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Area forecast discussion
National Weather Service La Crosse WI
145 PM CDT Sat Jul 21 2018

Short term...(this evening through sunday)
issued at 145 PM CDT Sat Jul 21 2018

The main forecast concerns are sky cover and chances of
precipitation. Models are in good overall agreement with the
evolution of the pattern but the GFS is an outlier in its western
extent of precipitation today.

The storm system of the last couple of days will continue to lumber
southeastward tonight into Sunday. Sunshine today has lead to the
building of instability with around 500 j/kg of cape and scattered
showers moving westward across the area. Isolated thunderstorms are
possible into this evening with the instability.
Convection will die off with the loss of daytime heating.

Cloud cover is expected to expand westward tonight to along the
Mississippi River helping to keep lows from bottoming out over
night.

Sunday will be similar to today with morning clouds quickly giving
way to sunshine and the re-development of cu and the possiblity of
scattered showers and maybe an isolated thunderstorms.
Temperatures will be similar to today.

Long term...(monday through saturday)
issued at 145 PM CDT Sat Jul 21 2018

GFS and ec are in pretty good agreement with starting to break down
the upper level ridge for the start of the new work week, shifting
toward northwest flow. Shortwaves, bits of upper level energy are
progged to slide across the upper Mississippi River valley for the
new week as a result. The GFS and ec highlight Mon and Wed for
decent shots for showers/storms. Monday would bring a weakening sfc
front across the region, but Wed shows some Promise for potentially
stronger storms. The GFS has some instability and shear at this time,
promoting storm development. Way to far out to have any confidence
in outcomes, but it's a period to keep an eye on.

For temps, fairly seasonable to cool airmass expected for the better
part of the new week, with the models leaning toward the later half
of the week as the coolest (5-10 degrees below normal).

&&

Aviation...(for the 18z tafs through 18z Sunday afternoon)
issued at 1227 PM CDT Sat Jul 21 2018

Western Wisconsin and southeast Minnesota remain under the influence
of a storm system across Indiana and Ohio today. This will lead to
the development of a scattered cloud deck between 3 and 6 kft this
afternoon. Showers may development this afternoon and drift westward
but they are not expected to make it as far west as klse.

Gusty northerly winds up to 20 knots will develop this afternoon and
diminish by sunset this evening. Clouds are forecast to expand
westward overnight with sct ceilings making it to klse by 12 UTC on
Sunday.

&&

Arx watches/warnings/advisories...
WI...none.
Minnesota...none.
Iowa...none.
&&

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