Tornadoes · United States · Texas · 2008
EF2 tornado, Denison Mckeon Arpt to Denison, Texas, December 8, 2008
From Denison Mckeon Arpt to Denison, this EF2 tornado ran 3.6 miles across Grayson County on December 8, 2008, touching down at 10:43 PM CST and reaching 125 yards wide. It killed nobody and injured 3, and did $750,000 of property damage.
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.
EF065 to 85 mph
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mphthis tornado
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.
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.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
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.
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
- EF2
- Date
- December 8, 2008
- Touchdown
- 10:43 PM CST (04:43 UTC)
- Lifted
- 10:48 PM CST (04:48 UTC)
- On the ground
- 5 minutes
- Path length
- 3.6 miles (5.8 km)
- Path width
- 125 yards (114 m)
- Deaths
- 0
- Injuries
- 3
- Property damage
- $750,000
- County
- Grayson County
- Touchdown point
- 33.715, -96.607
- Lift-off point
- 33.735, -96.548
- Record number
- 0812082243-01
What the Weather Service recorded
A dry line moved across north Texas as an upper level trough moved through the Desert Southwest. A line of thunderstorms developed and became severe as the night wore on. Two tornadoes and several downbursts caused significant damage across Grayson County. Strong winds followed behind a cold front and caused damage to power lines.
According to a damage survey conducted by the National Weather Service in Fort Worth, a lower EF-2 tornado affected areas of south and southwest Denison. Trees and power lines were downed. Dozens of homes, storage shelters, and businesses were damaged. About 500 homes in the area were without power.
From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.
The warnings
19 minutes of warning. NWS FWD issued a tornado warning for this county at 04:24 UTC, 19 minutes before the tornado touched down, in force until 05:00 UTC.
The county was under a severe thunderstorm watch, issued at 03:37 UTC and running to 09:00 UTC.
| Issued (UTC) | Expired | Product | Office |
|---|---|---|---|
| 14:00 UTC | 00:37 UTC | Wind Advisory | FWD |
| 03:37 UTC | 09:00 UTC | Severe Thunderstorm Watch | FWD |
| 04:13 UTC | 05:00 UTC | Severe Thunderstorm Warning | FWD |
| 04:24 UTC | 05:00 UTC | Tornado Warning | FWD |
| 18:00 UTC | 05:38 UTC | Wind Advisory | FWD |
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 Slight Risk, with a 0.02 chance of a tornado within 25 miles. The outlook in force was issued at 00:38 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.
Fort Worth, TX (KFWD), 00:00Z
4.7 hours before the tornado, 119 km from the path. December 9, 2008.
- Mixed-layer CAPE
- 259 J/kg
- Mixed-layer CIN
- -225 J/kg
- Surface CAPE
- 297 J/kg
- Mixed-layer LCL
- 1028 m above ground
- 0-6 km bulk shear
- 54 kt
- 0-1 km bulk shear
- 38 kt
- 0-1 km storm-relative helicity
- 307 m²/s²
- 0-3 km storm-relative helicity
- 336 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
- 0-3 km lapse rate
- 5.2 K/km
Fort Worth, TX (KFWD), 12:00Z
7.3 hours after it, 119 km from the path. December 9, 2008.
- Mixed-layer CAPE
- 0 J/kg
- Mixed-layer CIN
- -90034 J/kg
- Surface CAPE
- 0 J/kg
- Mixed-layer LCL
- 2636 m above ground
- 0-6 km bulk shear
- 49 kt
- 0-1 km bulk shear
- 23 kt
- 0-1 km storm-relative helicity
- -77 m²/s²
- 0-3 km storm-relative helicity
- 96 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
- 0-3 km lapse rate
- 4.8 K/km
The surface observations
Sherman/Denison (GYI), 9 km from the path, in the two hours either side.
| Time (UTC) | Temp (°F) | Dew point (°F) | Wind | Gust (kt) | Pressure (mb) | Weather |
|---|---|---|---|---|---|---|
| 03:05 UTC | 64.4 | 55.4 | 160° 17 kt | 1004.1 | ||
| 03:25 UTC | 64.4 | 55.4 | 150° 16 kt | 20 | 1002.7 | |
| 03:45 UTC | 64.4 | 57.2 | 150° 15 kt | 19 | 1002.7 | VCTS |
| 04:05 UTC | 62.6 | 57.2 | 150° 12 kt | 1003 | -VCTSRA | |
| 04:25 UTC | 62.6 | 59 | 150° 11 kt | 1003 | TSRA | |
| 04:45 UTC | 62.6 | 59 | 240° 8 kt | 27 | 1002.7 | +TSRA |
| 05:05 UTC | 62.6 | 59 | 200° 12 kt | 1003 | VCTS | |
| 05:25 UTC | 62.6 | 59 | 170° 9 kt | 1003 | TS | |
| 05:45 UTC | 62.6 | 59 | 180° 8 kt | 1002.7 | VCTS | |
| 06:05 UTC | 62.6 | 59 | 190° 7 kt | 1002.7 | ||
| 06:25 UTC | 62.6 | 59 | 200° 15 kt | 1002.7 | VCTS |
From the Iowa Environmental Mesonet's archive of airport observations.
The radar
The Dallas/Ft Worth radar (KFWS), 145 km away, was scanning. The volume nearest the touchdown began at 04:40 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.
What was reported nearby
Local storm reports within 60 km of the path, in the three hours either side.
| Time (UTC) | Report | Where | County | Remark |
|---|---|---|---|---|
| 04:26 UTC | TSTM WND DMG | 1 E Whitesboro | Grayson, TX | POWER POLES DOWN ACROSS FM 901 IN EASTERN WHITESBORO. |
| 05:06 UTC | TSTM WND DMG | 1 Se Collinsville | Grayson, TX | WIND DAMAGE 1 SE OF COLLINSVILLE GRAHAM GROVE RD HVY 902. BARN/SHOP DAMAGED MINOR PERSON INJURY POWER LINES DOWN. |
| 05:07 UTC | TSTM WND DMG | Denison | Grayson, TX | *** 1 INJ *** REGIONAL AND COUNTY EMS REPORT TREES AND POWERLINES DOWN IN DENISON. |
From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.
This ground now
The live radar over the trackEvery 2008 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are
The other tornadoes of December 8, 2008
2 more were confirmed in the United States that day.
| Date | Time | Rating | Where | Path (mi) | Width (yd) | Deaths | Injuries | Damage |
|---|---|---|---|---|---|---|---|---|
| December 8 | 10:22 PM CST | EF1 | Grayson, TX | 10.6 | 200 | 1 | $400,000 | |
| December 8 | 11:36 PM CST | EF1 | Wagoner, OK | 0.6 | 50 | $45,000 |
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.