Alert archive / Illinois / Mesoscale Discussions in 2011

Mesoscale Discussion 1413

June 27, 20114 states

The Storm Prediction Center issued this mesoscale discussion at Jun 27, 2011, 12:58 AM CDT for 4 states. It was in force for 92 min.

The area

The outline as issued.

The facts

Issued
Jun 27, 2011, 12:58 AM CDT (05:58 UTC)
Expired
Jun 27, 2011, 2:30 AM CDT
In force
92 min
Issued by
the Storm Prediction Center
All 113 counties

Adams County, IL, Bond County, IL, Brown County, IL, Calhoun County, IL, Cass County, IL, Champaign County, IL, Christian County, IL, Clark County, IL, Clay County, IL, Clinton County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Edwards County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Greene County, IL, Hamilton County, IL, Hancock County, IL, Henderson County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Lawrence County, IL, Macon County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Mason County, IL, McDonough County, IL, Menard County, IL, Monroe County, IL, Montgomery County, IL, Morgan County, IL, Moultrie County, IL, Perry County, IL, Piatt County, IL, Pike County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Shelby County, IL, Vermilion County, IL, Wabash County, IL, Washington County, IL, Wayne County, IL, White County, IL, Clay County, IN, Parke County, IN, Sullivan County, IN, Vermillion County, IN, Vigo County, IN, Atchison County, KS, Doniphan County, KS, Douglas County, KS, Franklin County, KS, Jefferson County, KS, Johnson County, KS, Leavenworth County, KS, Miami County, KS, Shawnee County, KS, Wyandotte County, KS, Audrain County, MO, Benton County, MO, Boone County, MO, Buchanan County, MO, Caldwell County, MO, Callaway County, MO, Carroll County, MO, Cass County, MO, City of Saint Louis, MO, Clay County, MO, Clinton County, MO, Cole County, MO, Cooper County, MO, Crawford County, MO, Franklin County, MO, Gasconade County, MO, Henry County, MO, Howard County, MO, Jackson County, MO, Jefferson County, MO, Johnson County, MO, Lafayette County, MO, Lincoln County, MO, Maries County, MO, Marion County, MO, Miller County, MO, Moniteau County, MO, Monroe County, MO, Montgomery County, MO, Morgan County, MO, Osage County, MO, Pettis County, MO, Phelps County, MO, Pike County, MO, Platte County, MO, Ralls County, MO, Ray County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Saline County, MO, Warren County, MO, Washington County, MO

The radar

The St Louis radar (KLSX), 131 km from the middle of the area, began a volume at 05:58 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 watches that followed

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

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 6.0 hours before the alert went out and 278 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, Davenport, at 00:00Z on 2011-06-27Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 15 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, Davenport, at 00:00Z on 2011-06-27The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -37 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
15 J/kg
Mixed-layer CIN
-398 J/kg
Mixed-layer LCL
1115 m above ground
0-6 km bulk shear
36 kt
0-1 km storm-relative helicity
-37 m²/s²
0-3 km storm-relative helicity
115 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.

202 
ACUS11 KWNS 270559
SWOMCD
SPC MCD 270558
INZ000-ILZ000-MOZ000-IAZ000-KSZ000-270730-

MESOSCALE DISCUSSION 1413
NWS STORM PREDICTION CENTER NORMAN OK
1258 AM CDT MON JUN 27 2011

AREAS AFFECTED...NE KS...NRN AND CNTRL MO...CNTRL IL

CONCERNING...SEVERE POTENTIAL...WATCH LIKELY

VALID 270558Z - 270730Z

A NEW WW PROBABLY WILL BE NEEDED ACROSS AT LEAST PARTS OF NORTHEAST
KANSAS INTO CENTRAL/SOUTHEAST MISSOURI.  SEVERE WATCHES 561 AND 564
MAY BE EXTENDED LOCALLY IN TIME FOR AFFECTED ILLINOIS PORTIONS.

