Alert archive / Oklahoma / Severe Thunderstorm Watches in 2000

Severe Thunderstorm Watch 604

July 20, 200037 counties in Oklahoma

The Storm Prediction Center issued this severe thunderstorm watch at Jul 20, 2000, 11:45 PM CDT for 37 counties in Oklahoma. It was in force for 6 hr.

The area

The outline as issued.

The facts

Issued
Jul 20, 2000, 11:45 PM CDT (04:45 UTC)
Expired
Jul 21, 2000, 6:00 AM CDT
In force
6 hr
Issued by
the Storm Prediction Center
All 37 counties

Alfalfa County, OK, Blaine County, OK, Canadian County, OK, Cherokee County, OK, Craig County, OK, Creek County, OK, Custer County, OK, Delaware County, OK, Dewey County, OK, Ellis County, OK, Garfield County, OK, Grant County, OK, Harper County, OK, Kay County, OK, Kingfisher County, OK, Lincoln County, OK, Logan County, OK, Major County, OK, Mayes County, OK, Muskogee County, OK, Noble County, OK, Nowata County, OK, Okfuskee County, OK, Oklahoma County, OK, Okmulgee County, OK, Osage County, OK, Ottawa County, OK, Pawnee County, OK, Payne County, OK, Roger Mills County, OK, Rogers County, OK, Sequoyah County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK, Woods County, OK, Woodward County, OK

The radar

The Vance AFB radar (KVNX), 43 km from the middle of the area, began a volume at 04:46 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.

Warnings issued inside it

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

IssuedProductOfficeCountiesLasted
Jul 21, 12:02 AM CDTSevere Thunderstorm WarningOUNHarper, Woods, Woodward43 min
Jul 21, 12:02 AM CDTSevere Thunderstorm WarningOUNEllis43 min
Jul 21, 12:10 AM CDTSevere Thunderstorm WarningOUNGrant50 min
Jul 21, 12:32 AM CDTSevere Thunderstorm WarningOUNAlfalfa, Woods53 min
Jul 21, 12:50 AM CDTSevere Thunderstorm WarningOUNMajor, Woodward35 min
Jul 21, 1:24 AM CDTSevere Thunderstorm WarningOUNAlfalfa, Garfield, Grant51 min
Jul 21, 1:24 AM CDTSevere Thunderstorm WarningOUNMajor51 min
Jul 21, 1:48 AM CDTSevere Thunderstorm WarningOUNBlaine, Kingfisher42 min
Jul 21, 2:14 AM CDTSevere Thunderstorm WarningOUNGarfield, Grant, Kay, Noble46 min
Jul 21, 2:29 AM CDTSevere Thunderstorm WarningOUNCanadian, Kingfisher, Logan, Oklahoma61 min
Jul 21, 2:58 AM CDTSevere Thunderstorm WarningOUNNoble, Payne62 min
Jul 21, 2:58 AM CDTSevere Thunderstorm WarningOUNLincoln62 min
Jul 21, 3:43 AM CDTSevere Thunderstorm WarningTSACreek, Tulsa62 min

The nearest sounding before it

Norman, OK (KOUN), launched 00:00Z, 4.8 hours before the alert went out and 140 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 2000-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1499 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 2000-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 square meters per square second.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.
Mixed-layer CAPE
1499 J/kg
Mixed-layer CIN
-118 J/kg
Mixed-layer LCL
1859 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
140 m²/s²
Significant tornado parameter
0.1
Supercell composite
4.5

Open this sounding in Storm Lab

The text

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

035 
WWUS9 KMKC 210425
SEL4  
MKC WW 210418
OKZ000-211100-

URGENT - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WATCH NUMBER 604
STORM PREDICTION CENTER NORMAN OK
1118 PM CDT THU JUL 20 2000

THE STORM PREDICTION CENTER HAS ISSUED A
SEVERE THUNDERSTORM WATCH FOR PORTIONS OF

   NORTHERN AND CENTRAL OKLAHOMA                           

EFFECTIVE THIS THURSDAY NIGHT AND FRIDAY MORNING FROM 1145 PM UNTIL
600 AM CDT.

HAIL TO 1 INCH IN DIAMETER...THUNDERSTORM WIND GUSTS TO 70
MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE SEVERE THUNDERSTORM WATCH AREA IS ALONG AND 55 STATUTE MILES
NORTH AND SOUTH OF A LINE FROM 10 MILES WEST OF GAGE OKLAHOMA TO 55
MILES NORTHEAST OF MUSKOGEE OKLAHOMA.

REMEMBER...A SEVERE THUNDERSTORM WATCH MEANS CONDITIONS ARE
FAVORABLE FOR 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 602...

DISCUSSION...CONVECTIVE CLUSTER WITH A HISTORY OF WIND DAMAGE AND
LARGE HAIL MOVING SOUTHEASTWARD INTO OKLAHOMA WHERE AIR MASS QUITE
UNSTABLE WITH 2000 TO 3000 J/KG CAPES. STRONGLY VEERING WIND
PROFILE AT LOW LEVELS AND ABUNDANT MOISTURE IN BOUNDARY LAYER WILL
SUPPORT CONTINUED THREAT OF DAMAGING MOIST DOWNDRAFTS AND ISOLATED
HIGH PRECIPITATION SUPERCELLS.

AVIATION...A FEW SEVERE THUNDERSTORMS WITH HAIL SURFACE AND ALOFT
TO 1 INCH EXTREME TURBULENCE AND SURFACE WIND GUSTS TO 60 KNOTS. 
A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 500.  MEAN STORM MOTION
VECTOR 27040.

...ROGASH

370,0995 370,0944 352,0944 352,0995

Nearby

Severe Thunderstorm Watches in Oklahoma, 2000Every severe thunderstorm watch in 2000

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.