A late season nor easter brought heavy snow to the higher elevations of north-central and western Pennsylvania on April 22-23, 2012. The snowfall generally ranged from 6 to 10 inches, with the heaviest snow recorded in Somerset County.
Every event with a place to put it; 11 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 late season nor easter brought heavy snow to the higher elevations of north-central and western Pennsylvania on April 22-23, 2012. The snowfall generally ranged from 6 to 10 inches, with the heaviest snow recorded in Somerset County. The Laurel Summit cooperative observer measured 23.7 inches of snow. The COOP site, which sits at an elevation of 2,770ft MSL, received 10 inches of snow Sunday night (4/22) and another 13.7 inches during Monday (4/23). Similarly, the nearby Seven Springs ski resort received a total of 18.5 inches of snow. Like many historic early and late season snow events, elevation was critical to snow accumulations. The snow turned to rain at lower elevations over the central ridge and valley areas, so little if any snow accumulated much below 1500 feet MSL.
With the initial bulk of the snow falling after dark on Sunday (4/22), the impacts were limited to travel disruptions, power outages, and tree damage in the northern mountains and Laurel Highlands. On Monday (4/23), numerous schools and local community services in affected counties had to cancel or modify operations as snow continued to accumulate over the higher terrain during the day.
Early on April 23rd, the Governor issued a Proclamation of Disaster Emergency for the state based on the projected impact the heavy, late season snow could bring forth. The PA National Guard mobilized 125 soldiers to assist in the state task force areas. At the height of the storm, there was a peak of 51,000 customers without power state-wide. The PennDOT districts in targeted areas activated Incident Command Centers and the Area Command. The PA Turnpike imposed speed restrictions Monday morning over the western higher terrain.
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 Apr 22, 7:47 PM EST, 1 hour 13 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 847 PM EDT SUN APR 22 2012 .SYNOPSIS... LOW PRESSURE WILL MOVE NORTHWARD ALONG THE ATLANTIC SEABOARD TONIGHT AND INTO PENNSYLVANIA ON MONDAY. THIS STORM WILL RAPIDLY INTENSIFY AS IT MOVES INTO THE LOCAL AREA...PULLING COLD AIR INTO WESTERN AND CENTRAL PENNSYLVANIA. HEAVY WET SNOW IS EXPECTED TO ACCUMULATE OVER THE WEST CENTRAL MOUNTAINS...LAUREL HIGHLANDS AND EVEN INTO THE HIGHER ELEVATIONS OF THE CENTRAL MOUNTAINS LATE TONIGHT THROUGH EARLY TUESDAY. THE HEAVIEST SNOW IS EXPECTED ON THE HIGHER ELEVATIONS. HEAVY WET ACCUMULATIONS OF SNOW WILL PRODUCE WIDESPREAD TREE DAMAGE AND LEAD TO POWER OUTAGES. IMPROVING BUT STILL UNSETTLED CONDITIONS WILL LAST INTO MID WEEK AS THE COLDEST AIR RETREATS NORTHWARD AND A FAST WESTERLY FLOW DEVELOPS. && .NEAR TERM /UNTIL MIDNIGHT TONIGHT/... RAIN ADVANCING TO THE NW ON SCHEDULE. LITTLE IF ANY CHANGES IN STORE TO THE FORECAST WITH THIS PACKAGE...BUT WATCHES WILL LIKELY BE REPLACED WITH WARNINGS AND PERHAPS ADVISORIES SOON. A BIT