Special Weather Statement, NWS Salt Lake City, UT

Area Forecast Discussion
National Weather Service Salt Lake City UT
1024 AM MDT Wed Aug 9 2017

.SYNOPSIS...A upper level trough centered off the northern
California coast will continue to eject a series of weak weather
disturbances across northern Utah and southwest Wyoming today and
tonight. Moisture pooled to the south over Arizona will begin to
work north into southern Utah late in the week while northern Utah
starts trending drier.

&&

.DISCUSSION...Morning satellite analysis of the water vapor and
infrared imagery shows a deformation zone across northern
Nevada/southern Idaho/northwest Utah which is driving the current
convection. The highest precipitable water values are currently
across northern Utah, surpassing the 1 inch mark, while southern
Utah is about 0.75 inches. Increasing shear aloft of about 30
knots from northern to central Utah along with a convergent zone
as seen from the mid-upper levels will be key players in today's
activity. The weak shortwave rotating through northern Utah will
aide in development this afternoon of thunderstorms and showers.
The convective development should begin to fire off mid to late
afternoon, as advertised by high resolution models and remain
confined to central through northern Utah. Gusty winds and the
potential for small hail are possibilities. Have made some small
updates to the forecast for today, increasing the PoP values.

As the upper level jet continues to remain across southern Utah
and another shortwave moves through northern Utah for Thursday
into Friday, expecting similar conditions for convective set up
the next two days. Will have to reassess to see how each day plays
out, but similar patterns are in the set up for the next couple of
days.

&&

.AVIATION...Lingering shower activity from earlier this morning
will continue east away from the terminal with lingering
scattered clouds through the balance of the morning. The next weak
weather disturbance will move east-northeast out of Nevada this
afternoon. Increasing high-based clouds are anticipated through
the afternoon hours, with shower and thunderstorm activity likely
holding off until the arrival of the weather disturbance early
this evening. The main impact from this feature will be lightning,
gusty/erratic winds and ceilings near 8 kft. Very brief periods
of MVFR conditions could develop in heavy convective precip.

&&

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

DISCUSSION...Dewey
AVIATION...CONGER

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
457 AM MDT Wed Aug 9 2017

UTZ001>016-019>021-517-518-WYZ021-101300-
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-
457 AM MDT Wed Aug 9 2017

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

.DAY ONE...Today and Tonight

Scattered showers and thunderstorms are expected across mainly
the northern half of the outlook area today and tonight. Some of
the storms could produce locally heavy rainfall. Strong gusty
winds and hail may also accompany the storms late this afternoon
and evening.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Moisture is expected to gradually return to the south towards the
end of the week and into the weekend.

.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

Special Weather Statement
National Weather Service Salt Lake City UT
239 PM MDT WED AUG 9 2017

WYZ021-092115-
Southwest Wyoming WY-
239 PM MDT WED AUG 9 2017

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL UINTA COUNTY UNTIL
315 PM MDT...

At 238 PM MDT, National Weather Service doppler radar indicated a
strong thunderstorm near Robertson, or 28 miles east of Evanston...
moving east at 35 mph.

Penny to nickel size hail and winds in excess of 40 mph will be
possible.

Locations impacted include...
Lyman, Robertson, Millburne and Fort Bridger.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If threatening weather approaches, take shelter in a sturdy building.

Torrential rainfall is also occurring with this storm, and may lead
to localized flooding. Do not drive your vehicle through flooded
roadways.

&&

LAT...LON 4116 11051 4134 11052 4141 11005 4116 11004
      4115 11005
TIME...MOT...LOC 2038Z 266DEG 29KT 4126 11041

MT