Alert archive / Iowa / Severe Thunderstorm Warnings in 2017

Severe Thunderstorm Warning 76, NWS Quad Cities, IA

May 17, 20174 counties in Illinois; 7 counties in Iowa

NWS Quad Cities, IA issued this severe thunderstorm warning at May 17, 2017, 7:14 PM CDT for 4 counties in Illinois; 7 counties in Iowa. It was in force for 61 min. 13 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
May 17, 2017, 7:14 PM CDT (00:14 UTC)
Expired
May 17, 2017, 8:15 PM CDT
In force
61 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Hail
1.25 in
Wind
70.0 mph

Counties Cedar County, IA, Clinton County, IA, Dubuque County, IA, Jackson County, IA, Jones County, IA, Muscatine County, IA, Scott County, IA, Carroll County, IL, Jo Daviess County, IL, Mercer County, IL, Rock Island County, IL

The radar

The Quad Cities radar (KDVN), 40 km from the middle of the area, began a volume at 00:18 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.

What was reported inside it

TimeReportWhereRemark
May 17, 7:20 PM CDTTSTM WND DMGAsbury, IATREE SPLIT IN HALF AT CORNER OF SUN VALLEY DR AND SPRING GREEN ST. ALSO SEVERAL BRANCHES DOWN.
May 17, 7:20 PM CDTTSTM WND GST 60Asbury, IA
May 17, 7:44 PM CDTTORNADO 03 Wnw Donahue, IAA SQUALL LINE TORNADO CAUSED SPORADIC EF-0 DAMAGE ALONG ITS TWO MILE PATH. NUMEROUS TREES WERE DAMAGED WITH A FEW ROTTEN TREES SNAPPED. ROOFING DAMAGE TO A NEW HOME AND GARAGE WERE NOTED AT THE BEGINNING OF THE PATH. THE PEAK ESTIMATED WIND SPEED WAS 80 MPH AL
May 17, 7:44 PM CDTTORNADO 03 Wnw Donahue, IAA SQUALL LINE TORNADO CAUSED SPORADIC EF-0 DAMAGE ALONG ITS TWO MILE PATH. NUMEROUS TREES WERE DAMAGED WITH A FEW ROTTEN TREES SNAPPED. ROOFING DAMAGE TO A NEW HOME AND GARAGE WERE NOTED AT THE BEGINNING OF THE PATH. THE PEAK ESTIMATED WIND SPPED WAS 80 MPH AL
May 17, 7:44 PM CDTTORNADO 13 Wnw Donahue, IAA SQUALL LINE TORNADO CAUSED A PATH OF EF-1 DAMAGE ALONG ITS TWO MILE PATH. NUMEROUS TREES WERE DAMAGED A PATH THROUGH A FOREST VALLEY OF SNAPPED OFF TREES AND UPROOTED MATURE TREES. ROOFING DAMAGE TO A NEW HOME AND GARAGE WERE NOTED AT THE BEGINNING OF THE PA
May 17, 7:50 PM CDTHAIL 0.51 N Walcott, IAPEA TO DIMES AT I-80 TRUCK STOP.
May 17, 7:54 PM CDTTSTM WND GST 73Welton, IAWINDS SUSTAINED 50-60 MPH FOR 5 MINUTES
May 17, 7:54 PM CDTHAIL 11 N Walcott, IAAT I-80 TRUCK STOP.
May 17, 7:59 PM CDTTSTM WND GST 60Donahue, IAVERY HEAVY RAIN FALLING.
May 17, 8:03 PM CDTTSTM WND GST 59Dewitt, IARWIS SITE NEAR US 30/HWY 61
May 17, 8:10 PM CDTTSTM WND GST 60Preston, IA50 TO 60 MPH SUSTAINED
May 17, 8:25 PM CDTTSTM WND GST 55Davenport Municipal Air, IA
May 17, 8:25 PM CDTHAIL 0.5Davenport Municipal Air, IA

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 7 storm reports to this severe thunderstorm warning; the first came 6 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 17, 3:44 PM CDTTornado WatchSPC9 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.2 hours before the alert went out and 41 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 2017-05-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1161 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, Davenport, at 00:00Z on 2017-05-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 211 square meters per square second.19395878Sfc1 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
1161 J/kg
Mixed-layer CIN
-9 J/kg
Mixed-layer LCL
1502 m above ground
0-6 km bulk shear
53 kt
0-1 km storm-relative helicity
211 m²/s²
0-3 km storm-relative helicity
306 m²/s²
Significant tornado parameter
1.0
Supercell composite
7.2

Open this sounding in Storm Lab

The text

As transmitted.

