Scientific Forecaster Discussion
Area forecast discussion
National Weather Service Salt Lake City Utah
1005 PM MST sun Mar 1 2015
Synopsis...an upper level trough will linger over the Great
Basin through Monday then shift east late Tuesday. A drying and
warming trend will follow for the remainder of the week.
Discussion...the elongated trough that has been over the western
Continental U.S. The past couple of days is now oriented with its axis
extending from south-central Idaho through central California with a
closed low just off the California coast. With upstream energy
dropping into the area...the pattern has amplified with southerly
flow increasing over Arizona and into southern Utah. This flow has
tapped a plume of moisture that has already entered southern Utah.
The moisture coupled with strong 700 mb convergence and upper diffluence
is leading to widespread precipitation over southern Utah currently.
This area will spread north overnight and into tomorrow along the
leading edge of a 700 mb warm front. With warm advection through the
night...expect snow levels to remain relatively high...at least
across south-central and southeast zones.
Latest observation show precipitation has been falling as snow around Cedar
City...Beaver and price. Lower elevations such as Page have been
reporting rain...and other sites in the 4500-5000ft elevation range
across southern Utah have temperature/dews supportive of rain or at worst a
rain/snow mix. The southwest Utah valleys is expected to remain
mostly snow to the valley floors given the northeast to southwest
orientation of the 700 mb boundary. Snow levels are expected to be near
5500ft from St George to the Kanab area and up through
price...though heavier precipitation could drag snow levels down at
The storm system will finally start to eject east tomorrow...with
the trough axis crossing Utah tomorrow evening. With flow veering to
westerly then northwesterly...precipitation is expected to taper off
over the eastern valleys but continue along The Spine of Utah and
immediately adjacent valleys. Another trough is still prognosticated to
drop in from the northwest on Tuesday...pushing a cold front through
the area that is expected to continue to bring snow to the mountains
as well as the northern and western valleys including the Wasatch
Currently have several zones across southern/central/eastern Utah
with winter weather highlights...which look fine for now. Only
concern is that west-central Utah and the Sanpete/Sevier valleys are
not included but could see significant precipitation. Snow levels
will be the critical variable...but seeing how locations in these
zones such Richfield...Fillmore and Delta all have dewpoints above
freezing...suspect that they would be able to continue fine without
any highlights through the night.
Updated mainly to increase probability of precipitation a bit across northeastern zones.
Aviation...the slc terminal will see VFR conditions throughout this
evening with ceilings staying at or above 7k feet above ground level until 06z. Southeast
winds are expected to prevail after 07-09z. Precipitation is
expected to begin during the morning hours Monday...with a rain/snow
mix the most likely precipitation type for at least the morning
Utah...Winter Weather Advisory until 9 PM MST Monday for utz012-013-016-
Winter Weather Advisory until 4 PM MST Tuesday for utz008-009.
Winter Weather Advisory until 4 PM MST Tuesday for utz010-517.
Winter Storm Warning until 4 PM MST Tuesday for utz518.
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)