Gusty west winds and low temperatures combined to produce very low wind chills across the region.
Every event with a place to put it; 23 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.
Gusty west winds and low temperatures combined to produce very low wind chills across the region.
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 Feb 4, 7:29 PM EST, 5 hours 31 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE STATE COLLEGE PA 729 PM EST SUN FEB 4 2007 .SHORT TERM /REST OF TONIGHT THROUGH MONDAY/... MAIN CHANGE WILL BE TO POST A WIND CHILL WARNING /MEANING -25F OR COLDER WCI/S/ FOR THE N&W. WIND CHILLS ALREADY DOWN TO -20F AT KBFD AND KDUJ AND -22F AT KJHW. SINCE WE ONLY NEED TO DROP 4-5F MORE...AND THESE HIGHER-ELEVATIONS WILL STAY WINDY ALL NIGHT...FEEL A WIND CHILL WARNING IS WARRANTED FOR MY N/W HALF FOR TONIGHT AND EARLY MONDAY...AND WILL CONTINUE THE ADVISORY THRU TUES AM FOR THE SAME AREA. MAY NEED ANOTHER WARNING FOR THE LAURELS AGAIN TUES AM...BUT WILL NOT GO WITH THAT JUST YET. WILL CONTINUE THE ADVISORY FOR THE REST OF THE LAND FOR OVERNIGHT/EARLY MONDAY. BIG LAKE BAND /WHICH SEEMED LIKE TWO BANDS OVER THE LAKE THAT MERGED AS THEY CAME TO THE SHORELINE NEAR KBUF/KDKK/ WILL SINK SLOWLY SWRD OVER THE NEXT FEW HRS...BUT ALSO BREAK INTO A MORE MULTI-BAND LOOK AS IT DOES SO. THIS SHEAR COMBINED WITH THE ULTRA-DRY AIRMASS WILL MEAN THAT THE SNOWS WILL NOT GET VERY FAR INLAND...AND THIS ALREADY PAINTED IN THE GRIDS. WILL GO FOR AN INCH OR TWO IN WARREN AND MCKEAN COS. && .PREV DISCUSSION... /ISSUED 332 PM EST SUN FEB 4 2007/ SHORT TERM /TONIGHT THROUGH MONDAY NIGHT/... BITTER COLD TEMPERATURES WILL CONTINUE THROUGH THE PERIOD. WIND CHILL ADVISORIES HAVE BEEN POSTED AND NO CHANGES TO THEM AT THIS TIME...ALTHOUGH IF WINDS STAY UP WE WILL TICKLE THE WARNING THRESHOLD OF -25F OVERNIGHT. WITH IT BEING SO MARGINAL WILL STAY WITH ADVISORY RIGHT NOW. OTHERWISE...NEXT TROUGH WILL BRING ADDITIONAL COLD AIR INTO THE REGION. IT WILL ALSO SUBTLY TURN FLOW FROM THE WEST TO THE NW AND BRING SOME SNOW SHOWERS INTO FAR NW PA TONIGHT INTO MONDAY. HIGHEST ACCUMS WILL BE CONTAINED TO EXTREME NW WARREN CO. ELSEWHERE...SOME SCATTERED SNOW SHOWERS WILL BE POSSIBLE IN THE LAUREL HIGHLANDS AS MOISTURE PICKED UP OVER THE WESTERN GREAT LAKES WILL BE TRANSPORTED INTO W PA AND WRUNG OUT AS IT GLIDES OVER THE MOUNTAINS. ELSEWHERE JUST SOME FLURRIES WILL BE POSSIBLE TONIGHT AND MON. MON NIGHT WILL BE QUIETER AS TROUGH LIFTS TO THE NE AND SURFACE HIGH PRESSURE NOSES IN. LONG TERM /TUESDAY THROUGH SUNDAY/... THE MAIN FCAST ISSUE IN THE LONG TERM WILL BE TIMING/STRENGTH/TRACK OF A FAST-MOVG CLIPPER SYSTEM FCAST TO TRANSLATE ESWED FROM THE NRN ROCKIES AND INTO THE MID ATLANTIC STATES BY LATE TUE->WED. HPC HAS NOTED THE NAM AS AN OUTLIER WITH THIS SYS DUE TO ITS VERY LOW SFC SOLN...WHICH HAS NO SUPPORT FROM OTHER OPERATIONAL MODELS OR THE PREFERRED 09Z SREF MEAN. ALONG WITH SURROUNDING OFFICES HAVE INC POPS ACROSS THE SRN 2/3 OF THE CWA...BUT WILL HOLD THEM IN THE CHC/SCHC CAT FOR NOW AS THERE IS STILL SOME UNCERTAINTY WRT TO THE DETAILS. A SECOND...WEAKER CLIPPER SYS PREVIOUSLY ADVERTISED TO COME THRU SOMETIME THUR/FRI NOW APPEARS TO STAY FURTHER SOUTH WITH LITTLE IMPACT ON OUR AREA. OVERALL...HAVE MAINLY FOLLOWED HPC GUID IN THE LATER PDS. THE VERY COLD AIR WILL RELINQUISH ITS GRIP ON CENTRAL PA IN THE MEDIUM RANGE AS THE CORE OF NEGATIVE HEIGHT ANOMALIES GRADUALLY WEAKENS AND MOVES NEWD BY LATE IN THE WEEK. THE COLDEST AIR AT 850MB BEGINS TO MODERATE BY WED-THUR ALTHOUGH STILL REMAINS SLIGHTLY BLW NORMAL /-1STD/ FOR THIS TIME OF YEAR. AS A RESULT...TEMPERATURES WILL REMAIN BLW NORMAL ALTHOUGH JUST NOT QUITE AS FRIGID AS EARLY IN THE WEEK. DESPITE THE SLIGHT MODERATION IN LLVL TEMPS...HI LATITUDE BLOCKING IN THE NRN STREAM OVR AK/NW CANADA APPEARS TO KEEP A NERN QUAD MEAN TROF