Alert archive / Indiana / Mesoscale Discussions in 2016

Mesoscale Discussion 1349

July 21, 201619 counties in Indiana; 11 counties in Michigan; 15 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Jul 21, 2016, 2:23 PM EDT for 19 counties in Indiana; 11 counties in Michigan; 15 counties in Ohio. It was in force for 2 hr.

The area

The outline as issued.

The facts

Issued
Jul 21, 2016, 2:23 PM EDT (18:23 UTC)
Expired
Jul 21, 2016, 4:30 PM EDT
In force
2 hr
Issued by
the Storm Prediction Center
Chance of a watch
40%
All 45 counties

Allen County, IN, DeKalb County, IN, Elkhart County, IN, Fulton County, IN, Huntington County, IN, Jasper County, IN, Kosciusko County, IN, LaGrange County, IN, Lake County, IN, LaPorte County, IN, Marshall County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Steuben County, IN, Wabash County, IN, Whitley County, IN, Branch County, MI, Calhoun County, MI, Cass County, MI, Hillsdale County, MI, Jackson County, MI, Lenawee County, MI, Livingston County, MI, Monroe County, MI, Saint Joseph County, MI, Washtenaw County, MI, Wayne County, MI, Defiance County, OH, Erie County, OH, Fulton County, OH, Hancock County, OH, Henry County, OH, Huron County, OH, Lucas County, OH, Ottawa County, OH, Paulding County, OH, Putnam County, OH, Sandusky County, OH, Seneca County, OH, Van Wert County, OH, Williams County, OH, Wood County, OH

The radar

The Northern Indiana radar (KIWX), 81 km from the middle of the area, began a volume at 18:23 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

Detroit, MI (KDTX), launched 12:00Z, 6.4 hours before the alert went out and 168 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, Detroit, MI at 12:00Z on 2016-07-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 690 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, Detroit, MI at 12:00Z on 2016-07-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.193958Sfc1 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
690 J/kg
Mixed-layer CIN
-74 J/kg
Mixed-layer LCL
1014 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
26 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

293 
ACUS11 KWNS 211824
SWOMCD
SPC MCD 211823 
OHZ000-MIZ000-INZ000-ILZ000-212030-

MESOSCALE DISCUSSION 1349
NWS STORM PREDICTION CENTER NORMAN OK
0123 PM CDT THU JUL 21 2016

AREAS AFFECTED...EXTREME NERN IL...PORTIONS OF SRN LOWER MI...NRN
INDIANA...NWRN OH...ADJACENT LE

CONCERNING...SEVERE POTENTIAL...WATCH POSSIBLE 

VALID 211823Z - 212030Z

PROBABILITY OF WATCH ISSUANCE...40 PERCENT

SUMMARY...THUNDERSTORM COVERAGE IS EXPECTED TO INCREASE THIS
AFTERNOON WITH A RISK FOR ISOLATED DAMAGING WINDS AND PERHAPS LARGE
HAIL. IT REMAINS UNCLEAR WHETHER A WATCH WILL BE NEEDED...HOWEVER
THUNDERSTORM TRENDS WILL BE MONITORED.

DISCUSSION...THE LEADING EDGE OF A BROKEN LINE OF THUNDERSTORMS
CONTINUES TO MOVE SOUTHEAST AT 35 MPH ACROSS SOUTHWEST LOWER
MI/NORTHWEST INDIANA WITH SEVERAL CELLS DEVELOPING AHEAD OF THE LINE
IN THE VICINITY. DOWNSTREAM...STRONG HEATING OF UPPER 60S/LOWER 70S
SURFACE DEW POINTS HAS YIELDED MODERATE-STRONG SURFACE-BASED
INSTABILITY. ENVIRONMENTAL WIND FIELDS WITHIN THE DISCUSSION AREA
REMAIN MODEST AT BEST...AND THE LATEST KIWX VWP INDICATES AROUND 20
KTS OF DEEP-LAYER SHEAR. 

A PRONOUNCED COLD POOL ASSOCIATED WITH THE LONG-LIVED MCS CONTINUES
TO MOVE SOUTHEAST AND IS EXPECTED TO RESULT IN AN INCREASE IN
THUNDERSTORM COVERAGE DURING THE NEXT FEW HOURS AS IT ENCOUNTERS AN
UNCAPPED AIR MASS AS INDICATED BY A DEEPENING CUMULUS FIELD ON
VISIBLE IMAGERY. CLUSTERS OF STRONG/ISOLATED SEVERE STORMS WILL BE
POSSIBLE WITH SEVERE WINDS THE PRIMARY THREAT...THOUGH MARGINALLY
SEVERE HAIL WILL ALSO BE POSSIBLE WITH THE STRONGEST STORMS.

IT REMAINS UNCLEAR WHETHER A WATCH WILL BE NEEDED GIVEN CONCERNS
ABOUT THE OVERALL SEVERE COVERAGE...AND CONVECTIVE TRENDS WILL
CONTINUE TO BE MONITORED.

..BUNTING/HART.. 07/21/2016

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

ATTN...WFO...CLE...DTX...IWX...GRR...LOT...

LAT...LON   40778461 40818707 41348769 41768728 41798659 41998605
            42498469 42668376 42558311 41948323 41408255 41038258
            40888299 40778461

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 21, 7:18 PM EDTSevere Thunderstorm WatchSPCBenton, Jasper, Lake, Newton, Porter6 hr
Jul 21, 4:54 AM EDTMesoscale DiscussionSPCBaraga, Dickinson, Gogebic, Houghton, Iron, Keweenaw and 2 more2 hr
Jul 21, 5:31 AM EDTSevere Thunderstorm WatchSPCAlger, Baraga, Delta, Dickinson, Gogebic, Houghton and 7 more6 hr
Jul 21, 7:39 AM EDTMesoscale DiscussionSPCAlger, Baraga, Delta, Dickinson, Houghton, Iron and 3 more2 hr
Jul 21, 9:28 AM EDTMesoscale DiscussionSPCAlcona, Alpena, Antrim, Arenac, Bay, Benzie and 42 more2 hr
Jul 21, 9:45 AM EDTSevere Thunderstorm WatchSPCAlcona, Alpena, Antrim, Arenac, Bay, Benzie and 43 more7 hr
Jul 21, 12:19 PM EDTMesoscale DiscussionSPCAlcona, Alpena, Arenac, Bay, Cheboygan, Clare and 30 more116 min

Nearby

Mesoscale Discussions in Indiana, 2016Mesoscale Discussions in Ohio, 2016Mesoscale Discussions in Michigan, 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.