174 
WUUS53 KDVN 180014
SVRDVN
ILC015-085-131-161-IAC031-045-061-097-105-139-163-180115-
/O.NEW.KDVN.SV.W.0076.170518T0014Z-170518T0115Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Quad Cities IA/IL
714 PM CDT WED MAY 17 2017

The National Weather Service in the Quad Cities has issued a

* Severe Thunderstorm Warning for...
  Rock Island County in northwestern Illinois...
  Mercer County in northwestern Illinois...
  Jo Daviess County in northwestern Illinois...
  Western Carroll County in northwestern Illinois...
  Jackson County in east central Iowa...
  Eastern Cedar County in east central Iowa...
  Scott County in east central Iowa...
  Dubuque County in northeastern Iowa...
  Eastern Jones County in east central Iowa...
  Eastern Muscatine County in east central Iowa...
  Clinton County in east central Iowa...

* Until 815 PM CDT

* At 713 PM CDT, severe thunderstorms were located along a line
  extending from near Elkader to near Cassville to Peosta to
  Grandview, moving northeast at 45 mph.

  HAZARD...70 mph wind gusts and half dollar size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect considerable 
           tree damage. Wind damage is also likely to mobile homes, 
           roofs, and outbuildings. 

* Locations impacted include...
  Davenport, Dubuque, Moline, Rock Island, Bettendorf, Clinton,
  Muscatine, East Moline, Maquoketa, Galena, Durant, Silvis,
  Eldridge, DeWitt, Milan, Camanche, Asbury, Le Claire, Coal Valley
  and Savanna.

This includes the following highways...
 Interstate 74 in Iowa between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 270 and 306.
 Interstate 80 in Illinois between mile markers 1 and 5.
 Interstate 74 in Illinois between mile markers 1 and 8.
 Interstate 88 between mile markers 1 and 4.
 Interstate 280 between mile markers 1 and 18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a DANGEROUS SITUATION. These storms are producing widespread
wind damage across Dubuque through Louisa counties. SEEK SHELTER NOW 
inside a sturdy structure and stay away from windows!
 
&&

A tornado watch remains in effect until 1100 PM CDT for northwestern
Illinois...and southeastern, northeastern and east central Iowa.

LAT...LON 4264 9072 4251 9064 4251 8998 4181 9018
      4178 9024 4167 9022 4152 9026 4151 9036
      4144 9043 4120 9107 4124 9111 4133 9107
      4134 9111 4231 9095 4265 9111 4265 9090
      4267 9089
TIME...MOT...LOC 0013Z 222DEG 38KT 4288 9149 4275 9103 4246 9085 4128
9121

HAIL...1.25IN
WIND...70MPH
 
$$

ERVIN
7 follow-up statements
651 
WWUS53 KDVN 180022
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
722 PM CDT WED MAY 17 2017

ILC015-085-131-161-IAC031-045-061-097-105-139-163-180115-
/O.CON.KDVN.SV.W.0076.000000T0000Z-170518T0115Z/
Rock Island IL-Mercer IL-Jo Daviess IL-Carroll IL-Jackson IA-
Cedar IA-Scott IA-Dubuque IA-Jones IA-Muscatine IA-Clinton IA-
722 PM CDT WED MAY 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR ROCK ISLAND...NORTHWESTERN MERCER...JO DAVIESS...WESTERN
CARROLL...JACKSON...EASTERN CEDAR...SCOTT...DUBUQUE...EASTERN
JONES...EASTERN MUSCATINE AND CLINTON COUNTIES...

At 721 PM CDT, severe thunderstorms were located along a line
extending from near Farmersburg to 6 miles north of Cassville to
Asbury to Fruitland, moving northeast at 45 mph.

HAZARD...70 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings. 

Locations impacted include...
Davenport, Dubuque, Moline, Rock Island, Bettendorf, Clinton,
Muscatine, East Moline, Maquoketa, Galena, Durant, Silvis, Eldridge,
DeWitt, Milan, Camanche, Asbury, Le Claire, Coal Valley and Savanna.

This includes the following highways...
 Interstate 74 in Iowa between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 270 and 306.
 Interstate 80 in Illinois between mile markers 1 and 5.
 Interstate 74 in Illinois between mile markers 1 and 8.
 Interstate 88 between mile markers 1 and 4.
 Interstate 280 between mile markers 1 and 18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a DANGEROUS SITUATION. These storms are producing widespread
wind damage across Dubuque through Muscatine county. SEEK SHELTER NOW 
inside a sturdy structure and stay away from windows.
 
