Area Forecast Discussion
Issued by NWS Salt Lake City, UT

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FXUS65 KSLC 270333
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
933 PM MDT Mon Jul 26 2021

.SYNOPSIS...With high pressure just east of the area, monsoonal
moisture will spread northward across Utah and southwest Wyoming
by Tuesday. Unsettled conditions will continue through the
remainder of the week.

&&

.DISCUSSION...The low that had been tracking across the Desert
Southwest has moved off the southern California coast this
evening, adjusting the persistent ridge axis just east of the
area. Resultant southerly flow aloft has allowed deep moisture
pooled over southern Utah to begin to spread northward, with PWs
of 1.0 inch now reaching as far north as the northwest desert.
Best moisture is still over southwest Utah, where PWs up to 1.5
inch have been observed. Widespread convection focused over
central and southern Utah produced a variety of flash flooding
issues, especially in and around Cedar City. However, some showers
made it as far north as the south portion of the Salt Lake Valley.
With the loss of daytime heating, most of the remaining convection
is dissipating, though showers over the northwest desert may last
into the overnight hours. Additionally, gusty winds have developed
over the northwest desert due to a meso high over west central
Utah, with a few gusts in excess of 50 mph observed. As this high
weakens overnight, so will these winds.

Southerly flow will continue to spread moisture out across Utah
and southwest Wyoming tomorrow. PWs in excess of 1.0 inch will
become more widespread, but this will result in a net decrease in
moisture over southern Utah. Increasing stability behind a weak
upper level disturbance will also curb the convective threat over
western and far southern Utah, with the best storms tomorrow
anticipated over the higher terrain of northern and central Utah.
Little change in the pattern is anticipated for Wednesday but some
repositioning of the low will allow moisture and instability to
increase further for Thursday and Friday, potentially resulting in
more widespread convection.

Updated the forecast earlier to adjust POPs with current trends.
No additional updates planned.

&&

.AVIATION...KSLC...The SLC terminal will see VFR conditions
through the overnight hours with some scattered clouds. Gusty
southerly winds are expected to weaken somewhat by the overnight
hours. Lingering smoke will cause some reduction in visibility,
but visibilities should remain above 6SM.

Rest of Utah and southwest Wyoming...VFR conditions are expected
across the entire area through the overnight hours. Lingering
shower activity over southern and western Utah will tend to
dissipate late this evening, but some pockets of gusty and/or
erratic winds are possible. Smoke will cause some reduction in
visibility across northern Utah and southwest Wyoming, but
visibilities should remain above 6SM.

&&

.FIRE WEATHER...Southerly flow aloft will spread monsoonal
moisture across the entire fire district by Tuesday. The focus of
showers and thunderstorms will shift to northern and central Utah
for Tuesday into Wednesday. As additional moisture and instability
enter the district Thursday, convection is expected to increase in
coverage across the entire district, increasing the potential of
wetting rains.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Flash Flood Watch until midnight MDT tonight for UTZ122-124-125.

WY...None.
&&

$$

Traphagan

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

For frequently asked questions about the Area Forecast Discussion
visit...
http://weather.gov/saltlakecity/general/afd_faqs.php


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