A squall line developed in western Ohio on April 17th along a cold front before tracking east into western Pennsylvania. Behind the cold front, a 50kt low-level jet was measured on the KPBZ radar at 3,000ft and surface based instability ranged between 500J/kg to 1,000J/kg.
Every event with a place to put it. Tap one for its entry below.
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 PBZ wrote it up.
A squall line developed in western Ohio on April 17th along a cold front before tracking east into western Pennsylvania. Behind the cold front, a 50kt low-level jet was measured on the KPBZ radar at 3,000ft and surface based instability ranged between 500J/kg to 1,000J/kg. As a result, widespread wind damage was noted with this passing system.
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 Pittsburgh, PA wrote its last area forecast discussion before the first event at Apr 17, 6:02 PM EST, 3 minutes earlier.
Area Forecast Discussion...UPDATED National Weather Service Pittsburgh PA 702 PM EDT Wed Apr 17 2024 .SYNOPSIS... Cold front will cross the area this evening bringing thunderstorms. After a brief dry period Thursday, another cold front moving through very late Thursday night and Friday will bring another round of showers before a period of cool and dry weather moves in for Saturday through Monday. && .NEAR TERM /UNTIL 6 AM THURSDAY MORNING/... KEY MESSAGES: - Severe thunderstorms with very large hail and damaging winds until midnight. ------------------------------------------------------------------ For the evening update...refining PoPs with the line of storms moving through the region. Used a blend of hires and blended guidance. Timing of latest hires guidance has sped the eastward movement up just a bit. This lines up well with current radar speeds. Rapid end to the rain behind the front, so PoPs were decreased faster later this evening and overnight. Made some adjustments to late night cloud cover as the threat for stratocu still remains. Rest of the forecast looks goods. Previous discussion... 500 mb trough with 50-60 meter height falls rolls through this evening with associated band of severe thunderstorms along cold front. A band of supercells has formed ahead of the surface cold front and will move steadily into eastern OH, western PA, and northern WV early this evening. MLCAPE of 1,500 J/kg coupled with 7 to 7.5 C/km lapse rates and 0-6 km shear of 40-50 knots supports large to very large hail. The 17z KILN had several SARS analogs with 2"+ hail. LCL values are a bit high for strong tornadoes in the 1,300 m range. However with 20-30 knots of 0-1km shear tornadoes are possible especially in Ohio counties before upscale evolution to a solid squall line focuses threat on wind damage. && .SHORT TERM /6 AM THURSDAY MORNING THROUGH FRIDAY NIGHT/... KEY MESSAGES: - Above normal temperature and dry weather expected for transitory day Thursday. - Another round of showers and low probability thunderstorms expected Friday with cold front passage. ---------------------------------------------------------------- Height rises with 500mb ridge move across area Thursday bring brief period of dry weather with weak surface ridge at the surface. A deep upper low then moves across Ontario Thursday night and Friday with 200 meter height falls into Quebec. Although this is a glancing blow this far south, it does induce a wave of low pressure, pushing a cold front through the Upper Ohio River valley with showers expected starting very late Thursday night in Ohio and moving through rest of area Friday. Heights fall about 80 meters Friday night in wake of cold front and usher in colder air to set up the weekend as 850 mb temperatures fall to about 0C during the night. && .LONG TERM /SATURDAY THROUGH WEDNESDAY/... KEY MESSAGES: - Dry but cooler conditions expected for the weekend. - Periodic shortwave passages may offer brief precipitation windows through the middle of next week. ------------------------------------------------------------------- Dry and cool westerly flow aloft expected Saturday through Monday. A large Canadian High settles into the central CONUS with persistent northwest surface flow and gradually cooling 850 mb temps. By Saturday evening they will drop to -2 to -4C, then -4 to -6C by early Sunday morning. While 30s are possible Saturday night, Sunday night appears to be the coldest with clear skies and light winds creating favorable conditions for radiational cooling. Even though boundary layer starts to warm with 850 mb temps warming close to zero, a sharp inversion is expected with light winds under the surface ridge. NBM 10th percentile Min Temps are in the upper 20s in the north and lower 30s over much of the central potion of forecast area. Given the recent warmth and early start to growing season, we ran the frost tools and widespread frost is expected Sunday night which may eventually require headlines. Trough coming out of Midwest Monday night moves into Great Lakes Tuesday and the northeast states on Wednesday. Showers are possible Tuesday and may linger on Wednesday as a result of strong cold advection and possible lake effect showers. 