Alert archive / Ohio / Mesoscale Discussions in 2021

Mesoscale Discussion 1386

July 29, 202112 counties in Indiana; Hillsdale County, Lenawee County, Monroe County, Michigan; 19 counties in Ohio

The Storm Prediction Center issued this mesoscale discussion at Jul 29, 2021, 5:55 AM EDT for 12 counties in Indiana; Hillsdale County, Lenawee County, Monroe County, Michigan; 19 counties in Ohio. It was in force for 95 min.

The area

The outline as issued.

The facts

Issued
Jul 29, 2021, 5:55 AM EDT (09:55 UTC)
Expired
Jul 29, 2021, 7:30 AM EDT
In force
95 min
Issued by
the Storm Prediction Center
Concerning
Severe thunderstorm watch 400
All 34 counties

Adams County, IN, Allen County, IN, Blackford County, IN, DeKalb County, IN, Grant County, IN, Huntington County, IN, Jay County, IN, Miami County, IN, Steuben County, IN, Wabash County, IN, Wells County, IN, Whitley County, IN, Hillsdale County, MI, Lenawee County, MI, Monroe County, MI, Allen County, OH, Auglaize County, OH, Defiance County, OH, Fulton County, OH, Hancock County, OH, Hardin County, OH, Henry County, OH, Logan County, OH, Lucas County, OH, Mercer County, OH, Paulding County, OH, Putnam County, OH, Sandusky County, OH, Seneca County, OH, Shelby County, OH, Van Wert County, OH, Williams County, OH, Wood County, OH, Wyandot County, OH

The radar

The Northern Indiana radar (KIWX), 87 km from the middle of the area, began a volume at 09:53 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

Cncnati-Daytn, OH (KILN), launched 00:00Z, 9.9 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, Cncnati-Daytn, OH at 00:00Z on 2021-07-29Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1533 joules per kilogram.LCLEL10008507005003002001001 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, Cncnati-Daytn, OH at 00:00Z on 2021-07-29The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 41 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
1533 J/kg
Mixed-layer CIN
-3 J/kg
Mixed-layer LCL
1165 m above ground
0-6 km bulk shear
34 kt
0-1 km storm-relative helicity
41 m²/s²
0-3 km storm-relative helicity
100 m²/s²
Significant tornado parameter
0.4
Supercell composite
3.4

Open this sounding in Storm Lab

The text

As transmitted.

400 
ACUS11 KWNS 290955
SWOMCD
SPC MCD 290955 
OHZ000-MIZ000-INZ000-291130-

Mesoscale Discussion 1386
NWS Storm Prediction Center Norman OK
0455 AM CDT Thu Jul 29 2021

Areas affected...Portions of northeastern IN...northwestern OH...and
far southern Lower MI

Concerning...Severe Thunderstorm Watch 400...

Valid 290955Z - 291130Z

The severe weather threat for Severe Thunderstorm Watch 400
continues.

SUMMARY...An isolated wind threat continues in the short term.
Downstream watch issuance this morning is not currently expected.

DISCUSSION...The northeastern segment of an MCS has persisted early
this morning across parts of northern IN. A measured wind gust to 65
mph associated with this MCS was recorded at 0915Z at the Goshen
Airport ASOS. Based on recent velocity data from the KIWX radar, a
continued threat for isolated strong to severe winds should continue
in the short term across portions of northeastern IN. The airmass is
less unstable downstream into northwestern OH and far southeastern
Lower MI per recent mesoanalysis estimates, with MLCAPE generally
500-1000 J/kg. While a threat for occasional strong/gusty winds may
continue with this small cluster across northwestern OH and
vicinity, the overall severe threat appears rather isolated.
Therefore, downstream watch issuance this morning is unlikely at
this time.

..Gleason.. 07/29/2021

...Please see www.spc.noaa.gov for graphic product...

ATTN...WFO...CLE...ILN...DTX...IWX...IND...

LAT...LON   40798622 41408525 41908512 42018468 42028315 41078302
            40388344 40148449 40298574 40798622

SPC that day

Everything else SPC issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 29, 1:32 AM EDTMesoscale DiscussionSPCElkhart, Fulton, Jasper, Kosciusko, LaGrange, Lake and 7 more88 min
Jul 29, 2:00 AM EDTSevere Thunderstorm WatchSPCAdams, Allen, Benton, Cass, DeKalb, Elkhart and 20 more5 hr
Jul 29, 4:18 AM EDTMesoscale DiscussionSPCElkhart, Fulton, Jasper, Kosciusko, LaGrange, Lake and 7 more87 min
Jul 29, 3:13 PM EDTSevere Thunderstorm WatchSPCDearborn, Fayette, Franklin, Ohio, Ripley, Switzerland and 2 more7 hr
Jul 29, 3:19 PM EDTMesoscale DiscussionSPCBoone, Brown, Clay, Fountain, Greene, Hamilton and 17 more116 min
Jul 29, 6:34 PM EDTMesoscale DiscussionSPCDearborn, Fayette, Franklin, Henry, Rush, Union and 1 more116 min
Jul 29, 2:48 PM EDTMesoscale DiscussionSPCAdams, Athens, Brown, Butler, Champaign, Clark and 35 more117 min

Nearby

Mesoscale Discussions in Ohio, 2021Mesoscale Discussions in Indiana, 2021Mesoscale Discussions in Michigan, 2021Every mesoscale discussion in 2021

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.