Severe Thunderstorm Warning 70, NWS La Crosse, WI

130 
WWUS53 KARX 090115
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
815 PM CDT Sat Aug 8 2020

WIC053-063-081-090145-
/O.CON.KARX.SV.W.0070.000000T0000Z-200809T0145Z/
La Crosse WI-Jackson WI-Monroe WI-
815 PM CDT Sat Aug 8 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR NORTHEASTERN LA CROSSE...SOUTHERN JACKSON AND NORTHERN MONROE
COUNTIES...

At 812 PM CDT, a severe thunderstorm was located 10 miles east of
Millston, or 13 miles north of Tomah, moving east at 50 mph.

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

SOURCE...Law enforcement.

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

This severe thunderstorm will remain over mainly rural areas of
northeastern La Crosse, southern Jackson and northern Monroe
Counties, including the following locations... Warrens, City Point,
Melrose, Shamrock, Pigeon Creek Campground, Potters Flowage and The
North Flowage.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4402 9095 4419 9106 4442 9032 4403 9031
TIME...MOT...LOC 0112Z 260DEG 44KT 4417 9044 

HAIL...0.88IN
WIND...60MPH
 
$$

Peters

474 
WWUS53 KARX 090125
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
825 PM CDT Sat Aug 8 2020

WIC063-090134-
/O.CAN.KARX.SV.W.0070.000000T0000Z-200809T0145Z/
La Crosse WI-
825 PM CDT Sat Aug 8 2020

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN LA CROSSE COUNTY
IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

LAT...LON 4402 9074 4424 9088 4442 9032 4403 9031
TIME...MOT...LOC 0124Z 253DEG 29KT 4420 9030 

$$

WIC053-081-090145-
/O.CON.KARX.SV.W.0070.000000T0000Z-200809T0145Z/
Jackson WI-Monroe WI-
825 PM CDT Sat Aug 8 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 845 PM CDT
FOR SOUTHEASTERN JACKSON AND NORTHEASTERN MONROE COUNTIES...

At 824 PM CDT, a severe thunderstorm was located 10 miles southwest
of Babcock, or 17 miles northeast of Tomah, moving east at 35 mph.

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

SOURCE...Law enforcement.

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

Locations impacted include...
Millston, Warrens, City Point, Wyeville, Shamrock, Pigeon Creek
Campground, County Roads I And I I, Potters Flowage, The North
Flowage, Normay Ridge, I 94 Exit 135, Valley Junction, Jellystone
Park Near Warrens, I 94 Exit 128, Bear Bluff Township, Shennington,
The Rezin Landing Strip, Fall Hall Glen, Kirby and Seventeen Flowage.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4402 9074 4424 9088 4442 9032 4403 9031
TIME...MOT...LOC 0124Z 253DEG 29KT 4420 9030 

HAIL...0.88IN
WIND...60MPH
 
$$

Peters

Area Forecast Discussion...UPDATED
National Weather Service La Crosse WI
647 PM CDT Sat Aug 8 2020

.SHORT TERM...(This evening through Sunday)
Issued at 325 PM CDT Sat Aug 8 2020

Forecast concerns through Sunday will be lingering storms toward
Juneau and Adams counties this afternoon and how the thunderstorms
in west central MN move east...then evolution of storms over the
Central Plains later today and tonight and into our area late
Sunday morning and afternoon along with the severe weather
potential.

The 500mb trough over the Upper Peninsula of Michigan indeed
produced a convective complex across northern Minnesota that
dropped southeast into Wisconsin through 12Z. The bulk of the
activity was northeast of the forecast area, however the Medford
AWOS did pick up 0.46". Some trailing shortwave energy combined
with convergence along a boundary that was over southern MN toward
Jackson Co. WI produced some agitated cumulus a little before
9am. Over time...scattered thunderstorms formed in west to east
fashion where moisture was pooled. Coverage was limited to the
southwest where the forcing was weaker and the cap stronger.
Storms were mostly sub- severe with small hail and lightning,
however we did have isolated storms that produced nickel-sized
hail near Warrens in Monroe county.

