Alert archive / Oklahoma / Mesoscale Discussions in 2005

Mesoscale Discussion 634

April 21, 200517 counties in Arkansas; McDonald County, Missouri; 31 counties in Oklahoma

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2005, 5:14 PM CDT for 17 counties in Arkansas; McDonald County, Missouri; 31 counties in Oklahoma. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Apr 21, 2005, 5:14 PM CDT (22:14 UTC)
Expired
Apr 21, 2005, 7:15 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
All 49 counties

Benton County, AR, Crawford County, AR, Franklin County, AR, Garland County, AR, Hot Spring County, AR, Howard County, AR, Johnson County, AR, Logan County, AR, Madison County, AR, Montgomery County, AR, Pike County, AR, Polk County, AR, Scott County, AR, Sebastian County, AR, Sevier County, AR, Washington County, AR, Yell County, AR, McDonald County, MO, Adair County, OK, Atoka County, OK, Carter County, OK, Cherokee County, OK, Choctaw County, OK, Coal County, OK, Craig County, OK, Creek County, OK, Delaware County, OK, Haskell County, OK, Hughes County, OK, Johnston County, OK, Latimer County, OK, LeFlore County, OK, Mayes County, OK, McCurtain County, OK, McIntosh County, OK, Murray County, OK, Muskogee County, OK, Nowata County, OK, Okfuskee County, OK, Okmulgee County, OK, Pittsburg County, OK, Pontotoc County, OK, Pushmataha County, OK, Rogers County, OK, Seminole County, OK, Sequoyah County, OK, Tulsa County, OK, Wagoner County, OK, Washington County, OK

The radar

The Western Arkansas radar (KSRX), 95 km from the middle of the area, began a volume at 22:16 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 watches that followed

Watches SPC issued over any of the same counties within four hours of this discussion.

The nearest sounding before it

Springfield, MO (KSGF), launched 12:00Z, 10.2 hours before the alert went out and 232 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, Springfield, MO at 12:00Z on 2005-04-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 780 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, Springfield, MO at 12:00Z on 2005-04-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 118 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
780 J/kg
Mixed-layer CIN
-135 J/kg
Mixed-layer LCL
696 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
118 m²/s²
0-3 km storm-relative helicity
93 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.

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SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 1:23 PM CDTMesoscale DiscussionSPCBenton, Boone, Carroll, Madison, Marion, Washington67 min
Apr 21, 1:45 PM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Fulton, Izard and 6 more5 hr
Apr 21, 5:22 PM CDTMesoscale DiscussionSPCClay, Greene, Lawrence, Randolph, Sharp53 min
Apr 21, 5:35 PM CDTSevere Thunderstorm WatchSPCClay, Craighead, Greene, Lawrence, Randolph, Sharp7 hr
Apr 21, 6:15 PM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Cleburne, Conway and 21 more7 hr
Apr 21, 3:34 AM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Daviess, DeKalb, Gentry and 4 more116 min
Apr 21, 11:13 AM CDTMesoscale DiscussionSPCPlatte2 hr
Apr 21, 12:15 PM CDTMesoscale DiscussionSPCBoone, Callaway, Cole, Cooper, Crawford, Franklin and 12 more2 hr
Apr 21, 1:10 PM CDTSevere Thunderstorm WatchSPCAdair, Audrain, Crawford, Franklin, Gasconade, Jefferson and 16 more6 hr
Apr 21, 3:05 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Carroll, Cass and 11 more85 min
Apr 21, 3:28 PM CDTMesoscale DiscussionSPCAudrain, Boone, Callaway, Cole, Franklin, Gasconade and 14 more92 min
Apr 21, 3:35 PM CDTTornado WatchSPCAndrew, Atchison, Bates, Benton, Buchanan, Caldwell and 19 more7 hr
Apr 21, 4:51 PM CDTMesoscale DiscussionSPCBuchanan, Clay, Clinton, Platte54 min
Apr 21, 5:52 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Audrain, Boone, Buchanan, Caldwell and 38 more53 min
Apr 21, 6:10 PM CDTTornado WatchSPCBarry, Barton, Camden, Cedar, Christian, Crawford and 27 more7 hr
Apr 21, 6:45 PM CDTSevere Thunderstorm WatchSPCAudrain, Boone, Caldwell, Callaway, Carroll, Chariton and 21 more6 hr
Apr 21, 6:51 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Cass, Clay and 12 more84 min
Apr 20, 8:45 PM CDTMesoscale DiscussionSPCCaddo, Canadian, Cleveland, Comanche, Cotton, Garfield and 9 more90 min
Apr 20, 9:51 PM CDTMesoscale DiscussionSPCAlfalfa, Beckham, Custer, Dewey, Ellis, Greer and 9 more84 min

Nearby

Mesoscale Discussions in Oklahoma, 2005Mesoscale Discussions in Arkansas, 2005Mesoscale Discussions in Missouri, 2005Every mesoscale discussion in 2005

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.