MORE COLLABORATION AND FINALIZATION OF SNOW AMOUNTS IS ON ORDER. THE SFC LOW IS CLOSE TO KHAT...AND ON COURSE FOR THE DELAWARE BAY OR SRN NJ BY MIDNIGHT. AS THE LOW GETS CLOSER...THE WINDS WILL BACK MORE AND THE 0C 8H ISOTHERM WILL PIVOT AROUND A CENTER POINT OVER THE ALLEGHENY FRONT BEFORE STARTING TO PUSH EASTWARD. COLD AIR DOES INTRUDE BELOW 8H THOUGH...AND PRECIP THAT REACHES THE WRN AND NRN MTS BEFORE MIDNIGHT WILL MIX WITH/TURN TO SNOW ON THE HIGHEST ELEVATIONS. THE RAINFALL IN THE EAST IS A MORE-IMMEDIATE CONCERN - BEFORE THE SNOW THAT IS - BUT QPF IS ON THE ORDER OF 1.5 TO AN EVEN 2 INCHES IN 12 HRS. THIS IS GOING TO BE HEAVY ENOUGH TO CAUSE VERY MINOR SMALL STREAM PROBLEMS ON SHARP RISES AND SOME URBAN/POOR-DRAINAGE FLOODING. BUT THESE WILL BE NUISANCE TROUBLES. THE RAIN WILL BE TAPERING OFF IN THE EAST AROUND MIDNIGHT OR SHORTLY AFTER. && .SHORT TERM /MIDNIGHT THROUGH 6 PM MONDAY/... KEEPIN IT SHORT AND SIMPLE. LOTS OF MOISTURE BEING SPUN BACK INTO THE AREA...BUT DRY AIR WILL ALSO BE INTRODUCED AS THE UPPER LOW MOVES INTO THE CENTRAL APPALACHIANS. 8H PWAT AND ERLY WIND ANOMALIES POINTED AT THE AREA FOR ONLY A SHORT 12 HR PERIOD TONIGHT...BUT THE LONG/CIRCUITOUS ROUTE FOR THE MOISTURE WILL ENSUE LATER TONIGHT AND LAST ALL MONDAY. WILL DROP POPS AND QPF OVER THE EASTERN HALF OF THE AREA FOR THE OVERNIGHT AND MONDAY DAY TIME WITH THE DRY AIR WORKING AROUND. THE TEMPS DO DROP STEADILY BUT ONLY SLIGHTLY OVER THE WESTERN HALF OF THE AREA OVERNIGHT AND INTO THE DAY. BUT THEY COULD RISE JUST A DEG OR TWO DURING THE DAY AS STRONG APRIL SUN WORKS THROUGH THE CLOUDS...ESP IN THE EAST. THE MOST LIKELY SCENARIO IS THAT HEAVY SNOW WILL START DURING THE NIGHT IN THE NRN AND SWRN HIGH ELEVATIONS FIRST...THEN WORK DOWN IN ELEVATION AND IN FROM THE WEST AS WELL. THIS COOLING WILL PROBABLY HALT AS THE SUN GETS HIGHER ON MONDAY...BUT A MIX OF RAIN AND SNOW IS STILL EXPECTED IN THE LOWER ELEVS OF THE RIDGE AND VALLEY REGION. THE SFC/BLYR TEMPS ARE THE TRICK TO THIS FCST - WITH THE SNOW ACCUMS ALMOST ENTIRELY ELEV DEPENDENT. THE TIMES OF HEAVY SNOW WILL BE TOUGH TO PINPOINT...AND WILL KEEP IT BROAD BRUSHED. WILL KEEP ON WITH THE GOING FCST AS THERE IS NO REASON TO CHANGE. TEMPS WILL HOVER IN THE LOWER AND MID 30S IN THE CENTRAL MTS...BUT 30-33 IN THE WRN AND NRN HIGHLANDS. THE ODDITY OF THIS FCST WILL BE THE RELATIVELY WARM AND DRY AIR THAT GETS INTO SULLIVAN AND TIOGA COS. ONLY MINOR TWEAKS TO THE SNOW ACCUMS ARE EXPECTED. && .LONG TERM /MONDAY NIGHT THROUGH SUNDAY/... DEEP TROUGH AND POWERFUL UPPER LOW WILL BE CENTERED OVER THE PA/NY BORDER MON NIGHT...WITH 500 MB HEIGHTS BELOW 530 FORECAST SOLIDLY BY THE ECMWF GFS AND NAM. LOW GRADUALLY LIFTS STRAIGHT NORTHWARD AS IT DEEPENS A BIT FURTHER THROUGH 12Z TUE...THEN BEGINS TO FILL IN ON TUE UPON ARIVING IN S CANADA. 