


Area Forecast Discussion
Issued by NWS Upton, NY
Issued by NWS Upton, NY
Versions:
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
816 FXUS61 KOKX 121806 AFDOKX Area Forecast Discussion National Weather Service New York NY 206 PM EDT Tue Aug 12 2025 .SYNOPSIS... High pressure gradually drifts southeast away from the East Coast into Wednesday as a frontal system approaches from the west. The cold front slowly moves into the area on Wednesday and lingers through Thursday before pushing offshore Thursday night. High pressure returns for Friday and Saturday. Another cold front approaches Sunday, moving through Sunday night, and lingers nearly into early next week. && .NEAR TERM /THROUGH TONIGHT/... Mid-level ridging begins to break down tonight as a frontal system approaches the area from the west. The high pressure system that has been dominating the weather over the last week weakens and pushes further offshore. A persistent S/SW flow tonight will allow for a steady increase in low level moisture with dew points rising into the upper 60s and low 70s, especially for coastal areas. Given the still mostly clear skies and sufficient surface cooling, patchy fog and low stratus are expected to develop late tonight and into Wednesday morning. Lows tonight will be in the upper 60s and low 70s. && .SHORT TERM /WEDNESDAY THROUGH THURSDAY/... By Wednesday, a hot and humid airmass is anticipated to be in place with surface temperatures expected to climb into the upper 80s to low 90s for much of the area. Dew points in the upper 60s and low 70s may make some locations feel like temperatures will be in the middle to upper 90s. This heat should only last a single day, and thus have opted not to issue any sort of heat advisory headline. As the surface heats up and with ample surface moisture present, the approaching prefrontal trough during the afternoon may end up sparking some convection west of the area. CAPE values will be on the order of 750-1500 J/kg, but with forcing primarily to the north and little in the way of shear (15-20kt), convection isn`t expected to be long-lasting or severe. Despite the lack of shear, some stronger storms can`t be ruled out with some isolated severe gusts possible. SPC has the area only in a general risk of thunderstorms. Heavy rainfall will also be possible with these storms as PWATs will be near 1.5-2". While flash flooding is not anticipated as it`s been dry the last few weeks and storms should be moving at a decent pace, isolated and localized hydrologic concerns can`t be ruled out either, especially if any training storms set up. WPC has the western portion of the area in a marginal risk for excessive rainfall, mainly the Lower Hudson Valley and interior NE NJ. Any thunderstorms are expected to weaken and shift east during the evening. The cold front will gradually approach from the west overnight and into the day on Thursday. Additional showers or an isolated storm is possible overnight Wednesday night into Thursday morning. Fog is once again possible, especially in any areas that see rain earlier in the day. The front will slowly make its way through the area on Thursday with temperatures cooling a few degrees as compared to Wednesday. Additional pop-up showers and thunderstorms are anticipated by Thursday afternoon, especially if any cloud cover is able to thin out from previous convection into Thursday morning. The front pushes through by Thursday evening with drying conditions expected thereafter. && .LONG TERM /THURSDAY NIGHT THROUGH TUESDAY/... The long term period will be mainly quiet with a couple of cold fronts moving through the region. Temperatures will be near seasonal normals much of the time, with the exception of Sunday into Monday when temperatures will be several degrees above normal. The NBM was followed for the extended period. A cold front will be moving to the south and east of the region Thursday evening as high pressure builds in from the north. This high settles overhead for Saturday, and then moves off the northeast coast, bringing at return flow with warmer and more humid conditions for Sunday, and heat indices potentially reach the mid 90s across much of the region. Another cold front passes through the area Sunday night bringing a chance of showers and thunderstorms. Currently this front is expected to linger nearby as a larger upper trough remains over eastern Canada and extends into the northeastern states, keeping ridging to the west, along with surface high pressure. A wave of low pressure moves along the front for the beginning of next week, with chances of precipitation late Monday through Tuesday.. && .AVIATION /18Z TUESDAY THROUGH SUNDAY/... Offshore high pressure will gradually give way to a cold front approaching from the Great Lakes. Expect a mainly VFR forecast with the exception of the eastern terminals. KGON will likely see a period of MVFR/IFR conditions as low clouds and fog rolls in off the water later tonight. Confidence is lower at KBDR and KISP with only a TEMPO for MVFR fog late tonight. A prefrontal trough will then bring a chance of scattered showers and thunderstorms to the terminals Wednesday afternoon and night. Southerly winds this afternoon around or just over 10 kt will become SW this evening and decrease overnight. Winds will then ramp back up to around 10 kt on Wednesday, backing more to the S by afternoon. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... Low chance for MVFR ceilings/visibilities early Wednesday morning. .OUTLOOK FOR 18Z WEDNESDAY THROUGH SUNDAY... Wednesday Afternoon: Chance of late day/evening showers/thunderstorms with MVFR or lower. Chance of showers late at night. Thursday: Mainly VFR. Chance of showers and thunderstorms. Thursday night-Sunday: VFR. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... With a weak pressure gradient in place, winds and seas are expected to remain below Small Craft Advisory (SCA) criteria through the week. && .HYDROLOGY... Thunderstorms ahead of an approaching cold front Wednesday afternoon and evening could produce locally heavy downpours that result in minor nuisance flooding, especially areas west of the Hudson River. The overall flood threat is low however. There are no significant hydrological concerns Thursday through the week. && .TIDES/COASTAL FLOODING... A moderate rip current risk remains in place today and Wednesday along ocean beaches due to persistent E-ESE swells with 2 to 3 ft waves and an 8 to 9 second period. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...Air Quality Alert until 11 PM EDT this evening for CTZ005>012. NY...Air Quality Alert until 11 PM EDT this evening for NYZ067>075- 078>081-176>179. NJ...Air Quality Alert until 11 PM EDT this evening for NJZ002-004- 006-103>108. MARINE...None. && $$ SYNOPSIS...MET/MW NEAR TERM...MW SHORT TERM...MW LONG TERM...MET AVIATION...DW MARINE...MET/MW HYDROLOGY...MET/MW TIDES/COASTAL FLOODING...