Area Forecast Discussion
Issued by NWS Upton, NY

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857 FXUS61 KOKX 131748 AFDOKX Area Forecast Discussion National Weather Service New York NY 148 PM EDT Sun Jul 13 2025 .SYNOPSIS... The region lies between a frontal system to the northwest and a departing high pressure area to the northeast. The associated cold front approaches Monday and moves across Monday night into early Tuesday. The frontal boundary then stays within the vicinity of the region through midweek. A cold front may approach the area by the end of the week. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Stratus deck will continue to plague most into this afternoon, with breaks at times, but the morning drizzle has come to and end and predominantly dry conditions expected across the region today. The area remains between high pressure southeast of Nova Scotia and a frontal system traversing slowly within SE Canada. NBM has been too aggressive with its POPs for showers and thunderstorms. CAMs show a general lack of convection in the area and lowered POPs from the blended guidance. Best chance of any activity is far NW locales, mainly Orange County, where late day shower or thunderstorm is possible. For temperatures, used the NBM but manually lowered for locations within Southern Connecticut and Eastern Long Island. These locations will be on the lower end of high temperatures in the upper 70s while the warmest spots are in NE NJ and portions of the interior with highs in the upper 80s. With the humid airmass, heat indices run a few degrees warmer than the actual temperatures. && .SHORT TERM /6 PM THIS EVENING THROUGH TUESDAY NIGHT/... For tonight, the flow becomes more southeast. Clouds remain abundant and some patchy fog and drizzle may develop along parts of the region. Otherwise, small chance of a shower or thunderstorm to the northwest by Orange County NY. Min temperatures were from NBM ranging only from the upper 60s to lower 70s. For early next week, frontal system from SE Canada approaches with an associated cold front. This cold front approaches from Monday and moves into the area Monday night. Chances for showers and thunderstorms increase across a larger fraction of the region. The front slows down as it exits early Tuesday. Continued chances for showers and thunderstorms. Downward trend in POPs Tuesday into Tuesday night as cold front pushes farther south of Long Island. Airmass gradually getting warmer early next week with synoptic flow becoming more southerly. Highs more in the 80s with some places reaching near 90 for Tuesday. Corresponding heat indices get more near the low to mid 90s, especially Tuesday. && .LONG TERM /WEDNESDAY THROUGH SATURDAY/... ***Key Points*** *While still some uncertainty, there is the potential for a heat wave to continue Wednesday through Friday for many areas with max h eat index values between 95 and 100 (2-day Heat Advisory Criteria) for Wednesday and Friday and 100 to 105 possible for Thursday (1-day Heat Advisory criteria). *Relatively active pattern with chances for several days of afternoon showers and thunderstorms. A frontal boundary will likely stall just offshore and linger in the area Wednesday into Thursday. A frontal system may then impact the area later in the week. Aloft, the pattern stays the same through the period. Although we are under some high heights, we are somewhat on the eastern end of a broad upper level trough centered over central Canada and few shortwaves likely pass through. With strong Bermuda high in place, a S/SW flow will allow plenty of moisture to be sent our way. This combined with above normal high temperatures brings some potential for a heat wave, with heat index of 95-100 currently expected Wednesday and Thursday, and 100 to 105 for many spots on Thursday. However, there still is uncertainty especially given the potential for convection and slight inconsistencies in a late week frontal system among the guidance. Too early to talk specifics when it comes to severe or flooding concerns with the aforementioned convection. These details will be ironed over the next few days. There is plenty of moisture around with pwats 1.50-2.00+ for much of the period so any convection that does develop will likely be able to produce heavy downpours. As for severe, while we are pretty unstable, shear looks weak through much of the period. && .AVIATION /18Z SUNDAY THROUGH FRIDAY/...
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Weak offshore high pressure drifts east through tonight, and remains offshore through Monday. MVFR ceilings remain across much of the area, with VFR east of the NYC terminals and into coastal Connecticut with a light southeast to south flow. By around 19Z ceilings are expected to improve to VFR at the NYC terminals. The improved conditions will be short-lived as ceilings lower to MVFR during the early evening, and then to IFR east of the NYC terminals late tonight. IFR conditions are possible late tonight into early Monday morning at the NYC metro terminals. Conditions improve to VFR around midday or into Monday afternoon at all the terminals. There is a lot of uncertainty with the timing of lowering conditions, and areal extent of IFR, and possible LIFR. Patchy drizzle and fog is also possible late tonight into early Monday morning. Light SE winds up to 10kt this afternoon becoming generally light and variable tonight. A more southerly flow develops Monday with speeds to around 10kt. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Amendments expected due to changes in flight categories through the forecast period with uncertainties of flight category changes and timing. .OUTLOOK FOR 18Z MONDAY THROUGH FRIDAY... Monday afternoon: MVFR ceilings possible early afternoon, then becoming VFR. MVFR possible in thunderstorms mid afternoon into the evening. A chance of thunderstorms overnight. A few storms could produce brief heavy rainfall late Monday afternoon into the evening. Tuesday-Friday: Mainly VFR. MVFR in showers or thunderstorms each afternoon and evening. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... Weak pressure gradient continues with sub-SCA conditions on all waters through midweek. A strengthening southwesterly flow ahead of an approaching cold front Thursday night will allow seas to build to 5 ft, especially from Fire Island to Montauk Point. Additionally, a relatively active pattern is expected next week with chances of afternoon showers and thunderstorms for several days. Winds and waves will be higher in any storms. && .HYDROLOGY... Possible nuisance flooding Monday into Monday night. Marginal risk for flash flooding. PWATS get slightly above 2 inches. Parallel flow low to mid levels allowing training of cells. HREF showing potential for hourly rainfall rates getting to around 1 inch per hour Monday evening. In the long term, localized hydrologic impacts are possible due to thunderstorms from Wednesday through next weekend. && .TIDES/COASTAL FLOODING... For Atlantic Ocean beaches, the rip current risk today and Monday is moderate with an onshore flow near 10 kt, a 3 ft swell from the southeast at a 7 to 8 sec, and added onshore swells, one of which is a long period swell. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...JM/JP NEAR TERM...JM/DR SHORT TERM...JM LONG TERM...JP/JT AVIATION...MET MARINE...JM/JP HYDROLOGY...JM/JP TIDES/COASTAL FLOODING...