Drought in Montana, August 1 to 31, 2021

Name: Drought in Montana, August 1 to 31, 2021
Start: 2021-08-01T00:00
End: 2021-08-31T23:59
Location: Montana

August 1 to 31, 2021 · NWS GGW · 16 events in 16 counties and zones

Even though a few beneficial storms passed through the region in August, it was not enough to alleviate ongoing extreme drought conditions that expanded into more locations throughout the month.

Where it happened

Every event with a place to put it; 16 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 16

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 GGW wrote it up.

Even though a few beneficial storms passed through the region in August, it was not enough to alleviate ongoing extreme drought conditions that expanded into more locations throughout the month.

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 Glasgow, MT wrote its last area forecast discussion before the first event at Jul 31, 9:00 PM MST, 3 hours earlier.

Area forecast discussion, Jul 31, 9:00 PM MST, 3 hours before

Area Forecast Discussion
National Weather Service Glasgow MT
1000 PM MDT Sat Jul 31 2021

.DISCUSSION...

AFTERNOON UPDATE:
A good chunk of the time this afternoon was pouring over wind
data sets for the Little Rockies. Attempted to use 90 Percentile
of NBM for wind gusts only to find that it was just a couple knots
above the operational average. With such a narrow deviation, the
lighter than expected gusts will not currently be enough to exceed
elevated to critical fire weather conditions to justify a Red
Flag Warning this afternoon. Will allow the next couple shifts to
keep an eye on the remaining forecast in case the watch needs to
upgraded rather than dropped, but with only RH being a problem,
that is not likely.

Highest variability in the Forecast continues to show up around
Thursday and afterward. In yesterday's afternoon forecast the
shortwave on southwest flow that passes through Montana was pegged
for Thursday afternoon. This has backed up 12 hours to Friday
morning over the last 24 hours. The ridge appears to be delaying
this lift from entering the area and the trend may continue. If
it backs up to Friday afternoon we may still be in business for
severe, but as it currently stands it should be just showers and
light thunderstorms overnight. Deviations in ensembles are still
wide for this period so confidence in specifics is low here
onward. GAH
830AM UPDATE:
A quick update was performed to add in rain showers and
thunderstorm chances to northern and western Phillips county which
are receiving a few isolated thunderstorms on the radar and the
total lightning network. The only operational model that caught
them this morning was the Canadian NH which seems to point towards
these showers dying out around noon. All other model solutions
were dried out in QPF.

Have removed the HRRRSmoke out for this morning and early
afternoon as the GLAMP appears to be the only operational model
to catch on to clear to barely hazy skies based on its primary
observations ingest. GAH

MORNING DISCUSSION:
Upper level ridging will remain the dominant weather feature
across Montana through at least midweek. The result for tangible
weather will be a continuation of the hot and dry conditions.
Surface winds will be a little higher tomorrow, enough to prompt
the addition of a Fire Weather Watch for the Little Rockies (Fire
Weather Zone 135) for tomorrow. Far western parts of Petroleum and
Phillips Counties (in the far western parts of Fire Weather Zones
134, 136, and 137) may also reach that elevated to near-critical
level as well.

By late week, the ridge begins to flatten out as an upper level
trough approaches the Pacific Northwest. Operational models
suggest a disturbance riding out ahead of the main trough around
Thursday, which should trigger the area's next greatest chance of
showers and storms. Once that trough/disturbance moves through,
the ridge re-builds in between the Pacific Northwest upper low and
the by-then departing trough over the Upper Mississippi Valley.
The net result of this is a continuation of the heat, at least
until the Pacific Northwest trough makes its way inland and
towards us.

97

&&

.AVIATION...

FLIGHT CATEGORY: VFR - MVFR.

WIND: Light and variable overnight. E-NE 5-15 kts on Sunday.

DISCUSSION: Upper level ridging will keep the area mainly dry the
next couple days although an isolated thunderstorm is possible.
Main issue continues to be the varying amounts of haze and smoke
moving through the area from distant wildfires. Haze could briefly
reduce visibility to MVFR at times.

GAH/RMB

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch from Sunday afternoon through Sunday evening
for MTZ135.

