023
FXUS63 KARX 111900
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
200 PM CDT Sat May 11 2024

.KEY MESSAGES...

- Warmer Sunday with afternoon-evening shower/storm chances (30-
  50%). Highs in the 80s with some mid 80s for some river
  valley/sandy locations. Gusty winds possible with any
  showers/storms.

- Cooler Monday with rain chances lingering (south of
  I-90-20-60% increasing toward DBQ).

- More rain chances for the end of the week with seasonably
  temperatures Tue-Thu and above normal temperatures Fri

&&

.DISCUSSION...
Issued at 144 PM CDT Sat May 11 2024

Overview:

Showers and thunderstorms with a cold front pushed through quickly
Friday afternoon and evening with rainfall amounts from a 0 to 0.20"
and wind gusts for some 25 to 45 mph.  Both Rochester and La Crosse
had a trace. Rochester gusted to 41 mph and La Crosse to 42 mph
at their respective airports. Skies cleared Friday night for a
spectacular extended viewing of the Aurora. Today, sunshine
continued high clouds moving in from the north and patches of
cumulus, especially over central Wisconsin. Temperatures were
in the 60s to around 70 early this afternoon.

Water vapor satellite imagery, 500mb heights, and lightning
showed a trough over the eastern Great Lakes with northwest
flow locally and an upstream shortwave over the Northwest
Territories/Nunavut and ripple over British Columbia. A closed
low pressure system was approaching the Four Corners region with
lightning ahead of the trough across parts of CO/NM/TX. The
11.12Z MPX sounding was 50 to 70% of normal with 0.38"
precipitable water.

Showers could clip parts of west central WI tonight-Warmer for
Sunday-Isolated/scattered showers with the cold front Sunday
afternoon/night - Gusty winds possible

Through Monday, we`ll see the Canadian storm system drop southeast
toward James Bay and the closed low over the Four Corner region
slowly progress eastward toward the Mid-Mississippi River Valley
region, trying to phase, and eventually heads toward IL/IN/OH/KY.
The forcing remains off to the north as a warm front moves in
overnight and the low level jet strengthens across northern MN into
northern WI.  There is a general increase in moisture transport into
Sunday with stronger magnitudes generally north tonight and east of
the area Sunday.  Temperatures warm Sunday into the 80s for most.
PWAT values do elevate to 100 to 175% of normal ahead of the cold
front passage Sunday with forecast soundings showing the moisture
mostly in the mid levels or higher. Overnight, a few showers could
clip areas north of HWY29. Lapse rates steepen for Sunday 8 to 9.5
deg. C. Theta-e advection increases ahead of the cold front with
SBCAPE of 500+J/kg. Deep layer shear values are mostly 25 to 30kts
but increase to 35kt for parts of central WI. The HiRes models show
isolated to scattered showers and thunderstorms ahead of and with
the cold frontal passage; mostly 20 to 50% Sunday afternoon and
evening.  Due to the steep lapse rates and convective temperatures
in the lower 80s could see gusty winds with any showers/storms.
Small hail possible with the higher deep layer shear/any
stronger storms; parts of central WI or farther east.

The progress of the cold front stalls as the closed mid-level low
moves into the Plains and tries to phase.  This will linger rain
chances into Monday south of I90 (20-60% increasing toward DBQ)

More rain chances for the end of the week; Seasonable Tue-Thu:

Mostly dry Tuesday and Wednesday with periodic rain chances
Wednesday through Friday night.  The next trough moves through the
Mississippi Valley Wednesday night and Thursday. Precipitation could
linger into Friday depending on how the stronger energy moves
through the trough.  Temperatures remain seasonable to mild in the
70s to lower 80s Wednesday through Friday.

&&

.AVIATION /18Z TAFS THROUGH 18Z SUNDAY/...
Issued at 1244 PM CDT Sat May 11 2024

A 500 mb shortwave will move across northern Minnesota and
northern Wisconsin late tonight and Sunday morning. This might
bring some showers to areas north of Interstate 94. Meanwhile,
for the TAF sites, it looks like it will mainly bring an
increase in high clouds.

West and northwest winds will gradually shift to south tonight
and southwest on Sunday morning. Wind speeds will be primarily
in the 10 to 20 knot range.

&&

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

&&

$$

DISCUSSION...Zapotocny
AVIATION...Boyne