Flash Flood Warning 34, NWS Salt Lake City, UT

942 
WGUS75 KSLC 242109
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
309 PM MDT Sun Jul 24 2022

UTC055-242230-
/O.CON.KSLC.FF.W.0034.000000T0000Z-220724T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
309 PM MDT Sun Jul 24 2022

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 430 PM MDT THIS 
AFTERNOON FOR WEST CENTRAL WAYNE COUNTY...SPECIFICALLY FOR THE 
SULPHUR CREEK AREA WITHIN CAPITOL REEF NATIONAL PARK...

At 309 PM MDT, Additional light to moderate rainfall has occurred 
across the Sulphur Creek drainage since in was first reported that a 
12-15 inch flood wave was moving down Sulphur Creek. Additional 
rainfall in this area remains likely through this evening.

HAZARD...Life threatening flash flooding. Thunderstorms producing
         flash flooding.

SOURCE...Park Rangers at Capitol Reef National Park reported.

IMPACT...Life threatening flash flooding of creeks and streams
         that feed into the Sulphur Creek slot canyon area.

Some locations that will experience flash flooding include...
  Capitol Reef National Park and Fruita.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Remain alert for flooding even in locations not receiving rain. Dry 
washes, streams, and rivers can become raging killer currents in a 
matter of minutes, even from distant rainfall.

Flooding is occurring or is imminent. It is important to know where 
you are relative to streams, rivers, or creeks which can become 
killers in heavy rains. Campers and hikers should avoid streams or 
creeks.

&&

LAT...LON 3837 11144 3836 11137 3835 11131 3830 11114
      3827 11114 3827 11116 3828 11121 3828 11124
      3827 11128 3827 11135 3831 11142

FLASH FLOOD...OBSERVED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

GM

868 
WGUS75 KSLC 242226
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
426 PM MDT Sun Jul 24 2022

UTC055-242236-
/O.EXP.KSLC.FF.W.0034.000000T0000Z-220724T2230Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Wayne UT-
426 PM MDT Sun Jul 24 2022

...FLASH FLOOD WARNING WILL EXPIRE AT 430 PM MDT THIS AFTERNOON FOR 
WEST CENTRAL WAYNE COUNTY...

Flood waters have receded. Flooding is no longer expected to pose a 
threat. Please continue to heed remaining Capitol Reef National Park 
closures.

LAT...LON 3837 11144 3836 11137 3835 11131 3830 11114
      3827 11114 3827 11116 3828 11121 3828 11124
      3827 11128 3827 11135 3831 11142

$$

GM

Area Forecast Discussion
National Weather Service Salt Lake City UT
431 AM MDT Sun Jul 24 2022

.SYNOPSIS...A weak disturbance will bring the threat of convection
to portions of northern and eastern Utah this morning and
afternoon. Additional showers and thunderstorms are expected to
form across central and southern Utah today. As moisture continues
to increase in association with another monsoon surge today
through at least Wednesday, expect an increased threat of flash
flooding across central and southern Utah.

&&

.SHORT TERM (Through 12Z Wednesday)...Morning satellite and upper
air analysis indicate a tightly wound shortwave near the Idaho
panhandle. Meanwhile a deeply entrenched monsoonal pattern
continues across the Desert Southwest. Embedded in the flow around
an elongated ridge are several shortwaves. The first, which at
times has looked like a potential MCV, is transiting southeastern
Utah this morning. Yet another convectively induced shortwave
trough is noted across southern Arizona.

Current radar trends show two things. One is an area of light
showers and occasional embedded thunderstorms from roughly Delta
to Evanston. This convection has developed near the edge of the
initial moisture surge. Another area of somewhat stronger
convection is located south of Boulder (the previously mentioned
MCV).

A majority of available CAMs support the continued shift of this
MCV north and east through the morning...developing widespread
precipitation by 16-17Z from roughly Salt Lake County and east.
There is some potential for microbursts with this area of
convection, particularly on the north and west edge. This
precipitation gradually shifts north and east into
Colorado/Wyoming by late afternoon.

