Area Forecast Discussion
Issued by NWS Upton, NY

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277 FXUS61 KOKX 120837 AFDOKX Area Forecast Discussion National Weather Service New York NY 437 AM EDT Wed Jun 12 2024 .SYNOPSIS... High pressure remains in control through Thursday. A cold front will pass late Friday afternoon-evening. High pressure takes over this weekend into the middle of next week. && .NEAR TERM /THROUGH TONIGHT/... Remnants of the NE upper level low and troughing continues to fill in and push northeast into SE Canada later today. A weak shortwave attempts to slide in from the west later this afternoon. It is not out of the realm of possibility that his shortwave could help initiate a few isolated pop-up showers for the afternoon and for the very early evening. This is not officially in the forecast, but worth a mention. Otherwise, the dry airmass that has been in place does begin to undergo some slight modification later today and tonight. We should get one more fairly comfortable day in terms of fairly low humidity for this time of year before things to start to feel a bit more summerlike. Seasonable temperatures once gain with highs mainly in the upper 70s and lower 80s. Sea breeze enhancement takes place quickly in the afternoon with a weak pressure gradient in place and high pressure in control. Some higher res guidance does indicate a slight chance of shower or isolated t-shower activity across northeast sections with an sfc trough acting as a focus for some cumulus attempting to build. Overall another predominantly dry and seasonable day. For tonight it will be slightly warmer as the area undergoes the start of a return flow regime. Look for mainly clear skies, with perhaps a little bit of radiational patchy fog just before daybreak in the some of the interior valleys. Lows will be in the 60s for the city and the coast, with middle to upper 50s across much of the interior. && .SHORT TERM /THURSDAY THROUGH THURSDAY NIGHT/... On Thursday a semi-zonal upper level pattern takes place. A southwest flow will become more southerly with localized hybrid sea breeze interaction further east across the area towards afternoon. Look for a good deal of sunshine with just some scattered cumulus likely at 4 to 5 kft as indicated by BUFKIT forecast soundings. A SW flow at 850 mb gets 5kft temperatures climb to about 14 to 16 C. This will yield warmer temperatures region wide, with the warmer temperatures muted slightly further east across the CWA due to sea breeze development during the afternoon. Daytime max temperatures will be in the 80s for the most part CWA wide, with just some upper 70s across SE coastal communities. The winds may get gusty in the 20 to 25 mph range later in the afternoon for portions of southern Nassau, Queens, and Brooklyn as an Ambrose jet feature is suggestive on some guidance. For Thursday night with high pressure still in control look for mainly clear skies. A SW synoptic flow regime should keep temperatures above normal at night for the first time in awhile. Lows should range primarily from the middle 60s to lower 70s. && .LONG TERM /FRIDAY THROUGH TUESDAY/... A shortwave trough embedded in a longwave trough will lead to lowering heights on Friday before it becomes centered over the area Friday night. A frontal passage will occur with this shortwave, currently progged to pass through late Friday afternoon into Friday evening. Showers and thunderstorms are likely to occur in the afternoon and evening with the FROPA. The risk for moderate to heavy downpours in some of these thunderstorms is supported by models showing a surge of 1.5-2" PWATs being advected in ahead of the cold front from southerly flow with forcing coming from the frontal boundary. Currently projecting rainfall amounts anywhere from 0.5" to 1.5", with isolated higher totals possible in stronger thunderstorms. Long, skinny CAPE profiles with a deep warm cloud layer of 10,000 to 14,000 feet indicate some thunderstorms may have efficient rainfall processes. The good news is the progression of these storms is supposed to be on the fast side, which should limit significant flood concerns, with the most likely outcome being limited to minor urbanized/poor drainage flooding. Isolated instances of flash flooding in a strong thunderstorm can not be ruled out, but can not be stated with confidence, at this time. When Friday comes into view with convective-allowing models this afternoon and tomorrow morning, a better understanding of the flood risk will become apparent. The same goes for the risk of severe weather, with guidance from CAMs not yet within view. However, severe weather is still being considered a possibility. The frontal boundary along with warm surface temperatures forecasted to reach the low-80s to near 90 and dewpoints in the mid/upper-60s will aid in storm development. WHile the shortwave won;t center itself over the area until Friday night (after the frontal passage), there are some spokes of mid-level energy depicted by models that arrive ahead of the shortwave which should help increase lapse rates and provide somewhat of a cold pool aloft. The latest global and regional guidance have SBCAPE ranging between 1000-2000 J/kg, primarily in SW CT, NE NJ, and the Lower Hudson Valley, with the most significant CAPE in the Lower Hudson Valley. THis is the case for many other parameters such as the lapse rates, 45-55kt 0-6km Bulk, Shear and the Lifted Index. Thunderstorms will likely have less chance of becoming severe as they advance south and east, but again, confidence will increase as better resolution models come into view for this event. High pressure builds in from the NW during the weekend with dry conditions and more comfortable dewpoints. High temperatures will be pretty close or just above normal on Saturday and Sunday. A strong ridge will continue to build with warm aid advection aloft at 850mb, allowing for increasing temperatures which may reach the mid-90s next week and keep us dry for the rest of the long-term period. The only exception to this will be Monday night where the is a small chance for showers and thunderstorms stemming from a minor shortwave passing embedded within the larger longwave ridge. && .AVIATION /09Z WEDNESDAY THROUGH SUNDAY/...
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A weak surface trough will remain across the area through Wednesday. BKN VFR cigs during this time, generally 5-7 kft AGL. Light north winds this morning. Coastal sea breezes should develop by late morning, with speeds 10 kt or less. Light WSW flow Wednesday night. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Timing of sea breeze through Wednesday may vary by a few hours. OUTLOOK FOR 09Z THURSDAY THROUGH SUNDAY... MVFR possible in showers/tstms Friday afternoon and night, otherwise VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... Fairly tranquil conditions continue on the coastal waters with light winds and ocean seas generally 2 ft or less through tonight. A return flow gets established with a south to southwest flow regime later tonight and into Thursday. S winds start to increase, especially on the ocean late in the day Thursday and into Thursday night with gusts approaching small craft criteria Thursday night, especially out on the ocean. Wind gusts and seas on the ocean may come close to reaching advisory criteria on Friday, with sub-advisory conditions likely continuing through the remainder of the forecast period. && .HYDROLOGY... Showers and thunderstorms Friday afternoon/evening may produce 0.5- 1.5 inches of rain, with locally higher amts possible in stronger thunderstorms. Impacts will most likely be limited to minor urbanized/poor drainage flooding due to the progressive nature of storm cells, but an isolated flash flood instance can not yet be ruled out. && .TIDES/COASTAL FLOODING... There remains a low risk of rip currents at the ocean beaches today, with a moderate risk by Thursday afternoon for all ocean beaches. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JE/BR NEAR TERM...JE SHORT TERM...JE LONG TERM...BR AVIATION...BR MARINE...JE/BR HYDROLOGY...JE/BR TIDES/COASTAL FLOODING...