&&

A tornado watch remains in effect until 1100 PM CDT for northwestern
Illinois...and southeastern, northeastern and east central Iowa.

LAT...LON 4264 9072 4251 9064 4251 8998 4181 9018
      4178 9024 4167 9022 4152 9026 4151 9036
      4144 9043 4120 9107 4124 9111 4133 9107
      4134 9111 4231 9095 4265 9111 4265 9090
      4267 9089
TIME...MOT...LOC 0021Z 222DEG 38KT 4293 9143 4280 9097 4251 9079 4133
9115

HAIL...1.00IN
WIND...70MPH
 
$$

ERVIN
646 
WWUS53 KDVN 180031
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
731 PM CDT WED MAY 17 2017

ILC015-085-131-161-IAC031-045-061-097-105-139-163-180115-
/O.CON.KDVN.SV.W.0076.000000T0000Z-170518T0115Z/
Rock Island IL-Mercer IL-Jo Daviess IL-Carroll IL-Jackson IA-
Cedar IA-Scott IA-Dubuque IA-Jones IA-Muscatine IA-Clinton IA-
731 PM CDT WED MAY 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR ROCK ISLAND...NORTHWESTERN MERCER...JO DAVIESS...WESTERN
CARROLL...JACKSON...EASTERN CEDAR...SCOTT...DUBUQUE...EASTERN
JONES...EASTERN MUSCATINE AND CLINTON COUNTIES...

At 730 PM CDT, severe thunderstorms were located along a line
extending from near Fennimore to East Dubuque to near Nashville to
near Muscatine, moving east at 35 mph.

HAZARD...70 mph wind gusts and quarter size hail. 

SOURCE...Trained weather spotters. 

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings. 

Locations impacted include...
Davenport, Dubuque, Moline, Rock Island, Bettendorf, Clinton,
Muscatine, East Moline, Maquoketa, Galena, Durant, Silvis, Eldridge,
DeWitt, Milan, Camanche, Asbury, Le Claire, Coal Valley and Savanna.

This includes the following highways...
 Interstate 74 in Iowa between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 270 and 306.
 Interstate 80 in Illinois between mile markers 1 and 5.
 Interstate 74 in Illinois between mile markers 1 and 8.
 Interstate 88 between mile markers 1 and 4.
 Interstate 280 between mile markers 1 and 18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
sturdy building.

This is a DANGEROUS SITUATION. These storms are producing widespread
wind damage across southeast Jones, Clinton, and Jackson county. SEEK 
SHELTER NOW inside a sturdy structure and stay away from windows.
 
&&

A tornado watch remains in effect until 1100 PM CDT for northwestern
Illinois...and southeastern, northeastern and east central Iowa.

LAT...LON 4264 9072 4251 9064 4251 8998 4181 9018
      4178 9024 4167 9022 4152 9026 4151 9036
      4144 9043 4120 9107 4124 9111 4133 9107
      4134 9111 4231 9095 4265 9111 4265 9090
      4267 9089
TIME...MOT...LOC 0030Z 278DEG 29KT 4291 9065 4248 9063 4203 9083 4144
9101

HAIL...1.00IN
WIND...70MPH
 
$$

ERVIN
926 
WWUS53 KDVN 180039
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
739 PM CDT WED MAY 17 2017

ILC015-085-131-161-IAC031-045-061-097-105-139-163-180115-
/O.CON.KDVN.SV.W.0076.000000T0000Z-170518T0115Z/
Rock Island IL-Mercer IL-Jo Daviess IL-Carroll IL-Jackson IA-
Cedar IA-Scott IA-Dubuque IA-Jones IA-Muscatine IA-Clinton IA-
739 PM CDT WED MAY 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR ROCK ISLAND...NORTHWESTERN MERCER...JO DAVIESS...WESTERN
CARROLL...JACKSON...EASTERN CEDAR...SCOTT...DUBUQUE...EASTERN
JONES...EASTERN MUSCATINE AND CLINTON COUNTIES...

At 738 PM CDT, severe thunderstorms were located along a line
extending from near Fennimore to near Galena to near Calamus to
Eliza, moving northeast at 40 mph.

HAZARD...70 mph wind gusts and quarter size hail. 

SOURCE...Trained weather spotters. 

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings. 

Locations impacted include...
Davenport, Dubuque, Moline, Rock Island, Bettendorf, Clinton,
Muscatine, East Moline, Maquoketa, Galena, Durant, Silvis, Eldridge,
DeWitt, Milan, Camanche, Asbury, Le Claire, Coal Valley and Savanna.

