A fast moving Alberta Clipper brought 4 to 8 inches of snow to south central Pennsylvania.
Every event with a place to put it; 4 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 fast moving Alberta Clipper brought 4 to 8 inches of snow to south central Pennsylvania.
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 7, 12:57 AM EST, 1 hour 3 minutes earlier.
AREA FORECAST DISCUSSION...UPDATED NATIONAL WEATHER SERVICE STATE COLLEGE PA 1257 AM EST WED MAR 7 2007 .AVIATION /06Z-06Z/... LIGHT SNOW INVADING THE WESTERN SITES WITH IFR CONDS ATTM. LWR ATM STILL TOO DRY ACROSS THE CENTRAL TERMINALS...BUT SATURATION SHOULD OCCUR SHORTLY AND ANTICIPATE IFR -SN WITHIN THE NEXT FEW HOURS. EASTERN SITES WILL TAKE UNTIL AROUND 09Z OR SO. OVERALL...DETERIORATING CONDS /TO IFR/ WITH -SN OVERSPREADING LOCAL AIRFIELDS THROUGH LATE MORNING/EARLY AFTERNOON. BRIEF PERIODS OF LIFR ARE ALSO PSBL. SFC WNDS LGT AND VRB. && .PREV DISCUSSION... /ISSUED 1010 PM EST TUE MAR 6 2007/ SHORT TERM /REST OF TONIGHT THROUGH WEDNESDAY/... LITTLE OR NO CHANGE PLANNED TO THE PREVIOUS FCST...ESPECIALLY REGARDING SNOW AMOUNTS FROM THE UPCOMING CLIPPER. MID CLOUDS GRADUALLY LOWERING ACROSS THE WESTERN HALF OF PENN THIS EVENING...WITH THE LEADING EDGE OF LIGHT SNOW NEARING THE PA/OHIO BORDER AND EASTERN SHORE OF LAKE ERIE ATTM. 21Z SREF PLUME DIAGRAMS HAVE BEEN VERY CONSISTENT IN SHOWING MEAN QPF OF RANGING FROM AROUND ONE TENTH OF AN INCH ACROSS TIOGA COUNTY...TO 0.20-0.25 INCH OF LIQUID EQUIVALENT QPF ACROSS THE CENTRAL ZONES AND LOWER SUSQ VALLEY /FROM DUBOIS AND STATE COLLEGE AND HARRISBURG/...WITH UP TO 0.35 OF AN INCH ACROSS FAR SW ZONES. BASED ON A ROUGH 15...OR 18 TO 1 SNOW/WATER RATIO... 2 TO 4 INCHES STILL LOOKS ON TRACK FOR THE CENTRAL ZONES...WITH 3-6 INCHES FOR THE LAUREL HIGHLANDS. THE LIGHTEST AMOUNTS OF 1-3 INCHES WILL FALL FROM KIPT NORTH AND EAST. THE BULK OF THE SNOW WILL FALL FROM ROUGHLY 3 AM TO 10 AM ACROSS THE WEST...AND DAYBREAK THROUGH THE LATE MORNING HOURS OVER THE CENTRAL AND SE ZONES. PREV DISCUSSION... /ISSUED 335 PM EST TUE MAR 6 2007/ SHORT TERM /TONIGHT THROUGH WEDNESDAY/... AN ALBERTA CLIPPER DEVELOPING OVER THE NORTHERN PLAINS IS ALREADY SPREADING HIGH CLOUDINESS INTO THE GREAT LAKES AND OHIO VALLEY. MODELS HAVE BEEN CONSISTENT IN SLIDING AN AREA OF MAINLY LIGHT PRECIP ACROSS THE REGION FROM LATE NIGHT THROUGH ABOUT MID DAY WED. SREF PLUMES ARGUE FOR A GENERALIZED 2-4 INCH SNOWFALL WITH SLIGHTLY HIGHER AMOUNTS OVER MY FAR SOUTHWESTERN ZONES. THE ATMOS IS COLD AND FORECAST SOUNDINGS PLACE MUCH OF THE SATURATED PART OF THERMAL PROFILES IN THE -10 TO -20 C RANGE WHICH SHOULD ALLOW FOR DECENT SNOW GROWTH AND HIGHER THAN AVERAGE LIQUID TO SNOW RATIOS. WHAT DOES ARGUE AGAINST SETTLING ON VERY HIGH RATIOS IS THAT THE MODELS HAVE BEEN CONSISTENT IN GENERATING MOST OF THE LIFT ABOVE THE -20C LEVEL. OVERALL IT IS FCST TO BE A VERY FAST MOVING FLAT WAVE...WITH NO EASTERLY WIND ANOMALIES AT ALL. THESE TRADITIONALLY ARENT BIG SNOW PRODUCERS FOR THE REGION. SO CONSIDERING THE ABOVE...I