Alert archive / Iowa / Tornado Warnings in 2015

Tornado Warning 20, NWS Des Moines, IA

July 16, 2015Story County, Iowa

NWS Des Moines, IA issued this tornado warning at Jul 16, 2015, 5:21 PM CDT for Story County, Iowa. It was in force for 18 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: Jul 16, 2015, 5:21 PM CDT (22:21 UTC)
Expired: Jul 16, 2015, 5:39 PM CDT
In force: 18 min
Issued by: NWS Des Moines, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Story County, IA

The radar

The Des Moines radar (KDMX), 30 km from the middle of the area, began a volume at 22:21 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 nearest sounding before it

Omaha, NE (KOAX), launched 12:00Z, 10.4 hours before the alert went out and 245 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: 171 J/kg
Mixed-layer CIN: -93 J/kg
Mixed-layer LCL: 791 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 115 m²/s²
0-3 km storm-relative helicity: 83 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

647 
WFUS53 KDMX 162221
TORDMX
IAC169-162300-
/O.NEW.KDMX.TO.W.0020.150716T2221Z-150716T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
521 PM CDT THU JUL 16 2015

THE NATIONAL WEATHER SERVICE IN DES MOINES  HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHWESTERN STORY COUNTY IN CENTRAL IOWA...

* UNTIL 600 PM CDT

* AT 521 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED 4 MILES SOUTHEAST OF AMES...MOVING EAST AT 15
  MPH.

  HAZARD...TORNADO. 

  SOURCE...WEATHER SPOTTERS REPORTED FUNNEL CLOUD. 

  IMPACT...EXPECT DAMAGE TO MOBILE HOMES...ROOFS AND VEHICLES. 

* THIS DANGEROUS STORM WILL BE NEAR...
  NEVADA AROUND 535 PM CDT.

OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE AMES
MUNICIPAL AIRPORT AND KELLEY.

THIS INCLUDES INTERSTATE 35 BETWEEN MILE MARKERS 108 AND 112.
 
PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 4192 9365 4199 9369 4205 9340 4195 9339
TIME...MOT...LOC 2221Z 255DEG 12KT 4198 9355 

TORNADO...RADAR INDICATED
HAIL...<.75IN

$$

REV

1 follow-up statement

990 
WWUS53 KDMX 162239
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
539 PM CDT THU JUL 16 2015

IAC169-162247-
/O.CAN.KDMX.TO.W.0020.000000T0000Z-150716T2300Z/
STORY IA-
539 PM CDT THU JUL 16 2015

...THE TORNADO WARNING FOR SOUTHWESTERN STORY COUNTY IS CANCELLED...
                
THE STORM WHICH PROMPTED THE WARNING HAS WEAKENED BELOW SEVERE
LIMITS...AND NO LONGER APPEARS CAPABLE OF PRODUCING A TORNADO.
THEREFORE THE WARNING HAS BEEN CANCELLED.

CONDITIONS REMAIN FAVORABLE FOR FUNNEL CLOUDS AND A POTENTIAL FOR AN 
ISOLATED BRIEF TORNADO OVER THIS AREA.  IF YOU SEE ANY ADDITIONAL 
FUNNEL CLOUDS...REPORT THEM TO YOUR NEAREST LAW ENFORCEMENT OFFICIAL.

IF THREATENING WEATHER APPROACHES...TAKE SHELTER IMMEDIATELY.

LAT...LON 4192 9365 4199 9369 4205 9340 4195 9339
TIME...MOT...LOC 2235Z 255DEG 12KT 4199 9348 

$$

REV

The office that day

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

Issued	Product	Office	Counties	Lasted
Jul 15, 10:12 PM CDT	Special Weather Statement	DMX	Taylor	63 min
Jul 15, 11:52 PM CDT	Flash Flood Watch	DMX	Adair, Adams, Appanoose, Audubon, Cass, Clarke and 18 more	10 hr
Jul 16, 5:44 AM CDT	Flash Flood Warning	DMX	Taylor	6 hr
Jul 16, 6:47 AM CDT	River Flood Warning	DMX	Lucas, Wayne	42 hr
Jul 16, 10:05 AM CDT	River Flood Warning	DMX	Mahaska, Wapello	52 hr
Jul 16, 10:05 AM CDT	River Flood Warning	DMX	Davis, Wapello	61 hr

Nearby

Tornado Warnings in Iowa, 2015 Every tornado warning in 2015 Tornadoes in 2015

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.