Alert archive / Indiana / Mesoscale Discussions in 2012

Mesoscale Discussion 1333

July 1, 201210 counties in Illinois; 40 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at Jul 1, 2012, 11:33 AM CDT for 10 counties in Illinois; 40 counties in Indiana. It was in force for 57 min.

The area

The outline as issued.

The facts

Issued
Jul 1, 2012, 11:33 AM CDT (16:33 UTC)
Expired
Jul 1, 2012, 12:30 PM CDT
In force
57 min
Issued by
the Storm Prediction Center
Chance of a watch
80%
All 50 counties

Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Iroquois County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, LaSalle County, IL, Will County, IL, Adams County, IN, Benton County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, Delaware County, IN, Fayette County, IN, Fountain County, IN, Fulton County, IN, Grant County, IN, Hamilton County, IN, Hancock County, IN, Hendricks County, IN, Henry County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Jay County, IN, Lake County, IN, Madison County, IN, Marion County, IN, Marshall County, IN, Miami County, IN, Montgomery County, IN, Newton County, IN, Porter County, IN, Pulaski County, IN, Randolph County, IN, Rush County, IN, Shelby County, IN, Starke County, IN, Tippecanoe County, IN, Tipton County, IN, Wabash County, IN, Warren County, IN, Wayne County, IN, Wells County, IN, White County, IN

The radar

The Indianapolis radar (KIND), 106 km from the middle of the area, began a volume at 16:35 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, 4.6 hours before the alert went out and 161 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 2012-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 2061 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 2012-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 51 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
2061 J/kg
Mixed-layer CIN
-149 J/kg
Mixed-layer LCL
1957 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
67 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.

879 
ACUS11 KWNS 011634
SWOMCD
SPC MCD 011633
OHZ000-INZ000-ILZ000-011730-

MESOSCALE DISCUSSION 1333
NWS STORM PREDICTION CENTER NORMAN OK
1133 AM CDT SUN JUL 01 2012

AREAS AFFECTED...PORTIONS OF NERN IL / CNTRL-NRN IND

CONCERNING...SEVERE POTENTIAL...SEVERE THUNDERSTORM WATCH LIKELY

VALID 011633Z - 011730Z

PROBABILITY OF WATCH ISSUANCE...80 PERCENT

SUMMARY...THE RISK FOR ISOLD LARGE HAIL AND SEVERE MICROBURSTS WILL
INCREASE AS STORM COVERAGE INCREASES THIS AFTERNOON.  SHORT TERM
TRENDS WILL BE MONITORED.

DISCUSSION...VISIBLE SATELLITE/RADAR MOSAIC OVER THE PAST FEW HOURS
HAS SHOWN A COLLAPSING TSTM COMPLEX INVOF THE IA/IL/MO BORDER.  A
GROWING AREA OF TSTMS OVER NERN IL MAY BE THE RESULT OF AN ARCING
GRAVITY WAVE INTERACTING WITH A FRONTAL ZONE DRAPED ACROSS THE
REGION.  12Z DVN/ILX RAOBS FEATURED STEEP MID LEVEL LAPSE RATES
AROUND 8 DEG C/KM.  AS THE BOUNDARY LAYER CONTINUES TO HEAT AND
DESTABILIZES FURTHER...UPWARDS OF 3000-4000 J/KG MLCAPE PER NAM
FORECAST SOUNDINGS WITHIN A BELT OF MODEST WLY-NWLY FLOW...ON THE
FRINGE OF A SRN MICH MID LEVEL SPEED MAX...WILL ACT TO SUPPORT
ORGANIZED SEVERE MULTICELLS CAPABLE OF ISOLD LARGE HAIL/SEVERE WIND
GUSTS.

..SMITH/THOMPSON.. 07/01/2012

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

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

LAT...LON   39568647 41328918 41988935 42028795 40788485 40028462
            39408541 39568647

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 12:16 PM CDTSevere Thunderstorm WatchSPCCook, DuPage, Iroquois, Kankakee, Will6 hr
Jul 1, 1:59 PM CDTMesoscale DiscussionSPCFranklin, Gallatin, Hamilton, Hardin, Jackson, Johnson and 7 more61 min
Jul 1, 2:56 PM CDTMesoscale DiscussionSPCAdams, Allen, Blackford, Cass, DeKalb, Delaware and 20 more94 min
Jul 1, 4:59 PM CDTSevere Thunderstorm WatchSPCClark, Crawford, Dearborn, Dubois, Floyd, Franklin and 9 more5 hr

Nearby

Mesoscale Discussions in Indiana, 2012Mesoscale Discussions in Illinois, 2012Every mesoscale discussion in 2012

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.