Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 100258

Area Forecast Discussion
National Weather Service La Crosse WI
1000 PM CDT Thu Apr 9 2020

.SHORT TERM...(This evening through Friday)
Issued at 225 PM CDT Thu Apr 9 2020

Water vapor satellite early this afternoon shows a potent short
wave trough moving across the Upper Midwest. This wave is
responsible for generating the widespread snow/rain showers across
the area. This activity is expected to dissipate rather quickly
very late this afternoon into the early evening as the short wave
trough moves past the area allowing the forcing/lift to diminish.
Also, the steep low level lapse rates will begin to decrease
cutting off the instability and the deep mixing. This should
pretty much allow all the showers to dissipate by 9 or 10 pm.
After that, the clouds should also dissipate rather quickly
leaving behind mostly clear skies as an area of high pressure
moves from the west. While the center of the high will slip south
of the area Friday, the northern extent of the ridge axis will
slide across the area. This will allow for a sunny start to the
day followed by a general increase in the cloud cover during the
afternoon but it will be dry day.

.LONG TERM...(Friday night through Thursday)
Issued at 225 PM CDT Thu Apr 9 2020

Dry conditions are expected Friday evening into Saturday. For the
rest of the weekend, model guidance is still on track for a low
pressure system to impact the region into the start of the work
week. Warming ahead of this system will bring Saturday afternoon
temperatures into the low 50s. Precipitation will start out as
mainly rain. However, temperatures will drop near and below freezing
in association with the passing cold front Sunday night.
Accumulating snow is expected into Monday morning before the system
exits the region.

The exact location of the heaviest snow band is highly uncertain at
this time. GEFS plumes have snow totals in the 1-4" range across
the region. Plenty of moisture is with this system as the mean
GEFS 24 hour QPF amounts are above the 95th percentile for Sunday
into Monday. Details will become more clear when the system draws
near as the location for the snow band will depend on how far
south the upper low tracks into northern Mexico.

Behind this system, colder than normal temperatures are expected.
Temperatures from 850 mb to the mid levels of the atmosphere are
around 2 to 3 standard anomalies cooler than what would typically
occur this time of year. Through mid-week, afternoon temperatures
are expected to be in the upper 30s to mid 40s, and lows cool
down into the teens and 20s.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1000 PM CDT Thu Apr 9 2020

Cigs: 5-6kft deck of clouds dropping south across WI at late
evening, with meso models all suggestion the mass will shift east
overnight. However, satellite trends support bringing at least a few
hours of bkn cigs to KLSE, and have already added to the forecast.
Most of this should push east by 06z though. The rest of tonight/Fri
morning looks clear, with high clouds filtering in from the west in
the afternoon, associated with bits of upper level shortwave energy.

WX/vsby: no impacts anticipated.

Winds: northwest winds holding mostly around 10 kts through the rest
of the night/Fri, with some swing to more westerly later Fri





LONG TERM...Peters
AVIATION....Rieck is the U.S. government's official web portal to all federal, state and local government web resources and services.