298
FXUS63 KARX 101154
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
654 AM CDT Thu Oct 10 2024

.KEY MESSAGES...

- A continued warming trend through Friday with highs in the 70s
  and lower 80s today and Friday.

- Relatively dry conditions persist through the rest of the week with
  precipitation chances (20-50%) returning east of the
  Mississippi River Saturday and Sunday.

- A more substantial cool down arrives Sunday with below normal
  temperatures into next week. Frost/freeze will be possible
  areawide with morning low temperatures falling near the
  freezing mark, particularly Tuesday morning.

&&

.DISCUSSION...
Issued at 310 AM CDT Thu Oct 10 2024

Warm Today and Tomorrow

07z WV satellite shows upper ridging over the west-central CONUS and
northeasterly flow aloft over the CWA with a shortwave embedded
within this flow over eastern Nebraska. At the surface, high
pressure is present to our east in the Great Lakes.

Today, expect heights aloft to build as the influence of the eastern
Nebraska shortwave wanes. The end result should be highs in the 70s
and, for areas west of the Mississippi River valley, potential (40-
80%) for a reading of at least 80.

Friday, 09.00z guidance is in good agreement that an upper wave with
an attendant cold front will arrive from the northwest during the
daytime hours. While exact timing continues to vary, trend across
past few runs of guidance has been to slow the arrival of the front
slightly, so am feeling more optimistic that the southern half of
the area will reach 80 before the front arrives. Indeed, 09.18z NBM
probabilities are now 40-90 percent to reach 80 in northeast Iowa
and southwest Wisconsin.

Weekend Rain Potential

Saturday into Sunday, second and much more potent upper wave will
dive southeast out of the Canadian Prairies to the Great Lakes,
bringing another cold frontal passage early Sunday. Guidance has
remained fairly consistent through the 09.00z cycle, suggesting dry
air around 750mb will likely prevent precip from reaching the ground
except areas in our northeast where much stronger dynamics will be
located. Even then, the chance for precip remains modest (20-50%)
with this potential now covering even less of our CWA. This struggle
with a lack of moisture should also serve to keep amounts low, with
even the 95th percentile rain amounts under 0.85". As for precip
type, progged 925mb temperatures and surface wet bulb temps remain
above freezing, so while NBM probability of seeing any snow has
ticked upward from 0 to 1 percent in Taylor County, this should be
an all rain affair.

Cooler Sunday through Wednesday

Sunday`s cold front will also shift temperatures to below normal
with highs mainly in the 50s Sunday through Tuesday and low to mid
60s next Wednesday. Morning lows Monday through Wednesday will be
cold enough for potential frost formation, with Tuesday morning
having a 60-80/80-95 percent chance for subfreezing lows west/east
of the Mississippi River.

&&

.AVIATION /12Z TAFS THROUGH 12Z FRIDAY/...
Issued at 700 AM CDT Thu Oct 10 2024

Higher low level pressure shifts off to the east today as a low
level trough progresses through the Northern Plains. Southerly
flow will increase as a result, concurrent with daytime
heating. VFR conditions expected across the forecast area from
southeast Minnesota, northeast Iowa, and western into central
Wisconsin for the 10.12Z TAF period.

&&

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

&&

$$

DISCUSSION...Ferguson
AVIATION...JAR