A low pressure system moved over the area during a period of cold weather. The preceding cold temperatures were due high pressure that extended from Central Canada to just east of the Cascades.
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 PQR wrote it up.
A low pressure system moved over the area during a period of cold weather. The preceding cold temperatures were due high pressure that extended from Central Canada to just east of the Cascades. East winds ushered the very cold air through the Columbia River Gorge and throughout most of Northwest Oregon. Moisture from this low resulted in heavy snow for many parts of the Central and Southern Willamette Valley.
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 Portland, OR wrote its last area forecast discussion before the first event at Dec 5, 9:09 PM PST, 4 hours 51 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE PORTLAND OR
908 PM PST THU DEC 5 2013
.SYNOPSIS...A VERY COLD AIR MASS WILL REMAIN OVER THE FORECAST AREA
THROUGH EARLY NEXT WEEK. AN UPPER LEVEL DISTURBANCE DEVELOPING ALONG
THE WASHINGTON COAST TODAY WILL DIVE SOUTH ALONG THE OREGON COAST
TONIGHT AND FRIDAY MORNING...MOVING SOUTH OF THE FORECAST AREA FRIDAY
NIGHT. THIS SYSTEM WILL BRING AREAS OF SNOW TO THE OREGON COAST AND
INLAND AREAS MOSTLY SOUTH OF SALEM. THIS SYSTEM WILL ALSO BRING
STRONG AND GUSTY EAST WIND THROUGH THE GORGE AND INTO THE PORTLAND
AND VANCOUVER METRO AREA FRIDAY THROUGH FRIDAY NIGHT...WITH BITTER
WIND CHILLS. A SLOW MODERATION WILL OCCUR SUNDAY THROUGH EARLY NEXT
WEEK...FOLLOWED BY A TRANSITION TO MILDER AND WETTER CONDITIONS THE
LATTER HALF OF NEXT WEEK. THIS TRANSITION COULD START ICY FOR MANY
INLAND AREAS LATER TUESDAY INTO WEDNESDAY WITH COLD AIR IN PLACE.
&&
.EVENING UPDATE...MAIN CHANGE TO THE FORECAST PACKAGE THIS EVENING
WAS TO ISSUE A WIND ADVISORY FOR THE PORTLAND AND VANCOUVER METRO
AREA FRIDAY AND FRIDAY NIGHT. STRONG HIGH PRESSURE ASSOCIATED WITH A
BUILDING COLD POOL EAST OF THE CASCADES WILL COUPLE WITH THE LOW
OFFSHORE TO PRODUCE STRONG AND GUSTY EAST TO NORTHEAST WINDS
THROUGHOUT THE PDX/VUO METRO AREA. ALSO ASSISTING THIS WIND WILL BE
DOWNSLOPE ACCELERATION DUE TO THE DENSE COLD AIR FROM THE EAST SIDE
SPILLING WESTWARD OVER THE CASCADE CREST THROUGH THE BROADER GORGE
GAP BETWEEN MOUNT ADAMS AND MOUNT HOOD. SINCE THIS AIR WILL BE MORE
DENSE THAN ITS ENVIRONMENT...IT WILL TEND TO SINK AND ACCELERATE DOWN
THE WEST SLOPES OF THE CASCADES...SURFACING ACROSS PORTIONS OF THE
METRO AREA. THIS EFFECT SHOWS UP NICELY ON NAM CROSS-SECTIONS WITH A
STRONG DOWNWARD OMEGA FIELD TO THE LEE OF THE CASCADES.
OTHER CHANGES INCLUDE THE MENTION OF OCCASIONAL FLURRIES ACROSS OUR
NORTHERN AND EASTERN ZONES...AS THE 00Z GFS INSISTS THERE MAY BE A
LITTLE DEFORMATION PRECIPITATION TO THE NORTHEAST OF THE LOW AS IT
MOVES ONSHORE. THIS WILL NEED TO BE WATCHED VERY CLOSELY...IF A
DEFORMATION BAND DEVELOPS THERE COULD BE ACCUMULATING SNOW ACROSS AT
LEAST THE SOUTHERN SUBURBS OF PORTLAND. NAM CROSS-SECTIONS SHOW A
DECENT FRONTOGENESIS BAND SETTING UP NEAR PORTLAND ALONG WITH DECENT
Q-VECTOR CONVERGENCE AROUND 15Z FRI...BUT NO QPF LIKELY DUE TO THE
DRYING EAST WINDS. IT WILL BE A VERY CLOSE CALL...AND MODEL QPF OFTEN
DOES NOT HANDLE THIS SITUATION VERY WELL. ODDS ARE AGAINST
ACCUMULATING SNOW FOR PORTLAND...BUT CHANCES INCREASE RAPIDLY THE
FARTHER SOUTH ONE TRAVELS ON INTERSTATE 5.
