Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 130353
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
853 PM MST Mon Feb 12 2018

.SYNOPSIS...The upper level low pressure system over the western
Great Basin will drift southwest in California by Tuesday.
Widespread precipitation associated with this low will occur
across the southern half of Utah through Tuesday. Another trough
will move in from the Pacific Northwest Wednesday night through
Thursday.

&&

.DISCUSSION...The upper low over southern Nevada late this
afternoon has reorganized over California this evening. This
farther south position has pulled the divergence zone farther
south and skies cleared rather rapidly across northern Utah this
evening. This area of clearing should remain pretty much in place
through the night but some mid level moisture has potential of
wrapping northward Tuesday so only updated the sky grids for the
overnight period.

The 700 to 600mb baroclinic zone was rather stretched out earlier
today but GFS and NAM showed some tightening of this baroclinic
zone to occur between 03Z and 07Z over southwest Utah. Recent
satellite imagery is indicating cooling cloud tops in this area
and radar showing just a slight increase in echoes past 1/2 hr.
The latest GFS shows that baroclinic zone at its tightest at 09Z
vs the 06Z that the 18Z run showed. So there is pretty good
confidence that snow will increase in intensity for a few hours
yet this evening to about 10Z. Upslope flow will aid in snow
accumulations, but duration of the baroclinic zone remaining in
any one area does not look promising so confidence in achieving
some of the big numbers in the WSW is low. Will let mid crew
assess and make any updates if necessary.

Due to warming and drying at 500mb developing across southern Utah
after 12Z Tuesday the trend of precipitation will wain as the
instability diminishes. This is another factor to consider for
Tuesday.

&&

.AVIATION...Light northerly winds will prevail at the SLC terminal
tonight through Tuesday. VFR conditions will prevail as well.


&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Winter Weather Advisory until 4 PM MST Tuesday for UTZ517-518.

WY...None.
&&

$$

PUBLIC...Struthwolf
AVIATION...Struthwolf

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