181
FXUS63 KARX 151010
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
510 AM CDT Wed May 15 2024

.KEY MESSAGES...

- Shower and storm chances increase across the forecast area
  tonight into Thursday. The risk for severe weather remains
  low.

- Increasing temperature trend into the end of the week/early
  weekend.

- Additional periods of showers and storms look possible into
  next week.

&&

.DISCUSSION...
Issued at 418 AM CDT Wed May 15 2024

Today - End of the Week:

Quieter conditions look to start the day before another system moves
through the region. This can be seen on current GOES satellite
imagery and RAP progs which show a shortwave tracking across the
Dakotas. This shortwave trough is then forecast to move across the
local region tonight into Thursday along with an associated surface
front. With sufficient forcing and increasing moisture, model
guidance shows scattered showers and perhaps a few storms developing
to the west and moving generally west/southwest to east/northeast
across the local forecast area tonight into early Thursday. Model
forecast soundings show some instability along with increasing low
level lapse rates which could help support some additional
convection development into the day on Thursday especially across
portions of Wisconsin. Although isolated storms cannot be ruled out,
the risk for severe weather remains low. Overall, HREF ensemble
probability-matched mean ending on Thursday night shows QPF
generally 0.10 to 0.25 inches across much of the area, with a few
localized areas of 0.25 to 0.5 inches.

The current forecast trends drier for most on Friday with
temperatures increasing into the upper 70s across the forecast area.

Weekend - Early Next Week:

Moving into the weekend, there does appears to be better
consensus on an upper level shortwave trough swinging across
the Northern Plains Friday night into Saturday before moving
across the local region late Saturday. Model guidance would
suggest some areas of rainfall developing in association with
this system and this seems to be reflected much better in the
latest blended model guidance. Even so, there are still some
differences in guidance revolving around specific details such
as timing and location of any developing convection. Will
continue to refine these details as confidence increases in the
coming days. While there is some spread, will mention that
ensemble solutions do also show a signal for increasing
temperatures into the early part of the weekend, with the
current forecast suggesting temperatures around 80 could be
possible for some by Saturday.

Into early next week, various shortwaves through the flow look to
bring potential for more showers and storms. However, timing and
location of these shortwaves remains of lower predictability at this
forecast range. Thus, will maintain blended model guidance for now.

&&

.AVIATION /12Z TAFS THROUGH 12Z THURSDAY/...
Issued at 510 AM CDT Wed May 15 2024

CIGS: gradual increase in high/mid level clouds from the west today
with a lowering of the deck moving into overnight as an upper level
weather system approaches the region. 00z HREF suggests some threat
for MVFR cigs moving in toward 09z Thu at KRST (50%), holding off
until after 12z for KLSE. RAP soundings showing something similar
but a few hours quicker. Will bring lower cigs to RST following RAP
timing, but hold off on KLSE for now.

WX/vsby: areas of -shra set to spread eastward across the region
with latest MESO models bringing them to KRST toward 06z Thu and 09z
for KLSE. Instability is weak "at best" and while there will be
small chances for a storm (20%), confidence not high enough to add
to the forecast.

WINDS: easterly through the day, becoming more southeast tonight.
Generally 10 kts or less. Deep afternoon mixing suggests some gusts,
but not a lot of wind to bring to the sfc, so mostly mid/upper
teens expected.

&&

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

&&

$$

DISCUSSION...EMS
AVIATION...Rieck