Flash Flood Warning 52, NWS Salt Lake City, UT

944 
WGUS75 KSLC 250035
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
635 PM MDT Thu Aug 24 2023

UTC025-250200-
/O.CON.KSLC.FF.W.0052.000000T0000Z-230825T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
635 PM MDT Thu Aug 24 2023

...FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 8 PM MDT THIS EVENING 
FOR SOUTH CENTRAL KANE COUNTY...

At 635 PM MDT, Doppler radar indicated thunderstorms producing heavy 
rain across the warned area. Between 0.75 and 1.25 inches of rain 
have fallen. Flash flooding is ongoing or expected to begin shortly.

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

SOURCE...Radar.

IMPACT...Life threatening flash flooding of creeks and streams,
         urban areas, highways, streets and underpasses.

Some locations that will experience flash flooding include Coyote 
Creek and Wahweep Creek to their confluence.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Turn around, don't drown when encountering flooded roads. Most flood 
deaths occur in vehicles.

&&

LAT...LON 3731 11187 3715 11187 3705 11163 3707 11163
      3732 11177

FLASH FLOOD...RADAR INDICATED
FLASH FLOOD DAMAGE THREAT...CONSIDERABLE

$$

JW

819 
WGUS75 KSLC 250158
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
758 PM MDT Thu Aug 24 2023

UTC025-250208-
/O.EXP.KSLC.FF.W.0052.000000T0000Z-230825T0200Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Kane UT-
758 PM MDT Thu Aug 24 2023

...FLASH FLOOD WARNING WILL EXPIRE AT 8 PM MDT THIS EVENING FOR 
SOUTH CENTRAL KANE COUNTY...

The heavy rain has ended. Flooding is no longer expected to pose a 
threat. Higher flows are likely on Coyote Creek and Wahweap Creek 
overnight. Please continue to heed any road closures.

LAT...LON 3731 11187 3715 11187 3705 11163 3707 11163
      3732 11177

$$

JW

Area Forecast Discussion
National Weather Service Salt Lake City UT
304 PM MDT Thu Aug 24 2023

.SYNOPSIS...Monsoon moisture will remain across the region
through Friday. High pressure will bring a warming and drying
trend beginning Saturday, and continuing into early next week.

&&

.SHORT TERM (Through 12Z Saturday)...Afternoon satellite imagery
shows the well defined remnant circulation from Tropical Storm
Harold spinning across southeastern Utah. Extensive cloud cover
has thinned this afternoon, allowing for scattered convection
across the forecast area. Despite dew points in the 50s to low
60s, and PW values near or above 1", instability remains somewhat
meager owing to modest mid level lapse rates. However, this is
favoring very efficient rain processes as observed at several
mesonet locations across the Wasatch Plateau/western Uintas
earlier this afternoon, where 0.50 or greater in 30 minutes was
observed from otherwise innocuous looking convection. This threat
will persist into the evening hours, mainly along and east of the
I-15 corridor. Down-drainage storm motions across south central
Utah will elevate the flash flood potential from Zion east through
the Staircase and into the Glen Canyon Rec area.

The remnants of Harold will weaken and lift northeast into
northern Colorado/southern Wyoming by Friday, with ample low level
moisture lingering across the forecast area. Again, modest mid
level lapse rates will limit instability, and hi-res guidance
seems to reflect this with scattered at best convection firing
Friday afternoon. Given the ample moisture a threat of flash
flooding will remain, but will be more localized given the limited
convective coverage.

.LONG TERM (After 12Z Saturday)...There is good agreement from
models on a retrograding ridge that will allow for much drier
conditions for the weekend into the week. The best moisture content
locally Saturday will be for eastern Utah. Precipitable water values
will be around 1" throughout eastern Utah, while drier conditions
build into western portions of Utah as synoptic winds transition to
southwest.

The ridge will retrograde into the southwest Sunday. Shower and
thunderstorm chances will decrease, with the best chances near
higher terrain. Most of Utah will have dry conditions with
temperatures warming above normal. Valley high temperatures will get
into the 80s and 90s, with upper 90s or low 100s for lower
Washington County.

A trough will be largely stationary off the coast of the PacNW, and
as the ridge retrogrades more into the start of the week, that
trough will build inland. Monday conditions will be similar to the
weekend. As the trough pushes into the PacNW, enhanced southwest
flow will build into northern Utah. This will allow for warmer
temperatures, with highs 5-10F warmer than normal.

The trough will flatten the ridge out Wednesday, with stronger winds.
Gusts will reach more than 30 knots for southwest Wyoming and most
of Utah. Temperatures will drop around 5F from Tuesday.

More active weather is forecast by Wednesday as ridging builds to
the southeast with monsoonal moisture advection into the southwest.

&&

.AVIATION...KSLC...VFR conditions will prevail through the
remainder of the period for the KSLC terminal. Isolated and slow
moving storms will be possible through this evening which could
create brief gusty and erratic winds. A northerly lake breeze will
be late to establish, if at all, before switching back to
southerly this evening.

.REST OF UTAH AND SOUTHWEST WYOMING...Mostly VFR conditions will
persist throughout the period. Isolated slow moving storms will
linger through the evening before diminishing. These storms will
create gusty and erratic winds and could briefly reduce
categories. Otherwise, winds will be light and variable with a few
CIGs near ridgetop that could create brief mountain obscuration.

&&

.FIRE WEATHER...An anomalously moist airmass will continue to
bring elevated humidity along with scattered showers and
thunderstorms capable of producing heavy rainfall across the
region through Friday. A chance in the large scale weather pattern
will begin Saturday, as high pressure strengthens across the
region bringing a warming and drying trend over the weekend into
early next week. By Tuesday this high will shift east of the area,
allowing a very warm and dry southwesterly flow to spread across
the region. This may result in locally breezy to windy conditions
Tuesday and Wednesday, particularly across western valleys. This
warmer and drier period looks to be short lived, as monsoon
moisture returns to the region during the latter portion of next
week.

&&

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

Seaman/Wilson/Mahan

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