Alert archive / Oklahoma / Tornado Watches in 2007

Tornado Watch 84

March 28, 200720 counties in Oklahoma; 8 counties in Texas

The Storm Prediction Center issued this tornado watch at Mar 28, 2007, 4:54 PM CDT for 20 counties in Oklahoma; 8 counties in Texas. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Mar 28, 2007, 4:54 PM CDT (21:54 UTC)
Expired
Mar 28, 2007, 11:22 PM CDT
In force
6 hr
Issued by
the Storm Prediction Center
Largest hail expected
3 in
Strongest gust expected
60 kt
All 28 counties

Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Caddo County, OK, Comanche County, OK, Cotton County, OK, Custer County, OK, Dewey County, OK, Ellis County, OK, Greer County, OK, Harmon County, OK, Harper County, OK, Jackson County, OK, Kiowa County, OK, Major County, OK, Roger Mills County, OK, Tillman County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Archer County, TX, Baylor County, TX, Clay County, TX, Foard County, TX, Hardeman County, TX, Knox County, TX, Wichita County, TX, Wilbarger County, TX

The radar

The Altus AFB radar (KFDR), 138 km from the middle of the area, began a volume at 21:55 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What SPC expected

The probabilities SPC published with the watch, for the watch area over its life.

Two or more tornadoes
50%
One or more EF2 to EF5 tornadoes
30%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
60%
One or more hailstones of 2 inches or more
30%
Six or more combined severe hail and wind reports
80%

Discussions around it

SPC mesoscale discussions over the same counties from four hours before the watch to its end.

The nearest sounding before it

Fort Sill, OK (KFSI), launched 12:00Z, 9.9 hours before the alert went out and 127 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Fort Sill, OK at 12:00Z on 2007-03-28Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Sill, OK at 12:00Z on 2007-03-28The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 148 square meters per square second.193958Sfc1 km3 km6 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.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
1721 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
148 m²/s²
0-3 km storm-relative helicity
163 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000
WWUS20 KWNS 282154
SEL4  
SPC WW 282154
OKZ000-TXZ000-290500-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 84
NWS STORM PREDICTION CENTER NORMAN OK
455 PM CDT WED MAR 28 2007

THE NWS STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF 

       WESTERN OKLAHOMA
       PARTS OF NORTHWEST TEXAS

EFFECTIVE THIS WEDNESDAY AFTERNOON FROM 455 PM UNTIL MIDNIGHT CDT.

TORNADOES...HAIL TO 3 INCHES IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 60 STATUTE
MILES EAST AND WEST OF A LINE FROM 20 MILES NORTHWEST OF ALVA
OKLAHOMA TO 45 MILES SOUTHWEST OF WICHITA FALLS TEXAS.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU4).

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH
AREA. PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR
THREATENING WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS
AND POSSIBLE WARNINGS.

OTHER WATCH INFORMATION...CONTINUE...WW 80...WW 81...WW 82...WW
83...

DISCUSSION...STORMS ARE DEVELOPING RAPIDLY ACROSS TX PANHANDLE E OF
DRY LINE.  WITH AXIS OF VERY UNSTABLE AIR AND VERY FAVORABLE SHEAR
ENVIRONMENT ALONG WRN OK/TX BORDER...SUPERCELLS EXPECTED TO DEVELOP
NEWD ACROSS WATCH AREA THROUGH THE EVENING.  POTENTIAL FOR STRONG
TORNADOES ALONG WITH VERY LARGE HAIL WITH ANY SUPERCELL.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 3 INCHES. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
550. MEAN STORM MOTION VECTOR 22035.


...HALES

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 28, 3:14 PM CDTTornado Watch PDSSPCBeaver, Cimarron, Texas8 hr
Mar 28, 1:22 PM CDTMesoscale DiscussionSPCArmstrong, Borden, Briscoe, Carson, Castro, Collingsworth and 29 more83 min
Mar 28, 6:29 PM CDTMesoscale DiscussionSPCAndrews, Borden, Crane, Crockett, Dawson, Ector and 19 more3 hr

Nearby

Tornado Watches in Oklahoma, 2007Tornado Watches in Texas, 2007Every tornado watch in 2007

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.