Alert archive / Iowa / Tornado Warnings in 2015

Tornado Warning 6, NWS Quad Cities, IA

April 9, 2015Clinton County, Scott County, Iowa

NWS Quad Cities, IA issued this tornado warning at Apr 9, 2015, 5:24 PM CDT for Clinton County, Scott County, Iowa. It was in force for 36 min. 8 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: Apr 9, 2015, 5:24 PM CDT (22:24 UTC)
Expired: Apr 9, 2015, 6:00 PM CDT
In force: 36 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 1.75 in

Counties Clinton County, IA, Scott County, IA

The radar

The Quad Cities radar (KDVN), 25 km from the middle of the area, began a volume at 22:25 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
Apr 9, 5:25 PM CDT	TSTM WND GST 60	4 N Long Grove, IA
Apr 9, 5:28 PM CDT	TSTM WND DMG	Dewitt, IA	DEWITT TRAVEL MART ON HIGHWAY 30 JUST EAST OF DEWITT HAD THE SIGN SEVERELY DAMAGED. POSSIBLE TORNADO.
Apr 9, 5:28 PM CDT	TSTM WND GST 70	Dewitt, IA	70 MPH WINDS.
Apr 9, 5:28 PM CDT	HAIL 1	Dewitt, IA	A COUPLE OF QUARTER SIZE HAIL BUT MOSTLY DIME TO NICKEL.
Apr 9, 5:28 PM CDT	HAIL 2	Dewitt, IA
Apr 9, 5:30 PM CDT	TSTM WND DMG	Dewitt, IA	SEMI BLOWN OVER ON HIGHWAY 61 JUST SOUTH OF DEWITT.
Apr 9, 5:34 PM CDT	TSTM WND GST 70	Dewitt, IA	SUSTAINED 40 MPH WITH GUSTS TO 70
Apr 9, 5:34 PM CDT	HAIL 2	Dewitt, IA	1 1/2 INCH TO 2 INCH DIAMETER HAIL

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
Apr 9, 12:58 PM CDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 10.4 hours before the alert went out and 23 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: 101 J/kg
Mixed-layer CIN: -154 J/kg
Mixed-layer LCL: 614 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 323 m²/s²
0-3 km storm-relative helicity: 253 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 1.4

Open this sounding in Storm Lab

The text

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

431 
WFUS53 KDVN 092224
TORDVN
IAC045-163-092300-
/O.NEW.KDVN.TO.W.0006.150409T2224Z-150409T2300Z/

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
524 PM CDT THU APR 9 2015

THE NATIONAL WEATHER SERVICE IN THE QUAD CITIES HAS ISSUED A

* TORNADO WARNING FOR...
  SOUTH CENTRAL CLINTON COUNTY IN EAST CENTRAL IOWA...
  NORTH CENTRAL SCOTT COUNTY IN EAST CENTRAL IOWA...

* UNTIL 600 PM CDT

* AT 522 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A
  TORNADO WAS LOCATED NEAR GRAND MOUND...AND MOVING NORTHEAST AT 45
  MPH.

  HAZARD...TORNADO AND GOLF BALL SIZE HAIL.

  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...
  DEWITT AROUND 530 PM CDT.
  LOW MOOR AROUND 540 PM CDT.

OTHER LOCATIONS IN THE WARNING INCLUDE MALONE.

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.

THIS STORM HAS A HISTORY OF PRODUCING TORNADOES. TAKE COVER IN A
BASEMENT OR STORM SHELTER NOW!

&&

LAT...LON 4194 9040 4179 9034 4170 9063 4178 9073
TIME...MOT...LOC 2225Z 235DEG 39KT 4178 9061

TORNADO...RADAR INDICATED
HAIL...1.75IN

$$

MM

2 follow-up statements

259 
WWUS53 KDVN 092230
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
530 PM CDT THU APR 9 2015

IAC045-163-092300-
/O.CON.KDVN.TO.W.0006.000000T0000Z-150409T2300Z/
SCOTT IA-CLINTON IA-
530 PM CDT THU APR 9 2015

...A TORNADO WARNING REMAINS IN EFFECT FOR SOUTH CENTRAL CLINTON AND
NORTH CENTRAL SCOTT COUNTIES UNTIL 600 PM CDT...

AT 528 PM CDT...A CONFIRMED TORNADO WAS LOCATED NEAR DEWITT...AND
MOVING EAST AT 50 MPH.

HAZARD...DAMAGING TORNADO AND PING PONG BALL SIZE HAIL.

SOURCE...RADAR CONFIRMED TORNADO.

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...
  LOW MOOR AROUND 540 PM CDT.

