees lower than those observed on Memorial Day, with highs in the upper 60s and lower 70s near the coast and middle 70s across the Lower Hudson Valley. The surface high then builds westward Wednesday. Temperatures will begin to warm back into the lower 80s inland and middle to upper 70s most elsewhere. Some coastal locations may struggle to rise out of the lower 70s due to onshore flow. Much of the guidance then signals for the high to retrograde westward with a thermal trough possibly setting up over the area on Thursday. The NBM has been consistent with signaling warm temperatures across much of the area with highs in the middle to upper 80s from the NYC metro on north and west. Immediate coast locations could be cooler in the upper 70s and low 80s. These warmer temperatures are supported by NW flow aloft and 850 temperatures 16-18C. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/...
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VFR as high pressure remains in control through the weekend. Northerly flow and deep mixing will likely delay the seabreeze to late afternoon/early evening for the coastal terminals. Elsewhere, N winds will generally be at 10 kt or less with occasional gusts 15-18kt early. Winds will then go light and variable tonight, becoming light NE after 12Z Saturday, then SE by afternoon at 10 kt or less. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Timing of seabreeze could be delayed by 1-2 hours. OUTLOOK FOR 18Z SATURDAY THROUGH WEDNESDAY... Saturday-Wednesday: VFR. E winds G15-20kt Monday and Tuesday. 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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Conditions are expected to remain below SCA thresholds going into the holiday weekend. The Sub-SCA conditions are generally expected through Tuesday under a weak pressure gradient under high pressure. The one exception will be Monday aft into Monday Night, with potential for a brief period of marginal SCA gusts and increased seas behind a backdoor cold frontal passage. This will be something to monitor as this will likely be an active day for recreational boating activity. Additionally, the sub 60 degree water temperatures can quickly cause hypothermia to anyone immersed in the water. At these water temperatures, the average submerged person could lose dexterity within minutes and be unable to accomplish simple tasks. Anyone planning to recreate on small boats, canoes or kayaks this holiday weekend should plan accordingly and use extreme caution to avoid this threat.
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&& .HYDROLOGY... The prolonged stretch of dry weather continues through the entire forecast period. && .TIDES/COASTAL FLOODING...
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There is a moderate risk of rip current development today with 3-4ft@9 sec period ESE swell, enhanced by afternoon SE sea breeze development. A moderate risk of rip current development is likely to continue Saturday through Monday with a persistent 3 ft@7-8 sec SE swell, and afternoon S/SE sea breeze development. Rip current activity will likely be enhanced in vicinity of groin, jetties, and piers through this period with E>W sweep of waves.
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&& .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...DS/NV NEAR TERM...JM/NV SHORT TERM...NV LONG TERM...DS AVIATION...DW MARINE...JM/DS/NV HYDROLOGY...DS/NV TIDES/COASTAL FLOODING...