A cold front approached central Pennsylvania during the afternoon of August 25, 2020. In a moderate CAPE, moderate vertical shear environment, a few of the storms were able to produce wind damage across the Laurel Highlands and southern Alleghenies.
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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 CTP wrote it up.
A cold front approached central Pennsylvania during the afternoon of August 25, 2020. In a moderate CAPE, moderate vertical shear environment, a few of the storms were able to produce wind damage across the Laurel Highlands and southern Alleghenies.
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 State College, PA wrote its last area forecast discussion before the first event at Aug 25, 6:31 AM EST, 1 hour 9 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 731 AM EDT Tue Aug 25 2020 .SYNOPSIS... Thunderstorms capable of damaging wind gusts will be possible this afternoon and early evening. Additional strong to severe storms could occur late Wednesday into Wednesday night and again on Thursday. Rounds of showers and storms are likely from late week into the last weekend in August with Laura forecast to track to the south of Pennsylvania. && .NEAR TERM /THROUGH TONIGHT/... Watching line of storms spreading southeast from the southern tier of upstate NY toward the PA border. This convection should weaken as it moves across the northern tier of CPA later this morning. These storms are associated with a significant shortwave digging over Quebec with an associated cold front progged to advance quickly southeastward across the north- central Appalachians and Mid-Atlantic Piedmont later this afternoon/evening. Max temps should reach the upper 80s to low 90s this afternoon from the south central Alleghenies into the mid and lower Susquehanna Valley. Surface dewpoints in the mid 60s to lower 70s ahead of the front will result in moderate instability across CPA by this afternoon. Steep low-level lapse rates, 1-2k J/kg DCAPE and 40-50kt mid level winds veering to the west-northwest are favorable for damaging wind gusts with multicell clusters that organize into short line segments. The greatest instability and most likely severe potential appears to be across the southern 1/2 of the area. Heavy downpours are possible, but parched soils (in some areas) and storm motions are generally not conducive for more than a localized FF risk in areas that can experience rapid runoff. T-storm threat shifts south of the Mason-Dixon line after 00Z with no precip expected overnight. A cooler and drier (less humid) airmass will arrive behind the cold front bringing a refreshing night and start to Wednesday morning. && .SHORT TERM /WEDNESDAY THROUGH WEDNESDAY NIGHT/... Not much going on during the first half of Wednesday with comfortable airmass gradually retreating into Wednesday night. The aforementioned frontal boundary will pivot and transition to a warm front over the upper OH Valley, which should begin to advance northeast Wednesday night in response to strengthening westerly LLJ. HREF shows instability axis staying to the west of CPA during the day, so at worst would anticipate a stray late- day t-storm possible across the far western Alleghenies adjacent to PBZ CWA. Deeper forcing will increase later in the period which should lead to some elevated t-storms across northwest into north central PA. There is some potential for an MCS to develop if a cold pool can become established. Confidence in overall severe threat (D2 SLGT risk) is on the low-end given conditional threat. Max temps should drop back a few degrees but expect a warmer/muggy night. && .LONG TERM /THURSDAY THROUGH MONDAY/... Above normal temperatures and a jump in dewpoints/PWAT are expected to return by Thursday, as the boundary pushes northeast as a warm front. Scattered strong to severe thunderstorms are possible especially across the northern part of CPA during the day. SPC has introduced a SLGT risk for Thursday/D3. The front will then sag south once again on Friday as the remnants from Tropical Storm Laura usher deep moisture through the Ohio Valley and into Pennsylvania. There is still considerable uncertainty on the southward extent of the front and propagation speed of Laura. A faster cold front will keep Laura's moisture suppressed to the south. A faster Laura could bring more significant moisture into PA, perhaps providing a reprieve from drought conditions. GEFS and ECENS guidance keeps the heaviest rainfall west of the Allegheny front, but with ample uncertainty in Laura's track over the next several days, changes are a guarantee. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... Linear extrapolation and near term models indicate batch of showers and thunderstorms over central Pa at 11Z will diminish and push east of the area by around 14Z. Elsewhere, model soundings indicate patchy low cigs over the western mountains should mix out to vfr conditions by late morning. Focus will then shift to scattered afternoon thunderstorms accompanying the arrival of a cold front. Models indicate the fropa will occur around midday over the northern tier of the state and late afternoon across the southern tier. A brief vis reduction and bout of gusty winds are possible in those spots that see a thunderstorm. Bufkit soundings indicate winds will gust to between 20-25kts this afternoon, shifting from west to northwest as the front passes. High pressure building into the region will bring fair weather and a diminishing breeze tonight. Winds are likely to become light enough for patchy valley fog to form over western Pa by early Wednesday morning. Outlook... Wed...AM valley fog possible W Mtns. Thu...Scattered tsra impacts possible. Fri...AM low cigs possible W Mtns. Scattered PM tsra impacts possible. Sat...AM low cigs possible NW Mtns. PM tsra impacts possible. && .CLIMATE... The high temperature at Bradford reached 84 degrees yesterday afternoon. This tied the record of 84 degrees last set in 1972. && .CTP WATCHES/WARNINGS/ADVISORIES... None. && SYNOPSIS...Steinbugl NEAR TERM...Steinbugl SHORT TERM...Steinbugl LONG TERM...Lambert/Gartner/Banghoff AVIATION...Fitzgerald CLIMATE...
