Area Forecast Discussion
Issued by NWS Upton, NY

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260 FXUS61 KOKX 050810 AFDOKX Area Forecast Discussion National Weather Service New York NY 410 AM EDT Wed Jun 5 2024 .SYNOPSIS...
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High pressure moves farther out into the Atlantic today as a warm front approaches the waters. This warm front moves in tonight and then eventually northeast of the region along with the associated cold front and low pressure on Friday. A broad area of low pressure meanders nearby over southeast Canada this weekend and into early next week.
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&& .NEAR TERM /UNTIL 6 PM THIS EVENING/...
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Still more low stratus than fog with current observations. Fog may very well be more patchy in coverage. From the morning into the start of the afternoon, the low clouds and fog will be slower to dissipate for Long Island and to the south but expecting a decrease in coverage for the latter half of the morning. In the afternoon, any remaining fog burns off and low clouds scatter out for most locations expect along immediate coastline. Only other weather feature for the afternoon into this evening will be pop up showers and thunderstorms. These will be forming well ahead of an approaching warm front. With combination of where surface based CAPE will be relatively highest (up to a few hundred J/kg) and where low level winds will exhibit more convergence, that will be the western extremes of the region. That is where there will be a chance for showers and thunderstorms with otherwise in the nearby vicinity to the east, a slight chance of showers and thunderstorms. Expecting any convective activity to stay primarily to the north and west of NYC. With mainly a dry day expected, high temperatures away from the coast are forecast to rise into the low to mid 80s with the rest of the area in the 70s. High temperatures forecast were from the NBM.
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&& .SHORT TERM /6 PM THIS EVENING THROUGH FRIDAY NIGHT/...
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With warm front and trough of low pressure moving in from the south and west tonight, would expect rain showers to increase in coverage. The passage of the warm front will make for a warm and humid airmass to incorporate the area. The forcing is not too strong and along with marginal elevated instability, just left the thunderstorm mention of slight chance. Low level omega increases more Thursday and with more CAPE (up to around 1000 J/kg), will have a greater chance of thunderstorms. Otherwise, showers are expected for much of Thursday. For Thursday night, the shower and thunderstorm activity is expected to decrease with the low and storm system passing farther east of the region. Mainly dry conditions expected for Friday and Friday night. There could be a pop-up shower or thunderstorm across the interior Friday afternoon into early Friday evening with upper level disturbance aloft with the cutoff mid level low and its associated cold pool. Mid 70s to lower 80s for max temperature forecast Thursday and nearly same range for Friday, but a greater fraction of the region has lower 80s compared to the previous day. High PWAT airmass still indicated by models with values up to near 2 inches for Thursday. This will make for heavy downpours at times. See hydro section for more details.
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&& .LONG TERM /SATURDAY THROUGH TUESDAY/...
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A relatively unsettled period this weekend into early next week with an upper low cutting off and meandering over the Great Lakes region and southeast Canada much of the time, with multiple vorticies rotating around it that may periodically enhance rain chances locally. The broad low nearby likely instigates diurnal shower activity with varying coverage each day, especially inland. As the cold pool moves aloft, also can`t rule out the possibility of thunderstorms with added instability. Global guidance continues to offer differing solutions with any potential vorticies however and this will need to be resolved for further clarity on when rain chances will be highest. Temperatures, while hampered by cloud cover and rain at times, should still manage to get into the 70s and lower 80s most afternoons, or about typical for this time of year. For now, continued to cap PoPs at 50%, otherwise, national blend was followed with subtle adjustments.
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&& .AVIATION /08Z WEDNESDAY THROUGH SUNDAY/...
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High pressure shifts farther offshore today ahead of an approaching warm front from the southwest. The front lifts through the region Thursday morning. Low stratus, mist, and potentially fog develop early this morning with the persistent onshore flow. IFR cigs have begun to develop as of 730Z, and should spread to most other terminals over the next hour or two, then IFR or lower cigs and vsbys thru at least 12Z. Improvement into mid morning, but could linger into late morning for some. VFR this afternoon, before conditions lower to IFR or below once again tonight with showers developing. Embedded thunder can`t be ruled out overnight into Thursday morning, but chance is too low to include at this time. Southerly flow persists thru the forecast, speeds at or under 10 kt. NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Lower confidence on timing of sub VFR conditions this morning and may be off by a couple of hours. Amendments possible. Timing of category declines and SHRA late this evening may be off by a few hours. Isolated thunder possible overnight into Thursday morning. OUTLOOK FOR 06Z WEDNESDAY NIGHT THROUGH SUNDAY... Late Tonight: IFR or lower with SHRA. Thursday: MVFR or lower possible in showers and thunderstorms, mainly during the daytime hours. Friday: Chance of MVFR with showers and possible thunderstorms. Saturday/Sunday: Chance of MVFR in showers. 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 on the forecast waters remain below SCA thresholds today through tonight. For Thursday through Friday night, conditions could become marginal for SCA on the ocean. Otherwise, non-ocean waters look to remain below SCA thresholds. Conditions are expected to remain below SCA levels through the weekend.
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&& .HYDROLOGY...
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Rainfall amounts of 0.50 to 1.00" with localized higher amounts are expected tonight into Thursday. Minor nuisance poor drainage flooding will be the primary threat especially in urban and low lying areas.
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&& .TIDES/COASTAL FLOODING... With the approach of a new moon this week, astronomical levels are on the rise. A southerly, then southeasterly, flow will also support increasing surge this week. This should be sufficient to get some of the vulnerable locations along the western LI Sound and the South Shore Bays at or just above minor flood benchmarks. A Coastal Flood Advisory remains in effect for coastal Fairfield, Westchester, and Nassau for this evening`s high tide, with a Coastal Flood Statement in place for coastal Queens, where the most vulnerable spots may see brief minor flooding. Based on latest trends, this may have been more of a statement level event tonight as water levels will likely only get to around minor flood benchmarks. The persistent flow and astronomically high tides will likely lead to additional minor flooding in subsequent evening high tides into late this week. There is a moderate rip current risk on the ocean beaches through Thursday due to building seas and a strengthening southerly flow. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JM/DR NEAR TERM...JM SHORT TERM...JM LONG TERM...DR AVIATION...DR MARINE...JM/DR HYDROLOGY...JM/DR TIDES/COASTAL FLOODING...