Alert archive / Iowa / Tornado Warnings in 2018

Tornado Warning 30, NWS Quad Cities, IA

September 5, 2018Lee County, Iowa

NWS Quad Cities, IA issued this tornado warning at Sep 5, 2018, 2:27 PM CDT for Lee County, Iowa. It was in force for 22 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
Sep 5, 2018, 2:27 PM CDT (19:27 UTC)
Expired
Sep 5, 2018, 2:49 PM CDT
In force
22 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon
Tornado
Radar indicated
Hail
0.75 in

County Lee County, IA

The radar

The Quad Cities radar (KDVN), 144 km from the middle of the area, began a volume at 19:30 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

Davenport, (KDVN), launched 12:00Z, 7.5 hours before the alert went out and 149 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, Davenport, at 12:00Z on 2018-09-05Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 152 joules per kilogram.LCLLFCEL10008507005003002001001 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, Davenport, at 12:00Z on 2018-09-05The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 22 square meters per square second.193958Sfc1 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
152 J/kg
Mixed-layer CIN
-61 J/kg
Mixed-layer LCL
981 m above ground
0-6 km bulk shear
17 kt
0-1 km storm-relative helicity
22 m²/s²
0-3 km storm-relative helicity
30 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

842 
WFUS53 KDVN 051927
TORDVN
IAC111-052000-
/O.NEW.KDVN.TO.W.0030.180905T1927Z-180905T2000Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
227 PM CDT WED SEP 5 2018

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Northwestern Lee County in southeastern Iowa...

* Until 300 PM CDT.
    
* At 226 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Croton, or 10 miles north of Kahoka, moving east
  at 15 mph.

  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...
  Donnellson around 255 PM CDT.
  Montrose, Franklin and New Boston around 300 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Charleston, Pollmiller Park, Wilson Lake, Lee County Fairgrounds,
Shimek State Forest, Argyle and Battle of Athens Campground.

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 4054 9162 4055 9168 4056 9169 4058 9169
      4060 9172 4063 9172 4072 9143 4053 9141
      4053 9162
TIME...MOT...LOC 1926Z 255DEG 13KT 4057 9167 

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

$$

Sheets
2 follow-up statements
199 
WWUS53 KDVN 051941
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
241 PM CDT WED SEP 5 2018

IAC111-052000-
/O.CON.KDVN.TO.W.0030.000000T0000Z-180905T2000Z/
Lee IA-
241 PM CDT WED SEP 5 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 300 PM CDT FOR
NORTHWESTERN LEE COUNTY...
    
At 241 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Donnellson, or 11 miles west of Nauvoo, moving east
at 15 mph.

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...
  Donnellson around 250 PM CDT.
  Franklin and New Boston around 300 PM CDT.

Other locations impacted by this tornadic thunderstorm include
Charleston, Wilson Lake, Lee County Fairgrounds and Pollmiller Park.

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.

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 4056 9162 4059 9165 4064 9161 4072 9143
      4056 9141 4055 9160
TIME...MOT...LOC 1941Z 255DEG 13KT 4058 9160 

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

$$

Sheets
224 
WWUS53 KDVN 051949
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
249 PM CDT WED SEP 5 2018

IAC111-051958-
/O.CAN.KDVN.TO.W.0030.000000T0000Z-180905T2000Z/
Lee IA-
249 PM CDT WED SEP 5 2018

...THE TORNADO WARNING FOR NORTHWESTERN LEE 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.  However heavy rain is
still possible with this thunderstorm.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
the Quad Cities.

LAT...LON 4056 9162 4059 9165 4064 9161 4072 9143
      4056 9141 4055 9160
TIME...MOT...LOC 1947Z 255DEG 13KT 4059 9157 

$$

Sheets

The office that day

Everything else NWS Quad Cities, IA issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Sep 5, 12:36 PM CDTSpecial Weather StatementDVNJohnson69 min
Sep 5, 1:01 PM CDTFlash Flood WarningDVNBenton, Iowa, Johnson, Linn6 hr
Sep 5, 3:50 PM CDTRiver Flood WarningDVNJohnson, Louisa, Washington4 days
Sep 5, 3:50 PM CDTRiver Flood WarningDVNJohnson, Washington5 days

Nearby

Tornado Warnings in Iowa, 2018Every tornado warning in 2018Tornadoes 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.