Area Forecast Discussion
Issued by NWS Upton, NY

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721 FXUS61 KOKX 301818 AFDOKX Area Forecast Discussion National Weather Service New York NY 218 PM EDT Mon Jun 30 2025 .SYNOPSIS... A stationary front will remain nearby today, before lifting north as a warm front tonight into Tuesday. A cold front approaches later Tuesday and pivots through late Tuesday night into Wednesday morning. A cold front approaches and moves through late Thursday into Thursday night, followed by high pressure returning Friday into next weekend. && .NEAR TERM /THROUGH TONIGHT/... Expect a typical warm and humid summer day region wide. The region will be just north or along the northern periphery of a stalled frontal boundary to the immediate south. Dew point readings will be primarily in the middle and upper 60s through the early afternoon. A sea breeze gets going for the afternoon and will usher in slightly higher moisture values with dew points approaching 70 late in the day and evening along far southern locations. Forecast soundings are suggestive of a fair amount of instability for today. However there appears to be a lack of a focusing mechanism for convection for much of the day. Towards late in the day (around or shortly after 20z) a few of the convective allowing model guidance (CAMs) hint at convection attempting to initiate along a convergence zone for the SW portion of the CWA. Have slight chance to low end chance PoPs towards Staten Island and southern portions of NE NJ with the possibility of a few late day showers / t-storms. Otherwise it should be a mainly dry day, just seasonably warm and humid. Just south of the frontal boundary in the warm sector dew point readings are even higher, mainly in the 70s. During tonight NWP is confident that the warm front lifts north. As it does so the chances for scattered showers and a few thunderstorms increases. The chance will be relatively higher for the western half of the area. Precipitable water values get to climatologically significant values, above 2 inches, and to around 2.25 inches after midnight. The CAM guidance is disagreeing on the extent of coverage, but any showers and stronger storms could put down a quick inch plus of rain locally due to high instantaneous rainfall rates. After 06z the entire region goes to chance PoPs with chance thunder with the warm front pushing north into the region and a southerly flow becoming more southwest as the front gets through towards or just before daybreak. By Tuesday morning dew point readings should be in the lower and middle 70s on the other side of the warm front, thus becoming even more humid. && .SHORT TERM /TUESDAY THROUGH WEDNESDAY/... A muggy and mostly cloudy start to Tuesday is expected with the remnants of any early morning shower / t-storm activity lingering. By late morning and midday enough breaks of sun should take place to get temperatures rather warm. Temperatures should get well into the 80s in most places, with the urban corridor of NE NJ getting to lower 90s, and around 90 for portions of NYC. With dew point readings mainly in the lower half of the 70s, heat indices should get into the middle and upper 90s. A few spots will flirt with heat indices around 100, but coverage and confidence is lacking at this time so will hold off on any heat advisory issuance for the urban corridor at this time. A cold front off to the west approaches with showers and storms likely initiating along the pre-frontal trough and back to the west along the cold front itself. NWP appears a bit slower with the progression of the boundary, thus ramp up PoPs and thunder chances later in the afternoon, and into the evening further east across the area. SPC has much of the region in a marginal risk of severe weather, with a slight risk touching far western portions of the CWA. There will be plenty of instability with MLCAPE values getting to around 2000 J/kg via most forecast soundings, at least for the western 1/3rd of the area, with instability slightly less further east. What appears to be marginal are mid level lapse rates and bulk shear values. Trends in these parameters will have to be monitored going forward to evaluate any increase in the severe potential. Guidance is suggestive of a uniform flow for the most part throughout the column out of the southwest. Potential hazards with any storms would be strong to potentially severe winds and heavy rain. The hail threat appears a bit more limited compared to the wind threat. For now have held off on any enhanced wording related to hazards as uncertainty around severe hazards remains high. The cold front gets further east later Tuesday night. Showers and storms are likely through the evening, with chances trailing off getting towards and after 06z. With front appearing a bit slower now, shower chances carry into early Wednesday morning for far eastern sections. A warm and muggy night with minimum temperatures in the upper 60s well northwest, to mostly lower 70s closer to the coast. On Wednesday there remains some question as to how far southeast the frontal boundary ultimately gets. It should press southeast enough to get a drier westerly wind in for the mid to late morning as dew points are progged to get back into the 60s. Still humid, just not quite as muggy. Look for mostly sunny skies into the afternoon hours as clouds could linger for a bit for Eastern LI. Temperatures will be seasonably warm with mostly middle and upper 80s. && .LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/... h5 flow becomes cyclonic Wednesday night through Thursday as a closed low dives SE through Quebec. The associated trough axis and surface cold front shift through the forecast area Thursday afternoon into night, and this will bring the chance of a shower or thunderstorm to the area during this time. Good agreement among the global models and ensembles regarding the h5 pattern for Friday through Sunday. Ridging begins on Friday with an axis shifting east and reaching the Northeast on Sunday, but flattening a little as it does so. Thinking is that this should help prevent showers from popping up as models also agree in the absence of strong shortwaves and sufficient moisture. Have therefore removed the chances of showers that NBM was producing during the day on Sunday. 4th of July is still shaping up to be mostly sunny during the day with comfortable humidity levels, and mostly clear during the evening. NBM looked good for temperatures for the most part. && .AVIATION /18Z MONDAY THROUGH SATURDAY/...
