Alert archive / Illinois / Special Weather Statements in 2017

Special Weather Statement, NWS Quad Cities, IA

July 7, 2017Des Moines County, Lee County, Iowa; Hancock County, Henderson County, McDonough County, Illinois; Clark County, Missouri

NWS Quad Cities, IA issued this special weather statement at Jul 7, 2017, 3:38 AM CDT for Des Moines County, Lee County, Iowa; Hancock County, Henderson County, McDonough County, Illinois; Clark County, Missouri. It was in force for 37 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 7, 2017, 3:38 AM CDT (08:38 UTC)
Expired: Jul 7, 2017, 4:15 AM CDT
In force: 37 min
Issued by: NWS Quad Cities, IA

Counties Des Moines County, IA, Lee County, IA, Hancock County, IL, Henderson County, IL, McDonough County, IL, Clark County, MO

The radar

The Quad Cities radar (KDVN), 148 km from the middle of the area, began a volume at 08:41 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, 8.6 hours before the alert went out and 151 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: 1175 J/kg
Mixed-layer CIN: -37 J/kg
Mixed-layer LCL: 1720 m above ground
0-6 km bulk shear: 42 kt
0-1 km storm-relative helicity: 55 m²/s²
0-3 km storm-relative helicity: 186 m²/s²
Significant tornado parameter: 0.2
Supercell composite: 5.4

Open this sounding in Storm Lab

The text

As transmitted.

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What forecasters said that day

The local office's own words before this special weather statement went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Quad Cities, IA wrote its last area forecast discussion before this special weather statement went out at Jul 6, 11:35 PM CDT, 4 hours 3 minutes earlier.

Area forecast discussion, Jul 6, 11:35 PM CDT, 4 hours 3 minutes before

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Hazardous weather outlook, Jul 6, 8:33 PM CDT, 7 hours 5 minutes before

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In the hours before

Special weather statement, Jul 7, 1:06 AM CDT, 2 hours 32 minutes before

Special Weather Statement
National Weather Service Quad Cities IA/IL
106 AM CDT FRI JUL 7 2017

IAC011-070645-
Benton-
106 AM CDT FRI JUL 7 2017

...A STRONG THUNDERSTORM WILL AFFECT BENTON COUNTY UNTIL 145 AM
CDT...

At 106 AM CDT, a strong thunderstorm was located over Dysart, or 13
miles west of Vinton, moving east at 30 mph.

Wind gusts up to 50 mph and nickel size hail are possible with this
storm.

Locations impacted include...
Vinton, Atkins, Urbana, Dysart, Shellsburg, Newhall, Van Horne,
Keystone, Garrison, Vinton Memorial Airport, Rodgers Park, Benton
City Park, Hoefle-Dulin Park, Benton County Fairgrounds and Wildcat
Bluff Park.

This includes Interstate 380 between mile markers 40 and 42.

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.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4224 9230 4223 9183 4193 9183 4201 9230
TIME...MOT...LOC 0606Z 277DEG 31KT 4215 9229

12

Special weather statement, Jul 7, 1:38 AM CDT, 2 hours before

Special Weather Statement
National Weather Service Quad Cities IA/IL
138 AM CDT FRI JUL 7 2017

IAC011-095-103-113-070745-
Johnson-Benton-Linn-Iowa-
138 AM CDT FRI JUL 7 2017

...A CLUSTER OF STRONG THUNDERSTORMS WILL AFFECT NORTHWESTERN
JOHNSON...BENTON...SOUTHERN LINN AND IOWA COUNTIES UNTIL 245 AM
CDT...

At 135 AM CDT, radar indicated a group of strong thunderstorms
located from near Vinton to near Ladora. Movement was east at 25 mph.

Wind gusts up to 50 mph and dime size hail are possible with these
storms. Move indoors as these storms approach your area.

