Special Weather Statement, NWS La Crosse, WI

Area Forecast Discussion
National Weather Service La Crosse WI
153 PM CDT Tue Jun 29 2021

.SHORT TERM...(This evening through Wednesday)
Issued at 152 PM CDT Tue Jun 29 2021

Hard to believe we were battling drought when short term concerns
are again threat for localized flooding. Combination of steady
moisture advection from the south and passing short wave trough to
the north leading to one area of progressive convection north of
Interstate 90 and another area of more focused, less progressive
convection across parts of northeast Iowa into Wisconsin not far
from the Wisconsin River valley. The latter of which has shown signs
of continuous new development and training over same area, near to
the heaviest rain from this weekend. This is parallel to mid level
wind speed max south of upper low. Surface dewpoints in the lower to
mid 70s also providing fuel for efficient rainfall producers through
warm layer. Add in the hilly terrain and we have more localized
flooding issues to deal with. As short wave continues to push east,
convergent focus should also begin to shift ending this threat.

Meanwhile to the north MUCAPE values of 1000-1500 J/Kg sufficient
enough for small bowing segments even with less than ideal mid layer
lapse rates, but lower level shear /below 3km/ remains weak and
hence storms expected to remain fairly unorganized. Still could see
some gusty winds and brief heavy rains as this threat gradually
rotates east of the area heading into the evening. Like storms to
the south, will have to watch for storms that align east-west and do
any type of redevelopment for water concerns.

On Wednesday northwest flow aloft becomes more dominant but some
question on how far south boundary will get. Models appear to be
trending further south with this and hence have followed suit by
adjusting rain threat further south as well.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 152 PM CDT Tue Jun 29 2021

Warmer and drier conditions heading into the holiday weekend will be
the main theme of the extended forecast. Anomalous ridge over
western North America finally begins to break down and slowly
migrates into central Canada on Thursday. Meanwhile an upper low and
associated longwave trough will drop south from James Bay into the
Great Lakes region. This may trigger isolated showers and perhaps a
few storms on Thursday as the trough's vorticity maximum grazes the
Mississippi River, but overall rain chances are low.

Model consensus for Friday onward has improved since this time
yesterday, with most solutions now favoring the aforementioned
low/trough displaced further east by the encroaching upstream ridge.
Still some differences between deterministic/ensemble guidance as to
whether the trough develops a closed low over the eastern Great
Lakes, but for now looks like very little, if any, local influence.
While the overall ridge structure continues to break down as it
encroaches on the Mississippi Valley, it will bring strong height
rises locally that will help suppress rain chances through the
Fourth of July weekend. Friday will be a tad cooler with highs in
the 70s to around 80 with the trough overhead. But with ridging
building in thereafter, temperatures become toastier from Saturday
through Monday with highs again returning to around 90 for many.

Next chance of rain returns Monday into Tuesday as the ridge breaks
down and we get into a west/northwest flow pattern aloft with
embedded shortwaves. Adding to shower/storm potential early next
week will be an elongated front dropping southward into the
region.

&&

.AVIATION...(For the 18Z TAFS through 18Z Wednesday afternoon)
Issued at 1235 PM CDT Tue Jun 29 2021

Area has a mix of MVFR and VFR ceilings at moment as short wave wave
rotates out of central Minnesota into the northern half of
Wisconsin. Also watching development of convection closely but
stronger storms expected to stay north and south of the Interstate
90 corridor at least for short term. Widely scattered nature of
storms through the afternoon should have brief impacts if they pass
near airfields.

As this wave exits the area should see diurnal driven cloud field
fade this evening leading to VFR conditions into Wednesday. Will
need to watch for localized fog development but not confident enough
to include in TAF sites at this time. More diurnal cumulus expected
Wednesday as well.

&&

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

SHORT TERM...Shea
LONG TERM...Kurz
AVIATION...Shea

Hazardous Weather Outlook
National Weather Service La Crosse WI
321 AM CDT Tue Jun 29 2021

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-301200-
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-
321 AM CDT Tue Jun 29 2021

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

.DAY ONE...Today and Tonight

Scattered thunderstorms are possible today. Although organized
severe weather is not expected, strong winds, small hail, and
locally heavy rainfall may accompany any storms, especially this
afternoon and early evening.

