Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2020

Severe Thunderstorm Warning 41, NWS Twin Cities, MN

July 9, 2020Polk County, Saint Croix County, Wisconsin

NWS Twin Cities, MN issued this severe thunderstorm warning at Jul 9, 2020, 6:04 AM CDT for Polk County, Saint Croix County, Wisconsin. It was in force for 14 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: Jul 9, 2020, 6:04 AM CDT (11:04 UTC)
Expired: Jul 9, 2020, 6:18 AM CDT
In force: 14 min
Issued by: NWS Twin Cities, MN
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

Counties Polk County, WI, Saint Croix County, WI

The radar

The Minneapolis radar (KMPX), 98 km from the middle of the area, began a volume at 11:03 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
Jul 9, 6:10 AM CDT	HAIL 0.7	4 S New Richmond, WI	PICTURE VIA TWITTER.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 11.1 hours before the alert went out and 100 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: 2332 J/kg
Mixed-layer CIN: -31 J/kg
Mixed-layer LCL: 1764 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 34 m²/s²
0-3 km storm-relative helicity: 131 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

As transmitted.

955 
WUUS53 KMPX 091104
SVRMPX
WIC095-109-091130-
/O.NEW.KMPX.SV.W.0041.200709T1104Z-200709T1130Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Twin Cities/Chanhassen MN
604 AM CDT Thu Jul 9 2020

The National Weather Service in The Twin Cities has issued a

* Severe Thunderstorm Warning for...
  North central St. Croix County in west central Wisconsin...
  Southeastern Polk County in northwestern Wisconsin...

* Until 630 AM CDT.

* At 604 AM CDT, a severe thunderstorm was located near New Richmond,
  or 16 miles north of River Falls, moving northeast at 40 mph.

  HAZARD...60 mph wind gusts and quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Hail damage to vehicles is expected. Expect wind damage 
           to roofs, siding, and trees.

* Locations impacted include...
  New Richmond, Amery, Clear Lake, Cylon, Deer Park, Deronda and
  Houlton.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 4501 9251 4505 9257 4532 9244 4522 9216
      4521 9216
TIME...MOT...LOC 1104Z 216DEG 35KT 4509 9249 

HAIL...1.00IN
WIND...60MPH
 
$$

TDH

1 follow-up statement

996 
WWUS53 KMPX 091118
SVSMPX

Severe Weather Statement
National Weather Service Twin Cities/Chanhassen MN
618 AM CDT Thu Jul 9 2020

WIC095-109-091125-
/O.CAN.KMPX.SV.W.0041.000000T0000Z-200709T1130Z/
St. Croix WI-Polk WI-
618 AM CDT Thu Jul 9 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTH CENTRAL ST. CROIX AND
SOUTHEASTERN POLK COUNTIES IS CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However small hail and
heavy rain are still possible with this thunderstorm.

LAT...LON 4501 9251 4505 9257 4532 9244 4522 9216
      4521 9216
TIME...MOT...LOC 1115Z 216DEG 35KT 4518 9239 

$$

TDH

The office that day

Everything else NWS Twin Cities, MN issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jul 8, 11:54 PM CDT	Special Weather Statement	MPX	Rusk	51 min
Jul 9, 5:14 AM CDT	Special Weather Statement	MPX	Chippewa	31 min
Jul 9, 5:15 AM CDT	Special Weather Statement	MPX	Eau Claire	30 min
Jul 9, 5:30 AM CDT	Special Weather Statement	MPX	Polk	45 min
Jul 9, 5:38 AM CDT	Severe Thunderstorm Warning	MPX	Pierce, Saint Croix	24 min
Jul 9, 5:48 AM CDT	Special Weather Statement	MPX	Chippewa, Eau Claire	42 min
Jul 9, 5:51 AM CDT	Severe Thunderstorm Warning	MPX	Saint Croix	13 min
Jul 9, 6:19 AM CDT	Special Weather Statement	MPX	Saint Croix	41 min
Jul 9, 7:10 AM CDT	Special Weather Statement	MPX	Dunn	35 min
Jul 9, 7:20 AM CDT	Special Weather Statement	MPX	Eau Claire	25 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2020 Every severe thunderstorm warning 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.