Alert archive / Indiana / Mesoscale Discussions in 2017

Mesoscale Discussion 899

May 28, 20174 states

The Storm Prediction Center issued this mesoscale discussion at May 28, 2017, 12:16 PM CDT for 4 states. It was in force for 119 min.

The area

The outline as issued.

The facts

Issued: May 28, 2017, 12:16 PM CDT (17:16 UTC)
Expired: May 28, 2017, 2:15 PM CDT
In force: 119 min
Issued by: the Storm Prediction Center
Chance of a watch: 40%

All 88 counties

Champaign County, IL, Douglas County, IL, Ford County, IL, Iroquois 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, Elkhart 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, LaGrange County, IN, LaPorte County, IN, Madison County, IN, Marshall County, IN, Miami County, IN, Montgomery County, IN, Newton County, IN, Noble County, IN, Porter County, IN, Pulaski County, IN, Randolph County, IN, Saint Joseph County, IN, Starke County, IN, Steuben 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, Barry County, MI, Berrien County, MI, Branch County, MI, Calhoun County, MI, Cass County, MI, Eaton County, MI, Hillsdale County, MI, Ingham County, MI, Jackson County, MI, Kalamazoo County, MI, Lenawee County, MI, Monroe County, MI, Saint Joseph County, MI, Van Buren County, MI, Washtenaw County, MI, Allen County, OH, Auglaize County, OH, Crawford County, OH, Defiance County, OH, Fulton County, OH, Hancock County, OH, Hardin County, OH, Henry County, OH, Huron County, OH, Logan County, OH, Lucas County, OH, Marion County, OH, Mercer County, OH, Morrow County, OH, Ottawa 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, Williams County, OH, Wood County, OH, Wyandot County, OH

The radar

The Northern Indiana radar (KIWX), 45 km from the middle of the area, began a volume at 17:18 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.

Severe Thunderstorm Watch 292May 28, 12:55 PM CDT

The nearest sounding before it

Detroit, MI (KDTX), launched 12:00Z, 5.3 hours before the alert went out and 223 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 1059 m above ground
0-6 km bulk shear: 34 kt
0-1 km storm-relative helicity: 0 m²/s²
0-3 km storm-relative helicity: 52 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

232 
ACUS11 KWNS 281717
SWOMCD
SPC MCD 281716 
OHZ000-MIZ000-INZ000-ILZ000-281915-

Mesoscale Discussion 0899
NWS Storm Prediction Center Norman OK
1216 PM CDT Sun May 28 2017

Areas affected...Southern Lower Michigan...northwestern
Ohio...northern/central Indiana...and east-central Illinois

Concerning...Severe potential...Watch possible 

Valid 281716Z - 281915Z

Probability of Watch Issuance...40 percent

SUMMARY...Convection is expected to gradually increase in intensity
and coverage over the discussion area this afternoon, with damaging
wind gusts and hail being the primary threats.  A WW issuance will
be considered within the next couple of hours.

DISCUSSION...Latest radar/satellite imagery and objective analyses
indicate increasing convection in northwestern Indiana and adjacent
east-central Illinois within a broadly confluent, weak-to-moderately
(500-1250 J/kg) unstable, and uncapped airmass over the past hour. 
A subjectively analyzed surface trough/warm front was located near
the Michigan/Indiana/Ohio state borders and was slowly lifting north
across the region, with more veered surface flow amidst low to
mid-60s dewpoints to its south.  Over time, continued surface-based
destabilization and lift ahead of an approaching mid-level trough
near the Mississippi River will allow for storms to increase in
coverage and intensity.  Low-level shear profiles are weak, but deep
shear will be sufficient for storm organization, with wind gusts and
hail possible near stronger cores and any linear segments that can
evolve.  A brief tornado cannot be completely ruled out especially
near the warm front, where surface winds are backed.  Convective
trends will be monitored for a possible severe thunderstorm watch
issuance within the next couple of hours.

..Cook.. 05/28/2017

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

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

LAT...LON   42668599 42758502 42538384 42238330 42018326 41718318
            41508280 41218254 40818250 40468266 40278325 40148466
            39928593 39768756 39628826 39948858 40558837 41318768
            41568702 41758678 42668599

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 28, 3:09 PM CDT	Mesoscale Discussion	SPC	Edgar	66 min
May 28, 12:56 PM CDT	Severe Thunderstorm Watch	SPC	Adams, Allen, Blackford, Cass, DeKalb, Elkhart and 17 more	6 hr
May 28, 4:46 PM CDT	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Boone, Clinton, DeKalb and 12 more	59 min
May 28, 6:39 PM CDT	Mesoscale Discussion	SPC	Adams, Blackford, Boone, Carroll, Clinton, Delaware and 15 more	96 min
May 28, 11:54 AM CDT	Mesoscale Discussion	SPC	Alpena, Antrim, Cheboygan, Clare, Crawford, Emmet and 11 more	66 min
May 27, 7:07 PM CDT	Mesoscale Discussion	SPC	Adams, Athens, Gallia, Jackson, Lawrence, Meigs and 4 more	83 min

Nearby

Mesoscale Discussions in Indiana, 2017 Mesoscale Discussions in Ohio, 2017 Mesoscale Discussions in Michigan, 2017 Every mesoscale discussion in 2017

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.