Alert archive / Iowa / Tornado Warnings in 2013
Tornado Warning 7, NWS Des Moines, IA
NWS Des Moines, IA issued this tornado warning at May 20, 2013, 7:10 PM CDT for Polk County, Story County, Iowa. It was in force for 35 min. 5 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, 7:10 PM CDT (00:10 UTC)
- Expired
- May 20, 2013, 7:45 PM CDT
- In force
- 35 min
- Issued by
- NWS Des Moines, IA
- Area
- Storm-based polygon
- Tornado
- Radar indicated
- Hail
- 1.0 in
Counties Polk County, IA, Story County, IA
The radar
The Des Moines radar (KDMX), 17 km from the middle of the area, began a volume at 00:11 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, 7:11 PM CDT | FUNNEL CLOUD | Ankeny, IA | THREE SEPARATE HAM RADIO OPERATORS REPORTED A ROTATING FUNNEL CLOUD WHICH LASTED FOR ABOUT 10 MINUTES. |
| May 20, 7:14 PM CDT | HAIL 0.88 | Ankeny, IA | |
| May 20, 7:16 PM CDT | HAIL 1 | 4 Nnw Ankeny Airport, IA | |
| May 20, 7:19 PM CDT | HAIL 1.75 | 5 Nw Ankeny Airport, IA | |
| May 20, 7:33 PM CDT | HAIL 1 | 4 Sw Maxwell, IA | NICKEL TO QUARTER SIZE HAIL AT INTERSECTION OF 620TH AVE AND 340TH ST. |
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
Omaha, NE (KOAX), launched 00:00Z, 0.2 hours before the alert went out and 239 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
- 10 J/kg
- Mixed-layer CIN
- -14 J/kg
- Mixed-layer LCL
- 1953 m above ground
- 0-6 km bulk shear
- 18 kt
- 0-1 km storm-relative helicity
- 46 m²/s²
- 0-3 km storm-relative helicity
- 120 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.2
The text
As transmitted, in the capitals the NWS used until 2016.
152
WFUS53 KDMX 210010
TORDMX
IAC153-169-210045-
/O.NEW.KDMX.TO.W.0007.130521T0010Z-130521T0045Z/
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
710 PM CDT MON MAY 20 2013
THE NATIONAL WEATHER SERVICE IN DES MOINES HAS ISSUED A
* TORNADO WARNING FOR...
NORTHERN POLK COUNTY IN CENTRAL IOWA...
SOUTH CENTRAL STORY COUNTY IN CENTRAL IOWA...
* UNTIL 745 PM CDT
* AT 706 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
TORNADO WAS LOCATED NEAR POLK CITY...AND MOVING NORTHEAST AT 25
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...
ANKENY...HUXLEY...ALLEMAN...ELKHART AND CAMBRIDGE.
THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 93 AND 109.
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 4197 9357 4180 9335 4169 9365 4177 9376
TIME...MOT...LOC 0010Z 227DEG 22KT 4176 9366
TORNADO...RADAR INDICATED
HAIL...1.00IN
$$
AWB2 follow-up statements
230
WWUS53 KDMX 210025
SVSDMX
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
725 PM CDT MON MAY 20 2013
IAC153-169-210045-
/O.CON.KDMX.TO.W.0007.000000T0000Z-130521T0045Z/
STORY IA-POLK IA-
725 PM CDT MON MAY 20 2013
...A TORNADO WARNING REMAINS IN EFFECT FOR NORTHEASTERN POLK AND
SOUTH CENTRAL STORY COUNTIES UNTIL 745 PM CDT...
AT 724 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED 6 MILES SOUTH OF HUXLEY...AND MOVING NORTHEAST AT 25 MPH.
HAZARD...DEVELOPING TORNADO AND QUARTER SIZE HAIL.
SOURCE...RADAR INDICATED ROTATION.
IMPACT...MOBILE HOMES WILL BE HEAVILY DAMAGED OR DESTROYED.
SIGNIFICANT DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL
OCCUR. FLYING DEBRIS WILL BE DEADLY TO PEOPLE AND ANIMALS.
EXTENSIVE TREE DAMAGE IS LIKELY.
LOCATIONS IMPACTED INCLUDE...
HUXLEY...ELKHART AND CAMBRIDGE.
THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 93 AND 109.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
TAKE COVER NOW. MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A
STURDY BUILDING. AVOID WINDOWS. IF IN A MOBILE HOME...A VEHICLE OR
OUTDOORS...MOVE TO THE CLOSEST SUBSTANTIAL SHELTER AND PROTECT
YOURSELF FROM FLYING DEBRIS.
&&
LAT...LON 4172 9357 4186 9365 4197 9357 4180 9335
TIME...MOT...LOC 0025Z 227DEG 22KT 4182 9357
TORNADO...RADAR INDICATED
HAIL...1.00IN
$$
AWB916 WWUS53 KDMX 210042 SVSDMX SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE DES MOINES IA 742 PM CDT MON MAY 20 2013 IAC153-169-210052- /O.EXP.KDMX.TO.W.0007.000000T0000Z-130521T0045Z/ STORY IA-POLK IA- 742 PM CDT MON MAY 20 2013 ...THE TORNADO WARNING FOR NORTHEASTERN POLK AND SOUTH CENTRAL STORY COUNTIES WILL EXPIRE AT 745 PM CDT... THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED AREA. HOWEVER SMALL HAIL...GUSTY WINDS AND HEAVY RAIN ARE STILL POSSIBLE WITH THIS THUNDERSTORM. ADDITIONAL STORMS ARE POSSIBLE ACROSS THE AREA. IN ADDITION...STRONG THUNDERSTORMS MAY REDEVELOP...AND A SEVERE THUNDERSTORM WATCH REMAINS IN EFFECT UNTIL 1 AM. LAT...LON 4172 9357 4186 9365 4197 9357 4180 9335 TIME...MOT...LOC 0042Z 227DEG 22KT 4189 9347 $$ AWB
The office that day
Everything else NWS Des Moines, IA issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 7:24 PM CDT | Tornado Warning | DMX | Hardin, Marshall, Story | 36 min |
| May 20, 7:39 PM CDT | Tornado Warning | DMX | Jasper, Marshall, Polk, 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.