Area Forecast Discussion
Issued by NWS Upton, NY
Issued by NWS Upton, NY
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679 FXUS61 KOKX 132334 AFDOKX Area Forecast Discussion National Weather Service New York NY 734 PM EDT Tue Aug 13 2024 .SYNOPSIS... Surface high pressure remains in place through the middle of the week with subtle disturbances passing by. A weak surface trough moves through the region Thursday, otherwise high pressure dominates, moving offshore Friday night. A frontal system will slowly approach from the west Friday night through Sunday. The system`s cold front moves through Monday into Monday night. A trough remains Tuesday. && .NEAR TERM /UNTIL 6 AM WEDNESDAY MORNING/... Updated for current conditions. The area remains under an upper level trough with weak disturbances rotating through the middle of the week. At the surface, high pressure largely remains in control with mostly dry conditions with seasonable temperatures. Any cloud cover should clear out as the BL decouples tonight. Clear skies and relatively light to calm winds should allow for radiational cooling to be fairly efficient, especially for the outlying and interior areas. Low temperatures will be in the low to middle 60s. Interior and outlying areas may cool into the upper 50s. Additionally, patchy fog may develop in the coolest areas, mainly after midnight and into the morning. && .SHORT TERM /6 AM WEDNESDAY MORNING THROUGH WEDNESDAY NIGHT/... Any patchy fog in the morning quickly burns off with sunrise. Mostly clear skies are expected in the morning. High temperatures are expected to be a bit warmer than recent days with temperatures rising into the middle to upper 80s. A weak disturbance moving overhead in the upper trough along with the warmer surface temperatures may allow for the development of isolated to scattered showers for the Lower Hudson Valley and Southern Connecticut into the afternoon. There may be enough instability for there to be an isolated thunderstorm as well. While these showers and isolated storms may develop and move south toward the coast, they`re not expected to maintain themselves for very long with little to no shear. As a result, kept slight chance PoPs confined to the Lower Hudson Valley and Connecticut. Not completely out of the question that a shower or isolated storm impact areas toward the NYC metro or coast however. Mostly clear skies once again expected Wednesday night with another decent chance at radiational cooling, for outlying and interior areas. Lows are expected to be in the middle to upper 60s, with cooler spots in the low 60s to possibly upper 50s. Patchy fog may once again develop for cooler spots. && .LONG TERM /THURSDAY THROUGH TUESDAY/... An upper and mid level trough remains over the northeast and into the Mid Atlantic Thursday as a surface high and upper ridge remain nearly blocked by this trough. The upper trough and surface high moves slowly eastward Friday into the weekend. A weak shortwave rotates into the eastern upper trough Thursday, with a weak surface trough across the areas. This trough and upper energy may be strong enough, with some instability and CAPE during the afternoon, for a few showers and thunderstorms to develop. This trough then slowly tracks eastward into the western Atlantic Friday and Friday night as a frontal system slowly approaches from the west. The upper pattern remains nearly blocked, and the frontal system with its slow progression may affect the area into the beginning of next week. The movement of this system may also be impacted by Tropical Storm Ernesto`s track late in the week and into the upcoming weekend. Please refer to the National Hurricane Center for forecasts on Tropical Storm Ernesto. Temperatures will be near seasonal normals Thursday through Tuesday. Humidity levels will be increasing Friday night into Sunday, as dew points rise from the lower and mid 60s to the upper 60s to around 70. Uncomfortable humidity levels will then continue into the beginning of next week. && .AVIATION /00Z WEDNESDAY THROUGH SUNDAY/... Weak high pressure will generally remain in control through the TAF period, with a surface trough moving through on Wednesday. VFR. Winds become light and variable tonight or around 5 knots out of the northwest. A late day sea breeze may keep KJFK at a southerly flow until about 01z or 02z before flipping back round to the northwest. Potential for the sea breeze to briefly make it to KISP. Northwest flow stays light on Wednesday with potential for sea breezes again. Isolated showers/thunderstorms are possible Wednesday afternoon, but given low confidence in coverage and occurrence have left out of the TAF for now. ...NY Metro (KEWR/KLGA/KJFK/KTEB) TAF Uncertainty... The late day sea breeze could keep KJFK at a southerly flow until about 01 or 02z. Low confidence in it making it through any other NYC terminals. OUTLOOK FOR 00Z THURSDAY THROUGH SUNDAY... Wednesday Night: VFR. Thursday: Mainly VFR. Slight chance of showers which could bring brief MVFR conditions. Friday: VFR. Saturday through Sunday: Chance of showers/thunderstorms with MVFR conditions possible. Detailed information, including hourly TAF wind component forecasts, can be found at: https:/www.weather.gov/zny/n90 && .MARINE... No changes to winds and seas at this time. High pressure provides a weak pressure gradient and a light wind regime overall through Friday with sub-SCA levels. The combination of an approaching frontal system Friday night into the weekend along with building long period southeast swells from Tropical Storm Ernesto will allow for ocean seas to build rapidly to SCA levels, going from 2 ft late Friday afternoon to 5-6 ft by daybreak Saturday. Please refer to the NHC for official forecasts of Tropical Storm Ernesto. && .HYDROLOGY... There are no hydrologic concerns through the end of the week. It is too early to know what, if any, impacts may arise from an approaching frontal system this weekend. && .TIDES/COASTAL FLOODING... There is a low rip current risk at the ocean beaches through Wednesday. A moderate rip current risk is forecast for all the beaches Thursday, especially late in the day, as long period southeast swells build. && .OKX WATCHES/WARNINGS/ADVISORIES... CT...None. NY...None. NJ...None. MARINE...None. && $$ SYNOPSIS...MET/MW NEAR TERM...MET/MW SHORT TERM...MW LONG TERM...MET AVIATION...JT MARINE...MET/MW HYDROLOGY...MET/MW TIDES/COASTAL FLOODING...