A long-duration winter storm produced widespread snowfall across central Pennsylvania from January 31 to February 2, 2021. Although the snow began on January 31st, warning criteria was not met in any central Pennsylvania counties until February 1st or 2nd.
Every event with a place to put it; 29 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.
A long-duration winter storm produced widespread snowfall across central Pennsylvania from January 31 to February 2, 2021. Although the snow began on January 31st, warning criteria was not met in any central Pennsylvania counties until February 1st or 2nd. Widespread snowfall amounts of 10-15 inches were observed, with more than 20 inches of accumulation in portions of Schuylkill County. This was a Miller Type B storm, with the primarily low pushing up the Ohio Valley before a center-jump to the Mid-Atlantic coast was observed. Snow was the predominant precipitation type, although the Lower Susquehanna Valley had a several hour period of light wintry mix before the coastal low strengthened. The system then very slowly pulled east-northeastward along the southern New England coast and out to sea.
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 Jan 31, 10:58 PM EST, 1 hour 2 minutes earlier.
Area Forecast Discussion National Weather Service State College PA 1058 PM EST Sun Jan 31 2021 .SYNOPSIS... A winter storm will impact central PA with snow and travel disruptions to close out January and begin February. Snow will gradually taper off for Groundhog Day with a drying trend through midweek. The next weather system is forecast to arrive by late in the week. && .NEAR TERM /UNTIL 6 AM MONDAY MORNING/... Convergence associated with 850 mb jet nosing into SC PA from offshore mid Atlantic region is increasing coverage of light to moderate snow over most of central PA late this evening. Rates are slowly creeping up but remain mostly less than one inch per hour. Dry slot is impinging on southern tier counties but so far no changeover reported in METARS. Expect to change during the overnight hours as dry slot penetrates further into the southern tier of central PA. North of the dry slot, trend of expanding radar returns the last few hours should continue into the overnight hours as 850 mb jet increases convergence over most of central/SC PA. Latest NAM is focusing best snowfall overnight in an east to west band that extends from just north of the I80 corridor southward to Rt 30 where generally 2 to 4 inches of additional overnight accumulation is expected, with slightly lesser amounts north and south. Mixing across the far south will introduce some light glaze into the equation, but amounts will be light. && .SHORT TERM /6 AM MONDAY MORNING THROUGH TUESDAY NIGHT/... Strong easterly 850 mb jet will be the focus for heaviest snowfall Monday morning through Monday evening with frontogenetical bands aimed from the Lehigh Valley to the Pocono Plateau westward to the Lycoming Valley and Endless Mountains. HREF targets the 18z Mon to 08z Tue timeframe at the nose of this feature as being most likely to see some 1" per hour snowfall rates...with lowest probs over the Lycoming Valley and highest likelihood of >1"/hr rates over Sullivan and Bradford Counties. These areas could be the sweet spot, and end up with the locally 18"+ that we've been attempting to pinpoint the past 24-36 hours. That being said, certainty in placing highest amounts is very difficult at this time and will be monitored closely as we get closer to Monday PM. Expect wintry mix to transition back to snow by midday Monday across the south with increasing snow rates through Monday afternoon. 18z runs and first glance at 00z NAM renews concern for 12"+ amounts at the nose of the 850 mb easterly jet focused from the Lehigh Valley westward to Schuylkill/Columbia/Sullivan Counties westward along the I80 corridor. Probabilistic guidance prompted slight increase of amounts in those areas with early and mid evening updates. We expect there to be further adjustments and refinements to the Mon PM and night snow accums given orientation and intensity of pivoting fgen/deformation band. We were still keen to place the highest POPs and heaviest snowfall over the NE zones at this time. As the coastal low deepens, gusty northerly winds are expected over the far eastern parts of the area with max gusts in the 30-35 mph range early Monday. A tightening pressure gradient west of intensifying low over eastern New England will result in increasingly gusty northwest winds across central Pa by Tuesday as lighter snow/snow showers linger over eastern Pa with deformation zone west of mid level low. Bufkit soundings support frequent gusts to around 25kts by afternoon, which could produce some blowing/drifting in open/exposed locations. The airmass following this system looks seasonably chilly at best. GEFS 925mb temps of -5C to -8C support highs from the