Flash Flood Warning 5, NWS Salt Lake City, UT

353 
WGUS75 KSLC 101335
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
735 AM MDT FRI MAY 10 2019

UTC053-101500-
/O.CON.KSLC.FF.W.0005.000000T0000Z-190510T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Washington UT-
735 AM MDT FRI MAY 10 2019

...THE FLASH FLOOD WARNING REMAINS IN EFFECT UNTIL 900 AM MDT FOR
EAST CENTRAL WASHINGTON COUNTY...

At 734 AM MDT, heavy rainfall was reported by several rain gauge 
reports earlier this morning.  Flash flooding is likely occurring 
across Zion National Park, even as the rain decreases in intensity.  

Some locations that will experience flooding include...
Zion National Park, Springdale and Rockville. 

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.

&&

LAT...LON 3742 11291 3714 11290 3715 11313 3744 11318

$$

CRK

142 
WGUS75 KSLC 101452
FFSSLC

Flash Flood Statement
National Weather Service Salt Lake City UT
852 AM MDT FRI MAY 10 2019

UTC053-101501-
/O.EXP.KSLC.FF.W.0005.000000T0000Z-190510T1500Z/
/00000.0.ER.000000T0000Z.000000T0000Z.000000T0000Z.OO/
Washington UT-
852 AM MDT FRI MAY 10 2019

...THE FLASH FLOOD WARNING FOR EAST CENTRAL WASHINGTON COUNTY WILL
EXPIRE AT 900 AM MDT...

The heavy rain has ended. Elevated flows will continue across Zion 
National Park through the morning.  Use caution entering any areas 
prone to flooding. 

LAT...LON 3742 11291 3714 11290 3715 11313 3744 11318

$$

CRK

Area Forecast Discussion
National Weather Service Salt Lake City UT
431 AM MDT Fri May 10 2019

.SYNOPSIS...An upper low will bring unsettled conditions to
the southern half of the area today through Saturday, while high
pressure builds across the north. This high will eventually
become the dominant weather feature by late in the weekend into
the first half of next week.

&&

.SHORT TERM (Through 00Z Tuesday)...Morning satellite imagery and
objective analysis depicts an elongating positively tilted upper
trough extending across the Great Basin, with an upper low
embedded with the base of this trough spinning over central
California. Meanwhile An upper ridge which has resided off the
Pacific Coast is slowly building inland across the Pacific
Northwest. As this ridge continues to build inland over the next
48 hours, the upper low will continue to drift southward as it
becomes cut off from the mean flow, eventually becoming suppressed
across northern Mexico during the latter half of the weekend into
early next week.

In the near term, large scale ascent associated with a low level
convergence zone associated with this low is lifting into
southwest Utah, and fueling fairly widespread rainfall (with snow
at the highest elevations) across southwest and south central
Utah. This axis will continue to drift northward a bit longer
before stalling across the area later this morning. Large scale
forcing is expected to weaken by this afternoon as the low drifts
further way from the area, allowing precipitation to become more
convective and increasingly tied to the terrain given a
combination of daytime heating, lingering moisture/instability
and weak flow. This will largely impact southern and perhaps
portions of central Utah.

Meanwhile easterly flow across northern Utah has again resulted in
gusty canyon winds along portions of the Wasatch Front north of
I-80, as well as the Cache Valley. Aside from the immediate area
near Farmington Canyon which has been gusting in to the mid to
upper 40s, most locations have remained well below advisory
criteria. Hi-res models suggest these winds have either peaked or
are close to their peak, and should drop off this morning. This is
also supported by a weakening and backing 700mb wind profile. As
such held off on any wind headlines.

As the aforementioned upper ridge continues to build inland drier
and warmer air will spread across northern and central Utah
beginning today, and continuing into the upcoming weekend.
Lingering moisture will maintain a threat of convection across the
south through at least Saturday, although the models have been
trending stronger with the ridge and further south with the
eventual track of the upper low. If this trend continues the
south may dry out by early in the weekend as well. For now have
held onto PoPs across the southern third of the area through
Saturday, trending downward Sunday before drying on Monday.

.LONG TERM (After 00Z Tuesday)...A broad ridge of high pressure
is expected to be centered over the forecast area to begin the
long term period, resulting in continued mild temperatures with
maxes running up to 10F above seasonal normals. Conditions should
be generally dry Tuesday into Wednesday, but enough lingering
moisture should exist under the ridge for a few showers and
thunderstorms, primarily over the higher terrain.

EC/GFS continue to indicate that the ridge will shift east of the
area Wednesday as a Pacific trough approaches the California
coast. Global models all eventually bring this system into the
area Thursday night/Friday. The system would bring with it a
noticeable cooldown in temperatures along with increased coverage
of showers and thunderstorms. With current model trends, have
bumped up POPs for day seven while trending POPs down elsewhere
with guidance now indicating a slower approach of this storm
system.

&&

.AVIATION...The SLC terminal will see VFR conditions through the
morning with mostly clear skies. With a canyon wind event
occurring north of the terminal, light easterly winds are expected
to prevail, though winds will shift to the west at times.
Northwest winds are expected to develop between 16Z and 18Z.

&&

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

Seaman/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