Alert archive / Wisconsin / Tornado Warnings in 2009
Tornado Warning 31, NWS Twin Cities, MN
NWS Twin Cities, MN issued this tornado warning at Aug 8, 2009, 9:43 PM CDT for Polk County, Saint Croix County, Wisconsin; Washington County, Minnesota. It was in force for 32 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
- Aug 8, 2009, 9:43 PM CDT (02:43 UTC)
- Expired
- Aug 8, 2009, 10:15 PM CDT
- In force
- 32 min
- Issued by
- NWS Twin Cities, MN
- Area
- Storm-based polygon
Counties Washington County, MN, Polk County, WI, Saint Croix County, WI
The radar
The Minneapolis radar (KMPX), 72 km from the middle of the area, began a volume at 02:44 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 |
|---|---|---|---|
| Aug 8, 9:45 PM CDT | TSTM WND DMG | 1 Sse Hugo, MN | TREE DOWN ACROSS ROAD. |
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 |
|---|---|---|---|
| Aug 8, 3:46 PM CDT | Tornado Watch | SPC | 8 hr |
The nearest sounding before it
Minneapolis, MN (KMPX), launched 00:00Z, 2.7 hours before the alert went out and 74 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.
- Mixed-layer CAPE
- 3715 J/kg
- Mixed-layer CIN
- -17 J/kg
- Mixed-layer LCL
- 841 m above ground
- 0-6 km bulk shear
- 47 kt
- 0-1 km storm-relative helicity
- 190 m²/s²
- 0-3 km storm-relative helicity
- 163 m²/s²
- Significant tornado parameter
- 3.8
- Supercell composite
- 16.8
The text
As transmitted, in the capitals the NWS used until 2016.
000 WFUS53 KMPX 090243 TORMPX MNC163-WIC095-109-090315- /O.NEW.KMPX.TO.W.0031.090809T0243Z-090809T0315Z/ BULLETIN - EAS ACTIVATION REQUESTED TORNADO WARNING NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 943 PM CDT SAT AUG 8 2009 THE NATIONAL WEATHER SERVICE IN THE TWIN CITIES HAS ISSUED A * TORNADO WARNING FOR... NORTHERN WASHINGTON COUNTY IN EAST CENTRAL MINNESOTA... EXTREME SOUTHWESTERN POLK COUNTY IN NORTHWEST WISCONSIN... NORTHWESTERN ST. CROIX COUNTY IN WEST CENTRAL WISCONSIN... * UNTIL 1015 PM CDT * AT 941 PM CDT...RADAR WAS TRACKING A SEVERE STORM WITH STRONG ROTATION. THE MOST DANGEROUS PART OF THE STORM WAS 3 MILES SOUTH OF HUGO...AND MOVING EAST AT 30 MPH. * LOCATIONS IN THE WARNING INCLUDE... DELLWOOD... AREAS NORTH OF STILLWATER... MARINE ON ST CROIX... SOMERSET... BOARDMAN... AREAS SOUTH OF EAST FARMINGTON... PRECAUTIONARY/PREPAREDNESS ACTIONS... WHEN A TORNADO WARNING IS ISSUED BASED ON RADAR...IT MEANS THAT STRONG ROTATION HAS BEEN DETECTED IN THE STORM. A TORNADO MAY ALREADY BE ON THE GROUND...OR IS EXPECTED TO DEVELOP SHORTLY. && LAT...LON 4523 9262 4506 9257 4503 9298 4519 9298 TIME...MOT...LOC 0242Z 257DEG 24KT 4512 9295 $$
1 follow-up statement
000 WWUS53 KMPX 090257 SVSMPX SEVERE WEATHER STATEMENT NATIONAL WEATHER SERVICE TWIN CITIES/CHANHASSEN MN 957 PM CDT SAT AUG 8 2009 MNC163-WIC095-109-090315- /O.CON.KMPX.TO.W.0031.000000T0000Z-090809T0315Z/ WASHINGTON MN-POLK WI-ST. CROIX WI- 957 PM CDT SAT AUG 8 2009 ...A TORNADO WARNING REMAINS IN EFFECT UNTIL 1015 PM CDT FOR NORTHWESTERN ST. CROIX...EXTREME SOUTHWESTERN POLK AND NORTHERN WASHINGTON COUNTIES... AT 955 PM CDT...RADAR INDICATED A SEVERE THUNDERSTORM WITH STRONG ROTATION...4 MILES SOUTHEAST OF DOWNTOWN HUGO...AND MOVING EAST AT 25 MPH. LOCATIONS IN THE WARNING INCLUDE... MARINE ON ST CROIX...SOMERSET...BOARDMAN...AREAS NORTH OF STILLWATER... AND AREAS SOUTH OF EAST FARMINGTON. PRECAUTIONARY/PREPAREDNESS ACTIONS... THIS STORM HAS A HISTORY OR PRODUCING TORNADOES AND LARGE DAMAGING HAIL. && LAT...LON 4523 9262 4506 9257 4507 9297 4519 9298 TIME...MOT...LOC 0256Z 259DEG 23KT 4513 9289 $$
The office that day
Everything else NWS Twin Cities, MN issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Aug 8, 10:01 PM CDT | Tornado Warning | MPX | Saint Croix | 29 min |
| Aug 8, 10:14 PM CDT | Tornado Warning | MPX | Polk, Saint Croix | 31 min |
| Aug 8, 10:29 PM CDT | Tornado Warning | MPX | Saint Croix | 46 min |
| Aug 8, 11:14 PM CDT | Tornado Warning | MPX | Dunn, Saint Croix | 46 min |
| Aug 9, 12:00 AM CDT | Tornado Warning | MPX | Dunn | 30 min |
| Aug 9, 12:36 AM CDT | Special Weather Statement | MPX | Chippewa, Eau Claire | 54 min |
| Aug 9, 1:27 AM CDT | Special Weather Statement | MPX | Chippewa | 33 min |
| Aug 8, 8:31 PM CDT | Tornado Warning | MPX | Hennepin | 29 min |
| Aug 8, 8:49 PM CDT | Tornado Warning | MPX | Anoka, Hennepin, Ramsey | 26 min |
| Aug 8, 9:13 PM CDT | Tornado Warning | MPX | Anoka, Ramsey, Washington | 32 min |
Nearby
Tornado Warnings in Wisconsin, 2009Tornado Warnings in Minnesota, 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.