Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 66, NWS Des Moines, IA

October 9, 2018Poweshiek County, Tama County, Iowa

NWS Des Moines, IA issued this tornado warning at Oct 9, 2018, 4:21 PM CDT for Poweshiek County, Tama County, Iowa. It was in force for 24 min. 3 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: Oct 9, 2018, 4:21 PM CDT (21:21 UTC)
Expired: Oct 9, 2018, 4:45 PM CDT
In force: 24 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Observed
Hail: 0.0 in

Counties Poweshiek County, IA, Tama County, IA

The radar

The Des Moines radar (KDMX), 109 km from the middle of the area, began a volume at 21:25 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 9, 4:21 PM CDT	TORNADO	7 Wsw Chelsea, IA	TORNADO REPORTED OFF TO THE NORTH NORTHEAST FROM THE MM 186 ON I-80 IN POWESHIEK COUNTY.
Oct 9, 4:41 PM CDT	FUNNEL CLOUD	4 E Tama, IA	EM REPORTS PRIVATE CITIZENS SAW TWO FUNNEL CLOUDS FOR A FEW MINUTES.
Oct 9, 4:55 PM CDT	TORNADO	3 Nw Vining, IA	EM RELAYED THE REPORT FROM LAW ENFORCEMENT.

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

The watch it was issued in

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

Issued	Product	Office	Lasted
Oct 9, 1:46 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 9.4 hours before the alert went out and 164 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: 459 J/kg
Mixed-layer CIN: -49 J/kg
Mixed-layer LCL: 1071 m above ground
0-6 km bulk shear: 35 kt
0-1 km storm-relative helicity: 82 m²/s²
0-3 km storm-relative helicity: 116 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted.

905 
WFUS53 KDMX 092121
TORDMX
IAC157-171-092145-
/O.NEW.KDMX.TO.W.0066.181009T2121Z-181009T2145Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
421 PM CDT TUE OCT 9 2018

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  North central Poweshiek County in central Iowa...
  Southeastern Tama County in central Iowa...

* Until 445 PM CDT.

* At 421 PM CDT, a confirmed tornado was located 7 miles southeast of
  Tama, or 9 miles southeast of Toledo, moving northeast at 25 mph.

  HAZARD...Damaging tornado.

  SOURCE...Weather spotters 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 thunderstorm will remain over mainly rural areas of
  north central Poweshiek and southeastern Tama Counties, including
  the following locations... Chelsea, Elberon and Vining.

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 4183 9247 4184 9255 4205 9250 4205 9230
      4200 9230
TIME...MOT...LOC 2121Z 204DEG 22KT 4187 9250 

TORNADO...OBSERVED
HAIL...0.00IN

$$

Martin

2 follow-up statements

122 
WWUS53 KDMX 092127
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
427 PM CDT TUE OCT 9 2018

IAC157-092136-
/O.CAN.KDMX.TO.W.0066.000000T0000Z-181009T2145Z/
Poweshiek IA-
427 PM CDT TUE OCT 9 2018

...THE TORNADO WARNING FOR NORTH CENTRAL POWESHIEK COUNTY IS
CANCELLED...
    
The tornadic thunderstorm which prompted the warning has moved out 
of the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 900 PM CDT for central Iowa.

LAT...LON 4186 9244 4186 9254 4205 9250 4205 9230
      4200 9230
TIME...MOT...LOC 2126Z 204DEG 22KT 4190 9248 

$$

IAC171-092145-
/O.CON.KDMX.TO.W.0066.000000T0000Z-181009T2145Z/
Tama IA-
427 PM CDT TUE OCT 9 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 PM CDT FOR
SOUTHEASTERN TAMA COUNTY...
    
At 426 PM CDT, a confirmed tornado was located 7 miles southwest of 
Chelsea , or 8 miles southeast of Toledo, moving northeast at 25 mph.

HAZARD...Damaging tornado.

SOURCE...Law enforcement 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.

Locations impacted include...
Chelsea, Elberon and Vining. 

