Alert archive / Illinois / Mesoscale Discussions in 2016
Mesoscale Discussion 930
The Storm Prediction Center issued this mesoscale discussion at Jun 14, 2016, 11:27 PM CDT for 6 counties in Illinois. It was in force for 93 min.
The area
The outline as issued.
The facts
- Issued
- Jun 14, 2016, 11:27 PM CDT (04:27 UTC)
- Expired
- Jun 15, 2016, 1:00 AM CDT
- In force
- 93 min
- Issued by
- the Storm Prediction Center
- Chance of a watch
- 5%
Counties DeKalb County, IL, Kane County, IL, Kendall County, IL, LaSalle County, IL, Lee County, IL, Ogle County, IL
The radar
The Chicago radar (KLOT), 82 km from the middle of the area, began a volume at 04:27 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 00:00Z, 4.5 hours before the alert went out and 121 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
- 2459 J/kg
- Mixed-layer CIN
- -15 J/kg
- Mixed-layer LCL
- 663 m above ground
- 0-6 km bulk shear
- 39 kt
- 0-1 km storm-relative helicity
- 202 m²/s²
- 0-3 km storm-relative helicity
- 209 m²/s²
- Significant tornado parameter
- 2.3
- Supercell composite
- 11.2
The text
As transmitted.
159
ACUS11 KWNS 150428
SWOMCD
SPC MCD 150427
ILZ000-150600-
MESOSCALE DISCUSSION 0930
NWS STORM PREDICTION CENTER NORMAN OK
1127 PM CDT TUE JUN 14 2016
AREAS AFFECTED...PORTIONS OF NRN IL
CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY
VALID 150427Z - 150600Z
PROBABILITY OF WATCH ISSUANCE...5 PERCENT
SUMMARY...TSTMS CROSSING PARTS OF NRN IL OVERNIGHT MAY PRODUCE
LOCALLY STRONG WIND GUSTS. AN ISOLATED DMGG WIND GUST CANNOT BE
RULED OUT...THOUGH WW ISSUANCE IS NOT ANTICIPATED.
DISCUSSION...A FORWARD-PROPAGATING CONVECTIVE CLUSTER FROM
STEPHENSON TO WHITESIDE COUNTIES HAS RECENTLY SHOWN SIGNS OF AN EWD
SURGE/ACCELERATION...WITH FORWARD MOTION AROUND 30-35 KT. THIS
ACTIVITY GREW UPSCALE FROM MERGING COLD POOLS IN SUCCESSION TO
DIURNALLY ENHANCED CONVECTION UPSTREAM...AND WILL CONTINUE SPREADING
EWD ACROSS NRN IL. WITH PW AROUND 1.75-2.00 INCHES IN THE MOIST AIR
MASS ACROSS THE REGION PER GPS IMAGERY...WATER LOADING MAY
CONTRIBUTE TO STRONG TSTM WIND GUSTS...AS AROUND 500-1000 J/KG OF
MLCAPE LINGERS ACROSS THE AREA. CONTINUED NOCTURNAL COOLING AND
RELATED GAINS IN MLCINH SHOULD TEND TO MINIMIZE THIS RISK AS
CONVECTION SPREADS TOWARD THE CHICAGO METROPOLITAN AREA...WHERE IT
WILL BEGIN TO INGEST DRIER BOUNDARY-LAYER AIR. WITH THE PRIMARY
LARGE-SCALE ASCENT/LOW-LEVEL MASS RESPONSE FOCUSED N OF THE
REGION...THE SVR RISK SHOULD BE MINIMAL OVERALL.
..COHEN/CORFIDI.. 06/15/2016
...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...
ATTN...WFO...LOT...DVN...
LAT...LON 41538968 42118957 42328872 42018820 41308836 41338916
41538968SPC that day
Everything else SPC issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Jun 14, 7:18 PM CDT | Mesoscale Discussion | SPC | Christian, Clay, DeWitt, Effingham, Fayette, Logan and 7 more | 117 min |
| Jun 14, 8:36 PM CDT | Mesoscale Discussion | SPC | Carroll, Jo Daviess, Whiteside | 84 min |
| Jun 15, 12:05 PM CDT | Mesoscale Discussion | SPC | Alexander, Gallatin, Hardin, Johnson, Massac, Pope and 3 more | 85 min |
| Jun 15, 12:39 PM CDT | Severe Thunderstorm Watch | SPC | Alexander, Edwards, Franklin, Gallatin, Hamilton, Hardin and 10 more | 8 hr |
| Jun 15, 2:23 PM CDT | Mesoscale Discussion | SPC | Champaign, Christian, Clark, Coles, Cumberland, Douglas and 6 more | 97 min |
| Jun 15, 3:00 PM CDT | Severe Thunderstorm Watch | SPC | Clark, Clay, Coles, Crawford, Cumberland, Douglas and 9 more | 5 hr |
| Jun 15, 6:01 PM CDT | Mesoscale Discussion | SPC | Wabash | 59 min |
Nearby
Mesoscale Discussions in Illinois, 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.