Severe Thunderstorm Warning 28, NWS Salt Lake City, UT

Area Forecast Discussion
National Weather Service Salt Lake City UT
1231 PM MDT Sat Jun 20 2026

.KEY MESSAGES, Issued 1220 PM MDT Sat Jun 20 2026...

- Gusty west to southwest winds with gusts in excess of 30 mph
  will combine with very low relative humidity values to bring
  critical fire weather conditions to areas of central and
  southern Utah east of I-15 on Saturday.

- Widely scattered showers and thunderstorms, mostly dry, will
  develop over northern Utah this afternoon and evening, with the
  best chances near the Idaho border. Strong outflow winds in
  excess of 50 mph can be expected with these storms, along with
  dry lightning.

- High pressure will rebuild for early next week, keeping
  conditions very dry with a steady warming trend in temperatures.
  The potential for heat related illness could increase for some
  valleys by the middle of the upcoming week.

&&

.DISCUSSION, Issued 1220 PM MDT Sat Jun 20 2026...

An upper trough slowly making its way through the northern
Rockies has pushed a cold front through much of northern Utah.
Ahead of this feature gusty west to southwest winds and very low
relative humidity will continue to bring critical fire weather
conditions across much of central and southern Utah east of I-15
through this evening. A Red Flag Warning remains in effect for
these areas. Further north, closer to the upper forcing and cold
air aloft associated with the upper trough, a band of showers and
thunderstorms is gradually weakening as it lifts along the Idaho
border region and will continue to do so into the early afternoon
hours.

Hi-res guidance is in good agreement developing scattered
convection by mid afternoon across northern Utah, with the threat
shifting east of the Wasatch Crest into the Bear River Valley and
southwest Wyoming late this afternoon into the early evening.
Strong outflow winds will be possible with this convection, with
the greatest threat east of the Wasatch Crest extending into Uinta
County WY. Further west, a slightly more stable post-frontal
environment may mute the microburst threat a bit, which seems to
be indicated in hi-res guidance. Regardless, this activity should
largely exit the forecast area by mid-evening.

A more stable airmass will settle across the forecast area Sunday
cooling daytime temperatures to near climo. This reprieve will be
short lived, as mid level ridging amplifying across the region
early next week will bring a warming trend, and a return to hot
and very dry conditions. By Thursday this ridge looks to break
down as an upper trough approaches the Pacific Coast. Spread in
the guidance lends to a considerable amount of uncertainty
regarding how this trough evolves as it moves inland, but there
is some potential for moisture to be pulled northward into the
forecast area by Thursday...something to keep an eye on.

&&

.AVIATION, Issued 1220 PM MDT Sat Jun 20 2026...

KSLC...Scattered showers and TS will develop this afternoon,
potentially impacting the terminal between 22-02z with lightning and
gusty outflow winds. There is a 10% chance that VRB wind gusts
briefly exceed 50kts, and a 30% chance of lightning within 5 miles.
VFR conditions will prevail, though could briefly go MVFR with
blowing dust with any outflow. Elevated smoke will likely remain far
to the south.

REST OF UTAH AND SOUTHWEST WYOMING...Scattered showers and TS will
develop this afternoon across N-UT/SW-WY between ~21-03z. Any
showers will be capable of producing gusty and erratic outflow
winds, with a 10 percent chance of gusts briefly exceeding 45kts.
VFR conditions will prevail across most areas, though wildfire smoke
may produce locally MVFR VIS near wildfires. Elevated smoke may be
seen across southern UT in particular.

&&

.FIRE WEATHER...A weather system  crossing the northern Rockies is
pushing a cold front through northern Utah early this afternoon.
Ahead of this front, very low RH combined with gusty winds is
resulting in another day of critical fire weather conditions across
central and southern Utah mainly east of I-15. To the west of I-15,
although wind speeds are a little weaker fire weather conditions
remain elevated, and a few localized pockets of critical fire weather
conditions may develop this afternoon where terrain influences
locally enhance wind gusts.

Along and behind this front, daytime heating will allow for widely
scattered high based showers and dry thunderstorms across northern
Utah this afternoon. These storms will be most numerous near the
Idaho border region and will be accompanied by strong outflow
winds in excess of 40 mph, with a few gusts exceeding 60 mph
possible. As the cold front sags into west central Utah, isolated
dry thunderstorms will be possible late this afternoon and early
evening across northern portions of zone 492 and potentially
impact the Iron fire.

A slightly cooler airmass will spread across the area Sunday
dropping daytime temperatures to near normal across the state.
Despite this, very low RH daytime RH across central and southern
Utah will continue to result in elevated fire weather conditions.
High pressure will bring a warming trend through the first half of
next week, with a return to hot and very dry conditions by
Tuesday. This high will break down later in the week, however
confidence is low regarding how this plays out. Solutions Thursday
into Friday range from a drier southwest flow potentially resulting
in critical fire weather conditions, to a influx of moisture
bringing a decent chance for showers and thunderstorms.

&&

.SLC WATCHES/WARNINGS/ADVISORIES...
UT...Red Flag Warning until 10 PM MDT this evening for UTZ478.

     Red Flag Warning until 10 PM MDT this evening for UTZ482-484-488-
     489-493-494-496-498.

WY...None.
&&

PUBLIC...Seaman
AVIATION...Cunningham
FIRE WEATHER...Seaman

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

Special Weather Statement
National Weather Service Salt Lake City UT
327 PM MDT Sat Jun 20 2026

UTZ101-202200-
Great Salt Lake Desert and Mountains UT-
327 PM MDT Sat Jun 20 2026

...A strong thunderstorm will impact portions of south central Box
Elder County through 400 PM MDT
...

At 327 PM MDT, Doppler radar was tracking a strong thunderstorm 16
miles north of Utah Test and Training Range North, or 54 miles east
of Montello, moving east at 25 mph.

HAZARD...Wind gusts up to 50 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Great Salt Lake North of the Causeway, Utah Test and Training Range
North, Gunnison Island, and Lakeside.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4116 11319 4133 11322 4147 11284 4117 11272
TIME...MOT...LOC 2127Z 248DEG 21KT 4126 11314

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

BW

Special Weather Statement
National Weather Service Salt Lake City UT
346 PM MDT Sat Jun 20 2026

UTZ101-103-202215-
Eastern Box Elder County UT-Great Salt Lake Desert and Mountains UT-
346 PM MDT Sat Jun 20 2026

...A strong thunderstorm will impact portions of northeastern Box
Elder County through 415 PM MDT
...

At 346 PM MDT, Doppler radar was tracking a strong thunderstorm near
Howell, or 15 miles west of Tremonton, moving east at 30 mph.

HAZARD...Wind gusts up to 50 mph and half inch hail.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects. Minor damage to outdoor objects is
         possible.

Locations impacted include...
Tremonton, Howell, Promontory, Penrose, Bothwell, Thatcher, and
Golden Spike Historic Site.

This includes Interstate 84 between mile markers 33 and 39.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4162 11257 4176 11259 4181 11224 4161 11220
TIME...MOT...LOC 2146Z 262DEG 25KT 4169 11248

MAX HAIL SIZE...0.50 IN
MAX WIND GUST...50 MPH

BW

<!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>

<!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>