Tornadoes · United States · Idaho · 2001
F0 tornado, Weiser, Idaho, September 13, 2001
This F0 tornado ran 1.0 miles across Washington County on September 13, 2001, touching down at 5:00 PM MDT and reaching 10 yards wide. It killed nobody.
The rating scale
Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.
F040 to 72 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
F173 to 112 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
F2113 to 157 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.
F3158 to 206 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
F4207 to 260 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
F5261 to 318 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.
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
- F0
- Date
- September 13, 2001
- Touchdown
- 5:00 PM MDT (23:00 UTC)
- Path length
- 1.0 miles (1.6 km)
- Path width
- 10 yards (9 m)
- Deaths
- 0
- Injuries
- 0
- County
- Washington County
- Touchdown point
- 44.250, -116.970
- Lift-off point
- 44.250, -116.970
- Record number
- 452
What the Weather Service recorded
A tornado touched down briefly and moved east, crossing US Highway 95 about 7 miles north of Weiser. A barn, shed and mobile home received some damage before the tornado lifted.
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 20:11 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.
What forecasters said that day
The local office's own words before the tornado touched down, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Boise, ID wrote its last area forecast discussion before the tornado touched down at Sep 13, 4:15 PM MDT, 45 minutes earlier.
Area forecast discussion, Sep 13, 4:15 PM MDT, 45 minutes before
SOUTHWEST IDAHO/SOUTHEAST OREGON AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE IDAHO 415 PM MDT THU SEP 13 2001 18Z RAOB SHOWED MODIFIED CAPE TO 1600 WHILE SCAN LOCAL CAPES SHOWS UP TO 2200 J/KG. LI -6. SATELLITE IN RSO SINCE 1PM SHOWING OVERSHOOTING TOPS IN VIS/IR WITH LOCAL REPORTS OF DIME HAIL NR ARROWROCK DAM AND OUTFLOW BOUNDARY THRU UPPER TREASURE VALLEY EARLY AFTN AND IN LOWER T.V. AT 415 PM. HEAVY RAIN REPORTS ALL OVER LAST NIGHT AND TODAY WITH ONE HOUR TOTALS TO 0.4 AND STORM TOTALS TO 0.8 AT HIGH ELEVATION RAWS. SHORTWAVE TROF WITH COMMAHEAD OVER TREASURE VALLEY TO CONTINUE MOVING NORTH AS UPPER LOW IN SOUTH CENTRAL OREGON, WITH LESS IMPRESSIVE RW/TRW, SHIFTS NE THROUGH THE CWFA. SOME CLOUDS LINGERING TONIGHT BUT JUST ISOLATED BY MIDNIGHT. LOTS OF MOISTURE FROM BRIEF HEAVY RAIN FOR SOME CLOUDS FRIDAY. SOME CLEARING FRIDAY NIGHT FOR COOLER NIGHT. WEAK SHORTWAVE SATURDAY AFTERNOON FOR SLIM CHANCE POPS. SUNDAY DRY. YESTERDAYS 12Z AVN AND ABOUT 3 RUNS AGO MRF COMING TOGETHER WITH A CHANCE OF RAIN MONDAY. DRYING AND WARMER TUESDAY THROUGH THURSDAY. .BOI...NONE.
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
11.0 hours before the tornado, 98 km from the path. September 13, 2001.
- Mixed-layer CAPE
- 161 J/kg
- Mixed-layer CIN
- -202 J/kg
- Surface CAPE
- 82 J/kg
- Mixed-layer LCL
- 1354 m above ground
- 0-6 km bulk shear
- 22 kt
- 0-1 km bulk shear
- 5 kt
- 0-1 km storm-relative helicity
- 18 m²/s²
- 0-3 km storm-relative helicity
- 31 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.7 K/km
Boise Airport, ID (KBOI), 00:00Z
1.0 hours after it, 98 km from the path. September 14, 2001.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -90502 J/kg
- Surface CAPE
- 135 J/kg
- Mixed-layer LCL
- 1594 m above ground
- 0-6 km bulk shear
- 11 kt
- 0-1 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- -95 m²/s²
- 0-3 km storm-relative helicity
- -69 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 5.2 K/km
The surface observations
Ontario Municipal (ONO), 26 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 21:53 UTC | 82 | 53 | 0° 0 kt | 1013.9 | ||
| 22:53 UTC | 82 | 52 | 150° 8 kt | 1013.5 | ||
| 23:53 UTC | 71 | 51 | 160° 17 kt | 23 | 1013.5 | |
| 00:14 UTC | 71.6 | 51.8 | 160° 16 kt | 20 | 1014.9 | VCTS |
| 00:31 UTC | 69.8 | 51.8 | 150° 11 kt | 17 | 1015.9 | |
| 00:53 UTC | 69 | 51 | 180° 5 kt | 1016.9 | VCTS |
From the Iowa Environmental Mesonet's archive of airport observations.
This ground now
The live radar over the trackEvery 2001 tornado in IdahoEvery tornado in Idaho since 1950Warnings in force in Idaho nowThe forecast where you are
The other tornadoes of September 13, 2001
2 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| September 13 | 4:30 AM CDT | F0 | Benton, MS | 5.0 | 50 | $10,000 | ||
| September 13 | 2:40 PM EDT | F0 | Nassau, FL | 0.1 | 5 | $1,000 |
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.