Alert archive / Iowa / Tornado Warnings in 2013
Tornado Warning 9, NWS Des Moines, IA
NWS Des Moines, IA issued this tornado warning at May 20, 2013, 7:39 PM CDT for 4 counties in Iowa. It was in force for 36 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 20, 2013, 7:39 PM CDT (00:39 UTC)
- Expired
- May 20, 2013, 8:15 PM CDT
- In force
- 36 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 1.0 in
Counties Jasper County, IA, Marshall County, IA, Polk County, IA, Story County, IA
The radar
The Des Moines radar (KDMX), 45 km from the middle of the area, began a volume at 00:41 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 20, 7:40 PM CDT | HAIL 1.75 | Maxwell, IA | QUARTER SIZE HAIL STARTED AT 738 PM. |
| May 20, 7:48 PM CDT | FUNNEL CLOUD | 1 S Collins, IA | ROTATING FUNNEL CLOUD OBSERVED TO THE NORTH NEAR COLLINS. DUST STIRRED UP AT THE GROUND BELOW THE FUNNEL...BUT ROTATION IN THE DUST WAS NOT OBSERVED. LASTED ABOUT 20 SECONDS BEFORE DISSIPATING. |
| May 20, 8:15 PM CDT | TSTM WND GST 60 | 3 N State Center, IA | PEA SIZE HAIL AS WELL. |
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 |
|---|---|---|---|
| May 20, 6:35 PM CDT | Severe Thunderstorm Watch | SPC | 5 hr |
The nearest sounding before it
Davenport, (KDVN), launched 00:00Z, 0.7 hours before the alert went out and 235 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.
- Mixed-layer CAPE
- 195 J/kg
- Mixed-layer CIN
- -189 J/kg
- Mixed-layer LCL
- 1801 m above ground
- 0-6 km bulk shear
- 53 kt
- 0-1 km storm-relative helicity
- 101 m²/s²
- 0-3 km storm-relative helicity
- 106 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 1.9
The text
As transmitted, in the capitals the NWS used until 2016.
558
WFUS53 KDMX 210039
TORDMX
IAC099-127-153-169-210115-
/O.NEW.KDMX.TO.W.0009.130521T0039Z-130521T0115Z/
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
739 PM CDT MON MAY 20 2013
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
* TORNADO WARNING FOR...
NORTHWESTERN JASPER COUNTY IN CENTRAL IOWA...
SOUTHWESTERN MARSHALL COUNTY IN CENTRAL IOWA...
NORTHEASTERN POLK COUNTY IN CENTRAL IOWA...
SOUTHEASTERN STORY COUNTY IN CENTRAL IOWA...
* UNTIL 815 PM CDT
* AT 736 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO WAS LOCATED 10 MILES EAST OF HUXLEY...AND MOVING NORTHEAST
AT 40 MPH.
HAZARD...DEVELOPING TORNADO AND QUARTER SIZE HAIL.
SOURCE...RADAR INDICATED ROTATION.
IMPACT...MOBILE HOMES WILL BE HEAVILY DAMAGED OR DESTROYED.
SIGNIFICANT DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL
OCCUR. FLYING DEBRIS WILL BE DEADLY TO PEOPLE AND ANIMALS.
EXTENSIVE TREE DAMAGE IS LIKELY.
* LOCATIONS IMPACTED INCLUDE...
STATE CENTER...COLLINS...RHODES...COLO AND MELBOURNE.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.
&&
LAT...LON 4213 9327 4197 9302 4177 9335 4190 9354
TIME...MOT...LOC 0039Z 221DEG 35KT 4188 9338
TORNADO...RADAR INDICATED
HAIL...1.00IN
$$
AWB2 follow-up statements
495
WWUS53 KDMX 210056
SVSDMX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
756 PM CDT MON MAY 20 2013
IAC153-210106-
/O.CAN.KDMX.TO.W.0009.000000T0000Z-130521T0115Z/
POLK IA-
756 PM CDT MON MAY 20 2013
...THE TORNADO WARNING FOR NORTHEASTERN POLK COUNTY IS CANCELLED...
THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED
AREA.
LAT...LON 4213 9327 4197 9302 4181 9329 4196 9347
TIME...MOT...LOC 0056Z 221DEG 35KT 4201 9323
$$
IAC099-127-169-210115-
/O.CON.KDMX.TO.W.0009.000000T0000Z-130521T0115Z/
STORY IA-MARSHALL IA-JASPER IA-
756 PM CDT MON MAY 20 2013
...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHWESTERN JASPER...
SOUTHWESTERN MARSHALL AND SOUTHEASTERN STORY COUNTIES UNTIL 815 PM
CDT...
AT 754 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED NEAR STATE CENTER...AND MOVING NORTHEAST AT 40 MPH.
HAZARD...DEVELOPING TORNADO AND QUARTER SIZE HAIL.
SOURCE...RADAR INDICATED ROTATION.
IMPACT...MOBILE HOMES WILL BE HEAVILY DAMAGED OR DESTROYED.
SIGNIFICANT DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL
OCCUR. FLYING DEBRIS WILL BE DEADLY TO PEOPLE AND ANIMALS.
EXTENSIVE TREE DAMAGE IS LIKELY.
LOCATIONS IMPACTED INCLUDE...
STATE CENTER AND MELBOURNE.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.
&&
LAT...LON 4213 9327 4197 9302 4181 9329 4196 9347
TIME...MOT...LOC 0056Z 221DEG 35KT 4201 9323
TORNADO...RADAR INDICATED
HAIL...1.00IN
$$
AWB374 WWUS53 KDMX 210107 SVSDMX SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 807 PM CDT MON MAY 20 2013 IAC099-127-169-210117- /O.EXP.KDMX.TO.W.0009.000000T0000Z-130521T0115Z/ STORY IA-MARSHALL IA-JASPER IA- 807 PM CDT MON MAY 20 2013 ...THE TORNADO WARNING FOR NORTHWESTERN JASPER...SOUTHWESTERN MARSHALL AND SOUTHEASTERN STORY COUNTIES WILL EXPIRE AT 815 PM CDT... THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE LIMITS...AND NO LONGER POSES AN IMMEDIATE THREAT TO LIFE OR PROPERTY. HOWEVER SMALL HAIL...GUSTY WINDS AND HEAVY RAIN ARE STILL POSSIBLE WITH THIS THUNDERSTORM. IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1 AM. LAT...LON 4213 9327 4197 9302 4181 9329 4196 9347 TIME...MOT...LOC 0107Z 221DEG 35KT 4209 9313 $$ AWB
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 7:10 PM CDT | Tornado Warning | DMX | Polk, Story | 35 min |
| May 20, 7:24 PM CDT | Tornado Warning | DMX | Hardin, Marshall, Story | 36 min |
| May 20, 7:59 PM CDT | Severe Thunderstorm Warning | DMX | Grundy, Hardin, Marshall, Story | 31 min |
| May 20, 8:13 PM CDT | Severe Thunderstorm Warning | DMX | Grundy, Marshall, Tama | 32 min |
| May 20, 8:21 PM CDT | Severe Thunderstorm Warning | DMX | Madison, Warren | 24 min |
| May 20, 8:22 PM CDT | Severe Thunderstorm Warning | DMX | Decatur | 38 min |
| May 20, 8:26 PM CDT | Severe Thunderstorm Warning | DMX | Black Hawk, Butler, Grundy, Hardin | 49 min |
| May 20, 8:35 PM CDT | Severe Thunderstorm Warning | DMX | Franklin | 25 min |
| May 20, 8:45 PM CDT | Severe Thunderstorm Warning | DMX | Jasper, Marion, Polk, Warren | 30 min |
| May 20, 9:11 PM CDT | Severe Thunderstorm Warning | DMX | Clarke, Decatur, Lucas, Wayne | 34 min |
| May 20, 9:14 PM CDT | Severe Thunderstorm Warning | DMX | Marshall, Tama | 31 min |
Nearby
Tornado Warnings in Iowa, 2013Every tornado warning in 2013Tornadoes in 2013
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.