504
FXUS63 KARX 092337
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
637 PM CDT Tue Jul 9 2024

.KEY MESSAGES...

- Isolated to scattered showers and storms possible through
  Thursday. Impacts look to remain minimal, with plenty of dry
  hours for most.

- Monitoring storm potential into the weekend and early next
  week. Otherwise, temperatures will be on an increasing trend
  with highs in the mid 80s to around 90 degrees for some
  Sunday and Monday.

&&

.DISCUSSION...
Issued at 235 PM CDT Tue Jul 9 2024

This Afternoon - Thursday:

A bit quieter of a morning across the local area, with the remnants
of Beryl a main feature for the day. This system will continue
to track northeastward, but looks to remain well southeast of
the local area keeping main impacts locally not much more than
some high level clouds. There remains low (10-20%) chances for
isolated showers this afternoon and evening. However, with not
much for a lifting mechanism today, impacts look to be limited
with coverage of any showers/storms much lower than previous
days.

Stronger forcing looks to come Wednesday as a shortwave drops down
across the region. There continues to be some signal in latest hi-
res model guidance for showers and storms around for the morning
hours Wednesday, with increasing chances (30-50% mainly across
portions of SE MN/NE IA) into the day. As with previous days,
impacts look to be limited with marginal instability and lack of
stronger shear. In addition, widespread heavy rain is not expected,
but localized amount of 1-2" cannot be ruled out underneath any
slower moving storm. However, 09.12Z HREF shows the highest signal
for this generally along/west of a Dodge county to Fayette county
line. For Thursday, we remain on the western edge of the upper level
trough/low. With building diurnal instability could see some low
chances for isolated showers and storms to develop in our east.

Friday - Early Next Week:

Model guidance seems to be in good overall agreement on a pattern
shift as the Great Lakes trough weakens and upper level high
pressure remains over the West. This leaves the region under
northwest flow, with guidance suggesting various shortwaves moving
along the northern side of the upper level ridge. As was
mentioned with the previous forecast, concerns revolve around a
favorable environment for the development of organized MCS
activity. However, there remains lower predictability in the
timing and location of any shortwaves at this time frame, along
with lower confidence around any capping/inhibition impacts.
Will be something to keep an eye on in the coming days as
00Z CSU severe probability forecasts do highlight the region
over the weekend into early next week (highest 15-25% Sunday &
Monday).

Otherwise, signal continues to show high confidence in above average
temperatures into the weekend, with low temperature spread
among blended model guidance solutions. Currently, highs are
forecast to reach into the mid 80s to potentially low 90s for
some (NBM probs >50% along parts of the MS River Valley). With
increasing dewpoint temperatures as well, heat indices may begin
to reach into the mid to upper 90s Sunday and potentially again
Monday.

&&

.AVIATION /00Z TAFS THROUGH 00Z THURSDAY/...
Issued at 631 PM CDT Tue Jul 9 2024

Primary concerns over the next 24 hours are the potential for
valley fog early Wednesday morning and the potential for showers
and thunderstorms, both over the next few hours and again
tomorrow. Probability for TS at RST has decreased further based
on latest observational trends to around 10%, so have kept
mentions out for this afternoon. However, moving ahead to the
morning, probability for shower appears to be around 30-40% with
a 20% chance for TS, so have included a VCSH mention with this
update. As for valley fog, abundant cirrus should help limit
formation so have continued to leave this out of the LSE TAF.

&&

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

&&

$$

DISCUSSION...EMS
AVIATION...Ferguson