Alert archive / Indiana / Mesoscale Discussions in 2011

Mesoscale Discussion 699

May 7, 20115 counties in Illinois; 27 counties in Indiana

The Storm Prediction Center issued this mesoscale discussion at May 7, 2011, 7:15 PM CDT for 5 counties in Illinois; 27 counties in Indiana. It was in force for 90 min.

The area

The outline as issued.

The facts

Issued
May 7, 2011, 7:15 PM CDT (00:15 UTC)
Expired
May 7, 2011, 8:45 PM CDT
In force
90 min
Issued by
the Storm Prediction Center
All 32 counties

Clark County, IL, Crawford County, IL, Edgar County, IL, Jasper County, IL, Lawrence County, IL, Bartholomew County, IN, Brown County, IN, Clay County, IN, Daviess County, IN, Decatur County, IN, Greene County, IN, Hendricks County, IN, Jackson County, IN, Jefferson County, IN, Jennings County, IN, Johnson County, IN, Knox County, IN, Lawrence County, IN, Marion County, IN, Martin County, IN, Monroe County, IN, Morgan County, IN, Orange County, IN, Owen County, IN, Parke County, IN, Putnam County, IN, Scott County, IN, Shelby County, IN, Sullivan County, IN, Vermillion County, IN, Vigo County, IN, Washington County, IN

The radar

The Indianapolis radar (KIND), 77 km from the middle of the area, began a volume at 00:17 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, 0.3 hours before the alert went out and 200 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 00:00Z on 2011-05-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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 00:00Z on 2011-05-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 52 square meters per square second.1939587897Sfc1 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
3086 m above ground
0-6 km bulk shear
56 kt
0-1 km storm-relative helicity
52 m²/s²
0-3 km storm-relative helicity
113 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.

575 
ACUS11 KWNS 080015
SWOMCD
SPC MCD 080015 
INZ000-KYZ000-ILZ000-080145-

MESOSCALE DISCUSSION 0699
NWS STORM PREDICTION CENTER NORMAN OK
0715 PM CDT SAT MAY 07 2011

AREAS AFFECTED...ERN IL...CNTRL AND SRN IND

CONCERNING...SEVERE THUNDERSTORM WATCH 264...

VALID 080015Z - 080145Z

THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 264
CONTINUES.

THE SEVERE THREAT CURRENTLY IN ERN IL AND WRN IND WILL MOVE SEWD
INTO SRN IND THIS EVENING. ALTHOUGH A BRIEF TORNADO WILL BE
POSSIBLE...LARGE HAIL AND WIND DAMAGE SHOULD BE THE PRIMARY THREATS.
WW ISSUANCE IS NOT EXPECTED DOWNSTREAM FROM WW 264 BUT A LOCAL
EXTENSION MAY BE REQUIRED LATER THIS EVENING.

A SMALL CLUSTER OF SEVERE STORMS IS ONGOING NEAR THE IL AND IND
STATE-LINE ON THE NERN END OF AN AXIS OF INSTABILITY WHERE
MESOANALYSIS ESTIMATES MLCAPE VALUES ARE 500 TO 1000 J/KG. THE
STORMS ARE BEING SUPPORTED BY A SHORTWAVE TROUGH AND AN ASSOCIATED
50 TO 60 KT MID-LEVEL JET. THE MID-LEVEL JET IS HELPING TO CREATE
STRONG DEEP LAYER SHEAR WITH WSR-88D VWP IN INDIANAPOLIS SHOWING 60
KT OF 0-6 KM SHEAR. THIS COMBINED WITH STEEP MID-LEVEL LAPSE RATES
SHOULD CONTINUE TO SUPPORT A THREAT FOR SUPERCELLS AND LARGE HAIL.
ISOLATED WIND DAMAGE MAY ALSO OCCUR ESPECIALLY AS THE STORMS BECOME
MORE LINEAR. HOWEVER...THE SEVERE THREAT SHOULD BECOME INCREASINGLY
ISOLATED AS INSTABILITY WEAKENS THIS EVENING.

..BROYLES.. 05/08/2011

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

ATTN...WFO...ILN...LMK...IND...PAH...ILX...

LAT...LON   38408699 38458589 38758531 39428532 39878624 39978730
            39698812 38918818 38408699

Nearby

Mesoscale Discussions in Indiana, 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.