Severe Thunderstorm Warning 26, NWS La Crosse, WI

947 
WWUS53 KARX 212000
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
300 PM CDT Sun Jun 21 2020

IAC043-212030-
/O.CON.KARX.SV.W.0026.000000T0000Z-200621T2030Z/
Clayton IA-
300 PM CDT Sun Jun 21 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 330 PM CDT
FOR SOUTHWESTERN CLAYTON COUNTY...

At 259 PM CDT, a severe thunderstorm was located near Osborne, 
moving northeast at 15 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

This severe thunderstorm will remain over mainly rural areas of
southwestern Clayton County, including the following locations... 
Mederville, Garber, Motor, Communia, Clayton Center, and St. Olaf. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Prepare immediately for large hail and deadly cloud to ground
lightning. Seek shelter inside a well-built structure. Stay away from
windows.

&&

LAT...LON 4279 9152 4286 9156 4298 9133 4273 9117
      4267 9145
TIME...MOT...LOC 1959Z 254DEG 12KT 4278 9139 

HAIL...1.00IN
WIND...<50MPH
 
$$

04

543 
WWUS53 KARX 212013
SVSARX

Severe Weather Statement
National Weather Service La Crosse WI
313 PM CDT Sun Jun 21 2020

IAC043-212023-
/O.CAN.KARX.SV.W.0026.000000T0000Z-200621T2030Z/
Clayton IA-
313 PM CDT Sun Jun 21 2020

...THE SEVERE THUNDERSTORM WARNING FOR SOUTHWESTERN CLAYTON COUNTY 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 heavy rain is
still possible with this thunderstorm.

LAT...LON 4279 9152 4286 9156 4298 9133 4273 9117
      4267 9145
TIME...MOT...LOC 2009Z 245DEG 11KT 4280 9134 

$$

04

Area Forecast Discussion
National Weather Service La Crosse WI
1239 PM CDT Sun Jun 21 2020

.SHORT TERM...(Today and tonight)
Issued at 410 AM CDT Sun Jun 21 2020

Watching areas of locally dense river valley fog this morning, as
lingering moisture, light surface flow, and mostly clear skies have
allowed decent radiational cooling. Pretty impressive so close to
the longest day of the year, but with sunrise rapidly approaching,
expect this fog to burn off by around 8 am.

Much of the rest of the day could end up dry for most, with the
exception being portions of northeast Iowa, where approaching low-
level moisture transport this morning could result in scattered
showers and storms. Coverage is expected to increase late this
afternoon as moisture transport ramps up further. Attention then
turns to a shortwave/front approaching from the west. Sunshine over
much of the area should allow 1500-2000 J/kg of MUCAPE to develop by
afternoon, but shear looks marginal at only around 20 to maybe 30
kts. Forcing and shear will be stronger to our west where storms
initiate, moving eastward into western parts of the area by evening.
Instability will be waning as the evening progresses, but will have
to watch for strong to perhaps severe storms maintaining some of
their strength as they enter western portions of the area before
weakening. SPC slight risk matches this well, just touching our
western border. In addition, with recent hefty rainfall totals over
parts of the area and continued deep warm cloud depths/high
precipitable water exceeding 1.5", will have to monitor for locally
heavy rain or localized flooding. Latest guidance suggests portions
of northeast Iowa, where contribution from earlier day rain and wet
soils could overlap with evening storms, will have the greatest
potential for heavy rain.

.LONG TERM...(Monday through Saturday)
Issued at 410 AM CDT Sun Jun 21 2020

Still watching Monday for potential for a strong storm or two.
Timing does not look favorable for strong storms for most of the
area, as the front looks to swing through during the morning. The
exception looks to be extreme northeast Iowa into southwest
Wisconsin where the front might not yet have passed by afternoon.
Guidance does not suggest very impressive 0-6 km shear, and cloud
cover/morning showers may really hamper the ability to build much
instability here, both of which would limit the threat for strong
storms. That said, if skies are clearer than anticipated and a tad
more instability is able to build, a strong storm or two would be
possible as the front moves through.

Following the frontal passage, an upper level low just to our north
will keep the area in cooler northwest flow aloft, translating to
highs in the 70s to around 80, and lows in the 50s. Within this flow
there will be weak shortwaves rotating into the area through the
week, however, which may lead to occasional shower chances. By the
end of the week, the low moves off as a stronger shortwave swings in
from the west, bringing more shower/storm chances. There are some
suggestions that warmer air and upper level ridging then try to take
hold for early next week, but model differences abound and
predictability is low.

