Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 54, NWS Des Moines, IA

September 4, 2018Kossuth County, Iowa

NWS Des Moines, IA issued this tornado warning at Sep 4, 2018, 3:46 PM CDT for Kossuth County, Iowa. It was in force for 29 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 4, 2018, 3:46 PM CDT (20:46 UTC)
Expired: Sep 4, 2018, 4:15 PM CDT
In force: 29 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Observed
Hail: 0.75 in

County Kossuth County, IA

The radar

The Des Moines radar (KDMX), 159 km from the middle of the area, began a volume at 20:46 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 watch it was issued in

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

Issued	Product	Office	Lasted
Sep 4, 3:35 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 8.8 hours before the alert went out and 203 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: 106 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 667 m above ground
0-6 km bulk shear: 38 kt
0-1 km storm-relative helicity: 45 m²/s²
0-3 km storm-relative helicity: 71 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.2

Open this sounding in Storm Lab

The text

As transmitted.

249 
WFUS53 KDMX 042046
TORDMX
IAC109-042115-
/O.NEW.KDMX.TO.W.0054.180904T2046Z-180904T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Des Moines IA
346 PM CDT TUE SEP 4 2018

The National Weather Service in Des Moines  has issued a

* Tornado Warning for...
  Southwestern Kossuth County in north central Iowa...

* Until 415 PM CDT.

* At 346 PM CDT, a confirmed tornado was located near Algona, moving
  northeast at 20 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
  southwestern Kossuth County, including the following locations...
  Algona Municipal Airport, Burt and Stinson Prairie State Park.

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 4299 9437 4303 9442 4328 9427 4318 9410
TIME...MOT...LOC 2046Z 214DEG 18KT 4311 9429 

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

$$

Lee

3 follow-up statements

239 
WWUS53 KDMX 042048
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
348 PM CDT TUE SEP 4 2018

IAC109-042115-
/O.CON.KDMX.TO.W.0054.000000T0000Z-180904T2115Z/
Kossuth IA-
348 PM CDT TUE SEP 4 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM CDT FOR CENTRAL
KOSSUTH COUNTY...
    
At 348 PM CDT, a confirmed tornado was located near Algona, moving
northeast at 20 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.

Locations impacted include...
Burt and Algona 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 4308 9428 4310 9434 4328 9427 4318 9410
TIME...MOT...LOC 2048Z 214DEG 18KT 4312 9428 

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

$$

Lee

350 
WWUS53 KDMX 042059
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
359 PM CDT TUE SEP 4 2018

IAC109-042115-
/O.CON.KDMX.TO.W.0054.000000T0000Z-180904T2115Z/
Kossuth IA-
359 PM CDT TUE SEP 4 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM CDT FOR CENTRAL
KOSSUTH COUNTY...
    
At 359 PM CDT, a confirmed tornado was located near Algona, moving
northeast at 20 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.

Locations impacted include...
Burt.

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 4310 9424 4311 9430 4327 9425 4318 9410
TIME...MOT...LOC 2059Z 214DEG 18KT 4317 9424 

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

$$

Lee

036 
WWUS53 KDMX 042111
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
411 PM CDT TUE SEP 4 2018

IAC109-042121-
/O.EXP.KDMX.TO.W.0054.000000T0000Z-180904T2115Z/
Kossuth IA-
411 PM CDT TUE SEP 4 2018

...THE TORNADO WARNING FOR CENTRAL KOSSUTH COUNTY WILL EXPIRE AT 415
PM CDT...
        
The storm which prompted the warning has weakened below severe
limits, and has exited the warned area. Therefore, the warning will
be allowed to expire.  However heavy rain is still possible with this
thunderstorm.

A Tornado Watch remains in effect until 1000 PM CDT for north central
Iowa.

LAT...LON 4310 9424 4311 9430 4327 9425 4318 9410
TIME...MOT...LOC 2111Z 214DEG 18KT 4322 9420 

$$

Lee

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 3, 7:32 PM CDT	Special Weather Statement	DMX	Black Hawk, Bremer, Grundy	88 min
Sep 3, 7:43 PM CDT	Flash Flood Warning	DMX	Black Hawk	3 hr
Sep 4, 3:33 AM CDT	Flash Flood Watch	DMX	Black Hawk, Boone, Bremer, Butler, Calhoun, Cerro Gordo and 22 more	27 hr
Sep 4, 9:34 AM CDT	River Flood Watch	DMX	Cerro Gordo, Floyd, Worth	13 hr
Sep 4, 9:34 AM CDT	River Flood Watch	DMX	Black Hawk, Bremer, Butler	25 hr
Sep 4, 2:21 PM CDT	Severe Thunderstorm Warning	DMX	Palo Alto, Pocahontas	14 min
Sep 4, 4:45 PM CDT	Tornado Warning	DMX	Hancock, Winnebago	30 min
Sep 4, 5:09 PM CDT	Flash Flood Warning	DMX	Hancock, Kossuth, Winnebago	6 hr

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.