Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 181126
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
626 AM CDT Sun Jun 18 2017

.SHORT TERM...(Today through Tuesday Night)
Issued at 215 AM CDT Sun Jun 18 2017

High Impact Weather Potential: Not much. Isolated thunderstorms
expected this afternoon and again Monday afternoon. No severe
weather risk.

Ready for a temporary respite from the recent jump start into hot
summer weather? We`re here to deliver, with upper troughing
taking up residence over the region into early next week. Already
seeing the pattern change underway early this morning, with a
rather robust shortwave traversing the area, helping drive a
smattering of showers and isolated storms earlier, many of which
have since dissipated with waning forcing. That upper wave will
quickly shift into the northern Great Lakes this afternoon, with
additional energy working southeast out of Alberta interacting
with building heights over the western CONUS to further amplify
upper troughing over much of the Upper Midwest and Great Lakes
into early next week. Within broad northwest flow, a few
additional shortwaves are expected to drop through the area,
interacting with diurnal influences to deliver diurnally- enhanced
shower chances beneath a building cool pool aloft.

Exact placement of showers for any one given period remains lower
confidence, though much of the activity should be confined mainly to
the 15-01Z time frame each day. Somewhat steeper low/mid level lapse
rates this afternoon and again Monday afternoon will also contribute
to roughly 500-750 J/kg MLCAPE during peak heating, suggesting an
isolated thunder threat is likely, especially considering the time
of year and cool air aloft. As advertised, temperatures will really
take a notable tumble, with highs only in the 60s and lower 70s
today slowly trending back through the lower half of the 70s by
Tuesday, though somewhat dictated by cloud and/or precip trends at
any given location each day.

.LONG TERM...(Wednesday through Saturday)
Issued at 215 AM CDT Sun Jun 18 2017

Looking more and more like a brief period of much warmer and
potentially stormy conditions will return toward later Wednesday and
Thursday as our flow aloft flattens out and return flow gets
underway, but with a return to cooler conditions toward next weekend
with another bout of upper troughing in place. While the details
remains still somewhat murky, the overall trend for returning
moisture and warmth Wednesday and Thursday with a warm front
somewhere nearby remains this forecast cycle, though with plenty of
questions regarding available instability as clouds may be prevalent
along that front. Regardless, some risk for stronger storms may
exist with increasing deep layer shear later Wednesday and/or
Thursday, before we again start to scour better low level moisture
by Friday and especially into the weekend with a return to a
northwest flow regime. Temperatures Wednesday/Thursday highly in
question based on cloud/precip trends, but confidence remains on the
higher side for a return to below normal readings into next weekend.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 626 AM CDT Sun Jun 18 2017

A broken MVFR/low VFR cloud shield has been rotating
southeastward into the area behind a low pressure system this
morning. Expect ceilings to gradually rise into the VFR range
this morning with additional diurnally driven VFR cloud
development as well. Isolated showers/storms are possible,
especially this afternoon, but with coverage likely to be low,
will not mention at this time. Northwest winds will gust in the
20-25 kt range at times today before subsiding this evening.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...None.
MN...None.
IA...None.
&&

$$

SHORT TERM...Lawrence
LONG TERM...Lawrence
AVIATION...JM



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