Alert archive / Illinois / Mesoscale Discussions in 2018
Mesoscale Discussion 413
The Storm Prediction Center issued this mesoscale discussion at May 14, 2018, 2:37 PM CDT for 38 counties in Illinois. It was in force for 53 min.
The area
The outline as issued.
The facts
- Issued
- May 14, 2018, 2:37 PM CDT (19:37 UTC)
- Expired
- May 14, 2018, 3:30 PM CDT
- In force
- 53 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 95%
All 38 counties
Adams County, IL, Brown County, IL, Bureau County, IL, Cass County, IL, Champaign County, IL, DeWitt County, IL, DuPage County, IL, Ford County, IL, Fulton County, IL, Greene County, IL, Grundy County, IL, Henry County, IL, Iroquois County, IL, Kankakee County, IL, Kendall County, IL, Knox County, IL, LaSalle County, IL, Livingston County, IL, Logan County, IL, Macon County, IL, Marshall County, IL, Mason County, IL, McDonough County, IL, McLean County, IL, Menard County, IL, Morgan County, IL, Peoria County, IL, Piatt County, IL, Pike County, IL, Putnam County, IL, Sangamon County, IL, Schuyler County, IL, Scott County, IL, Stark County, IL, Tazewell County, IL, Warren County, IL, Will County, IL, Woodford County, IL
The radar
The Lincoln radar (KILX), 40 km from the middle of the area, began a volume at 19:35 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
Lincoln, IL (KILX), launched 12:00Z, 7.6 hours before the alert went out and 95 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
- 962 J/kg
- Mixed-layer CIN
- -160 J/kg
- Mixed-layer LCL
- 1462 m above ground
- 0-6 km bulk shear
- 31 kt
- 0-1 km storm-relative helicity
- -23 m²/s²
- 0-3 km storm-relative helicity
- 86 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
766
ACUS11 KWNS 141937
SWOMCD
SPC MCD 141937
ILZ000-MOZ000-142030-
Mesoscale Discussion 0413
NWS Storm Prediction Center Norman OK
0237 PM CDT Mon May 14 2018
Areas affected...central/northern IL
Concerning...Severe potential...Severe Thunderstorm Watch likely
Valid 141937Z - 142030Z
Probability of Watch Issuance...95 percent
SUMMARY...Severe thunderstorms are expected to develop across the
discussion area the remainder of this afternoon with a risk for
large hail and damaging winds. A Severe Thunderstorm Watch will be
issued prior to 20Z.
DISCUSSION...Latest visible imagery shows deepening cumulus in the
vicinity of the front over central/northern IL at 1935Z, and
modification of the special KDVN sounding for current conditions
shows little remaining CINH. Thunderstorms are expected to develop
and will likely become severe over the next few hours given an
environment characterized by moderate surface-based instability and
40-45 kts of deep-layer wind shear. Damaging winds and large hail
will be possible, and a Severe Thunderstorm Watch will be issued
prior to 20Z.
..Bunting/Grams.. 05/14/2018
...Please see www.spc.noaa.gov for graphic product...
ATTN...WFO...LOT...ILX...LSX...DVN...
LAT...LON 39369011 39329084 39699108 40119126 40459113 41069067
41578989 41938861 41978777 40568766 40098782 39808872
39369011SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 14, 2:40 AM CDT | Mesoscale Discussion | SPC | Boone, Carroll, Cook, DeKalb, DuPage, Jo Daviess and 6 more | 2 hr |
| May 14, 2:54 PM CDT | Severe Thunderstorm Watch | SPC | Adams, Bond, Boone, Brown, Bureau, Calhoun and 59 more | 6 hr |
| May 14, 6:36 PM CDT | Mesoscale Discussion | SPC | Bond, Calhoun, Cass, Champaign, Christian, Clinton and 36 more | 84 min |
Nearby
Mesoscale Discussions in Illinois, 2018Every mesoscale discussion in 2018
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.