Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 231943

Area Forecast Discussion
National Weather Service La Crosse WI
243 PM CDT Fri Jun 23 2017

.SHORT TERM...(Tonight through Saturday Night)
Issued at 243 PM CDT Fri Jun 23 2017

Water Vapor/Regional Radar Mosaic imagery this afternoon featuring a
mid-level trough and associated scattered shower activity swinging
eastward through MN. Looking for this trough and showers to continue
rotating east into our area later this afternoon into this evening.
Limited instability may eke out an isolated thunderstorm, but overall
expecting scattered showers. Look for this activity to die off later
this evening with sunset/loss of surface heating.

For the rest of tonight, plan on partly cloudy and cool conditions
with lows dipping into the lower/middle 50s.

A rather vigorous mid-level trough/strong 700-300mb pv-advection
will drop through the area for Saturday, bringing with it widespread
shower/scattered thunderstorms by afternoon lasting into the
evening. Given strength of mid-level dynamics/steepening lapse
rates/MUCAPE of 500-1000J/kg, thinking we could see a few stronger
storms capable of sub-severe hail and strong gusty winds. Look for
this convection to simmer down again after sunset with loss of
heating. Partly cloudy and chilly conditions then for the rest of
the overnight with lows falling off into the 45-50 degree range.

.LONG TERM...(Sunday though Friday)
Issued at 243 PM CDT Fri Jun 23 2017

Cool/cyclonic flow continues Sunday through Monday with a couple
embedded weak troughs. As a result, scattered showers and isolated
afternoon thunderstorms expected mainly east of the Mississippi on
Sunday and mainly across central WI on Monday. Otherwise, plan on
cooler than normal temperatures with highs Sunday generally in the
lower/middle 60s and 65 to 70 Monday.

Tuesday looks dry and a bit warmer as a ridge of high pressure
drifts overhead. Still a bit below normal temperature-wise though
with highs in the lower and middle 70s.

Wednesday through Friday looks a bit unsettled with scattered
showers/storms as both the GFS/ECMWF bring a couple low pressure
system across the Plains and through the Upper Mississippi River


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1218 PM CDT Fri Jun 23 2017

The 4K-6K ft stratocu deck is on track to move across the taf sites
this afternoon into early this evening. Deeper diurnal mixing ahead
of it, along with a tighter pressure gradient to result in NW winds
12-18kt G20-25kt thru the afternoon.

Scattered diurnal SHRA and isolated TSRA also still on track to
develop/move across the area this afternoon into early this evening.
These already showing up on radars NW of the area. Did carry a VCSH
at KLSE 20-24z, otherwise given the sct/isolated coverage, left
mention of the SHRA/TSRA out of the tafs for now. NW gradient winds
of 10-12kts expected to persist thru the night, keeping any BR/FG in
the 09-13z time-frame to a minimum.




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