This includes the following highways...
 Interstate 74 in Iowa between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 271 and 306.
 Interstate 80 in Illinois between mile markers 1 and 4.
 Interstate 74 in Illinois between mile markers 1 and 8.
 Interstate 88 between mile markers 1 and 4.
 Interstate 280 between mile markers 1 and 18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a DANGEROUS SITUATION. These storms are producing widespread
wind damage across Jackson through western Scott counties. SEEK 
SHELTER NOW inside a sturdy structure and stay away from windows.
 
&&

A tornado watch remains in effect until 1100 PM CDT for northwestern
Illinois...and southeastern, northeastern and east central Iowa.

LAT...LON 4264 9073 4251 9064 4251 8998 4181 9018
      4178 9024 4170 9024 4166 9022 4153 9026
      4152 9035 4144 9043 4121 9106 4125 9110
      4134 9106 4135 9110 4232 9094 4265 9109
      4265 9090 4267 9089
TIME...MOT...LOC 0038Z 240DEG 35KT 4296 9059 4239 9042 4190 9071 4130
9094

HAIL...1.00IN
WIND...70MPH
 
$$

ERVIN
047 
WWUS53 KDVN 180042
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
742 PM CDT WED MAY 17 2017

ILC015-085-131-161-IAC031-045-061-097-105-139-163-180115-
/O.CON.KDVN.SV.W.0076.000000T0000Z-170518T0115Z/
Rock Island IL-Mercer IL-Jo Daviess IL-Carroll IL-Jackson IA-
Cedar IA-Scott IA-Dubuque IA-Jones IA-Muscatine IA-Clinton IA-
742 PM CDT WED MAY 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR ROCK ISLAND...NORTHWESTERN MERCER...JO DAVIESS...WESTERN
CARROLL...JACKSON...EASTERN CEDAR...SCOTT...DUBUQUE...EASTERN
JONES...EASTERN MUSCATINE AND CLINTON COUNTIES...

At 741 PM CDT, severe thunderstorms were located along a line
extending from near Epworth to near Fulton to near Welton to near
Eliza, moving east at 30 mph.

HAZARD...70 mph wind gusts and quarter size hail. 

SOURCE...Trained weather spotters. 

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings. 

Locations impacted include...
Davenport, Dubuque, Moline, Rock Island, Bettendorf, Clinton,
Muscatine, East Moline, Maquoketa, Galena, Durant, Silvis, Eldridge,
DeWitt, Milan, Camanche, Asbury, Le Claire, Coal Valley and Savanna.

This includes the following highways...
 Interstate 74 in Iowa between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 271 and 306.
 Interstate 80 in Illinois between mile markers 1 and 4.
 Interstate 74 in Illinois between mile markers 1 and 8.
 Interstate 88 between mile markers 1 and 4.
 Interstate 280 between mile markers 1 and 18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This is a DANGEROUS SITUATION. These storms are producing widespread
wind damage across Jackson through western Rock Island counties. SEEK 
SHELTER NOW inside a sturdy structure and stay away from windows.
 
&&

A tornado watch remains in effect until 1100 PM CDT for northwestern
Illinois...and southeastern, northeastern and east central Iowa.

LAT...LON 4264 9073 4251 9064 4251 8998 4181 9018
      4178 9024 4170 9024 4166 9022 4153 9026
      4152 9035 4144 9043 4121 9106 4125 9110
      4134 9106 4135 9110 4232 9094 4265 9109
      4265 9090 4267 9089
TIME...MOT...LOC 0041Z 248DEG 25KT 4237 9093 4218 9067 4192 9066 4132
9089

HAIL...1.00IN
WIND...70MPH
 
$$

ERVIN
284 
WWUS53 KDVN 180049
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
749 PM CDT WED MAY 17 2017

ILC015-085-131-161-IAC031-045-061-097-105-139-163-180115-
/O.CON.KDVN.SV.W.0076.000000T0000Z-170518T0115Z/
Rock Island IL-Mercer IL-Jo Daviess IL-Carroll IL-Jackson IA-
Cedar IA-Scott IA-Dubuque IA-Jones IA-Muscatine IA-Clinton IA-
749 PM CDT WED MAY 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR ROCK ISLAND...NORTHWESTERN MERCER...JO DAVIESS...WESTERN
CARROLL...JACKSON...EASTERN CEDAR...SCOTT...DUBUQUE...EASTERN
JONES...EASTERN MUSCATINE AND CLINTON COUNTIES...