987MB SFC LOW ALSO PUSHING NORTHWARD INTO S NY STATE MON NIGHT WILL FOCUS PRECIP ON ITS COLD SIDE AS 50+ KT COLD CONVEYOR BELT WRAPS AROUND FROM THE NW...WITH LITTLE PRECIP INDICATED FOR EASTERN HALF OF CWA. SO...ONGOING WINTER WEATHER EVENT ACROSS WESTERN HALF OF CWA WILL CONTINUE TO BE INTENSE HEADING INTO MON NIGHT...AND GRADUALLY LESSEN ITS GRIP AS NIGHT PROGRESSES AS COLD CONVEYOR BELT LIFTS NORTHWARD...RESULTING IN JUST A LIGHTER SNOW BY 12Z TUE - WHICH WILL LINGER IN THE NORTHERN MTNS POSS INTO WED. WINTER STORM WARNING/ADVISORY DURATION THROUGH MON NIGHT LOOKS JUSTIFIED BASED ON QPF FORECASTS/IMPACTS. STORM TOTAL SNOWFALL OVER MUCH OF THE ALLEGHENIES SHOULD EXCEED 8 INCHES...WITH SOME 12-16 INCH AMOUNTS PAINTED IN. SNOWFALL TAPERS OFF FAIRLY SHARPLY HEADING EAST ACROSS C MTNS...WITH A STRIPE OF 2 TO 4 INCHES IN THE CENTRAL MOUNTAINS - ACCUMULATING MAINLY ON THE GRASSY SURFACES WITH A LESSER IMPACT ON ROADS. LITTLE ACCUM EXPECTED IN SUSQ VALLEY...THOUGH SOME SNOW COULD MIX IN ON OCCASION WITH THE PREDOMINANT PRECIP TYPE OF RAIN - EVEN AS IT TAPERS TO SHOWERS MON NIGHT INTO TUES. THE DEEP UPPER TROF LIFTS TO THE NE WED-WED NIGHT...BUT NORTHWEST FLOW PERSISTS AS ADDITIONAL WEAKER DISTURBANCES ROTATE ACROSS THE REGION THROUGH THE REMAINDER OF THE WEEK...KEEPING WEATHER SOMEWHAT UNSETTLED INTO FRI BEFORE A DRIER REGIME MOVES IN. TEMPS LOOK TO BE BELOW NORMAL FOR MUCH OF THE WEEK. && .AVIATION /01Z MONDAY THROUGH FRIDAY/... STRENGTHENING LOW PRES MOVING UP THE E COAST WILL SPREAD RAIN AND INCREASINGLY GUSTY NNW WINDS ACROSS CENTRAL PA THIS EVENING. OVR THE HIGHER TERRAIN OF WESTERN PA...THE RAIN WILL CHANGE TO SNOW LATER THIS EVENING...ADDING LOW VSBYS TO THE ALREADY POOR FLYING CONDS. AT 00Z...BFD AND JST WERE THE ONLY CENTRAL PA AIRFIELDS REPORTING IFR CIGS. HOWEVER...DETERIORATING CIGS EXPECTED OVERNIGHT ACROSS THE CENTRAL MTNS...AS HEAVIER PRECIP OVERSPREADS THE AREA WITH IFR CIGS LIKELY AT BOTH UNV AND AOO. AFTER 06Z...EXPECT A DRY SLOT TO WORK INTO EASTERN PA...CAUSING THE RAIN TO TAPER OFF AT MDT AND LNS. HOWEVER...SNOW WILL CONTINUE TO FALL AT BFD/JST WITH LIFR VSBYS/CIGS QUITE POSSIBLE. ACROSS THE RIDGE/VALLEY REGION...AOO AND UNV WILL LIKELY BE ON THE DIVIDING LINE BTWN RAIN/SNOW LATE TONIGHT...BUT EITHER WAY...IFR CONDS APPEAR VERY LIKELY DUE TO LOW CIGS. AS THE STORM SYSTEM PASSES JUST TO OUR EAST...EXPECT GUSTY NW WINDS TO BUFFET THE AREA ON MONDAY...ESP OVR THE LAUREL HIGHLANDS WHERE BUFKIT SOUNDINGS SUPPORT GUSTS TO NR 30KTS AT JST. THE COLD...MOIST...UPSLOPING FLOW WILL PRODUCE SNOW AND LOW VSBYS/CIGS AT BFD/JST. SOMEWHAT BETTER CONDS LIKELY AT AOO/UNV...BUT OCNL SNOW COULD PRODUCE IFR VSBYS AT TIMES. MOST FAVORABLE CONDS WILL BE ACROSS THE SUSQ VALLEY...WHERE DRYING...DOWNSLOPING FLOW RESULT IN ONLY SCT -SHRA AND MVFR CIGS. OUTLOOK... TUE...LOW CIGS/VSBYS POSS AT BFD IN OCNL SHSN. WED...NO SIG WX EXPECTED. THU...RAIN/LOW CIGS POSS. FRI...NO SIG WX EXPECTED. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER STORM WARNING UNTIL NOON EDT TUESDAY FOR PAZ004>006- 010>012-017-018-024-033-037-041. WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 6 AM EDT TUESDAY FOR PAZ019-025-026-034-035-045. && SYNOPSIS...DANGELO NEAR TERM...DANGELO SHORT TERM...DANGELO LONG TERM...RXR AVIATION...FITZGERALD
