748
FXUS63 KARX 230849
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
349 AM CDT Sun Jun 23 2024

.KEY MESSAGES...

- Showers and thunderstorms return to the forecast Monday night
  and Tuesday, with a conditional risk for severe thunderstorms.
  A Slight Risk (level 2 of 5) for severe weather remains for
  Monday night and for a small portion of our southern counties
  on Tuesday.

- Another brief break for mid-week before additional shower and
  storm chances return late in the period. Details to be refined
  in the coming days.

&&

.DISCUSSION...
Issued at 349 AM CDT Sun Jun 23 2024

Today - Monday:

After a very active couple of days, it looks like we are finally
getting a much quieter end to the weekend. Current satellite water
vapor imagery and RAP progs show a shortwave dropping down from
Canada towards northern Minnesota. This wave is forecast to continue
down and eventually across the Great Lakes through the day. This
along with daytime heating may allow for some isolated showers
(perhaps a storm) to develop this afternoon, especially to the
north. Otherwise, expecting a much drier day for most with highs
mainly in the 70s to low 80s for a few. Surface high pressure slides
across the region Sunday night with drier conditions and increasing
temperatures (80s) into Monday. Take advantage of the next couple of
days as showers and thunderstorm chances make a return to the
forecast.

Monday Night - Tuesday:

An upper level shortwave trough and attendant surface low are
forecast to move eastward across portions of Canada Monday into
Tuesday. The aforementioned surface high pressure passes through on
Monday and southerly flow sets in, with increasing moisture and warm
advection across the area. With this and an increasing low level jet
Monday night, model guidance suggests the potential for showers and
storms to develop. Given the thermodynamic environment guidance
shows quite strong instability building in, which would generally be
supportive of strong to severe storms. However, there still remains
quite a bit of uncertainty revolving around storm coverage and
evolution, with model forecast soundings showing a stout cap in
place. With this the risk for severe weather remains a challenge and
likely conditional with some details still unclear. For now, SPC has
maintained a Slight Risk (level 2 of 5) for severe weather across
northern portions of the forecast area.

As the shortwave trough continues to track across Canada Tuesday, an
associated cold front is forecast to move across the region. This
may become a focus for further showers and thunderstorms to develop
Tuesday. However, how this all evolves will likely depend greatly on
how the Monday night storms evolve. At this time much of the area
remains in a Marginal Risk (1 of 5) for severe weather, with a small
portion of northeastern Iowa and southwestern Wisconsin counties
just within a Slight Risk (2 of 5) for Tuesday.

Mid-week onward:

Behind the early week systems, a bit cooler temperatures (70s to
around 80) and another much needed break in showers and
thunderstorms looks to come for mid-week. However, another
system is forecast to track across the northern Plains bringing
this break to an end. Plenty of variability among ensemble
solutions still exists this far out, so stay tuned as we refine
the details over the coming days.


&&

.AVIATION /06Z TAFS THROUGH 06Z MONDAY/...
Issued at 1005 PM CDT Sat Jun 22 2024

The light rain and drizzle should exit the KLSE area by the
start of the TAF period. Low level moisture continues to affect
the TAF sites overnight with reinforcing cold air behind the
initial cold frontal passage. Variable ceilings with MVFR and
patchy IFR ceilings prevailing until conditions improve Sunday
with VFR ceilings scattering out later Sunday. A few showers
will be possible Sunday. For now left them out with the
RAP/HRRR on the drier side. Northwest winds 5 to 15kts
continue.

&&

.HYDROLOGY...
Issued at 124 PM CDT Sat Jun 22 2024

Have cancelled additional parts of the Areal Flood Watch in
southeast Minnesota and west-central Wisconsin as the heavy rain
threat appears diminished for these areas. However, with
additional heavy rainfall possibly bringing another 2 to 4
inches this afternoon across northeast Iowa and southwest
Wisconsin, the Areal Flood Watch continues for these areas
through this evening.

River flooding concerns will last well into next week and
multiple rivers could exceed moderate flood stage if the
rainfall lines up correctly in their basins. Abundant rainfall
fell in the Cedar River basin around Austin, leading to major
flooding in this area. This appears likely to cause major
flooding downstream at Charles City, with exact crest height
dependent on how much additional rainfall falls in the basin
this afternoon.

&&

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

&&

$$

DISCUSSION...EMS
AVIATION...Zapotocny
HYDROLOGY...Ferguson