Area Forecast Discussion
Issued by NWS La Crosse, WI

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FXUS63 KARX 161829

Area Forecast Discussion
National Weather Service La Crosse WI
130 PM CDT Fri Apr 16 2021

.SHORT TERM...(Weekend)
Issued at 130 PM CDT Fri Apr 16 2021

Weak shortwave ridging tonight into Saturday, with the models then
dropping a shortwave trough mostly south/southwest of the local area
Sat night/Sun. Could see a thin ribbon of upper level energy reach
northward of the main trough, but saturation is limited. Could see a
few clouds but not anticipating any pcpn chances as of now.

For temps, looking fairly seasonable with near or a few degrees
below the mid April normals.

.LONG TERM...(Monday through Friday)
Issued at 130 PM CDT Fri Apr 16 2021

The variety of models all remain in good agreement with sliding an
upper level shortwave trough across the upper mississippi river
valley Monday. An associated cold front drives well ahead of the
parent upper level feature, with the bulk of the saturation also
lying to the north/west of the sfc front. The NAM/GFS/EC resulting
qpf lies behind the front, and mostly in a narrow band. Some
suggestions too that the better pcpn chances will lie to the north
(with sfc low/upper level trough) and west (another piece of upper
level energy)...with a weakening/bkn band of light pcpn locally. QPF
is minimal. In addition, good shot of cold air following in the wake
of the front (more on that below) so some snow could mix in with any

Post the cold front, the GFS and EC are in good agreement with
pushing cold, Canadian air southward across the region. 850 mb temps
as cold as -8 C currently progged, with NAEFS 850 mb temp anomalies
at least -1. The result looks to be highs only in the 40s with
freezing temps for lows through Thu morning. Chilly. More March like
than April. Could see some moderation as we near the end of the work
week, although still likely below the seasonable normals.

After the Monday rain chances, pcpn potential gets murkier as the
GFS and EC show a fair amount of differences between how they handle
various shortwave troughs - timing, positioning and strength. There
does look to be some pcpn chances as we get into the weekend, but
confidence low on what periods would harbor the better chances.
Going to ride the model blend for now.


.AVIATION...(For the 18Z TAFS through 18Z Saturday afternoon)
Issued at 1107 AM CDT Fri Apr 16 2021

VFR conditions likely through this TAF period under surface high
pressure with northerly winds generally under 10 kts and periods of
mid/high SCT/BKN clouds.




LONG TERM....Rieck
AVIATION.....JM is the U.S. government's official web portal to all federal, state and local government web resources and services.