Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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FXUS65 KSLC 210430
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
930 PM MST Mon Nov 20 2017

.SYNOPSIS...A weather system will brush by northern Utah and
southwest Wyoming through tonight. Strong high pressure aloft will
follow for the middle and latter portions of the week.

&&

.DISCUSSION...High pressure continues to build upstream of Utah
while a weak shortwave trough continues to track southeast along the
northern Rockies. Warm air advection is currently occurring at 700mb
over northern Utah and its strength should be at its peak through
around midnight. Deep moisture remains in place north of Utah, and
while the airmass continues to gradually moisten downward over
northern Utah, there remains enough of a dry layer to prevent much
in the way of precipitation from developing. As a result, have
trimmed PoPs south of the area near the Idaho border for the rest of
the evening. With continued moistening, a better chance for
precipitation may be possible closer to midnight, but by then the
dynamic support will be waning. Have spread precipitation farther
south in the forecast after midnight to account for the moistening
and due to various models trending that way. However, have kept the
PoPs on the low side.

With the shortwave disturbance diving south across Wyoming later
tonight, winds are expected to increase across the higher peaks and
exposed areas of the northern Wasatch mountains and across southwest
Wyoming. Have bumped winds up a bit in those areas for the rest of
the night.

High pressure will settle into the area tomorrow and through much of
the week. This will result in a dry and stable airmass and very warm
temperatures for this time of year.

&&

.AVIATION...The SLC terminal will see VFR conditions through the
night with mostly cloudy skies. There is a 20 percent chance of cigs
briefly dropping to or below 6000 feet AGL through 07-08z with
precipitation in the vicinity of the terminal. Southerly winds are
expected to prevail through the night.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

$$

Cheng

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visit...
http://weather.gov/saltlakecity/general/afd_faqs.php



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