IN PLACE ACROSS MUCH OF ERN CANADA/NERN CONUS INTO THE WEEKEND WITH PIECES OF S/W ENERGY ROTATING THRU THE NW FLOW...EFFECTIVELY ACTING TO REINFORCE THE CP/MODIFIED CA AIRMASS ALREADY IN PLACE. THIS SOLUTION HAS BROAD SUPPORT FROM THE OPERATIONAL MODELS AND THE 04/12Z GEFS/MREF. BOTTOM LINE...EXPECT TEMPERATURES TO REMAIN BLW NORMAL THRU MUCH OF THE LONG RANGE PD WITH SOME MODERATION PSBL TOWARD EARLY NEXT WEEK AS THE UPPER LEVEL PATTERN BEGINS TO DE- AMPLIFY. AVIATION /20Z-18Z/... COLD AIR FILTERING IN WILL TURN FLOW FROM WEST TO JUST SLIGHTLY NORTH OF WEST BY 00Z...NUDGING LAKE BANDS BACK SOUTHWARD TOWARD THE NY/PA BORDER AND SPREADING SOME SNOW SHOWERS BACK INTO KBFD. OTHERWISE JUST A CHANCE OF SOME LIGHT SNOW MAINLY AT KJST THAT WILL OCCASIONALLY REDUCE CIGS/VSBYS DOWN TO MVFR AS SOME MOISTURE FROM WESTERN GREAT LAKES IS TRANSPORTED INTO W PA. ELSEWHERE VFR CONDITIONS SHOULD PREVAIL THROUGH THE NEXT 24-36 HOURS WITH AN OCCASIONAL CIG OF 3KFT IN THE CENTRAL MOUNTAINS AFTER 00Z. && .CTP WATCHES/WARNINGS/ADVISORIES... WIND CHILL WARNING FROM 1 AM TO 11 AM EST MONDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042. WIND CHILL ADVISORY UNTIL 1 AM EST MONDAY FOR PAZ004>006- 010>012-017-018-024-033-037-041-042. WIND CHILL ADVISORY FROM 11 AM MONDAY TO 11 AM EST TUESDAY FOR PAZ004>006-010>012-017-018-024-033-037-041-042. WIND CHILL ADVISORY FROM 1 AM TO 11 AM EST MONDAY FOR PAZ019- 025>028-034>036-045-046-049>053-056>059-063>066. && SHORT TERM...DANGELO
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE STATE COLLEGE PA 825 PM EST SUN FEB 4 2007 PAZ004>006-010>012-017-018-024-033-037-041-042-060130- WARREN-MCKEAN-POTTER-ELK-CAMERON-NORTHERN CLINTON-CLEARFIELD- NORTHERN CENTRE-CAMBRIA-SOMERSET-TIOGA-NORTHERN LYCOMING-SULLIVAN- 825 PM EST SUN FEB 4 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT DANGEROUSLY COLD WIND CHILLS OF 25 TO 30 BELOW ZERO WILL OCCUR LATE TONIGHT AND EARLY MONDAY MORNING. THE CURRENT WIND CHILL ADVISORY WILL CHANGE TO A WIND CHILL WARNING FOR MOST OF THE OVERNIGHT. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY WIND CHILLS WILL REMAIN 10 TO 20 BELOW ZERO FOR MUCH OF THE DAY ON MONDAY AND INTO TUESDAY MORNING. THE WIND CHILL WARNING WILL CHANGE TO A WIND CHILL ADVISORY LATE MONDAY MORNING...AS THE WIND CHILLS REMAIN WELL BELOW ZERO FOR THE DAYLIGHT HOURS. HOWEVER...THE WIND CHILLS MAY AGAIN APPROACH MINUS 25 EARLY TUESDAY MORNING. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. PAZ019-025>028-034>036-045-046-049>053-056>059-063>066-060130- SOUTHERN CENTRE-BLAIR-HUNTINGDON-MIFFLIN-JUNIATA-BEDFORD-FULTON- FRANKLIN-SOUTHERN CLINTON-SOUTHERN LYCOMING-UNION-SNYDER-MONTOUR- NORTHUMBERLAND-COLUMBIA-PERRY-DAUPHIN-SCHUYLKILL-LEBANON- CUMBERLAND-ADAMS-YORK-LANCASTER- 825 PM EST SUN FEB 4 2007 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL PENNSYLVANIA. .DAY ONE...TONIGHT WIND CHILLS WILL REACH 15 TO 20 BELOW ZERO LATE TONIGHT AND EARLY MONDAY MORNING. A WIND CHILL ADVISORY IS IN EFFECT. .DAYS TWO THROUGH SEVEN...MONDAY THROUGH SATURDAY THE WIND CHILLS WILL BE 15 TO 20 BELOW ZERO MONDAY MORNING...BUT SHOULD RECOVER ABOVE 15 BELOW BY THE AFTERNOON...AND ALLOW THE WIND CHILL ADVISORY TO EXPIRE BEFORE NOON. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED. DANGELO
The national radar mosaic for the moment the first event began.
23 extreme cold/wind chill. Local standard time, as filed.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
Temperatures in the single digits, combined with west winds of 10 to 20 mph, produced wind chills of 10 to 15 degrees below zero.
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, February 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: 7507, 7508, 7509, 7510, 7511, 7512, 7513, 7514, 7515, 7516, 7517, 7518, 7519, 7520, 7521, 7522, 7523, 7524, 7525, 7526, 7527, 7528, 7529.