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.

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE LA CROSSE WI
1228 PM CDT TUE JUN 29 2021

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

1200 PM     FLOOD            6 N PRAIRIE DU CHIEN    43.12N 91.14W
06/29/2021                   CRAWFORD           WI   LAW ENFORCEMENT

            ABOUT A FOOT OF WATER REPORTED ON PART OF
            HWY 35 NEAR COUNTY ROAD N.

&&

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

WIZ029-032>034-291930-
Buffalo-Jackson-Trempealeau-Clark-
131 PM CDT Tue Jun 29 2021

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT PARTS OF WESTERN
WISCONSIN...

At 129 PM CDT, radar indicated a line of thunderstorms from near
Alma to Medford, moving east at 50 mph.

Winds in excess of 30 mph are possible with these storms along with
frequent lightning. If you have outdoor plans over the next several
hours, have an option to move indoors or a good shelter.

Locations impacted include...
Neillsville, Whitehall, Osseo, Thorp, Independence, Loyal, Strum,
Greenwood, Owen, Price, Humbird, Hatfield, Longwood, Eleva,
Northfield and Merrillan.

LAT...LON 4503 9032 4434 9032 4432 9190 4460 9149
      4460 9092 4499 9091
TIME...MOT...LOC 1829Z 250DEG 51KT 4501 9033 4448 9136

Shea

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

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

0125 PM     FLASH FLOOD      6 WSW EASTMAN           43.14N 91.14W
06/29/2021                   CRAWFORD           WI   LAW ENFORCEMENT

            HWY 35 CLOSED BETWEEN COUNTY ROAD D AND
            COUNTY ROAD N DUE TO HIGH WATER, MUD AND
            ROCKSLIDES.

&&

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

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

0130 PM     FLASH FLOOD      WAUKON JCT              43.16N 91.19W
06/29/2021                   ALLAMAKEE          IA   EMERGENCY MNGR

            MUDSLIDES, FLOODED ROADS, AND FLOWING
            WATERS.

&&

KAA

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

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

0125 PM     FLASH FLOOD      6 WSW EASTMAN           43.14N 91.14W
06/29/2021                   CRAWFORD           WI   LAW ENFORCEMENT

            CORRECTED ROAD NAME FROM PREVIOUS LSR. HWY
            35 CLOSED BETWEEN COUNTY ROAD D AND COUNTY
            ROAD K DUE TO HIGH WATER, MUD AND
            ROCKSLIDES.

&&

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

WIZ029-034-292000-
Jackson-Clark-
229 PM CDT Tue Jun 29 2021

...A LINE OF STRONG THUNDERSTORMS WILL AFFECT SOUTHERN CLARK AND
CENTRAL JACKSON COUNTIES...

At 228 PM CDT, radar indicated strong thunderstorms were located
along a line extending from near Spencer to 7 miles northwest of
Black River Falls. Movement was east at 35 mph.

Winds in excess of 30 mph are possible with these storms.

Locations impacted include...
Neillsville, Loyal, Hatfield, Shortville, Lynn, Merrillan, Alma
Center, Hixton, Granton, City Point, Ballard Road And Pray Avenue,
Wildcat Mound, Christie, Bruce Mound, Chili, East Fork Campground,
Chili Corners, Veefkind, Lake Arbutus and The Cunningham Airfield.

This includes Interstate 94 between mile markers 104 and 107.

If outdoors, consider seeking shelter inside a building.

LAT...LON 4437 9108 4483 9032 4435 9032
TIME...MOT...LOC 1928Z 256DEG 31KT 4481 9029 4439 9094

Kurz