824
FXUS63 KARX 161654
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1150 AM CDT Tue Jul 16 2024

.KEY MESSAGES...

- A much drier, cooler and less humid stretch of weather is
  expected for the rest of the week with little to no impactful
  rainfall expected through the weekend.

&&

.DISCUSSION...
Issued at 246 AM CDT Tue Jul 16 2024

Today-Wednesday:

After multiple rounds of storms over the past few days and warm to
hot, muggy summer weather, a much cooler, drier airmass will
overspread the Upper Midwest over the coming days in the wake of
cold front passing south and east of the region early today.
Low-level cold advection will continue through the day as deep
north/northwest flow sharpens in response to an upper trough
swinging south across the Great Lakes today into Wednesday. With
steep low-level lapse rates, cooling mid-levels and a streamer
of vorticity dropping south this afternoon, a few showers
(15-25% chance) are possible. With only weak, skinny CAPE above
the freezing level at best per RAP soundings, thunder chances
look very low. Any showers will likely diminish with loss of
heating late in the day. By tomorrow, highs likely will reach
only the 70s for most locations with diurnal cumulus development
expected beneath the mid-level cold pool/western flank of the
large upper trough.

Thursday-Monday:

A Canadian surface high will influence the region for late week into
the weekend, resulting in mainly dry, seasonably cool conditions
with low humidity levels for mid-July. NAEFS precipitable water
values fall below the 10th percentile relative to climo late this
week. Meanwhile, there are indications the upper flow will stagnate
late week into the weekend with the upper level ridge across
the West and lower heights/troughing developing across the Mid
Mississippi Valley. Some early morning valley fog development is
possible during this time with indications of an extended
period of weak boundary layer flow. The coolest air is expected
through mid to late week with highs in the 70s/near 80 followed
by a slow rebound in temps back into the 80s in spots by the
weekend into early next week. However, through the forecast
period, temps should remain near to below average. Global
ensemble distributions (GEFS/EPS/CMC) show fairly low spread in
high temps right through the middle of next week. Some low-end
rain chances are possible by the weekend, but given the blocked,
weak flow pattern with low predictability of any weak waves and
tendency for surface high pressure to persist, confidence in
much, if any, impactful precip over the coming week is low.

&&

.AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/...
Issued at 1150 AM CDT Tue Jul 16 2024

CIGS: sct-bkn VFR this afternoon as diurnal heating helps lift some
pockets of MVFR. Mostly skc/sct tonight into Wed.

WX/vsby: could see an isolated sprinkle this afternoon, but minimal
if any sensible weather impacts expected.

WINDS: north/northwesterly and generally hugging at/below 10 kts.


&&

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

&&

$$

DISCUSSION...JM
AVIATION.....Rieck