SMALL MESOSCALE CONVECTIVE SYSTEM APPEARS TO HAVE UNDERGONE
SUBSTANTIAL WEAKENING ACROSS CENTRAL ILLINOIS DURING THE PAST HOUR
OR SO.  WHILE THERE MAY STILL BE SOME SHORT TERM FLUCTUATIONS IN
INTENSITY...IT CURRENTLY SEEMS PROBABLE THAT ACTIVITY WILL CONTINUE
TO WEAKEN AS IT INGESTS AIR FROM A MORE STABLE BOUNDARY LAYER OVER
CENTRAL INDIANA.  SIMILAR TRENDS MAY TAKE PLACE SHORTLY WITH THE
MORE SIGNIFICANT UPSTREAM MESOSCALE CONVECTIVE SYSTEM PROPAGATING
TOWARD THE ST. LOUIS AREA...AT LEAST FOR AREAS OF ILLINOIS NORTH AND
EAST OF THE ST. LOUIS.

IT MAY BE THAT NEW/STRENGTHENING CONVECTIVE DEVELOPMENT ACROSS PARTS
OF NORTHEAST KANSAS INTO AREAS NEAR/NORTH OF THE KANSAS CITY AREA
BECOMES ANOTHER SIGNIFICANT MESOSCALE CONVECTIVE SYSTEM BETWEEN NOW
AND 07-09Z.  ACTIVITY IS BEING SUPPORTED BY LARGE-SCALE ASCENT
ASSOCIATED WITH WARM ADVECTION ON THE NOSE OF A 40-60+ KT SOUTHERLY
LOW-LEVEL JET.  AND...AS A SURFACE COLD POOL CONGEALS AND
STRENGTHENS...SOUTHEASTERLY NEAR SURFACE INFLOW EMANATING FROM A
WARMER AND MORE UNSTABLE BOUNDARY LAYER ACROSS WEST CENTRAL MISSOURI
COULD CONTRIBUTE TO FURTHER INTENSIFICATION AND AN INCREASING
DAMAGING WIND THREAT NEAR/EAST AND SOUTHEAST OF THE KANSAS CITY
METROPOLITAN AREA.

..KERR.. 06/27/2011

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

ATTN...WFO...IND...PAH...LOT...ILX...LSX...DVN...SGF...EAX...
TOP...

LAT...LON   39189599 39929504 39579324 39379250 39829187 40389147
            40979089 40309002 40078931 40408838 40238770 39548689
            38008819 37629109 38109267 38279432 38309514 38789590
            39189599

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 26, 7:12 PM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 35 more6 hr
Jun 26, 10:02 PM CDTSevere Thunderstorm WatchSPCHancock, Henderson, McDonough, Mercer, Rock Island, Warren5 hr
Jun 27, 1:32 AM CDTSevere Thunderstorm WatchSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 43 more7 hr
Jun 27, 3:14 AM CDTMesoscale DiscussionSPCAlexander, Bond, Champaign, Clark, Clay, Clinton and 39 more91 min
Jun 27, 5:38 AM CDTMesoscale DiscussionSPCAdams, Bond, Brown, Calhoun, Cass, Champaign and 35 more97 min
Jun 27, 11:30 AM CDTMesoscale DiscussionSPCHardin, Massac, Pope90 min
Jun 27, 12:01 PM CDTSevere Thunderstorm WatchSPCPerry, Spencer, Vanderburgh, Warrick4 hr
Jun 26, 9:25 PM CDTMesoscale DiscussionSPCAtchison, Brown, Jackson, Marshall, Nemaha, Pottawatomie65 min
Jun 26, 10:06 PM CDTMesoscale DiscussionSPCAdair, Andrew, Audrain, Boone, Buchanan, Caldwell and 29 more84 min
Jun 27, 3:54 PM CDTMesoscale DiscussionSPCBarry, Barton, Camden, Cedar, Christian, Dade and 21 more2 hr

Nearby

Mesoscale Discussions in Illinois, 2011Mesoscale Discussions in Missouri, 2011Mesoscale Discussions in Kansas, 2011Every mesoscale discussion in 2011

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.