Name: Wildfire in Idaho, April 21 to 25, 2021
Start: 2021-04-21T08:00
End: 2021-04-25T10:00
Location: Idaho

Where it happened

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The toll

Deaths: 0
Injuries: 0
Property damage: $200,000
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 PIH wrote it up.

A wildfire began on April 21st near Firth and strong southwest winds grew the fire from 100 acres on the 21st to 1,200 acres on the 22nd. Winds shifted to the northwest during the evening of the 22nd and the fire ran a different direction. Residents near and around Firth were evacuated. One home was destroyed along with several outbuildings. Most of the burned land was private land. The home that was destroyed was along 700 North which is where most of the evacuations occurred were homes along 700 North. The wildfire was a controlled burn that became out of control due to the strong winds. The fire was controlled by April 25th.

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 Pocatello, ID wrote its last area forecast discussion before the first event at Apr 21, 1:54 AM MST, 6 hours 6 minutes earlier.

Area forecast discussion, Apr 21, 1:54 AM MST, 6 hours 6 minutes before

Area Forecast Discussion
National Weather Service Pocatello ID
254 AM MDT Wed Apr 21 2021

.SHORT TERM...Today through Friday.

A low pressure system will pass through the central Great Basin
today. This system should stay far enough south that we will not see
any precipitation from it. Pesky northeasterly winds will continue
resulting in another day for lake wind advisories on the American
Falls Reservoir.

A weak trough will arrive Thursday and Friday from the northwest.
This will produce a few showers across the central mountains into
the northeast highlands. There's enough instability on Thursday that
an isolated thunderstorm is possible. Although most of the
precipitation will be north, wouldn't be surprised to see an
isolated shower or two across southern Idaho as well as the GFS,
WRF and 3km NAM are supporting that possibility. QPF and resulting
snowfall amounts with this system look very light with less than
a tenth qpf and less than an inch snowfall likely. Wednesday and
Thursday do look breezy. However, the southwesterly winds on these
days look sub-advisory levels right now.

13

.LONG TERM...Saturday through next Wednesday. The models, ensembles
and cluster analysis pretty agree on a slow moving storm beginning
to impact central and eastern Idaho Saturday. This will bring a
daily chance of showers with possible thunderstorms, especially as
the low moves closer early on next week. It looks like the low
finally clears us by Tuesday, potentially Wednesday. Temperatures
will be cooling down once again, with rain and snow possible at mid
and upper elevations. The track and timing of any pockets of heavier
precipitation will eventually determine if we see any snow down to
the lower valley floors. It will be breezy on a daily basis as well.
Keyes

&&

.AVIATION...VFR weather is expected. North to Northeast winds of 10-
15kts sustained are forecast at IDA, PIH and BYI. Keyes

&&

.PIH WATCHES/WARNINGS/ADVISORIES...
Lake Wind Advisory from 7 AM this morning to 9 PM MDT this
evening for IDZ054.

&&

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

1 wildfire. Local standard time, as filed.

Wildfire, Lower Snake River Plain

When: April 21, 8:00 AM MST to April 25, 10:00 AM MST
Where: Lower Snake River Plain forecast zone
Property damage: $200,000
Reported by: County Official
Coordinates: 42.860, -112.488 (the zone’s center; the record gives no point)

A wildfire began on April 21st near Firth and strong southwest winds grew the fire from 100 acres on the 21st to 1,200 acres on the 22nd. Winds shifted to the northwest during the evening of the 22nd and the fire ran a different direction. Residents near and around Firth were evacuated. One home was destroyed along with several outbuildings. Most of the burned land was private land. The home that was destroyed was along 700 North which is where most of the evacuations occurred were homes along 700 North. The wildfire was a controlled burn that became out of control due to the strong winds. The fire was controlled by April 25th.

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

More

Every storm in Idaho in 2021 Every state in 2021 This day in weather history Warnings in Idaho, April 2021

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: 953628.