Alert archive / Illinois / Mesoscale Discussions in 2016
Mesoscale Discussion 446
The Storm Prediction Center issued this mesoscale discussion at Apr 25, 2016, 6:04 PM CDT for 19 counties in Illinois; Lake County, Porter County, Indiana; 8 counties in Wisconsin. It was in force for 86 min.
The area
The outline as issued.
The facts
- Issued
- Apr 25, 2016, 6:04 PM CDT (23:04 UTC)
- Expired
- Apr 25, 2016, 7:30 PM CDT
- In force
- 86 min
- Issued by
- the Storm Prediction Center
All 29 counties
Boone County, IL, Bureau County, IL, Cook County, IL, DeKalb County, IL, DuPage County, IL, Grundy County, IL, Kane County, IL, Kankakee County, IL, Kendall County, IL, Lake County, IL, LaSalle County, IL, Lee County, IL, Marshall County, IL, McHenry County, IL, Ogle County, IL, Putnam County, IL, Stark County, IL, Will County, IL, Winnebago County, IL, Lake County, IN, Porter County, IN, Kenosha County, WI, Milwaukee County, WI, Ozaukee County, WI, Racine County, WI, Sheboygan County, WI, Walworth County, WI, Washington County, WI, Waukesha County, WI
The radar
The Chicago radar (KLOT), 77 km from the middle of the area, began a volume at 23:04 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
Davenport, (KDVN), launched 12:00Z, 11.1 hours before the alert went out and 154 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
- 1427 m above ground
- 0-6 km bulk shear
- 35 kt
- 0-1 km storm-relative helicity
- 182 m²/s²
- 0-3 km storm-relative helicity
- 195 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted.
473
ACUS11 KWNS 252305
SWOMCD
SPC MCD 252304
INZ000-WIZ000-ILZ000-260030-
MESOSCALE DISCUSSION 0446
NWS STORM PREDICTION CENTER NORMAN OK
0604 PM CDT MON APR 25 2016
AREAS AFFECTED...PORTIONS OF SERN WI...NRN IL...AND FAR NWRN IND
CONCERNING...SEVERE THUNDERSTORM WATCH 103...
VALID 252304Z - 260030Z
THE SEVERE WEATHER THREAT FOR SEVERE THUNDERSTORM WATCH 103
CONTINUES.
SUMMARY...MAINLY A LARGE HAIL AND STRONG/GUSTY WIND THREAT SHOULD
CONTINUE FOR THE NEXT SEVERAL HOURS. THE SEVERE THREAT SHOULD
DIMINISH LATER THIS EVENING.
DISCUSSION...CONVECTION ACROSS WW 103 HAS BEEN MAINLY CONFINED TO
FAR ERN WI AND NERN IL THUS FAR ALONG A CONVERGENT LAKE BREEZE
BOUNDARY OFF LAKE MICHIGAN. MOST HAIL REPORTS OVER THE PAST FEW
HOURS HAVE REMAINED SUB-SEVERE...PROBABLY DUE TO LIMITED LOW-LEVEL
MOISTURE RESULTING IN JUST A WEAKLY UNSTABLE THERMODYNAMIC PROFILE.
MID-LEVEL FLOW AROUND 40-50 KT ALONG WITH SOME VEERING OF SWLY
LOW-LEVEL WINDS WITH HEIGHT SHOULD CONTINUE TO ALLOW ANY STRONGER
CORES ALONG THE LAKE BREEZE TO PRODUCE ISOLATED LARGE HAIL AND
STRONG/GUSTY WINDS. THE SEVERE THREAT SHOULD GRADUALLY DIMINISH OVER
THE NEXT FEW HOURS AS DIURNAL COOLING FURTHER REDUCES THE ALREADY
LIMITED INSTABILITY AND ONGOING THUNDERSTORMS MOVE EWD OVER LAKE
MICHIGAN.
..GLEASON.. 04/25/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...ILX...MKX...DVN...
LAT...LON 40988987 41348981 42238930 42848881 43648848 43858819
43838717 41288699 40968834 40978942 40988987SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 25, 1:40 PM CDT | Mesoscale Discussion | SPC | Boone, Carroll, Cook, DeKalb, DuPage, Kane and 8 more | 2 hr |
| Apr 25, 2:17 PM CDT | Severe Thunderstorm Watch | SPC | Boone, Bureau, Carroll, Cook, DeKalb, DuPage and 20 more | 8 hr |
Nearby
Mesoscale Discussions in Illinois, 2016Mesoscale Discussions in Wisconsin, 2016Mesoscale Discussions in Indiana, 2016Every mesoscale discussion in 2016
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.