12z ECMWF even had -10C 850 mb temps reaching into northern PA on Wednesday. && .AVIATION /23Z WEDNESDAY THROUGH MONDAY/... Line of showers and thunderstorms will move through the region until 04z. Will likely be east of ZZV at start of forecast period. Storms could produce strong winds, hail, and frequent lightning. Storms will bring a reduction in vis/cig to mainly MVFR, but iso IFR possible in stronger storms. After line passes to the east, expect a return to VFR for the overnight period for most ports, except at FKL and DUJ where MVFR cigs are expected through most of the forecast period. A brief lowering of cigs is anticipated around dawn. This is a low confidence forecast at this point, but most of the model data is showing this threat. There should be an improvement in conditions by late morning as a return to VFR is anticipated at all ports except FKL and DUJ. .Outlook... Restrictions remain possible Thursday night into Friday under another passing upper trough and associated chances for rain. Prevailing VFR returns over the weekend. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && SYNOPSIS...Craven NEAR TERM...Craven/22 SHORT TERM...Craven LONG TERM...Craven AVIATION...22
Hazardous Weather Outlook National Weather Service Pittsburgh PA 220 PM EDT Wed Apr 17 2024 PAZ009-016-074-076>078-WVZ510>514-181830- Forest-Jefferson PA-Higher Elevations of Westmoreland- Higher Elevations of Fayette-Indiana-Higher Elevations of Indiana- Ridges of Eastern Monongalia and Northwestern Preston-Preston- Eastern Preston-Western Tucker-Eastern Tucker- 220 PM EDT Wed Apr 17 2024 This Hazardous Weather Outlook is for western Pennsylvania and northern West Virginia. .DAY ONE...This afternoon and tonight. There is a marginal risk of severe thunderstorms mainly between 8 and 10 pm this evening with potential for large hail and damaging winds. Heavy rain associated with thunderstorms could also pose a limited flash flood risk given saturated grounds across the region. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. A frost or freeze is expected Saturday night and especially Sunday night. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures. OHZ039>041-048>050-057>059-068-069-PAZ007-008-013>015-020>022-029- 031-073-075-WVZ001>004-012-021-509-181830- Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH- Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Lawrence- Butler-Clarion-Beaver-Allegheny-Armstrong-Washington-Greene- Westmoreland-Fayette-Hancock-Brooke-Ohio-Marshall-Wetzel-Marion- Monongalia- 220 PM EDT Wed Apr 17 2024 This Hazardous Weather Outlook is for east central Ohio, western Pennsylvania, and northern West Virginia. .DAY ONE...This afternoon and tonight. There is a slight risk of severe thunderstorms mainly between 5 and 8 pm this evening with potential for large hail up to golf ball sized and damaging winds. Isolated tornadoes are possible especially in the Ohio Counties. Heavy rain associated with thunderstorms could also pose a limited flash flood risk given saturated grounds across the region. .DAYS TWO THROUGH SEVEN...Thursday through Tuesday. Frost and potentially a freeze is expected Saturday night and especially Sunday night. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures. Craven
Special Weather Statement
National Weather Service Pittsburgh PA
617 PM EDT Wed Apr 17 2024
PAZ008-009-015-172230-
Forest PA-Clarion PA-Venango PA-
617 PM EDT Wed Apr 17 2024
...A STRONG THUNDERSTORM WILL IMPACT EASTERN VENANGO...CENTRAL
CLARION AND SOUTHWESTERN FOREST COUNTIES THROUGH 630 PM EDT...
At 616 PM EDT, Doppler radar was tracking a strong thunderstorm near
Clarion, moving northeast at 35 mph.
HAZARD...Wind gusts of 50 to 55 mph and nickel size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Clarion, Knox, Sligo, Strattanville, Shippenville, Fryburg, and
Fisher.
This includes Interstate 80 in Pennsylvania between mile markers 53
and 64.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until midnight EDT for northwestern
Pennsylvania.
&&
LAT...LON 4130 7921 4129 7921 4110 7946 4113 7954
4126 7959 4142 7946
TIME...MOT...LOC 2216Z 232DEG 31KT 4117 7945
MAX HAIL SIZE...0.88 IN
MAX WIND GUST...55 MPH
HefferanSpecial Weather Statement
National Weather Service Pittsburgh PA
625 PM EDT Wed Apr 17 2024
PAZ020-172245-
Beaver PA-
625 PM EDT Wed Apr 17 2024
...A STRONG THUNDERSTORM WILL IMPACT NORTHERN BEAVER COUNTY THROUGH
645 PM EDT...
At 625 PM EDT, Doppler radar was tracking a strong thunderstorm over
Ohioville, or 7 miles southwest of Beaver Falls, moving northeast at
35 mph.
HAZARD...Wind gusts up to 50 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Beaver Falls, New Brighton, Ohioville, Industry, Patterson Township,
Big Beaver, West Mayfield, Bridgewater, Patterson Heights, Fallston,
Darlington, Eastvale, and Homewood.
This includes the following highways...
Pennsylvania Turnpike between mile markers 13 and 15.
Interstate 376 in Pennsylvania between mile markers 27 and 37.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until midnight EDT for western
Pennsylvania.
