Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 181928

Area Forecast Discussion
National Weather Service La Crosse WI
228 PM CDT Wed Apr 18 2018

.SHORT TERM...(This evening through Thursday)
Issued at 228 PM CDT Wed Apr 18 2018

Through the remainder of this afternoon, the frontogenetic
band will remain along the Minnesota and Iowa border east across
southern Wisconsin. This band will gradually weaken during the
early to mid evening. As this occurs, the snow will taper off to
flurries and end. Additional snow amounts will range from 2 to 5
inches this afternoon and from a trace to 1 inch between 7 PM and
10 PM this evening. This will raise the storm snowfall total into
the 6 to 12 inch range in the aforementioned band. There may be a
few higher totals along the Minnesota and Iowa border in Mower
and Fillmore counties in southeast Minnesota and Mitchell and
Howard counties in northeast Iowa.

Due to the heavy snow south along and south of Interstate 90,
lowered the maximum temperatures by 5 to 7F.

.LONG TERM...(Thursday night through Wednesday)
Issued at 228 PM CDT Wed Apr 18 2018

From Thursday night through Monday, high pressure will provide
some much needed dry weather for the region. Snow cover will
initially limit some of the warming on Friday and Saturday, but
by the end of the weekend much of it should be melted and high
temperatures will become more seasonable (lower and mid 60s).

From Monday night into Wednesday, the models move a Canadian cold
front southeast through the region. The timing of this frontal
passage is highly uncertain due to differences in the models. The
GFS moves this front through from Monday night into Tuesday. The
ECMWF moves it through from Tuesday into Wednesday morning.
Meanwhile, the Canadian has an upper level low moving through the
region, so it keeps the precipitation over the area through the
mid week period. This precipitation will be mainly rain. However,
the may be enough cold air in the wake of this front for a brief
period of snow.


.AVIATION...(For the 18Z TAFS through 18Z Thursday afternoon)
Issued at 1239 PM CDT Wed Apr 18 2018

Main taf concerns are IFR conditions potential at RST/LSE taf
sites this afternoon into this evening. Latest mosaic radar
indicates heavy snow band along and south of Interstate 90 with
latest metars reporting LIFR conditions underneath the snow band.
At this time...not expecting LIFR conditions to occur at RST taf
site as heavy snow band is just south of Interstate 90...though if
snow band shifts north slightly IFR conditions will occur at RST
taf site. Have introduced a tempo group with IFR conditions
through 22z today. LSE taf site should remain in MVFR
conditions...with a potential to lower to IFR condition between
20z today to 00z Thursday. Surface ridge builds into Minnesota
and western Wisconsin after 06z Thursday and provide VFR
conditions by 07-08z Thursday at both RST/LSE taf sites.


WI...Winter Storm Warning until 1 AM CDT Thursday for WIZ053>055-061.

     Winter Weather Advisory until 1 AM CDT Thursday for WIZ041>044.

MN...Winter Storm Warning until 1 AM CDT Thursday for MNZ094>096.

     Winter Weather Advisory until 1 AM CDT Thursday for MNZ086>088.

IA...Winter Storm Warning until 1 AM CDT Thursday for IAZ008>011-018-



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