Spotty lake-effect and upslope snow showers dusted the western highlands of Pennsylvania with snow during the early morning hours of November 23, 2021. Resultant slick roads in Clearfield County led to an accident that closed the westbound lanes of I-80 for two hours near mile marker 120.
Every event with a place to put it; 1 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 CTP wrote it up.
Spotty lake-effect and upslope snow showers dusted the western highlands of Pennsylvania with snow during the early morning hours of November 23, 2021. Resultant slick roads in Clearfield County led to an accident that closed the westbound lanes of I-80 for two hours near mile marker 120. There were no injuries reported.
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 Nov 23, 5:38 AM EST, 39 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 538 AM EST Tue Nov 23 2021 .SYNOPSIS... Lake effect snow showers will taper off later today. Temperatures will moderate through Thanksgiving. Wednesday and Thanksgiving Day both look dry. Another cold front will bring some showers into western PA Thursday evening. Below normal temperatures are expected for Friday into early next week. Aside from some showers across the northwestern and western mountains, dry conditions are expected across the Keystone state for the weekend. && .NEAR TERM /UNTIL 6 PM THIS EVENING/... Winds are more in line now for some bands of snow showers early this morning. The airmass is rather dry compared the event last Monday. Heights rise later today, which will not favor much in the way of lake effect snow bands. The event last Monday evening looked a bit better on radar, but only light amounts occurred. Thus the best potential for anything significant will be the next few hours, once we get past sunrise. Made a few more minor changes to the POPS and weather today. Will continue the winter weather advisory across the far northwest for now, and continue to monitor conditions. Did trim snow amounts by a hair. Advisory in effect until 4 PM. Winds will remain on the gusty side, as pressure gradiant increases some. && .SHORT TERM /6 PM THIS EVENING THROUGH THURSDAY/... Clearing skies and low dewpoints will support temperatures falling into the teens in some spots by Wednesday morning. Sfc ridge axis builds eastward this evening shutting off the lake effect and veering winds more to the WSW by Wednesday morning. Mins will range from the upper teens north to the lower to mid 20s southeast. Surface high pressure over the area on Wednesday slides southeast of central PA by Wednesday afternoon. Therefore, expect a warmup into the 40s for most on Wednesday along with mostly sunny skies early in the day before high clouds stream in from the west. && .LONG TERM /THURSDAY NIGHT THROUGH MONDAY/... Focus then shifts to a low pressure system digging from Ontario into the Ohio Valley Thanksgiving Day into the weekend. Rain chances will subsequently pick up later Thursday into Thursday night, mixing with and transitioning to snow showers across the Alleghenies on Friday as another dose of cold Canadian air spills into central PA. Following high temperatures in the mid 40s to mid 50s on Thanksgiving, readings will remain 10 or more degrees colder for Friday. Wind chills will once again take a nosedive as breezy west/northwest winds persist and make for additional lake effect snow across NW PA. Post frontal cold temperatures, gusty winds, and snow showers appear in the offing through the weekend with northwest flow in place aloft. May see another shortwave trough or two dig through, maintaining the theme of unsettled/cold weather. && .AVIATION /12Z TUESDAY THROUGH SATURDAY/... Gusty west to northwest flow will bring colder air and lake effect snow showers to the northwest and west, mainly this morning. Dry low level air has helped all airfields stay VFR through the overnight, although BFD may see MVFR cigs move in towards daybreak as clouds and snow showers continue downwind of Lake Erie. There could also be some moments of IFR vsby in lake effect snow showers INVOF BFD this morning. Expect VFR conditions this afternoon as snow showers diminish. Outlook... Wed-Thu...VFR. No sig wx Thu night...Showers/restrictions possible with next frontal system. Fri-Sat...Breezy NW flow, snow showers mainly NW. && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Weather Advisory until 4 PM EST this afternoon for PAZ004-005. && SYNOPSIS...DeVoir/Martin NEAR TERM...DeVoir/Martin SHORT TERM...DeVoir/Martin LONG TERM...Guseman/DeVoir/Colbert AVIATION...Martin/Colbert/Gutierrez
Hazardous Weather Outlook National Weather Service State College PA 404 AM EST Tue Nov 23 2021 PAZ006-010>012-017>019-024>028-033>037-041-042-045-046-049>053- 056>059-063>066-240915- 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- 404 AM EST Tue Nov 23 2021 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...Today and tonight. The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotter activation is not expected at this time. PAZ004-005-240915- Warren-McKean- 404 AM EST Tue Nov 23 2021 ...WINTER WEATHER ADVISORY IN EFFECT UNTIL 4 PM EST THIS AFTERNOON... 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. Winter Weather Advisory. .DAYS TWO THROUGH SEVEN...Wednesday through Monday. The probability for widespread hazardous weather is low. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. Martin
The national radar mosaic for the moment the first event began.
1 winter weather. Local standard time, as filed.
Snow showers produced slick road conditions on I-80 westbound near mile marker 120 in Clearfield County, resulting an accident that prompted the closing of the westbound lanes for two hours. There were no injuries reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2021Every state in 2021This day in weather historyWarnings in Pennsylvania, November 2021
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: 986806.