131
FXUS63 KARX 161105
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
605 AM CDT Fri Aug 16 2024

.KEY MESSAGES...

- Showers and a few rumbles of thunder are likely (40-70%) this
  afternoon. These may (20-40%) return Saturday afternoon as
  well.

- Sunday through Thursday feature temperatures a bit below
  average. Depending on how the details shake out, each
  afternoon could presumably feature a stray shower, but no
  particular day stands out at this time.

&&

.DISCUSSION...
Issued at 341 AM CDT Fri Aug 16 2024

Friday and Saturday: Additional showers and thunderstorms

08z WV satellite clearly depicts an upper low churning to our north
over MN/WI. As the upper low slowly moves to the east today,
multiple shortwaves will rotate around this feature and pass over
the CWA. With a decent amount of moisture in place through the
column, these shortwaves should kick off numerous showers,
especially during the afternoon when surface heating, though
restrained by cloud cover, reaches a relative maximum. Progged
soundings depict skinny instability profiles suggesting thunder
coverage will be more limited, so have limited thunder mentions to
the isolated and scattered categories. As for other hazards, main
thing to watch this afternoon will be the potential for funnels and
a stray non-supercell tornado as the upper low approaches our
northern forecast area. While latest guidance suggests a lack of
larger scale surface boundaries and their associated surface
vorticity in our area, will need to closely monitor any stronger
updraft that develops on an outflow boundary this afternoon,
particularly in Taylor/Clark Counties.

Saturday, with the upper low slowly departing to the east,
additional upper disturbances may kick off more daytime convection.
While the risk for funnels should be lower, thunder remains possible
Saturday afternoon.

Sunday through Thursday: Below normal temperatures, low potential
for stray afternoon showers

Guidance continues to broadly depict northwesterly flow aloft
through the middle part of next week. This pattern usually leads to
temperatures running a bit below normal for mid to late August and
relatively uneventful weather, an outcome borne out as expected by
benign LREF joint CAPE/CIN/shear probabilities, longer term GEFS-
based ML outlooks, and most GEFS/ENS components remaining near
average. A stray afternoon shower or storm could presumably occur if
any well-timed shortwaves arrive but this appears to be a remote
possibility at this time.

&&

.AVIATION /12Z TAFS THROUGH 12Z SATURDAY/...
Issued at 600 AM CDT Fri Aug 16 2024

Messy 24 hours ahead for aviation interests. At issuance time,
fog and stratus are affecting areas roughly along and east of
the MS River, including LSE. Expect this to improve over the
next few hours with a brief window with VFR this morning. Then,
expect numerous showers to sweep west to east across the area
leading to MVFR ceilings. A rumble of thunder or two may occur
as well but, due to low confidence and predictability, have left
TS mentions out of the TAFs. Tonight, with plenty of moisture
around, expect IFR ceilings and perhaps fog.

&&

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

&&

$$

DISCUSSION...Ferguson
AVIATION...Ferguson