&&

weather.gov/glasgow

The radar

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

Open the radar archive at this moment

Event by event

16 drought. Local standard time, as filed.

Drought, Sheridan

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Sheridan forecast zone
Reported by: Department of Highways
Coordinates: 48.721, -104.505 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions in Sheridan County were at (D2-Severe), with the exception of the extreme southwest portion of Sheridan County which remained in (D3-Extreme) drought. On the third week of August, (D3-Extreme) expanded into southern and western areas of Sheridan county, while the northeastern half of Sheridan county remained in (D2-Severe). These conditions continued through the remainder of the month.

Drought, Daniels

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Daniels forecast zone
Reported by: Drought Monitor
Coordinates: 48.784, -105.549 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions in Daniels County were at (D2-Severe) in all but the southeastern areas and far western tip of the county, which were in (D3-Extreme) drought. During the third week of August, the entire county worsened to (D3-Extreme) conditions. At the end of the month the western third of Daniels County worsened to (D4-Exceptional) conditions while the eastern two thirds of the county remained in (D3-Extreme) conditions.

Drought, Eastern Roosevelt

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Eastern Roosevelt forecast zone
Reported by: Drought Monitor
Coordinates: 48.295, -105.016 (the zone’s center; the record gives no point)

To start the month of August, ongoing drought conditions (D3-Extreme) were in place across the western and southeastern part of Eastern Roosevelt County, while the northeastern part of Eastern Roosevelt county remained in (D2-Severe) drought. By the third week all of Eastern Roosevelt County was in (D3-Extreme) drought. By the end of August, the far southwestern corner had worsened to (D4-Exceptional) drought while the rest of the county remained in (D3-Extreme) conditions.

Drought, Richland

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Richland forecast zone
Reported by: Drought Monitor
Coordinates: 47.788, -104.561 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions (D3-Extreme) covered most of Richland County with the exception of the far southeastern corner which was in (D2-Severe) drought. By the end of the month, the northwestern two thirds of Richland County had worsened to (D4 Exceptional) with the far southeastern corner remaining in (D2-Severe) and the rest of eastern Richland County remaining in (D3-Extreme) conditions.

Drought, Dawson

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Dawson forecast zone
Reported by: Drought Monitor
Coordinates: 47.266, -104.899 (the zone’s center; the record gives no point)

To start August, all of Dawson County was in (D3-Extreme) drought conditions. By the third week of August, the far southern edge of Dawson County worsened to (D4-Exceptional) drought conditions. By the end of the month, all but the far eastern edge of Dawson County had worsened to (D4-Exceptional) conditions, that area remained in (D3-Extreme) drought.

Drought, Wibaux

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Wibaux forecast zone
Reported by: Drought Monitor
Coordinates: 46.965, -104.249 (the zone’s center; the record gives no point)

To start the month of August, all but the extreme northeast corner of Wibaux County was in (D3-Extreme) drought conditions with the extreme northeast corner being in (D2-Severe) drought. On the third week of August, the southern two thirds of Wibaux County worsened to (D4-Exceptional) conditions. The northeastern corner remained in (D2-Severe) conditions and the rest of the northern part of Wibaux County remained in (D3-Extreme) conditions. These conditions remained the same through the end of the month.

Drought, Prairie

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Prairie forecast zone
Reported by: Drought Monitor
Coordinates: 46.861, -105.378 (the zone’s center; the record gives no point)

To start the month of August, ongoing drought conditions (D3-Extreme) covered all of Prairie County. On the third week, the eastern half of Prairie County worsened to (D4-Exceptional) while the western half remained in (D3-Extreme) conditions. At the end of the month (D4-Exceptional) expanded further west to cover the eastern two thirds of Prairie County, with the western third remaining in (D3-Extreme) conditions.

Drought, Western Roosevelt

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Western Roosevelt forecast zone
Reported by: Drought Monitor
Coordinates: 48.295, -105.016 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions (D3-Extreme) continued for all but the northwestern corner of western Roosevelt County where this area had (D2-Severe) conditions. By the third week of August, all of western Roosevelt County was in (D3-Extreme) conditions. By the end of August (D4-Exceptional) conditions had expanded into the southwestern area, where the rest of western Roosevelt county remained in (D3-Extreme) conditions.

