Alert archive / Indiana / Mesoscale Discussions in 2005

Mesoscale Discussion 821

May 11, 200510 counties in Illinois; 38 counties in Indiana; 9 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at May 11, 2005, 3:21 PM CDT for 10 counties in Illinois; 38 counties in Indiana; 9 counties in Ohio. It was in force for 114 min.

The area

The outline as issued.

The facts

Issued: May 11, 2005, 3:21 PM CDT (20:21 UTC)
Expired: May 11, 2005, 5:15 PM CDT
In force: 114 min
Issued by: the Storm Prediction Center

All 57 counties

Champaign County, IL, Clark County, IL, Coles County, IL, Cumberland County, IL, DeWitt County, IL, Douglas County, IL, Edgar County, IL, Moultrie County, IL, Piatt County, IL, Vermilion County, IL, Adams County, IN, Allen County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Clay County, IN, Clinton County, IN, Delaware County, IN, Fayette County, IN, Fountain County, IN, Grant County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jay County, IN, Johnson County, IN, Madison County, IN, Marion County, IN, Miami County, IN, Montgomery County, IN, Morgan County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Randolph County, IN, Rush County, IN, Shelby County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion County, IN, Vigo County, IN, Wabash County, IN, Warren County, IN, Wayne County, IN, Wells County, IN, Allen County, OH, Auglaize County, OH, Darke County, OH, Defiance County, OH, Henry County, OH, Mercer County, OH, Paulding County, OH, Putnam County, OH, Van Wert County, OH

The radar

The Indianapolis radar (KIND), 55 km from the middle of the area, began a volume at 20:22 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.

Severe Thunderstorm Watch 251May 11, 3:40 PM CDT

The nearest sounding before it

Lincoln, IL (KILX), launched 12:00Z, 8.4 hours before the alert went out and 190 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: 1689 J/kg
Mixed-layer CIN: -80 J/kg
Mixed-layer LCL: 1125 m above ground
0-6 km bulk shear: 39 kt
0-1 km storm-relative helicity: 148 m²/s²
0-3 km storm-relative helicity: 84 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

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

000 
ACUS11 KWNS 112021
SWOMCD
SPC MCD 112021 
OHZ000-INZ000-ILZ000-112215-

MESOSCALE DISCUSSION 0821
NWS STORM PREDICTION CENTER NORMAN OK
0321 PM CDT WED MAY 11 2005

AREAS AFFECTED...CENTRAL/WRN OH...CENTRAL IND...AND E-CENTRAL IL

CONCERNING...SEVERE THUNDERSTORM WATCH 246...

VALID 112021Z - 112215Z

WW 246 CONTINUES IN EFFECT ACROSS PORTIONS OF CENTRAL/WRN OH AND ERN
IND. ADDITIONAL THUNDERSTORMS ARE DEVELOPING WWD ACROSS MUCH OF
CENTRAL IND INTO E-CENTRAL IL. THESE STORMS POSE A SEVERE
THUNDERSTORM THREAT AND MAY NECESSITATE AN ADDITIONAL WATCH. 

AT 20Z...SCATTERED NEW THUNDERSTORM DEVELOPMENT IS OCCURRING NEAR A
PRE-FRONTAL TROUGH...EXTENDING FROM 10S FWA TO 20S LAF TO 30NE MTO.
AXIS OF HIGH BOUNDARY LAYER MOISTURE EXTENDS ALONG THIS BOUNDARY
/DEWPOINTS IN THE MID 60S/...CONTRIBUTING TO MLCAPE VALUES BETWEEN
2000-2500 J/KG. WITH THE SURFACE BOUNDARY ACTING AS A FOCUS...THESE
STORMS ARE EXPECTED TO CONTINUE FOR SEVERAL HOURS WHILE TRACKING
GENERALLY EWD AT 20-25 KT. DEEP-LAYER SHEAR RANGES FROM
30-35KT...WHICH SHOULD SUPPORT SOME LONG-LIVED...ORGANIZED STORMS
WITH SUPERCELL CHARACTERISTICS. LOW-LEVEL HODOGRAPH CURVATURE AND
SRH IS LIMITED...ALONG WITH LOW MAGNITUDE OF LOW-LEVEL WINDS.
THUS...PRIMARY THREAT WITH THESE CELLS IS EXPECTED TO BE LARGE HAIL
AND ISOLATED DAMAGING WINDS ASSOCIATED WITH CONVECTIVE DOWNDRAFTS. 

FURTHER EAST...ACROSS WW 246...ACTIVITY EXTENDING FROM NWRN OH INTO
E-CENTRAL IND WILL PROGRESS INTO THE WRN PORTION OF THE WATCH AREA
DURING THE NEXT 1-2 HOURS...WITH THREAT OF LARGE HAIL AND ISOLATED
DAMAGING WINDS. SEPARATE CLUSTER OF STORMS TRACKING ESEWD THROUGH
ERN OH HAVE GENERALLY REMAINED BELOW SEVERE LIMITS. LIMITED
INSTABILITY SHOULD KEEP SEVERE POTENTIAL ISOLATED ACROSS THE UPPER
OHIO RIVER VALLEY. LASTLY...NORTH WINDS FROM LAKE ERIE HAVE
EFFECTIVELY ELIMINATED SEVERE THREAT ACROSS NRN OHIO GIVEN COOL
BOUNDARY LAYER. MAIN SEVERE WEATHER POTENTIAL SHOULD BE ACROSS WRN
PORTION OF WATCH AREA NEXT 1-2 HOURS.

..BANACOS.. 05/11/2005

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

ATTN...WFO...ILN...IWX...IND...LOT...ILX...

40368765 40738625 41158521 41408461 41418401 41108396
40738392 40218441 39578524 39408624 39248693 39138772
39158808 39418862 39778884 40188895

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 11, 3:11 AM CDT	Mesoscale Discussion	SPC	Bureau, Henry, Lee, Marshall, Mercer, Rock Island and 2 more	2 hr
May 11, 8:41 AM CDT	Mesoscale Discussion	SPC	Adams, Hancock	2 hr
May 11, 1:37 PM CDT	Mesoscale Discussion	SPC	Adams, Brown, Calhoun, Cass, Christian, Coles and 22 more	113 min
May 11, 1:55 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Brown, Calhoun, Cass, Fulton, Greene and 11 more	6 hr
May 11, 6:28 PM CDT	Mesoscale Discussion	SPC	Christian, Clark, Clay, Coles, Crawford, Cumberland and 13 more	2 hr
May 11, 11:54 AM CDT	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Boone, Carroll, Cass and 28 more	2 hr
May 11, 12:25 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Blackford, Delaware, Fayette, Hancock, Henry and 9 more	7 hr
May 11, 3:40 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Bartholomew, Blackford, Boone, Brown, Clay and 33 more	5 hr

Nearby

Mesoscale Discussions in Indiana, 2005 Mesoscale Discussions in Illinois, 2005 Mesoscale Discussions in Ohio, 2005 Every mesoscale discussion in 2005

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.