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Area forecast discussion
National Weather Service La Crosse WI
1145 am CDT Wed Oct 16 2019

Short term...(today and tonight)
issued at 317 am CDT Wed Oct 16 2019

At 3 am, cyclonic flow, associated with the closed low pressure
area over lower Michigan, kept skies mainly cloudy across the
upper Mississippi River valley. In addition, there were scattered
rain showers across central Wisconsin. The rain will be moving
east of the area this morning as the upper level low moves east
into Lake Huron. While the low will be exiting the area, moisture
will remain trapped underneath the subsidence inversion. As a
result, we will remain mainly cloudy until the 950 to 850 mb
ridge moves east of the area. This will not occur until tonight.
High temperatures will be mainly in the 40s today. Lows on
Thursday morning will be in the lower to mid-30s.

Long term...(thursday through tuesday)
issued at 317 am CDT Wed Oct 16 2019

On Friday, the combination of a tight surface gradient and
sunshine will allow mixing to occur. The main question is the
depth of this mixing. The NAM would suggest up to 900 mb.
Meanwhile, the GFS soundings are showing that it will be up to
800 mb. For now, opted to mix up to 900 mb which would generate
high temperatures in the 60s. This is about 5f warmer than MOS
guidance. If we happened to mix even deeper, these temperatures
may be too conservative and we could over perform.

From Friday night into Saturday, the models are currently
indicating that the Pacific cold front will move to the east much
faster. This could potentially result in much of Saturday
remaining dry. Due to this, started lowering the rain chances east
of the Mississippi River and removed them across the remainder of
the area on Saturday afternoon.

From Sunday night into Monday, a stronger shortwave trough will
move through the region. Unlike yesterday, the models are in much
better agreement that the upper level low will move northeast
across northwest Minnesota. In addition, they are better in
agreement that the best moisture transport will be well east of
the area, thus, the rainfall amounts (maybe up to a half inch)
look less for the area. With 0-1 km convective available potential energy up to 500 j/kg, kept the
mention of scattered thunderstorms in the forecast for Sunday
night and Monday morning.


Aviation...(for the 18z tafs through 18z Thursday afternoon)
issued at 1145 am CDT Wed Oct 16 2019

Cigs: cyclonic flow a loft is keeping the area under a blanket of
MVFR/VFR low clouds for the afternoon. Some holes in the cloud
shield per latest satellite imagery, but these fill in due to
daytime heating. Model trends support gradually improvement toward
evening, with a clearing/scattering of the deck overnight-Thu
morning. Should see mostly sky clear conditions Thu as an area of high
pressure builds into the area.

Wx/vsby: no impacts expected.

Winds: pressure gradient is starting to relax as low pressure system
moves east, and wind speeds/gusts are decreasing as a result. Mostly
light southeast/vrb by the evening.


Arx watches/warnings/advisories...


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