Alert archive / Oklahoma / Tornado Watches in 2007

Tornado Watch 616

August 19, 200716 counties in Oklahoma

The Storm Prediction Center issued this tornado watch at Aug 19, 2007, 2:51 AM CDT for 16 counties in Oklahoma. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued
Aug 19, 2007, 2:51 AM CDT (07:51 UTC)
Expired
Aug 19, 2007, 8:00 AM CDT
In force
5 hr
Issued by
the Storm Prediction Center
Largest hail expected
0.5 in
Strongest gust expected
60 kt

Counties Blaine County, OK, Canadian County, OK, Cleveland County, OK, Comanche County, OK, Cotton County, OK, Garvin County, OK, Grady County, OK, Jefferson County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, McClain County, OK, Oklahoma County, OK, Payne County, OK, Pottawatomie County, OK, Stephens County, OK

The radar

The Norman radar (KTLX), 49 km from the middle of the area, began a volume at 07:55 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
40%
One or more EF2 to EF5 tornadoes
20%
Ten or more severe wind reports
40%
One or more gusts of 65 knots or more
30%
Ten or more severe hail reports
5%
One or more hailstones of 2 inches or more
5%
Six or more combined severe hail and wind reports
70%

Warnings issued inside it

9 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

IssuedProductOfficeCountiesLasted
Aug 19, 2:55 AM CDTSevere Thunderstorm WarningOUNBlaine50 min
Aug 19, 3:15 AM CDTSevere Thunderstorm WarningOUNCanadian, Cleveland, Grady, McClain, Oklahoma60 min
Aug 19, 3:19 AM CDTTornado WarningOUNGrady26 min
Aug 19, 3:46 AM CDTSevere Thunderstorm WarningOUNBlaine44 min
Aug 19, 3:53 AM CDTSevere Thunderstorm WarningOUNKingfisher52 min
Aug 19, 3:58 AM CDTSevere Thunderstorm WarningOUNStephens47 min
Aug 19, 4:29 AM CDTSevere Thunderstorm WarningOUNBlaine, Canadian, Kingfisher61 min
Aug 19, 4:55 AM CDTSevere Thunderstorm WarningOUNOklahoma50 min
Aug 19, 5:29 AM CDTSevere Thunderstorm WarningOUNCanadian, Kingfisher91 min

Discussions around it

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

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 7.9 hours before the alert went out and 40 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, Norman, OK at 00:00Z on 2007-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1581 joules per kilogram.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.
HodographHodograph, Norman, OK at 00:00Z on 2007-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 121 square meters per square second.193958Sfc1 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.
Mixed-layer CAPE
1581 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
650 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
121 m²/s²
0-3 km storm-relative helicity
200 m²/s²
Significant tornado parameter
0.8
Supercell composite
4.7

Open this sounding in Storm Lab

The text

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

000
WWUS20 KWNS 190749
SEL6  
SPC WW 190749
OKZ000-191300-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 616
NWS STORM PREDICTION CENTER NORMAN OK
250 AM CDT SUN AUG 19 2007

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

       CENTRAL OKLAHOMA

EFFECTIVE THIS SUNDAY MORNING FROM 250 AM UNTIL 800 AM CDT.

TORNADOES...HAIL TO 0.5 INCH IN DIAMETER...THUNDERSTORM WIND
GUSTS TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE
AREAS.

THE TORNADO WATCH AREA IS APPROXIMATELY ALONG AND 40 STATUTE
MILES EAST AND WEST OF A LINE FROM 50 MILES NORTH OF OKLAHOMA
CITY OKLAHOMA TO 50 MILES SOUTHEAST OF FORT SILL OKLAHOMA.  FOR A
COMPLETE DEPICTION OF THE WATCH SEE THE ASSOCIATED WATCH OUTLINE
UPDATE (WOUS64 KWNS WOU6).

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.

DISCUSSION...REMNANT CIRCULATION OF TD ERIN HAS RAPIDLY INTENSIFIED
OVER THE PAST FEW HOURS...WITH LOW LEVEL VERTICAL SHEAR PROFILES
BECOMING EXTREMELY STRONG ON LOCAL VAD/PROFILERS.  THUNDERSTORMS IN
ADVANCE OF CIRCULATION CENTER HAVE ALSO SHOWN MARKED INCREASES IN
ORGANIZATION WITH A FEW MESOCYCLONES NOW BEING INDICATED.  THREAT
FOR ISOLATED TORNADOES AND DAMAGING WINDS WILL PERSIST FOR THE NEXT
SEVERAL HOURS AND SPREAD SLOWLY EASTWARD ACROSS CENTRAL OK.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 0.5 INCH. EXTREME TURBULENCE AND SURFACE
WIND GUSTS TO 60 KNOTS. A FEW CUMULONIMBI WITH MAXIMUM TOPS TO
600. MEAN STORM MOTION VECTOR 24025.


...HART

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 18, 11:36 PM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Comanche, Custer, Grady and 3 more3 hr
Aug 19, 1:46 AM CDTMesoscale DiscussionSPCBlaine, Caddo, Canadian, Carter, Cleveland, Comanche and 15 more59 min
Aug 19, 7:27 AM CDTMesoscale DiscussionSPCCanadian, Carter, Cleveland, Garvin, Grady, Jefferson and 9 more63 min
Aug 19, 1:58 PM CDTMesoscale DiscussionSPCAdair, Cherokee, Craig, Delaware, Haskell, McIntosh and 7 more3 hr

Nearby

Tornado Watches in Oklahoma, 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.