A major winter storm brought heavy snow to the region from the early morning through the late evening hours. Storm total snow accumulations ranged from six to twelve inches across the Laurel Highlands and south-central mountains.
Every event with a place to put it; 14 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 major winter storm brought heavy snow to the region from the early morning through the late evening hours. Storm total snow accumulations ranged from six to twelve inches across the Laurel Highlands and south-central mountains. The heaviest snow fell across portions of southeastern Pennsylvania where up to two feet of snow was observed.
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 Dec 18, 9:36 PM EST, 24 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 936 PM EST FRI DEC 18 2009 .SYNOPSIS... A STRONG STORM SYSTEM WILL MOVE UP THE EASTERN SEABOARD TONIGHT AND SATURDAY. THIS STORM WILL PRODUCE HEAVY SNOW FOR SOUTHEASTERN PENNSYLVANIA ON SATURDAY BEFORE MOVING OFF THE COAST. A PERSISTENT UPPER LOW NORTH OF PENNSYLVANIA SHOULD THEN KEEP THE REGION SEASONABLY COLD THROUGH THE MIDDLE OF NEXT WEEK. ANOTHER STORM IS POSSIBLE LATE NEXT WEEK...BUT MUCH UNCERTAINTY REMAINS AT THAT RANGE. && .NEAR TERM /UNTIL 6 AM SATURDAY MORNING/... SFC LOW...CURRENTLY ALONG THE S CAROLINA COAST...WILL INTENSIFY OVERNIGHT AS IT WORKS UP THE COAST...REACHING NR CAPE HATTERAS BY 12Z SAT. REGIONAL RADAR MOSAIC SHOWING PRECIP SHIELD APPROACHING THE MASON DIXON LINE ATTM AND LATEST MESOSCALE MODELS INDICATE SNOW WILL BREAK OUT OVER THE LAUREL HIGHLANDS AND SC MTNS BY MIDNIGHT...THEN SPREAD OVER THE REST OF SOUTHERN AND CENTRAL PA BY DAWN. FOR THE FIRST SEVERAL HRS SNOW SHOULD BE QUITE LIGHT DUE TO DRY ANTECEDENT CONDS AS EVIDENCED BY SATELLITE BLENDED PWAT IMAGERY. HOWEVER...RTS SHOULD PICK UP TOWARD DAWN AS ANOMALOUS EASTERLY LL JET/PWATS LIFT NORTH AND UPPER LVL DIV INCREASES IN ADVANCE OF UPPER LOW APPROACHING FROM THE OHIO VALLEY. WILL MOVE UP START TIME OF WARNINGS/ADVISORIES TO ARND MIDNIGHT BASED ON LATEST RADAR TRENDS. && .SHORT TERM /6 AM SATURDAY MORNING THROUGH SATURDAY NIGHT/... MAJOR WINTER STORM WILL IMPACT THE SRN/SERN PORTIONS OF OUR FCST/WARNING AREA THRU SAT EVENING. LATEST ENS MEAN QPF SUPPORTS 24HR WARNING CRITERIA SNOWFALL OF 8 INCHES OR MORE ACROSS THE SOUTHERN TIER COUNTIES WITH ADVISORY CRITERIA LIKELY TO BE MET AS FAR NORTH AS I-80. CENTER OF CIRCULATION LOOKS SIMILAR TO RUNS OF PREVIOUS DAYS...AND HAS LEAD TO INCREASING CONFIDENCE IN THE FORECAST. MAIN FACTORS IN THE DECISIONS ON THE WWA PRODUCTS WERE THE OVERWHELMINGLY GOOD AGREEMENT BETWEEN MOST MDLS AND ENSEMBLE MEMBERS AT THIS RANGE AND THE CLIMATOLOGICAL/HISTORICAL NORMS OF A STORM TRACK JUST EAST OF THE DELMARVA. LATEST SREF RUN KEEP HEAVIEST AMTS ALONG THE SRN BORDER AND MAINLY EAST OF BLUE MTN. EXPECT PORTIONS OF LANCASTER CO TO GET UP TO 12 INCHES OF SNOW BY LATE SAT NIGHT. MEANWHILE...THE N TIER LIKELY TO SEE ONLY ARND AN INCH. OROGRAPHIC ENHANCEMENTS THAT THE PEAKS IN SOMERSET CO AND THE HIGHER TERRAIN OF SCHUYLKILL CO SHOULD ADD TO THE TOTALS THERE...ESP IF PRECIP LINGERS LATE INTO SAT NIGHT IN THE POCONOS. THE SF AMOUNTS WE PAINTED WERE BASED ON SNOW-WATER EQUIVALENTS BETWEEN 10:1 AND 12:1 BECAUSE THE BEST UPLIFT IS DISPLACED TOO FAR UP IN THE COLUMN FOR DENDRITIC SNOW GROWTH. LATEST MODEL CROSS SECTIONS SHOW POTENTIAL OF INTENSE MESOSCALE BANDING /SLANTWISE CONVECTION/ DEVELOPING ON NW SIDE OF MID LVL LOW...AS IT TRACKS ACROSS THE DELMARVA SAT AFTN AND EVENING. 