Alert archive / Iowa / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 13, NWS Sioux Falls, SD

May 1, 20184 counties in Iowa

NWS Sioux Falls, SD issued this severe thunderstorm warning at May 1, 2018, 4:00 PM CDT for 4 counties in Iowa. It was in force for 45 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, 4:00 PM CDT (21:00 UTC)
Expired: May 1, 2018, 4:45 PM CDT
In force: 45 min
Issued by: NWS Sioux Falls, SD
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Buena Vista County, IA, Cherokee County, IA, Ida County, IA, Woodbury County, IA

The radar

The Sioux Falls radar (KFSD), 137 km from the middle of the area, began a volume at 21:01 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, 4:23 PM CDT	HAIL 1.5	3 Ne Quimby, IA
May 1, 4:36 PM CDT	HAIL 1.5	Aurelia, IA	REPORT VIA SOCIAL MEDIA WITH PICTURE. TIME ESTIMATED FROM RADAR.
May 1, 4:40 PM CDT	HAIL 1.25	Aurelia, IA	BROADCAST MEDIA RELAYED PUBLIC REPORT WITH PICTURE. TIME ESTIMATED FROM RADAR.

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, 9.0 hours before the alert went out and 160 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: 787 J/kg
Mixed-layer CIN: -48 J/kg
Mixed-layer LCL: 955 m above ground
0-6 km bulk shear: 53 kt
0-1 km storm-relative helicity: 74 m²/s²
0-3 km storm-relative helicity: 57 m²/s²
Significant tornado parameter: 0.3
Supercell composite: 2.2

Open this sounding in Storm Lab

The text

As transmitted.

349 
WUUS53 KFSD 012100
SVRFSD
IAC021-035-093-193-012145-
/O.NEW.KFSD.SV.W.0013.180501T2100Z-180501T2145Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Sioux Falls SD
400 PM CDT TUE MAY 1 2018

The National Weather Service in Sioux Falls has issued a

* Severe Thunderstorm Warning for...
  Cherokee County in northwestern Iowa...
  Northeastern Woodbury County in west central Iowa...
  Northwestern Buena Vista County in northwestern Iowa...
  Northwestern Ida County in west central Iowa...

* Until 445 PM CDT

* At 400 PM CDT, a severe thunderstorm was located over Washta, or 15
  miles southwest of Cherokee, moving northeast at 20 mph.

  HAZARD...60 mph wind gusts and quarter size hail. 

  SOURCE...Radar indicated. 

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

* This severe thunderstorm will be near, 
  Quimby around 420 PM CDT. 
  Cherokee and Aurelia around 445 PM CDT. 

Other locations impacted by this severe thunderstorm include Meriden.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4245 9573 4257 9586 4263 9586 4279 9569
      4290 9544 4277 9505
TIME...MOT...LOC 2100Z 231DEG 18KT 4258 9574 

HAIL...1.00IN
WIND...60MPH
 
$$

Maldonado

1 follow-up statement

065 
WWUS53 KFSD 012119
SVSFSD

Severe Weather Statement
National Weather Service Sioux Falls SD
419 PM CDT TUE MAY 1 2018

IAC193-012128-
/O.CAN.KFSD.SV.W.0013.000000T0000Z-180501T2145Z/
Woodbury IA-
419 PM CDT TUE MAY 1 2018

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN WOODBURY COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4252 9559 4264 9571 4267 9572 4279 9568
      4290 9544 4277 9505
TIME...MOT...LOC 2118Z 230DEG 26KT 4267 9559 

$$

IAC021-035-093-012145-
/O.CON.KFSD.SV.W.0013.000000T0000Z-180501T2145Z/
Cherokee IA-Buena Vista IA-Ida IA-
419 PM CDT TUE MAY 1 2018

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM CDT
FOR EASTERN CHEROKEE...NORTHWESTERN BUENA VISTA AND NORTH CENTRAL IDA
COUNTIES...

At 418 PM CDT, a severe thunderstorm was located near Quimby, or near
Cherokee, moving northeast at 30 mph.

HAZARD...60 mph wind gusts and quarter size hail. 

SOURCE...Radar indicated. 

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

This severe storm will be near...
  Cherokee around 430 PM CDT. 
  Aurelia around 435 PM CDT. 

Other locations impacted by this severe thunderstorm include Meriden.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4252 9559 4264 9571 4267 9572 4279 9568
      4290 9544 4277 9505
TIME...MOT...LOC 2118Z 230DEG 26KT 4267 9559 

HAIL...1.00IN
WIND...60MPH
 
$$

Maldonado

The office that day

Everything else NWS Sioux Falls, SD issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
May 1, 4:37 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Cherokee, Clay	38 min
May 1, 5:08 PM CDT	Severe Thunderstorm Warning	FSD	Buena Vista, Clay	52 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.