Alert archive / Illinois / Mesoscale Discussions in 2015
Mesoscale Discussion 252
The Storm Prediction Center issued this mesoscale discussion at Apr 9, 2015, 3:45 PM CDT for 31 counties in Illinois; Ballard County, Kentucky; 20 counties in Missouri. It was in force for 60 min.
The area
The outline as issued.
The facts
- Issued
- Apr 9, 2015, 3:45 PM CDT (20:45 UTC)
- Expired
- Apr 9, 2015, 4:45 PM CDT
- In force
- 60 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 80%
All 52 counties
Alexander County, IL, Bond County, IL, Clay County, IL, Clinton County, IL, Cumberland County, IL, Effingham County, IL, Fayette County, IL, Franklin County, IL, Hamilton County, IL, Jackson County, IL, Jasper County, IL, Jefferson County, IL, Jersey County, IL, Johnson County, IL, Macoupin County, IL, Madison County, IL, Marion County, IL, Massac County, IL, Monroe County, IL, Montgomery County, IL, Perry County, IL, Pulaski County, IL, Randolph County, IL, Richland County, IL, Saint Clair County, IL, Saline County, IL, Shelby County, IL, Union County, IL, Washington County, IL, Wayne County, IL, Williamson County, IL, Ballard County, KY, Bollinger County, MO, Butler County, MO, Cape Girardeau County, MO, Carter County, MO, City of Saint Louis, MO, Crawford County, MO, Franklin County, MO, Iron County, MO, Jefferson County, MO, Madison County, MO, Perry County, MO, Reynolds County, MO, Saint Charles County, MO, Saint Francois County, MO, Saint Louis County, MO, Sainte Genevieve County, MO, Scott County, MO, Stoddard County, MO, Washington County, MO, Wayne County, MO
The radar
The St Louis radar (KLSX), 96 km from the middle of the area, began a volume at 20:48 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
Lincoln, IL (KILX), launched 12:00Z, 8.8 hours before the alert went out and 254 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.
- Mixed-layer CAPE
- 114 J/kg
- Mixed-layer CIN
- -122 J/kg
- Mixed-layer LCL
- 1085 m above ground
- 0-6 km bulk shear
- 26 kt
- 0-1 km storm-relative helicity
- 140 m²/s²
- 0-3 km storm-relative helicity
- 172 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.4
The text
As transmitted, in the capitals the NWS used until 2016.
085
ACUS11 KWNS 092046
SWOMCD
SPC MCD 092045
ILZ000-KYZ000-MOZ000-092145-
MESOSCALE DISCUSSION 0252
NWS STORM PREDICTION CENTER NORMAN OK
0345 PM CDT THU APR 09 2015
AREAS AFFECTED...E-CNTRL/SE MO...SRN IL
CONCERNING...SEVERE POTENTIAL...WATCH LIKELY
VALID 092045Z - 092145Z
PROBABILITY OF WATCH ISSUANCE...80 PERCENT
SUMMARY...A WATCH WILL LIKELY BE NEEDED WITHIN THE NEXT FEW HOURS TO
COVER THE SEVERE THREAT EXPECTED TO DEVELOP ACROSS THE REGION.
DISCUSSION...VISIBLE SATELLITE IMAGERY ACROSS E-CNTRL MO IS
BEGINNING TO INDICATE THE CAP MAY HAVE WEAKENED ENOUGH TO SUPPORT
INITIATION OF SURFACE-BASED CONVECTION. BOTH VISIBLE SATELLITE
IMAGERY AND OBJECTIVE ANALYSIS INDICATE AREAS FARTHER W /SRN IL/ ARE
STILL CAPPED BUT CONTINUED HEATING AND INCREASING LARGE-SCALE ASCENT
SHOULD LEAD TO THE EROSION OF CONVECTIVE INHIBITION WITHIN THE NEXT
FEW HOURS. MOST CERTAIN SEVERE THREAT WILL BE RELATED TO THE TSTMS
DEVELOPING ALONG THE COLD FRONT DRAPED FROM S-CNTRL IA SWD ACROSS
CNTRL MO AND INTO NE OK. THESE STORMS WILL LIKELY BE CAPABLE OF
PRODUCING DAMAGING WINDS AND LARGE HAIL BY THE TIME THEY ENTER
E-CNTRL MO. A MORE UNCERTAIN SEVERE THREAT IS TIED TO POTENTIAL
DEVELOPMENT AHEAD OF THE COLD FRONT WITHIN THE WARM SECTOR. WARM
SECTOR ENVIRONMENT CHARACTERIZED BY TEMPERATURES IN THE UPPER 70S
AND LOW 80S...DEWPOINTS IN THE LOW TO MID 60S...MLCAPE OVER 15OO J
PER KG...AND EFFECTIVE BULK SHEAR OF AT LEAST 30 KT IS SUPPORTIVE OF
SUPERCELLS WITH ANY DISCRETE WARM SECTOR DEVELOPMENT.