At 748 PM CDT, severe thunderstorms were located along a line
extending from near Peosta to near Andrew to Delmar to near Illinois
City, moving northeast at 45 mph.

HAZARD...70 mph wind gusts and half dollar size hail. 

SOURCE...Trained weather spotters. 

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings. 

Locations impacted include...
Davenport, Dubuque, Moline, Rock Island, Bettendorf, Clinton,
Muscatine, East Moline, Maquoketa, Galena, Durant, Silvis, Eldridge,
DeWitt, Milan, Camanche, Asbury, Le Claire, Coal Valley and Savanna.

This includes the following highways...
 Interstate 74 in Iowa between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 271 and 306.
 Interstate 80 in Illinois between mile markers 1 and 4.
 Interstate 74 in Illinois between mile markers 1 and 8.
 Interstate 88 between mile markers 1 and 4.
 Interstate 280 between mile markers 1 and 18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

This is a DANGEROUS SITUATION. These storms are producing widespread
wind damage across Jackson through Scott counties. SEEK SHELTER NOW 
inside a sturdy structure and stay away from windows.
 
&&

A tornado watch remains in effect until 1100 PM CDT for northwestern
Illinois...and southeastern, northeastern and east central Iowa.

LAT...LON 4264 9073 4251 9064 4251 8998 4181 9018
      4178 9024 4170 9024 4166 9022 4153 9026
      4152 9035 4144 9043 4121 9106 4125 9110
      4134 9106 4135 9110 4232 9094 4265 9109
      4265 9090 4267 9089
TIME...MOT...LOC 0048Z 224DEG 39KT 4242 9087 4221 9055 4197 9060 4137
9083

TORNADO...POSSIBLE
HAIL...1.25IN
WIND...70MPH
 
$$

ERVIN
698 
WWUS53 KDVN 180055
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
755 PM CDT WED MAY 17 2017

ILC015-085-131-161-IAC031-045-061-097-105-139-163-180115-
/O.CON.KDVN.SV.W.0076.000000T0000Z-170518T0115Z/
Rock Island IL-Mercer IL-Jo Daviess IL-Carroll IL-Jackson IA-
Cedar IA-Scott IA-Dubuque IA-Jones IA-Muscatine IA-Clinton IA-
755 PM CDT WED MAY 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR ROCK ISLAND...NORTHWESTERN MERCER...JO DAVIESS...WESTERN
CARROLL...JACKSON...EASTERN CEDAR...SCOTT...DUBUQUE...EASTERN
JONES...EASTERN MUSCATINE AND CLINTON COUNTIES...

At 755 PM CDT, severe thunderstorms were located along a line
extending from near East Dubuque to near Springbrook to near DeWitt
to near Illinois City, moving northeast at 40 mph.

HAZARD...70 mph wind gusts and quarter size hail. 

SOURCE...Trained weather spotters. 

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings. 

Locations impacted include...
Davenport, Dubuque, Moline, Rock Island, Bettendorf, Clinton,
Muscatine, East Moline, Maquoketa, Galena, Durant, Silvis, Eldridge,
DeWitt, Milan, Camanche, Asbury, Le Claire, Coal Valley and Savanna.

This includes the following highways...
 Interstate 74 in Iowa between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 271 and 306.
 Interstate 80 in Illinois between mile markers 1 and 4.
 Interstate 74 in Illinois between mile markers 1 and 8.
 Interstate 88 between mile markers 1 and 4.
 Interstate 280 between mile markers 1 and 18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

This is a DANGEROUS SITUATION. These storms are producing widespread
wind damage across Jackson and Clinton counties. SEEK SHELTER NOW 
inside a sturdy structure and stay away from windows.
 
&&

A tornado watch remains in effect until 1100 PM CDT for northwestern
Illinois...and southeastern, northeastern and east central Iowa.

LAT...LON 4264 9073 4251 9064 4251 8998 4181 9018
      4178 9024 4170 9024 4166 9022 4153 9026
      4152 9035 4144 9043 4121 9106 4125 9110
      4134 9106 4135 9110 4232 9094 4265 9109
      4265 9090 4267 9089
TIME...MOT...LOC 0055Z 241DEG 33KT 4243 9060 4216 9044 4177 9053 4139
9081

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

ERVIN
873 
WWUS53 KDVN 180100
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
800 PM CDT WED MAY 17 2017

IAC031-105-180110-
/O.CAN.KDVN.SV.W.0076.000000T0000Z-170518T0115Z/
Cedar IA-Jones IA-
800 PM CDT WED MAY 17 2017

...THE SEVERE THUNDERSTORM WARNING FOR EASTERN CEDAR AND EASTERN
JONES COUNTIES IS CANCELLED...

