NWS Great Falls, MT wrote its last area forecast discussion before the first event at Aug 31, 10:54 PM MST, 1 hour 6 minutes earlier.
Area forecast discussion, Aug 31, 10:54 PM MST, 1 hour 6 minutes before
Area Forecast Discussion...CORRECTED
National Weather Service Great Falls MT
1154 PM MDT Wed Aug 31 2022
UPDATED AVIATION SECTION
.SYNOPSIS...
Hot and dry conditions will continue through the weekend, with
Saturday being the hottest day of the upcoming stretch. An
isolated shower or thunderstorm can't be ruled out overnight.
However, little, if any rainfall is expected to reach the surface
under any such showers.
&&
.UPDATE...
Main update is to issue a Fire Weather Watch for Fire Weather
Zones 113, 115, and 117 from late Thursday morning through
Thursday evening. Hot, dry, and breezy conditions will prevail for
much of the daytime period, but there will also be a wind shift
from northwesterly to northeasterly with a cold front moving south
across the plains late Thursday afternoon through Thursday
evening.
&&
.AVIATION...
1154 PM MDT Wed Aug 31 2022 (01/06Z TAF period)
VFR conditions with mostly clear skies will generally continue
across North Central, Central, and Southwest Montana through at
least the next 24 hours. However, a disturbance moving into the area
from the west currently could bring a few high-based showers with
erratic wind gusts to the terminals on the east slopes of the
Rockies (KCTB KGTF) and over far southwest Montana (including KWYS)
through around 11Z. These gusty winds could also cause brief periods
of reduced visibility to MVFR levels in blowing dust. A few embedded
thunderstorms are possible, but the likelihood that they will
directly impact those terminals is low. Confidence is also low that
these showers/storms will hold together long enough to impact the
eastern TFX plains terminals (KHVR KLWT). In the wake of the
disturbance, west to northwest winds will become breezy and gusty
after 16Z, especially over the plains, where gusts could exceed 25
kt at times.
-Coulston
&&
.FIRE WEATHER...
Highly elevated to critical fire weather conditions are expected
Thursday with hot, dry, and windy conditions. A cold frontal
passage will result in a wind shift later in the day Thursday from
north to south, and this will be an extenuating factor in issuing
a Fire Weather Watch. Another chance for critical to extreme fire
weather conditions comes Saturday as a strong and fast moving
upper disturbance moves over the region bringing record-breaking
heat, dry and windy conditions, along with a strong and sudden
wind shift associated with a potentially strong cold frontal
passage.
Note that due to technical issues on our end, we are currently
unable to transmit the Fire Weather Watch product. However, the
product is mentioned in the Fire Weather Planning Forecast
(GTFFWFTFX).
&&
.PREV DISCUSSION...
/ISSUED 213 PM MDT Wed Aug 31 2022/
Broad upper-level ridging continues to be the dominant feature
across the western CONUS throughout the next several days,
furthering the hot and dry conditions experienced in Southwest and
North-central Montana. A weak disturbance and associated cold
front will pass overtop the ridge tonight into tomorrow morning,
bringing periods of breezy to gusty winds and the chance for
showers. Precipitation, if any, will be minimal and will likely be
restricted to higher elevations along the Northern Rocky Mountain
Front. However, it cannot be ruled out for the possibility of
isolated dry thunderstorms, as suggested by SPC. Forecast
soundings within Northwest Montana depict a deep, dry boundary
layer with precipitable water values of just around half an inch,
nearing favorable conditions for dry thunderstorms. In addition,
concerns for erratic gusty winds, especially in the vicinity of
collapsing showers, are possible.
The passage of the aforementioned disturbance and cold front
leading to increased wind gusts in conjunction with the low
relative humidity values approaching single digits has put a minor
concern for fire weather across eastern portions of North-central
and Southwest Montana Thursday afternoon. Fortunately, the threat
is lessened by the fact that many of the larger fuels around the
area were affected by the recent rainfall from the previous week.
Nevertheless, sparks, naturally or man-made, can most definitely
cause new fire starts and should be monitored accordingly.
Thereafter, the upper-level ridge is expected to rebuild over the
western CONUS, reestablishing hot and dry conditions Friday into
Saturday, with Saturday being the warmest day of the week. Many
locations are forecast to approach or hit triple digits with the
surplus of warm, dry southwesterly winds. However, another
shortwave, notably stronger than the previous, propagates into the
ridge late Saturday afternoon, leading to another period of
breezy to gusty winds in excess of 35 mph. Ensemble cluster
analysis is in general agreement through Day 6 depicting the
upper-level ridge will begin to flatten; however, it will also
remain strong over western CONUS, continuing the hot and dry trend
heading into next week. - Pierce
&&
.PRELIMINARY POINT TEMPS/POPS...
GTF 57 94 54 95 / 30 20 0 0
CTB 58 89 52 90 / 30 10 0 0
HLN 60 94 58 95 / 10 10 0 0
BZN 54 93 51 93 / 10 10 0 0
WYS 42 84 38 85 / 20 0 0 0
DLN 52 90 48 91 / 20 0 0 0
HVR 61 96 57 93 / 0 20 0 0
LWT 56 92 54 90 / 0 10 0 0
&&
.TFX WATCHES/WARNINGS/ADVISORIES...
Fire Weather Watch in effect from 10 AM Thursday to Midnight MDT
Thursday Night...Central and Eastern Lewis and Clark National
Forest Areas...Chouteau and Fergus Counties...Hill and Blaine
Counties
&&
http://www.weather.gov/greatfalls