00Z NAM SHOWING A GOOD INSTABILITY SIGNATURE WITH LYR OF NEG EPV LOCATED JUST ABV 700MB FGEN. FOR NOW...ALL MODEL DATA SUGGESTING THIS MESOSCALE FEATURE AND ASSOCIATED ACCUMS WELL IN EXCESS OF A FOOT...SHOULD REMAIN JUST SE OF OUR CWA. HOWEVER...WILL HAVE TO BE WATCHED CLOSELY AS THIS SYSTEM DEVELOPS SAT. AS THE LOW PULLS AWAY SAT NIGHT...EXPECT PRECIP TO DWINDLE FASTEST IN THE CENTRAL MTS. SO...WILL END ADVSRYS/WARNINGS THERE JUST AFT MIDNIGHT SAT NIGHT. REST OF WWAS WILL RUN INTO SUN AM. BUT...THE BULK OF THE SF WILL BE DURING THE DAY SAT. && .LONG TERM /SUNDAY THROUGH FRIDAY/... PATTERN GETS EXTREMELY QUIET FOR SEVERAL DAYS BEGINNING ON SUNDAY...AFTER THE PRESENT MID ATLANTIC SNOW STORM DEPARTS LATE SATURDAY NIGHT. THE EARLY PORTION OF NEXT WEEK WILL HAVE PREDOMINANT NORTH TO NORTHWEST FLOW WITH THE TYPICAL LAKE CLOUDINESS AND SOME LIGHT SNOW SHOWER AND FLURRY ACTIVITY TO ACCOMPANY IT...ALONG WITH SLIGHTLY BELOW NORMAL TEMPERATURES. BY THE MIDDLE TO END OF THE WEEK...TEMPERATURES WILL MODERATE SLIGHTLY AHEAD OF A COMPLEX STORM SYSTEM WHICH MAY AFFECT THE REGION CHRISTMAS EVE INTO CHRISTMAS DAY. GIVEN THE TIME RANGE...AS WELL AS THE WIDE RANGE OF SOLUTIONS EVIDENT IN MEDIUM RANGE MODELS... HAVE OPTED TO BROADBRUSH MIXED PRECIPITATION CHANCES IN THE FORM OF RAIN OR SNOW FOR THIS TIMEFRAME. INTERNAL AND EXTERNAL CONSISTENCY HAS BEEN NON-EXISTENT IN MEDIUM RANGE MODELS HANDLING OF THE SITUATION BUT ALL AGREE TO SOME EXTENT OF ANOTHER PERIOD OF UNSETTLED AND POTENTIALLY WINTRY WEATHER FOR CHRISTMAS EVE AND DAY. && .AVIATION /03Z SATURDAY THROUGH WEDNESDAY/... WIDESPREAD VFR EXPECTED TO CONTINUE THROUGH JUST ABOUT THE ENTIRETY OF THIS EVENING IN ALL BUT EXTREME SOUTHERN TIER. TAFS REFLECT CONDITIONS SLOWLY FALLING TO MVFR/IFR FOR ALL AIRFIELDS LATE TONIGHT OR EARLY SAT FURTHER NORTH AS APRROACHING SNOWSTORM WILL BEGIN TO DROP CIGS AND VIS FOR ALL AIRFIELDS STARTING AT 04Z. SNOWFALL EXPECTED TO CONTINUE FOR MUCH OF THE DAY SATURDAY...KEEPING CIGS AND VIS IN THE MVFR CAT NORTH AND IFR SOUTH...WITH THE HEAVIEST SNOW OCCURING IN THE LOWER SUSQ /KMDT/ AND SOUTHWARD. WHITEOUT CONDITIONS LIKELY AT TIMES TOMORROW AFTERNOON AT KMDT IN HEAVIER SNOW BANDS. OUTLOOK... SAT NIGHT...IFR S/CENT. MVFR TO VFR NEAR THE NY BORDER. SUN...MVFR CIGS NW...MAINLY VFR ELSEWHERE. MON-TUE...MVFR/IFR NW IN SNOW SHOWERS...MVFR CENTRAL...VFR SE. WED...MAINLY VFR. && .CTP WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY FROM 2 AM SATURDAY TO 2 AM EST SUNDAY FOR PAZ017>019-024>028-049>053. WINTER STORM WARNING FROM 2 AM SATURDAY TO 7 AM EST SUNDAY FOR PAZ036-056>059-063>066. WINTER STORM WARNING UNTIL 2 AM EST SUNDAY FOR PAZ033>035. && SYNOPSIS...DANGELO NEAR TERM...FITZGERALD SHORT TERM...DANGELO/FITZGERALD LONG TERM...DEVOIR AVIATION...RXR
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 251 PM EST FRI DEC 18 2009 PAZ064>066-192000- ADAMS-YORK-LANCASTER- 251 PM EST FRI DEC 18 2009 ...WINTER STORM WARNING IN EFFECT FROM 4 AM SATURDAY TO 7 AM EST SUNDAY... 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...SATURDAY THROUGH THURSDAY. 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 REQUESTED TO REPORT SNOW ACCUMULATIONS TO THE NATIONAL WEATHER SERVICE IN STATE COLLEGE. PAZ036-056>059-063-192000- FRANKLIN-PERRY-DAUPHIN-SCHUYLKILL-LEBANON-CUMBERLAND- 251 PM EST FRI DEC 18 2009 ...WINTER STORM WARNING IN EFFECT FROM 4 AM SATURDAY TO 7 AM EST SUNDAY... 