Alert archive / Wisconsin / Severe Thunderstorm Warnings in 2019

Severe Thunderstorm Warning 121, NWS La Crosse, WI

September 24, 2019Trempealeau County, Wisconsin

NWS La Crosse, WI issued this severe thunderstorm warning at Sep 24, 2019, 8:54 PM CDT for Trempealeau County, Wisconsin. It was in force for 21 min. 2 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: Sep 24, 2019, 8:54 PM CDT (01:54 UTC)
Expired: Sep 24, 2019, 9:15 PM CDT
In force: 21 min
Issued by: NWS La Crosse, WI
Area: Storm-based polygon
Hail: 0.75 in
Wind: 60.0 mph

County Trempealeau County, WI

The radar

The La Crosse radar (KARX), 34 km from the middle of the area, began a volume at 01:55 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 24, 9:10 PM CDT	TSTM WND DMG	Dodge, WI	TREES AND POWERLINES BLOWN DOWN.
Sep 24, 9:11 PM CDT	TSTM WND DMG	Galesville, WI	TREES AND POWERLINES BLOWN DOWN.

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

Did it verify

Verified. The Iowa Environmental Mesonet's Cow matched 2 storm reports to this severe thunderstorm warning; the first came 16 minutes after it went out.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

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 24, 4:43 PM CDT	Tornado Watch	SPC	7 hr

The nearest sounding before it

Minneapolis, MN (KMPX), launched 00:00Z, 1.9 hours before the alert went out and 195 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: 1764 J/kg
Mixed-layer CIN: -32 J/kg
Mixed-layer LCL: 1238 m above ground
0-6 km bulk shear: 55 kt
0-1 km storm-relative helicity: 113 m²/s²
0-3 km storm-relative helicity: 158 m²/s²
Significant tornado parameter: 1.5
Supercell composite: 10.5

Open this sounding in Storm Lab

The text

As transmitted.

880 
WUUS53 KARX 250154
SVRARX
WIC121-250230-
/O.NEW.KARX.SV.W.0121.190925T0154Z-190925T0230Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service La Crosse WI
854 PM CDT Tue Sep 24 2019

The National Weather Service in La Crosse has issued a

* Severe Thunderstorm Warning for...
  Southern Trempealeau County in west central Wisconsin...

* Until 930 PM CDT.

* At 853 PM CDT, severe thunderstorms were located along a line
  extending from near Arcadia to near Dakota, moving northeast at 35 
  mph. Wind gusts have knocked power out in the Winona Minnesota 
  area as they moved through. Fountain City also reported 60 mph 
  winds.

  HAZARD...60 mph wind gusts.

  SOURCE...Trained weather spotters.

  IMPACT...Expect damage to roofs, siding, and trees.

* Severe thunderstorms will be near...
  Arcadia around 900 PM CDT.

Other locations impacted by these severe thunderstorms include
Highway 95 And County D, Peacock Hill, Tamarack, Camp Decorah, Beach
Corners, Perrot State Park and Frenchville.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4423 9155 4429 9117 4408 9115 4409 9117
      4409 9120 4405 9122 4407 9127 4406 9128
      4407 9131 4403 9134 4401 9134 4398 9142
      4400 9144 4403 9154 4407 9155 4410 9154
      4415 9157 4422 9158
TIME...MOT...LOC 0153Z 229DEG 31KT 4422 9159 4387 9137 

HAIL...<.75IN
WIND...60MPH
 
$$

Shea

1 follow-up statement

493 
WWUS53 KARX 250215
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
915 PM CDT Tue Sep 24 2019

WIC121-250225-
/O.CAN.KARX.SV.W.0121.000000T0000Z-190925T0230Z/
Trempealeau WI-
915 PM CDT Tue Sep 24 2019

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHERN TREMPEALEAU COUNTY IS
CANCELLED...
    
The storms which prompted the warning have weakened below severe
limits, and have exited the warned area. Therefore, the warning has 
been cancelled. There are no longer any severe thunderstorm warnings 
for Trempealeau County Wisconsin.