Timing the next convectively induced shortwave...expect PVA
associated with this shortwave to shift into southern Utah by
this afternoon. While there is a fair amount of cloud cover in the
area, expect enough breaks in the cloud in the subsident area
behind the first wave to allow for some destabilization. 00Z HREF
SBCAPE mean suggests values around 500-1000 J/kg by 20Z across
southern Utah. There may be some local enhancement of deep layer
shear...though the background deep layer shear is on the order of
20-25kts.

CAMs support the development of fairly widespread convection this
afternoon and evening across the southern half of Utah. PWATs will
average between 1-1.5". Storm motions look to favor an eastward
progression. All of this is to say, the ingredients are coming
together to support an increased threat of flash flooding across
southern Utah this afternoon and evening.

With little change in the upper level pattern, combined with
continued moisture advection associated with the monsoon surge,
expect instability values to be even higher Monday afternoon and
evening, with the potential for slower storm motions. By this
time, storm motion may be more toward the southeast, which would
favor a higher threat for flash flooding across Capitol Reef, the
Swell and the Grand Staircase and potentially Zion National Park.
Today's day shift may need to consider issuing a flood watch for
portions of southern Utah Monday afternoon and evening.

The monsoon surge will continue into Tuesday, though with
additional dry air advection across northern and central Utah in
response to a trough shifting across the High Plains, expect net
drying across central Utah, with the threat more confined to
southern Utah by Tuesday afternoon and evening.

Outside of flash flood/thunderstorm threats, several large
wildfires are in progress across the greater Yosemite area. HRRR
smoke modeling advects this smoke into portions of northern Utah
by later this afternoon. While surface visibility restriction is
not expected to be impacted, a net increase in haze may be
noticeable. Another wildfire northwest of St. George may also
advect some smoke into portions of southwest Utah.

.LONG TERM (After 12Z Wednesday)...Monsoonal moisture will be
decreasing by Wednesday, but conditions that could result in flash
flooding are expected. Ensemble guidance has good agreement with
a trough moving into the northern plains. A strong ridge is
expected to build into the PacNW with that, which will decrease
monsoonal moisture advection. Through later in the week, this will
result in warmer conditions, especially for southwest Wyoming and
northern Utah where dry conditions are expected. Precipitable
water values of close to 1" are expected for southern Utah.
Several shortwaves pushing through from the south will work with
available moisture through Friday to bring scattered showers and
thunderstorms. Most of these will initiate over higher terrain
with a storm motion to the northeast. Convection is expected to
diminish each day during the evening.

Temperatures will stay consistently around 5F warmer than climo
in southwest Wyoming and northern Utah. Clouds and showers will
result in near average temperatures in southern Utah.

As the trough transitions eastward, models bring ridging into the
Four Corners for the weekend with increased moisture advection.

&&

.AVIATION....KSLC...Winds will prevail from the south through the
day. Gusts near 20 knots are expected. Isolated showers with light
rain and gusty, erratic outflow winds are possible, with the best
chances from 15-21Z. Clouds will decrease into the overnight with
light southeast winds.

.REST OF UTAH AND SOUTHWEST WYOMING...A monsoon surge will bring
the threat of showers and thunderstorms with heavy rain to central
and southern Utah this afternoon and evening. Across northern
Utah, mainly near and south of SLC and east of Tooele, expect
showers and a few thunderstorms with the biggest threat gusty and
erratic microburst winds through the morning and into the
afternoon. Precipitation chances decrease around 00Z for the
north, but scattered showers are possible in southern Utah through
the overnight hours.

&&

.FIRE WEATHER...A weak disturbance embedded in the next monsoon
surge will bring the threat of showers and a few thunderstorms as
far north as Salt Lake City today. Additional showers and
thunderstorms in the deeper moisture are expected to develop
across southern Utah this afternoon and evening. Wetting rains
will be likely with any thunderstorms from Sunday through at least
Tuesday across southern Utah...while relatively dry and hot
conditions continue across northern Utah.

&&

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

Kruse/Wilson

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