Wildfire in Utah, August 24 to 31, 2018

Name: Wildfire in Utah, August 24 to 31, 2018
Start: 2018-08-24T12:00
End: 2018-08-31T23:59
Location: Utah

August 24 to 31, 2018 · NWS SLC · 1 event in 1 county or zone

The Bald Mountain Fire in northern Utah began on August 24 and burned for over a month before being contained. Note that this episode continued through September into October.

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 1

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS SLC wrote it up.

The Bald Mountain Fire in northern Utah began on August 24 and burned for over a month before being contained. Note that this episode continued through September into October.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Salt Lake City, UT wrote its last area forecast discussion before the first event at Aug 24, 8:49 AM MST, 3 hours 11 minutes earlier.

Area forecast discussion, Aug 24, 8:49 AM MST, 3 hours 11 minutes before

Area Forecast Discussion
National Weather Service Salt Lake City UT
949 AM MDT Fri Aug 24 2018

.SYNOPSIS...High pressure will shift east of the area today. A
series of disturbances will graze northern Utah this weekend,
with one bringing a mostly dry cold front through Sunday night
into Monday. A warming and drying trend will commence through
midweek.

&&

.DISCUSSION...It's another summer day in Utah...with the threat of
convection across a good portion of the CWA. Somewhat subtle
factors will influence where convection will develop...though for
most of the state, a lack of deep forcing will result in
convective genesis along the higher terrain/elevated heat sources.

Morning satellite analysis indicates a subtle wave feature ahead
of a stronger shortwave crossing northern Nevada/southern Idaho.
This is colocated with the entrance region to a jet maxima. Expect
this forcing to aid in the development of convection...but the
timing on these features will likely bring relative subsidence
into the Wasatch Front sometime this afternoon.

Morning mesoanalysis shows elevated surface dewpoints across much
of the state, with the highest values across the far southwest.
Little surface based instability exists at this time...with
deep layer shear near 30 kts across portions of northern Utah.
HREF guidance indicates SBCAPE values may approach 750-1000 J/kg
for a short window along the Wasatch Front...with those values
consistently in place across areas along the
Wasatch/central/southern Mountain crest and east...and then into
southwest Utah. Less deep layer shear exists across southern Utah.

Convective threat for the Wasatch Front will likely lie with
timing and the ability for the Oquirrhs and mountains adjacent to
southwestern Utah Lake to fire early this afternoon. Added
isolated thunderstorms into the forecast for these areas...and
will monitor trends. Needless to say...this threat is conditional.

Across the remainder of the previously mentioned area, sufficient
instability and deep moisture remain in place...and thunderstorms
will be possible in these areas. Deep layer shear is marginal for
any potential organization at best...but isolated flash flooding
in prone areas can't be ruled out today. Storm motions will favor
a northeastward trajectory today, which is unfavorable for most
basins in southern Utah.

Updated the forecast to adjust PoPs toward current trends and
ancillary grids impacted by this change. Will continue to monitor
trends through the late morning and early afternoon and adjust as
needed.

&&

.AVIATION...A slight chance of a thunderstorm exists at the KSLC
terminal between 17-23z today, but direct impact is only 15 percent.
Gusty or erratic southerly outflow in excess of 30 mph would be the
most likely operational impact. Outside of this, southerly winds
will become moderately gusty this afternoon, with a 60% chance of
switching to the northwest after 22/23z.

&&

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

Kruse/Merrill

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

Event by event

1 wildfire. Local standard time, as filed.

Wildfire, Wasatch Mountains South of I-80

When: August 24, 12:00 PM MST to August 31, 11:59 PM MST
Where: Wasatch Mountains South of I-80 forecast zone
Reported by: Other Federal Agency

The Bald Mountain Fire was a lightning caused wildfire that began on August 24. Initially only about 20 acres, it experienced exceptional growth on September 12 due to high winds and low relative humidity, and eventually burned 18,620 acres. The Bald Mountain Fire, and nearby Pole Creek Fire that ignited in September, led to the evacuation of 6,000 people from 2,000 homes at the height of the incident, as well as caused numerous road closures. The combined costs to fight the Bald Mountain Fire and the Pole Creek Fire were $23.8 million. Note that this event continued through September into October.

What these are

Wildfire: A fire burning in wildland vegetation, with its acreage and damage where known.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Utah in 2018 Every state in 2018 This day in weather history Warnings in Utah, August 2018

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 780783.