Strong thunderstorms rolled in early in the morning of April 4, with storms producing damaging wind gusts across portions of southeastern Pennsylvania. Storms also produced large hail.
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Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS PHI wrote it up.
Strong thunderstorms rolled in early in the morning of April 4, with storms producing damaging wind gusts across portions of southeastern Pennsylvania. Storms also produced large hail.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Philadelphia/Mount Holly wrote its last area forecast discussion before the first event at Apr 4, 2:08 AM EST, 1 hour 52 minutes earlier.
Area Forecast Discussion National Weather Service Mount Holly NJ 308 AM EDT Fri Apr 4 2025 .SYNOPSIS... A cold front settles to our south today and tonight as high pressure builds across portions of southeastern Canada and New England. As low pressure moves up the Ohio Valley and then across the Great Lakes tonight and Saturday, the front will move northward some as a warm front. A cold front then moves through Sunday followed by a stronger cold front Monday night into early Tuesday. High pressure then builds in later Wednesday before shifting offshore into Thursday. && .NEAR TERM /THROUGH TONIGHT/... Cold front continues progress through the region. The front is rather diffuse with the strongest cold and dry air advection lagging well behind the front. Showers remain a possibility into mid morning with some lift as the front continues to progress through the region. We saw mostly stable conditions earlier, but trends over the last hour have shown elevated instability in some high res models generally near and south of Reading and Philly. Additionally, isolated thunderstorms were observed in central PA as of 3 AM. Therefore, included a mention of thunder for these areas through mid morning. Still expect the primary mode to be showers. We should have a lull in any rain through much of the day. The front will stall just south of our region. However, with the cold air advection lagging well behind the front, most areas will still be warmer than normal with highs ranging from the upper 50s to near 70. As the next low pressure system lifts through the Ohio Valley overnight, the stalled front will begin to slowly work its way back north as a warm front. This will lead to another chance for rain overnight. Predominant mode is expected to be showers, but if the front starts lifting north early enough, a few rumbles of thunder are possible in Delmarva during the evening hours. As with the previous low pressure system, the main forcing with this system will stay well north of our region. Therefore, rain amounts overnight are expected be light, generally less than a quarter of an inch of rain. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... As high pressure slides to our north Saturday, low pressure tracks up the Ohio Valley and then moves mostly to our north through Saturday. This will start to pull the stalled boundary just south of Delmarva back north as a warm front. Some additional showers develop Saturday, although the focus should become more focused farther northward with time. Onshore flow Saturday however will keep the area rather cloudy and much cooler with even some morning drizzle possible. The location of the front and associated warm sector to its south will impact how warm the area gets. As of now, it should get the warmest during the day Saturday across much of our Delmarva zones with temperatures then quickly turning cooler northward. Again, these temperatures will be highly dependent on how far north the warm front gets however with high pressure sliding by to our north and an onshore flow the warm front should be slow to move northward. Some fog may begin to develop Saturday night mainly along the coast and the adjacent marine area as dew points start to increase and rise above the chilly ocean water temperatures. As we go through Sunday, a significant upper-level trough slides across central to eastern Canada and it is forecast to amplify southward with its leading edge starting to move into the Northeast Sunday night. This trough will drive low pressure well to our north, however a trailing cold front will arrive in our area Sunday. The existing warm front across the area looks to surge northward Sunday morning however the cold front looks to be not to far behind. How far north and inland the warm sector gets ahead of the cold front will determine how warm areas get. The dew points will rise through the 50s in areas that get more into the warm sector for a time. The warm and more moist air mass may also result in marine fog that could impact the coastal areas as well, before it gets pushed out as the low-level flow veers from the southwest to west. While the parent trough lags well behind the surface cold front, height falls arriving with a greater thickness packing also arriving from the west should result in enough forcing for ascent for showers to develop and move in from the west especially in the afternoon and at night. The timing consensus of the cold front looks a bit faster and this resulted in temperatures a bit lower especially north of Delmarva. Some thunder is certainly possible given the strength of the incoming trough, however the intensity of any convection will depend on the available instability and shear magnitudes in combination of any stronger forcing for ascent. && .LONG TERM /MONDAY THROUGH THURSDAY/... Summary...A stronger cold front moves through Monday night followed by high pressure arriving Wednesday into Thursday. High temperatures falling to several degrees below average through the middle of next week, then some warming begins on Thursday. Synoptic Overview...An upper-level trough is forecast to amplify into and across the East during early next week, before starting to lift out on Wednesday. The next upper-level trough then looks to begin to amplify across the eastern U.S Wednesday night and Thursday. At the surface, a stronger cold front moves through Monday night. High pressure then builds in during Wednesday before shifting offshore into Thursday. A warm front well ahead of low pressure may then arrive later Thursday. For Monday and Tuesday...This time frame starts as more of a day in transition on Monday as the first cold front is