Alert archive / Illinois / Special Weather Statements in 2018

Special Weather Statement, NWS St. Louis, MO

July 1, 2018Montgomery County, Illinois

NWS St. Louis, MO issued this special weather statement at Jul 1, 2018, 5:21 PM CDT for Montgomery County, Illinois. It was in force for 39 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Jul 1, 2018, 5:21 PM CDT (22:21 UTC)
Expired
Jul 1, 2018, 6:00 PM CDT
In force
39 min
Issued by
NWS St. Louis, MO

County Montgomery County, IL

The radar

The Lincoln radar (KILX), 91 km from the middle of the area, began a volume at 22:23 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, 10.4 hours before the alert went out and 119 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-pSkew-T log-p diagram, Lincoln, IL at 12:00Z on 2018-07-01Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1834 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Lincoln, IL at 12:00Z on 2018-07-01The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 123 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
1834 J/kg
Mixed-layer CIN
-58 J/kg
Mixed-layer LCL
867 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
123 m²/s²
0-3 km storm-relative helicity
109 m²/s²
Significant tornado parameter
0.0
Supercell composite
2.5

Open this sounding in Storm Lab

The text

As transmitted.

410 
WWUS83 KLSX 012221
SPSLSX

Special Weather Statement
National Weather Service St Louis MO
521 PM CDT SUN JUL 1 2018
 
ILZ059-060-012300-
Macoupin IL-Montgomery IL-
521 PM CDT SUN JUL 1 2018

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL MACOUPIN AND
NORTHWESTERN MONTGOMERY COUNTIES UNTIL 600 PM CDT...

At 521 PM CDT, Doppler radar was tracking a strong thunderstorm near
Litchfield, moving east at 20 mph.

Winds in excess of 40 mph will be possible with this storm.

Locations impacted include...
Litchfield, Hillsboro, Raymond, Witt, White Oak, Farmersville,
Irving, Coalton, Waggoner, Nilwood, Harvel, Butler, Standard City,
Hornsby, Atwater and Honey Bend.

This includes Interstate 55 in Illinois between exits 52 and 63.
 
This also includes  Lake Lou Yaeger.
 
A Severe Thunderstorm Watch remains in effect until 800 PM CDT for
south central and southwestern Illinois.

LAT...LON 3923 8927 3914 8979 3937 8986 3953 8954
      3952 8953 3935 8953 3935 8933
TIME...MOT...LOC 2221Z 251DEG 19KT 3925 8974 

$$

Kanofsky

The office that day

Everything else NWS St. Louis, MO issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Jul 1, 4:59 PM CDTSpecial Weather StatementLSXSaint Louis46 min
Jul 1, 5:45 PM CDTSpecial Weather StatementLSXSaint Charles45 min
Jul 1, 6:38 PM CDTSpecial Weather StatementLSXSaint Louis52 min
Jul 1, 4:50 PM CDTSpecial Weather StatementLSXJersey40 min
Jul 1, 5:25 PM CDTSpecial Weather StatementLSXMadison50 min
Jul 1, 6:03 PM CDTSevere Thunderstorm WarningLSXBond, Macoupin, Madison, Montgomery42 min
Jul 1, 6:43 PM CDTSpecial Weather StatementLSXBond, Montgomery47 min

Nearby

Special Weather Statements in Illinois, 2018Every special weather statement 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.