Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 212252

Area Forecast Discussion
National Weather Service La Crosse WI
552 PM CDT Fri Apr 21 2017

.SHORT TERM...(This evening through Saturday)
Issued at 317 PM CDT Fri Apr 21 2017

At 3 PM, high clouds, associated with a short wave trough moving
east northeast out of the Southern Plains, has spread north into
areas along and south of the Interstate 90 corridor. The 21.12z
models continue to show that these clouds will gradually thin
overnight and will likely have little impact on the temperatures
With partly cloudy skies, dry dew points, and light winds,
temperatures will fall into the mid and upper 20s in central
Wisconsin and into the lower and mid 30s elsewhere. Fortunately,
only expecting scattered frost in the areas where the vegetation
is most susceptible to the cold temperatures.

.LONG TERM...(Saturday night through Friday)
Issued at 317 PM CDT Fri Apr 21 2017

On Saturday night, a southerly return flow on the backside of the
high will bring slightly warmer temperatures into the region. Low
temperatures on Sunday morning will be in the lower and mid 30s in
central Wisconsin and range from the mid 30s to lower 40s

On Monday night, a short wave trough will move through the region.
With much of the lift with system remaining across the northern
halves of Minnesota and Wisconsin, rain chances were lowered into
the 20 to 40 percent range. With limited instability, only
expecting showers from this system.

From Tuesday afternoon into Tuesday night, a low pressure system
will move along the frontal boundary laid down by the Monday night
system. With this low pressure area tracking off to our southeast,
only expecting some over running rain from this system.

From Thursday night into Friday, a strengthening low pressure
system will move northeast out of the Southern Plains. Moderate to
strong moisture transport ahead of this system will bring varying
amounts of instability into the region. The ECMWF has CAPES up to
100 J/kg across northeast Iowa and southwest Wisconsin. Meanwhile,
the GFS is a bit further west with its surface low and has most
unstable CAPES of 1-2K J/kg south of Interstate 90. Since both
models had instability across northeast Iowa and southwest
Wisconsin, isolated thunder was added to the forecast.


.AVIATION...(For the 00Z TAFS through 00Z Saturday evening)
Issued at 551 PM CDT Fri Apr 21 2017

High pressure centered over North Dakota and Minnesota will sink
south and be across Iowa and southern Wisconsin by late Saturday
afternoon. Other than the high clouds over the area this evening,
little in the way of cloud cover expected. The winds will become
light as the high moves across and stay that way through Saturday.


.HYDROLOGY...through Monday afternoon
Issued at 317 PM CDT Fri Apr 21 2017

The Black River at Black River Falls is about ready to fall below
flood stage. Meanwhile further downstream, the flood wave is
approaching Galesville. It will rise above flood stage on
Saturday afternoon and remain there through Sunday afternoon. Only
minor flooding is expected.

The Trempealeau River at Dodge is just going above flood stage at
this time and minor flooding is expected through Sunday afternoon.

The Yellow River at Necedah will rise above flood stage on
Saturday evening. Minor flooding is expected through Monday




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