Alert archive / Iowa / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 21, NWS Des Moines, IA

May 1, 2018Palo Alto County, Pocahontas County, Iowa

NWS Des Moines, IA issued this severe thunderstorm warning at May 1, 2018, 5:29 PM CDT for Palo Alto County, Pocahontas County, Iowa. It was in force for 46 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: May 1, 2018, 5:29 PM CDT (22:29 UTC)
Expired: May 1, 2018, 6:15 PM CDT
In force: 46 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Hail: 1.25 in
Wind: 60.0 mph

Counties Palo Alto County, IA, Pocahontas County, IA

The radar

The Des Moines radar (KDMX), 162 km from the middle of the area, began a volume at 22:32 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
May 1, 5:30 PM CDT	HAIL 1.25	Laurens, IA	RELAYED VIA COUNTY SHERIFF.
May 1, 5:46 PM CDT	HAIL 1.75	1 Ene Laurens, IA	REPORT VIA SOCIAL MEDIA.
May 1, 5:54 PM CDT	HAIL 1.5	Laurens, IA	LARGE HAIL COVERING THE GROUND.

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

The nearest sounding before it

Minneapolis, MN (KMPX), launched 12:00Z, 10.5 hours before the alert went out and 219 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: 1106 m above ground
0-6 km bulk shear: 59 kt
0-1 km storm-relative helicity: -62 m²/s²
0-3 km storm-relative helicity: 10 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

576 
WUUS53 KDMX 012229
SVRDMX
IAC147-151-012315-
/O.NEW.KDMX.SV.W.0021.180501T2229Z-180501T2315Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Des Moines IA
529 PM CDT TUE MAY 1 2018

The National Weather Service in Des Moines  has issued a

* Severe Thunderstorm Warning for...
  Northern Pocahontas County in northwestern Iowa...
  Palo Alto County in northwestern Iowa...

* Until 615 PM CDT.

* At 529 PM CDT, a severe thunderstorm was located over Rush Lake, or
  15 miles northwest of Pocahontas, moving northeast at 35 mph.

  HAZARD...60 mph wind gusts and half dollar size hail. 

  SOURCE...Radar indicated. 

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees. 

* Locations impacted include...
  Emmetsburg, Laurens, Rush Lake, Five Island Lake, West Bend,
  Mallard, Ayrshire, Havelock, Cylinder, Plover, Curlew, Rodman and
  Emmetsburg Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

&&

LAT...LON 4324 9445 4288 9444 4276 9491 4300 9491
TIME...MOT...LOC 2229Z 245DEG 29KT 4292 9484 

HAIL...1.25IN
WIND...60MPH
 
$$

Small

3 follow-up statements

343 
WWUS53 KDMX 012239
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
539 PM CDT TUE MAY 1 2018

IAC147-151-012315-
/O.CON.KDMX.SV.W.0021.000000T0000Z-180501T2315Z/
Pocahontas IA-Palo Alto IA-
539 PM CDT TUE MAY 1 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CDT
FOR NORTHERN POCAHONTAS AND SOUTHEASTERN PALO ALTO COUNTIES...

At 539 PM CDT, a severe thunderstorm was located near Rush Lake, or
14 miles southwest of Emmetsburg, moving northeast at 25 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees. 

Locations impacted include...
Emmetsburg, Laurens, Rush Lake, West Bend, Mallard, Havelock,
Cylinder, Plover, Curlew, Rodman and Emmetsburg Municipal Airport.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

&&

LAT...LON 4324 9445 4288 9444 4276 9491 4299 9491
TIME...MOT...LOC 2239Z 246DEG 21KT 4293 9480 

HAIL...1.75IN
WIND...60MPH
 
$$

Small

769 
WWUS53 KDMX 012248
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
548 PM CDT TUE MAY 1 2018

IAC147-151-012315-
/O.CON.KDMX.SV.W.0021.000000T0000Z-180501T2315Z/
Pocahontas IA-Palo Alto IA-
548 PM CDT TUE MAY 1 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 615 PM CDT
FOR NORTHERN POCAHONTAS AND SOUTHERN PALO ALTO COUNTIES...

At 548 PM CDT, a severe thunderstorm was located 7 miles northeast of
Laurens, or 10 miles north of Pocahontas, moving east at 35 mph.

HAZARD...Golf ball size hail and 60 mph wind gusts. 

SOURCE...Radar indicated. 

IMPACT...People and animals outdoors will be injured. Expect hail 
         damage to roofs, siding, windows, and vehicles. Expect wind 
         damage to roofs, siding, and trees. 

Locations impacted include...
Laurens, Rush Lake, West Bend, Mallard, Havelock, Plover, Curlew and
Rodman.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

This storm is producing large hail. SEEK SHELTER NOW inside a sturdy
structure and stay away from windows.

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

&&

LAT...LON 4310 9445 4288 9444 4276 9491 4294 9491
TIME...MOT...LOC 2248Z 263DEG 31KT 4289 9472 

HAIL...1.75IN
WIND...60MPH
 
$$

Small

206 
WWUS53 KDMX 012312
SVSDMX

Severe Weather Statement
National Weather Service Des Moines IA
612 PM CDT TUE MAY 1 2018

IAC147-151-012320-
/O.EXP.KDMX.SV.W.0021.000000T0000Z-180501T2315Z/
Pocahontas IA-Palo Alto IA-
612 PM CDT TUE MAY 1 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN POCAHONTAS AND
SOUTHERN PALO ALTO COUNTIES WILL EXPIRE AT 615 PM CDT...
        
The storm which prompted the original warning has moved out of the 
area. Therefore this warning will be allowed to expire.  However 
hail is still possible with this thunderstorm.

Remember, a Severe Thunderstorm Warning still remains in effect for 
portions of northeastern Pocahontas and southeast Palo Alto Counties 
until 645 pm.

A severe thunderstorm watch also remains in effect until 200 AM CDT 
for north central and northwestern Iowa.

LAT...LON 4310 9445 4288 9444 4276 9491 4294 9491
TIME...MOT...LOC 2310Z 245DEG 29KT 4296 9452 

$$

Small

The office that day

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

Issued	Product	Office	Counties	Lasted
May 1, 4:31 AM CDT	Special Weather Statement	DMX	Carroll, Greene, Guthrie	59 min
May 1, 9:42 AM CDT	Special Weather Statement	DMX	Warren	33 min
May 1, 11:48 AM CDT	Special Weather Statement	DMX	Jasper	27 min
May 1, 4:35 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Dallas, Story	40 min
May 1, 5:09 PM CDT	Severe Thunderstorm Warning	DMX	Boone, Story	51 min
May 1, 5:11 PM CDT	Severe Thunderstorm Warning	DMX	Kossuth, Winnebago	32 min
May 1, 5:24 PM CDT	Severe Thunderstorm Warning	DMX	Butler, Cerro Gordo, Franklin, Wright	33 min
May 1, 5:31 PM CDT	Severe Thunderstorm Warning	DMX	Winnebago, Worth	44 min
May 1, 5:54 PM CDT	Severe Thunderstorm Warning	DMX	Marshall, Story	36 min
May 1, 6:05 PM CDT	Severe Thunderstorm Warning	DMX	Humboldt, Kossuth, Palo Alto, Pocahontas	40 min
May 1, 6:24 PM CDT	Severe Thunderstorm Warning	DMX	Marshall, Tama	36 min
May 1, 6:40 PM CDT	Severe Thunderstorm Warning	DMX	Hancock, Humboldt, Kossuth, Wright	50 min

Nearby

Severe Thunderstorm Warnings in Iowa, 2018 Every severe thunderstorm warning 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.