EF0 tornado, Keno, Oregon, April 17, 2007

1. EF065 to 85 mphthis tornado

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. EF186 to 110 mph

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. EF2111 to 135 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. EF3136 to 165 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. EF4166 to 200 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. EF5over 200 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

EF0

Date

April 17, 2007

Touchdown

3:37 PM PDT (22:37 UTC)

Lifted

3:38 PM PDT (22:38 UTC)

On the ground

1 minutes

Path length

1.0 miles (1.6 km)

Path width

10 yards (9 m)

Deaths

0

Injuries

0

County

Klamath County

Touchdown point

42.130, -121.891

Lift-off point

42.130, -121.891

Record number

0704171637-01

NWS employees on a work-related trip photographed what was thought to be a funnel cloud 2 miles east of Keno on 04/17/07. When the photograph was perused after their return, a debris cloud was evident in the photo. There was no thunderstorm associated with this funnel, and no damage was reported.

Photographic evidence was analyzed after the fact, and it was determined that cold air funnels were in the image.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 19:23 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

NWS Medford, OR wrote its last area forecast discussion before the tornado touched down at Apr 17, 2:50 PM PDT, 47 minutes earlier.

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MEDFORD OR
250 PM PDT TUE APR 17 2007

.DISCUSSION...
THE COLD FRONT HAS CROSSED OUR REGION. FOLLOWING BEHIND TODAY IS
VERY COLD AIR AROUND -25C AT 500MB IN A DEEP TROUGH WHICH WILL
KEEP THE SHOWING GOING AND GENERATE SOME ISOLATED THUNDER ESPECIALLY
IN THE AFTERNOON.

TONIGHT AND WEDNESDAY A SHORT WAVE RIDGE BUILDS WITH A BRIEF BREAK IN
THE RAIN. WEDNESDAY AFTERNOON AND EVENING ANOTHER COLD FRONT BRINGS
ANOTHER ROUND OF RAIN. A CLOSED UPPER LOW SLIDES SOUTH ALONG THE
COAST THURSDAY THEN SOUTHEAST INTO CENTRAL CALIFORNIA THURSDAY
NIGHT.

FRIDAY A BIG BUT BRIEF RIDGE SQUELCHES THE RAIN HOWEVER SOON TOO
SOON PERHAPS SATURDAY ANOTHER COLD FRONT FOLLOWED BY A DEEP COLD
TROUGH SATURDAY NIGHT EXTENDS THE ROUND OF RAIN THROUGH SUNDAY.

SUNDAY NIGHT ANOTHER RIDGE IS QUICKLY REPLACE BY A COLD FRONT
MONDAY NIGHT.

&&

.AVIATION...GENERALLY VFR EXCEPT FOR MVFR IN SHOWERS TODAY.
SHOWERS DIMINISHING TONIGHT.

&&

.MFR WATCHES/WARNINGS/ADVISORIES...
OR...NONE.

CA...NONE.

PACIFIC COASTAL WATERS...SCA FOR HAZARDOUS SEAS.

05

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MEDFORD OR
157 PM PST TUE APR 17 2007

ORZ023>026-181600-
CENTRAL DOUGLAS COUNTY-EASTERN CURRY COUNTY AND JOSEPHINE COUNTY-
EASTERN DOUGLAS COUNTY FOOTHILLS-JACKSON COUNTY-
157 PM PST TUE APR 17 2007

THIS HAZARDOUS WEATHER OUTLOOK IS FOR SOUTHERN OREGON AND NORTHERN
CALIFORNIA

.DAY ONE...TODAY

A FROST ADVISORY IS IN EFFECT FROM 200 AM PDT THROUGH 800 AM PDT
WEDNESDAY. PLEASE SEE THE FROST ADVISORY FOR FURTHER DETAILS.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH TUESDAY

A FROST ADVISORY IS IN EFFECT FROM 200 AM PDT THROUGH 800 AM PDT
WEDNESDAY. PLEASE SEE THE FROST ADVISORY FOR FURTHER DETAILS.

.SPOTTER INFORMATION STATEMENT...

WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.

LS

In the hours before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
222 PM PDT TUE APR 17 2007

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0220 PM     LIGHTNING        30 SW ASHLAND           41.88N 123.11W
04/17/2007                   SISKIYOU           CA   PUBLIC

            SKI PATROL AT MT ASHLAND REPORTED HEARING THUNDER DURING
            A SNOW SHOWER. CLOUD TO GROUND LIGHTNING WAS OBSERVED
            THROUGH NLDN DATA.

&&

SMITH

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

The Medford radar (KMAX), 68 km away, was scanning. The volume nearest the touchdown began at 22:36 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

Local storm reports within 60 km of the path, in the three hours either side.

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

The live radar over the trackEvery 2007 tornado in OregonEvery tornado in Oregon since 1950Warnings in force in Oregon nowThe forecast where you are

7 more were confirmed in the United States that day.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.