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fxus65 kslc 090455 

Area forecast discussion
National Weather Service Salt Lake City Utah
955 PM MST sun Dec 8 2019

Synopsis...a Pacific storm system will exit the region early
Monday. High pressure aloft will return to the region early in the
upcoming week, with another system possible by midweek.


Discussion...the split upper level trough continues to cross the
area this evening, with the mean trough axis nearly bisecting Utah
from southwest to northeast. The surface cold front has moved
through the area, with the back edge of the frontal band across
southeast Utah. Meanwhile, an unstable northwesterly flow aloft
continues to maintain a few showers across the northern mountains
and vicinity.

Temperatures at 500mb will warm slightly after midnight, which may
aid in a slight decrease of shower activity. However, a trailing
shortwave disturbance will then graze southwest Wyoming tomorrow
morning, leading to a slight cooling aloft and the regeneration of a
few showers over/near the mountains. With valleys seeing some mixing
today, the airmass in many valleys still support rain or a rain/snow
mix. As colder air continues to work its way into the area later
tonight, snow levels will fall accordingly, reaching valley floors
across northern Utah. However, showers will be spotty in the valleys
and should produce little or no accumulation. Winter weather
advisories continue in the northern and central mountains through
tomorrow morning to account for higher accumulations due to
favorable orographics in the unstable northwest flow.

A strong ridge will build into the West Coast tomorrow night through
Tuesday. This ridge will bring a stable airmass which will
strengthen valley inversions. A relatively weak trough undercutting
the ridge will cross Utah on Wednesday, producing little or no
precipitation. After that, expect unsettled conditions for at least
northern Utah for the latter half of the week as a strong jet
arrives with a moist airmass in a near zonal flow aloft.


Aviation...VFR conditions are expected to persist at the slc
terminal throughout the taf package, although there is a 20 percent
chance of snow showers late tonight bringing brief reductions of IFR
or low MVFR. Prevailing ceilings below 6kft will likely be maintained
through at least 07-09z, then gradually rise above that late
tonight. Northwest winds should begin to take over by 12z with a 20%
chance of a switch before then, but speeds will likely remain 6kt or


Slc watches/warnings/advisories...
Utah...Winter Weather Advisory until 10 am MST Monday for utz007>010-




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