196 FXUS61 KPHI 112347 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 747 PM EDT Wed Jun 11 2025 .SYNOPSIS... Broad high pressure over the Mid-Atlantic slides offshore by Friday. A weak cold front approaches from the west Thursday night and becomes nearly stationary over the Mid-Atlatic into the weekend. Several waves of low pressure will affect the area starting late Friday and continuing into the new week. && .NEAR TERM /THROUGH THURSDAY NIGHT/... High pressure located across the Ohio River Valley will break down through tonight, but fair weather will remain with zonal flow aloft. On Thursday, the high will continue to break down, before a cold front approaches from the northwest late in the afternoon into the evening. Fair weather will continue for much of the day, however, by late in the afternoon and into the evening, as the cold front moves into the area, there will be a chance of showers and isolated thunderstorms for portions of northeast Pennsylvania and northern New Jersey. As 700-500 mb winds increase to 40-50 knots, any thunderstorms that do develop could end up producing locally gusty winds; and with PW values approaching 1.25-1.50 inches, some locally heavy gullywashers will be possible. && .SHORT TERM /FRIDAY THROUGH SATURDAY/... High pressure just northeast of the region Friday morning moves offshore Friday afternoon. A stationary front will be draped over the Mid-Atlantic area, and low pressure slowly approaches from the west late Friday on that boundary. The low passes through Delmarva and southern New Jersey Saturday morning through Saturday afternoon before departing. A few showers and perhaps a thunderstorm may develop late Friday afternoon as some shortwave energy approaches from the west but the bulk of the activity hold off until Friday night through Saturday morning with the passage of the low. Highest instability will be focused on Delmarva, generally in the vicinity of the low, but not expecting severe weather. Will carry slight chance to chance for thunderstorms, mainly Friday night. After the low departs late Saturday morning, the stationary front over the Mid-Atlantic lifts north as a warm front as low pressure moves into the Great Lakes. Some shortwave energy ahead of that low moves into the northern half of the forecast area. With surface dew points rising through the 60s and approaching 70, another round of showers and thunderstorms is possible late in the day. PoPs will mostly be chance, but PoPs will be likely for portions of the southern Poconos and western Lehigh Valley. The threat for severe weather is minimal, but with increasing dew points and PWATs over 1.5 inches for most of the area, and over 2 inches for Delmarva, locally heavy rain is a threat. && .LONG TERM /SATURDAY NIGHT THROUGH WEDNESDAY/... Low pressure approaches from the west and slowly works its way through the Mid-Atlantic and Delmarva Sunday through Monday. A prolonged period of unsettled weather is on tap during this time with showers and isolated to scattered thunderstorms. Given abundant low level moisture with surface dew points well in the 60s, locally heavy rain will develop from time to time. WPC has a Marginal Risk (1 out of 4) for excessive rain Saturday night through Sunday and again Sunday through Sunday night. Rain tapers off on Monday as low pressure departs. With a prolonged period of onshore flow, temperatures will be on the cool side through the weekend and into Monday with highs on Sunday in the low to mid 70s and highs on Monday in the upper 60s to low 70s. Several additional shortwaves approach from the west as the week progresses, and weak waves of low pressure will develop as a result. This will keep low chance PoPs in the forecast through Wednesday. Temperatures will rebound somewhat on Tuesday before warming back into the 80s on Wednesday. && .AVIATION /00Z THURSDAY THROUGH MONDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Tonight...VFR. Southwest winds 5 knots or less, becoming light and variable overnight. Thursday-Thursday night...VFR. Slight chance of showers or thunderstorms in northeast Pennsylvania and northern New Jersey. West winds 5-10 knots during the day, then light and variable overnight. Occasional gusts 15-20 knots possible. Outlook... Friday...VFR initially, then scattered afternoon SHRA develop with brief sub-VFR conds possible, mainly west of the I-95 terminals. Friday night through Saturday...Sub-VFR in SHRA and scattered TSRA. A break in SHRA possible around midday Saturday before ramping up again Saturday afternoon. Saturday night through Monday...Sub-VFR likely in RA and scattered TSRA. && .MARINE... Tonight-Thursday night...Conditions remain below advisory levels. Outlook... Friday through Monday...Overall, sub-SCA conditions expected, though there is the potential for SCA conditions Sunday night through Monday. VSBY restrictions in rain and isolated to scattered thunderstorms throughout this period. Rip Currents... For Thursday, southwest winds around 5-10 mph turning south in the afternoon behind a sea breeze. Breaking wave heights of 1-3 feet with a weak southeasterly swell of 1 foot around 9 seconds. We will be a few days removed from the Full Moon from Tuesday night, therefore expecting to see less of an impact to tides as a result. We have a LOW risk for dangerous rip currents at all beaches. For Friday, east-northeast winds around 5-10 mph turn more easterly in the afternoon. Breaking wave heights remain around 1-3 feet with a weak southeasterly swell of 1 foot around 9 seconds. No major differences from Thursday, so we will maintain a LOW risk for dangerous rip currents at all beaches. For specific beach forecasts, visit weather.gov/beach/phi && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ SYNOPSIS...MPS NEAR TERM...Robertson SHORT TERM...MPS LONG TERM...MPS AVIATION...MPS/RCM/Robertson MARINE...MPS/Robertson