The storms which prompted the warning have moved out of
the warned area. Therefore, the warning has been cancelled.

A tornado watch remains in effect until 1100 PM CDT for northwestern
Illinois...and southeastern, northeastern and east central Iowa.

LAT...LON 4251 8998 4181 9018 4178 9024 4170 9024
      4166 9022 4153 9026 4152 9035 4146 9043
      4144 9043 4121 9106 4125 9110 4134 9106
      4135 9110 4182 9074 4217 9080 4236 9076
      4246 9077 4252 9071
TIME...MOT...LOC 0100Z 224DEG 61KT 4256 9048 4222 9036 4183 9045 4144
9074

$$

ILC015-085-131-161-IAC045-061-097-139-163-180115-
/O.CON.KDVN.SV.W.0076.000000T0000Z-170518T0115Z/
Rock Island IL-Mercer IL-Jo Daviess IL-Carroll IL-Jackson IA-
Scott IA-Dubuque IA-Muscatine IA-Clinton IA-
800 PM CDT WED MAY 17 2017

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 815 PM CDT
FOR ROCK ISLAND...NORTHWESTERN MERCER...JO DAVIESS...WESTERN
CARROLL...JACKSON...SCOTT...SOUTHEASTERN DUBUQUE...EASTERN MUSCATINE
AND CLINTON COUNTIES...

At 800 PM CDT, severe thunderstorms were located along a line
extending from near Hazel Green to near Bellevue to near DeWitt to
Andalusia, moving northeast at 70 mph.

HAZARD...70 mph wind gusts and quarter size hail. 

SOURCE...Trained weather spotters. 

IMPACT...Hail damage to vehicles is expected. Expect considerable 
         tree damage. Wind damage is also likely to mobile homes, 
         roofs, and outbuildings. 

Locations impacted include...
Davenport, Dubuque, Moline, Rock Island, Bettendorf, Clinton,
Muscatine, East Moline, Maquoketa, Galena, Durant, Silvis, Eldridge,
DeWitt, Milan, Camanche, Le Claire, Coal Valley, Savanna and
Bellevue.

This includes the following highways...
 Interstate 74 in Iowa between mile markers 1 and 5.
 Interstate 80 in Iowa between mile markers 279 and 306.
 Interstate 80 in Illinois between mile markers 1 and 4.
 Interstate 74 in Illinois between mile markers 1 and 7.
 Interstate 88 between mile markers 1 and 4.
 Interstate 280 between mile markers 1 and 18.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

&&

A tornado watch remains in effect until 1100 PM CDT for northwestern
Illinois...and southeastern, northeastern and east central Iowa.

LAT...LON 4251 8998 4181 9018 4178 9024 4170 9024
      4166 9022 4153 9026 4152 9035 4146 9043
      4144 9043 4121 9106 4125 9110 4134 9106
      4135 9110 4182 9074 4217 9080 4236 9076
      4246 9077 4252 9071
TIME...MOT...LOC 0100Z 224DEG 61KT 4256 9048 4222 9036 4183 9045 4144
9074

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...70MPH
 
$$

ERVIN

What forecasters said that day

The local office's own words before this severe thunderstorm warning 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 severe thunderstorm warning went out at May 17, 6:45 PM CDT, 29 minutes earlier.

Area forecast discussion, May 17, 6:45 PM CDT, 29 minutes before
Area Forecast Discussion
National Weather Service Quad Cities IA IL
645 PM CDT Wed May 17 2017

.UPDATE...
Issued at 645 pm CDT Wed May 17 2017

A line of severe storms with confirmed wind gusts of 60 to 70
mph, heavy rainfall and hail is moving across eastern IA with
embedded supercells possibly producing tornadoes, mainly south of
I-80. Mesoanalysis indicates the tornado potential remains,
especially along the southern portions of the line, over the next
couple hours. A tornado watch remains in effect for most of the
CWA until 11 pm.

&&

.SYNOPSIS...
Issued at 221 PM CDT Wed May 17 2017

Abbreviated early issuance AFD to get ready for convective event.
Water vapor showing neg tilted upper wave on track acrs southeastern
Neb. After potentail convective severe event this afternoon and
evening, a reprieve with cooler conditions on Thu. Then the next
main upstream large cut-off upper low will roll out to the upper
Midwest for a wet end to the week and start to the weekend.
Generally cooler Sunday into earlier next week, with another wave
digging from the northwest for another precip event toward mid next
week.

