Alert archive / Indiana / Mesoscale Discussions in 2017
Mesoscale Discussion 231
The Storm Prediction Center issued this mesoscale discussion at Feb 28, 2017, 11:52 PM CST for 4 counties in Illinois; 13 counties in Indiana; 4 counties in Michigan. It was in force for 53 min.
The area
The outline as issued.
The facts
- Issued
- Feb 28, 2017, 11:52 PM CST (05:52 UTC)
- Expired
- Mar 1, 2017, 12:45 AM CST
- In force
- 53 min
- Issued by
- the Storm Prediction Center
All 21 counties
Champaign County, IL, Ford County, IL, Iroquois County, IL, Vermilion County, IL, Benton County, IN, Elkhart County, IN, Fulton County, IN, Jasper County, IN, LaPorte County, IN, Marshall County, IN, Newton County, IN, Porter County, IN, Pulaski County, IN, Saint Joseph County, IN, Starke County, IN, Warren County, IN, White County, IN, Berrien County, MI, Cass County, MI, Kalamazoo County, MI, Saint Joseph County, MI
The nearest sounding before it
Lincoln, IL (KILX), launched 00:00Z, 5.9 hours before the alert went out and 160 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.
- Mixed-layer CAPE
- 687 J/kg
- Mixed-layer CIN
- -73 J/kg
- Mixed-layer LCL
- 887 m above ground
- 0-6 km bulk shear
- 72 kt
- 0-1 km storm-relative helicity
- 395 m²/s²
- 0-3 km storm-relative helicity
- 431 m²/s²
- Significant tornado parameter
- 1.6
- Supercell composite
- 6.7
The text
As transmitted.
976
ACUS11 KWNS 010552
SWOMCD
SPC MCD 010552
MIZ000-INZ000-ILZ000-010645-
Mesoscale Discussion 0231
NWS Storm Prediction Center Norman OK
1152 PM CST Tue Feb 28 2017
Areas affected...Portions of eastern Illinois...northern
Indiana...and southwestern Lower Michigan
Concerning...Tornado Watch 48...49...
Valid 010552Z - 010645Z
The severe weather threat for Tornado Watch 48, 49 continues.
SUMMARY...A line of strong to severe thunderstorms will shift
eastward into northern Indiana and southern Lower Michigan through
the early overnight. Occasional strong gusts, marginally severe
hail, and perhaps a tornado or two will be possible as these storms
progress from Watch 48 into Watch 49.
DISCUSSION...Regional WSR-88D data depict a line of strong/severe
storms stretching from central Illinois northeastward to southern
Lake Michigan. The strongest portion of the line appears to be
pushing into northwestern Indiana and southwestern Lower Michigan in
the form of a bowing segment. While surface temperatures and dew
points have decreased ahead of this line, resulting in increasing
convective inhibition, strong west/southwesterly flow in low/mid
levels (as depicted by the KIWX VWP) will favor occasional bowing
structures with enough momentum to create gusty surface winds,
despite weak low-level stability. Therefore, occasional strong-wind
gusts and a tornado or two from an embedded circulation will be
possible through the early overnight.
..Picca.. 03/01/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...IWX...GRR...IND...LOT...ILX...
LAT...LON 40308856 41418740 42198669 42418563 42178489 41258587
40258713 40088809 40188837 40308856SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Feb 28, 7:46 PM CST | Mesoscale Discussion | SPC | Alexander, Clay, Crawford, Edwards, Franklin, Gallatin and 21 more | 119 min |
| Feb 28, 8:06 PM CST | Mesoscale Discussion | SPC | Adams, Brown, Bureau, Cass, Champaign, Christian and 37 more | 84 min |
| Feb 28, 8:29 PM CST | Tornado Watch | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more | 12 hr |
| Feb 28, 9:04 PM CST | Tornado Watch | SPC | Adams, Bond, Brown, Calhoun, Clinton, Fayette and 11 more | 7 hr |
| Feb 28, 9:51 PM CST | Tornado Watch | SPC | Cass, Champaign, Christian, Clark, Clay, Coles and 37 more | 6 hr |
| Feb 28, 10:09 PM CST | Mesoscale Discussion | SPC | Edwards, Franklin, Gallatin, Hamilton, Jackson, Johnson and 5 more | 66 min |
| Mar 1, 2:09 AM CST | Mesoscale Discussion | SPC | Alexander, Franklin, Gallatin, Hamilton, Hardin, Jackson and 8 more | 2 hr |
| Mar 1, 3:03 AM CST | Tornado Watch | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 13 more | 5 hr |
| Mar 1, 4:19 AM CST | Mesoscale Discussion | SPC | Alexander, Gallatin, Hardin, Johnson, Massac, Pope and 3 more | 56 min |
| Feb 28, 6:00 PM CST | Mesoscale Discussion | SPC | Adams, Allen, Cass, DeKalb, Elkhart, Fulton and 14 more | 90 min |
| Feb 28, 6:37 PM CST | Severe Thunderstorm Watch | SPC | Allen, DeKalb, Elkhart, Fulton, Kosciusko, LaGrange and 8 more | 8 hr |
| Feb 28, 8:41 PM CST | Mesoscale Discussion | SPC | Allen, DeKalb, Elkhart, Fulton, Kosciusko, LaGrange and 9 more | 94 min |
| Feb 28, 10:03 PM CST | Mesoscale Discussion | SPC | Adams, Allen, Bartholomew, Blackford, Boone, Carroll and 48 more | 117 min |
| Feb 28, 10:29 PM CST | Tornado Watch | SPC | Adams, Allen, Blackford, Boone, Carroll, Cass and 41 more | 8 hr |
| Mar 1, 12:44 AM CST | Mesoscale Discussion | SPC | Adams, Allen, Blackford, Boone, Carroll, Cass and 28 more | 61 min |
| Mar 1, 1:32 AM CST | Mesoscale Discussion | SPC | Clark, Crawford, Dearborn, Dubois, Floyd, Harrison and 11 more | 88 min |
| Mar 1, 4:57 AM CST | Tornado Watch | SPC | Clark, Crawford, Dearborn, Dubois, Floyd, Franklin and 9 more | 5 hr |
Nearby
Mesoscale Discussions in Indiana, 2017Mesoscale Discussions in Illinois, 2017Mesoscale Discussions in Michigan, 2017Every 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.