mid 20s over the northwest mountains, to the mid 30s over the Lower Susq Valley. && .LONG TERM /WEDNESDAY THROUGH SUNDAY/... In the wake of departing low, a chilly brisk north wind will persist into Wednesday, with wind chills in the single digits and teens Wednesday through Thursday morning. Other than a few flurries on Wednesday, dry weather will persist through Thursday as a high pressure ridge builds in with temperatures trending warmer to above average into late week. By late week, guidance finally starting to come into some better agreement with the amplitude and speed of an upper level trough moving in from the west. Trough dropping across the midwest with developing surface low over the Great Lakes will lift a warm front through Thursday night followed by a cold front on Friday, brushing mainly western areas with precipitation. Generally light snow for the NW and light rain for the SE, though steadiest precip remains confined to NW half of CWA into the weekend. By Sunday/Monday model differences return as GFS more aggressive with next trough riding up the old frontal boundary along the east coast and the EC about a day behind. So had to smear precip chances out across a few days to account for these timing differences. GFS solution would be a bit warmer while EC will bring surface low across with colder air in place. Development of this system for late next weekend bears watching for potential winter impacts in PA. Either way, behind this system a colder airmass drives in from the NW with brisk winds and colder temperatures. && .AVIATION /04Z MONDAY THROUGH FRIDAY/... Long duration of IFR in varying intensity snow (vis dropping below 1SM at times) expected to continue overnight. A wintry mix is likely over the southeast airfields after midnight lasting into the mid- morning hours. A strong easterly llj will produce some low level wind shear in the eastern airfields starting before daybreak tomorrow and continuing into the afternoon. Snow and IFR conditions redevelop in the southeast and continue elsewhere throughout the day tomorrow. A period of +SN is possible in the east (IPT most likely, but MDT/LNS and UNV possible) late in the day as a band of snow intensifies west of a rapidly- deepening surface low off the east coast. Snow will gradually taper off overnight from west to east as cigs/vis gradually improve. Outlook... Tue...Breezy with snow tapering off. 20-25kt wind gusts from 280-310 degrees. Wed...Breezy with 20-25kt wind gusts from 280-310 degrees. Thu...No sig wx. Thu night-Fri...Reductions possible in mixed pcpn. && .CTP WATCHES/WARNINGS/ADVISORIES... Winter Storm Warning until 5 AM EST Tuesday for PAZ012-018-019- 024>028-033>037-041-042-045-046-049>053-056>059-063>066. Winter Weather Advisory until 5 AM EST Tuesday for PAZ006-010- 011-017. && SYNOPSIS...DeVoir/Steinbugl NEAR TERM...DeVoir/Steinbugl SHORT TERM...DeVoir/Steinbugl LONG TERM...DeVoir/RXR/Banghoff AVIATION...Steinbugl/Banghoff
Hazardous Weather Outlook National Weather Service State College PA 236 PM EST Sun Jan 31 2021 PAZ012-018-019-024>028-033>037-041-042-045-046-049>053-056>059- 063>066-011945- Northern Clinton-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- 236 PM EST Sun Jan 31 2021 ...WINTER STORM WARNING IN EFFECT UNTIL 5 AM EST TUESDAY... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...This afternoon 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 Storm Warning. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Please listen to NOAA Weather Radio or go to weather.gov/StateCollege on the internet for more information about the following hazards. Winter Storm Warning. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ004-005-011945- Warren-McKean- 236 PM EST Sun Jan 31 2021 This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...This afternoon and tonight. Periods of snow at varying intensity will continue through tonight. .DAYS TWO THROUGH SEVEN...Monday through Saturday. Periods of snow will continue through Monday night with total accumulations of 3 to 6 inches expected. The snow will result in slippery roads, reduced visibility, and travel disruptions. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. PAZ006-010-011-017-011945- Potter-Elk-Cameron-Clearfield- 236 PM EST Sun Jan 31 2021 ...WINTER WEATHER ADVISORY IN EFFECT UNTIL 5 AM EST TUESDAY... This Hazardous Weather Outlook is for central Pennsylvania. .DAY ONE...This afternoon 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...Monday through Saturday. 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. .SPOTTER INFORMATION STATEMENT... Spotters are encouraged to report significant hazardous weather. MS
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
951 PM EST SUN JAN 31 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0940 PM SNOW MECHANICSBURG 40.21N 77.01W
01/31/2021 E4.0 INCH CUMBERLAND PA PUBLIC
REPORTED AT MECHANICSBURG, PA.