SETTLED ON A MORE CONSERVATIVE APPROACH USING ABOUT 15-1 RATIOS OFF THE SREF PLUME FORECASTS. THIS YIELDS THE 2 TO ROUGHLY 5 INCH FORECAST AMOUNTS. SYSTEM WILL MOVE OUT LATER IN THE DAY WITH JUST SCATTERED SNOW SHOWERS LEFT OVER IN THE WEST AND NORTHWEST. WE WILL STAY BELOW NORMAL FOR TEMPS FOR A COUPLE OF MORE DAYS AT LEAST. LONG TERM /WEDNESDAY NIGHT THROUGH TUESDAY/... MEDIUM RANGE GUIDANCE CONTINUES TO ADVERTISE THE DEAMPLIFICATION OF THE UPPER RIDGE/TROF PATTERN CURRENTLY OVER NORTH AMERICA. THIS WILL LEAD TO A FAIRLY ZONAL UPPER FLOW PATTERN BY THE WEEKEND AND CONTINUE INTO NEXT WEEK. SFC HIGH PRESSURE WILL BE IN CONTROL THROUGH MUCH OF THE PERIOD AS THE WESTERN UPPER RIDGE BUILDS EAST AS IT WEAKENS. THIS WILL SUPPORT DRY WEATHER FROM WEDNESDAY NIGHT INTO SATURDAY WITH ONLY ISOLATED SNOW SHOWER ACTIVITY EXPECTED IN THE VICINITY OF LAKE ERIE FOLLOWING WEDNESDAYS CLIPPER PASSAGE. A TROF MOVING THROUGH THE NORTHERN STREAM CONTINUES TO BE FORECAST BY MEDIUM RANGE GUIDANCE TO BRING A FRONTAL SYSTEM THROUGH THE REGION ON SATURDAY. AFTER SEVERAL FAIRLY CONSISTENT RUNS OVER THE WEEKEND... LATEST RUNS SIGNIFICANTLY WEAKEN THIS FEATURE. SO WHILE A PERIOD OF RAIN AND/OR SNOW SHOWERS ARE EXPECTED ON SATURDAY...IT DOES NOT APPEAR TO BE A SIGNIFICANT PRECIPITATION EVENT. GUIDANCE ALSO SUGGESTS THAT THIS FRONT WILL STALL OVER PENNSYLVANIA AS UPPER FLOW WEAKENS AND SFC FLOW TURNS PARALLEL WITH THE FRONT. ACCORDINGLY WILL KEEP CHANCE OF RAIN SHOWERS OVER MOST OF THE REGION THROUGH TUESDAY WITH TEMPERATURES TRANSITIONING TO ABOVE NORMAL FOR THE LATTER HALF OF THE PERIOD. AVIATION /20Z-18Z/... PATCHY CLOUD COVER THAT KEPT JST MVFR MOST OF THE MORNING HAS FINALLY DISSIPATED. THE FORECAST FOR THE NEXT 12 HOURS OR SO IS PRETTY MUCH STRAIGHTFORWARD. CLEAR TO SCT SKIES GRADUALLY GIVING WAY TO INCREASING MID AND HIGH CLOUDINESS AHEAD OF THE NEXT FAST MOVING WEATHER SYSTEM. LIGHT SNOW SHOULD BEGIN IN THE WEST SHORTLY AFTER MIDNIGHT AND OVERSPREAD ALL TERMINALS BY DAYBREAK. IFR CONDITIONS WILL LIKELY DEVELOP QUICKLY WITH VIS DROPPING TO 1-3 MILES INITIALLY...AND WITHIN A COUPLE OF HOURS OF THE ONSET OF SNOW...DOWN TO A MILE OR LESS. THIS WILL CONTINUE FOR AN 8-12 HOUR PERIOD BEFORE IMPROVEMENT STARTS TO DEVELOP OUT OF THE NORTH IN THE AFTERNOON. FIRE WEATHER... DRY AIR MASS WITH SUSTAINED NORTHWEST WINDS GREATER THAN 15 MPH AND RELATIVE HUMIDITIES IN THE 20 PERCENT RANGE WILL PRESENT A MARGINAL FIRE WEATHER THREAT AREA OVER SOUTHEASTERN PARTS OF CENTRAL PENNSYLVANIA THIS AFTERNOON. HOWEVER WITH TEMPERATURES WILL BELOW FREEZING...THE GROUND AND MOST FINE FUELS REMAIN FROZEN...LIMITING SIGNIFICANT FIRE SPREAD POTENTIAL. IN COLLABORATION WITH PENNSYLVANIA BUREAU OF FORESTRY HAVE DECIDED TO HOLD OFF ON ANY RFW ISSUANCE FOR THIS AFTERNOON...BUT WILL CONTINUE TO MONITOR THE SITUATION. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 4 PM EST THIS AFTERNOON FOR PAZ017>019-024>028-033>036-049-050-052-056>059-063>066. && AVIATION...STEINBUGL
