Alert archive / Indiana / Mesoscale Discussions in 2016

Mesoscale Discussion 993

June 20, 201614 counties in Illinois; 36 counties in Indiana; 25 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Jun 20, 2016, 1:54 PM CDT for 14 counties in Illinois; 36 counties in Indiana; 25 counties in Ohio. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jun 20, 2016, 1:54 PM CDT (18:54 UTC)
Expired
Jun 20, 2016, 4:00 PM CDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 75 counties

Champaign County, IL, DeWitt County, IL, Douglas County, IL, Ford County, IL, Iroquois County, IL, Kankakee County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Mason County, IL, McLean County, IL, Piatt County, IL, Tazewell County, IL, Vermilion County, IL, Adams County, IN, Allen County, IN, Benton County, IN, Blackford County, IN, Boone County, IN, Carroll County, IN, Cass County, IN, Clinton County, IN, DeKalb County, IN, Delaware County, IN, Fountain County, IN, Fulton County, IN, Grant County, IN, Hamilton County, IN, Howard County, IN, Huntington County, IN, Jasper County, IN, Jay County, IN, Kosciusko County, IN, Madison County, IN, Marshall County, IN, Miami County, IN, Montgomery County, IN, Newton County, IN, Noble County, IN, Pulaski County, IN, Randolph County, IN, Starke County, IN, Tippecanoe County, IN, Tipton County, IN, Vermillion 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, Darke County, OH, Defiance County, OH, Erie County, OH, Hancock County, OH, Hardin County, OH, Henry County, OH, Huron County, OH, Logan County, OH, Marion County, OH, Mercer County, OH, Morrow County, OH, Paulding County, OH, Putnam County, OH, Richland County, OH, Sandusky County, OH, Seneca County, OH, Shelby County, OH, Union County, OH, Van Wert County, OH, Wood County, OH, Wyandot County, OH

The radar

The Northern Indiana radar (KIWX), 61 km from the middle of the area, began a volume at 18:57 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, 6.9 hours before the alert went out and 232 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 2016-06-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 225 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 2016-06-20The 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
225 J/kg
Mixed-layer CIN
-178 J/kg
Mixed-layer LCL
1180 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
51 m²/s²
0-3 km storm-relative helicity
146 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

415 
ACUS11 KWNS 201854
SWOMCD
SPC MCD 201854 
OHZ000-INZ000-ILZ000-202100-

MESOSCALE DISCUSSION 0993
NWS STORM PREDICTION CENTER NORMAN OK
0154 PM CDT MON JUN 20 2016

AREAS AFFECTED...PARTS OF N CNTRL ILLINOIS...NRN INDIANA...NWRN OHIO

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 201854Z - 202100Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THUNDERSTORM ACTIVITY MAY INCREASE THROUGH LATE
AFTERNOON...ACCOMPANIED BY AT LEAST SOME RISK FOR POTENTIALLY
DAMAGING WIND GUSTS.  IF ACTIVITY SHOWS SIGNS OF INCREASING UPSCALE
GROWTH/ORGANIZATION...THE ISSUANCE OF A SEVERE WEATHER WATCH IS
POSSIBLE.

DISCUSSION...WELL TO THE SOUTH OF A SIGNIFICANT SHORT WAVE TROUGH
PIVOTING ACROSS ONTARIO...TOWARD QUEBEC...A GRADUALLY STRENGTHENING
/30-50+ KT AT 500 MB/ AND VEERING /WESTERLY TO NORTHWESTERLY/ OF
MID-LEVEL FLOW IS UNDERWAY ACROSS SOUTHERN PORTIONS OF THE GREAT
LAKES REGION.  ALONG THE SOUTHERN/LEADING EDGE OF ASSOCIATED
MID-LEVEL COOLING...AN INCREASE IN THUNDERSTORM ACTIVITY IS ONGOING
NEAR/SOUTH OF THE MICHIGAN/INDIANA BORDER AREA INTO AREAS SOUTH AND
WEST OF THE CHICAGO METRO.  THIS FORCING AND ASSOCIATED CONVECTION
IS EXPECTED TO CONTINUE SLOWLY SHIFTING SOUTHWARD...WITH SUBSTANTIVE
FURTHER INTENSIFICATION OF CONVECTION POSSIBLE THROUGH 21-23Z. 
ALTHOUGH LOW-LEVEL CONVERGENCE ACROSS THIS REGION APPEARS GENERALLY
WEAK...LIFT ALONG CONSOLIDATING/STRENGTHENING CONVECTIVE COLD POOLS
AS THEY PROGRESS INTO AN AXIS OF STRONGER PRE-FRONTAL HEATING MAY
AID STORM DEVELOPMENT.  MIXED LAYER CAPE INCREASING TO 1500-2000+
J/KG...COUPLED WITH VERTICAL SHEAR INCREASINGLY FAVORABLE FOR
ORGANIZED CONVECTION...MAY SUPPORT AN INCREASING RISK FOR
POTENTIALLY DAMAGING WIND GUSTS THROUGH LATE AFTERNOON.

..KERR/GUYER.. 06/20/2016

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

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

LAT...LON   41428650 41538316 41298176 40328285 39668876 40159012
            41128856 41428650

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jun 20, 3:03 PM CDTSevere Thunderstorm WatchSPCChampaign, DeWitt, Douglas, Edgar, Ford, Iroquois and 5 more7 hr
Jun 20, 3:07 PM CDTMesoscale DiscussionSPCAdams, Brown, Fulton, Hancock, Henderson, Knox and 4 more83 min
Jun 20, 6:05 PM CDTMesoscale DiscussionSPCChampaign, DeWitt, Edgar, Ford, Iroquois, Livingston and 3 more85 min

Nearby

Mesoscale Discussions in Indiana, 2016Mesoscale Discussions in Ohio, 2016Mesoscale Discussions in Illinois, 2016Every mesoscale discussion in 2016

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.