Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 260443

Area Forecast Discussion
National Weather Service La Crosse WI
1143 PM CDT Sun Sep 25 2016

.SHORT TERM...(Tonight through Tuesday)
Issued at 210 PM CDT Sun Sep 25 2016

Surface cold front associated with an upper level trough will
continue its march eastward tonight, firing showers and a few
thunderstorms along and ahead of it. Expecting this activity to be
east of the local forecast area.

Later tonight through Tuesday...spirals of upper level energy will
sweep across the Upper Mississippi River valley as the upper level
trough/closed low meanders east/southeast...while the system`s sfc
low is progged to drop into MI Tue afternoon. With ample moisture to
tap into, expect areas of showers to spark off this forcing. Mostly
across the north tonight-Monday, but shifting to eastern parts of
the forecast area Tue as the sfc low slides across eastern WI. Not
expecting much for amounts, so should not have an impact on current
high/flooding river systems or pose a threat for more areal/flash

Back to Monday...tight pressure gradient builds in from the Northern
Plains...with bufkit soundings suggesting mixing up to 800 mb.
Should be a rather windy day. Observations across the Dakotas
indicating peak wind gusts from 35-45 mph this afternoon. A bit more
favorable setup over there today than across this area for Monday,
but gusts in the wind prone/open areas of southeast MN and northeast
IA in the mid 30s to near 40 mph certainly possible.

.LONG TERM...(Wednesday through Sunday)
Issued at 210 PM CDT Sun Sep 25 2016

GFS/ECMWF remain bullish on an extended period of dry weather...
building in an upper level ridge coupled with a high at the sfc.
Definitely needed for the region.

One point of the interest though is the trough that drops toward the
southeast U.S. after Tue. The GFS favors kicking that off the coast
and letting it go on its way. The ECMWF, however, cuts off the
closed low from the mean flow, gradually meandering it back north to
across the eastern Great Lakes for the weekend. This solution would
put Wisconsin back under some rain chances. The GEM on the otherhand
doesn`t take the trough southeast at all, rather pushes it mostly
due east to across the New England states for the weekend.
Going to lean on the drier solution and keep it dry.

As for temps, they look fairly seasonable for the later half of this
week...right around the late September normals.


.AVIATION...(For the 06Z TAFS through 06Z Monday night)
Issued at 1143 PM CDT Sun Sep 25 2016

The back edge of the lower VFR ceilings has worked through both
airports this evening. However, there is another area of mid level
clouds rotating southeast across Minnesota that the 26.03Z RAP
suggests could bring a ceiling back into both airports for a while
overnight. These clouds should clear out before sunrise for a
sunny start to Monday before scattered to broken cumulus form late
in the morning or early in the afternoon. The 26.00Z NAM has
backed off on the amount of moisture available for KRST and no
longer suggests a VFR ceiling will form there Monday afternoon.
The other issue to contend with Monday will be the winds. A pretty
tight pressure gradient will be over the Upper Midwest and with
steep lapse rated developing during the morning this should lead
to gusts of 25 to 30 knots for a good share of the day.




LONG TERM....Rieck
AVIATION...04 is the U.S. government's official web portal to all federal, state and local government web resources and services.