Area Forecast Discussion
Issued by NWS Salt Lake City, UT
FXUS65 KSLC 192101
Area Forecast Discussion
National Weather Service Salt Lake City UT
301 PM MDT THU MAY 19 2016
.SYNOPSIS...High pressure will shift east today ahead of the next
Pacific storm. This system will slowly cross the Pacific
Northwest through the weekend.
.SHORT TERM (THROUGH 06Z MONDAY)...Upper low clearly indicated on
afternoon satellite imagery across the Pacific Northwest along
with a significant jet streak rounding the base of the trough.
This trough will slowly dig southeastward and intensify through
Friday and remain across the Pacific Northwest/Northern California
area into the weekend.
The associated cold front is approaching the northwestern corner
of the state this afternoon. Ahead/near the cold front, expect
convection to continue to develop this afternoon and evening.
With a well mixed/dry subcloud environment/inverted V type
profiles, the biggest threat will be microburst winds associated
with any convection. Expect at least a few reports near 60 mph
this afternoon/evening...primarily across the Great Salt Lake
Desert...though the threat for gusty microburst winds extends to
the central/northern Wasatch Front/Cache Valley and adjacent
terrain. Small hail can`t be ruled out, but with fairly minimal
instability, only the strongest storms would be capable of any
sizable hail. Any convection should quickly diminish after sunset
with the loss of daytime heating.
As the upper level low slowly moves southward overnight and into
Friday, the cold front will retreat northward. Very strong 700mb
flow, the order of 50kts or more, will support very strong winds
across western Utah. Though the flow is a bit weaker further east,
winds will also be quite gusty across eastern Utah. Current high
wind warnings and wind advisories for Friday look to be on track.
The microburst threat will likely continue at least across
portions of northern Utah Friday afternoon/evening.
The upper level trough will remain across the Northwest
Saturday...though the 700mb flow will have decreased. Still,
expect a windy day on Saturday for much of the CWA once more.
.LONG TERM (AFTER 06Z MONDAY)...While the main trough will linger
over the Pacific Northwest through the extended period a series of
shortwave troughs will traverse northern Utah. These troughs will
bring slightly cooler than normal temperatures to most of the CWA
through the extended. In addition...isolated to scattered showers
and thunderstorms are expected every day across northern half of
Utah through this period...with the greatest threat likely Wednesday
as the strongest feature in this series moves through. Southern Utah
will mainly stay dry under a prevailing southwest flow...although
isolated thunderstorms can not be ruled out over the higher terrain.
.AVIATION...Winds at the SLC terminal are expected to switch to the
northwest around 23Z-01Z due to a cold front passing through the
area. Showers and thunderstorms are likely to accompany this front;
gusty erratic winds, ceilings below 7000 feet, and lightning are the
most likely impacts at the terminal. Rain will increase even more
across northern Utah after 02z, and there is a slight chance of MVFR
conditions in moderate to heavy rain.
.FIRE WEATHER...Strong winds will be the main weather concern Friday
with RH values lowering into the teens over most valleys. Fuels are
still moist but combine the winds of today...tomorrow and Saturday
and some of the finer fuels could begin to dry due to the
desiccating winds. Isolated showers and thunderstorms will visit
southern half of the fire district through the weekend...while
northern Utah will see more scattered showers and thunderstorms.
UT...Wind Advisory from noon to 10 PM MDT Friday for UTZ002-004-013-
High Wind Warning from noon to 10 PM MDT Friday for UTZ003-005-
For more information from NOAA/s National Weather Service visit...
For frequently asked questions about the Area Forecast Discussion