Tornadoes · United States · Oregon · 2013

EF0 tornado, Lostine, Oregon, May 9, 2013

This EF0 tornado ran 0.1 miles across Wallowa County on May 9, 2013, touching down at 3:30 PM PDT and reaching 10 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  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.

The record

Rating
EF0
Date
May 9, 2013
Touchdown
3:30 PM PDT (22:30 UTC)
Lifted
3:35 PM PDT (22:35 UTC)
On the ground
5 minutes
Path length
0.1 miles (0.2 km)
Path width
10 yards (9 m)
Deaths
0
Injuries
0
County
Wallowa County
Touchdown point
45.521, -117.372
Lift-off point
45.521, -117.372
Record number
1305091630-01

What the Weather Service recorded

A very weak EF0 tornado briefly touched down 4 miles northeast of Lostine on Thursday May, 9th. The track was 0.1 miles and had a width of 10 yards.

COOP observer sent in pictures and a brief video of the short lived tornado.

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

The warnings

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 forecast that day

The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 20:01 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.

The air that afternoon

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.

Boise Airport, ID (KBOI), 12:00Z

10.5 hours before the tornado, 236 km from the path. May 9, 2013.

Skew-T log-pSkew-T log-p diagram, Boise Airport, ID at 12:00Z on 2013-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 0 joules per kilogram, CIN -89548, lifted condensation level 1940 meters above ground. Wind barbs in knots down the right edge.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Boise Airport, ID at 12:00Z on 2013-05-09The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 6 square meters per square second, 0 to 6 km bulk shear 14 knots.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
-89548 J/kg
Surface CAPE
0 J/kg
Mixed-layer LCL
1940 m above ground
0-6 km bulk shear
14 kt
0-1 km bulk shear
5 kt
0-1 km storm-relative helicity
6 m²/s²
0-3 km storm-relative helicity
45 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.3 K/km

Open this sounding in Storm Lab

Boise Airport, ID (KBOI), 00:00Z

1.5 hours after it, 236 km from the path. May 10, 2013.

Skew-T log-pSkew-T log-p diagram, Boise Airport, ID at 00:00Z on 2013-05-10Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 15 joules per kilogram, CIN -105, lifted condensation level 3107 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Boise Airport, ID at 00:00Z on 2013-05-10The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 11 square meters per square second, 0 to 6 km bulk shear 11 knots.1939Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
15 J/kg
Mixed-layer CIN
-105 J/kg
Surface CAPE
1149 J/kg
Mixed-layer LCL
3107 m above ground
0-6 km bulk shear
11 kt
0-1 km bulk shear
7 kt
0-1 km storm-relative helicity
11 m²/s²
0-3 km storm-relative helicity
70 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
9.8 K/km

Open this sounding in Storm Lab

The surface observations

La Grande (Awos) (LGD), 56 km from the path, in the two hours either side.

Time (UTC)Temp (°F)Dew point (°F)WindGust (kt)Pressure (mb)Weather
20:35 UTC82.442.8360° 8 kt141018.6
20:55 UTC82.4410° 0 kt1018.3
21:15 UTC84.239.210° 6 kt1018.3
21:35 UTC84.239.2340° 6 kt1018.3
21:55 UTC84.242.8360° 6 kt1017.9
22:15 UTC82.441350° 12 kt151017.6
22:35 UTC80.644.6330° 10 kt1017.6
22:55 UTC82.444.620° 9 kt1017.6
23:15 UTC82.446.420° 13 kt1017.6
23:35 UTC80.646.4360° 10 kt1017.6
23:55 UTC82.448.2360° 11 kt1017.6
00:15 UTC80.644.620° 8 kt1017.6

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Pendleton radar (KPDT), 117 km away, was scanning. The volume nearest the touchdown began at 22:31 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.

This ground now

The live radar over the trackEvery 2013 tornado in OregonEvery tornado in Oregon since 1950Warnings in force in Oregon nowThe forecast where you are

The other tornadoes of May 9, 2013

7 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
May 94:31 PM EDTEF0Norfolk, MA0.450$20,000
May 95:00 PM CDTEF0Kiowa, OK0.110
May 95:41 PM CDTEF0Christian, IL0.620
May 96:21 PM CDTEF0Jackson, OK0.120
May 98:14 PM EDTEF0Vigo, IN0.120$2,000
May 98:24 PM EDTEF0Vigo, IN0.120$2,000
May 911:35 PM CDTEF0Beauregard Parish, LA1.020$10,000

What this means

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.

Sources

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