Alert archive / Illinois / Special Weather Statements in 2018

Special Weather Statement, NWS Quad Cities, IA

August 17, 2018Hancock County, Illinois

NWS Quad Cities, IA issued this special weather statement at Aug 17, 2018, 1:07 AM CDT for Hancock County, Illinois. It was in force for 38 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
Aug 17, 2018, 1:07 AM CDT (06:07 UTC)
Expired
Aug 17, 2018, 1:45 AM CDT
In force
38 min
Issued by
NWS Quad Cities, IA

County Hancock County, IL

The radar

The Quad Cities radar (KDVN), 156 km from the middle of the area, began a volume at 06:10 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, 6.1 hours before the alert went out and 159 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, Davenport, at 00:00Z on 2018-08-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1949 joules per kilogram.LCLEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 00:00Z on 2018-08-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
1949 J/kg
Mixed-layer CIN
-2 J/kg
Mixed-layer LCL
837 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
57 m²/s²
Significant tornado parameter
0.3
Supercell composite
2.6

Open this sounding in Storm Lab

The text

As transmitted.

915 
WWUS83 KDVN 170607
SPSDVN

Special Weather Statement
National Weather Service Quad Cities IA/IL
107 AM CDT FRI AUG 17 2018

ILC067-109-170645-
Hancock-McDonough-
107 AM CDT FRI AUG 17 2018

...A STRONG THUNDERSTORM WILL AFFECT SOUTHERN HANCOCK AND
SOUTHWESTERN MCDONOUGH COUNTIES UNTIL 145 AM CDT...

At 105 AM CDT, a strong thunderstorm was located near Mendon, or 12
miles east of Canton, moving northeast at 25 mph.

Winds in excess of 40 mph and nickel size hail are possible with this
storm.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

LAT...LON 4021 9151 4024 9151 4034 9147 4038 9141
      4039 9138 4040 9075 4028 9076 4028 9091
      4019 9091
TIME...MOT...LOC 0605Z 230DEG 21KT 4017 9129 

$$

Sheets

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Aug 16, 7:04 PM CDTSpecial Weather StatementDVNScott26 min
Aug 16, 10:22 PM CDTSpecial Weather StatementDVNVan Buren53 min
Aug 16, 10:54 PM CDTSpecial Weather StatementDVNVan Buren51 min
Aug 17, 6:41 AM CDTDense Fog AdvisoryDVNMuscatine, Scott2 hr
Aug 16, 7:21 PM CDTSpecial Weather StatementDVNRock Island24 min
Aug 16, 7:54 PM CDTSpecial Weather StatementDVNMcDonough21 min
Aug 16, 7:55 PM CDTSpecial Weather StatementDVNStephenson80 min
Aug 16, 8:27 PM CDTTornado Warning Tornado observedDVNStephenson18 min
Aug 16, 10:06 PM CDTSpecial Weather StatementDVNPutnam24 min
Aug 17, 12:16 AM CDTSpecial Weather StatementDVNClark, Scotland44 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.