National Weather Service Text Product Display

Area Forecast Discussion
Issued by NWS La Crosse, WI
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FXUS63 KARX 010504
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
1100 PM CST Tue Jan 31 2017

.SHORT TERM...(This evening through Wednesday)
Issued at 215 PM CST Tue Jan 31 2017

Weak short-wave in northwest flow aloft will move across the forecast
area late this afternoon and evening, bringing some scattered
snow showers to western and southwest WI. Near surface layer could
be warm enough to mix with light rain showers at times. Any snow
accumulation will be a dusting up to perhaps an inch at best. For
the rest of tonight, a cold front currently draped along the
Canadian border will drop southward across the Upper Midwest.
Temperatures will fall through the night into Wednesday, so that
tomorrow`s highs will actually occur at midnight tonight.
Temperatures by Wednesday morning will be in the mid teens to mid
20s.

While Wednesday will be notably cooler with breezy northwest wind,
it will be dry in the post frontal air mass with skies opening up
to some sunshine by afternoon. Highs will only top out from the
mid teens across north central WI to the upper 20s across southwest
WI and portions of far northeast IA. However, these values are
actually closer to early February normals.

.LONG TERM...(Wednesday night through Tuesday)
Issued at 215 PM CST Tue Jan 31 2017

Thursday and Friday will be dry and chilly as a strong surface
high moves slowly across the Upper Midwest. Low precipitation
chances Thursday night into Friday morning will stay along the
southern periphery of the high across NE into southern IA, closest
to the deepest moisture. 925 hPa temperatures fall to between -10
and -15 Celsius both days, resulting in daily highs in the teens
to low 20s and nighttime lows in the single digits above/below the
zero mark.

Next best chance for precipitation will be Saturday and Saturday
night as a Pacific wave undercuts the western CONUS ridge and
moves into the Upper Midwest. This will be another quick moving
warm advective snow, similar to what occurred on Monday. Average
liquid QPF around a tenth should keep snow accumulations on the
low end, although it`s still too early to put firm numbers on the
system. Temperatures will slowly moderate through the weekend with
highs by Sunday into the mid 20s to lower 30s.

Will be closely watching what could be a potentially significant
storm system by next Tuesday. 31.12Z model suite shows a large
Pacific trough moving across the CONUS with its surface low
trajectory somewhere across the Upper Midwest. Way too early to
provide any meaningful details given model differences in timing,
track, strength, and thermal/moisture profiles. Stay tuned to
later forecasts over the next week as details become clearer.

&&

.AVIATION...(For the 06Z TAFS through 06Z Wednesday night)
Issued at 1100 PM CST Tue Jan 31 2017

Snow slow to leave as responsible shortwave trough drops southeast
across the region. Trends/meso models suggest the -shsn threat will
sink south of the taf sites by 06z, although RAP hints that a
lingering frontogenetic band could hang up across northeast
IA/southwest WI overnight. Going to trend the snow south for now.

Looks mostly VFR cigs through Wed morning, but some meso modeled RH
fields point to the potential for MVFR for a few hours overnight.
This matches with what some current obs upstream point to - although
not very uniform. Because of that, will keep VFR for now, and update
if needed. High pressure starts to build in from the northwest later
in the day Wed, and should see some clearing skies as a result.

&&

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

$$

SHORT TERM...Rogers
LONG TERM...Rogers
AVIATION...Rieck
National Weather Service Regional Headquarters
