A deepening low pressure system crossed the Great Lake region on March 20th and promoted heavy rainfall and isolated thunderstorms. As mid-level cool air advanced into the region by late morning, instability increased and helped promote damaging winds.
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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 deepening low pressure system crossed the Great Lake region on March 20th and promoted heavy rainfall and isolated thunderstorms. As mid-level cool air advanced into the region by late morning, instability increased and helped promote damaging winds.
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 Mar 20, 5:32 AM EST, 1 hour 15 minutes earlier.
Area Forecast Discussion National Weather Service Pittsburgh PA 632 AM EDT Fri Mar 20 2020 .SYNOPSIS... Occasional showers and thunderstorms are expected today with crossing low pressure. Dry and cooler weather should return for the weekend under high pressure. && .NEAR TERM /THROUGH TONIGHT/... AM Update... Training showers and thunderstorms with high rainfall rates upwards of 0.50 inch/hour on already saturated surfaces are tracking East from Central Ohio. The majority of the heavy accumulation has occurred in Eastern Ohio and upstream in Central Ohio. Flash flooding is likely occurring in these areas. Previous Discussion...Heavy rain showers and isolated thunderstorms, associated with passing shortwave, are expected to advance across our region this morning. The combination of a strengthening low-level jet over southern Ohio, high PWAT values (1.3-1.4 inches), and dewpoints in the low-60s will create impressive rainfall rates. Throughout the day temperature will rise 20 degrees above the climatological average as we continue to receive strong southeast jet support. With temperatures lingering in the low-70s low- level lapse rates will steepen and windy conditions (gusts near 30-35mph) will occur quickly after sunrise. By late morning, mid- level dry is anticipated to quickly advance into Western PA prior to the passage of a cold front. The interference of dry air will help cool the temp profile aloft and increase instability just as the front passes. A few isolated strong storms may be embedded in or just ahead of the front is expected. Given deep- layer shear profile (50kts from the sfc to 9,000ft) and sufficient boundary layer mixing, high damaging winds would be the main threat with the better- organized storms. Currently the Storm Prediction Center has our entire region under a Marginal risk, however reassessment later in the day may raise that threat to a Slight. In the wake of the cold front, a tight pressure gradient is expected to linger. Gusts up to 35 mph may continue across the region (40 mph in the ridges) tonight and early tomorrow morning. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... Dry but cooler weather is foreseen over the weekend as high pressure builds over the Midwest and cold advection prevails under NW flow through Sunday morning. Temperature were projected about 5 degrees under the averages. As high pressure advances to our east, winds will shift and southerly flow will return. Temperatures Sunday afternoon will rebound back to the climatological average. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... An upper-level trough is expected to return rain to the region early Monday. With high pressure shifting over New England, cold advection is expected to prevail over Central PA; a rain/snow mix may occur for areas north of I-80. Rain is anticipated Wednesday with a quick moving shortwave. Models project above average temperatures Thursday and may carry into the weekend as a strong ridge builds over the East Coast. && .AVIATION /12Z FRIDAY THROUGH TUESDAY/... The majority of terminals have VFR conditions currently, with scattered showers moving northeast across the region. The next round of showers, with a few thunderstorms, is lining up over central Ohio as the low-level jet strengthens and pushes deeper moisture back into the region. Low-level wind shear will remain a concern into mid- morning with wind of 45-50 knots just off the surface. Generally MVFR ceiling/visibility can be expected with these showers, but brief IFR conditions in thunderstorms cannot be ruled out. A brief period of improvement is expected during the late morning/early afternoon hours, during which increased mixing and a tighter pressure gradient will allow wind gusts out of the southwest to increase to around 30 knots. Then, a crossing cold front is expected to bring showers and scattered thunderstorms as it drops across the region. A shift to W and eventually NW wind is forecast behind the front, along with lingering MVFR ceilings. .Outlook... Restrictions are possible behind the exiting front thru early Sat. Restrictions are likely again Sun night and Mon with crossing low pressure. && .PBZ WATCHES/WARNINGS/ADVISORIES... MD...None. OH...None. PA...None. WV...None. &&
