Alert archive / Missouri / Mesoscale Discussions in 2014

Mesoscale Discussion 554

May 10, 20148 counties in Illinois; 28 counties in Missouri

The Storm Prediction Center issued this mesoscale discussion at May 10, 2014, 7:55 PM CDT for 8 counties in Illinois; 28 counties in Missouri. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
May 10, 2014, 7:55 PM CDT (00:55 UTC)
Expired
May 10, 2014, 9:30 PM CDT
In force
95 min
Issued by
the Storm Prediction Center
All 36 counties

Calhoun County, IL, Greene County, IL, Jersey County, IL, Macoupin County, IL, Madison County, IL, Monroe County, IL, Pike County, IL, Saint Clair County, IL, Audrain County, MO, Boone County, MO, Callaway County, MO, Carroll County, MO, Chariton County, MO, City of Saint Louis, MO, Cole County, MO, Cooper County, MO, Franklin County, MO, Gasconade County, MO, Howard County, MO, Jefferson County, MO, Lincoln County, MO, Linn County, MO, Macon County, MO, Marion County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Osage County, MO, Pike County, MO, Ralls County, MO, Randolph County, MO, Saint Charles County, MO, Saint Louis County, MO, Saline County, MO, Shelby County, MO, Warren County, MO

The radar

The St Louis radar (KLSX), 111 km from the middle of the area, began a volume at 00:58 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, 0.9 hours before the alert went out and 292 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 2014-05-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 691 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 2014-05-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 43 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
691 J/kg
Mixed-layer CIN
-30 J/kg
Mixed-layer LCL
1852 m above ground
0-6 km bulk shear
30 kt
0-1 km storm-relative helicity
43 m²/s²
0-3 km storm-relative helicity
223 m²/s²
Significant tornado parameter
0.0
Supercell composite
3.0

Open this sounding in Storm Lab

The text

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

021 
ACUS11 KWNS 110056
SWOMCD
SPC MCD 110055 
ILZ000-MOZ000-110230-

MESOSCALE DISCUSSION 0554
NWS STORM PREDICTION CENTER NORMAN OK
0755 PM CDT SAT MAY 10 2014

AREAS AFFECTED...CNTRL/NRN MO...WRN IL

CONCERNING...SEVERE THUNDERSTORM WATCH 138...

VALID 110055Z - 110230Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 138
CONTINUES.

SUMMARY...LARGE HAIL AND DAMAGING WIND THREAT WILL CONTINUE ACROSS
WW 138. AN ISOLATED TORNADO THREAT WILL ALSO EXIST WITH PERSISTENT
DISCRETE SUPERCELLS THIS EVENING.

DISCUSSION...AS OF 0030Z...A SUPERCELL WHICH EVOLVED OUT OF A
CLUSTER OF SEVERE TSTMS CONTINUES ESEWD ACROSS THE NRN HALF OF WW
138...WHILE A DISCRETE SUPERCELL CONTINUES ACROSS SALINE/CARROLL
COUNTIES IN MISSOURI. THIS ACTIVITY IS OCCURRING ALONG AND JUST
NORTH OF A WEAK SFC BOUNDARY DRAPED NORTH OF A STL-COU-DMO LINE IN
AN ENVIRONMENT CHARACTERIZED BY MODERATE INSTABILITY AND STRONG
DEEP-LAYER SHEAR. ASCENT TO THE NORTH OF THE BOUNDARY AIDED BY A
MODEST LOW-LEVEL JET WILL LIKELY SUSTAIN THIS ACTIVITY THROUGH MUCH
OF THE EVENING...WITH FAVORABLY VEERING WIND PROFILES CONTINUING TO
SUPPORT DISCRETE SUPERCELLS AND ORGANIZED LINE SEGMENTS. 

WHILE A RELATIVELY DRY BOUNDARY LAYER CONTINUES TO LIMIT THE OVERALL
TORNADO THREAT...THE PRESENCE OF DISCRETE SUPERCELL STRUCTURES IN
THE VICINITY OF ENHANCED LOW-LEVEL SHEAR ALONG AND NORTH OF THE
BOUNDARY WILL RESULT IN A THREAT OF AN ISOLATED TORNADO OR TWO.
GIVEN THE ISOLATED NATURE OF THE TORNADO THREAT...A TORNADO WATCH
DOES NOT APPEAR TO BE WARRANTED AT THIS TIME. OTHERWISE...LARGE HAIL
WILL CONTINUE TO BE A SIGNIFICANT THREAT...AND AN ENHANCED WIND
THREAT WILL BE PRESENT WITH ANY BOWING LINE SEGMENTS THAT MAY
EVOLVE.

..DEAN.. 05/11/2014

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

ATTN...WFO...ILX...LSX...SGF...EAX...

LAT...LON   38579301 38859340 39099344 39259349 39479351 39749345
            39959328 40019302 40059260 40039212 39839130 39569056
            39298969 38938953 38558960 38268999 38219038 38139087
            38209135 38249172 38319210 38579301

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 10, 10:22 PM CDTMesoscale DiscussionSPCCalhoun, Jersey, Madison, Monroe, Randolph, Saint Clair83 min
May 11, 9:16 AM CDTMesoscale DiscussionSPCMercer, Rock Island89 min
May 11, 10:47 AM CDTMesoscale DiscussionSPCHancock118 min
May 11, 11:53 AM CDTTornado WatchSPCCarroll, Henderson, Henry, Mercer, Rock Island, Warren and 1 more7 hr
May 11, 12:51 PM CDTMesoscale DiscussionSPCCarroll, Henderson, Jo Daviess, Mercer, Rock Island, Whiteside54 min
May 11, 2:36 PM CDTMesoscale DiscussionSPCMercer84 min
May 11, 3:05 PM CDTSevere Thunderstorm WatchSPCBoone, Bureau, Cook, DeKalb, DuPage, Ford and 23 more7 hr
May 11, 5:09 PM CDTMesoscale DiscussionSPCBoone, Bureau, Cook, DeKalb, DuPage, Grundy and 21 more66 min
May 11, 5:49 PM CDTMesoscale DiscussionSPCClark, Coles, Edgar56 min
May 10, 7:59 PM CDTMesoscale DiscussionSPCAndrew, Bates, Buchanan, Caldwell, Carroll, Cass and 19 more91 min
May 11, 1:19 AM CDTMesoscale DiscussionSPCAtchison, Nodaway2 hr
May 11, 7:02 AM CDTMesoscale DiscussionSPCAtchison, Holt118 min
May 11, 12:49 PM CDTMesoscale DiscussionSPCAndrew, Atchison, Buchanan, DeKalb, Gentry, Holt and 2 more116 min
May 11, 2:21 PM CDTTornado WatchSPCAtchison8 hr

Nearby

Mesoscale Discussions in Missouri, 2014Mesoscale Discussions in Illinois, 2014Every mesoscale discussion in 2014

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.