ALSO WENT A FEW DEGREES COLDER FOR THE SOUTHERN HALF OF OUR CWA SAT
NIGHT...AS FRESH SNOW COVER...LIGHT WINDS AND CLEAR SKIES RESULT IN
OPTIMAL RADIATIONAL COOLING CONDITIONS. WILL NOT BE SURPRISED TO SEE
A COUPLE SHELTERED LOWLAND SPOTS GET BELOW ZERO IF ALL THIS COMES
TOGETHER RIGHT. OUR COLDEST FORECAST LOW FOR EUGENE AIRPORT IS NOW 4
DEGREES ABOVE ZERO...THOUGH THE CITY WOULD PROBABLY BE A FEW DEGREES
WARMER THAN THAT. REMAINDER OF SHORT TERM DISCUSSION BELOW IS STILL
VALID.WEAGLE
.SHORT TERM...THE LOW MOVES SOUTH OF OUR FORECAST AREA FRIDAY NIGHT
INTO EARLY SATURDAY WITH DRYING AND DECREASING SNOW. HOWEVER...THE
REINFORCING SHOT OF COLD AIR AND OFFSHORE WINDS BEHIND THIS SYSTEM
WILL KEEP IT VERY COLD AGAIN OVER THE WEEKEND. THE INCREASING
OFFSHORE GRADIENTS FRIDAY NIGHT AND SAT WILL RESULT IN EXTREMELY COLD
WIND CHILLS IN EAST WIND PRONE AREAS. SATURDAY HIGHS WILL STRUGGLE TO
GET OUT OF THE 20S FOR MANY INLAND AREAS.
IT APPEARS A SLOW MODERATION BEGINS SUNDAY...WITH 850 MB TEMPS IN THE
-7 TO -10C RANGE. IT WILL STILL BE COLD THOUGH. THERE IS A WEAK
DISTURBANCE THAT PASSES SOUTHWARD BUT WELL OFF THE COAST SUNDAY THAT
MAY GIVE US SOME CLOUDS BUT IT LOOKS DRY FOR NOW...MORE LIKE THE GFS
AND ECMWF THAN THE NAM12 MODEL. IT MAY TAKE UNTIL LATER NEXT WEEK TO
GET OUT OF THE COLD AIR ENTIRELY. TOLLESON
.LONG TERM...SUNDAY NIGHT THROUGH THURSDAY. FORECAST MODELS INDICATE
THAT THE COLD ARCTIC AIR MASS WILL REMAIN IN PLACE OVER THE REGION
THROUGH EARLY NEXT WEEK. 12Z ECMWF/GFS DEPICT AN AREA OF LIGHT
PRECIPITATION LATE MON INTO EARLY TUE ASSOCIATED WITH A WEAK IMPULSE
DROPPING SOUTH ALONG THE WEST COAST. GIVEN THE STRENGTH OF THE COLD
AIR FIRMLY IN PLACE...THIS COULD BRING SOME FREEZING RAIN...SNOW...
RAIN...OR SOME MIX OF THE ABOVE. CONFIDENCE IS SOMEWHAT LOW AND
AMOUNTS LOOK TO BE FAIRLY SMALL AT THIS TIME...SO KEPT POPS IN CHANCE
NORTH TO SLIGHT CHANCE SOUTH RANGES.
THE NEXT SYSTEM LOOKS TO MOVE INTO THE AREA FOR WED OR THU WITH SOME
MORE SIGNIFICANT MOISTURE CONTENT. AS THIS MOIST AND MILD SYSTEM
APPROACHES THE PACIFIC NORTHWEST...SOME HEAVY RAINFALL LOOKS POSSIBLE
AS WELL AS SOME MODERATING TEMPERATURES BACK CLOSER TO /BUT STILL
BELOW/ SEASONAL NORMS. GIVEN THE LOWER LEVEL COLD AIR IN PLACE...THIS
MAY BEGIN AS FREEZING RAIN OR ICE FOR SOME LOCATIONS. THIS IS
ESPECIALLY TRUE FOR AREAS IN THE COLUMBIA RIVER GORGE AND VALLEYS IN
THE CASCADE FOOTHILLS. HOWEVER...THE PARTICULAR TRACK OF THE
DEVELOPING LOW AND TIMING DIFFERENCES REMAIN TO BE SORTED OUT BETWEEN
THE FORECAST MODELS...AND THESE FACTORS WILL INFLUENCE WHERE SNOW
LEVELS MAY BE ALONG WITH THE POTENTIAL FOR MIXED FROZEN PRECIP VERSUS
JUST RAIN FOR LOWLAND LOCATIONS. CULLEN
&&
.AVIATION...LOW PRES OFF THE WASHINGTON COAST. CLOUDS WILL
CONTINUE TO THICKEN ACROSS REGION THROUGH 10Z. LIGHT SNOW ON COAST
AROUND OR SOON AFTER 06Z...SPREADING TO EAST AND SOUTH OVERNIGHT.