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...SATURDAY THROUGH THURSDAY. 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 REQUESTED TO REPORT SNOW ACCUMULATIONS TO THE NATIONAL WEATHER SERVICE IN STATE COLLEGE. PAZ033-192000- SOMERSET- 251 PM EST FRI DEC 18 2009 ...WINTER STORM WARNING IN EFFECT FROM 4 AM SATURDAY TO 2 AM EST SUNDAY... 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...SATURDAY THROUGH THURSDAY. 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 REQUESTED TO REPORT SNOW ACCUMULATIONS TO THE NATIONAL WEATHER SERVICE IN STATE COLLEGE. PAZ019-025>028-034-035-049>053-192000- SOUTHERN CENTRE-BLAIR-HUNTINGDON-MIFFLIN-JUNIATA-BEDFORD-FULTON- UNION-SNYDER-MONTOUR-NORTHUMBERLAND-COLUMBIA- 251 PM EST FRI DEC 18 2009 ...WINTER WEATHER ADVISORY IN EFFECT FROM 4 AM SATURDAY TO 2 AM EST SUNDAY... 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...SATURDAY THROUGH THURSDAY. 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 REQUESTED TO REPORT SNOW ACCUMULATIONS TO THE NATIONAL WEATHER SERVICE IN STATE COLLEGE. PAZ004>006-010>012-017-018-037-041-042-045-046-192000- WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD- NORTHERN CENTRE-TIOGA-NORTHERN LYCOMING-SULLIVAN-SOUTHERN CLINTON- SOUTHERN LYCOMING- 251 PM EST FRI DEC 18 2009 THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL PENNSYLVANIA. .DAY ONE...THIS AFTERNOON AND TONIGHT. NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...SATURDAY THROUGH THURSDAY. THE PROBABILITY FOR WIDESPREAD SEVERE WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE REQUESTED TO REPORT SNOW ACCUMULATIONS TO THE NATIONAL WEATHER SERVICE IN STATE COLLEGE. PAZ024-192000- CAMBRIA- 251 PM EST FRI DEC 18 2009 ...WINTER WEATHER ADVISORY IN EFFECT FROM 4 AM SATURDAY TO 2 AM EST SUNDAY... 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...SATURDAY THROUGH THURSDAY. 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 REQUESTED TO REPORT SNOW ACCUMULATIONS TO THE NATIONAL WEATHER SERVICE IN STATE COLLEGE. BEACHLER
The national radar mosaic for the moment the first event began.
14 winter storm. Local standard time, as filed.
Storm total snow accumulations ranged from eight to twelve inches.
Storm total snow accumulations ranged from eight to twelve inches.
Storm total snow accumulations ranged from eight to twelve inches.
Storm total snow accumulations ranged from ten to fifteen inches.
Storm total snow accumulations ranged from ten to fifteen inches.
Storm total snow accumulations ranged from twelve to twenty inches.
Storm total snow accumulations ranged from eight to twelve inches, mainly over the southern half of the county.
Storm total snow accumulations ranged from seven to eleven inches, mainly over the southern half of the county.
Storm total snow accumulations ranged from one to two feet.
Storm total snow accumulations ranged from one to two feet.
Storm total snow accumulations ranged from six to ten inches.
Storm total snow accumulations ranged from six to nine inches.
Storm total snow accumulations ranged from six to eight inches.
Storm total snow accumulations ranged from six to eight inches.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Pennsylvania in 2009Every state in 2009This day in weather historyWarnings in Pennsylvania, December 2009
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: 199836, 199837, 199838, 199840, 199841, 199842, 199930, 199932, 199844, 199845, 199846, 199847, 199848, 199849.