Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 210828

Area Forecast Discussion
National Weather Service La Crosse WI
328 AM CDT Fri Apr 21 2017

.SHORT TERM...(Today and tonight)
Issued at 328 AM CDT Fri Apr 21 2017

Main forecast concerns in the short term are on cloud trends today
then focus turns to low temperatures tonight with the potential
for areas of frost.

Low pressure centered over norther Lake Huron will continue to push
east of the region as high pressure builds in from the northern
plains. Plan on  a few clouds across the region to start the day but
we should then see a gradual decrease. It will be seasonably
warmer across the region today versus Thursday. Plan on highs
climbing into the upper 50s to lower 60s. Clear skies will lead to
good radiational cooling tonight and the potential for some areas
of frost. Locations across central Wisconsin cranberry country
will likely fall into the mid 20s..

.LONG TERM...(Saturday through Thursday)
Issued at 328 AM CDT Fri Apr 21 2017

High pressure will remain in control across the region on Saturday
providing dry and quiet weather. A dry airmass and deep mixing will
result in a drop in afternoon relative humidity values. Forecast
soundings suggest we will mix to around 875 mb.  With this in mind,
have decreased dew points across much of the area Saturday afternoon
and increased highs slightly in valley locations. Afternoon relative
humidity values are expected to fall into the mid 20s to lower 30s
across much of the region. Locations across central Wisconsin will
see relative humidity values fall to around 20 percent. The good
news is that winds will be light out of the northeast initially then
switching to the west.  A weak shortwave and front slide into
northern Minnesota and Upper Michigan from Canada Saturday night
into early Sunday.  This feature will stay well north of the local

A trough then moves across the western CONUS on Sunday with a warm
front setting up across northeast South Dakota and central Minnesota
into central Wisconsin. Low pressure will deepen across South
Dakota and northern Nebraska Monday with an increasing pressure
gradient over the Upper Mississippi River Valley. Breezy to windy
conditions are expected across the area on Monday. Plan on south
winds of 15 to 25 mph with gusts up to 35 mph possible. The low
then lifts northeast towards Lake Superior and pulls a cold front
across the area. Showers are possible along the front. However,
most of the operational forecast models are keeping the bulk of
any rainfall north of Interstate 90 and possibly northwest of the
forecast area. Forecast confidence is rather low that we will see
much precipitation from this system. Another shortwave moves
across Iowa/northern Illinois Tuesday into Wednesday and could
bring additional chances for rain showers to the region. Forecast
confidence then really tapers off going through the end of the
work week. At this time, the Thursday through Saturday timeframe
looks active with several rounds of rainfall possible. It`s a
little too early to nail down details. Temperatures could be cold
enough for some snow to mix in across northern Wisconsin Tuesday
night and again Wednesday night.


.AVIATION...(For the 06Z TAFS through 06Z Friday night)
Issued at 1158 PM CDT Thu Apr 20 2017

Well, so much for the clouds sticking around through the night in
the cyclonic flow. A break in the clouds developed over Minnesota
as subsidence behind the upper level system spread over the
region. With the subsidence, the clouds have continued to
dissipate and are not confined to areas east of both airports.
With the subsidence aloft and high pressure building in from the
northwest in the low levels, not anticipating the clouds coming
back and will stay with VFR conditions through the entire period.


.HYDROLOGY...Through Monday
Issued at 328 AM CDT Fri Apr 21 2017

One to locally three inches of rainfall earlier this week,
combined with very wet soils across the region, has created rises
on area rivers and streams, including minor flooding along
portions of the Black, Trempealeau, and Yellow River in Wisconsin.

The Black River at Black River Falls appears to have
crested and will continue to fall today. The Black River at
Galesville will continue to rise and reach flood stage Saturday
morning. The Trempealeau River at Dodge will continue to rise,
reaching flood stage later today. The Yellow River at Necedah is
expected to rise above flood stage late Saturday afternoon into
Saturday evening. Remain alert for rising water and minor flooding
if you live near or have interests along these rivers.




SHORT TERM...Wetenkamp
LONG TERM...Wetenkamp
HYDROLOGY...Wetenkamp is the U.S. government's official web portal to all federal, state and local government web resources and services.