Alert archive / Illinois / Mesoscale Discussions in 2017
Mesoscale Discussion 563
The Storm Prediction Center issued this mesoscale discussion at Apr 26, 2017, 3:53 PM CDT for 6 states. It was in force for 97 min.
The area
The outline as issued.
The facts
- Issued
- Apr 26, 2017, 3:53 PM CDT (20:53 UTC)
- Expired
- Apr 26, 2017, 5:30 PM CDT
- In force
- 97 min
- Issued by
- the Storm Prediction Center
All 46 counties
Clay County, AR, Alexander County, IL, Clark County, IL, Clay County, IL, Coles County, IL, Crawford County, IL, Cumberland County, IL, Edwards County, IL, Effingham County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jasper County, IL, Johnson County, IL, Lawrence County, IL, Massac County, IL, Pope County, IL, Pulaski County, IL, Richland County, IL, Saline County, IL, Wabash County, IL, Wayne County, IL, White County, IL, Clay County, IN, Gibson County, IN, Knox County, IN, Posey County, IN, Sullivan County, IN, Vigo County, IN, Ballard County, KY, Carlisle County, KY, Crittenden County, KY, Fulton County, KY, Hickman County, KY, Livingston County, KY, McCracken County, KY, Union County, KY, Butler County, MO, Dunklin County, MO, Mississippi County, MO, New Madrid County, MO, Pemiscot County, MO, Scott County, MO, Stoddard County, MO, Lake County, TN, Obion County, TN
The radar
The Paducah radar (KPAH), 59 km from the middle of the area, began a volume at 20:55 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
Nashville Metro, TN (KBNA), launched 12:00Z, 8.9 hours before the alert went out and 271 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
- 0 J/kg
- Mixed-layer CIN
- No buoyant parcel
- Mixed-layer LCL
- 1165 m above ground
- 0-6 km bulk shear
- 21 kt
- 0-1 km storm-relative helicity
- 138 m²/s²
- 0-3 km storm-relative helicity
- 114 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
364
ACUS11 KWNS 262054
SWOMCD
SPC MCD 262053
INZ000-KYZ000-ILZ000-TNZ000-MOZ000-ARZ000-262230-
Mesoscale Discussion 0563
NWS Storm Prediction Center Norman OK
0353 PM CDT Wed Apr 26 2017
Areas affected...Southern IL...Southwest IN...Western KY...Southeast
MO...Extreme Northeast AR/Northwest TN
Concerning...Severe Thunderstorm Watch 163...
Valid 262053Z - 262230Z
The severe weather threat for Severe Thunderstorm Watch 163
continues.
SUMMARY...An intense thunderstorm cluster will continue to produce
potentially damaging winds across southeast IL, perhaps extending
into western IN. Another cluster may intensify across southeast MO
into western KY.
DISCUSSION...At 2045Z, an intense bowing segment was moving quickly
northeastward across southeast IL. Temperatures have warmed into the
80s F ahead of this feature, and a combination of moderate
instability, sufficient effective shear, and steep low-level lapse
rates will continue to support a threat of damaging wind with this
system. Another weaker line segment was approaching the MO Bootheel
from northeast AR. Some intensification of this line is possible as
it moves across far southeast MO in the next 1-2 hours, with a
primary threat of damaging wind.
With time, at least some severe threat will spread eastward out of
WW 163, into portions of Indiana, western KY, and northwest TN.
Downstream watch issuance is considered possible at this time,
though it will depend on short-term convective trends in the next
1-2 hours.
..Dean/Hart.. 04/26/2017
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...IND...PAH...ILX...MEG...LSX...
LAT...LON 36999033 37208931 37748871 38838894 39218879 39628814
39618701 38288754 37368800 36648877 36008951 35988999
36019027 36589061 36999033SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 10:51 PM CDT | Mesoscale Discussion | SPC | Benton, Boone, Carroll, Madison, Washington | 54 min |
| Apr 25, 11:27 PM CDT | Severe Thunderstorm Watch | SPC | Benton, Carroll, Crawford, Franklin, Madison, Sebastian and 1 more | 7 hr |
| Apr 26, 1:42 AM CDT | Mesoscale Discussion | SPC | Baxter, Boone, Carroll, Crawford, Franklin, Johnson and 10 more | 2 hr |
| Apr 26, 5:37 AM CDT | Mesoscale Discussion | SPC | Conway, Crawford, Franklin, Garland, Howard, Johnson and 14 more | 113 min |
| Apr 26, 6:00 AM CDT | Severe Thunderstorm Watch | SPC | Baxter, Boone, Carroll, Conway, Crawford, Franklin and 23 more | 7 hr |
| Apr 26, 7:29 AM CDT | Mesoscale Discussion | SPC | Baxter, Boone, Carroll, Conway, Crawford, Franklin and 23 more | 2 hr |
| Apr 26, 9:39 AM CDT | Mesoscale Discussion | SPC | Arkansas, Baxter, Bradley, Calhoun, Clark, Clay and 47 more | 36 min |
| Apr 26, 10:08 AM CDT | Tornado Watch | SPC | Arkansas, Baxter, Bradley, Calhoun, Clark, Clay and 51 more | 7 hr |
| Apr 26, 1:05 PM CDT | Mesoscale Discussion | SPC | Clark, Columbia, Dallas, Grant, Hempstead, Hot Spring and 9 more | 85 min |
| Apr 26, 4:23 PM CDT | Mesoscale Discussion | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 19 more | 67 min |
| Apr 26, 4:44 PM CDT | Tornado Watch | SPC | Arkansas, Ashley, Bradley, Calhoun, Chicot, Cleveland and 11 more | 5 hr |
| Apr 26, 5:02 PM CDT | Severe Thunderstorm Watch | SPC | Clay, Craighead, Crittenden, Cross, Greene, Lee and 4 more | 6 hr |
| Apr 26, 6:10 PM CDT | Mesoscale Discussion | SPC | Mississippi | 95 min |
| Apr 26, 12:26 PM CDT | Mesoscale Discussion | SPC | Alexander, Clay, Clinton, Edwards, Franklin, Hamilton and 16 more | 94 min |
| Apr 26, 12:46 PM CDT | Severe Thunderstorm Watch | SPC | Alexander, Bond, Clark, Clay, Clinton, Crawford and 19 more | 6 hr |
| Apr 26, 4:58 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Allen, Blackford, Boone, Carroll, Cass and 43 more | 4 hr |
| Apr 25, 7:14 PM CDT | Mesoscale Discussion | SPC | McDonald | 91 min |
Nearby
Mesoscale Discussions in Illinois, 2017Mesoscale Discussions in Kentucky, 2017Mesoscale Discussions in Missouri, 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; radar from the NEXRAD Level II archive.