Alert archive / Illinois / Mesoscale Discussions in 2013

Mesoscale Discussion 511

April 17, 201318 counties in Illinois

The Storm Prediction Center issued this mesoscale discussion at Apr 17, 2013, 10:48 PM CDT for 18 counties in Illinois. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued: Apr 17, 2013, 10:48 PM CDT (03:48 UTC)
Expired: Apr 17, 2013, 11:45 PM CDT
In force: 57 min
Issued by: the Storm Prediction Center

Counties Champaign County, IL, Christian County, IL, Coles County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Fulton County, IL, Logan County, IL, Macon County, IL, Mason County, IL, McLean County, IL, Menard County, IL, Moultrie County, IL, Peoria County, IL, Piatt County, IL, Sangamon County, IL, Shelby County, IL, Tazewell County, IL

The radar

The Lincoln radar (KILX), 11 km from the middle of the area, began a volume at 03:50 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

Lincoln, IL (KILX), launched 00:00Z, 3.8 hours before the alert went out and 51 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 412 m above ground
0-6 km bulk shear: 68 kt
0-1 km storm-relative helicity: 356 m²/s²
0-3 km storm-relative helicity: 444 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 11.4

Open this sounding in Storm Lab

The text

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

148 
ACUS11 KWNS 180348
SWOMCD
SPC MCD 180348 
ILZ000-180445-

MESOSCALE DISCUSSION 0511
NWS STORM PREDICTION CENTER NORMAN OK
1048 PM CDT WED APR 17 2013

AREAS AFFECTED...CNTRL IL

CONCERNING...TORNADO WATCH 118...

VALID 180348Z - 180445Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 118 CONTINUES.

SUMMARY...THE SVR THREAT IS DIMINISHING ACROSS WW118.

DISCUSSION...ONGOING ELEVATED THUNDERSTORMS NW OF A LINE FROM SPI TO
BMI MAY PRODUCE SMALL HAIL DURING THE NEXT FEW HOURS.
OTHERWISE...STRONG STORMS WILL BE UNLIKELY DURING THE NEXT SEVERAL
HOURS...AS CONVECTION IS NOT EXPECTED TO BE ROOTED IN THE BOUNDARY
LAYER ACROSS REMAINING VALID PORTIONS OF WW118. AS SUCH...THE WW
WILL BE ALLOWED TO EXPIRE ON SCHEDULE AT 05Z...OR MAY BE CANCELLED
EARLY.

..COHEN.. 04/18/2013

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

ATTN...WFO...LOT...ILX...

LAT...LON   40439043 40988997 40408845 40248782 39598771 39338895
            39688988 40439043

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Apr 17, 8:21 PM CDT	Mesoscale Discussion	SPC	Cass, Champaign, Christian, Coles, DeWitt, Douglas and 21 more	84 min
Apr 17, 8:53 PM CDT	Mesoscale Discussion	SPC	Calhoun, Greene, Jersey, Pike, Scott	97 min
Apr 17, 9:57 PM CDT	Tornado Watch	SPC	Adams, Brown, Pike	7 hr
Apr 17, 11:46 PM CDT	Mesoscale Discussion	SPC	Calhoun, Greene, Morgan, Pike, Scott	89 min
Apr 18, 2:01 AM CDT	Mesoscale Discussion	SPC	Calhoun, Jersey	89 min
Apr 18, 4:02 AM CDT	Mesoscale Discussion	SPC	Calhoun, Greene, Jersey, Monroe	58 min
Apr 18, 5:36 AM CDT	Mesoscale Discussion	SPC	Bond, Clinton, Fayette, Madison, Monroe, Montgomery and 3 more	54 min
Apr 18, 5:42 AM CDT	Tornado Watch	SPC	Bond, Clinton, Fayette, Jersey, Macoupin, Madison and 6 more	8 hr
Apr 18, 7:25 AM CDT	Mesoscale Discussion	SPC	Champaign, Clark, Clay, Coles, Crawford, Cumberland and 17 more	95 min
Apr 18, 8:31 AM CDT	Tornado Watch PDS	SPC	Clark, Clay, Coles, Crawford, Cumberland, Douglas and 6 more	7 hr
Apr 18, 9:25 AM CDT	Tornado Watch	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more	8 hr
Apr 18, 11:14 AM CDT	Mesoscale Discussion	SPC	Clark, Clay, Crawford, Jasper, Lawrence, Marion and 4 more	2 hr
Apr 18, 12:48 PM CDT	Mesoscale Discussion	SPC	Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more	87 min
Apr 18, 2:47 PM CDT	Mesoscale Discussion	SPC	Clark, Crawford, Lawrence	88 min

Nearby

Mesoscale Discussions in Illinois, 2013 Every mesoscale discussion in 2013

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.