Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 212330
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
630 PM CDT SAT MAY 21 2016

.SHORT TERM...(This evening through Sunday)
Issued at 350 PM CDT Sat May 21 2016

At 3 PM, a 1020 MB surface high, located over eastern Wisconsin,
was producing mostly to party sunny skies across the Upper
Mississippi River Valley. Temperatures ranged from the mid-70s to
lower 80s. With dew points in the 30s, the relative humidity
values ranged from 15 to 30 percent.

With the loss of diurnal heating late this afternoon and early
evening, the scattered to broken clouds will rapidly dissipate.
This will leave much of the night clear. With temperatures ranging
from the upper 40s to upper 50s at midnight, it looks like it will
a pleasant night to view a triangle consisting of the full moon,
Saturn, and Mars in southern sky. During the remainder of night,
the combination of dry dew points and light winds will allow
temperatures to fall into the mid and upper 30s in central
Wisconsin, and into the 40s and lower 50s elsewhere. With the
temperatures this cool in central Wisconsin, could not rule a few
areas in central Wisconsin getting some light frost late tonight.

On Sunday, high pressure will continue to provide mainly sunny
skies. There will be a few scattered clouds once the convective
temperature (upper 70s) is reached. High temperatures will top out
in the lower and mid 80s. Like the past 5 days, soundings continue
to show very dry air aloft. With diurnal mixing, the dew points
will once again fall into the lower and mid-30s. This is 5 to 10F
below both the GFS and NAM MOS.

.LONG TERM...(Sunday night through Saturday)
Issued at 350 PM CDT Sat May 21 2016

With much of the synoptic forcing remaining west of the region on
Sunday night and Monday, precipitation chances were either removed
or lowered.

Like much of the past week, we will still be dealing
with dry air being advected into the region on Monday. This will
be especially the case in Wisconsin. Due to this, the dew points
were lowered into the lower and mid-50s in western Wisconsin and
mid- to upper 50s in southeast Minnesota and northeast Iowa on
Monday afternoon. This will lower the CAPES from 1000 to 2500 J/KG
to less than 1000 J/KG. With the surface front washing out before
it even moves into our area, the 0-3 km and 0-6 km shear remain
less than 25 knots. As a result, not anticipating any severe
weather.

From Monday night into Tuesday morning, a short wave trough moves
northwest across northern and western Minnesota. This will keep
the best synoptic forcing and 850 mb moisture transport north and
northwest of the Upper Mississippi River. As a result, still
concerned that the showers and thunderstorm coverage along the
long wave trough may be too high. With 0-1 km mixed layer CAPES
mainly less than 750 J/KG, and 0-3 km and 0-6 km shear less than
20 knots, not anticipating any severe storms.

For the remainder of the time period, the models continue to show
very little run to run consistencies on systems. As a result, just
left the model blends alone. However with said, there is concern
that the precipitation chances are too high in many of these time
periods.

&&

.AVIATION...(For the 00Z TAFS through 00Z Sunday evening)
Issued at 630 PM CDT Sat May 21 2016

A very dry air mass will result in clear/sunny skies at KRST/KLSE
through the period as surface high pressure continues to dominate
the regional weather pattern. Light and variable wind through
Sunday morning will increase slightly from the south by the
afternoon hours.

&&

.ARX Watches/Warnings/Advisories...
WI...None.
MN...None.
IA...None.
&&

$$

SHORT TERM...BOYNE
LONG TERM...BOYNE
AVIATION...ROGERS



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