Area Forecast Discussion
Issued by NWS Salt Lake City, UT
FXUS65 KSLC 212136
Area Forecast Discussion
National Weather Service Salt Lake City UT
336 PM MDT SAT MAY 21 2016
.SYNOPSIS...A broad upper level low pressure system will remain
over the western states well into the upcoming week. This low
pressure will maintain periods of unsettled spring like
conditions across the region throughout the week.
.SHORT TERM (through 06z Wednesday)...The upper low currently
centered across eastern Oregon will maintain a steady northeast
track into south-central Canada by early Sunday. A secondary
shortwave diving south along the west coast will fill in behind
the exiting Oregon low, maintaining the broad but loosely
organized mean trough across the interior west through the
Mostly clear skies earlier today across northwest Utah allowed for
convection to develop quickly early this afternoon. Some
organization noted along the moisture discontinuity north of the
drier air moving north through western Utah. A second area of
organized convection is also forming near the Nevada border in an
area of near 700mb convergence. Outside of an early afternoon
storm over the northern Wasatch Front, convection for the most
part has been short-lived pulse storms. See some potential for the
near 700mb boundary to become more active as it drift east
tonight. This low-level boundary supported by an apparent, albeit
weak shortwave crossing the Sierras and the 130+ knot upper jet
across southwest through northeast Utah should sustain some
convection overnight through early Sunday morning.
Looking at lingering terrain-based convection Sunday afternoon and
evening. The next shortwave diving south along the west coast
Monday will likely eject some moisture along with a weak shortwave
or two across the Great Basin late Monday night through Tuesday
evening. Suspect that the greatest areal coverage for convection
will remain across central and northern Utah through Tuesday
evening, with southern Utah seeing limited activity confined
mainly to the higher terrain.
.LONG TERM (after 06z Wednesday)...In the active weather pattern of
shortwaves, long range forecast models continue this trend with a
longwave trough settled over the Western CONUS through much of the
upcoming week. Weak temperature advection will lead temperatures to
be changed very little day to day. Expecting diurnally driven
convection day to day with the jet placement and southwest flow
pattern of the trough with embedded low situated across Nevada and
forecast to track eastward over northern Arizona and southern Utah.
Mid-level moisture content should be sufficient for showers and
thunderstorms to develop and diurnal heating as well as weak dynamic
lift will be important ingredients each day for convection. By late
week, forecast models are in agreement with the low tracking
eastward and becoming absorbed into the mean flow with yet another
cold upper low developing just off the Gulf of Alaska.
.AVIATION...Expect northwesterly winds to continue at the SLC
Terminal through the afternoon and into the evening. Winds are
expected to shift to the southeast between 05-07Z, though the wind
shift may be delayed as late as 09Z. Otherwise, showers will
continue across the area through about 03Z. Any showers will be
capable of gusty and erratic winds.
UT...Wind Advisory until 9 PM mDT this evening for UTZ013-020-021.
For more information from NOAA/s National Weather Service visit...
For frequently asked questions about the Area Forecast Discussion