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FXUS63 KARX 190446

Area Forecast Discussion
National Weather Service La Crosse WI
1046 PM CST Mon Nov 18 2019

.SHORT TERM...(This evening through Tuesday)
Issued at 303 PM CST Mon Nov 18 2019

Early afternoon water vapor imagery showed a shortwave moving 
through the Dakotas and into Minnesota, with an associated surface
warm front and precipitation draped from north to south across 
the Dakotas. Behind the front and precip, clear skies and strong 
westerly winds allowed temperatures to climb into the upper 50s 
and lower 60s. The strong warm air advection and shortwave will 
serve as the primary forcing for continued precipitation in our 
forecast area tonight, though models do hint at a little low level
frontogenesis developing. Overall trends in guidance have been 
slower with onset of precipitation in the forecast area, so may 
need to further adjust forecast timing as we go through the 
afternoon, but at this point it looks like it will move into 
western portions of the forecast area a little before midnight. 
While clouds have kept temperatures a bit cooler today, the 
aforementioned strong warm air advection along with the persistent
cloud cover tonight should keep temperatures relatively "warm" 
tonight, with lows in the upper 20s across central Wisconsin to 
the upper 30s in northeast Iowa and southeast Minnesota. 
Therefore, expecting mainly rain west of the Mississippi River, 
and more of a rain/snow mix to the east. The coldest areas 
(generally along I-94) could also see some freezing rain/drizzle 
along with their half inch or so of snow, but not expecting much 
more than a trace of icing. That said, will need to watch surface 
temperatures (and road temperatures) closely tonight. After the 
main band of precip exits the area, model soundings do show a 
pretty good drizzle signal with loss of in cloud ice on Tuesday 
morning. Will need to continue to watch surface temperatures 
through the morning, but with the continued strong westerly winds,
we should warm above freezing relatively quickly.

.LONG TERM...(Tuesday night through Monday)
Issued at 303 PM CST Mon Nov 18 2019

Main concern for the long term will be the system moving in 
Wednesday night/Thursday.  The region will be in southerly return 
flow Wednesday night as surface ridging slides east and low pressure 
races northeast toward the Upper Midwest from the southern plains. 
Plentiful moisture will surge northward with this system, with 
precipitable water approaching 1" across much of the area (2 
standard anomalies above normal for this time of year). Needless to 
say, this system looks wet, with QPF around 0.5 to 0.75". The big 
question will be temperatures over our area as this will determine 
rain/snow potential. Models are in fairly good agreement on taking 
the low through Iowa into southwest Wisconsin Thursday morning, and 
into the Great Lakes by Thursday evening. As it stands now, it looks 
like the area will be under enough warm air to keep most 
precipitation as rain, with perhaps some snow mixing in on the back 
side of the system late Thursday morning as colder air works into 
the area. Better chances of accumulating snow look north and west of 
our area at this time. However, this system will definitely have to 
be watched as we get closer in time.  

High pressure then nudges into the area for Friday into the weekend, 
with drier weather expected. After a brief cool down Friday, the 
weekend looks to rebound to near normal again, with highs near 40 
into early next week. Precipitation chances start to increase again 
by early next week, but at this time there is a lot of model spread 
and thus confidence is low.


.AVIATION...(For the 06Z TAFS through 06Z Tuesday night)
Issued at 1047 PM CST Mon Nov 18 2019

Light precipitation will overspread the area tonight, with
primarily rain expected at RST due to warmer temperatures, but a
period of rain and snow possible at LSE for a few hours. There has
been a brief break in IFR/low end MVFR conditions at both RST and
LSE, though that isn't likely to last too long, with IFR ceilings
developing everywhere later tonight, with some drizzle also possible
once the main area of precipitation departs after 10Z. Slow
improvement back to MVFR conditions should then take place through
midday and beyond on Tuesday, with light winds tonight shifting
westerly 5-10 knots into early afternoon.



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