Hazardous Weather Outlook National Weather Service Pittsburgh PA 218 AM EDT Fri Mar 20 2020 MDZ001-PAZ007>009-013>016-020>023-029-031-073>076-WVZ001>004-012-021- 509>514-210630- Garrett-Mercer-Venango-Forest-Lawrence-Butler-Clarion-Jefferson PA- Beaver-Allegheny-Armstrong-Indiana-Washington-Greene-Westmoreland- Westmoreland Ridges-Fayette-Fayette Ridges-Hancock-Brooke-Ohio- Marshall-Wetzel-Marion-Monongalia- Ridges of Eastern Monongalia and Northwestern Preston-Preston- Eastern Preston-Western Tucker-Eastern Tucker- 218 AM EDT Fri Mar 20 2020 This Hazardous Weather Outlook is for western Maryland, northwest Pennsylvania, southwest Pennsylvania, western Pennsylvania, northern West Virginia and the northern panhandle of West Virginia. .DAY ONE...Today and tonight. Thunderstorms are expected to form with an advancing cold front today. A few storms may be severe and cause damaging wind gusts this afternoon. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures. OHZ039>041-048>050-057>059-068-069-210630- Tuscarawas-Carroll-Columbiana-Coshocton-Harrison-Jefferson OH- Muskingum-Guernsey-Belmont-Noble-Monroe- 218 AM EDT Fri Mar 20 2020 This Hazardous Weather Outlook is for east central Ohio. .DAY ONE...Today and tonight. Additional rainfall this morning may trigger isolated flooding. Thunderstorms are expected to form with an advancing cold front today. A few storms may be severe and cause damaging wind gusts this afternoon. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. Hazardous weather is not expected at this time. .SPOTTER INFORMATION STATEMENT... Weather spotters are encouraged to report significant weather conditions according to Standard Operating Procedures.
Special Weather Statement
National Weather Service Pittsburgh PA
523 AM EDT Fri Mar 20 2020
OHZ039-040-048-049-057>059-201015-
Guernsey-Tuscarawas-Coshocton-Harrison-Muskingum-Belmont-Carroll-
523 AM EDT Fri Mar 20 2020
...A STRONG THUNDERSTORM CAPABLE OF PRODUCING GUSTY WIND AND HEAVY
RAIN WILL AFFECT WESTERN HARRISON...GUERNSEY...COSHOCTON...NORTHERN
MUSKINGUM...SOUTHWESTERN CARROLL...NORTHWESTERN BELMONT AND
TUSCARAWAS COUNTIES...
At 523 AM EDT, a strong thunderstorm was located near Dresden, or 8
miles southwest of Coshocton, moving east at 55 mph.
Wind gusts up to 45 mph are possible with this storm.
Locations impacted include...
Zanesville... New Philadelphia...
Coshocton... Cambridge...
Uhrichsville... Freeport...
Newcomerstown... Dennison...
New Concord... Byesville...
West Lafayette... North Zanesville...
This includes the following highways...
Interstate 70 in Ohio near mile marker 145, and between mile
markers 161 and 208.
Interstate 77 in Ohio between mile markers 43 and 80.
Torrential rainfall also is occurring with this storm and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.
LAT...LON 4005 8220 4023 8218 4025 8220 4028 8219
4044 8168 4047 8167 4053 8108 4001 8105
3995 8219
TIME...MOT...LOC 0923Z 256DEG 57KT 4017 8195The Pittsburgh radar (KPBZ), 31 km away, was scanning. The volume nearest the first event began at 11:45 UTC.
4 thunderstorm wind, 2 flood. Local standard time, as filed.
A number of roads were affected by heavy rain near Oakdale, Penn Hills, West Mifflin, and Verona. Reports were made by the public, 911, and local fire department.
According to a local 911 Call Center, a tree blew down on Arlington Drive.
According to 911 Call Center, trees were down along SR-62.
According to 911 Call Center, wires were down on East Broadway Ave.
The county Emergency Manager reported numerous trees down across the county.
Urban street flooding and flooding due to swollen creeks affected areas across Beaver County and northwestern Allegheny County.
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, March 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: 879209, 879205, 879206, 879207, 879208, 879211.