Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 300248
AFDARX

Area Forecast Discussion
National Weather Service La Crosse WI
948 PM CDT Thu Sep 29 2016

.SHORT TERM...(This evening through Friday)
Issued at 242 PM CDT Thu Sep 29 2016

Latest water vapor satellite imagery indicates closed upper level
low over the Ohio River Valley and upper level ridge over Northern
and High Plains. Latest 19z surface analysis shows dry
northeasterly flow over much of Wisconsin and eastern Minnesota
and is producing mostly sunny skies across the forecast area per
latest visible satellite imagery.

Tonight into Friday...The 29.12z GFS/NAM are in decent agreement in
lifting upper level closed low northward and wraps low level
moisture into the eastern areas of the forecast area after 06z
Friday. The deterministic models indicate increasing lift/moisture
in association with the first impulse wrapping around the upper
level closed low and to impact the eastern to southeast parts of
the forecast area after 18z Friday. Scattered showers are
expected across this part of the forecast area Friday afternoon.
Have kept chance of showers over the eastern and southeast parts
of the forecast area.

.LONG TERM...(Friday night through Thursday)
Issued at 242 PM CDT Thu Sep 29 2016

Scattered shower chances increase mainly east of the forecast
area Friday night into Saturday...as the upper level closed low
wraps a series of shortwaves into the forecast area. The 29.12z
GFS/NAM/ECMWF show slight differences in how far west
precipitation/moisture will be Friday night into Saturday...as
models differ on placement of the upper level closed low.
However...there is a good chance of showers east of the
Mississippi River late Friday night into Saturday morning.

Upper level closed low moves into the eastern Great Lakes Region
and upper level/surface ridge builds into the Upper Midwest
Saturday night into Sunday. Clouds are expected to diminish
across the forecast area and dry weather will prevail.

Main forecast concerns are precipitation chances Tuesday night
through Thursday. The 29.12z GFS/ECMWF/GEM are in good agreement in
building upper level ridge into the Upper Midwest and Great Lakes
Region through 00z Wednesday. However...significant differences
occur between the deterministic models with the strength of the
upper level ridge Monday into Tuesday and the upper level
trough/closed low ejecting out into the central United States
Wednesday into Thursday. This will have impacts on timing of
shower/thunderstorm chances Tuesday night into Thursday. The
forecast area will remain dry Sunday night through Tuesday.
Then... shower/thunderstorm chances increase Tuesday night through
Thursday with increasing moisture and forcing/lift across the
forecast area. Temperatures through the forecast period will be
slightly above normal...as the 29.12z GFS/ECMWF/GEM show decent
warm air advection under upper level ridge.

&&

.AVIATION...(For the 00Z TAFS through 00Z Friday evening)
Issued at 948 PM CDT Thu Sep 29 2016

Skies are clear and will remain that way through sunrise, save for
perhaps a little bit of light fog development around RST. As
mentioned earlier, winds aloft just look too strong to promote any
fog for the LSE terminal. Lower clouds to our east will slowly
migrate westward with time on Friday, with ceilings eventually
ending up MVFR for both LSE and RST but with some chance the
lowest ceilings may rotate southward out of the area by evening.
Winds will be from the northeast 5-15 knots the next 24 hours.

&&

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

$$

SHORT TERM...DTJ
LONG TERM...DTJ
AVIATION...Lawrence


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