348
FXUS65 KSLC 090501
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
1101 PM MDT Sat Aug 8 2026

.KEY MESSAGES...

- Dangerous heat will persist across portions of northern Utah and
  the low desert of southern Utah into Sunday.

- A marginal risk of excessive rainfall will continue across
  portions of Utah through the next five days.

- The threat of flash flooding will be most significant across
  slot canyons, normally dry washes, slick rock areas and recent
  burn scars.

&&

.DISCUSSION...High pressure over the Four-Corners region will
continue to support a monsoon surge into Utah over the next 5-7
(or more) days. Evening analysis indicates that a potential MCV is
developing over central Arizona. This may rotating around the
ridge into Utah Sunday...potentially increasing the threat of
flash flooding. This will be something to watch Sunday.

Looking at CAMS this evening, fairly widespread convection is
forecast across much of the region. HREF suggest peak rainfall
rates Sunday will be between 0.25 to 0.50 inches per hour,
however, looking at ground truth today, stronger storms were
capable of rates a bit higher than 0.50 inches per hour given slow
storm motions.

Adjusted heat headlines based on latest trends. With lows
struggling to fall below 80 degrees for the lower deserts of
southern Utah, extended the Excessive Heat Warnings for lower
Washington County, Zion National Park and Glen Canyon National
Recreation Area. Even though highs will be slightly cooler Sunday,
the lack of any meaningful relief overnight will continue to
create cumulative heat stress...especially for those without
adequate cooling and/or hydration.

With cooler temperatures forecast across central Utah, cancelled
going heat products for these areas.

Expect convection to continue each afternoon and evening with an
attendant flash flooding threat through at least the next 5 to 7
days.

&&

.AVIATION...KSLC...Southeasterly winds will continue overnight,
likely shifting to northwesterly between 19-20z. However, isolated
thunderstorms developing first over higher terrain between 20-00z
may result in gusty and erratic outflow winds. A second round of
a few showers and thunderstorms may linger into the evening
between 01-06z, though confidence is low on timing. VFR conditions
will prevail with hazy skies from wildfire smoke.

REST OF UTAH AND SOUTHWEST WYOMING...Winds will continue to
subside as lingering showers across mainly southwestern Utah
diminish over the next couple of hours. By 10z or so, winds will
be largely light and terrain-driven. Scattered showers and
thunderstorms are expected to develop after 18-19z across much of
the state; any storms will be capable of gusty and erratic outflow
winds. VFR conditions will largely prevail outside of areas near
local wildfires and outside any blowing dust from outflow winds.

&&

.FIRE WEATHER, Issued 152 PM MDT Sat Aug 8 2026...
With high pressure centered near the Four Corners area, monsoonal
moisture will continue to increase over the area, spreading north
and east tonight before lingering in place through the coming
week. This will lead to diurnal showers and thunderstorms across
the area. Showers and thunderstorms will become more widespread
across the area tomorrow. Storms across southern Utah will
continue to become increasingly wet tomorrow, while across the
north, some storms near the northern/eastern edge of the moisture
surge may initially begin on the drier side tomorrow. As
humidities increase, wetting rain potential will increase areawide
through the coming week. Gusty outflow winds in excess of 45 mph
will remain possible with showers and thunderstorms through at
least tomorrow. Outside of showers and thunderstorms, winds are
expected to remain relatively light and terrain-driven.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Extreme Heat Warning until midnight MDT Sunday night for UTZ101-
     102-104-105.

     Heat Advisory until midnight MDT Sunday night for UTZ103-106-107-
     116.

     Extreme Heat Warning until 9 PM MDT Sunday for UTZ123-124-131.

WY...Red Flag Warning until 9 PM MDT Sunday for WYZ277.

&&

$$

Kruse/Cunningham/Cheng

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visit... http://weather.gov/saltlakecity