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 4186 9244 4186 9254 4205 9250 4205 9230
      4200 9230
TIME...MOT...LOC 2126Z 204DEG 22KT 4190 9248 

TORNADO...OBSERVED
HAIL...0.00IN

$$

Martin

518 
WWUS53 KDMX 092143
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
443 PM CDT TUE OCT 9 2018

IAC171-092153-
/O.EXP.KDMX.TO.W.0066.000000T0000Z-181009T2145Z/
Tama IA-
443 PM CDT TUE OCT 9 2018

...THE TORNADO WARNING FOR SOUTHEASTERN TAMA COUNTY WILL EXPIRE AT
445 PM CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.

A Tornado Watch remains in effect until 900 PM CDT for central Iowa.

LAT...LON 4186 9244 4186 9254 4205 9250 4205 9230
      4200 9230
TIME...MOT...LOC 2143Z 204DEG 22KT 4199 9243 

$$

Martin

The office that day

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

Issued	Product	Office	Counties	Lasted
Oct 8, 7:11 PM CDT	Severe Thunderstorm Warning	DMX	Decatur, Wayne	34 min
Oct 8, 7:23 PM CDT	Tornado Warning	DMX	Clarke, Decatur	37 min
Oct 8, 7:59 PM CDT	Tornado Warning Tornado observed	DMX	Clarke, Lucas, Warren	31 min
Oct 8, 9:54 PM CDT	Severe Thunderstorm Warning	DMX	Mahaska, Poweshiek	21 min
Oct 8, 10:03 PM CDT	Tornado Warning	DMX	Poweshiek	15 min
Oct 8, 10:26 PM CDT	River Flood Warning	DMX	Polk	7 days
Oct 8, 10:26 PM CDT	River Flood Warning	DMX	Polk	7 days
Oct 8, 10:31 PM CDT	River Flood Watch	DMX	Decatur	3 hr
Oct 9, 12:58 AM CDT	River Flood Warning	DMX	Decatur	4 days
Oct 9, 1:48 AM CDT	Areal Flood Warning	DMX	Clarke, Decatur, Jasper, Lucas, Mahaska, Marion and 6 more	24 hr
Oct 9, 2:49 AM CDT	River Flood Warning	DMX	Polk, Story	3 days
Oct 9, 6:39 AM CDT	River Flood Warning	DMX	Marshall	7 days
Oct 9, 6:39 AM CDT	River Flood Warning	DMX	Black Hawk	6 days
Oct 9, 6:39 AM CDT	River Flood Warning	DMX	Dallas, Greene	5 days
Oct 9, 10:20 AM CDT	River Flood Warning	DMX	Black Hawk, Bremer, Butler	35 hr
Oct 9, 10:20 AM CDT	River Flood Warning	DMX	Lucas, Wayne	64 hr
Oct 9, 11:33 AM CDT	River Flood Warning	DMX	Dallas, Polk	6 days
Oct 9, 12:38 PM CDT	River Flood Watch	DMX	Davis, Wapello	10 hr
Oct 9, 2:16 PM CDT	Tornado Warning	DMX	Mahaska, Marion, Monroe	29 min
Oct 9, 3:22 PM CDT	River Flood Warning	DMX	Story	7 hr
Oct 9, 3:22 PM CDT	River Flood Warning	DMX	Story	20 hr
Oct 9, 3:32 PM CDT	Tornado Warning	DMX	Appanoose, Monroe	43 min
Oct 9, 3:42 PM CDT	Tornado Warning	DMX	Mahaska, Marion, Monroe	22 min
Oct 9, 4:28 PM CDT	Tornado Warning	DMX	Ringgold, Taylor	47 min
Oct 9, 4:47 PM CDT	River Flood Watch	DMX	Jasper, Marion, Polk	29 hr
Oct 9, 4:58 PM CDT	Tornado Warning Tornado observed	DMX	Tama	32 min
Oct 9, 4:59 PM CDT	Tornado Warning	DMX	Jasper, Poweshiek	31 min
Oct 9, 5:13 PM CDT	Tornado Warning	DMX	Adair, Adams, Union	32 min
Oct 9, 5:44 PM CDT	Tornado Warning Tornado observed	DMX	Adair	46 min
Oct 9, 6:11 PM CDT	Tornado Warning Tornado observed	DMX	Adair, Dallas, Guthrie	49 min
Oct 9, 6:30 PM CDT	Tornado Warning	DMX	Polk, Warren	30 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.