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A stationary front to the south will lift north as a warm front tonight. A cold front will then approach Tuesday afternoon. VFR with SE-S flow mostly less than 10 kt except at KJFK where winds should be slightly higher after 20Z. ENE sound breeze at KLGA about to shift SE-S as well and should do so shortly after 18Z. An isolated tstm still possible near KEWR late today but should not impact the other NYC metro terminals. For tonight, S winds diminish to less than 10 kt throughout. VFR cond to start, then LIFR cigs should move in at KISP/KGON this evening and KBDR after midnight, and may also impact KJFK this evening. Meanwhile showers/tstms likely to move across from the west overnight, mainly 04Z-08Z from the NYC metros north/west, and an hour or two later at the Long Island and CT terminals. Mainly MVFR cond expected at most terminals with this activity (and improvement from LIFR to IFR out east), but can`t rule out brief IFR vsby with any heavier showers/tstms. Some patchy fog with MVFR vsby also possible late after this activity passes. Flight cat improves to VFR throughout by 13Z-14Z, with SW flow around 10 kt. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... * Any isolated showers/tstms near KEWR from about 21Z-01Z unlikely to affect the other metro terminals. * LIFR cigs may be possible at KJFK or nearby over the water from about 01Z-04Z. .OUTLOOK FOR 18Z TUESDAY THROUGH FRIDAY... Late Tuesday afternoon and Tuesday night: Showers/tstms likely into the evening, with MVFR or lower cond. Stronger storms could produce strong winds and brief IFR vsby. MVFR cigs likely at KISP/KGON through the night. Wednesday: VFR. Thursday: Chance of afternoon showers/tstms mainly at KSWF/KHPN with MVFR or lower cond possible, otherwise VFR. Friday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90
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&& .MARINE... Sub advisory conditions will be in place today into tonight with ocean seas mainly at 2-3 ft. As a cold front approaches Tuesday a southerly flow increases and ocean seas will build mostly to 4-6 ft and gusts to around 25 kt resulting in small craft conditions on the ocean, with sub advisory conditions likely remaining on the western non-ocean waters. Some of eastern non- ocean waters will have marginal small craft gusts and may eventually need advisories for Tuesday afternoon and evening. By later Wednesday morning in the wake of the cold front sub advisory conditions should return on the ocean with a W-SW wind and ocean seas mainly around 4 ft. Sub-SCA conditions are expected from Wednesday night through Sunday with a lack of any strong pressure gradients over the region. && .HYDROLOGY... Except for SE CT and eastern Long Island, there is a marginal risk of excessive rainfall on Tuesday. With high PW in place instantaneous rain rates are likely to be high, leading to a localized risk of flash flooding with any stronger thunderstorms, confined mostly to urban and poor drainage locations. && .TIDES/COASTAL FLOODING... There is a low risk of rip current development across the ocean beaches today. There is a high risk of rip currents on Tuesday, especially in the afternoon. && .OKX WATCHES/WARNINGS/ADVISORIES...
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CT...None. NY...None. NJ...None. MARINE...Small Craft Advisory from 11 AM Tuesday to 6 AM EDT Wednesday for ANZ350-353. Small Craft Advisory from 11 AM Tuesday to 2 AM EDT Wednesday for ANZ355.
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&& $$ SYNOPSIS...JC/JE NEAR TERM...JE SHORT TERM...JE LONG TERM...JC AVIATION...BG MARINE...JC/JE HYDROLOGY...JC/JE TIDES/COASTAL FLOODING...