Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 151942
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
242 PM CDT Sun Apr 15 2018

.SHORT TERM...(This evening through Tuesday)
Issued at 242 PM CDT Sun Apr 15 2018

Water vapor satellite this afternoon shows the closed upper level
low was moving slowly south across southern Iowa. The low will
continue to move slowly east through the night, reaching Indiana,
but there will be a short wave trough rotating up and around the
low that will come back over the area. This, combined with the
strong low level cyclonic curvature around the surface low, will
keep some light snow going over most of the area through the
night. Additional accumulations through the night look to be
around an inch or less and at this point, not anticipating any
changes to the winter weather headlines.

High pressure will build in behind this system starting Monday and
will then transition east into the Great Lakes through Tuesday.
The high will not be strong enough to overcome the cyclonic flow
and there could continue to be some lingering light snow across
the eastern sections into Monday afternoon or evening before
moving off to the east. Little to no additional accumulation is
expected with the light snow.

.LONG TERM...(Tuesday night through Sunday)
Issued at 242 PM CDT Sun Apr 15 2018

Attention then quickly changes to the next system that will impact
the area primarily on Wednesday and Wednesday night. This system
is still out over the Pacific so confidence in the overall model
solutions remains relatively low with some differences in timing
shown by the models. The general idea is that the short wave
trough should come onshore either late tonight or Monday morning.
This wave should continue east through the Rockies Tuesday and
quickly become a closed low once it emerges over the Plains
Tuesday night. This system will then work east/northeast into the
lower Great Lakes through Wednesday night. Some differences in
timing and placement of the surface low but this should pass just
to the south of the area Wednesday. Precipitation from this system
should start to move in either late Tuesday night or Wednesday and
then end late Wednesday night. With this being another spring
system, looks like there will again be precipitation type concerns
revolving around how much ice will be in the clouds, a warm nose
aloft that should rotate around the north side of the system and
surface temperatures. With these concerns, currently looking at
having a wintry mix coming in for Tuesday night and Wednesday
morning before going over to primarily rain for Wednesday
afternoon and back to a wintry mix before ending Wednesday night.
With this potential for a wintry mix, could see where more winter
weather headlines could be needed as we get nearer to this system.

&&

.AVIATION...(For the 12Z TAFS through 12Z Monday morning)
Issued at 626 AM CDT Sun Apr 15 2018

Accumulating snow will continue across the taf sites today,(very un
mid-April like) with MVFR/IFR cigs/vsbys in the snow. The snow will
diminish late this afternoon and evening as the responsible sfc thru
mid level finally moves far enough away from the region. Around 4
inches of snow is expected at KLSE thru this evening, with 3 to 4
inches at KRST. Vsbys will improve to VFR after 00-01z. However cigs
are expected to remain MVFR thru tonight as moisture stuck in the
broad lower level cyclonic flow over the Upper Midwest continues to
rotate across the area. Winds will generally remain in the 15-25kt
range today/tonight, gradually swinging from NE to N today then to
NW tonight.

&&

.HYDROLOGY...
Issued at 242 PM CDT Sun Apr 15 2018

Runoff into the rivers has really slowed down with the colder
temperatures. Still dealing with some minor flooding on the
Kickapoo River; see the latest FLSARX (WGUS83) for details.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory until 7 PM CDT this evening for WIZ054-
     055-061.

     Winter Storm Warning until 7 PM CDT this evening for WIZ041>044-
     053.

     Winter Storm Warning until 10 PM CDT this evening for WIZ017-029-
     032>034.

MN...Winter Weather Advisory until 7 PM CDT this evening for MNZ086-
     087-094-095.

     Winter Storm Warning until 7 PM CDT this evening for MNZ088-096.

     Winter Storm Warning until 10 PM CDT this evening for MNZ079.

IA...Winter Weather Advisory until 7 PM CDT this evening for
     IAZ008>011-018-019-029-030.

&&

$$

SHORT TERM...04
LONG TERM...04
AVIATION...Lawrence



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