Drought, McCone

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: McCone forecast zone
Reported by: Drought Monitor
Coordinates: 47.645, -105.795 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions for McCone County worsened (D3-Extreme) for the majority of the county, the exception being the far northwestern corner where (D4-Exceptional) conditions were occurring. By the end of the month, all but the southeastern corner of McCone County was in (D4-Exceptional) with the southeastern corner remaining in (D3-Extreme) conditions.

Drought, Northern Valley

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Northern Valley forecast zone
Reported by: Drought Monitor
Coordinates: 48.365, -106.667 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions (D3-Extreme) occurred across most of Northern Valley County, the exception being (D2-Severe) in the far southeast corner of Northern Valley County. By the third week of August, all of Northern Valley County was in (D3-Extreme) conditions. By the end of the month, the eastern half of Northern Valley County had worsened to (D4-Exceptional) while the western half remained in (D3-Extreme) conditions.

Drought, Central and Southern Valley

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Central and Southern Valley forecast zone
Reported by: Drought Monitor
Coordinates: 48.365, -106.667 (the zone’s center; the record gives no point)

To start the month of August, ongoing drought conditions (D4-Exceptional) were found in the western two thirds of Central and Southern Valley County. Most of the eastern third was in (D3-Extreme) conditions, with the exception of the far northeast corner which was in (D2-Severe) conditions. By the third week all of the eastern third of Central and Southern Valley County worsened to (D3-Extreme) conditions, while the western two thirds remained in (D4-Exceptional) drought. At the end of the month, all but a little area of the north central portion of Central and Southern Valley County had worsened to (D4-Exceptional) conditions while that little portion remained in (D3-Extreme) drought.

Drought, Garfield

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Garfield forecast zone
Reported by: Drought Monitor
Coordinates: 47.278, -106.993 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions were in (D4-Exceptional) conditions across the northwestern third of Garfield County with the southeastern two thirds of Garfield County in (D3-Extreme) drought. At the end of August an area around the Dry Creek Arm of Fort Peck Lake worsened to (D4-Exceptional) conditions while the southeastern two thirds of Garfield County remained in (D3-Extreme) drought.

Drought, Northern Phillips

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Northern Phillips forecast zone
Reported by: Drought Monitor
Coordinates: 48.259, -107.913 (the zone’s center; the record gives no point)

To start the month of August, ongoing drought conditions started at (D3-Extreme) for all but the extreme northwest corner of Northern Phillips county which remained in (D2-Severe). These conditions remained the same through the end of August.

Drought, Central and Se Phillips

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Central and Se Phillips forecast zone
Reported by: Drought Monitor
Coordinates: 48.259, -107.913 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions were (D4-Exceptional) in the eastern and southeastern three quarters of Central and Southeast Phillips County, with the western and north western quarter in (D3-Extreme) conditions. These conditions remained the same through the end of August.

Drought, Petroleum

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Petroleum forecast zone
Reported by: Drought Monitor
Coordinates: 47.118, -108.250 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions were (D4-Exceptional) for the northern three quarters of Petroleum County, while the southern quarter of Petroleum County remained in (D3-Extreme) conditions. These conditions remained the same through the end of August.

Drought, Little Rocky Mountains

When: August 1, 12:00 AM MST to August 31, 11:59 PM MST
Where: Little Rocky Mountains forecast zone
Reported by: Drought Monitor
Coordinates: 48.259, -107.913 (the zone’s center; the record gives no point)

To start August, ongoing drought conditions were in (D3-Extreme) conditions for all of the Little Rocky Mountains. These conditions remained the same through the end of August.

What these are

Drought: A drought reaching severe (D2) or worse on the US Drought Monitor, or with notable impacts.

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

The same day elsewhere

Every storm in Montana in 2021 Every state in 2021 This day in weather history Warnings in Montana, August 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: 975600, 975608, 975668, 975670, 975671, 975991, 975997, 976063, 976500, 977999, 978000, 978001, 978002, 978003, 978004, 978005.