995 FXUS61 KPHI 271424 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 1024 AM EDT Sat Apr 27 2024 .SYNOPSIS... A warm front will approach this afternoon, bringing above normal temperatures for the rest of the weekend and into early next week. High pressure will remain in control behind the front with low chances of showers and storms. A weak system will bring a more widespread chance of storms on Tuesday, although temperatures will remain above normal through much of next week. && .NEAR TERM /THROUGH TONIGHT/... Clouds are quickly increasing and thickening from west to east this morning as a warm front approaches from the west and moves eastward through the region late this afternoon and into the evening. There will be some showers associated with this front as it arrives across eastern PA, but very dry low levels will help prevent much of it reaching the ground. Still cannot rule out some isolated to scattered light showers mid to late afternoon, particularly across eastern PA and northern NJ, but brief isolated showers or sprinkles will be possible just about anywhere across our region from mid afternoon into early evening. The cloud cover will keep temperatures a bit cool with highs in the upper 50s to low 60s. With the warm front passage and cloud coverage overhead, expecting a more seasonable night ahead tonight temperature-wise with lows in the mid to upper 40s (low 40s Poconos). The warm advection aloft should result in some additional isolated to scattered showers overnight, mainly near and north/east of Philly. && .SHORT TERM /SUNDAY THROUGH MONDAY NIGHT/... The story of the short term forecast will mainly be warm temperatures. An upper-level ridge axis over the eastern CONUS Sunday will slowly drift eastwards with time. Though this ridge axis may diminish in strength some later Monday into Monday night, high anomalous geopotential heights will prevail over the region through the end of the term. Meanwhile, at the surface level, high pressure systems will look to be centered off the coast of the Mid-Atlantic region and north of the Great Lakes region Sunday. With time, the high pressure off the Mid-Atlantic will look to slide southwards as the high pressure system well to our northwest slides eastwards. Given the synoptic pattern and evolution described, the region will see strong warm air advection (WAA) during the short term leading to very warm temperatures. Highs mainly in the upper 70s to low 80s are in the forecast for Sunday. With even stronger WAA Sunday night and Monday many locations will see high temperatures in the mid to upper 80s Monday. Mesoscale wise, with synoptic winds forecast to only be 5-10 mph Monday, a strong sea breeze will probably develop. Coastal areas could see high temperatures approximately 10 degrees colder than most inland locations both Sunday and Monday. It will be interesting to see how far inland the sea breeze ends up penetrating Monday evening. Otherwise, some shortwave energy could propagate through Sunday/Sunday night and Monday/Monday night. A few scattered showers and thunderstorms are possible for our northern and northwestern most areas Sunday afternoon/Sunday night and Monday afternoon/Monday night. && .LONG TERM /TUESDAY THROUGH FRIDAY/... Fairly unsettled but not too overly impactful long term looks to be on the horizon. The upper-level ridge axis over the northeastern CONUS Tuesday looks to break down with time. Though the ensembles suggest another weaker ridge axis could build to our west while moving eastwards with time Tuesday night into Thursday, the overall upper-level pattern looks to become more zonal like and somewhat slow moving Tuesday night onwards. Weak trough looks to approach Tuesday and move through the region Tuesday/Tuesday night. Otherwise, multiple rounds of shortwave energy and perhaps some weak surface boundaries hanging around or moving through could be in the cards. Stuck with NBM PoPS for this forecast. Slight chance or chance of showers each day. Greatest chance for showers and thunderstorms is later Tuesday/Tuesday night time frame and Friday/Friday night time frame. Upper-level trough will look to come through Tuesday/Tuesday night with cold front at the surface. Another cold front passing through is possible Friday into Friday night. Well above average temperatures expected to continue into Tuesday. Above average temperatures likely Wednesday through the end of the term. && .AVIATION /14Z SATURDAY THROUGH WEDNESDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas... Today and tonight...VFR to start with increasing clouds. MVFR cigs possible for ABE/RDG/TTN late afternoon and night with broken cigs around 5-7kft elsewhere. A few widely scattered showers will arrive from west to east between 18-22Z, and may briefly bring sub- VFR visibilities as well, but that should be the exception. Southeast to south winds around 10 knots, easing to 5 kt or less tonight. Moderate confidence. Outlook... Sunday through Wednesday...Mainly VFR. Scattered showers/tstms possible each afternoon and evening, especially Tuesday. && .MARINE... A few stronger wind gusts could develop across the upper Delaware Bay/lower Delaware River with SSE winds funneling and gusting to around 20 kts. Otherwise, conditions will remain below Small Craft Advisory levels through tonight with east to southeast winds generally around 10 knots and seas 2 to 4 feet. Outlook... Sunday through Wednesday...No marine headlines anticipated. Scattered showers/tstms possible Tuesday afternoon/Tuesday night. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...None. && $$ SYNOPSIS...MJL NEAR TERM...Dodd/MJL SHORT TERM...Wunderlin LONG TERM...Wunderlin AVIATION...Dodd/MJL/Wunderlin MARINE...Dodd/MJL/Wunderlin