Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Salt Lake City Utah
1119 am MST Monday Mar 2 2015
Synopsis...an upper level trough will linger over the Great
Basin today through tonight then shift east late Tuesday. A
drying and warming trend will follow for the remainder of the
Discussion...morning satellite imagery and objective analysis
depict an upper trough encompassing the Pacific coast/Great Basin
region...with a subtropical moisture tap extending into the Desert
Southwest. A couple of well defined shortwave features rotating
through this larger scale trough...one lifting through the lower
Colorado River valley at this time...and a second dropping down the
northern California coastline. Meanwhile a northern stream shortwave
trough is digging through the Canadian rockies...and will impact
the forecast area Tuesday.
Heavy snow continues across southern Utah in response to the
approaching Colorado River valley wave...and will persist into the
afternoon before gradually tapering off by evening. Earlier
upgraded south central Utah to a Winter Storm Warning where heavy
snowfall has occurred along the northern half of the zone.
As the Colorado River wave lifts northeast this afternoon through this
evening...expect precipitation to become enhanced across northern
Utah/southwest Wyoming as well...and have expanded the going Winter Weather
Advisory into the northern Wasatch Range and southwest Wyoming.
May see a lull across the area overnight in the wake of the Colorado
River wave...before the Canadian rockies shortwave digs south
through the area Tuesday. The associated cold front will sweep
through northern Utah during the morning hours Tuesday...then shift
south into central and southern Utah during the afternoon. Snow
levels should remain on the valley floors across
northern...central and southwest Utah with the passage of this
front...and valley accumulations are expected during the morning
commute. Will address messaging for this system with the
afternoon package after collaborating with partners.
Aviation...light southeasterly winds at the slc terminal as of
18z will switch to the northwest and become stronger through the
next few hours. Ceilings below 7000ft will persist at the terminal
through much of the taf period. Periods of MVFR conditions are
possible through the daytime hours under passing rain
showers...and MVFR will become more prevalent as showers increase
between 22z and 01z...potentially switching to IFR snow after 01z.
Snow accumulation on untreated surfaces between trace and one inch
is expected between 01z and 05z.
Utah...Winter Storm Warning until 9 PM MST this evening for utz020.
Winter Weather Advisory until 4 PM MST Tuesday for utz007>010-
Winter Storm Warning until 4 PM MST Tuesday for utz518.
Winter Weather Advisory until 9 PM MST this evening for utz012-
Wyoming...Winter Weather Advisory until 4 PM MST Tuesday for wyz021.
For more information from National oceanic and atmospheric administration/S National Weather Service visit...
http://weather.Gov/saltlakecity (all lower case)
For frequently asked questions about the area forecast discussion
http://weather.Gov/saltlakecity/general/afd_faqs.Php (all lower case)