Text Products for AFD Issued by SLC

Area Forecast Discussion
Issued by NWS Salt Lake City, UT
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FXUS65 KSLC 192145
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
345 PM MDT Fri Apr 19 2024

.SYNOPSIS...Isolated rain and higher elevation snow showers will
continue Saturday for central and southern Utah. Dry and warmer
conditions will push in to end the weekend. Dry conditions will
last through the start of the week. More active weather is
forecasted later in the week.

&&

.SHORT TERM (Through 12Z Sunday)...A weak shortwave trough
positioned near the southern California and Nevada border has
brought enhanced cloud cover to Utah. It has provided enough lift
for isolated rain and snow showers for portions of central and
southern Utah. Precipitation has largely been within the
mountains. Some of that has spilled into adjacent valleys to the
east, but with a dry subcloud environment, much or all of the
moisture has evaporated before reaching valley floors. Showers
will taper off through the evening.

Similar conditions are forecasted Saturday. Synoptic flow will
transition to the northwest as an incoming ridge builds closer to
Utah. The aforementioned shortwave trough will push into Arizona
and New Mexico. Isolated rain showers, with snow showers above
roughly 9500 feet, are expected. Showers will taper off early in
the evening as a ridge pushes in. Temperatures will jump to 5-10F
warmer than normal throughout southwest Wyoming and northern Utah,
while southern Utah stays around 5-10F warmer than normal.

.LONG TERM (After 12Z Sunday)...Weak ridging and a warming air
mass on Sunday will bring another warm day - e.g. 70s to near 80
for northern Utah valleys and near 90 in St. George. The ridge
will be somewhat short-lived as the overall synoptic flow remains
more zonal and by Monday a trough moving through the Northern
Rockies will depress heights slightly and bring slightly cooler
conditions to at least northern Utah Monday. The weather will
remain quiet otherwise with the cooler air arriving in the form of
a weak dry front struggling to even generate clouds. Another
short-lived ridge axis Tuesday/Wednesday will bring temperatures
back to 10-15 degrees above normal. By this time, global models
are showing signs of a more spring-like convective pattern, with
potential for showers or even a thunderstorm over the higher
terrain of northern Utah as a trough digs upstream of our area
over the West Coast.

Looking at the range of ensemble solutions, there is high confidence
in unsettled weather (cooler with higher chances of precipitation)
over the Great Basin somewhere around the latter half of next week.
As is common this time of year, there is a lot of uncertainty as to
whether the mean trough will manifest as a closed low somewhere in
the Desert Southwest or a consolidated wave. Either way, ensemble
meteograms show a notable shift to at least normal temperatures if
not below normal as well as elevated precip chances from the end of
next week into the following weekend. Indeed, the CPC 6-10 and 8-14
day outlooks echo the same themes of above-normal precipitation
chances, while our area lies on the edge of high chance of below-
normal temperatures to our west - likely due to the uncertainty of
the longwave trough evolution as it moves inland. If such an
unsettled pattern does develop, cannot rule out thunder given the
time of year. Early 25th-75th percentile NBM projections are in the
neighborhood of 0.25-1.25" liquid for the mountains and trace to
0.5" for valleys, with amounts increasing from south to north across
the area.

From a snowmelt runoff perspective, we should see several melt
periods for the first half of next week followed by a slowing of the
melt with potential for accumulating mountain snow.

&&

.AVIATION...KSLC...VFR conditions are expected to prevail through
the TAF period under mid and upper level cloud cover. Winds will
persist out of a northerly direction, reverting back to a southerly
flow around 08Z. Between 03-08Z, there will likely be periods of
light and variable flow of 5kts or less. There is a 30% chance that
winds will revert to southerly before 08Z.

.REST OF UTAH AND SOUTHWEST WYOMING...VFR conditions are expected to
prevail across the forecast area through the TAF period.
Predominantly northerly winds are expected to prevail through the
late evening hours, reverting back to light drainage flows during
the overnight hours. Otherwise, scattered to broken mid and upper
level cloud cover will prevail through the early morning, briefly
clearing, then clouding up again late tomorrow morning.

&&

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

&&

$$

SHORT TERM...Wilson
LONG TERM...Van Cleave
AVIATION...Webber

For more information from NOAA`s National Weather Service visit...
http://weather.gov/saltlakecity
National Weather Service National Headquarters
