Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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000
FXUS65 KSLC 011150
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
450 AM MST Wed Mar 1 2017

.SYNOPSIS...An increasingly dry and warmer west-northwesterly flow
aloft will set up for the latter half of the week. Precipitation
could return to region late in the weekend.

&&

.SHORT TERM (THROUGH 12Z SATURDAY)...The upper trough continues to
exit east out of the forecast area this morning. Warm advection will
develop today, although a northwesterly flow aloft will remain in
place. A few weak snow showers continue to linger across northern
Utah this morning owing to shallow instability, but as the airmass
trends drier and more stable through the day, expect these showers
to gradually diminish.

A ridge will start to build into the area tomorrow and remain in
place through Friday. This will bring dry and mild conditions with
max temperatures approaching climatology in many areas tomorrow and
exceeding it on Friday. Weak storm systems moving by north of the
area will bring periods of mid/high clouds to northern Utah during
this time.

.LONG TERM (After 12Z Saturday)...The flow over the forecast area is
progged to shift to the southwest on Saturday in response to a
trough approaching the Pacific coast. This system is expected to
move onshore Sunday before crossing the forecast area Sunday evening
into Monday. Winds ahead of the system should start to increase on
Saturday but are expected to ramp up in earnest during the day
Sunday. Global models are indicating 700mb over western Utah in
excess of 50 kts by Sunday afternoon, which could translate into
rather strong winds at the surface.

EC/GFS looking a bit different from the model runs at this time
yesterday, now showing a system that could have significant impacts
for the state, particularly northern Utah, as opposed to the grazing
system indicated yesterday. The system takes a more southerly track
in the GFS compared to the EC. As a result, its solution indicates a
colder airmass over the state (as cold as -15C at 700mb by Monday
morning, as opposed to -12C in the EC) and brings precip through
southern Utah. The track of the EC would confine precipitation to
northern and central Utah. Both continue to show a strong frontal
boundary on the leading edge of the trough moving into northwest
Utah late Sunday afternoon before sweeping across the area Sunday
evening/Monday morning. The EC solution is also a bit faster exiting
the forecast area, as it shuts off most precip by Monday afternoon.
The back edge of the trough lingers into Tuesday morning, allowing
for additional showers in cold pool instability.

Latest GFS indicated a weak wave crossing Utah and southwest Wyoming
during the day Wednesday, providing enough moisture and instability
for some precip over the higher terrain of northern Utah. After day
seven, the GFS shows strong high pressure moving back in while the
EC holds onto a more unsettled pattern.

&&

.AVIATION...The SLC terminal will see VFR conditions throughout the
day with some scattered clouds. Southeast winds are expected to
shift to the northwest between 19Z and 21Z, but there is a 30
percent chance this shift will occur later than expected or will not
occur.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...None.
WY...None.
&&

$$

Cheng/Traphagan

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



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