Winter Storm and Damaging Wind in Utah, February 21 to 24, 2017

Area Forecast Discussion
National Weather Service Salt Lake City UT
939 PM MST Mon Feb 20 2017

.SYNOPSIS...A weak weather system will brush northern Utah
tonight, otherwise a mild and strong southwest flow will prevail
through Tuesday. A cold front Tuesday night will usher in a period
of cold unsettled weather through the end of the week.

&&

.DISCUSSION...A mild and moist southwest flow remains in place over
the forecast area this evening ahead of a trough over the West
Coast. The pressure gradient continues to tighten across Utah while
700mb winds of 45-55kt are forecast overnight. Gusty south winds
have already been realized across the western valleys of Utah and
expect these to continue and even strengthen in some areas tonight
into tomorrow.

Warm advection occurring at 700mb is helping to keep some
precipitation in place across northern Utah, which is being enhanced
by weak ripples making their way through southeast Idaho.
Precipitation is expected to decrease somewhat as the pattern
amplifies, taking these waves farther north. With the airmass
warming, snow levels will mostly remain above 7500ft. Otherwise,
cloud cover across northern Utah along with some low stratus across
southern Utah will combine with the winds and mild airmass to keep
overnight mins on the warm side tonight.

A shift to a much cooler pattern will begin tomorrow night as the
trough over the West Coast pushes a cold front into northern Utah.
This cold front will slowly cross Utah through Wednesday night with
a potential for snow to the valley floors through Thursday.

No updates this evening.

&&

.AVIATION...Gusty south winds will continue at the SLC terminal
through the overnight hours and into Tuesday. Any precipitation
will likely hold off until Tuesday evening.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Wind Advisory until 9 PM MST Tuesday for UTZ003-005-015-016.

     Winter Weather Advisory from 2 PM Tuesday to 11 AM MST Wednesday
     for UTZ007>009.

WY...None.
&&

Cheng

For more information from NOAA's National Weather Service visit...
http://weather.gov/saltlakecity

For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.php

Hazardous Weather Outlook
National Weather Service Salt Lake City UT
523 PM MST Mon Feb 20 2017

UTZ001>016-019>021-517-518-WYZ021-211300-
Cache Valley/Utah Portion-Northern Wasatch Front-
Salt Lake and Tooele Valleys-Southern Wasatch Front-
Great Salt Lake Desert and Mountains-Wasatch Mountain Valleys-
Wasatch Mountains I-80 North-Wasatch Mountains South of I-80-
Western Uinta Mountains-Wasatch Plateau/Book Cliffs-
Western Uinta Basin-Castle Country-San Rafael Swell-
Sanpete/Sevier Valleys-West Central Utah-Southwest Utah-
Utahs Dixie and Zion National Park-South Central Utah-
Glen Canyon Recreation Area/Lake Powell-Central Mountains-
Southern Mountains-Southwest Wyoming-
523 PM MST Mon Feb 20 2017

This Hazardous Weather Outlook is for the western two thirds of
Utah and southwest Wyoming.

.DAY ONE...Tonight

Valley rain and mountain snow will continue across mainly the
northern outlook area through tonight. Only minor snow
accumulation is expected above about 8000 feet.

Local flooding from snow melt will persist across the far
northern portions of the outlook area in valleys with remaining
snow pack.

South winds will strengthen this evening across the mountains as
well as the western valleys, with gusts in excess of 50 mph
possible overnight.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

South to southwest winds will remain strong across the mountains
and western valleys through Tuesday afternoon.

Valley rain and mountain snow will become more widespread across
the northern outlook area Tuesday afternoon shifting south
Tuesday night along a cold front. Snow levels will lower to the
valley floors across the north Tuesday night and into the central
valleys Wednesday.

Cold unsettled weather will continue across the outlook area into
the weekend. Significant snow accumulation is expected in the
northern and central mountains with winter driving conditions
across the passes. Accumulating snow in the valleys could bring
travel impacts at times starting on Wednesday.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

For more information from NOAA/s National Weather Service visit...
http://weather.gov/saltlakecity

For information on potential road travel impacts visit...
http://www.udottraffic.utah.gov/roadweatherforecast.aspx