730
FXUS63 KARX 140823
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
323 AM CDT Tue May 14 2024

.KEY MESSAGES...

- Wildfire smoke continues to impact the area with some hazy/milky
  skies overhead today.

- Rain chances increase late Wednesday night into Thursday
  (35-55% probs for 24-hr QPF >=0.25").

- Additional periodic shower and storm chances forecast through
  the weekend.

&&

.DISCUSSION...
Issued at 323 AM CDT Tue May 14 2024

Hazy/Milky Skies & Low Precip Chances South (Early) Today:

GOES satellite imagery and RAP progs around 07Z showed an upper
level low generally over Missouri, with a few showers still
spread across portions of Iowa into Missouri and Illinois.
Latest hi-res guidance would continue to keep the majority of
showers south of the local forecast area, but have noticed some
echos developing along portions of southwestern Wisconsin. Have
maintained some small precipitation chances along our south to
reflect current observations and guidance from latest hi-res
models.

The aforementioned system is expected to continue to slowly shift
eastward. With winds turning more northeast/east latest HRRR/RAP-
Smoke guidance suggests highest concentrations of near-surface smoke
will continue to push southwest/west of the local area for today.
Though, increased concentrations of smoke aloft will still keep some
milky skies around.

Mid-week Precipitation Chances:

Model guidance suggests shortwave ridging may be in place for the
early part of the day Wednesday before shifting eastward. A
shortwave trough is forecast to move behind it across the Northern
Plains as shortwave energy moving out from the Southern Plains
ejects towards the Mid Mississippi Valley. With some increasing
moisture and limited instability ahead of the associated
surface front, scattered showers and storms are forecast to move
across the area. Latest blended model guidance has slightly
slowed down the arrival of the showers and storms into the
overnight hours Wednesday, with increasing chances (40-70%) into
the day Thursday. Right now the risk for severe storms
continues to be low for the local forecast area, but will
continue to monitor conditions.

Additional Precip Chances End of Week - Weekend:

The upper level pattern appears to remain progressive through the
period as various shortwaves move through. However, significant
differences in details are still noted between ensemble solutions,
lowering overall confidence in timing and location of any
shower and storm chances. In turn, the NBM maintains broad rain
chances (20-40%) over the region through the period and we will
hold with these for now until details can be refined further.
There is also some signal in ensemble guidance for a slight
increase in temps across the region for the start of the
weekend, with perhaps some potential to see highs into the
mid/upper 70s to near 80. However, temperature spread does
increase into the weekend as well. Overall, will continue to
iron out the details in the coming days as confidence increases.

&&

.AVIATION /06Z TAFS THROUGH 06Z WEDNESDAY/...
Issued at 1037 PM CDT Mon May 13 2024

VFR conditions are expected through the TAF period with some high
cirrus and some smoke aloft. Any remaining surface smoke will move
out of the region early in the TAF period with increasing easterly
surface winds into the morning and afternoon hours to around 10
kts. A disturbance passing to our south may bring in a shower
or two into portions of northeast Iowa and southwestern
Wisconsin overnight and into the morning hours on Tuesday
however both TAF sites are expected remain dry. Winds will begin
to diminish during the evening on Tuesday to around 5 kts as
diurnal mixing begins to wane.

&&

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

&&

$$

DISCUSSION...EMS
AVIATION...Naylor