650 FXUS61 KPHI 051042 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 642 AM EDT Thu Jun 5 2025 .SYNOPSIS... A cold front will approach the area later today and Friday, before tracking across the Mid-Atlantic region on Saturday. High pressure will briefly build in Sunday and Monday. A warm front will move through the region on Tuesday. Another cold front will then track through the forecast area on Wednesday. && .NEAR TERM /THROUGH TONIGHT/... Uneventful weather during the near term with high pressure well offshore and subsidence within the local region. The nearest disturbance is a cold front back across the upper Great Lakes, however a weak coastal system is also taking shape along the Carolina coast. The front will creep slowly east through the day today, and the coastal system will slowly move north along the coast through today as well. Unlike the past couple days though, high cloud cover from the approaching systems will blanket the region, especially by this afternoon. Highs today will be well above normal with mid/upper 80s across most spots. Some stations within the area, especially from the Philly metro and north/west, could experience their first 90 degree day of the year. The increasing high clouds will be a limiting factor on this though, which should be thickest toward the south across the coastal plain. Thus, places in northern NJ and eastern PA could end up a few degrees warmer than the typical warmer areas of the Philly metro, southern NJ, and Delmarva. Cooler at the shore with temperatures mainly in the 70s expected. The humidity will be more noticeable today with dewpoints rising into the mid to upper 60s, though some mixing out may occur later in the day. Dry conditions are expected across most of the area through tonight. A couple of minor exceptions though, a slight chance (15-20%) of a terrain driven shower or thunderstorm across the Southern Poconos very late this afternoon and into tonight as the cold front from the west approaches. The other exception will be down in Delmarva, as the coastal low approaches, it will potentially fire a few showers across southern Delaware late in the overnight hours tonight. && .SHORT TERM /FRIDAY THROUGH SATURDAY NIGHT/... The cold front will inch closer on Friday. Its progress still looks to be slow with little upper-level support and the continued presence of the coastal surface low just south of the region. Most forecast models have the coastal low moving out to sea Friday night in the waking of the departing high. With the cold front coming in from the west and being a bit closer, we`re expecting more showers to track into the forecast area, possibly down to the 95 on Friday afternoon and night. PWAT values will start creeping up across the region too, topping out between 1.25-1.75 inches. As a result, there will be potential for a heavy shower or downpour. Our zones north and west are highlighted in the ERO (Marginal) as a result. Across the Delmarva and maybe even Cape May county, we can`t rule out a stray shower as the southern coastal low makes it`s way offshore. By Saturday, with an upper level trough beginning to deepen to our west and the coastal low moving further offshore, the cold front will finally have the support to begin to move across the area, and lead to increasing chances of precipitation. There is some instability forecast with CAPE values of 500-1000 J/kg, and PW values increase to 1.5-2.0 inches. So there will be the potential for thunderstorms and brief heavy downpours. Mid-level winds are forecast to be fairly weak, 40-50 knots or less, so shear is not expected to be overly strong. However, there could be a few isolated strong storms. High temperatures on Friday will mainly top out in the mid 70s to mid 80s. With it being unsettled on Saturday as the cold front moves through, highs will run in the upper 60s to upper 70s. Delmarva could still see lower 80s. Lows will be in the upper 50s to mid 60s both nights. && .LONG TERM /SUNDAY THROUGH WEDNESDAY/... The long term forecast period continues to look active. This is in part due to a quasi-zonal pattern aloft with a series of weak upper-level waves moving through the larger scale west-east flow laying across region. A deepening upper level trough then does look to approach the region by mid-week potentially signaling an end to this pattern. Overall though, the forecast for the new week is relatively uncertain. At the surface, latest model guidance indicates that high pressure may only briefly build in on Sunday before a weak wave lifts the stalled front to our south back north towards our region. As a result, PoPs for Sunday have increased, with a chance (30-40%) for showers or a thunderstorm across much of the region. As this wave departs, high pressure looks to build back in late Sunday into early Monday, before another wave comes along bring another chance for rain later Monday. By Tuesday, with the deepening trough beginning to move towards the region, the surface front will be able to push northward through the region as a warm front, ahead of a cold front on Wednesday as the upper-level trough swings through the region. Showers and a few thunderstorms look likely on Tuesday and into Wednesday before PoPs decrease later on Wednesday as the cold front departs. Temperatures throughout the long term period look to be within a few degrees of normal for early June. Highs will be in the 70s to lower 80s and lows will mainly be in the upper 50s and 60s. && .AVIATION /12Z THURSDAY THROUGH MONDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Today...VFR expected. BKN to OVC cirrus by afternoon. Light winds becoming south to southwest around 10 knots by 18Z. High confidence. Tonight...VFR but BKN to OVC ceilings will be lowering as mid- level clouds move in. South-southwest winds initially around 5-10 knots, decreasing to 5 knots or less. High confidence. Outlook... Friday...Mainly VFR conditions expected but sub-VFR conditions possible with a chance (30-40%) for showers or a thunderstorm. Saturday...Sub-VFR conditions expected at times with showers and thunderstorms likely (60-70%). Sunday and Monday...Mainly VFR conditions expected but sub-VFR conditions possible with chances (25-35%) for showers or a thunderstorm. && .MARINE... No marine headlines expected through tonight. South-southwest winds around 10 knots expected with a few gusts up to around 20 knots possible, particularly this afternoon. Seas of 2-3 feet. Fair weather. Outlook... Friday...Sub-SCA conditions expected. However, winds will gust to around 15-20 knots at times and seas will increase to 3-4 feet. Friday night and Saturday...Small Craft Advisory conditions possible. Shower and storms will be possible Saturday, which may lead to locally higher winds and waves. Seas build to 3-5 feet. Sunday and Monday...Sub-SCA conditions expected. Rip Currents... There is a LOW risk for the development of dangerous and life threatening rip currents for the Jersey Shore and Delaware Beaches for both today and Friday. Today, south to southwest winds will average 10 to 15 mph with breaking waves of 1 to 2 feet with a period of 7-8 seconds. For Friday, similar conditions can be expected with south to southeast winds 5 to 10 mph with breaking waves around 1-2 feet. For specific beach forecasts, visit weather.gov/beach/phi && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ SYNOPSIS...AKL NEAR TERM...AKL SHORT TERM...AKL LONG TERM...AKL AVIATION...AKL MARINE...AKL/MPS