Scientific Forecaster Discussion
fxus65 kslc 200326
Area forecast discussion
National Weather Service Salt Lake City Utah
926 PM MDT Thu Apr 19 2018
Synopsis...an upper level low pressure system will slowly make
its way across the region tonight through Friday. High pressure
will bring a warming and drying trend for the upcoming weekend.
Discussion...evening satellite imagery and objective analysis
show an upper low spinning near the Utah/NV/AZ triple point, with
the associated frontal boundary having lifted into eastern Utah.
Regional radar imagery indicates showers have been on the increase
across southwest Utah in proximity to this upper low, however
large dew point depressions even within the Post frontal airmass
coupled with rather weak forcing is resulting in little if any of
this moisture reaching the surface. Anticipate an increase in
activity overnight as a region of low-mid level thermal advection
currently noted across northern Utah along the northern periphery
of the upper low persists/strengthens and spreads southward. Snow
levels should remain above the valley floors for the most part,
with accumulating snowfall in the higher terrain not expected to
be particularly heavy given rather modest forcing. As such have
held off on any sort of winter headlines tonight through tomorrow
across the central and southern mountains.
Post frontal winds across southern and eastern Utah were gusty
this evening but not particularly strong, and as such have allowed
going Wind Advisory to expire for those areas. However a rather
tight pressure gradient is forecast to develop across northwest
Utah overnight through Thursday morning, and should support strong
gusts near Wendover as well as along State Route 30 in far
northwest Utah. As such have issued a Wind Advisory for these
areas through mid morning Friday. Additionally an easterly
gradient will likely support gusty canyon winds along the northern
Wasatch front overnight, however lack of substantial 700mb support
should significantly limit gust potential. For now have included
windy wording in the forecast but this will need to be monitored
The upper low is forecast to continue slowly eastward toward the
central rockies during the day Friday. This should result in a net
decrease in precipitation through the day, with the two most
persistent areas like being southwest Utah within a region of
lingering wrap around moisture/thermal advection, and the north
slopes of the uintas where an upslope component to the low level
flow will prevail through much of the day.
In the wake of this low mid level ridging will bring a warming
trend through the upcoming weekend.
Aviation...north winds are expected to prevail at kslc overnight
through the day Friday. VFR conditions are expected to prevail
overnight, however ceilings are expected to develop and lower
below 7 kft late tonight.
Utah...Wind Advisory until 10 am MDT Friday for utz005.
For more information from noaa's National Weather Service visit...