offshore and we await a secondary cold front tied to the amplifying upper-level trough. This second front may end up moving through our area Monday night with little in the way of precipitation as the deeper moisture is shoved offshore with the earlier cold front. Given the strength of the incoming upper-level trough however, cannot ruled out a few rain showers with the second cold front mainly Monday night or early Tuesday. The arrival of the colder air aloft along with cyclonic flow may result in a few rain/snow showers across portions of far northwestern zones. High temperatures Monday should be several degrees below average. The second cold front should be offshore to start Tuesday with strong cold air advection underway. There will be a tightened pressure gradient in place between departing low pressure well to our northeast and incoming high pressure from the Midwest to the Ohio Valley. This will translate to a gusty wind on Tuesday with peak gusts in the 25-35 mph range before diminishing some at night. High temperatures Tuesday look to be well below average as much of the area may not get above the 40s during the day. It will be cold Tuesday night with most if not all areas dropping below freezing. There may be to much wind for frost formation, however a freeze warning may be needed where the growing season has started (most of our Delmarva zones). For Wednesday...The strong upper-level trough is currently forecast to be lifting out with time. This will result in surface high pressure building into our area before it starts to shift offshore at night. There may still be a gusty wind in place before a tightened pressure gradient relaxes as the center of the surface high builds closer. High temperatures will be several degrees below average once again, and the wind will determine how cold it gets at night despite the air mass especially aloft starting to modify. A clear sky with dew points below freezing would typically yield a cold night especially if the wind is able to completely decouple. As a result, there is some risk for frost and/or freeze (the growing season has started for most of our Delmarva zones). For Thursday...The next upper-level trough looks to begin amplifying into the Eastern U.S. A surface low is forecast to be tracking toward the upper Ohio Valley with a warm front approaching our area from the southwest. This will be dependent on the strength of the developing low relative to the departing high, so much of Thursday may end up remaining dry. Temperatures do look to begin to moderate though as southerly flow returns in advance of this system. && .AVIATION /07Z FRIDAY THROUGH TUESDAY/... The following discussion is for KPHL, KPNE, KTTN, KABE, KRDG, KILG, KMIV, KACY and surrounding areas. Through Today...Showers, with tempo reductions to MVFR are possible through 15Z. There have been some localized and brief IFR conditions further upstream, but given the latest trends, it appears unlikely (20% or less) that any of our TAF sites will get that low. Winds generally favoring SW less than 10 kt will shift to northwest around 10kt after 09Z. High confidence on the overall pattern, but low confidence on the timing of any flight category changes. Tonight...Mostly VFR, though some brief MVFR will be possible as showers move into the region from the south. Initially with sunset, expect winds to go light and variable, but eventually will settle out of the east near or below 10 kt. Moderate confidence. Outlook... Saturday...Sub-VFR conditions probable along with some showers. Some drizzle possible in the morning. Sunday...Sub-VFR conditions due to low clouds and/or fog should improve some during the day from south to north. Showers and possibly a thunderstorm especially in the afternoon and at night will result in visibility restrictions. Southwest to west and northwest winds could gust up to 25 knots during the day. Monday...Sub-VFR conditions possible lingering showers ending. Tuesday...VFR. Northwest wind gusts up to 30 knots. && .MARINE... A Small Craft Advisory remains in effect for the Atlantic Coastal Waters through later this morning. In the last 2 hours, seas have increased above 5 ft once again, so will keep the SCA going for now, but will be watching trends to see if seas decrease earlier than the current expiration time. Once seas subside, winds and seas should stay below SCA criteria for the remainder of today and Friday Night. Outlook... Saturday...The conditions should be mostly below Small Craft Advisory criteria. Some visibility restrictions possible due to some fog mostly at night. Sunday...Small Craft Advisory conditions possible. Visibility restrictions possible due to some morning fog, then showers and possibly a few thunderstorms mainly in the afternoon and at night. Monday...Small Craft Advisory conditions possible especially in the morning. Tuesday...Small Craft Advisory conditions probable. && .PHI WATCHES/WARNINGS/ADVISORIES... PA...None. NJ...None. DE...None. MD...None. MARINE...Small Craft Advisory until noon EDT today for ANZ450>455. && SYNOPSIS...AKL/Gorse NEAR TERM...Johnson SHORT TERM...AKL/Gorse LONG TERM...AKL/Gorse AVIATION...Gorse/Johnson MARINE...Gorse/Johnson
The Philadelphia radar (KDIX), 62 km away, was scanning. The volume nearest the first event began at 09:01 UTC.
11 thunderstorm wind, 5 hail. Local standard time, as filed.
There was a partial structural collapse from a tree falling into a building.
Multiple trees and wires were blown down.
Several trees were blown down and some trunks snapped.
Multiple trees were blown down which also resulted in damage to a fence and a window.
A tree was blown down on to a vehicle.
Several trees were uprooted, some trunks snapped, and fences blown down near Timber Creek Park.
Multiple trees were blown down in the Broadmoor Neighborhood.
Multiple trees and wires were blown down.
Multiple trees were blown down.
Multiple trees and wires were blown down.
Tree damage was reported and a center pivot irrigation system was blown over.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in New Jersey in 2025Every state in 2025This day in weather historyWarnings in New Jersey, April 2025
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 1255535, 1255537, 1255528, 1255540, 1255545, 1255546, 1255548, 1255529, 1255530, 1255549, 1255550, 1255551, 1255552, 1255531, 1255554, 1255532.