Alert archive / Illinois / Mesoscale Discussions in 2012

Mesoscale Discussion 1337

July 1, 20124 states

The Storm Prediction Center issued this mesoscale discussion at Jul 1, 2012, 1:59 PM CDT for 4 states. It was in force for 61 min.

The area

The outline as issued.

The facts

Issued: Jul 1, 2012, 1:59 PM CDT (18:59 UTC)
Expired: Jul 1, 2012, 3:00 PM CDT
In force: 61 min
Issued by: the Storm Prediction Center
Chance of a watch: 20%

All 23 counties

Franklin County, IL, Gallatin County, IL, Hamilton County, IL, Hardin County, IL, Jackson County, IL, Johnson County, IL, Perry County, IL, Pope County, IL, Randolph County, IL, Saline County, IL, Union County, IL, White County, IL, Williamson County, IL, Posey County, IN, Crittenden County, KY, Union County, KY, Bollinger County, MO, Cape Girardeau County, MO, Iron County, MO, Madison County, MO, Perry County, MO, Saint Francois County, MO, Sainte Genevieve County, MO

The radar

The Paducah radar (KPAH), 108 km from the middle of the area, began a volume at 19:01 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

Lincoln, IL (KILX), launched 12:00Z, 7.0 hours before the alert went out and 282 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.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.

Mixed-layer CAPE: 2061 J/kg
Mixed-layer CIN: -149 J/kg
Mixed-layer LCL: 1957 m above ground
0-6 km bulk shear: 15 kt
0-1 km storm-relative helicity: 51 m²/s²
0-3 km storm-relative helicity: 67 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

357 
ACUS11 KWNS 011900
SWOMCD
SPC MCD 011859
KYZ000-INZ000-ILZ000-MOZ000-012000-

MESOSCALE DISCUSSION 1337
NWS STORM PREDICTION CENTER NORMAN OK
0159 PM CDT SUN JUL 01 2012

AREAS AFFECTED...SERN MO / SRN IL / FAR WRN KY AND SWRN IND

CONCERNING...SEVERE POTENTIAL...WATCH UNLIKELY

VALID 011859Z - 012000Z

PROBABILITY OF WATCH ISSUANCE...20 PERCENT

SUMMARY...ISOLD-WIDELY SCTD TSTMS ARE EXPECTED TO DEVELOP THIS
AFTERNOON.  ISOLD MICROBURSTS WILL POTENTIALLY BE CAPABLE OF POCKETS
OF STRONG TO SEVERE WIND GUSTS.

DISCUSSION...VISIBLE SATELLITE IMAGERY SHOWS A SMALL AGITATED CU
FIELD WITH A FEW TSTMS DEVELOPING IN THE PAST HOUR.  STRONG SURFACE
HEATING HAS RESULTED IN TEMPS WARMING INTO THE LOWER 100S WITH 30-40
DEG F TEMP/DEWPOINT SPREADS AND DRY ADIABATIC LOW LEVEL LAPSE RATES.
DESPITE WEAK TROPOSPHERIC FLOW...APPRECIABLE PW /AOA 1.5 INCH/ AND
DCAPE IN EXCESS OF 1500 J/KG WILL SUPPORT A HYBRID MICROBURST
ENVIRONMENT AND A RISK FOR POCKETS OF STRONG TO LOWER-END SEVERE
WIND GUSTS /I.E. WIND DAMAGE POTENTIAL/.

..SMITH/THOMPSON.. 07/01/2012

...PLEASE SEE WWW.SPC.NOAA.GOV FOR GRAPHIC PRODUCT...

ATTN...WFO...PAH...LSX...

LAT...LON   37679108 38069073 38358833 38008775 37358788 37129070
            37679108

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 1, 11:33 AM CDT	Mesoscale Discussion	SPC	Cook, DeKalb, DuPage, Grundy, Iroquois, Kane and 4 more	57 min
Jul 1, 12:16 PM CDT	Severe Thunderstorm Watch	SPC	Cook, DuPage, Iroquois, Kankakee, Will	6 hr
Jul 1, 2:56 PM CDT	Mesoscale Discussion	SPC	Adams, Allen, Blackford, Cass, DeKalb, Delaware and 20 more	94 min
Jul 1, 4:59 PM CDT	Severe Thunderstorm Watch	SPC	Clark, Crawford, Dearborn, Dubois, Floyd, Franklin and 9 more	5 hr
Jul 1, 8:27 AM CDT	Mesoscale Discussion	SPC	Floyd, Harlan, Knott, Letcher, Perry, Pike	63 min
Jul 1, 3:32 PM CDT	Severe Thunderstorm Watch	SPC	Boyd, Greenup	6 hr
Jun 30, 8:45 PM CDT	Mesoscale Discussion	SPC	Andrew, Buchanan, Caldwell, Carroll, Clay, Clinton and 15 more	90 min

Nearby

Mesoscale Discussions in Illinois, 2012 Mesoscale Discussions in Missouri, 2012 Mesoscale Discussions in Kentucky, 2012 Every mesoscale discussion in 2012

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.