STILL EXPECT ACCUMULATIONS AT AIRPORTS TO S OF A KTMK TO KSLE
LINE...WITH OVER 1 INCH AT AIRPORTS S OF A KONP TO KS12 LINE.
LIKELY MVFR WITH THE SNOW WITH OCCASIONAL IFR ALONG THE COAST AND
INTO KEUG. SHOULD REMAIN VFR AS MOVE N AND E TOWARDS KPDX AND
KTTD. EAST WINDS WILL INCREASE IN THE MORNING AROUND KPDX AND
KTTD...WITH INCREASING E TO NE WINDS SPREADING W TO COAST BY
AFTERNOON.
KPDX AND APPROACHES...OFFSHORE FLOW SHOULD PRODUCE VFR CONDITIONS
AT THE TERMINAL THROUGH 00Z SATURDAY. WILL HAVE OCCASIONAL SNOW
FLURRIES BETWEEN 12Z AND 20Z...BUT NO ACCUMULATION EXPECTED. MAIN
WEATHER WILL BE INCREASING E WINDS AFTER 18Z. ROCKEY.
&&
.MARINE...NOT MUCH CHANGE. GUSTY E TO NE WINDS DEVELOP LATER
TONIGHT...AND CONTINUE THROUGH FRI NIGHT. WILL EXPAND SMALL CRAFT
ADVISORY FOR ALL COASTAL WATERS. SEAS REMAIN AT 2 TO 4 FT.
BENIGN WEATHER FOR SATURDAY THROUGH TUE. THEN STRONGER LOW
PRESSURE WILL MOVE INTO THE REGION...WITH INCREASING POTENTIAL FOR
SOUTHERLY GALES. ROCKEY.
&&
.PQR WATCHES/WARNINGS/ADVISORIES...
OR...WINTER WEATHER ADVISORY FROM 2 AM TO 4 PM PST FRIDAY FOR CASCADE
FOOTHILLS IN LANE COUNTY-CENTRAL COAST RANGE OF WESTERN
OREGON-CENTRAL WILLAMETTE VALLEY-NORTHERN OREGON CASCADE
FOOTHILLS.
WIND ADVISORY FROM 8 AM FRIDAY TO 6 AM PST SATURDAY FOR GREATER
PORTLAND METRO AREA.
WINTER STORM WARNING FROM 1 AM TO 4 PM PST FRIDAY FOR CENTRAL
OREGON COAST.
WINTER STORM WARNING FROM 2 AM TO 4 PM PST FRIDAY FOR SOUTH
WILLAMETTE VALLEY.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO 2 PM PST FRIDAY
FOR COAST RANGE OF NORTHWEST OREGON-NORTH OREGON COAST.
WA...WIND ADVISORY FROM 8 AM FRIDAY TO 6 AM PST SATURDAY FOR GREATER
VANCOUVER AREA.
WINTER WEATHER ADVISORY UNTIL 10 AM PST FRIDAY FOR SOUTH
WASHINGTON COAST.
PZ...SMALL CRAFT ADVISORY FOR WINDS LATE TONIGHT THROUGH FRI
NIGHT ON ALL COASTAL WATERS.
&&
MORE WEATHER INFORMATION ONLINE AT..
HTTP://WEATHER.GOV/PORTLAND
INTERACT WITH US VIA SOCIAL MEDIA
WWW.FACEBOOK.COM/US.NATIONALWEATHERSERVICE.PORTLAND.GOV
WWW.TWITTER.COM/NWSPORTLAND
THIS DISCUSSION IS FOR NORTHWEST OREGON AND SOUTHWEST WASHINGTON FROM
THE CASCADE CREST TO 60 NAUTICAL MILES OFFSHORE. THE AREA IS COMMONLY
REFERRED TO AS THE FORECAST AREA.2 heavy snow. Local standard time, as filed.
NWS Spotters, local media, Emergency Managers, and the general public reported 6 to 9 inches of snow in the Central Willamette Valley. Snow totals of 6 to 9 inches were reported in Veneta, Lorane, Philomath, Creswell, and Swisshome.
NWS Spotters, Emergency Managers, the media and the general public reported 4 to 9 inches of snow in the South Willamette Valley. The highest amounts of 8 to 9 inches were measured in Corvallis, Philomath, and Creswell.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2013Every state in 2013This day in weather historyWarnings in Oregon, December 2013
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: 490023, 490022.