&&

.SHORT TERM...(This Evening through Thursday)
ISSUED AT 221 PM CDT Wed May 17 2017

Will have to watch for isolated to sctrd elevated storms with
hail potential ahead of the "main show" for the rest of the
afternoon, but the main severe weather event currently gathering
steam/"bubbling" in sfc pressure falls max over the MO RVR
Valley. Strong wing of lift into current mesoanalysis-indicated
already strongly sheared environment in place acrs the local area,
supportive of enhanced severe weather risk acrs the area
especially along and west of the MS RVR. Most of latest run
HiRes/CAM's continue to suggest an arching wing or two of broken
line of supercells, mixed with a few strong convective clusters,
moving rapidly at 50-60 MPH in from the west- southwest mainly
after 21z, with prime impact window from 5 PM to 8 or 9 PM CDT
before the brunt of the activity blows eastward. Again speed of
storms to complicate matters and increase danger aspect. Current
CAPEs of 1000-1500 J/KG acrs the region may increase a bit more
through early evening, while brunt of Cap/EML starts to migrate
eastward. This should be adequate for such strong shear profiles
to work with for all modes of severe weather, with tornadoes and
large hail the prime threats. But lingering concern that limited
CAPE for such strong shear profiles, may actually limit a higher
end severe weather event such as if we had 3000+ CAPEs.

The tornado threat may be limited to the initial incoming line as
long as llvl winds have some type of southeasterly direction
component, but then switch to more hail and damaging winds, as llvl
ambient environmental winds go south-southwest making for a more
uniform vertical profile, but still very high in speed shear.

Some isolated to sctrd showers and storms may linger acrs the
northern half of the CWA after the main line exits off to the east-
northeast through midnight, but then mainly dry into Thu morning or
just some wrap-around showers in the far north as upper level
cyclone pivots acrs northern WI and induces wrap-around.

Thu...after wrap around showers decrease in the north, this day
mainly dry and cooler in between two upper cyclones, with varying
amounts of cloud cover. LLVL baroclinicity aligns and tightens along
and south of the DVN CWA into the evening, with northeast post-
frontal boundary layer winds keeping temps in the 60s to low 70s
acrs much of the area.    ..12..

.LONG TERM...(Thursday Night through next Wednesday)
ISSUED AT 221 PM CDT Wed May 17 2017

Active weather pattern to continue through the period with chances
of rain and thunderstorms through the beginning of the weekend and
then again midweek next week.  Previously discussed issues with
model inconsistency still remains with this package.  This, along
with the threat for severe weather today has led to heavy use of
blended guidance for the long term.  Overall agreement in the large
scale pattern through the period means that the mesoscale details
need to be worked out and thus lead to most of uncertainty
throughout the period.   Gibbs

&&

.AVIATION...(For the 00Z TAFS through 00Z Thursday Evening)
ISSUED AT 645 PM CDT Wed May 17 2017

A line of severe thunderstorms with wind gusts to 55 kts moving
across eastern Iowa will affect the terminals early this evening.
Outside of the thunderstorms, strong south winds from 25 to 35 kts
will shift to the southwest to west and diminish to less than 15
kts by midnight behind the associated passing front. Otherwise,
conditions will be mainly VFR with a period of low confidence MVFR
ceilings possible late tonight into early Thursday morning. Winds
will become west and then northwest during the day Thursday as
surface low pressure moves into the Great Lakes.

&&

.DVN WATCHES/WARNINGS/ADVISORIES...
IA...NONE.
IL...NONE.
MO...NONE.
&&

SYNOPSIS...12
SHORT TERM...12
LONG TERM...Gibbs
AVIATION...Sheets
Hazardous weather outlook, May 17, 3:02 AM CDT, 16 hours 12 minutes before
Hazardous Weather Outlook
National Weather Service Quad Cities IA IL
302 AM CDT Wed May 17 2017

IAZ040>042-051>054-063>068-076>078-087>089-098-099-ILZ001-002-007-
009-015>018-024>026-034-035-MOZ009-010-180815-
Buchanan-Delaware-Dubuque-Benton-Linn-Jones-Jackson-Iowa-Johnson-
Cedar-Clinton-Muscatine-Scott-Keokuk-Washington-Louisa-Jefferson-
Henry IA-Des Moines-Van Buren-Lee-Jo Daviess-Stephenson-Carroll-
Whiteside-Rock Island-Henry IL-Bureau-Putnam-Mercer-Henderson-
Warren-Hancock-McDonough-Scotland-Clark-
302 AM CDT Wed May 17 2017

This Hazardous Weather Outlook is for portions of north central
Illinois...northwest Illinois...west central Illinois...east
central Iowa...northeast Iowa...southeast Iowa and northeast
Missouri.

