Special Weather Statement, NWS Salt Lake City, UT

Area Forecast Discussion
National Weather Service Salt Lake City UT
448 PM MDT Mon Jul 17 2017

.SYNOPSIS...A ridge of high pressure will remain in place across
the region through mid week, resulting in a continuation of hot
temperatures. Lingering moisture will continue to bring scattered showers
and thunderstorms to the area today, followed by a drying trend on
Tuesday. Monsoon moisture will spread into the area Wednesday and
Thursday and may bring the potential for heavy rain to central
and southern Utah.

&&

.SHORT TERM (Through 12Z Thursday)...Upper level ridge centered
over the southern plains will shift slowly east through mid week.
Residual moisture in place across much of Utah this afternoon
resulting in scattered showers and storms across much of the
state. SBCAPE and precipitable water values are highest across
southern Utah although limited shear there lends storms more to
producing heavy rain than severe weather. Further north, near the
northern extent of the convection deep layer shear values of
30-40 knots indicate that a little more storm organization is
possible. Anticipate that convection will diminish after sunset in
most areas, although isolated showers may longer through the
night across southern Utah.

A drying trend will occur across northern Utah on Tuesday as the
upper high elongates bringing drier air into Utah. Anticipate
that storms will largely be confined to the southern half of Utah
and the Uinta mountains on Tuesday. On Wednesday, the models are
in good agreement that a strong monsoon surge brings deep moisture
into central and southern Utah and then into northern Utah
Wednesday night. Precipitable water values in excess are expected
for much of the state with values in excess of 1.25" across
southern Utah. GFS also indicates a a mid level shortwave moving
north out of Arizona on wednesday which would provide support for
more widespread convection. Certainly see the potential for flash
flooding across central and southern Utah with very deep moisture,
deep warm cloud layers, and the possibility of larger scale
forcing. As is always the case with such events timing of any
shortwave forcing is critical.

Temperatures will remain above normal across the area with
overnight lows remaining well above normal. Temperatures will
drop back a bit on Wednesday, especially across southern Utah,
with the increased coverage of showers and storms.

.LONG TERM...(After 12Z Thursday)...Deep moisture will continue to
stream into Utah Thursday, with PW values of 1.2-1.4" across
southern Utah and 1.0-1.2" across northern Utah. Thursday will
likely be another active convective day across Utah, though
extensive cloud cover could limit activity across central and
southern Utah. A shortwave trough moving slowly across central Utah
into SW Wyoming and upper level diffluence associated with the right
entrance region of a jet streak positioned across ID, should allow
for an increase in convective coverage across northern Utah Thursday
afternoon. A few organized storms could be possible across far
northern Utah near the UT/ID/WY border as 0-6 km bulk wind shear
increases to around 40 knots.

A mid-level trough pushing across the Montana/Canadian border will
act to flattened the ridge and bring in drier air into northern Utah
Friday. A slow drying trend will take place through the weekend
across central and southern Utah, with isolated convection expected
across the higher terrain of southern Utah Sunday and Monday, while
northern and central Utah remain mainly dry.

Forecast highs Thursday, Friday, and Saturday will remain near
average across Utah, before warming a few degrees above normal
Sunday into early next week as an upper level ridge begins to
amplify across the Western U.S.

&&

.AVIATION...Southerly winds are expected at the SLC terminal
through 00Z, then a band of thunderstorms will likely bring erratic
winds in excess of 30 mph with a 30 percent chance of exceeding 45
mph. Thunderstorms should impact the terminal for about 1 hr from
00z until 01Z. Winds will likely return southeast about 03Z.

&&

.FIRE WEATHER...Upper level ridge remains in place over the southern
plains today with southwest flow aloft over Utah. Scattered
showers and thunderstorms this afternoon will decrease in
coverage by late evening. Drier air overspreads much of northern
Utah on Tuesday limiting the coverage of shower and storms to
central and southern Utah and in the Uinta Mountains. As the
upper level ridge shifts east by mid week, much deeper moisture
will lift north into Utah greatly expanding the coverage of
showers and storms on Wednesday and Thursday and also bring the
potential for flash flooding to southern Utah. It is not out the
question that there may be some dry thunderstorms on the leading
edge of the moisture across northwest Utah on Wednesday.

Relative humidity values will be lower on Tuesday, especially
across northern and central Utah where drier overspreads the
region. Much higher afternoon relative humidity readings can be
expected on Wednesday and Thursday for much of the state as
monsoon moisture spreads through the region.