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 554 PM EDT SUN APR 22 2012 PAZ004>006-010>012-017-018-024-033-037-041-232200- WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD- NORTHERN CENTRE-CAMBRIA-SOMERSET-TIOGA-NORTHERN LYCOMING- 554 PM EDT SUN APR 22 2012 ...WINTER STORM WARNING IN EFFECT FROM 10 PM THIS EVENING TO NOON EDT TUESDAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...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... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS AND SNOWFALL ACCORDING TO STANDARD OPERATING PROCEDURES. PAZ027-028-036-042-046-049>053-056>059-063>066-232200- MIFFLIN-JUNIATA-FRANKLIN-SULLIVAN-SOUTHERN LYCOMING-UNION-SNYDER- MONTOUR-NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON- CUMBERLAND-ADAMS-YORK-LANCASTER- 554 PM EDT SUN APR 22 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT. RAINFALL OF 1 TO 1.5 INCHES IS LIKELY OVERNIGHT. THIS WILL CAUSE MODERATE RISES ON SMALLER STREAMS...AND PONDING OF WATER IN LOW SPOTS...BUT NO FLOODING. THE RAIN COULD MIX WITH OR CHANGE TO WET SNOW OVERNIGHT ACROSS THE MOUNTAINS TO THE NORTH AND EAST OF WILLIAMSPORT...AND TO THE WEST OF MIDDLEBURG AND MIFFLINBURG. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY. PERIODS OF WET SNOW WILL FALL MONDAY INTO EARLY TUESDAY ON THE RIDGES SURROUNDING THE SUSQUEHANNA VALLEY WITH UP TO A FEW INCHES OF SLUSHY ACCUMULATION POSSIBLE...MAINLY EARLY MONDAY MORNING...AND AGAIN MONDAY NIGHT. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS AND SNOWFALL ACCORDING TO STANDARD OPERATING PROCEDURES. PAZ019-025-026-034-035-045-232200- SOUTHERN CENTRE-BLAIR-HUNTINGDON-BEDFORD-FULTON-SOUTHERN CLINTON- 554 PM EDT SUN APR 22 2012 ...WINTER WEATHER ADVISORY IN EFFECT FROM MIDNIGHT TONIGHT TO 6 AM EDT TUESDAY... THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...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... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS AND SNOWFALL ACCORDING TO STANDARD OPERATING PROCEDURES. LAMBERT
The national radar mosaic for the moment the first event began.
11 heavy snow. Local standard time, as filed.
Heavy snow amounts between 6 and 10 inches were generally observed across the county. The Laurel Summit COOP and Seven Springs Ski Resort received 18 to 24 inches.
Heavy snow amounts ranged between 6 and 10 inches over most of the county.
Heavy snow amounts ranged between 6 and 10 inches at elevations above 1500ft MSL.
Heavy snow amounts ranged between 6 and 10 inches at elevations above 1500ft MSL.
Heavy snow amounts ranged between 6 and 10 inches at elevations above 1500ft MSL.
Heavy snow amounts ranged between 6 and 10 inches at elevations above 1500ft MSL.
Heavy snow amounts ranged between 6 and 10 inches at elevations above 1500ft MSL.
Heavy snow amounts ranged between 6 and 10 inches at elevations above 1500ft MSL.
Heavy snow amounts ranged between 6 and 10 inches at elevations above 1500ft MSL.
Heavy snow amounts ranged between 6 and 10 inches at elevations above 1500ft MSL.
Heavy snow amounts ranged between 6 and 10 inches at elevations above 1500ft MSL.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2012Every state in 2012This day in weather historyWarnings in Pennsylvania, April 2012
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: 367460, 367461, 367462, 367463, 367464, 367465, 367466, 367467, 367468, 367469, 367470.