Hazardous Weather Outlook National Weather Service State College PA 428 AM EDT Tue Aug 25 2020 PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053- 056>059-063>066-260830- Warren-McKean-Potter-Elk-Cameron-Northern Clinton-Clearfield- Northern Centre-Southern Centre-Cambria-Blair-Huntingdon-Mifflin- Juniata-Somerset-Bedford-Fulton-Franklin-Tioga-Northern Lycoming- Sullivan-Southern Clinton-Southern Lycoming-Union-Snyder-Montour- Northumberland-Columbia-Perry-Dauphin-Schuylkill-Lebanon-Cumberland- Adams-York-Lancaster- 428 AM EDT Tue Aug 25 2020 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and tonight. Scattered severe thunderstorms with damaging winds 60 mph or greater are possible this afternoon and evening. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. Additional strong to severe thunderstorms are possible Wednesday night and Thursday afternoon. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. MRS
Special Weather Statement
National Weather Service State College PA
425 AM EDT Tue Aug 25 2020
PAZ004-250900-
Warren PA-
425 AM EDT Tue Aug 25 2020
...A STRONG THUNDERSTORM WILL AFFECT PARTS OF WARREN COUNTY UNTIL 500
AM EDT...
At 424 AM EDT, Doppler radar indicated a strong thunderstorm near
Jamestown West, moving southeast at 40 mph.
Wind gusts to around 40 mph are possible.
Locations impacted include...
Warren, Russell, Scandia, Kinzua Dam and Sugar Grove.
LAT...LON 4200 7895 4199 7892 4183 7892 4183 7895
4176 7895 4176 7896 4200 7939
TIME...MOT...LOC 0824Z 302DEG 36KT 4201 7925
KFSpecial Weather Statement
National Weather Service State College PA
811 AM EDT Tue Aug 25 2020
PAZ024-033-251315-
Somerset PA-Cambria PA-
811 AM EDT Tue Aug 25 2020
...STRONG THUNDERSTORMS WILL AFFECT PARTS OF SOMERSET AND CAMBRIA
COUNTIES UNTIL 915 AM EDT...
At 811 AM EDT, Doppler radar indicated strong thunderstorms along a
line extending from near Indiana to 7 miles northeast of Ligonier to
near Monongahela. Movement was southeast at 30 mph.
Wind gusts of up to 55 mph and pea size hail are possible.
Locations impacted include...
Johnstown, Somerset, Westmont, Windber, Ebensburg, Belmont,
Nanty-Glo, Portage, Geistown, Southmont, Cresson, Friedens, Vinco,
Loretto, Boswell, Dale, East Conemaugh, Salix-Beauty Line Park,
Davidsville and Central City.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
These storms may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.
&&
LAT...LON 4007 7926 4012 7921 4011 7919 4012 7917
4016 7916 4018 7913 4036 7900 4058 7887
4047 7854 4037 7856 4035 7861 4028 7865
4026 7864 4008 7873 4006 7876 3993 7877
TIME...MOT...LOC 1211Z 302DEG 25KT 4061 7907 4031 7913 4022 7988
ColbertThe Pittsburgh radar (KPBZ), 104 km away, was scanning. The volume nearest the first event began at 12:38 UTC.
8 thunderstorm wind. Local standard time, as filed.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree at Maggie Road and Keysertown Road to the west of Acosta.
A severe thunderstorm producing winds estimated near 60 mph knocked down trees onto wires just south of Belmont.
A severe thunderstorm producing winds estimated near 60 mph knocked down wires near Boswell.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree onto wires near the intersection of View Avenue and Forest Lane in Jennerstown.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree across both lanes of a roadway near Hollsopple.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree across a roadway near Stoystown.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree at the intersection of Allegheny Road and Geller Road.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree on the 4400 block of Milligan Cover Road.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2020Every state in 2020This day in weather historyWarnings in Pennsylvania, August 2020
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: 914322, 914324, 914325, 914329, 914331, 914332, 914334, 914335.