Montana, 2018

Drought in Montana, August 7 to 31, 2018

August 7 to 31, 2018 · NWS GGW · 2 events in 2 counties and zones

The prevailing weather pattern favored a high pressure ridge over the region for many weeks. A persistent lack of rainfall for northern Phillips and northern Valley Counties led to small areas of Severe Drought Conditions (D-2) which lasted throughout the month of August.

Where it happened

Every event with a place to put it; 2 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

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The toll

Deaths
0
Injuries
0
Property damage
None recorded
Crop damage
None recorded
Events
2

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.

The prevailing weather pattern favored a high pressure ridge over the region for many weeks. A persistent lack of rainfall for northern Phillips and northern Valley Counties led to small areas of Severe Drought Conditions (D-2) which lasted throughout the month of August.

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 Aug 6, 9:00 PM MST, 3 hours earlier.

Area forecast discussion, Aug 6, 9:00 PM MST, 3 hours before
Area Forecast Discussion
National Weather Service Glasgow MT
1000 PM MDT Mon Aug 6 2018

.DISCUSSION...
Evening Update: Only minor changes to the forecast were needed for
this evenings forecast, as observations are indicating that it is
drier than previous forecast. Overnight relative humidities have
been lowered to reflect the drier atmosphere. Poor RH Recoveries
are expected over portions of Southern Valley and southern
Phillips, and portions of northern Petroleum counties overnight.

Otherwise, high pressure aloft is forecast to continue to build in
over Montana and the northern Rockies, with dry conditions and
very hot daytime temperatures forecast Thursday through Saturday.
High temperatures are forecast to reach into the triple digits
during this time period.  tec

Previous Discussion: The last remnants of unsettled weather are
showing up in a few scattered rain showers and isolated
thunderstorms through Roosevelt and Richland Counties this
afternoon. As high pressure and a more stable atmosphere continues
to push into the region from the west, this convective activity
over the eastern 1/3 of our CWA will diminish through this
evening.

Tuesday through Friday, a large and strong ridge of high pressure
will build over most of the western states and spill over above
the high plains regions. This will likely bring very hot and very
dry conditions to all of NE Montana. Near record high temperatures
are forecast for the latter part of the week...see additional
information in the climate discussion below. Fire weather concerns
may rise, but for most of this time period, forecast wind speeds
are only around 10 mph at the most. Maybe leading up to the end of
the heat wave, model wind speeds increase a bit on Saturday and
Sunday. Will need to keep an eye on this for our fire weather
partners.

Being as far out in the forecast as it is, the end of the heat
wave sometime this coming weekend holds some uncertainty with
timing and winds, but generally we expected cooler temperatures to
arrive by Saturday night or Sunday as the next storm system moves
up and over the northern Rockies.

BMickelson
&&

.AVIATION...

FLIGHT CAT: VFR through the period.

DISCUSSION: A strong ridge of high pressure will dominate the
region's weather for most of this week, keeping skies fair with a
few afternoon CU.

WINDS: From L&V TO WSW OVERNIGHT from 5-10 kts, then WNW around 10
kts late morning and afternoon Tuesday becoming L&V during the
evening.
tec

&&

.CLIMATE...

Location / Record Highs For Thu (8/9) / Fri (8/10) / Sat (8/11)

Glasgow    / 101 (1940) / 103 (1935) / 104 (1897)
Wolf Point /  99 (1998) / 105 (2000) / 104 (1984)
Jordan     / 106 (1940) / 106 (1935) / 106 (1940)
Glendive   / 105 (1940) / 104 (1936) / 106 (1928)
Sidney     /  98 (2007) /  98 (2007) /  97 (2006)

&&

.GLASGOW WATCHES/WARNINGS/ADVISORIES...NONE.

&&

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

2 drought. Local standard time, as filed.

Drought, Northern Phillips

When
August 7, 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)

Rainfall amounts from the previous few months were around one half to one inch below normal across the northern edge and northeastern corner of northern Phillips County. After the first week of August, as the vegetation dried out, drought conditions (D2 - Severe) began there by August 7th. The latter part of the month provided some relief with one to two inches of precipitation, which was just below normal for August across the most heavily impacted areas. As recovery was still far away, drought conditions persisted into September.

Drought, Northern Valley

When
August 7, 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)

Rainfall amounts from the previous few months were around one to two inches below normal across the northwestern corner of northern Valley County. After the first week of August, as the vegetation dried out, drought conditions (D2 - Severe) began there by August 7th. The latter part of the month provided some relief with one to two inches of precipitation, which was approximately near normal for August across the most heavily impacted areas. As recovery was still far away, drought conditions persisted into September.

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

More

Every storm in Montana in 2018Every state in 2018This day in weather historyWarnings in Montana, 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: 774192, 774194.