Area Forecast Discussion
Issued by NWS La Crosse, WI

Home | Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary Off
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42

FXUS63 KARX 161743

Area Forecast Discussion
National Weather Service La Crosse WI
1243 PM CDT Fri Mar 16 2018

.SHORT TERM...(Today through Sunday)
ISSUED AT 230 AM CDT Fri Mar 16 2018

NAM/GFS/EC remain in good agreement with spinning an upper level
shortwave trough east across the southern/central plains to over the
mid mississippi river valley by 06z Sat. Some low level
thermodynamics via isentropic upglide/warm air advection leads the
shortwave across IA today/this evening, with some weak west-east
orientated frontogenetic banding well north of the system`s sfc low,
into parts of northern IA. Some 850 mb moisture transport to feed
this system, pushing north/northwest of the sfc low. North-south
running x-sections point to a sharp northward cutoff to the
saturation, as does the RH fields - mostly south of the IA/MN
border. In addition, lower dew points pushing in from the
east/northeast - helping to try and set a hard edge to any northern
push of pcpn chances. All in all, decent setup with lift/saturation
for pcpn chances across the south.

As for type, some warm air a loft/ice in cloud concerns. Bufkit
soundings highlight the increase in warming just off the surface,
suggestion full/partial melting possible. Depending on surface temps
this brings a freezing rain threat. Later into the evening,
soundings then point to some potential loss of ice - again,
suggesting a freezing rain/drizzle threat. Overall, think mostly
rain or snow for the main pcpn type, resulting in minor snow
accumulations, mostly on grassy surfaces. Enough signals though that
a light glaze could also result from freezing rain. Don`t think an
advisory is warranted at this time with minimal snow/ice amounts
anticipated, but will monitor.

Rest of the weekend looks quiet and mild with highs inching to
around 50 for some locations.

.LONG TERM...(Monday through Thursday)
ISSUED AT 230 AM CDT Fri Mar 16 2018

GFS and EC continue to trend toward "drier" for the local area
Monday. An upper level shortwave still shifting southeast across the
region, but more of its associated energy spins to the south. Plus,
an east/northeast sfc/near sfc flow promises drier air, especially
across Wisconsin. The upshot continues to be more of a shift south
and/or weakening/dissipating trend on pcpn for the local area. Will
let consensus solution continue to detail chances for now. Overall,
this scenario would hold off the next best chance for pcpn
(after tonight in the south) until next weekend.

After a mild weekend, the models point to an influx of cooler air
from the north for the first half of the new work week. Temperatures
around the seasonable normals (possibly below) should result. Milder
air on tap to return for the weekend.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1244 PM CDT Fri Mar 16 2018

A low pressure system will spread VFR clouds over the TAF sites
through tonight. Otherwise, do not expect any impacts from this
system as precipitation and lower clouds remain well to the south.
Easterly winds around 10 kt could be a bit gusty this afternoon,
mainly at KRST. Look for winds to diminish this evening, becoming
northeasterly around 5 kt by sunrise Saturday.




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