A couple severe storms developed along a pre-frontal trough later in the afternoon after partial clearing of cloud coverage allowed for increased instability. DCAPE was over 1000 J/kg, resulting in an environment favorable for microbursts.
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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 PBZ wrote it up.
A couple severe storms developed along a pre-frontal trough later in the afternoon after partial clearing of cloud coverage allowed for increased instability. DCAPE was over 1000 J/kg, resulting in an environment favorable for microbursts.
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 Jun 14, 6:46 AM EST, 4 hours 24 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 746 AM EDT Fri Jun 14 2024 .SYNOPSIS... A cold front will bring scattered thunderstorms on Friday, some could be strong to severe. Dry with seasonable temperatures Saturday ahead of a high confidence, potentially historic, prolonged period of dangerous heat next week. && .NEAR TERM /THROUGH TONIGHT/... KEY MESSAGES: - Cold front will bring showers and thunderstorms with a 1/5 risk for severe weather. - Temperatures right around normal. ------------------------------------------------------------------- Minor tweaks to sky cover this morning, as well as upping PoPs briefly in the ZZV area for a patch of showers. No other changes at 730 AM. Previous discussion... Convection off to our west overnight has thrown convective debris clouds over the area as a few scattered and light showers move through. Most will remain dry through this morning ahead of a cold front and an upper wave that will sag through later today with showers and thunderstorms developing along the boundary. Latest hi res ensemble guidance suggests an initial batch may move across eastern Ohio and western Pennsylvania around noontime with weak convergence ahead of the boundary, but this is lower confidence with overnight RAP/HRRR runs waffling back and forth. Should it materialize, it will exist in an environment that hasn't had much time to destabilize with instability maxing out around 700 J/kg so this shouldn't be too impactful. The front itself will then move through and try to reinvigorate additional development along it, but the wrinkle would be if there is any earlier rain/cloud cover it may limit how much the atmosphere can recover. Most likely ensemble timing of the front to the Pittsburgh metro is in the 3-4pm window when the ensemble probability of >1000 J/kg of CAPE and >30 knots of shear only sits around 30-40%, likely a byproduct of its earlier convection. Without contamination, instability may reach up to around 1000-1500 J/kg. Primary threats will be damaging wind and hail, and the entire area is outlined in a 1/5 risk for severe. With ensemble mean precipitable water values nearing 1.4-1.5", any thunderstorm could bring a heavy downpour with it as well, so some isolated flooding concerns can't be ruled out. A push of drier and cooler air will arrive in northwest flow behind the front and drop lows Friday night to a couple ticks below normal. Could see some areas of river valley fog develop with highest probabilities south of Pittsburgh in the 30-40% range. && .SHORT TERM /SATURDAY THROUGH SUNDAY NIGHT/... KEY MESSAGES: - Dry weather Saturday and Sunday. - Near normal temperatures Saturday with a jump to 5-10 degrees above normal on Sunday. ------------------------------------------------------------------- Heights rise into Saturday as upper ridging builds and surface high pressure slides in to the north. Temps won't rebound much in northerly flow in the wake of the boundary and dew points will likely mix out some in the afternoon with a dry boundary layer providing a pretty comfortable day. Upper ridging begins to build stronger making a run at 588-590dm by Sunday to kick off the first day of increasingly hot conditions. Surface high pressure establishes off to our east and southwest flow on the west side of the 850 mb ridge axis will induce warm advection with ensemble 850 temps up to 15-17C. This will support widespread upper 80s with even a 40-70% chance of 90F+ for Pittsburgh south and west. && .LONG TERM /MONDAY THROUGH THURSDAY/... KEY MESSAGES: - High confidence in a dangerous heat wave setting up early next week with major heat impacts possible. ------------------------------------------------------------------- Guidance has been consistent that a potentially-historic ridge will continue to strengthen across much of the central and eastern CONUS into the middle of next week. WPC ensemble clusters are highly consistent through Tuesday, indicating high confidence in the temperature forecast. Near-record breaking heat will build in to start off next week. Significant heat is looking increasingly likely with this anomalously strong ridge from Monday and beyond when major to extreme heat risk is likely. NBM probabilities for high temperatures reaching 95+ degrees continue to go up, and are now widespread 60-90% across the area. These higher probabilities are especially prevalent in lower elevation areas (e.g., river valleys) and urban centers, which tend to be warmer than surrounding areas. In addition, dewpoints are currently forecast to remain in the mid 60s to lower 70s, which would result in high enough humidity levels to support heat indices climbing to, and potentially exceeding, 100 degrees. If dew points do hold toward the lower end of that spectrum, we may be able to make a run at 100 degree air temperatures Monday and beyond (last time at PIT was 7/15/95); NBM probabilities for that threshold are now up to 60% on Tuesday with ~50% chance for the remainder of the week. Only acting to exacerbate the prolonged heat effects will be a 60-80% chance of low temperatures greater than 70 degrees through the end of the week. Heat impacts will need to be closely monitored and headlines may need to be considered. Three out of four clusters maintain