Alert archive / Oklahoma / Mesoscale Discussions in 2004

Mesoscale Discussion 921

May 26, 200421 counties in Oklahoma; Childress County, Texas

The Storm Prediction Center issued this mesoscale discussion at May 26, 2004, 5:37 PM CDT for 21 counties in Oklahoma; Childress County, Texas. It was in force for 83 min.

The area

The outline as issued.

The facts

Issued
May 26, 2004, 5:37 PM CDT (22:37 UTC)
Expired
May 26, 2004, 7:00 PM CDT
In force
83 min
Issued by
the Storm Prediction Center
All 22 counties

Alfalfa County, OK, Beckham County, OK, Blaine County, OK, Caddo County, OK, Canadian County, OK, Comanche County, OK, Custer County, OK, Dewey County, OK, Garfield County, OK, Grant County, OK, Greer County, OK, Harmon County, OK, Jackson County, OK, Kay County, OK, Kingfisher County, OK, Kiowa County, OK, Major County, OK, Roger Mills County, OK, Washita County, OK, Woods County, OK, Woodward County, OK, Childress County, TX

The radar

The Altus AFB radar (KFDR), 121 km from the middle of the area, began a volume at 22:36 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.

The nearest sounding before it

Fort Sill, OK (KFSI), launched 12:00Z, 10.6 hours before the alert went out and 90 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 2004-05-26Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 708 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Fort Sill, OK at 12:00Z on 2004-05-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 126 square meters per square second.1939587897Sfc1 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
708 J/kg
Mixed-layer CIN
-291 J/kg
Mixed-layer LCL
1122 m above ground
0-6 km bulk shear
43 kt
0-1 km storm-relative helicity
126 m²/s²
0-3 km storm-relative helicity
103 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.

305 
ACUS11 KWNS 262237
SWOMCD
SPC MCD 262237 
OKZ000-TXZ000-270000-

MESOSCALE DISCUSSION 0921
NWS STORM PREDICTION CENTER NORMAN OK
0537 PM CDT WED MAY 26 2004

AREAS AFFECTED...WRN/CENTRAL OK

CONCERNING...TORNADO WATCH 298...

VALID 262237Z - 270000Z

CONTINUE WW.

AT 2220Z...SUPERCELL WAS LOCATED 40 ENE CSM MOVING ENEWD AT 40KT.
PRESENT MOTION SUGGESTS STORM IS ROOTED ABOVE THE BOUNDARY LAYER
WITH LARGE HAIL THE PRIMARY THREAT. EXTRAPOLATION TAKES THIS STORM
INTO THE WRN/NRN PORTION OF THE OKC METRO AREA BETWEEN
2330-0000Z...WITH POTENTIAL FOR CONTINUED STORM SPLITS DURING THE
NEXT 1-2 HOURS. AN ADDITIONAL WW MAY BE NEEDED EWD IN CENTRAL OK TO
ADDRESS SEVERE THREAT ASSOCIATED WITH THESE CELLS.

IF RIGHT MOVING CELL SLOWS DOWN AND MOVES WITH MORE OF AN ELY
COMPONENT...THIS WOULD STRONGLY INDICATE UPDRAFT HAS BECOME ROOTED
IN MORE UNSTABLE BOUNDARY LAYER AIR MASS /100MB MLCAPE AROUND 3000
J/KG/. TLX VAD INDICATES A SURFACE BASED SUPERCELL WOULD MOVE
ROUGHLY 270/20 KT GIVEN PRESENT VERTICAL WIND PROFILE. THIS WOULD
CONDITIONALLY INCREASE TORNADO THREAT...BUT PRESENCE OF MODERATE
CAPPING INVERSION MAKES THIS SCENARIO UNCERTAIN.

OTHER ISOLATED STORM DEVELOPMENT IS POSSIBLE ACROSS FAR SWRN OK IN
VICINITY OF NOW RETREATING DRYLINE OVER SRN JACKSON COUNTY OK AND
HARDEMAN COUNTY TX.

..BANACOS.. 05/26/2004

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...OUN...LUB...AMA...

34439847 34430056 36959901 36909693

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 25, 7:07 PM CDTMesoscale DiscussionSPCCarter, Comanche, Cotton, Garvin, Jefferson, Johnston and 5 more113 min
May 25, 11:28 PM CDTMesoscale DiscussionSPCHarmon, Jackson2 hr
May 26, 12:12 PM CDTMesoscale DiscussionSPCBeckham, Custer, Dewey, Greer, Harmon, Jackson and 3 more3 hr
May 26, 3:50 PM CDTSevere Thunderstorm WatchSPCGreer, Harmon, Jackson6 hr
May 26, 3:55 PM CDTTornado WatchSPCAlfalfa, Beckham, Blaine, Caddo, Canadian, Comanche and 16 more6 hr
May 26, 6:07 PM CDTMesoscale DiscussionSPCGreer, Harmon, Jackson83 min
May 26, 6:25 PM CDTTornado WatchSPCCleveland, Creek, Grady, Lincoln, Logan, McClain and 7 more5 hr
May 26, 6:37 PM CDTMesoscale DiscussionSPCAlfalfa, Blaine, Caddo, Canadian, Cleveland, Comanche and 24 more83 min

Nearby

Mesoscale Discussions in Oklahoma, 2004Mesoscale Discussions in Texas, 2004Every mesoscale discussion in 2004

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.