Severe Thunderstorm Warning 32, NWS Salt Lake City, UT

663 
WWUS55 KSLC 230103
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
703 PM MDT Wed Jul 22 2020

UTC017-037-230115-
/O.CON.KSLC.SV.W.0032.000000T0000Z-200723T0115Z/
Garfield UT-San Juan UT-
703 PM MDT Wed Jul 22 2020

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 715 PM MDT
FOR EAST CENTRAL GARFIELD AND NORTH CENTRAL SAN JUAN COUNTIES...

At 703 PM MDT, a severe thunderstorm was located 12 miles north of
Ticaboo, or 40 miles south of Hanksville, moving east at 15 mph.

HAZARD...60 mph wind gusts and nickel size hail. 

SOURCE...Radar indicated. 

IMPACT...Expect damage to roofs, siding, and trees. 

Locations impacted include...
Hite Marina.

This includes the following highways...
 Utah Route 95 between mile markers 39 and 44, and between mile
markers 46 and 54.
 Utah Route 276 between mile markers 10 and 24.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

For your protection move to an interior room on the lowest floor of a
building.

&&

LAT...LON 3786 11032 3785 11034 3778 11034 3777 11038
      3767 11038 3767 11044 3764 11045 3773 11075
      3786 11074 3793 11030
TIME...MOT...LOC 0103Z 269DEG 12KT 3778 11064 

HAIL...0.88IN
WIND...60MPH
 
$$

Webber

473 
WWUS55 KSLC 230111
SVSSLC

Severe Weather Statement
National Weather Service Salt Lake City UT
711 PM MDT Wed Jul 22 2020

UTC017-037-230120-
/O.EXP.KSLC.SV.W.0032.000000T0000Z-200723T0115Z/
Garfield UT-San Juan UT-
711 PM MDT Wed Jul 22 2020

...THE SEVERE THUNDERSTORM WARNING FOR EAST CENTRAL GARFIELD AND
NORTH CENTRAL SAN JUAN COUNTIES WILL EXPIRE AT 715 PM MDT...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning will be allowed to expire.  However gusty
winds are still possible with this thunderstorm.

LAT...LON 3786 11032 3785 11034 3778 11034 3777 11038
      3767 11038 3767 11044 3764 11045 3773 11075
      3786 11074 3793 11030
TIME...MOT...LOC 0110Z 269DEG 12KT 3778 11061 

$$

Webber

Area Forecast Discussion
National Weather Service Salt Lake City UT
425 PM MDT Wed Jul 22 2020

.SYNOPSIS...Monsoonal moisture will impact portions of Utah
through much of the week. Thunderstorms will continue to be
possible across southern Utah into early next week.

&&

.SHORT TERM (Through 12Z Saturday)...Afternoon radar analysis
shows two main areas of convection, one area is across southern
Utah from roughly Cedar City to Capitol Reef National Park.
Mesoanalysis indicates this area is located in an area of 1000
J/kg or so of SBCAPE. Deep layer shear is on the order of
15-20kts. Storms have shown occasional periods of transitory
organization but by and large are weak, pulse type cells. Surface
dewpoints across southern Utah are from the upper 40s to upper 50s
but surface temperatures have been suppressed due to cloud cover
and precipitation most of the day. Expect this convection to
continue to move eastward with an associated risk of isolated
flash flooding.

The other area of convection is located near the Utah/Nevada
border. This area is located near an axis of higher deep layer
shear...near 30kts. SBCAPE is around 500 J/kg in this
area...though there is a fair amount of CIN. Expect this area to
gradually transition east and decrease in intensity over the next
several hours. The main threat in this area will be strong and
gusty winds as the sub-cloud environment is appreciably drier than
in southern Utah.

As activity largely diminishes after sunset...another round of
convection associated with this monsoon surge is expected Thursday
afternoon and evening. The main focus for this convection will be
across southern and eastern Utah. Much of the model guidance
supports destabilization and SBCAPE values near 500-1000 J/kg
across much of eastern and southern Utah by Thursday afternoon.
Deep layer shear will still be marginal for any storm
organization...with values near 20kts. The biggest threat with
this activity will be isolated flash flooding across areas in
eastern and southern Utah including Capitol Reef, the Swell, and
the Glen Canyon/Escalante area.

While drier air will advect into Utah in the wake of the shortwave
impacting the state Thursday...expect weak shortwaves embedded in
southwesterly flow to bring the threat of convection Friday
afternoon and evening across the higher terrain.

Given the drier conditions along the western border Thursday
afternoon and evening, issued a red flag warning for gusty winds
and low humidities...which is in contrast to the threat for
isolated flash flooding across eastern Utah.

