Alert archive / Missouri / Mesoscale Discussions in 2005

Mesoscale Discussion 643

April 21, 2005Adams County, Iowa; 14 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at Apr 21, 2005, 9:50 PM CDT for Adams County, Iowa; 14 counties in Missouri. It was in force for 55 min.

The area

The outline as issued.

The facts

Issued
Apr 21, 2005, 9:50 PM CDT (02:50 UTC)
Expired
Apr 21, 2005, 10:45 PM CDT
In force
55 min
Issued by
the Storm Prediction Center

Counties Adams County, IA, Caldwell County, MO, Carroll County, MO, Cass County, MO, Clay County, MO, Clinton County, MO, Daviess County, MO, DeKalb County, MO, Gentry County, MO, Jackson County, MO, Johnson County, MO, Lafayette County, MO, Pettis County, MO, Ray County, MO, Worth County, MO

The radar

The Pleasant Hill radar (KEAX), 33 km from the middle of the area, began a volume at 02:50 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

Topeka, KS (KTOP), launched 00:00Z, 2.8 hours before the alert went out and 138 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, Topeka, KS at 00:00Z on 2005-04-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 795 joules per kilogram.LCLEL10008507005003002001001 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, Topeka, KS at 00:00Z on 2005-04-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 square meters per square second.19395878Sfc1 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
795 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
1802 m above ground
0-6 km bulk shear
42 kt
0-1 km storm-relative helicity
19 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.6

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 220251
SWOMCD
SPC MCD 220250 
MOZ000-IAZ000-220345-

MESOSCALE DISCUSSION 0643
NWS STORM PREDICTION CENTER NORMAN OK
0950 PM CDT THU APR 21 2005

AREAS AFFECTED...NWRN/WCNTRL MO

CONCERNING...TORNADO WATCH 178...

VALID 220250Z - 220345Z

VALID PORTIONS OF TORNADO WATCH 178 ACROSS PORTIONS OF WCNTRL/NWRN
MO IS SET TO EXPIRE AT 04Z AND WILL NOT BE REISSUED.

PRIMARY LINEAR BAND OF STRONG-SEVERE TSTMS APPEARS TO BE EVOLVING
FROM NCNTRL TO SWRN MO LATE THIS EVENING...OR JUST EAST OF THE VALID
PORTIONS OF WT 178.  OTHER TSTMS HAVE BEEN STRUGGLING TO DEVELOP
ALONG THE DRYLINE/COLD FRONT ACROSS NWRN MO...BUT EARLIER TSTMS HAVE
PROBABLY EXHAUSTED SUBSTANTIAL INSTABILITY.  MOREOVER...THE LLJ IS
AIMED MORE INTO THE TSTMS DEVELOPING FARTHER EAST.

..RACY.. 04/22/2005

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

ATTN...WFO...DMX...EAX...

38409439 41219474 38869301 38399370

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Apr 21, 7:47 PM CDTMesoscale DiscussionSPCBarry, Barton, Camden, Cedar, Christian, Dade and 22 more88 min
Apr 21, 8:03 PM CDTMesoscale DiscussionSPCAudrain, Boone, Callaway, Franklin, Gasconade, Howard and 12 more87 min
Apr 21, 8:19 PM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Carter, Dunklin, Madison and 7 more86 min
Apr 21, 10:25 PM CDTMesoscale DiscussionSPCAudrain, Bollinger, Butler, Callaway, Camden, Carter and 38 more65 min
Apr 21, 11:50 PM CDTSevere Thunderstorm WatchSPCBollinger, Butler, Cape Girardeau, Carter, Crawford, Dent and 20 more6 hr
Apr 22, 3:09 AM CDTMesoscale DiscussionSPCBollinger, Butler, Cape Girardeau, Dunklin, Mississippi, New Madrid and 5 more66 min

Nearby

Mesoscale Discussions in Missouri, 2005Mesoscale Discussions in Iowa, 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.