.DAY ONE...TONIGHT

Scattered thunderstorms are expected this morning. The main
threats are lightning and hail to penny size.

More widespread thunderstorms are expected this afternoon and
evening. Fast-moving storms could produce damaging winds around 70
mph and tornadoes. A secondary threat is large hail.

A south wind will gust around 40 mph this afternoon. Drivers of
high profile vehicles should use caution.

Area rivers are experiencing flooding. Please see the
latest Flood Statements and Flood Warnings for details.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY

There is a risk of thunderstorms late Thursday night through
Saturday evening. It is too early to determine the severe weather
risk.

.SPOTTER INFORMATION STATEMENT...

Spotter activation is expected between 2 PM and 10 PM CDT today.

RP Kinney/08

In the hours before

Local storm report, May 17, 6:52 PM CDT, 22 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
652 PM CDT WED MAY 17 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0640 PM     TSTM WND GST     ANAMOSA                 42.11N 91.28W
05/17/2017  M58 MPH          JONES              IA   MESONET

            RWIS REPORT NEAR HWY 151.

&&

GROSS
Local storm report, May 17, 6:55 PM CDT, 19 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
655 PM CDT WED MAY 17 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0648 PM     HAIL             2 SSE HILLS             41.55N 91.53W
05/17/2017  E0.75 INCH       JOHNSON            IA   TRAINED SPOTTER

            PEA SIZE AND LARGER

0651 PM     TSTM WND GST     ONEIDA                  42.54N 91.35W
05/17/2017  E75.00 MPH       DELAWARE           IA   EMERGENCY MNGR

&&

TES
Local storm report, May 17, 6:58 PM CDT, 16 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
658 PM CDT WED MAY 17 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0657 PM     TSTM WND GST     SW DYERSVILLE           42.48N 91.12W
05/17/2017  M72 MPH          DUBUQUE            IA   EMERGENCY MNGR

&&

GROSS
Local storm report, May 17, 7:03 PM CDT, 11 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
703 PM CDT WED MAY 17 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0637 PM     HAIL             5 WNW MOUNT PLEASANT    40.98N 91.64W
05/17/2017  E2.00 INCH       HENRY              IA   PUBLIC

&&

GROSS
Local storm report, May 17, 7:08 PM CDT, 6 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
708 PM CDT WED MAY 17 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0704 PM     TSTM WND GST     HOLY CROSS              42.60N 91.00W
05/17/2017  M78 MPH          DUBUQUE            IA   EMERGENCY MNGR

&&

GROSS
Local storm report, May 17, 7:13 PM CDT, 1 minute before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
713 PM CDT WED MAY 17 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0713 PM     HEAVY RAIN       1 NW WILLIAMSTOWN       41.58N 91.75W
05/17/2017  M1.75 INCH       JOHNSON            IA   TRAINED SPOTTER

            RAIN IN 20 MINUTES.

&&

GROSS

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 7:00 PM CDTTornado WarningDVNHenderson, Mercer, Warren45 min
May 17, 7:30 PM CDTSevere Thunderstorm WarningDVNMercer, Rock Island45 min
May 17, 7:37 PM CDTSevere Thunderstorm WarningDVNHenry, Mercer, Rock Island, Warren38 min
May 17, 8:05 PM CDTSevere Thunderstorm WarningDVNCarroll, Jo Daviess, Stephenson, Whiteside55 min
May 17, 8:05 PM CDTTornado Warning Tornado observedDVNHenry, Mercer, Rock Island40 min
May 17, 8:08 PM CDTSevere Thunderstorm WarningDVNHenry, Mercer, Rock Island, Whiteside67 min
May 17, 8:46 PM CDTTornado WarningDVNBureau, Henry, Whiteside23 min
May 17, 9:00 PM CDTSevere Thunderstorm WarningDVNCarroll, Jo Daviess, Rock Island, Stephenson, Whiteside60 min
May 17, 9:38 PM CDTSevere Thunderstorm WarningDVNBureau, Henry52 min
May 17, 7:44 PM CDTTornado WarningDVNClinton, Scott46 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2017Severe Thunderstorm Warnings in Illinois, 2017Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.