Area Forecast Discussion
Issued by NWS Salt Lake City, UT
FXUS65 KSLC 162203
Area Forecast Discussion
National Weather Service Salt Lake City UT
403 PM MDT Sun Oct 16 2016
.SYNOPSIS...A Pacific storm system will cross the region tonight
and Monday, with a second storm system set to cross the region
Tuesday and Tuesday night. A ridge of high pressure will build
over the region the latter half of the workweek.
.SHORT TERM (THROUGH 00Z THURSDAY)...
A cold front remains stalled over northern Utah this afternoon
near a KENV-KSLC-KEVW line. Rain with snow at the highest
elevations continues behind this boundary, widespread from the
Utah border to around Ogden, and more scattered in nature down to
about I-80. Overall coverage has diminished a bit since this
morning, primarily in the southern extent of the precip.
Temperatures are noticeably cooler over areas behind the front, up
to 5F below seasonal normals.
Ahead of the front, winds have become fairly strong again, with some
gusts in excess of 40 mph observed over southwest Utah. Flow
continues to increase through the overnight hours with the approach
of the main storm system, particularly over western and southern
Utah, where a wind advisory remains in effect into tomorrow morning.
Have removed the previously included zones over southern and eastern
Utah as current guidance indicates the increase in flow aloft in
those areas would still not support advisory level winds.
The front will remain stalled over northern Utah and southwest
Wyoming through the evening before pushing south overnight with the
arrival of the main Pacific storm system. Dynamics continue to look
impressive with an unusually strong upper level jet. Prior to that
time, precip will continue to be confined to areas along and behind
the front. With the arrival of upper level support and the push of
the front into central Utah, areal coverage of the precipitation
will expand. Guidance shows 700 mb temps dropping to as low as -5C
near the UT/ID border, supporting 6500-7000 foot snow levels.
Accumulating snow will remain above about 8000 feet, limiting travel
impacts. Precipitation is progged to become more showery in nature
and confined to the higher terrain of northern Utah tomorrow
afternoon as the system exits, with a lull in precip tomorrow night.
One last storm system is on track to push through northern Utah and
southwest Wyoming during the day Tuesday, bringing a reinforcing
shot of colder air and some additional precipitation. EC/GFS show
700 mb temps dropping as low as -6C over far northern Utah Tuesday
afternoon. Overall, this system is a bit weaker than the one about
to move through, but should bring another round of decent
precipitation. Additionally, Tuesday maxes should run up to 10F
below seasonal normals with the colder airmass and continued cloud
cover, while temperatures remain seasonable over southern Utah.
Strong high pressure is expected to move in for Wednesday, resulting
in a rapid drying trend.
.LONG TERM (AFTER 00Z THURSDAY)...
A ridge of high pressure will build over the region Thursday and
Friday with significant warming of 700 millibar temperatures,
plus 6 to 8 Celcius, over much of forecast area. With a very dry
air mass in place, dry conditions will prevail.
A series of very weak upper level disturbances will slide from the
Pacific Northwest through the northern Rockies on Saturday and
Sunday, flattening the ridge. Given the weak nature of these
system and absence of moisture, should see nothing more than a
small increase in cloudiness, primarily across northern portions
of forecast area. Temperatures will remain above normal values.
.AVIATION...Northerly winds are expected to persist at KSLC through
04-06Z when they will switch to southerly. There is a 25 percent
chance this switch occurs earlier, between 02-03Z. These
southerlies may gust over 25 knots at times after 05z. Although
VFR conditions with cigs above 8000 feet will prevail, there is a
30 percent chance of showers and brief MVFR conditions impacting
UT...Wind Advisory until 9 AM MDT Monday for UTZ004-015-016-020-518.
For more information from NOAA`s National Weather Service visit...
For frequently asked questions about the Area Forecast Discussion