Alert archive / Indiana / Mesoscale Discussions in 2011

Mesoscale Discussion 928

May 24, 20114 states

The Storm Prediction Center issued this mesoscale discussion at May 24, 2011, 1:11 PM CDT for 4 states. It was in force for 94 min.

The area

The outline as issued.

The facts

Issued
May 24, 2011, 1:11 PM CDT (18:11 UTC)
Expired
May 24, 2011, 2:45 PM CDT
In force
94 min
Issued by
the Storm Prediction Center
All 73 counties

Buchanan County, IA, Cedar County, IA, Clinton County, IA, Jackson County, IA, Johnson County, IA, Jones County, IA, Linn County, IA, Muscatine County, IA, Scott County, IA, Bureau County, IL, Ford County, IL, Grundy County, IL, Henry County, IL, Iroquois County, IL, Kankakee County, IL, Knox County, IL, LaSalle County, IL, Livingston County, IL, Marshall County, IL, McLean County, IL, Mercer County, IL, Peoria County, IL, Putnam County, IL, Rock Island County, IL, Stark County, IL, Whiteside County, IL, Woodford County, IL, Adams County, IN, Allen County, IN, Benton County, IN, Blackford County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, Fulton County, IN, Grant County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Jay County, IN, Miami County, IN, Newton County, IN, Pulaski County, IN, Tippecanoe County, IN, Tipton County, IN, Wabash County, IN, Warren County, IN, Wells County, IN, White County, IN, Whitley County, IN, Allen County, OH, Ashland County, OH, Auglaize County, OH, Crawford County, OH, Hancock County, OH, Hardin County, OH, Huron County, OH, Logan County, OH, Marion County, OH, Medina County, OH, Mercer County, OH, Morrow County, OH, Paulding County, OH, Portage County, OH, Putnam County, OH, Richland County, OH, Seneca County, OH, Shelby County, OH, Stark County, OH, Summit County, OH, Van Wert County, OH, Wayne County, OH, Wyandot County, OH

The radar

The Chicago radar (KLOT), 74 km from the middle of the area, began a volume at 18:10 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 12:00Z, 6.2 hours before the alert went out and 176 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, Lincoln, IL at 12:00Z on 2011-05-24Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 518 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, Lincoln, IL at 12:00Z on 2011-05-24The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -14 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
518 J/kg
Mixed-layer CIN
-69 J/kg
Mixed-layer LCL
941 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
-14 m²/s²
0-3 km storm-relative helicity
47 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.2

Open this sounding in Storm Lab

The text

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

290 
ACUS11 KWNS 241811
SWOMCD
SPC MCD 241811 
OHZ000-INZ000-ILZ000-IAZ000-241945-

MESOSCALE DISCUSSION 0928
NWS STORM PREDICTION CENTER NORMAN OK
0111 PM CDT TUE MAY 24 2011

AREAS AFFECTED...ERN IA...NRN IL/IND/OH

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 241811Z - 241945Z

AN ISOLATED THREAT FOR SEVERE HAIL/WIND IS EXPECTED THIS AFTERNOON
AS ISOLATED TO SCATTERED TSTMS DEVELOP ALONG A QUASI-STATIONARY
FRONT. THE NEED FOR ONE OR MORE SEVERE TSTM WATCHES REMAINS UNCLEAR
ATTM...WITH THE PROBABILITY OF A WW ISSUANCE BY 20Z AROUND 40
PERCENT.

INCIPIENT TSTM DEVELOPMENT APPEARS TO BE UNDERWAY AS TCU/SMALL CB
HAVE DEEPENED ALONG A QUASI-STATIONARY FRONT THAT STRETCHES FROM
E-CNTRL IOWA ACROSS NRN IL/IND/OH. DESPITE WEAK LOW-LEVEL
CONVERGENCE...OPERATIONAL AND CONVECTION-ALLOWING MODEL GUIDANCE ARE
ADAMANT THAT TSTM COVERAGE WILL INCREASE THROUGH THE AFTERNOON.
ROBUST HEATING WILL CONTINUE S OF THE FRONTAL AXIS...RESULTING IN A
MODERATELY UNSTABLE AIR MASS WITH MLCAPE OF 1000 TO 2000 J/KG. EVEN
WITH WEAK LOW-LEVEL FLOW...20 TO 30 KT WLYS AT 3 TO 6 KM AGL SAMPLED
IN WINCHESTER IL AND SLATER IA PROFILERS WILL BE MARGINALLY
SUFFICIENT FOR ORGANIZED UPDRAFTS. OVERALL SETUP SHOULD YIELD
ISOLATED SEVERE HAIL/WIND REPORTS THROUGH THE AFTERNOON.

..GRAMS.. 05/24/2011

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

ATTN...WFO...CLE...ILN...IWX...IND...LOT...ILX...DVN...ARX...
DMX...

LAT...LON   41259132 42419228 42699220 42709188 42339108 42069020
            41418881 41218683 41278435 41518093 41258086 40858121
            40678170 40428262 40228459 40308807 40829043 41259132

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
May 24, 1:38 PM CDTSevere Thunderstorm WatchSPCAdams, Brown, Calhoun, Greene, Jersey, Macoupin and 4 more5 hr
May 24, 4:55 PM CDTMesoscale DiscussionSPCAdams, Brown, Calhoun, Greene, Jersey, Macoupin and 5 more65 min
May 23, 7:07 PM CDTMesoscale DiscussionSPCAshtabula, Carroll, Columbiana, Cuyahoga, Geauga, Holmes and 9 more83 min
May 23, 7:31 PM CDTSevere Thunderstorm WatchSPCAshtabula, Athens, Belmont, Carroll, Columbiana, Coshocton and 24 more3 hr

Nearby

Mesoscale Discussions in Indiana, 2011Mesoscale Discussions in Ohio, 2011Mesoscale Discussions in Illinois, 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.