Most of the thunderstorms in this outbreak were not severe. However, one severe wind gust was recorded at Klamath Falls Airport.
Every event with a place to put it. 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 MFR wrote it up.
Most of the thunderstorms in this outbreak were not severe. However, one severe wind gust was recorded at Klamath Falls Airport.
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 Medford, OR wrote its last area forecast discussion before the first event at Sep 4, 2:12 PM PST, 4 hours 46 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MEDFORD OR 312 PM PDT SUN SEP 4 2011 .DISCUSSION...MAIN FORECAST ISSUES CONTINUE TO BE THE THUNDERSTORM POTENTIAL THIS EVENING THROUGH MONDAY AFTERNOON AND THE STRATUS ALONG THE COAST. SEE THE AVIATION DISCUSSION FOR EXPECTED CONDITIONS REGARDING THE MARINE LAYER. LATEST WATER VAPOR IMAGERY SHOWING AN UPPER LEVEL DISTURBANCE JUST OFF THE NORTHERN CALIFORNIA COAST WITH SOME MID TO UPPER LEVEL MOISTURE SWINGING NORTHWESTWARD INTO NORTHERN CALIFORNIA AND SOUTHERN OREGON. VISIBLE SHOWS SOME ACCAS CLOUDS ALSO LIFTING NORTHWARD INTO SISKIYOU AND MODOC COUNTIES WHICH IS INDICATIVE OF THE INSTABILITY ALOFT. AS THIS UPPER FEATURE MOVES TOWARD THE AREA THIS EVENING ISOLATED THUNDERSTORMS MAY DEVELOP IN THE VICINITY OF THE TRINITY ALPS AND THE MARBLE MOUNTAINS EAST-NORTHEASTWARD TO THE SOUTHERN CASCADES AND PORTIONS OF THE UPPER KLAMATH BASIN...WHERE MOISTURE...INSTABILITY AND FORCING ARE GREATEST. WE ARE NOT EXPECTING A WIDESPREAD THUNDERSTORM EVENT HERE...AND THE OVERALL PREDICTABILITY OF EXACTLY WHERE THUNDERSTORMS WILL DEVELOP REMAINS LOW...BUT THE BEST POTENTIAL FOR SOME ISOLATED LIGHTNING STRIKES EXISTS IN THOSE AREAS THROUGH THIS EVENING. THERE MAY BE A DECREASE IN ACTIVITY LATER THIS EVENING...BUT NOCTURNAL THUNDERSTORM POTENTIAL EXISTS FROM THE CASCADES EASTWARD AS THE UPPER TROUGH SWINGS IN OVERNIGHT. 500 MB TEMPS COOL TO ABOUT -13 TO -14C AS ANOTHER AREA OF ELEVATED INSTABILITY ARRIVES TOWARD DAWN OVER THE EAST SIDE. AS SUCH...WE MAINTAINED SLIGHT CHANCES FOR THUNDERSTORMS MAINLY FROM THE CASCADES EASTWARD. THE LATEST NAM12 AND GFS KEEP MOST OF THE UPPER LEVEL MOISTURE ALONG AND EAST OF THE CASCADES ON MONDAY...SO DID NOT MAKE ANY CHANGES TO THE OVERALL SLIGHT CHANCE AREA. WARMER AIR WILL MOVE IN ALOFT MONDAY NIGHT INTO TUESDAY AS THE TROUGH DEPARTS TO THE EAST AND THUNDERSTORM CHANCES WILL DIMINISH. A THERMAL TROUGH WILL SET UP ALONG THE COAST AGAIN AT MIDWEEK AND THIS WILL ALLOW INLAND AREAS TO HEAT UP. MODEL 850 TEMPS ARE STILL RUNNING ABOUT 25 TO 26C FOR WEDNESDAY IN MEDFORD AND THIS WILL BE OUR BEST SHOT AT 100 DEGREES ALL SUMMER. MODELS ARE INDICATING ANOTHER WEAK UPPER AIR DISTURBANCE POTENTIALLY BRINGING SOME MOISTURE NORTHWARD ON THURSDAY. CONFIDENCE IN THIS IS LOW...SO DID NOT MAKE ANY CHANGES AT THIS POINT...BUT FUTURE SHIFTS MAY NEED TO CONSIDER THUNDERSTORM POTENTIAL FOR THIS TIME FRAME. RIDGING TO THE NORTH MAY ALSO SUPPRESS THINGS FRIDAY...BUT THUNDERSTORMS ARE POSSIBLE AGAIN OVER THE WEEKEND...MAINLY OVER NORTHERN CALIFORNIA AND THE EAST SIDE. && .AVIATION...MARINE STRATUS WILL CONTINUE TO HUG THE COASTLINE TONIGHT INTO MONDAY MORNING WITH LIFR CEILINGS AND AREAS OF LIFR VISIBILITY DUE TO FOG. THE MARINE LAYER WILL RETREAT BACK OFFSHORE BRIEFLY FOR MOST AREAS MONDAY AFTERNOON...BUT MAY LAST ALL DAY ALONG THE SOUTH COAST...ESPECIALLY NEAR BROOKINGS. THE STRATUS WILL RETURN MONDAY EVENING. SOME HIGH BASED CUMULUS WILL MOVE ACROSS THE AREA THIS EVENING AND OVERNIGHT. ISOLATED THUNDERSTORMS ARE POSSIBLE OVER PORTIONS OF SISKIYOU COUNTY NORTHEASTWARD TO THE SOUTHERN CASCADES AND THE UPPER KLAMATH BASIN. && .MFR WATCHES/WARNINGS/ADVISORIES... OR...NONE. CA...NONE. PZ...NONE. SPILDE/DW/PETRUCELLI
The Medford radar (KMAX), 82 km away, was scanning. The volume nearest the first event began at 03:00 UTC.
1 thunderstorm wind. Local standard time, as filed.
Recorded at the Klamath Falls Airport ASOS.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2011Every state in 2011This day in weather historyWarnings in Oregon, September 2011
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: 334345.