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000
FXUS65 KSLC 131625
AFDSLC

Area Forecast Discussion
National Weather Service Salt Lake City UT
1025 AM MDT Wed Sep 13 2017

.SYNOPSIS...A series of storm systems will bring cooler and
wetter conditions to Utah and southwest Wyoming for the second
half of the work week. A milder southwesterly flow will return
for the weekend.

&&

.DISCUSSION...A high centered over nwrn Mexico and a closed low
centered off the srn CA coast dominate the weather over the
intermountain region this morning. Southerly flow between these
features continues to spread moisture north into UT with the
deepest moisture still to our west. Embedded weak waves in the are
generating convection over the nrn CWA and over sern NV that is
about to spread into swrn UT.

The activity over the north should continue to weaken thru midday
but expect terrain based cells to form this aftn mostly south of
I-80, drifting into the ern valleys. The activity moving into swrn
UT should end up focused over the west central valleys.

The CA low moves slowly east today thru tonight with the deeper
moisture spreading into UT. Expect an increase in convection this
evening across the CWA with some activity lingering thru the
night.

The closed low is forecast to open up and lift into swrn UT during
the day tomorrow, as a trof deepens over the PacNW and nrn
Rockies. The increasing upper support ahead of this feature should
bring fairly widespread showers to the CWA but the greatest
coverage should be over the southwest in the morning spreading
across the south and east in the aftn.

With the deep moisture in place and lift from the trof, some cells
could become strong with a threat of isolated severe storms. There
will also be a threat of heavy rain along with isolated flash
flooding. The severe threat would be hail and gusty/erratic winds.

This threat should shift out of the CWA by mid evening but a
leading short wave from the digging trof in the nrn branch pushes
a cold front into the north with precip becoming widespread across
the north overnight.

The cold front gets re-enforced on Fri as the upper trof digs into
the nrn Great Basin with showers continuing along and behind the
front.

Updated earlier to lower pops across the north today but increased
pops across the southwest this morning. No additional changes
planned at this time.

&&

.AVIATION...Southerly winds at the KSLC terminal are expected to
shift to northwest around 18-20z. Showers in the vicinity of the
terminal could produce gusty erratic outflow winds at times.

&&

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

$$

Wilensky

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