Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 221153
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
553 AM CST Wed Jan 22 2020

.SHORT TERM...(Today through Thursday Night)
Issued at 234 AM CST Wed Jan 22 2020

Vigorous mid-level trough progressing east through the Plains early
this morning per GOES Water Vapor/RAP 500mb analysis. Push of
moisture/warm air advection ahead of this wave was producing a
decent plume of precipitation from KS all the way up through eastern
NE, western and central IA, and southeast MN. Otherwise, clouds were
thickening across our area with temperatures sitting in the upper
teens to mid 20s. In addition, fairly strong pressure gradient
between departing high and incoming trough of low pressure was
producing gusty south winds with gusts in the 25-35kt range across
the open areas of southeast MN / northeast IA.

For today, that mid-level trough continues edging eastward with
plume of precipitation pushing into portions of northeast
IA/southeast MN and western WI. Will probably see a several hour
window from 3 am into the early morning commute hours where a wintry
mix of light sleet/freezing rain and snow may all be present per
latest forecast temperature/moisture profiles in the column.
Stronger push of 850mb moisture transport and some transient f-gen
could produce a decent burst of snow for portions of southeast MN
into west central WI -per latest hires models. With this and the
mixed precipitation in mind, will expand current winter weather
advisory headline slightly in coverage and in time through noon.
Past this morning, transition to all light snow is expected through
the day and working eastward with time through the area. Otherwise,
milder today with highs in the 30s.

Looks like a long period of light snow then from today through
Thursday night as that trough ambles slowly eastward through the
region.  Snowfall from today through Thursday looks to be in the 2
to 5 inch range...but again, over a long 2 day duration. Outside of
this morning with the wintry mix, would expect impacts to be minimal
with road treatment and lighter snow rates/warmer daytime highs in
the 30s. Would expect impacts past this morning to be mainly at night as
temperatures cool into the 20s for possible re-freeze on roadways.

.LONG TERM...(Friday through Tuesday)
Issued at 234 AM CST Wed Jan 22 2020

Models showing a closed low Friday over the Ohio River Valley while
inverted surface/mid-level trough hangs over our area. This will
likely keep light snow going through the day. The low then tracks
northeastward toward lower MI Friday night/early Saturday with light
snow continuing to wrap into eastern/central WI. Accumulations look
light with generally and inch or less anticipated. Milder
temperatures continue Friday and Saturday with highs in the 30s and
lows in the mid-upper 20s.

Ridge of high pressure moves overhead for Sunday into Monday for a
quiet/extended mild period. Plan on highs well into the 30s with
lows in the 20s.

A chance of rain and snow moves in for Tuesday in advance of low
pressure moving through the Plains. Continued mild otherwise with
highs in the 35 to 45 degree range.

&&

.AVIATION...(For the 12Z TAFS through 12Z Thursday morning)
Issued at 553 AM CST Wed Jan 22 2020

Freezing rain and wintry mix threat will diminish as precipitation
quickly becomes snow this early morning. Heaviest snowfall is
expected this morning, and lighter accumulations will persist into
the afternoon. Total snowfall accumulations through the period
will range from 1 to 3 inches at the TAF sites. Ceilings will
progressively decline from MVFR to IFR through the period. Over
this prolonged period of snow chances, visibilities will fluctuate
with tempo IFR conditions possible within the heavier snow bands.
Gusty southerly winds from 20 to 25 knots today will weaken this
evening.

&&

.ARX WATCHES/WARNINGS/ADVISORIES...
WI...Winter Weather Advisory until noon CST today for WIZ032-033.

MN...Winter Weather Advisory until noon CST today for MNZ079-086>088-
     094-095.

IA...Winter Weather Advisory until noon CST today for IAZ008-009-018-
     019.

&&

$$

SHORT TERM...DAS
LONG TERM...DAS
AVIATION...Peters


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