.LONG TERM (After 12Z Saturday)...Global model ensemble means
indicate a mid level ridge to build over the Eastern Great Basin
through the weekend, with a somewhat drier southwesterly flow
setting up.  Despite southwest flow, enough residual moisture
expected to remain in place to justify chances for showers and
thunderstorms over southeastern third of forecast area Saturday
afternoon and evening.  With continued drying into Sunday, expect
only slight chance for convective activity over higher terrain of
southern and eastern portions of forecast area.

Ensembles diverge a bit Sunday night into Monday, with EPS suggesting
a somewhat more northward placement of upper ridge, and thus, drier
southwesterly flow than GEFS.  Given increasing precipitable water
values, especially in GEFS, slight chance to chance wording for
showers and thunderstorms over at least southeastern half of
forecast area looks good.

Temperatures should trend from nearly normal on Saturday to a few
degrees above normal for the latter portions of the extended period.

&&

.AVIATION...VFR conditions will prevail at KSLC, despite
shower activity persisting through roughly 23Z.  Given extensive
cloud cover and showers, any thunderstorm potential looks extremely
limited.  Southerly flow will switch to a southeast drainage wind by
03Z.

&&

.FIRE WEATHER...An ongoing monsoon surge will continue over the
next several days. Expect the highest threat of thunderstorms and
resulting gusty winds across the northwestern portion of Utah
this evening as well as southern and eastern Utah. Drier air will
begin to work into the state Thursday...with gusty winds and low
humidities expected along the Utah/Nevada border. A red flag
warning has been issued for this area. The best chance for wetting
rains will be across southern and eastern Utah Thursday afternoon
and evening. Another round of convection is expected across
southern and eastern Utah Friday and Saturday afternoon and
evening...though coverage and intensity will be less than
Thursday.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Red Flag Warning until 10 PM MDT this evening for UTZ478-479-
     481>484-495.

     Red Flag Warning from noon to 9 PM MDT Thursday for UTZ492-495.

WY...None.

&&

Kruse/Barjenbruch

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
424 AM MDT Wed Jul 22 2020

UTZ001>016-019>021-517-518-WYZ021-231030-
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-
424 AM MDT Wed Jul 22 2020

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

.DAY ONE...Today and Tonight

Monsoonal moisture will spread across Utah and southwest Wyoming
today. Over northern Utah and southwest Wyoming, storms will be
initially high-based, so gusty outflow winds will be the main
threat. In the more moist airmass over southern Utah isolated
flash flooding is possible, particularly for prone areas such as
slot canyons, burn scars, and normally dry washes.

.DAYS TWO THROUGH SEVEN...Thursday through Tuesday

Slight drying will occur over western Utah Thursday, but a moist
and unstable airmass will remain over the eastern half of the
outlook area, where flash flooding will continue to be a threat.
With further drying on Friday, the focus of afternoon showers and
thunderstorms will be over southeast Utah. Further drying is
anticipated over the weekend and into early next week.

.SPOTTER INFORMATION STATEMENT...

Spotter activation may be needed. Please relay any information
about observed severe weather to the NWS while following all
local, state, and CDC guidelines.

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
527 PM MDT Wed Jul 22 2020

UTZ005-230015-
Great Salt Lake Desert and Mountains UT-
527 PM MDT Wed Jul 22 2020

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL TOOELE COUNTY UNTIL 615
PM MDT...

At 526 PM MDT, National Weather Service Doppler radar indicated
strong thunderstorms 7 miles south of Clive, or 30 miles northwest
of Dugway English Village...moving northeast at 15 mph.

Wind gusts up to 50 mph will be possible.

Locations impacted include...
Clive, Knolls and Utah Test and Training Range South.

This includes Interstate 80 in Utah between mile markers 20 and 63.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Strong winds with these storms may occur well ahead of any rain or
lightning. Do not wait for the sound of thunder before taking cover.
SEEK SHELTER IMMEDIATELY inside a sturdy structure and stay away from
windows.

&&

LAT...LON 4042 11296 4050 11368 4078 11368 4083 11323
      4083 11287
TIME...MOT...LOC 2326Z 234DEG 14KT 4058 11314

Webber

Special Weather Statement
National Weather Service Salt Lake City UT
534 PM MDT Wed Jul 22 2020

UTZ013-020-518-230015-
Southern Utah Mountains UT-South Central Utah UT-San Rafael Swell UT-
534 PM MDT Wed Jul 22 2020

...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL GARFIELD COUNTY UNTIL 615
PM MDT...

At 532 PM MDT, National Weather Service Doppler radar indicated a
strong thunderstorm 20 miles southeast of Boulder, or 27 miles east
of Escalante...moving east at 25 mph into southern Capitol Reef
National Park.

Half inch hail will be possible.

This storm will remain over mainly rural areas of central Garfield
County.

This includes Utah Route 276 between mile markers 17 and 22.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 3766 11115 3783 11128 3802 11077 3775 11058
TIME...MOT...LOC 2332Z 247DEG 23KT 3778 11109

Webber