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Area forecast discussion
National Weather Service La Crosse WI
541 am CDT sun Aug 18 2019

Short term...(today through monday)
issued at 150 am CDT sun Aug 18 2019

Watching line of storms move through the area as overnight moisture
transport peaks. Mature quasi-linear convective system has generally
produced sub severe wind gusts so far and with slightly lower Theta-
E air ahead of it, with marginal shear, would expect a steady state
progression or even weakening per Storm Prediction Center thoughts. Seeing some wake low
winds behind line too but nothing too bad at this point.

Forward progress of system should limit any flood potential,
especially as more east-west convection, where flow becomes more
parallel to shear, is shifting closer to I-80.

Line should continue to exit the area this morning with gradually
drying and clearing trends expected into Sunday evening.

As surface ridge builds in quickly overnight /Monday morning/, could
see some valley fog develop. Confidence is only medium on this given
drier northwest winds for a time later today. All will depend on how
quickly ridge builds in. Either way, Monday is looking like a
gorgeous late Summer day.

Long term...(monday night through saturday)
issued at 150 am CDT sun Aug 18 2019

Will be watching next upstream shortwave trough and associated cold
front approach region on Tuesday. Medium range guidance suggesting
quite the mixed layer cape pool /2000-3500 j/kg/ just to the
southwest and south of US so will have to monitoring progress of
this system as it gets closer. Mid layer winds could be quite strong
too as wave moves across upper Midwest so could see part of area be

Passage of that system promises return to drier northwest flow and
quiet stretch of weather likely going into the weekend. Could see
temperatures run below normal for several days.


Aviation...(for the 12z tafs through 12z Monday morning)
issued at 541 am CDT sun Aug 18 2019

Initially a messy aviation forecast with variety of flight rules
around the region in wake of convective system overnight. Mix of IFR
and MVFR ceilings being observed, which could plague flights for
this morning. Eventually northwest flow becomes widespread and will
lead to return of VFR conditions and clearing skies later in the day.

Clearing trend, along with surface ridge building in quickly
tonight, could lead to some valley fog development. Confidence a bit
in question given a bit drier northwest flow expected today.


Arx watches/warnings/advisories...


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