Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 221121

Area Forecast Discussion
National Weather Service La Crosse WI
621 AM CDT Sat Oct 22 2016

.SHORT TERM...(Today and tonight)
Issued at 232 AM CDT Sat Oct 22 2016

Warm advective mid-cloud along and east of the MS River early this
morning will push east through the day with mostly sunny skies in
their wake. Forecast area will be in-between systems today with
high pressure to the south and a trough passing to the north,
resulting in light southwest winds. 925 hPa temperatures by 00Z
tonight rise to between +10 and +13 Celsius, resulting in afternoon
highs in the upper 50s to lower 60s. Mostly clear skies tonight
and light southerly winds will allow lows to bottom out in the
upper 30s to lower 40s.

.LONG TERM...(Sunday through Friday)
Issued at 232 AM CDT Sat Oct 22 2016

A cold front will sweep across the region on Sunday. Still appears
the deepest moisture necessary for precip remains just north of
the forecast area, but should see increasing clouds, especially
east of the MS River. Bigger impact will be breezy northwest wind
with roughly 20 to 30 kts to mix to the surface. Expect frequent
gusts from 20 to 30 mph with the strongest values across wind
prone areas of southeast MN and northeast IA. Thermal profile
takes some time to cool behind the front, so early afternoon highs
from the mid 50s to lower 60s are still reasonable.

After a dry, but cooler Monday, rain chances return Tuesday and
Wednesday as a strong eastern Pacific wave undercuts the western
CONUS ridge and moves across the Central Plains. 22.00Z GFS/ECMWF
still in good agreement, showing a lee cyclone develop across
eastern CO and western KS/NE Tuesday afternoon, then lifting
northeast and moving along the I-80 corridor in IA/IL through
Wednesday. Strong east-west oriented 850 to 700 hPa frontogenesis
develops across the forecast area, providing a focus for numerous
showers. With PWATs approaching one inch along a plume of Gulf of
Mexico moisture and very strong lift on the 300 K isentropic
surface, expect periods of moderate to perhaps heavy rain,
especially Tuesday night into Wednesday morning. Too early to
forecast specific rainfall amounts, but the synoptic set-up and
GEFS plumes suggest there is the potential for many areas to see
over an inch over the two-day period. Given overall strength of
the system, will maintain isolated thunder mention along and
south of I-90 even though 0 to 6 km MUCAPE is less than 250 J/kg.

Model consensus is for mostly dry conditions and seasonable
temperatures Thursday and beyond, although forecast confidence is
rather low given large differences in the GFS/ECMWF 500 hPa flow


.AVIATION...(For the 12Z TAFS through 12Z Sunday morning)
Issued at 621 AM CDT Sat Oct 22 2016

Plan on VFR conditions through the period as upper level ridge of
high pressure remains in control across the region. Winds look to
stay under 10kt from a southerly direction.




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