Alert archive / Iowa / Tornado Warnings in 2015

Tornado Warning 8, NWS Des Moines, IA

May 17, 2015Boone County, Webster County, Iowa

NWS Des Moines, IA issued this tornado warning at May 17, 2015, 4:03 AM CDT for Boone County, Webster County, Iowa. It was in force for 21 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
May 17, 2015, 4:03 AM CDT (09:03 UTC)
Expired
May 17, 2015, 4:24 AM CDT
In force
21 min
Issued by
NWS Des Moines, IA
Area
Storm-based polygon
Tornado
Observed
Hail
0.0 in

Counties Boone County, IA, Webster County, IA

The nearest sounding before it

Omaha, NE (KOAX), launched 00:00Z, 9.1 hours before the alert went out and 218 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-pSkew-T log-p diagram, Omaha, NE at 00:00Z on 2015-05-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Omaha, NE at 00:00Z on 2015-05-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 37 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
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
1511 m above ground
0-6 km bulk shear
39 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
73 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.

821 
WFUS53 KDMX 170903
TORDMX
IAC015-187-170945-
/O.NEW.KDMX.TO.W.0008.150517T0903Z-150517T0945Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE DES MOINES IA
403 AM CDT SUN MAY 17 2015

THE NATIONAL WEATHER SERVICE IN DES MOINES  HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTHEASTERN WEBSTER COUNTY IN CENTRAL IOWA...
  NORTHWESTERN BOONE COUNTY IN CENTRAL IOWA...

* UNTIL 445 AM CDT

* AT 401 AM CDT...A CONFIRMED TORNADO WAS JUST WEST OF OGDEN AND IS 
  NOW LOCATED 8 MILES NORTH OF OGDEN...OR 12 MILES NORTHWEST OF 
  BOONE...MOVING NORTH AT 40 MPH.

  HAZARD...DAMAGING TORNADO. 

  SOURCE...BOONE COUNTY EMERGENCY MANAGER CONFIRMED A TORNADO JUST 
           WEST OF OGDEN. 

  IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
           SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. 
           DAMAGE TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE 
           DAMAGE IS LIKELY. 

* THE TORNADO WILL BE NEAR...
  FORT DODGE AROUND 445 AM CDT.

OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE
DOLLIVER MEMORIAL STATE PARK...DUNCOMBE...LEHIGH...WOODMAN HOLLOW
STATE PARK...BRUSHY CREEK ST RECREATION AREA...DAYTON...PILOT
MOUND...HARCOURT...BOXHOLM AND OTHO.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TO REPEAT...A TORNADO IS ON THE GROUND. 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.

TORNADOES ARE EXTREMELY DIFFICULT TO SEE AND CONFIRM AT NIGHT. DO NOT
WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.

TO REPORT SEVERE WEATHER CONTACT YOUR NEAREST LAW ENFORCEMENT AGENCY.
THEY WILL SEND YOUR REPORT TO THE NATIONAL WEATHER SERVICE OFFICE IN
DES MOINES .

&&

LAT...LON 4210 9398 4209 9412 4251 9427 4254 9398
TIME...MOT...LOC 0901Z 175DEG 34KT 4216 9406 

TORNADO...OBSERVED
HAIL...0.00IN

$$

BOKSA
2 follow-up statements
051 
WWUS53 KDMX 170919
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
419 AM CDT SUN MAY 17 2015

IAC015-170928-
/O.CAN.KDMX.TO.W.0008.000000T0000Z-150517T0945Z/
BOONE IA-
419 AM CDT SUN MAY 17 2015

...THE TORNADO WARNING FOR NORTHWESTERN BOONE COUNTY IS CANCELLED...
    
THE TORNADIC THUNDERSTORM WHICH PROMPTED THE WARNING HAS MOVED OUT 
OF THE WARNED AREA. THEREFORE THE WARNING HAS BEEN CANCELLED.

LAT...LON 4223 9398 4223 9417 4251 9427 4254 9398
TIME...MOT...LOC 0918Z 175DEG 34KT 4233 9408 

$$

IAC187-170945-
/O.CON.KDMX.TO.W.0008.000000T0000Z-150517T0945Z/
WEBSTER IA-
419 AM CDT SUN MAY 17 2015

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 445 AM CDT FOR
SOUTHEASTERN WEBSTER COUNTY...
    
AT 418 AM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED 11 MILES EAST OF GOWRIE...OR 13 MILES SOUTH OF FORT
DODGE...AND IS NEARLY STATIONARY.

HAZARD...TORNADO. 

SOURCE...RADAR INDICATED ROTATION. 

IMPACT...FLYING DEBRIS WILL BE DANGEROUS TO THOSE CAUGHT WITHOUT 
         SHELTER. MOBILE HOMES WILL BE DAMAGED OR DESTROYED. DAMAGE 
         TO ROOFS...WINDOWS AND VEHICLES WILL OCCUR.  TREE DAMAGE IS 
         LIKELY. 

THIS DANGEROUS STORM WILL BE NEAR...
  FORT DODGE AROUND 445 AM CDT.

OTHER LOCATIONS IMPACTED BY THIS TORNADIC THUNDERSTORM INCLUDE
DOLLIVER MEMORIAL STATE PARK...DUNCOMBE...LEHIGH...WOODMAN HOLLOW
STATE PARK...BRUSHY CREEK ST RECREATION AREA...DAYTON...HARCOURT...
OTHO AND COALVILLE.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

TORNADOES ARE EXTREMELY DIFFICULT TO SEE AND CONFIRM AT NIGHT. DO NOT
WAIT TO SEE OR HEAR THE TORNADO. TAKE COVER NOW.

IF A TORNADO OR OTHER SEVERE WEATHER IS SPOTTED...REPORT IT TO THE
NATIONAL WEATHER SERVICE OR YOUR LOCAL NEAREST LAW ENFORCEMENT AGENCY
WHO WILL SEND YOUR REPORT. THIS ACT MAY SAVE LIVES OF OTHERS IN THE
PATH OF DANGEROUS WEATHER.

&&

LAT...LON 4223 9398 4223 9417 4251 9427 4254 9398
TIME...MOT...LOC 0918Z 175DEG 34KT 4233 9408 

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

$$

BOKSA
706 
WWUS53 KDMX 170924
SVSDMX

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE DES MOINES IA
424 AM CDT SUN MAY 17 2015

IAC187-170933-
/O.CAN.KDMX.TO.W.0008.000000T0000Z-150517T0945Z/
WEBSTER IA-
424 AM CDT SUN MAY 17 2015

...THE TORNADO WARNING FOR SOUTHEASTERN WEBSTER 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.

TO REPORT SEVERE WEATHER...CONTACT YOUR NEAREST LAW ENFORCEMENT
AGENCY. THEY WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE
DES MOINES .

LAT...LON 4223 9398 4223 9417 4251 9427 4254 9398
TIME...MOT...LOC 0921Z 175DEG 34KT 4239 9409 

$$

BOKSA

The office that day

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

IssuedProductOfficeCountiesLasted
May 17, 3:11 AM CDTSevere Thunderstorm WarningDMXBoone, Dallas, Greene49 min
May 17, 3:13 AM CDTTornado WarningDMXDallas32 min
May 17, 3:26 AM CDTSpecial Weather StatementDMXJasper, Mahaska, Marshall, Poweshiek, Story, Tama49 min
May 17, 3:30 AM CDTTornado WarningDMXBoone, Dallas30 min

Nearby

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