Flash Flood Warning 16, NWS Salt Lake City, UT

731 
WGUS75 KSLC 140318
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
918 PM MDT FRI JUL 13 2018

UTC053-140430-
/O.CON.KSLC.FF.W.0016.000000T0000Z-180714T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Washington UT-
918 PM MDT FRI JUL 13 2018

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 1030 PM MDT FOR
EAST CENTRAL WASHINGTON COUNTY...

At 914 PM MDT, Doppler radar indicated over one inch of rain has 
fallen over eastern portions of Zion National Park. The North Fork 
of the Virgin River is already experiencing higher flows due to this 
heavy rain. Expect flows along the North Fork of the Virgin River to 
remain elevated through late this evening.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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 3737 11290 3723 11290 3715 11303 3737 11302

$$

LC

607 
WGUS75 KSLC 140425
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
1025 PM MDT FRI JUL 13 2018

UTC053-140432-
/O.EXP.KSLC.FF.W.0016.000000T0000Z-180714T0430Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Washington UT-
1025 PM MDT FRI JUL 13 2018

...THE FLASH FLOOD WARNING FOR EAST CENTRAL WASHINGTON COUNTY WILL
EXPIRE AT 1030 PM MDT...

Heavy rainfall has ended over Washington County as of 1025 pm, so 
the flash flood warning for the North Fork of the Virgin River and 
surrounding drainages will be allowed to expire as scheduled at 1030 
pm. Water levels and flows will likely remain elevated the next 
couple of hours before gradually receding through the overnight 
hours.

LAT...LON 3737 11290 3723 11290 3715 11303 3737 11302

$$

ES

Area Forecast Discussion
National Weather Service Salt Lake City UT
332 PM MDT Fri Jul 13 2018

.SYNOPSIS...High pressure remains in place across the Great
Basin with a dry air mass over northern Utah through the weekend.
Moisture will linger over central and southern Utah through
Saturday, with some drying taking place on Sunday.

&&

.SHORT TERM (Through 06Z Tuesday)...Another typical July day
across the CWA, with an ongoing monsoonal surge across southern
Utah. As has been the case the last several days, sufficient
instability has developed...however deep layer shear remains
minimal. Convection has developed along the higher terrain of
central and southern Utah. A significant outflow boundary is noted
progressing south-southwestward near and west of Bryce Canyon.
This outflow boundary will be moving into the axis of instability
across southwestern Utah. Deeper convection has already been
noted as this outflow boundary has progressed southward over the
last hour or so. Expect thunderstorms to congeal into a common
cold pool and continue to move south to southwestward into the
evening. This evolution is supported by CAM guidance as well.

The upper level ridge has strengthened over the last 24 hours and
this may providing an increase in subsidence and a net drying
trend. That said, areas prone to flash flooding such as slot
canyons, dry washes, slick rock and burn scars may experience
flash flooding this afternoon and evening. This includes Zion
National Park...and those who may have plans in the park should
pay attention to the weather this afternoon and evening.
Remember...even if the thunderstorm isn't overhead, flash flooding
can still impact downstream locations.

A subtle shortwave rotating around the center of the ridge will
help to shunt moisture north and east through Saturday afternoon
and evening. This should shift the thunderstorm threat further
north and east, though the biggest threat for flooding will be
confined to burn scars for central and northern Utah.

In the wake of this shortwave and the shifting of the mean ridge
position...drier and hotter conditions will build into the area
for Sunday and Monday.

.LONG TERM (After 06Z Tuesday)...High pressure is expected to build
over Nevada Tuesday before the axis shifts over Utah for Wednesday
and Thursday. This will allow for a quick drying trend for all but
far southern Utah and should bring very warm temperatures for the
middle of the week. In the drier and more stable airmass there
should be a relative lull in convection, but some should still be
possible over the higher terrain as well as parts of southern Utah.

EC/GFS indicate the ridge axis will shift east of the forecast area
late Thursday into Friday, allowing a more southerly flow to develop
over Utah and southwest Wyoming, drawing moisture back into the area
and increasing coverage of convection through day seven.

&&

.AVIATION...Northerly winds will prevail at the SLC terminal through
about 03-04Z then shift to the southeast. No weather concerns
through the TAF period.

&&

.FIRE WEATHER...Deep moisture remains in place across southern Utah
this afternoon. Another round of showers and thunderstorms with
wetting rains will continue into late evening...particularly
across southwestern Utah. A weak disturbance rotating around the
high will temporarily bring moisture and associated thunderstorms
north and east Saturday. By Sunday, much of the district will be
drier...and this trend toward hot and dry conditions will continue
into next week.

&&

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

Kruse/Traphagan/Struthwolf

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

Hazardous Weather Outlook
National Weather Service Salt Lake City UT
659 AM MDT Fri Jul 13 2018

UTZ001>016-019>021-517-518-WYZ021-141200-
Cache Valley/Utah Portion-Northern Wasatch Front-
Salt Lake and Tooele Valleys-Southern Wasatch Front-
Great Salt Lake Desert and Mountains-Wasatch Mountain Valleys-
Wasatch Mountains I-80 North-Wasatch Mountains South of I-80-
Western Uinta Mountains-Wasatch Plateau/Book Cliffs-
Western Uinta Basin-Castle Country-San Rafael Swell-
Sanpete/Sevier Valleys-West Central Utah-Southwest Utah-
Utahs Dixie and Zion National Park-South Central Utah-
Glen Canyon Recreation Area/Lake Powell-Central Mountains-
Southern Mountains-Southwest Wyoming-
659 AM MDT Fri Jul 13 2018

This Hazardous Weather Outlook is for the western two thirds of
Utah and southwest Wyoming.

.DAY ONE...Today and Tonight

With a rather moist air mass in place, showers and thunderstorms
will be scattered over central and southern Utah, primarily this
afternoon and evening. The primary concern is the potential for
heavy rain over southern Utah, with flash flooding a possibility.

.DAYS TWO THROUGH SEVEN...Saturday through Thursday

There will be a potential for showers and thunderstorms,
primarily over southern Utah and the higher terrain of central
Utah, through the period.

.SPOTTER INFORMATION STATEMENT...

Weather spotters are encouraged to report significant weather
conditions according to standard operating procedures.

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

For information on potential road travel impacts visit...
http://www.udottraffic.utah.gov/roadweatherforecast.aspx