Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 111139 CCA

Area Forecast Discussion
National Weather Service La Crosse WI
635 AM CDT Sun Mar 11 2018

.SHORT TERM...(Today and tonight)
Issued at 302 AM CST Sun Mar 11 2018

Fairly potent mid-level vorticity maximum evident on GOES-East was
rotating southeast through eastern NE/western Ia early this morning.
Stretching deformation axis north of this feature was producing a
band of light snow across portions of southeast MN and northeast IA.
A call to law enforcement in Mower MN indicated around 1/2 inch has
fallen. Meanwhile, the rest of the area was under a veil of mid/high
level cloud cover. Temperatures across the area as of 1 am were
in the middle 20s to the lower 30s.

For today, that vorticity maximum will continue driving southeast
through northern MO and then into KY. This is expected to drag that
deformation forced light snow southeast out of the area by 9 am or
so, leaving the area under general mid-level cyclonic flow with very
weak high pressure at the surface. Soundings and lower level model
relative humidity field indicate the area will be under mostly
cloudy conditions with highs today in the middle 30s to the lower

A weak cold front pushes through the area this evening/overnight
with a cooling damp lower boundary layer. This will drag lower
clouds through the area. Was thinking of the possibility of some
drizzle but soundings indicate that subsidence through the cloud
layer should prevent the drizzle. Shouldn`t see much in the way of
fog either with gradient winds keeping the lower boundary layer
stirred enough. Otherwise, plan on lows dropping into the 20s.

.LONG TERM...(Monday through Saturday)
Issued at 302 AM CST Sun Mar 11 2018

Northerly flow and shortwave troughs passing through look to make
Monday and Tuesday brisk cool days. Have added some flurries in
central WI Monday night to target one of the more vigorous
shortwaves shifting through. Lapse rates steepen through 2.5 km
and there is a bit of CAPE under the cap which could manifest some
snow showers. Most of the models are dry. Will have to watch that
trend for more SW- activity. This wave quickly moves through and
by Tuesday morning the air mass stabilizes. 15-25 mph winds on
Monday will make it feel like the 20s.

Wednesday through Saturday...
Ridge builds in earnest Wednesday and begins the warm-up into 50s.
There are differences in the end of week details as the longwave
trough evolves over the West. The longwave trough has evolved a
bit more off the coast in the recent model runs, with differences
in the shortwave trough energy ejecting out through the region
Fri/Sat. For now it is just small rain/snow chances as the timing is
difficult. Overall, a more active pattern again late week.


.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 634 AM CDT Sun Mar 11 2018

Northwest flow aloft will bring ample cloud cover across the Upper
Mississippi River Region including KRST/KLSE through the period.
VFR conditions early on this morning but expected to deteriorate
into MVFR/IFR later this morning at KRST and into MVFR at KLSE
later this afternoon. High pressure is then expected to clear out
KRST after 10z with KLSE remaining MVFR through 12z.




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