Alert archive / Iowa / Tornado Warnings in 2009

Tornado Warning 7, NWS Quad Cities, IA

April 26, 2009Dubuque County, Iowa

NWS Quad Cities, IA issued this tornado warning at Apr 26, 2009, 6:27 PM CDT for Dubuque 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
Apr 26, 2009, 6:27 PM CDT (23:27 UTC)
Expired
Apr 26, 2009, 6:45 PM CDT
In force
18 min
Issued by
NWS Quad Cities, IA
Area
Storm-based polygon

County Dubuque County, IA

The radar

The Quad Cities radar (KDVN), 119 km from the middle of the area, began a volume at 23:27 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Apr 26, 5:02 PM CDTTornado WatchSPC6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 11.5 hours before the alert went out and 119 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 2009-04-26Temperature 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°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Davenport, at 12:00Z on 2009-04-26The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 402 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
586 m above ground
0-6 km bulk shear
35 kt
0-1 km storm-relative helicity
402 m²/s²
0-3 km storm-relative helicity
403 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.3

Open this sounding in Storm Lab

The text

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

000 
WFUS53 KDVN 262327
TORDVN
IAC061-262345-
/O.NEW.KDVN.TO.W.0007.090426T2327Z-090426T2345Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
627 PM CDT SUN APR 26 2009

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  NORTH CENTRAL DUBUQUE COUNTY IN NORTHEAST IOWA...

* UNTIL 645 PM CDT.

* AT 625 PM CDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  TORNADO NEAR OLD BALLTOWN...OR 14 MILES NORTHWEST OF DUBUQUE...
  MOVING NORTHEAST AT 30 MPH.

* THE TORNADO WILL BE NEAR...
  BALLTOWN AND OLD BALLTOWN AROUND 630 PM CDT...
  WAUPETON AROUND 635 PM CDT...
  SPECHTS FERRY AROUND 645 PM CDT...

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THE SAFEST PLACE TO BE IN A TORNADO IS IN A BASEMENT OR INTERIOR ROOM
OR HALLWAY ON THE LOWEST FLOOR OF A BUILDING.

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT MONDAY MORNING
FOR EASTERN IOWA AND NORTHWEST ILLINOIS.

&&

LAT...LON 4268 9083 4267 9082 4267 9078 4265 9073
      4259 9088 4263 9095 4265 9094 4265 9090
      4267 9090 4269 9089
TIME...MOT...LOC 2328Z 227DEG 25KT 4264 9091

$$

SHEETS
1 follow-up statement
000 
WWUS53 KDVN 262344
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
644 PM CDT SUN APR 26 2009

IAC061-262352-
/O.EXP.KDVN.TO.W.0007.000000T0000Z-090426T2345Z/
DUBUQUE IA-
644 PM CDT SUN APR 26 2009

...THE TORNADO WARNING FOR NORTH CENTRAL DUBUQUE COUNTY WILL EXPIRE
AT 645 PM CDT...

THE SEVERE THUNDERSTORM THAT WAS CAPABLE OF PRODUCING A TORNADO HAS 
MOVED OUT DUBUQUE COUNTY INTO WISCONSIN. THEREFORE THE TORNADO 
WARNING WILL BE ALLOWED TO EXPIRE.

A TORNADO WATCH REMAINS IN EFFECT UNTIL MIDNIGHT CDT MONDAY MORNING
FOR EASTERN IOWA AND NORTHWEST ILLINOIS.

LAT...LON 4268 9083 4267 9082 4267 9078 4265 9073
      4259 9088 4263 9095 4265 9094 4265 9090
      4267 9090 4269 9089
TIME...MOT...LOC 2342Z 227DEG 25KT 4270 9082

$$

SHEETS

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 25, 8:25 PM CDTSpecial Weather StatementDVNHenry, Jefferson, Washington50 min
Apr 25, 9:32 PM CDTSpecial Weather StatementDVNBenton, Buchanan, Delaware, Dubuque, Jackson, Jones and 1 more58 min
Apr 25, 9:45 PM CDTSpecial Weather StatementDVNCedar, Clinton, Des Moines, Henry, Lee, Louisa and 2 more90 min
Apr 26, 2:20 AM CDTSpecial Weather StatementDVNBenton, Buchanan, Cedar, Delaware, Dubuque, Iowa and 4 more3 hr
Apr 26, 3:04 AM CDTFlash Flood WatchDVNBenton, Buchanan, Cedar, Clinton, Delaware, Dubuque and 8 more24 hr
Apr 26, 4:32 AM CDTSpecial Weather StatementDVNClinton, Scott118 min
Apr 26, 4:34 AM CDTSpecial Weather StatementDVNClinton, Scott116 min
Apr 26, 9:49 AM CDTRiver Flood WarningDVNJones, Linn5 days
Apr 26, 9:49 AM CDTRiver Flood WarningDVNClinton, Scott10 days
Apr 26, 9:56 AM CDTRiver Flood WarningDVNKeokuk6 days
Apr 26, 10:01 AM CDTRiver Flood WarningDVNLee35 hr
Apr 26, 10:52 AM CDTRiver Flood WarningDVNIowa, Johnson12 days
Apr 26, 4:14 PM CDTSpecial Weather StatementDVNBenton, Buchanan, Cedar, Delaware, Johnson, Jones and 1 more61 min
Apr 26, 4:41 PM CDTSevere Thunderstorm WarningDVNBuchanan, Delaware, Linn23 min
Apr 26, 4:52 PM CDTTornado WarningDVNDelaware, Linn23 min
Apr 26, 5:12 PM CDTTornado WarningDVNDelaware, Dubuque, Jones, Linn48 min
Apr 26, 5:48 PM CDTTornado WarningDVNDelaware, Dubuque42 min
Apr 26, 6:30 PM CDTFlash Flood WarningDVNDelaware5 hr

Nearby

Tornado Warnings in Iowa, 2009Every tornado warning in 2009Tornadoes in 2009

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.