&&

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

SHORT TERM...Graham
LONG TERM...Lukinbeal
AVIATION...Struthwolf
FIRE WEATHER...Graham

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
535 AM MDT Mon Jul 17 2017

UTZ001>016-019>021-517-518-WYZ021-181300-
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-
535 AM MDT Mon Jul 17 2017

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

.DAY ONE...Today and Tonight

Isolated to scattered showers and thunderstorms will develop
by this afternoon and continue into the evening. These showers
and thunderstorms may produce brief gusty winds and/or brief heavy
rain.

.DAYS TWO THROUGH SEVEN...Tuesday through Sunday

Isolated to scattered showers and thunderstorms will develop again
Tuesday afternoon, mainly over the higher terrain and across
southern Utah.

The potential for showers and thunderstorms will increase across
the outlook area Wednesday and Thursday. Heavy rain will be a
possibility, leading to an increased threat of flash flooding
especially across prone drainages in southern Utah.

.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
500 PM MDT MON JUL 17 2017

UTZ003-005-172345-
Great Salt Lake Desert and Mountains UT-
Salt Lake and Tooele Valleys UT-
500 PM MDT MON JUL 17 2017

...SIGNIFICANT WEATHER ADVISORY FOR SOUTH CENTRAL BOX ELDER AND
NORTHEASTERN TOOELE COUNTIES UNTIL 545 PM MDT...

At 459 PM MDT, National Weather Service doppler radar indicated
strong thunderstorms along a line extending from 28 miles north of
Knolls to 12 miles north of Dugway...and moving northeast at 40 mph.

Wind gusts of 40 to 55 mph will be possible.

Locations impacted include...
Grantsville, Stansbury Park, Delle, Hat Island, Lakeside, Lake Point,
Gunnison Island and Erda.

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 4151 11298 4069 11223 4031 11268 4113 11348
TIME...MOT...LOC 2259Z 228DEG 37KT 4112 11336 4042 11267

AL

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SALT LAKE CITY UT
503 PM MDT MON JUL 17 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0450 PM     TSTM WND GST     19 WNW DUGWAY           40.35N 113.08W
07/17/2017  M60 MPH          TOOELE             UT   MESONET

            MESONET STATION DPG14

&&

ALUKIN

Special Weather Statement
National Weather Service Salt Lake City UT
552 PM MDT MON JUL 17 2017

UTZ002>005-007-008-180030-
Wasatch Mountains South of I-80 UT-Wasatch Mountains I-80 North UT-
Great Salt Lake Desert and Mountains UT-Southern Wasatch Front UT-
Northern Wasatch Front UT-Salt Lake and Tooele Valleys UT-
552 PM MDT MON JUL 17 2017

...SIGNIFICANT WEATHER ADVISORY FOR SALT LAKE...CENTRAL DAVIS...
NORTHWESTERN UTAH AND EAST CENTRAL TOOELE COUNTIES UNTIL 630 PM
MDT...

At 551 PM MDT, National Weather Service doppler radar indicated
strong thunderstorms along a line extending from 9 miles north of
Stansbury Park to near Cedar Fort...and moving northeast at 35 mph.

Wind gusts up to 50 mph will be possible.

Locations impacted include...
Salt Lake City, West Valley City, Sandy, Layton, Murray, Bountiful,
Tooele, Farmington, West Jordan, Taylorsville, South Jordan, Lehi,
Draper, Riverton, Cottonwood Heights, Midvale, Kaysville, Holladay,
American Fork and South Salt Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 4110 11197 4045 11165 4029 11215 4082 11248
TIME...MOT...LOC 2351Z 239DEG 28KT 4078 11235 4040 11211

AL/RG

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>Service Notice</title>
  <link rel="stylesheet" href="index.css">
</head>
<body>
  <main class="wrap">
    <section class="card" role="status" aria-live="polite">
      <div class="status" id="status">Temporary Notice</div>
      <h1 id="headline">This service is currently unavailable.</h1>
      <p id="message1">
        The site you requested is temporarily down for maintenance or an unexpected outage.
      </p>
      <p id="message2">
        Please try again in a few minutes.
      </p>
      <p class="small" id="detail">
        If you are an administrator, restore upstream service and remove the redirect/fallback rule when normal operations resume.
      </p>
    </section>
  </main>
  <script src="index.js"></script>
</body>
</html>