Alert archive / Iowa / Tornado Warnings in 2020

Tornado Warning 8, NWS Quad Cities, IA

March 28, 2020Jones County, Linn County, Iowa

NWS Quad Cities, IA issued this tornado warning at Mar 28, 2020, 7:20 PM CDT for Jones County, Linn County, Iowa. It was in force for 25 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: Mar 28, 2020, 7:20 PM CDT (00:20 UTC)
Expired: Mar 28, 2020, 7:45 PM CDT
In force: 25 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

Counties Jones County, IA, Linn County, IA

The radar

The Quad Cities radar (KDVN), 74 km from the middle of the area, began a volume at 00:23 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.

Issued	Product	Office	Lasted
Mar 28, 2:45 PM CDT	Tornado Watch PDS	SPC	6 hr

The nearest sounding before it

Davenport, (KDVN), launched 00:00Z, 0.3 hours before the alert went out and 79 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: 504 J/kg
Mixed-layer CIN: -27 J/kg
Mixed-layer LCL: 963 m above ground
0-6 km bulk shear: 88 kt
0-1 km storm-relative helicity: 480 m²/s²
0-3 km storm-relative helicity: 520 m²/s²
Significant tornado parameter: 1.7
Supercell composite: 9.3

Open this sounding in Storm Lab

The text

As transmitted.

130 
WFUS53 KDVN 290020
TORDVN
IAC105-113-290045-
/O.NEW.KDVN.TO.W.0008.200329T0020Z-200329T0045Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
720 PM CDT Sat Mar 28 2020

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Central Jones County in east central Iowa...
  East central Linn County in east central Iowa...

* Until 745 PM CDT.
    
* At 720 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Martelle, or 7 miles southwest of Anamosa, moving
  northeast at 45 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...
  Morley around 725 PM CDT.
  Anamosa around 730 PM CDT.
  Center Junction and Langworthy around 740 PM CDT.
  Monticello around 745 PM CDT.

Other locations impacted by this tornadic thunderstorm include Camp
Courageous, Scotch Grove, Central Park, Pictured Rocks Wildlife Area,
Wapsipinicon State Park, Temple Hill and Monticello Municipal
Airport.

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 4222 9091 4195 9134 4195 9136 4193 9137
      4191 9140 4199 9147 4230 9112 4230 9105
TIME...MOT...LOC 0020Z 224DEG 37KT 4202 9136 

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

$$

Ervin

2 follow-up statements

006 
WWUS53 KDVN 290031
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
731 PM CDT Sat Mar 28 2020

IAC113-290040-
/O.CAN.KDVN.TO.W.0008.000000T0000Z-200329T0045Z/
Linn IA-
731 PM CDT Sat Mar 28 2020

...THE TORNADO WARNING FOR EAST CENTRAL LINN COUNTY IS CANCELLED...
    
The tornadic thunderstorm which prompted the warning moved out of 
the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 900 PM CDT for northeastern
and east central Iowa.

LAT...LON 4222 9091 4195 9134 4195 9136 4209 9136
      4230 9112 4230 9104
TIME...MOT...LOC 0030Z 226DEG 36KT 4210 9128 

$$

IAC105-290045-
/O.CON.KDVN.TO.W.0008.000000T0000Z-200329T0045Z/
Jones IA-
731 PM CDT Sat Mar 28 2020

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 745 PM CDT FOR CENTRAL
JONES COUNTY...
    
At 730 PM CDT, a severe thunderstorm capable of producing a tornado
was located over Anamosa, moving northeast at 40 mph.

HAZARD...Tornado.

SOURCE...Radar indicated rotation. A rotating wall cloud was seen by 
         spotters just west of Anamosa at 730 PM.

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...
  Center Junction and Langworthy around 740 PM CDT.
  Monticello around 745 PM CDT.

Other locations impacted by this tornadic thunderstorm include Camp
Courageous, Scotch Grove, Central Park, Pictured Rocks Wildlife Area,
Wapsipinicon State Park, Temple Hill and Monticello Municipal
Airport.

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 4222 9091 4195 9134 4195 9136 4209 9136
      4230 9112 4230 9104
TIME...MOT...LOC 0030Z 226DEG 36KT 4210 9128 

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

$$

Ervin

475 
WWUS53 KDVN 290037
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
737 PM CDT Sat Mar 28 2020

IAC105-290045-
/O.EXP.KDVN.TO.W.0008.000000T0000Z-200329T0045Z/
Jones IA-
737 PM CDT Sat Mar 28 2020

...THE TORNADO WARNING FOR CENTRAL JONES COUNTY WILL EXPIRE AT 745 PM
CDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer appears capable of producing a tornado.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

A Tornado Watch remains in effect until 900 PM CDT for northeastern
and east central Iowa.

LAT...LON 4222 9091 4195 9134 4195 9136 4209 9136
      4230 9112 4230 9104
TIME...MOT...LOC 0035Z 224DEG 37KT 4212 9125 

$$

Ervin

The office that day

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

Issued	Product	Office	Counties	Lasted
Mar 28, 7:49 PM CDT	Tornado Warning	DVN	Delaware, Dubuque, Jones	26 min
Mar 28, 9:26 PM CDT	Wind Advisory	DVN	Benton, Buchanan, Cedar, Clinton, Delaware, Des Moines and 15 more	22 hr
Mar 29, 10:35 AM CDT	River Flood Warning	DVN	Louisa	34 hr

Nearby

Tornado Warnings in Iowa, 2020 Every tornado warning in 2020 Tornadoes in 2020

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.