Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 59, NWS Des Moines, IA

October 8, 2018Boone County, Dallas County, Greene County, Iowa

NWS Des Moines, IA issued this tornado warning at Oct 8, 2018, 6:55 PM CDT for Boone County, Dallas County, Greene County, Iowa. It was in force for 24 min. 1 report 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: Oct 8, 2018, 6:55 PM CDT (23:55 UTC)
Expired: Oct 8, 2018, 7:19 PM CDT
In force: 24 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Observed
Hail: 0.75 in

Counties Boone County, IA, Dallas County, IA, Greene County, IA

The radar

The Des Moines radar (KDMX), 34 km from the middle of the area, began a volume at 23:58 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

Time	Report	Where	Remark
Oct 8, 6:57 PM CDT	TORNADO	1 Nne Perry, IA	CONFIRMED TORNADO ON GROUND WEST OF HWY 169.

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

The nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 11.9 hours before the alert went out and 210 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: 0 J/kg
Mixed-layer CIN: No buoyant parcel
Mixed-layer LCL: 457 m above ground
0-6 km bulk shear: 40 kt
0-1 km storm-relative helicity: 97 m²/s²
0-3 km storm-relative helicity: 101 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

243 
WFUS53 KDMX 082355
TORDMX
IAC015-049-073-090030-
/O.NEW.KDMX.TO.W.0059.181008T2355Z-181009T0030Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
655 PM CDT MON OCT 8 2018

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Southeastern Greene County in west central Iowa...
  Southeastern Boone County in central Iowa...
  Northern Dallas County in central Iowa...

* Until 730 PM CDT.
    
* At 654 PM CDT, a tornado producing storm was located near Perry,
  moving northeast at 35 mph.

  HAZARD...Damaging tornado.

  SOURCE...Radar confirmed tornado.

  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.

* This tornadic storm will be near...
  Ogden around 705 PM CDT.
  Boone Speedway around 715 PM CDT.
  Boone around 720 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Berkley, Ledges State Park and Boone Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

To repeat, a tornado is on the ground. 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 4185 9408 4191 9420 4214 9388 4203 9373
TIME...MOT...LOC 2354Z 224DEG 30KT 4192 9405 

TORNADO...OBSERVED
HAIL...<.75IN

$$

REV

2 follow-up statements

111 
WWUS53 KDMX 090016
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
716 PM CDT MON OCT 8 2018

IAC049-073-090026-
/O.CAN.KDMX.TO.W.0059.000000T0000Z-181009T0030Z/
Greene IA-Dallas IA-
716 PM CDT MON OCT 8 2018

...THE TORNADO WARNING FOR SOUTHEASTERN GREENE AND NORTHERN DALLAS
COUNTIES IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. **! Therefore, the warning has been cancelled.

LAT...LON 4194 9393 4203 9401 4214 9388 4203 9373
TIME...MOT...LOC 0016Z 224DEG 30KT 4205 9388 

$$

IAC015-090030-
/O.CON.KDMX.TO.W.0059.000000T0000Z-181009T0030Z/
Boone IA-
716 PM CDT MON OCT 8 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 730 PM CDT FOR CENTRAL
BOONE COUNTY...
    
At 716 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Boone, moving northeast at 35 mph.

HAZARD...Tornado.

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.

This tornadic thunderstorm will remain over mainly rural areas of
central Boone County, including the following locations... Ledges
State Park and Boone Municipal Airport.

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 4194 9393 4203 9401 4214 9388 4203 9373
TIME...MOT...LOC 0016Z 224DEG 30KT 4205 9388 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

REV

098 
WWUS53 KDMX 090019
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
719 PM CDT MON OCT 8 2018

IAC015-090029-
/O.CAN.KDMX.TO.W.0059.000000T0000Z-181009T0030Z/
Boone IA-
719 PM CDT MON OCT 8 2018

...THE TORNADO WARNING FOR CENTRAL BOONE COUNTY IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning has been cancelled.

LAT...LON 4194 9393 4203 9401 4214 9388 4203 9373
TIME...MOT...LOC 0019Z 224DEG 30KT 4207 9385 

$$

REV

The office that day

Everything else NWS Des Moines, IA issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Oct 7, 10:05 PM CDT	River Flood Watch	DMX	Wright	6 days
Oct 7, 10:05 PM CDT	River Flood Watch	DMX	Boone, Hamilton, Webster	54 hr
Oct 7, 10:05 PM CDT	River Flood Watch	DMX	Palo Alto, Pocahontas	24 hr
Oct 7, 10:05 PM CDT	River Flood Watch	DMX	Dallas, Polk	37 hr
Oct 7, 10:05 PM CDT	River Flood Watch	DMX	Cerro Gordo, Floyd, Worth	4 days
Oct 7, 10:05 PM CDT	River Flood Watch	DMX	Black Hawk, Bremer, Butler	36 hr
Oct 8, 10:40 AM CDT	Areal Flood Warning	DMX	Appanoose, Lucas, Mahaska, Marion, Monroe, Wayne	24 hr
Oct 8, 11:38 AM CDT	River Flood Warning	DMX	Tama	8 days
Oct 8, 11:38 AM CDT	River Flood Warning	DMX	Black Hawk	9 days
Oct 8, 11:38 AM CDT	River Flood Warning	DMX	Black Hawk	6 days
Oct 8, 11:38 AM CDT	River Flood Warning	DMX	Webster	4 days
Oct 8, 11:38 AM CDT	River Flood Warning	DMX	Davis, Wapello	91 min
Oct 8, 11:38 AM CDT	River Flood Warning	DMX	Humboldt	5 days
Oct 8, 11:39 AM CDT	River Flood Watch	DMX	Davis, Wapello	4 days
Oct 8, 6:12 PM CDT	Severe Thunderstorm Warning	DMX	Carroll, Dallas, Greene, Guthrie	48 min
Oct 8, 6:14 PM CDT	Severe Thunderstorm Warning	DMX	Appanoose, Wayne	46 min
Oct 8, 6:29 PM CDT	Tornado Warning	DMX	Boone, Dallas, Greene, Guthrie	31 min
Oct 8, 6:35 PM CDT	Severe Thunderstorm Warning	DMX	Decatur, Ringgold	40 min
Oct 8, 6:36 PM CDT	Tornado Warning	DMX	Appanoose	24 min
Oct 8, 6:47 PM CDT	Tornado Warning	DMX	Decatur, Ringgold	43 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.