Alert archive / Illinois / Tornado Warnings in 2018

Tornado Warning 37, NWS Quad Cities, IA

September 25, 2018Whiteside County, Illinois

NWS Quad Cities, IA issued this tornado warning at Sep 25, 2018, 3:48 PM CDT for Whiteside County, Illinois. It was in force for 6 min. 1 report 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: Sep 25, 2018, 3:48 PM CDT (20:48 UTC)
Expired: Sep 25, 2018, 3:54 PM CDT
In force: 6 min
Issued by: NWS Quad Cities, IA
Area: Storm-based polygon
Tornado: Radar indicated
Hail: 0.75 in

County Whiteside County, IL

The radar

The Quad Cities radar (KDVN), 74 km from the middle of the area, began a volume at 20:48 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
Sep 25, 3:49 PM CDT	TSTM WND DMG	1 Ese Deer Grove, IL	TWO LARGE TREE BRANCHES DOWN.

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
Sep 25, 1:36 PM CDT	Severe Thunderstorm Watch	SPC	8 hr

The nearest sounding before it

Davenport, (KDVN), launched 12:00Z, 8.8 hours before the alert went out and 68 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: 47 J/kg
Mixed-layer CIN: -108 J/kg
Mixed-layer LCL: 703 m above ground
0-6 km bulk shear: 41 kt
0-1 km storm-relative helicity: 4 m²/s²
0-3 km storm-relative helicity: 38 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

106 
WFUS53 KDVN 252048
TORDVN
ILC195-252115-
/O.NEW.KDVN.TO.W.0037.180925T2048Z-180925T2115Z/

BULLETIN - EAS ACTIVATION REQUESTED
Tornado Warning
National Weather Service Quad Cities IA/IL
348 PM CDT TUE SEP 25 2018

The National Weather Service in the Quad Cities has issued a

* Tornado Warning for...
  Southeastern Whiteside County in northwestern Illinois...

* Until 415 PM CDT.
    
* At 347 PM CDT, a severe thunderstorm capable of producing a tornado
  was located over Deer Grove, or 11 miles south of Rock Falls,
  moving east at 60 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 tornadic thunderstorm will remain over mainly rural areas of
  southeastern Whiteside County.

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 4159 8963 4158 8967 4158 8977 4167 8979
      4171 8963
TIME...MOT...LOC 2047Z 269DEG 51KT 4160 8967 

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

$$

Gibbs

2 follow-up statements

360 
WWUS53 KDVN 252052 RRA
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
352 PM CDT TUE SEP 25 2018

ILC195-252115-
/O.CON.KDVN.TO.W.0037.000000T0000Z-180925T2115Z/
Whiteside IL-
352 PM CDT TUE SEP 25 2018

...A TORNADO WARNING REMAINS IN EFFECT UNTIL 415 PM CDT FOR
SOUTHEASTERN WHITESIDE COUNTY...
    
At 352 PM CDT, a severe thunderstorm capable of producing a tornado
was located near Walnut, or 11 miles southwest of Walton, moving east
at 60 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.

Locations impacted include...
Deer Grove.

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 4159 8963 4158 8967 4159 8973 4165 8974
      4166 8963
TIME...MOT...LOC 2052Z 267DEG 50KT 4161 8960 

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

$$

Gibbs

039 
WWUS53 KDVN 252054
SVSDVN

Severe Weather Statement
National Weather Service Quad Cities IA/IL
354 PM CDT TUE SEP 25 2018

ILC195-252103-
/O.CAN.KDVN.TO.W.0037.000000T0000Z-180925T2115Z/
Whiteside IL-
354 PM CDT TUE SEP 25 2018

...THE TORNADO WARNING FOR SOUTHEASTERN WHITESIDE COUNTY IS
CANCELLED...
        
The storm which prompted the warning has moved out of the area.
Therefore, the warning has been cancelled.  However gusty winds and
heavy rain are still possible with this thunderstorm.

A Severe Thunderstorm Watch remains in effect until 1000 PM CDT for
north central and northwestern Illinois.

Remember, a Severe Thunderstorm Warning still remains in effect for
Whiteside County until 415 PM CDT.

LAT...LON 4159 8963 4158 8967 4159 8973 4165 8974
      4166 8963
TIME...MOT...LOC 2052Z 269DEG 51KT 4161 8958 

$$

Gibbs

The office that day

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

Issued	Product	Office	Counties	Lasted
Sep 25, 2:27 PM CDT	Severe Thunderstorm Warning	DVN	Rock Island, Whiteside	63 min
Sep 25, 2:45 PM CDT	Tornado Warning	DVN	Henderson, Mercer, Warren	45 min
Sep 25, 3:14 PM CDT	Severe Thunderstorm Warning	DVN	Bureau, Carroll, Henry, Rock Island, Whiteside	61 min
Sep 25, 4:01 PM CDT	Severe Thunderstorm Warning	DVN	Bureau	29 min
Sep 25, 4:13 PM CDT	Severe Thunderstorm Warning	DVN	Bureau, Putnam	47 min

Nearby

Tornado Warnings in Illinois, 2018 Every tornado warning in 2018 Tornadoes 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.