The latest water vapor satellite imagery shows the cluster of storms
in southwest and north central Minnesota with some new development
closer to the surface front in eastern South Dakota.

The CAMs and operational models had a tough time with the convection
this morning with a wide variety of solutions. Looking at the CAMs
for the rest of this afternoon into this evening...they are mostly
dry with a few peppering cells across the northern central part of
the forecast area and others developing storms across parts of our
northeast Iowa and Wisconsin Co. with the subtle shortwave moving
east.  The cluster has been persistent since about 15Z near
Carpenter SD and is traveling east at around 32kts. The subjective
surface map and visible satellite showed a couple of potential
boundaries and a possible gravity wave across southern Minnesota
earlier today. Farther south into northeast Iowa and southwest
Wisconsin, there may be another boundary. The shortwave is moving
into a very unstable environment and steep lapse rates of 8.5 to
9 deg C. in place. 700mb moisture appears pool through around 22Z
toward our forecast area then is forecast to decrease farther
east. Not confident the models have this correct and will continue
with chance pops with the shortwave between now and 01Z. Unsure
if additional storms can develop after 01Z but will maintain
isolated mention in the vicinity of the wave. SPC has the higher
risk for severe storms just west of our area, however should
storms maintain themselves, they could produce damaging winds and
large hail. The precipitable water environment is high as
well...thus any storms will be capable of putting down locally
heavy rains. The area is in need of rainfall and the wave
progressive. The marginal areas for excessive rainfall today and
Sunday just clip our northern counties north of I90.

A shortwave trough in Western High Plains will move into Minnesota
overnight gradually pushing into the forecast area later Sunday
morning into Sunday afternoon. The stronger frontogenesis remains
west of our area tonight and north of our area during the day
Sunday. Do increase pops late Sunday morning into Sunday afternoon
with the pre-frontal trough. Forecast soundings show a continued
moderate to high instability around 4000J/kg with very steep lapse
rates. Hodographs do have some sfc -3km SRH of 150-200m2/s2, thus
all hazards would be possible. The slight risk from SPC was
expanded to cover the entire forecast area.

.LONG TERM...(Sunday night through Saturday)
Issued at 325 PM CDT Sat Aug 8 2020

Showers and storms look to linger into Sunday evening-night, with
a few strong to severe possible. A cold front will slide through
the local area late Sunday night, with surface high pressure
building in it's wake. The front will act to bring more
comfortable weather to the area to start the new work week as
lower dewpoints filter in. Some remnant showers may persist on
Monday mainly across areas to the south as the front exits east.
Pretty quiet with seasonable temperatures through Tuesday, but
occasional chances for showers and storms return midweek onward as
a few shortwave troughs move through the area.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 636 PM CDT Sat Aug 8 2020

Unsettled weather will persist through the TAF period. High
humidity and hot temperatures will result in an unstable air mass
and periods of storms through the next 24 hours. The strongest
storms and most organized convection are expected Sunday, mainly
in the afternoon and evening as a front nears the area. Outside of
storms, MVFR ceilings and visibility are expected much of tonight,
improving to VFR (again, outside of storms) by midday Sunday.

&&

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

SHORT TERM...Zapotocny
LONG TERM...NB
AVIATION...DMD

Hazardous Weather Outlook
National Weather Service La Crosse WI
1201 PM CDT Sat Aug 8 2020

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-091715-
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-
1201 PM CDT Sat Aug 8 2020

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

.DAY ONE...Today and Tonight

Scattered storms are possible. Stronger storms could produce
gusty winds, hail and locally heavy rain.

.DAYS TWO THROUGH SEVEN...Sunday through Friday

Scattered storms are expected Sunday. Some could become severe
during the afternoon and evening, with a higher risk currently
lying north of Interstate 90. Threats include damaging winds,
hail
and locally heavy rain.

Sunday will also be warm and humid with heat indices in the 90s.

There are additional storm chances for Wednesday into Friday. It
is too early to determine if there would be a severe threat.

.SPOTTER INFORMATION STATEMENT...

A few spotter groups may be needed Sunday.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

Zapotocny

nofwd