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 256 PM EST TUE MAR 6 2007 PAZ004>006-010>012-037-041-042-045-046-051-053-072000- WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-TIOGA- NORTHERN LYCOMING-SULLIVAN-SOUTHERN CLINTON-SOUTHERN LYCOMING- MONTOUR-COLUMBIA- 256 PM EST TUE MAR 6 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT AND WEDNESDAY LIGHT SNOW WILL OVERSPREAD THE REGION AFTER MIDNIGHT AND LAST INTO WEDNESDAY. 1 TO 3 INCHES OF SNOW IS EXPECTED. NO WARNINGS OR ADVISORIES ARE ANTICIPATED. .DAYS TWO THROUGH SEVEN...WEDNESDAY NIGHT THROUGH MONDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED. PLEASE REPORT SNOW AMOUNTS TO THE NATIONAL WEATHER SERVICE IN STATE COLLEGE BY USING THE INTERNET AT HTTP://NWS.MET.PSU.EDU/PUBREPORTS/LOGINSNOW.JSP (ALL IN LOWER CASE). PAZ017>019-024>028-033>036-049-050-052-056>059-063>066-072000- CLEARFIELD-NORTHERN CENTRE-SOUTHERN CENTRE-CAMBRIA-BLAIR- HUNTINGDON-MIFFLIN-JUNIATA-SOMERSET-BEDFORD-FULTON-FRANKLIN-UNION- SNYDER-NORTHUMBERLAND-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-CUMBERLAND- ADAMS-YORK-LANCASTER- 256 PM EST TUE MAR 6 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND TONIGHT A WINTER WEATHER ADVISORY FOR SNOW IS IN EFFECT FOR LATER TONIGHT THROUGH EARLY AFTERNOON WEDNESDAY. A FAST MOVING STORM SYSTEM WILL DROP BETWEEN 2 TO 5 INCHES OF SNOW BEFORE TAPERING TO SNOW SHOWERS AND FLURRIES WEDNESDAY AFTERNOON. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE NEEDED. PLEASE REPORT SNOW AMOUNTS TO THE NATIONAL WEATHER SERVICE IN STATE COLLEGE BY USING THE INTERNET AT HTTP://NWS.MET.PSU.EDU/PUBREPORTS/LOGINSNOW.JSP (ALL IN LOWER CASE). LA CORTE
The national radar mosaic for the moment the first event began.
4 heavy snow. Local standard time, as filed.
A fast moving storm system brought a brief period of snow to the Cambria County. While water equivalent values were low, the cold nature of the atmosphere resulted in very fluffy and rapid accumulating snow. In general, about 6 inches of snow accumulated across the county.
A fast moving storm system brought a brief period of snow to the Blair County. While water equivalent values were low, the cold nature of the atmosphere resulted in very fluffy and rapid accumulating snow. In general, 6 to 8 inches of snow accumulated across the county.
A fast moving storm system brought a brief period of snow to the Bedford County. While water equivalent values were low, the cold nature of the atmosphere resulted in very fluffy and rapid accumulating snow. In general, about 6 inches of snow accumulated across the county.
A fast moving storm system brought a brief period of snow to the Somerset County. While water equivalent values were low, the cold nature of the atmosphere resulted in very fluffy and rapid accumulating snow. In general, 6 to 9 inches of snow accumulated across the county.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2007Every state in 2007This day in weather historyWarnings in Pennsylvania, March 2007
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: 13132, 13136, 13138, 13141.