Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 230427
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1127 PM CDT Tue Aug 22 2017

.SHORT TERM...(Tonight through Friday)
Issued at 153 PM CDT Tue Aug 22 2017

High Impact Weather Potential: Not much at all. Maybe a few showers
toward Wednesday night and again Friday but with overall very quiet
weather the remainder of the work week.

Doesn`t get much nicer for late August, but then again it seems
we`ve been really spoiled with cool and non-humid conditions for the
past month. In fact, interestingly enough, it`s been exactly one
month since our last severe weather related warning - certainly an
impressive fete for these parts this time of year. Looking at the
upper pattern, it certainly looks familiar, with a return to upper
troughing now well underway across the Great Lakes/Upper Midwest the
past 12-18 hours, with notably drier air spilling southward into the
area in the wake of a departing cold front. Outside of the standard
few to scattered cumulus beneath cooler air aloft today into
Wednesday (maybe a period of thicker stratocumulus east of the
Mississippi River Wednesday afternoon?), just not much to discuss
with some very pleasant conditions in place and really no fog
risk tonight with continued stronger flow in place aloft.

Bigger focus (if you can call it that) is a fairly robust shortwave
progged to drop near or just east of the area Wednesday night.
Overall forcing is fairly decent but moisture is lacking. Given the
strength of forcing, do suspect we will at a minimum see some
sprinkles or light showers from this feature but wouldn`t be shocked
to see a small window of more enhanced showers right ahead of the
wave.

Quiet weather returns Thursday through Friday, though can`t rule out
a few light showers maybe impact far western areas late Thursday
night or Friday morning as weak return flow aloft gets underway.
With that said, the ECMWF has consistently been slower with said
moisture return, and it has had a much better track record with our
recent cooler weather. Could see looking at some fog potential
Thursday night with low level ridging just to our east with
otherwise continued comfortable highs in the 70s and lows in the
40s/50s.

.LONG TERM...(Friday Night through Tuesday)
Issued at 153 PM CDT Tue Aug 22 2017

Broad upper troughing still on track to depart through the weekend,
but with persistent hints of a weaker slow-moving series of weak
shortwaves traversing the area in a more zonal flow regime. During
this stretch, all eyes will also be on the remnants of Tropical
Storm or maybe Hurricane Harvey as it works toward the Texas coast
per current forecast trends. Lots of questions about where those
circulation remnants will stall over Texas or be picked up in the
flow to our east, and that will have some say over how fast a cold
front clears the area. Should the tropical system get picked up and
lift toward the Ohio Valley, that would really tend to slow down the
front`s progression, which could spell an extended period of clouds
and some showers. A consensus forecast this far out spells several
periods of rain chances Saturday into Monday, though we`ll have
to watch trends the next few days. Of much higher certainty is a
real lack of any instability up this way through early next week,
with no thunder in the forecast whatsoever through next Tuesday.
Don`t see that very often this time of year.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1127 PM CDT Tue Aug 22 2017

VFR conditions are expected at the TAF sites through the forecast
period. Cumulus clouds will develop at the TAF sites late in the
morning into the afternoon hours with cloud bases in the 4-5kft
range. The best moisture for the cumulus will be along and east of
the Mississippi River over western into central Wisconsin, where
ceilings will most likely go broken at times at KLSE. A shortwave
trough then moves in from the northwest Wednesday evening into the
overnight hours with light rain possible at both TAF sites,
mainly after 06Z.

&&

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

$$

SHORT TERM...Lawrence
LONG TERM...Lawrence
AVIATION...Wetenkamp


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