A Tornado Watch remains in effect until midnight CDT.

LAT...LON 4423 9155 4429 9117 4408 9115 4409 9117
      4409 9120 4405 9122 4407 9127 4406 9128
      4407 9131 4403 9134 4401 9134 4398 9142
      4400 9144 4403 9154 4407 9155 4410 9154
      4415 9157 4422 9158
TIME...MOT...LOC 0213Z 229DEG 31KT 4433 9141 4398 9119 

$$

Shea

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS La Crosse, WI wrote its last area forecast discussion before this severe thunderstorm warning went out at Sep 24, 6:08 PM CDT, 2 hours 46 minutes earlier.

Area forecast discussion, Sep 24, 6:08 PM CDT, 2 hours 46 minutes before

Area Forecast Discussion
National Weather Service La Crosse WI
608 PM CDT Tue Sep 24 2019

.SHORT TERM...(Tonight through Wednesday Night)
Issued at 140 PM CDT Tue Sep 24 2019

Current water vapor showing a strong mid-level trough moving through
the Dakotas/northwest MN. This was pushing a cold front across MN
with radar showing some showers and few storms firing along it.

This front will continue to push southeast into the area by this
evening with a corridor of 1500-3000J/kg of MUCAPE and 0-3km bulk
shear around 30kt in place. Expecting storms to fire by 6 pm
(lasting through 10 pm) as the front pushes in and as cap weakens.
Question is still there as to whether the bulk of these storms will
be surface based as the caps weakens -or- will the cap be strong
enough for mainly elevated storms. This will dictate whether there
will be a tornado threat (if they are indeed surface based) -or-
mainly elevated hail/wind producers. Will keep an eye on all severe
parameters with this situation.

Breezy west winds and cooler conditions expected for Wednesday in
the wake of the low and cold front. With lingering cooler cyclonic
flow aloft, could see a few pop-up showers across northern WI. Look
for highs in the mid 60s to lower 70s.

High pressure builds in Wednesday night for clear and cool
conditions. Plan on overnight lows mainly in the 40s -coldest in the
sand country of central WI.

.LONG TERM...(Thursday through Tuesday)
Issued at 140 PM CDT Tue Sep 24 2019

High pressure will hold across the region through Thursday but then
fairly fast west-northwest flow aloft ushers in low pressure across
the Dakotas into MN Thursday night with push of warm air advection
and moisture transport into our area. This should fuel a few showers
and storms. Shower and storm chances continue into Friday as the
cold front pushes through the area. Otherwise, look for highs once
again in the 60s/lower 70s.

Shower and storm chances will be seen this weekend into next week as
upper flow becomes more southwesterly with embedded waves of low
pressure.

&&

.AVIATION...(For the 00Z TAFS through 00Z Wednesday evening)
Issued at 608 PM CDT Tue Sep 24 2019

Closely watching showers and storms that have developed just west
of the local area as expected. Based on current timing, those will
advance east and impact RST roughly 01-03Z and LSE 02-04Z, though
with some minor adjustments to timing still likely as storms near.
Brief IFR conditions expected in heavier rainfall, and can't rule
out some hail or brief wind gusts to 40+ knots in any storms, but
with a rapid clearing trend expected once storms pass. Heading
into Wednesday, some passing cumulus clouds are likely as cooler
air aloft works through the region, with winds shifting
west/northwesterly and gusting 20-25 knots at times.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&

SHORT TERM...DAS
LONG TERM...DAS
AVIATION...Lawrence

Hazardous weather outlook, Sep 24, 2:19 PM CDT, 6 hours 35 minutes before

Hazardous Weather Outlook
National Weather Service La Crosse WI
219 PM CDT Tue Sep 24 2019

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-251930-
Mitchell-Howard-Winneshiek-Allamakee-Floyd-Chickasaw-Fayette-
Clayton-Wabasha-Dodge-Olmsted-Winona-Mower-Fillmore-Houston-
Taylor-Clark-Buffalo-Trempealeau-Jackson-La Crosse-Monroe-Juneau-
Adams-Vernon-Crawford-Richland-Grant-
219 PM CDT Tue Sep 24 2019

This Hazardous Weather Outlook is for portions of southeast
Minnesota...northeast Iowa and southwest into central Wisconsin.

