Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 25, NWS Quad Cities, IA

September 1, 2018Keokuk County, Iowa

NWS Quad Cities, IA issued this tornado warning at Sep 1, 2018, 7:52 PM CDT for Keokuk County, Iowa. It was in force for 23 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: Sep 1, 2018, 7:52 PM CDT (00:52 UTC)
Expired: Sep 1, 2018, 8:15 PM CDT
In force: 23 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.0 in

County Keokuk County, IA

The radar

The Des Moines radar (KDMX), 137 km from the middle of the area, began a volume at 00:55 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, 0.9 hours before the alert went out and 152 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: 1803 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 1189 m above ground
0-6 km bulk shear: 31 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 160 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 6.9

Open this sounding in Storm Lab

The text

As transmitted.

522 
WFUS53 KDVN 020052
TORDVN
IAC107-020115-
/O.NEW.KDVN.TO.W.0025.180902T0052Z-180902T0115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
752 PM CDT SAT SEP 1 2018

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Southern Keokuk County in southeastern Iowa...

* Until 815 PM CDT.
    
* At 752 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Martinsburg, or 9 miles south of Sigourney, moving
  east at 20 mph.

  HAZARD...Tornado and quarter size hail.

  SOURCE...Radar indicated rotation.

  IMPACT...Flying debris will be dangerous to those caught without 
           shelter. Mobile homes will be damaged or destroyed. 
           Damage to roofs, windows, and vehicles will occur.  Tree 
           damage is likely.

* Locations impacted include...
  Hedrick, Martinsburg, Ollie and Pekin. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4123 9237 4127 9205 4116 9203 4116 9235
TIME...MOT...LOC 0052Z 259DEG 18KT 4120 9227 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Uttech

2 follow-up statements

841 
WWUS53 KDVN 020057
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
757 PM CDT SAT SEP 1 2018

IAC107-020115-
/O.CON.KDVN.TO.W.0025.000000T0000Z-180902T0115Z/
Keokuk IA-
757 PM CDT SAT SEP 1 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR
SOUTHEASTERN KEOKUK COUNTY...
    
At 757 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Martinsburg, or 9 miles south of Sigourney, moving
east at 20 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Martinsburg, Ollie and Pekin. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4123 9230 4127 9205 4116 9203 4116 9228
TIME...MOT...LOC 0057Z 264DEG 19KT 4119 9222 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Uttech

556 
WWUS53 KDVN 020105
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
805 PM CDT SAT SEP 1 2018

IAC107-020115-
/O.CON.KDVN.TO.W.0025.000000T0000Z-180902T0115Z/
Keokuk IA-
805 PM CDT SAT SEP 1 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 815 PM CDT FOR
SOUTHEASTERN KEOKUK COUNTY...
    
At 804 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Martinsburg, or 9 miles south of Sigourney, moving
east at 25 mph.

HAZARD...Tornado and quarter size hail.

SOURCE...Radar indicated rotation.

IMPACT...Flying debris will be dangerous to those caught without 
         shelter. Mobile homes will be damaged or destroyed. Damage 
         to roofs, windows, and vehicles will occur.  Tree damage is 
         likely.

Locations impacted include...
Martinsburg, Ollie and Pekin. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TAKE COVER NOW! Move to a basement or an interior room on the lowest
floor of a sturdy building. Avoid windows. If you are outdoors, in a
mobile home, or in a vehicle, move to the closest substantial shelter
and protect yourself from flying debris.

&&

LAT...LON 4123 9228 4127 9205 4116 9203 4116 9225
TIME...MOT...LOC 0104Z 249DEG 20KT 4120 9220 

TORNADO...RADAR INDICATED
HAIL...1.00IN

$$

Uttech

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 1, 7:32 PM CDT	Special Weather Statement	DVN	Keokuk	28 min
Sep 1, 7:39 PM CDT	Severe Thunderstorm Warning	DVN	Keokuk	36 min
Sep 1, 8:14 PM CDT	Severe Thunderstorm Warning	DVN	Jefferson, Keokuk	46 min
Sep 1, 8:23 PM CDT	Severe Thunderstorm Warning	DVN	Keokuk	37 min
Sep 1, 8:56 PM CDT	Special Weather Statement	DVN	Washington	49 min
Sep 1, 9:05 PM CDT	Severe Thunderstorm Warning	DVN	Henry, Jefferson, Washington	40 min
Sep 1, 9:08 PM CDT	Severe Thunderstorm Warning	DVN	Henry, Jefferson, Washington	52 min
Sep 1, 9:22 PM CDT	Severe Thunderstorm Warning	DVN	Jefferson	38 min
Sep 1, 9:52 PM CDT	Special Weather Statement	DVN	Iowa	53 min
Sep 1, 9:56 PM CDT	Special Weather Statement	DVN	Louisa	49 min
Sep 1, 10:04 PM CDT	Special Weather Statement	DVN	Washington	26 min
Sep 1, 10:08 PM CDT	Flash Flood Warning	DVN	Keokuk	5 hr
Sep 1, 11:20 PM CDT	Flash Flood Warning	DVN	Iowa, Keokuk, Washington	4 hr
Sep 1, 11:29 PM CDT	Special Weather Statement	DVN	Scott	46 min
Sep 1, 11:50 PM CDT	Special Weather Statement	DVN	Dubuque	25 min
Sep 2, 9:26 AM CDT	Flash Flood Watch	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	39 hr
Sep 2, 9:53 AM CDT	River Flood Warning	DVN	Cedar, Jones, Linn	11 days
Sep 2, 10:22 AM CDT	River Flood Warning	DVN	Louisa	16 days
Sep 2, 10:22 AM CDT	River Flood Warning	DVN	Des Moines, Louisa	16 days
Sep 2, 10:22 AM CDT	River Flood Warning	DVN	Des Moines	17 days
Sep 2, 10:22 AM CDT	River Flood Warning	DVN	Des Moines, Lee	17 days
Sep 2, 2:39 PM CDT	Special Weather Statement	DVN	Buchanan	111 min
Sep 2, 3:01 PM CDT	Severe Thunderstorm Warning	DVN	Buchanan, Delaware	44 min
Sep 2, 3:41 PM CDT	Tornado Warning	DVN	Delaware, Dubuque	22 min
Sep 2, 4:31 PM CDT	Special Weather Statement	DVN	Dubuque	74 min
Sep 2, 5:32 PM CDT	Special Weather Statement	DVN	Jones	43 min
Sep 2, 6:18 PM CDT	Special Weather Statement	DVN	Jackson	42 min
Sep 2, 6:25 PM CDT	Special Weather Statement	DVN	Cedar, Muscatine, Scott, Washington	50 min
Sep 2, 6:48 PM CDT	Special Weather Statement	DVN	Jefferson, Van Buren	42 min

Nearby

Tornado Warnings in Iowa, 2018 Every tornado warning in 2018 Tornadoes 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.