.DAYS TWO THROUGH SEVEN...Wednesday through Monday

Isolated storms remain possible Wednesday into Thursday but severe
weather is unlikely.

.SPOTTER INFORMATION STATEMENT...

No action needed.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

Special Weather Statement
National Weather Service La Crosse WI
354 PM CDT Tue Jun 29 2021

MNZ088-WIZ032-033-292130-
Winona-Buffalo-Trempealeau-
354 PM CDT Tue Jun 29 2021

...A STRONG THUNDERSTORM WILL AFFECT CENTRAL WINONA...SOUTHEASTERN
BUFFALO AND SOUTHWESTERN TREMPEALEAU COUNTIES...

At 354 PM CDT, a strong thunderstorm was located over Fountain City,
or near Winona, moving southeast at 35 mph.

Winds in excess of 30 mph and pea size hail are possible with this
storm.

Locations impacted include...
Winona, Goodview, Fountain City, Dodge, Minnesota City, Czechville,
Merrick State Park, Highway 95 And County G, Lock And Dam 5 A,
Marshland, Whitman, Pickwick, Lock And Dam 5 and Bluff Siding.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 4417 9183 4426 9169 4412 9135 4395 9161
TIME...MOT...LOC 2054Z 308DEG 28KT 4415 9168

Kurz

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
410 PM CDT TUE JUN 29 2021

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

0404 PM     FUNNEL CLOUD     4 SW EASTMAN            43.12N 91.06W
06/29/2021                   CRAWFORD           WI   FIRE DEPT/RESCUE

&&

JAR

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
423 PM CDT TUE JUN 29 2021

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

0422 PM     HEAVY RAIN       EASTMAN                 43.17N 91.02W
06/29/2021  M4.18 INCH       CRAWFORD           WI   CO-OP OBSERVER

&&

JAR

Special Weather Statement
National Weather Service La Crosse WI
429 PM CDT Tue Jun 29 2021

WIZ033-034-041-292200-
Jackson-Trempealeau-La Crosse-
429 PM CDT Tue Jun 29 2021

...A STRONG THUNDERSTORM WILL AFFECT NORTHWESTERN LA CROSSE...
SOUTHWESTERN JACKSON AND SOUTHEASTERN TREMPEALEAU COUNTIES...

At 429 PM CDT, a strong thunderstorm was located over Galesville, or
12 miles southeast of Arcadia, moving east at 30 mph.

Winds in excess of 40 mph are possible with this storm.

Locations impacted include...
Holmen, Galesville, North Bend, County Roads M And W, Peacock Hill,
Mindoro, Camp Decorah, New Amsterdam, Stevenstown, Frenchville,
Council Bay and Camp Ehawee.

If outdoors, consider seeking shelter inside a building.

Torrential rainfall is also occurring with this storm, and may cause
localized flooding. Do not drive your vehicle through flooded
roadways.

LAT...LON 4405 9148 4418 9139 4412 9100 4391 9119
TIME...MOT...LOC 2129Z 289DEG 28KT 4411 9136

Kurz

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
442 PM CDT TUE JUN 29 2021

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

0438 PM     FUNNEL CLOUD     3 N WAUZEKA             43.13N 90.87W
06/29/2021                   CRAWFORD           WI   PUBLIC

            REPORTED AT HUSHER WAYSIDE PARK.

&&

Special Weather Statement
National Weather Service La Crosse WI
459 PM CDT Tue Jun 29 2021

WIZ041-042-292300-
La Crosse-Monroe-
459 PM CDT Tue Jun 29 2021

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT LA CROSSE AND MONROE
COUNTIES...

At 458 PM CDT, radar indicated strong thunderstorms were located
along a line extending from near North Bend to 6 miles northwest of
West Salem to Holmen. Movement was southeast at 20 mph.

Winds in excess of 35 mph are possible with these storms.

These storms will be near...
  West Salem around 530 PM CDT.
  Sparta around 545 PM CDT.
  Bangor around 550 PM CDT.
  Fort Mc Coy around 600 PM CDT.

Persons in campgrounds should consider seeking sturdy shelter until
these storms pass.

LAT...LON 4380 9068 4373 9099 4393 9137 4394 9136
      4397 9141 4401 9122 4407 9111 4407 9097
      4412 9097 4397 9040
TIME...MOT...LOC 2158Z 297DEG 14KT 4406 9102 4398 9114 4396 9126

JSB