Alert archive / Missouri / Mesoscale Discussions in 2018

Mesoscale Discussion 331

May 3, 201812 counties in Arkansas; 9 counties in Illinois; 39 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 3, 2018, 2:32 AM CDT for 12 counties in Arkansas; 9 counties in Illinois; 39 counties in Missouri. It was in force for 88 min.

The area

The outline as issued.

The facts

Issued
May 3, 2018, 2:32 AM CDT (07:32 UTC)
Expired
May 3, 2018, 4:00 AM CDT
In force
88 min
Issued by
the Storm Prediction Center
All 60 counties

Baxter County, AR, Boone County, AR, Carroll County, AR, Franklin County, AR, Fulton County, AR, Izard County, AR, Johnson County, AR, Marion County, AR, Newton County, AR, Searcy County, AR, Sharp County, AR, Stone County, AR, Calhoun County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Monroe County, IL, Randolph County, IL, Saint Clair County, IL, Scott County, IL, Camden County, MO, Carter County, MO, Christian County, MO, City of Saint Louis, MO, Cole County, MO, Crawford County, MO, Dallas County, MO, Dent County, MO, Douglas County, MO, Franklin County, MO, Gasconade County, MO, Howell County, MO, Iron County, MO, Jefferson County, MO, Laclede County, MO, Lincoln County, MO, Madison County, MO, Maries County, MO, Miller County, MO, Montgomery County, MO, Oregon County, MO, Osage County, MO, Ozark County, MO, Phelps County, MO, Pulaski County, MO, Reynolds County, MO, Ripley County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Shannon County, MO, Taney County, MO, Texas County, MO, Warren County, MO, Washington County, MO, Wayne County, MO, Webster County, MO, Wright County, MO

The radar

The Springfield radar (KSGF), 129 km from the middle of the area, began a volume at 07:34 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

Springfield, MO (KSGF), launched 00:00Z, 7.5 hours before the alert went out and 172 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 00:00Z on 2018-05-03Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1170 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 00:00Z on 2018-05-03The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 113 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
1170 J/kg
Mixed-layer CIN
-40 J/kg
Mixed-layer LCL
1041 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
113 m²/s²
0-3 km storm-relative helicity
164 m²/s²
Significant tornado parameter
1.0
Supercell composite
5.6

Open this sounding in Storm Lab

The text

As transmitted.

801 
ACUS11 KWNS 030733
SWOMCD
SPC MCD 030732 
ILZ000-MOZ000-ARZ000-030900-

Mesoscale Discussion 0331
NWS Storm Prediction Center Norman OK
0232 AM CDT Thu May 03 2018

Areas affected...Northwest Arkansas...much of Missouri...western
Illinois

Concerning...Severe Thunderstorm Watch 68...

Valid 030732Z - 030900Z

The severe weather threat for Severe Thunderstorm Watch 68
continues.

SUMMARY...A line of storms will continue east across northern
Arkansas, southern and eastern Missouri, and western Illinois with
mainly a threat of locally damaging wind gusts.

DISCUSSION...A somewhat disjointed line of storms currently extends
from western IL into central MO, and approaching north central AR. A
relatively warm and moist air mass exists ahead of the line, with
dewpoints mainly in the mid 60s F. Surface temperatures remain in
the mid 70s F, but forecast soundings indicate this is a bit cool
relative to 700 mb temperatures resulting in a poor lapse rate.
Still, objective analysis indicates up to 400 m2/s2 effective SRH,
suggesting brief areas of rotation are possible along the line due
to sufficient instability.

..Jewell.. 05/03/2018

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...PAH...ILX...MEG...LSX...LZK...SGF...TSA...

LAT...LON   35399429 36059364 37289325 37879295 38409254 39319109
            39659047 39688991 39218951 38208957 37069017 35919176
            35639250 35399328 35399429

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 2, 10:20 PM CDTMesoscale DiscussionSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 6 more115 min
May 2, 11:09 PM CDTSevere Thunderstorm WatchSPCBaxter, Benton, Boone, Carroll, Crawford, Franklin and 12 more7 hr
May 3, 9:02 AM CDTMesoscale DiscussionSPCCrawford, Franklin, Sebastian, Washington88 min
May 3, 12:35 PM CDTMesoscale DiscussionSPCBoone, Carroll, Clark, Conway, Crawford, Franklin and 22 more85 min
May 3, 1:44 PM CDTSevere Thunderstorm WatchSPCBaxter, Clark, Clay, Cleburne, Conway, Craighead and 34 more4 hr
May 3, 3:45 PM CDTMesoscale DiscussionSPCArkansas, Clark, Clay, Cleburne, Cleveland, Craighead and 25 more60 min
May 3, 4:52 PM CDTMesoscale DiscussionSPCBaxter, Clark, Clay, Cleburne, Cleveland, Conway and 31 more53 min
May 2, 7:21 PM CDTMesoscale DiscussionSPCBoone, Bureau, Carroll, Cook, DeKalb, DuPage and 24 more84 min
May 2, 10:01 PM CDTMesoscale DiscussionSPCBureau, DeKalb, DuPage, Grundy, Henderson, Henry and 18 more89 min
May 2, 10:51 PM CDTSevere Thunderstorm WatchSPCCass, Cook, DeKalb, DuPage, Ford, Fulton and 23 more4 hr
May 3, 1:57 AM CDTMesoscale DiscussionSPCBureau, Cook, DeKalb, DeWitt, DuPage, Ford and 22 more93 min
May 2, 8:00 PM CDTMesoscale DiscussionSPCAdair, Andrew, Atchison, Bates, Benton, Buchanan and 33 more90 min
May 2, 11:09 PM CDTMesoscale DiscussionSPCMcDonald96 min
May 3, 2:36 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Caldwell, Clay, Clinton and 10 more114 min
May 3, 2:57 PM CDTSevere Thunderstorm WatchSPCAndrew, Atchison, Buchanan, Gentry, Holt, Nodaway and 1 more6 hr
May 3, 5:58 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, Gentry, Holt, Nodaway and 1 more92 min

Nearby

Mesoscale Discussions in Missouri, 2018Mesoscale Discussions in Arkansas, 2018Mesoscale Discussions in Illinois, 2018Every mesoscale discussion in 2018

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.