..MOSIER/GRAMS.. 04/09/2015
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...PAH...ILX...MEG...LSX...SGF...
LAT...LON 38049143 38879090 39458984 39418796 38698800 37168872
36588986 36679090 38049143SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 8, 7:04 PM CDT | Mesoscale Discussion | SPC | Franklin, Gallatin, Hardin, Jackson, Johnson, Pope and 3 more | 116 min |
| Apr 9, 12:29 PM CDT | Mesoscale Discussion | SPC | Bureau, Carroll, Henderson, Henry, Jo Daviess, Knox and 8 more | 91 min |
| Apr 9, 12:58 PM CDT | Tornado Watch | SPC | Adams, Brown, Carroll, Hancock, Henderson, Henry and 8 more | 6 hr |
| Apr 9, 1:48 PM CDT | Tornado Watch | SPC | Boone, Bureau, Cass, Champaign, Christian, Cook and 36 more | 9 hr |
| Apr 9, 3:12 PM CDT | Mesoscale Discussion | SPC | Adams, Boone, Brown, Bureau, Calhoun, Carroll and 51 more | 93 min |
| Apr 9, 4:40 PM CDT | Tornado Watch | SPC | Bond, Calhoun, Clinton, Fayette, Greene, Jersey and 8 more | 6 hr |
| Apr 9, 6:04 PM CDT | Mesoscale Discussion | SPC | Boone, Bureau, Carroll, Cass, DeKalb, DeWitt and 37 more | 86 min |
| Apr 9, 6:48 PM CDT | Tornado Watch | SPC | Alexander, Clark, Clay, Coles, Crawford, Cumberland and 26 more | 6 hr |
| Apr 9, 12:51 PM CDT | Mesoscale Discussion | SPC | Boone, Bracken, Campbell, Fleming, Greenup, Kenton and 5 more | 54 min |
| Apr 9, 1:26 PM CDT | Severe Thunderstorm Watch | SPC | Anderson, Bath, Boone, Bourbon, Boyd, Bracken and 30 more | 8 hr |
| Apr 9, 3:01 PM CDT | Mesoscale Discussion | SPC | Bath, Boone, Bourbon, Boyd, Bracken, Campbell and 27 more | 59 min |
| Apr 9, 3:49 PM CDT | Mesoscale Discussion | SPC | Anderson, Boone, Bracken, Campbell, Carroll, Franklin and 12 more | 56 min |
| Apr 9, 6:11 PM CDT | Mesoscale Discussion | SPC | Fulton | 64 min |
| Apr 9, 1:32 PM CDT | Mesoscale Discussion | SPC | Barry, Barton, Benton, Camden, Cedar, Dade and 11 more | 118 min |
| Apr 9, 2:32 PM CDT | Severe Thunderstorm Watch | SPC | Barry, Benton, Camden, Christian, Dade, Dallas and 22 more | 7 hr |
| Apr 9, 6:32 PM CDT | Severe Thunderstorm Watch | SPC | Dunklin, Pemiscot | 5 hr |
Nearby
Mesoscale Discussions in Illinois, 2015Mesoscale Discussions in Missouri, 2015Mesoscale Discussions in Kentucky, 2015Every mesoscale discussion in 2015
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.