559
FXUS63 KARX 312013
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
313 PM CDT Thu Oct 31 2024

.KEY MESSAGES...

- Lingering light precip through this evening. Some light snow may
  occur along and north of an Austin to Neillsville line but
  accumulations, if any, will be under 1".

- Dry weather expected Friday and Saturday. A more active
  pattern with increasing precipitation chances is expected
  Sunday through early next week.

&&

.DISCUSSION...
Issued at 312 PM CDT Thu Oct 31 2024

Light precip this afternoon and evening

19z WV satellite reveals an upper low centered roughly over EAU with
a noted dry slot extending over NE IA into central WI. At the
surface, cold front has pushed through the CWA with breezy west-
northwesterly winds occurring across the southern two thirds of the
area with gusts mainly to 40 mph with sporadic 45 mph gusts.
Temperatures are in the mid 30s to mid 40s. Spotty light precip is
ongoing mainly along and north of I-90. Most stations continue to
report rain while Dodge Center switched to snow within the last
hour. Northwest of the CWA, more consistent precip coverage is seen
courtesy of a 925/850mb frontogenetic zone with this largely falling
as snow given the cooler temperature profiles there.

This afternoon into tonight, expect the aforementioned spotty light
precip to continue roughly around and north of I-90 before
eventually tapering off west to east as additional shortwaves rotate
around the upper low. On the subject of precip type, progged
soundings suggest snow will increasingly be seen north and west of
an Austin to Neillsville line as profiles cool under the influence
of the west-northwesterly low level CAA. Best area for more
consistent precip looks to be northwest of a Dodge Center MN to
Greenwood WI line as the influence of the 925/850mb frontogenetic
axis may help enhance precip totals somewhat. While more consistent
precip - and potentially snow - may thus be seen there, progged
soundings show relatively dry conditions through the deeper column,
in particular the dendritic growth zone. Thus, while 31.12z HREF
probabilities based on a 10:1 ratio point to a 40% chance to reach
1" of accumulation in Taylor County, am inclined to think these are
overdone and accumulations, if any, will remain scant.

Rain next week

Robust agreement is seen across GFS/EC/CMC and their respective
ensembles that a longwave upper trough will slowly slide eastward
over the central CONUS Sunday through Tuesday, bringing multiple
shots at precip as various lead impulses and then the main body of
the trough itself arrive from the west. While exact timing across
guidance varies, signal is good enough for multiple periods with 70-
95 PoPs. Progged temperature profiles suggests this will be an all
rain affair and so does 31.00z LREF, which has a less than 10
percent chance for measurable snow throughout early next week. As
for rain amounts, total moisture with this system looks to approach
the 99th percentile across model climate, with the probability for
over 2" across the entire extended rain event greater than 50% in
some locations, particularly SW WI. Ensemble means and cluster
analysis driven means both suggest the best potential for 3+" will
reside to our southeast but even then, cannot rule out this
potential for Grant County. Will need to watch the evolution of this
system closely, particularly with regards to rain impacts in SW WI.

&&

.AVIATION /18Z TAFS THROUGH 18Z FRIDAY/...
Issued at 1247 PM CDT Thu Oct 31 2024

Winds will continue to shift to the northwest for the rest of
the day as the center of a surface low moves through the area.
Wind gusts through the afternoon will be between 30 and 45 mph.
These gusts will diminish this evening and winds are expected to
become light and southerly for the overnight period. MVFR/IFR
ceilings are expected to continue into the evening until these
clouds shift off to the northeast. Light rain will continue
to be possible through the afternoon, especially areas along
and north of I-90. Some light snow is also possible along and
northwest of an Austin, Minnesota to Neillsville, Wisconsin
line.

&&

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

&&

$$

DISCUSSION...Ferguson
AVIATION...Cecava