Text Products for AFD Issued by SLC

Area Forecast Discussion
Issued by NWS Salt Lake City, UT
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FXUS65 KSLC 202204
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
404 PM MDT Sat Apr 20 2024

.SYNOPSIS...High pressure over the Great Basin will result in dry
weather and temperatures 10-15 degrees above climo. Flattening of
the ridge on Monday will allow temperatures to cool a few degrees
before more warming through midweek. A stormy pattern returns for
most of the area by the middle of next.

&&

.SHORT TERM (Through 12Z/6AM Monday)...Dry conditions with
warming temperatures will prevail as a ridge builds into the Great
Basin. Ridging tomorrow will result in clear skies allowing for
temperatures to rise well above normal. Temperatures will be
running 10-15 degrees above climo for late April. There is a 49%
chance St. George reaches 90 degrees Sunday afternoon. Higher
valley locations across the state will be in the mid to upper 70s
with ~20% chance of reaching 80 degrees. The ridge will flatten a
bit by Monday morning as a trough passes by to our north resulting
in more zonal flow across the CWA.

.LONG TERM (After 12Z/6AM Monday)...A weak, shallow, and mostly dry
frontal boundary draped across the northern third of Utah will help
to cool temperatures in this area by about 5 degrees as compared to
Sunday. Otherwise, minimal change is anticipated for temperatures
going into Monday. Upper level ridging becomes a bit more pronounced
through Tuesday, helping reinstate warming across the northern
portions of the forecast area. By Tuesday afternoon, daytime highs
across Utah and southwest Wyoming will be pushing 10-15 degrees
above normal. Increasing low-to-mid level moisture will be
introduced into the region on Tuesday across northern Utah/
southwest Wyoming which will bring low chances of light afternoon
showers, primarily over the high terrain. A deeper southwest flow
will develop through the overnight hours, helping set the stage for
the northern half of the area to see the warmest day of the week.

Moving past Wednesday the forecast becomes a bit more complex as
there is generally high confidence in a Pacific trough moving inland
over the western U.S. This trough will bring a stout change in area-
wide conditions as there is also high confidence in seeing
measurable precipitation across a vast majority of the forecast
area, as well as a downward trend in temperatures. The uncertainties
moving forward with this trough lie heavily on the speed of the
progression of the system, which would ultimately influence how
quickly we begin seeing more widespread precipitation across the
area and how long it lasts. At least initially, the thinking is that
there will be a band of heavier precipitation tied to a frontal
boundary that will bring appreciable rainfall to the valley areas
(and snow above 8,500ft) with a transition to more convectively
driven showers as the center of the low translates overhead. At this
point in time, NBM precipitation probabilities show about a 60%
chance of exceeding 0.25 inches of rain at KSLC, and a 30% chance of
exceeding 0.5 inches. For the highest terrain, will likely see
periods of heavy snowfall but, again, there is still some
uncertainty revolving around how long, and where exactly, the
heaviest precipitation will fall.

Past the extended forecast period, it looks as if this mean
troughing could remain in place through the upcoming weekend and
into early next week. Not going to call any definitive shots at the
moment, however, the most recent 8-14 day outlook from the CPC shows
potential for near normal temperatures and above normal
precipitation for much of the forecast area.

&&

.AVIATION...KSLC...Clouds will diminish through the evening with
northwest winds transitioning to southeast around 04Z.

.REST OF UTAH AND SOUTHWEST WYOMING...Isolated showers for portions
of southern Utah, and clouds for southwest Wyoming and most of
Utah will diminish through the evening with light winds.

&&

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

$$

SHORT TERM...Mahan
LONG TERM...Webber
AVIATION...Wilson

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