at least a 594dm ridge through June 22nd with the one exception being a lower probability solution than the others. Return intervals of these heights dating back to 1979 are just about out of the climatological range. CPC suggests that excessive heat may last through June 24th, indicating the potential for a long-duration excessive heat threat. The last comparable, long-duration heat event was from July 1994. Impacts include heightened heat-related illnesses and potential power grid issues with increased demand. It is strongly encouraged to know where cooling shelters are located and stay hydrated. There may be little relief at night. Gather food, water and medication now. Make a list of friends and family to check on and help them prepare. Strongly consider rescheduling outdoor events. Prolonged exposure to excessive heat was the primary cause of weather-related fatalities in 2023. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... VFR conditions will prevail through a good part of the TAF period. However, the approach and passage of a cold front today will bring scattered to numerous showers and thunderstorms as it crosses. The period of restrictions at any one terminal should be relatively brief, and have used PROB30 groups to illustrate the best timing window at each site. Any thunderstorm could cause a brief drop to MVFR ceilings and IFR visibility. The strongest storms could bring LIFR visibility in downpours and variable wind gusts to 40 knots, but confidence in these impacts at any one TAF site is quite low and thus not mentioned in the TAFs. In the wake of the front, winds shift to northwesterly and skies begin to clear again as drier air moves into the region. Patchy valley fog may be a concern late tonight. .Outlook... Largely VFR conditions are then forecast Saturday through Tuesday as a strong ridging pattern develops over the region. && .PBZ WATCHES/WARNINGS/ADVISORIES... PA...None. OH...None. WV...None. && SYNOPSIS...MLB NEAR TERM...MLB/CL SHORT TERM...MLB LONG TERM...MLB/Milcarek AVIATION...CL
Hazardous Weather Outlook National Weather Service Pittsburgh PA 314 AM EDT Fri Jun 14 2024 OHZ039>041-048>050-057>059-068-069-PAZ007>009-013>016-020>022-029- 031-073>078-WVZ001>004-012-021-509>514-150715- Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH- Muskingum-Guernsey-Belmont-Noble-Monroe-Mercer-Venango-Forest- Lawrence-Butler-Clarion-Jefferson PA-Beaver-Allegheny-Armstrong- Washington-Greene-Westmoreland-Higher Elevations of Westmoreland- Fayette-Higher Elevations of Fayette-Indiana- Higher Elevations of Indiana-Hancock-Brooke-Ohio-Marshall-Wetzel- Marion-Monongalia- Ridges of Eastern Monongalia and Northwestern Preston-Preston- Eastern Preston-Western Tucker-Eastern Tucker- 314 AM EDT Fri Jun 14 2024 This Hazardous Weather Outlook is for east central Ohio, western Pennsylvania, and northern West Virginia. .DAY ONE...Today and tonight. Thunderstorms are possible on Friday along a passing cold front. A few could become strong to severe with hail and damaging straight- line wind as the primary threats. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. There is high confidence in a prolonged, potentially dangerous period of excessive heat beginning Sunday and continuing through next week that may result in major heat-related impacts across the area, especially in traditionally warmer locations like valleys and urban centers. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. MLB
Special Weather Statement
National Weather Service Pittsburgh PA
1140 AM EDT Fri Jun 14 2024
PAZ015-016-141615-
Jefferson PA-Clarion PA-
1140 AM EDT Fri Jun 14 2024
...A STRONG THUNDERSTORM WILL IMPACT SOUTHWESTERN JEFFERSON AND
SOUTHEASTERN CLARION COUNTIES THROUGH 1215 PM EDT...
At 1139 AM EDT, Doppler radar was tracking a strong thunderstorm 7
miles west of Brookville, moving east at 35 mph.
HAZARD...Wind gusts up to 40 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, Strattanville, Summerville, Limestone, Corsica, and
Knox-Dale.
This includes Interstate 80 in Pennsylvania between mile markers 65
and 89.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
Torrential rainfall is also occurring with this storm and may lead to
localized flooding. Do not drive your vehicle through flooded
roadways.
Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.
&&
LAT...LON 4108 7938 4123 7934 4121 7891 4101 7895
TIME...MOT...LOC 1539Z 277DEG 28KT 4114 7922
MAX HAIL SIZE...0.25 IN
MAX WIND GUST...40 MPH
CLSpecial Weather Statement
National Weather Service Pittsburgh PA
1157 AM EDT Fri Jun 14 2024
PAZ016-141630-
Jefferson PA-
1157 AM EDT Fri Jun 14 2024
...A STRONG THUNDERSTORM WILL IMPACT CENTRAL JEFFERSON COUNTY THROUGH
1230 PM EDT...
At 1157 AM EDT, Doppler radar was tracking a strong thunderstorm near
Brookville, moving east at 40 mph.
HAZARD...Wind gusts up to 40 mph and half inch 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, Reynoldsville, Brockway, Sykesville, Falls Creek, Big
Run, Worthville, Knox-Dale, and Anita.
This includes Interstate 80 in Pennsylvania between mile markers 77
and 96.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
If outdoors, consider seeking shelter inside a building.
&&
LAT...LON 4120 7877 4113 7880 4091 7881 4091 7883
4103 7917 4121 7912 4126 7874 4123 7874
4123 7871 4120 7871
TIME...MOT...LOC 1557Z 280DEG 35KT 4111 7905
MAX HAIL SIZE...0.50 IN
MAX WIND GUST...40 MPH
ShallenbergerThe State College radar (KCCX), 77 km away, was scanning. The volume nearest the first event began at 16:09 UTC.
2 thunderstorm wind. Local standard time, as filed.
Trees and powerlines down multiple locations near Reynoldsville.
Local fire department reported multiple trees and power lines down in the area between Rollton and Lowber.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2024Every state in 2024This day in weather historyWarnings in Pennsylvania, June 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: 1197605, 1197606.