Locations impacted include...
Cedar Rapids, Vinton, Marengo, Marion, Hiawatha, Robins,
Williamsburg, Belle Plaine, Center Point, Fairfax, Tiffin, Ely,
Atkins, Walford, Palo, Shellsburg, Victor, Swisher, Newhall and
Oxford.

This includes the following highways...
 Interstate 80 in Iowa between mile markers 208 and 236.
 Interstate 380 between mile markers 6 and 36.

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

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

LAT...LON 4188 9230 4220 9212 4215 9142 4157 9177
      4171 9230
TIME...MOT...LOC 0635Z 279DEG 21KT 4212 9207 4179 9226

12

Special weather statement, Jul 7, 2:43 AM CDT, 55 minutes before

Special Weather Statement
National Weather Service Quad Cities IA/IL
243 AM CDT FRI JUL 7 2017

IAC087-115-183-070845-
Henry-Louisa-Washington-
243 AM CDT FRI JUL 7 2017

...A STRONG THUNDERSTORM WILL AFFECT NORTHEASTERN HENRY...
NORTHWESTERN LOUISA AND WASHINGTON COUNTIES UNTIL 345 AM CDT...

At 243 AM CDT, a strong thunderstorm was located near Washington,
moving southeast at 25 mph.

Wind gusts up to 50 mph and nickel size hail are possible with this
storm.

Locations impacted include...
Washington, Columbus Junction, Winfield, Ainsworth, Columbus City,
Crawfordsville, Cotter, Wyman, Richmond, Fredonia, West Chester,
Washington Airport, Marr Park, Haskins, Louisa County Fairgrounds,
Washington County Fairgrounds and Gladwin.

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 4146 9175 4139 9137 4134 9137 4134 9129
      4108 9142 4130 9185
TIME...MOT...LOC 0743Z 294DEG 15KT 4136 9172

12

Special weather statement, Jul 7, 3:38 AM CDT, 0 minutes before

Special Weather Statement
National Weather Service Quad Cities IA/IL
338 AM CDT FRI JUL 7 2017

ILC067-071-109-187-IAC057-111-MOC045-070915-
Hancock-Henderson-Warren-McDonough-Des Moines-Lee-Clark-
338 AM CDT FRI JUL 7 2017

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT HANCOCK...HENDERSON...
SOUTHERN WARREN...MCDONOUGH...CENTRAL DES MOINES...LEE AND CLARK
COUNTIES UNTIL 415 AM CDT...

At 336 AM CDT, strong thunderstorms were clustered near Burlington
through Keokuk, moving southeast at 35 mph.

Winds in excess of 40 mph, brief heavy rainfall, and pea size hail
are possible with these storms.

Locations impacted include...
Burlington, Macomb, Fort Madison, Keokuk, Carthage, Kahoka, Nauvoo,
Bushnell, West Burlington, Hamilton, Warsaw, Colchester, La Harpe,
Roseville, West Point, Dallas City, Montrose, Stronghurst, Avon and
Blandinsville.

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 4020 9150 4025 9150 4025 9178 4032 9193
      4099 9113 4071 9044 4028 9045 4028 9091
      4019 9091
TIME...MOT...LOC 0836Z 302DEG 53KT 4087 9110

ERVIN

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 7, 1:06 AM CDT	Special Weather Statement	DVN	Benton	39 min
Jul 7, 1:38 AM CDT	Special Weather Statement	DVN	Benton, Iowa, Linn	67 min
Jul 7, 2:43 AM CDT	Special Weather Statement	DVN	Washington	62 min
Jul 7, 3:58 AM CDT	Severe Thunderstorm Warning	DVN	Hancock, Henderson, McDonough, Warren	49 min
Jul 7, 4:57 AM CDT	Special Weather Statement	DVN	Hancock	33 min

Nearby

Special Weather Statements in Illinois, 2017 Special Weather Statements in Iowa, 2017 Special Weather Statements in Missouri, 2017 Every special weather statement in 2017

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.