.DAY ONE...Through Tonight

Severe storms will be possible across the area between 6 PM and
midnight tonight. The main threat with these storms will be large
hail, but damaging winds and isolated tornadoes will also be
possible.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

There will be on and off thunderstorm chances Thursday night
through Monday, with periodic heavy rain possible on Friday and
from Sunday night into the middle of next week.

.SPOTTER INFORMATION STATEMENT...

Spotters may be needed this evening.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

In the hours before

Local storm report, Sep 24, 8:01 PM CDT, 53 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
801 PM CDT TUE SEP 24 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0757 PM     TSTM WND GST     3 E AUSTIN              43.67N 92.92W
09/24/2019  M60 MPH          MOWER              MN   AWOS

            AWOS STATION KAUM AUSTIN MUNICIPAL AIRPORT.

&&

CA

Local storm report, Sep 24, 8:16 PM CDT, 38 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
816 PM CDT TUE SEP 24 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0810 PM     TSTM WND GST     3 NNW STEWARTVILLE      43.90N 92.50W
09/24/2019  M60 MPH          OLMSTED            MN   ASOS

            ASOS STATION KRST ROCHESTER INTERNATIONAL
            AIRPORT.

&&

CA

Local storm report, Sep 24, 8:22 PM CDT, 32 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
822 PM CDT TUE SEP 24 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0813 PM     TSTM WND GST     3 NE ROCHESTER          44.04N 92.42W
09/24/2019  M41 MPH          OLMSTED            MN   BROADCAST MEDIA

&&

CA

Local storm report, Sep 24, 8:23 PM CDT, 31 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
823 PM CDT TUE SEP 24 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0807 PM     TSTM WND GST     1 ENE DEXTER            43.73N 92.68W
09/24/2019  M65 MPH          MOWER              MN   MESONET

            MESONET STATION MN010 1 ENE DEXTER.

&&

CA

Local storm report, Sep 24, 8:40 PM CDT, 14 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
840 PM CDT TUE SEP 24 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0837 PM     TSTM WND GST     1 S SAINT CHARLES       43.95N 92.07W
09/24/2019  E50 MPH          WINONA             MN   TRAINED SPOTTER

            ESTIMATED 50 MPH WINDS NEAR THE INTERSECTION
            OF I-90 AND HWY 74.

&&

JSB

Local storm report, Sep 24, 8:43 PM CDT, 11 minutes before

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
843 PM CDT TUE SEP 24 2019

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0820 PM     TSTM WND DMG     5 WNW VIOLA             44.09N 92.37W
09/24/2019                   OLMSTED            MN   PUBLIC

            3 INCH DIAMETER TREE LIMB DOWN. PHOTO VIA
            SOCIAL MEDIA.

&&

CA

The office that day

Everything else NWS La Crosse, WI issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Sep 24, 7:39 PM CDT	Special Weather Statement	ARX	Clark, Taylor	36 min
Sep 24, 8:11 PM CDT	Severe Thunderstorm Warning	ARX	Buffalo	39 min
Sep 24, 8:23 PM CDT	Severe Thunderstorm Warning	ARX	Buffalo	44 min
Sep 24, 8:42 PM CDT	Severe Thunderstorm Warning	ARX	Trempealeau	33 min
Sep 24, 8:47 PM CDT	Severe Thunderstorm Warning	ARX	Clark, Taylor	30 min
Sep 24, 9:06 PM CDT	Severe Thunderstorm Warning	ARX	Clark, Jackson	54 min
Sep 24, 10:04 PM CDT	Special Weather Statement	ARX	La Crosse, Monroe	56 min
Sep 24, 10:47 PM CDT	Special Weather Statement	ARX	Juneau, Monroe	43 min

Nearby

Severe Thunderstorm Warnings in Wisconsin, 2019 Every severe thunderstorm warning in 2019

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.