&&
ANWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
954 PM EST SUN JAN 31 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0930 PM SNOW DANVILLE 40.96N 76.62W
01/31/2021 M3.0 INCH MONTOUR PA PUBLIC
&&
ANWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
958 PM EST SUN JAN 31 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0958 PM SNOW 1 WNW PARK FOREST 40.81N 77.92W
01/31/2021 M3.0 INCH CENTRE PA NWS EMPLOYEE
&&
JRBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1012 PM EST SUN JAN 31 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1000 PM SNOW 1 S LEBANON 40.33N 76.43W
01/31/2021 E4.5 INCH LEBANON PA PUBLIC
REPORTED AT LEBANON, PA.
&&
ANWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1029 PM EST SUN JAN 31 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1028 PM SNOW 1 NNW MOUNT GRETNA 40.25N 76.48W
01/31/2021 E4.0 INCH LEBANON PA PUBLIC
&&
ANWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE STATE COLLEGE PA
1112 PM EST SUN JAN 31 2021
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
1050 PM SNOW 3 E MARION 39.87N 77.61W
01/31/2021 M4.5 INCH FRANKLIN PA PUBLIC
REPORTED AT GUILFORD SIDING.
&&
ANWThe national radar mosaic for the moment the first event began.
29 winter storm. Local standard time, as filed.
A winter storm produced 8 to 12 inches of snow across Adams County from January 31 to February 2, 2021.
A winter storm produced around 8 inches of snow across Bedford County from January 31 to February 2, 2021.
A winter storm produced 8 to 10 inches of snow across Blair County from January 31 to February 2, 2021.
A winter storm produced 8 to 12 inches of snow across Columbia County from January 31 to February 2, 2021.
A winter storm produced 10 to 16 inches of snow across Cumberland County from January 31 to February 2, 2021.
A winter storm produced 16 to 20 inches of snow across Franklin County from January 31 to February 2, 2021.
A winter storm produced 9 to 16 inches of snow across Fulton County from January 31 to February 2, 2021.
A winter storm produced 9 to 13 inches of snow across Huntingdon County from January 31 to February 2, 2021.
A winter storm produced around 12 inches of snow across Juniata County from January 31 to February 2, 2021.
A winter storm produced 9 to 16 inches of snow across Lancaster County from January 31 to February 2, 2021.
A winter storm produced 10 to 16 inches of snow across Lebanon County from January 31 to February 2, 2021.
A winter storm produced 10 to 13 inches of snow across Mifflin County from January 31 to February 2, 2021.
A winter storm produced 11 to 14 inches of snow across Montour County from January 31 to February 2, 2021.
A winter storm produced 9 to 11 inches of snow across northern Centre County from January 31 to February 2, 2021.
A winter storm produced 8 to 10 inches of snow across northern Clinton County from January 31 to February 2, 2021.
A winter storm produced 9 to 11 inches of snow across northern Lycoming County from January 31 to February 2, 2021.
A winter storm produced 9 to 18 inches of snow across Northumberland County from January 31 to February 2, 2021.
A winter storm produced 11 to 18 inches of snow across Perry County from January 31 to February 2, 2021.
A winter storm produced 14 to 21 inches of snow across Schuylkill County from January 31 to February 2, 2021.
A winter storm produced 10 to 15 inches of snow across Snyder County from January 31 to February 2, 2021.
A winter storm produced 8 to 17 inches of snow across Somerset County from January 31 to February 2, 2021.
A winter storm produced 10 to 15 inches of snow across southern Centre County from January 31 to February 2, 2021.
A winter storm produced 8 to 12 inches of snow across southern Clinton County from January 31 to February 2, 2021.
A winter storm produced 11 to 15 inches of snow across southern Lycoming County from January 31 to February 2, 2021.
A winter storm produced 11 to 14 inches of snow across Sullivan County from January 31 to February 2, 2021.
A winter storm produced 12 to 14 inches of snow across Tioga County from January 31 to February 2, 2021.
A winter storm produced 14 to 16 inches of snow across Union County from January 31 to February 2, 2021.
A winter storm produced 8 to 12 inches of snow across York County from January 31 to February 2, 2021.
A winter storm produced 10 to 15 inches of snow across Dauphin County from January 31 to February 2, 2021.
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, February 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: 942024, 942438, 942440, 942442, 942443, 942444, 942446, 942447, 942449, 942450, 942451, 942453, 942454, 942456, 942457, 942458, 942459, 942460, 942461, 942466, 942468, 942469, 942471, 942472, 942473, 942474, 942476, 942477, 942493.