Wildfire and Damaging Winds in Montana, September 3 to 21, 2022

Area Forecast Discussion
National Weather Service Great Falls MT
833 PM MDT Sat Sep 3 2022

.SYNOPSIS...

Near record temperatures and very dry conditions will continue
across North-central and Southwest Montana throughout Labor Day
Weekend. Southerly winds will become gusty by this evening as a
fast moving Pacific weather system approaches the northern
Rockies. This system will bring a westerly wind shift and a chance
for isolated showers and storms tonight. Breezy conditions and
only slightly cooler temperatures are then expected for the
remainder of the holiday weekend.

&&

.UPDATE...
No significant changes made to the current forecast. Remains on
track for dry conditions to continue along with gusty winds across
the region.

&&

.AVIATION...
820 PM MDT Sat Sep 3 2022 (03/00Z TAF period)

Areas of haze and smoke across northern terminals this evening,
otherwise mainly clear skies persist through the TAF period. High
level cloud bases associated with a low pressure system continues to
move in this evening that could bring isolated dry thunderstorms for
north central terminals. Ahead of the cold front, gusty winds have
been observed between 15 to 30 knots across terminals. Expect gusty
winds to continue through the TAF period then diminishing through
the overnight period. Webb

&&

.FIRE WEATHER...

Critical fire weather conditions are expected through at least
Sunday with today's extreme heat and dryness followed by
increasing and shifting winds this evening as a mainly dry cold
front moves through the area. South winds increase early this
evening and shift the west and northwest as the front moves
through the area late this evening. In addition, high based
showers and a few isolated dry thunderstorms are possible this
evening, mainly north of a line from Helena to Lewistown with
highest risk for an isolated thunderstorm occurring over areas
along and west of I-15 to the Rocky Mtn Front. Gusty winds will
re-develop Sunday afternoon in the wake of the departing weather
system in combination with still very warm temperatures and low
humidity. There is some potential for additional fire weather
highlights through Monday with one more day of breezy to windy
conditions expected before winds relax Monday night. Hoenisch

&&

.PREV DISCUSSION...
/ISSUED 820 PM MDT Sat Sep 3 2022/

An elongated upper level ridge of high pressure extends from the
southern Rocky Mtn States north across MT into the Canadian
Prairies this afternoon while an embedded compact upper level low
is moving NE toward the Northern Rockies around the periphery of
the ridge this afternoon. With temperatures already well into 90s
early this afternoon and little or no clouds through the rest of
this afternoon, temperatures are on pace to break daily records at
several locations with a few monthly records for September heat
also likely to go down.

The low and it's associated surface cold front to the west of the
area will move into the Northern Rockies this evening with models
just slightly slower now with the arrival of the cold front later
this evening and the progression of the low east along the
US/Canadian border overnight. Mid-level clouds and moisture
increase this evening as the low approaches with the main impact
being an increase in winds, initially from the south ahead of the
front this evening, then shifting to the west and northwest
behind the front. Moisture is generally limited to the mid-levels
from 500-300MB, but instability and dynamics with the incoming
low will likely produce some high based convective showers with a
more limited chance of an isolated embedded thunderstorm or two,
primarily associated with the frontal passage across central and
north-central MT later this evening and overnight. Very dry low-
levels will support the risk for some stronger wind gusts this
evening when the elevated showers develop in addition to the
already gustier winds anticipated in the vicinity of the cold
front. Fire weather highlights are in place for the critical
combination of wind/low RH and heat followed by gusty and shifting
winds this evening. Those with recreation plans this evening,
especially on area lakes should be aware and ready for any impact
from these winds as well.

The upper low continues east into ND Sunday with the upper ridge
moving to a position over the Great Basin and a still fairly fast
westerly flow to its north across MT. Temperatures cool slightly
but another day of max temperatures near daily records in the 90s
is expected. Breezy to windy conditions are expected to develop
by mid-day Sunday and continue into the early evening for another
round of critical fire weather conditions. Hoenisch

Monday through next Saturday...The warm and dry pattern continues
through at least mid-week, though another passing shortwave may
bring increased westerly winds once again on Monday followed by a
slight cool down on Tuesday. The wind and low relative humidity
combination may require additional fire weather products, but
decided against issuing a watch with this forecast package.

Ensembles continue to hint on another system to passing through the
northern Rockies during the latter half of the work week into the
weekend. A wide range of potential outcomes and run to run
inconsistencies among the members themselves erodes forecast
confidence. However, at this time it appears that there will be an
increase in winds, precipitation probability, and temperatures look
to cool closer to climatology. - RCG

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  59  93  54  93 /  20   0   0   0
CTB  58  87  53  84 /  40   0   0   0
HLN  60  94  57  95 /  20   0   0   0
BZN  53  93  50  95 /   0   0   0   0
WYS  43  86  39  86 /   0   0   0   0
DLN  52  91  49  91 /   0   0   0   0
HVR  65  94  59  93 /  20  10   0   0
LWT  58  91  54  93 /   0   0   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
Red Flag Warning in effect from 12PM MDT Saturday through 6PM MDT
Sunday for Fire Weather Zones 108, 110, 111, 112, 113, 114, 115,
116, 117, and 118; which includes portions or all of Glacier, Toole,
Liberty, Hill, Blaine, Pondera, Teton, Chouteau, Cascade, Judith
Basin, Fergus, Lewis and Clark, Meagher, Jefferson, Broadwater,
Beaverhead, Madison, and Gallatin Counties.

Air Quality Alert in effect through 8AM MDT Monday for Beaverhead
County.

&&

http://www.weather.gov/greatfalls

Special Weather Statement
National Weather Service Great Falls MT
925 PM MDT Sat Sep 3 2022

MTZ009-010-046-048-040415-
Southern Rocky Mountain Front MT-Northern Rocky Mountain Front MT-
Eastern Glacier MT-Eastern Pondera MT-
925 PM MDT Sat Sep 3 2022

...A strong thunderstorm will impact portions of northwestern
Pondera, Glacier and northwestern Teton Counties through
1015 PM MDT...

At 925 PM MDT, Doppler radar was tracking a strong thunderstorm near
Browning, moving northeast at 55 mph.

HAZARD...Wind gusts of 50 to 55 mph.

SOURCE...Radar indicated.

IMPACT...Gusty winds could knock down tree limbs and blow around
         unsecured objects.

Locations impacted include...
Cut Bank, Browning, Valier, East Glacier Park Village, South
Browning, North Browning, East Glacier Park, Kiowa, Heart Butte,
Dupuyer, Saint Mary and Starr School.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

If outdoors, consider seeking shelter inside a building.

&&

LAT...LON 4900 11260 4829 11208 4808 11297 4813 11301
      4812 11305 4815 11306 4814 11312 4817 11320
      4824 11323 4836 11336 4842 11335 4842 11341
      4850 11348 4855 11347 4859 11355 4869 11364
TIME...MOT...LOC 0324Z 239DEG 49KT 4848 11310

MAX HAIL SIZE...0.00 IN
MAX WIND GUST...55 MPH

Brusda

PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
929 PM MDT SAT SEP 3 2022

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0918 PM     TSTM WND GST     1 ENE EAST GLACIER PARK 48.45N 113.20W
09/03/2022  M53 MPH          GLACIER            MT   MESONET

            MESONET STATION MTBRN TWO MEDICINE BRIDGE
            (MT DOT).

&&

BRUSDA