Area Forecast Discussion
Issued by NWS Great Falls, MT

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FXUS65 KTFX 082023
AFDTFX

Area Forecast Discussion
National Weather Service Great Falls MT
223 PM MDT Sat Aug 8 2020

.SYNOPSIS...

A weak cold front moving south across North Central and Central
Montana this evening and tonight will bring about breezy and
gusty northwest to northerly winds, and even an isolated sprinkle
to the mountains. Highs on Sunday will be well below normal across
the region, with readings only expected to be the 70s.
Temperatures will rebound quickly for the first half of the work
week, with highs returning closer to normal values by Tuesday.

&&

.DISCUSSION...

Rest of this afternoon through Tuesday...primary forecast concerns
throughout the period will be fire weather, especially on Tuesday as
a combination of breezy and dry conditions make a return to the
Northern High Plains.

Another breezy day is occurring across portions of Central and North
Central Montana (generally northwest of a Lincoln, to Great Falls,
to Havre line) today, with sustained southwest to west winds of 15
to 25 mph and gusts approaching 40 mph. In addition to the breezy
winds, dry conditions are also being observed with minimum relative
humidity values having fallen into the 15% to 25% range. While some
areas are currently seeing a combination of low relative humidity
and breezy conditions, these conditions are not expected to persist
for more than a couple of hours consecutively. None-the-less,
Elevated to near-Critical Fire Weather conditions will remain
present across the region into the evening hours, with even a few
isolated locations possibly seeing Critical Fire Weather Conditions
for more than three hours. Given the isolated nature of these
Critical Fire Weather conditons, will hold-off with any fire weather
highlights, but extra caution is urged with any activity that could
cause a spark and lead to a fire.

A weak cold front will advance south from Canada and across North
Central Montana during the late evening/overnight hours tonight,
before stalling along the Central Montana mountains by Sunday
morning. Impressive pressure rises behind this front will likely
lead to a brief period of breezy and gusty winds, in addition to a
wind shift to the northwest/north. Some short-term models are
showing the possibility for a few rain showers along the front as it
advances south, mainly over the mountains, but given the dry low
levels and a shallow moisture column aloft I don`t expect anything
more than a few sprinkles for these mountainous areas. Northwest
flow aloft over the region on Sunday will help to maintain continued
below normal temperatures across Southwest through North Central
Montana (especially across Central and North Central Montana where
low level cold air advection will be seen in wake of the cold
front), with highs only rising into the 70s. Temperatures will begin
to moderate during the first half of the work week as the flow aloft
becomes more zonal to southwesterly, with highs returning closer to
normal by Tuesday. This return to zonal/southwesterly flow will
bring about low afternoon relative humidity values, with readings
falling into the teens to low 20s at most locations. Increasing
cross barrier flow/mid-level winds on Tuesday combined with these
dry conditions will bring about increasing Fire Weather concerns,
especially over the plains of Central and North Central Montana. -
Moldan

Wednesday through next Saturday...Things begin to change on
Wednesday as an upper level trough begins to move towards the area,
which will bring back the chances for afternoon and evening showers
and thunderstorms on Wednesday. While this particular system will be
fast-moving, another trough will follow on its heels, which will
bring another chance for some afternoon showers and thunderstorms to
the region Thursday. Ensemble data from the GEFS, experimental GEFS,
and EPS all suggest that the area remains under the influence of
some sort of a trough through the first part of the weekend, but
each system has its own idea as to what that looks like for us. As a
result, each day beyond Wednesday will feature near to slightly
below average temperatures with 20-30 POPs in the afternoons and
evenings for convective showers and thunderstorms. - Ludwig

&&

.AVIATION...
1136 AM MDT Sat Aug 8 2020 (08/18Z TAF Period)

VFR conditions prevail throughout this TAF period. Gusty winds along
with a post-frontal wind shift present the greatest aviation
impacts. Expect the associated turbulence.
- Fogleman

Refer to weather.gov/zlc for more detailed regional aviation weather
and hazard information.

NOTE: Amendments not scheduled for Ennis (KEKS) due to ongoing
runway closure.

&&

.PRELIMINARY POINT TEMPS/POPS...
GTF  48  75  47  83 /   0   0   0   0
CTB  44  72  43  82 /   0   0   0   0
HLN  51  79  48  85 /   0   0   0   0
BZN  44  79  44  85 /   0   0   0   0
WYS  36  74  36  80 /   0   0  10  10
DLN  44  78  44  82 /   0   0   0   0
HVR  50  75  45  85 /  10   0   0   0
LWT  48  71  44  81 /   0   0   0   0

&&

.TFX WATCHES/WARNINGS/ADVISORIES...
None.
&&

$$

http://www.weather.gov/greatfalls


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