&&
LAT...LON 4066 8043 4072 8051 4083 8043 4081 8030
4074 8022
TIME...MOT...LOC 2225Z 227DEG 30KT 4071 8045
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH
HefferanSpecial Weather Statement
National Weather Service Pittsburgh PA
643 PM EDT Wed Apr 17 2024
PAZ009-015-172315-
Forest PA-Clarion PA-
643 PM EDT Wed Apr 17 2024
...A STRONG THUNDERSTORM WILL IMPACT NORTHEASTERN CLARION AND NORTH
CENTRAL FOREST COUNTIES THROUGH 715 PM EDT...
At 643 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles east of Tionesta, or 9 miles west of Marienville, moving
northeast at 30 mph.
HAZARD...Wind gusts of 50 to 55 mph and penny size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Kellettville and Starr.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until midnight EDT for northwestern
and west central Pennsylvania.
&&
LAT...LON 4152 7923 4142 7929 4143 7938 4163 7936
4163 7915
TIME...MOT...LOC 2243Z 207DEG 26KT 4147 7931
MAX HAIL SIZE...0.75 IN
MAX WIND GUST...55 MPH
HefferanSpecial Weather Statement
National Weather Service Pittsburgh PA
645 PM EDT Wed Apr 17 2024
PAZ022-073-077-172300-
Armstrong PA-Westmoreland PA-Indiana PA-
645 PM EDT Wed Apr 17 2024
...A STRONG THUNDERSTORM WILL IMPACT WEST CENTRAL INDIANA...NORTH
CENTRAL WESTMORELAND AND SOUTH CENTRAL ARMSTRONG COUNTIES THROUGH 700
PM EDT...
At 645 PM EDT, Doppler radar was tracking a strong thunderstorm 7
miles northeast of Delmont, or 10 miles southeast of Apollo, moving
northeast at 30 mph.
HAZARD...Wind gusts of 50 to 55 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Avonmore, Saltsburg, West Lebanon, Slickville, and Jacksonville.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until midnight EDT for southwestern
and west central Pennsylvania.
&&
LAT...LON 4040 7942 4043 7953 4067 7949 4058 7924
TIME...MOT...LOC 2245Z 207DEG 26KT 4047 7944
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...55 MPH
HefferanPreliminary Local Storm Report
National Weather Service Pittsburgh PA
700 PM EDT Wed Apr 17 2024
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0640 PM Tstm Wnd Dmg Hanoverton 40.76N 80.94W
04/17/2024 Columbiana OH 911 Call Center
Trees were reported down on Route 30 and on 2nd Street
in Hanoverton.
&&
Event Number PBZ2402514
ShallenbergerSpecial Weather Statement
National Weather Service Pittsburgh PA
700 PM EDT Wed Apr 17 2024
PAZ009-016-172315-
Jefferson PA-Forest PA-
700 PM EDT Wed Apr 17 2024
...STRONG THUNDERSTORMS WILL IMPACT NORTHERN JEFFERSON AND EASTERN
FOREST COUNTIES THROUGH 715 PM EDT...
At 700 PM EDT, Doppler radar was tracking a cluster of strong
thunderstorms 9 miles south of Marienville, moving northeast at 35
mph.
HAZARD...Wind gusts up to 50 mph and pea size hail.
SOURCE...Radar indicated.
IMPACT...Gusty winds could knock down tree limbs and blow around
unsecured objects. Minor hail damage to vegetation is
possible.
Locations impacted include...
Brookville, Marienville, Brockway, Sigel, Clarington, and Clear Creek
State Park.
This includes Interstate 80 in Pennsylvania between mile markers 78
and 90.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
A Tornado Watch remains in effect until midnight EDT for northwestern
and west central Pennsylvania.
&&
LAT...LON 4162 7896 4144 7896 4145 7898 4145 7906
4142 7907 4142 7909 4134 7909 4135 7902
4138 7897 4136 7896 4126 7874 4123 7874
4108 7906 4130 7918 4155 7921 4163 7915
TIME...MOT...LOC 2300Z 228DEG 32KT 4133 7910
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...50 MPH
HefferanThe Pittsburgh radar (KPBZ), 30 km away, was scanning. The volume nearest the first event began at 23:04 UTC.
14 thunderstorm wind. Local standard time, as filed.
Trees down on power lines on Allison Road. Time estimated from radar.
Trees uprooted on Rodgers Road.
Hardwood and softwood trees snapped and uprooted.
Report of tree down on Route 2.
Report of a tree down on power lines along Seven Pines Road.
Report of a tree and power lines down along Ranch Road.
Report of a tree down on power lines along 4th Street.
Report of a tree down on pomerliknes near East Dale Road.
Report of a tree blocking Bunner Ridge Road and nearby power lines down.
Report of a tree down along East Dale Road.
Report of tree along Grafton Road.
Report of tree down and downed power line near Independence Road.
Report of power pole snapped off at top.
Report of tree down at Route 50 and Route 24 blocking West Lane.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in West Virginia in 2024Every state in 2024This day in weather historyWarnings in West Virginia, April 2024
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: 1169395, 1169396, 1169397, 1169398, 1169399, 1169400, 1169401, 1169402, 1169403, 1169404, 1169405, 1169406, 1169407, 1169408.