&&

.AVIATION...(For the 18Z TAFS through 18Z Monday afternoon)
Issued at 1211 PM CDT Sun Jun 21 2020

VFR conditions continue this afternoon with a fair weather cu
field developing and a south-southwest breeze. Instability
continues to increase with all of today's sunshine, so monitoring
for any possible source of lift to trigger potential showers and
storms. If this occurs this afternoon, development to isolated
weak thunderstorms would be quick, but likelihood of this
occurring in vicinity of the airfields is low. Main focus will be
this evening as an upper disturbance approaches, which is expected
to trigger a cluster of storms upstream later this afternoon from
northeast NE into southwest MN. Hi-res models are in general
agreement with this band of convection then pushing into the
local area roughly between 00Z - 03Z, but they still show a rather
large spread in terms of timing and evolution this evening.
Confidence at this point is high enough for at least scattered
storms to warrant tempo TSRA this evening with cig/vsby reductions
likely with any heavy rain. Could also be some gusty winds with
variable wind direction. Trends seem to favor convection and
lingering showers clearing out of RST more quickly than LSE
overnight, but confidence is lower that far out in the period.

There are hints of lowering ceilings as a cold front approaches
late tonight towards daybreak Monday with low end MVFR to perhaps IFR
possible. Light and variable winds overnight will quickly shift
to the north-northwest behind the front Monday morning. There may
be some showers that develop along the front towards the tail end
of the TAF period, but confidence is low.

&&

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

SHORT TERM...Lee
LONG TERM...Lee
AVIATION...Kurz

Hazardous Weather Outlook
National Weather Service La Crosse WI
511 AM CDT Sun Jun 21 2020

IAZ008>011-018-019-029-030-MNZ079-086>088-094>096-WIZ017-029-
032>034-041>044-053>055-061-221015-
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-
511 AM CDT Sun Jun 21 2020

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 this morning across portions
of northeast Iowa. The main hazard is lightning.

Additional storms are expected this afternoon into tonight. A few
may be strong to isolated severe across northeast Iowa and
southeast Minnesota, with the main hazards being gusty winds and
small hail. Locally heavy rainfall is also possible this afternoon
through tonight. This could lead to rises on some rivers and
localized flooding.

.DAYS TWO THROUGH SEVEN...Monday through Saturday

Periodic thunderstorm chances will continue through the week. The
probability of organized severe weather looks low at this time.

.SPOTTER INFORMATION STATEMENT...

No action needed.

.EMERGENCY MANAGEMENT COORDINATION...

No webinar is scheduled.

Lee

Special Weather Statement
National Weather Service La Crosse WI
148 PM CDT Sun Jun 21 2020

IAZ029-211930-
Fayette-
148 PM CDT Sun Jun 21 2020

...A STRONG THUNDERSTORM WILL AFFECT SOUTH CENTRAL FAYETTE COUNTY...

At 147 PM CDT, a strong thunderstorm was located over Fairbank, or
near Oelwein, moving northeast at 15 mph.

Winds in excess of 40 mph and half inch hail are possible with this
storm.

Locations impacted include...
Oelwein, County Roads 3 And W 13 and County Roads 3 And W 33.

If outdoors, seek shelter inside a building.

This storm may intensify, so be certain to monitor local radio
stations and available television stations for additional information
and possible warnings from the National Weather Service.

LAT...LON 4264 9205 4278 9194 4273 9174 4264 9188
TIME...MOT...LOC 1847Z 226DEG 14KT 4262 9200

Kurz

Special Weather Statement
National Weather Service La Crosse WI
235 PM CDT Sun Jun 21 2020

IAZ030-212000-
Clayton-
235 PM CDT Sun Jun 21 2020

...AN AREA OF STRONG THUNDERSTORMS WILL AFFECT SOUTHERN CLAYTON
COUNTY...

At 233 PM CDT, strong thunderstorms were clustered near Volga, or
southwest of Elkader, moving northeast at 15 mph.

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

Locations impacted include...
Elkader, Volga, St. Olaf, Garber, Elkport, Mederville, Osborne,
Littleport, Communia and Clayton Center.

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

LAT...LON 4281 9161 4284 9161 4298 9131 4273 9116
      4266 9151
TIME...MOT...LOC 1933Z 245DEG 11KT 4278 9148

04