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000
FXUS63 KARX 171922
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
222 PM CDT Wed Apr 17 2024

.KEY MESSAGES...

- Chance for rain tonight into Thursday (0.1"+ 10-20% North
  towards Taylor Co. to 75 to 95% parts of northeast
  IA/southwest WI).

- Gusty winds return Friday with gusts between 30 and 45mph.
  Strongest winds in SE Minnesota and NE Iowa.

- Colder temperatures for the weekend with highs in the 40s on
  Saturday and at or below freezing temperatures likely on
  Saturday and Sunday mornings.


&&

.DISCUSSION...
Issued at 221 PM CDT Wed Apr 17 2024

Much of the local area received a good soaking of rain with .5 to
1.5 inches of rainfall with some local 2 to 3 inch amounts. Here
at the NWS La Crosse, we had 1.18 inches. Parts of northeast
Iowa had the higher amounts with 2.7 at Elkader 5NW. RST had
0.75" and LSE had 0.75". Water vapor satellite imagery and
heights showed the 500mb trough moving across WI with the next
area of closed low pressure over Manitoba. Conditions were
cloudy areawide with the first storm system still in the area
with a few showers east of I94. A break in the clouds was noted
in-between system over the Plains, however additional clouds
were already building in across South Dakota. Rain and snow were
already being reported in the Rapid City area. Gusty northwest
winds were occurring today 20 to 40 mph with some stronger winds
aloft mixing down. At 2pm...temperatures were mostly in the
50s.

More Rain Thursday:

Upper level low moving south from Canada with an associated surface
low. However this surface low does not form beneath the upper level
low, it forms well south in Kansas. This surface low will move
northeast towards our CWA but will stay to the south. There will be
an area of higher frontogenesis north of the low that will be the
area of focus for some lift to occur. Moisture advection is not
strong. The bulk of the moisture and lift will be focused further
south, but an area north of the surface low, in the deformation
region of the low, is where precipitation would occur. Current
guidance has the best chance of precipitation along and south of I-
90. QPF probabilities of 0.15" occurring south of I-90 are highest,
while north of I-90 has only a 10 to 30% chance of reaching 0.15".

Gusty Winds Friday:

With the passage of the upper level low on Friday, the pressure
gradient will become tight resulting in strong northwest winds
through the day. Current guidance has gusts between 30 and 45 mph,
with the stronger gusts in southeastern Minnesota and northeast
Iowa. Mostly clear skies are expected Friday so there is potential
for stronger winds to mix down.

Cooler Weather for the Weekend:

Ensemble and deterministic guidance continue to show colder air
moving down from Canada. This colder air would stick around through
the weekend. High temperatures for Saturday look to be between 10F
and 15F below normal with highs in the mid to upper 40s. Low
temperatures for Friday through Monday are expected to be in the low
to mid 30s, with the best chance of below freezing temperatures
occurring Saturday and Sunday morning. With these temperatures,
frost/freeze products may need to be issued depending on cloud cover
and winds.

&&

.AVIATION /18Z TAFS THROUGH 18Z THURSDAY/...
Issued at 103 PM CDT Wed Apr 17 2024

MVFR conditions will improve to VFR as the storm system pulls
away from the local area this evening. This will be short-lived
as clouds will deteriorate already later tonight as the next
weather system brings increasing rain chances after midnight
with the potential for MVFR conditions redeveloping with the
steadier showers. Northwest winds 15 to 25kts with gusts 25
to 35kts today decrease early this evening to less than 12kts.

&&

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

&&

$$

DISCUSSION...Cecava/Zapotocny
AVIATION...Zapotocny