FXUS61 KPHI 161750 AFDPHI Area Forecast Discussion National Weather Service Mount Holly NJ 150 PM EDT Fri Oct 16 2026 .WHAT HAS CHANGED... Updated key message 1, aviation and marine sections. && .KEY MESSAGES... 1. A strong cold front will cross the region late this afternoon and this evening with severe weather possible. 2. Widespread frost and freeze conditions are increasingly likely Saturday night. && .DISCUSSION... KEY MESSAGE 1...A strong cold front will cross the region late this afternoon and this evening with severe weather possible. Low pressure passing north of northern New England will drag a cold front through the region late this afternoon and evening. Clouds over the area are lifting and dissipating somewhat this afternoon, and it will warm up with highs in the upper 70s to low 80s. With clouds breaking up and sunshine developing, gusty southwest winds are ushering a more humid airmass into the area with surface dew points in the mid and upper 60s. While instability values will be relatively low, generally SBCAPE values and MLCAPE values around 500 J/kg, but 06-km Bulk Shear will be upwards of 55-60 kt. SPC has the region in a Slight Risk (level 2 out of 5) for severe weather this afternoon and evening, with part of the region now under a Severe Thunderstorm Watch and the rest of the area likely to be added to an additional watch later on. Timing looks to be around 4pm to 6pm for the southern Poconos, far northwest New Jersey, and the Lehigh Valley, 6pm to 8pm along the I-95 corridor, and from 7pm to 9 pm over Delmarva and southern New Jersey. After sunset, with loss of diurnal heating, the risk for severe weather will start to diminish. A tight pressure gradient then develops over the area tonight through Saturday as broad high pressure centered over the Southern Plains begins to build east. Gusty north to northwest winds will develop tonight and will continue through Saturday, with winds ranging from 15 to 25 mph with 30 to 40 mph gusts. Much cooler on Saturday with highs in the 50s and surface dew points falling towards the 30s. Some showers may linger tonight into Saturday morning especially across southern NJ and Delmarva as the front slows for a time, but they should clear out finally later in the day if not before. KEY MESSAGE 2...Widespread frost and freeze conditions are increasingly likely Saturday night. The primary trough axis looks to pass over the region by Saturday evening, with subtle height falls through Saturday night and into Sunday. Guidance is coming into better agreement that a portion of the trough will close off and linger offshore in the vicinity of the Carolinas, but high pressure will be settling into the region from the northwest. The end result should be mostly clear skies and diminishing winds through Saturday night. With the coldest airmass so far this season settling into the region, the primary question remaining for Saturday night's temperatures is how quickly winds diminish. Current indications are that it could remain a bit breezy through much of the evening, shortening the window of good radiational cooling conditions. Nevertheless, by dawn Sunday winds should be fairly light at least across the Poconos, Lehigh Valley, and adjacent northern NJ. Given this, the current forecast calls for temperatures at or below freezing across these areas. For southeastern PA and central and southern portions of inland NJ, temperatures will likely still fall into the mid 30s. Upper 30s to low 40s are expected across much of Delmarva and coastal NJ. Regarding frost, the airmass that will be infiltrating the area will also be fairly dry, so good radiational cooling will be needed to get widespread frost. Given this, the potential for widespread frost appears limited at thistime to the Poconos and far northern NJ, with patchy frost still possible across the remainder of our eastern PA counties and inland NJ, especially the Pine Barrens. Frost and/or freeze headlines are still very likely to be needed for at least parts of the area Saturday night. Temperatures will begin slowly moderating Sunday into the early part of next week. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Rest of today...CIGs slowly lifting to VFR shortly if not already. A line of SHRA and TSRA will move fairly quickly across the terminals generally from 20Z to 22Z at KRDG/KABE, 22Z to 0Z at KTTN/KPNE/KPHL/KILG, and from 23Z to 01Z at KMIV/KACY. SW winds 10 to 15 kt with gusts up to 20 kt. Moderate confidence. Tonight...SHRA/TSRA taper off by 02Z, then mainly VFR, though showers may linger especially southern terminals. NW winds 10 to 15 kt with 20 to 25 kt. High confidence. Saturday...Mainly VFR, though showers and perhaps some MVFR cigs may linger southern terminals in the morning. NW winds 15 to 25 kt with 25 to 35 kt gusts. High confidence. Outlook... Saturday night through Sunday...VFR. No significant weather. Sunday night through Monday night...Primarily VFR. There is a slight chance for a few rain showers for the near-coast terminals. Tuesday...VFR. No significant weather. && .MARINE... Southwest winds 15 to 20 kt with gusts up to 25 kt this afternoon. A Small Craft Advisory remains in effect for the ocean waters. for later today. A line of showers and thunderstorms capable of damaging wind gusts will move across the waters this evening with the passage of a strong cold front. Winds turn north-northwest tonight and increase to 15 to 20 kt with 25 to 30 kt gusts that will last through Saturday. 30 to 40 kt gusts are likely Saturday. Upgraded Gale Watch to Gale Warning Saturday. Outlook... Saturday night...Advisory conditions likely with gales likely for the outer marine zones. North winds 20-25 kt with gusts 30-35 kt. Seas 4-7 feet. Sunday...Advisory conditions may linger for much of the day with north-northeast winds 15-25 kt and gusts to around 30 kt. Winds should begin to subside later in the day. Seas 4-7 feet, diminishing to 3-5 feet late. Sunday night through Tuesday...There is low confidence due to the potential influence of a possible developing surface low to the south of the region. Advisory conditions may re-develop and could potentially continue at times through Tuesday with elevated north-northeast winds and increasing seas. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...Freeze Watch from late Saturday night through Sunday morning for PAZ054-055-060>062-101-103-105. NJ...Freeze Watch from late Saturday night through Sunday morning for NJZ001-007>009. DE...None. MD...None. MARINE...Small Craft Advisory from 2 AM to 6 AM EDT Saturday for ANZ430- 431. Gale Warning from 6 AM to 6 PM EDT Saturday for ANZ430-431- 450>452. Small Craft Advisory until 6 AM EDT Saturday for ANZ450>455. Gale Warning from 6 AM Saturday to 6 AM EDT Sunday for ANZ453>455. Gale Warning from 6 AM Saturday to 7 AM EDT Sunday for ANZ480>483-485. && $$ DISCUSSION...Cooper/MPS/RCM AVIATION...Cooper/MPS/RCM MARINE...Cooper/MPS/RCM