OTHER LOCATIONS IN THE WARNING INCLUDE MALONE.

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.

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW.

THIS STORM HAS A HISTORY OF PRODUCING TORNADOES. TAKE COVER IN A
BASEMENT OR STORM SHELTER NOW!

&&

LAT...LON 4194 9040 4179 9034 4170 9063 4178 9073
TIME...MOT...LOC 2230Z 248DEG 45KT 4180 9051

TORNADO...OBSERVED
HAIL...1.50IN

$$

MM/DC

179 
WWUS53 KDVN 092240
SVSDVN

SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE QUAD CITIES IA IL
540 PM CDT THU APR 9 2015

IAC163-092250-
/O.CAN.KDVN.TO.W.0006.000000T0000Z-150409T2300Z/
SCOTT IA-
540 PM CDT THU APR 9 2015

...THE TORNADO WARNING FOR NORTH CENTRAL SCOTT COUNTY IS CANCELLED...

THE STORM WHICH PROMPTED THE WARNING HAS MOVED OUT OF THE WARNED 
AREA.

LAT...LON 4194 9040 4179 9034 4177 9055 4185 9058
TIME...MOT...LOC 2240Z 246DEG 33KT 4183 9042

$$

IAC045-092300-
/O.CON.KDVN.TO.W.0006.000000T0000Z-150409T2300Z/
CLINTON IA-
540 PM CDT THU APR 9 2015

...A TORNADO WARNING REMAINS IN EFFECT FOR CENTRAL CLINTON COUNTY
UNTIL 600 PM CDT...

AT 538 PM CDT...A SEVERE THUNDERSTORM CAPABLE OF PRODUCING A TORNADO
WAS LOCATED NEAR LOW MOOR...AND MOVING NORTHEAST AT 40 MPH.

HAZARD...TORNADO AND PING PONG BALL SIZE HAIL.

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...
  LOW MOOR AROUND 545 PM CDT.

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.

HEAVY RAINFALL MAY HIDE THIS TORNADO. DO NOT WAIT TO SEE OR HEAR THE
TORNADO. TAKE COVER NOW.

THIS STORM HAS A HISTORY OF PRODUCING TORNADOES. TAKE COVER IN A
BASEMENT OR STORM SHELTER NOW!

&&

LAT...LON 4194 9040 4179 9034 4177 9055 4185 9058
TIME...MOT...LOC 2240Z 246DEG 33KT 4183 9042

TORNADO...RADAR INDICATED
HAIL...1.50IN

$$

MM

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 8, 8:46 PM CDT	Special Weather Statement	DVN	Lee	44 min
Apr 9, 12:00 AM CDT	Special Weather Statement	DVN	Buchanan	30 min
Apr 9, 3:11 PM CDT	Special Weather Statement	DVN	Keokuk	34 min
Apr 9, 3:19 PM CDT	Severe Thunderstorm Warning	DVN	Keokuk	26 min
Apr 9, 3:39 PM CDT	Tornado Warning	DVN	Keokuk, Washington	36 min
Apr 9, 3:57 PM CDT	Special Weather Statement	DVN	Van Buren	48 min
Apr 9, 4:06 PM CDT	Special Weather Statement	DVN	Dubuque	9 min
Apr 9, 4:14 PM CDT	Severe Thunderstorm Warning	DVN	Cedar, Johnson, Louisa, Muscatine, Washington	46 min
Apr 9, 4:19 PM CDT	Special Weather Statement	DVN	Linn	41 min
Apr 9, 4:27 PM CDT	Special Weather Statement	DVN	Henry, Lee	48 min
Apr 9, 4:32 PM CDT	Severe Thunderstorm Warning	DVN	Des Moines, Henry, Lee	43 min
Apr 9, 4:35 PM CDT	Flash Flood Warning	DVN	Linn	6 hr
Apr 9, 5:00 PM CDT	Severe Thunderstorm Warning	DVN	Cedar, Clinton, Muscatine, Scott	45 min
Apr 9, 5:06 PM CDT	Tornado Warning	DVN	Scott	24 min
Apr 9, 5:41 PM CDT	Special Weather Statement	DVN	Dubuque	64 min
Apr 9, 5:45 PM CDT	Severe Thunderstorm Warning	DVN	Dubuque	30 min
Apr 9, 5:49 PM CDT	Tornado Warning Tornado observedConsiderable damage threat	DVN	Clinton	26 min
Apr 9, 6:39 PM CDT	Special Weather Statement	DVN	Des Moines, Henry, Iowa, Jefferson, Johnson, Keokuk and 6 more	2 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.