An approaching cold front was accompanied by a narrow line of thunderstorms as it crossed northwestern Pennsylvania during the afternoon of March 20, 2020. An isolated report of wind damage was received from Elk County as this line of storms passed.
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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.
An approaching cold front was accompanied by a narrow line of thunderstorms as it crossed northwestern Pennsylvania during the afternoon of March 20, 2020. An isolated report of wind damage was received from Elk County as this line of storms passed.
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 Mar 20, 12:28 PM EST, 57 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 128 PM EDT Fri Mar 20 2020 .SYNOPSIS... Unseasonably warm first day of spring with near record highs possible in some locations. Isolated thunderstorms may produce strong to locally damaging wind gusts this afternoon. A dry and chilly weekend expected with a noticeably cooler temperatures. A mix of rain and snow is likely late Sunday night into Monday with snow accumulation most likely over the higher elevations. && .NEAR TERM /THROUGH TONIGHT/... 1030 am update... As the surface warm front lifts to our northeast and the better forced ascent does same, we're seeing the canopy of showers take on a more scattered look to it with time. We expect this trend to continue into the afternoon, as central PA emerges solidly into the warm sector. High resolution satellite loops show that quite a bit of cloud debris remains across the Commonwealth late this morning. Although we do expect some erosion of the clouds this afternoon, the degree of clearing/destabilization we see will certainly have a bearing on thunderstorm coverage/intensity out ahead of an approaching cold front later today. Additionally, as mentioned above, the better upper-level forcing is bypassing the Commonwealth to the north, so convective coverage is also questionable this afternoon. For now, we've not strayed far from the existing forecast, which pretty well details widespread showers diminishing in coverage through midday, but with scattered showers and thunderstorms around this afternoon in advance of the cold front. Given the strength of the wind fields, damaging winds remain a concern with any convective elements, if they can attain sufficient organization (certainly a big if). Even outside of convective cells, steepening low-level lapse rates with the warming boundary layer will combine with the environmental flow to bring the likelihood of 30-40 mph gusts. We're still expecting highs this afternoon to range from the mid 60s in the northern mountains, to the mid-upper 70s in the Lower Susquehanna Valley. Previous discussion... Low visibility falling to 1/4 mile prompted a dense fog advisory for York and Lancaster Counties. May need to expand this to include the Harrisburg area. Expect visibility to improve after sunrise as boundary layer mixing increases and warm front lifts north of the lower Susquehanna Valley. Upstream radar trends and extrapolation show band of showers targeting the northwest 1/2 of the CWA this morning. Cold front pushing east from the Great Lakes and Ohio Valley will trigger another round of showers as it moves across CPA this afternoon and evening. Very strong wind fields overspreading the area combined with weak instability raises the concern for strong to locally damaging wind gusts with any convection that develops along/ahead of cold front/wind shift. SPC has maintained MRGL SWO but should greater buoyancy develop a categorical upgrade to SLGT may occur. This scenario would also favor a potentially more aggressive/organized storm threat. Expect showers to diminish in intensity and shift south of the MD line by later this evening. Post-frontal low clouds are likely over the NW Allegheny Plateau tonight. Dry weather will prevail tonight into the weekend. A big temperature swing is expected in the next 24 hours. Highs this afternoon in the mid 70s across parts of south-central PA will make a run at daily records (see climate section for more info). Highs will be 15 to 25 degrees above normal. Sharply colder temperatures will arrive tonight with mins 15 to 30 degrees colder than this morning. Spreads between todays highs and tonight's lows will reach 40 degrees across northwest PA. && .SHORT TERM /SATURDAY THROUGH SUNDAY/... A dry and chilly first weekend of spring in CPA as 1040mb high migrates eastward from the Upper Midwest into northern Maine by Sunday night. Temperatures will be below average for the majority of the period. Dewpoints may trend lower than forecast on Saturday. Focus will shift toward potential winter event later Sunday night into early Monday. In advance of mid-level wave progressing across the OH Valley, model guidance generally agrees on WAA precip spreading into CPA Sunday night. Temperatures are marginally cold enough to support rain/snow mix over most of the area with snow accumulation most likely over the higher elevations. Adjusted NBM snowfall toward lower accums at elevations AOB 1500ft. Timing of snow and potential for at least moderate rates raises possibility for a few inches even at some lower elevations (central ridge/valley region) along with travel concern for the Monday morning commute. For now will continue to highlight risk via HWO. && .LONG TERM /SUNDAY NIGHT THROUGH THURSDAY/... Ensemble and operational model guidance continue to track a wave of low pressure just south and east of the area Sunday night into Monday. Although the sfc low is progged to be relatively weak, an anomalous easterly flow between this system and a strong area of high pressure over northern New Eng has the potential to produce a late-season snowfall across portions of central PA. Model thermal profiles look cold enough for snow over much of central PA Sunday night into Monday, with either rain or snow southeast of the mountains. The timing of the precip will have an impact on accumulation, as it can be difficult to accumulate snow during the daylight hours in late March, especially on road surfaces. At this point, it appears that there is a decent chance for some accumulating snow across the higher elevations of central PA, with greater uncertainty across the lower elevations of the southeast. We will continue to monitor this impending event, and the finer details will become clearer as the event nears. A brief period of relatively quiet weather is expected Tuesday, before another area of low pressure impacts the area Tues night into Wednesday. Current model thermal profiles and GEFS plumes indicate this system is likely to be mainly rain for all but northeastern PA. && .AVIATION /18Z FRIDAY THROUGH WEDNESDAY/... Frontal system approaching region. This will bring a period of heavy showers and gusty winds with a chance of widely scattered convection with and just ahead of the cold front. Expect showers to diminish in intensity and shift south of the MD line by later this evening. Post-frontal low clouds are likely over the NW Allegheny Plateau overnight. Dry weather will prevail tonight into the weekend with ceiling restrictions lingering over the NW. .Outlook... Sat...Any early morning restrictions from lower ceilings should improve to VFR with time. Sun...VFR during the day, with deteriorating conditions at night in rain or snow. Mon...Restrictions in rain or snow are probable, especially in the morning. Tue...Mainly VFR. && .CLIMATE... Astronomical spring (vernal equinox) occurred at 11:49PM EDT March 19th. Record highs for 3/20: Harrisburg/81 in 1945 Williamsport/76 in 1918 Altoona/75 in 1976 Bradford/71 in 2012 State College/77 in 1948 && .CTP WATCHES/WARNINGS/ADVISORIES... None. && SYNOPSIS...Steinbugl NEAR TERM...Jurewicz/Steinbugl SHORT TERM...Steinbugl LONG TERM...Evanego AVIATION...Ross CLIMATE...
Hazardous Weather Outlook National Weather Service State College PA 524 AM EDT Fri Mar 20 2020 PAZ004>006-010>012-017>019-024>028-033>037-041-042-045-046-049>053- 056-058-063-064-210930- 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-Schuylkill-Cumberland-Adams- 524 AM EDT Fri Mar 20 2020 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and tonight. Isolated thunderstorms capable of producing strong to locally damaging wind gusts are possible this afternoon into the early evening. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. A light snow accumulation is possible late Sunday night into Monday morning, mainly over the higher terrain. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ057-059-065-066-210930- Dauphin-Lebanon-York-Lancaster- 524 AM EDT Fri Mar 20 2020 ...DENSE FOG ADVISORY IN EFFECT UNTIL 8 AM EDT THIS MORNING... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and tonight. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Dense Fog Advisory. Isolated thunderstorms capable of producing strong to locally damaging wind gusts are possible this afternoon into the early evening. .DAYS TWO THROUGH SEVEN...Saturday through Thursday. A light snow accumulation is possible late Sunday night into Monday morning, mainly over the higher terrain. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather.
Special Weather Statement
National Weather Service State College PA
148 PM EDT Fri Mar 20 2020
PAZ004-005-010-201815-
McKean-Warren-Elk-
148 PM EDT Fri Mar 20 2020
...A LINE OF GUSTY SHOWERS WILL AFFECT ELK...EASTERN WARREN AND
MCKEAN COUNTIES...
At 146 PM EDT, radar indicated showers were located along a line
extending from 8 miles south of Belfast to near Clarion. Movement was
east at nearly 60 mph.
Wind gusts up to 50 mph are possible with these showers.
Locations impacted include...
St. Marys, Warren, Bradford, Ridgway, Kane, Johnsonburg, Allegany
State Park, Port Allegany, Sheffield, Smethport, Wetmore, Russell,
Betula, Wilcox, James City, Rew, Crosby, Ludlow, Marshburg and East
Branch Dam.
LAT...LON 4200 7821 4162 7820 4161 7842 4141 7842
4125 7865 4122 7865 4120 7871 4126 7874
4137 7896 4135 7908 4145 7904 4144 7896
4162 7896 4163 7939 4200 7915
TIME...MOT...LOC 1746Z 263DEG 54KT 4222 7810 4118 7946
EvanegoThe State College radar (KCCX), 83 km away, was scanning. The volume nearest the first event began at 18:24 UTC.
1 thunderstorm wind. Local standard time, as filed.
A severe thunderstorm producing winds estimated near 60 mph knocked down a tree across Route 219 near Johnsonburg.
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: 881701.